核电站汽轮发电机弹簧隔振基础设计

Spring Vibration Isolator Supported Turbo-generator Foundation in Nuclear Power Plant

以某1000MW核电站半速汽轮机发电机基础为例,通过有限元分析,得出"整体计算模型柱子的耦合效应以及弹簧水平刚度对于隔振基础的高阶振型频域分析影响可以忽略不计"的结论,验证了采用台板分离模型的可行性;利用单自由度系统振动方程验证了半速机组采用弹簧隔振系统的必要性;研究了杆系有限元模型刚性杆的刚度设置问题,提出了有限元模型值的重要参数取值建议;分析了弹簧阻尼器的水平阻尼比对汽轮发电机基础地震响应的影响曲线及弹簧阻尼器的竖向阻尼比对汽轮发电机基础振动响应的影响曲线,提出了阻尼器的最佳阻尼比。最后,引出并定性分析了弹簧隔振基础框架柱下筏板基础可采用独立基础的设计新概念。

Taking a turbo-generator foundation used in a 1000 MW nuclear power station as the example, this paper studied on the finite element analysis and drew the conclusion that the coupling effect of the columns and the horizontal spring stiffness on the high-mode frequency domain is so weak that can be neglected; the feasibility of the top-deck separation model was verified; the necessity of using the spring vibration isolation system was proved with the single-degree of freedom vibration formula. In addition, the rigid value of rigid beams and effect curves of the damping resistant to the seismic analysis and response state analysis were analyzed in detail; and based on the important parameters for finite element analysis, the reasonable damping ratio of the spring vibration system was proposed. Finally, the new concept of adopting the isolated foundation instead of the traditional slab foundation was put forward.