Watertight and thermally insulating tank wall

Abstract

The invention relates to a wall (11) comprising a thermally insulating barrier (14, 12) and a sealing membrane (13, 15) resting against the thermally insulating barrier; the thermally insulating barrier comprising a load-bearing element (20), the load-bearing element comprising: - a pillar (21) rising along the thickness direction of the wall; - an internal plate (22) connected to an internal end of the pillar via a connecting device (30) which retains the internal plate to the pillar along the thickness direction (E), the sealing membrane being fixed to the internal plate, the connecting device having: - one degree of freedom in rotation about a first axis perpendicular to the thickness direction of the wall, and - one degree of freedom in rotation about a second axis perpendicular to the thickness direction of the wall and orthogonal to the first axis. Figure for the abstract: 1

Description

Title of the invention: Waterproof and thermally insulating tank wall Technical field

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

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

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

[0004] One of the main difficulties is that in a tank of the aforementioned type the walls of the tank are subjected to numerous stresses which are not uniform. In particular, the walls are subjected to compressive forces due to the loading of the tank, to thermal stresses during cold setting and to forces due to dynamic shocks of the fluid contained in the tank due to the phenomenon of "sloshing" or sloshing of the fluid in the tank during transport at sea. Also, forces are exerted transversely to the direction of thickness of the wall and are thus likely to cause the elements making up the tank to spill. Summary of the invention

[0005] In order to allow a better distribution of stresses in the waterproofing membrane, the inventors had the idea of ​​a thermally insulating barrier comprising discrete support structures which each support an area of ​​the waterproofing membrane and to which the waterproofing membrane is welded. The discrete support structures comprise, for example, pillars which rise in the direction of thickness of the wall in order to support the waterproofing membrane.

[0006] Such an arrangement has several drawbacks because as indicated above Eventually, the forces exerted transversely are likely to cause the pillars to tilt.

[0007] An idea underlying the invention is therefore to solve the aforementioned problems.

[0008] Another idea underlying the invention is to propose a wall for a tank waterproof and thermally insulating comprising load-bearing elements capable of resisting forces exerted transversely to the direction of thickness of the wall.

[0009] According to one embodiment, the invention provides a wall for a sealed and thermally insulating tank for storing a liquefied gas, the wall comprising, along a thickness direction of the wall, a thermally insulating barrier and a sealing membrane which rests against the thermally insulating barrier; the thermally insulating barrier comprising a load-bearing element, the load-bearing element comprising: - a pillar which rises in the direction of the thickness of the wall; - an internal tray which is connected to an internal end of the pillar via a connecting device which retains the internal tray to the pillar in the thickness direction, the waterproofing membrane being fixed to the internal tray, the connecting device presenting: - a degree of freedom in rotation around a first axis which is perpendicular to the direction of thickness of the wall, and - a degree of freedom in rotation around a second axis which is perpendicular to the direction of thickness of the wall and orthogonal to the first axis.

[0010] Thanks to these characteristics, the connection between the sealing membrane and the pillar allows relative movement between them and thus forms a damping device which attenuates the forces which are likely to be transmitted to the pillar, in particular when the sealing membrane is subject to the sloshing phenomenon. The bending moments exerted on the pillar are thus reduced. The service life of the supporting element and therefore of the tank wall is thus increased compared to a tank wall not having the aforementioned characteristics.

[0011] According to embodiments, such a wall may comprise one or more of the following characteristics.

[0012] According to one embodiment, the connecting device has: - a degree of translational connection along the first axis, and - a degree of translational connection along the second axis.

[0013] According to one embodiment of the wall, the connecting device has a degree of rotational connection according to the thickness direction of the wall.

[0014] According to one embodiment of the wall, the connecting device has a degree of freedom in translation along the thickness direction which is limited to a translation of a determined maximum distance, preferably of a distance less than 3 cm.

[0015] According to one embodiment, the connecting device comprises a support fixed to the internal end of the pillar.

[0016] According to one embodiment, the support comprises a sleeve which is fitted with the internal end of the pillar.

[0017] According to one embodiment, the sleeve is fixed against a longitudinal surface of the pillar.

[0018] According to one embodiment, the sleeve extends beyond the inner end of the pillar.

[0019] According to one embodiment, the sleeve is made of composite or metallic material.

[0020] According to one embodiment, the pillar is hollow.

[0021] According to one embodiment, the pillar is made of composite material.

[0022] According to one embodiment, the internal plate is metallic.

