汽车工程
汽車工程
기차공정
AUTOMOTIVE ENGINEERING
2014年
6期
678-682
,共5页
柴油机%柴油%汽油%燃料特性%低温燃烧
柴油機%柴油%汽油%燃料特性%低溫燃燒
시유궤%시유%기유%연료특성%저온연소
diesel engine%diesel%gasoline%fuel properties%low-temperature combustion
通过对柴油机燃用纯柴油、20%和40%汽油(体积比)3种燃料时的燃烧和排放特性的对比试验,研究了燃料特性对柴油机低温燃烧的影响。结果表明,随着汽油比例的升高,滞燃期延长,低氧浓度时更加明显,这也导致了压升率的升高和“丢火”临界点向高氧浓度移动,但提前喷油时刻对此有一定补偿作用。汽油比例对NOx、CO和THC排放影响较小,但在低氧浓度区域,较大的汽油比例可以大幅降低碳烟排放。氧浓度大约低于16%以后,CO和TCH排放急剧上升;碳烟也进入高峰区,但提前喷油时刻可有效降低排放水平;而NOx 正好相反,氧浓度大约高于16%后,NOx 排放迅速升高,而只有延缓喷油时刻,才能改善其排放。
通過對柴油機燃用純柴油、20%和40%汽油(體積比)3種燃料時的燃燒和排放特性的對比試驗,研究瞭燃料特性對柴油機低溫燃燒的影響。結果錶明,隨著汽油比例的升高,滯燃期延長,低氧濃度時更加明顯,這也導緻瞭壓升率的升高和“丟火”臨界點嚮高氧濃度移動,但提前噴油時刻對此有一定補償作用。汽油比例對NOx、CO和THC排放影響較小,但在低氧濃度區域,較大的汽油比例可以大幅降低碳煙排放。氧濃度大約低于16%以後,CO和TCH排放急劇上升;碳煙也進入高峰區,但提前噴油時刻可有效降低排放水平;而NOx 正好相反,氧濃度大約高于16%後,NOx 排放迅速升高,而隻有延緩噴油時刻,纔能改善其排放。
통과대시유궤연용순시유、20%화40%기유(체적비)3충연료시적연소화배방특성적대비시험,연구료연료특성대시유궤저온연소적영향。결과표명,수착기유비례적승고,체연기연장,저양농도시경가명현,저야도치료압승솔적승고화“주화”림계점향고양농도이동,단제전분유시각대차유일정보상작용。기유비례대NOx、CO화THC배방영향교소,단재저양농도구역,교대적기유비례가이대폭강저탄연배방。양농도대약저우16%이후,CO화TCH배방급극상승;탄연야진입고봉구,단제전분유시각가유효강저배방수평;이NOx 정호상반,양농도대약고우16%후,NOx 배방신속승고,이지유연완분유시각,재능개선기배방。
Through the comparative testing on the combustion and emission characteristics of diesel engine fueled with pure diesel and 20% and 40% ( volume fraction) gasoline blend fuels, the effects of fuel properties on the low temperature combustion in diesel engine are investigated. The results show that with the proportion of gaso-line increasing, ignition delay prolongs, especially at low oxygen concentration. This also leads to higher pressure rise rate and the shift of misfire limit toward higher low oxygen concentration, but for which advancing fuel injection timing may have certain compensation. Gasoline proportion has little effects on NOx , CO and THC emissions, but at low oxygen concentration range higher gasoline proportion can greatly reduce soot emission. When oxygen concentra-tion is lower than around 16% the emissions of CO and THC increase sharply and soot emission also enters the‘bump’ region, but advancing fuel injection timing can effectively lower their emission level;while it is just the op-posite for NOx , when oxygen concentration is higher than around 16 % its emission obviously rises and only retar-ding the injection timing can its emission improve.