Report of the Committee on Smoke Management Systems

Harold E. Nelson, C/uz& Hughes Associates Inc., MD [SE]

Daniel L. Arnold, RolfJensen & Assoc., GA [SE] Donald W. Belles, Donald W Belles & Assoc. Inc., TN [M]

Rep. American Architectural Mfrs. Assn. Jack B. Buckley, Houston, TX [SE] Elmer F. Chapman, NewYork City Fire Dept., NY [E] Michael Earl Dillon, Dillon Consulting Engr, Inc., CA [SE] S. E. Egesdal, Honeywell Inc., MN [M]

Rep. Nat'l Electrical Mfrs. Agsn. CharlesJ. Green, Colt Int'l. Ltd., England [M] GunnarHeskestad, Factory Mutuzd Research Corp., MA [I] William R. Houser, U.S. Army Environmental Hygiene Agency, MD [u] Winfield T. Irwin, Irwin Services, PA [M]

Rel~. North American Insulation Mfrs. Agsn. DameIJ. Kaiser, Underwriters Laboratories Inc., IL [RT] John E. Kampmeyer, Maida Engr, Inc., PA [SE] John H. KIote, U.S. Nat'l. Inst. of Standards and Technology, MD [RT] Gary D. Loagheed, Nat'l. Research Council of Canada, Canada [RT] FrancisJ. MeCabe, Prefco Products, PA [M] James A. Milke, University of Maryland, MD [SE] Gregory IL Miller, Code Consultants Inc., MO [SE] Erin A. M. Oneisom, l_kS. Air Force, Civil Engr Support Agency, FL [U] Lyman L. Parks, Bellcore, NJ [U] Zenon A. Pihut, Texas Dept. of Health, TX [E] Dale Rammlen, Air Movement & Control Assn., Inc., IL [M] John F. Scarff, Marriott Corp., DC [U] William A. Schmidt, Bowie, MD [SE] Todd E. Schumann, Industrial Risk Insurers, IL [I] J. Brooks Semple, Smoke/Fire Risk Mgmt. Inc., VA [SE]

Alternates

Eric Anderson, System Sensor, IL [M] (Alt. to S. E. Egesdal)

Craig Beyler, Hughes Assoc. Inc., MD [SE] (AIt. to H. E. Nelson)

RichardJ. Davis, Factory Mutual Research Corp., MA[I] (Alt. to G. Heskeshad)

Victor L. Dubrowskl, Code Consultants Inc., MO [SE] (Ait. to G. R. Miller)

Geraldine Massey, Dillon Consulting Engr, Inc., CA [SE] (AlL to M. E. Dillon)

Jayendra S. Parikh, Underwriters Laboratories Inc., IL [RT] (Air. to D.J. Kaiser)

Randolph W. Tucker, RoffJensen & Assoc., "IX [SE] (Alt. to D. L. Arnold)

Paul G. Turnbull, Landis & Gyr Powers, Inc., IL [M] (Voting Alt. to L&G. P. Rep.)

Peter J. Gore W'dlse, Industrial Risk Insurers, CT [I] (Air. to T. E. Schumann)

Michael L. Wolf, Greenheck, WI [M] (Alt. to D. Rammien)

Nonvoting

Bent A. Borresen, Techno Consultant, Norway (Alt. to C. N. Madsen)

E. G. Butcher, Fire Check Consultants, England (Alt. to A. G. Parnell)

Christian Norgaard Madsen, Techno Consultant, Norway Alan G. Parndl, Fire Check Consultants, England

Rou Cot6, Staff Liaison

This list represents the membership at the time the Committee was balloted on the text of this edition. Since that time, changes in the membership may have occurred. A key to classifications is found at the front of the book.

Committee Scope: This Committee shall have primary responsibility for documents on the design, installation, testing, operation, and maintenance of systems for the control, removal, or venting of heat or smoke from fires in buildings.

The Report of the Technical Committee on Smoke Management Systems is presented for adoption.

This Report was prepared by the Technical Committee on Smoke Management Systems and proposes for adoption a complete revision to NFPA 204M-1991, Guide for Smoke and Heat Venting. NFPA 204M-1991 is published in Volume 10 of the 1996 National Fire Codes and in separate pamphlet form.

This document when adopted will be renumbered as NFPA 204, Guide for Smoke and Heat Venting.

This Report has been submitted to letter ballot of the Technical Committee on Smoke Management Systems. which consists of 27 voting members. The results of the balloting, after circulation of any negative votes, can be found in the report.

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N F P A 2 0 4 M - - A 9 7 R O P

(Log# l ) 204M- 1 - (.1-14 (New)): Reject SUBMITTER: Douglas E. Leihlxacher, Yonkers Fire Department, NY RECOMMENDATION: Add new text ,as follows:

~In buildings containing trnss roof construction, sufficient heat- activated smoke vents shall be installed in tile roof so that heat and smoke from a fire will be automatically removed from tile building by mechanical means." SUBSTANTIATION: Manyfirefighters have lost their lives when they've a t tempted to ventilate truss roof's that collapsed without warning beneath them. Automatic vents would m,'xke it unnecessary for firefighters to set foot on truss roofs during fire conditions. Vertical ventilation would be per formed automatically. COMMIaTI'EE ACTION: Reject. COMMrVrEE STATEMENT: To do as tile submitter requested and require the installation of vents is outside the scope of this guide. Tins guide is in tended to provide guidance on how to design an effective venting system, but is not in tended to serve as a code and mandate vents. Such requirements need to be addressed by a code (i.e., a fire prevention code or a model building code). NUMBER OF COMMITTEE MEMBERS ELIGIBLE TO VOTE: 27 VOTE ON COMMITTEE ACTION:

AFFIRMATIVE: 25 ABSTENTION: 1 NOT RETURNED: 3 Green, Mc(;abe, Scarff

EXPLANATION OF ABSTENTION: KAlVIPMEYER: I am abstaining primarily because I ,am concerned

about the use of Sl units throughout the document . The document presents good information for the designer, but its usefulness is limited by not being presented in units familiar to building design and construction personnel. ! do not feel this is sufficient to vote negatively, but should be considered in the future development of tile document .

(Log #CP1 ) 204M- 2 - (Entire Document): Accept SUBMITTER: Technical Committee on Smoke Management Systems,

[ RECOMMENDATION: Replace NFPA 204M-1991, Guide for | Smoke and Heat Venting, with tile following complete rewrite.

SUBSTANTIATION: The 1991 edition of this guide included tables listing vent areas on the basis of preselected design objectives. The tables were based on the hot upper layer at 20 percent of the ceiling height. Different layer depths were accommodated by a "multiplica- tion factor." Curtain board and vent spacing rules were set. Minimum clear visibility times were related to fire growth rate, ceiling height, compar tment size, curtain depth and detector activatio n times using engi n eeri ng equations and a set o f assu rap- lions that sometimes led to conservative solutions.

This proposed complete rewrite deletes the previous tables listing vent areas. It incorporates engineer ing equations or references models. The equations or models provide the designer with the nece~ary tools to develop vent desigris based on selected perfor- mance objectives related to a specific building and specific set of circumstances. Engineering equations are included for calculating vent flows, layer depths, and upper layer temperatures based on a prescribed burning rate.

For tile first time, this guide will include a computer model (LAVENT) as well as engineering equations (i.e., hand calculation methods) .

This rewrite is based extensively on state-of-the-art technology published in the references cited in brackets th roughout tile draft document and listed in Section 13-6, Section C-9, and Section E-2. In many cases the authors of these references participated in tile task group rewrite efforts. COMMITFEE ACTION: Accept. NUMBER OF COMMITTEE MEMBERS ELIGIBLE TO VOTE: 27 VOTE ON COMMITTEE ACTION:

AFFIRMATIVE: 22 NEGATIVE: l ABSTENTION: l NOT RETURNED: 3 Green, McCabe, Scarff

EXPLANATION OF NEGATIVE: PIHUT: Use of a dimensional system that is not used currently by

the design professionals in this country is my reason for the negative vote on die entire NFPA 204M document. EXPLANATION OF ABSTENTION:

KAMPMEYER: I am abstaining primarily because I am concerned about the use of SI units throughout tile document . Tile documen t presents good information for tile designer, but its usefiflness is limited by not being presented in units familiar to building design and construction personnel. I do not feel this is sufficient to vote negatively, but should be considered in the filture development of the document .

584

NFPA 204

Guide for

Smoke and Heat Venting

1997 Edition

NOTICE: An asterisk (*) following the number or letter designating aparagraph indicates explanatory material on that paragraph m Appendix A.

Information on referenced publicatious can be found in Chapter 10 and Appendix E. Detailed information on refer- ences cited in brackets throughout the document can be found in Section B-6, Section c-g, and Section E-2.

Chapter 1 General Information

1-1 Introduction.

1-1.1 Previous editions of this l~guide have included tables listing vent areas based on preselected design objectives. These tables were based on the hot upper layer at 20 percent o f the ceiling height. Different layer depil-as were accommodated by using a multiplication factor. Curtain board and vent spacing rules were set. Minimum clear visibility times were related to fire growth rate, ceiling height, compar tment size, curtain depth, and detector activation ames using engineet ing equations and a set of assumptions that sometimes resulted in conservative solutions.

This edition has eliminated tile previous tables listing vent areas. This edition incorporates engineering equations (hand calculations) or references models. The e(tuadons or models provide the designer with tile necessary tools to develop vent designs based on sele~'ted performance objectives related to a specific building and specific set of circumstances. Engineering equations are included for calculating vent flows, layer depths, and upper layer tempera- tures based on a prescribed burning rate.

An example using both hand calculations and tile LAVENT (Link- Activated VENTs) computer model is presented as an appendix. (See Appendix D.)

The majority of the information provided in this guide applies to nonspt inklered buildings. A limited amount of guidance is provided in Chapter 8 for sprinklered buildings.

1-1.2 The following is a general description of the significant phenomena that occur d-uting a fire when a fire-ventJng strategy is tmplemented:

(a) Due to buoyancy, hot gases rise vertically f rom the combustion zone and then flow horizontally below the roof until blocked by a vertical barrier (a wall or curtain board), thus initiating a layer of hot gases below tile roof.

(b) The volume and temperature of gases to be vented are a function of the rate of heat release of the fire and the amount of air entrained into tile buoyant plume produced.

(c) As tile depth of the layer of hot gases increases, the layer temperature continues to rise and the vents open.

(d) The operation of vents widfin a curtained area enables some of the upper la-yer of hot gases to escape and slow the thickening rate of the layer of ho t gases. With sufficient venting area, the thickening rate of the layer can be arrested and even reversed. The rate of discharge through a vent of a given area is primarily de te rmined by tile depth of tile layer of hot gases and tile layer temperature. Adequate _quantities of replacement inlet air from air inlets located below the hot upper layer are needed if the products of combustion- laden upper gases are to be exhausted according to design. [See Figures I-7.2(a) and I-1.2(b).]

Curtain boards ~ t ' ~ Fire barrier

\ Fi+e L 's r~ l~ i~ . LL~j?

F'tgure 1-1.2(a) Behavior of combustionproducts under vented and curtained roof .

N F P A 2 0 4 M ~ A 9 7 R O P

Figure l- l .9(b) Buildlng wifl~ roof vents.

1-1.3" The equations and procedures for h a n d calculations in Section 6-I provide two different types of guidance, The first addresses the ve at ing of Ihnited-growth fires. These are fires that are no t expected to grow beyond a predictable hea t release rate. The s econd type of gu idance is re le~mt to the vent ing o f fires that, if uncbecked, will c o m i n u e to grow to an unpredictable size. T he engineer ing equat ions or models incorporated in flais guide ,allow an estimate of bow well smoke can be conf ined to a cur ta ined area and how long the smoke interface can be main ta ined at a h igher level than the de.sign elevation of the cur ta ined area. This m i n i m u m clear- visibility design t ime facilitates such activities as locating the fire, apprais ing the fire severity and its extent, evacuating the building, and making an in fo rmed decision on the dep loyment of personnel and e q u i p m e n t to be used for fire fighting.

1-2 Application and Scope.

1-2.1" The provisions of Chapters 2 t h rough 7 o f this guide are in t ended to offer guidance for the design of facilities for emergency vent ing of products of combus t ion f rom fires in nonsprinldered, single-story buildings. Both mamml and compu te r mode led solution methods are provided in Chapter 6 to aid in design calculation. A limited amou tat of informat ion regarding vent ing in s prinklered buildings is included in Chapter ~q. These provisions oo not a t t empt to specify unde r what condit ions vent ing is to be provided; such conditions are d e p e n d e n t upon an armlysis of the individual situation and Ioc~al building code and fire code requirements .

1-2.2 This gtlide does not apply to o ther ventilation des igned for regulation of t empera tu re within a building, for personnel comfort or cooling of product ion equ ipment , or to vent ing provided for explosion pressu re rel ie~: See NFPA 68, (~*idefor Venting of Defk~gvations.

1-2.3 This guide applies to building construct ion of all types.

1-2.4 The concepts set forth in this guide were developed for vent ing fires in large undivided floor areas with ceiling laeights sufficient to allow the design fire p lume and smoke layer to develop (normally 4,6 m or greater). The application of d~ese concepts to buildings o f smaller area or lower ceiling heights necessitates careful engineer ing j udgmen t .

1-3 Determinat ion o f Occupancy Hazard.

I-3.1 Tests and studies provide a basis for the division of occupan- cies into c l a s se sdepend ing upon the fnel available for contr ibut ion to fire. Tlaere is awide variation in tile quantit ies o f combust ible materials in the many kinds of buildings and areas of buildings. The evaluation should take into account the average or anticipated fuel loading and the rate of heat release anticipated from the combus- tible materials or f lammable liquids conta ined therein.

1-3.2 Cbapter 5 should be referenced to assist in quantifying types of fires in various occupancies. Cb,xracterisdc heat release rates for boti~ limited-growda and cont immus-growth fires in various types of fnel arrays also are addreg~ed.

1-3.3 It shou ld be recognized that m a n y large facilities have buildings or areas subject to different fire hazards. Accordingly, vent ing facilities should be des igned specifically for each space as discussed in dais guide.

1-4 Nomencla ture . The following symbols def ine the variables in the equat ions used t h r o u g h o u t the main text o f this guide. (See Appendix B for an explanat~'on of the unique nomenclature used in that appendix.)

A

A .

nv = Ava =

O~g = C

d = d c D = g = H = h =

C =

m

I = L = M. =

~ s t m

m t = m." o m.v = T/z =

=

Q " = Qc = r

RTI =

p

t =

td =

AT

AT e

T T? TIg =

S U

V = X =

r z =

z O =

area (of bu rn ing surface) area for fresh air, below design level of smoke interface actual total ven t a rea aerodynamic vent area thermal diffusivity, k / p c fire growth coefficient specific hea t smoke layer dep th depd'l of curtain board base d iameter of the fire acceleration of gravity ceiling he igh t above base of fire heat of combusdon hea t of gasification thermal conductivity constant used in equat ion 5-3 thermal inert ia thickness mean f lame he igh t multiplier (vent size) mass burn ing rate mass burn ing rate per un i t area mass bu rn ing rate for an infinite d iameter pool mass flow rate t h rough vent mass flow rate in the p lume m p at m e a n flame he igh t (L) I

incident hea t f lux per uni t area total hea t release rate

total hea t release rate per uni t plan area convective hea t release rate (approx. 0.7 Q.) radius f rom fire axis response t ime index ('~u 1/2, where 1: is the time cons tant o f the heat-responsive e l ement for convective heat ing) density t ime design interval t ime .growth .time. tame to i gmuon time to detection gas t empera tu re rise (from ambient) at detector site t empera ture rise (from ambient) of heat- responsive e l ement am.b!ent air t empera ture l gmnon tempera ture surface t empera tu re gas velocity at detector site f lame spread velocity radiant fraction he igh t above base of fire he igh t of 'Mrtual origin" above base o f fire (below base of fire, if negative).

Chapter 2 Basic Phenomena

2-1 Prlnciples of Ventlng.

2-1.1 Venting Objectives. Venting of a building is provided to slow or stop tl~e descen t of a smoke layer for purposes such as:

(a) Providing occupants with die oppor tuni ty to travel to a safe a r e a ,

(b) Facilitating manual fire f ight ing by vent ing smoke and hot gases, enabl ing fire fighters to reach the origin or seat o f the fire.

(c) Reducing damage to buildings a n d contents due to smoke an d ho t gases.

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N F P A 2 0 4 M - - A 9 7 R O P

2-1.2 Vent Designs and Smoke Generation. Tile heat release rate of a fire, the fuel geometry, the height of the clear layer above tile base of the fire, and the design depth of the smoke layer are major factors affecting theproduc t ion of smoke. Given such knowledge about a f r e , venting designs can be developed in accordance with this guide in which tile vent area is calculated to achieve a mass rate of flow through vents that matches the mass rate of production of smoke. Such a design prevents descent o f the smoke layer below the design height of the clear layer. Alternate designs are possible wilere tile vent flow is less than file rate of smoke production in which the descent of the smoke layer is slowed sufficiently to meet design objectives.

2-1.3 Vent Mass Flow. Vent design criteria in this g~uide assume the mass flow rate through a vent is de termined primarily by buoyancy pressure. Mass flow through a vent, therefore, is governed mainly by tile free vent area and depth of the hot layer, and-its temperature.

(a) Ven t ingbecomes more effective with smoke temperature differentialsbetween ambient temperature and an upper layer of approximately 110°C or higher. Where temperature differentials of less than 110°(3 are expected, vent flows mi~{ht be reduced signifi- candy, therefore, confideration should be gaven to using powered exhaust. NFPA 92B, Guide for Smoke Management S3stems in Malls, Atria, and Large Areas. should be consul ted for guidance for power venting at these lower temperatures.

(b) The vent design criteria in this guide also allow the fire to reach a size where tile flame plume enters tlae upper hot layer. Flame height may be estimated using equation 6-L

2-2 Smoke Production.

2-2.1 Entrainment at the Plume Boundary. The rate of production of smoke is dependen t on the rate of ent ra inment of air into a column of hot gases produced by and located above a fire. Entrain- ment is affected by tile fire diameter and rate of imat release, and is strongly ,affected by the distance between the base of the fire and the point at which the smoke plume enters the hot upper layer.

2-2.2 Base o f the Fire. The location of the base of the fire is that level at wllich significant en t ra inment begins to occur. For file purposes of the equations in this guide, this is at the bot tom of the nurning zone.

2-2.3 Fire Size. Since smokeproduc t ion is related to the size of a fire, it logically follows that, aflfactors being equal, larger fires produce more smoke. However, en t ra inment ~s strongly affected by ihe distance between the base of a fire and the bottom of the ho t layer. Therefore, the base of rile fire (where combustion and entra inment begin) should be selected carefiflly. It is possible for a smaller fire having a base near the floor to produce more smoke than a larger fire with a base at a higher elevation. Each possible fire scenario should be considered carefully before establishing the conditions of the design fire.

2-2.4 Entrainment and Clear Height. Entra imnent is assumed to be limited to the clear height between the base of the fire and the bottom of the hot layer. Tile buoyant plume ,associated with a fire produces a flow into tile hot upper layer. As the plume impinges on the ceiling, the plume turns a n d f o r m s a ceiling jet . The ceiling j e t flows radiMly outward along the ceiling.

2-2.5 Smoke Production as a Function of Shape of l~re. Tile ent ra inment formulas specified in this guide predict smoke production ,assuming a single fire. Where the possibility of multiple fires, and, therefore,-multiple p lumes exist, smoke product ion rates increase beyond the rate predlcted for a single p lume for a fire of equivalent output. It also should be unders tood that smoke ent ra inment relationships are developed primarily for file case of axisymmetric plumes. For line-like fires where a long, narrow plume is created by a fuel or storage array, the smoke production relation- ships in this guide might not be valid. However, if the height of the smoke layer interface above the base of the fire (H-d) is large compared to the largest horizonhal dimension of the fire (e.g., greater than approximately tllree times), the empirically derived relationships in this guide can be used to predict smoke production.

2-2.6 Virtual Origin. Plume m,x~ flow above tile flame level is based on the concept that, except for absolute scales, die shapes of velocity and temperature profiles at the mean flame height are invariable [Heskestad 1983]. This concept leads to an expression for mass flow above the flames that involves the so-called 'Mrmal origin," a point source from which the plume above tile flames appears to originate. The virtual origin might be above or below the base of the fire.

2-3 Vent Flows.

2-3.1 Buoyancy and Vent Flow. Flow through a vent in th isguide is calculated on tile basis o f buoyancy pressure. It is ,assumed that

openings exist to the outside and, therefore, no pressure results from the expansion of gases. Wind effects are not taken into account, as wind might assist or interfere with vent flows, depending upon specific circumstances° It is also assumed that the fire environment in a building space is divided into two zones - - a hot upper layer and a relatively cool, clear (comparatively free of smoke) lower region. Where a fire grows to a size where it approaches ventilation-limited burning, the building might no longer maintain a clear lower region, and this guide would no longer be applicable. Finally, caution needs to be exercised where using dais guide for conditions where the upper gas layer temperature approaches 600°C, as flashover might occur within the compartment . Wilere a fire develops to flashover or ventilation-limited burning, the relationships provided in this guide are not applicable.

2-3.2 Buoyancy Pressure. Buoyancy pressure is related to the depth of the ho t layer, the absolute temperature of the hot layer, the temperature rise above ambient of the hot layer, and the density of the ambient air.

2-3.3 Vent Mass Flow. The mass rate of flow of hot gases through a vent is a function of vent area, layer depth, and hot layer tempera- ture.

2-3.4 Temperature and Vent Flow. The temperature of the hot layer above ambient affects mass flow through a vent. Maximum flow occurs at temperature differentials of approxi'mately 300°C above ambient. Flows at other temperature differentials are diminished as shown in Figure 2-3.4o

: )

I [ LL o

f, k- L~ <

o ...I I.L

<

1

.6

.4

.2

0 0 200 400 ;00 800

TEMPERATURE ABOVE A M B I E N T K

1000

Figure 2-3.4 Effect o f temperature on mass flow through a vent.

2-3.5 Inlet Air.

2-3.5.1 To function as intended, a building venting system needs sufficiently large fresh air openings at low levels. The effect o f inlet air on vent flow is addressed in 6-1.3.1. For example, where high upper layer temperatures of 400 K above ambient are anticipated, 80 percent of the predicted vent flows is expected to be achieved with an inlet a rea /vent area ratio of 1, whereas it is expected that 90 percent of the vent flow will result f rom a ratio of 2. Where relatively low upper layer temperatures, such as 200 K above ambient, are expected, a ratio of inlet a i r /vent area of 1 would result in about 70 percent of the desired vent flows, whereas a ratio of 2 would be expected to produce about 90 percent of the vent flow.

2-3.5.2 If doors and windows below the design smoke layer do not meet file total r ecommended inlet air opening area, special air inlet provisions are necessary.

2-3,5.3 It is essential that a dependable means for admitting or supplying inlet air be providedprompt ly after the first vent opens.

2-3.5.4 Makeup Air System. The simplest me thod of introducing makeup air into the space is through direct openings to the outside, such as doors and louvers, which can be opened upon system activation. Such openings can be coordinated with the architectural design and be located as necessary below the design smoke layer.

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N F P A 2 0 4 M i A 9 7 R O P

For locations where such openings are no t practicable, a powered supply system might be considered. This might be an adaptation of the building's HVAC system, provided capacities, outlet grille Io~t ions, and velocities are suitable. For such systems, means should be provided to prevent supply systems from operating until exhanst flow has been establ ishedto avoid pressurization of the fire a r e a .

Chapter 3 Vents

3-1 Types of Vents.

3-1.1 Experience has shown that any opening in a roof, over a fire, relieves some heat and smoke. However, building designers and fire protection engineers cannot rely on casual inclusion of skylights, windows, or monitors as adequate venting me,ms. Standards exist (UL 793- Automat i~l ly Operated Roof Vents for Smoke and Heat, FM 4430 - Approval Standard for Heat and Smoke Vents, UBC Standard 15-7-Automatic Smoke and Heat Vents) that include design criteria and test procedures for unit vents that call for simulated fire tests as well as engineering analysis.

3-1.2 Guidelines for the inspection and maintenance of vents are contained in Chapter 9.

3-2 Vent Design Constraints.

3-2.1 Materials of construction and methods of installation need to be used appropriately to resist expected extremes of temperature, wind, building movement, rain, ball, snow, ice, sunlight, corrosive environment, internal and external dust, dirt, and debris. Compat- ibility between the vent-mounting elements and the building strncture to which they are attacbed needs to be ensured (e.g., holding power, electrochemical interaction, wind lift, building movement) .

3-2.2 Vents designed for multiple functions (e.g., the entrance of day-lighting, roof access, comfort ventilation) need maintenance of the fire protection time!ion that might be impaired by the other uses. Tbese impairments can include loss of spring tension, racking or wear of moving parts, adverse exterior cooling effects on the fire protection release mecbanism, adverse changes in performance sequence such as premature heat actuation leading to opening of the vent, or reduced sensitivity to heat.

3-2.3 To avoid inadvertent operation, it is important that the actuating e lement be selected witla regard to the fidl range of expected ambient conditions.

3-2.4 Vents might be a single unit (entire unit opens fidly with a single sensor) or multiple units in rows, clusters, groups, or other arrays that satisfy the venting recommendat ions for the specific hazard.

3-2.5 If the hazard is localized (e.g., dip tank, solvent storage), it is r ecommended that the vents be located directly above such hazard.

3-2.6 It is essential that the specific vent mecharfism and structure be ,arranged to be inspected easily.

3-3 Methods of Operation.

3-3.1 An automatic mechanism for opening the roof vents is r ecommended for effective release of heat, smoke, and gaseous by- products. If excessive smoke is likely to be generated prior to the release of sufficient heat to open vents, smoke detectors with appropriate linkages to open vents should be used.

3-3.2 If failure of a vent operating componen t occurs, it should lead to an open vent condition. Gravity should be used as the opening force, wid~ ensurance that tile opening mechanism cannot be blocked easily by snow or roof debris or internal projections. Alternate opening mechanisms should be reliable.

3-3.3 All mechanic~aily opened vents also should be designed to open by manual means.

~3.4 To be effective, latching mecbanisms should bejamproof , corrosion-resistant, and resishant to pressure differentials arising from windstorms, process operations, overhead doors, or traffic vibrations.

3-4 Dimensions and Spacing of Vents. The dimensions and spacing of vents ~ua be considered effective where the following criteria are m et:

~ a~2Either 6 (1) The area o f a un i tven t or cluster does not exceed O_ or 2d ~ where d c is the depth of the curtain board and d is the

design depth of the smoke layer. These depths are measured from the centerline of the vent. ( See Figures 4-3(a) through (d).), or (2) The width of the monitor does not exceed the depth of the curtain board, d o or the design depth of the smoke layer, d, where curtains are not provided.

(b) The vent spacing is such that, in plan view, the distance between any point in the plane of the roof and the nearest vent, all within the curtained area, does not exceed 2.8H (the diagonal of a s~uare whose side is 2H), where H is the ceiling height. (Also see Figures 4-3(a) through (d).)

(c) The total vent area per cur tained compar tment under the ceiling depends on the severity of the expected fire, which is discussed m Chapter 5.

3-5 Mechanical Vents. Where mechanical vents are considered, see Chapter 7.

Chapter 4 Curtain Boards

4-1 General. In large, open areas, curtain boards enhance p rompt activation of the vents and venting effectiveness by containing the smoke in the curtained area.

4-2 Construction. Curtain boards should be made of substantial, noncombustible materials and constructed to resist the passage of smoke.

4-3 Location and Depth. To ensure smoke containment, curtain boards, where provided, should extend down from the ceiling for a StLqlcient distance to ensure that the value o f d o as shown in Figures 4-3(a) through (d), is a minimum of 20 percent of ceiling height, H, where H represents the ceiling height:

(a) For fiat roofs, measured from the ceiling to the floor.

(b) For sloped roofs, measured from the center of the vent to the floor. Where there are differing vent heights, H, each vent should be calculated individually.

t H

~ / / / / / / / / / / / / / / / / / / / ~ (a) Flat roof

Figure 4-3(a) Measurement of ceiling height (H) and curtain depth (dc) for fiat roof.

~ / / / / / / / / / / / / / / / / / / / ~ (b) Gabled roof

Figure 4-3(b) Measurement of ceiling height (H) and curtain depth (d c) for gabled roof.

587

N F P A 2 0 4 M ~ A 9 7 R O P

l j.j jjjjjj.j,j,j t (c) Sloped roof

"//////~.

Figure 4-3(c) Measuremen t o f ceiling height (H) and curtain depth (dc) for s loped roof.

H

~ / / / / / / / / / / / / / / / / / / / / ~ (d) Sawtooth roof

Figure 4-3(d) Measuremen t o f ceiling height (H) ~/nd curtain depth (dc) for sawtooth roof.

NOTE: If d c exceeds 20 percent of H, H - d c should be no t less than 3 m. For Figure 4-3(d), this concept valid where A d / d c is m u c h less than 1.

4-4 Spacing.

4-4.1 The distance between curtain hoards (or between walls without intervening curtain boards)should no t exceed 8 t imes the ceiling he igh t to ensure that vents remote from tile fire within the cur ta ined compartmer~t are effective.

4-4.2 Smaller cur ta ined areas shou ld be used where occupancies are particularly vnlnerable to damage. The distance between these curtain boards shou ld be not less than twice tile ceiling height. This spacing guidance carl be disregarded for curtain boards that extend down to a depth of at le:mt 40 percent of the ceiling height.

Chapter 5 Predicting the Rate o f Heat Release of Fires

5-1 Introduction. This chapter presents techniques for est imating the heat release rate of warious fuel arrays likely to be present in buildings where smoke and heat vent in~ is a potential fire safety provision. It primarily addresses the esumat ion of fiJel concentra- tions found in storage and mamffac tur ing IoGttions. NFPA 92B, Guide for Smoke Managevngnt Svst~n.~ in MalL~, Atria, and Large Areas, addresses the types o f fuel arrays more c o m m o n to the types of building si tuations covered by tha t stancL'trd. NFPA 204 is applicable to si tuations where tile hot layer does not enhance the bu rn ing rate. Tile m e t h o d s p r o v i d e d in dtis chapter for est imating the rate of hea t release, therefore, are bo.sed on "free burning" condit ions where no ceiling or hot gas layer effects are inwdved. It is, therefore, a s sumed that the burn ing rate is relatively unaffected by the hot layer.

5-2 Sources of Data. The following sources of data appear in their approximate order of priority, given equal quality of data acquisi- tion.

(a) Actual tes~ of tile array involved;

(b) Actual tests of similar arrays;

(c) Algur i thms derived from tests of arrays having similar fuels and dimensional characteristics;

(d) Calculations based on tested propert ies and materials an d expected f lame flux;

(e) Mathematical models of fire spread and development .

5-3 Actual Tests o f the Array Involved. Where an actual calorific test of file specific array unde r considerat ion has been conducted and the data is in a fo rm that can be expressed as rate of heat release, file data can then be used as inpu t for the me thods in this guide. Since actual test data se ldom produces the steady state a s sumed for a limited-growth fire or the square of t ime growth assumed for a continuous-growth fire, eng ineer ing j u d g m e n t is usually needed to derive the actual input necessary if ei ther of these approaches are used. f f t he compute r model LAVENT or o ther model that is able to respond to a rate of heat release versus t ime curve is used, the dam can be used directly. Currently there is no established catalog of tests of specific arrays. Some tes t data can be found in technical reports. Alternatively, individual tests can be conducted.

Many fire tests do no t include a direct m e a s u r e m e n t of rate of heat release. In some cases, it can be derived based on m e a s u r e m e n t of mass loss rate us ing the following equation:

Q= rn hc (5-1)

(Q in kW, m in kg/s , h c in kJ/kg)

In o ther cases it can be derived based on m e a s u r e m e n t of f lame height as follows:

Q = 37(L + 1.02 D) 5 / 2 (5-2)

( Q i n kW, L in m, D in m)

5-4 Actual Tests o f Arrays Similar to that Involved. Where an actual calorific test of the specific array unde r considerat ion cannot be found, it migh t be possible to f ind data on one or more tests that are similar to tlae fuel of concern in impor tan t matters such as type of fuel, a r rangement , or ignit ion scenario The more the actual tests are similar to the fuel o f concern, the h igher the confidence that can be placed in the derived rate of hea t release. Added eng ineer ing j u d g m e n t , however, migh t be needed to adjust the test data to that approximat ing the fuel of concern. If rate of heat release has not been directly measured , it can be est imated us ing the me thods provided in Section 5-3.

5-5 Algori thms Derived from Tests o f Arrays Having Similar Fuels and Dimensional Characteristics.

5-5.1 Pool Fires. In many cases, the rate of heat release of a tested ,array has been divided by a c o m m o n dimension, such as occupied floor area, to derive a normal ized rate of heat release per uni t area. The rate of heat release of pool fires is the best d o c u m e n t e d and accepted a lgor i thm in dais class.

An equat ion for the mass release rate f rom a pool fire is as follows [ Babrauskas 1995 ]:

fi t" = rh~o l1 - e-'(kel3)D ] (5-3)

The variables rh~o a n d k , ~ for equat ion 5-3 are as shown in Table 5-5.1 [Babrauskas 1995]. [ Babrauskas 1995 ].

588

NFPA 204M i A97 R O P

Table 5-5.1 Data for Large Pool Burning Rate Estimates

Material Oe.sit~ hc flU" ~ (kg/m o) (MJ/kg) ~ (m' l ) ~l~/m2s)

Cryogenics* Liquid H 2 LNG (mostly CH 4) LPG (mostly C 3H8)

Alcohols methanol (CH 3OH) ethanol (C2H5OH)

Simple organic filels butan~e (C 4 H 10) benzene (C 5H6) hexane (C 6 H 14) heptane (C 7 H 16) xylene (CsHI0) acetone (C 3H6 O) dioxane (C 4H802) diethyl e ther (C 4 H 10 O)

Petroleum products benzine SerOline

osine

transformer oil, hydrocarbon tirol oil, heavy crude oil

Solids polymethyimedlacrylate (C 5H802) n polypropyiene (C 3H6) n ' polystyrene (C 8H8) 0

70 120.0 0.017 6.1 415 50.0 0.078 1. I 585 46.0 0.099 1.4

796 20.0 0.017 ~ ' t 794 26.8 0.015 ,,or

573 45.7 0.078 2.7 874 40.1 0.085 2.7 650 44.7 0.074 1.9 675 44.6 0.101 1.1 870 40.8 0.090 1.4 791 25.8 0.041 1.9

1035 26.2 0.018** 5.4** 714 34.2 0.085 0.7

740 44.7 0.048 3.6 740 43.7 0.055 2.1 820 43.2 0.039 3.5 760 43.5 0.051 3.6 810 43.0 0.054 1.6 760 46.4 0.039** 0.7**

940-1000 39.7 0.035 1.7 830-880 42.5--42.7 0.022-0.045 2.8

1184 24.9 0.020 3. $ 905 43.2 O.O18

1050 39.7 0.034

*For I~ools on dry land, not over water. **Esumate uncertain since only two data points available. tValue independen t o f diameter in turbulent regime.

The mass rates derived from equation 5-3 are converted to rates of heat release using equation 5-1, and tbe beat Of combustion from tile Table 5-5,1. The rate of heat release per uni t area times tile area of the pool yields heat release data for the anticipated fire.

5-5.2 Other Normalized Data. Odler data based on burning rate per unit area in tests have been developed. Tables 5-5.2(a) and (b) list these data.

5-5.3 Other U.~eful Data. There are other data that are not normalized that might be usefifl in developing die rate of heat release curve. Examples are included in tim Tables 5-5,3(a) through (d):

5-6 Calculated Fire D~scrlption Based on T ~ t e d Properties.

5-6.1 Background. It is possible to make general estimates of die rate of beat release of burning materials based on the fire properties of that material. The fire properties involved are de termined by small-scale tests. The most important of these tests are due calorim- eter tests involving bofll oxygen depletion calorimetry and file

application of external heat flux to the sample while determining time to ignition, rate of mass release, and rate of heat release for the specific applied flux. Most p rominent of the current test apparatus are the cone calorimeter (ASTM E 1354, Standard Test Method for Heat and Visible Smoke Release Rates for Materials and Products Using an Oxygen Consumption Ca/or/meter) and the Factory Mutual calorimeter [Tewarson 1995]. In addition to these directly measured properties, it is possible to derive ignition temperature, critical ignition flux, effective thermal inertia (kpc), heat of combustion, and heat of

based on results from these calorimeters. Properties not ruble from these calorimeters and essential to de termining flame.

spread in directions not concurrent with the flow of the flame can be obtained f rom the LIFT (Lateral Ignition and Flame Travel) apparatus (ASTM E 1321, Standard Test Method for Determining Material Ignition and F/ame Spread Propert/es). This section presents a concept of the use of fire property test data as the basis of an analytical evaluation of the rate of heat release involved in the use of a tested material. The approach outlined in this section is based on that presented by Nelson and Forssell [ 1994].

589

N F P A 2 0 4 M - - A97 R O P

Table 5-5.2(a) U n i t H e a t R e l e a s e Rates f o r F u e l s B u r n i n g in t h e Open

Commodity

Flammable liquid pool Flammable liquid spray Pallet stack

Wood or PMMA*(vertical) - 0.61-m height - 1.83-m height - 2.44-m height - 3.66-m height

Wood or PMMA - Top of horizontal surface

Solid polystyrene (vertical) - 0.61-m height - 1.83-m height - 2.44-m height - 3.66-m height

Solid polystyrene (horizontal)

Solid polypropylene (vertical) - 0.61-m height - 1.83-m height - 2.44-m height - 3.66-m height

Solid polypropylene (horizontal)

H e a t R e l e a s e R a t e ( k W )

3300/m ~ of surface 560/lpm of flow 3500/m of height

100/m of width 240/m of width 620/m of width 1000/m of width

720/m a of surface

220/m of width 450/m of width 1400/m of width 2400/m of width

14001m a of surface

220/m of width 350/m of width 970/m of width 1600/m of width

800/m a of surface

*PMMA, Polymethyi Methacrylate (Plexiglass. Lucite. Acrylic)

T a b l e 5 - 5 . 2 ( b ) U n i t H e a t R e l e a s e Ram f o r C o m m o d i t i e s

Heat release rate per unit floor area of fully involved combus- tibles, based on negligible radiative feedback from the surround- ings and I00 percent combustion efficiency.

