FR2925129A1 - DEVICE FOR CONVERTING THE ENERGY OF THE WAVES INTO RECUPERATIVE ENERGY - Google Patents

Abstract

The invention relates to a device (1) for converting wave energy into recoverable energy, said device comprising a floating shell structure (2) which encloses mass-forming means (3), the shell (2) and the means ( 3 according to the invention, said mass means (3) comprise, in the out-of-water position of said device, at least one element (5) rotatably mounted with respect to the shell (2) and, in the partially immersed position of said device, at least said element (5) rotatably mounted relative to the shell (2) and a liquid volume (4) at least partially filling the shell (2) in at least a part of which said rotatably mounted element (5) is at least partially immersed, said rotatably mounted element (5) causing, during its rotation, a displacement of at least a portion (4A) of the filling liquid .

Description

The present invention generally relates to devices for converting wave energy into electrical energy.

The invention more particularly relates to a device for converting wave energy into recoverable energy, said device comprising a floating shell structure which encloses mass means, the shell and the mass means being able to be driven by a movement. relative.

These devices, known as "wave energy" devices, are particularly interesting because they make it possible to produce electricity from a renewable energy source (the potential and kinetic energy of the waves) without emission of greenhouse gases. . The interest of wave energy is even more important in connection with the supply of electricity to isolated island sites.

It is known from the state of the art and in particular from WO 2006/040341 conversion devices as described above. In such conversion devices, the mass means comprise heavy solid elements rotatably mounted relative to the shell. Such heavy solids require a large volume of material which increases the cost of the conversion device. In addition, these heavy solid elements exert, because of their weight, significant efforts on the running gear and on the supporting structure of said elements. It is thus necessary to size the conversion device so that the rolling members and the supporting structure are sufficiently robust to support the weight of these mass elements. Such dimensioning is expensive in material.

In addition, in such conversion devices, the wall of the floating shell structure must be dimensioned so that it supports the pressure forces exerted by the waves. As a result, the thickness of the wall of the floating structure is often large, which increases the cost of manufacturing such a conversion device. The object of the present invention is to propose an energy conversion device whose cost is reduced while retaining a robust conversion device and whose energy return rate is sufficient. In particular, the object of the invention is to reduce the material cost of the mass-forming means.

Another object of the invention is to design an energy conversion device in which the establishment of the mass forming means is facilitated. Another object of the present invention is to reduce the apparent pressure forces experienced by the wall of the floating structure.

Another object of the present invention is to reduce the stresses on the supporting structure of the mass means and the members, such as bearings or plain bearings providing rotation between the shell and the mass means.

To this end, the invention relates to a device for converting wave energy into recoverable energy, said device comprising a floating shell structure which encloses mass means, the shell and the mass means being able to be animated. relative movement, characterized in that said mass means comprise, in the out of water position of said device, at least one element rotatably mounted relative to the shell and, in the partially immersed position of said device, at least said element rotatably mounted relative to the shell and at least a partial volume of filling liquid of the shell, in at least a portion of which said rotatably mounted member is at least partially immersed, said rotatably mounted member driving, during its rotation, a moving at least a portion of the filling liquid.

The energy is recovered by a recovery system driven by the relative movement between the shell and the mass element. This recovered energy is either electrical type or mechanical type. For example, the energy recovered in mechanical form can be used to operate a seawater desalination device or be converted into hydraulic energy.

With the conversion device according to the invention, a portion of the mass means is formed by the filling liquid, which reduces the material cost of the mass means while maintaining a sufficient weight of said means. Such a design mass means also facilitates their implementation in the device since, in the case where the liquid portion is seawater, it can be introduced once the device installed at sea .

The use of the filling liquid also makes it possible to distribute part of the weight of the mass-forming means on the inner wall of the shell, which makes it possible to relieve the members providing the mobility between the rotatably mounted element and the shell, as well as the bearing structure of the rotatably mounted element.

Preferably, the filling liquid is contained in a compartment at least a portion of the walls is common with the wall of the shell.

Thus, the filling liquid generates on at least a portion of the inner side of the shell wall a hydrostatic pressure substantially equal and opposite to the hydrostatic pressure experienced by the outer side of the corresponding wall of the hull. The resultant hydrostatic pressure forces exerted on said wall of the shell is therefore significantly reduced. In addition, the hydrodynamic forces exerted on the hull by the waves, in particular on the front face of the hull, are distributed over a large part of the hull via the filling liquid present in said hull, the filling liquid being, of course, incompressible preference. These two effects make it possible to limit the dimensioning of the shell, that is to say to reduce the thickness of the shell and associated stiffeners and thus to limit the amount of material used.

