Method for manufacturing a sealed tank

Abstract

A method comprising: fastening a spacer block (5) to at least one flat zone (15) of an outer sealed membrane (4), wherein the outer sealed membrane is a primary membrane belonging to a wall of the sealed tank (1) for storing the first liquefied gas, the outer sealed membrane being metallic; the spacer block having an outer end, a flat inner face parallel to the outer end, and lateral ends connecting the outer end to the inner face, the outer end being positioned against the at least one flat zone; and arranging at least one flat zone (17) of a metallic inner sealed membrane (6) against the inner face of the spacer block, such that the inner sealed membrane is spaced apart from the outer sealed membrane by the spacer block.

Description

Manufacturing process for a watertight tank

[0001] The invention relates to the field of sealed tanks. In particular, the invention relates to the field of sealed tanks for the storage and / or transport of a liquefied gas and methods of manufacturing such sealed tanks. Technological background

[0002] In the state of the art, sealed tanks are known for storing liquefied gas. Such a sealed tank comprises, for example, a tank wall having a multi-layer structure which successively comprises a primary sealed membrane intended to be in contact with a product contained in the tank, a primary insulating barrier, a secondary sealed membrane and a secondary insulating barrier.

[0003] The inventors have found that in the case of liquefied gas storage, if the primary sealed membrane is damaged or has an imperfection that allows liquid gas to pass into the inter-membrane space, known tanks would not always allow the tank to be kept in operation safely. Indeed, the elements located under the primary membrane of known tanks are made of materials that deteriorate upon contact with certain liquefied gases.

[0004] Furthermore, in the case of an existing tank, for example in the case of a tank suitable for use in storing liquefied natural gas (LNG), the elements located under the primary membrane will not necessarily be suitable for contact with another liquefied gas, such as ammonia or liquid hydrogen (LH2).

[0005] On the other hand, liquid ammonia, which is a denser liquid and therefore heavier than LNG, for example, the forces transmitted to the primary waterproof membrane would be greater and could therefore cause damage to a primary waterproof membrane.

[0006] On the other hand, liquid hydrogen, which is at around -253°C at atmospheric pressure, generates mechanical, chemical and thermodynamic constraints on the tank which are different from those exerted by LNG.

[0007] There is therefore a real need to design or improve tanks intended to receive liquefied gas, particularly to receive liquefied gas which is colder and / or incompatible with the underlying insulation elements, in particular when the thermal insulation comprises polypropylene or polyurethane foam, or plywood. Indeed, the contact of these elements with certain liquefied gases such as ammonia leads to a significant loss of mechanical strength of these elements.

[0008] One idea behind the invention is to solve at least some of the above-mentioned problems.

[0009] Another idea underlying the invention is to produce a sealed tank capable of receiving a liquefied gas, in particular a gas incompatible with certain thermally insulating materials, for example liquefied ammonia which is at approximately -33°C at atmospheric pressure.

[0010] Another idea behind the invention is to provide a method for adapting a sealed and thermally insulating tank initially used for LNG storage to store another liquefied gas such as ammonia or liquid hydrogen.

[0011] According to one embodiment, the invention is a method described in claim 1.

[0012] According to embodiments, the method is as described in claims 2 to 24.

[0013] According to one embodiment, the method for adapting a sealed tank makes it possible to obtain a sealed tank for storing a liquefied gas, the sealed tank comprising a tank wall intended to be installed in a supporting structure, the tank wall comprising, in a thickness direction of the tank wall: - an external metallic sealed membrane and comprising a first series of parallel corrugations and flat areas;- a spacer block arranged on at least one said flat area of ​​the outer waterproof membrane and fixed to the outer waterproof membrane, the spacer block having an outer end, a flat inner face parallel to the outer end and lateral ends connecting the outer end to the inner face, the outer end being positioned against said at least one flat area, the lateral ends comprising a first lateral end extending parallel to the first series of corrugations and facing a first corrugation of the first series of corrugations, the inner face comprising a first end portion partially overhanging the first corrugation; - and a metallic inner waterproof membrane intended to be in contact with the liquefied gas, in which the inner waterproof membrane is spaced from the outer waterproof membrane by the spacer block and comprises at least one flat portion which is fixed against the inner face of the spacer block.;

[0014] Thanks to these characteristics, the spacer block can be positioned above a corrugation of the external waterproof membrane. As a result, the transmission of hydrostatic pressure forces to the underlying elements is optimal and the support of the internal waterproof membrane is satisfactory.

[0015] According to one embodiment, the method for adapting a sealed tank initially intended for the storage of a first liquefied gas comprises: fixing a spacer block on at least one flat area of ​​an external sealed membrane, in which the external sealed membrane is a primary membrane belonging to a wall of a sealed tank for the storage of the first liquefied gas, the external sealed membrane being metallic and comprising a first series of parallel corrugations;the spacer block having an outer end, a flat inner face parallel to the outer end and lateral ends connecting the outer end to the inner face, the outer end being positioned against said at least one flat area, the lateral ends comprising a first lateral end extending parallel to the first series of corrugations and facing a first corrugation of the first series of corrugations, the inner face comprising a first end portion partially overhanging the first corrugation; and fixing at least one flat area of ​​an internal metallic waterproof membrane against the inner face of the spacer block, so that the internal waterproof membrane is spaced from the external waterproof membrane by the spacer block.;

[0016] The use of this process makes it possible in particular to anchor the spacer block directly on a primary membrane belonging to a sealed and thermally insulating tank wall for LNG storage, without the need to install thermal protections between the flat area of ​​the external sealed membrane and the thermally insulating barrier.

[0017] According to embodiments, such a tank obtained by the method or such a method may comprise one or more of the following characteristics.

[0018] According to one embodiment, the first lateral end develops between the external end and the internal face of the spacer block towards the first corrugation.

[0019] According to one embodiment, the flat area of ​​the external waterproof membrane is located between two undulations of the first series of undulations.

[0020] According to one embodiment, the first lateral end has a concave shape so as to overhang the first corrugation.

[0021] Thanks to these characteristics, the first lateral end remotely matches the shape of the first corrugation in order to obtain good support of the internal surface of the spacer block without interacting with the corrugation of the external waterproof membrane, thus making it possible to obtain good support of the internal waterproof membrane.

[0022] According to one embodiment, the first lateral end is not in contact with the first corrugation. Thus, the first corrugation is free to open and close without its movement being hindered by contact of the spacer block against the first corrugation. According to one embodiment, the lateral ends are not in contact with the corrugations of the external waterproof membrane.

[0023] According to one embodiment, the spacer block is not in contact with the corrugations of the external waterproof membrane.

[0024] According to one embodiment, the spacer block has a thickness less than a height of the first series of undulations in the thickness direction of the tank wall.

[0025] According to one embodiment, the spacer block has a thickness greater than a height of the first corrugation series in the thickness direction of the tank wall.

[0026] According to one embodiment, the thickness of the spacer block is between 20 and 150 mm.

[0027] According to one embodiment, the external waterproof membrane comprises a second series of undulations perpendicular to the first series of undulations.

[0028] According to one embodiment, the lateral ends of the spacer block comprise a second lateral end extending parallel to the second series of undulations and facing respectively towards a first undulation of the second series of undulations, the internal face comprising a second end portion partially overhanging the first undulation of the second series of undulations.

[0029] According to one embodiment, the second lateral end develops between the external end and the internal face of the spacer block towards the first corrugation of the second series of corrugations.

[0030] According to one embodiment, the flat area is defined between two undulations of the first series of undulations and two undulations of the second series of undulations.

[0031] According to one embodiment, the corrugations of the external waterproof membrane protrude relative to the flat areas towards the interior of the tank.

[0032] According to one embodiment, a height of the first series of corrugations is less than a height of the second series of corrugations in the thickness direction of the tank wall. According to one embodiment, the spacer block has a thickness between the height of the second series of corrugations and the height of the first series of corrugations.

[0033] According to one embodiment, the spacer block comprises support ribs located under the internal face between the lateral ends and hollow cells located between the support ribs.

[0034] Thus, the spacer block is reinforced by the support ribs. In addition, the hollow cells allow the internal space of the spacer block to be inerted, allowing the passage of gas molecules between the hollow cells located inside the spacer block and the inter-membrane space located between the internal waterproof membrane and the external waterproof membrane.

[0035] According to one embodiment, the support ribs are parallel. According to one embodiment, the support ribs are connected to each other.

[0036] According to one embodiment, the hollow cells have, in sectional view, a rectangular or triangular shape.

[0037] According to one embodiment, the outer end of the spacer block is formed by edges of the side ends and / or end edges of the support ribs, the hollow cells being open at the outer end of the spacer block.

[0038] Thus, the hollow cells make it possible to inert the internal space of the spacer block, allowing the passage of gas molecules between the hollow cells located inside the spacer block and the inter-membrane space located between the internal sealed membrane and the external sealed membrane.

[0039] According to one embodiment, one lateral end of the lateral ends is formed by lateral edges of the support ribs. According to one embodiment, the first lateral end is formed by lateral edges of the support ribs. According to one embodiment, the lateral ends are formed by end edges of the support ribs.

[0040] According to one embodiment, the outer end and the lateral ends are formed by end edges of the support ribs.

[0041] According to one embodiment, the external end of the spacer block is formed by a flat external face parallel to the internal face.

