1、Page 1 of 1 2006 ASHRAE. All Rights reserved. ERRATA SHEET FOR ANSI/ASHRAE STANDARD 25-2001 (RA 2006) Methods of Testing Forced Convection and Natural Convection Air Coolers for Refrigeration April 20, 2006 The corrections listed in this errata sheet apply to ANSI/ASHRAE Standard 25-2001 (RA 2006).
2、The outside back cover marking identifying the first printing is “86060 PC 2/06”. Page Erratum 2 2 Scope. In the second sentence of Section 2 change “recalculated” to “recirculated” so it now reads: It does not include air coolers of the recirculated primary liquid refrigerant type. ASHRAE STANDARDA
3、merican Society of Heating, Refrigeratingand Air-Conditioning Engineers, Inc.1791 Tullie Circle NE, Atlanta, GA 30329www.ashrae.orgMethods of TestingForced Convection andNatural ConvectionAir Coolers forRefrigerationANSI/ASHRAE Standard 25-2001 (RA 2006)Reaffirmation of ANSI/ASHRAE Standard 25-2001A
4、pproved by the ASHRAE Standards Committee on June 23, 2001, and reaffirmed on January 21, 2006; by theASHRAE Board of Directors on June 28, 2001, and reaffirmed on January 26, 2006; and by the American NationalStandards Institute on December 17, 2001, and reaffirmed on January 27, 2006.ASHRAE Standa
5、rds are scheduled to be updated on a five-year cycle; the date following the standard number isthe year of ASHRAE Board of Directors approval. The latest copies may be purchased from ASHRAE CustomerService, 1791 Tullie Circle, NE, Atlanta, GA 30329-2305. E-mail: ordersashrae.org. Fax: 404-321-5478.
6、Tele-phone: 404-636-8400 (worldwide) or toll free 1-800-527-4723 (for orders in US and Canada). Copyright 2006 ASHRAE, Inc.ISSN 1041-2336When addenda, interpretations, or errata to this standard have been approved, they can be downloaded free ofcharge from the ASHRAE Web site at http:/www.ashrae.org
7、.SPECIAL NOTEThis American National Standard (ANS) is a national voluntary consensus standard developed under the auspices of the AmericanSociety of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). Consensus is defined by the American National StandardsInstitute (ANSI), of which ASHRA
8、E is a member and which has approved this standard as an ANS, as “substantial agreement reachedby directly and materially affected interest categories. This signifies the concurrence of more than a simple majority, but not necessarilyunanimity. Consensus requires that all views and objections be con
9、sidered, and that an effort be made toward their resolution.”Compliance with this standard is voluntary until and unless a legal jurisdiction makes compliance mandatory through legislation.ASHRAE obtains consensus through participation of its national and international members, associated societies,
10、 and publicreview.ASHRAE Standards are prepared by a Project Committee appointed specifically for the purpose of writing the Standard. TheProject Committee Chair and Vice-Chair must be members of ASHRAE; while other committee members may or may not be ASHRAEmembers, all must be technically qualified
11、 in the subject area of the Standard. Every effort is made to balance the concerned interestson all Project Committees. 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 constr
12、uctive criticism for improving the Standard,d. permission to reprint portions of the Standard.ASHRAE INDUSTRIAL ADVERTISING POLICY ON STANDARDSASHRAE Standards and Guidelines are established to assist industry and the public by offering a uniform method of testingfor rating purposes, by suggesting s
13、afe practices in designing and installing equipment, by providing proper definitions of thisequipment, and by providing other information that may serve to guide the industry. The creation of ASHRAE Standards andGuidelines is determined by the need for them, and conformance to them is completely vol
14、untary.In referring to this Standard or Guideline and in marking of equipment and in advertising, no claim shall be made, eitherstated or implied, that the product has been approved by ASHRAE.DISCLAIMERASHRAE uses its best efforts to promulgate Standards and Guidelines for the benefit of the public
15、in light of available informationand accepted industry practices. However, ASHRAE does not guarantee, certify, or assure the safety or performance of anyproducts, components, or systems tested, installed, or operated in accordance with ASHRAEs Standards or Guidelines or thatany tests conducted under
16、 its Standards or Guidelines will be nonhazardous or free from risk.ASHRAE STANDARDS COMMITTEE 2005-2006Richard D. Hermans, ChairDavid E. Knebel, Vice-ChairDonald L. BrandtSteven T. BushbyPaul W. CabotHugh F. CrowtherSamuel D. Cummings, Jr.Robert G. DoerrHakim ElmahdyRoger L. HedrickJohn F. HoganFra
17、nk E. JakobStephen D. KennedyJay A. KohlerJames D. LutzMerle F. McBrideMark P. ModeraCyrus H. NasseriStephen V. SantoroStephen V. SkalkoDavid R. TreeJerry W. White, Jr.James E. WoodsWilliam E. Murphy, BOD ExORonald E. Jarnagin, COClaire B. Ramspeck, Assistant Director of Technology for Standards and
18、 Special ProjectsASHRAE Standing Standard Project Committee 25Cognizant TC: TC 8.4, Air-to-Refrigerant Heat Transfer EquipmentSPLS Liaison: William J. LandmanAlfi Helmy Malek, Chair* Daniel E. Kramer*Roland A. Ares* Michel LeCompte*Raynald C. Clarke* Dean R. Peterson*Lowell D. Hettinger* Gordon B. S
19、truder*Bodh R. Subherwal* Denotes members of voting status when the document was approved for publication.CONTENTSANSI/ASHRAE Standard 25-2001 (RA 2006)Methods of Testing Forced Convection andNatural Convection Air Coolers for RefrigerationSECTION PAGEForeword. 21 Purpose 22 Scope . 23 Definitions.