Commodity

Wood pallets, stacked 0.46 m high (6-12% moisture) 1,420

Wood pallets, stacked 1.52 m high (6-12% mois- ture) 4,000

Wood pallets, stocked 3.05 m high (6-12% moisture) 6,800

Wood pallets, stacked 4.88 m high (6-12% moisture) 10,200

Marl bags, filled, stored 1.52 m high 400 Cartons, con~partmented, stacked 4.5 m high 1,700 PE letter trays, filled, stacked 1.5 m high on cart 8,300 PE trash barrels in cartons, stacked 4.5 m high 2,000 PE fiberglass shower stalls in canons, stacked

4.6 m high 1,400 PE bottles packed in Item 6 6,200 PE bottles in cartons, stacked 4.5 m high 2,000 PU insulation board, rigid foam, stacked 4.6 m

high 1,900 PS jars packed in Item 6 14,200 PS tubs nested in cartons, stacked 4.2 m high 5,400 PS toy parts in cartons, stacked 4.5 m high 2,000 PS insulation board, rigid foam, stacked 4.2 m

high 3,300 PVC hordes packed in Item 6 3,400 PP tubs packed in Item 6 4,400 PP & PE film in rolls, stacked 4.1 m high 6,200 Methyl alcohol 740 Gasoline 3~oo Kerosene 3,300 Diesel oil 2,000

k W p e r m 2 o f

F l o o r A r e a

PE = Polyethylene PS = Polystyrene PV = Polyvinyi chloride

PP = Polypropylene PU = Polyurethane

590

NFPA 204M m A97 ROP

Table S-&S(8) Chamcteri~'cs d Ignition Sources

Typical mum mum Hemt Burn Flame FLmne Heat

Ouqmt Tune" Helzht Width Flux ( ~ (s) (ram) (nun) OkWlm t)

Cigarette 1.1 g (not puffed, laid on solid surface), bone dry, 5 1200 - - 42 conditioned to 50% R.H. 5 1200 - - 35

Methenamine pill, 0.15 g 45 90 - - 4

Match, wooden (laid on solid surface) 80 20-30 30 14 18-90

Wood cribs, BS 5852 Part2 No. 4 crib, 8.5 g 1000 190 15 d No. 5 crib, 17 g 1900 900 17 d No. 6 crib, 60 g 2600 190 20 d No. 7 cry , 126 g 6400 350 25 ~

Crumpled brown lunch bag, 6 g 1900 80

Crumpled wax paper, 4.5 g (tight) 1800 25

Crumpled wax paper, 4.5 g (loose) 5300 20

Folded double-sheet newspaper, 22 g (bottom ignition) 4000 100

Crumpled double- sheet newspaper, 22 g (top ignition) 7400 40

Crumpled double- newspaper,

22 g (bottom igni- tion) 17,000 20

Polyethylene waste- basket, 285 g, filled with 12 milk car- tons (390 g) 50,000 200 b 550 200 35"

Plastic u-ash bags, 120,000 filled with cellulosic to trash (1.2-14 kg) e 350,000 200 b

• Time duration of significant flaming b Total bum time in excess of 1800 sec c AJ measured on simulation burner • Measured from 25 mm away • ReSults vary greatly with packing density

Table 5-5.$(©) Maximum ~ gelem~ Itat~ from Fine Det~_,x.~_'on Institute Amdyds

Approvlmmt~. Valuw 0~w)

Medium wastebasket with milk cartons 100 Large barrel with milk cartons 140 Upholstered chair with polyurethane foam 350 !~t~z foam mattress (heat at room door) 1200 Furnished living room (heat at open door) 4000-8000

Table 5-SJCo) ~_,,s~teristlcs of Typical Furnlshm" p u lpdtlon Sources

Malimum Thermal

Total MssJmum Radiation Total Heat Rate of Heat to C~nter Mass Contest Relmuse of Floor" 0 ~ ~ J ) 0~w) 0~W/mb

Waste paper baskets 0.73-1.04 0.7-7.3 4-18 0.1 Curtain& velvet, cotton 1.9 24 160-240 1.3-3.4 Curtains, acrylic/cotton 1.4 15-16 130-150 0.9-1.2 TV sets 27-33 145-150 120-290 0.3-2.6 Chair mockup 1.36 91-22 63-66 0.4-0.5 Sofa mockup 9.8 49 1.q0 0.9 Arm chair 26 18 160 1.2 Christmas trees, dry 6.5-7.4 11-41 500-650 3.4-14

• Measured at approximately 2 m away from the burning object

591

N F P A 2 0 4 M I A 9 7 R O P

Table 5-5.$(d) M a ~ Load u d Heat Re lease l t a t ~ o f

C12 17.9 F22 31.9 F23 31.2 F27 29 .0 F28 29.2 CO2 13.1 CO3 13.6 CO1 12.6 CO4 12.2 C16 19.1 F25 27.8 T 6 6 23 .0 F21 28,3 F24 28.3 C13 19.1 C14 21.8 C15 21.8 T49 15.7 F26 19.2 F33 39.2 F31 40 .0 F32 51.5 T57 54.6 T56 11.2 CO9gr64 16.6 CO7/T48 11.4 C10 12.1 C l l 14.3 F29 14.0 F30 25.2 C 0 8 16.3 CO5 7.3 CO6 20.4 T50 16.5 "1"53 15.5 T54 27.3 T75/F20 7.5(x4)

H a m Comlmatible o0 s~t, 17.0 traditional easy chair

traditional easy chair traditional easy chair traditional easy chair traditional easy chair

12.2 traditional easy chair 12.7 traditional easy chair 11.7 traditional easy chair 11.3 traditional easy chair 18.2 traditional easy chair

traditional easy chair traditional easy chair traditional easy chair traditional easy chair

18.2 traditional easy chair 20.9 traditional easy chair 20.9 traditional easy chair

easy chair th inner easy chair traditional Ioveseat traditional loveseat traditional sofa Ioveseat office chair

16.2 foam block chair 11.2 m o d e r n easy chair

8.6 pedestal chair 14.3 foam block chair

traditional easy chair traditional easy chair

15.4 pedestal swivel chair 7.3 bean bag chair

20.4 frameless foam back chair waiting r o o m chair

1.9 waiting room chair 5.8 metal f rame loveseat 2.6 stacking chairs (4)

P e a k m P e a k q Frmne P add l n~ Fabric ln~rllner (~/sec) (kW)

wood cotton nylon - ]9.0 290" wood cotton (FR) cotton - 25.0 370 wood cotton (FR) olefin - 42.0 700 wood mixed cotton - 58.0 920 wood mixed cotton - 42.0 730 wood cotton, PU olefin - 13.2 800 b wood cotton, PU cotton - 17.5 460* wood cotton, PU cotton - 17.5 260" wood PU nylon - 75.7 1350 b wood PU nylon n e o p r e n e NA 180 wood PU olefin - 80.0 1990 wood PU, polyester cotton - 27.7 640 wood PU (FR) olefin - 83.0 1970 wood PU (FR) cotton - 46.0 700 wood PU nylon neop rene 15.0 230* wood PU olefin neop rene 13.7 220* wood PU olefin neop rene 13.1 210 b wood PU cotton - 14.3 210 wood PU (FR) olefin - 61.0 810 wood mixed cotton - 75.0 940 wood PU (FR) olefin - 130.0 2890 wood PU (FR) olefin - 145.0 3120 wood PU, cotton PVC - 61.9 1100 wood latex PVC - 3.1 80 wood (part) PU, polyester PU - 19.9 460 PS foam PU PU - 38.0 960 rigid PU foam PU PU - 15.2 240* - PU nylon - NA 810 b PP foam PU olefin - 72.0 1950 rigid PU foam PU olefin - 41.0 1060 molded PE PU PVC - 112.0 830 b - po lDtyrene PVC - 22.2 370* - PU acrylic - 151.0 2480 b metal cotton PVC - NA < 10 metal PU PVC - 13.1 270 metal PU PVC - 19.9 370 metal PU PVC - 7.2 160

• Estimated f rom mass loss records and assumed Wl~ b Est imated f rom doorway gas concentrat ions

5-6.2 Discussion o f Measured Properties. Table 5-6.2 lists the type of fire properties obtainable from the cone or Factory Mutual calorimeters and similar instruments.

Table 5-6.2 Relation of Calorimeter-measured Properties to Fh'e Analysis

Property

Rate of heat release t Mass loss t Time to ignitiont Effective thermal properties* Heat of combustion* Heat of gasification* Critical ignition flux* Ignition temp.*

Ignition

XXX

XXX

X~X

XXX

F l a l n e

Spread

XXX

XXX

XXX

XXX

XXX

XXX

Fire Size

XXX

XXX

XXX XXX

t Property is a function of the externally applied incident flux. * Derived properties from calorimeter measurements.

In Table 5-6.2, the rate of heat release (RHR), mass loss, and time to ignition are functions of the externally applied incident radiant heat flux imposed on the tested sample. The purpose of the externally applied flux is to simulate the fire environment surround- ing a burning item. In general, it can be estimated that a free- burning fuel package (i.e., one that burns in the open and is not affected by energy feedback from a hot gas layer of a heat source other t~an its own f i n e ) is impacted by a flux in the range of 25 k W / m to 50 kW/m . f f the fire is in a space and conditions are 9 approaching2ilashover, this can increase to the range ofS0 kW/m" to 75 k~q/m . In fully developed, post-flashover fires, a range of 75 k W / m " to over 100 k W / m " can be expected. Thefol lowing is a discussion of the individual properties measured or derived and the usual form used to report the property.

(a) Rate o f Heat Release. Rate of heat release is de te rmined by oxygen deplet ion calorimetry. Each test is run at a user-specific incident flux and for either a prede termined per iod of time or until the sample is consumed. The complete results are presented in the form of a plot of rate of heat release against time, with the level of applied flux noted. In some cases, the rate of heat release for several tests of the same material at different levels of applied flux is plotted on a single curve for comparison. Figure 5.6.2(a) is an example of such a plotting.

592

N F P A 2 0 4 M - - A 9 7 R O P

2000

~ 1600 "

__ 1200 ! , e ' ~ .... 1000 j .F z- - , .

6oo ~ ; i \

~" 200

o ~'~ " ~ ~ ~ ' 0 200 400 600 800 1000 1200 1400

Time (s) 1600

Figure 5-6-2(a) Typical graphic output of cone calorimeter test.

Often only the peak rate of hea t release at a specific flux is reported. Table 5-6.2(a) is an example.

Table 5-6.2(a) Aver t I ,~ Maximum Heat Release Rat~s (kW/m2) 25 kW/m 2 50 kW/m 2 75 kW/m 2

Material Orientation

PMMA Horizontal Vertic=d

Pine Horizontal Vertical

Sample A Horizontal Vertical

S.'m~ple B Horizontal Vertical

Sample C Horizontal Vertical

Sample D Hotizonml Vertical

Exposing Flux

65O 56O 140 130 125 9O

140 6O

7O

Ex po~ ng Flux

9O0 720 240 170 200 130 175 200 215 165 145 125

:ExpofingFlux

1300 1300 265 240 250 22O 240 330 25O 170 145 125

(b) Mass Logs Rate. Mass loss rate is de t e rmined by a load cell. The m e t h o d of repor t ing is identical to that for rate of heat release. In the typical siutation where the material has a consistent hea t of combusuon , the curves for mass loss rate and rate of hea t release are similar in shape.

(c) T ime to Ignition. T ime to ignition is repor ted for each individual test ,and applied flux level conducted.

(d) Effective Thermal Inertia (kpc). Effective thermal inertia is a m e a s u r e m e n t of the hea t rise response of the tested material to the hea t flux imposed on the sample. It is derived at the t ime of ignition and is based on the ratio of the actual incident flux to the critical ignition flux and the time to ignition. A series of tests at different levels of applied flux is necessary to derive the effective thermal inertia. Effective thermal inertia derived in this manner can differ f rom and be preferable to that derived using handbook data for the values of k, p, and c derived without a fire.

(e) Heat o f Combust ion. Heat of combust ion is derived by dividing the measured rate of heat release by the measured mass loss rate. It is normally reported as a single value, unless the sample is a composite material and the rates of heat release and mass loss vary significantly with t ime and exposure.

(f) Heat o f Gasification. Heat of gasification is the flux needed to pyrolyze a uni t mass of fitel. It is derived as a hea t balance and is usually reported ,as a single value in terms of the a m o u n t of energy per uni t mass of material rele:Lsed (e.g., kJ/g) .

(g) Critical Ignition Flux. Critical ignition flux is the m i n i m u m level of inc ident flux on the sample n e e d e d to i~gnite the sample given an unl imited t ime of application. At incident flux levels less than the critical ignition flux, ignition does not take place.

(h) Ignition Tempera ture . Ignition t empera tu re is the surface tempera ture of a sample at which f lame occurs. This is a sample material value that is i n d e p e n d e n t of the incident flux. It is derivable f rom the calorimeter tests, the LIFT appara tns test, and other tests. It is derived from the t ime to ignite in a given test, the

applied flux in that test, and the effective thermal inert ia of the sample. It is repor ted at a single tempera ture . If the test includes a pilot f lame or spark, the repor ted tempera ture is for piloted kgnition; . . . . . . . . fit_here is no pilot present , the t empera tu re is for au to igmuon . Most avatlable da ta ts for pdoted tgmuon .

5-6.$ Ignition. Equat ions for t ime to ignition, tito are given for both thermally thin and thermally thick materials, as ~e t ined in 5-6.3(a) and (b). For materials o f in termedia te depth , estimates for ti~ necessitate considerat ions beyond the scope of this presenta t ion [Drysdale 1985, Carslaw and Jaeger 1959].

(a) Thermal ly Thi0J~/laterial~ Relative to ignit ion f rom a constant incident hea t flux, q: , a t the exposed surface and with relatively small hea t t ransfer Io~ses at the unexposed surface, a thermally thin material is a material whose t empera tu re is relatively un i fo rm t h r o u g h o u t its entire thickness, / , at t =tig. For example, at t = rig:

Texpose d - Tunexpose d = Tig - Tunexpose d < 0.1 (Tig - To) (5-4)

Equat ion 5-4 can be used to show that a material is thermally thin [Ca~slaw and Jaeger 1959] if:

I < 0.6(tig a ) 1 /2 (5-5)

For example, for sheets ~f ngaple or oak wood (where the termal diffusivity a = 1.28 x 10- m ~ / s [DiNenno et al 1995]), if tie = 35 s is measured in a piloted ignition test, then, according to eqd~tion 5-5, if the sample thickness is less than approximately 0.0013 m, the unexposed surface of the sample can be expected to be relatively close to T:_ at the t ime of ignition, and the sample is considered to be t h e r m ~ y thin.

The time to ignition of a thermally thin materiN subjected to incident flux above a critical incident flux is:

t. = 9clfTig-~ To) tg (5-6)

qi (b) Thermal ly Thick Materials. Relative to the . t~e of ignit ion test

described in 5-6.3(a), a sample of a material o f a thtckness, / , is considered to be thermally thick if the increase in t empera ture of the unexposed surface is relatively small compared to tha t of the exposed surface at t = t ig . For example, at t = tig:

Tunexpose d - T O < 0.1 (Texpose d - To) = 0.1 (Tig - To) (5-7)

Equat ion 5-7 can be used to show that a material is thermally thick [Carslaw a n d J a e g e r 1959] if:

t > 2(rig a ) 1/2 (5-8) For example, according to equat ion 5-8, in the case of an ignition

test on a shee t of maple or oak wood, if ti~ = 35 s is measured in a piloted ignition test, then, if the sample fffickness is greater than approximately 0.0042 m, the unexposed surface of the sample can be expected to be relatively close to T at t = t. and the sample is

• . O I considered to be thermally duck. g

Time to ignition of a thermally thick material subjected to incident flux above a critical incident flux is:

• I t 2

tig - (x /4 )k p c[ (Tig - T o ) / q i ] (5-9)

It should be noted that a particular material is no t intrinsically thermally thin or thick (i.e., the characteristic of being thermally thin or thick is no t a material characteristic or property) but also depends on the thickness of the particular sample (i.e., a particular material can be imp lemen ted in ei ther a thermally thick or thermally dtin configurat ion).

(c) Propagation Between Separate Fuel Packages. Where the concern is fo rp ropaga t ion between individual separated fuel packages, incident flux can be calculated us ing traditional radiation hea t transfer procedures [Tien et al 1995].

The rate of radiat ion hea t t ransfer f rom a f laming fuel package of total energy release rate, Q, to a facing surface e l ement of an exposed fuel package can be es t imated fi'om:

q ~t = X r Q / 4 ~ r 2 (5-10)

593

N F P A 204M ~ A97 R O P

5-6.4 Estimating Rate o f Heat Release. As discussed in 5-6.2, t ~ t s have demons t ra ted that the energy feedback fr-pm a burning~fuel package ranges f rom approximately ,'25 k W / m - - t o 50 kW/m% For a r e ~ o n a b l e conservative analysis, it is recotrug2ended tha t test data developed with an incident flux ofS0 k W / m be used. For a first order approximat ion, it should be as sumed that all of the surfaces that Can be simnltaneous]y inw)lved in I ) l l r n i J l g a r e releasing energy at a t=tte equal to that de t e rmined by testing the material~n a fire propertieg calorimeter with an i0cident flux of,90 k W / m for a free- bu rn ing material and 75 k W / m " to 100 k W / m " for post-fiashover conditions.

In making this estimate, it is necessary to `a~sume that all surfaces that c:m "see" an exposing flame (or superhea ted gas, in the post- flashover condit ion) are burn ing and releasing energy and mass at the tested rate. If sufficient air is present, dxe rate of hea t release estimate is t hen calculated ms the product of dye exposed m-ca and the rate of beat release per uni t area ,as de t e rmined in the test calorimeter. Where there is test data taken at the incident flux of dye exposing flame, die tested rate of hea t release shou ld be used. Where the test data is for a different incident flux, the burn in~ rate should be est imated us ing die beat of gasification as expres sed in equatio!a,,5-11 to calculate the mass burn ing rate per uni t area.

. , q,, m = - - (5-11)

hg The result ing mass loss rate is then mult ipl ied by the derived

effective heat of combus t ion and the bu rn ing area exposed to the incident flux to produce the es t imated rate of hea t release as follows:

qi'= ,/*"h cA (5-12)

5-6.5 Flame Spread. If it is desi red to predict the growth of fire ,as it fipropagates over colnbusdble surfaces, it is necessm'y to estimate

ame spread. The computa t ion off l ; ,me spread rates is an emerg ing technologysti l l in an embryonic stage. Predictions shotfld be considered `as order of magn i tude estimates.

Flame spread is the m o v e m e n t of the flame front across the surface of a material that is bu rn ing (or exposed to an ignition flame) where the exposed surface is not yet fidly inwdved. Pbysically, f lame spread can be treated `as a succession of ignitions result ing from the heat energy p roduced by the bu rn ing port ion of a material, its flmne, ,and any o ther incident heat energy imposed upon die u n b u r n e d surface. Other sources of incident energy include ano the r bu rn ing object, h igh tempera ture gases that can accumula te in the uppe r port ion of an enclosed space, and the radiant beat sources used in a test apparatus such as One cone calorimeter or the LIFT mecbanism. For analysis purposes, f lame spread can be divided into two categories, that which moves in the same direction as the f lame (concur ren t or wind<tided f lame spread) and that which moves in any o ther direction (lateral or opposed f lame spread) . C o n c u r r e n t f l a m e spread is assisted by the incident heat flux f rom the fi,'une to unigni ted port ions of the bu rn ing material. Later~d f lame spread is no t so ,assisted and tends to be m u c h slower in progression unless an external source of heat flux is present. Concur r en t f lame spread can be expressed ,as follows:

• t t

qi L V = (5d3)

kpc(Tig-Ts) 2

The values for krc and igrfition tempera ture are calculated from the cone calorimeter as discussed. For this equation, the f lame length (L) is measured from the leading edge o f the bu rn ing region.

5-6.6 Classification o f Fires for Engineering Equations. The engineer ing equat ions in Section 6-1 are appropria te for steady fires, l imited growth fires, and t-squared forms of cont inuous growth fires.

Chapter 6 Sizing Vents

6-1 Hand Calculations.

6-1.1 Elements o f Problem.

6-1.1.1 In Figure 6-1.1.1, H is the distance between the base o fd l~ fire and the ceiling; d c is the depth of die curtain boards, and d is the design depth of the smoke layer; rh~ is the mass flow rate of ho t gas f rom the fire p lume into the smoke'layer; rh v is the mass flow rate of hot ga.s out of fl~e vent (or vents) ; and A v is tile vent ,area (total vent area in cur ta ined compar tment , if more than one vent exists).

594

Av

I L°°t°n° il

Figure 6-1.1.1 Schematic o f vent ing system.

6-1.1.2 First equi l ibr ium condit ions are assumed, with the layer already having formed. The smoke interface is level with the bo t tom of the curtain boards. At equil ibrium, the mass flow rate into the smoke layer ( rhp ) equals the mass flow rate out of the vent ( rh o ).

6-1.1.3 The vent area calculated for equil ibrium condit ions would correspond to the area needed for a long-term steady fire, or the area n e e d e d at the e n d of a design interval for a very slow-growing fire. For shor ter t e rm steady fires and for faster growing fires, tile calculated equUibrium vent area will prevent the smoke interface f rom descend ing completely to the bo t tom of the curtain boards. Therefore, equi l ibr ium calculations represent a safety factor in the design.

6-1.2 Mass Flow Rate in Plume, rhp. 6-1.2.1 The mass flow rate in the p lume depends on whether locations above or below the m e a n flame he igh t are considered (i.e., whether the f lames are below the smoke interface or reach into the smoke layer). The f lame height, L, is calculated from equat ion 6-1 [Heskestad 1995] as follows:

L = -1 .02D + 0.235Q 2 /5 (6-1)

(L and D in m; Qin kW).

where: D = base d iameter of fire Q = total hea t release rate

6-1.2.2 W h e n the m e a n flame height, L, is below the interface an d z is at or above the f lame he igh t bu t at or below the interface height, the mass flow rate in the fire p lume is (see 6-1.4.2 for application):

( , / * p i n k g / s e c , Qc in k W , a n d z a n d z o i n m )

where: Qc = convective hea t release rate (approx. 0.7 Q) z = he igh t above tile base of the fire zA = he igh t of "virtual origin" above the base of the fire (below the

u . . base of the fire, tf negative)

6-1.2.3 W h e n z is at or below the f lame he igh t and at or below the interface, the mass flow rate can be expressed as follows [Heskestad 1995] (see 6-1.4.2 for application):

~/*p = 0 . 0 0 5 6 Qc " z~ L (6-3)

It should be no ted that, at the mean f lame height, the mass flow rate is:

'/*pL = 0 . 0 0 5 6 Qc (6-4)

6-1.2.4 The virttlal origin, Zo, is the effective point source of the fire p lume [Heskestad 1995]:

z o = 0.083 Q2/5 _ 1.02D (6-5)

(Q in kW, D in m)

N F P A 2 0 4 M - - A 9 7 R O P

6-1.2.5 For combust ibles that extend in depth , such as storages, tile base of the fire is selected in a horizontal plane conta in ing die worst- o, se ignition location (i.e., the lowest poin t of the combust ible array). Consequently, the base of the desigrl fire is often selected on the floor of the building.

6-1.73 Mass Flow Rate Th rough Vents, th v .

6-1.73. l The inlet a rea for fresh air in the building below die design level of the smoke interface, A b can thrott le the inlet flow if it is no t sufficiently large. The effective vent area with throt t led inlet area is smaller than the un thro t t l ed area, and tile calculated vent area, Av, should be increased by the following multiplier, M, [Hinkley 1988]:

M = [ 1 + (Av/A/ )2(To/T) ] 1 /2 (6-6)

In this case, T o is the ambien t t empera ture and T is the smoke layer temperature . Where T = 350 K, T O = 2973 K, and the vent area and inlet ,area are the same (Av/A i = 1), the multiplier is 1.99. Increasing the inlet area to twice the vent ,area, so dlat Av/A i ~ 0.5, tile multiplier is 1.08. Reducing die inlet a rea to 1 / 9 the vent area, so that Av/A i = 2, the multiplier is 1.90. T he requi red vent areas, Av, de t e rmined by 6-1.4, should be adjusted us ing die appropria te multiplier f rom eqnat ion 6-6, including the effects of the tempera- ture ratio, T o / T .

6-1.3.2 Equat ing die buoyancy head across tile vent t o t h e dynamic head in the vent, f rom Bernoull i 's equat ion, provides die following:

1 /2 pu 2 = Apgd (6-7)

where p is file smoke layer density, Ap = Po - P, Po is die ambien t density, u is tile gas velocity in die vent, and g is the acceleration of gravity. The ma.qs flow th rough the vent is file product of gas density, velocity, and aerodynamic area (AVa), which, with die aid of equat ion 6-7 and the ideal gas law, becomes:

r 2 "~I/2[ToAT] 1/2 'hv=12P° gJ [TJ AVadl/2 (6-8,

In this case, T is tile smoke layer tempera ture and AT = T - T O .

6-1.73.3 It should be noted that the factor [ (T o A T ) / T 2} 1 /2 is quite insensitive to t empera ture as long as the smoke layer tempera ture rise, AT, is no t small. For example, a ssuming T o -- 294 K (21°C), the factor varies t h rough 0.47, 0.50, and 0.47 ,as die smoke layer t empera tu re rise varies th rough 150 K, 320 K, and 570 K. At a t empera tu re rise o f t 0 K, the factor is 0.38, and, a t a tempera ture rise of 20 K, it is 0.24, about 1/2 its m a x i m u m value. Consequendy, roof vent ing by natural ventilation becomes increasingly less effective as the smoke layer t empera ture decreases. For low smoke layer temperatures , powered ventilation as covered in NFPA 92B, Guide for Smoke Managcnurat .Systems in Malls, Atria, and Large Areas, should be considered.

6-1.3.4 A representat ive smoke layer t empera ture rise, AT, can be est imated as a fr:tction, r, of the adial)atic t empera ture rise, AT a as follows:

A T = r A T = r Qc/(Cplh p ) (6-9)

where cn is the specific heat of air at consmntp res su re . Tile p lume mass flokv, ,h~, is evahmted f rom equat ions 6-2or 6-3, with z = H - d (where H is tile ceiling he igh t above file base of the fire). Equat ion 6-2 is used if the f lame height, L (equat ion 6-1), is smaller than (H - d) and equat ion 6-3 is u sed if tile flame height, L, is larger fllan (H - d). From expe r imen t [Hinkley 1992], it is evident that file fraction, r, decreases with the distance from tile fire, but a representative value, r = 0.5, can be used. Adopted values of tempera ture rise should be limited to 1000°C.

6-1.4 Required Vent Area.

6-1.4.1 The required actual vent area is file m i n i m u m total area, A v, of all the open vents in a cur ta ined compar t men t needed to prevent the smoke from underspi l l ing the curtain boards or f rom descend- ing below tile design level of dle smoke interface.

6-1.4.2 The area, Ava, calculated according to file procedures in 6-1.4 is the aerodynamic vent area, which is always smaller titan the

geometr ic vent area, A v. For simple apertures, Awl can be taken as 0.61 t imes file geometr ic throughf low area. In o ther words, the calculated vent areas, Ava, shou ld be increased by a factor of 1/0.61 to establish the geometr ic vent area. If the discharge coefficient is different f rom 0:61, the calculated vent areas should be multiplied by the ratio of 0.61 to th¢ actual discharge coefficient.

6-1.4.3 The calculated vent areas also should be increased by the multiplier, M, in equat ion 6-6 to account for l imited inlet area for fresh air.

6-1.4.4 The required aerodynamic vent area, Ava, is calculated with tile aid of equat ions 6-1, 6-2, 6-3, 6-5, 6-8, and 6-9, set t ing z = H - d, where H is file ceiling he igh t above the base of the fire (usually the f oo r ) . This vent area is distr ibuted a m o n g individual vents within the cur ta ined compartment_

6-1.4.5 Steady Fires (Limited Growth Fires).

6-1.4.5.1 For steady fires, or fires that do not develop beyond a maximum size, the required vent area per curtained compartment is calculated based on the m a x i m u m ant icipated heat release rate, Q and Q o the associated distance f rom the fire base to the bo t tom of the curtain boards or to the design elevation of the smoke interface, H - d, and the es t imated fire diameter , D.

6-1.4.5.2 These fires include special-hazard fires and fires in occupancies with concentra t ions of combust ibles separated by sufficiently wide aisles. The m i n i m u m aisle width to prevent lateral spread by radiation, Wmi n [Alpert and Ward 1984], can be est imated from equat ion 6-10 for radiant heat flux from a fire and a consergatively low value for file ignition flux of most materials (20.4 k W / m ' ) :

Wmi n = 0.042 Q 1 / 2 (6-10) ( Q i n kW, Wmi n in m)

Tile values p roduced by equat ion 6-10 can be produced from equat ion 5-10 i fX r is assumed to be 0.5.

6-1.4.5.3 The fire diameter , D, is taken as the d iameter of a circle having file same area as the floor area of fl~e fuel concentrat ion.

6-1.4.5.4 Tile heat release rate is taken as the heat release rate per uni t area t imes the floor area of the fuel concentrat ion. The m a x i m u m foreseeable storage he igh t (above the fire base) and associated heat release rate s h o u l d b e considered.

6-1.4.5.5 The heat release rate per uni t area migh t be available f rom listings for a given storage height, such as Table 5-5.2(b). To establish estimates for o ther than specified heights, it can be as sumed that the hea t release rate per un i t area is proport ional to die storage height, based on tests hyYu [Yu 1991] and the data in Table 5-5.2(b) for wood pallets. For fuel configurat ions that have not been tested, the procedures of Chapter 5 should be used.

6-1.4.5.6 The re is a distinctpossibili ty tha t a combustible storage array could collapse before die end of the design interval of the vent ing system. (The design interval migh t end, for example, when manua l fire f ight ing is expected to begin.) The fire d iameter increases, contr ibut ing to increased smoke product ion (via a lower f lame he igh t and virtual origin). However, the hea t release rate and fire growth rate after collapse are likely to be smaller than with no collapse. Consequently, it is reasonable to assume that the net effect of collapse is no t significant for the calculation procedure.

6-1.4.6 Growing Fires (Continuous-Growth Fires).

6-1.4.6.1" A t-squared fire growth is assumed:

Q = 1000 ( t / tg) 2 (6-1 l)

( Q i n kW; t a n d tg in s)

where t is the t ime f rom effective ignition (seeFigure 6-1.4.6.1) following an incubat ion period, and t~is the time, t, at which the fire exceeds an in termediate size of 11700 kW. The growfll t ime, tg, is a measure of the fire growth rate; the smaller tile growth time, the faster the fire grows.

595

N F P A 2 0 4 M ~ A 9 7 R O P

3000

_¢

aooo

"1"

1000

Continuously growing

Incubation

Time

J

~ < ~ G rowlh m t ime

I ~_._Effect ive ignition time

Figure 6-1.4.6.1 Conceptual illustration o f continuous-growth fire.

6-1.4.6.2 Instead of growth time, ,tg, t-squared fire growth can be expressed in terms of a fire growth coefficient, Ctg, ,as follows:

Q= c~gt 2 (6-11a)

(Q in kW, t i n s , ff.g in kWs "2)

Comparing equation 6-1 la and equation 6-11, the following relation exists:

t~g = 1 0 0 0 / t ~ (6-11b)

6-1.4.6.3 Growth times tot a number of combustible arrays have been obtained; see Table 6-1.4.6.3. These are specified for certain storage heights. Actual tests have demonstra ted [Yu 1991 ] that it is reasonable to assume that the instantaneous heat release rate per uni t height of the storage array is insensitive to the storage height. Such behavior corresponds to the gro~.h time, tg, being inversely proportional to the square root of the storage he~glm Alternatively, it corresponds to the fire growth coefficient, a~, being directly proportional to the storage height. For ex,'unO]e if the s torag%

times the growth time from the test. For fiael configurations that have not been tested, the procedures discussed in Chapter 5 migl!t be applicable.

6-1.4.6.4 A venting system needs to be able to mainuain the smoke layer above the design level from the time of ignition until the end of the design interval, tr, where t r is measured from the time of detection, t d.

At die end of the design interval, the heat rel~qse rate is:

Q = 1000[(t r + td ) / tg ) ] 2 (6-12)

(Q in kW; tr, td, and tg in s)

The end of the design interval, t r, may be selected to correspond to various critical events, including:

596

Table 6-1.4.6.3 Continuous-Growth Fires

Growth times of developing fires in various combustibles, assuming 100 percent combustion efficiency. (PE = polyethylene; PS = polystyrene; PVC = polyvinyl chloride; PP = polypropylene; PU = polyurethane; FRP = Fiberglass-Reinforced Polyester)

Growth Time (s)

1. Wood pallets, stacked 0.46 m high 160-320 (6-12% moisture) 2. Wood pallets, stacked 1.52 m high 90-190 (6-12% moisture) 3. Wood pallets, stacked 3.05 m high 80-120 (6-12% moisture) 4. Wood pallets, stacked 4.88 m high 75-120 (6-12% moisture) 5. Mail bags, filled, stored 1.52 m high 190 6. Cartons, compartmented, stacked 60 4.57 m high 7. Paper, vertical rolls, stacked 6.10 m 17-28 high 8. Cotton (also PE, PE/Cot 22-43 Acyrlic/Nylon/PE), garments in 3.66 m high rack 9. "Ordinary combustibles" rack 40-270 storage, 4.57-9.14 m high 10. Paper products, densely packed in 470 cartons, rack storage, 6.10 m high 11. PE letter trays, filled, stacked 1.52 180 m high on cart 12. PE trash barrels in cartons, stacked 55 4.57 m high 13. FRP shower stalls in cartons, 85 stacked 4.57 m high 14. PE bottles packed in Item 6 85 15. PE bottles in cartons, stacked 4.57 75 m high 16. PE pallets, stacked 0.91 m high 150 17. PE pallets, stacked 1.83-2.44 m higl~ 32-57 18. PU mattress, single, horizontal 120 19. PU insulation board, rigid foam, 8 stacked 4.57 m high 20. PSjars packed in Item 6 55 21. PS tubs nested in cartons, stacked 110 4.27 m high 22. PS toy parts in cartons, stacked 4.57 120 m high 23. PS insulation board, rigid foam, 7 stacked 4.27 m high 24. PVC bottles packed in Item 6 9 25. PP tubspacked in Item 6 10 26. PP and PE film in rolls, stacked 40 4.27 m high 27. Distilled spirits in barrels, stacked 25-40 6.10 m high

(a) Arrival of tile emergency response team;

(b) Arrival of fire fighters from public fire department;

(c) Complet ion of evacuation;

(d) Other critical events.

6-1.4.6.5 Tile instantaneous diameter of the fire needed for calculadon of L and z o can be calculated from the instantaneous heat release rate, O~ and data on the heat release rate pe r uni t floor area Q~ (according to listings such as in Table 5-5.2(f~) and

. n , ,

assuming Q is proporuonal to storage height):

, , , d / 2 v = [ 4 Q / ~ Q ) (6-13)

6-1.4.7 Detection.

6-1.4.7.1 Detection should be either by heat or smoke detectors installed at each vent, or by hea t or smoke detectors installed on a regular matrix.

6-1.4.7.2 The earlier the fire is detected, the earlier evacuation of the building can begin. Furthermore, for continuous-growth fires,

N F P A 2 0 4 M ~ A 9 7 R O P

the earlier the fire is detected and vents actuated, the smaller the fire size at the end of die design interval, and the smaller the required vent arem In the c~ase of limited-growth fires, the earlier the fire is detected and vents actuated, the less l ikelyan inidal underspil l of smoke at the curtain boards and smoke layer excursion to low heights.

6-1.4.7.2.1 For the G-alculations of the detect ion time, t d, of the first detector projected to operate and the detect ion t ime of the detector control l ing the actuat ion of the last projected vent to operate in a cur ta ined area prior to the end of the design interval, the design fire should be a s sumed f ~ h e s t possible f rom both detectors within die cur ta ined area.

6-1.4.7.2.1.1 Detection t imes for hea t detectors a n d fusible links, the latter serving as c o m m o n actuators for commercial hea t and smoke vents, can he de t e rmined with the ,aid o f NFPA 7'~, NationalFire Alarm COd~ provided the spacing between detectors does not exceed 15m.

6-1.4.7.2.1.2 If fl~e spacing between heat detectors (or fiasible links) exceeds 15 m, the detect ion t ime can be de te rmined f rom the following response differential equat ion [ Heskestad 1989(A) ]:

d ( a r , ) _ u - - [aT-aTe] (6-14)

dt RTI

where:

AT e = t empera tu re rise (from ambient) of heat-responsive e l ement

t = t ime u = gas velocity at detector site AT = gas t empera tu re rise (from ambient) at detector s i t e l /2 RTI = response tlme index [ Heskestad ,and Bill 1989] (gu ,

where ~ is the time constant of the heat-responsive e l emen t for convective heat ing).

Tide detection t ime is the time, t = t d, when T e reaches the value associated with the rated t empera tu re of the heat-responsive element .

6-1.4.7.2.1.$ In the case of cont immus-growth t-squared fires, gas tempera tures for the calculation in equat ion 6-14 ~ua be de t e rmined f rom the following [Heskestad and Delichatsios 1989]:

(6-15)

(T in °C, tg in s, arid H in m).

where the interpretat ion A T=O is applied when the numera to r of the first bracket is zero or negative and:

H = ceiling he igh t above the fire I~ase r = radius f rom fire axis

6-1.4.7.2.1.4 Gas velocities for the calculation in equat ion 6-14 can be evaluated f rom a relation between gas velocity and t empera tu re as follows [ Heskestad and Delichatsios ! 989]:

u / [ ( A T / " d / 2 To )gH 1 = 0.59(r / H) -0"63 (6-16)

where:

T O = ,ambient air t empera ture g = acceleration of gravity

6-1.4.7.2.2 Detection times for smoke detectors can be de te rmined with the aid of equat ion 6-15 as the time to reach a certain tempera- ture rise, AT, at response, which is ,also the foundat ion for smoke detector spacing curves in NFPA 72, NationalFireAlarm Codg This t empera ture rise shoukl be de t e rmi ned in dedicated tests, or the

equivalent, for the combust ible of the occupancy and the detector model to be installed. A tempera ture rise of 1O°C or less at detect ion is considered representat ive of a reasonably sensitive detector for a specific combustible.

6-1.4.7.2.3 The response data in NFPA 72, NationalFireAlarm Code, as well as the tempera ture a n d velocity relations in equat ions 6-15 and 6-16 assume extensive, flat, horizontal ceilings. T h i s assump- tion migh t appear optimistic for installations involving beamed ceilings. However, a n y d e l a y i n operat ion due to beams is at least partially offset by opposite effects of:

(a) Heat banking up unde r the ceiling because of curtain boards or walls; and

(b) The neares t vent or detector usually being closer to the fire than the assumed, greatest possible distance.

6-1.4.7.$ Detection Computer Programs.

6-1.4.7.3.1 A compute r program, known as DETACT-T2 [Evans and Stroup 1985], is available for calculating detect ion times of heat detectors in continuous-growth, t-squared fires, equivalent to solving equat ion 6-14 with tile aid of equat ion 6-16 and effectively a predecessor of equat ion 6-15. T h e program calculates detect ion times for smoke detectors (see 6-1.4.7.2.2) based on the effective predecessor. The effective predecessor [Heskestad and Delichatsios 1979] assumes complete combust ion of the test fuel used in the exper iments leading to the equation, whereas equat ion 6-15 is based on the actual hea t of combust ion. However, DETACT-T2 can still be used, provided the projected fire growth coefficient, 0~g, is mult ipl ied by the factor 1.67.

6-1.4.7.$.2 Ano the r compute r p.rogram, known as DETACT-QS [Evans and Stroup 1985] is avadable for calculating detect ion t imes of hea t detectors and smoke detectors in fires of arbitrary fire growth. Quasisteady gas tempera tures and velocities are assumed, i.e., instantaneously, gas t empera tures a n d velocities u n d e r the ceiling are a s sumed to be related to the hea t release rate as in a steady-state fire. For t-squared fires, this p rogram would be less accurate than DETACT-T2 (if the projected fire growth coefficient is increased as described in 6-1.4.7.3.1), especially for fast growing fires, but DETACT-QS does provide a means of hand l ing fires which canno t be approx imated as t-squared fires.

6-1.4.8 Selection o f Design Basis. The vent area in a cur ta ined c o m p a r t m e n t should not be required to exceed the vent area calculated for the largest limited-growth fire predicted for the combustibles benea th the cur ta ined area. Using sufficiendy small concentrat ions o f combust ibles and aisle widths at least as large as calculated f rom equat ion 6-10, it migh t be possible to satisfy the vent ing needs us ing smaller vent areas than required bya continu- ous-growth vent design.

6-1.5 Limitations.

6-1.5.1 A design for a given bui lding and its combustible contents and their distribution would comprise selecting a design basis (limited-growth versus cont inuous-growth fire) and establishing the following parameters:

(a) Layout of cur ta ined areas;

(b) A curtain depth;

(c) Type detector and specific characteristics;

(d) Detector spacing;

(e) An appropriate design interval, tr, following detect ion for main ta in ing a clear layer (for cont inuous-growth fires);

(f) Total vent area per cur ta ined compartlnentg

(g) Disu'ibution of individual vents; and

(h) An air inlet area.

Certain limitations ~ffventing designs should be observed.

6-1.5.1.1 The distance f rom the fire base to the smoke interface, H - d, is a d o m i n a n t variable. Some design situations can result in smoke layer tempera tures as expressed in equat ion 6-9 (with r = 0.5) that exceed 600°C, at which fire can flash over to all the combus- tibles u n d e r die cur ta ined area, which clearly represents an

597

N F P A 2 0 4 M ~ , A 9 7 R O P

unacceptable design. Temperature limits exist for structural members. For example, structural steel has lost approximately half of its strength at a temperature of 540°C. Initiation of chart ing of wood members is typically assumed to occur at 280°C. The temperature of unprotected steel and surfaces of wood will closely follow the exposing smoke temperature. Practical options include enforcing limits on areas of rue/concentrat ions, heights of the combustible, or both, to limit heat release rate to levels low enough to prevent the occurrence of unacceptable design temperatures.

6-1.5.1.2 Danger to unprotec ted steel directly over the fire depends on local temperatures over the fire in the smoke layer, which reach the 540°C limit earlier than the average smoke layer temperature calculated using r = 0.5 in equation 6-9. In equation 6-9, r = 1 should be used to ,assess this limitation, which necessitates further restricting the storage height of the combustible.

6-1.5.2 The feasibility of roof venting should be quest ioned when the heat release rate approaches values associated with ventilation control of die burning process (i.e., where the fire becomes controlled by the makeup air replacing die vented hot gas and smoke). Ventilation-controlled fires might be unable to support a clear layer. Tiffs limiting heat release rate is te rmed Qfeasible and can be estimated from the following [Heskestad 1991 ]:

Qfeasible = 23,200 ( H - d ) 5 /2 (6-17)

(Qfeasible in kW; H ,and d in m)

Venting at heat release rates greater than Qfe,~ible to maintain a clear layer necessitates larger vent areas than tinose indicated by the calculation scheme provided.

6-2 Models.

6-2.1 Mathematical Models to Simulate Fire-Generated Environ- ments and the Action of Vents. A ceiling vent design is successful to the extent that it controls a fire-generated environment developing in a space of fire origin according to any of a variety of possible specified criteria. For example, if the likely growth rate of a fire in a particular burning commodity is known, a vent system with a large enough vent area, designed to provide for timely opening of the vents, can be expected to lead to rates of smoke removal that are so large that fire fighters, arriving at the fire at a specified t ime subsequent to fire detection, are able to attack the fire successfully and protect commodities in adjacent spaces from being damaged.

To evaluate the success of a particular design it is necessary to predict the development of the fire environment ,as a function of any' of a number of physical characteristics dlat define and might have a significant effect on the fire scenario. Examples ofsucin characteris- tics include:

(a) The floor-to-ceiling height and area of the space ,and the thermal properties of its-ceilihg, walls, and floor;

(b) The type of barriers that separate the space of fire origin and adjacent spaces (e.g., full walls v~th vertical door-like vents or ceiling- mou n ted cu ru'fin boards);

(c) The material type and ~ n g e m e n t of the burning commodi- ties (e.g., wood pallets in plan-area ,'ua'ays of 3 m x 3 m ~/nd stacked 2 m high);

(d) The type, location, and method of deployment of devices that detect the fi?e and actuate the opening of the vents (e.g., filsible links of specified RTI and distrilAuted at a specified spacing distance below the ceiling); and

(e) The size of the open area of the vents tlaemselves.

The best way to predict the fire environment and evaluate the likely effectiveness of a vent design is to use a reliable mathematical m o d e l that simulates the various relevant physical phenomena that come into play during the fire scenario. Such an analytical tool should be designed to solve well-formulated mathematical problems, based on basic relevant principles of physics and fundamentally sound, well- established, empirical relationships.

Even in the case of a particular class of problem, such as an engineering problem ,associated with successfitl vent design, there is a good d e a l o f variation among applicable mathematical models that could be developed to carry out the task. Such models might differ from one another in the number and detail of the individual physical p h e n o m e n a taken into account. Therefore, the list o f physical characteristics that define and could have a significant effect on the fire scenario does not include outside wind conditions, which

could have an important influence on the fire-generated environ- ment. A model might or might not include the effect of wind. A model that does include the effect of wind is more difficult to develop and validate and more complicated to use. Note that the effect of wind is not taken into account in the LAVENT model discussed in 6-2.2. However, by using reasonably well-accepted matiaematical modeling concepts, LAVENT could be developed to the point where it could be used to simulate this effect.

