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This report was prepared as an account of work sponsore<i hy the United States Government. Neither the United States nor the United States Department of Energy, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes an y warranty, express or implied, or assumes any legal liability or responsibility for the accuracy , completeness or usefulness of any information, apparatus, product or process dis closed~ or represents that its use would not infringe privately owned rights.
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A COMPARISON OF DOE-2 AND TRNSYS SOLAR-HEATING~SYSTEM SIMULATION ,,
ANTHONY EDEN -MARION MORGAN
DECEMBER 12.80.
PREPARED UNDER TASK No~ 3525.11
_Solar Energy Research Institute. A Division ot'Midwest Research Institute
161°7 Cole Boulevard Golden. Colorado 80401
Prepared for the U.S. Depa_rtment of Energy Contract No. EG-77-C-01-4042
, ..---"-------- DISCLAl"1ER -
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... ..
This book was prepared as an account of work sponsored by an agency of the United Slates Governmeni, U.:iU·~r U11l U11itl.J Otata, Oi.,,c,11111c11\ 1iu1 1111v c,p111.y 1l1eieul,1n.r, oi1v ul d1islr 11m~luyw:ii., 1tlillr..11Sc111y warranty, e,cpress or implied, or assumes anv legal llablllly or responsibilhv for the accuracy, completeness, or usefulness ot any information, opparatus. product, or process dlsclosed, or represents that Us use would not Infringe prMnolv owned rights. Roference herein to any specific commerclal produCI, process, or service by trade name, tradomarlc, manufac1urer, or otherwise, does not necessarily constitute er imply hs cndcrsement, reeommenda1lcn, er f11YCring by the United States Government er inv agency lherecf, The views and opinions cf authors expressed herein de nc1 ltV.l.l.aJUlll, Ji11it1 U1 1elle1,,11hu1e1,1/ 1111, U11hei.J lLdLe~ OUWIIIIIIVlll lJI illlV ill,Jllm.:y 11n11wi,
. rilSTn/OUTION OF THIS nocUMENT IS UNUr,tJ ED
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FoREWoRD
The purpose of this study was to assess the applicability of the DOE-2 computer simulation prograni to the analysis of active solar , heating and cooling systems for buildings. This is part of a larger effort to develop a building simulation code that would allow analysis of active and passive solar and building energy conservation measures in a combined way. The DOE-2 code was a prime candidate because of its designation by the U.S. Department of Energy as the Standard Evaluation Technique· for the Building Energy Performance Standards Program.
This research was sponsored by the U.S. Department of Energy, Office of Buildings, Active Solar Heating and. Cooling Systems Division, ·under ·SERI .FY 1980 task number 3525.11, Integrated Active/Passive Design Tool. The work was performed in the Systems An.alysis Group of the Building Systems Development Branch.
Lyle oome, Acting Manager Systems Anaiysis Group
Approved for
SOLAR ENERGY RESEARCH INSTITUTE
Branch
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ACKNOWLEDGEMENTS
The authors would like to acknowledge the efforts of David Simms and John V. Anderson in assisting in the computer simulations and programming research involved with this study. Their expert knowledge proved invaluable in the operations of the computer
,, located at SERI and the program techniques employed w;f...th the major program elements.
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1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
TABLE OF CONTENTS
Introduction •••••••••••••••••••••••••••••••••••••••••••••••••••••••
General Description of the Programs ••••••••••••••••••••••••••••••••
Descripti·on of CBS ••• ••••••••••••••••••••••••••••••••••••••••••••••
Description of the System Modeled •••••.••••••••••••••••• ~ •••••••••••
Plan of Project . .•.. -~ ••••••.••.•••••••• ~ ......• • ••••••••••••••••••••
Input Requirements and Comparisons •••••••••••••••••••••••••••••••••
Comparison of DOE-2.1-CBS and TRNSYS- 10._l Simulations ••••••••••••••
Comments arid Recommendations •••• ~ ••••••••••••••••••••••• , ••• ·• ••••••
Conclusions ••••••••••••••••••••••••••••••••••••••••••••••• ~ ••••••••
References ••• ••••.•••••••••••••• · •••• • •••••••••••••••••••• • • • • • • • • •·•
1
3
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11
15
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39
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43
Appendix A DOE-2.1 Input Card Images••••••••••••••••••••••••••••••••••••• 45
Appendix B TRNSYS 10.1 Input Card Images••••••••••••••••••••••••••••••••• 51
Appendix C DOE-2.1 and TRNSYS 10.1 Data Comparisons ••••••••••••••••••• ~.. 55
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2-1
3-1
3-2
3-3
3-4
4-1
4-2
5-1
LIST OF FIGURES
DOE-2 Program Outline ••••••••••••••••••••••••••••••••••••••••••••••
Collector System Model•••••••••••••••••••••••••••••••••••••••••••••
Storage Tank Model ................. -•• _ •••.• ~ •••••••••••••••• · ••••.••••
Commercial Distribution System Model ••••• · ••••••••••••••••••••••••••
Residential Distribution System Model ••••••••••••••••••••••••••••••
TRNSYS Liquid Collector-Storage Subsystem ••••••••••••••••••••••••••
TRNSY'S Energy/.(Degree-Hour) Space Heating •••••••••••••••.•••••••••••
Collector Efficiency Curves •••••••••••••• ~•••••••••••••••••••••••••
7-1 Total Monthly Insolation Calculated by DOE-2.1 and TRNSYS 10.1
4
8
8
9
9
12
13
18
for Madison • •••••••••.• ~ • • • • • • • • • • • • • • • • • . • • • • • • • • • • • . . . . • • • • • • • • 24
7-2 Total Monthly Heating Load Calculated l5y DOE-2.1 and TRNSYS 10.1 for Building in Madison •.•••••••••••••••.••••••••••••••••••••••• :.. 25
7-3 Annual Average Part Solar and Annual Average Collector Efficiency Calculated by DOE-2.1 and TRNSYS 10.1 for Madison with FRTa = 0.780, FRUL = 20.44 kJ/h-m2- 0 c....................... 26
7-4 Annual Average Part Solar and Annual Average Collector Efficiency Calculated by DOE-2.1 and T~~YS 10.1 for Madison with FR Ta = 0. 705, FRUL = 1_8.13 kJ/h-m - C....................... 27
7-5 Annual Average Part Solar and Annual Average Collector Efficiency Calculated by' DOE-2.1 and Tr,~YS 10.1. for Madtson with FRTa = 0.643, FRUL = 17.99 kJ/h-m - C••••••••••••••••••••••• 28
7-6 Annual Average Part Solar and Annual Average Collector Efficiency_ Calculated by_ DOE-2.1 and T~~YS 1.0.1. for Madison with FRTa - Q.780, FRUL - 26.98 kJ/h-m - C••••••••••••••••••••••• 29
7-7 Average Part Solar and Average Collector Efficiency Calculated by D0~-2.1 and TRNS:S ~0.1 for Fe~r~ary for Madison with FRTa - 0.780, FRUL - 20.44 kJ/h-m - C•••••••••••••••••••••••••••• 32
7-8 Average Part Solar and Average Collector Efficiency Calculated. by DOE-2.1 and TRNSYS 10.1 for Fe~r~ary for Madison with · FRTa = 0.643, FRUL = 17 .99 kJ/h-m - C............... •.• • • • • • • • • • • • 33
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LIST OF FIGURES (concluded)
7-9 Average Part Solar and Average Collector Efficiency Calcula:ted by DOE-2.1 and TRNSYS 10.1 for De~e!ber for Madison with FRT~ = 0.780, FRUL = 20.44 kJ/h-m - C•••••••••••••••••••••••••••• 34
7-10 Average Part Solar and Average Collector Efficiency Calculated by DOE-2.1 and TRNSYS 10.1 for 1>e~e!ber for Madi"son ·with . FRTa = 0.643, FRUL = 17.99 k.J/h-m - C•••••••••••••••••••••••••••• 35
7-11 Annual Average Part Solar and Annual Average Collector Efficiency Calculated by DOE-2.1 and TRNSYS 10.1 with Collector Flow Varied....................................................... 36
7-12 Annual Average Part Solar and Annual Average Collector Efficiency Calculated by DOE-2.1 using TRY and TMY Weather Data for Bismarck ..••••••••••••••••••••••.. ~ .•...•.•••••.. -........ 37
C-1 Total Monthly Insolation Calculated by DOE-2.1 and TRNSYS for a) Madison, b) Dodge .City, c) Omaha, and d) Bismarck.......... 57
C-2 Annual Average Part Solar and Annual Average Collector Efficiency Calculated by D2E-2. l and TRNSYS 10_. l with F RTa = 0.780, FRUL = 20.44 kJ/h-m -°C for a) Madison, b) Dodge · City, c) Omaha, and d) Bismarck................................... 59
C-3 Annual Average Part Solar and Annual Average Collector Efficiency Calculated by D2E-l.1 and TRN8Y8 10.1 with i,·RTa = 0.705, FRUL = 18.13 kJ/h-m -°C for a) Madison, b) Dodge City, c) Omaha, and d) Bismarck................................... 61
C-4 Annual Average Part Solar and Annual Average Collector Efficiency Calculated by D2E-2.l and TRNSYS 10.1 with FRTa = 0.643, FRUL = 17.99 kJ/h-m -°C for a) Madison, b) Dodge City, c) Omaha, and d) Bismarck.................................... 63
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Page
3-1 Example of Monthly and Annual Summary Output of DOE-2.1-CBS......... 10
5-1 Climate and Insolation Zones of Selected Cities...................... 16.
5-2 Collector Selections................................................ 17
6-1 DOE-2.1 and TRNSYS 10.1 Input Comparison ••••••••••••• ·••••••••••.••••• 20
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S:fl 1r=)1 _______________________________ T_R-_8_2_2_ '-==-/
SUMMARY
This paper discusses the Solar Energy Research Institute's (SERI) analysis ·and comparison of the output of the solar energy simulator of DOE-2 and TRNSYS. DOE-2 is a public domain computer program that allows users to explore the energy-use patterns of existing and proposed buildings, and their heating, ventilating, and air conditioning (HVAC) systems. This. program contains a· solar energy s:l,mulator called Component Based Simulator (CBS) that :,Js incorporated into the HVAC Plant (large equip111ent) section. SERI researchers investigated the adequacy and sensitivity of the DOE-2 solar simulation when various active solar_ energy -collectors were interfaced with a standard space heating system. The results of these computer runs are compared to the results of simulations with the same systems and components using TRNSYS.
The analysis by SERI included _both single- and double-glazed collectors with selectively and nonselectively coated absorbi~g surfaces. A typical thermal load for a commercial building model was chosen to allow comparison of the performance of solar energy systems while using a constant thermal demand. The researchers simulated four locations with varying weather parameters and insolation levels to test- the programs' abilities _to accurately predict performance in different environments. The two programs were also evaluated by comparing the results of varying selected parameters such as collector area and flow rate.
