Combustion characteristics of a compression-ignition engine fuelled with diesel-dimethoxy methane blends under various fuel injection advance angles

The combustion characteristics and emissions under various fuel injection advance angles in a compression-ignition engine fuelled with diesel-dimethoxymethane blends were investigated. The results showed that the ignition delay, the rapid burning duration and the total combustion duration increase with the advancing of fuel injection angle for both diesel fuel and diesel-dimethoxymethane blends. At a specific fuel injection advance angle, the ignition delay increases and the heat release rate in the premixed burning phase increases with the increase of dimethoxymethane fraction in the blends. The center of the heat release curve moves close to the top-dead-center, and the brake specific fuel consumption (bsfc) decreases and the thermal efficiency increases with advancing the fuel injection advance angle. Maximum cylinder gas pressure increases with advancing the fuel injection advance angle, and the maximum cylinder gas pressure of the blends gives a higher value compared to that of diesel fuel. The maximum rate of pressure rise and the maximum rate of heat release increase with advancing the fuel injection advance angle. The exhaust smoke concentration increased and the exhaust NO_x concentration decreased with decreasing the fuel injection advance angle for both diesel fuel and the blended fuels, and the behaviors were more obvious with decreasing the fuel injection advance angle.