BE1024212B1 - FLOATING EOLIENNE - Google Patents

Abstract

The present invention relates to a floating wind turbine (1) comprising: (a) blades attached to a mast extending along an axis, Z, such that exposure of the blades to the wind causes rotation of the mast around the wind Z axis, (b) a channel forming a coil extending along the longitudinal axis, Z, and comprising an upstream opening and a downstream opening, the channel being fixed rigidly to the mast so that when the mast turns around the axis, Z, the coil rotates in phase about the longitudinal axis, (c) a fixed bearing adjacent to the downstream opening allowing rotation of the coil about the longitudinal axis, Z, (d) a anchoring to anchor the bearing in the bottom of a body of water, (e) ballast attached to an outer surface of the channel.

Description

FLOATING EOLIENNE

FIELD OF THE INVENTION

The present invention relates to a particular floating wind turbine, for storing the wind energy captured by the blades of the wind turbine in the form of a pocket of compressed air stored deep below the surface of a plane. of water on which the wind turbine rests. The energy thus stored can be restored when the demand requires releasing the captured air to the surface thus activating an alternator. The floating wind turbine of the present invention comprises very few moving parts and requires very little maintenance once installed offshore.

BACKGROUND

[0002] For ecological reasons made spectacularly obvious by the phenomena related to global warming, it becomes essential to significantly reduce the emissions of CO2 and other greenhouse gases. Such an objective is made particularly difficult by a growing energy demand due to demographic growth and the emergence of new industrial powers. The list of renewable energies that do not lead to pollutant emissions is limited to transforming energies of the earth (geothermal energy), air (wind energy), water (hydropower) and the sun (solar energy). Indeed, biofuels have the advantage of being renewable but their combustion emits CO2. Nuclear energy does not emit CO2, but it is not renewable and creates radioactive waste for thousands of years to come.

Wind energy is interesting because it emits no pollutant. However, it is difficult to control, since the winds turn and their intensity varies without being able to do anything about it. A first difficulty lies in the fact that a wind turbine can be designed to operate with low-speed or high-speed winds, but they are rarely operational across the entire spectrum of wind speeds encountered in a wind turbine zone. exploitation, thus considerably reducing their yield when they must be neutralized by lack or excess of wind.

A second difficulty is that wind turbines are very expensive and include many moving parts that wear and need to be replaced regularly. Such an operation is made even more difficult in off-shore offshore wind farms, where the wind is blowing violently. All handling of off-shore wind turbines requires significant means of boats or helicopters.

A third difficulty is related to variations in the intensity of the wind, which does not necessarily ensure the supply of electricity at a time when demand is high, because the wind does not necessarily blow at this time. there and, on the other hand, the wind can blow hard at times of low demand. The exploitation of wind energy can only be optimized if energy storage means are developed.

In patent BE2010 / 0466, an electrical energy storage means is proposed in which an inflated air balloon is led to the bottom of a body of water by winding a cable comprising a return in the bottom of the water. This operation consumes energy and is performed when energy is available or cheap and that demand and low. When the energy demand increases, the balloon is released and by going up to the surface the cable while unwinding activates a current generator. The source of the energy used to lower the balloon is not limited and such a system could be coupled to an off-shore wind turbine. However, the problem of wear of many moving parts exposed to a particularly hostile marine environment remains sensitive.

There remains a need for the exploitation of wind energy that addresses the three major problems mentioned above, that can operate over a wide range of wind speeds, includes few moving parts requiring little handling. and finally, to store wind energy when it is available and to return it as electrical energy when it is desired. The present invention provides a solution to overcome these problems in an innovative and simple way.

SUMMARY OF THE INVENTION

The invention is as defined in the main claim and preferred embodiments are defined in the dependent claims. The present invention relates to a floating wind turbine comprising: (a) one or more blades rigidly attached to a mast extending along a longitudinal axis, Z, such that the exposure of the blade (s) to the wind causes rotation of the rotor; mast around the longitudinal axis, Z, (b) a channel forming a coil extending along the longitudinal axis, Z, and comprising an upstream opening and a downstream opening, the channel being fixed rigidly to the mast so when the mast rotates at a speed, v1, about the longitudinal axis, Z, the coil also rotates about the longitudinal axis at the same speed v1, (c) a bearing (5) attached adjacent to the opening swallow allowing rotation of the coil about the longitudinal axis, Z, (d) anchoring (6) to anchor the bearing in the bottom of a body of water, and (e) ballast (7) attached to a external surface of the channel, such as when the wind turbine is placed on a body of water with the landing anchored At the bottom of the water body, the mast, one or more blades and the upstream opening of the canal are out of the water and the downstream opening and the landing are submerged.

