Liquefied gas storage facility with tensioned secondary membrane

Abstract

The invention relates to a liquefied gas storage facility in which a secondary thermal insulation barrier (7) of a top wall (4) comprises a first row (60) of first insulation panels (62) arranged between a rear transverse edge (49) of a loading / unloading opening (14) and a rear cofferdam wall (82); the secondary sealing membrane (9) of the top wall (4) comprises a plurality of parallel first strakes (64) between the rear transverse edge (49) and the rear cofferdam wall (82), the first strakes (64) extending in the longitudinal direction and being interrupted by the rear transverse edge (49), each first strake (64) comprising a flat central portion (65) and two raised edges (66), where the first insulating panel (62) is equipped with strake anchoring means (69, 81) for anchoring the first strake (64) to the second insulating panel (62). The flat portion (65) of each of the first strakes (64) is welded to one of the strake anchor devices (69, 81).

Description

Field of the Invention

[0001] The present invention relates to the field of liquefied gas storage facilities, which include a sealed and thermally insulated tank with a sealing membrane.

[0002] In particular, the present invention relates to the field of sealed and thermally insulated tanks for storing and / or transporting liquefied gas at low temperatures, such as a tank for transporting liquefied petroleum gas (also known as LPG) at a temperature, for example, between -50°C and 0°C, or a tank for transporting liquefied natural gas (LNG) at atmospheric pressure and a temperature of about -162°C. These tanks can be installed onshore or on floating structures. In the case of a floating structure, the tank can be used to transport liquefied gas or to receive liquefied gas as fuel for propelling the floating structure.

[0003] The storage facility can be installed onshore or on a floating structure. In the case of a floating structure, the facility can be used to transport liquefied gas or to receive liquefied gas as fuel for propelling the floating structure. Background Art

[0004] Document KR20200144697 describes a liquefied gas storage facility, which includes a tank incorporated in a support structure member of a transport vehicle. The wall of the tank has a multi-layer structure, which, from the outside to the inside in the thickness direction, sequentially includes: a secondary thermal insulation barrier held on the support structure member, a secondary sealing membrane attached to the secondary thermal insulation barrier, a primary thermal insulation barrier attached to the secondary thermal insulation barrier through the secondary sealing membrane, and a primary sealing membrane attached to the primary thermal insulation barrier and used to contact the liquefied gas stored in the tank. The secondary sealing membrane includes a plurality of parallel column plates. Each column plate includes a flat central portion extending in the longitudinal direction of the tank and two raised edges provided on both sides of the flat central portion and protruding towards the inside of the tank relative to the central portion. Different from a corrugated membrane, this secondary sealing membrane, usually called a "tension membrane", cannot absorb the tension and compression forces in the longitudinal direction.

[0005] The top wall of the tank is interrupted at the loading / unloading opening, and a pipeline for loading and / or unloading liquefied gas passes through the loading / unloading opening. The secondary sealing membrane is stopped and directly connected to the support structure member by means of a secondary connection bracket to absorb the tensile and compressive forces, which are particularly caused by the thermal shrinkage of the secondary sealing membrane and the deformation of the transport vehicle shell related to the deflection of the transport vehicle beam. To relieve the burden on the secondary connection bracket, the secondary thermal insulation barrier has a specific arrangement structure along the front transverse edge of the loading / unloading opening, which particularly includes a plurality of secondary attachment supports made of metal and attached with secondary stop beams, and one of the secondary connection brackets is arranged against the secondary stop beam.

[0006] The rear lateral edge of the loading / unloading opening is positioned relatively close to the rear cofferdam wall of the tank. Accordingly, the force exerted on the secondary connection bracket positioned along the rear lateral edge is less than the force exerted on the secondary connection bracket provided along the front lateral edge. In addition, the secondary thermal insulation barrier does not have such a specific arrangement structure including a secondary stop beam and a secondary attachment support on the rear lateral edge. Further, in the region behind the loading / unloading opening, on the one hand, only the end of the strake is attached to the mechanically welded structural member along the rear cofferdam wall, and on the other hand, only the end of the strake is attached to the connection bracket along the rear lateral edge of the loading / unloading opening.

[0007] This arrangement is not entirely satisfactory, particularly because the fact that the strake between the mechanically welded structural member and the secondary connection bracket is not attached is likely to cause the strake to be torn, especially when the strake is subjected to excessive pressure in the secondary thermal insulation barrier. SUMMARY OF THE INVENTION

[0008] The idea underlying the present invention is to provide a liquefied gas storage facility of the above type that is more robust in the region located between the loading / unloading opening and the rear cofferdam wall.

[0009] According to a first aspect, the present invention provides a liquefied gas storage facility including a support structure and a sealed and thermally insulated tank supported by the support structure. The support structure includes an upper support wall, and the tank includes a top wall attached to the upper support wall. The top wall includes, in a thickness direction from the outside to the inside of the tank: a secondary thermal insulation barrier attached to the upper support wall, a secondary sealing film disposed against the secondary thermal insulation barrier, a primary thermal insulation barrier disposed against the secondary sealing film, and a primary sealing film disposed against the primary thermal insulation barrier and adapted to be in contact with the liquefied gas. The top wall is locally interrupted to define a loading / unloading opening for allowing a loading / unloading pipe to pass through the loading / unloading opening. The loading / unloading opening is defined by a front lateral edge and a rear lateral edge parallel to the lateral direction and a first longitudinal edge and a second longitudinal edge parallel to the longitudinal direction perpendicular to the lateral direction.

[0010] The secondary thermal insulation barrier of the top wall includes a first row of first insulation panels aligned in the lateral direction and disposed between the rear lateral edge and the rear cofferdam wall.

[0011] The secondary sealing film of the top wall includes a plurality of parallel first battens between the rear transverse edge and the rear cofferdam wall. The first battens extend in the longitudinal direction and are interrupted by the rear transverse edge. Each first batten includes a flat central portion disposed against the first insulating panel and two raised edges protruding towards the interior of the tank relative to the central portion. The first battens are juxtaposed in the transverse direction according to a repeating pattern and are hermetically welded together at the raised edges.

[0012] Wherein, the first insulating panel is equipped with batten anchoring means, and the flat portion of each first batten in the first battens is welded to one of the batten anchoring means in the batten anchoring means.

[0013] Therefore, by means of the batten anchoring means, in the area between the rear cofferdam wall and the loading / unloading opening, the battens of the secondary film are properly anchored, which makes it possible to prevent the battens from being torn when the pressure in the secondary thermal insulation barrier is too high.

