用不同算法时载荷条件对重型车比排放影响的对比试验

Comparative test of influence of load conditions on specific emissions of heavy-duty vehicles with different calculation methods

为了定量评价重型车单位行驶里程排放、单位发动机做功排放水平随载荷比例的变化情况,对于6辆国Ⅵ标准车辆和2辆国Ⅴ标准车辆,使用车载排放分析系统,进行了不同载荷比例的实际道路工况排放试验。结果表明:国Ⅵ车辆单位行驶里程颗粒物数量(PN)排放载荷修正系数随着载荷比例的增大而显著增加,拟合曲线斜率为0.0119,而国Ⅴ车辆的斜率为0.0012,远低于国Ⅵ车辆。随着载荷比例的增大,国Ⅵ重型车单位发动机做功的PN和NO_(x)排放增加,CO_(2)排放不变,CO排放降低;行驶相同的里程时,载荷比例越大的国Ⅵ重型车,单位质量整车的PN排放水平越高,CO、CO_(2)和NO_(x)排放水平越低。在高载荷比例条件时,国Ⅵ车辆在最初的市区阶段和最后的高速阶段出现了很高的PN峰值。

The on-board emission analysis system was used to carry out the actual road emission tests with different load ratios to quantitatively evaluate the variation of emission per unit mileage and emission per unit engine work with load ratio of heavy-duty vehicles,using 6 vehicles of stage VI of the National Standard and 2 vehicles of stage V of the National Standard.The results show that the load correction coefficient of particulate number(PN)emission per unit mileage of stage VI vehicles increases significantly with the increase of load ratio,and the slope of the fitted curve is 0.0119,while the slope of stage 5 vehicle is 0.0012,which is much lower than that of stage VI vehicle.With the increase of the load ratio,the PN and NO_(x) emissions per unit engine work increase,CO_(2) emissions remain unchanged,and CO emissions decrease.When driving the same mileage,the larger the load ratio,the higher the PN emission level per unit vehicle mass,and the lower the emission levels of CO,CO_(2) and NO_(x).Under the condition of high load ratio,the National VI vehicles show high PN peaks in the initial urban stage and the final high-speed stage.