电站汽轮机调节阀振动试验研究

Experimental study on vibration induced by fluid flow in steam turbine control valve

针对电站汽轮机常用调节阀的不稳定和振动工况进行试验研究 ,利用微小型高频动态压力传感器等先进测试仪器 ,测量阀门内部流场 ,尤其是阀座喉部、阀瓣头部等关键部位 ,获得阀门流体诱发振动结论。在大压比、大升程条件下 ,喉部各测点的脉动压力不大 ,流动稳定。中小压比、中小升程时 ,压力脉动达到相对的最大值或变化最大 ,此时气流对阀瓣的作用力也达到最大。气流脉动一般含有小于几百Hz的主频 。

Experimental study on unstable and vibration conditions of control valve in steam turbine is carried out for commonly used control valve.A number of micro pressure sensors that have high frequencies and good dynamic performance are employed successfully and inserted directly in the pivotal positions of the valve to measure the internal flow field,especially in the positions such as valve seat throat,valve disc and so on.The result shows that in big pressure ratio and valve open conditions,gas fluctuation in valve seat throat is small and flow is steady.In middle and small pressure ratio as wellas middle and small valve open conditions,gas fluctuation is relatively maximum or varies violently,therefore the applied force on valve disc induced by fluid flow is maximum at this moment.The gas impulsion have some frequencies less than hundreds hertz,so harmonic vibration will take place easily.