忽视的危机:低温放大了汽油汽车的粒子数排放量
Xihui Tong1, Haiguang Zhao1, Yongshuai Qu1
1Key Laboratory for Vehicle Emission Control and Simulation of Ministry of Ecology and Environment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Vehicle Emission Control Center, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
Environment international
|September 27, 2025
概括
低温显著增加了没有汽油颗粒过器 (GPF) 的汽油直接注射 (GDI) 车辆的颗粒数 (PN) 排放. 在减少这些排放方面,GPF至关重要,甚至比混合动力电动汽车技术更重要.
科学领域:
- 环境科学 环境科学
- 汽车工程 汽车工程
- 燃烧科学 燃烧科学
背景情况:
- 汽油直接喷射 (GDI) 发动机提供燃油经济性好处,但可以增加颗粒数 (PN) 排放.
- 冷环境温度对车辆排放,特别是PN的影响尚未完全理解.
- 混合动力电动汽车 (HEV) 往往被认为本质上更清洁,但它们的PN排放特性需要仔细审查.
研究的目的:
- 系统地调查轻型汽油汽车的PN排放量在广泛的温度范围内 (-7°C至40°C).
- 量化不同发动机技术 (GDI,PFI) 和后处理系统 (GPF) 对PN排放的寒冷温度惩罚效应.
- 评估汽油颗粒过器 (GPF) 的有效性,并将其与混合动力电动汽车 (HEV) 缓解策略进行比较.
主要方法:
- 在不同的环境温度下对轻型汽油车进行了60次底盘动力仪排放测试.
- 采用机械分析来了解PN排放变化的根本原因.
- 量化了HEV中等速度运行期间的排放迁移,并确定了关键的燃烧效率值.
主要成果:
- 没有GPF的GDI车辆在冷启动时的PN排放量高达23°C的热启动时的10倍.
- GPF安装显著减少了PN排放,超过了HEV辅助缓解效应.
- 没有GPF的PFI装备的HEV在23°C时排放的PN是PFI装备的ICEV与GPF的7倍,挑战了"电气化等于清洁"的概念.
- 发现了等效里程比率 (EMR) 和环境温度之间的指数相关性,即使在20°C,冷启动排放也很大.
结论:
- 证实并低估了没有GPF的GDI车辆对PN排放产生显著的"寒冷温度惩罚"影响.
- 在控制PN排放方面,GPF非常有效,与仅依赖混合化相比,提供了更优质的解决方案.
- 目前的排放法规可能存在冷启动排放的盲点,特别是GDI车辆在寒冷的气候中,需要修订法规.
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