In 6-2.2, a group of phenomena described that, taken together, represent a phys=cal basis for estimating the f i re-generated environ- men t and tile response of fusible links in well-ventilated compart- ment fires with curtain boards and fusible link-actuated or smoke detector-actuated ceiling vents. The phenomena include:

(a) Growth of the smoke layer in the curtained compartment;

(b) The flow dynamics of the buoyant fire plume;

(c) The flow of smoke through open ceiling vents;

(d) The flow of smoke below curtain boards;

(e) Continuation of the fire plume in the upper layer;

(f) Heat transfer to the ceiling surface and the thermal response of the ceiling;

(g) The ve loc i tyandtempera ture distribution of plume-driven, near-ceiling flows; and

(h) The response of near-ceiling-deployed fusible links and smoke detectors.

All tire p h e n o m e n a in (a) through (In) are taken into account in the LAVENT model, which was developed to simulate the above class of fire environment. Other models that could be developed for a similar purpose would typically be expected to simulate these basic phenomena also.

6-2.2 The Physical Basis for the Fire Model LAVENT.

6-2.2.1 The Basic Fire Scenario. The space to be considered is def ined by ceiling-mounted curtain boards with a fire and with near- ceiling fusible link-actuated ceiling vents and sprinklers. The curtained area should be considered as one of several such spaces in a large building compartment . Also, by specifying that the curtains be deep enough, they can be thought of as simulating the walls of a single uncurta ined compartment . This subsection discusses critical physical p h e n o m e n a that determine the overall environment in the curtained space up to the time of sprinkler actuation. The objective is to identify and describe the p h e n o m e n a in a manner that captures the essential features of this generic class of fire scenario and allows for a complete and general, but concise and relatively simple, mathemat ica l /computer simulation.

The overall building compar tment is assumed to have near-floor intake air openings that are large enough to maintain the inside environment, below any near-ceiling smoke layers that might form, at outside-ambient conditions. Figure 6-2.2.1 depicts the generic fire scenario considered. It is assumed that a two-layer zone-type model describes adequately the p h e n o m e n a under investigation. The lower layer is identical to the outside ambient. The upper smoke layer thickness andproper t i e s change with time, but, at any time, the layer is assumed to be uniform in space. Conservation of energy and mass along with the perfect gas law is applied to the upper layer. This leads to equations that necessitate estimates of the ne t rate of enthalpy flow plus heat transfer and the net rate of mass flow to the upper layer. Qualitative features of the phenomena that contribute to these flows and heat transfer are described briefly.

Draft curtain Ceiling vents Ceiliflg jet

" C r t

Figure 6-2.2.1 Fire in a building space with curtain boards and ceiling vents.

598

N F P A 2 0 4 M - - A 9 7 R O P

6-2.2.2 Flow through the Ceiling Vents. Flow is driven th rough ceiling vents by cross-vent hydrostatic pressure differences. T he traditional calculation uses orifice-type flow calculations. Bernoull i 's equat ion is applied across a vent, and it is a s sumed that, away f rom ,and on ei ther side of tile vent, the env i ronmen t is relatively lquiescent. Figure 6-2.2.2 depicts the known, instantaneous, lydrostatic pressure distr ibution in die outside env i ronmen t and

t h roughou t the dep th of tile cur ta ined space. These are used to calculate the reslrlting crogs-vent pressure difference, and then the actu,'d ins tan taneous mass and entbalpy flow rates t h rough a vent.

l ap across

I ceiing Pressure in I vent curtained

X ' . / " space

Cor o.,side

Pressure

Ceiling vent

ill I Y

f

YCEIL

Is Figure 6-2.2.2 Flow through a ceiling vent.

6-2.2.3 Flow below the Curtain Boards. If and when the layer interface drops below the bot tom of the curhain boards, the smoke starts to flow out of the cur ta ined space. AS with the ceiling vents, this flow rate is de t e rmined by the cross-vent hydrostatic pressure difference. AS depicted in Figure 6-2.2.3, however, in this case, the pressure difference is not constant across die flow. Nonetheless, even in this configuration, file ins tantaneous flow rates are easily de t e rmined with well-known vertical-vent flow equat ions used traditionally in zone-type fire models.

Pressure in curtained

. d space

Pre next .~oa~ "~C,. (or outside) ' ~

Pressure

f

I / YCUR

I' s

Figure 6.2.2.3 Flow below a curtain board.

6-2.2.4 The Fire, the Fire Plume, and Radiation Heat Transfer . The major contr ibutors to the upper layer flow and surface hea t transfer are the fire and its plume. This is depicted in Fignre 6-2.2.4. It is a s sumed that the rate of energy release of the fire's combust ion zone does not vary significantly f rom knowal free-burn values that are available and assumed to be specified (see Chapter 5). A known, fixed fraction of dais energy is a s sumed to be radiated isotropically,

as in the case of a point source, from the combus t ion zone. The smoke layer is a s sumed to be relatively t ransparen t (i.e., all radiation f rom the fire is incident on the b o u n d i n g surfaces of the compart- ment ) .

A p lume model is selected f rom the several available in the literature, and this is used to de te rmine the rate of mass and enthalpy flow in the p lume at the elevation of the layer interface. It is a s sumed that all of dais flow penetrates the layer interface and enters the uppe r layer.

As die p lume flow enters die upper layer, the forces of buoyancy that act to drive the p lume toward tile ceiling are reduced immedi- ately because of the tempera ture increase of the upper layer env i ronment over that of the lower ambient . AS a result, the cont inued ascent o f the p lume gases is less vigorous (i.e., at reduced velocity) than it would be in fine absence of the layer. Also, as they cont inue their ascent, the tempera ture of the p l u m e gases is h igher than it would be without the upper layer. Such h igher tempera tures are a result of the modif ied p lume ent ra inment , which is now occurr ing in die relatively high tempera ture upper layer rather than in die ambient - tempera ture lower layer. Methods of predict ing the characteristics of the modif ied upper p lume flow are available.

Convective heating: To relatively cool from relatively ho ,aterial ceiling jet

Reradiation from ceiling to relatively ~ cool floor

heating "les

Figure 6.2.2.4 The fire, the fire plume, and heat transfer to the ceiling.

6-2.2.5 Convective Heat Transfer to the Ceiling. Having penet ra ted the interface, the p lume cont inues to rise toward the ceiling of the cur ta ined compar tment . As it impinges on the ceiling surface, the p lume flow turns and forms a relatively h igh temperature , h igh velocity, tu rbu len t ceiling j e t dlat flows radially outward along the ceiling and transfers hea t to the relatively cool ceiling surface. Th e ceiling j e t is cooled by convection and the ceiling material is hea ted by conduct ion. Eventually, the now-cooled ceiling j e t reaches the extremities of the cur ta ined space and is deposi ted into and mixed with the uppe r layer. The convective hea t t ransfer rate and the ceiling surface t empera tu re on which it depends are both s t rong funct ions of the radial distance from the point of p lume/ce i l ing impingement , decreasing rapidly with increasing radius.

6-2.2.6 Thermal Response of the Ceiling. The thermal response of the ceiling is driven by t ransient hea t conduct ion. For the t ime period typically considered, radial gradients in ceiling surface condit ions are small e n o u g h so that the conduct ion hea t transfer is quasi-one-dimensional in space. Therefore , the thermal response of the ceiling can be o b t a i n e d f r o m the solution to a set of one- d imensional conduct ion problems at a few discrete radial positions. These can be solved subject to ne t convection and radiation heat flux boundary conditions. Interpolation in the radial direction between the solutions leads to a sufficiendy smood~ representat ion of the distr ibutions of ceiling surface tempera ture and convective hea t transfer rate. The latter is in tegra tedover file ceiling surface to obtain the ne t ins tantaneous rate of convective heat transfer losses f rom tile ceiling jet .

6-2.2.7 The Cei l lngJet and the Response o f Fusible Links. Convec- tive hea t ing and the thermal response of a near-ceiling fusible link

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are detenaained from the Iocdd ceiling j e t velocity and temperature. Velocity and temperature depend on vertical distance below the ceiling and radial distance from the fire plume axis. If and when its fuse temperature is reached, the device(s) operated by the link is actuated.

For specific radial distances that are relatively near to tim plume, the ceiling je t is ,an inertially-dominated flow. Its velocity distribu- tion, depicted in FigaJre 6-2.2.7(a), can be estimated from the cllaracteristics o f the phune, upstream of ceiling impingement . The ceiling je t temperautre distribution, depicted in Figure 6-2.2.7(b) for a relative "hot" or "cool" ceiling surface, is dlen estimated from the velocity (which is now known), upper layer temperature, and ceiling- surface temperature and heat flux distributions.

A T c j = T C j - T U = ceiling-jet teml)emture - - upper layer

temperature.

l (x \ \ \ "~ )

0

Distance below ceiling

VMAX

~ \ \ \ \ \ \ \ \ \ \ \ \ \ " , ~ \ \ \ \N" / "

Figure 6-2.2.7(a) Ceiling-jet velocity.

~'xXXXXXXXXX\N~

Distance below ceiling

~ \ \ ~ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ N " ( "

f " "Cool" ceiling, high heat transfer

Figure 6-2.2.7(b) Ceiling-jet temperature.

6-2.3 The LAVENT Model Equations and Computer Code.

6-2.3.1 T heM ode l Equations: Guidelines, Assumptlons, and Limitations. Appendix B provides details of all equations of the LAVENT mathematical fire model, and its associated computer program developed to simulate all the phenomena described in 6- 2.2. LAVENT can be used to simulate and study parametrically a wide range of relevant fire scenarios involving these phenomena .

Included in B-5.5 is a summary of gnidelines, assumptions, and limitations to LAVENT. For example, as specified in that paragraph,

600

LAVENT assumes that, at all times during a simulated fire, the overall building space containing the curtained area of fire origin is vented to the outside (e.g., through open doorways). It is assumed, furthermore, that the area of the outside vents are large relative to the area of the open ceiling vents in the curtained compartment. Therefore, if,~he total area of the outside vents is AOU T, then (AOUT/AV) ~ is significantly larger than 1 (e.g., A O u T / A V > 2). If the outside vents are in the bounding walls o f the curtained space, and not in adjacent spaces, they should be located entirely below the layer interface. Paragraph B-5.5 should be referenced for the details of od~er guidelines, ,assumptions, and limitations.

6-2.3.2 A User Guide for the Computer Code. Appendix C is a user guide for the LAVENT computer code. The appendix includes a comprei~ensive discussion of the inputs and calculated results of a default siomlation involving a fire growing in a large pile of wood pallets (t~-type growth to a steady 33MW) in a 9.l-m high curtained warehouse-type space with multiple fusible-link-actuated vents and near-ceiling-deployed fusible sprinkler links. Inputs to LAVENT include those specified in 6-2.3.2(a) through (f).

(a) Dimensions of the Curtained Compartment of Fire Origin. Length, width, ,and height of the curtained compar tment of fire origin.

(b) Dimensions of the Curtain Board. Floor-to-bottom-of-the- curtain separation distance and length of the curtain (a portion of the perimeter of the curtained space can include floor-to-ceiling ~ l l s ) .

(c) Propert ies of the Ceiling. Thickness, density, thermal conductivity, and heat capacity of the ceiling material.

(d) Characteristics of the Fire. Elevation of the base of the fire above the floor (see 6-1.2); total energy release rate of the fire, Q , at different times during the course of the simulated fire sce.na~io (the computer code uses linear interpolation to approximate Q between these times); and the plan area of the fire, or the total energy release rate per unit area of the fire (in cases where the user supplies the latter input, the computer code estimates the changing area of the fire at any momen t by using the current total energy release rate).

(e) Characteristics of the Ceiling Vent-Actuating Fusible Links or Vent-Actuating Smoke Detectors and of the Corresponding Ceiling Vents. Horizontal distance from the fire, vertical distance below the ceiling surface, response time index (RTI), and fuse temperature of the ceiling vent-actuating fusible links; also, the clear open area, A V, of their associated ceiling vents.

NOTE 1: ff ceiling vents are actuated by smoke detectors, the guidelines outlined in 6-1.4.5.2.2 should be followed. LAVENT can be made to simulate this function with a very sensitive fusible link (i.e., a link with a negligibly small RTI) and an appropriate fllse temperature.

NOTE 2: As specified in B-4.1, LAVENT always assumes that the flow coefficient, CD, for ceiling vents is C D = 0.68; if the user has reason to believe that a different value, C D USER, is more appropriate for a particular vent (such as ~ e value 0.61 suggested in 6-1.4.2), then the input vent area for that vent should be scaled up proportionately (i.e., AV, INPU T = A V CD,USER/0.68).

(f) Characteristics o f Fusible Sprinkler Links. Horizontal distance f rom the fire; vertical distance below the ceiling surface; and response time index (RTI) and fuse temperature of fusible sprinlder links.

NOTE: LAVENT calculates the time that the first sprinkler link fuses and the fire environment that develops in the curtained space prior to that time. Since the model does no t simulate the interaction of sprinkler sprays and fire environments, any LAVENT simulation results subsequent to sprinkler waterflow should be ignored.

6-2.3.3 Computer Requirements. LAVENT is written in FORTRAN 77. The executable code operates on IBM PC-compatible computers and necessitates a minimum of 300 kilobytes of memory.

6-2.4 Experimental Validation o f LAVENT. LAVENT has lgtd some limited experimental validation in experiments with 3.34 rn g pool fires in a 37 m x 40 m x 14 m high aircraft hanger [Walton and Notariannl, 1993; Notarianni, 1993]. The hanger was equipped with near-ceiling mounted brass disks of known RTlwhich were used to simulate sprinkler links or heat detector elements. The experiments

t

N P P A 204M - - A97 R O P

did*not Involve ceiling venm. Experimental validation of the various mathematical rob-model equation sets that comprise the generalized LAVENT simulation is also impl~cit. This b the case since the ~,mb-models of L&VENT, presented ha ~ B, _ are based 6 n and carefully.reprOduced-c~rrelaflom of_ ace~ired in appropriate experimental studies of the isolated physical. phenomena that, taken together, makeup the c o m ~ . effects*of.a LAVENT-simulated fire scenario. To learn of the experimental basis and validation o f d ~ LAVENT mbmodels, the reader is referred to • L~ References for Appendix B.

Chapter 7 Mechanical Exhaust Systems

7-1 General. For mechanical veuting systetm capable offun~ionlng under the expected fire exposure, e xlmust.rates.pef curtained . compartment arecalculated from equations 6-2 or 6-fi, with the aia ofequadous 6-1 and 6-5. Gas temperatures are calculated from equation 6-9.

7-2 System Conversion. f fa gravity venting system ltm been designed and the projected gas tem pe/n~, r e rise inthe smoke layer exceeds. IS0°C, convenion to an eqmvalent mechanical system can be doneusiu 8 Table 7-2.

Table 7-2

Mechanical ~ Cap,eUy Design l)ep/h of SmOke per Unit Area Of Gnnd~ Vent

1.8 . 2.15

2.4 ~.47

$.o ~.76

~.6 ~,0~ 4.8 8.49

6.0 3.91

7.2 4.28

7-s Intake Air. Adequate intake air should be provided to make up air for mechanical exhaustsystems. Such intake might be powered or noupowered.

Chapter 8 Vemiog in Spriuldered Buildtn~

&l Introduction, The previous chapters represent the state of technology of vent and curtain board desi~- in the almencesff sprinklers. A broad/y accepted equivalent design basis for using sprinklers, veuu~ and curtain boards together for ha:uwd control (e.g., property protection, life safety, water usage, obscuration) has not l~en universally recognize&-" ,,

&2 General. For occupandes that present a high challenge to sprinkler systems, concern has been raised that.~he i n ~ of automatic roof venting or curtain boards, of both, can be de~-imen- tai to the perforrmu~.ce of automatic sprinlden~ Although khere ~, no universally accepted condmion flora fire ~ [MWer 1980], studies on a model scale [ Heskestad 1974]mggested the following:

(a) Ventin 8 delays loss of visibility.

(b) Venting results in increased fuel comump60" n. /

(c) Depending on the location of the fire, rela~ve to the vents, the nec __es~_,y ~ater demand to achieve control is either increased o r decreased over an unrented condition. With the fire directly under the vent, water demand is decreased. Whh the fire equidistant from the vents, water den~and is increased.

8-3 Automatic Roof Vents. A series of tests wasconducted to increase the understanding of the r01e of automatic roefvenm i • . simultaneously employed with autoh~ttc sprinklem [Waterman 1082]. Thedam submitteddid uot provide a consensus on whether sprinkler control was impaired or enhanced by the presence of a~tomatic (roof) vents for the typical spacing ~m'd area.

8-4 Curtain Boards; Large scale fire tests [Troup 1994] indicated " that the presence of curtain boards ca~ cause increases in sprinkler operation, smoke production, and fire dmnage (i.e., spriniders opened wall away from the fire).

s ~ OtherTma. Otheri.ars.e. scare .ere temp.'re, conducted [H|nkteyet ai 1992] .employing Hquld mere, smau vent spacings (minimum of 4.7 m), and venm open at 18ninon. Hinidey conduded that:

(a) the prior opening of vents had little effect on the operation of the first sprinkler, and

(b) venting suhstanthdly reduced the total number of sprinkler operations.

in an independent analysis of these t e s t s , , G u ~ noted that - sprinklers near the fire source were often delayed or did not operate altogether [Gwtabson 199"2].

8-6 Coacitmioas, Whlle the use of _m~t_ omatl~:venttngand curtain boards in spduldered _buildings is ~ under r ~ , the designer is encouraged t o m e the avallaHe t ~ l s m~ldata ref~'~a~-dr in t ~ document for soit~g problerm.~ m a.p~cular type oz hazard control [Mil[~ ~ ! 9 8 ~ : ' H ~ 1974,~Watemmn-I98~, Trotlp t994; Hinldey et al 19~; Gus~mc~ 1992]. t

9-1 Imporumee, Smoke ~ heat ven~ :m in the case of e ther fire

and maintenance t, mential _for ~ eqmpmont a m s~tems • that: are not subjected to-their l~endedme for manyyexn.

9-2 C~N~al .

9-2.1 Various types o f a p p r ~ _ _ a n ~ ¢ .thermal smokeand heat vents have been made a~dlable commercially. These vent, fall into two general ~*_~oories:

(a) Mech.nicdy Opened Ven~. F.~.-o~esind.de ,i~ng4~t, pneumatic-lift, or electric motor-driven venm.

(b) G r a w i ~ Veats,~ Examples indude PVC or acrylic drop- out pane~

9-L2 G e ~ / ~ m e d i C a l l y . o p t e d ven~ ate, provided with manual releasedevicm,that allow dirt~t activation; inspection or maintenance, or buth, wwell as repbu~.mem of ac~_.~_on compo-

nen~ (e.g., ~ m i v e cle~cei, thermal sensors, compressed gas cylinden, expl~luJbO. "

9.2.3 Gravity-openedventsdo not a i l ~ c t i v e o [ ~ W o n , hut i ~ o n of the ii~aUed,unit-is u e c e ~ to ensure ibe units are immlled In accocdam~with t r i c e p s ~ a n d acc e~ u~te _ _pr~ecen~ cm~l~mpmems~re in prate,

• unc~a~d.mi/'r~ee, o fsem~ d e b ~ m a . m ~ e ~ m s e~at miEht interfere with.the opermion and hmetion ~ e . u n i t .

9-2.4 The .inspection and maintenance .~ multiple&unction vents aim should enmure 4hat odntu funCdom a o not ~ the intended fire protection operation.

9.8 F r e q ~ o f l m l m ~ . ~ I m d ' M a ~

All deficiencies found should be corrected immediately.

9-S.2 M e c ~ Vents.

9-3.?,1 Iris important that aa~cep tance p e ~ o m ~ c e testand inspection ofaB ~ vents be condected immed~

cfi pr I~ y and tl~t in~allatinn is it. _ _.c~rdaace~with ~.he manufacturer s specili~tiom aml accepted trade practice~

9-$.~ It is necessary to follow the manu~_~_urer's recommentia- tiom re~i,'n 8 the maintenance and-rmpectiou schedule of mechanically4~perated venu..

9-~.2.S Inspection schedules should indude provisions for all units to be tested at 12-month interv'aJsor on aschedule based on a percentage of the total units to be tested every month or every two months. Such procedures improve reHabilRy.

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N F P A 2 0 4 M ~ A 9 7 R O P

9-3.2.4 Recordin~ of all pertinent characteristics of performance and logging of thts information to allow a comparison of results with those of previous inspections or acceptance tests allows a compari- son dlat provides a basis for determining the need for maintenance or modifying die frequency of the inspection schedule to fit the experience.

9-3.2.5 A change in occupancy or in materials being used, or in neighboring occupancies that could introduce a significant change in the nature or severity of corrosive amaospbere exposure, debris accumularion, or physical encumbrance, might necessitate a change in the inspection schedule.

9-3.2.6 Special mechanisms such ,as gas cylinders, thermal sensors, or detectors should be checked regularly on a schedule provided by the manufacturer.

9-3.3 Gravity-Opened Vents.

9-3.3.1 The same general considerations for inspection that apply to mechanically-opened vents (see 9-3.1) also pertain to gravity-opened vents. The dlermoplastic panels of these vents are designed to soften and drop out from the vent opening in response to the heat of a fire. This makes an operational test after installation impracti- cable. Recognized fire protection testing laboratories have developed standards ,and procedures for evaluating gravity-opened vents, including factory and field inspection schedules.

9-3.3.2 An acceptance inspection of all gravity-opened vents should be conducted immediately ,after installation. Compliance with tiae manufacturer's drawings and recommendations should be verified bydirect examination. A suitable installation should follow accepted trade practices.

9-3.3.3 Changes in appearance, damage to any components, fastening security, weather tightness, and adjacent roof and flashing condition should he noted at tile time of inspection.

9-3.3.4 Prompt and careful removal of any soiling, debris, or encumbrances that could impair the operation of the vent is essential.

9-$.4 Intake Air Sources. Where necessary for the operation of vent systems, intake air sources should he inspected at the same fre- quency ,as vents.

9-4 Conduct and Observation of Operational Tests.

9-4.1 Mechanically-Opened Ven t.,~.

9-4.1.1 Where feasible, release of file vent should simulate actual fire conditions. Disconnecting the restraining cable at the heat- responsive device (or other releasing device) and suddenly releasing file restraint, allows the trigger or latching mechanism to operate normally.

94.1.2 The heat-responsive device restraining cable is usually under considerable tension. Observation should be made of its whip and travel to determine any possibility that the vent, building construc- tion feature, or service pipingcould obstruct complete release. Any possible interference shouldbe corrected by removal of die obstruction, enclosure of cable in a suitable conduit, or other appropriate arrangement. Following any modification, die unit shouldbe retested for evaluation of adequacy of corrective mea- sures.

NOTE: The whipping action of the cable upon release presents a possibility of injury to anyone in the area. For this reason, the person conducting the test should ensure that all personnel are well clear of tile area where whipping of the cable might occur.

9-4.1.3 Latches should release smoothly. The vent should start to open immediately and move through its design travel to tile fully- opened position without any assistance and without any problems such as undue delay indicative of a sticking weather seal, corroded or unaligned bearings, and distortion binding.

9-4.1.4 Manual releases should be tested to determine that the vents operate.

9-4.1.5 All operating levers, latches, hinges, and weather-sealed surfaces should be examined to determine conditions such as any indication of deterioration and accumulation of foreign material, that might warrant corrective action or suggest the need for another inspection in advance of the normal schedule.

9-4.1.6 Following painting of the interior or exterior of vents, the units should he opened ,and inspected to check for paint that could "glue" surfaces together.

9-4.1.7 Painted heat-responsive devices should be replaced with devices having an equivalent temperature and load rating.

9-4.2 Gravlty-Opened Vents.

9-4.2.1 All weather-sealed surfaces should be examined to deter- mine conditions such as any indication of deterioration and accumulation of foreign material that might warrant corrective action or suggest the need for another inspection in advance of the normal schedule.

9-4.2.2 Following painting of dae interior or exterior of the frame or flashing of the vents, the units should be inspected to check for paint that could "glue" surfaces together.

9-5 Air Intakes.

9-5.1 Air intakes necessary for operation of smoke and heat vents should be maintained clear and free of obstructions.

9-5.2 Operating air intake louvers, doors, dampers and shutters should be examined to assure movement to full-open positions.

9-5.3 Operating equipment should be maintained and lubricated as necessary.

9-6 Ice and Snow Removal. Removal Of ice and snow from vents is an essential part of a vent maintenance program.

Chapter 10 Referenced Publications

10-1 The following documents or portions thereof are referenced within this guide and should be considered part of the recommenda- tions of this document. The edition indicated for each reference is tile current edition as of tile date of the NFPA issuance of fills document.

10-1.1 NFPA Publications. National Fire Protection Association, 1 Batterymarch Park, P.O. Box 9101, Quincy, MA 02269-9101.

NFPA 68, C, uitk for Venting of Deflagrations, 1994 edition.

NFPA 72, NationalFireAlarm Code, 1996 edition.

NFPA 92B, Guide for Smoke Manageraent Systems in Malls, Atria, and Large Areas, 1995 edition..

10-1.2 Other Publications.

10-1.2.1 ASTM Publication. American Society for Testing and Materials, 1916 Race Street, Philadelphia, PA 19105-1187.

ASTM E 1321, Standard Test Method for Daennining Materiat Ignition and F/ame Spread Properties, 1993.

ASTM E 1354, Standard Test Mahod for Heat and Visible Smoke Release Rates for Materials and Products Uslng an Oxygen Consumption Calorlm- eter, 1994.

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N F P A 2 0 4 M - - A 9 7 R O P

Appendix A Explanatory Material

This. A. ppendix is not. part of t h e . recommendations of this NFPA document but ts mclluted for reformational purposes only.

A-I-I.3 Large, undivided floor areas present extremely dil~cult fire- f ighting problems, since the fire d e p a r t m e n t migh t need to enter these areas in order to combat fires in central port ions of the building. If the fire d e p a r t m e n t is unable to enter beG~tuse of the accumula t ion of heat and smoke, fire-fighting efforts might be reduced to an application of hose s t reams to per imeter areas while fire cont inues in the interior. Windowless buildings also present similar fire-fighting problems. O n e fire protect ion tool that can be a valuable asset for fire-fighting operat ions in such buildings is smoke and heat venting.

A-l-2.1 The provisions of this guide may be permit ted to be applied to the top story of multiple-story buildings. The re are many features that would be difficnh or impracticable to incorporate into the lower stories of such buildings.

A-6-1.4.6.1 T-Squared Fires. Over the past de~tde, those interested in developing gener ic descript ions of the rate of heat release of accidental open f laming fires have used a "t-squared" approximat ion for this pnrpose. A t-squared fire is a fire in which the bu rn ing rate varies proport ionally to die square of time. Frequendy, t-squared fires are classed hy their speed of growth as fast, med ium, and slow (and occasionally ultra-f:L~t). Wilere these classes are used, they are de t e rmined hy the t ime needed for the fire to grow to a rate of hea t rele:~ge of 1000 kW. The t imes for each of these classes are provided in Table A-6-1.4.6.1.

Table A-6-1.4.6.1 Claxsiflcatlons o f T-Squared Fires

Cla.gs T ime to Reach 1000 kW Ultra-Fa.st 75 s Fast 150 s Medium 300 s Slow 600 s

For manyf i r e s involving storage arrays the t ime to reach 1000 kW migh t be m u c h shorter than the 75 seconds depec ted for ultra-fast fires.

The general equat ion is as follows:

Q = Ctgt 2

where:

Q = rate of hea t release (kW) t~__= a constant describing the speed of growth (kW/s 2)

= time (s)

Relevance of T-Squared Approximat ion to Real Fires.

A t-squared fire can be viewed as a fire in which the rate of heat release per uni t area is cons tant over the entire ignited surface and the fire spreads in circular fo rm with a steadily increasing radius. In such cases, the increase in the burn ing area is the square of the steadily increasing fire radius. Of course, o ther fires that do not have such a conveniendy regular fuel array and consistent bu rn ing rate migh t or migh t no t actually produce a t-squared curve. The tacit assumpt ion is that the t-squared approximat ion is close enoug h for reasonable design decisions.

Figure A-6-1.4.6.1 (a) demons t ra tes that most fires trove an incubation period dur ing which the fire does not conform to a t- squared approx ima t ion . In some cases, this incubat ion period might be a serious de t r iment to the use of the t-squared approximat ion. In most instances, this is not a serious concern in large spaces covered by dais guide. It is expected that the rate of heat release dur ing the incubation period would no t usually be sufficient to cause activation o f the smoke detection system. In any case, where such activation occurs or h u m a n observation results in earlier activation of dae smoke vent ing system, a fortui tous safeguard would result.

Continuously Growing

3000 A

O

p- ro 2000

== =-

i v I

-i- 1000

cubation

TIME

t.~iGrowt~ ~ Time

~ .._Ef fective Ignition Time

Figure A-6-1.4.6.1 (a) Conceptual illustration of continuous fire growth.

603

N F P A 2 0 4 M ~ A 9 7 R O P

Figalre A-6-1.4.6.1 (b), extracted from Nelson, Harold E., An Engineering A nal~sis of the Ear.l~ Stages of Fire Developnwnt----The Fire at the DuPont Plaza Hotel and Ca.¢ino, December 31, 1986, Report NBSIR 87- 3560, Nation:d Institute of Smncktrds and Technology, Galthersburg, Maryland, 1987, compares rote of heat release curves developed by the . ' fforementioned classes of t-squared fires and two test fires commonly used for test purposes. The test fires are shown as dashed lines labeled as furni ture and 6-ft storage. The d:Lshed curves fur ther f rom the fire origin show the actual rates of heat release of the test fires used in the deve lopment of the residential sprinkler and a s tandard 6-ft high mTay of test cartons containing foam plastic pails that also are frequent ly used as a s tandard test fi re.

Tile o ther set of dashed lines in Figure A-6-1.4.6.1 (b) shows these same fire curves relocated to the origin of the graph. This is a more appropriate compar ison with the gener ic curves. It can be seen that the rate of growth in these fires is actually faster than that prescribed for an ultra-fast fire. This is appropria te for a test fire des igned to chal lenge the fire suppress ion system being tested.

Figure A-6-1.4.6.1 (c) relates the classes of t-squared fire growth curves to a selection of actual fuel arrays.

Ultr -Fast Fast Medium 6000 F j Furniture / / 5000 F ' ' I i ~ " . _ _ ~ -- ' '6ftl" st 0 rag e

_ . . . . " - -

F , / / } ' / / j / $ I / . ' / ~ " / Display

s . _ _ . ~ " I I I J 0 100 200 300 400 500 600 "~u0

TIME FROM IGNITION (seconds)

Figure A-6-1.4.6.1 (b) T-squared fire, rates o f energy release.

Thin plywood wardrobe--

Fastest burning upholstered furniture 1

Ultra-Fast

Cartons 15 ft. high. various contents, V astest if empty or containing

plastic foam r---Full mail bags, 3 ft. high I r~Wood pallets ~ 5 ft. high 1 ~palletstack

/

Cnt tetrOs p~Pngl Y est e r - ~

Fast mattress Medium

5000

V 3000 F

0 100 200 300 400 500 600 700

TIME FROM IGNITION (seconds)

Figure A-6-1.4.6.1 (c) Relation o f t-squared fires to some fire tests.

604

N F P A 2 0 4 M - - A 9 7 R O P

Appendix B The Theoretical Basis o f LAVENT

This Appendix is not a part of th~ rt~om.um.dations of this NFPA document but is inchded for informational pmpose.~ on(~.

B-1 Overview. In tills Appendix, the physical basis and an associ- ated mathematical model fl)r estimating the fire-generated environ- ment :rod the response of sprinkler links in well-ventilated compart- ment fires with curtain boards and fiJsible-link-actuated ceiling vents is developed. Complete equations and assumptions are presented. Phenomena taken into account include the following:

(a) The flow dynamics of the upward-driven, buoyant fire plume;

(b) Growth of the elewated-temperamre smoke layer in the curtained compartment;

(c) The flow of smoke from the layer to the outside through open ceiling vents;

(d) The flow of smoke below curtain partitions to building spaces adjacent to tim curtail~ed space of fire origin;

(el Continuation of the fire plume in the upper layer;

(f) Heat transfer to the ceiling surface and the thermzd response of the ceiling :is a fnnction of radial distance from the point of plume- ceiling impingement;

(g) Tlae velocity and temperamredis t r ibut ion of plume-driven near-ceiling flows and the response of near-ceiling-deployed fusible links ,as functions of distance oelow the ceiling; and

(It) Distance front phmle-ceiling intpingement.

The theory presented here is the basis of the LAVENT computer program, that is supported by a user guide, presented in Appendix C, and that can be used to study parametrically a wide range of relevant fire scenarios [1, 2, 3].

B-2 Introduction. The space under consideration is a space of a plan area, A, defined by ceiling-mounted curtain boards with af i re of t ime-dependent energy release rate, ~( t ) , and with open ceiling V ' ~ - " ents of total tm~e-dependent area, At/[Q. The curtained ,area can be considered as o n e o f several such s~a'c'es in a large building compartment. Also, by specifying that die curtains be deep enough, they can be thonght of as simulating the walls of a single, uncurtained compartment . This appendix presents die pltysical ] . . . .

)asJs aa~a assocmted mathematical model for estimating the fire- generated environment ,and the response of sprinkler links in curtained compar tment fires with fitsible-link-actnated ceiling vents.

The overall building comparmtent is ,assumed to have near-floor wall vents that are large enough to maintain the inside environment, below any near-ceiling smoke layers that could form, at assumed initial outside-ambient conditions. Figure 6-.9.2.1 depicts dae generic fire scenario for the space under consideration. The ,assumption of large near-floor wall vents necessitates that the modeling be restricted to cond i tons where y, the elevation of the smoke layer interface, is above the floor elevation (i.e., y > 0). The assumption also has important implications with regard to the cross-ceiling vent pressure differer~tial. Tltis is the pressure differential that drives elewated-temperature upper layer smoke through the ceiling vents to the outside. Therefore, below fire smoke layer (i.e., from the floor of the facility to the elew, ttion of the smoke layer interface), die inside-to-outside hydrostatic pressure differential is zero, wlfile a positive inside-to-outside pressure differential exists at all elevations

the reduced-density smoke layer itself (higher pressure inside file curtained area, lower pressn re in rite outside environment) , the maximum differential occurring at the ceiling and across the open ceiling vents.

B-3 The Basic Equations. A two-layer zone-type compar tment fire model is used to describe the phenomena under investigation. As is typical in such models, the upper smoke layer of total mass, mu, is ,amumed to be uniform in density, PU ' and absolute temperatnre, T U •

The following t ime-dependent equations describe conservation of energy, mass, ,and the perfect gas law in the upper smoke layer.

Conservation of Energy:

d[(YCEIL - y ) P u T u A C u ] / d t = q u + p A d y / d t (B-l)

605

Conservation of Mass:

dm U / dt = m U (13-2)

mu = (YCEIL - Y)Pu A (B-S)

Perfect Gas Law:.

PU / R ~ p / R = constant = P u T u = PAMBTAMB (B-4)

i.e.:

T U = TAMBPAMB/Pu (B-5)

In the above, y is the elevation of the ceiling above the floor, R = C - C is ~t//gas constant, C and C are the specific heats at a c~stan~/pressure and volume, ~spectiv~y, and p is a constant characteristic pressure (e.g., ~ ) at the floor elevation In

• . p '

equanon B-l, (trr is the net r a ~ / e n t h a l p y flow plus heat transfer to the upper l a i r and is made up of flow components as follows:

, f rom below the curtain; = , f rom the plume; qCURT, from the ceiling vent; a n c ~ f ~ p o n e n t = , the total h ~ n s f e r rate. ~/HT

qu = qCURT +qPLUME +qVENT + q n T (13-6)

In equation B-2, rhty is file net rate of mass flow to tile upper layer with flow componen'(s; rhCURT, from below the curtain; ~ m t lMy, from the plume; and ~hVENT, from the ceiling vent. " ~ " ~

m U = tnCURT + thPLUM E + INVENT (B-7)

Using equation B-3 in equation B-1 leads to:

dy / dt = qu / ( A C pP AMB T AMB ) (13-8)

if (~ = Y('~ZL_ and qt, > 0 ); or (0 < Y > ' r~ 'rr and arbitrary qH ]- Sitl~ze b6fl~'o~ these ~onditibns are sa t i s f i ed~ '~a t ion 13-8 is always' applicable.

The basic problem of mathematicallysimulating the growth and properties of the upper layer for the generic Figure 6-2.2.1 scenario necessitates the solution of the system of equations 13-2 and B-8 for ~_~.. and y. Where m U > O, PU can be computed from equation

PU = (YCEIL - y)A / mu , i f m U > 0 (13-9)

.and T U can be determined from equation B-5.

B-4 Mass Flow and Enthalpy Flow Plus Heat Transfer.

!?.-4.1 Flow to the Upper Layer from the Vents. Conservation of momentum across all open ceiling vents as expressed by Bemoulli 's equation leads to the following:

V = C(2APCEI L / p u ) 1/2 (B-10)

"v r -pu v V =- vc(2pv pcF ) = (B-Il l

where V is the average velocity through all open vents, C is the vent flow coefficient (= 0.68) , and A,OCE/L is the cross-vent pressure difference [4].

From hydrostatics:

( a l e )

where g is the acceleration of gravity.

Substituting equation B-12 in equation B-11 leads to the desired INVENT result as follows:

N F P A 2 0 4 M - - A97 R O P

which is equivalent to die equations imed to estimate ceiling vent flow rates, Equation (6.8) and references [5 and 61. Using eqtmtion B-I 3, the desired qI,~NT result is as follows:

qVENT = 'hVENT CpTu (13-14)

B-4.2 Flow to the Layer from the Plume and Radiation from the Fire. It is assumed that tim ma~s generation rate of the fire is small compared to ~h ~ r , the rate of mass of air entrained into the plume between fi l l ' f i re elevation, 3 H R E , and the layer interface, or compared to other m,-Lcs flow rate components of rh U . It is ,also assumed that all of the rh l¢#trr penetrates the layer interface and enters the upper layer. TWei'$fore:

mt'LUME = ~hENT

qm~Me = 'neNT CpT AM~ +(1- ~,)Q

(B-15)

(e,-10)

The first term on the right side of equation B-16 is die enthalpy .associated with ~hEN T , and ~r , in the second term in equation B- 16, is the effective fraction of ~c. assumed to be radiated isotroplcaily from the fire's combustion zone.

It is ,x~sumed fllat die smoke layer is relatively transparent and that it does no t participate in any significant.radiation heat transfer exchanges. In particular, ,-all of the g r Q radiation is assumed to be incident on the bounding surfaces of the compartment . Therefore, the last term of equation B-I 6 is die ne t amount of enthMpy added to die upper layer from die combustion zone and its buoyancy- driven plume. Flaming fires exhibit values for ~.r of 0 < g r < 0.6 (e.g., smaller values for small methane fires and higher values for large polystyrene fires). However, for a hazardous fire involvinga wide range of common groupings of combustibles, it is reasonable to approximate flame radiation by choosing g r ~ 0.37 [7].

A specific phime ent ra inment model is necessary to complete equations B-14 and 13-15 for the ~hpLtt~clv and qpLlrMl;'. The following estimate for ~hEN T [8 anH'9"ITi's adopted'ff.q'ft-llows:

LF/_AM_ E / DF/RE =

• 0. 2+g[(,- ,,)Q]~/5 / ~ a ~ _,.02 ~ o;

o.249[(1-~,r)Q]2/5 / DHR E -1 .02

if 0.249[(1- ~.r )Q] 215 1 D FIRE - 1.02 _> O;

(Qin kW, ~ in m)

(13-18)

= 0 . 0 0 5 4 / 0 . 0 7 1 - ( 0 . 1 6 6 ) 5 /3 = 0.02591682001.. = 0.026 (!?,-19)

In equations B-17 through B-19, LFLAM E is the fire's flame ng~l, DF/RE is the effective d i a m e t ~ of the fire source

D~TRE / 4 = area of the fire source I, and a is chosen so that, ytically, the value of ~hEN T is exadtly continuous at the

elevation y = YF/RE +LFLAME •

B-4.3 Flow to the Layer from Below the Curtains. f f t he upper layer interface, y, drops below the elevation of the bottom of th-e- curtains, YetrRT, mass and enthalpyflows occur from the upper layer of tlle"~iffained a reawhere the fire is located to adjacent curtained areas of the overall building compartment . The mass flow rate is the result o f hydrostatic cross-curtain pressure differentials. Provided adjacent curtained areas are no t yet filled with smoke, this pressure difference increases linearly from zero at the layer interface to APcuR T aty = YCURT"

From hydrostatics:

(8-20)

Using equation B-20 together with well-known vent flow relations (e.g., equation 32 of reference [4]) mCURT and the qCURT can be estimated from the following:

m ~ n l =

0 if Y-YFIRE <- 0;

if o <(y-yFS ~ ) / L ~ <1,

o.o,,b_;<,)Ql'"-'

(8q7)

60fi

N F P A 204M - - A97 R O P

mCURT

0 if y > YCURT ;

]1/2

if y <- YCURT B-21)

qCURT = ~hCURT C p T u C~-2~)

where LCURT, is that length of the pe r imete r of the curtained area of fire on~m that is connected to other curtained areas of the overall building comparunenL For example, if the curtained area is in one corner of the building compartment , then the length of its two sides coincident with the walls of the compar tment are not included in Lcrmy. Since the generic vent flow configuration under consider- au%n ' h this ~ase is long and narrow, a flow coefficient for the vent flow incorporated into equation B-21 is token to be 1.

B-4.4 Heat Transfer to the Upper Layer. As discussed in B-4.3, where the fire is below d~e layer interface, the buoyant fire plume rises toward the ceiling and all o f its mass and enthalpy flow, thor rrM~ and ~ or rr~*~", is assumed to be deposited into the upper la)teE~lq~ving pede'~ua~ie"~d tl~e interface, the plume continues to rise toward the ceiling of the curtained compartment . As it impinges on the ceiling surface, the plume flow turns and forms a relatively high temperature, high velocity, turbulent ceiling je t that flows radially outward along the ceiling and transfers heat to the relatively cool ceiling surface. The ceiling je t is cooled by convection, and the ceiling material is heated by conduction. The convective heat transfer rate is a strong t rac t ion of the radial distance from the point of plume/cei l ing impingement , reducing rapidly with increasing radius. It is dependen t also on the characteristics of the plume immediately u pstream of ceiling impingement .

