US20130343891A1

US20130343891A1 - Spiral screw fluid turbine having axial void

Info

Publication number: US20130343891A1
Application number: US13/913,014
Authority: US
Inventors: Uppala RAJAKARUNA; Bushitha Sehan GEEKIYANAGE
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-06-07
Filing date: 2013-06-07
Publication date: 2013-12-26
Also published as: AU2013271391A1; EP2909475A4; CN104520579A; WO2013185068A1; EP2909475A1

Abstract

A spiral turbine includes an axle configured to rotate and one or more spiral blades coupled to the axle by one or more support connections. Each spiral blade is formed around and outside of a conical inner space which is coaxial with the axle.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

Priority is claimed to U.S. provisional patent application No. 61/656,851, filed Jun. 7,2012, the disclosure of which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The field of the present invention relates to turbine blades, and more specifically to turbine blades for generation of electric energy.

BACKGROUND OF THE INVENTION

Turbine blades are generally designed to capture energy from flowing fluids, such as flowing water or air. Various designs of wind mills and water turbines exist today and are used in many regions around the world for producing electric power through rotation powered by the flow of fluids, most commonly air or water.
Many proposals have been made for gathering electricity from tidal and other water flows, using hydrokinetic energy generation. Initial proposals for hydrokinetic energy genera (ion use turbine blades that are able to rotate under pressure from the flow of water. Generally four types of hydrokinetic devices have been tested in recent years: horizontal axis turbines, vertical axis turbines, oscillating hydrofoils, and venturi systems. The last of these, the venturi systems, are generally used to accelerate water through a “choke system” to create a pressure drop that can be used to drive turbines.
For example, a helical turbine generator is known from U.S. Pat. No. 6,036,443 to Gorlov, which discloses a helical turbine having airfoil-shaped blades that are arranged in a spiral about a central shaft. Fluid passing through the turbine transversely to the axis of rotation induces rotation of the turbine. An array of the turbines can be provided to increase power output. Another type of helical turbine is described in U.S. Pat. No. 4,384,212 to Lapeyre. This helical, turbine has a horizontally mounted helical member that is buoyant, so that when it is used on the surface of water that has waves traversing the length of the helical member, the buoyancy of the helical member interacting with the waves causes the helical member to rotate about its axis, thereby translating wave energy in to electrical energy.
It is now known that energy generating turbines can create significant issues for marine life, which can be harmed by the rotating turbine blades. So far, the various known proposals to reduce the potential harm to marine life only serve to add to the expense of the turbine and the expense of the installation.
Additional expenses introduced by many previous hypokinetic energy generation proposals are seen by inclusion of rigid housings or anchoring systems in order to maintain placement of the energy generating system.

SUMMARY OF THE INVENTION

The present invention is directed toward a spiral turbine having one or more spiral blades connected to an axle.
In a first separate aspect, of the present invention, the spiral, turbine includes an axle configured to rotate, and the one or more spiral blades are coupled to the axle by one or more support connections. Each spiral blade is formed around and outside of a conical inner space which is coaxial with the axle. Several options are available for the spiral blades: each may be secured to the axle at the narrow end of the conical inner space; each may be segmented; each may be weight balanced around the axle; each may have a flat or a curved profile; each may have a wider profile at the wide end of the conical inner space than at the narrow end; and each blade may have a leading edge spaced apart from the perimeter of the conical inner space. As another option, for configurations in which two or more spiral blades are included, the blades may be symmetrically disposed around the axle.
In a second separate aspect of the present invention, an electricity generating system includes at least one electricity generator having a rotational input and an array of spiral turbines. Each spiral turbine includes an axle operatively coupled to the rotational input and one or more spiral blades coupled to the axle by one or more support connections. Each spiral blade is formed around and outside of a conical inner space which is coaxial with the axle. Optionally, two or more of the spiral turbines may be operatively coupled to the rotational input in series or in parallel.
In a third separate aspect of the present invention, any of the foregoing aspects may be employed in combination.
Accordingly, an improved spiral screw turbine is disclosed. Advantages of the improvements will be apparent from the drawings and the description of the preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description of the exemplary embodiments, are to be read in conjunction with the appended drawings. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown in the following figures:

FIG. 1 is a side view of a three blade spiral screw turbine.

