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A hydraulic turbine with increased power capacities for new or existing hydroelectric installations. The turbine has a larger axial runner wheel and a reshaped runner ring peripherally extending around the runner wheel. A draft tube with a larger elbow section extends on a downstream side of the run

A hydraulic turbine with increased power capacities for new or existing hydroelectric installations. The turbine has a larger axial runner wheel and a reshaped runner ring peripherally extending around the runner wheel. A draft tube with a larger elbow section extends on a downstream side of the runner ring. A water supply port extends around a rotation axis of the runner wheel on an upstream side of the runner ring, and is adapted to produce a centripetal water flow swirling around the rotation axis of the runner wheel. A turning passageway extends between the water supply port and the runner ring, and is adapted to guide and redirect the centripetal water flow in a substantially axial direction of the runner wheel. An axial distributor extends between the turning passageway and the runner ring.

대표청구항 ▼

1. A hydraulic turbine with increased power capacities, comprising:an axial runner wheel having a rotation axis; a runner ring peripherally extending around the runner wheel; a draft tube extending on a downstream side of the runner ring; a water supply port extending around the rotation axis of the

1. A hydraulic turbine with increased power capacities, comprising:an axial runner wheel having a rotation axis; a runner ring peripherally extending around the runner wheel; a draft tube extending on a downstream side of the runner ring; a water supply port extending around the rotation axis of the runner wheel on an upstream side of the runner ring, and adapted to produce a substantially centripetal water flow swirling around the rotation axis of the runner wheel; a turning passageway extending between the water supply port and the runner ring, and adapted to guide and redirect the centripetal water flow in a substantially axial direction of the runner wheel; an axial distributor extending between the turning passageway and the runner wheels; and a bottom pit liner peripherally extending around the axial distributor and the runner ring; and wherein the water supply port comprises a stay ring next to the turning passageway and a conical support ring attaching a lower part of the water supply port to the stay ring and to the bottom pit liner. 2. The hydraulic turbine according to claim 1, wherein the stay ring extends above the axial distributor.3. The hydraulic turbine according to claim 1, wherein the stay ring comprises a number of stay vanes distributed around the rotation axis of the runner wheel, near the turning passageway.4. The hydraulic turbine according to claim 3, wherein the stay vanes have a height close to a smallest diameter of the water supply port.5. The hydraulic turbine according to claim 3, wherein the number of stay vanes ranges from 12 to 24.6. The hydraulic turbine according to claim 1, wherein the axial distributor comprises adjustable guide vanes projecting around the rotation axis of the runner wheel.7. The hydraulic turbine according to claim 6, wherein the guide vanes have an adjustment pitch range between 0 to 20 degrees with respect to a rotation plane of the runner wheel.8. The hydraulic turbine according to claim 6, wherein the axial distributor further comprises means for controlling the guide vanes in a space limited by the bottom pit liner and a ring of the axial distributor.9. The hydraulic turbine according to claim 1, further comprising a shaft supporting the runner wheel in the runner ring, and a guide bearing axially guiding the shaft, the runner wheel extending near the guide bearing.10. The hydraulic turbine according to claim 9, wherein the axial distributor projects around the guide bearing.11. The hydraulic turbine according to claim 1, wherein the runner wheel comprises runner blades slightly inclined with respect to a rotation plane of the runner wheel.12. The hydraulic turbine according to claim 11, wherein the runner wheel is a Kaplan type of wheel.13. The hydraulic turbine according to claim 1, further comprising a turbine head cover having a bottom wall forming an upper wall of the turning passageway.14. The hydraulic turbine according to claim 1, wherein the draft tube has a large elbow section substantially aligned with the rotation axis of the runner wheel and followed by a narrow passage communicating with a sloped and enlarging section.15. The hydraulic turbine according to claim 1, wherein the draft tube has an enlarging discharge ring next to the runner ring.16. The hydraulic turbine according to claim 1, wherein the axial distributor has a peripheral ring which narrows towards the runner wheel to a diameter substantially similar to a diameter of the runner wheel.17. A method of refurbishing an existent hydraulic turbine while increasing power capacities thereof, comprising:removing any original radial distributor of the existent hydraulic turbine to recover axial space under a water supply port of the hydraulic turbine; replacing any original stay vanes and wicket gates of the existent hydraulic turbine by new stay vanes having a greater height with respect to the original stay vanes, combined to a reshaping of the water supply port to accommodate the new stay vanes; using the recovered axial space to replace an original runner wheel with a larger diameter axial runner wheel combined to a reshaping of a runner ring peripherally extending around the axial runner wheel, the axial runner wheel and the runner ring being moved downstream with respect to a level of the original runner wheel; inserting an axial distributor upstream of the axial runner wheel; reshaping a head cover of the existent hydraulic turbine to form a turning passageway between the water supply port and the axial runner wheel, adapted to redirect a centripetal water flow swirling in the water supply port around a rotation axis of the axial runner wheel in a substantially axial direction of the axial runner wheel; and reshaping a draft tube on a downstream side of the runner wheel so that the draft tube has an enlarged elbow section with respect to a narrower original elbow section. 18. The method according to claim 17, wherein the hydraulic turbine has a bottom pit liner peripherally extending around the axial distributor and the runner ring, and the water supply port has a stay ring next to the turning passageway, the method further comprising:attaching a lower part of the water supply port to the stay ring and to the bottom pit liner using a conical support ring. 19. The method according to claim 18, wherein the axial distributor has adjustable guide vanes projecting around the rotation axis of the axial runner wheel, the method further comprising:providing means for controlling the guide vanes in a space limited by the bottom pit liner and a ring of the axial distributor.