[0014] According to an embodiment, such a facility may include one or more of the following features.

[0015] According to an embodiment, each first insulating panel is equipped with a single batten anchoring means. When the first insulating panel shrinks during tank cooling, this can limit the stress in the secondary sealing film.

[0016] According to an embodiment, each batten anchoring means is disposed in the middle of the corresponding first insulating panel in the transverse direction.

[0017] According to an embodiment, the batten anchoring means is disposed in the middle of the corresponding first insulating panel in the longitudinal direction.

[0018] According to an embodiment, the batten anchoring means is disposed in the middle of the batten in the transverse direction.

[0019] According to an embodiment, the first insulating panel has a transverse dimension equal to the transverse dimension of the first batten, and each of the first insulating panels is aligned with one of the first battens such that the raised edges of the first battens are positioned to align with the gaps between two adjacent first insulating panels.

[0020] According to an embodiment, the first insulating panel does not have a welding support for attaching the raised edges of the battens to the first insulating panel. In other words, in the area of the first insulating panel, the raised edges of the first battens are directly welded to each other.

[0021] According to an embodiment, each batten anchoring means includes:

[0022] - a plate member attached to one of the first insulating panels in the first insulating panel,

[0023] - A pin, which is attached to the plate member and extends from the plate member in the thickness direction of the top wall towards the interior of the tank, and the pin seals through a hole in a flat portion of one of the first row of plates in the first row of plates; the pin includes a flange that is sealingly attached to the first row of plates around the hole. This type of plate anchoring device is advantageous because it is simple in terms of setting the plate anchoring device in place and use.

[0024] According to an embodiment, the secondary thermal insulation barrier of the top wall includes a second row of second insulation panels, which are aligned in the transverse direction and are arranged between the first row of first insulation panels and the rear weir wall.

[0025] According to an embodiment, the second insulation panels are equipped with plate anchoring devices, and the flat portions of at least some of the first row of plates in the first row of plates are welded to one of the plate anchoring devices in the plate anchoring devices of the second insulation panels.

[0026] According to an embodiment, none of the second insulation panels has a groove for receiving the following welding support member: one of the raised edges of two adjacent first row of plates is welded to the welding support member.

[0027] According to an embodiment, the first row of plates is welded to a secondary connection bracket connected to the upper support wall along the rear transverse edge.

[0028] According to an embodiment, the secondary thermal insulation barrier of the top wall includes:

[0029] - At least a first secondary attachment support member and a second secondary attachment support member positioned along the rear transverse edge; each of the first secondary attachment support member and the second secondary attachment support member includes: a secondary base that is anchored to the upper support wall; a secondary cap that is welded to the secondary base and extends in a plane parallel to the upper support wall in a direction parallel to the longitudinal direction; and a plate member attached to the secondary cap via an attachment member;

[0030] - At least one boundary secondary insulation block disposed between the first secondary attachment support member and the second secondary attachment support member along the first transverse edge; and

[0031] - At least one secondary stop beam extending along the rear transverse edge and disposed at least against the secondary caps of each of the first secondary attachment support member and the second secondary attachment support member and against one of the boundary secondary insulation blocks, the secondary stop beam being fixed between the plate member and the secondary caps of each of the first secondary attachment support member and the second secondary attachment support member in the thickness direction of the top wall;

[0032] The secondary connection bracket includes a first wing portion disposed against the secondary stop beam and a second wing portion connected to the upper support wall.

[0033] Thus, the arrangement of the secondary thermal insulation barrier along the rear edge enables the burden on the corresponding secondary connection bracket to be alleviated. This allows the loading / unloading opening to be moved further away from the rear cofferdam wall without the risk of the secondary connection brackets provided along the rear transverse edge being subjected to excessive forces.

[0034] According to an embodiment, the first and second secondary attachment supports are used to support the primary anchoring means for anchoring the primary thermal insulation barrier, and some of the panel anchoring means provided in the first insulation panel are aligned with the primary anchoring means in the longitudinal direction L.

[0035] According to an embodiment, the primary thermal insulation barrier of the top wall includes, in the region located between the rear cofferdam wall and the rear transverse edge, the following primary insulation panel: the primary insulation panel is arranged to straddle the secondary stop beam and the insulating element of the corner structure, and the corner structure is provided at the joint between the top wall and the rear cofferdam wall. This makes it possible to prevent or at least limit the step phenomenon in the primary seal film support surface.

[0036] According to an embodiment, the primary insulation panel located in the region positioned between the rear cofferdam wall and the rear transverse edge includes recesses for receiving the panel anchoring means.

[0037] According to an embodiment, the first panel is welded to a mechanically welded structural member that extends along the edge where the top wall meets the rear cofferdam wall and is attached to the top wall and the rear cofferdam wall.

[0038] The facility according to one of the above embodiments may be an onshore storage facility, such as a storage facility for storing liquefied natural gas, or the facility may be installed on a floating structure, coastal or deep - water, especially a means of transportation for liquefied natural gas or ethane, a floating storage and regasification unit (FSRU), a remote floating production and storage unit (FPSO), etc. In the case of a floating structure, the tank can be used to receive liquefied natural gas used as fuel for propelling the floating structure.

[0039] According to an embodiment, the present invention relates to a means of transportation for transporting fluids, which includes a facility of the above type.

[0040] According to an embodiment, the means of transportation includes a double - hull forming a support structure.

[0041] According to an embodiment, the present invention further provides a system for transporting a fluid, the system comprising a transportation vehicle as described above, an isolation pipeline configured to connect the tank of the transportation vehicle to a floating storage facility or an onshore storage facility, and a pump for pumping a fluid stream from the floating storage facility or the onshore storage facility to the tank of the transportation vehicle or from the tank of the transportation vehicle to the floating storage facility or the onshore storage facility via the isolation pipeline.

[0042] According to an embodiment, the present invention further provides a method for loading or unloading such a transportation vehicle, wherein a fluid is transported from a floating storage facility or an onshore storage facility to the tank of the transportation vehicle via an isolation pipeline, or a fluid is transported from the tank of the transportation vehicle to the floating storage facility or the onshore storage facility via the isolation pipeline.

