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

Abstract

The invention relates to a wall for a sealed and thermally insulating tank for storing a liquefied gas, the wall comprising a thermally insulating barrier (14) comprising: - a first support element (61) and a second support element (62, - a connecting device (47), positioned between a sealing membrane (15) and a supporting structure (1), the connecting device (47) having a first end connected to the first support element (61) and a second end connected to the second support element, said connecting device (47) being configured so that, considered in isolation from the first support element (61) and the second support element (62) in a state free to contract,a rectilinear distance d between the first end and the second end varies by less than 5% during a temperature variation Δt between a temperature of 20°C and a temperature to which said connecting device (47) is intended to be subjected when the tank is loaded with liquefied gas. Figure to be published: 4,

Description

Title of the invention: Wall for a sealed and thermally insulating tank for storing liquefied gas Technical field

[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 liquefied natural gas (LNG), which is stored, at atmospheric pressure, at approximately -162°C or liquid hydrogen which is stored at approximately -253°C at atmospheric pressure. Technological background

[0002] In the state of the art, sealed and thermally insulating tanks for storing liquefied gas are known.

[0003] Document EP2859267 discloses a tank in which the walls have a multi-layer structure, i.e. successively have, in the direction of thickness of the wall, from the outside to the inside, a secondary thermally insulating barrier retained on the supporting structure, a secondary sealing membrane resting against the secondary thermally insulating barrier, a primary thermally insulating barrier resting against the secondary sealing membrane and a primary sealing membrane intended to be in contact with the liquefied natural gas contained in the tank.

[0004] The primary thermally insulating barrier comprises a plurality of heat-insulating elements, each of which comprises a rectangular or square-shaped cover panel and a plurality of supporting pillars fixed to a lower face of the cover panel, perpendicular thereto. The thermally insulating barrier also comprises a frame which is formed by crosspieces and which surrounds the cover panel. Each crosspiece is equipped with an anchor plate which also rests in a counterbore provided in the cover wall.

[0005] The primary waterproofing membrane has a network of perpendicular corrugations to give it elasticity in all directions of the plane. It is constructed from rectangular sheet metal plates which are overlap-welded along their edges. In addition, the sheet metal plates are placed on the cover panels and their edges are welded to the anchor plates fitted to the crosspieces forming the frame.

[0006] Therefore, in a tank of the aforementioned type, each cover panel is fixed to a plurality of supporting pillars and supports a plurality of flat areas of the sealing membrane. Insofar as it provides a connection between a plurality of pillars load-bearing pillars, each cover panel allows the forces exerted on several load-bearing pillars to be distributed, which allows the support function of the primary waterproofing membrane to continue to be satisfactorily ensured even when one of the load-bearing pillars breaks. However, such an arrangement leads in return to non-uniformly stressing the primary waterproofing membrane. In particular, since each cover panel supports a plurality of flat areas of the primary waterproofing membrane, the behavior of the thermally insulating barrier is not uniform when the load-bearing structure deforms and / or under the effect of the thermal and mechanical stresses generated by the liquefied gas stored in the tank. In particular, certain corrugations deform more than others in order to compensate for displacements greater than those to which the other corrugations are exposed.In addition, the flat surfaces of the primary waterproofing membrane rub against the cover panels of the heat-insulating elements, which also affects the uniformity of stress distribution. However, it is important to ensure the most uniform possible distribution of stresses in the primary waterproofing membrane, particularly with a view to optimizing its service life. This disadvantage is all the more critical when the storage temperature of the liquefied gas is low and, consequently, the thermal stresses exerted on the primary waterproofing membrane are significant. Summary

[0007] An idea underlying the invention is therefore to resolve the aforementioned drawbacks by proposing a sealed and thermally insulating tank wall whose thermally insulating barrier has support elements for the sealing membrane which are connected to each other by connecting devices and in which said connecting devices make it possible to distribute the forces between the support elements and this while having little or no effect on the homogeneity of the stresses exerted on the sealing membrane.

[0008] According to one embodiment, the invention provides a wall for a sealed and thermally insulating tank for storing a liquefied gas, the wall successively comprising, along a thickness direction of the wall, a thermally insulating barrier intended to be anchored to a supporting structure and a sealing membrane which rests against the thermally insulating barrier and is intended to be in contact with the liquefied gas stored in the sealed and thermally insulating tank, the thermally insulating barrier comprising: - a first support element and a second support element, the waterproofing membrane comprising a first zone resting on the first support element and a second zone resting on the second support element, - a connecting device, positioned between the waterproofing membrane and the structure carrier, and connecting the first support element to the second support element such that a force exerted on the first area is transmitted from the first support element to the second support element through the connecting device; the connecting device having a first end connected to the first support element and a second end connected to the second support element.

[0009] Thus, the connecting devices make it possible to distribute the forces between the first and second support elements, which makes it possible to continue to provide support for the waterproofing membrane even in the event of deterioration of one of the two support elements.

[0010] According to one embodiment, the connecting device is configured so that, considered in isolation from the first support element and the second support element in a state free to contract, a rectilinear distance d between the first end and the second end varies by less than 5% during a temperature variation At between a temperature of 20°C and a temperature to which said connecting device is intended to be subjected when the tank is loaded with liquefied gas.

[0011] For the purposes of this document, the expression "considered in isolation" means that the characteristic relating to the variation in rectilinear distance between the two ends of the connecting device is not tested in the normal configuration of the connecting device in which its ends are fixed to the supporting elements but while the connecting device is in a state free to contract or expand, that is to say without its two ends being fixed to the supporting elements. This characteristic can thus be tested by separating the connecting device from the supporting elements and subjecting it to the temperature variation At.

[0012] Thus, the connecting devices generate little or no stress on the support elements when the tank is cooled. They therefore have little or no effect on the homogeneity of the stresses exerted on the sealing membrane.