The results of the SERI study show good agreement between the output of DOE-2.1 and TRNSYS 10.1 using a heating load. Values calculated by the two programs are remarkably similar. Graphs are presented to illustrate the minor differences in annual average collector efficiency and annual average part solar (solar contribution to satisfying the thermal demand) as well as the thermal load and insolation levels. In addition, difficulties encountered by the researchers when performing· this study and when attempting t;o model the collector systems with each program's components are discussed and r~commendatiom: are offered. to facilitate the solar simulation process for future CBS users.
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SECTION 1.0
INTRODUCTION
. The U.S. Department _of Energy (DOE) has been developing a computer code to model the energy consumption and air conditioning systems designs of proposed structures to provide analysis methods that would help designers reduce the building energy consumption and to furnish an evaluation tool for the Building Energy Performance Standard (BEPS). Development work on the computer program, DOE-2, has peen funded by. DOE at Lawrence Berkeiey Laporatory (LBL) and Los Alamos Scientific Laboratory (LASL) (Building Analysis Group 1979). Included within DOE-2, the Component Based Simulator (CBS) deals with the possible solar energy subsystems of such structures.
Because DOE-2 is designated as the Standard Evaluation Technique (SET) for BEPS, ~n independent evaluation of its accuracy and capability is needed. SERI researchers approached this task from the perspective of a potential user of DOE-2.1 who would use the code mainly for building energy analysis and include solar energy systems as part of the energy supply. The goal of the investigation was to exercise. the program with a heating system that such a user might select. This choice limited the possible computer function utilizations to a relatively simple system ·with standardized components. Systems and components were used that reflected a logical first selection of a user. who was not necessarily familiar with all types of solar energy systems but willing to try a few to see their effects. The researchers did not use the entire capability of DOE-2.1, especially the Plant section. Heating was the only application investigated using sites at which it was required. The goal was to build user confidence in the program's abilities t·o simuiate the systems accurately without requiring a computer expert.
This paper presents SERI's investigation of CBS as a stand-alone computer pro-'gram in comparison with TRNSYS 10.1, a well-investigated solar program generally accepted by the solar community as a comparison standard (Klein et al. 1979). In addition, the report briefly describes the large DOE-2.1 program and some of the CBS components and makes recommendations for documentation changes · and for use of. the program. The results of the evaluation are presented showing the levels of agreement between the two programs.
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SECTION 2.0
GENERAL DESCRIPTION OF THE PROGRAMS
This section describes the two computer programs used during this investigation. TRNSYS was selected because of its reputation as the standard against which most other solar simulation codes are compared. TRNSYS is a program for simulating the dynamic thermal behaviors of active heating and cooling systems. It is based on a modular approach whereby the user specifies which components comprise the system and the manner in which they are connected. The components include collectors, controls, storage tanks, heat exchangers, furnaces, and building loads, as well as combinations into common subsystems. Inputs and outputs from the component· subroutines correspond to inputs and outputs of the modeled hardware. Building heating and cooling loads may be calculated by the degree-day method or by using- input response factors, or they may be input from another model. Card image records of hourly weather
. data are required. Output data include heating loads, energy use by various system components, auxiliary energy, and other systems thermal energy balances for error checking (SERI 1980, p. 14).
DOE-2 is a large computer program primarily designed to aid the architect and mechanical engineer in evaluating the performance of air conditioning systems and exploring the energy behavior of new and proposed buildings. The version of the code being tised at SERI 1is DOE-2.1 (Building Energy Analysis Group 1980). At the time of the investigation the code was frozen but the documentation was in draft form. · The Program Manual, a frequent reference for additional information, was not available. LBL and LASL are performing formal research into the operations and continued development of DOE-2 (Raschke et al. 1978). As part of the inquiry into all solar analysis methods, SERI investigators are exercising the computer program using a copy of the code on the SERI CDC 7600 computer. They are scrutinizing the solar energy aspects of DOE-2 and CBS because the program is being emphas·ized as a design tool and · evaluation method. SERI is also investigating many other solar energy computer codes to be included in SERI's Solar Models Data Base.
DOE-2 is a very powerful computer code, capable of analyzing many different heating, ventilating, and air conditioning (HVAC) systems over a· full year. The. simulations of DOE-2 are mostly directed . at the HVAC loads, systems, plant, and economics as illustrated by the major portions of the program shown in Fig. 2-1. As one can see in this simplified diagram, DOE-2 consists of five major programs, the first of which is the Building Design Language (BDL) Processor with its material and weather libraries. Three groups of weather files are available: TRY (ASHRAE Test Reference Year), California (one year of data for each of 15 climate zones in California), and TMY (Typical Meteorological Year) (Building Energy Analysis Group 1980). Since DOE-2 was designed to allow simplified entry of the many variables needed to describe a building and its operation, BDL is necessary to analyze the user input instructions and to control subsequent simulation portions of the program called Loads, Systems, Plant, and Economics (LSPE). After the BDL processor has prepared the input for the program, data ar.e sent to all the other elements that are used sequenti~lly through the process of computer overlays.
3
BDL Loads ( · Input Data .... 0 1/1
Material 1/1 Q.).
Library u 0 .....
Ct. 1/1 ....J 1/1 H::>Urly E Modified Cl "O . Q.l co - Hourly co 0 Data 1/1
....J >, Da1a Weather Cl)
Library
Figure 2-1. DOE-2 Program Outline
1/1 u - Plant E C
Cost 0 co C
Ct. Information 0 u w
UI Ill .IIIU -11-1 I
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Within the LSPE_construction of DOE-2, Plant, which contains GBS, is the focus of the SERI investigation into the program's active solar energy system-simulation capabilities (Eden and Simms 1980). Other research at SERI is studying the passive solar aspects of Loads and Systems. Within Plant, CBS is attached to the energy supply simulation allowing solar energy to be used as if it were another conventional energy source. As the HVAC data are passed to Plant from Systems through the Modified Hourly Data as shown in Fig. 2-1, one can program Plant to meet the energy demand most efficiently, which may include the use of available solar energy if CBS systems are programmed into the Plant option.
Investigation of CBS through Plant, while tied to the main program, can be very time consuming and expensive; however, once a sample structure has been modeled and run through DOE-2, the Systems output can be stored in a separate file for direct use by Plant. Therefore, one can accomplish later runs that involve changes only in CBS· by running Plant alone and by using previously saved Systems data files as input. Also, one can examine the reports from Loads and. Systems for the HVAC load characteristics and these can be. modeled separately to produce a file containing hourly loads. Both of these filecreating techniques allow one to use CBS in a stand-alone mode without needing to execute the entire DOE-2 program, thus saving time and money. One may use the degree-day simulator component available in CBS to perform the heating load calculations anc;l to allow a parametric study of the code without using the main DOE-2 program.
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S:~I '*' _______________________ T_R-_8_2_2_
SECTION 3.0
DESCRIPTION OF CBS
The CBS portion of DOE-2.1 consists of many modeled active solar energy compo·nents designed to permit ·easy assembly into various liquid and air configurations. This code structure allows flexibility in the solar energy systems design when the subsystem is still conceptual. SERI investigation of CBS is extensive, but only a few example components will be discussed (see Figs. 3-1, 3-2, 3-J, 3-4). CBS contains many more components than just these few illustrations, including many preconnected into subsystems (Building Energy Analysis Group 1980). Figure 3-1 shows a collector model component consisting of four smaller components programmatically connected into this configuration. Employing the procedures in CBS, the programmer can either use these connections of collecto~, relief valve, pump, and heat exchanger models or can choose to further divide the system into individual components if more detail·and flexibility is desired. One should refer to the CBS documentation (Building Energy .Analysis Group 1980) for a complete description of the possible combinations and configuratio~s available in the computer program.
Figure 3-2 shows the fully mixed, unstratified storage tank component included in the DOE-2.1 version of CBS. As modeled in the figure, the fully mixed tank receives _the output energy data fro~ the collector model and simulates the reaction of a storage tank to that energy. Th~ storage tank component then passes _output data to one of the selected HVAC subsystems. Figures 3-3 and 3-4 show two possible configurations for these subsystems--one designed pri.;. marily for a commercial building and the other for a residence. As one can see . in Fig. 3-3, the . commercial system offers the designer several options when selecting the heating coil connections within a HVAC system. Also shown are the connections for an auxiliary system and a fresh air makeup. The residential system. in Fig. 3-4 has the necessary connections for an auxiliary energy system and models a common configuration.
Once the solar energy system is configured by the selection and assembly of the compone_nts, the programmer chooses which CBS components to use as the controller, insolation model, report format, and load simulator. As discussed previously, the load c~n come from a file created by a run of a DOE-2.1 sample, from a file of loads from any hourly simulation . program, or from a degree-days load calculator. The entire program is then run for a complete year, and the results are available for study or- comparison to other designs or other programs.·
An example of the monthly and annual summary out~ut of CBS is shown in Table 3-1. For this run, the collector. area is 380 ·m of nonselective singleglazed panels located in Madison, Wisconsin; the storage tank volume is 30.4 m3 of water; and the ethylene glycol-water mixture flow rate through the collectors is 9120 kg/h. The pump power is.set at 1 kW so that the electric load is also the number of hours the collector and heat exchanger pumps are on.
7
S5ill 1 --
To Tank
Heat Exchanger
'------1111f---..;...._---' .__....., __ From Tank
Figure 3-1. Collector System Model·
From Collector System ---
To Collector .... _ _,,,, System
To Distribution --· System
.Fully-mixed Storage Tank.
From Distribution ...._....,_ System
Figure 3-2. Storage Tank Model·
. .
• Source: Building Energy Analysis Group, DOE-2 Version 2.1, Draft, Energy and Environment Division, Lawrence Berkeley Laboratory, California, March 1980.
TR-:-822
5:11 ----·
Fresh Air-::£, t• Return
Air
From Tank :J---,w..-.. To Aux. 14--- From Aux.
To Tank.__....,
. Reheat Coil
1~1 Supply
Air
Figure 3-3. Commercial Distribution System Model1
--- From Aux.
To Tank--.... --• To Aux.
~-1 lt~I ~-----Auxiliary
Heating Heating Return· Coil Unit
Air
Figure 3-4. Residential Distribution System Model·
Supply l Fan
,Supply 0'Air
TR-822
( .
: *. Source: Building Energy .A.nalysis Group, DOE-2 Version 2.1,· Draft, Energy · and Environment Division, Lawrence Berkeley Laboratory, California,
March 1980.
9
Table. 3-1. EXAMPLE OE' MONTHLY AND ANNUAL
Total Total To~al Total A•erage Ma.ximum Incident Collected Hea·:ing Solar Storage Storage
Energy Energy Lead He:tting '.:e.11p. Temp. (MRtu: (MR tu:• (ME tu) (MRtu) ("F) ( ;F)
Jan 110.44) 31.360 47 .430 32.727 !!7.6 123.3 Feb 126.830 35.55'.i 38.906 32.155 93.8 137.2 Mar 186.433 41. 28! 35.618 35.451 ]44. 6 178.1 Apr 16H. l72 22.39<1- 16.359 · 16.359 JE9.5 189.8 May 187. 359 15.790 8.824 8.824 117. 2 195.3 ....
