大型水电站充水保压蜗壳受力及厂房动力分析

【作者】 郭涛；

【导师】 张立翔；

【作者基本信息】 昆明理工大学 ， 水工结构工程， 2008， 硕士

【摘要】 随着我国水电事业的不断发展,在建及将建的水电站机组的单机容量越来越大；蜗壳的HD值也急剧增长,蜗壳日趋向巨型化发展。蜗壳埋设方式的选择,是保证大型水电机组安全稳定运行的关键问题之一。为了充分发挥钢蜗壳的承载能力和降低外围混凝土的应力,减少配筋,使蜗壳结构安全可靠、经济合理、施工方便,通常对于大型水电站高HD值的蜗壳,国内外多采用充水保压埋设方式。对于充水保压蜗壳结构最关键的问题是,科学合理地选择保压方案与保压水头,并准确的掌握蜗壳外围混凝土的应力状态,而蜗壳钢衬和外围钢筋混凝土联合承载结构的研究,由于蜗壳结构复杂,且各实际工程之间差异较大,是一个非常复杂的研究课题,很难准确获得其应力状态。此外,大型水电站地下厂房,作为水电站的重要组成部分,它和机组的振动问题普遍存在,给电站的运行带来种种危害,甚至危及整个水电站的安全,这就使得水电站厂房的振动问题受到了普遍重视。因此,本文结合云南某水电站工程建设实际,在收集和总结前人经验的基础上,以大型通用有限元分析软件ANSYS为平台,首先研究了充水保压蜗壳结构外围混凝土受力状态和变形情况。接着,研究分析了各种主要因素对厂房下部结构自振特性的影响,同时对引起机组振动的机械、水力和电气等15种复杂因素进行阐述和分析,在此基础上按照相应的标准作出共振校核。最后,对厂房的抗震分析做出了安全评价。更多还原

【Abstract】 With the continuous development of the domestic hydroelectric industry, the unit capacity of the existed power station and the power station under construction is becoming larger and larger. The HD values of the spiral case also grow rapidly. Choosing the right embedding manners is one of the key points to guarantee the safe and steady working performance of the hydraulic turbine generator unit. In order to give full play to the steel spiral case, lower the stress of outside concrete, reduce the ratio of reinforcement and make the structure of the spiral case safe, reliable, economical and convenient, to a giant hydraulic structure with high HD value, the preloading filling spiral case structure is mostly applied at domestic and aboard. The most crucial issue to preloading filling spiral case is the responsible choice of preloading water head and accurately achieve outside concrete state of stress. Due to the complex structure and the larger difference between the every actual project, the study of combined bearing structure is a very complicated subject. In addition,the underground powerhouse of the large-scaled station, as an important part of hydropower station, often induces serious vibration problem, which brings various harm to run of the station, even give rise to danger of the whole station. So, the vibration of the powerhouse has been given a common emphasis.Therefore, this paper is focused on the above questions. Taking the substructure of a hydropower station in Yunnan as an example, Applying ANSYS program, we established whole 3D finite element model for the stress analysis of the preloading filling spiral case structure, gained the stress distributed disciplinarian and displacements. Secondly, we analyze the dynamic characteristics of the powerhouse under different condition. In addition, fifteen kinds of vibration source from the hydraulic, mechanic and electrical factors is give a detailed introduction and analysis. Based on the result of analysis, the resonance is calibrated. Finally, has made Seismic analysis of powerhouse and give the safety evaluation.更多还原