Watertight and thermally insulating tank wall

Abstract

The invention relates to a wall (11) comprising a thermally insulating barrier (12, 14) and a metallic sealing membrane (13, 15) resting against the thermally insulating barrier; the thermally insulating barrier comprising at least one load-bearing element (20), the load-bearing element comprising: - a hollow pillar (21) made of composite material that rises along the thickness direction (E) of the wall, - a sleeve (25) made of composite material fitted onto the hollow pillar and bonded against a longitudinal surface of the pillar; and - an internal plate (22) that is metallic, fixed to the sleeve via a fastening device and against which the sealing membrane is welded, wherein the sleeve has an internal end that is flush with an internal end of the pillar and wherein the internal plate bears, directly or indirectly, partly against the internal end of the pillar and partly against the internal end of the sleeve. Figure for the abstract: 1

Description

Title of the invention: Wall for a watertight and thermally insulating tank technical field

[0001] The invention relates to the field of walls for sealed and thermally insulating tanks. In particular, the invention relates to the field of walls for sealed and thermally insulating tanks for the storage and / or transport of a liquefied gas, such as liquid hydrogen, which is at approximately -253°C at atmospheric pressure. Technological background

[0002] In the prior art, sealed and thermally insulated tanks for storing a liquefied gas are known.

[0003] Such a tank generally comprises a plurality of walls, each comprising a multilayer structure, including at least one thermally insulating barrier retained to a load-bearing structure and a sealing membrane resting against a thermally insulating barrier and intended to be in contact with the liquefied gas contained in the tank.

[0004] One of the main difficulties is that in a tank of the aforementioned type, the wall sealing membrane is not subjected to uniform stress because the membrane deforms, in particular, under the effect of thermal and mechanical stresses generated by the liquefied gas stored in the tank. Such heterogeneous stresses can quickly damage the tank. Summary of the invention

[0005] To allow for better stress distribution within the waterproofing membrane, the inventors conceived of a thermally insulating barrier comprising discrete support structures, each supporting a zone of the waterproofing membrane, to which the waterproofing membrane is welded. The discrete support structures include, for example, composite material pillars that rise along the thickness direction of the wall to support the waterproofing membrane. Each pillar is fitted and bonded to stainless steel sleeves at opposite ends of the pillar. The sleeves extend beyond the pillar opening, thus forming a metallic extension beyond the pillar, with which the pillar is in contact.

[0006] Such an arrangement has several drawbacks. The combination of a composite material pillar and a stainless steel sleeve implies a significant risk of damage to the pillar and the sleeve during large temperature variations. temperature, for example during the loading and unloading of liquefied gas in the tank. Indeed, the coefficients of thermal expansion of the composite material and the stainless steel sleeve are very different, resulting in unwanted movement of the pillar relative to the sleeve. Consequently, thick adhesive joints, i.e., greater than 2 mm, are applied between the pillar and the sleeve to compensate for these differences in thermodynamic behavior.

[0007] However, such a solution is not satisfactory because the thicker the glue joint, the more difficult it is to accurately determine its resistance to compression and shear forces.

[0008] There is therefore a need to find an alternative in order to solve the aforementioned problems.

[0009] One idea underlying the invention is therefore to solve the aforementioned problems.

[0010] Another idea underlying the invention is to provide a wall for a tank watertight and thermally insulating in which the mechanical stresses exerted on the sleeve are reduced, particularly at the junction between the pillar and the sleeve.

[0011] Another idea underlying the invention is to propose a wall for a sealed and thermally insulating tank allowing the attachment of a metal plate on which the sealing membrane is fixed to a pillar made of composite material.

[0012] Another idea underlying the invention is to eliminate areas of weakness at the junction of the pillar with the sleeve.

[0013] According to one embodiment, the invention provides a wall for a sealed and thermally insulating tank for storing a liquefied gas, the wall comprising, along a wall thickness direction, a thermally insulating barrier and a metallic sealing membrane which rests against the thermally insulating barrier; the thermally insulating barrier comprising at least one load-bearing element, the load-bearing element comprising: - a hollow pillar made of composite material that rises along the thickness direction of the wall, - a composite material sleeve fitted onto the hollow pillar and bonded against a longitudinal surface of the pillar; and - an internal plate which is metallic, fixed to the sleeve via a fastening device and against which the sealing membrane is welded, in which the sleeve has an internal end which is flush with an internal end of the pillar and in which the internal plate is supported, directly or indirectly, partly against the internal end of the pillar and partly against the internal end of the sleeve.

[0014] Thanks to these characteristics, the thermomechanical stresses exerted on the connection of the sleeve with the pillar are reduced.

[0015] Indeed, since the sleeve and the pillar are both made of composite material, the differential expansion of one with respect to the other is lower than if the sleeve were made of stainless steel, which makes it possible to limit the stresses in the glue layer when the tank is cooled and therefore to reduce the thickness of the glue layer.

[0016] Furthermore, when compressive forces are exerted along the thickness direction of the wall on the inner plate, a portion of these forces is absorbed by the supporting pillar without passing through the sleeve and the adhesive layer. The adhesive layer that secures the sleeve to the pillar is subjected to little or no shear stress. Thus, the risk of the sleeve detaching is significantly reduced.

