中文摘要：

对高压共轨柴油机稳态与瞬态工况下的微粒排放粒度分布进行了实验研究。结果表明,高压共轨柴油机排气微粒粒径大部分处于250nm以内,超细微粒占绝大多数。稳态工况下,随负荷增加微粒数量浓度分布曲线峰值逐渐向大粒径方向移动,大负荷工况下峰值开始进入积聚态区域。在瞬态工况下,微粒粒度分布曲线呈单峰形态,平均数量浓度分布峰值位于核态区域,峰值区间为15~25nm。在同一负荷（当量比0.5）下,稳态工况的核态微粒的数量、表面积和体积浓度均较稳态工况大幅度上升;随着瞬变率的增大,核态微粒数量浓度增加而积聚态微粒数量浓度下降。

英文摘要：

An experimental study is carried out on the particle size distribution of a high-pressure commonrail diesel engine in both steady-state and transient conditions. The results show that a large proportion of diesel particle emission have a size below 250 nm,the majority of which are ultrafine particles. In steady-state conditions,with the increase of engine load,the peak of particle number concentration distribution curve move toward the large size direction,and starts to enter the region of the accumulation mode at high load. In transient conditions,particle size distribution curve shows a single peak pattern,the peaks of average number concentration distribution curve fall into the interval of 15 nm to 25 nm in the nucleation mode region. At same load with a stoichiometric ratio of 0. 5,the number,surface area and volume concentrations of particles in transient conditions are all higher than those in steady-state conditions,and with the increase of transient rate,the number concentration of nucleation particles rises while that of accumulation particle falls.