In addition, the use of a rotary member allows to freeze means for limiting the stroke of the mass means in case of strong waves.

According to another advantageous characteristic of the invention, said or each rotatably mounted element is a paddle wheel preferably comprising at least six vanes.

Thus, during the relative rotation between the shell and the impeller, the filling liquid that extends between two blades is driven by the blades in a rotational movement substantially identical to that of the impeller. The material cost of the mass means is thus significantly reduced since said liquid, for example seawater, forms part of these means. According to another advantageous characteristic of the invention, the flanks of the impeller are equipped with flanges so as to contain at least a part of the filling liquid between the vanes of the wheel and to promote the rotational drive by the blades of said portion of the filling liquid.

According to another advantageous characteristic of the invention, said or each rotatably mounted element comprises weighting means whose center of gravity is situated outside the axis of rotation of the rotatably mounted element.

The use of ballasting means associated with the rotatably mounted member allows the mass means to behave as an oscillating pendulum, preferably of which the resonance frequency will be chosen according to the excitation of the waves in order to amplifying the relative rotational movement of the mass means with respect to the shell and thus the production of recoverable energy. According to another advantageous characteristic of the invention, said or each rotatably mounted element resting on a supporting structure, said or each rotatably mounted element comprises at least one float, preferably diametrically opposed to the weighting means when said weighting means are present. said float compensating for at least a portion of the force due to the weight of the or each rotatably mounted member on said supporting structure.

Preferably, the float is immersed at least partially in the filling liquid. Thus, the force resulting from the weight of the rotatably mounted element and the weighting means on the structure carrying said element is reduced or even canceled. In addition, the addition of float makes it possible to adjust the physical characteristics of the pendulum formed by the mass means, such as the resonance frequency of said pendulum.

According to another advantageous characteristic of the invention, there is provided a device for recovering the energy resulting from the relative displacement of the shell and mass means, the recovery device being mounted inside the shell.

According to a particular embodiment of the invention, the energy recovery device is an electric generator comprising at least two members respectively forming the stator and the rotor of the electric generator, one of the two members being mounted together. in rotation of the shell, the other member being mounted integral in rotation with said or each element 20 rotatably mounted mass means.

According to a particular embodiment of the invention, of the type in which said device comprises means for limiting the rotation of a portion of said filling liquid relative to the shell, the electric generator is at least partially immersed in the part of the filling liquid whose rotation is limited relative to the shell by said means for limiting rotation.

According to another particular embodiment of the invention, of the type in which the floating structure comprises at least two separate compartments, one of which, preferably ballastable, houses said mass means, the electric generator is mounted in the other compartment, substantially dry, of the shell. According to another advantageous characteristic of the invention, it is further provided at least locking means adapted to immobilize, relative to the shell, said or each rotatably mounted element of the mass means and means for controlling the blocking means for selectively blocking or releasing said one or each rotatably mounted member so as to amplify the movement of the mass means by continuously adjusting the dynamics of the device to the waves. Preferably, the blocking means is formed when the relative speed of the rotatably mounted element relative to the shell is substantially zero.

According to another advantageous characteristic of the invention, the mass-forming means and the shell are arranged such that the device, in the partially immersed state at sea, naturally moves in a position according to which the axis of rotation of the the rotatably mounted member is substantially horizontal and perpendicular to the main wave propagation direction.

According to a particular embodiment of the invention, the shell comprises a portion of cylindrical shape, partially or totally immersed in operational position, whose horizontal axis is oriented, naturally or because of the design of the mooring of the conversion device, substantially perpendicular to the direction of propagation of the swell. The mass means are housed in this cylindrical portion and the axis of rotation of the rotating member of the mass means is parallel and preferably coincides with the axis of said cylinder.

According to another particular embodiment of the invention, said device comprises means for limiting the rotation of a portion of said filling liquid relative to the shell. Said rotation limiting means may be formed by integral vanes in displacement of the shell and which extend, preferably, radially relative to the axis of rotation of the or each rotatably mounted element.

