Guide structure for loading / unloading a tower of tanks for storing and / or transporting liquefied gas

Abstract

The invention relates to a tank for transporting and / or storing a liquefied gas, the tank comprising: a load-bearing structure; a plurality of walls (27), each wall comprising, in the thickness direction (E) of the wall (27), at least one thermally insulating layer (41) against the load-bearing structure and at least one sealing membrane against the thermally insulating layer (41), said plurality of walls (27) comprising at least one bottom wall (27); a guiding structure (77) configured to receive a tower for loading and / or unloading the liquefied gas contained in the tank, the guiding structure (77) comprising a base (93) against the load-bearing structure, the thermally insulating layer (41) comprising at least one self-supporting heat-resistant panel (43). The thermally insulating layer (41) comprises a gap (151) delimited by a portion (96) of the self-supporting heat-resistant panel (43) and the load-bearing structure, the gap (151) being configured to accommodate at least a portion of the base (93) of the guiding structure (77).

Description

Technical Field

[0001] This invention relates to the field of tanks suitable for containing liquefied gases. More specifically, this invention relates to the bottom wall of a tank, such as the bottom wall of a gravity platform or land container, for storing liquefied gases, such as liquefied natural gas (LNG) or liquefied petroleum gas (LPG). Background Technology

[0002] In the prior art, sealed, insulated tanks for storing liquefied gases are known, mounted on gravity platforms or ships. These are typically equipped with towers for loading / unloading the liquefied gases contained within the tank. The loading / unloading towers typically extend from the upper wall of a supporting structure, which represents the basic structure of the internal hull of the gravity platform or ship. The tanks may also include guiding structures fixed to the bottom wall of the tank and / or the supporting structure of the storage tank. The guiding structures are configured to hold the bottom portion of the loading / unloading tower in a given position relative to the horizontal plane while allowing vertical translational movement of the loading / unloading tower.

[0003] When the tank contains liquefied gas, the guide structure is immersed in the liquefied gas. Therefore, it is necessary to provide insulation for the guide structure and thermal continuity with the bottom wall of the tank through which the guide structure passes. Currently, the technical features of the guide structure sometimes make it difficult to achieve insulation and thermal continuity with the bottom wall.

[0004] Furthermore, gravity platform tanks are much larger in volume than ship tanks and offer only limited tolerance to operating loads and point loads involved in loading or unloading tanks with liquefied gases. In addition, the guiding structure is subjected to high mechanical and thermal stresses, particularly those caused by the loading / unloading tower, resulting in premature fatigue of the guiding structure and its bottom wall. Summary of the Invention

[0005] The first objective of this invention is to mitigate at least one of the aforementioned disadvantages and further impart other advantages by proposing a novel wall for liquefied gas storage and / or transport tanks, particularly for gravity platforms.

[0006] A second objective of this invention is to increase the mechanical strength of the attachment of the guide structure at the bottom wall.

[0007] A third objective of the present invention is to achieve better thermal insulation for the attachment of the guiding structure at the bottom wall.

[0008] The fourth objective of this invention is to minimize the structural deformation of the guiding structure.

[0009] Therefore, the present invention provides a tank for transporting and / or storing liquefied gases, comprising: a support structure; a plurality of tank walls, each tank wall including at least one insulating layer abutting against the support structure and at least one sealing membrane abutting against the insulating layer in the thickness direction of the wall, the plurality of tank walls including at least one bottom wall; a guide structure configured to receive a tower for loading and / or unloading liquefied gases contained in the tank, the guide structure being arranged against the support structure and extending at least partially within the tank, the guide structure including a base supporting the support structure, the insulating layer including at least one self-supporting heat-resistant panel arranged at least partially around the guide structure, characterized in that the insulating layer includes a gap in the thickness direction of the bottom wall defined by a portion of the self-supporting heat-resistant panel and the support structure, the gap being configured to at least partially accommodate the base of the guide structure.

[0010] "Self-supporting" here and in the remainder of this application must be understood as the ability of a self-supporting heat-resistant panel to withstand the weight of an object placed on top of it, such as liquefied natural gas, without significant deformation, and within the limits of its mechanical strength.

[0011] The gaps provided in the insulation layer made of self-supporting heat-resistant panels are able to receive a portion of the base of the guide structure. Therefore, the self-supporting heat-resistant panels can be positioned as close as possible to the guide structure, thereby providing partial insulation for the guide structure.

[0012] According to one embodiment, the thickness of the gap is between 25 mm and 70 mm, inclusive. The thickness is measured in a direction parallel to the thickness direction from the inner surface of the support structure to the outer surface of the portion of the self-supporting heat-resistant panel.

[0013] According to one embodiment, the portion of the self-supporting heat-resistant panel that defines the gap in the thickness direction comprises plywood or composite material board.

[0014] According to one embodiment, a portion of the self-supporting heat-resistant panel rests on the base of the guide structure, specifically on the plate of the base.

[0015] According to one embodiment, a spacer is disposed between the base of the guide structure (particularly on the plate of the base) and said portion of the self-supporting heat-resistant panel resting on the base of the guide structure.

[0016] According to one embodiment, the spacer is an insert or a putty bead or a combination of both.

[0017] According to one embodiment, the can includes at least one blocking device configured to fix the guide structure at least in a direction perpendicular to the thickness direction of the bottom wall.

[0018] According to one embodiment, the blocking device is housed in the gap.

[0019] According to one embodiment, the blocking device is made of metal.

[0020] According to one embodiment, another portion of this part of the self-supporting heat-resistant panel rests on the blocking device.