0 .Jun 191.819 9.045, 3.440 3.440 JSO. l 201.8 ,Jul 207.372 7.029 1.499 1.499 1S2. 3 200.7 Aug. 209.632 9.359 3.321 3.321 IS 1.4 198.9 Sep 18l.:B6 9.900 5.640 5.640 JE8.4 196.2 Oct 143.296 18.62:3 13.979 13.979 I, 1.0 186.7 Nov 98.385 21. 14·~ 26.677 25.058 · 1~3.5 186.6 Dec 79.47'!. 26.05~ 38.827 24.533 E3. 7 112.9
--·--TOTAL 1891.046 . 247.53~ 240. 520 202.986 !~-1.4 201.8
'·
SDMHARY <lJTPU.: or· DOE-2.1-:::SS
Minimum Avera~e ANerage. Storage C,Jllector System
Temp. Ef::. EU. c•i,) (?.) (%)
69.9 28.4 '!.9.6 71.1 28.0 '!.5.4 81. 5 22. ! .9.0
138.3 13.:3 9.7 132.4 8 • .- 4.7 178.0 4 • ., 1.8 180.9 3. ~ 0.7 180.6 4. 5 1.6 175.5 5. ~ 3.1 139. 7 13.) 9.8 · 74. 2 21.5 ~5.5
70.9 32.3 30.9
69.9 13.l L0.7
Average Average Solar
Part Building Solar Load
(%) Ratio
69.0 2.33 82.6 3.26 99.5 5.23
100.0 10.28 100.0 21.23 100.0 55.76 100.0 138.35 100.0 63.12 100.0 32.24 100.0 10.25 93.9 3.69 63.2 2.05
84.4 7.86
Total Solai;-Elec. Load (kWh)
110.0 125.0 130.0 92.0 ()O.O 73.0 66.0 70.0 68.0 86.0 86.0 89.0
1085.0 ·
UI Ill .141 -II II
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S:~l 1fl1 _________________________ T_R_-_8_22_.
SECTION 4.0
DESCRIPTION OF THE SYSTEM MODELED
The system modeled for comparing CBS, the solar part of DOE-2.1, with TRNSYS 10.1 is a commercial building with liquid solar collectors circulating a mixture of water and ethylene glycol; heat exchanger; fully mixed water storage tank; and single coil air distribution system, in a·heating mode. The building, which has an area of 465 mz (5000 ft 2), is patterned after Sample 3A from the DOE-2.1 Sample Run Book (Building Analysis Group 1979). Sample 3A is a one story, simple structure with windows and doors on the 2.4-m (8-ft) insulated wooden frame walls. _The sola-r collector arrays are mounted on the flat, built-up, wooden frame roof which is insulated with 5 cm (2 fn.) of pre-formed insulation. The lighting is recessed flourescent at 32 W/m. The mechanical equipment consists of a variable air volume system with insulated ducts, temperature-controlled economizer cycle, and a variable speed fan. After Sample 3A was run using the entire DOE-2.1 program, the output was analyzed and a simple model developed to be used with CBS. TMY weather data tapes provide. insolation information for calculation of energy i11cident on the collectors. The building energy load is the difference between the energy required based on the number of degree-hours (an· extension of the degree-day concept to hourly data) and the scheduled internal heat generation. The auxiliary heating . supplies only that part of the load which cannot be extracted from the flow stream from the solar storage tank.
Initially the researchers modeled the system using DOE-2.0A, an earlier version of DOE-2 and the only version available when the project started. The selection of Sample 3A and the solar energy subsystems was made to provide compatible input to DOE-2.0A and TRNSYS 10.1 to minimize computing costs and to be representative of ·a simple system that might be used by someone with minimal computer experien_ce. The second set of runs was performed with. TRNSYS 10.1. Finally, the DOE-2.1 program was used to simulate the selected systems and loads.
The DOE-2.1 model of the system consists of Type COL:-EC-1 (for collector efficiency curve) (Fig. 3-1), Type TANK-1 (Fig. 3-2), and Type CLSH-CNTRL-1 (for. commercial liquid space heating controller) (Fig. 3-3). The weather reading component is Type DOE-WEATH-1, the insolation calculation component is Type INSOL-1, and the loads calculation component is Type DEG-DAY-LOADS-1. The DEG-DAY-LOADS-1 component of CBS was in the 2.0A version but does not appear in documentation of DOE-2.1; however, it is still i.n the code.
The TRNSYS 10.1 model of the system consists of Type 21, Liquid CollectorStorage Subsystem (Fig. 4-1) and Type 12, Energy/(Degree-Hour) Space Heating, mode 1 (Fig. 4-2). The weather reading component is Type 9, Data Reader; thP. insolation calculation component is Type 16, Radiation Processor, mode 5; and the loads schedule component is Type 14, Time Dependent Forcing Function.
11
S:fl ,If,. -,---------------------____;;TR:.;;...-==.=822
Pump
,----,----
Heat Exchanger
)
Relief Valve
------Pump
Main Storage
Tank
Figure 4-1. TRNSYS Liquid Collector-Storage Subsystem Source: S. A. Klein et'al., TRNSYS, A Transient System Simulation Program, Solar Energy Laboratory, University of Wisconsin, June 1979.
'
12
S:.fl 1if1 _______________________ TR_-_8_2_2
'
~--.-----------1 I I I I I Heated · I I Space Auxiliary · I I I I I ________ J I I . . · . I L __ . ----" ____ _J
Figure 4-2. TRNSYS Energy/(Degree-Hour) Space Heating, Source: S. A. Klein et al. TRNSYS, A Transient System Simulation Program, Solar: Energy Laboratory, University of Wisconsin, June 1979 ..
13
S:fl ,., _____________________ T_R_-8_2_2 - ~ = 7
SECTION 5.0
PLAN OF PROJECT
When approaching the problem of comparing DOE-2.l with TRNSYS 10.1, the authors decided to employ the perspective of a user of DOE-2.1. This hypothetical user would not be sufficiently versed in computer programs and simulations to use TRNSYS, yet would be motivated enough to attempt to use ·solar energy systems in conjunction with DOE-2.1, possibly with BEPS emphasis. This person would tend to choose a simple system for a model in DOE-2.1 and observe the results. Next, this user might try a few variations to the initial or default values and then proceed with other work.. In view of these considerations, the researchers chose a simple system that could be modeled by both programs but did not necessarily use all the functions available to an experienced programmer. With this outlook, the authors did not go beyond a simple collector model; a 'single node, fully mixed storage tank; and an uncomplicated scheduling of loads and controls.
Four cities were selected for the comparison of DOE-2.1 with TRNSYS 10.1, based on availability of TMY weather data and differing combinations of insolation and temperature regimes as shown in Table 5-1. The cities selected were Madison, Dodge City, Omaha, and Bismarck. These cities were all characterized as probably requiring a substantial amount of heating energy yet offered varying amounts of insolation on a broad scale.
In each- of the four cities, three types of flat-plate collectors were modeled and are listed in Table 5-2. The value of FRUL recommended by CBS for a single-glazed, nonselective. surface, 1.32 Btu/h-ft2-°F, caused a programming error when used with DOE-2.0A. Therefore, the researchers used 1. 00 Btu/h-ft4-°F. In order to verify that the problem was corrected in DOE-2~1, a fourth collector was modeled with FR,a = 0.780 and FRUL '= 26.98 k.J/h-m2- 0 c (1.32 Btu/h-ft2- 0 F) for Madison. Figure 5-1 presents the efficiency curves for all four collectors.
For each of the col lee tors modeled in each city, the researchers made seven parametri~ runs wit~ DOE-2.1 and with TRNSYS 10.1, varying the collector area from 95 m · to 665 iii aml 8t!L ting the collector flow rate in kg/h at 24. U times the coilector area in square meters, and the storage volume in cubic meters at 0.080 times the collector area in square meters. Similarly, six parametric runs were made for each collector in each city with the collector flow rate varied from 750 t.o · 1200 kg/h and the collector area and storage volume held constant. at 380 m2 and 30.4 m3 , respectively. A set. of area parametric runs were made with DOE-2.1 for Bismarck and a single-glazed, nonselective surface using the TRY weather data to compare the results with those using TMY weather data.
15
-0\
Table 5-1. CLDM.TE AND INSOLATION ZONES OF SE!LECTED CITIES
Location
Madison, WI Dodge City, KS Omaha, NE Bismarck, ND
Cli11.atic Zones Heating (HDD) and Cooling (CDD) Degree-Day
(=>F-:iays)
<2000 Q)D (20•)0 COD (2000 CDD )7000 HOD 5500-700) HDD 4000-5500 HOD
X X
X ~
X
al Langley= 4.186 J/,:.m2•
Inso.lation Level Annual Mean Daily Solar Radiation
(Langleys)a
300-349 350-399 400-499
X X
X X
Ill Ill N --
=~ I I
-
~
' 00 N N
SEfl 1fl, _. ----------------~----TR:_-_8_22
Table 5-2. COLLECTOR SELECTIONS
FRUL Absorbing
Glazing Surface _FRTa k.J/h-m2- 0 c. Btu/h-ft2-°F
Single Nonselective 0.780 20.44 1.00
Single Selective 0.705 18.13 0.887
Double Nonselective 0.643 17.99 0.880
,J
17
-ex:>
· • 780 20. 44
• 780 26. 98
• 705 18.13
• 643 17. 99
1. 0
0. 8
0. 6
', 0. 4
0. 2
0. 0
Cl /Q cc,llec ed inddent
-1 (kJ,h-m 2-° C)
0. 02
Figure 5-1. Collector Efficiency Curves
0. 03 0.04
Ill Ill N ---1 I
-
S:fl 1fl1 _______________________ T_R_-_s2_2
SECTION 6.0
INPUT REQUIREMENTS AND COMPARISONS
This section describes the input decks required to program DOE-2.1 and TRNSYS IO. I to simulate the selected components and systems. The actual inputs are shown in Appendices A and B. The two programs' inputs do not always correspond directly to each other because of internal differences in the codes. These differences and difficulties are discussed. Great care was taken in the process, and the pitfalls as well as suggested improvements in the default values are listed as they affected the simulated systems.
DOE-2.1 requires input in English units while TRNSYS IO. I uses English and modified SI units. - In many respects, the correspondence between the inputs for the two programs is direct. However, in several instances the correspondence requires careful attention to the algorithms and definitions.
Table 6-1 presents examples of part of the input for DOE-2.1 and the corre- . sponding input for TRNSYS 10.1. Most of the problems associated with the input arise from the necessity to match inputs .for the two programs. The more difficult cases are those in which the TRNSYS 10.1 values corresponding to DOE-2.1 are implicit, or internal to the code rather than specified inputs. In two of these cases the difference between the default value in DOE-2.1 and the implicit value in TRNSYS IO.I results in a substantially different average part solar.
