ADAPTIVE HYDROELECTRIC TURBINE SYSTEM

Abstract

The present invention provides an adaptive hydroelectric turbine system comprising a base for a hydroelectric turbine or other electrical component, the base having four ground contacting feet, at least one of which is displaceable relative to the remaining of the base such as to ensure that all four feet can contact the seabed to provide improved stability and load bearing capabilities.

Claims

1. An adaptive hydroelectric turbine system comprising a base comprising four ground contacting feet; characterised in that at least one of the feet is displaceable relative to the base.

2. An adaptive hydroelectric turbine system according to claim 1 in which displacement of the at least one foot is in the form of rotation and/or translation of the foot relative to the base.

3. An adaptive hydroelectric turbine system according to claim 1 in which displacement of the at least one foot is facilitated by a coupling about which the at least one foot is displaceable.

4. An adaptive hydroelectric turbine system according to claim 3 in which the coupling comprises a pivot.

5. An adaptive hydroelectric turbine system according to claim 3 in which the coupling comprises a pivotless flexible member.

6. An adaptive hydroelectric turbine system according to claim 5 in which the coupling is operable to undergo plastic deformation in order to facilitate the displacement of the at least one foot.

7. An adaptive hydroelectric turbine system according to claim 3 in which the coupling is adapted to generate a reaction moment responsive to displacement of the at least one foot relative to the base.

8. An adaptive hydroelectric turbine system according to claim 3 in which the coupling is adapted to temporarily enable displacement of the at least one foot relative to the base.

9. An adaptive hydroelectric turbine system according to claim 3 comprising an immobiliser adapted to allow the at least one displaceable foot to be immobilised relative to the base.

10. An adaptive hydroelectric turbine system according to claim 9 in which the immobiliser is defined by the coupling.

11. An adaptive hydroelectric turbine system according to claim 9 in which the immobiliser comprises a curable component.

12. An adaptive hydroelectric turbine system according to claim 1 in which a pair of feet are displaceable relative to the base while being fixed relative to one another.

13. An adaptive hydroelectric turbine system according to claim 1 in which the base comprises a main frame on which at least a pair of the feet are provided, and a subframe on which the at least one displaceable foot is provided, the subframe being displaceable relative to the main frame.

14. An adaptive hydroelectric turbine system according to claim 13 in which the subframe is displaceable about an axis which extends substantially perpendicular to an axis of rotation of a hydroelectric turbine when mounted to the base.

15. An adaptive hydroelectric turbine system according to claim 13 in which the subframe is displaceable about an axis which extends substantially parallel to an axis of rotation of a hydroelectric turbine when mounted to the base.

16. An adaptive hydroelectric turbine system according to claim 13 in which the subframe comprises a cross member pivotably mounted to the main frame and from which subframe the at least one displaceable foot extends.

17. An adaptive hydroelectric turbine system according to claim 1 in which the base comprises four legs, a free end of each leg being defined by one of the ground contacting feet.

18. An adaptive hydroelectric turbine system according to claim 1 comprising a restrictor operable to limit the range of movement of the at least one foot relative to the base.

19. An adaptive hydroelectric turbine system according to claim 18 in which the restrictor is adapted to limit rotational displacement of the at least one foot.

20. A method of deploying a hydroelectric turbine system on a non uniform underwater surface, the method comprising the steps of: lowering a base onto the underwater surface, the base having four ground contacting feet; permitting at least one of the feet to be displaced relative to the base such that all of the feet contact the underwater surface.

21. A method according to claim 20 comprising, in the step of permitting displacement of at least one of the feet, permitting the at least one foot to rotate about an axis.

22. A method according to claim 20 comprising temporarily permitting displacement of at least one of the feet.

23. A method according to claim 20 comprising the step of immobilising the at least one displaceable foot, relative to the base, following contact of all of the feet with the underwater surface.

