Waterproof and thermally insulating tank

Abstract

The invention relates to a sealed and thermally insulating tank (71) for storing liquefied gas, in which the tank wall (1) comprises a thermally insulating barrier (6) and a sealed membrane (8), in which the thermally insulating barrier (6) comprises first grooves (13) and second grooves (14), thermal protection strips (21) being arranged in the first grooves (13) and the second grooves (14), in which the sealed membrane (8) comprises four corrugated metal plates (16), in which the tank wall (1) comprises a metal sealing plate (22), the underside of the metal sealing plates being glued at one of the groove nodes, in which the corner region (19) of the corrugated metal plates (16) is welded to the upper side of the metal sealing plates,the upper face of the metal sealing plates comprising a covered portion (42) being located under the corrugated metal plates (16) and an uncovered portion (43) being intended to be in contact with the liquefied gas. Figure for the abstract: 2,

Description

Title of the invention: Sealed and thermally insulating tank Technical field

[0001] The invention relates to the field of sealed and thermally insulating tanks, with sealed membranes and to the method for mounting such a sealed membrane. In particular, the invention relates to the field of sealed and thermally insulating tanks for the storage and / or transport of liquefied gas at low temperature, such as tanks for the transport of Liquefied Petroleum Gas (also called LPG) having for example a temperature between -50°C and 0°C, or for the transport of 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 intended for the transport of liquefied gas or for receiving liquefied gas used as fuel for the propulsion of the floating structure. Technological background

[0002] Document US4021982 discloses a sealed and thermally insulating tank for storing liquefied gas comprising on each of the tank walls a multi-layer structure composed of a secondary thermally insulating barrier, a secondary sealed membrane, a primary thermally insulating barrier and a primary sealed membrane intended to be in contact with the liquefied gas. The primary sealed membrane is a corrugated sealed membrane which comprises a plurality of corrugated metal plates welded to each other.

[0003] In a running part of a tank wall, the corrugated metal plates are welded to anchoring strips or anchoring plates which are themselves anchored to the insulating panels of the thermally insulating barrier.

[0004] This document describes in particular the mounting of corrugated metal plates to anchoring plates. Indeed, in US4021982, the corrugated metal plates are welded to anchoring systems which are themselves securely fixed to the primary thermally insulating barrier. The anchoring system comprises a square metal plate onto which the corners of four adjacent corrugated metal plates are welded, and an anchoring pin onto which the square metal plate is welded and which is fixed to the insulating panel in a counterbore using a pin holder.

[0005] This type of fixing facilitates the assembly of corrugated metal plates and allows certain positioning tolerances of the corrugated metal plates because the square metal plate also has a sealing function.

[0006] However, in special areas of the tank, particularly near a opening for the passage of a pipe, it is advantageous to limit the fixings of the waterproof membrane to the thermally insulating barrier in order to allow the waterproof membrane to move or deform more freely. In this case, however, care must be taken to ensure the waterproofing of the membrane, particularly at the corner areas.

[0007] The attachment of the waterproof membrane of US4021982 does not sufficiently allow the waterproof membrane to move or deform more freely.

[0008] Document WO2019002076 thus provides a mounting method in which the metal plates have corner areas of different designs from each other and are assembled to each other in a particular order in order to ensure that sealing is achieved at the intersections of the metal plates.

[0009] Such a manufacturing method has the advantage of not requiring any additional parts, other than the corrugated metal plates, to ensure sealing at the intersection of the metal plates. However, despite these advantages, this method is not entirely satisfactory. In particular, this method involves the need for a very large number of metal plates of different shapes and increases the risk of errors during assembly. Summary of the invention

[0010] One idea underlying the invention is to provide a waterproof membrane which makes it possible to limit the attachment of the waterproof membrane to the thermally insulating barrier, particularly in special areas of the tank.

[0011] Another idea underlying the invention is to facilitate the assembly of the waterproof membrane.

[0012] According to one embodiment, the invention provides a sealed and thermally insulating tank for storing liquefied gas, the sealed and thermally insulating tank being integrated into a supporting structure, the tank comprising at least one tank wall, wherein the tank wall comprises a thermally insulating barrier fixed directly or directly to the supporting structure and a sealed membrane supported by the thermally insulating barrier and intended to be in contact with the liquefied gas, wherein the thermally insulating barrier comprises insulating panels juxtaposed with each other, the insulating panels comprising cover plates, the thermally insulating barrier comprising first grooves and second grooves made on the cover plates of the insulating panels, the first grooves extending parallel to each other in a first direction and the second grooves extending parallel to each other in a second direction, the second direction being perpendicular to the first direction, a said first groove intersecting a said second groove at a groove node, wherein the tank wall comprises a metal sealing plate, the metal sealing plate comprising an upper face and a lower face, the lower face of the metal sealing plate being bonded to the thermally insulating barrier in said groove node, first and second thermal protection strips being arranged in said first groove and said second groove outside said groove node, wherein the waterproof membrane comprises at least three corrugated metal plates which are adjacent to the metal sealing plate, each corrugated metal plate being rectangular in shape and comprising a first edge extending in the first direction, and a second edge extending in the second direction, wherein the first edges of the corrugated metal plates are welded two by two by overlapping at the level of the first thermal protection strip and the second edges of the corrugated metal plates are welded two by two by overlapping at the level of the second thermal protection strip, wherein at least two of said corrugated metal plates comprise a corner area welded to the upper face of the metal sealing plate, the corner area connecting said first edge and said second edge, said at least two corrugated metal plates having the first edge arranged in line with said first thermal protection strip and the second edge arranged in line with said second thermal protection strip, the upper face of the metal sealing plate comprising a covered portion and an uncovered portion complementary to the covered portion, the covered portion being located under the at least three corrugated metal plates and the uncovered portion being intended to be in contact with the liquefied gas.

