SEALED AND THERMALLY INSULATED TANK
Patent Information
- Authority / Receiving Office
- MX · MX
- Patent Type
- Patents
- Current Assignee / Owner
- GAZTRANSPORT & TECHNIGAZ SA
- Filing Date
- 2023-01-13
- Publication Date
- 2026-06-12
AI Technical Summary
Existing onshore liquefied natural gas storage tanks face challenges with complex and precision-demanding closure devices that create gaps, leading to thermal bridges, which are difficult to install and maintain, especially in large steel or concrete tanks.
A closure device for onshore liquefied natural gas storage tanks that adapts to the assembly position of the secondary space, comprising L-shaped closure members with securing devices, allowing for precise alignment and sealing between the first and second portions of the tank walls, ensuring thermal insulation and fluid integrity.
The solution provides a simplified and effective sealing mechanism that reduces thermal bridges, enhances thermal insulation, and maintains fluid integrity by adapting to structural movements, thus improving the efficiency and reliability of LNG storage.
Smart Images
Figure MX435140B0
Abstract
Description
SEALED AND THERMALLY INSULATED TANK ML / a / ZUZ Ó / UUU l ¿u FIELD OF INVENTION The present invention relates to the field of liquefied natural gas storage tanks, in particular onshore liquefied natural gas storage tanks. BACKGROUND OF THE INVENTION Liquefied natural gas (LNG) is generally transported by sea in storage tanks fitted to carrier ships. The natural gas is kept in liquid form to increase the amount transported per tank, as the volume of one liter of liquid natural gas is much smaller than the volume of one liter of gaseous natural gas. These tanks maintain the LNG at a very low temperature, specifically below -163°C, the temperature at which natural gas is liquid at atmospheric pressure. To load and / or unload the tanks of these liquefied natural gas (LNG) carriers, an onshore LNG storage tank is installed at a port. This is generally done so that LNG carriers can come in and refuel and / or unload their LNG cargo. These onshore storage tanks are equipped with components that pass through one of their walls, such as a pipe, thus allowing communication between an LNG loading and / or unloading facility and an internal volume of the onshore tank where the LNG is stored and / or unloaded. As is known, these onshore tanks include a proposed storage structure for containing liquefied natural gas and a support structure surrounding the storage structure. The walls of the storage structure generally include at least a sealed, thermally insulated secondary space and a sealed, thermally insulated primary space resting on the secondary space and configured to be in contact with the liquefied natural gas contained in the tank. In some cases, the storage structure may comprise a wall having a first portion consisting of at least the secondary and primary spaces and a second portion comprising a sealed, thermally insulating layer in contact, on one side, with the support structure and, on the other side, with the liquefied natural gas.This type of accessory can be placed to facilitate the passage of a through element through the wall, and more precisely in the sealed and thermally insulating layer. At the junction between the first and second sections, a device is generally installed to seal the secondary space of the first section and the secondary space of the second section. However, these sealing devices are generally complex to install and / or require considerable precision when assembling the tank's storage structure walls. Since this precision is often difficult to achieve for large steel or concrete tanks, a gap exists between the sealing device and the secondary space components, which must be filled to minimize thermal bridging. BRIEF DESCRIPTION OF THE INVENTION In this context, the present invention proposes an alternative to existing solutions by virtue of a locking device that adapts to the position of the secondary space during the assembly of the storage structure wall. For this purpose, the main subject matter of the present invention is a sealed and thermally insulated tank for the transport and / or storage of liquefied natural gas, comprising at least a support structure and a storage structure surrounded by the support structure, the storage structure comprising at least a first portion and a second portion that seal against each other, the first portion and the second portion extending at least partially in the same plane parallel to the support structure, the storage structure having a thickness from the outside to the inside of the tank in a direction perpendicular to the plane of the support structure, the tank comprising a closing device arranged at least partially within the thickness of the storage structure,The closing device comprises at least a first closing member and a second closing member configured to interact with each other such that the first portion is separated from the second portion, at least one of the closing members comprising a first and a second part extending in intersecting planes, characterized in that at least one of the parts of one and / or the other of the closing members is connected to at least one of the parts by a securing device arranged within the thickness of the storage structure. The tank storage structure comprises a plurality of walls, each of which comprises at least a first portion and a second portion. According to the invention, one of the walls of the plurality of walls comprises a part in which the first and second portions extend in the same plane parallel to the support structure. It should be noted in this case that the first and second portions are aligned with each other, while their internal volumes remain independent, since the first portion is sealed with respect to the second portion. The term “thickness” means the dimension of the element in question measured in a direction perpendicular to the supporting structure of the first and second portions; the thickness possibly being that which is part of one or the other of the portions lying in this direction. Furthermore, at least one of the parts of one and / or the other of the members of ML / a / ZUZ Ó / UUU l zu closure extends into the thickness, in an area located between the first portion and the second portion, the securing device that is secured to at least one of the portions in its thickness. According to an optional feature of the invention, at least one of the closing members has an L-shaped profile seen in a section plane passing through the closing device. According to an optional feature of the invention, the first closing member and the second closing member have an L-shaped profile as seen in a section plane passing through the closing device. According to another optional feature of the invention, the first part of one of the closing members extends perpendicularly