Combustion Characteristics Research On Ethanol Reforming Fuel Engine

One of the zero-dimensional combustion models is presented,by which the heat release rate is able to be calculated,while using the hydrogen-rich gaseous fuel as fuel on SI engine;The paper also proposes several formulas and methods on calculating the properties of the hydrogen-rich gaseous fuel,and the reactant and the combustion products.The computer program is developed,by which the analysis is performed on the features of the fuel and the reactant and the combustion products, and the heat release rate of the reforming ethanol-fuel engine.Compared with that of traditional I.C.engines,the key of the zero-dimensional combustion model of reforming ethanol-fuel engine is calculating the characteristics of the hydrogen-rich gaseous fuel and the reactant and the combustion products.The combustion model of the reforming ethanol-fuel engine includes the single-zone model and the AVL-Boost estimated model.According to a general expression of the reforming ethanol-fuel,by which the fuel compositions,and ethanol concentration,and the reforming efficiency are related with each other,and the composition concentration of reforming ethanol varies with the ethanol concentration,and the reforming efficiency can be calculated.The formulas is presented,by which the influences on the volumetric efficiency is able to be calculated while using the hydrogen-rich gaseous fuel,reforming ethanol as fuel on SI engines,or using partial reforming ethanol on diesel engines via the manifold. The paper also presents a method for calculating the mole of reforming ethanol's combustion products by the traditional method of chemical equilibrium.The computer program is developed,by which those can be done to calculate the heat release rate of the reforming ethanol-fuel engine using the single-zone model, and to calculate the compositions of reforming ethanol-fuel,and to determine the variety of the mole before and after ethanol fuel reforming,and before and after combustion,and to obtain several parameters of the reforming ethanol fuel such as LHV and stoichiometric air-fuel ratio,and MMW etc.. Based on the known reforming efficiency and the compositions of the fuel,The analysis of the heat release rate of the reforming ethanol-fuel engine shows that while using re-fuel,maximum heat release rate is higher,and the burning is faster,and the ignition delays,and the combustion duration is shorter than gasoline engine.The calculation shows that the combustion with reforming ethanol-fuel is closer to the isovolumic combustion,and the maximum heat release rate vary with ignition timing. With the increase of the excess air coefficientλ,maximum heat release rate and maximum cylinder temperature reduce,and combustion duration increases,with the decrease of the excess air coefficientλ,there is arapid combustion,and the heat release curve rises faster and steeper.The fuel characteristics analysis of the reforming ethanol-fuel engine shows that: when ethanol concentration keeps unchanged,the composition and LHV of the reforming ethanol fuel and the reactant's composition and the combustion product's composition vary with the ethanol concentration and reforming efficiency,and with the increase of the reforming efficiency,there is more decrease of the volumetric efficiency for reforming ethanol-fuel engines.