Fluid thermodynamic simulation of EGR coolers used on diesels

The thermodynamics of the exhaust gas recirculation (EGR) cooler is very important for reducing oxides of nitrogen (NOx) emission of diesel engines. Using the CFDesign software, some 3-D fluid thermodynamic models of EGR coolers are established by using the finite element method (FEM); and the temperature, velocity and pressure fields of fluids in the EGR coolers are simulated and verified by experiments. Based on the FEM models, furthermore, the thermodynamic performances of the EGR coolers with different types of diffusers and different structures of cooling tubes are analyzed and compared. The results show that, the form of the diffuser has more remarkable effect on the loss of pressure than temperature; the EGR cooling efficiency may significantly be increased by properly design the cooling fin structures of the tubes inside the EGR coolers.