联合循环电站大型汽轮机非对称式混凝土基础振动性能试验研究

To study the vibration characteristics of the steam turbine generator foundation of a 1 600 MW combined cycle power station in a certain project, a 1: 10 scale model was designed and fabricated based on the model modal test method and according to the similarity theory. The dynamic characteristics of the foundation were tested using a force hammer multi-point spatial excitation and multi-point spatial measurement method, and the natural vibration frequency, mode shape, and damping ratio of the foundation were obtained. The dynamic stiffness at each bearing point of the foundation structure in three directions was tested by hammering method. The finite element analysis software was used for structural modeling, and the modal analysis method was used to obtain the natural vibration frequency and mode of the turbine generator foundation. The results were compared with the experimental results, and the calculated values are in good agreement with the experimental values, verifying the correctness of the both. The analysis of the foundation' s vibration response was completed, revealing the linear displacement pattern of the foundation in vibration under the operating state of the unit. The results show that artificial mass should be applied during the model test to satisfy the similarity relationship. Compared with common foundation structures, the steam turbine generator foundation has a higher natural frequency and dynamic stiffness, and the first three vibration modes are dominated by overall vibration. The vibration linear displacement, vibration velocity, and dynamic stiffness at each bearing point on the turbine generator foundation under the operating state of the unit meet the requirements of the specification limits. The research results provide a technical support for the design selection and model testing of large-scale steam turbine generator foundation structures.