FR3093542A1 - ENERGY RECOVERY SYSTEM IN A MOVING FLUID - Google Patents

Abstract

------ ENERGY RECOVERY SYSTEM IN A MOVING FLUID The invention relates to an energy recovery system (1) in a moving fluid, said system (1) comprising anchoring means (4) at a fixed point with respect to the moving fluid, a means of flotation (5) in the moving fluid and at least one flexible connection (7a, 7b) connecting the flotation means (5) to the anchoring means (4), the flotation means (5) floating in the fluid in movement above the anchoring means (4), characterized in that said system (1) further comprises at least one sealed housing (6) attached to at least one flexible connection (7a, 7b), each sealed housing (6) comprising, inside the latter, an energy recovery device (11) capable of recovering energy by movement of the sealed housing (6) associated in the moving fluid. Figure to be published with the abstract: Figure 1

Description

ENERGY RECOVERY SYSTEM IN A MOVING FLUID

The present invention relates to the field of energy harvesting, and relates in particular to a system for harvesting energy in a moving fluid.

In order to satisfy the increasing demand for energy, while trying to reduce the consumption of fossil energy resources, other energy resources are currently being exploited, such as solar energy, wind energy or solar energy. tidal.

Solar energy currently requires semiconductor devices, which are complex to design and have a short lifespan. Solar energy comes mainly in the form of photovoltaic panels currently requiring semiconductor devices that require a lot of energy to manufacture. In addition, solar electricity generation is limited to available periods of sunshine, is not available at all at night, and is significantly reduced during cloudy weather.

Wind energy requires large mechanical systems to provide sufficient energy, which are expensive to design and install, and generate rotational noise in use (wind turbines generate noise pollution).

Tidal power can generate large amounts of power with large mechanical systems arranged either inshore or offshore. The disadvantage of these systems is that they must be in contact with moving water, which involves frequent maintenance and generates wear and corrosion in said mechanical systems. Therefore, these systems also have a limited lifespan.

Other devices have been developed which recover energy from the ambient environment either thermally such as heat pumps or kinetically by mechanical devices recovering energy from the accidental movement of other systems, such as a dynamo on a bicycle for example. However, these devices are very inefficient or very unreliable.

British patent application GB2459843A discloses a set of water turbines mounted on a flexible shaft between a means of attachment to the seabed and a float, said set of water turbines being immersed in moving water and allowing the recovery of electrical energy by rotating water turbines in moving water. However, water turbines are in direct contact with water, which causes fouling, wear and corrosion of said water turbines which thus have a limited lifespan. In addition, each water turbine makes it possible to recover energy only along a single axis of rotation, namely the axis of rotation of the water turbine, which does not allow optimal recovery of energy. Indeed, the vibrations induced by vortex undergone by the water turbines are not used in an optimal way to make it possible to transform into electrical energy all the movements undergone by the water turbines according to all the possible directions of displacement. In addition, this set of water turbines also does not allow to achieve a damping of the amplitude of the vortex-induced vibrations.

The present application aims to solve the drawbacks of the prior state of the art, by proposing a system for recovering energy in a moving fluid, said system comprising at least one energy recovery device arranged in a sealed box fixed at least one flexible connection between an anchoring means and a flotation means. The energy harvesting device is thus autonomous, makes it possible to generate electrical energy by movement of the sealed casing in all possible directions in the unstable environment of the moving fluid, comprises a robust mechanism and is isolated from the environment. exterior through the waterproof housing to enable longer life and lower maintenance costs.

The subject of the present invention is therefore a system for recovering energy in a fluid in motion, said system comprising means for anchoring to a fixed point with respect to the fluid in motion, a means of flotation in the fluid in motion and at the least one flexible link connecting the buoyancy means to the anchoring means, such that when the energy recovery system is installed in a moving fluid, the buoyancy means floats in the moving fluid above the anchoring means, characterized in that said system further comprises at least one waterproof casing fixed to the at least one flexible connection, each waterproof casing comprising, inside the latter, a device for recovering energy capable of recovering energy by movement of the associated sealed casing in the moving fluid, said energy recovery device comprising: - a body designed to move relative to the associated sealed casing; - first and second aligned input shafts projecting from two opposite sides of the body; - a first pendulum mounted on the distal end of the first input shaft; - a second pendulum mounted on the distal end of the second input shaft; - an output shaft whose direction is perpendicular to the direction of the first and second input shafts; - a bearing fixed inside the associated waterproof casing, in which the distal end of the output shaft is freewheeling; - a third input shaft aligned with the output shaft, the direction of the third input shaft being perpendicular to the direction of the first and second input shafts, a distal end of the third input shaft being fixed to the inside the associated waterproof case; - mechanical connection means at the proximal end of each of the first, second and third input shafts which are inside the body, said mechanical connection means operating with a transmission system arranged inside of the body such that any rotational movement on any of the first, second and third input shafts is converted into unidirectional rotational movement on the output shaft; - an alternator connected to the output shaft and configured to convert the unidirectional rotational movement of the output shaft into electrical energy; and - at least one electrical load connected to the alternator, each electrical load being configured to store or consume electrical energy produced by the alternator.

In the present application, the terms "distal" and "proximal" for a shaft end are defined with respect to the body, the distal end of a shaft being the end of the shaft which is farthest from the body. , and the proximal end of a shaft being the end of the shaft which is closest to the body.

It should be noted that the third input shaft and the output shaft are preferably mounted coaxially.

The energy recovery device according to the invention is thus designed such that its body moves around its third input shaft fixed inside the associated sealed box, and has two pendulums on its first and second shafts opposite input shafts, which pendulums move around the body through their respective input shafts.

An energy recovery device making it possible to convert any rotational movement on any one of the three input shafts into a unidirectional rotational movement on a single output shaft is described in detail in PCT international application WO2015/044296A2 by the same inventor and incorporated by reference herein.

An advantage of the energy recovery device is that, when it is fixed inside the sealed casing disposed in the moving fluid, the body moves relative to the sealed casing, and the pendulums move relative to the body. , which generates motion converted into energy on the output shaft. This means that the energy harvesting device according to the invention can generate energy by itself, when its sealed casing is left in the unstable environment of the moving fluid. The energy harvesting device thus makes it possible to generate electrical energy by harvesting the energy of movement of its sealed case in all possible directions in the moving fluid.