[0021] According to one embodiment, the locking member is arranged between the blocking device and another part of the self-supporting plate.

[0022] According to one embodiment, the locking member is an insert or a putty bead or a combination of both.

[0023] According to one embodiment, the gap, in a direction perpendicular to the thickness direction, is defined by the edge of the self-supporting heat-resistant panel extending between the outer surface of the portion of the self-supporting heat-resistant panel and the inner surface of the support structure, and by the guide structure.

[0024] According to one embodiment, the blocking device is arranged between the edge of the self-supporting heat-resistant panel and the base of the guiding structure.

[0025] According to one embodiment, an insulating member is disposed between the base of the guide structure and the support structure. The insulating member also has the function of adjusting its position along the vertical axis of the guide structure.

[0026] According to one embodiment, the insulation layer is a secondary insulation layer, the sealing film is a primary sealing film, and the tank includes a primary insulation layer and a secondary sealing film, with the secondary sealing film abutting against the secondary insulation layer, the primary insulation layer abutting against the secondary sealing film, and the primary sealing film abutting against the primary insulation layer.

[0027] According to one embodiment, the primary insulation layer and / or the secondary insulation layer include a plurality of self-supporting heat-resistant panels, each self-supporting heat-resistant panel including a polyurethane foam block, and at least one plywood or composite board abutting against the polyurethane foam block.

[0028] According to one embodiment, the support structure is made of a material selected from the group consisting of metals, metal alloys, concrete, and mixtures thereof.

[0029] The present invention also provides a transport and / or storage unit comprising at least one tank according to the invention, the transport and / or storage unit being selected from the group consisting of methane tankers, liquefied petroleum gas tankers, barges, reliquefaction units, gasification units, land structures (e.g., land containers) and gravity platforms.

[0030] According to one embodiment, the transport and / or storage unit includes a base structure on which the tank according to the invention is anchored, the base structure being made of concrete.

[0031] The present invention also proposes a system for conveying liquefied gas, the system comprising a gravity platform according to the invention, an insulating pipe arranged to connect a tank mounted in the base structure of the gravity platform to a ship, and a pump for driving the liquefied gas from the tank on the gravity platform through the insulating pipe to the ship.

[0032] The present invention also provides a method for loading or unloading a gravity platform according to the invention, wherein liquefied gas is transported from a tank of the gravity platform to a ship via an insulated pipe.

[0033] This disclosure also includes a tank for transporting and / or storing liquefied gases, the tank comprising: a support structure; a plurality of tank walls, each tank wall including, in the thickness direction of the wall, at least one insulating layer abutting against the support structure and at least one sealing membrane abutting against the insulating layer and for contacting the liquefied gases within the tank, the plurality of tank walls including at least one bottom wall; and a guide structure configured to receive a loading and / or unloading tower arranged against the support structure, characterized in that the tank includes a plurality of blocking devices fixed to the support structure and contacting the base of the guide structure to prevent movement of the guide structure in a direction perpendicular to the thickness direction of the bottom wall. Attached Figure Description

[0034] Other features and advantages of the invention will become more apparent, on the one hand, from reading the following description, and on the other hand, from referring to the various embodiments given in a non-limiting manner in the accompanying drawings, in which:

[0035] Figure 1 This is a schematic perspective view of the can according to the present invention;

[0036] Figure 2 yes Figure 1 A schematic diagram of the cross-section of the central tank in a vertical plane;

[0037] Figure 3 When viewed from the direction of wall thickness, Figure 2 A schematic diagram of the structure of the tank wall;

[0038] Figure 4 yes Figure 1 A detailed sectional view of the guide structure in the vertical plane, which is used for guiding. Figure 1 The loading / unloading tower moves vertically in translation;

[0039] Figure 5 yes Figure 4 A detailed view of the blocking device of the guide structure shown;

[0040] Figure 6 This is a schematic diagram of a methane tanker and a loading / unloading gravity platform including the tank according to the invention. Detailed Implementation

[0041] First, it should be noted that although the accompanying drawings disclose embodiments of the invention in a detailed manner, they can certainly be used to better define the invention if necessary. It should also be noted that in all the drawings, similar and / or elements having the same function are represented by the same numerals.

[0042] In the following description, in Figure 1 and 2 as well as Figure 4 and 5 In this diagram, the directions of the longitudinal axis L, the transverse axis T, and the vertical axis V are represented by a trihedron (L, V, T). The horizontal plane is defined as a plane perpendicular to the vertical axis, the longitudinal plane is defined as a plane perpendicular to the transverse axis, and the transverse plane is defined as a plane perpendicular to the longitudinal axis.

[0043] The terms “external” and “internal” are used to define the relative position of one element with respect to another element about the inside and outside of a container.

[0044] refer to Figure 1 A sealed and insulated liquefied gas tank 21 is anchored in a concrete support structure 3. The support structure 3 is formed, for example, by the base structure of the gravity platform 1. In the following text, the terms "base structure" and "support structure" are used interchangeably and have the same reference numerals.

[0045] In an embodiment not shown, the support structure 3 is formed by a double hull of a vessel. The vessel can be a methane tanker or an LPG tanker. The support structure 3 can also be formed by a double-holding structure, such as a barge, reliquefaction unit, gasification unit, or a land-based structure (e.g., a land container).

