导叶扩散度对核主泵水力性能影响的数值分析

CFD分析和试验表明，导叶对核主泵水力性能影响显著。为提高核主泵的整机效率，在最优比面积的基础上，提出了导叶扩散度的概念。选取控制扩散度大小的三因素及两水平，基于正交试验方法，获得了导叶几何参数的最佳匹配关系。研究表明：在叶轮 导叶比面积恒定的条件下，导叶扩散度对上游叶轮性能的影响较小，对导叶及下游蜗壳的水力性能的影响较显著。当导叶扩散度从零开始逐渐增大时，泵的效率先增大后减小，扩散度为0.025时泵的效率最高，此时导叶和蜗壳内的水力损失最小，导叶叶片的载荷分布合理。通过调整导叶扩散度提高整机水力效率的方法，将为核主泵的水力设计提供理论参考。

Numerical Analysis of Influence on Hydraulic Performance of Guide Vane Diffusivity in Nuclear Main Pump

The CFD analysis and experimental results show that guide vane has a significant influence on the hydraulic performance of nuclear main pump.In order to improve the efficiency of nuclear main pump,the definition of diffusivity of the guide vane was proposed based on the optimal specific area.Three factors and two levels were selected to control the diffusivity.Based on the orthogonal test method,the optimal matching scheme of guide vane parameters was obtained.The research results show that under the condition that the specific area of the impeller and the guide vane is constant,the effect of guide vane diffusivity on the performance of upstream impeller is not significant,but is significant on the hydraulic performance of guide vane and the downstream spiral case.With the increase of the guide vane diffusivity from zero,the pump efficiency increases firstly and then decreases;while the diffusivity is 0.025,the pump efficiency is the highest,and the hydraulic loss of guide vane and volute is minimum,at the same time the load distribution of guide vane is reasonable.The method to improve the hydraulic efficiency by adjusting the guide vane diffusivity will provide a theoretical reference for the hydraulic design of the nuclear main pump.