Engine Gas Nozzle Test Bench Development

In response to the two major global problems of oil crisis and air pollution, the automobile industryare proceeding an in-depth research on gas fuel engine, especially on compressed natural gas engine. Thispaper develops a gas nozzle engine test bench, the main purpose of which is to test nozzle characteristicsof gas fuel engine. To be specific, the electronic control unit of the test bench is developed based onInfineon XC2734X microcontroller, the gas measurement equipment is designed according to theprinciples of drain gas collection method. And besides, the Lab view software is used to develop PCsoftware for real-time monitoring the test bench and it can communicate with the ECU through CANprotocol. At the end of this paper, the whole test bench is built and used to test a specific model of gasnozzle for the relevant working characters. And the results show the test bench is functioning well andachieve the development goals. The main specific work of this paper is described below:1. Analyzed the main existing problems of engine gas injection system, proposed develop goals andfunctional requirements of the gas nozzle test bench. Based on the structure of gas fuel engine supplysystem, this paper proposed the overall design of the test bench, including the structure and principlesdesign of gas volume measurement equipment, the hardware and software design of electronic controlsystem. The former respect is based on drain gas collection method to design the structure and workingprinciple of gas measuring equipment, and the selection of microcontroller is based on the degree ofcomplexity of the control algorithm and functional and quantitative requirement of microcontrollerperipherals, and after comparison, Infineon XC2734X is eventually selected as the core microcontroller ofelectronic control unit.2. With rich on-chip peripheral resources of Infineon XC2734X, designed the hardware circuit ofelectronic control unit. Including CAN communication circuit, JTAG debug interface circuit, signalconditioning circuit for collecting pressure sensor signal and low-side driver circuit used for nozzledriving. And complete electronic control unit PCB design, welding and debugging, to meet the functionalrequirements. 3. Completed developing MCU underlying software program of the electronic control unit. Aftergenerating the system initialization functions and basic function library using microcontrollerinitialization configuration tool Dave software, completed complying, debugging and downloading theMCU programs in C language compiler environment provided by TASKING software.4. Used Labview to complete the design of PC software, including test monitoring, communicationsettings, test control, on-line parameter calibration, data processing and other functions.5. Combined with existing laboratory conditions and equipment, this paper built the entire test bench,and tested a specific model of the four-cylinder common rail domestic gas nozzle with its flowcharacteristics, rail pressure performance and inconsistencies performance. The test results proved that thetest bench can function well to test main characteristics of the gas nozzle. The test data were analyzed toobtain the basic characteristics curses of this model of nozzle and met the development goals.