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Mechanical Industry Standard of the People's Republic of China
JB/T 5143 -1991
Carburettor Integrated Flow Test Bench
Test Method
Published on 1991-06-26
Implementation by the Ministry of Machinery and Electronics Industry of the People's Republic of China on 1992-07-01
Mechanical Industry Standard of the People's Republic of China
Carburettor Integrated Flow Test Bench
Test Method
Subject Content and Scope of Application
This standard specifies the test method and test procedure for the carburettor integrated flow test bench. This standard applies to the carburettor integrated flow test bench for measuring air flow with sonic nozzles. 2 Reference Standards
JJG235 Gear Flowmeter Verification Procedure
JJG257 Glass Rotor Flowmeter Verification Procedure 3 Test Method
The product should be tested item by item according to the items and procedures specified in this standard. 3.1 Air flow test
Use the standard sonic nozzle to measure the nozzle of the device. The specific method and calculation formula are as follows. JB/T 5143 -1991
3.1.1 Prepare a 0~0.1MPa standard atmospheric pressure gauge, a hygrometer, a standard mercury thermometer, a 0~-0.1MPa standard mercury pressure gauge, a set of nozzle calibration equipment and a set of standard sonic nozzles. 3.1.2 Connect the instruments according to Figure 1. www.bzxz.net
Spray environment calibration device
Thermometer
Atmospheric pressure gauge (ps)
Standard nozzle
Inhalation negative pressure gauge
Device nozzle
Standard mercury thermometer (t,)
Back cavity negative pressure gauge
Air temperature measuring instrument (tz)
Standard mercury pressure
Negative pressure trap
Figure 1 Schematic diagram of air flow detection
3.1.3 Install the standard nozzle on the nozzle calibration device. The nominal values of the standard nozzle and the device nozzle are basically configured in a 1:2 relationship. 3.1.4
Based on the calibration flow value of the standard nozzle, determine the combination of the device nozzle and open the nozzle to measure the device nozzle. Fill in the results approved by the Ministry of Machinery and Electronics Industry on June 26, 1991 and implemented on July 1, 1992 one by one in Appendix A.
3.1.5 Start the vacuum pump.
JB/T5143-1991
3.1.6 Determine the following reference values in the test bench room: a. Atmospheric pressure gauge indication: p, (Pa)
b. Standard mercury thermometer indication: t, (℃) c. Thermometer indication: Dry bulb temperature indication T, (℃) Wet bulb temperature indication Tw (℃)
d. Standard mercury pressure gauge indication: pz (Pa) e. Temperature inside the sonic nozzle box: t (℃)
3.1.7 Calculate based on the measured data to obtain the standard nozzle flow rate value and the device nozzle flow rate value, and check whether they are within the allowable error. 3.18 Flow calculation
a. The flow calculation of the standard nozzle is based on formula (1): Ga=Kp,H
Wherein: G.
The flow of the standard nozzle, g/s;
The sum of the flow coefficients of a group of standard nozzles, g/(s:Pa); p—corrected atmospheric pressure value, Pa; calculated according to formula (2): pi=p:(9.80665
0.000163xt)
The acceleration of gravity at the calibration site, m/s2; F
Humidity coefficient, find out the relative humidity according to the dry-bulb and wet-bulb temperature table (Figure A1) and then find out the humidity coefficient on the relative humidity table (Figure A2)
b. The flow calculation of the device nozzle is based on formula (3): G,=K2(pi-P2)H||t t||Where: G,
Flow rate of the device nozzle, g/s;
-correction value of a standard mercury pressure gauge, Pa; calculated according to formula (4): p
p2=p2l9.80665
0.000163(120))
K,——the sum of the flow coefficients of a group of device nozzles, g/(sPa) c. Calculate the flow error o,:
d. The allowable value of the flow error is:
(0.5+0.02Xing
Where: M——maximum measurable value;
measured value.
3.1.9 According to the flow range specified in the technical agreement, draw the air flow allowable error range curve A3, and change the α in Appendix A to 2
JB/T 5143- 1991
Point is within the flow allowable error range curve to determine whether it is qualified or not. 3.2 Maximum suction negative pressure test
Seal the air inlet of the test bench, open the nozzle, start the vacuum pump, and after it stabilizes, observe the precision vacuum gauge in the front chamber of the nozzle box. The negative pressure value should not be less than 0.08MPa.
