鼓泡塔内空气-醋酸体系流体力学参数的CFD-PBM耦合模型数值模拟

Numerical simulation of hydrodynamic parameters with air-acetic acid system using CFD-PBM coupled model

通过二维和三维CFD-PBM耦合模型对空气-醋酸体系中流体力学参数进行数值模拟,采用表面张力修正曳力模型与聚并模型,考察了醋酸浓度对鼓泡塔内气含率、气泡大小分布及轴向液速等参数的影响,与差压法、光纤探针和电阻层析成像技术(ERT)测量的实验数据进行了对比,并讨论分析了气含率和气泡直径等流体力学参数的模拟结果。结果表明,醋酸浓度在70%~80%(质量分数)范围内平均气含率存在最大值,且平均气含率的预测值在±10%误差内,三维模拟结果和ERT实验值吻合较好,说明修正后的模型在不同浓度醋酸体系中具有较好的预测性。

In this paper,the influence of the concentration of acetic acid on the hydrodynamic parameters in the bubble column is investigated in the bubble column PX oxidation reactor using two-dimensional and three dimensional CFD-PBM coupled model.The experimental data are obtained by differential pressure method,fiber optic probe and electrical resistance tomography(ERT)technique,and the simulation results are compared with the experimental values.The drag force model and the coalescence model are corrected by the surface tension term,and the modified model is used for numerical simulation in the acetic acid system with ambient temperature and ambient pressure.The simulation results of the hydrodynamic parameters are analyzed.The results show that when the concentration of acetic acid is in the range of 70%-80%(mass),the average gas holdup has a maximum value.The predicted value of the average gas holdup is within±10%error,and the three-dimensional simulation results are in good agreement with the ERT experimental value.The modified model has better predictability in acetic acid systems with different concentrations.