CN101464173B - Test method for liquid pressure fuel tester system - Google Patents

Abstract

A testing system of a liquid pressurized fuel tester adopts two fuel consumption meters for measurement, and is characterized in that a flowmeter is chosen to measure the amount of incoming oil in an oil incoming channel; a returning oil testing instrument which measures the amount of fuel consumption by the constant volume timing method is used for measuring the amount of oil in the oil returning channel of an engine; the flowmeter for measuring the oil amount in the oil incoming channel is a mass flowmeter; the measurement of the oil amount in the oil returning channel is completed by the liquid pressurized fuel tester; a singlechip is used for information acquisition, processing, calculation and displaying as well as examination and correction of abnormal condition; and finally a computer is used for outputting and printing the fuel consumption of the engine.

Description

Test method for liquid pressure fuel tester system

technical field

The invention relates to a liquid pressure fuel tester system testing method, which belongs to the technical field of fluid measurement, in particular to the technical field of fuel consumption measurement in engine bench tests.

Background technique

At present, in the engine bench test, the consumption of liquid pressure fuel is generally measured by the gravimetric diagram shown in Figure 1 and the flow method diagram shown in Figure 2.

The gravimetric method is to use a precision electronic scale to measure the weight lost by the fuel tank per unit time, so as to calculate the fuel consumption of the engine per unit time. The test device of this method is a precision electronic scale. Take Huazhong University of Science and Technology as a representative to adopt this method (Yusheng Zhang, Chunlan Mo, Huiya Zhang et.A Study on Combustion and Emission Characteristics of Small DI DieselEngine Fuelled with Dimethyl Ether The 7th Asia-Pacific International Symposium on Combustion and Energy, 1 17/12/2004, paper No. 235, Hong Kong)

The disadvantages of gravimetric measurement are: in order to make the cumulative consumption conform to the range and accuracy of the electronic scale, the engine is required to maintain a stable working condition for a long time. This method has low measurement accuracy and cannot measure the dynamic instantaneous fuel consumption of the engine.

The flow method is to use a single flow meter to measure the flow of liquid pressure fuel through the flow meter per unit time, so as to calculate the fuel consumption of the engine per unit time. The test device of this method is the auxiliary fuel tank and the mass flow meter. precision flowmeter.

Xi'an Jiaotong University (Wang Hewu, Zhou Longbao, Huang Zuohua, etc. Experimental research on direct injection diesel engine fueled with dimethyl ether "Journal of Internal Combustion Engines" 1999/17/03 P 241-246.) and ToCeiL engine instantaneous fuel consumption developed by Shanghai Tongyuan Environmental Protection Technology Co., Ltd. Instrument, Chengdu Chengbang Company's ET2700 EFI engine oil return processor, Shandong Longkou AM400 flow sensor and other units all adopt this method for testing.

The disadvantages of flow method measurement are: the test basis of this test method is based on the premise of "constant amount of fuel in the auxiliary fuel tank". The internal fuel density is also non-constant, in which case it is difficult to measure the change in fuel mass in the drop tank or to keep the fuel mass constant, so the measurement is inaccurate.

Contents of the invention

The purpose of the present invention is to overcome the above deficiencies and provide a liquid pressure fuel tester system that solves the problem of gas-liquid two-phase mixed fuel testing in the oil return circuit and can accurately measure the cumulative fuel consumption and dynamic instantaneous fuel consumption Test Methods.

The technical solution of the present invention is: the test method of the liquid pressure fuel tester system is measured by a double oil consumption meter, which is characterized in that in the oil inlet circuit, a flow meter is used to measure the amount of oil inlet, and on the oil return circuit, a The oil return tester for measuring fuel consumption by a constant volume timing method is used to measure the oil quantity of the engine return oil circuit; The measurement is completed by the oil return tester—that is, the time when the liquid is filled with the constant volume pressure vessel is measured, and the fuel consumption measured by the oil inlet flowmeter is subtracted at the same time to calculate the fuel consumption of the engine. The mathematical equation is:

g＝g _j -g _h

In the formula, g——fuel consumption (g);

g _j ——inlet oil quantity (g); g _h ——return oil quantity (g);

Among them, g _j and g _h are:

g _h =V _D ×ρ

V _D ——constant volume ρ——liquid density

G _k ——accumulated mass of the oil inlet flowmeter within time t

——进油流量在流量计中计量的时间

——The time when the oil inlet flow is measured in the flowmeter

The liquid pressure fuel tester system test method is composed of a position signal sensor, an input circuit, a single-chip controller, a drive circuit, a solenoid valve and an LED solenoid valve display to automatically complete the detection system. In this system, the engine oil flow rate is determined by Mass flowmeter measurement, the real-time measurement value is transformed into 4 ~ 20mA analog signal output, which is conditioned by the input circuit and collected by the single-chip microcomputer; the engine return oil flows into the high-pressure resistant glass container through the solenoid valve control circuit, and through the cooperation of the single-chip microcomputer, the fixed The time to accommodate the oil return, with the known fuel density, calculate the quality of the oil return per unit time, and also calculate the quality of the oil supply per unit time, so as to calculate the fuel consumption of the engine.

