后喷策略下喷油压力对柴油机缸内颗粒物粒径分布和形貌特征的影响  

Effects of Post-Injection Strategy and Injection Pressure on Particle Size Distribution and Morphology

作　　者：王光耀 范晨阳 吕刚[1] 宋崇林[1] Wang Guangyao,Fan Chenyang,Lü Gang,Song Chonglin(State Key Laboratory of Engines,Tianjin University,Tianjin 300072,Chin)

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072

出　　处：《燃烧科学与技术》2018年第3期262-269,共8页Journal of Combustion Science and Technology

基　　金：国家重点基础研究发展计划(973计划)资助项目(2013CB228502);天津市应用基础与前沿技术研究计划资助项目(13JCZDJC35800)

摘　　要：基于全气缸取样平台,运用称重法、发动机粒数粒径测试分析仪(EEPS)和透射电子显微镜(TEM)等手段对采集到的燃烧过程中的颗粒物进行分析处理,研究高压共轨柴油机在后喷策略下,喷油压力对于柴油机燃烧过程中颗粒物粒径分布和形貌特征的影响.实验结果表明:后喷的加入会延长燃烧持续期;当喷油压力由100,MPa上升到120,MPa时,缸内燃烧温度压力升高、燃烧始点提前,预混燃烧在整个燃烧过程中所占比例增大,生成颗粒物粒径分布特征由双峰变为单峰,粒子数密度和碳烟质量浓度均降低,除此之外增大喷油压力还会导致燃烧过程中生成的链状颗粒减少,分形维数增大,同时减小后喷对于燃烧持续期的影响.Based on the total engine sampling system,the research focused on the pressure effects on particle size distribution and morphology with different injection strategies in diesel engine combustion.Weighing method engine exhaust emission particle size spectrometer（EEPS）and transmission electron microscopy（TEM）were used to analyze the particles collected from combustion process.It was revealed that the addition of post-injection would lengthen the combustion duration.As inject pressure rose from 100,MPa to 120,MPa,both the in-cylinder pressure and temperature increased.In the meantime,the start of combustion advanced and the percentage of premixed combustion increased.Besides,there was an obvious change of size distribution from bi-modal to uni-modal with a reduction of particle concentration and soot mass concentration.What’s more,with the increase of injection pressure,the effects of post-injection on combustion duration was weakened and fewer chain-like particles were generated which indicating the enlargement of fractal dimensions.

关 键 词：全气缸取样平台 后喷 喷油压力 颗粒物粒径分布 形貌特征 

分 类 号：TK488.21[动力工程及工程热物理—动力机械及工程]