Sealed and heat insulated structure

Abstract

The invention relates to a structure comprising a first sealing wall (3) and a second sealing wall (2) positioned spaced apart from the first sealing wall (3) and an intermediate space (4) arranged between the first sealing wall (3) and the second sealing wall (2), where the intermediate space (4) comprises: a porous separator (5); an extraction region (7) between the porous separator (5) and the second sealing wall (2); a particle region (14) located between the porous separator (5) and the first sealing wall (3), the particle region (14) being filled with a particulate barrier filler, the porous separator having a pore size that is smaller than the particle size of the particulate barrier filler, and the extraction region having a resistance to the passage of gas molecules that is smaller than the resistance to the passage of gas molecules through the particle region.

Description

Field of the Invention

[0001] The present invention relates to the field of sealed and thermally insulated structures for storing and / or transporting liquefied gases at low temperatures, such as tanks for transporting liquefied hydrogen, which is at approximately -253 °C at atmospheric pressure, but which can also be stored at higher pressures. These tanks can be installed in a fixed position or on any land-based or floating vehicle. Background Art

[0002] Self-supporting tanks and membrane tanks for storing and / or transporting liquefied gases are known in the art.

[0003] In order to keep the gas in liquid form inside the tank, it is important for the tank to exhibit excellent thermal insulation properties, in particular to limit the evaporation of the liquefied gas contained in the tank.

[0004] The tank includes, for example, a double wall insulated with granular insulating filler, such as perlite or glass microspheres. In such a tank, the granular insulating filler fills the entire space between the double walls.

[0005] It is known from the literature, for example, "Glass bubbles insulation for liquid hydrogen storage tanks", J.P. Sass, W.W. St. Cyr, T.M. Barrett, R.G. Baumgartner, J.W. Lott and J.E. Fesmirel, June 30, 2009, that in order to improve the thermal insulation properties of the tank, the pressure in the intermediate space of the double wall containing the granular insulating filler can be reduced, in which case the granular insulating filler is glass microspheres.

[0006] However, due to the significant pressure losses generated by the granular insulating filler, the method of evacuating this intermediate space with a vacuum pump to create a vacuum is a long and energy-consuming process. In other words, it is difficult to pump out all of the air initially present in the intermediate space. By way of example, for a type C tank (as defined by the International Maritime Organization IGC code) with an intermediate space volume of 3500 m 3 it takes 125 days of pumping to reach a pressure of 6 Pa in this space. Summary of the Invention

[0007] One concept on which the present invention is based is to solve the above problems.

[0008] Another concept on which the present invention is based is to provide a sealing structure that includes an intermediate space which includes a gaseous phase in vacuum to obtain excellent thermal insulation performance.

[0009] Another concept on which the present invention is based is to provide a sealed and thermally insulated structure having an intermediate space that can be evacuated more quickly.

[0010] Another concept on which the present invention is based is to provide a method for evacuating the intermediate space of a sealed and thermally insulated structure, in particular a method in which evacuation is accelerated compared to currently known vacuum evacuation methods.

[0011] According to one embodiment, the present invention provides a sealed and thermally insulated structure for the storage or transportation of liquefied gas, the structure comprising: a first sealing wall; and a second sealing wall spaced apart from the first sealing wall; a thermally insulated intermediate space located between the first sealing wall and the second sealing wall, the intermediate space being adapted and configured to be set in vacuum,

[0012] wherein the intermediate space includes:

[0013] a first porous separator;

[0014] a first extraction region located between the first porous separator and the second sealing wall,

[0015] a particle region located between the first porous separator and the first sealing wall, the particle region being filled with particulate thermal insulation filler,

[0016] wherein the first porous separator has pores sized smaller than the particle size of the particulate insulation filler to retain the particulate thermal insulation filler within the particle region,

[0017] wherein the first extraction region has a resistance to the passage of gas molecules that is less than the resistance to the passage of gas molecules in the particle region.

[0018] In other words, the first extraction region has a resistance to the flow of gas molecules that is less than the resistance present in an intermediate space that is completely filled with particulate thermal insulation filler and has no extraction regions.

[0019] Due to these features, the structure exhibits excellent thermal insulation performance. Furthermore, due to such a first extraction region, the pressure loss in the intermediate space is reduced, thus allowing for faster evacuation. Accordingly, the gaseous phase in the intermediate space can be evacuated and removed via a vacuum pump, which is advantageously connected to the first extraction region. This structure enables a significant reduction in the pumping time required to reach vacuum, reducing the time of several months in the prior art to a few days in the present invention.

[0020] According to the present invention, "particle size" refers to the average size of the particles of the particulate insulating filler, in other words, the average equivalent diameter of the particulate insulating filler. Thus, "the size of the pores is smaller than the particle size of the particulate insulating filler" means that the pores of the porous separator must have a size, such as an average equivalent diameter, that is smaller than the average equivalent diameter of the particles, thereby allowing prevention of the particulate insulating filler from entering the extraction region through the porous separator.

[0021] According to an embodiment, such a structure may include one or more of the following features.

