Heat Transfer Performance Analysis and Optimization of Exhaust Gas Recirculation Cooler with Different Structural Characteristics

In order to improve the heat transfer performance of an exhaust gas recirculation (EGR) cooler, different structural characteristics are numerically and experimentally studied. In numerical analyses, the presented pitted tube model and inner fin model, are compared under two typical working conditions, heat transfer efficiency solutions of inner fin model were 3~5% higher than that of pitted tube model. The inner fin model also gives smaller gas side pressure drop, which is only 17% of the pitted tube model. Then, the structural optimization of the inner fin model by analysing the various amplitude A was investigated. It is shown that increasing A results in increment of heat transfer efficiency and gas side pressure drop, the temperature requirement is satisfied and pressure drop is minimized when A=0.9 mm. The optimized numerical heat transfer efficiency solutions were 86.4% and 84%, and experimental results were 88.5% and 86.3% corresponding to working conditions, respectively. A good agreement was obtained. The optimized inner fin structure can be used efficiently to improve the heat transfer performance for an EGR cooler, the study method has been proven to be feasible by the simulations and experiments.