Experimental study on the performance, combustion and emission characteristics of a high compression ratio heavy-duty spark-ignition engine fuelled with liquefied methane gas and hydrogen blend

The aim of this paper investigated the performance, combustion and emission characteristics of a high compression ratio heavy-duty spark ignition engine fuelled with liquefied methane gas (LMG) and different hydrogen blends under at low engine speed. In this study, a compression ignition engine was modified to inject hydrogen and LMG using port fuel injection in spark ignition mode. The results showed that the brake thermal efficiency increased with increasing percentage of hydrogen energy content. The equivalent fuel efficiency value dramatically decreased with increasing load and slightly decreased with increasing percentage of hydrogen energy content. In-cylinder pressures of all the blends with hydrogen are higher than that only LMG fuel. The heat release rate shifted to the top dead center (TDC) and the 50% combustion location was remarkably advanced with the increasing of hydrogen energy content. Furthermore, the maximum pressure rise rate increased and the location of the maximum pressure rise rate shifted to the TDC with increasing of hydrogen energy content, respectively. NOx emission dramatically increased with increasing load and hydrogen energy content, respectively. Conversely, HC and CO2 emission concentration declined with increasing of hydrogen energy content. CO emission concentration kept low value at all the loads.