RU2801408C1 - Guide structure for tower for loading/unloading a tank designed for storage and/or transportation of liquefied gas - Google Patents

Abstract

FIELD: transportation tanks; storage tanks.

SUBSTANCE: group of inventions relates to a tank for transportation and/or storage of liquefied gas. The tank contains a supporting structure, a group of walls (27), each of which contains in the direction (E) of the wall thickness (27): one heat-insulating layer (41), based on the supporting structure, and one sealing membrane, based on the heat-insulating layer (41). At the same time, the group of walls (27) includes a bottom wall (27), a guide structure (77), which is configured to receive a tower for loading and/or unloading liquefied gas contained in the tank. The guide structure (77) contains a base (93) which rests on the supporting structure, and the heat-insulating layer (41) contains one self-supporting heat-resistant panel (43). The heat-insulating layer (41) contains a gap (151) limited by a section (96) of a self-supporting heat-resistant panel (43) and a supporting structure. The gap (151) is configured to accommodate a part of the base (93) of the guide structure (77).

EFFECT: increased strength and improved thermal insulation.

15 cl, 6 dwg

Description

The present invention relates to the field of tanks capable of containing liquefied gas. More specifically, the invention relates to the bottom wall of a tank, such as a gravity platform or land tank, for storing a liquefied gas, such as liquefied natural gas (LNG), for example, or liquefied petroleum gas (LPG).

In the prior art, sealed and insulated storage tanks for liquefied gas are known, submerged on a gravity platform or vessel. They are generally equipped with a tower for loading/unloading the liquefied gas contained in the tank. The loading and unloading tower is generally suspended from the upper wall of the supporting structure, representing the main structure of the gravity platform or the inner hull of the ship. The tank may equally include a guide structure that is attached to the supporting structure of the bottom wall of the tank and/or sump. The guide structure is configured to maintain the lower part of the loading and unloading tower in a predetermined position relative to the horizontal plane, while allowing the loading and unloading tower to move in the vertical direction.

The guide structure is immersed in liquefied gas when the tank contains it. In this regard, it is necessary to provide for thermal insulation of the guide structure and thermal continuity of the lower wall of the tank through which the guide structure passes. At present, the specifications of the guide structure sometimes make it difficult for the heat insulation of the guide structure and the thermal continuity of the bottom wall.

Moreover, gravity platform tanks are much larger than ship tanks and have only limited resistance to work loads and point loads that occur when the tank is loaded with liquefied gas or when it is unloaded. Moreover, the guide structure is subjected to high mechanical and thermal stresses, in particular from the side of the loading and unloading tower, which results in premature fatigue of the guide structure as well as the bottom wall.

The first object of the present invention is to reduce at least one of the above disadvantages, as well as provide other advantages, by providing a new type of wall for a tank for storing and/or transporting liquefied gas, in particular for a gravity platform.

The second purpose of the invention is to increase the mechanical strength of the fastening of the guide structure at the level of the bottom wall.

The third object of the invention is to obtain a better thermal insulation of the fastening of the guide structure at the level of the bottom wall.

The fourth objective of the invention is to minimize structural deformations of the guide structure.

In this regard, the present invention proposes a tank for transportation and/or storage of liquefied gas, containing a supporting structure, a group of walls of the tank, each of which contains in the direction of the wall thickness at least one heat-insulating layer based on the supporting structure, and at least one a sealed membrane resting on a heat-insulating layer, while the tank wall group contains at least one bottom wall, a guide structure configured to receive a tower for loading and / or unloading liquefied gas contained in the tank, while the guide structure is located on the supporting structure , continues at least partially inside the tank and contains a base resting on the supporting structure, while the heat-insulating layer contains at least one self-supporting heat-resistant panel, which is at least partially located around the guide structure, characterized in that the heat-insulating layer contains a gap limited in the direction of the thickness of the bottom wall by a section of the self-supporting heat-resistant panel and the supporting structure, while the gap is made with the possibility of accommodating at least part of the base of the guide structure.

By "self-supporting" here, as well as throughout the rest of the application, it is to be understood that the self-supporting heat resistant panel is capable of supporting the weight of something placed on top of it, such as liquefied natural gas, without significant deformation and within its mechanical strength.

The gap provided in the heat-insulating layer made of self-supporting heat-resistant panels is configured to receive the base portion of the guide structure. Thus, the self-supporting heat-resistant panels are arranged to be positioned as close as possible to the guide structure and thus form part of the heat insulation of the guide structure.

According to one embodiment, the gap has a thickness between 25 mm and 70 mm inclusive. The thickness is measured from the inner surface of the supporting structure to the outer surface of the section of self-supporting heat-resistant panels in a direction parallel to the thickness direction.

According to one embodiment, the portion of the self-supporting heat-resistant panel that limits the gap in the thickness direction comprises a plywood or composite board.

According to one embodiment, a section of the self-supporting heat-resistant panel rests on the base of the guide structure, in particular on the plate of this base.

According to one embodiment, the spacer is located between the base of the guide structure, in particular on the plate of this base, and part of the section of the self-supporting heat-resistant panel resting on the base of the guide structure.

According to one embodiment, the spacer is a mastic insert or bead, or a combination of the two.

According to one embodiment, the reservoir comprises at least one locking device configured to immobilize the guide structure in at least a direction perpendicular to the thickness direction of the bottom wall.

