AHRI 571 SI-2012 Performance Rating of Positive Displacement Carbon Dioxide Refrigerant Compressors and Compressor Units.pdf

1、 2012 Standard for Performance Rating of Positive Displacement Carbon Dioxide Refrigerant Compressors and Compressor Units AHRI Standard 571 (SI) Price $10.00 (M) $20.00 (NM) Copyright 2012, by Air-Conditioning, Heating and Refrigeration Institute Printed in U.S.A. Registered United States Patent an

2、d Trademark Office 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 produc

3、ts be designed, 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 accept

4、ed industry practices. AHRI does not certify or guarantee that any tests conducted under its standards/guidelines will be non-hazardous or free from risk. This standard is a new standard. For I-P ratings, see AHRI Standard 570 (I-P)-2012. TABLE OF CONTENTS SECTION PAGE Section 1. Purpose .1 Section

5、2. Scope 1 Section 3. Definitions1 Section 4. Test Requirements .3 Section 5. Rating Requirements 3 Section 6. Minimum Data Requirements for Published Ratings 4 Section 7. Operating Requirements 6 Section 8. Marking and Nameplate Data 6 Section 9. Conformance Conditions .6 TABLES Table 1. Standard R

6、ating Conditions for CO2Compressors and Compressor Units for Refrigeration Applications 7 APPENDICES Appendix A. References Normative .8 Appendix B. References Informative .8 Appendix C. Method of Test for Transcritical and Two Stage Subcritical Cycles Normative 9 FIGURES FOR APPENDICES Figure C1. S

7、ingle Stage Refrigeration Cycle Schematic with Thermodynamic State Point Numbers .10 Figure C2. Single Stage Pressure Versus Enthalpy Diagram for the Refrigeration Cycle Shown in Figure C1 .11 Figure C3. Two Stage Refrigeration Cycle Schematic with Thermodynamic State Point Numbers 11 Figure C4. Two

8、 Stage Pressure Versus Enthalpy Diagram for the Refrigeration Cycle Shown in Figure C3 .12 Figure C5. Cycle Process for Subcritical Applications (AHRI Standard 571 Method 1) 22 Figure C6. Cycle Process for Transcritical Applications (AHRI Standard 571 Method 1).23 Figure C7. Cycle Process for Subcri

9、tical Application for Compressor Units with Manufacturer Specified or Supplied Subcoolers (AHRI Standard 571 Method 2) 23 Figure C8. Cycle Process for Transcritical Application for Compressor Units with Manufacturer Specified or Supplied Subcoolers (AHRI Standard 571 Method 2) .24 Figure C9. Cycle P

10、rocess for Subcritical Application for Compressors Applied with Non-Specified Subcoolers (AHRI Standard 571 Method 3) .24 Figure C10. Cycle Process for Transcritical Application for Compressors Applied with Non-Specified Subcoolers (AHRI Standard 571 Method 3) .25 Figure C11. Cycle Process for Subcr

11、itical Applications for Compressors and Compressor Units Applied with Open Flash Style Liquid Subcoolers (AHRI Standard 571 Method 4) .25 Figure C12. Cycle Process for Transcritical Applications for Compressors and Compressor Units Applied with Open Flash Style Liquid Subcoolers (AHRI Standard 571 M

12、ethod 4) .26 AHRI STANDARD 571 (SI)-2012 1 PERFORMANCE RATING OF POSITIVE DISPLACEMENT CARBON DIOXIDE REFRIGERANT COMPRESSORS AND COMPRESSOR UNITS Section 1. Purpose 1.1 Purpose. The purpose of this standard is to establish for positive displacement carbon dioxide refrigerant compressors and compres

13、sor units: 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, engineers

14、, installers, 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, single and two stage Positive Displacement Refrigerant C

15、ompressors and Compressor Units operating with carbon dioxide in both Subcritical and Transcritical applications for refrigeration. This standard also applies to the presentation of performance data for Positive Displacement Compressors and Compressor Units operating with carbon dioxide. 2.1.1 Refri

16、gerant. The rating points in this standard are based on R-744 (carbon dioxide). 2.2 Exclusions. 2.2.1 This standard does not apply to compressors and compressor units intended for use in: 2.2.1.1 Household refrigerators and freezers 2.2.1.2 Automotive air-conditioners 2.2.1.3 Dehumidifiers 2.2.1.4 I

