AHRI 520-2004 PERFORMANCE RATING OF POSITIVE DISPLACEMENT CONDENSING UNITS.pdf

1、ANSI/AHRI Standard 520 (formerly ARI Standard 520) 2004 Standard for PERFORMANCE RATING OF POSITIVE DISPLACEMENT CONDENSING UNITS Price $10.00 (M) $20.00 (NM) Copyright 2004, by Air-Conditioning, Heating and Refrigeration Institute Printed in U.S.A. Registered United States Patent and Trademark Offi

2、ce IMPORTANT SAFETY RECOMMENDATIONS AHRI does not set safety standards and does not certify or guarantee the safety of any products, components or systems designed, tested, rated, installed or operated in accordance with this standard/guideline. It is strongly recommended that products be designed,

3、constructed, assembled, installed and operated in accordance with nationally recognized safety standards and code requirements appropriate for products covered by this standard/guideline. AHRI uses its best efforts to develop standards/guidelines employing state-of-the-art and accepted industry prac

4、tices. AHRI does not certify or guarantee that any tests conducted under its standards/guidelines will be non-hazardous or free from risk. Note: This standard supersedes ARI Standard 520-97. TABLE OF CONTENTS SECTION PAGE Section 1. Purpose 1 Section 2. Scope .1 Section 3. Definitions .1 Section 4.

5、Test Requirements .2 Section 5. Rating Requirements .2 Section 6. Minimum Data Requirements for Published Ratings 3 Section 7. Operating Requirements 3 Section 8. Marking and Nameplate Data 3 Section 9. Conformance Conditions .3 TABLES Table 1. ARI Standard Rating Conditions for Condensing Units for

6、 Refrigeration Applications .4 APPENDICES Appendix A. References Normative 5 Appendix B. References Informative 5 Appendix C. Method to Handle Zeotropic Mixtures Informative .6 FIGURES Figure C1. Cycle Process for Single Component Refrigerants and Azeotropic Mixtures .6 Figure C2. Cycle Process for

7、Zeotropic Refrigerant Mixtures 7 Figure C3. Definitions of Subcooling and Superheating .8 ANSI/AHRI STANDARD 520-2004 1 PERFORMANCE RATING OF POSITIVE DISPLACEMENT CONDENSING UNITS Section 1. Purpose 1.1 Purpose. The purpose of this standard is to establish, for positive displacement condensing unit

8、s: definitions; test requirements; rating requirements; minimum data requirements for Published Ratings; operating requirements; marking and nameplate data and conformance conditions. 1.1.1 Intent. This standard is intended for the guidance of the industry, including manufacturers, designers, instal

9、lers, contractors and users. 1.1.2 Review and Amendment. This standard is subject to review and amendment as technology advances. Section 2. Scope 2.1 Scope. This standard applies to electric motor driven, single and variable capacity positive displacement condensing units for air-cooled, evaporativ

10、ely-cooled, and water-cooled refrigeration applications. 2.1.1 Refrigerant. The rating points in this standard are based on commonly used refrigerants. 2.2 Exclusions. 2.2.1 This standard does not apply to condensing units intended for use in: a. Household refrigerators and freezers b. Automotive ai

11、r-conditioners c. Dehumidifiers Section 3. Definitions All terms in this document follow the standard industry definitions in the current edition of ASHRAE Terminology of Heating, Ventilation, Air Conditioning and Refrigeration unless otherwise defined in this section. 3.1 Coefficient of Performance

12、 (COP). A ratio of the Cooling/Heating Capacity in watts W to the power input values in watts W at any given set of Rating Conditions expressed in watts/watt W/W. For heating COP, supplementary resistance heat shall be excluded. 3.1.1 Standard Coefficient of Performance. A ratio of the capacity to p

13、ower input value obtained at Standard Rating Conditions. 3.2 Energy Efficiency Ratio, (EER). A ratio of the Cooling Capacity in Btu/h to the power input values in watts at any given set of Rating Conditions expressed in Btu/(Wh). 3.2.1 Standard Energy Efficiency Ratio. A ratio of the capacity to pow

14、er input value obtained at Standard Rating Conditions. 3.3 Positive Displacement Condensing Unit. A specific combination of refrigeration system components for a given refrigerant, consisting of one or more electric motor driven positive displacement compressors, condensers, and accessories as provi

15、ded by the manufacturer. ANSI/AHRI STANDARD 520-2004 2 3.4 Published Rating. A statement of the assigned values of those performance characteristics, under stated rating conditions, by which a unit may be chosen to fit its application. These values apply to all units of like nominal size and type (i

16、dentification) produced by the same manufacturer. The term Published Rating includes the rating of all performance characteristics shown on the unit or published in specifications, advertising or other literature controlled by the manufacturer, at stated Rating Conditions. 3.4.1 Application Rating.