In accordance with one embodiment, the locking device is placed in the gap.

According to one embodiment, the locking device is made of metal.

In accordance with one embodiment, another portion of the self-supporting heat-resistant panel section rests on the locking device.

In accordance with one embodiment, the locking element is located between the locking device and another section of the self-supporting panel.

According to one embodiment, the locking element is a mastic insert or bead, or a combination of the two.

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

In accordance with one embodiment, the locking device is located between the edge of the self-supporting heat-resistant panel and the base of the guide structure.

In accordance with one embodiment, the heat-insulating element is located between the base of the guide structure and the supporting structure. This thermal insulation element also has the function of adjusting the position along the vertical axis of the guide structure.

According to one embodiment, the thermal insulation layer is the auxiliary thermal insulation layer and the sealing membrane is the main sealing membrane, and if the tank comprises the main thermal insulation layer and the auxiliary sealing membrane, the auxiliary sealing membrane is supported by the auxiliary thermal insulation layer, the main thermal insulation layer is supported by an auxiliary hermetic membrane, and the main hermetic membrane rests on the main heat-insulating layer.

In accordance with one embodiment, the main thermal insulation layer and/or the secondary thermal insulation layer comprise a group of self-supporting heat resistant panels, each of which contains a block of polyurethane foam on which at least one plywood or composite material board is located.

In accordance with one embodiment, the supporting structure is made of a material selected from the group consisting of metal, metal alloy, concrete, and mixtures thereof.

The invention further provides a transportation and/or storage plant comprising at least one tank according to the invention and selected from the group consisting of a methane tanker, an LPG tanker, a barge, a reliquefaction plant, a gasification plant, a land structure, for example , ground tank, and gravity platform.

According to one embodiment, the transport and/or storage installation comprises a base structure in which the reservoir according to the invention is fixed, the base structure being made of concrete.

The invention also provides a liquefied gas transmission system comprising a gravity platform according to the invention, insulated pipes positioned to connect a tank installed in the base structure of the gravity platform to a vessel, and a pump for driving a flow of liquefied gas through the insulated pipes from the gravity platform tank. platforms to the ship.

The invention further provides a method for loading or unloading a gravity platform according to the invention, in which liquefied gas is directed through insulated pipes from the gravity platform tank to the vessel.

The content of the disclosure also contains a tank for transporting and/or storing liquefied gas, containing a supporting structure, a group of walls of the tank, each of which contains in the direction of the wall thickness at least one heat-insulating layer based on the supporting structure, and at least one sealed membrane , resting on a heat-insulating layer and designed to be in contact with liquefied gas inside the tank, while the tank wall group contains at least a bottom wall, and a guide structure configured to receive a loading and / or unloading tower and located on a supporting structure, differing the tank contains a group of locking devices attached to the supporting structure and in contact with the base of the guide structure in such a way as to block the movement of the guide structure in a direction perpendicular to the direction of the thickness of the bottom wall.

Other features and advantages of the invention will become more apparent in the course of the following description, on the one hand, and from the group of embodiments described by way of non-limiting illustration with reference to the attached schematic drawings, on the other hand, in which:

Figure 1 is a schematic perspective view of a tank according to the invention;

Figure 2 is a schematic cross-sectional view along the transverse vertical plane of the tank in Figure 1;

Figure 3 is a schematic view of the tank wall structure of Figure 2 as viewed in the wall thickness direction;

Figure 4 is a detailed cross-sectional view along a transverse vertical plane of the guide structure in Figure 1 for guiding the loading and unloading tower in Figure 1 in vertical movement;

Figure 5 is a detailed view of the locking device of the guide structure illustrated in Figure 4;

Figure 6 is a schematic representation of a methane tanker tank and a gravity loading and unloading platform containing a tank according to the invention.

First of all, it should be noted that, although the invention is disclosed in the Figures in a detailed manner for its implementation, they can, of course, serve to better define the invention if necessary. It should also be noted that throughout the Figures, elements that are similar and/or have the same function are designated by the same reference numerals.

In the following description, the direction of the longitudinal axis L, the direction of the transverse axis T and the direction of the vertical axis V are represented by a trihedron (L, V, T) in Figures 1 and 2 and Figures 4 and 5. The horizontal plane is defined as the plane perpendicular to the vertical axis, the longitudinal plane is as a plane perpendicular to the transverse axis, and the transverse plane as a plane perpendicular to the longitudinal axis.

The terms "external" and "internal" are used to define the relative position of one element relative to another, with reference to the internal and external areas of the tank.

In Figure 1, the sealed and heat-insulating liquefied gas storage tank 21 is fixed in a concrete supporting structure 3. The supporting structure 3 is formed by, for example, the base structure of the gravity platform 1. Hereinafter, the expressions "base structure" and "support structure" are used interchangeably and with the same the same reference position.

In an embodiment which is not shown, the supporting structure 3 is formed by the double hull of the ship. The ship may be a methane tanker or an LPG tanker. The supporting structure 3 can also be formed by a double holding structure, such as a barge, a reliquefaction plant, a gasification plant, or a surface structure such as an above ground tank.

