Research On The Dynamic Property And Estimate Formulation Of Fundamental Period Of Air Cooled Condenser Platform

Air cooled condenser platform is a kind of new structural system, which is appeared with air cooled techniques. It is different with general structural style because of the nonuniform distribution of stiffness and mass in the vertical direction. At present, although the direct air cooled techniques is introduced into some thermal power plants, nearly all of them are designed by foreign institute. In order to promote the domestically process of this new structural system, studies on the property of this new structure have already conducted in our country. As continuation of the existing researches, this paper is focused on the analysis of dynamic property of air cooled condenser platform, which is composed of several partitions as following:Firstly, the field measurement and analysis of dynamic property of the air cooled condenser platform. The measurement is conducted in He Jin power plant, Huo Zhou power plant, Tuo Ke Tuo power plant and Jin Jie power plant respectively. The air cooled condenser platforms of He Jin and Huo Zhou power plant are single span, while that of Tuo Ke Tuo and Jin Jie are multi-span. In the field test, the fluctuating analysis method is adopted. The frequency of big fan should be recorded and excluded in the course of data analysis. According to the analysis in the time domain and in the frequency domain, the fundamental period and fundamental mode of the structure and whether there exists twisting and deformation are derived.Secondly, the finite element simulation and modal analysis of air cooled condenser platform. According to the design drawing and loading condition, finite element model of the air cooled condenser platform in Jin Jie power plant is established on the basis of simplicity. Then, modal analysis is conducted. At last, the result of field measurement is compared with that of finite element analysis.Thirdly, the analysis on factors that make influences fundamental period. Relation curves between fundamental period and different factors are formed via analyzing effect of different factors on the fundamental period.In the end, the formulation of fundamental period of air cooled condenser platform structure is derived by the method of optimize fitting and the aim of minimum variance. The formulation gives good practicability.