with respect to the second part of this closing member. According to another optional feature of the invention, at least one of the closing members is secured to the other closing member by at least one weld bead. The weld bead also ensures a seal between these two closing members, such that any fluid exchange between the first and second portions is prevented. According to another optional feature of the invention, the second part of one of the closing members is secured to the second part of the other closing member by a weld bead. According to another feature of the invention, the first closing member and the second closing member are positioned head to tail with respect to each other. According to another feature of the invention, the second part of the first closing member extends parallel to the second part of the second closing member, the second parts of the closing members join together, the other two parts of the closing members extend far apart from each other in planes parallel to each other. According to another optional feature of the invention, the first and / or second closing members of the closure device are elastically deformable. Elastically deformable means that each of the closing members can change its shape under pressure, returning to its original shape when the pressure is removed. This feature allows the first and second closing members to adapt to the expansion or contraction of the first and / or second portions. According to another feature of the invention, one of the closing members is connected to at least one of the portions by the securing device arranged in the thickness of the storage structure, the other closing member being connected to the support structure. According to another optional feature of the invention, one of the members of ML / a / ZUZ Ó / UUU l zu closure is connected to at least one of the portions by the securing device arranged in the thickness of the support structure, the support structure comprising an insert piece in which one or the other of the parts of the other closure member is secured. According to another optional feature of the invention, the first portion comprises a secondary space and a primary space, the secondary space comprising, successively in the thickness direction from the outside to the inside of the tank, a secondary thermally insulating barrier adapted to be in contact with the support structure and a secondary sealing membrane resting on the secondary thermally insulating barrier, the securing device extending at least partially into the secondary thermally insulating barrier, the primary space comprising, successively in the thickness direction from the outside to the inside of the tank, a primary thermally insulating barrier resting on the secondary sealing membrane and a primary sealing membrane resting on the primary thermally insulating barrier and proposed to be in contact with the fluid contained in the tank,the second portion comprising a thermally insulating wall adapted to be in contact with the support structure and a waterproof membrane resting on the thermally insulating wall and proposed to be in contact with the fluid contained in the tank. According to this feature, the tank comprises a portion of its wall where the primary and secondary spaces overlap, and a portion of its wall provided only with the sealed, thermally insulating layer, the secondary space, which is then closed by the closing device according to the invention. The volume of the second portion is in communication with the volume of the primary space of the first portion of the support structure, such that this common volume can be traversed by the same inertia fluid, in particular dinitrogen. According to another optional feature of the invention, the secondary space comprises a securing plate arranged between the secondary thermally insulating barrier and the primary space, the first part of the first closing member being connected to the securing plate by at least one weld bead, the second part of the first closing member being connected to the secondary thermally insulating barrier by the securing device arranged in the thickness of the storage structure. According to another optional feature of the invention, the first part of the first closing member is connected to a securing plate by at least one weld bead, the securing plate and the first closing member being configured to be mounted in one piece over the secondary thermally insulating barrier. According to another optional feature of the invention, the support structure comprises an insert piece, the first part of the second closing member which is ML / a / ZUZ Ó / UUU l ¿u connects to the insert piece by at least one weld bead, the second part of the second closing member that connects to the secondary thermally insulating barrier by the securing device fixed in the thickness of the storage structure. According to another optional feature of the invention, at least the secondary space comprises at least one thermally insulating self-supporting panel having an inner face facing the interior of the tank, an outer face facing the exterior of the tank, and a thickness face extending between the inner and outer faces of the self-supporting panel. The self-supporting panel of the secondary space adjacent to the first closing member comprises a chamfer connecting the inner 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 comprises a plywood panel that receives the securing device. According to another optional feature of the invention, the first closing member comprises a folded portion connecting the first part to the second part of the first closing member, the first closing member being placed against the inner face and the thickness face of the self-supporting panel of the secondary space such that the folded portion of the first closing member is arranged in line with the chamfer on the self-supporting panel. The present invention also relates, as a second present matter, to a transport and / or storage unit comprising at least one tank according to any of the above characteristics, the transport and / or storage unit consisting of a vessel, a barge, a reliquefaction unit, a gasification unit, an onshore structure, or a gravity platform. The present invention also relates, as a third present matter, to a method for assembling the joining zone between a first portion and a second portion of the tank according to any of the above features, the tank comprising a support structure surrounding the storage structure, the method comprising a first step in which the secondary thermally insulating barrier is fitted against the support structure. According to a feature of the invention, the method for assembling a joining zone in the tank comprises a second step in which the second part of the first closing member is secured to a thickness of the secondary thermally insulating barrier by the securing device. According to a feature