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 theref
2、rom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2011 SAE International All rights reserved. No part of this publication ma
3、y be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-4970 (outside US
4、A) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/J2646_201105SURFACEVEHICLERECOMMENDEDPRACTICEJ2646 MAY2011 Issued 2011-05 Cab Air-Conditioning
5、Test ProcedureHeavy Trucks with and without Sleepers RATIONALENot Applicable. 1. SCOPE This SAE recommended practice establishes a uniform test procedures for on highway trucks equipped with an air-conditioning system used to condition the air in the cabin and sleeper compartment of the vehicle. Thi
6、s specification will apply to heavy trucks with and without sleeper compartments. 1.1 Purpose The purpose is to provide a standard test procedure for comparison and evaluation of heavy truck air-conditioning performance.2. REFERENCES 2.1 Related Publications The following publications are provided f
7、or information purposes and are not a required part of this document. 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. (Body)SAE J1163 Determining Seat Ind
8、ex Point SAE J1559 Measurement of Solar Heating Effect 3. DEFINITIONS 3.1 Air Conditioning System Any system that lowers the cabin and/or sleeper air temperature by the means of a refrigerant. 3.2 Compressor Pumps low pressure refrigerant vapor out of the evaporator by suction, raises the pressure,
9、then pumps it under high pressure into the condenser. SAE J2646 Issued MAY2011 Page 2 of 93.3 Condenser Removes heat from the entering high pressure, high temperature de-superheated vapor refrigerant, changing it to a high pressure, high temperature subcooled liquid refrigerant. 3.4 Expansion Device
10、 Valve, orifice tube, or other expansion device in the refrigerant circuit for the purpose of metering liquid from the condenser into the evaporator inducing a large pressure drop changing the refrigerant to a low temperature, low pressure liquid.3.5 Evaporator Removes unwanted heat from the air by
11、the boiling of liquid refrigerant in the evaporator coil. 3.6 Cab Average Temperature The average of the head, lap and floor temperatures (see Figure 1) measured in both the driver and passenger locations 3.7 Cab Sleeper Average Temperature The average of all measured temperatures inside the sleeper
12、 (see Figure 2) responsible for ensuring even temperature distribution within the sleeper area. 3.8 Ambient Temperature Air temperature measured external to the vehicle and internal to the Vehicle Environmental Chamber. 3.9 Refrigerant Chemical used in a refrigeration system for the purpose of heat
13、transfer. 4. TEST EQUIPMENT 4.1 Vehicle Environmental Chamber (VEC) Environmental chamber large enough to contain the vehicle and test equipment. The chamber must have provisions to maintain ambient temperature, relative humidity, and solar intensity. Chamber capability should maintain the following
14、 levels of accuracy: Temperature: 2 C ( 4 F) Relative Humidity: 3% Solar Load: 50 W/m24.2 Engine Speed Engine tachometer with an accuracy of 2% of observed values. 4.3 Pyranometer A device used to measure radiant energy from the solar load placed horizontal above the vehicle roof surface. 4.4 Temper
15、ature Measurement Devices Devices used to measure temperature inside the VEC as well as inside and outside the vehicle to be used for calculating and comparison of cooling performance, i.e., thermocouples, RTDs, etc. Must have an accuracy of 1.5 C ( 2.7 F). SAE J2646 Issued MAY2011 Page 3 of 94.5 Ai
16、r Velocity/Wind Speed Anemometer to measure air velocity (with a measuring accuracy of 2% of observed values).4.6 Data Acquisition System System that will monitor and record all required test parameters and necessary measured conditions consistent with this specification at the required time interva
17、l. 4.7 Pressure Transducer Device used to measure refrigerant pressure within the refrigeration system that are required within this specification for the purpose of calculating cooling performance. 4.8 Mass Flow Meter Device used to measure the mass flow of refrigerant in the refrigeration system.
