基于离散相模型的旋转填充床内的流场分析

利用CFD软件Fluent初步模拟了旋转填充床(Rotating Packed Bed,RPB)内的流体流动.计算中气相采用RNGk-ε湍流模型,液相采用拉格朗日离散相模型(DPM).通过一定简化后建立了旋转填充床二维模型,考察了液体颗粒在填充床内的速度分布,以及转速对液体颗粒速度的影响.结果显示液滴速度随转速的增加而增加,转速对液滴径向速度的影响不大.此外还针对转速、气体进口速度对干床压降的影响做了一定的研究,发现压降随转速的增加而增加,但其影响没有气体进口速度对压降的影响明显.填料的内缘处存在剧烈的端效应,模拟结果表明,端效应区的湍动强度明显大于其他区域.

Analysis of Flow Field for Rotating Packed Bed Based on the Discrete Phase Model

The computational fluid dynamics(CFD) software Fluent was used to simulate preliminarily the fluid dynamics in the rotating packed bed(RPB) reactors.The turbulent flow of gas phase was modeled by the RNG k-ε turbulent model,while the liquid flow was modeled by the Lagrange Discrete Phase Model(DPM) of multiphase flow.A simplified two-dimensional model for RPB was established to study the distribution of radial and tangential velocity of the liquid particles in RPB and the effects of rotating speed on the liquid particle velocity.Results indicate that the liquid particles velocity increases with rising rotating speed;however,rotating speed has little effect on the droplet radial velocity.The effects of rotating speed and gas inlet velocity on the pressure drop in dry bed were also investigated.It was found that the pressure drop increases slightly with rising rotating speed.In addition,it shows that a strong end effect exists at the inner edge of the packed zone,and the simulating results demonstrate that the turbulent intensity in the end effect region is significantly higher than that in other regions.