[0013] According to one embodiment, the invention provides a method for mounting a sealed membrane on a tank wall of a sealed and thermally insulating tank for the storage of liquefied gas, the sealed and thermally insulating tank being integrated into a supporting structure, in which the mounting method comprises the following steps: - providing a tank wall comprising a thermally insulating barrier fixed to the supporting structure, the thermally insulating barrier comprising insulating panels juxtaposed to each other and comprising cover plates, the thermally insulating barrier comprising first grooves and second grooves made on the cover plates of the insulating panels, the first grooves extending parallel to each other in a first direction and the second grooves extending parallel to each other in a second direction, the second direction being perpendicular to the first direction, a said first groove intersecting a said second groove at a groove node, first and second thermal protection strips being arranged respectively in said first groove and said second groove, - cutting the first and second thermal protection strips at the level of said groove node, - provide a metal sealing plate comprising an upper face and a lower face, - glue the lower face of the metal sealing plate at the level of said groove node to the cover plate, - provide four corrugated metal plates intended to form a waterproof membrane for the tank wall, each metal plate being rectangular in shape and having a first edge and a second edge, the first edge joining the second edge at a corner area, - arranging and welding the four corrugated metal plates so that each first edge is arranged in line with one of the first grooves, each second edge is arranged in line with one of the second grooves, the first edges of the corrugated metal plates being welded two by two by overlapping in line with the first thermal protection strip and the second edges of the corrugated metal plates being welded two by two by overlapping in line with the second thermal protection strip, the corner area of ​​the corrugated metal plates being welded to the upper face of the metal sealing plate, the upper face of the metal sealing plate comprising a covered portion and an uncovered portion complementary to the covered portion, the covered portion being located under the four corrugated metal plates and the uncovered portion being intended to be in contact with the liquefied gas.

[0014] Thanks to these characteristics, the sealing plate makes it possible, on the one hand, to facilitate assembly by having a sealing role allowing a more flexible arrangement of the corrugated metal plates. In addition, the design of the sealing plate is simple and its pre-fixing to the thermally insulating barrier is easy since it involves simple gluing. Finally, the gluing is not designed to last during use of the tank and only has a function of pre-fixing the sealing plate so that after detachment of the sealing plate after welding of the corrugated metal plates on the sealing plate, the waterproof membrane is free to move or deform with respect to the thermally insulating barrier at the sealing plate.

[0015] According to embodiments, such a tank or such a method may comprise one or more of the following characteristics.

[0016] According to one embodiment, the waterproof membrane comprises three metal plates corrugated metal plates which are adjacent to the metal sealing plate, wherein two of said corrugated metal plates have a corner area welded to the upper face of the metal sealing plate, said two corrugated metal plates having the first edge arranged in line with said first thermal protection strip and the second edge arranged in line with said second thermal protection strip, and wherein the first edge of a third of said corrugated metal plates passes through the upper face of the metal sealing plate, the covered portion being located under said three corrugated metal plates.

[0017] According to one embodiment, the waterproof membrane comprises four corrugated metal plates which are adjacent to the metal sealing plate, wherein each corrugated metal plate comprises a corner area welded to the upper face of the metal sealing plate, each corrugated metal plate having the first edge arranged in line with said first thermal protection strip and the second edge arranged in line with said second thermal protection strip, the covered portion being located under the four corrugated metal plates.

[0018] According to one embodiment, the tank wall and the supporting structure are crossed by a pipe, the waterproof membrane comprising a closing plate located all around the pipe, the closing plate being provided with an orifice which is crossed by the pipe, at least one of said corrugated metal plates having an edge connected in a sealed manner to the closing plate.

[0019] According to one embodiment, the closing plate can be made in one piece or by assembling a plurality of plates.

[0020] According to one embodiment, the tank wall and the supporting structure are interrupted locally so as to delimit an opening intended to be crossed by a pipe, said insulating panels being opening insulating panels adjacent to the opening.

[0021] Indeed, in this area, the waterproof membrane is designed in a particular way and is further designed to be welded to the pipe during the manufacture of the tank, thus creating a special area where the waterproof membrane cannot move freely, in the same way as in the tank corners, compared to the current part of a tank wall. Therefore, the fixing of the corrugated metal plates to the metal sealing plate makes it possible to limit the fixing of the waterproof membrane to the thermally insulating barrier.