The ceiling je t is blocked eventually by tl~e curtains or wall surfaces, or both. It then rams downward and forms vertical surface flows. In the case of wall surfaces and very deep curtains, the descent of these flows is s topped eventually by t ,p~wd buoyant forces and they finally mix with the upper layer. In this case it is assumed that the p l u m e / ceiling impingement point is relatively far from the closest curtain or wall surface (e.g., greater than a few fire-to-ceiling lengths). Under such circumstances the ceilingjet-~r, dl flow interactions are relatively weak and, compared to the net rate of heat transfer from the ceiling and near the plume/cei l ing impingement point, the heat transfer to the upper layer from all vertical surfaces is relatively small.

The symbol ~'CoNV is defined ,'is the fraction of Q , which is transferred by ctnve- c t ion from the upper layer gas ceiling je t to the ceiling and wall/curtain surfaces as follows:

qHT =-xcoNvQ (~-~s) Once the vahnes of )l.t,t~o~0 and q r r r are de te rmined from a

t ime-dependent soluti6" ~'~'tli~e c o u p l ~ , ceiling je t /ce i l ing material, convecnon/condnc t ion problem, the hxsk of determining an estimate for each componen t of rh U and q u is complete.

B-4.4.1 Propert ies of the Plume in the Upper Layer Where Y FIRE < Y" Times when the elevation of the fire is below the interlace (i.e., when YF/RE < -~ ) shoukt be considered.

As the plume flow moves to the center of the upper layer, the forces of buoyancy that act to drive the plume toward the ceiling (i.e., as a result of relatively Ifigh-temperata~re, low-density plume gases being submerged in a relatively cool, higb-density ambient environment) are reduced immediately bec~anse of the temperature increase of the upper layer environment over that of the lower ambient. As a resuk, the cont inued ascent of the plume gases is less vigorous (i.e., ascent is at reduced velocity) and of higher tempera- rare dmn it would be in the absence of the layer• Indeed, some of fl~e penetrat ing phnne flow will be at a lower temperature titan T U . The upper layer buoyant forces on this latter portion of the flow - actually retard and ~-'m possibly stop its subsequent rise to the ceiling•

The s implepo in t source plume model [ 10] is used to simulate the plume flow, first immediately below or upstream of the interface, and fl~en throughout the depth of the upper layer itself.

607

The plume above a po in t source of buoyancy [ 10], where the source is below the interface, is equivalent to the plume of the fire (in the sense of having identical mass and enthalp.y flow rates at the interface) if die point source strength is (1-)~r }Q and the elevation of the equivalent source, YEQ , satisfies the foll6wing:

0 ^1 1/2( )5/2 .~*U3 ,hpLuM E = .z PAMBg [Y-YEQ ) ~EQ (13-24)

In equation 13-24, QEO ' a dimensionless measure of the strength of the fire plume at the ~fterface, is def ined as follows:

• - r 1/2" , 5 / 2 ]

It should be noted that, at an arbiu-ary m o m e n t of time in the simulation of a fire scenario, ~hPLUM E in equation B-24 is a known value that is de termined previofisT~7 fkb"m equations B-15 and 13-17.

Using B-24 and B-25 in order to solve for YEQ and QEQ :

YEQ y - l ( 1 " "" ( ' * 1 /2"~2/5

QEQ = o.21(1- z, )Q / ( CI, T AMBmPLUM E ( ~ 2 7 )

As the plume crosses the interface, the fraction, rh , of ~npLtr~., which is still buoyant relative to the upper layer e n w r ~ ' e n t and presumably continues to rise to the ceiling, entraining upper layer gases along the way, is predicted [ 11] to be as follows:

m* = [ 0 ; - 1 < a 5 0

(B-28) where rite dimensionless parameter o is def ined as:

• " 2 / 3 a=[1-ot+CTQEQ ) / (~-1) (B-29)

o~ = T U / TAMB;CT = 9.115 (B-30)

andwhe re Q~'o is the value c o m p u t e d i n equation B-27. The parameters nYUessary, to describe plume flow continuation. . in the upper layer (Le., between 3 and 3 t ~ r r ) are fur ther identified (see [11]) according to a point source ~lfi~e (see [101"). It has been determined that this plume can be modeled as being driven bya nonradiat ing buoyant source of strength, Q ' , located a distance

t

H = YCEIL - YSOURCE > YCEIL - YHRE (B-31)

below the ceiling in a downward-extended upper layer environment of temperature, Trr, and density, Pit" The relevant parameters predicted [ 11 ] arenas follows: v

Q = / (1+ o) B.321

( ) YSOURCE = Y - Y- YEQ a3/5m*2/5 [(I + a}/a]l/5 (B-3S) The fire and the equivalent source in the lower layer and the

continuation source in the upper layer are depicted in Figures 13- 4.4.1 (a) through (c). Times dur ing a fire simhlation when equation B-29 predicts ¢y >> 1 are related to states of the fire envi ronment in whicli the temperature distribution above T A a ~ oft_he plume flow, at the elevation of interface penetration, is p'~'dYcted to be mostly much larger than ( Tr7 - TA-~R ). Under such circumstances, the penetrat ing plume flb'w is s~lli~fery strongly buoyant as it enters the upper layer. The plume continues to rise to the ceiling and to drive ceiling je t convecuve heat transfer at rates that differ only slightly (due to the elevated temperature upper layer environment) f rom the heat transfer rates that could occur in the absence of an upper layer.

N F P A 2 0 4 M ~ A 9 7 R O P

Fire and flames in the lower layer

(a)

Condit ions where equat ion B-29 predicts cr < 0 are related to t imes dur ing a fire scenario when the t empera tu re of the p lume at the elevation o f interface ~enet ra t ion is predicted to be uniformly less than T u . Unde r such c i rounstances , the penetra t ion p lume flow is no t positively (i.e•, upward) buoyant at may point ,as it enters the uppe r layer. Therefore , while all of tltis flow is a s sumed to en ter and mix with the uppe r layer it is predicted dlat none of it rises to

• • ' . , t .

the ceding in a coheren t p lnme (i.e., Q = 0)• For this reason, where to" < 0, the existence of any significant ceiling j e t flow is precluded a long with significant convective hea t tl~,msfer to rite ceiling surface or to near-ceiling-deployed fllsible links.

The above analysis ;~ssumes that y ~ < ~. However at the onset o f t h e f i r e s c e n a r l o , YmR~ <Y=YCFJL andtz , cr, a n d m of equat ions B-28 throug'l~TL'31, whicl'i t~1"~pend on the inde terminate n tim value of T U are dmmselves undef ined . The si tuation at t = 0

• # I . - t •

Is properly taken into account If 0 = (1 - 3,r)Q and YSOURCE = YEQ at t = 0.

B-4.4.2 General Propert ies o f the P lume in the Upper Layer. Where the fire is below the interface, the results of equat ions B-32 and B-33 allow the fire-driven phmte dynamics in the tipper layer to be described according to the point source phnne m o d e / [ 1 0 ] . If the fire is at or above the interface (i:e., ~ ~-~,~ > ,~) then rhPLUM E = O, qPLUME = (1 - Z r ) Q , a / l ~ i ' ~ point source model is c o n t n m e d in use'fo slmuktte the uppe r layer p lume flow. All cases can be treated ns ing the following final versions of original equations B-32 and B-33 ,as follows:

I *

Q,= 1-~'r)Q ty'h /(I+ty) if YFIRE < Y< Y(2EIL ; (B-34)

I (1- A r)~). i f YF/RE > Y o r if y = YCEIL

if <y < • f FIBE Y FIRE YcEIL '

YSOURCE = I y (Y-YEQ ) 3 / 5 . *2/5 1/5

/ lYEQ if Y = YCE/L

if YF/BE < Y < YCEIL ;

Equivalent plume in the Continuation plume in Me lower layer extended upper layer

(b) (c)

Figure B-4.4.1

B-4.5 Comput ing qlqr T and the Thermal Response o f the Ceiling. Where the fire is beF6& the interface and the interface is below the ceiling, the m e t h o d for calculating tbe bea t transfer from the plume- driven ceiling j e t to the ceiling and the thermal response of the ceiling [12] is used. This m e t h o d was developed to treat generic, conf ined ceiling, room fire scenarios. As oud ined in dais method. [ 12] dae conf ined ceiling problem is solved by applying the unconf ined ceiling hea t transfer solution, [13, 14, 15] to the problem of an upper-layer source in an ex tended upper layer env i ronmen t equivalent to equat ions 13-34 and B-35. Where the fire is above the interface, the unconf ined ceiling methodology applies directly.

To use these me thods [ 1 $ th rough 15] an arbitrary m o m e n t of t ime dur ing die course of the fire deve lopment is considered. It is ,assumed that the tempera ture distribution of the ceiling material, T, has been compu ted up to this m o m e n t and is known as a funct ion of distance, Z, measu red upward f rom the bot tom surface of the ceiling, and radial distance, r, measu red f rom the constant point of plume-ceil ing impingement• The equivalent, ex tended upper-layer, unconf ined ceiling flow and heat transfer p rob lem is depicted in Figure B-4-4.1 (c). It involves the eq_uivalent Q' heat source f rom equat ion B-34 located a distance, /-/ , below the ceiling surface in an ex tended ambien t env i ronmen t of density, Ptl, and absolute temperature , TII, where H is de t e rmined f rom equat ions B-31 an d B-33.

The objective is to esdmate the ins tan taneous convective heat t ransfer flux f rom the upper-layer gas to the lower ceiling surface,

. . . . . . (r t) and the ne t hea t t ransfer fluxes to the u p p e r and Io~'er sL"v ~" '~ce 'of the ceiling, (lu(r,t) and q"r (r,t), respectively• With dais information, the t ime-depe/~dent soluu%h for the in-depth thermal response of the ceiling material can be advanced to subsequen t times. Also, qr ' t~-b, r can be integrated over the lower ceiling surface to obtain dVe"d~iF6d ins tan taneous value for qHT"

In view of the assumpt ions of the relatively large distance of the fire f rom walls or curtains and on the relatively small contr ibut ion of hea t transfer to these vertical surfaces, it is reasonable to carry out a somewhat simplified calculation for q m r - Therefore , qHT is approximated by the integral of q t ~ c l ~ i t over an effective circular ceiling area, AEF F , with a diamet~'(, ~ 10F~ F , centered at the point of impingement•

where m , ~, and 0t are calculated f rom equat ions 13-26 t h rough B-30•

(B-35)

m = A , , 4CONV X (,,@a,

(B-z6)

2 The value Awm ¢ = ffDT~m~ / 4 is taken to be the actual area of

the curtained~[Sii(:e, A , p ~ ~ ) h e por t ion of the vertical curtain an d wall surfaces est imated to be covered by ceiling jet-driven wall flows. An est imate for this extended, effective ceiling surface area is obta ined [16] where it is conc luded with some generality that ceiling jet-driven wall flows penet ra te for a dis tance o f approxlmately 0 . 8 H f rom the ceiling in a downward direction. Therefore:

608

N F P A 2 0 4 M - - A 9 7 R O P

2 AEF F = ;,rDEF F / 4

wbere P is tile total lengfll of the perimeter of the curtained area.

B-4.5.1 Net Heat Transfer Flux to the Ceiling's Lower Surface. The net heat transfer flux to flae ceiling's lower surface, qL, is made by means of up to tilree components: incident radia t ion-4 ~,4 n m-mr ; convection, qCONV,L ; and reradiation, q~dT, RAD,L ,as f'61l~s-." . . . .

(B-37)

As discussed in B-4.4, tile radiant energy from the fire, ;I, rQ, is assumed to be radiated isotropically fi'om the fire widl negligible r:adiation absorption al3d emission fi'om the compar tment gases.

= (e~39)

Tile convective heat transfer flux from the upper-layer gas to die ceiling's lower surface can be calculated [ 13,14] as follows:

q'(JONV,L = hL(T AD - Ts,L ) (8-40)

where Ts_ L is file absolute temperature of tile ceiling's lower surface, TAn , a characteristic gas temperature, is the temperature that is measu- red adjacent to an adiabatic lower ceiling surface, and hL, is a heat transfer coefficient. Equations 41 and 42 determine h L and TAD ,as follows:

h L/i= 0.3 9/3 1/9

0.283Re H - P r - " " (r / H)- "(r / H-O.O771)/(r / H +0.279) if O.2 < r / H (8-40

(T AD-Tu ) / (Tu QH: "2 /3 "~)= lO.22-(14.gr / H) if O< r / H <0.2;

8.39f(r/ H) if 0.2 <_r/ H (B-42)

where:

(B-43)

/~ _ 1 / 2 . 1 /2 ( )*1 /3 1/2 . . 3 / 2 . ; * 1 / 3 . =put, pg 1-1 ~LH ; Re H =g ta ~-H / VU;

"* "/[ (gH)I/2 H21 QH = Q PuCpTu

In tlae equation B-41, P r is tile Prandtl number (taken to be 0.7), in equation B.44, and, vtz is die kinematic viscosity of tile u p p e r . layer gas, which is assume~d to have the properties of air. Also, QH, a dimensionless number, is a measnre of the strengtii of the plume and Re. H is a characteristic Reynolds number of tile plume at tile elevatioh" of tile ceiling.

(B-44)

609

NFPA 204M - - A97 ROP

Tile lollowing estimate for V U [ 17] is used where comput ing Re H from equation B-44

Equations B-40 through B-45 use a w..due for Ttt. At t = 0, where - - .q - - 1 it is undefined, T U . hot Id be set equal to TAM B . This yields the

correct limiting result for the convective heat transfer to tile ceiling; specifically, convective heat transfer to the ceiling from an uncon- fined ceiling je t in an ambient environment.

As the fire simulation proceeds, die ceiling's lower surface tempe~tture, T¢ t , initially at TAMI~, begins to increase. At all times, die lower ceding , urface is ,lssume ! to radiate diffusely to the initially ambient tempe~.-ature floor surface and to exposed surfaces of the building contents. In response to this radiation, and to the direct radiation from d~e fire's combustion zone, the temperature of these surfaces also increase with time. However, for specific times, it is assnmed fllat tile effective temperature increase of these f loor / contents surfaces is relatively small compared to the chm-acteristic increases of T~ ~. Accordingly, at a given radial position of the ceiling's Iower'~h~i'face, the net radiation exchange between the . ceiling and tile f loor /contents sud'aces can be approximated by the following:

where cY is d~e Stefan-Boltzmann constant and E/. and E b'?ooR are . . . . . . . . . . . . n the effectwe emi t tance/ahsolp tance o[ tile ceding upper suff;/ce a d

f loor /contents surfaces (assumed to he grey), respectively, both of which are taken to be 1.

B-4.5.2 Net Heat Transfer Flux to Ceiling's Upper Surface. It is assumed dlat the ceiling's upper surface is exposed to a relatively constant-temperature far-field environment at TAM B . Therefore, the net heat transfer flux to,,this SUl-face, qrr, is matte u}~ of two components , convection, {ICONV, U , and r'e'radiadon, qRERAD,U as follows:

qu = qCTONV LI + qRE[L4DLS (B-47)

These can be estimated from the foUowing:

(B-48)

" 4 4 -1) qRADIJ =°(TAMB-Ts, u)/(I /~u +I/~FAR (B-49)

where.. TsjM. is. the absolute temperature. . of the upper surface of tile ceding, hi" J Is a heat transfer coefficient, and EFAI: t and el l are the effecuve emi t t ance / a~o rp t ance of the far-fi~]~l and ceiling upper surface (assumed to be grey), respectively, both of which are taken to be 1.

Tile value tbr h U to he used [ 18] is ~Ls ffdlows:

h U = I. 65( TAMB - TS,U )1/3 (e,-5o)

(h U in W / m 2 , T A M B arid TS] ] in K )

B-4.5.'~ Solving for the Thermal Response of the Ceiling for qHT." The temperatnre of tile ceiling material is assumed to be governe~l by the Fourier heat conduction equation. By way of the lower ceiling surface boundary condition, tile boundary value problem is coupled to, and is to be solved together with, the system of equations B-2 and B-8.

Initially the ceiling is taken to be of uniform temperature, Tamb. The upper and lower ceiling surfaces are the.n expos.~,d to the radial- and t ime-dependent rates of heat transfer, qfl and qL, determined from equations B-47 ,and ..B-48, resl~,ectively. For specific times in dais case, radial gradients of qv and qL are assumed to be small enough so that conduction in die c.eiling is-quasi-one-dimensional in space [i.e., T = T(Z,t;r)]. Therefore, file two-dimensional thermal response for die i:eiling can be obtained from the solution to a set of one-dimensional conduction problems for

( ' ) ( ' ' )' . . ~ O ' T n Z t = T Z t ' r = r n n = l t o N where N i s the number of thscrete radial posmons necessary to obR~n a suftic=entiy smooth representat ion of the overall ceiling temperature distribu- tion. The r n radial positions are depicted in Figure B-4-5.3.

rNRAD = DEFF/2

r n ~

/

• o o • n

qRERAD, U qCONV, U Eq. (46) Eq. (45)

, qRERAD, L Eq. (36) qRAD--FIRE Eq. (43)

Eq. (37)

F'gure B-4.5.3 Illustration of the geometry_for boundary value problems of the temperature distributions, T n, through the ceiling

at radial positions r n .

T~fa r¢ is assumed to be the maximum temperature of the ceiling ( i . d . ' , ~ temperature of the exposed surface at r = 0) . The parametric study [15] for the thermal response of uncont ined ceilings above constant and growing fires indicates generally that clhanges in TJTA,fa v as a function of r / H are such dlat d(T /TMA ~¢ I /d ' (~ '~H) = 0(1). Therefore, it is rez~hsonable to expect ac'curate r e s - - - h l ' t s for - e equation P~-36 integral of q(z.oArtt l by interpolating between values of qCONV.L calculate-clat'" "r'a-dial positions separated by r / H inter~-Ms of-0.1 to 0.2.

Using the above ideas, the following procedure for f inding the thermal response of the ceiling and solving for qHT is imple- mented:

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N F P A 2 0 4 M ~ A97 R O P

(a) Since 7t~#rr - Y r r R p is a measure of H in the cur ren t problem, a n d " D ~ r F / 'Z~g a measllre of the 0nagimum value of g , N RAn is chosen as several t imes ( D v ~ / 2) / {Y¢811. - YFIRE 1" In i l ' ~ c~e, N DA r/ is ~:hosen as tl~e fi"l~t in~eger '~qu~ to or greffter than [5 [Dm~ 7 ~ ) / /Yc r sL - Yvrnr ) + 21"

(b) One tempera ture malculation point is placed at r = 0 and the remaining Np.AD ~alculation points are distr ibute~ with uniform separation at , ~ l between r = 0 . 2 [ y r # n - y~m# ) and r = DEby. / 2 , the latter value bein'~g'tT~uppe" F~i'n~' 'it of~the integral of equation B-36 [i.e., r 1 = 0; ro =0.2[~r,~rr -~t'ru~ ] ; r~ro~n = DEFF / 2 ; r . =r. +tAr if ~ ' ~ ' ~ < N R A ~ , t w h e r e

- n

(c) The boundary value problems .are solved for the NrtAn . . . . t empera ture distributions,. Tn" At arbitrary, radius, r n , dfe"g'e are indicated m the reset por tmn of Figure 13-4.5.3.

(d) For any m o m e n t of t ime dur ing the calculation, the lower surface values of the Z are used to compute the corresoondinl~ discrete values of q . . . . . . . (t~ = a . . . . . . . (r = r n t'~ from eouauon 8 " 4 0 . ( . A . / l V V , / ~ , ~ I * ¢ . . { ] I Y V , L X ' / *

(e) The ~ t ~ / . distr ibution in r is approximated by interpolat- ing linearly 15~'6b~e"fi the q~'ONV,L,n" The integrat ion i n d i ~ t e d i n equation 13-36 is carried dUE

The procedure for solving for the T is the same as that used in reference [ 15]. It requires the dnckness, thermal conductivity and thermal diffi~sivity of the ceiling material. The solution to the one- dimensional heat conduct ion equat ion involves ,an explicit finite difference scheme that uses an algori thm token from references [19,20]. For a given set of calcnlations, N < 20 equal-spaced nodes are posit ioned at the surfaces and through the flfickness of the ceiling at every radius position r T h e s p a c i n g tSZ (setFigure

• ' " n ' ' B-4.5.3), of these ts selected to be large enough (Ixtsed on a maximum time step) to ensure stability of the calculation.

11-5 Actuation of Vents and Sprinklers by Near-Ceiling-Deployed Fusible Links. It is an objective of this guide to simulate condit ions in building spaces where ceiling vents and sprinkler links can be actuated by the responses of near-ceiling-deployed fusible links. The concept is that, dur ing the course of a compar tmen t fire, a deployed link is engulfed by the near-ceiling convective flow of the elevated- tempera ture products of combust ion and ent ra ined air of the fire- genera ted plume. As the fire continues, convective heat ing of the l ink leads to an increase in its temperature. If and when its fuse tempera ture is reached, the device(s) being operated by the link is actuated.

The near-ceiling flow engulfing the link is the plume-driven ceiling j e t referred to previously, which transfers the flow to the lower ceiling surface and is cooled as it traverses unde r the ceiling from the point of plume-ceiling impingement . In the case of relatively smooth ceiling configurations, , '~sumed to be representative of the facilities studied in this guide, the ceiling j e t flows outward radi,'dly f rom this point of impingement , and its g~s velocity and temperature distributions, Vet and Tc/, r~pectively, are a t r ac t ion of radius from d~e imping-~ment po'fi-~t, r , distance below the ceiling, z, and time.

B-5.1 Predict ing the Thermal Response of the Fusible Links. The thermal response of deployed fusible links is ~'tlculated up to their fi~se temperature , T F , by the convective heat ing flow model [21]. It

is assumed that the specific link is posi t ioned at a specified radius f rom the impingement point, r = r l , and the distance below the lower ceiling surface, z = z l . T I h-as been def ined as the link's assumed near-uniform tem~eratu-re. Therefore, ins tantaneous changes in T L are de te rmined by the following:

/ d t = ( T c J , L - k , TL ))Vc; "L1/2 / RTI (B-51) dT L

where TCTL and V67.. L are the walues of Vcl and TCl, respec- tively, eva~'~ted near-~,.fie link position, and wISere RTI (response t ime index), a property of the link and relative flow orientat ion, can be measured in the "plunge test" [21,22]. The l~T,l.for ordinary sprinkler links range f rom low values of 22( re . s )1 /z for quick- operat ing residenuVal sprinklers, to 375 (re.s) 1 /2 for slower s tandard sprinklers [23]. The utility of equat ion B-51, is shown to be valid typically th rough the link fusing process [24], is discussed fur ther [25], and actually is used to predict link response in a parametr ic study involving two-layer compar tmen t fire scenarios. Also, the link response predict ion methodology has been used [23], and demon- strates favorable comparisons between predicted and measured link responses in a full-scale, one-room, open-doorway compar tmen t fire experiment .

To compute T I f rom equat ion B-51 for a different link location necessitates estim-ates of VCj ,L and TCj,L for arbitrary link positions, r L and z L.

11-5.2 The Velocity Distribution of the Ceiling Jet. Outside of the p lume/ce i l ing impingement stagnation zone, def ined approximately by r / H > 0.-'2, find at a given r~, VCI rises rapidly frohazero at the ceiling's lower surface, z = 0, to a mff.Jdmum, VA~A v , at a distance z = 0 . 2 3 ~ , c$(r) being the distance below the ~ l~mg where V / VMA X" = 1 ' /2116] . In this region outside the s tagnation zone, VC] Ci~tie estimated [16] as shown below:

V cJ I V MAx

Vz I

~ \ \ \ N N N NN NNNN.'qL\. . . \~ (

4 . 3

Z / (0.2303

0

f,,xxx\\xxx\ , ,; )

F'~gu_ re B-5.2 A plot of dimensionless ceilin~ let velocity distribution, vcj / v~ t~x , as a function of • / (0.2~'~) per equaeon B-52.

where r~ H > 0.2:(B-52)

I / 7

(B-52)

V M A x / V 0 .85(r / -H)-L1;6/ H O IO'r "H'O'9 v 1/2H1/2~,*1/3 = = " ~ / ) ; = g ~ H (B-53 )

where QH is defined in equat ion B-44. VC] / VMA X per equat ion B-52 is p lot ted in Figure 17-5-2.

611

N F P A 2 0 4 M I A97 R O P

In the vicinity of near-ceiling-detlloyed links located inside die stagnation zorie, the fire-driven flow is changing directions from an upward-directed plume flow to a outward-directed ceiling jet-type flow. There the flow velocity local to the link, the velocity that drives the link's connective heat transfer, involves generally a significant vertical as well as radial componen t of velocity. Nevertheless, at such link locations, it is reasonable to continue to approximate die link response using equatioti 13-51 with Vf: I estimated using equations B- 52 and B-53 and with r / H set equa[Vto 0.2. This approximation is shown as follows:

Where O<_r/H <0.2:

V C j = V c j ( r l H = 0.2) (B-54)

B-5.3 The Temperature Distribution of the CeillngJet. Outside of the plume-ceiling impingement stagnation zone (i.e., where r / H _> 0.2 ) and at a given value of r , T m rises very rapidly from the temperature of the ceiling's lower sur~t~e, T s I . , at z = 0, to a maximum, T^,A¢, somewhat below the ceiling su'fface. It is assumed that t ~itl~maximum vahie of TCI occurs at the identical distance below the ceiling ,xs does the m.'fximum of Vc. I (i.e., at z = 0 . 2 3 6 ). Below this elevation, T~; I drops with inc'i%asing distance from the ceiling until it reac[i'~s the upper-layer tempera- ture. T U . In dlis latter, outer r e , on of the ~eiljngjet, die sb~.pe o f tile norf~lalized T,, distribution, i Tc: I - T I ] I / ( T M A X - T u }.has tile same characteristio,~ as that ofkV'~.!r / V ~ x , . A]s(), sitice tl rbl lent boundary flow exists, it is r'~ason,'il~'to expect that the characteristic thicknesses of the outer region of both the velocity and temperature distributions is tile same, dictated by the distribu- tion of the turbulent eddies.

ATc j = T c j - T u

= Ceiling jet temperature-upper layer temperature

0

~ N ' x \ \ \ b \ \ \ \ \ \ \ \ \ \ \ " N\ (

'

Figure B-5-3 Plots Of dimensionless ceiling jet temperature distribution, O , as a function of z / 0 . 2 3 3 per equation B-55 for

cases where O s is < O, between 0 and I, and > O.

For these re,xsons the velocity and temperature distribution are approxinlated as in be identical in the oilier region of tile ceiling je t flow, 0 . 2 3 6 < z . In the irmer region of the flow, between z = 0 ar id 0 . 2 3 6 , the normalized telnperaqire distribution is

approximated by a quadratic fimctioil of z / ( 0 . 2 3 ~ ) , necessitating the use of Tg7 = T v t at z = 0 and TCI = T M ~ ~ , dTi)~ldz = 0 a t z = 0 . 2 3 S . Therefore, where r "fl H > "07 ~Z :

In a manner similar to die treatment of V,-, I / VMa x,, for die purpose of calculating T L from equation BY-'eal, OS~]'~ approximated inside die stagnation zone by die description of equations B-55 and B-56, with r / ' H set equal to 0.2 as follows:

<->s ?'<j-T,);(TMA><-T,)= i'0-<'/0.''/' ':

V~71VMA x i f 1 _<,</(0.23<~)

(B-55)

It should be noted that 0 s is negative when the ceiling surface temperature is less dlan tbe-upper-layer temperature (for example, relatively early in a fire, when the original ambient- temperature ceiling surface h:~x not yet reached the aver:,ge temperature of the growing upper layer). Also, (-)~/ is greater than 1 wben die ceiling surface temperature is greater ihan TMA x, . This is possible, for example, during times of reduced fire s[z~ when the fire's near- ceiling plume temperature is reduced significaudy, perhaps temporarily, from previous values, but the ceiling surface, heated previously to relatively high temperatures, has not cooled substan- tially. Plots of (7) per equation B-55 are shown in Fignre B-5-3 for cases where 6) is < 0. between 0 and 1, and > 0.

Where O < r / H <-0.2:

0 S = O S ( r / H = 0 . 2 ) (13-57)

With the radial distribution for T~ t and TH already calculated up to a specific time, only TMA X i~'h~eeded t ffcomplete the equations B-55 through B-57-(s~i'mate for the ceiling je t temperature distribution. This is obtained by invoking conservatibn of efiergy. Therefore, at an arbitrary r outside the stagnation zone, die total rate of radial outflow of enthalpy (relative to the upper-layer temperature) of the ceiling je t is equal to the uniform ra, t$ of enthalpy flow in the upper-layer portion of the plume, Q , less the integral (from the plume-ceiling impingement prior to r ) of the flux of convective heat transfer from the ceiling je t to the ceiling surface as follows:

612

N F P A 2 0 4 M I A 9 7 R O P

Vdlere 0 9 < r . . _ / H :

' . . " r .

~cONV ts the fractmn of Q transferred by convecuon to the ce~Frig from the point of ceiling impingement to r ,as follows:

In equations B-a8 and B-59, Q has been ~dculatedpreviously m equation B-34. Also, the integral on tbe right hand sides of equations B-58 and 13-59 can be calculated by approximating (I . . . . . . . ~[r , l ) ,as shown in equation 13-59 as a linear fimction of r between prevmusly calculated values of qCONV,L (r = rn,t ) .

The integral on the [eft band side of equation B-58 is calculated using Vcr of equations B-52 and B-53 and T m of equations B-55 and B-SlY.:' From this, tile desired distribution'fbr TMA X is de termined `as follows:

.The curtain boards should be deep enough to satisfy - > 0 2 - unless the e uations and (YC~IL, YGURT)- ." (Y, CEJL Y'FIRE..)', .,. q . ,

tJle cocte are usec~ to stmutate an unconl lnea ceaalng scenario wnere [YCEIL - YGURT ) = O.

The ceiling of die curtained space should be relatively smooth, with protuberances° having depths, significandy less than.. 0 .1W . Except at die Iocauons of die curtain boards, below-celhng-mounted barriers to fow, such as solid beams, should be avoided. Ceiling surface protuberances near to and upstream of fusible links (i.e., between the links and die fire) should be significantly smaller than link-to-ceiling distances.

W V is die width, i.e., the smaller dimension of a single ceiling vent (or vent cluster). Therefore, the prediction of smoke layer tlhickness' ~CEJ./,, - ,Y' is reliable only after the time that ~Y'CEIL -- Yl / IWV ts greater than 1. (See also 3-4(a).) Note that diis pFaces fin additiopal limitation on.the minimum depth of the curtain boards [i.e., [YCEIL - YCURT ) / W V sbould exceed I I.

At all times during a simulated fire scenario, the overall building space should be vented to the outside (e.g., through opened doorways).

( T M A x _ T u ) = 2 . 6 ( I _ 2 ' C O N V "~ 0£ , 2 / 3

i f O / 2 < _ r / H

The result of equation [',-60, together with equations B-55 and B-56 r e p r ~ e n t the desired estimate for Te~. Tiffs and the equations B-52 through B-54 estimate for TGj are us'~d to calculate T L from equation I?-51.

B-5.4 Dependence of Open Vent Area on Fusible-Link-Actuated Vents. As discu~ed, the influence of ceiling vent action on the fire- generated environment is dependen t on the active area of the open ceiling vents, A V . A variety of basic vent open ing design strategies is possible, and a major application of the current model equations is to evahmte these strategies within tile context of die developing fire environment. For example, one of the simplest strategies [9], assumes that all vents deployed in die specified curtained area are opened by whatever means at the onset of die fire. In general, A V will be t ime-dependent . To tile extent that a strategy of vent opening is dependen t directly on die fusing of any one or several deployed fusible links, tile Io~ation of these links ~md their charac- teristics (i.e., likely spacings from plume-ceiling impingement , distance below the ceiling, and the RTI) and tile fimctional relationship between link fiasing and A v need to be specified. These matters c~'m be examined in the context of different solutions to the overall problem by exercising parametrically die LAVENT computer program [2], wltich implements all the model equations provided in tl'ds appendix.

B-5.5 Concluding Remarks - - A Summary of Guidelines, Assump- tions, and Limitations. The theory presented here is the basis of

• LAVENT, a user-friendly computer program [2] that is supported by a user guide [3] and dlat can be used to study parametrically a wide range of relevant fire scenarios.

The assumptions made in the development of tile set of model equations provided limit fire scenarios or ~spects of fire scenarios that can h e simulated and studied with confidence. A summary of guidelines and assumptions that characterize what are perhaps file most critic~al of these limitations follows. These are the result of explicit or implicit ~L~mnptions necessary for valid application of the variety of submodels introduced throughout this work.

L and W are tile length and widdL respectively, of the plan area of " the curtained space. Simulated configurations should be limited to those with ~ p e c t ratios, L ~ W that are not much different dlan 1

(B-60)

In dais regard, compared to die open ceiling vents in the curtained compartment , the area of the outside vents must be large enough so that the pressure drop across the outside vents is small compared to die pressure drop across the ceiling vents. For example, under near- steady-state conditions, when the rate of mass flow into the outside vents is approximately equal to the rate of mass outflow from the cteiling vents, ~ outside vent agea must satisfy IAVOUT / A V } ( T u J TAMB) z >>, 1 , or, more conservatively and ihdependen t ot" Tu, AVO / A 2 >> 1 . The latter criteria will always be reasonablytatisfieU~if ,~V)ou T / A v > 2 . Under flashover- level conditions, s3y , when T u/T,,djMB = 3, the former criterion will be satisfied if [ 3 A v o u T / A V ~ >> i , say, if AVOUT = AV , or even AVOUT is somewhat smaller than Av.

The simulation assumes a relatively quiescent outside environment (i.e., without any wind) and a relatively quiescent inside environ- ment (i.e., remote from vent flows, under-curtain flows, ceiling jets, and the fire plume). In real fire scenarios, such an assumption sbould be valid where the characteristic velocities of actualflows in these quiescent environments are much less than the velocity of the fire plume near its ceiling impingement point (i.e., where the characteristic velocities are much less than VMA X of equation 13- 53). It should be noted that, for a given fire strength, Q , this latter a(ySUmption places a restriction on die maximum size of

CEIL - YbTRE)' which is a m~asure of H , sir~cel/~3MA X is appro~imafeTy--proportional to [YCE/L - YF/RE)- ' ~"

In configurations where smoke flows below curtain partitions to adjacent curtained spaces, the simulation is only valid up to the time that it rakes for any one of the adjacent spaces to fill with smoke to the level of the bottom of die curtain. While it is beyond the scope of diis guide to provide any general guidelines for this limiting time, die following rule can be useful where all curtained spaces of a building are similar and where die fire is not growing too rapidly die time to fill an adjacent space is of the order of the time to fill the original space.

The reliability of the simulation begins to degrade subsequent to die time dlat file top of the flame penetrates die layer elevation and especially if equation B-20 predicts a flame height that reaches the ceiling.

It is assumed that the smoke is relatively t ransparent and that the rate of radiation absorbed by or emitted from the smoke layer is small compared to file rate of radiat ion transfer f rom the fire's combustion zone. The assumption is typically true and a simulation is valid at least up to those times that the physical features of the ceiling can be discerned visually from the floor elevation.

613

N F P A 2 0 4 M ~ A 9 7 R O P

It should be emphasized that the above limitations are intended only as guidelines. Therefore, even when the characteristics of a particular fire scenario satisfy tilese limitations, die results should be regarded with caution until solutions to the overall model equations have been validated by a substantial hody of experimental dat.x Also, where a fire scenario does not satisfy die above limitations but is close to doing so, it is possible that the model equations can still provide usefifl quantitative descriptions of the simulated phenom- ella.

B-6 Referenc~ for Appendix B.

1. Cooper, L.Y., "Estimating the Environment and the Response of Sprinkler Links in Compartment Fires with Draft Curtains and Fusible Link-Actuated Ceiling Vents," Fire .~fetyJournal, Vol. 16 pp, 137-163, 1990.

2. LAVENT software, available from National Institute of Shandards and Tecbnology, Gaithersburg MD.

3. [)avis., W . D .,and ..('looper : LY. 7 "Estimatin g file Environment a n d . the Response of Sprmkler Links tn Compartment Fires with Dr,fit Curtains and Fusible Link-Actuated Ceiling Vents ~ Part II: User Cuide for the Colnputer Code LAVENT," NISTIR 89-4122, National Institute of StandarcLs and Technology, Caithersburg MD, August 1989.

4. Emmons, H.W., "The Flow of Gztses Through Vents," Harvard University Home Fire Project Technical Report No. 75, March 16, 1987.

5. Thomas, P.H., eta/, "Investigations into the Flow of Hot Gases in Roof Venting," Fire Research Technic~'d Paper No. 7, HMSO, London, 1963.

6. Heskestad, G., "Smoke Movement and V e n t i n . . g," Fire Safety Journal, 11, pp 77-83, 1986, and Appendix A: C, uzde for Smoke and Heat Venting. NFPA 204M, National Fire Protection Association, Quincy, MA, 1982.

7. (looper, L.Y., "A Mathematical Model for Estimating Available Safe Egress Time in Fires, Fire and Materials," 6, 3?'4, pp. 135--144, 1982.

8. Heskestad, G., "Engineering Relations for Fire Plumes," Fire Safe~.Joumal, 7, pp. 25-32, 1984.

9. Hinkley, P.L., "Rates of 'Production' of Hot Gases in Roof Venting Experiments," Fire Safety Journal, 10, pp. 57--64, 1986.

10. Zukoski, E.E., Kuboha, T., and Cetegeu, B., Fire Safety Journal, 3, p 107, 1981.

I 1. (looper, L.Y., "A Buoyant Source in the Lower of Two, Homogeneous, Stably Stratified Layers," 20th International Symposium on Combustion. Comhustion Institute, pp. 1567-1573, 1984.

12. Cooper, LY., "Convective Heat Transfer to Ceilings Above Enclosure Fires," 19lh Symposium (Interttational) on Combustion, Combustion Institute, pp. 933-939 (1982).

13. Cooper, L.Y., "Heat Transfer fi'om a Buoyant Plume to ,an iJnconfined Ceiling," Journal ¢fHazt Transfer, Vol. 104, pp. 446--451, Aug. 1982.

14. Cooper, LY. and Woodhouse, A., "The Buoyant Plume-Drlven Adiatxttic, Ceiling Tern p(erarure Revlsited,"Journal of Heat Transfer, Vol. 108, pp. 822---826, Nov., 1986.

15. Cooper, LY., and Stroup, D.W., "Thennal Response of Unconfined Ceilings Above (;rowing Fires and the Importance of Convective Heat Transfer,"Joumal of Heat Transfer. Vol. 109, pp. 172-178, Feb. 1987.

16. Cooper, LY., "Ceiling Jet-Driven Wall Flows in Compartment Fires," Condmstion .Science and Technolol~, Vol. 62, pp. 285--296, 1988.

17. Hilsenratil,J., "Tables of Thermal Properties of Gases," Circular 564, National Bureau of Standards, Galthersburg, MD, Nov. 1955.

18. Yousef, W.W., Tarasuk,J.D., and McKeen, wJ. , "Free Convec- tion Heat Transfer from IJpward-Facing, Isothermal, Horizontal

Surfaces,"Journa/of Heat Transfer, Vol. 104, pp. 49~-499, Aug. 1982. 19. Emmous, H.W., "The Prediction of Fire in Buildings," 17111

Symposium (International) on Combustion, Combustion Institute, pp. H01-1111 (1979).

20. Mider, H.E., and Emmons, H.W., "Documentation for the Fifth Harvard Computer Fire Code," Home Fire Project Tech. Report 45, Harvard University, Cambridge, MA 1981.

21. Heskestad, G. and Smith, H.F., "Investigation of a New Sprinkler Sensitivity Approval Test: The Plunge Test," Technical Report Serial No. 22485, RC 76-T-50, Factory Mutual Research Corporation, Norwood, MA, 1976.

22. Heskestad, G., "The Sprinkler Response Time Index (RTI)," Paper RC,-81-TP-3 presented at file Technical Conference on Residential Sprinkler Systems, Factory Mutual Research Corpora- tion, Norwood, MA, April 28-29, 1981.

23. Evans, D.D., "Calculating Sprinkler Actuation Times in Compartments," Fire Safety Journal, 9, pp 147-155, 1985.

24. Evans, D.D., "Characterizing the Tbermal Response of Fusible Link Sprinklers," NBSIR 81-2329, National Bureau of Standm'ds, Gaithersburg, MD, 1981.

25. Cooper, L.Y. and Stroup, D.W., "Test Results and Predictions for the Response of Near-Ceiling Sprinkler Links in Full-Scale Compartment Fires," Fire Safa" 3 Science - - Proceedings of th* Second International Symposium, Tokyo, June 13-17, 1988, pp 623-632, T. Wakumatsu et al, Eds., International Association of Fire Safety Science, Hemisphere Publishing Co., New York, 1989.

B-7 Nomenclature for Appendix B.

A = plan area of single curtained space

A E ~ = effective area for heat transfer to the extended lower ceiling surface, f fD~F / 4

A v = total area of open ceiling vents in curtained space

AVOU7/. = total area of open vents to outside exclusive of A v

C = vent flow coeffident (= 0.68)

Cp = specific heat at constant pressure

C T = 9.115, dimensionless constant in plume model

C g = specific heat at constant volume

DEF F = effective diameter of AEF F

= effective diameter of fire source DFIRE ( fiDe/RE / 4 = area 0ffire source )

g = acceleration of gravity

H = distance below ceiling of equivalent source

/~ = characteristic heat transfer coefficient

h L, h U = lower, upper ceiling surface heat transfer coeffi- cient

L = dlaracterisdc length of the plan area of curtained space

LGURT = lengfll of the perimeter of area A connected to other curtained areas of the building

LFLAM E = flame length

7hGURT = mass flow rate from below curtain to upper layer

mENT = rate of plume mass entrainment between the fire and the layer interface

7nPLUME = mass fl0w rate of plume at interface

614

N F P A 2 0 4 M ~ A 9 7 R O P

m U

~h U

~hVENT

N

NRAD

P

P,.