[0023] According to one embodiment, the sealing membrane is welded to the internal metal plate.

[0024] According to one embodiment, the support comprises a closing plate fixed to the internal end of the pillar and covering the internal end of the pillar.

[0025] According to one embodiment, the closing plate is metallic.

[0026] According to one embodiment, the connecting device comprises a ball joint cup and a ball head housed in said ball joint cup, one of the ball joint cup and the ball head being secured to the internal plate and the other being secured to the support.

[0027] The terms “ball joint head” and “ball joint cup” are respectively defined within the meaning of this text as being the protuberance and the receiving cavity of a ball joint connection.

[0028] According to one embodiment, the connecting device is arranged so as to press the ball joint head and the ball joint cup against each other.

[0029] According to one embodiment, the connecting device comprises a rod passing through the ball joint head and the ball joint cup.

[0030] According to one embodiment, the rod of the connecting device has a first end fixed to one of the support and the internal plate.

[0031] According to one embodiment, said rod of the connecting device has a second end fixed to the other element among the support and the internal plate.

[0032] According to one embodiment, said rod of the connecting device has a first end equipped with a stop.

[0033] According to one embodiment, said rod of the connecting device has a second end equipped with a stop.

[0034] According to one embodiment, the connecting device further comprises at least one elastic member or a spherical washer mounted on the rod and arranged between the stop and one of the ball joint cup and the ball joint head so as to press the ball joint head and the ball joint cup against each other.

[0035] According to one embodiment, the connecting device comprises an elastic member or a spherical washer mounted on the rod and arranged between the stop and the ball joint cup and further comprises an elastic member or a spherical washer mounted on the rod and arranged between the stop and the ball joint head, so as to press the ball joint head and the ball joint cup against each other.

[0036] According to one embodiment, said rod of the connecting device has a first end fixed to one of the support and the internal plate and a second end equipped with a stop, the connecting device further comprises at least one elastic member or a spherical washer mounted on the rod and arranged between the stop and one of the ball joint cup and the ball joint head so as to press the ball joint head and the ball joint cup against each other.

[0037] According to one embodiment, the connecting device comprises a rod comprising a first end which is fixed to a first element among the internal plate and the support and a second end comprising a stop, said rod passing through a second element among the internal plate and the support, the connecting device further comprising at least one elastic member or a spherical washer mounted on the rod and positioned between the internal plate and the support so as to press the second element against the stop surface.

[0038] According to one embodiment of the wall, the elastic member is dimensioned to limit the free movement in translation along the thickness direction.

[0039] According to one embodiment, the elastic member comprises a Belleville washer.

[0040] According to one embodiment, the elastic member comprises a plurality of washers Belleville, preferably 2 or 3 Belleville washers.

[0041] According to one embodiment, the rod is a screw comprising a screw head and the stop is the screw head.

[0042] According to one embodiment, the connecting device comprises a plurality of rods spaced apart from each other and a plurality of elastic members, each rod comprising a first end which is fixed to a first element among the internal plate and the support and a second end comprising a stop, said rod passing through a second element among the internal plate and the support, each elastic member mounted on one of the rods and positioned between the internal plate and the support so as to press the second element against the stop surface.

[0043] According to one embodiment, the plurality of rods comprises three rods distributed in such a way that the three segments of the straight lines connecting the rods two by two form an equilateral triangle.

[0044] According to one embodiment, the stop is positioned in a recess provided in the ball joint head or ball joint cup, the elastic member or spherical washer being located in the recess between the screw head and a bottom of the recess.

[0045] According to one embodiment, the sealing membrane is metallic.

[0046] According to one embodiment, the waterproofing membrane is corrugated.

[0047] According to one embodiment, the thermally insulating barrier is a barrier primary thermally insulating barrier and the sealing membrane is a primary sealing membrane, the wall further comprising a secondary thermally insulating barrier which is intended to rest against a supporting structure, a secondary metal sealing membrane which rests against the secondary thermally insulating barrier, the primary thermally insulating barrier resting against the secondary sealing membrane, the primary sealing membrane resting against the primary thermally insulating barrier and being intended to be in contact with the liquefied gas contained in the tank.

[0048] According to one embodiment, the carrier element comprises: - an external tray which is connected to an external end of the pillar via an external connection device which retains the external tray to the pillar in the thickness direction, the secondary waterproofing membrane being fixed to the external tray, the external connection device having: - a degree of freedom in rotation around a first axis which is perpendicular to the direction of thickness of the wall, and - a degree of freedom in rotation around a second axis which is perpendicular to the direction of thickness of the wall and orthogonal to the first axis.

