Research On The Optimization And Dynamic Response Analysis Of Turbine-Generator Foundation In Thermal Power Plant

Turbine generator set is the core equipment of power plant,and its safe and stable operation is closely related to the dynamic characteristics of the basic structure bearing the turbine generator set.With the further development of thermal power industry in our country,increasing installed capacity,the structural performance requirements of turbine generator foundation are also more and more high.During the operation of turbine generator,there will be disturbing force,which will cause the vibration of the foundation structure.Generally,the vibration displacement of steam turbine foundation is controlled within 20μm within the operating frequency range of steam turbine generator,which leads to the stiffness control of the design of steam turbine foundation,forming a large section of beam-column frame foundation.On the one hand,the large section of beam and column members is not conducive to the layout of ancillary facilities such as process pipeline,on the other hand,the stiffness and excessive weight of the foundation structure will increase the seismic effect,although the impact on the infrastructure itself is not big,but on the turbine equipment and the connecting parts with the foundation caused an important impact.To solve these problems,this paper optimizes the turbine generator foundation structure and puts forward a new type of combination structure foundation form.The steel reinforced concrete member is applied to the foundation structure to reduce the section,natural vibration frequency and amplitude of the foundation.The vibration response and seismic displacement and acceleration response of steel concrete composite structural foundation of turbine generator are analyzed by means of theoretical analysis and numerical simulation.The main research contents and conclusions of this paper are as follows:(1)A new type of steel concrete composite structure foundation form of turbine generator is proposed,and the section size of the structural member is reduced by considering the stiffness of the beam and column members.The motion of foundation structure under equipment disturbance force is analyzed theoretically.(2)The finite element model of turbine generator foundation was established by ABAQUS for dynamic performance analysis,and the accuracy of the model was verified by comparing with the existing test data.On this basis,the foundation model of turbine generator steel-concrete composite structure and the foundation model of ordinary reinforced concrete structure are established,the dynamic performance analysis is carried out,and the calculation results of the two are compared.The anisotropic vibration displacements of two basic models under equipment disturbance are analyzed and compared.The results show that the natural vibration frequency of the steel-reinforced concrete composite foundation model is lower than that of the ordinary foundation model,and the low-order vibration modes are mainly translational.The maximum vibration line displacement of composite foundation is smaller than that of common foundation.(3)ABAQUS was used to analyze the time history of the turbine generator steelconcrete composite structure foundation model and the ordinary foundation model under earthquake.Three seismic waves were selected for nine working conditions,and the displacement response,acceleration response,interlayer displacement Angle and steel strain of the two foundation models were compared and analyzed.The results show that the steel concrete composite foundation of turbine generator can effectively reduce the acceleration amplification factor,and thus reduce the earthquake effect on the turbine equipment and its connection with the foundation.(4)In order to further improve the dynamic performance of the basic structure and reduce the section of the component,the spring vibration isolation foundation measures are adopted.The vibration isolation foundation model of steel concrete composite structure of turbine generator was established by ABAQUS.The vibration response analysis and seismic time history analysis were carried out.And the vibration isolation efficiency of the spring isolation device is quantitatively analyzed.The results show that the spring isolation foundation reduces the stiffness of the foundation structure and changes the natural vibration frequency of the foundation.In the X and Z directions,the vibration line displacement of the foundation is effectively reduced.Within the frequency range of 50Hz±10%,the vibration isolation efficiency of the spring isolation device reaches more than 96%,and the vibration isolation effect is obvious.The dynamic performance of steel-concrete composite foundation of turbogenerator can be significantly improved by using spring isolation device,and the section of the component can be further reduced.However,due to the change of cross-section stiffness,SRC isolation foundation is suitable for areas with low seismic fortification intensity.