Developemtn Of Control Unit For A Three-Cylinder PFI Gasoline Engine And Experimental Study On Hydrogen-Added And Oxygen-Enriched Combustion

With the development of Chinese economy,the living standards of people have been improved greatly and the car ownership is growing year after year.These situations,on one hand,have contributed to the development of automotive industry,on the other hand,have brought us more and more severe problems of environment and energy.Currently,traditional cars are dominant in the car market,thus,the development of energy-saving and environment-friendly technologies of engine is significant.To reach goals of development of more energy-saving and environment-friendly engine,advanced electronic control unit(ECU)of engine is required.Besides,based on the ECU,improving combustion conditions of traditional engine,such as hydrogen-added combustion and oxygen-enriched combustion,have attracted more and more attentions from the industry.In this context,basic electronic control unit of a gasoline engine was developed and then experimental investigation on the effect of hydrogen-added and oxygen-enriched on performance of it was carried out,which can lay a foundation for the engineering applications of technologies of hydrogen-added and oxygen-enriched combustion of the engine.Specifically,the JL3G10 type gasoline engine of China Geely Group was chosen to be the target engine.The operating principles and electronic control system were studied,firstly.And then,basic control strategies of intake,injection and ignition were designed to make sure the engine can start successfully.Based on designed control strategies,basic control unit of the engine was developed with the help of MotoTron platform.Lastly,the test bench of engine was set up and starting test was conducted to verify designed control strategies.Besides,intake system of the engine was modified to study effects of oxygen-enriched combustion,hydrogen-added combustion,simultaneous hydrogen-added and oxygen-enriched combus-tion on performance of the engine through test results.Test results showed that:(1)In the starting test,intake control,injection control and ignition control match very well and the engine can start successfully.And,in idling status,the control effect of engine speed and air-fuel rate is ideal,which verified designed control strategies of intake,injection and ignition.(2)Under the same operating status and air-fuel rate,engine power increased substantially,HC and CO emissions decreased,NO_X emission increased with oxygen-enriched intake.When the volume fraction of oxygen varied from 21%to 25%,the engine power increased by 20.7%,NO_X emission increased by 149.6%.(3)With the same experimental conditions,the engine power had a slight decline,HC and CO emissions decreased greatly,NO_X emission increased,when the volume fraction of hydrogen-added increased.(4)Lastly,with the same experimental conditions,the engine power improved,NO_X emission increased with simultaneous hydrogen-added and oxygen-enriched intake.NO_X emission increased by 41.9%,when the volume fraction of the hydrogen-added and oxygen-enriched increased from 0 to 5.06%.Besides,in this situation,HC and CO emissions decreased and the effect was similar to the case of hydrogen-added combustion.Thus,engine with mixture of hydrogen and oxygen can obtain relatively balanced performance.