抽水蓄能电站引水系统几何特性对蜗壳最大压力的影响

Influence of Geometric Characteristics of Water Diversion System to Spiral Case Pressure in Pumped Storage Power Station

抽水蓄能电站蜗壳最大水锤压力关乎管道的强度及机组的安全稳定运行,与引水系统几何特性密切相关。基于刚性水锤理论,定性分析了引水系统主/支管长度和横截面面积对蜗壳最大压力的影响规律,并针对实际工程开展了上述引水系统几何特性变动下的过渡过程数值模拟和验证。结果表明:蜗壳最大压力取决于引水管道中的水流惯性,引水管道总水流惯性越大,甩负荷工况下蜗壳最大压力越大;引水管道总长一定、主管与支管横截面面积之比大于2时,增大引水主管长度或增大管道横截面面积,可减小总的水流惯性,从而减小蜗壳压力;引水支管的长度一定时,减小引水主管长度或增大管道横截面面积,可减小总的水流惯性,从而减小蜗壳压力。

The maximum spiral case pressure of pumped storage power station is related to the strength design of pipelines and the safe and stable operation of unit,and is closely related to the geometric characteristics of diversion system.Based on the rigid water hammer theory,this paper qualitatively analyzed the influence of the length and area of main and branch pipes of the diversion system to the maximum spiral case pressure,and the transition process under the change of the geometric characteristics of the diversion system was numerically simulated and verified.The research result indicates that the maximum spiral case pressure depends on the water inertia in the diversion pipelines.The greater the total water inertia of the main/branch pipe along a pipeline,the greater the maximum spiral case pressure under the load rejection.When the total length of the diversion pipe is constant and the ratio of the main pipe to the branch pipe area is greater than 2,increasing the main pipe length or the pipe area can reduce the total water inertia and improve the spiral case pressure.While the length of diversion branch pipe is constant,the total water inertia can be reduced by reducing the main diversion length or increasing the pipe area,so as to improve the spiral case pressure.