The device according to the present invention relates to a floating wind turbine comprising: (a) one or more blades fixed rigidly to a mast extending along a longitudinal axis, Z, such as the exposure of the blade or blades to the wind causes rotation of the mast about the longitudinal axis, Z, (b) a channel forming a coil extending along the longitudinal axis, Z, and comprising an upstream opening and a downstream opening, the channel being rigidly attached to the mast so that when the mast rotates at a speed, v1, about the longitudinal axis, Z, the coil also rotates about the longitudinal axis at the same speed v1, (c) a fixed bearing adjacent to the downstream aperture permitting rotation of the coil about the longitudinal axis, Z, (d) anchoring to anchor the bearing in the bottom of a water body, (e) ballast attached to an outer surface of the channel , such as when the wind turbine is placed on a body of water with the pali anchored in the bottom of the water body, the longitudinal axis, Z, forms an angle, Θ, with a horizontal axis, X1, and the mast, one or more blades and the upstream opening of the channel are out of the water and the downstream opening and the bearing are immersed [0010] In a preferred variant, the channel forms a coil formed of successive turns whose diameter decreases away from the upstream opening to the downstream opening • either linearly, forming a conical spiral, • or substantially elliptical.

It is preferred that the section of the channel decreases from the upstream opening to the downstream opening to compensate for the increase in the external pressure with the depth of immersion of the channel.

The wind turbine according to the present invention is preferably selected from wind turbines provided with a tri-type rotor type Darrieus, H, or helical type The present invention also relates to a generation system and storage of energy, comprising: • a floating wind turbine as defined supra anchored in the bottom of a body of water by anchoring and • a storage tank (8) fixed in the bottom of the body of water and allowing storing air transported from the upstream opening to the downstream opening of the channel by the rotation of the coil.

The storage tank may comprise a tarpaulin attached to the bottom of the water body thus defining a storage volume between the tarpaulin and the bottom of the body of water, the tarpaulin comprising an orifice for receiving the opening downstream of the channel in the storage volume. The storage tank may further comprise peripheral balloons connected together and with the tarpaulin by a system of distribution pipes.

The floating wind turbine can typically comprise two, three or four blades distributed around the mast. The longitudinal axis, Z, preferably forms an angle, Θ, with a horizontal axis, X1, less than 85 °, preferably less than 75 °, more preferably, less than 60 ° and the angle, Θ, is greater than 20 °, preferably greater than 30 °, more preferably greater than 40 °. The anchor allows the longitudinal axis, Z, to rotate about a vertical axis, X2, describing a precession to orient itself "back" to the wind as the direction of the wind changes.

In a preferred embodiment, the system according to the present invention further comprises an energy recovery device for guiding air stored in the storage tank to the surface of the body of water, resulting in its passage. the rotation of a generator of electric current. In particular, such a system may comprise: an outlet channel forming a coil extending along an axis of rotation, Z1, and comprising an air inlet opening and an outlet opening; air, the outlet channel being fixed to the bottom of the water body by a bearing allowing the coil to rotate about its axis of rotation, Z1, with the inlet opening in the storage tank and the opening of outlet being located outside the storage tank, preferably at the surface or out of the water body, and further comprising: air transfer means stored in the storage volume to the inlet opening of the channel the output means, preferably the transfer means, comprises an Archimedean screw or a rotating serpentine channel, or a distribution pipe, and an electric current generator activated by the rotation of the coil of the outlet channel.

Alternatively, the energy recovery device may comprise an evacuation tube comprising a first opening located in a vertically high point of the storage volume and a second opening coupled to an electric power generator positioned near or on the surface of the body of water and activated by the passage of air in the evacuation tube. A valve located on the discharge tube between the first and second openings controls the flow of air flowing into the discharge tube.

BRIEF DESCRIPTION OF THE FIGURES

These and other aspects of the invention will be clarified in the detailed description of particular embodiments of the invention, reference being made to the drawings of the figures, in which:

Fig.1 shows two views of a wind turbine variant according to the present invention.

Fig.2 shows an alternative variant of wind turbine according to the present invention.

FIG. 3 schematically illustrates (a) the path traveled by the air along the coil from the surface towards the bottom of the body of water and (b) the positioning of the ballasts inside the coil cavity.

Fig. 4 illustrates different geometries of wind turbine blades suitable for the present invention.

