核级多级离心泵间隙流动分析

Clearance Flow Analysis for Nuclear Multiple Centrifugal Pump

以典型核动力装置用多级离心泵中前腔和后腔为研究对象,采用CFD方法分析了前腔和后腔内的流动情况。分析中考虑了不同的间隙进口周向速度、间隙宽度对容积损失的影响,以及上述因素与泵内圆盘摩擦损失的关系,并对前腔流动情况和后腔流动情况进行对比计算,分析其不同流动特性产生的原因。分析结果显示:前腔中能量损失随相关参数变化较为复杂,需根据实际情况综合考虑;后腔中的摩擦损失比前腔更大,设计时应采取措施减小后腔位置的流动损失;应注意调整轴套间隙的宽度以减小后腔的摩擦损失,而口环间隙的宽度选择应综合考虑前腔的圆盘摩擦损失和容积损失。

In this paper,flows in the front chamber and the back chamber of the typical nuclear multiple centrifugal pump are analyzed by CFD method.Different inlet circumferential speeds,clearance widths are considered to analyze the effects on the volume loss and disk friction loss,and the flows in the front chamber and the back chamber are analyzed to show the reasons for various flow characters.According to the analysis results:Relationship between the power losses and structure and flow parameters in the front chamber is complicated and should be considered for certain pump.Some methods should be taken to reduce the friction loss in the back chamber.During structure design,it's suggested to reduce the clearance between the shaft sleeve and fixed structure,and the clearance between the impeller and suction adapter should be considered based on the combination of friction loss and volume loss.