FR3029886A1 - FLOATING SUPPORT COMPRISING A COMPARTMENT FILLED WITH GAS AND LIQUID - Google Patents

Abstract

The object of the present invention is a floating support comprising a compartment (2) filled with gas and water, and communicating with the external environment. The compartment makes it possible to better adapt the buoyancy, and thus the stability, of the floating support with respect to the multiple constraints of the marine environment: wind, waves, sea currents, or the effects of the tide. The present invention also relates to a wind turbine system and a hydrocarbon production installation comprising such a floating support, as well as a method for installing such a floating support.

Description

The present invention relates to the field of floating supports moored offshore ("offshore"), in particular for offshore wind turbines, but also for offshore hydrocarbon production facilities.

In the case of offshore wind turbines, the floating support carries, partly emerged, the wind turbine consisting of blades, rotor, nacelle and mat fixed on the floating support. These floating supports can be anchored to the seabed by stretched anchor lines or catenary anchor lines. The floating support is intended to bring the buoyancy and stability of the wind turbine, so as to counteract the forces exerted on it.

The buoyancy, the stability and the dimensioning of the floating support are the main problems encountered for the floating supports, in particular because of the multiple constraints of the marine environment: wind, swell, marine currents, effects of the tide. For example, the patent applications FR 2990005 (WO 2013160579), FR 2990477 (WO 2013167820) and FR 2999662 (US 2014167421) propose various solutions to these problems, by modifying the anchoring, by connecting the floats to each other or by inclination of the float. In addition, in order to overcome these problems, other technical solutions envisaged concern floating platforms with controllable heave thanks to more or less optimized ballasts. However, the buoyancy control techniques can be improved, in particular by managing the volume of air in a bell formed in the immersed part of the floating support.

The object of the present invention is a floating support comprising a compartment filled with gas and water, and communicating with the external environment. The compartment makes it possible to better adapt the buoyancy, and thus the stability, of the floating support with respect to the multiple constraints of the marine environment: wind, waves, sea currents, or the effects of the tide. The device according to the invention The invention relates to a floating support comprising at least one compartment in communication with an external liquid medium such that, in use, said compartment comprises a gas in its upper part and a liquid in its part. lower, said liquid from the external medium in which there is said floating support 3029886 2. Said floating support comprises means for adjusting the volume and / or the gas pressure in said compartment. According to one embodiment of the invention, said compartment is central with respect to the floating support.

Alternatively, said compartment is at the periphery of said floating support. Advantageously, said compartment communicates with the external medium by means of an opening towards the external environment. According to an alternative embodiment of the invention, said opening is located in the lower part of said compartment.

According to an alternative, said compartment communicates with said external medium by means of a tube, having substantially the shape of an inverted U and being open at both ends thereof. According to one characteristic of the invention, said floating support comprises at least one floating chamber disposed above and / or at the center and / or at the periphery of said compartment. According to one aspect of the invention, said floating support comprises at least one ballast and / or at least one ballast. Preferably, said floating support comprises anchoring means, in particular in the form of tensioned anchor lines or catenary lines.

Advantageously, said gas is air and wherein said liquid is water. According to one embodiment of the invention, said means for adjusting the volume and / or the pressure of gas in said compartment comprise a gas compressor and a valve. Advantageously, said compressor is a vane compressor or a rotary nozzle compressor. In addition, the invention relates to a wind turbine system comprising at least one wind turbine and a floating support.

In addition, the invention relates to a hydrocarbon production facility comprising at least one petroleum equipment and a floating support. The invention also relates to a method of installing a floating support on a liquid extent, in which the following steps are performed: a) moving said floating support on said body of water; b) is fixed on the bottom of the liquid and said floating support at least one anchor line; and 3029886 3 c) a gas is injected into the compartment of said floating support to tension said anchor line. BRIEF DESCRIPTION OF THE DRAWINGS Other features and advantages of the method according to the invention will become apparent on reading the description hereafter of nonlimiting examples of embodiments, with reference to the appended figures and described below. FIG. 1 illustrates a wind turbine mounted on a floating support according to the invention. FIG. 2 illustrates the forces exerted on a floating support according to the invention.

FIG. 3 illustrates an alternative embodiment of the compartment of the floating support according to the invention. FIG. 4 illustrates another alternative embodiment of the compartment of the floating support according to the invention. Figures 5 and 6 illustrate alternative embodiments of the floating support according to the invention. FIG. 7 illustrates three stages of the installation, by means of tense anchor lines, of a floating support according to the embodiment of FIG. 1. FIG. 8 illustrates three stages of the installation, by means of tense anchor lines, a floating support according to the embodiment of Figure 5.

