摘要
为研究大型混流式水轮机组尾水管压力脉动,选择了不同的水头和导叶开度组成不同的工况稳态和过渡过程工况。研究表明,稳态工况下,压力脉动的频率主要受导叶开度的影响,相同工况下,压力脉动频率非常相近;不同频率对应的振幅中,频率为3 Hz左右的振动振幅明显比其他频率对应的振幅大;水头对振幅的影响,高水头比中低水头的大。在过渡过程中,2台机组先后甩负荷时,震荡波明显大于1台机组甩负荷的情况。1台机组甩负荷过程中,水头对震荡波影响不大。不同半径处的压力脉动在导叶刚关闭时会有所不同,有些半径处的压力脉动会出现短时间的突然增加,这个值甚至大于震荡波中最大的压力值。
This paper mainly research on the vibration of draft tube in a big Fransic turbine model. By using of subminiature pressure transducer disposed in the draft tube, which can be directly got the pressure disturbing in the draft tube. In this experiment, the pressure vibration in constant and transition have been respectively measured. Through choosing different head and guide vane to compose different work point, after measuring the pressure in different work point, and compare these data with each other, it can be seen： 1.tmder the constant work point, the frequency of pressure is mainly affected by guide vane, when the guide vane is settled, the pressure frequency is almost same, notwithstanding the different head： 2. among the vibrations of various frequency, the one whose frequency is 3 is more intense than others.3.in the middle and low bead,the bead can＇tdetermine the swing of the vibration as the guide vane can affect the swing as well,but in the high head,the swing is bigger than the ones in the middle and low head.4.in the transition,the vibration is evident stronger than the others,when 2 units cut load successively.5. in the transition of 1 unit cut load,the swing is equal with each other,it can be seen clearly,head doesn＇t operate on the swing.6. in the transition,the trend of vibration in the different radius will e different when the guide vane closing.In some radius,the pressure will rocket suddenly,and the pressure even is the peak value in the transition.
出处
《水力发电》
北大核心
2008年第3期83-87,共5页
Water Power
基金
武汉大学水资源与水电工程科学国家重点实验室开放基金项目(2004B011)
关键词
模型试验
尾水管
压力脉动
大型混流式机组
构皮滩水电站
huge Francis turbine
model experiment
vibration in draft tube
Gou PITAN power station
subminiature pressure ~ansducer
