Abstract: Experiments were conducted on three major emission reduction technical routes including China's fifth-stage city bus including Selective Catalytic Reduction, Exhaust Gas Recirculation+ Diesel Oxidation Catalyst+Diesel Particulate Filter and natural gas buses. The general packet radio service (GPRS) communication module of each bus transmits the collected data to the remote monitoring platform server at a frequency of 1 Hz. The NOx emission rate is calculated based on the NOx data to determine the NOx emissions of the vehicle under different driving conditions and in each speed range. The results indicate that the single Selective Catalytic Reduction post-treatment mode shows a higher NOx emission rate and needs to be improved. The post-treatment Exhaust Gas Recirculation+Diesel Oxidation Catalyst+Diesel Particulate Filter bus shows a lower emission rate and is considered to be the optimal post-processing method within the research range.

Key words: Online monitoring technology; Post processing technology; Bus; NOx emission rate

摘要： 对国五阶段城市公交车包含选择性催化还原系统，废气再循环系统+氧化型催化器+柴 油机颗粒捕捉器和天然气公交车在内的三种主要减排技术路线进行试验研究。每辆公交车的 通用分组无线服务技术（GPRS）通讯模块以 1 Hz 的频率将采集数据传输至远程监控平台服 务器。根据 NOx 数据计算出 NOx 排放速率，确定车辆在不同行驶工况下以及各段速度区间 内 NOx 的排放情况。结果表明单一选择性催化还原系统后处理方式呈现出较高的 NOx 排放 速率而有待改进，后处理方式为废气再循环系统+氧化型催化器+柴油机颗粒捕捉器的公交车 表现出较低的排放速率，被认为是在研究范围内较优的后处理方式。

关键词: 在线监测技术；后处理技术；公交车；NOx 排放速率