Study On Experiment And Simulation Of Low-Pressure Common Rail Injection Process For Dimethyl Ether Engine

With the rapid development of automobile industry,the producing and living conditions of all the people in the word have been improved gradually. At the same time, the pressures of energy shortage and environmental protection have been continuously increasing. Automobile power technology was being developed for the objects of lower pollution, lower fuel exhaustion and high power per weight, and the exploitation of clean fuels also is an important direction of it.As its clean and efficient combustion performance, the mature production technique and some similarity characteristics with diesel fuel, DME (Dimethyl Ether) becomes a potential alternative fuel. There are still many problems that be applied to diesel engines because of its special characteristics. The design of DME injection system is the most important aspect in all of problems.Based on the extensive literatures reading, some interrelated problems such as the basic characteristics of DME, the main technology in DME injection system and the significance of studying on low-pressure common rail injection system are summarized in this paper. The experiment and simulation study of the injection process based on low-pressure common rail injection system have also been done.In this paper, the common rail injection system is reasonably simplified. Substitution models of pump, common rail and electromagnetic valve are given. The simulation model of the injection process in Matlab/Simulink is built according to mathematical equation about flow conservation per unit time and couple parts motion. With this model, the injection process is researched and the curves of the needle lift are obtained. The experiment of injection process is also done based on oil pump experimental workbench. From these data, its injection performance is synthetically investigated. The experiment and simulation results demonstrate that the low-pressure common rail injection system effectively solves the problems applying of DME to diesel engine, it meets the demand of basic injection characteristics of a diesel engine, and the system is reliable.