Calculation, Research & Analysis On Air-Cooled Condenser Platform For Large-Size Thermal Power Plant

Air-cooled condenser (ACC) support structural system, as a new type of structure, is the important and major supporting structure of ACC island in thermal power plant. This structural system is comprised of steel space trusses in the upper part and ring-sectioned RC columns with large-diameters in the lower part, which is so-called steel and RC hybrid structural system. Its characteristics are of large span, tall height, heavy weight at the top, long cantilever of the supporting structure, many equipment piping, complicated member connections, and complex influence of operating loading and environmental actions (such as, seismic load, and wind load etc.)In recent years, direct air-cooled condenser turbine-generator unit has been widely used gradually, especially in northern part of China, for it is lack of water resource there. The government policy on restricting thermal power plant cooling water consumption is adopted clearly. In the approval of power plant projects in northern part of China by government authority, it is not recommended to use underground water and there are also some restrictions on using ground surface water of Yellow River drainage area. It is predicted that the ACC system will be developed further in this area. Because direct ACC or some other ACC systems (including mixed ACC system) for large-size thermal power plant in China are lack of operating experience, especially the systematical research works are almost blank, the application of such ACC systems are only based on overseas design information. Many of therelevant papers on the subject are theoretical calculations or references and lack of scientific payoffs of their own.The FEM structural model of ACC support structure is created by ANSYS, an FEM structural analysis software, to perform structural dynamic analysis, harmonic response analysis, and structural response under operating loads. The views to the structural seismic response analysis of ACC platform and the design countermeasures against earthquake are given in this thesis and sample calculations are conducted by FEM structural analysis program SAP 2000. The necessity and importance of considering the seismic influences to ACC platform are also emphasized in this thesis. At the same time, this thesis has put forward the treatment measures and recommendation of connection joints by 'release' of thermal stress and 'resistance' of earthquake.