ASHRAE GUIDELINE 22-2012 Instrumentation for Monitoring Central Chilled-Water Plant Efficiency.pdf

1、ASHRAE Guideline 22-2012Supersedes ASHRAE Guideline 22-2008Instrumentationfor MonitoringCentral Chilled-WaterPlant EfficiencyApproved by the ASHRAE Standards Committee on July 20, 2012, and by the ASHRAE Board of Directors on July 26, 2012.ASHRAE Guidelines are scheduled to be updated on a five-year

2、 cycle; the date following the guideline number is the year ofASHRAE Board of Directors approval. The latest edition of an ASHRAE Guideline may be purchased on the ASHRAE Web site(www.ashrae.org) or from ASHRAE Customer Service, 1791 Tullie Circle, NE, Atlanta, GA 30329-2305. E-mail:ordersashrae.org

3、. Fax: 404-321-5478. Telephone: 404-636-8400 (worldwide) or toll free 1-800-527-4723 (for orders in US andCanada). For reprint permission, go to www.ashrae.org/permissions. 2012 ASHRAE ISSN 1049-894XDISCLAIMERASHRAE uses its best efforts to promulgate Standards and Guidelines for the benefit of the

4、public in light of available information andaccepted industry practices. However, ASHRAE does not guarantee, certify, or assure the safety or performance of any products, components,or systems tested, installed, or operated in accordance with ASHRAEs Standards or Guidelines or that any tests conduct

5、ed under itsStandards or Guidelines will be nonhazardous or free from risk.ASHRAE INDUSTRIAL ADVERTISING POLICY ON STANDARDSASHRAE Standards and Guidelines are established to assist industry and the public by offering a uniform method of testing for ratingpurposes, by suggesting safe practices in de

6、signing and installing equipment, by providing proper definitions of this equipment, and by providingother information that may serve to guide the industry. The creation of ASHRAE Standards and Guidelines is determined by the need for them,and conformance to them is completely voluntary.In referring

7、 to this Standard or Guideline and in marking of equipment and in advertising, no claim shall be made, either stated or implied,that the product has been approved by ASHRAE.ASHRAE Guideline Project Committee 22Cognizant TC: TC 9.1, Large Building Air-Conditioning SystemsSPLS Liaison: Robert G. Doerr

8、*Denotes members of voting status when the document was approved for publicationCharles G. Arnold, Chair* James B. Rishel*Thomas E. Cappellin* Michael M. Roberts*Kenneth L. Gillespie, Jr.* Michael. C. A. SchwedlerThomas B. Hartman Daryl K. Showalter*Mark C. Hegberg Ian D. Spanswick*Roy S. Hubbard, J

9、r. Laurance S.Staples, Jr.John L. Kuempel, Jr.* John I. Vucci*ASHRAE STANDARDS COMMITTEE 20112012Carol E. Marriott, Chair Krishnan Gowri Janice C. PetersonKenneth W. Cooper, Vice-Chair Maureen Grasso Douglas T. ReindlDouglass S. Abramson Cecily M. Grzywacz Boggarm S. SettyKarim Amrane Richard L. Hal

10、l James R. TaubyCharles S. Barnaby Rita M. Harrold James K. VallortHoy R. Bohanon, Jr. Adam W. Hinge William F. WalterSteven F. Bruning Debra H. Kennoy Michael W. WoodfordDavid R. Conover Jay A. Kohler Craig P. WraySteven J. Emmerich Eckhard A. Groll, BOD ExOAllan B. Fraser Ross D. Montgomery, COSte

11、phanie C. Reiniche, Manager of StandardsSPECIAL NOTEThis Guideline was developed under the auspices of ASHRAE. ASHRAE Guidelines are developed under a review process, identifyinga guideline for the design, testing, application, or evaluation of a specific product, concept, or practice. As a guidelin

12、e it is not definitive butencompasses areas where there may be a variety of approaches, none of which must be precisely correct. ASHRAE Guidelines are writtento assist professionals in the area of concern and expertise of ASHRAEs Technical Committees and Task Groups.ASHRAE Guidelines are prepared by

13、 project committees appointed specifically for the purpose of writing Guidelines. The projectcommittee chair and vice-chair must be members of ASHRAE; while other committee members may or may not be ASHRAE members, allmust be technically qualified in the subject area of the Guideline.Development of

14、ASHRAE Guidelines follows procedures similar to those for ASHRAE Standards except that (a) committee balance isdesired but not required, (b) an effort is made to achieve consensus but consensus is not required, (c) Guidelines are not appealable, and(d) Guidelines are not submitted to ANSI for approv

15、al.The Manager of Standards of ASHRAE should be contacted for:a. interpretation of the contents of this Guideline,b. participation in the next review of the Guideline,c. offering constructive criticism for improving the Guideline, ord. permission to reprint portions of the Guideline. ASHRAE (www.ash

16、rae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAEs prior written permission.CONTENTSASHRAE Guideline 22-2012Instrumentation for Monitoring Central Chilled-Water Plant EfficiencySECTION PAGEForeword.

