Facility for storing a liquefied gas

Abstract

The invention relates to a facility for storing a liquefied gas, wherein each of the first, second and third tank walls includes at least one sealing membrane (7) and at least one thermally insulating barrier (6), wherein the sealing membrane (7) includes a plurality of strakes (11), wherein the tank includes a connecting beam (13) sealingly connecting the sealing membranes, the connecting beam (13) comprising a trihedral section (14), comprising: - a central core (17); - first, second and third connecting flanges; - a first anchoring flange (30) being attached to a first anchoring plate; - a third anchoring flange (32) being attached to a second anchoring plate, wherein the first anchoring flange (30) and the third anchoring flange (32) are connected to one another by a connecting edge (37), wherein the trihedral section (14) includes a notch (38) at the connecting edge (37), the notch (38) being made on the side of the outer edges of the first and third anchoring flanges.

Description

Liquefied gas storage facility

[0001] The invention relates to the field of leak-proof and thermally insulated membrane tanks. In particular, the invention relates to the field of leak-proof and thermally insulated tanks for the storage and / or transport of liquefied gases at low temperatures, such as tanks for transporting Liquefied Petroleum Gas (LPG) at temperatures ranging, for example, from -50°C to 0°C, or for transporting Liquefied Natural Gas (LNG) at approximately -162°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 used for transporting liquefied gas or for receiving liquefied gas to serve as fuel for the propulsion of the floating structure. Technological background

[0002] It is known from document WO202253320 of liquefied gas storage facilities comprising a load-bearing structure and a sealed and thermally insulated tank supported by the load-bearing structure.

[0003] The tank in this document includes, in particular, a watertight membrane which has a plurality of strakes, each having a flat central portion resting on an upper surface of the insulating barrier and two raised edges projecting inwards from the flat central portion of the tank, the strakes being juxtaposed and welded together in a watertight manner at the raised edges.

[0004] This watertight membrane is anchored to the supporting structure using a connecting beam at the edges formed between two tank walls and also at the corners formed at the intersection of three tank walls. The connecting beam also serves to create a watertight seal between the strakes of one wall and the strakes of a second wall.

[0005] Events such as temperature changes or the deflection of the ship's beam when the storage facility is located on a vessel impose significant stresses on the watertight membrane, which are transmitted to the supporting structure via the connecting beam. These stresses are particularly pronounced at watertight membrane connections along the ship's strakes and in special areas such as trihedral angles. The coefficient of thermal expansion of the material used for the watertight membrane also directly influences the value of these stresses.

[0006] One idea behind the invention is to improve the mechanical strength of the connecting beam of a storage installation, particularly at the level of a trihedron formed by the intersection of three tank walls.

[0007] According to one embodiment, the invention provides a liquefied gas storage installation comprising a load-bearing structure and a sealed and thermally insulated tank supported by the load-bearing structure, the tank having a first tank wall fixed to a first load-bearing wall, a second tank wall fixed to a second load-bearing wall and a third tank wall fixed to a third load-bearing wall, the first, second and third tank walls forming a trihedron; the first load-bearing wall and the second load-bearing wall meeting at a first edge extending in a first direction, the first load-bearing wall and the third load-bearing wall meeting at a second edge extending in a second direction, the second load-bearing wall and the third load-bearing wall meeting at a third edge extending in a third direction, the first edge,the second edge and the third edge meeting at a corner of the supporting structure, wherein each of the first, second and third tank walls comprises at least one watertight membrane and at least one thermally insulating barrier arranged between the watertight membrane and one of the first, second and third supporting walls, wherein the watertight membrane of each of the first and third tank walls comprises a plurality of strakes, each comprising at least one flat portion resting on an upper surface of the thermally insulating barrier and at least one projecting portion protruding into the interior of the tank relative to the flat portion, the strakes being juxtaposed and welded together watertight at the edges, the strakes of the first tank wall and the third tank wall extending in the second direction,in which the tank includes a connecting beam connecting in a watertight manner the watertight membranes of the first, second and third tank walls, the connecting beam comprising a trihedral section along the first edge and the third edge and being located at the corner of the supporting structure, the trihedral section comprising: - a central core having a first portion of length extending parallel to the first edge and a second portion of length extending parallel to the third edge and, - a first connecting flange projecting from the first portion of length of the central core away from the second supporting wall and being fixed to the watertight membrane of the first tank wall,- a second connecting wing comprising first and second sections projecting from the first and second lengths of the central core, respectively away from the first and third load-bearing walls, and fixed to the watertight membrane of the second tank wall; - a third connecting wing projecting from the second length of the central core, away from the second load-bearing wall, and fixed to the watertight membrane of the third tank wall; - a first anchoring wing projecting from the first length of the central core towards the second load-bearing wall, aligned with the first connecting wing, an outer edge of the first anchoring wing being fixed to a first anchoring plate of the second load-bearing wall, the first anchoring wing and the first connecting wing being located on either side of the first length of the central core.- a third anchoring wing projecting from the second portion of the length of the central core towards the second load-bearing wall, being aligned with the third connecting wing, an outer edge of the third anchoring wing being fixed to a second anchoring plate of the second load-bearing wall, the third anchoring wing and the third connecting wing being situated on either side of the second portion of the length of the central core, in which the first anchoring wing and the third anchoring wing are connected to each other by a connecting edge parallel to the second edge and are inclined to each other at an angle of inclination between the first tank wall and the third tank wall, in which the trihedral section has a notch at the connecting edge between the first anchoring wing and the third anchoring wing,The notch is made on the outer edges of the first and third anchor wings so as to leave a space between the outer edge of the first anchor wing and the outer edge of the third anchor wing.

