DME简化反应模型及其在HCCI燃烧分析中的应用研究

提出了一个可应用于HCCI发动机工作过程研究的DME化学反应动力学简化模型,该模型由28种组分、38个基元反应组成,包括3个子模型,即低温反应和负温度系数区子模型、高温裂解和高温氧化子模型以及甲酸生成过程子模型.通过算例对比分析,该DME简化模型能正确揭示DME燃烧过程主要生成物组分的变化规律,能准确计算DME燃烧过程低温和高温阶段的放热特征时刻,其计算结果与详细机理计算结果吻合.相对于详细机理,简化模型节省了计算时间,为实现化学反应动力学与CFD多维模型耦合的燃烧计算提供了一个可行而有效的途径.

New reduced kinetic model for HCCI engine fuelled with dimethyl ether

This paper presents a new reduced chemical kinetic mechanism of DME for Homogeneous Charge Compression Ignition (HCCI) engine that consists of 28 species and 38 elementary reactions. The kinetic model for this reduced chemical kinetic mechanism includes low temperature and negative temperature coefficient region sub-model, pyrolysis and high temperature oxidation sub-model, as well as the formic acid formation sub-model. The simplified model conforms well with the thermodynamic model and can therefore be used to simulate the heat release characteristic time of low and high temperature stages. In comparison with the detailed model, this reduced one can save a lot of calculation time but its calculation results may well agree with those from the detailed one. This study shows that the proposed kinetic model can be coupled with CFD software to predict the combustion and exhaust emissions of HCCI engine operated with DME.