Study On Combustion Characteristics Of Gasoline Blended With Dimethyl Ether

With the continuous improvement of production,people's quality of life is improving,and the number of cars is increasing rapidly,which cause enormous pressure on environment and energy which has been very serious.In order to alleviate these problems,people have made unremitting efforts to explore new technologies to reduce energy consumption and emissions,as well as to find new energy sources.From the point of view of new energy and alternative fuels,this paper selected gasoline blended with DME as a traditional fuel for ignition engine to investigate its combustion characteristics.Firstly,this paper discussed the characteristics of gasoline blended with DME as an alternative fuel according to the physicochemical properties of DME.Then the experimentation on combustion was carried out in a constant volume combustion bomb.Finally,AVL Fire software is used to simulate the expanded boundary conditions.The boundaries are chosen according to the actual working conditions,the experimental equipment and the physical and chemical properties of DME and gasoline.They are temperature: 150??180? and 210?,pressure: 0.8MPa?1.0MPa and 1.2MPa,the excess air coefficient: 0.8?1.0?1.2 and 1.4,and the mass fraction of DME: 0%?5%?10%?15% and 20%.Experimental results show that when DME is added into the gasoline,the combustion delay period is shortened,the combustion speed is accelerated,and the maximum combustion pressure decreases slightly;The effect of initial temperature and pressure on the combustion speed is similar,it is accelerated with the increase of initial temperature and pressure,the difference is that the maximum combustion pressure decreased with the initial temperature increased,but increased with the initial pressure increased;The combustion speed is changed with the excess air coefficient,the combustion speed is fastest under the theoretical air fuel ratio.Finally,AVL Fire is used to simulate the combustion of the fuel in the combustion bomb.The simulation results of the combustion duration and the maximum combustion pressure under different boundary conditions are compared and analyzed.The simulation results and the experimental data show the same change trend.