三峡船闸末级泄水阀门振动水弹性模型研究

 三峡船闸末级泄水阀门下接1 350 m涵管，用全水弹性模型对其振动问题开展了试验研究，采用模态分析方法确定了阀门结构的自振频率和振型，在流激振动试验中模拟了阀门正常运行工况和多种事故关门工况，测量了阀门振动加速度、脉动压力、吊杆应力。研究结果表明：在2 min匀速开门或匀速关门正常工况，阀门振动加速度均方根值一般小于5.0cm/s2，仅在小于0.1开度时达到25.37cm/s2；双边4 min事故关门中阀门振动加速度均方根值达22.57 cm/s2；单边事故关门，阀门振动比双边事故关门时的值大1倍左右，关门速度越快，振动越大。由于设计的动水关门速度较慢和检修门井的调压作用，阀门在试验条件下事故关门未发生有害水击现象，与同类阀门比较，该阀门的振动不会危害其安全运行。

Study on Emptying Valve Vibration of TGP Lock by Hydroelastic Model

The lowest chamber of the lock of TGP is linked with the main channel of Yangtze River by 1 350 m long tunnel. The flow - induced vibrations of emptying valve were studied by a hydroelastic model. The frequencies and modal shapes of the valve were obtained by both experimental and analytical modal analysis methods. The normal and emergency operating situation were simulated in model tests. The tests results show as follows: With 2 minutes opening or closing time,i.e., normal operating condition, the mean square root(MSR) value of vibration acceleration usually is less than 5.0 cm/s2, only at small opening (0.0-0.1) it reaches 25.37 cm/s2. In emergency condition during two valves closing simultanously in 4 minutes from full opening condition, the MSR value of vibration acceleration reaches 22.57 cm/s2, but when single valve closing in the same way the vibration acceleration of the valve is 2 times that appeared during two valves closing. The faster the valve closing speed,the stronger the vibrations are. With opening valve in normal speed till its halfway then immediately closing in 4 minutes, the vibrations are even stronger than those appeared during closing from full open condition. Because of low closing speed designed and the effect on pressure regulation of the overhaul shaft, harmful water hammer phenomena doesnt take place during tests. The vibration of the valve compared with that sustained by similar valve in other project is not
harmful to its safety. 