[0046] More accurately, reference Figure 2 , Figure 2 yes Figure 1 The tank 21 is shown in a cross-sectional view at section 150. The supporting structure 3 includes a double-layer bottom partition wall 5, an upper partition wall 9, and a double-layer lateral partition wall 7 connecting the double-layer bottom partition wall 5 to the upper partition wall 9. Each double-layer partition wall 5, 7 includes an outer partition wall 11 and an inner partition wall 13 made of concrete. The inner partition wall 13 and the upper partition wall 9 define the overall shape of the tank 21. The outer partition wall 11 and the inner partition wall 13 are connected to each other by concrete spacers 15.

[0047] The lower portion of the base structure 3 includes a ballast tank 17. The ballast tank 17 is located between the inner partition wall 13 and the outer partition wall 11 of the double-bottom partition wall 5. When the gravity platform 1 is in its mining position, the ballast tank 17 is filled with seawater, thereby pressurizing the gravity platform 1 and causing it to sink. As a result, the gravity platform 1 is partially resting on the seabed.

[0048] It should be noted that the base structure 3 also includes inserts, such as metal inserts, embedded in the concrete of the base structure. These inserts extend horizontally and are positioned vertically below the guide structure 77, as will be described below, between the guide structure 77 and the concrete.

[0049] Reference Figure 2 and Figure 3 The tank 21 includes multiple walls 23, 25, and 27, each wall abutting against the inner partition wall 13 and the upper partition wall 9 of the base structure 3. Therefore, the tank 21 includes an upper wall 23 disposed on the inner surface of the upper partition wall 7 and a bottom wall 27 disposed on the inner surface of the inner partition wall 13. As described above, the upper partition wall 23 and the bottom wall 27 extend in a principal plane substantially parallel to the horizontal plane. The upper wall 23 is substantially parallel to the bottom wall 27 and does not intersect with the bottom wall 27. Here and throughout all subsequent content, it must be understood that "substantially" means that manufacturing tolerances and any assembly tolerances must be taken into account.

[0050] The upper wall 23 and the bottom wall 27 are connected to each other by lateral walls 25 disposed on the inner surface of another inner partition wall 13. Each lateral wall 25 extends from one edge of the bottom wall 27 to the edge of the upper wall 23 in a plane substantially perpendicular to the horizontal plane. The tank 21 has an overall shape of a parallelepiped.

[0051] Reference Figure 3 Each wall 23, 25, 27 includes, in the thickness direction E of the wall 23, 25, 27, a secondary insulation layer 41 held on the corresponding partition wall of the base structure 3, a secondary sealing membrane 51 abutting the secondary insulation layer 41, a primary insulation layer 61 abutting the secondary sealing membrane 51, and a primary sealing membrane 71 intended to contact the liquefied natural gas contained in the tank 21 and abutting the primary insulation layer 61.

[0052] The secondary insulation layers 41 of the walls 23, 25, and 27 of tank 21 are interconnected in such a way that a continuous and sealed secondary insulation space is formed between the base structure 3 and the secondary sealing membrane 51. Similarly, the primary insulation layers 61 of the walls 23, 25, and 27 of tank 21 are interconnected in such a way that a continuous and sealed primary insulation space is formed between the secondary sealing membrane 51 and the primary membrane 71.

[0053] The secondary insulation layer 41 includes a plurality of self-supporting heat-resistant panels 43. The self-supporting heat-resistant panels 43 have a generally parallelepiped shape. The self-supporting heat-resistant panels 43 may have other shapes, such as parallelepiped shapes, particularly with square or rectangular bases, or right prism shapes with hexagonal bases. The self-supporting heat-resistant panels 43 are arranged in parallel rows.

[0054] Each self-supporting heat-resistant panel 43 includes a heat-resistant polymer foam block 45 resting on an outer rigid panel 47. The rigid outer panel 47 is, for example, plywood. The rigid outer panel 47 is bonded to the heat-resistant polymer foam block 45. The heat-resistant polymer foam can be, in particular, a rigid polyurethane-based foam. Glass fibers can be embedded in the polyurethane foam to reinforce it. In embodiments not shown, the rigid outer panel 47 is made of at least one composite material.

[0055] For example, due to manufacturing inaccuracies, the inner surfaces of the inner partition wall 13 and the upper partition wall 9 may differ significantly from the theoretical areas provided for the base structure. These differences are compensated for by having the self-supporting heat-resistant panel 41 supported against the base structure by means of beads of polymerizable resin 40 or putty.

[0056] The self-supporting heat-resistant panel 41 is anchored to the inner partition wall 13 and the upper partition wall 9 by bolts (not shown) welded to the inner surface of the inner partition wall 13.

[0057] The secondary sealing film 51 comprises a plurality of rigid sealing layers 53 made of 0.07 mm thick aluminum foil, sandwiched between two glass fiber pads impregnated with polyamide resin. The rigid sealing layers 53 are bonded to the polymer foam block 45 of the self-supporting heat-resistant panel 43, for example by a two-component polyurethane adhesive.

[0058] To impart some flexibility to the secondary membrane and ensure its continuity between two adjacent rigid sealing layers 53, a flexible sealing layer 55 is bonded to the adjacent peripheral edges of the two adjacent rigid sealing layers 53. The flexible sealing layer 65 consists of a three-layer composite material: two outer layers are fiberglass pads, and the middle layer is a thin metal foil, such as aluminum foil approximately 0.1 mm thick. This metal foil ensures the continuity of the secondary sealing membrane.

[0059] The primary insulation layer 61 comprises a plurality of self-supporting heat-resistant panels 63, which are generally parallelepiped in shape. The self-supporting heat-resistant panels 63 of the primary insulation layer 61 can have other shapes, such as cubic shapes. Figure 3 In the embodiment shown, the self-supporting heat-resistant panel 63 of the primary insulation layer 61 is offset relative to the self-supporting heat-resistant panel 43 of the secondary insulation layer 41, such that each primary insulation panel 63 of the primary insulation layer 61 extends over the four self-supporting heat-resistant panels 43 of the secondary insulation layer 41.

