Hydraulic turbine

Patent metadata

Field	Value
Publication number	US-10480480-B2
Application number	US-201715655166-A
Country	US
Kind code	B2
Filing date	Jul 20, 2017
Priority date	Jul 25, 2016
Publication date	Nov 19, 2019
Grant date	Nov 19, 2019

Abstract

A hydraulic turbine includes a rotor with a runner, which is concentrically surrounded by a stator, whereby the runner comprises a plurality of runner blades arranged and distributed in a ring around a rotor axis, and each runner blade extends between a runner crown and a runner band; whereby the stator comprises a plurality of guide vanes arranged and distributed in a ring around the rotor axis, and each guide vane extends between an upper stator ring and a lower stator ring; and whereby a predetermined clearance is provided at least between the runner band and the lower stator ring. A substantial reduction of pressure pulsations in the vane-less gap between said runner blades of said runner is achieved by substantially increasing said predetermined clearance.

First claim

What we claim is:

1. A hydraulic turbine, comprising:
a runner comprising a runner crown, a runner band, and a plurality of runner blades extending between the runner crown and the runner band; and
a stator surrounding the runner, the stator comprising an upper stator ring, a lower stator ring, and a plurality of guide vanes extending between the upper stator ring and the lower stator ring,
wherein a crown clearance is defined between the runner crown and the upper stator ring, wherein a first ratio of the crown clearance and a crown radius of the runner crown is greater than or equal to 0.02 so as to minimize pressure pulsations developing in a vane-less gap between the plurality of runner blades of the runner and the plurality of guide vanes of the stator.

2. The hydraulic turbine according to claim 1 , further comprising:
a band clearance between the runner band and the lower stator ring,
wherein a second ratio is defined between the band clearance and a second radius of the runner band.

3. The hydraulic turbine according to claim 2 , wherein the second ratio between the band clearance and the second radius is 0.02.

4. The hydraulic turbine according to claim 2 , wherein the second ratio between the band clearance and the second radius is less than 0.02.

5. The hydraulic turbine according to claim 2 , wherein the second ratio between said second clearance and said second radius is greater than 0.02.

6. The hydraulic turbine according to claim 2 , wherein the first ratio is equal to the second ratio.

Assignees

• Ge Renewable Tech

Inventors

• Martinez Lionel
• Houdeline Jean-Bernard
• DARONA Geoffrey
• Beral Claude

Classifications

• F03B3/125 Primary

  Rotors for radial flow at high-pressure side and axial flow at low-pressure side, e.g. for Francis-type turbines · CPC title

• F05B2260/96

  Preventing, counteracting or reducing vibration or noise · CPC title

• F03B11/04 Primary

  for diminishing cavitation or vibration, e.g. balancing · CPC title

• F03B3/02

  with radial flow at high-pressure side and axial flow at low-pressure side of rotors, e.g. Francis turbines {(rotors per se F03B3/125)} · CPC title

• F03B3/12

  Blades; Blade-carrying rotors · CPC title