CN116648576A - Liquid dome for a storage tank for liquefied gas - Google Patents

Abstract

The application relates to a storage facility (1) for liquefied gas and sealed and thermally insulated tanks, comprising: a loading/unloading opening (10) having an upper cover wall (23), a lower cover wall (22) and an insulating structure (24) between the lower cover wall (22) and the upper cover wall (23), the liquid dome conduit (30) and the upper cover wall (23) being made of different iron-based alloys, and at least one fastening lug (50) protruding from the upper cover wall (23) being sealingly fastened to the primary sealing film (19) in a direct or indirect manner.

Description

Liquid dome for a storage tank for liquefied gas

Technical Field

The present application relates to the field of storage facilities for liquefied gases, which storage facilities comprise sealed and thermally insulated film tanks. In particular, the application relates to the field of sealed and thermally insulated tanks for storing and/or transporting liquefied gases at low temperatures, such as tanks for transporting liquefied petroleum gas (liquefied petroleum gas, GPL) at temperatures between-50 ℃ and 0 ℃ for example, or tanks for transporting liquefied natural gas (liquefied natural gas, GNL) at about-162 ℃ at atmospheric pressure. These tanks may be installed on land or on floating structures. In a floating structure, a tank may be used to transport or receive liquefied gas that is used as fuel to drive the floating structure.

Background

Document FR2991430 describes a storage facility for liquefied gases comprising a sealed and thermally insulated tank built into a carrying structure comprising a double hull of a ship. Each wall of the tank comprises a secondary insulation barrier, a secondary sealing film, a primary insulation barrier and a primary sealing film.

At the top of the tank there is an overhanging shaft-like part called a liquid dome. In this region, the load-bearing structure is locally interrupted to define a load/unload opening to be traversed by the fluid load/unload line. The loading/unloading opening, known as a liquid dome, comprises a thermal insulation or barrier, and elements forming a primary sealing film.

It is desirable to reduce the production costs of such liquid domes, in particular by using lower cost materials, which however have properties that may not be well suited for the tank and the very low temperatures to which such liquid domes are subjected. Furthermore, tanks are installed in structures (such as ships) that are subjected to very high mechanical stresses, which are particularly detrimental to the structure of the liquid dome, which is relatively narrow and extends vertically like a well above the actual tank containing liquefied gas, where the structure is bent and twisted according to its environmental conditions.

Various experiments and tests have demonstrated that the liquid dome tube can be made of a lower cost metallic material, provided that a specific structure is provided to enable the liquid dome to withstand the high stresses imposed thereon.

Disclosure of Invention

The present application aims at first of all to propose a liquid dome that is low cost but able to withstand all the stresses imposed on it, while ensuring the ideal physical and thermal sealing of the extremely cold fluid contained in the tank.

The application thus relates to a storage facility for liquefied gas, comprising a carrier structure and a sealed and thermally insulated tank arranged inside said carrier structure,

the sealed and thermally insulating tank having a main structure formed by a plurality of tank walls connected to each other and fastened to the carrying structure, the main structure defining an internal storage space, the main structure comprising at least one sealing film and at least one thermally insulating barrier positioned between the sealing film and the carrying structure,

the load bearing structure has a generally planar upper load bearing wall,

the sealing film, the thermal insulation barrier of the body structure and the upper load-bearing wall are locally interrupted to define a conduit forming a load-bearing wall of a hoistway extending along a vertical axis to an upper end comprising a loading/unloading opening for passage of a fluid loading/unloading line, wherein the tank has a lid arranged in the loading/unloading opening, and wherein the lid comprises an upper lid wall, a lower lid wall and a thermal insulation structure between the lower lid wall and the upper lid wall.

The application is characterized in that the pipe and the upper cover wall are made of different iron-based alloys and at least one first fastening lug protruding from the upper cover wall is sealingly fastened to the sealing film.

Tests and analyses have shown that low cost carbon steel tubing can be used provided that a special construction is implemented to firmly secure the primary sealing film of the liquid dome while having a degree of freedom to absorb thermal expansion.

The present application thus saves a great deal of money in the construction of the liquid dome while ensuring or maintaining a perfect seal of the liquefied gas and excellent mechanical strength of the liquid dome against all stresses to which this area is normally subjected.

The term "pipe" means that the element forms the outer wall of the liquid dome, more precisely the wall of the shaft forming the opening in the tank containing the liquefied gas. The term "well" refers to the general shape of a liquid dome, which well extends vertically from the interior space of the tank itself.