More specifically, in Figure 2, which is a sectional view of the tank 21 in Figure 1 along the sectional plane 150, the supporting structure 3 comprises a double lower dividing wall 5, an upper dividing wall 9 and double side dividing walls 7 connecting the double lower dividing wall 5 with an upper dividing wall 9. Each double dividing wall 5, 7 contains an external dividing wall 11 and an internal dividing wall 1ma made of concrete. The inner dividing walls 13 and the upper dividing wall 9 form the overall shape of the tank 21. The outer dividing walls 11 and the inner dividing walls 13 are connected to each other by concrete spacers 15.

The lower part of the structure 3 of the base contains ballast compartments 17. The ballast compartments 17 are located between the inner dividing wall 13 and the outer dividing wall 11 of the double lower dividing wall 5. The ballast compartments 17 are filled with sea water when the gravity platform 1 is located at its place of operation, thus, so that the gravity platform 1 sinks due to its ballasting. As a result, the gravity platform 1 partially rests on the seabed.

It should be noted that the base structure 3 also includes an insert, such as a metal insert, embedded in the concrete of the base structure. An insert of this kind extends horizontally, extending in the vertical direction under the guide structure 77, which will be described later, between the latter and the concrete.

In Figure 2 and Figure 3, the tank 21 includes a group of walls 23, 25, 27, each of which is located on the inner dividing wall 13 and the upper dividing wall 9 of the structure 3 of the base. Accordingly, the tank 21 comprises an upper wall 23 located on the inner surface of the upper dividing wall 7 and a lower wall 27 located on the inner surface of the inner dividing wall 13. The upper dividing wall 23 and the lower wall 27 continue in a major plane substantially parallel to the horizontal plane, as mentioned above. The top wall 23 is substantially parallel to the bottom wall 27 and does not intersect it. Here and throughout, it should be understood that "substantially" means that manufacturing tolerances and any assembly tolerances must be taken into account.

The top wall 23 and the bottom wall 27 are connected to each other by side walls 25 located on the inner surface of the other inner dividing walls 13. Each of the side walls 25 extends in a plane substantially perpendicular to the horizontal plane from one edge of the bottom wall 27 to the edge of the top wall. 23. The reservoir 21 has the general shape of a rectangular parallelepiped.

In Figure 3, each wall 23, 25, 27 includes, in the direction E of the wall thickness 23, 25, 27, an auxiliary heat insulating layer 41 held on the respective dividing wall of the base structure 3, an auxiliary hermetic membrane 51 resting on the auxiliary heat insulating layer 41, the main heat insulating layer 61 supported by the auxiliary seal membrane 51 and the main seal membrane 71 for contact with the liquefied natural gas contained in the tank 21 and supported by the main thermal insulation layer 61.

The auxiliary thermal insulation layers 41 of the walls 23, 25, 27 of the tank 21 communicate with each other so as to form between the base structure 3 and the auxiliary sealed membrane 51 a continuous and sealed auxiliary thermal insulation space. Similarly, the main heat-insulating layers 61 of the walls 23, 25, 27 of the tank 21 communicate with each other in such a way as to form between the auxiliary sealed membrane 51 and the main membrane 71 a continuous and sealed main heat-insulating space.

The auxiliary thermal insulation layer 41 includes a group of self-supporting heat-resistant panels 43. The self-supporting heat-resistant panels 43 are shaped in a substantially rectangular parallelepiped. The self-supporting heat-resistant panels 43 may have other shapes such as, for example, a parallelepiped shape, in particular with a square base or a rectangular base, or a rectangular prism shape with a hexagonal base. Self-supporting heat-resistant panels 43 are arranged next to each other in parallel rows.

Each of the self-supporting heat resistant panels 43 includes a block of heat resistant polymeric foam 45 supported by an outer rigid board 47. The rigid outer board 47 is, for example, a plywood board. The rigid outer board 47 is glued to said block of heat resistant polymer foam 45. The heat resistant polymer foam may in particular be a polyurethane based rigid foam. Fiberglass can be embedded in polyurethane foam to reinforce it. In an embodiment not shown, the rigid outer plate 47 is made from at least one composite material.

Due to manufacturing inaccuracies, for example, the inner surface of the inner dividing walls 13 and the inner surface of the upper dividing wall 9 may differ greatly from the theoretical area provided for the base design. These differences are compensated by the fact that the self-supporting heat-resistant panels 41 must be supported on the base structure by polymerizable resin beads 40 or mastic.

The self-supporting heat-resistant panels 41 are attached to the inner dividing walls 13 and to the upper dividing wall 9 by means of studs, not shown, welded to the inner surface of the inner dividing walls 13.

The auxiliary seal membrane 51 comprises a group of rigid seal layers 53 made of 0.07 mm thick aluminum foil sandwiched between two glass fiber mats impregnated with polyamide resin. The rigid seal layers 53 are bonded to the polymeric foam blocks 45 of the self-supporting heat resistant panels 43, for example with a two-component polyurethane adhesive.

In order to give the secondary membrane some flexibility and to ensure its continuity between two adjacent rigid seal layers 53, the flexible seal layer 55 is bonded to the adjacent peripheral edges of the two adjacent rigid seal layers 53. The flexible seal layer 65 consists of a composite material containing three layers: the two outer layers represent are fiberglass mats and the interlayer is a thin metal foil, such as aluminum foil, approximately 0.1 mm thick. This metal foil guarantees the continuity of the secondary sealing membrane.

