汽油多环芳香烃排放的试验研究

Experimental Study on Emissions of Polycyclic Aromatic Hydrocarbons of Unleaded Gasoline

为了解三元催化器对汽油燃烧过程中多环芳香烃生成的影响,在HL495IQ电喷汽油机上进行了台架试验,通过气相色谱-质谱联用（GC-MS）分析仪测试了几种多环芳香烃的排放量。试验结果表明,排气温度在200~600℃时,多环芳香烃主要源于未完全燃烧的燃油;排气温度在600~800℃时,随温度的升高燃油裂解出更多的自由基团,从而促使生成更多的多环芳香烃。在三元催化器中存在着多环芳香烃的合成与转化2个趋势,哪个趋势占主导地位取决于多环芳香烃各自的性质和反应条件。

In order to study the effect of three-way catalytic converter on generation of polycyclic aromatic hydrocarbons（PAH）in gasoline combustion process,tests were made in a HL495IQ electronic fuel injection gasoline engine.The emissions of several kinds of PAHs are measured by a gas chromatography-mass spectrometry（GC-MS） analyzer.The test results show that PAH is generated mainly by fuel which is not burnt completely at exhaust temperature of 200~600 ℃.With the increase of exhaust temperature to 600~800 ℃,the fuel will be broken up into more free radicals,which results in more PAH being generated.In three-way catalytic converter,PAH may be synthesized or converted,the nature and reaction condition of PAH determines which trend dominates.