怠速起停对汽油车油耗及颗粒数量排放的影响

以一辆配置怠速起停系统的国V缸内直喷汽油车为研究对象，使用底盘测功机试验系统、全流稀释采样系统和固态颗粒计数系统，试验研究怠速起停对缸内直喷汽油车油耗与颗粒数量排放的影响，并分析起动温度、试验循环等因素的影响.结果表明，NEDC循环车辆冷机起动时，车辆怠速起停系统开启的百公里油耗降低了5.1%，颗粒数量排放升高了16.7%；车辆热机起动，怠速起停开启产生的百公里油耗降幅增大到7.3%，颗粒数量排放升幅减小至9.3%；WLTC循环热机起动，车辆怠速起停系统开启的百公里油耗降幅减少到1.7%，颗粒数量排放升幅减少到6.2%.怠速起停有利于降低汽车的百公里油耗，但不利于缸内直喷汽油车颗粒数量排放的控制.

Study on the effect of idle start-stop technology on fuel consumption and particle number emission of GDI vehicle

In this paper, a gasoline direct injection (GDI) vehicle certified to meet China V emission standard equipped with idle start-stop system was taken as the research object. By using the chassis dynamometer test system, the full-flow dilution sampling system and the particle number measurement system, the paper aimed to study the effect of idle start-stop system on fuel consumption and particle number emission of GDI vehicles, as well as the effect of start temperature and testing cycles. The results showed that the fuel consumption of the test GDI vehicle with idle start-stop system on decreased by 5.1% and the emission of particles number increased by 16.7% under the NEDC cold-start condition. In the case of warm-start, the fuel consumption decreased by 7.3% and the emission of particles number increased by 9.3%. Under WLTC warm-start condition, the fuel-saving effect of idle start-stop system was less notable, when fuel consumption only decreased by 1.7% and the emission of particles number also just increased by 6.2%. The idle start-stop system was beneficial to lower fuel consumption, while it was not conducive to the control of the particle number emission.