WO2009109701A1

WO2009109701A1 - Wave power plant

Info

Publication number: WO2009109701A1
Application number: PCT/FI2009/050172
Authority: WO
Inventors: Marco Pyy
Original assignee: Marco Pyy
Priority date: 2008-03-05
Filing date: 2009-03-02
Publication date: 2009-09-11
Also published as: EP2265814A1; EP2265814A4; FI20085210A0

Abstract

The invention relates to a wave power plant, comprising a base structure (1) for arrangement on a submerged surface (2), a lever arm (3) pivotally connected to said base structure (1) for angular oscillation about a pivotal axis (4), and energy extracting means (7) for extracting energy of said angular oscillation of said lever arm (3). A float means (8) is connected to said lever arm (3), said float means (8) being adapted to oscillate by the action of waves (22) so that said lever arm (3) connected to said float means (8) is adapted to angularly oscillate about said pivotal axis (4). Said energy extracting means (7) comprises a fluid cylinder (9) attached between said lever arm (3) and said base structure (1), a fluid motor (10) in fluid connection with said fluid cylinder (9), and a generator means (12) functionally connected to said fluid motor (10).

Description

WAVE POWER PLANT

Field of the invention

The invention relates to a wave power plant as defined in the preamble of independent claim 1.

Then invention relates to an apparatus for capturing of energy of waves for generating electrical energy.

Different apparatuses for capturing of energy of waves for generating electrical energy are known from the prior art. Publication US 5,084,630 discloses a wave powered generator system incorporating a deck supported in a cantilevered fashion from a pier structure and extending over the coastal area of a sea. The deck supports plurality of paddle and hydraulic cylinder units. Each paddle and hydraulic cylinder unit has a paddle that is pivotally mounted to swing under the force of ocean waves. Connecting arms between the paddle and its pivot incorporate hydraulic cylinders that allow the paddle to be vertically adjusted according to variations in height of the sea. In addition, the paddle has extendable wings for enlarging or reducing the effective size of the paddle in response to variations in the height and velocity of the waves. These variations are sensed by pressure and flow rate sensors that sense the pressure and flow rate of hydraulic fluid pumped by reciprocation of the paddle. Publication WO 2007/019608 discloses a wave energy capturing device comprising a base adapted for fixed connection to a submerged surface. At least one elongate buoyant paddle is pivotally mounted to the base about a first pivotal axis, for angular oscillation through an angle range when wave motion applies a force to the paddle. The paddle has a longitudinal axis, an upper end portion and a lower end portion. An energy transfer member is attached to the paddle and is adapted to be driven by the angular oscillation of the paddle. A paddle adjustment assembly is associated with the paddle and is adapted to adjust the angle range of the paddle in magnitude and/or angular position relative to the first pivotal axis.

Publication US 3,970,415 discloses a power generating plant that utilizes the motion of ocean waves to drive turbine generators in a power station that is installed on a land. The plant includes a series of underwater units each of which includes a hollow sphere that floats upon the water so that it rises and falls as waves move by, the ball being mounted on an end of a pivoting arm to which there is connected a piston slidable in a cylinder so to pump ocean water through a duct to the turbines in the power station that is installed on a land.

Publication US 4,111,610 discloses a wave powered pumping system of a type adapted for installation in a body of water subject to surface wave motion. A support structure is adapted to be mounted within the body of water, and a float is connected to a reciprocal structure which is movably connected to the support structure for permitting the float to rise and fall upon the water surface in response to wave motion. A load is driven by the reciprocal structure, and apparatus is provided which opposes free movement of the reciprocal structure toward two positional extremes for minimizing the likelihood of damage to the pumping system which would otherwise occur during severe weather conditions.

Short description of the invention

One object of the invention is to provide a new and inventive wave power plant. The wave power plant of the invention is characterized by the definitions of independent claim 1.

Preferred embodiments of the wave power plant are defined in the dependent claims. The wave power plant comprises a base structure for arrangement on a submerged surface, and a lever arm pivotally connected to the base structure for angular oscillation about a pivotal axis. A float means is connected to the lever arm. The float means is adapted to oscillate by the action of waves so that the lever arm connected to the float means is adapted to angularly oscillate about the pivotal axis when the float means oscillates by the action of waves. The wave power plant comprises furthermore energy extracting means for extracting energy of the angular oscillation of the lever arm. The energy extracting means comprises a fluid cylinder attached between the lever arm and the base structure, a fluid motor in fluid connection with the fluid cylinder, and a generator means functionally connected to the fluid motor. The fluid cylinder comprises a cylinder barrel in which a piston connected to a piston rod is movably arranged. The piston is adapted to oscillate in the cylinder barrel when the lever arm oscillates about the pivotal axis so that the fluid cylinder is adapted to pump fluid and to create a fluid flow when the piston oscillates in said cylinder barrel. The fluid motor, which is in fluid connection with the fluid cylinder, is adapted to convert said fluid flow into rotational movement. The generator means functionally connected to the fluid motor is adapted to convert said rotational movement of the fluid motor into electrical energy.

