摘要
研究了LNG-电混合动力公交车城市道路行驶排放性能。以一辆LNG-电混合动力公交车为研究对象,在典型公交线路上开展实际道路车载排放测试,通过PEMS(Portable Emissions Measurement System)和CAN总线实时采集排气污染物排放浓度、行驶速度、发动机转速和扭矩等数据。结果表明,公交车发动机运行工况主要分布在中低转速和负荷区,不同于ETC循环工况主要分布在中高转速和负荷区。计算发现公交车城市道路运行NO_x质量排放率远高于CO与HC,CO质量排放速率约为NO_x的1/100,HC质量排放速率约为NO_x的1/9。采用基于ETC循环功的功基窗口法计算发动机排气污染物比排放值,发现发动机平均输出功率偏低,测试样本功基窗口持续时间为ETC循环时长的1.4倍。测算结果表明,在全部有效功基窗口中,CO和HC比排放低于排放限值(征求意见稿),而NO_x比排放高于排放限值。研究表明,功基窗口法能有效分析LNG-电混合动力公交车排放,分析车载测试数据,得出的比排放数值能够反映车辆实际道路行驶排放水平。
This paper takes it as its goal to trace the currently adopted authentic road driving emission exhaust of LNG-electricity hybrid communal buses. For the research goal,we have done a series of on-road emission tests on the typical communal bus routes by taking a specific LNG-electricity hybrid urban communal bus as the research subject. In doing so,we have managed to collect the experimental data,such as the instantaneous gas-emission concentration of the gas pollutants,the bus driving speed,the working speed and torque of the engines,etc. by means of the portable emission measurement system（ PEMS） and CAN-BUS.Different from the European transient cycle（ ETC） operating points which are mainly distributed in the middle or high speed buses in the urban load areas,the results of our investigation show that the operating conditions of the bus engines driven are mainly distributed in the middle or low speeds in the urban community load areas. In such urban road transportation conditions,the mass emission levels of NO_xgenerated by the communal buses have been found to be much heavier than those of CO and HC.More specifically speaking,the mass emission rate of CO used to be merely one percent of NO_x,with the mass emission rate of HC being merely one-ninth of NO_x. In addition,the brake-specific emission of the engine has also to be taken into account by using the work-based window method which is based on ETC cycle work. Thus,the result of our statistics indicate that the duration of the work-based window is 1. 4 times longer than the ETC cycle,which is due to the low average power output of the engine.Among all the valid work-based windows, the brake-specific emissions of CO and HC have been found lower than the emission limits in accordance with the Chinese emission standard（ draft for comment）,but the brake-specific emission of NO_xmay severely exceed the emission limit. All in all,the aforementioned study results show that the method of the work-based window is effective and applicable for the analysis
出处
《安全与环境学报》
CAS
CSCD
北大核心
2017年第6期2382-2387,共6页
Journal of Safety and Environment
基金
2015年广州市战略性主导产业发展资金交通行业节能专项资金项目
关键词
环境学
城市公交车
道路排放
车载法
功基窗口法
environmentalology
urban bus
on-road emission
PEMS method
work-based window method