[0022] According to one embodiment, the first extraction region includes a first porous insulating layer having interconnected open pores, the interconnected open pores having a size larger than the size of the open pores of the particulate thermal insulating filler, and the first porous insulating layer having a porosity larger than the porosity of the particulate thermal insulating filler. Thus, the pressure loss in the intermediate space is reduced, enabling faster exhaust.

[0023] According to one embodiment, the first extraction region does not include a thermal insulating material. That is, except for any possible means for stabilizing the first porous separator, the first extraction region is not filled with a material that would increase the resistance to the passage of gas molecules.

[0024] According to one embodiment, the thickness of the extraction region is at least 1 mm, preferably at least 10 mm, and more preferably at least 100 mm, for example, between 100 mm and 500 mm.

[0025] According to one embodiment, the extraction region has an open porosity greater than 96%.

[0026] According to one embodiment, the extraction region has a Knudsen number (Kn) smaller than that of the particulate region.

[0027] According to one embodiment, at 296 Kelvin (K), for a gas at the target pressure, the extraction region has a Kn less than or equal to 0.5, preferably, the extraction region has a Kn less than 0.1. According to one embodiment, for nitrogen, at 296 Kelvin (K), at a pressure between 10 Pa and 200 Pa, the extraction region has a Kn less than or equal to 0.5, preferably, the extraction region has a Kn less than 0.1.

[0028] According to one embodiment, the particulate insulating filler includes particles having an average equivalent diameter greater than 110% of the average equivalent diameter of the pores of the porous separator.

[0029] According to one embodiment, the porous separator has a pore size distribution that allows the porous separator to be plugged by particulate thermal insulation filler. The porous separator has a retention threshold that is less than 90% of the average particle diameter of the particulate thermal insulation filler, preferably the porous separator has a retention threshold that is less than 75% of the average particle diameter of the particulate thermal insulation filler, and more preferably the porous separator has a retention threshold that is less than 50% of the average particle diameter of the particulate thermal insulation filler.

[0030] According to another embodiment, the porous separator has a retention threshold that is less than 50 μm (micrometers), preferably, the porous separator has a retention threshold that is less than 15 μm.

[0031] According to one embodiment, the intermediate space includes a second porous separator spaced apart from the first sealing wall and a second extraction region located between the second porous separator and the first sealing wall. The particulate region is located between the first porous separator and the second porous separator.

[0032] Wherein, the second porous separator has pores with a size smaller than the particle size of the particulate thermal insulation filler, and wherein the second extraction region has a lower resistance to the passage of gas molecules than the resistance of the gas molecules passing through the particulate region.

[0033] In a variant, the second extraction region includes a second porous insulating layer.

[0034] And, the second porous insulating layer has interconnected open pores, the interconnected open pores have a size larger than the size of the open pores of the particulate thermal insulation filler, and the second porous insulating layer has a porosity greater than the porosity of the particulate thermal insulation filler.

[0035] According to one embodiment, the second extraction region does not include thermal insulation material. That is, except for any possible means for stabilizing the second porous separator, the second extraction region is not filled with materials that would increase the resistance to the passage of gas molecules.

[0036] According to one embodiment, the first porous separator includes: a sheet, the sheet is perforated through the thickness of the sheet; an expanded metal sheet; a metal mesh; a composite material plate, the composite material plate is perforated through the thickness of the composite material plate; a composite material plate made of fibers bonded together, and the composite material plate has an open porosity greater than 30% of the volume of the composite material plate.

[0037] According to one embodiment, the second porous separator includes: a sheet, the sheet is perforated through the thickness of the sheet; an expanded metal sheet; a metal mesh; a composite material plate, the composite material plate is perforated through the thickness of the composite material plate; a composite material plate made of fibers bonded together, and the composite material plate has an open porosity greater than 30% of the volume of the composite material plate.

[0038] According to one embodiment, the first porous separator or the second porous separator is fixed to one of the first sealing wall and the second sealing wall via a fastening device. According to one embodiment, the fastening device is selected from bolts or rivets.

[0039] According to one embodiment, the first porous separator includes a rigid mesh fixed to one of the first sealing wall and the second sealing wall.

[0040] According to one embodiment, the second porous separator includes a rigid mesh fixed to one of the first sealing wall and the second sealing wall.

[0041] According to one embodiment, the mesh is: a sheet, the sheet being perforated through the thickness of the sheet; an expanded metal sheet; a metal mesh; a composite board, the composite board being perforated through the thickness of the composite board; or, a composite board made of fibers bonded together, and the composite board having an open porosity greater than 30% of the volume of the composite board.

[0042] According to one embodiment, the first porous separator or the second porous separator includes a plurality of meshes.

[0043] According to one embodiment, each of the meshes in the plurality of meshes includes a central portion and two side portions, the side portions protruding from each end of the central portion toward the first wall or the second wall. According to one embodiment, the two side portions protrude perpendicularly from the central portion.

[0044] According to one embodiment, the first porous separator includes a fabric covering and attached to the mesh, the fabric having pores with a size smaller than the particle size of the particulate insulating filler.

