Wall for a sealed and thermally insulating tank for storing a liquefied gas

Abstract

The invention relates to a wall (10) for a sealed and thermally insulating tank for storing a liquefied gas, comprising a primary thermally insulating barrier (14) with a plurality of bearing elements (30) and a radiative multilayer insulation blanket (47), said blanket being attached to one of the bearing elements by an attachment device (51) comprising a connection portion attached to said bearing element and a support portion, in which the connection portion comprises two portions that are movable relative to one another between a spaced-apart position in which the two portions are spaced apart from one another in order to allow the bearing element to be passed through the attachment device and a close-together position in which the two portions are closer to each other compared to the spaced-apart position, so that the attachment device can be immobilized on the bearing element.

Description

Wall for a sealed and thermally insulating tank for storing liquefied gas

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

[0002] These tanks can be installed on land or on a floating structure. In the case of a floating structure, the tank may be intended to transport liquefied gas or to receive liquefied gas used as fuel for the propulsion of the floating structure. In the case of a land-based tank or a port storage structure, it may rest on the ground or the seabed and may be partially or completely buried. Technological background

[0003] Document FR3134571 discloses sealed and thermally insulating tanks for storing liquefied gas, such as liquid hydrogen.

[0004] This document discloses a wall for such a tank, comprising successively, in a thickness direction, a secondary thermally insulating barrier which rests against a supporting structure, a secondary 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.

[0005] The primary waterproofing 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 waterproofing membrane thus comprises a plurality of flat areas which are each defined between two adjacent first corrugations and between two adjacent second corrugations.

[0006] The primary thermally insulating barrier further comprises a plurality of load-bearing elements which are fixed to the secondary thermally insulating barrier and which rise in the thickness direction.

[0007] Each supporting element is fixed to an internal plate against which a flat area of ​​the primary waterproofing membrane is welded in support.

[0008] The primary thermally insulating barrier further comprises a radiative multi-layer insulation blanket which has openings through which the load-bearing elements pass and which extends orthogonally to the thickness direction of the wall.

[0009] In this type of tank wall, fixing the multi-layer insulation cover to the load-bearing elements is a delicate operation.

[0010] The idea behind the invention is to simplify the fastening of the multi-layer insulation cover to the load-bearing elements and to enable it to be fixed reliably and quickly at a predefined height of the load-bearing element.

[0011] According to one embodiment, the invention provides a wall for a sealed and thermally insulating tank for storing a liquefied gas, the wall comprising successively, in a thickness direction, a secondary thermally insulating barrier which rests against a supporting structure, a secondary 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; the primary thermally insulating barrier comprising a plurality of supporting elements which are fixed to the secondary thermally insulating barrier and which rise in the thickness direction, and a radiative multilayer insulation cover,which has openings through which the load-bearing elements pass and which extends transversely to the thickness direction of the wall, said multi-layer insulation cover being fixed to one of the load-bearing elements by a fixing device comprising a connecting part fixed to said load-bearing element and a support part extending transversely to the thickness direction of the wall, said insulation cover being fixed to said support part,in which the connecting part of the fixing device comprises two portions movable relative to each other between a separation position in which the two portions are spaced apart from each other to allow the carrier element to be placed through the fixing device so that the fixing device surrounds the carrier element and a bringing together position in which the two portions are brought together relative to the separation position, so as to be able to immobilize the fixing device on the carrier element by clamping the carrier element.,

[0012] Thanks to these features, it is possible to fix a fixing device at a precise height on the supporting element, and then, in a second step, fix the multi-layer insulation blanket on the fixing device. This makes fixing the multi-layer insulation blanket easier.

[0013] According to one embodiment, the fixing device is immobilized on the carrier element by gluing the fixing device to the carrier element and / or by elastic clamping of the carrier element and / or by axial locking of the fixing element which rests on at least one stop element of the carrier element extending projecting from the carrier element.

[0014] According to one embodiment, said carrier element has a central part of tubular shape and the two portions of the connecting part of the fixing device form in their approach position a collar whose internal dimensions are equal, to within a clearance, to the external dimensions of the central part of the carrier element.

[0015] According to one embodiment, the connecting part and the support part of the fixing device are made of one or more metal plates.

[0016] According to one embodiment, the two portions of the connecting part are connected by at least one jumper.

[0017] According to one embodiment, the two portions of the connecting part are connected by at least one hinge.

[0018] According to one embodiment, the two portions of the connecting part belong to a metal spring wire or to a metal spring blade.

[0019] According to one embodiment, said spring wire or said spring blade forms a single turn or a plurality of turns around the carrier element.

[0020] According to one embodiment, the connecting part of the fixing device elastically grips the supporting element.

[0021] According to one embodiment, the connecting part of the fixing device is glued to the supporting element.

[0022] According to one embodiment, the connecting part of the fixing device rests on at least one stop element of the carrier element extending projecting from a central part of the carrier element.

[0023] According to one embodiment, the connecting part of the fixing device is formed by a spring wire which has ends folded and nested one inside the other so as to be able to move elastically away from one another.

[0024] According to one embodiment, the support portion of the fixing device comprises at least one tab extending projecting from the connecting portion.

[0025] According to one embodiment, the tab is formed or is attached to said connecting part of the fixing device.

[0026] According to one embodiment, the two portions of the connecting part belong to a metal spring wire and the tab is formed by a fold of the wire or the spring blade.

[0027] According to one embodiment, the tab is formed by folding a metal plate forming one of the two portions of the connecting part.

[0028] According to one embodiment, the tab is formed by welding a metal plate onto one of the two portions of the connecting part.

[0029] According to one embodiment, the support portion of the fixing device comprises a fixing element of the multi-layer insulation cover adapted to cooperate with a complementary fixing element of the fixing device.

[0030] According to one embodiment, the fixing element of the multi-layer insulation cover is an orifice, the complementary fixing element of the fixing device comprises a fir-tree clip, a pin or a rivet and the multi-layer insulation cover comprises an opening located opposite this through orifice of the fixing element which is crossed by the fir-tree clip, the pin or the rivet.

[0031] According to one embodiment, the radiative multi-layer insulation blanket comprises a stack of a plurality of sheets made of metal or of a polymer material coated with a metal and separated from each other by a textile layer.

[0032] According to one embodiment, each pillar is made from a composite material comprising fibers and a matrix.

[0033] According to one embodiment, the primary thermally insulating barrier comprises insulating elements having an open-cell porous structure which are arranged between the radiative multi-layer insulation blanket and the secondary sealing membrane.

[0034] According to one embodiment, the primary thermally insulating barrier comprises a gas phase at an absolute pressure of less than 1 Pa.

[0035] According to one embodiment, the insulating elements are chosen from glass wool, rock wool, polyester wadding and open-cell polymer foams.

[0036] The invention also provides a sealed and thermally insulating tank integrated into a supporting structure, the supporting structure comprising a plurality of supporting walls, the tank comprising a plurality of tank walls each fixed to a respective supporting wall, including a tank wall as described above.

[0037] The invention also provides a vessel for transporting a fluid, the vessel comprising a double hull and a tank as described above, arranged in the double hull.

[0038] The invention also provides a transfer system for a liquefied gas, the system comprising a vessel as described above and insulated pipes arranged to connect the tank installed in the hull of the vessel to a floating or land-based storage facility.

[0039] The invention also provides a method of loading or unloading a ship as described above, in which a liquefied gas is conveyed through insulated pipes from or to a floating or land-based storage facility to or from the ship's tank. Brief description of the figures

[0040] The invention will be better understood, and other objects, details, characteristics and advantages thereof will appear more clearly during the following description of several particular embodiments of the invention, given solely for illustrative and non-limiting purposes, with reference to the accompanying drawings.

