Investigation of the effects of the steam injection method (SIM) on the performance and emission formation of a turbocharged and Miller cycle diesel engine (MCDE)

The steam injection method (SIM) has been widespread to abate NOx of internal combustion engines (ICEs). Another NOx reduction method known in the literature is the Miller cycle (MC) application. However, this method causes a reduction in the power output. The most known technique which improves the engine power and decreases emissions is the turbo charging (TC). Hence, these three methods can be combined to make up for the power loss and to decrease pollutant emissions at higher rates. In this study, the combination of the SIM, TC and MC methods (SIM-TC-MC) has been carried out for a direct injection (DI), naturally aspirated diesel engine. The results have been compared with standard condition (STD) in terms of the engine performance and CO, CO2, NO, HC. Optimal condition has been determined as 10 CA retardation, 20% steam ratio of the fuel mass and 1.1 TC pressure (C62-S20-T1.1) in terms of the minimum NO formation. At this condition, NO, HC, CO and CO2 reduced by 48%, 35%, 64% and 8%; the increase rates in the brake power and brake thermal efficiency are 17% and 11, respectively. The results indicated that SIM-TC-MC may be implemented into a diesel engine to control NO and to obtain higher engine performance.