Sealed insulated tank

Abstract

The present invention mainly relates to a sealed and insulated tank for transporting and / or storing liquefied natural gas, comprising at least one supporting structure (4) and a storage structure (2) surrounded by the supporting structure (4), the storage structure (2) comprising at least one first portion (46) and a second portion (48) sealed relative to each other, the first portion (46) and the second portion (48) extending at least partially in the same plane parallel to the supporting structure (4), the storage structure (2) having a thickness from the outside to the inside of the tank (1) along a direction perpendicular to the plane of the supporting structure (4), the tank (1) comprising a storage structure at least partially arranged in the storage structure (4). A closure device (58) in the thickness of a storage structure (2), the closure device (58) comprising at least one first closure member and one second closure member, the first closure member and the second closure member being configured to cooperate with each other so as to separate a first part (46) from a second part (48), at least one of the closure members comprising a first part and a second part extending in intersecting planes, characterized in that at least one of the sections of one and / or the other of the closure members is connected to at least one of the parts (46, 48) by a fastening device (84), which is arranged in the thickness of the storage structure (2).

Description

Technical Field

[0001] The present invention relates to the field of liquefied natural gas storage tanks, in particular to land-based liquefied natural gas storage tanks. Background Art

[0002] Liquefied natural gas (LNG) is typically transported by sea in tanks mounted on carriers. Natural gas is stored in liquid form to increase the amount of gas that can be transported per tank. The volume of one liter of liquefied natural gas is much lower than that of one liter of gaseous natural gas. These tanks keep the LNG at very low temperatures—more precisely, below -163°C, at which point it is liquid at atmospheric pressure.

[0003] To load and / or unload the tanks of these LNG carriers, onshore LNG storage tanks are installed at ports. These are typically configured to allow LNG carriers to access and reload and / or unload their LNG cargoes. These onshore storage tanks are equipped with elements, such as pipes, that penetrate one of the walls of the onshore tanks, allowing communication between the LNG loading and / or unloading facilities and the interior volume of the onshore tanks, where the LNG is stored and / or unloaded.

[0004] As is well known, such onshore tanks include a storage structure for containing liquefied natural gas (LNG) and a support structure surrounding the storage structure. The walls of the storage structure typically include at least a sealed and insulated secondary space and a sealed and insulated primary space, the primary space being located above the secondary space and configured to contact the LNG contained in the tank. In some cases, the storage structure may include a wall having a first portion consisting of at least the secondary space and the primary space, and a second portion comprising a sealing insulating layer, the sealing insulating layer being in contact with the support structure on one hand and with the LNG on the other hand. This type of assembly can be positioned to facilitate penetration of the penetrating element through the wall, more specifically, at the sealing insulating layer.

[0005] A closure device is typically installed at the junction between the first and second parts to seal the secondary space of the first part, thereby isolating the secondary space from the second part. However, such closure devices are often complex to install and / or require considerable precision when assembling the walls of the tank storage structure. Since such precision is often difficult to achieve with large steel or concrete tanks, a space remains between the closure device and the components of the secondary space, which must be filled to limit thermal bridges. Summary of the Invention

[0006] In this context, the present invention proposes an alternative to existing solutions, which rely on closing means that adapt to the position of the secondary space during assembly of the walls of the storage structure.

[0007] To this end, the main subject of the present invention is a sealed, insulated tank for transporting and / or storing liquefied natural gas, comprising at least one supporting structure and a storage structure surrounded by the supporting structure, the storage structure comprising at least a first part and a second part sealed relative to each other, the first part and the second part extending at least partially in the same plane parallel to the supporting structure, the storage structure having a thickness from the outside of the tank towards the inside in a direction perpendicular to the plane of the supporting structure, the tank comprising a closing device at least partially arranged in the thickness of the storage structure, the closing device comprising at least a first closing member and a second closing member, the first closing member and the second closing member being configured to interact with each other in a manner that separates the first part from the second part, at least one of the closing members comprising a first segment and a second segment extending in mutually separated planes, characterized in that at least one of the segments of one closing member and / or another closing member is connected to at least one of the parts by a fixing device arranged in the thickness of the storage structure.

[0008] The tank storage structure includes a plurality of walls, each of which includes at least a first portion and a second portion. According to the present invention, one of the plurality of walls includes a section where the first portion and the second portion extend in the same plane parallel to the support structure. Note that in this case, the first portion and the second portion are aligned relative to each other while their internal volumes remain independent because the first portion is sealed relative to the second portion.

[0009] The term "thickness" refers to a dimension of the element measured in a direction perpendicular to the supporting structure of the first and second parts, and this thickness may be a section of one or the other part located in this direction. In addition, at least one of the sections of one and / or the other of the closure members extends in the thickness direction in the area located between the first and second parts, and the fixing device fixes it to at least one of the sections in the thickness direction.

[0010] According to an optional feature of the invention, at least one of the closure members has an "L" shaped profile in a cross section through the closure device.

[0011] According to an optional feature of the invention, the first and second closure members have an "L" shaped profile, seen in section through the closure arrangement.

[0012] According to another optional feature of the invention, the first section of one of the closure members extends perpendicularly relative to the second section of the closure member.

[0013] According to another optional feature of the invention, at least one of the closure members is fixed to the other closure member by at least one weld. The weld also ensures a seal between the two closure members, thereby preventing any fluid exchange between the first part and the second part.

