Effects of oxygen and propane addition on soot formaiton in ocunterflow ethylene flames and the role of C_3 chemistry

摘要

The influence of oxygen addition and porpane addition on soot formaiton is investigated experimentlaly in counterflow ethylene diffusion flames,and numerical calcuationsw ith detailed chemical reciton mechanisms are ocnducted to interpret expeimentall results.Soot volume fractions and polycylic aromatic hydrocarbon (PAH) concentrations increase with a small amount of oxygen addition for ethylene diffusion falmes but not for propane diffusion flames.THis result supports tha tthe reactions between O atoms and C_2H_2 produce CH_2 and eventually form C_3H_3,which are repsponible for the enhancement of incipent rings and thereby PAH and soot formaiton through C_3H_3 recombination reaction.