Leak-proof insulated container walls

Abstract

The invention relates to a wall (11) of a leak-proof, insulated container for storing liquefied gas, said wall (11) comprising, successively in a thickness direction from the outside to the inside of said container, a leak-proof outer barrier (13), an insulating barrier (14) and a leak-proof inner barrier (15), said insulating barrier (14) having a gas phase with an absolute pressure of less than 1 Pa, - a radiant multi-layer insulating cover (47) extending perpendicularly to said thickness direction, said radiant multi-layer insulating cover (47) being made of metal or of a polymer material coated with metal and comprising a stack of a plurality of sheets separated from each other by fiber layers, - an insulating element (51) arranged between said radiant multi-layer insulating cover (47) and said leak-proof outer barrier (13) and having an open-cell porous structure.

Description

[Technical field]

[0001] The present invention relates to the field of sealed, insulated tanks, in particular for storing and / or transporting liquefied gases, such as liquid hydrogen at atmospheric pressure at about -253°C. [Background technology]

[0002] Tanks for storing liquid hydrogen are known in the art, but liquefied gas has the characteristic that its liquefaction temperature is lower than that of liquefied natural gas, and therefore, in order to limit the amount of evaporation of liquid hydrogen, these tanks must have better insulation performance than tanks for storing liquefied natural gas.

[0003] CN113739061 discloses a tank for storing liquid hydrogen, which is composed of an outer storage tank, an inner storage tank, and a multi-layer structure in contact with the inner storage tank, which is composed of, from the outside to the inside, a secondary insulation barrier in contact with the inner storage tank, a secondary sealing membrane in contact with the secondary insulation barrier, a primary insulation barrier in contact with the secondary sealing membrane, and a primary sealing membrane in contact with the primary insulation barrier.

[0004] To further improve the thermal insulation performance of the tank, the space between the outer tank and the inner tank is depressurized to, for example, 10 absolute pressure. -3 In addition, a composite reflective screen made of multiple aluminum sheets can be placed on the outer surface of the inner tank to reduce heat transfer from the outside to the inside of the tank due to thermal radiation.

[0005] Such liquid hydrogen storage tanks are not necessarily satisfactory. Specifically, if the sealing of either the inner or outer storage tank is lost and the reduced pressure level of the space formed between these two storage tanks is compromised, the insulating performance of the liquid hydrogen storage tank may be significantly reduced.

[0006] Furthermore, the composite reflective screen is still located in a space subject to significant temperatures, and therefore significant radiant flux, thereby limiting its effectiveness.

[0007] Finally, the storage tank has a complex structure, since it has a multi-layer structure consisting of two insulating barriers and two sealing membranes, as well as a vacuum space between the inner and outer tanks. Summary of the Invention

[0008] One of the ideas behind the present invention is to propose a wall for a sealed, insulated tank, which has improved insulating properties even under adverse conditions, such as when one of the sealing barriers becomes unsealed.

[0009] According to one embodiment, the present invention relates to a wall of a sealed, insulated tank for storing liquefied gas, said wall comprising, successively in a thickness direction from the outside to the inside of the tank, an outer sealing barrier, an insulating barrier and an inner sealing barrier, said insulating barrier having a gas phase with an absolute pressure of less than 1 Pa, - a radiant multi-layer insulation covering extending perpendicular to said thickness direction, said radiant multi-layer insulation covering comprising a stack of sheets made of a metal or a metal-coated polymeric material and separated from one another by a fibrous layer; an insulating element having an open cell porous structure, the insulating element being disposed between the radiant multi-layer insulating cover and the outer sealing barrier.

[0010] The aforementioned structure of the insulating barrier thus confers excellent insulating properties even in the event of a deterioration of the vacuum. Indeed, the insulating element limits the flow of heat through the insulating barrier, especially when the pressure in the insulating barrier is higher than the prescribed pressure value. Moreover, the insulating element further reduces the temperature of the insulating barrier area in which the radiant multilayer insulating cover is located, increasing its efficiency. Moreover, the insulating element also limits the flow of heat by convection through the insulating barrier. Finally, since the reduced pressure is generated directly in the gas phase of the insulating barrier, and not in the space of the insulating element covered by a fluid-tight wrapper, a fluid-tight wrapper that is prone to form conductive thermal bridges can be dispensed with.

[0011] The expression "thermal insulation element with an open-cell porous structure" means an insulating material or component having empty cavities, also called cells, interconnected with each other and with the outside.

[0012] According to embodiments, such a wall may have one or more of the following characteristics:

[0013] According to one embodiment, the radiant multi-layer insulation cover is made of MLI type material, where MLI stands for multi-layer insulation.

[0014] According to one embodiment, the insulating barrier is -1 Pa or less, preferably 10 -2 Less than Pa, e.g. 10 -3 It has a gas phase of about Pa. This makes it possible to further improve the thermal insulation performance of the thermal insulation barrier.

[0015] According to one embodiment, said inner sealing barrier is intended to be in contact with the liquefied gas contained in the tank, which allows optimizing the effectiveness of the radiant multi-layer insulation cover, since it is exposed to the lowest temperature, in other words, the emissivity of each layer is reduced, since it is located on the lowest side of the temperature gradient.

[0016] According to one embodiment, the cumulative volume of the cells of the insulating element occupies at least 85% of the volume of the insulating element, preferably 90% or more, more preferably 95% or more.

[0017] According to one embodiment, the thermal conductivity of the insulating element is greater than or equal to 10 mW m when the insulating element is placed under a negative air pressure relative to a reference pressure of 1 bar at 20°C in absolute pressure. -1 ·K -1 less than 6mW m -1 ·K -1 The following is the result.

[0018] According to one embodiment, the average size of the cells or cavities of the insulating element is less than or equal to 3 mm, preferably less than or equal to 1 mm.

[0019] According to one embodiment, the insulating element is selected from glass wool, rock wool, polyester wadding, and open cell polymer foams, such as open cell polyurethane foams and melamine foams.

[0020] According to one embodiment, the radiant multi-layer insulation cover is arranged in a plane closer to the inner sealing barrier than to the outer sealing barrier, which allows to further optimize the effectiveness of the radiant multi-layer insulation cover, since such an arrangement ensures that the majority of the elements exposed to a higher temperature than the inner sealing barrier do not emit a radiant flux directly to the inner sealing barrier.

[0021] According to one embodiment, the primary insulation barrier comprises several orthogonal radiant multi-layer insulation covers in the thickness direction, each of which comprises a stack of multiple sheets made of metal or metal-coated polymeric material and separated from each other by a fibrous layer.

[0022] According to one embodiment, the thermal insulation barrier comprises two radiant multi-layer insulation covers, preferably spaced apart by a distance of 30-160 mm.

[0023] According to one embodiment, the fibrous layer of the radiant multi-layer insulation covering is manufactured using fibers selected from polymeric fibers, such as polyester fibers, and glass fibers.

[0024] According to one embodiment, said sheet made of metal or metal-coated polymeric material is made of a material selected from aluminium, silver, aluminium-coated polymeric material and silver-coated polymeric material.

[0025] According to one embodiment, the aluminum or silver coated polymeric material is selected from polyimide or poly(ethylene terephthalate).

[0026] According to one embodiment, the gas phase in the primary insulating barrier comprises at least 50% by volume, preferably at least 75% by volume, of an inert gas having an anti-sublimation temperature higher than the liquefaction temperature of the liquefied gas intended to be stored in the tank when the primary insulating barrier is packed at room temperature, which allows the use of a cryopump to reduce the pressure in the primary insulating barrier, especially when the liquefied gas stored in the tank is liquid hydrogen.

[0027] According to one embodiment, the inert gas is carbon dioxide.

[0028] According to one embodiment, the insulation barrier comprises a load-bearing element extending in the thickness direction between the outer sealing barrier and the inner sealing barrier, and the radiant multi-layer insulation cover is provided with an opening through which the load-bearing element passes.

[0029] According to one embodiment, the insulating barrier further comprises at least one retaining member fixed to the load-bearing element so as to limit movement of the insulating element in the direction of the inner containment barrier.