[0045] According to one embodiment, the second porous separator includes a fabric covering and attached to the mesh, the fabric having pores with a size smaller than the particle size of the particulate insulating filler.

[0046] According to one embodiment, the fabric is fixed to the mesh via a fastening device. According to one embodiment, the fastening device is selected from: adhesive strips such as type strips, glue, rivets, bolts, and sewing threads.

[0047] According to one embodiment, the fabric is selected from:

[0048] - fibers based on polyethylene terephthalate (PET) fibers, mineral fibers such as glass fibers and metal fibers;

[0049] - paper based on mineral fibers;

[0050] - A web or non-woven felt made of polymer fibers such as PET or polypropylene, or a web or non-woven felt made of mineral fibers such as glass fibers.

[0051] According to one embodiment, the fabric has a filtration threshold of less than 30 μm, and more preferably, the fabric has a filtration threshold of less than 15 μm.

[0052] According to one embodiment, the first insulating layer comprises glass wool.

[0053] According to one embodiment, the second insulating layer comprises glass wool.

[0054] According to one embodiment, the glass wool has a pore size between 0.5 mm and 2 mm.

[0055] According to one embodiment, the glass wool has a porosity in the range between 98% and 99.5%.

[0056] According to one embodiment, the particulate thermal insulation filler is selected from: perlite, hollow glass microspheres, fumed silica, particulate aerogels such as silica aerogel or a mixture of at least two of these materials.

[0057] According to one embodiment, the particulate thermal insulation filler has an open porosity level of less than 97%, or less than 75%, or less than 45%.

[0058] According to one embodiment, the particulate aerogel has an open porosity level between 94% and 97%.

[0059] According to one embodiment, the perlite has an open porosity level between 75% and 97%.

[0060] According to one embodiment, the fumed silica has an open porosity level between 94% and 97%.

[0061] According to one embodiment, the glass microspheres have an open porosity level between 30% and 45%.

[0062] According to one embodiment, the particulate thermal insulation filler has a particle size of less than 4000 μm, and preferably, the particulate thermal insulation filler has a particle size of less than 2000 μm.

[0063] According to one embodiment, the perlite has a particle size greater than 50 μm, for example, the perlite has a particle size between 500 μm and 1500 μm.

[0064] According to one embodiment, the particulate aerogel has a particle size greater than 50 μm. For example, the particulate aerogel has an average diameter between 1000 μm and 2000 μm.

[0065] According to one embodiment, the hollow glass microspheres have a diameter greater than 30 μm and an average diameter of 65 μm. For example, reference K1 from 3M can be used, where 90% have a diameter greater than 30 μm and an average diameter of 65 μm.

[0066] According to one embodiment, the fumed silica includes aggregates greater than 200 μm.

[0067] According to one embodiment, the structure includes a vacuum pump connected to a first extraction region.

[0068] According to one embodiment, the structure includes a vacuum pump connected to a second extraction region.

[0069] According to one embodiment, when the structure is filled with liquefied gas, the intermediate space has a gas phase with an absolute pressure less than 10 Pa. Preferably, the intermediate space has a gas phase with an absolute pressure less than 1 Pa.

[0070] The pressure shown above is the final pressure required after the internal space defined by the first sealing wall is filled with liquefied gas. This pressure is achieved by combining the continuous operation of the vacuum pump and the pumping of a part of the remaining gas by a cryopump onto the cooled wall.

[0071] According to one embodiment, the first sealing wall is for contact with the liquefied gas, and the second sealing wall is disposed outside the first sealing wall.

[0072] According to one embodiment, the structure is in the form of a tank for storing liquefied gas.

[0073] According to one embodiment, the tank is a self - supporting tank.

[0074] According to one embodiment of the self - supporting tank, the second sealing wall and the first sealing wall are self - supporting, and the second sealing wall and the first sealing wall are supported by support members that pass through the second sealing wall to support the first sealing wall.

[0075] According to another embodiment, the tank is a membrane tank, the second sealing wall is a load - bearing structure, and the first sealing wall is a sealing membrane supported by a plurality of support elements. The support elements are positioned in the intermediate space and extend between the second sealing wall and the first sealing wall.

[0076] According to one embodiment, the plurality of support elements includes support columns.

[0077] According to one embodiment, the structure is in the form of a pipeline for transporting liquefied gas.

[0078] According to one embodiment of a structure in the form of a pipeline, the first sealing wall and the second sealing wall extend in the longitudinal direction of the structure, and the first sealing wall forms an internal space for contacting with liquefied gas. The internal space includes a through hole extending from a first longitudinal end of the structure to a second longitudinal end of the structure in the longitudinal direction of the structure to allow the transportation of liquefied gas.

[0079] According to one embodiment, before the internal space is cooled and filled with liquefied gas, the gas phase in the intermediate space is at an absolute pressure less than 300 Pa, preferably the gas phase in the intermediate space is at an absolute pressure less than 100 Pa.

[0080] This refers to the maximum pressure defined at ambient temperature before the internal tank is cooled and filled with liquefied gas. When the atmospheric pressure in the isolation space is at 1.10 5 Pa, this pressure level allows the thermal conductivity of the granular isolation packing to be reduced by 50% to 90% of the initial conductivity. Therefore, this reduction in thermal conductivity enables the start of cooling and filling with liquefied gas while limiting the evaporation rate of the liquefied gas caused by the cooling of the tank.

