ASHRAE 24-2013 Methods of Testing for Rating Liquid Coolers.pdf

1、ANSI/ASHRAE Standard 24-2013(Supersedes ANSI/ASHRAE Standard 24-2009)Methods of Testing forRating Liquid CoolersApproved by the ASHRAE Standards Committee on January 26, 2013; by the ASHRAE Board of Directors on January 29, 2013;and by the American National Standards Institute on January 30, 2013.AS

2、HRAE 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 Web site(www.ashrae.org) or from ASHRAE Customer Service, 1791 Tullie Circ

3、le, 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 1041-2336 ASHRAE (www.ashrae.org). For personal use onl

4、y. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAEs prior written permission.SPECIAL NOTEThis American National Standard (ANS) is a national voluntary consensus standard developed under the auspices of ASHRAE.Consensus is defined

5、 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 directly and materially affected interest categories. This signifies the concurrenceof more than a simple majority, but not necessaril

6、y unanimity. Consensus requires that all views and objections be considered, and that aneffort be made toward their resolution.” Compliance with this standard is voluntary until and unless a legal jurisdiction makes compliancemandatory through legislation.ASHRAE obtains consensus through participati

7、on of its national and international members, associated societies, and public review.ASHRAE Standards are prepared by a Project Committee appointed specifically for the purpose of writing the Standard. The ProjectCommittee Chair and Vice-Chair must be members of ASHRAE; while other committee member

8、s 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 ProjectCommittees. The Manager of Standards of ASHRAE should be contacted for:a. interpretation of the contents of this Standard,b.

9、 participation in the next review of the Standard,c. offering constructive criticism for improving the Standard, ord. permission to reprint portions of the Standard.DISCLAIMERASHRAE uses its best efforts to promulgate Standards and Guidelines for the benefit of the public in light of available infor

10、mation 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 conducted under itsStandards or Guideline

11、s 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 designing and installing equipment,

12、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 to this Standard or Guideline and

13、 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 STANDARDS COMMITTEE 20122013Kenneth W. Cooper, Chair Julie M. Ferguson Janice C. PetersonWilliam F. Walter, Vice-Chair Krishnan Gowri Heather L. PlattDoug

14、lass S. Abramson Cecily M. Grzywacz Ira G. PostonKarim 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 Ex

15、OSteven J. Emmerich Rick A. Larson Constantinos A. Balaras, COMark P. ModeraStephanie C. Reiniche, Manager of StandardsASHRAE Standard Project Committee 24Cognizant TC: TC 8.5, Liquid-to-Refrigerant Heat ExchangersShane A. Moeykens, Chair* Arthur Fovargue*Joseph B. Huber, Secretary* Michele Friedric

16、h*Shan S. Li* Neelkanth S. Gupte*Robert R. Bittle* Kaushik Oza*Steven J. Eckels*Denotes members of voting status when the document was approved for publication ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is no

17、t permitted without ASHRAEs prior written permission.CONTENTSANSI/ASHRAE Standard 24-2013, Methods of Testing for Rating Liquid CoolersSECTION PAGEForeword. 21 Purpose 22 Scope . 23 Definitions. 24 Classifications. 25 Expression of Test Results . 26 Test Methods 27 Instruments, Test Apparatus, and P

18、hysical Properties . 48 Test Procedure . 49 References . 5 NOTEApproved addenda, errata, or interpretations for this standard can be downloaded free of charge from the ASHRAE Web site at www.ashrae.org/technology. 2013 ASHRAE1791 Tullie Circle NE Atlanta, GA 30329 www.ashrae.org All rights reserved.

19、ASHRAE is a registered trademark of the American Society of Heating, Refrigerating and Air-Conditioning 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 i

20、n either print or digital form is not permitted without ASHRAEs prior written permission.2 ANSI/ASHRAE Standard 24-2013(This foreword is not a part of this standard. It ismerely informative and does not contain requirementsnecessary for conformance to the standard. It has notbeen processed according

21、 to the ANSI requirementsfor a standard and may contain material that has notbeen subject to public review or a consensus process.) FOREWORDThis is a revision of ANSI/ASHRAE Standard 24-2009.This standard was prepared under the auspices of ASHRAE.It may be used, in whole or in part, by an associatio

