摘要
在单缸发动机上研究了气口喷射低沸点、高含氧量的二甲氧基甲烷（DMM）对生物柴油发动机的燃烧和排放特性的影响．研究表明：在直喷生物柴油当量比不变的条件下增加预混合DMM的量，整个燃烧的着火时刻和放热中心时刻提前，但是扩散燃烧时间延长，放热结束时刻拖后；在预混合DMM当量比不变时，减小直喷生物柴油的当量比会使得着火延迟．此外，当预混合比例增加到某一值后会使得最大缸内燃烧压力和最大压力升高率显著增加．在排放方面，预混合DMM会使得CO和HC排放明显上升，在某一比例达到最大值，之后却随着预混合比例的增加而大幅度降低；碳烟排放总是随着预混合比例增加而显著降低，最大可以降低35％～55％；NOx的排放规律有明显不同，在各种当量下，预混合比例在20％左右可以将NOx降低35％左右，继续增加预混合比例会使得NOx降低幅度减小．
The combustion characteristics and emissions of biodiesel-fueled engines with premixed dimethoxymethane （DMM） were investigated in this paper. The results show that, for a fixed equivalence ratio of bio-diesel, the ignition timing and the central point of heat release advance, while the end point of heat release delays, with the introduction of premixed DMM. For a specific equivalence ratio of premixed DMM, the ignition timing delays while the end point of heat release advances with the decrease of biodiesel quantity. Furthermore, as the premixed ratio increases, the maximum in- cylinder gas pressure, in-cylinder gas temperature and pressure rise rate increase smoothly. When the premixed ratio rea- ches a certain value, the maximum in-cylinder pressure and pressure rise rate increase remarkably. As to the regulated e- missions, CO and HC increase to the highest levels at a certain premixed ratio. Afterwards, both CO and HC emissions begin to decrease substantially. Smoke opacity improves by up to 35%--55% at different equivalence ratios with the premixed DMM. NOx emission decreases by about 35% at the premixed ratio of 20% for different equivalence ratios.
出处
《燃烧科学与技术》
EI
CAS
CSCD
北大核心
2008年第6期511-517,共7页
Journal of Combustion Science and Technology
基金
教育部博士点基金资助项目(20070248112)