[0014] According to another optional feature of the invention, the second section of one closure member is secured to the second section of the other closure member by a weld.

[0015] According to another feature of the invention, the first and second closing members are positioned end to end relative to each other.

[0016] According to another feature of the invention, the second section of the first closure member extends parallel to the second section of the second closure member, the second sections of the closure members are connected to each other, and the other two sections of the closure members extend away from each other in mutually parallel planes.

[0017] According to another optional feature of the present invention, the first and / or second closure members of the closure device are elastically deformable. Elastic deformation means that each closure member visibly changes shape when pressure is applied and returns to its original shape when the pressure is removed. This feature allows the first and second closure members to match the expansion or contraction of the first and / or second portions.

[0018] According to another characteristic of the invention, one closing member is connected to at least one of the portions by fixing means arranged in the thickness of the storage structure, and the other closing member is connected to the supporting structure.

[0019] According to another optional feature of the invention, one of the closing members is connected to at least one of the parts by fixing means provided in the thickness of the supporting structure, the supporting structure comprising an insert at which one or another section of the other closing member is fixed.

[0020] According to another optional feature of the present invention, the first part includes a secondary space and a primary space, the secondary space includes, in sequence from the outside to the inside of the tank in the thickness direction, a secondary insulation barrier suitable for contacting the support structure and a secondary sealing membrane resting on the secondary insulation barrier, the fixing device extends at least partially into the secondary insulation barrier, the primary space includes, in sequence from the outside to the inside of the tank in the thickness direction, a primary insulation barrier resting on the secondary sealing membrane and a primary sealing membrane resting on the primary insulation barrier and used for contacting the fluid contained in the tank, the second part includes an insulation wall suitable for contacting the support structure and an impermeable membrane resting on the insulation wall and used for contacting the fluid contained in the tank.

[0021] According to this characteristic, the tank thus comprises a section of its wall where the primary and secondary spaces overlap, and a section of its wall provided only with a sealing thermal insulation layer, the secondary space being closed by the closure device according to the invention. The volume of the second portion communicates with the volume of the primary space of the first portion of the support structure, in such a way that the same inert fluid, in particular molecular nitrogen, can pass through this common volume.

[0022] According to another optional feature of the invention, the secondary space includes a fixing plate arranged between the secondary insulation barrier and the primary space, a first section of the first closing member is connected to the fixing plate by at least one weld, and a second section of the first closing member is connected to the secondary insulation barrier by a fixing device arranged in the thickness of the storage structure.

[0023] According to another optional feature of the invention, the first section of the first closure member is connected to the fixing plate by at least one weld, the fixing plate and the first closure member being configured to be integrally mounted on the secondary insulation barrier.

[0024] According to another optional feature of the invention, the supporting structure comprises an insert, the first section of the second closing member being connected to the insert by at least one weld, and the second section of the second closing member being connected to the secondary insulation barrier by fixing means arranged in the thickness of the storage structure.

[0025] According to another optional feature of the invention, at least the secondary space includes at least one insulating self-supporting panel having an interior face oriented toward the interior of the tank, an exterior face oriented toward the exterior of the tank, and a thickness face extending between the interior face and the exterior face of the self-supporting panel, the self-supporting panel of the secondary space adjacent the first closure member including an inclined face connecting the interior face and the thickness face of the self-supporting panel. According to an optional feature of the invention, the thickness face of the self-supporting panel includes a plywood panel for receiving the fixing means.

[0026] According to another optional feature of the present invention, the first closing member includes a curved section connecting the first section of the first closing member to the second section, and the first closing member is positioned against the inner surface and thickness surface of the self-supporting panel of the secondary space, so that the curved section of the first closing member is arranged corresponding to the inclined surface on the self-supporting panel.

[0027] As a second subject, the invention also relates to a transport and / or storage unit comprising at least one tank according to any of the preceding features, the transport and / or storage unit comprising a ship, a barge, a reliquefaction unit, a gasification unit, an onshore structure or a gravity platform.

[0028] As a third subject, the invention also relates to a method for assembling a joint area between a first part and a second part of a tank according to any of the preceding features, the tank comprising a support structure surrounding the storage structure, the method comprising a first step in which a secondary insulation barrier is mounted against the support structure.

[0029] According to one feature of the invention, the method for assembling a joint zone in a tank comprises a second step in which the second section of the first closing member is fixed in the thickness of the secondary insulating barrier by fixing means.

[0030] According to one feature of the invention, the secondary insulation barrier comprises a fixing plate, and the method comprises a third step in which the first section of the first closing member is fixed to the secondary insulation barrier at the fixing plate by means of a weld.

[0031] According to one feature of the invention, the supporting structure comprises an insert and the method comprises a fourth step in which the second section of the second closing member is fixed to the second section of the first closing member by a weld and the first section of the second closing member is fixed to the insert of the supporting structure by another weld.

[0032] According to one feature of the invention, the method for assembling a joint area in a tank comprises a fifth step in which a secondary sealing membrane is mounted against the secondary insulating barrier.

[0033] The fifth step of the method for assembling a joining area in a tank may be performed before or after the fourth step of the method.

[0034] According to a feature of the invention, the method for assembling a joint area in a tank includes a sixth step, in which a primary insulation barrier is assembled against a secondary space, a section of the primary insulation barrier partially covers a first section of a first closing member, and an insulation wall is assembled against a support structure at least in a main extension plane of the secondary space, a section of the insulation wall is arranged along the thickness corresponding to the first section of the second closing member.

