超重力旋转床中气液两相流动与传质过程的数值模拟

文中采用基于颗粒轨道模型的欧拉-拉格朗日法对超重力旋转床中的气液两相流动与传质进行了数值模拟研究。在合理简化丝网填料结构和考虑液滴凝并与分散的基础上,分别利用SIMPLE算法和颗粒轨道模型计算了超重力旋转床中的气流场和液滴的运动轨迹,进而计算了液相的传质系数。数值模拟所得的液相传质系数与氮气解吸水中溶解氧实验结果符合良好,表明模型能够用于模拟旋转床中流体力学和分散相内的传质过程。计算分析表明,对超重力旋转床,在一定的转速下,液体和气体流量以及填料内径的变化对体积传质系数有重要影响。

Numerical simulation of gas-liquid two-phase flow and mass transfer in a rotating packed bed

As a novel multiphase reactor, rotating packed bed (RPB) can greatly intensify the process of multiphase mass transfer. In this paper,a particle trajectory model attached in an Eulerian-Lagrangian method is used to numerically simulate gas-liquid two-phase flow in RPB. Based on appropriately simplifying construction of net packing and considering coalescence and breakage of liquid droplets, the flow field of the gas phase and the trajectory the liquid droplets in the rotating packed bed are simulated by the SIMPLE algorithm and the particle trajectory model respectively, upon which the mass transfer coefficient of the liquid phase is calculated. The simulated results are in fair agreement with the experimental data of desorption of O 2 dissolved in water with N 2, which verifies the applicability of the present model in predicting the fluid flow and the mass transfer in the discrete phase. It is illustrated by the numerical simulation that the flow rates of liquid and gas as well as the inner diameter of the packing greatly influence the volumetric mass transfer coefficient at a specific rotational speed.