Energy Engineering Department, Sharif University of Technology, Tehran, Iran.
Mechanical Engineering Department, Sharif University of Technology, Tehran, Iran.
Environ Pollut. 2021 Oct 1;286:117396. doi: 10.1016/j.envpol.2021.117396. Epub 2021 May 18.
Urban transportation is one of the leading causes of air pollution in big cities. In-use emissions of vehicles are higher than the emission control certification levels. The current study uses a roadside remote sensing emission monitoring campaign to investigate (a) fraction of high emitters in the light-duty vehicle (LDV) fleet and their contributions to the total emissions, (b) emission inspection (I/M) programs' effectiveness, and (c) alternate fuel (natural gas) encouragement policy. LDVs consist of passenger or freight transport vehicles with four wheels equivalent to classes M1 and N1 of European union vehicle classifications. The motivation is to assess the current emission inspection program's success rate and study the impact of the increased natural gas vehicle market share policy. It is also meant to present and validate remote sensing as a possible backup method to the current I/M program. The emission remote sensing campaign was conducted to measure emissions of CO, HC, and NO of the LDV fleet. Fleet age, engine size, and fuel type (gasoline or natural gas) were extracted and correlated with emissions. It was found that CO and HC emissions are five times higher for cars more than fifteen years old of age compared to those less than five years old. Analyses of high-emitters showed that almost 20% of the fleet were high-emitters and responsible for roughly half of CO, HC, and NO emissions. The correlation between the I/M program and the remote sensing to identify high-emitters was weak. Which indicates the need for an improved I/M program. It shows that even a limited remote sensing campaign is beneficial as a complementary monitoring tool to the I/M program. The study showed the same fraction of high-emitters in natural gas (methane) vehicles, despite the national policies to increase natural gas vehicle fraction in the market for reduced emissions.
城市交通是大城市空气污染的主要原因之一。车辆的在用排放高于排放控制认证水平。本研究利用路边远程遥感排放监测活动来调查(a)轻型车（LDV）车队中高排放者的比例及其对总排放量的贡献，(b)排放检验（I/M）计划的有效性，以及(c)替代燃料（天然气）鼓励政策。LDV 由具有四个轮子的乘用车或货运车辆组成，相当于欧洲联盟车辆分类的 M1 和 N1 类。其动机是评估当前排放检验计划的成功率，并研究增加天然气汽车市场份额政策的影响。它还旨在展示和验证遥感作为当前 I/M 计划的可能替代方法。排放遥感活动旨在测量 LDV 车队的 CO、HC 和 NO 排放。提取车队年龄、发动机大小和燃料类型（汽油或天然气），并与排放相关联。结果发现，15 岁以上的汽车的 CO 和 HC 排放比 5 岁以下的汽车高五倍。对高排放者的分析表明，近 20%的车队是高排放者，对 CO、HC 和 NO 的排放负有大约一半的责任。I/M 计划和遥感识别高排放者之间的相关性较弱。这表明需要改进 I/M 计划。这表明，即使是有限的遥感活动也可以作为 I/M 计划的补充监测工具有益。该研究表明，即使在国家政策旨在增加市场上天然气汽车的比例以减少排放的情况下，天然气（甲烷）车辆中的高排放者比例也相同。
Zotero 插件