[0035] According to one feature of the invention, the method for assembling a joint area in a tank comprises a seventh step in which a primary sealing membrane and an impermeable membrane are mounted against the primary insulating barrier and the insulating wall, respectively, the primary sealing membrane and the impermeable membrane extending in a common plane.

[0036] Finally, as a fourth subject, the present invention relates to a method for loading or unloading a liquefied gas contained in a tank according to any of the preceding features, wherein the cold liquid product is transferred via an insulated pipeline from a floating or onshore storage facility to the tank according to any of the preceding features, or from a tank according to any of the preceding features to a floating or onshore storage facility. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Other characteristics, details and advantages of the invention will become more apparent on reading the following description, as well as a number of exemplary embodiments provided by way of non-limiting indication, with reference to the accompanying schematic drawings, in which:

[0038] Figure 1 is a perspective view of a tank according to the present invention;

[0039] Figure 2 is based on Figure 1 A cross-sectional view of a tank;

[0040] Figure 3 It is arranged according to Figure 1 a cross-sectional view of the closure device between the first portion and the second portion of the top wall of the can;

[0041] Figure 4 Based on observation from the inside of the tank Figure 3 A perspective view of a closure device. DETAILED DESCRIPTION

[0042] The various features, variants and different embodiments of the present invention can be combined with each other in various combinations, as long as they are not mutually incompatible or mutually exclusive. In particular, if a selection of features described separately from other features described is sufficient to provide technical advantages and / or distinguish the present invention from the prior art, it is conceivable that the variant of the present invention includes only the selection of features.

[0043] In the following description, the terms "longitudinal," "transverse," and "vertical" refer to the orientation of the sealed, thermally insulated tank according to the present invention. The longitudinal direction corresponds to the main extension direction of the sealed, thermally insulated tank, which is parallel to the longitudinal axis L of the coordinate system L, V, T shown in the figures. The transverse direction corresponds to the direction parallel to the transverse axis along which the end wall of the sealed, thermally insulated tank mainly extends, which is parallel to the transverse axis T of the coordinate system L, V, T and perpendicular to the longitudinal axis L. Finally, the vertical direction corresponds to the direction parallel to the vertical axis V of the coordinate system L, V, T, which is perpendicular to both the longitudinal axis L and the transverse axis T.

[0044] Figure 1 A sealed, thermally insulated tank 1 is shown which is generally parallelepiped-shaped. The tank 1 comprises a storage structure 2 and a support structure 4 surrounding the storage structure 2, the storage structure 2 comprising a plurality of layers.

[0045] The storage structure 2 is configured to contain and / or store a fluid, more specifically a cryogenic liquid such as liquefied natural gas or liquefied petroleum gas. The storage structure 2 includes a plurality of walls resting against a support structure 4. The support structure 4 is configured to support the plurality of walls when the tank 1 is at least partially filled with the fluid, the fluid exerting a pressure on each of the plurality of walls, which is absorbed by the support structure 4.

[0046] By way of non-limiting example, this type of tank 1 is used for onshore storage of liquefied natural gas (LNG), to hold LNG and / or as a loading and / or unloading point for marine transport vessels (e.g., a gravity platform). A "gravity platform" refers to a tank that is at least partially submerged, for example, in a harbor, and in which a liquefaction and / or vaporization unit is partially or completely mounted on top of the tank. More specifically, the tank 1 can interact with the liquefaction and / or vaporization unit so that the tank stores liquefied gas from the liquefaction unit and / or supplies liquefied gas to the vaporization unit. The support structure 4 can comprise at least concrete.

[0047] Furthermore, the tank 1 can also be used as a tank 1 for transporting liquefied natural gas, or even as a fuel tank for ships and / or barges. Finally, the tank 1 can also be used for marine transport as a tank 1 for transporting liquefied natural gas. In this case, the support structure 4 comprises at least one hull of a floating structure, for example a metal hull.

[0048] like Figure 1 As shown, the tank 1 extends primarily in a longitudinal direction L. The plurality of walls of the storage structure 2 include a top wall 6 and a bottom wall 8, each of which extends generally in a plane parallel to the longitudinal direction L and the transverse direction T. The storage structure 2 further includes a plurality of side walls 10a, 10b extending in a vertical direction V at least between the bottom wall 8 and the top wall 6. In this case, the plurality of side walls 10a, 10b include two longitudinal walls 10a parallel to each other and two end walls 10b parallel to each other. The longitudinal wall 10a extends in the longitudinal direction L, and the end wall 10b extends in the transverse direction T between the two longitudinal walls 10a.

[0049] The support structure 4 takes the shape of the storage structure 2, surrounding the latter. To this end, the support structure 4 comprises a plurality of partitions 12, each partition 12 advantageously extending parallel to one of the walls.

[0050] In order to facilitate the understanding of the present invention, the two end walls 10b of the storage structure 2 and the partitions of the support structure 4 adjacent to the end walls are not shown in FIG. Figure 1 Shown in.

[0051] like Figure 1 As shown, the top wall 6 includes two independent spaces, a first portion 46 of which includes at least two spaces sealed relative to each other, and a second portion 48 includes at least a sealing insulation layer 50, which is in contact with the support structure 4 and helps to define the internal volume 45 of the tank 1.

