Experimental investigation on combustion of diesel fuel and its blends with rapeseed methyl ester in off-road diesel engine

Abstract

The article presents test results of a four-stroke, four-cylinder, naturally aspirated, DI 60 kW diesel engine operating on diesel fuel (DF) and its 20 vol% (B20), 40 vol% (B40) and 60 vol% (B60) blends with biodiesel, produced in mobile fuel laboratory. There has been investigated the influence on engine combustion, economical parameters, emission of the exhaust and smoke opacity. Bench testing results showed that when the engine was running at 1400 min"' speed on moderate loads, the auto-ignition delay was longer while engine was running on biofuel blends. When engine was operating at low load in-cylinder pressure peak and pressure rise rate increases with increasing the amount of RME in fuel. When the engine was running on fuel blends, the brake specific fuel consumption increased in comparison with diesel fuel. The higher brake thermal efficiency was obtained with diesel fuel. In case of using fuel blends at full load and 1400 min"' speed, the emissions of nitrogen oxides, unburned hydrocarbon and exhaust opacity decreased, carbon monoxide emissions was higher than using diesel fuel.