Study On Matching And Calibration Of Electronically Controlled Gasoline/CNG Flexible Fuel Engine

Under the dual pressure of petroleum crisis and environmental pollution, clean energy automobiles with natural gas as fuel attract more and more attention of people. With current technology of natural gas engine and the development situation of natural gas stations, electronically controlled Gasoline/CNG flexible fuel vehicles have been used widely. In order to make Gasoline/CNG flexible fuel engine obtain better power performance, lower fuel consumption and lower emission, and maintain a good stability, it is necessary to match a natural gas system and an engine, especially to calibrate the control parameters.In this paper, based on test bench of 4RB2 electronically controlled gasoline engine calibration,with the help of electronically controlled gasoline engine calibration achievements, an advanced RSI system is combined into the natural gas system.Compared to the traditional mixer supply system, the RSI system makes the control process more advanced and responds faster, and its operation is simpler. Furthermore, since the flame propagation speed of natural gas-air mixture is low, and octane number of natural gas is high, spark advance could be properly increased to improve engine power performance, so a spark advance implement is developed in the paper. By using visualization calibration software, the Mapping value is amended on real-time online; the matching calibration is completed for the natural gas system of electronically controlled Gasoline/CNG flexible fuel engine.Results of matching calibration are as follows. The outlet pressure of regulator is 150kPa. The maximum torque of CNG is close to 87% of that of gasoline at full load. HC emission and CO emission are reduced significantly, and NOx emission is slightly low. The results come to expected target.