[0052] The storage tank 1, more specifically the storage structure 2, is configured to maintain the liquefied natural gas at a temperature below -163°C. To this end, Figure 2As shown, each wall of the storage structure 2, together with the first portion 46 of the top wall 6, comprises, in the thickness direction from the outside to the inside of the tank 1, a secondary space 28 and a primary space 30, which are thermally insulated and sealed from each other.

[0053] According to the present invention, Figure 2 As shown, the storage structure 2 comprises closing means 58 connected to at least one of the portions 46, 48 by fastening means 84 arranged in the thickness of the storage structure 2. More specifically, the fastening means 84 are arranged in the secondary space 28 of the first portion 46.

[0054] Reference Figure 2 After describing the various components of each of the primary space 30 and the secondary space 28 and the components of the sealing insulation layer 50, a more detailed description of the closing device 58 and the fixing device 84 will be provided. Figure 2 It is along Figure 1 A plane P is shown through the section of the tank 1 .

[0055] More specifically, the secondary space 28 in the first portion 46 of the top wall includes, in sequence from the support structure 4 toward the primary space 30, a secondary insulation barrier 32 and a secondary sealing membrane 34, and the primary space 30 itself includes, in sequence from the secondary space 28 toward the interior of the tank 1, a primary insulation barrier 36 and a primary sealing membrane 38.

[0056] The secondary insulation barrier 32 is a juxtaposition of insulating self-supporting panels, each comprising, in order from the supporting structure 4 to the secondary sealing membrane 34, a first plywood sheet, an insulating block and a second plywood sheet. The insulating blocks extend between the plywood sheets and may be made of a synthetic porous material, such as polyurethane foam, allowing for effective and uniform insulation.

[0057] The secondary insulation barrier 32, more specifically a second plywood board, is fixed to the secondary sealing membrane 34, for example by gluing.

[0058] The secondary sealing film 34 includes a rigid secondary sealing film 40 and a flexible secondary sealing film 42. Figure 3 and 4 You can see it more specifically in .

[0059] like Figure 2 As shown, the primary insulation barrier 36 comprises the same components as the secondary insulation barrier 32, stacked in a similar manner. Thus, there is an insulation block in the thickness direction, flanked by two plywood panels. For the composition and function of each of these elements, reference is made to the previous description.

[0060] During the assembly of the sealed and insulated tank 1, the walls of the storage structure 2 are assembled by juxtaposition of self-supporting panels. These assembled panels are then covered with a primary sealing membrane 38, which can be made of corrugated stainless steel. Note that, alternatively, the primary sealing membrane can be made of, for example, Made of steel plate.

[0061] The primary sealing membrane 38 is intended to be in contact with the fluid contained in the tank 1 , while helping to define the interior volume 45 of the tank 1 .

[0062] The second portion 48 comprises, in thickness direction from the support structure 4 towards the internal volume 45 of the tank 1 , an insulating wall 52 resting against the support structure 4 and an impermeable membrane 54 resting on the insulating wall 52 and intended to be in contact with the fluid contained in the tank 1 .

[0063] The insulating wall 52 has the same composition as the primary and secondary insulating barriers 32 and 36 of the primary and secondary spaces 28 and 30 and therefore comprises at least one insulating block extending between two plywood panels, one of which is fixed to the supporting structure 4 by, for example, gluing.

[0064] The thickness of the insulating wall 52 of the sealing insulation layer 50 is at least equal to the sum of the thickness of the primary insulation barrier 36 and the thickness of the secondary space 28 measured in the first portion 46. The thickness of the insulating wall 52 is measured along an axis perpendicular to the plane in which the second portion 48 primarily extends, and the thickness of the primary insulation barrier 36 and the thickness of the secondary space 28 are measured along a direction perpendicular to the plane in which the first portion 46 primarily extends. In other words, the thickness of the insulating wall 52 is the sum of the thicknesses of the secondary insulation barrier 32, the secondary sealing membrane 34, and the primary insulation barrier 36.

[0065] Furthermore, according to the example shown here, the insulating wall 52 of the sealing insulating layer 50 is in airtight communication with the primary insulating barrier 36 of the primary space 30. Specifically, the inert fluid circulates in the primary insulating barrier 36 of the primary space 30 and can also pass through the insulating wall 52 of the sealing insulating layer 50.

[0066] The impermeable membrane 54 is fixed to the insulating wall 52 and is of the same composition as the primary sealing membrane 38, that is, corrugated stainless steel or The impermeable membrane 54 is welded at least at one end thereof to the primary sealing membrane 38 , ensuring the continuity of the top wall 6 between the first portion 46 and the second portion 48 .

[0067] according to Figure 2 In the example shown, the impermeable membrane 54 of the sealing insulation layer 50 and the primary sealing membrane 38 of the primary space 30 extend at least partially in a common plane, the impermeable membrane 54 extending the primary sealing membrane 38 of the primary space 30 onto the sealing insulation layer 50 in the second portion 48 .

[0068] according to Figure 2 In the example shown, the storage structure further comprises at least one closing device 58 for the secondary space 28, which is arranged at at least one junction between the first portion 46 and the second portion 48 of the top wall 6. Figure 3 and 4 The closure device 58 is described.

[0069] Now refer to Figure 1 and 2 The shape of the top wall 6 of the support structure 2 is described.