The main heat-insulating layer 61 includes a group of self-supporting heat-resistant panels 63 in the form of a substantially rectangular parallelepiped. The self-supporting heat-resistant panels 63 of the main heat-insulating layer 61 may have other shapes, such as a cubic shape, for example. In the embodiment shown in Figure 3, the self-supporting heat-resistant panels 63 of the main heat-insulating layer 61 are offset relative to the self-supporting heat-resistant panels 43 of the auxiliary heat-insulating layer 41 so that each main insulation panel 63 of the main heat-insulating layer 61 continues on four self-supporting heat-resistant panels 43 of the auxiliary heat-insulating layer 41 .

Each self-supporting heat-resistant panel 63 of the main thermal insulation layer 61 contains a block of heat-resistant polymer foam 65, for example, based on rigid polyurethane. The first side of this block of polymer foam 65 is glued to the auxiliary seal membrane 51, and the second side opposite the first side is covered with a rigid inner plate 69. Glass fibers can be embedded in the polymer foam to reinforce it. The rigid inner board 69 of the self-supporting heat-resistant panel 63 of the base heat-insulating layer 61 is made of, for example, plywood or a composite material.

The main seal membrane 71 comprises a group of metal plates that are welded to each other. In the embodiment illustrated in Figure 3, the main sealed membranes 71 comprise corrugations 75 in metal plates that allow them to deform under the influence of thermal and mechanical loads created by the liquefied gas in the tank 21. The main sealed membrane 71 contains two mutually perpendicular sequences of corrugations 75. Corrugations 75 protrude into the tank 21. The rigid inner plate 69 of each self-supporting heat-resistant panel 63 of the main thermal insulation layer 61 is equipped with metal prefabricated plates (not shown) for fastening the corrugated metal sheets of the main sealed membranes 71. Prefabricated plates can be assembled with each other, for example, with using welding.

In Figure 1, the tank 21 includes a guide structure 77 located on the carrier structure 3. The guide structure 77 is adapted to receive a tower 29 for loading and/or unloading the liquefied gas contained in the tank 21.

The loading and unloading tower 29 extends essentially along the entire height of the tank 21, that is, from the bottom wall to the top wall, from which its upper part 33 is suspended. The loading and unloading tower 29 includes three vertical masts 31 connected together by cross members (not shown), forming the shape of a prism with a triangular section. The vertical masts 31 are hollow for the passage of power cables (not shown) supplying, inter alia, power to the tank discharge pumps 21 (not shown) through the discharge lines (not shown) of the loading tower 29. In an embodiment that is not shown , the loading and unloading tower 29 may include two vertical masts or four vertical masts.

The loading and unloading tower 29 includes in its lower part 35 a guide 37 which cooperates with the guide structure 77 of the tank 21. The guide device 37 is designed to allow the loading and unloading tower 29 to move relative to the guide structure 77 in the direction of the height of the tank 21 in order to to allow the loading and unloading tower 29 to contract or expand depending on the temperatures to which it is subjected, while preventing the bottom portion 31 of the loading and unloading tower 29 from moving horizontally.

The guide structure 77, located in the area of the bottom wall 27 of the tank 21, facing the central axis of the loading and unloading tower 29, will be described in more detail with reference to Figure 4, which is a view of the guide structure in the sectional plane 200 indicated in Figure 1. To simplify Figure 4, the main seal membrane 71 and the auxiliary seal membrane 51 are not shown.

The guide structure 77 includes a base resting on the supporting structure 3.

The guide structure 77 comprises a hollow lower part 79 which is, for example, in the shape of a truncated cone and which is connected to an upper part 78 of a regular cylindrical shape. This lower part 79 is similar to the base of the guide structure 77 mentioned above. The upper part 78 protrudes into the tank 21 so as to interact with the guide device 37 of the loading and unloading tower 29. The lower part 79 extends through the thickness of the bottom wall 27 of the tank 21 to the main sealed membrane 71.

The bottom part 79 or base comprises at least one plate 93 supported on the supporting structure 3, the plane in which the plate 93 continues is a plane perpendicular to the thickness direction E of the bottom wall 27. This plate 93 is the part of the base that continues in the gap 151 formed in the heat-insulating layer 41.

The frustoconical bottom or base 79 comprises a small round base 80 and a large round base 81. The small base 80 and the large base 81 are each formed in a plane perpendicular to the thickness direction E of the bottom wall 27. The small base 80 has a diameter smaller than that of the large base 81. The top 78 has a diameter substantially equal to that of the small base 80. Moreover, the large the base 81 is located closer to the supporting structure 3 than the small base 80. The lower part 79 contains a radial wall 88 that extends from the contour of the small base 80 to the contour 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 on the top 78 of the guide structure 77 by a first plate 82 that extends in a plane perpendicular to the thickness direction E of the bottom wall 27. The first plate 82 may take various forms. In the example shown, the first plate 82 has a circular shape when viewed in a plane perpendicular to the direction E of the thickness of the bottom wall 27. The first plate 82 has a diameter greater than the diameter of the small base 80. Accordingly, the outer part 83 of the first plate 82 extends from the small base 80 in the direction of the main sealed membrane 71 in order to connect with it. This outer part 83 of the first plate 82 is located continuously with the main sealed membrane and contributes to its sealing and isolation. The inner part 84 of the first plate 82 continues in line with the outer part 83 inside the lower part 79 of the guide structure 77.