[0017] By convention, the terms "external" and "internal" are used to define the relative position of one element with respect to another, by reference to the inside and outside of a tank having such a wall. In particular, the internal end of the sleeve means the end of the sleeve that will be closest to the inside of a tank having such a wall, and the external end of the sleeve means the end of the sleeve that will be farthest from the inside of the tank. Similarly to the sleeve, the internal end of the pillar means the end of the pillar that will be closest to the inside of a tank having such a wall, and the external end of the pillar means the end of the pillar that will be farthest from the inside of the tank.

[0018] According to embodiments, such a wall may include one or more of the following characteristics.

[0019] According to one embodiment, the inner plate is supported partly against the inner end of the pillar and partly against the inner end of the sleeve by means of a support plate which is interposed between the inner plate and the inner end of the pillar, the support plate having an inner surface in contact with the inner plate and an outer surface in contact with the inner end of the pillar and the inner end of the sleeve.

[0020] According to one embodiment, the sleeve has a coefficient of thermal expansion oq along a radial direction perpendicular to the wall thickness direction that is within the range [0.75 x a2; 1.25 x a2], where a2 is the coefficient of thermal expansion of the pillar along the radial direction. This means that the coefficient of thermal expansion of the sleeve, along the radial direction, lies within a range extending from 25% below the coefficient of thermal expansion along the radial direction of the pillar to 25% above the coefficient of thermal expansion along the radial direction of the pillar.

[0021] Thanks to these characteristics, the relative displacement of the sleeve with respect to the pillar in response to temperature variations is reduced. Consequently, the thermomechanical stresses applied to the adhesive are also mitigated.

[0022] According to one embodiment, the coefficient of thermal expansion oq along a radial direction perpendicular to the thickness direction of the sleeve wall is included in the interval [0.85 x a2 ; 1.15 x a2].

[0023] According to a preferred embodiment, the coefficient of thermal expansion of the sleeve and the pillar are identical, along the radial direction.

[0024] According to one embodiment, the support plate has a coefficient of thermal expansion a3 in the radial direction which is within the interval [0.75 x ai; 1.25 x aj; and in the interval [0.75 x a2 ; 1.25 x a2]. In other words, the coefficient of thermal expansion aj of the sleeve, a2 of the pillar or a3 of the bearing plate, depending on the radial direction, lies in a range of values ​​which extends from 25% below to 25% above the coefficients of thermal expansion of the other elements.

[0025] Thanks to these characteristics, the relative displacements of the sleeve, the pillar, and the support plate in response to temperature variations are reduced. Consequently, the thermomechanical stresses applied to the adhesive layer are also attenuated, which helps to maintain the sleeve in its initial position.

[0026] According to one embodiment, the sleeve has a generally cylindrical shape and includes a cylindrical recess. Preferably, the sleeve has a generally cylindrical shape of revolution. The sleeve may have different shapes to facilitate bonding the sleeve to the longitudinal surface of the pillar and to reduce the thickness of the adhesive layer required for bonding the sleeve to the pillar.

[0027] According to one embodiment, the cylindrical recess of the sleeve has the shape of a cylinder with a circular or elliptical cross-section.

[0028] According to one embodiment, the sleeve is formed by a plurality of distinct sections distributed around a longitudinal axis of the pillar, the plurality of distinct sections being fixed on the longitudinal surface of the pillar.

[0029] Thanks to these features, the sleeve is more adaptable and easier to install against the longitudinal surface of the pillar. Furthermore, this arrangement reduces the thickness of the adhesive layer required to fix the sleeve to the pillar.

[0030] In one embodiment, the sections of the plurality of sections have an identical shape. In another embodiment, the sections of the plurality of sections have a different shape.

[0031] According to one embodiment, the sections of the plurality of sections each have an internal end that is flush with the internal end of the pillar.

[0032] According to one embodiment, the plurality of distinct sections comprises a first section and a second section, the first section and the second section being diametrically opposed on either side of the longitudinal axis of the pillar. According In one embodiment, the first section and the second section each have the shape of a half-tube or a crescent.

[0033] According to one embodiment, the plurality of distinct sections comprises a first section, a second section, and a third section. According to a preferred embodiment, the first, second, and third sections each have a general crescent shape.

[0034] According to one embodiment, each section of the plurality of sections is separated by a gap. Thus, variations in the sleeve's dimensions during its manufacture do not prevent the sleeve from being installed in the pillar, since these variations result in a difference in dimensions that is less than the size of the gap.

[0035] According to one embodiment, the cylindrical recess has a dimension sufficient to allow the passage of a tool enabling the plurality of distinct sections of the sleeve to be pressed radially outwards against the longitudinal surface of the pillar.

[0036] According to one embodiment, the sleeve is formed in one piece.

[0037] According to one embodiment, the sleeve and the longitudinal surface of the pillar are bonded by a layer of glue having a thickness in a radial direction perpendicular to the thickness direction of less than 1 mm. According to a preferred embodiment, the glue layer has a thickness greater than 0 mm and less than 0.5 mm, preferably a thickness less than 0.2 mm and even more preferably a thickness less than 0.1 mm.

