Abstract: A two-bubble phase population balance model (TBPBM) was proposed by treating gas phase (bubbles) as two groups consisting of small and large bubbles, i.e. accounting for small and large bubble phases in terms of different laws of bubble dynamics based on the sizes of bubbles, in which the population balance model was applied and solved respectively for each bubble group to predict the bubble Sauter diameters. The use of two-fluid model coupled with the TBPBM has been tested to simulate hydrodynamics in a bubble column of 440 mm in diameter at the superficial gas velocity of 0.1 m/s. Bubble classes holdup-based probability distribution, radial profiles of time-averaged axial liquid velocity and gas holdup and bubble size distribution for each phase were obtained. The simulation has demonstrated that the predicted profiles of mean gas holdup and liquid velocity are in good agreement with the experimental data and the existing results reported in the literature. The simulation also indicates that the TBPBM model is superior to the SBPBM and mean bubble size models in bubble column hydrodynamics simulation. The error of the predicted overall gas holdup caused by using TBPBM model is 5.7%, while the errors by using SBPBM model and mean bubble size model are 27.2% and 17.3%, respectively.

Key words: coalescence and breakup, bubble column, gas-liquid flow, TBPBM model

摘要： 基于对鼓泡塔气泡行为的现有认识，把气泡分成大、小气泡. 首次建立了完整的双气泡相群平衡模型(TBPBM)，以预测气泡尺寸，并耦合TBPBM与CFD双流体模型对D=440 mm鼓泡塔进行数值模拟，获得了气泡尺寸体积概率分布、时均气含率与液相速度径向分布、大小气泡相尺寸分布，对部分模拟结果与实验值及文献模拟结果进行了比较. 结果表明，TBPBM-CFD模型预测的时均气含率和液相速度分布与实验结果吻合最好，较SBPBM、平均气泡尺寸模型的模拟结果有明显改善. 与实验值相比，TBPBM模型的整体气含率模拟误差为5.7%，而SBPBM模型和平均气泡尺寸模型的误差分别为27.2%和17.3%.

关键词: 聚并与破碎, 鼓泡塔, 气液两相流, TBPBM模型