[0042] Thanks to these characteristics, the carrying of the internal waterproof membrane by the spacer block is improved.

[0043] According to one embodiment, at least one lateral end of the lateral ends comprises a side wall traversed by a through passage. According to one embodiment, the first lateral end comprises a side wall traversed by a through passage.

[0044] According to one embodiment, at least one lateral end of the lateral ends comprises a plurality of through passages.

[0045] According to one embodiment, a lateral end comprises a plurality of support elements spaced from each other by through passages, the support elements preferably being spacers connecting the external end and the internal face of the spacer block.

[0046] According to one embodiment, the tank obtained by the method further comprises a fixing piece fixed to the flat area of ​​the external waterproof membrane and projecting towards the internal waterproof membrane, the spacer block being fixed to the fixing piece. According to one embodiment, the fixing piece is chosen from a metal cylinder or a metal strip. According to a preferred embodiment, the fixing piece is a metal rod, for example a metal stud.

[0047] According to one embodiment, the fixing piece is fixed to the outer waterproof membrane by welding on an inner face of the flat area of ​​the outer waterproof membrane. According to one embodiment, the fixing piece is fixed via the capacitor discharge welding method.

[0048] Thus, the fixing part such as a fixing rod can be fixed directly to the external membrane, without passing through said external waterproof membrane. This embodiment is particularly advantageous when it comes to adapting a sealed and thermally insulating tank initially intended for the storage of LNG, in order to store liquid ammonia. Indeed, the capacitor discharge welding process also makes it possible not to degrade the underlying insulation by heat, without the need to add additional thermal protection.

[0049] According to one embodiment, the spacer block comprises a temporary through-hole intended for the passage and fixing of the fixing rod. According to one embodiment, the spacer block comprises a metal cover closing the temporary fixing hole.

[0050] According to one embodiment, the spacer block comprises a retaining surface cooperating with a nut or clip mounted on the fixing part.

[0051] According to one embodiment, the spacer block is made of a material compatible with the liquefied gas which is intended to be contained in the tank.

[0052] According to one embodiment, the spacer block comprises aluminum, a thermoplastic or thermosetting material, preferably reinforced with glass fibers.

[0053] In one embodiment, the spacer comprises an aluminum alloy, for example aluminum alloy 6082. In one embodiment, the spacer block comprises more than 50% aluminum by mass of the spacer. In one embodiment, the spacer block consists of aluminum.

[0054] Thanks to these characteristics, the spacer block is compatible with ammonia, that is to say that the spacer block is not damaged by contact with liquid or gaseous ammonia, that is to say that the physical properties of the spacer block mainly allowing the carrying of the internal membrane are not altered by contact with ammonia. Consequently, thanks to these characteristics, if the internal sealed membrane is damaged and allows liquid or gaseous ammonia to pass into the inter-membrane space, said tank manufactured by the method comprising the damaged internal membrane will be able to continue to operate, without having to empty said tank.

[0055] The spacer block is considered compatible if it can be in contact with liquid or gaseous ammonia for at least 8 days without its carrying capacity being altered.

[0056] According to one embodiment, the spacer block comprises aluminum obtained by extrusion.

[0057] According to one embodiment, the thermoplastic material is chosen from: high density polyethylene, polypropylene and impact polystyrene.

[0058] According to one embodiment, the spacer block made of thermoplastic material comprises fibers, for example long fibers.

[0059] According to one embodiment, the composite spacer block is obtained by thermo-stamping or by injection.

[0060] According to one embodiment, the spacer block does not comprise thermally insulating materials.

[0061] According to one embodiment, the at least one flat zone comprises a first flat zone, the spacer block has a thickness greater than a height of the first series of corrugations in the thickness direction of the tank wall and the external end of the spacer block is arranged on at least a second flat zone of the external waterproof membrane, the spacer block extending over at least one other corrugation of the first series of corrugations located between said first flat zone and said second flat zone.

[0062] According to one embodiment, the spacer block has a thickness greater than a height of the second series of corrugations in the thickness direction of the tank wall and the outer end of the spacer block is arranged on at least one other flat area of ​​the outer waterproof membrane, the spacer block extending over another corrugation of the second series of corrugations located between said first flat area and said other flat area.

[0063] Preferably in this case, the height of the first series of corrugations is less than the height of the second series of corrugations in the thickness direction of the tank wall.

[0064] According to one embodiment, the outer end of the spacer block is arranged on at least one second flat area of ​​the outer waterproof membrane, the spacer block extending over at least one other corrugation of the first series of corrugations located between said first flat area and said second flat area and the outer end of the spacer block is further arranged on at least one other flat area of ​​the outer waterproof membrane, the spacer block extending over another corrugation of the second series of corrugations located between said first flat area and said other flat area.

[0065] According to one embodiment, the external end of the spacer block is arranged on n flat areas of the external waterproof membrane, n being a number chosen between 2 and 20, and preferably chosen between 2 and 9.

[0066] According to one embodiment, the spacer block extends over a number of between 2 and 9 undulations of the first series of undulations.

[0067] According to one embodiment, the spacer block extends over a number of between 2 and 9 undulations of the second series of undulations.

[0068] In one embodiment, the spacer block extends over two corrugations of the first series of corrugations and over two corrugations of the second series of corrugations. In one embodiment, the spacer block extends over two corrugations of the first series of corrugations and over three corrugations of the second series of corrugations. In one embodiment, the spacer block extends over three corrugations of the first series of corrugations and over two corrugations of the second series of corrugations. In one embodiment, the spacer block extends over three corrugations of the first series of corrugations and over three corrugations of the second series of corrugations.

[0069] According to one embodiment, the outer end of the spacer block comprises a portion having a shape complementary to a corrugation of the first series of corrugations and / or a shape complementary to a corrugation of the second series of corrugations so as to pass over and at a distance from the corrugation of the first series of corrugations and / or over the second series of corrugations. According to one embodiment, the complementary shape is formed by embossing the outer end of the spacer block.

[0070] According to one embodiment, the lateral ends comprise a third lateral end located opposite the first lateral end extending parallel to the first series of undulations, the internal face comprising a third end portion partially overhanging said second undulation of the first series of undulations.

[0071] According to one embodiment, the third lateral end develops between the external end and the internal face of the spacer block towards the second corrugation of the first series of corrugations.

[0072] According to one embodiment, the inner face has a larger dimension than the outer end in a direction transverse to the first series of undulations.

[0073] According to one embodiment, the lateral ends comprise a fourth lateral end located opposite the second lateral end, the fourth lateral end developing between the external end and the internal face of the spacer block towards a second corrugation of the second series of corrugations, so that the internal face comprises a fourth end portion partially overhanging said second corrugation.

[0074] According to one embodiment, the internal waterproof membrane comprises a first series of undulations parallel to the first series of undulations of the external waterproof membrane and flat areas.

[0075] According to one embodiment, at least one corrugation of the first series of corrugations of the internal waterproof membrane is opposite the first corrugation of the first series of corrugations of the external waterproof membrane in the thickness direction of the tank wall.

[0076] Thus, the process makes it possible in particular to obtain a tank in which the thickness of the spacer block is less than the height of the first undulations of the external membrane.

[0077] According to one embodiment, at least one corrugation of the first series of corrugations of the internal waterproof membrane is offset from the first corrugation of the first series of corrugations of the external waterproof membrane in the thickness direction of the tank wall.

[0078] According to one embodiment, the two feet of the corrugation of the first series of corrugations are positioned against the internal face of the spacer block.

[0079] According to one embodiment, the pitch of the corrugations of the first series of corrugations of the external waterproof membrane is identical to the pitch of the corrugations of the first series of corrugations of the internal waterproof membrane.

[0080] According to one embodiment, the pitch of the corrugations of the first series of corrugations of the external waterproof membrane is different from the pitch of the corrugations of the first series of corrugations of the internal waterproof membrane.

[0081] According to one embodiment, the first series of ripples is a series of small ripples. In this case, the second series of ripples may be a series of large ripples.

[0082] According to another embodiment, the first series of ripples is a series of large ripples. In this case, the second series of ripples may be a series of small ripples.

[0083] According to yet another embodiment, the first series of undulations and the second series of undulations have the same height.

[0084] According to one embodiment, the corrugations of the internal waterproof membrane are protruding relative to the flat areas towards the interior of the tank.

[0085] According to one embodiment, the internal sealed membrane of the sealed tank is intended to be in contact with a second liquefied gas chosen from: ammonia, butane, propane or ethane, and preferably ammonia.

[0086] According to one embodiment, the first liquefied gas and the second liquefied gas are identical. According to one embodiment, the first liquefied gas and the second liquefied gas are different. According to one embodiment, the first liquefied gas is LNG.

[0087] According to one embodiment, an internal space of the tank delimited by the internal sealed membrane contains a liquefied gas chosen from: ammonia, butane, propane or ethane, and preferably with ammonia. Thus, the internal sealed membrane is in contact with the second liquefied gas.

[0088] According to one embodiment, the tank wall comprises a metal insert which is fixed on the internal face of the spacer block and the internal waterproof membrane is welded to the metal insert. Further details on the geometry or fixing of the metal insert are illustrated in particular in document EP0064886A1, mainly with figures 7 to 10 in which the insulating barrier should be replaced by the spacer block.

[0089] According to one embodiment, the internal waterproof membrane and the external waterproof membrane are made of stainless steel.