[0022] According to one embodiment, the first groove and the second groove each comprise a groove bottom and two opposite edges spaced apart by a groove width, the first and second thermal protection strips resting against the groove bottom. groove and the metal sealing plate being arranged in the groove node at a distance from the edges of the first groove and the edges of the second groove.

[0023] Thus, there is a spacing between the groove edges and the sealing plate allowing relative movement of the waterproof membrane with respect to the thermally insulating barrier in the plane of the waterproof membrane.

[0024] According to one embodiment, the groove width of the first groove is equal to the groove width of the second groove.

[0025] According to one embodiment, the metal sealing plate has a dimension in the first direction less than or equal to the groove width of the second groove, and the metal sealing plate has a dimension in the second direction less than or equal to the groove width of the first groove.

[0026] Thus, the dimensions of the metal sealing plate are relatively small, de facto limiting the fixing of the waterproof membrane to the thermally insulating barrier.

[0027] According to one embodiment, the metal sealing plate has a dimension in the first direction strictly less than the groove width of the second groove, and the metal sealing plate has a dimension in the second direction strictly less than the groove width of the first groove.

[0028] According to one embodiment, the metal sealing plate is rectangular in shape, two first sides of the metal sealing plate extending in the first direction and two second sides of the metal sealing plate extending in the second direction, the first side joining the second side at a corner, the corners being chamfered.

[0029] Thus, the chamfered corners and / or dimensions of the metal sealing plate strictly smaller than those of the grooves contribute to the creation of a space between the groove edges and the sealing plate in order to allow relative movement of the waterproof membrane with respect to the thermally insulating barrier in the plane of the waterproof membrane.

[0030] According to one embodiment, the corner areas of the corrugated metal plates are chamfered.

[0031] According to one embodiment, the tank wall is a ceiling wall, the sealed and thermally insulating tank comprising the ceiling wall, a bottom wall opposite the ceiling wall in a height direction, and one or more side walls connecting the bottom wall to the ceiling wall.

[0032] According to one embodiment, the tank wall is a bottom wall, the sealed and thermally insulating tank comprising the bottom wall, a ceiling wall opposite the ceiling wall in a height direction, and one or more side walls connecting the bottom wall to the ceiling wall.

[0033] According to one embodiment, the thermally insulating barrier is a primary thermally insulating barrier and the sealed membrane is a primary sealed membrane, the tank wall further comprising a secondary thermally insulating barrier arranged between the primary thermally insulating barrier and the supporting structure, and a secondary sealed membrane arranged between the secondary thermally insulating barrier and the primary thermally insulating barrier.

[0034] According to one embodiment, before the step of bonding the metal sealing plate, the method comprises the step of arranging a template in said groove node, the template comprising a border at least partially surrounding a housing, the housing having a shape at least partially complementary to the metal sealing plate, and in which the step of bonding the metal sealing plate is carried out by arranging the metal sealing plate in the housing of the template, the template preferably being removed after the step of bonding the metal sealing plate.

[0035] Thus, the template helps to precisely position the sealing plate in the groove node, which advantageously prevents the sealing plate from being glued too close to the groove edges.

[0036] According to one embodiment, before the step of arranging and welding the corrugated metal plates, the method comprises the step of marking the metal sealing plate with positioning marks, the positioning marks being configured to indicate the position of the corner areas of the corrugated metal plates to be arranged.

[0037] Thus, the presence of a metallic element, here the metallic sealing plate, at the level where the corner zones must be arranged, makes possible a marking step facilitating the assembly of the waterproof membrane.

[0038] According to one embodiment, each metal plate comprises at least one first corrugation extending in the first direction and at least one second corrugation extending in the second direction.

[0039] According to one embodiment, the first and second thermal protection strips are made of a composite material comprising an aluminum sheet and glass fibers.

[0040] Thus, the thermal protection strips have a material whose thermal properties make it possible to protect the cover plate from the heat of welding. However, this type of material makes positioning marking difficult and imprecise.

[0041] According to one embodiment, the corrugated metal plates and / or the metal sealing plates are made of stainless steel.

[0042] According to one embodiment, the cover plate is made of plywood. or composite material.

[0043] According to one embodiment, the tank wall comprises a layer of adhesive resin between the metal sealing plate and the cover plate.

[0044] According to one embodiment, the lower face of the metal sealing plate is bonded to the thermally insulating barrier in said groove node using an adhesive resin, the adhesive resin being configured to support a load greater than or equal to the weight of the metal sealing plate at ambient temperature during a manufacturing time of the sealed and thermally insulating tank.

[0045] Thus, the adhesive resin is chosen so that its bonding properties make it possible to hold the metal sealing plate in position, taking the most unfavorable case, namely the ceiling wall, during the assembly of the metal sealing membrane. However, it is not necessary for this adhesive resin to continue to hold the metal sealing plate after the assembly of the metal sealing membrane. This adhesive resin therefore does not have sufficient bonding properties to hold the metal sealing plate in position at cryogenic temperatures when using the sealed and thermally insulating tank.