When the energy recovery system is installed in the moving fluid, the flotation means floats in the moving fluid above the anchoring means, the buoyancy of the flotation means in the moving fluid being due to the Archimedean thrust experienced by the flotation means in the fluid in motion. The flotation means thus makes it possible to pull the at least one flexible connection upwards so as to tension the latter. The at least one sealed casing can thus be subjected to the currents of the moving fluid, which causes the at least one sealed casing to move in the moving fluid due to the flexibility of the at least one flexible connection . The anchoring means makes it possible to retain the lower part of the energy recovery system in the moving fluid.

The flotation means can either be completely submerged in the moving fluid or float on the surface of the moving fluid, depending on the length of the at least one flexible link.

The anchoring means is preferably anchored to the ground (such as a seabed), but could also be anchored to any structure disposed in the moving fluid, without departing from the scope of the present invention.

The energy recovery device is arranged inside the casing which is sealed in a leaktight manner, so as to prevent fouling and erosion of the metal elements of the energy recovery device by the moving fluid (such as than a marine environment), which thus makes it possible to extend the life of the energy recovery device and thus to reduce its maintenance costs.

The energy recovery system according to the invention is also an economical and scalable solution in order to be suitable for many environments.

The at least one flexible connection can either consist of any number of flexible connections connecting the various elements together, or consist of a single flexible connection to which all the elements are fixed.

The body of the energy harvesting device and the associated waterproof casing are preferably both spherical in shape, the first and second input shafts being on one of the diameters of the sphere, the end of the weight of each of the pendulums facing the body being curved in a complementary manner to the shape of the body to be capable of pivoting around the body. The pendulums can thus rotate around the body at 360°.

It should be noted that the body and the waterproof case could also have any other shapes, as long as the pendulums can pivot around the body. The pendulums are designed so that, whatever the position of the pendulum relative to the body, the weight of the pendulum does not come into contact with any of the shafts, to allow maximum pivoting movement of the pendulums around the body, and thus a maximum production of energy. The shape of the pendulums is designed so that it does not interfere with the shape of the body when rotating around their respective shafts, such that they can rotate, up to 360°, around their respective shafts .

Either the pendulums can swing independently of each other, or the pendulum weights are rigidly connected so that they swing synchronously around their respective shafts.

The alternator of the energy recovery device makes it possible to convert the mechanical energy supplied by the output shaft into electrical energy, said electrical energy then being stored and/or consumed by the at least one electrical load connected to the alternator.

According to a particular characteristic of the invention, the at least one electrical load is at least one of at least one battery, one electrical power cut-off resistor, at least one sensor, one cathodic protection device configured to imposing a current on a metallic element on or in the at least one sealed casing in order to prevent cathodic erosion, and an external electrical connection to the exterior.

Thus, when the electrical load is a battery, the latter makes it possible to store the electrical energy produced by the alternator.

Power conversion means are preferably disposed between the alternator and the at least one electrical load for converting AC power generated by the alternator into DC power which may, for example, be stored in one or more batteries.

When the electrical load is a sensor, the latter is powered by the electrical energy produced by the alternator in order to allow its detection operation.

When the electrical load is a cathodic protection device, the latter is supplied by the electrical energy produced by the alternator in order to impose a current on a metallic element on or in the sealed casing so as to fight against cathodic erosion. and soiling of said metal member, thereby extending the life of the equipment and reducing maintenance costs.

When the electrical load is an external electrical connection, the latter is preferably arranged on the outer surface of the sealed casing and electrically connected to the alternator to allow the electricity generated by the energy recovery device to be used outward.

When the electrical load is a power supply cut-off resistor (from the Anglo-Saxon term “load dump resistance”), the latter makes it possible to disconnect a powered load such as a battery powered by the alternator.

According to a particular characteristic of the invention, all or part of the at least one electrical load is located in at least one of the pendulums, and dynamic power transfer means are arranged between the alternator and said at least one pendulum.

Thus, the arrangement of at least a part of the electrical load, such as one or more batteries, in the pendulum or pendulums makes it possible to make the energy recovery device compact. The dynamic power transfer means allow transfer of electric current between the alternator and the at least one electrical load part disposed in the pendulum(s), said dynamic power transfer means comprising, for example, slip rings.

According to a particular characteristic of the invention, the means of mechanical connection of the first, second and third input shafts to the transmission system are one or more elements among toothed gear wheels, toothed chains, toothed sprockets, belts and pulleys.

According to a particular characteristic of the invention, the transmission system between the means of mechanical connection of the first, second and third input shafts and the output shaft comprises one or more elements from among toothed gear wheels, chains gears, sprockets, belts and pulleys.

Thus, the mechanical connection means and the transmission system constitute a robust and entirely mechanical mechanism.

According to a particular characteristic of the invention, the anchoring means is connected to the at least one flexible connection by one of a rigid connection and an articulated connection, said anchoring means being one of a mass placed at said fixed point and a mass fixed to said fixed point.

Thus, the anchoring means is either fixed at the fixed point in the moving fluid, or just laid at the level of the fixed point in the moving fluid and held in position only because of its high weight.

In the case where the anchoring means is connected to a flexible link by an articulated connection, the latter does not allow the bending forces to be transferred to the flexible link.

According to a particular characteristic of the invention, the flotation means is one of a float, a buoy, a floating platform or structure, an oil platform and a balloon.

The flotation means can thus be any buoyant structure or any submerged structure having positive buoyancy in the moving fluid, the flotation means being partially or completely submerged in the moving fluid depending on the length of the flexible connection.

In the case of a float, a buoy or an oil platform, the moving fluid can, for example, be a marine environment.

In the case of a balloon, the fluid in motion can, for example, be the Earth's atmosphere.

Floating structures can, for example, also be large office structures floating on the sea, or houses floating on the sea made, for example, using concrete and steel containers.

According to a particular characteristic of the invention, the at least one flexible connection is at least one of at least one flexible pipe, at least one flexible cable, at least one flexible riser pipe, at least one flexible drill pipe and at least one flexible umbilical cord.

