行驶机动车尾气排放VOCs成分谱及苯系物排放特征

Study of the VOC source profile and benzene compounds emission of various motor vehicles

对宁波市10辆不同车型的机动车在实际道路行驶时的尾气排放进行了采样和分析,获得了不同车型机动车的VOCs排放成分谱.此外,分析了排放控制技术和行驶里程对苯系物排放的影响.结果表明,电喷技术车辆尾气中苯、甲苯和二甲苯等污染物明显低于化油器技术车辆;对于同一技术车辆,高行驶里程的出租车由于汽车的劣化使得苯、甲苯和二甲苯的排放量比低行驶里程私人车辆大大增加.检查维护制度(I/M)的实施将对减少有毒有害的汽车尾气排放有着重要意义.此外,对于使用了电喷和三元催化装置的车辆,冷启动将导致苯系物排放大大增加.

Exhaust gases for 10 taxis were sampled and analyzed, and their VOC source profiles were acquired. In addition, the impacts of emission control technology and vehicle mileage on benzene compounds emission were analyzed. The results show that the emissions of benzene, toluene and dimethylbenzene for vehicles with e｜ectronie fue｜ injection were lower than ＇~ho^e for vehicles with carburetors. Cold starts led to a great increase of benzene compounds emission for vehicles with electronic-injection ＋ 3-way catalyst technology. Benzene, toluene and dimethylbenzene emissions for taxis with high driving mileage were much greater than for those with low mileage. So, the enforcement of an inspection/maintenance （I/M） program will be very significant in controlling hazardous gas from cars.