Sealed, insulated tanks for storing and / or transporting liquefied gases

Abstract

The present invention relates to a sealed, insulated tank (1) for storing and / or transporting a liquefied gas, characterized in that the tank comprises, successively from the inside to the outside, a sealed and self-supporting internal reservoir (2) having an inner surface intended to be in contact with the liquefied gas and an outer surface, an insulating barrier (5) covering the outer surface of the internal reservoir and attached to the internal reservoir, and an outer sealing membrane (6) covering the outer surface of the insulating barrier and comprising a piece of sheet metal with bellows or corrugations (8) and attached to the insulating barrier or to the internal reservoir, wherein an intermediate space located between the internal reservoir and the outer sealing membrane contains a gas phase under reduced pressure in order to press the outer sealing membrane against the outer surface of the insulating barrier.

Description

[Technical field]

[0001] The present invention relates to the field of sealed, insulated tanks, in particular for the cryogenic storage and / or transport of liquefied gases, such as tanks for transporting liquid hydrogen, which has a temperature of about -253°C at atmospheric pressure, but which can also be stored at elevated pressure. These tanks can be installed at a fixed location or on land or floating vehicles. [Background technology]

[0002] According to the Boiler & Pressure Vessel Code (BPVC) of the American Society of Mechanical Engineers (ASME), fixed liquefied hydrogen storage tanks are known in the prior art, which consist of two sealed, rigid, self-supporting shells, one nested inside the other. The two shells are very thick, which makes the material costs and manufacturing difficulties very high to produce large capacity tanks using this technology. In particular, such tanks require significant manpower for their manufacture, while the need to perform quality control, especially on the welds, significantly increases the manufacturing costs of the tanks.

[0003] U.S. Patent No. 4,050,609 discloses a spherical liquefied gas storage tank, which is a sealed, self-supporting internal reservoir having an inner surface and an outer surface intended to be in contact with a liquefied gas; an insulating barrier covering an exterior surface of the internal reservoir, the insulating barrier being attached to the internal reservoir; an outer sealing membrane covering an outer surface of the thermal insulation barrier and attached to the thermal insulation barrier; A liquefied gas reservoir is disclosed that includes:

[0004] In US Patent No. 4,050,609, an aluminum sheet glued to the plywood plate of the insulation block and a fiberglass fabric connection are used as the outer sealing membrane. However, this outer sealing membrane is fragile and prone to tearing at the fiberglass fabric connection covering the studs. Therefore, it is not conceivable to place the insulation barrier under a vacuum. Summary of the Invention

[0005] The idea behind the present invention is to provide a sealed, insulated tank with a double sealing barrier for containing liquefied gases, which is adapted to provide high insulating performance for the storage of very cold products, for example liquid hydrogen at ambient pressure. Another idea behind the present invention is to provide a sealed, insulated tank that can be produced at competitive costs, even in very large volumes.

[0006] To this end, according to one embodiment, the invention provides a sealed insulated tank for storing and / or transporting liquefied gas, characterized in that the tank comprises, successively from the inside to the outside, a sealed and self-supporting internal reservoir having an inner surface intended to be in contact with the liquefied gas and an outer surface, an insulating barrier covering the outer surface of the internal reservoir and attached to the internal reservoir, and an outer sealing membrane covering the outer surface of the insulating barrier and comprising a piece of sheet metal with bellows or corrugations to allow elastic deformation and attached to the insulating barrier or to the internal reservoir, wherein an intermediate space located between the internal reservoir and the outer sealing membrane contains a gas phase under reduced pressure in order to press the outer sealing membrane against the outer surface of the insulating barrier.

[0007] These features make it possible to create a more or less high vacuum in the insulating barrier in order to increase its insulating performance. Moreover, the outer sealing membrane is made of bellows or corrugations, which allows it to absorb dimensional changes due to elastic deformation without breaking. These dimensional variations can be caused in particular by thermal contraction when the tank is cooled when filled with cold liquid, and by the intermediate space containing the insulating barrier being placed under vacuum, i.e. by compressive forces generated by the difference between atmospheric pressure and the pressure prevailing inside the intermediate space.

[0008] Moreover, since the outer membrane covers the surface of the insulating barrier, its dimensions are not determined by the resistance to the cargo pressure, nor by the atmospheric pressure, nor by the reduction in the gas phase in the intermediate space. In other words, a very thin membrane can be used. Furthermore, such a tank allows the pressure experienced by the internal reservoir to be reduced. In fact, the pressure experienced by the internal reservoir is reduced by, for example, 100 kPa compared to the situation that would exist if the atmospheric pressure was not transmitted to the outer surface of the internal reservoir.

[0009] According to a particular embodiment, the sealed, insulated tank has one or more of the characteristics described below, taken alone or in any technically possible combination.

