CFD Studies on the Air Flow in a Double-Grate Biomass Fired Boiler

Air supply is one of the most important factors that influence the combustion of the volatile and carbon in a biomass fired boiler. For many biomass power generation plants, there is insufficient measure to assure the proper air supply. In this study, computational fluid dynamics (CFD) modeling of a double-grate biomass fired boiler was carried out. The three-dimensional Reynolds averaged Nervier-stokes equation with the Standard k-epsilon Model was solved and the results were validated by the experimental data taken from a 1/30th scale cold model of the prototype. Simulations under various primary, secondary and ignition air flow rates and incidence angles were analyzed to identify the optimum airflow ratio. It showed that the combination of experimental and CFD approach could be an effective tool for the determination of air supply ratio.