Analysis of the results of the study of vibrations the supporting structure of the gates of spillway structures during the operation of hydroelectric power plants

Abstract

The article discusses the features of the operation of the main gates of spillway structures during the operation of the HPP. As it is known, the main spillway gates are installed at the outlet of the spillway openings into the downstream of the hydroelectric power station. The gates serve to block the openings of the spillway structure, which is opened to discharge water into a flood, as well as in the event of a disaster with an overlying hydroelectric power plant, thereby ensuring reliable operation of the entire water supply path of the hydroelectric power plant. Using the example of the Zhigulevskaya HPP, during the operation of the gates of the spillway structures, stresses in the gate structures, vibrations of the gate elements and the magnitude of the forces in the gate rod during lifting and lowering operations were determined, which made it possible to identify defects in their operation and determine recommendations for their elimination. In addition, the article discusses the results of the study of vibrations of the supporting structure of the gates of the hydroelectric power plant, which could be obtained only after identifying the features of the main gates on the spillway structures during the operation of the hydropower plant. Regarding the nature and origin of the measured oscillations, it can be said that it is not possible to give a clear explanation of the causes and physical nature of the gate oscillations at the HPP, therefore, the article considers two cases as a result of which periodic undamped gate oscillations may occur. Since it has been established that the periodic undamped oscillations registered on the gate could only be caused by a periodic disturbing force, the cause of such oscillations may be the periodic separation of vortices from the lower face of the gate. As a result, the analysis of the study of vibrations, the supporting structure of the shutter showed that the main disturbing forces for the shutter could be: pulsation of the flow pressure on the upper and lower surfaces of the shutter; dynamic forces arising when the vortices are detached from the lower face of the shutter when water flows out from under it. The article provides recommendations for avoiding vibration of the shutter in subsequent periods of operation.