喷油时刻和DMF掺混对柴油机PM排放特性影响  

Experiment on the Effects of Injection Timing and DMF Addition on PM Emissions in a Diesel Engine

作　　者：李松[1,2] 魏明锐[1,2] 郭冠伦[1,2] 肖合林[1,2] 孙智勇[1,2] 

机构地区：[1]武汉理工大学现代汽车零部件技术湖北省重点实验室,湖北武汉430070 [2]武汉理工大学汽车零部件技术湖北省协同创新中心,湖北武汉430070

出　　处：《内燃机学报》2018年第1期20-26,共7页Transactions of Csice

基　　金：国家自然科学基金资助项目(51276132;21377101)

摘　　要：基于一台电控高压共轨柴油机,研究了不同喷油时刻2,5-二甲基呋喃(DMF)掺混比例(质量分数分别为0、10%,和30%,)对柴油机排放颗粒物(PM)的尺寸分布、平均直径、数量浓度和质量浓度的影响.结果表明:在试验工况下,无论掺混与否,发动机PM排放均以核模态颗粒(粒径为5~50,nm)为主,其尺寸分布呈现明显的双峰结构.燃用纯柴油时,推迟喷油时刻,核模态颗粒数量先增加后减少,聚集态颗粒(粒径为50~1,000,nm)数量的变化规律不明显,PM的总数量、总质量与核模态颗粒数量变化趋势一致,PM的几何平均直径(GMD)先增加后减小;DMF掺混可以降低聚集态颗粒数量、GMD和总质量,但却增加了核模态颗粒数量和总颗粒数量.综合考虑发动机燃油经济性和PM排放性能,30%,DMF掺混比例和-10.0°,CA ATDC喷油时刻为试验工况下的最佳方案.An experimental study was conducted on a common-rail diesel engine with 2,5-dimethylfuran （DMF） addition of 0, 10% and 30% in mass respectively. The particle size distribution（PSD）, geometric mean diame- ter（GMD）, particles number and mass concentration were measured under different fuel injection timings. The re- sults show that the particles emitted by the engine are dominated by nucleation mode （NM, particle size from 5 to 50 nm）regardless of injection timing and the amount of DMF addition. The particle size distributions present bimodal structure. With the retard of injection timing, the number of NM particles is increased first and then decreases. The variation tendency of accumulation mode （AM, particle size from 50 to 1 000 nm）particles number is irregular. The variation trends of total particles number and mass are consistent with the variation tendency of the NM number. The GMD of particles rises first and then declines. The DMF addition decreases the AM particles number, GMD and total partide mass, but increases the NM number and total particle number. The optimal operation scheme for this study is obtained at a DMF addition of 30% and an injection time of-10.0° CAATDC.

关 键 词：柴油机 2 5-二甲基呋喃 颗粒物 颗粒尺寸分布 

分 类 号：TK421[动力工程及工程热物理—动力机械及工程]