[0049] According to embodiments, the external connecting device is analogous to the connecting device, i.e., it may comprise one or more of the features of the connecting device which is disposed at the outer end of the pillar. For example, according to one embodiment, the external connecting device comprises a support fixed to the outer end of the pillar and comprises a ball joint cup and a ball joint housed in said ball joint cup, one of the ball joint cup and the ball joint head being secured to the outer plate and the other being secured to the support.

[0050] According to one embodiment, the external plate is metallic.

[0051] According to one embodiment, the secondary sealing membrane is welded to the external metal tray.

[0052] According to one embodiment, the secondary thermally insulating barrier comprises the load-bearing element.

[0053] According to one embodiment, the secondary thermally insulating barrier comprises a plurality of load-bearing elements.

[0054] According to one embodiment, the primary thermally insulating barrier comprises the aforementioned load-bearing element.

[0055] According to one embodiment, the primary thermally insulating barrier comprises a plurality of load-bearing elements.

[0056] According to one embodiment, the secondary thermally insulating barrier and the primary thermally insulating barrier each comprise the load-bearing element. According to one embodiment, the primary thermally insulating barrier and the secondary thermally insulating barrier comprise a plurality of load-bearing elements.

[0057] According to one embodiment, the primary sealing membrane comprises a first series of corrugations having first corrugations parallel to each other and a second series of corrugations having second corrugations parallel to each other and perpendicular to the first corrugations, the primary sealing membrane comprises a plurality of flat areas which are each defined between two adjacent first corrugations and between two adjacent second corrugations, the plurality of flat areas of the primary sealing membrane comprising a first flat area which is welded against the internal plate of the carrier element.

[0058] According to one embodiment, the secondary sealing membrane comprises a first series of corrugations having first corrugations parallel to each other and a second series of corrugations having second corrugations parallel to each other and perpendicular to the first corrugations, the secondary sealing membrane comprising a plurality of flat zones which are each defined between two adjacent first corrugations and between two adjacent second corrugations, the plurality of flat zones of the secondary sealing membrane comprising a first flat zone which is welded against the external plate of the carrier element.

[0059] According to one embodiment, the primary thermally insulating barrier has a gaseous phase under vacuum, preferably at an absolute pressure of less than 1 Pa.

[0060] According to one embodiment, the secondary thermally insulating barrier has a gaseous phase under vacuum, preferably at an absolute pressure of less than 1 Pa.

[0061] In one embodiment, the liquefied gas is liquid hydrogen.

[0062] According to one embodiment, the invention also provides a sealed and thermally insulating tank comprising at least a first and a second wall as mentioned above.

[0063] According to one embodiment of the tank, the first wall and the second wall form an angle of the tank, and the first wall and the second wall each comprise a row of support elements supporting the sealing membrane which extends parallel to the edge, in which the row comprises the supporting element.

[0064] According to one embodiment of the tank, the first wall and the second wall comprise: - a first row of support elements supporting the waterproofing membrane which extends parallel to the edge and which is located near the corner of the tank, and - a second row of support elements supporting the waterproofing membrane which extends parallel to the edge and which is adjacent to the first row, in which the second row comprises the load-bearing element.

[0065] 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 hydrogen carrier, 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.

[0066] According to one embodiment, a ship for transporting a liquefied gas comprises a double hull and a aforementioned tank arranged in the double hull.

[0067] 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.

[0068] 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 vessel's tank.

[0069] 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 ship's tank. Brief description of the figures

[0070] 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.

[0071] [Fig.l] represents a partial schematic sectional view of a wall of a sealed and thermally insulating tank according to one embodiment.

[0072] [Fig.2] represents a partial, schematic sectional view of a supporting element according to a first variant of a first embodiment.

[0073] [Fig. 3] represents a partial, schematic sectional view of a load-bearing element according to a second variant of the first embodiment.

[0074] [Fig.4] represents a partial perspective view of the carrier element according to the second variant of the first embodiment, represented in [Fig.3].

[0075] [Fig. 5] represents a partial, schematic sectional view of a supporting element according to a third variant of the first embodiment.

[0076] [Fig.6] represents a partial, schematic sectional view of a supporting element according to a first variant of a second embodiment.

[0077] [Fig.7] represents a partial, schematic sectional view of a supporting element according to a second variant of the second embodiment.

