Identifying NOx Hotspots in Transient Urban Driving of Two Diesel Buses and a Diesel Car
Identifying NOx Hotspots in Transient Urban Driving of Two Diesel Buses and a Diesel Car
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DOI：
10.3390/atmos11040355
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发表时间：
2020-04-01
期刊：
影响因子：
2.9
通讯作者：
Hammond, Matthew J.
中科院分区：
文献类型：
--
作者：
Leach, Felix C. P.;Peckham, Mark S.;Hammond, Matthew J.
由于车辆排放的氮氧化物对城市空气质量的影响，它们一直是令人担忧的重要原因。特别是，尽管在立法上减少了允许排放的水平，但在现实世界中并没有观察到这种减少。在这项工作中，三种车辆的氮氧化物排放——欧5轿车、欧5混合动力巴士和欧6混合动力巴士——在实际驾驶条件下进行了测量（以巴士为例，在全面载客服务的情况下）。最近开发的高时空分辨率技术结合了非常快（10毫秒）的氮氧化物测量和精确到1厘米的差分GPS，可以将这些排放分解到不到10厘米的距离（最坏的情况取决于车速）。结果表明，车辆的加速事件在其NOx总排放量中起着重要作用。此外，标准事件，如减速带和公共汽车站进行了分析。任何后处理（催化转化器）的温度，以减少氮氧化物排放也观察到实质性的意义。在空闲状态下，当空调打开时，乘用车的氮氧化物排放量几乎增加了一倍。最后，将实际驾驶条件与公共汽车认证的立法合规周期进行比较，并将这些结果用于进一步了解观察到的氮氧化物排放。
NOx emissions from vehicles have been a substantial cause for concern due to their impact on urban air quality. In particular, despite reducing levels of permitted emissions legislatively, such reductions have not been observed in the real world. In this work, NOx emissions from three vehicles-a Euro 5 car, a Euro V hybrid bus, and a Euro VI-bus have been measured in real driving conditions (and in the case of the buses-in full passenger service). A recently developed high spatio-temporal resolution technique combining very fast (10 ms) NOx measurement with differential GPS accurate to 1 cm allows these emissions to be resolved to a distance of less than 10 cm (worst-case-dependent on vehicle speed). The results show that acceleration events for the vehicles play a significant part in their total NOx emissions. In addition, standard events such as a speed bump and a bus stop are analysed. The temperature of any aftertreatment (catalytic converter) to reduce NOx emissions is also observed to be of substantial significance. At idle, the passenger car was observed to near-double its NOx emissions when the air conditioning was switched on. Finally, the real driving conditions are compared to the legislative compliance cycles for the certification of the buses, and those results used to further understand the observed NOx emissions.