Comparison of Combustion Characteristics under Internal EGR and External EGR in a DI Diesel Engine

Abstract

In order to reduce NOx emissions and the fuel consumption in a direct injection (DI) diesel engine, we pursued combustion and exhaust emissions characteristics under the internal EGR and the external EGR by the theoretical and experimental method. As a result, the following conclusions were obtained. Under the same NOx emissions, the external EGR is excellent in the point of the fuel consumption and the smoke emission compared with the internal EGR. And we were able to find the behavior of EGR gas in the cylinder, combustion and exhaust emissions characteristics under the each EGR.