[0041] It represents a schematic view of a tank wall in section according to the wall thickness.

[0042] The figure represents a schematic perspective view of a first embodiment of the device for fixing the wall of the, on a supporting element.

[0043] The figure represents a schematic flat view of a portion of the fixing device of the.

[0044] The figure represents a schematic perspective view of a second embodiment of the device for fixing the wall of the, on a supporting element.

[0045] The figure represents a schematic rear perspective view of a third embodiment of the wall fixing device.

[0046] The figure represents a schematic perspective view of a fourth embodiment of the wall fixing device.

[0047] The figure represents a schematic top view of the wall fixing device.

[0048] The figure represents a schematic perspective view of a fifth embodiment of the wall fixing device.

[0049] The figure represents a schematic front view of the fifth embodiment of the wall fixing device.

[0050] This is a schematic cutaway representation of a hydrogen vessel tank and a loading / unloading terminal for this tank.

[0051] By convention, the terms "external" and "internal" are used to define the relative position of one element to another, with reference to the inside and outside of the tank. Identical or corresponding elements shown in these figures will be referenced by identical signs and will not be described each time.

[0052] The liquefied gas intended to be stored in the tank may in particular be liquid hydrogen, which has the particularity of being stored at approximately -253°C at atmospheric pressure.

[0053] The attached figures show different embodiments of a sealed and thermally insulating tank wall.

[0054] This sealed and thermally insulating tank is intended for the storage of liquefied gas and is intended to be fixed to a supporting structure 1 ().

[0055] The supporting structure 1 may in particular be formed of self-supporting metal sheets or, more generally, of any type of rigid partition having appropriate mechanical properties. The supporting structure is, for example, formed by the double hull of a ship.

[0056] The supporting structure 1 comprises a plurality of supporting walls and has a generally polyhedral shape.

[0057] La represents a wall 10 of a sealed and thermally insulating tank according to a first embodiment. The wall 10 has a multilayer structure. It comprises successively, in a thickness direction D of the wall 10, from the outside to the inside, a secondary thermally insulating barrier 12, a secondary sealing membrane 13, a primary thermally insulating barrier 14 and a primary sealing membrane 15 intended to be in contact with the liquefied gas contained in the tank. The tank walls are fixed each time to a load-bearing wall of the plurality of load-bearing walls.

[0058] The secondary thermally insulating barrier 12 rests against the supporting structure 1. It comprises a plurality of insulating panels 16 anchored to the supporting structure 1. The insulating panels 16 each comprise a layer of insulating polymer foam 17 sandwiched between an inner plate 18 and an outer plate 19. The inner 18 and outer 19 plates are, for example, plywood plates glued to said layer of insulating polymer foam 17. According to a variant, the inner 18 and outer 19 plates are made from a polymer matrix reinforced by fibers, such as glass fibers. The insulating polymer foam may in particular be a polyurethane-based foam. The polymer foam is advantageously reinforced by fibers, such as glass fibers, helping to reduce its thermal contraction.

[0059] The insulating panels 16 are anchored to the supporting structure 1 by means of secondary anchoring devices, not shown. Each insulating panel 16 is, for example, fixed at at least each of its four corners.

[0060] According to one embodiment, the external plate 19 of the insulating panels 16 protrudes relative to the layer of insulating polymer foam 17, at least at the corners of the insulating panel 16, so as to form the support zones of the insulating panels 16 cooperating with the support members of the secondary anchoring devices.

[0061] Portions of mastic 20 are interposed between the external plate 19 of the insulating panels 16 and the supporting structure 1. The portions of mastic 20 thus contribute to compensating for the surface irregularities of the supporting structure 1. According to an advantageous variant embodiment, the portions of mastic 20 adhere to the external plate 19 of the insulating panels 16 and to the supporting structure 1. The portions of mastic 20 thus participate in anchoring the insulating panels 16 on the supporting structure 1. In such an alternative embodiment, the secondary anchoring devices are optional.

[0062] The insulating panels 16 have substantially the shape of a rectangular parallelepiped and are juxtaposed in parallel rows and separated from each other by gaps ensuring functional assembly clearance. The gaps are filled with a heat-insulating filling, not shown, such as glass wool, rock wool or flexible open-cell polymer foam, for example. The gaps may also be filled with insulating plugs, as described in applications WO2019155157 or WO2021028624, for example.

[0063] In the embodiment shown, the inner face of the insulating panels 16 has two series of grooves 22 perpendicular to each other and intended to receive corrugations 24, projecting towards the outside of the tank, formed on corrugated metal sheets 25 of the secondary waterproofing membrane 13 (described in more detail below). Each of the series of grooves 22 is parallel to two opposite sides of the insulating panels 16. In the embodiment shown, the grooves 22 pass entirely through the thickness of the inner plate 10 as well as an inner portion of the insulating polymer foam layer 17. Advantageously, the grooves 22 have a shape complementary to those of the corrugations 24 of the secondary waterproofing membrane 13.

[0064] Furthermore, the inner plate 18 of the insulating panels 16 is equipped with metal plates (not visible in the figures) intended for anchoring the edges of the corrugated metal sheets 25 of the secondary waterproofing membrane 13 on the insulating panels 16. The metal plates extend in two perpendicular directions which are each parallel to one of the two opposite sides of the insulating panels 16. The metal plates 26 are fixed to the inner plate 18 of the insulating panels 16, by screws, rivets or staples, for example. The metal plates are placed in recesses provided in the inner plate 18 so that the inner surface of the metal plates 26 is flush with the inner surface of the inner plate 18 ().

[0065] Furthermore, the insulating panels 16 have relaxation slots 27 which make it possible to reduce their stiffness so that the secondary thermally insulating barrier 12 deforms in the most homogeneous manner possible. This makes it possible to obtain the most uniform deformations possible of the corrugations 24 of the secondary waterproofing membrane 13. Advantageously, the insulating panels 16 have relaxation slots 27 at least opposite each of the corrugations 24 of the secondary waterproofing membrane 13. Thus, as illustrated for example in the, a relaxation slot 27 extends from the bottom of each of the grooves 22 towards the external plate 19 of the insulating panels 16. In addition, the insulating blocks 16 here also comprise additional relaxation slots 28 which open onto the external face of the insulating panels 16 which rests on the external plate 18.The additional relaxation slots are arranged halfway between two parallel undulations 24, that is to say halfway between two relaxation slots 27 ().

[0066] The secondary waterproofing membrane 13 rests against the secondary thermally insulating barrier 12. It comprises a plurality of corrugated metal sheets 25 each having a substantially rectangular shape. The corrugated metal sheets 25 are, for example, made of Invar®: that is to say an alloy of iron and nickel whose coefficient of expansion is typically between 1.2.10 -6 and 2.10 -6 K -1 , or in an iron alloy with a high manganese content whose coefficient of expansion is typically of the order of 7.10 -6 K -1 Alternatively, the corrugated metal sheets 25 can also be made of stainless steel or aluminum.

[0067] The corrugated metal sheets 25 are overlap-welded along their edges in order to ensure the sealing of the secondary waterproofing membrane 13. Furthermore, the corrugated metal sheets 25 are arranged in an offset manner relative to the insulating panels 16 of the secondary thermally insulating barrier 12 such that each of said corrugated metal sheets 25 extends jointly over several adjacent insulating panels 16. In order to ensure the anchoring of the secondary waterproofing membrane 13 on the secondary thermally insulating barrier 12, the edges of the corrugated metal sheets 25 are welded to the metal plates 26, for example by spot welding.

