车辆排放的复杂温度依赖:来自全球元分析的证据
Xinhui Liu1, Yunjing Wang2, Rencheng Zhu3
1State Environmental Protection Key Laboratory of Vehicle Emission Control and Simulation, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; School of Environment, Beijing Normal University, Beijing, 100875, China.
Environmental research
|August 21, 2023
概括
低环境温度显著增加车辆的废气排放,排放因子的比率从1.14到3.84. 未来的排放标准必须解决这些寒冷天气的影响.
科学领域:
- 环境科学 环境科学
- 汽车工程 汽车工程
- 大气化学 大气化学
背景情况:
- 汽车废气排放是空气污染的主要来源.
- 低环境温度对这些排放的影响很大,但往往受到监管不足.
- 了解这些影响对于制定有效的环境政策至关重要.
研究的目的:
- 用全球元分析量化低环境温度对车辆废气排放的影响.
- 为了比较低环境温度 (LATs) 和温暖环境温度 (WATs) 的排放因子.
- 确定特定的污染物趋势和影响因素,如发动机类型和排放控制技术.
主要方法:
- 进行了对1795个观测结果的全球元分析,比较了LAT (-18°C至-7°C) 和WAT (20°C至30°C) 的排放.
- 对11种排气污染物进行量化平均差异 (MDt).
- 利用局部加权回归来分析排气温度概况,并使用油基发动机的子组分析.
主要成果:
- 低环境温度显著增加车辆排放,排放因子比率 (EFLAT/EFWAT) 在1.14和3.84之间.
- 柴油发动机在LAT时显示NOx排放量大幅增加 (MDt [NOx]为12.42-15.10毫克/公里)
- 在冷启动过程中,颗粒物排放量增加了0.22-1.41毫克km-1·k-1;然而,颗粒物过器减少了这种影响,但增加了NOx.
- 汽油车在LAT中排放的颗粒物更多,而柴油车则呈现相反的趋势.
结论:
- 低环境温度显著提高车辆的排放量,需要监管部门的注意.
- 未来的车辆排放标准应该为寒冷天气条件设置更严格的限制.
- 排气管排放控制技术,如颗粒过器,在不同温度下对不同污染物产生复杂的影响.
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