[0013] According to embodiments, such a wall may comprise one or more of the following characteristics.

[0014] According to one embodiment, the connecting device is configured so that, considered in isolation from the first support element and the second support element in a state free to contract, a rectilinear distance d between the first end and the second end varies by less than 5% during a temperature variation At between a temperature of 20°C and a temperature between -120°C and -253°C.

[0015] According to one embodiment, the connecting device comprises: - a mechanical connection comprising a first end connected to the first support element and a second end connected to the second support element; and - a contraction compensator which cooperates with the mechanical connection in such a way that a thermal contraction of said contraction compensator has the following effects: effect of compensating for stresses tending to bring the first end and the second end of the mechanical connection closer together during thermal contraction of said mechanical connection.

[0016] According to one embodiment, the mechanical connection comprises a connection blade which is curved and which has a concave face and the contraction compensator comprises a compensation blade which is fixed against the concave face of the connection blade so as to form with the connection blade a bimetallic strip, the compensation blade having a coefficient of thermal expansion which is lower than a coefficient of thermal expansion of the connection blade.

[0017] Thus, the bimetallic strip deforms with temperature variations: it straightens when its temperature decreases and curves when its temperature increases, which makes it possible to at least partially compensate for the variation in length of the bimetallic strip during its contraction and expansion.

[0018] According to one embodiment, the bimetallic strip is arranged so that, considered in isolation from the rest of the thermally insulating barrier, the rectilinear distance between the first end and the second end of the mechanical connection varies by less than 5% during a temperature variation At between a temperature of 20°C and a temperature to which said bimetallic strip is intended to be subjected when the tank is loaded with liquefied gas.

[0019] According to one embodiment, the temperature to which the bimetallic strip is intended to be subjected when the tank is loaded with liquefied gas is 10 to 40°C higher than the storage temperature of the liquefied gas at atmospheric pressure, namely -162°C for liquefied natural gas and -253°C for liquid hydrogen. It should be noted that such a system could perfectly well be implemented at said liquid temperature or above 40°C warmer.

[0020] According to one embodiment, the bimetallic strip has a radius of curvature in a plane orthogonal to the thickness direction of the wall.

[0021] According to one embodiment, the first end and the second end of the mechanical connection are respectively mounted articulated on the first support element and the second support element by means of a pivot connection having a degree of freedom in rotation around an axis parallel to the direction of thickness of the wall.

[0022] According to one embodiment, the first end and the second end of the mechanical connection are respectively fixed, in particular by welding or by bolting, on a fixing tab projecting radially from the first support element and the second support element.

[0023] According to one embodiment, the bimetallic strip has two ends and a central part, the ends of the bimetallic strip having a radius of curvature greater than that of the central part. This makes it possible in particular to limit, or even eliminate, the rotation effect of said ends under the effect of a variation in temperature; which makes it possible to limit or eliminate the constraints in the fixing zones of the ends of the bimetallic strips, in particular when they are not mounted articulated by means of a pivot connection.

[0024] According to another embodiment, the mechanical connection comprises successively, from the first end towards the second end, at least a first connection section and a second connection section which are linked to each other by the contraction compensator, the first connection section being fixed to the contraction compensator in a first fixing zone and the second connection section being fixed to the contraction compensator in a second fixing zone, the first fixing zone being positioned along the connecting device between the second fixing zone and one end of the second connection section intended to be fixed to the second support element.

[0025] Thus, the contraction of the traction compensator has the effect of generating on the two connection sections traction forces which oppose the contraction of said connection sections, which makes it possible to at least partially compensate for the thermal stresses tending to bring the ends of the connection device closer together.

[0026] According to one embodiment: - the first connection section has a length Ll, measured at 20°C, between the first end and the first fixing zone and is made of a material having a coefficient of thermal expansion oq at 20°C, - the second connection section has a length L2, measured at 20°C, between the second end and the first fixing zone and is made of a material having a thermal expansion coefficient a2 at 20°C, - the contraction compensator has a length L3 measured at 20°C, between the first fixing zone and the second fixing zone and is made of a material having a thermal expansion coefficient a3 at 20°C; Ll, L2, L3, oq, a2 and a3 satisfying the following inequality: Ll * eu + L2 * a2- L3 * a3< 0.05 * (L1+L2 - 2*L3).

[0027] According to an alternative embodiment, the first connection section, the second connection section and the contraction compensator each have the shape of a flat blade.

[0028] According to another embodiment variant, the first connection section, the second connection section and the contraction compensator each have a tubular shape.

[0029] According to one embodiment, the connecting device is made of a composite material comprising a resin and carbon fibers and having a coefficient thermal expansion less than 3 x 106°K

[0030] According to one embodiment, the first support element and the second support element each comprise a carrier element which extends in the thickness direction of the wall and an internal plate which is fixed to said carrier element and against which the first zone or the second zone of the waterproofing membrane rests.

[0031] According to one embodiment, the carrier element comprises an external base, an internal base fixed to the internal plate and a pillar extending between the external base and the internal base.

[0032] According to one embodiment, the first end and the second end of the mechanical connection are respectively linked to the internal base of the first support element and the second support element.

[0033] According to one embodiment, the thermally insulating barrier comprises a third support element aligned with the first support element and the second support element in a first direction, a third zone of the sealing membrane resting on the third support element, the third support element being connected to the second support element by a second connecting device.

[0034] According to one embodiment, the thermally insulating barrier comprises a fourth support element and a fifth support element aligned with the second support element in a second direction perpendicular to the first direction, a fourth zone of the sealing membrane resting on the fourth support element, a fifth zone of the sealing membrane resting on the fifth support element, the fourth support element and the fifth support elements being respectively connected to the second support element by a third and a fourth connecting device.