[0068] The secondary sealing membrane 13 has corrugations 24 and more particularly a first series of corrugations extending parallel to a first direction and a second series of corrugations extending parallel to a second direction. The directions of the series of corrugations are perpendicular to each other. Each of the series of corrugations is parallel to two opposite edges of the corrugated metal sheet 25. The corrugations 24 here project towards the outside of the tank, that is to say in the direction of the supporting structure 1. The secondary sealing membrane 13 comprises, between the corrugations 24, a plurality of flat zones 28 ().

[0069] As shown in the, the corrugations 24 of the corrugated metal sheets 25 are housed in the grooves 22 formed in the internal face of the insulating panels 16. They can also be housed in the interstices formed between the adjacent insulating panels 16.

[0070] Furthermore, the flat zones 28 of the secondary waterproofing membrane 13 are each crossed by a primary anchoring device intended to ensure the anchoring of the load-bearing elements 30 of the primary thermally insulating barrier 14 on the insulating panels 16 of the secondary thermally insulating barrier 12. Each primary anchoring device comprises a stud (not visible on the) which passes through the secondary waterproofing membrane 13, one outer end of which is fixed to one of the insulating panels 16. The stud comprises a collar developing radially relative to the axis of the stud and welded in a sealed manner on the secondary waterproofing membrane 13 around the orifice of said secondary waterproofing membrane 13 crossed by the stud in order to maintain the sealed nature of the secondary waterproofing membrane 13.

[0071] Furthermore, an external plate 34, illustrated in the, has an orifice crossed by the stud. The primary anchoring device comprises a nut which is screwed onto a threaded internal end of the stud and which thus makes it possible to hold the external plate 34 against the flat zone 28 opposite the secondary waterproofing membrane 13. The external plates 34 have a dual function. On the one hand, they make it possible to press the secondary waterproofing membrane 13 against the insulating panels 16 of the secondary thermally insulating barrier 12, in order to prevent it from being torn off due to excess pressure of the secondary thermally insulating barrier 12 relative to the primary thermally insulating barrier 14. On the other hand, they allow the fixing of the load-bearing elements 30 of the primary thermally insulating barrier 14 which will be described in detail below.

[0072] The external plates 34 are advantageously in contact against the corresponding flat zone 28 over more than 70% of the surface of said flat zone 28 and advantageously between 90 and 100% of its surface.

[0073] The external plates 34 are, for example, made of metal, such as stainless steel, but can also be made of a composite material, such as an epoxy resin loaded with glass fibers, for example.

[0074] The primary thermally insulating barrier 14 rests against the secondary waterproofing membrane 13.

[0075] It comprises a plurality of supporting elements 30 which extend along the thickness direction D of the wall 10. The supporting elements 30 make it possible to support the primary sealing membrane 15 and, consequently, to take up the forces due to the hydrostatic and dynamic pressures exerted on the primary sealing membrane 15 by the liquefied gas contained inside the tank. The supporting elements 30 are aligned in rows which are parallel to the direction of the undulations of the first series of undulations and in rows parallel to the direction of the undulations of the second series of undulations.

[0076] The supporting elements 30 each comprise an external base 36, an internal base 37 and a pillar 38 extending between the external base 36 and the internal base 37. The external base 36 and the internal base 37 each have a sleeve 39 in which one of the ends of the pillar 38 is received by fitting and a support collar 40 which extends radially from one end of the sleeve 39 orthogonally thereto. In an alternative variant, it is the sleeves of the external base and the internal base which are received by fitting inside the pillars.

[0077] The external base 36 and the internal base 37 may be made of metal, such as stainless steel, or of a composite material, such as an epoxy resin filled with glass fibers, for example. The external base 36 and the internal base 37 may be fixed to the pillar 38 by any means and in particular by gluing.

[0078] According to another embodiment, the pillar as well as the external base and the internal base are formed in one piece, by molding for example.

[0079] The pillars 38 have a tubular shape, preferably with a circular section. They extend in a direction parallel to the thickness direction D of the wall. According to an advantageous embodiment, the pillars 38 are made of a composite material comprising fibers and a matrix. Such pillars 38 make it possible to obtain satisfactory compressive strength for a limited conductive section, which limits the conduction of heat from the outside to the inside of the tank through the pillars 38. The fibers are, for example, chosen from glass fibers, carbon fibers, aramid fibers, flax fibers, basalt fibers and mixtures thereof.The matrix is ​​for example chosen from polyethylene, polypropylene, poly(ethylene terephthalate), polyamide, polyoxymethylene, polyetherimide, polyacrylate, polyaryletherketone, polyetheretherketone, copolymers thereof, polyester, vinylester, epoxy and polyurethane. According to a particular embodiment, the pillars 38 are made of an epoxy resin reinforced with glass fibers.

[0080] The pillars 38 are advantageously provided with through-holes, not shown, which facilitate the depressurization of their internal space when the primary thermally insulating barrier 14 is depressurized, as described below. In addition, the internal space of the pillars 38 is advantageously lined with a gas-permeable insulating lining and more particularly made of a porous open-cell material. The insulating lining is, for example, an open-cell insulating polymer foam, such as open-cell polyurethane foam, glass wool, rock wool, melamine foam, polyester wadding, polymer aerogels, such as polyurethane-based aerogel, notably sold under the brand name Slentite ®, or silica aerogels.

[0081] The support collars 40 of the external bases 36 are each fixed to one of the external plates 34, for example by means of rivets distributed around the axis of the supporting element 30.

[0082] Furthermore, the support collars 40 of the internal bases 37 are each supported and fixed against an internal plate 42. The internal plates 42 are, for example, made of a metal, such as stainless steel. The support collars 40 of the internal bases 37 are, for example, fixed to the internal plate 42 by means of rivets distributed around the axis of the carrier element 30.

[0083] The load-bearing elements 30 thus form discrete support structures which are not rigidly connected to each other and which each support a flat area 46 of the primary waterproofing membrane 15 (described below), which allows good distribution of the stresses in the primary waterproofing membrane 15.

[0084] The primary sealing membrane 15 rests against the primary thermally insulating barrier 14 and is intended to be in contact with the liquefied gas contained in the tank.

[0085] It is also obtained by assembling a plurality of corrugated metal sheets. The corrugated metal sheets each have a substantially rectangular shape. The corrugated metal sheets are, for example, made of Invar®: that is to say an alloy of iron and nickel whose coefficient of expansion is typically between 1.2.10 -6 and 2.10 -6 K -1 , or in an iron alloy with a high manganese content whose coefficient of expansion is typically of the order of 7.10 -6 K -1 Alternatively, corrugated metal sheets can also be made of stainless steel or aluminum.

[0086] The corrugated metal sheets forming the primary waterproofing membrane 15 are overlap welded along their edges in order to ensure the waterproofing of the primary waterproofing membrane 15. The primary waterproofing membrane 15 comprises corrugations 45. More particularly, it comprises a first series of corrugations extending parallel to a first direction and a second series of corrugations extending parallel to a second direction. The directions of the series of corrugations are perpendicular and are parallel or perpendicular to the rows of load-bearing elements 30. Each of the series of corrugations is parallel to two opposite edges of the corrugated metal sheets of the primary waterproofing membrane 15. The corrugations 45 project towards the inside of the tank, i.e. in the opposite direction to the load-bearing structure 1. Each corrugated metal sheet comprises, between the corrugations 45, a plurality of flat areas 46 ().

