Institute for Transport Studies, University of Leeds, Leeds LS2 9JT, UK.
Sci Total Environ. 2022 Jun 1;823:153699. doi: 10.1016/j.scitotenv.2022.153699. Epub 2022 Feb 7.
Vehicle emission remote sensing devices have been widely used for monitoring and assessing the real-world emission performance of vehicles. They are also well-suited to identify candidate high emitting vehicles as remote sensing surveys measure the on-road, real-driving emissions (RDE) of a high proportion of the operational vehicle fleet passing through a testing site. This study uses the Gumbel distribution to characterize the fuel-specific NO emission rates (g·kg) from diesel vans (formally referred to as light commercial vehicles or LCVs) and screen candidate high emitting vehicles. Van emission trends of four European countries (Belgium, Sweden, Switzerland and the UK) from Euro 3 to Euro 6a/b have been studied, and the impact of road grade on candidate Euro 6a/b high-emitters is also evaluated. The measurements of Euro 6a/b fleets from four countries are pooled together, and a consistent 4% of candidate high-emitters are found in both class II and class III Euro 6a/b vans, accounting for an estimated 24% and 21% total NO emissions respectively. The pooled four country data is differentiated by vehicle models and manufacture groups. Engine downsizing of Euro 6a/b class II vans is suspected to worsen the emission performance when vehicles are driven under high engine load. The VW Group is found to be the manufacture with cleanest NO emission performance in the Euro 6a/b fleets. By distinguishing high-emitters from normally behaving vehicles, a more robust description of fleet behaviour can be provided and high-emitting vehicles targeted for further testing by plume chasing or in an inspection garage. If the vehicle is found to have a faulty, deteriorated or tampered emission after-treatment system, the periodic vehicle inspection safety and environmental performance certificate could be revoked.
车辆排放遥测设备已广泛用于监测和评估车辆的实际排放性能。它们也非常适合识别候选高排放车辆，因为遥测调查测量了通过测试站点的运营车辆中很大一部分的道路实际行驶排放（RDE）。本研究使用 Gumbel 分布来描述柴油厢式车（正式称为轻型商用车或 LCV）的燃料特定 NO 排放率（g·kg），并筛选候选高排放车辆。研究了四个欧洲国家（比利时、瑞典、瑞士和英国）从欧 3 到欧 6a/b 的厢式车排放趋势，还评估了道路坡度对候选欧 6a/b 高排放车辆的影响。将四个国家的欧 6a/b 车队的测量值汇总在一起，在 II 类和 III 类欧 6a/b 厢式车中均发现了一致的 4%的候选高排放车辆，分别占估计的总 NO 排放量的 24%和 21%。汇总的四个国家的数据按车辆型号和制造集团进行了区分。怀疑欧 6a/b 类 II 厢式车的发动机缩小化会在车辆在高发动机负荷下行驶时恶化排放性能。发现大众汽车集团在欧 6a/b 车队中具有最清洁的 NO 排放性能。通过将高排放车辆与正常行驶车辆区分开来，可以更准确地描述车队的行为，并针对高排放车辆进行进一步的测试，例如采用尾迹追逐或在检验车库中进行测试。如果发现车辆的后处理系统存在故障、恶化或篡改，则可以吊销定期车辆检验安全和环境性能证书。