[0078] [Fig.8] represents a partial, schematic sectional view of a supporting element according to a third variant of the second embodiment.

[0079] [Fig.9] represents a partial, schematic sectional view of a supporting element according to a fourth variant of the second embodiment.

[0080] [Fig. 10] represents a partial, schematic sectional view of a supporting element according to a third embodiment.

[0081] [Fig. 11] represents a cutaway and schematic perspective view of a supporting structure intended to support a sealed and thermally insulating tank for storing liquefied gas.

[0082] [Fig. 12] represents a partial view, in section, of an angle of a sealed and thermally insulating tank for storing a liquefied gas, according to one embodiment.

[0083] [Fig. 13] shows a schematic cutaway representation of a tank of a ship and a terminal for loading and unloading this tank. Description of the embodiments

[0084] 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.

[0085] In relation to [Fig. 1], a wall 11 intended to be integrated into a sealed and thermally insulating tank according to one embodiment is described below in a general manner.

[0086] The wall 11 has a multi-layer structure comprising, along the thickness direction E of the wall 11, from the outside to the inside, a secondary thermally insulating barrier 12, a secondary sealing membrane 13 which is corrugated and fixed against the secondary thermally insulating barrier 12, a primary thermally insulating barrier 14 and a primary sealing membrane 15 which is corrugated and fixed against the primary thermally insulating barrier 14. The primary sealing membrane 15 is intended to be in contact with the liquefied gas, such as liquid hydrogen, which is intended to be contained in the tank.

[0087] The secondary thermally insulating barrier 12 comprises a plurality of insulating panels 16 anchored to a supporting structure 1. The insulating panels 16 each comprise a layer of insulating polymer foam 17 sandwiched between an internal plate 18 and an external plate 19. The internal 18 and external 19 plates are, for example, plywood plates glued onto said layer of insulating polymer foam 17. The insulating polymer foam 17 may in particular be a polyurethane-based foam preferably reinforced with fibers.

[0088] The primary thermally insulating barrier 14 comprises a plurality of load-bearing elements 20 extending along the thickness direction E of the wall 11, between the secondary sealing membrane 13 and the primary sealing membrane 15. The load-bearing elements 20 each comprise a pillar 21 of cylindrical shape. Each pillar 21 is connected at its inner end to an inner plate 22 via a connecting device 30 and is fixed at its outer end to an outer plate 23.

[0089] The primary sealing membrane 15 is welded, at each flat area located between two pairs of corrugations, against a respective internal plate 22.

[0090] The secondary sealing membrane 13 is welded, at the level of each flat zone located between two pairs of corrugations, on metal plates (not shown) housed and fixed in the external plate 23.

[0091] The pillar 21 is preferably made from a composite material comprising fibers and a matrix. The internal plate 22 and the external plate 23 are metallic, for example made of stainless steel.

[0092] The connecting device has a degree of freedom in rotation about a first axis XI which is perpendicular to the direction of thickness E of the wall 11, and a degree of freedom in rotation about a second axis X2 which is perpendicular to the direction of thickness E of the wall 11 and orthogonal to the first axis.

[0093] Furthermore, the gas phase of the primary thermally insulating barrier 14 is advantageously placed under vacuum, for example at an absolute pressure of less than 1 Pa and preferably less than 10 2 Pa. To do this, the primary thermally insulating barrier 14 is advantageously connected to a vacuum pump. By virtue of the gas phase being placed under vacuum, the thermal insulation properties of the primary insulating barrier 14 are increased. However, the vacuum conditions of the primary thermally insulating barrier 14 will tend to deform the primary sealing membrane 15 and the secondary sealing membrane 13 towards the inside of the primary thermally insulating barrier 15.

[0094] The arrangement of the plurality of supporting elements 20 generally makes it possible to support the primary sealing membrane 15 by absorbing, on the one hand, the forces due to the hydrostatic and dynamic pressures exerted on the membrane primary sealing 15, by the liquefied gas contained inside the tank, and on the other hand the forces due to the aforementioned vacuum conditions.

[0095] In connection with Figures 2 to 10, a plurality of embodiments of the carrier element are described below.

[0096] Identical or similar elements bear the same reference numbers incremented by a multiple of 100.

[0097] In relation to [Fig.2], a first variant of a first embodiment of the carrier element is described below.

[0098] The supporting element 120 comprises a pillar 121 which is hollow, an internal plate 122 and a connecting device 130 which allows the internal plate 122 to be connected to the internal end of the pillar 121.

