含氧燃料特性对柴油机燃烧以及排放特性的影响

将质量比90％的柴油分别掺混10％菜籽油，10％DMC以及5％菜籽油和5％DMC的混合物，连同纯柴油组成10％RO，10％DMC，5％R0＋5％DMC和柴油共4种燃料，在一台单缸柴油机上进行燃烧、性能及排放试验研究．结果表明：含氧燃料的特性不同对比燃油消耗率和热效率影响较小，但对燃烧和排放影响较大．3种含氧燃料对柴油机缸内最大爆发压力影响不大．与柴油相比，柴油机燃用5％RO＋5％DMC和10％R0时，放热率峰值降低，滞燃期缩短，燃烧始点提前．燃用10％DMC时放热率峰值上升，滞燃期延长，着火延迟．与燃用柴油相比，柴油机燃用5％RO＋5％DMC和10％DMC时，除烟度有所下降以外，CO，HC和NOx排放均高于柴油．柴油机燃用10％RO时的烟度和Hc排放均低于柴油，而CO和NOx排放高于柴油．

Influence of Oxygenate Fuel Property on Combustion and Emission Characteristics of Diesel Engine

10% rapeseed oil （RO）, 10% dimethyl carbonate （DMC）, and 5% RO plus 5% DMC were separately mixed in pure diesel, forming three kinds of oxygenated fuels. Comparing with the pure diesel, some experiments on their combustion characteristics and emissions were carried out in a single cylinder diesel engine with these mixtures. Results showed that the properties of the oxygenated fuels had a little effect on fuel consumption and thermal efficiency, but greater influence on combustion and emission. These three oxygenated fuels have a little influence on maximum explosion pressure of the cylinder. Comparing with fueling the pure diesel, the ignition delay period was shorter with fueling two mixtures, 10% RO and 5% RO plus 5% DMC, but longer with 10% DMC. Comparing with the pure diesel, 5% RO plus 5% DMC and 10% DMC slightly made the CO, HC and NOx emission increase on full load condition of the engine, 10% RO has a lower emission on smoke and HC, and a higher emission on CO and NOx.