[0008] Thanks to these features, the notch made on the anchor flanges of the trihedral section provides flexibility at the corner of the installation formed by the intersection of three load-bearing walls. Indeed, at a corner, the anchor plates of one load-bearing wall are not necessarily aligned with the anchor plates of the adjacent load-bearing wall, which can generate additional stresses. Furthermore, welds can interfere with the attachment of the anchor flanges to the anchor plates.

[0009] Depending on the embodiment, such an installation may include one or more of the following characteristics.

[0010] According to one embodiment, the trihedral section includes a second anchoring wing having first and second faces projecting from the first and second length portions of the central core towards the first and third load-bearing walls respectively, being aligned with the second connecting wing, the first face of the second anchoring wing being fixed to an anchoring plate of the first load-bearing wall and the second face of the second anchoring wing being fixed to an anchoring plate of the third load-bearing wall, the second anchoring wing and the second connecting wing being located on either side of the central core.

[0011] According to one embodiment, the outer edge of the first anchoring wing is welded to the anchoring plate of the second load-bearing wall.

[0012] According to one embodiment, the outer edge of the third anchor wing is welded to the anchor plate of the second load-bearing wall.

[0013] According to one embodiment, the notch extends in the second direction and includes a first lateral edge on the first anchoring wing, a second lateral edge on the third anchoring wing and a bottom connecting the first lateral edge to the second lateral edge, the bottom having a rounded shape.

[0014] According to one embodiment, the first lateral edge has a first cutout of rounded shape extending in the first direction and / or the second lateral edge has a second cutout of rounded shape extending in the third direction.

[0015] Thus, the cut allows for improved flexibility of the anchor wings.

[0016] According to one embodiment, the first cut is made at a distance from the bottom of the notch and at a distance from the outer edge of the first anchor wing in the second direction and the second cut is made at a distance from the bottom of the notch and at a distance from the outer edge of the third anchor wing in the second direction.

[0017] According to one embodiment, the first anchoring wing and / or the third anchoring wing has an opening located near the notch, preferably aligned in the first direction or in the third direction with the cutout.

[0018] According to one embodiment, the strakes (11) are made of an alloy whose coefficient of thermal expansion is less than or equal to 10.10 -6 K -1 .

[0019] According to one embodiment, the strakes (11) are made of an iron alloy with a high manganese content having a coefficient of thermal expansion between 6 and 10.10 -6 K -1 , for example, in the order of 7.10 -6 K -1 or in an iron and nickel alloy with a coefficient of expansion between 0.5 x 10 -6 and 2.10 -6 K -1 .

[0020] According to one embodiment, the connecting beam (13) is made of an iron and nickel alloy having a coefficient of expansion between 0.5 x 10 -6 and 2.10 -6 K -1 .

[0021] According to one embodiment, the strakes of the second tank wall extend in the first direction.

[0022] According to one embodiment, the strakes each comprise a flat central portion resting on an upper surface of the thermally insulating barrier and two raised edges projecting towards the inside of the tank relative to the flat central portion, the strakes being juxtaposed and welded together in a watertight manner at the raised edges.

[0023] In one embodiment, the strakes each comprise at least two flat portions resting on an upper surface of the thermally insulating barrier and at least one corrugation projecting inwards from the flat portions, the flat portions being on either side of a corrugation. The strakes are juxtaposed and welded together watertight at the edges, for example by lap welding.

[0024] According to one embodiment, the thickness of the first and third anchoring wings is identical to the thickness of the first and third connecting wings, for example on the order of 3 mm.

[0025] According to one embodiment, the central core comprises a plurality of walls, each of the walls having a thickness of between 2 and 4 mm.

[0026] According to one embodiment, the strakes comprise main strakes and end strakes, the end strakes connecting the main strakes to the connecting beam.

[0027] According to one embodiment, the main strakes have a thickness less than the thickness of the first and second anchor wings and / or greater than the thickness of the first and second connecting wings, the thickness of the main strakes being between 0.5 and 1 mm, for example on the order of 0.7 mm.