In the case of a flexible connection of the flexible pipe type, the flexible pipe is preferably made of high density polyethylene, is preferably filled with sea water when the moving fluid is a marine environment, and has , preferably a circular cross-section.

When the energy recovery system is used in the field of offshore oil production, the flexible link can be a riser (from the Anglo-Saxon term “riser”), a drill string (from the Anglo-Saxon term “ drill string”) or an umbilical cord (from the Anglo-Saxon term “umbilical”), connecting an oil platform to the bottom of the sea.

According to a first embodiment of the invention, said system comprises one of a single sealed box fixed, preferably, at the center of the length of the flexible connection and a single pair of sealed boxes fixed, preferably, at the center the length of the flexible link on either side of the flexible link.

Thus, the single sealed housing or the single pair of sealed housings is preferably fixed at the central point of the flexible link, or at the point of the flexible link where the maximum deflection occurs.

In the case of a pair of waterproof boxes, one of the waterproof boxes is fixed on one side of the flexible link, and the other of the waterproof boxes is fixed on the other side of the flexible link at the same height , which makes it possible to prevent an asymmetrical movement of the assembly.

According to a second embodiment of the invention, said system comprises one of a plurality of sealed boxes fixed, preferably, in a distributed manner on the flexible connection and a plurality of pairs of sealed boxes fixed, preferably, in a distributed over the flexible connection, the two sealed boxes of a pair of sealed boxes being arranged on either side of the flexible connection.

Thus, multiple sealed boxes or pairs of sealed boxes can be fixed at different heights on the flexible link, preferably in a distributed manner over the length of the flexible link.

The sealed housings are preferably attached to the flexible link at multiple points where maximum deflection of the flexible link occurs.

It should be noted that said system could also comprise one or more sets of four sealed boxes, the four sealed boxes of the same set being fixed at the same height on the flexible connection and distributed around the flexible connection, without deviating within the scope of the present invention.

According to a particular feature of the invention, the at least one sealed casing is configured to be set in motion by vortex-induced vibrations caused by the moving fluid.

Thus, the movement of the at least one sealed casing is driven by vortices (or vortex detachment) around the flexible connection above and below the sealed casing, these vortices cause an oscillation at a certain frequency which depends on the diameter of the flexible connection, the mass of the flexible connection, the flow velocity, etc.

However, these vortex-induced vibrations can lead to fatigue damage of vibrating structures, such as subsea risers that experience vortex-induced vibrations, which presents a significant problem for the offshore petroleum industry.

According to a particular characteristic of the invention, the at least one electrical load connected to the alternator is configured to slow down the rotational movement of the output shaft so as to slow down the rotational movement of the input shafts in order to reducing the amplitude of vortex-induced vibrations experienced by the at least one sealed housing.

Thus, the at least one electrical load allows a damping of the vortex-induced vibrations undergone by the at least one flexible connection.

The electric load, which has a given value which loads the alternator, slows down the output shaft and so limits the movement of the pendulums, these pendulums being initially excited by the vortex-induced vibrations, so that the energy removed reduces the range of motion of the sealed housing and thereby reduces the magnitude of vortex induced vibrations experienced by the flexible linkage.

The energy recovery device is in this case used to generate an opposing force on the sealed casing by applying a given electrical load to the alternator. This electric charge creates an opposing force with respect to the direction of movement of the sealed housing, which makes it possible to reduce the movement of the sealed housing and therefore of the flexible connection at the level of the sealed housing. The level of motion damping can thus be modified by controlling the electrical load connected to the alternator.

According to a particular characteristic of the invention, the at least one electrical load is one of a precalculated fixed load, a preprogrammed variable load, and an active load controlled externally or on board using a control unit. inertial measurement.

Thus, the damping of vortex-induced vibrations can be passive (using the pre-calculated fixed load or the pre-programmed variable load) or active (using the active load).

The fixed load is calculated beforehand and the variable load is programmed beforehand so as to maximize the damping of vortex-induced vibrations in the moving fluid.

Likewise, the active load is controlled in real time so as to maximize the damping of vortex-induced vibrations in the moving fluid.

The active load is either controlled externally acoustically or by cable, or controlled on board using machine learning, an inertial measurement unit allowing real-time measurement of the position and acceleration of the waterproof housing of so as to control the active load accordingly.

The present invention also relates to the use of a system for recovering energy in a moving fluid as described above in an underwater environment.

Thus, in this case, the fluid is movement is a marine environment undergoing marine currents. The anchoring means is preferably placed on the seabed or fixed thereto. The flotation means is partially or totally immersed in the sea, which makes it possible to pull the flexible connection upwards in order to tension it.

The sea currents set the at least one waterproof casing in motion, which makes it possible to recover electrical energy via the energy recovery device.

The energy recovery device can also be used to dampen the amplitude of the vortex-induced vibrations experienced by the flexible link in order to limit its wear over time.

To better illustrate the object of the present invention, a description will be given below, by way of illustration and not of limitation, of preferred embodiments, with reference to the appended drawings.

In these drawings:

is a front view of an energy recovery system according to a first embodiment of the invention;

is a front view of an energy recovery system according to a second embodiment of the invention;

is a front view of an energy recovery system according to a third embodiment of the invention;

is a perspective view of part of the energy recovery system of Figure 3;

is a perspective view of a sealed case of the energy harvesting system of the present invention, in which is disposed an energy harvesting device;

is a partially cut-away perspective view of the body of the energy harvesting device according to the present invention, with two pendulums;

is a perspective view of the body of the energy recovery device of Figure 6 without its casing;

is a top view of Figure 7;

is a bottom view of Figure 7; and

is a sectional view of Figure 7 according to the output shaft of the energy recovery device.

If we refer to Figure 1, we can see that there is shown an energy recovery system 1 according to a first embodiment of the present invention.

The energy recovery system 1 is installed in a marine environment and undergoes the sea currents of the marine environment. Reference numeral 2 represents the seabed of the marine environment, while reference numeral 3 represents the sea surface of the marine environment.

It should be noted that the energy recovery system 1 could also be installed in any other moving fluid, without departing from the scope of the present invention.

The energy recovery system 1 comprises a means of anchoring to the seabed 4 constituted by a mass placed on the seabed 2.