The guide structure 77 includes a second plate 85 located between the small base 80 and the large base 81 of the lower part 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 may have various shapes. In the example shown, the second plate 85 has a circular shape when viewed in a plane perpendicular to the thickness direction E of the bottom wall 27.

The second plate 85 is positioned so as to be in line with the auxiliary seal membrane 51 in order to be connected to it. As such, the second plate 85 is at substantially the same level as the secondary seal membrane 51. 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 seal membrane and contributes to its sealing and isolation. The outer part 86 of the second plate 85 extends circumferentially from the radial wall 88 of the lower part 79 of the guide structure 77. The outer part 86 of the second plate 85 is designed to be connected to the auxiliary sealed membrane 41.

The inner part 87 of the second plate 85 extends inside the lower part 79 of the guide structure 77. Accordingly, the inner space of the lower part 79 is divided into an auxiliary section 90 and a main section 91. In this regard, the main section 91 is limited by the first plate 82, the second plate 85 and the radial wall 88 lower part 79. Auxiliary section 90 is bounded by a second plate 85, a double lower dividing wall 5 of structure 3 of the base and a radial wall 88 of the lower part 79 of the guide structure 77. A non-structural insulating gasket (not shown) is located in the main section 91 and / or in the auxiliary section 90 The non-structural insulating lining is, for example, glass wool, mineral wool or a mixture thereof. Therefore, the thermal conductivity in the guide structure 77 is limited.

The self-supporting heat-resistant panels 63 of the main thermal insulation layer 61 adjacent to the guide structure 77 rest on at least one self-supporting heat-resistant panel 43 of the auxiliary thermal insulation layer 41 and on the outer portion 86 of the second plate 85. The self-supporting heat-resistant panels 63 of the main thermal insulation layer 61 adjacent to the rail structure 77 also rest on the outer part 86 of the second plate 85. heat-resistant panels 63 of the main heat-insulating layer 61 adjacent to the guide structure 77, and the radial wall 88 of the lower part 79 of the guide structure 77. The non-structural insulating pad 92 thus arranged is, for example, glass wool, mineral wool or a mixture thereof.

The radial wall 88 of the lower part 79 includes through holes 89. Some of the holes 89 in the radial wall 88 are arranged in such a way as to establish aeraulic communication between the auxiliary heat-insulating space and the auxiliary section 90 of the internal space of the lower part 79. In this regard, the circulation of inert gas is facilitated, such as nitrogen or argon, for example, between the auxiliary heat-insulating space and the auxiliary section 90. Some other openings 89 in the radial wall 88 are located in such a way as to establish aeraulic communication between the main heat-insulating space and the main section 91 of the internal space of the lower part 79. In connection with this facilitates the circulation of an inert gas such as nitrogen or argon, for example, between the main thermal insulation space and the main section 91.

The guide structure 77 includes a plate 93 arranged circumferentially around a large base 81 of 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. The plate 93 has a perimeter of a square shape when viewed in a plane perpendicular to the direction E thickness. The plate 93 rests on the inner dividing wall 13 of the double bottom dividing wall 5 of the supporting structure 3. In other words, the guide structure 77 rests on a base formed at least in part by a plate 93 that is in planar contact with the supporting structure 3. The plate 93 is attached to the supporting structure. structures 3 with a system of nuts and bolts (not shown).

The heat insulating element 94 is inserted between the inner surface of the inner partition wall 13 and the plate 93 so as to break the thermal bridge between the supporting structure 3 and the guide structure 77. The heat insulating element 94 is, for example, a plywood board or a composite material board. The thickness of this insulating element also contributes to the adjustment in the vertical direction of the height of the position of the guide structure 77.

In order to position as close as possible to the self-supporting heat-resistant panels of the auxiliary heat-insulating layer 41, taking into account the plate 93 of the guide structure 77, each self-supporting heat-resistant panel 43 of the auxiliary heat-insulating layer 41 adjacent to the plate 93 contains a cutout 95. The cutout 95 has a rectangular shape when viewed in projection in plane containing the direction E of the thickness of the bottom wall 27. The cutout 95 is made in the lower part of the self-supporting heat-resistant panel 43 of the auxiliary thermal insulation layer 41 adjacent to the plate 93. , and the side intermediate edge 99 of the self-supporting heat-resistant panel 43 of the auxiliary thermal insulation layer 41 adjacent to the plate 93. surface of the inner dividing wall 13 of the double bottom wall 5 of the supporting structure 3.

The upper intermediate portion 96 of the self-supporting heat-resistant panel 43 of the auxiliary heat-insulating layer 41 adjacent to the plate 93 comprises a plywood or composite board 98 located at the level of the outer intermediate surface 97. This makes it possible to increase the mechanical strength of the self-supporting heat-resistant panel 43 of the auxiliary heat-insulating layer 41 adjacent to plate 93.

