A shell-and-tube heat exchanger which is widely used for the heat recovery of air in a coal gasification system is investigated. FLUENT6.3 software is used and the RNG k−ε turbulence model is adopted for modeling turbulent flow. The porosity rate, the distribution of the resistance and the distribution of the heat source were introduced to FLUENT by coupling the user defined function. The variation of local heat transfer is studied under the effects of the baffles arrangement. The result shows that the porous media model can be applied in shell side of the air cooler in IGCC and the reasonable arrangement of the baffles can decrease the pressure drop with little influence on the heat transfer.