1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there
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4、0 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/standards.sae.org/J2765_201707 SURFACE VEHICLE STANDARD J2765 JUL2017 Issued 2008-10 Revised 2017-07 Superseding
5、J2765 OCT2008 Procedure for Measuring System COP Coefficient of Performance of a Mobile Air Conditioning System on a Test Bench RATIONALE This revision of this standard has been done to add additional test descriptions for two evaporator systems, systems with chillers, systems with electric compress
6、ors, systems with indirect condensers, and make other improvements. 1. SCOPE 1.1 The impact of mobile air conditioning systems on the environment is becoming more important. Fuel used to power the system impacts both fuel economy of the vehicle and tail pipe emissions of carbon dioxide. 1.2 This Sta
7、ndard applies to mobile air conditioning systems consisting of one or two in-car air coil (evaporator), a compressor, an expansion device, one under-hood air coil (condenser), and either with or without a liquid to refrigerant evaporator (chiller). 1.2.1 This standard can also be used for measuring
8、systems that use electrically driven compressor if measurement of input power to compressor is carefully considered. 1.2.2 This standard can also be used for measuring systems that include the entire air handling system if air side pressure drop for the entire vehicle system is carefully considered.
9、 1.2.3 This standard can also be used for measuring systems that include the entire front end cooling module if air side pressure drop for the entire vehicle system is carefully considered. 1.2.4 This standard can also be used for measuring systems that include a secondary cooling loop if the power
10、to drive the pumps in this system is carefully considered. 1.2.5 This standard can also be used for dual evaporator systems. 1.2.6 This standard can also be used for mobile air conditioning systems with chillers used to condition the battery of an electric vehicle. 1.3 This Standard specifies proced
11、ures, apparatus, and instrumentation that will produce accurate steady state capacity and efficiency data for refrigerant components. 1.4 This Standard does not: 1.4.1 Specify transient test methods, 1.4.2 Make recommendations for safety SAE INTERNATIONAL J2765 JUL2017 Page 2 of 23 1.4.3 Specify tes
12、ts for production, specification compliance, or field testing of mobile air conditioning systems. 1.5 Purpose 1.5.1 This Standard provides a method of testing the capacity (performance) and efficiency (COP) of mobile air conditioning refrigerant systems under steady state conditions. 1.5.2 The proce
13、dure proposed is designed to give maximum repeatability and minimum error in determining cooling capacity (Q) and efficiency (COP Coefficient of Performance) of the refrigeration system of the mobile air conditioner. For that reason a “breadboard” type facility is proposed in which components are as
14、sembled into a system and exposed to operating conditions in individual, separately controlled chambers. The facility should allow for three methods to determine system performance: refrigerant side, airside, and calorimetric chambers. Each side yields its own energy balance calculation to find the
15、capacity of the system. With the three methods used, instead of two as typically required, redundancy will be maintained even when the evaporator refrigerant exit is two phase. In this case only the airside and chamber balances are available. However, the calorimetric chamber is not required provide
16、d the airside heat rejection is properly balanced with the refrigerant side heat rejection. The design should be made so that two independent methods could provide agreement of less than 4.0% between two independent balances. 2. REFERENCES 2.1 Applicable Documents The following publications form a p
17、art of this specification to the extent specified herein. Unless otherwise indicated, the latest issue of SAE publications shall apply. 2.1.1 ASHRAE Publications Available from American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., 1791 Tullie Circle, N.E., Atlanta, GA 3032
18、9-2305, Tel: 404-636-8400, www.ashrae.org. 1 ANSI/ASHRAE Standard 41.1-1986 (RA 2001) Standard Method for Temperature Measurement 2 ANSI/ASHRAE Standard 41.6-1994 (RA 2001) Standard Method for Measurement of Moist Air Properties 3 ASHRAE Standard 41.3-1989 Standard Method for Pressure Measurement 6
19、ASHRAE Standard 41.2-1987 (RA 92) Standard Methods for Laboratory Airflow Measurement 7 ANSI/ASHRAE Standard 51-1999 Laboratory Methods of Testing Fans for Aerodynamic Performance Rating (AMCA Standard 210-99) 8 ANSI/ASHRAE Standard 37-2005 Methods of Testing for Rating Electrically Driven Unitary A