The liquid pressure fuel tester uses a transparent glass tube as a constant volume container, and a liquid level detection device is composed of a light-emitting diode and a photosensitive diode to send an interruption signal; five solenoid valves are used as the executive mechanism to realize the working process, and at the same time, the detection of liquid The pressure and temperature of the liquid are corrected for the density of the liquid.

The oil return tester automatically completes measurement, calculation, display and abnormal state inspection and correction.

The beneficial effects of the present invention are:

The test method of the liquid pressure fuel tester system can independently test the fuel consumption of engines with oil return devices such as electronic injection engines, diesel engines, and liquid pressure fuel engines. It can also be compatible with the ET2000 engine measurement and control system to test the engine's power, economy and other performances. The test data and test curve analysis are real and effective. During the test, it is safe and reliable, easy to operate, sensitive in response, small in data fluctuation, and the accuracy reaches 0.3 level. It can be used for remote communication control measurement.

Description of drawings

The present invention will be further described in conjunction with accompanying drawing

Fig. 1 is the existing gravimetric test schematic diagram;

Fig. 2 is the schematic diagram of existing flow method test;

Fig. 3 is the principle diagram of the static calibration test system of the liquid pressure fuel tester of the present invention

Fig. 4 is a schematic diagram of the test system of the liquid pressure fuel tester of the present invention;

Fig. 5 is a functional block diagram of the test system of the liquid pressure fuel tester of the present invention

Fig. 6 is a diagram of the working state of the test system of the liquid pressure fuel tester of the present invention

Fig. 7 is 2 diagrams of the working state of the test system of the liquid pressure fuel tester of the present invention

Fig. 8 is 3 diagrams of the working state of the test system of the liquid pressure fuel tester of the present invention

Fig. 9 is 4 diagrams of the working state of the test system of the liquid pressure fuel tester of the present invention

Fig. 10 is the test curve 1 figure of the ZS1100 diesel engine that the liquid pressure fuel tester of the present invention records

Fig. 11 is the test curve 2 figure of the ZS1100 diesel engine that the liquid pressure fuel tester of the present invention records

Fig. 12 is a test application diagram of the test system of the liquid pressure fuel tester of the present invention on the engine bench

Parts, parts and numbers in the figure:

1- Fuel tank 2- Mass flow meter 3- Liquid pressure fuel tester 4- Graduated cylinder A 5- Graduated cylinder B

6-Valve x1 7-Valve x2 8-Valve x3 9-Engine 10-Oil inlet solenoid valve D1

11-Through solenoid valve D2 12-Oil outlet solenoid valve D3 13-Intake solenoid valve D4 14-Exhaust solenoid D5

15-Temperature sensor 16-Pressure sensor 17-Return oil flow test tank 18-Liquid level sensor

19-High pressure nitrogen cylinder 20-DME fuel tank 21-Fuel flow meter 22-DME transfer pump

23-pressure regulator 24-accumulator 25-high pressure pump 26-nozzle

Detailed ways

Connect with pipelines and cables according to the circuit diagram shown in Figure 4.

Design of Liquid Pressure Fuel Tester

A. The functional block diagram of the liquid pressure fuel tester system is shown in Figure 5:

In the system, the engine oil inlet flow rate is measured by the mass flow meter, and the real-time measured value is converted into a 4-20mA analog signal output, which is conditioned by the input circuit and collected by the single-chip microcomputer; the engine oil return flows into the high-pressure resistant glass container through the solenoid valve control circuit , through the cooperation of single-chip microcomputer, detect the time of constant volume oil return, with the help of known fuel density, calculate the quality of oil return per unit time, and also calculate the quality of oil supply per unit time, so as to calculate the engine The fuel consumption; the whole system can automatically complete the measurement, calculation, display and abnormal state inspection, and can carry out remote control measurement.

B. The working process design of each solenoid valve in the liquid pressure fuel tester

The liquid pressure fuel tester is used to measure the oil return oil quantity of the liquid pressure fuel engine, and its working status is divided into 4 types:

a) The engine is running normally and no oil measurement has been performed. At this time, oil inlet 10-oil inlet solenoid valve D1 is closed, 11-through solenoid valve D2 is opened, 12-oil outlet solenoid valve D3 is closed, and the oil return route of the engine is shown in Figure 6.

b) Start measuring engine oil consumption. At this time, 10-oil inlet solenoid valve D1 is open, 11-through solenoid valve D2, 12-oil outlet solenoid valve D3, 13-intake solenoid valve D4, 14-exhaust solenoid D5 is closed, when the lower limit liquid level detection is true , start counting, and accumulate the oil intake at the same time. The engine oil return route is shown in Figure 7.

c) After the test is completed, drain the liquid. When the upper limit liquid level detection is true, stop timing and close 10-oil inlet solenoid valve D1, open 11-straight-through solenoid valve D2, 12-oil outlet solenoid valve D3, 13-intake solenoid valve D4, and calculate and display at the same time The results and upload to the host computer. The engine oil return route is shown in Figure 8.

d) Remove nitrogen and enter standby mode. When the detection of the lower limit liquid level is negative, close 12-oil outlet solenoid valve D3, 13-intake solenoid valve D4, open 14-exhaust solenoid D5, and perform natural emptying. When the pressure is lower than the set value, close 14-Exhaust electromagnetic D5, enter the standby state. The oil return route of the engine is shown in Figure 9.