Fig.5 shows two variants of systems according to the present invention comprising one or two wind turbines, a storage tank and two alternative mechanisms for energy recovery by releasing the air stored in the storage tank.

Fig.6 shows different dimensions (a) of a floating wind turbine and (b) a field of floating wind turbines.

Fig.7 illustrates a variant of the invention comprising a storage tank comprising a tarpaulin and peripheral balloons. DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS Floating Wind Turbine [0019] As shown in FIGS. 1 and 2, a floating wind turbine according to the present invention comprises one or more blades (2) fixed rigidly to a mast (3) extending along a longitudinal axis, Z, such that exposure of the blade or blades to the wind causes rotation of the mast about the longitudinal axis, Z. In use, the longitudinal axis, Z, is inclined, forming an angle, Θ, with a horizontal axis, X1. The angle, Θ, is determined during the design of the wind turbine and will be maintained throughout its use. The angle, Θ, can vary between 20 and 85 °, and is preferably around 45 ° + 20 °. In order to capture the wind energy by rotating a mast inclined at an angle, Θ, with the horizontal, blades of different geometries can be used. Figure 4 illustrates some examples of suitable blade geometries for the wind turbine of the present invention. Figure 4 (a) shows a mast with three blades uniformly distributed around the longitudinal axis Z. However, unlike the vertical matte three-blade wind turbines commonly used in our landscapes, the three blades do not line up on a plane parallel to the mast, but align on a cone centered on the longitudinal axis, Z, of the mast. Preferably, the opening of the cone thus defined is such that the light closest to a horizontal plane passing through the base of the mast is also substantially horizontal, + 20 °, preferably + 10 °. As the mast forms an angle, Θ, with the horizontal axis, X1, the opening of the cone defined by the blades is therefore Θ + 20 °, preferably Θ + 10 °. Such a deployment of the blades is necessary, because the objective is to cause rotation of the mast which is inclined by an angle, Θ, whereas in the traditional tri-blade winders, the blades turn around a substantially normal axis at the mast.

[0020] A helical wind turbine is shown in Figure 4 (b) and a Darrieus Hillustrée wind turbine in Figure 4 (c). Since the helical wind turbines and Darrieus are originally designed to rotate the mast to which the blades are attached, they can be used as such in the present invention. Simply, they are designed to be mounted on a vertical mast, whereas in the present invention, the mast is inclined at an angle, Θ.

The floating wind turbine of the present invention further comprises a channel forming a coil (4) extending along the longitudinal axis, Z, and comprising an upstream opening (4u) and a downstream opening (4d) . The channel is rigidly attached to the mast so that rotation of the wind-driven mast captured by the blades causes rotation of the coil also about the longitudinal axis at the same speed as the mast. The coil forms a spiral around the longitudinal axis, Z, with turns succeeding one another at a given pitch. Thus, by the inclination of the mast and the coil, the air entering through the upstream opening on the surface of the water body is driven with each rotation of the coil to a downstream turn, to reach the opening swallows. The upstream opening (4u) is preferably adjacent and parallel to the longitudinal axis, Z. This allows it to be kept out of the water during rotation of the coil. In a preferred variant, illustrated in Figure 1, the upstream opening is coaxial with the longitudinal axis, Z. The mast is fixed directly to the channel at the upstream opening.

The coil can form a circular helix, extending along a cylinder and in which all the turns have the same diameter. However, the channel walls are not designed to withstand the surrounding hydrostatic pressure which increases with each successive turn with the immersion depth under water. The walls are sufficiently flexible so that the pressure inside the channel is in equilibrium with the pressure outside the channel. The air is compressed as it moves towards the downstream opening of the canal by sinking deeper under the water. For this reason, it is preferable that the diameter of the turns decreases between the upstream opening (4u) and the downstream opening (4d), so that the volume of the channel in each successive turn decreases proportionally to the decrease in the volume of air which compresses down to the downstream opening. For example, the coil may form a conical spiral as illustrated in Figure 1, that is to say a spiral inscribed in a cone or truncated cone. The diameter of the turns, however, does not necessarily decrease linearly along the longitudinal axis, Z, and can evolve, for example, in a substantially elliptical manner, as illustrated in FIG.

Also to compensate for the decrease in the volume of compressed air during its course along the successive turns of the coil by the hydrostatic pressure of the surrounding water, preferably the section of the channel decreases when approaching the opening swallows. An example of a coil whose channel section decreases with immersion depth is shown in Figure 2.