In a preferred embodiment of the invention the base structure and the lever arm and the fluid cylinder is arranged completely submerged. In this preferred embodiment of the invention the lever arm is in the form of a sinking elongate lever arm having a higher density than that of the ambient water. In this preferred embodiment of the invention the lever arm is an elongate lever arm having a longitudinal axis, a first end portion and a second end portion. In this preferred embodiment of the invention the first end portion of the lever arm is connected to the base structure. In this preferred embodiment of the invention the float means is connected to the lever arm by means of a connection member arranged between the float member and the lever arm so that the lever arm can be arranged completely submerged and the float member be arranged floating at least partly on the waters surface. The connection member is connected to the lever arm at the second end portion. Because the lever arm is in the form of a sinking elongate lever arm having a higher density than that of the ambient water, the lever arm will sink i.e. create a rotational movement of the lever arm in a first direction around the pivotal axis of the lever arm. The float means connected to the lever arm by means of the connection member will, on the other hand, create a rotational movement of the lever arm in a second direction, which is opposite to the first direction, around the pivotal axis of the lever arm. In this way the lever am will together with the float means create an oscillate movement of the piston in the cylinder barrel of the fluid cylinder.

In a preferred embodiment of the invention the lever arm is pi vo tally connected to the base structure at a pivotal axis situated between a first end of the lever arm and a second end of the lever arm so that a first lever arm portion is formed between the first end of the lever arm and the pivotal axis and so that a second lever arm portion is formed between the second end of the lever arm and the pivotal axis. The length of the first lever arm portion is preferably, but not necessarily, between about 2 to about 10 times the length of the second lever arm portion, for example about 3, about 4, about 5, about 6, about 7, about 8, or about 9 times the length of the second lever arm portion. In this preferred embodiment of the invention the float means is connected to the lever arm near the second end of the lever arm and the lever arm is connected to the fluid cylinder near the first end of the lever arm. Because the length of the first lever arm portion is several times the length of the second lever arm portion, the force applied by the floating means and the weight of the first lever arm portion of the lever arm on the fluid cylinder will be greater than if the lengths would be equal based on the physical principle of leverage. In a preferred embodiment of the invention the fluid cylinder is a hydraulic cylinder, preferably configured to use water as the hydraulic fluid. In this preferred embodiment of the invention the fluid motor, which is in fluid connection with the fluid cylinder, and which is adapted to convert said fluid flow into rotational movement, is a hydraulic motor preferably configured to use water as the hydraulic fluid. In a preferred embodiment of the invention the wave power plant comprises an electrolysis apparatus for producing hydrogen. The electrolysis apparatus is functionally connected with said generator means for feeding electrical energy from said generator means to said electrolysis apparatus.

List of figures

In the following the invention will described in more detail by referring to the figures, of which

Figure 1 shows a first embodiment of the invention, Figure 2 shows a second embodiment of the invention, and

Figure 2 shows a third embodiment of the invention. Detailed description of the invention

The figures show a wave power plant, comprising a base structure 1 for arrangement on a submerged surface 2. Said base structure 1 may be supported on said submerged surface 2 in an unattached (freely standing) fashion or attached to said submerged surface.

The wave power plant comprises a lever arm 3, which is pivotally connected to said base structure 1 for angular oscillation about a pivotal axis 4. Said pivotal axis 4 is preferably, but not necessarily, essentially horizontal. The lever arm 3 is preferably, but not necessarily, an elongate lever arm 3 having a longitudinal axis (not marked with a reference numeral), a first end 5 and a second end 6.

The wave power plant comprises energy extracting means 7 for extracting energy of said angular oscillation of said elongate lever arm 3.

The wave power plant comprises a float means 8 connected to said lever arm 3. Said float means 8 is adapted to oscillate by the action of waves 22 so that said lever arm 3 connected to said float means 8 is adapted to angularly oscillate about said pivotal axis 4 when said float means 8 oscillates by the action of waves 22.

