乙烯/氧气预混火焰中燃空当量比对碳烟表面官能团和氧化活性的影响

摘要

In this paper,the effect of equivalence ratio on the surface functional groups and oxidation reactivity of soot and the correlations between surface functional groups and oxidation reactivity of soot were studied.Experiments were performed in a burner-stabilized ethylene/oxygen /argon premixed flame,and the soot was collected by an in-situ capillary system and analyzed using several advanced technologies.Research results suggest that as the equiva-lence ratio increases,the relative content of aliphatic C—H decreases due to a gradual decrease in the peak area ratio of aliphatic C—H to aromatic C=C.Simultaneously,a general decrease is found in the molar percentage of oxygen-ated surface functional groups(C—OH and C=O).By contrast,the oxidation reactivity temperature and apparent activation energies increase with an increase in the equivalence ratio,indicating a decreased oxidation reactivity of soot.Surface functional groups have an effect on the oxidation reactivity of soot.The more surface functional groups there are,the higher oxidation reactivity for the soot is.The aliphatic C—H functional groups act as a more important factor than the two oxygenated functional groups in governing soot oxidation.%采用乙烯/氧气/氩气预混燃烧系统和毛细管取样系统并结合多种先进分析技术，研究了预混火焰燃空当量比对碳烟颗粒表面官能团及其氧化活性的影响。结果表明，随燃空当量比的增加，碳烟颗粒表面脂肪族 C—H 官能团和含氧官能团(C—OH和C＝O官能团)的摩尔分数均呈下降趋势；而碳烟颗粒的氧化反应特征温度和表观活化能呈增大趋势，表明在较大燃空当量比下所生成碳烟颗粒的氧化活性较低；碳烟颗粒表面官能团对氧化活性有着直接作用，表面官能团含量越多，其氧化反应活性越高。碳烟颗粒表面脂肪族 C—H 官能团对其氧化活性影响相对较大，而含氧官能团影响相对较小。