ASHRAE 41 10-2013 Standard Methods for Refrigerant Mass Flow Measurement Using Flowmeters.pdf

1、ANSI/ASHRAE Standard 41.10-2013(Supersedes ANSI/ASHRAE Standard 41.10-2008)Standard Methodsfor RefrigerantMass Flow MeasurementUsing FlowmetersApproved by the ASHRAE Standards Committee on June 22, 2013; by the ASHRAE Board of Directors on June 26, 2013; and bythe American National Standards Institu

2、te on June 27, 2013.ASHRAE Standards are scheduled to be updated on a five-year cycle; the date following the standard number is the year ofASHRAE Board of Directors approval. The latest edition of an ASHRAE Standard may be purchased on the ASHRAE website(www.ashrae.org) or from ASHRAE Customer Serv

3、ice, 1791 Tullie Circle, NE, Atlanta, GA 30329-2305. E-mail:ordersashrae.org. 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. 2013 ASHRAE ISSN 1041-2336SPECIAL NOTEThis American

4、 National Standard (ANS) is a national voluntary consensus standard developed under the auspices of ASHRAE.Consensus is defined by the American National Standards Institute (ANSI), of which ASHRAE is a member and which has approved thisstandard as an ANS, as “substantial agreement reached by directl

5、y and materially affected interest categories. This signifies the concurrenceof more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that aneffort be made toward their resolution.” Compliance with this standard is voluntary u

6、ntil and unless a legal jurisdiction makes compliancemandatory through legislation.ASHRAE obtains consensus through participation of its national and international members, associated societies, and public review.ASHRAE Standards are prepared by a Project Committee appointed specifically for the pur

7、pose of writing the Standard. 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 Standard. Every effort is made to balance the concerned interests on all Proj

8、ectCommittees.The Manager of Standards of ASHRAE should be contacted for:a. interpretation of the contents of this Standard,b. participation in the next review of the Standard,c. offering constructive criticism for improving the Standard, ord. permission to reprint portions of the Standard.DISCLAIME

9、RASHRAE uses its best efforts to promulgate Standards and Guidelines for the benefit of the 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, install

10、ed, or operated in accordance with ASHRAEs Standards or Guidelines or that any tests conducted 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

11、 offering a uniform method of testing for ratingpurposes,bysuggestingsafepracticesindesigningandinstallingequipment,byprovidingproperdefinitionsofthisequipment,andbyprovidingother information that may serve to guide the industry.The creation of ASHRAE Standards and Guidelines is determined by the ne

12、ed for them,and conformance to them is completely voluntary.In referring 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.*Denotes members of voting status when the document was

13、 approved for publicationASHRAE Standing Standard Project Committee 41CognizantTC: 1.2, Instruments and MeasurementSPLS Liaison: Douglass S. AbramsonMark Kedzierski, Chair* Patrick E. Collins* John P. Scott*Richard Hall, Vice Chair* James L. Douglas* Michael E. Shows *Shane Angle, 41.10 Subcommittee

14、 Chair* Alexander Leyderman* Frank J. Spevak*B. Terry Beck* John Lloyd Neel Michael WegenkaASHRAE STANDARDS COMMITTEE 20122013Kenneth W. Cooper, Chair Julie M. Ferguson Janice C. PetersonWilliam F. Walter, Vice-Chair Krishnan Gowri Heather L. PlattDouglass S. Abramson Cecily M. Grzywacz Ira G. Posto

15、nKarim Amrane Richard L. Hall Douglas T. ReindlCharles S. Barnaby Rita M. Harrold James R. TaubyHoy R. Bohanon, Jr. Adam W. Hinge James K. VallortSteven F. Bruning Debra H. Kennoy Craig P. WrayDavid R. Conover Jay A. Kohler Charles H. Culp, III, BOD ExOSteven J. Emmerich Rick A. Larson Constantinos

16、A. Balaras, COMark P. ModeraStephanie C. Reiniche, Manager of Standards ASHRAE (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.CONTENTSANSI/ASHRAE Standard 41.10-

17、2013,Standard Methods for Refrigerant Mass Flow Measurement Using FlowmetersSECTION PAGEForeword. 21 Purpose 22 Scope . 23 Definitions. 24 Classifications. 25 Requirements . 36 Instruments. 37 Flowmeter Test Methods 48 Oil Circulation Rate Measurements 89 Uncertainty Calculations. 1010 Test Report.

