关键词: 动力机械工程, 汽油车, 排放, 微粒, 电子低压冲击仪

Abstract:

The characteristics of particulate emissions from gasoline vehicles complying to Euro 3 or Euro 4 emission standards with port fuel injection(PFI) engine or gasoline direct injection(GDI) engine were investigated under cold start and hot start conditions by means of an electrical lowpressure impactor(ELPI) and an exhaust emission measuring system for the lightduty vehicle on a chassis dynamometer. The results show that the particulates emission from a Euro 3 PFI gasoline vehicle at cold start is characterized by higher particle number concentration and larger particle size, and that from a Euro 4 GDI vehicle is characterized by the highest particle area and mass concentrations. The particle number concentrations exhausted from both vehicles are in the same magnitude order of 106, and the particulates emission at hot start condition is 40% lower than that at cold start condition. More than 90% of the particle size concentration is distributed in the size range of 0.007~0.378 μm, more than 90% of the particle area concentration in the range of 0.055~9.83 μm, and 99% of the particle mass concentration in the range of 0.091~9.83 μm. Both the results calculated by ELPI and measured by particulate measuring system show that the particulates mass emissions from PFI gasoline vehicle under EUDC driving cycle are higher than those under ECE driving cycle. Results also show the particulates mass calculated by ELPI is different from that measured by standard measuring system.

Key words: power machinery and engineering, gasoline vehicle, emission, particulate, electrical low-pressure impactor(ELPI)