Accordingly, the auxiliary thermal insulation layer 41 has a gap 151 defined in the thickness direction E of the bottom wall 27 by the outer intermediate surface 97 of the upper intermediate portion 96 of the self-supporting heat-resistant panel of the auxiliary thermal 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 load-bearing structure 3. In other words, the gap 151 is limited in the direction of the thickness E of the bottom wall 27 by a section of the self-supporting heat-resistant panel 43 of the auxiliary heat-insulating layer 41 adjacent to the plate 93 and the supporting structure 3. In this connection, at least a part of the base is placed in the gap 151, in particular the plate 93 of the guide structure 77, in a direction parallel to the direction E of the thickness of the bottom wall 27.

The gap 151 has a thickness H 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 dividing wall 13 of the lower double dividing wall 5 of the supporting structure 3 to the outer intermediate surface 97 of the upper intermediate portion 96 of the self-supporting heat-resistant panel 43 of the auxiliary heat-insulating layer 41 adjacent to the plate 93. 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 direction E of the thickness of the bottom wall 27.

The gap 151 is limited in the direction perpendicular to the direction E of the thickness of the bottom wall 27 by the side intermediate edge 99 of the self-supporting heat-resistant panel 43 of the auxiliary heat-insulating layer 41 adjacent to the plate 93 and the guide structure 77. In other words, the length of the gap 151 exceeds the length of the plate 93, while the length is measured in a direction perpendicular to the thickness direction E of the bottom wall 27. The gap 151 accommodates at least a portion of the plate 93 in a direction perpendicular to the thickness direction E of the bottom wall 27.

The self-supporting heat-resistant panels 43 of the auxiliary thermal insulation layer 41 adjacent to the guide structure 77 are partially in contact with the edge of the outer portion 86 of the second plate 85. To improve thermal insulation, a non-structural insulation pad 92 is located between the self-supporting heat-resistant panel 43 of the auxiliary thermal insulation layer 41 adjacent to the guide structure. 77, and the radial wall 88 of the lower part 79 of the guide structure 77. The portion 97a of the outer intermediate surface 97 of the upper intermediate portion 96 of the self-supporting heat-resistant panel 43 of the auxiliary thermal insulation layer 41 adjacent to the plate 93 rests on the portion of the plate 93 placed in the gap 151. In order to in order to at least partially compensate for the manufacturing tolerances of the plate 93 and/or the self-supporting heat-resistant panel 43 of the auxiliary heat-insulating layer 41 adjacent to the plate 93, the spacer 153 is located between the plate 93 and the portion of the outer intermediate surface 97, based on the portion of the plate 93 placed in gap 151. Spacer 153 is an insert or bead of mastic, or a combination of the two. The insert may be made from plywood and/or from at least one composite material.

The spacer 153 is one of the components that contribute to controlling the vertical position of the guide structure 77. In fact, it is necessary to align the outer part 83 of the first plate 82 with the main sealing membrane in the same plane. It is equally necessary to align the outer portion 86 of the second plate 85 in the same plane as the auxiliary seal membrane. The spacer 153 participates in this function.

In Figure 4 and Figure 5, the tank 21 includes at least one locking device 155 configured to immobilize the guide structure 77 in at least one direction perpendicular to the thickness direction E of the bottom wall 27. The locking device 155 described below can be independently from the fact that the heat-insulating layer 41 comprises a gap 151 bounded in the direction of thickness E of the bottom wall 27 by a section 96 of the self-supporting heat-resistant panel 43 and the supporting structure 3, while the gap 151 is configured to accommodate at least part of the base of the guide structure 77. Alternatively, the locking device 155, described below, can be directly combined with the thermal insulation layer 41, which includes a gap 151 limited in the thickness direction E of the bottom wall 27 by the portion 96 of the self-supporting heat-resistant panel 43 and the supporting structure 3, while the gap 151 is configured to accommodate at least part the base of the guide structure 77.

The locking device 155 is located on the inner surface of the inner dividing wall of the double bottom dividing wall so that the locking device 155 is placed in the gap 151. The locking device 155 is located between the side intermediate edge 99 of the self-supporting heat-resistant panel 43 and the guide structure 77, in particular its plate 93. The group of locking devices 155, which will be described below, is located on the periphery around the guide structure.

In an embodiment, the locking device 155 includes a steel angle 157 reinforced with a group of stiffeners 163. The angle steel 157 has an L-shaped profile, that is, the angle steel 157 comprises a first section 159 and a second section 161 perpendicular or substantially perpendicular to the first section 159. The first section 159 extends in a plane containing the thickness direction E of the bottom wall 27. In other words, the first section 159 extends in a plane perpendicular to the plane in which the plate 93 continues. The second section 161 extends in a plane perpendicular to the thickness direction E of the bottom wall 27. In other words, the second section 161 extends in a plane parallel to the plane in which the plate 93 continues.

The first section 159 is located on one of the peripheries of the guide structure, in particular the plate 93, while the second section 161 is located on the inner surface of the inner dividing wall 13 of the double bottom dividing wall 5, while continuing in the direction away from the periphery of the guide structure, for example, the plate 93. Steel angle 157 is attached to the inner surface of the inner dividing wall 13 of the double bottom wall 5 by welding to it.

Each stiffener 163 has the shape of a rectangular parallelepiped. For each stiffener 163, one surface of the stiffener 163 is located on the first section 159, and the other surface of the stiffener 163 is located on the second section 161. The stiffeners 163 are evenly distributed along the steel angle 157. As such, two adjacent stiffeners 163 are at a non-zero distance from each other. The second section 161 is interrupted between two adjacent stiffeners 163. In other words, the second section 161 is formed by a group of shelves. Each stiffener 163 is attached to the first section 159 and to one flange of the second section 161 by welding to them.

