Appendix VIII-4

District Heating

ALTERNATIVE MITIGATION MEASURES DISTRICT HEATING SYSTEM ALTERNATIVE

BOWLW ELECTRIC GENERATING STATION ORANGE & ROCKLAND UTILITIES, INC.

AND ROSETON GENERATING STATION

CENTRAL HUDSON GAS & ELECTRIC CORP. AND

INDIAN POINT 2 NU-AR GENERATING STATION CONSOLIDATED EDISON COMPANY OF NEW YORK

AND INDIAN POINT 3 NUCLEAR GENERATING STATION

NEW YORK POWER AUTHORITY

MAY 1993

STONE & W B S T E R ENGINEERING CORPORATION

.. . . * Afternative Mit I s i o n N e w

Bowline . Roseton a nd Indian Point inP S m Altemati VC

Table Of Contents

Title Section pape 1 . Introduction .................................................. 1

2 . 3 Bowline Point Electric Generating Station District Heating System ......... 2.1

2 2

f

23

2.4

Heat b a d Assessment .................................... 3

2.1.1 Analyses of the Surrounding Potential Service Area .......... 3 2.12 Heat Load Determination ............................. 4

2.13 Steam Sendout to U.S. Gypsum Corporation ............... 6

22.1 Description of the Existing Plant Configuration ............. 8

22.2 Potential Plant Modifications for District Heating ........... 9 2.23 District Heating EQuipment Sizing and Layout .............. 9

Power Plant Retrofit Analysis ............................... 8

22.4 Effects on Plant Generation and Heat Rate ................ 12

2.2.5 System Reliability and Back-up ......................... 12

2 2 6 Power Plant Retrofit Costs ............................ 13

District Heating Transmission and Distribution System ............. 13 23.1 General Desijp Considerations ......................... 13 232 Piping System &sign ................................ 14

233 Piping byout ...................................... 16 23.4 Piping Cost Analyses ................................. 17

System Capital and Operating Costs and Revenues ............... 17

2.4.1 System Capital Costs ................................. 17

2.42 Annual Operating Costs .............................. 18

2.43 System Revenue .................................... 18

Pane 3 . Indian Point Unit 2 and Unit 3 Nuclear Stations District Heating System

3.1 Heat Load Assessment .................................... 19 3.1.1 Analyses of the Surrounding Potential Service Area .......... 19 3.1.2 Heat Load Determination ............................. 19

32 Power Plant Retrofit Analysis ............................... 21 32.1 Description of the Existing Plant Configuration ............. 21 322 Potential Plant Modifications for District Heating ........... 22 3.2.3 District Heating Equipment Sizing and Layout .............. 23

32.4 Effects on Plant Generation and Heat Rate ................ 25 32.5 System Reliability and Back-up ......................... 26 3.2.6 Power Plant Retrofit Costs ............................ 26 District Heating Transmission and Distribution System ............. 27 3.3 33.1 General Design Considerations ......................... 27 332 Piping System Design ................................ 27 333 Piping layout ...................................... 28

33.4 Piping Cost Analyses ................................. 28 3.4 System Capital and Operating Costs and Revenues ............... 29

3.4.1 System Capital Costs ................................. 29 3.42 Annual Operating Costs .............................. 29 3.43 SystemRevenue .................................... 30

4 . Roseton Generating Station District Heating System 4.1 Heat Load Assessment .................................... 31

4.1.1 Analyses of the Surrounding Potential Service Area .......... 31 4.12 Heat Load Determination ............................. 32 4.13 Steam Sendout to Potential Process Steam Customers ........ 33

..

Section m 4 2 Power Plant Retrofit Analysis ............................... 35

42.1 Description of the Existing Plant Configuration ............. 35 42.2 Potential Plant Modifications for District Heating ........... 36 4.2.3 District Heating Equipment Sizing and Layout .............. 36

42.4 Effects on Plant Generation and Heat Rate ................ 39

4.25 System Reliability and Back-up ......................... 39

4.2.6 Power Plant Retrofit Costs ............................ 40

District Heating Transmission and Distribution System ............. 40 4 3

43.1 General Design Considerations ......................... 40

43.2 Piping System Design ................................ 41

4 3 3 Piping Layout ...................................... 43 Piping Cost Analyses ................................. 44

4.4 System Capital and Operating Costs and Revenues ............... 45 System Capital Costs ................................. 45

4.42 Annual Operating Costs .............................. 45

43.4

4.4.1

4.43 System Revenue .................................... 46

5 . Impact of District Heating on River Water Temperature for all Plants 5.1

5 2

5 3

Bowline Point District Cooling System ......................... 47

Indian Point District Cooling System .......................... 47

Roseton Station District cooling System ....................... 48

6 . District Cooling System Application

6.1

6.2

Bowline Point District Cooling System ......................... 49

Indian Point District Cooling System .......................... 53

6 3 Roseton Station District Coofing System ....................... 53

o3mm.mi iii

Tables and Sketches 1. Table 2-1

2. Table 2-2

3. Table 2-3

4. Table 2-4 5. Table 2-5 6. Table 2-6

7.

13.

14.

15.

Table 2-7

Table 3-2

Table 3-3

Table 3-4

Existing Fuel Consumption of Potential Users for Bowline District Heating System . Peak Heat Loads Summary for Bowline District Heating

System Steam Pipe Sizing From Bowline Station to US. Gypsum Corporation District Heating Pipe Sizing for Bowline Station Cost Etimate for Bowline Power Plant Modification Piping Cost Estimate From Bowline Station to U.S. Gypsum Corporation Bowline District Heating System Piping Cost Estimate

8. Sketch M-SK-2-1 Power Plant Retrofit Schematic for Bowline Station District Heating

9. Sketch M-SK-2-2 District Heating Piping Layout for Bowline Plant Vicinity

10. Sketch M-SK-2-3 Kay Fries Industrial Park

11. Sketch M-SK-2-4 Helen Hays Hospital 12. Table 3-1 Existing Fuel Consumption of Potential Users for

Indian Point District Heating System Peak Heat Load Summary for Indian Point District Heating System District Heating Pipe Sizing for Indian Point System Cost Estimate for Indian Point Power Plant Modification

16. Table 3-5

17.

