1、 WORLDWIDE ENGINEERING STANDARDS Test Procedure GMW15808 Coolant System Bench Evaluation Copyright 2013 General Motors Company All Rights Reserved May 2013 Page 1 of 8 1 Scope Note: Nothing in this standard supercedes applicable laws and regulations. Note: In the event of conflict between the Englis
2、h and domestic language, the English language shall take precedence. 1.1 Purpose. To determine if the total coolant flow, flow to the radiator, flow to the heater, flow balance in V-engines, and flow in any other branch of a cooling circuit, meets the design intent under various thermostat opening c
3、onditions. To provide hydraulic restriction (pressure drop vs. flow characteristics) data for cooling system modeling and to provide model validation. To ensure surge tank function under dynamic conditions, such as maximum engine speed. To determine the necessity for a second degassing line. 1.2 For
4、eword. This is a bench coolant flow test procedure used for coolant system development. 1.3 Applicability. All liquid cooled engines. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. None 2.2 GM Standards/Specific
5、ations. None 2.3 Additional References. CG2263: GMW15808 Data Sheet 3 Resources 3.1 Facilities. A component test lab or “flow bench“ is normally used to complete this test. 3.1.1 Calibration. The test facilities and equipment shall be in good working order and shall have a valid calibration label. 3
6、.1.2 Alternatives. Alternative test facilities and equipment may also be used. However, all measuring variables as specified in this standard shall be determined correctly with respect to their physical definition. 3.2 Equipment. 3.2.1 Basic Machine. A speed controlled electric motor with capacity t
7、o drive the water pump to approximately 1000 rpm above the equivalent peak engine speed. (Recommend 10 kW at 10 000 rpm, however, some North American applications may require as much as 12 kW at 10 000 rpm.) 3.2.2 Fixturing. T-slot table to hold an engine block, heads, water pump, radiator, heater c
8、ore, hoses, any additional cooling circuit components and flow meters. 3.2.3 Instrumentation. 3.2.3.1 Magnetic flow meters, sized for appropriate flow rate with minimum pressure drop. Flow rates in various branches of the cooling circuit can range from 150 liters per minute (lpm) down to 10 lpm. 3.2
9、.3.2 Torque transducer with speed (rpm) output. Depending on pump size, the torque can range from less than 1.0 Nm to 10 Nm. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM
10、 WORLDWIDE ENGINEERING STANDARDS GMW15808 Copyright 2013 General Motors Company All Rights Reserved May 2013 Page 2 of 8 3.2.3.3 Thermocouples and pressure transducers. Expected temperatures are in the range from 15 C to 120 C. Expected pressures range from -60 kPa to +850 kPa (for large V-8s) with
11、respect to atmosphere. 3.2.3.4 Glass coolant sight tubes. 3.2.3.5 Data acquisition system. 3.2.4 Coolant Heater. An electric coolant heater is required to raise the coolant temperature to 95 C for testing. If an external heating circuit is used, this circuit must have valves to isolate the heater du
12、ring test operation. 3.3 Test Components. A representative block, cylinder head, water pump, thermostat housing, and any additional cooling circuit components from the engine are required. Production-intent cooling components such as radiator, heater core, surge tank/coolant recovery bottle, hoses,
13、and any additional components to complete the cooling circuit are required. If any of the system components are electrically powered then an appropriate power supply is needed. If any components are actively controlled then means for providing a control signal, e.g., a signal generator, is required.
14、 3.4 Test Time. Calendar time: 15 days Test hours: 15 hours Coordination hours: 25 hours 3.5 Test Required Information. List of engine and coolant system part numbers Coolant system layout Power supply and control signal specifications 3.6 Personnel/Skills. Technician must be skilled in test set up,
15、 instrumentation and test operation. 4 Procedure 4.1 Preparation. 4.1.1 Install taps in the water pump or fixture for inlet and outlet pressure. In the case of a pump with a double volute, the pressure should be measured in each outlet. 4.1.2 Install pressure taps in the radiator inlet and outlet an
16、d the heater inlet and outlet. 4.1.3 Install a pressure tap in the pressurized recovery bottle or near the pressure relief cap in an unpressurized recovery system. This provides a measurement of system reference pressure. 4.1.4 Install pressure taps in the following engine locations (if applicable).
