双溢流立体传质塔板上液相流场CFD研究

采用计算流体力学方法对直径为2 600 mm的工业规模双溢流立体传质塔板板上气液二相流动进行了模拟研究。计算了不同工况下收缩流和扩张流2种流型的液相流场分布,得到了双溢流塔板收缩流和扩张流2种流型的板上气液二相流场分布规律。通过将清液层高度的CFD结果和经验公式的计算结果进行对比,验证了所建模型的正确性。模拟计算结果表明:边降液管收缩流板面液相流动较均匀,近似于均匀的收缩流,不存在回流区;中降液管扩张流板面液相流动不均匀,靠近塔板中心流速较快,塔板弓形区存在着回流现象;板孔处的帽罩区液层较其他地方小,液相体积分数较其他地方低,扩张流受气相的影响较收缩流大。

CFD simulation of liquid flow field on double-pass overflow combined trapezoid spray tray

The gas-liquid flow of a commercial-scaled 2 600 mm double-pass overflow combined trapezoid spray tray(CTST) was studied by CFD simulation.The liquid flow field distributions of contraction flow pattern and expansion flow pattern were calculated at different operating conditions on double-pass overflow CTST,and the gas-liquid two-phase flow field distribution laws of the two flow patterns were obtained.The CFD results of clear liquid height are in good agreement with the empirical formula results,thus proving the validity of the CFD model for double-pass overflow.The results show that the liquid flow of center-to-side contraction flow pattern is uniform,and there is no recirculation zone,which are similar to the convergent flow.The liquid flow of side-to-center expansion flow is non-uniform,the velocity is great at the field near the center of the tray,and the recirculation phenomenon exists in tower board bow area.The liquid layer height and the liquid phase volume fraction of cap area are lower than those of other areas on the plate,and the influence of gas to side-to-center flow is greater than that to center-to-side flow.