[0046] According to one embodiment, the adhesive resin is configured to support a load strictly less than the weight of the metal sealing plate at cryogenic temperature for a predefined time.

[0047] Such a tank may be part of a land-based storage facility, for example for storing LNG, or may be installed in a floating, coastal, or deep-water structure, including an LNG 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.

[0048] According to one embodiment, a ship for transporting a cold liquid product comprises a double hull and a aforementioned tank arranged in the double hull.

[0049] According to one embodiment, the invention also provides a transfer system for a cold liquid product, the system comprising the aforementioned ship, insulated pipes arranged to connect the tank installed in the hull of the ship to a floating or land-based storage facility and a pump for driving a flow of cold liquid product through the insulated pipes from or to the floating or land-based storage facility to or from the tank of the ship.

[0050] According to one embodiment, the invention also provides a method for loading or unloading such 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 ship's tank. Brief description of the figures

[0051] 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.

[0052] [Fig.l] represents a schematic sectional view of a tank wall.

[0053] [Fig.2] is a partial front view of a ceiling wall of a tank according to a embodiment, before fixing the primary waterproof membrane.

[0054] [Fig.3] is a view of detail III of [Fig.2] showing a groove node after the thermal protection strips have been laid.

[0055] [Fig.4] is a view of detail III of [Fig.2] showing a groove node after cutting the thermal protection strips.

[0056] [Fig.5] is a perspective view of detail III of [Fig.2] showing a groove node after a template has been arranged.

[0057] [Fig.6] is a perspective view of detail III of [Fig.2] showing a groove node after bonding the metal sealing plate to the cover plate before removal of the template.

[0058] [Fig.7] is a perspective view of detail III of [Fig.2] showing a groove node after bonding the metal sealing plate to the cover plate after removal of the template.

[0059] [Fig.8] is a partial front view of a ceiling wall of a tank according to one embodiment, before fixing the primary waterproof membrane and during a marking step for positioning the corrugated metal plates.

[0060] [Fig.9] is a partial front view of a ceiling wall of a tank according to one embodiment, after fixing the primary waterproof membrane.

[0061] [Fig. 10] is a view of detail III of [Fig. 2] showing a groove node after the step of welding the corrugated metal plates, the corrugated metal plates being shown in transparency.

[0062] [Fig. 11] is a schematic cutaway representation of an LNG carrier vessel comprising a ship tank and a terminal for loading / unloading this tank. Description of the embodiments

[0063] A sealed and thermally insulating membrane tank 71 for storing liquefied gas will be described below with reference to the figures. The tank 71 comprises a plurality of tank walls 1 connected to each other and fixed to a supporting structure 2. The tank 71 may, for example, be polyhedral in shape or cylindrical in shape with a circular base.

[0064] [Fig.l] schematically represents the structure of a tank wall 1.

[0065] Each tank wall 1 has a multi-layer structure comprising, from the outside to the inside, a secondary thermally insulating barrier 3 comprising secondary insulating panels 4 and resting against the supporting structure 2, a secondary sealed membrane 5 resting against the secondary thermally insulating barrier 3, a primary thermally insulating barrier 6 comprising primary insulating panels 7, 12 and resting against the secondary sealed membrane 5 and a primary sealed membrane 8 resting against the primary thermally insulating barrier 6 and intended to be in contact with the liquefied gas contained in the tank 1. The primary sealed membrane 8 defines an internal space intended to receive the liquefied gas. By way of example, such membrane tanks are described in particular in patent applications WO2019239048, WO14057221, and FR2691520.

[0066] Each primary insulating panel 7, 12 comprises a cover plate 10, an insulating lining 11 such as a block of insulating foam, and optionally a bottom plate (not shown).

[0067] The liquefied gas intended to be stored in the tank 71 may in particular be a liquefied natural gas (LNG), that is to say a gas mixture comprising mainly methane and one or more other hydrocarbons. The liquefied gas may also be ethane or a liquefied petroleum gas (LPG), that is to say a mixture of hydrocarbons resulting from the refining of petroleum comprising essentially propane and butane.

[0068] [Fig.2] partially represents a ceiling wall 1 of the tank 71. In this figure, the secondary thermally insulating barrier 3, the secondary waterproof membrane 5 and the primary thermally insulating barrier 6 have already been mounted on the supporting structure 2 so that only the primary thermally insulating barrier 6 can be seen. The ceiling wall 1 and the supporting structure 2 are here locally interrupted several times so as to delimit three openings 9. The openings 9 are intended to be crossed by pipes (not shown) such as a loading pipe and an unloading pipe. The primary thermally insulating barrier 6 comprises a plurality of primary insulating panels 7, 12 juxtaposed with each other.

[0069] The primary insulating panels 7, 12 comprise common primary insulating panels 7 and opening primary insulating panels 12 which are located adjacent to an opening 9.

[0070] The primary thermally insulating barrier 6 comprises first grooves 13 and second grooves 14 made on the cover plates 10 of the primary insulating panels 7, 12. The first grooves 13 extend parallel to each other in a first direction and the second grooves 14 extend parallel to each other in a second direction. ably to each other in a second direction which is perpendicular to the first direction. The first grooves 13 intersect the second grooves 14 at groove nodes 15.