[0010] The invention will be better understood and other objects, details, features and advantages will become more apparent from the following description of a number of specific embodiments of the invention, given by way of non-limiting example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a sealed insulated tank according to the first embodiment. [Diagram 2] FIG. 2 is a view similar to FIG. 1, showing a sealed, insulated tank according to a second embodiment. [Diagram 3]FIG. 3 is a perspective view of a corrugated metal plate that can be used as an outer sealing membrane. [Figure 4] FIG. 4 is a schematic cross-sectional view showing an insulating block that can be used to create an insulating barrier. [Diagram 5] FIG. 5 is a perspective view of another embodiment with a portion of the tank wall removed. [Figure 6] FIG. 6 is a view similar to FIG. 1 showing a sealed, insulated tank with supporting legs. [Figure 7] FIG. 7 is a view similar to FIG. 1 showing a closed, insulated tank with a hanger. [Figure 8] FIG. 8 is a perspective view of another embodiment with a portion of the tank wall removed. [Figure 9] FIG. 9 is a view similar to FIG. 1 showing a sealed insulated tank with a grid of internal reinforcements. [Figure 10] FIG. 10 is a schematic cross-sectional view showing a sealed heat-insulating tank according to another embodiment. [Figure 11] FIG. 11 is a schematic perspective view of a carrier having a sealed insulated tank as a fuel reservoir. [Figure 12] FIG. 12 is a cross-sectional view of the tank wall with the support legs attached. [Figure 13] FIG. 13 illustrates a mechanical coupler that can be used in a tank wall according to one embodiment. [Figure 14] FIG. 14 shows a cross-sectional view of the thermal barrier held by the mechanical coupler of FIG. 13 according to a first embodiment. [Figure 15] FIG. 15 is a view similar to FIG. 14 according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Several embodiments of a sealed, insulated tank for the storage and / or transport of liquefied gas will now be described, in which like reference numbers indicate similar or identical elements.

[0013] The sealed insulated tank may have various shapes, for example a prismatic shape with flat faces, as in most of the following figures, or a spherical shape, or a cylindrical shape whose directrix is ​​circular or polygonal. In the case of a cylindrical tank, the axial ends of the tank may be closed by flat or hemispherical walls. The sealed insulated tank may have a bilobal shape or another shape.

[0014] For example, as shown in Figs. 1 and 2, the tank 1 is successively divided into the following parts from the inside to the outside: a sealed and self-supporting internal reservoir 2 having an internal surface 3 intended to be in contact with the liquefied gas, and an external surface 4; a thermal insulating barrier 5 covering the outer surface 4 of the internal reservoir 2 and attached to the internal reservoir 2; an outer sealing membrane 6 covering the outer surface 7 of said thermal insulation barrier 5; Equipped with.

[0015] The outer sealing membrane 6 comprises a piece of sheet metal with bellows or corrugations 8 to allow elastic deformation. The outer sealing membrane 6 is attached to said insulating barrier 5.

[0016] The intermediate space located between the internal reservoir 2 and the outer sealing membrane 6 contains a gas phase under reduced pressure in addition to the insulating barrier 5 to press the outer sealing membrane 6 against the outer surface 7 of the insulating barrier 5.

[0017] The internal reservoir 2 is self-supporting and defines an internal space 9 which directly contains a cargo of liquefied gas. For this purpose, a similar technology may be used as for type C tanks, type C being understood within the meaning of the IGC Code of the International Maritime Organization. However, unlike type C tanks, the internal reservoir 2 has a single wall in the thickness direction instead of a double wall.

[0018] The internal reservoir 2 can be designed with widely different volumes depending on the requirements of the intended application, for example, about 10 3 m 3 ~10 5 m 3 , or even more.

[0019] According to one embodiment, the internal reservoir may comprise a metal shell having a thickness of more than 10 mm, or even more than 20 mm. Preferably, this thickness is less than 50 mm.

[0020] The internal reservoir may be manufactured from a material selected from non-alloyed and low alloyed steels, stainless steels, nickel-containing alloy steels with low thermal expansion coefficients, such as Invar®, and manganese-containing alloy steels with low thermal expansion coefficients, and aluminum.

[0021] Preferably, the internal reservoir is dimensioned to withstand a relative internal pressure of more than 200 kPa, or even more than 1000 kPa. Such dimensions allow the liquefied gas to be stored under pressure, allowing for extended storage periods without vapour leakage.

[0022] For this purpose, according to one embodiment, an internal reinforcement is attached to the inner surface 3 of the internal reservoir 2 .

[0023] The reinforcements are used to increase the pressure resistance of the internal reservoir 2. They may be manufactured in various ways. According to one embodiment, the internal reinforcements comprise protruding ribs on the inner surface 3. According to one embodiment, the corner ribs have a structure in the form of a circular arc rotated towards the inside of the internal reservoir 2, if the tank is of a rectangular parallelepiped shape.

[0024] According to one embodiment, for example shown in FIG. 9, the internal reinforcement comprises rods 11 extending between the two sides of the inner surface 3 so as to form a lattice structure 10 .