18、4.9 Refrigerant Charging and Recovery Station Equipment used to charge the refrigeration system and recover the refrigerant from the refrigeration system. 4.10 Voltage/Current Shunt Device used to measure voltage or current from the HVAC system electrical components. 5. AIR-CONDITIONING TEST VEHICLE
19、 PREPARATION 5.1 Instrumentation/Test Setup 5.1.1 Panel Louver Direction Aim panel louvers towards the occupant, toward the shoulder level of the seats. Aim all other louvers straight ahead. NOTE: All HVAC louvers are open and directed perpendicular to their mounting surface, however none of the lou
20、vers should be directed at any of the thermal probes unless location of the louver is located directly at a probe when adjusted perpendicular to their mounting surface.5.1.2 Vehicle Exterior Ambient Temperature The vehicle test chamber temperature should be measured by 4 exterior thermocouples. Two
21、thermocouples are to be placed along the centerline of the vehicle, way between the ground and the highest point of the vehicle (excluding bolt on items), 915 mm (3 ft) forward of the front of the vehicle and 915 mm (3 ft) away from the back of the vehicle. Left and right side vehicle ambient should
22、 be measured at a point 150 mm (6 inches) away from left side and right side of the vehicle. If a vehicle does not have mirrors, take measurement 450 mm (18 inches) outward from left and right side window.5.1.3 Fresh Air Inlet Temperature A minimum of one temperature measurement device should be ins
23、talled in the fresh air inlet. 5.1.4 Recirc Air Inlet Temperature A minimum of one temperature measurement device should be installed in the recirc air inlet. SAE J2646 Issued MAY2011 Page 4 of 95.1.5 Air Outlet Louver Temperature A minimum of one temperature measurement device should be installed i
24、n the center of all louvers. Install temperature measurement device 19 mm (0.75 inches) into the louver and secured not to block airflow exiting the louver. For larger louvers multiple temperature measurement devices may be used and averaged. 5.1.6 Air Temperature Probe Locations Thermocouples for m
25、easuring cab/sleeper interior temperatures will be used to determine air-conditioning system performance. Additional temperature measurements may be recorded at the discretion of the testing party to achieve further information related to the vehicle air-conditioning system. 5.1.7 Truck Cab Locate t
26、emperature probes at the driver and passenger positions relative to each Seat Index Point (SIP) according to 7.3 (see Figure 1). 5.1.8 Sleeper Cab Locate temperature probes at the sleeper positions according to 7.4 (see Figure 2). 5.1.9 Voltage and Current Measurement Voltage and current measurement
27、 should be taken in all applicable location related to power consumed by HVAC components including; Cab blower motor voltage and current, Sleeper blower motor and Auxiliary condenser fans (if applicable) voltage and current, Compressor clutch- voltage, Engine fan- voltage, thermostat-voltage, Primar
28、y batteries voltage. All measurements taken within 152 mm (6 inches) from the component being measured or as close as possible. Location should be documented.5.2 Refrigeration System Instrumentation 5.2.1 Mass Flow Meter (optional) Install a mass flow meter in the liquid line of the refrigeration sy
29、stem between the condenser outlet and the expansion device or orifice tube. 5.2.2 Refrigerant Temperature Install temperature measurement devices at the inlet and outlet of the compressor, condenser and evaporator coil. All measurements should be taken within 152 mm (6 inches) of the location to be
30、measured or documented if different. 5.2.3 Refrigerant Pressure Install pressure transducer connections at the inlet and outlet of the compressor, condenser and evaporator coil. All measurements should be taken within 152 mm (6 inches) of the location to be measured or documented if different. 5.3 A
31、dditional Instrumentation for Trucks with Sleeper 5.3.1 Sleeper Floor Temperature A minimum of one temperature measurement device per location should be installed according to 7.4 Bunk Probe Locations of this document. 5.3.2 Sleeper Bunk Temperature A minimum of one temperature measurement device pe
32、r location should be installed according to 7.4 Bunk Probe Locations (top and middle of the bunk) of this document. SAE J2646 Issued MAY2011 Page 5 of 95.3.3 Sleeper Louver Air Temperature A minimum of one temperature measurement device should be installed in the center of all louvers. Install tempe
33、rature measurement device 19 mm (0.75 inches) into the louver and secured not to block airflow exiting the louver. For larger louvers multiple temperature measurement devices may be used and averaged. NOTE: All HVAC louvers are open and directed perpendicular to their mounting surface, however none