[0099] The connecting device 130 comprises a support 131 which is a metal sleeve fitted into the internal end of the pillar 121 and bonded via a layer of glue 191 against an internal longitudinal surface of the pillar 121. The sleeve extends beyond the internal end of the pillar 121, forming a receiving collar 132 which has a diameter greater than the external diameter of the pillar 121.

[0100] The connecting device 130 comprises three threaded rods 133, designated screws in the remainder of the description, and only one of which is present in the section plane of [Fig.2]. The three screws 133 are regularly positioned on a geometric circle concentric with the longitudinal axis of the pillar 121. In other words, the three screws 133 are distributed in such a way that the three segments of the straight lines connecting the rods two by two form an equilateral triangle. The screws 133 pass through the internal plate 122 and each comprise an internal end 134 screwed into a tapped hole 135 which is positioned in the receiving collar 132. The screws 133 further comprise, at the internal end 136, a screw head which is positioned in a countersink 123 made in the internal surface 124 of the internal plate 122.

[0101] The connecting device 130 further comprises an elastic member 137 which is a spring washer, also called an elastic washer or Belleville washer.

[0102] The elastic member 137 is mounted on the screw 133, between the internal plate 122 and the receiving collar 132 so as to press the internal plate 122 against the screw head 136.

[0103] When forces are exerted on the primary sealing membrane which is welded to the internal plate 122, the elastic crushing properties of the elastic member 137 allow a rotational movement of the internal plate 122 along a first axis XI which is perpendicular to the thickness direction of the wall and along a second axis X2 which is perpendicular to the thickness direction E of the wall and orthogonal to the first axis XL. When the transverse forces cease to be exerted against the internal plate 122, the elastic member 137 returns to its initial shape and the internal plate 122 returns to its initial position.

[0104] When forces are exerted, parallel to the thickness direction E, and uniformly on the internal plate 122, the elastic properties of the elastic member 137 allow a translational movement of the internal plate 122, according to the thickness direction E of the wall. Such a movement brings the internal plate 122 closer to the fixing collar 132, reducing the distance between the internal plate 122 and the fixing collar 132 by a distance less than or equal to the distance represented by the elastic crushing capacity of the elastic member 137. When the forces cease to be exerted, the elastic member 137 returns to its initial shape and the internal plate 122 to its initial position.

[0105] In relation to Figures 3 and 4, a second variant of the first embodiment of the carrier element is described below.

[0106] The carrier element 520 differs from that of [Fig. 2] in that the support 531 is a closure plate, for example made of metal, which covers the opening of the hollow pillar 521. The closure plate has a diameter similar or identical to the diameter of the pillar 521.

[0107] The carrier element 520 comprises three rods 533, only one of which is visible in the section plane of [Fig. 3], the rods 533 each pass through the internal plate 522 and each comprise an external end 534 fixed in a hole 535 which is provided in the closing plate and an internal end 536 fixed in a recess 525 comprising a bottom 526. The fixing of the rods 533 to the support 531 is for example carried out via a thread and tapping system. The screws 533 can be adjusted by screwing into the tapped hole 535 in order to adjust the height of the internal plate 522.

[0108] The connecting device 530 comprises four Belleville washers 537 superimposed and mounted on each rod 533, between the internal plate 522 and the closing plate.

[0109] The three rods 533 are distributed around the periphery of the closing plate 531 in such a way that the three segments of the straight lines connecting the rods two by two form an equilateral triangle.

[0110] In relation to [Fig.5], a third variant of the first embodiment of the carrier element is described below.

[0111] The carrier element 820 differs from [Fig. 2] in that it comprises a first metal part 840 positioned against the outer surface 827 of the inner plate 822 and fixed against the outer surface 827 via fixing screws 841. The carrier element 820 further comprises a second metal part 850 located opposite the first metal part 840. The second metal part 850 is positioned against the inner surface of the receiving collar 832 and fixed against the receiving collar 832 via fixing screws 844.

[0112] The carrier element comprises a central threaded rod 833 which passes through the hole 835 which is arranged in the second metal part 850. The threaded rod 833 has an external end 834 which is fixed via a stop against an external surface of the second metal part 850 at the hole 835. The threaded rod further comprises an internal end 836 fixed via a stop in a recess 825 comprising a bottom 826 located in the first metal part 840. The fixing of the rod 833 to the first metal part 840 and to the second metal part 850 is for example carried out via a screw nut system. Optionally, the Belleville washers 837 can be adjusted, for example constrained via the tightening or loosening of the nuts mounted on the rod 833.