[0090] According to one embodiment, the sealed tank is thermally insulating and the tank wall comprises at least one thermally insulating barrier arranged between the external sealed membrane and the supporting structure. For example, the thermally insulating barrier may comprise insulating elements made of various materials, in particular materials incompatible with the second liquefied gas, for example incompatible with ammonia such as polyurethane foam or glass wool.

[0091] Thus, when the external waterproof membrane is fixed against the thermally insulating barrier, the spacer block allows in particular to transmit the hydrostatic pressure forces to said thermally insulating barrier. In addition, the spacer block allows to better distribute the loads on the underlying thermally insulating barrier. Indeed, when the internal waterproof membrane undergoes a concentrated stress on a smaller surface than the surface of the spacer block, the insulating block will allow to distribute the stress on a larger surface of the underlying thermally insulating barrier.

[0092] Furthermore, thanks to these characteristics, it is possible to inertize the inter-membrane space located between the internal waterproof membrane and the external waterproof membrane. Consequently, in the event of a gas leak from the internal waterproof membrane to the inter-membrane space, it will be possible to evacuate the unwanted gas from said inter-membrane space without damaging the underlying thermally insulating barrier incompatible with the second liquefied gas.

[0093] Furthermore, replacing a tank or modifying structural elements already present in a tank represents very significant material and financial costs.

[0094] Thus, the aforementioned method is advantageous in that it makes it possible in particular to extend the lifespan of a tank which has already been used for the storage of a first liquefied gas.

[0095] According to one embodiment, the tank wall comprises an additional waterproof membrane arranged between the external waterproof membrane and the supporting structure. According to one embodiment, a primary thermally insulating barrier is arranged between the additional waterproof membrane and the external waterproof membrane and a secondary thermally insulating barrier is arranged between the additional waterproof membrane and the supporting structure. According to one embodiment, the primary thermally insulating barrier and / or the secondary thermally insulating barrier comprises polyurethane foam or glass wool.

[0096] According to one embodiment, the tank wall comprises a plurality of spacer blocks which are each located on a respective flat area of ​​the plurality of flat areas of the external waterproof membrane.

[0097] According to one embodiment, a spacer block is located on each flat area of ​​the external waterproof membrane.

[0098] According to one embodiment, each flat area of ​​the external waterproof membrane is covered by an external end of a spacer block which is arranged thereon.

[0099] An outer end of the same spacer block may rest on several flat areas and / or an outer end of a spacer block may rest on a single flat area.

[0100] According to one embodiment, the internal space of the tank has a storage capacity of more than 70,000 m 3 .

[0101] According to one embodiment, the aforementioned tank wall is a bottom wall of the tank when the tank is in a position of use.

[0102] According to one embodiment, the aforementioned tank wall is a side wall of the tank when the tank is in a position of use.

[0103] According to one embodiment, the tank comprises a plurality of aforementioned walls.

[0104] According to one embodiment, the invention also provides a liquefied gas storage facility comprising a supporting structure and a sealed tank manufactured by the aforementioned method, the sealed tank being positioned and fixed against the supporting structure.

[0105] According to one embodiment of the method, the first liquefied gas is LNG.

[0106] According to one embodiment of the method, the internal waterproof membrane is intended to be in contact with ammonia, butane, propane or ethane, preferably with ammonia.

[0107] According to one embodiment of the method, the sealed and thermally insulating tank wall for storing the first liquefied gas has a multi-layer structure which successively comprises, from the outside of the tank, a secondary insulating barrier, a secondary sealed membrane, a primary insulating barrier and a primary sealed membrane.

[0108] According to one embodiment, the spacer block is fixed to the flat area of ​​an external waterproof membrane via a fixing piece welded to an internal face of the flat area of ​​the external waterproof membrane and projecting from the external waterproof membrane, the spacer block being fixed to the fixing piece, the welding being able to be carried out via the capacitor discharge welding method. According to one embodiment, the fixing piece is chosen from a metal cylinder or a metal strip. According to a preferred embodiment, the fixing piece is a metal rod, for example a metal stud.

[0109] According to another embodiment, the sealed tank obtained by the method comprises a sealed and thermally insulating wall comprising, according to the thickness direction of the wall: a thermally insulating barrier comprising an internal metal anchoring strip, a sealed membrane located against the thermally insulating barrier, the sealed membrane comprising parallel corrugations spaced apart by flat areas, the sealed membrane comprising a first metal sheet and a second metal sheet, the second metal sheet being adjacent to the first metal sheet at a junction area, the sealed membrane being fixed to the internal metal anchoring strip at the junction area, the wall further comprising a primary coupler comprising an external metal plate welded to the junction area,a stud projecting from an inner face of the metal plate in the thickness direction of the wall and a backing plate mounted on the stud, wherein the wall further comprises a primary thermally insulating barrier positioned against the waterproof membrane, the primary thermally insulating barrier comprising primary thermally insulating panels retained against the waterproof membrane by the backing plate, the wall comprising a primary waterproof membrane located against the primary thermally insulating barrier.,

[0110] Thanks to these characteristics, it is possible to fix primary thermally insulating panels against the waterproof membrane at a junction area. In fact, the external metal plate allows on the one hand to obtain a flat surface at the junction area and on the other hand to obtain a sufficient surface to allow the welding of the stud and to install the support plate in order to allow the fixing of the primary thermally insulating panels.

[0111] The primary waterproof membrane, also called the internal waterproof membrane, refers to the same structural element, i.e. the waterproof membrane which is intended to be in contact with the liquefied gas contained in the tank.

[0112] The located waterproof membrane and the thermally insulating barrier formed, before the implementation of the process, a tank wall initially used for the storage of a first liquefied gas such as LNG. The addition by the process: of the primary coupler, the primary thermally insulating barrier and the primary waterproof membrane makes it possible to obtain the wall and therefore tank adapted by said process.

[0113] According to embodiments, the wall may comprise one or more of the following features.

[0114] According to one embodiment, the primary thermally insulating panels comprise a layer of polymer foam sandwiched between an outer rigid plate and an inner rigid plate.

[0115] According to one embodiment, the external rigid plate is made of plywood.

[0116] According to one embodiment, the internal rigid plate is made of plywood.

[0117] According to one embodiment, the polymer foam layer is a block of polyurethane foam, preferably reinforced with fibers.

[0118] According to one embodiment, at least one said primary thermally insulating panel has, in an area adjacent to the primary coupler, a well formed through the polymer foam layer and the internal rigid plate to reveal a bearing portion of the external rigid plate, and in which the bearing plate is engaged with the bearing portion of the external rigid plate.

[0119] According to one embodiment, at least two primary thermally insulating panels having a general rectangular parallelepiped shape have a respective corner adjacent to the primary coupler, each of said at least two primary thermally insulating panels having said well in a corner area adjacent to the primary coupler and in which the support plate is engaged with the support portion of the external rigid plate of each of said at least two primary thermally insulating panels.

[0120] According to one embodiment, the wall further comprises a plug filling a space formed between the primary thermally insulating panels at the primary coupler, the plug comprising an internal cover plate intended to form a flat surface with the internal rigid plates of the primary thermally insulating panels.

[0121] According to one embodiment, the plug fills the well formed through the polymer foam layer and the internal rigid plate.

[0122] According to one embodiment, the plug comprises a main body made of thermally insulating material, for example polyurethane foam, preferably reinforced with fibers.

[0123] According to one embodiment, the main body of the plug has an outer end in contact with the support plate and an inner end in contact with the inner cover plate.

[0124] According to one embodiment, the main body of the plug has a thickness similar, in the direction of thickness of the wall, to the thickness of the polymer foam layer.

[0125] According to one embodiment, the main body of the stopper has a general parallelepiped shape, for example the shape of a rectangular parallelepiped, for example a cubic shape, with possibly rounded edges.

[0126] According to one embodiment, the primary thermally insulating panels each comprise a counterbore at an edge of the internal rigid plate adjacent to the primary coupler. According to one embodiment, the internal cover plate bears on the counterbores of the primary thermally insulating panels in order to form the flat surface with the internal rigid plates of the primary thermally insulating panels.

[0127] Thus, the support of the primary waterproof membrane is continuous, which gives greater resistance and longevity to the wall when it is part of a tank intended to store and / or transport liquefied gas manufactured by the process. Indeed, the walls of a tank are subjected to compressive forces due to the loading of the tank, to thermal stresses during cold setting and to forces due to the dynamic shocks of the fluid contained in the tank.

[0128] According to one embodiment, the internal cover plate is fixed against the counterbores, preferably by a screw, a staple or glue.

[0129] According to one embodiment, the primary thermally insulating panels have a rectangular parallelepiped shape.

[0130] According to one embodiment, the primary thermally insulating panels each comprise a counterbore at a corner of the internal rigid plate, adjacent to the primary coupler.

[0131] According to one embodiment, the internal cover plate has a thickness less than the thickness of the internal rigid plate.

[0132] According to one embodiment, the internal cover plate has a generally rectangular shape, for example the shape of a square, possibly with rounded edges.

[0133] According to one embodiment, the internal cover plate comprises an internal metal sheet, the primary waterproof membrane being welded to the internal metal sheet.

[0134] According to one embodiment, the internal metal sheet has a generally rectangular shape, for example the shape of a square, possibly with rounded edges.