20、24 Basis of Testing 35 Methods of Testing . 46 Instruments. 47 Apparatus . 68 Test Procedures 99 Data to Be Recorded 1010 Computations 1111 References . 1212 Appendix A . 12NOTEWhen addenda, interpretations, or errata to this standard have been approved, they can be downloaded free of charge from th
21、e ASHRAE Web site at http:/www.ashrae.org. Copyright 2006 American Society of Heating,Refrigerating and Air-Conditioning Engineers, Inc.1791 Tullie Circle NEAtlanta, GA 30329www.ashrae.orgAll rights reserved.2 ANSI/ASHRAE Standard 25-2001 (RA 2006)(This foreword is not part of this standard. It is m
22、erelyinformative and does not contain requirements necessaryfor conformance to the standard. It has not beenprocessed according to ANSI requirements for astandard and may contain material that has not beensubject to public review or a consensus process.)FOREWORDThis is a reaffirmation of ASHRAE Stan
23、dard 25-2001.This standard was prepared under the auspices of the Ameri-can Society of Heating, Refrigerating and Air-ConditioningEngineers (ASHRAE). It may be used, in whole or in part, byan association or government agency with due credit toASHRAE. Adherence is strictly on a voluntary basis andmer
24、ely in the interests of obtaining uniform standardsthroughout the industry.The changes made for the 2006 reaffirmation were: Reaffirmation dates were updated in Section 6.1Code numbers referenced in Section 7.1.1.3 wereupdated“That” was corrected to “than” in Section 7.2.2“Arithmetical” was correcte
25、d to “arithmetic” in Sec-tion 8.3.6The explanation of Appendix A was added just beforethat section1. PURPOSEThis standarda. establishes uniform methods of testing for obtaining per-formance data,b. lists and defines the terms used in testing,c. specifies data to be recorded and formulas to be used i
26、ncalculations, andd. sets limits and tolerances in testing.2. SCOPEThis standard prescribes methods of testing the coolingcapacities and airflow rates of forced convection and naturalconvection air coolers for refrigeration. It does not include aircoolers of the recalculated primary liquid refrigera
27、nt type. Itdoes not include air-conditioning units for which testing meth-ods are given in other standards.3. DEFINITIONS AND SYMBOLS3.1 Definitionsair cooler: a factory-made device to transfer heat from arefrigerated space to a refrigerant through the medium of air.Coolers shall consist of the unit
28、 as delivered and fitted with theaccessories, such as heat exchangers, that are supplied with oras a part of the cooler.dry-type air cooler: an air cooler wherein heat transfer is notimplemented by a liquid spray during the operating period.external static pressure loss: the static pressure loss res
29、ultingfrom airflow through ductwork and other external elementsfitted to the air cooler.forced circulation-type air cooler: an air cooler with themeans to mechanically circulate the air.free delivery-type air cooler: an air cooler designed to take airfrom and discharge it into the cooled space witho
30、ut ductworkor other external elements that impose air resistance.gross total cooling effect: the heat absorbed by the refrigerant.This is the sum of the net total cooling effect and the heatequivalent of the energy required to operate the cooler.internal static pressure loss: the air pressure loss r
31、esultingfrom airflow through the assembled cooler as supplied fromthe factory.latent cooling effect: that portion of the cooling effect thatresults in water vapor condensation in the air circulatingthrough the cooler.natural convection-type air cooler: an air cooler that dependson natural convection
32、 for air total cooling effect: the refrigeration capacity available forspace and product cooling. It is equal to the gross total coolingeffect less the heat equivalent of energy required to operate thecooler.nonvolatile refrigerant: one that remains a liquid during theprocess of absorbing heat with
33、in the air cooler.preliminary run: successive sets of readings compiled duringcontinuous cooler operation with the objective of establishinga steady-state condition.pressure-type air cooler: an air cooler designed for use withexternal elements that impose air resistance.sensible cooling effect: that
34、 portion of the total cooling effect thatresults in changes in dry-bulb temperature of the air and vapormixture circulating through the cooler. It is expressed either as netor gross depending on whether the heat equivalent of the energyrequired to operate the cooler is included or omitted.sensible h
