A Sensitivity Study of the Two-Fluid Model Closure Parameters (β, e) Determining the Main Gas−Solid Flow Pattern Characteristics

Abstract

The closures determining the interactions of particle−particle and gas−particle are very important for gas−solid flow. A three-dimensional two-fluid modeling approach with the kinetic theory of granular flow is used to simulate the hydrodynamic behaviors of a bubbling fluidized bed and a circulating fluidized bed. The influences of the coefficient of restitution and the drag model on the flow pattern are studied. The simulation results for bubbling beds are compared with the experimental results of Lin et al. It is found that the coefficient of restitution has strong influence on the flow pattern of the particle phase in bubbling beds. A relationship between the coefficient of restitution and the superficial inlet velocity is correlated. The effects of restitution coefficient on the distribution of solid phase in the circulating fluidized beds were also studied. In this case, the influence of the coefficient of restitution is weaker than for bubbling fluidized beds.

An Investigation of the Restitution Coefficient Impact on Simulating Sand-Char Mixing in a Bubbling Fluidized Bed

“…Many studies [16][17][18] have studied the suitability of different drag models. Generally, the Gidaspow drag model is suitable for simulation in a dense bubbling fluidized bed.…”

The effect of frictional pressure, geometry and wall friction on the modelling of a pseudo-2D bubbling fluidised bed reactor

“…shown to predict slightly higher bed expansions than the model of Syamlal and O'Brien used in this work [10,11].…”

“…Other closure models also have an influence on the solution, but the most important of these, the drag law and the particle-particle restitution coefficient in particular, have been explored in quite some detail in the literature to date (e.g. [10][11][12][13][14]). This work will therefore include only a brief assessment of these and other potentially important factors.…”

Effects of Gas–Solid Hydrodynamic Behavior on the Reactions of the Sorption Enhanced Steam Methane Reforming Process in Bubbling Fluidized Bed Reactors

“…11,12 The hydrodynamic parameters may also affect the reactions, and reversely the reactive flow may affect the solid flow patterns.…”