1、ASHRAE STANDARDASHRAE ANSI/ASHRAE Standard 17-2008(Supersedes ANSI/ASHRAE Standard 17-1998 RA 2003)Method of TestingCapacity of Thermostatic Refrigerant Expansion ValvesApproved by the ASHRAE Standards Committee on January 19, 2008; by the ASHRAE Board of Directors onJanuary 23, 2008; and by the Ame
2、rican National Standards Institute on January 24, 2008. ASHRAE Standards are scheduled to be updated on a five-year cycle; the date following the standard numberis the year of ASHRAE Board of Directors approval. The latest copies may be purchased from ASHRAE Cus-tomer Service, 1791 Tullie Circle, NE
3、, 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 and Canada). Copyright 2008 ASHRAE ISSN 1041-2336American Society of Heating, Refrigeratingand Air-Conditioning Engineers, Inc.1791 Tullie Circle N
4、E, Atlanta, GA 30329www.ashrae.orgSPECIAL NOTEThis American National Standard (ANS) is a national voluntary consensus standard developed under the auspices of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). Consensus is defined by the American National Standar
5、ds Institute (ANSI), of which ASHRAE is a member and which has approved this standard as an ANS, as “substantial agreement reached by directly and materially affected interest categories. This signifies the concurrence of more than a simple majority, but not necessarily unanimity. Consensus requires
6、 that all views and objections be considered, 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 intern
7、ational members, associated societies, and public review.ASHRAE Standards are prepared by a Project Committee appointed specifically for the purpose of writing the Standard. The Project Committee Chair and Vice-Chair must be members of ASHRAE; while other committee members may or may not be ASHRAE m
8、embers, all must be technically qualified in the subject area of the Standard. Every effort is made to balance the concerned interests on 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
9、 review of the Standard,c. offering constructive 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 t
10、esting for rating purposes, by suggesting safe practices in designing and installing equipment, by providing proper definitions of this equipment, and by providing other information that may serve to guide the industry. The creation of ASHRAE Standards and Guidelines is determined by the need for th
11、em, 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.DISCLAIMERASHRAE uses its best efforts to promulgate Standards
12、 and Guidelines for the benefit of the public in light of available information and accepted 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 Standard
13、s or Guidelines or that any tests conducted under its Standards or Guidelines will be nonhazardous or free from risk.ASHRAE Standard Project Committee 17-1998Cognizant TC: 8.8, Refrigerant System Controls and AccessoriesStandards Project Committee Liaison: Thomas E. WatsonRichard J. Buck,* ChairDawo
14、od A. Ali,* Vice ChairPeter G. Malone,* SecretaryLarry D. CummingsEugene A. Dianetti*Albert A. Domingorena*David C. DorsteSung L. Kwon*Frank LatudaDennis A. Littwin*Lawrence J. Loman*Ernest W. Schumacher*Elmer J. Subera*Nicholas G. Zupp* Denotes members of voting status when the document was previou
15、sly approved for publicationASHRAE STANDARDS COMMITTEE 20072008Stephen D. Kennedy, ChairHugh F. Crowther, Vice-ChairRobert G. BakerMichael F. BedaDonald L. BrandtSteven T. BushbyPaul W. CabotKenneth W. CooperSamuel D. Cummings, Jr.K. William DeanRobert G. DoerrRoger L. HedrickEli P. Howard, IIIFrank
16、 E. JakobNadar R. JayaramanByron W. JonesJay A. KohlerJames D. LutzCarol E. MarriottR. Michael MartinMerle F. McBrideFrank MeyersH. Michael NewmanLawrence J. SchoenBodh R. SubherwalJerry W. White, Jr.Bjarne W. Olesen, BOD ExOLynn G. Bellenger, COClaire B. Ramspeck, Assistant Director of Technology f
17、or Standards and Special ProjectsSTANDARDS REAFFIRMATION SUBCOMMITTEE 20072008*James Lutz, ChairMichael BedaSteven BushbyR. Michael MartinBodh SubherwalJames Woods* For the 2008 revision in which minor changes were performed(i.e., updating references), SRS acted as the consensus project committee.CO
18、NTENTSANSI/ASHRAE Standard 17-2008,Method of Testing Capacity of Thermostatic Refrigerant Expansion ValvesSECTION PAGEForeword. 21 Purpose 2 2 Scope . 23 Definitions. 24 Conditions for Testing Capacity 35 Data Required for Reporting Capacity 36 Test Instruments. 37 Test Apparatus . 48 Test Procedure
19、. 49 Capacity Calculation. 510 References . 5Informative Appendix A. 6NOTEWhen addenda, interpretations, or errata to this standard have been approved, they can be downloaded free of charge from the ASHRAE Web site at http:/www.ashrae.org. Copyright 2008 American Society of Heating,Refrigerating and