18.

19.

Sketch M-SK-3-1

Sketch M-SK-3-2

Sketch M-SK-3-3

20. Table 4-1

21. Table 4-2

22. Table 4-3

23, Table 44

24. Table 4-5

25. Table 4-6

26.

27.

Sketch M-SK-4-1.

Sketch M-SK-4-2.

xi& Indian Point District Heating System piping Cost Estimate Power Plant Retrofit Schematic for Indian Point Station District Heating District Heating Piping Layout for Indian Point Unit 2 System District Heating Piping Layout for Indian Point Unit 3 System Peak Heat Load Summary for Roseton District Heating System Steam Pipe Sizing From Roseton Station to Process Steam Customer Roseton Station District Heating Pipe Sizing Cost Estimate for Power Plant Modification, Roseton Power Station Piping Cost Estimate From Roseton Station to Process Steam Customers Roseton District Heating System Piping Cost Estimate

Power Plant Retrofit Schematic for Roseton Generating Station District Heating Piping Layout For Roseton Generation Station

V

,I* . i

SECTION 1

1. INTRODUCIION

In December 1992, Stone and Webster Engineering Corporation (SWEC) was contracted by Orange and Rockland Utilities, Consolidated Edison company of New York, New York Power Authority and Central Hudson Gas & Electric Corporation to perform a preliminary study to investigate technical and economic feasibility of various alternates to reduce the quantities of waste heat rejected to the Hudson River and to mitigate aquatic ecology effects associated with power generation by the four power plants located on the lower Hudson River, namely Bowline Point Station, Indian Point units 2 & 3 nuclear plants, and Roseton electric power station. This study addresses the District Heating and Cooling (DHC) alternate and evaluates the effect of DHC system in lowering the river water temperature. The DHC study involved assessment of waste heat reduction alternatives primarily in three areas? namely, export of heat from Bowline and Roseton stations in the form of process steam for industrial or institutional users, export of hotwater heat to potential industrial and institutional customers for comfort heating from all four plants, and a qualitative evaluation

of potential district cooling systems for all four power plants. This study report discusses in detail potential process steam customers in the vicinity of Bowline and Roseton power stations, their specific process steam requirements, and evaluates the technical and economic feasibility of exporting process steam to the potential customers. It also addresses the loss of plant generating capacity as a result of exporting steam and the effect such steam export would have on the reduction of thermal discharge to the Hudson river.

The second major effort of the study concentrated on assessment of comfort heating and domestic hotwater heating load in the potential service areas surrounding the four power stations. This evaluation included an assessment of the current comfort heating and domestic hotwater load for potential customers including industries, schools, and hospitals within a seven miIe radius of the power plants.

03TT1oo.aOl 1

The investigation also includes the required changes to the existing turbine cycle for district heating application and the necessary physical arrangement of the plants to provide thermal

energy to the potential users. Budgetary capital cost estimates were prepared for the process steam lines to potential customers, the powerplant retrofits for district heating, and hotwater transmission and distribution piping network. Economic analyses and incentives

required for the potential customers are afso included in the report. Impact of district heating on the lost electrical. generation and river water temperature are addressed in this

report. Finally, the study report is concluded with a qualitative evaluation of district cooling system application to the four power plants.

l

0377700.001 2

SECTION 2

SECTION 2

2.1

B O W N E ELECIXIC GENERATING STATION DISTRICT HEATING SYSTEM

Heat Load Assessment

2.1.1 Analyses of the Surrounding Potential Service Area

A survey was conducted of the service area in the vicinity of the Bowline Point Generating Station in order to assess availability of heat loads. The survey indicated that there is one major potential process steam customer approximately two miles north of the Bowfine Point Station. This is the U.S. Gypsum Corporation plant which needs process heat for operating its two hot air drying ovens for drying of sheetrock panels during the manufacturing process. These ovens could use steam heat from the Bowline plant. At the present time natural gas

i s used for these ovens. In addition, there is an industrial park approximately half a mile to the west of the U.S. Gypsum plant known as Kay Fries Industrial Park which has eight manufacturing and warehousing facilities which could provide significant heat load for comfort heating. Homick Curtains, another manufacturing facility is located next to the Bowline Plant. One quarter mile west of the Kay Fries Industrial Park is Helen Hays Hospital which has approximately 12 buildings including a main pavilion spread out over approximately four to five acres of land. In addition, two nursing homes are located south

of the Bowline Plant. The hospital and nursing homes could provide sizable comfort heating and domestic hot water load. Sketches 03777-M-SK-2-3 and M-SI(-2-4 show the layout of the Kay Fries industrial park and Helen Hays Hospital complex.

There are five school buildings in the potential service area which were also considered for the comfort heating and domestic hotwater load. They are Farley Middle School, Haverstraw Middle School, West Haverstraw Elementary School, G. Nearly Elementary

03m.001 3

School and N. Garnerville School. Several potential process and district heating customers

were visited and infomation was obtained about their existing heating systems.

2.12 Heat b a d ~ e ~ i n a t i o n

Heat load density and proximity of the heat load to the heat source (Bowline Point Station) are very important for making a district heating system economically viable. The first step in establishing a heat load was to identify potential customers for both process and comfort heating in the service area within close proximity of the plant. A process steam customer identified was U.S. Gypsum Corporation which uses two natural gas fired hot air ovens. The plant manufactures sheetrock (wallboard) panels. In the manufacturing of the wallboard material, U.S. Gypsum uses two gas fired drying ovens to provide 450" F hot air for drying the wallboard. The oven ratings are 524,555 Btu/minute and 375,714 Btu/minute. These ovens operate for approximately 8,100 hours per year. The plant also has three small office buildings which use gas for comfort heating. The gas consumption for the 1991-92 year was l,0&4x109 of which 952~10~ Btus was used for the two drying ovens. The remaining 1 3 2 ~ 1 0 ~

Btus were used for comfort heating. U.S. Gypsum has a separate meter for the process gas.