18、1011 References . 11Informative Annex ABibliography11Informative Annex BMethods for Uncertainty11Informative Annex CAn Uncertainty Analysis Example for a Coriolis Flowmeter12Informative Annex DAn Uncertainty Analysis Example for a Differential Pressure Flowmeter.15NOTEApproved addenda, errata, or in

19、terpretations for this standard can be downloaded free of charge from the ASHRAEWeb site at www.ashrae.org/technology. 2013 ASHRAE1791 Tullie Circle NE Atlanta, GA 30329 www.ashrae.org All rights reserved.ASHRAE is a registered trademark of the American Society of Heating, Refrigerating and Air-Cond

20、itioning Engineers, Inc.ANSI is a registered trademark of the American National Standards Institute. ASHRAE (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.2 ANSI

21、/ASHRAE Standard 41.10-2013(This foreword is not part of this standard. It is merelyinformative and does not contain requirements necessaryfor conformance to the standard. It has not beenprocessed according to the ANSI requirements for astandard and may contain material that has not beensubject to p

22、ublic review or a consensus process.Unresolved objectors on informative material are notoffered the right to appeal at ASHRAE or ANSI.)FOREWORDFirst published in 2003, Standard 41.10 prescribesmethods for refrigerant mass flow-rate measurement usingflowmeters. A companion standard, ASHRAE Standard41

23、.9-2010,A1prescribes methods for refrigerant mass flow-rate measurement using calorimeters.Selecting an appropriate refrigerant mass flowmetercan be a daunting task given the wide variety of operatingprinciples, measurement precision, and costs of commercialproducts. Some meters can be used for eith

24、er liquids orgases, while others can be used only for liquids or only forgases. Considerable pressure losses are inherent in someapproaches, but the pressure losses in some other types ofmeters are very small and often negligible. Useful basicinformation can be found in textbooks that focus on measu

25、re-ment technology. Once a flowmeter has been selected, theuser may need to consult with the meter manufacturerregarding installation specifics, operating, range limits, cali-bration limits, and other similar performance specifics inorder to obtain the expected measurement accuracy.This revision upd

26、ates the 2008 edition of the standard.Revisions have been implemented to bring this standard intocompliance with ASHRAEs mandatory language require-ments. References have been updated, and an InformativeBibliography (Annex A) has been added. Other changes weremade to improve readability.1. PURPOSETh

27、is standard prescribes methods for refrigerant massflow-rate measurement using flowmeters.2. SCOPEThis standard applies where the entire flow stream of therefrigerant both enters and exits the flowmeter as either a“vapor only” or a “liquid only” state.3. DEFINITIONSThe following definitions apply to

28、 the terms used in thisstandard.bubble-point temperature: a liquid-vapor equilibrium pointfor a pure liquid or for a multicomponent mixture of miscible,pure component liquids, in the absence of noncondensables,where the temperature of the mixture at a defined pressure isthe minimum temperature requi

29、red for a vapor bubble to formin the liquid.error: the difference between the true value of the quantitymeasured and the observed value. All errors in experimentaldata are classified as one of two types: systematic (fixed)errors or random (precision) errors. The terms accuracy andprecisionareoftenus

30、edtodistinguishbetweensystematicandrandom errors.A measurement with small systematic errors issaid to be unbiased.A measurement with small random errorsis said to have high precision.A measurement that is unbiasedand precise is said to be accurate.fixed error: same as systematic error.flowmeter: a d

31、evice employing a detecting element that deter-mines the flow rate of a refrigerant in the gaseous or liquidphase within a closed conduit by measuring a response of thedetecting element.lubricant circulation rate: the ratio of the mass of lubricantcirculating through a refrigerant system to the tota

32、l mass ofrefrigerant and lubricant flowing through the system at a spec-ified set of operating conditions.precision error: same as random error.random error: an error that causes readings to take randomvalues on either side of a mean value. The random error isquantifiedbasedonhowwellaninstrumentrepr

33、oducessubse-quent readings for an unchanging input. Calibration does notcorrect random errors.subcooling: at a defined pressure, the difference between agiven liquid temperature and the bubble-point temperature.steady-state test conditions: operation where at least threesuccessive data points obtain

34、ed at each set of specified condi-tions are neither successively increasing nor successivelydecreasing. To ensure conditions are stable, data readingsshall be taken not less than 3 minutes apart and the test shallbe continued until 3 successive readings are within the limitsof tolerances specified i

35、n Section 5.1.systematic error: anerrorthatpersistsbutisnotduetochance.Calibration corrects systematic errors.uncertainty: an estimated value for the error in a measure-ment,whichmaybetheresultofbothsystematicandrandomerror. Because only random errors are treatable by statisticalmethods, and calibra

36、tion only corrects systematic errors,uncertainty computed using this standard results fromrandom errors.unit under test: a compressor, condensing unit, or other appa-ratus for which refrigerant mass flow rates are measured usingthis standard.4. CLASSIFICATIONS4.1 Operating StateGaseous or Liquid4.1.