[0038] Thus, a thinner layer of adhesive reduces the risk of unwanted air entrapment between the surfaces. Furthermore, a thinner layer of adhesive can cure more quickly, resulting in faster manufacturing of the carrier element.

[0039] According to one embodiment, the layer of glue located between the sleeve and the longitudinal surface of the pillar is pressed via a pressing tool.

[0040] Thanks to these characteristics, the pressed adhesive layer exhibits greater resistance to shear stresses. Indeed, pressing notably increases the contact surface area between the adhesive layer and the pillar.

[0041] According to one embodiment, the diameter of the support plate is greater than or equal to the diameter of the pillar.

[0042] According to one embodiment, the support plate is an aluminum washer.

[0043] Aluminium is advantageous in that it exhibits greater compressive strength than a composite material while having a coefficient of thermal expansion closer to that of the composite material of the pillar than other metals, particularly when the composite material of the pillar is a unidirectional glass-epoxy composite.

[0044] According to one embodiment, the fastening device comprises an outer plate positioned against an outer end of the sleeve and a tie rod connecting the inner tray to the outer plate such that the sleeve is gripped between the inner tray and the outer plate. In other words, the fastening device secures the inner tray to the outer plate by clamping the sleeve between the inner tray and the outer plate.

[0045] Thanks to these features, the sleeve is held firmly in position between the outer plate and the inner plate.

[0046] According to one embodiment, the outer plate is an aluminum washer.

[0047] According to one embodiment, the outer plate has an outer diameter smaller than the inner diameter of the pillar.

[0048] According to one embodiment, the sleeve is fitted inside the pillar.

[0049] According to one embodiment, the sleeve is fitted to the outside of the pillar.

[0050] According to one embodiment, the sleeve extends along a longitudinal direction of the tube, from the inner end of the pillar, over a distance of between 5 and 10 cm.

[0051] According to one embodiment, the load-bearing element comprises a first sleeve fitted inside the pillar and a second sleeve fitted outside the pillar.

[0052] According to one embodiment, the hollow pillar has an internal diameter of between 4 and 10 cm.

[0053] In one embodiment, the interior of the hollow pillar comprises an insulating material. In one embodiment, the insulating material is located between the first and second sleeves. In another embodiment, the insulating material fills the interior space of the pillar located between the first and second sleeves. In one embodiment, the insulating material is an insulating foam. In one embodiment, the insulating foam is in the shape of an elongated cylinder.

[0054] According to one embodiment, the fastening device comprises a threaded rod and an element having a female thread.

[0055] According to one embodiment, the fastening device comprises a screw and nut system.

[0056] According to one embodiment, the fastening device comprises a threaded rod which traverses, along the longitudinal thickness direction, the inner plate, the sleeve and the outer plate, the fastening device further comprising a first nut screwed from a first end of the threaded rod and a second nut fixed on a second end of the threaded rod in order to clamp the sleeve between the outer plate and the inner plate.

[0057] According to one embodiment, the threaded rod of the fastening device also passes through the metal support plate, the sleeve being sandwiched between the outer plate and the metal support plate.

[0058] According to one embodiment, the fastening device comprises a plurality of threaded rods, each threaded rod being fixed via their inner end to the inner plate and screwed via their outer end into a tapped hole provided in the outer plate.

[0059] Thanks to these features, it is possible to control the compressive force exerted against the sleeve. Indeed, the more the threaded rod is screwed into the tapped hole, the closer the outer plate is to the inner plate, which has the effect of clamping the sleeve.

[0060] According to one embodiment, each threaded rod includes at least one spring washer mounted on said threaded rod, the spring washer preferably being a Belleville washer.

[0061] Thus, it is possible to control the compressive force exerted against the sleeve.

[0062] According to one embodiment, the composite material of the pillar comprises fibers and a matrix, which makes it possible to obtain satisfactory compressive strength for a limited conductive section.

[0063] According to one embodiment, the fibers are selected from glass fibers, carbon fibers, aramid fibers, flax fibers, basalt fibers and mixtures thereof.

[0064] According to one embodiment, the matrix is ​​chosen from polyethylene, polypropylene, poly(ethylene terephthalate), polyamide, polyoxymethylene, poly-lyetherimide, polyacrylate, polyaryletherketone, polyetheretherketone, copolymers thereof, polyester, vinyl ester, epoxy and polyurethane.

[0065] According to a preferred embodiment, the pillars are made of an epoxy resin reinforced with glass fibers.

[0066] According to one embodiment, the composite material of the sleeve comprises fibers and a matrix.

[0067] According to one embodiment, the fibers are selected from glass fibers, carbon fibers, aramid fibers, flax fibers, basalt fibers and mixtures thereof.

[0068] According to one embodiment, the matrix is ​​chosen from polyethylene, polypropylene, poly(ethylene terephthalate), polyamide, polyoxymethylene, poly-lyetherimide, polyacrylate, polyaryletherketone, polyetheretherketone, copolymers thereof, polyester, vinyl ester, epoxy and polyurethane.