In order to estimate the heat load for a district hot water heating system, potential customers were identified by reviewing maps and by visiting large institutional and industrial customers facilities. Furthermore, gas bills for customers with large comfort heating loads were collected and reviewed. These facilities are identified and located on sketch 03777-M- SK-2-2. Gas heating bills from each of these customers are summarized in Table 2-1 which shows monthly and yearly gas consumption information. It was assumed the existing gas fired boilers and furnaces at the customers' heating plant operate at 75% efficiency. The peak load was estimated by first calculating the equivalent hourly heat load for the coldest

month and then adding a 30% margin, and correcting it for boiler efficiency. This peak load was used as a design heat load. Peak heat loads are listed in Table 2-2.

03m.001 4

Following potential customers were considered for the Bowline Station hotwater district ...

i i heating system:

0 Lighting Services Company 0 Time Square Lighting Company

Q.E.P. Equipment Company 0 Stony Point Electronics 0 Gotham Ink Company 0 Diplomat Juvenile Corp.

hul-x Products

Schools. HosDital. and NursinP Homes

Farley Middle School Haverstraw Middle School W. Haverstraw Elementary School G. Nearly elementary School N. Garnerville Elementary School Helen Hays Hospital Greenville Nursing Home Riverside Nursing Home

Industries

0 U.S. Gypsum Corporation 0 Hornick Curtains

03?77tS.001 5

The steam export system for U.S. Gypsum was considered independently. The district hot water heating system was sized based on the sum of customer peak loads, plus some design margin for future customer addition.

2.13 Steam Sendout to U.S. Gypsum Corporation

This analysis was prepared to determine the feasibility of transporting steam from the Bowline Point Generating Station to the U.S. Gypsum plant thereby reducing the heat rejection to the Hudson River while satisjing the plant’s process steam requirements.

Desi-m Pa rameters a nd AssumDt ions

e

e

Steam will be used to provide two ovens with 524,555 Btu/minute and 375,714

Btu/rninute of hot air at 450°F. Direct distance of the U.S. Gypsum plant to the Bowline Point Station is approximately two d e s , but the piping length is 16,400 feet because piping would run along Route 9W as shown on MSK-2-2.. The steam and condensate piping will be run side by side in the Same trench. Steam from Bowline Unit 2 is used for this application. Assumed 100% condensate return from U.S. Gypsum plant to Bowline station.

exriotion of Pote ntial System Des i a

The potential source considered for process steam for this application was the cold reheat line (steam line from high pressure turbine exhaust). No other extractions from the

intermediate or low pressure turbines could provide the flow and temperature required. Since the operating conditions of the cold reheat (454 pounds per square inch absolute

(pia) and 650% ) are the closest to the required conditions its use was evaluated.

0377700.001 6

i A IO inch steam line would be appropriate for this service. Using a 10 inch steam line, run

dong Route 9W and the railroad tracks, the pressure drop per d e is calculated at approximately 24 psi (see Table 2-3). The total line drop would be 72 psi, which would result in 378 psia available at U.S. Gypsum. This flow and pressure would pennit the use of the cold reheat steam currently used for the Number 6 High Pressure (HP) heater. Approximately 60,OOO Ib/hr additional extraction from the cold reheat line could be used. This will reduce generator output by 8669 KW which wil l account for 1.4% of the Unit 2 output. Tbennal load on the condenser will be reduced by 34.98 million BTLJ/hr (MMBTU/hr) or about 13%. This will reduce circulating water discharge temperature to

the river by 0.22 "F from Unit 2 discharge.

A 4 inch return line would be required to carry up to 160 gallons per minute (GPM) of condensate back to the Bowline plant. The total pressure drop would be approximately 100 psi. Based on a condensate return temperature of over 4oosF, the condensate could return to the cycle through the high pressure heater drains.

Both the steam and condensate lines would be run with pre-insulated pipe installed below ground in a common trench. The capital cost includes the cost of trenches and manholes.

The cost of furnishing and installing steam and condensate pipe to U.S. Gypsum is

$5,753,929. Supplying and installing of air heaters required for hot air heating at U.S. Gypsum plant would cost approximately $70,000. Therefore, the total cost of this modification is estimated at $5,823,929.

Providing steam to US. Gypsum Corporation will reduce thermal discharge to the Hudson River by 0.22 "F from Unit 2 discharge. Although it is feasible to provide steam to the

facility it will reduce the Bowline Unit 2 electric power generation by 8.67 W e at design

steam export flow.

(13777oo.w1 7

23

This Section describes the plant modification required at the Bowline station to support the esign of a district heating system, and evaluates the effect it would have on plant

It discusses the feasibility of locating various district heating system performance. equipment in the Unit 2 turbine building.

23.1 Description of the Existing Plant Configuration

The Bowline Point Generating Station is located in the town of Haverstraw, New York. The station is comprised of two generating units installed during the early seventies. The capacities of the units at the Bowline Point Station are 598 Mw each. These units are both tandem compound turbines with steam reheat and several stages of extraction steam for feedwater beating. This permits flexibility in selecting the optimum steam pressure to match district heating needs. Exhaust steam is condensed in a water cooled condenser. At full load this results in the discharge to the river of 2,709 x Id) Btu/hr from each of the two units. Plant operating data was reviewed for the 12 months period from January to

December 1991. Based on this review it was determined that Unit 2 was the best candidate for modification to supply district heating steam due to its higher operating hours.