Said energy extracting means 7 comprises a fluid cylinder 9 attached between said lever arm 3 and said base structure 1, a fluid motor 10 in fluid connection via fluid conduit means 11 with said fluid cylinder 9, and a generator means 12 functionally connected to said fluid motor 10.

In the figures, the lever arm 3 is pivotally connected to the base structure 1 at a pivotal axis 4 situated between the first end 5 of the lever arm 3 and the second end 6 of the lever arm 3 so that a first lever arm portion 20 is formed between the first end 5 of the lever arm 3 and the pivotal axis 4 and so that a second lever arm portion 21 is formed between the second end 6 of the lever arm 3 and the pivotal axis 4. The length of the first lever arm portion 20 is preferably, but not necessarily, between about 2 to about 10 times the length of the second lever arm portion 21, for example about 3, about 4, about 5, about 6, about 7, about 8, or about 9 times the length of the second lever arm portion 21. In the figures, the float means 8 is connected to the lever arm 3 near the second end 6 of the lever arm 3 and the lever arm 3 is connected to the fluid cylinder 9 near the first end 5 of the lever arm 3. In the figures, the length of the first lever arm portion 20 is about 5 times the length of the second lever arm portion 21. Because the length of the first lever arm portion 20 is about 5 times the length of the second lever arm portion 21, the force applied by the floating means and the weight of the lever arm on the fluid cylinder 9 will be greater than if the length of the first lever arm portion 20 and the length of the second lever arm portion 21 would be equal based on the physical principle of leverage.

Said energy extracting means 7 may comprise a gearing (not shown in the figures) between the fluid motor 10 and the generator means 12 for rotating the generator means 12 faster than the fluid motor 10.

Said fluid cylinder 9 comprises a cylinder barrel 13, in which a piston 14 connected to a piston rod 15 is movably arranged. Said piston 14 of said fluid cylinder 9 is adapted to oscillate in said cylinder barrel of said fluid cylinder 9 when said lever arm 3 oscillates about said pivotal axis 4 so that said fluid cylinder 9 is adapted to pump fluid and to create a fluid flow when said piston 14 oscillates in said cylinder barrel and said fluid cylinder 9.

Said fluid motor 10 is adapted to convert said fluid flow into rotational movement as said fluid flow flows through said fluid motor 10. It is clear for a person skilled in the fluid power art that the fluid system comprising the fluid cylinder 9, the fluid connection means 11 and the fluid motor 10 shown in figures is simplified and that the figures only shows only the basic principle of the invention.

Said generator means 12 is adapted to convert said rotational movement of said fluid motor 10 into electrical energy. Said lever arm 3 is preferably, but not necessarily, at least partly arranged in the water.

In figure 1 and 2 is said elongate lever arm 3 completely arranged in the water. Said lever arm 3 is preferably, but not necessarily, in the form of a sinking elongate lever arm 3 having a higher density than that of the ambient water. Alternatively or in addition a weight can be attached to said lever arm 3 for rotating said lever arm 3 about said pivotal axis 4 in rotational direction opposite to that created by the float means.

In the preferred embodiments shown in the figures the base structure 1 and the lever arm 3 and the fluid cylinder 9 is arranged completely submerged.

The wave power plant comprises, preferably, but not necessarily, a hydraulic system in which the hydraulic fluid is water. Said float means 8 is preferably, but not necessarily, connected to said lever arm 3 by means of a connection member 18 arranged between said float means 8 and said elongate lever arm 3 as shown in the figures. Said flexible connection member 18 is preferably, but not necessarily, at least partly flexible but not preferably elastic. Alternatively may said float means 8 be directly connected to said lever arm 3 or said float means 8 be integrally formed in said lever arm 3.

Said fluid motor 10 is preferably, but not necessarily, arranged in said base structure 1 as shown in the figures. Alternatively said fluid motor 10 may be arranged in a separate base structure 1.

Said fluid motor 10 is preferably, but not necessarily, arranged in a submerged position as shown in the figures. Alternatively said fluid motor 10 may be arranged in said base structure 1 above the water level. Alternatively said fluid motor 10 may be arranged in a floating structure separate from said base structure 1. Alternatively said fluid motor 10 may be arranged in a structure arranged on a submerged surface 2 partly in a submerged position and partly above the water level, which is separate from said base structure 1. At least if said fluid motor 10 is arranged in a submerged position, said fluid motor 10 is preferably, but not necessarily, completely sealed from the ambient water.