[0025] Examples of such lattice structures 10 are described, for example, in WO 2020 / 021212.

[0026] Unlike the tank with a rigid double jacket mentioned at the beginning, the outer sealing membrane 6 is not self-supporting but is made of sheet metal, the thickness of which is much thinner than the inner reservoir 2. According to one embodiment, the thickness of the outer sealing membrane 6 is less than 2 mm, for example equal to 1 or 1.5 mm.

[0027] The outer sealing membrane 6 can be made from various metals. According to one embodiment, the sheet metal is made from an alloy selected from non-alloyed and low-alloyed steels, stainless steels, nickel-containing alloys with a low coefficient of thermal expansion, and manganese-containing alloys with a low coefficient of thermal expansion.

[0028] In particular, the sheet metal can be made of Invar®, an alloy of iron and nickel, typically 1.2×10 -6 ~2×10 -6 K -1 It has a thermal expansion coefficient of about 64% iron and 36% nickel, or an alloy with a high manganese content, usually about 7-9 × 10 -6 K -1 The coil may be made of an iron alloy having a coefficient of expansion of 0.1.

[0029] The sheet metal forming the outer sealing membrane 6 is provided with bellows or corrugations 8. These bellows or corrugations 8 can project towards the inside of the tank 1, as in figure 1, or towards the outside of the tank 1, as in figure 2. Bellows or corrugations running alternately in both directions can also be used.

[0030] The bellows or corrugations 8 allow elastic deformation of the outer sealing membrane 6. The outer sealing membrane 6 is therefore capable of elastic deformation and can in particular follow the movements due to thermal contraction of the internal reservoir. According to one embodiment, the outer sealing membrane 6 has an elastic deformation capacity of more than 0.2% at ambient temperature in at least one direction perpendicular to the thickness, and preferably in any direction perpendicular to the thickness, and preferably has an elastic deformation capacity between 0.2 and 1.8%. The magnitude of deformation of the outer sealing membrane 6 is calculated based on the deformation of the internal reservoir 2, and is therefore performed by multiplying the thermal expansion coefficient of the internal reservoir 2 by the temperature change during operation. For example, an elastic deformation capacity of 0.3% is calculated by multiplying the thermal expansion coefficient of the internal reservoir 2 by the temperature change during operation. -6 This corresponds to the expansion coefficient of steel in mm / mm.K multiplied by 273K.

[0031] For this purpose, the outer sealing membrane 6 is provided with a series of parallel corrugations, or preferably two series of parallel corrugations, which are respectively in a cross or perpendicular direction in the mid-plane of the sheet metal. A sheet metal plate 15 comprising two series of corrugations is shown by way of example in FIG. 3. The sheet metal plate 15 consists, for example, of stainless steel with a thickness of 1.2 mm. The corrugations can be obtained by bending.

[0032] According to this embodiment, the outer sealing membrane 6 is corrugated and comprises a first series of parallel corrugations 16 and a flat portion 18 located between the parallel corrugations and placed on the insulating barrier 5, the parallel corrugations 16 being arranged parallel to a first direction.

[0033] Depending on the embodiment, the waveforms of the first and / or second series of waveforms may be continuous or discontinuous.

[0034] According to this embodiment, the outer sealing membrane 6 further comprises a second series of parallel corrugations 17 and a flat portion 18 located between the parallel corrugations 17 and resting on the insulating barrier 5, the parallel corrugations 17 being oriented perpendicular to the first direction.

[0035] The outer sealing membrane 6 can be produced over the entire required extent by assembling in a hermetically sealed manner several sheet metal plates 15 by lap welding. It is thus possible to obtain a corrugation that runs continuously from one sheet metal plate to the next over the entire surface covered by the outer sealing membrane 6.

[0036] Alternatively, the corrugations may be discontinuously formed, for example by stamping. An example of a metal membrane having discontinuous corrugations can be found, for example, in JP 55-139597 A.

[0037] Furthermore, the sheet metal plate 15 is generally flat and adapted to the plane of a polyhedral tank. It is of course understood that the sheet metal may be curved according to one or more radii of curvature depending on the shape of the tank wall to be covered, which may be for example spherical or cylindrical. The corrugations 16 and / or 17 may therefore follow a curved direction.

[0038] According to one embodiment, the outer sealing membrane 6 has a substantially spherical shape, for example the first direction corresponding to the parallel corrugations 17 is the meridian direction. According to one embodiment, the outer sealing membrane 6 has a substantially cylindrical shape, for example the first direction corresponding to the parallel corrugations 17 is the axial direction. According to one embodiment, the outer sealing membrane 6 has a substantially prismatic or parallelepiped shape, for example the first direction corresponding to the parallel corrugations 17 is the longitudinal direction.

