Gas-filled container

Abstract

To achieve a reduction in manufacturing costs without increasing the thickness of container walls.SOLUTION: A hydrogen-filled container 10 includes a cylindrical outer container 11 and an inner container 12 disposed inside the outer container 11. The outer container 11 includes an outer container body 11a and a clay mineral film 11b containing montmorillonite formed on the inner surface of the outer container body 11a. The longitudinal elastic modulus multiplied by the thickness of the outer container 11 is greater than that of the inner container 12.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to gas-filled vessels. [Background technology]

[0002] 2. Description of the Related Art Gas-filling containers for filling with gas, for example, high-pressure hydrogen gas, are conventionally known.

[0003] However, when a metal gas-filled container is used, hydrogen can cause metal corrosion, and for this reason, it has been considered to make the gas-filled container out of a synthetic resin such as nylon.

[0004] However, synthetic resin gas-filled containers have a problem with gas barrier properties, and in order to improve the gas barrier properties, it is necessary to increase the thickness of the container, which increases the manufacturing cost and the weight of the container. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2017-207094 A Summary of the Invention [Problem to be solved by the invention]

[0006] The present disclosure has been made in consideration of these points, and has an object to provide a gas-filled container that can reduce the weight of the container and keep manufacturing costs low. [Means for solving the problem]

[0007] The present disclosure relates to a first gas-filled container comprising a cylindrical outer container made of synthetic resin, and a cylindrical inner container made of synthetic resin that is placed within the outer container and forms a filled space between the outer container and the inner container into which a first gas to be supplied to a consumer is filled, and the inner container is filled with a second gas that absorbs pressure fluctuations in the filled space, wherein the outer container has an outer container body and a clay mineral film formed on the inner surface of the outer container body, and when internal pressure is applied to the outer container, the longitudinal elastic modulus x thickness of the outer container body of the outer container is greater than the longitudinal elastic modulus x thickness of the inner container.

[0008] The present disclosure is a gas-filled container, wherein the first gas and the second gas have the same gas composition.

[0009] The present disclosure relates to a gas-filled container, wherein the outer container body has a cylindrical body portion and a pair of end plates provided on both ends of the body portion.

[0010] The present disclosure is a gas-filled container having a first mounting portion that penetrates one of the pair of end plates, the inner container being connected to the inside of the first mounting portion, and a pressure regulating valve that controls the pressure of hydrogen in the inner container being connected to the outside of the first mounting portion.

[0011] The present disclosure is a gas-filled container, in which a second mounting portion is provided penetrating the other of the pair of end plates, and an on-off valve is connected to the outside of the second mounting portion.

[0012] The present disclosure is a gas-filled container, in which an inner side of the second attachment part is fixed to the inner container and holds the inner container.

[0013] The present disclosure relates to a gas-filled container, wherein an inner side of the second attachment portion is spaced apart from the inner container.

[0014] The present disclosure is a gas-filled container, wherein the outer container body of the outer container is made of polycarbonate resin or acrylic resin, and the inner container is made of polyurethane resin.

[0015] The present disclosure is a gas-filled container having reinforced plastic fiber wound around the outer periphery of the outer container.

[0016] Disclosed is a gas-filled vessel, wherein the clay mineral film comprises montmorillonite.

[0017] The present disclosure is a gas-filled container, wherein the ratio of the internal volume of the outer container to the internal volume of the inner container is 2:1 to 10:1. Effect of the Invention

[0018] According to the present disclosure, it is possible to fill the container with high-pressure gas without making the container thick, thereby making the container lighter overall. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a cross-sectional view showing a hydrogen filling container according to a first embodiment. [Diagram 2] FIG. 2 is an enlarged view showing the first mounting portion of the hydrogen filling container. [Diagram 3] FIG. 3 is an enlarged view showing the second mounting portion of the hydrogen filling container. [Figure 4] FIG. 4 is a cross-sectional view showing a hydrogen filling container according to the second embodiment. [Diagram 5] FIG. 5 is an enlarged view showing the second mounting portion of the hydrogen filling container. [Figure 6] FIG. 6 is a cross-sectional view showing the outer container of a hydrogen-filled container. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] <First embodiment> Hereinafter, a first embodiment of the present disclosure will be described with reference to the drawings.