Bowline Unit 2 has a high pressure (HP) turbine, a steam reheater, an Intermediate

Pressure (IP) turbine, cross over pipe and a Low Pressure (LP) turbine. The IP turbine has one feedwater heating extraction and the LP turbine has three extractions for feedwater heating. All extractions are uncontrolled. The LP turbine exhausts to a surface condenser operating at 2.00" HgA. Gooling water taken from the Hudson River i s pumped to the condenser at the rate of 315500 GPM. It is returned to the river with a maximum temperature rise of 17.18T. Make-up water is supplied to the system in the condenser.

wm.001 8

223 Potential Plant Modifications for District Heating

fn order to supply a hot water system with 250°F water it will be necessary to provide Steam

a condensing district heating water heat exchanger at 35.5 psia. This provides a saturation temperature of 26ooF and a heater terminal temperature difference of 10°F. n e lowest energy extraction point for Bowline Unit 2 which meets this criteria is extraction D (on the heat balance diagram) at 722 psia for full load. This extraction is currently sized for 176,875 lb/hr and it is proposed this be increased by 48,239 lb/hr for the district water heater. This represents an increase extraction flow Of 27% which is assumed to be within

the allowable turbine extraction nozzle loading. However, this should be confrmed with the turbine vendor during the detailed design development phase of the project.

The piping wiU be modified to include a connection for the district heating water heat

exchanger steam supply with a pressure control station. Also heater drain piping with a level control station and a baffled condenser connection will need to be added. In addition to the district water heat exchanger other equipment which must be located within the plant include district hot water pumps, expansion tank, water softening equipment, pressurizing water pumps, switchgear and control panel. It is assumed the existing plant water laboratory

can monitor district heating water through the use of grab samples.

22.3 District Heating Equipment Sizing and Layout

Sketch 03777-M-SK-2-1 provides a schematic of the district heating power plant retrofit. With a steam extraction of 48,239 lb/hr and an expected return water temperature of 160°F

the Wtem will provide the required 1207 gpm of hot water at 250°F to satisfy the district comfort heating demand. The system wiI1 be comprised of a shell and tube district water heat exchanger, three 50% capacity district heating water circulating pumps, an expansion

tank and two 100% capacity pressurizing pumps.

9

The district hot water circulating water pumps would be specified at 625 GPM at a head of 275 feet. For full load operation two pumps will be operating and one pump will be standby. Tlre pumps will be single stage horizontal centrifugal design with a ductile iron casing. The pumps will be driven by 75 HP electric motors. Two 100% capacity pressurizing pumps will

be provided. The operating pressurizing pump provides up to 20 gpm of water when there is a need for system make-up. Make-up is required when there a leak in the system or to make up volume during heat load reduction when average water temperature is decreasing. The pumps wil l be ductile iron horizontal centrifugal single stage pumps.

Expansion and contraction of system liquid volume Will be accommodated within the expansion tank, The carbon steel tank will be 12 feet in diameter and 16 feet long with

dished heads with 1/2 inch thick shell. The district water heat exchanger will transfer heat from the extraction steam to the district circulating water. The heat exchanger will be a vertical condensing heater of the shell and U-tube type. The shell will be carbon steel and the tubes are 304 SS. It will be designed to heat 589,960 Ib/hr of district circulating water from l6OT to 25OOF. The heat exchanger will provide 2,778 square feet of surface for heat transfer.

In the event the Bowline Unit 2 station is unavailable for steam extraction a package hot water boiler will be provided for back up. The district water will be diverted from the heat exchanger to the hot water boiler for heating. The packaged boiler will be complete with instruments and controls. Water chemistry will be maintained by make up water softeners sized for 25 gpm to minimize scale formation. Steam will be supplied to the district water heat exchanger by a 14" Schedule 40 carbon steel line with a pressure control station.

Heater drains would be returned to the condenser by a 4" Schedule 40 carbon steel line with the heater liquid level control station. Other piping within the power plant includes

/

the 12" pump suction header, the 12" pump discharge header to the district water heater and the hot water boilers, the 2" pressurizing pumps suction and discharge fines and the 2" pipe

to reqcle water back to the expansion tank.

o3nmo.001 10

Plant Layout

Ihe pumping and heating equipment would be located in the Bowline Unit 2 turbine building. District hot water circulating water pumps, water softener and pressurizing pumps

would be located at grade along the west wall of the turbine building between columns 10 and 22. The district water heat exchanger would be located on the turbine deck along the south wall between columns 11 and 12. The heat exchanger will be set between the ventilation duct to minimize interference with crane access space on the turbine operating floor. Due to the size of the hot water boilers it will be necessary to locate the boilers in a separate new building. The district water expansion tank could be located on the roof of the turbine building. It would need to be insulated and freeze protected with an immersion

beater.

The above layout reflects a preliminary evaluation which must be confirmed during the detailed engineering and design feasibility study.

Water to the district would be provided at a constant flow during the winter months. This flow would be maintained at the system design of 1,207 gpm. The water temperature will

be regulated by means of a district water heat exchanger bypass valve. The amount of water bypassed is regulated by the r e m water temperature from the district. As heat load is reduced hot water supply temperature will be reduced by the plant district heating control system.

Steam to the district heat exchanger would be regulated by maintaining a constant pressure in the heat exchanger. As district heat load decreases the steam flow through the heat exchanger decreases causing less steam to condense. As the rate of steam condensation

decreases less steam is required to maintain pressure. The heater drain level control valve will maintain the required level of water in the heater to prevent steam blowthrough.

Q3TnUO.001 11

..

22.4 Effects on Plant Generation and Heat Rate

implementation of a district heating system would result in Bowline Unit 2 derating but the Unit 2 heat rate would improve due to extraction of heat born the turbine cycle. By increasing the extraction flow at point D on the heat balance diagram to 48,239 Ib/h and the net power output will be reduced by approximately 3,697 kW. This represents a 0.6%

loss of the Unit 2 output. By condensing this export steam outside the condenser heat rejection to the river is reduced by 38.4 x 106 Btu/hr or about 1.42% of the full load unit

2 heat rejection to the river. With the circulating water flow of 315,500 GPM the new maximum temperature rise would be 16.90"F. This is a reduction of 03°F from the original temperature rise. At part load district heating system operation improvements and heat rejection to the river would be reduced proportionately.