[0043] According to a second aspect, which may be implemented independently of the first aspect, the present invention relates to a liquefied gas storage facility, the liquefied gas storage facility comprising a support structure and a sealed and thermally insulated tank supported by the support structure, the support structure comprising an upper support wall, and the tank comprising a top wall attached to the upper support wall, the top wall comprising, in a thickness direction from the outside to the inside of the tank: a secondary thermal insulation barrier attached to the upper support wall; a secondary sealing film disposed against the secondary thermal insulation barrier; a primary thermal insulation barrier disposed against the secondary sealing film; and a primary sealing film disposed against the primary thermal insulation barrier and configured to contact the liquefied gas, the top wall being locally interrupted to define a loading / unloading opening for allowing a loading / unloading pipeline to pass through the loading / unloading opening, the loading / unloading opening being defined by a front transverse edge and a rear transverse edge parallel to the transverse direction and a first longitudinal edge and a second longitudinal edge parallel to the longitudinal direction perpendicular to the transverse direction;

[0044] The secondary thermal insulation barrier of the top wall comprises:

[0045] - at least a first secondary attachment support and a second secondary attachment support positioned along the rear transverse edge; each of the first secondary attachment support and the second secondary attachment support comprising: a secondary base anchored to the upper support wall; a secondary cap welded to the secondary base and extending in a plane parallel to the upper support wall in a direction parallel to the longitudinal direction; and a plate member attached to the secondary cap via an attachment member;

[0046] - at least one boundary secondary insulation block disposed between the first secondary attachment support and the second secondary attachment support along the first transverse edge; and

[0047] - At least one secondary stop beam, which extends along the rear transverse edge and is arranged against the secondary caps of each of the first secondary attachment support and the second secondary attachment support and against one of the boundary secondary isolation blocks of the boundary secondary isolation blocks, and the secondary stop beam is fixed between the plate member and the secondary caps of each of the first secondary attachment support and the second secondary attachment support in the thickness direction of the top wall.

[0048] Therefore, the arrangement structure of the secondary thermal isolation barrier along the rear edge enables the burden on the corresponding secondary connection brackets to be reduced. This allows the loading / unloading opening to be moved further away from the rear cofferdam wall without the risk of the secondary connection brackets arranged along the rear transverse edge being subjected to excessive forces. Brief Description of the Drawings

[0049] The present invention can be better understood by the following description of multiple specific embodiments provided by way of non-limiting examples with reference to the accompanying drawings, and other objects, details, features and advantages of the present invention will become more clearly apparent.

[0050] Figure 1 is a schematic view of a transport vehicle including a storage facility.

[0051] Figure 2 is a partial view of the area near the loading / unloading opening where the top wall of the tank is interrupted, observed from below the top wall according to the first embodiment, and the view corresponds to Figure 1 detail II in

[0052] Figure 3 is a longitudinal sectional view of the top wall near the rear cofferdam wall.

[0053] Figure 4 is a partial perspective view of the secondary thermal isolation barrier along the rear transverse edge of the loading / unloading opening.

[0054] Figure 5 is a perspective view of the secondary attachment support.

[0055] Figure 6 is a partial transverse view of the secondary thermal isolation barrier along the rear transverse edge of the loading / unloading opening.

[0056] Figure 7 is a perspective view of the beam arranged against the secondary attachment support.

[0057] Figure 8 is a partial perspective view of the top wall between the rear transverse edge of the loading / unloading opening and the rear cofferdam wall, showing the arrangement structure of the secondary thermal isolation barrier and the secondary sealing film in this area.

[0058] Figure 9Partial perspective view of the secondary thermal insulation barrier of the top wall between the rear lateral edge of the loading / unloading opening and the rear cofferdam wall.

[0059] Figure 10 Depicts a device for anchoring a strake according to an embodiment.

[0060] Figure 11 Depicts a device for anchoring a strake, which also has the function of anchoring a primary panel.

[0061] Figure 12 Schematically depicts, in a partially cut-away manner, the tank of an LNG carrier and a terminal for loading / unloading the tank. Detailed Description

[0062] By convention, the terms "outer" and "inner" are used to define the relative position of one element with respect to another by reference to the outside and inside of the tank. Further, in the drawings, the arrows L and T respectively correspond to the longitudinal and transverse directions of the tank that are perpendicular to each other. Additionally, in the illustrated embodiments, the arrows L and T also correspond to the longitudinal and transverse directions of the carrier, since in these embodiments the tank has the same orientation as the carrier.

[0063] Figure 1 Shows a carrier 70 for the storage and transportation of liquefied gas, the carrier 70 being, for example, an LNG carrier. The carrier 70 includes a storage facility 1, and the storage facility 1 includes a plurality of tanks 71 disposed in the inner hull of the carrier. To this end, the inner hull has a plurality of polyhedral-shaped chambers defined by a plurality of support walls, and each of these chambers is for forming a support structure for receiving one of the tanks 71 of the carrier 1. The inner hull includes cofferdam support walls that extend transversely to the longitudinal direction L of the carrier and define a cofferdam space that divides the inner hull into a plurality of chambers.

[0064] Each tank 71 has a polyhedral shape and includes a plurality of tank walls that are assembled to each other and fastened against the support walls. In particular, the tank includes a top wall 4, a rear cofferdam wall 82, and a front cofferdam wall 83. The front cofferdam wall 83 and the rear cofferdam wall 82 are spaced apart in the longitudinal direction L of the carrier 70 and are fastened against one of the two cofferdam support walls and the other cofferdam support wall.

[0065] In order to load liquefied gas into the tank / unload liquefied gas from the tank, an opening is formed in the top wall 4 at Figure 1Loading / unloading openings not shown in the figure, through which pipelines for loading and / or unloading liquefied gas pass. The loading / unloading openings are formed in the top wall 4 near the rear cofferdam wall 82 ( Figure 1 in zone II of

[0066] The upper support wall of the support structure member 2 also has holes that allow the pipelines to pass through the support structure member 2. The loading / unloading openings serve as the entry points for various devices for processing liquefied natural gas, and in particular are the entry points for one or more of the following devices: filling pipelines, emergency pumping pipelines, unloading pipelines connected to unloading pumps, spraying pipelines, supply pipelines connected to spraying pumps, etc. According to an embodiment, a loading / unloading tower not shown passes through the loading / unloading openings. The loading tower has vertical masts attached to each other by crossbars. The vertical masts are hollow and thus each vertical mast defines a loading pipeline, a loading pipeline, or a decompression well to allow the descent of the decompression well.

[0067] Figure 2 A perspective view of the area of the top wall 4 near the loading / unloading opening 14 as viewed from the inside of the tank is shown. The loading / unloading opening 14 has a rectangular shape and is defined by two longitudinal edges 5 and two transverse edges, the two longitudinal edges 5 being parallel to the longitudinal direction L of the tank, and the two transverse edges being a front transverse edge 6 and a rear transverse edge 49 and being parallel to the transverse direction.