[0021] 1 to 3 and 6 are diagrams showing a first embodiment of the present disclosure.

[0022] In this embodiment, a hydrogen-filled container that is filled with high-pressure hydrogen gas will be described as an example of a gas-filled container that is filled with gas. However, the gas-filled container may be filled with high-pressure nitrogen gas or high-pressure carbon dioxide gas in addition to high-pressure hydrogen gas. The hydrogen-filled container may be filled with high-pressure gaseous hydrogen gas or liquid hydrogen gas. Hereinafter, in this embodiment, a hydrogen-filled container that is filled with high-pressure gaseous hydrogen gas will be described. As shown in FIG. 1 to FIG. 3, the hydrogen-filled container 10 includes an outer container 11 made of synthetic resin, for example, polycarbonate (PC) or acrylic polymethyl methacrylate (PMMA), and an inner container 12 made of synthetic resin, for example, polyurethane (PU), that is disposed in the outer container 11 and forms a filling space 15 between the outer container 11 and hydrogen is filled.

[0023] As shown in FIG. 6, the outer container 11 has an outer container body 11a made of polycarbonate (PC) or acrylic polymethyl methacrylate (PMMA), a clay mineral film 11b containing at least a gas barrier component such as montmorillonite provided on the inner surface of the outer container body 11a, and a reinforced plastic fiber 11c wrapped around the outer surface of the outer container body 11a.

[0024] The outer container body 11a of the outer container 11 is a basic component of the outer container 11, and contains hydrogen gas (hereinafter also referred to as hydrogen) to be filled into the filling space 15. As will be described later, hydrogen is filled into the filling space 15 with a pressure of, for example, 40 MPa to 100 MPa, preferably 40 MPa to 50 MPa, so that the outer container body 11a of the outer container 11 has a desired modulus of longitudinal elasticity and a desired thickness so as to be able to contain such high-pressure hydrogen.

[0025] The characteristics of the outer container body 11a will be described later.

[0026] Furthermore, the clay mineral film 11b containing montmorillonite is made of a material having high hydrogen barrier properties, and can maintain the high hydrogen barrier properties regardless of temperature.

[0027] The structure of the clay mineral film 11b containing montmorillonite will be described later.

[0028] The reinforced plastic fiber 11c is made of reinforced plastic fibers such as carbon fiber, and is wound around the outer surface of the outer container body 11a to protect and strengthen the outer container body 11a from the outside.

[0029] Furthermore, the inner container 12 is made of polyurethane (PU) and has the desired longitudinal elastic modulus and thickness, and when high-pressure hydrogen is filled into the filling space 15, it compresses and deforms inwardly, thereby preventing the outer container 11 from expanding and deforming outwardly.

[0030] That is, the clay mineral film 11b containing montmorillonite of the outer container 11 is formed into a clay-like form, and then coated on the inner surface of the outer container body 11a and dried, and is a material with low elasticity. Therefore, when high-pressure hydrogen is filled into the filling space 15, the inner container 12 is compressed and deformed inwardly, which suppresses the outward expansion and deformation of the outer container 11, thereby preventing the clay mineral film 11b containing montmorillonite from falling off from the inner surface of the outer container body 11a.

[0031] In this embodiment, hydrogen (also referred to as a first gas) of, for example, 40 MPa to 100 MPa is filled into the filling space 15 between the outer container 11 and the inner container 12, and hydrogen (also referred to as a second gas) of, for example, 0.1 MPa to 0.15 MPa for adjusting the pressure is filled into the inner container 12. The first gas in the filling space 15 and the second gas in the inner container 12 contain the same gas component (hydrogen). Note that the first gas in the filling space 15 and the second gas in the inner container 12 do not necessarily need to contain completely the same gas component.