[0035] According to one embodiment, the first zone of the sealing membrane is fixed, for example welded, to the first support element and the second zone of the sealing membrane is fixed, for example welded, to the second support element.

[0036] According to one embodiment, the 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 first and second zones of the sealing membrane each being defined between two adjacent first corrugations and between two adjacent second corrugations.

[0037] According to one embodiment, the first flat zone and the second flat zone are separated from each other by a second corrugation which is arranged opposite, in the thickness direction, a free space separating the first and second support elements.

[0038] According to one embodiment, the internal plate is fixed to the supporting element by riveting.

[0039] According to one embodiment, the internal plate of the first and second support elements are respectively in contact against more than 70%, and advantageously between 90 and 100%, of the surface of the first and second zones. This makes it possible to distribute the forces due to the hydrostatic and dynamic pressures exerted by the liquefied gas on the sealing membrane over a larger support surface, thus contributing to a better distribution of the stresses.

[0040] According to one embodiment, the first and second zones are respectively welded against the internal plate of the first and second support elements.

[0041] According to one embodiment, the waterproofing membrane comprises a plurality of corrugated metal sheets, each corrugated metal sheet having edges which are each lap welded to an edge of an adjacent corrugated metal sheet, the first and second zones being formed by two edges of two adjacent corrugated metal sheets. In other words, the first, second and third internal plates support and anchor the two adjacent edges of two adjacent corrugated metal sheets.

[0042] According to one embodiment, each of the external and internal bases has a sleeve cooperating by fitting with one of the ends of the pillar and a support collar extending radially from one end of the sleeve.

[0043] According to one embodiment, each end of the pillars is fitted inside one of the sleeves. According to another variant, each sleeve is fitted inside one of the ends of one of the pillars. According to another embodiment, the pillar, the external base and the internal base are formed in one piece.

[0044] According to one embodiment, the support collar of the internal base is supported and fixed against the internal plate.

[0045] According to one embodiment, the support collar of the external base is supported and fixed against the external plate.

[0046] According to one embodiment, each pillar is fixed, for example by gluing, to the internal base and to the external base.

[0047] According to one embodiment, each pillar is made from a composite material comprising fibers and a matrix, which makes it possible to obtain satisfactory compressive strength for a limited conductive section.

[0048] According to one embodiment, the fibers are chosen from glass fibers, carbon fibers, aramid fibers, flax fibers, basalt fibers and mixtures thereof.

[0049] According to one embodiment, the matrix is ​​chosen from polyethylene, poly- propylene, polyethylene terephthalate, polyamide, polyoxymethylene, polyetherimide, polyacrylate, polyaryletherketone, polyetheretherketone, copolymers thereof, polyester, vinylester, epoxy and polyurethane.

[0050] According to a preferred embodiment, the pillars are made of an epoxy resin reinforced with glass fibers.

[0051] According to one embodiment, each pillar has a tubular section.

[0052] According to one embodiment, each pillar has one or more orifices tra slopes and opening into an internal space of said pillar.

[0053] According to one embodiment, the primary thermally insulating barrier has a gas phase at an absolute pressure of less than 1 Pa, advantageously less than 10 1 Pa, preferably less than 10 2 Pa and for example of the order of 102 Pa. This makes it possible to increase the thermal insulation performance of the primary thermally insulating barrier.

[0054] According to one embodiment, the sealing membrane is a primary sealing membrane and the thermally insulating barrier is a primary thermally insulating barrier, the tank wall further comprising a secondary thermally insulating barrier which rests against a supporting structure and a secondary sealing membrane positioned between the secondary thermally insulating barrier and the primary thermally insulating barrier.

[0055] According to one embodiment, the invention also relates to a sealed and thermally insulating tank comprising a plurality of walls of the aforementioned type.

[0056] In one embodiment, the liquefied gas is liquid hydrogen.

[0057] The tank can be made using different techniques, in particular in the form of an integrated membrane tank.

[0058] Such a tank may be part of a land-based storage facility or installed in a floating, coastal or deep-water structure, including a liquid hydrogen transport vessel, i.e., a hydrogenerator, a floating storage and regasification unit (FSRU), a floating production and remote storage unit (FPSO) and others. Such a tank may also serve as a fuel tank in any type of vessel.

[0059] According to one embodiment, a ship for transporting a liquefied gas comprises a double hull and a aforementioned tank arranged in the double hull.

[0060] According to one embodiment, the invention also provides a transfer system for a liquefied gas, the system comprising the aforementioned vessel and insulated pipes arranged so as to connect the tank installed in the hull of the vessel to a floating or land-based storage installation.

[0061] According to one embodiment, the transfer system also comprises a pump for driving a flow of liquefied gas through the insulated pipes from or to the floating or land-based storage facility to or from the ship's tank.

[0062] According to one embodiment, the invention also provides a method for loading or unloading such a ship, in which a liquefied gas is conveyed through insulated pipes from or to a floating or land-based storage facility to or from the tank of the ship. Brief description of the figures

[0063] The invention will be better understood, and other aims, 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 appended drawings.

[0064] [Fig-1] [Fig.l] is a cutaway and schematic perspective view of a structure carrier intended to support a sealed and thermally insulating tank for storing liquefied gas.

[0065] [Fig.2] [Fig.2] is a partial perspective view of a wall of a watertight tank and thermally insulating according to a first embodiment.

[0066] [Fig.3] [Fig.3] is a partial sectional view of the thermally secondary insulation of the wall of [Fig.2], partially illustrating an anchoring device intended to ensure the fixing of a load-bearing element of the primary thermally insulating barrier on the secondary thermally insulating barrier.

[0067] [Fig.4] [Fig.4] is a schematic sectional view of the thermally primary insulating membrane and primary waterproofing membrane of the wall of the [Fig.2].