20、 Air-Conditioning Engineers, Inc.1791 Tullie Circle NEAtlanta, GA 30329www.ashrae.orgAll rights reserved.2 ANSI/ASHRAE Standard 17-2008(This foreword is not part of this standard. It is merely informative and does not contain requirements necessary for conformance to the standard. It has not been pr
21、ocessed according to the ANSI requirements for a standard and may contain material that has not been subject to public review or a consensus process. Unresolved objectors on informative material are not offered the right to appeal at ASHRAE or ANSI.)FOREWORDThis is a revision of ANSI/ASHRAE Standard
22、 17-1998 (RA 2003).This standard was prepared under the auspices of the Amer-ican Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). It may be used in whole or in part, by an association or government agency with due credit to ASHRAE. Adherence is strictly on a voluntary basi
23、s and merely in the inter-ests of obtaining uniform standards throughout the industry.This standard prescribes a method of testing capacity of thermostatic expansion valves for use in air-conditioning and refrigeration systems. This standard does not specify the test conditions to be used for obtain
24、ing the standard rating. That is done in a rating standard developed by the Air-Conditioning and Refrigeration Institute (ARI). The latest edition of ARI Standard 750 is referenced for the test conditions to be used in obtaining standard ratings for thermostatic refrigerant expanding valves.The chan
25、ges made for the 2008 revision are as follows: references were numberedreferences were updated1. PURPOSEThis standard prescribes a method of testing the capacity of thermostatic refrigerant expansion valves for use in vapor-compression refrigeration systems.2. SCOPE2.1 This standard is applicable to
26、 a. thermostatic expansion valves (also referred to in this standard as expansion valves) as defined in Section 3, “Definitions,”b. expansion valves of the direct-acting type but not the pilot-operated type, andc. many currently used refrigerants deemed available and suitable according to ANSI/ASHRA
27、E Standard 151and ANSI/ASHRAE Standard 34.22.2 This standard specifies procedures, apparatus, and instrumentation that will produce accurate capacity data.2.3 This standard does nota. specify tests for production, specification compliance, or field testing of expansion valves, norb. specify capacity
28、 rating conditions for testing expansion valves. These may be found in ARI Standard 750.33. DEFINITIONSThe following definitions apply only to parts and terms used in this standard.capacity of an expansion valve: the refrigerating effect in kW (Btu/h or tons) of refrigeration, produced by the mass f
29、low of refrigerant that will pass through the valve under the condi-tions that are cited in Section 5.certified standard instrument: an instrument calibrated by the manufacturer or other reliable agency and certified as trace-able to the National Institute of Standards and Technology (NIST).direct-a
30、cting valve: an expansion valve designed so that the valve plug opens the valve port in inverse response to sensed equalizer pressure and in direct response to temperature-sensing element temperature. The valve plug is positioned through direct mechanical linkage to the actuating element (e.g., diap
31、hragm or bellows).evaporator: an evaporatively cooled heat exchanger.external equalizer: in a thermostatic expansion valve, a connection from a selected point in the low-pressure part of the circuit to the system pressure-sensing side of the actuating element such that the selected point pressure is
32、 transmitted to the actuating element (e.g., diaphragm or bellows).initial valve opening: a minimal valve opening position not to exceed 0.05 mm (0.002 in.). internal equalizer: in a thermostatic expansion valve, an inte-gral internal port or passage whereby the system pressure-sensing side of the a
33、ctuating element (e.g., diaphragm or bellows) is exposed to valve outlet pressure.liquid refrigerant flowmeter: a device for determining the refrigerant mass flow rate.nominal capacity: the capacity reported by the manufacturer for an expansion valve, citing ANSI/ARI Standard 7503for the test condit
34、ions.operating superheat: the difference between the temperature at the temperature-sensing element and the system refrigerant vapor saturation temperature corresponding to the valve equalizer pressure.permanent bleed rate: the capacity of the permanent bleed provision under the conditions cited in