Advantageously, the shell structure is compartmentalized and delimits, on the one hand, a so-called main compartment, preferably cylindrical and ballastable, and, on the other hand, at least one so-called auxiliary compartment provided with said means for limiting the rotation and filled at least partially, in the partially immersed position of said device, a part of the filling liquid, said auxiliary compartment being preferably cylindrical and of axis coincides with the main compartment when it is cylindrical.

Preferably, said cylindrical portion of the shell is divided into three compartments, a so-called central compartment and two so-called lateral compartments, each centered on the axis of said cylinder. The mass means are located in the central compartment of said cylinder. The energy recovery device associated with the mass means may be located either in the central compartment or in a lateral compartment. Preferably, the lateral compartments are at least partially filled with liquid, such as seawater, so that the hydrostatic and hydrodynamic forces exerted on the outer side of the shell by the waves are compensated by the forces exerted on the inner side of the hull by the liquid contained in said lateral compartments. Thus, the walls of the cylinder, which also form the walls of the central compartment and the lateral compartments, are subjected to a substantially identical hydrostatic pressure on the outer side and on the inside of each of said walls of the cylinder, and on a substantially hydrodynamic pressure difference. reduced when the compartments are filled with a substantially incompressible liquid. Preferably, the lateral compartments are themselves sub-compartmentalized so that the shell is able to rotate the liquid present in said lateral compartments. The lateral compartments then form the so-called auxiliary compartments which are provided with means for limiting the rotation of a part of the filling liquid relative to the shell. The side compartments may further comprise a sub-3s so-called buoyancy compartment, filled with air, so as to adjust the floatation state of the conversion device. The invention will be better understood on reading the following description of exemplary embodiments, with reference to the appended drawings in which: FIG. 1 is a perspective view of the energy conversion device according to the invention; in partially submerged position; - Figure 2 is a sectional view along a plane transverse to the axis of rotation of the energy conversion device according to a particular embodiment of the invention; - Figure 3 is a sectional view along a plane transverse to the axis of rotation io of the energy conversion device according to another embodiment of the invention; FIG. 4 is an axial sectional view of the energy conversion device according to the invention, the generatrix being disposed in the same compartment as the mass-forming means and immersed in the filling liquid; - Figure 5 is an axial sectional view of the energy conversion device according to the invention, the generator being disposed in a separate dry compartment of the compartment housing the impeller; FIG. 6 is a view of the device of FIG. 5 according to an alternative embodiment, the compartment housing the generator being filled with liquid; - Figure 7 is a cross-sectional view A-A of a compartment, filled with liquid, the device of Figure 6, said figure showing the means for immobilizing said liquid relative to the shell of the device.

FIGS. 1 and 2 show a device 1 for converting wave energy into recoverable energy, comprising a floating shell structure 2 which encloses mass means 3. The shell 2 and the means 3 forming mass are able to be driven by a relative movement under the action of the waves on the shell 2. The recovered energy is either of the electric type to power an electric motor, or mechanical type to directly actuate a mechanical member or actuate, via a hydraulic circuit, a hydraulic motor. In the example illustrated in the figures and as detailed below, the energy recovered is of the electric type.

As illustrated in FIGS. 4 to 6, the energy conversion device also comprises a device 8 for recovering the energy resulting from the relative displacement of the shell 2 and the mass means 3.

Characteristically according to the invention, said mass means 3 comprise, in the out-of-water position of said device, at least one element 5 rotatably mounted relative to the shell 2 and, in the partially immersed position 10 of said device, at least said element 5 rotatably mounted relative to the shell 2 and a volume of liquid 4 at least partially filling the shell 2, in at least a portion of which said rotatably mounted element 5 is at least partially immersed. Said rotatably mounted element 5 causes, during its rotation, a displacement of at least one part 4A of the filling liquid 15 around the axis of rotation A1 of said rotatably mounted element 5.

In the example illustrated in the figures, said rotatably mounted element 5 is a paddle wheel 5 having six vanes. The impeller is mounted integral with a shaft 11 which is rotatably mounted relative to the shell 2. The impeller 5 forms, in cooperation with the filling liquid 4A, a pendulum when the center of gravity of the forming means mass is off-center with respect to the axis of rotation Al of the impeller 5 or a flywheel when said center of gravity is centered on said axis of rotation Al of the impeller 5.

