【摘要】 采用便携式仪器,借鉴双怠速尾气检测法,利用自行设计的尾气采样装置,选择济南市区道路上10辆不同类型的机动车,现场测量尾气颗粒物的质量浓度和数浓度.基于实验数据,分析了机动车尾气颗粒物污染特征,深入探索了影响尾气颗粒物浓度的主要因素,提出了相应的对策建议.结果表明:①怠速工况下机动车尾气中PM_2.5和PM₁₀质量浓度、PM_0.01～1数浓度较低,平均分别为0.035～1.434和0.049～3.669 mg·m^-3、（0.95～21.69）×10⁴ cm^-3;高怠速工况下颗粒物质量浓度和数浓度较高, PM_2.5质量浓度为0.350～5.132 mg·m^-3,最大值来自大型柴油货车8.394 mg·m^-3; PM₁₀质量浓度高达1.708～7.862 mg·m^-3,最大值来自大型柴油客车8.672 mg·m^-3; PM_0.01～1数浓度为（6.78～40.68）×10⁴ cm^-3.②随着发动机转速和车型增大、排放标准降低,机动车尾气中颗粒物质量浓度和数浓度明显升高.与怠速工况相比,高怠速工况下的PM_2.5质量浓度升高3～44倍, PM_0.01～1数浓度升高2～33倍.与小型车相比,中、大型车的PM_2.5质量浓度升高约5倍, PM_0.01～1数浓度升高约2倍.使用92号汽油排放的颗粒物质量浓度与数浓度约为95号汽油车的2倍,柴油车排放的颗粒物浓度高于汽油车.国III标准的汽油车尾气颗粒物的质量浓度与数浓度约是国IV和国V标准的2～4倍.③提高机动车排放标准和燃油品质,减少在实际道路行驶中突然加速或启动等高怠速工况的瞬态变化,加强对中、大型车尤其是大型柴油车的监管,能够一定程度上减轻机动车尾气颗粒物污染.更多还原

【Abstract】 Mass concentration and number concentration of exhaust particles from 10 different vehicles on the roads in urban Jinan were measured in situ by using portable instruments coupled with self-designed exhaust sampling device with double idle speed exhaust detection method as a reference. Based on the experimental data, the pollution characteristics, main factors influencing the emission of vehicle exhaust particles were analyzed deeply followed by corresponding suggestions. The results show that: ① Under idling mode, the PM_2.5 and PM₁₀ mass concentrations and PM_0.01～1 number concentration of vehicle exhaust were relatively low, with the average concentration of 0.035～1.434 and 0.049～3.669 mg·m^-3,（0.95～21.69）×10⁴ cm^-3, respectively. By contrast, the mass and number concentrations under high idling mode were very high. The average PM_2.5 mass concentration was 0.350～5.132 mg·m^-3, with the maximum value of 8.394 mg·m^-3 from large diesel van. The average PM₁₀ mass concentration was 1.708～7.862 mg·m^-3, with the maximum value of 8.672 mg·m^-3 from large diesel passenger bus. The average PM_0.01～1 number concentration was（6.78～40.68）×10⁴ cm^-3. ② With the rising engine speed, increasing vehicle size and constricting emission standard, the mass and number concentrations of exhaust particles increased significantly. When compared with idling mode, PM_2.5 mass concentration in high idling mode increased by a factor of 3～44 and PM_0.01～1 number concentration increases by a factor of 2～33. Compared with small vehicles, the PM_2.5 and PM_0.01～1 concentrations of medium and large vehicles increased by a factor of about 5 and 2, respectively. The mass and number concentrations of particles emitted from vehicles with 92^# gasoline were about twice those with 95^# gasoline, and the particle concentrations from diesel vehicles were higher than those from gasoline vehicles. The mass and number concentration of exhaust particles from vehicles of National III Standard increased by a factor of 2～4 when compared with the vehicles of National IV and V Standards. ③The corresponding suggestions to the influencing factors can to a certain degree mitigate the particle pollution from vehicle exhausts, including constricting the vehicle emission standards, improving fuel quality, reducing the transient changes at high idling mode in the condition of sudden acceleration or starting, and strengthening the regulation of medium and large vehicles, especially the large diesel vehicles.更多还原