20、ir-Conditioning and Heat Pump Equipment 9 ANSI/ASHRAE Standard 41.4-1996 Standard Method for Measurement of Proportion of Lubricant in Liquid Refrigerant 2.1.2 ASME Publication Available from ASME, P.O. Box 2900, 22 Law Drive, Fairfield, NJ 07007-2900, Tel: 800-843-2763 (U.S./Canada), 001-800-843-27
21、63 (Mexico), 973-882-1170 (outside North America), www.asme.org. 4 Fluid MetersTheir Theory and Application, Sixth Edition, 1971 SAE INTERNATIONAL J2765 JUL2017 Page 3 of 23 2.1.3 ARI Publication Available from Air-Conditioning and Refrigeration Institute, 4100 North Fairfax Drive, Suite 200, Arling
22、ton, VA 22203, Tel: 703-524-8800, www.ari.org. 5 ARI Standard 700-2004 Specifications for Fluorocarbon Refrigerants 2.1.4 NIST Publication Available from NIST, 100 Bureau Drive, Stop 1070, Gaithersburg, MD 20899-1070, Tel: 301-975-6478, www.nist.gov. 10 NIST Standard Reference Database 23 NIST Therm
23、odynamic and Transport Properties of Refrigerants and Refrigerants and Refrigerant MixturesREFPROP 6 3. DEFINITIONS 3.1 AIR, STANDARD Dry air having a mass density of 1.204 kg/m3 (0.075 lb/ft3) which represents the density at 20C at standard barometric pressure defined in section 3.6. 3.2 APPARATUS
24、As used in this standard, this term refers exclusively to test room facilities and instrumentation. 3.3 CAPACITY, TOTAL COOLING The rate, expressed in watts (Btu/hr), at which the equipment removes heat from the air passing through it under specified conditions of operation. 3.4 COP, COEFFICIENT OF
25、PERFORMANCE A measure of the efficiency of an air conditioning system is defined as the average heat removed through the evaporator divided by the average work input to the compressor. Averaging is done using the balances available and/or as described in 7.4.1. This COP is the highest possible becau
26、se it does not account for air movement, heat transmission or other losses of similar nature. 3.4.1 Adjustments to this calculation may be necessary for electrically driven compressors, in case the air handling system is used, in the case of front end cooling module is used, and for secondary coolin
27、g loop systems. 3.5 EQUIPMENT As used in this standard, this term refers exclusively to the mobile air conditioning equipment to be tested. 3.6 PRESSURE, STANDARD BAROMETRIC 101.325 kPa (14.696 psi). 3.7 REFRIGERANT A refrigerant that changes from the liquid to the vapor state in the process of abso
28、rbing heat. 3.8 INDIRECT CONDENSER A condenser that rejects heat from refrigerant to a liquid cooling medium. Also called a water-cooled, liquid-cooled, or secondary loop condenser. SAE INTERNATIONAL J2765 JUL2017 Page 4 of 23 3.9 INDIRECT CONDENSING A method of condensing utilizing a secondary loop
29、, whereby the refrigerant is condensed in the indirect condenser, and the associated heat is then rejected from the coolant to the ambient air via a low-temperature radiator (LTR). 3.10 SHALL OR SHALL NOT Is used to indicate a provision that is mandatory if compliance with the standard is claimed. 3
30、.11 SHOULD, RECOMMENDED OR IT IS RECOMMENDED Is used to indicate provisions which are not mandatory but which are desirable as good practice. 4. INSTRUMENTATION 4.1 Temperature Measuring Instruments 4.1.1 All temperature measurements (with the exception of dew point temperature) shall be made in acc
31、ordance with ANSI/ASHRAE Standard 41.1-1986 (RA 2001).1 4.1.2 If used in determining the water vapor content of the air, dew point hygrometers shall be applied as specified in ANSI/ASHRAE Standard 41.6-1994 (RA 2001)2 and shall be accurate to within 0.2 C (0.4 F). 4.1.3 Inlet air temperature measure
32、ments are to be taken upstream of static pressure taps on the inlet duct (if installed). Outlet air temperature measurements shall be taken downstream of the static pressure taps on the outlet. Very often the best practice is to take temperature immediately downstream of the nozzle throat. 4.2 Press
33、ure Measuring Instruments 4.2.1 Pressure measurements shall be made with any device meeting the requirements of ASHRAE 41.3-1989.3 4.2.2 The accuracy of pressure measuring instruments shall permit measurement to within 1.0% full scale. 4.3 Air Differential Pressure and Airflow Measurements4 4.3.1 Th
34、e static pressure difference across nozzles and velocity pressures at nozzle throats shall be measured with manometers or electronic pressure transducers that have been calibrated against a pressure standard to within 1.0% of the reading. The resolution of the device shall be equal to or less than 2