Conventionally, the terms "exterior" and "interior" are used to determine the relative position of one element with respect to another element with reference to the interior and exterior of the tank.

Other advantageous features of the application are briefly listed below:

advantageously, the sealing film comprises, from the inside of the internal storage space or the pipe to the outside of the tank: a primary film followed by a secondary film, and at least one second fastening tab projecting from the upper cover wall is sealingly fastened to the secondary film.

In this embodiment, preferably, but not exclusively, the first and second fastening lugs are independent of each other.

Thus, not only the first fastening tab is sealingly connected to the primary sealing film of the liquid dome, but also the second fastening tab is connected to the heat insulating sealing structure, in this case to the second sealing film. This configuration enables the main body structure of the tank to be firmly and flexibly fastened to the upper wall of the cap, which cap and its fastening lugs are made of a material that is particularly resistant to mechanical and thermal forces.

Advantageously, the first fastening tab and/or the second fastening tab have an L-shaped cross section and a linear proximal portion extending from the upper cover wall through a distal portion extending from the proximal portion at an angle of 90±10°, the primary sealing film or secondary sealing film, respectively, being fastened to the proximal portion.

According to a preferred embodiment, the distal end portion of the first fastening lug and/or the second fastening lug has a Γ -shaped or C-shaped profile. Such a cross section provides an advantageous degree of elasticity for the first fastening tab and also advantageously for the second fastening tab, which would otherwise be made of a material having inherently low elastic mass but excellent mechanical and thermo-mechanical strength properties.

According to a preferred embodiment of the application, a structural heat shield is arranged between the first and second fastening lugs, the structural heat shield having a heat resistance of at least 200 ℃, preferably at least 120 ℃, and more particularly at least 80 ℃, and preferably being arranged between the second fastening lugs and the pipe.

Thus, when the operator performs a weld at or near the upper wall of the cover, the first and possibly the second fastening lugs contribute to thermally protecting the insulation itself, which has heat resistant properties. Thus, the insulation at the connection between the body structure of the tank and the liquid dome cover is less likely to be damaged during assembly of the liquid dome and its different components.

Thus, according to an advantageous embodiment, the heat resistant structural insulation comprises:

glass wool or polyurethane foam surrounded by a structural covering providing thermal protection,

glass wool or polyurethane foam surrounded by a plurality of plywood spacers providing thermal protection,

plywood boxes containing glass wool or polyurethane foam providing thermal protection,

plywood boxes comprising glass wool or polyurethane foam at least partially surrounded by ceramic fibre, aluminium or steel coverings,

glass wool or polyurethane foam surrounded by a plurality of plywood spacers comprising at least partly ceramic fibre, aluminium or steel coverings.

In the context of the present application, the expression "structural insulation" resistant to heat is understood to mean that such insulation has mechanical strength characteristics against pressure and all stresses normally applied thereto, so that the insulation has very significant resistance to breakage, with little or no plastic deformation. For example, such structural insulation is capable of withstanding pressures of at least 1MPa (megapascals). In contrast, unstructured insulation does not possess these mechanical strength characteristics or qualities.

The exemplary embodiments listed above are not exhaustive, but such insulation must have at least one, preferably at least two, and even more preferably all of the following technical functions, in descending order of importance:

insulation to withstand the heat generated by the welding,

sufficiently mechanically structural to be installed and secured in a designated space,

insulation to keep the cargo at a low temperature,

-the influence of reflected radiation.

The actual elements of the embodiments of the structural insulation may be combined with specific welding methods, in particular cold inert gas injection during welding and/or external heat sinks during copper bar welding.

Advantageously, the lower cover wall is not fastened or connected to the first fastening lug. In other words, in this case, the lower cover wall is positioned at a distance from the end of the first fastening lug opposite the upper cover wall.

Preferably also with respect to this feature, the lower cover wall is not made of metal or metal-based alloy, and the lower cover wall is preferably made of plywood. Indeed, after analysing the specific technical background of the application, the applicant has noted that the lower cap wall does not need to have sealing properties with respect to the fluid contained in the tank.

Advantageously, the pipe is made of an iron-based alloy comprising, by weight: 0% < C <0.21%, 0% < Mn <1%, 0% < Si <0.5%, 0% < P <0.035% and 0% < S <0.035%, the remainder being iron and impurities necessarily produced in the manufacture of the alloy.