[0030] According to one embodiment, the at least one retaining member includes a fibrous retaining layer secured to the load bearing element and disposed between the insulation element and the radiant multi-layer insulation covering.

[0031] According to one embodiment, the radiant multi-layer insulation cover is secured to a fabric retaining layer, which ensures the placement of the radiant multi-layer insulation cover within the insulating barrier.

[0032] According to one embodiment, said textile support layer is manufactured using fibers selected from polymeric fibers and glass fibers.

[0033] According to one embodiment, the thickness of the insulation element is less than the distance in the thickness direction between the outer sealing barrier and the radiant multi-layer insulation cover.

[0034] According to one embodiment, the inner sealing barrier is a primary sealing membrane intended to be in contact with the liquefied gas in the tank, the insulating barrier is a primary insulating barrier and the outer sealing barrier is a secondary sealing membrane, the wall further comprising a secondary insulating barrier supported by a load-bearing structure and supporting the secondary sealing membrane.

[0035] In embodiments where the thermal insulation barrier comprises a plurality of radiant multi-layer insulation covers, preferably the insulating element having a porous structure is disposed between the outermost radiant multi-layer insulation cover and the secondary sealing membrane.

[0036] According to one embodiment, the primary sealing membrane comprises a first corrugation row having first corrugations parallel to each other and a second corrugation row having second corrugations parallel to each other and perpendicular to the first corrugations, the primary sealing membrane comprises a plurality of flat regions defined between two adjacent first corrugations and between two adjacent second corrugations, respectively, the primary insulating barrier comprises at least a first row of load bearing elements including at least first, second and third load bearing elements fixed to the secondary insulating barrier and extending in the thickness direction, successively in a direction parallel to the first corrugations, the first, second and third load bearing elements being fixed to first, second and third inner plates, respectively, the plurality of flat regions including first, second and third flat regions welded to the first, second and third inner plates, respectively, successively in a direction parallel to the first corrugations. Due to these features, the three load-bearing elements are not fixedly connected to each other but form three separate support structures, each supporting a flat area of ​​the primary sealing membrane, thereby providing an appropriate stress distribution between the corrugations of the primary sealing membrane, more specifically between the corrugations on either side of the first, second and third flat areas.

[0037] The modifier "successively" means "one after the other." Thus, "at least a first row of load-bearing elements including at least a first, a second, and a third load-bearing element in succession in a direction parallel to the first corrugation" means that no other load-bearing elements of the first row are interposed between the first and second load-bearing elements or between the second and third load-bearing elements. Similarly, "the plurality of flat regions include ~ a first, a second, and a third flat region in succession in a direction parallel to the first corrugation" means that no other flat region is interposed between the first and second flat regions or between the second and third flat regions.

[0038] According to one embodiment, the first and second flat regions are separated from each other by a second corrugation arranged on the opposite side of the thickness to the free space separating the first and second inner plates, and the second and third flat regions are separated from each other by a second corrugation arranged on the opposite side of the thickness to the free space separating the second and third outer plates.

[0039] According to one embodiment, the first, second and third inner plates are in contact with at least 70%, preferably 90%-100% of the surface area of ​​the first, second and third flat areas, respectively, so that the stresses caused by the hydrostatic and dynamic pressures exerted by the liquefied gas on the primary sealing membrane can be distributed over a larger support surface, improving stress distribution.

[0040] According to one embodiment, the primary sealing membrane is composed of a plurality of corrugated metal plates, an edge of each corrugated metal plate is lap welded to an edge of an adjacent corrugated metal plate, and the first, second and third flat areas are formed by two edges of two adjacent corrugated metal plates. In other words, the first, second and third inner plates support and fix the two adjacent edges of the two adjacent corrugated metal plates.

[0041] According to one embodiment, the first, second, and third flats are spot welded to the first, second, and third inner plates, respectively.

[0042] According to one embodiment, the primary insulating barrier comprises at least a second row of load bearing elements including fourth, fifth and sixth load bearing elements secured to the secondary insulating barrier and extending in a thickness direction of the wall, the fourth, fifth and sixth load bearing elements being aligned in a direction parallel to the first corrugations and secured to the fourth, fifth and sixth inner plates respectively, the fourth, fifth and sixth load bearing elements being aligned in a direction parallel to the first, second and third load bearing elements respectively, and the plurality of flat regions including fourth, fifth and sixth flat regions abutting against the fourth, fifth and sixth inner plates respectively. Thus, the primary insulating barrier has both load bearing elements aligned parallel to the first corrugations of the primary sealing membrane and load bearing elements aligned parallel to the second corrugations of the primary sealing membrane.

[0043] According to one embodiment, the fourth, fifth and sixth flat regions are welded to the fourth, fifth and sixth inner plates, respectively.

[0044] According to one embodiment, the fourth, fifth and sixth flat areas are each separated from one of the edges of the corrugated metal plate by at least one first corrugation and one second corrugation, in other words, the flat areas of the primary sealing membrane are also welded to the inner plate on the outside of the edges of the corrugated metal plate, which further improves the stress distribution across the corrugations of the primary sealing membrane.

[0045] According to one embodiment, the fourth, fifth, and sixth flat regions are stake welded to the fourth, fifth, and sixth inner plates, respectively.

[0046] According to one embodiment, each flat portion of the primary sealing membrane abuts a respective inner plate, which is fixed to the secondary insulating barrier and fixed to a respective load-bearing element extending through its thickness, thereby ensuring uniform stress distribution across the corrugations of the entire primary sealing membrane.

[0047] According to one embodiment, the first, second and third load-bearing elements are fixed to the first, second and third outer plates, respectively, which are fixed to the secondary insulating barrier and press the secondary sealing membrane against the secondary insulating barrier. The outer plates thus have a dual function: firstly, they secure the load-bearing elements to the secondary insulating barrier and secondly, they prevent the secondary sealing membrane from tearing, especially when the pressure in the secondary insulating barrier is higher than the pressure in the primary insulating barrier.

[0048] According to one embodiment, the secondary sealing membrane comprises a first corrugation row having first corrugations parallel to each other and a second corrugation row having second corrugations parallel to each other and perpendicular to the first corrugations, the secondary sealing membrane having a plurality of flat areas respectively defined between two adjacent first corrugations and between two adjacent second corrugations of the secondary sealing membrane, and each of the first, second and third outer plates is pressed against one of the flat areas of the secondary sealing membrane.

[0049] According to one embodiment, the first, second and third outer plates each contact more than 70%, preferably 90%-100% of the surface area of ​​the corresponding flat region of the secondary sealing membrane, thereby distributing the stress transmitted by the load bearing element over a larger surface area of ​​the secondary sealing membrane, improving stress distribution.

[0050] According to one embodiment, the first and second rows of corrugations of the secondary sealing membrane are opposite in the thickness direction to the first and second rows of corrugations of the primary sealing membrane, respectively.

[0051] According to one embodiment, the first, second and third outer plates are fixed to the first, second and third load bearing elements, respectively, by riveting.

[0052] According to one embodiment, each of the first, second, and third outer plates is secured to the second insulating barrier by a primary anchoring device, the first anchoring device being secured to an insulating panel of the second insulating barrier and including a pin passing through an orifice in the second sealing membrane and an orifice in one of the first, second, and third outer plates, the pin having a radially extending flange welded to the secondary sealing membrane around the orifice in the secondary sealing membrane, the primary anchoring device further comprising a nut threaded onto the pin to hold the first, second, or third outer plate against the secondary sealing membrane.

[0053] According to one embodiment, the load-bearing elements, in particular the first, second and third load-bearing elements mentioned above, each comprise an outer base, an inner base and a post, each of the outer base and the inner base having a sleeve to which one end of the post is attached and a support flange extending radially from one end of the sleeve.

[0054] According to one embodiment, each end of the post is fitted into one of the sleeves. According to another variant, each sleeve is fitted into one of the ends of one of the posts.

[0055] According to another embodiment, the post, the outer base, and the inner base are integral.

[0056] According to one embodiment, the support flange of the inner base abuts and is fixed to one of the inner plates.

