废气再循环成分对扩散燃烧中碳烟形成影响的研究

Study of the Influence of EGR on Soot Formation in Diffusion Flames

通过测量对置射流扩散火焰中开始形成碳核时的临界气动变形率Kp和同轴扩散火焰碳烟的体积浓度,当燃烧废气的主要成分CO2和N2加入到燃料气流及形成扩散火焰的空气流中时,对碳烟生成到排出各过程的影响进行了实验研究。通过适当的火焰温度调节,研究了它们在碳烟生成各过程中的化学作用。结果显示,废气再循环成分CO2和N2对扩散火焰碳烟生成的各个过程并无增加碳烟排放量的作用,反而遏止碳烟的成核和聚合长大,这两种成分对碳烟的氧化,也没有十分明显的不利影响。

An experimental study on the influence of the EGR (exhaust gas recirculation) composition on the soot formation in diffusion flames has been conducted by measuring the soot inception limits Kp and the soot loading in the coflow diffusion flames when different percentage CO2 or N2 is added to the oxidizer or fuel flow.The results show that the EGR composition CO2 and N2 addition suppress the soot formation in the soot inception process and soot growth of the diffusion flames.No obvious adverse effect of these two species on soot oxidation has been observed.