液固流化床中颗粒流动特性的数值模拟

Simulation of hydrodynamics of particles in a liquid-solid fluidized bed

摘要:

应用欧拉-欧拉双流体模型,液相采用k-ε湍流模型,同时考虑液固两相间耦合作用,数值模拟液固流化床内液固两相流动,研究了液体密度和粘度对液固流化床内流动特性的影响.研究结果表明,液固流化床内液体、颗粒混合比较均匀,呈现散式流态化特性.颗粒轴向速度随着液体密度和粘度的增大而增大,并且在床内分布趋势相同.数值模拟得到床层膨胀高度的结果与Babu等人公式计算值相吻合.

Abstract:

Flow properties in a liquid-solid fluidized bed were simulated by means of an Euler-Euler two-fluid model.A k -ε turbulent model was used to simulate the flow behavior of liquid by considering the couplings between liquid and solid phases.The effect of liquid properties of density and viscosity upon flow properties was studied in the liquid-solid fluidized bed.Results show that the mixing of liquid and particles is uniform in the liquid-solid fluidized bed,and it exhibits a homogenous fluidization.The axial velocities of particles increase with the increase of liquid density and viscosity,and they both have the same trends in the bed.The simulation result of bed’s expanding heights is in an agreement with the calculation results of Babu et al..