[0135] According to one embodiment, the support plate comprises an orifice crossed by the stud.

[0136] According to one embodiment, the support plate is metallic.

[0137] According to one embodiment, the support plate has a smaller surface area than the surface area of ​​the internal cover plate of the plug.

[0138] In one embodiment, a fastener secures the backing plate by exerting a compressive force toward the outer metal plate. In one embodiment, the fastener is a nut mounted on the stud, over the backing plate.

[0139] Thus, the support plate presses and holds the primary thermally insulating panels firmly against the waterproof membrane.

[0140] According to one embodiment, at least one of the primary thermally insulating panels is located on two adjacent flat areas separated by a corrugation and passes over the corrugation, said primary thermally insulating panel comprising an external groove providing space for the corrugation.

[0141] According to one embodiment, the external groove has a cross section matching a cross section of the corrugation.

[0142] Thus, the wall provides better thermal insulation by limiting thermal convection phenomena between the corrugation and the external groove which follows the shape of the corrugation.

[0143] According to one embodiment, the external groove extends through the external rigid plate and through a thickness portion of the polymer foam layer.

[0144] According to one embodiment, the primary thermally insulating panels adjacent to the primary coupler are each located on two adjacent flat areas separated by a corrugation and pass over the corrugation, said primary thermally insulating panels each comprising an external groove matching the shape of the corrugation.

[0145] According to one embodiment, the primary waterproof membrane comprises parallel corrugations spaced by flat areas. According to one embodiment, the primary waterproof membrane comprises a first primary metal sheet and a second primary metal sheet, the second primary metal sheet being adjacent to the first primary metal sheet at a primary junction area, the junction area and the primary junction area being located opposite each other, the primary waterproof membrane being welded to the inner metal sheet at the primary junction area.

[0146] Thanks to these characteristics, it is possible both to fix primary thermally insulating panels against the waterproof membrane at a junction zone and to fix the primary waterproof membrane at a primary junction zone located opposite the junction zone.

[0147] According to one embodiment, the second primary metal sheet is welded to the first primary metal sheet by overlapping an edge of the first primary metal sheet with an edge of the second primary metal sheet.

[0148] According to one embodiment, the primary waterproof membrane comprises a third primary metal sheet adjacent to the first primary metal sheet and the second primary metal sheet at the primary junction area.

[0149] According to one embodiment, the primary waterproof membrane comprises a fourth primary metal sheet adjacent to the first primary metal sheet, the second primary metal sheet and the third primary metal sheet at the primary junction area.

[0150] According to one embodiment, the primary joining area is formed by joining a first corner area of ​​the first primary metal sheet, a second corner area of ​​the second primary metal sheet, a third corner area of ​​the third primary metal sheet and a fourth corner area of ​​the fourth primary metal sheet.

[0151] According to one embodiment, the parallel corrugations of the primary waterproof membrane are first parallel corrugations, the primary waterproof membrane further comprising second corrugations spaced apart and parallel to each other, the second corrugations being perpendicular to the first parallel corrugations, the flat areas being located between two adjacent first corrugations and two adjacent second corrugations.

[0152] According to one embodiment, the first corrugations of the primary waterproof membrane are intended to be directed towards the inside of the tank. According to one embodiment, the second corrugations of the primary waterproof membrane are intended to be directed towards the inside of the tank.

[0153] According to one embodiment, the second metal sheet is welded to the first metal sheet by covering an edge of the first metal sheet with an edge of the second metal sheet.

[0154] According to one embodiment, the waterproof membrane comprises a third metal sheet adjacent to the first metal sheet and the second metal sheet at the junction zone.

[0155] According to one embodiment, the waterproof membrane comprises a fourth metal sheet adjacent to the first metal sheet, the second metal sheet and the third metal sheet at the junction zone.

[0156] According to one embodiment, the joining area is formed by joining a first corner area of ​​the first metal sheet, a second corner area of ​​the second metal sheet and the third metal sheet.

[0157] According to one embodiment, the joining area is formed by joining a first corner area of ​​the first metal sheet, a second corner area of ​​the second metal sheet, a third corner area of ​​the third metal sheet and a fourth corner area of ​​the fourth metal sheet.

[0158] According to one embodiment, the parallel corrugations of the waterproof membrane are first parallel corrugations, the waterproof membrane further comprising second corrugations spaced apart and parallel to each other, the second corrugations being perpendicular to the first parallel corrugations, the flat areas being located between two adjacent first corrugations and two adjacent second corrugations.

[0159] According to one embodiment, the first corrugations of the waterproof membrane are intended to be directed towards the inside of the tank. According to one embodiment, the second corrugations of the waterproof membrane are intended to be directed towards the inside of the tank.

[0160] According to one embodiment, the first metal sheet is located opposite the first primary metal sheet.

[0161] According to one embodiment, the second metal sheet is located opposite the second primary metal sheet.

[0162] According to one embodiment, the third metal sheet is located opposite the third primary metal sheet.

[0163] According to one embodiment, the fourth metal sheet is located opposite the fourth primary metal sheet.

[0164] According to one embodiment, the first metal sheet has dimensions similar to the first primary metal sheet.

[0165] According to one embodiment, the second metal sheet has dimensions similar to the second primary metal sheet.

[0166] According to one embodiment, the third metal sheet has dimensions similar to the third primary metal sheet.

[0167] According to one embodiment, the fourth metal sheet has dimensions similar to the fourth primary metal sheet.

[0168] According to one embodiment, the first, second, third and / or fourth metal sheets have similar dimensions.

[0169] According to one embodiment, the first, second, third and / or fourth metal sheets have similar dimensions with the first, second, third and / or fourth primary metal sheets.

[0170] According to one embodiment, the outer metal plate covers a portion of the first corner area of ​​the first metal sheet, a portion of the second corner area of ​​the second metal sheet, a portion of the third corner area of ​​the third metal sheet and a portion of the fourth corner area of ​​the fourth metal sheet.

[0171] According to one embodiment, the external metal plate has a generally rectangular shape, for example the shape of a square, possibly with rounded edges.

[0172] According to one embodiment, the external metal plate has a thickness less, in the thickness direction of the wall, than the thickness of the external rigid plate.

[0173] According to one embodiment, the external metal plate is located at a distance from the corrugations of the waterproof membrane.

[0174] According to one embodiment, the junction zone is located at a distance from the undulations of the waterproof membrane.

[0175] According to one embodiment, the stud has a thread.

[0176] According to one embodiment, the stud is metallic.

[0177] According to one embodiment, the primary thermally insulating panels are spaced apart from each other by inter-panel spaces. According to one embodiment, the inter-panel spaces are filled by thermally insulating joints, for example made from glass wool. According to one embodiment, the thermally insulating joints have the shape of a flat rectangular parallelepiped with dimensions adapted to fill the inter-panel spaces.

[0178] According to one embodiment, the primary thermally insulating barrier comprises internal thermal protection strips located between the primary thermally insulating panels and the primary waterproof membrane in order to protect the primary thermally insulating panels from a significant increase in temperature during installation of the primary waterproof membrane, by welding primary metal sheet.

[0179] According to one embodiment, the primary thermally insulating barrier comprises four primary thermally insulating panels.

[0180] According to one embodiment, a first primary thermally insulating panel is held against the first metal sheet of the waterproof membrane by the support plate, a second primary thermally insulating panel is held against the second metal sheet of the waterproof membrane by the support plate, a third primary thermally insulating panel is held against the third metal sheet of the waterproof membrane by the support plate, and a fourth primary thermally insulating panel is held against the third metal sheet of the waterproof membrane by the support plate.

[0181] According to one embodiment, the four primary thermally insulating panels are each held at a corner by the support plate.

[0182] According to one embodiment, the wall comprises a plurality of aforementioned primary couplers.

[0183] According to one embodiment, the plurality of aforementioned primary couplers are located at the corners of the primary thermally insulating panels.

[0184] According to one embodiment, the thermally insulating barrier is an intermediate thermally insulating barrier, the waterproof membrane is an intermediate waterproof membrane, the wall further comprising a secondary waterproof membrane intended to be arranged between the intermediate waterproof membrane and the supporting structure and a secondary thermally insulating barrier intended to be arranged between the secondary waterproof membrane and the supporting structure.

[0185] According to one embodiment, the primary waterproof membrane is intended to be in contact with the liquefied gas.

[0186] According to one embodiment, the liquefied gas is liquid hydrogen.

[0187] According to one embodiment, the method comprises:- providing a waterproof and thermally insulating wall comprising, along the thickness direction of the wall: a thermally insulating barrier comprising an internal metal anchoring strip, a waterproof membrane located against the thermally insulating barrier, the waterproof membrane comprising parallel corrugations spaced apart by flat areas, the waterproof membrane comprising a first metal sheet and a second metal sheet, the second metal sheet being adjacent to the first metal sheet at a junction area, the waterproof membrane being fixed to the internal metal anchoring strip at the junction area,- fixing a primary coupler comprising an external metal plate,a stud and a backing plate by welding the outer metal plate to the junction area and welding the stud so that the stud projects from an inner face of the metal plate in the wall thickness direction,- adding a primary thermally insulating barrier against the waterproof membrane, the primary thermally insulating barrier comprising primary thermally insulating panels,- mounting and fixing the backing plate on the stud to retain the primary thermally insulating panels against the waterproof membrane,- adding and fixing a primary waterproof membrane against the primary thermally insulating barrier.,

[0188] According to one embodiment, the method comprises, before the step of adding and fixing the primary waterproof membrane against the primary thermally insulating barrier: - inserting thermally insulating joints in the spaces located between the adjacent primary thermally insulating panels.