[0081] According to one embodiment, the liquefied gas is selected from: liquefied natural gas (LNG), helium, oxygen (LOx), argon, and preferably hydrogen (LH2).

[0082] According to one embodiment, the present invention also provides a method for exhausting a sealed and thermally insulated structure for storing or transporting liquefied gas, the method comprising:

[0083] - providing a sealed and thermally insulated structure for storing or transporting liquefied gas, the structure comprising:

[0084] a first sealing wall, the first sealing wall forming an internal space for contacting with liquefied gas;

[0085] a second sealing wall, the second sealing wall being positioned spaced apart from the first sealing wall,

[0086] a thermally insulated intermediate space, the intermediate space being provided between the first sealing wall and the second sealing wall,

[0087] wherein the intermediate space has a gas phase and includes:

[0088] a first porous separator;

[0089] a first extraction region, the first extraction region being located between the first porous separator and the second sealing wall,

[0090] The particulate region is located between the first porous separator and the first sealing wall, and the particulate region is filled with particulate thermal insulation filler.

[0091] Wherein, the first porous separator has pores with a size smaller than the particle size of the particulate insulation filler to retain the particulate thermal insulation filler within the particulate region.

[0092] And wherein, the first extraction region has a resistance to the passage of gas molecules, the resistance being less than the resistance to the passage of gas molecules in the particulate region, and

[0093] - Before cooling and filling the internal space with liquefied gas, the pressure in the intermediate space is reduced by a vacuum pump connected to the first extraction region until the gas phase in the intermediate space reaches an absolute pressure less than 200 Pa, preferably until the gas phase in the intermediate space reaches an absolute pressure less than 50 Pa, more preferably until the gas phase in the intermediate space reaches an absolute pressure less than 10 Pa.

[0094] According to an embodiment of the method, the structure includes the second extraction region as described above, and the method further includes:

[0095] Before cooling and filling the internal space with liquefied gas, the pressure in the intermediate space is reduced by a vacuum pump leading to the second extraction region until the gas phase in the intermediate space reaches an absolute pressure less than 200 Pa, preferably until the gas phase in the intermediate space reaches an absolute pressure less than 100 Pa in order to obtain the structure as described above.

[0096] According to an embodiment of the method, the pressure in the intermediate space is reduced to a pressure less than 50 Pa, preferably, the pressure in the intermediate space is reduced to a pressure less than 10 Pa.

[0097] According to an advantageous embodiment of the method, in addition to the above-mentioned vacuum pump, a cryopump pumping effect is used to achieve the target vacuum level in the intermediate space.

[0098] According to an embodiment of the method, before being evacuated, the intermediate space is filled with an inert gas having a solid condensation temperature higher than the liquefaction temperature of the liquefied gas stored in the structure. For example, when the liquefied gas stored in the tank is liquid hydrogen, the inert gas can be carbon dioxide. Thus, given the temperature of the hydrogen in the liquid state, the carbon dioxide present in the intermediate space condenses into a solid state within the intermediate space, thereby contributing to reducing the pressure in the intermediate space.

[0099] According to an embodiment, the present invention also provides a ship for transporting liquefied gas, the ship including the structure described previously.

[0100] According to one embodiment, the present invention further provides a transfer system for transferring liquefied gas, the system comprising: the aforementioned ship; an isolation pipeline arranged to connect a structure installed in the hull of the ship to a floating or land-based storage facility; and a pump configured to drive liquefied gas from the floating or land-based storage facility through the isolation pipeline to the structure of the ship or to drive liquefied gas from the structure of the ship through the isolation pipeline to the floating or land-based storage facility.

[0101] According to one embodiment, the present invention further provides a method for loading or unloading the aforementioned ship, wherein liquefied gas is transported from a floating or land-based storage facility to the structure of the ship or from the structure of the ship to a floating or land-based storage facility through the isolation pipeline.

[0102] According to one embodiment, at least one of the isolation pipelines in the aforementioned transfer system for transferring liquefied gas or the aforementioned method for loading or unloading is a structure in the form of the aforementioned pipeline. Description of the Drawings

[0103] The present invention will be better understood from the following description of specific embodiments of the present invention given by way of example only and not by way of limitation with reference to the accompanying drawings, and other objects, details, features and advantages of the present invention will become clearer.

[0104] Figure 1 is a cross-sectional view of a self-supporting structure according to one embodiment.

[0105] Figure 2 is a cross-sectional view of a structure in the form of a membrane tank according to another embodiment.

[0106] Figure 3 is a cross-sectional view along an axis perpendicular to the longitudinal direction of a structure in the form of a pipeline according to another embodiment.

[0107] Figure 4 is a schematic cross-sectional view of a ship structure and a loading / unloading terminal for the structure.

