基于CFD方法的竖井贯流泵装置进出水流道优化设计

CFD method-based optimal design of inlet and outlet flow passages of shaft-tubular pump unit

运用计算流体动力学方法,基于雷诺时均Navier-Stokes方程和标准k-ε湍流模型,针对通吕运河水利枢纽工程贯流泵装置特征扬程和设计参数对全流道进行数值模拟,在给定的水位资料和土建控制尺寸范围内,对竖井贯流泵装置进、出水流道进行了CFD分析和水力设计优化。通过对三种不同竖井宽度的进水流道内部流态分析、水力损失计算和泵装置效率预测,优选竖井最大宽度确定为5.4 m,该方案设计工况下进水流道水力损失为0.053 m。通过对三种不同出水流道设计方案内部流态分析、对水泵的效率影响和水力损失计算,上翘角对直管出水流道内部流态、水力损失和泵装置效率产生一定的影响,对比分析采用底部上翘角为3.56°的直管式出水流道具有较优的水力性能,且采用该方案时挡土翼墙高度可减少约1 m。竖井贯流泵装置内流CFD分析与进出水流道优化设计可为同类型泵站的设计提供优化参考。

With the method of the computational fluid dynamics,a numerical simulation on the full flow passage is made for the characteristic pumping head of tubular pump unit of Tonglv River Water Control Project based on Reynolds time-averaged Navier-Stokes equations and standard k-εturbulent model,for which CFD analysis and optimization of hydraulic design are carried out on the inlet and outlet flow passages of the shaft-tubular pump unit within the ranges of the given data of water level and the control size of civil construction.By means of the analysis of the internal flow pattern,the calculation of the hydraulic loss and the prediction of the efficiency of the pump unit for the flow passage of the shaft with three different widths,the optimized maximum width of the shaft is determined to be 5.4 m,for which the hydraulic loss of the inlet flow passage is 0.053 m under the design operation condition of the scheme.Through the analysis on the internal flow pattern and the impact on the efficiency of the pump unit and the calculation of hydraulic loss for three different schemes of the outlet flow passage,the upturned angle has a certain impact on the internal flow pattern,hydraulic loss and efficiency of pump unit of the straight-tube outlet flow passage,the straight-tube outlet passage with the bottom upturned angle of 3.56°adopted in the relevant comparative analysis has a better hydraulic performance.Moreover,when this scheme is adopted,the height of the retaining wing wall can be reduced by about 1 m.Both the CFE analysis on the internal flow of the shaft-tubular pump unit and the optimal design of its inlet and outlet flow passages can provide references for the optimization of the design for the similar pumping station.