[0039] An embodiment of the insulating barrier 5 is shown below. The insulating barrier 5 is attached to the internal reservoir 2 and the outer sealing membrane 6 is attached to the insulating barrier 5. The insulating barrier 5 is dimensioned to remain under vacuum even with some deformation, which should not exceed the elastic elongation capacity of the outer sealing membrane 6. The insulating barrier 5 preferably covers the entire outer surface 4 of the internal reservoir 2.

[0040] For this purpose, various structures and materials may be used: according to an embodiment, the thermal barrier 5 comprises a material selected from, for example, polyurethane, polyvinyl, polypropylene or polyethylene foams, whether or not reinforced with fibers, polymer foams such as melamine foams (also called BASOTECT® foams), mineral wool, polyester or cellulose waddings, perlite, fumed silica, compressed silica and aerogels.

[0041] According to one embodiment, the insulating barrier 5 is made of a material selected from mineral wool, polyester wadding and cellulose wadding, for example having a thickness of 200-400 mm, preferably 200-300 mm.

[0042] Such insulating materials can be deposited directly, without prior preparation, on the outer surface 4 of the internal reservoir 2. For example, glass wool or polyester wadding or cellulose wadding can be deposited directly on the outer surface 4 of the internal reservoir 2, for example in the form of parallel strips. According to another example, a polymer foam can be polymerized in situ directly over the entire outer surface 4 of the internal reservoir 2.

[0043] According to one embodiment, strips of glass wool or batting are joined together by stitching, for example using glass, composite or plastic threads.

[0044] According to one embodiment, the insulating barrier 5 is pre-compressed in its thickness direction between the internal reservoir 2 and the outer sealing membrane 6. This pre-compression can be applied by a mechanical coupler, which will be described below.

[0045] In particular, if the insulating barrier 5 is made of a compressible material such as mineral wool, polyester wadding, cellulose wadding, etc., the pre-compressive stress allows to better support the outer sealing membrane 6. It is, for example, between 0.1 MPa and 0.2 MPa.

[0046] Pre-compression refers to the stress that exists before the intermediate space is pressed down, which may exert additional compression on the insulating barrier 5 via the outer sealing membrane 6 .

[0047] Modular production of the insulation barrier 5 can facilitate standardization of how insulation is installed.

[0048] According to an embodiment, the insulating barrier 5 comprises an insulating element juxtaposed to the outer surface 4 of the internal reservoir 2 .

[0049] For example, in one embodiment shown in FIG. 4, the insulating element 20 comprises: a first plate 21 adjacent to the outer surface 4 of the internal reservoir 2; a second plate 22 parallel to the first plate 21 and spaced apart from the first plate 21 in the thickness direction of the insulation element 20 and adjacent to the outer sealing membrane 6; an insulating lining 23 arranged between the first plate and the second plate; Equipped with.

[0050] The insulating lining comprises, for example, a polymer foam having a relative density sufficient to withstand the small compressive forces associated with the pressure difference between the ambient atmosphere and the intermediate space and to allow for a safety margin. According to one embodiment, the relative density is less than 40 kg / m 3 from 90kg / m 3 and preferably between 40 kg / m 3 From 70kg / m 3 For example, between 50 kg / m 3 This may be, for example, a polyurethane, polyvinyl, or polyethylene or polypropylene foam, whether or not reinforced with glass fibers.

[0051] The plates 21 and 22 may be made of plywood or composite material. They may be glued to an insulating lining 23.

[0052] The juxtaposed insulating elements may have spaces between the panels. A seal must then be inserted in the space between the panels to ensure the continuity of the insulating barrier. The seal is made, for example, of glass wool. In other words, in the tank according to the invention, the insulating barrier 5 can exhibit a material continuity. The material continuity is ensured by an insulating material, such as an insulating lining. This barrier is filled with minimal spaces so that no gaps are left. The insulating barrier 5 is therefore continuous in all directions, i.e. through the thickness of the tank and perpendicular to this direction. This continuity is present in at least one layer of insulating material in the directions perpendicular and parallel to the surface of the tank.

[0053] In one embodiment, the insulating element comprises an insulating lining, for example made of the aforementioned materials, arranged in the form of a parallel layer on the outer surface of the internal reservoir, for example perlite, silica aerogel, or a mixture thereof.

[0054] In one embodiment, the support element extends up through the thickness of the insulating lining to absorb the forces. In an example applicable to the insulating element 20 shown in FIG. 4, the support element is arranged between a first plate 21 and a second plate 22, The insulating lining 23 is arranged between the support elements. Their presence may reduce the relative density of the insulating lining 23, since the support elements at least partially absorb the forces.

[0055] In another embodiment, for example as shown in Figure 5, the insulation element is manufactured in the form of a box 40 comprising a first plate 41, a second plate 42 and a side plate 43 extending between the first plate 41 and the second plate 42. The interior space of the box 40 is filled with an insulating lining.

