重型卡车实际道路颗粒物排放特征

Study of PM Number Concentration and Size Distribution from a Heavy-duty Truck Using PEMS

为获得重型卡车实际道路颗粒物数浓度和粒径分布排放特性,利用车载测试系统(PEMS)在实际道路上对重型卡车颗粒物数浓度及粒径分布进行了研究。结果表明:在不同车速下30s的稳定工况内,排放的颗粒物数量变化不大;不同工况粒径分布结果类似,均为单峰分布,怠速工况颗粒物数浓度峰值处于粒径20nm颗粒物,其余工况峰值处于粒径70nm的颗粒物,随着车速的增加,颗粒物数浓度向粒径增大方向移动;各种工况下粒径大于770nm的颗粒物非常少,在总数量中所占比例不足0.1%。

Measurements of particle number emissions and particle size distributions from a heavy-duty truck were performed using a Portable Emission Measurement System （PEMS）. The results showed that there were no large changes in particle number concentration over 30 seconds of steady-state operation at different speeds. The results of size distribution of particle number concentration from the truck indicated that the distributions were similar at different vehicle speeds, and showed a unimodal peak distribution. The peak concentration of particles occurred at the diameter of 70 nm except that at idle mode the number was 20 nm. The diameter of particles was greater with the increase of the vehicle speed. There were very few particles with diameter greater than 770 nm, which occupied less than 0. 1% of the total.