An anchor (6) is placed at the bottom of the water to fix the wind turbine to its service position. The anchor is coupled to a bearing (5) and to the coil adjacent to the downstream opening. The bearing (5) attached to the anchorage allows, on the one hand, the rotation of the coil around the longitudinal axis, Z, and, on the other hand, the rotation of the longitudinal axis about a vertical axis , X2, so that the wind turbine can orient itself "backwind" according to the direction of the wind (see the direction of the wind indicated by the arrow, W, in Figures 1-3 & 5).

As shown in Figure 1, the bearing can be fixed directly to the coil in a plane normal to the longitudinal axis, Z. In Figure 1, it is attached to the outer surface of the coil, it is that is, the area farthest from the longitudinal axis, Z. It is clear that it can be perfectly attached to the inner surface of the coil, that is, the nearest surface and facing the the longitudinal axis, Z. In these two configurations, the bearing must be coupled to the anchor by means of a ball joint or a cardan joint allowing the rotation of the longitudinal axis, Z, around the vertical axis, X2.

In an alternative embodiment, illustrated in Figure 2, the bearing (5) can be fixed directly to the anchor for the rotation of a vertical beam. This is coupled to a universal joint (or simply "cardan") for driving the rotation of said vertical beam by transmitting the rotation of the coil about the longitudinal axis, Z, which is inclined at an angle , Θ, with the horizontal axis, X1. The gimbal can be homokinetic type or not. In the case of a non-homokinetic gimbal, two such gimbals can be arranged to one another to obtain a homokinetic transmission. However, homokinetic rotation transmission is not essential to the realization of the present invention.

As illustrated in Figure 1, the channel may be formed of a closed tube (that is to say, whose section is closed, eg, O-shaped or □) which is rolled up to form a coil.

In one embodiment, portions of preformed closed tubes in the form of turns may be nested within each other, such as a mechano, in order to facilitate transportation at sea in parts, and to form the coil in situ, where the wind turbine will be installed. In an alternative embodiment illustrated in Figure 2, the channel is formed of portions of open channels (i.e. those whose section is open, eg U-shaped), which can nest not only end-to-end, but also from one turn to the other, the closed portion of a turn interlocking in the open portion of the section of an adjacent turn. The open channel portions have a tire shape cut transversely. In order to ensure the stability of the adjacent turns nested one to the other, a support cable (4c) can be stretched between the mast and the anchor. Such a cable (4c) may also be used in the case of closed tube-formed channels, but the stability of the turns is less critical than in the case of channels formed of open channel portions.

The coil can form a rigid structure, but it is preferred that this is not the case. Indeed, it is better to design the coil so that it can deform a little according to the force and direction of the currents and the wind, which can be very violent, rather than to conceive a rigid structure that can yield to the forces to which it would be subject. A flexible structure is therefore preferred. A flexible structure must, however, be rigid enough to maintain a serpentine geometry, but if it can be locally deformed by the action of currents and winds: the turns that can be detached from each other (in the case of closed tubes), the turns being able to lose their circularity locally under the effect of a constraint, but they must find it again when the stress decreases or disappears. It should also be avoided that the channel is clogged by local bending. Reinforcements may be used to locally stiffen the section of the channel. For example, hoops can be placed at regular intervals. Reinforcing fibers of glass, carbon, aramid or metal may also be introduced into the walls of the channel. A flexible structure is also more economical than a rigid structure. For this reason, the walls of the channel can be made of polymers, preferably elastomers as used for example in the tire industry. A cable (4c) ensuring the stability of the turns between them will thus be preferred to a rigid beam.

Finally, the floating wind turbine of the present invention comprises ballast (7) attached to an outer surface of the channel. Preferably, the ballast is attached to an inner surface of the coil, facing the longitudinal axis, Z (i.e. in the inner cavity defined by the coil as schematically shown in Figure 3 (b) (For the sake of clarity, the ballast is not shown in the other figures.) Ballast is essential to the operation of the floating wind turbine because the air trapped in the upper parts of the coils of the coil (shown in FIG. shaded in Figure 3 (a)) exert an upward vertical force on the coil, which must be taken up by the anchor.For larger installations, the forces would be too great to consider traditional anchorage. allows to compensate for the flotation force related to the presence of air in the channel Ideally, the ballast is sized so that the effort on the anchor is practically nil in calm sea and in the absence of ven The ballast may consist of sand, gravel, or stones securely packed and stowed on one surface of the coil, preferably on the inner surface of the coil, facing the longitudinal axis, Z. When the ballast is well dimensioned, the longitudinal axis, Z, of the wind turbine placed on a body of water with the bearing anchored in the bottom of the plane forms an angle, Θ, with the horizontal axis, X1, and the mast, one or more blades and the upstream opening of the canal are out of the water while the downstream opening and the landing are submerged.