of the invention, the secondary thermal insulating barrier comprises a securing plate, the method comprising a third step, in which the first part of the first closing member is secured to the secondary thermal insulating barrier on this securing plate by a weld bead. Ó / UUU l ¿u According to a feature of the invention, the support structure comprises an insert piece, the method comprises a fourth step in which the second part of the second closing member is secured to the second part of the first closing member by a weld bead, and the first part of the second closing member is secured to the insert piece of the support structure by another weld bead. According to a feature of the invention, the method for assembling a bonding zone in the tank comprises a fifth step in which the secondary sealing membrane is fitted against the secondary thermally insulating barrier. This fifth step of the method for assembling a bonding zone in a tank can take place before or after the fourth step in the method. According to a feature of the invention, the method for assembling a joining zone in the tank comprises a sixth step, in which the primary thermal insulating barrier is placed against the secondary space, part of the primary thermal insulating barrier partially covering the first part of the first closing member, and the thermal insulating wall is placed against the support structure at least in the main plane of extension of the secondary space, part of the thermal insulating wall being arranged in line with the first part of the second closing member along the thickness. According to a feature of the invention, the method for assembling a bonding zone in the tank comprises a seventh step, in which the primary sealing membrane and the waterproof membrane are fitted against the primary thermally insulating barrier and against the thermally insulating wall, respectively, the primary sealing membrane and the waterproof membrane extending in a common plane. Finally, the present invention relates, as a fourth matter, to a method for loading or unloading liquefied gas contained in a tank according to any of the above characteristics, wherein a cold liquid product is transported through insulated pipes from or to a floating or land-based storage facility, to or from a tank according to any of the above characteristics. BRIEF DESCRIPTION OF THE FIGURES Other features, details, and advantages of the invention will become more clearly evident from reading the following description and from a number of exemplary embodiments provided by way of non-limiting indication, with reference to the attached schematic figures, in which: FIGURE 1 is a perspective view of a tank according to the invention; FIGURE 2 is a cross-section through the tank according to FIGURE 1; FIGURE 3 is a cross-section through an arranged locking device ML / a / ZUZ Ó / UUU l zu between a first portion and a second portion of a tank roof wall according to FIGURE 1; FIGURE 4 is a perspective view of the closing device according to FIGURE 3, viewed from inside the tank. DETAILED DESCRIPTION OF THE INVENTION The features, variants, and different embodiments of the invention may be combined with each other in various combinations, provided they are not mutually incompatible or mutually exclusive. In particular, variants of the invention comprising only a selection of the features described below, independent of the other features described, may be considered if this selection of features is sufficient to provide a technical advantage and / or to differentiate the invention from the prior art. In the description below, the terms “longitudinal,” “transverse,” and “vertical” refer to the orientation of a sealed, thermally insulated tank according to the invention. A longitudinal direction corresponds to a principal extension direction of the sealed, thermally insulated tank, this longitudinal direction being parallel to a longitudinal axis L of an L, V, T coordinate system shown in the FIGURES. A transverse direction corresponds to a direction parallel to a transverse axis along which a terminal wall of the sealed, thermally insulated tank primarily extends, this transverse direction being parallel to a transverse axis T of an L, V, T coordinate system, and this transverse axis T being perpendicular to the longitudinal axis L.Finally, a vertical direction corresponds to a direction parallel to a vertical axis V of the L, V, T coordinate system, this vertical axis V being perpendicular to the longitudinal axis L and the transverse axis T. Figure 1 shows a sealed and thermally insulated tank 1, generally in the shape of a rectangular parallelepiped. The tank 1 comprises a storage structure 2 and a support structure 4 surrounding the storage structure 2, the storage structure 2 being composed of layers. The storage structure 2 is configured to contain and / or store a fluid, and more particularly a cryogenic liquid, such as, for example, liquefied natural gas or liquefied petroleum gas. The storage structure 2 comprises a plurality of walls resting against the support structure 4. The latter is configured to support the plurality of walls when tank 1 is at least partially filled with this fluid, this fluid exerting pressure on each of the walls of the plurality of walls, this pressure being captured by the support structure 4. According to a non-limiting example, this type of tank 1 is used in the ML / a / ZUZ Ó / UUU l zu onshore liquefied natural gas storage facility for containing liquefied natural gas and / or as a loading and / or unloading point for a seagoing vessel, such as, for example, a gravity platform. “Gravity platform” means that the tank is at least partially submerged, for example, in a port, and that a liquefaction and / or gasification unit is partially or fully installed on the roof of the tank. More specifically, tank 1 may interact with the liquefaction and / or gasification unit such that the tank stores liquefied gas coming from the liquefaction unit and / or supplies the gasification unit with liquefied gas. The support structure 4 may then comprise at least concrete. Furthermore, this tank 1 can also be used as a tank 1 for transporting liquefied natural gas, or even as a fuel tank for a ship and / or barge. Finally, this tank 1 can also be used in maritime transport, as a tank 1 for transporting liquefied natural gas. In this case, the support structure 4 comprises at least one hull of the floating structure, such as a metal hull, for example. As shown here in FIGURE 1, tank 1 extends primarily in a longitudinal direction L. The plurality of walls of the storage structure 2 comprises a roof wall 6 and a bottom wall 8, each generally extending in a plane parallel to the longitudinal direction L and a transverse direction T. The storage structure 2 also comprises a plurality of side walls 10a, 10b extending at least in a vertical direction V between the bottom wall 8 and the roof