乘客载重量对柴油公交车尾气排放影响分析

摘要

The influence of passenger load on diesel bus emission was analyzed based on the real‐world emission data collected by the portable emission measurement system (PEMS) . Whether passenger load affected the accuracy of emission models based on vehicle specific power (VSP) was analyzed .The number of passengers getting on and off the bus was recorded so that the real‐time ridership data was obtained . The passengers were divided into six groups according to the age and gender .Then the passengers load was calculated with coefficient in each group . Results show that the influence of passenger load on emission rates of CO2 ,CO ,NOx and HC is various with different speed and acceleration bins .As for the distance‐based emission factors ,the influence of passenger load isn’t obvious w hen the bus is driving at a relative high speed .Per‐passenger emission factors decrease with the rise of passenger load .The influence of passenger load can be omitted properly in the emission models of low and medium speed bins .The passenger load cannot be omitted in the models for high speed and high VSP bins .Otherwise ,that can lead to an error reaching up to 49% w hen the influence of passenger load is neglected in the models of high speed bins .%基于车载尾气排放测试系统（PEM S ）数据，分析柴油公交车在实际运行状态下，载重量变化对排放的影响。探究忽略乘客载重量变化是否会影响比功率（VSP）计算及进行分组。乘客数量可由车载排放测试实验记录得出，根据年龄及性别将公交车乘客分为6组。乘客载重量可以由每组乘客载重量计算系数估算相加得出。研究结果表明，在不同的速度及加速度区间，乘客载重量变化对CO2、CO、NOx 、HC 4种排放物的瞬时排放率会产生不同程度的影响。对基于距离的排放因子而言，在平均速度较高的行驶区间内，乘客载重量的变化不影响4种污染物排放因子；随着乘客载重量的增加，人均排放因子逐渐减小。在低速及中速排放估算模拟中可以适当忽略公交车载重量变化对排放带来的影响，但在高速的排放估算模拟中，忽略载重量的变化会带来很大的误差，就实验测试车辆而言，计算误差最大可以达到49％。