In summary, the floating wind turbine may comprise two, three or four blades distributed around the mast according to the chosen blade geometry, non-exhaustive examples of which are illustrated in Figure 4. The floating wind turbine in position d ' use at its longitudinal axis, Z, inclined, forming an angle, Θ, with the horizontal axis, X1, less than 85 °, preferably less than 75 °, still preferably less than 60. The angle, Θ, is, however, greater than 20 °, preferably greater than 30 °, more preferably greater than 40 °. An angle, Θ, of 45 ° + 20 ° is preferred. The bearing (5) allows the rotation of the wind turbine about its longitudinal axis, Z, and the anchorage (6) to which the bearing is coupled allows the rotation of the longitudinal axis, Z, about the vertical axis, X2, to allow the wind turbine to orient itself "back to the wind" according to the direction of the wind. This double rotation can be achieved either by rigidly coupling the bearing to the coil and coupling it to the anchor by means of a ball joint. Alternatively, the bearing can be mounted to the anchor by a branch of a cardan joint.

System for Generating and Storing Energy The floating wind turbine of the present invention is advantageously used in an energy capture and storage system comprising, in addition to a floating wind turbine as described above, a storage tank (8) fixed in the bottom of the body of water and for storing air transported from the upstream opening to the downstream opening of the channel by the rotation of the coil. As shown in Figure 3 (a), the air entering through the upstream opening (4u) into the coil channel, in attempting to rise to the surface, sticks to the highest walls of the channel forming a first turn of the coil. The rotation of the coil causes the air pocket thus formed to a lower zone. The air then rises, but is stuck to the highest walls of the channel forming a second turn of the coil, adjacent to the first. The void created in the first turn is quickly filled by a new volume of air forming a new air pocket. In reality it is a continuous process and one can not distinguish one "pocket of air" from another. But following the path of an individual "air pocket" along the canal, this allows a better understanding of the mechanism causing the air from the surface to the bottom of the body of water. The air pocket thus spins turn in turn with each rotation of the coil until reaching the last turn including the opening down (4d) where it leaves the channel.

While the air pocket goes deeper into the channel, the hydrostatic pressure of the surrounding water increases rapidly with depth. Since the channel walls are sufficiently flexible to deform under the effect of hydrostatic pressure in the surrounding water, the air compresses down the channel at a pressure in equilibrium with the hydrostatic pressure of the surrounding water. . When the air comes out through the downstream opening, it is in equilibrium with the pressure of the surrounding water.

The air leaving the channel through the downstream opening is retained in the storage tank (8). For installations of great power, requiring the storage of a large quantity of air, the dimensions of the tank are such that it is preferable to use a tarpaulin (8b) fixed to the bottom of the body of water, such as illustrated in Figures 1-3, 5 & 6, and thus defining a storage volume between the tank and the bottom of the body of water. The cover comprises an orifice (8h) to accommodate the downstream opening of the channel under the sheet and in the storage volume. As the air rises, it is necessary for the air to leave the channel, that the downstream opening is not the lowest point of the channel at least during a fraction of a rotation of the coil about the longitudinal axis , Z, which is referred to as the rotation evacuation fraction. The orifice (8h) of the sheet must have dimensions such that: (a) they allow a 360 ° rotation of the coil around the vertical axis, X2, and (b) the downstream opening (4d) is under the tarpaulin at least during the rotation evacuation fraction.

With these two conditions, the air conveyed from the surface to the downstream opening (4d) can be removed from the channel and stored under the sheet for all directions of the wind. To prevent the air from coming out from under the tarpaulin and back to the surface through the orifice (8h) it must be at a low point of the tank. Tensioners can be provided to keep the perimeter of the orifice at a lower position than the volume of air held under the sheet. However, it is necessary to avoid that the tensioners are in the path of the exit opening (4d) during its revolutions around the longitudinal axis, Z. As illustrated in Figure 1, these conditions can be achieved by anchoring a perimeter of anchoring the sheet surrounding the orifice (8h) and extending a sufficiently rigid awning from this anchoring perimeter, defining the opening of the orifice (8h). Alternatively as illustrated in Figure 3 (a), a flexible skirt extending from said anchor perimeter may surround the coil. Otherwise, simply as shown in Figure 2, the perimeter of the orifice (8a) is anchored by means of cables attached to an anchor point through a return, to clear a perimeter allowing the rotation of the opening downstream of the channel without it taking itself in cables.