17、 21 Purpose 22 Scope . 23 Definitions. 24 Utilization 25 Chilled-Water Plant Types and Instrumentation . 36 Data Gathering and Trending . 77 Calculations 78 References . 8Informative Appendix AExample Instrument Specifications Table 9Informative Appendix BDetermination of kW/ton 11Informative Append

18、ix CUncertainty Impacts on Measurement Requirements 12Informative Appendix DData Gathering and Trending 15Informative Appendix EExample Specification Language. 16Informative Appendix FExample Application. 28Informative Appendix GExamples of Analyzed Data 35Informative Appendix HBibliography. 39NOTEA

19、pproved addenda, errata, or interpretations for this guideline can be downloaded free of charge from the ASHRAE Web site at www.ashrae.org/technology. 2012 ASHRAE1791 Tullie Circle NEAtlanta, GA 30329www.ashrae.orgAll rights reserved. ASHRAE (www.ashrae.org). For personal use only. Additional reprod

20、uction, distribution, or transmission in either print or digital form is not permitted without ASHRAEs prior written permission.2 ASHRAE Guideline 22-2012(This foreword is not part of this guideline. It is merelyinformative and does not contain requirements necessaryfor conformance to the guideline.

21、)FOREWORDGuideline 22 was developed by ASHRAE to provide asource of information on the instrumentation and collection ofdata needed for monitoring the efficiency of an electric-motor-driven central chilled-water plant. A minimum level of instru-mentation quality is established to ensure that the cal

22、culatedresults of chilled-water plant efficiency are reasonable. Sev-eral levels of instrumentation are developed so that the user ofthis guideline can select the level that suits the needs of eachinstallation.The basic purpose served by this guideline is to enablethe user to continuously monitor ch

23、illed-water plant efficiencyin order to aid in the operation and improvement of that par-ticular chilled-water plant, not to establish a level of efficiencyfor all chilled-water plants. Therefore, the effort here is toimprove individual plant efficiencies and not to establish anabsolute efficiency t

24、hat would serve as a minimum standardfor all chilled-water plants.It is recognized that there are different needs for monitor-ing the efficiency of a chilled-water plant. In most cases, theprincipal objective is to maintain and improve the efficiency ofthe chilled-water plant. There are also cases w

25、here greateraccuracy is desired for monitoring chilled-water plant effi-ciency. The instrumentation section allows the user to deter-mine the required accuracy for the application.The user of this guideline should be aware that the qualityof the instrumentation directly affects the results obtained

26、and,therefore, the accuracy of the chilled-water plant efficiency. Asa result, special attention should be given to the selection ofinstrumentation in order to ensure that the expected result isdelivered.Chilled-water plant efficiency is expressed in differentterms. This guideline uses the recognize

27、d term for chilled-water plant efficiency, which is coefficient of performance(COP). While the guideline uses COP, it is understood thatin areas using inch-pound (I-P) units, kW/ton is the commonterm for determining chilled-water plant efficiency.Appendix B of this guideline provides the information

28、 nec-essary to derive chilled-water plant efficiency when usingkW/ton. Also, in Appendix E, an example specification isprovided for designers of chilled-water plants who wish toincorporate the monitoring of COP or kW/ton into specifi-cations for new plants or modifications of existing plants.It shou

29、ld be pointed out that this guideline does not offerany information on the design of a chilled-water plant. It isapplicable to all electric-motor-driven chilled-water plantsregardless of their configuration or types of chillers, coolingtowers, pumps, and other parasitic electric chilled-water plantl

30、oads. This guideline is designed to help plant managers andoperators achieve and maintain a desired level of efficiencyfor their chilled-water plants.This is a revision of ASHRAE Guideline 22-2008. Thisguideline was prepared under the auspices of ASHRAE. It maybe used, in whole or in part, by an ass

31、ociation or governmentagency with due credit to ASHRAE. Adherence is strictly on avoluntary basis and merely in the interests of obtaining uni-form standards throughout the industry.The changes made for the 2012 revision are as follows: Updated referencesMinor editorial changes1. PURPOSEThis guideli

32、ne defines recommended methods formeasuring chilled-water plant thermal load and energy useand for calculating chilled-water plant efficiency.2. SCOPE2.1 This guideline includesa. recommendations for methods and devices used to mea-sure electrical usage, fluid flow, and temperature, andb. procedures