17、ndustrial products other than heating and cooling 2.2.2 This standard does not apply to compressors that are coupled with condensers or gas cooler heat exchangers. 2.2.3 This standard does not apply to carbon dioxide compressors used in heat pump and air-conditioning applications. Section 3. Definit

18、ions All terms in this document will 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 (COP). A ratio of the cooling capacity in wa

19、tts (W) to the power input value in watts (W) at any given set of Rating Conditions expressed in watts/watt, W/W. 3.2 Compressor Efficiency or Compressor Unit Efficiency. A ratio of theoretical to actual power as defined in Appendix C. 3.3 Positive Displacement Refrigerant Compressor. A machine in w

20、hich an increase in refrigerant vapor pressure is attained by changing the internal volume of the compression chamber through work applied to the compressors mechanism. AHRI STANDARD 571 (SI)-2012 2 This shall include desuperheaters, head fans or other accessories required to sustain operation of th

21、e compressor at the Rating Conditions. 3.3.1 Hermetic Refrigerant Compressor. A compressor and motor assembly, both of which are enclosed in the same housing, with the motor operating in the refrigerant. 3.3.2 Semi-Hermetic Refrigerant Compressor. A compressor and motor assembly contained within a g

22、as-tight housing that contains sealed joints to provide access for servicing internal parts. 3.3.3 Open Drive Compressor. A refrigerant compressor with a shaft or other moving part extending through its casing to be driven by an external source of power. 3.4 Positive Displacement Refrigerant Compres

23、sor. A Positive Displacement Refrigerant Compressor(s) with accessories, such as condensers, gas coolers, interstage coolers, desuperheaters, head fans, strainers, service valves, check valves, suction filters, oil separators, external power source (for Open Drive Refrigerant Compressor), as provide

24、d by the manufacturer. This will also include variable capacity controls, electronic or electro-mechanical, as supplied or specified by the manufacturer. 3.5 Power Input. The time rate of energy usage of the compressor (compressor power) or compressor unit (compressor unit power). 3.6 Published Rati

25、ng. 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 (identification) produced by the same manufacturer. The term Published Rati

26、ng 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. 3.6.1 Application Rating. A rating based on tests performed at application Rating Conditions (other

27、 than Standard Rating Conditions). 3.6.2 Standard Rating. A rating based on tests performed at Standard Rating Conditions. 3.7 Rating Conditions. Any set of operating conditions under which a single level of performance results and which causes only that level of performance to occur. 3.7.1 Standard

28、 Rating Conditions. Rating Conditions used as the basis of comparison for performance characteristics. 3.8 Refrigerating Capacity. The capacity associated with the increase in total enthalpy between the refrigerant entering the evaporator and the superheated return gas entering the compressor. Paras

29、itic heat transfer effects shall not be included in the calculation of Refrigerating Capacity (W). 3.9 “Shall“ or “Should,“ shall be interpreted as follows: 3.9.1 Shall. Where “shall“ or “shall not“ is used for a provision specified, that provision is mandatory if compliance with the standard is cla

30、imed. 3.9.2 Should. “Should“ is used to indicate provisions which are not mandatory, but which are desirable as good practice. 3.10 Single Stage Compressor. A compressor that has one or more compression chambers and it has only two ports for refrigerant communication with the refrigeration system: a

31、 low pressure suction port and a high pressure discharge port. A Single Stage Compressor may or may not have refrigerant injection. 3.11 Subcritical Cycle. A refrigeration cycle where the transfer of heat from the low-temperature reservoir and transfer of heat to the high-temperature reservoir both

32、occur at pressures lower than the critical pressure of the refrigerant. AHRI STANDARD 571 (SI)-2012 3 3.12 Transcritical Cycle. A refrigeration cycle where the transfer of heat from the low-temperature reservoir occurs at a pressure lower than the critical pressure of the refrigerant and transfer of

33、 heat to the high-temperature reservoir occurs at a pressure higher than the critical pressure of the refrigerant. 3.13 Two Stage Compressor. A compressor that has one or more compression chambers and has at least three refrigerant communication ports: a low pressure suction port, a high pressure di

34、scharge port, and at least a third, intermediate pressure inlet, port. When the term intermediate port is used for refrigerant injection, for the sole purpose of controlling discharge gas temperature, the compressor shall be considered a Single Stage Compressor. Section 4. Test Requirements 4.1 Test