[0060] Each self-supporting heat-resistant panel 63 of the primary insulation layer 61 includes a heat-resistant polymer foam block 65, such as a rigid polyurethane-based foam block. A first side of the polymer foam block 65 is bonded to the secondary sealing membrane 51, and a second side opposite the first side is covered by a rigid inner panel 69. Fiberglass may be embedded in the polymer foam to reinforce it. The rigid inner panel 69 of the self-supporting heat-resistant panel 63 of the primary insulation layer 61 is made of, for example, plywood or a composite material.

[0061] The primary sealing membrane 71 comprises multiple metal plates welded together. Figure 3 In the illustrated embodiment, the primary sealing membrane 71 includes corrugations 75 in a metal sheet, which allow the primary sealing membrane 71 to deform under the heat and mechanical loads generated by the liquefied gas in the tank 21. The primary sealing membrane 71 includes two sets of mutually perpendicular corrugations 75. The corrugations 75 protrude into the interior of the tank 21. Each rigid inner plate 69 of the self-supporting heat-resistant panel 63 of the primary insulation layer 61 is equipped with a metal assembly plate (not shown) for anchoring the corrugated metal sheet of the primary sealing membrane 71. The assembly plates can be assembled together, for example, by welding.

[0062] refer to Figure 1 Tank 21 includes a guide structure 77 arranged against the support structure 3. The guide structure 77 is configured to receive a tower 29 for loading and / or unloading liquefied gas contained in tank 21.

[0063] The loading / unloading tower 29 extends substantially the entire height of the tank 21, that is, from the lower wall to the upper wall, with its upper portion 33 overhanging from the upper wall. The loading / unloading tower 29 includes three vertical masts 31 connected together by crossbeams (not shown), defining a prism shape with a triangular cross-section. The vertical masts 31 are hollow to allow the passage of a power supply cable (not shown), which specifically supplies power to the pump for unloading the tank 21 (not shown) via the unloading line (not shown) of the loading / unloading tower 29. In embodiments not shown, the loading / unloading tower 29 may include two or four vertical masts.

[0064] The loading / unloading tower 29 includes a guide device 37 at its bottom portion 35 that mates with the guide structure 77 of the tank 21. The guide device 37 is designed to allow relative movement of the loading / unloading tower 29 with respect to the guide structure 77 in the height direction of the tank 21, so as to allow the loading / unloading tower 29 to contract or expand according to the temperature it experiences, while preventing horizontal movement of the lower portion 31 of the loading / unloading tower 29.

[0065] Now refer to Figure 4 The guide structure 77 is described in more detail in the region of the bottom wall 27 of tank 21 facing the central axis of loading / unloading tower 29. Figure 4 yes Figure 1 A view of the guide structure on section 200 shown. (For simplicity...) Figure 4 The primary sealing membrane 71 and the secondary sealing membrane 51 are not shown.

[0066] The guide structure 77 includes the base that supports and abuts the support structure 3.

[0067] The guide structure 77 includes a hollow lower portion 79, which is, for example, truncated conical, and connects to a straight cylindrical upper portion 78. This lower portion 79 is similar to the base of the guide structure 77 mentioned above. The upper portion 78 extends into the tank 21 in a manner that mates with the guide device 37 of the loading / unloading tower 29. The lower portion 79 extends through the thickness of the bottom wall 27 of the tank 21 to the primary sealing membrane 71.

[0068] The lower portion 79 or base includes at least one plate 93 supporting and abutting the support structure 3, the plane in which most of the plate 93 extends is perpendicular to the thickness direction E of the bottom wall 27. The plate 93 is the base portion extending in the gap 151 formed in the insulation layer 41.

[0069] The truncated conical lower portion or base 79 includes a small circular base 80 and a large circular base 81. The small base 80 and the large base 81 each extend in a plane perpendicular to the thickness direction E of the bottom wall 27. The diameter of the small base 80 is smaller than the diameter of the large base 81. The diameter of the upper portion 78 is substantially equal to the diameter of the small base 80. Furthermore, the large base 81 is closer to the support structure 3 than the small base 80. The lower portion 79 includes a radial wall 88 that extends from the outline of the small base 80 to the outline of the large base 81. In other words, the radial wall 88 connects the small base 80 to the large base 81, forming a cone. The radial wall 88 extends circumferentially around the small base 80 and circumferentially around the large base 81. The small base 80 is assembled to the upper portion 78 of the guide structure 77 by a first plate 82 extending in a plane perpendicular to the thickness direction E of the bottom wall 27. The first plate 82 can have various shapes. In the example shown, when viewed in a plane perpendicular to the thickness direction E of the bottom wall 27, the first plate 82 has a circular shape. The diameter of the first plate 82 is larger than the diameter of the small base 80. Therefore, the outer portion 83 of the first plate 82 extends from the small base 80 in the direction of the primary sealing film 71 to connect to the primary sealing film 71. The outer portion 83 of the first plate 82 is continuously disposed with the primary sealing film and contributes to its sealing and insulation. The inner portion 84 of the first plate 82 extends in a straight line with the outer portion 83 within the lower portion 79 of the guide structure 77.