[0032] In this case, an internal pressure of 40 MPa to 100 MPa, which is the combination of the hydrogen filled in the filling space 15 and the outside atmosphere, is applied to the inner surface of the outer container 11. In addition, an external pressure approximately equal to the internal pressure on the inner surface of the outer container 11 is applied to the outer surface of the inner container 12, which is the combination of the hydrogen filled in the filling space 15 and the hydrogen for adjusting the pressure in the inner container 12.

[0033] In this case, the amount of radial expansion of the outer container 11 outward is calculated by the following formula. The radial expansion of the outer container B1 = (R1 2 ×P1) / (t1×E1) (1)

[0034] Here, assuming that the deformation of the outer container 11 is determined by the outer container body 11a, t1 is the thickness of the outer container body 11a, E1 is the modulus of longitudinal elasticity (Young's modulus) of the outer container body 11a, P1 is the internal pressure applied to the inner surface of the outer container 11, and R1 is the radius of the outer container body 11a.

[0035] On the other hand, the amount of compression of the inner container 12 in the inward radial direction is calculated by the following formula. Amount of radial compression of the inner container B2 = (R2 2 ×P2) / (t2×E2) (2)

[0036] Here, t2 is the thickness of the inner container, E2 is the modulus of longitudinal elasticity (Young's modulus) of the inner container 12, P2 is the external pressure applied to the outer surface of the inner container, and R2 is the radius of the inner container 12.

[0037] In this embodiment, when high-pressure hydrogen is filled into the filling space 15 as described above, the amount of radial outward expansion of the outer container 11 and the amount of radial inward compression of the inner container 12 are calculated using equations (1) and (2).

[0038] As described below, it is considered that the internal pressure P1 applied to the inner surface of the outer container 11 and the external pressure P2 applied to the outer surface of the inner container 12 are substantially equal. If the outer container 11 and the inner container 12 are manufactured from the same material, with the same radius and thickness, the amount of radial expansion of the outer container and the amount of radial compression of the inner container will be the same.

[0039] From the above, by making (modulus of elasticity E1 of outer container body 11a of outer container 11 × thickness t1 of outer container body 11a of outer container 11) > (modulus of elasticity E2 of inner container 12 × thickness t2 of inner container), the inner container 12 becomes more likely to undergo compressive deformation in the radially inward direction compared to the outer container 11 which undergoes expansion deformation in the radially outward direction.

[0040] In this embodiment, (modulus of longitudinal elasticity E1 of outer container body 11a of outer container 11 × thickness t1 of outer container body 11a of outer container 11) > (modulus of longitudinal elasticity E2 of inner container 12 × thickness t2 of inner container). For this reason, when high-pressure hydrogen is filled into filling space 15 of hydrogen filling container 10, inner container 12 is compressed inward and significantly deformed. As a result, pressure fluctuations within filling space 15 when filling space 15 with high-pressure hydrogen can be absorbed by radially inward compressive deformation of inner container 12. This suppresses outward expansion and deformation of outer container 11, and prevents clay mineral film 11b containing montmorillonite from falling off from the inner surface of outer container body 11a.

[0041] Next, the structure for supplying hydrogen to the filling space 15 between the outer container 11 and the inner container 12 and into the inner container 12 will be described with reference to Figs.

[0042] The outer container body 11a of the outer container 11 has a cylindrical body 15A and a pair of end plates 16, 17 provided at both ends of the body 15A. A first attachment portion 20 is provided penetrating one end plate 16, and a second attachment portion 30 is provided penetrating the other end plate 17.

[0043] 2, the first mounting part 20 has a mouth part 21 that penetrates one of the end plates 16 and a flange 22 attached to the mouth part 21. The upper part 12b of the inner container 12 is bonded to the outer surface of the mouth part 21 of the first mounting part 20. In addition, the flange 22 of the first mounting part 20 is fixed to the inner surface of one of the end plates 16.

[0044] As a result, the first mounting portion 20 is fixed to one end plate 16 via the flange 22, and the upper portion 12b of the inner container 12 is fixed to the outer surface of the mouth portion 21 of the first mounting portion 20.