P

Pv , P A ~

Q,

Q n

.,It QEQ

qCONV,L, qCONV,U

q CONV.L,n

qCURT

q PLUME

q RAD- FIRE

• H q t t q RERAD ,L ' RERAI) ,U

qv

• s s • ~ u ,

qL, qv

R

Re. H

RT1 I"

r L

T

TAD

TcJ

To] .L

= total m~ss of the upper layer

= net mass flow rate to upper layer

= mass flow rate through ceiling vents to upper layer

= number of equal-spaced nodes through the ceiling

= number of values of r n

= length of perimeter of single curtained area

Prandtl number, taken to be 0.7

"~ PAMB at floor elevation

pressure in upper layer, outside ambient

= energy release rate of fire

s t r en~h of continuation source in extended upper layer

= dimensionless strengtla of plume at ceiling

= dimensionless strengtll of plume at in te trace

= convective heat transfer fltLX tO lower, upper ceiling surface

= qCONV,L(r=rn,t)

= endmlpy flow rate from below curtain to upper layer

= beat transfer rate to upper layer

• , enthalpy flow rate of plume at interface

= radiation flux incident on lower surface of ceiling

= re-radiation flux to lower, upper surface of ceiling

= net endmlpy flow rate plus heat u,'ansfer rate to upper layer

• , net beat transfer fluxes to upper, lower ceiling surface

= enlbalpy flow rate through ceiling vent to upper layer

gas cooshant , ( ~ - qcp / ~ = cp - c. v

re)a~olds number of plume at ceiling ele~ttion

Response Time Index

.radial distance from plume-ceiling impmgement

r at link

~= discrete values of r

absolute temperature of ceiling material

adiabatic lower ceiling surface temperature

temperature distribution of ceiling je t gas

Tcj at llnk

TMA x (t)

TS,I., TS,U

Ts,L,n(t)

Tu, T A ~

7",, t

v

Vcj

Vq,L

VMAX W

Wv

Y, YC, EIL , Y CURT , Y FIRE

y" SOURCE

Z

• Z, ='L

O~

AP c~L

APCURT

~Z

E

~L' ~U' ~FLOOR' e FAR

6)

Os

2coNy

2coNy

vv

Pv ,P AMB

IT

- ~ , , ( , : 0,,)-- r (z - - 0,, , ,-- 0)

= absolute temperature of lower, upper ceiling surfac e

rs, , T (z = absolute temperature of upper layer, outside ambient

T(Z,t;r= %)

time

average flow velocity through all open Vents

= velocity distribution of ceiling jet gas

Vcj at link

= maximum value of VCj at a given r

= characteristic width of plan area of curtained space

= width of a single ceiling vent (or vent cluster)

= elevation of: smoke layer interface, ceiling, bottom of curtain, fire above floor

= elevation of plume continuation point source in extended upper layer above floor

= distance into the ceiling, measured from bottom surface

= distance below lower ceiling surface, z at link

r u / T a2v~

= ratio of specific heat, Cp / C V

= cross-vent pressure difference

= cross-curtain pressure difference

= valueof z where v c j =VMA X / 2

= distance between nodes through the ceiling thickness

= constant, equation (8-18)

= emittance/absorptance of: lower, upper, floor, and far field grey surfaces, all taken to be 1

= normalized, dimensionless ceiling jet t(eTmperatur $ distribution,

q - ru) / / T ~ x - ru ) = O at lower ceilinu surface,

fTs.L-Tu)/I%x-Tu) = fraction of Q radiated from combus-

tion zone

= fraction of Q transferred by convection from upper layer

• ' p

= fracuon of ~ transferred to the ceiling in a arc le of radius r , and centered at r = 0, equation (B-56).

= kinematic viscosity of upper layer gas

= density of upper layer, outside ambient

dimensionless variable, equation ( B - 2 8 )

615

N F P A 2 0 4 M - - A 9 7 R O P

Appendix C User Guide for the LAVENT Computer Code

This Appendix is not a part of tlw r~omnwndations of this NFPA document but is incbMed fi~r informational pu~pose.~ only.

C-1 Overview. This appendix is a user gatide for tile LAVENT computer code (Link-Actuated VENTs), Version 1.1, and an ,associated graphics code c=dled GRAPH. As discussed in Section 6-2 and Appendix B, LAVENT has been developed to simulate tile environment and the response of sprinkler linLs in compar tment fires ,fith curtain boards and fusible-link-actuated ceiling vents.

A fire scenario simulated by LAVENT is defined by the following inl)ut parameters:

(a) Area and height of tile curtained space;

(b) Floor-to-bottom-of-curtain separation distance;

(c) Length of the curtain (a portion of the perimeter of the curctined space can include floor-to-ceiling w:,dls);

(d) Thickness arid prol)erties of the ceiling material (density, thermal conductivity, and heat capacity);

(e) Constants that define a specified t ime-dependent energy release rate of tile fire;

(f) Fire elewation;

(g) Area or characteristic energy rele:L~e rate per unit area of the fire;

(h) Tohal area of ceiling vents whose openings are actuated by a single filsible link (multiple vent area/ l ink system combinations may be permitted in any particular simulation); and

(i) Identifying numbers of fusible links used to actuate single sprinkler heads or groups of sprinkler heads (multiple sprinkler links are permit ted in any particular simulation).

Tile characteristics of tile simulated fusible links are defined by the following input parameters:

(a) Radial distance of tile link f lom tile f i re/cei l ing impingement point;

(b) Ceiling/link separation distance;

(c) Link fuse temperature; and

(d) The response time index (RTI) of the link.

For any particular run of LAVENT, the code outputs a summary of the input information and simulation results of die calculation, in tabular form, at uniform simulation time intervals requested by the user. The output results include:

(a) Temperature of the upper smoke layer;

(b) Height of the smoke layer interface;

(c) Total mass in the layer;

(d) Fire energy release rate;

(e) Radial distributions of the lower ceiling surface temperature;

(f) Radial distribution of heat transfer rates to the lower and upper ceiling surfaces; and

(g) For each link, the temperature, and the local velocity and temperature of the ceiling jet.

This appendix explains LAVENT using a series of exercises in which the reader reviews and modifies a default input data file that describes vent and sprinkler actuation during fire growth in an array of wood pallets located in a warehouse-type occupancy. Results of tile default simulation are discnssed.

LAVENT is written in FORTRAN 77. The executable code operates on IBM PC-compatible computers and needs a minimum of 300 kilobytes of memory.

C-2 Introduction - - The Phenomena Simulated by LAVENT. Figure C-2 depicts the generic fire scenario simulated by LAVENT. This involves a fire in a building space with ceiling-mounted curtain boards and near-ceiling fusible-link-actuated ceiling vents and sprinklers. The curtained area can be considered as one of several such spaces in a single large building compartment . By specifying that file curtains be deep enough, they can be thought of as simulating file walls of a single uncurta lned compar tment that is well-ventilated near the floor.

"•- Y YFIre i Curt Layer interface j y I-,re---,~]-- ~,~e,i ,~ir

Vent or sprinkler link

'1 Distance

below ceiling

. / - / \veloci~

Figure C-2 Fire in a building space with curtain boards, ceiling vents, and fusible links.

616

NFPA 204M ~ A97 R O P

Tile fire generates a mixture of gaseous and solid-soot combustion products. Because of high temperature, buoyancy forces drive the products upward towarcl tile ceiling, forming a plume of upward moving hot gases and particulates. Cool gases are laterally entrained and mixed wid~ tile phmte flow, reducing its temperature as it continues its ,ascent to the ceiling.

When file hot phnne flow impinges on the ceiling, it spreads under it, forming a relatively thin, high-temperature ceiling,jet. Near- ceiling-deployed fusible lines engulfed by die ceil ingjet are depicted in Figure G-2. There is reciprocal convective cooling ,and heating of the ceiling je t and the cooler lower ceiling surface, respectively. The lower ceiling surface is also heated due to radiative transfer from tile combustion zone and cooled due to reradiadon to tile floor of the compartment. Tile comparm)ent floor is ;tssnmed to be at ambient temperature. The upper ceiling surface is cooled as a result of convection and radiation to a far-field, ambient temperature environment.

V~qaen tile ceiling jet reaches a bounding vertical curtain board or wall surface, its flow is redistribttted across the entire curtained area and begins to form a relatively quiescent smoke layer (now some- what reduced in temperatm'e) that submerges the continuing ceiling-jet flow activity. The vpper smoke layer grows in thickness. Away from bounding surf:tces, the t ime-dependent layer tempera- lure is assumed to be relatively uniform tlaroughout its thickness. It should be noted that the thickness and temperature of tile smoke layer ,affects the npper-phnne characteristics, the ceilingTjet characteristics, and the heat-transfer exchanges to die ceiling.

If tile height of tile bottom of the smoke layer drops to the bot tom of the curtain board and continues downward, rile smoke begins to flow below the curtain into tile adjacent curtained spaces. Tile growth of the upper layer is retarded.

D3

Draft curtain D2

• • • • • • •

L1

• • o.o /

/ Fire /

• • 0 / 3 • • • •

/ Vent

• • / O • • \ • • (~,rin kl;r

D 1 = 12 ft L 1 = 6 R: 2 sprinklers ~ D 2 = 21 ft L 2 = 21.2 It: 2 vents

D 3 = 42 ft L 3 = 44.3 ft: 2 vents L 4 = 13.4 ft: 4 sprinklers

Fusible links that are designed to actuate tile opening of ceiling vents and tile onset of materflnw through sprinklers are deployed at specified distances below fl~e ceiling and at specified radial dist,-mces from the phnne/ce i l ing impingement point• These links are submerged within the relatively high-temperature, high-velocity ceiling-jet flow. Since the velocity and temperature of the ceiling je t varies widl location anti time, tile heat transfer to and time-of-fusing of any particular link design also varies.

Tile fusing of a ceiling-vent link leads to the opening of all vents "ganged" to that link. Once a ceiling vent is open, smoke flows out of the curtained space. Again, :Ls in a case where smoke flows below tile curtains, growth of the upper layer tllickness is retarded.

The fusing of a sprinkler link initiates the flow of water tilrough the sprinkler.

All of these above phenomena , up to the time that waterflow through a sprinkler is initiated, are simulated by LAVENT. Results cannot be used after water begins to flow through a sprinkler.

C-3 The Defauh Simulation. Tile use of LAVENT is discussed and is illustrated in tile following paragraphs where exercises in reviewing and modifying the LAVENT default-simulation input file are provided. To appreciate tile process more fully, a brief description of tile default sitmdation is presented at the outset.

NOTE: As explained in G-4 Getting Sor ted , the user can choose to run LAVENT using either English or metric units. The default simulation uses English units. Tile example in Appendix D uses metric units.

Tile de,~ault scenario involves a 84 ft x 84 ft curtained compar tment (7056 f t~in area) with the ceiling located 50 ft above tile floor. A curtain board 15 ft in depth completely surrounds and defines the compartment , which is one of several such compartments in a larger building space. The ceiling is constructed of a relatively thin sheet- steel lower surface that is well-insulated from above. [SeeFigure C- 3(,,).1

The curtained compar tment has fou~ uniformly spaced, 48 ft 2 ceding vents w~th a total area of 192 ft "~, or 2.7 percent of tile compar tment ;trea. Opening of the ceiling vents~is.actuated by quick-response fusible links witll RTIs of 50 fit.s) J / ~ and fuse temperatures of 165°F. The l i n ~ are located at tile centers of the vents and 0.3 ft below the ceiling surface.

Figure C-3(a) Vent and sprinkler spacing and fire location for the default simulation.

Fusible-link-actuated sprinklers are deployed on a square grid with | ~-~t spacing between sprinklers. The links have RTIs of 400 fit-s) ~/~ and fuse temperatures of 165°F. The sprinklers and links are mounted 1 ft below the ceiling surface.

The simulation fire involves four abutting 5-ft higll stacks of 5-ft x 5- ft wood pallets. Tile combined grouj~ng of pallets makes up a combustible array l0 ft x 10 ft (100 ft ~ in area) on the floor and 5 ft in height• It is assumed that other combustibles in the curtained compar tment are far enough away from this array that they cannot be ignited in the time interval to be simulated.

The total energy release rate of the simulation fire, ~ , is assumed to grow from ignition, at time t = 0, in proport ion to t ~. According to the guidance in Table 4.2 of [ 1 ], in the growth phase of the fire,

is taken specifically as follows:

Q = 1000 i t / (130 s)l 2 Btu/s

The fire grows according to the above estimate until the combus- tibles are fully involved. It is then assumed that Q levels o f f to a relatively constant value. Following the guidance of Table 4.1 of [1] and Table 5-5.2(b), it is estimated that, at the fully developed stage of the fire, the total energy release gate for the 5-ft high stack of wood,pallets will be 330 (Btu/s) / f i~, or 35,000 Btu/s for the entire 100-ft ~ array. The above equation leads to the result that the fully developed stage of the fire will be initiated at tfd = 747 s.

A plot of the fire growth according to the above description is shown in Figure C-3(b). In the actual calculation, the fire's instantaneous energy release rate is estimated by interpolating linearly between a series of N input data points at times t n, n = 1 to N, on the fire-growth curve. These points are def ined by-user- specified values of [tn, 0 (tn) ]" For times larger than tN, the fire's energy release rate is 5.ssfim~d to stay constant at Q (tN)~ The calculation fire-growth curve involves six input dat~ p t in ts (i.e., N = 6). These points are plot ted in Figure C-3(b).

617

N F P A 2 0 4 M - - A 9 7 R O P

40(103) I I I I I I I

30(103 )

.~" 2o0o 3)

lO(lO 3)

OC 0 ! t

200 400 600 800 Time (s)

Figure C-3(b) Energy release rate versus t ime for the fire of the defaul t s imulat ion.

The position of the center of the fire is identified in Figure G-S(a). In terms of th i sp lan view, the fire is a s sumed to be located at the midpo in t o f a 12-ft line between two sprinkler links, at a distance of 21,2 ~t f rom each o f tile two closest equidistant vents (a total a rea o f 96 fig), and at a distance of 44,3 ft f rom the remain ing two ecluidis- t,ant vents (a total area of 96 ftg). Of the sprinklers and assocmted links, two are closest and equidistant to the f ire-plume ,axis at radial distances of 6 ft. Figure C-3(a) shows that the second ,and th i rd closest groups of sprinklers and links are at radial distances o f 13.4 ft (four sprinklers and links) and 18 ft (two sprinklers and links). In the de fauh calculation, the open ing o f each of the four vents occurs, and the flow ou t of the vents is initiated at the s imula ted t ime of fusing o f their associated links, Also s imulated in the defaul t calculation is the thermal res )unse, including time-of-fusing, of the pair of sprink er I nks c osest to the fire.

As a final specification of the fire, it is a s sumed that the characteris- tic elevation of the fire remains at a fixed value, 2.5 ft above the floor, at the initial mid-elevatlon of the array of combustibles.

For tile purpose of the defaul t calculation, the s imulat ion is carried out to t = 400 s, with data ou t pu t every 30 s.

Having described the defanl t s imulat ion, the procedure for gett ing started and us ing LAVENT follows.

C-4 Gett ing Started. The executable code, LAVENT.EXE, is f ound on the f loppydisk. Before us ing it, backup copies should be made. If the user has a hard drive, a separate directory shou ld be created and the executable code should be copied into tha t directory. The code operates on an IBM PC or compatible compute r conta in ing a mafia coprocessor. It is written in Fortran 77 a n d n e e d s a m i n i m u m of 300 kilobytes o f memory.

To execute LAVENT, change to the proper directory or insert a floppy disk conta in ing a copy of the executable code and enter LAVENT [retl. In this case [ret] refers to the ENTER or RETURN key. Tile first p rom p t is:

ENTER 1 FOR ENGLISH UNITS, 2 FOR METRIC UNITS

The program has a urfit conversion funct ion ~md t ransforms files that are in one set of units to ano the r set. The code executes in SI units and so conversion is only done on inpu t and ou tpu t in order to avoid round ing errors.

For the pttrposes of gett ing started, choose Opt ion 1, ENGLISH UNITS. Enter 1 [ret]. T he following m e n u will be displayed on the screen:

I READ AND RUN A DATA FILE 2 READ AND MODIFY A DATA FILE 3 MODIFY THE DEFAULT CASE TO CREATE A NEW FILE 4 RUN THE DEFAULT CASE

618

ff Opt ion 1 or 2 is chosen, the p rogram will ask for the n a m e of the da ta file tha t will be used. If the chosen file resides on the ha rd disk, dais quest ion should be answered by typing the pa th of the file name; for example, C~ksubdirectory~lename. If the file is on a floppy disk, type A:fi lename or B:filename, d e p e n d i n g on whether the A or B drive is being used. It is r e c o m m e n d e d that all data files use a c o m m o n extender such a s , i n order to facilitate identification of these files.

A first-time user should select Opt ion 4, RUN THE DEFAULT CASE, by en te r ing 4 [ret]. This will ensure that the code has been t ransferred intact. The defanh-case ou tpu t is provided in Table C-4. This is discussed in Section C-8. As a point of information, the t imes needed to carry out the defaul t s imulat ion on IBM PC-compatible 486 /33 MHZ and P e n t i u m / 9 0 MHZ computers were 40 s and 8 s, respectively.

Now restart the code and, at dais point, choose Opt ion 3, MODIFY THE DEFAULT CASE, to review and modify the default inpu t dam. Enter 3 [ret].

C-5 The Base Menu.

G5.1 Modifying the Default Case - - General . W h e n Opt ion 3, MODIFY THE DEFAULT CASE, is chosen, the following m e n u is displayed:

1 ROOM PROPERTIES 2 PHYSICAL PROPERTIES 3 O U T P U T PARAMETERS 4 FUSIBLE LINK PROPERTIES 5 FIRE PROPERTIES 6 SOLVER PARAMETERS 0 NO CHANGES

This will be referred to as the "base menu . "

Enter ing the appropriate option n u m b e r o f the base m e n u and then [ret] will always transfer the user to the indicated i tem on the menu . Enter ing a zero will t ransfer the user to the file status port ion of the inpu t section discussed in Section C-6.

The nex t five sections discuss data entry unde r Options I th rough 6 of the base menu .

Now choose Opt ion 1, ROOM PROPERTIES, of the base m e n u to review and modify the default room-proper ty inpu t dam. Enter 1 [ret].

C-5.2 Room Properties. W h e n Opt ion 1, ROOM PROPERTIES, of the base m e n u is chosen, the following room propert ies m e n u is displayed:

1 S0.00000 CEILING H E I G H T (FT) 2 84.00000 ROOM LENGTH (Fr) 3 84.00000 ROOM WIDTH (Fr) 4 2 NUMBER OF VENTS, ETC. 5 336.00000 CURTAIN LENGTH (FT) 6 15.00000 HEIGHT TO BOTTOM OF

CURTAIN (FF) 0 TO CHANGE NOTHING

All inpu t values are expressed in ei ther Scientific In temat iona le or English units, and the units are p romp ted on the inpu t menus .

Note tha t the defaul t n u m b e r of vents is 2 and no t 4, since the symmetry of tile defaul t scenario, as indicated in Figure C-$(a), leads to =ganged" operat ion o f each of two pairs o f the four vents involved.

To change an inpu t value in the above room propert ies m e n u (e.g., to change the ceiling he igh t f rom 30 ft to 20 ft) the user would en ter 1 [ret] and 20. [ret]. The screen would show revisions us ing the new value of 20 ft for the ceiling height. This or o ther values on this screen can be changed by repeat ing the process.

WARNING: THE USER IS WARNED THAT IT IS CRITICAL TO END EACH ENTRY NUMBER WITH A DECIMAL POINT WHEN A NONINTEGER NUMBER IS INDICATED (I.E., WHEN THE SCREEN DISPLAY SHOWS A DECIMAL POINT FOR THAT ENTRY). THE USER IS WARNED F U R T H E R T H A T THE CODE WILL ATTEMPT TO RUN WITH ANY SPECIFIED INPUT FILE AND THAT IT WILL N O T DISTINGUISH BETWEEN REALISTIC AND UNREALISTIC INPUT VALUES.

N F P A 2 0 4 M - - A 9 7 R O P

Table C,-4 (page 1 of 4 pages) The Default-Case Output

CEILING HEIGHT = ROOM LENGTH = ROOM WI DTH = CURTAIN LENGTH = CIIRTAIN HEIGHT = MATERIAL = CEILING CONDUCTIVrI'Y = CEILING DENSITY = CEILING HEAT CAPACITY = CEILING THICKNESS = FIRE HEIGHT = FIRE POWER/AREA =

30.0 FT 84.0 FT 84.0 F r 336.0 FT 15.0 F r INSULATED DECK (SOLID POLYSTYRENE) .240EA)4 BTU/FF F S .655E+02 LB/FT3 .277E+00 BTU/LB F

.500E+00 FT 2.5 FT

0.3300E+03 BTU/S FT2

L I N K N O = 1 RADIUS= 6.0FT DISTCEILING= 1.00FT RTI= 400.00 SQRT FUSION TEMPERATURE FOR LINK = 165.00 K

LINKNO= 2RADIUS= 21.2FT DISTCEILING= 0.30FT RTI= 50.00 SQRT FUSION TEMPERATURE FOR LINK = 165.00 K

LINKNO= 3 RADIUS= 44.3 FT DISTCEILING= 0.30 FT RTI= 50.00 SQRT FUSION TEMPERATURE FORLINK= 165.00 K

VENT = 1 VENT AREA = 96.0 FT2 LINK CONTROLLING VENT = 2 VENT = 2 VENT AREA = 96.0 FT2 LINK CONTROLLING VENT = 3

TIME (S)= 0.000 LYR TEMP (F)= 80.0 LYR HT (FT)= 30.00 LYR MASS (LB)= 0.000E+00 FIRE OUTPUT (BTU/S)= 0.0000E+00 VENTAREA (FT2)= 0.00 LINK= 1 LINKTEMP (F)= 80.00 JET VELOCITY (FT/S)= 0.000JETTEMP (F) = 80.0 LINK = 2 LINK TEMP (F)= 80.00JET VELOCITY (FI ' /S)= 0.000JET TEMP (F) = 80.0 LINK = 3 LINK TEMP (F)= 80.00JET VELOCXI'Y (FF/S)= 0.000JET TEMP (F) = 80.0 R (FT)= 0.00 TSL (F)= 80.0 QB (BTU/Fr2 S)= 0.000E+00 QT (BTU/FT2 S)= 0.000E+00 R (FT)= 12.41 TSL (F)= 80.0 QB R (FT)= 24.82 TSL (F)= 80.0 QB R (FF)= 37.23 TSL (F)= 80.0 QB R (FT)= 49.64 TSL (F)= 80.0 QB R (FT)= 62.05 TSL (F)= 80,0 QB

(BTU/FT2 S)= 0.000E+00 QT (BTU/FT2 S)= 0.000E+00 (BTU/FI '2 S)= 0.000E+00 QT (BTU/FT2 S)= 0.000E+00 (BTU/FT2 S)= 0.000E+00 QT (BTU/FT2 S)= 0.000E+00 (BTU/FT2 S)= 0.000E+00 QT (BTU/FT2 S)= 0.000E+00 (BTU/FT2 S)= 0.000E+00 QT (BTU/FT2 S)= 0.000E+00

TIME (S)= 30.000 LYR TEMP (F)= 89.6 LYR HT (FT)= 28.90 LYR MASS (LB)= 0.562E+03 FIRE OUTPIJT (BTU/S)= 0.1776E+03 VENT AREA (FT2)= 0.00 LINK = 1 LINK TEMP (F)= 80.78JET VELOCrFY ( F r / s ) = 1.866JET TEMP (F) = 94.9 LINK= 2 LINKTEMP (F)= 85.37JETVELOCI'IY (FI ' /S)= 2.077JETTEMP (F) = 95.3 LINK= 3 LINKTEMP (F)= 81.83 JET VELOCKIY (FT/S)= 0.873 JET TEMP (F) = 87.4 R (FT)= 0.00 TSL (F)= R (FT)= 12.41 TSL (F)= R (FT)= 24.82 TSL (F)= R (FT)= :¢7.23 TSL (F)= R (FT)= 49.64TSL (F)= R (FT)= 62.05 TSL (F)=

84.5 QB (BTU/FF2 S)= 0.312E-01 QT (BTU/FT2 S)= 0.847E-18 81.7 QB (BTU/FT2 S)= 0.122E-01 QT (BTU/FF2 S)= 0.847E-18 80.8 QB (BTU/FT2 S)= 0.570E-02 QT (BTU/Fr2 S)= 0.847E-18 80.4 QB (BTU/FT2 S)= 0.325E-02 QT (BTU/FT2 S)= 0.847E-18 80.3 QB (BTU/FT2 S)= 0.212E-02 QT (BTU/Fr2 S)= 0.847E-18 80.2 QB (BTU/FT2 S)= 0.152E-02 QT (BTU/FT2 S)= 0.847E-18

TIME (S)= 60.000 LYRTEMP (F)= 96.5 LYRHT (FT)= 27.34 LYR MASS (LB)- 0.134E+04 FIRE OUTtqJT (BTU/S)= 0.3552E+03 VENT AREA (FT2)= 0.00 LINK= 1 LINKTEMP (F)= 82.80 JET VELOCITY (FT/S)= 2.395JETTEMP (F) = 105.0 LINK= 2 LINK TEMP (F)= 95.13JETVELOCITY (FT/S)= 2.657JET TEMP (F) = 105.8 LINK= 3 LINKTEMP (F)= 85.76JETVELOCITY (FT/S)= 1.117JETTEMP (F) = 92.9 R (FT)= 0.00 TSL (F)= R (FF)= 12.41 TSL (F)= R (FT)= 24.82 TSL (F)= R (FT)= 37.23 TSL (F)= R (FT)-- 49.64 TSL (F)= R (FT)= 62.05 TSL (F)=

92.7 QB (BTU/FT2 S)= 0.517E-01 QT (BTU/Fr2 S)= 0.847E-18 85.2 QB (BTU/FT2 S)= 0.223E-01 QT (BTU/FT2 S)= 0.847E-18 82.5 QB (BTU/FT2 S)= 0.107E-01 QT (BTU/FT2 S)= 0.847E-18 81.4 QB (BTU/FF2 S)= 0.619E-02 QT (BTU/FT2 S)= 0.847E-18 80.9 QB (BTU/FT2 S)= 0.405E--02 QT (BTU/FT2 S)= 0.847E-18 80.6 QB (BTU/FT2 S)= 0.292E-02 QT (BTU/FT2 S)= 0.847E-18

619

NFPA 204M ~ A97 R O P

Table C~4 (cont 'd, page 2 of 4 pages) The Default-Case Output

TIME (S)= FIRE OI JTI'UT (BTU/S)= 0.5328E+03 VENT AREA (FT2)= LINK = 1 IJNK TEMP (F)= 85.90JET VELOCITY (FT/S)= LINK = 2 LINK TEMP (F)= 105.74JET VELOCITY (FT/S)= LINK = .'4 LINK TEMP (F)= 90.66JET VELOCITY (FT/S)=

90.000 LYR TEMP (F)= 103.2 LYR HT (FT)= 25.65 LYR MASS (LB)= 0.216E+04

R (FT)= 0.00 TSL (F)= 102.4 QB (BTU/FT2 S)= 0.687E-01 R (FT)= 12.41 TSL (F)= 89.7 QB (BTU/FT2 S)= 0.317E-01 R (FT)= 24.82 TSL (F)= 84.7 QB (BTU/FT2 S)= 0.156E-01 R (FT)= 37.23 TSL (F)= 82.7 QB (BTU/FT2 S)= 0.908E-02 R (FT)= 49.64 TSL (F)= 81.8 QB (BTU/FT2 S)= 0.598E-02 R (FT)= 62.05 TSL (F)= 81.1 QB (BTU/FT2 S)= 0.987E-03

0.00 2.809JET TEMP (F) = 114.5 3.104JET TEMP (F) = 115.8

1.305JET TEMP (F) = 98.2 QT (BTU/FT2 S)- 0.847E-18 QT (BTU/FT2 S)= 0.847E-18 QT (BTU/FT2 S)= 0.847E-18 QT (BTU/FT2 S)= 0.847E-18 QT (BTU/FT2 S)= 0.847E-18 QT (BTU/FT2 S)= 0.847E-18

TIME (S)= 120.000 LYR TEMP (F)= 111.5 LYR HT (FT)= 23.85 LYR MASS (LB)= 0.301E+04 FIRE OUTt ' I IT (BTU/S)= 0.9470E+03 VENT AREA (FT2)= 0.00 LINK = 1 LINK TEMP (F)= 90.30JET VELOCITY (FT/S)= 3.614JET TEMP (F) = 129.3 LINK = 2 LINK TEMP (F)= 118.43JET VELOCrIY (FT/S)= 3.966JET TEMP (F) = 132.1 LINK = 3 LINK TEMP (F)= 96.66JET VELOCITY (FT/S)= 1.667JET TEMP (F) = 106.2 R (FT)= 0.00 TSL (F)= 115.6 QB (BTU/FT2 S)= 0A13E+00 QT (BTU/FT2 S)= 0.847E-18 R (FT)= 12.41 TSL (F)= 96.2 QB (BTU/FT2 S)= 0.543E-01 QT (BTU/FT2 S)= 0.847E-18 R (FT)= 24.82 TSL (F)= 87.9 QB (BTU/FT2 S)= 0.266E-01 QT (BTU/FT2 S)= 0.847E-18 R (FT)= 37.23 TSL (F)= 84,6 QB (BTU/FT2 S)-- 0.154E-01 QT (BTU/FT2 S)= 0.847E-18 R (FT)= 49.~4 TSL (F)= 83.0 QB (BTU/FT2 S)= 0.101E-01 QT (BTU/FT2 S)= 0.847E-18 R (FT)= 62.05 TSL (F)= 82.0 QB (BTU/FT2 S)= 0.728E-02 QT (BTU/FT2 S)= 0.847E-18

TIME (S)= 150.000 LYR TEMP (F)= 124.4 LYR HT (FT)= 21.85 LYR MASS (LB)= 0.390E+04 FIRE OUTIq.JT (BTU/S)= 0.1479E+04 VENT AREA (FT2)= 0.00 LINK = 1 LINK TEMI' (F)= 97.16JET VELOCITY (FT/S)= 4.364JET TEMP (F) = 149.2 LINK = 2 LINK TEMP (F)= 137.37JET VELOCITY (FT/S)= 4.754JET TEMP (F) = 153.4 LINK= 3 LINKTEMP (F)= 105.49JETVELOCITY (FT/S)= 1.998JETTEMP (F) = 117.4 R (FT)= 0.00 TSL (F)= 136.5 QB (BTU/FF2 S)= 0.158E+00 QT (BTU/FT2 S)= 0.847E-18 R (FT)= 12.41 TSL (F)= 107.0 QB (BTU/FT2 S)= 0.810E-01 QT (BTU/FT2 S)= 0.847E-18 R (FT)--- 24.82 TSL (F)= 93.3 QB (BTU/FT2 S)= 0.405E-01 QT (BTU/FT2 S)= 0.847E-18 R (FT)--- 37.23 TSL (F)= 87.7 QB (BTU/FT2 S)= 0.236E-01 QT (BTU/FT2 S)-- 0.847E-18 R (FT)= 49.64 TSL (F)= 85.1 QB (BTU/FT2 S)= 0.155E-01 QT (BTU/FT2 S)= 0.847E-18 R (FT)= 62.05 TSL (F)= 83.5 QB (BTU/FT2 S)= 0.112E-01 QT (BTU/FT2 S)= 0.847E-18

TIME (S)= 180.000 LYRTEMP (F)= 140.2 LYR HT (FT)= 19.77 LYR MASS (LB)= 0.477E+04 FIRE OI.~TPUT (BTU/S)= 0.2012E+04 VENT AREA (FT2)= 0.00 LINK = 1 L1NK TEMP (F)= 106.66JET VELOCXI3( (FT/S)= 5.008JET TEMP (F) = 171.4 LINK = 2 LINKTEMP (F)= 159.68JET VELOCITY (FT/S)= 5.414JET TEMP (F) = 176.5 LINK = 3 LINK TEMP (F)= 116.69JET VELOCITY (FT/S)= 2.275JET TEMP (F) = 130.2 R (FT)= 0.00 TSL (F)= R (FT)= 12.41 TSL (F)= R (FT)= 24.82 TSL (F)= R (FT)= 37.23 TSL (F)= R (FT)= 49.64 TSL (F)= R (FT)= 62.05 TSL (F)=

160.3 QB (BTU/FT2 S)= 0.195E+00 QT (BTU/FT2 S)= 0.847E-18 120.4 QB (BTU/FT2 S)= 0.106E+00 QT (BTU/FT2 S)= 0.84TE-18 100.2 QB (BTU/FT2 S)= 0.545E-01 QT (BTU/FT2 S)= 0.847E-18 91.8 QB (BTU/FT2 S)= 0.322E-01 QT (BTU/FT2 S)= 9.847E-18 87.8 QB (BTIJ/FT2 S)= 0.213E-01 QT (BTU/FT2 S)= 0.847E-18 85.3 QB (BTU/FT2 S)= 0.332E-02 QT (BTU/FT2 S)= 0.847E-18

TIME (S)= 210.000 LYR TEMP (F)= 158.7 LYR HT (FT)= 19.59 LYR MASS (LB)= 0.471E+04 FIRE OI 7TPUT (BTU/S)= 0.2722E+04 VENT AREA (FT2)= 96.00 LINK= 1 LINKTEMI' (F)= l18 .85JETVELOCrrY(FT/S)= 5.605JETTEMP (F) = 196.8 LINK= 2 LINKTEMP (F)= 184.03JETVELOC1TY (FT/S)= 6.021JETTEMP (F) = 202.7 LINK= 3 LINKTEMP (F)= 129.71JETVELOCITY (FT/S)= 2.530JETTEMP (F) = 144.9 TIME LINK 2 OPENS EQUALq 186.7478 (S) R (FT)= 0.00 TSL (F)= 185.7 QB (BTU/FT2 S)= 0.239E+00 QT (BTU/FT2 S)= 0.847E-18 R (FT)= 12.41 TSL (F)= 135.8 QB (BTU/FT2 S)= 0.137E+00 QT (BTU/FT2 S)= 0.847E-18 R (FT)= 24.82 TSL (F)= 108.5 QB (BTU/FT2 S)-- 0.718E-01 QT (BTU/FT2 S)= 0.847E-18

620

t

NgPA 204M a.- A97 ROP

Table C~ (cont'd, page 3 of 4 pages) The Default-Ca~ Output.

R (FI")= 37~23TSL(F)ffi R (FT)ffi 49.64 TSL (F)ffi R (FT)= 62.05 TSL (F)ffi

96.8 ~ (BTU/TT2 S)= 0.4ffTE.01 QT (BTU/FI~ S)= 0.847E-18 91.1 QB (BTU/FT2 S)ffi 0.285E-01 QT (BTU/TT2 S)= 0.847E-18 87.2 QB (BTU/FI~ S)= 0.210E-01 ~ (BTU/TT2 S)= 0.847E-18

TIME (S)ffi 240.000 L YR TEMP (F)ffi 184.9 LYgHT (FT)ffi 19.77 L-YR MASS (LB)= 0.444E+04 FIRE OUTPUT (BTU/S)ffi 0.3787E+04 VENT AREA (FT2)ffi 96.00 LINK= I LINKTEMP (F)= 134.89JETVELQCITY (FT/S)ffi 6.327.]ETTEMP OF) = 231.8 LINKffi 2 LINK TEMP (F)ffi 215.00JET VELOCITY (FT/S)= 6.741JET TEMP (F) •. 238.2 LINKffi 3 LINKTEMP (F)= 146.44JETVELOC/TY (FT/S)= 2.8~.JETTEMP (F) ffi 165.1 TIME ]:.INK 2 OPENS EQUALS 186.7478 (S) R (FT)= R (FT)= 12.41 TSL (F)ffi R (FT)= 24.82 TSL (F)= R (FT)= 87.23 TSL (F)ffi R (FT)ffi 49.64 TSL (F)= R. (FT)= 62.05 TSL (F)=

0.00 TSL (F)= 218.6 QB (BTU/YT2 S)ffi 0.299E+00 QT (BTU/FT2 S)ffi 0.847E-18 156.6 QB (BTU/TT2 S)ffi 0.180E+00 QT (BTU/TT2 S)ffi 0.847E-18 119.9 QB (BTU/FT2 S)= 0.971E~1 QT (BTU/Yr2 S)ffi 0.847E-18 !03,7 ~B (BTU/Fr2 S)= 0.582E-01 ~ (BTU/TT2 S) z 0.847E-18 95:7 QB (BTU/FT2 S)= 0.389E-0i QT (BTU/FT2 S} 0.847E-18 90.3 QB (BTU/Yr2S)= 0.288E-01 QT ( n T U / y r 2 s)= 0.847~18

217.5 LYR HT (FT)= TIME (S)= 270.000 LYRTEMP (F)ffi Free OUTPUT (BTU/S)ffi- 0.4852E+04 v ~ r r AREA (Fr2)ffi LINK--. I LINKTEMP (F)= 1 5 5 . 4 9 J E T V E L ~ (FT/S)= LINK = 2 UNKTEMP (F)= ~ 3 . 1 9 J E T V~LOCrrY (Fr / s )= LINK ffi ~ LINKTEMP (F)= lfi7.24JET~qELoc~Y (FT/S)ffi TIME L I N K 2 OPENS E~JALS .186.7478 (S) TIME t2NK s OPENS EQUALS ~e .9820 ( s ) . R (FT)ffi 0.00 TSL (F)w R (F'F)= !2.41 TSL (F)ffi R (FT)= 24.82TSL (F)= R (In')ffi 87.28 TSL (F)ffi R (FT) ffi 49,64 TSL (F)ffi R (FT) ffi 62.05 TSL (F)ffi

20.17 LYR MASS (LB)= 0.407E+04 192.00 6.854JKr TEMP (r) ffi 271.3 7.244JET TEMP (F) ffi 277.0 s .o4s jKr ~ (F) ffi 188.5

¢

254.40~B (BTU/YT2 S)= 0.339E+00.QT (BTU/TT2 S)= 0.847E-18 181.1 QB (BTU/FT2 S)ffi 0.217E+00 QT (KgU/FT2 S)ffi 0.847EA8 133.9 QB (BTU/TT2 S)ffi0.121E+00 QT (BTU/TT2 S)= 0.847E-18 112.2 QB (BTU/Fr2 S)= 0.7~E-01 ~ (BTU/Fr2 S)= 0.847E-18 101.5 QB (BTu/Fr2 S)- 0.494F_~1 ~r~(BTU/F~_ S)ffi 0.847E.18 93.7 QB (BTU/FI~ S)ffi 0,371E-01 ~YI' (BTU/TT2 S)= 0.847E-18

TIME (S)ffi 30O.000 LYRTEMP (F)ffi 253.4LYRHT (Fr)ffi FIRE OUTPUT (BTU/S)= 0~9|8E+04 VENT .AREA (FT2)ffi LINK= I LINKTEMP (F)ffi 179.59JETVELOGITY (lrf/S)ffi LINK = 2 LINKTEMP (F)ffi 289.67JET VELOCrIY (FT/S)ffi LINK= 3 LINKTEMP (F)= 189.77JETVELOCrIY (FT/S)ffi TIME LINK 1 OPENS EQUALS 282.8710 (S) TIME LINK 2 OPENS EQUAI.~ 186.7478 ( ~ . TIME I~INK 3 OPENSEQUALS 266.9820 (S) R (FT)ffi 0.00 TSL (F)= R (FT)= 12.41 TSL (F)= R (FT)= 24.82 TSL (F)= R (FT~= 37.23 TSL (F)ffi R (FT)= 49.64 TSL (F)= R (FT)ffi 62.05 TSL (F)=

2284 LYR MASS (LB)= 0.281E+04 t92:00 6.901JET TE'MP (F) = 308.7 7.195JETTEMP (F) = 311.3 S~O2SJET TEMP fF) = 211.4

287.1 QB (BTU/YT2 S)= 0.352E+00 ~ (BTU/TT2 S)ffi 0.847E-18 205.50.B (BTU/FT2 S)= 0.2.~8E+00 ~ (BTU/TT2 S)ffi 0.847D18 148.70~ (BTU/FT2 s)ffi O.138F.~0 Qrr (BTU/FT2 S)ffi 0.847E-18 121.5 QB (BTU/I~T2 S)ffi 0.851E-01 QT (BTU/TT2 S)= 0.847E-18 107.8 QB (BTU/TT2 S)ffi 0.574F~1 QT (BTU/FF2 S)ffi 0.847E-18 98.8 QB (BTU/FF2 S)ffi 0.428E-01 QT (BTU/TT2 S)ffi 0.847E-18

TIME (~= 330.000 LYR TEMP (F)ffi "284.4 LYR l i t ~T)ffi 24.25 LYR MASS (LB)ffi 0.216E+04 FIRE OUTPUT (nTU/S)ffi 0.00SSE+04VENTAREA (Fr2)ffi 192.oo LINK-= 1LINKTEMP(F)ffi 206.05JETVELOCnY(FT/S)= 7A09JETTEMP(F) = 842~ LINK = 2 LINKTEMP (F)= 322.58JET VEIX)CnY (FT/S)ffi 7.227JET TEMP (F)ffi 341.6 LINK= 3LINKTEMP(F)ffi 211.77JETVELOCrIY(FT/S)= 3.0.~JETTEMP(F) ffi 231.8 TIME LINK 1 OPENS EQUALS 282.8710 (S) TIME LINK 2 OPENS EQUALS 186.7478 (S) TIME LINK 3 OPENS EQUALS 266.9820 (S) R (FT)ffi R (FT)= R (FT)=

0.00 TSL (F)ffi 12:41 TSL (F)= 2~i.82 TSL (F)=

316.3 QB (BTU/FT2 S)ffi 0.366E+00 QT (BTUfFT2 S)ffi 0.847E-18 229.1 QB (BTU/Fr2 S)ffi 0.25TE+00 QT (BTU/FT2 S)ffi 0.847E-18 163.7~QB (BTU/FT2 S)= 0.153E+00 QT (BTU/FT2 S)ffi 0.847E-18

821

N F P A 204M - - A97 R O P

Table C,-4 (cont'd, page 4 of 4 pages) The Default-Case Output

R (FF)= 37.23 TSL (F)= R (FF)= 49.64 TSL (F)= R (FF)= 62.05 TSL (F)=

130.9 QB (BTU/Fr2 S)= 0.952E-01 QT (BTU/FT2 S)= 0.847E-18 114.2 QB (BTU/FT2 S)= 0.644E-01 QT (BTU/FT2 S)= 0.847E-18 103.0 QB (BTU/FT2 S)= 0.481E-01 QT (BTU/Fr2 S)= 0.847E-18

