Study On The Performance Of The Diesel Engine Fuelled With Diesel And Biodiesel With Different Injuction Timings

Biodiesel is one kind of alternative fuel, which can be manufactured from vegetable oils, recycled cooking greases or oils, or animal fats. In the process of biodiesel manufacturing, vegetable oil and animal fats are converted into fatty acid methyl esters or FAME, the major content of the biodiesel, and the Glycerine as by-product. It has the similar characteristics with diesel and can be used as alternative fuel on diesel engine with no or only minor modifications. Biodiesel gradually attracts people's attention and is seen as the strategic alternative fuel for diesel because of its renewable character and friendly character to environment.For deeply understanding diesel engine performance when fueled with biodiesel and the blend of biodiesel/diesel and optimizing the applying technology of biodiesel on diesel engine, the study on diesel engine fueled with biodiesel was conducted. Based on deeply understanding to biodiesel produce process and its physical and chemical characteristics, the paper studied the using performance of biodiesel and the blend of biodiesel/diesel. Futhermore, injection timing is adjusted for finding a way to improve diesel engine's performance and emission when fuelled with biodiesel and blend.Fuels used in the experimnet are Petroleum Diesel, biodiesel and the blend of 25% biodiesel and 75% Petroleum Diesel in volume ratio. the biodiesel used in the experiment is soybean fatty acid-first ester. the engine used in the experiment is a Sofim four-cylinder turbo charged direct injection diesel engine. Injection timing is changed into five different injection timings ,which include : original injection timing, advanced injection timing in 2 oCA and 4oCA, retarded injection timing in 2 oCA and 4oCA.the result shows that engine power could be remained or even higher, the fuel consumption slightly increased, but the specific energy consumption decreased slightly, though NOx emission level gets to be higher, the particulate matter(PM) emssion is decreased when the engine fuelled with biodiesel or blend. With injection timing starts to take place earlier the fuel consumption becomes less, NOx emission level is higher and PM emission level is lower. Adjusting the injection timing leads to general decrease of the engine power, but only the power could increase when fuelled with blend and the injection timing is 2 oCA advance.