[0068] Figure 3 The multi-layer structure of the top wall 4 is shown. The top wall 4 includes, in the thickness direction from the outside to the inside of the tank, in sequence: a secondary thermal insulation barrier 7 held on the upper support wall 8, a secondary sealing film 9 supported against the secondary thermal insulation barrier 7, a primary thermal insulation barrier 10 supported against the secondary sealing film 9, and a primary sealing film 11 supported against the primary thermal insulation barrier 10 and used to contact the liquefied natural gas contained in the tank.

[0069] The secondary thermal insulation barrier 7 includes a plurality of secondary insulation panels 12, which are anchored to the upper support wall 8 by Figure 3 secondary anchoring devices not shown in the figure or by bonding with mastic. The secondary insulation panels 12 have a generally parallelepiped shape and are arranged, for example, in parallel rows along the longitudinal direction L and the transverse direction T.

[0070] The secondary sealing film 9 of the top wall 4 includes a continuous layer of metal battens having raised edges. Each batten extends along the longitudinal direction L and includes a flat central portion that rests on the secondary insulation panel 12. Each batten also includes two raised edges that are provided on both sides of the flat central portion and project towards the interior of the tank relative to the central portion. Except for the battens with different anchoring methods that are positioned behind the loading / unloading opening 14 of the top wall 4, the battens are welded to parallel welding supports by the raised edges of the battens, and the welding supports are attached to grooves formed in the inner surface of the secondary insulation panel, that is, attached to the grooves of the surface of the secondary insulation panel that contacts the secondary sealing film 9. For example, the battens are made of made of, in other words, made of an iron-nickel alloy, and the expansion coefficient of the iron-nickel alloy is generally between 1.2×10 -6 K -1 and 2×10 -6 K -1 or the battens are made of an iron-manganese alloy, and the expansion coefficient of the iron-manganese alloy is generally between 7×10 -6 K -1 and 9×10 -6 K -1 between.

[0071] The primary thermal insulation barrier 10 includes a plurality of primary insulation panels 13, and these primary insulation panels are anchored to the secondary insulation panel 12 by primary anchoring means (not shown in Figure 3 either). The primary insulation panel 13 has a generally parallelepiped shape. The primary insulation panel 13 can be particularly positioned to be offset relative to the secondary insulation panel 12 in the longitudinal direction L, and optionally, the primary insulation panel 13 can be particularly positioned to be offset relative to the secondary insulation panel 12 in the transverse direction T as well.

[0072] According to an embodiment, the secondary insulation panel 12 and the primary insulation panel 13 include a bottom plate, a cover plate, and one or more layers of insulating polymer foam, and the insulating polymer foam is sandwiched between the bottom plate and the cover plate and adhesively bonded to the bottom plate and the cover plate. The insulating polymer foam can be particularly a polyurethane-based foam, optionally a fiber-reinforced foam, especially a glass fiber-reinforced foam.

[0073] The primary sealing film 11 includes a plurality of corrugated metal plates, and the plurality of corrugated metal plates are juxtaposed along the longitudinal direction L and the transverse direction T and welded to each other along the edges of the corrugated metal plates. The primary sealing film 11 includes corrugated portions extending parallel to the longitudinal direction L and corrugated portions extending parallel to the transverse direction T.

[0074] To define the loading / unloading opening 14, the top wall 4 is locally interrupted. Accordingly, the sealing film and the thermal insulation barrier are interrupted around the loading / unloading opening 14, the sealing film being the primary sealing film 11 and the secondary sealing film 9, and the thermal insulation barrier being the primary thermal insulation barrier 10 and the secondary thermal insulation barrier 7.

[0075] Returning Figure 2 , Figure 2 shows a cover 15 provided in the loading / unloading opening 14. The cover 15 includes a metal sealing wall 16 and a thermal insulation structure 17 located between the metal sealing wall 16 and the upper support wall 8. The cover 15 is attached to the upper support wall 8. The metal sealing wall 16 provides sealing continuity with the primary sealing film 11 of the top wall 4, while the thermal insulation structure 17 provides insulation continuity.

[0076] The thermal insulation structure 17 may include one or more cover thermal insulation blocks, which are made, for example, in the form of a box-shaped member including a bottom plate, a cover plate, and support spacers extending in the thickness direction between the bottom plate and the cover plate, and the box-shaped member defines a plurality of chambers filled with insulating filler, the insulating filler being, for example, perlite, glass wool, or rock wool. The cover insulation block includes holes (not shown) to allow the loading / unloading pipe to pass through.

[0077] The metal sealing wall 16 of the cover 15 includes, for example, a plurality of metal plates welded to each other. In addition, the metal sealing wall 16 includes a plurality of cover holes (not shown) for the loading / unloading pipe to pass through. The metal connection strip 18 enables the metal sealing wall 16 of the cover 15 to be sealingly connected to the primary sealing film 11 of the top wall 4, as Figure 2 shown.

[0078] Although the primary sealing film 11 is connected to the metal sealing wall 16 of the cover 15 at the loading / unloading opening 14, the secondary sealing film 9 is interrupted by itself at the longitudinal edge 5 and the transverse edge 6, 49 of the loading / unloading opening 14 and is directly sealingly connected to the upper support wall 8. This connection is achieved by means of a secondary connection bracket 19, which can be seen, in particular, in Figure 3 . The secondary connection bracket 19 includes a first wing 20 and a second wing 21 connected to the first wing 20. The first wing 20 extends in a horizontal plane and is connected to the secondary sealing film 9, while the second wing 21 extends in a vertical plane and is welded to the anchoring plane area 22 of the upper support wall 8. Accordingly, some of the planks of the secondary sealing film 9 are interrupted by the loading / unloading opening 14 and are connected to the upper support wall 8.

[0079] At the connection with the upper support wall 8, the secondary sealing film 9 can transfer the tension associated with the function of the secondary sealing film 9 to the secondary connection bracket 19. In particular, when the tank is cooled, the secondary sealing film 9 can transfer the tension associated with the function of the secondary sealing film 9 to the secondary connection bracket 19. In addition, in order to relieve the burden on the secondary connection bracket 19 and the welded part between the secondary connection bracket 19 and the secondary sealing film 9, the secondary thermal insulation barrier 7 has a specific arrangement structure along the front lateral edge 6 and the rear lateral edge 49 of the loading / unloading opening 14.

[0080] Figure 4 Partially shown is the specific arrangement structure of the secondary thermal insulation barrier 7 along the lateral edge, which in this case is the lateral edge 49. The secondary thermal insulation barrier 7 includes a plurality of secondary attachment supports 23, which are regularly distributed along the rear lateral edge 49 of the loading / unloading opening 14, and these secondary attachment supports 23 are spaced apart from each other in the lateral direction T and welded to the upper support wall 8.