Preferably, the pipeline is made of A, B, D, AH, DH, EH, FH or grade E steel according to international bulk transport liquefied gas vessel construction and equipment rules (International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk, IGC) well known to those skilled in the art.

Advantageously, the upper cover wall and the first and optionally the second fastening lugs are made of an iron-based alloy comprising austenitic steel having by weight: 0< C <0.08%, 0% < Mn < 2%, 0% < Si <0.5%, 0% < P <0.045%, 0% < S <0.030%, 8% < Ni <14%, 16% < Cr <50%, 0% < N <0.02%, optionally 0% < Mo < 3% and/or 0% < Ti <0.7%, the remainder being iron and impurities necessarily produced in the manufacture of said alloy.

Conventionally, the following elements of the periodic table are taken into account:

c: carbon, mn: manganese, cr: chromium, si: silicon, ni: cobalt nickel: cobalt Co, P: phosphorus, O: oxygen, N: nitrogen, mo: molybdenum, S: sulfur, and Ti: titanium.

The present application relates to a vessel for transporting a cold liquid product, said vessel having a double hull and a storage facility as described above arranged in said double hull.

The application also relates to a transfer system for a cold liquid product, the system comprising a vessel as described above, an insulated pipe arranged to connect the tank mounted in the hull of the vessel to an external land or floating storage facility, and a pump for driving a flow of cold liquid product from the external land or floating storage facility to the tank on the vessel or from the tank of the vessel to the external land or floating storage facility through the insulated pipe.

Finally, the application also relates to a method for loading or unloading a vessel as described above, wherein cold liquid product is guided from an external land or floating storage facility to or from the tank on the vessel through an insulated pipeline.

Drawings

The application may be better understood and additional objects, details, features and advantages thereof will be more clearly set forth in the following detailed description of specific embodiments of the application, given by way of non-limiting example only, with reference to the accompanying drawings.

Fig. 1 is a schematic view of an open liquid dome according to one embodiment of the application, wherein both sides or baffles of the pipe and well are visible.

Fig. 2 is an enlarged cross-sectional view of one face of the liquid dome's conduit and well and the liquid dome's cover.

Fig. 3 is a cross-sectional view of the corner between the cap and the pipe and the liquid dome well, particularly showing the first and second fastening lugs.

Fig. 4 is a schematic cross-sectional view functionally illustrating the corner portion between the cap and the tube and the liquid dome well.

Fig. 5 is an enlarged view of the corner portion shown in fig. 4.

Fig. 6 is a schematic view from fig. 1, wherein the first fastening tab and the second fastening tab are particularly visible.

Fig. 7 is a schematic diagram complementary to fig. 6, with components added thereto.

Fig. 8 is a schematic diagram complementary to fig. 6, with components added thereto.

Fig. 9 is a schematic cut-away view of a storage facility in a lng carrier and a loading/unloading terminal for the tank.

Detailed Description

The term "vertical" in this context means extending in the direction of the earth's gravitational field. The term "horizontal" herein refers to extending in a direction perpendicular to the vertical direction.

When the storage facility 1 is located on a vessel, such as a lng carrier, the load bearing structure (not shown in the drawings) is formed by the double hull of the vessel. The upper outer carrier wall 5 is called the outer deck 5 of the vessel.

The tank 71 comprises a main structure consisting of a bottom wall (not shown), a top wall and two cofferdam walls (not shown) connecting the bottom wall to the top wall and being at the front and rear when the storage facility 1 is located in a vessel, two side walls (not shown) connecting the side walls to the bottom wall or the top wall, and optionally two to four ramp walls (not shown). The walls of the tank 71 are thereby connected to each other to form a polyhedral structure and define the internal storage space 9.

For loading and unloading the tank 71 with liquefied gas, the storage facility 1 comprises a loading/unloading opening 10, which loading/unloading opening 10 locally interrupts the upper outer carrier wall 5, the upper inner carrier wall and the top wall of the tank 71, in particular to enable a loading/unloading line (not shown in the figures) to pass through this opening 10 to the bottom of the tank 71.

The storage facility 1 further comprises a loading/unloading tower (not shown in the figures) located horizontally to the opening 10 and inside the tank 71 to form a loading/unloading line for the whole height of the tank 71 and a carrying structure for a pump (not shown).