[0069] According to a preferred embodiment, the pillars are made of an epoxy resin reinforced with glass fibers.

[0070] According to a preferred embodiment, the composite material of the sleeve and the pillar are identical.

[0071] According to one embodiment, the internal tray is made of stainless steel.

[0072] According to one embodiment, the internal tray has a thickness between between 4 and 10 mm.

[0073] According to one embodiment, the adhesive used to bond the sleeve to the pillar is chosen from: polyethylene, polypropylene, poly(ethylene terephthalate), polyamide, polyoxymethylene, polyetherimide, polyacrylate, polyaryl-therketone, polyetheretherketone, copolymers thereof, polyester, vinyl ester, epoxy and polyurethane.

[0074] According to one embodiment, the wall comprises successively, along a wall thickness direction, a secondary thermally insulating barrier intended to rest against a load-bearing structure, a secondary metallic sealing membrane which rests against the secondary thermally insulating barrier, a primary thermally insulating barrier which rests against the secondary sealing membrane and a primary sealing membrane which rests against the primary thermally insulating barrier and is intended to be in contact with the liquefied gas contained in the tank.

[0075] According to one embodiment, the secondary thermally insulating barrier comprises at least one of the aforementioned load-bearing elements.

[0076] According to one embodiment, the secondary thermally insulating barrier comprises a plurality of the aforementioned load-bearing elements.

[0077] According to one embodiment, the primary thermally insulating barrier comprises at least one of the aforementioned load-bearing elements.

[0078] According to one embodiment, the primary thermally insulating barrier comprises a plurality of the aforementioned load-bearing elements.

[0079] In one embodiment, the secondary thermally insulating barrier and the primary thermally insulating barrier each comprise at least one of the aforementioned load-bearing elements. In another embodiment, the primary thermally insulating barrier and the secondary thermally insulating barrier comprise a plurality of the aforementioned load-bearing elements.

[0080] According to one embodiment, the primary sealing membrane comprises a first series of corrugations having first corrugations parallel to each other and a second series of corrugations having second corrugations parallel to each other and perpendicular to the first corrugations, the primary sealing membrane comprises a plurality of flat zones which are each defined between two adjacent first corrugations and between two adjacent second corrugations, the plurality of flat zones of the primary sealing membrane comprising a first flat zone which is respectively welded against the internal plate of the load-bearing element.

[0081] According to one embodiment, the load-bearing element comprises: - an external plate which is metallic, against which the secondary sealing membrane is welded, - an external sleeve made of composite material fitted onto the hollow pillar and bonded against a longitudinal surface of the pillar, the external plate being fixed to the external sleeve via an external fixing device, the external sleeve having an external end which is flush with an external end of the pillar, and the external plate being supported, directly or indirectly, partly against the external end of the pillar and partly against the external end of the external sleeve, the primary sealing membrane being welded against the internal tray.

[0082] The external sleeve has, according to embodiments, characteristics analogous to the sleeve. For example, according to one embodiment, the external sleeve is formed by a plurality of distinct sections distributed around a longitudinal axis of the pillar, the plurality of distinct sections being fixed on the longitudinal surface of the pillar.

[0083] According to one embodiment, the secondary sealing membrane comprises a first series of corrugations having first corrugations parallel to each other and a second series of corrugations having second corrugations parallel to each other and perpendicular to the first corrugations, the secondary sealing membrane comprising a plurality of flat zones which are each defined between two adjacent first corrugations and between two adjacent second corrugations, the plurality of flat zones of the secondary sealing membrane comprising a first flat zone which is respectively welded against the internal plate of the carrier element.

[0084] According to one embodiment, the primary thermally insulating barrier has a gaseous phase under vacuum, preferably at an absolute pressure less than 1 Pa.

[0085] According to one embodiment, the secondary thermally insulating barrier has a gaseous phase under vacuum, preferably at an absolute pressure less than 1 Pa.

[0086] In one embodiment, the liquefied gas is liquid hydrogen.

[0087] According to one embodiment, the invention also provides a sealed and thermally insulating tank comprising a plurality of the aforementioned walls.

[0088] Such a tank may be part of an onshore storage facility or be installed in a floating structure, whether coastal or deep water, in particular a ship for transporting liquid hydrogen, i.e., a hydrogen tanker, a floating storage and regasification unit (FSRU), a floating production and remote storage unit (FPSO), and others. Such a tank can also serve as a fuel tank in any type of vessel.

[0089] According to one embodiment, a ship for the transport of a liquefied gas comprises a double hull and the aforementioned tank disposed in the double hull.

[0090] According to one embodiment, the invention also provides a transfer system for a liquefied gas, the system comprising the aforementioned vessel and insulated pipelines arranged to connect the tank installed in the hull of the vessel to a floating or land-based storage facility.

[0091] According to one embodiment, the transfer system also includes a pump for driving a flow of liquefied gas through insulated pipes from or to the floating or land-based storage facility to or from the ship's tank.