In a variant illustrated in Figure 7, the cover (8b) receiving the downstream opening (4d) of the wind turbine channel and / or the upstream opening (40u) of the outlet channel (40) (described in FIG. in the following chapter), may have a reduced dimension compared to the volume of compressed air to be stored by connecting the sheet through a system of distribution pipes (17) to peripheral balls (15) of smaller dimensions distributed on a perimeter surrounding the tarpaulin. As shown in FIG. 7, the peripheral balloons are anchored to the bottom of the body of water, either by cables connected to a mass (6b), for example made of concrete, or preferably by filling the bottom of the sand balloons or other ballast (6s) such as stones, leaving a sufficient volume for air storage occupying an upper portion of the peripheral balloons.

By a principle of communicating vessels, part of the air stored under the sheet is transferred into peripheral balloons distributed around the sheet so that the air level is at all times substantially the same under the sheet and in the peripheral balloons (see dotted line marking the air level represented in shaded area). Valves (17v) can, if necessary, control air transfers from the tarpaulin to the peripheral balloons. Such valves are not essential for the distribution of air between the different elements of the storage tank (8b, 15). However, they allow to isolate a peripheral balloon from the rest of the network in case of leaks or other failures. Valves also provide more flexibility in that the total storage volume of an installation can be adapted to the immediate circumstances of wind and energy consumption required. The use of peripheral balloons is advantageous in that it makes it possible not to cover continuously a too large surface of the seabed, which would inevitably cause a major disruption of the fauna and flora. Repairing damaged structures of small size is usually easier than for very large structures.

The air stored under the sheet and in the peripheral balloons can be placed in fluid communication by the same system of distribution pipes (17) a system (10) for generating electricity by means discussed in detail in the following chapter, as shown in Figure 7. A system (10) for generating electricity allows, by various means, to generate electricity by bringing to the surface air stored at the bottom of the plane of water. A single valve (17v) between said power generation system and the various elements of the storage tank makes it possible to control the moment, the duration and the flow of air admitted to go up to the surface of the body of water.

Stored Energy Recovery System and Electric Power Transformation [0038] The floating wind turbine and the storage tank are capable of capturing and storing wind energy in the form of compressed air stored at depth. The system becomes complete if the stored energy can be recovered on demand and transformed into electrical energy. For this, the system of the present invention advantageously comprises an energy recovery device (10) for guiding air stored in the storage tank to the surface of the body of water, resulting in its passage rotation ( 9) of an electric power generator or a turbine.

In a first variant of the invention illustrated in Figure 5 (a), the energy recovery device (10) comprises an outlet channel (40) forming a coil similar to the channel (4) of the wind turbine which under the action of the air stored in the storage tank and up through the serpentine outlet channel, is rotated (in the opposite direction of the coil of the wind turbine). The coil of the outlet channel is coupled to a current generator (9) activated by the rotation of the coil. The outlet channel (40) forming a coil extending along an axis of rotation, Z1, comprising an air inlet opening (40u) through which air enters and an air outlet opening (40d) where it exits the output channel. The outlet channel is coupled to a bearing (50) anchored to the bottom of the water body by an anchorage (60) allowing the coil to rotate about its axis of rotation, Z1, with the inlet opening located in the storage volume and outlet opening being located outside the storage volume, preferably on the surface or out of the water body. The inclination and the dimensions of the coil of the outlet channel (40) are similar to those of a floating wind turbine as described above. In order to control the air supply of the outlet channel and thus the rotation of the outlet channel and the generator, means (80) for transferring air stored in the storage volume to the inlet opening of the flow channel. The lower outlet is arranged adjacent to the inlet opening. For example, the transfer means may comprise an Archimedean screw or a rotating serpentine channel which may be activated by a motor. The transfer means is coupled to the anchor (60) so that the output of the transfer means is always in front of (and below) the inlet opening (40u) of the outlet channel. be the orientation of the wind or currents. An output channel makes it possible to restore the energy stored by several floating wind turbines. For example, there may be a return coil for four, five or six floating wind turbines (see Figure 6 (b)).

