Simulation of transport phenomena in coke oven with staging combustion

Abstract

A three-dimensional transient mathematical model was developed for coupled coking chamber and staging combustion chamber in large-capacity coke ovens, to describe the flow–combustion–thermo behavior. The model was solved numerically using CFX CFD package and was validated by the central temperature evolution of coke bed. The fields of temperature, fluid flow and combustible gas concentration were analyzed, with special reference to the temperature difference of coke bed and NO concentration of exhaust. The results show that staging combustion plays an important role in improving temperature uniformity of the coke bed and reducing NO concentration of exhaust, especially for the large-capacity coke oven. It is beneficial for production optimization to decrease the gas mass flow rate at the bottom inlet while increase the rate at the upper inlet in the combustion chamber. In addition, it turns out that some measures such as coal preheating, adjustment of moisture content or/and coal densification may be used to improve the coke production efficiency. It is expected the developed model and relevant data in the present research will be beneficial to realize large-scale coke oven with a higher energy efficiency and lower emission.