[0068] [Fig.5] [Fig.5] is a schematic view, from above, illustrating the load-bearing elements as well as connecting devices connecting the supporting elements to each other, according to a first embodiment.

[0069] [Fig.6] [Fig.6] is a schematic view illustrating the geometry of one of the devices connection of [Fig.5] in two states: when it is at room temperature and when the tank is cooled.

[0070] [Fig.7] [Fig.7] is a view similar to that of [Fig.5] illustrating devices connecting element connecting the load-bearing elements according to a second embodiment.

[0071] [Fig.8] [Fig.8] is a view similar to that of Figures 5 and 7 illustrating connecting devices connecting the load-bearing elements according to a third embodiment.

[0072] [Fig.9] [Fig.9] is a view similar to that of Figures 5, 7 and 8 illustrating dis positive bonding elements bonding the carrier elements according to a fourth embodiment.

[0073] [Fig. 10] [Fig. 10] is a schematic view of the connecting devices connecting the load-bearing elements according to a fifth embodiment.

[0074] [Fig. 11] [Fig. 11] is a perspective view of a connecting device for connecting load-bearing elements according to a sixth embodiment.

[0075] [Fig.12] [Fig.12] is a top view of the connecting device of [Fig.11].

[0076] [Fig. 13] [Fig. 13] is a partial sectional view of a connecting device intended to connecting load-bearing elements according to a seventh embodiment.

[0077] [Fig. 14] [Fig. 14] is a schematic cutaway representation of a tank of a ship and a loading / unloading terminal for this tank.

[0078] [Fig. 15] [Fig. 15] is a schematic top view of a connecting device intended to connect load-bearing elements according to an eighth embodiment. Description of the embodiments

[0079] By convention, the terms "external" and "internal" are used to define the relative position of one element with respect to another, with reference to the inside and outside of the tank.

[0080] 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. The liquefied gas may also be a liquefied natural gas (LNG) - that is to say a gaseous mixture comprising mainly methane as well as one or more other hydrocarbons - ethane, a liquefied petroleum gas (LPG) - that is to say a mixture of hydrocarbons resulting from the refining of petroleum comprising essentially propane and butane - or liquid ammonia.

[0081] [Fig.l] illustrates a supporting structure 1 against which a sealed and thermally insulating tank for storing a liquefied gas is intended to be fixed.

[0082] The supporting structure 1 may in particular be formed from self-supporting metal sheets or, more generally, from any type of rigid partition having appropriate mechanical properties. The supporting structure 1 is, for example, formed by the double hull of a ship. In [Fig.l], the supporting structure 1 has a generally polyhedral shape. It has two front and rear load-bearing walls 2, here octagonal in shape, of which only the rear load-bearing wall 2 is shown. The front and rear walls 2 are, for example, cofferdam walls of the ship which extend transversely to the longitudinal direction of the ship. The supporting structure 1 also comprises an upper load-bearing wall 3, a lower load-bearing wall 4 and side load-bearing walls 5, 6, 7, 8, 9, 10.

[0083] In relation to [Fig.2], a wall 11 of a sealed and thermally insulating tank according to a first embodiment is described below. 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, 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.

[0084] The secondary thermally insulating barrier 12 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 onto 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, contributing to reducing its thermal contraction.

[0085] 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. Each secondary anchoring device comprises a stud welded to the supporting structure 1 as well as a support member which is fixed on the stud and which bears against a support zone of the insulating panels 16. According to one embodiment, the external plate 19 of the insulating panels 16 projects beyond 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.Elastic members, such as Belleville washers, are advantageously threaded onto the stud, between a nut mounted on the stud and the support member, which makes it possible to ensure elastic anchoring of the insulating panels 16 on the supporting structure 1.

[0086] Advantageously, 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 alternative 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.

[0087] 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 21 ensuring functional assembly clearance. The gaps 21 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 can also be filled with insulating plugs, as described in applications WO2019155157 or WO2021028624 for example.

[0088] In the embodiment shown, the internal 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 the corrugated metal sheets 25 of the secondary sealing membrane 13. 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 internal plate 10 as well as an internal 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 sealing membrane 13.

[0089] Furthermore, the inner plate 18 of the insulating panels 16 is equipped with metal plates 26 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 26 extend in two perpendicular directions which are each parallel to 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 26 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.

[0090] 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 sealing membrane 13. Advantageously, the insulating panels 16 have relaxation slots 27 at least opposite each of the corrugations 24 of the secondary sealing membrane 13.

[0091] The secondary sealing membrane 13 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 1.2.106 and 2.106 K ', or in an iron alloy with a high manganese content whose coefficient of expansion is typically of the order of 7.106 K1. Alternatively, the corrugated metal sheets 25 can also be made of stainless steel or aluminum.

[0092] The corrugated metal sheets 25 are overlap-welded along their edges in order to ensure the sealing of the secondary sealing 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 so 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 welds.

[0093] The secondary sealing membrane 13 has corrugations 24 and more particularly a first and a second series of corrugations which 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.

[0094] 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 and in the interstices 21 formed between the adjacent insulating panels 16.

[0095] Furthermore, the flat areas 28 of the secondary sealing membrane 13 are each crossed by a primary anchoring device 29, illustrated in detail in [Fig. 3], and 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 29 comprises a stud 31 which passes through the secondary sealing membrane 13. The stud 31 has an external end which is fixed to one of the insulating panels 16. To do this, in the embodiment shown, the external end of each stud 31 is threaded and is screwed into a threaded sleeve 32 which is fixed inside a bore made in the internal plate 18 of one of the insulating panels 16. Furthermore, the stud 31 comprises a collar 33 developing radially relative to the axis of the stud 31.

