基于组分浓度的LNG-柴油燃料反应机理简化  

Reduction of chemical kinetic mechanism for combustion of natural gas-diesel fuel with concentration of species as target parameter

作　　者：李格升[1] 田芬 梁俊杰[1] 张尊华[1] LI Gesheng;TIAN Fen;LIANG Junjie;ZHANG Zunhua(School of Energy and Power Engineering,Wuhan University of Technology,Wuhan 430063,China)

机构地区：[1]武汉理工大学能源与动力工程学院,湖北武汉430063

出　　处：《华中科技大学学报（自然科学版）》2021年第10期53-59,共7页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(51779199,51809204)。

摘　　要：以甲烷-正庚烷-异辛烷-环己烷-甲苯混合物作为LNG(液化天然气)-柴油模型燃料,构建了包含1 425种组分和5 597个基元反应的LNG-柴油模型燃料详细燃烧反应机理.以重要组分摩尔分数为目标参数,通过基于误差传递直接关系图法对该详细机理进行了简化,分析了简化阈值与机理规模的关系,结合反应路径研究了机理简化的规律.结果表明:随着简化阈值增大,机理规模逐渐减小,但减小的速度逐渐降低,当阈值增大至0.8时,简化机理规模基本恒定.结合简化阈值与误差,确定合理的简化机理包含208种组分和1 087个基元反应,该机理可准确预测模型燃料的着火延时与层流燃烧速度.简化机理保留了H2/CO/C1子机理、C2-C3半详细机理和C4-C8骨架机理,去除了约85%冗余组分和81%的基元反应.The methane/n-heptane/iso-octane/cyclohexane/toluene mixture was selected as the surrogate model of liquefied natural gas-diesel dual fuel,and a detailed reaction mechanism consisting of 1 425 species and 5 597 reactions was established.A reduced reaction mechanism of the surrogate model of liquefied natural gas-diesel dual fuel was developed with species concentration as target parameter, based on the directed relation graph with error propagation method. The relationship between threshold and mechanism scale was analyzed, and the law of mechanism reduction was studied with reaction path analysis. Results show that with increase of the threshold, the scale of reduced mechanism decreases, while decreasing rate decreases gradually. When the threshold increases to 0.8, the scale of reduced mechanism is basically constant. Considering both of threshold and error, the determined reduced mechanism consists of 208 species and 1 087 reactions,which is capable of accurately predicting ignition delay times and laminar burning velocities of the surrogate fuel.The reaction path analysis shows that the reduced mechanism includes the core mechanism of H2/CO/C1, the semi-detailed mechanism of C2-C3 and the skeleton mechanism of C4-C8, with about 85%reduction of species and 81% reduction of reaction.

关 键 词：LNG-柴油模型燃料 机理简化 组分摩尔分数 基于误差传递直接关系图法 阈值 

分 类 号：TK412[动力工程及工程热物理—动力机械及工程]