First, the heat capacitance of the collector afray per unit collector area, CAP in Type COL-EC-I, is defaulted to 1.0 Btu/ft -°Fin DOE-2.1 and is assumed to be 0.0 kJ/m2- 0 c in TRNSYS IO.I. For the two test runs using these two values in DOE-2, the average part solar is 71.4% and 75.2%, respectively. The researcher~ believe a more realistic default value for DOE-2.1 would be 0.5 Btu/ft -°F, based on experimental values reported by Frederick F. Simon· (Simon 1976, P• 459). Values of collector heat capacitance per unit area are not generally available in manufacturers' literature, so that the default value is critical in this case. ·
Second, th~ mlulmum tempera·ture at which heating fluid from the solar storage tank is supplied to the coil (load heating coil in this case), COIL-T-MIN in Type CLSH-CNTRL-1, has a default value of I20°F in DOE-2.1 and is assumed to be room temperature (68°F in this case) in TRNSYS ·10. I. For the two test runs using 100°F and 68°F in DOE-2.1, the average part solar is 80.5% and 84~5%, respectively. While room temperature would not be a reasonable default value, it is desirable to use the solar energy in the tank at as low a temperature as possible without excessively increasing · distribution system pump and fan energy costs. The researchers believe that consideration should be given to setting the default value at 105°F (Eden and Tinsley 1977, pp. 2-16, 17).
In order to make the collector efficiency curve coefficients in DOE-2.1 have the same effect as FRTa and FRUL in TRNSYS 10.1, it is necessary to set the incidence angle modifier coefficient Bo in DOE-2.1 equal to zero. Ordinarily this coefficient is not provided in manufacturers' literature. It would be desirable for the DOE-2. 1 documentatio11 tu provide more adequate guidance by
19
N 0
Tal,le 6-1. DOE-2.1 and TRNSYS 10.1 INPU1 CXJMPARISON
Building Location
Latitude Longitude Shift
· Time zone Altitude Daylight savings Holiday
Insolation
Tilt
Input
Azimuth (of collector surface) Acceptance Ground reflectance
Load.
UA Maximum scheduled heat ~eneratlonb Constant heat gain Maximum infiltration load Room temperature
Collector-Exchanger-Tank
Area Efficiency coefficients Fluid temp. Incidence angle m,)difier co~f ficient ::s0 FRTa FRUL Collect•::>r to exchanger flow Collect::>r fluid censity Collector fluid specific heat Exchanger to tank flow
42° 88° a
6 860 ft no no
52° 180° 180°
DOE-2.1
(0.2 for each month)
1411 Btu/h-°F 23,695 Btu/h a
0 Btu/h-°F 68°F (scheduled= constant)
4090.3 ft 2 (0.780-1.00 B-:u/h-ft2-°F) inlet (eff. curves based on inlet temp.) 0 a a
area x 0.0994284 gal/min 65.0 lb/ft O. 775 Btu/lb.:_:iF ar~a x 0.0098244 gal/min
TRNSYS. 10.1
42° a
+20 a a a a
52° oo a
0.2
2680 kJ/h-°C 23,750 kJ/h 1250 kJ/h a
20°C
· 380 m2 a a a
o. 780 20.44 kJ/h-m2°c area x 24. 0 kg/h a
3.25 kJ/kg-°C area x 24.0 kg/h
Ill Ill N ---. I I
-
N ......
Table 6-1. DOE-2.1 AND TIUfSYS 10.1 INPUT CXJMPARISON (concluded)
Input
Tank fluid density Tank fluid specific heat Exchanger type Exchanger effectiveness T-boil (relief valve opens) Collector-tank temp. difference to turn
collector on
62.4 lb/ft3 1.00 Btu/lb-°F
DOE-2.1
constant effectivenessc 0.7 212°F l.8°F
Max •. collector temp. allowed by. Initial collector temp.
controller 212°F 40°F
Heat ~apacitance of collector per·unit area (including fluid)
Pump power Tank,volume Tank height to diameter ratio Tank energy loss coef. Initial tank temp.
Auxiliary-Control
. Mode Exchanger type Exchanger effectiveness Minimum temp. at which heatiLg fluid is
supplied to coil Flow through load coils (tank to load) Minimum capacitance rate of load exchanger
(Cair i_n air-water heat exchanger) Air flow through heating coil Specific heat of air
aNo comparable entry. bDefined differently in each cOne of several options. dinternal to program, not an
group.
option.
o.o
1 kW area x 2.0 0.1003 120°F
series
1. 9634 gal
Btu/h-ft2-°F
(constant effectiveness)c (O. 7 ,0. 7 ,O. 7) (68,68,68)°F
(0, 19~82,0) gil/min a
30,716 lb/h 0.24 Btu/lb-°F
TRNSYS 10.1
a
4.19 kJ/kg-°C a
0.7 100°c 1 ocd
a a
o.od
area x O. 08 m3 2.0 2.05 kJ/h-m2- 0 c 49°c
parallel a
0.7 20°cd
4500 kg/h 14,000 kJ/h-°C
a a
TR-822
referring to Simon's paper on collector performance evaluation (Simon 1976, P• 452). Tiiis reference also provides additional guidance on efficiency curve coefficients. The DOE-2.1 recommendation for Bo for mylar honeycomb and one glass cover, -0. 45, is substantially different from that given by Simon, -o. 23. . . 1.
In ·DOE-2. 1 the default value of the collector-tank temperature difference to turn on the collector, DT....;MIN in-Type COL-EC-1, is 1°F. This value leads to high parasitic (pump) costs. For the two test runs using DT-MIN equal to 5°F and l.8°F, the average part solar is 70.1% and 70.2%, respectively, while the total solar electric load is 861 kWh and 933 kWh, respectively. (Units of these latter values are actually hours rather than kilowatt-hours since the pump power was arbitrarily set equal to 1 kW). Setting the default for DT-MIN at 3°F or 5°F would be more realistic and should be considered.
The definition of collector azimuth is different in the two programs, requiring user caution. Irt the 1nsolac1on secr:ion, azimur:h is m~asurla!d fl'um uu1 Ll1 in DOE-2.1 and from south in TRNSYS 10.1.
In the auxiliary-control section one should note that DOE-2.1 and TRNSYS 10.1 define SERIES and PARALLEL oppositely. In CBS CLSH-CNTRL-1, the text reads: "If MODE is set to SERIES, auxiliary energy is added to boost the delivery temperature of the fluid. If .the storage temperature is lower than the coil return temperature, the hourly load is met entirely by auxiliary. If MODE is set to PARALLEL, the load for the hour will be met 1) totally by solar energy if the solar storage temperature is high enough to completely meet the load, or 2) totally by auxiliary energy if the solar storage temperature is not high enough to completely meet the load" (Building Energy Analysis Group 1980, p. V.160). In TRNSYS 10.1 Type 12, the text reads: "Mode 1: Parallel Auxiliary (O node). Auxiliary makes up only ·that part of the load which cannot be extracted from the flow stream of capacitance rate mcCp and temperature Ti. Mode 2: Series Auxiliary (0 node). Auxiliary supplies the entire load via the bypass circuit when the flow stream of flow rate rnc. and specific heat Cp cannot meet the load" (Klein 1979, p. 4.12-3,4). The users of both these programs should read these descriptions very closely to be absolutely certain they have chosen the appropriate system. The comparison of DOE-2.1 and TRNSYS 10.1 performed at SERI used SERIES and PARALLEL, respectively (see Table 6-1).
22
S:~1,fl, _________________________ T_R_-_8_2_2
SECTION 7.0
COMPARISON OF DOE-2.1-CBS AND TRNSYS 10.1 SIMULATIONS
The quantitative comparison of the two programs is covered in this section. Each figure represents numerous computer runs with each code. The results are plotted and the individual points connected .to obtain the curves. Most of the research focuses on the parametric runs where the collector area is varied as discussed in Sec. 5.0. Less emphasis is placed on the flow rate variation runs even though they were performed for all sites.· The TRY-TMY comparison is included to illustrate previous conclusions from other SERI research and was restricted to only one location.
Figure 7-1 presents DOE-2.1 and. TRNSYS 10.1 monthly insolation for Madison for a collector of 380_m2• On an annual basis, insolation calculated by DOE-2.1 is O. 3% more than that calculated by TRNSYS 10.1 for Madison, O. 5% more for Omaha, 1.1% more for Bismarck, and O. 9% less for Dodge City. While the DOE-2.1 and TRNSYS 10.1 insolation values for the winter-months are very close (less so for Dodge City), the difference increases for the summer months with DOE-2.1 insolation values consistently higher than TRNSYS 10.1 values during those months. Curves for Dodge City, Omaha, and Bismarck are in the Appendix, Fig. A-1.
Figure 7-2 presents DOE-2.1 and TRNSYS 10.1 monthly heating loads for Madison. Q!1 an annual basis, the load calculated by DOE-2.1 is O. 5% less than that calculated by TRNSYS 10.1 for Madison, 0.3% less for Dodge City and Bismarck, and 0.1% less for Omaha. Therefore, the DOE-2.1 and TRNSYS ·10.1 monthly heating loads for all four cities are practically identical.
Annual average collector efficiency and annual average part solar* computed by DOE-2.1 and TRNSYS 10.1 for seven collector areas for Madison are presented in Figs. 7-3 through 7-6. Figure 7-3 is for a single-glaze2 collector with nonselective surface with FRTa = 0.780, FRUL = 20.44 kJ/h-m -°C; Fig. 7-4 is for a single-glazed collector with selective surface, FRTa = 0.705, FRUL = 18.13; Fig. 7-5 is for a double-glazed collector with nonselective surface, FRTa = 0.643, FRUL = 17.99; and Fig. 7-6 is for a single-glazed collector with FRTa = 0.780, FRUL = 26.98. Except for the collector in Fig. 7-6, which was simulated only for Madison, s_imilar curves for Dodge City, Omaha, and Bismarck are in the Appendix, Figs. A-2 through A-4.
The percentages used in the remainder of this section are absolute in that a value is obtained by subtracting one program's results from the other. For example, if one program shows a 50% result and the other a 40% result, our reported difference is 10%.
Annual average collector efficiencies for the two programs (annual total collected energy divided by annual total incident energy on the collector plane) are almost indistinguishable on the graphs for all cases. The differences are
*Average part solar is the terminology used by DOE-2.1 to describe a result similar to. average sol_ar fraction.
23
INSOLATI~ ,: GJ ) 275
DOE-?..1
225
TRNSYS
175
N ~
158
MONTHLY INSOLATION Mj~DISON 1-2.5 / AREA. = 380 SQUARE METERS
188
I
75
8 1 2 3 4 5 6 7 . :~ 9 18 11 IOOH
Figure 7-1. Total MonU'lly lnsolatlon Calculated by DOE-2.1 and TRNSYS 10.1 for Madison·
12 13
UI Ill N ---1 I
-
N V,
DDE-2.1
ratEfS
\
LOAD C GJ)
\
MONTHLY LOAD MADISON \
20 \
10
0
e 1 2 3 4 5 6 7 8 9 10 11 12
MONTH . . - ---~~.
Figure 7-2. Total Monthly Heating Load Calculated by DOE-2.1 and TRNSYS 10.1 for Bulldlng . in Madison
13
UI Ill N --- .