[0070] The guide structure 77 includes a second plate 85 disposed between a small base 80 and a second base 81 in the lower portion 79 of the guide structure 77. The second plate 85 extends in a plane perpendicular to the thickness direction E of the bottom wall 27. The second plate 85 can have various shapes. In the example shown, when viewed in a plane perpendicular to the thickness direction E of the bottom wall 27, the second plate 85 has a circular shape.

[0071] The second plate 85 is arranged in a straight line with the secondary sealing membrane 51 for connection to the secondary sealing membrane 51. Therefore, the second plate 85 and the secondary sealing membrane 51 are at substantially the same level. The outer portion 86 of the second plate 85 extends around the lower portion 73 of the guide structure 77. This outer portion 86 of the second plate 85 is continuous with the secondary sealing membrane and contributes to its sealing and insulation. The outer portion 86 of the second plate 85 extends circumferentially from the radial wall 88 of the lower portion 79 of the guide structure 77. The outer portion 86 of the second plate 85 is intended to connect to the secondary sealing membrane 41.

[0072] The inner portion 87 of the second plate 85 extends within the lower portion 79 of the guide structure 77. Therefore, the internal space of the lower portion 79 is divided into a secondary portion 90 and a primary portion 91. The primary portion 91 is thus defined by the first plate 82, the second plate 85, and the radial wall 88 of the lower portion 79. The secondary portion 90 is defined by the second plate 85, the double-bottom partition wall 5 of the base structure 3, and the radial wall 88 of the lower portion 79 of the guide structure 77. Non-structural insulating filler (not shown) is arranged in the primary portion 91 and / or the secondary portion 90. The non-structural insulating filler is, for example, glass wool, mineral wool, or a mixture thereof. Therefore, heat conduction in the guide structure 77 is restricted.

[0073] The self-supporting heat-resistant panel 63 of the primary insulation layer 61 adjacent to the guide structure 77 is supported on at least one self-supporting heat-resistant panel 43 of the secondary insulation layer 41 and on the outer portion 86 of the second plate 85. The self-supporting heat-resistant panel 63 of the primary insulation layer 61 adjacent to the guide structure 77 is also supported on the outer portion 86 of the second plate 85. The lateral surfaces of the self-supporting heat-resistant panel 63 of the primary insulation layer 61 adjacent to the guide structure 77 are arranged abutting against the edge of the outer portion 84 of the first plate 82. To improve insulation, a non-structural insulating filler 92 is disposed between the self-supporting heat-resistant panel 63 of the primary insulation layer 61 adjacent to the guide structure 77 and the radial wall 88 of the lower portion 79 of the guide structure 77. The non-structural insulating filler 92 thus disposed is, for example, glass wool, mineral wool, or a mixture thereof.

[0074] The radial wall 88 of the lower portion 79 includes through holes 89. Some of the holes 89 in the radial wall 88 are arranged in such a way as to establish air communication between the secondary insulation space and the secondary portion 90 of the interior space of the lower portion 79. This facilitates the flow of inert gases, such as nitrogen or argon, between the secondary insulation space and the secondary portion 90. Some other holes 89 in the radial wall 88 are arranged in such a way as to establish air communication between the primary insulation space and the primary portion 91 of the interior space of the lower portion 79. This facilitates the flow of inert gases, such as nitrogen or argon, between the first insulation space and the first portion 91.

[0075] The guide structure 77 includes a plate 93 arranged circumferentially around a large base 81 surrounding the lower portion 79 of the guide structure 77. The plate 93 extends in a plane perpendicular to the thickness direction E of the bottom wall 27. Viewed from the plane perpendicular to the thickness direction E, the plate 93 has a square perimeter. The plate 93 supports and abuts against the inner partition wall 13 of the double-layered bottom partition wall 5 of the support structure 3. In other words, the guide structure 77 is supported on a base at least partially formed by the plate 93, which contacts the support structure 3 plane-to-plane. The plate 93 is secured to the support structure 3 by a system of nuts and bolts (not shown).

[0076] The insulating member 94 is inserted between the inner surface of the inner partition wall 13 and the plate 93 in a manner that interrupts the thermal bridge between the support structure 3 and the guide structure 77. The insulating member 94 is, for example, a plywood or composite material plate. The thickness of this insulating member also helps to adjust the height of the guide structure 77 in the vertical direction.

[0077] Considering the plate 93 of the guide structure 77, each self-supporting heat-resistant panel 43 of the secondary insulation layer 41 adjacent to the plate 93 includes a cutout 95 in order to be arranged as close as possible to the self-supporting heat-resistant panel of the secondary insulation layer 41. When projected in a plane including the thickness direction E of the bottom wall 27, the cutout 95 has a rectangular shape. The cutout 95 is formed in the lower portion of the self-supporting heat-resistant panel 43 of the secondary insulation layer 41 adjacent to the plate 93. The cutout 95 is defined by the upper middle portion 96 of the self-supporting heat-resistant panel 43 of the secondary insulation layer 41 adjacent to the plate 93 and the lateral middle edge 99 of the self-supporting heat-resistant panel 43 of the secondary insulation layer 41 adjacent to the plate 93. The lateral middle edge 99 extends between the outer middle surface 97 of the upper middle surface 96 of the self-supporting heat-resistant panel 43 of the secondary insulation layer 41 adjacent to the plate 93 and the inner surface of the inner partition wall 13 of the double bottom wall 5 of the support structure 3.

[0078] The upper middle portion 96 of the self-supporting heat-resistant panel 43 of the secondary insulation layer 41 adjacent to the plate 93 includes a plywood 98 or a composite material plate disposed at the outer middle surface 97. This allows for enhanced mechanical strength of the self-supporting heat-resistant panel 43 of the secondary insulation layer 41 adjacent to the plate 93.