[0057] According to one embodiment, the support flange of the outer base abuts and is fixed to one of the outer plates.

[0058] According to one embodiment, each post is fixed to the inner base and the outer base, for example by gluing.

[0059] According to one embodiment, each pillar is made of a fiber-matrix composite material that provides sufficient compressive strength for the limited conductive section.

[0060] According to one embodiment, the fibers may be glass fibers, carbon fibers, aramid fibers, flax fibers, basalt fibers, or mixtures thereof.

[0061] According to one embodiment, the matrix may be polyethylene, polypropylene, poly(ethylene terephthalate), polyamide, polyoxymethylene, polyetherimide, polyacrylate, copolymers thereof, polyester, vinyl ester, epoxy, or polyurethane.

[0062] In a preferred embodiment, the posts are made from fiberglass reinforced epoxy resin.

[0063] According to one embodiment, each post has a tubular portion.

[0064] According to one embodiment, the pillar is at least partially coated with a radiative thermal barrier coating surrounding the pillar.

[0065] According to one embodiment, the radiant thermal barrier coating extends at least from the inner end of the column perpendicular to the thickness of the wall to the radiant multi-layer thermal barrier cover.

[0066] According to one embodiment, the radiant thermal barrier coating is one of a type of material called single-layer insulation (SLI), which includes a sheet of polymeric material, such as polyimide or polyethylene, coated with a metal, such as aluminum (referred to using the abbreviation MLI and described above), and a pre-deposited layer including a binder and aluminum particles.

[0067] According to one embodiment, each post is provided with one or more through holes opening into the interior space of the post.

[0068] According to one embodiment, the interior space of each pillar is filled with an insulating packing of an open-cell porous material, such as, for example, open-cell polyurethane foam, glass wool, mineral wool, polyester stuffing, polymer aerogels, particularly polyurethane-based aerogels sold under the brand name Slentite®, and silica aerogels.

[0069] According to an alternative or complementary embodiment, each column has an interior space lined with a radiant multi-layer insulation cover made of multi-layer insulation (MLI).

[0070] According to one embodiment, the primary sealing membrane is made up of two layers of corrugated metal sheet stacked on top of each other with a spacer element inserted between the two layers.

[0071] According to one embodiment, the primary sealing membrane has an additional space interposed between the two layers of the primary sealing membrane.

[0072] According to one embodiment, the additional space is evacuated.

[0073] According to another embodiment, the additional space is connected to an inert device comprising an inert gas tank, preferably containing helium.

[0074] According to one embodiment, the secondary insulating barrier consists of insulating panels secured to the load-bearing structure.

[0075] According to one embodiment, each insulating panel is composed of a layer of insulating polymer foam sandwiched between inner and outer plates made of a polymer matrix reinforced with fibers, such as plywood or fiberglass.

[0076] According to one embodiment, the inner plate of the insulation panel is fitted with a metal plate for fastening the edges of the corrugated metal sheet of the secondary sealing membrane to the insulation panel.

[0077] According to one embodiment, the secondary sealing membrane comprises a first corrugation row having parallel first corrugations and a second corrugation row having parallel second corrugations.

[0078] According to one embodiment, the first and second corrugations of the secondary sealing membrane protrude outwardly towards the load-bearing structure, and the insulating panel of the secondary insulating barrier has an inner surface with two series of slots perpendicular to each other for receiving the first and second corrugations of the secondary sealing membrane, respectively.

[0079] According to another embodiment, the first and second corrugations of the secondary sealing membrane project inwardly from the load bearing structure.

[0080] According to one embodiment, the insulation panel of the secondary insulating barrier is provided with stress relief slots opening to an inner surface of the insulation panel, each stress relief slot being positioned opposite one of the first or second corrugations of the secondary sealing membrane.

[0081] According to another embodiment, the outer and inner containment barriers are free-standing barriers connected to each other by a spacer structure.

[0082] According to one embodiment, the invention relates to a sealed, insulated tank comprising a plurality of walls as described above.

[0083] In one embodiment, the liquefied gas is liquid hydrogen.

[0084] The tanks can be made using various technologies, in particular in the form of integral membrane tanks.

[0085] Such tanks may be part of onshore storage facilities or may be installed on coastal or deep sea floating structures, in particular liquid hydrogen carriers, Floating Storage and Regasification Units (FSRUs), Floating Production Storage and Offloading Units (FPSOs), etc. Such tanks may also be used as fuel tanks on ships of any type.

[0086] According to one embodiment, the ship used to transport liquefied gas comprises a double hull and the aforementioned tank located inside said double hull.

[0087] According to one embodiment, the invention also provides a liquefied gas transfer system comprising a ship as described above and an insulated pipe arranged to connect the tank installed in the hull of the ship to an onshore or floating storage facility.

[0088] According to one embodiment, the transfer system includes a pump that drives the flow of liquefied gas through insulated pipes between the onshore or floating storage facility and the vessel's tanks.

[0089] According to one embodiment, the invention also provides a method for loading or unloading such a ship, in which liquefied gas is transferred through insulated pipes from a land-based or floating storage facility to said tanks on board the ship, or from said tanks on board the ship to a land-based or floating storage facility.

[0090] The invention will be better understood and further objects, details, features and advantages thereof will be more clearly explained in the following detailed description of some specific embodiments of the invention, given by way of non-limiting examples only with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0091] [Figure 1] FIG. 1 is a schematic perspective cross-sectional view of a load-supporting structure for mounting a sealed, insulated storage tank for liquefied gas. [Diagram 2] FIG. 2 is a partial perspective view of a wall of a sealed, insulated tank according to the first embodiment. [Diagram 3] FIG. 3 is a perspective view showing the secondary insulating barrier of the wall of FIG. [Figure 4] FIG. 4 is a perspective view showing the secondary insulating barrier and secondary sealing membrane of the wall of FIG. [Diagram 5] FIG. 5 is a partial cross-sectional view of the secondary insulating barrier of the wall of FIG. 2, partially illustrating an anchoring arrangement for securing the load-bearing element of the primary insulating barrier to the secondary insulating barrier. [Figure 6] FIG. 6 is a cross-sectional view of the wall of FIG. 2 showing the secondary insulating barrier, the secondary sealing membrane, and the load-bearing elements of the primary insulating barrier. [Figure 7] FIG. 7 is a partial perspective view of the wall of FIG. 2 showing the secondary insulating barrier, the secondary sealing membrane, and the load-bearing elements of the primary insulating barrier. [Figure 8] FIG. 8 is a partial perspective view of the wall of FIG. 2 showing the secondary insulation barrier, the secondary sealing membrane, the load-bearing elements of the primary insulation barrier, and the radiant multi-layer insulation cover. [Figure 9] FIG. 9 is a partial perspective view similar to FIG. 8, also showing an inner plate for carrying the primary sealing membrane. [Figure 10] FIG. 10 is a cross-sectional view of a wall of a sealed, insulated tank according to a second embodiment. [Figure 11] FIG. 11 is a cross-sectional view of a wall of a sealed, insulated tank according to a third embodiment. [Figure 12] FIG. 12 is a partial cross-sectional view of the wall of FIG. 2 showing an insulating element disposed between the radiant multi-layer insulating cover and the secondary sealing membrane. [Figure 13] FIG. 13 is a partial cross-sectional view of a wall of a sealed, insulated tank according to another modified embodiment. [Figure 14] FIG. 14 is a schematic cross-sectional view of a tank on board a ship and a loading / unloading terminal for this tank. [Figure 15] FIG. 15 is a partial cross-sectional view of a wall of a sealed, insulated tank according to another modified embodiment. [Figure 16] FIG. 16 is a partial cross-sectional view of a wall of a sealed, insulated tank according to another modified embodiment. [Figure 17] FIG. 17 is a partial cross-sectional view of a wall of a sealed, insulated tank according to another modified embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0092] By convention, the terms "outside" and "inside" are used to determine the relative location of one element to another with respect to the interior and exterior of the tank.

[0093] The liquefied gas stored in the tanks is liquid hydrogen in particular, and has the characteristic of being stored at approximately -253°C under atmospheric pressure.

