Abstract:
The aim of this thesis is to study and analysis the cavitation phenomenon in Roseires power station.
The research presents the cavitation phenomenon featured by fluid machinery including cavity development related to the turbines operating conditions. The effects of the operating conditions, such as load, head and flow influence the development on machine efficiency, noise, vibration and damage are discussed.
The thesis state the cavitation problem in Roseires power station and the time in which the turbines subjected to cavitation during the intake cleaning process was recorded. The specific speed, cavitation index, and the critical cavitation index are calculated during the mentioned three periods (flood season, water restriction period and blackout) before and after dam heightening.
The results of the calculations indicated that the Cavitation occurred during the three periods since the cavitation index of all periods is less than the critical cavitation index before and after dam heightening.
Some points are recommended for loading units out of cavitation zone to reduce cavitation effect to minimum condition.
