The Operating Characteristics Of The High-pressure Common-rail Diesel Engine Fueled With Biodiesel

Faced with increasing scarcity of oil resources and the ecological environment is deteriorating and so on, the applied research of alternative fuels is imperative. Among the many alternative fuel, bio-diesel fuel is being greatly concerned as its good performance, environmental characteristics and advantages of renewable. With the development of bio-diesel industry and the rapid promotion of high-pressure common rail diesel engine, the research of bio-diesel fuel for high-pressure common rail diesel engine has a high application value.This paper reviews the status of study abroad bio-diesel, bio-diesel preparation methods, summarized analyzes the physical and chemical properties of bio-diesel and the influence relationship between its fuel properties and the performance of the high-pressure common rail diesel engine. In order to explore the changing rules and influence of atmospheric pressure on performance of the diesel engine while burning blended fuel with bio-diesel,the comparative experiments have been carried on between pure diesel oil,B10 and B20 bio-diesel blended fuel on the bench of high-pressure common rail diesel engine under different atmospheric pressures.The results indicate that:with the atmospheric pressure increases, the power performance is increasing, the brake specific fuel consumption and exhaust temperature have been improved; With the dropping of atmospheric pressure from 100kPa to 81kPa, there is a 1.7%～3.4% dropping on power performance when the engine running at middle or high rotation speed, and when the engine running at lower or middle rotation speed the power performance declined by 5.4%～20.4%; atmospheric pressure changes on the low load region has little effect on fuel consumption, a greater impact on the heavy load region, in low speed heavy load especially regional differences; in the same pressure, Compared to burning diesel, the power characteristics of diesel engine using B10,B20 declined by 0.7%～2.6%,1.7%～6.1% respectively, increased by 0.7%～3.5%,1.3%～6.9% respectively; the difference of the exhaust temperature between B10 and BO is not obvious, the exhaust temperature of B20 is decreased slightly compared to pure diesel; there is no apparent influence on the trend of the power characteristics and brake specific fuel consumption of diesel engine using B10,B20 as the injection timing has been changed; bio-diesel can effectively reduce smoke emissions, the relationship between the volume of bio-diesel and the improvement rate of smoke emissions has direct ratio. In the same power comparative test conditions,the variation tendency of the pressure in the cylinder of different pressures and different fuel is consistent, the the pressure in the cylinder of diesel engine using bio-diesel is increasing.