[0045] Further, a pressure regulating valve 25 for regulating the pressure of hydrogen filled in the inner container 12 is connected to the outside of the mouth 21 of the first mounting part 20. The hydrogen in the inner container 12 is adjusted to 0.1 MPa to 0.15 MPa by this pressure regulating valve 25.

[0046] 3, a second mounting portion 30 is provided penetrating the other end plate 17 of the outer vessel 11, and this second mounting portion 30 has a flange 31 fixed to the inner surface of the other end plate 17. A lid 32 penetrating the other end plate 17 is attached to this flange 31. An on-off valve 35 for supplying hydrogen into the outer vessel 11 is connected to the outside of the lid 32. In this manner, the pressure regulating valve 25 and the on-off valve 35 are disposed at a distance from each other at the upper and lower parts of the outer vessel 11. Therefore, the pressure regulating valve 25 and the on-off valve 35 can be handled independently of each other without interfering with each other.

[0047] High pressure hydrogen supplied from a hydrogen supply system (not shown) is sent to the space 32a between the lid 32 and the flange 31 via an on-off valve 35. Thereafter, high pressure hydrogen, for example 40 MPa to 100 MPa, is supplied from the space 32a between the lid 32 and the flange 31 through a supply hole 31a formed in the flange 31 into the filling space 15 between the outer container 11 and the inner container 12.

[0048] 3, a mounting ring 33 is provided on the upper part of the flange 31, and the bottom part 12a of the inner container 12 is fixed by bonding to the outer surface of this mounting ring 33. The bottom part 12a of the inner container 12 fixed by the mounting ring 33 is sealed by the flange 31.

[0049] In this specification, the terms "upper", "upper", "lower", "lower" and "bottom" refer to the upper, "upper", "lower", "lower" and "bottom" when the hydrogen filling container 10 is positioned in the direction shown in Figure 1.

[0050] Next, the materials constituting the outer container 11 and inner container 12 that constitute the hydrogen-filled container 10 will be described.

[0051] The outer container body 11a of the outer container 11 includes polycarbonate (PC) or acrylic polymethyl methacrylate (PMMA), of which the modulus of longitudinal elasticity (also called Young's modulus) of polycarbonate (PC) determined by a measurement method conforming to ASTM D638 is 2300 MPa, and the modulus of longitudinal elasticity of polymethyl methacrylate (PMMA) determined by a measurement direction conforming to ASTM D638 is 3430 MPa.

[0052] Moreover, the radius of the outer container body 11a before deformation is 100 mm to 750 mm, and the thickness is 10 mm to 100 mm.

[0053] On the other hand, the inner container 12 is made of, for example, polyurethane (PU), and the modulus of elasticity of polyurethane, as determined by a measurement method conforming to ASTM D638, is 70 MPa to 690 MPa.

[0054] The radius of the inner container 12 before deformation is 30 mm to 200 mm, and the thickness is 10 mm to 40 mm. The ratio of the internal volume of the outer container body 11a before deformation to the internal volume of the inner container 12 before deformation is 2:1 to 10:1. In this case, if the internal volume of the inner container 12 is larger than the above internal volume ratio, the storage space of the first gas stored in the outer container 11 (in the filling space 15) becomes smaller. On the other hand, if the internal volume of the inner container 12 is smaller than the above internal volume ratio, the effect of absorbing the pressure fluctuation in the filling space 15 by the deformation of the inner container 12 cannot be expected. In contrast, according to the present invention, the ratio of the internal volume of the outer container body 11a before deformation to the internal volume of the inner container 12 before deformation is 2:1 to 10:1. This makes it possible to reliably secure the storage space of the first gas stored in the outer container 11 (in the filling space 15), and to absorb the pressure fluctuation in the filling space 15 by the deformation of the inner container 12.

[0055] In this embodiment, the amount of radial expansion of the outer container 11 is calculated by formula (1), and the amount of radial compression of the inner container 12 is calculated by formula (2).

