Abstract:

The effects of soybean oil methyl ester biodiesel fractions from 0 to 30% in the dieselbiodiesel fuel blend on the exhaust pollutant emission behavior on the combustion characteristics of a direct injection diesel engine were investigated experimentally without engine modification. The results show that the power output of the engine decreases with the increase of the biodiesel fraction, but the power decrease is little at low biodiesel fraction, for fuel B10(with 10% biodiesel in fuel blend) only by 1.2%. With the increase of the biodiesel fraction, the engine brake specific fuel consumption increases, CO,HC and the smoke emissions decrease, NOx emissions increase but only a little. The in cylinder maximum combustion pressure and the maximum heat release rate reduce, while their corresponding crank angles delay, and the similar are for the beginning and end of the combustion. The ignition delay period and combustion duration increase for the more biodiesel blended fuel.

Key words: power machinery and engineering, diesel engine, biodiesel fuel, exhaust emissions, combustion