Combustion Model Of LPG Automobiles And Analysis Of Emission Rules

The problem of energy shortage and environment pollution become more serious and the vehicle emission regulations of city become stricter in recent years, which compel us to develop clean substitute fuel vehicle. As one of substitute fuel vehicle, Gasoline/LPG (Liquefied Petroleum Gas) dual-fuel vehicle has been widely used because of its unique advantages of emission reduction and environment protection, as well as good economy.On the base of analysis of the physical and chemical properties of LPG, a quasi-dimension combustion model of spark ignition LPG engine is set up in this dissertation, which is composed of dual-zone thermodynamics model, flame promulgating model, geometry calculation model and so on. The parameters in cylinder of combustion process such as temperature and pressure can be estimated by the model.With the help of this model, the influence of engines capability by some parameters such as compression ratio,coefficient of excess air and ignition timing can be estimated, and the influence factor was analyzed in this paper.Based on the quasi-dimension combustion model, the emission model is set up in this dissertation. The NO emissions in different conditions of LPG engine can be simulated and calculated by the model. The calculated results show that the NO emissions are larger influenced by ignition timing and less influenced by compression ratio, finally, choosing a right coefficient of excess air will have great effect to reduce NO emissions.