叶片开度对贯流式水轮机飞逸过程的影响

为有效降低水轮机飞逸过程中机组的振动问题，通过水轮机试验模型改变导叶开度和桨叶开度对水轮机过渡过程进行研究，分析了多个监测点的压力、频率流量等工作参数的变化情况。结果表明，由于转速和流量的增加，水轮机在导叶开度60°和桨叶开度4°运行时振动最为强烈，水轮机在低频时振动剧烈。由于受到导叶和桨叶动静影响，转轮出口振动强烈。导叶和桨叶慢速关闭能够降低压力脉动、轴向力、尾水管的真空度，但慢速关闭会增加负水锤，促进水轮机的破坏。使用遗传算法，通过加入权因子和罚因子，能够将水轮机多目标约束研究问题转化为单目标无约束研究问题，优化的导叶关闭规律对飞逸过程中出现的转速上升和压力上升有缓解作用，能够有效降低各点的振动。

Analysis of Impact of Blade Opening on Runaway Process of Tubular Turbine

We analyzed the changes of working parameters such as pressure, frequency and flow at multiple monitoring points. This can effectively reduce the vibration of the unit during the runaway of the hydraulic turbine. It is realized by changing the guide vane opening and blade opening of hydraulic turbine experimental model. The results show that the turbine vibration is the strongest when the guide vane is 60 degrees and the blade is 4 degrees, because of the increase of speed and flow. It vibrates strongly at the runner outlet due to the interaction between guide vane and blade. Pressure pulsation, axial force and vacuum degree of the draft tube can be reduced when guide vane and blade are closed slowly. This will increase the negative water hammer and promote the damage of the turbine. Furthermore, the multi-objective constraint problem of hydraulic turbine was transformed into a single objective unconstrained problem by adding weight factor and penalty factor and genetic algorithm. The optimized guide vane closing law can alleviate the speed rise and pressure rise and reduce vibration in the process of runaway.