The Effects of Design Parameters on Performance and NO Emissions of Steam-Injected Diesel Engine with Exhaust Gas Recirculation

In this study, an engine test with steam injection and EGR is conducted for investigating the effects of engine design parameters such as compression ratio (CR), charge temperature and pressure and equivalent ratio on a direct injection diesel engine performance and NO emissions using zero-dimensional single-zone combustion model. After the results obtained from the model are validated and well suited with those experimental studies of the diesel engines running with 20% steam ratio and 10% EGR, some important design parameters are investigated by using the theoretical model. As results, it was shown that effective efficiency, effective power and NO emissions increase with the increase of CR, inlet pressure for a constant equivalence ratio and inlet temperature. However, effective power and efficiency increase to certain values and then reduce, while NO emissions constantly decrease as the inlet pressure increases for various equivalence ratios.