煤基醇类混合燃料柴油机的燃烧及排放特性

摘要

利用煤基费托（Fischer Tropsch, F-T）燃料的高十六烷值特性和醇类燃料的含氧特性，提出了F-T柴油掺烧醇类燃料的煤基混合燃料的思路。在F-T柴油中添加10%体积比的甲醇﹑乙醇与丁醇燃料，通过与0#柴油比较来研究不同的醇燃料对发动机性能的影响规律。结果表明：相对于0#柴油，该混合燃料的燃烧始点提前，燃烧放热中心累计放热量达50%时对应的曲轴转角CA50向后推迟，燃烧放热率第一峰值点降低，预混合燃烧放热量降低；第二峰值点升高，扩散燃烧所占比重增加。在外特性下，混合燃料的NOx﹑碳烟与HCHO排放都大幅降低，并且相同体积甲醇燃料对于柴油机排放的优化效果更加明显。%An idea was proposed to use Fischer-Tropsch (F-T) diesel fuel blended together with alcohol fuel coal based fuel, which have high cetane value and oxygen. The combustion and emission characteristic effect was investigated for the Fischer-Tropsch (F-T) diesel adding 10% volume of methanol, ethanol and butanol fuel on comparing with 0# diesel fuel. The results show that compared to the 0# diesel fuel, the ignition time is advanced and the combustion heat release center CA50, means the crankshaft angle corresponding to 50% of the total heat release, is postponed. The ifrst peak combustion heat release rate decreases. Premixed combustion heat reduces. The other peak value increases and the diffusion combustion in proportion increases. Coal based Fischer-Tropsch alcohol mixed fuel can reduce NOx, carbon smoke and formaldehyde emissions and the same volume of methanol fuel has better effect on diesel engine emissions optimization, under external characteristic.