轻型柴油车尾气烟羽中颗粒数量与粒径分布(英文)

Particle Number and Size Distributions along the Vehicular Exhaust Plume from a Light-Duty Diesel Vehicle

测量了轻型柴油车在高怠速和低怠速运转的条件下,其尾气烟羽中粒径范围在15 nm到30μm的颗粒数量和粒径的分布。利用SMPS和APS测量装置测量尾气烟羽中心线和环境背景条件下的颗粒排放。测量结果表明,测试的柴油车在高怠速运转的条件下会排放出更多的颗粒。然而,在两种怠速条件下,总的颗粒数量浓度由于沉降的作用会随着远离排气管的距离而减少。测量结果还表明,柴油车排放的颗粒主要是粒径小于700 nm的颗粒,这些细颗粒比粗颗粒更易长期悬浮于大气中,从而引发局部的颗粒物污染问题。

The characteristics of particle number and size distributions ranging from 15 nm to 30μm along the vehicular exhaust plume emitted from a light-duty diesel vehicle under the low and high idling conditions were examined. The sampled exhaust particles were analyzed using the scanning mobility particle sizer （SMPS） and the aerodynamic particle sizer （APS） along the centerline of vehicular exhaust plume and under the environmental background. The results showed that the total particle number concentrations emitted from the tested diesel vehicle at high idling condition were much higher than those at low idling condition. However, the total particle number concentrations for both of idling conditions decreased with the distance departing from the exit port due to the deposition process. The results also indicated that most of particles from diesel vehicle were the fine particles less than 700 nm in diameter, and those particles would suspend longer time in the atmosphere than the large particles, resulting in the local particulate pollution.