[0092] According to one embodiment, the invention also provides a method for loading or unloading such a vessel, in which a liquefied gas is conveyed through insulated pipelines from or to a floating or land-based storage facility to or from the vessel's tank. Brief description of the figures

[0093] The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent from the following description of several particular embodiments of the invention, given solely by way of illustration and not limitation, with reference to the accompanying drawings.

[0094] Fig. 1 represents a partial perspective view of a wall of a sealed and thermally insulating tank according to one embodiment.

[0095] Fig. 2 represents a partial, schematic cross-sectional view of a load-bearing element according to a first embodiment.

[0096] Fig. 3 represents a partial perspective view of a load-bearing element according to a second embodiment.

[0097] Fig. 4 represents a partial, cross-sectional view of a load-bearing element according to the second embodiment.

[0098] Fig. 5 represents a partial, top view of the sleeve of the load-bearing element according to the second embodiment, during a step of gluing the sleeve inside the pillar.

[0099] Figure [Fig. 6] represents a partial perspective view of a load-bearing element according to a third embodiment.

[0100] Fig. 7 represents a partial perspective view of a load-bearing element according to a fourth embodiment.

[0101] Fig. 8 represents a partial cross-sectional view of a load-bearing element according to a fifth embodiment.

[0102] Fig. 9 is a schematic, cutaway perspective view of a structure load-bearing structure intended to support a sealed and thermally insulated tank for storing a liquefied gas.

[0103] The [Fig. 10] is a schematic cutaway representation of a ship's tank and a terminal for loading and unloading this tank. Description of the implementation methods

[0104] In relation to [Fig. 1], a wall 11 intended to be integrated into a sealed and thermally insulating tank is described below in general terms according to an embodiment.

[0105] The wall 11 has a multilayer structure comprising, along the thickness direction of the wall 11, from the outside to the inside, a secondary thermally insulating barrier 12, a secondary sealing membrane 13 which is corrugated and fixed against the secondary thermally insulating barrier 12, a primary thermally insulating barrier 14 and a primary sealing membrane 15 which is corrugated and fixed against the primary thermally insulating barrier 14. The primary sealing membrane 15 is intended to be in contact with the liquefied gas, such as liquid hydrogen contained in the tank.

[0106] The secondary thermally insulating barrier 12 comprises a plurality of insulating panels 16 anchored to a supporting structure 1. Each of the insulating panels 16 comprises a layer of insulating polymer foam 17 sandwiched between an inner plate 18 and an outer plate 19. The inner plate 18 and outer plate 19 are, for example, plywood panels glued onto said layer of insulating polymer foam 17. The insulating polymer foam may, in particular, be a polyurethane-based foam preferably reinforced with fibers.

[0107] The primary thermally insulating barrier 14 comprises a plurality of load-bearing elements 20 extending along the thickness direction E of the wall 11, between the secondary waterproofing membrane 13 and the primary waterproofing membrane 15. Each of the load-bearing elements 20 comprises a hollow, cylindrical pillar 21. Each pillar 21 is fixed at its inner end to an inner plate 22 and at its outer end to an outer plate 23.

[0108] The primary sealing membrane 15 is welded, at each flat area located between two pairs of corrugations, against a respective internal plate 22.

[0109] Similarly, the secondary sealing membrane 13 is welded, at each flat area located between two pairs of corrugations, against a respective external plate 23.

[0110] The pillar 21 is made from a composite material comprising fibers and a matrix. The inner plate 22 and the outer plate 23 are metallic, for example made of stainless steel.

[0111] Furthermore, the gaseous phase of the primary thermally insulating barrier 14 is advantageously placed under vacuum, for example at an absolute pressure below 1 Pa and preferably below 10² Pa. To achieve this, the primary thermally insulating barrier 14 is advantageously connected to a vacuum pump. Thanks to the gaseous phase being placed under vacuum, the thermal insulation properties of the primary thermally insulating barrier 14 are increased. However, the vacuum conditions of the primary thermally insulating barrier 14 will tend to deform the primary sealing membrane 15 and the secondary sealing membrane 13 inwards towards the primary thermally insulating barrier 15.

[0112] The arrangement of the plurality of load-bearing elements 20 makes it possible to support the primary sealing membrane 15 by taking on the one hand the forces due to the hydrostatic and dynamic pressures exerted on the primary sealing membrane 15 by the liquefied gas contained inside the tank, and on the other hand the forces due to the aforementioned vacuum conditions.

[0113] In relation to figures 2 to 8, a plurality of embodiments of the load-bearing element are described below.

[0114] Identical or similar elements bear the same reference numbers incremented by 100.

[0115] In relation to [Fig.2], a first embodiment of the load-bearing element is described below.

[0116] The load-bearing element 120 comprises a sleeve 125 made from a composite material. The sleeve 125 is positioned inside the pillar 121 and is bonded to an inner longitudinal surface 123 of the pillar 121, at the inner end of the pillar 121, such that the inner end of the sleeve 125 is flush with the inner end of the pillar 121. In other words, the sleeve 125 does not protrude beyond the inner end of the pillar. The thickness of the adhesive layer between the sleeve 125 and the inner longitudinal surface 123 is less than 0.2 mm.

