海水脱硫散堆填料塔的流体力学计算

CFD in random packing columns within seawater desulfurization

采用体积平均法建立了描述散堆填料塔内气、液两相的流动模型;通过数值计算,获取了在不同液气比下塔内流体速度、孔隙率分布及压力分布,并就压力损失与实验值进行了对比,预测值与实验值吻合较好,趋势完全一致。分析海水速度分布图发现,靠近壁面处存在显著的壁流现象,并在沿流方向上液体有向壁区积聚的趋势,壁流现象变得更严重。由3种填料径向孔隙率分布图可看出,近壁面处的孔隙率明显高于中间区域,这是形成壁流的原因所在。

Gas-liquid two-phase flow CFD model is established to describe the random packing column in seawater desulfulrization with the method of volume average. Through numerical calculation, the flow velocity, porosity distribution and pressure distribution of seawater are obtained. Pressure loss are compared with experimental data, the predictive value and experimental value are well consistent, both have the same developing trend. Combination of seawater velocity vector in packed columns and velocity profile of the section on the middle high of the paced tower is analyzed, and find that there is a significant ＂wall flow＂ phenomena, and there is an accumulating trend near the wall along the direction of the liquid flow, and the ＂wall flow＂ becomes much more serious. According to the chart of the three kinds of filler porosity distribution on the radial direction, can see that porosity near the wall is significantly higher than the porosity of the middle region, indicate that this is the reason for the formation of ＂wall flOW＂.