Numerical and experimental investigation of a fluidized bed chamber hydrodynamics with heat transfer

Abstract

The hydrodynamics and heat transfer of a gas-solid fluidized bed chamber was investigated by computational fluid dynamic (CFD) techniques. A multifluid Eulerian model incorporating the kinetic theory for solid particles was applied to simulate the unsteady state behavior of this chamber. For momentum exchange coefficients, Syamlal-O'Brien drag functions were used. A suitable numerical method that employed finite volume method was applied to discretize the equations. The simulation results also indicated that small bubbles were produced at the bottom of the bed. These bubbles collided with each other as they moved upwards forming larger bubbles. Also, the solid particle temperature effect on heat transfer and hydrodynamics was studied. Simulation results were compared with the experimental data in order to validate the CFD model. Pressure drops and mean gas temperature predicted by the simulations at different positions in the chamber were in good agreement with experimental measurements at gas velocities higher than the minimum fluidization velocity. Furthermore, this comparison showed that the model could predict hydrodynamics and heat transfer behaviors of gas solid fluidized bed reasonably well.

CFD Modeling and Simulation of Hydrodynamics in a Fluidized Bed Dryer with Experimental Validation

“…Here v s,w is the particle slip velocity, e ss,w is the restitution coefficient at the wall, and ε s,max is the volume fraction for the particles at maximum packing [19][20][21][22][23][24][25]27]. …”

“…Hamzehei et al [19][20][21][22] investigated unsteady flow and heat transfer in a gas-solid fluidized-bed reactor. Also particle sizes, gas velocity, and drag models effects on hydrodynamics and heat transfer of a nonreactive gas-solid fluidized bed reactor were studied experimentally and computationally.…”

Gas Bubble Diameter and Rise Velocities in Tapered Fluidized Beds: Experiment and Computational Fluid Dynamics Simulation

“…Granular temperature can be defined as the kinetic energy of the random motion of the solid particles and is given as follows: Granular temperature conservation can be expressed as In the present work, the algebraic form of granular temperature was used due to more simplicity and computational efforts. In addition, achieving convergence with the PDE form is more time consuming. , …”

Study of Heat Transfer and Hydrodynamics in a Gas-Solid Fluidized Bed Reactor Experimentally and Numerically

“…and s r v , , a terminal velocity correlation, is expressed as The granular temperature ) (Θ of the solid phase is defined as one-third of the mean square particle velocity fluctuations. It should be emphasized that the granular temperature is proportional to the granular energy and is given as [13,14,20,21,23]. The transfer of kinetic energy, gs φ , due to random fluctuations in particle velocity is expressed as [1] s gs gs…”