轻型汽油车简易瞬态工况法与定容全流稀释采样法(CVS)的排放相关性  

Correlations of Light-duty Gasoline Vehicle Emissions Based on VMAS and CVS Measurement Systems

作　　者：王鸿宇[1] 黄成[2,3] 胡磬遥[2,3] 李莉[2,3] 陈勇航[1] 徐健[1] 

机构地区：[1]东华大学环境科学与工程学院,上海201620 [2]上海市环境科学研究院,上海200233 [3]国家环境保护城市大气复合污染成因与防治重点实验室,上海200233

出　　处：《环境科学》2017年第6期2294-2300,共7页Environmental Science

基　　金：国家科技支撑计划项目(2014BAC22B03);上海市科委项目(15DZ1205500)

摘　　要：选取25辆国2~国5标准在用轻型汽油车分别采用简易瞬态工况法(VMAS)与定容全流稀释采样法(CVS)开展了排放实测,分析了两种方法实测的排放因子相关性.结果表明,轻型汽油车排放水平总体随排放标准提升而呈下降趋势,国2和国3标准车辆中存在一定的高排放现象,国4及以上标准车型排放相对较低.VMAS和CVS方法的排放相关性随标准提升而显著下降,对国4及以上标准车辆的CO和HC+NO_x排放的相对偏差分别达到197%和177%.对较高排放车辆,两种方法检测结果的相关系数达到0.75~0.85;对较低排放车辆,相关系数仅为0.46左右,若将在用车排放标准进一步收严,采用VMAS检测的误判率将显著上升.随着我国机动车排放水平的不断下降,总体来看,VMAS检测对高排放标准车辆的适用性相对较差,有必要在用车排放检测方法方面开展更为深入的研究.Gaseous emissions from 25 State 2-5 light-duty gasoline vehicles were tested by Vehicle Mass Analysis System （VMAS） and CVS （Constant Volume Sampling） system, respectively. The correlations of emission factors of tested vehicles measured by these 2 methods were analyzed. The results showed that emission factors of light-duty gasoline vehicle had a decreasing trend with the promotion of emission standard. There were some high-emitting vehicles in the fleet of tested State 2 and State 3 vehicles, but fewer in State 4 or Stated 5 vehicle fleet. The correlations of the emission factors measured by the 2 methods deteriorated with the promotion of emission standard. The relative bias of CO and HC＋NOx emission factors measured by the 2 methods reached 197% and 177%, respectively. The correlation coefficient of emission factors of higher-emitting vehicles was 0.75-0.85, while that of lower-emitting vehicles was only 0.46. If tighter emission standard of in-use light-duty gasoline vehicle was adopted, the false positive rate of measurement results by VMAS would rise significantly. In summary, VMAS method is hard to be applied in the emission measurements of light-duty gasoline vehicles with stricter emissions standard. It is necessary to conduct more studies on sophisticated in-use vehicle measurement system.

关 键 词：机动车排放 轻型汽油车 排放因子 简易瞬态工况 定容全流稀释采样 

分 类 号：X51[环境科学与工程—环境工程]