Hydraulic turbine
Disclosed herein are linear hydraulic turbines in which the linear machine converts the majority of available energy in the flowing water into useful torque directly in the runner, leaving the outflow with very little velocity.
1. A turbine, comprising:
a plurality of blades configured to travel a path around a first axis and a second axis parallel to the first axis, the path comprising:
a first segment from the second axis to the first axis, the first segment being a first stage of the turbine,
a second segment around the first axis,
a third segment from the first axis to the second axis, the third segment being a second stage of the turbine, and
a fourth segment around the second axis;
wherein each of the plurality of blades have an orientation relative to a vector of blade travel resulting in a blade negative stagger angle in the first stage of the turbine, and a blade positive stagger angle in the second stage of the turbine.
2. The turbine of claim 1 , wherein the first segment is substantially linear, the second segment is substantially arc-shaped, the third segment is substantially linear, and the fourth segment is substantially arc-shaped.
3. The turbine of claim 1 , wherein the first axis and the second axis are spaced along a vertical plane.
4. The turbine of claim 1 , wherein each of the plurality of blades is connected at a first end to a moving structure and at a second end to a second moving structure to travel the path.
5. The turbine of claim 4 , wherein the moving structure and the second moving structure are belts.
6. The turbine of claim 1 , wherein each of the plurality of blades is connected to a moving structure at its mid-span, such that ends of each blade are cantilevered.
7. A turbine, comprising:
a plurality of blades configured to travel a path around a first axis and a second axis parallel to the first axis, the path comprising:
a first segment from the second axis to the first axis, the first segment being a first stage of the turbine,
a second segment around the first axis,
a third segment from the first axis to the second axis, the third segment being a second stage of the turbine, and
a fourth segment around the second axis;
wherein each of the plurality of blades have an orientation relative to a vector of blade travel resulting in a blade negative stagger angle in the first stage of the turbine, and a blade positive stagger angle in the second stage of the turbine, and
wherein the first axis and the second axis are spaced along a horizontal plane.
8. A turbine, comprising:
a plurality of blades attached to a structure and traveling a path comprising a first stage substantially linear portion, a first substantially arc-shaped portion, a second stage substantially linear portion, and a second substantially arc-shaped portion;
a plurality of stationary guide vanes arranged in a space enclosed by the structure; and
a shroud positioned adjacent to the first substantially arc-shaped portion and conforming to a curvature of the first substantially arc-shaped portion,
the turbine being configured to receive a free jet working fluid, the free jet working fluid having a flow pattern through the turbine in a plane substantially perpendicular to the first stage and the second stage,
wherein each of the plurality of blades have an orientation relative to a vector of blade travel resulting in a blade negative stagger angle in the first stage substantially linear portion, and a blade positive stagger angle in the second stage substantially linear portion.
9. The turbine of claim 8 , wherein the free jet working fluid enters the turbine at an angle less than or equal to 45 degrees with respect to a line of blade travel in the first stage.
10. The turbine of claim 8 , wherein a maximum absolute velocity of the free jet working fluid occurs prior to entering the first stage.
11. The turbine of claim 8 , wherein the plurality of blades at the first stage and the second stage are configured to engage the free jet working fluid in an impact-free manner.
12. The turbine of claim 8 , wherein the flow path of the free jet working fluid leaving the second stage exits in a direction substantially perpendicular to a line of travel of the second stage of blades.
13. The turbine of claim 8 ,
wherein the shroud has a first end positioned at a location approximately equal to a beginning of the first substantially arc-shaped portion, and
wherein the shroud has a second end positioned at a location approximately coincident with a trailing edge of a first interior guide vane.
14. The turbine of claim 8 , wherein the turbine has a clearance between tips of the plurality of blades moving around the second arc-shaped path and a closest stationary wall,
wherein the clearance is at least approximately 1 blade chord length.
15. The turbine of claim 8 , wherein the turbine is configured to receive a free jet working fluid from an open channel sluice.