Said generator means 12 is preferably, but not necessarily, arranged in said base structure 1 as shown in the figures. Alternatively said generator means 12 may be arranged in a separate base structure 1.

Said generator means 12 is preferably, but not necessarily, arranged in a submerged position. Alternatively said generator means 12 may be arranged in said base structure 1 above the water level. Alternatively said generator means 12 may be arranged in a floating structure separate from said base structure 1. Alternatively said generator means 12 may be arranged in a structure arranged on a submerged surface 2 partly in a submerged position and partly above the water level, which is separate from said base structure 1. At least if said generator means 12 is arranged in a submerged position, said fluid motor 10 is preferably, but not necessarily, completely sealed from the ambient water. The wave power plant shown in figure 3 comprises a spring means 23 or corresponding resilient means such as a pneumatic cylinder or a gas cylinder arranged between the lever arm 3 and the base structure 1 for pulling the lever arm 3 towards the submerged surface 2 as said lever arm 3 oscillates about said pivotal axis 4.

The energy extracting means 7 of the wave power plant shown in figure 2 comprises an electrolysis apparatus 16 for producing hydrogen. The electrolysis apparatus 16 is functionally connected with said generator means 12 for feeding electrical energy from said generator means 12 to said electrolysis apparatus 16 for the operation of said electrolysis apparatus 16.

Said electrolysis apparatus 16 is preferably, but not necessarily, arranged in said base structure 1 as shown in the figures. Alternatively said electrolysis apparatus 16 may be arranged in a separate base structure 1.

Said electrolysis apparatus 16 is preferably, but not necessarily, arranged in a submerged position. Alternatively said electrolysis apparatus 16 may be arranged in said base structure 1 above the water level. Alternatively said electrolysis apparatus 16 may be arranged in a floating structure separate from said base structure 1. Alternatively said electrolysis apparatus 16 may be arranged in a structure arranged on a submerged surface 2 partly in a submerged position and partly above the water level, which is separate from said base structure 1. At least if said electrolysis apparatus 16 is arranged in a submerged position, said fluid motor 10 is preferably, but not necessarily, completely sealed from the ambient water.

If the wave power plant comprises an electrolysis apparatus 16 for producing hydrogen, said wave power plant comprises preferably, but not necessarily, a hydrogen tank 17 in fluid connection with said electrolysis apparatus 16 for receiving and storing hydrogen produced by said electrolysis apparatus 16.

If the wave power plant comprises a hydrogen tank 17, said wave power plant comprises preferably, but not necessarily, a hydrogen tank 17 in the form of a releasable attached hydrogen tank 17, and connection means 19 for releasable connecting said hydrogen tank 17 with said electrolysis apparatus 16. Such arrangement allows to detach hydrogen tank 17 from the wave power plant and to use the use the hydrogen tank 17 for transporting hydrogen to the site where the hydrogen is used or distributed for use.

If the wave power plant comprises an electrolysis apparatus 16 for producing hydrogen, said wave power plant comprises alternatively a pipeline for feeding hydrogen from the wave power plant.

The wave power plant may comprise a wind mill (not shown in the figures) attached to the base structure for producing wind energy.

If the wave power plant comprises a wind mill attached to the base structure for producing wind energy and an electrolysis apparatus 16 for producing hydrogen, said wind mill is preferably, but not necessarily, functionally connected to said wind mill for feeding electrical energy from said wing mill to said electrolysis apparatus 16 for the operation of said electrolysis apparatus 16.

It is apparent to a person skilled in the art that as technology advanced, the basic idea of the invention can be implemented in various ways. The invention and its embodiments are therefore not restricted to the above examples, but they may vary within the scope of the claims.

Claims

1. Wave power plant, comprising a base structure (1) for arrangement on a submerged surface (2), a lever arm (3) being pivotally connected to said base structure (1) for angular oscillation about a pivotal axis (4), and energy extracting means (7) for extracting energy of said angular oscillation of said lever arm (3), characterized in that a float means (8) is connected to said lever arm (3), said float means (8) being adapted to oscillate by the action of waves (22) so that said lever arm (3) connected to said float means (8) is adapted to angularly oscillate about said pivotal axis (4) when said float means (8) oscillates by the action of waves (22), in that said energy extracting means (7) comprises a fluid cylinder (9) attached between said lever arm (3) and said base structure (1), a fluid motor (10) in fluid connection with said fluid cylinder (9), and a generator means (12) functionally connected to said fluid motor (10), in that said fluid cylinder (9) comprises a cylinder barrel (13) in which a piston (14) connected to a piston rod (15) is movably arranged, in that said piston (14) of said fluid cylinder (9) is adapted to oscillate in said cylinder barrel (13) of said fluid cylinder (9) when said lever arm (3) oscillates about said pivotal axis (4) so that said fluid cylinder (9) is adapted to pump fluid and to create a fluid flow when said piston () oscillates in said cylinder barrel (13) of said fluid cylinder (9), in that said fluid motor (10) is adapted to convert said fluid flow into rotational movement, and in that said generator means (12) is adapted to convert said rotational movement of said fluid motor (10) into electrical energy.