[0028] According to one embodiment, the thickness of the end strakes is between 1.2 and 2 mm, for example on the order of 1.5 mm.

[0029] According to one embodiment, the strakes are made of an iron alloy with a high manganese content.

[0030] According to one embodiment, the high manganese iron alloy comprises between 24 and 34% Mg by weight.

[0031] Such a facility can be a land-based storage facility, for example for storing LNG, or a floating structure, coastal or deep-water, including an LNG carrier, a floating storage and regasification unit (FSRU), a floating production and storage unit (FPSO), and others. Such a facility can also serve as a fuel tank on any type of ship.

[0032] According to one embodiment, a ship for the transport of a cold liquid product comprises a double hull and the aforementioned storage facility, the double hull comprising the load-bearing structure of the storage facility.

[0033] According to one embodiment, the invention also provides a transfer system for a cold liquid product, the system comprising the aforementioned vessel, insulated pipes arranged to connect the vessel's tank to a floating or land-based storage facility, and a pump to drive a flow of cold liquid product through the insulated pipes from or to the floating or land-based storage facility to or from the vessel's tank.

[0034] According to one embodiment, the invention also provides a method for loading or unloading a ship, in which a cold liquid product is conveyed through insulated pipes from or to a floating or land-based storage facility to or from the tank of the aforementioned ship. Brief description of the figures

[0035] The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent from the following description of several particular embodiments of the invention, given solely by way of illustration and not limitation, with reference to the accompanying drawings.

[0036] Lare represents a partial cutaway perspective view of a storage facility at the junction between two load-bearing walls.

[0037] This is a perspective view of a storage installation according to an embodiment at the junction between three load-bearing walls, where only the secondary parts of the first tank wall and the second tank wall have been shown.

[0038] This is a detailed view illustrating in particular the trihedral section of the connecting beam placed at the corner of the load-bearing structure.

[0039] This is a perspective view of a trihedral segment according to one embodiment.

[0040] This is a detailed view of the [unclear] illustrating more particularly the notch in the trihedral section.

[0041] This is a detailed view of the one illustrating in particular the notch of the trihedral section according to a variant of the embodiment.

[0042] This is a schematic cutaway representation of a methane tanker including a ship tank and a terminal for loading / unloading this tank.

[0043] By convention, a position closer to the inside of the tank will be called "on" or "above," and a position closer to the supporting structure will be called "under" or "below," regardless of the tank wall's orientation relative to Earth's gravity. Similarly, an element closer to the inside of the tank will be called "upper" or "internal," and an element closer to the supporting structure will be called "lower" or "external."

[0044] A sealed and thermally insulated tank 71 will be described later, and in particular a connecting beam for such a tank 71.

[0045] Tank 71, integrated into a ship's hull for example, has a polyhedral shape. For example, tank 71 may include a bottom wall, a ceiling wall, a forward cofferdam wall, a rear cofferdam wall, two transverse walls, and possibly lower and / or upper chamfer walls.

[0046] The general structure of such a tank 71 is well known. We will therefore only describe one wall area of ​​the tank, it being understood that all the walls of the tank may have a similar general structure.

[0047] In relation to this, we now describe the multilayer structure of a tank wall, in the example a first horizontal tank wall 1 (the bottom or ceiling wall) according to one embodiment. The first tank wall 1 comprises, in the direction of the tank thickness, from the outside to the inside, a secondary thermally insulating barrier 6 resting against a load-bearing wall 5, a secondary airtight membrane 7, a primary thermally insulating barrier 8 and a primary airtight membrane 9 intended to be in contact with the liquefied gas stored in the tank.

[0048] The primary thermal insulation barrier 8 and the secondary thermal insulation barrier 6 are each made up of insulating elements, for example, parallelepiped-shaped insulating panels 10 arranged in a regular pattern. Various techniques are known for manufacturing such thermal insulation elements. For example, each insulating panel 10 is formed as described in publication FR2877638. Each insulating panel 10 is held to the load-bearing wall 5 by means of anchoring devices, which can be made in numerous ways according to known techniques, for example, as described in publication FR2973098. The insulating panels 10 of the primary thermal insulation barrier 8 and the secondary thermal insulation barrier 6 support the primary membrane 9 and the secondary membrane 7, respectively.

[0049] In another, unillustrated embodiment, the primary thermally insulating barrier 8 and the secondary thermally insulating barrier 6 may comprise a plurality of insulating panels that are anchored to the supporting structure by means of anchoring devices, such as those described, for example, in document WO2014096600. The insulating panels are generally parallelepiped in shape and are arranged in parallel rows. Each insulating panel comprises a base plate, optionally an intermediate plate, and a cover plate that defines a support surface for the waterproof membrane. The plates are, for example, made of plywood. Each insulating panel also comprises one or more layers of insulating polymer foam sandwiched between the plates. The insulating polymer foam may, in particular, be a polyurethane-based foam, optionally reinforced with fibers.The cover plate may have parallel grooves. The grooves have a shape roughly resembling an inverted T to accommodate a wing of the welding supports.