[0079] Therefore, the secondary insulation layer 41 includes a gap 151, which is defined in the thickness direction E of the bottom wall 27 by the outer middle surface 97 of the upper middle portion 96 of the self-supporting heat-resistant panel of the secondary insulation layer 41 adjacent to the plate 93 and the inner surface of the inner partition wall 13 of the bottom double wall 5 of the support structure 3. In other words, the gap 151 is defined in the thickness direction E of the bottom wall 27 by the portion of the adjacent plate 93 of the self-supporting heat-resistant panel 43 of the secondary insulation layer 41 and the support structure 3. Therefore, the gap 151 at least partially accommodates the base, particularly the plate 93 of the guide structure 77, in a direction parallel to the thickness direction E of the bottom wall 27.

[0080] The thickness H of the gap 151 is between 25 mm and 70 mm, inclusive. The thickness H is measured in a direction parallel to the thickness direction E, from the inner surface of the inner partition wall 13 of the bottom double-layer partition wall 5 of the support structure 3 to the outer middle surface 97 of the upper middle portion 96 of the self-supporting heat-resistant panel 43 of the secondary insulation layer 41 adjacent to the plate 93. The thickness H of the gap 151 is greater than or equal to the thickness of the plate 93 measured in a direction parallel to the thickness direction E of the bottom wall 27.

[0081] The gap 151 is defined in the direction perpendicular to the thickness E of the bottom wall 27 by the lateral central edge 99 of the self-supporting heat-resistant panel 43 of the secondary insulation layer 41 adjacent to the plate 93 and the guide structure 77. In other words, the length of the gap 151 is greater than the length of the plate 93, which is measured in the direction perpendicular to the thickness E of the bottom wall 27. The gap 151 accommodates at least a portion of the plate 93 in the direction perpendicular to the thickness E of the bottom wall 27.

[0082] The self-supporting heat-resistant panel 43 of the secondary insulation layer 41 adjacent to the guide structure 77 partially contacts the edge of the outer portion 86 of the second plate 85. To improve insulation, a non-structural insulating filler 92 is disposed between the self-supporting heat-resistant panel 43 of the secondary insulation layer 41 adjacent to the guide structure 77 and the radial wall 88 of the lower portion 79 of the guide structure 77. A portion 97a of the outer intermediate surface 97 of the upper intermediate portion 96 of the self-supporting heat-resistant panel 43 of the secondary insulation layer 41 adjacent to the plate 93 rests on the portion of the plate 93 received in the gap 151. To at least partially compensate for manufacturing tolerances of the plate 93 and / or the self-supporting heat-resistant panel 43 of the secondary insulation layer 41 adjacent to the plate 93, a spacer 153 is arranged between the plate 93 and the portion of the outer intermediate surface 97, which rests on the portion of the plate 93 received in the gap 151. The spacer 153 is an insert or a putty bead or a combination of both. The insert may be made of plywood and / or at least one composite material.

[0083] The spacer 153 is one of the components that helps control the vertical position of the guide structure 77. In fact, it is necessary to align the outer portion 83 of the first plate 82 with the primary sealing film on the same plane. Similarly, it is necessary to align the outer portion 86 of the second plate 85 with the secondary sealing film on the same plane. The spacer 153 participates in this function.

[0084] Reference Figure 4 and Figure 5The tank 21 includes at least one blocking device 155 configured to fix the guide structure 77 in at least one direction perpendicular to the thickness direction E of the bottom wall 27. The blocking device 155 described below can be independent of the fact that the insulation layer 41 includes a gap 151 defined in the thickness direction E of the bottom wall 27 by a portion 96 of the self-supporting heat-resistant panel 43 and the support structure 3, the gap 151 being configured to at least partially accommodate the base of the guide structure 77. Alternatively, the blocking device 155 described below can be tightly integrated with the insulation layer 41, which includes a gap 151 defined in the thickness direction E of the bottom wall 27 by a portion 96 of the self-supporting heat-resistant panel 43 and the support structure 3, the gap 151 being configured to at least partially accommodate the base of the guide structure 77.

[0085] A blocking device 155 is arranged on the inner surface of the inner partition wall of the double-bottom partition wall, such that the blocking device 155 is accommodated in the gap 151. The blocking device 155 is disposed between the lateral central edge 99 of the self-supporting heat-resistant panel 43 and the guide structure 77, particularly its plate 93. As described below, a plurality of blocking devices 155 are arranged around the periphery of the guide structure.

[0086] In this embodiment, the blocking device 155 includes an angle iron 157 reinforced by a plurality of reinforcing members 163. The angle iron 157 has an L-shaped profile, meaning it includes a first segment 159 and a second segment 161 perpendicular to or substantially perpendicular to the first segment 159. The first segment 159 extends in a plane including the thickness direction E of the bottom wall 27. In other words, the first segment 159 extends in a plane perpendicular to the plane in which the plate 93 extends. The second segment 161 extends in a plane perpendicular to the thickness direction E of the bottom wall 27. In other words, the second segment 161 extends in a plane parallel to the plane in which the plate 93 extends.

[0087] The first section 159 is arranged to abut against one of the peripheries of the guide structure, particularly plate 93, while the second section 161 is arranged to abut against the inner surface of the inner partition wall 13 of the double bottom partition wall 5, while extending in a direction away from the periphery of the guide structure (e.g., plate 93). Angle iron 157 is fixed to the inner surface of the inner partition wall 13 of the double bottom partition wall 5 by welding.