The tank 21 includes a group of locking devices 155 which abut each edge of the guide structure, in particular the plate 93, to render the guide structure movable in all directions perpendicular to the direction E of the thickness of the bottom wall 27. In other words, the locking devices 155 prevent the guide structure from moving in the directions contained in the plane in which the inner dividing wall 13 of the plate 93 continues.

The locking element 165 can be located on the edge of the guide structure, in particular the plate 93, and the first section 159 of the steel angle 157 of the locking device 155. In this regard, the locking element 165 makes it possible to eliminate any play between the steel angle 157 and the guide structure, here the plate 93, while increasing the mechanical strength of the guide structure. The locking element 165 takes the form of a plate, in particular a wedge, having an acute angle along the longitudinal edge. The acute angle of the locking element 165 is forcibly inserted after the guide structure 77 is attached to the supporting structure 3 and after the locking device 155 is secured around the entire guide structure, here the plate 93. The locking element 165 is welded to the first section 159 of the locking device 155 in order to prevent any vertical movement .

When the tank 21 is assembled, the locking device 155 is located in the gap 151. Another section 97b of the outer intermediate surface 97 of the upper intermediate section 96 of the self-supporting heat-resistant panel 43 of the auxiliary heat-insulating layer 41 adjacent to the plate 93 rests on the stiffeners 163 of the locking device 155.

In order to prevent any drooping of the self-supporting heat-resistant panel 43 supported by both the rail structure 77 and the stop device 155, the stop element 167, 169 is located between the stop device 155 and a plywood or composite board 98 located at the level of the outer intermediate surface 97 of the upper intermediate portion 96 of the self-supporting heat-resistant panel 43 of the auxiliary thermal insulation layer 41, supported by the stiffeners 163 of the locking device 155. In the embodiment illustrated in Figures 4 and 5, the first locking element 167 is a plywood insert and the second locking element 169 is mastic roller. The mastic bead 169 is one of the elements that contribute to the correct vertical positioning of the self-supporting heat-resistant panel 43, and therefore forms the gap 151. In this regard, the mastic bead 169 performs the function of stopping and the function of flattening the components that rest on it.

Note that the plate 98 includes a recess 97c in which at least the first section 159 of the retainer 155 extends. panel 43 regardless of the vertical position of this panel.

The self-supporting heat-resistant panel 43 can also be prevented from hanging down by providing a cut-out 97c in the plate 98 located at the level of the outer intermediate surface 97 of the self-supporting heat-resistant panel 43 of the auxiliary heat-insulating layer 41 adjacent to the plate 93. This cut-out 97c allows the placement of the vertical edge of the first angle steel section 159 157 locking device 155.

The figure 5 also illustrates the composition of the inner dividing wall 13, which contains a metal insert 117, to which the locking device 155 is welded.

Figure 6 shows a transport and/or storage tank with a general shape of a parallelepiped installed in the base structure 3 of a gravity platform 1. Gravity platforms 1 are generally offshore structures used in the context of oil or gas production. These structures often have a concrete base structure known as a gravity-type base structure (GBS); the term "Steel Gravity Structure (SGC)" is also used for the base structure made of steel, to which the invention also relates.

The gravity platforms 1 can simultaneously have the functions of a dam, storage, platform for receiving a liquefaction plant and a loading platform in the context of the production of liquefied gas, such as, for example, liquefied natural gas or ethane.

The wall of the tank 21 contains a main sealed membrane designed to be in contact with the LNG contained in the tank 21, an auxiliary sealed membrane located between the main sealed membrane and the base structure 3 of the gravity platform 1, and two heat-insulating layers, respectively, located between the main sealed membrane and auxiliary sealing membrane and between the auxiliary sealing membrane and the 3 base structure. In a manner known per se, loading and unloading pipes 103 located on the upper deck of the methane tanker 100 can be connected via suitable connectors to the gravity platform 1 for transferring the LNG cargo from the tank 21 or to the tank 21.

Figure 6 shows a gravity platform 1 comprising a loading and unloading station 105, an underwater pipeline 107 and a gravity platform 1. The loading and unloading station 105 is a fixed offshore installation containing a movable arm 111 and a tower 113 that supports the movable arm 111. The movable arm 111 holds a bundle of insulated flexible pipes 115 that can be connected to loading and unloading pipes 103. An orientable movable sleeve 111 adapts to all loading dimensions of methane carriers. The connecting pipe, which is not shown, continues inside the tower 113. The loading and unloading station 105 allows loading at least one tank 22 of the methane tanker 100 from the gravity platform 1 or unloading at least one tank 22 of the methane tanker 100 into the gravity platform 1. The tank 22 of the methane tanker 100 may be a tank according to the invention. The gravity platform 1 comprises at least one liquefied gas storage tank 21 according to the invention and connecting pipes 109 connected by an underwater pipeline 107 to the loading and unloading station 105. The underwater pipeline 107 allows the transfer of liquefied gas between the loading and unloading station 105 and the gravity platform 1 on a long distance, for example 5 km, which allows the methane carrier 100 to remain a long distance from the coast during loading and unloading operations. The pumps on board the methane carrier 100 and/or the pumps equipped with the gravity platform 1 and/or the pumps with which the loading and unloading station 105 is equipped are used to generate the pressure necessary for the transfer of the liquefied gas.

