Effects of biodiesel ratio and nozzle diameter on combustion and emissions of a biodiesel–DME-fueled engine

This paper compares the combustion behavior and emission of a turbocharged compression ignition engine fueled with biodiesel BD100, dimethyl ether DME100, low-proportioned biodiesel blends BD30, and medium-proportioned biodiesel blends BD50. The impacts of biodiesel ratio and nozzle diameter on combustion and emissions characteristics were determined. The findings show that BD100 with a nozzle 6 × 0.24 mm has the highest value of maximum pressure, maximum pressure rise rate, maximum heat release rate, and NOx emissions. DME100 with a nozzle of 6 × 0.40 mm has the lowest values. CO emissions and HC emissions of BD100 with a nozzle 6 × 0.24 mm and DME100 with nozzles 6 × 0.40 mm and 6 × 0.35 mm gradually decrease. Among biodiesel blends, BD30 and BD50 with two types of nozzles, BD30 with a nozzle 6 × 0.40 mm has the lowest value of maximum pressure, maximum pressure rise rate, NOx emissions, and soot emissions. Compared with BD50, BD30 with nozzles 6 × 0.35 mm and 6 × 0.40 mm has lower CO emissions, HC emissions, and smoke emissions.