Evaluation of a distributed combustion concept using 1-D modeling for pressurized oxy-combustion system with low flue gas recirculation

Abstract

Although process modeling of the pressurized oxy combustion (POC) with low flue gas recirculation (FGR) approved a great potential for CCUS cost reduction, there is no globally agreed concept for the boiler design that can satisfy the technical requirements of PC (pulverized coal) boiler operation. In this paper, a new concept for the boiler design and firing configuration based on distributing the combustion into multi-burner levels along the boiler height was evaluated using 1-D modeling. The 1-D model is mainly based on Gurvitch method to deal with radiation exchange between hot flue gases and water walls. Distributing combustion is proved to have remarkable potentials to control the peak flame temperature and heat flux. Two boiler sizes based on 30% and 53% FGR were analyzed which satisfied the critical indexes of the PC boiler operation. Finally, it was shown that distributed combustion concept has good potentials to operate under two abnormal conditions: i) with zero slag thermal resistance on the wall and ii) under low boiler operational load.