Furthermore, the storage facility 1 has a cover 12 arranged in the loading/unloading opening 10 to close the internal storage space at said opening 10. The cover 12 includes an aperture for passing a load/unload line through the cover 12.

The tank 71 has at the opening a well 15 on the main structure, so that the tank wall can extend continuously from the inner deck to the outer deck 5 at the point where the wall is interrupted by the loading/unloading opening 10. In a liquefied gas tank, the well 15 provided with the cover 12 is called a liquid dome.

The loading/unloading opening 10 and the hoistway 15 have a generally rectangular profile. The hoistway 15 thus comprises four walls, one wall being an extension of the rear cofferdam wall 8 (as shown in fig. 1), while the other three walls are connected to the top wall to form an angle of 90 ° with the top wall.

According to the application, a cover 12 is located on the outer deck 5 to close the hoistway 15. The tank 71 is a thin film tank 71 for storing liquefied gas. The main structure of the tank 71 has a multilayer structure comprising, from the outside inwards, a secondary insulation barrier 16, a secondary sealing film 17, a primary insulation barrier 18, a primary sealing film 19, wherein the secondary insulation barrier 16 comprises an insulation element against the load-bearing structure, the secondary sealing film 17 against the secondary insulation barrier 16, the primary insulation barrier 18 comprises an insulation element against the secondary sealing film 17, the primary sealing film 19 being designed to be in contact with the liquefied gas contained in the tank 71.

According to one embodiment, the main structure of tank 71 uses MarkTechnical manufacture, which is described in particular in document FR 2691520A.

In this main structure, the secondary insulation barrier 16, the primary insulation barrier and the secondary sealing film 17 are generally panels juxtaposed on a load bearing structure, which may be an inner load bearing structure or a structure connecting an upper inner load bearing wall to an upper outer load bearing wall 5 at the opening 10. The secondary sealing film 17 is made of a composite material comprising an aluminum sheet sandwiched between two sheets of fiberglass fabric. The primary sealing film 19 is obtained by assembling a plurality of metal plates welded together along their edges and having flutes extending in two perpendicular directions. These metal plates are made of, for example, stainless steel or aluminum plates by bending or press forming. The primary sealing film 19 is shown in particular in fig. 3 and 4.

Further details of such fluted metal films are described in particular in FR2861060 a.

In the well 15, the upper end of the primary sealing film 19 is fastened to the fastening lugs 50 and, more specifically, to the distal end portions 52 of said fastening lugs 50. The connection between the fastening lugs 50 and the primary film 19 is advantageously formed by sealing welding, or possibly by gluing.

The lid 12 further comprises a multi-layer structure comprising, from outside to inside, an upper lid wall 23, a lower lid wall 22, and an insulating structure 24 between the lower lid wall 22 and the upper lid wall 23. The cover 12 also has a stiffening member 25 located on the upper cover wall 23.

The cover 12 is arranged in the loading/unloading opening 10 such that the upper cover wall 23 is arranged in the plane of the upper outer carrying wall 5 or the outer deck 5. Thus, in this case, the storage facility 1 does not have a dome base, and the cover 12 does not protrude above the outer deck 5.

The upper cover wall 23 is sealingly fastened to the outer deck 5 around the entire opening 10, such that the upper cover wall 23 acts as a secondary sealing membrane 17 at the cover 12 or more simply as a sealing membrane, as the applicant has determined the feasibility of using a single sealing membrane in the cover 12. The upper cover wall 23 is made of a metallic material, such as stainless steel.

According to an important aspect of the application, the lower cover wall 22 is advantageously made of a non-metallic material or a metallic alloy. Indeed, the applicant has determined that such a wall 22 does not necessarily have to be a sealing film. Furthermore, the lower cover wall 22 is advantageously made of plywood, but the wall 22 may also be made of plastic or a composite material (e.g. a "sandwich" structure), preferably of thermosetting plastic, provided that the material can mechanically and chemically withstand simple contact with the cold fluid contained in the tank 71.

As shown in fig. 4 and 5, there is no connection between the lower cover wall 22 and the first fastening lugs 50 or the primary sealing film 19. Thus, there may be an opening or gap between the lower cap wall 22 and the primary sealing film 19. Also, the applicant has determined that no connection is required between the lower cap wall 22 and the primary sealing film 19.