[0117] The inner plate 122 has an external surface 126 in contact with the inner end of the pillar and with the inner end of the sleeve. Thus, a portion of the compressive forces exerted on the sealing membrane along the thickness direction E of the wall, for example due to the sloshing of the liquefied gas in the tank, are transmitted through the pillar on which the inner plate 122 rests without passing through the adhesive layer and the sleeve. The arrangement of the sleeve 125 flush with the pillar 121 therefore allows the adhesive layer to avoid, or to significantly limit, shear stresses.

[0118] Advantageously, the sleeve 125 and the pillar 121 are made from the same composite material. Consequently, they have the same coefficient of thermal expansion in a radial direction perpendicular to the wall thickness direction. Thus, the relative movement of the sleeve 125 with respect to the pillar 121 in response to temperature variations is zero or virtually zero. Therefore, the adhesive layer between the sleeve 125 and the pillar 121 is subjected to little or no stress and thus exhibits excellent adhesive properties. As a result, the attachment of the sleeve 125 to the pillar 121 is durable and stable.

[0119] In relation to figures 3 to 5, a second embodiment of the load-bearing element is described below.

[0120] The supporting element 220 has a sleeve 225 flush with the inner end of the pillar 221 in a manner similar to the first embodiment illustrated with [Fig.2].

[0121] The load-bearing element 220 further comprises a metal bearing plate 230 in the shape of a washer which, in the embodiment shown, has an outer diameter identical to the outer diameter of the pillar 221. The metal bearing plate 230 is preferably made of aluminum in order to have a coefficient of thermal expansion close to that of the composite material pillar 221. The metal bearing plate 230 has an inner surface 231 which is welded to the inner plate 222 and an outer surface 232 which is in contact with the inner end of the pillar 221 and the inner end of the sleeve 225.

[0122] The sleeve 225 comprises a first section 227 and a second section 228. The first section 225 and the second section 227 are made from a composite material.

[0123] The first section 227 is glued against the inner longitudinal surface 223 of the pillar 221.

[0124] The second section 228 is glued against the inner longitudinal surface 223, diametrically opposite the first section 227. A gap 285 is provided between the first section 227 and the second section 228.

[0125] The first section 227 and the second section 228 each have a shape resembling a crescent.

[0126] The sleeve 225, thus positioned in the pillar 221, has the general shape of a cylinder of revolution cut in half and with a cylindrical recess of elliptical cross-section 286 in its center. The cylindrical recess of elliptical cross-section 286 allows, for example, the passage of a pressing tool 82 intended to press the first section 227 and the second section 228 against the inner longitudinal surface 223 of the pillar 221 in order to firmly adhere them to said inner longitudinal surface 223.

[0127] The outer plate 233 is preferably made of aluminum. The outer plate 233 of the load-bearing element 220 is located against the outer end of the first section 227 and the second section 228 of the sleeve 225. The outer plate 233 has a smaller diameter than the metal support plate 230 in order to be positioned inside the pillar 221.

[0128] The outer plate 233 is fixed to the inner plate 222 via a tie rod 240 which passes through the sleeve 225 so that said sleeve 225 is sandwiched between the outer plate 233 and the inner plate 222. Thus, the outer plate 233 is fixed to the sleeve 225.

[0129] In the illustrated embodiment, the tie rod 240 comprises a threaded rod 241 that passes through the inner plate 222, the metal support plate 230, the cylindrical recess with elliptical cross-section 286, and the outer plate 233. The tie rod 240 further comprises a first nut 242 through which the threaded rod passes and which is located against the inner surface of the metal inner plate 222, and a second nut 243 through which the threaded rod passes and which is located against the outer surface 234 of the outer plate 233. Tightening the first nut 242 and / or the second nut 243 makes it possible to fix the outer plate 233 to the sleeve 225.

[0130] A sleeve 225 being installed is shown in particular with [Fig.5] in which the pressing tool 82 includes a pressing element 83 of the sleeve 225 and a retaining element 84 of the pillar 221. The pressing element 83 has an elliptical shape.

[0131] In order to correctly position and fix the sleeve 225, the pressing element 83 is inserted into the cylindrical recess with elliptical cross-section 286 and then a rotation as represented by the arrow on the pressing element 83 is then exerted so that said pressing element 83 presses the first section 227 and the second section 228 against the inner longitudinal surface 223. During this pressing step, the retaining element 84 surrounds the pillar 221 in order to take up the forces exerted radially by the pressing element 83.

[0132] Thanks to such a pressing tool 82, the sleeve 225 is correctly installed without damaging the structure of the pillar 221 and the layer of glue located between the pillar 221 and the sleeve 225 is pressed, which gives the layer of glue better resistance to shear.

[0133] In relation to [Fig.6], a third embodiment of the load-bearing element is described below.

[0134] The carrier element 320 differs from the carrier element 220 shown in Figures 3 to 5 in that the sleeve 325 has three sections, namely a first section 327, a second section 328 and a third section 329. In this embodiment, the three sections have the same shape and dimensions.