[0071] The primary waterproof membrane 7, more particularly shown in [Fig.9], comprises corrugated metal plates 16 of rectangular shape. Each corrugated metal plate 16 comprises two first edges 17 parallel to each other and extending in the first direction, two second edges 18 parallel to each other and extending in the second direction, each first edge joining a second edge at a corner zone 19.

[0072] When assembling the corrugated metal plates 16, the first edges 17 are arranged in line with the first grooves 13 and the second edges are arranged in line with the second grooves 14. The corner zones 19 are arranged in line with the groove nodes 15. Each corrugated metal plate comprises at least one first corrugation (not shown) extending in the first direction and at least one second corrugation (not shown) extending in the second direction. The first corrugations and the second corrugations are intentionally not illustrated in [Fig.9] in order to more easily distinguish the assembly of the different corrugated metal plates with each other.

[0073] Returning to [Fig. 2], the current primary insulating panels 7 are equipped with metal anchoring strips 20 fixed to the cover plate 10 inside the first grooves 13 and the second grooves 14, in particular at the groove nodes 15. It is to these metal anchoring strips 20 that the corrugated metal plates 16 are welded and anchored to the primary thermally insulating barrier 6

[0074] The primary opening insulating panels 12 are themselves equipped with thermal protection strips 21 which are arranged in the first grooves 13 and the second grooves 14.

[0075] In order to maintain freedom from deformation, the primary waterproof membrane 8 is not anchored using the metal anchoring strips 20 near the openings 9 and therefore at the level of the primary opening insulating panels 12.

[0076] Thus, above the primary opening insulating panels 12, the first edges 17 and the second edges 18 of the corrugated metal plates 16 are overlap-welded respectively to the first edges 17 and to the second edges 18 of the adjacent corrugated metal plates 16 without being anchored to the primary thermally insulating barrier 6. The corner zones 19 are for their part welded to an upper face of a metal sealing plate 22 at a groove node 15. The metal sealing plates 22 and their function will be described more particularly hereinafter.

[0077] Figures 3 to 7 represent more particularly the different stages allowing to position the metal sealing plates 22 in the groove nodes 15.

[0078] [Fig. 3] represents the initial state in which the thermal protection strips 21 of the first groove 13 and the second groove 14 intersect at the groove node 15. The thermal protection strips 21 are then cut, as illustrated in [Fig. 4], at the groove node 15 so as to make a groove bottom of the groove node 15 visible.

[0079] A template 23 is then arranged at the groove node 15, as shown in [Fig. 5]. This template 23 comprises a border 24 partially surrounding a housing 25. The border 24 has a plurality of branches connected to each other and which are arranged in the different grooves 13, 14 making up the groove node 15 so as to allow centering of the housing 25 on the groove node 15. The housing 25 is made so as to have a shape partially complementary to the metal sealing plate 22 in order to assist in its positioning and centering on the groove node 15.

[0080] The metal sealing plate 22 is positioned in the housing 25 and is glued to the groove node 15, as visible in [Fig.6]. Once the metal sealing plate 22 is glued, the template is removed as shown in [Fig.7]. The gluing can be carried out by placing a layer of glue on the groove node 15 or the lower face of the metal sealing plate 22 or by gluing a double-sided adhesive strip to the lower face of the metal sealing plate 22.

[0081] As seen in [Fig.7], the metal sealing plate 22 is rectangular in shape, preferably square, and has two first sides 26 extending in the first direction after bonding and two second sides 27 extending in the second direction after bonding. The first side 26 joins the second side 27 at a corner 28 which, in the example shown, is chamfered.

[0082] The metal sealing plate 22 has a dimension in the first direction smaller than the dimension of the second groove 14 in the first direction, and has a dimension in the second direction smaller than the dimension of the first groove 13 in the second direction. Thus, as shown in [Fig.7], thanks to these dimensions, its shape and the centering achieved by the template, the metal sealing plate 22 is arranged at a distance from the edges of the first groove 13 and the edges of the second groove 14 forming the groove node 15.

[0083] The metal sealing plate 22 thus comprises a lower face glued to the cover plate 10 and an upper face intended to be welded to the corrugated metal plates 16.

[0084] Following the bonding of the metal sealing plates and in order to assist in the posi- tion of the corrugated metal plates 16, a marking step is provided as schematically illustrated in [Fig.8]. Indeed, during this step, positioning marks 29 are drawn precisely on the metal sealing plates 22 in order to measure and indicate where the different corrugated metal plates will be positioned.

[0085] [Fig.9] represents the ceiling wall 1 after welding the corrugated metal plates 16 so as to form the primary waterproof membrane 8, without the illustration of the first corrugations and the second corrugations in order to facilitate the reading of this figure.