The insulating structure 24 of the cover 12 includes a plurality of insulating elements juxtaposed with one another, which may be of similar or different construction. In a preferred embodiment, these insulation elements that are flush with the lower cover wall 22 are structural insulation elements, while the insulation elements positioned around the insulation structure 24 (i.e., without the insulation elements between the walls 22 and 23) are non-structural insulation elements. Of course, structural insulating elements may also be provided between walls 22 and 23 if required to take into account the mechanical stresses of the assembly. The structural insulating element may be a high density polymer foam block (optionally reinforced with fibers) or plywood or a composite box filled with an insulating filler such as glass wool or perlite. The non-structural insulating element may be a block of low density polymer foam or glass wool.

However, an important aspect of the application relates to the insulation 40, 41, which is arranged between:

first of all, arranged between the first fastening lug 50 and the second fastening lug 55, called insulation 40, and

second, between the second fastening lug 55 and the duct 30, referred to as insulation 41.

The insulation 40, 41 is a structural insulation. Furthermore, the insulation 40, 41 is heat resistant to temperatures of at least 200 ℃ (degrees celsius), preferably to temperatures of at least 80 ℃. This means that the mechanical properties of the insulation 40, 41 do not change or hardly change when exposed to such temperatures. The insulation 40, 41 of the type and function possible above is therefore essentially completely resistant to the high temperatures caused by the welding work performed nearby. Of course, as mentioned above, the welding work may be accompanied by measures, in particular thermal protection of the insulation 40, 41 during welding, in particular by injecting cold inert gas during welding and/or by providing an external heat sink during welding of the copper bars.

The fastening lugs 50 extend vertically from the upper cover wall 23 and comprise a vertical proximal portion 51 and a distal portion 52, which distal portion 52 extends substantially horizontally, or which distal portion 52 in this case forms a C-hook, however the distal portion 52 may also have a Γ -profile. The fastening lugs 50 are advantageously made of the same material as the upper cover wall 23. Thus, the fastening lugs 50 are made of a metallic material (typically an iron-based alloy) that has better mechanical strength than conventional carbon steel (such as the carbon steel of the pipe 30) when the ambient temperature is substantially below 0 ℃, or even equal to or less than-40 ℃.

Another important aspect of the application is to have a second fastening tab 55 also protruding from the wall 23, which second fastening tab 55 is used for sealingly fastening the second sealing film 17. It is therefore within the scope of the application for each of the two sealing films 17, 19 to have an independent sealing connection with the upper cover wall 23 by means of a particularly advantageous fastening lug 50, 55, wherein this fastening lug 50, 55 provides a high mechanical strength and a degree of flexibility, so that said lug can easily absorb the various thermo-mechanical stresses present in very specific areas, i.e. liquid domes.

As with the first fastening tab 50, the second fastening tab 55 includes a proximal portion 56 and a distal portion 57, the distal portion 57 extending from the proximal portion 56, wherein the second sealing film 17 is fastened to the distal portion 57. The distal portion 57 of the second fastening lug 55 has a C-shaped hooked profile, but the distal portion 52 may also have a Γ -profile. The distal portion 57 is advantageously identical or can be identical in shape and/or size to the distal portion 52 of the first fastening tab 50.

Advantageously, the proximal portion 56 of the second fastening tab 55 is at least twice as long as the proximal portion 51 of the first fastening tab 50. This feature makes the connection of the wall 23 to the secondary sealing film 17 more rigid than the connection of the wall 23 to the primary sealing film 19, i.e. provides a greater flexibility in the connection between the wall 23 and the secondary sealing film 17 than the connection between the wall 23 and the primary sealing film 19. In general, it is important that proximal portion 56 be longer than proximal portion 51 to enable assembly.

It should be noted here that the application mainly relates to the first fastening lug 50 and its direct connection to the primary sealing film 19. Thus, in an alternative embodiment (not shown in the drawings), there is no second fastening tab 55, and the fastening tab 50 additionally includes an arm or flange to sealingly fasten the fastening tab 50 to the second sealing film 17.

The upper cover wall 23 and the fastening lugs 50, 55 may be made of 300 series stainless steel approved by the IGC regulations. In other words, the fastening lugs 50, 55 are made of austenitic steel according to astm a 240.