34、of the louvers should be directed at any of the thermal probes unless location of the louver is located directly at a probe when adjusted perpendicular to their mounting surface.5.4 Vehicle Soak 5.4.1 VEC Ambient 43.3 C 1.7 C (110 F 3 F). 5.4.2 Relative Humidity 40% 3%. 5.4.3 Engine Load None.5.4.4
35、Wind Speed: (Air Velocity) Maximum wind velocity shall not exceed 8 km/hr (5 MPH). 5.4.5 Engine Speed 0 (engine off). 5.4.6 HVAC Controller HVAC system off. 5.4.7 Vehicle windows/doors, hood, cabinet compartment doors, exterior compartment doors, sleeper curtains should be open during the soak perio
36、d, prior to solar loading. 5.4.8 The vehicle shall soak and stand inoperative for a period of 10 hours or until such time as all thermocouples stabilized at a minimum of 43.3 C 1.7 C (110 F 3 F). Minimum soak period of 3 hours. (Soak time should be documented).6. TEST PROCEDURE 6.1 Begin Data Acquis
37、ition prior to solar soak. Check that all channels are reading properly. Set scan rate for 1 minute intervals. Shut all doors, windows, hood, etc. from 5.48. Factory installed cab curtains are open. 6.1.1 Once all temperatures have stabilized at 43.3 C 1.7 C (110 F 3 F) and relative humidity is set
38、to 40% 3% RH, turn solar load on and adjust to 1000 W/m2 50 W/m2. Measure solar load at the roofs surface on the center of the truck cab. Solar soak vehicle until cab interior temperature average (see Figure 1) reach a minimum temperature of 50 C 1.7 C (122 F 3 F) prior to starting the HVAC system a
39、nd vehicle. 6.2 Start vehicle, set engine rpm to 1500 rpm 50 rpm in neutral gear, or the pre-set high idle engine rpm provided as standard by the vehicle OEM, whichever is higher. NOTE: Engine speed shall be maintained with no load (normal engine parasitic loads only) throughout the test.SAE J2646 I
40、ssued MAY2011 Page 6 of 96.3 Maintain wind speed at a maximum wind velocity of no more than 8 km/hr (5 MPH). 6.4 Adjust HVAC controller to recirc inlet air condition, maximum blower speed, turn HVAC systems on. 6.5 Test duration is 150 minutes in the following phases: Phase 1: 60 minutes in recircul
41、ation mode, engine rpm 1500 or preset high idle Phase 2: 30 minute dwell in recirculation mode with no control or engine rpm changes Phase 3: 30 minutes in fresh/air mode, engine rpm 1500 or preset high idle Phase 4: 30 minutes in fresh/air mode, engine rpm reduced to low Idle NOTE: Minimum system v
42、oltage of 13.2 V must be maintained for duration of test as measured at the vehicles primary battery. The test shall be considered invalid if the voltage level drops below 13.2 V. 6.6 Data Reduction/Reporting Graphs A list of suggested graphs for use of comparison of performance and system evaluatio
43、n: Graph 1: Refrigerant pressures Graph 2: Cab Average (all six thermocouples per Figure 1) Graph 3: Upper sleeper Average (all Top and Middle four thermocouples per Figure 2) Graph 4: Lower sleeper Average (two floor thermocouples per Figure 2) Graph 5: Sleeper Average (all six thermocouples pr Fig
44、ure 2) Graph 6: Panel Louver Average Graph 7: Clutch Cycle Graph 8: Condenser/Engine fan cycle 7. PERFORMANCE CRITERIA 7.1 Cab Average Temperature Cab Average occupant temperatures according to Figure 1 should comply with the following criteria: Truck Cab and Crew Cab Phase 1 Goal: Reduce average te
45、mperature from 43.3 C (110 F) to 23.9 C (75 F)Phase 2 Goal: Maintain average temperature 23.9 C (75 F) Phase 3 Goal: Maintain average temperature 26.7 C (80 F) Phase 4 Goal: Maintain average temperature 29.44 C (85 F) 7.2 Sleeper Average Temperature If the vehicle is equipped with a sleeper, sleeper
46、 average temperature based on temperature measured in locations T1-T6 in Figure 2. Sleeper Bunk Phase 1 Goal: Reduce average temperature from 43.3 C (110 F) to 23.9 C (75 F)Phase 2 Goal: Maintain average temperature 23.9 C (75 F) Phase 3 Goal: Maintain average temperature 26.7 C (80 F) Phase 4 Goal:
47、 Maintain average temperature 26.7 C (80 F) SAE J2646 Issued MAY2011 Page 7 of 97.3 Seat Index Point Truck Cab and Crew Cab Locate temperature probes at the driver and passenger positions relative to each Seat Index Point (SIP) per Figure 1. FIGURE 1 - TEMPERATURE PROBE LOCATIONS FOR SEATS SAE J2646
48、 Issued MAY2011 Page 8 of 97.4 Sleeper Cab Probe locations for the sleeper cab to be located according to Table 1 and Figure 2. TABLE 1 - MEASUREMENTS FOR LOCATING BUNK TEMPERATURE PROBES Probe ID Description Horizontal Location Vertical LocationT1 Sleeper Bunk, Passenger Side Top 600 mm from side w
49、all and rear wall 600 mm below ceilingT3 Middle 600 mm from side wall and rear wall 150 mm above mattressT5 Floor 300 mm ahead of bunk, equally spaced between cab wall and T6 300 mm above floorT2 Sleeper Bunk, Driver Side Top 600 mm from side wall and rear wall 600 mm below ceilingT4 Middle 600 mm from side wall and rear wall 150 mm above mattressT