TIME (S)= 360.000 LYR TEMP (F)= 307.3 LYR HT (Fr)= FIRE OUTPUT (BTU/S)= 0.8048E+04 VENT AREA (FT2)= LINK = 1 LINK TEMP (F)= 233.80JET VELOCITY (FT/S)= LINK = 2 LINKTEMP (F)= 351.11JETVELOC1TY (FT/S)= LINK = 3 LINKTEMP (F)= 231.51JET VELOCITY (FT/S)= TIME LINK 1 OPENS EQUALS 282.8710 (S) TIME LINK 2 OPENS EQUALS 186.7478 (S) TIME LINK 3 ()PENS EQUALS 266.9820 (S) R (VF)= 0.00 TSL (F)= R (FT)= 12.41 TSL (F)= R (FT)= 24.82 TSL (F)= R (FT)= 37.23 TSL (F)= R (FT)= 49.64 TSL (F)= R (FT)= 62.05 TSL (F)=

24.77 LYR MASS (LB)= 0.191E+04 192.00 7.559JETTEMP (F) = 370.4 7.461JETTEMP (F) = 367.4 3.134JETTEMP (F) = 248.9

344.3 QB (BTU/FT2 S)= 0.380E+00 QT (BTU/Fr2 S)= 0.847Eo18 252.3 QB (BTU/FI~2 S)= 0.275E+00 QT (BTU/FT2 S)= 0.847E-18 178.8 QB (BTU/FT2 S)= 0.167E+00 QT (BTU/FT2 S)= 0.847E-18 140.5 QB (BTU/FT2 S)= 0.105E+00 QT (BTU/FT2 S)= 0.847E-18 120.8 QB (BTU/FF2 S)= 0.709E-01 QT (BTU/Fr2 S)= 0.847E-18 107.5 QB (BTU/FF2 S)= 0.530~01 QT (BTU/FT2 S)= 0.847E-18

TIME (S) = 390.000 LYR TEMP (F) = 327.0 LYR HT (FT) = FIRE OUTr'I_~T (BTU/S)= 0.9113E+04 VENT AREA (FT2)= LINK = 1 LINKTEMP (F)= 262.32JET VELOCITY (FT/S)= LINK = 2 LINKTEMP (F)= 376.92JETVELOCITY (FT/S)= LINK = 3 LINKTEMP (F)= 249.19JETVELOC1TY (FT/S)= TIME LINK 1 OPENS EQUALS 282.8710 (S) TIME LINK 2 OPENS EQUALS 186.7478 (S) TIME LINK 3 ()PENS EQUALS 266.9820 (S) R (FT)= 0.00 TSL (F)= R (FT)= 12.41 TSL (F)= R (FT)= 24.82 TSL (F)= R (FT)= 37.23 TSL (F)= R (FT)= 49.64 TSL (F)= R (FT)= 62.05 TSL (F)=

24.81 LYR MASS (LB)= 0.185E+04 192.00 8.168JET TEMP (F) = 397.0 7.811 JET TEMP (F) = 392.0 3.281JETTEMP (F) = 264.9

372.0 QB (BTU/FT2 S)= 0.398E+00 QT (BTU/FT2 S)= 0.847G18 275.6 QB (BTU/FT2 S)= 0.294E+00 QT (BTU/FF2 S)= 0.847E-18 194.1 QB (BTU/FT2 S)= 0.181E+00 QT (BTU/FT2 S)= 0.847E-18 150.3 QB (BTU/Fr2 S)= 0.114E+00 QT (BTU/FT2 S)= 0.847E-18 127.5 QB (BTU/FT2 S)= 0.773E-01 QT (BTU/FT2 S)= 0.847E-18 113.2 QB (BTU/VI'2 S)= 0.574E-01 QT (BTU/FT2 S)= 0.847E-18

TIME (S)= 400.000 LYR TEMP (F)= 333.5 LYR HT (FT)= FIRE OUTPUT (BTU/S)= 0.9468E+04 VENT AREA (FF2)= LINK = 1 LINK TEMP (F)= 271.98JET VELOCITY (FT/S)= LINK = 2 LINK TEMP (F)= 385.32JET VELOCITY (FT/S)= LINK = 3 LINK TEMP (F)= 254.85JET VELOCITY (Fr /s)= TIME LINK 1 OPENS EQUALS 282.8710 (S) TIME LINK 2 ()PENS EQUALq 186.7478 (S) TIME LINK 3 OPENS EQUALS 266.9820 (S) R (FT)= 0.00 TSL (F)= R (FT)= 12.41 TSL (F)= R (FT)= 24.82 TSL (F)= R (FT)= 37.23 TSL (F)= R (FF)= 4(L64 TSL (F)= R (Fr)= 62.05 TSL (F)=

24.77 LYR MASS (LB)= 0.185E+04 192.00 8.387JETTEMP (F) = 406.0 7.936JETTEMP (F) = 400.2 3.333JET TEMP (F) = 270.2

381.3 QB (BTU/FT2 S)= 0.403E+00 QT (BTU/FT2 S)= 0.847E-18 283.5 QB (BTU/FT2 S)= 0.300E÷00 QT (BTU/FT2 S)= 0.847E-18 199.2 QB (BTU/FT2 S)= 0.186E+00 QT (BTU/FT2 S)= 0.847E-18 153.6 QB (BTU/FF2 S)= 0.117E+00 QT (BTU/FT2 S)= 0.847F~18 129.7 QB (BTU/FT2 S)= 0.794E-01 QT (BTU/FT2 S)= 0.847E-18 115.0 QB (BTU/Fr2 S)= 0.589E-01 QT (BTU/Fr2 S)= 0.847E-18

622

N F P A 2 0 4 M ~ A 9 7 R O P

Option 6, HEIGHT TO BOTTOM OF CURTAIN, of the r o o m

~ roperties m e n u is used to define the he igh t above file floor of the ot tom of tile curt;tin. /~.s can be seen, in the default data, this is 15

ft. Where this he igh t is chosen to be identical to the ceiling heigilt, the user should always define the very special idealized simulat ion ,associated with an extensive, unconf ined ceiling fire scenario (i.e., by whatever means, it is assumed that file flow of the ceiling j e t is extracted f rom tile c o m p a r t m e n t at tile extremities of the ceiling). Unde r such a simulatiou, an uppe r layer never develops in file compar tment . The lower ceiling surface and fllsible links are submerged in and respond to an unconf ined cei l ingjet environ- ment , which is unaffected by layer growth. This idealized fire scenario, involving the unconf ined ceiling, is used, for example, in [2] to s imulate ceiling response and in [3] and [4] to simulate sprinkler response.

The choice of some oF, tions on a menu , such as Opt ion 4, NUMBER OF VENTS, ETC . of the room proper t ies menu , will lead to a subsequent d i sp lay / requ i rement of addit ional associated inpu t data. Menu options that necessitate multiple entries are indicated by the use o f "ETC." In the c~xse of Option 4, NUMBER OF' VENTS, ETC., th ree values are illvolved for each vent or group of vents actuated by a fi~sible link. As indicated unde r Opt ion 4, NUMBER OF VENTS, ETC., the defaul t data describe a scenario with two vents or groups of vents.

Now choose Opt ion 4, NUMBER OF VENTS, ETC., to review and modify the de f auh inpu t data ,xssociated with these two vents or groups of vents. Enter ,t [ret]. The following is displayed on the screen:

VENT NO. = 1 FUSIBLE LINK = 2 VENT AREA = 96.00000 FF2 VENT NO. = 2 FUSIBLE LINK = 3 VENT AREA = 96.00000 FF

ENTER 6 TO REMOVE A VENT ENTER VENT NO., LINK NO., AND VENT AREA (FT2) TO ADD OR MODIFY A VENT MAXIMUM NO. OF VENTS IS 5 ENTER 0 TO RETUPd~I TO THE MENU

This dispkty indicates that the two s imulated vents or group-of-vents are n u m b e r e d 1 (VENrl ' NO. = 1 ) and 2 (VENT NO. ffi 2), tha t these are actuated by filsible links n u m b e r e d 2 (FUSIBLE LINK = 2) and 3 (FUSIBLE LINK = 3), respectively, and fllat each of the two vents or ~_TOt;.ps-of-vents have a total a r e a of 96 ft" (VENT AREA = 96.00000

In tile default fire scenario it would be of interest to study the e~ect of g~mging the operat ion of all of tile four vents (total area 192 ft ~) to fusing of the closest vent link. To do so it would be necessary to first remove velar n m n b e r 2, as identified in the above menu , and then to modify the area of vent n u m b e r I;

To remove vent rmmber 2 enter 6 [ret]. Tile following is now displayed on the screen:

ENTER NUMBER OF VENT TO BE ELIMINATED ENTER 0 TO RETURN TO MENU

Now enter 2 [ret]. This completes removal of vent 2, with the following revised display on the screen:

VENT NO. = ! FUSt[BLE LINK = 2 VENT AREA = 96.00000 FI'2

ENTER 6 TO REMOVE A VENT ENTER VENT NO., LINK NO., AND VENT AREA (FT2) TO

ADD OR MODIFY A VENT MAXIMUM NO. OF VENTS IS 5 ENTER 0 TO RETURN TO THE MENU

Now modify tile characteristic~ of vent n u m b e r 1. To do this enter 1 [ret], 2 [ret], 192. [ret]. The screen will now display:

VENT NO. = 1 FUSIBLE LINK = 2 VENT AREA = 192.00000 FI'2

ENTER 6 TO REMOVE A VENT ENTER VENT NO., LINK NO., AND VENT AREA (FT2) TO ADD OR MODIFY A VENT

MAXIMUM NO. OF VENTS IS 5 ENTER 0 TO RETURN TO THE MENU

To add or reim~lemecjt vent n n m l x r 2, actuated by link n u m b e r 3, and of area 96 ft- . enter 2 [ret], 3[retl , 96. [ret]. Now re turn to the original de fauh scedlario by br inging tile area of vent n u m b e r 1 back to its original 96 f~; valtle: en ter I {ret], 2 [ret], and 96. [ret].

623

The user may now cont inue to modify or add addit ional ceiling vents or re turn to the room-proper t ies m e n u by en te r ing 0 [ret]. If the user tries to associate a vent with a link no t yet en te red in the

~i rogram, the code will warn the user, give the m a x i m u m n u m b e r of nks available in file present data set, and reques t a new link value.

If the user deletes a link that is assigned to a vent, the code will assign the link with the nex t smallest n u m b e r to that v e a l The best m e t h o d for assigning vents to links is to first use Opt ion 4 FUSIBLE LINK PROPERTIES of the base m e n u (to be discussed in C-5.5) to assign the link parameters and t hen to use Opt ion 1 ROOM PROPERTIES followed by the NUMBER OF VENTS, ETC. option to assign vent properties.

Now return to tile room-propert ies m e n u by enter ing 0 [ret], and then to the base m e n u by enter ing O [ret] again.

With the base m e n u back on the screen, choose Option 2 PHYSI- CAL PROPERTIES to review a n d / o r modify the de tauh room- property inpu t data. Enter 2 [ret].

C-5.3 Physical Properties. W h e n Opt ion 2 PHYSICAL PROPER- TIES of the base m e n u is chosen, the following physical propert ies m e n u is displayed:

MATERIAL = INSULATED DECK (SOLID POLYSTYRENE)

HEAT CONDUCTIVITY = 2.400E-05 (BTU/S LB F) HEAT CAPACITY = 2.770E-01 (BTU/LB F) DENSITY = 6.550E+01 (LB/Fr3)

1 80.00000 AMBIENT TEMPERATURE (F) 2 0.50000 MATERIAL THICKNESS (t'T) 3 MATERIAL = INSULATED DECK (SOLID POLYSTYRENE) 0 CHANGE NOTHING

The values in Opt ions I and 2 are modif ied by en te r ing the option n u m b e r and then the new value.

Now choose Opt ion 3. Enter 3 [ret]. The following m e n u is displayed:

1 CONCRETE 2 BARE METAL DECK 3 INSULATED DECK (SOLID POLYSTYRENE) 4 WOOD 5 OTHER

By choosing one of Options 1 th rough 4 of this menu , the user specifies the material propert ies of the ceiling according to the table of s tandard material propert ies in [5]. When the option n u m b e r of one of these materials is chosen, file material name, thermal conductivity, hea t capacity, and density are displayed on the screen as part of an upda tedphys ica l propert ies menu .

Now choose Opt ion 5 OTHER. Enter 5 [ret]. The following screen is displayed:

ENTER MATERIAL NAME THERMAL CONDUCTIVITY (BTU/S FT F) HEAT CAPACITY (BTU/LB F) DENSITY (LB/FT3)

The four indicated inputs are required. After these are entered, the screen re turns to an upda ted physical propert ies menu .

Now re turn to the defaul t material, INSULATED DECK (SOLID POLYSTYRENE). To do so en ter any arbitrary material n a m e with any t h r eep rope r tyva lues (enter MATERIAL [ret], 1. [ret], 1., [ret], 1. [ret]); then choose Opt ion $ MATERIAL f rom the m e n u displayed (enter 3 [ret]); and, f rom the final m e n u displayed, choose Opt ion $ INSULATED DECK (SOLID POI.,YSTYRENE) (enter 3 [ret]).

N o w r e t u r n to the base menu . Enter 0 [ret]. Choose Opt ion 3 O U T P U T PARAMETERS of the base m e n u to review a n d / o r modify the default output -parameter data. Eater 3 [ret].

G5.4 Outpu t Parameters . W h e n Opt ion 3 O U T P U T PARAM- ETER.S of the base m e n u is chosen, the following output-parameters m e n u is displayed:

I 400.000000 FINAL TIME (S) 2 30.000000 OUTPUT INTERVAL (S) 0 CHANGE NOTH][NG

N F P A 204M ~ A97 R O P

The FINAL TIME represents tile end ing time of tile calculation. The OI_ITPUT INTERVAL controls tile t ime interval between successive outputs of tile calculation results. All t imes are in seconds. For example, assume that it is desired to run a fire scenario for 500 s with an ou tpu t of results each l0 s. T h e n first choose Opt ion 1 wifll a ~tlue of 500 (enter l [ret], 500. [ret]), and then Option 2 widl a value of 10. (enter 2 [ret], 10 [ret]). The following revised output -parameters meru! is displayed:

1 500.000000 FINALTIME (S) 2 10.000000 OUTPUT INTERVAL (S) 0 CHANGE N O T H I N G

Return to tile original default output-par, 'mleters m e n u by en te r ing 1 [ret], 400. [ret], followed by 2 [ret], 30. [ret].

Now return to the hase illenu from die output-parameters m e n u by en te r ing 0 [ret].

Widl the base m e n u back ou the screen, choose Opt ion 4 FUSIBLE LINK PROPERTIES to review a n d / o l" modify the defaul t fusible-link- propert ies data. Enter 4 [ret].

C-5.5 Fusible Link Proper t i~ . W heu Opt ion 4 FUSIBLE LINK PROPERTIES of tile base inenu is chosen, the following fusible-link- propert ies m e n u is displayed:

T O ADD OR CHANGE A LINK, ENTER LINK NO., RADIUS (FF), DISTANCE BELOW CEILING (Fr) ,

RTI (SQRTIVI" SI), AND FUSE TEMPERATURE (F). MAXIMUM NUMBER OF LINKS EQUAL 10. ENTER 1 ! T O REMOVE A LINK. ENTER 0 T O RETURN T O THE MENU.

LINK# RADIUS D1STANCE (FI') RTI SQRT FUSE (Fr) BELOW f i T S ) TEMP

CEILING (F) I 6.000 1.000 400.000 165.000 2 21.200 0.300 50.000 165.000 3 44.300 0.300 50.000 165.000

Each filsible link mus t be ,'t~sigrjed a link n u m b e r (e.g., LINK # =

1), radial position from the phune-cei l ing i m p i n g e m e n t point (e.g., RADIUS = 6.00 FF), ceiling-to-link separat ion dis tance (e.g., DISTANCE BELOW CEILING = 1.00 v r ) , response-t ime-index (e.g., RTI = 400.00 SQRT[FT S]), and fixse t empera tu re (e.g., FUSE TEMPERATURE = 165.00 F).

Suppose that in tile default fire scenario it was desired to simulate the thermal response of the g roup of (fou r) sprinkler links second closest to tile fire. According to tile descript ion o f G-3 a n d Figure G- 3(a), this would be done hy adding a fonrdl link, link n u m b e r 4, at a r ad i~ ¢J~tance of ! 3.4 It, I f tbel ow the ceiling, with an RTI of 400 (ft-s) ~ / ~ a n d a fnsion tempera tore of 165°F. To do this en ter 4 [ret], 13.4 [retl, 1. [ret], 400. [ret], 165. [ret]. T h e n the following screen is displayed:

T O ADD OR CHANGE A LINK, ENTER LINK NO., RADIUS (FT),

DISTANCE BELOW CEILING (Fr), RTI (SQRT[ F r s]) , AND FUSE TEMPERATURE (F). MAXIMUM NUMBER OF LINKS EQUAL I 0. ENTER 11 T O REMOVE A LINK. ENTER 0 T O RETURN T O THE MENU.

LINK# RADIUS DISTANCE (FT) RTI SQRT FUSE (FF) BELOW (FI~S) TEMP

CEILING (F) 1 6.000 1.000 400.000 165.000 2 13.400 1.000 400.000 165.000 3 21.200 0.300 50.000 165.000 4 44.300 0.300 50.000 165.000

Note that tile new link, which was en tered as link n u m b e r 4, was sorted automatic~ally into tile list of tile original three links a n d tha t all four links were r e n u m b e r e d according to radial dis tance f rom the fire. The original link-vent ,x~slgnments are preserved in dais operation. Hence, the user need no t re turn to Opt ion 4 NUMBER OF VENTS, ETC., u n l e ~ it is desired to reassign link-vent combina- tions.

A MAXIMUM OF 10 LINK RESPONSF~S (2a2q BE SIMULATED IN ANY ONE SIMI.ILATI()N.

Now remove link n u m b e r 2 to re turn to the original default array of links. To do so en ter 11 [ret]. The following screen is displayed:

ENTER THE NUMBER OF THE LINK T O BE REMOVED

Enter 2 [ret] to remove link 2.

Now re turn to the base m e n u from the fusible-link-properties m e n u by en te r ing 0 [ret].

With the base m e n u back on die screen, choose Opt ion 5 FIRE PROPERTIES to review a n d / o r modify the default fire-properties data. Enter 5 [ret].

C-5.6 Fire Properties. W h e n Opt ion 5 FIRE PROPERTIES f rom the base m e n u is chosen, the following fire-properties m e n u is displayed:

1 2.5 FIRE HEIGHT (FT) 2 330.0 FIRE POWER/AREA (BTU/S ET2), ETC. 3 FIRE O U T P U T AS A FUNCTION OF TIME 0 CHANGE N O T H I N G

Tile value associated with Opt ion 1 is the he igh t of the base of the fire above the floor. Change this to 3 ft, for example, by enter ing l [ret] and 3. [ret]. T h e n re turn to the default data by en te r ing 1 [ret] and 2.5 [ret].

The value associated with Opt ion 2 is the fire-energy-release rate-per- fire area. I t is also possible to consider s imulat ions where die fire area is fixed by specifying a fixed fire diameter . The fire-energy- release rate-per-fire area can be changed, or the fixed fire area-type of specification can he made by choosing Opt ion 2. To do this enter 2 [ret]. This leads to a display of the following menu :

1 WOOD PALLETS,STACK, 5 F r HIGH 350 (BTU/S ET2) 2 CARTONS, COMPARTMENTED, STACKED 15 1¢1" HIGH

200 (BTU/S FT2) 3 PE BO'Iq'LF~ IN COMPAR'IMENTED CARTONS 15 FF HIGH

540 (BTU/S FT2) 4 PSJARS IN COMPARTMENTED CARTONS 15 I;T HIGH

1300 (BTU/S FT2) 5 GASOLINE 200 (BTU/S Fr2) 6 INPUT YOUR OWN VALUE IN (BTU/S ET2) 7 SPECIFY A CONSTANT DIAMETER FIRE IN FT 0 CHANGE NOTHING

Options 1 t h rough 5 o f the above m e n u are for variable-area fires. The Opt ion 1-to-5 constants displayed above on the r ight are the fire-energy-release rate-per-unit fire area- T h e y a r e taken f rom Table 4.1 of [1 ] . ff one of these options is chosen, an appropriately- upda ted fire-properties m e n u is then displayed on the screen. Opt ion 0 would lead to file re turn of the original fire-properties menu .

Opt ion 6 allows any other fire-energy-release rate-per-unit fire area of the user 's choice.

Opt ion 7 allows the user to specify the d iameter of a constant-area fire instead o f a energy-release-rate-per-unit-area fire.

Choice of Opt ion 6 or 7 mus t be followed by entry of the appropri- ate value. T h e n an appropriately upda ted fire-properties m en u appears on the screen.

To try Opt ion 7 SPECIFY A CONSTANT DIAMETER FIRE IN FEET, en ter 7 [ret]. The following screen is displayed:

ENTER YOUR VALUE FOR FIRE DIAMETER IN FT

Assume the fire d iameter is f ixed at 5 ft. Enter 5. [ret]. T h e n the following screen is displayed:

1 2.50000 FIRE H E I G H T (ET) 2 5.00000 FIRE DIAMETER (ET), ETC. 3 FIRE O U T P U T AS A FUNCTION OF TIME 0 CHANGE N O T H I N G

Now re turn to the original defaul t fire-properties men u . Enter 2 [ret]. The previous m e n u will be displayed. In this, choose Opt ion 1 W O O D PALLETS, etc. by en te r ing 1 [ret].

Opt ion ~, FIRE O U T P U T AS A FUNCTION OF TIME of the fire-

624

N F P A 2 0 4 M ~ A 9 7 R O P

propert ies m e n u allows tile user to prescribe the fire as a funct ion of time. Tile prescription involves 1) linear interpolat ion between adjacent pairs of user-specified points with coordinates (t ime in s, fire-energy-release rate in BTU/s ) , and 2) cont inuat ion of the fire to arlfitrarily large t ime at the fire-energy-release rate of the last clata point.

Now choose Opt ion 3 by enter ing 3 [ret]. Tile following screen associated with tile default f ire-output data is displayed:

I TIME(s) = 0.0O00 POWER(BTU/S) = 0.00O00E+00 2 TIME(s) = I00.0000 POWER(BTU/S) = 0.59200E+03 3 TIME(s) = 200.0000 POWER(BTU/S) = 0.23670E+04 4 TIME(s) = 400.0000 POWER(BTU/S) = 0.94680E+04 5 TIME(s) = 600.0000 POWER(BTU/S) = 0.21302E+05 6 TIME(s) = 747.0000 POWER(BTU/S) = 0.33000E+05

ENTER DATA PO][NT NO., TIME (S), AND POWER (BTU/S) ENTER 11 TO REMOVEA P O I N T ENTER 0 T O RETURN T O MENU

As discussed in G-3, with use of tile six above data points, the default s imulat ion will egtimate the fire's energy-release-rate according to the plot of Figure C-3(b).

Additional data points can be added to the fire-growth simulat ion by en te r ing the new data-point number , [ret], the time in seconds, [ret], the energy-relea.se-rate in BTU/s , and [ret].

The m a x i m u m n u m b e r of data points perufit ted is 10. The points may be en tered in any order. A sort ing rout ine will order the points by time. One point mus t cor respond to zero time.

As an example of adding an addit ional clara poin t to the above six, assume that a closer match to the "t-squared" default fire-growth curve was d~sired between 200 s and 400 s. From Section 2 it ean be verified that the fire energy-relea.se rate will be 5325 B T U / s at t = 300. To add this point to the data, thereby forcing the fire-growth curve to pa.ss exactly th rough the "t-squared" curve at 300 s, enter 7 [ret], 300. [ret], and 5325. [ret]. Tile following revised screen will be displayed:

1 TIME(s) = 0.000O POWER(BTU/S) = 0.00000E+00 2 TIME(s) = 100.0000 POWER(BTU/S) = 0.59200E+03 3 TIME(s) = 200.0000 POWER(BTU/S) = 0.23670E+04 4 TIME(s) = 300.0000 POWER(BTU/S) = 0.53250E+04 5 TIME(s) = 400.0000 POWER(BTU/S) = 0.94680E+04 6 TIME(s) = 600.~0N0 POWER(BTU/S) = 0.21302E+05 7 TIME(s) = 747.1)000 POWER(BTU/S) = 0.33000E+05

ENTER DATA FT. NO., TIME (S), AND POWER (BTU/S) ENTER I I T O REMOVE A P O I N T ENTER fl T O RETURN T O MENU

Note that the revised point, which was en tered as point n u m b e r 7, has been resorted into the original array of data points and that all points have been r enumbered appropriately.

Now remove t h e p o i n t j u s t added (wltich is now poin t n u m b e r 4). First en ter 11 [ret] . T h e n the following screen is displayed:

ENTER THE NUMBER OF THE DATA P OINT T O BE RE- MOVED

Now enter 4 [ret]. This brings the fire-growth-simulation cla.ta back to the origin,'d default set of values.

Now re turn to the fire.properties menu . Enter 0 [ret]. T h e n re turn to the b;Lse m e n u by enter ing again 0 [ret].

With the base m e n u b:tck on the screen, it is a s sumed tha t imput ing of all data required to define the desired fire s imulat ion is complete. Now choose Opt ion 0 NO CHANCES to proceed to the file-status menu. Enter 0 [retl.

0 5 . 7 Solver Paramete1,~. Users of the code will generally have no need to refer to this section (i.e., especially when learning to use tile LAVENT code a user should now skip to G-6) since they are rarely, if ever, expected to run into a situation wlaere the code is no t able to obutin a solution for a particular application or is taking an inordinate a m o u n t of t ime to produce tile solution. However, if this does happen, there are a n u m b e r of variations of the default solver parameter inputs which may resolve the problem.

Start the inpu t par t of the p rogram get to the base menu . T h e n choose Opt ion 6 SOLVER PARAMETERS. Enter 6 [ret]. The following inpu t options m e n u will be displayed:

I 0.6500E+00 2 0.1000E-04 3 0.1000E-04 4 2.000000 5 6

6 0.1000E-07 7

GAUSS-SEIDEL RELAXATION DIFF EQ SOLVER TOLERANCE GAUSS-SEIDEL TOLERANCE FLUX UPDATE INTERVAL (S)

NUMBER OF CEILING GRID POINTS, MIN=2, MAX--50

SMALLEST MEANINGFUL VALUE CHANGE N O T H I N G

Tile solvers used in this code consist of a differential equat ion solver DDRIVE2, used to solve the set of differential equat ions associated with tile layer and the fusible links, and a Gauss-Seidel/Tridiagonal solver us ing the Crank-Nicolson formalism to solve tile set of partial differential equations associated with tile hea t conduct ion calcula- tion for the ceiling. Since two different solvers are being used in file code, there is potential for the solvers to become incompatible with each other, particularly if the uppe r layer has nearly reached a steady-state t empera ture but the ceiling is still increasing it's temperature . When this occurs, the differential equat ion solver will try to take t ime steps that are too large for the Gauss-Seidel solver to handle and a growing oscillation in the ceiling t empera tu re variable may occur. By reduc ing tile FLUX UPDATE INTERVAL, the

OWing oscillation may be suppressed. The smaller the FLUX DATE INTERVAL, the slower tile code will run.

The GAUSS-SEIDEL RELAXATION coefficient may be changed to p roduce a faster r u n n i n g code or to handle a case tha t will no t run with a different coefficient. Typical values of this coefficient should range between 0.2 a n d 1.0.

The DIFF EQSOLVER TOLERANCE and the GAUSS-SEIDEL TOLERANCE may also be changed. Decreasing or increasing these values may provide a faster r u n n i n g code for a given case and by decreasing the value of the tolerances, the accuracy of the calcula- t ions may be increased. If the tolerance values are made too small, the code will ei ther r un very slowly or no t run at all. Suggested tolerances would be in the range of 0.00001 to 0.0(~)001.

Consis tent with file model assumptions, accuracy in the radial ceiling tempera ture distr ibution a r o u n d file p lume/ce i l ing i m p i n g e m e n t poin t is d e p e n d e n t on tile NUMBER OF CEILING GRIDPOINTS. Relatively grea ter / lesser accuracy is achieved by us ing relatively more / f ewer grid points. This leads, in turn, to a relatively slower/faster compute r run.

0 6 File Status - Runn ing the Code. W h e n Opt ion 0 NO CHANGES of the base m e n u is chosen, the following file-status m e n u is displayed:

1 SAVE TH E FILE AND RUN THE CODE 2 SAVE THE FILE BUT DON'T R U N THE CODE 3 DO N' T SAVE THE FILE BUT RUN THE CODE 4 ABORT THE C A L C U l a T I O N

If one of the save opt ions is selected, tile user will be asked to supply a file n a m e to designate the file where the newly genera ted inpu t data is to be saved. Tile p rogram will automatically create the new file. File names may be as long as 8 characters and shou ld have a c o m m o n extender such as .DAT, example MYFILE.DAT. The m a x i m u m len. ~ l l tha t may be used for the total l eng th of input or ou tpu t files ~s 25 characters. For example, G:KSUBDIREGTWILENAME.DAT would allow a file n a m e d FILENAME.DAT to be read f rom the subdirectory SUBDIRECT on file C drive. To read a file f rom a floppy disk in the A drive, use A:FILENAME.DAT. If Opt ion 4 is chosen the p rogram will end without anyfi le being saved.

A reques t for an ou tpu t file n a m e will appear on the screen. F'de names may be as long as 8 characters and shou ld have an ex tender such as .OUT such tha t tile ou tpu t files can easily be recognized. To ou tpu t a file to a floppy disk in the A drive, n a m e the file AcFILENAMF_.OUT. To ou tpu t a file to a subdirectory other than tile one which is res ident to the program, use C:\$UBDIRECT~FILENAME.OUT for the subdirectory SUBDIRECT.

Once tile ou tpu t file has been designated, the program will begin to execute. Tile s t a tement PROGRAM RUNNING will appear on the screen. Each time the p rogram writes to tile ou tpu t file, a s ta tement such as T = 3.0000E01 S will appear on the screen to provide the user with tile present ou tpu t tame.

0 7 The Ou tpu t Varlables and the Ou tpu t Options. The program

625

N F P A 2 0 4 M - - A 9 7 R O P

~ enerates two separate ou tpu t files. An exarnple of die first ou tpu t le is a p p e n d e d :it tile end of tids document . This file is n a m e d by

die user and consists of a listing of die inpu t data plus all d ie relevant ou tpu t ~triables in a format where die ou tpu t units are specified and the m e a n i n g of all bu t d / ree of tile ou tpu t variables are clearly specified. These latter variables are TSL, QB, and QT which are the tempera ture of tile ceiling inside the enclosure, die- ne t hea t transfer flux to die bot tom surface of tile ceiling, and tile ne t hea t transfer flux to tile top snrface o f the ceiling. The variables are ou tpu t as a funct ion of radius with R = 0 being tile center of tile fire p lume projected on die ceiling. ()tiler abbreviations include LYR TEMP, LYR HT, LYR MASS,JET VELOCITY, and JET TEMP which are die upper layer (layer adjacent to the ceiling) temperature , he ight of die upper layer interface above tile floor, mass of gas in die layer, ceiling.jet velocity and tempera ture at the posi t ion of each fusible link. The VENT AREA is the total area o f roof vents open at tile t ime of output .

The second oll tpnt file, GRAPH.OUT, is used by die graphics program, GP, APH. GRAPH is a Fortran program which makes use of a graphics software package to produce graphical ou tpu t of selected ou tpu t variables.[6, 7] To use the graphics program, t he file GRAPH.OUT must be in tile same directory as the program, GRAPH. GRAPH is a m e n u driven program which provides the user widl tile ability to plot two sere of variables on the PC screen. An option exists which permits the user to pr int die plots f rom tile screen to a printer. If the user has all a t tached EPSON-compatible printer, enter 'e ' to produce a plot us ing tile printer. If the user wishes to genera te a PostScript file for use on a laser printer, enter 'p ' and provide a file name when the file name p rompt appem's in the uppe r left hand c o m e r of the graph. To exit to screen mode from the graphics mode , en ter 'c'. The file GRAPH.OUT will be destroyed each t ime the code LAVENT is run. If the user wishes to save die graphics file, it mus t be copied us ing the DOS copy c o m m a n d into ano the r file with a different file name.

To demons t ra te the use of GRAPH, start dae p rogram by en te r ing 'g raph ' [ret]. GRAPH will read in dae graphics ou tpu t file GRAPH.OUT and tile following screen will be displayed:

ENTER 0 TO PLOT POINTS, ENTER 1 TO PLOT AND CONNECT POINTS

The graphics presented in Figures C-7(a) to C-7(e) were done wida GRAPH us ing option 0. Enter 0 [ret] and die following graphics m e n u is displayed:

ENTER THE X AND Y VARIABLES FOR THE DESIRED TWO GRAPHS 1 TIME 2 LAYER TEMPERATURE 3 LAYER HEIGHT 4 LAYER MASS 5 FIRE OUTPUT 6 CEILING VENT AREA 7 PLUME FLOW 8 LINK TEMPERATURE 9 JET VELOCITY AT LINK I 0 JET TEMPERATURE AT LINK

Two plots can be s tudied on a single screen. For example, f rom tile default s imulat ion ,x~sume that displays of tile plots of Figure C-7(a) and G-7(b), LAYER HEIGHT vs TIME and LAYER TEMPERATURE vs TIME, respectively, are desired. T h e n enter 1 [ret], 3 [ret], 1 [retl, and 2 [ret]. The program will respond widl tile prompt:

ENTER THE TITLES FOR THE TWO GRAPHS, 16 CHARACTERS MAX.

The user migh t choose titles which would identify particular cases such ,as LY HT RUN 100 [ret] and LY TEMP RUN 100 [ret]. If die fide is chosen to be longer dlan 16 characters, it will be t runca ted to 16 characters. After the titles have been en t e r ed the p rogram will respond widl:

ENTER 1 FOR DEFAULT SCALING, 2 FOR USER SCALING.

626

30

29 .

28

2 7

26

v

~ 25

23

22

21

2O

0 I I I I l i

1 O0 200 300 400

"rime Is)

Figure C~7(a) Plot of the height of the smoke layer ~aterface vs dme for the default simulation.

340

320

300

280

260

240

o v

~- 220

, .J

160

140

120

100

80 0

I I I I I I I

I i i , , I 100 200 300 400

Time (s)

Figure C-7(b) Plot of the temperature of the smoke layer vs time for the default simulation.

NFPA 204M w A97 R O P

400 , , , , w , ,

350

300

o v

E sso

E

2oo

150

100

50 | Sl i t | | t

0 1 O0 200 300 400 Time (s)

F'~;ure C-7(c) Plot of the closest (R = 21.2 ft) vent-link temperatures vs time for the default simulation.

260

260

240

220

E" 200 o v

- I

160

~ lOO - J

140

120

100

D

8 0 " l e i i i i i i

0 1 00 200 300 400 Time (s)

Figure C-7(d) Plot o f the far (R = 44.3 It) pair o f vent-link tempera- tures vs time for the default simulation.

627

260

240

220

200

E" 160

160 . I ¢ .G . . J

140

120

100

• I 8 0 i i

0 300 400 I I I I

100 200 Time (s)

Figure C-7(e) Plot o f the closest (R = 6 ft) sprinkler-link tempera- tures vs time for the default simulation.

If the user chooses option 1, tile desired plots will appear on the screen with an internal scaling for the X and Y axis of each graph. If the user chooses option 2, the program will respond with the following prompt:

ENTER THE MINIMUM AND MAXIMUM VALUES FOR THE X AND Y AXIS OF EACH GRAPH. ENTER 0 FOR THE MINIMUM AND MAXIMUM VALUES OF EACH AXIS WHERE DEFAULT

SCALING IS DESIRED. FOR EXAMPLE, VALUES SHOULD BE ENTERED AS 0.,100.,0.,200.,10.,50.,20.,100. [RET] FOR XI (0-100), Yl(0-200), X2(10-50), Y2(20-100).

Use of this option allows a number of different cases to be compared usingsimilar values for the X and Y axis o f each graph. All eight numbers must be entered and separated with commas before enter ing [ret]. Once the entry is made, the plots will appear on the screen. Note that this option permits a mixture of default scaling and user specified scaling.

Once a pair of plots are displayed on the screen, the user would have the choice of enter ing "p' or 'e ' , to obtain a hard-copy plot of the graphs, or of enter ing 'c' to exit the graphics mode.

To plot a second pair of graphs, the user would exit the graphics mode by enter ing 'c' and then repeat the above process by enter ing 'graph ' [ret], etc.

If the user selects plots which involve variables defined by Options 8, 9, or 10, then, following the entry 8 [ret], 9 [ret] or 10 [ret], the following p rompt for identifying the desired link number (in the default simulation with 3 simulated links) will be displayed immedi- ately:

ENTER LINK NUMBER, MAXIMUM NUMBER = 3

The user then enters the desired link number followed by [ret], and continues entering the remaining input data which define the desired plots.

N F P A 2 0 4 M i A 9 7 R O P

As an example of genera t ivg link-related plots, consider displaying tile pair of plots LINK TEMI 'EP~TURE vs TIME and JET VELOC- ITYAT L I N K ~ TIME for lirtk n u m b e r 3 in the default simulationo First enter 1 [ret] (for TIME on file X axis) and 8 [ret](for LINK TEMPERATURE on the Y axis). At tiffs point, "ENTER LINK NI.IMBER ..." would be displayed on the screen. Cont inue by enter ing 3 [ret] (fl)r link n u m b e r 3). This would complete the data entry for file first of the two plots. For the second plot en ter 1 [ret] (for TIME on the X axis) and 9 [ret] (for LINK TEMPERATURE on the Y axis). At this point, "ENTER LINK NUMBER ..." would be displayed a second time. T hen conch*de data input for tile pair of plots by en te r ing 3 [ret] (for link n u m b e r 3). At this poin t the desired pair of plots would be displayed on the screen.

C-8 An Example Simulation - The Defauh Case. This section presents and reviews briefly the simulation of tim default case.

The tabular ou tpu t of the default s imulat ion is presented in Table G-4. Plots of tile layer-interface he igh t and of the layer t empera ture as f imctions of t ime are plotted in Figures C-7(a) and C-7(b), respectively. Plots of the thermal resl)onse of the two pairs of vent litlKS and tile pair nf sprinkler links closest to die fire are presented in Figures C-7(c) to C7(e ) , respeclively.

From Table (i;-4 and Figures C-7(c) to C7(e ) it is seen that the sequence of link fi~sing (at 165 F) is predicted to be the near pair of vents at 187 s, tile l.u" pair of vents at 267 s, ztnd tile pair of closest sprinklers at 283 s. Al though tile sprinkler links are closer to the fire than any of the watt links, and a l though all links bave the same flise temperatures , the sinullatiou predicts that the sprinkler links fi~se after all of the veto links. There are two reasons for this. First, the RTI of tile sprinkler links are larger than those of the vent links and, therefore, slower to respond thermally. Second, tile two sprinkler links s imulated :ire far e tmugh from tile ceiling ,as to be below tile peak tempera ture of the ceiling j e t which is relatively thin at the 6 ft radial position (see tile lower sketch of Figure C~2).

The effect on layer growth of fusing of die two pair of vent links and opening of their correspondit tg vents at 187 s and 267 s can be noted in Figure C7(a) . Note that tile open ing of the first pair of vents effectively stops tile rate-nf-increase of layer thickness and opening of the second pair of vertts leads to a relatively rapid rate-of- decrease in tile layer thickness. All of this is of course occurr ing at times when tile energy-release-rate of the fire is growing rapidly.

.&s can be seen it* Figure G-7(a), lip to tile 400 s of s imulat ion t ime tile smnke is still conta ined in the original cur ta ined c o m p a r t m e n t and h:ts no t "spilled over" to ac!jaceut spaces. From this figure it appears that with no venting, the layer would have d ropped below tile bot tom of the curtain boards prior to fitsing of the first sprinkler lin "1"1~. This could be conf i rmed with a second s imulat ion run of LAVENT, where :ill refit action w:ts removed f rom the default data.

C-9 References for Appendix C.

1. GuideJbr Smoke and t-k~,~t Venting, NFPA 204M, National Fire Protection ~ssocialion, Qoirtcy MA, 1982.

2. Cooper LX. and Stroup, D.W., "Thermal Response of l .]ncnnfined Ceili~,gs Above (;rowing Fires and the Impor tance of (;onvective Heat Transfer,"Journal of Heat Tran.~m 109, pp. 172-178, 1987.

3. Evans. D.D., "'Cah:ulating Sprinkler Activation Time in Compar tments , " Fire St~e~..[ournal, 9, pp. 147-155, 1985.

4. Stroup, D.W. and Evaus, D.D., "Ilse of Compute r Fire Models for A n a l ~ i n g Thermal Detector Spacing," Fire SafetyJourruzl. 14, pp. 33-45, 1988.

5. (?;ross, D., "Data Sources for Parameters I lsed in Predictive Model ing of Fire Growth and Smoke Spread," NBSIR 85- 3223, Natio,'tal Bureau of Standards (presently National Institute of Standards and Teclmology), Gai thersbnrg MI), September 1985.

6. Kaharter, D., Moiler, C., and N:tsh, S., NumaicalMethods a,ut &~war~;. Prentice Hall, 1989.

7. K~tbaner, D., NIST, p,-ivate communica t ion .

Appendix D Sample Problem Using Engineering Equations (Hand Calculations) and LAVENT

Abstract

The following example p rob lem illustrates the use of the informa- tion, eng ineer ing equations, hand calculations and compu te r model described in this document . The impact of a fire on a non- spr inklered retail storage bui lding and its occupants is assessed. The effects of an ant icipated fire on the subject bui lding are predicted, and the impact of smoke and beat vents are illustrated.

Design goals and objectives were developed and a h igh chal lenge fire, likely to occur in the subject building, was identified.

