Reliable operating regimes of the rybinsk hydroelectric station turbines: Fid-Bau Portal

Reliable operating regimes of the rybinsk hydroelectric station turbines

Shramkov, K. A.

Conclusions Comprehensive investigations of unsteady oscillatory processes in two turbines at the Rybinsk station revealed a difference in their cavitation properties: the runner of turbine No. 3, put into operation in 1949, has better cavitation characteristics and can operate practically in all regimes with comparatively little cavitation damage; the runner of turbine No. 1 put into operation in 1940, because of considerably worse cavitation characteristics can operate without noticeable erosion only at maximum heads (more than 16 m).Peak-load operation of the station with maximum loads at high levels in the lower pool is the most severe cavitation regime. A decrease in the average station load and accordingly a decrease in the lower pool level during the summer reduces the cavitation intensity.The occurrence of intense vibration of the unit-supporting assemblies and of pressure fluctuations under the turbine cover at small loads and during idle running (in the zone of disturbance of the normal combinatorial relation) requires that these regimes be avoided as much as possible.A relation was not found between vibration-fluctuation phenomena and development of cavitation in the load regimes at the Rybinsk station.The theory that an increase in the lower pool level (which is equivalent to increasing the depth of the runner at the same head) decreases the cavitation level was not confirmed at the Rybinsk station.