重型柴油车排放控制的下一个挑战:从NOx到N2O
Hongfei Chen1, Liqiang He2, Liang Ji2
1School of Ecology and Environment, Zhengzhou University, Zhengzhou 450001, China.
Environmental pollution (Barking, Essex : 1987)
|November 8, 2024
概括
重型柴油车的双选择性催化减排 (SCR) 系统比单个SCR系统排放的氧化 (N2O) 大得多. 这种强大的温室气体排放受到温度,负载和高度的影响,影响碳减排战略.
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:
- 车辆的排放,特别是温室气体,是一个全球性的问题.
- 更严格的氧化 (NOx) 排放标准需要先进的排放控制系统,例如重型柴油车辆的双选择性催化减排 (SCR).
- 氧化物 (N2O) 是一种强大的温室气体,是SCR系统的副产品,但其来自HDDV的排放特征尚不清楚.
研究的目的:
- 调查和量化装有单一和双SCR系统的HDDV的氧化 (N2O) 排放.
- 分析各种运营和环境因素对N2O排放的影响.
- 为未来的温室气体限制设定提供关键数据,并为HDDVs的碳减排战略提供信息.
主要方法:
- 利用重型底盘动力表来模拟现实世界的驾驶条件.
- 经过测试的HDDV配备了单个和双 SCR 系统.
- 不同的环境温度 (-10°C至40°C),高度 (0m至3000m) 和载荷质量 (无载荷,半载荷,满载荷).
主要成果:
- 制动特定的N2O排放量 (EFb) 在单个SCR系统中为76.28-269.65 mg/kWh,在双 SCR系统中为147.50-170.22 mg/kWh.
- 在所有测试条件下,双 SCR 系统的 N2O 排放量是 NOx 的 6-22 倍.
- 单个SCR系统的N2O排放量随着环境温度和负载的增加而显著增加,并随着海拔的增加而减少. 双SCR系统显示的变化不那么显著.
结论:
- 双SCR系统虽然有效降低NOx,但与单个SCR系统相比,可以导致N2O排放量大幅增加.
- 环境因素 (温度,高度) 和运行条件 (负载) 显著影响N2O排放,特别是在单个SCR系统中.
- 调查结果强调,在制定未来的排放标准和对HDDV的碳减排战略时,需要考虑N2O排放.
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