加压鼓泡塔反应器中气液两相流CFD数值模拟

CFD Simulation of Gas-Liquid Flow in a Pressurized Bubble Column

对加压气液鼓泡塔反应器内的气液两相流进行了二维数值模拟,模拟的压力为0.5～2.0MPa,表观气速为0.120～0.312 m/s;模拟采用了Euler-Euler模型,并耦合了气泡群平衡模型(PBM)预测气泡尺寸,该模型考虑了气泡聚并与破碎对气泡的影响。液相湍流采用标准k-ε模型,两相间的作用力只考虑曳力。模拟获得了局部气含率、局部气/液相时均轴向速度及其径向分布等数据,并与实验结果进行比较。结果表明,局部气含率、局部气相速度模拟结果与实验结果吻合较好,局部液相速度径向分布特征模拟结果与文献结果相符。

Numerical simulation of gas-liquid flow in a pressurized cylindrical bubble column with two-flu- id approach were conducted for system pressures varying from 0.5 MPa to 2.0 MPa and superficial gas velocities from 0. 120 m/s to 0. 312 m/s. In the simulations, air is used as the gas phase and tap water as liquid phase. Euler-Euler model and population balance model （PBM） which predicted bubble size changes characterized were incorporated into the simulations. In the models, the effect of bubble break- up and coalescence were taken into consideration. A standard k-ε turbulence model was used to describe liquid phase turbulence viscosity in the simulations. The simulations only adopted the drag force for inter phase momentum exchange. The time-averaged gas/liquid velocities and local gas hold-ups were obtained from the simulations. The time-averaged gas velocities and local gas hold-ups were compared with experi- mental data and showed good agreement between measured and predicted data. The radial profiles of liq- uid velocities were in good agreement with the results of the literatures.