[0113] In relation to [Fig.6], a first variant of a second embodiment of the carrier element is described below.

[0114] The carrier element 220 differs from that of [Fig. 2] in that the connecting device 230 comprises a ball head 238 housed in a ball socket 239. The ball socket 239 is formed in the receiving collar 232, at the center of the diameter of the receiving collar 232. The ball head 238 is formed by a protrusion projecting from the internal plate 222 and has a shape complementary to that of the ball socket 239.

[0115] The connecting device 230 comprises a screw 233 which passes through the internal plate 222, the ball head 238 and the ball cup 239. The external end 234 of the screw 233 is fixed in a hole 235 formed in the ball cup 239 and the internal end of the screw 233 comprises a screw head 236 which is positioned in a recess 225 formed in the internal surface 224 of the internal plate 222, the recess 225 comprising a bottom 226. The elastic member 237 is located in the recess 225 between the screw head 233 and the bottom 226 of the recess 225 so as to press the internal plate 222 against the receiving collar 232, while allowing a degree of freedom in rotation about the first axis XI and a degree of freedom in rotation around the second axis X2.

[0116] In relation to [Fig.7], a second variant of the second embodiment of the carrier element is described below.

[0117] The carrier element 320 differs from that of [Fig. 6] in that the metal sleeve 331 does not have a receiving collar, and in that the ball head 338 projects from a metal part 340 positioned against the external surface 327 of the internal plate 322. The metal part 340 has a diameter greater than the external diameter of the pillar 321.

[0118] The metal part 340 is fixed to the internal plate 322 via fixing screws 341 located on the periphery of the metal part 340. The fixing screws 341 pass through the internal plate 322 and the metal part 340. The fixing screws 341 each have an external end 342 which is fixed to the metal part 340, for example by riveting, and an inner end 343 which has a screw head which is housed in a countersink 323 formed in the inner surface 324 of the inner plate 322.

[0119] In relation to [Fig.8], a third variant of the second embodiment of the carrier element is described below.

[0120] The carrier element 420 differs from that of [Fig.6] in that it comprises a first metal part 440 positioned against the external surface 427 of the internal plate 422 and fixed against the external surface 427 via fixing screws 441. The carrier element 420 further comprises a second metal part 450 located opposite the first metal part 440. The second metal part 450 is positioned against the internal surface of the receiving collar 432 and fixed against the receiving collar 432 via fixing screws 444.

[0121] The first metal part 440 comprises a ball head 438 forming a protrusion from the external surface 445 and the second metal part 450 comprises a base 452 projecting from the internal surface 451 of the second metal part 450, the base comprising the ball socket 439. The ball head 438 is housed in the ball socket 439.

[0122] The first metal part 440, the second metal part 450 and the receiving collar 432 have, for example, an identical or similar diameter.

[0123] The screw 433 passes through the inner plate 422, the first metal part 440, the ball head 438, the ball cup 439 and the second metal part 450. The screw 433 has an outer end which is fixed in the second metal part 450.

[0124] According to an alternative embodiment of [Fig.8], the elastic member 437 is replaced by a spherical washer located in the recess 425 between the screw head 436 and the bottom 426 of the recess 425. The spherical washer comprises two parts which cooperate with each other by spherical surfaces, which allows mobility of the screw head 436 relative to the internal plate 422.

[0125] In relation to [Fig.9], a fourth variant of the second embodiment of the carrier element is described below.

[0126] The carrier element 620 differs from that of [Fig.7] in that the support is a closure plate 631. The ball joint cup 639 is provided in the closure plate 632, at the center of the diameter of the closure plate 632.

[0127] The fixing rod 633 passes through the internal plate 622, the metal part 640 and the closing plate 632.

[0128] The rod 633 has an outer end 634 fixed in a hole 635 which is provided at the center of the diameter of the closure plate 632 and an inner end fixed via a rod head 636 in the recess 625 provided in the inner plate 622.

[0129] In relation to [Fig. 10], a third embodiment is described below.

[0130] The carrier element 920 differs from that of [Fig.8] in that it does not include the ball head 438 and the base 452 illustrated in [Fig.8] and in that the elastic member 837 is positioned between the first metal part 940 and the second metal part 950.

[0131] The fixing of the threaded rod 933 to the first metal part 940 and to the second metal part 950 is for example carried out in a manner similar to the embodiment illustrated via [Fig.5], that is to say via screw-nut systems.

