微通道湍流促进器强化平板MBR的CFD数值模拟

CFD simulation of micro-channel turbulence promoters in a flat sheet membrane bioreactor

采用CFD中的Standard k-ε湍流模型模拟微通道湍流促进器在平板膜生物反应器中的5种不同放置位置及其6种不同形状对膜生物反应器流体动力学性能的影响,通过定性和定量分析附加微通道湍流促进器后平板膜生物反应器中的流体速度、静压、湍流动能、湍流耗散率和剪切力性能指标的变化。从模拟结果可得出,附加微通道湍流促进器的平板膜生物反应器的流体动力学性能要优于无湍流促进器的流体动力学性能,且梯形微通道湍流促进器双面平行放置于平板膜生物反应器时增加流体速度、湍流动能和剪切力且湍流耗散率和静压增加幅度较小,并在微通道湍流促进器附近有涡的产生,从而有效抑制膜表面滤饼层的形成,减缓浓差极化和减轻膜污染。

CFD is used to simulate the six shapes and five positions of micro-channel turbulence promoters in a flat sheet membrane bioreactor. Through the CFD, the qualitative and quantitative performance of hydrody- namics between micro-channel turbulence promoter and fiat sheet membrane channel was obtained according to the distribution of velocity magnitude, static pressure, turbulent kinetic energy, turbulent dissipation rate and wall shear stress on the membrane surface, which benefits to fully understand the effects of different shapes and positions of micro-channel turbulence promoters on flow pattern and feature. The simulation results showed that micro-channel turbulence promoters can increase velocity, turbulent kinetic energy and wall shear stress on the membrane surface and produce eddy in the vicinity of micro-channel turbulence promoters which enhance the fil- tration performance, and the trapezoid turbulence promoter sided parallel placed on the membrane surface can disrupt the buildup of cake layer, reduce the concentration polarization and mitigate membrane fouling.