24. A method according to claim 23 comprising the step of permitting a curable component to set such as to immobilise the at least one displaceable foot.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The present invention will now be described with reference to the accompanying drawings, in which;

[0041] FIG. 1 illustrates a perspective view of a hydroelectric turbine system according to a preferred embodiment of the present invention;

[0042] FIG. 2 illustrates a perspective view of an alternative embodiment of a hydroelectric turbine system according to the present invention;

[0043] FIG. 3 illustrates a front elevation of the hydroelectric turbine system according to the embodiment illustrated in FIG. 1;

[0044] FIG. 4 illustrates a portion of the hydroelectric turbine system of FIG. 3 showing an optional component which may be provided; and

[0045] FIG. 5 illustrates one of four ground contacting feet forming part of the hydroelectric turbine system of the embodiment of either FIG. 1 or FIG. 2.

DETAILED DESCRIPTION OF THE DRAWINGS

[0046] Referring now to FIGS. 1 and 3 to 5 of the accompanying drawings there is illustrated a hydroelectric turbine system according to an embodiment of the present invention, and generally indicated as 10. The hydroelectric turbine system 10 comprises a hydroelectric turbine 12 mounted on a gravity base 14 which is intended to be deployed onto the seabed or other underwater support substrate, in order to support the turbine 12 in a manner which permits the turbine 12 to generate electricity in response to the tidal flow of water through the turbine 12, preferably in a bidirectional manner. The invention is not however intended to be limited to use with a gravity base, although this is the preferred embodiment. The turbine 14 could also be omitted in place of one or more electrical components (not shown) for processing and/or conditioning electricity generated by one or more of the turbines 14, for example when provided in an array, and for the purposes of the following description and claims the term “turbine” should be construed as covering such components.

[0047] While the turbine 12 illustrated is of the type having a shaftless rotor housed within a stator for rotation relative thereto, it will be appreciated from the following description of the configuration and operation of the system 10 that the turbine 12 may be of any other suitable form, for example having a central support shaft, an exposed or non shrouded propeller type rotor, or any other suitable alternative. Similarly it will be appreciated that while the base 14 is shown of a particular configuration of interconnected frame members 20 carrying a pair of uprights 22 between which the turbine 12 may be mounted, it will be appreciated from the following description that the base 14 may be of any other suitable configuration once certain features and functionality are embodied therein, as hereinafter described, and the base 14 may be employed to carry hardware other than the turbine 12, for example one or more components (not shown) involved with the generation, conditioning, transmission, and distribution of electricity.

[0048] The base 14 comprises four ground contacting feet 24, 24′ at least one of which, and in the embodiment illustrated a pair 24 of which are displaceable relative to the remainder of the base 14, and in particular relative to the remaining two fixed feet 24′. The ability of at least one of the feet 24 to be displaced relative to the remainder of the base 14 ensures that all four feet 24, 24′ will contact the seabed or other underwater support substrate, in order to ensure that all four feet 24, 24′ play a load bearing roll in supporting the turbine 12 and providing enhanced stability to the overall system 10, regardless of the presence of off axis or other destabilising effects such as extreme weather events or the like.

[0049] In the embodiment illustrated each foot 24, 24′ is provided on the underside of a corresponding leg 26. In the embodiment illustrated each foot 24, 24′ is defined by an underside of the respective leg 26, although it will be appreciated that one or more of the feet 24, 24′ may be provided as a components separate from the respective leg 26 and optionally articulated relative thereto. In addition one or more of the feet 24, 24′ may include one or more spikes or other ground engaging or penetrating features (not shown) to reduce or eliminate unintended sliding displacement of the base 14 along the seabed or other underwater substrate, for example as illustrated in FIG. 5.

[0050] In the embodiment illustrated the base 14 comprises a main frame 28 comprising a triangular arrangement of the frame members 20 and including a pair of the legs 26, at an underside of each of which is one of the fixed feet 24′. The base 14 further comprises a sub frame 30 comprising a cross member 32 provided at either end of which is one of the legs 26, the underside of each of which defines one of the displaceable feet 24. The sub frame 30 is pivotally or otherwise mounted to the main frame 28, in order to be displaceable relative to the main frame 28, whether through rotation, translation, or a combination thereof. In the preferred embodiment the sub frame 28 is pivotally mounted on a stub axle 34 projecting from an apex of the main frame 28. One or more bearings (not shown) may be provided between the sub frame 30 and main frame 28 in order to reduce friction during relative displacement. The sub frame 30, in the embodiment illustrated, is rotatable about an axis, as defined by the stub axle 34, which extends substantially perpendicular to an axis of rotation of the turbine 12 when mounted to the base 14. It will however be appreciated that the axis displacement of the sub frame 30 may be disposed at any other suitable or desired orientation.

