GB2452058A

GB2452058A - Fluid power generator

Info

Publication number: GB2452058A
Application number: GB0716396A
Authority: GB
Inventors: Gurcharan S Chana
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-08-22
Filing date: 2007-08-22
Publication date: 2009-02-25
Anticipated expiration: 2027-08-22
Also published as: GB2452058B; GB0716396D0

Abstract

A turbine for a fluid power generator with a turbine surface (26) defining a substantially helical flow path (24), which turbine is rotatably mounted about a main axis of the helical flow path (24) and further with a first vane (30) extending from the turbine surface (26) and spaced from a main axis of the helical flow path (24), such that in use flow of a fluid in the substantially helical flow path (24) flows past the first vane (30) to apply a torque to the turbine (12) about the main axis.

Description

1 2452058 Our Reference P308105GB Fluid power generator The present invention is concerned with power generation, and in particular with power generation using a moving fluid.

Moving fluids (gases and liquids) comprise kinetic energy which can be converted into electrical power with the use of electrical generators connected to devices such as wind and water turbines. Extracting energy from moving fluids is useful, as many naturally occurring events cause fluid to move; e.g. tidal flows, and gravity fed water flows (such as rivers). These fluid flows are seen as sources of renewable energy, and conversion of their kinetic energy into useful electrical energy produces few harmful side effects (compared to say, burning fossil fuels).

Water turbines are known which are able to convert kinetic energy in water into kinetic energy in a rotor which can then be converted into electrical energy using generators. Such turbines comprise surfaces onto which the moving fluid impinges thereby causing motion (i.e. rotation) of the turbine to be transmitted to the generator.

It is an object of the present invention to provide an improved fluid power generator.

According to a first aspect of the present invention there is provided a turbine for a fluid power generator comprising a turbine surface defining a substantially helical flow path, which turbine is rotatably mounted about a main axis of the helical flow path and further comprising a first vane extending from the turbine surface and spaced from a main axis of the helical flow path, such that in use flow of a fluid in the substantially helical flow path flows past the first vane to apply a torque to the turbine about the main axis.

There can be provided a turbine assembly for a fluid power generator comprising a turbine according to the first aspect of the invention and a stationary duct at least partially surrounding an axial cross section of the turbine.

There can be provided a fluid power generator comprising a turbine according to the first aspect or a turbine assembly, further comprising an electrical generator being operably connected to the turbine to generate electricity in use.

A fluid power generator will now be described in detail and with reference to the accompanying figures in which: Figure 1 is a side partial section view of a fluid power generator in accordance with a first embodiment of the present invention; Figure 2 is an end partial section view of the fluid power generator of figure 1; Figure 3 is an end partial section view of a second embodiment of a fluid power generator; Figure 4a is a section of a first embodiment of a vane; Figure 4b is a section of a second embodiment of a vane; Figure 4c is a section of a third embodiment of a vane; Figure 4d is a section of a fourth embodiment of a vane; and Figure 5 is side partial section view of a fluid power generator in accordance with a third embodiment of the present invention.

Referring to figures 1 and 2, a fluid power generator 10 comprises a fluid turbine assembly 12 and an electrical power generator 14. Fluid turbine assembly 12 comprises a turbine 16 and a duct 18.

Turbine 16 comprises a helical screw 20 mounted to a shaft 22. The helical screw 20 defines a helical channel 24 through which fluid may flow. The helical screw 20 also defines a helical periphery 26. The shaft 22 is rotatably mounted about a main axis X in a pair of bearings 28.

Vanes 30 extend between facing surfaces of a surface the helical screw 20 proximate the helical periphery 26 at a common radius about the axis X and are evenly spaced circumferentially. In fluid power generator 10, the vanes 30 are of uniform cross-sectional thickness, parallel to the axis X and at an angle A to the radial direction (as shown in figure 2). Angle A is preferably in the range 0 to 90 degrees.

Duct 18 comprises a circular cross-section wall 32 surrounding the turbine assembly 12. A plurality of spokes 34 are positioned at either end of the wall 32 and connect wall 32 to a pair of hubs 36 in which bearings 28 are mounted.

Electrical power generator 14 comprises a generator unit 38, a driven pulley 40 and a drive pulley 42. The drive pulley and the driven pulley are connected by a belt or chain drive 44 to transfer torque.

In use, the fluid power generator 10 is located into a fluid flow 2, in the direction 4.

The fluid enters the duct 18 and contacts the helical screw 20. As it does so, the fluid flow direction changes to follow the helical channel 24. The now helical flow 6 impinges onto the vanes 30 as shown in figure 2, producing a torque and rotating the helical screw 20 and shaft 22 about axis X in the bearings 28. As the helical flow continues to progress along the helical channel 24, and it follows that a flow from the axis X in the direction of the helical periphery 26 can be produced past the vanes 30; i.e. a flow with a significant radial component.

