Study On Combustion Characteristics And Emissions Of A Di Diesel Engine Fueled With Pistacia Chinensis Bunge Seed Biodiesel

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.