低温等离子体降低柴油机多环芳香烃的试验

Experiment on removal of polycyclic aromatic hydrocarbons emissions in diesel engine exhaust with non-thermal plasma

在186FA单缸柴油机上，采用玻璃纤维滤纸及XAD-2吸附管采集低温等离子体（non-thermal plasma，NTP）作用前后多环芳香烃（polycyclic aromatic hydrocarbons，PAHs）样品，结合气质联用分析技术，研究了不同工况下NTP对PAHs的作用效果．结果表明：原机中二环和三环PAHs的质量浓度随负荷的增加呈先升高后降低的趋势，四环及五环PAHs的质量浓度随负荷的增加先降低后升高；NTP对屈（Chrysene）的去除效果最好，去除率最高可达78．63％；NTP作用后，PAHs排放总量明显降低，最大降幅达到37．87％；NTP作用前后各环PAHs平均排放质量浓度均随环数的增加而降低，二环PAHs所占百分比最大，NTP作用后各环的PAHs平均排放质量浓度均比原机有所降低，降幅为17．9％-31．0％．

In 186FA single cylinder diesel engine, the polycyclic aromatic hydrocarbons （PAHs） samples before and after non-thermal plasma （NTP） were collected by glass filters and XAD -2 collectors, and the effects of NTP on PAHs emissions at various loads were analyzed combined with the gas chromatography-mass spectrometry （GC - MS）. The results indicate that original emissions of PAHs with two rings and three rings increase firstly and then decrease with the increasing of load, while the trends with four rings and five rings are reversed. The removal effect of NTP on CHR is the best with the highest removal rate of 78.63%. The total emissions of PAHs are reduced evidently after NTP with the maximum removal efficiency of 37.87%. The average emissions of PAHs before and after NTP decrease with the increasing of benzene rings, and the PAHs emissions with two rings account for the largest percentage. The average emissions of PAHs with different rings are reduced after NTP with the removal rate from 17.9% to 31.0%.