[0094] FIG. 1 shows a load-bearing structure 1 for fixing a closed, insulated storage tank for liquefied gas.

[0095] The load-bearing structure 1 may in particular be made of self-supporting metal plates, or more generally of any type of rigid partition with suitable mechanical properties. The load-bearing structure 1 is formed, for example, by the double hull of a ship. In FIG. 1, the load-bearing structure 1 has an overall polyhedral shape. It has two front and rear load-bearing walls 2, which in this case are octagonal, of which only the rear load-bearing wall 2 is shown. The front and rear walls 2 are, for example, cofferdam walls of the ship and run transversely to the longitudinal direction of the ship. The load-bearing structure 1 also has an upper load-bearing wall 3, a lower load-bearing wall 4 and lateral load-bearing walls 5, 6, 7, 8, 9, 10.

[0096] The wall 11 of the sealed, insulated tank according to the first embodiment will be described below with reference to Figures 2 to 9 and 12. The wall 11 has a multi-layer structure including, from the outside to the inside in the thickness direction of the wall 11, a secondary insulating barrier 12, a secondary sealing membrane 13, a primary insulating barrier 14, and a primary sealing membrane 15 intended to come into contact with the liquefied gas in the tank.

[0097] The secondary insulating barrier 12 is shown in figure 3. This barrier consists of a number of insulating panels 16 fixed to the load-bearing structure 1. Each insulating panel 16 has a layer of insulating polymer foam 17 sandwiched between an inner plate 18 and an outer plate 19. The inner plate 18 and the outer plate 19 are for example plywood plates bonded to a layer of insulating polymer foam 17. According to one variant, the inner plate 18 and the outer plate 19 are made of a polymer matrix reinforced with fibres, such as fibreglass. The insulating polymer foam may in particular be a polyurethane-based foam. The polymer foam is preferably reinforced using fibres, such as fibreglass, which helps to reduce thermal contraction.

[0098] The insulation panels 16 are fixed to the load-bearing structure 1 by secondary anchoring devices (not shown). Each insulation panel 16 is fixed, for example, at least at four corners. Each secondary anchoring device comprises a pin welded to the load-bearing structure 1 and a load-bearing element fixed to the pin and abutting a bearing area of ​​the insulation panel 16. According to one embodiment, an outer plate 19 of the insulation panel 16 protrudes beyond the insulating polymer foam layer 17 at least at the corners of the insulation panel 16 and forms a bearing area of ​​the insulation panel 16 cooperating with the bearing elements of the secondary anchoring devices. An elastic member, such as a Belleville washer, is threaded onto the pin between a nut attached to the pin and the bearing element, thereby ensuring that the insulation panel 16 is elastically fixed to the load-bearing structure 1.

[0099] Preferably, a mastic portion 20 is interposed between the outer plate 19 of the insulation panel 16 and the load-bearing structure 1. The mastic portion 20 serves to compensate for surface irregularities of the load-bearing structure 1. According to a preferred variant embodiment, the mastic portion 20 adheres to the outer plate 19 of the insulation panel 16 and to the load-bearing structure 1. The mastic portion 20 serves to fasten the insulation panel 16 to the load-bearing structure 1. In such a variant embodiment, a secondary fastening device is optional.

[0100] The insulation panels 16 are substantially cuboid in shape and are juxtaposed in parallel rows separated from one another by gaps 21 that provide assembly clearance. The gaps 21 are filled with a heat-resistant filler (not shown), for example glass wool, mineral wool or open-cell flexible polymer foam. The gaps can also be filled with insulation plugs, as described, for example, in WO 2019 / 155157 or WO 2021 / 028624.

[0101] In the illustrated embodiment, the inner surface of the insulation panel 16 has two mutually perpendicular rows of slots 22 adapted to receive corrugations 24 formed in the corrugated metal sheet 25 of the secondary sealing membrane 13 and projecting towards the outside of the tank. Each row of slots 22 is parallel to two opposite sides of the insulation panel 16. In the illustrated embodiment, the slots 22 extend through the entire thickness of the inner plate 10 and through the inner portion of the insulating polymer foam layer 17. Preferably, the slots 22 are shaped to match the corrugations 24 of the secondary sealing membrane 13.

[0102] Furthermore, a metal plate 26 is attached to the inner plate 18 of the insulation panel 16 for fixing the edges of the corrugated metal sheet 25 of the secondary sealing membrane 13 to the insulation panel 16. The metal plate 26 extends in two perpendicular directions, which are parallel to two opposite sides of the insulation panel 16, respectively. The metal plate 26 is fixed to the inner plate 18 of the insulation panel 16 using, for example, screws, rivets, or staples. The metal plate 26 is disposed in a recess formed in the inner plate 18, and the inner surface of the metal plate 26 is flush with the inner surface of the inner plate 18.

[0103] Furthermore, the insulation panel 16 is provided with stress relief slots 27 which reduce its stiffness, so that the secondary insulation barrier 12 is deformed as uniformly as possible. This ensures that the deformation of the corrugations 24 of the secondary sealing membrane 13 is as uniform as possible. Preferably, the insulation panel 16 is provided with stress relief slots 27 at least opposite each of the corrugations 24 of the secondary sealing membrane 13. Thus, as shown for example in FIG. 3, the stress relief slots 27 extend from the bottom of each slot 22 towards the outer plate 19 of the insulation panel 16. According to an optional variant, the insulation block 16 is also provided with stress relief slots which open onto the outer surface of the insulation panel 16. Such stress relief slots are not located opposite the corrugations 24 of the secondary sealing membrane 13, but in the middle between two parallel corrugations 24.

[0104] 4, the secondary sealing membrane 13 includes a plurality of corrugated metal sheets 25, each of which is substantially rectangular. The corrugated metal sheets 25 typically have a coefficient of expansion of, for example, 1.2×10 -6 ~2×10 -6 K -1 It is made of Invar®, an alloy of iron and nickel with a thermal expansion coefficient of typically 7×10 -6 K -1 The corrugated metal sheet 25 is preferably made of a high manganese content iron alloy, such as CrN 112. Alternatively, the corrugated metal sheet 25 may be made of stainless steel or aluminum.

[0105] The corrugated metal sheets 25 are lap welded along their edges to seal the secondary sealing membrane 13. Additionally, the corrugated metal sheets 25 are offset relative to the insulation panels 16 of the secondary insulation barrier 12 such that each corrugated metal sheet 25 extends together across adjacent insulation panels 16. To secure the secondary sealing membrane 13 to the secondary insulation barrier 12, the edges of the corrugated metal sheets 25 are welded to the metal plates 26, for example by spot welding.

[0106] The secondary sealing membrane 13 has corrugations 24, more specifically a first row of corrugations 24a extending parallel to a first direction and a second row of corrugations 24b extending parallel to a second direction. The directions of the rows of corrugations 24a, 24b are perpendicular to each other. Each of the rows of corrugations 24a, 24b is parallel to two opposite edges of the corrugated metal sheet 25. In this case, the corrugations 24 protrude towards the outside of the tank, i.e. towards the load-bearing structure 1. The secondary sealing membrane 13 has a number of flat areas 28 between the corrugations 24.

[0107] As shown in Figures 4 and 5, the corrugations 24 of the corrugated metal sheet 25 fit into slots 22 formed in the inner surface of the insulation panels 16 and into gaps 21 formed between adjacent insulation panels 16.

[0108] Furthermore, each of the flat areas 28 of the secondary sealing membrane 13 is traversed by a primary anchoring device 29, shown in detail in FIG. 5, intended to fasten a load-bearing element 30 of the primary insulation barrier 14 to an insulation panel 16 of the secondary insulation barrier 12. Each primary anchoring device 29 is provided with a pin 31 passing through the secondary sealing membrane 13. The outer end of the pin 31 is fixed to one of the insulation panels 16. To that end, in the illustrated embodiment, the outer end of each pin 31 is screwed into a threaded bushing 32 fixed in a hole in the inner plate 18 of one of the insulation panels 16. Furthermore, the pin 31 includes a flange 33 extending radially relative to the axis of the pin 31.

