Effects of air throttling on the performance and emission characteristics of a diesel engine

Abstract

The air-fuel ratio is a significant parameter related to engine performance, and can be controlled by adjusting the throttle valve and the amount of fuel injected. In this study, the performance and emission characteristics of an air-cooled single-cylinder MITSUKI MIT-178F diesel engine were investigated by imposing varying loads on the air throttling levels of 65%, 70%, and 75%. Accordingly, the torque generated by the engine increased as the air throttling level increased, and the fuel conversion efficiency was very low for the cases with air throttling levels of 65% and 70%. It was observed that the higher the exhaust gas temperature, the higher the NOx emission, and the lower the CO2 emission concentration as the engine speed increased. In addition, particulate matter (PM) concentration appeared to decrease as the air-fuel ratio increased under air throttling levels of 70% and 75%.