I I
-
H
' 00 N N
PERCENT um
· DOE-2.1 AVE PART SOL '
-·--·-BB
TRNSYS AVE PART SOL
-------
DOE-2.1 AVE COL EFF ~ADIS!JN
N C • 780 21. « :, Cf' 40
TRNSYS AVE COL EFF
·- - 28
0
0 ]00 • COLLECT~ AREA C s;i M >
Figure 7-3. Annual Average Part Solar and Annual Average Collector Efficiency Calculated by DOE-2.1 and TRNSYS 10.1 for Madison with FR = D.780, FRUL = 20.44 kJ/h-m2-°C
71)
UI Ill N ---~
I II -~
i-'I :.p 00 N N
PERCENT 1'1
OOE-2.1 A'if. PART SOL
-·-·-
TRt6YS A1if. PART . SOL
------·
DOE-2.1 AVE COL EFF MADISON
N
" 41 . C. 'TE· 18.13 )
TRNSYS ~VE COL EFF
- -
" " •
COUECTCR AREA C SQ M ) Figure. 7-4. Annual Average Part Solar and Annual Average Collector Efficiency Calculated by
DOE-2.1 and!TRNSYS 10.1 ·1or Madison with FR = 0.705, FRUL = 18.13 kJ/h-1112-° C
711
UI Ill .'41 ---I I
-
1-i
' 00 N N
PERCOO 1'1
IXE-2.1 AVE PART SCl
-·-·-
TRNSYS AVE PART SOL
------IIE-2.1
AVE at EFF MADISON N 00 C .643 17.99 >
TRNSYS AVE COL EFF
. - -
I
I 188 • axJ.ECTii AREA C SQ N >
Figure 7-5. Annual Average Part S~ar andl Annual Average Collector Efficiency Calculated by DOE-2.1 ancl·TRNSYS 110.1 for Madison with FR = 0.643, FAUL= 17.99 kJ/h-m2-° C
711
UI Ill ,_., ---' I -
~ 00 N N
N ·\O
DOE-2.1 .· AVE PART SOL
TRNSYS ~VE PART SOL
DOE-2.1 AVE COL EfF
1R6YS AVE COL EFf
100
80
.e
PERCENT
e.
------.,,,-,----- ---·-. ---- ---· __ .... ---·
.... ---· __ ,,..,.... .---· ,,..,.... .. ~ ----~· ~-~
,,~· /· ,,/
/· ,,/ /' /~
/' /~ MADISON
~- (.780 26.98)
108
COUECTOR AREA C SQ M )
Figure 7-6. Annual ~verage Part Solar and Anraual Average Collector Efficiency Calculated by DOE-2.1 and TRNSYS 10.1 for Madison with FR ta= 0.780, FAUL= 26.98 kJ/h-m2-°C
7BB
UI Ill ,41 ---~
I II -~
~ 00 N N
S:il '*' ________________________ T_R_-_82_2_
most noticeable for Bismarck, the city with the highest heating load, where the greatest difference is O. 5%. Generally, collector efficienci.es calculated by TRNSYS 10.1 are slightly higher than DOE-2.1 values for Madison, Omaha, and Bismarck and slightly lower for Dodge City.
Annual average part solar (annual total solar heating divided by annual total heating load) computed by DOE-2.1 is consistently 1%-3% less than that computed by TRNSYS 10.1. The differences are greater than this range at the smallest collector area for Dodge City, the city with the lowest heating load, and smaller at the larger collector areas when the average part solar approaches 100%.
Overall agreement is very good between DOE-2.1 andTRNSYS 10.1 calculations of· insolation, load, annual average collector efficiency, and annual average part solar for the system modeled.
F'igures 7-7 through 7-10 compare monthly calculations of the two programs for two winter months, February and December. The figures show average part solar and average collector efficiency in Madison for two collector types: singleglazed, nonselective; and double-glazed, nonselective. The largest difference between these DOE-2.1 and TRNSYS 10.1 calculations is 5.5%. Agreement between DOE-2.1 and TRNSYS 10.1 on a monthly basis for the heating system modeled, while not as close as on an annual basis, is still quite good.
Figure 7-11 shows the variation of average part solar and average collector .efficiency with collector flow for fixed collector area and fixed tank volume for Madison for a single-glazed collector with nonselective surface, FRTa = O. 780, and FRUL = 20.44. However, it was discovered during the' project that neither. TRNSYS 10.1 Type 21 using FRTa and FRUL nor DOE-2.1 Type COL-EC-1 is applicable for this use without simultaneously varying FRTa and FRUL (for TRNSYS 10.1) or the efficiency curve coefficients (for DOE-2.1) with the collector fluid flow per unit collector area. This situation is due to FR being a function of the collector fluid flow per unit of collector area and changing with wide variations in operating conditions (Duffie and Beckman 1974, pp. 147, 168). The overall loss coefficient, UL, is a function of temperature so that when the fluid flow rate decreases and the fluid or plate temperature in~reases, UL changes (Duffie and Beckman 1974, p. 168). This variation information is not generally available from manufacturers' literature~ In DOE-2.1~ Type COL-HWB-4 · (Hotte.1-Whillier-Bliss collector model) accommodates this use over the range of flows for which F', the collector efficiency factor, can be considered essentially constant. The researchers recommend inclusion in the CBS documentation of a comment in the definition of FLOW-HOT. in COL-EC-1 and of FLOW-AIR in COL-EC-AIR-1 to the effect that the value supplied must be consistent with the fluid flow at which the efficiency curve· coefficients were determined.
DOE-2.1 results using TMY (Typical Meteorological Year) and TRY (Test Reference, Year) weather data are shown in Fig •. 7-12. Annual average collector efficiency and annual average part solar for Bismarck are plotted versus collector area for a single-glazed collector with nonselective surface. The average part solar predicted by DOE-2.1 · us.ing TRY is 10%-15% less than that predicted using TMY. TMY weather tapes provide radiation information from which insolation may be calculated directly, whereas TRY tapes provide cloud
30
S:~1,fl, ________________________ T_R_-8_2_2_
cover and cloud type information as the basis for determining insolation. Other SERI researchers have recommended using TMY weather tapes in simulations involving solar ·components for locations for which.they are available (Leboeuf 1980; Anderson and Madison 1980). The comparison done for this one site supports their recommendation.
Run times for the TRNSYS 10.1 runs were about 30 s on the CDC 7600 and 8-9 s for DOE-2.1-CBS. However, the simulation intervals were a quarter.of an hour. for TRNSYS 10.1 and one hour (not an option) for DOE-2.1. When TRNSYS 10.1 was run with a trace option using a one-hour simulation interval, the results were essentially the same as with a quarter-hour interval and the run time was approximately the same as for DOE-2.1-CBS.
31
IXE-2. l .AVE PART sm..
TRt6fS AVE PART S[l
IXE-2. l AVE al. F.FF
TRt6fS AVE COL F.FF
111
. I
PERCENT
I
MADISON FEBRUARY (. 7tll 28. « )
----- --.
'
. 111 . am • • CllLECTtR Nf.A C SQ N )
Figure 7-7. Average Part Solar and Average Collector Efficiency Calculated by DOE-2.1 and TRNSYS 10.1 for February for Madison with FR Ta= O. 780, FR UL = 20.44 kJ/h-m2-° C
UI Ill .'41 ---1 I
-
.,.j I
(X) N N
PERCENT liS
IX(:-2.1 AVE PART SOL
-·-·-88
TRN.SYS AV£. PART SOL
··-----· 68
IX(-2.1 AVE cm. EFF
<.,.;, ,(..,,;•
TRQ'S AVE. cm. EFF
- 2S
8
a·
_.-:"' ------. ----~.:::::--~-~--//· ,,
/ ,· ,, / /. //
/· /,, ./
//./ //
'l' . , MADISON FEBRUARY ,,~·
. ,~· C.643 17.99 > ...
~/
--t'.Y- --~· - -' - -- --
HI • 488
au.£CT(I AREA C SQ M )
Figure 7-8. Average Part SQlar"and Average Collector Efficiency Calc1.4-la_ted by oo·E-2.1 and TRNSYS 10.1 for :February for Madison with FR ta= 0.643, FR UL ~ 17 .99 kJ/h-m2-° C
Ill Ill 141 --I I
-
718
111
IXE-2.1 AVE PART SCI.
-·-·-
TJHiYS AVE PART S1l.
·------
IXE-2.1 AVE al EfF
I.,.)
+"' 48
TRNSYS AVE Ill EFF
. - - ''
28
8
PEl[ENT
8
(. 711 28. 4,4 )
111 • CCIJ.ECT(R AREA C SIi N >
Figure 7-9. Average Part Solar and Average Collector 'Efficiency Calculated by DOE-2.1 and TRNSYS 10.1 for December for Madison.with FR Ta= 0.780,'F~UL = 20~44 kJ/h-m2-°C
----
711
UI Ill N ---1 I
-
/;1 I
00 N N
lit
[XE-2.1 AVE PART Sil
··-·- 88
TRf6fS AVE PART 5a..
-------[XE-2.1
· AVE al EFF l,J V,
1R6fS AVE a( EFF
-· --- 2B
I
PERCENT
I
- -
211 • 418 511 • al!EC11I AREA < SQ N )
Figure 7-1'0. Average Part Solar and Average Collector Efficiency Calc.ulated by DOE-2.1 and TRNSYS 10.1 for December for Madison with Fil ta = 0.643, FR UL = .17 .99 kJ/h.-m2-° C.
711
UI Ill .At -If-I I
-
~ 00 N N
lXE-2.1 AVE PART SOL
TRNSYS AVE PART SOL
lXE-2.1 AVE COL fJF
TRNSYS AVE COL EFF
-, - -
. HI PERCENT .
------------------------------ --- ·--·-·-·-/'~.;.---- /.-·-· .,./''... /.
/ /. ,I ~-
/, /~
I I
I I
MADIS0N AREA=388 SQ M • VOO.IJE=3!. 4 OJ .M
// I
I
- -___::::::.~-==-=----=--=-~==------------
. 2000 - - lN 12880
ClllECTCR FUIV < KG,'tR ) Figure 7-11. Annual Average P•I Solar and Annual Average Colecior Efficiency ·calculated by
OOE-2.1 end TRNSYS 10.1 with ·collector Flow \iai"riecf .
Ill Ill .N· ---1 I
-
~ co
. N N
u) .......
PERCENT HI t
TRY AVE PART sm.·
-·-·· 81
. 1MY A~E PART SOL
------
TRY AVE COL EFF
TMY AVE Ill EFF
. -- - 28
\ 8.
8
-----------------.. ~ --~ .. _,,..., .--,---- ... .. -- .--,----.
_,.,,,,,..... --------· .,,.,,.,. -·
,.. ~----,,/ .,,,,,........ ,/ /.
, /. / .
// ./ / ./
,/ / BISMARCK ./' /. ' .
/.
~ ~--' ----- ( ---..:._ - ' ' ---.::.. - .
TRY-TMY C. 788 28. 44 )
DOE-2. 1
. -------=:::.---=._ ____ ~- e:-·------~------
JIil •· 588 I 6ll
... . Flg1:1re 7-12. Annual Average Part Solar and Annual Average Collector Efficiency Calculated by
001:-2.1 us1r1g iRv anci·TMv··weaiher oaia-1o.-· e·i,niarc-k ·
\
. .,.
