JB/T 5095-1991 Test method for heat transfer performance of oil cooler for internal combustion engine
Some standard content:
Mechanical Industry Standard of the People's Republic of China
JB/T5095--91
Heat transfer performance of oil cooler for internal combustion engine
Test method
Published on July 1, 1991
Published by the Ministry of Machinery and Electronics Industry of the People's Republic of China
Implemented on July 1, 1992
Mechanical Industry Standard of the People's Republic of China
Heat transfer performance of oil cooler for internal combustion engine
Test method
Subject content and scope of application
JB/T5095--91
This standard specifies the method for determining the inlet and outlet temperature, flow rate and resistance of cold and hot fluids of oil cooler for internal combustion engine (hereinafter referred to as cooler) under given conditions.bZxz.net
This standard is applicable to coolers of various structural types supporting automobiles, tractors, engineering machinery, small ships and generator sets (see Figures 1 to 3).
1991-07-01 Approval of the Ministry of Machinery and Electronics Industry Number of Heat Plates
B-shaped baffle cooler
B-ring disc baffle cooler
Type of heat plate baffle cooler
Double-pass baffle cooler
Tube oil cooler
1992-07-01 Implementation
2 Test parts and devices
The test conditions and devices of the cooler are shown in Figure 4.
JB/T509591
Flat-type oil cooler
Figure 3 Fin structure
The heat medium specified in this standard is No. 11 or No. 14 CD medium-pressure diesel engine oil, and the cold medium is clean water. The cold and hot media can be heated by electricity or other heat sources. The temperature control during the entire heating process must adopt a stepless adjustment device.
JE/T5095-91
Figure 4 Piping diagram of oil cooler test bench
1-Oil tank, 2-electric heater, 3-oil pump, 4-oil tap, 5-pressure gauge, 6-water tank, 7-hydroelectric heater, 8-water pump; 9--water flow regulating valve, 10-wheel flowmeter: 11-oil cooler, 12-differential pressure gauge: 13-wheel flowmeter: 14-water temperature gauge 3 Test instruments, equipment and their requirements
3.1 Flowmeter
The flow of cold and hot media can be measured by wheel flowmeter or other types of flowmeters. The accuracy of the flowmeter should not be lower than Class 1. The turbine flowmeter used to measure the oil flow must have its instrument curve recalibrated according to the oil temperature and flow. The calibration method is shown in Appendix A (Supplement).
3.2 The temperature of cold and hot fluids can be measured by mercury thermometers or other instruments. When using mercury thermometers to measure the inlet and outlet temperatures of cold and hot fluids, the following requirements should be met:
The scale of the mercury thermometer measuring the inlet and outlet temperatures of oil should not be greater than 1/10, and the scale of the mercury thermometer measuring the inlet and outlet temperatures of cooling water should not be greater than 1/50, and the accuracy should not be lower than that of a second-class mercury thermometer. The mercury thermometer should be placed in a temperature bag filled with oil (Figure 5), and the temperature bag should be correctly fixed in a place where the fluid temperature is relatively uniform. b.
3.3 Water side shell
Shell and tube cooler products are composed of core and shell. No water side shell is required for testing. Plate-fin cooler generally only provides core samples. Water side shell must be prepared for testing. Since the gap between the water side shell and the core will affect the reasonable distribution of water flow and flow rate, the experimental data obtained will be very different. Therefore, the following provisions are made for the distance between the water side shell and the core: the distance between the shell and the two sides of the core is K, K,, and the distance between the bottom is K ,, the interval K of the top part should be consistent with the gap between the core pieces (Figure 6).
The water side shell inlet and outlet water pipes should be arranged at both ends of the oil inlet pipe, O
Figure 5 Mercury thermometer and temperature package
3.4 Connection method of test pipeline
JB/T509591
Oil cooling guide
Figure 6 Plate warp cooler core and water side shell The flow mode of cold and hot media in the heat exchanger has several basic types such as downstream, countercurrent, cross flow and their combination. For the multi-pass baffle cooler, the flow mode of cold and hot fluids is mostly determined by the structure of the cooler itself, while the flow mode of cold and hot fluids in the single-pass structure cooler varies with the different test pipeline connection methods. The oil and water inlet pipes are at the same end of the cooler. When the two fluids flow in parallel and in the same direction in the cooler, it is called frequency flow. If the oil and water inlet are at the two ends of the cooler, the two fluids flow in parallel in different directions in the cooler, which is called countercurrent. This standard stipulates that the inlet pipe of the one-way cooler should be connected in the countercurrent direction. 3.5 Differential pressure gauge
When conducting the heat transfer performance test, the pressure difference between the inlet and outlet of the cooler should be measured. This standard recommends the use of a non-pin differential pressure gauge or other differential pressure sensors for measurement.
4 Heat transfer performance test method
4.1 Preparation before the test
4.1.1 After the test piece is installed on the test bench, first check the water side and oil side. It is required that there is no leakage. Then wrap the test piece with insulation material and confirm that the insulation is good.
