Numerical Calculation of Spray and Combustion with Heating Fuel in a Medium Speed Diesel Engine

The fuel usually has high viscosity and low quality for marine diesel engines. Especially for its shallow combustion chamber structures, the preparation of in-cylinder mixture gas is mainly rely on spray and atomization, which is vulnerable influenced by fuel viscosity and surface tension seriously. Based on the case, this paper introduced a CFD method to heat the diesel fuel to reduce fuel viscosity and surface tension, expecting to explore the in-cylinder combustion process and emissions generation, so that the atomization effect of fuel spray and combustion in diesel could be improved. The calculation model was set up according to the L23/30H diesel engine. Temperature field and pressure field in cylinder were calculated and the emission of NO were studied under conditions of different fuel temperatures. The results show that the increasing of fuel temperature is helpful to realize low-temperature combustion and reduce NO emission to some extent.