Different Atmospheric Pressure High Pressure Common Rail Diesel Engine Fueled With Bio-diesel Combustion And Emission Characteristics Of

Energy shortage and environmental pollution are two major problems faced by mankind in the21st century, and vehicle exhaust has become a major source of pollution of air pollution in large cities, so energy saving and environmental protection must become the irresistible trend of the development of vehicle industry, and the vigorously development of New type of renewable environmentally friendly fuels is imperative. On the one hand, there are big differences in the calorific value, viscosity, surface tension, density and other physical and chemical characteristics between diesel and biodiesel. These differences will affect the process of engine fuel injection and combustion organization correspondingly. On the other hand, more than65%of china region is plateau, so when engine run at different altitudes, the change of atmospheric pressure and air density will affect the engine's combustion process. Therefore, to research the changes in law and mutual influence relationship between the combustion process and emission characteristics under the different conditions of biodiesel and diesel mixtures for common rail diesel engine, it has great significance from both theoretical and practical applications.In this paper, we use high pressure common rail diesel engine which is not changed the conditions of the original parameters and is fueled with the BO, B30and B50do the test under the atmospheric pressure81kP and100kPa. To doing this, we can compare and analyze the disciplines which B30biodiesel blended fuel impacts the combustion characteristics, power, economy and emissions of the engine.Test results shows as following:the different atmospheric pressures have small impact on the engine's effective fuel consumption under the low load working condition, but have strong impact on the engine's effective fuel consumption under the high load working condition. As atmospheric pressure increases, CO emissions and HC emissions shows a downward trend, but the smoke emissions shows an upward trend. The engine's maximum explosion pressure, maximum combustion pressure rising rate and maximum heat release rate are going to downward trend as well as the rise of atmospheric pressure. Under the same atmospheric pressure, effective fuel consumption rates of burning B30were higher than the effective fuel consumption rates of burning BO; The HC,CO and smoke emissions of biodiesel are always significantly lower than pure diesel's during the entire speed range, and they will decrease as the biodiesel's proportion increasing, but the NOx emissions of biodiesel is significant higher than pure diesel's during the entire speed range from the beginning to the end. The engine's maximum explosion pressure, maximum combustion pressure rising rate and maximum heat releasing rate of burning B30fuel were lower than the engine's burning BO fuel.