[0135] The first, second and third sections are glued inside the pillar 321 against the inner longitudinal surface 323 of the pillar 321 and each has a shape resembling a crescent. The first, second and third sections are separated from each other by gaps 385. The sleeve 325 forms in the center of the pillar a cylindrical recess 386 which has a generally circular cross-section.

[0136] According to alternative embodiments, the different sections of the sleeve may have differences, for example different shapes or dimensions.

[0137] In relation to [Fig.7], a fourth embodiment of the load-bearing element is described below.

[0138] The supporting element 420 differs from the supporting element 220 shown in Figures 3 to 5 in that the sleeve 425 is formed in one piece and has a general cylindrical shape with a circular cross-section that is concentric with the circular pillar 421. A gap of less than 1 mm is located between the sleeve 425 and the pillar 421. This gap forms an injection zone 441 which is intended to receive adhesive in order to form the adhesive layer that bonds the sleeve 425 to the pillar 421. The thickness of the adhesive layer located in the injection zone 441 is less than 1 mm.

[0139] The sleeve further has a cylindrical recess 486 which has a general shape of a cylinder with a circular cross-section. Alternatively, several shapes of cylindrical recess are conceivable.

[0140] In relation to [Fig.8], a fourth embodiment of the load-bearing element is described below.

[0141] The carrier element 520 differs from the carrier element 220 shown in Figures 3 to 5 in that the sleeve 525 is fitted outside the pillar 521. Thus, the sleeve 525 is fixed by bonding against an external longitudinal surface 550 of the pillar 521 and surrounds the pillar 521.

[0142] The outer plate 533 surrounds the pillar 521 and is fixed to the inner metal plate 522 via tie rods 540 located outside the pillar 521, so that the inner metal plate 522 rests against the inner end of the pillar 521 and the inner end of the sleeve 525. The outer plate 533 has tapped holes 543 for receiving the tie rods 540.

[0143] The tie rod 540 includes, for example, a screw 542. Each screw has a shank 541 which is threaded at its external end and which is fixed in one of the tapped holes in the external plate 533. This method of fixing allows, by rotating the first screw and the second screw in the tapped holes 543, the external plate 533 to be tightened against the internal end of the sleeve 525 in order to clamp the sleeve between the internal metal plate 522 and the external plate 533.

[0144] According to alternative embodiments not shown, the load-bearing element comprises a first sleeve fixed against an external longitudinal surface of the pillar as indicated previously in combination with a second sleeve fixed against an internal longitudinal surface of the pillar as previously indicated.

[0145] The aforementioned wall 11, comprising one or more of the aforementioned load-bearing elements, is intended to be integrated into a sealed and thermally insulated tank for storing a liquefied gas. The liquefied gas intended to be stored in the tank may, in particular, be liquid hydrogen, which has the characteristic of being stored at approximately -253°C at atmospheric pressure.

[0146] Such a tank is fixed against a supporting structure 1 as illustrated in [Fig.9],

[0147] The load-bearing structure 1 may, in particular, be formed of self-supporting metal sheets or, more generally, of any type of rigid bulkhead having suitable mechanical properties. The load-bearing structure 1 is, for example, formed by the double hull of a ship. In [Fig. 9], the load-bearing structure 1 has a generally polyhedral shape. It has two forward and aft load-bearing walls 2, here octagonal in shape, of which only the aft load-bearing wall 2 is shown. The forward and aft walls 2 are, for example, cofferdam walls of a ship that extend transversely to the longitudinal direction of the ship. The load-bearing structure 1 also includes an upper load-bearing wall 3, a lower load-bearing wall 4, and lateral load-bearing walls 5, 6, 7, 8, 9, 10.

[0148] With reference to [Fig. 10], a cutaway view of a vessel 70 shows a sealed and thermally insulating tank 71 of generally prismatic shape mounted in the double hull 72 of the vessel. The wall of the tank 71 comprises a primary sealing membrane intended to be in contact with the liquefied gas, preferably liquid hydrogen, contained in the tank, a secondary sealing membrane arranged between the primary sealing membrane and the double hull 72 of the vessel, and two thermally insulating barriers arranged respectively between the primary sealing membrane and the secondary sealing membrane and between the secondary sealing membrane and the double hull 72.

[0149] In a manner known per se, loading / unloading pipelines 73 arranged on the upper deck of the ship can be connected, by means of suitable connectors, to a marine or port terminal to transfer a cargo of liquefied gas from or to the tank 71.

[0150] Figure 10 also shows an example of a marine terminal comprising a loading and unloading berth 75, a subsea pipeline 76, and an onshore facility 77. The loading and unloading berth 75 is a fixed offshore facility comprising a movable arm 74 and a tower 78 that supports the movable arm 74. The movable arm 74 carries a bundle of insulated flexible pipes 79 that can be connected to the loading / unloading pipelines 73. The movable arm 74 The swiveling platform adapts to all hydrogenerator sizes. A connecting pipeline (not shown) extends inside the tower 78. The loading and unloading station 75 allows the hydrogenerator 70 to be loaded and unloaded from or to the onshore facility 77. This facility includes liquefied gas storage tanks 80 and connecting pipelines 81 linked by the subsea pipeline 76 to the loading or unloading station 75. The subsea pipeline 76 allows the transfer of liquefied gas between the loading or unloading station 75 and the onshore facility 77 over a long distance, for example 5 km, which makes it possible to keep the hydrogenerator 70 a considerable distance from the coast during loading and unloading operations.