FIG. 9 illustrates three stages of placing, by means of catenary anchor lines, a floating support according to the embodiment of FIG. 5. FIG. 10 represents a vane compressor. Figure 11 shows a compressor with rotary spouts.

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a floating support which comprises a compartment communicating with the external liquid medium, so that, when using the floating support (that is to say when the floating support fleet), the compartment has in its upper part a gas, and in its lower part a liquid from the external medium. Within the compartment, the gas and the liquid are in pressure equilibrium at the gas / liquid interface. Preferably, the gas is air. In the remainder of the description, the invention will be described by choosing air as gas filling the chamber. However, any other gas that is compressible and inert with the liquid, for example a rare gas, can be used.

3029886 4 Generally, the liquid is water, corresponding to the external environment on which the floating support rests, that is to say an ocean, a sea, a river, a lake, a river, a swimming pool ... In the remainder of the description, the invention will be described by choosing water as a liquid from the external environment filling the chamber. However, the invention is compatible with other liquids. The compartment communicating with the external environment is an enclosure more or less immersed with its lower part in communication and in hydrostatic pressure equilibrium with the water of the external environment. When central, the compartment may have a substantially cylindrical or parallelepiped shape. The compartment can be considered a bell. The interior volume of the compartment is constant; all the variations of the volume of gas are compensated by inverse variations of the volume of water, since in communication with the external liquid medium. The compartment can be made of reinforced concrete. The air included in the compartment contributes to the buoyancy of the floating support. Buoyancy is the vertical thrust, directed upward (in the opposite direction to gravity), that a liquid (gas or fluid) exerts on a submerged volume. FIG. 2 describes the principle of a floating bell-shaped support 2 according to an exemplary embodiment of the compartment 2. The bell (compartment) 2, of "diver bell" type, may comprise a submerged part and an emergent part . The assembly can be retained by anchor lines. Air 4 is injected at the pressure P2 into the bell 2 to balance the different forces applied: the forces directed downwards: the gravitational force of the mass in the air of the emerged part of the bell and mounted equipment on the floating support, the gravitational force of the apparent mass of the immersed portion of the bell and, where appropriate, the tensile forces applied by the anchor lines. the force directed upwards: the buoyancy of Archimedes, due to the mass of the volume of water displaced by the volume of air injected under pressure into the bell. These different forces, as well as the geometric dimensions are illustrated in FIG. 2, with the following notations: Ho: total height of the bell support 2 for the immersed and emerged parts; H3: water level in the bell, depending on the pressure P2 of the air in the bell and forces applied; hl: height between the base of the bell and the surface of the water; 35 h2: height of the air between the water / air interface in the bell and the surface of the water; P2 air pressure in the bell, which is lower than the hydrostatic pressure of the water column of height hl; V2: volume of air in the bell, between the water / air interface in the bell and the surface of the water; V4: volume of air in the bell 2 between the bottom of the bell, that is to say the upper limit of the bell, and the surface of the water; 5 ps external air pressure, this pressure corresponds to the atmospheric pressure; Peo: gravitational force of the equipment installed on the floating support; T: traction on the anchor lines; Sae: surface of the air / water interface in the bell; Far: Archimedean thrust due to the mass of the displaced water volume, V2 is the volume 10 taken into account for the computation of the Archimedean thrust. The interior volume of the "bell" filled with air and water allows a balance of forces applied to the system. Thus, the force of the upwardly directed Archimedes thrust is equal to the sum of the downward forces which are the gravitational forces of the different masses of the emerged and submerged portions and, where appropriate, the pulling forces. applied by the anchor lines. The buoyancy of the support depends on the volume of air contained in the bell. According to the invention, this volume of air is adjusted by means for adjusting the pressure and / or the volume of the compressed air in the "bell". The compartment may have a constant cross section, for example substantially rectangular or circular. Alternatively, the compartment may have a variable section, the compartment may then have a substantially conical shape. In the first case, the volume V2 of water displaced by air injection is only proportional to the height of air in the compartment. Thus, the force due to buoyancy is only proportional to the air level in the compartment. For the alternative, the volume of water displaced no longer depends solely on the air level in the compartment. Thus, the force due to buoyancy does not depend solely on the air level in the compartment, but also depends on the geometry of the compartment. According to the invention, the floating support comprises means for adjusting the volume and / or the gas pressure in the compartment. The adjustment of the volume of gas in the compartment allows variable and adjustable buoyancy of the floating support. In addition, the volume of water inside the compartment is displaced by injection of compressed air into the compartment, the air pressure then being equal to the height of the hydrostatic water column, which is the height between the water / air interface in the compartment and the reference level of the sea outside the compartment. Thus, when air is injected into the compartment, the buoyancy increases and the floating support rises relative to the bottom of the water body. When air is withdrawn into the compartment, the buoyancy decreases and the floating support lowers relative to the bottom of the body of water. The floating support according to the invention may furthermore comprise the following means, alone or in combination: at least one flotation chamber, which may be a sealed and sealed chamber comprising air. The flotation chamber constitutes a reserve of buoyancy complementary to the floating support. The flotation chamber can also be a safety device to prevent the floating support from sinking in the event of leakage of the compressed air contained in the compartment. The float chamber may be disposed above and / or at the center and / or peripherally of the compartment. at least one ballast to increase the weight of the floating support and thus improve its stability. Preferably, the ballast may be attached to the lower part of the floating support, in particular to the lower part of the compartment and, where appropriate, to the lower part of the floating chamber. at least one ballast to stabilize the floating support. Preferably, the ballast may be attached to the lower part of the floating support, in particular to the lower part of the compartment and, where appropriate, to the lower part of the floating chamber. Anchoring means to the seabed, which may be in particular tensile anchor lines or catenary. The anchoring means also contribute to the stability of the floating support. The floating support according to the invention can allow an offshore installation of a device for operating wind power (horizontal or vertical axis), a device for exploiting marine energies (waves, waves, tides, thermal energy of the seas ...), a petroleum equipment ... In the following description and drawings, and in a nonlimiting manner, only the application to a horizontal axis wind turbine is presented. This application to a horizontal axis wind turbine is particularly suitable for the floating support 30 according to the invention, in terms of effort (wind, waves ...), weight and dimensions. However, the other applications are also adapted to the various embodiments of the floating support described. Depending on the application, the floating support may have an emergent part and a submerged part. Alternatively, the floating support can be completely submerged. In the same way, the compartment can be completely immersed or have an emergent part.