wall 6. The plurality of side walls 10a, 10b in this case comprises two longitudinal walls 10a parallel to each other and two end walls 10b parallel to each other. The longitudinal walls 10a extend in the longitudinal direction L, and the end walls 10b extend in the transverse direction T between the two longitudinal walls 10a. The support structure 4 takes the form of the storage structure 2, surrounding the latter. To this end, the support structure 4 comprises a plurality of partitions 12, each of these partitions 12 extending advantageously parallel to one of the walls of the plurality of walls. To facilitate understanding of the invention, the two end walls 10b of the storage structure 2, and the division of the support structure 4 adjacent to this end wall are not shown in FIGURE 1. As shown in FIGURE 1, the roof wall 6 comprises two separate spaces, a first portion 46 of which consists of at least two spaces that are sealed against each other, and a second portion 48 which consists of at least one sealed, thermally insulating layer 50 in contact with the support structure 4, while contributing to defining an internal volume 45 of the tank 1. Tank 1, and more particularly storage structure 2, is configured to ML / a / ZUZ Ó / UUU l zu to maintain the liquefied natural gas at a temperature below -163°C. For this purpose, and as shown in FIGURE 2, each wall of the storage structure 2, together with the first portion 46 of the roof wall 6, successively comprise in the thickness direction from the outside to the inside of the tank 1, a secondary space 28 and a primary space 30, thermally insulating and sealed from each other. According to the invention and as shown in FIGURE 2, the storage structure 2 comprises a locking device 58 connected to at least one of the portions 46,48 by a securing device 84 arranged in the thickness of the storage structure 2. More particularly, the securing device 84 is arranged in the secondary space 28 of the first portion 46. A more detailed description of the closing device 58 and the securing device 84 will be provided after the description of the various components of each of the primary 30 and secondary 28 spaces, and of the components of the sealed and thermally insulating layer 50, with reference to FIGURE 2 which is a section through tank 1 along a plane P shown in FIGURE 1. More specifically, the secondary space 28 in the first portion 46 of the roof wall comprises, successively from the support structure 4 towards the primary space 30, a secondary thermal insulating barrier 32, a secondary sealing membrane 34, the primary space 30 for its part comprising, successively from the secondary space 28 towards the interior of the tank 1, a primary thermal insulating barrier 36 and a primary sealing membrane 38. The secondary thermal insulating barrier 32 is a juxtaposition of self-supporting panels, which are thermal insulators. Each self-supporting panel comprises, successively from the support structure 4 to the secondary sealing membrane 34, a first plywood sheet, a thermal insulation block, and a second plywood sheet. The thermal insulation block is sandwiched between the plywood sheets and can be made of a synthetic honeycomb material, such as polyurethane foam, for example, allowing for efficient and homogeneous thermal insulation. The secondary thermal insulating barrier 32, and more particularly the second plywood plate, is secured to the secondary sealing membrane 34, for example, by adhesive bonding. The secondary sealing membrane 34 comprises a rigid secondary sealing membrane 40 and a flexible secondary sealing membrane 42, as can be seen more particularly in FIGURES 3 and 4. As shown in FIGURE 2, the primary thermal insulating barrier 36 has the same components as the secondary thermal insulating barrier 32, these same ML / a / ZUZ Ó / UUU l zu components that overlap in a similar manner. Therefore, there is a thermal insulation block flanked in the thickness direction by two plywood sheets. Reference can be made to the above for the composition and function of each of these elements. During the assembly of the sealed and thermally insulated tank 1, the walls of the storage structure 2 are assembled by juxtaposing the self-supporting panels. These assembly panels are then covered with the primary sealing membrane 38, which can be made of corrugated stainless steel. It should be noted that, alternatively, the primary sealing membrane can be made, for example, of InvarMR sheet. It is proposed that the primary sealing membrane 38 be in contact with the fluid contained in tank 1 as it helps to define the internal volume 45 of tank 1. The second portion 48 comprises, in the thickness direction from the support structure 4 towards the internal volume 45 of tank 1, a thermally insulating wall 52 resting against the support structure 4 and an impermeable membrane 54 resting on the thermally insulating wall 52 and proposed to be in contact with the fluid contained in tank 1. The thermally insulating wall 52 has the same composition as the primary and secondary thermal insulation barriers 32, 36 of the primary and secondary spaces 28, 30, and therefore comprises at least one thermal insulation block extending between two plywood boards, one of the boards being secured to the support structure 4, for example, by adhesive bonding. The thermally insulating wall 52 of the thermally insulating and sealed layer 50 has a thickness at least equal to the sum of the thickness of the primary thermally insulating barrier 36 and the thickness of the secondary space 28 measured in the first portion 46. The thickness of the thermally insulating wall 52 is measured along an axis perpendicular to a plane in which the second portion 48 mainly extends, while the thickness of the primary thermally insulating barrier 36 and the thickness of the secondary space 28 are measured in a direction perpendicular to a plane in which the first portion 46 mainly extends. In other words, the thickness of the thermally insulating wall 52 is the sum of the thicknesses of the secondary thermally insulating barrier 32, the secondary sealing membrane 34, and the primary thermally insulating barrier 36. Furthermore, and according to the example shown here, the thermally insulating wall 52 of the sealed and thermally insulating layer 50 is in air communication with the primary thermally insulating barrier 36 of the primary space 30. To be specific, an inertia fluid circulates in the primary thermally insulating barrier 36 of the primary space 30 and can also pass through the thermally insulating wall 52 of the sealed and J / UUU l ¿u thermally insulating 50. The waterproof membrane 54 is secured to the thermally insulating wall 52 and has the same composition as the primary sealing membrane 38, i.e., corrugated stainless steel or InvarMR sheet. The waterproof membrane 54 is welded at at least one end to the primary sealing membrane 38, ensuring