Radiation Modeling in Fluidized-Bed Coal Combustion

Abstract

Radiative heat transfer in fluidized-bed coal combustion is modeled by including emission, absorption and scattering from combustion gases, as well as from coal, ash and char particles. A full-spectrum k-distribution model is utilized for nongray gases and solid particles. The full-spectrum k-distributions of gas-particle mixtures are calculated from the narrowband counterparts. Over each narrowband, k-distributions of gas species are mixed according to Modest-Riazzi model before narrowband particle absorption coefficients are added to obtain a narrowband k-distribution of the mixture which are then collected into a full-spectrum k-distribution. The resulting radiative transfer equation is solved with the P1 approximation. The solver is implemented in MFIX for modeling fluidized-bed coal combustor.