35、 Requirements. All Published Ratings shall be verified by tests conducted in accordance with Appendix C for transcritical applications and ASHRAE Standard 23.1 for subcritical applications. 4.2 Ambient Temperature. The ambient temperature specified in AHRI Standard 571 (SI) may be different than the

36、 value in ASHRAE Standard 23.1. For the purpose of rating to AHRI Standard 571 (SI), the ambient temperature specified herein shall supersede any requirement in ASHRAE Standard 23.1. Section 5. Rating Requirements 5.1 Standard Ratings. The Standard Ratings of a compressor or compressor unit shall co

37、nsist of a refrigerating capacity rating, W, mass flow rate rating, kg/s, power input rating, W, and COP, identified at the Standard Rating Conditions, when tested as specified in Section 4. 5.1.1 Standard Rating of a Refrigeration Compressor or Compressor Unit. The rating when operated at one of th

38、e Standard Rating Conditions presented in Table 1. 5.2 Application Ratings of Compressor and Compressor Units. Application Ratings shall consist of a refrigerating capacity rating, W, mass flow rate rating, kg/s, power input rating, W, and COP when tested at stated conditions other than those presen

39、ted in Table 1, as specified by the manufacturer. 5.3 Nameplate Voltages for Rating. Rating tests shall be performed at the nameplate rated voltage and frequency. For dual nameplate voltage ratings, rating tests shall be performed at both voltages, or at the higher of the two voltages, if only a sin

40、gle rating is to be published. 5.4 Tolerances. To comply with this standard, measured test results shall not be less than 90% of Published Ratings for Refrigerating Capacity (or mass flow), shall not be more than 105% of Published Ratings for Power Input and shall not be less than 90% of Published R

41、atings for COP. 5.5 Rating Methods. Compressors or compressor units shall be rated in one of four ways described below. Manufacturers shall declare which rating method is used when providing Published Ratings. 5.5.1 Method 1: Standard Applications. This test method should be referenced as “AHRI Stan

42、dard 571 (SI) Method 1” Subcritical Cycles: Under this rating method, manufacturers shall report Refrigerating Capacity at condenser exit subcooling specified in Table 1. Refer to Figure C5 Transcritical Cycles: Under this rating method, manufacturers shall report Refrigerating Capacity at the gas c

43、ooler exit temperature specified in Table 1. Refer to Figure C6 5.5.2 Method 2: Compressor Units with Manufacturer Specified or Supplied Subcoolers Only. This test method should be referenced as “AHRI Standard 571 (SI) Method 2” AHRI STANDARD 571 (SI)-2012 4 Subcritical Cycles: Under this rating met

44、hod, manufacturers shall report Refrigerating Capacity including the increased refrigeration effect provided by the manufacturer specified or supplied subcooler. Note: Liquid entering the subcooler shall be at the condenser exit subcooling specified in Table 1. Refer to Figure C7 Transcritical Cycle

45、s: Under this rating method, manufacturers shall report Refrigerating Capacity including the increased refrigeration effect provided by the manufacturer specified or supplied subcooler. Note: Fluid entering the subcooler shall be at the gas cooler exit temperature specified in Table 1. Refer to Figu

46、re C8 5.5.3 Method 3: Compressors Applied with Non-Specified Subcoolers. This test method should be referenced as “AHRI Standard 571 Method 3” Subcritical Cycles: Under this rating method, manufacturers shall report Refrigerating Capacity including increased refrigeration effect provided by the subc

47、ooler. Note: Liquid entering the subcooler shall be at the condenser exit subcooling specified in Table 1. Liquid temperature leaving the subcooler shall be 5 K above the saturated intermediate temperature. Refer to Figure C9 Transcritical Cycles: Under this rating method, manufacturers shall report

48、 Refrigerating Capacity including increased refrigeration effect provided by the subcooler. Note: Fluid entering the subcooler shall be at the gas cooler exit temperature specified in Table 1. Liquid temperature leaving the subcooler shall be 5 K above the saturated intermediate temperature. Refer t

49、o Figure C10 5.5.4. Method 4: Compressors or Compressor Units Applied with Open Flash Style Liquid Subcoolers. This test method should be referenced as “AHRI Standard 571 Method 4.” Subcritical Cycles: Under this rating method, manufacturers shall report Refrigerating Capacity including increased refrigeration effect provided by the subcooler. Note: Liquid entering the subcooler shall be at the condenser exit subcooling specified in Table 1. Liquid temperature leaving the subcooler shall be equal to the saturated intermediate temperature. Refer to Figure C11 Transcri