22.5 System Reliability and Back-up

As with all public utility services the reliability of the heating water supply should be of

paramount importance if customers are expected to convert from their current heating systems to the district heating system. High reliability can be achieved by either providing steam supply from two or more units or providing an independent package boiler to senice the district beating system. m e most secure approach to insure high reliability would be to provide a dedicated package boiler firing natural gas or No. 2 fuel oil. The cost of steam from the package boiler will be high due to the high grade fuel which must be used, The operating cost associated with the back-up boiler is considered insignificant due to the short duration of expected use. The higher reliability which the package boiler provides will improve the likelihood of attracting industrial customers if they can achieve a savings try not maintaining their current heating systems. For these reasons a back-up boiler is included

in the system design, It is estimated that two (2) 700 HP hotwater boilers would be required as the backup heat supply for the Bowline hotwater district heating system. It should be noted that the addition of this equipment represents a potential environmentat

impact due to boiler emissions.

2.2.6 Power Plant Retrofit Costs

Table 2-5 provides a s u v of the major component and installation costs including the hot water distribution piping based on the system described above. It should be noted these are preliminary estimates based on locating equipment with an existing operating plant. During detailed engineering it is possible that consideration of access, space, final equipment size and the need to install the system with minimum impact on the operating plant could increase the cost.

It should be noted that the bulk of the costs are associated with the district water piping material and installation. This is due to the long distance between the power plant and the largest customers. There seems to be little potential to reduce this portion of the capital

Cost.

The cost of modifying heating system at the customer location is not included in the capital cost estimate. It is assumed the customer will bear this expanse in order to receive the benefit of lower heating costs from the district heating system.

23 J3istri ~~ ct Heatinn Transmission and Distribution SystJzn

23.1 General Design Considerations

This section addresses three different piping systems available for the steam and hot water transmission and distribution system. The steam and hotwater piping is assumed to be normally buried in the ground and will be run by the side of roads and streets, and along

&e railroad tracks. The piping system for steam and condensate return lines will be Perma- Pipe or R i d type (piping manufacturers’ names) and the hotwater piping would be I.C. Moiler type. The high temperature steam lines (5OOOF) will need thermal expansion loops at a certain interval and manholes for steam trap maintenance. An additional 15 percent cost has been added to both procurement and installation costs to allow for the cost of

13

*-

expansion loops. In addition, ten manholes are assumed per mile for the steam piping for steam trap maintenance at a cost of $2000 per manhole.

The low temperature (maximum 250°F) hot-water piping to be used for comfort heating and domestic hotwater load will be of conduit design. The conduit design is very widely used in Europe for this application. It consists of a thin-wall carbon steel carrier pipe encased in polyurethane insulation and polyethylene casing. It also has a built-in leak detection wire embedded into the polyurethane insulation.

23.2 Piping System Design

?he steam Lines for the U.S. Gypsum Corporation was sized for a pressure drop of 24 psi per mile of pipe to achieve the required process steam conditions at the U.S. Gypsum plant. The condensate from the plant will need to be pumped back to the Bowline Station to minimize station make-up water requirements.

The comfort district heating piping (hotwater piping) is sized based on the heat load to be supported by that section of pipe. The hotwater supply and return temperatures of 250°F and 160°F respectively are used as a design basis on a peak winter day (typically in January or February) for the design hotwater flow calculation for the hotwater piping system. The district heating plant control system will be designed to vary the hotwater supply temperature to the district heat customers as a function of the outdoor temperature, while keeping the hotwater flow through the piping constant.

The shop fabricated conduit piping for the hotwater service is less expensive to install

becaw it will be shipped in 40 feet length with the polyurethane foam and polyethylene casing all in one piece. During the manufacture of the conduit the polyurethane foam is poured in the space between the steel pipe and the casing in a liquid form, thus forming and expanding in the space and bonding itself to the steel pipe and casing walls. This type of construction will provide structurally stable insulation that will not shift or shrink. NO

(-

I' \*

clamps are required to fasten the insulation in place as in the conventional piping system. The supply and return lines will be installed side by side in the same trench.

The LC Moller type of hotwater piping system can be installed without any expansion loops. It uses E-M& @-System Installation Technique). The E-Muff is a corrugated sleeve type component that operates only once when it is faed to absorb movement corresponding to a certain pipe length at the mean temperature (usually 160°F.) The first time the hotwater is sent through the piping system, the piping will expand and the E-muff will be compressed. n e E-muff is fixed by welding at this time, and the piping system is virtually stress-free at

this point. (The system is full of hotwater at a mean temperature of 160°F which is approximately midway between the two extreme condition of 70°F and 250°F corresponding to cold or bot piping conditions). The piping system is thus locked at this mean temperature, and future temperature variations will be converted into allowable material stresses in the steel pipes. Thus the use of E-muffs eliminates the need for the conventional thermal expansion loops required with the other systems.

The I.C. Moller piping system offers the following advantages compared with the conventional systems:

Pipe anchors are not required in the main run of supply and return headers since the thermal expansion loops are eliminated. (Pipe anchors may be required at the building entrances). Branch connections could be installed later without the need for inserting tee fittings in tbe main run of pipe. The outer polyethylene jacket is fusion welded for strength and air tightness

thus ground water cannot penetrate the joint. This is of special importance where ihe piping system crosses a water stream. Piping installation costs are substantially reduced due to elimination of thermal expansion loops and the associated pipe anchors.

0377700.001 15

(e) The IC. Moller thin walled pipe can be procured as curved pipe to match tfie contour of gentle curves in the system thus eliminating the need for additional pipe fittings.