UI Ill N ---1 I
-
;J I
00 N N·
S:~1,11, --~-----------~-----...a.,.__ __ T_R_.-8_2_2 •. ~ !::' ~
SECTION 8.0
COMMENTS AND RECOMMENDATIONS
As a result of extensive use of DOE-2.1 during the course of this study, SERI researchers have several comments and recommendations concerning the program and its use.
8. 1 COMMENTS
The comparison of DOE-2.1-CBS and TRNSYS 10.1 simulations has shown that the two programs agree remarkably well in most of the cases in this research study. For a heating application, in varying climates and insolation levels and · using typical collector parameters and subsystem configurations, the annual average collector efficiency and annual average part solar are nearly identical: Both programs react the same to variations in collector area and flow rates.
The authors are impressed with the DOE-2.1 format and overall ease of use. The documentation carefully defines terms and indicates required units for keywords, inputs, and outputs. Forms provided in the documentation for keywords and connections further facilitate use. Values of keywords, which are entered into the program without units, are echoed back with the assumed units, a useful technique for reducing input errors. Inputs and connecttons are in words rather than in numerically coded form. Several varieties of prepared weather tapes are stored in the DOE-2.1 library and are easy to use.
The electricity used by the pumps and· fans is a valuable output capability of DOE-2.1.which enables the user to keep track of parasitic energy uses. With the components used to model the system, the electrical demand of the collector and tank pumps is calculated but not that of the pumps in the distribution system.·
Generally · the CBS components available to model systems are flexible, with enough options to cover a wide range of applications. ·For example, heat exchangers may be parallel-flow, counter-flow, cross~flow, or constanteffectiveness types. A desirable improvement in this respect would be the addition of temperature stratification capability in the solar storage tank. Capability for including optj.mal as well as bang-bang controllers would be useful.
Another suggestion for improvement of the simulation of a total solar energy collector system by DOE-2.1 is for the program to handle the shading of the collectors. When CBS is used through Plant, the full capacity of DOE-2.1 is available. In Loads, the shading calculations for building surfaces could be expanded to include any solar energy collector arrays. The shading of these arrays, either by nearby structures or th.e collectors themselves, could be passed to Plant in the form of a number that quantifies the percentage of sunlight actually reaching the collection surfaces. Then, in CBS, the program would take that percentage and reduce the available insolation
39
...
S5~11tf, ________________________ T_R_-_82_2_
appropriately. The designer could then clearly see the ·effects of shading by surfaces near the collectors or by the spacing of the collectors.
8.2 RECOMMENDATIONS
In several cases. the ·researchers recommend reconsideration of default values in DOE-2.1. First, a more typical value of. the coJlector heat capacitance per unit area, CAP in COL-EC-1, would be 0.5 Btu/ft -°F rather than 1.0 (Simon 1976, p. 459) •. Second, the minimum temperature at which heating fluid is supplied to the coil, COIL-T-MIN in CLSH-CNTRL-1, should be as low as ·'practical; the researchers recommend 105°F as a default instead of 120°F. Third, a realistic value of the collector-tank temperature difference required to turn the collector on, DT-MIN in COL-EC.:.1, would be 3° or 5°F rather than 1°F to control cycling and parasitic losses.
Several changes in· DOE-2.1 documentation are recommended. First, more adequate guidance should be provided for the user in selection of efficiency curve coefficients and incidence angle modifier coefficient. The denominators of° the efficiency curve equations on p. V .174 and the efficiency curve graph on p. V.175 should be consistent (Building Energy Analysis Group 1980) •
Second, the definition of FLOW-HOT in COL-EC~l and of FLOW-AIR in COL-EC-AIR-1 should contain a statement such as that in the definition of AREA, i.e., that the value supplied must be consistent with the flow at which the efficiency curve coefficients were determined~ Because manufacturers' literature is sometimes deficient in specifying the flow at .which efficiency curve measurements were made, it is desirable for the documentation to include a typical or nominal value of flow per unit collector a-rea as guidance or even a default value.
Third, the researchers urge that the DEG-DAY-LOADS-I component be returned to the CBS documentation and that detailed instructions for using CBS as a standalone solar program be provided. Much of the advantage of easy usage of CHS will be lost if all solar runs must be made in conjunction with the entire DOE-2.1 program; use of the program to optimize a solar system will be too expensive. In addition, having learned the format of DOE-2.1, the user would be comfortable with it and not inclined to switch to some other program such as TKNSYS 10.1 to perform further solar energy design optimizations.
SERI researchers recommend use of 'IMY weather tapes, when available, for simulations involving solar components (Leboeuf 1980; Anderson and. Madis9n 1980). The i>OE-2 .1 documentation contains a User's Manual for 1MY tapes in Appendix VIII.8 (Building Energy Analysis Group 1980).
Considering the current ·use of SI units, it is discouraging to see a major new program· for scientific and engineering use that requires input in English unfts. The authors ~uggest development of a parallel input-output format using SI units or modified SI units, as used in TRNSYS 10.1.
40
Sifl 1fl, ______________________ T_R-_8_2_2
SECTION 9.0
CONCLUSIONS
This report compares simulations of a simple solar commercial liquid space heating system using CBS, the solar component.of DOE-2.1, and TRNSYS 10.1. The report describes the overall DOE-2.1 program and how CBS relates to it. Results show excellent agreement· between the two programs on an annual basis. Agreement is good also on a monthly basis. For a heating application to a commercial building, in varying climates and ins~lation levels and using typical collector parameters and subsystem configurations, the annual average
·collector efficiency and annual average part solar are nearly identical. The report describes the overall DOE-2 program and how CBS relates to it. Recommendations are made for several.changes in CBS document"ation. These recommendations include. improvements in collector parameter guidance, definitions in flow rates, and degree-day load calculator.
41
S:~1,11, _______________________ T_R_-8_2_2_
SECTION 10.0
REFERENCES
Anderson, J.; Madison, D. 1980. A Comparative Study of the TRY and TMY Meteorological Data. Systems Simulation and Economic Analysis Conference; San Diego, CA; Jan. 23-25, 1980.
Building Analysis Group. 1979 (July). DOE-2, LBL-8688, 8689, 8678. Berkeley, CA: Energy and Environment Division, Lawrence Berkeley Laboratory.
Building Energy Analysis Group. 1980 (Mar.). DOE-2, Version 2.1. Draft. Berkeley, CA: Energy and Environment Division, Lawrence Be,rkeley Laboratory.
Duffie, J. A.; Beckman, w. A. 1974. · York: John Wiley and Sons.
Solar Energy Thermal Process. New
Eden, A.; Simms, D. 1980 (Jan.), SERI-DOE-2 Solar Simulation Study. Systems Simulation and Economic Analysis Conference; San Diego,. CA; Jan. 23-25, 1980.
Eden, A.; Tinsley, J. A. 1977 (Sept.). Second Interim Technical Report on USAFA Solar Test House. CEEDO-TR-77-34. Civil and Environmental Engineering Development Office, Air Force Systems Command, Tyndall Air
-For.ce Rase, FL.
Klein, S. A.; et al. 1979 (June). TRNSYS, A Transient System Simulation Program. Madison, WI: . Solar Energy Laboratory, University of Wisconsin.
Leboeuf, C. 1980 (Feb.). Standard Assumptions and Methods for Solar Heating and Cooling Systems Analyses. SERI/TR-351-402. Golden~ CO: Solar Energy Research Institute.
Raschke, M. A.; Hunn, B. D.; Diamond, s. C. 1978 (June). A Component-Based Simulator for Solar Systems. U.S. Department of Energy Conference on ·system Simulation and Economic Analysis.for Solar Heating and Cooling; San Diego, CA; pp. 8-10.
Simon, F. F. 1976. "Flat-Plate Solar-Collector Performance Evaluation with a Solar Simulator as a Basis for Collector Selection and Performance Predic-
\ tion." Solar Energy. The International Solar Energy Society, Great Rr.itain: Pergamon Press; Vol. 18 (No. 5): pp. 451-466.
Solar Energy Research Institute. 1980 (Jan.). Analysis Methods for Solar Heating and Cooling Applications, Passive and Active Systems. SERI/SP-35-232R. Golden, CO: SERI.
43
TR-822
5:5~1,fl,-------------------
APPENDIX A
D0E~2.l INPUT CARD IMAGES
/'
45
S:~l 1ti1 -----------~------------T_R_-_8_22
INPUT SOLAR
TITLE LINE-1 * MADISON * TITLE LINE-2 .•SOLAR LIQUID C. R. S.• TITLE LINE-3 • SOL CBS - 10 *
BUILDING-LOCATION LAT• 42 LON• 88 T-Z • b ALT• 860 DAYLIGHT-SAVINGS= NO HOLIDAY• NO ••
RUN-PERIOD
ABORT ERRORS
$ SCHEDULES S
..
...
HEAT-2 HEAT-WEEK HEAT-SCHED GEN-_l
•DAY-SCHfDULF (1,241(&81 •• •WEEK-SCHEDULE (~LL) HEAT-2 · •• •SCHEDULE THRU DEC 31 · HEAT-WEEK ~DAY-SCHEDULE (1,61(0.05).
<9,19)(.9,.9,1.,1.,.e,.q,1.,1.,.9,.9,.6> (20,2'lll.2,.21 (22,24)(.1,.1,.11 ••
GEN-2 GEN-WEEK
· •DAY-SCHEDULE (1,24)(0.051 •• =WEEK-SCHEDULE (MON,FRI) GEN-1
(WEI GEN-2 (HOL I GEN-1
GEN-SCHED INF IL-SCHED ·
•SCHEDOLE THRU DEC 31 GEN-WEEK •• •SCHEDULE THRU M~R 31 (ALLl(l,241(11
THRU OCT 31 (ALLl(l,241(01 THRU DEC 31 (ALLl(l,241(11 ••
11Si
PARAMETER
•SCHEDULf THRU DEC 31 (ALLl(l,241(11
COL-AREA• 7158.0
$ S~LAR COMPONENTl $
WX C~PONENT
TYPE• DOE-WEATH-1 ••
INSOL COMPONENT
TYPE • INSOL-1 TILT • 52 AZIMUTH • 180 ACCEPTANCE• 180 GROUND-REFL • ,.2,.2,.2,.2,.2,.2,.2,.z,.2,.2,.z,.z,
CONNECT CLOUD-TYPE TO WX CLOUD-TYPE CLOUD-AMT TO WX CLOUD-AMT
47
..