35、Section 5, expressed either as a percentage of the nominal capacity or in kW (Btu/hor tons) of refrigerating effect produced by the evaporation of that amount of refrigerant flow.permanent bleed-type valve: a valve that has a fixed flow passage incapable of being closed by action of the valve. Such
36、a fixed orifice permits a flow through or in parallel with the main valve port.pilot-operated valve: expansion valve of a type used on large capacity systems (e.g., direct-expansion chillers) where the required capacity per valve is beyond the range of direct-acting valves; this type of valve is und
37、er the control of a direct-acting valve.ANSI/ASHRAE Standard 17-2008 3refrigerant: the working fluid in a refrigerating system that absorbs heat by evaporating at a low temperature and pressure and rejects heat on condensing at a higher temperature and pressure.shall/shall not: indicate that the pro
38、vision is mandatory if compliance with the standard is claimed.should/is recommended: indicate that the provision is not mandatory but is desirable as good practice.static superheat: the superheat required to position the valve at the initial valve opening.superheat change: the difference between th
39、e static superheat and the operating superheat.temperature-sensing element: the part of the expansion valve that senses the temperature at the superheat control point, normally located at the outlet of the evaporator. This element may be remote or integral to the expansion valve body.test valve: the
40、 thermostatic expansion valve being tested for capacity in accordance with this standard.thermostatic expansion valve: a device for controlling super-heat by regulating the mass flow of refrigerant to a refrigera-tion load, actuated by changes in equalizer pressure and temperature-sensing element te
41、mperature.valve plug: a movable part that provides a variable restriction in a port.4. CONDITIONS FOR TESTING CAPACITY4.1 Testing for capacity of thermostatic expansion valves shall be performed in accordance with Section 8 of this stan-dard.4.2 The liquid refrigerant entering the thermostatic expan
42、-sion valve shall be subcooled at least 5C (10F).4.3 The refrigerant should be free from contamination. Refer to ARI Standard 7004for recommendations.4.4 The lubricant concentration in the refrigerant shall not exceed 2% by mass.4.5 If it is desired to use standard test condition values, these may b
43、e found in the related industry standard, ARI Standard 750.35. DATA REQUIRED FOR REPORTING CAPACITY5.1 The predetermined test conditions shall include the following values:a. Refrigerant designation according to ANSI/ASHRAE Standard 34.2b. Temperature of liquid refrigerant entering the expansion val
44、ve.c. Pressures at the expansion valve inlet and outlet.d. External equalizer pressure (if applicable).e. Temperature at the temperature-sensing element.f. Static superheat.g. Superheat change.5.2 The refrigerant mass flow rate shall be the measured value.6. TEST INSTRUMENTS6.1 Measurement equipment
45、 shall be certified standard instruments of the types listed in this section.6.2 Temperature-Measuring Instruments6.2.1 Temperature shall be measured with any device meeting the requirements of ANSI/ASHRAE Standard 41.1.56.2.2 Accuracy of temperature-measuring instruments shall be within 0.15C (0.25
46、F).6.3 Pressure-Measuring Instruments6.3.1 Pressure shall be measured with any device meeting the requirements of ANSI/ASHRAE Standard 41.3.66.3.2 Accuracy of pressure-measuring instruments shall be within 0.5% of the pressure reading.6.4 Refrigerant Flow-Measuring Instruments. Accuracy of flow-meas
47、uring instruments shall be within 1.0% of the indicated value.Figure 1 Air fixture for remote temperature-sensing element valves.Figure 2 Air fixture for integral temperature-sensing element valves.4 ANSI/ASHRAE Standard 17-20086.5 Other Instruments. Dial or other indicators to measure valve plug po
48、sition relative to the valve port shall have a scale graduated in 0.03 mm (0.001 in.) or finer increments.7. TEST APPARATUS7.1 Air Fixture. The static superheat setting of the thermo-static expansion valve shall be measured with the test valve installed in an air fixture as described in Figure 1 or
49、2. The fix-ture shall contain all of the essential elements shown, and instrumentation shall conform to the requirements of Section 6.7.2 Refrigerant Fixture. The capacity of the thermostatic expansion valve shall be measured with the test valve installed in a refrigerant fixture as described in Figure 3 or 4. The system shall contain all of the essential elements shown, and instru-mentation shall conform to the requirements of Section 6.8. TEST PROCEDURE8.1 Static Superheat and Initial Valve Opening8.1.1 Place the thermostatic expansion valve in the appro-priate air fixture
