生物柴油替代物燃烧反应机理的简化构建

Development of Reduced Combustion Reaction Mechanism of Biodiesel Surrogates

基于路径通量分析以及同分异构体整合对一个生物柴油的复杂燃烧反应机理(3299组分和10806个反应)进行简化,得到了一个生物柴油简化燃烧机理,该机理包含164个组分和695个反应.路径通量分析同时考虑了组分间的直接性以及经一个中间组分的间接相关性,同分异构体整合进一步将具有相同的摩尔质量和官能团以及相似输运性质的同分异构体及其反应整合进入同一个集总组分及相应的反应.所得简化机理被用于计算不同条件下封闭式均质反应器内自燃的着火延迟以及完美搅拌反应器内的燃烧,结果表明所得简化机理能够保留原始复杂机理的关键反应特性.通过三维数值模拟生物柴油在柴油机缸内工作条件下喷雾燃烧,证实基于该简化机理的燃烧模型能够较为准确地模拟生物柴油的喷雾燃烧过程.

Based on path flux analysis(PFA)and isomer lumping,a complex reaction mechanism of biodiesel surrogates with 3299 species and 10806 elementary reactions was reduced into one with 164 species and 695 elementary reactions.Both the species directly related to the target species and those indirectly related to the target species through an intermediate species are considered in the path flux analysis.The isomers with the same molecular weight,functional groups and similar transport properties are further integrated into a lumped species and corresponding reactions by isomers lumping.The reduced mechanism was used to calculate the ignition delay in a closed homogeneous reactor and the extinction curve in a perfectly stirred reactor under different conditions.The results show that the reduced mechanism can retain the key reaction characteristics of the original complex mechanism.The three-dimensional numerical simulation of biodiesel spray combustion was carried out under the working conditions of diesel engine.The results confirm that the combustion model based on the reduced mechanism can accurately simulate the spray combustion process of biodiesel.