[0070] The top wall 6 includes at least four distinct face portions 14, 16, 18, 20, each of which extends in a plane secant to the plane in which the other face portions 14, 16, 18, 20 lie. The four face portions 14, 16, 18, 20 of the top wall 6 are symmetrical in pairs, forming two central face portions 14, 16 and two outer face portions 18, 20. The storage structure 2 includes a plane of symmetry that passes through the apex 26 of the can and extends in longitudinal and vertical planes, with one central face portion and one outer face portion being symmetrical to another central face portion and another outer face portion.

[0071] exist Figure 2 In the example shown, the second portion 48 of the top wall 6 is formed in at least one of the central faces 14, 16 of the top wall 6. However, a second portion 48 extending only over one of the central faces 14, 16 or only over one of the outer faces 18, 20 would not depart from the scope of the invention.

[0072] According to the example shown here, the tank 1 comprises a duct 56 passing through the support structure 4 and the storage structure 2 at least in the second portion 48 of the top wall 6 at the vertex 26 of the central faces 14 , 16 .

[0073] Now refer to Figure 3 and Figure 4 Describing in more detail the closing means 58 for the secondary space 28 provided at at least one junction between the first portion 46 and the second portion 48 of the top wall, Figure 3 yes Figure 2 A detailed view of the junction area U between the first portion 46 and the second portion 48 is shown.

[0074] like Figure 3 As shown, the closure device 58 includes a first closure member 60 and at least one second closure member 62 that are configured to interact with each other to separate the secondary space 28 of the first portion 46 from the second portion 48 .

[0075] According to an alternative embodiment, the first closure member 60 and / or the second closure member 62 include at least one fixing plate 68 for fixing to the secondary space 28. Note that the first closure member 60 and / or the second closure member 62 can be formed in one piece with the fixing plate 68 before being mounted on the secondary space 28.

[0076] like Figure 3 and Figure 4 As shown, each closure member 60, 62 is formed in a cross section of the top wall, for example along Figure 2 Each closure member 60, 62 comprises a first section 64 and at least one second section 66 extending in a secant plane.

[0077] from Figure 4 As can be seen more specifically in FIG, each closing member 60, 62 is a bent metal sheet comprising a first section 64 and a second section 66, each sheet extending at least in the longitudinal direction L of the tank 1. More specifically, the closing device 58 consists of successive sheets placed one after another to form a closing strip for the secondary space 28. Furthermore, the sheets extend around the periphery of the second portion 48, that is to say over the entire periphery of the second portion 48, and may therefore extend mainly in the longitudinal direction L or in the transverse direction T.

[0078] The interaction of each section 64 , 66 of each closure member 60 , 62 with certain components of the tank 1 will now be described.

[0079] like Figure 3 As shown, in this case, the first section 64 of the first closing member 60 extends at least partially between the secondary space 28 and the primary space 30 of the first portion 46. The secondary thermal insulation barrier 32 has an area for fixing the first section 64 of the first closing member 60. In particular, the secondary space 28 includes a fixing plate 68 to which the first section 64 of the first closing member 60 is fixed, which fixing plate 68 is located in extension of the secondary sealing membrane 34.

[0080] According to an alternative embodiment of the present invention, the fixing plate 68 and the first closing member 60 form a single-piece element, that is, the separation of one of the two elements will result in the destruction of one and / or both elements. Note that in this configuration, the first section 64 of the first closing member 60 is in direct contact with the secondary space 28 or is even directly fixed to the secondary space 28.

[0081] More specifically, if Figure 3 and 4As shown, in this case, the fixing plate 68 extends the rigid secondary sealing membrane 40, and the flexible secondary sealing membrane 42 at least partially covers the fixing plate 68 to ensure a seal between the fixing plate 68 and the rigid secondary sealing membrane 40. The fixing plate 68 is fixed to the secondary insulation barrier 32 by retaining members 70 (for example, screws or rivets). The first section 64 of the closure member is fixed to the fixing plate 68, for example, by a weld, so that the first section 64 of the first closure member 60 is arranged at least between the fixing plate 68 and the primary space 30.

[0082] Preferably, and according to an alternative embodiment, the rigid secondary sealing membrane 40 and the flexible secondary sealing membrane 42 at least partially cover the fixing plate 68 to ensure a seal between the fixing plate 68 and the secondary sealing membrane 34. In this alternative, the rigid secondary sealing membrane 40 is partially bonded to the fixing plate 68, and the flexible secondary sealing membrane 42 at least partially covers the fixing plate 68 and the rigid secondary sealing membrane 40.

[0083] like Figure 3 As shown, the secondary insulation barrier 32 comprises at least one insulating self-supporting panel 71 having an outer face 72 fixed to the support structure 4 by means of fixing elements 74 (e.g. adhesive), an inner face 76 to which the fixing plate 68 of the secondary space 28 is fixed, and a thickness face 78 extending between the outer face 72 and the inner face 76 and facing the second portion 48 of the top wall. Furthermore, each face 72, 76, 78 of the self-supporting panel 71 comprises a plywood sheet 81. The retaining member 70 and / or the fixing device 84 are fixed to or in these plywood sheets, in particular by screwing or riveting.

[0084] The self-supporting panel 71 has an inclined surface 80 connecting the inner face 76 to the thickness face 78 of the secondary insulation barrier 32. The first closure member 60 includes a curved section 82 connecting the first section 64 to the second section 66 of the first closure member 60, the curved section 82 of the first closure member 60 being arranged to correspond to, that is, opposite, the inclined surface 80 on the self-supporting panel 71.