[0056] Since the box 40 is subjected to compressive forces, the insulating lining (not shown) may be a non-structural material such as, for example, perlite, glass wool or other powder.

[0057] According to one embodiment, the support element comprises support partitions which divide the interior space into compartments filled with an insulating lining and which hold the first plate 41 at a distance from the second plate 42 .

[0058] Further details regarding the manufacture of such insulating barriers are described in WO 2017 / 064426.

[0059] The rigid elements of the insulating barrier 5, such as the box 40, the support elements or plates 21 and 22, may be made of plywood or composite material.

[0060] According to one embodiment, the thickness of the insulating barrier is greater than 200 mm, preferably between 200 mm and 800 mm.

[0061] To attach the insulating barrier to the internal reservoir, various solutions are possible.

[0062] According to one embodiment, the insulating barrier 5 is attached to the outer surface 4 of the internal reservoir 2 by adhesive bonding, preferably via a bead of mastic.

[0063] A bead of mastic 45 is shown, for example, in figure 5, which can be used to glue the box 40 to the outer surface 4. Such a bead of mastic also makes it possible to compensate for areas of the outer surface 4 that are not perfectly flat.

[0064] According to another embodiment, the exterior surface 4 of the internal reservoir 2 has a plurality of mechanical couplers, and the insulating barrier 5 is attached to the exterior surface 4 of the internal reservoir 2 by the mechanical couplers.

[0065] Such mechanical couplers can be used in particular with juxtaposed insulation elements. Thus, Fig. 5 shows an insulation element 40 and a mechanical coupler 35 arranged at each corner of the box 40. Such a mechanical coupler can hold the insulation element in place via any area of ​​the insulation element, for example to a bottom plate, a cover plate, etc. Thus, in Fig. 5, the mechanical coupler 35 interacts with a batten 36 resting on the plate 41. Other mechanical couplers can also be used, for example the couplers described in patent application FR 2 798 902.

[0066] For example, as seen in Figure 5, a mechanical coupler may be used in combination with an adhesive bond of the insulating barrier 5. It should also be noted that if a mechanical coupler is used, an adhesive bond is not required. A bead of mastic 45 may be used to compensate for flatness imperfections in the outer surface 4.

[0067] Another embodiment of a mechanical coupler 135 is shown in Figures 13 to 15. The mechanical coupler 135 comprises a rod 138 passing through the thickness of the insulating barrier 5 and an end piece 137 attached to one end of the rod 138 opposite the internal reservoir and abutting the outer surface of the insulating barrier 5. Preferably, the outer sealing membrane 6 is attached to the end piece 137.

[0068] More specifically, the mechanical coupler 135 includes a rod 138 and a first end piece 136 and a second end piece 137 disposed on either end of the rod 138. The rod 138 is attached to the first and second end pieces 136, 137 by, for example, screws or clips.

[0069] The mechanical coupler is made, for example, from a metal. It is preferable to use non-metallic materials, such as composite materials, especially for the rod 138, to limit heat conduction.

[0070] The first end piece 136 is attached to the outer surface 4 of the internal reservoir 2 and carries a rod 138. For example, the first end piece 136 is made of metal and attached by welding.

[0071] The second end piece 137 is attached to the other end of the rod 138 and has a wider cross section than the rod 138 so as to bear against the insulating barrier 5. The mechanical coupler 135 can thus exert pressure on the insulating barrier 5 and it comprises for example a plate or a washer. The second end piece 137 is made for example of a composite material or a plastic.

[0072] According to another embodiment, the second end piece 137 is made of metal, which also allows the outer sealing membrane 6 to be welded onto it. Thus, a mechanical coupler 135 may be used to hold both the insulating barrier 5 and the outer sealing membrane 6 in place.

[0073] 14 shows the interaction of the mechanical coupler 135 with the insulating barrier 5. In this embodiment, the mechanical coupler 135 passes through an insulating element 140 in the insulating barrier 5, which is, for example, a block of insulating foam or strips of glass wool or polyester batting.

[0074] 15 shows the interaction of a mechanical coupler 135 with an insulating barrier 5 in a second embodiment. In this case, the mechanical coupler 135 passes through an insulating element 141 located between two insulating elements 145. To press the adjacent insulating element 145 against the outer surface 4 of the internal reservoir 2 , the insulating element 141 has at each side portion a shoulder 142 which presses against a corresponding protrusion of the adjacent insulating element 145 .

[0075] Needless to say, the mechanical couplers 135 are present as multiple units, for example in the form of parallel rows of couplers or in the form of a grid with a square or rectangular mesh or the like, suitably arranged to hold the entire insulating barrier 5 on the internal reservoir 2. According to one embodiment, the mechanical couplers are spaced apart from each other at intervals of 0.5 m to 2 m. The mechanical couplers may or may not be used to hold the outer sealing membrane 6 in place. In one embodiment, some mechanical couplers perform this function and some do not.