Figures 1, 3 and 4 illustrate three non-limiting embodiments of the compartment according to the invention. According to a first variant embodiment, the communication of water between the compartment and the external medium is carried out in the lower part of the compartment, said compartment being completely open in its lower part. FIG. 1 illustrates an exemplary embodiment of this first variant applied to an installation of an offshore wind turbine. For this exemplary embodiment, a wind turbine 6 is installed on the floating support 1. The floating support 1 comprises a compartment 2 10 comprising air 4 and water 3. The air is in the upper part of the compartment 2 and the water is in the lower part of the compartment 2. The compartment 2 is completely open in its lower part. The means for adjusting the volume of gas in the compartment 2 are situated in the upper part of the compartment 2. According to this example, the compartment 2 has substantially the shape of a vertical cylinder, the cylinder not comprising a wall from its lower base. Optionally, the floating support 1 comprises a ballast 5 fixed to the lower part of the compartment. The ballast 5 may be in the form of a crown. Alternatively, the ballast 5 may consist of a plurality of elements. According to a second variant embodiment, the communication of water between the compartment and the external medium is carried out in the lower part of the compartment, said compartment comprising at least one reduced opening in its lower part, that is to say that the opening represents a part, and not all, of the lower part of the compartment. FIG. 3 illustrates an exemplary embodiment of this second variant. In this figure, only the compartment 2 is shown, the other optional components (ballast, ballast, anchor, floatation chamber) of the floating support and the equipment installed on the floating support are not illustrated. The compartment 2 comprises air 4 and water 3. The compartment 2 comprises means 7 for adjusting the volume of air 4 in the compartment 2. The compartment 2 also comprises an opening 8 located in the lower wall of the 30 compartment. The opening 8 corresponds only to a portion of the lower wall of the compartment. According to this example and without limitation, the compartment 2 has substantially a shape of a vertical cylinder, the lower base of the cylinder has an opening 8 for the passage of water. As shown, the opening 8 is central, but it can also be arranged off-center.

