不同燃料汽车排放超细微粒特性的实验研究

利用底盘测功机和粒径范围0.015~0.7 m的扫描迁移微粒测定仪 SMPS,对柴油出租车、柴油小巴车、汽油私家车和LPG出租车进行了高低怠速和10 kmh-1到70 kmh-1不同运行工况条件下排放的超细微粒粒径分布试验研究。研究表明：不同燃料车在不同工况条件下排放的细微粒尤其是超细微粒特征呈现显著的不同。柴油车贡献更多的是粒径在30～150 nm的核模态和积聚模态微粒,LPG和汽油车贡献更多的是15～30 nm的核模态微粒。总体上,柴油车比汽油车和LPG燃料车排放更多的微粒数和微粒质量;柴油车、汽油车和LPG车排放的SMPS可测细微粒总数、总质量分别约为(0.3~3.6) 108 cm-3,0.03~0.6 gcm-3;2.3×104~1.2×107 cm-3,8×10-5~0.1 gcm-3; 8.2×103~8.8×106 cm-3, 1.7×10-5~0.09 gcm-3;对所有测试汽车,在低怠速和低行驶速度时,排放微粒数少,在高怠速和高行驶速度时,排放微粒数多。

Experimental Study on Ultrafine Particle Characteristics Exhausted from Various Fuelled Vehicles

The fine particle size distribution characteristics obtained from a diesel taxi, a diesel light bus, a gasoline private car and a liquefied petroleum gas (LPG) fuelled taxi were carried out on a chassis dynamometer system. The measurements were performed at different driving modes, i.e. , with low and high idling and from 10 kmxh(-1) to 70 kmxh(-1), 4 cruise operations using the instrument SMPS for collecting particles of 0.015-0.7microm diameter in range. It was found that different fuelled vehicles and different driving modes characterize considerable differences in size number and mass concentration distributions. Diesel vehicles contribute much more nuclei and accumulation mode particles of 30 - 150 nm, while LPG and gasoline fuelled vehicles exhaust much more nuclei mode particles of 15-30 nm. Overall, diesel-fuelled vehicles exhaust much more particles number and mass than gasoline and LPG fuelled vehicles; In the present study, diesel vehicles exhaust the ranges of total SMPS particle number, mass concentration with (0.3-3.6) x 10(8) number x cm(-3), 0.03 - 0.6 microg cm(- 3) respectively, and gasoline and LPG fuelled vehicles exhaust 2.3 x 10(4) - 1.2 x 10(7) number x cm(-3), 8 x 10(-5)-0.1 microgxcm(-3); 8.2 x 10(3)8.8 x 10(6) number x cm(-3), 1.7 x 10(-5) -0.09 microg x cm(-3), respectively; For all types of vehicles, the particle number and mass concentrations are small at low-idle and low-speed-driving modes, and are large at high-idle and high-speed-driving modes. They generally increase with the vehicle speed increasing from 10 to 70 kmx h(-1).