Of course, the invention is not limited to the examples that have just been described, and numerous adaptations can be applied to these examples without departing from the scope of the invention. Thus, the installation for transportation and/or storage may contain a tank 1, for example. Such transportation and/or storage installations may be an LPG tanker, a barge, a reliquefaction plant, a gasification plant, or an above ground structure such as an above ground tank.

The invention just described actually achieves its intended purpose and makes it possible to provide a reservoir containing a guiding structure for a liquefied gas loading and unloading tower, the thermal insulation of which, as well as its mechanical strength against working loads and accidental loads, is increased. Options not described here can be obtained without deviating from the scope of the invention.

Claims (15)

1. Tank (21) for transportation and/or storage of liquefied gas, including a supporting structure (3), a group of walls (23, 25, 27), each of which contains in the direction (E) wall thicknesses (23, 25, 27) at least one heat-insulating layer (41) based on the supporting structure (3), and at least one sealed membrane (71) based on the heat-insulating layer (41), while the group of walls (23, 25, 27) contains at least one lower wall (27), a guide structure (77) configured to receive a tower (29) for loading and/or unloading liquefied gas contained in the tank (21), located on a supporting structure (3) extending at least at least partially inside the tank (21), and containing a base resting on the supporting structure (3), while the heat-insulating layer (41) contains at least one self-supporting heat-resistant panel (43), which is at least partially located around the guide structure (77 ), characterized in that the heat-insulating layer (41) contains a gap (151), limited in the direction (E) of the thickness of the bottom wall (27) by a section (96) of a self-supporting heat-resistant panel (43) and a supporting structure (3), while the gap ( 151) is made to accommodate at least part of the base of the guide structure (77). 2. The tank (21) according to the previous paragraph, characterized in that the base contains at least one plate (93) supported by the supporting structure (3) and continuing in the gap (151) and in a plane perpendicular to the direction (E) of the thickness of the bottom walls (27). 3. A reservoir (21) according to any one of the preceding claims, characterized in that the gap (151) has a thickness (H) between 25 mm and 70 mm inclusive. 4. The tank (21) according to any one of the previous claims, characterized in that the section (96) of the self-supporting heat-resistant panel (43), which limits the gap (151) in the direction (E) of the thickness, contains a plate (98) of plywood or composite material . 5. The tank (21) according to any one of the previous claims, characterized in that part (97a) of the section (96) of the self-supporting heat-resistant panel (43) rests on the base of the guide structure (77). 6. The tank (21) according to the previous paragraph, characterized in that the spacer (153) is located between the base of the guide structure (77) and part (97a) of the section (96) of the self-supporting heat-resistant panel (43) resting on the base of the guide structure (77 ). 7. Reservoir (21) according to the previous paragraph, characterized in that the spacer (153) is an insert or mastic roller or a combination thereof. 8. Tank (21) according to any of the preceding claims, characterized in that the gap (151) is limited in the direction perpendicular to the thickness direction (E) by the edge (99) of the self-supporting heat-resistant panel (43), which extends between the outer surface (97) section (96) of the self-supporting heat-resistant panel (43) and the inner surface of the supporting structure (3), and the guide structure (77). 9. Tank (21) according to any one of the previous claims, characterized in that the heat-insulating element (94) is located between the base of the guide structure (77) and the supporting structure (3). 10. The reservoir (21) according to any of the previous paragraphs, characterized in that it includes at least one locking device (155) placed in the gap (151) and made with the possibility of depriving the guide structure (77) of mobility in at least one direction perpendicular to the direction (E) of the thickness of the bottom wall (27). 11. The tank (21) according to any of the previous paragraphs, characterized in that the heat-insulating layer (41) is an auxiliary heat-insulating layer, and the sealed membrane (71) is the main sealed membrane, while the tank (21) includes the main heat-insulating layer ( 61) and the auxiliary sealing membrane (51), the auxiliary sealing membrane (51) rests on the auxiliary heat-insulating layer (41), the main heat-insulating layer (61) rests on the auxiliary sealing membrane (51), and the main sealing membrane (71) rests on the main thermal insulation layer (61). 12. Gravity platform (1), including a tank (21) for storing liquefied gas according to any of the previous paragraphs and a tower (29) for loading / unloading liquefied gas contained in the tank, while the loading and unloading tower (29) is configured to interaction with the guide structure (77) of the tank (21). 13. Gravity platform (1) according to the previous paragraph, including the structure (3) of the base, in which the tank (21) is fixed, made of concrete. 14. The transmission system of liquefied gas, including gravity platform (1) according to any one of paragraphs. 12 or 13, insulated pipes (103, 107, 109, 115) located with the possibility of connecting a tank (21) installed in the base structure (3) of the gravity platform (1), with a vessel (100), and a pump for propulsion flow of liquefied gas through insulated pipes (103, 107, 109, 115) from the tank (21) of the gravity platform (1) to the vessel (100). 15. The method of loading or unloading the gravity platform (1) according to any one of paragraphs. 12 or 13, in which the liquefied gas is sent through insulated pipes (103, 107, 109, 115) from the reservoir (21) of the gravity platform (1) to the vessel (100).