In an alternative variant illustrated in FIG. 5 (b), the energy recovery system (10) makes it possible to release air stored in the storage tank and to bring it up to the surface along the an evacuation tube coupled to a turbine which activates a generator (9). The discharge tube (11) comprises a first opening (11u) located in a vertically high point of the storage tank and a second opening (11d) coupled to the turbine positioned near or on the surface of the water body and activated by the passage of air in the evacuation tube. A valve (11v) located between the first and second openings (11u, 11d) makes it possible to control the flow of air in the evacuation tube and thus the level of electric current generation.

In another variant illustrated in Figure 7 (b), wherein the storage tank (8) comprises a cover (8b) connected by upstream distribution pipes (17u) to the peripheral balloons (15). The latter are kept close to the bottom of the body of water by means of a cable passing through a deflection pulley (13) fixed to the seabed and rising to the surface to be fixed to the axis of a generator. current (9) located near or on the surface of the body of water. As described above, a portion of the compressed air collected under the sheet (8b) can be transferred to the peripheral balloons (15) through the upstream distribution pipes and valves (17v). When a balloon is full of air and there is a demand for electric current, simply release the idler pulley and let the balloon rise to the surface (see the balloon (15) the rightmost at Figure 7 (b)). The rise of the balloon causes the rotation of the axis of the current generator (9) which thus produces current. When the balloon has reached the surface of the body of water, it is sufficient to empty the air that it contains and to bring it empty in the bottom of the body of water, to reinflate it with air stored under the tarpaulin. .

Exemplary Embodiment [0042] As illustrated in FIG. 6 (a), a wind turbine (1) with oblique axis equipped with blades (2) of length, L2, of 135 m develops a power of about 5 MW for a wind of 10 m / s at a height of the blades, H2, 10 m above the surface of the body of water. Coupled with a serpentine channel (4) whose first turn (adjacent to the upstream opening (4u)) has a diameter, D1, of 20 m for a height, H4, 280 m long, anchored at a depth, H, 210 m, the system absorbs this power and stores it in the form of compressed air in the storage tank formed by a tarpaulin (8b) stowed at the bottom of the body of water.

As illustrated in Figure 6 (b), the wind turbine described above can be part of a wind farm comprising several similar floating wind turbines. As the wake effect of oblique-axis wind turbines is reduced compared to a conventional vertical-axis wind turbine, the anchors (6) of the serpentine channels can be spaced from each other by a distance, d1, of 400 m, which is much lower than the distance required between two vertical mast wind turbines of the same power, which can be of the order of 1000 m approximately.

The energy recovery device (10) can be placed in the center of the device. An energy recovery device (10) in the form of a serpentine output channel is shown in Figure 6 (b). It is clear that other types of energy recovery devices (10) can be used instead. The power of the generator (9) is of the order of 5 to 10 MW depending on the sites and the temporal distribution of the wind speeds. The generator must be sized according to the ratio between the average wind speed as measured on this site and the reference speed of 10 m / s.

The tarpaulin surface forming the storage tank (8) may have an area of 7 to 8 ha to store the equivalent of 7 days of electricity produced by the 5 MW generator operating at a yield of 40% of average load. In this configuration, the system could therefore continue to provide the network despite a complete absence of wind for a full week. This configuration therefore makes it possible to respond to the problem, on the one hand, of the intermittency of the wind and, on the other hand, of modulation of the power injected as a function of the demand.

Table 1 shows for illustrative ranges of values for the various dimensions of a floating wind turbine according to the present invention.

Table 1: Examples of dimensions of a floating wind turbine according to the present invention

As explained above, it is preferred that the radius of the turns and the pitch between two successive turns decrease with the depth, to reduce the volume of the channel as a function of the compression of the air. In the case of a conical spiral-shaped coil comprising n turns, the pitch, pi, between the ith and the (i + 1) th turn and the diameter, Di, of 17 turn by the following parametric equation. If x, y, z are defined as: x =% Di. cos (2π.η); y =% Di sin (2π.η); and z = J pi dt, with i between 1 and n, we can then calculate the pitch, pi, of the coil between the ith and the (i + 1) th turn and the diameter, Di, of the I turn, as follows:

where pi and D1 are the pitch and the diameter for i = 1, corresponding to the first turn adjacent to the upstream opening (4u).