[0050] The secondary membrane 7 and primary membrane 9 are, for example, made up of a series of parallel metal plates called struts 11 with raised edges, which are arranged alternately with elongated weld supports 12. The struts 11 and weld supports 12 are made of an alloy with a low coefficient of expansion. The struts 11 and weld supports 12 of the secondary membrane 7 are, for example, made of a high-manganese iron alloy whose coefficient of expansion is typically on the order of 7.10 -6 at 10.10 -6 K -1The strakes 11 and the weld supports 12 of the primary membrane 9 are, for example, made of an iron and nickel alloy with a coefficient of expansion between 1.2 x 10 -6 and 2.10 -6 K -1 . The membranes, secondary 7 and primary 9, typically have a thickness between 0.5 and 1.0 mm, and preferably 0.7 mm.

[0051] In another embodiment not shown, the primary membrane 9 is made using corrugated stainless steel metal plates welded together.

[0052] In another embodiment not shown, the secondary membrane 7 and / or the primary membrane 9 may have strakes, each comprising at least two flat portions resting on an upper surface of the thermally insulating barrier and at least one corrugation projecting inwards towards the tank relative to the flat portions, the flat portions being located on either side of a corrugation. The strakes are juxtaposed and welded together watertight at the edges, for example by lap welding.

[0053] The strakes 11 have, in their widthwise direction, a flat central band resting against the insulating panels 10 and raised lateral edges. The raised edges extend substantially perpendicularly to the flat central band. The raised edges of the strakes 11 are welded watertight to the weld supports 12. Further details on the construction of such a membrane can be found in publication FR2968284.

[0054] We now describe in more detail a corner zone of the storage installation at the junction between two walls. This is a perspective view of a dihedral angle between the first tank wall 1 (in this example, a horizontal tank wall) and a second tank wall 2 inclined relative to the first tank wall 1 (in this example, with an inclination of 90°). The first tank wall 1 extends in a plane formed by a first direction D1 and a second direction D2. The second tank wall 2 extends in a plane perpendicular to the second direction D2. The first direction D1 and the second direction D2 are inclined relative to each other at an angle of 90°.

[0055] In the case represented in, the strakes 11 of the first wall of tank 1 extend along the second direction D2 while the strakes 11 of the second wall of tank 2 extend along the first direction D1.

[0056] At this point, the first load-bearing wall 4 of the first tank wall 1 and the second load-bearing wall 5 of the second tank wall 2 meet at a first edge 3 extending along the first direction. The secondary membrane 7 and primary membrane 9 of the two tank walls 1 and 2 are connected by an anchoring device that anchors the secondary watertight membrane 7 and primary membrane 9 to the first load-bearing wall 4 and to the second load-bearing wall 5.

[0057] More specifically, the secondary membranes 7 and primary membranes 9 of the first wall of tank 1 are anchored to the second load-bearing wall 5. Similarly, the secondary membranes 7 and primary membranes 9 of the second wall of tank 2 are anchored to the first load-bearing wall 4.

[0058] The anchoring device allows the tensile forces resulting from the thermal contraction of the secondary membranes 7 and primary membranes 9 to be absorbed. The anchoring device also allows the forces resulting from the deformation of the hull and in particular from the bending of the longitudinal wall of a ship corresponding to the beam effect of the ship.

[0059] The anchoring device consists of an elongated connecting beam 13 extending here along the first direction D1. The connecting beam 13 comprises a plurality of sections aligned with each other here in the first direction D1.

[0060] Each section comprises a hollow central core 17 with a parallelogram cross-section, here rectangular since in the example illustrated on the diagram the two load-bearing walls 4 and 5 form a right angle. Like the waterproof membranes, the connecting beam 13 can be made of an alloy with a low coefficient of expansion, for example, with sheets with a thickness between 1 and 3 mm, for example 1.5 mm. In one embodiment, the connecting beam 13 is made of Invar®, i.e., an iron and nickel alloy with a coefficient of expansion typically between 0.5 and 10⁻³. -6 and 2.10 -6 K -1 .

[0061] To hold the connecting beam 13 on each side of the edge 3, each of the load-bearing walls 5 has a primary anchor plate 19 and a secondary anchor plate 18. The distance from the secondary anchor plates 18 to the edge 3 corresponds to the thickness of the secondary thermally insulating barrier 6. The distance between the anchor plates 18 and 19 corresponds to the thickness of the primary thermally insulating barrier 8.