S:~I
RAO-HOR-TOT TD WX RAO-H~R-TJT RAO-NORl1-0TR TO W1 RAD-NORM-OtR
DDL CO,.PONl:NT
TYPf • OEG-DAY-LQAOS-1 UA • 1411 T-SCH • HE~T-StHED GfN-11AX. • 236Q' ' GEN-SCH• GEN-SCHED OSA-"'IAX • 0 IJSA-SCH"• INFIL-SCHfD
CONNECT T-A~R TO WX T-AMB
COL COMPONENT
TYPE • C".1L-EC'...l ARF.·A ;. COL-ARFA EFF-COFF • C.78,-1.321 flUIO-TE~P • INLET ANGLE-COFF • o.o FLOW-HOT• COL-AREA TIMES .OOQ4294 OEN-HOT• ~5.0 SP-HT-HOT• .775 FLOW-COLD• COL-AQE~ TIMfS .0098244 DEN-COLD• 62.4 . SP-HT-COLD• l•O CXCH-TYPE • CONSTANT-Ef~ EXCH-UA • • 7 T-!l0Il • 212 DT-!'1IN .., 1•8 T-OUT-Ul( • .?IZ T-INI T • ltU CAP• O.O PUl'1P-KW • 1
CONNECT T-IN TO TNK T-S TOR TO TNK RAD-TILT-DU TO INS!Jl UO-TILT-OIF HI l'f~lll RAO-T IL T-TIJT TO INSOL cos-me T IJ INSIJL T-&11413 TO wx
TNK r.n~P~NFNT
TYPE " TAIIIK-1 VOL• COL-A,EA TIMES 1.96~4 TANK-HT/DIA • 2 s·P-HT-FLO • loO OEN-FLO• bZ.4 LIJ33-COEF • OolOOJ T-INIT • 120 ••
T-UNK T•TANK ~AD-TILT-DIR ~ AD-TIL T .. OIF HO-Tlt T-TOT CO'i-I~C T-4118
CONNECT T-IN-TOP FLOW-IN-TOP f•IN-BOT
Tll . COL TO • COL .TO· AUW
T-OUT FLOW-OUT T-LIQ-OUT
.. : ,• .
48
TR-822
$:ii ;If, -------=----------------------TR_-_8_2~2'.
HOW-IN-BOT T-ENV Q-PLANT
TO AUX FLOW-LIQ-OUT TO CONSTANT 68. TO CONSTANT O. • •
AUX CONPONENT
TYPE• CLSH-CNTRL-1 110DE. • SERIES DEN-FLO• 62.4 SP-HT-FLO • l•O EXCH~TYPE • CCONSTANT-EFF,CO~STANT-EFF,CONSTANT-Eff) EXCH-UA • C.7,.7,.7) COIL-T-MIN • (bB,&8,68) FLOW~ (0rl9o82,0I SP-HT-AIR• .24 ••
CONNECT T-LIQ-IN Q-PHC 0-HC 0-ZliC FLOW-PHC FU'IW-HC FlOW-ZHC T-IN-PHC T.-IN-HC T-IN-ZHC
TO TNK T~TANK TO CONSTANT o. TO DDL Q-LOAD TO CONSTANT O. TIJ CONSTANT O. TO CONSTANT 30716• TO CONSTANT O •. TO CONSTANT O. TO DDL - T-SET TO CONSTANT O. ••
'REPOAYS COMPONENT
l.
TYPE a llEPOR.T-1
VARIABLES • 12 FREQUENCY• DAILY REPORT-SCH• RS1 OUT-5 • C CMEANCIN-5) l OUT-b • C Cl1AXCIN-5) J OUT-7 • C CM[NCIN-51 l OUT-8 • C CSU!'lflN-2) I CSUMCIN-1) J OUT-9 • C CSU!'1CIN-4) I CSU!'lflN-U l OUT-10 ., C CSUl"IIIN-41 I CSU11CIN-31 · J OUT-11 • C l1IN(qqq.,csu11cI~-1, I CSUN(IN-311 l . auT-12 • C CSU11(IN-~) J DIVCDE • (1000000., 1000000., 1000000., 1000000., 1., 1., 1.,
.01, .01, .01, 1., 1.,
C* D A I L
• HEADINGS• • TOTAi. • TOTAL • TOTAL • AVG • "lA.X • 11 IN * AVG • UG * AVG • . AVG • TOTAL
DOUBLE-SPACE• NO TITLE-25 • YES
·REPORT-TITLE•.· Y S ti l AR SY_ 5 TE 11 PERFORMANCE *• ., ,. TOTAL INCIDENT ENERGY C11Illl0N 8TU)*,
COLLECTED FNfRGY CM I LL ION eTu,•,. HEATING LOAD C "Ill ION BTUI•,
· SOLAR HEATING C MILLION BTU)*, STORAGE TEMP ( F 1 •., STORAGE .TE11P (Fl•, STORAGE TEMP CF>*•
COLLECTOR EFF (PERCE NH•, SYSTEl1 EFF. CPERCE
0
NTI•, PART SOLAR C PERC°ENTI •,
SIJLA~ AUILO[NG LOAO RATIO•, SOLAR ElEC LOAD (KWHl*I
49
S5t1,::::>---------------------TR_-8_22
DECIMAL-PLACES= (3,3,3,3,1,1,1,1,1,1,2,1) •• ·CONNECT
IN-1 T!J COL Q-INC IN-2 TO COL 0-COL lN-3 TO AUX 0-LOAD IH-4 TO AUX O-SOL IN-5 TO TNK f-TANI< IN b T'.) COL HH ..
REP COMPONENT
TYPE '" REPORT-2 •• CONNECT
IN-1 TO ,COL Q-INC IN-2 TO COL Q-COL IN-3 TO AUX g:_(OAD IN-4 TO AUX Q-SOL IN-5 TO TNK T-TANK IN-6 ft) . COL ELEC ••
ENO ••
CO,..PUTE SOL AP •• STOP ••
50
TR-822 '·-
S:~l 1'11-----~--------------------
APPENDIX B
TRNSYS 10.1 INPUT. CARD IMAGES
51
/
S:tl 11f1 ---------------~--------T_R_-_B_i2
'
• • • •
TRNSYS--SnLAR SIMULATION COMPARISON TO DOt-2.0A/Z.l
T'HISl
SIMULATION 1.0 ~760.0 0.25
• • l'IADISON, WISCONSIN •
•
CONSTANTS 8 COL" 665 VOL = COL • .Oil FLO• COL• 24.0 LAT • 42.0 TTL • 52.0 SHT • •2•0 INT • • 78 SUJ = 26.qa
UNIT q TYPE q DATA READER (Tl'IYr PARAMETERS . 1 ~ 3 1 -1 qooo o -2 qooo o 3 0.1 o 4 1 (24X,F4.0,26~,F4.0,4~X,F4.01
• UNIT 4 TYPE 16 RAO POC PARAl'IETERS 5 5,0 0.0 LAT 4871 SHT INPUTS 7 q,z q,1 9,19 1.20 o,o o,o o,o O.O O.O O.O O.O 0.2 TIL O.O ..
UNII 1 TYPE 21 LIO COL-STOR SYS PARAMETF.RS 15
• • •
COL FLO' 3.25 FLO 4.19 -1.0 INT SLO 100.0 0.7 VOL 1000.0 2.05 2.0 49.0 INPUTS 5 ~.6 9,3 2,1 2,2 o,o o.o o.o 20.0 o.o 20.0 • UNIT 5 TYPE 14 OAILY LOAD PARAl'IETF.RS 44 o.o o.o
10.0 23750.0 13.0 21250.0 16.0 21250.0
-1q.o 3750.0 Z?.O o.o •
a.o .12.0 14.0 18.0 21.0 21,.0
o.o 23750.0 21250.0 21250.0 3750.0
o.o
UNIT 6 TYPE 14 WEEKLY LOAD PARA11ETERS 8 o.o 1.0. •
120.0
UNIT 7 TYPE 15 OPERATOR PARAl1ETERS l 1 INPUTS ·i 5,1 6,1 o.o o.o • UNIT 2 TYPF 12 DO ~OUSE. PARAl1ETERS 8
1.0 .
1.0 2680.0 20.0 4500~0 4.19 INPUTS 4 1,1. 1,2 9,3 7,1 o,o o,o o,o o,o
a.o 21250.0 12.0 16750~0 14.0 23750.0 18.0 13750.0 21.0 1250.0
120.0
0.7 14000.0 1250.0
53
10.0 21250.0 13.0 16750.0 16.0 23750.0 1q.o 13750.0 zz.o 17!i0.0
o.o
S:~l 1fl1------------------------TR_-_8_22
• UNIT 12 TYPE 28 WEEKLY SUM PARAMETERS 37
0 168 0 10000 -11 -1 COL -it -12 -31 2
1 -21 -4 -14
-31 -31
-4 -12 -4 -13 2 · -4 -14 -13
-4.-1~ -4 -1~ -2 2 -4 -31 -13 2
INPUTS 5 ·4,6 1,3 2.3
LABELS q ~COL OCOL OLOAO EFSYS PS SB.LR • UNIT 16 TYPE 28
7
2,5 1, 1
O'iOL TTAt-11< EFCOL
f>Afl V SUM I A"I: 7 -PARAMETERS 37 24 0 10000 -11 -1 1':nL 1 -21 -31 -4 -12 -4 -13 -4 -14 -4 -15 -4 -ll -~l l -', l '1 -n ~ -4 -l4 -1 ~ z ·-~', -31 -13 INPUTS 5
4,6 1,3 z.3 2,5 1,1 LABELS 9 HCOL OCOL OLOAO OSOL TTANK EfCOL EFSYS PS SBLR • UNIT 13 TY~E 28 MONTHLY SUH PAIUMETER S 37 -1 0 10000
-11 -1 COL -4 -12 -31 INPUTS 5
0
2 1 -21
_,. -14
"•6 1,3 2.3 · 2,5 LABELS q
·HCOL. OCOL OLOAO OSOL EFSYS PS S8LR
•
-31 -31
1, 1
-4 -12 2 -4
THNK fFCOL
UNI! ;,~ TYPE 28 MONTHLY SUM TAPf8 PARAMETERS 37. -1 0 10000
-11 -1 COL· -4 -12 -31 2 INPUTS.5
ll 1 -21
-.4 -14
4,6 1,3 2,3 2,5 LABELS 9 HCOL QCnl QLOAO OSOL EFSYS PS SALR . .. UNIT 14 TYPE t8 ~HECK PARAl'IETERS 13 166 0 10000 0
-31 -31
1,1
-4 -12 2 -4
TTANK HCOL
1 -12 -4 -11 -4 -13 -.4 -H -4 INPUTS " 1,6 1,3 1,4 1,5 iABELS 4 QU DE QENV ~LOAD CHECK .oz 1,-2,-3,-4
• • END
54
-4 -13 -4 -14 -4 -15 -14 -13 2 -4 -31 -13
-4 -1~ -4 -14 -4 -1, -1~ -13 2 -4. -31 -13
-2 2
-2 2
2
2 -4
2 -4
·z -4
. TR-822
S:~l ,fl,-----------~-----------=---
APPENDIX C
DOE-2.1 AND TRNSYS 10.1 DATA <XMPARISONS
55
S5fl (\1 ______________________ TR---:'--8_2_2 ,_!::_.,
INStlATI~ C GJ ) 275
m:-2.1
TRNSYS
175
158
MONTHLY INSOLATION MADISON 125 AREA " 388 SIIJARE lETERS
. HI
75
8 . 1 2 3 4. S 8 9 18 11 12 13
275
m:-2.1
225
TRNSYS
175 MONTHLY INSOLATION DODGE CITY 159
125
188
75
8 2 3 4 s 6 7 . i. 9 · · 18 · 11 12 13 ICMH
; ·Figure C-1. Total Monthly. lnsolatlon Calculated· by DOE-2.1 and TRNSYS ~ 10.1 for a) Madison, b) Dodge .. Clty, e) Omaha, and d) Bismarck
,57 I
S5il 1ti1
TR-822
[X(-2.1
TRNSYS
- -
IXE-2.1
TRNSYS
· I161l.A TIIII C GJ > Z1S
- - - ~ 225
' . 211! ' 175
)!i ' MONTHLY INSOLATION OMAHA Mf.FJ. = 31111 SIIJARE IETERS
" 1.5
111
75
B 2 3 5 8 9 18 11 · 12 13
INSII.A TIIII C GJ > Z1S
-
175
MONTHLY INSOLATION • l!i
125
1BB
7S
B 2 3 4 5 6 7 IOfTH
8 9 18 11 12. 13
Figure C-1 .. Total. Monthly· lnsolation Calculated by DPE-2.1 and TRNSYS . 10.1 for a) Madison, b) Dodge City, c) om·aha, and d) Bismarck (Concluded) ·sa
t
S:fl,-1
00£-2.1 AVE PART SOL
-·-·-
TRNSYS AVE PART SOL
------·
00£-2.1 AVE COL EFF
TRNSYS AVE COL fff
·- -
IIE-2.1 AVE PART Sil
TIHiYS AVE PART 91..
