Axial or diagonal flow hydro-electric pump-turbine unit - uses forward flow stabiliser of radial blades curved to direct flow towards axial section during pumping

摘要

The pump-turbine unit has successively in the direction of flow during pumping, a turbine wheel, a flow distributor, and a forward flow distributor. The forward flow distributor is made up of a flow stabiliser comprising blades with a curved profile twisted to direct the flow in an axial direction during operation as a pump. The closer circumferential spacing of the blades leads to higher efficiency arising from reduced losses during pumping and the use of a ratio of blade separation to blade length in the order of 0.8 to 1.6, with a preferred range of 0.9 to 1.2, leads to further improvement in efficiency.