BS ISO 9459-5-2007 Solar heating Domestic water heating systems System performance characterization by means of whole-system tests and computer simulation《太阳能加热 家用热水系统 依赖于.pdf

1、BRITISH STANDARD BS ISO 9459-5:2007 Solar heating Domestic water heating systems Part 5: System performance characterization by means of whole-system tests and computer simulation ICS 27.160; 97.100.99 BS ISO 9459-5:2007 This British Standard was published under the authority of the Standards Policy

2、 and Strategy Committee on 28 September 2007 BSI 2007 ISBN 978 0 580 60176 7 National foreword This British Standard is the UK implementation of ISO 9459-5:2007. The UK participation in its preparation was entrusted to Technical Committee RHE/25, Solar heating. A list of organizations represented on

3、 this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. Amendments issued

4、 since publication Amd. No. Date Comments Reference number ISO 9459-5:2007(E)INTERNATIONAL STANDARD ISO 9459-5 First edition 2007-05-15 Solar heating Domestic water heating systems Part 5: System performance characterization by means of whole-system tests and computer simulation Chauffage solaire Sy

5、stmes de chauffage de leau sanitaire Partie 5: Caractrisation de la performance des systmes au moyen dessais effectus sur lensemble du systme et par simulation sur ordinateur BS ISO 9459-5:2007ii iii Contents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 2 3 Terms and definiti

6、ons. 2 4 Symbols, units and nomenclature 4 5 Apparatus 5 5.1 Mounting and location of the SDHW system . 5 5.2 Test facility 8 5.3 Instrumentation. 10 5.4 Location of sensors 10 6 Test method. 12 6.1 General. 12 6.2 Test conditions . 12 6.3 Test sequences . 14 6.4 Data acquisition and processing 17 7

7、 Identification of system parameters . 19 7.1 Dynamic fitting algorithm 19 7.2 Options 19 7.3 Constants 19 7.4 Skip time 20 7.5 Parameters 20 8 Performance prediction 20 8.1 Yearly performance prediction and reporting . 20 8.2 Reference conditions . 20 Annex A (normative) Basis of dynamic SDHW syste

8、m testing. 21 Annex B (normative) Validation of the test method . 24 Annex C (normative) Test report 25 Annex D (informative) Hardware and software recommendations . 30 Bibliography . 35 BS ISO 9459-5:2007iv Foreword ISO (the International Organization for Standardization) is a worldwide federation

9、of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. I

10、nternational organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with

11、 the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approva

12、l by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 9459-5 was prepared by Technical Committe

13、e ISO/TC 180, Solar energy, Subcommittee SC 4, Systems Thermal performance, reliability and durability. ISO 9459 consists of the following parts, under the general title Solar heating Domestic water heating systems: Part 1: Performance rating procedure using indoor test methods Part 2: Outdoor test

14、methods for system performance characterization and yearly performance prediction of solar-only systems Part 3: Performance test for solar plus supplementary systems (withdrawn) Part 4: System performance characterization by means of component tests and computer simulation Part 5: System performance

15、 characterization by means of whole-system tests and computer simulation BS ISO 9459-5:2007v Introduction International Standard ISO 9459 has been developed to help facilitate the international comparison of solar domestic water heating systems. Because a generalized performance model which is appli

16、cable to all systems has not yet been developed, it has not been possible to obtain an international consensus for one test method and one standard set of test conditions. It has therefore been decided to promulgate the currently available simple test methods, while work continues to finalize the mo

17、re broadly applicable procedures. The advantage of this approach is that each part can proceed on its own. ISO 9459 is divided into five parts within three broad categories, as described below. Rating test ISO 9459-1:1993, Solar heating Domestic water heating systems Part 1: Performance rating proce

18、dure using indoor test methods, involves testing for periods of 1 day for a standardized set of reference conditions. The results, therefore, allow systems to be compared under identical solar, ambient and load conditions. Black-box correlation procedures ISO 9459-2:1995, Solar heating Domestic wate

19、r heating systems Part 2: Outdoor test methods for system performance characterization and yearly performance prediction of solar-only systems, is applicable to solar-only systems and solar-preheat systems. The performance test for solar-only systems is a black-box procedure which produces a family

20、of input-output characteristics for a system. The test results may be used directly with daily mean values of local solar irradiation, ambient air temperature and cold-water temperature data to predict annual system performance. ISO 9459-3:1997, Solar heating Domestic water heating systems Part 3: P

21、erformance test for solar plus supplementary systems (now withdrawn), applied to solar plus supplementary systems. The performance test was a black-box procedure which produced coefficients in a correlation equation that could be used with daily mean values of local solar irradiation, ambient air te

22、mperature and cold-water temperature data to predict annual system performance. The test was limited to predicting annual performance for one load pattern. Testing and computer simulation ISO/AWI 9459-4, Solar heating Domestic water heating systems Part 4: System performance characterization by mean

23、s of component tests and computer simulation, a procedure for characterizing annual system performance, uses measured component characteristics in the computer simulation program TRNSYS. Procedures for characterizing the performance of system components other than collectors are also presented in th

24、is part of ISO 9459. Procedures for characterizing the performance of collectors are given in other International Standards. This part of ISO 9459 (i.e. ISO 9459-5) presents a procedure for dynamic testing of complete systems to determine system parameters for use in the “Dynamic System Testing Prog

25、ram” (reference 2). This software has been validated on a range of systems; however, it is a proprietary product and cannot be modified by the user. Implementation of the software requires training from a test facility experienced with the application of the product. This model may be used with hour