[0062] A specific area of ​​tank 71, namely the trihedral angle, will be described in more detail below. This is the area where three load-bearing walls intersect at a corner of the supporting structure. Within the trihedral angle, the connecting beam includes a trihedral segment 14, which allows for the connection between dihedral segments of several edges of tank 71. Such a trihedral segment 14 is illustrated in isolation in [reference].

[0063] Figures 2 and 3 represent more specifically the trihedral zone of a storage installation with the first tank wall 1, the second tank wall 2 and a third tank wall 15. In these figures, only the secondary membranes 7 of the first tank wall 1 and the third tank wall 15 have been represented with the secondary part of the connecting beam 13.

[0064] Thus, the third tank wall 15 is fixed to a third load-bearing wall. The first load-bearing wall 4 and the third load-bearing wall meet at a second edge 16 extending along the second direction D2. The second load-bearing wall 5 and the third load-bearing wall meet at a third edge 161 extending along a third direction D3. In the example shown, the third tank wall 15 and the first tank wall 1 form an angle of 135°, so that the third tank wall 15 corresponds to a chamfered wall.

[0065] As more clearly seen in the figure, the trihedral section 14 of the connecting beam 13 is made of flat metal sheets welded together to form: - a hollow central core 17 having a rectangular or square cross-section (in the case of a right-angled edge zone) whose side lengths are equal to the distance between the primary anchor plate 19 and the secondary anchor plate 18 of the load-bearing wall to which each side is parallel, the hollow central core 17 having a first portion of length 171 extending parallel to the first edge 3 and a second portion of length 172 extending parallel to the third edge 161, the hollow central core 17 comprising a first core wall 20, a second core wall 21 connected to the first core wall 20, a third core wall 22 connected to the first core wall 20, and a fourth core wall 23 connected to the second core wall 21 and to the third core wall 22,each of the core walls 20-23 extending over the first portion of length 171 and over the second portion of length 172; - connecting wings 24-29 projecting outwards from the central core towards the primary 9 and secondary 7 sealing membranes of the first, second and third tank walls 1, 2, 15, the connecting wings 24-29 allowing the secondary sealing membranes 7 of the tank walls 1, 2, 15 to be sealed as well as the primary sealing membranes 9 of the tank walls 1, 2, 15; - anchoring wings 30-35 projecting outwards from the central core 17 towards the load-bearing walls 4, 5 of the tank walls 1, 2, 15, the anchoring wings 30-35 being fixed to the load-bearing walls 4, 5.

[0066] The connecting wings comprise: - a first secondary connecting wing 24 projecting from the first portion of length 171 of the central core 17 away from the second load-bearing wall 5 and being fixed to the secondary watertight membrane 7 of the first tank wall 1, - a second secondary connecting wing 25 having first and second sections projecting from the first and second portions of length 171, 172 of the central core 17 away respectively from the first and third load-bearing walls 5 and being fixed to the secondary watertight membrane 7 of the second tank wall 2, - a third secondary connecting wing 26 projecting from the second portion of length 172 of the central core 17 away from the second load-bearing wall 5 and being fixed to the secondary watertight membrane 7 of the third tank wall 15,- a first primary connecting wing 27 projecting from the first portion of length 171 of the central core 17 away from the second load-bearing wall 5 and being fixed to the primary sealing membrane 9 of the first tank wall 1, - a second primary connecting wing 28 comprising first and second sections projecting from the first and second portions of length 171, 172 of the central core 17 away respectively from the first and third load-bearing walls 5 and being fixed to the primary sealing membrane 9 of the second tank wall 2, - a third primary connecting wing 29 projecting from the second portion of length 172 of the central core 17 away from the second load-bearing wall 5 and being fixed to the primary sealing membrane 9 of the third tank wall 15.,

