直喷式柴油机燃用生物柴油燃烧特性的研究

Investigation on Combustion Characteristics of Direct Injection Diesel Engine Fuelled with Biodiesel

研究了柴油机燃用0#柴油和生物柴油的燃烧放热规律。通过对燃烧特征参数的计算分析,发现生物柴油的燃烧始点有所提前,滞燃期缩短;燃烧初期放热尖峰出现时刻对应的曲轴转角有所提前,瞬时放热率峰值下降;燃烧持续期延长。同时还比较了柴油机燃用生物柴油和0#柴油的经济性和排放特性,发现燃油消耗率上升12％左右,而各种排放污染物除NOx略有上升外,CO、HC和颗粒物(PM)均显著下降。

Combustion and heat release of diesel engine operating on both 0^# diesel and biodiesel were investigated. The results show that the start timing of combustion is advanced and the ignition delay period is shortened. The peak value of initial heat release is decreased and its corresponding crank angle moves close to the top-dead-center along with the increased combustion duration. Meanwhile, fuel economy and emissions of the diesel engine fueled with 0^# diesel and biodiesel were compared. The results show that the specific fuel consumption of biodiesel increases by 12 percent compared with that of diesel fuel due to its low heating value. CO, HC and particulate matter emissions decrease remarkably with the penalty of slightly increased NOx.