中文摘要：

针对高压共轨柴油机,研究了不同喷油压力和主预喷间隔角度下,正丁醇/柴油混合燃料对压燃式发动机燃烧及颗粒物排放的影响规律.结果表明：柴油中掺混正丁醇后,滞燃期延长,预混合燃烧量增加,燃烧持续期缩短,碳烟及颗粒物排放大幅降低,微粒粒径减小,核态微粒比例增加,NOx排放变化不大.喷油压力由80MPa提高至100MPa,混合燃料消光烟度明显降低,继续提高喷油压力不但对碳烟排放降低作用减弱,还会进一步造成NOx排放增加,同时核态微粒数量明显增加.主预喷间隔角度过小会造成主预喷燃油燃烧重叠,使碳烟排放增加,随主预喷间隔角度增加,总微粒、积聚态微粒数量浓度明显降低,核态微粒比例增加,当主预喷间隔角度增大到20°CA后,继续增大主预喷间隔角度对碳烟排放降低作用不明显.

英文摘要：

The effects of combustion and particulate matter emissions under different fuel injection pressures and timing interval between pilot and main injection were studied on a high pressure common rail diesel engine fueled with n- butanol/diesel blends. Results show that the addition of butanol in traditional diesel leads to an increase in the ignition delay and in the amount of premixed combustion, and to a reduction in the combustion duration. Soot and particulate emissions are also significantly reduced but the proportion of nucleation particle mode is increased. NOx emissions are little varied with the increase of butanol amount. When the injection pressure increases from 80 MPa to 100 MPa, the smoke opacity of the mixed fuel reduces significantly. Further increase of the injection pressure gives a less reduction of soot emissions but an obvious increase of NOx emissions. Meanwhile, the particle number of nucleation mode increases more significantly. Too small timing interval between pilot and main injection causes a remarkable increase in soot emissions as the fuel from pilot injection bums together with the fuel from the main injection. With the increase of the timing interval between pilot and main injection, both particle numbers of total particulates and accumulation mode decrease and percentage of nucleation particle mode increases. Further increasing the timing interval between pilot and main injection after 20° CA, the reduction trend of soot emissions becomes less.