the continuity of the roof wall 6 between the first portion 46 and the second portion 48. According to the example shown in FIGURE 2, the waterproof membrane 54 of the sealed and thermally insulating layer 50 and the primary sealing membrane 38 of the primary space 30 extend at least partially in a common plane, the waterproof membrane 54 extending the primary sealing membrane 38 of the primary space 30 over the sealed and thermally insulating layer 50 in the second portion 48. According to the example shown in FIGURE 2, the storage structure also comprises at least one locking device 58 for the secondary space 28 arranged at at least one joint between the first portion 46 and the second portion 48 of the ceiling wall 6. The locking device 58 is described with reference to FIGURES 3 and 4. The shape of the roof wall 6 of the support structure 2 will now be described with reference to FIGURES 1 and 2. The roof wall 6 is composed of at least four distinct facets 14, 16, 18, 20, each of these facets 14, 16, 18, 20 extending in a secant plane to the planes in which the other facets 14, 16, 18, 20 are located. The four facets 14, 16, 18, 20 of the roof wall 6 are symmetrical in pairs, forming two central facets 14, 16 and two external facets 18, 20. The storage structure 2 comprises a plane of symmetry passing through a vertex 26 of the tank and extending in a longitudinal and vertical plane, a central facet, and an external facet that is symmetrical to the other central facet and the other external facet. In the example shown in FIGURE 2, the second portion 48 of the roof wall 6 is formed on at least one of the central facets 14,16 of the roof wall 6. However, a second portion 48 that extends only over one of the central facets 14, 16 or only over one of the outer facets 18, 20 would not deviate from the scope of the invention. According to the example shown here, tank 1 comprises a tube 56 passing through at least the support structure 4 and the storage structure 2 in the second portion 48 of the roof wall 6, at the vertex 26 of the central facets 14, 16. The closing device 58 for the secondary space 28 arranged at at least one joint between the first portion 46 and the second portion 48 of the ceiling wall will now be described in more detail with reference to FIGURES 3 and 4, FIGURE 3 being a detailed view of a joint area U between the first portion 46 and the second portion 48 shown ΜΛ / a / ZUZ Ó / UUU l zu in FIGURE 2. The closing device 58, as shown in FIGURE 3, comprises a first closing member 60 and at least one second closing member 62 configured to interact with each other such that they separate the secondary space 28 from the first portion 46 from the second portion 48. According to an alternative embodiment, the first closing member 60 and / or the second closing member 62 comprise at least one securing plate 68 for securing to the secondary space 28. It should be noted that the first closing member 60 and / or the second closing member 62 can form with this securing plate 68 a single piece before being mounted in the secondary space 28. As shown in FIGURES 3 and 4, each of the closure members 60, 62 has an L-shaped profile seen in a cross-sectional plane of the roof wall, for example, along the section plane of FIGURE 2. Each closure member 60, 62 comprises a first part 64 and at least a second part 66 extending in intersecting planes. As can be seen more particularly in FIGURE 4, each closure member 60, 62 is a bent metal plate comprising the first part 64 and the second part 66, each plate extending at least in the longitudinal direction L of the tank 1. More specifically, the closure device 58 comprises a succession of plates placed one after the other to form a closure strip for the secondary space 28. Furthermore, the plates extend around the periphery of the second portion 48, i.e., along the entire perimeter of the second portion 48, and can therefore extend primarily in the longitudinal L or transverse T directions. The interaction of each of the portions 64, 66 of each of the closing members 60, 62 with certain components of tank 1 will now be described. As shown in FIGURE 3, the first part 64 of the first sealing member 60 extends in this case at least partially between the secondary space 28 and the primary space 30 of the first portion 46. The secondary thermally insulating barrier 32 has a zone for securing the first part 64 of the first sealing member 60. Specifically, the secondary space 28 comprises a securing plate 68 to which the first part 64 of the first sealing member 60 is secured, this securing plate 68 lying in the extension of the secondary sealing membrane 34. According to an alternative of the invention, the retaining plate 68 and the first locking member 60 form a single unit, meaning that separation of one of the two elements would result in the destruction of one and / or both elements. It should be noted that in this configuration, the first part 64 of the first locking member 60 is in direct contact with, or even secured directly to, the secondary space 28. ΜΛ / a / ZUZ Ó / UUU l zu secondary 28. More specifically, and as shown in FIGURES 3 and 4, the securing plate 68 in this case extends the rigid secondary sealing membrane 40, the flexible secondary sealing membrane 42 covering at least partially the securing plate 68, such that it ensures a seal between the securing plate 68 and the rigid secondary sealing membrane 40. The securing plate 68 is secured by a retaining member 70, such as a screw or rivet, for example, to the secondary thermally insulating barrier 32. The first part 64 of the closing member is secured to the securing plate 68, for example, by means of a weld bead, such that the first part 64 of the first closing member 60 is arranged at least between the securing plate 68 and the primary space 30. 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 securing plate 68, such that a seal is ensured between the securing plate 68 and the secondary sealing membrane 34. In this alternative, the rigid secondary sealing membrane 40 is partially joined to the securing plate 68 with the flexible secondary sealing membrane 42, which at least partially covers the securing plate 68 and the rigid secondary sealing membrane 40. As shown in FIGURE 3, the secondary thermally insulating barrier 32 comprises at least one self-supporting, thermally insulating panel 71 having an outer face 72 secured to the supporting structure 4 by a securing element 74, such as a putty, for example, an inner face 76 to which the securing plate 68 of the secondary space 28 is secured, and a face of thickness 78 extending between the outer face 72 and the inner face 76 and facing the second portion 48 of the roof wall. In addition, each of the faces 72, 76, 78 of the self-supporting panel 71 includes a plywood plate 81. It is on or in these plywood plates that the retaining member 70 and / or the securing device 84 are