IIE-2.1 AVF. CII. EFF
TIHiYS AVE ID. EFF
100
Bil
48
2il
8
111
118
611
4ll
8
PERCENT
8 PERCENT
lll8
TR-822
MADISON . C • 788 20. 44 )
3llll 7lll COUECT!ll ARFJ. C SQ M >
DODGE CITY C. 78B 20. 40 .
e ~ • • a • • ~ llll.EtTIIUREA C SQ N )
Figure C-2. Annual Average Part Solar and Annual Average Collector Efficiency Calculated by DOE-2.1 and TRNSYS 10.1 with FR Ta= 0.780, FRUL = 20.44 kJ/h-m2-° C for a) Madiso.n, b) Dodge
· City, c) Omaha, and d) Bismarck · 59
TR.:..822 S5tl ,lff-------------~------------
IX(-2.1 AV£. PART S(L
1JffiYS AV£. PART S(L
IXE-2.1 AV£. ID. EFF
1JffiYS AV£. ID. EFF
IXE-2.1 AV£. PART S(L
-·-·-
1JffiYS AVF. PNIT S(L
---.---I
IX(-2.1 AVE Cll. EFF
1JffiYS AV£. ID. EfF
-
PERCOO 1•_ .-----------------.--~-------~-------:--~::::·=--:::;~~:;;;:;-".E5!!1S1111---, --::::-·:::;;.- .
118
Ii
48
28
8
8
PERCOO 1•
. 118
CB
8
---:::-· -:::-· . ,,~· /· ,''/ / .
,'~
,,1· ,,J·
~- . OMAHA C. 711 2B. 44 >
·------ . .
. --- --1• 211 • •
auECTIII IIEJ. C SQ N > •
-------::::.-·--· -;---· . ··~ ---:;:::::.-. -:;:::.; -:.:--, , ~·
--~· ,,~· // .
,"'/ /· . ~,,_y
,~
. ,,f. BISMARCK ~· · C. 711 2.l 4H
• • lll.l.ECTIR AR£A C SQ N >
711
Figure C-2. Annual Average Part Solar and Annual Average Collector Efficiency Calculated by DOE-2~1 and TRNSYS 10.1 with . ·FR-ca = 0.780, FRUL = 20.44 kJ/h-ni2-° C for a) ft1adlson, b) Dodge City, c) Omaha, and d) Bismarck (Concluded) i
60 .
• S:il 1tl1
PERCENT
TR-822
llll
00£-2.1 AVE PART SOL
-·--·-Ill
TRHSYS AVE PART SOL
--------6B
OOE-2.1 AVE COL EFF MADISON
48 ( • 785 18. 13 )
TRNSYS AVE COL EFF
8
8 188 388 • see 788
PERCENT · COU£CTIE M?fJ. C SQ M ) 188 .....-:::~~-
--;:::;-LXE-2.1 -:_::?·
AVE PART SCl ,y·'. /,·
··--·- // Ill . ,,1·
TRNSYS /· AVE PART SCl /
------·
11(-"2.1 AV£ Ill EFF DODGE CITY
11° • 48 C. 785 18. lH
TRNSYS AVE Ill EFF
2.8 ~-
8
e ~ ~ • a ~ • ~ CIUECTCR AREA ( SQ M >
Figure C-3. Annual Average Part Solar and Annual Average Collector Efficiency Calculated by DOE-2.1 and TRNSYS 10.1 with FR-ra= 0.705, FRUi.. = 18.13 kJ/h-m2-° C for a) Madison, b) Dodge:City, c) Omaha, and d) Bismarck ·
61
. S:il 1-1 -~---------=---------'---------=T:..:.:R:__...;.8::...:2=.2 PERCENT
. [II-2. J .AVE PART SOL
TRl6YS AV~ PART SOI.. .
[l(-2. J AVE COL EFF
TRNSYS . AVE C!L EFF
~-2.1 AV£ PART SIL
TRNSYS AVE PAKI la
IXE-2. J · AVE Ill. l:fF
IRNSYS AVf. Ill EFF
JIil
Bil
68
48
e
llll
6ll
4B
21·
'
I
e PERCENT
-.... .
·---
JIil
OMAHA· C • 7B5 1B. J3 )
~ _-:---____ ____ 388 4lll 588 6lll
Clll.ECTII! AR£.A C SQ M >
)
711!
I • B B a 5"B 6lll ~ ' .. .- . • au.ECTII! Alf.A < SQ N >
Figure C-3. Annual Av·erage_ P.:a·rt :Solar and Annual Average Collector Efficiency Cal.cUl$ted by DOE-2.1 and TRNSYS 10.1 with FA 't'CI = 0.705, FAUL =118.13. kJ/h-m2-°C for a) Madison, b) Dodge City, c) Omaha, and d) Bismarck (Concluded)
62 .
S:~l11l1 lll8
00£-2.1 AVE PART SOL
-···--·-
TRNSYS AVE PART SOL
------
DOE-2.1 AVE COL ITT
40
TRNSYS AVE COL ITT
- - 2ll
0
lilil
UOE-2.1 AVE PART SOL
-·-· ee
TRNSYS AVE PART SOL
·-----·
DOE-2.1 . A VE COL EFF
40
TRNSYS . . A VE COL ITT
- - 2ll
B
Figure C-4.·
TR-822
PERCENT
MADISON _. C .643 17.99 >
0 !Ill 388 48il 6llll PERCENT lllLl.f.CTIJ! AR£J. C SIi N >
DODGE CITY (.643. 17.99)
B 1 llB 2118 . 388 . 411! 58B · 681! . COU£CTIR AREA C SQM > .
Annual Average Part Solar and Annual Average Collector Efficiency Calculated by DOE-2.1 and TRNSYS. 10.1 with F!i ta = 0.643, FAUL= 17.99 kJ/h-m2-° C for a) Madison, b) Dodge City, c) Om•tta, and d) Bismarck
63
71!8
S5~l 1lf1
IXE-2.1 AVE PART S(l
-·-·-
TRNSYS AVE PART S(l
·------
!XE:..2.1 AVE Ill EFF
TRNSYS AVE CCI. EFF
' - -
!Xl-2.1 AVE Pl.RT S(l
-·-·-
TRNSYS AVE Pl.RT S(l
·------IXE-2.1 -
AVE Ill EFF
lRNS1S AV£ Ill EFF
PERCENT 188
118
Ii
' 48
2! ..
"
•
Ii
, 41
21
I
I
TR-822
OMAHA _ C .643 17.99 >
'. 211 • 4illJ
au£CTIII AREA C SD N >
------~~--:...__-.:_ __ _ 211 , • • IDJ.B:TII MB < SG II > • ••
Figure .C-4. Annual Average Part Solar and Annual Average Collector · . Efflcl•ncy Calculated .by ooe.:.2.1 and TRNSYS 10.1 with Fii "Ea .
·= 0.643, F~U.L. = 17.99 kJ/h"~2·°C for a) Madison, b) Dodge· .City, c) Omaha, and·.d) Bismarck (Concluded) - ·
64.
711
711
Document Control 1. SERI Report No. Page TR-721~822
, 2. NTIS Accession No.
4. Title and Subtitle
A.Comparison of DOE-2 and TRNSYS Solar Heating System Simulation
7. Author(s) Anthony Eden, Marion Morgan
9. Performing Organization Name and Address
Solar Energy Research Institute 1617 Cole Boulevard Golden, Colorado 80401
12. Sponsoring Organization Name and Address
15. Supplementary Notes
3. Recipient's Accession No.
5. Publication Date December 1980
6.
8. Performing Organization Rapt. No.
10. Project/Task/Work Unit No. 3525.11
11. Contract (C) or Grant (G) No.
(C)
(G)
13. Type of Report & Period Covered
Technical Report 14.
16. Abstract .(Limit: 200 words)This paper dis.cusses the Solar Energy Res.ea.;rch Tns.titute (SERI)_ analysis and comparison of the output of the solar energy.section of DOE-2 called Component Based Simulator (CRS) and TRNSYS. SERI researchers investigated the adequacy and sensitivity of CBS when various active solar energy collectors and system~ were interfac~d with a standard space heating system. The analysis by SERI included both single-and double-glazed collectors with selectively and nonselectively coated absorbing surfaces located in four different environments. Th~ results of the study show the agreement between the two programs t.o be remarkably similar. Graphs are presented to illustrate the minor differences in annual average collector efficiency and annual average part solar as well as the thermal load and insolation levels. In addition, difficulties encountered by the researc~ers when performing this study arid when attempting to model the collector systems with each program's components are discussed and recommendations offered to facilitate the solar simulation process for future CBS users.
17· Document Analysis Absorptivity ; Comparative Evaluations:Ql ; Computer Codes:Tl ; a. Descriptors Computerized Simulation :T . ; Efficiency ; Energy_ Models :T ; Insolation ;
Solar Collectors ; Solar Energy Research Institute; Solar Heating Systems ; Solab Space He_a,tincfi ; Space Heating ; Ileatiug· ; Heating Systems ; National Organizations ;
b. Identifiers/ pen-Enaed Terms Optical Properties ; .Physical Properties ; Simulation ; Solar Heating; Space Heating; US Organizations ; US DOE
DOE-2; Computer Based Simulator (CBS) ; TRNSYS c. UC Categories
59c
1. Availability Statement National Technical Information Service U.S. Department of Commerce 5285 Port Royal Road Springfield, Virginia 22161
Form No. 8200-13 (6-79)
19. No. of PaQeS
76 20. Price
$6.00
fr U.S. GOVERNMENT PRINTING OFFICE: 1980--777-084/434
