一、前言以礼河三、四级电站安设的冲击式水轮机系由捷克“Skoda”工厂制造。该水轮机自一九六六年投入运行以来,由于在较大出力时产生剧烈振动,机组至今未能在设计的最大出力甚至额定出力下长期安全运转。一九六八年十二月间,三级电站~#3号机曾因水轮机下喷咀挡水板固定螺栓长期经受交变应力而疲劳断裂,使挡水板坠落,将水轮机转轮打坏,下喷咀喷针 I. Preface The impulse turbine installed at Lihe III and IV hydropower plants is manufactured by Czech “Skoda” factory. Since the turbine was put into operation in 1966, the unit has so far failed to operate safely for a long time under the maximum output or even the rated output of the turbine due to the violent vibration produced at larger output. In December 1968, the third-stage power station ~ # 3 had suffered fatigue fracture due to long-term alternating stress of the turbine nozzle bellow flaps, causing the flaps to fall and breaking the turbine runner , The nozzle nozzle