大型半螺旋吸入室双吸泵优化设计

Optimization of Large-Scale Double Suction Pump with Semi-Volute Suction Chamber

对半螺旋吸入室双吸离心泵内部定常三维湍流进行全流道数值模拟。通过3种不同结构形式半螺旋吸入室水力性能的对比,分析导流板对半螺旋吸入室双吸泵性能的影响。运用计算流体力学(CFD)流场软件CFX,采用标准k-ε湍流模型,基于雷诺时均N-S方程,通过SIMPLE算法进行数值模拟分析。计算得到了半螺旋吸入室内部断面速度和压力变化分布图,获得了半螺旋吸入室双吸泵的水力特性以及吸入室水力损失占总损失的份额。计算结果表明:导流板偏置能够有效地改善半螺旋吸入室内部的流动变化规律,可以消除叶轮进口处的漩涡,使吸入口流线比较均匀、稳定,有效减少叶片进口绕流引起的压降,效率高且抗汽蚀的效果好;数值模拟与半螺旋吸入室双吸泵样机的试验结果符合较好。

In order to perfect internal flow law of double suction pump with semi-volute suction chamber and improve its anti-cavitation performance and efficiency, numerical simulation was conducted on the three dimensional steady turbulent flow in the whole flow passage of semi-volute suction chamber. The impact on hydraulic performance of double suction pump with semi-volute suction chamber by guide plate is analyzed. And result was obtained by contrasting three kinds of semi-volute suction chambers with structural differences. Using standard k-e turbulent model and based on the Navier-stokes equation, numerical simulation and analysis were conducted by SIMPLEC method and commercial CFD software CFX. By numerical computation, the velocity and pressure distributions of the interior flow field was analyzed, which revealed the flow principle inside the semi-volute suction chamber, the hydraulic performance and the hydraulic losses of double suction pump with semi-volute suction chamber was obtained. The results show that the offset guide plate can improve the internal flow law of semi-volute suction chamber, and can reduce the imports of the vortex impeller and hydraulic loss. Finally, the application examples from practical tests favorably validated the result s of simulation,, which provide theoretical basis for improving the design.