Fluid power generator 100, shown in figure 3, is substantially similar to fluid power generator 10 and analogous components are numbered 100 greater. A difference lies in the cross-sectional shape of the vanes 130, which are shaped as aerofoil and angled with the direction of lift L oriented at an angle B to the radial direction from axis X. Therefore as the flow 106 progresses, it flows over vanes 130 and each produces lift in direction L. The angle B is set such that the line of action of L is offset from axis X and as such a torque is produced to rotate the helical screw 20 and shaft 22 about axis X in the bearings 28. It will be appreciated that this arrangement reduces loss of energy through friction.

Various cross-sectional profiles of blade are available; see for example figures 4a to 4d. Fig 4a shows a flat plate profile 200 for impingement. Figure 4b shows a concave arrangement 202 similar to that used in fluid power generator 10. Figure 4c shows an aerofoil profile 204 similar to that used in fluid power generator 100. Figure 4d shows a more basic aerofoil profile 206.

Fluid power generator 300, shown in figure 5 is similar to fluid power generator 10 with the addition of a convergent entry nozzle 350. Convergent entry nozzle 350 accelerates the flow of the fluid 302 as it enters the turbine assembly 312.

Claims

Claims 1. A turbine for a fluid power generator comprising a turbine surface defining a substantially helical flow path, which turbine is rotatably mounted about a main axis of the helical flow path and further comprising a first vane extending from the turbine surface and spaced from a main axis of the helical flow path, such that in use flow of a fluid in the substantially helical flow path flows past the first vane to apply a torque to the turbine about the main axis.
2. A turbine for a fluid power generator according to claim I in which first vane comprises an impingement surface oriented such that flow of the fluid impinges on said surface to apply the torque.
3. A turbine for a fluid power generator according to claim 2 in which the impingement surface is convex.
4. A turbine for a fluid power generator according to claim 1 in which first vane is shaped to act as an aerofoil such that flow of the fluid past the first vane produces lift at the vane to apply the torque.
5. A turbine for a fluid power generator according to any preceding claim in which the first vane is of uniform thickness in cross section.
6. A turbine for a fluid power generator according to any preceding claim in which the first vane spans two facing surface portions of the turbine surface.
7. A turbine for a fluid power generator according to claim 1 in which the substantially helical flow path is defined on a screw.
8. A turbine for a fluid power generator according to claim 7 in which the vane extends from a first thread portion of the screw to a second thread portion of the screw.
9. A turbine for a fluid power generator according to any preceding claim in which the first vane extends / spans substantially in the direction of the main axis.
10. A turbine for a fluid power generator according to any preceding claim in which the first vane is substantially parallel to the main axis.
11. A turbine for a fluid power generator according to any preceding claim in which the first vane runs substantially the entire length of the turbine.
12. A turbine for a fluid power generator according to any preceding claim comprising a plurality of vanes substantially similar to the first vane and circumferentially spaced around the main axis.
13. A turbine assembly for a fluid power generator comprising a turbine according to any preceding claim and a stationary duct at least partially surrounding an axial cross section of the turbine.
14. A turbine assembly according to claim 13 in which the duct completely surrounds an axial cross section of the turbine.
15. A turbine assembly according to claim 14 in which the duct completely surrounds all axial cross sections of the turbine.
16. A turbine assembly according to any of claims 13 to 15 further comprising a convergent nozzle at a first end of the duct.
17. A turbine assembly according to any of claims 13 to 16 in which the duct comprises a first bearing mounting means extending from a duct outer surface to a first hub positioned substantially at a first end of the duct and at the main axis and the turbine is rotatably mounted at the further hub.
18. A turbine assembly according to claim 17 in which the duct further comprises a further bearing mounting means extending from a duct outer surface to a further hub positioned substantially at an opposite end of the duct to the first end and at the main axis and the turbine is additionally rotatably mounted at the further hub.

S
19. A fluid power generator comprising a turbine according to any of claims 1 to 12 or a turbine assembly according to any of claims 13 to 18, further comprising an electrical generator being operably connected to the turbine to generate electricity in use.
20. A fluid power generator according to claim 19 in which a main shaft of the electrical generator is offset from the main axis and the electrical generator and the turbine are connected by a belt / chain drive.
21. A turbine as herein described and / or with reference to the accompanying figures.
22. A turbine assembly as herein described and / or with reference to the accompanying figures.
23. A fluid power generator as herein described and / or with reference to the accompanying figures.