In the example illustrated in the figures, said rotatably mounted element 5 causes, during its rotation, a displacement of a portion 4A of the filling liquid 4. Said device 1 also comprises means 18 for limiting the rotation of the other part 4B of said filling liquid 4 with respect to the shell 2. As illustrated in FIG. 7, said means 18 for limiting the rotation of the other part 4B of said filling liquid 4 with respect to the shell 2 are formed by fins 18 secured to displacement of the shell 2. As illustrated in FIGS. 2 to 6, each blade extends radially to the vicinity of the wall 2. Such a design of the blades forces the filling liquid 4A to move at the same time as the vanes and vice versa. In addition, as illustrated in FIG. 4, the flanks of the impeller 5 may be equipped with flanges 19 so as to contain at least one part 4A of the filling liquid between the blades of the wheel 5 and to favor the drive in rotation by the blades of said portion 4A of the filling liquid 4.

As illustrated in FIGS. 2 to 7, the shell 2 comprises an upper part 2A partially filled with air, to allow the floatation of the conversion device, and a lower part 2B which houses the mass forming means 3 and the recovery device 8. 'energy. Part 2A may be compartmentalized to receive seawater ballast or ballast, which may be placed on the face, said front, of the hull, forming a bow, in particular to strengthen this part 2A with respect to the hydrostatic and hydrodynamic forces that she suffers.

Said shell 2 is closed, but it is preferably provided with one or more orifices for at least partial filling of the shell by said filling liquid 4 in which the paddle wheel 5 is immersed. Each filling orifice is, of course, closable. .

The lower part 2B of the shell is preferably of cylindrical shape.

In operational position of the device at sea, the axis of said cylinder is horizontal and oriented, naturally or because of the design of the mooring of the conversion device, substantially perpendicular to the direction of propagation of the swell. The axis A1 of the rotary element 5 of the mass means 3 is parallel and preferably coincides with the axis of said cylinder.

In the example illustrated in FIG. 5, the cylindrical lower portion 2B is divided into three compartments, a so-called central compartment 12 and two lateral compartments 13A, 13B, each centered on the axis of said cylinder. The mass means are located in the central compartment 12 of said cylinder. The energy recovery device 8 associated with the mass means is here located in the lateral compartment 13A. Alternatively, as detailed below and illustrated in Figure 4, the energy recovery device 8 and the mass means can be housed in the same compartment. Preferably, the filling liquid 4 used is seawater. The conversion device can thus be transported easily, "dry", then brought to its implantation site at sea, before being filled. at least partially of seawater in partially submerged position. According to a particular embodiment illustrated in FIG. 3, the impeller 5 also comprises weighting means 6 whose center of gravity is situated outside the axis of rotation A1 of the impeller 5. The addition ballasting means 6 makes it possible to off-center the center of gravity of the mass-forming means 3 with respect to the axis of rotation A1 of the impeller 5 so as to give the mass-forming means 3 the characteristics of a pendulum.

The impeller 5 also comprises at least one float 7, preferably diametrically opposed to the ballasting means 6, so as to compensate at least in part for the weight loads of the weighting means 6 on said impeller 5. The stresses The bearings on bearings, bearings or bearings that rotate relative to hull 2 and impeller 5 are therefore also reduced. Similarly, the forces exerted on the supporting structure of the impeller 5 are reduced. Preferably, the float 7 is sized to compensate for the weight of the impeller 5 and the weighting means 6.

In the example illustrated in FIG. 3, the float 7 forms a volume which connects two vanes to one another and whose face oriented towards the inner wall of the shell 2 extends substantially to the vicinity of said inner wall. Similarly, the weighting means 6 connect two blades to each other and said weighting means also extend substantially to near the inner wall of the shell 2. Thus, in the rest position, the impeller 5 is provided, in the lower part, weighting means and, in the upper part, flotation means which allows to generate a return torque of the impeller 5 in the rest position. Such a return torque promotes the relative displacement of the shell 2 and the impeller 5. Indeed, the assembly comprising the impeller 5, the filling liquid 4A and the weighting means 6 and flotation 7 form a pendulum whose movements are amplified when the excitation frequency of the waves is close to the resonant frequency of this pendulum.

The weighting and flotation means may also take the form of tubes, parallel to the Al rotation axis, respectively filled with dense materials and light material or fluid, such as air or nitrogen.

Alternatively, it can be provided that the impeller 5 is devoid of weighting means. The pendulum is in this case formed by the float 7 in cooperation with the liquid 4 and the impeller 5.

