WO2010080045A1

WO2010080045A1 - Device for generating energy from the motion of sea waves

Info

Publication number: WO2010080045A1
Application number: PCT/PT2009/000002
Authority: WO
Inventors: Nuno Armando Da Fonseca Teixeira
Original assignee: Sea For Life, Lda.
Priority date: 2009-01-08
Filing date: 2009-01-08
Publication date: 2010-07-15

Abstract

This invention relates to a device intended to harness the energy from the motion of sea waves for the generation of electric power. Said device is comprised of two identical floating bodies with a cylindrical shape (1), which will be exposed to the movement of waves. The two floating bodies are connected by means of arms (2) to a rotary axis (rotary in a plan perpendicular to the sea) (3), this being located on a rotating head (rotating m a plan parallel to the sea) (5), above the (usually predictable) reach of water, and around a mast (6) which is fixed to the sea bed. By action of sea waves, the floating cylinders, which have the buoyancy inherent to their volume and mass, will rise towards the crests and fall towards the troughs. So, an upward and downward circular movement is performed around the axis, where it will be harnessed by a hydraulic or other system (4). All the points which are susceptible of a dynamic seal will operate out of water. As a component of the system, the rotational movement of the rotating head (5) enables the floating cylinders (1) to be positioned according to the changing direction of waves propagation. The floating bodies (1) will be the selected structural element for application of the system designed to extract energy from the movement of structures without interference (7), as per the Portuguese patent PT103911. A part of the remaining structure will be used as ballast reservoirs {9} to control the movement of the floating cylinders.

Description

DESCRIPTION

"DEVICE FOR GENERATING ENERGY FROM THE MOTION OF SEA WAVES"

Scope of the invention

This invention relates to a device intended to harness energy from the movement of waves.

Prior art

Currently, as a result of the oil crisis and environmental concerns to which societies are increasingly committed, there is a growing demand for the use of renewable sources of energy, namely the energy from the sea, and in particular the energy generated by the sea waves. Many documents on the harnessing- of energy from the waves can be found in the literature. However, as far as the applicant knows, disclosure has not been made as to devices whose points susceptible of a dynamic seal are designed to operate out of water, thus positively contributing to the system's reliability and durability.

Summary of the invention

The distinguishing feature of this invention, when compared to devices and systems of the prior art, is che fact that all the points susceptible of havάng a dynamic seal operate out of water. This means chat all the parts comprising the system for the harnessing of energy are above the water surface. Said feature is critical to the system's reliability and durability.

Brief description of the drawings

The following description is based on the enclosed drawings which,, without a limiting character, iliusrrate the preferred embodiments of this invention:

- Figure 1 is a raised side view of the system in the zero position, considering the mean sea level.

- Figure 2 is a raised side view, wherein che floating bodies are in the rising position due to the passage of the wave's crest.

-- Figure 3 is a raised side view, wherein the floating bodies are in the lowest falling posit.ion, due to the passage of the wave's trough.,

Figure 4 is an isometric view of the whole system, showing in particular the positioning of the floating bodies (1) and the rotating head (5) .

- Figure 5 is a raised side view of the anchorage to the sea bed by means of a high buoyancy platform, which is In half-deep water and is fixed by strain cables to the sea bed, this being a solution which is also possible in deep water.

- Figure 6 is a raised side view of a potential implementation of the hybrid system, the above-mentioned Fystem for harnessing the energy from the movement of waves and wind,

- Figure 7 is a raised side view of the potential installation of a higher number of floating bodies on the same mast .

Detailed description of the invention

As shown in the preferred embodiment of the invention in Figures 1 to 6, the device comprises a set of two floating bodies with a cylindrical shape {1} , which will be exposed to the movement of waves. The configuration of said floating bodies (1) may be the most suitable and be different from the cylindrical shape.

The two floating bodies are connected by means of arms (2) to a rotary axis (rotary in a plan perpendicular to the sea) (3) , this being located on a rotating head (rotating in a plan parallel to the sea) (-5) , above the (usually predictable) reach of water, and around a mast (6) which is fixed to the sea bed. By action of sea waves, the floating bodies (1) , which have the buoyancy inherent to their volume and mass, will rise towards the crests and fall towards the troughs. So, an upward and downward circular movement is performed around the axis (3) , this movement being harnessed by an energy extracting system (4) .

Said energy extracting system (4) may be a hydraulic or any other extracting system as appropriate. The device also comprises a set of hydraulic and/or other elements which are required for the operation of the electric generator. This energy extracting system (4) further includes a set of elements required fjor- the operation of electric generators (not shown) .

The energy harnessing system (4) is also susceptible of being used with a hydraulic or other intermediate converter system. Furthermore, the direct conversion of energy can be made, i.e. by electric generators which are adapted to the movement, using for instance linear or reciprocating electric generators.

As an example, in case the. harnessing is done by a hydraulic system, the energy conversion can take place by the closed-circuit pumping of oil into a high-pressure reservoir, which outputs a constant given pressure and flow rate in a hydraulic motor, within a certain range of intermediate values which are defined according to the sea state. Said motor will drive the electric generator. One of the most important characteristics of this system is that all the points susceptible of being dynamically sealed, i.e., all the components (2), (>3) , (5) and the extracting system (4) , will operate out of water, thus contributing significantly to the system's reliability and durability.

The rotational movement capacity of the rotating head (5) will enable the floating bodies (1) to be positioned according to the changing direction of, waves propagation. This circular movement occurs favourably to the wave propagation, profiting also from its displacement velocity. In other words, the floating body Will be driven by the action ©f a force which is the one resulting from εhe buoyancy of the floating body, as well as from the wave's displacement velocity. Therefore, the expected motion in the floating elements of this device is "favourable" as to benefit from the variable "wave's displacement velocity" .

