Effects of Injection Rate in Reduction of In-Cylinder Emissions in Heavy Duty Marine Diesel Engine

This paper attempts to investigate the effects of injection parameters such as injection rate and injection timing on fuel-air mixing and emission formation to find the best injection system for a high combustion efficiency and low emission heavy duty diesel engine. A CFD model is employed to analyze the injection and emission characteristics of a high-pressure common rail injection system. Results show that pilot injection strategies can be successfully used to simultaneously reduce smoke and NOx emissions. The pre- injection reduces the ignition delay that leads to reduction in the amount of premixed combustion and NOx emissions, but significantly increases soot emissions by increasing the diffusion combustion.

Keywords:

Diesel engine , Soot emission , NOx emission , Combustion modeling , Spray modeling