4.1.2 When the test bench is in operation, the oil inlet temperature of the test piece is 4=95±1℃, the water inlet temperature w=85±1℃ or according to the requirements of the entrusting unit, but the temperature must be stable within the given range, and the temperature change is not more than 0.1℃ per minute. 4.1.3 The water flow rate is within the range of 0.1~1.2m/s, and the oil flow rate is within the range of 0.1~1.2m/s. According to the requirements of the entrusting unit, several different flow rates are selected. 4.2 Test method
First, control the water and oil flow rates at the first level. When the water inlet and oil inlet temperatures meet the requirements of Article 4.1.2, measure the oil inlet and water inlet temperatures, oil outlet and water outlet temperatures, the readings of the oil and water flow meters twice, and the oil side resistance for three consecutive times. Record the seven data in Table 1, take the average of each reading, and calculate the absolute value of the thermal balance error 4. When the absolute value of 4 is greater than the given value, stabilize the working conditions again and measure three consecutive readings again to take the average value and calculate the absolute value of 4, until the absolute value of 4 is less than or equal to the given value, then change the oil flow, and measure the various data of the second level oil flow. According to this method, measure the oil flow data of each level one by one, then change the water flow and stabilize it at the second level water flow, and then change the oil flow remotely one by one to measure the second set of data. In the same way, the data of each group of other water flow rates are inferred. 5. Arrangement of test data
5.1 Engine oil heat release flow Q.
Q. =
Wherein; G=V.
G,epe(t-ta),W
G. ——weight flow rate of engine oil, kg/h; V. —volume flow rate of engine oil, m\/n;
A-density of engine oil.kg/m;
C.-specific heat capacity of engine oil, kJ/(kg·C):te,a—inlet and outlet temperature of engine droplets, C. 5.2 Heat absorption flow rate of cooling water Qw
Wherein: Gw=VwPv
—weight flow rate of water, kg/h;
Vw——volume flow rate of water, m/h;
—density of water, kg/m\;
specific heat capacity of water, kJ/(kg·℃);
twwater inlet and outlet temperatures, ℃.
5.3 Potential balance error4
New product identification and grade assessment:4≤5%
Factory test:
4≤10%
JB/T5095-91
wC.(twl-tw),
·（2)
5.4 Conversion of heat release flow rate Q.
The heat release flow of the oil cooler can only be compared under the same working conditions. Since the inlet temperature is allowed to have a certain deviation during the test, the heat release flow when converted to each oil and water volume at the specified inlet temperature is the converted heat release flow 9. . The following approximate calculation formula can be used for conversion:
Where:
(r- tw.),
-the inlet temperature difference specified before the test (according to the inlet temperature recommended in Article 4.1.2, the inlet temperature difference is 10℃), 5.5 Heat transfer coefficient K., volume utilization coefficient Kv and mass utilization coefficient K. K.
Where: F. 1. Oil side heat transfer area, m
V---cooler core volume, m;
g---cooler core weight, kg:
--logarithmic mean temperature difference, C.
The heat transfer area is calculated according to Appendix B (Supplement). .
For single-pass channel cooler (see Figure 1a, b, Figure 2)Sla = (hu - m) - (ha - bm)
For double-pass channel cooler (see Figure 1c). ne
5.6 Oil speed W and water speed Ww
JB/r5095—91
tw+twe
(foi tua) (ta
o ten
Wherein, V..Vw is the volume flow rate of oil and water, m*/hS..Sw
is the channel area of oil and water, m.
The channel area of oil and water is calculated according to Appendix C (Supplement). 5.7 Draw a curve diagram (see Figure 7),
k, (w/(a\.))
twi+twa
3600Sw
Figure 7 Heat transfer performance curve
SPrkPa
W,im/s?
V,tm*/h
/5095-91
Water flow rate
Oil flow rate
Machine tire
Imported 0
A1 Basic principle of calibration method
JB/T 5095-91
Appendix A
Method for calibrating the instrument curve of a turbine flowmeter for measuring oil flow (supplement)
This method is to stabilize the temperature of the oil within the temperature range required for heat transfer performance, and measure the weight flow rate at different flow rates through the turbine flowmeter.
A2 Calibration method
The calibration method is shown in Figure A1.
Heat the oil in the tank and stabilize the oil temperature within the range of 95±2°C required for heat transfer performance under circulating flow. First, stabilize the instrument reading of the turbine flowmeter at 100Hz twice, rotate the liquid flow reversing switch to allow the return oil to flow to the return oil barrel (Figure A1 The oil passing through the liquid flow reversing switch flows through pipe ① and enters the oil barrel). At the same time, start timing. When the oil barrel is filled with oil, rotate the liquid flow reversing switch to allow the return oil to flow back into the oil tank (Figure A1). The time for the oil to flow through the pipe (barrel after the liquid flow reversing switch is recorded in Table A1, and then adjust the overflow width so that the turbine flowmeter point timing ends at this time. When the net weight of the oil plug and the inflow oil meter readings are stable at 150Hz, repeat the above method and record the results in Table A1. Adjust the overflow valve again so that the turbine flowmeter meter readings are stable at 200Hz. Measure the first point data and fill it into Table AI. And so on. Fill all the measured data into Table A1. Figure A1 Turbine flowmeter instrument curve calibration pipeline diagram 1-Oil barrel: 2-Liquid flow reversing switch 13-Flow reduction valve: 4-Turbine flowmeter, 5-Oil pump: 6-Electric heater: 7-Oiler
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