Eulerian–Eulerian numerical simulation of industrial‐scale biomass circulating fluidized bed boiler combustion under circulating ash control

Abstract This study employs the Eulerian–Eulerian two‐fluid model to conduct comprehensive computational fluid dynamics (CFD) simulations of a 75 t/h biomass circulating fluidized bed (CFB) boiler. Simulation results exhibit high correlation with experimental measurements of the CFB system's overall performance. The simulations generate detailed three‐dimensional data for industrial‐scale CFB boilers, including flow patterns, temperature fields, and gas composition distributions, with a focus on investigating the impact of circulating ash control on combustion characteristics. This study elucidates the mechanism whereby ash discharge control regulates the circulation rate, thereby influencing combustion behaviour and pollutant formation. Results indicate that reducing the circulating ash flow rate increases the bed temperature and enhances combustion intensity, consequently lowering NO emissions. In contrast, CO and SO 2 formation remain largely unaffected by variations in ash discharge rates.