[0081] Figure 5 Shown is one of the secondary attachment supports 23. The secondary attachment support includes a secondary cap 24, which extends in a plane parallel to the top wall 4 in a manner parallel to the longitudinal direction. The secondary cap 24 is welded to the secondary base 25, which is anchored to the upper support wall 8, for example, the secondary base 25 is anchored to the upper support wall 8 by welding. The secondary base 25 includes two branches 26, 27, and the two branches 26, 27 are connected to each other by a central web 28. The two branches 26, 27 are welded to the two ends of the secondary cap 24 and extend parallel to each other in a plane parallel to the lateral direction and the thickness direction of the top wall 4. The central web 28, for its part, extends in a plane parallel to the longitudinal direction and the thickness direction of the top wall 4. The central web 28 is welded to the secondary cap 24 and the two branches 26, 27. In the illustrated embodiment, the central web 28 has a U-shaped configuration. The spacing between the two branches 26, 27 in the longitudinal direction L defines the base length and enables resistance to the swaying and bending of the secondary connection bracket 19 in this direction.

[0082] The secondary attachment support 23 supports primary fixing means 29 for anchoring the primary thermal insulation barrier 10. The primary anchoring means 29 is attached to a plate member 30, and the plate member 30 itself is attached to the secondary cap 24 by an attachment member 31, such as a screw. The longitudinal direction of the plate member 30 is parallel to the longitudinal direction of the tank.

[0083] In addition, a threaded shank 32 is attached to the plate member 30 and extends towards the interior of the can in the thickness direction. The threaded shank 32 is used to sealably pass through a hole formed in the secondary sealing film 9. The primary anchoring device 29 further includes a support element 33 which is supported against a support area of the boundary primary insulation block 51 of the primary thermal insulation barrier 10, particularly as Figure 3 shown, the support area being provided along the lateral edges 6, 49 of the loading / unloading opening 14. In the illustrated embodiment, the support area of the boundary primary insulation block 51 is formed, for example, by a strip attached to the end of the boundary primary insulation block 51.

[0084] In addition, the primary anchoring device 25 further includes a nut 34, particularly visible in Figure 5 which interacts with the threaded portion of the threaded shank 32 to attach the support element 33 together with the Belleville washer 35 to the threaded shank 32, the Belleville washer 35 being mounted on the threaded shank 32 between the nut 34 and the support element 33. In addition, the primary anchoring device 25 includes a flange 36 which is positioned around the threaded shank 32 and is used to be sealably welded to the secondary sealing film 9 completely around the hole through which the threaded shank 32 passes.

[0085] Returning to Figure 4 , it can be seen that the secondary thermal insulation barrier 7 also includes boundary secondary insulation blocks 37 along the lateral edges 6, 49. Each boundary secondary insulation block 37 is placed between two adjacent secondary attachment supports 23. The boundary secondary insulation blocks 37 are advantageously adhesively bonded to the upper support wall 8. For example, the boundary secondary insulation blocks 37 are advantageously adhesively bonded to the upper support wall 8 by means of mastic. The boundary secondary insulation blocks 37 are formed, for example, by wooden box-shaped members with insulating fillers such as perlite, glass wool or rock wool placed inside.

[0086] The secondary thermal insulation barrier 7 further includes a secondary stop beam 38 against which the first wing 20 of the secondary connection bracket 19 is attached. The secondary stop beam 38 is made of wood, for example. The secondary stop beam 38 also helps to hold the boundary secondary insulation blocks 37 on the upper support wall 8. Thus, the secondary stop beam 38 is placed in the thickness direction between the boundary secondary insulation blocks 37 and the first wing 20 of the secondary connection bracket 19.

[0087] The secondary stop beams 38 are each attached by straddling two secondary attachment supports 23. In the illustrated embodiment, the secondary stop beams 38 also rest on the secondary attachment supports 23 at their middle portions. To attach the secondary stop beams 38, the ends of the secondary stop beams 38 are clamped between the plate member 30 and the secondary cap 24. Since the attachment member 31 is adjustable, the ends of the secondary stop beams 38 are fixed between the plate member 30 and the secondary cap 24 in the thickness direction of the top wall.

[0088] As Figure 7 shown, the secondary stop beam 38 has a recess 39 in which the plate member 30 is received such that the plate member 30 is substantially flush with the inner surface of the secondary stop beam 38. This makes it possible to ensure the flatness of the support surface against which the first wing 20 of the secondary connection bracket 19 abuts and the secondary sealing film 9.

[0089] Advantageously, the secondary stop beam 38 further includes one or more prefabricated metal reinforcements, whereby the stiffness of the secondary stop beam 38 can be increased. The metal reinforcement is, for example, a metal reinforcement strip 40, which is oriented parallel to the length of the secondary stop beam 38, in other words, the metal reinforcement strip 40 is oriented parallel to the lateral direction of the tank. The metal reinforcement 48 can be attached to the secondary stop beam 38 in any manner, in particular, the metal reinforcement 48 can be attached to the secondary stop beam 38 by fixing screws, by bonding or riveting.

[0090] According to an advantageous embodiment, a bead or strip of mastic, not shown, is positioned between the secondary stop beam 38 and the boundary secondary isolation block 37 and / or the secondary cap 24 of the secondary attachment support 23. This makes it possible to adjust the position of the secondary stop beam 38 in the thickness direction of the top wall 4.

[0091] As Figure 7 shown, the secondary stop beam 38 further includes a support bracket 41 in the shape of an L and made of metal, which serves as a support for a stop device 42, which, in particular, Figures 4 to 6Visible and will be described hereinafter. Since the support brackets 41 are harder than the secondary stop beam 38, the secondary stop beam 38 can be prevented from denting in the area where the secondary stop beam contacts the stop device 42. In addition, the secondary stop beam 38 has a notch 43, which allows the stop device 42 to be received when the secondary stop beam 38 is placed in position against the secondary attachment support 23. Each of the support brackets 41 has: a first tab 44 positioned against the outer surface portion of the secondary stop beam 38; and a second tab 45 positioned against the edge of one of the notches 43. The support brackets 41 can be attached to the secondary stop beam 38 in any manner, in particular, the support brackets 41 are attached to the secondary stop beam 38 by fixing screws, by bonding or riveting. Advantageously, the first tab 44 is embedded in a recess formed in the inner surface of the secondary stop beam 38.