[0108] Figure 5 is according to one embodiment of Figure 1 an enlarged cross-sectional view of region I shown in

[0109] Figure 6 shows Figure 5 a top view of the embodiment shown in

[0110] Figure 7 is according to another embodiment of Figure 1 an enlarged cross-sectional view of region I shown in

[0111] Figure 8shows Figure 7 a top view of an embodiment in

[0112] Figure 9 is an enlarged cross-sectional view of region I shown in Figure 1 according to another embodiment. Detailed Embodiment

[0113] The first embodiment is shown in Figure 1 and shows a sealed and thermally insulated structure 1 for storing liquefied gas. This structure takes the form of a self-supporting tank.

[0114] Structure 1 includes a first sealing wall 3, a second sealing wall 2, and a porous separator 5 located between the first sealing wall 3 and the second sealing wall 2. The second sealing wall 2 is located outside the first sealing wall 3.

[0115] The first sealing wall 3 is positioned at a distance from the inner surface 22 of the second sealing wall 2. The first sealing wall 3 has an inner surface 32 which defines an internal space 9 for storing liquefied gas, such as liquid hydrogen.

[0116] The first sealing wall 3 has an outer surface 31 which, together with the inner surface 22 of the outer sealing wall 2, defines an intermediate space 4 which is thermally insulated and in a vacuum.

[0117] The second sealing wall 2 and the first sealing wall 3 are self-supporting, in other words, the second sealing wall 2 and the first sealing wall 3 are rigid and maintain their own structure by balancing their own weight. The second sealing wall 2 and the first sealing wall 3 are supported by support members 6, for example, the second sealing wall 2 and the first sealing wall 3 are supported by beams. The support members 6 include spacers 61 which extend through the intermediate space 4 to support the first sealing wall 3.

[0118] The intermediate space 4 includes a porous separator 5 which is spaced from and fixed to the inner surface 22 of the second sealing wall 2. The method of attachment of the porous separator will be described in more detail below.

[0119] The porous separator includes, for example, a mesh, a fabric, or a combination of a mesh and a fabric.

[0120] The intermediate space 4 also includes an extraction region 7 which is located between the first porous separator 5 and the inner surface 22 of the second sealing wall 2. The extraction region 7 is used to be evacuated via a vacuum pump (not shown) so that the entire intermediate space 4 is in a vacuum. For this purpose, the extraction region 7 is connected to the vacuum pump via a conduit 17, as Figure 1 shown in

[0121] The intermediate space 4 includes a particle area 14, which is located between the porous separator 5 and the outer surface 31 of the inner sealing wall 3. The particle area 14 is filled with granular thermal insulation filler, such as perlite, hollow glass microspheres, fumed silica, silica aerogel, or a mixture of at least two of these examples.

[0122] The extraction zone 7 comprises a porous thermal insulation layer, such as a glass wool layer, arranged between the porous separator 5 and the inner surface 22 of the second sealing wall 3 .

[0123] The porous separator 5 has pores whose size is smaller than the particle size of the granular thermal insulation filler so as to retain the granular thermal insulation filler in the granular region 14 .

[0124] In the example shown and similar to Figure 1 In the variant of Figure 1 The intermediate space 14 in the separator includes a second porous separator and a second extraction region, the second porous separator being spaced apart from and fixed to the outer surface 31 of the first sealing wall 3, the second extraction region being located between the second porous separator and the outer surface 31 of the first sealing wall 3. The particle region 14 is located between the porous separator 5 and the second porous separator, the second extraction region including a second porous insulating layer maintained between the second porous separator and the outer surface 31 of the first sealing wall 3. The second porous separator has pores of a size smaller than the particle size of the granular insulating filler in a manner similar to the porous separator 5, whereas the second porous insulating layer has pores of a size larger than the particle size of the granular insulating filler.

[0125] Advantageously, the thickness of the extraction zone is at least 1 mm, preferably at least 10 mm, and more preferably at least 100 mm.

[0126] In a variant that is not shown, the extraction region does not comprise thermal insulation material.

[0127] for Figure 2 and Figures 5 to 9 In other embodiments shown in FIG. 1 , the same or similar elements may be combined with Figure 1 The same reference numerals as described above are incremented by 100. Only the parts of these embodiments that differ from the previously described embodiments will be described.

[0128] exist Figure 2 In the embodiment shown, the structure takes the form of a membrane tank, for example the structure has a polyhedral shape.

[0129] The first sealing wall 103 of the structure 101 is a sealing film, such as a corrugated metal film or a metal film with continuous columnar sheets. The sealing film is supported by a plurality of support elements (not shown), such as support columns, which are positioned in the intermediate space 104 and extend between the second sealing wall 102 and the first sealing wall 103.

[0130] The metal film is made of, for example, Invar alloy that is, in other words, the metal film is made of an iron-nickel alloy having a coefficient of thermal expansion generally in the range of 1.2×10 -6 to 2×10 -6 K -1 .

[0131] According to one variant, the second wall 102 is a sealing film. In this case, the first sealing wall 103 is the primary sealing film, i.e., the first sealing wall 103 is for contacting the liquefied gas contained in the internal space 109, and the second wall is the secondary sealing film.