The drawback of the I.C. Moller piping is that it can not be used at a senice temperature higher than 250°F because above this temperature the polyurethane foam starts melting. merefore, for higher temperature steam or hotwater lines, Perma-Pipe or Ricwil type

systems wiil need to be used.

233 Piping Layout

For the steam sendout and condensate return pipe to U.S. Gypsum Corporation, it was

assumed that these lines will be run in a trench next to the road and railroad tracks leading from the Bowline station to U.S. Gypsum Plant. Obtaining the right of way for running these lines would require a detailed investigation of the existing right of way ownership of the railroads, utilities, municipalities and private property owners of the adjoining properties.

This investigation is outside the scope of this study.

n e hotwater comfort heating piping would be run by the side of major roads and streets in the service area. The 12 inch main header would run parallel to route 9W and railroad

from the Bowline station to the potential customers. The branch lines to the customers

were sized based on the customer peak flow requirement. The piping was sized to limit the maximum pressure drop in the piping circuit to 150 psi thus keeping the district heating &dating water pump shut off head within the piping design pressure of 220 psig. The piping layout for the hotwater system is shown on Sketch 03777-M-SK-2-2 for the Bowline

system. The piping lengths of the various piping sections are listed along with their respective pressures, temperatures, flows, pressure drop, velocities and other piping properties in Table 24. The design pressures and temperatures of the hotwater district heating piping are also listed in this table.

23.4 Piping Cost Analyses

Piping costs for the transmission and distribution piping were developed by estimating the costs of the following items for both the high temperature steam line to U.S. Gypsum

Corporation, and the hotwater piping to potential comfort heating customers.

(a) @)

Removal of existing surface and excavation of trench Removal and repair of existing road pavement at the road crossing for piping installation Piping material cost including allowance for valves and fittings, and piping installation costs Cost of sand bed in the trench for laying pipes and cost of concrete anchors Cost of back filling the trench after installation of piping and the backfill Cost of top soil and seeding after tempting of bacUill Cost of expansion loops and manholes for the steam piping

(c)

(d) (e) (f)

(g)

Cost of piping materials are based on budget estimates from the piping vendors whereas labor costs for excavation, backflling welding, joint forming, topsoil and seeding, etc are based on Stone & Webster inhouse data. These piping cost estimates are presented in Tables 2-6 and 2-7.

2.4 &tern CaDital And One rating Costs And Revenues

2.4.1 System Capital Costs

Table 2-5 provides the capital costs for design and construction of a district heating system including the cost of plant retrofit. This total was increased by 15% €or engineering and 25% for contingency for a total capital cost in 1993 dollars of $6,957,402 These costs are based on manufacturer’s budgetary pricing for pumps, heat exchanger and pre-insulated

piping and SWEC in house data for the remaining piping and components. This estimate

0377700.001 17

assumes the district heating customers bear the cost of equipment within their facilities and

does not consider any additional incentives or costs by the utility to induce heating

customers to sign up.

2.4.2 Annual Operating Costs

Costs and revenue associated with the operation of the district heating system should be determined on an annual basis. This requires the use of an appropriate discount rate and inflation rate. The annual costs would include replacement power cost, which includes both lost generation and pumping power and O&M costs. The annual O&M costs are normally

estimated at 3% of the capital cost of the power plant equipment, and 0.5% of the capital

costs for piping based on past experience. These costs are to be estimated by the utility.

The annual replacement power is estimated to be 22,584 MWhrs for the Bowline district

heating system.

The operating cost due to lost generation for process steam for U.S. Gypsum was $2,107,037 per year based on a replacement power cost of 3ct/kwhr. The cost is much greater than the potential yearly revenue of $1,039,314, therefore, it was not evaluated further.

2.43 District Heating System Revenue

District heating system revenue is based on supplying customers with the same quantity of useful heat as in the year 1991 at approximately 90% of that year's billing for ~ t w r a l gas.

The large gas users, Helen Hays Hospital and U.S. Gypsum had negotiated lower rates due

to large gas consumption contracts. It should be noted that Helen Hays Hospital's gas contract expired in 1991 causing their rates to rise and they may be able to obtain lower

rates in new future contracts. The effect of such a low rate contract on this study would be

a reduction in annual revenue below 90% of 1991 billing. The annual revenue in 1993 dollars based on participation of alI identified customers is $1,026,762.

0377700.001 18

i

FARLEY MIDDLE SCHOOL 1 1113 26611 1379 Ham HAYS WSP. 1 13SS 11239 1 lO(100

TABLE 2-1 WSTINQ FUEL CONSUMPTION OF POTENTIAL USERS BOWLINE STATION

872 320 861 42 7 1 84 703 I 1088 1280 1 0174 7058 56(9 SO50 53M) - 1 11008 8187 I 11000 13114 1 $01017

(IN MCF NAT GrS EOUIV.)

UGHTING SERV (KF) 1 403 3481 = 209, 00 TtME SQ UGHTINQ (KF) I 334 200 1 219 I 1 U I 51

261 1s 201 20 081 151 2391 1 m 4 32 33 31 1 30 78 142 180 1-2

'INSLJL-X PRODUCTS IS IN THE PROCESS OF MOVING AND THIS DATA DOES NOT REFLECT ACTUAL HEAT LOAD

O.E.P. co (w) I 107 781 701 281 8 1 3 2 STONY PT ELEC (KF) 97 , 7sl m l 36 31 2 , 1 ,

M R SYSTEM SUING USE THE MAXIMUM MONTHLY TOTM DIVIDED BY DAYS IN THAT MONTH AND CONVERTOD TO EQUlValENT BTUMR (lMCF-1X10'6 BN) AND Aw 3096 MARGIN ASSUME MSlSTlNQ BOILERS OPERATE AT 7% VFICIENCY.