[0086] The corrugated metal plates 16 are thus arranged so that their first edge 17 is located in line with one of the first grooves 13 and their second edge 18 is located in line with one of the second grooves 14. The metal plates are, as they are placed on the primary thermally insulating barrier 6, welded together by overlapping and welded by their corner zone 19 to one of the metal sealing plates 21 when it is a primary insulating opening panel 12. The first edges 17 and the second edges 18 of the corrugated metal plates 16 are thus welded by overlapping respectively to the first edges 16 and to the second edges 17 of the adjacent corrugated metal plates 16.

[0087] All around the openings 9, flat closing plates 30 are arranged at each opening 9. The closing plates 30 have orifices 31 of the same shape as the corresponding opening 9. The closing plates 30 are intended to be welded via, for example, a collar to the corresponding pipe. The corrugated metal plates 16 located all around the closing plate 30 are welded to the closing plate 30. The corrugations of these corrugated metal plates 16 which are interrupted by the closing plate 30 are closed using a corrugation cap 32 which is also welded to the closing plate 30.

[0088] In another embodiment not shown, the closure plates 30 may be corrugated so that it is not necessary to provide a corrugation cap to close the corrugations.

[0089] In order to maintain a certain flexibility of the primary waterproof membrane 8, certain corrugations are deflected, using a deflection system 33 welded to the junction between two corrugated metal plates 16, from their original direction so as not to be interrupted by a closing plate 30. If the corrugations are not shown, the deflection systems 33 and the corrugation caps 32 are clearly shown in [Fig.9] so that it is possible to deduce the position of certain corrugations.

[0090] As described above, the assembly of the primary waterproof membrane 9 is carried out by repeated sequences of arranging a corrugated metal plate 16 and welding this corrugated metal plate to the adjacent corrugated metal plates 16 and to the metal sealing plates 22.

[0091] Such a sequence is notably illustrated schematically by [Fig. 10] at the junction between four corrugated metal plates 16 at the level of a metal sealing plate 22, and therefore above an opening insulating panel 12. In this figure, the four corrugated metal plates, namely the first plate 34, the second plate 35, the third plate 36 and the fourth plate 37 are illustrated in transparency so as to distinguish the metal sealing plate 22, the first groove 13, the second groove 14, the groove node 15 and the cover plate 10.

[0092] In this illustrated example, the first plate 34 is firstly arranged so that one of its first edges 17 is located in line with the first groove 13, one of its second edges 18 is located in line with the second groove 14, and one of the corner zones 19 is located in line with the groove node 15 and the metal sealing plate 22. The corner zone 19 is then welded using a first weld bead 38 to the metal sealing plate 22.

[0093] The second plate 35 and the third plate 36 are arranged adjacent to the first plate 34 such that a first edge 17 of the second plate 35 is overlap welded to a first edge 17 of the first plate 34 and a second edge 18 of the third plate 36 is overlap welded to a second edge of the first plate 34. The corner area 19 of the second plate 35 is welded with a second weld bead 39 partly to the metal sealing plate 22 and partly to the corner area 19 of the first plate 34. The corner area 19 of the third plate 36 is welded with a third weld bead 40 partly to the metal sealing plate 22 and partly to the corner area 19 of the first plate 34.

[0094] The fourth plate 37 is finally arranged adjacent to the second plate 35 and the third plate 36 such that a first edge 17 of the fourth plate 37 is overlap welded to a first edge 17 of the third plate 36 and a second edge 18 of the fourth plate 37 is overlap welded to a second edge of the second plate 35. The corner area 19 of the fourth plate 37 is welded using a fourth weld bead 41 partly to the metal sealing plate 22, partly to the corner area 19 of the second plate 35, and partly to the corner area 19 of the third plate 36.

[0095] This welding sequence is described in more detail in document US4021982. This is an example of a welding sequence. Other sequences could be carried out in order to result in welded corrugated metal plates 16. on a metal sealing plate 22 in a sealed manner.

[0096] The metal sealing plate 22 thus has an upper face comprising a covered portion 42 and an uncovered portion 43 illustrated in [Fig. 10]. The covered portion 42 thus corresponds to the portion of the upper face which is under the four plates 34, 35, 36, 37. The uncovered portion 43 is intended to be in contact with the liquefied gas.

[0097] As visible in [Fig. 10], the uncovered portion 43 is thus continuously surrounded by a quadrilateral of weld beads whose sides are formed by each of the first, second, third and fourth weld beads 38, 39, 40, 4L. Thus, it is the set of corrugated metal plates and the uncovered portions 43 of the metal sealing plates 22 which form the primary waterproof membrane 8.

[0098] With reference to [Fig. 11], a cutaway view of an LNG carrier ship 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.

[0099] 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 LNG from or to the tank 71.

[0100] [Fig. 11] shows an example of a maritime terminal comprising a loading and unloading station 75, an underwater pipeline 76 and an onshore installation 77. The loading and unloading station 75 is a fixed offshore installation comprising a mobile arm 74 and a tower 78 which supports the mobile arm 74. The mobile arm 74 carries a bundle of insulated flexible pipes 79 which can be connected to the loading / unloading pipelines 73. The orientable mobile arm 74 adapts to all sizes of LNG carriers. A connecting pipe, not shown, extends inside the tower 78. The loading and unloading station 75 allows the loading and unloading of the LNG 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 LNG carrier 70 at high speed. distance from the coast during loading and unloading operations.

