乙烯同向流扩散火焰的数值模拟和芳烃生成的动力学分析

Numerical Simulation of Coflow Diffusion Ethylene/Air Flame and Kinetic Analysis of Aromatic Hydrocarbon Formation

发展了一个包含芳烃子机理的乙烯燃烧详细反应动力学模型,利用Laminar SMOKE程序对文献乙烯同向流扩散火焰进行了数值模拟.结果表明,模型能够准确地预测乙烯扩散火焰中燃料的分解和芳烃的生成过程.生成速率分析显示,燃料的消耗主要是通过H提取反应生成乙烯基,以及单分子解离反应生成H2CC和氢气.火焰中芳烃的生成起始于由乙烯复合反应生成的炔丙基,炔丙基通过一系列反应生成苯和苯基,苯基的后续系列氢提取碳加成(HACA)路径则是萘这一最重要的双环芳烃的主要来源.

A detailed kinetic model of ethylene combustion with the formation submechanism of aromatic hydrocar- bons was developed, and numerical simulation of a previous coflow diffusion ethylene flame was performed with LaminarSMOKE code. The present model is able to reproduce fuel decomposition and formation of aromatic hydro- carbons in ethylene diffusion flame. Rate of production analysis reveals that ethylene is mainly consumed by H- abstraction reactions which produce vinyl radical and unimolecular decomposition reaction which produces H2CC and H2. Reactions from ethylene can produce propargyl radical, which is the major precursor of benzene and phenyl radi- cal in the coflow diffusion ethylene flame. The HACA reaction sequence from phenyl radical is the dominant forma- tion pathway of naphthalene, which is the most important bicyclic aromatic hydrocarbon.