Numerical investigation of heat transfer in the clinker cooling process of grate cooler

Abstract

The grate cooler is the key device for clinker cooling; its internal heat transfer between cooling gas and clinker affects not only the clinker quality but also heat recovery efficiency. In this study, an unsteady numerical calculation model was developed, incorporating the porous media model and the local thermal non-equilibrium model, to describe the flow and heat transfer processes in the grate cooler. The reliability of the calculation model was verified using thermal measurement data. The simulation was carried out, and the effects of the cooling gas mass flow rate on the distribution of clinker temperature and exhaust gas temperature was discussed. The results show that both the gas and clinker temperatures decrease along the lengthwise direction of the grate cooler and increase along the direction of clinker layer thickness. As the cooling gas mass flow rate increases, the cooling effect of the clinker increases. However, the magnitude of this increase weakens as the air volume increases. Recirculating low-temperature air to the front chamber can improve the heat recovery efficiency of the grate cooler while ensuring effective clinker cooling.