[0087] The pitch of the corrugations 24 of the secondary waterproofing membrane 13 is equal to the pitch of the corrugations 45 of the primary waterproofing membrane 15 or to an integer multiple thereof. In addition, each of the corrugations 24 of the secondary waterproofing membrane 13 is arranged opposite, in the thickness direction of the wall 11, a corrugation 45 of the primary waterproofing membrane 15 (). Thus, each flat zone 46 of the primary waterproofing membrane 15 is located opposite, in the thickness direction D of the wall 11, a flat zone 28 of the secondary waterproofing membrane 13. Therefore, the axis of each supporting element 30 passes both through the center of a flat zone 46 of the primary waterproofing membrane 15 and through the center of a flat zone 28 of the secondary waterproofing membrane 13.

[0088] Advantageously, the internal plates 42 are each in contact against the corresponding flat zone 46 of the primary sealing membrane 15 over more than 70% of the surface of said flat zone 46 and advantageously between 90 and 100% of its surface.

[0089] The corrugated metal sheets of the primary waterproofing membrane 15 are at least anchored, by welding, along their edges on the internal plates 42. To do this, the edges of the corrugated metal sheets are welded to the internal plates 42, for example by spot welds.

[0090] According to an advantageous embodiment, the corrugated metal sheets are also anchored to the internal plates 42 outside their edge areas. To do this, the corrugated metal sheets can in particular be welded to the internal plates 42 by transparent welds. According to an advantageous embodiment, the corrugated metal sheets are welded to each of the internal plates 42 which support them. Such an embodiment is particularly advantageous in that it makes it possible to distribute the stresses even more uniformly between the corrugations 45 of the primary waterproofing membrane 15.

[0091] Furthermore, the primary thermally insulating barrier 14 has a gas phase which is under vacuum, that is to say has an absolute pressure lower than atmospheric pressure, in order to give the primary thermally insulating barrier 14 the required thermally insulating properties. The gas phase of the primary thermally insulating barrier 14 is, advantageously, placed at an absolute pressure lower than 1 Pa, advantageously lower than 10 -1 Pa, preferably less than 10 –2 Pa and for example of the order of 10 -3 Pa. To do this, the primary thermally insulating barrier 14 is advantageously connected to a vacuum pump.

[0092] According to an advantageous embodiment, a cryopumping phenomenon is used, as an alternative or complement to the aforementioned vacuum pump, to obtain the target depression level in the primary thermally insulating barrier 14. Also, prior to its depression, the primary thermally insulating barrier 14 is charged with an inert gas having a solid condensation temperature higher than the liquefaction temperature of the liquefied gas stored in the tank. For example, when the liquefied gas stored in the tank is liquid hydrogen, the inert gas may be carbon dioxide. Thus, taking into account the temperature of the hydrogen in the liquid state, the carbon dioxide contained in the primary thermally insulating barrier 14 condenses in the solid state in the primary thermally insulating barrier 14, which contributes to reducing the pressure therein.

[0093] In addition to being depressurized, the primary thermally insulating barrier 14 comprises insulating materials to further increase its insulation properties. Also, as shown in the, the primary thermally insulating barrier 14 further comprises a radiative multi-layer insulation blanket 47 which reduces heat transfer by thermal radiation. The radiative multi-layer insulation blanket 47 is typically made of a material designated by the acronym MLI for “multi-layer insulation” in English.

[0094] Thus, the radiative multilayer insulation blanket 47 has a stack of a plurality of sheets made either of metal, such as aluminum or silver for example, or of a polymer material coated with metal, said sheets being separated from each other by a textile layer made with polymer fibers, such as polyester fibers, or glass fibers. The sheets of plastic material are, for example, made of Polyimide, in particular marketed under the brand Kapton ®, or of polyethylene terephthalate, in particular marketed under the brand Mylar ®. These thin sheets are coated, on each side, with a metal, such as aluminum or silver. In the description of the invention, although not mentioned subsequently, the radiative multilayer insulation blanket 47 may further comprise an additional thermal protection layer made of resistant materials of the glass fiber type.Such a layer makes it possible to protect the cover 47 against external attacks, for example thermal projections due to the welds of the membrane near the cover 47.

[0095] As illustrated in Figures 1 and 8, the radiative multilayer insulation cover 47 has openings 47A (visible in the) through which the pillars 38 of the load-bearing elements 30 pass. The radiative insulation cover 47 extends transversely to the thickness direction D of the wall 10, that is to say in an inclined manner relative to the thickness direction D.

[0096] Advantageously, the radiative multi-layer insulation blanket 47 is positioned in the coldest part of the primary thermally insulating barrier 14. In other words, the radiative multi-layer insulation blanket 47 is positioned in a plane which is parallel to the secondary 13 and primary 15 waterproofing membranes but is closer to the primary waterproofing membrane 15 than to the secondary waterproofing membrane 13. This makes it possible to increase the effectiveness of the radiative multi-layer insulation blanket 47 since it is thus positioned in the coldest area of ​​the primary thermally insulating barrier 14 so that the emissivity of each of its layers is reduced. However, it is also possible to position the radiative multi-layer insulation blanket 47 in a plane parallel to the waterproofing membranes, closer to the secondary waterproofing membrane to ensure good effectiveness of the blanket.

[0097] The radiative multilayer insulation cover 47 is fixed to at least one of the supporting elements 30 by a fixing device 51; 52; 53; 54; 55, comprising a connecting part 511; 521; 531; 541; 551 fixed on said supporting element 30 and a support part 512; 522; 532; 542; 552 extending transversely to the thickness direction D of the wall 10.

[0098] The insulation cover 47 is fixed on said support part 512; 522; 532; 542; 552. More precisely, the insulation cover 47 is fixed directly on said support part 512; 522; 532; 542; 552. It is in contact with the fixing device at its support part.

[0099] The connecting part 511; 521; 531; 541; 551 of the fixing device 51; 52; 53; 54; 55 comprises two portions 511A, 511B; 521A, 521B; 531A, 531B; 541A; 551A, 551B movable relative to each other between a spaced position in which the two portions are spaced apart from each other to allow the carrier element 30 to be placed through the fixing device 51; 52; 53; 54; 55 so that the fixing device 51; 52; 53; 54; 55 surrounds the carrier element 30, and a bringing-together position in which the two portions are brought closer to each other relative to the separation position, so as to be able to immobilize the fixing device 51; 52; 53; 54; 55 on the carrier element 30 by clamping on the carrier element.

[0100] The fixing device in the position of bringing the two portions together is therefore suitable for clamping the supporting element.

[0101] The fixing device 51; 52; 53; 54; 55 is more particularly immobilized on the carrier element 30 by gluing the fixing device 51; 52; 53; 54; 55 onto the carrier element 30 and / or by elastic clamping of the carrier element 30 and / or by axial locking along the carrier element by pressing on a stop element projecting from the carrier element.

[0102] The carrier element 30 has a central portion located between the external 36 and internal 37 bases of the carrier element 30, which belongs to the pillar 38. The two portions of the connecting portion 511; 521; 531; 541; 551 of the fixing device form, in their approach position, a collar whose internal dimensions are equal, to within a clearance, to the external dimensions of the central portion of the carrier element 30. By way of non-limiting example, for an external diameter of the central portion of the carrier element of 62.5 mm, this clearance may be between 0 and 3 mm, preferably between 0 and 2 mm. This clearance corresponds to the thickness of the bonding between the carrier element and the connecting portion (a clearance of 0 mm corresponding to a so-called clamping position in which the connecting device is fixed and clamped against the carrier element). Advantageously, the clearance is between 100 and 200 µm (micrometers).

[0103] This collar has a main axis X which extends in the direction of pillar 38, that is to say in the direction of thickness D of the wall.

