长引水隧洞水电站厂房动力特性研究

发布时间：2018-12-07 18:34

【摘要】：随着水电开发技术的成熟，大流量、高水头、高装机水电站已经是现阶段水电开发的主流，电站的安全问题也被提到了一个新的高度。电站厂房由于其结构的复杂化和巨型化，其振动不仅极为复杂且影响因素较多。研究电站机组水力、机械、电磁振源及其与厂房结构的耦联作用机制是彻底揭示厂房结构和机组振动的必要技术方法和手段。研究成果对优化电站运行状态、提高运行效率、保障厂房结构的安全具有重要的意义。结合某高水头、大流量、单机装机容量大的长引水发电电站，，将厂房结构和机组振动作为整体，通过现场试验和理论分析的方法达到研究的目的。本文的主要研究内容包括： (1)通过分析该电站机组的变负荷和变励磁工况运行试验的现场测试数据，对机组和厂房结构的实测数据进行结构振动和水流脉动的时域、幅值和频谱分析，以及振源分析和相关分析等，并确定机组的运行区划分。利用小波理论，对测点通频振动信号进行分段，得到各种主要频带的动力响应情况。 (2)通过分析机组在甩负荷、过速和启停机等特殊工况的现场试验测试数据，对过渡过程机组和厂房耦联体系进行动力响应分析。对过渡过程调压室水位的理论解进行了分析计算，结合甩负荷过程调压室水位现场测试数据，得到长引水电站过渡过程水流的变化特征。 (3)对厂房原型结构进行三维有限元模拟，机组对厂房的作用力通过附加质量单元实现。计算不同边界条件下厂房模型的模态并进行振型分析和共振校核。在此基础上对各振源频率进行横向、竖向和扭向的动力系数校核。计算厂房三向受力，并对厂房机墩进行动力谐响应计算校核。此外还对流道内不同水力振源频率进行脉动谐响应计算。
[Abstract]:With the maturity of hydropower development technology, large flow, high water head, high installed hydropower stations have become the mainstream of hydropower development at this stage, and the safety of hydropower stations has been raised to a new height. The vibration of power plant is not only very complex but also has many influencing factors because of its complexity and mega-structure. It is a necessary technical method and means to thoroughly reveal the vibration of power plant and unit by studying the coupling mechanism of hydraulic, mechanical and electromagnetic vibration source and its coupling with powerhouse structure. The research results are of great significance for optimizing the operation state of the power station, improving the operation efficiency and ensuring the safety of the powerhouse structure. Combined with a long diversion power station with high water head, large flow rate and large single unit installed capacity, the vibration of the powerhouse structure and unit is taken as a whole, and the purpose of the research is achieved by the method of field test and theoretical analysis. The main research contents of this paper are as follows: (1) by analyzing the field test data of variable load and variable excitation operating conditions of the unit, the time domain of structural vibration and water flow pulsation are obtained for the measured data of unit and powerhouse structure. Amplitude and spectrum analysis, as well as vibration source analysis and correlation analysis, etc. In this paper, wavelet theory is used to segment the pass-frequency vibration signal, and the dynamic response of the main frequency band is obtained. (2) by analyzing the field test data of load rejection, overspeed and start-up and shutdown, the dynamic response of the unit and plant coupling system during the transition process is analyzed. The theoretical solution of the water level of the surge chamber in the transition process is analyzed and calculated, and the variation characteristics of the water flow during the transition process of the long lead hydropower station are obtained by combining with the field test data of the water level of the surge chamber during the load rejection process. (3) the 3D finite element simulation of the prototype structure of the powerhouse is carried out, and the force of the unit on the powerhouse is realized by adding the mass element. The modes of the powerhouse model under different boundary conditions are calculated and the mode analysis and resonance check are carried out. On this basis, the transverse, vertical and torsional dynamic coefficients of each vibration source are checked. The dynamic harmonic response of the machine pier is calculated and checked. In addition, the pulsating harmonic response of different hydraulic vibration sources in the channel is calculated.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV731;TV312

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