Computational modeling of pulverized coal fired boilers - A review on the current position

Computational modeling of pulverized coal fired boilers has made considerable advances in the past 5 decades. Modeling the furnace of a coal-fired boiler is a complex task. Even though bulk of the heat transfer to the furnace water walls is by radiation, it is complicated by the presence of ash and other tri-atomic gases that participate in radiation. It is also necessary to accurately capture the kinetics of the devolatilization, char combustion and volatile combustion processes. The phenomenon of fluid flow is equally important since considerable amount of turbulence is involved. Any model developed for the prediction of critical performance parameters like furnace outlet gas temperature and pollutant emission levels will need to capture this multifarious nature of combustion inside a boiler furnace. While computationally expensive CFD codes are available in plenty, researchers have also developed simpler but effective reactor network models. This review explains the current research position in the computational modeling of pulverized coal fired boilers from the following perspectives i) Coal combustion modeling ii) Radiation modeling iii) Overall furnace model development.