According to a third variant embodiment, the communication of water between the compartment and the external medium is carried out by means of a tube having substantially the shape of an inverted U. The tube is open at both ends. One branch of the U of the tube is immersed in the external environment and the other branch of the U is immersed in the liquid contained in the compartment. Apart from the U-tube, the compartment is closed. The two branches of the U-tube may have substantially the same length. The U-shaped tube allows the water to flow freely between the interior of the compartment and the outside environment and thus to balance the pressure at the interface of the air-water fluids contained in the compartment. The bottom of the compartment is in equipression with the external environment by the branches of the U-tube. The principle of the "bell", explained by means of FIG. 2, is preserved, and this configuration makes it possible to install equipment (pump, dices, valves) at the surface, in the upper part of the tube. FIG. 4 illustrates an exemplary embodiment of this third variant. In this figure, only the compartment 2 is shown, the other optional components (ballast, ballast, anchoring, floating chamber) and the equipment installed on the floating support are not illustrated. The compartment 2 comprises air 4 and water 3. The compartment 2 comprises means 7 for adjusting the volume of air 4 within the compartment. The compartment 2 further comprises an inverted U-shaped tube 9, the branches of which respectively plunge into the external environment and into the water contained in the compartment 2. The compartment 2 is closed; it comprises only an opening for the passage of the tube 9, and has no direct opening with the external environment. According to this example and without limitation, the compartment 2 has substantially a shape of a vertical cylinder. The upper base of the cylinder has a passage for the tube 9. Other variants of the communication means between the liquid medium and the compartment can be envisaged, for example by means of a lateral opening of the compartment. According to one aspect of the invention, the floating support may further comprise a flotation chamber which may be a sealed and sealed chamber comprising air. The flotation chamber constitutes a reserve of buoyancy complementary to the floating support. The flotation chamber can also be a security, to prevent the floating support flowing in the event of leakage of compressed air contained in the compartment. The flotation chamber may be disposed above and / or at the center and / or at the periphery with respect to the compartment. The flotation chamber can be combined with the different embodiments of the compartment.

According to one characteristic of the invention, the compartment may be located in the center of the floating support. The compartment can then have a substantially cylindrical shape.

Alternatively, the compartment may be located at the periphery of the floating support. The compartment can then have substantially a crown shape. In addition, the floating support may comprise a plurality of compartments. In this case, each compartment may have substantially a cylinder portion shape or crown portion. In addition, in case of a plurality of compartments, the means for adjusting the volume of air within the compartments can be controlled simultaneously or separately, so as to adjust the buoyancy on either side of the floating support. . FIG. 5 illustrates an example of a floating support on which an offshore wind turbine is installed. According to this example, a wind turbine 6 is installed on a floating support 1. The support 1 comprises a compartment 2 comprising air 4 and water. The means for adjusting the volume of air in the compartment are not shown. The compartment 2 is made according to the first embodiment, illustrated for example in Figure 1. The floating support 1 further comprises a flotation chamber 10, filled with air. As shown, the buoyancy chamber is located above the compartment 2, the compartment 2 and the buoyancy chamber 10 having substantially a cylindrical shape and being central with the floating support 1. The floating support 1 further comprises, and optionally, a ballast 5 fixed to the lower part of the compartment 2.

Figure 6 illustrates an example of a floating support applied to an offshore wind facility. According to this example, a wind turbine 6 is installed on a floating support 1. The floating support 1 comprises a plurality of compartments 2 situated at the periphery of a flotation chamber 10. The flotation chamber 10 is central with respect to the floating support 1. The compartments 2 are made according to the first embodiment variant, illustrated for example in FIG. 1. The compartments 2 may have substantially forms of crown portions. In this figure, the means for adjusting the volume of air 4 within each compartment are not shown. Optionally, the floating support 1 comprises a ballast 5 fixed to the lower part of the floating chamber 10.

Other non-illustrated configurations of the flotation chamber are conceivable, with one or more flotation chambers, with an arrangement at the periphery of one or more flotation chambers ... The adjustment of the volume of air in the compartment allows to adjust the buoyancy of the floating support. This adjustment of the buoyancy can facilitate the installation of the floating support by means of anchor lines, by setting controlled traction of the anchor lines.

Figures 7, 8 and 9 illustrate three steps of installing a floating support equipped with a wind turbine for different configurations of the floating support. The three phases illustrated are from left to right: the transport phase, the laying of the anchor lines, and the controlled pulling of the anchor lines.