37、1 Gaseous refrigerant flowmeters are restricted toapplications where the entire flow stream of the refrigerantenters and exits as a vapor only state.4.1.2 Liquid refrigerant flowmeters are restricted to appli-cations where the entire flow stream of the refrigerant entersand exits as a liquid only st

38、ate. ASHRAE (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.ANSI/ASHRAE Standard 41.10-2013 34.2 Flowmeter Operating PrinciplesFlowmeters within the scope of this

39、 standard shall becapable of measuring refrigerant mass flow rates under eithergaseous or liquid operating conditions in accordance with thetest requirements defined in Section 5. Coriolis-type flowme-ters andthermal massflowmeters providedirect measurementof refrigerant mass flow rate. Other flowme

40、ters listed belowmeasure volumetric flow rates and require fluid density todetermine mass flow rates.Flowmeters that are within the scope of this standardinclude,butarenotlimitedto,thetypeslistedbelow,whicharebriefly described in Section 7.5:a. Coriolis-type flowmetersb. Volume-displacement metersc.

41、 Turbine metersd. Orifice meterse. Flow nozzlesf. Venturi tubesg. Variable-area flowmeters (rotameters)h. Thermal mass flowmetersi. Vortex-shedding metersj. Pitot-static tube metersk. Drag-force metersl. Ultrasonic meters5. REQUIREMENTS5.1 Test PlanAtestplanisadocumentorotherformofcommunicationthat

42、specifies the tests to be performed and the requiredmeasurement accuracy for each test. Sources of the test planinclude, but are not limited to, (a) the person or the organiza-tion that authorized the tests to be performed, (b) a method oftest standard, (c) a rating standard, or (d) a regulation or

43、code.5.2 Values to be Determined5.2.1 Refrigerant mass flow rate, kg/s (lb/h).5.2.2 Lubricant circulation rate, percent by mass, ifrequired in Section 5.3.5.3 Test Requirements5.3.1 Refrigerant mass flow measurements shall be madeat the specified test conditions. When taking multiple mea-surements a

44、t the same test condition, the difference in theindividual measurements shall be within the limits specifiedin the test plan.5.3.2 This standard applies to the measurement of liquidor gaseous refrigerant mass flow rates regardless of the accu-racy requirements specified in the test plan. Any selecte

45、drefrigerant flowmeter shall meet (or exceed) the requiredrefrigerant mass flow-rate accuracy over the full range ofoperating conditions specified in the test plan.5.3.3 The uncertainty in each refrigerant mass flow-ratemeasurement shall be estimated using the methods inSection 9 for every run. Alte

46、rnatively, the worst-caseuncertainty for all runs shall be estimated and reported forevery run.5.3.4 Incorporate an auxiliary lubricant separator into thetest setup if required to ensure that the lubricant circulationrate shall not exceed (a) 2% for a liquid flowmeter or (b) 1%for a gaseous flowmete

47、r.5.3.5 Any lubricant removed from the refrigerant by alubricant separator shall be returned to the refrigerant circuitin a manner that does not affect the refrigerant mass flowmeasurement.5.3.5.1 If the lubricant separator is an integral part ofthe unit under test, the lubricant from the separator

48、shall bereturned in the same way as the equipment is applied.5.3.5.2 If an auxiliary lubricant separator is requiredby Section 5.3.4, the lubricant from the auxiliary separatorshall be returned to the refrigerant circuit at a location down-stream of the flowmeter outlet.5.3.6 The source from which r

49、efrigerant thermodynamicproperties are obtained shall be stated in the test report. Theprimary source is NIST Thermodynamic Properties ofRefrigerants and Refrigerant Mixtures Database (REF-PROP).1Refrigerant properties for refrigerants that are notincluded in REFPROP shall be obtained from the refrigerantsupplier.6. INSTRUMENTS6.1 General6.1.1 Instruments and data acquisition systems shall beselected to meet the accuracy limits specified in the para-graphs below.6.1.2 Measurements from the instruments shall be trace-able to primary or secondary standards calibrat