The application is based firstly on the fact that the presence of the first fastening lugs 50 and possibly the second fastening lugs 55 enables the pipe 30 of the shaft 15 forming the liquid dome to be made of carbon steel, in particular of grade A, B, D, AH, DH, EH, FH or E steel according to ASTM standard a 131. When the ambient temperature drops significantly below 0 ℃, the resistance or elasticity of this steel grade is lower, which may be or is determined to be at risk in the liquefied gas tank, but these steels are much lower cost than stainless steel.

Thus, this configuration reduces the amount of expensive stainless steel in the liquid dome and provides flexibility for the primary anchor (i.e., primary sealing membrane 19 at opening 10 of the liquid dome) and the secondary anchor (i.e., secondary sealing membrane 17).

The main aspect of the application is thus the connection and fastening of the primary sealing film 19 of the liquid dome with the fastening lugs 50, and advantageously the connection and fastening of the secondary sealing film 17 of the liquid dome with the fastening lugs 55.

Furthermore, as previously mentioned, these fastening lugs 50, 55 are offset from the conduit 30 of the well 15 of the liquid dome by at least a few centimeters, i.e. by a distance of between 5 and 60cm, preferably between 15 and 40cm, from the pipe 30. This offset of the fastening lugs 50, 55 relative to the pipe 30 provides a flexible fastening of the membranes 17, 19 so that the assembly can easily withstand significant mechanical stresses, knowing that when the structure carrying the tank 71 is a ship, the region of the well 15 that is much smaller or narrower than the tank 71 and vertically arranged liquid dome concentrates strong mechanical stresses and strains.

As shown in the figures, the offset of the fastening lugs 50 from the conduit 30 reduces the need for structural insulation, which is more expensive and more difficult to deploy than other non-structural insulation. Only structural insulation 40, 41, respectively, is required to be disposed between the fastening lugs 50, 55 and the spacer 30.

Thus, the amount of structural insulation may be reduced in the liquid dome structure according to the present application compared to a conventional liquid dome that does not include the fastening lugs 50 and may not include the fastening lugs 55.

Fig. 9 shows an exemplary marine terminal comprising a loading/unloading point 75, a subsea pipeline 76 and an onshore facility 77. The loading/unloading point 75 is a fixed offshore facility that includes a movable arm 74 and a mast 78 that supports the movable arm 74. The movable arm 74 carries a series of insulating hoses 79, which insulating hoses 79 can be connected to the load/unload tube 73. The orientable movable arm 74 can be adjusted to accommodate all sizes of lng carrier. A connecting line (not shown) extends inside the strut 78. The loading/unloading site 75 may allow the lng carrier 70 to be loaded into the onshore facility 77 or unloaded from the onshore facility 77. The facility has a liquefied gas tank 80 and a connection line 81 connected to the loading/unloading point 75 via a subsea line 76. The underwater line 76 enables the transfer of liquefied gas between the loading/unloading point 75 and the onshore facility 77 over a long distance (e.g., 5 km), which enables the liquefied gas carrier 70 to be maintained at a long distance from shore during loading and unloading operations.

To generate the pressure required to deliver the liquefied gas, pumps carried on the ship 70 and/or mounted on land facilities 77 and/or mounted at the loading/unloading point 75 are used.

While the application has been described in connection with a number of specific embodiments, it will be apparent that the application is not limited thereto, and that the application is intended to include all technical equivalents of the described components and combinations thereof, insofar as such equivalents fall within the scope of the application.

Use of the verb "comprise" or "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

Claims (15)

1. Storage facility (1) for liquefied gas, comprising a carrying structure and a sealed and thermally insulated tank (71) arranged within said carrying structure,

the sealed and thermally insulating tank (71) having a main structure formed by a plurality of tank walls connected to each other and fastened to the carrying structure, the main structure defining an internal storage space, the main structure comprising at least one sealing film (17, 19) and at least one thermally insulating barrier (16, 18), the thermally insulating barrier (16, 18) being positioned between the sealing film (17, 19) and the carrying structure,

the load bearing structure has a generally planar upper load bearing wall,

the sealing film (17, 19), the heat insulating barrier (16, 18) of the main structure and the upper carrier wall are locally interrupted to define a pipe (30) forming a carrier wall of a well (15) extending along a vertical axis to an upper end comprising a loading/unloading opening (10) for being traversed by a fluid loading/unloading line, wherein the tank (71) has a lid (12) arranged in the loading/unloading opening (10), and wherein the lid (12) comprises an upper lid wall (23), a lower lid wall (22) and a heat insulating structure (24) between the lower lid wall (22) and the upper lid wall (23),

characterized in that the duct (30) and the upper cover wall (23) are made of different iron-based alloys and at least one first fastening lug (50) projecting from the upper cover wall (23) is sealingly fastened to the sealing film (19).