It should be noted that the anchoring means 4 could also be fixed to the seabed 2 or to any underwater structure, without departing from the scope of the present invention.

The energy recovery system 1 further comprises a means of flotation 5 and a waterproof casing 6 comprising, inside the latter, an energy recovery device (not represented in FIG. 1) able to recover electrical energy by movement of the waterproof case 6 in the marine environment (said energy recovery device will be described in more detail in Figures 5 to 10).

The energy recovery system 1 further comprises a first flexible connection 7a connecting the anchoring means 4 to the waterproof casing 6 and a second flexible connection 7b connecting the waterproof casing 6 to the flotation means 5.

The anchoring means 4 is connected to the first flexible connection 7a by a rigid connection, but could also be connected to the first flexible connection 7a by an articulated connection in which case the latter does not allow the bending forces to be transferred to the first flexible link 7a, without departing from the scope of the present invention.

It should be noted that the energy recovery system 1 could also comprise a single flexible connection connecting the anchoring means 4 to the flotation means 5, the waterproof casing 6 then being fixed to the single flexible connection, without deviate from the scope of the present invention.

The flotation means 5 is a float which floats in the marine environment above the anchoring means 4, the buoyancy of the flotation means 5 in the marine environment being due to the Archimedes thrust undergone by the latter in the marine environment. The flotation means 5 of the float type thus makes it possible to pull the flexible connections 7a, 7b upwards so as to stretch them. The waterproof case 6 can thus undergo the sea currents of the marine environment, which causes the movement of the waterproof case 6 due to the flexibility of the flexible connections 7a, 7b, which makes it possible to recover electrical energy by the intermediary of the energy recovery device arranged in the sealed casing 6.

The flotation means 5 of the float type has been shown fully submerged in Figure 1, but could also float on the surface of the sea 3 in the case where the flexible links 7a, 7b are longer, without deviating from the frame of the present invention.

It should be noted that the flotation means 5 could also be any floating or submerged structure having positive buoyancy in the marine environment, such as a buoy, a floating platform or a balloon, without departing from the scope of the present invention.

The energy recovery device being arranged inside the waterproof casing 6 which is sealed in a leaktight manner, this makes it possible to avoid fouling and erosion of the metal elements of the energy recovery device by the marine environment. , which thus makes it possible to extend the life of the energy recovery device and thus to reduce its maintenance costs.

The first and second flexible connections 7a, 7b are flexible pipes, preferably made of high density polyethylene, filled with sea water and of circular cross-section.

It should be noted that the flexible links 7a, 7b could also be flexible cables, without departing from the scope of the present invention.

The lengths of the first and second flexible links 7a, 7b are identical such that the waterproof casing 6 is arranged at the center of the energy recovery system 1. However, the lengths of the first and second flexible links 7a, 7b could also be different, without departing from the scope of the present invention. The waterproof casing 6 could, for example, be placed at the height where the maximum deflection occurs in the marine environment.

The sealed box 6 could also be replaced by a pair of sealed boxes 6 fixed between the first and second flexible links 7a, 7b, without departing from the scope of the present invention.

The waterproof case 6 can be set in motion in the marine environment by vortex-induced vibrations (or vortex shedding) occurring around the flexible links 7a, 7b above and below the waterproof case 6, these vortices causing an oscillation at a certain frequency which depends on the diameter of the flexible links 7a, 7b, the mass of the flexible links 7a, 7b, the flow velocity, etc.

If we refer to Figure 2, we can see that there is shown an energy recovery system 8 according to a second embodiment of the present invention.

The common elements between the energy recovery system 1 according to the first embodiment of the invention in FIG. 1 and this energy recovery system 8 according to the second embodiment of the invention bear the same figure of reference, and will not be described in more detail here when they are of identical structures.

The energy recovery system 8 according to the second embodiment comprises three waterproof boxes 6, each of the waterproof boxes 6 comprising an energy recovery device inside it. A first flexible connection 7c connects the anchoring means 4 and a first sealed casing 6, a second flexible connection 7d connects the first sealed casing 6 to a second sealed casing 6, a third flexible connection 7e connects the second sealed casing 6 to a third waterproof casing 6, and a fourth flexible connection 7f connects the third waterproof casing 6 to the flotation means 5.

It should be noted that the energy recovery system 8 could also comprise a single flexible connection connecting the anchoring means 4 to the flotation means 5, the three sealed boxes 6 then being fixed to the single flexible connection, without s depart from the scope of the present invention.

Each of the flexible links 7c, 7d, 7e, 7f is a flexible pipe but could also be a flexible cable.

The energy harvesting system 8 could also comprise any number of sealed boxes 6, without departing from the scope of the present invention.

The flexible links 7c, 7d, 7e, 7f all have the same length so that the sealed boxes 6 are arranged in a distributed manner over the height of the energy recovery system 8.

It should be noted that the flexible links 7c, 7d, 7e, 7f could also have different lengths, without departing from the scope of the present invention. The sealed boxes 6 can, for example, be arranged at different heights in the marine environment at which maximum deflection of the flexible links 7c, 7d, 7e, 7f occurs.

Each sealed box 6 could also be replaced by a pair of sealed boxes 6 fixed between the two associated flexible connections, without departing from the scope of the present invention.

The energy recovery system 8 according to the second embodiment thus makes it possible to recover a greater quantity of electrical energy due to the fact that it comprises several sealed boxes 6 and therefore several energy recovery devices.

Referring to Figures 3 and 4, it can be seen that there is shown an energy recovery system 9 according to a third embodiment of the present invention.

The common elements between the energy recovery system 1 according to the first embodiment of the invention in FIG. 1 and this energy recovery system 9 according to the third embodiment of the invention bear the same figure of reference, and will not be described in more detail here when they are of identical structures.

In this third embodiment, the flotation means 5 is an offshore oil platform floating on the surface of the sea 3, but could also be any platform or structure floating on the surface of the sea 3, without deviating from the scope of the present invention.

In addition, in this third embodiment, the energy recovery system 9 comprises a single flexible connection 7 connecting the anchoring means 4 to the flotation means 5 of the oil platform type.