17、A rating based on tests performed at application Rating Conditions, (other than Standard Rating Conditions). 3.4.2 Standard Rating. A rating based on tests performed at Standard Rating Conditions. 3.5 Rating Conditions. Any set of operating conditions under which a single level of performance result

18、s and which causes only that level of performance to occur. 3.5.1 Standard Ratings Conditions. Rating conditions used as the basis of comparison for performance characteristics. 3.6 Refrigerating Capacity. The capacity associated with the increase in total enthalpy between the liquid refrigerant ent

19、ering the expansion valve and superheated return gas multiplied by the mass flow rate of the refrigerant. 3.7 “Shall“ or “Should“. “Shall” or “should” shall be interpreted as follows: 3.7.1 Shall. Where “shall“ or “shall not“ is used for a provision specified, that provision is mandatory if complian

20、ce with the standard is claimed. Should. “Should,“ is used to indicate provisions which are not mandatory, but which are desirable as good practice. Section 4. Test Requirements 4.1 Test Requirements. All Published Ratings shall be verified by tests conducted in accordance with ASHRAE Standard 23. S

21、ection 5. Rating Requirements 5.1 Standard Ratings. Standard Ratings shall be established at the Standard Rating Conditions in Table 1 and shall include its associated power input and Energy Efficiency Ratio (EER). When tested with a specified motor, the associated compressor speed (external drive c

22、ompressors only) shall also be included as part of the rating. The power required to operate all included accessories such as condenser fans, water pumps, controls, and similar accessories shall be accounted for in the power input and Energy Efficiency Ratio. When external accessories such as water

23、pumps, remote fans, and similar accessories are required for the operation of the unit but not included with the unit, the manufacturer shall clearly state that the rated power input and Energy Efficiency Ratio do not account for additional power required by these external accessories. If a water-co

24、oled condenser is used, the cooling water flow rate and pressure drop shall be specified as part of the rating. 5.2 Application Ratings. Application Ratings shall consist of a Capacity Rating plus the associated power input and Energy Efficiency Ratio (EER). When tested with a specified motor, the a

25、ssociated compressor speed (external drive compressors only), shall also be included as part of the rating. The power required to operate all included accessories such as condenser fans, water pumps, controls, and similar accessories shall be accounted for in the power input and Energy Efficiency Ra

26、tio. When external accessories such as water pumps, remote fans, and similar accessories are required for the operation of the unit but are not included with the unit, the manufacturer shall clearly state that the rated power input and Energy Efficiency Ratio do not account for additional power requ

27、ired by these external accessories. ANSI/AHRI STANDARD 520-2004 3 If a water-cooled condenser is used, the cooling water flow rate and pressure drop shall be specified as part of the rating. All of the above data shall be reported at stated conditions other than those presented in Table 1. Applicati

28、on Ratings shall be reported at rated voltage, phase, and frequency. 5.3 Tolerances. To comply with this standard, measured test results shall not be less than 95% of Published Ratings for capacity and energy efficiency and power input shall be no more than 105% of the rated values. Section 6. Minim

29、um Data Requirements for Published Ratings 6.1 Minimum Data Requirements for Published Ratings. As a minimum, Published Ratings shall include all Standard Ratings. All claims to ratings within the scope of this standard shall include the statement “Rated in accordance with ARI Standard 520”. All cla

30、ims to ratings outside the scope of this standard shall include the statement “Outside the scope of ARI Standard 520”. Wherever Application Ratings are published or printed, they shall include a statement of the conditions at which the ratings apply. Section 7. Operating Requirements 7.1 Maximum Loa

31、ding Conditions. The maximum suction dew point temperature limit shall be published. This limit shall be established with the condensing unit operating at conditions as described below: a. Ambient temperature surrounding the condensing unit of 115F 46.1C dry-bulb for all types, 115F 46.1C dry-bulb a

32、ir temperature entering condenser on air-cooled condensing units, and 80F 27C wet-bulb for evaporatively-cooled condensing units. b. Water inlet temperature of 90F 32C and water outlet temperature of 105F 40.6C for water-cooled condensing units. Make-up water temperature of 90F 32C for evaporatively

33、-cooled units. 7.2 Loading Requirements. The condensing unit shall be capable of operating continuously at the stated maximum loading conditions of 7.1 for a minimum period of two hours at minimum and maximum utilization voltages as described in ARI Standard 110, Table 1. Section 8. Marking and Name

34、plate Data 8.1 Condensing Unit Nameplate Marking. As a minimum, each condensing unit shall have a nameplate, affixed to its housing or base, on which at least the following information shall be marked: a. Manufacturers name and/or symbol b. Model number c. Refrigerant designation per ASHRAE 34 d. In

35、put voltage and frequency (Hz) e. Rated load current (where applicable) Nameplate voltages for 60 Hertz systems shall include one or more of the equipment nameplate voltage ratings shown in Table 1 of ARI Standard 110. Nameplate voltages for 50 Hertz systems shall include one or more of the utilizat

