缸内直喷汽油车颗粒物数量及可溶性有机组分排放特性

以一辆国V排放缸内直喷汽油车为研究对象，试验研究了NEDC、FTP-75和WLTC对该车颗粒物质量、23nm~2.5μm固态颗粒物数量、5.6~560nm超细颗粒数量及粒径分布、颗粒物有机组分的影响.结果表明：NEDC、FTP-75、WLTC颗粒粒径分布基本相同，均呈对数双峰分布，在9nm和60nm两个粒径处出现峰值；5.6~23nm颗粒物数量排放占5.6~560nm颗粒物数量的43.1%~57.7%；与NEDC比较，加减速比例高、瞬态性强的FTP-75、WLTC循环的颗粒物质量、23nm~2.5μm固态颗粒数量、5.6~560nm颗粒数量排放增大；缸内直喷汽油车的颗粒物可溶性有机物组分占颗粒物的20.5%~27.9%，可溶性有机物主要为C16和C18的脂肪酸、C20~C29烷径和5环以上的高分子量多环芳烃，测试循环对颗粒SOF排放及组分产生影响，瞬态性强的FTP-75、WLTC的PAHs比例增加.

Particle number and soluble organic fraction characteristics of particle emissions from gasoline direct injection vehicle

The emission characteristics of particulate mass, particle number, particle size distribution and the composition of soluble organic fractions from a stoichiometric gasoline direct injection (GDI) vehicle certified to China V emission standard over different test cycles i.e., New European driving cycle (NEDC), worldwide harmonized light vehicle test cycle (WLTC) and USA federal test procedure-75 (FTP-75)) were investigated. The results showed that particle size distribution over NEDC, FTP-75, and WLTC was basically the same, with a logarithmic bimodal distribution, when the peaks occurred at 9nm and 60nm; 5.6~23nm particulate matter emissions occupy 43.1%~57.7% of the 5.6~560nm particulate matter. Compared with NEDC, particulate mass, 23nm~2.5μm solid particle number and 5.6~560nm particle number emissions of FTP-75 and WLTC increased due to their higher deceleration and acceleration ratios and the stronger transient performance; soluble organic fraction accounted for 20.5%~27.9% of the particulate matter emitted from gasoline direct injection vehicle. The soluble organic fraction mainly contained C16 and C18 fatty acids, C20~C29 alkane diameter and high molecular weight polycyclic aromatic hydrocarbons with 5 rings or more, while different test cycles showed diverse impact on SOF emission and its components, FTP-75 and WLTC with stronger transient performance revealed higher proportion of PAHs.