17、 Note that in some cases, there will be two measurement locations separated only by a length of hose. This is deliberate and necessary to account for the pressure loss due to each component, including hoses. Engine outlet or outlets, if different for radiator, bypass, heater, or oil cooler circuits
18、Crossover outlet or outlets Thermostat assembly locations, both in and out, can vary depending on the type of thermostat and complexity of the thermostat assembly. The intention is to characterize the pressure drop and flows in the thermostat housing and mixing area Heater return port Other location
19、s depending on complexity of the system and requestors requirements. For example, additional locations on the block and head may be needed to characterize the pressure drop through the block, head gasket, and head. A list of possible measurement locations may be found in Appendix A, Table A1. 4.1.5
20、Add sight glass tubes to all of the coolant hoses to determine coolant flow direction and level of aeration. 4.1.6 Prepare a production-intent thermostat that can accurately be adjusted for opening between fully open and closed, or four thermostats with fixed openings of approximately 1 mm, 3 mm, 5
21、mm and full open. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW15808 Copyright 2013 General Motors Company All Rights Reserved May 201
22、3 Page 3 of 8 4.1.7 Cycle another production intent thermostat either mechanically or thermally from closed to full open five times. This thermostat will be used for the “closed thermostat“ tests. Previous experiences with some thermostats suggest that the spring load relaxes after several cycles. T
23、his is of importance in inlet-side thermostats where the spring load may be overcome by the hydraulic pressure differential at high engine speeds. As a result, the thermostat is “pushed“ open. 4.1.8 If any of the components are electrically powered, install instrumentation to measure the voltage and
24、 current supplied. 4.2 Conditions. 4.2.1 Environmental Conditions. Not applicable. 4.2.2 Test Conditions. Deviations from the requirements of this standard shall have been agreed upon. Such requirements shall be specified on component drawings, test certificates, reports, etc. 4.2.2.1 Mount the engi
25、ne and platform released components on the test fixture. 4.2.2.2 Mount the platform components in relative height to design intent with respect to the water pump centerline. 4.2.2.3 Avoid sharp bends, abrupt transitions, and flow restrictions in the hoses. 4.2.2.4 Remotely mount the water pump for V
26、-engines so that flow meters can be mounted between the pump and block to obtain flow in each leg. 4.2.2.5 Include flow meters in any bypass system (if feasible). 4.2.2.6 Install flow meters in the radiator inlet, radiator outlet, heater inlet, surge tank vent line, and surge tank return line (if ap
27、plicable), as well as in any other branches of the cooling circuit. For example, a flow meter should be installed in turbocharger bearing cooling lines, if applicable. 4.2.2.7 Fill the system with a 50/50 mixture of DEX-COOL and water. Be sure to measure the installed volume of coolant 4.2.2.8 Insta
28、ll the pressure relief cap and introduce coolant into the system (radiator or engine block are good choices) until the system pressure comes up to relief pressure. The pressure cap may be disabled to allow pressure regulation with an external (shop) air source. 4.2.2.9 De-aerate the system. 4.2.2.10
29、 Take pictures of the setup views from various sides to keep records of bench system setup including instrumentations and plumbing details. 4.3 Instructions. 4.3.1 Baseline Run. 4.3.1.1 Heat the coolant to 95 C. Apply and maintain constant pressure under the relief cap with regulated shop air. 4.3.1
30、.2 Record system data at pump speeds from 500 rpm to maximum pump speed in 500 rpm 20 rpm increments for each of the conditions described below (reference CG2263). 4.3.1.2.1 Fully open thermostat and apply either 100 kPa or 140 kPa pressure under the surge cap to match the production intent relief p
31、ressure. 4.3.1.2.2 Closed thermostat, coolant at 5 C to 10 C below the thermostat start-to-open (STO) temperature, and 55 kPa under the surge cap. 4.3.1.2.3 (Optional). Fully open thermostat with coolant at approximately 95 C and the range of system pressures: 100 kPa, 50 kPa and 0 kPa. This allows
32、an assessment of the system tendency to cavitate under hot ambient conditions. 4.3.1.2.4 (Optional). Obtain thermostats with openings fixed at 1 mm, 3 mm, and 5 mm. Alternatively, prepare a thermostat so that the opening can be changed externally from 1.0 mm to 5.0 mm. Evaluate fixed opening thermos
33、tats of approximately 1 mm, 3 mm and 5 mm. Coolant should be at 95 C and the pressure should be either 100 kPa or 140 kPa under the relief cap. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without lice
34、nse from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW15808 Copyright 2013 General Motors Company All Rights Reserved May 2013 Page 4 of 8 4.3.1.3 (Optional) Reduced Coolant Level. Repeat 4.3.1.2 with reduced coolant level. Note the status of the low coolant level sensor, if present. 4.3.1.3.1 Inst
35、all a fully open thermostat. Remove 5.0% of the coolant from the coolant system (round off to the nearest 0.1 L). Use the radiator drain, if equipped. If not, remove the coolant from the surge tank. 4.3.1.3.2 Remove an additional 5% of the coolant from the system (round off to the nearest 0.1 L). 4.