secured, in particular by screwing or riveting. The self-supporting panel 71 has a chamfer 80 connecting the inner face 76 to the thick face 78 of the secondary thermally insulating barrier 32. The first closure member 60 comprises a folded part 82 connecting the first part 64 to the second part 66 of the first closure member 60, the folded part 82 of the first closure member 60 being arranged in line with the chamfer 80 on the self-supporting panel 71, i.e., opposite this chamfer. Furthermore, each closing member 60, 62 in this case comprises a folded portion 82 connecting the first portions 64 to the respective second portions 66 of each of the closing members 60, 62. By virtue of this folded portion 82, at least the first closing member 60 and the second closing member 62 of the closing device 58 are deformable. The various components of the roof wall can be caused to contract and / or expand, for example, due to swelling movements or a sudden temperature change, particularly during the loading or unloading phase of the tank according to the invention. The first closing member 60 and the second closing member 62 of the closing device 58 are configured to adapt their shapes to the movements of the roof wall components. More specifically, each part 64, 66 of each closing member 60, 62 can move closer together and further apart under the effect of the stresses described above. According to the invention, at least one of the portions 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 the securing device 84 arranged in the thickness of the storage structure 2. In other words, at least one of the portions 64, 66 of one and / or the other of the closing members 60, 62 is in contact with and secured by the securing device 84 to one of the portions 46, 48, at least one of the portions 64, 66 of one or the other of the closing members that extend in a direction perpendicular to the main extension plane of the portions 46, 48. As shown in FIGURE 3, the first closing member 60 is positioned against the secondary thermal insulation barrier 32 such that the second part 66 of the first closing member 60 extends along the face of thickness 78 of the secondary thermal insulation barrier 32. The second part 66 of the first closing member 60 is rigidly secured to the secondary thermal insulation barrier 32 on the face of thickness 78 by the securing device 84, which extends at least partially into the plywood plate 81 of the face of thickness 78. The securing device 84 is possibly, for example, a screw or a rivet. Advantageously, the securing device 84 is a wood screw. It will be understood from the above that the securing device 84 is installed on a terminal portion of the secondary thermally insulating barrier 32. In other words, the securing device 84 extends across the face of thickness 78 of the self-supporting panel 71, the face that extends between the outer face 72 and the inner face 76 of the self-supporting panel, to secure the first closing member 60 to the self-supporting panel 71. According to the example shown in FIGURE 3, the second part 66 of each closure member 60, 62 extends in a plane perpendicular to the planes in which the first parts 64 of the first and second closure members 60, 62 extend. The second part 66 of the first closure member 60 extends in this way from the bent part 82 of the first closure member 60 into the support structure 4, the second part 66 of the second closure member 62 extending from the bent part 82 of the second member ML / a / ZUZ Ó / UUU l closure 62 towards the internal volume of the tank. The second part 66 of each of the closure members 60, 62 comprises an end 86, the second part 66 of each of the closure members 60, 62 is in contact with the second part 66 of the other closure member 60, 62 at least over an area extending between the end 86 of the second part 66 of the first closure member 60 and the end 86 of the second part 66 of the second closure member 62. It should be noted in this case that the second part 66 of the first closing member 60 is flanked, on one side, by the plywood plate 81 of the face thickness 78 and, on the other side, by the second part 66 of the second closing member 62. Each closing member 60, 62 is secured to the other closing member 60, 62 by at least one weld bead. More specifically, the second part 66 of the second closing member 62 is secured to the second part 66 of the first closing member 60 by means of, for example, at least one weld bead made along the end 86 of the second part 66 of the first closing member 60 on the second part 66 of the second closing member 62. In an alternative embodiment to that described above, the second part 66 of the second closing member 62 is secured by the locking device 84 to the plywood plate 81 of the thick face, the second part 66 of the first closing member 60 being secured in turn to the second part 66 of the second closing member 62. Therefore, the second part 66 of the second closing member 62 is flanked, on one side, by the plywood plate 81 of the thick face 78 and, on the other side, by the second part 66 of the first closing member 60. As shown in FIGURE 3, the first part 64 of the second closing member 62 extends at least partially between the sealed and thermally insulating layer 50 of the second portion 48 and the support structure 4. The first part 64 of the second closing member 62 is secured to the support structure 4. For this purpose, the support structure 4 comprises an insert piece 88, also visible in FIGURE 4, against which the first part 64 of the second closing member 62 is secured. According to an example of the invention, the insert piece 88 of the support structure is made of metal, the first part 64 of the second closing member 62 being secured to the insert piece 88 of the support structure 4 by at least one weld bead. According to the example shown here in FIGURE 3, the second parts 66 of the closing members 60, 62, part of the thermally insulating wall 52 and part of the primary thermally insulating barrier 36 help to delimit a cavity 90 filled with a thermally insulating component, such as glass wool, for example. The invention also relates to a method for assembling the U-shaped joint zone of tank 1 comprising at least seven steps carried out chronologically one after the ML / a / ZUZ Ó / UUU l zu otra. However, other assembly steps not listed may be inserted between these seven steps. This assembly method comprises a first step in which the secondary thermal insulating barrier 32 is mounted against the support structure 4 of the tank 1. For this purpose, at least one self-supporting panel 71 is pre-assembled, this self-supporting panel 71 consisting mainly of a thermal insulation block flanked by two plywood plates, this self-supporting panel 71 being adhesively bonded to the support structure 4, with putty, by way of example. The method for assembling the U-joint zone comprises a second step in which the first