汽油轿车NEDC循环超细颗粒物排放特性

Research on NEDC Ultrafine Particle Emission Characters of a Port Fuel Injection Gasoline Car

以一辆采用电控燃油进气道多点喷射系统的桑塔纳汽油轿车为试验样车,采用排气颗粒数量及粒径分析仪EEPS,对该车NEDC循环的超细颗粒排放数量及颗粒粒径分布特性进行了试验研究.结果表明,NEDC循环中,车辆加速时排放的核模态颗粒、聚集态颗粒数量浓度均增加;车辆启动后40 s及EUDC循环高速工况(≥90 km.h-1)排放的超细颗粒数量浓度较高;NEDC循环的颗粒数量排放呈单峰对数分布,颗粒数量排放峰值的颗粒粒径集中于10～30 nm,几何平均粒径为24 nm;ECEⅠ、ECEⅡ～Ⅳ和EUDC循环,加速、减速、怠速及匀速驾驶工况的颗粒数量排放基本上呈单峰对数分布,颗粒数量排放峰值的颗粒粒径主要集中于10～30 nm,几何平均粒径集中于14～42 nm.该汽油车NEDC循环排放的超细颗粒主要以粒径小于50 nm的核模态颗粒为主.

A Santana gasoline car with multi-port fuel injection（PFI） system was used as the research prototype and an engine exhaust particle sizer（EEPS） was employed to investigate the exhaust ultrafine particle number and size distribution characters of the tested vehicle in new European driving cycle（NEDC）.The tested results showed that the vehicle＇s nuclear particle number,accumulation particle number,as well as the total particle number emission increased when the car drove in accelerated passage,and the vehicle＇s particle number emission was high during the first 40 seconds after test started and when the speed was over 90 km·h-1 in extra urban driving cycle（EUDC） in NEDC.The ultrafine particle distribution of the whole NEDC showed a single peak logarithmic distribution,with diameters of the peak particle number emission ranging from 10 nm to 30 nm,and the geometric mean diameter was 24 nm.The ultrafine particle distribution of the urban driving cycle named by the economic commission for Europe（ECE） e.g.ECEⅠ,ECEⅡ-Ⅳ,the extra urban driving cycle e.g.EUDC,and the idling,constant speed,acceleration,deceleration operation conditions of NEDC all showed a single peak logarithmic distribution,also with particle diameters of the peak particle number emission ranging from 10 nm to 30 nm,and the geometric mean diameters of different driving cycle and different driving mode were from 14 nm to 42 nm.Therefore,the ultrafine particle emissions of the tested PFI gasoline car were mainly consisted of nuclear mode particles with a diameter of less than 50 nm.