Thermal and Fluid Simulation of a New Diesel Engine Cooling Exhaust Gas Recirculation System to Reduce Exhaust Gas Emissions

Abstract

Recalculating the exhaust gas into engine intake is a method that can considerably reduce the amount of NOX pollutant. By using the exhaust gas recirculation cooler (EGR Cooler), the efficiency of this method increase. The computational simulation is an exact method to analyse the heat distribution and pressure changes in EGR Cooler. In this study, the heat transfer characteristics of two types of new EGR Cooler were numerically investigated. The results of this simulation revealed When the U- shaped EGR Cooler containing wavy tubes perpendicular to the gas flow direction is used, the heat transfer coefficient improve of 25% compared to wavy tubes parallel to the gas flow direction. This research also revealed that the amount of pressure drop in full load in the two mentioned EGR Cooler is about 11kpa, but in the part load, the amount of pressure drop in both systems is so low. Therefore the use of the new cooling system has many benefits, in term of pressure drop and heat transfer efficiency.