[0076] To retain the outer sealing membrane 6 on the insulating barrier 5, various possibilities exist.

[0077] According to one embodiment, the insulating element carries, on its outer face opposite the internal reservoir, at least one metal part for attaching the outer sealing membrane to the insulating barrier by welding.

[0078] This embodiment is shown, for example, in FIG. 5, in which a metal fastening strip 46 is attached to the cover plate 42 of a box 40 .

[0079] According to a variant not shown, the fixing of the outer sealing membrane 6 is carried out using an insulating foam pad having a first end attached to the outer surface 4 of the internal reservoir 2. The insulating foam pad comprises a metal plate at a second end opposite to the first end. The metal plate is intended to attach the outer sealing membrane 6. For example, a protruding threaded rod is welded to the outer surface 4 of the internal reservoir 2 and the insulating foam pad is attached to the threaded rod, for example by screwing into a threaded hole of complementary shape.

[0080] As mentioned, the insulating barrier 5 is sealed between the internal reservoir 2 and the outer sealing membrane 6 and is located in an intermediate space containing a gas phase under reduced pressure. This reduced pressure, in other words a partial vacuum, can reduce heat transfer within the insulating barrier 5 and increase the insulating performance.

[0081] According to one embodiment, the gas phase under reduced pressure has an absolute pressure of less than 1 kPa (10 mbar), preferably less than 0.1 kPa (1 mbar), at a temperature of 15°C.

[0082] The reduction in the gas phase may, for example, cause the outer sealing membrane 6 to exert an additional compression of about 0.1 MPa on the insulating barrier 5 .

[0083] The outer sealing membrane 6 is thin and should not be used to support or suspend the tank 1.

[0084] Thus, according to one embodiment, the tank 1 is provided with a support system intended to support the tank within the installation, the support system comprising at least one support element having an internal part attached to the internal reservoir 2 and an external part extending outside the outer sealing membrane 6, the support element extending through the thickness of the insulating barrier 5 and passing sealingly through the outer sealing membrane 6.

[0085] According to one embodiment, a support element 50 is attached to the lower part of the internal reservoir 2, and the tank 1 is supported by the support element 50, as shown for example in Fig. 6. The facility is thus for example a floor wall 52 on which the tank 1 is supported via one or more support elements 50.

[0086] According to one embodiment, a support element 51 is attached to the top of the internal reservoir 2 and the tank 1 is suspended by the support element 51, as shown for example in Fig. 7. Thus, the installation is for example a ceiling wall 53, below which the tank 1 is suspended via one or more support elements 51.

[0087] Apart from the positions shown in Figures 6 and 7, similar support elements can be arranged in any suitable position on the internal reservoir 2. Thus, the tank 1 can also be attached to a vertical wall by supports extending horizontally from one or more sides of the internal reservoir 2.

[0088] FIG. 8 shows an embodiment of a support leg 60 that can be used to manufacture the support element 50 or 51. The support leg 60 comprises a base 61 attached, for example welded, to the outer surface 4 between the insulating elements forming the insulating barrier 5, which in this case is the box 40. The base 61 extends from the outer surface 4 through the thickness of the insulating barrier 5 to the height of the outer sealing membrane 6. The base 61 supports a metal sealing plate 62, which allows the entire contour of the opening made in the outer sealing membrane 6 (not shown) to be hermetically welded. According to a variant, the base 61 is formed from an insulating material, for example made of wood or fiberglass composite, that can support the metal sealing plate 62. This embodiment is advantageous in that it reduces thermal bridges that may impair the quality of the insulation.

[0089] The metal sealing plate 62 carries one or more legs 63 which protrude beyond the outer sealing membrane 6 and enable it to interact with the floor wall 52 or the ceiling wall 53, depending on the position of the support legs 60 on the internal reservoir 2. Further details regarding the manufacture of such support legs are described in WO 2017 / 174938.

[0090] FIG. 12 shows another embodiment of the support system. The support system is a support leg 160 with a first internal part 161 and a second external part 163 with a metal sealing plate 162 arranged between them. The first internal part 161 is located between the outer surface 4 of the internal reservoir 2 and the inner surface of the sealing membrane 6. The second external part 163 extends from the outer surface 7 of the sealing membrane 6 to the outer support 90, for example the floor. The first part 161 is for example a wooden or fiberglass wedge attached to the internal reservoir 2 and extending to the outer sealing membrane 6. The internal reservoir 2 rests on the first part 161. This first part thus makes it possible in particular to limit thermal bridges through the insulating barrier 5. The second part 163 is for example a metallic support arranged facing the first part. The support leg 160 therefore makes it possible to support the weight or part of the weight of the tank without crushing or deforming the insulation of the insulating barrier 5. The number of support legs and the dimensions of the first part 161 and the second part 163 are selected taking into account the shape and weight of the tank. If several support legs 160 are required, their dimensions may be the same or different from each other. To better support the weight of the shell 2, a metal part may be inserted between the part 161 and the shell 2. This is not shown.

