Effects of the olefin and aromatic content of gasoline on the automobile exhaust emission during normal/low temperature cold start and evaporative emission were studied using six gasoline samples with various hydrocarbon compositions and vehicles meeting China National Standard for automobile emission Ⅲ (E Ⅲ ) and emission standard Ⅳ (E Ⅳ). Results show that the effect of gasoline compositions on emission is significantly related with the types of vehicles, E Ⅳ vehicles exhibit the lowest emissions of HC, CO and NOx when using gasoline with an aromatic volume content of 35％ and an olefin volume content of 25％, indicating that the olefin content in gasoline is not the lower the better. The effect of aromatic content is also related to the engine technology, however, on the whole exhaust emissions decrease with the decrease of aromatic content. The total evaporative emission increases with the increase of gasoline olefin content. The HC and CO emissions during cold start at low temperature increase with the increase of the total content of olefin and aromatics.%使用不同烃组成的6种汽油分别在满足国Ⅲ、国IV排放标准的车型上进行了I型、IV型和VI型排放试验,研究了汽油烯烃、芳烃含量对常温冷启动后、低温冷启动后尾气排放和蒸发排放的影响.结果表明,汽油组成对排放的影响与汽车技术密切相关,在满足国IV排放标准的车型上,当芳烃体积分数为35%油品烯烃体积分数控制在25%时,HC,C0,NOx 三种排放物较低;芳烃含量对排放的影响与发动机技术相关,但基本上呈现出芳烃含量较低时排放也较低的趋势;总蒸发排放物随油品烯烃含量增加而增加;油品的非烷烃类烃含量(即烯烃含量与芳烃含量之和)越高,车辆低温冷启动后HC,CO排放越高.
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