[0104] The support portion 512; 522; 532; 542; 552 of the fixing device comprises at least one tab 512A; 522A; 532A; 542A; 552A extending projecting from the connecting portion.

[0105] This tab is formed or is attached to the said connecting part of the fixing device.

[0106] According to the first, second and third embodiments of the wall 10, the connecting part 511; 521; 531 and the support part 512; 522; 532 of the fixing device 51, 52, 53 are produced by one or more metal plates, as shown in FIGS. 2 to 5.

[0107] In these embodiments, each portion of the connecting part 511; 521; 531 is made by a plate 513; 523; 533 of metal of elongated shape along a longitudinal axis L () which is shaped so as to match the contour of the central part of the carrier element 30. The central part of the carrier element corresponds here to an area of ​​the pillar 38 located between the external base 36 and the internal base 37 of the carrier element 38. The plate 513; 523; 533 has a generally rectangular shape before shaping, delimited by two parallel longitudinal edges C1, C2 connected by two longitudinal end edges C3, C4 ().

[0108] The pillar 38 here having a cylindrical shape, each portion of the connecting part 511; 521; 531 is curved so as to form a cylindrical half-sleeve of main axis X.

[0109] The support portion 512; 522; 532 of the fixing device 51; 52; 53 comprises a plurality of plates forming the tabs 512A; 522A; 532A. An even number of plates are preferably provided, arranged so as to be diametrically opposed around the pillar 38 when the fixing device is installed around the pillar.

[0110] These plates may come from formation with the plate 513; 523 constituting each portion 511A; 521A of the connecting part, as is the case in the first and second embodiments of figures 2, 3 and 4.

[0111] In this case, each plate 512A; 522A extends from the same longitudinal edge of the plate 513, 523 and is folded relative to the plate 513; 523 so as to extend in a plane transverse to the main axis X of the connecting part.

[0112] This transverse plane is here orthogonal to the main axis X of the connecting part of the fixing device. Alternatively, it could be provided that the transverse plane is inclined at a non-zero angle other than 90°.

[0113] When the fixing device is in place around the supporting element, the main axis X of the connecting part 511; 521; 531; 541; 551 of the fixing device is parallel to the thickness direction D of the wall, along which the supporting elements 30 rise.

[0114] The plate 513; 523 is preferably curved, providing a flat 514; 524 in correspondence with each plate 512A; 522A (figures 2 and 4), so as to facilitate the folding thereof and limit the stresses.

[0115] Lamontre shows one of the portions of the connecting part flat, before its shaping. The plates and the plate are formed by cutting from a single flat sheet. The references 512P and 513P designate respectively the plates and the plate of the portion of the connecting part before the shaping of the sheet. For example, the sheet has a thickness of 1 millimeter.

[0116] Each plate 532A can also be attached to the metal plate 533 constituting each portion of the connecting part 531, as in the third embodiment shown in the.

[0117] The plates 532A forming the support part 532 of the fixing device 53 according to the third embodiment shown in the are here welded onto the plate 533 forming the connecting part after the latter has been bent. No flat is then provided in the plate 533 of the connecting part.

[0118] In the first, second and third embodiments of Figures 2 to 5, the ends of each portion of the connecting part constitute attachment ends allowing the two portions of the connecting part to be joined together.

[0119] In the first embodiment of the, the two portions 511A, 511B of the connecting part 511 are connected by at least one hinge.

[0120] The attachment ends of each portion 511A, 511B of the connecting part 511 form at least one hinge. Here, the attachment ends form two hinges.

[0121] One of the attachment ends comprises a central tongue 516 extending along the longitudinal axis of the plate 513 and delimited by two lateral notches 516A formed in the longitudinal edges of the plate 513 up to one of the longitudinal end edges of this plate 513. The other attachment end comprises two lateral tongues 515 extending along the longitudinal axis L of the plate 513 and delimited by a central notch 515A formed in the longitudinal end edge of the plate 513.

[0122] The side notches 516A and central notches 515A are complementary to each other.

[0123] The figure shows the notches and tongues 515P, 516P as cut in the sheet metal forming the inserts 512A and the plate 513, when this sheet metal is still flat. The unformed inserts and the plate are referenced respectively 512P and 513P in this figure.

[0124] Each central tongue 516 and lateral tongue 515 is curved towards the outside of the half-sleeve formed by the portion of the connecting part so as to form a receiving housing 515B, 516B - also called "knuckle" - of the hinge, adapted to receive a pin 519 forming the axis of rotation of the hinge. Each of these receiving housings 515B, 516B extends in a direction parallel to the main axis X of the cylindrical half-sleeve formed by each portion 511A, 511B of the connecting part 511. The central tongue 516 of one of the portions 511A, 511B of the connecting part 511 is received between the lateral tongues 515, in the central notch 516A of the other portion 511B, 511A of the connecting part 511, so as to be able to align the receiving housings 515B, 516B formed by the central and lateral tongues.

[0125] Advantageously, the receiving housing 516B formed by the central tongue 516A of the plate 513 has an oblong shape, elongated along the longitudinal axis L of the plate 513 (). The central tongue 516A of one of the portions of the connecting part can further slide in the central notch 515A of the other portion. Thus, the relative position of the two portions of the connecting part can be adjusted. The internal dimensions of the connecting part 511 of the fixing element can thus also be adjusted.

[0126] Hinge-forming attachment ends, similar to those described above, are also provided in the third embodiment, as seen in the.

[0127] In the second embodiment, the two portions of the connecting part are connected by at least one staple. This staple 529 has a U shape with a base from which two lateral branches extend. In the example shown in the, two staples 529 are used to assemble the two portions of the connecting part of the fixing element 52.

[0128] As shown in the, each longitudinal end 524A, 524B of each portion 521A, 521B of the connecting part 521 is here curved towards the outside of the half-sleeve formed by the portion 521A, 521B of the connecting part so as to form a receiving housing 525A, 525B extending along the main axis X of the cylindrical half-sleeve formed by each portion of the connecting part and adapted to receive one of the two lateral branches of the rider 529.

[0129] The staple 529 is made of metal wire and preferably has an elasticity allowing elastic separation of the two branches inserted into the receiving housings of the two portions 521A, 521B of the connecting part 521 of the fixing element 52. This elasticity is here provided by an elbow 529A formed in the base of the U formed by the staple 529.

[0130] Each branch of the jumper 529 passes through the receiving housings 525A, 525B of each portion 521A, 521B. A free end of one of the branches of the jumper 529 is curved outside the receiving housing so that the jumper 529 cannot be removed from the receiving housing of one of the portions of the connecting part. The free end of the other branch is straight and can slide freely in the receiving housing of the other portion. It is expected that one of the two jumpers 529 is thus connected to each portion.

[0131] Preferably, as shown in the, one of the two jumpers 529 is inserted into the receiving housings 525A, 525B of the two portions 521A, 521B so that its base is oriented towards the primary membrane 15 and the other jumper is inserted into the receiving housings 525A, 525B of the two portions 521A, 521B so that its base is oriented towards the secondary membrane 13.

[0132] The connecting part 511; 521; 531 of the fixing device 51; 52; 53 is fixed to the carrier element 30 for example by gluing.

[0133] Alternatively, the connecting portion of the fixing device may be immobilized on the supporting element by pressing on at least one stop element of the supporting element extending projecting from the central portion of the supporting element. The connecting portion of the fixing device then rests on the stop element. The axial movement of the fixing device towards the outside of the wall is limited by the stop element. One or more other stop elements may be added on the other side of the fixing device, towards the inside of the wall, in order to block any axial movement of the fixing device along the pillar. The connecting portion of the fixing device may further be glued around the supporting element.