[0096] The collar 33 is welded in a sealed manner to the secondary sealing membrane 13 around the orifice of said secondary sealing membrane 13 crossed by the stud 31 in order to maintain the sealed nature of the secondary sealing membrane 13.

[0097] Furthermore, an external plate 34, also illustrated in [Fig. 3], has an orifice crossed by the stud 31. The primary anchoring device 29 comprises a nut 35 which is screwed onto an internal threaded end of the stud 31 and which thus makes it possible to hold the external plate 34 against the flat zone 28 opposite the secondary sealing membrane 13. The external plates 34 have a dual function. On the one hand, they make it possible to press the secondary sealing 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 thermally insulating barrier. secondary insulating barrier 12 with respect 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.

[0098] 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.

[0099] 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.

[0100] Returning to [Fig. 2], it can be seen that the primary thermally insulating barrier 14 comprises a plurality of support elements 61, 62 which each comprise a carrier element 30 which extends in the direction of thickness of the wall 11 and an internal plate 42, not visible in [Fig. 2] but visible in [Fig. 4], which is fixed to said carrier element 30. The support elements 61, 62 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 carrier elements 30 are aligned in rows which are parallel or perpendicular to the directions of the corrugations of the first series and the second series of corrugations of the secondary sealing membrane 13.

[0101] As shown in [Fig.4], 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 which is fitted with one of the ends of the pillar 38 and a support collar 40 which extends radially from one end of the sleeve 39. 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. According to another embodiment, the pillar 38 as well as the external base 36 and the internal base 37 are formed in one piece, by molding for example.

[0102] The pillars 38 have a tubular shape, preferably with a circular section. 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, polyethylene 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.

[0103] The pillars 38 are advantageously provided with through-orifices, not illustrated, 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.

[0104] The support collar 40 of each external base 36 is fixed on an external plate 34, illustrated in [Fig.3], for example by riveting.

[0105] 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 fixed to the internal plate 42, for example by riveting.

[0106] The support elements 61, 62 thus form discrete support structures which each support a flat area 46, 63, 64 of the primary sealing membrane 15, which allows good distribution of the stresses between the corrugations 45 of the primary sealing membrane 15.

[0107] Returning to [Fig.2], we observe the primary sealing membrane 15 which is also obtained by assembling a plurality of corrugated metal sheets 44. The corrugated metal sheets 44 each have a substantially rectangular shape. The corrugated metal sheets 44 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 2.106 K ', or in an iron alloy with a high manganese content whose coefficient of expansion is typically of the order of 7.106 K1. Alternatively, the corrugated metal sheets 44 can also be made of stainless steel or aluminum.

[0108] The corrugated metal sheets 44 are overlap welded along their edges in order to ensure the sealing of the primary sealing membrane 15. The primary sealing membrane 15 comprises corrugations 45. More particularly, it comprises a first series of corrugations 45a extending parallel to a first direction and a second series of corrugations 45b extending parallel to a second direction. The directions of the series of corrugations 45a, 45b are perpendicular and are parallel or perpendicular to the rows of load-bearing elements 30. Each of the series of corrugations 45a, 45b is parallel to two opposite edges of the corrugated metal sheets 44. 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 44 comprises, between the corrugations 45, a plurality of flat areas 46.

[0109] The pitch of the corrugations 24 of the secondary sealing membrane 13 is equal to the pitch of the corrugations 45 of the primary sealing membrane 15 or to an integer multiple thereof. In addition, each of the corrugations 24 of the secondary sealing membrane 13 is arranged opposite, in the thickness direction of the wall 11, a corrugation 45 of the primary sealing membrane 15. Thus, each flat zone 46 of the primary sealing membrane 15 is located opposite, in the thickness direction of the wall 11, a flat zone 28 of the secondary sealing membrane 13. Therefore, the axis of each supporting element 30 passes both through the center of a flat zone 46 of the primary sealing membrane 15 and through the center of a flat zone 28 of the secondary sealing membrane 13.

[0110] 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.

[0111] The corrugated metal sheets 44 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 44 are welded to the internal plates 42, for example by spot welds. According to an advantageous embodiment, the corrugated metal sheets 44 are also anchored to internal plates 42 outside their edge areas. To do this, the corrugated metal sheets 44 can in particular be welded to the internal plates 42 by transparency welds. According to an advantageous embodiment, the corrugated metal sheets 44 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.

[0112] Furthermore, the primary thermally insulating barrier 14 has a gaseous phase which is under depression, i.e. has an absolute pressure lower than atmospheric pressure, in order to give the primary thermally insulating barrier 14 the required thermally insulating properties. The gaseous phase of the barrier The primary thermally insulating barrier 14 is advantageously placed at an absolute pressure of less than 1 Pa, advantageously less than 10 1 Pa, preferably less than 10 2 Pa, and for example of the order of 103 Pa. To do this, the primary thermally insulating barrier 14 is advantageously connected to a vacuum pump.

[0113] Furthermore, the supporting elements 30 are connected to each other by connecting devices 47. The connecting devices 47 thus make it possible to distribute the forces exerted on the primary waterproofing membrane 15 between the supporting elements 30. This also limits the risks of a supporting element 30 tipping over and also makes it possible to continue to ensure satisfactory support of the primary waterproofing membrane 15 even when one of the supporting elements 30 is damaged.

[0114] In the embodiments described below, the connecting devices 47 extend in a plane orthogonal to the direction of thickness of the wall. In the embodiments illustrated in FIGS. 3 to 13, the connecting devices 47 comprise a mechanical connection which connects two supporting elements 30 to each other and a contraction compensator intended to compensate at least in part for the stresses tending to bring the ends of the mechanical connection closer together when the latter contracts, during the cooling of the tank.