[0109] A flange 33 is seal welded to the secondary sealing membrane 13 around the orifice in the secondary sealing membrane 13 through which the pin 31 passes, maintaining the secondary sealing membrane 13 sealed.

[0110] 5, the outer plate 34 has an orifice through which the pin 31 passes. The primary anchoring device 29 includes a nut 35 that is threaded onto the threaded inner end of the pin 31, thereby holding the outer plate 34 against the flat area 28 facing the secondary sealing membrane 13. The outer plate 34 has two functions. First, it presses the secondary sealing membrane 13 against the insulating panel 16 of the secondary insulating barrier 12, preventing the secondary sealing membrane 13 from peeling off due to excessive pressure of the secondary insulating barrier 12 against the primary insulating barrier 14. Second, it secures the load-bearing element 30 of the primary insulating barrier 14, as will be described in more detail below.

[0111] Preferably, the outer plate 34 contacts the corresponding flat area 28 over 70% or more of the surface area of ​​the flat area 28, and more preferably over 90% to 100% of the surface area.

[0112] The outer plate 34 is made of a metal, such as stainless steel, but can also be made of a composite material, such as glass-filled epoxy.

[0113] As shown in Figure 7, the primary insulating barrier 14 comprises a number of load bearing elements 30 extending in the thickness direction of the wall 11. The load bearing elements 30 support the primary sealing membrane 15 and thus absorb the stresses caused by the hydrostatic and dynamic pressures exerted on the primary sealing membrane 15 by the liquefied gas contained in the tank. The load bearing elements 30 are aligned in a row parallel to the direction of the corrugations of the first corrugation row 24a and in a row parallel to the direction of the corrugations of the second corrugation row 24b.

[0114] Each load bearing element 30 has an outer base 36, an inner base 37, and a post 38 extending between the outer base 36 and the inner base 37. The outer base 36 and the inner base 37 each have a sleeve 39 into which one end of the post 38 is fitted, and a support flange 40 extending radially from one end of the sleeve 39. In an alternative embodiment, the sleeve 39 of the outer base 36 and the inner base 37 is fitted over the post 38.

[0115] The outer base 36 and the inner base 37 may be made of a metal, such as stainless steel, or a composite material, such as glass-filled epoxy resin. The outer base 36 and the inner base 37 may be fixed to the post 38 by any means, in particular by gluing.

[0116] According to another variant embodiment, the post 38, the outer base 36 and the inner base 37 are integral with one another, for example by moulding.

[0117] The pillars 38 are tubular and preferably have a circular cross section. According to an advantageous embodiment, the pillars 38 are made of a composite material including fibers and a matrix. Such pillars 38 provide sufficient compressive strength for a limited conductive section and limit the heat transfer from the outside to the inside of the tank through the pillars 38. The fibers may be, for example, glass fibers, carbon fibers, aramid fibers, flax fibers, basalt fibers, or mixtures thereof. The matrix may be, for example, polyethylene, polypropylene, poly(ethylene terephthalate), polyamide, polyoxymethylene, polyetherimide, polyacrylate, polyaryletherketone, polyetheretherketone, copolymers thereof, polyester, vinylester, epoxy, or polyurethane. In a particular embodiment, the pillars 38 are made of fiberglass reinforced epoxy resin.

[0118] Preferably, the pillars 38 are provided with through holes (not shown) that facilitate depressurization of their interior space when the primary insulating barrier 14 is depressurized, as described below. Moreover, the interior space of the pillars 38 is preferably filled with a gas-permeable insulating packing, in particular made of an open-cell porous material, for example open-cell polyurethane foam, glass wool, mineral wool, melamine foam, polyester wadding, polymer aerogels, in particular polyurethane-based aerogels sold under the brand name Slentite®, or open-cell insulating polymer foams, such as silica aerogels.

[0119] Alternatively or additionally, the interior space may be provided with a radiant multi-layer insulation cover made of multi-layer insulation (MLI) as described below, which is intended to reduce heat loss due to thermal radiation.

[0120] Each support flange 40 of the outer base 36 is fixed to one of the outer plates 34. As shown in FIG. 6, each support flange 40 of the outer base 36 is fixed to the outer plates 34, for example, by rivets 41 distributed around the axis of the load-bearing element 30.

[0121] 9, each support flange 40 of the inner base 37 is fixed against an inner plate 42, which is made of a metal, for example stainless steel. The support flanges 40 of the inner base 37 are fixed to the inner plate 42, for example by means of rivets 43 distributed around the axis of the load-bearing element 30.

[0122] Thus, the load-bearing elements 30 are not rigidly connected to each other, but each form an individual support structure supporting a flat area 46 of the primary sealing membrane 15, ensuring that stress distribution between the corrugations 45 of the primary sealing membrane 15 is met.

[0123] 2, the primary sealing membrane 15 is also obtained by assembling a plurality of corrugated metal sheets 44. Each of the corrugated metal sheets 44 is substantially rectangular. The corrugated metal sheets 44 have, for example, a coefficient of expansion of typically 1.2×10 -6 ~2×10 -6 K -1 It is made of Invar®, an alloy of iron and nickel with a thermal expansion coefficient of typically 7×10 -6 K -1 The corrugated metal sheet 44 is preferably made of a high manganese content iron alloy, such as CrN 112. Alternatively, the corrugated metal sheet 44 may be made of stainless steel or aluminum.

[0124] The corrugated metal sheet 44 is lap welded along its edges to seal the primary sealing membrane 15. The primary sealing membrane 15 has corrugations 45. More specifically, said sealing membrane has a first row of corrugations 45a extending parallel to a first direction and a second row of corrugations 45b extending parallel to a second direction. The direction of the rows of corrugations 45a, 45b is vertical and parallel or perpendicular to the rows of the load-bearing elements 30. Each of the rows of corrugations 45a, 45b is parallel to two opposite edges of the corrugated metal sheet 44. The corrugations 45 protrude towards the inside of the tank, i.e. away from the load-bearing structure 1. Each of the corrugated metal sheets 44 has a number of flat areas 46 between the corrugations 45.

[0125] The pitch of the corrugations 24 of the secondary sealing membrane 13 is equal to or an integer multiple of the pitch of the corrugations 45 of the primary sealing membrane 15. Furthermore, the corrugations 24 of the secondary sealing membrane 13 are disposed opposite the corrugations 45 of the primary sealing membrane 15 in the thickness direction of the wall 11. Thus, the flat regions 46 of the primary sealing membrane 15 are disposed opposite the flat regions 28 of the secondary sealing membrane 13 in the thickness direction of the wall 11. Thus, the axis of each load-bearing element 30 passes through both the center of the flat region 46 of the primary sealing membrane 15 and the center of the flat region 28 of the secondary sealing membrane 13.

[0126] Preferably, each inner plate 42 contacts a corresponding flat area 46 of the primary sealing membrane 15 over 70% or more of the surface area of ​​the flat area 46, and more preferably over 90%-100% of the surface area.

[0127] The corrugated metal sheet 44 of the primary sealing membrane 15 is fixed at least along its edges to the inner plate 42 by welding. For this purpose, the edges of the corrugated metal sheet 44 are welded to the inner plate 42, for example by spot welding. According to an advantageous embodiment, the corrugated metal sheet 44 is also fixed to the inner plate 42 outside the edge zone. For this purpose, the corrugated metal sheet 44 can in particular be welded to the inner plate 42 by stake welding. According to an advantageous embodiment, the corrugated metal sheet 44 is welded to each of the inner plates 42 which support it. Such an embodiment is particularly advantageous in that it allows a more uniform distribution of stresses between the corrugations 45 of the primary sealing membrane 15.