36、4 Service Fill De-aeration (Surge Tank Systems). 4.4.1 Drain all of the coolant from the system, including the engine. 4.4.2 Install an open thermostat or install the variable thermostat from 4.3.1.2.4. If an open thermostat is used, clamp the upper radiator hose to prevent flow to the radiator. If
37、a variable thermostat is used, set it to “closed“. 4.4.3 Set a clock timer. Fill the system to the “Full Cold“ mark on the surge tank. Do not exceed five minutes on the timer. Stop and reset the timer. 4.4.4 Open radiator hose clamp or set the variable thermostat to 1.0 mm, start the timer, and run
38、the coolant pump at 1000 rpm for five minutes. Stop and reset the timer. 4.4.5 Add the remaining coolant to the surge tank, or coolant system fill point. 4.4.6 Install the pressure cap. With the thermostat still at 1.0 mm open, start the timer, and run the coolant pump at 1000 rpm until all sight gl
39、asses are either clear or match the original data from 4.3.1.2. Record time. 5 Data 5.1 Calculations. See Appendix B, Section B1 for coolant pump power and efficiency calculations. 5.1.1 Flows (plot against Water Pump Speed). Each leg of the water pump (V-engines only) Radiator inlet (engine out) He
40、ater core Bypass (if external to engine) Surge tank outlet Other components (oil cooler, turbo, heated throttle body, etc.) 5.1.2 Temperatures. Water pump inlet 5.1.3 Pressures (plot against Water Pump Speed). Water pump inlet Water pump outlet or outlets Radiator in and out Heater in and out Cylind
41、er head locations specified by requester Cylinder block locations specified by requester 5.1.4 Torque required “to drive“ the water pump. 5.1.5 Coolant flow direction and aeration level for all sight glass tubes. 5.2 Interpretation of Results. 5.2.1 Flow. 5.2.1.1 Was the flow balance between the leg
42、s of the pump within 10% for all operating conditions (V-engines)? 5.2.1.2 Did the flow to the radiator meet or exceed requirements at the target speeds? Did the maximum flow to the radiator exceed the maximum limit? 5.2.1.3 Did the closed thermostat flow to the heater meet or exceed the requirement
43、 at the target speed? Did the flow to the heater exceed the maximum allowable at any condition? Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDA
44、RDS GMW15808 Copyright 2013 General Motors Company All Rights Reserved May 2013 Page 5 of 8 5.2.1.4 Did the “closed thermostat“ pull open (seen as an abrupt increase in flow to the radiator)? This is a potential problem with inlet side thermostats where the pressure differential across the valve act
45、s to open it. The main spring must have enough preload to prevent the valve opening. 5.2.1.5 Were there any significant deviations from a straight line relationship between total flow and speed at any of the conditions tested? This may indicate cavitation of the pump or the opening of bypass passage
46、s. 5.2.1.6 Were the visible flow direction observations consistent with design intent? Did the coolant appear to be aerated? Did the flow rate into the surge tank appear to be too high, causing aeration? 5.2.1.7 Was there any heater “gurgle“ or other flow related noises detected? 5.2.2 Pressure. 5.2
47、.2.1 Did the pressure in the radiator or heater core exceed the maximum allowable at any condition? 5.2.2.2 Did the inlet pressure to the pump go significantly negative at any condition? 5.2.3 Power. 5.2.3.1 Does the power required to drive the pump meet the accessory drive design capability or a po
48、wer target? 5.3 Test Documentation. Data from this test is normally captured electronically. A summary data file must be stored in the Global Document Management (GDM) system after approval by the requesting engineer. 6 Safety This Engineering Standard may involve safety requirements for hazardous m
49、aterials, the method of operations and equipment. This standard does not propose to address all the safety issues associated with its use. It is the responsibility of the user of this standard to ensure compliance with all appropriate safety and health practices. This would include any specific training that may be required. The safety and health standards include site specific rules and procedures, corporate r