[0115] According to an advantageous embodiment, the connecting devices 47 are fixed to the internal base 37 of the two adjacent supporting elements 30. Thus, the support of the primary sealing membrane 15 can continue to be ensured even when one of the pillars 38 tilts or breaks. In this respect, the arrangement of the connecting devices 47, described above, i.e. with a contraction compensator, is particularly advantageous in that it allows the connecting devices 47 to be positioned as close as possible to the primary sealing membrane 15, i.e. in the coldest zone of the primary thermally insulating barrier 14, without however generating excessive stresses, or even without generating stresses at all on the supporting elements 30 when the tank is cooled.

[0116] In the first embodiment shown in the figures, the connecting device 47 is a bimetallic strip 48, that is to say it comprises two strips 49, 50 welded to each other and made of materials having different coefficients of thermal expansion. The bimetallic strip 48 is curved with a radius of curvature oriented in a plane orthogonal to the thickness direction of the wall. The strip which is made of the material having the highest coefficient of thermal expansion is designated, by convention, the connecting strip and referenced 49 in the figures. The strip which is made of the material having the lowest coefficient of thermal expansion is designated, by convention, the compensation strip and referenced 50 in the figures. The compensation blade 50 is fixed against the concave face of the connection blade 49. In other words, the radius of curvature of the connection blade 49 is slightly greater than that of the compensation 50.

[0117] As shown in [Fig.6], the thermal expansion coefficients of the connecting strip 49 and the compensation strip 50 being different, the bimetallic strip 48 deforms with the temperature variations. Thus, the upper portion of [Fig.6] represents the shape of the bimetallic strip 48 at normal temperature (20°C), that is to say before the tank is cooled, while the lower portion represents the shape of the bimetallic strip 48 when the tank has been loaded with liquefied gas. The characteristics of the bimetallic strip 48 are such that the shape of the bimetallic strip 48 straightens when its temperature decreases, in order to compensate for the retraction of the bimetallic strip 48, and conversely curves when its temperature increases, in order to compensate for the expansion of the bimetallic strip 48.

[0118] Advantageously, the characteristics of the bimetallic strip 48 are chosen so that, considered in isolation from the other elements of the primary thermally insulating barrier 14, in a state free to deform, that is to say considered in isolation, before its ends are fixed to the supporting elements 30, the rectilinear distance d between its two ends varies by less than 5% during a variation in temperature At between the ambient temperature and the temperature to which it is subjected when the tank is loaded with liquefied gas.

[0119] To do this, the person skilled in the art, on the basis of his general knowledge, is able to determine the materials as well as the thicknesses e1, e2 of the connection blade 49 and of the compensation blade 50 as well as the radius of curvature of the bimetallic strip 48 as a function of the temperature variation At so that the variation in the rectilinear distance d is kept less than 5%.

[0120] According to an exemplary embodiment, the bimetallic strip 48 has the following characteristics: - the connection strip 49 has a thickness el of 2 mm and is made of 316 stainless steel which has a thermal expansion coefficient of approximately 17 x 106 ° K 1 at 20 °C; - the compensation blade 50 has a thickness of 0.8 mm and is made of high manganese steel which has a coefficient of thermal expansion of approximately 17 x 106 ° K1 at 20 °C; - the radius of curvature of the neutral fiber of the bimetallic strip 48 is 600 m at 20°C; and - the rectilinear distance d between the two ends is 280 mm.

[0121] Obviously, such a bimetallic strip 48 constitutes only an example of embodiment and those skilled in the art will be able to envisage any other bimetallic strip having different characteristics.

[0122] In the embodiment shown, each end of the bimetallic strip 48 is fixed by welding to a fixing tab 51 projecting from the internal base 37, radially relative to the axis of the carrier element 30. Alternatively, the ends of the bimetallic strips 48 can also be fixed by bolting to the fixing tabs 51.

[0123] In another embodiment not shown, each end of the bimetallic strip 48 is mounted articulated on one of the supporting elements 30, for example on a fixing tab 51 as described above, by means of a pivot connection having a degree of freedom in rotation about an axis parallel to the direction of thickness of the wall. This avoids generating stresses in the areas of fixing of the ends of the bimetallic strip 48 to the supporting elements 30 taking into account the rotation of said ends when the shape of the bimetallic strip 48 straightens or curves due to a variation in temperature.

[0124] In the configuration partially illustrated in [Fig.5], each carrier element 30 is connected by a connecting device 47, as described above, to the four adjacent carrier elements 30: two of the four carrier elements 30 being aligned in a first direction with said carrier element 30 and the other two carrier elements 30 being aligned in a second direction perpendicular to the first.

[0125] It is also observed that the concavity of the four bimetallic strips 48 which are fixed to the same carrier element 30 have the same orientation, around the central axis of the carrier element 30. In other words, the bimetallic strips 48 are symmetrical two by two with respect to the central axis of the carrier element 30. Thus, the fixing tabs 51 can be equally distributed around the axis of the carrier element 30.

[0126] [Fig. 7] illustrates connecting devices 47 according to a second embodiment. These connecting devices 47 differ from those described above in relation to [Fig. 5] in that their radius of curvature is smaller, which means that the thermal expansion coefficients of the materials constituting the connecting blade and the compensation blade are lower than those of the bimetallic strips 48 illustrated in [Fig. 5].

[0127] [Fig. 8] illustrates connecting devices 47 according to a third embodiment. This embodiment differs from those described in relation to FIGS. 5 and 7 only in that each carrier element 30 is connected by a connecting device 47 of the aforementioned type only to two carrier elements 30, the connecting devices 47 ensuring the connection only between the adjacent carrier elements 30 according to one of the two directions of alignment of the carrier elements 30. This makes it possible in particular to limit the cost and complexity of the tank, by limiting the number of connecting devices 47.

