【摘要】 水电站直埋式蜗壳的钢衬和外围混凝土完全联合承载,蜗壳内部的静动态内水压力很大的比例可以外传至外围混凝土结构,从而引起蜗壳结构较大的振动反应。采用数学统计和Welch法的功率谱估计分析方法,针对机组升负荷运行时蜗壳振动测试信号进行分析处理。结果表明,在升负荷运行时,尾水管脉动压力为主要水力振源;蜗壳内部脉动压力、蜗壳外围加速度与尾水管脉动压力变化趋势基本相同;同时揭示了直埋式蜗壳脉动压力振动能量的衰减、传递规律。可为直埋式蜗壳的机组与厂房的振动评估及动力反馈分析提供可靠的依据。更多还原

【Abstract】 The steel lining and surrounding concrete of the complete bearing spiral case in a hydropower station bear the load jointly,and the internal water pressure inside the spiral case can be transmitted to surrounding concrete to a great extent,which will cause larger spiral case vibration.The mathematical statistics and the Welch method of power spectrum estimation are used to analyze and process the vibration signal of the spiral case.The results show that the fluctuating pressure from draft tube is the main hydraulic vibration resource during the period of increasing generating load,and the internal pulsating pressure of spiral case,the surrounding acceleration of spiral case and the draft tube fluctuating pressure have same trend.The results also reveal the attenuation and transmit rules of pulsating pressure vibration energy of the complete bearing spiral case.The study can provide reliable evidences for future research on vibration evaluation and dynamical feedback of the powerhouse and unit with complete bearing spiral case.更多还原