22、n or gov-ernment agency with due credit to ASHRAE. Adherence isstrictly on a voluntary basis and merely in the interests ofobtaining uniform standards throughout the industry. The following changes were made for the 2013 revision: References were updated.Minor editorial changes were made.1. PURPOSET

23、his standard prescribes methods of testing for ratingliquid coolers.2. SCOPETo attain this objective, this standarda. classifies liquid coolers as to type,b. lists and defines the terms suggested for rating liquidcoolers, andc. establishes methods of test that shall be used as a basisfor obtaining r

24、atings of liquid coolers.3. DEFINITIONSliquid cooler: a factory-made assembly of elements in whichthe heat is transferred from the liquid to the refrigerant, caus-ing the refrigerant to evaporate and the liquid to be cooled.total refrigeration capacity (of the liquid cooler): the productof the mass

25、flow rate of refrigerant and the difference inenthalpy between the leaving and entering refrigerant,expressed in energy units per unit of refrigeration capacity: that portion of the total refrigera-tion capacity of a liquid cooler that produces useful cool-ing.This is the product of the mass flow r

26、ate of liquid, specificheat of the liquid, and the difference between entering andleaving liquid temperatures, expressed in energy units per unitof time. It is represented also by the total refrigeration capacityless the heat leakage rate.temperature of flowing fluids: the mixed mean streamtemperatu

27、re at a station perpendicular to the flow direction.4. CLASSIFICATIONSThe classifications of liquid coolers, as covered by thisstandard, are as follows:a. Closed cooler, refrigerant in tubesb. Closed cooler, refrigerant in shellc. Open shell and tubed. Tube-in-tubee. Open tank and coilf. Baudelot ty

28、pe5. EXPRESSION OF TEST RESULTSTest results shall be expressed in the following terms:a. The net refrigeration capacity, W (Btu/h)b. Temperature of leaving liquid, C (F)c. Liquid mass flow rate, kg/s (lbm/h)d. Description of liquid sufficient to obtain necessaryphysical propertiese. Liquid pressure

29、drop through the cooler, kPa (psi)f. Saturation temperature of refrigerant leaving liquidcooler, C (F)g. Superheat of refrigerant leaving liquid cooler, C (F)h. Temperature of refrigerant entering expansiondevice, C (F)i. Refrigerant designation6. TEST METHODS6.1 Standard Test Methods6.1.1 Tests sha

30、ll consist of a primary test and a simul-taneous confirming test at the conditions specified.6.1.2 The specified conditions shall include the following:a. Temperature of leaving liquid, C (F). Refer toAHRI Standard 4801for temperature adjustment toallow for rating at desired liquid-side fouling fact

31、or.b. Liquid flow rate, kg/s (lbm/h).c. Necessary physical properties of liquid being cooled.d. Either the net refrigeration capacity, W (Btu/h), orthe saturation temperature, C (F), of the refrigerantleaving the liquid cooler.e. Superheat of leaving refrigerant, C (F).f. Temperature of refrigerant

32、entering expansiondevice, C (F).g. Refrigerant designation.6.1.3 The resulting net refrigeration capacity of theconfirming test (Section 6.3) shall be within 3.0% of theprimary test, but the primary test shall govern for ratingpurposes.6.2 Primary Test Method6.2.1 The primary test shall consist of a

33、 measurement ofthe net refrigeration capacity produced in the cooler by deter-mination ofa. Heat removed from the liquid andb. Heat removed from the ambient air through the externalsurfaces of the cooler (heat leakage rate).6.2.2 Obtain the net refrigeration capacity by determiningthe product of the

34、 following variables: mass flow rate of liq-uid, specific heat of the liquid, and difference between enter-ing and leaving liquid temperatures. ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted with

35、out ASHRAEs prior written permission.ANSI/ASHRAE Standard 24-2013 36.2.3 Determine the mass flow rate of liquid by directmass or volume measurement or liquid flowmeter.6.2.4 Determine specific heat of the liquid using the aver-age of the entering and leaving liquid temperatures and phys-ical propert

36、ies of the liquid.6.2.5 Heat removal rate from the ambient air through theexternal surfaces of the cooler is the product of external sur-face area, the mean temperature difference between the coolerand the ambient air, and the calculated overall heat transfercoefficient.Determine the calculated over