[0067] The anchoring wings comprise: - a first secondary anchoring wing 30 projecting from the first length 171 of the central core 17 towards the second load-bearing wall 5, being aligned with the first secondary connecting wing 24, an outer edge 301 of the first secondary anchoring wing 30 being fixed to a secondary anchoring plate 18 of the second load-bearing wall 5, the first secondary anchoring wing 30 and the first secondary connecting wing 24 being located on either side of the first length 171 of the central core 17, - a second secondary anchoring wing 31 having first and second faces projecting from the first and second lengths 171, 172 of the central core 17 towards respectively the first and third load-bearing walls 5, being aligned with the second secondary connecting wing 25,the first section of the second secondary anchor wing 31 being fixed to a secondary anchor plate 18 of the first load-bearing wall 4 and the second section of the second secondary anchor wing 31 being fixed to a secondary anchor plate 18 of the third load-bearing wall, the second secondary anchor wing 31 and the second secondary connecting wing 25 being located on either side of the central core 17, - a third secondary anchor wing 32 projecting from the second length 172 of the central core 17 towards the second load-bearing wall 5, being aligned with the third secondary connecting wing 26, an outer edge 321 of the third secondary anchor wing 32 being fixed to a secondary anchor plate 18 of the second load-bearing wall 5, the third secondary anchor wing 32 and the third secondary connecting wing 26 being located on either side of the second length 172 of the central core 17,- a first primary anchoring wing 33 projecting from the first length 171 of the central core 17 towards the second load-bearing wall 5, being aligned with the first primary connecting wing 27, the first primary anchoring wing 33 being fixed to a primary anchoring plate 19 of the second load-bearing wall 5, the first primary anchoring wing 33 and the first primary connecting wing 27 being located on either side of the first length 171 of the central core 17, - a second primary anchoring wing 34 comprising first and second faces projecting from the first and second lengths 171, 172 of the central core 17 towards respectively the first and third load-bearing walls 5, being aligned with the second primary connecting wing 28,the first section of the second primary anchoring wing 34 being fixed to a primary anchoring plate 19 of the first load-bearing wall 4 and the second section of the second primary anchoring wing 34 being fixed to a primary anchoring plate 19 of the third load-bearing wall, the second primary anchoring wing 34 and the second primary connecting wing 28 being located on either side of the central core 17,- a third primary anchoring wing 35 projecting from the second portion of length 172 of the central core 17 towards the second load-bearing wall 5, being aligned with the third primary connecting wing 29, the third primary anchoring wing 35 being fixed to a primary anchoring plate 19 of the second load-bearing wall 5, the third primary anchoring wing 35 and the third primary connecting wing 29 being located on either side of the second portion of length 172 of the central core 17.,

[0068] In the unshown case of a primary waterproof membrane made with corrugated metal sheets, the connecting beam, and therefore the trihedral section, does not have primary connecting flanges or primary anchoring flanges. Furthermore, the central core 17 then consists of only two walls. This is referred to as a connecting half-beam.

[0069] As seen in (and applicable to the trihedral section 14), in order to ensure the continuity of the insulation at the connecting beam 13, insulating elements 36 are positioned inside the hollow central core 17 and between the anchoring wings 30-35 to form the secondary thermally insulating barrier 6 and the primary thermally insulating barrier 8 at the edges 3, 16, 161. The insulating elements 36 can be in the form of boxes filled with insulating materials such as glass wool or perlite or blocks of insulating foam for example.

[0070] As can be seen more particularly in figures 4 and 5, the first secondary anchoring wing 30 and the third secondary anchoring wing 32 are connected to each other by a connecting edge 37 parallel to the second edge 16.

[0071] The first secondary anchoring wing 30 and the third secondary anchoring wing 32 are inclined relative to each other at an angle of inclination between the first tank wall 1 and the third tank wall 15. The trihedral section 14 further includes a notch 38 at the level of the connecting edge 37 between the first secondary anchoring wing 30 and the third anchoring wing 32.

[0072] The notch 38 is made on the side of the outer edges 301, 321 of the first and third anchor wings 30, 32 so as to leave a space between the outer edge 301 of the first secondary anchor wing 30 and the outer edge 321 of the third anchor wing 32.

[0073] The notch 38 extends in the second direction D2 and comprises a first lateral edge 39 on the first secondary anchor flange 30, a second lateral edge 40 on the third secondary anchor flange 32, and a bottom 41 connecting the first lateral edge 39 to the second lateral edge 40. In the example, the bottom 41 has a rounded shape to avoid stress concentrations at corners. The notch measures between 70 and 150 mm along the direction D2.

[0074] Furthermore, as illustrated in particular, the first lateral edge 39 has a first rounded cutout 42 extending in the first direction D1. Similarly, the second lateral edge 40 has a second rounded cutout 43 extending in the third direction D3. The cutouts 42 and 43 distribute the stresses in the notch, providing flexibility in this area of ​​the trihedral segment 14. The rounded shape of the cutouts 42 and 43, as in the case of the base 41, prevents stress concentrations at the corners of the cutouts 42 and 43.

[0075] The first cutout 42 is made at a distance from the bottom 41 of the notch 38 and at a distance from the outer edge 301 of the first secondary anchoring wing 30 in the second direction D2. Similarly, the second cutout 42 is made at a distance from the bottom 41 of the notch 38 and at a distance from the outer edge 321 of the third secondary anchoring wing 32 in the second direction D2. Preferably, the cutouts 42, 43 are located approximately midway between the outer edge 301, 321 and the beginning of the curve of the bottom 41.

[0076] For example, in the case of a notch size 38 between the outer edge 301, 321 and the beginning of the bottom curve 41 of 70 mm, the cutouts 42 are approximately positioned between 20 and 40 mm from the outer edge 301, 321. The dimension of the notch 38 in direction D1 between the first lateral edge 38 and the connecting edge 37 is, for example, 25 mm. The dimension of the notch 38 in direction D3 between the second lateral edge 39 and the connecting edge 37 is, for example, 25 mm. The dimension of the first cutout 42 and the second cutout 43 can, for example, be between 15 and 30 mm in the second direction. The shape of the cutouts 42, 43 can be oblong.