[0189] According to one embodiment, the method comprises, before the step of adding and fixing the primary waterproof membrane against the primary thermally insulating barrier: - inserting a plug to fill a space formed between the primary thermally insulating panels at the primary coupler.

[0190] According to one embodiment, the method comprises, after the step of inserting the plug and before the step of adding and fixing the primary waterproof membrane against the primary thermally insulating barrier: - adding and fixing internal thermal protection strips on the adjacent primary thermally insulating panels.

[0191] According to one embodiment of the method, the primary waterproof membrane is welded onto the cap.

[0192] According to one embodiment, the invention also provides a sealed and thermally insulating tank intended to be fixed to a supporting structure, the tank comprising at least one aforementioned wall.

[0193] According to one embodiment, the tank comprises a plurality of walls including a bottom wall, a side wall and a ceiling wall, wherein the bottom wall and the side wall are a wall according to the aforementioned wall.

[0194] Such a tank manufactured by the above-mentioned process may be part of a land-based storage facility or installed in a floating, coastal or deep-water structure, including a liquefied gas transport vessel, 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.

[0195] According to one embodiment, the supporting structure rests on the ground, on a seabed or is part of a ship.

[0196] According to one embodiment, a land-based installation comprises a supporting structure and a tank manufactured by the aforementioned method arranged in the supporting structure.

[0197] According to one embodiment, a ship for transporting liquefied gas comprises a double hull and a tank manufactured by the aforementioned method arranged in the double hull.

[0198] According to one embodiment, the invention also provides a transfer system for a liquefied gas, the system comprising the aforementioned vessel and insulated pipes arranged so as to connect the tank manufactured by the process of the vessel to a floating or land-based storage installation.

[0199] According to one embodiment, the transfer system also comprises a pump for driving a flow of liquefied gas through the insulated pipes from or to the floating or land-based storage facility to or from the vessel tank.

[0200] According to one embodiment, the invention also provides a method of loading or unloading such a vessel, in which a liquefied gas is conveyed through insulated pipes from or to a floating or land-based storage facility to or from the vessel's tank. Brief description of the figures

[0201] The invention will be better understood, and other objects, details, characteristics and advantages thereof will appear more clearly during the following description of several particular embodiments of the invention, given solely for illustrative and non-limiting purposes, with reference to the accompanying drawings.

[0202] It represents a partial schematic sectional view of a wall of a sealed tank.

[0203] This is an enlarged, sectional view of zone I of the, representing a tank wall according to a first embodiment.

[0204] The figure represents a bottom view of a spacer block according to the first embodiment.

[0205] It represents a partial view, in exploded perspective, of a tank wall according to the first embodiment.

[0206] The figure represents a partial view, in section, showing a tank wall according to a second embodiment.

[0207] It represents a sectional view of a tank wall according to a third embodiment.

[0208] It represents a top view of a tank wall according to a fourth embodiment.

[0209] La represents a partial view, in section, of a corner zone of a tank comprising a spacer block according to a fifth embodiment.

[0210] It represents a partial view, in perspective, of a wall according to a sixth embodiment.

[0211] It represents a partial view, from above, of a waterproof membrane, according to the sixth embodiment.

[0212] It represents a partial view, from above, of a waterproof membrane, according to a seventh embodiment.

[0213] It represents a partial view, in exploded perspective, of a wall according to the sixth embodiment, of which the external metal plate is highlighted.

[0214] It represents a partial view, in exploded perspective, of a wall according to the sixth embodiment, of which the stud is highlighted.

[0215] It represents a partial view, in exploded perspective, of a wall according to the sixth embodiment, of which the primary thermally insulating panels are highlighted.

[0216] It represents a partial view, in exploded perspective, of a wall according to the sixth embodiment, of which the support plate is highlighted.

[0217] It represents a partial view, in exploded perspective, of a wall according to the sixth embodiment, of which the fixing element is highlighted.

[0218] It represents a partial view, in exploded perspective, of a wall according to the sixth embodiment, the thermally insulating joints of which are highlighted.

[0219] It represents a partial view, in exploded perspective, of a wall according to the sixth embodiment, of which the cap is highlighted.

[0220] It represents a partial view, in exploded perspective, of a wall according to the sixth embodiment, of which the internal thermal protection strips are highlighted.

[0221] It represents a partial view, in exploded perspective, of a wall according to the sixth embodiment, of which the primary metal sheets of the primary waterproof membrane are highlighted.

[0222] The figure represents a perspective view of a primary thermally insulating panel, according to the sixth embodiment.

[0223] The represents a perspective view of a primary metal sheet of primary waterproof membrane, according to the sixth embodiment.

[0224] It represents a partial view, in perspective, of a wall according to the sixth embodiment.

[0225] It represents a schematic cutaway representation of a ship's tank and a terminal for loading and unloading this tank.

[0226] By convention, the terms "external" and "internal" are used to define the relative position of one element to another, with reference to the inside and outside of the tank.

[0227] In connection therewith, a sealed tank wall 1 adapted by the method is generally described below, according to embodiments of the method. Such a wall structure may be used to make substantially all the walls of a polyhedral tank. In this regard, the terms 'on', 'overhanging', 'above', 'upper' and 'high' generally refer to a position located towards the inside of the tank and therefore do not necessarily coincide with the notion of high in the Earth's gravitational field. Similarly, the terms 'under', 'below', 'lower' and 'low' generally refer to a position located towards the outside of the tank and therefore do not necessarily coincide with the notion of low in the Earth's gravitational field.

[0228] The wall 1 obtained by the method has a multi-layer structure comprising, along the thickness direction E of the wall 1, from the outside to the inside of the tank: a supporting structure 3, an auxiliary barrier 2, an external sealed membrane 4, a plurality of spacer blocks 5 and an internal sealed membrane 6 intended to be in contact with the liquefied gas such as liquid ammonia.

[0229] The auxiliary barrier 2 and the external waterproof membrane 4 were initially a sealed tank used for the storage of a first liquefied gas such as LNG. The process for adapting said sealed tank will be exemplified below.

[0230] The supporting structure 3 may in particular be formed from self-supporting metal sheets or, more generally, from any type of rigid partition having appropriate mechanical properties, such as a concrete partition or a partition formed by the double hull of a ship.

[0231] The auxiliary barrier 2 is thermally insulating and is fixed to the supporting structure 3 and comprises, for example, a plurality of thermally insulating panels (not shown) anchored to the supporting structure 3.

[0232] The auxiliary barrier 2 may further comprise a secondary flexible membrane made of composite material (not shown) glued against the thermally insulating panels.

[0233] The auxiliary barrier 2 may further comprise a second layer of thermally insulating panels glued against the secondary flexible membrane.

[0234] The outer waterproof membrane 4 is metallic, preferably made of stainless steel. The outer waterproof membrane 4 comprises parallel corrugations 14 and flat areas 15 defined between the corrugations 14. The corrugations 14 protrude from the flat areas 15 towards the interior of the tank.

[0235] Similarly, the internal waterproof membrane 6 is metallic, preferably made of stainless steel. The internal waterproof membrane 6 comprises parallel corrugations 16 and flat areas 17 defined between the corrugations 16. The corrugations 16 project from the flat areas 17 towards the interior of the tank.

[0236] The corrugations 16 and the corrugations 14 as well as the flat areas 17 and the flat areas 15 are respectively located opposite each other.

[0237] Tank walls according to several embodiments will be described in more detail below.

[0238] In Figures 2 to 4, elements identical or similar to those of the bear the same reference numbers incremented by 100.

[0239] In relation to Figures 2 to 4, a first variant of a sealed tank wall 101 for storing liquefied gas such as ammonia obtained by one embodiment of the method is described below.

[0240] The tank wall 101 comprises an external waterproof membrane 104 comprising a series of small parallel corrugations 114 and further comprising a series of large corrugations 118 perpendicular to the small corrugations 114. The large corrugations 118 and the small corrugations 114 project towards the interior of the tank. The large corrugations 118 have a height greater than the height of the small corrugations 114.

[0241] Flat areas 115 are defined between the small undulations 114 and between the large undulations 118.

[0242] A spacer block 105 is located on the flat area 115 of the external waterproof membrane 104, as seen for example in Figures 2 and 4. The thickness of the spacer block 105 is here between the height of the small undulations 114 and the height of the large undulations 118.

[0243] The spacer block 105 has an outer end 130 positioned against the flat area 115, a flat inner face 131 parallel to the outer end 130 positioned against the flat area 117 of the inner waterproof membrane 106 and four lateral ends connecting the outer end 130 to the inner face 131.

[0244] The contour of the outer end 130 substantially corresponds to the contour of the flat area 115 and does not touch the feet of the small corrugations 114 and the large corrugations 118. A foot of a corrugation can be defined as the area in which the waterproof membrane deflects towards the internal space of the tank. This deflection area is located between the corrugation and the flat area of ​​the waterproof membrane.