[0132] According to another variant, the structure includes a plurality of additional walls so as to form a multi-layer structure, such as a membrane tank incorporating one or more of the embodiments described above.

[0133] In a variant (not shown) and similar to Figure 2 , Figure 2 the intermediate space 104 includes a second porous separator and a second extraction region. The second porous separator is spaced apart from and fixed to the outer surface 131 of the first sealing wall 103. The second extraction region is located between the second porous separator and the outer surface 131 of the first sealing wall 103. The particulate region 114 is located between the porous separator 105 and the second porous separator. The second extraction region includes a second porous isolation layer held between the second porous separator and the outer surface 31 of the first sealing wall 3. The second porous separator has pores in a manner similar to the porous separator 105, and the size of the pores is smaller than the particle size of the particulate isolation packing.

[0134] According to another embodiment, Figure 3 the structure 201 shown in

[0135] According to this variant, the first sealing wall 203, the second sealing wall 202, and the internal space 209 extend along the longitudinal direction of the structure 201. The internal space 209 includes a through-opening that extends from the first longitudinal end of the structure 201 to the second longitudinal end of the structure 201 along the longitudinal direction of the structure 201. The through-opening allows the liquefied gas to be transported from the first longitudinal end of the structure 201 to the second longitudinal end of the structure 201, or the liquefied gas to be transported from the second longitudinal end of the structure 201 to the first longitudinal end of the structure 201.

[0136] The intermediate space 214 of the structure 201 further includes a second porous separator 215. The second porous separator 215 is spaced apart from and fixed to the outer surface 231 of the first sealing wall 203. The second extraction region 207 is located between the second porous separator 215 and the outer surface 231 of the first sealing wall 203.

[0137] The particle region 214 is located between the first porous separator 205 and the second porous separator 215.

[0138] In a manner similar to that previously described, the second extraction region 207 includes a second porous isolation layer held between the second porous separator 215 and the outer surface 231 of the first sealing wall 203, and the pore size of the second porous separator 215 is smaller than the particle size of the granular isolation filling.

[0139] In a variant (not shown and similar to Figure 3 ), the structure 201 includes a single porous separator, namely the porous separator 205, which is fixed to the second sealing wall 202.

[0140] The following uses Figures 5 to 9 to describe various embodiments of the porous separator 5.

[0141] As Figure 5 and Figure 6 shown, the porous separator 5 includes a rigid mesh member having a central portion 51 and at least two side portions 52. The central portion 51 is positioned to be spaced apart from and parallel to the second sealing wall 2. The at least two side portions 52 project perpendicularly from the central portion 51 towards the second sealing wall 2, and the side portions 52 have ends that abut against the second sealing wall 2. The porous separator 5 is fixed to the second sealing wall 2 via fastening means 53, for example, fixed to the second sealing wall 2 via bolts or rivets.

[0142] When a plurality of small-sized mesh members are juxtaposed side by side, as Figure 6 shown, one central fastener for each mesh member is sufficient.

[0143] The spacing between each of the mesh members has a size for preventing the passage of particulate thermal insulation filler.

[0144] According to Figure 7 and Figure 8 the variant of the porous separator 5 shown in, the porous separator 5 does not have side portions that rest against the second sealing wall 2 as is the case in Figure 5 In the present embodiment, the porous separator 5 is fixed to the second sealing wall 2 via support fastening means 153, which are positioned, for example, at the four corners of each mesh member. Each fastening means 153 includes, for example, an anchoring rod secured to the second sealing wall 2 and two fastening washers that sandwich the porous separator 5, so as to both secure the mesh member and hold the mesh member spaced apart from the second sealing wall 2.

[0145] According to Figure 9 the variant embodiment shown in, the porous separator 5 includes a fabric 54 that covers and is fixed to the mesh members. The fixing of the fabric to the mesh members is achieved, for example, by means of adhesive strips positioned between the mesh members and the fabric. When a plurality of fabrics 54 are used, these fabrics are secured to one another, for example, by stitching.

[0146] A method for evacuating an intermediate space of a structure according to one embodiment will be described below with reference to Figure 2 The management of the gas phase in the intermediate space 104 is carried out via a gas management system 110.

[0147] The management of the gas phase in the intermediate space 104 is carried out via a gas management system 110.

[0148] The gas management system 110 includes a suction line 42 that is connected to a vacuum pump 43 and leads outwards to an extraction area 107. Pressure sensors (not shown) are arranged in the extraction area 107 and the particulate area 114.

[0149] Before cooling and filling the interior space with liquefied gas, in order to evacuate the intermediate space 104, the vacuum pump is started until the gas phase in the intermediate space 104 reaches an absolute pressure of less than 300 Pa, and preferably, the vacuum pump is started until the gas phase in the intermediate space 104 reaches an absolute pressure of less than 100 Pa.

[0150] In order to manage the gas phase present in the intermediate space 104, the gas management system 110 may also include a supply line 40 that is connected to a gas source 41 and a compressor 50 and leads outwards to the extraction area 107. Such a gas management system can be used for monitoring the intermediate space 104 or for purging the internal gas of the intermediate space 104.