In the example illustrated in FIGS. 4 to 6, the recovery device 8 is formed by an electric generator 8 mounted inside the shell 2.

The electric generator 8 comprises at least two members 9, 10 respectively forming the stator 9 and the rotor 10 of the electric generator 8. One of the two members is mounted to rotate with the hull 2 and the other member is mounted to rotate with the impeller 5.

Of course, the name of rotor and stator depends on the fixed reference chosen, since the rotational movement of the shell and mass means is relative. In the remainder of the description, the fixed reference frame chosen is the shell 2. As a result, the rotor of the generator is the member mounted to rotate with the impeller 5 and the stator 9 is the integral mounted member. in rotation of the shell 2. In a variant, the paddle wheel could be considered as a fixed reference, the member of the generator mounted to rotate with the hull 2 would then be the rotor and the member mounted to rotate with the wheel paddle 5 would be the stator.

s It can be provided that the electric generator 8 is at least partially immersed in the filling liquid 4. In the example illustrated in FIG. 4, the electric generator 8 is housed in the same compartment 12 as the impeller 5. Alternatively, as illustrated in FIG. 6, it is possible to isolate the electric generator 8 in a compartment 13A separate compartment 12 housing the impeller 5, while maintaining said generator immersed. In the example illustrated in FIG. 6, the lower part 2A of the shell then comprises at least three separate compartments 12, 13A and 13B. The central compartment 12 houses the impeller which is immersed at least partially in the filling liquid 4. The at least partial immersion of the electric generator allows a natural and economic cooling of said generator. This characteristic is particularly advantageous in the case where the inductive magnetic field of the electric generator is generated by means of magnets, which, if they are subjected to a temperature above a critical operating temperature, risk being demagnetized. The at least partial immersion of the electric generator also makes it possible to dispense with forced air ventilation units and thus increase the reliability of operation of the electric generator. In addition, such a design 25 limits the size of said device.

The generator can be completely submerged, including its air gap. The parts sensitive to the stator are then preserved attacks seawater, using, for example, an oil bath. As illustrated in Figure 4, the rotation 30 between the rotor 10 and the stator 9 of the generator 8, as well as the rotation between the shaft 11 and the shell 2, are provided by smooth bearings 14, preferably rendered insensitive to the attacks of sea water, which are lubricated by the sea water forming the filling liquid. Thus, it is not necessary to seal the rolling members mounted on the rotating shaft of the rotatably mounted element.

It can also be provided that the electric generator comprises a system 5 for discharging the filling liquid 4 infiltrated into said generator.

This provides a particularly simple device requiring very little maintenance. The cylinder may also be made of a composite material that is not very sensitive to the effects of seawater. It is also possible to provide a cathodic protection system for the elements of the device for conversion against seawater and / or to treat the seawater. seawater forming liquid filling to reduce its corrosive power.

In the example illustrated in the figures, the rotor of the electric generator is in direct contact with the shaft of the impeller. The rotor of the electric generator is thus driven directly in rotation relative to the stator, by the rotation of the mass means relative to the shell, which eliminates a hydraulic recovery circuit.

In the example illustrated in FIGS. 6 and 7, the compartment 13B is provided with fins 18 whose configuration makes it possible to limit the rotation of the liquid 4B with respect to the shell 2. The fins 18 extend radially with respect to the Al axis and over the entire length of the cylindrical compartment 13B. The liquid taken between two fins 18 is thus forced to move together with the shell 2 when the latter is rotated by the action of the waves. The immobilization of a portion 4B of the filling liquid relative to the shell makes it possible to increase the rotational inertia of the shell 2. It is also possible that the compartment 13A in which the generator is housed is provided with such means of limitation of the rotation of the liquid with respect to the shell. The fins extend for example in this case, radially, from the inner wall of the compartment to the generator.

As a variant of the example illustrated in FIG. 6, it can be provided, as illustrated in FIG. 5, that the compartment 13A housing the electrical generator 8 is substantially dry and leakproof with respect to the central compartment 12 which houses the impeller 5. Since said compartment 13A is sealed, it is possible to use simple bearings 15 between the rotor and the stator of the generator. As an alternative, it is possible to use an orientation ring between the rotor and the stator, which makes it possible to use only one running member between the rotor and the stator of the generator.

It is intended to dispose the blocking means of the mass-forming element in the other lateral compartment 13B, either dry or immersed.