[0051] While it is beneficial to permit the above described displacement of the pair of feet 24 relative to the remainder of the base 14, it is preferable to limit the extent of the displacement in order to ensure that the overall system 10 will remain stable once deployed on the seabed. The base 14 may therefore be provided with a restrictor 36 operable to limit the range of movement, in particular rotation, of the sub frame 30 relative to the main frame 28. While the restrictor 36 may take any suitable form, in the embodiment illustrated the restrictor 36 is in the form of a pair of opposed mechanical stops 38 between which the cross member 32 is captured, and which have a multi faceted surface against which the cross member 32 may come into register as the sub frame 30 rotates from the horizontal position in one or other direction. The stops 38 may be designed to provide a desired range of acceptable displacement, through rotation, of the sub frame 30.

[0052] It is also envisaged that the restrictor 36 could be in the form of a curable component which sets after a predetermined period of time in order to immobilise the sub frame 30 relative to the main frame 28. Thus for example said curable component (not shown) may be designed to allow the system 10 to be deployed onto the seabed or other underwater deployment substrate, whereby the sub frame 30 will undergo rotational displacement relative to the main frame 28 until all four feet 24, 24′ are in contact with the seabed. At this point the curable component will set, immobilising the sub frame 30 relative to the main frame 28, in order to provide a rigid connection between the two while ensuring that all four of the feet 24, 24′ have been allowed to fully contact the seabed and thus fully support the system 10.

[0053] It should also be understood that while relative displacement between the main frame 28 and the sub frame 30 is facilitated by the provision of a pivot defined by the stub axle 34, any other suitable arrangement or design may be employed which permits displacement of one or more of the feet 24 relative to the remainder of the base 14, in particular the fixed feet 24′. For example it is envisaged that a deformable element may be provided between the main frame 28 and the sub frame 30, and could for example be formed integrally with either of both said components, which deformable element may be designed to undergo plastic or elastic deformation such as to permit the sub frame 30 to be displaced relative to the main frame 28. Similarly the stub axle 34 could be omitted such that a fixed or non articulated connection exists between the main frame 28 and the sub frame 30. In such an arrangement the cross member 32, or portions thereof, may be plastically or elastically deformable in order to permit displacement of one or both of the feet 24 relative to the remainder of the base 14.

[0054] Referring now to FIG. 2 there is illustrated a hydroelectric turbine system according to an alternative embodiment of the present invention, and generally indicated as 110. In this alternative embodiment like components have been accorded like reference numerals and unless otherwise stated perform a like function. The system 110 comprises a turbine 112 supported on a base 114 which is formed from a plurality of frame members 120, the base 114 further comprising four legs 126 at the free end of each of which is a foot 124, 124′. The base 114 comprises a main frame 128 consisting of two of the frame members 120 in a T-shaped configuration, and a sub frame 130 which comprises a cross member 132 at either end of which is provided one of the legs 126. The sub frame 130 is arranged to undergo rotational displacement relative to the main frame 128 by means of a coupling 134. Unlike the embodiment illustrated in FIG. 1 the system 110 of FIG. 2 is designed such that the sub frame 130 is displaceable about an axis which extends substantially perpendicular to an axis of rotation of the turbine 112 during operation. The system 110 nevertheless embodies the same functionality, allowing one and preferably a pair of the feet 124 to be displaced relative to the remainder of the base 114, such as to ensure that all four of the feet 124, 124′ contact the seabed and therefore bear the load of the system 110 during use.

[0055] The system 10, 110 of the present invention therefore provides a means of designing a base 14, 114 on which a turbine or other components may be support, and which base 14, 114 has four ground contacting feet 24, 24′, 124, 124′ which will automatically all contact the seabed in order to provide improved load bearing and stability, while enabling the base 14, 114 to be used in the capacity of a gravity base which does not require pre or post deployment site preparation. This provides significant improvements in stability over a tripod or three legged base (not shown), which is more susceptible to sliding displacement along the seabed due to the reduced number of legs, overturning, in particular in the presence of “off axis” effects, and the general instability of a three legged arrangement.