西安市机动车尾气排放特征分析

EMISSION CHARACTERISTICS OF VEHICLE EXHAUSTS IN XI'AN CITY

根据车辆类型及排放因子计算西安市机动车尾气污染物排放CO、碳氢化合物(HC)、氮氧化物(NOx)及颗粒物(PM)的特征。结果显示,机动车排放污染物中一氧化碳含量远大于其他三者。CO和HC主要来自客车,尤其是小型客车,而颗粒物主要由重型货车排放;超过80%的CO和HC来自汽油车,而超过90%的PM排放来自柴油车;国Ⅰ前汽车在西安市汽车保有量中仅占3.48%,而四种污染物排放量在的比例分别为33.55%、29.68%、11.92%和21.43%。为减少机动车尾气污染物的排放,建议淘汰国Ⅰ前车辆,对柴油车尾气加强处理。

In the current work,emission characteristics of CO,HC,NOxand PM from vehicle exhaust were studied in Xi'an city. It showed that CO emitted by vehicle was far higher than the other three kinds of pollutants. According to different vehicle types,HC and CO were mainly emitted by passenger cars,while PM was mainly emitted by heavy goods vehicles. In view of fuels,more than 80% of CO and HC were from gasoline vehicles,while more than 90% of PM were from diesel vehicles. According to the different national emission standards vehicles complying with the national vehicle emission standard I,account for only 3. 48% in the total vehicle number in Xi'an,but they emitted 33. 55% of CO,29. 68% of HC,11. 92%of NOxand 21. 43% of PM. Abandoning old cars and cleaning the heavy goods vehicle and diesel vehicle exhausts would be helpful to mitigate the pollutant emissions.