FIG. 2 is an isometric view of a three blade spiral screw turbine blade.

FIG. 3 is a schematic view of a two blade spiral screw turbine blade and the pseudo cone formed in the void within the blades.

FIG. 4 is a side view of a truncated three blade spiral screw turbine blade.

FIG. 5 is s side view of a single blade spiral screw turbine blade, shown without a center axle and axle attachments.

FIG. 6 illustrates a power generator array using multiple spiral screw turbine blades.

FIG. 7 illustrates another array using multiple spiral screw turbine blades.

FIG. 8A is a perspective schematic view of a two blade spiral screw design.

FIG. 8B is a side schematic view of the two blade spiral screw design of FIG. 8A as viewed from transverse to the center axis of the spiral screw.

FIG. 8C is an end schematic view of the two blade spiral screw design of FIG. 8A as viewed from the wide end of the spiral screw.

FIG. 9 illustrates yet another array using multiple spiral screw turbine blades.

DETAILED DESCRIPTION OF THE INVENTION

The description of illustrative embodiments according to principles of the present invention is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. In the description of embodiments of the invention disclosed herein, any reference to direction or orientation is merely intended for convenience of description and is not intended in any way to limit the scope of the present invention. Relative terms such as “lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “up,” “down,” “left,” “right,” “top” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description only and do not require that the apparatus be constructed or operated in a particular orientation unless explicitly indicated as such. Terms such as “attached,” “affixed,” “connected,” “coupled,” “interconnected,” and similar refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. Moreover, the features and benefits of the invention are illustrated by reference to the preferred embodiments. Accordingly, the invention expressly should not be limited to such preferred embodiments illustrating some possible non-limiting combinations of features that may exist alone or in other combinations of features; the scope of the invention being defined by the claims appended hereto.
Turning in detail to the drawings, FIG. 1 illustrates a spiral turbine is shown having three spiral blades 1 coupled to a center axle 3 by multiple support connections 4, each of which is shown as a lateral shaft extending from each respective blade 1 to the center axle 3. In the embodiment shown, each blade 1 is also coupled to the center axle 3 directly at the narrow end 19. FIG. 5 illustrates a single blade 1 without the center axle or the support connections, and a spiral turbine may be configured with a single blade. As discussed below, this direct connection of the blades 1 to the center axle 3 may be omitted in certain embodiments. The total spiral blade arrangement is balanced to and symmetrical along the axle to enable the turbine blades to rotate without inducing wobbles in the turbine during rotation. The addition of one or more weights (not shown) to one or more of the spiral blades 1 may be necessary in order to achieve rotational balance for the entire turbine. In the embodiment shown, each blade 1 has a flat cross-sectional profile, with the profile being wider at the wide end 18 of the spiral blades 1 than at the narrow end 19. Alternatively, the spiral blades 1 may have a curved profile, with the curvature having the centerline of each blade placed further away from the center axle 3 than either the leading edge 7 or the trailing edge 6 of each blade 1, so that the inner surface 2 of the blade 1 has a concave curvature that is open toward the center axle 3. As another alternative, the inner surface 2 of each blade 1 may have a flat or curved profile, whereas the outer surface of each blade 1 may have a different profile. The cross-sectional of the blades may be varied, or even uneven in shape, in order to maximize the energy captured by the turbine, while still including the conical Inner space as an axial void (also referred to as a “pseudo cone”), depending upon the intended operating conditions of the turbine.
At the wide end 18 of the spiral blades 1, each blade has a truncated end 5, which may take any shape or angle. Optionally, the truncated ends 5 may be merged into a support connection that would extend laterally toward the center axle 3.
At the narrow end 19 of the spiral blades 1, the center axle 3 is connected to a generator 16 through a shaft extension 10. The spiral blades 1 are weight balanced, on the opposite side of the generator 16 by a balancing weight 9, which is affixed to the generator 16 by a support arm 11. This balancing weight may be eliminated, depending upon the particular design of the turbine. The generator 16 is mounted to a support column 8 through a horizontal pivot connection 14 and a support bar 13. Although in the embodiment shown, only a single turbine is supported by the support column 8, multiple turbines may be coupled to and supported by a single support column, depending upon the particular design specifications.
The spiral turbine as shown is constructed so that fluid flow enters from the wide end 18 of the spiral blades 1 and flows toward the narrow end 19 of the spiral blades 1, in the direction shown by the arrow 20. As described in greater detail below, in certain embodiments, the leading edges 7 of the blades 1 are spaced apart from the conical inner space (see FIG. 3) about which the blades wind, where the trailing edges 6 of the blades 1 are not spaced apart from the conical inner space.
FIG. 2 illustrates an embodiment of three spiral blades 1. In this view, certain features of the spiral blades 1 are more clearly shown. Each blade 1 is connected to the center axle 3 by two posts forming the support connections 4, and each blade 1 is connected to the center axle 3 at the narrow end 19.
