Research on Diesel Engine Combustion Mechanism and Simulation of Engine In-cylinder Combustion Process
Simulating the combustion process in diesel engine and studying the fuel combustion and pollutant formation mechanism are the fundamental approaches to improve the air environment and meet the emission regulations. This paper set n-heptane as an alternative fuel to diesel engine and calculated the chemical kinetics combustion process of n-heptane inside cylinder. The results showed that HO2 and OH are the main radicals that participate the dehydrogenation reaction of n-heptane, HO2 mainly comes from the two initial reactions of n-heptane, OH mainly comes from the pyrolysis reaction of H2O2, C7H15-1 and C7H15 are the key dehydrogenation reaction products, CH2O is the key aldehyde product, CH3 and C2H5 are the main products of high temperature pyrolysis reaction, in the high temperature phase, the generation of CO is mainly from the reaction of CH2O, the generation of CO2 is the result of reaction between CO and OH . Based on the calculation of chemical kinetics, by temperature sensitivity analysis, composition and reaction rate analysis, a reduced combustion model of n-heptane was got in the paper, the reduced model contained 43 kinds of components and 63 elementary reactions, calculation results showed that it gave predictions similar to detailed model in the ignition timing, temperature and pressure in-cylinder, the distribution of intermediate products and combustion products. Finally, based on the reduced model, the paper built a new combustion and emission model of diesel engine, the combustion process of a special diesel engine was simulated and the variation of parameters such as turbulent kinetic energy, fuel concentration, temperature in-cylinder and concentrations of the main intermediate products and NO were obtained. Key words: Diesel engine; n-heptane; Chemical kinetics; Reduced model; NO.
Song Zhou Cailing Li Peng Zhou Yuanqing Zhu
Harbin Engineering University,P.R.China
国际会议
上海
英文
1-7
2013-05-13（万方平台首次上网日期，不代表论文的发表时间）