[0092] In addition, as Figure 6 shown, the translation of each secondary stop beam 38 in the longitudinal direction L is blocked by the secondary attachment support 23 that interacts with the secondary stop beam. For this purpose, each secondary attachment support 23 includes a stop device 42 attached to the secondary cap 24. The stop device 42 includes a plate 43 that is attached perpendicular to the secondary cap 24 by welding. In the illustrated embodiment, in order to strengthen the rigidity of the stop device 42, a reinforcing member in the form of gusset plate 46 is welded between the plate 43 and the secondary cap 24. The plate 43 includes two threaded holes, the axes of the threaded holes are oriented parallel to the longitudinal direction L of the tank, and each threaded hole has a fixing screw 44 passing through the threaded hole. Each fixing screw 44 is used to bear against one of the support brackets 41, which has the effect of pressing the corresponding secondary stop beam 38 against the end 45 of the branch portion 27, so that the translation of the secondary stop beam 38 in the longitudinal direction L can be blocked.

[0093] Therefore, the secondary stop beam 38 is rigidly supported by the secondary attachment support 23 in both the longitudinal direction L and the thickness direction of the top wall 4, which enables it to withstand the tensile or compressive forces that the secondary sealing film 9 may exert during operation.

[0094] As Figure 4 shown, the secondary thermal insulation barrier 7 includes a cover plate 47, which is received in a ledge formed in the secondary stop beam 38 and covers the notch 43 that receives the stop device 42. The cover plate 47 ensures that the support surface of the secondary sealing film 9 is flat.

[0095] Referring to Figure 3 、 Figure 8 and Figure 9, the secondary thermal insulation barrier 7 and the secondary sealing film 9 in the region of the top wall 4 located between the rear cofferdam wall 82 and the rear lateral edge 49 of the loading / unloading opening 14 will now be described.

[0096] A corner structure 50 is provided at the corner portion at the joint between the top wall 4 and the rear cofferdam wall 82.

[0097] As Figure 2 and Figure 8 shown, the corner structure 50 includes an X-shaped mechanically welded structural member 51, and the mechanically welded structural member 51 extends in a manner parallel to the edge where the top wall 4 and the rear cofferdam wall 82 meet. The mechanically welded structural member includes two wings 52, 53 perpendicular to each other, and the two wings are respectively parallel to one of the top wall 4 and the rear cofferdam wall 82. Each of the wings 52, 53 is welded to the anchoring flat areas 54, 55 protruding from the upper support wall 8 or the rear support wall 56.

[0098] The corner structure 50 of the secondary thermal insulation barrier 7 further includes insulation elements 57 and insulation elements 58, 59. The insulation element 57 is disposed in the region located between the upper support wall 8, the rear support wall 56 and the two wings 52, 53 of the mechanically welded structural member 51, and the insulation elements 58, 59 are disposed in each region defined between one of the wings 52, 53 of the mechanically welded structural member 51 and one of the upper support wall 8 and the rear support wall 56.

[0099] As Figure 9 shown, the secondary thermal insulation barrier further includes two rows of insulation panels aligned in the lateral direction between the corner structure 50 and the arrangement structure provided along the rear lateral edge 49 of the loading / unloading opening 14. As a convention, the row of insulation panels closest to the rear lateral edge 49 of the loading / unloading opening 14 will be referred to as the "first row 60", and the insulation panels in the "first row 60" will be referred to as "first insulation panels 62", while the row of insulation panels closest to the rear cofferdam wall 82 will be referred to as the "second row 61", and the insulation panels in the "second row 61" will be referred to as "second insulation panels 63".

[0100] The secondary sealing film 9 includes a plurality of gussets 64 visible in Figure 8 in the region provided between the corner structure 50 and the rear lateral edge 49 of the loading / unloading opening 14. These gussets extend in the longitudinal direction and are interrupted by the rear lateral edge 49. Each of the gussets 64 is attached to one of the wings 53 of the mechanically welded structural member 51 on one hand and to the secondary connecting bracket 19 extending along the rear lateral edge 49 on the other hand.

[0101] The gusset plate 64 includes a flat central portion 65 and two raised edges 66. The central portion 65 rests on the first insulating panel 62 and the second insulating panel 63. The two raised edges are provided on both sides of the central portion 65 and project towards the inside of the tank relative to the central portion 65.

[0102] The gusset plates 64 are welded to each other through the raised edges 66 of the gusset plates. However, in this area, the raised edges 66 of the gusset plates 64 are not welded to the welding support. Figure 9 In the illustrated embodiment, each of the second insulating panels 63 supports three gusset plates 64: one gusset plate is provided at the central portion of the second insulating panel 63, and the other two gusset plates are respectively arranged transversely on both sides of the gusset plate 64 and straddle one of the second insulating panel 63 and the adjacent second insulating panel 63.

[0103] The first insulating panel 62 also has no welding support.

[0104] Therefore, in the area between the corner structure 50 and the arrangement structure located along the rear transverse edge 49 of the loading / unloading opening 14, the gusset plates 64 are not anchored to the welding support through the raised edges 66 of the gusset plates. In addition, in order to anchor the gusset plates 64 to these first insulating panels 62 to prevent the gusset plates 64 from being torn in the case of excessive pressure in the secondary thermal insulation barrier 7, the first insulating panels 62 are equipped with gusset plate anchoring devices 69, 81, and each central portion 65 in the central portion of the gusset plates 64 is welded to the gusset plate anchoring devices 69, 81. This makes it possible to simplify the method of anchoring the gusset plates 64 in this area, and also to simplify the process of sealingly welding the gusset plates 64 to each other by avoiding the use of complex welding. This complex welding that is avoided cannot be completed by a welding machine like in other areas of the membrane anyway due to the too short length of the gusset plates in this area.

[0105] In the illustrated embodiment, there are two types of gusset plate anchoring devices. One is marked 69 and is shown in Figure 10 This type of gusset plate anchoring device is only used for anchoring the gusset plates, while the other is marked 81 and is shown in Figure 11 This type of gusset plate anchoring device has a dual function because this type of gusset plate anchoring device is also used for anchoring the primary insulating panel.

[0106] The gusset plate anchoring device 69 includes a pin 85, which is used to pass through a hole formed in the central portion 65 of one of the gusset plates 64. The pin 85 includes a threaded end (not shown), which is used to be screwed into a threaded hole in a plate made of metal (also not shown). The plate is received in a recess formed in the inner surface of the first insulating panel 62 and attached to the recess.

