乙烷预混火焰多环芳烃生成动力学模拟

随着环保标准要求的不断提高，燃烧过程中生成的多环芳烃（PAHs）越来越受到人们的关注。在通过对PAHs气相反应模型分析的基础上，运用详细的化学反应动力学机理，计算了常压下乙烷层流火焰中多环芳烃的生成浓度，计算预测值同实验值吻合得比较好。同时，运用敏感性分析的方法，找出了形成苯的最主要的反应，发现影响苯生成的反应在距出口约0．15cm的地方影响最明显，之后又逐渐平缓。通过不同燃烧当量比的敏感性分析比较发现，影响苯生成的最主要基元反应没有发生变化，但每个反应所起到的作用发生了明显的变化，表现为原来促成苯生成的基元反应随着燃烧当量比的增加，促成苯生成的作用在减弱，原来抑制苯生成的基元反应，其抑制作用进一步增强。通过对影响A1～A4生成最主要反应的净产率比较发现，反应净产率变化最大的地方基本集中在火焰出口0．15-0．4cm的反应区域内。

KINETIC SIMULATION OF PAHS FORMATION IN PREMIXED ETHANE LAMINAR FLAME

With the continuous improvement of the pollutants emission limits for environmental protection, people pay more concerns on the polycyclic aromatic hydrocarbons (PAHs) formation during combustion process. Based on the analysis of gas phase reaction pathways of PAHs formation, this paper presented the flame structure and PAHs concentration in the premixed ethane laminar flame under atmospheric pressure using detailed elementary reaction mechanisms, the predicted results agree well with experimental data. Using the method of sensitivity analysis for chemical reactions, the most important reactions on the effect of PAHs formation process, together with the benzene formation with different combustion equivalent ratios, were investigated. It about was also found that the main reaction position effected was 0.15 cm above the burner. The net rates of production of main reactions for A1~A4 were also calculated and their value varied sharply on the reaction zone of 0.15-0.40 cm above the burner.