【作者】 孙万泉；

【导师】 马震岳；

【作者基本信息】 大连理工大学 ， 水利水电工程， 2004， 博士

【摘要】 随着水电建设的快速发展,机组容量和尺寸急剧增大,转速相应提高,机组振动和其诱发的水电站厂房的结构振动已成为其运行和设计的重要问题。特别是我国已建、在建和将建一批高水头、大容量的抽水蓄能电站,由于其具有高水头、高转速和双向运行的特点,其振动频率大大高于常规水电机组,振动现象更加突出,因此,对支承结构的振动问题不容忽视。文中结合十三陵地下抽水蓄能电站厂房振动的现场试验研究和有限元数值计算分析,利用系统动态识别方法对水电站厂房结构的合理边界条件、动态特性参数和振动荷载进行了识别反分析。本文研究成果对提高抽水蓄能电站和大型常规电站厂房结构振动特性的认识和预测水平,以及现行设计规范修订具有积极意义;所建立的分析方法和计算程序也为今后类似的结构振动计算、识别分析和厂房合理的数值模型建立提供了技术支持和参考。 第一章绪论部分介绍了水电站厂房结构的振动问题和研究现状,并对有关系统识别的方法及其应用进行了简要的归纳和总结。 第二章在水电站厂房结构振动的已有研究成果基础上,以十三陵地下抽水蓄能电站为研究实例,利用ANSYS程序对厂房结构进行了有限元数值计算,通过正分析研究了厂房结构机械动不平衡力和水力脉动振源的合理作用方式及特性,并对影响厂房数值模型的边界条件、材料参数和结构附加质量等进行了计算分析,为今后厂房结构动态设计和后续的识别反分析提供了参考和依据。 第三章通过建立十三陵地下抽水蓄能电站主厂房与副厂房的耦联有限元模型,研究了主副厂房结构之间的振动传递途径和规律,为水电站副厂房结构设计和隔振研究提供了参考。 第四章系统研究了一种基于免疫思想的结构动态识别方法,并且将免疫算子与ANSYS中的APDL语言接口,建立起适合于各种大型复杂结构的通用免疫识别模型。 第五章利用以上所建立的免疫识别模型,并结合正分析的研究成果,从厂房结构振动强度控制出发,逐次对水电站厂房结构的高频水力脉动荷载、阻尼比系数,以及机械动不平衡力进行了识别分析,识别成果为今后水电站厂房的动态设计提供了参考。 第六章从水轮发电机组振动的角度出发,应用有限元方法建立了转子—轴承系统的动力学模型,提出了一种用等效弹簧力来模拟转轮处的水力脉动荷载,并且在不施加人工激励的前提下识别油膜轴承的动态特性参数和厂房结构的机组动荷载的复合反演法,通过数值算例验证了方法的有效性。更多还原

【Abstract】 With the rapid development of hydroelectric engineering, the capacity and size of the modern hydrogenerator units are larger and the specific speed of the hydraulic turbine is enhanced markedly. The vibration of powerhouse structure has become an important and ubiquitous problem during its operation and design, and the phenomenon is serious especially in pumped-storage power plants which units are higher-water level, higher rotate speed and higher vibration frequency than the routine units. Therefore, to advanced treat the vibration of powerhouse structure is very important and indispensable. In this paper, combining the finite element analysis and field test of The Ming Tomb Pumped-storage Power Plant, the rational boundary conditions, the average elastic modulus and the dynamic loads are analyzed in turn by system identifying method. All of this fill in the blanks of research on structural vibration of pumped-storage power plant and hydropower house with large-sized generator unit, and reinforce the current design code for hydropower house. The analytical methods and procedures provide a reliable technical support for the structural dynamic calculation, identifying analysis and the establishing of a rational numerical model.In chapter one, the existed problems and current research works on vibration of hydropower house are introduced, and the system identifying methods and its applications is summarized.In chapter two, based on finite element analysis of power house for pumped-storage power plants, in-site vibration experiment and theoretical analysis, the vibration sources of hydro-generating unit supporting structure are studied systematically, and the internal mechanisms and properties of the vibration sources are discussed. At the same time, the boundary conditions, structural parameters and the lumped mass are analyzed. The study is directive to the design of hydropower station.In chapter three, by establishing a coupled finite element model of the machine hall and its auxiliary plant, the travel path of vibration and their behavior are studied, which supply references to vibration isolation and analysis.In chapter four, a dynamic identifying method based on immune operator is researched systemically, and is jointed to the ANSYS Code to establish an optimal immune identifying model.In chapter five, on the basis of the immune identifying model obtained in chapter four and from the aspect of structural vibration of powerhouse, some significant modal parameters (including damping, average elastic modulus, boundary parameters and dynamical loads) are identified and studied. The conclusions give a useful reference for the establishing of a precise numerical model.In chapter six, from the aspect of structural vibration of hydraulic turbine, the dynamical models of flexible rotor-bearing systems are constructed using FEM. A frequency method of identifying the dynamic characteristic parameters of journal bearing and loads on field condition and without artificial excitations is proposed by supposing the hydraulic pulsation on turbine as an equivalent spring force. Some numerical examples demonstrate the validness of the algorithms.更多还原