16. A turbine, comprising:
a plurality of blades attached to a structure and traveling a path comprising a first stage substantially linear portion, a first substantially arc-shaped portion, a second stage substantially linear portion, and a second substantially arc-shaped portion;
a plurality of stationary guide vanes arranged in a space enclosed by the structure;
a shroud positioned adjacent to the first substantially arc-shaped portion and conforming to a curvature of the first substantially arc-shaped portion; and
a movable structure configured to have a deflection position and a non-deflection position,
the turbine being configured to receive a free jet working fluid, the free jet working fluid having a flow pattern through the turbine in a plane substantially perpendicular to the first stage and the second stage,
wherein when the movable structure is in the deflection position, the movable structure redirects the free jet working fluid away from the plurality of blades.
17. A turbine, comprising:
a plurality of blades attached to a structure and traveling a path comprising a first stage substantially linear portion, a first substantially arc-shaped portion, a second stage substantially linear portion, and a second substantially arc-shaped portion;
a plurality of stationary guide vanes arranged in a space enclosed by the structure; and
a shroud positioned adjacent to the first substantially arc-shaped portion and conforming to a curvature of the first substantially arc-shaped portion,
the turbine being configured to receive a free jet working fluid, the free jet working fluid having a flow pattern through the turbine in a plane substantially perpendicular to the first stage and the second stage,
wherein the turbine is enclosed by a chamber, the chamber being sealed and having a control valve,
wherein the free jet working fluid leaving the second stage of the turbine exits the chamber through a draft chamber, the draft chamber having an outlet that is hydraulically sealed to an outlet fluid body,
wherein movement of the free jet working fluid through an enclosed air space in the chamber entrains bubbles of the surrounding atmosphere,
wherein momentum of free jet working fluid evacuates the entrained bubbles of the surrounding atmosphere from the chamber, and
wherein the control valve is configured to allow an amount of air to enter the chamber to maintain a desired elevation of suction head inside the draft chamber without allowing the outlet fluid body to contact the plurality of blades.
18. A turbine system comprising:
a turbine comprising:
a plurality of blades attached to a structure and traveling a path comprising a first stage substantially linear portion, a first substantially arc-shaped portion, a second stage substantially linear portion, and a second substantially arc-shaped portion;
a plurality of stationary guide vanes arranged in a space enclosed by the structure; and
a shroud positioned adjacent to the first substantially arc-shaped portion and conforming to a curvature of the first substantially arc-shaped portion, wherein each of the plurality of blades have a fixed orientation relative to a vector of blade travel, and wherein the plurality of blades are configured such that their curvature is asymmetric about the path of travel; and
a confined flow nozzle having a rectangular cross-section, the confined flow nozzle being configured to provide a free jet working fluid to the turbine, the free jet working fluid having a flow pattern through the turbine in a plane substantially perpendicular to the first stage and the second stage.
19. A turbine system comprising:
a turbine comprising:
a plurality of blades attached to a structure and traveling a path comprising a first stage substantially linear portion, a first substantially arc-shaped portion, a second stage substantially linear portion, and a second substantially arc-shaped portion;
a plurality of stationary guide vanes arranged in a space enclosed by the structure; and
a shroud positioned adjacent to the first substantially arc-shaped portion and conforming to a curvature of the first substantially arc-shaped portion;
a confined flow nozzle having a rectangular cross-section, the confined flow nozzle being configured to provide a free jet working fluid to the turbine, the free jet working fluid having a flow pattern through the turbine in a plane substantially perpendicular to the first stage and the second stage,
wherein the confined flow nozzle comprises two opposing movable panels configured to vary a cross-sectional area of the free jet working fluid.
20. The turbine system of claim 19 , wherein an orientation of the panels results in a free jet working fluid that varies substantially in its width, but whose cross-section is substantially unaltered;
wherein the free jet working fluid intersects the plurality of blades in substantially the same manner regardless of the width of the jet.
21. The turbine system of claim 19 , wherein an orientation of the panels results in a free jet working fluid that substantially maintains its width, but whose cross-section height varies.