[0107] In addition, the pin 85 includes a flange 86 that extends radially with respect to the axis of the pin 85. When the pin 85 is screwed into a threaded hole in a plate member of a first isolation panel 62 attached to one of the first isolation panels, the flange 86 is used to press against the central portion 65 of the column plate 64. In addition, the flange 86 is hermetically welded to the central portion 65 of the column plate 64 completely around the hole, which makes it possible to ensure that the pin 85 passes through the secondary sealing film 9 in a sealed manner.

[0108] Figure 11 The column plate anchoring device 81 shown in includes a structure similar to that of the Figure 10 column plate anchoring device in, but also includes a handle 87 for attaching the primary isolation panel 13. For this purpose, the handle 87 projects into a recess formed in the primary isolation panel 13. In addition, a support plate (not shown) has a hole threadedly connected to the handle and a nut (also not shown) that interacts with the threaded end of the handle to attach the support plate to the handle. The support plate is supported against a support surface in one of the recesses formed in the recess of the primary isolation panel 13, thereby holding the support plate towards the support structure. In addition, according to an advantageous embodiment, a Belleville washer is threadedly connected to the handle 87 between the nut and the support plate, which makes it possible to elastically anchor the primary panel to the secondary thermal insulation barrier.

[0109] In addition, returning to Figure 8 and Figure 9 , it can be seen that each column plate 64 interrupted by the rear lateral edge 49 is anchored to a corresponding first isolation panel 62. In addition, the width of the first isolation panel 62 is approximately equal to the width of the column plate 64, and the raised edge 66 of the column plate 64 is positioned approximately aligned with the gap between adjacent first isolation panels 62.

[0110] From Figure 8 and Figure 9 it can also be seen that the second isolation panel 63 is equipped with a column plate anchoring device 84, which is similar to the column plate anchoring device described above with respect to Figure 11 , and the column plate anchoring device 84 is also used to perform the function of anchoring the primary isolation panel 13.

[0111] From Figure 8 and Figure 9It can also be seen that the secondary isolation panels 62 of the first row 60 are alternately provided with a panel anchoring device 69 and a panel anchoring device 81. The anchoring device 69 is a panel anchoring device that only anchors the panel, and the panel anchoring device 81 is a panel anchoring device that also performs the function of anchoring the primary isolation panel 13. It can also be seen that the panel anchoring device 81 of the first secondary isolation panel 62 and the panel anchoring devices of the second secondary isolation panel 63 are aligned in the longitudinal direction with the primary anchoring device 29 attached to the secondary attachment support 23. This alignment is advantageous because it allows the stress in the panel during tank cooling to be limited.

[0112] This arrangement also means that in the area behind the loading / unloading opening 14, the primary isolation panels are each positioned transversely between two primary anchoring devices 29 attached to the secondary attachment support 23.

[0113] Therefore, when each first isolation panel 62 has only a single panel anchoring device 69, this can prevent the stress that may be generated in the secondary sealing film 9 due to the thermal contraction of the first isolation panel 62 if each first isolation panel 62 is attached with multiple panel anchoring devices 69 and thus the multiple panel anchoring devices move closer to each other during tank cooling.

[0114] In addition, as Figure 2 shown, in the area between the rear cofferdam wall 82 and the rear transverse edge 49, the primary isolation panel 13 is arranged to straddle the secondary stop beam 38 and the isolation element 58 of the corner structure 50. The advantage of this arrangement is that the step phenomenon in the support surface of the primary sealing film 11 can be prevented or at least limited. In addition, the primary isolation panel 13 has recesses formed on the outer surface of the primary isolation panel, and these recesses allow each primary isolation panel to accommodate one of the above-mentioned panel anchoring devices 69.

[0115] Referring to Figure 12 , a partial sectional view of the liquefied gas carrier 70 shows a generally prismatic sealed and isolated tank 71 installed in the double hull 72 of the carrier. The wall of the tank 71 includes a primary sealing barrier for contacting the liquefied natural gas contained in the tank, a secondary sealing barrier provided between the primary sealing barrier and the double hull 72 of the carrier, and two isolation barriers provided between the primary sealing barrier and the secondary sealing barrier and between the secondary sealing barrier and the double hull 72, respectively.

[0116] In a manner known per se, the loading / unloading pipeline 73 provided on the deck of the carrier can be connected to a seaport or port terminal through a suitable connector to transfer liquefied natural gas cargo to the tank 71 or to transfer liquefied natural gas cargo from the tank 71.

[0117] Figure 12 An example of an offshore terminal is shown, which includes a loading and unloading station 75, a subsea pipeline 76, and an onshore facility 77. The loading and unloading station 75 is a fixed offshore facility and includes a movable arm 74 and a tower 78 that supports the movable arm 74. The movable arm 74 carries bundles of flexible insulated pipelines 79, which can be connected to the loading / unloading pipeline 73. The orientable movable arm 74 can be adjusted to fit LNG carriers of all sizes. Connecting pipelines (not shown) extend inside the tower 78. The loading and unloading station 75 allows the LNG carrier 70 to load or unload from or to the onshore facility 77. The facility includes a tank 80 for storing liquefied gas and a connecting pipeline 81 connected to the loading or unloading station 75 via the subsea pipeline 76. The subsea pipeline 76 allows the long-distance - for example, 5 kilometers - transmission of liquefied natural gas between the loading and unloading station 75 and the onshore facility 77, which enables the LNG carrier 70 to be kept at a relatively far distance from the shore during loading and unloading operations.

[0118] To generate the pressure required for transporting the liquefied gas, pumps on the carrier 70, and / or pumps installed in the onshore facility 77, and / or pumps installed in the loading and unloading station 75 are utilized.

[0119] Although the present invention has been described with respect to several specific embodiments, it is obvious that the present invention is not limited thereto, and the present invention includes all technical equivalents of the device and their combinations, as long as these technical equivalents and their combinations fall within the scope defined by the claims of the present invention.

[0120] The use of the verb "comprise", or "include" and its variations does not exclude the presence of other elements or other steps other than the elements or steps mentioned in the claims.

[0121] In the claims, any reference signs in parentheses shall not be construed as limiting the claims.