35、.0% of the reading. 4.3.2 Areas of nozzles shall be determined by measuring their diameters to within 0.20% in four places approximately equally spaced around the nozzle in each of two planes through the nozzle throat, one at the outlet and the other in the straight section near the radius. 4.4 Elec
36、trical Instruments 4.4.1 Electrical measurements shall be made with indicating or integrating instruments. 4.4.2 Instruments used for measuring the electrical power input to fan motors or other equipment accessories shall be accurate to within 0.5% of the reading for voltage, and 1.0% of reading for
37、 current measured by shunt. 4.4.3 Voltages shall be measured at the equipment terminals. Instruments used for measuring voltage shall be accurate to within 0.5% of the reading. 4.5 Refrigerant Flow Measurement 4.5.1 Refrigerant flow shall be measured with an integrating flow measuring system that is
38、 accurate to within 1.0% of the reading SAE INTERNATIONAL J2765 JUL2017 Page 5 of 23 4.6 Latent Heat Transfer Measurement Latent heat transfer can be measured via condensation collection or outlet humidity measurement vs. the inlet humidity condition. 4.6.1 Condensate collection rates shall be deter
39、mined using a liquid quantity meter that is accurate to within 0.5% of the reading or other method that provides the same accuracy. 4.6.2 Latent load can also be determined via dew-point measurement on the downstream side of the evaporator capable of 1% Relative Humidity or the use of dry-bulb/wet-b
40、ulb temperature measurements accurate to within 0.2K. 4.7 Coolant Flow Measurement Equipment 4.7.1 Coolant flow meters shall be measured using volumetric flow accurate to 0.2% of actual value. 4.8 Speed Measuring Instruments 4.8.1 Speed measurements shall be made with a revolution counter, tachomete
41、r, stroboscope, or oscilloscope that is accurate to within 1.0% of the reading. 4.9 Time and Mass Measurements 4.9.1 Time interval measurements shall be made with an instrument that is accurate to within 0.2% of reading. 4.9.2 Mass Measurement shall be made with an apparatus that is accurate to with
42、in 1.0% of reading. 4.10 Torque Measurements 4.10.1 Torque measurements shall be made with an instrument that is accurate to within 2.0% of reading. 4.11 Refrigerant mass composition measurements for refrigerant mixtures shall be made using an instrument that is in accordance with ARI Standard 700-2
43、004.5 5. TEST FACILITY AND MEASURING APPARATUS 5.1 Test Facility (Figure 1) Recommended configurations for the test facility are provided below. In all cases, suitable means for determining the dry-bulb temperature and water vapor content of the air entering and leaving the heat exchangers shall be
44、provided. SAE INTERNATIONAL J2765 JUL2017 Page 6 of 23 Figure 1A - Sample test facility closed bench Figure 1B - Sample test facility open bench Figure 1 Evaporator Test Section Condenser Test Section SAE INTERNATIONAL J2765 JUL2017 Page 7 of 23 5.2 Test Room Requirements 5.2.1 Typically, two test r
45、ooms are required; an in car room and an under-hood room. If desired, a third room may be used for the compressor to simulate under-hood conditions. That room can be located either outside or in the under-hood room. 5.2.2 An in car condition test room is required. This may be any room or space in wh
46、ich the desired test conditions can be maintained within the tolerances given in Table 1. 5.2.3 An under-hood test room is required. This may be any room or space in which the desired test conditions can be maintained within the tolerances given in Table 1. A condenser wind tunnel may be substituted
47、 for the under-hood test room provided it is capable of maintaining the conditions given in Table 1. Table 1 - Permissible variations in test conditions Controlled Test Parameter Operating Tolerance(1) Condition Tolerance(2) Evaporator inlet air dry-bulb temperature (C) 0.5 0.3 Evaporator inlet air
48、humidity (%) 3 1 Evaporator air flow rate (kg/min) 0.3 0.1 Targeted air temp. downstream of evaporator (C) 0.5 0.3 Condenser inlet air dry-bulb temperature (C) 0.5 0.3 Condenser face air velocity (m/s) 0.18 0.06 Compressor speed (rpm) 2 1 1. Operating Tolerance is the maximum permissible range of an
49、y measurement. 2. Condition Tolerance is the maximum permissible variation of the average value of the measurement from the specified test condition. 5.3 Wind Tunnels for Heat Exchangers 5.3.1 To produce repeatable and comparable results, it is recommended to control the inlet air temperature and velocity profile across the face of the test heat exchangers. 5.3.2 Below is an example of one setup tha