The conical inner space formed by spiral blades 1 is illustrated in FIG. 3, which depicts two spiral blades 1 formed around and outside of the conical inner space 23. The conical inner space 23 is defined by intersections with each blade. In the embodiment shown, the trailing edge 6 of each spiral blade 1, which are symmetrical to each other, defines the conical inner space 23, from the wide end 18 through to the narrow end 19. The leading edge 7 of each blade is spaced apart from the periphery of the conical inner space 23 defined in this manner. With this configuration, as shown, the trailing edge 6 of each spiral blade 1 will generally be closer to the center axle 3 than the nearest point on the leading edge 7 of the spiral blade 1.
Spiral blades 1, which are truncated near the narrow end 19, are shown in FIG. 4. In certain embodiments, it may be desirable to leave the narrow end 19 more open, with the blades 1 not extending all the way to couple with the center axle 3. Depending upon the operating conditions, such a configuration is expected to provide an advantage. Alternatively, the spiral blades may be non-contiguous running from the wide end to the narrow end. Such a configuration would reduce the weight of the spiral turbine, and depending upon the operating conditions, may still provide a desired energy output. As another alternative, the weight of the blades may be reduced by having holes or perforations in the blades. Having the spiral blades designed in any of these manners enable changing the size of the turbine blade front radius (R), and/or the blade length (L), and/or the blade width (i.e. adjusting the blade surface exposed to fluid passing through the pseudo cone), so that the weight and operational parameters of the turbine can configured to maximize energy production for different operating conditions.
FIGS. 8A-8C show configuration details of spiral blades with respect, to the conical inner space formed for certain embodiments. The cone angle of the pseudo cone (θ₁) can be varied between about 5°-60°, depending upon the intended operating conditions, to help maximize energy output. Also, the angle between the centerline of the pseudo cone and the spiral blade (θ₂) may be varied between about 5°-90°, depending upon the intended operating conditions, to help maximize energy output. In addition, the spiral blade angle (θ₂) may vary along the length of the blade itself. The angle between the radius of the pseudo cone and spiral blade (θ₃) may also be varied between about 5°-90°, depending upon the intended operating conditions, to help maximize energy output. Any of the aforementioned variables may be adjusted singly or in combination to account for fluid flow rate, turbulence, and other operational conditions to better enable maximizing energy output based on the size of the turbine desired for the application.
In a different configuration, the angle between the radius of the pseudo cone surface and the spiral blade (θ₃) may vary between about 90°-180°, then the spiral turbine is configured for fluid flow in the direction from the narrow end to the wide end.
FIG. 6 illustrates three spiral turbines 1 coupled in parallel to a single power generator 16, which is supported by a support column 8. Each turbine 1 is coupled to the generator 16 through one or more universal joints 12 and transfer shafts 29. This configuration allows multiple spiral turbines to generate energy through a single generator.
FIG. 7 illustrates five spiral turbines coupled together to generate power through one or more generators (not shown). In this configuration, two of the spiral turbines 31, 32 are directly coupled in series through universal joints 12 and transfer shafts 29, and two other of the spiral turbines 33, 34 are coupled in parallel through universal joints 12 and transfer shafts 29, and then operationally coupled in series to the other two spiral turbines 31, 32 through a universal joint 12 and transfer shafts 29. A fifth spiral turbine 35 is connected in parallel to ail other spiral turbines shown 31, 32, 33, 34 in the same manner. This embodiment exemplifies the versatility of coupling spiral turbines together to suit a particular application and/or operating conditions. The generators, whether single or multiple, may be connected to a main power storage or a power distribution center.
FIG. 9 shows an array of spiral turbines 41 within a support frame 42 Although the generators are not shown, with this configuration, one generator may be included for every spiral turbine, or two or more of the turbines may be operationally coupled into a single generator through universal joints and transfer shafts. The generators, whether single or multiple, may be connected to a main power storage or a power distribution center.
Spiral turbines enable transforming rotational energy into electric power by rotating an electric generator. This arrangement may be self orienting, to automatically expose the wide end to a fluid current, if the center axle is attached by a pivoting bearing to a support column, and the center axle couples to a generator through a universal joint.
Spiral turbines may be used in a hydrokinetic energy converter, specifically one that can be used in a tidal flow or river flow, it should be appreciated that spiral turbines may be incorporated into any other kind of hydrokinetic devices and generators, and even to wind generators. Spiral turbines may be operated entirely below the surface water level or partially above the surface water level, with part of the turbine in the air above the surface of the water. Spiral turbines may also be used in a pressurized fluid flow to maximize the capture of energy. The fluid flow may be pressurized using cylindrical tubing having narrower conical shape in one end, such as a venturi configuration. Such spiral turbines may also be used as a propeller connected to a hub and rotational power source. A spiral turbine may also be attached to a fast moving object to generate power from relative fluid flow.
While the invention has been described with respect to specific examples including presently preferred modes of carrying out the invention, those skilled in the art will appreciate that there are numerous variations and permutations of the above described systems and techniques. It is to be understood that other embodiments may be utilized and structural and functional modifications may be made without departing from the scope of the present invention. Thus, the spirit and scope of the invention should be construed broadly as set forth in the appended claims.