The wind turbine of the present invention has many advantages: (a) It comprises very few moving parts, thus reducing the handling and the changes of worn parts required in an aggressive off-shore environment. (b) It can operate over a wider range of wind speeds than wind turbines with horizontal or vertical axis of rotation. (c) It allows the storage of the accumulated energy according to the wind force, to restore it on demand, thus separating the wind variations from those of the demand. (d) In the case where the rendering device (10) comprises a serpentine outlet channel (40), its rotation can be electrically activated by using the generator in order to rotate it in the opposite direction and thus to bring about air from the surface into the storage tank; this makes it possible to store the current coming from the network in the form of compressed air in the event of an overload of current of the network. (e) In a different application, the wind turbine may also be used to pump water from a downstream basin to another upstream basin, by mounting the coil on landings; the coil can then form a circular helix (i.e., inscribed in a cylinder). (f) It increases the number of wind turbines per grid line since the line is no longer sized to carry the peak power but the average power of wind turbines. For a ratio of four between peak power and average power it amounts to dividing the marginal cost of interconnection by four.

Claims (10)

A floating wind turbine (1) comprising: (a) one or more blades (2) rigidly attached to a mast (3) extending along a longitudinal axis, Z, such as the exposure of the blade or blades to the wind causes rotation of the mast about the longitudinal axis, Z, (b) a channel forming a coil (4) extending along the longitudinal axis, Z, and comprising an upstream opening (4u) and a downstream opening (4d), the channel being fixed rigidly to the mast so that when the mast rotates at a speed, v1, about the longitudinal axis, Z, the coil also rotates about the longitudinal axis at the same speed v1 (c) a bearing (5) attached adjacent to the downstream opening for rotation of the coil about the longitudinal axis, Z, (d) an anchor (6) for anchoring the bearing in the bottom of a plane of water, (e) ballast (7) attached to an external surface of the channel, such as when the wind turbine is placed on a body of water with the bearing anchored in the bottom of the body of water, the longitudinal axis, Z, forms an angle, Θ, with a horizontal axis, X1, and the mast, one or more blades and the upstream opening of the channel are out of the water and the downstream opening and the landing are immersed. 2. A floating wind turbine according to claim 1, wherein the channel forms a coil formed of successive turns whose diameter decreases away from the upstream opening to the downstream opening, or linearly, forming a conical spiral, • be substantially elliptical. 3. A floating wind turbine according to claim 2, wherein the section of the channel decreases from the upstream opening to the downstream opening. 4. Wind turbine according to any one of the preceding claims, selected from wind turbines with a three-blade rotor, Darrieus type, or helical type. 5. A system for generating and storing energy, comprising: • a floating wind turbine (1) according to any one of claims 1 to 3 anchored in the bottom of a body of water by the anchor and • a reservoir of storage (8) fixed in the bottom of the body of water and for storing air transported from the upstream opening to the downstream opening of the channel by the rotation of the coil. 6. System according to claim 5, wherein the storage tank comprises a tarpaulin (8b) attached to the bottom of the body of water thus defining a storage volume between the tank and the bottom of the body of water, the tarpaulin comprising a orifice (8h) to accommodate the downstream opening of the channel in the storage volume. 7. System according to claim 5 or 6, wherein the floating wind turbine comprises two, three or four blades distributed around the mast and wherein: • the longitudinal axis, Z, forms an angle, Θ, with a horizontal axis, X1, less than 85 °, preferably less than 75 °, more preferably less than 60 ° and wherein: • the angle, Θ, is greater than 20 °, preferably greater than 30 °, still preferably greater at 40 °, and wherein, • the anchoring allows the longitudinal axis, Z, to rotate about a vertical axis, X2. 8. System according to any one of claims 5 to 7, further comprising an energy recovery device (10) for guiding air stored in the storage tank to the surface of the body of water, resulting in through its passage the rotation of a generator (9) of electric current. The system of claim 8, wherein the device comprises: an outlet channel (40) forming a coil extending along an axis of rotation, Z1, and comprising an inlet opening of air (40u) and an air outlet opening (40d), the outlet channel being fixed to the bottom of the body of water by a bearing (50) allowing the coil to rotate about its axis of rotation, Z1, with the inlet opening in the storage tank and the outlet opening being located outside the storage tank, preferably on the surface or out of the water body, and further comprising: 80) stored in the storage volume to the inlet opening of the outlet channel, preferably the transfer means comprises an Archimedean screw or a rotating serpentine channel, or a distribution pipe , and • a generator (9) of electric current activated by the rotation of the coil of the output channel. The system of claim 8, wherein the device comprises a discharge tube (11) comprising a first opening (11u) located in a vertically high point of the storage volume and a second opening (11d) coupled to a turbine electric current generator positioned near or on the surface of the water body and activated by the passage of air in the evacuation tube, and wherein the evacuation tube is further provided with a valve located between the first and second and second openings.