2. The storage facility (1) according to claim 1, wherein the sealing film (17, 19) comprises, from the interior of the interior storage space or the conduit (30) to the exterior of the tank (71): a primary film (19) and a subsequent secondary film (17), and at least one second fastening lug (55) projecting from the upper cover wall (23) is sealingly fastened to the secondary film (17).

3. The storage facility (1) according to claim 2, wherein the first fastening lug (50) and the second fastening lug (55) are independent from each other.

4. A storage facility (1) according to claim 2 or 3, wherein the first fastening lug (50) and/or the second fastening lug (55) have an L-shaped cross section and a linear proximal portion (51), the linear proximal portion protruding from the upper cover wall (23) extending through a distal portion (52) extending from the proximal portion (51) at an angle of 90±10°, the primary sealing film or secondary sealing film, respectively, being fastened to the proximal portion.

5. Storage facility (1) according to claim 4, wherein the distal end portion of the first fastening lug and/or the second fastening lug has a Γ -shaped or C-shaped profile.

6. Storage facility (1) according to any one of claims 2 to 5, wherein a structural insulation is provided between the first fastening lug (50) and the second fastening lug (55), the structural insulation having a heat resistance of at least 200 ℃, preferably at least 80 ℃, and preferably the structural insulation is provided between the second fastening lug and the pipe (30).

7. The storage facility (1) according to claim 6, wherein the structural insulation that is resistant to heat comprises:

o glass wool or polyurethane foam surrounded by a structural covering that provides thermal protection,

o glass wool or polyurethane foam surrounded by a plurality of plywood spacers providing thermal protection,

o plywood boxes containing glass wool or polyurethane foam to provide thermal protection,

o a plywood box comprising glass wool or polyurethane foam at least partially surrounded by a ceramic fibre, aluminium or steel cover,

o glass wool or polyurethane foam surrounded by a plurality of plywood spacers comprising at least in part ceramic fibers, aluminum or steel coverings.

8. Storage facility (1) according to any of the preceding claims, wherein the lower cover wall (22) is not fastened or connected to the first fastening lug.

9. Storage facility (1) according to any one of the preceding claims, wherein the lower cover wall (22) is not made of metal or metal-based alloy, and the lower cover wall (22) is preferably made of plywood.

10. The storage facility (1) according to any one of the preceding claims, wherein the pipe (30) is made of an iron-based alloy comprising by weight: 0% < C <0.21%, 0% < Mn <1%, 0% < Si <0.5%, 0% < P <0.035% and 0% < S <0.035%, the remainder being iron and impurities necessarily produced in the manufacture of the alloy.

11. The storage facility (1) according to claim 10, wherein the pipeline (30) is made of A, B, D, AH, DH, EH, FH or grade E steel according to IGC regulations.

12. The storage facility (1) according to any one of the preceding claims, wherein the upper cover wall (23) and the first fastening lugs (50) and optionally the second fastening lugs (55) are made of an iron-based alloy comprising austenitic steel having by weight: 0< C <0.08%, 0% < Mn < 2%, 0% < Si <0.5%, 0% < P <0.045%, 0% < S <0.030%, 8% < Ni <14%, 16% < Cr <50%, 0% < N <0.02%, optionally 0% < Mo < 3% and/or 0% < Ti <0.7%, the remainder being iron and impurities necessarily produced in the manufacture of said alloy.

13. Vessel (70) for transporting a cold liquid product, the vessel having a double hull (72) and a storage facility (1) according to any of claims 1 to 12 placed within the double hull.

14. A transfer system for cold liquid products, the system comprising a vessel (70) according to claim 13, insulated piping (73, 79, 76, 81) arranged to connect the tank (71) installed in the hull of the vessel to an external land or floating storage facility (77), and a pump for driving a flow of cold liquid product from the external land or floating storage facility to the tank on the vessel or from the tank of the vessel to the external land or floating storage facility through the insulated piping.

15. Method for loading or unloading a vessel (70) according to claim 13, wherein cold liquid product is guided from an external land or floating storage facility (77) to the tank (71) on the vessel or from the tank of the vessel to the external land or floating storage facility by means of the insulated pipelines (73, 79, 76, 81).