State Key Joint Laboratory of ESPC, State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, School of Environment, Tsinghua University, Beijing 100084, China.
Key Laboratory of Pollution Control and Resource Recycling of Fujian Province, College of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007, China.
J Hazard Mater. 2022 Aug 5;435:128979. doi: 10.1016/j.jhazmat.2022.128979. Epub 2022 Apr 20.
Identification of air toxics emitted from light-duty gasoline vehicles (LDGVs) is expected to better protect human health. Here, the volatile organic compound (VOC) and intermediate VOC (IVOC) emissions in the high-emitted start stages were measured on a chassis dynamometer under normal and extreme temperatures for China 6 LDGVs. Low temperature enhanced the emission rates (ERs) of both VOCs and IVOCs. The VOC ERs were averaged 5.19 ± 2.74 times higher when the temperature dropped from 23 °C to 0 °C, and IVOCs were less sensitive to temperature change with an enlargement of 2.27 ± 0.19 times. Aromatics (46.75 ± 2.83%) and alkanes (18.46 ± 1.21%) dominated the cold start VOC emissions under normal temperature, which was quite different from hot running emission profiles. From the perspective of emission inventories, changes in the speciated composition of VOCs and IVOCs were less important than that in the actual magnitude of ERs under cold conditions. However, changes in the ERs and emission profiles were equally important at high temperatures. Furthermore, high time-resolved measurements revealed that low temperature enhanced both the emission peak and peak duration of fuel components and incomplete combustion products during cold start, while high temperature only increased the peak concentration of fuel components.
鉴定轻型汽油车（LDGV）排放的空气毒物有望更好地保护人类健康。在这里，在底盘测功机上测量了中国 6 辆 LDGV 在正常和极端温度下的高排放启动阶段的挥发性有机化合物（VOC）和中间挥发性有机化合物（IVOC）排放。低温会提高 VOC 和 IVOC 的排放率（ER）。当温度从 23°C 降至 0°C 时，VOC 的 ER 平均增加了 5.19±2.74 倍，而 IVOC 对温度变化的敏感性较低，增幅为 2.27±0.19 倍。在正常温度下，冷启动 VOC 排放中芳烃（46.75±2.83%）和烷烃（18.46±1.21%）占主导地位，这与热运行排放特征有很大不同。从排放清单的角度来看，在低温下，VOC 和 IVOC 谱组成的变化不如 ER 实际幅度的变化重要。然而，在高温下，ER 和排放特征的变化同样重要。此外，高时间分辨测量表明，低温会增强冷启动时燃料成分和不完全燃烧产物的排放峰值和峰值持续时间，而高温只会增加燃料成分的峰值浓度。