The floating bodies (1) , in addition to enabling the harnessing of energy in the rotating head (5) , are equipped with an energy extracting system (7) which is mounted, insi.de them, according to the patent application PCT PT 2008 000056, dated 23^rd December 2008, filed by the same applicant. Therefore, it is possible to add to the energy obtained from the rotating head (5) and its related components, the energy being eventually generated inside the floating bodies. This fact will contribute to an increase m performance of power generation.

A part of the remaining structure of the floating bodies (1) will be used as ballast reservoirs (9) for control lxnq the movement of the floating bodies (1) .

The floating bodies system (1) will be functioning downstream of the mast (6) , depending on the waves direction. To this end, there will be an alignment towards the direction of waves propagation, along with sizing combinations, which translates into a rotation of the whole system around the mast (6) and contributes to Detter performances in production and control.

As can be observed m the Figures, the mast (6) can be anchored to the sea bed if this is at a low depth. For higher depths, the mast (6) can be fixed to a high- buoyancy floating platform in half-deep water (8) , said platform being anchored to the sea bed by strain cables.

The energy harnessing device, which is the object of this invention, can comprise more than one pair of floating bodies (1) as shown in the embodiment of Figure 7. In this case, the other floating bodies (1) are mounted at a distance which is estimated according to the principles of wave's reformation, as well as to the space required to their mechanical operation. The configuration of other floating bodies {1} can be the same of, or different from, the one of the pair of floating bodies in the above described embodiment. On the other hand', the arms (2) can be connected to the axis (3) or to the arm (2) of the first pair which is closer to the mast (6) .

The previously described devices can be implemented at any onshore , nearshore, offshore or other site, depending on the conditions and the desired energy use .

In either of the embodiments herein described and their respective fixing means of the mast (6), the generated power is always transmitted by a static cable

(10) along the whole way, thus influencing significantly its durability and costs.

The operation of the device, this meaning the floating bodies as well as all the components of the energy harnessing system, is made by automatic control and/or remote control, so that the device is adjusted to the sea state and the pre-set parameters of regular energy supply are met, in order to optimize the energy production and protect its structural integrity.

As can be observed in Figure 6, this device also allows a wind turbine (11) to be applied to the mast (6) , thus resulting in a hybrid model.

Claims

1. A device intended for the generation of energy from the movement of waves, characterized in that it comprises a set of, at least, two identical floating bodies (1), which will be exposed to the movement of waves and operate perpendicularly to the direction of sea waves, said bodies being connected by means of arms (2) to a rotary axis (3) in a plan perpendicular to the sea, which is located on a rotating head (5) in a plan parallel to the sea, above the usually predictable reach of water, and which is combined with an energy extracting system (4) .

2. A device according to claim 1, characterized in that the floating bodies have a substantially cylindrical configuration.

3. A device according to the preceding claims, characterized in that the rotary points and the rotating head, as well as all the sections which are susceptible of being dynamically sealed, operate out of water.

4. A device according to claάm 1, characterized 1n that, with a view to ease the alignment towards the direction of waves propagation, the rotating head (5) rotates around the mast (6) where it. is installed, said mast being fixed, depending on the water depth, to the sea bed or to a high-buoyancy floating platform in half-deep - 2

water (8) , said platform being anchored to the sea bed by strain cables.

5. A device according to claims 1 and 2 , characterized in that the floating bodies (l) , which have the buoyancy inherent to their volume and mass, will rise towards the crests and fall towards the troughs, so that an upward and downward circular movement is performed around the axis (3) , said movement being harnessed by an energy extracting system (4) and occurring favourably to the wave propagation, profiting also from its displacement velocity.

6. A device according to claims 1, 2 and 5, characterized in that the energy extracting system is a hydraulic intermediate converter.

7. A device according to claims 1, 2, 5 and 6, characterized in that the rotation caused around the axis (3) is directly harnessed using electric generators adapted to the movement.

8. A device according to claims 1 and 2, characterized in that the rotational movement of the rotating head (5) enables the floating cylinders (1) to be positioned downstream of the mast (6) , according to the changing direction of waves propagation.

9. A device according to claims 1, 2 and 4, characterized in that the float-ing bodies (1) comprise 3 -

inside them another energy extracting system, said energy being added to the one obtained by the system (4) .

10. A device according to the preceding claim, characterized m that a part of the floating bodies structure (1) is used for the installation of ballast reservoirs (9) , which allow to control the floating bodies ( Ii) movement .

11. A device according to claims 1, 4 and 5, characterized m that the hydraulic system (4) further comprises a set of components which are required for the operation of the electric generators.

12. A device according to the preceding claim, characterized in that the energy is constantly transmitted within a certain range of intermediate values, which are established according to the sea state.

13. A device according to the preceding claims, characterized in that it can be installed at any onshore, nearshore, offshore or other site.

14. A device for harnessing energy according to the preceding claims, characterized in that the electrical power transmission cable (10) is a static cable along the whole way, thus influencing significantly its durability and costs. - 4 -

15. A device according to the preceding claims, characterized in that it is operated by automatic control and/or remote control, so that the device is adjusted to the sea state and the pre-set parameters of regular energy supply are met, in order to optimize the energy production and protect its structural integrity.

16. A device for harnessing energy according to the preceding claims, characterized in that it can be applied to a mast, which can then be used to install a wind turbine (11), resulting in a hybrid model.

17. A device for harnessing energy according to the preceding claims, characterized in that other floating bodies (1) , having the same or a different configuration, are mounted at a distance which is estimated in view of the principles of wave's reformation, as well as of the space required to their mechanical operation.

18. A device for harnessing energy according to the preceding claims, characterized in that the length of the arm (2) depends on the positioning in height of its rotary axis (3) and on the sea state statistics at the implementation site.