Numerical Investigation of the Effect of Fuel Preheating on Combustion Process and Emission in a Direct Injection Diesel Engine

The effect of fuel preheating on combustion process and emissions in a D.I. diesel engine is investigated using AVL Fire code. Computations are carried out using a three-dimensional model for flows, sprays and combustion in Diesel engines. Four cases for initial fuel temperatures have been studied here as follows:Tfuel =353, 373K as low temperature and Tfuel =473, 523K. It is shown that increasing initial fuel temperature leads to increased atomization of spray and better airfuel mixing. Also, reduced spray penetration due to increased evaporation prevents wall-film formation and considerably decreases soot mass fraction. Mean pressure, temperature, and NOx mass fraction are increased due to improved combustion. The results of model show good agreement with the corresponding data in the literature.

Keywords:

DI diesel engine , CFD , Combustion , Emission , Spray , Fuel preheating , wall-film