[0151] As Figure 2As shown, the gas management system 110 may also include various components for controlling and monitoring the injection and / or suction of gas.

[0152] For example, the gas management system 110 includes one or more devices selected from the following:

[0153] - a gas analyzer 44 for the gas extracted via the suction line 42,

[0154] - an outlet gas flow meter 45, an inlet gas flow meter 46,

[0155] - a control unit 47,

[0156] - a temperature sensor 49 located in the intermediate region 104.

[0157] In a variant of the method not shown, the gas management system 110 also includes a second suction line (not shown) that is connected to the vacuum pump 43 or another vacuum pump and leads outwards to a second extraction region as described above. For example, in the case of applying such a method to Figure 3 the second embodiment shown, the second suction line leads outwards to the second extraction region 207.

[0158] This configuration of applying suction to both the first extraction region and the second extraction region has the advantage of further accelerating the evacuation of the intermediate space, more specifically the evacuation of the particulate region 214, which is filled with particulate thermal insulation filler and thus the evacuation can be difficult and time-consuming.

[0159] Similarly, to manage the gas phase present in the intermediate space 104, the gas phase management system 110 may also include a supply line 40 that is connected to a gas source 41 and a compressor 50 and leads outwards to a second extraction region, such as Figure 3 the second extraction region 207 in the embodiment shown.

[0160] The different variants of this method can be adjusted and applied in a manner similar to the embodiments described previously.

[0161] Referring to Figure 4 , a cross-sectional view of the hydrogen carrier 70 shows a generally prismatic-shaped, sealed and insulated structure 71 installed within the double hull 72 of the ship. The walls of the structure 71 include: a primary sealing barrier for contacting the liquid hydrogen (LH2) contained in the structure; a secondary sealing barrier arranged between the primary sealing barrier and the double hull 72 of the ship; and two insulating barriers arranged between the primary sealing barrier and the secondary sealing barrier and between the secondary sealing barrier and the double hull 72, respectively.

[0162] As is well known, the loading / unloading pipe 73 arranged on the upper deck of the ship can be connected to a seaport or a port terminal through appropriate connectors so as to transfer the hydrogen load to or from the structure 71.

[0163] Figure 4 An example of a seaport terminal is shown, which includes a loading and unloading station 75, a submarine pipeline 76, and an onshore facility 77. The loading and unloading station 75 is a fixed offshore facility, including a movable arm 74 and a tower 78 for supporting the movable arm 74. The movable arm 74 carries a bundle of insulated flexible pipes 79, and the insulated flexible pipes 79 can be connected to the loading / unloading pipe 73. The adjustable movable arm 74 can be adapted to any configuration of the hydrogen carrier ship. A connecting conduit (not shown) extends within the tower 78. The loading and unloading station 75 enables the loading of the hydrogen carrier ship 70 from the onshore facility 77 and the unloading of the hydrogen carrier ship 70 to the onshore facility 77. The onshore facility 77 includes a tank 80 for storing liquefied gas and a connecting pipe 81 connected to the loading / unloading station 75 via the submarine pipeline 76. The submarine pipeline 76 allows for the long-distance transfer of liquefied gas between the loading / unloading station 75 and the onshore facility 77, and the long distance is, for example, 5 km, thereby allowing the hydrogen carrier ship 70 to stay away from the coast during the loading and unloading operations.

[0164] To generate the pressure required for transferring the liquefied gas, it is necessary to operate the pump installed on the carrier ship 70 and / or the pump installed in the onshore facility 77 and / or the pump installed at the loading and unloading station 75.

[0165] Although the present invention has been described in connection with multiple specific embodiments, it is obvious that the present invention is not limited to these embodiments, and the present invention includes all technical equivalents of the described means falling within the scope of the present invention, as well as any combination thereof. For example, the first sealing wall and the second sealing wall can be interchanged.

[0166] The use of the verb “comprise”, “include” or “contain” and their conjugate forms does not exclude the presence of elements or steps other than those recited in the claims.

[0167] In the claims, any reference signs placed in parentheses shall not be construed as limiting the scope of the claims.

Claims

1. A sealed and thermally insulated structure for the storage or transportation of liquefied gases, said liquefied gases being selected from: liquefied natural gas, helium, oxygen, argon, and hydrogen, said structure (1, 101, 201) comprising: A first sealing wall (3, 103, 203) and a second sealing wall (2, 102, 202), said second sealing wall (2, 102, 202) being positioned to be spaced apart from said first sealing wall (3, 103, 203), A thermally insulated intermediate space (4, 104, 204), said intermediate space (4, 104, 204) being provided between said first sealing wall (3, 103, 203) and said second sealing wall (2, 102, 202), said intermediate space (4, 104, 204) being adapted and configured to be set to a vacuum, Wherein, said intermediate space (4, 104, 204) comprises: A first porous separator (5, 105, 205); A first extraction region (7, 107, 207), said first extraction region (7, 107, 207) being located between said first porous separator (5, 105, 205) and said second sealing wall (2, 102, 202), A particulate region (4, 114, 214), said particulate region (4, 114, 214) being located between said first porous separator (5, 105, 205) and said first sealing wall (3, 103, 203), said particulate region (14, 114, 214) being filled with particulate thermal insulation filler, Wherein, said first porous separator (5, 105, 205) has pores with a size smaller than the particle size of said particulate insulation filler to retain said particulate thermal insulation filler within said particulate region (14, 114, 214), wherein, said first extraction region (7, 107, 207) has a resistance to the passage of gas molecules, said resistance being less than the resistance of the passage of said gas molecules through said particulate region (14, 114, 214), wherein said first extraction region (7, 107, 207) comprises a first porous insulation layer, And wherein, said first porous insulation layer has interconnected open pores, the interconnected open pores of said first porous insulation layer having a size larger than the open pore size of said particulate thermal insulation filler, and said first porous insulation layer having a porosity greater than the porosity of said particulate thermal insulation filler, Wherein, said first porous separator (5, 105, 205) comprises a rigid mesh member fixed to one of said first sealing wall and said second sealing wall.