The fire impact was assessed us ing d~ree different methods: • Hand calculations a s suming a quasi-steady fire • Hand calculations a s suming a con t inuous growth (t-squared)

fire • Tile compute r model LAVENT

Hand calculations are useful for quick estimates of the impact of vents on fire effects. However, hand calculations are not able to assess time-varying events. A n u m b e r of simplifying assumpt ions have been used to facilitate problem-solving via algebraic equations. Hand-calculated results are considered valid, but produce somewhat conservative estimates of fire effects such as upper layer tempera- ture. A compute r model, like LAVENT, will generally provide a more complete analysis of the f i re-produced effects and, in some instances, is preferable over hand calculations.

Introduction

The following example problem illustrates the use of engineer ing equations and a compute r model to assess the impact of a fire in a nonspr ink le red retail-storage building. The prob lem illustrates the impact of vents and predicts the effect o f the anticipated fire on the building.

Goal

Develop a vent design for the subject bui lding which will maintain a tenable env i ronmen t for a pe r iod of t ime at least equal to the t ime required to evacuate the building, and to mainta in the ho t upper layer a m i n i m u m of 3 meters above floor level until the local Fire Depar tmen t enters the building.

Objective

Determine the vent area required to mainta in the smoke layer at least $ meters above floor level for 300 seconds following detect ion of the fire by an automatic detect ion syste~2n. Also, limit the heat flux at floor level to a m a x i m u m of 2.5 k W / m , the threshold irradiance causing severe pain to exposed skin [ 1 ], dur ing the t ime required for evacuation of the bui lding occupant, s.

Building Details

The building is 73 m wide, 73 m long, and is 9.1 m high. The building is no t subdivided nor is i tprovided with a sprinkler system. The roof is an insulated deck (solidpolystyrene). A complete fire a larm system is to be installed us ing heat detectors spaced 15.2 m on center and 6.1 m from walls. ])t~ectors have an activation tempera-

o • * / ture of 74 C, RTI of 55 (m s) , and are located 0.3 m below the roof. Sixteen vents ,are proposed, with vents spaced 18.3 m on center. Vents are located 9.05 m f rom walls. The vents are activated by fusible I IlL)ks having an activation t empera tu re of 74°C, an RTI of 28 (m s) " - , and located 0.3 m below the roof. Inlet air openings are equal to 1.5 the total vent area. See Figure D-1.

Occupancy Details

The bui lding is to be occupied for retail storage. This analysis deals with a fire in rack storage of sofas in the center of the building. The sofas are s tored in two racks. The racks are each 9.75 m long, 1.2 m wide, and are separated f rom each o ther by 2.4 m. Distance to combustibles s u r r o u n d i n g the racks is sufficient to prevent fire spread to those combustibles dur ing the t ime per iod covered by this analysis. The sofas are identif ied as spec imen F32 conta ined within Table 5-5.3(d). Data for the same sofasrare conta ined within a data base of Hazard I [2], where the sofas are identif ied as spec imen UPS001. Each sofa contains 51.5 kg of combust ible mass. The sofas are wrapped in polyethylene. Each rack has four tiers of storage, four sofas per tier, and a total s torage he igh t of 7.6 m.

628

N F P A 2 0 4 M ~ A 9 7 R O P

i

73 m

/ m m m

m i / m

m m m m ~ Smoke and heat ven~

/ Im I I 73 m >

Figure D-I Vent plan view

I g n i t i o n

An ignition is :~sumed to occur in a sofa on the first tier of one of the racks. Ignition of a sofa o11 tile first tier is a probable worst-case scenario and, ms a practical matter, is a location where ignidon may be expected. Also, placing the fire near floor level results in near- m,xximum smoke product ion (en t ra inment ) .

Fire Growth

First, an estimate of file ant icipated fire growth mus t be developed. A "t-squared" fire will be assumed - - see 6-1.4.6.1 and A-6-1.4.6.1. In a "t-squared" fire

Q = (Zgt 2, where

Q = total hea t rele,'x~e rate (kW)

0~g = tire growth coefficient

t = time (seconds)

The dam. base within Hazard I [2] contains data f rom furni ture calorimeter tests of sofas. A sofa (UPS001) was tested and demon- strated a growth t ime (tg) to 1 MW of approxirmately 200 seconds. The fire in tile sofa in tiIfis example is a s sumed to have a growth t ime of 150 seconds to 1 M~A r as a reasonable, conservative, approximat ion of the ant icipated fire in tile sof,xs stored in the example building. If a more precise estimate of the bu rn ing characteristics of an individual sofa is necessary, the exact sofa to be s tored in the building could be tested in a calorimeter. A fire growd/dmeLpf 150 seconds results in an 0~, for tile individual sofa of 0.044 kW/s (see equat ion 6-I 1 b). That%:

(Zg = 1,000/tg 2 = I,~)00/1502 = 0 .044kW / s 2

Accordingly, fire growth in the first sofa ignited may be approxi- ma ted by a fast ( 0 ~ = 0.044 k W / s 2) "t-squared" tire. Fu~her , according to 6-1.4.~3, 0tg is directly proport ional to the storage height. Therefore, the fire grox~h~ constant ( (X_) for sofas stacked four high is 4 t imes 0.044 kW/s or O~g equals (~.18 kW/s 2 and initial tire growth is approx imated as

Q = O~gt 2, where: Of, g = 0 . 1 8 k W / s 2

Fire growth in the first rack of sofas results in radiant heat transfer to a second rack of sofas separated from the first rack hy 2.4 m. It must be de te rmined when the second rack of sofas ignite. The fire size, when ignition of the second rack of sofas occurs, is de te rmined us ing equat ion 6-10 with its te rms rearranged:

Q = (W/0.042) 2 where:

W = aisle width (meters)

Q = tire ou tpu t (kW)

Q = (2.4/0.042) 2 = 3265 kW ----- 3250 kW

Next, the t ime of ignition of the second rack is compu ted us ing

t 2 Q = O~g

t = (Q/ / (gg ) 1 / 2 = (3250/0 .18)1 /2 = 134 seconds

W h e n the second rack o f sofas is ignited at 134 seconds, the tire growth coefficient, (~g , for the two racks bu rn ing toge ther is a s sumed to double the value for the first rack burn ing alone ( O~g = 0.36 kW/s2) . At tha t time, the fire appears to have originated at effective ignition time, tOg. For t > 134 seconds:

Q = 0.36 ( t - tog) 2 kW

Determine tOg as follows:

3250 = 0.36 (134- tOg) 2

tog = 39seconds

Then , for t > 134 seconds:

Q = 0.36 ( t -39 ) 2

The m a x i m u m fire size is now estimated. Sofa UPS001 f rom the Hazard I database [2] (Specimen F-32 in Table 5-5.Bd) has a peak bu rn ing rate of 3120 kW. M a x i m u m fire size, Qmax, is based on the assumpt ion that all 32 sofas are bu rn ing at their individual peak rates, 3190 kW.

Qmax = 32 (3120) ~ 100 MW

Now, the time, tmax, to reach 100 MW mus t be de t e rmined using:

Qmax = 0.36 ( t - 39) 2 when Q = 100,000 kW

100,000 = 0.36 ( tmax-B9) 2

tm,-Lx = (100,000/ .3611/2 + 39 = 566 seconds

An estimate of fire durat ion, tend, is now made us ing data f rom the Hazard I [2] database for sofa UPS001:

Individual sofa combust ible mass = 51.5 kg Sofa effective hea t of combust ion = 18,900 kJ /kg Max imum tire size = 100,000 kW

The mass c o n s u m e d from t = 0 to t = 134 seconds is de te rmined from the total hea t release as follows:

134

134 0.18 3 ( 0 . 1 8 / 3 ) (134/3 144,366kJ . Total hea~ release ~34~0Qdt = - g - - t = = trom t to t =

0

620

N F P A 2 0 4 M - - A 9 7 R O P

Since Q = fiah - - see Equat ion 5-1 - - mass loss, A m, for t = . c .

134 seconds, ts determJ ned ,xs follows:

m m = 144,366 kJ/18,O00 kJ /kg = 7.6 kg or ----- 8 Kg

The mass consumed from t = 134 seconds to tmax, the t ime when tile m a x i m u m fire size is reached, is similarly de t e rmined f rom the total heat release rate ,alter 134 seconds, as follows:

t max 566 I Q d t = I 0 . 36 ( t _ 3 9 ) 2 d t = 566-39i

134 134 1 3 4 - 3 9

527

0.36132d1~ = 0-36/3 ( t ) 31

95

Total heat release f rom t = 134 to t = 566 = 0.12 [(527) 3 - (9~31 = 17.460,697 kJ, a~ad tbe m ~ s lost, /..x m, is /_Am = 17,460,697 kJ/18,.CKKl kJ /kg = 923.8 _~ 924 kg

Approximately (924 + 8) kg = 9:?;2 kg is consumed du r ing the 566- second time h iterval required to reach Qmax- T he total combust ible m;Lss is 51.5 kg x 32 = 1648 kg. Therefore , a round (1648 -932) kg = 716 kg is available to I)m'n at Q = ")L~lax : 100 MW, ,after t = 566 seconds, f rom wbich the fire durat ion can be calculated as follows:

Qmax ( t end - 566) = 100,000 (ten d -566) = 716 (18,900)

tend = 5 6 6 + 7 1 6 (18,9001 / 100,000 = 701.3seconds _= 700 s e c o n d s

The coml)ustible m,xss of the sofas alone is able to suppor t the anticipated fire for approximate ly 700 seconds. In reality, the fire in tile sofas would reach a m,'Lxhnum of 100 MW at 550-600 seconds and burn briefly at the 100-MW peak until the combust ible mass available began to be consumed , at wlfich time the fire 's rate of beat release would begin to decline. Using a t en d of 700 seconds is conservative.

In summary, the analysis to this point leads to dae following estimate for the ant icipated fire:

9 Q = o.18t" for O < t - < 1 3 4 s e c o n d s

Q = 0.36 ( t - 39) 2 for 134 < t -< 566 seconds

Q = 100,000 kW for t > 566 seconds

See FigaJre D-2.

Fire Detection

The t ime of fire detect ion is now calculated given tile fire and building a.s described. Tile t ime of detection will be es t imated Ixlsed upon tile actual composi te fire described above. Detection t ime can

be calculated us ing equat ion 6-14. DETACT-QS (see 6-1.4.7.3.2) is a readily available computat ional tool tha t per forms this calculation.

A complete fire a larm system is to be installed us ing hea t detectors spaced 15.2 m on center (6.1 m f rom walls), having an activation t empera tu re o f 74°C and an RTI of 55 ( m * s ) l / 2 . Assuming the ant icipated fire is as described above, the m a x i m u m distance f rom a detector to the fire axis is the diagonal [2 (15 .2 /2)211/2 = 10.7 m, ambien t t empera ture is 21°C, a n d t h e fire is 0.5 m above floor level, DETACT-QS predicts the activation of a hea t detector at 230 seconds. In the event quicker detect ion is j u d g e d necessary, smoke detector activation can be predicted by DETACT-QS us ing the gu idance provided in 6-1.4.7.2.2. Detection t ime for smoke detectors ~s based on the gas tempera ture rise at the detector site. Smoke detector activatio n can be approximated us ing DETACT-QS, assuming die smoke detector will respond like a heat detector which has a small RTI [e.g., 1 (m.s ) 1/2] and a certain activation tempera- ture above ambien t (see 6-1.4.7.2.2). Tests, involving burn ing of the sofa upholstery with the actual detector to be installed, have de te rmined tha t 10°C above ambien t is a representative activation condition. Assuming smoke detectors are spaced 9.1 m on center (located a m a x i m u m of 6.5 m f rom the axis of tiae fire), smoke detector activation is predicted by DETACT-QS at 48 seconds.

Using DETACT-QS, vent operat ion is predic ted us ing fusible links having an activation tempera ture of 74°C and an RTI of 28 (re°s) 1/2. Assuming the ant icipated fire is located in the center of the building, the ambien t tempera ture is 21°C, and assuming the fire is 0.5 m above floor level, activation of the first vents (equidis tant f rom the fire) separated [2(18.3/21211/2 = 12.9 m f rom the fire is predic ted by DETACT-QS at 228 seconds. The nex t set of vents (equidistant f rom the fire at 28.9 m) are predicted to open at 317 seconds. Similarly, the third set of four vents, 38.8 m f rom the fire axis, open at 356 seconds. All 16 vents are open at 356 seconds. Alternatively, if fusible links having the same RTI as the hea t detectors [55 ( re°s)1/2] are used, all vents are predicted to be open at 384 seconds.

Vent Design

Of main concern in this example is the tempera ture of the smoke layer, which governs the hea t flux radiated to the floor. Assuming an emissivity o f 1 and a configurat ion factor of 1, the radiant heat flux at the floor is calculated as follows:

Fluxfl = k E O T 4 wbere

T = t empera tu re of the layer (°K)

k = Stefan Boltzmann constant = 5.67 E-11 k W / m 2 K 4

E = emissivity = 1

O = configurat ion factor = i

Fluxfl = (5.67 E-I1) T 4 k W / m 2

A

X

e-.

"6

n-

120

100

80

60

40

20

O ~ 0

q = 0.36 ('

q = 0.36 (t) 2 for t < 134 and

q =0.36(t - 39) 2 for t > 134

100 200 300 400 500 Time (s)

600 700 800

Figure D-2 Fire output .

630

NFPA 204M i A97 ROP

9 For a flux limit of 2.5 k W / m - , ;is stated in the objective, rile t empera ture of the smoke layer is calculated as 458°K, or 164°K above the ambien t teml~eratnre of 294°K.

Steady Fire

Smoke Layer Tempera tu r e

First, condit ions foil owing a t t a inment of the m a x i m u m beat release rate of 100 MW can be exanfined, i.e., at t imes greater rimn 566 seconds, assumir~g a smoke layer at tile lowest acceptable height, 3 m above the floor. (The heat detector installation contempla ted was calculated to provide alarm at 230 seconds; 300 seconds following detection places the t ime of interest ,~ 550 seconds, close to the a t t a i n m e n t o f the maxirmnn beat release rate.)

The effective d iameter of the fire is required for the calculations. This d iameter can be de t e rmined with the aid of equat ion 6-13, sett ing Q = 100,000 kW and selecting an appropriate value for the heat release rate per uni t floor area Q". T he two racks facing each o ther across the 2.4 m wide aisle are ~75 m long and 1.2 m wide - see Figure [)-3. The he'.tt release rate per uni t area is taken as the fully-involved heat release rate, 100,000 kW, divided by the com- bined area of the two racks pins the aisle, or 9.75 • 1.2 • 2.2 + 9.75 * 2.4 = 46.8 m ~. Accordingly, the heat release rate per un i t area is:

Q" = 100,000/46.8 = 2136 k W / m z

Effective fire diar~

Effective fire diameter

Fire area

1.2 m Rack 1 ] T

2.4 m

,l ! [ 1.2 m Rack 2 !

-I

Figure D-3 Effective fire diameter .

Tiffs value can be a s sumed to be representative of most of the fire history, except for the initial st-age. The effective d iameter of the fire at 100,000 kW is then, ns ing equat ion 6-13:

! / 2 D = [(4 • 100,0O0])/ ( n • 2 1 3 6 ) 1 = 7 . 7 2 m

Equation 6-9 is nsed to estimate the smoke layer t empera ture rise. Tlie mass flow rate in the p lume ~¢ it enters the smol~e layer, mp, is calculated f i om equat ions 6-2 or 6-3, d e p e n d i n g on whether rile f lame height is smaller or larger than the he igh t of the smoke layer above tile base of the fire, 3 - 0.5 = 2.5 m. The flame he igh t is calculated f rom equat ion 6-1 :

L = (-1.02 • 7.72) + (0.235 * 100,0002/5) = 15.6 m

which is greater than the he ight of the smoke layer. (It is even greater than the ce ng be gbt so that the f lames will impinge on the ceding and flow radial l /outward.) Therefore , the mass flow rate m the p lume as it enters the smoke layer is calculated f rom equat ion 6- 3,~s follows (.'L~smning ~).2c = 0.7 Q):

l:flp = [o.0056 (0.7-100.000) 1 [2.5/15.61 = 62.8 kg / s

Now the tempe,ztture rise in the smoke layer can be est imated us ing equat ion 6-9, with Cp = 1.00 kJ /kg•K a n d t h e value o f r = 0.5 r e c o m m e n d e d in 6-'1,3.4.

AT = 0.5 * 70,000/(I.00- 62.8) = 557°K

This value is considerably above 164~K, and therefore the floor radiant beat flux cart be expected to be m u c h h igher than the limit

2.5 k W / m 2. Using tile equat ion for r ad ia r~hea t flux to the floor presented previously, the value 29.7 k W / m is calculated for a smoke layer t empera tu re of 557 + 294 = 851°K.

Not only is rile smoke layer temperature , 557 + 21 = 578°C, so high tha t it p roduces unacceptable levels of radiant flux at the floor, bu t it is also close to tile level, 600°C, where fire can flash over all the combustibles unde r rile smoke layer (see 6-1.5.1.1). Fur thermore , it exceeds the value, 540°C, where unpro tec ted steel begins loosing s t rength (see 6-1.5.1.2). Directly over the fire (see 6-1.5.1.2) the tempera tures may locally reach 1155°C (from equal ion 6-9 with r = 1 ), far in excess of the threshold for steel damage.

Sizing o f Vents

This building a r r a n g e m e n t will not mee t design objectives. However, it may be instructive to investigate the vent ing require- ments in order to illustrate general procedures which migh t be used to develop alternative designs.

All 16 vents are predicted tO be open prior to 566 seconds - - the t ime of interesL

Tile aerodynamic vent area, Ava, is de t e rmined with the aid of equat ion 6-8:

( , ) ~ 2 _ x l / 2 r T 0 Arp] l / 2 A .11/2 fiav =,,.vor,) [ a.j ,-,vu

At equil ibrium, the mass 0ow th rough the ve~ts is equal to the sqloke product ion rate, I n , . Substi tut ing m ° = a2.6 kg/s for 9 m v in equat ion 6-8, togetfier with r o = 1.2 k ~ / m " , g = 9.81 m / s - ,

T O = 294°K, DT = 559°K, T = 2 9 4 + 5 5 9 = 85~°K, a n d d = 9.1 -3 = 6.1 m, the equat ion can be solved for the aerodynamic vent area. Tim result is:

Ava = 10.04 m 2

The vents are a s sumed to have a discharge coefficient of 0.61, a n d therefore, tile cor responding actual vent area is (see 6-1.4.2):"

2 Av = 10.04/0.61 = 16.46 m (geometric vent area) ---- 16.5 m 2

Tile bui lding design contemplates that inlet air openings will be 1.5 t imes the vent area. Equat ion 6-6 is used to calculate a correction, M, for file l imited inlet air openings:

M = [1 + (Av/Ai) 2 (To /T) ] 1 /2

M = [1+(1/1.5) 2(294/853)] 1/2 = 1.07

The corrected actual vent area is:

1 .07• 16.5 = 17 .66m 2

Distributed a m o n g tile 16 vent locations, tile actual area per vent is:

2 17.66/16 = 1.10 m

The neares t commercial ven t size equal to or larger than this un i t vent area would be selected.

Equat ion 6-17 is used to check for Qfeasiblo where H = 9.1 - 0.5 = 8.6 m and d = 6.1 m

Qfeasible = 229,265 kW -~ 230 MW

Tiais value is h igher than the projected hea t release rate, 100 MW, and by itself is no t of direct concern (see 6-1.5.2).

Increased Height of Smoke Interface

Inspection of equat ion 6-3 indicates tha t the larger the he igh t of the smoke interface above rile base .of the fire, the larger the vaqu e of mass ent ra ined in rile p lume, m _ , and eouation~5-9 indicates that the t empera tu re rise in the smok~' layer will be reduced. The calculat*onsjust comple ted for a smoke layer he igh t of 3 m above the floor may be repeated for oriler smoke layer fieighl~ in search of acceptable alternative designs. The two addit ional smoke layer heights of 6 and 7.3 m have been investigated, the latter near the m a x i m u m associated with tile m i n i m u m r e c o m m e n d e d curtain dep th for the 9 . l -m-high bui lding (see 4-3). The final results of rilese additional calculations indicate values of tempera ture rise in the smoke layer o f 253°K for the 6 m high level a n d 2 0 5 ° K for the 7.3 m high level. Al though these values of smoke layer t empera ture rise are still a little h igh compared to tile target of 164°K, riley represent a major improvement . Fur thermore , rile t empera tures are low e n o n g h so as not to represent a flashover hazard or endange r structural steel.

631

N F P A 2 0 4 M I A 9 7 R O P

Case T i m e Q (s) (l~o,v)

1 ~566 100 2 >_566 100 3 >_566 1 O0

4 530 86.8 5 530 86.8 6 530 86.8

7 348 34.4 8 348 34.4 9 348 34.4

Table D-I. Results of calculations for vent design.

D L (I~m<l H-d d AT Fluxfl m M Corr. A v (m) (m) , , (m) (m) (K) (kW/m 2 ) (kgYs) (m 2 )

7.7 15.6 3.0 2.5 6.1 557 29.7 62.8 1.07 17.6 7.7 15.6 6.0 5.5 3.1 253 5.1 137.8 1.11 53.8 7.7 15.6 7.3 6.8 1.8 205 3.5 170.4 1.12 89.2

7.2 14.9 3.0 2.5 6.1 531 26.4 57.2 1.08 16.1 7.2 14.9 6.0 5.5 3.1 241 4.7 125.9 1.12 49.7 7.2 14.9 7.3 6.8 1.8 195 3.3 155.7 1.13 82.6

4.5 10.7 3.0 2.5 6.1 383 11.8 31.4 1.09 8.6 4.5 10.7 6.0 5.5 3.1 174 2.7 69.0 1.13 28.3 4.5 10.7 7.3 6.8 1.8 141 2.0 85.3 1.14 47.8

The calculations for the three smoke layer heights at die maximum heat release rate are summarized in Table D-l, entered ,as Cases 1-3. In the ~able, Hf represents the height of die ceiling above the floor; Hf-d is the height of the smoke interface above d~e floor; H - d is die height of the smoke interface above file base of the fire. In cases 1- 3, the radiant heat flux at floor level, Fluxfl, is seen to decrease to 5.1 mad 3.5 kW/m 2 ,xs the smoke interface is raised, but still remains above 2.5 kW/m2. The total required vent area (Corrected Av) incre;Lses sharply ,xs the smoke layer interface is raised. For file largest interface heigltt, the total vent area of 89.2 m2 corresponds to an area per vent of 89.2/16 = 5.57 m2, which is ~till sma l l~ than fl~e maximum vent area discussed in 3-4(a), i.e., 2d- = 2 • 1.8- = 6.48 m2.

Growing Fire

Cases 4-6 in Table D-I correspond to the growing fire with detection at 230 seconds using heat detectors. The state of the fire is represented at a time 300 seconds following detection with heat detectors, i.e., at 930 + 300 = 530 seconds. It is ,assumed that die 16 vents are all operated togedler at the alarm of the first heat detector, alternatively, the vents are actuated individually with fusible links of the same RTI and activation temperature ,as the heat detectors, for which it may be confirmed with DETAG'I'-QS that all vents open prior to 530 seconds. The calculations are parallel to Cases 1-3, except that the fire is slightly smaller, ms determined from:

Q = 0.36 (t- 39) 2 = 0.36 (530- 39) 2 = 86,800 kW

In (21ses 476, the smoke layer temperatures (AT) arid radiant fltlxes to the floor are only slighdy reduced front the corresponding steady fire situations, Cases I-3. Also, there is little change in die required ve n t areas.

(2Lses 7-9 in Table 1-)-1 correspond to the growing fire, with detection at 48 seconds using smoke detectors. Again, the state of the fire is represented at a time 300 seconds from detection, Le., at 348 seconds. It is :Lssmned that die 16 vents are operated together at the alarm of the first smoke detector. The calcukttions are executed at a state of fire development from:

9 = Q = 0.36 (t- 39)- = 0.36 (348- 39) 2 34,400 kW

It is seen that C:~e 9 meets the design objective of heat fluxes to the floor that are ~=dculmed ;Ls being lower than 2.5 kW/m2, :rod Case 8 nearly does so. The required vent are,x~ are 28.3 m 2 a n d 47.8 m2 for C;Lses 8 and 9, resl)ectively, corresponding to unit vent areas (16 vents) of 1.8 and 2~,.0 In2, h o d / o f which are well below their respective maxima, 2d 2, I)n.sed on 3-4(a).

It will be noted the (~k~se 8 solutiorJ using "hand calculations" provides a close, somewhat couserwative approximation of die LAVENT predictions, which are summarized below.

LAVENT Analysls

The Table 1-)-1, (2ase 8 vent design will now be analyzed using the computer program LAVENT [3]. LAVENT is able to assess the time- ~,,u'ying events associated with the predicted fire. The fire has been previously determined as follows:

Q = o.18t 2 for o<t_< 134seconds Q = 0.36 (t- 39)2 for 134 < t-< 566 seconds Q = 100,000 kW for t > 566 seconds

The values for the above-described fire will be used as input for LAVENT. The fire is ,x~sumed to start in the center of the building.

A complete smoke detection system is to be installed with detectors spaced 9.1 m on center. Detectors are located a maximum of 6.5 m from the fire axis, i.e., one-half the diagonal distance between "detectors. As noted in 6-1.4.7.2.2, detectors have an activation temperature of 31°C (10°C above ambient), and are located 0.1m below the ceiling.

The vent design will use sixteen 1.76-m2 vents located 18.3 meters on center. All vents automatically open upon activation of the first smoke detector.

LAVENT predicts the upper layer temperature will be 377°C and the upper "hot" layer will be 4.6 m above floor level at 600 seconds. A 3-m clear layer is maintained throughout the 600-second time interval. However, heat flux at floor level is projected to be approximately 10 kW/m2 at 600 seconds, and file desitzn objective of limiting heat flux to 2.5 kW/m2 at floor level is exceeded. At 342 seconds, the time of detection plus 300 seconds, however, the design objectives are met. At 360 seconds LAVENT predicts the upper layer temperature as 444°K (171°C), with the layer being 7.3 m above the floor. The predicted 1500K temperature rise is limited to less than the target value of ] 64°K, and heat flux at floor level is predicted to be 2.2 ~W/m2. Therefore, the design objectives are satisfied for a time interval greater than the time of detection plus 300 seconds.

Inlet air is 1.5 times the vent area. To maintain the vent flow predicted by LAVENT, inlet air net free area should be maintained at a minimum of twice the open vent area. Although the net free inlet air area is less than required, the inlet area is sufficiendy large dlat LAVENT predictions may be assumed to be reasonably valid. However, consideration should be ~iven to increasing the vent area to account for die restrictions in inlet air.

See Figures D-4 through D-11 and Table D-2.

650

600

550

50O

~. 450 E

,,J

350

300

2% 150 300 450

Time (s)

Figure D-4 Temperature.

600

632

N F P A 204M - - A97 R O P

J r -

. J

9.5

9.0

8.5

8.0

7.5

6.5

6.0

5.5

5.0

4.5 1 50 300 450 Time (s)

Figure D-5 Layer height.

600

30

28

26

24

22

20

~ 18 2 ~ 16

12

10

8

61 f 4

2

00 150 300 450 Time (s)

F'tgure D-7 Vent area.

600

0.10E+09

0.90E+08

0.80E+08

0.70E+08

~- 0 . 6 0 E + ~

0 .~ 0.50E+OO LI,.

0.40E+08 /

0.30E+08

0.10E+08

o.oo o 150 300 Time Is)

Plgure D-6 F}re output.

450 600

A

- J

13000

12000

1100o

10000

90oo

8000

7o00

6ooo

50oo

40oo

3oo0

0 o 150 300 450 -nine (s)

Figure D-.8 Layer mass.

600

633

N F P A 2 0 4 M m A97 R O P

a .

v , .c . , J

120-

110 •

100

90

7O

60

4O

3O

2O

10

0 o

1050-

1000

950

9OO

850

8O0

750

700

650

600

550

500

450

400

350

300

2500

150 300 450 Tm~e (s)

Figure D-9 Plume flow.

150 300 450 Time (s)

600

,,¢

, . J

1050 -

1000

95O

900

85O

8OO

750

=E 61111

55O

350

25O o 150 300 450 Time (s)

F'qgure D-I 1 Jet temperature.

6OO

Figure D-10 Detector temperature.

6~4

N F P A 2 0 4 M - - A 9 7 R O P

Table D-2

CEILING H E I G H T =

R O O M L E N G T H =

R O O M W I D T H =

CURTAIN I_~NGTH =

CU RTAIN H E I G H T =

MATERIAL =

9 . 1 M

73.0 M

73.0 M

292.0 M

0.0 M

INSULATED DECK (SOLID POLYSTYRENE)

CEILING C O N D U C T I V r I ' Y = .149E+00 W / M K

CEILIING DENSITY = .116E+04 K G / M 3

CEILING HEAT CdkPACITY = . 1 0 5 E + 0 4 J / M K

CEIL)[NG THICKNES, S = .152E+00 M

FIRE H E I G H T = 0.5-M

FIRE P O W E R / A R E A = 0.2136E+07 W / M 2

LINK NO = 1 RADIUS = 6.5 M DIST CEILING = 0.1 M

RTI= 1 .00SQRT(MS) FUSION TEMPERATURE F O R LINK = 304.00 V E N T = 1

VENTAREA= 28.2 M2 L I N K C O N T R O I J J N G V E N T = 1

TIME; (S)--- 0 . 0 0 0 0 L Y R T E M P (K)= 2 9 4 . 0 L Y R H T (M) = 9.10

LYR MASS (KG)=0. 000E+00 FIRE O U T P U T (W) = 0.0000E+00 VENT AREA (M2) = 0.00

LINK = 1 LINK TEMP (K) = 294 .00JET VELOCrI 'Y ( M / S ) = O.O00JET TEMP (K) = 294.0

R (M) = 0.00 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T ( W / M 2 ) = 0.000E+00

R (M) = 1.74 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 3.48 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 5.22 TSL (K) = 294.0 QB 0 N / M 2 ) = 0.000E+00 Q T

R (m) = 6.95 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 8.69 TSL (g) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 10.43 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 12.17 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 13.91 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 15.65 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 17.39 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 19.12 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 QT

R (M) = 20.86 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 22.60 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 24 .34TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 26.08 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 27.82 TSL (K) = 294,0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 29.56 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 31.29 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 33.03 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 34.77 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 36.51 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 38.25 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 39.99 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 41.73 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 43.46 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 45.20 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 QT

R (M) = 46.94 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

R (M) = 48.68 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) - - 0.000E+00

( W / M 2 ) = 0.000E+00

R (M) = 50.42 TSL (K) = 294.0 QB ( W / M 2 ) = 0.000E+00 Q T ( W / M 2 ) = 0.000E+00

TIME (S)= 60.0000 LYRTEMP (K)= 3 0 1 . 4 L Y R H T (M) = 8.99

LYR MAKS (KG)=0.657E+03 FIRE O U T P U T (W) = 0.6480E+06 VENT AREA (M2) = 28.20

L I N K = 1 L I N K T E M P (K) = 309 .95JETVELOCITY (M/S) = 1.104

6S5

N F P A 2 0 4 M - - A 9 7 R O P

J E T T E M P (K) = 310.2

R (M) = 0.00 TSL (K)

TIME LINK 1 OPENS EQUALS 41.7098 (S)

= 302.1 QB ( W / M 2 ) = 0.834E+03 QT ( W / M 2 ) = 0.000E+00

R (M) = 1.74 TSL (K) = 299.5 QB ( W / M 2 ) = 0.587E+03 QT

R (M) = 3.48 YSL (K) = 297.8 QB ( W / M 2 ) = 0.417E+03 QT

R (M) = 5.22 TSL (K) = 296.6 QB ( W / M 2 ) = 0.287E+03 Q T

R (M) = 6.95 TSL (K) = 295.8 QB ( W / M 2 ) = 0.205E+03 QT

R (M) = 8.69 TSL (K) = 295.4 QB ( W / M 2 ) = 0.153E+03 Q T

R (M) = 10.43 TSL (K) = 295.0 QB ( W / M 2 ) = 0.117E+03 Q T

R (M) = 12.17 TSL (K) = 294.8 QB ( W / M 2 ) = 0.925E+02 Q T

R (M) = 13.91 TSL (K) = 294.7 QB ( W / M 2 ) = 0.748E+02 Q T

R (M) = 15.65 TSL (K) = 294.6 QB ( W / M 2 ) = 0.619E+02 Q T

R (M) = 17.39 TSL (K) = 294.5 QB ( W / M 2 ) = 0.522E+02 Q T

R (M) = 19.12 TSL (K) = 294.4 QB ( W / M 2 ) = 0.448E+02 Q T

R (M) = 20.86 TSL (K) = 294.3 QB ( W / M 2 ) = 0.389E+02 Q T

R (M) = 22.60 TSL (K) = 294.3 QB ( W / M 2 ) = 0.343E+02 Q T

R (M) = 24.34 TSL (K) = 294.3 QB ( W / M 2 ) = 0.305E+02 Q T

R (M) = 26.08 TSL (K) = 294.2 QB ( W / M 2 ) = 0.274E+02 Q T

R (M) = 27.82 TSL (K) = 294.2 QB ( W / M 2 ) = 0.248E+02 Q T

R (M) = 29.56 TSL (K) = 294.2 QB ( W / M 2 ) = 0.226E+02 Q T

R (M) = :~1.29 TSL (K) = 294.2 QB ( W / M 2 ) = 0.207E+02 Q T

R (M) = 3 3 . 0 3 T S L (K) = 294.2 QB ( W / M 2 ) = 0.191E+02 Q T

R (M) = 34.77 TSL (K) = 294.2 QB ( W / M 2 ) = 0.177E+02 Q T

R (M) = 36.51 TSL (K) = 294.1 QB ( W / M 2 ) = 0.165E+02 Q T

R (M) = 38.25 TSL (K) = 294.1 QB ( W / M 2 ) = 0.154E+02 Q T

R (M) = 39.q9 TSL (K) = 294.1 QB ( W / M 2 ) = 0.144E+02 Q T

R (M) = 41.73 TSL (K) = 294.1 QB ( W / M 2 ) = 0.136E+02 Q T

R (M) = 43.46 TSL (K) = 294.1 QB ( W / M 2 ) = 0.128E+02 Q T

R (M) = 4 5 . 2 0 T S L (K) = 294.1 QB ( W / M 2 ) = 0.121E+02 Q T

R (M) = 46.94 TSL (K) = 294.1 QB ( W / M 2 ) = 0.115E+02 Q T

R (M) = 48.68 TSL (K) = 294.0 QB ( W / M 2 ) = 0.122E+01 Q T

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

R (M) = 50.42 TSL (K) = 294.0 QB ( W / M 2 ) = 0.110E+01 Q T ( W / M 2 ) = 0.000E+00

TIME (S)= 120.0000 LYRTEMP (K)= 317.2 L Y R H T (M) = 8.83

LYR MASS (KG)=0.162E+04 FIRE O U T P U T (W) = 0.2743E+07 VENT AREA (M2) = 28.20

LINK = 1 LINK TEMP (K) = 339 .83JET V E L O C r I Y ( M / S ) = 1.761

J E T TEMP (K) = 340.2 TIME LINK 1 OPENS EQUALS 41.7098 (S)

R (M) = 0.00 TSL (K) = 332.0 QB

R (M) = 1.74 TSL (K) = 322.4 QB

R ( M ) = 3 . 4 8 T S L (K) = 314.9 QB

R (M) = 5.22 TSL (K) = 308.8 QB

R (M) = 6.95 TSL (K) = 304.7 QB

R ( M ) = 8 . 6 9 T S L ( K ) = 3 0 2 . 1 Q B

R (M) = 10 .43TSL (K) = 300.2 QB

R (M) = 12 .17TSL (K) = 298.9 QB

R ( M ) = 1 3 . 9 1 T S L ( K ) = 2 9 8 . 0 Q B

R ( M ) = 1 5 . 6 5 T S L ( K ) = 2 9 7 . 3 Q B

R ( M ) = 1 7 . 3 9 T S L ( K ) = 2 9 6 . 8 Q B

R ( M ) = 19.12 TSL (K) = 2 9 6 . 4 Q B

R ( M ) = 2 0 . 8 6 T S L ( K ) = 2 9 6 . 1 Q B

R ( M ) = 2 2 . 6 0 T S L ( K ) = 2 9 5 . 8 Q B

R (M) = 24..'+4 TSL (K) = 295.6 QB

R ( M ) = 2 6 . 0 8 T S L ( K ) = 2 9 5 . 5 Q B

R ( M ) = 2 7 . 8 2 T S L ( K ) = 2 9 5 . 3 Q B

R ( M ) = 29.56 TSL (K) = 2 9 5 . 2 Q B

R ( M ) = 3 1 . 2 9 T S L ( K ) = 2 9 5 . 1 Q B

( W / M 2 ) = 0.242E+04 Q T

( W / M 2 ) = 0.188E+04 Q T

( W / M 2 ) = 0.142E+04 Q T

( W / M 2 ) = 0.102E+04 Q T

( W / M 2 ) = 0.753E+03 Q T

( W / M 2 ) = 0.569E+03 Q T

( W / M 2 ) = 0.441E+03 Q T

( W / M 2 ) = 0.350E+03 Q T

( W / M 2 ) = 0.285E+03 Q T

( W / M 2 ) = 0.236E+03 Q T

( W / M 2 ) = 0.199E+03 Q T

( W / M 2 ) = 0.171E+03 Q T

( W / M 2 ) = 0.149E+03 Q T

( W / M 2 ) = 0.131E+03 Q T

( W / M 2 ) = 0.117E+03 QT

( W / M 2 ) = 0.105E+03 Q T

( W / M 2 ) = 0.951E+02 Q T

( W / M 2 ) = 0.867E+02 Q T

( W / M 2 ) = 0.795E+02 Q T

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

( W / M 2 ) = 0.000E+00

636

N F P A 2 0 4 M ~ A 9 7 R O P

R (ld) = "53.03 TSL (K) = 295.0 QB ( W / M 2 ) = 0.734E+02 Q T ( W / M 2 ) = 0.000E+00

R (M) = 34.77 TSL (K) = 294.9 QB ( W / M 2 ) = 0.680E+02 Q T ( W / M 2 ) = 0.000E+00

R (M) = 36.51 TSL (K) = 294.9 QB ( W / M 2 ) = 0.633E+02 Q T ( W / M 2 ) = 0.000E+00

R (M) = 38.25 TSL (K) = 294.8 QB ( W / M 2 ) = 0.592E+02 QT ( W / M 2 ) = 0.000E+00

R (iYl) = 39.99 TSL (K) = 294.8 QB ( W / M 2 ) = 0.555E+02 Q T ( W / M 2 ) = 0.000E+00

R (M) = 41.73 TSL (K) = 294.7 QB ( W / M 2 ) = 0.522E+02 Q T ( W / M 2 ) = 0.000E+00

R (M) = 4 3 . 4 6 T S L (K) = 294.7 QB ( W / M 2 ) = 0.492E+02 Q T ( W / M 2 ) = 0.000E+00

R (M) = 45.20 TSL (K) = 294,6 QB ( W / M 2 ) = 0.466E+02 Q T ( W / M 2 ) = 0.000E+00

R (M) = 46.94 TSL (K) = 294.6 QB ( W / M 2 ) = 0.442E+02 Q T ( W / M 2 ) = 0.000E+00

R (M) = 48.68 TSL (K) = 294.1 QB ( W / M 2 ) = 0.504E+01 Q T ( W / M 2 ) = 0.000E+00

R (M) = 50.42 TSL (K) = 294.1 QB ( W / M 2 ) = 0.455E+01 Q T ( W / M 2 ) = 0.000E+00

TIME (S)= 180.0000 LYR TEMP (K)= 339,8 L Y R H T (M) = 8.60

L'~q~ MASS (KG)=0.276E+04 FIRE O U T P U T (W) = 0.7483E+07 VENT AREA (M2) = 28.20

LINK = 1 LINK TEMP (K) = 385 .73JET V E L O C r I Y (M/S) = 2.493

J E T T E M P (K) = 386.3 TIME LINK 1 OPENS EQUALS 41.7098 (S)

