Study On Vibration Transfer Of Pumped Storage Power Plant Based On “Energy Method”

China is rich in hydropower resources.With the rapid development of China’s economy and technological innovation,China has built a large number of large-scale hydraulic hubs in order to meet the production and construction.Hydropower plant is an important part of hydraulic hubs and the important place to convert water energy into electric energy,which requires higher structural safety.Pumped storage power plants are usually built underground,with many orifices,complex shape,low overall and local stiffness of the structure,which would be more severely affected by vibration.Structural vibration not only interferes with the normal operation of the unit,but also affects the precision equipment and staff in the auxiliary plant after transmission.Therefore,in order to reduce the vibration hazards in the auxiliary plant,it is necessary to conduct in-depth research on the energy distribution law in the auxiliary plant and the vibration transmission path between the main and auxiliary plant rooms.Based on the underground powerhouse structure of a large pumped storage power station,the "seismic energy method" is used to analyze the energy distribution law in the auxiliary powerhouse structure and the vibration transmission path in the main and auxiliary powerhouse rooms(1)A three-dimensional finite element model of the underground main and auxiliary powerhouse of a pumped storage power station was established.The seismic energy method was theoretically deduced and sorted out.The calculation formulas of different energy of the structure under the action of endogenous vibration sources were obtained.The analysis method based on the total input energy was determined,and the ANSYS energy output program based on APDL language was compiled.(2)In the model of unfilled structure in the structural joints of main and auxiliary plant rooms,the energy of floor and column structures of different floors in auxiliary plant under different vibration loads was analyzed,and the energy distribution map was obtained.The results showed that the way of vibration energy transfer into auxiliary building was inconsistent under different loads.The energy of low frequency mechanical load mainly depends on the surrounding rock and column at the downstream side,the energy of high frequency hydraulic pulsation load was mainly transmitted by the downstream wall rock,and the low frequency hydraulic pulsation load energy was mainly transmitted by the downstream side rock and the lower column.(3)The linear filling materials with different depth and stiffness were set in the structural joints of the coupling model factory room.The energy distribution and transfer law between the floor and column structure of the auxiliary workshop after the structural joint filling materials were analyzed.Taking the whole floor and column of the auxiliary powerhouse as the research object and the total input energy as the analysis index,the changes of the total energy amplitude in each structure of the auxiliary powerhouse under different filling depths and materials were compared,and the influence of structural joint fillers on the energy input in the auxiliary powerhouse was analyzed.The results showed that: the structure joint filler has a greater impact on the middle members of the structure,and the influence of the backfill structure on the auxiliary powerhouse under the hydraulic pulsating load was greater than the mechanical load;the energy input into the auxiliary powerhouse increased with the increase of the simulated elevation of the filler,and the energy decreased with the decrease of the filler stiffness in the structure joint.The research results of this paper provided a strong design basis for the equipment layout and staff workplace arrangement in the auxiliary plant,and also provided a design basis for reducing the vibration transmission in the main and auxiliary plant rooms.