[0128] [Fig. 9] illustrates connecting devices 47 according to a fourth embodiment. This embodiment differs from those described previously in that the radius of curvature of the bimetallic strips 48 is not constant. Thus, in the embodiment shown, the ends 52 of the bimetallic strips 48 have a radius of curvature greater than that of their central part 53. According to an alternative embodiment, the radius of curvature of the ends 52 of the bimetallic strips 48 is infinite. In other words, the ends 52 of the bimetallic strips 48 are rectilinear. This makes it possible to limit, or even eliminate, the effect of rotation of said ends 52 under the effect of a variation in temperature; which makes it possible to limit or eliminate the stresses in the fixing zones of the ends 52 of the bimetallic strips 48. This also makes it possible to simplify the positioning of the fixing tabs 51 since they can thus be aligned with the alignment directions of the supporting elements 30.

[0129] [Fig. 10] illustrates connecting devices 47 according to a fifth embodiment. As in the previous embodiment, described in relation to [Fig. 9], the ends 52 of the bimetallic strips 48 have a radius of curvature greater than that of their central part 53. However, this embodiment further differs in that each connecting device 47 comprises two identical bimetallic strips 48 arranged symmetrically to each other with respect to a plane passing through the central axis of the two supporting elements 30 that said connecting device 47 connects. This embodiment is particularly advantageous in that, taking into account the aforementioned symmetry, the torsional torques which are likely to be generated on the supporting elements 30 around their axis during the deformation of the bimetallic strips 48 compensate each other.

[0130] Figures 11 and 12 illustrate a connecting device 47 according to a sixth embodiment. The connecting device 47 here has a generally rectilinear shape. It comprises two connecting sections 54, 55, rectilinear, which are connected to each other by a contraction compensator 56, also rectilinear. In this embodiment, the two connecting sections 54, 55 are formed by flat metal blades. The contraction compensator 56 is also formed by a flat metal blade. The contraction compensator 56 is sandwiched between the two connecting sections 54, 55. The contraction compensator 56 is welded to the two connecting sections 54, 55 at least in the two fixing zones 57, 58, illustrated in [Fig. 12], and corresponding to the two ends of the contraction compensator 56.Thus, the fixing zone 57 of the connection section 54 to the contraction compensator 56 is positioned along the connecting device 47 between the fixing zone 58 of the other connection section 55 to the contraction compensator 56 and the end of the connection section 55 intended to be fixed to one of the supporting elements 30. Advantageously, the fixing zones 57, 58 are positioned close to the ends of the contraction compensator 58.

[0131] Taking into account the position of the aforementioned fixing zones 57, 58, when the temperature decreases, the contraction of the traction compensator 56 has the effect of generating on the two connection sections 54, 55 traction forces which oppose the contraction of said connection sections 54, 55, which makes it possible to at least partially compensate for the thermal stresses tending to bring the ends of the connecting device 47 closer together.

[0132] Also, according to an advantageous embodiment, the contraction compensator 56 has a coefficient of thermal expansion higher than that of the connection sections.

[0133] Advantageously, the characteristics of the traction compensator 56 and the connection sections 54, 55 are chosen so that, considering the connecting device 47 in isolation from the other elements of the primary thermally insulating barrier 14, in a state free to deform, that is to say before its ends are fixed to the supporting elements 30, the rectilinear distance d between the two ends of the connecting device 47 does not vary or varies by less than 5% and preferably by less than 0.5%, for example of the order of 0.1 to 0.2% during a temperature variation At between the ambient temperature and the temperature to which it is subjected when the tank is loaded with liquefied gas.

[0134] To do this, the lengths L1, L2 and L3 satisfy the following inequality: L1 * oq + L2 * a2- L3 * a3< 0.05 * (L1+L2 - 2*L3) with: Ll: the distance, measured at 20°C, between the end 59 of the first connection section 54 and its attachment zone 57 to the contraction compensator 56 (in meters); ai: 1st coefficient of thermal expansion at 20° of the material in which the first connection section 54 is made; L2: the distance, measured at 20°C, between the end 60 of the second connection section 55 and its attachment zone 58 to the contraction compensator 56 (in meters); a2:1e coefficient of thermal expansion at 20° of the material in which the second connection section 55 is made; L3: the distance, measured at 20°C, between the fixing zones 57, 58 of the contraction compensator 56 to the first and second connection sections 54 (in meters); a3:1e coefficient of thermal expansion at 20° of the material in which the contraction compensator 56 is made.

[0135] [Fig. 13] illustrates a connecting device 47 according to a seventh embodiment. This seventh embodiment takes up the general principle of the sixth embodiment, illustrated in Figures 11 and 12 but differs in that the connecting sections 55, 56 and the contraction compensator 57 are not flat metal blades but have a tubular shape (which is only partially shown, in section in [Fig. 12], in order to facilitate understanding).

[0136] One of the connection sections 55 has an end which is inserted into the other of the connection sections 54 and the contraction compensator 56 is a sleeve which is positioned radially between the two connection sections 54, 55.

[0137] As in the embodiment of [Fig. 12], the rectilinear distance d between the two ends of the connecting device 47 does not vary or varies, preferably, by less than 0.5%, for example of the order of 0.1 to 0.2%.

[0138] In another embodiment shown in [Fig.15], the connecting device 47 is made of a material which has a very low coefficient of thermal expansion, i.e. typically less than 3 x 106 ° K1. Such a material comprises a polymer resin, for example polyamide, as well as carbon fibers and advantageously carbon fibers having a Young's modulus greater than 530 GPa which are for example arranged in the form of a laminate or fabric. Such carbon fibers in fact have the particularity of having a negative coefficient of thermal expansion. Thus, by adapting the proportions of carbon fibers according to the coefficient of thermal expansion of the resin, a composite material is obtained having a very low coefficient of thermal expansion. In such a case, the connecting devices may in particular comprise a blade made of the aforementioned material and the two ends of which are each fixed to one of the two adjacent carrier elements 30.

