滞留气体对水电站引水系统运行稳定性的影响

摘要

水电站输水管道中局部高点易形成空气集中,滞留气体将增加管道的水力损失并引发水力激振,危及引水系统的安全运行.针对某水电站调水管道引水沟钢筋混凝土盖板水力冲击破损问题,就引水系统中存在的滞留气体对电站运行带来的影响进行了研究.受机组运行工况变化的影响,管道中滞留气体向上游传播形成水击,是导致上游建筑物破损的主要原因.对输水管路存在局部高点的电站,当管路中水流的佛劳德数小于临界佛劳德数时,在工程设计中应设置固定的排气装置.%The local high point in water conveyance pipeline of hydropower station is easy to form air concentration,and the residual gas will increase the hydraulic loss of pipeline and cause hydraulic exciting vibration,which will endanger the safe operation of water diversion system.Aiming at the hydraulic impact damage of reinforced concrete cover plate of water transfer pipeline branch ditch in a hydropower station,the influence of residual gas in water diversion system on the operation of power station is studied.As the changes of operating conditions of units,the residual gas in pipeline will spread to upstream and form a water hammer that is the main cause of damage of upstream building.In the case of a hydropower station with a local high point in water conveyance pipeline,a fixed venting device shall be provided in engineering design when the Froude number is less than critical Froude number.