[0077] In an embodiment illustrated in the figure, the first secondary anchoring wing 30 has a first opening 44 located near the first lateral edge 39 in the first direction D1, and, for example, located between the first cutout 42 and the bottom 41 in the second direction D2. The third secondary anchoring wing 32 has a second opening 45 located near the second lateral edge 40 in the third direction D3, and, for example, located between the second cutout 43 and the bottom 41 in the second direction D2. "Nearby in a direction" means that the distance is relatively small compared to the overall dimension of the element in that direction.

[0078] In another embodiment not shown, each of the first and third anchor wings 30, 32 could have a plurality of holes.

[0079] With reference to the, a cutaway view of a methane tanker 70 shows a sealed and thermally insulating tank 71 of generally prismatic shape mounted in the double hull 72 of the ship 70. The wall of the tank 71 comprises a primary sealed membrane intended to be in contact with the LNG contained in the tank, a secondary sealed membrane arranged between the primary sealed membrane and the double hull 72 of the ship 70, and two thermally insulating barriers arranged respectively between the primary sealed membrane and the secondary sealed membrane and between the secondary sealed membrane and the double hull 72.

[0080] As is known per se, loading / unloading pipelines 73 arranged on the upper deck of the ship can be connected, by means of suitable connectors, to a marine or port terminal to transfer a cargo of LNG to or from the tank 71.

[0081] Figure 75 represents an example of a marine terminal comprising a loading and unloading berth 75, a subsea pipeline 76, and an onshore facility 77. The loading and unloading berth 75 is a fixed offshore facility comprising a movable arm 74 and a tower 78 that supports the movable arm 74. The movable arm 74 carries a bundle of insulated flexible pipes 79 that can be connected to the loading / unloading pipelines 73. The steerable movable arm 74 accommodates all LNG carrier sizes. An unshown connecting pipeline extends inside tower 78. The loading and unloading station 75 allows the loading and unloading of the LNG carrier 70 from or to the onshore facility 77. This facility includes liquefied gas storage tanks 80 and connecting pipelines 81 linked by the subsea pipeline 76 to the loading or unloading station 75.The subsea pipeline 76 allows the transfer of liquefied gas between the loading or unloading station 75 and the onshore facility 77 over a long distance, for example 5 km, which allows the LNG carrier 70 to be kept a long distance from the coast during loading and unloading operations.

[0082] To generate the pressure necessary for the transfer of the liquefied gas, pumps on board the ship 70 and / or pumps equipping the land installation 77 and / or pumps equipping the loading and unloading station 75 are used.

[0083] Although the invention has been described in connection with several particular embodiments, it is clearly evident that it is by no means limited to them and that it includes all technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

[0084] The use of the verb "comporter", "comprendre" or "include" and its conjugated forms does not exclude the presence of other elements or steps than those stated in a claim.

[0085] In claims, any reference sign in parentheses shall not be interpreted as a limitation of the claim.