3.3 Fuel flow accuracy test
The fuel flow accuracy test is carried out in the following steps: 3.3.1 Prepare the fuel flow calibrator, discharge container and balance. 3.3.2 Refer to Figure 2 to connect the fuel outlet on the test bench dashboard and the inlet of the fuel flow calibrator. Fuel pressure gauge
Exhaust valve
Dashboard drain valve
Flowmeter
Dashboard
Fuel flow calibrator
Exhaust Passenger release device
Figure 2 Schematic diagram of fuel flow detection
3.3.3 Set the fuel pressure at 20~30kPa3.3.4 Connect the fuel flow tester and balance to the AC power supply according to the instructions and preheat for 15 minutes. 3.3.5 Use the fuel temperature control device to control the oil temperature to 23±2℃. 3.3.6 Open the exhaust valve to exhaust the air in the fuel pipe and the tester. 3.3.7 Test according to the national flow meter verification regulations and determine the flow accuracy. a. Glass rotor flowmeter is tested according to JJG257 standard. b. Gear flowmeter is tested according to JJG235 standard. 3.3.8 Flowmeter accuracy
This standard stipulates: The rotor flowmeter is not less than 2.5 level, and the gear flowmeter or other forms of flowmeter is not less than 0.5 level. 3.4 Fuel temperature control accuracy test
When the room temperature is within the range of 15~31℃, first control the fuel temperature at 23±2℃. After stabilization, use the carburetor product to do flow test for no less than 30min. Observe the oil temperature every 2min and keep records. The oil temperature changes by ±2℃. 3.5 Fuel pressure control test
3.5.1 Pressure supply test: Set the fuel pressure at a point within the range of 20~30kPa. After the pressure stabilizes, test the carburetor for no less than 20 working points. Observe the pressure gauge value at each point and keep records. The fluctuation is no more than 0.5kPa. 3.5.2 Gravity supply test: After the carburetor is clamped, adjust the gravity oil box to the height required by the product, and then test the carburetor at each test point for no less than three times. Observe that the fluctuation of the oil level in the oil box should not exceed 2mm. 3.6 Air system air tightness test
3.6.1 Air system rear cavity air tightness test Seal the air inlet of the test bench, close all nozzles, start the vacuum pump, when the vacuum reaches the maximum, turn off the vacuum pump, observe the vacuum gauge of the rear cavity of the nozzle box, the vacuum gauge drop value should not exceed 1.5kPa/min, at this time, there should be no vacuum in the front cavity of the spray box. 3.6.2 Air system front cavity air tightness test After the test in 3.6.1, open a nozzle with a larger flow rate in the nozzle box, start the vacuum pump, observe the vacuum gauge behind the throttle, when the vacuum reaches the maximum, turn off the nozzle. After stabilization, observe for 10 minutes, the vacuum drop value of the front cavity of the nozzle box should not exceed 0.14kPa/min. 3.7 Sonic condition test
Open all nozzles, start the vacuum pump, and after the pressure stabilizes, observe the vacuum gauge indications before and after the nozzle, and calculate the absolute pressure ratio under the critical state to satisfy formula (7): Absolute pressure after the nozzle
Absolute pressure before the nozzle
Note: This formula is only applicable to the calculation of Laval type nozzles. 3.8 Fuel flow repeatability measurement
3.8.1 Prepare according to the procedures of 3.3.1 to 3.3.6. ≤0.75
3.8.2 According to the selected flow meter total range, select no less than six points for measurement, measure each point no less than 10 times, record the weight G, pressure pr, temperature, time T, indication value x, etc. during each measurement and fill them in Appendix B, calculate the average value and standard error αfo3.8.3 The standard error should satisfy formula (8) or formula (9): When using a glass rotor flow meter,
<0.5%+0.05%
When using a gear flow meter or other forms of flow meter, <0.1%+0.025%
（g/s）
Wherein: x——measurement data of a certain time; n——total number of measurements;
M——full scale value.
(10）
Remarks:
Ball temperature
Sonic spray
Detector:
JB/T5143-1991
B/T 5143199
JB/T5143-1991
Dry bulb temperature\C
Figure A1 Relative humidity conversion chart
JB/T 5143 - 1991
Relative humidity coefficient chart
28°℃
JB/T 5143 - 1991
Xi Qiu Shuang
(s/）
JB/T5143-1991
Measurement No.
Calculation Result
Tester:
Additional Notes:
This standard was proposed and managed by the Tianjin Internal Combustion Engine Research Institute of the Ministry of Machinery and Electronics Industry. This standard was drafted by Changchun Aviation Machinery Equipment Company and the Tianjin Internal Combustion Engine Research Institute of the Ministry of Machinery and Electronics Industry. The main drafters of this standard are Tang Wentao, Lin Hui and Wang Heng. 9
People's Republic of China
Mechanical Industry Standard
Carburetor Integrated Flow Test Bench
Test Method
JB/T 5143 -1991
Published and issued by the China Academy of Mechanical Science
Printed by the China Academy of Mechanical Science
(No. 2 Shouti South Road, Beijing
Postal Code 100044)
Word Count 16,000
Format 880×1230
Print Sheet 3/4
First Edition in September 1991
First Printing in September 1991
Print Quantity 1-500
Price 1.20 Yuan
Mechanical Industry Standard Service Network: http://www.JB.ac.cn1661 - /
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