36、ion voltages shown in Table 1 of IEC Standard 60038. Section 9. Conformance Conditions 9.1 Conformance. While conformance with this standard is voluntary, conformance shall not be claimed or implied for products or equipment within the standards Purpose (Section 1) and Scope (Section 2) unless such

37、product claims meet all of the requirements of the standard and all of the testing and rating requirements are measured and reported in complete compliance with the standard. Any product that has not met all the requirements of the standard shall not reference, state, or acknowledge the standard in

38、any written, oral, or electronic communication. ANSI/AHRI STANDARD 520-2004 4 Table 1. AHRI Standard Rating Conditions for Condensing Units for Refrigeration Applications* Suction Dew Point Temperature Com-pressor Type Return Gas Temperature Type of Condensing Unit Air-Cooled Water-Cooled Evaporativ

39、ely- Cooled Air Entering Dry-Bulb (indoor/outdoor) In Out Air Entering Wet-Bulb Temperature Variable Capacity Setting* F C F C F C F C F C F C 45 7.2 All 65 18 90/95 32/35 85 29 95 35 75 24 MAX/MIN 20 -6.7 All* 40/ 65* 4.4/ 18* 90/95 32/35 85 29 95 35 75 24 MAX/MIN -10 -23 Hermetic 40 4.4 90/95 32/3

40、5 85 29 95 35 75 24 MAX/MIN -25 -32 All* 40/ 65* 4.4/ 18* 90/95 32/35 85 29 95 35 75 24 MAX/MIN -40 -40 All* 40/ 65* 4.4/ 18* 90/95 32/35 85 29 95 35 75 24 MAX/MIN * Sub-cooling in F C, shall be stated as obtained under pertinent application conditions, as measured at the liquid line leaving the con

41、densing unit. * 1) For hermetic type compressors, 40F 4.4C return gas temperature shall be used. 2) For external drive and accessible hermetic type compressors, 65F 18C return gas temperature shall be used. * The maximum and minimum capacity setting is the highest and lowest displacement capacity by

42、 the condensing unit. ANSI/AHRI STANDARD 520-2004 5 APPENDIX A. REFERENCES NORMATIVE A1 Listed here are all standards, handbooks and other publications essential to the formation and implementation of the standards. All references in this appendix are considered as part of the standard. A1.1 ANSI/AS

43、HRAE Standard 34-2001 with Addenda, Number Designation and Safety Classification of Refrigerants, 2001, American National Standards Institute/American Society of Heating, Refrigerating and Air-Conditioning Engineers, 11 West 42ndStreet, New York, NY 10036, U.S.A./1791 Tullie Circle N.E., Atlanta, GA

44、 30329, U.S.A. A1.2 AHRI Standard 110-2002 (formerly ARI Standard 110-2002), Air-Conditioning and Refrigerating Equipment Nameplate Voltages, 2002, Air-Conditioning, Heating, and Refrigeration Institute, 2111 Wilson Boulevard, Suite 500, Arlington, VA 22201, U.S.A. A.1.3 ASHRAE Standard 23-1993, Met

45、hods of Testing for Rating Positive Displacement Refrigerant Compressors and Condensing Units, 1993, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., 1791 Tullie Circle, N.E., Atlanta, GA 30329-5478, U.S.A. A1.4 ASHRAE Terminology of Heating, Ventilation, Air Conditio

46、ning and Refrigeration, Second Edition, 1991, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., 1791 Tullie Circle, N.E., Atlanta, GA 30329-5478, U.S.A. A1.5 IEC Standard 60038, IEC Standard Voltages, 2002, International Electrotechnical Commission, 3, rue de Varembe,

47、P.O. Box 131, 1211 Geneva 20, Switzerland. A1.6 ISO 917: 1989, Testing of Refrigerant Compressors, 1989, International Organization for Standardization, Case Postale 56, CH-1211, Geneva 21 Switzerland. APPENDIX B. REFERENCES INFORMATIVE None. ANSI/AHRI STANDARD 520-2004 6 APPENDIX C. METHOD TO HANDL

48、E ZEOTROPIC MIXTURES INFORMATIVE C1 Cycle Process For reference, Figure C1 shows a typical single stage cycle for single component refrigerants and azeotropic mixtures. The description is consistent with the ISO 917 standard. As shown, the evaporating and condensing processes occur at fixed temperat

49、ures to and tc.Figure C1: Cycle Process for Single Component Refrigerants and Azeotropic Mixtures ANSI/AHRI STANDARD 520-2004 7 Figure C2: Cycle Process for Zeotropic Refrigerant Mixtures Figure C2 shows “temperature glide” for zeotropic refrigerant mixtures at the evaporation and condensation processes. Standard reference temperatures are the dew-point temperatures t“0at the evaporating pressure pg1 and t“cat the condensing pressure pg2. The following equations may be used to calculate the mean evaporating