二甲醚均质充量与柴油喷射复合燃烧方式的发动机性能

摘要

In order to investigate the effectiveness of reducing smoke and NOx emissions of diesel engine,rnexperiment was studied on compound combustion mode of DME homogeneous charge and diesel fuel injection.rnCombustion of homogeneous charge of DME and diesel fuel was carried out on a high pressure common railrnturbocharged and intercooled diesel engine. The results indicate that under non-knocking condition, therneffective thermal efficiency with the engine operating on compound combustion mode is similar to that of dieselrnfuel injection combustion mode only. At low load condition and working on compound combustion mode, therneffective thermal efficiency is slightly lower. However, at medium and high load conditions, the results arernopposite. NOx and smoke emissions are reduced significantly when operating on compound combustion mode. Atrnhigh load condition, HC and CO emissions come to near for both the compound combustion mode and dieselrnfuel injection combustion mode.%为了探索二甲醚均质充量对降低发动机的氮氧化物和碳烟排放的有效性,在一台高压共轨增压中冷柴油机上进行了二甲醚均质充量与柴油复合燃烧性能和排放特性研究.试验结果表明:在二甲醚供给量控制在不发生爆震燃烧的前提下,发动机采用复合燃烧方式运转与单独燃烧柴油时的有效热效率相差很小,其中在低负荷时,复合燃烧时的有效热效率比单独燃烧柴油时稍低,但在中大负荷时比单独燃烧柴油时的有效热效率有所提高.复合燃烧时可以大幅降低发动机的氮氧化物排放和碳烟排放.在发动机大负荷工况条件下,对于两种燃烧工作模式,HC和CO排放量数值逐渐接近.