Claims

What is claimed is:

1. A spiral turbine comprising:

an axle configured to rotate;

one or more spiral blades coupled to the axle by one or more support connections, each spiral blade being formed around and outside of a conical inner space which is coaxial with the axle.

2. The spiral turbine of claim 1, wherein the one or more spiral blades comprises at least two of the spiral blades, the blades being symmetrically disposed around the axle.

3. The spiral turbine of claim 1, wherein each spiral blade converges on and couples to the axle at a narrow end of the conical inner space.

4. The spiral turbine of claim 1, wherein each spiral blade is segmented.

5. The spiral turbine of claim 1, wherein the one or more spiral blades are weight balanced around the axle.

6. The spiral turbine of claim 1, wherein each spiral blade is wider at a wide end of the conical inner space than at a narrow end of the conical inner space.

7. The spiral turbine of claim 1, wherein each spiral blade has a leading edge spaced apart from a perimeter of the conical inner space.

8. The spiral turbine of claim 1, wherein each spiral blade has one of a flat profile or a curved profile.

9. The spiral turbine of claim 1, further comprising an electricity generator operatively coupled to the axle.

10. The spiral turbine of claim 9, wherein the axle is operatively coupled to the electricity generator through a rotatable universal joint.

11. An electricity generating system comprising:

at least one electricity generator having a rotational input;

an array of spiral turbines, each turbine comprising:

an axle operatively coupled to the rotational input;

12. The spiral turbine of claim 11, wherein the one or more spiral blades of each turbine comprises at least two of the spiral blades, the blades being symmetrically disposed around the axle.

13. The spiral turbine of claim 11, wherein for at least one of the turbines, each spiral blade converges on and couples to the axle at a narrow end of the conical inner space.

14. The spiral turbine of claim 11, wherein for at least one of the turbines, each spiral blade is segmented.

15. The spiral turbine of claim 11, wherein tor at least one of the turbines, each spiral blade is wider at a wide end of the conical inner space than at a narrow end of the conical inner space.

16. The spiral turbine of claim 11, wherein for at least one of the turbines, each spiral blade has a leading edge spaced apart from a perimeter of the conical inner space.

17. The spiral turbine of claim 11, wherein for at least one of the turbines, each spiral blade has one of a flat profile or a curved profile.

18. The spiral turbine of claim 11, wherein each axle is operatively coupled to one of the electricity generators through a rotatable universal joint.

19. The system of claim 11, wherein at least two of the spiral turbines are operatively coupled to the rotational input in series.

20. The system of claim 11, wherein at least two of the spiral turbines are operatively coupled to the rotational input in parallel.