[0088] Each stiffener 163 has a parallelepiped shape. For each stiffener 163, one face abuts against the first segment 159, while the other face abuts against the second segment 161. The stiffeners 163 are evenly distributed along the angle iron 157. Therefore, two adjacent stiffeners 163 are spaced apart by a non-zero distance. The second segment 161 is interrupted between two adjacent stiffeners 163. In other words, the second segment 161 is formed by multiple legs. Each stiffener 163 is fixed to one leg of the first segment 159 and the second segment 161 by welding.

[0089] The tank 21 includes a plurality of blocking devices 155 that abut against each edge of the guide structure, particularly each edge of the plate 93, to secure the guide structure in all directions perpendicular to the thickness direction E of the bottom wall 27. In other words, the blocking devices 155 prevent the guide structure from moving in the directions contained in the plane in which the inner partition wall 13 of the plate 93 extends.

[0090] The blocking element 165 can be arranged against the edge of the guide structure (in particular, plate 93) and the first segment 159 of the angle iron 157 of the blocking device 155. Therefore, the blocking element 165 can eliminate any gap between the angle iron 157 and the guide structure (here, plate 93), while enhancing the mechanical strength of the guide structure. The blocking element 165 takes the form of a plate, particularly a wedge-shaped plate, characterized by an acute angle along its longitudinal edge. After the guide structure 77 is fixed to the support structure 3, and after the blocking device 155 is fixed around the guide structure (here, plate 93), the acute angle of the blocking element 165 is forcibly inserted. The blocking element 165 is welded to the first segment 159 of the blocking device 155 to prevent any vertical movement.

[0091] When the tank 21 is assembled, the blocking device 155 is located in the gap 151. Another part 97b of the outer middle surface 97 of the upper middle portion 96 of the self-supporting heat-resistant panel 43 of the secondary insulation layer 41 adjacent to the plate 93 rests on the reinforcement 163 of the blocking device 155.

[0092] To prevent any sagging of the self-supporting heat-resistant panel 43 resting on the guide structure 77 and the blocking device 155, locking members 167, 169 are arranged between the blocking device 155 and the plywood or composite material plate 98, which is positioned at the outer middle surface 97 of the upper middle portion 96 of the self-supporting heat-resistant panel 43 of the secondary insulation layer 41, thus resting on the reinforcement 163 of the blocking device 155. Figure 4 and 5In the illustrated embodiment, the first locking member 167 is a plywood insert, and the second locking member 169 is a putty bead. The putty bead 169 is one of the elements that helps to properly vertically position the self-supporting heat-resistant panel 43 and thus defines the gap 151. Therefore, the putty bead 169 ensures both the locking function and the flatness of the parts resting on it.

[0093] Note that plate 98 includes a notch 97c in which at least a first segment 159 of the blocking device 155 extends. The vertical position of the guide structure 77 varies as a function of its manufacturing tolerances, and the notch 97c prevents any mechanical interference between the blocking device 155 and the self-supporting heat-resistant panel 43, regardless of the vertical position of the plate.

[0094] The self-supporting heat-resistant panel 43 can also be prevented from drooping by creating a notch 97c in the plate 98, which is located on the outer middle surface 97 of the self-supporting heat-resistant panel 43 adjacent to the secondary insulation layer 41 of the plate 93. The notch 97c allows the vertical edge of the first segment 159 of the angle iron 157 of the blocking device 155 to be accommodated.

[0095] Figure 5 The composition of the inner partition wall 13 is also shown, which includes a metal insert 117 to which a blocking device 155 is welded. A guide structure is also placed on this metal insert 117. Here, the concrete portion of the inner partition wall 13 is designated as 116.

[0096] Figure 6 A parallelepiped-shaped transport and / or storage tank 21 is shown installed in the base structure 3 of a gravity platform 1. The gravity platform 1 is typically an offshore structure used for oil or gas extraction. These structures typically have a concrete base structure, referred to as a gravity-based structure (GBS); the term steel gravity structure (SGS) is also used for base structures made of steel, and the present invention also applies to such base structures.

[0097] Gravity platform 1 can simultaneously function as a dam, warehouse, platform for receiving liquefied equipment, and loading dock in liquefied gas (e.g., liquefied natural gas or ethane) extraction.

[0098] The wall of tank 21 includes a primary sealing membrane intended to contact the LNG contained in tank 21, a secondary sealing membrane disposed between the primary sealing membrane and the base structure 3 of gravity platform 1, and two insulating layers disposed between the primary and secondary sealing membranes and between the secondary sealing membrane and the base structure 3, respectively. Loading / unloading pipe 103, located on the top deck of methane tanker 100, can be connected to gravity platform 1 via suitable connectors to transfer LNG cargo from or to tank 21.

[0099] Figure 6 Gravity platform 1 is shown, including loading and unloading station 105, underwater pipe 107, and gravity platform 1. Loading and unloading station 105 is a fixed offshore facility, including a mobile alarm 111 and a tower 113 supporting a mobile arm 111. Mobile arm 111 carries a bundle of insulated flexible conduits 115, which can be connected to the loading / unloading pipe 103. The directional mobile arm 111 is adaptable to all methane tanker loading specifications. Connecting pipes, not shown, extend inside tower 113. Loading and unloading station 105 enables the loading and unloading of at least one tank 22 of methane carrier 100 onto and from gravity platform 1. Tank 22 of methane carrier 100 can be tanks according to the invention. Gravity platform 1 includes at least one liquefied gas tank 21 according to the invention and a connecting pipe 109 connected to loading or unloading station 105 via underwater pipe 107. The underwater pipe 107 enables the liquefied gas to be transported over long distances, such as 5 kilometers, between the loading or unloading station 105 and the gravity platform 1, allowing the methane carrier 100 to remain in a location far from the coast during loading and unloading operations. Pumps on the methane carrier 100 and / or pumps equipped on the gravity platform 1 and / or pumps equipped on the loading and unloading station 105 are used to generate the pressure required for transporting the liquefied gas.