Claims

1. A liquefied gas storage facility, comprising a support structure (2) and a sealed and thermally insulated tank (71) supported by the support structure (2), the support structure (2) comprising an upper support wall (8), and the tank (71) comprising a top wall (4) attached to the upper support wall (8), the top wall (4) comprising, in a thickness direction from the outside to the inside of the tank: a secondary heat insulating barrier (7) attached to the upper support wall (8), a secondary sealing membrane (9) arranged against the secondary heat insulating barrier (7), a primary heat insulating barrier (10) arranged against the secondary sealing membrane (9), and a primary sealing membrane (11) arranged against the primary heat insulating barrier (10) and used for contact with the liquefied gas, the top wall (4) being partially interrupted to define a loading / unloading opening (14), the loading / unloading opening being used for allowing a loading / unloading pipe to pass through the loading / unloading opening, the loading / unloading opening (14) being defined by a front transverse edge (6) and a rear transverse edge (49) parallel to a transverse direction (T) and a first longitudinal edge and a second longitudinal edge (5) parallel to a longitudinal direction (L) perpendicular to the transverse direction (T); The secondary thermal insulation barrier (7) of the top wall (4) comprises a first row (60) of first insulation panels (62) aligned in the transverse direction and arranged between the rear transverse edge (49) and a rear cofferdam wall (82); The secondary sealing membrane (9) of the top wall (4) comprises a plurality of parallel first columns (64) between the rear transverse edge (49) and the rear cofferdam wall (82), the first columns (64) extending in the longitudinal direction and interrupted by the rear transverse edge (49), each first column (64) comprising a flat central portion (65) arranged against the first insulating panel (62) and two raised edges (66) projecting towards the interior of the tank relative to the central portion (65), the first columns (64) being juxtaposed in a repeating pattern in the transverse direction and being sealingly welded together at the raised edges (66), The first insulation panel (62) is provided with strake anchors (69, 81), and the flat portion (65) of each of the first strakes (64) is welded to one of the strake anchors (69, 81).

2. The liquefied gas storage facility according to claim 1, wherein: Each first insulation panel (62) is provided with a single strake anchoring means (69, 81).

3. The liquefied gas storage facility according to claim 1 or 2, wherein: The first insulation panels (62) have a transverse dimension equal to the transverse dimension of the first columns (64), and the first insulation panels (62) are each aligned with one of the first columns (64) so ​​that the raised edge (66) of the first column (64) is positioned to align with a gap between two adjacent first insulation panels (62).

4. The liquefied gas storage facility according to any one of claims 1 to 3, wherein: Each strake anchoring device (69, 81) comprises: - a panel attached to one of said first insulation panels, - a pin (85) which is attached to the plate (84) and extends from the plate (84) in the thickness direction of the top wall toward the interior of the tank (71), and which sealingly passes through a hole formed in the flat portion (65) of one of the first columns of plates (64); the pin (85) includes a flange (86) sealingly attached to the first column of plates (64) around the hole.

5. The liquefied gas storage facility according to any one of claims 1 to 4, wherein: The secondary thermal insulation barrier (7) of the top wall (4) comprises a second row (61) of second insulation panels (63) aligned in the transverse direction and arranged between the first row (60) of the first insulation panels (62) and the rear cofferdam wall (82).

6. The liquefied gas storage facility according to claim 5, wherein: The second insulation panel (63) is provided with strake anchors (81), the flat portions (65) of at least some of the first strakes (64) being welded to one of the strake anchors of the second insulation panel (63).

7. The liquefied gas storage facility according to any one of claims 1 to 6, wherein: The first row of plates (64) is welded along the rear transverse edge (49) to a secondary connecting bracket (19) connected to the upper supporting wall (8).

8. The liquefied gas storage facility according to claim 7, wherein: The secondary thermal insulation barrier (7) of the top wall (4) comprises: - at least a first secondary attachment support and a second secondary attachment support (23) positioned along the rear transverse edge (49); the first secondary attachment support and the second secondary attachment support (23) each comprising: a secondary base (25) anchored to the upper support wall (8); a secondary cap (24) welded to the secondary base (25) and extending in a plane parallel to the upper support wall (8) in a manner parallel to the longitudinal direction; and a plate (30) attached to the secondary cap (24) via an attachment member (31); - at least one border secondary insulating block (37) arranged between said first secondary attachment support and said second secondary attachment support (23) along said first transverse edge (T); and - at least one secondary stop beam (38) extending along the rear transverse edge (49) and arranged at least against the secondary cap (24) of each of the first and second secondary attachment supports (23) and against one of the boundary secondary insulating blocks (37), the secondary stop beam (38) being fixed between the plate (30) and the secondary cap (24) of each of the first and second secondary attachment supports (23) in the thickness direction of the top wall; The secondary connection bracket (19) comprises a first wing (20) arranged against the secondary stop beam (38) and a second wing (21) connected to the upper support wall (8).

9. The liquefied gas storage facility according to claim 8, wherein: The first secondary attachment support and the second secondary attachment support support primary anchoring devices (29) used to anchor the primary thermal insulation barrier (10), and some of the strake anchoring devices (69, 81) provided with the first insulation panel (62) are aligned with the primary anchoring devices (29) in the longitudinal direction (L).

10. The liquefied gas storage facility according to claim 8 or 9, wherein: The primary thermal insulation barrier of the top wall (4) comprises a primary insulation panel (13) in the area between the rear cofferdam wall (82) and the rear transverse edge (49), the primary insulation panel (13) being arranged to straddle the secondary stop beam (38) and the insulation element (58) of a corner structure (50) arranged at the junction between the top wall (4) and the rear cofferdam wall (82).

11. The liquefied gas storage facility according to claim 10, wherein: The primary insulation panel (13) in the region positioned between the rear cofferdam wall (82) and the rear transverse edge (49) includes a recess to receive the strake anchoring means (69, 81).

12. The liquefied gas storage facility according to any one of claims 1 to 11, wherein: The first row of plates (64) is welded to a mechanically welded structure (51) extending along the edge where the top wall (4) meets the rear cofferdam wall (82) and is attached to the top wall (4) and the rear cofferdam wall (82).

13. A transport vehicle (70) for transporting liquefied gas, the transport vehicle comprising the liquefied gas storage facility according to any one of claims 1 to 12.

14. A system for transmitting liquefied gas, the system comprising: A transport vehicle (70) according to claim 13; and an isolated pipeline (73, 79, 76, 81) arranged to connect the tank (71) mounted in the hull of the transport vehicle to a floating storage facility or an onshore storage facility (77).

15. A method for loading or unloading a transport vehicle (70), wherein: The liquefied gas is transported from a floating storage facility or an onshore storage facility (77) via an isolated pipeline (73, 79, 76, 81) to a tank (71) of a transport vehicle (70) according to claim 13, or the liquefied gas is transported from a tank (71) of a transport vehicle (70) according to claim 13 to a floating storage facility or an onshore storage facility (77) via an isolated pipeline (73, 79, 76, 81).

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