2. The structure according to claim 1, wherein, Said intermediate space (204) comprises a second porous separator (215) spaced apart from said first sealing wall (203) and a second extraction region (207) located between said second porous separator (215) and said first sealing wall (203), said particulate region (214) being located between said first porous separator (205) and said second porous separator (215), Wherein, the second porous separator (215) has pores with a size smaller than the particle size of the granular insulating filler, and wherein the second extraction region (207) has a lower resistance to the passage of gas molecules than the resistance of the gas molecules passing through the granular regions (14, 114, 214).

3. The structure according to claim 2, wherein, The second extraction region includes a second porous insulating layer, and wherein, the second porous insulating layer has interconnected open pores, the interconnected open pores of the second porous insulating layer have a size larger than the size of the open pores of the granular thermal insulating filler, and the second porous insulating layer has a porosity larger than the porosity of the granular thermal insulating filler.

4. The structure according to claim 1, wherein, The first porous separator (5, 105, 205) includes a fabric that covers and is attached to the mesh, and the fabric has pores with a size smaller than the particle size of the granular insulating filler.

5. The structure according to any one of claims 1 to 4, wherein, The granular thermal insulating filler has a particle size smaller than 4000 μm, and preferably, the granular thermal insulating filler has a particle size smaller than 2000 μm.

6. The structure according to any one of claims 1 to 5, the structure including a vacuum pump (43) connected to the first extraction region (7, 107, 207).

7. The structure according to any one of claims 1 to 6, wherein, The intermediate space has a gas phase with an absolute pressure less than 300 Pa.

8. The structure according to any one of claims 1 to 7, wherein, The granular insulating filler is selected from: perlite, hollow glass microspheres, fumed silica, and silica aerogel.

9. The structure according to any one of claims 1 to 8, wherein, The first porous insulating layer includes glass wool.

10. The structure according to any one of claims 1 to 9, wherein, The first porous separator (5, 105, 205) is selected from: a sheet, the sheet being perforated through the thickness of the sheet; an expanded metal sheet; a metal mesh; a composite material board, the composite material board being perforated through the thickness of the composite material board; a composite material board made of fibers bonded together, and the composite material board having an open porosity greater than 30% of the volume of the composite material board.

11. The structure according to any one of claims 1 to 10, wherein, The first sealing wall (3, 103, 203) is for contacting the liquefied gas, and the second sealing wall (2, 102, 202) is disposed outside the first sealing wall (3, 103, 203).

12. The structure according to any one of claims 1 to 11, the structure being in the form of a tank for storing liquefied gas.

13. The structure according to any one of claims 1 to 12, the structure being in the form of a pipeline for transporting liquefied gas.

14. A method for evacuating a sealed and thermally insulated structure for storing or transporting liquefied gas, the method comprising: - providing the structure according to any one of claims 1 to 13, and - Before cooling and filling the interior space of the sealing structure with the liquefied gas, the pressure in the intermediate space (14, 114, 214) is reduced via a vacuum pump (43) connected to the first extraction area (7, 107, 207) until the gas phase in the intermediate space (4, 104, 204) reaches an absolute pressure of less than 200 Pa, preferably until the gas phase in the intermediate space (4, 104, 204) reaches an absolute pressure of less than 100 Pa.

15. A ship (70) for transporting liquefied gas, the ship (70) comprising a structure (71) according to any one of claims 1 to 13.

16. A transfer system for transferring liquefied gas, the system comprising: The ship (70) according to claim 15; insulating pipes (73, 79, 76, 81) arranged to connect the structure (71) installed in the hull of the ship to a floating or land-based storage facility (77); and a pump configured to drive liquefied gas from the floating or land-based storage facility through the insulating pipes to the structure of the ship or to drive liquefied gas from the structure of the ship through the insulating pipes to the floating or land-based storage facility.

17. A method for loading or unloading a ship (70) according to claim 15, wherein, Transporting liquefied gas from a floating or land-based storage facility (77) to the structure (71) of the ship (70) through the insulating pipes (73, 79, 76, 81), or transporting liquefied gas from the structure (71) of the ship (70) to a floating or land-based storage facility (77) through the insulating pipes (73, 79, 76, 81).

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