[0134] The two portions 511A, 511B; 521A, 521B; 531A, 531B of the connecting part are movable relative to each other, either by pivoting thanks to the hinge or the clip, or because they can be separated from each other, either thanks to the elastic properties of the clip, or by translation in the oblong-shaped receiving housing 516B formed by the central tongue 516A of each portion. They are spaced apart from each other and placed in a spaced-apart position to allow the carrier element to be placed through the fixing device so that the fixing device surrounds the carrier element.

[0135] For this purpose, the two portions may be completely or partially separated from each other or not.

[0136] Preferably, the two portions remain attached by two of the attachment ends, while the cooperation between the other two attachment ends is broken. One of the hinges or one of the clips remains in cooperation with the two portions of the connecting part. The pin of the other hinge is removed to release the two portions or the right branch of the other clip is removed from its receiving housing. The separation position of the two portions of the connecting part then corresponds to an opening configuration of the fixing device. The two portions are pivoted relative to each other and separated so that the pillar 38 can pass laterally between the two portions of the fixing device. The relative movement of the pillar and the fixing device is transverse to the direction of thickness of the wall.

[0137] When the fixing device 51; 52; 53 is located at the desired height along the supporting element 30, the portions of the connecting part of the fixing device are then closed around the pillar and the cooperation of the other attachment ends is re-established. The portions of the connecting part are then in their approach position.

[0138] This is particularly useful when the carrier element 30 already has its internal base 39 at the time when the fixing device 51; 52; 53 is installed.

[0139] In some cases, the fixing device can be slipped onto the pillar 38 without breaking the cooperation of the attachment ends of the two portions of the connecting part of the fixing device, for example when the fixing device is installed before the internal base 39 is fixed on the end of the pillar 38. Then, the two portions of the connecting part can be separated, either, in the first and third embodiments, by sliding the pin 519 in the oblong-shaped receiving housing 516B formed by the central tongue 516A, or, in the second embodiment, by elastically deforming the rider 529. The fixing device remains in a closed configuration.

[0140] The fixing device 52 is then slid along the pillar 38. The positioning of the fixing device 52 around the load-bearing element then involves an axial movement of the fixing device, along the thickness direction D of the wall.

[0141] When the fixing device 51; 52; 53 is located at the desired height along the carrier element 30, the portions of the connecting part are brought together in their closed position so as to be able to immobilize the fixing device on the carrier element.

[0142] The fixing device is immobilized on the carrier element by gluing the fixing device to the carrier element and / or by elastically clamping the carrier element and / or by pressing on at least one stop element of the carrier element extending projecting from the central part of the carrier element.

[0143] A layer of glue is applied between the connecting part and the pillar.

[0144] In the case of the first embodiment, a temporary holding device can be used to tighten the fixing device around the pillar while the glue sets.

[0145] This temporary holding device may, for example, include a removable plastic collar. It tightens the fixing device against the abutment while the glue sets.

[0146] In the case of the second embodiment, the internal dimensions of the connecting part of the fixing device are determined so that this connecting part clamps the pillar in the rest position of the clips 529. This clamping is sufficient to hold the fixing device 52 in place while the glue sets.

[0147] According to other embodiments, the connecting part 541; 551 and the support part 542; 552 of the fixing device 54; 55 belong to a metal spring wire or to a metal spring blade.

[0148] For example, according to the fourth and fifth embodiments of the wall 10, the connecting part 541; 551 and the supporting part 542; 552 of the fixing device 54; 55 belong to a metal spring wire 540, 550.

[0149] In these embodiments, the two portions 541A, 541B; 551A, 551B of the connecting part 541; 551 are made by a single spring wire which is shaped so as to match the contour of the central part of the carrier element 30. The central part of the carrier element corresponds to the area of ​​the pillar 38 located between the external base 36 and the internal base 37 of the carrier element 38.

[0150] The pillar 38 here having a cylindrical shape, the spring wire is wound so as to form a single turn or a plurality of turns of main axis X around the supporting element 30.

[0151] Thanks to the elastic deformation properties of the spring wire or spring blade, it is possible to separate the two ends of the spring wire or spring blade in order to increase the internal dimensions of the connecting part of the fixing device thus formed, as shown schematically in the: by bringing the loops B1 and B2 located at the ends of the spring wire closer together, the parts of the spring wire adjacent to these loops move away and the turns deform so as to have a larger diameter.

[0152] In the fourth embodiment of Figures 6 and 7, the spring wire forms 3.25 turns, while in the fifth embodiment of the, the spring wire forms a single turn.

[0153] The support portion 542; 552 of the fixing device 54; 55 comprises a plurality of folds of the spring wire forming the tabs 542A; 552A. An even number of folds are preferably provided, arranged so as to be diametrically opposed around the pillar 38 when the fixing device is installed around the pillar.

[0154] The folds forming the tabs 542A; 552A extend from the part of the spring wire forming the turn closest to the primary membrane 15.

[0155] The folds forming the tabs may comprise loops or undulations of the spring wire. In the example of the fourth embodiment, four tabs are provided formed by two loops B1, B2 and two undulations B3, B4. The loops B1, B2 are closed on themselves while the undulations are open.

[0156] These folds extend in a plane transverse to the main axis X of the connecting part. This transverse plane is here orthogonal to the main axis X.

[0157] In the fifth embodiment, the two ends of the spring wire are folded towards the secondary membrane: one forms a hook 553 and the other forms a hooking element 554 which cooperates with the hook to hold the two ends of the spring wire together.

[0158] The hook 553 and the hooking element 554 extend parallel to the main axis X. They are nested within each other so that they can elastically move apart from each other. The hooking element can move within the hook 553 so that the two ends of the spring wire can move apart under stress and then come together when the spring wire returns to its resting shape.

[0159] In the embodiments in which the fixing device is formed by a spring wire or a spring blade, the connecting portion 541; 551 of the fixing device 54; 55 elastically grips the carrier element 30. For this purpose, the internal dimensions of the connecting portion at rest are determined to be slightly smaller than the external dimensions of the central portion of the carrier element around which the fixing device is installed.

[0160] It is also possible to provide that the spring wire or the spring blade is glued to the carrier element 30.

[0161] In the latter case, gluing is carried out in addition to or instead of elastic clamping. When gluing replaces elastic clamping, the internal dimensions of the connecting part may be equal, apart from a clearance accommodating the glue, to the external dimensions of the supporting element.

[0162] When gluing is carried out in addition to elastic clamping, partial or specific gluing of the connecting part can be provided.

[0163] In particular, in the fifth embodiment shown in the, a plurality of additional folds of the spring wire constituting the fixing device are provided, oriented towards the secondary membrane and extending parallel to the main axis X.

[0164] The additional folds are distributed regularly around the circumference of the connecting part. There are three of them here. A point of glue is placed at the end of each additional fold. This localized gluing on a part of the spring wire whose length is very short compared to its total length in contact with the carrier element 30 makes it possible to preserve the elastic properties and to guarantee the fixing of the connecting part on the carrier element 30 in the event of thermal contraction of the latter, without increasing the tightening of the carrier element by the fixing device.

[0165] It is not outside the scope of the invention if the two portions 541A, 541B; 551A, 551B of the connecting part 541; 551 are made of a single aluminum blade which is shaped so as to match the contour of the central part of the carrier element 30. Such a blade takes the form of a monolithic bracelet, for example made of 1000 series aluminum alloy (consisting of 99% or more aluminum) capable of being deformed when it is put in place around the carrier element 30. This bracelet has the ductility required to allow its deformation. Once put in position around the carrier element, the bracelet can be closed by a jumper, in a manner similar to that described previously.