[0245] The four lateral ends develop between the external end 130 and the internal face 131 of the spacer block 105 and comprise: two lateral ends 132 facing each other and extending parallel to the small undulations 114, that is to say in the longitudinal direction of the small undulations 114, and two second lateral ends 133 facing each other and extending parallel to the large undulations 118, that is to say in the longitudinal direction of the large undulations 118. The lateral ends do not touch said undulations.

[0246] The two lateral ends 132 are turned respectively towards two small corrugations 114 without touching the two small corrugations 114. The first two lateral ends 132 develop towards the outside of the spacer block 105 so that the internal face 131 has a larger dimension than the external end 130 in a direction transverse to the small corrugations 114, that is to say in a direction parallel to the large corrugations 118, so that two opposite end portions of the internal face 131 each partially overhang the adjacent small corrugation 114 and support a foot of a corrugation 116 of the internal waterproof membrane 106. The first two lateral ends 132 have a concave shape which at a distance matches the shape of a portion of the small corrugation 114.

[0247] The spacer block 105 further comprises a plurality of support ribs 134 which form hollow cells 135. The hollow cells 135 have the shape of a plurality of aligned rectangular compartments. The plurality of support ribs 134 notably allows the spacer block 105 to support the internal waterproof membrane 106 and to resist the hydrostatic pressure forces exerted against the spacer block 105.

[0248] The spacer block 105 has a temporary orifice 121 which passes through the thickness of the spacer block 105, and in the middle of the spacer block 105, in order to allow the spacer block 105 to be fixed against the flat area 115.

[0249] The spacer block 105 is fixed against said flat area 115 via a screw-nut system, visible on the. Other fixing systems can also be used.

[0250] In order to fix the spacer block 105, a threaded rod 120 is welded to the flat area 115 of the outer waterproof membrane 104, for example via the capacitor discharge welding method, so that the threaded rod 120 projects upwards, i.e., projects towards the inside of the tank. The spacer block 105 is then positioned on the flat area 115 by inserting the threaded rod 120 into the temporary hole 121. The spacer block 105 is then fixed via a retaining surface cooperating with a nut 122.

[0251] After fixing the spacer block 105 against the flat area 115, the temporary orifice 121 is closed by a metal cover 123 so that the internal face 131 is flat in order to best support the internal waterproof membrane 106. The metal cover is for example made of aluminum or stainless steel.

[0252] The flat area 117 of the internal waterproof membrane 106 rests against the flat internal face 131 and is fixed to the spacer block 105. The fixing is for example carried out by welding on a metal insert positioned at the level of the internal face 131. The metal insert is for example the metal cover 123 which is fixed against a fixing portion 119 on the flat internal face 131. It should be noted that the metal insert can also be positioned at another position on the internal face 131.

[0253] Illustrates an alternative embodiment of the spacer block. In the, elements identical or similar to those of figures 2 to 4 bear the same reference numbers incremented by 100.

[0254] The spacer block 205 differs from the spacer block of Figures 2 to 4 in that the two lateral ends 232 facing each other have a greater curvature. In addition, the through hole 221 has a different shape and includes a retaining surface 224 cooperating with a threaded rod 220 and a nut 222 mounted on the threaded rod 220. The spacer block 205 includes a smaller number of support ribs 234 and therefore hollow cells 235.

[0255] The spacer blocks described above cover a single flat area of ​​the external waterproof membrane. However, a spacer block can have larger dimensions, particularly so as to cover several flat areas.

[0256] Figures 6 and 7 illustrate two variant embodiments of the spacer block covering several flat areas. In Figures 6 and 7, elements identical or similar to those of Figures 2 to 4 bear the same reference numbers incremented by 200.

[0257] The spacer block 305 of the diffres from the spacer block of Figures 2 to 4 in that the spacer block 305 is positioned on two adjacent flat areas 315 of the outer waterproof membrane 304 separated by a small corrugation 314. Each flat area is delimited by two adjacent large corrugations 318 and two adjacent small corrugations 314. The outer end 330 of the spacer block 305 comprises two flat portions each positioned on a flat area 315. The outer end 330 of the spacer block 305 further comprises a connecting portion 340 which connects the two flat portions. The connecting portion 340 extends over the small corrugation 314. In other words, the connecting portion 340 forms a tunnel crossed by the small corrugation 314, over the entire dimension of the spacer block 305.

[0258] The spacer block 305 has a thickness greater than the height of the large corrugations 318. The outer end 330 of the spacer block 305 comprises four flat portions each positioned on a flat area 315. The outer end 330 of the spacer block 305 further comprises connecting portions which connect the four portions of the outer end 330. The connecting portions extend over a small corrugation 314 or a large corrugation 318. In other words, a first connecting portion 340 of the spacer block 305 forms a tunnel crossed by the large corrugation 318, over the entire length of the spacer block 305. A second connecting portion 341 forms a tunnel crossed by the small corrugation 314, over the entire width of the spacer block 305. The inner face 331 of the spacer block has a larger dimension than the outer end 330. Each of the four edges of the inner face 331 partially overhangs a corrugation.

[0259] Illustrates an alternative embodiment of the spacer block. In the, elements identical or similar to those of figures 2 to 4 bear the same reference numbers incremented by 300.

[0260] The two spacer blocks 405 differ from the spacer block of Figures 2 to 4 in that they are located at a corner of the tank. The flat areas 415 of the external sealing membranes 404 are located between a corrugation 414 and the corner of the tank.

[0261] The spacer blocks 405 are each positioned on a flat area 415, at the angle and each have a beveled lateral end 432b located opposite the lateral end 432. The beveled lateral ends 432b of the spacer blocks 405 are positioned in abutment against each other. It is illustrated on the a tank angle at 90° with the beveled lateral ends 432b at 45° but such an arrangement can be adapted to be positioned at another tank angle, such as an angle of 135° for example. In addition, the two beveled lateral ends 432b can have a different bevel angle from each other, as long as their meeting forms an angle corresponding to the angle of the tank

[0262] According to one embodiment, the tank wall described above can be obtained from a pre-existing sealed and thermally insulating tank wall for LNG storage, in which the spacer blocks 5, 105 or 205 and the internal sealed membrane 6, 106, 206 have been installed. Many structures exist in the state of the art for the sealed and thermally insulating tank wall for LNG storage. According to one embodiment, the sealed and thermally insulating tank wall for LNG storage complies with publications FR2739675 or WO2022200539. Thus, further details regarding the auxiliary barrier 2 and the external sealed membrane 4, 104, 204 can be found in these publications.

[0263] Two other variant embodiments are illustrated below with figures 9 to 23.

[0264] A wall 501 is illustrated which is waterproof and thermally insulating. The wall 501 is intended to be fixed to a supporting structure to construct a tank for storing and / or transporting liquefied gas, such as liquid hydrogen.

[0265] The wall 501 is a multi-layer structure comprising, along a thickness direction of the wall 501, a thermally insulating barrier comprising a metal anchoring strip 502 onto which a waterproof membrane 503 is welded, a primary thermally insulating barrier 504 and a primary waterproof membrane 505.

[0266] The thermally insulating barrier and the waterproof membrane 503 was initially a tank wall integrated into a sealed tank intended for the storage of a first liquefied gas such as LNG. The process for adapting said sealed tank will be exemplified below.

[0267] The primary thermally insulating barrier 504 comprises spacer blocks. In this embodiment, the spacer blocks are primary thermally insulating panels 41 held against the waterproof membrane 503 by a primary coupler 506 and further comprises thermally insulating seals 49 located in the spaces between two adjacent primary thermally insulating panels 41. In an alternative embodiment, the primary thermally insulating panels 41 are replaced by primary thermally insulating boxes.

[0268] The primary thermally insulating panels 41 comprise a layer of polymer foam 42 sandwiched between an external rigid plate 43 and an internal rigid plate 44. The external rigid plate 43 and the internal rigid plate 44 are for example made of plywood.

[0269] The different elements of wall 501 will be described in more detail below.

[0270] The metallic waterproof membrane 503 comprises first corrugations 38 parallel to each other and second corrugations 39 parallel to each other and perpendicular to the first corrugations 38. The first corrugations 38 are higher than the second corrugations 39. Flat areas 37 are located between two adjacent first corrugations 38 and two adjacent second corrugations 39. The primary thermally insulating panels 41 comprise grooves 46 machined on the external face in order to receive and match the shape of the first and second corrugations 38, 39.

[0271] The metallic waterproof membrane 503 is formed by an assembly of a plurality of metal sheets 31, 32, 33, 34 welded together in a sealed manner by overlapping. For example, the second and third adjacent metal sheets 32, 33 are welded by overlapping an edge of the first adjacent metal sheet 31. The fourth metal sheet 34 is welded to the second and third adjacent metal sheets 32, 33 by overlapping at an edge of the second and third metal sheets 32, 33.

[0272] Depending on the variants, different covering configurations can be envisaged.

[0273] The metallic waterproof membrane 503 is further welded to anchoring strips 502 positioned on an internal face of thermally insulating panels of the thermally insulating barrier.

[0274] As illustrated in particular in Figures 10 and 12, a junction zone II is formed by the junction of a first corner zone of the first metal sheet 31, a second corner zone of the second metal sheet 32, a third corner zone of the third metal sheet 33 and a fourth corner zone of the fourth metal sheet 34. The corner zones are machined and arranged by overlapping one another, so as to leave a portion of the anchoring strip 502 accessible for fixing the primary coupler 506. The junction zone II is positioned at a distance from the first and second corrugations 38, 39, at a flat zone 37 of the intermediate metal waterproof membrane 503.