Claims

Liquefied gas storage installation comprising a load-bearing structure and a sealed and thermally insulated tank (71) supported by the load-bearing structure, the tank (71) comprising a first tank wall (1) fixed to a first load-bearing wall (4), a second tank wall (2) fixed to a second load-bearing wall (5) and a third tank wall (15) fixed to a third load-bearing wall, the first, second and third tank walls forming a trihedron; the first load-bearing wall (4) and the second load-bearing wall (5) meeting at a first edge (3) extending in a first direction (D1), the first load-bearing wall (4) and the third load-bearing wall meeting at a second edge (16) extending in a second direction (D2), the second load-bearing wall (5) and the third load-bearing wall meeting at a third edge (161) extending in a third direction (D3), the first edge (3),the second edge (16) and the third edge (161) meeting at a corner of the supporting structure, wherein each of the first, second and third tank walls comprises at least one watertight membrane (7) and at least one thermally insulating barrier (6) arranged between the watertight membrane (7) and one of the first, second and third supporting walls, wherein the watertight membrane (7) of each of the first and third tank walls comprises a plurality of strakes (11) each comprising at least one flat portion resting on an upper surface of the thermally insulating barrier (6) and at least one projecting portion protruding into the interior of the tank relative to the flat portion, the strakes (11) being juxtaposed and welded together watertight at the edges, the strakes (11) of the first tank wall (1) and the third tank wall (15) extending in the second direction (D2),in which the tank includes a connecting beam (13) connecting in a watertight manner the watertight membranes of the first, second and third tank walls, the connecting beam (13) comprising a trihedral section (14) running along the first edge (3) and the third edge (161) and being located at the corner of the supporting structure, the trihedral section (14) comprising: - a central core (17) having a first portion of length extending parallel to the first edge (3) and a second portion of length extending parallel to the third edge (161) and, - a first connecting wing (24) projecting from the first portion of length of the central core (17) away from the second supporting wall (5) and being fixed to the watertight membrane (7) of the first tank wall (1),- a second connecting wing (25) having first and second faces projecting from the first and second lengths of the central core (17) away from the first and third load-bearing walls respectively and being fixed to the watertight membrane (7) of the second tank wall (2), - a third connecting wing (26) projecting from the second length of the central core (17) away from the second load-bearing wall (5) and being fixed to the watertight membrane (7) of the third tank wall (15), - a first anchoring wing (30) projecting from the first length of the central core (17) towards the second load-bearing wall (5) and being aligned with the first connecting wing (24), an outer edge of the first anchoring wing (30) being fixed to a first anchoring plate of the second load-bearing wall (5),the first anchoring wing (30) and the first connecting wing (24) being situated on either side of the first length portion of the central core (17), - a third anchoring wing (32) projecting from the second length portion of the central core (17) towards the second load-bearing wall (5) and aligned with the third connecting wing (26), an outer edge of the third anchoring wing (32) being fixed to a second anchoring plate of the second load-bearing wall (5), the third anchoring wing (32) and the third connecting wing (26) being situated on either side of the second length portion of the central core (17), wherein the first anchoring wing (30) and the third anchoring wing (32) are connected to each other by a connecting edge (37) parallel to the second edge (16) and are inclined relative to each other of an angle of inclination between the first tank wall (1) and the third tank wall (15),in which the trihedral segment (14) has a notch (38) at the connecting edge (37) between the first anchoring wing (30) and the third anchoring wing (32), the notch (38) being made on the side of the outer edges of the first and third anchoring wings so as to leave a space between the outer edge of the first anchoring wing (30) and the outer edge of the third anchoring wing (32). Storage installation (1) according to claim 1, wherein the notch (38) extends in the second direction (D2) and comprises a first lateral edge (39) on the first anchoring wing (30), a second lateral edge (40) on the third anchoring wing (32) and a bottom (41) connecting the first lateral edge (39) to the second lateral edge (40), the bottom (41) having a rounded shape. Storage installation (1) according to claim 2, wherein the first lateral edge (39) has a first cutout (42) of rounded shape extending in the first direction (D1) and the second lateral edge (40) has a second cutout (43) of rounded shape extending in the third direction (D3). Storage installation (1) according to claim 3, wherein the first cut (42) is made at a distance from the bottom (41) of the notch (38) and at a distance from the outer edge of the first anchoring wing (30) in the second direction (D2) and the second cut (43) is made at a distance from the bottom (41) of the notch (38) and at a distance from the outer edge of the third anchoring wing (32) in the second direction (D2). Storage installation (1) according to claim 3 or claim 4, wherein the first anchoring wing (30) has a first orifice (44) located near the first lateral edge (39) in the first direction (D1), and preferably located between the first cutout (42) and the bottom (41) in the second direction (D2), and the third anchoring wing (32) has a second orifice (44) located near the second lateral edge (40) in the third direction (D3), and preferably located between the second cutout (43) and the bottom (41) in the second direction (D2). Storage installation (1) according to any one of claims 1 to 5, wherein the strakes (11) are made of an alloy having a coefficient of thermal expansion less than or equal to 10.10 -6 K -1 . Storage installation (1) according to any one of claims 1 to 6, wherein the strakes (11) are made of a high manganese iron alloy having a coefficient of thermal expansion between 6 and 10.10 -6 K -1 , for example, in the order of 7.10 -6 K -1 or in an iron and nickel alloy with a coefficient of expansion between 0.5 x 10 -6 and 2.10 -6 K -1 . Storage installation (1) according to any one of claims 1 to 7, wherein the connecting beam (13) is made of an iron and nickel alloy having a coefficient of expansion between 0.5.10 -6 and 2.10 -6 K -1 . Storage installation (1) according to any one of claims 1 to 8, wherein the strakes (11) of the second tank wall (2) extend in the first direction (D1). Vessel (70) for the transport of a cold liquid product, the vessel comprising a double hull (72) and a storage facility according to any one of claims 1 to 9, the double hull comprising the load-bearing structure of the storage facility. Transfer system for a cold liquid product, the system comprising a vessel (70) according to claim 10, insulated pipes (73, 79, 76, 81) arranged to connect the vessel's tank (71) to a floating or land-based storage facility (77) and a pump to drive a flow of cold liquid product through the insulated pipes from or to the floating or land-based storage facility to or from the vessel's tank. Method of loading or unloading a ship (70), in which a cold liquid product is conveyed through insulated pipes (73, 79, 76, 81) from or to a floating or land-based storage facility (77) to or from the tank (71) of the ship (70) according to claim 10.

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