[0132] The aforementioned wall 11, comprising one or more aforementioned load-bearing elements, is intended to be integrated into a sealed and thermally insulating tank for storing a liquefied gas. The liquefied gas intended to be stored in the tank may in particular be liquid hydrogen which has the particularity of being stored at approximately -253°C at atmospheric pressure.

[0133] Such a tank is fixed against a supporting structure 1 as illustrated in [Fig.11].

[0134] 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 1 is, for example, formed by the double hull of a ship. In [Fig.l 1], the supporting structure 1 has a generally polyhedral shape. It has two front and rear load-bearing walls 2, here of octagonal shape, of which only the rear load-bearing wall 2 is shown. The front and rear walls 2 are, for example, cofferdam walls of a 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.

[0135] [Fig. 12] illustrates a sealed and thermally insulating tank angle 171 for storing a liquefied gas. The tank comprises a first tank wall 111 and a second tank wall 211 forming a tank angle, the first and second walls 111, 211 being connected in a connection zone 92. The first and second tank walls may have the aforementioned characteristics.

[0136] The secondary sealing membrane 113 of the first tank wall 111 is connected to the secondary sealing membrane of the second tank wall 211 in the connection zone 92.

[0137] The primary sealing membrane 115 of the first tank wall 111 is connected to the primary sealing membrane of the second tank wall 211 in the connection zone 92.

[0138] The first tank wall 111 and the second tank wall 211 each comprise, at the level of the primary thermally insulating barrier, a first row 95 of support elements supporting the primary sealing membrane which extends parallel to the edge formed at the intersection between the first and second walls and whose support elements extend in the direction of thickness of their respective wall, between the secondary sealing membrane 113 and the primary sealing membrane 115.

[0139] The first tank wall 111 and the second tank wall 211 each further comprise, at the primary thermally insulating barrier, a second row 96 of support elements, parallel to the first row, the support elements of which also extend in the direction of thickness of their respective wall. The support elements of each second row 96 comprise load-bearing elements 720 comprising, for example, the characteristics of a load-bearing element such as illustrated in one of FIGS. 1 to 10.

[0140] Such an arrangement of load-bearing elements 720 makes it possible to take up the forces which are exerted transversely to the direction of thickness of the wall.

[0141] Such forces are exerted for example when the tank is filled with liquefied gas. Indeed, when the tank is filled with liquefied gas, a sudden drop in temperature is observed. Consequently, phenomena of thermal contraction of the various elements making up the tank are observed, in particular at the angles of the tank which generate in particular forces which are exerted transversely to the direction of thickness of the wall. Such forces cause an instability phenomenon affecting the load-bearing elements and mainly the pillars which undergo bending moments. The aforementioned load-bearing elements 720 make it possible to reduce the bending moments and therefore make it possible to increase the service life of the tank.

[0142] With reference to [Fig. 13], 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.

[0143] 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.

[0144] [Fig. 13] also shows an example of a marine terminal comprising a loading and unloading station 75, an underwater pipeline 76 and a shore installation 77. The loading and unloading station 75 is an installation fixed offshore 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 pipes 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 loading and unloading of the hydrogen carrier 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 long distance, for example 5 km, which makes it possible to keep the hydrogen carrier 70 at a great distance from the coast during loading and unloading operations.

[0145] 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.

[0146] 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.

[0147] The use of the verb “comporter”, “comprendre” and its conjugated forms does not exclude the presence of other elements or other steps than those stated in a claim.

[0148] In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims

Claims

1. Wall for a sealed and thermally insulating tank for storing a liquefied gas, the wall (11, 111, 211) comprising, in a thickness direction (E) of the wall, a thermally insulating barrier (12, 14) and a sealing membrane (13, 15, 113, 115) which rests against the thermally insulating barrier; the thermally insulating barrier comprising a supporting element (20, 120, 220, 320, 420, 520, 620, 720, 820, 920), the supporting element comprising: - a pillar (21, 121, 221, 321, 421, 521, 621, 721, 821, 921) which rises in the thickness direction of the wall;- an internal plate (22, 122, 222, 322, 422, 522, 622, 722, 822, 922) which is connected to an internal end of the pillar via a connecting device (30, 130, 230, 330, 430, 530, 630, 730, 830, 930) which retains the internal plate to the pillar in the thickness direction, the waterproofing membrane being fixed to the internal plate, the connecting device having: - a degree of freedom in rotation about a first axis (XI) which is perpendicular to the thickness direction of the wall, and - a degree of freedom in rotation about a second axis (X2) which is perpendicular to the thickness direction of the wall and orthogonal to the first axis.;

2. Wall according to claim 1, in which the connecting device has: - a degree of translational connection along the first axis (XI), and - a degree of translational connection along the second axis (X2).