26、ly values of local solar irradiation, ambient air temperature and cold-water temperature data to predict annual system performance. The procedures defined in ISO 9459-2, ISO 9459-3, ISO 9459-4 and ISO 9459-5 for predicting yearly performance allow the output of a system to be determined for a range

27、of climatic conditions. The results of tests performed in accordance with ISO 9459-1 provide a rating for a standard day. The results of tests performed in accordance with ISO 9459-2 permit performance predictions for a range of system loads and operating conditions, but only for an evening draw-off

28、. BS ISO 9459-5:2007vi The results of tests performed in accordance with ISO 9459-3 permitted annual system predictions for one daily load pattern. The results of tests performed in accordance with ISO 9459-4 or ISO 9459-5 are directly comparable. These procedures permit performance predictions for

29、a range of system loads and operating conditions. System reliability and safety will be dealt with in ISO 11924, Solar heating Domestic water heating systems Test methods for the assessment of protection from extreme temperatures and pressures. Introduction to ISO 9459-5 The expanding market for Sol

30、ar Domestic Hot-water (SDHW) systems demands a standardized test method for SDHW systems, which makes possible accurate long-term performance prediction for arbitrary conditions from a test as short, simple and cheap as possible. Two facts make this goal difficult to reach. a) The SDHW system gain d

31、epends on many different conditions (e.g., irradiance, ambient temperature, draw-off profile and cold-water temperature). Therefore, a sufficient number of parameters are needed to predict the yearly system gain sufficiently accurately for arbitrary conditions. b) The system state, that is, the temp

32、erature profile inside the store, needs a long time to forget initial conditions; a typical time constant may be one day or more. Since several parameters need to be determined, several system states must occur during the test. If a test method did not take into account the system state dependence o

33、n the past, and thus the dynamic behaviour of the system, the minimum testing times would be quite long (up to several months). The objective of the method described in this part of ISO 9459 is to minimize experimental effort by keeping the test duration short and avoiding extensive measurements. To

34、 compensate for the relatively small amount of experimental data, mathematical tools are used to extract as much information as possible from the test data, while being robust enough to avoid being misled by unimportant transient effects. There are no requirements for steady-state conditions in the

35、tests, and, due to the black-box approach, no measurements inside the store or inside the collector loop are required. Experience has shown that the variability of system states encompassed by the test sequence is the most important precondition for the correct determination of all system parameters

36、 with minimum errors and cross correlation between parameters. Only if the system is driven into many different states, is the influence of each parameter of the model shown on the performance of the system. Therefore, the overall design criterion of a draw-off test sequence is that the system shall

37、 be driven into as many different states as possible in a minimum time. Here, system state means a combination of the store temperature distribution and weather conditions. The system states should include all states that may occur in actual operation. For testing purposes, it is much more important

38、 to have a large variability of system states than to perform draw-offs according to normal user behaviour. Accurate parameter identification will be achieved only if the range of system states in actual operation is covered by the range of system states set up during the tests. The method is applic

39、able to in-situ monitoring, but difficulties arise during in-situ testing, as the operator cannot control the operating conditions. Monitoring of normal user behaviour needs to be carried out over a long time to ensure that all relevant system states are covered, i.e. testing times can be much longe

40、r to achieve the same performance prediction accuracy. This part of ISO 9459 may be applicable to a wide range of systems, including systems with relatively large collectors which have to be cooled by large, frequent draw-offs to prevent overheating, and systems with relatively large storage tanks w

41、hich need to be operated with low loads for days, in order to reach the high store and collector temperatures needed for accurate parameter identification. No single draw-off profile can meet these demands for all systems, since the ratio of storage volume and collector aperture area (V S /A C ) may

42、 vary up to a factor of 20 for the systems considered in this this part of ISO 9459. Therefore, the draw-off volumes have been made dependent on V Sand V S /A C . BS ISO 9459-5:2007vii Experience has shown that the system state variability is especially important for the determination of the effecti

43、ve collector area * C , A the effective collector loss coefficient * C u and the store-loss coefficient U S . To discern between optical and thermal collector properties, the store (and thus the collector inlet temperature) must be kept cold for some intervals with substantial irradiance (Test A) an

44、d then be allowed to become hot while irradiance is sufficient to keep the collector loop operational (Test B). To discern between store losses (which happen all the time) and collector losses (which happen only when there is sufficient irradiance), the store must be operated at high temperatures du

45、ring some periods with low irradiance. BS ISO 9459-5:2007 blank1 Solar heating Domestic water heating systems Part 5: System performance characterization by means of whole-system tests and computer simulation 1 Scope This part of ISO 9459 specifies a method for outdoor laboratory testing of solar do

46、mestic hot-water (SDHW) systems. The method may also be applied for in-situ tests, and also for indoor tests by specifying appropriate draw-off profiles and irradiance profiles for indoor measurements. The system performance is characterized by means of whole-system tests using a black-box approach,

47、 i.e. no measurements on the system components or inside the system are necessary. Detailed instructions are given on the measurement procedure, on processing and analysis of the measurement data, and on presentation of the test report. The theoretical model described in reference 1 is used to chara

48、cterize SDHW system performance under transient operation. The identification of the parameters in the theoretical model is carried out by a parameter- identification software program (see Annex A). The program finds the set of parameters that gives the best fit between the theoretical model and the

49、 measured data. A wide range of operating conditions shall be covered to ensure accurate determination of the system parameters. Measured data shall be pre-processed before being used for identification of system parameters. The identified parameters are used for the prediction of the long-term system performance for the climatic and load conditions of the desired location, using the same model as for parameter identifica