The influence ethanol–diesel-biodiesel blends on performance and emissions of off-road diesel engine

The paper presents comparative analysis of the performance and emission characteristics when operating on various ethanol-diesel-biodiesel blends at various loads and engine speeds. The experimental tests were performed on a four-stroke, four-cylinder, direct injection, naturally aspirated, 60 kW diesel engines D-243. The in-cylinder pressure data was analysed to determine the ignition delay, the heat release rate, maximum in-cylinder pressure and maximum pressure gradients. The influence of ethanol-diesel--biodiesel blends on the brake specific fuel consumption and exhaust emissions was also investigated. The bench test results showed that when the engine was running on blends B15 and B15E at low loads and 1800 min-1 speed, the autoignition delay was 5% and 12% longer than that measured as a straight diesel. The maximum cylinder pressure and pressure gradients decreased by about 1–9 % with the increasing amount of anhydrous ethanol in the diesel fuel when operating at low load. When the engine load increased, the maximum cylinder pressure increased for all blends. The brake specific fuel consumption of blends B5-B15E increased by 1.6 and 8.9% for moderate and full loads, respectively, compared to the normal diesel fuel. The brake thermal efficiency decreased by 1.5%, and 4.7%, respectively, for the same operating conditions. The NOx, HC emissions decreased and CO emissions increased when operating on oxygenated blends B15 and B15EVytauto Didžiojo universitetasŽemės ūkio akademij