后喷策略对柴油机排气污染物的影响  

Influence of Post-Injection Strategy on the Exhaust Emissions from a HSDI Diesel Engine

作　　者：杨新乐[1] 乔约翰 李浩[2] 吕刚[2] 

机构地区：[1]辽宁工程技术大学机械工程学院,阜新123000 [2]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》2017年第3期212-216,共5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);国家自然科学基金资助项目(51574136)

摘　　要：在一台电控高压共轨柴油机上,研究了后喷策略对柴油机排放的影响.实验工作在恒定工况下进行,选择不同主后喷间隔及后喷率,测量了CO、总碳氢化合物、氮氧化物、颗粒物排放的排放值;同时,还考察了排气碳烟的表观活化能和石墨化程度.实验结果表明:随着主后喷间隔及后喷率增加,CO和总碳氢化合物呈上升趋势,而NOx呈下降趋势;后喷率为12%,和20%,时,无论过大或过小的主后喷间隔,颗粒物排放均有明显的增加;后喷率为4%,时,随着主后喷间隔的增加,颗粒物的排放量增加.后喷对碳烟微粒的活化能有较强的影响,而碳烟石墨化程度的变化也证明了此结果.A four-cylinder,direct-injection diesel engine equipped with a high-pressure,common-rail fuel injec-tion system was tested under a constant engine operating mode to investigate the effect of post-injection strategy on pollutant emissions. Characteristics of exhaust pollutants were measured and evaluated for different main-post in-tervals（MPIs）and post-injection rates（PIRs）. Measurements included emissions of carbon monoxide（CO）,total hydrocarbons（THC）,nitrogen oxides（NOx）and particulate matter（PM）,the reactivity and graphitization degree of soot particles. Increasing the MPI or PIR increased the emissions of CO and THC but decreased those of NOx. At both low and high MPI values,higher PM emissions and particle number concentrations were observed for 12% and 20% PIRs. At 4% PIR,PM emissions and particle number concentration increased with increasing MPI. Post injection significantly influenced the reactivity of emitted soot particles,as was evidenced by changes in the graphitization degree of soot.

关 键 词：柴油机 主后喷间隔 后喷率 污染物排放 碳烟氧化活性 

分 类 号：TK421.5[动力工程及工程热物理—动力机械及工程]