Use of the waterways of pump turbines for passage of no-load discharges

Conclusions1.The existing methods of passing no-load discharges through turbines of low-head hydrostations do not provide reliable operation of the units owing to a considerable increase of the dynamic loads on the runner blades, other elements of the units, and structural members of the station.2.The proposed method of passing the no-load discharge with the use of dynamic braking according to the given law reduces all dynamic loads with a sufficiently high discharge capacity of the turbine. This is confirmed by full-scale tests of the model. The use of the given method can produce a considerable effect both at existing and newly designed hydrostations.3.The high values of efficiency and minimum dynamic loads on the pump units operating in the turbine regime allow using the impellers of axial-flow pumps as turbines and motors as generators.