As illustrated in FIG. 5, seals 17, mounted on the rotational shaft of the impeller 5, can be used to seal the compartments 13A and 13B with respect to the central compartment 12. It is then possible to use bearings 16 instead of plain bearings to ensure rotation between the impeller and the hull.

All compartments of the conversion device that can be at least partially immersed are ballastable and deballastable with a liquid such as seawater.

In addition, the conversion device is equipped with appendices that give the conversion device the desired buoyancy. The shell of the device is also shaped to present surfaces responsive to the excitation of the waves so as to optimize the rotational movement between the shell and the mass means.

Preferably, as illustrated in FIGS. 4 to 6, the electric generator 8 and the impeller 5 being axially offset along the axis of rotation A1, there is provided means 11A for recovering the angular and / or radial clearance between the axis of the generator 8 and the axis Al of the rotatably mounted element. In addition, when the axis of the generator 8 and the axis Al of the rotatably mounted element are off-axis, the recovery means 11A serve as coupling means for driving the rotor 9 of the generator by the element rotatably mounted.

The electric generator may consist, on the one hand, of a plurality of electric windings arranged on a stator ring, integral in rotation with the shell, and, on the other hand, with a rotor, integral in rotation with the impeller, generating a magnetic field of excitation which can be produced by permanent magnets or electric windings, or which can be induced by a cage.

The electric generator may also be a generatrix with variable magnetic reluctance formed, on the one hand, of a plurality of electric windings disposed on the stator, integral in rotation with the shell, and, on the other hand, a assembly of magnetic sheets of variable diameter forming a toothed rotor, integral in rotation with the impeller, said assembly of magnetic sheets generating a variable magnetic reluctance opposite said windings. Alternatively, it can be provided that the rotor or stator of the generator is not engaged directly with the axis of rotation of the impeller. There is then provided a speed reduction gear system between the axis of rotation of the generator and the axis of rotation of the impeller. The conversion device may further comprise at least locking means capable of immobilizing, with respect to the shell 2, the impeller 5 and means for controlling the blocking means for selectively blocking or releasing the impeller. blades 5 so as to amplify the movement of the mass means 3.

The amplification of the movement of the mass means 3 is obtained by immobilizing the impeller 5 in unfavorable periods of its oscillation cycle and its release when the initial conditions for its subsequent movement are more favorable and allow to amplify this one. In particular, the control means are able to control the locking means so that they block the impeller 5 when it reaches a relative speed substantially zero relative to the hull. Processing means determine an optimal blocking delay of the impeller 5, as a function of the values of the dominant frequency of excitation of the waves. The control means then control the locking means to unlock the impeller 5 when the timer has reached the optimal time. Such a locking and unlocking method is described in more detail in WO 2006/040341 and can be applied here for blocking and unblocking the impeller with respect to the hull.

Thus, blocking the impeller 5 for a predetermined time has the effect of changing the overall dynamics of the conversion device 1 by continually adapting it to the form of the excitation generated by the movement of the waves. Such a method of blocking and unblocking the mass means with respect to the shell makes it possible to increase the energy recovery rate of the incident waves.

The electric power supplied by the electric generator 8 can be conventionally transmitted to the ground by means of an underwater cable connected to the conversion device. The present invention is not limited to the embodiments described and shown, but the skilled person will be able to make any variant within his mind.

Alternatively, the energy recovery device may be formed by a conventional hydraulic system comprising hydraulic pumps coupled to the impeller and supplying hydraulic oil under pressure, via a hydraulic accumulator, a motor-alternator unit.

Alternatively, the mass means may comprise a plurality of rotating members, such as paddle wheels, which bathe in the same volume of liquid or in separate liquid volumes, each paddle being then housed. in a separate compartment from the other paddle wheels. The apparatus proposed does not require a fixed external reference, unlike some devices of the prior art which require the installation of a tethered anchor or superstructures attached to the seabed. The anchoring of the device, s can This is similar to mooring a boat at anchor or a floating structure.