[0101] To generate the pressure necessary for the transfer of the liquefied gas, pumps on board the ship 70 and / or pumps equipping the onshore installation 77 and / or pumps equipping the loading and unloading station 75 are used.

[0102] 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.

[0103] The use of the verb “comprise”, “comprise” or “include” and its conjugated forms does not exclude the presence of other elements or other steps than those set out in a claim.

[0104] In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims

Claims

1. A sealed and thermally insulating tank (71) for storing liquefied gas, the sealed and thermally insulating tank (71) being integrated into a supporting structure (2), the tank comprising at least one tank wall (1), wherein the tank wall (1) comprises a thermally insulating barrier (6) fixed directly or directly to the supporting structure (2) and a sealed membrane (8) supported by the thermally insulating barrier (6) and intended to be in contact with the liquefied gas, wherein the thermally insulating barrier (6) comprises insulating panels (7, 12) juxtaposed with each other, the insulating panels comprising cover plates (10), the thermally insulating barrier (6) comprising first grooves (13) and second grooves (14) made on the cover plates (10) of the insulating panels,the first grooves (13) extending parallel to each other in a first direction and the second grooves (14) extending parallel to each other in a second direction, the second direction being perpendicular to the first direction, a said first groove (13) intersecting a said second groove (14) at a groove node (15), wherein the tank wall (1) comprises a metal sealing plate (22), the metal sealing plate (22) having an upper face and a lower face, the lower face of the metal sealing plate (22) being bonded to the thermally insulating barrier (6) in said groove node (15) by means of an adhesive resin, first and second thermal protection strips (21) being arranged in said first groove (13) and said second groove (14) outside said groove node (15),in which the waterproof membrane (8) comprises at least three corrugated metal plates (16) which are adjacent to the metal sealing plate (22), each corrugated metal plate (16) being rectangular in shape and comprising a first edge (17) extending in the first direction, and a second edge (18) extending in the second direction, in which the first edges of the corrugated metal plates (16) are welded two by two by overlapping at right angles to the first,

2.

3. thermal protection strip and the second edges of the corrugated metal plates (16) are welded two by two by overlapping in line with the second thermal protection strip, in which at least two of said corrugated metal plates (16) comprise a corner zone (19) welded on the upper face of the metal sealing plate (22), the corner zone (19) connecting said first edge (17) and said second edge (18), said at least two corrugated metal plates (16) having the first edge (17) arranged in line with said first thermal protection strip (21) and the second edge (18) arranged in line with said second thermal protection strip (21),, the upper face of the metal sealing plate (22) comprising a covered portion (42) and an uncovered portion (43) complementary to the covered portion (42),the covered portion (42) being located under the at least three corrugated metal plates (16) and the uncovered portion (43) being intended to be in contact with the liquefied gas. A sealed and thermally insulating tank (71) according to claim 1, wherein the sealed membrane (8) comprises three corrugated metal plates (16) which are adjacent to the metal sealing plate (22), wherein two of said corrugated metal plates (16) comprise a corner zone (19) welded to the upper face of the metal sealing plate (22), said two corrugated metal plates (16) having the first edge (17) arranged in line with said first thermal protection strip (21) and the second edge (18) arranged in line with said second thermal protection strip (21), and wherein the first edge (17) of a third of said corrugated metal plates passes through the upper face of the metal sealing plate (22), the covered portion (42) being located under said three corrugated metal plates (16). Sealed and thermally insulating tank (71) according to claim 1, in which the sealed membrane (8) comprises four corrugated metal plates (16) which are adjacent to the metal sealing plate (22), in which each corrugated metal plate (16) comprises a corner zone (19) welded to the upper face of the metal sealing plate (22), each corrugated metal plate (16) having the first edge (17) arranged in line with said first protective strip thermal (21) and the second edge (18) arranged in line with said second thermal protection strip (21), the covered portion (42) being located under the four corrugated metal plates (16).

4. A sealed and thermally insulating tank (71) according to one of claims 1 to 3, in which the tank wall (1) and the supporting structure (2) are crossed by a pipe, the sealed membrane (8) comprising a closing plate (30) located all around the pipe, the closing plate (30) being provided with an orifice (31) which is crossed by the pipe, at least one of said corrugated metal plates (16) having an edge connected in a sealed manner to the closing plate (30).

5. A sealed and thermally insulating tank (71) according to one of claims 1 to 4, wherein the first groove (13) and the second groove (14) each comprise a groove bottom and two opposite edges spaced apart by a groove width, the first and second thermal protection strips (21) resting against the groove bottom and the metal sealing plate (22) being arranged in the groove node (15) at a distance from the edges of the first groove (13) and the edges of the second groove (14).

6. A sealed and thermally insulating tank (71) according to one of claims 1 to 5, wherein the metal sealing plate (22) is rectangular in shape, two first sides of the metal sealing plate (22) extending in the first direction and two second sides (27) of the metal sealing plate (22) extending in the second direction, the first side (26) joining the second side (27) at a corner (28), the corners being chamfered.