21 2 4 27 U 374.9 1 1 1 6 11 371.7

CONFORT HEATING LOA0 - 52130524 B N / H R FlEoUlRED FLOW - 48239.07 LB/HR

QOTHAM INK (w) DIPLOMAT JUVENILE (KF)

"PROCESS STEAM IS REQUIRED AT HIGHER PRESSURE AND WPERATUE CONDITIONS THE COMFORT HEATINQ STEAM. THEREFORE IT WlLL BE CONSIDERED SEPARATELY.

6 1 5 s 5 116 ' 214 1 247 1 lu2 361 I 204 2611 229 911 7-70 I 0 (Lo71 421 0 4 1 161 1 0 2 in 2821 *ssl 3~0.2

10 7 , 9 JNWL-X PRO0 (KF)' 0 73 9128 I 41 I 171 I US QYPSUM I 14642 17048 20206 13821 0 0 0 1 0 CONFORT HEATlNa 1 I

7 , 36 0 1 0 1281.2 14018 17074 1- 15677 13183

HAVERSTRAW MIDDLE SC I 1894 I 1861) 2301 1512 130 42 30 1 23 I 76 I 435 1142 I 1671 111235 W HAVERSTRAW ELEM SC 732 1 7801 &3B 331 651 35 U 5 1 67 07 8351 !s7 42001 G. NEARLY ELEM SCH 718 5LIll 540 200 311 30 3 47 40 61 1 527 so6 3420

1 11 0 2 1seI 282 *ss 3480.2 N. GARNERVILLE ELEM SC 549 491 354 237 01 1 36 2 3 , 25 30 41 I 338 412 W

GREENVILLE NURSING I 007 537 536 337 265 285 257 271 526 391 1 528 626 RWERSIDE NURSINQ 2668 2149 I 2odb 1340 1001 1 1 s 1020 1080 2105 1 s 2115 2507 206367

HORNICK CURTAINS ne w 007 42% I 01 15

I 1 CONFORT HEATINQ 39780 40556 41853 27314 8107 7690 6871 7211 I 28924 29831 35U36 38011 311793

(td.1) I 1

I US GYPSUM PROCESS" 61473 76807 90134 I 80102, 8- I 44036 97401 101T14 63319 75124 I 71705 I 862015

TABLE 2-2 PEAK HEAT LOAD SUMMARY BOWLINE STATION

MONTHLY BTU DAYS IN PEAK FURN BTUMR PEAK FACILITY PEAK EOUlV MONTH ~ 10*6BTURtR EFF PERGPM GPM

CALCUATION OF PEAK HOT WATER REQUIREMENTS TO EACH FACILITY BASE ON 250 F SUPPLY AND 160 F RETURN USING AVERAGE OF PEAK MONTH HEAT LOAD FOR HOURLY RATE 1 GPM AT 250 F TRANSFERS 42283 BTUMR OF HEAT ASSUME CUSTOMER FURNACE EFFICIENCY - 75%

ORANGE & ROCKLAND UTILITIES SWEC JOB 03777

PIPE SIZE FLOW TEMP. OF FLUID PIPE SCHED

TABLE 2-3

IN I 8 10 12

F I 650 650 650 W H R 1 60000 60000 60000

40 40 40

STEAM PIPE SIZING FROM BOWLINE STATION TO U.S. GYPSUM CORP.

PIPE ID SPlCIFlC VOLUME FLUID VISCOCITY FLUID VELOCITY RENOLDS NO.

IN I 7.98 10.02 12.00 CU.R./LB 1 1 360 1.960 1.960 CENTIPOISE 0.01 7 0.01 7 0.01 7 RfSEC 94.05 59.67 41.60

2.79Ei06 2.22Ei06 1.86E+06 FRICTION FACTOR I 0.0144 PDROP PSI/l OOFT 1.055 TOTAL PDROP 1 PSI 72.839

0.0139 0.0136 0.327 0.1 30

23.935 10.027

[TOTAL EQUIVALENT LENGTH I 6906.13 I 7321.58 I 7725.00 1

uu STRAIGHT PIPE Fr. 5280 5280 5280 L.R. ELBOW 14 60 60 60 L.R.45 ELBOW 14 THROUGH TEE 20 BRANCH TEE 60 10 10 10 GLOBE VALVE 340 2 2 2 BU’lTERFLY VALVE 45 GATE VALVE 13 25 25 25 CHECK VALVE 100 ENTRANCES .5/F W n S 1 IF NO. OF REDUCERS REDUCER SIZE OUTLET

NO. OF ENLARGERS I ENLARGER SIZE OUTLR ENLARGERS K O.OO0 O.OO0 0.000 MISC. UD I I

REDUCERS K 0.000 1 O.Oo0 O.Oo0

[MlSC PRESS DROP I PSI I I 1 I

L 0 z

d

L I

8

: utuu

ORANGE & ROCKLAND UTILITIES DISTRICT HOT WATER HEATING SYSTEM SWEC JOB 03Tn

DISTRICT HEATING(DH) HEAT EXCHANGER

TABLE 2-5

$65,000

COST ESTIMATE FOR POWER PLANT MODIFICATIONS BOWLINE POINT

I .PRESSURIZING PUMPS $5.000

D.H. CIRCULATING WATER PUMPS $23,000

I

10. H. EXPANSION TANK I S56.000 f

MAKE-UP WATER SOFTNER $1 5,000

ELECTRICAL INSTALLATION $1 00.000

1

]PIPING VALVES 8 INSULATION I S150.000 1

I LDISTRICT WATER PIPING (SHOWN ON TABLE 9) I $3,995,573

I PIPING 8 EQUIPMENT INSTALLATION $200,000

I I

tlNSTRUMENTATION 8 CONTROLS I s1oo.o0O 1

IBACK UP BOILERS I $260.000 1

1 SUBTOTAL 1 $4,969,573 1 CONTINGENCY 25% I $1,242,393

I I

ENGINEERING 15% 1 $745,436

I TOTAL I $6,957,402 1

BOWEST.WK1

,---

CLIENT - Orange & Rockland Utilities, Bowline Point Station District Heating Study DESCRIPTION OF WORK - Steam and Condensate Piping From Bowline Point Staion to U.S. Gypsum Corp.