[0056] According to this embodiment, by making the Young's modulus E1 of the outer container body 11a of the outer container 11 × the thickness t1 of the outer container body 11a of the outer container > the Young's modulus E2 of the inner container 12 × the thickness t2 of the inner container, the inner container 12 is more likely to undergo compressive deformation in the radially inward direction than the outer container 11 which undergoes expansion deformation in the radially outward direction.

[0057] For this reason, when high-pressure hydrogen is filled into the filling space 15 of the hydrogen filling container 10, the inner container 12 is compressed inward and significantly deformed. As a result, the pressure fluctuations within the filling space 15 when the filling space 15 is filled with high-pressure hydrogen can be absorbed by the radially inward compressive deformation of the inner container 12. This suppresses the outward expansion and deformation of the outer container 11, and prevents the clay mineral film 11b containing montmorillonite from falling off from the inner surface of the outer container body 11a.

[0058] Next, the clay mineral film 11b containing montmorillonite of the outer container 11 will be described. The clay mineral film 11b is obtained by applying a coating liquid to the inner surface of the outer container body 11a and drying it. The clay mineral film 11b after drying has extremely fragile characteristics and may fall off from the outer container body 11a due to deformation of the outer container body 11a, but according to this embodiment, deformation of the outer container body 11a can be suppressed.

[0059] <Coating fluid> Next, the coating liquid for forming the clay mineral film 11b will be described.

[0060] The coating liquid contains a clay mineral, water, and butenediol vinyl alcohol copolymer (hereinafter also referred to as "BVOH"). The content of the clay mineral in the solid content of the coating liquid (components excluding the medium (solvent)) is 55 to 85 mass%, and the content of BVOH in the solid content is 15 to 45 mass%. The coating liquid is usually a dispersion in which clay is dispersed in water or an aqueous medium (a mixture of water and a water-soluble organic solvent) in which BVOH is dissolved.

[0061] When clay minerals are mixed with a medium such as water, the crystal layers separate and disperse in the medium. When BVOH is added, the BVOH dissolves in the medium, and a uniform mixture (slurry, coating liquid) of clay minerals and BVOH can be obtained. When this slurry is applied to the outer container body 11a and the coating is dried, a clay mineral film 11b is obtained in which the clay minerals and BVOH are composited (integrated) at the nano level.

[0062] Each component constituting the coating solution of the present invention will be described below.

[0063] <Clay minerals> The coating liquid of the present invention contains a specific amount of clay mineral. The clay mineral is composed of a layered silicate compound, and the gas barrier property is not easily deteriorated even at high temperatures. In addition, the crystal layer of the clay mineral basically does not allow gas to pass through, and has excellent barrier properties against hydrogen gas and helium gas, which have small molecular sizes.

[0064] The clay mineral may be natural or synthetic. The clay mineral used in the present invention preferably contains at least montmorillonite, and also contains mica, vermiculite, beidellite, saponite, hectorite, stevensite, magadiite, ilerite, and kanemite. The clay mineral preferably contains montmorillonite and others in an amount of 80% by mass or more, more preferably 90% by mass or more. The clay mineral more preferably contains at least montmorillonite, and also contains at least one of mica, vermiculite, beidellite, saponite, hectorite, stevensite, magadiite, ilerite, and kanemite.

[0065] The clay mineral contains at least montmorillonite, and preferably contains at least one of mica, beidellite, saponite, and hectorite.

[0066] From the viewpoint of dispersibility in a medium such as water and applicability of a coating liquid, the clay mineral is preferably one or more selected from Na-type clay, Li-type clay, K-type clay, and NH4-type clay, more preferably Na-type clay or Li-type clay. In addition, for example, in consideration of further improving the water resistance of a clay film formed using a slurry, one or more polyvalent cation clays selected from Mg-type clay, Ca-type clay, Al-type clay, and Cu-type clay can also be used.