The single flexible link 7 is a flexible riser (from the Anglo-Saxon term “riser”), but could also be a flexible pipe, a flexible cable, a flexible drill string (from the Anglo-Saxon term “drill string”) or a flexible umbilical cord (from the Anglo-Saxon term “umbilical”), without departing from the scope of the present invention.

In this third embodiment, a pair of waterproof boxes 6 is fixed at a certain height on the flexible connection 7 of the riser type using a fixing device 10, the two waterproof boxes 6 of the pair of boxes sealed 6 being arranged on either side of the flexible connection 7, which prevents asymmetrical movement of the assembly.

The pair of sealed housings 6 are preferably fixed at the point of the flexible link 7 at which the maximum deflection occurs.

It should be noted that the energy recovery system 9 could also comprise any number of pairs of waterproof boxes 6, each fixed at a different height on the flexible connection 7 of the riser type, without deviating from the frame of the present invention.

The fixing device 10 comprises a first support element 10a fixed to one of the sealed boxes 6 and a second support element 10a fixed to the other of the sealed boxes 6, and two holding rods 10b arranged on either side another of the flexible connection 7 and connecting the first and second support elements 10a so as to block the position of the fixing device 10 on the flexible connection 7 at the desired height.

It should be noted that the fixing device 10 could also be suitable for fixing any number of waterproof boxes 6 at a desired height on the flexible link 7 (for example, a single waterproof box or four waterproof boxes), without deviating within the scope of the present invention.

Each sealed box 6 comprises, inside it, an energy recovery device 11 which will be described in more detail later in Figures 5 to 10.

The two energy recovery devices 11 thus make it possible to recover electrical energy by movement of the flexible connection 7 and therefore of the sealed boxes 6 in the marine environment, but can also be used to dampen the amplitude of the vibrations induced by vortices undergone by the flexible connection 7 in order to limit its wear over time as will be described in more detail below.

If we refer to Figure 5, we can see that there is shown the sealed box 6 in which the energy recovery device 11 is arranged.

The sealed case 6 has been shown in transparency in Figures 4 and 5 so as to show the energy recovery device 11 arranged inside it.

The waterproof case 6 preferably has a spherical shape, but could also have any other shape, without departing from the scope of the present invention.

The energy recovery device 11 comprises a substantially spherical body 12 designed to move relative to the sealed casing 6, and two pendulums 13 designed to move relative to the body 12. The internal elements of the body 12 are protected by a casing 12a.

The energy recovery device 11 makes it possible to convert any rotational movement on any one of three input shafts into a unidirectional rotational movement on a single output shaft, such as that described in detail in the international application PCT WO2015/044296A2 by the same inventor.

If we refer to Figures 6 to 10, we can see that the energy recovery device 11 is shown there.

It should be noted that the upper part of the casing 12a of the body 12 has not been shown in Figure 6, and that the entire casing 12a of the body 12 has not been shown in Figures 7 to 10, so as to reveal the internal elements of the body 12.

In addition, the pendulums 13 have not been shown in Figures 7 to 10.

The energy recovery device 11 comprises first, second and third input shafts 14, 15 and 16 and an output shaft 17 which project from the body 12. The third input shaft 16 and the shaft output shafts 17 are aligned along a first diameter of the sphere forming the body 12, the first and second input shafts 14, 15 being aligned along a second diameter of the sphere forming the body 12, the four shafts 14, 15, 16 and 17 being in the same plane and the axis of the first and second input shafts 14, 15 being perpendicular to the axis of the third input shaft 16 and the output shaft 17.

Each of the shafts 14, 15, 16 and 17 is connected, at its proximal end inside the body 12, to a gear mechanism, generally referenced by the reference numeral 18, whose specific structure and connection specific with the shafts 14, 15, 16 and 17 will be described later, such that any rotational movement on any of the first, second and third input shafts 14, 15, 16 is converted, through the gear mechanism 18, into a unidirectional rotational movement on the output shaft 17.

Such unidirectional rotational movement on the output shaft 17 is used, with the aid of an alternator 19, to generate electricity from any rotational movement on the input shafts 14, 15 , 16.

A support 20 with a flange 21 at one end has bearings 20a (shown in Figure 10) which carry one end of the output shaft 17, the support 10 being fixed to the internal wall of the sealed housing 6 of preferably by screws inserted into through holes 21a formed in the flange 21. It should be noted that the alternator 19 is located inside the support 20.

Similarly, the third input shaft 16 has a flange 22 (not shown in Figure 6) formed integrally with the third input shaft 16 at one end, with a bearing 16a (shown in Figure 10) which carries the other of the ends of the output shaft 17, the flange 22 also being fixed to the internal wall of the sealed casing 6 preferably by screws inserted in through holes 22a formed in the flange 22.

On the distal part of each of the first and second input shafts 14, 15 is fixed a pendulum 13 which rotates the corresponding input shaft, respectively 14, 15. The pendulums 13 on each of the first and second input shafts entry 14, 15 are identical.

Each pendulum 13 comprises an arm 23 and a weight 24.

The arm 23 is long enough for the weight 24 to move around the body 12. The shape of the weight 24 is curved so that the weight 24 can move around the body 12, without coming into contact with the shafts 16, 17 or the support 20. The pendulums 13 can thus rotate around the body 12 at 360°.

The curved shape of the weight 24 makes it possible to have the maximum weight and to move freely around the body 12 of spherical shape.

The upper part of the arm 23 has two branches 23a, 23b separated by a slot 25 extending along the longitudinal direction of the arm 23. The bottom of the slot 25 has a cylindrical shape capable of receiving the free end of the corresponding input shaft 14, 15.

The free end of the corresponding input shaft 14, 15 is blocked by screws and bolts 26 inserted into through holes formed in the two branches 23a, 23b.

In use, each pendulum 13 is locked on the free end of the corresponding input shaft 14, 15 and its movement causes said input shaft 14, 15 to move.

The shape of the pendulums 13 and the spherical body 12 ensure maximum compactness of the energy recovery device 11, without the pendulums 13 interfering with the shape of the body 12.

The alternator 19 (shown in detail in Figure 10) comprises a coil 19a and at least one permanent magnet 19b. The at least one permanent magnet 19b of the alternator 19 is incorporated in the support 20 and the coil 19a is located in the output shaft 17, so that the coil 19a comes into rotation with the rotation of the shaft. output 17 relative to the at least one static permanent magnet 19b.