ESTIMATE NO. J.O. NO. - 03777.00 SHT 1 OF 1 QTV BY - SWEC CHECKED BY - SWEC PRICES BY DATE 01 /I 8/92 APPROVED

BOWSTM.WK1

TABLE 2-6 PIPING COST L @MATE FOR STEAM LINE BOWLINE

ACCOUNT‘ UNIT COST NO. DESCRIPTION QUANTITIES UNITS MAT’L ‘MH’S RATE MATERIAL

2000 Excavation (note 1) 33000 cy 3.00 0.08 56.00 $99,000 2100 Backfill (note 1) 25000 cy 1.50 0.05 56.00 $37,500 2200 Remove existing road (note 1) 666 sy 1.50 0.05 56.00 $999 2300 Repair of Existing Road 666 sy 5.00 0.10 56.00 $3,330 2400 Topsoil and seeding 13600 sy 0.15 0.04 56.00 $2,040 2500 Sandbed 1520 cy 3.50 0.16 56.00 $5.320

$3,750 2600 Concrete Anchors 25 cy 150.00 5.00 56.00 2700 Steam (loa) & Condensate Piping (4”) 16400 11 150.00 1.20 56.00 $2,460,000 2700 Allowance for expansion loops 2460 ft 150.00 1.20 56.00 $369,000 2800 Manholes 33 ea 2000.00 8.00 56.00 $65,600

---------- Sub-total Cost $3,046,539

$761,635 Contingency (25%)

$3,808,174 TOTAL COST

1. The material costs include Note: equipment rental and operating costs.

PLANT

LABOR TOTAL MAN-HOURS

$147,840 $246,840 $70,000 $107,500 1250

$3,730 $7,060 67 $30,464 $32,504 544 $13,619 $18,939 243

1 25 $1,102,080 $3,562,080 19680 $165,312 $534,312 2952 $14,694 $80,294 262

$1,865 $2,864 , 33

$7,000 $10,750

.P

$1,556,604 $4,603,143

$389,151 $1,150,786

$1,945,755 $5,753,929

-- P

CLIENT - Orange & Rockland Utillies ESTIMATE NO. J.O. NO. - 03777.00 SHT 1 OF 1 DESCRIPTION OF WORK - District Heating Hot Water Piping From 80Wlne Station QTY BY - SWEC CHECKED BY - SWEC PRlCES BY

I

ACCOUNf UNIT COST NO. DESCRIPTION QUANTITIES UNITS MAT'L I MH'S RATE MATERIAL LABOR TOTAL MAN-HOURS

2000 Excavation (note 1) 60724 cy 3.00 0.08 56.00 $182,172 $272,044 $454,216 4858 21 00 Backfill (note 1) 45543 cy 1.50 0.05 56.00 $68,315 $1 27,520 $1 95,835 2277 2200 Remove existing road (note 1) 500 sy 1.50 0.05 56.00 $750 $1,400 $2,150 25 2300 Repair of Existing Road 500 sy 5.00 0.10 56.00 $2,500 $2,800 $5,300 50 2400 Topsoil and seeding 39167 sy 0.15 0.04 56.00 $5,875 $87,733 $93,608 1567 2500 Sandbed 3264 cy 3.50 0.16 56.00 $11,424 $29,244 $40,668 522 2600 Concrete Anchors 25 cy 150.00 5.00 56.00 $3,750 $7,000 $10,750 125 2700 Piping - 12" 6000 ft 59.34 0.18 56.00 $356,013 $60,480 $416,493 1080 2700 Piping - 10" 25500 ft 47.80 0.18 56.00 $1,218,798 $257,040 $1,475,838 4590 2700 - Piping - 8" 4000 ft 34.71 0.18 56.00 $138,852 $40,320 $179,172 720 2700 Piping - 6' 22700 11 24.93 0.18 56.00 $565,843 $228,816 $794,659 4086

2700 - 6pmg *- --- - 3" 3500 ft 14.55 0.18 56.00 $50,936 $35,280 $86,216 630 2700 Piping .---- - 2" 1600 ft 11.20 0.18 56.00 $17,926 $16,128 $34,0541 288

2700 Piping - 4" 7200 11 18.62 0.18 56.00 $134,039 $72,576 $206,fi5 1296

-----_---

Sub-total Cost $2,757,191 $1,238,382 $3,995,573

Con~~ngency (25%) $689,298 $309,595 $998,893

TOTAL COST

1. The meterkit costs include

- ~ _ _ _ - $3,446,489 $1,547,977 ~ $4,994,466

Note: equipment rental and operating

1 costs.

~.

,

-1

TURBINE

r- I I I I i I I I I I I t

CON DEN 5 ER

HOT V A l C R

---------

I I I

t-----U- I I I I

iu

I k I I r----- 1

Il/2'

I 2' c I DISTRICT HEATING VATER CIRCULATING PUMPS PRESSURIZING PUMPS

I -- BDWLINC UNIT 2 POWER STA. 4

D I S I R I C l HEATING POVER PLAN1 W E l R O f l T SCHEMATlC

3 1

flRAFlGE 1 ROCKLAND UTiLIT1ES 1 1 m u I WICIpIKN

STONE b WEBSTER ENGlNffRfNC CORP ?LG* 03 7 7 7 -Pi - SK -2- 1

K A Y FRIES I N ~ U S T R I ~ L PARK

ROUTE 9 W . .

Time Square Lighting

Q.E.P. Co.

Stony ?oint

E lec t ron ics . -

!I Gothom Ink

r ! i Diplomat Juvenile i

L L

x 5 L

Lighting Services

Inco rpo ra ted

SECTION 3