[0275] In an alternative embodiment illustrated with 1a, a joining zone III may be formed by joining a first corner zone of the first metal sheet 531, a second corner zone of the second metal sheet 532 and a machined edge of the third metal sheet 533 so as to leave a portion of the anchoring strip 502 accessible for fixing the primary coupler 506.

[0276] As illustrated in particular in Figures 9 and 14 to 20, the primary coupler 506 is located between four primary thermally insulating panels 41 and allows the anchoring of the four primary thermally insulating panels 41.

[0277] The primary coupler 506 comprises an external metal plate 61 of rectangular shape with rounded edges which is welded against the junction zone II, on the anchor strip portion 502.

[0278] As illustrated in Figures 13 to 18, the primary coupler 506 comprises a threaded stud 62 having an external end which is welded against an internal face of the external metal plate 61 so that the threaded stud 62 projects towards the primary waterproof membrane 505. The threaded stud 62 is preferably centered on the external metal plate 61 and located opposite the portion of the anchoring strip 502.

[0279] As illustrated in Figures 15 to 18, the primary coupler 506 comprises a preferably metallic support plate 63 comprising a through hole 64 mounted on the threaded stud 62.

[0280] The corners of the primary thermally insulating panels 41 each comprise a machined portion 45 so as to form a well allowing the insertion of the support plate 63 against a corner portion of the external rigid plates 43.

[0281] In practice, the backing plate 63 is positioned over the outer metal plate 61 and sandwiches a corner portion of each of the outer rigid plates 43 of the four primary thermally insulating panels 41 located around the primary coupler 506. The backing plate 63 is secured against the corner portions of the outer rigid plates 43 by a fastener 65, for example via a nut mounted on the thread of the threaded stud 62 and tightened against the backing plate 63. Optionally, a Belleville washer 66 is located between the fastener 65 and the backing plate 63.

[0282] A plug 7 is positioned over the primary coupler 506. The plug 7 comprises a main body 91 having the shape of a rectangular parallelepiped filling the space formed between the primary thermally insulating panels 41 at the primary coupler 506. The main body has a thickness of approximately the thickness of the polymer foam layer 42.

[0283] The plug 7 further comprises an internal cover plate 92 located at an internal end of the main body 91. The internal cover plate 92 is made of a rigid material such as plywood and comprises a rectangular metal sheet 93 onto which the primary waterproof membrane 505 is welded.

[0284] The inner cover plate 92 has a portion positioned in counterbores 47 formed at the corners in the inner rigid plates 44. The inner cover plate 92 forms a flat surface with the four inner rigid plates 44 of the adjacent primary thermally insulating panels 41 to provide support for the primary waterproof membrane 505.

[0285] Internal thermal protection strips are located between the primary thermally insulating barrier 504 and the primary waterproof membrane 505 to protect the primary thermally insulating barrier 504 from significant temperature increases when the primary waterproof membrane 505 is installed by welding onto the primary thermally insulating barrier 504.

[0286] Indeed, the primary waterproof membrane 505 is formed by an assembly of primary metal sheets 51, 52, 53, 54 welded together in a waterproof manner by overlapping. For example, the second and third adjacent primary metal sheets 52, 53 are welded by overlapping an edge of the first adjacent primary metal sheet 51. The fourth primary metal sheet 54 is welded to the second and third adjacent primary metal sheets 52, 53 by overlapping at an edge of the second and third primary metal sheets 52, 53.

[0287] Depending on the variants, different covering configurations can be envisaged.

[0288] Similar to the metallic waterproof membrane 503, the primary metallic waterproof membrane 505 comprises first corrugations 58 parallel to each other and second corrugations 59 parallel to each other and perpendicular to the first corrugations 58. The first corrugations 58 are higher than the second corrugations 59. Flat areas 57 are located between two adjacent first corrugations 58 and two adjacent second corrugations 59.

[0289] The primary metal sheets 51, 52, 53, 54 of the primary waterproof membrane 505 are welded to the rectangular metal sheet 93 at a primary junction zone IV, notably illustrated in the.

[0290] The primary joining area IV is formed by welding a first corner area of ​​the first primary metal sheet 51, a second corner area of ​​the second primary metal sheet 52, a third corner area of ​​the third primary metal sheet 53 and a fourth corner area of ​​the fourth primary metal sheet 54, onto the rectangular metal sheet 93.

[0291] The primary metal sheets 51, 52, 53, 54 are located opposite the metal sheets 31, 32, 33, 34 of the waterproof membrane 503. In other words, the first corrugations 58 are located opposite the first corrugations 38, the second corrugations 59 are located opposite the second corrugations 39 and the flat areas 57 are located opposite the flat areas 37.

[0292] Figures 9 to 20 illustrate corner portions of the primary thermally insulating panels 41, the metal sheets 31, 32, 33, 34 and the primary metal sheets 51, 52, 53, 54.

[0293] In connection therewith, the overall structure of a primary thermally insulating panel 41 is illustrated. In particular, it is illustrated that the corner portion described above is repeated at the four corners of the primary thermally insulating panel 41 in order to allow the fixing of the primary thermally insulating panel 41 by a primary coupler 506 and the installation of the plug 7 as described above, at each corner of the primary thermally insulating panel 504.

[0294] This configuration makes it possible to juxtapose the primary thermally insulating panels 504 in a regular pattern to assemble the wall 1, as illustrated in particular with the. The primary thermally insulating panels 504 further comprise anchoring plates 48 on which the primary waterproof membrane 505 can be welded via welding points 55.

[0295] In connection with the, the overall structure of the primary metal sheet 51 is illustrated. The primary metal sheets 52, 53, 54 and possibly the metal sheets 31, 32, 33, 34 may have the same characteristics.

[0296] In connection with the, the wall 501 is illustrated in which the primary thermally insulating panels 504 have dimensions adapted to individually cover a metal sheet 31, 32, 33, 34. Primary couplers 506 and plugs 7 as described previously are positioned at each of the corners of the primary thermally insulating panels 504 and at each junction zone of four metal sheets, several metal sheets of which have been deliberately omitted on the.

[0297] In addition and by way of example, the thermally insulating barrier (not shown) may be a sealed and thermally insulating barrier comprising a plurality of modular blocks (not shown) of generally parallelepiped shape.

[0298] A modular block of the wall comprises, from the outside to the inside of the installation: a first thermally insulating layer having, for example, the shape of a secondary insulating panel of parallelepiped shape and forming part of a secondary thermally insulating barrier, a portion of secondary waterproof membrane covering the secondary insulating panel, a second intermediate thermally insulating layer having, for example, the shape of an insulating panel of parallelepiped shape which rests on the portion of secondary waterproof membrane.

[0299] The intermediate insulating panel further comprises metal anchor strips 502 to which the metal waterproof membrane 503 is welded as well as relaxation slots (not shown). This intermediate insulating panel has dimensions smaller than the dimensions of the secondary insulating panel so as to leave a peripheral edge of the intermediate waterproof membrane portion uncovered.

[0300] In order to form the wall, the modular blocks are in particular juxtaposed in a regular pattern. The continuity of the secondary waterproof membrane is ensured by waterproof connecting strips (not shown) connecting the peripheral edges of the secondary waterproof membrane portions of the adjacent modular blocks. In addition, intermediate insulating panels (not shown) are arranged between the intermediate insulating panels of the modular blocks in order to complete the intermediate thermally insulating barrier and form a flat support surface for the metallic waterproof membrane 503.

[0301] The secondary insulation panel is, for example, made of a block of polymer foam, for example polyurethane. The intermediate insulation panel is, for example, made of a block of polymer foam, for example polyurethane.

[0302] By way of example, modular blocks suitable for the present invention are for example described in patent application WO2015197638 under the name “prefabricated panels” or in patent application FR2691520 under the name “prefabricated structure”.

[0303] Such a wall 501 may in particular be manufactured from a pre-existing wall initially intended to store LNG. Such a wall initially comprises a aforementioned thermally insulating barrier, with an anchoring strip 502 and a waterproof membrane such as the waterproof membrane 503 but does not comprise the elements located above this waterproof membrane, that is to say which does not comprise the aforementioned primary coupler 506, the plug 7, the primary thermally insulating panels 504 and the primary waterproof membrane 505.

[0304] In this case, the method of manufacturing the wall 501 may follow the steps illustrated with figures 12 to 20, that is to say:- adding the external metal plate 61 of the primary coupler 506 at the junction area II, as illustrated in the,- welding the threaded stud 62, as illustrated in the,- adding the primary thermally insulating panels 504, as illustrated in the,- fixing the primary thermally insulating panels 504 by adding the backing plate 63, as illustrated in the,- tightening and fixing the backing plate 63 against the external rigid plates 43 of the primary thermally insulating panels 504 via a fixing element 65, as illustrated in the,- optionally, adding the thermally insulating gaskets 49, as illustrated in the,- inserting the plug 7 to fill a gap formed between the primary thermally insulating panels 504 at the primary coupler 506, as illustrated in the, - optionally,add the internal thermal protection strips 8, as shown in the,- add and fix the primary waterproof membrane 505 against the primary thermally insulating panels 504, at the primary junction zone IV, as shown in the, in order to obtain the wall 501.,

[0305] With reference to the, a cutaway view of a ship 70 shows a sealed and thermally insulating tank 71 of generally prismatic shape mounted in the double hull 72 of the ship. The wall of the tank 71 comprises a primary sealing membrane intended to be in contact with the liquefied gas contained in the tank, a secondary sealing membrane arranged between the primary sealing membrane and the double hull 72 of the ship, and two thermally insulating barriers arranged respectively between the primary sealing membrane and the secondary sealing membrane and between the secondary sealing membrane and the double hull 72.