part 64 of the first closing member 60 is fitted against the securing plate 68 of the secondary thermal insulating barrier 32, the securing plate 68 being placed on the inner face 76 of the self-supporting panel 71, the second part 66 of the first closing member 60 is fitted against the thick face 78 of the self-supporting panel 71 forming the secondary thermal insulating barrier 32. The second part 66 of the first closing member 60 is then secured to the thick face 78 of the self-supporting panel 71 of the secondary thermal insulating barrier 32 by the securing device 84. The method for assembling the joining zone U comprises a third step in which the first part 64 of the first closing member 60 is secured to the securing plate 68 of the secondary thermally insulating barrier 32, for example, by means of a weld bead. The method for assembling the joining zone U comprises a fourth step in which the first part 64 of the second closing member 62 is fitted against the support structure 4, and the second part 66 of the second closing member 62 is fitted against the second part 66 of the first closing member 60. The second part 66 of the second closing member 62 is then secured to the second part 66 of the first closing member 60, for example, by means of a weld bead. The first part 64 of the second closing member 62 is, in turn, secured to the insert piece 88 of the support structure 4, for example, by means of another weld bead. These last two sub-steps can be carried out either one before the other. The method for assembling the bonding zone U includes a step in which the secondary sealing membrane 34 is fitted against the secondary thermal insulation barrier 32. This step can be performed between the first and any of the other steps of the method. More specifically, the rigid secondary sealing membrane 40 is adhesively bonded against the secondary thermal insulation barrier 32 such that the rigid secondary sealing membrane 40 is in the same plane as the securing plate 68 of the secondary thermal insulation barrier 32. The flexible secondary sealing membrane 42 is then adhesively bonded against the rigid secondary sealing membrane 40 and at least ML / a / ZUZ Ó / UUU l ¿u partially against the securing plate 68 of the secondary thermally insulating barrier 32, thus covering the joint between the secondary sealing membrane 34 and the securing plate 68. The method for assembling the joining zone U comprises a sixth step in which the primary thermally insulating barrier 36 is fitted against the secondary space 28, part of the primary thermally insulating barrier 36 that partially covers the first part 64 of the first closing member 60. The thermally insulating wall 52 is then fitted against the storage structure 2 at least in the same principal plane of extension as that of the first portion 46, part of the thermally insulating wall 52 that partially covers the first part 64 of the second closing member 62. The method for assembling the joint zone U comprises a seventh step in which the primary sealing membrane 38 and the impermeable membrane 54 are fitted against the primary thermal insulating barrier 36 and the thermally insulating wall 52, respectively. The primary sealing membrane 38 and the impermeable membrane 54 cover the joint between the primary thermal insulating barrier 36 and the thermally insulating wall 52. The primary thermal insulating barrier 36 and the thermally insulating wall 52 are in communication with each other, forming a common volume through which an intercooling fluid, such as dinitrogen, passes. The sealing membrane 38 and the impermeable membrane 54, along with the first portion 46 and the second portion 48, are sealed against the fluid circulating and / or stored in the internal volume 45 of tank 1, thus forming part of this common volume. The invention also relates to a method for loading or unloading liquefied gas contained in the tank described above, wherein a cold liquid product is transported through insulated pipes to or from a floating or land-based storage facility, to or from a tank 1 as described herein. However, the invention is not limited to the means and configurations described and illustrated herein, but extends to any equivalent means and any equivalent configuration, and to any technically functional combination thereof. In particular, the position of the second portion and the locking device, in this case arranged on the central facets of the roof wall, can, in another embodiment, be adjusted to at least one other facet and even to another wall of the storage structure. Furthermore, the orientation of each element is likely to change depending on the position of the second portion within the tank.
Claims
1. A sealed and thermally insulated tank (1) for the transport and / or storage of liquefied natural gas, comprising at least a support structure (4) and a storage structure (2) surrounded by the support structure (4), the storage structure (2) comprising at least a first portion (46) and a second portion (48) that seal against each other, the first portion (46) and the second portion (48) extending at least partially in the same plane parallel to the support structure (4), the storage structure (2) having a thickness from the outside to the inside of the tank (1) in a direction perpendicular to the plane of the support structure (4), the tank (1) comprising a closing device (58) arranged at least partially within the thickness of the storage structure (2),the closing device (58) comprising at least a first closing member (60) and a second closing member (62) configured to interact with each other such that the first portion (46) is separated from the second portion (48), in at least one of the closing members (60, 62) comprising a first part (64) and a second part (66) extending in intersecting planes, characterized in that at least one of the parts (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 a securing device (84) arranged in the thickness of the storage structure (2).
2. The tank (1) according to claim 1, characterized in that at least one of the closing members (60, 62) has an L-shaped profile seen in a section plane passing through the closing device (58).
3. The tank (1) according to any of the preceding claims, characterized in that at least one of the closing members (60, 62) is secured to the other closing member (60, 62) by at least one weld bead.
4. The tank (1) in accordance with any of the preceding claims, characterized in that the first closing member (60) and / or the second closing member (62) of the closing device (58) are elastically deformable.
5. The tank (1) according to any of the preceding claims, characterized in that one of the closing members (60, 62) is connected to at least one of the portions (46, 48) by the securing device (84) arranged in the thickness of the storage structure (2), the other closing member (60, 62) being connected to the support structure (4).