[0085] Furthermore, in this case, each closure member 60, 62 comprises a curved section 82 connecting the first section 64 of each closure member 60, 62 to the corresponding second section 66. Due to this curved section 82, at least the first closure member 60 and the second closure member 62 of the closure device 58 are elastically deformable. For example, due to the movement of surges or due to sudden changes in temperature, in particular during the loading or unloading phase of the tank according to the present invention, the various components of the top wall may shrink and / or expand. The first closure member 60 and the second closure member 62 of the closure device 58 are configured to adapt their shape to the movement of the components of the top wall. More specifically, under the effect of the above-mentioned stresses, each section 64, 66 of each closure member 60, 62 can move away from and towards each other.

[0086] According to the invention, at least one of the sections 64, 66 of one and / or the other of the closing members 60, 62 is connected to at least one of the portions 46, 48 by means of fixing means 84 arranged in the thickness of the storage structure 2. In other words, at least one of the sections 64, 66 of one and / or the other of the closing members 60, 62 is in contact with one of the portions 46, 48 and is fixed to this portion by the fixing means 84, at least one of the sections 64, 66 of one or the other of the closing members extending in a direction perpendicular to the main extension plane of the portions 46, 48.

[0087] like Figure 3 As shown, the first closure member 60 is positioned against the secondary insulation barrier 32 such that the second section 66 of the first closure member 60 extends along the thickness face 78 of the secondary insulation barrier 32. The second section 66 of the first closure member 60 is rigidly secured to the secondary insulation barrier 32 on the thickness face 78 by a fixing device 84 extending at least partially through the plywood 81 of the thickness face 78. The fixing device 84 may be, for example, a screw or a rivet. Advantageously, the fixing device 84 is a wood screw.

[0088] As will be understood from the above, the fixing means 84 is mounted at the end portion of the secondary insulation barrier 32. In other words, the fixing means 84 extends through the thickness face 78 of the self-supporting panel 71, which extends between the exterior face 72 and the interior face 76 of said self-supporting panel, to fix the first closure member 60 to the self-supporting panel 71.

[0089] according to Figure 3In the example shown, the second segment 66 of each closure member 60, 62 extends in a plane perpendicular to the plane in which the first segments 64 of the first and second closure members 60, 62 extend. Thus, the second segment 66 of the first closure member 60 extends from the curved section 82 of the first closure member 60 toward the support structure 4, and the second segment 66 of the second closure member 62 extends from the curved section 82 of the second closure member 62 toward the interior volume of the tank. The second segment 66 of each closure member 60, 62 includes an end 86, and the second segment 66 of each closure member 60, 62 contacts the second segment 66 of the other closure member 60, 62 at least over an area extending between the end 86 of the second segment 66 of the first closure member 60 and the end 86 of the second segment 66 of the second closure member 62.

[0090] Note that in this case, the second section 66 of the first closure member 60 is flanked on one side by the plywood 81 of the thickness face 78 and on the other side by the second section 66 of the second closure member 62. Each closure member 60, 62 is secured to the other closure member 60, 62 by at least one weld. More specifically, the second section 66 of the second closure member 62 is secured to the second section 66 of the first closure member 60 by, for example, at least one weld formed on the second section 66 of the second closure member 62 along an end 86 of the second section 66 of the first closure member 60.

[0091] In an alternative embodiment to the above-described embodiment, the second section 66 of the second closing element 62 is fixed to the plywood 81 of the thickness face by means of fixing means 84, and the second section 66 of the first closing element 60 is itself fixed to the second section 66 of the second closing element 62. Thus, the second section 66 of the second closing element 62 is flanked on the one hand by the plywood 81 of the thickness face 78 and on the other hand by the second section 66 of the first closing element 60.

[0092] like Figure 3 As shown, the first section 64 of the second closure member 62 extends at least partially between the sealing insulation layer 50 of the second portion 48 and the support structure 4. The first section 64 of the second closure member 62 is fixed to the support structure 4. To this end, the support structure 4 includes Figure 4 Also visible in FIG. 8 is the insert 88 , against which the first section 64 of the second closure member 62 is secured.

[0093] According to one example of the invention, the insert 88 of the support structure is metallic and the first section 64 of the second closing member 62 is fixed to the insert 88 of the support structure 4 by at least one weld.

[0094] according to Figure 3In the example shown, the second sections 66 of the closure members 60, 62, a section of the insulating wall 52, and a section of the primary insulating barrier 36 help define a cavity 90 that is filled with an insulating composition, such as glass wool.

[0095] The present invention also relates to a method for assembling a joint region U of a tank 1, comprising at least seven steps performed one after the other in chronological order. However, other assembly steps not listed may be interspersed between these seven steps. The assembly method comprises a first step in which the secondary insulation barrier 32 is assembled against the support structure 4 of the tank 1. To this end, at least one self-supporting panel 71 is preassembled. The self-supporting panel 71 consists essentially of an insulation block flanked by two plywood sheets. The self-supporting panel 71 is bonded to the support structure 4, for example, using an adhesive.