[0166] As a variant or in addition to the fixing by gluing or clamping described previously for the first, second, third, fourth and fifth embodiments, the connecting part of the fixing device rests on at least one stop element of the carrier element extending in projection from a central part of the carrier element.

[0167] For this purpose, the pillar may comprise a plurality of bosses, for example diametrically opposed, on which the connecting part of the fixing device rests.

[0168] The support portion 512; 522; 532; 542; 552 of the fixing device 51; 52; 53; 54; 55 comprises a fixing element 518; 528; 538; 548; 558 of the multi-layer insulation cover adapted to cooperate with a complementary fixing element 560 of the fixing device.

[0169] In the embodiments shown in the attached figures, the fixing element 518; 528; 538; 548; 558 of the support part 512; 522; 532; 542; 552 is a through hole.

[0170] The complementary fixing element 560 is for example a fir tree clip as shown in Figures 8 and 9. This fir tree clip comprises a head and a body provided with retaining pins.

[0171] The multi-layer insulation cover 47 comprises an opening 48 located opposite each through hole of the fixing element ().

[0172] The body of the fir clip 560 is passed through this opening 48 of the multi-layer insulation cover 47 and through the through hole forming the corresponding fixing element 518; 528; 538; 548; 558 of the fixing device 51; 52; 53; 54; 55.

[0173] Alternatively, the complementary fastening element of the fastening device may also be a pin or a rivet.

[0174] Alternatively, the complementary fastening element of the fastening device may also comprise a first part of a self-gripping strip of the velour or hook type and the multi-layer insulation blanket may then comprise the second complementary part of the self-gripping strip, of the hook or velour type, respectively.

[0175] After the fixing device 51; 52; 53; 54; 55 has been placed on the supporting element 30, the multilayer insulation cover 47 is slipped onto the supporting element 30 by passing the latter through an opening 47A made in the multilayer insulation cover. This opening 47A has a contour adapted to a clearance close to the external contour of the pillar 38 surrounded by the multilayer insulation cover 47. The opening 47 may be extended by radial slots 47B, for example 4 in number, which facilitate the passage of the cover over the pillar 38.

[0176] The fir-tree staples or other complementary fixing elements are driven through the openings 48 of the multi-layer insulation blanket 47 and through the through holes of the support part 512; 522; 532; 542; 552, so as to fix the blanket on the fixing device.

[0177] A fixing device 51; 52; 53; 54; 55 is for example provided on all the load-bearing elements 30 of the primary thermally insulating barrier 14.

[0178] Alternatively, a fixing device is attached to a number of load-bearing elements strictly less than the total number of load-bearing elements of the primary thermally insulating barrier, for example, a fixing device is attached to every other load-bearing element so that the load-bearing elements comprising a fixing device and a load-bearing element not comprising any fixing device, for the same multi-layer insulation cover, are alternated in the two directions of alignment of the load-bearing elements.

[0179] The primary thermally insulating barrier 14 further comprises insulating elements 49 which have a porous structure with open cells and which are arranged between the radiative multi-layer insulation cover 47 and the secondary sealing membrane 13.

[0180] Such insulating elements 49 have several functionalities. First, they make it possible to further reduce the temperature of the area of ​​the primary thermally insulating barrier 14 in which the radiative multilayer insulation blanket 47 is positioned, which further increases its effectiveness. Second, the insulating elements 49 also make it possible to limit the degradation of the thermal insulation performance when the pressure inside the primary thermally insulating barrier 14 is higher than the pressure values ​​prescribed for the use of the radiative multilayer insulation blanket 47 alone.

[0181] Indeed, the radiative multilayer insulation blankets 47 of the aforementioned type have excellent thermal insulation performance for low pressure values, typically less than or equal to 10 -3Pa but the more they are subjected to pressures above the aforementioned threshold, the more their performance deteriorates. Such pressure conditions are particularly likely to occur in the event of loss of tightness of the primary sealing membrane 15 or of the secondary sealing membrane 13 degrading the level of depression inside the primary thermally insulating barrier 14 or when the tank is cooled down as long as the inert gas contained in the primary thermally insulating barrier 14 has not entirely condensed to the solid state or when the filling rate of the tank is low, for example during a return voyage of a ship when the tank only has a heel of liquefied gas. The insulating elements 49 also make it possible to reduce the activation capacities of convective flows inside the primary thermally insulating barrier 14.Thirdly, the insulating elements 49 constitute surfaces for receiving the solids resulting from the solid condensation of the inert gas(es) contained in the primary thermally insulating barrier 14, which makes it possible to limit the mechanical stresses likely to be exerted on the other elements of the wall 10 and in particular on the load-bearing elements 30, the radiative multi-layer insulation cover 47 and the secondary 13 and primary 15 sealing membranes.

[0182] The insulating elements 49 are, for example, chosen from glass wool, rock wool, polyester wadding, open-cell polymer foams, such as open-cell polyurethane foam, and melamine foams. Advantageously, the insulating elements 49 are made of glass wool. The insulating elements 49 are advantageously packaged in the form of panels having a structural strength allowing them to be handled easily.

[0183] In the embodiment of the, the insulating elements 49 have a thickness less than the distance, in the thickness direction of the wall 11, between the secondary sealing membrane 13 and the radiative multilayer insulation blanket 47. In other words, an empty space is present between the insulating elements 49 and the radiative multilayer insulation blanket 47. This makes it possible to reduce the quantity of insulating elements 49 used and thus contributes to reducing the costs of the tank without significantly degrading the thermal insulation performance of the primary thermally insulating barrier 14, in particular when the pressure inside the primary thermally insulating barrier 14 is higher than the prescribed pressure value.

[0184] According to another embodiment not shown, the insulating elements can occupy the entire space between the radiative multi-layer insulation cover and the secondary sealing membrane. The secondary thermally insulating barrier can then further comprise one or more retention members making it possible to limit the movement of the insulating elements towards the primary sealing membrane and thus prevent them from compressing the radiative multi-layer insulation cover and thus degrading its performance.

[0185] According to another embodiment, the corrugations of the secondary waterproofing membrane do not protrude outwards, i.e. towards the supporting structure, but inwards, i.e. in a direction opposite to the supporting structure.

[0186] According to another embodiment of the wall of a sealed and thermally insulating tank, the primary sealing membrane has two layers of corrugated metal sheets superimposed on each other, as described in document FR3134571 with reference to figure number 11 of this document. This ensures redundancy of the sealing function and thus improves the reliability of the primary sealing membrane.

[0187] The two layers of corrugated metal sheets each have a structure similar to that of the primary waterproofing membrane described above. The corrugations of the two layers are arranged at identical pitches and are arranged opposite each other in the direction of wall thickness.

[0188] Such membrane tanks can be used for the storage and / or transport of a low-temperature liquid, such as Liquefied Natural Gas (LNG) at approximately -162°C at atmospheric pressure, Liquid Hydrogen (LH2) at -253°C at atmospheric pressure, Ammonia (NH3) at -30°C at atmospheric pressure or Liquefied Petroleum Gas (also called LPG) with a temperature between -50°C and 0°C, for example. These tanks can be installed on land or on a floating structure. In the case of a floating structure, the tank can be intended for the transport of liquefied gas or to receive liquefied gas used as fuel for the propulsion of the floating structure. In the case of a land-based tank or a port storage structure, it can rest on the ground or the seabed and can be partially or completely buried.

[0189] With reference to the, a cutaway view of a ship 70 shows a sealed and thermally insulating tank 71 of generally prismatic shape mounted in the double hull 72 of the ship. 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 ship, 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.