[0128] Furthermore, the primary insulating barrier 14 has a gas phase that is under negative pressure, i.e. has an absolute pressure lower than atmospheric pressure, to provide the primary insulating barrier 14 with the necessary insulating properties. Preferably, the gas phase in the primary insulating barrier 14 has an absolute pressure of less than 1 Pa, more preferably less than 10 -1 Pa, and even more preferably less than 10 -2 Less than Pa, e.g. 10 -3 An absolute pressure of the order of Pa is applied to the primary insulating barrier 14. For this purpose, the primary insulating barrier 14 is preferably connected to a vacuum pump. According to an advantageous embodiment, a cryopump is used as an alternative or complement to the aforementioned vacuum pump in order to achieve the target reduced pressure in the primary insulating barrier 14. Also, before the reduction in pressure, the primary insulating barrier 14 is filled with an inert gas having an anti-sublimation temperature higher than the liquefaction temperature of the liquefied gas stored in the tank. For example, if the liquefied gas stored in the tank is liquid hydrogen, the inert gas may be carbon dioxide. Thus, taking into account the temperature of hydrogen in the liquid state, the carbon dioxide contained in the primary insulating barrier 14 will undergo anti-sublimation in the primary insulating barrier 14 and will help to reduce the pressure therein.

[0129] The primary insulating barrier 14 is not only reduced in pressure, but also includes an insulating material that further enhances its insulating properties. Furthermore, as shown in FIG. 8, the primary insulating barrier 14 includes a radiant multi-layer insulating cover 47 that helps to reduce heat transfer by thermal radiation. The radiant multi-layer insulating cover 47 is usually made of multi-layer insulation (MLI). The radiant multi-layer insulating cover 47 thus includes a stack of sheets made of a metal, such as aluminum or silver, or a metal-coated polymeric material, which are separated from each other by woven or non-woven fabric layers made of polymeric fibers, such as polyester fibers or glass fibers. The sheets made of polymeric materials are made, for example, of polyimide, particularly sold under the brand name Kapton®, or polyethylene terephthalate, particularly sold under the brand name Mylar®. These thin sheets are coated on both sides with a metal, such as aluminum or silver.

[0130] As shown in Figure 8, the radiant multi-layer insulation cover 47 has openings through which the columns 38 of the load bearing element 30 pass. Preferably, the radiant multi-layer insulation cover 47 is placed in the coldest part of the primary insulation barrier 14. In other words, the radiant multi-layer insulation cover 47 is placed in a plane parallel to the secondary sealing membrane 13 and the primary sealing membrane 15, but closer to the primary sealing membrane 15 than to the secondary sealing membrane 13. This places the radiant multi-layer insulation cover 47 in the coldest area of ​​the primary insulation barrier 14, decreasing the emissivity of each layer and thus increasing the efficiency of the radiant multi-layer insulation cover 47.

[0131] In this case, the radiant multi-layer insulation covering 47 is secured to the posts 38 of the load-bearing element 30, for example by gluing or by a pair of hook-and-loop fastening strips, where one strip is associated with the radiant multi-layer insulation covering 47, for example by sewing or gluing, and the other strip is glued to one of the posts 38.

[0132] As shown in FIG. 12, the primary insulation barrier 14 further comprises an insulation element 51 having an open cell porous structure, the insulation element 51 being disposed between the radiant multi-layer insulation cover 47 and the secondary sealing membrane 13.

[0133] Such an insulating element 51 has several functions. Firstly, it further reduces the temperature of the area of ​​the primary insulating barrier 14 where the radiant multi-layer insulating cover 47 is located, further increasing its efficiency. Secondly, it also helps to limit the degradation of the insulating performance when the pressure in the primary insulating barrier 14 is higher than the specified pressure value for the use of the radiant multi-layer insulating cover 47 alone. Indeed, the aforementioned radiant multi-layer insulating cover 47 is typically used for a period of 10 -3 At low pressures below 10 Pa, the insulation performance is excellent, but decreases when the pressure exceeds the aforementioned threshold. Such pressure conditions are especially likely to occur if the primary sealing membrane 15 or the secondary sealing membrane 13 loses its seal, which causes a decrease in the negative pressure in the primary insulating barrier 14, or when the tank is being cooled and the inert gas contained in the primary insulating barrier 14 has not yet completely desublimated, or when the tank is low-filled, for example during a return voyage of a ship with only a small amount of liquefied gas in the tank. The insulation element 51 also reduces the activation capacity of convection in the primary insulating barrier 14. Thirdly, the insulation element 51 constitutes a surface for receiving solids resulting from the desublimation of the inert gas or gases contained in the primary insulating barrier 14, thereby limiting the mechanical stresses that may be exerted on the other elements of the wall 11, in particular the load-bearing element 30, the radiant multilayer insulation cover 47, and the secondary and primary sealing membranes 13 and 15.

[0134] The insulating element 51 may be made of, for example, glass wool, mineral wool, polyester wadding, open cell polymer foam (such as open cell polyurethane foam), or melamine foam. Preferably, the insulating element 51 is made of glass wool. Preferably, the insulating element 51 is packed in the form of a panel that provides structural strength for easy handling.

[0135] 12, the insulating element 51 fills the entire space between the radiant multi-layer insulation covering 47 and the secondary sealing membrane 13. The secondary insulating barrier also includes one or more retaining members to limit displacement of the insulating element 51 toward the primary sealing membrane 15, thereby preventing the insulating element from compressing the radiant multi-layer insulation covering 47 and reducing its performance.

[0136] In this case, the retaining member is a textile retaining layer 52 made of polymeric fibres, for example polyester fibres, or glass fibres. The textile retaining layer 52 is fixed to the load-bearing element 30. This textile retaining layer 52 can be fixed to the load-bearing element 30 by any means, in particular by gluing. In FIG. 12, the textile retaining layer 52 is fixed to the load-bearing element 30 by means of a flange 53 which is first fixed to the load-bearing element 30 and then to the textile retaining layer 52.

[0137] In such an embodiment, the radiant multi-layer insulation covering 47 may be secured to the textile retention layer 52 by evenly distributed bond areas, stitches, or staples. This eliminates the need to secure the radiant multi-layer insulation covering 47 directly to the load bearing element 30, reducing thermal bridging due to conduction. This ensures correct placement of the radiant multi-layer insulation covering 47, limits creases therein, and ensures retention of the radiant multi-layer insulation covering 47, especially in the event of uneven pressure levels within the primary insulation barrier 14 or excessive pressure between the radiant multi-layer insulation covering 47 and the secondary sealing membrane 13.

[0138] According to a variant embodiment shown in FIG. 13, the retaining member is formed by a flange 54 fixed to the load-bearing element 30 and against which the inner surface of the insulating element 51 abuts.

[0139] In the variant embodiment of figure 13, the thickness of the insulating element 51 is smaller than the distance between the secondary sealing membrane 13 and the radiant multi-layer insulating cover 47 in the thickness direction of the wall 11. In other words, there is an empty space between the insulating element 51 and the radiant multi-layer insulating cover 47. This reduces the amount of insulating element 51 used, which helps to reduce the cost of the tank without too drastically reducing the insulating performance of the primary insulating barrier 14, especially when the pressure in the primary insulating barrier 14 is higher than the specified pressure value.

[0140] Figure 10 shows the wall of a sealed, insulated tank according to a second embodiment, without showing the insulating element 51. This embodiment differs from the embodiments described above with reference to figures 2 to 9 and 12 in that the corrugations 24 of the secondary sealing membrane 13 do not project outwards, i.e. towards the load-bearing structure 1, but inwards, i.e. away from the load-bearing structure 1.

[0141] Figure 11 shows the wall of a sealed insulated tank according to a third embodiment, without showing the insulating element 51. This embodiment differs from the above described embodiment with reference to figures 2 to 9 and 12 in that the primary sealing membrane 15 comprises two layers 48, 49 of corrugated metal sheets 44 stacked on top of each other, which provides a redundancy of the sealing function and improves the reliability of the primary sealing membrane 15.

[0142] Each of the two layers 48, 49 of the corrugated metal sheet 44 has a structure similar to that of the primary sealing membrane 15 described above with reference to Figure 2. The corrugations 45 of the two layers 48, 49 are arranged with the same pitch and are located opposite each other in the thickness direction of the wall 11.