It should be noted that the alternator 19 could, as a variant, comprise a fixed coil located at the level of the support 20 and at least one permanent magnet located in the output shaft 17, without departing from the scope of the present invention.

The gear mechanism 18 will now be described in more detail.

The transmission between the third input shaft 16 and the output shaft 17 will first be described, then the transmission between the first and second input shafts 14, 15 and the output shaft 17 will be described. .

As indicated above, the output shaft 17 aligned with the third input shaft 16 is carried at one end in the support 20 by bearings 20a.

The third input shaft 16 extends in a tube 27 (shown in Figure 10) formed integrally with the third input shaft 16 which passes through a first gear wheel 28 and a second gear wheel. gear 29, each of the first and second gear wheels 28, 29 being connected to a one-way clutch, respectively 28a, 29a. The third input shaft 16, through the tube 27, engages the one-way clutch 28a in a first direction of rotation and with the one-way clutch 29a in a direction of rotation opposite to the first direction.

In the first direction of rotation, the third input shaft 16 engages the one-way clutch 28a, which in turn engages the output shaft 17, thereby driving the output shaft 17 in the same direction. direction of rotation than the third input shaft 16.

In the opposite direction of rotation of the third input shaft 16, the third input shaft 16 does not engage the output shaft 17 since the one-way clutch 28a does not engage the output shaft 17.

However, the third input shaft 16, through the tube 27, engages the gear wheel 29 through the one-way clutch 29a and thus drives the gear wheel 29 in the same direction of rotation.

Gear wheel 29 then meshes with gear wheel 30, which in turn meshes with gear wheel 31 on axle 32 on which gear wheel 33 and gear wheel 34 are arranged.

Gear wheels 33 and 34 mesh with axle 32.

When driven by shaft 32, gear wheel 33 meshes with gear wheel 35, meshing with output shaft 17 and driving output shaft 17.

Thus, whatever the direction of rotation of the third input shaft 16, the direction of rotation on the output shaft 17 is the same, namely unidirectional.

A rotational movement of the input shafts 14, 15, 16 will be caused by a movement of the sealed casing 6 which will be caused by an external movement coming from the moving fluid in which the sealed casing 6 is immersed.

The transmission from the first and second input shafts 14, 15 to the output shaft 17 will now be described.

The first input shaft 14 meshes with a gear wheel 36.

Gear wheel 36, when driven by rotation of first input shaft 14 in the correct direction of rotation, meshes with gear wheel 37.

The gear wheel 37 is meshed on a shaft 38 which carries two gear wheels 39 and 40, each being meshed with a shaft 38 through a one-way clutch, respectively 39a and 40a, so that that the gear wheel 39 engages the shaft 38 in one of its directions of rotation and that the gear wheel 40 engages the shaft 38 in its other direction of rotation.

When engaged with shaft 38, gear wheel 39 meshes with gear wheel 41 which in turn meshes with gear wheel 42. Gear wheel 42 engages taken with a shaft 43 and rotates the shaft 43 on which is fixed a helical wheel 44 which meshes with a helical wheel 45 on the output shaft 17 to drive the latter in a direction of rotation.

On the second input shaft 15, a gear wheel 46 engages the second input shaft 15. Similar to the first input shaft 14, when engaged with the second input shaft 15, gear wheel 46 engages a gear wheel (not shown but similar to gear wheel 37) meshing with shaft 38 and rotates gear wheel 40 which meshes with a gear wheel 47, meshing with the axle 43. Rotation of the gear wheel 47 rotates the worm wheel 44 to rotate the worm wheel 45 and thus the output shaft 17.

The one-way clutches are mounted such that if the distal ends of the first and second input shafts 14, 15 are rigidly connected, a direction of rotation of the first and second input shafts 14, 15 engages the transmission regarding one of the first and second input shafts 14, 15 while not engaging the transmission with respect to the other of the first and second input shafts 14, 15, and the opposite direction of rotation of the first and second input shafts input 14, 15 engages the transmission with respect to said other of the first and second input shafts 14, 15 while not engaging the other transmission.

Thus, when the pendulums 13 are for example rigidly connected, whatever the movement, there is always an input shaft 14, 15 which can transfer the energy of movement to the output shaft 17.

One-way clutches ensure that only one of the first and second input shafts 14, 15 transfers motion to the output shaft 17.

Moreover, the structure is such that, regardless of the movement on the first and second input shafts 14, 15, the helical wheels 44, 45 always have the same direction of rotation.

Although the invention is described with helical wheels, the invention is not limited thereto, and bevel wheels could be used to transfer the movement to the output shaft 17 instead of the helical wheels, without deviate from the scope of the present invention.

It should be noted that the transmission mechanism between the first, second and third input shafts 14, 15, 16 and the output shaft 17 could also take any other architecture comprising one or more elements among gear wheels toothed chains, toothed sprockets, belts and pulleys, without departing from the scope of the present invention.

As indicated above, the pendulums 13 can be rigidly connected, or can be independent. In any case, there will always be a unidirectional rotational movement on the output shaft 17.

In use, the body 12 is fixed inside the sealed box 6 by the flanges 21 and 22.

The body 12 is then free to rotate inside the sealed box 6 around its third input shaft 16.

It should be noted that the brackets and corresponding screws and bolts in body 12 which allow the gear wheels and shafts to be attached are not referenced so as not to overload the Figures with reference numerals.

When the waterproof case 6 is placed in the moving fluid (for example, in a marine environment), a movement is created on the pendulums 13, which generates a rotation on the output shaft 17, and the rotation of the body 12 around the third input shaft 16 also creates rotation on the output shaft 17 and thus energy through the alternator 19.

The energy recovery device 11 according to the invention can be of any size depending on the desired application.

An advantage of the energy recovery device 11 is that, when it is fixed inside the sealed casing 6 disposed in the moving fluid, the body 12 moves relative to the sealed casing 6, and the pendulums 13 move relative to the body 12, which generates a movement on the output shaft 17 converted into electrical energy by the alternator 19. This means that the energy recovery device 11 according to the invention can generate energy by itself, when its sealed case 6 is left in the unstable environment of the moving fluid. The energy recovery device 11 thus makes it possible to generate electrical energy by recovering the energy of movement of its sealed casing 6 in all possible directions in the moving fluid.

