中文摘要：

为了进一步减少甲醇掺烧后的柴油机颗粒物排放,在一台由增压中冷的高压共轨柴油机改造成的柴油甲醇组合燃烧（DMCC—diesel/methanol compound combustion）发动机上详细研究了柴油喷射时刻对两种燃料共燃时的颗粒物生成及其排放的影响.试验工况选择重型柴油机常用的A50工况.试验结果表明,当柴油在上止点后喷射时,颗粒物排放的数量浓度随着甲醇替代率的增加而减少,当上止点前喷射时,颗粒物的数量浓度先减少后增加.随着喷射时刻的提前,颗粒中超细颗粒所占比例增大.随着喷射时刻的推迟,甲醇替代率降低颗粒物质量浓度的作用增强,同时甲醇替代率降低颗粒物几何平均直径的作用减弱.

英文摘要：

In order to reduce particulate matter emissions,the effects of injection timing on PM emissions from a diesel/methanol compound combustion（DMCC） engine modified from a turbocharged intercooled common-rail fuel injection diesel were investigated.Testing condition was chosen at 50% of load and 1340 r·min-1of speed,which is mostly used by heavy duty diesel engines.The results showed that when diesel fuel was injected after the TDC,the particle number concentration decreased with increasing methanol substitution percent.In comparison,PM number concentration reduced first and then increased when diesel fuel was injected before the TDC.The number of ultrafine particle increased as the injection timing was advanced.With the delay of the injection timing,methanol substitution percent had a significant effect on decreasing particle mass concentration and it had a slight effect on reducing geometric mean diameter of particle.