C. Structural design of liquid pressure fuel tester

The liquid pressure fuel tester uses a transparent glass tube as a constant volume container in structure; a liquid level detection device is composed of a light-emitting diode and a photosensitive diode, and sends out an interruption signal; five solenoid valves are used as an actuator to realize the working process. At the same time, the pressure and temperature of the liquid are detected, and the density of the liquid is corrected.

Practical Application Test of Liquid Pressure Fuel Tester System Test Method

The test system of the liquid pressure fuel tester is calibrated by using the static calibration method. Firstly, the system is calibrated after connecting the pipelines according to the circuit diagram shown in Figure 3. The calibration data are shown in Table 1.

Table 1 Static calibration data record table of liquid pressure fuel tester

Calibration times 1 2 3 4 5 6 Measurement time t(s) 25.75 26.29 26.95 25.30 25.30 26.93 Volume of liquid in measuring cylinder V _h (ml) 105 110 112 115 110 108 Actual liquid consumption B _s (kg/h) 14.68 15.06 14.96 16.36 15.65 14.44 Measurement shows consumption B _x (kg/h) 14.72 15.10 15.00 16.40 15.69 14.47 Relative error δ(%) 0.28 0.25 0.26 0.22 0.24 0.22

It can be concluded from the above data that the accuracy of the liquid pressure fuel tester can reach level 0.3.

The test method of the liquid pressure fuel tester system can be used alone to test the fuel consumption of engines with oil return devices such as electric injection engines, diesel engines, and liquid pressure fuel engines. It can also be compatible with the ET2000 engine measurement and control system to test the engine's power, economy and other performances.

Using the test method of the liquid pressure fuel tester system, in cooperation with the ET2000 engine measurement and control system, the economical efficiency of the ZS1100 diesel engine fueled with dimethyl ether has been experimentally studied on the engine bench. The test data are shown in Table 2, and the test curves are shown in Figure 10 and Figure 11.

According to the test data and test curve analysis, the test data is true and effective, and the trend of the test curve is in line with the characteristics of diesel engines.

The system test method of the liquid pressure fuel tester is safe and reliable, easy to operate, sensitive in response and small in data fluctuation during the test process.

Table 2 The test data table of ZS1100 diesel engine measured by the fuel consumption measurement system of dimethyl ether engine

It can be seen from the above test data and usage conditions that the measurement accuracy of the test method of the liquid pressure fuel tester system has reached 0.3 level, and the whole system is safe, reliable and easy to operate. The trend of the test curve conforms to the characteristics of the diesel engine.

Claims (3)

1. liquid pressure fuel tester test macro, adopt two fuel consumption meters to measure, it is characterized in that in the oil-feed oil circuit, select for use flowmeter to carry out the measurement of oil-feed oil mass, on oil return circuit, the oil return tester of being measured Fuel Consumption by a kind of constant volume chronometry carries out the measurement of engine oil return circuit oil mass; The flowmeter of measuring oil mass in the oil-feed oil circuit is a mass flowmeter, measuring oil mass in the oil return circuit is to be finished by the measurement of oil return tester---promptly measure the time that liquid is full of the constant volume pressure vessel, subtract each other the Fuel Consumption that comes calculation engine with the oil-feed flowmeter with the Fuel Consumption of measuring in the time, its mathematical equation is:

g＝g _j-g _h

G in the formula---Fuel Consumption (g);

g _j---oil-feed oil mass (g); g _h---oil return oil mass (g);

Wherein, g _j, g _hFor:

g _h＝V _D×ρ

V _D---constant volume volume ρ---fluid density

G _k---the accumulative total quality of oil-feed flowmeter in time t

---the time that the oil-feed flow measures in flowmeter.

2. a kind of liquid pressure fuel tester test macro as claimed in claim 1, it is characterized in that liquid pressure fuel tester adopts transparent glass tube as the constant volume container, constitute liquid level detection device by light emitting diode and photodiode, send look-at-me; As the topworks that realizes workflow, simultaneously, the pressure and temperature of tracer liquid is revised fluid density by five solenoid valves.

3. a kind of liquid pressure fuel tester test macro as claimed in claim 1 is characterized in that the liquid pressure fuel tester test macro finishes measurement, calculating, demonstration and abnormality inspection correction automatically.

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