关于混流式水轮机水力稳定性的几点建议

混流式水轮机在远离设计工况（最高效率点）运行时，会产生脱流和涡带，引发机组甚至相邻混凝土构件振动，并可能产生疲劳破坏。近年来，随着水轮机比转速和单机容量的提高，有些电站因水头变幅大，转轮性能不完全适应电站条件，运行工况欠佳，制造质量存在问题和补气不力，运行稳定性问题已引起广泛的关注。本文综合国内外情况，对混流式水轮机的水力稳定性问题进行了初步分析，并提出一些建议。

Hydraulic Stabili ty Problem of Francis Turbine

When Francis turbine operates in the off design condition, the flow in the runner will be separated and vortex will appear. It will cause vibration at the units and adjacent concrete structures. Fatigue cracks of parts may be created. Recently, the hydraulic stability problem has been concerned extensively along with the increasing of specific speed and capacity or other cases(the head variation in a large range, the operating condition is off the design point, poor manufacturing quality and insufficient air admission, etc.). The preliminary analysis on hydraulic stability of Francis turbine has been carried out,and some suggestions have been proposed in this paper.