Reversible pump turbine and guide vane for the reversible pump turbine

A pump-turbine wicket gate comprising plural guide vanes that each comprise a guide vane body having opposite end faces and being pivotable about an axis of rotation via a pivot, the guide vane body having a turbine leading edge facing a direction of turbine flow and a turbine trailing edge facing away from the direction turbine flow,

• wherein the guide vanes of the wicket gate can assume a closed position and an open position and, when in the closed position, respective adjacent guide vanes contact one another along respective closing edges defined contact curves, each guide vane having two flow-guiding surfaces positioned on opposite sides of the axis of rotation and being limited by the opposite end faces, the flow-guiding surfaces forming different flow profiles,
• wherein one flow profile of said different flow profiles is located in a mid-span section of each respective guide vane and has a larger guide vane angle toward the turbine trailing edge than other flow profiles of said different flow profiles in a boundary area of each respective guide vane proximate the opposite end faces, such that, in the open position, the one flow profile in the mid-span section of each respective guide vane creates a larger absolute flow angle (α2) of absolute velocity (C2) of the turbine flow at the guide vane trailing edge in a turbine direction with regard to a related circumferential component of the absolute velocity (C2u) of the turbine flow, than one of the other flow profiles in the boundary area such that the turbine flow in the turbine direction leaves the guide vane body in the mid-span section with a larger flow angle (α2) than in the boundary area, and
• wherein the turbine leading edge, the turbine trailing edge and the closing edge are each curved at least once, and the turbine trailing edge is curved in the mid-span section in a direction that is perpendicular to a plane defined by the axis of rotation and a connecting line between the turbine leading edge and the turbine trailing edge.

A reversable pump-turbine comprising:

• a runner;
• and
• a wicket gate comprising plural adjustable guide vanes that each comprise a guide vane body having opposite end faces and being pivotable about an axis of rotation via a pivot, the guide vane body having a turbine leading edge facing a direction of turbine flow and a turbine trailing edge facing away from the direction turbine flow,
• wherein the guide vanes of the wicket gate can assume a closed position and an open position and, when in the closed position, respective adjacent guide vanes contact one another along respective closing edges defined contact curves, each guide vane having two flow-guiding surfaces positioned on opposite sides of the axis of rotation and being limited by the opposite end faces, the flow-guiding surfaces forming different flow profiles, and
• wherein one flow profile of said different flow profiles is located in a mid-span section of each respective guide vane and has a larger guide vane angle toward the turbine trailing edge than other flow profiles of said different flow profiles in a boundary area of each respective guide vane proximate the opposite end faces, such that, in the open position, the one flow profile in the mid-span section of each respective guide vane creates a larger absolute flow angle (α2) of absolute velocity (C2) of the turbine flow at the guide vane trailing edge in a turbine direction with regard to a related circumferential component of the absolute velocity (C2u) of the turbine flow, than one of the other flow profiles in the boundary area such that the turbine flow in the turbine direction leaves the guide vane body in the mid-span section with a larger flow angle (α2) than in the boundary area.