带长连接管的水电站调压室上下阻抗特性研究

Study on Characteristics of Upper and Lower Throttled Orifice in Surge Chamber of Hydropower Station with Long Connecting Pipe

对于带长连接管的调压室,为了方便施工,往往将阻抗孔口下置到连接管与输水隧洞相接处,但针对阻抗孔口在连接管内的位置对水电站水击压力、调压室涌浪和水击穿室系数的影响缺乏专门的研究。因此,通过理论分析和数值模拟方法研究了带长连接管调压室的阻抗孔口位置对水击压力、调压室涌浪和水击穿室系数的影响。结果表明,对于带长连接管的水电站调压室,阻抗孔口应上置在连接管与调压室大井相接处,且连接管直径越大,阻抗孔口上置对改善水电站的调节保证设计参数越有利,水击穿室系数越小。此外,还可在长连接管内装设阀门,增加连接管摩阻损失,通过优化阀门关闭规律实现调压室内涌浪的快速衰减。

In order to make construction convenient,designers often place the throttled orifice under the connection between the connecting pipe and the water conveyance tunnel for the surge chamber with long connecting pipes.However,there is no relevant research on the impact of the location of the throttled orifice on water hammer pressure,surge and water hammer pressure coefficient of hydropower station.In this paper,the impact of the location of the throttled orifice on the water hammer pressure,surge and water hammer pressure coefficient is studied by the method of theoretical analysis and model verification.The research shows that for the surge chamber with long connecting pipe,the throttled orifice should be placed at the junction of the connecting pipe and the surge chamber.At the same time,the larger the diameter of the connecting pipe is,the better the regulation of the hydropower station is when the impedance hole is placed.In addition,valves can be installed in the long connecting pipe to increase the friction loss of the connecting pipe,and the rapid attenuation of surge in the surge chamber can be achieved by optimizing the valve closing law.