掺混甲烷对预混合丙烯火焰碳烟生成的影响

Effect of Methane Blending on Soot Formation in Premixed Propene Flame

基于当量比为1.79且最高火焰温度为1829 K的预混合丙烯火焰,研究了燃料掺混对碳烟生成的影响以及协同效应.分别将5%、20%、40%摩尔分数的甲烷混合到丙烯中,形成具有相同当量比和最高火焰温度的预混火焰.使用微孔探针采样技术和扫描电迁移率粒径谱仪,在燃烧器稳定滞止火焰中测量了碳烟粒径分布.研究发现,掺混甲烷后的火焰生成碳烟颗粒粒径仍旧呈现双峰性分布;但随甲烷掺混率增加,双峰性减弱,颗粒生长速率减弱,碳烟体积分数也迅速减小.在所研究的试验工况下,丙烯与甲烷在碳烟生成方面不仅没有协同效应,而且甲烷的添加降低了碳烟颗粒的生长速度和碳烟生成总量.

Mole fraction of 5%,20%and 40%of methane was blended in propene to form a propene premixed flame.The influence of methane blend on soot formation and the synergistic effect was studied in the flame at the same equivalent ratio of 1.79 and the same maximum flame temperature of 1829 K.The soot particle size distribution was measured in the stable stagnation flame using the micro hole probe sampling technique and a scanning electromigration particle size spectrometer.It is found that soot particles produced by the methane blending flame still exhibits a bimodal distribution.However,as the methane blending ratio increases,the particle growth rate decreases,and the soot volume fraction decreases rapidly.No synergistic effect was observed under the experimental conditions studied between propene and methane on soot production.Moreover,methane addition reduces the particle growth rate and the total amount of soot.