CFD modeling of particle-particle heat transfer in dense gas-solid fluidized beds of binary mixture

► A particle-particle heat transfer model is established in a gas-solid fluidized bed. ► Particle-particle heat exchange coefficient rises as increasing large particle size. ► Particle-particle heat exchange coefficient increases with increasing gas velocity. ► It first increases and then decreases with increasing large particle concentration. ► The ratios of conductive to convective heat transfer range from 1.27% to 3.09%.