混流式核主泵内部复杂流动结构分析

Analysis of Internal Flow Structures in a Mixed Flow Nuclear Main Pump

以混流式核主泵水力模型为研究对象,基于三维不可压缩流体的N-S方程和RNG k-ε湍流模型,采用流体计算软件ANSYS-Fluent对不同工况下的混流式核主泵水力模型的三维湍流流场进行数值模拟。通过分析不同特征面上的流动状态,构建该泵内的典型时均流谱,为性能优化及内部流动控制提供参考。计算结果表明:高涡量区域主要分布在固体壁面、径向导叶流道以及球型压水室内出液管附近;靠近出液管附近存在旋涡,导致流动损失增加,但随着流量减小,此处的流动情况趋于稳定,旋涡减弱甚至消失;靠近球型压水室出液管段的旋涡及其相近的径向导叶流道内的复杂流动情况与球型压水室出液管的位置有一定关系,因此减小出液管附近的流动损失,对实现混流式核主泵流动控制具有重要意义。

The research objective is a mixed-flow nuclear reactor coolant main model pump.Based on three-dimensional incompressible N-S equations and RNG k-εturbulence model,a numerical simulation has been applied,using computational fluid dynamics software ANSYS-Fluent.In order to provide a reference for performance optimization and internal flow control,the flow structures in the different feature sections are analyzed,and typical flow pattern is constructed.The result shows that high vorticity magnitude region occurs near the wall and among the guide vane channels as well as the discharge nozzle.Vortexes occur near the discharge nozzle of the casing and lead to flow loss.However,the flow loss decreases near the discharge nozzle with the flow rate decreases,and the vortex weakens even disappears.Thus,this phenomenon is related to the position of the guide vane blade,especially near the discharge nozzle.It is significant that the flow loss would be increased near the discharge nozzle to realize the control of the internal flow in the nuclear main pump.