醇醚双燃料HCCI燃烧机理研究

HCCI Mechanism of Methanol/DME Dual Fuel

采用敏感度分析法对二甲醚(CH3OCH3)、甲醇(CH3OH)详细机理进行简化,构建可用于均质压缩燃烧(HCCI)过程的二甲醚-甲醇简化动力学模型,包括38个物种和99个基元反应,特别添加了非常规排放物甲醛(CH2O)、甲酸(HCO2H)和甲酸甲酯(CH3OCHO)的生成子模型。应用该简化机理模型对甲醇HCCI发动机的燃烧与排放特性进行的算例分析表明,简化机理模型在燃烧放热特征时刻、燃烧累积热效应以及发动机缸内温度和压力曲线的预测值均与详细模型的计算值较为吻合,计算时间缩短,为提高化学反应流多维数值模拟的计算效率奠定了基础。

The detail mechanism of dimethyl ether （CH3OCHO） and methanol （CH3OH） was simplified by the method of sensitivity analysis and the reduced chemical kinetic model of methanol/DME HCCI was established .The model included 38 speciesand99elementreactionsandformaldehyde（CH2O）,formicacid（HCO2H）andmethylformateformation（CH3OCHO） sub-models were specially added .The combustion and emission characteristics of methanol HCCI engine were analyzed with the model .The results show that the reduced model agrees well with the detailed one in the aspects of heat release timing ,cumula-tive thermal effect ,in-cylinder temperature and pressure curve and has shorter calculation time ,which lays the foundation for improving the multi-dimension numerical simulation of chemical reaction flow .