It is also possible that the shell of the device has the same characteristics as those of the conversion device described in WO 2006/040341. In particular, it can be provided that the shell is profiled so that, when the device is immersed in water, it is naturally oriented with respect to the main wave propagation direction V (see FIGS. to obtain maximum stress of the mass means. 15

Claims (14)

Apparatus (1) for converting wave energy into recoverable energy, said device comprising a floating shell structure (2) which encloses mass means (3), shell (2) and means (3) forming a mass being able to be moved relatively, characterized in that said means (3) forming a mass comprise, in the out of water position of said device, at least one element (5) rotatably mounted relative to the hull ( 2) and, in the partially immersed position of said device, at least said element (5) rotatably mounted relative to the shell (2) and a liquid volume (4) for at least partial filling of the shell (2), in at at least a part of which said rotatably mounted element (5) is at least partially immersed, said rotatably mounted element (5) causing, during its rotation, a displacement of at least a portion (4A) of the filling liquid (4) . 2. Device (1) according to claim 1, characterized in that said or each element (5) rotatably mounted is a paddle wheel (5) preferably having at least six vanes. 3. Device (1) according to claim 2, characterized in that the flanks of the impeller (5) are equipped with flanges (19) so as to contain at least a portion (4A) of the filling liquid between the blades of the wheel (5) and to promote the rotational drive by the vanes of said portion (4A) of the filling liquid (4). 4. Device (1) according to one of claims 1 to 3, characterized in that said or each element (5) rotatably mounted comprises means (6) weighting whose center of gravity is located off the axis of rotation (Al) of the rotatably mounted element (5). 5. Device (1) according to one of claims 1 to 4, of the type wherein said or each element (5) rotatably mounted rests on a supporting structure, characterized in that, said or each element (5) rotatably mounted comprises at least 5 a float (7), preferably diametrically opposed to the means (6) of ballasting when said weighting means are present, said float (7) compensating for at least a portion of the effort due to the weight of or each element (5) rotatably mounted on said supporting structure. 6. Device (1) according to one of the preceding claims, characterized in that said device (1) comprises means (18) for limiting the rotation of a portion (4B) of said liquid (4) relative to to the hull (2). 10 7. Device (1) according to the preceding claim, characterized in that said means (18) for limiting the rotation are formed by fins (18) integral displacement of the shell (2) and which extend, preferably , radially relative to the axis of rotation of the or each element (5) rotatably mounted. 15 8. Device (1) according to one of claims 6 and 7, characterized in that the shell structure is compartmentalized and defines on the one hand a compartment (12) said main, preferably cylindrical and ballastable, and, d on the other hand, at least one auxiliary compartment (13A, 13B) provided with said means (18) for limiting rotation and at least partially filled, in the partially immersed position of said device, with a part of the filling liquid (4). , said auxiliary compartment (13A, 13B) being preferably cylindrical and of axis coincident with the main compartment (12) when it is cylindrical. 25 9. Device (1) according to one of the preceding claims, characterized in that it comprises a recovery device (8) of the energy from the relative displacement of the shell (2) and means (3) forming mass , the recovery device (8) being mounted inside the shell (2). 10. Device (1) according to the preceding claim, characterized in that the energy recovery device (8) is an electric generator (8) comprising at least two members (9, 10) respectively forming the stator (9). and the rotor (10) of the electric generator (8), one (9) of the two members being mounted to rotate with the shell (2), the other member (10) being rotatably mounted on said or each element (5) rotatably mounted means (3) forming mass. s 11. Device (1) according to the preceding claim, of the type wherein said device (1) comprises means (18) for limiting the rotation of a portion (4B) of said liquid (4) filling relative to the hull (2), characterized in that the electric generator (8) is at least partially immersed in the part (4B) of the filling liquid (4) whose rotation is limited with respect to the shell (2) by said means (4). 18) limiting the rotation. 12. Device (1) according to claim 10, of the type in which the floating structure comprises at least two separate compartments (12, 13A), one of which said main (12), preferably ballastable, houses said means (3) forming Mass, characterized in that the electric generator (8) is mounted in the other compartment (13A), substantially dry, of the shell (2). 13. Device (1) according to one of the preceding claims, characterized in that it comprises, in addition, at least locking means adapted to immobilize, with respect to the shell (2), said or each element ( 5) rotatably mounted means (3) forming mass and means for controlling the locking means for selectively blocking or releasing said or each element (5) rotatably mounted, so as to amplify the movement of the means (3) forming mass. 25 14. Device (1) according to one of the preceding claims, characterized in that the mass forming means and the shell are arranged such that the device, in the partially immersed state at sea, is naturally oriented in a position wherein the axis of rotation of the rotatably mounted member is substantially horizontal and perpendicular to the main direction of wave propagation.