Current trends in the design, investigation, and operation of hydraulic machines for pumped-storage plants

Abstract

1. The 6th symposium of the IAHR showed the ever-increasing interest of the international engineering community in problems of pumped storage. 2. The development of hydromechanical equipment in pumped-storage plants is along the line of increasing the capacities of the units and use of high-speed machines at higher heads. 3. A number of new types of turbine-pumps have been proposed lately which have, in the authors' opinion, a number of advantages that have undergone laboratory checking and are in the stage of industrial introduction. 4. When evaluating the operation of hydraulic machines in transient regimes special attention is given to resonant phenomena in pressure conduits which, if not taken into account, can result in a considerable underestimation of the design loads. 5. Of late foreign companies are devoting more attention to a study of unsteady processes in the equipment of pumped-storage plants which decisively affect the reliability and life of its operation. 6. Leading laboratoires of the world are showing great interest in refining formulas for converting from a model to the full-scale object when determining the effectiveness of operation of the hydraulic machine and when evaluating its cavitation parameters. This increase in the role of the scale effect can be explained by the considerable enlargement of the machines with their maximum boosting, and also by complication of the schemes of the installations which hampers the conduct of full-scale investigations. 7. The inexpensive and handy acoustic method, the reliability of which has been confirmed by many methodological laboratory investigations, is gaining greater recognition in cavitation investigations.