[0091] Also shown in FIG. 12 is a weld zone 95 for connecting the outer sealing membrane 6 to the metal sealing plate 162 .

[0092] As mentioned above, the tank 1 can have various shapes. A spherical tank is shown diagrammatically in figure 10. The portion 55 of the support element 50 is shown in dashed lines to make it clear that it penetrates the thickness of the insulating barrier 5, as already explained.

[0093] Such tanks can be used to store various liquefied gases, for example liquefied natural gas, liquefied petroleum gas, ammonia, etc. Preferably, the sealed, insulated tank is intended to contain hydrogen.

[0094] Tanks of this type can form part of an onshore storage facility, for example for storing LNG, or can also be installed on floating, coastal or deep sea structures, in particular LNG carriers, Floating Storage and Regasification Units (FSRUs), Floating Production Storage and Offloading (FPSOs), etc. According to one embodiment, the onshore storage facility is intended to supply gas to electrical or thermal energy production devices, for example to supply electricity or heat to a city, or to supply gas to a network, for example to supply natural gas to a city.

[0095] In particular, in land, air or sea vehicles equipped with propulsion or energy generating devices, the sealed insulated tank 1 can serve as a fuel reservoir for the propulsion or energy generating devices, as shown in FIG. 11 with reference to a transport vessel 70.

[0096] According to one embodiment, a liquefied gas fuel transfer system includes the vehicle described above, an insulated pipeline arranged to connect a fuel reservoir of the vehicle to a floating or on-shore storage facility, and a pump for pumping a flow of liquefied gas fuel from the floating or on-shore storage facility through the insulated pipeline to the fuel reservoir.

[0097] In the vehicle loading method described above, liquefied gas fuel is transported through an insulated pipeline from a floating or land-based storage facility to the vehicle's fuel reservoir.

[0098] For example, referring to FIG. 11, a vessel 70 includes a sealed, insulated tank 1, for example of generally prismatic shape, mounted on the vessel's hull 72.

[0099] In a manner known per se, a loading / unloading pipeline arranged on the upper deck of the transport vessel can be connected by a transfer line 73 to a port terminal 75 to transfer a cargo of liquefied gas fuel to the tanks 1 .

[0100] Pumps on board the transport vessel 70 and / or pumps attached to the port terminal 75 are used to generate the pressure required for transport of the liquefied gas.

[0101] Although the present invention has been described with reference to some specific embodiments, it is in no way limited thereto, and it is clear that the present invention encompasses all technical equivalents of the described means and combinations thereof, provided they fall within the scope of the present invention.

[0102] Use of the verb "comprise" or "comprise" and its conjugations does not exclude the presence of other elements or steps in addition to those stated in a claim.

[0103] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

Claims

1. A sealed, insulated tank (1) for storing and / or transporting liquefied gas, the tank having, from the inside to the outside, successively: a sealed, self-supporting internal reservoir (2) having an inner surface intended to be in contact with the liquefied gas and an outer surface; an insulating barrier (5) covering the outer surface of the internal reservoir and attached to the internal reservoir; an outer sealing membrane (6) covering the outer surface of the thermal barrier and comprising a piece of sheet metal with bellows or corrugations (8) to allow elastic deformation, attached to the thermal barrier or the internal reservoir; Equipped with an intermediate space located between the internal reservoir and the outer sealing membrane contains a gas phase under reduced pressure to press the outer sealing membrane (6) against the outer surface of the insulating barrier (5); The reduced pressure is the difference between the pressure in the intermediate space and atmospheric pressure. A sealed insulated tank (1).

2. 2. The sealed, insulated tank according to claim 1, characterized in that the internal reservoir (2) comprises a metal shell having a thickness of more than 10 mm.

3. 3. The sealed insulated tank according to claim 1, wherein the internal reservoir (2) is made of a material selected from the group consisting of non-alloy steel, low-alloy steel, stainless steel, alloy steel containing nickel with a low thermal expansion coefficient, alloy steel containing manganese with a low thermal expansion coefficient, and aluminum.

4. 3. The sealed insulated tank according to claim 1 or 2, characterized in that an internal reinforcement (11) is attached to the inner surface of the internal reservoir.

5. 5. The tank according to claim 4, characterized in that the internal reinforcement (11) comprises ribs projecting on the inner surface (3).

6. The internal reservoir (2) is dimensioned to withstand a relative internal pressure of more than 200 kPa.

3. The sealed insulated tank according to claim 1 or 2.

7. the tank further comprises a support system (50, 51, 60, 160) intended to support the tank within an installation (52, 53); The support system comprises at least one support element (60) having an internal portion (61, 161) attached to the internal reservoir and an external portion (63, 163) extending outside the outer sealing membrane (6); The support element (60) extends through the thickness of the insulating barrier (5) and hermetically passes through the outer sealing membrane (6).