[0096] The method for assembling the joining area U comprises a second step in which the first section 64 of the first closing member 60 is fitted against the fixing plate 68 of the secondary thermal insulation barrier 32, the fixing plate 68 being positioned on the inner face 76 of the self-supporting panel 71, and the second section 66 of the first closing member 60 is fitted against the thickness face 78 of the self-supporting panel 71 forming the secondary thermal insulation barrier 32. The second section 66 of the first closing member 60 is then fixed to the thickness face 78 of the self-supporting panel 71 of the secondary thermal insulation barrier 32 by fixing means 84.

[0097] The method for assembling the joining area U comprises a third step in which the first section 64 of the first closing member 60 is fixed to the fixing plate 68 of the secondary thermal insulation barrier 32 , for example by means of a weld.

[0098] The method for assembling the joining region U includes a fourth step in which the first section 64 of the second closure member 62 is mounted against the support structure 4 and the second section 66 of the second closure member 62 is mounted against the second section 66 of the first closure member 60. The second section 66 of the second closure member 62 is then fixed to the second section 66 of the first closure member 60, for example, by a weld. The first section 64 of the second closure member 62 is fixed to the insert 88 of the support structure 4, for example, by another weld. These last two sub-steps can be performed one after the other.

[0099] The method for assembling the joint area U includes the step of assembling the secondary sealing membrane 34 against the secondary insulation barrier 32. This step can be performed between the first step and any other steps of the method. More specifically, the rigid secondary sealing membrane 40 is bonded against the secondary insulation barrier 32 so that the rigid secondary sealing membrane 40 and the fixing plate 68 of the secondary insulation barrier 32 are coplanar. Then, the flexible secondary sealing membrane 42 is bonded against the rigid secondary sealing membrane 40 and at least partially against the fixing plate 68 of the secondary insulation barrier 32, thereby covering the joint between the secondary sealing membrane 34 and the fixing plate 68.

[0100] The method for assembling the joining area U comprises a sixth step, in which the primary thermally insulating barrier 36 is fitted against the secondary space 28, a section of the primary thermally insulating barrier 36 partially covering the first section 64 of the first closing member 60. Next, the thermally insulating wall 52 is fitted against the storage structure 2 at least in the same main extension plane as that of the first portion 46, a section of the thermally insulating wall 52 partially covering the first section 64 of the second closing member 62.

[0101] The method for assembling the joint region U includes a seventh step, in which the primary sealing membrane 38 and the impermeable membrane 54 are respectively assembled against the primary thermal insulation barrier 36 and the insulating wall 52. The primary sealing membrane 38 and the impermeable membrane 54 cover the joint between the primary thermal insulation barrier 36 and the insulating wall 52. The primary thermal insulation barrier 36 and the insulating wall 52 are interconnected, forming a common volume through which an inert fluid, such as nitrogen molecules, can pass. Thus, the sealing membrane 38 and the impermeable membrane 54 seal this common volume, as well as the first portion 46 and the second portion 48, from the fluid circulating and / or stored in the interior volume 45 of the tank 1.

[0102] The invention also relates to a method for loading or unloading liquefied gas contained in a tank as described above, wherein the cold liquid product is transferred from a floating or onshore storage facility to the tank 1 or from the tank 1 to a floating or onshore storage facility via an insulated pipeline.

[0103] However, the present invention is not limited to the devices and configurations described and illustrated herein, but rather extends to any equivalent devices and configurations, as well as any combination of their technical functions. In particular, the second portion and the closure device, which in this case are located on the central face of the top wall, could, in another embodiment, be installed on at least one other face of the storage structure, or even on another wall. Furthermore, the orientation of each element could vary depending on the position of the second portion within the tank.

Claims

1. A sealed and insulated tank (1) for transporting and / or storing liquefied natural gas, comprising at least one supporting structure (4) and a storage structure (2) surrounded by the supporting structure (4), the storage structure (2) comprising at least a first portion (46) and a second portion (48) sealed relative to each other, the first portion (46) and the second portion (48) extending at least partially in the same plane parallel to the supporting structure (4), the storage structure (2) having a thickness from the outside toward the inside of the tank (1) in a direction perpendicular to the plane of the supporting structure (4), the tank (1) comprising a closing device (58) at least partially arranged in the thickness of the storage structure (2), the closing device (58) ) comprises at least a first closing member (60) and a second closing member (62), the first closing member and the second closing member being configured to interact with each other to separate the first portion (46) from the second portion (48), at least one of the first closing member (60) and the second closing member (62) comprising a first segment (64) and a second segment (66) extending in a secant plane, at least one of the first segment (64) and the second segment (66) of one and / or the other of the first closing member (60) and the second closing member (62) being connected to at least one of the first portion (46) and the second portion (48) by a fixing device (84) arranged in the thickness of the storage structure (2), characterized in that The first closure member (60) and the second closure member (62) have an "L" shaped profile in a cross section through the closure device (58).

2. The tank (1) according to claim 1, wherein At least one of the first closure member (60) and the second closure member (62) is secured to the other of the first closure member (60) and the second closure member (62) by at least one weld.

3. Tank (1) according to any one of the preceding claims, wherein The first closure member (60) and / or the second closure member (62) of the closure device (58) are elastically deformable.

4. Tank (1) according to any one of the preceding claims, wherein One of the first closing member (60) and the second closing member (62) is connected to at least one of the first portion (46) and the second portion (48) by means of fixing means (84) arranged in the thickness of the storage structure (2), and the other of the first closing member (60) and the second closing member (62) is connected to the support structure (4).