35、eat ratio: the ratio of net sensible cooling effect tothe net total cooling effect.set of readings: a complete series of data, taken as simulta-neously as practicable, that includes all the informationrequired for the determination of cooler performance.spray-type air cooler: an air cooler, with or
36、without coolingsurface, fitted to spray liquid continuously into the airstream.standard conditions: the specific set of conditions listed.standard rating: air cooler performance at specified standardconditions in ARI or other recognized standards. ANSI/ASHRAE Standard 25-2001 (RA 2006) 3test run: su
37、ccessive sets of readings showing that conditionshave been maintained within the required limits, compiledduring cooler operation at a steady-state condition. A test runmust always follow a preliminary run without interruption.Whenever successive readings are not within the requiredlimits, the test
38、run shall be extended until the successive setsof readings are within the required accuracy.total static pressure loss: the sum of the internal and externalstatic pressure losses.volatile refrigerant: one that changes from the liquid to thevapor state in the process of absorbing heat within the airc
39、ooler.3.2 Symbolsc = specific heat of liquids, Btu/lbF (J/kgK)E = total electrical input to fan motor(s) of forcedcirculation air coolers, We = efficiency of motorEc= total electrical input to heaters and auxiliaryequipment of calibrated box during test, WEk= total electrical input to heaters and fa
40、ns (if used) ofcalibrated box during calibration, WH = air enthalpy: for tests requiring humidity control,enthalpy determined from wet-bulb and dry-bulbtemperature readings; for tests not requiringhumidity control, sensible heat determined fromspecific heat of air and temperature of air above anarbi
41、trary datumH1= enthalpy of the refrigerant liquid entering the aircooler, Btu/lb(J/kg)H2= enthalpy of the refrigerant vapor leaving the aircooler, Btu/lb (J/kg)h1= enthalpy of air and water vapor mixture entering theair cooler, Btu/lb (J/kg) dry airh2= enthalpy of air and water vapor mixture leaving
42、 theair cooler, Btu/lb (J/kg) dry airKc= heat leakage coefficient of calibrated box, Btu/h F(W/C)P = test room barometric pressure, in. Hg (kPa)Q1= airflow rate entering the air cooler, cfm (m3/s)Q2= airflow rate at standard conditions, scfm (std. m3/s)qt= total gross cooling capacity, Btu/h (W)qta=
43、 total air-side gross cooling capacity, Btu/h (W)qtr= total refrigerant-side gross cooling capacity, Btu/h(W)qs= sensible gross cooling capacity, Btu/h (W)qsa= sensible air-side gross cooling capacity, Btu/h (W)qL= latent gross cooling capacity, Btu/h (W)qLa= latent air-side gross cooling capacity,
44、Btu/h (W)T1= temperature of refrigerant entering air cooler, F (C)T2= temperature of refrigerant leaving air cooler, F (C)t1= dry-bulb temperature of air entering the air cooler,F (C)t2= dry-bulb temperature of air leaving the air cooler,F (C)t3= average dry-bulb temperature of air within thecalibra
45、ted box, F (C)t4= average dry-bulb temperature of air surrounding thecalibrated box, F (C)trf= temperature rise of the airflow across the fan or fanwith motor, F (C)trr= temperature drop of the refrigerant flow through thecondenser, F (C)trw= temperature rise of the water through the condenser,F (C)
46、V1= specific volume of air and water vapor mixtureentering air cooler, ft3/lb (m3/kg) dry airwnv= mass flow rate of nonvolatile refrigerant, lb/h (kg/s)wo= ratio of oil to refrigerant in the refrigerant flowstream, lb/lb (kg/kg)wv= mass flow rate of volatile refrigerant, lb/h (kg/s)ww= mass flow rat
47、e of water lb/h (kg/s)Note:a. For volatile refrigerant coils, H1is the enthalpy of therefrigerant entering the refrigerant flow control device orheat interchanger, if included.b. For volatile refrigerant coils, T1is the temperature of therefrigerant entering the refrigerant flow control device orhea
48、t interchanger, if included.c. Standard air conditions are 70F (21C), 29.92 in. Hg(101 kPa), 0.075 lb/ft3(1.2 kg/m3).4. BASIS OF TESTING4.1 Frosting of Coil Surfaces4.1.1 This standard provides a simplified method of test-ing for operating conditions where frost would normally formon the coil. For t
49、ests with refrigerant temperatures below 32F(0C), no moisture is added to the test enclosure. The coil isdefrosted in its normal manner, and the test is then run understeady-state conditions. Note: Several defrost cycles may be necessary to attainsteady-state operation prior to running the test.4.1.2 In practice, coils operating below freezing requiredefrosting at intervals that depend upon operating conditions.Heavy frosting conditions will require an application factorapplied to the standard results. Industry now applies such afactor by sele
