Furnace modeling for efficient combustion gas circulation

In the conventional open flame aluminum casting furnace, a large proportion of the heat generated by the burners is wasted. Proper circulation of the flame's combustion gases could increase the fraction of heat transferred to the molten metal. In this work, we develop models for the aluminum holding furnace with an aim of optimizing the exhaust gas dynamics, for a more efficient casting process. Using the Finite Volume Method (FVM), fully coupled combustion, heat transfer and fluids dynamics models of the furnace are developed, on the commercial code StarCCM+. The exhaust and burner locations of a typical furnace design are varied to examine the effect of combustion gasses recirculation on the furnace's first law efficiency. In all models, the non-premixed flame (heat source) is simulated using the Eddy Break Up (EBU), 3-step reaction mechanism. The participating media radiation models are adapted for calculating the radiation heat transfer. Turbulence is modeled using the standard K-epsilon approach. Overall, our results highlight ventilation design considerations for the casting furnace.