含氧燃料特性对柴油机燃烧以及排放特性的影响

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

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%RO+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%RO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.

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.