机动车排放污染的速度-加速度耦合影响分析

利用OBS-2200车载测试系统,分别在高峰期、平峰期和低峰期的天津市典型路段进行了车载测试,并获得了碳氢化合物(HC)、一氧化碳(CO)和氮氧化物(NOx)等车辆排放的污染物的逐秒数据.结果显示在这3个时段内,车辆的加速度大都集中在-1.5~1.5m/s2,速度大都集中在0~70km/h,并且HC、CO和NOx的最高排放率为0.0673、0.706和0.0178g/s,都集中在高速(速度(v)>30km/h, 加速度(a)>0.5m/s2)工况范围内.通过拟合发现,HC、CO和NOx的排放率与比功率(Vehicle Specific Power,简称VSP)之间的拟合决定系数分别为0.71、0.86和0.85,相关性较高,说明VSP可以作为评价车辆排放率的一个重要参考性指标.

Coupling effects of speed and acceleration on light duty vehicle emissions

OBS-2200 on-board emission measurement system was used to analyze car emission in Tianjin’s typical roads in busy time (17:00~18:00), common time (14:30~15:30) and free time (20:00~21:00), respectively, and the second by second emission rates of HC, CO and NOx were also obtained. The results demonstrated that the accelerations of vehicle were within -1.5~1.5m/s2, and the speeds of vehicle were within 0~70km/h generally. The highest emission rates of HC, CO and NOx were 0.0673g/s, 0.706g/s and 0.0178g/s, all of which concentrated within the operating conditions of high speed and high acceleration (v>30km/h, a>0.5m/s2). Coefficients of determination between the emission rates (HC, CO and NOx) and VSP were 0.71, 0.86 and 0.85, which showed that VSP can be referred as an indicator of vehicle emission.