南京市轻型车不同工况下污染物排放分析

Analysis of Pollutant Emission by Light Vehicles Under Different Driving Cycles in Nanjing

为对比南京市市区轻型车实际行驶工况与标准工况(含检测工况)在工况特征和排放特性上的差异水平,以南京市轻型汽油车为对象,采用车载测试系统和底盘测功机对各种工况进行排放测试。标准工况的CO2、CO和HC的平均排放速率是实际工况下的1.2～2.4倍,实际行驶工况下对应的污染物排放速率是标准工况下的1.1～2.2倍。由于实际道路运行条件下的车辆频繁加减速,导致实际工况的NOx排放速率高于标准工况的NOx排放速率(达到1.3倍)。结果显示,检测工况可以合理反映出实际道路下的匀速和怠速排放情况,但检测工况下的排放速率较低。标准工况仅能反映出污染物的基本排放规律,不能较好地表达实际工况车辆频繁加速、减速导致的污染物排放差异。

To compare the difference between the real-world driving cycle and standard driving cycle (including a test cycle), light-duty gasoline vehicles were tested on urban roads in Nanjing using a portable emission measurement system and chassis dynamometer. The pollutant emission rates of CO2, CO, and HC under the standard driving cycle were observed to be 1.2 to 2.4 times the corresponding rates under the constructed driving cycle. Emission rates of CO2, CO, and HC under the constructed driving cycle were observed to be 1.1 to 2.2 times these rates under the test driving cycle. The results show that the current test driving cycle can be adopted to predict the pollutant emission under conditions of cruising and idle;however, the values are lower than actual. The frequent acceleration and deceleration under the real-world driving conditions cannot be represented in totality by the new European driving cycle.