柴油轿车燃用生物柴油的模态颗粒排放特性

以帕萨特柴油轿车为试验样车,使用排气颗粒数量及粒径分析仪(EEPS),对分别燃用沪Ⅳ柴油、生物柴油混合体积分数分别为5%,10%,20%和50%的沪Ⅳ柴油-生物柴油混合燃料、纯生物柴油的模态颗粒排放特性进行了试验研究.结果表明:GB18352.3—2005Ⅰ型试验循环中,该车燃用生物柴油的聚集态颗粒数量浓度下降,核模态颗粒数量浓度上升,总颗粒数量浓度变化不大;随着生物柴油混合比例的增加,该车燃用沪Ⅳ柴油-生物柴油混合燃料排气颗粒的平均粒径降低,颗粒数量浓度峰值向小粒径方向偏移.

NEDC Particle Number and Size Emission Characters of a Diesel Car Fueled with Biodiesel Blends in Laboratory

Biodiesel fuel blends were used on a diesel car,and the effects of biodiesel on vehicle’s particle number and size emission characters were studied with an engine exhaust particle sizer(EEPS) at new European driving cycle(NEDC) test.A test was made without any engine modification on a pure petroleum diesel and a pure biodiesel as well as some blends of petroleum diesel-biodiesel with the blend ratio of 5%,10%,20% or 50% respectively.The results show that the total concentration of particle number reduces little when the car is fueled with biodiesel.The number of accumulation mode particles decreases whereas the number of nucleation mode particles increases significantly with the increasing of the blend ratio of biodiesel.At the same time,the average diameter of particle matters decreases and the peak of particle number concentration shifts to small diameter particle side.