[0306] In a manner known per se, loading / unloading pipes 73 arranged on the upper deck of the ship can be connected, by means of appropriate connectors, to a maritime or port terminal to transfer a cargo of liquefied gas from or to the tank 71.

[0307] It also represents an example of a maritime terminal comprising a loading and unloading station 75, an underwater pipeline 76 and an onshore installation 77. The loading and unloading station 75 is a fixed offshore installation comprising a mobile arm 74 and a tower 78 which supports the mobile arm 74. The mobile arm 74 carries a bundle of insulated flexible pipes 79 which can be connected to the loading / unloading pipelines 73. The orientable mobile arm 74 adapts to all vessel sizes. A connecting pipe, not shown, extends inside the tower 78. The loading and unloading station 75 allows the loading and unloading of the ship 70 from or to the onshore installation 77. The latter comprises liquefied gas storage tanks 80 and connecting pipes 81 connected by the underwater pipe 76 to the loading or unloading station 75.The subsea pipeline 76 allows the transfer of liquefied gas between the loading or unloading station 75 and the onshore installation 77 over a long distance, for example 5 km, which makes it possible to keep the vessel 70 at a great distance from the coast during loading and unloading operations.

[0308] To generate the pressure necessary for the transfer of the liquefied gas, it is possible either to use pumps on board the ship 70 and / or pumps fitted to the onshore installation 77 and / or pumps fitted to the loading and unloading station 75 or to allow a rise in pressure in the interior space of the tank under the effect of the evaporation of the liquefied gas stored in the tank.

[0309] Although the invention has been described in connection with several particular embodiments, it is obvious that it is in no way limited thereto and that it includes all technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

[0310] The use of the verb “comport” or “comprendre” and its conjugated forms does not exclude the presence of other elements or other steps than those stated in a claim.

[0311] In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims

A method for adapting a sealed tank initially used for the storage of a first liquefied gas, the method comprising:fixing a spacer block (5, 41, 105, 205, 305, 405) on at least one flat area (15, 115, 215, 315, 415) of an external sealed membrane (4, 104, 204, 304, 404), in which the external sealed membrane is a primary membrane belonging to a sealed tank wall (1, 101, 201, 301, 401) for the storage of the first liquefied gas, the external sealed membrane being metallic; the spacer block having an outer end (130, 230, 330, 430), a flat inner face (131, 231, 331, 431) parallel to the outer end and lateral ends (132, 133, 232, 332, 432) connecting the outer end to the inner face, the outer end being positioned against said at least one flat area;and arranging at least one flat area (17, 37, 117, 317) of an internal metallic sealing membrane (6, 106, 206, 306) against the internal face of the spacer block, such that the internal sealing membrane is spaced from the external sealing membrane by the spacer block.; The method of claim 1, wherein the outer waterproof membrane comprises a first series of parallel corrugations (14, 38, 114, 214, 314, 414), the spacer block being positioned such that a first one of the lateral ends (132, 232, 332, 432) of the spacer block extends parallel to a first corrugation of the first series of corrugations. The method of claim 2, wherein the first lateral end of the spacer block is positioned so as not to be in contact with the first corrugation. Method according to one of claims 2 to 3, wherein said at least one flat zone comprises a first flat zone and wherein the spacer block has a thickness greater than a height of the first series of corrugations in the thickness direction of the tank wall and wherein the outer end of the spacer block is arranged on at least one second flat zone (15, 115, 215, 315, 415) of the outer waterproof membrane, the spacer block extending over at least one other corrugation (14, 38, 114, 214, 314, 414) of the first series of corrugations located between said first flat zone and said second flat zone. Method according to one of claims 2 to 4, in which the external waterproof membrane comprises a second series of corrugations (39, 118, 218, 318) perpendicular to the first series of corrugations, in which a height of the first series of corrugations is less than a height of the second series of corrugations in the thickness direction (E) of the tank wall. The method of claim 5, wherein the spacer block has a thickness between the height of the second series of undulations and the height of the first series of undulations. A method according to claim 5, the spacer block has a thickness greater than a height of the second series of corrugations in the thickness direction of the tank wall and wherein the outer end of the spacer block is arranged on at least one other flat area (15, 37, 115, 215, 315, 415) of the outer sealing membrane, the spacer block extending over another corrugation (39, 118, 218, 318) of the second series of corrugations located between said first flat area and said other flat area. Method according to one of claims 2 to 7, in which the spacer block comprises support ribs (134, 234) located under the internal face between the lateral ends and hollow cells (135, 235) located between the support ribs. A method according to claim 8, wherein the outer end of the spacer block is formed by edges of the side ends and / or end edges of the support ribs, the hollow cells being open at the outer end of the spacer block. Method according to one of claims 8 to 9, wherein the first lateral end is formed by lateral edges of the support ribs. Method according to one of claims 2 to 10, in which the first of the lateral ends faces a first corrugation of the first series of corrugations, the internal face comprising a first end portion partially overhanging the first corrugation. Method according to one of claims 1 to 11, the method comprising before the step of fixing the spacer block: fixing a fixing piece to the flat area of ​​the external waterproof membrane and projecting towards the internal waterproof membrane, the spacer block being fixed to the fixing piece. The method of claim 12, wherein the spacer block has a retaining surface (224), and wherein the spacer block is mounted on the fastener that extends through the retaining surface 224, the method comprising adding a nut (122, 222) or clip mounted on the fastener and cooperating with the fastener (120, 220) and the retaining surface (224) to secure the spacer block to the at least one planar area (15, 37, 115, 215, 315, 415). The method of claim 12, wherein the fastener is a primary coupler, the primary coupler comprising a stud and a backing plate (63), the method comprising:fastening the stud to the flat area of ​​the outer waterproof membrane so as to project towards the inner waterproof membrane, positioning the spacer block on the at least one flat area and then mounting the backing plate (63) on the stud so as to retain the spacer block against the at least one flat area. Method according to one of claims 1 to 14, in which the internal waterproof membrane comprises a first series of undulations (16, 116, 216, 316) parallel to the first series of undulations of the external waterproof membrane and flat zones (17, 117), at least one undulation of the first series of undulations of the internal waterproof membrane being opposite the first undulation of the first series of undulations of the external waterproof membrane in the thickness direction of the tank wall. Method according to one of claims 1 to 15, in which the spacer block comprises aluminum, a thermoplastic or thermosetting material. Method according to one of claims 1 to 15, in which the spacer block is chosen from: a primary thermally insulating panel or a primary thermally insulating box. A method according to claim 17, wherein the primary thermally insulating panel comprises a layer of polymer foam (42) sandwiched between an outer rigid plate (43) and an inner rigid plate (44). Method according to one of claims 1 to 18, wherein the sealed tank wall (1, 101, 201, 301, 401) for storing the first gas comprises, in the thickness direction of the wall, from the outside to the inside of the tank: a thermally insulating barrier and the primary sealed membrane located against the thermally insulating barrier. A method according to claim 19 in combination with claims 14 and 18, wherein the thermally insulating barrier comprises an inner metal anchor strip (2),the outer waterproof membrane comprising a first metal sheet (31, 131) and a second metal sheet (32, 132), the second metal sheet being adjacent to the first metal sheet at a junction area (II, III), the outer waterproof membrane being fixed to the inner metal anchor strip at the junction area,the primary coupler (6) comprising an outer metal plate (61) welded to the junction area, the stud being fixed so as to project from an inner face of the outer metal plate in the thickness direction of the wall,wherein a primary thermally insulating barrier is positioned against the outer waterproof membrane,the primary thermally insulating barrier comprising primary thermally insulating panels (41) retained against the external waterproof membrane by the backing plate., A method according to claim 20, wherein at least one primary thermally insulating panel has, in an area adjacent to the primary coupler (6), a well formed through the polymer foam layer (42) and the inner rigid plate (44) to expose a bearing portion of the outer rigid plate (43), and wherein the bearing plate (63) is positioned so as to be engaged with the bearing portion of the outer rigid plate (43). A method according to claim 21, wherein the adjacent primary thermally insulating panels are each positioned on a respective flat area of ​​the outer waterproof membrane, the method comprising, before arranging the inner waterproof membrane: inserting a plug (7) filling a space formed between said primary thermally insulating panels at the primary coupler, the plug comprising an inner cover plate (92) intended to form a flat surface with the inner rigid plates of the primary thermally insulating panels. Method according to one of claims 19 to 22, in which the thermally insulating barrier is an intermediate thermally insulating barrier, the waterproof membrane (3) is an intermediate waterproof membrane, the wall further comprising a secondary waterproof membrane intended to be arranged between the intermediate waterproof membrane and the supporting structure and a secondary thermally insulating barrier intended to be arranged between the secondary waterproof membrane and the supporting structure. Method according to one of claims 1 to 23, in which the first gas is liquefied natural gas, and in which the tank obtained is intended to receive liquid ammonia.

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