轻型汽车实际行驶排放评估方法研究

按照轻型汽车实际行驶排放测试流程,采用便携式排放测试系统测量3辆满足《轻型汽车污染物排放限值及测量方法(中国第五阶段)》要求的轻型汽车实际行驶排放,并使用欧盟提出的移动平均窗口法对排放数据进行处理。结果表明:冷起动阶段的CO,NO_x和PN排放占整个试验总排放的比例分别为69.9%,23.1%和68.8%。将冷起动阶段排放纳入计算时,CO,NO_x和PN的排放结果分别比剔除冷起动阶段排放的结果高19.5%,4.3%和16.3%。温和驾驶时车辆CO_2排放较低,导致过多窗口无法落入正常区域,窗口不能满足正常性要求。欧盟提出的移动平均窗口法不适合直接用于评估中国轻型汽车实际行驶排放,对基本公差tol1进行修正,随着tol1的增加,落入正常区域的窗口随之增多,试验通过正常性要求的比例也随之增大,但tol1的修正会带来巨大的标定工作量。

Evaluation Method of Real Driving Emission for Light-duty Vehicle

The real driving emissions of three light-duty vehicles that met the China fifth stage legislation of limits and meas-urement methods for emissions from light-duty vehicles were measured with the portable emission measurement system and the emissions data were processed using the moving average window method proposed by EU.The results show that the CO,NO x and PN emissions in the cold start stage account for 69.9%,23.1% and 68.8% of total emissions respectively.Taking the cold start emission into account,the results of CO,NO xand PN emissions will increase by 19.5%,4.3% and 16.3%.For the mild driving,the CO2emission is so low that too many windows cannot fall into the normal areas and hence the window cannot meet the normal requirements.Therefore the moving average window method proposed by the EU cannot be directly applied to eval-uate the real driving emission of light-duty vehicle in China.With the increase of amended basic tolerance tol1,the number of windows that fall into the normal area increases and the proportion of test that passes through the normal requirement also in-creases.However,the basic tolerance amendment will bring lots of calibration work.