R (M) = 0.00 TSL (K) = 386.4 QB ( W / M 2 ) = 0.514E+04 Q T ( W / M 2 ) = 0.000E+00

R (M) = 1.74 TSL (K) = 367.0 QB ( W / M 2 ) = 0.421E+04 QT ( W / M 2 ) = 0.000E+00

R (M) = 3.48 TSL (K) = 349.7 QB ( W / M 2 ) = 0.329E+04 Q T ( W / M 2 ) = 0.000E+00

R (M) = 5.22 TSL (K) = 334.5 QB ( W / M 2 ) = 0.244E+04 Q T ( W / M 2 ) = 0.000E+00

R (M) = 6.95 TSL (K) = 324.0 QB ( W / M 2 ) = 0.183E+04 Q T ( W / M 2 ) = 0.000E+00

R (M) = 8.69 TSL (K) = 316.7 QB ( W / M 2 ) = 0.140E+04 Q T ( W / M 2 ) = 0.000E+00

R ( M ) = 1 0 . 4 3 T S L ( K ) = 311.6QB(W/M2)=O.IO9E+O4QT(W/M2)= 0.000E+00

R I M ) = 12.17 TSL (K) = 308.0 QB ( W / M 2 ) = 0.864E+03 Q T ( W / M 2 ) = 0.000E+00

R I M ) = 13.91 TSL (K) = 305.3 QB ( W / M 2 ) = 0.702E+03 Q T ( W / M 2 ) = 0.000E+00

R qM) = 15.65 TSL (K) -- 303.4 QB ( W / M 2 ) = 0.582E+03 QT ( W / M 2 ) = 0.000E+00

R (M) = 17.39 TSL (K) = 301.9 QB ( W / M 2 ) = 0.491E+03 QT ( W / M 2 ) = 0.000E+00

R (M) = 19.12 TSL (K) = 300.8 QB ( W / M 2 ) = 0.420E+03 Q T ( W / M 2 ) = 0.000E+00

R (M) = 20.86 TSL (K) = 299.9 QB ( W / M 2 ) = 0.365E+03 Q T ( W / M 2 ) = 0.000E+00

R ~IM) = 22.60 TSL (K) = 299.2 QB ( W / M 2 ) = 0.321E+03 Q T ( W / M 2 ) = ff000E+00

R (M) = 24.34 TSL (K) = 298.6 QB ( W / M 2 ) = 0.286E+03 Q T ( W / M 2 ) = 0.000E+00

R (M) = 26.08 TSL (K) = 298.1 QB ( W / M 2 ) = 0.256E+03 Q T ( W / M 2 ) = 0.000E+00

R (M) = 27.82 TSL (K) = 297.7 QB ( W / M 2 ) = 0.232E+03 Q T ( W / M 2 ) = 0.000E+00

R (M) = 29.56 TSL (K) = 297.4 QB ( W / M 2 ) = 0.211E+03 Q T ( W / M 2 ) = 0.000E+00

R (m) = 31.29 TSL (K) = 297.1 QB ( W / M 2 ) = 0.193E+03 Q T ( W / M 2 ) = 0.000E+00

R (M) = 33.03 TSL (K) = 296.9 QB ( W / M 2 ) = 0.178E+03 Q T ( W / M 2 ) = 0.000E+00

R (M) = 34.77 TSL (K) = 296.7 QB ( W / M 2 ) = 0.165E+03 Q T ( W / M 2 ) = 0.000E+00

R (M) = 36.51 TSL (K) = 296.5 QB ( W / M 2 ) = 0.154E+03 Q T ( W / M 2 ) = 0.000E+00

R (M) = 38,25 TSL (K) = 296.3 QB ( W / M 2 ) = 0.143E+03 QT ( W / M 2 ) = 0.000E+00

R (M) = 39.99 TSL (K) = 296.2 QB ( W / M 2 ) = 0.134E+03 Q T ( W / M 2 ) = 0.000E+00

R (M) = 41.73 TSL (K) = 296.0 QB ( W / M 2 ) = 0.126E+03 Q T ( W / M 2 ) = 0.000E+00

R (M) = 43.46 TSL (K) = 295.9 QB ( W / M 2 ) = 0.I19E+03 Q T ( W / M 2 ) = 0.000E+00

R (M) = 45.20 TSL (K) = 295.8 QB ( W / M 2 ) = 0.113E+03 Q T ( W / M 2 ) = 0.000E+00

R (M) = 46.94 TSL (K) = 295.7 QB ( W / M 2 ) = 0.107E+03 Q T ( W / M 2 ) = 0.000E+00

R (M) = 48.68 TSL (K) = 294.2 QB ( W / M 2 ) = 0.136E+02 Q T ( W / M 2 ) = 0.000E+00

R (M) = 50.42 TSL (K) = 294.2 QB ( W / M 2 ) = 0.123E+02 Q T ( W / M 2 ) = 0.000E+00

TIME (S)= 240.0000 LYR TEMP (K)= 371.5 LYR H T (M) = 8.28

LYR MASS (KG)=0.414E+04 FIRE O U T P U T (W) = 0.1541E+08 VENT AREA (M2) = 28.20

LINK= 1 L I N K T E M P (K) = 4 4 7 . 5 7 J E T V E L O C r I Y (M/S) = 3.186

J E T TEMP (K) = 448.2 TIME LINK 1 OPENS EQUALS 41.7098 (S)

R (M) =

R (M) =

R (M) =

R (M) =

R (M) =

0.00 TSL (K) = 469.7 QB ( W / M 2 ) = 0.816E+04 QT ( W / M 2 ) = 0.000E+00

1.74 TSL (K) = 439.3 QB ( W / M 2 ) = 0.700E+04 Q T ( W / M 2 ) = 0.000E+00

3.48 TSL (K) = 408.8 QB ( W / M 2 ) = 0.570E+04 Q T ( W / M 2 ) = 0.000E+00

5.22 TSL (K) = 380.2 QB ( W / M 2 ) = 0.439E+04 Q T ( W / M 2 ) = 0.000E+00

6,95 TSL (K) = 359.0 QB ( W / M 2 ) = 0.335E+04 Q T ( W / M 2 ) = 0.000E+00

637

N F P A 2 0 4 M - - A 9 7 R O P

R (M) = 8.69 TSL (K) = R ( M ) = 10.43TSL(K)= R(M)= 12.17TSL(K)= R ( M ) = 13.91TSL(K)= R ( M ) = 15.65TSL(K)=

R ( M ) = 17.39TSL(K)=

R ( M ) = 19.12TSL(K)= R ( M ) = 20.86TSL(K)= R ( M ) = 22.60TSL(K)= R (M) = 24.34TSL (K) = R ( M ) = 26.08TSL(K)=

R ( M ) = 27.82TSL(K)= R ( M ) = 29.56TSL(K)= R ( M ) = 31.29TSL(K)=

R ( M ) = 33.03TSL(K)= R ( M ) = 34.77TSL(K)= R(M)= 36.51TSL(K)=

R ( M ) = 38.25TSL(K)= R ( M ) = 3iL99TSL(K)= R ( M ) = 41.73TSL(K)=

R ( M ) = 43.46TSL(K)= R ( M ) = 45.20TSL(K)= R(M)= 46.94TSL(K)= R(M)= 48.68TSL(K)= R(M)= 50.42TSL(K)=

343,8 QB (W/M2) = 0.259E+04 QT (W/M2) = 0.000E+00 332.8 QB (W/M2) = 0.203E+04 QT (W/M2) = 0.000E+00 324.9 QB (W/M2) = 0.162E+04 QT (W/M2) = 0.000E+00 319.1 QB (W/M2) = 0.132E+04 QT (W/M2) = 0.000E+00 314.8 QB (W/M2) = 0.109E+04 QT (W/M2) = 0.000E+00

311.6 QB (W/M2) = 0.922E+03 QT (W/M2) = 0.000E+00 309.1 QB (W/M2) = 0.790E+03 QT (W/M2)'= 0.000E+00 307.1 QB (W/M2) = 0.687E+03 QT (W/M2) = 0.000E+00 305.5 QB (W/M2) = 0.604E+03 QT (W/M2) = 0.000E+00

304.2 QB (W/M2) = 0.536E+03 QT (W/M2) = 0.000E+00 303.2 QB (W/M2) = 0.481E+03 QT (W/M2) = 0.000E+00 302.3 QB (W/M2) = 0.435E+03 QT (W/M2) = 0.000E+00 301.6 QB (W/M2) = 0.396E+03 QT (W/M2) = 0.000E+00

300.9 QB (W/M2) -- 0.363E+03 QT (W/M2) = 0.000E+00 300.4 QB (W/M2) = 0.334E+03 QT (W/M2) = 0.000E+00 299.9 QB (W/M2) = 0.309E+03 QT (W/M2) = 0.000E+00

299.5 QB (W/M2) = 0,288E+03 QT (W/M2) = 0.000E+00 299.1 QB (W/M2) = 0.269E+03 QT (W/M2) = 0.000E+00 298.8 QB (W/M2) = 0.252E+03 QT (W/M2) = 0.000E+00

298.5 QB (W/M2) = 0.237E+03 QT (W/M2) = 0.000E+00 298.3 QB (W/M2) = 0.223E+03 QT (W/M2) = 0.000E+00 298.0 QB (W/M2) = 0,211E+03 QT (W/M2) = 0.000E+00 297.8 QB (W/M2) = 0,200E+03 QT (W/M2) = 0.000E+00 296.6 QB (W/M2) = 0.198E+03 QT (W/M2) = 0.000E+00 294.5 QB (W/M2) = 0.250E+02 QT (W/M2) = 0.000E+00

TIME (S)= 300.0000 LYR TEMP (K)= 406.7 LYR HT (M) = 7.86 LYR MASS (KG)=0.575E+04 FIRE OUTPUT (W) = 0.2452E+08 VENT AREA (M2) = 28.20

LINK = 1 LINK TEMP (K) = 511.85JET VELOCITY (M/S) = 3.699

JETTEMP (K) = 512.4 TIME LINK 1 OPENS EQUALS 41.7098 (S) R (M) = 0.00 TSL (K) = 561.4 QB (W/M2) = 0.962E+04 QT (W/M2) =-0.297E-11

R (M) =

R (M) =

R (M) = R (M) =

R (M) =

R (M) =

R (M) =

R (M) =

R (M) =

R (M) =

R (M) =

R (M) =

R (M) =

R (M) = R (M) =

R (M) =

R (M) =

R (M) =

R(M)= R (M) = R (M) =

R (M) =

R (M) =

R (M) =

1.74 TSL (K) = 523.2 QB (W/M2) = 0.859E+04 QT (W/M2) =-0.297E-11

3.48 TSL (K) = 481.7 QB (W/M2) = 0.731E+04 QT (W/M2) = -0.297E-11 5.22 TSL (K) = 439.7 QB (W/M2) = 0.588E+04 QT (W/M2) =-0.297E-11 6.95 TSL (K) = 406.1 QB (W/M2) = 0.464E+04 QT (W/M2) =-0.297E-11

8.69 TSL (K) = ,'481.0 QB (W/M2) = 0.365E+04 QT (W/M2) = -0.297E,-11 10.43 TSL (K) = 362.4 QB (W/M2) = 0.289E+04 QT (W/M2) = -0.297E-11 12.17 TSL (K) 13,91 TSL (K)

15.65 TSL (K) 17.39 TSL (K)

19.12 TSL (K) 20.86 TSL (K)

22.60 TSL (K) 24.34 TSL (K) 26.08 TSL (K) 27.82 TSL (K) 29.56 TSL (K) 31.29 TSL (K) 33.03 TSL (K) 34.77 TSL (K)

36.51 TSL (K) 38.25 TSL (K) 39.99 TSL (K) 41.73 TSL (K)

= 348.8 QB (W/M2) = 0.234E+04 QT (W/M2) =-0.297E-11 = 338.7 QB (W/M2) = 0.191E+04 QT (W/M2) =-0.297E-11 = 331.1 QB (W/M2) = 0.159E+04 QT (W/M2) = -0.297E-11

= 325.4 QB (W/M2) = 0.135E+04 QT (W/M2) = -0.297E-11 = 320.9 QB (W/M2) = 0.116E+04 QT (W/M2) = -0.297E-11 = 317.4 QB (W/M2) = 0.101E+04 QT (W/M2) =-0.297E-11

= 314.6 QB (W/M2) = 0.887E+03 QT (W/M2) = -0.297E-11

= 312.3 QB (W/M2) = 0.789E+03 QT (W/M2) = -0.297E-11 = 310.4 QB (W/M2) = 0.708E+03 QT (W/M2) = -0.297E-11 = 308.8 QB (W/M2) = 0.640E+03 QT (W/M2) = -0.297E-11 = 307.5 QB (W/M2) = 0.583E+03 QT (W/M2) = -0.297E-11 = 306.4 QB (W/M2) = 0.535E+03 QT (W/M2) = -0.297E-11 = 305.4 QB (W/M2) = 0.493E+03 QT (W/M2) = -0.297E-11 = 304.6 QB (W/M2) = 0.456E+03 QT (W/M2) =-0.297E-11 = 303.8 QB (W/M2) = 0.425E+03 QT (W/M2) =-0.297E-11

= 303.2 QB (W/M2) = 0.397E+03 QT (W/M2) = -0.297E-11 = 302.6 QB (W/M2) = 0.372E+03 QT (W/M2) =-0.297E-11 = 302.1 QB (W/M2) = 0.350E+03 QT (W/M2) = -0.297E-11

638

N F P A 2 0 4 M - - A 9 7 R O P

R (M) =, 43.46 TSL (K) = 301.6 QB (W/M2) = 0.330E+03 QT (W/M2) =-0.297E-11

R (M) = 45.20 TSL (K) = 301.2 QB (W/M2) = 0.312E+03 QT (W/M2) = -0.297E-11

R (M) = 46.94 TSL (K) = 300.8 QB (W/M2) = 0.296E+03 QT (W/M2) =-0.297E-11

R (M) = 48.68 TSL (K) = 299.8 QB (W/M2) = 0.286E+03 QT (W/M2) = -0,297E-11

R (M) = 50.42 TSL (K) = 294.9 QB (W/M2) = 0.390E+02 QT (W/M2) =-0.297E-11

q]ME (S)= 360,0000 LYR TEMP (K)= 443.6 LYR HT (M) = 7,31

LYR MASS (KG)=0.760E+04 FIRE OUTPUT (W) = 0.3795E+08 VENT AREA (M2) = 28.20

[,INK= 1 LINKTEMP (K) --- 590.31JETVELOCITY (M/S) = 4.317

JET TEMP (K) = 590.9 TIME LINK 1 OPENS EQUALS 41.7098 (S)

R (M) = 0.00 TSL (K) = 658.1 QB (W/M2) = 0.117E+05 QT (W/M2) = -0.297E-11

R (M) = 1.74 TSL (K) = 614.7 QB (W/M2) = 0,107E+05 QT (W/M2) =-0.297E-11

3.48 TSL (K) = 564.3 QB (W/M2) = 0.939E+04 QT (W/M2) = -0.297E-11

5.22 TSL (K) -- 510,0 QB (W/M2) = 0.780E+04 QT (W/M2) =-0.297E-11

6.95 TSL (K) = 463.8 QB (W/M2) = 0.631E+04 QT (W/M2) = -0.297E-11

8.69 TSL (K) = 427.5 QB (W/M2) = 0.505E+04 QT (W/M2) =-0.297E-11

v, ( M ) =

tt ( M ) =

R (M) =

It (M) =

R (M) = 10.43 TSL (K) = 399.9 QB (W/M2) = 0.405E+04 QT (W/M2) =-0.297E-11

R (M) = 12.17 TSL (K) = 379.3 QB (W/M2) = 0.329E+04 QT (W/M2) =-0.297E-11

R (M) = 13.91 TSL (K) = 363.9 QB (W/M2) = 0.271E+04 QT (W/M2) =-0.297E-11

R (M) = 15.65 TSL (K) = 352.2 QB (W/M2) = 0.226E+04 QT (W/M2) =-0,297E-11

R (M) = 17.39 TSL (K) = 343.2 QB (W/M2) = 0.192E+04 QT (W/M2) =-0.297E-11

R (M) = 19.12 TSL (K) = 336.2 QB (W/M2) = 0.165E+04 QT (W/M2) =-0.297E-11

R (M) = 20.86 TSL (K) = 330.7 QB (W/M2) = 0.143E+04 QT (W/M2) = -0.297E-11

R (M) = 22.60 TSL (K) = 326.3 QB (W/M2) = 0,126E+04 QT (W/M2) =-0.297E-11

R (M) = 24.34TSL (K) = 322.7 QB (W/M2) = 01112E+04 QT (W/M2) =-0.297E-11

R (M) = 26.08 TSL (K) = 319.8 QB (W/M2) = 0.101E+04 QT (W/M2) =-0,297E-11

R (M) = 27.82 TSL (K) = 317.3 QB (W/M2) = 0.910E+03 QT (W/M2) =-0.297E-11

R (M) = 29.56 TSL (K) = 315.2 QB (W/M2) = 0.828E+03 QT (W/M2) =-0.297E-11

R (M) = 31.29 TSL (K) = 313.4 QB (W/M2) = 0.759E+03 QT (W/M2) =-0.297E-11

R (M) -- 33.03 TSL (K) = 311.9 QB (W/M2) = 0.699E+03 QT (W/M2) =-0.297E-11

R (M) = 34.77 TSL (K) = 310.6 QB (W/M2) = 0.647E+03 QT (W/M2) =-0.297E-11

R (M) = 36.51 TSL (K) = 309.4 QB (W/M2) = 0.602E+03 QT (W/M2) =-0.297E-11

R (M) = 38.25 TSL (K) = 308.4 QB (W/M2) = 0.562E+03 QT (W/M2) =-0,297E-11

R (M) = 39.99 TSL (K) = 307.5 QB (W/M2) = 0.527E+03 QT (W/M2) =-0.297E-11

R (M) = 41.73 TSL (K) = 306.7 QB (W/M2) = 0.495E+03 QT (W/M2) =-0.297E-11

R (M) = 43.46 TSL (K) = 306.0 QB (W/M2) = 0.467E+03 QT (W/M2) =-0.297E-11

R (M) = 45.20 TSL (K) = 305.3 QB (W/M2) = 0,442E+03 QT (W/M2) =-0.297E-11

R (M) = 46.94 TSL (K) = 304.7 QB (W/M2) = 0.419E+03 QT (W/M2) =-0.297E-11

R (M) = 48.68 TSL (K) = 303.7 QB (W/M2) = 0.402E+03 QT (W/M2) =-0.297E-11

R (M) = 50.42 TSL (K) = 295.4 QB (W/M2) = 0,597E+02 QT (W/M2) =-0.297E-11

TIME (S)= 420.0000 LYRTEMP (K)= 483.7 LYRHT (M) = 6.66

LYR MASS (KG)=0.949E+04 FIRE OUTPUT (W) = 0.5283E+08 VENT AREA (M2) = 28.20

LINK = 1 LINK TEMP (K) = 677.18JET VELOCITY (M/S) = 4.879

,JET TEMP (K) = 677.9 TIME LINK 1 OPENS EQUALS 41.7098 (S)

R (M) = 0.00 TSL (K) = 747.8 QB (W/M2) = 0.129E+05 QT (W/M2) =-0.297E-11

R (M) = 1.74 TSL (K) = 701,8 QB (W/M2) = 0.120E+05 QT (W/M2) = -0,297E-11

R (M) = 3.48 TSL (K) = 646.0 QB (W/M2) = 0.108E+05 QT (W/M2) =-0.297E-11

R (M) = 5.22 TSL (K) = 583.0 QB (W/M2) = 0.920E+04 QT (W/M2) =-0.297E-11

R (M) = 6.95 TSL (K) = 526.3 QB (W/M2) = 0.764E+04 QT (W/M2) = -0.297E-11

R (M) = 8.69 TSL (K) = 479.6 QB (W/M2) = 0.625E+04 QT (W/M2) = -0.297E-11

R (M) = 10.43TSL (K) = 443.0 QB (W/M2) = 0.510E+04 QT (W/M2) =-0.297E-11

R (M) = 12.17TSL (K) = 414.9 QB (W/M2) = 0.419E+04 QT (W/M2) =-0.297E-11

R (M) = 13.91 TSL (K) = 393.6 QB (W/M2) -- 0.347E+04 QT (W/M2) ---0,297E-11

R (M) = 15.65 TSL (K) = 377.2 QB (W/M2) = 0,292E+04 QT (W/M2) =-0.297E-11

R (M) = 17.39 TSL (K) = 364.6 QB (W/M2) = 0.249E+04 QT (W/M2) =-0.297E-11

6.~9

N F P A 2 0 4 M ~ A 9 7 R O P

R (M) = 19.12 TSL (K) = 354.7 QB (W/M2) = 0.214E+04

R (M) = 20.86TSL (K) = 346.8 QB (W/M2) = 0.187E+04

R (M) = 22.60 TSL (K) = 340.5 QB (W/M2) = 0.165E+04

R (M) = 24.34 TSL (K) = 335.4 QB (W/M2) = 0.147E+04

R (M) = 26.08 TSL (K) = 331.1 QB (W/M2) = 0.132E+04

R (M) = 27.82 TSL (K) = 327.6 QB (W/M2) = 0.119E+04

R (M) = 29.56TSL (K) = 324.6 QB (W/M2) -- 0.108E+04

R (M) = 31.29 TSL (K) = 322.0 QB (W/M2) = 0.994E+03

R (M) = 33.03 TSL (K) = 319.8 QB (W/M2) = 0.916E+03

R (M) = 34.77 TSL (K) = 317.9 QB (W/M2) = 0.849E+03

R (M) = 36.51 TSL (K) = 316.2 QB (W/M2) = 0.790E+03

R (M) = 38.25 TSL (K) = 314.8 QB (W/M2) = 0.737E+03

R (M) = 39.99 TSL (K) = 313.5 QB (W/M2) = 0.691E+03

R (M) = 41.73 TSL (K) = 312.3 QB (W/M2) = 0.650E+03

R (M) = 43.46TSL (K) = 311.3 QB (W/M2) = 0.613E+03

R (M) = 45,20 TSL (K) = 310.3 QB (W/M2) = 0.580E+03

R (M) = 46.94 TSL (K) = 309.5 QB (W/M2) = 0.549E+03

R (M) = 48,68 TSL (K) = 308.3 QB (W/M2) = 0.525E+03

R (M) = 50.42 TSL (K) = 296.2 QB (W/M2) = 0.820E+02

QT (W/M2) = -0.297E-11

QT (W/M2) = -0.297E-11

QT (W/M2) = -0.297E-11

QT (W/M2) =-0.297E-11

QT (W/M2) = -0.297E-11

QT (W/M2) = -0.297E-I 1

QT (W/M2) =-0.297E-11

QT (W/M2) =-0.297E-11

QT (W/M2) =-0.297E-11

QT (W/M2) = -0.297E-11

QT (W/M2) =-0.297E-11

QT (W/M2) = -0.297E-11

QT (W/M2) =-0.297E-11

QT (W/M2) = -0.297E-11

QT (W/M2) =-0.297E-11

QT (W/M2) = -0.297E-11

QT (W/M2) = -0.297E-11

QT (W/M2) = -0.297E-11

QT (W/M2) =-0.297E-11

TIME (S)= 480.0000 LYR TEMP (K)= 530.8 LYR HT (M) = 5.94

LYR MA,qS (KG)=0.112E+05 FIRE OUTPUT (W) = 0.7059E+08 VENTAREA (M2) = 28.20

LINK = 1 LINKTEMP (K) = 784.41JETVELOCITY (M/S) = 5.462

JETTEMP (K) = 785.2 TIME LINK 1 OPENS EQUALS 41.7098 (S)

R (M) = 0.00 TSL (K) = 837.6 QB (W/M2) = 0.137E+05 QT (W/M2) =-0.297E-11

R (M) = 1.74 TSL (K) = 789.0 QB (W/M2) = 0.128E+05 QT (W/M2) = -0.297E-11

R (M) = 3.48 TSL (K) = 729.0 QB (W/M2) = 0.117E+05 QT (W/M2) = -0.297E-11

R (M) = 5.22 TSL (K) = 659.2 QB (W/M2) = 0.103E+05 QT (W/M2) =-0.297E-11

R (M) = 6.95 TSL (K) = 593.8 QB (W/M2) = 0.876E+04 QT (W/M2) =-0.297E-11

R (M) = 8.69 TSL (K) = 537.8 QB (W/M2) = 0.736E+04 QT (W/M2) =-0.297E-11

R (M) = 10.43 TSL (K) = 492.4 QB (W/M2) = 0.613E+04 QT (W/M2) =-0.297E-11

R (m) = t2.17 TSL (K) = 456.6 QB (W/M2) = 0.511E+04 QT (W/M2) =-0.297E-11

R (M) = 13.91 TSL (K) = 428.8 QB (W/M2) = 0.429E+04 QT (W/M2) =-0.297E-11

R (M) = 15.65 TSL (K) = 407.2 QB (W/M2) = 0.363E+04 QT (W/M2) =-0.297E-11

R (M) = 17.39 TSL (K) = 390.4 QB (W/M2) -- 0.311E+04 QT (W/M2) =-0.297E-11

R (M) = 19.12 TSL (K) = 377.0 QB (W/M2) = 0.270E+04 QT (W/M2) = -0.297E-11

R (M) = 20.86 TSL (K) -- 366.4 QB (W/M2) = 0.236E+04 QT (W/M2) =-0.297E-11

R (M) = 22.60 TSL (K) = 357.9 QB (W/M2) = 0.209E+04 QT (W/M2) = -0.297E-11

R (M) = 24.34 TSL (K) = 350.9 QB (W/M2) = 0.186E+04 QT (W/M2) =-0.297E-11

R (M) = 26.08 TSL (K) = 345.1 QB (W/M2) = 0.167E+04 QT (W/M2) =-0.297E-11

R (M) = 27.82 TSL (K) = 340.2 QB (W/M2) = 0.152E+04 QT (W/M2) =-0.297E-11

R (M) = 29.56 TSL (K) = 336.1 QB (W/M2) = 0.138E+04 QT (W/M2) =-0.297E-11

R (M) = 31.29 TSL (K) = 332.6 QB (W/M2) = 0.127E+04 QT (W/M2) ---0.297E-11

R (M) = 33.03TSL (K) = 329.6 QB (W/M2) = 0.117E+04 QT (W/M2) =-0.297E-11

R (M) = 34.77 TSL (K) = 327.0 QB (W/M2) = 0.109E+04 QT (W/M2) =-0.297E-11

R (M) = 36.51 TSL (K) = 324.7 QB (W/M2) = 0.101E+04 QT (W/M2) =-0.297E-11

R (M) = 38.25 TSL (K) = 322.7 QB (W/M2) = 0.944E+03 QT (W/M2) =-0.297E-11

R (M) = 39.99 TSL (K) = 320.9 QB (W/M2) = 0.886E+03 QT (W/M2) =-0.297E-11

R (M) = 41.73 TSL (K) = 319.3 QB (W/M2) = 0.833E+03 QT (W/M2) =-0.297E-11

R (M) = 43.46 TSL (K) = 317.8 QB (W/M2) = 0.786E+03 QT (W/M2) =-0.297E-11

R (M) = 45,20 TSL (K) = 316.5 QB (W/M2) = 0,743E+03 QT (W/M2) =-0.297E-11

R (M) = 46.94 TSL (K) = 315.4 QB (W/M2) = 0.705E+03 QT (W/M2) =-0.297E-11

R (M) = 48.68 TSL (K) = 313.9 QB (W/M2) = 0.673E+03 QT (W/M2) =-0.297E-11

R (M) = 50.42 TSL (K) = 297.1 QB (W/M2) = 0.108E+03 QT (W/M2) =-0.297E-11

TIME (S)= 540.0000 LYR TEMP (K)= 586.5 LYR HT (M) = 5.20

640

N ' t ~ A ~ - - A97 I tOP

LYR MASS (KG)f0.125E+05 FIRE OUTPUT ON) = 0.9073E+08 VENT AREA (M2) = 28.20 LrNK= 1 IJNKTEMt)(K) ffi 915,64JETVELOCrIY (M/S) = 6.041 JETTEMPCK) ffi 9.16.6 TIMELINK 10PENSEQUAI~ 41;7098(S) R (M) = 0,00 TSL (K)= 9`>1.9 Q s ( W / ~ = o.t46E+05 QT (W/M`>) ffi -0~q97E-11 R (M) = ].~74TSL (K)= 870.2 QB (W/M2) ~ 0 A ~ Q T (W/M2) --0.297E-11 , R (M) = 3:48TSL (K)= 806.7 QB ('W/M2) ~0 .1~i~05 QT 0g/M2) =-0.297E.11 R(M) ffi 5~.̀ >2 TSL (K);ffi 731.6"QB(W/M2) ffi 0.11~E~0~,QT (W/M~) ~-0.297E-11 R (M) = 0~5 TSL(K) -~ 66~0 Q}~ (w/ try) =,0.9~E+O4QT Or/M2) =,0.~97E-11 R (M) = ~'9 TSL.(k3= ~97.00~(W/M2) f ~ . ~ Q r , ~ W l M 2 ) ==O.~m_AI R 0a) = , I0.4~ TSL-tK)~= 5.44,`>QBOV/t~)= 0 , 7 0 ~ ) e 4 Q,r.(w/tm) =,o.'ts~-,.H g (M) =. 12.1~ ~ (K),~'r, o L S : ~ OVl)~)= o, e o m ~ 4 QT(WlM~) =~.29~11 R (M) = 13.9i TSL(10 ='467,5 QB (W/IVLg.) = 0,511F,~O4~rF (W/M2,) = =0,297F=,.11 R (M) = 15.f~-TSL (I0,= ,140.7 QB CW/M2)~= 0;43T£+04 QT (36r/M`>) =~.O;297E-II R (M) = 17.39 TSL (K) = 419.5 QB OV/M2) = 0.377E+04 QT (W/M2) = -0.`>97E-11 R (M) = 19.1`>TSL (K) = 402.6 QB (W./M2) = 0.3~gEqq~t QT (W/M2) •-0.`>97E-11 R (M) = 20~6 TSL (K) ffi ssg .00~ (W/M2) = 0.t~OE+04 QT (W/M~) =-0.t~E-11 g (M) = 2`>.60 TSL 00: = 378.0 QB OV/M~) = 0.t~7~+o4 ~ (W/M~) =-0~97g- l l R ( ~ ) = `>4.~ TsL (10 = ~)S.9 QB 0V/M~) = 0.~S0~+04 QT 0V/M~) = = 0 . ~ 7 ~ H R (M) = 2 6 . 0 8 ~ (K} = 361.4 QB OV/M`>) = 0.~0WE+04 QT OV/M~) = -0.297E-I1 R (M) ffi 2 7 ~ ) TSL (K) = 355 .0QB OV/M~) ffi 0.188E+04 QT OV/M~) ~-O.~/E-11 R (M) = ~9.56 TSL (K) ffi 349.7 QB OV/M~) = 0,172E+O4 QT (W/M`>) =-0~9~TA1 R (M) ffi S ~ . ~ TSL' ( i~ ffi ~45.1 QS (W/M`>) = 0~I.'~+O4 QT 0V/M~) f f i > ~ l ~ R(M) = ~ 0 3 T S L ~)t) =. ~4LI Q~ 0V~M~) = 0.]4OE+O4 QT 0V/M~) =-0.~7E-11 R (M) = M.7"7TSL(K)'= 337,7QB (W/M~ = 0 .13~4)4QT t3~/M2) =-0.29~g-II

R (M) = S.q.00'rSL (K) =- ~ . 6 ~ (W/M~ = 0AHE+04 QT (W/M`>) = =0.~7~4~

• " R{M)= 45,20 TSL (IO-,= .S`>S.9 Q~ (W/~M2) ffi 0.953E+03 QT (W/M2)' ~ =0.29,7 E=II R (My= 46.94 TSL(K)= 3`>~.4QB (W~/M~) = 0.~85E+03 QT (W/M2) = .0.`>9~AI R (,M):= .48.68TSL {K) =~,~0~7,Q~(W/hi2) = 0.84~+0~ QT(,W,L/M2) =-0,`>97E-I I R(M) •- 50.4`> TSL (I0 ffi ~98,`>QB (W/M2) = 0.138E-t03 QT OV/M2) =.0.297FA1 .TIME (S)ffi 600.0000LYRTEI~P (K)ffi f)49;9 LYR H T (M). ffi 4.57 LYR MASS (~KG)f0.i~)|g+0/~ HRE OUTPUT(W) ffi 0_q999E+08 VENT AREA (M`>) = 28.`>0 LINK= 1 LINKTEMP {K)= 10`>9.11JETVEIX)Crl~ (M/S)= 6.'>47 JETTEMF ~K) ffi i:|,029:6" ~ ~ ! ~OPEI~ EQUAI~ 41.7098 ( 2 " R (~) = 0.00TSL(~) = 9 7 6 . 8 0 _ ~ O g / m ) =0,~`>S~O~ ~T(W/M~) -0,~T,-11 R ~M)= - 1.74 TSL (K) = 923.1 ~ 0At/M2) = 0.115~+05 QT (W~M2) ==0,297E=II- -

• R 0~) = S.4S~L ( K ) - ~ a O i l ' / m ) =0.10~+0S ~T 0~/~). = . O . ' ~ U

R{M) - ~ 6.95 TSL'(K)' = 710~'i QB (~/M2) = 0.861E+04-QT (WIM~) ==0.`>97E-11 R (M) = 8.69 T~'L 0g0 ffi fi~4,7 Q~ (Wl,bL2) = 0.761E-t04 ~ (W/~I2) ==0.297E-1-I

At 0a) -= -~i0.43 ~ L ( ~ = . ~ . 5 0,S . t W / m ) = 0 . ~ + O 4 QT 0 V l m ) = . 0 ~ n R (M) = ~9.~7 TSL (K) = ~41.7 Q B 0 V / m ) = o.r)mm+o4 Q~r 0V/UL~) =.O~Y~.I~

":R (M) = IS.9i TSL (K)~=-5o~,6~ (wIM~,) ffi o . ~ QT ( W / I ~ ~.0,297E=i1 R (M) ffi " 15.6S T S L 0 0 = 472.9 ~,~W,/M~) ffi 0.~t4~)E+04 QT (W/M~) = =0.̀ >97E-11 R (M) = 17.S9 TSL:(K) ffi 448A O ~ q / m ) ~O.387E+04~ (W/M~) •-0.297E-ll R 0~)= • 19,1~ .TSL (K) =~4~8.~ QS; (w/m) = 0.S42E+O4 QT ( W / m ) = . 0 . ~ 7 ~ ~ R (M) = 20:86 TSL (K) ffi 41t.9 QI] (W/M2) = 0.304E+0~ QT (W/M2) = ~0:~F~7E=II R (M) ffi 22.60 TSL (If.) = 3~8.6 QB OV/M2) = 0.27`>E+04 QT (W/,M2) = .0.297E-11

• R (M) = 24.$4 TSL (K) = 387,6 ~B (W/M`>) = 0.245E+O4 ~T (W/M`>) ffi -0.297E-11 R (M) = `>6.08TSL (I0= ~'78:4 Q B 0v/M~) ffi o . ~ + O 4 Q T (w/M`>) =..0.297F_AI .R (M) ffi `>7.8`> TSL:(10 = 370.6 ~!~ (WtM~) = 0.`>03E+O4 Q T (W/M~[) = ;0.~7E..ll

t

t

641

N F P A 2 0 4 M - - A 9 7 R O P

g (M) =

R (M) =

R (M) =

g (M) =

R (M) =

R (M) =

R (M) =

R (M) =

R (M) =

R (M) =

R (M) =

R (M) =

R (M) =

29.56 TSL (K) = 364.0 0..8

31.29 TSL (K) = 358.4 QB

33.03 TSL (K) = 353.5 QB

34.77 TSL (K) = 349.2 QB

36.51 TSL (K) = 345.4 QB

38.25 TSL (K) = 342.1 QB

39.99 TSL (K) = 339.2 QB

41.73 TSL (K) = 336.5 QB

( W / M 2 ) = 0.187E+04 Q T

( W / M 2 ) = 0.172E+04 Q T

( W / M 2 ) = 0.160E+04 Q T

( W / M 2 ) = 0.149E+04 Q T

( W / M 2 ) = 0.139E+04 Q T

( W / M 2 ) = 0 . 1 3 0 E + 0 4 Q T

( W / M 2 ) = 0.123E+04 Q T

( W / M 2 ) = 0.116E+04 Q T

43.46 TSL (K) = 334.1 QB ( W / M 2 ) = 0.1091/:+04 Q T

45.20 TSL (K) = 332.0 QB ( W / M 2 ) = 0.104E+04 Q T

46.94 TSL (K) = 330.1 QB ( W / M 2 ) = 0.986E+03 Q T

48.68 TSL (K) = 328.0 QB ( W / M 2 ) = 0.9411/:+03 Q T

50.42 TSL (K) = 299.4 QB ( W / M 2 ) = 0.147E+03 Q T

( W / M 2 ) = -0.297E-11

( W / M 2 ) = -0.297E-11

( W / M 2 ) = -0.297E-11

( W / M 2 ) = -0.297E-11

( W / M 2 ) = -0.297E-11

( W / M 2 ) = -0.297E-11

( W / M 2 ) = -0.297E-11

( W / M 2 ) = -0.297E-11

( W / M 2 ) = -0.297E-11

( W / M 2 ) = -0.297E-11

( W / M 2 ) = -0.297E-11

( W / M 2 ) = -0.297E-11

( W / M 2 ) = -0.297E-11

References

1. Purser, David A., "ToxicityAssessment of Comhistion Products," Section 2/Chapter 8, The SFPE Handbook of Fire Protection Engineering, second edition, Society of Fire Protection Engineers and National Fire Protection Association, 1995.

2. Peacock e t al., Software User's Guide for the Hazard I Fire Hazard Assessment Method, Version 1.1. NIST Handbook 146, Volume I, United States Department of Commerce, National Institute of StancLards and Technology, 199 !.

3. Cooper, Leonard Y. and [)avis, William D., Estimating the Environment a~ut tlw Response of Sprinkler Links in Compartment Fires with Draft. Curtains and Fusible Link-Actuated Ceiling Vents ~ Part 1I: User Guide for the C~mpnter C~,de Lavent. NISTIR 89-4122, United States Department of Commerce, National Institute of Standards and Technology, July 1989.

Appendix E Referenced Publications

E-I General. The following documents or portions thereof are referenced within this guide for informational purposes only and thus are not considered part of the recommendations of dais document. There are additional lists of references at the end of Appendices B, C, and D.

E-2 Bibliography.

Alpert, R.L. and Ward, E.J., "Evaluation of Unsprinklered Fire Hazards," Fire Safi~. Journal. Vol 7 (1984), pp 127-143.

Babrausk~, V., "Burning Rates," Section 3, Chapter 1 of SFPE Ha~uibook of Fire Protection Englneming. second edition 1995, pp. 3-2 to 5-4.

Carslaw, H.S. and Jaeger, J.C., Go~utuction of Heat Solids, Oxford, 1959.

DiNenno p.J., et at, e~. , Table B-7 of SFPE Handbook of Fire Protection En~neming. second edition 1995, pp. A-35 to A-36.

Drysdale, D., An Introduction to D3namics. Wiley, 1985.

Evans, ILl). and Stroup, D.W., "Methods to Calculate the Response Time of Heat and Smoke Detectors Installed Below Large Unob- structed Ceilings," Fire Technolog 3. Vol. 22, No. 1, February 1985, p. 54.

Gust.-ffgson, N-E, "Smoke Ventilation and Sprinklers - - A Sprinkler Specialist's View," Seminar at the Fire Research Station,

642

Borehamwood, UK, May 11, 1992.

Heskestad, G., "Model Studies of Automatic Smoke and Heat Vent Performance in Sprinklered Fires," Technical Report FMRC Serial No. 21935RC74-T-29, Factory Mutual Research Corp., Norwood, MA, September 1974.

Heskestad, G. and Bill, R.G., "Modeling of Thermal Responsiveness of Automatic Sprinklers, ~ Fire Safe 0 Science- Proceedings oft he Second International Symposium, Hemisphere Publishing corporation, New York, 1989(A), pp 603--612.

Heskestad, G. and Delidaatsios, M.A., "Update: The Initial Convective Flow in Fire," Fire Safety Journal, Vo115 [1989(B)], pp 471-475.

Heskestad, G. "Venting Practices," in Fire Protection Handbook, seventh edition, ed. by A.E. Cote, National Fire Protection Associa- tion, Quincy, Massachusetts, 1991, pp 6-104 to 6-116.

Heskestad, G., "Fire Plumes," Section 2, Chapter 2 of SFPE Handbook of Fire Protection Engine~rin~ second edition 1995, pp. 2-9 to 2-19.

Hinldey, P.L., Hansell, G.O., Marshall, N.1L and Harrison, R., "Experiments at the Multifunctioneel Trainingcentrum, Ghent, on dlelnteract ion Between Sprinklers and Smoke Venting," Fire Research Station, Building Research Establishment, Borehamwood, Hefts, 1992.

Hinkley, P.L., "Smoke and Heat Venting," Section 2, Chapter B of SFPE Handbook of Fire Protection Engineering~ second edition, 1995, pp 3-160 to 3-173.

Kanury, A.M., "Flaming Ignition of Solid Fuels," SFPEHandbook of Fire Protection Engineetng, DiNenno, P.J., ed., National Fire Protection Association, Boston, MA, 1988.

Miller, E. E., A Position Paper to NFPA 204 Subcommittee, "Fwe Venting of Sprinklered Properties," 1980.

Nelson, H. E. and Forssell, E. W., "Use of Small-Scale Test Data in Hazard Analysis, Fire Safety Science ~ Proceedings of the Fourth International .Symposium, International Association for F'we Safety Science, pp 9']1-982.

Notarianni, ILE., "Predicting the Response of Sprinlders and Detectors in Large Spaces," extended abstracts from the SFPE Seminar "Large Fires: Causes and Consequences," November 16-18, 1992, Dallas, Society for Fire Protection Engineers, Boston.

N F P A 2 0 4 M - - A 9 7 R O P

uintiere, J.G. and Harkleroad, M., "New Concepts for Measuring ,'une Spread Properties," NBSIR 84-2945, Nation,'d Bureau of

Standards, Gaithersburg. MD, 1984.

Tewarson, A, "Generation of Heat and Chemical Compounds in Fires," Sectiort 3, Chapter 4 of A'FPE Handbook of Fire Protection Engine~Mng. second edition, 1995, pp 3-55 to 3-124.

Thomas, P.H. and Hinkley, P.L., "Design of Roof-Venting Systems for Single-Story Buildings," Fire Research Technical Paper No. 10, Department of Scientific m)d Industrial Research and Fire Offices' Committee,Joint Fire Research Organization, London: H.M. Stationery Office, 1964.

Tien, C.L., Lee, K.Y. :rod Stretton, A.J., "Radiation Heat Transfer," Section I, Chapter 4 of SFPE Handbook of Fire Protection Engln~ring, second edition 1995, pp 1-65 to 1-79.

Troup, J.M.A., Large Scale Fire Tests of Rack Stored Group A Plastiea in Retail Operation Scgnarios Protected ~. Extra Large Orific, (ELO) Sprinklers, FMRC Serial No.J.l. 0XIR0.RR for Group A Plastics Committee, Factory Mutual Research Corp., Norwood, MA, November 1994.

Walton, W.D. and Notarianni, K.E., "A Comparison of Ceiling Jet Temperatures Me.x~u red in an Aircr,-fft H,'mger Tests Fire Widl Temperatures Predicted by the DETACT-QS and LAVENT Corn-

uter Models," NISTIR 4947, National Institute of Standards and ethnology, Gaithersburg MD, 1995.

Waterman, T. E. et al., Fire Venting of Sptinklered Buildings, IITRI ProjectJ08585 for Vendng Research Committee, lIT Research Institute, Chicago, IL 60616, July 1982.

Yu, H-Z and Stavrianidis, P., "Tile Transient Ceiling Flows of Growing Rack Storage Fires," Fire Safety Science- Proceedings of the Third International Symposium, Elsevier Applied Science, London, 1991, pp 281-290.

E-3 Computer Programs.

DETACr-QS computer code...

DETACr-T2 computer code..:

LAVENT (Link-Activated VENTS) computer code...

NOTE TO REVIEWER: Details on above three programs will be added during ROC preparation to permit document user to access these tools.

645