7. A sealed and thermally insulating tank (71) according to one of claims 1 to 6, wherein the corner areas (19) of the corrugated metal plates (16) are chamfered.

8. A sealed and thermally insulating tank (71) according to one of claims 1 to 7, wherein the tank wall (1) is a ceiling wall, the sealed and thermally insulating tank (71) comprising the ceiling wall, a bottom wall opposite the ceiling wall in a height direction, and one or more side walls connecting the bottom wall to the ceiling wall.

9. A sealed and thermally insulating tank (71) according to one of claims 1 to 8, in which the thermally insulating barrier (6) is a primary thermally insulating barrier and the sealed membrane (8) is a primary waterproof membrane, the tank wall (1) further comprising a secondary thermally insulating barrier arranged between the primary thermally insulating barrier and the supporting structure (2), and a secondary waterproof membrane arranged between the secondary thermally insulating barrier and the primary thermally insulating barrier.

10. Sealed and thermally insulating tank (71) according to one of claims 1 to 9, in which the thermal protection strips (21) are made of strips of glass or rock wool.

11. A sealed and thermally insulating tank (71) according to one of claims 1 to 10, wherein the lower face of the metal sealing plate (22) is bonded to the thermally insulating barrier (6) in said groove node (15) using an adhesive resin, the adhesive resin being configured to support a load greater than or equal to the weight of the metal sealing plate (22) at room temperature during a manufacturing time of the sealed and thermally insulating tank (71).

12. Vessel (70) for transporting a cold liquid product, the vessel comprising a double hull (72) and a sealed and thermally insulating tank (71) according to one of claims 1 to 11 arranged in the double hull.

13. A transfer system for a cold liquid product, the system comprising a vessel (70) according to claim 12, 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) and a pump for driving a flow of cold liquid product through the insulated pipes from or to the floating or land-based storage facility to or from the sealed and thermally insulating tank (71) of the vessel.

14. A method of mounting a waterproof membrane (8) on a tank wall (1) of a sealed and thermally insulating tank (71) for storing liquefied gas, the sealed and thermally insulating tank (71) being integrated into a supporting structure (2), wherein the mounting method comprises the following steps: - providing a tank wall (1) comprising a thermally insulating barrier (6) fixed to the supporting structure (2), the thermally insulating barrier (6) comprising insulating panels juxtaposed with each other and comprising cover plates (10), the thermal barrier insulating panel (6) comprising first grooves (13) and second grooves (14) made on the cover plates (10) of the insulating panels, the first grooves (13) extending parallel to each other in a first direction and the second grooves (14) extending parallel to each other in a second direction, the second direction being perpendicular to the first direction, a said first groove (13) intersecting a said second groove (14) at a groove node (15), first and second thermal protection strips (21) being arranged respectively in said first groove (13) and said second groove (14), - cutting the first and second thermal protection strips (21) at said groove node (15), - provide a metal sealing plate (22) comprising an upper face and a lower face, - gluing the underside of the metal sealing plate (22) at said groove node (15) to the cover plate (10), - providing four corrugated metal plates (16) intended to form a waterproof membrane (8) of the tank wall (1), each metal plate being rectangular in shape and comprising a first edge (17) and a second edge (18), the first edge (17) joining the second edge (18) at a corner area (19), - arranging and welding the four corrugated metal plates (16) so that each first edge (17) is arranged in line with one of the first grooves (13), each second edge (18) is arranged in line with one of the second grooves (14), the first edges of the corrugated metal plates (16) being welded two by two by overlapping in line with the first thermal protection strip and the second edges of the corrugated metal plates (16) being welded two by two by overlapping in line with the second thermal protection strip, the corner zone (19) of the corrugated metal plates (16) being welded to the upper face of the metal sealing plate (22), the upper face of the metal sealing plate (22) comprising a covered portion (42) and an uncovered portion (43) complementary to the covered portion (42),the covered portion (42) being located under the four corrugated metal plates (16) and the uncovered portion (43) being intended to be in contact with the liquefied gas.

15. A method of mounting a waterproof membrane (8) according to claim 14, wherein before the step of bonding the metal sealing plate (22), the method comprises the step of arranging a template (23) in said groove node (15), the template (23) comprising a border (24) at least partially surrounding a housing (25), the housing (25) having a shape at least partially complementary to the metal sealing plate (22), and wherein the step of bonding the metal sealing plate (22) is carried out by arranging the metal sealing plate (22) in the housing (25) of the template (23), the template (23) preferably being removed after the step of bonding the metal sealing plate (22).

16. A method of mounting a waterproof membrane (8) according to claim 14 or claim 15, wherein before the step of arranging and welding the corrugated metal plates (16), the method comprises the step of marking the metal sealing plate (22) with positioning marks, the positioning marks being configured to indicate the position of the corner areas of the corrugated metal plates (16) to be arranged.

17. A 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 sealed and thermally insulating tank (71) of the ship (70) according to claim 12.

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