【作者】 王鑫；

【导师】 马志豪；

【作者基本信息】 河南科技大学 ， 动力机械及工程， 2010， 硕士

【摘要】 石油短缺和环境污染问题促使了对石油替代燃料的研究。生物柴油是一种可供柴油机使用的清洁可再生燃料,它的主要成分是脂肪酸酯,是以油料作物、动物油脂及餐饮废油等为原料通过酯交换工艺制成的。生物柴油具有优良的环保特性,易于生物降解,而且闪点高,储运和使用安全,因此受到越来越多的关注。本课题首先以黄连木籽油和甲醇为原料制取生物柴油。分析其理化特性得出,黄连木籽生物柴油的主要成分为油酸甲酯、亚油酸甲酯和棕榈酸甲酯;黄连木籽生物柴油的十六烷值比柴油高很多,低热值比柴油低,密度稍高于柴油。然后在一台直喷式柴油机上,进行了不同比例黄连木籽生物柴油与柴油的混合燃料的发动机性能试验研究。结果表明:发动机燃用掺混生物柴油的混合燃料时,在中小负荷下,其燃油消耗率比柴油高,大负荷时与柴油基本相当。生物柴油的滞燃期比柴油短,压力升高率峰值和瞬时燃烧放热率峰值低于柴油,且预混燃烧峰值所在曲轴转角较柴油有所提前。混合燃料的燃烧持续期比柴油延长,最高平均燃烧温度与柴油差别不大。与柴油相比,生物柴油的CO、HC、碳烟排放均有不同程度的降低;B10、B20的NO_x排放比柴油低,而B30的NO_x排放与柴油相当。最后调整不同的供油提前角,在最大扭矩工况和标定工况,研究了柴油机燃用柴油及混合燃料的经济性、燃烧和排放特性。结果表明:在最大扭矩和标定工况下,四种燃料的最经济供油提前角几乎相同,即最大扭矩工况为上止点前15°CA,标定工况为上止点前19°CA。两种工况下,随着供油提前角的增大,最大瞬时放热率增加,最大爆发压力及压力升高率增大,最高平均燃烧温度增高,而燃烧持续时间缩短。CO和碳烟排放随供油提前角的增大有先降低又升高的趋势。随供油提前角的增大,THC排放降低,而NO_x排放大幅增加。更多还原

【Abstract】 The problems of petroleum shortage and environmental pollution impel the research of alternative fuel. Biodiesel is typically produced by a reaction of a vegetable oil or animal fat with an alcohol such as methanol or ethanol in the presence of a catalyst to yield mono-alkyl esters and glycerin, which is removed. Biodiesel has excellent environmental protection characteristic and biodegrade easily. Storage and transportation and application are secure in that it has high flash point. So biodiesel is attracted more and more attention.This topic first prepares biodiesel with pistacia chinensis bunge seed oil and methanol as raw materials. By analysing the physicochemical properties of this kind of biodiesel, It obtains that the main components of pistacia chinensis bunge seed biodiesel are methyl oleate, methyl linoleate and methyl palmitate, and the cetane number of pistacia chinensis bunge seed biodiesel is more higher than that of diesel, its low heat value is lower than diesel’s, and its density is slightly higher than diesel.Then experimental study of a direct injection diesel engine fuelled with Pistacia chinensis Bunge seed biodiesel/diesel blends. The study shows that the brake specific fuel consumption of the blends is increased at medium and light load when compared with diesel, and at heavy load it is similar for both the two types of fuels. With the use of the blends against the diesel fuel, the ignition delay is shortened, maximum rate of pressure rise and combustion heat release rate are decreased, the corresponding crank position of maximum premixed combustion peak is advanced, and the combustion duration is prolonged. Maximum cylinder mean temperatures with different fuels have little difference. The blends have lower CO, HC and smoke emission than those of diesel. The NO_x emission is reduced with the use of B10 and B20 but increased with the use of B30.Lastly, under different fuel supply advance angle, this study deals with the combustion characteristics and emissions of a direct injection diesel engine fueled with diesel/biodiesel blends is carried out. The study shows that the most economic fuel supply advance angle of the blends is almost the same at the maximum torque and rated conditions, that is to say, the most economic fuel supply advance angle of the blends is 15°before top dead center at the maximum torque condition and 19°before top dead center at rated condition. With the increase of fuel supply advance angle, CO and smoke emission is decreased first and then increased, THC emission is decreased, while NO_x is increased greatly. The blends have lower CO, HC and smoke emission than those of diesel. The NO_x emission is reduced with the use of B10 and B20 but increased with the use of B30.更多还原