Effects of the turbulence and drag force on heat transfer characteristics in supercritical water fluidized bed

The Eulerian two-fluid model based on Kinetic Theory of Granular Flow was used to investigate the effects of the turbulence and drag force on heat transfer characteristics in supercritical water fluidized bed in this paper. Three drag models including Gidaspow, Syamlal-O'Brien and Wen-Yu drag models, and four turbulence models that are three high Renolds number turbulence model: standard κ - ε, RNG κ - ε, realizable κ - ε and a low Renolds number turbulence model, are adopted. The results show that the Gidaspow drag model is the most proper drag model in SCW fluidized bed among three models employed. As for the four turbulence models, the bed-to-wall heat transfer coefficients simulated with the three high Renolds number turbulence models are in a good consistency, and are all larger than that simulated with the low Renolds number turbulence model. RNG κ- ε turbulence model is the most proper one for the simulation of heat transfer characteristics in SCW fluidized bed with comprehensive considerations.