[0143] Furthermore, spacer elements (not shown) of a certain thickness are interposed between the two layers 48, 49, so that the distance between them is kept substantially constant. Such spacer elements are, for example, arranged in the flat area 46 of the corrugated metal sheet 44. Each spacer element is fixed to the inner plate 42, for example by an anchoring device (not shown) passing through the layer 48. Furthermore, the edges of the corrugated metal sheet 44 of the layer 49 are fixed, for example by welding, to anchor plates (not shown) which are either fixed to the spacer elements or formed by them. According to an embodiment, the spacer elements are made of a thermally conductive material, such as metal, in particular stainless steel. This limits the temperature difference between the two layers 48, 49 of the primary sealing membrane 15 and therefore the influence of this double layer on the movement of the cryopump in the primary insulating barrier 14.

[0144] According to one embodiment, the gas phase in the additional space 50 interposed between the two layers 48, 49 of the primary sealing membrane 15 is decompressed, i.e. brought to a pressure lower than atmospheric pressure. The gas phase in the additional space 50 is preferably at a pressure of 10 -1 Pa or less, more preferably 10 -2 Less than Pa, e.g. 10 -3 The additional space 50 is brought to an absolute pressure of about Pa. For this purpose, the additional space 50 is connected to a vacuum pump.

[0145] According to another embodiment, the additional space 50 is flushed with an inert gas, for example helium, which has a lower liquefaction temperature than hydrogen, thus preventing the inert gas from condensing in the additional space 50. For this purpose, the installation includes an inert gas tank associated with an inert circuit, which is connected to the additional space 50 and further to a gas analyzer configured to detect the presence of a gas stored in the tank, for example hydrogen, in the inert gas flowing through the additional space 50. The flushing with inert gas thus allows leaks in the layer 49 of the primary sealing membrane 15 to be detected.

[0146] According to another embodiment, not shown, the sealed insulating tank is not a membrane tank but a tank in which liquefied gas is stored under pressure. Such tanks are self-supporting. In the case of tanks carried on board ships, the tanks therefore do not use the double hull of the ship as a load-bearing structure, as in the previously mentioned membrane tanks. In the context of such ships, these tanks are called tanks of type C. In the onshore context, these tanks are called "pressure vessels" according to the definition of the CODAP Pressure Vessels Code. The tank consists of two self-supporting sealing barriers, for example of cylindrical shape, arranged one inside the other. The two sealing barriers are fixed to each other and kept at a certain distance from each other by a spacing structure. The insulating barrier formed between the two barriers exhibits similar characteristics to the previously mentioned primary insulating barrier 14. In particular, the insulating barrier is depressurized and comprises a radiating multi-layer insulating cover 47 and an insulating element 51 arranged between the radiating multi-layer insulating cover 47 and the outer sealing barrier. The relative arrangement of the radiant multi-layer insulating cover 47 and the insulating element 51 is the same as that described above in connection with Figures 12 and 13, i.e. from the outside to the inside of the tank, the wall consists of an outer sealing barrier, an insulating element 51, the radiant multi-layer insulating cover 47 and an outer sealing barrier intended to be in contact with the liquefied gas stored in the tank.

[0147] In a tank of the above mentioned type, the radiant multi-layer insulation cover 47 is in particular fixed to the inner sealing barrier, for example by gluing. Alternatively, the radiant multi-layer insulation cover 47 may be fixed to the insulation element 51 by any suitable means, in particular by gluing, stitching, staples, etc. The insulation element 51 is fixed to the outer sealing barrier by any suitable means, in particular by gluing or mechanical fastening devices.

[0148] Furthermore, in variants in which the radiant multi-layer insulation cover 47 is not fixed to the insulation element 51 and there is an empty space between the radiant multi-layer insulation cover 47 and the insulation element 51 in the wall thickness direction, an additional layer may be fixed to the inner surface of the insulation element 51. This additional layer may consist of a woven or non-woven fabric, a metal film or a film made of a polymeric material coated with a metal. Said additional layer may thus contribute to one or both of two functions: to increase the loss of pressure head of the gas flow in order to reduce convective movements, especially under degraded vacuum conditions, and to reduce the emissivity of the inner surface of the insulation element 51.

[0149] Figure 15 shows another possible alternative embodiment, which differs from the embodiment described above with reference to figure 10 in that it comprises a plurality of radiant multi-layer insulation covers 47, 55. In the illustrated variant embodiment, the primary insulation barrier 14 comprises two radiant multi-layer insulation covers 47, 55 spaced apart from each other in the wall thickness direction. According to an example embodiment, the two radiant multi-layer insulation covers 47, 55 are spaced apart from each other in the wall thickness direction by a distance of 30 mm to 160 mm. The presence of a plurality of radiant multi-layer insulation covers 47, 55 further reduces the heat transfer by thermal radiation.

[0150] In this embodiment, each radiant multi-layer insulation cover 47, 55 includes multiple sections that are fastened together by fastening means 56, such as hook-and-loop fastening strips. Furthermore, preferably the fastening strips of the two radiant multi-layer insulation covers 47, 55 are offset from each other, i.e., not located between the same two rows of load-bearing elements 30, to limit thermal bridging.

[0151] Figure 16 shows another embodiment. Like the embodiment of Figure 15, the primary insulation barrier 14 comprises two radiant multi-layer insulation covers 47, 55 spaced apart from each other in the wall thickness direction. However, the primary insulation barrier 14 further comprises an insulation element 57 of open cell porous structure arranged between the endmost radiant multi-layer insulation cover 55 and the secondary sealing membrane 13. Such insulation element 57 has the same function as the insulation element 51 described above with reference to Figures 12 and 13.

[0152] The insulating element 57 may be made of, for example, glass wool, mineral wool, polyester wadding, open cell polymer foam (such as open cell polyurethane foam), or melamine foam. Preferably, the insulating element 57 is made of glass wool. Preferably, the insulating element 57 is packed in the form of a panel that provides structural strength for easy handling.

[0153] Figure 17 shows another embodiment, which differs from the embodiment described above with reference to Figure 10 in that each pillar 38 of the load-bearing element 30 is at least partially coated with a radiant thermal barrier coating 58 surrounding the pillar 38. Such a radiant thermal barrier coating 58 limits the absorption by the pillar of radiation reflected from the radiant multi-layer insulation cover 47.

[0154] The radiant thermal barrier coating 58 extends from at least the inner end of the column 38 to the radiant multi-layer insulation cover 47. Preferably, the radiant thermal barrier coating 58 extends to the outer end of the column 38. The radiant thermal barrier coating 58 may be glued to the column or may be directly attached to the column. Alternatively, the radiant thermal barrier coating may be secured between the inner base 37 and the outer base 36. In an embodiment not shown, the radiant thermal barrier coating 58 abuts and / or is secured to the fabric retaining layer 52 as shown in FIG. 12 or is secured to the flange 54 as shown in FIG. 13. The radiant thermal barrier coating 58 is one of the materials referred to as single layer insulation (SLI), which includes a sheet of polymeric material, such as polyimide or polyethylene, coated with a metal, such as aluminum, and materials referred to using the abbreviation MLI as explained above, and a layer including a binder and aluminum particles, pre-deposited on the column 37.

[0155] 14, a cross-sectional view of a ship 70 shows a sealed, insulated tank 71 of generally prismatic shape mounted within the ship's double hull 72. The wall of the tank 71 comprises a primary sealing membrane intended to be in contact with the liquefied gas in the tank, preferably liquid hydrogen, a secondary sealing membrane arranged between the primary sealing membrane and the ship's double hull 72, and two insulating barriers arranged between the primary sealing membrane and the secondary sealing membrane and between the secondary sealing membrane and the double hull 72.

[0156] As is known, a loading / unloading pipe 73 located on the upper deck of the ship can be connected to an offshore or port terminal using suitable connectors to transfer cargoes of liquefied gas to and from the tanks 71.

