酯类含氧燃料组分对柴油机燃烧与排放特性的影响研究

摘要

To further research the influence of biodiesel and DMC mixing ratio on diesel engine performance ,90% diesel blen-ded fuels mixed with 10% biodiesel ,10% DMC ,5% biodiesel and 5% DMC were prepared respectively and formed B10 ,D10 , B5D5 and diesel four test fuels together with pure diesel .The effects of different oxygenated fuels on combustion process ,e-conomy and emission were investigated .The results show that the three oxygenated fuels have little influnce on maximum in-cylinder pressure and pressure rise rate .The maximum heat release rate of B10 slightly decreases ,while that of B5D5 and D10 increase significantly due to the addition of DMC .The ignition delay caused by DMC is more obvious than the ignition advance caused by the same amount of biodiesel .B10 and D10 have the same equivalent brake specific fuel consumption as diesel ,but that of B5D5 slightly decreases .When fueled with B10 ,CO ,HC and soot emssion all decrease except 7 .9% increase of NO x at full load .Though the introduction of DMC to mixed fuels is bad for the oxidation of HC and CO ,it can reduce the smoke and NO x emissions simultaneously .%为了进一步研究生物柴油和碳酸二甲酯（DMC）在柴油中的调配比例对柴油机性能的影响，在体积比90％的柴油中分别掺混10％生物柴油、10％DMC及5％生物柴油与5％DMC的混合物，连同柴油组成B10，D10，B5D5和柴油4种燃料，考察了不同含氧燃料对柴油机燃烧过程、经济性和排放性的影响。结果表明，3种含氧燃料对柴油机缸内最高燃烧压力和压力升高率峰值影响不大，B10的放热峰值略有降低，而DMC的加入使B5D5和D10的放热峰值明显升高。DMC造成的着火延迟效应要比同比例生物柴油造成的着火提前效应更明显。B10和D10的当量燃油消耗率与柴油基本相当，但B5D5的当量燃油消耗率略有降低。发动机燃用B10时，除NOx在全负荷时升高7．9％外，CO，HC和炭烟排放相对有所降低；而混合燃料中DMC的引入虽不利于HC和CO的氧化，但可同时降低烟度和NOx排放。