33、 for acquiring the necessary data and calculat-ing system efficiency.2.2 These procedures are for site-specific application. Theydo not discuss the comparison of collected data between dif-ferent sites, nor do they recommend that data obtained beapplied in this manner.2.3 The procedures also do not

34、discussa. any plants except electrically driven chilled-water plants,b. design and operation of central chilled-water plants,except for recommending the instrumentation used todetermine plant efficiency, orc. selection, application, or operation of system compo-nents.3. DEFINITIONSFor the definition

35、s of key terms used in this guideline,refer to ASHRAE Terminology of Heating, Ventilation, AirConditioning, and Refrigeration.14. UTILIZATION4.1 This guideline allows the user to monitor chilled-waterplant efficiency and to make modifications to the setpoints ofthe system such that the overall effic

36、iency of the chilled-waterplant is improved. In order to properly evaluate the efficiencyof the chilled-water plant, it is first necessary to accuratelymeasure the variables that will determine this efficiency.The efficiency of the chilled-water plant, which is definedin this guideline as coefficien

37、t of performance (COP), isdependent upon the energy use of a number of different piecesof equipment, including, but not limited to, the following: chillers,evaporator pumps,condenser pumps, andcooling towers.Each piece of equipment can have a significant impact onchilled-water plant efficiency. ASHR

38、AE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAEs prior written permission.ASHRAE Guideline 22-2012 3This guideline is entirely focused on reporting the oper-ational efficiency of existi

39、ng plants. For information relatingto achieving efficiency during the initial design of a chilled-water plant, refer to recognized standards such as ANSI/ASHRAE/IESNA 90.1, Energy Standard for Buildings ExceptLow-Rise Residential Buildings,2as well as to the ASHRAEHandbooks.3, 4, 5, 6Since the desig

40、n and layout of chilled-water plants varieswidely depending upon their specific applications, this guide-line addresses common chilled-water plant layouts for instru-mentation and collection of data. Applications that includethermal energy storage and heat recovery are more complexand may require a

41、more sophisticated approach than thisguideline provides. If some modification of the data collectionand analysis method were made to include the additionalequipment used in such applications, this variation on themethodology of this guideline could be used to give an overallchilled-water plant effic

42、iency.Chilled-water plant efficiency is not dependent upon anyone device; rather, it is the overall match of system compo-nents that determine efficiency.4.2 Informative Appendix E of this guideline provides asample specification that can be used when management pre-fers to contract the determinatio

43、n of chilled-water plant effi-ciency to an outside vendor or agency. For this guideline to becited in a specification, the following plant-specific informa-tion must be provided:Equipment whose power is to be included.Equipment whose power is not to be included (if any).Thermal cooling loads to be i

44、ncluded.Thermal cooling loads not to be included (if any).The maximum allowable error tolerance in the result.A summary of how the gathered data should be storedand presented.5. CHILLED-WATER PLANT TYPES AND INSTRUMENTATION5.1 Primary/Secondary Chilled Water. Detailed inFigure 5-1 is an example prim

45、ary/secondary chilled-watersystem. The diagram provides a set of typical points thatcould be measured to give an overall chilled-water plant COP.These points can be reduced or expanded upon as the userdeems necessary.5.2 Primary or Variable Primary Flow System. Detailedin Figure 5-2 is an example pr

46、imary flow system. A systemsuch as this normally utilizes variable-frequency drives on thechilled-water pumps, as is specified by some requirements ofANSI/ASHRAE/IESNA Standard 90.1.2The diagram pro-vides a set of typical points that could be measured to give anoverall chilled-water plant COP. These

47、 points can be reducedor expanded upon as the user deems necessary.5.3 Instrumentation. To measure chilled-water plant effi-ciency, appropriate instrumentation is required to achieve theexpected result of this guideline. An instrumentation tablesuch as Table 5-1 should be used to define the instrume

48、ntrange, measurement range, and measurement accuracy foreach piece of equipment that uses electric energy. The specificinstrument and the measurement range are dependent on thecapacity of equipment for the specific chilled-water plant. SeeInformative Appendix A, Instrument Specifications Table, fora

49、n example of the data that should be provided in the table.Depending on the specific application, the user maydecide to measure chilled-water plant efficiency with or with-out the pump energy required to distribute water to the loads. Data calculation and archiving of this data should be toone order of magnitude greater than the measurement accu-racy. Operator interface display resolution should be consis-tent with the measurement accuracy; the recommendation ofthis guideline is that the resolution should be the same magni-tude as the midpoint of the measured valu