Vibration Response Analysis Of Reinforced Concrete Support Structure Of Large Steam Turbine And The Experimental Study Of Seismic Safety

With the rapid development of China’s economy,the number of generators in China has doubled in recent years,and more power generation facilities will be built in areas with high earthquake fortification and complex sites.As an indispensable power generation facility in the power station,the load bearing structure of the generator(the basis of the turbine generator)is very important to the whole power station,because the upper part of the generator is carrying the operating generator set when it is working.Based running safety of generator research today is endless,research methods are various,generally can be divided into two categories,model test and numerical simulation,but for large steam turbine generator foundation,single adopt the method of numerical simulation based on steam turbine often cannot truly reflect the working status and the stress characteristics of the earthquake under the action of through model test method can be more intuitive reflect of motor based on a variety of vibration response under the environmental conditions.In this study,a 1:10 scale model was made based on the foundation of a1000 MW turbo-generator,a practical project of a power plant,and a series of modal tests and seismic tests were carried out on the model.The details are as follows:1.on the scale model adopts the method of random vibration modal experiment was carried out,in order to get the natural frequency and damping ratio of the structure of the foundation and the vibration mode of each order is used to research and determine the upper turbo-generator set in the lower part of the working frequency of the influence of steam turbine foundation,further evaluation of the steam turbine based on the safety of the steam turbine work condition.2.Adopt the hammering method to test the progressive stiffness of the turbine bearing at the top of the foundation.The dynamic stiffness test,as the name implies,is to test whether the deformation resistance of the bearing point of the upper turbine on the top of the foundation can meet the requirements of the actual engineering.3.Based on the analysis of various modes and considering the influence of various disturbing points on the foundation of the turbine,the vibration line displacement of the support seat at the upper part of the foundation under the influence of the vibration frequency at the whole stage from the start of the turbine to the normal operation is obtained,so as to further evaluate the operation safety of the foundation of the turbine.4.through quasi-dynamic test to the turbine foundation under the action of the earthquake force simulation,measured the turbine foundation under the action of theearthquake steel reinforcement stress characteristics and the deformation of the entire frame,and then to evaluate its safety under the action of the earthquake.5.The finite element software is used to carry out the seismic simulation of the turbine foundation,and the simulation results are compared with the final evaluation and test results of the safety of the infrastructure,so as to further verify the correctness of the test results.This study is to test and research is mainly based on numerical simulation study is complementary,and various natural vibration characteristics of the steam turbine generator in the direction of analysis and seismic safety evaluation,finally draw the conclusion: the formation dynamics,the order is good,in the upper steam turbine working normally better their mechanical characteristics,based on top of the dynamic stiffness value and vibration line displacement value can satisfy the requirements of the relevant specification,the infrastructure to safety and ensure the normal operation of the steam turbine unit bearing upper;Under the seismic action of the three working conditions,the members of the basic structure have no obvious deformation,and are basically in the state of elastic deformation.The stiffness of each part has not deteriorated,and it has a strong bearing capacity.The methods and data obtained in this experiment can be used as reference for similar model tests of turbine foundation in the future,and are of great significance for scientific research in the future.