37、all heat transfer coefficientfrom the thermal resistance of the insulation and an ambientair film coefficient of 10 W/(m2C) (2 Btu/hft2F) for naturalconvection.6.2.6 Hold the heat removal rate from the ambient air to1.0% or less of the net refrigeration capacity and to the extentthat no visible swea

38、ting of the cooler or insulated coveringoccurs.6.3 Confirming Test MethodThe confirming test shall consist of a secondary measure-ment of the net refrigeration capacity produced in the coolerby using one of the test methods described in eitherSection 6.3.1 or 6.3.2.6.3.1 Refrigerant Calorimeter Meth

39、od. This methoddetermines cooler refrigeration capacity as the product of themass flow rate of refrigerant and the enthalpy differencebetween entering and leaving refrigerant. This is the totalrefrigeration capacity.Determine mass flow rate of the refrigerant using one ofthe following:a. Refrigerant

40、 flow-measuring instrument.b. A water-cooled refrigerant condenser, where the refrig-eration system is arranged so that the mass flow rate ofrefrigerant is the same in the condenser and cooler. Thecondenser shall be insulated, if necessary, so that thecalculated heat leakage rate through the externa

41、l sur-faces does not exceed 3.0% of the heat rejected to thewater. Determine the heat rejected through the externalsurface to the ambient air qLin accordance withEquations 1 and 2.qL= Us As(tc ta)(1)where qL= heat rejected through external surfaces (heat leak-age), W (Btu/h).(2)wherex/k = 0 if insul

42、ation is not usedx = insulation thickness, m (in.)k = thermal conductivity of insulation, W/(mC)(Btuin./hft2F)hs= film coefficient of ambient air, W/(m2C) (Btu/hft2F); for natural convection, usehs =10 W/(m2C)(2 Btu/hft2F)As= exposed external surface through which heat islost, m2(ft2)tc= condensing

43、temperature, C (F)ta= average ambient air temperature, C (F)Determine the mass flow rate of refrigerant by dividingcondenser heat rejection, including leakage losses, by theenthalpy difference between refrigerant entering and leavingthe condenser. Determine the condenser heat rejection bymultiplying

44、 the mass flow rate of water through the condenserby the enthalpy difference between the leaving and enteringwater.Maintain the refrigerant leaving the condenser in theliquid phase as evidenced by use of a liquid-line sight glass ortemperature measurement to indicate a subcooled condition ofa minimu

45、m of 2C (4F).6.3.2 Energy Balance Method. This method determinestotal refrigeration capacity using an energy balance on theentire refrigeration system. Only use this method if the fol-lowing conditions are met:a. The cooler is installed in a closed refrigerant circuitserved by a water-cooled condens

46、er and a hermetic orsemihermetic electric motor compressor, powered by asinusoidal single-phase or three-phase electric powersupply.b. The compressor and condenser are closely matched incapacity to the cooler.c. No compressor cooling means is used, other than freeconvection of ambient air.d. Mass fl

47、ow rate of refrigerant through compressor, con-denser, and cooler shall be the same (no hot gas bypassis used in the circuit). Condenser, refrigerant piping, andcompressor heads shall be insulated, if necessary, so thatcalculated heat leakage loss does not exceed 3.0% of theheat rejected to the wate

48、r flowing through the condenser.Heat leakage loss shall be determined using the equa-tions of Section 6.3.1 except that a film coefficienthc=20 W/(m2C) (4 Btu/hft2F) shall be used for com-pressor heads to include both convection and radiationeffects, rather than hs= 10 W/(m2C) (2 Btu/hft2F).Heat los

49、s area shall be equal to actual total external areaof compressor heads. Total refrigeration capacity qtcshall be calculated as follows:qtc= qc+ qL WM(3)whereqc= condenser capacity, W (Btu/h)qL= algebraic sum of heat leakages from condenser,compressor heads, piping and cooler, W (Btu/h)WM= electric power input to compressor, W (Btu/h)7. INSTRUMENTS, TEST APPARATUS, AND PHYSICAL PROPERTIES7.1 GeneralCalibrate instruments, whose types and accuracies are listedin Section 7.2.1, against standards before an