Computational fluid dynamics simulation of multi‐phase flow characteristics in an industrial‐scale randomly packed tower

Abstract

AbstractA three‐dimensional (3‐D) two‐phase Eulerian–Eulerian‐based computational fluid dynamics (CFD) simulation method coupled with a porous media model was developed in this study to simulate the air–water two‐phase flow in an industrial‐scale randomly packed air cooling tower (RPACT). The authors discussed the effects of gas kinetic energy factor, liquid load, packing materials, and packed bed height on the hydrodynamic performances of the gas–liquid counter‐current flow in the proposed RPACT. The simulation results show that the pressure drop increases with the gas or liquid load increases. Liquid load influences the pressure drop, liquid holdup, and wall film flow rate sensitively. A smaller liquid load, a middle range of gas kinetic energy factor, a relatively greater porous resistance coefficient of packing material, and a higher packed bed height can achieve a more uniform liquid flow distribution in an RPACT. The optimum operating conditions for the present RPACT are determined as gas kinetic energy factor is from 1.76 to 2.11 [(m/s) (kg/m3)0.5], liquid load is in the range of 32.40–67.73 m3/h, and the plastic Cascade ring (filled in the second packing layer) with a height of 10 m. The presented CFD models are useful for engineers to design and optimize the structure and operation conditions of industrial‐scale RPACTs.