DMF-柴油发动机燃烧和排放特性的试验

摘要

2,5-dimethylfuran (DMF) is a new biomass fuel for internal combustion engine. The effects of EGR rates on combustion and emissions characteristics were studied in a CI engine fuelled with DMF- diesel blends. The characteristics of D40 were compared with that of G40. Results show that D40 has longer ignition delay, higher indicated thermal efficiency but higher maximum rate of pressure rise. For entire EGR region, soot emissions are almost close to zero and the trade-off of traditional combustion between NOx and soot disappears. Although physical and chemical characteristics of DMF and gasoline are similar, the differences in combustion and emissions are much great due to their different ignition behav- iors. Compared to G40, D40 has slight higher NOx and THC emissions, but soot emissions of D40 are very low. Ignition delay is the main reason for the large difference in combustion and emissions fuelled with G40 and D40.%2,5-二甲基呋喃（DMF）是一种适用于内燃机的新型生物质燃料．在一台压燃发动机上，主要研究了DMF-柴油混合燃料（D40）在不同EGR率下的燃烧和排放特性，并与汽油．柴油混合燃料（G40）做了对比．结果表明，D40滞燃期较长，指示热效率较高，但最大压升率较高．在整个EGR区间，Soot排放一直接近于零，不存在传统燃烧的NOx和Soot之间的“trade—off”关系．虽然DMF的理化特性与汽油相似，但主要由于滞燃期不同，G40与D40在燃烧与排放特性上差别较大；相比G40，D40的氮氧和THC排放略高，但Soot排放极低．滞燃期是柴油机燃用D40和G40燃烧和排放差异的主要原因．