It should be noted that the body 12 and the waterproof case 6 could also have any other shape, as long as the pendulums 13 can pivot around the body 12. The pendulums 13 are designed in such a way that, whatever the position of the pendulum 13 with respect to the body 12, the weight 24 of the pendulum 13 does not come into contact with any of the shafts 14, 15, 16 and 17, to allow maximum pivoting movement of the pendulums 13 around the body 12, and thus maximum energy production.

The alternator 19 of the energy recovery device 11 makes it possible to convert the mechanical energy supplied by the output shaft 17 into electrical energy.

The energy recovery device 11 further comprises at least one electrical load (not shown in the Figures) connected to the alternator 19, each electrical load being configured to store or consume electrical energy produced by the alternator 19 .

The at least one electrical load may be at least one of at least one battery, one electrical power cut-off resistor, at least one sensor, one cathodic protection device configured to impose a current on a metallic element on or in the sealed case 6 in order to prevent cathodic erosion, and an external electrical connection to the outside.

When the electrical load is a battery, the latter makes it possible to store the electrical energy produced by the alternator 19.

Rectifier type power conversion means are preferably disposed between the alternator 19 and the electrical load to convert the alternating current power generated by the alternator 19 into direct current power which may, for example, be stored in one or more batteries.

When the electrical load is a sensor, the latter is powered by the electrical energy produced by the alternator 19 in order to allow its detection operation.

When the electrical load is a cathodic protection device, the latter is powered by the electrical energy produced by the alternator 19 in order to impose a current on a metallic element on or in the sealed casing 6 so as to fight against the cathodic erosion and soiling of said metal element, thereby extending the life of the equipment and reducing maintenance costs.

When the electrical load is an external electrical connection, the latter is preferably arranged on the outer surface of the waterproof casing 6 and electrically connected to the alternator 19 to allow the electricity generated by the energy recovery device 11 to be used externally.

When the electric load is a cut-off resistance of the electric power supply (from the Anglo-Saxon term “load dump resistance”), the latter makes it possible to disconnect a powered load such as a battery powered by the alternator 19.

One or more electrical loads (for example, one or more battery elements) can be located in at least one of the pendulums 13, and dynamic power transfer means are then arranged between the alternator 19 and said at least one pendulum 13.

The arrangement of at least part of the electric load in the pendulums 13 thus makes it possible to make the energy recovery device 11 compact. The dynamic power transfer means allow a transfer of electric current between the alternator 19 and the electrical load disposed in the pendulums 13, said dynamic power transfer means comprising, for example, slip rings.

For example, the weight 24 of each pendulum 13 may comprise several battery cells which are embedded in the pendulum weight 24 without modifying its shape or limiting its rotational movement. Furthermore, the mass of the battery cells is specifically chosen to ensure the functionality of the pendulum weight 24.

The battery cells are electrically connected to the alternator 19 through the output shaft 17 and the body 12 through the slip ring type dynamic power transfer means. Output shaft 17 and first and second input shafts 14, 15 are electrically connected to body 12 by a slip ring. The slip ring allows a regular rotation of the corresponding shaft both by providing an electrical contact to allow a flow of electric current in order to charge the battery elements when the device 11 produces useful energy and also in order to discharge the elements of battery when the device 11 produces negative useful energy.

Electronic regulation means can also be provided to regulate the flow of charge to or from the battery elements according to the power generated by the device 11 and the power demanded by the electric load or loads.

The energy recovery device 11 can also be used to dampen the vortex-induced vibrations undergone by the flexible link 7, such as an oil platform riser, on which is fixed the sealed box 6 containing the energy recovery device. energy 11. Indeed, these vortex-induced vibrations can lead to fatigue damage of vibrating structures, such as subsea risers that experience vortex-induced vibrations, which presents a significant problem for the construction industry. offshore oil.

In order to overcome this problem, the electrical load connected to the alternator 19 can be chosen so as to slow the rotational movement of the output shaft 17 in order to slow the rotational movement of the input shafts 14, 15, 16 , which makes it possible to reduce the amplitude of the vortex-induced vibrations undergone by the flexible connection 7 to which the sealed casing 6 is fixed.

The electric load, which has a chosen value which charges the alternator 19, slows the output shaft 17 and thus limits the movement of the pendulums 13, these pendulums 13 being initially excited by the vortex-induced vibrations, so that the The energy removed reduces the amplitude of movement of the sealed housing 6 and thus reduces the amplitude of vortex induced vibrations experienced by the flexible link 7.

The energy recovery device 11 is in this case used to generate an opposing force on the sealed casing 6 by applying a given electrical charge to the alternator 19. This electrical charge creates an opposing force with respect to to the direction of movement of the sealed casing 6, which makes it possible to reduce the movement of the sealed casing 6 and therefore of the flexible connection 7 at the level of the sealed casing 6. The level of movement damping can thus be modified by controlling the load electric connected to the alternator 19.

When used to dampen vortex-induced vibrations, the electrical load may be one of a pre-calculated fixed load, a pre-programmed variable load, and an active load externally controlled or on-board using a an inertial measurement unit.

The damping of vortex-induced vibrations can thus be passive (using the pre-calculated fixed load or the pre-programmed variable load) or active (using the active load).

The fixed load is calculated beforehand and the variable load is programmed beforehand so as to maximize the damping of vortex-induced vibrations in the moving fluid.

Likewise, the active load is controlled in real time so as to maximize the damping of vortex-induced vibrations in the moving fluid.

The active load is either controlled externally acoustically or by cable, or controlled on board using machine learning, an inertial measurement unit allowing real-time measurement of the position and acceleration of the waterproof housing 6 so as to control the active load accordingly.

The electric load allowing the damping of the vortex-induced vibrations can, for example, be one or more battery cells or a resistor for a cut-off of the electric power supply.

It should be noted that, when a pair of sealed boxes 6 is fixed on the flexible connection 7, the two sealed boxes 6 being arranged at the same height on the flexible connection 7 and on either side of the flexible connection 7 , this makes it possible to prevent an asymmetrical movement of the assembly at said height.

