汽油代表性组分在预混火焰中的碳烟生成特性及动力学分析

摘要

With detailed gas phase kinetic model and particle phase model of soot,this paper studied the characteris-tics of soot formation in fuel-rich premixed flame using numerical simulation. Comparisons between the calculated and experimental results show that the detail models and computational method of soot can,to some extent,describe the evolution of soot. Then the characteristics of soot formation for five representative species of gasoline(iso-octane,n-heptane,toluene,diisobutylene,and ethonal)were comparatively studied. The results show that aro-matic hydrocarbons can easily produce soot,while ethonal cannot. And alkene can produce soot more easily than alkane. Moreover,through kinetic analysis,the path ways of soot formation for five species were given,which can interpret the qualitative conclusions obtained from calculations.%采用详细碳烟气相模型和颗粒相模型，在富燃料预混火焰中对碳烟的生成特性进行了数值研究，计算结果与实验对比表明，详细模型及碳烟计算方法在一定程度上能够描述碳烟演变过程。进而对比研究了异辛烷、正庚烷、甲苯、二异丁烯、乙醇等5种汽油代表性组分的碳烟生成特性，研究结果显示，芳烃类燃料易生成碳烟，而乙醇不易生成碳烟，烯烃比烷烃燃料易生成碳烟。并通过动力学分析了不同燃料生成碳烟的途径，解释了计算得到的定性结论。