3D numerical simulation of gas-solid hydrodynamics and coal combustion in an industrial scale circulating fluidized bed

In this study, three dimensional numerical simulation of gas and sand particle hydrodynamics along with coal combustion in an industrial scale circulating fluidized bed (CFB) (including riser, cyclone and return leg) was carried out using a commercial code, ANSYS FLUENT. For modeling sand and gas hydrodynamics, Eulerian-Eulerian method (multiphase granular model), was used while for modeling coal particle trajectories, Eulerian- Lagrangian method (discreet phase model, DPM) was used. Also gas phase chemical reactions were solved via the Finite-Rate/Eddy-Dissipation model and particle phase chemical reaction were solved by multiple reaction model. User defined function (UDF) was used to re-inject the sand particles which left the domain via cyclone outlet. Simulation results such as exit gas temperature, sand volume fraction, pressure loop, and mole fraction of combustion products were compared with real data obtained from a 340 MWe CFB boiler located in Yeosu, Korea and showed good agreement.