[0157] FIG. 14 also shows an example of a marine terminal including a loading / unloading point 75, an undersea line 76, and an onshore facility 77. The loading / unloading point 75 is a static offshore installation consisting of a movable arm 74 and a pole 78 that holds the movable arm 74. The movable arm 74 supports a bundle of insulated hoses 79 that can be connected to a loading / unloading pipe 73. The orientable movable arm 74 can be adapted to any size of hydrogen carrier. A connecting line (not shown) runs inside the pole 78. The loading / unloading point 75 allows loading and unloading of the hydrogen carrier 70 to the onshore facility 77. The installation has a liquefied gas storage tank 80 and a connecting line 81 connected to the loading / unloading point 75 via the undersea line 76. The undersea line 76 allows the liquefied gas to be transferred over long distances, e.g. 5 km, between the loading / unloading point 75 and the onshore facility 77, enabling the hydrogen carrier 70 to be kept far from shore during loading / unloading operations.

[0158] To generate the pressure required to transfer the liquefied gas, pumps on board the ship 70 and / or pumps installed at the onshore facility 77 and / or pumps installed at the loading / unloading points 75 can be used, or pressure build-up in the internal space of the tank caused by evaporation of the liquefied gas stored in the tank can be allowed to occur.

[0159] Although the present invention has been described with reference to some specific embodiments, it is obviously not limited thereto, but includes all technical equivalents of the described means and combinations thereof, provided they fall within the scope of the invention.

[0160] The use of the verbs "comprise", "comprendre" or "inclure", including where conjugated, does not exclude the presence of other elements or steps in addition to those stated in a claim.

[0161] In the claims, any reference signs placed between parentheses shall not be construed as construing as limiting the claim.

[0162] It will be more generally apparent to those skilled in the art that various modifications can be made to the above embodiments in light of the above disclosure. In the following claims, the terms used should not be construed to limit the claims to the embodiments described in this description, but rather to be intended to cover the language of the claims and include all equivalents within the scope of the common knowledge of those skilled in the art.

Claims

1. A wall of a sealed, insulated tank for storing liquefied gas, The wall (11) comprises an outer sealing barrier (13), an insulating barrier (14), and an inner sealing barrier (15), which are continuous in the thickness direction from the outside to the inside of the tank. The aforementioned insulating barrier (14) has a gas phase with an absolute pressure of less than 1 Pa. - A radiant multilayer thermal insulation cover (47) extending perpendicular to the thickness direction, comprising a laminate of multiple sheets separated from each other by a fiber layer, made of metal or a metal-coated polymer material, - Displaced between the radiant multilayer insulation cover (47) and the outer sealed barrier (13), an insulation element (51) having an open-cell porous structure, A wall (11) characterized by having the following features.

2. The inner sealing barrier (15) is configured to come into contact with the liquefied gas contained in the tank. The wall (11) according to feature 1.

3. The aforementioned thermal insulation element (51) is selected from glass wool, rock wool, polyester filler, and open-cell polymer foam. The wall (11) according to feature 1.

4. The radiant multilayer insulation cover (47) is positioned in a plane closer to the inner sealing barrier (15) than to the outer sealing barrier (13). The wall (11) according to claim 1 or 3.

5. The fiber layer of the radiant multilayer insulation cover (47) is manufactured using fibers selected from polymer fibers and glass fibers. The wall (11) according to claim 1 or 3.

6. The sheet, made from a metal or a metal-coated polymer material, is made from a material selected from aluminum, silver, an aluminum-coated polymer material, and a silver-coated polymer material. The wall (11) according to claim 1 or 3.

7. The gas phase of the insulating barrier (14) contains 50% by volume of an inert gas having a back sublimation temperature higher than the liquefaction temperature of the liquefied gas intended to be stored in the tank when the insulating barrier is packed at room temperature. The wall (11) according to claim 1 or 3.

8. The wall (11) according to claim 7, characterized in that the inert gas is carbon dioxide.

9. The heat insulating barrier (14) includes a load-supporting element (30) extending in the thickness direction between the outer sealing barrier (13) and the inner sealing barrier (15), The radiant multilayer insulation cover (47) is provided with an opening through which the load-supporting element passes. The wall (11) according to claim 1 or 3.

10. Each of the load-supporting elements (30) comprises an outer base (36), an inner base (37), and a column (38). Each of the outer base (36) and the inner base (37) is, A sleeve (39) into which one end of the column (38) is fitted, A support flange (40) extending radially from one end of the sleeve (39), has The wall (11) according to characteristic 9.

11. The column (38) is at least partially coated with a radiant heat insulating coating (58) surrounding the column (38). The wall (11) according to characteristic 10.

12. The thermal insulation barrier (14) further comprises at least one retaining member (52, 54) fixed to the load-supporting element (30) to restrict the movement of the thermal insulation element (51) toward the inner sealing barrier (15). The wall (11) according to characteristic 9.

13. The at least one retaining member is fixed to the load-supporting element (30) and includes a fiber-retaining layer (52) positioned between the heat-insulating element (51) and the radiant multilayer heat-insulating cover (47). The wall (11) according to characteristic 12.

14. The radiant multilayer insulation cover (47) is fixed to the fiber holding layer (52). The wall (11) according to feature 13.

15. The fiber-retaining layer (52) is manufactured using fibers selected from polymer fibers and glass fibers. The wall (11) according to feature 13.

16. The aforementioned heat insulating barrier (14) comprises several retaining members, Each of the holding members is formed from a flange (54) fixed to one of the load-supporting elements (30), and is in contact with the inner surface of one of the heat-insulating elements (51). The wall (11) according to characteristic 12.

17. The thermal insulation barrier (14) comprises several radiating multilayer thermal insulation covers (47, 55) each perpendicular to the thickness direction, Each of the aforementioned radiant multilayer thermal insulation covers (47, 55) comprises a laminate of multiple sheets made of metal or a metal-coated polymer material, separated from each other by a fiber layer. The wall (11) according to claim 1 or 3.

18. The aforementioned thermal insulation barrier (14) includes two radiant multilayer thermal insulation covers (47, 55), The two radiant multilayer insulation covers (47, 55) are preferably spaced apart by a distance of 30 to 160 mm. The wall (11) according to feature 17.

19. The inner sealing barrier is a primary sealing membrane (15) intended to come into contact with the liquefied gas contained in the tank. The aforementioned adiabatic barrier is a primary adiabatic barrier (14), The aforementioned outer sealing barrier is a secondary sealing membrane (13), The wall (11) further includes a secondary heat insulating barrier (12) supported by the load-bearing structure (1) and supporting the secondary sealing membrane (13). The wall (11) according to claim 1 or 3.

20. The aforementioned primary sealing membrane (15) is A first corrugation row (45a) having first corrugations parallel to each other, A second corrugation row (45b) having second corrugations that are parallel to each other and perpendicular to the first corrugations, Equipped with, The primary sealing membrane (15) comprises a plurality of flat regions (46) defined between two adjacent first corrugations and between two adjacent second corrugations, The primary insulating barrier (14) comprises at least one row of load-bearing elements, which include at least first, second, and third load-bearing elements (30) fixed to the secondary insulating barrier (12) and extending in the thickness direction, arranged continuously in a direction parallel to the first corrugation. The first, second, and third load-supporting elements (30) are fixed to the first, second, and third inner plates (42), respectively. The plurality of flat regions (46) include the first, second, and third flat regions, which are welded to the first, second, and third inner plates (42), respectively, in a continuous direction parallel to the first corrugation. The wall (11) according to characteristic 19.

21. The outer sealing barrier and the inner sealing barrier are self-supporting barriers connected to each other by a spacer structure. The wall (11) according to claim 1 or 3.

22. A sealed, insulated tank comprising a plurality of walls (11) as described in claim 1 or 3.

23. A ship (70) used for transporting liquefied gas, Double hull (72) and, The tank (71) according to claim 22, which is located inside the double hull, A ship equipped with these features.

24. The ship (70) described in claim 23, Insulated pipes (73, 79, 76, 81) are arranged to connect the tank (71) installed in the hull of the ship to a land-based or floating storage facility (77), A liquefied gas transfer system equipped with [a specific feature].

25. A method for loading or unloading a ship (70) according to claim 23, A method of sending liquefied gas from an onshore or floating storage facility (77) to the tank (71) on the ship (70) through insulated pipes (73, 79, 76, 81), or sending it from the tank (71) on the ship (70) to the onshore or floating storage facility (77).

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