3. A wall according to claim 1 or 2, wherein the connecting device comprises a support (131, 231, 331, 431, 531, 631, 831, 931) fixed to the inner end of the pillar.

4. Wall according to claim 3, in which the support comprises a sleeve (131, 231, 331, 431, 831, 931) which is fitted with the internal end of the pillar.

5. A wall according to claim 3, wherein the support comprises a closure plate (531, 631) fixed to the inner end of the pillar and covering the inner end of the pillar.

6. Wall according to one of claims 3 to 5, in which the connecting device comprises a ball joint cup (239, 339, 439, 639) and a head ball joint (238, 338, 438, 638) housed in said ball joint cup, one of the ball joint cup and the ball joint head being integral with the internal plate and the other being integral with the support.

7. Wall according to claim 6, in which the connecting device is arranged so as to press the ball head and the ball cup against each other.

8. Wall according to claim 7, in which the connecting device comprises a rod (233, 333, 433, 633) passing through the ball head and the ball cup, the rod has a screw head which forms a stop, the connecting device further comprising an elastic member (237, 337, 437, 637) or a spherical washer mounted on the rod and arranged between the stop and one of the ball cup and the ball head so as to press the ball head and the ball cup against each other.

9. Wall according to any one of claims 3 to 5, in which the connecting device comprises a rod (133, 533, 833, 933) having a first end (134, 534, 834, 934) which is fixed to a first element among the internal plate and the support and a second end (136, 536, 836, 936) having a stop, said rod passing through a second element among the internal plate and the support, in which the connecting device further comprises at least one elastic member (137, 537, 837, 937) mounted on the rod and positioned between the internal plate and the support so as to press the second element against the stop surface.

10. A wall according to claim 9, wherein the connecting device comprises a plurality of rods spaced apart from each other and a plurality of elastic members, each rod (133, 533) having a first end (134, 534) which is fixed to a first element among the internal plate and the support and a second end comprising a stop (136, 536), said rod passing through a second element among the internal plate and the support, each elastic member (137, 537, 837) mounted on one of the rods and positioned between the internal plate and the support so as to press the second element against the stop surface.

11. A wall according to claim 10, wherein the plurality of rods comprises three rods distributed so that the three segments of the straight lines connecting the rods two by two form an equilateral triangle.

12. Wall according to one of claims 1 to 11, in which the thermally insulating barrier is a primary thermally insulating barrier (14) and the sealing membrane is a primary sealing membrane (15, 115), the wall further comprising a secondary thermally insulating barrier (12) which is intended to rest against a supporting structure (1), a secondary metallic sealing membrane (13, 113) which rests against the secondary thermally insulating barrier, the primary thermally insulating barrier resting against the secondary sealing membrane, the primary sealing membrane resting against the primary thermally insulating barrier and being intended to be in contact with the liquefied gas contained in the tank (71, 171), wherein the supporting element comprises: - an external plate (23, 123) which is connected to an external end of the pillar via an external connection device which retains the external plate to the pillar in the thickness direction, the secondary sealing membrane being fixed to the external plate,the external connecting device having: - a degree of freedom in rotation around a first axis which is perpendicular to the direction of thickness of the wall, and - a degree of freedom in rotation around a second axis which is perpendicular to the direction of thickness of the wall and orthogonal to the first axis.,

13. Sealed and thermally insulating tank comprising at least a first and a second wall (111, 211) according to any one of claims 1 to 12.

14. A sealed and thermally insulating tank according to claim 13, wherein the first wall (111) and the second wall (211) form an angle of the tank, and wherein the first wall and the second wall each comprise a row (95, 96) of support elements supporting the sealing membrane which extends parallel to an edge formed by the angle of the tank, wherein the row (95, 96) comprises the supporting element (20, 120, 220, 320, 420, 520, 620, 720, 820, 920).

15. A vessel (70) for transporting a liquefied gas, the vessel comprising a double hull (72) and a tank (71) according to claim 13 or 14 disposed in the double hull.

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

17. A method of loading or unloading a vessel (70) according to claim 15, 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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