[0151] To generate the pressure necessary for the transfer of the liquefied gas, one can either use pumps on board the ship 70 and / or pumps equipping the land installation 77 and / or pumps equipping the loading and unloading station 75 or allow a rise in pressure in the internal space of the tank under the effect of the evaporation of the liquefied gas stored in the tank.

[0152] Although the invention has been described in connection with several particular embodiments, it is clearly evident that it is by no means limited to them and that it includes all technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

[0153] The use of the verb "comporter", "comprendre" and its conjugated forms does not exclude the presence of other elements or other steps than those stated in a claim.

[0154] In the claims, any reference sign in parentheses shall not be interpreted as a limitation of the claim.

Claims

Demands

1. Wall for a sealed and thermally insulating tank for storing a liquefied gas, the wall (11) comprising, along a wall thickness direction, a thermally insulating barrier (12, 14) and a metallic sealing membrane (13, 15) which rests against the thermally insulating barrier; the thermally insulating barrier comprising at least one load-bearing element (20, 120, 220, 320, 420, 520), the load-bearing element comprising: - a hollow pillar (21, 121, 221, 321, 421, 521) made of composite material which rises along the thickness direction (E) of the wall, - a sleeve (25, 125, 225, 325, 425, 525) made of composite material fitted onto the hollow pillar (21, 121, 221, 321, 421, 521) and bonded against a longitudinal surface of the pillar;and - an internal plate (22, 122, 222, 522) which is metallic, fixed to the sleeve (25, 125, 225, 325, 425, 525) via a fixing device (240, 540) and against which the sealing membrane is welded, in which the sleeve has an internal end which is flush with an internal end of the pillar and in which the internal plate (22, 122, 222, 522) is supported, directly or indirectly, partly against the internal end of the pillar and partly against the internal end of the sleeve.;

2. Wall according to claim 1, wherein the inner plate (22, 122, 222, 522) is supported partly against the inner end of the pillar and partly against the inner end of the sleeve by means of a support plate (230) which is interposed between the inner plate and the inner end of the pillar, the support plate having an inner surface (231) in contact with the inner plate and an outer surface (232) in contact with the inner end of the pillar and the inner end of the sleeve.

3. Wall according to claim 1 or 2, wherein the sleeve has a coefficient of thermal expansion oq along a radial direction perpendicular to the thickness direction of the wall which is included in the interval [0.75 x a2 ; 1.25 x a2], with a2 a coefficient of thermal expansion of the pillar along the radial direction.

4. Wall according to claims 2 and 3 taken in combination, wherein the support plate has a coefficient of expansion thermal a3 along the radial direction which is included in the interval [0.75 x oq ; 1.25 x aj ; and in the interval [0.75 x a2 ; 1.25 x a2].

5. Wall according to any one of claims 1 to 4, wherein the sleeve has a general cylindrical shape and includes a cylindrical recess (286, 386, 486).

6. Wall according to any one of claims 1 to 5, wherein the sleeve is formed by a plurality of distinct sections distributed around a longitudinal axis of the pillar, the plurality of distinct sections being fixed on the longitudinal surface of the pillar.

7. Wall according to claim 6, wherein the plurality of distinct sections comprises a first section (227) and a second section (228), the first section and the second section being diametrically opposed on either side of the longitudinal axis of the pillar.

8. Wall according to claim 6, wherein the plurality of distinct sections comprises a first section (327), a second section (328) and a third section (329).

9. Wall according to any one of claims 1 to 5, wherein the sleeve is formed in one piece.

10. Wall according to any one of claims 1 to 9, wherein the sleeve and the longitudinal surface of the pillar are bonded by a layer of glue having a thickness along a radial direction perpendicular to the thickness direction which is less than 1 mm.

11. Wall according to any one of claims 1 to 10, wherein the fastening device comprises an outer plate positioned against an outer end of the sleeve and a tie rod connecting the inner plate to the outer plate so that the sleeve is gripped between the inner plate and the outer plate.

12. Wall according to any one of claims 1 to 11, wherein the sleeve is fitted inside the pillar.

13. Wall according to any one of claims 1 to 12, wherein the sleeve is fitted outside the pillar.

14. A sealed and thermally insulating tank comprising a plurality of walls according to any one of claims 1 to 13.

15. Vessel (70) for the transport of a liquefied gas, the vessel comprising a double hull (72) and a tank (71) according to claim 14 disposed in the double hull.

16. A transfer system for a liquefied gas, the system comprising a vessel (70) according to claim 15 and insulated pipes (73, 79, 76, 81) arranged to connect the tank (71) installed in the hull of the vessel to a floating or land-based storage facility (77).

17. A method of loading or unloading a ship (70) according to claim 15, wherein a liquefied gas is conveyed through insulated pipelines (73, 79, 76, 81) from or to a floating or land-based storage facility (77) to or from the tank (71) of the ship (70).

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