6. The tank (1) according to claim 5, characterized in that the first portion (46) comprises a secondary space (28) and a primary space (30), the secondary space (28) comprising, successively in the thickness direction from the outside to the inside of the tank (1), a secondary thermal insulating barrier (32) adapted to be in contact with the support structure (4) and a secondary sealing membrane (34) resting on the secondary thermal insulating barrier (32), the securing device (84) extending at least partially into the secondary thermal insulating barrier (32), the primary space (30) comprising, successively in the thickness direction from the outside to the inside of the tank (1),a primary thermally insulating barrier (36) resting on the secondary sealing membrane (34) and a primary sealing membrane (38) resting on the primary thermally insulating barrier (36) and proposed to be in contact with the fluid contained in the tank (1), the second portion (48) comprising a thermally insulating wall (52) adapted to be in contact with the support structure (4) and an impermeable membrane (54) resting on the thermally insulating wall (52) and proposed to be in contact with the fluid contained in the tank (1).
7. The tank (1) according to claim 6, characterized in that the secondary space (28) comprises a securing plate (68) arranged between the secondary thermal insulating barrier (32) and the primary space (30), the first part (64) of the first closing member (60) being connected to the securing plate (68) by at least one weld bead, the second part (66) of the first closing member (60) being connected to the secondary thermal insulating barrier (32) by the securing device (84) arranged in the thickness of the storage structure (2).
8. The tank (1) according to claim 6, characterized in that the support structure (4) comprises an insert piece (88), the first part (64) of the second closing member (62) being connected to the insert piece (88) by at least one weld bead, the second part (66) of the second closing member (62) being connected to the secondary thermally insulating barrier (32) by the securing device (84) arranged in the thickness of the storage structure (2).
9. The tank (1) according to claim 7, characterized in that at least the secondary space (28) comprises at least one thermally insulating self-supporting panel (71) having an inner face (76) oriented towards the interior of the tank (1), an outer face (72) oriented towards 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 closing member (60) comprising a chamfer (80) connecting the inner face (76) and the thickness face (78) of the self-supporting panel (71).
10. The tank (1) according to claim 9, characterized in that the thickness face (78) of the self-supporting panel (71) comprises a plywood panel (81) that receives the securing device (84).
11. The tank (1) according to any of claims 9 or 10, characterized in that the first closing member (60) comprises a folded part (82) connecting the first part (64) to the second part (66) of the first closing member (60), the first closing member (60) being positioned against the inner face (76) and the thickness face (78) of the self-supporting panel (71) of the secondary space (28) such that the folded part (82) of the first closing member (60) is arranged in line with the chamfer (80) on the self-supporting panel (71).
12. A transport and / or storage unit characterized in that it comprises at least one tank (1) according to any one of claims 1 to 11, wherein the transport and / or storage unit consists of a vessel, a barge, a reliquefaction unit, a gasification unit, an onshore structure or a gravity platform.
13. A method for assembling the joining zone (U) between a first portion (46) and a second portion (48) of a tank (1) in accordance with any of claims 1 to 11 in conjunction with claim 6, characterized in that the tank (1) comprises a support structure (4) surrounding the storage structure (2), the method comprising a first step in which the secondary thermally insulating barrier (32) is fitted against the support structure (4).
14. The method for assembling the joining zone (U) according to claim 13, characterized in that it comprises a second step in which the second part (66) of the first closing member (60) or of the second closing member (62) is secured in a thickness of the secondary thermally insulating barrier (32) by the securing device (84).
15. The method for assembling the joining zone (U) according to claim 14, the secondary thermal insulating barrier (32) comprising a securing plate (68), the method characterized in that it comprises a third step, in which the first part (64) of the first closing member (60) is secured to the secondary thermal insulating barrier (32) on this securing plate (68) by a weld bead.
16. The method for assembling the joining area (U) according to claim 15, the support structure (4) comprising an insert piece (88), the method characterized in that it comprises a fourth step in which the second part (66) of the second closing member (62) is secured to the second part (66) of the first closing member (60) by a weld bead, and the first part (64) of the second closing member (62) is attached to the insert piece (88) of the support structure (4) by another weld bead.
17. The method for assembling the joining zone (U) according to claim 16, characterized in that it comprises a fifth step in which the secondary sealing membrane ML / a / ZUZ Ó / UUU l zu (34) is fitted against the secondary thermally insulating barrier (32).
18. The method for assembling the joining zone (U) according to claim 17, characterized in that it comprises a sixth step, wherein the primary thermal insulating barrier (36) is fitted against the secondary space (28), part of the primary thermal insulating barrier (36) partially covering the first part (64) of the first closing member (60), and the thermal insulating wall (52) is fitted against the support structure (4) at least in the main plane of extension of the secondary space (28), part of the thermal insulating wall (52) being arranged in line with the first part (64) of the second closing member (62) along the thickness.
19. The method for assembling the joining zone (U) according to claim 18, characterized in that it comprises a seventh step, in which the primary sealing membrane (38) and the waterproof membrane (54) are fitted against the primary thermally insulating barrier (36) and against the thermally insulating wall (52), respectively, the primary sealing membrane (38) and the waterproof membrane (54) extending in a common plane.
20. A method for loading or unloading liquefied gas contained in a tank (1) according to any of claims 1 to 11, characterized in that a cold liquid product is conveyed through insulated pipes from or to a floating or land-based storage facility, to or from a tank (1) according to any of claims 1 to 10.