[0067] Here, Na-type, Li-type, K-type, NH4-type, Mg-type, Ca-type, Al-type, and Cu-type clays refer to clays in which the amounts of Na+, Li+, K+, NH4+, Mg2+, Ca2+, Al3+, and Cu2+ (units: meq / 100 g) of the leached cations of the clay (i.e., the total amount of leached cations, unit: meq / 100 g) are 70% or more.

[0068] In this specification, the amount of leached cations in clay is calculated by leaching the interlayer cations of clay using 100 mL of 1 M ammonium acetate aqueous solution (1 M sulfuric acid for Al-type clay, 10 mass % potassium chloride aqueous solution for NH4-type clay) per 0.5 g of clay for 4 hours, and measuring the concentrations of various cations in the obtained solution using ICP emission spectrometry, atomic absorption spectrometry, an ammonia electrode, etc.

[0069] The content of the clay in the solid content of the coating liquid is 55 to 85 mass%, preferably 57 to 83 mass%, more preferably 58 to 82 mass%, and even more preferably 59 to 81 mass%. The content is also preferably 65 mass% or more, and also preferably 70 mass% or more.

[0070] Clay minerals are also readily available on the market.

[0071] <Butenediol vinyl alcohol copolymer (BVOH)> The coating liquid contains a specific amount of BVOH. By containing a specific amount of BVOH, the gas barrier properties of the clay film can be fully exhibited while effectively increasing the water resistance of the clay mineral film 11b. In other words, since BVOH is water-soluble, it can form a uniform mixture with the clay mineral at the nano level, and in the resulting film, it functions as a binder that completely fills the voids in the clay particles, forming a clay mineral film 11b in which the clay mineral and BVOH are composited (integrated) at the nano level. The clay mineral film 11b formed in this way exhibits high gas barrier properties. One of the reasons for this is thought to be the formation of strong hydrogen bonds between the clay crystals and BVOH.

[0072] BVOH can be obtained by hydrolyzing a copolymer obtained by the reaction of 3,4-diacetoxy-1-butene and vinyl acetate. BVOH may be a random copolymer or a block copolymer. The copolymerization ratio of 3,4-diacetoxy-1-butene and vinyl acetate used as raw monomers of BVOH is not particularly limited. For example, it can be [3,4-diacetoxy-1-butene]:[vinyl acetate]=1:99 to 99:1 (molar ratio), and it is also preferable to set [3,4-diacetoxy-1-butene]:[vinyl acetate]=10:90 to 90:10 (molar ratio), and it is also preferable to set [3,4-diacetoxy-1-butene]:[vinyl acetate]=20:80 to 80:20 (molar ratio).

[0073] The polymerization degree of BVOH is not particularly limited. For example, it can be 100 to 10,000, preferably 200 to 5,000, and more preferably 250 to 3,000. The smaller the polymerization degree of BVOH, the lower the viscosity of the dispersion liquid, which is preferable from the viewpoint of handling.

[0074] The saponification degree of BVOH is preferably 70 mol % or more, more preferably 80 mol % or more, and even more preferably 90 mol % or more. The higher the saponification degree, the higher the water resistance of the resulting composite clay film tends to be.

[0075] BVOH can be obtained from the market, and a preferred example is G-polymer (manufactured by Mitsubishi Chemical Corporation, saponification degree 95.0 mol % or more). BVOH can also be obtained by addition polymerization of monomers by a conventional method.

[0076] The content of the butenediol-vinyl alcohol copolymer in the solid content of the coating liquid is 15 to 45 mass%, preferably 17 to 43 mass%, more preferably 18 to 42 mass%, and even more preferably 19 to 41 mass%. The content is also preferably 35 mass% or less, and also preferably 30 mass% or less.

[0077] <Other ingredients> The coating fluid of the present invention may contain a silane coupling agent, a crosslinking agent, an organic polymer other than BVOH, silica, a surfactant, inorganic nanoparticles, etc. The total content of these components is usually 10 mass % or less of the solid content of the coating fluid.