3. The sealed insulated tank according to claim 1 or 2.

8. The support element (50) is attached to the lower part of the internal reservoir; The tank is supported by the support element.

8. The sealed, insulated tank according to claim 7.

9. The support element (51) is attached to the top of the internal reservoir, The tank is suspended by the support element 8. The sealed, insulated tank according to claim 7.

10. The thermal barrier (5) comprises a material selected from polymer foam, mineral wool, polyester or cellulose wadding, perlite, fumed silica, compressed silica and aerogel.

3. The sealed insulated tank according to claim 1 or 2.

11. The thermal barrier (5) is made of a material selected from mineral wool, polyester wadding, and cellulose wadding.

3. The sealed insulated tank according to claim 1 or 2.

12. The insulating barrier (5) is pre-compressed in its thickness direction between the internal reservoir (2) and the external sealing membrane (6).

3. The sealed insulated tank according to claim 1 or 2.

13. The insulating barrier comprises an insulating element (20, 40) juxtaposed to the outer surface of the internal reservoir.

3. The sealed insulated tank according to claim 1 or 2.

14. The insulating element (40) comprises an insulating lining arranged in a layer parallel to the outer surface of the internal reservoir.

14. The sealed, insulated tank according to claim 13.

15. The insulating element is manufactured in the form of a box (40), The box includes a first plate (41), a second plate (42), and a side plate (43) extending between the first plate and the second plate to surround an interior space of the box; The interior space of the box is filled with the insulating lining.

14. The sealed, insulated tank according to claim 13.

16. The insulating element carries, on its outer surface opposite the internal reservoir, at least one metal part (46) for attaching the outer sealing membrane onto the insulating barrier by welding.

14. The sealed, insulated tank according to claim 13.

17. The thickness of the thermal barrier (5) is between 200 mm and 800 mm 3. The sealed insulated tank according to claim 1 or 2.

18. a plurality of mechanical couplers (35, 135) attached to the outer surface (4) of the internal reservoir; The insulating barrier (5) is attached to the outer surface of the internal reservoir by the mechanical coupler (35, 135).

3. The sealed insulated tank according to claim 1 or 2.

19. The mechanical coupler (135) a rod (138) penetrating the insulating barrier (5) in the thickness direction; an end piece (137) attached to one end of the rod (138) opposite the internal reservoir and attached to the outer surface of the insulating barrier (5); Equipped with 20. The sealed, insulated tank of claim 18.

20. The outer sealing membrane (6) is attached to the end piece (137) 20. The sealed, insulated tank of claim 19.

21. The thickness of the outer sealing membrane (6) is less than 2 mm 3. The sealed insulated tank according to claim 1 or 2.

22. 3. The tank according to claim 1, wherein the sheet metal is made of an alloy selected from the group consisting of non-alloy and low-alloy steels, stainless steels, nickel-containing alloy steels with a low coefficient of thermal expansion, and manganese-containing alloy steels with a low coefficient of thermal expansion.

23. The outer sealing membrane (6) is corrugated, The outer sealing membrane (6) a first series of parallel waveforms (16); a portion located between the parallel corrugations and overlying the insulating barrier; Equipped with The parallel corrugations are arranged parallel to a first direction.

3. The sealed insulated tank according to claim 1 or 2.

24. The outer sealing membrane further comprises: a second series of parallel waveforms (17); a flat portion located between the parallel corrugations and resting on the insulating barrier; Equipped with The parallel corrugations are arranged perpendicular to the first direction.

24. The sealed, insulated tank of claim 23.

25. the outer sealing membrane (6) has a substantially spherical shape and the first direction is a meridian direction, or the outer sealing membrane has a generally cylindrical shape and the first direction is an axial direction; or The outer sealing membrane has a generally parallelepiped shape, and the first direction is a longitudinal direction.

24. The sealed, insulated tank of claim 23.

26. The outer sealing membrane (6) has an elastic deformation capacity of more than 0.2% at ambient temperature in at least one direction perpendicular to the thickness, preferably in any direction perpendicular to the thickness, and preferably has an elastic deformation capacity of 0.2 to 1.8%.

3. The sealed insulated tank according to claim 1 or 2.

27. The gas phase under reduced pressure has an absolute pressure of less than 1 kPa (10 mbar), preferably less than 0.1 kPa (1 mbar) at a temperature of 15° C.

3. The sealed insulated tank according to claim 1 or 2.

28. A land-based storage facility comprising the sealed insulated tank according to claim 1 or 2.

29. A land, air or sea vehicle, in particular a transport ship (70), a propulsion or energy generating device; A sealed, insulated tank (1) according to claim 1 or 2 as a fuel reservoir for the propulsion or energy generating device; A transport vessel (70) comprising:

30. 3. Use of a sealed, insulated tank (1) according to claim 1 or 2 for storing and / or transporting hydrogen.

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