某混流式水轮机转轮上腔压力优化设计

Optimum Design of Upper Cavity Pressure of the Runner of a Francis Turbine

本文以国内某混流式改造机组为研究对象,为降低转轮上腔的压力值,通过增加转轮泄水孔孔数和增大孔径,以及在泄水锥面开孔的方式优化该位置的水力特性。采用CFD软件对结构优化前、后的水力模型进行了对比分析计算。结果表明,结构优化后转轮上腔处的压力得到了有效降低,流经止漏环的漏水量也明显减少。研究结果具有一定的工程应用价值。

In this paper,a retrofitted Francis turbine in China is studied by increasing the number of runner drain holes and the apertures,as well as punching holes on the runner cone to optimize the hydraulic characteristics and reduce upper cavity pressure of the runner.The comparative analysis and calculation of the hydraulic model before and after structural optimization are carried out with CFD software.The results show that,after the optimization of the structure,upper cavity pressure of the runner is reduced effectively,the leakage through the wearing ring is also decreased significantly.The research results have some engineering application value.