超大型周进周出式沉淀池优化设计中的水力性能数值模拟

为改善超大型周边进水、周边出水沉淀池的水力性能,利用计算流体力学的方法对工程初步设计方案进行水力性能模拟.针对南方某污水处理厂直径为60m的周边进水、周边出水沉淀池,借助FLUENT 6.3软件包提供的realizablek-ε模型,运用交错网格有限体积法计算分析沉淀池的流场特征,提出了相关的优化设计参数.计算结果表明:竖向流进水并设置双向挡板的沉淀池,其内部环流的半径可增大至26~28m;径深比θ宜在8.0~10.0范围内选择;坡降i应控制为0.050.通过适宜的工程优化措施,可提升该沉淀池的内部环流性能.

Numerical simulation of hydraulic performance of optimally designed super sedimentation tank with peripheral inflow and peripheral effluent

To improve the hydraulic performance of a super sedimentation tank with peripheral inflow and peripheral effluent,the computational fluid dynamics method was used to simulate the hydraulic performance in a preliminary design scheme for a sedimentation tank.A case study was conducted in a sedimentation tank(with a diameter of 60m) with peripheral inflow and peripheral effluent in a wastewater treatment plant in the south of China.The optimal design parameters were determined through analysis of the flow field characteristics of the sedimentation tank calculated by means of the staggered-grid finite volume method,with the help of the realizable k-ε model provided by the FLUENT 6.3 software package.The results show that the radius of circulation increased to 26 to 28 m in the sedimentation tank with vertical flow and a two-way baffle,the appropriate ratio of diameter to depth(θ) ranged from 8.0 to 10.0,and the gradient(i) should be set at 0.050.The performance of circulation in the sedimentation tank could be improved by taking proper optimization measures.