[0190] In a manner known per se, loading / unloading pipes 73 arranged on the upper deck of the ship can be connected, by means of appropriate connectors, to a maritime or port terminal to transfer a cargo of liquefied gas from or to the tank 71.

[0191] It also represents an example of a maritime terminal comprising a loading and unloading station 75, an underwater pipeline 76 and an onshore installation 77. The loading and unloading station 75 is a fixed offshore installation comprising a mobile arm 74 and a tower 78 which supports the mobile arm 74. The mobile arm 74 carries a bundle of insulated flexible pipes 79 which can be connected to the loading / unloading pipelines 73. The orientable mobile arm 74 adapts to all sizes of hydrogen carriers. A connecting pipe, not shown, extends inside the tower 78. The loading and unloading station 75 allows the hydrogen carrier 70 to be loaded and unloaded from or to the onshore installation 77. The latter comprises liquefied gas storage tanks 80 and connecting pipes 81 connected by the underwater pipe 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 installation 77 over a long distance, for example 5 km, which makes it possible to keep the hydrogen carrier vessel 70 at a great distance from the coast during loading and unloading operations.

[0192] To generate the pressure necessary for the transfer of the liquefied gas, it is possible either to use pumps on board the ship 70 and / or pumps fitted to the onshore installation 77 and / or pumps fitted to the loading and unloading station 75 or to allow a rise in pressure in the interior space of the tank under the effect of the evaporation of the liquefied gas stored in the tank.

[0193] The invention applies to ship tanks 71 and also to land tanks and port structures.

[0194] Although the invention has been described in connection with several particular embodiments, it is obvious that it is in no way limited thereto 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.

[0195] The use of the verb "comprise", "comprise" or "include" and its conjugated forms does not exclude the presence of other elements or other steps than those set out in a claim.

[0196] In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims

Wall (10) for a sealed and thermally insulating tank for storing a liquefied gas, the wall (10) successively comprising, in a thickness direction, a secondary thermally insulating barrier (12) which is intended to rest against a supporting structure (1), a secondary sealing membrane (13) which rests against the secondary thermally insulating barrier (12), a primary thermally insulating barrier (14) which rests against the secondary sealing membrane (13) and a primary sealing membrane (15) which rests against the primary thermally insulating barrier (14) and is intended to be in contact with the liquefied gas contained in the tank;the primary thermally insulating barrier (14) comprising a plurality of carrier elements (30) which are fixed to the secondary thermally insulating barrier (13) and which rise in the thickness direction (D), and a radiative multilayer insulation cover (47), which has openings (47A) through which the carrier elements (30) pass and which extends transversely to the thickness direction (D) of the wall, said multilayer insulation cover (47) being fixed to one of the carrier elements (30) by a fixing device (51; 52; 53; 54; 55) comprising a connecting part (511; 521; 531; 541; 551) fixed on said carrier element (30) and a support part (512; 522; 532; 542; 552) extending transversely to the thickness direction (D) of the wall (10), said insulation cover (47) being fixed on said support part (512; 522; 532; 542; 552), in which the connecting part (511; 521; 531; 541;551) of the fixing device (51; 52; 53; 54; 55) comprises two portions (511A, 511B; 521A, 521B; 531A, 531B; 541A, 541B; 551A, 551B) movable relative to each other between a spaced position in which the two portions (511A, 511B; 521A, 521B; 531A, 531B; 541A, 541B; 551A, 551B) are spaced apart from each other to allow the carrier element (30) to be placed through the fixing device (51; 52; 53; 54; 55) so that the fixing device surrounds the carrier element (30) and a bringing together position in which the two portions (511A, 511B; 521A, 521B; 531A, 531B; 541A, 541B; 551A, 551B) are brought together relative to the separating position, so as to be able to immobilize the fixing device on the carrier element by clamping the carrier element.; Wall according to claim 1, wherein the fixing device (51; 52; 53; 54; 55) is immobilized on the carrier element by gluing the fixing device (51; 52; 53; 54; 55) to the carrier element (30) and / or by elastic clamping of the carrier element (51; 52; 53; 54; 55) by the fixing device and / or by axial locking of the fixing element (51; 52; 53; 54; 55) which rests on at least one stop element of the carrier element (30) extending projecting from the carrier element (30). Wall according to one of claims 1 and 2, in which said carrier element (30) has a central part of tubular shape and the two portions (511A, 511B; 521A, 521B; 531A, 531B; 541A, 541B; 551A, 551B) of the connecting part (511; 521; 531; 541; 551) of the fixing device (51; 52; 53; 54; 55) form in their approach position a collar whose internal dimensions are equal, to within a clearance, to the external dimensions of the central part of the carrier element (30). Wall according to one of claims 1 to 3, in which the connecting part (511; 521; 531) and the support part (512; 522; 532) of the fixing device (51; 52; 53) are produced by one or more metal plates. Wall according to one of claims 1 to 4, in which the two portions (511A, 511B) of the connecting part (511) are connected by at least one hinge. Wall according to one of claims 1 to 4, in which the two portions (521A, 521B) of the connecting part (521) are connected by at least one staple (529). Wall according to one of claims 1 to 3, in which the two portions (541A, 541B; 551A, 551B) of the connecting part (541; 551) belong to a metal spring wire or to a metal spring blade. Wall according to claim 7, in which said spring wire or said spring blade forms a single turn or a plurality of turns around the supporting element (30). Wall according to one of claims 7 and 8, in which the connecting part (551) of the fixing device (55) is formed by a spring wire which has ends folded and nested one inside the other so as to be able to move elastically away from one another. Wall according to one of claims 1 to 9, in which the support part (512; 522; 532; 542; 552) of the fixing device comprises at least one tab (512A; 522A; 532A; 542A; 552A) extending projecting from the connecting part (511; 521; 531; 541; 551). Wall according to claim 10, in which the tab (512A; 532A) is formed or is attached to said connecting part of the fixing device. Wall according to claim 11, in which the two portions (541A, 541: 551A, 551B) of the connecting part (541; 551) belong to a metal spring wire and the tab (542A; 552A) is formed by a fold of the wire or the spring blade. Wall according to claim 11, in which the tab (512A, 522A) is formed by folding a metal plate (513; 523) forming one of the two portions of the connecting part (511; 521). Wall according to claim 11, in which the tab (532A) is formed by welding a metal plate onto one of the two portions of the connecting part (531). Wall according to one of claims 1 to 14, in which the support part (512; 522; 532; 542; 552) of the fixing device (51; 52; 53; 54; 55) comprises a fixing element (518; 528; 538; 548; 558) of the multilayer insulation cover (47) adapted to cooperate with a complementary fixing element (560) of the fixing device. Wall according to claim 15, in which the fixing element of the multi-layer insulation cover is an orifice, the complementary fixing element of the fixing device comprises a fir-tree clip, a pin or a rivet and the multi-layer insulation cover comprises an opening located opposite this through orifice of the fixing element which is crossed by the fir-tree clip, the pin or the rivet. A sealed and thermally insulating tank intended to be fixed to a supporting structure, the supporting structure comprising a plurality of supporting walls, the tank comprising a plurality of tank walls intended to be fixed each time to a respective supporting wall, including a tank wall according to one of claims 1 to 16. A vessel (70) for transporting a fluid, the vessel comprising a double hull (72) and a tank (71) according to claim 17 disposed in the double hull (72). A transfer system for a liquefied gas, the system comprising a vessel (70) according to claim 18 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). A method of loading or unloading a ship (70) according to claim 18, wherein a liquefied gas is conveyed through insulated pipes (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).

Images