DME Engine Electronic Control Of Fuel Supply System

With the progress of human being's socity and the rapid economic development,human being have created a lot of material wealth and spiritual civilization,but also have brought the increasingly tense energy crisis and enviormental deterioration ,which have seriously affected the sustainable development of human being.At the same time, the automobile industry is one of the largest industry of consuming energy and the main source of enviormental pollution. In response to the challenge of energe crisis and environmental pollution,human being have actively researched diesel engine technology,and have made lots of results:high pressure common rail injection technology,emission control technology and so on .At the same time human being have been seeking for the other alternative fuels.The studies show that,DME with high cetane number and excellent combustion properies can significantly reduce the emissions,especially the NOX and soot, is an ideal alternative fuel for diesel engine.As the common rail system is not very sensitive to the high flexibility of DME molecular ,the conventional plunger and barrel assembly is very difficult to measure the DME injection mass by piston;The injection rate and injection pressure of common rail injection system can varying flexibility according to the engine speed and load ,flexible control of injection of the DME can achieve the best operating resultings.So the most suitable DME fuel supply system is the common rail fuel system.Combination of the two,the DME common rail engine have the advantages of the excellent combustion of the DME and the accurate ,flexible control of the common rail system.At first,the research actuality in domestic and abroad of DME and common rail fuel injection system was introduced .The specific work has been done in this paper as the following:⑴Based on the thermophysical properties of liquid, the thermophysical properties of both DME liqueid and its vapor were worked out .The engine model was established fueled with DME according to the parameters of ZS1100.The simulation's data was comparaed with the expermental's data.The result showed that the coefficient in GT and the engine model were correct and reasonable.⑵On analysing the structure and working principles of common rail fuel injection system,its model was established in GT-FUEL.The common rail fuel injection model and the engine model were coupled in GT-FLOW.The influence of the main parameters of injector on injection rate was investgated .and then analysed the influence of corresponding injection rate on heat release rate,engine performance. ⑶Based on simulation model,The author simulated and analysised the influence of injection timing and rail pressure on injection rate,heat release rate ,and engine perfoemance.⑷The control strategy was set up for DME common rail injection system.The control unit was established in SIMULINK,and then the control strategy was simulated.The result showed that the control strategy was correct and reasonble.