[0139] With reference to [Fig. 14], a cutaway view of a ship 70, such as a hydrogen carrier, 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.

[0140] 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.

[0141] [Fig. 14] 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 vessel sizes. A connecting pipe, not shown, extends inside the tower 78. The loading and unloading station 75 allows the loading and unloading of the ship 70 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 underwater pipeline 76 allows the transfer of liquefied gas between the loading or unloading station 75 and the onshore installation 77 over a large area. distance, for example 5 km, which allows the vessel 70 to be kept at a great distance from the coast during loading and unloading operations.

[0142] 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 equipping the onshore installation 77 and / or pumps equipping 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.

[0143] Although the invention has been described in connection with several particular embodiments, it is quite obvious that it is in no way limited thereto and that it includes all the technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

[0144] 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 stated in a claim.

[0145] In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

[0146] It will more generally appear to those skilled in the art that various modifications can be made to the embodiments described above, in light of the teaching which has just been disclosed to them. In the following claims, the terms used should not be interpreted as limiting the claims to the embodiments set out in the present description, but should be interpreted to include all equivalents which the claims are intended to cover by virtue of their wording and the prediction of which is within the reach of those skilled in the art based on their general knowledge.

Claims

1. Claims Wall (11) for a sealed and thermally insulating tank for storing a liquefied gas, the wall (11) successively comprising, along a thickness direction of the wall (11), a thermally insulating barrier (14) intended to be anchored to a supporting structure (1) and a sealing membrane (15) which rests against the thermally insulating barrier (14) and is intended to be in contact with the liquefied gas stored in the sealed and thermally insulating tank, the thermally insulating barrier (14) comprising: - a first support element (61) and a second support element (62), the sealing membrane (15) comprising a first zone (63) resting on the first support element (61) and a second zone (64) resting on the second support element (62), - a connecting device (47), intended to be positioned between the waterproofing membrane (15) and the supporting structure (1), and connecting the first support element (61) to the second support element (62) so that a force exerted on the first zone (63) is transmitted from the first support element (61) to the second support element (62) through the connecting device (47);the connecting device (47) having a first end connected to the first support element (61) and a second end connected to the second support element, said connecting device (47) being configured so that, considered in isolation from the first support element (61) and the second support element (62) in a state free to contract, a rectilinear distance d between the first end and the second end varies by less than 5% during a temperature variation At between a temperature of 20°C and a temperature to which said connecting device (47) is intended to be subjected when the tank is loaded with liquefied gas; the connecting device comprising: - a mechanical connection (49, 54, 55) comprising the first end connected to the first support element (61) and the second end connected to the second support element (62); and - a contraction compensator (50, 56) which cooperates with the mechanical connection (49, 54, 55) in such a way that a thermal contraction of said contraction compensator (50, 56) has the effect of at least partially compensating for stresses tending to bringing the first end and the second end of the mechanical connection (49, 54, 55) together during a thermal contraction of said mechanical connection (49, 54, 55); wherein the mechanical connection comprises a connection blade (49) which is curved and which has a concave face and wherein the contraction compensator comprises a compensation blade (50) which is fixed against the concave face of the connection blade (49) so as to form with the connection blade (49) a bimetallic strip (48), the compensation blade (50) having a coefficient of thermal expansion which is lower than a coefficient of thermal expansion of the connection blade (49).

2. Wall (11) according to claim 1, in which the bimetallic strip (48) has a radius of curvature in a plane orthogonal to the thickness direction of the wall.

3. Wall (11) according to claim 2, wherein the first end and the second end of the mechanical connection are respectively mounted articulated on the first support element (61) and the second support element (62) by means of a pivot connection having a degree of freedom in rotation about an axis parallel to the direction of thickness of the wall.

4. A wall (11) according to any one of claims 1 to 3, wherein the first end and the second end of the mechanical connection are respectively fixed to a fixing tab (51) projecting radially from the first support element (61) and the second support element (62).

5. Wall (11) according to any one of claims 1 to 4, in which the bimetallic strip (48) has two ends (52) and a central part (53) and in which the ends (52) of the bimetallic strip have a radius of curvature greater than that of the central part (53).

6. Wall (11) according to any one of claims 1 to 5, wherein the first support element (61) and the second support element (62) each comprise a carrier element (30) which extends in the thickness direction of the wall (11) and an internal plate (42) which is fixed to said carrier element (30) and against which the first zone (62) or the second zone (63) of the waterproofing membrane (15) rests.

7. Wall (11) according to claim 6, in which the supporting element (30) comprises an external base (36), an internal base (37) fixed to the inner plate (42) and a pillar (38) extending between the outer base (36) and the inner base (37).

8. Wall (11) according to claim 7, wherein the first end and the second end of the mechanical connection (49, 54, 55) are respectively connected to the internal base (37) of the first support element (61) and the second support element (62).

9. Wall (11) according to any one of claims 1 to 8, in which the thermally insulating barrier (14) comprises a third support element aligned with the first support element (61) and the second support element (62) in a first direction, a third zone of the sealing membrane (15) resting on the third support element, the third support element being connected to the second support element (6) by a second connecting device (47).

10. A sealed and thermally insulating tank comprising a plurality of walls (11) according to any one of claims 1 to 9.

11. A vessel (70) for transporting a liquefied gas, the vessel comprising a double hull (72) and a tank (71) according to claim 10 disposed in the double hull.

12. A transfer system for a liquefied gas, the system comprising a vessel (70) according to claim 11 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).

13. A method of loading or unloading a vessel (70) according to claim 11, 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 vessel (70).

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