基于比功率的北京快速公交车辆排放特征

Emission characteristics analysis of Beijing BRT vehicle based on VSP parameter

为研究北京快速公交系统运行车辆的尾气排放特征,从速度、加速度和行驶模式比例3方面对其运行工况进行分析;同时确定比功率参数(VSP)的计算公式,根据时间、空间条件的不同,基于VSP区间分析了BRT车辆排放特征,并研究4种排放物在不同VSP区间的排放贡献率.结果表明:随VSP值增加,排放物的排放率逐步增加,且高VSP值频率分布小,但其尾气排放贡献率大,对此提出相应对策,在高峰时段应给予BRT车辆优先通行权,并合理设置公交专用道比例及位置,优化BRT车辆运行工况,以降低高VSP情况出现的频率,以达到减少尾气排放污染的效果.

In order to study the emission characteristics of Beijing BRT vehicle,driving cycle was analyzed in view of velocity,acceleration,and driving mode ratio.As vehicle specific power formula was determined,the emission characteristics of BRT vehicles in different VSP bins were studied in terms of different time period and space.Moreover,the proportion of BRT vehicle emission in different VSP bins was compared.The results showed that the emission rate increased with the increase of the VSP,and in high VSP bins the proportion of emission was large although the frequency of high VSP values was low.Therefore,it was recommended that the driving cycle of BRT vehicles should be improved to reduce the frequency of high VSP value,BRT vehicles should be given priority in the peak time.Furthermore,the proportion and position of exclusive bus lanes should be determined in a reasonable way.