Claims (14)

– Energy recovery system (1; 8; 9) in a moving fluid, said system (1; 8; 9) comprising an anchoring means (4) at a fixed point with respect to the moving fluid, a flotation means (5) in the moving fluid and at least one flexible connection (7a, 7b; 7c, 7d, 7e, 7f; 7) connecting the flotation means (5) to the anchoring means (4), such that, when the energy recovery system (1; 8; 9) is installed in a moving fluid, the flotation means (5) floats in the moving fluid above the anchoring means (4 ), characterized in that said system (1; 8, 9) further comprises at least one sealed casing (6) fixed to the at least one flexible connection (7a, 7b; 7c, 7d, 7e, 7f; 7 ), each sealed casing (6) comprising, inside the latter, an energy recovery device (11) capable of recovering energy by movement of the associated sealed casing (6) in the moving fluid , said recovery device n of energy (11) comprising:
- a body (12) designed to move relative to the associated waterproof case (6);
- aligned first and second input shafts (14, 15) projecting from two opposite faces of the body (12);
- a first pendulum (13) mounted on the distal end of the first input shaft (14);
- a second pendulum (13) mounted on the distal end of the second input shaft (15);
- an output shaft (17) whose direction is perpendicular to the direction of the first and second input shafts (14, 15);
- a bearing (20a) fixed inside the associated sealed casing (6), in which the distal end of the output shaft (17) is freewheeling;
- a third input shaft (16) aligned with the output shaft (17), the direction of the third input shaft (16) being perpendicular to the direction of the first and second input shafts (14, 15) , a distal end of the third input shaft (16) being fixed inside the associated waterproof casing (6);
- mechanical connection means at the proximal end of each of the first, second and third input shafts (14, 15, 16) which are inside the body (12), said mechanical connection means operating with a transmission system arranged inside the body (12) such that any rotational movement on any of the first, second and third input shafts (14, 15, 16) is converted into a unidirectional rotational movement on the output shaft (17);
- an alternator (19) connected to the output shaft (17) and configured to convert the unidirectional rotational movement of the output shaft (17) into electrical energy; and
- at least one electrical load connected to the alternator (19), each electrical load being configured to store or consume electrical energy produced by the alternator (19). - Energy recovery system (1; 8; 9) in a moving fluid according to claim 1, characterized in that the at least one electric load is at least one of at least one battery, a resistance power cut-off device, at least one sensor, a cathodic protection device configured to impose a current on a metallic element on or in the at least one sealed housing (6) in order to prevent cathodic erosion, and a external electrical connection to the outside. - Energy recovery system (1; 8; 9) in a moving fluid according to claim 1 or 2, characterized in that all or part of the at least one electric charge is located in at least one pendulums (13), and dynamic power transfer means are arranged between the alternator (19) and said at least one pendulum (13). - Energy recovery system (1; 8; 9) in a moving fluid according to one of claims 1 to 3, characterized in that the mechanical connection means of the first, second and third input shafts ( 14, 15, 16) to the transmission system are one or more of toothed gears, toothed chains, toothed sprockets, belts and pulleys. - Energy recovery system (1; 8; 9) in a moving fluid according to one of claims 1 to 4, characterized in that the transmission system between the mechanical connection means of the first, second and third input shafts (14, 15, 16) and the output shaft (17) includes one or more of sprockets, toothed chains, sprockets, belts and pulleys. - Energy recovery system (1; 8; 9) in a moving fluid according to one of claims 1 to 5, characterized in that the anchoring means (4) is connected to the at least one flexible connection (7a, 7b; 7c, 7d, 7e, 7f; 7) by one of a rigid connection and an articulated connection, said anchoring means (4) being one of a mass laid at said point fixed and a mass fixed to said fixed point. - Energy recovery system (1; 8; 9) in a moving fluid according to one of claims 1 to 6, characterized in that the flotation means (5) is one of a float, a buoy, a floating platform or structure, an oil platform and a balloon. - Energy recovery system (1; 8; 9) in a moving fluid according to one of claims 1 to 7, characterized in that the at least one flexible connection (7a, 7b; 7c, 7d, 7e, 7f; 7) is at least one of at least one flexible pipe, at least one flexible cable, at least one flexible riser, at least one flexible drill string and at least one flexible umbilical cord. - Energy recovery system (1; 9) in a moving fluid according to one of claims 1 to 8, characterized in that said system (1; 9) comprises one of a single sealed box (6 ) fixed, preferably, at the center of the length of the flexible connection (7a, 7b; 7) and a single pair of sealed boxes (6) fixed, preferably, at the center of the length of the flexible connection (7a, 7b 7) on either side of the flexible connection (7a, 7b; 7). - Energy recovery system (8) in a moving fluid according to one of claims 1 to 8, characterized in that said system (8) comprises one of a plurality of sealed boxes (6) fixed, preferably, in a distributed manner on the flexible link (7c, 7d, 7e, 7f) and a plurality of pairs of sealed boxes (6) fixed, preferably, in a distributed manner on the flexible link (7c, 7d, 7e, 7f ), the two sealed casings (6) of a pair of sealed casings (6) being arranged on either side of the flexible connection (7c, 7d, 7e, 7f). - Energy recovery system (1; 8; 9) in a moving fluid according to one of claims 1 to 10, characterized in that the at least one sealed box (6) is configured to be put in movement by vortex-induced vibrations caused by the moving fluid. - Energy recovery system (1; 8; 9) in a moving fluid according to claim 11, characterized in that the at least one electric load connected to the alternator (19) is configured to slow down the movement rotation of the output shaft (17) so as to slow the rotational movement of the input shafts (14, 15, 16) to reduce the magnitude of vortex-induced vibrations experienced by the at least one housing waterproof (6). - Energy recovery system (1; 8; 9) in a moving fluid according to claim 12, characterized in that the at least one electrical load is one of a precalculated fixed load, a preprogrammed variable load , and an active load controlled externally or on board using an inertial measurement unit. – Use of an energy recovery system (1; 8; 9) in a moving fluid according to one of claims 1 to 13 in an underwater environment.