Numerical analysis of heat and mass transfer coupled with gaseous fuel injection in reactive porous media

Iron ore sintering is a typical application of reactive porous media combustion (RPMC) which has been widely reported. In this work, a computational model of RPMC is developed, in which heat and mass transfer, as well as main chemical subprocesses in reactive porous media are incorporated. A gaseous-fuel injection method is examined to enable better heat pattern. However, the imbalance of heat distribution in the flow direction caused by internally recirculating heat released via a solid matrix is still problematic on energy efficiency. Through computations, it is observed that the heat pattern and melting quantity index (MQI) are sensitive on gaseous-fuel concentration, providing a possibility of improving the heat distribution imbalance. Numerical results are presented to demonstrate the benefits of fuel segregation. Finally, more reasonable heat pattern is observed by combinations of gaseous-fuel segregation with hot air and oxygen enrichment. The dynamics of gaseous/solid-fuel combustion zones caused by the hot air and oxygen enrichment would contribute to an expansion of melting zone near the inlet, producing a more reasonable and uniform heat distribution in a sintering bed.