5. The tank (1) according to claim 4, wherein The first portion (46) includes a secondary space (28) and a primary space (30), wherein the secondary space (28) includes, in sequence from the outside to the inside of the tank (1) in the thickness direction, a secondary insulation barrier (32) suitable for contacting the support structure (4) and a secondary sealing membrane (34) resting on the secondary insulation barrier (32), and the fixing device (84) at least partially extends into the secondary insulation barrier (32), and the primary space (30) includes, in sequence from the outside to the inside of the thickness direction of the tank (1), a primary insulation barrier (36) resting on the secondary sealing membrane (34) and a primary sealing membrane (38) resting on the primary insulation barrier (36) and used for contacting the fluid contained in the tank (1), and the second portion (48) includes an insulation wall (52) suitable for contacting the support structure (4) and an impermeable membrane (54) resting on the insulation wall (52) and used for contacting the fluid contained in the tank (1).

6. The tank (1) according to claim 5, wherein The secondary space (28) comprises a fixing plate (68) arranged between the secondary insulation barrier (32) and the primary space (30), a first section (64) of the first closing member (60) being connected to the fixing plate (68) by at least one weld, and a second section (66) of the first closing member (60) being connected to the secondary insulation barrier (32) by the fixing means (84) arranged in the thickness of the storage structure (2).

7. The tank (1) according to claim 5, wherein The support structure (4) comprises an insert (88), to which a first section (64) of the second closing member (62) is connected by at least one weld, and a second section (66) of the second closing member (62) is connected to the secondary insulation barrier (32) by means of fixing means (84) arranged in the thickness of the storage structure (2).

8. The tank (1) according to claim 6, wherein At least the secondary space (28) includes at least one insulating self-supporting panel (71), the self-supporting panel having an inner face (76) oriented toward the interior of the tank (1), an outer face (72) positioned toward the exterior of the tank (1), and a thickness face (78) extending between the inner face (76) and the outer face (72) of the self-supporting panel (71), the self-supporting panel (71) of the secondary space (28) adjacent to the first closure member (60) including an inclined face (80) connecting the inner face (76) and the thickness face (78) of the self-supporting panel (71).

9. The tank (1) according to claim 8, wherein The thickness face (78) of the self-supporting panel (71) comprises a plywood panel (81) which receives the fixing means (84).

10. Tank (1) according to claim 8 or 9, wherein The first closing member (60) includes a curved section (82) connecting the first section (64) of the first closing member (60) to the second section (66), and the first closing member (60) is positioned against the inner surface (76) and the thickness surface (78) of the self-supporting panel (71) of the secondary space (28) so that the curved section (82) of the first closing member (60) is arranged corresponding to the inclined surface (80) on the self-supporting panel (71).

11. A transport and / or storage unit comprising at least one tank (1) according to any one of claims 1 to 10, the transport and / or storage unit comprising a ship, a barge, a reliquefaction unit, a gasification unit, an onshore structure or a gravity platform.

12. A method for assembling a joint area (U) between a first part (46) of a tank (1) according to claim 5 and a second part (48) of a tank (1) according to any one of claims 1 to 10, the tank (1) comprising a support structure (4) surrounding the storage structure (2), the method comprising a first step in which the secondary insulation barrier (32) is assembled against the support structure (4).

13. Method for assembling a joining area (U) according to claim 12, comprising a second step, wherein The second section (66) of the first closing member (60) or the second closing member (62) is fixed in the thickness of the secondary thermal insulation barrier (32) by means of fixing means (84).

14. A method for assembling a joint area (U) according to claim 13, wherein the secondary insulation barrier (32) includes a fixing plate (68), the method comprising a third step in which the first section (64) of the first closing member (60) is fixed to the secondary insulation barrier (32) at the fixing plate (68) by means of a weld.

15. A method for assembling a joining area (U) according to claim 14, wherein the support structure (4) includes an insert (88), and the method includes a fourth step, in which the second segment (66) of the second closing member (62) is fixed to the second segment (66) of the first closing member (60) by a weld, and the first segment (64) of the second closing member (62) is fixed to the insert (88) of the support structure (4) by another weld.

16. Method for assembling a joining area (U) according to claim 15, comprising a fifth step, wherein The secondary sealing membrane (34) is fitted against the secondary thermal insulation barrier (32).

17. Method for assembling a joining area (U) according to claim 16, comprising a sixth step, wherein The primary thermal insulation barrier (36) is mounted against the secondary space (28), a section of the primary thermal insulation barrier (36) partially covering the first section (64) of the first closing member (60), and the thermal insulation wall (52) is mounted against the support structure (4) at least in the main extension plane of the secondary space (28), a section of the thermal insulation wall (52) is arranged corresponding to the first section (64) of the second closing member (62) along the thickness.

18. The method of assembling a joining area (U) according to claim 17, comprising a seventh step, in which the primary sealing membrane (38) and the impermeable membrane (54) are fitted against the primary insulating barrier (36) and the insulating wall (52), respectively, the primary sealing membrane (38) and the impermeable membrane (54) extending in a common plane.

19. A method for loading or unloading liquefied gas contained in a tank (1) according to any one of claims 1 to 10, wherein: The cold liquid product is transferred from a floating or onshore storage facility to a tank (1) according to any one of claims 1 to 10 or from the tank to the floating or onshore storage facility via an insulated pipeline.

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