WLTC工况下颗粒物排放特性研究及优化

Characteristics Study and Optimization of Particulate Emission Based on WLTC

以全球轻型汽车测试循环(WLTC)为基础,研究了不同阶段颗粒物数量的分布特性,对发动机原始颗粒物排放进行优化,并在整车WLTC排放测试中进行了验证和进一步优化。结果表明:喷油时刻、喷油压力、喷油比例、喷油次数等因素对涡轮增压直喷(GDIT)发动机的颗粒物排放产生影响;通过发动机原始排放优化,以及在不同工况下使用多次喷射等策略能够大幅降低颗粒物排放量,满足排放法规限值要求;随着行驶里程的增加,WLTC测试颗粒物排放呈下降趋势。

Based on WLTC,distribution characteristics of particles amount in different phases are studied,engine primary particles are optimied,verification and further optimization are conducted in vehicle WLTC emission test.The results show that factors,i.e.injection timing,injection pressure injection proportion,and injection times affect particles emission of GDIT engine;by optimizing engine primary emission,and applying strategies including multiple injection under different conditions particle emissions can be reduced remarkably,the emission regulation requirement can be satisfied;with the increase of driving mileage,emissions in WLTC tend to decline.