FIG. 7 shows these three steps, for a floating support comprising a compartment, a ballast 5 and anchor lines 11 of the type anchored tension lines. During the transport phase, the anchor lines are not installed and the compartment has air 4 so as to ensure the buoyancy of the floating support equipped with the wind turbine 6. Once in its final position, it carries out the laying anchor lines 11 and their attachment 10 on the bottom of the body of water (seabed) and on the floating support. Once secured, the anchor lines 11 are tensioned by raising the floating support. The floating support is raised by air injection 4 into the compartment, which increases the buoyancy of the floating support. FIG. 8 shows these three steps for a floating support comprising a compartment, a float chamber 10, a ballast 5 and anchor lines 11 of the tensioned anchor line type (embodiment of FIG. 5). During the transport phase, the anchor lines are not installed and the compartment does not have air 4. The buoyancy of the floating support equipped with the wind turbine 6 is carried out during this phase by the flotation chamber. Once in its final position, the anchoring lines 11 are placed and fixed on the bottom of the body of water (seabed) and on the floating support. Once secured, the anchor lines 11 are tensioned by raising the floating support. The floating support is raised by air injection 4 into the compartment, which increases the buoyancy of the floating support. FIG. 9 shows these three steps, for a floating support comprising a compartment, a flotation chamber 10, a ballast 5 and anchor lines 11 of the catenary anchor line type (embodiment of FIG. 5). During the transport phase, the anchor lines are not installed and the compartment does not have air 4. The buoyancy of the floating support equipped with the wind turbine 6 is carried out during this phase by the flotation chamber. Once in its final position, the anchoring lines 11 are placed and fixed on the bottom of the body of water (seabed) and on the floating support. Once secured, the anchor lines 11 are tensioned by raising the floating support. The floating support is raised by air injection 4 into the compartment, which increases the buoyancy of the floating support. These three steps can be similarly repeated for all the configurations described: for the different variants of the compartment, with a different arrangement of the floating chamber ...

The means for adjusting the volume of air inject air from the ambient air into the upper part of the compartment. The means for adjusting the volume of air withdrawn air from the upper part of the compartment to the ambient air. The means for adjusting the volume of air in the compartment may include a compressor and / or a depressant and a valve. The compressor can be a vane compressor. An example of a vane compressor 13 is shown in FIG. 10. The direct drive vane compressor operates at low speed, about 1450 rpm. The rotor has a number of slots along its length which accommodate sliding vanes 14 which slide on a film of oil. The rotor rotates in a cylindrical stator. When rotating, the centrifugal force pulls the pallets out of their place: they then form individual compression cells. The rotation reduces the volume of the cell and thus increases the air pressure. Alternatively, the compressor may be a compressor-depressor rotating nozzles. FIG. 11 illustrates an exemplary rotating nose compressor compressor 15. The rotary nozzle compressor comprises two rotors 16 driven synchronously in opposite directions. The rotors 16 have protrusions in the form of beaks which compress the air.

Claims (15)

CLAIMS1) Floating support comprising at least one compartment (2) in communication with an external liquid medium such that, in use, said compartment comprises a gas (4) in its upper part and a liquid (3) in its part lower, said liquid (3) coming from the external medium in which said floating support (1) is located, characterized in that said floating support (1) comprises means (7) for adjusting the volume and / or the gas pressure ( 4) in said compartment (2). 2) floating support according to claim 1, wherein said compartment (2) is central with respect to the floating support (1). 3) floating support according to one of the preceding claims, wherein said compartment (2) is at the periphery of said floating support (1). 4) Floating support according to one of the preceding claims, wherein said compartment (2) communicates with the external medium by means of an opening to the outside environment. 5) floating support according to claim 4, wherein said opening is located in the lower part of said compartment (2). 6) floating support according to one of claims 1 to 3, wherein said compartment (2) communicates with said external medium by means of a tube (9) having substantially the shape of an inverted U and being open to its two ends. 7) Floating support according to one of the preceding claims, wherein said floating support (1) comprises at least one flotation chamber (10) disposed above and / or at the center and / or periphery of said compartment (2). 8) Floating support according to one of the preceding claims, wherein said floating support (1) comprises at least one ballast (5) and / or at least one ballast. 9) Floating support according to one of the preceding claims, wherein said floating support (1) comprises anchoring means, in particular in the form of tensioned anchor lines (11) or catenary (12). 3029886 13 10) floating support according to one of the preceding claims, wherein said gas (4) is air and wherein said liquid (3) is water. 11) Floating support according to one of the preceding claims, wherein said means (7) for adjusting the volume and / or gas pressure in said compartment comprises a gas compressor and a valve. 12) Floating support according to claim 11, wherein said compressor is a vane compressor (13) or a rotary nozzle compressor (15). 10 13) Wind turbine system comprising at least one wind turbine (6) and a floating support (1) according to one of the preceding claims. 14) A hydrocarbon production facility comprising at least one petroleum equipment 15 and a floating support (1) according to one of claims 1 to 12. 15) A method of installation on a liquid extent of a floating support according to one of claims 1 to 11, wherein the following steps are performed: a) moving said floating support on said body of water; (B) at least one anchor line (11) is fixed to the bottom of the liquid expanse and said floating support; and c) injecting a gas into the compartment (2) of said floating support to tension said anchor line (11). 25