2. The wave power plant according to claim 1 , characterized in that said lever arm (3) is at least partly arranged submerged, and in that said lever arm (3) is in the form of a sinking lever arm (3) having a higher density than that of the ambient water.

3. The wave power plant according to claim 1 or 2, characterized in that said fluid is water.

4. The wave power plant according to any of the claims 1 to 3, characterized in that said float means (8) is connected to said lever arm (3) by means of a connection member (18) arranged between said float means (8) and said lever arm (3).

5. The wave power plant according to claim 4, characterized in that said flexible connection member (18) is at least partly flexible.

6. The wave power plant according to any of the claims 1 to 5, characterized in that said fluid motor (10) is arranged in said base structure (1).

7. The wave power plant according to any of the claims 1 to 6, characterized in that said fluid motor (10) is arranged in a submerged position.

8. The wave power plant according to claim 7, characterized in that said fluid motor (10) is completely sealed from the ambient water.

9. The wave power plant according to any of the claims 1 to 8, characterized in that said generator means (12) is arranged in said base structure (1)

10. The wave power plant according to any of the claims 1 to 9, characterized in that said generator means (12) is arranged in a submerged position

11. The wave power plant according to claim 10, characterized in that said generator means (12) is completely sealed from the ambient water.

12. The wave power plant according to any of the claims 1 to 11, characterized in that said energy extracting means (7) comprises a electrolysis apparatus (16) for producing hydrogen, and in that said electrolysis apparatus (16) is functionally connected with said generator means (12) for feeding electrical energy from said generator means (12) to said electrolysis apparatus (16).

13. The wave power plant according to claims 12, characterized in that said electrolysis apparatus (16) is arranged in said base structure (1).

14. The wave power plant according to claim 12 or 13, characterized in that said electrolysis apparatus (16) is arranged in a submerged position.

15. The wave power plant according to claim 14, characterized in that said electrolysis apparatus (16) is completely sealed from the ambient water.

16. The wave power plant according to any of the claims 12 to 15, characterized by a hydrogen tank (17) in fluid connection with said electrolysis apparatus (16) for receiving and storing hydrogen produced by said electrolysis apparatus (16).

17. The wave power plant according to claim 16, characterized by connection means for releasable connection said hydrogen tank (17) with said electrolysis apparatus (16).

18. The wave power plant according to any of the claims 1 to 17, characterized in that said base structure (1) is supported on said submerged surface (2).

19. The wave power plant according to any of the claims 1 to 18, characterized in that said base structure (1) is attached to said submerged surface (2).

20. The wave power plant according to any of the claims 1 to 19, characterized in that the lever arm (3) in an elongate lever arm 3 having a first end (5) and a second end (6),in that the lever arm (3) is pivotally connected to the base structure (1) at a pivotal axis

(4) situated between the first end (5) of the lever arm (3) and the second end (6) of the lever arm (3) so that a first lever arm portion (20) is formed between the first end (5) of the lever arm (3) and the pivotal axis (4) and so that a second lever arm portion (21) is formed between the second end (6) of the lever arm 3 and the pivotal axis (4), in that the float means (8) is connected to said first lever arm portion (20) of the lever arm

(3), and in that the fluid cylinder (9) attached to said second lever arm portion (21) of the lever arm (3).

21. The wave power plant according to claim 20, characterized in that the length of the first lever arm portion (20) between about 2 to about 10 times the length of the second lever arm portion (21), for example between about 3 to 9, between about 4 to 8 about 4, between about 5 to 7, or about 6 times the length of the second lever arm portion (21).

22. The wave power plant according to any of the claims 1 to 21, characterized by a spring means (23) or corresponding resilient means arranged between the lever arm (3) and the base structure (1) for pulling the lever arm (3) towards the submerged surface (2) as said lever arm (3) oscillates about said pivotal axis (4).