[0100] Of course, the present invention is not limited to the examples just described, and various modifications can be made to these examples without departing from the scope of the invention. Therefore, the transport and / or storage unit may include, for example, tank 1. Such a transport and / or storage unit may be a liquefied petroleum gas tanker, barge, reliquefaction unit, gasification unit, or land-based structure, such as a land-based container.

[0101] The invention just described does indeed achieve its intended objectives and makes it possible to propose a tank comprising a guiding structure for a liquefied gas loading / unloading tower, the tank having improved thermal insulation and its mechanical strength relative to operating and accidental loads. Variations not described herein can be implemented without departing from the scope of the invention.

Claims

1. A tank (21) for transporting and / or storing liquefied gases, comprising: Support structure (3); a plurality of walls (23, 25, 27), each wall comprising, in the thickness direction (E) of the wall (23, 25, 27), at least one insulating layer (41) abutting the support structure (3) and at least one sealing membrane (71) resting on the insulating layer (41), the plurality of walls (23, 25, 27) including at least one bottom wall (27); guide structure (77), configured to receive a loading and / or unloading tower (29) for loading and / or unloading liquefied gas contained in the tank (21), the guide structure (77) being arranged abutting the support structure (3) and extending at least partially within the tank (21), the guide structure (77) including a base, the base including at least one plate (93) supporting the support structure (3). The insulation layer (41) includes at least one self-supporting heat-resistant panel (43) arranged at least partially around the guide structure (77), characterized in that the insulation layer (41) includes a gap (151) defined in the thickness direction (E) of the bottom wall (27) by a portion (96) of the self-supporting heat-resistant panel (43) and the support structure (3), the gap (151) being configured to accommodate at least a portion of a plate (93) of the guide structure (77), the plate (93) extending in the gap (151) and in a plane perpendicular to the thickness direction (E) of the bottom wall (27), the guide structure (77) being supported on a base formed at least partially by the plate (93), the plate (93) being in plane-to-plane contact with the support structure (3).

2. The tank (21) according to claim 1, wherein, The thickness (H) of the gap (151) is between 25 mm and 70 mm, including 25 mm and 70 mm.

3. The tank (21) according to claim 1 or 2, wherein, The portion (96) of the self-supporting heat-resistant panel (43) that defines the gap (151) in the thickness direction (E) comprises a plywood or composite material panel (98).

4. The tank (21) according to claim 1 or 2, wherein, The portion (97a) of the self-supporting heat-resistant panel (43) rests on the base of the guide structure (77).

5. The tank (21) according to claim 4, wherein, The spacer (153) is disposed between the base of the guide structure (77) and the portion (97a) of the self-supporting heat-resistant panel (43) resting on the base of the guide structure (77).

6. The tank (21) according to claim 5, wherein, The spacer (153) is an insert or a putty bead or a combination of both.

7. The tank (21) according to claim 1 or 2, wherein, The gap (151) is defined in a direction perpendicular to the thickness direction (E) by the edge (99) of the self-supporting heat-resistant panel (43) and the guide structure (77), the edge (99) extending between the outer surface (97) of the portion (96) of the self-supporting heat-resistant panel (43) and the inner surface of the support structure (3).

8. The tank (21) according to claim 1 or 2, wherein, The thermal insulation component (94) is disposed between the base of the guide structure (77) and the support structure (3).

9. The tank (21) according to claim 1 or 2, comprising at least one blocking device (155) received in the gap (151) and configured to fix the guide structure (77) in at least one direction perpendicular to the thickness direction (E) of the bottom wall (27).

10. The tank (21) according to claim 1 or 2, wherein, The insulation layer (41) is a secondary insulation layer, the sealing membrane (71) is a primary sealing membrane, the tank (21) includes a primary insulation layer (61) and a secondary sealing membrane (51), the secondary sealing membrane (51) abuts against the secondary insulation layer (41), the primary insulation layer (61) abuts against the secondary sealing membrane (51), and the primary sealing membrane abuts against the primary insulation layer (61).

11. A gravity platform (1) comprising a liquefied gas storage tank (21) according to any one of the preceding claims and a loading / unloading tower (29) for loading / unloading liquefied gas contained in the tank, the loading / unloading tower (29) being configured to cooperate with a guide structure (77) of the tank (21).

12. The gravity platform (1) according to claim 11, comprising a support structure (3), wherein the tank (21) is anchored to the support structure, and the support structure (3) is made of concrete.

13. A conveying system for liquefied gases, the conveying system comprising: The gravity platform (1) according to any one of claims 11 or 12 is arranged to connect a tank (21) installed in a support structure (3) of the gravity platform (1) to an insulated pipe (103, 107, 109, 115) of the ship (100), and a pump for driving liquefied gas from the tank (21) of the gravity platform (1) through the insulated pipe (103, 107, 109, 115) to the ship (100).

14. A method for loading or unloading a gravity platform (1) according to any one of claims 11 or 12, wherein, The liquefied gas is guided from the tank (21) of the gravity platform (1) to the ship (100) through insulated pipes (103, 107, 109, 115).

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