膜科学与技术

基于VOF对曝气后反应器内流场特性的数值模拟

作者：王海博¹※，李春丽² ，邱广明²※，郭枭²

单位： 1内蒙古工业大学土木工程学院，2内蒙古工业大学能源与动力工程学院，呼和浩特 010051

关键词：反应器；曝气强度；VOF方法；流场特性；数值模拟；实验验证

出版年,卷(期):页码： 2016,36(3):70-78

摘要：

本文采用VOF方法模拟了1mm曝气孔径下不同曝气强度对反应器内流场特性的影响规律，阐述了不同曝气强度下反应器中的气泡行为，分析了不同工况下反应器流场中湍流强度与速度场的分布特点，总结了曝气孔中心轴线高度方向上单一液相区速度值与湍流强度的变化规律，最后针对部分模拟结论进行了实验验证。结果表明：气泡脱离曝气孔出口瞬间为类蝌蚪状且一定时间段后尾巴消失进而底部开始向上凹陷， 96L/h及140L/h工况下曝气孔两侧膜丝之间出现了弹状流；初始气泡尾迹区产生了较强烈的湍流扰动并形成了类机翼形的速度涡环；曝气孔中心轴线高度20mm附近单一液相区出现了湍流强度变化喉部； 24L/h工况下单一液相区速度值在曝气孔中心轴线高度方向上呈线性升高， 96L/h及140 L/h工况下呈多段类线性规律升高；试验证明模拟结果较可靠。本研究可优化曝气控制膜污染过程的操作参数，能在一定程度上指导工程实际中曝气控制膜污染装置的设计过程。

In this paper, the influence law of the characteristics of flow field in the reactor under different aeration intensities at the aeration strength of 1mm was simulated by the method of VOF, the bubble behavior was described, the distribution features of turbulence intensity and velocity field of the flow field in the reactor under different working conditions were analyzed, the variation of velocity and turbulence intensity of the single liquid region on the height direction of the central axis of the aeration hole was concluded, and finally, the simulation was verified according to the experiments. The results show that the bubble changes into similar tadpole when it breaks away the aeration hole and the tail disappears after a certain period of time and then begins to upward sag, the slug flow begins to appear between the both sides of the aeration holes at the working conditions of 96L/h and 140L/h; a more intense turbulent disturbance appears from the wake region of initial bubble and the vortex ring of velocity of similar airplane wing forms; the laryngeal changing with the turbulence intensity of the single liquid region on the height direction at 20mm of the central axis of the aeration hole appears; the velocity of the single liquid region rises linearly on the height direction of the central axis of the aeration hole at the working condition of 24L/h; it rises which follows the multi-stage similar linear law at the working conditions of 96L/h and 140L/h. Therefore, the simulation results are proved to be reliable according to the experiments. In this study, the operating parameters of the process of the membrane fouling on the aeration control can be optimized, which can guide the design process of the devices of the membrane fouling on the aeration control during the engineering practice to some extent.

作者简介：王海博（1987-），女，陕西西安，主要研究方向：膜分离和水处理技术，E-mail：327947362@qq.com 通讯联系人：邱广明（1962-），男，教授，主要研究方向：高分子分离膜与水处理技术

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