摘要
在一台单缸风冷柴油机上,采用不同体积分数的富氮和富氧进气,对变组分进气工质的燃烧和排放特性规律进行了归纳分析.结果表明:从富氮状态开始,随着进气工质中O2体积分数的增加,着火延迟期缩短,压力升高率峰值和压力峰值增加,富氮造成的着火延迟效应比富氧造成的着火提前效应更显著,各排放物参数的变化率随进气O2体积分数的变化率均呈现二次多项式关系;在富氧阶段,进气O2体积分数增加降低HC,CO和排气烟度的效果渐趋缓慢,但在富氮阶段,随着富氮程度加大,HC,CO和排气烟度却急剧恶化,而NOx排放则在富氧阶段急剧上升而在富氮阶段下降缓慢;大负荷工况下受供氧制约,进气O2体积分数变化对CO和烟度排放变化率的影响作用增强,而由于小负荷工况下进气O2体积分数变化对缸内温度影响更显著,造成HC和NOx排放变化率更敏感.
Charged with variable oxygen and nitrogen components as intake air, the combustion features and emission regulations of a diesel engine were analyzed. The results show that the effect of enriched nitrogen on prolonging ignition delay appears more evidently than that of enriched oxygen on shortening ignition delay. The increasing rates of all emissions show second polynomial relationship with the increasing rate of intake oxygen. From the state of nitrogen enrichment, with the increasing of intake oxygen content, the ignition delay is decreased, and the cylinder peak pressure and the maximum rate of pressure rise are increased. At the state of oxygen enrichment, the effects of oxygen increasing on the reduction of HC, CO and smoke are weakened gradually. At the state of nitrogen enrichment, HC, CO and smoke are worsened sharply. NOx emissions behave a rapid rise at oxygen enrichment state but with slow decline at nitrogen enrichment state. Restricted by oxygen providing, the influence of intake oxygen volume fraction variation on CO and smoke emissions is enhanced at large load. At small load, the intake oxygen volume fraction has marked impact on in-cylinder temperature, which leads to more sensitivities of HC and NOx emission.
出处
《江苏大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2016年第1期12-17,共6页
Journal of Jiangsu University：Natural Science Edition
基金
国家自然科学基金资助项目(51376095
51506101)
江苏省环保科研课题项目(2014049)
关键词
柴油机
变组分进气
富氧
富氮
燃烧
排放
diesel engine
variable intake air
enriched oxygen
enriched nitrogen
combustion
emission