[0078] The method for applying the coating liquid is not particularly limited, and examples thereof include spraying, spin coating, dipping, roll coating, blade coating, doctor roll, doctor blade, curtain coating, slit coating, screen printing, inkjet, and dispensing.

[0079] The drying temperature for the coating film is not particularly limited and can be, for example, 70 to 120° C. The drying time can be any time that the coating film can be sufficiently dried, and can be, for example, 1 minute to 24 hours, preferably 15 minutes to 12 hours, and preferably 20 minutes to 3 hours.

[0080] In addition, after drying the coating film, it can be subjected to a heat treatment at, for example, 130°C or higher (preferably 140°C or higher, more preferably 150°C or higher) within the range of the heat resistance temperature of the supporting substrate. The heat treatment time is preferably 1 minute to 24 hours, more preferably 15 minutes to 12 hours, and more preferably 20 minutes to 3 hours. Although a composite clay film exhibiting sufficiently high water resistance and gas barrier properties can be obtained without this heat treatment, the solvent can be completely removed by heat treatment, and a more densified composite clay film with higher water resistance and higher gas barrier properties can be obtained. That is, it is also a preferred embodiment that the composite clay film of the present invention is a product heat-treated at 130°C or higher. The degree of densification by heat treatment can be understood to some extent by measuring the density of the composite clay film and shifting the value of the 001 peak of X-ray diffraction to a high angle, but it is difficult to specifically and accurately specify the structure of the composite clay film, and in the present invention, the state of the clay composite film may be specified by its heat treatment temperature as described above. The heat treatment temperature is usually 200°C or lower.

[0081] Next, the operation of this embodiment having the above configuration will be described.

[0082] First, as shown in FIG. 1, hydrogen (second gas) is supplied from a hydrogen supply system (not shown) through a pressure regulating valve 25 into the inner container 12 of the hydrogen-filled container 10, and the hydrogen in the inner container 12 is adjusted to, for example, 0.15 MPa.

[0083] In this case, the internal pressure of the inner container 12 becomes higher than the atmospheric pressure (0.1 MPa) inside the outer container 11. Since the inner container 12 is made of polyurethane (PU), which is easily deformed, the inner container 12 placed inside the outer container 11 expands slightly radially outward within the outer container 11 (solid line in FIG. 1).

[0084] Thereafter, hydrogen (second gas) at high pressure, for example, 40 MPa to 100 MPa, is supplied into the filling space 15 between the outer container 11 and the inner container 12 from a hydrogen supply system (not shown) via an on-off valve .

[0085] In this case, hydrogen supplied through the on-off valve 35 first enters the space 32a between the flange 31 and the lid 32, and is then supplied from this space 32a into the filling space 15 between the outer container 11 and the inner container 12 through a supply hole 31a formed in the flange 31. At this time, hydrogen at a high pressure of, for example, 40 MPa to 100 MPa is supplied into the filling space 15.

[0086] At this time, as a result of combining the hydrogen filled in the filling space 15 with the outside atmosphere, an internal pressure of 40 MPa to 100 MPa is applied to the inner surface of the outer container 11. Furthermore, as a result of combining the hydrogen filled in the filling space 15 with the hydrogen for adjusting the pressure in the inner container 12, an external pressure of 40 MPa to 100 MPa is applied to the outer surface of the inner container 12. At this time, the atmospheric pressure applied to the outer container 11 is 0.1 MPa, and the inner container 12 is filled with hydrogen at a pressure slightly higher than atmospheric pressure (0.15 MPa). However, since this atmospheric pressure and the pressure inside the inner container 12 are considerably lower than the hydrogen pressure in the filling space 15 (40 to 100 MPa), the external pressure applied to the outer surface of the inner container 12 can be considered to be approximately the same pressure as the internal pressure applied to the inner surface of the outer container 11.

[0087] In this embodiment, if (modulus of elasticity E1 of outer container body 11a of outer container 11 × thickness t1 of outer container body 11a of outer container 11) is A1 and (modulus of elasticity E2 of inner container 12 × thickness t2 of inner container 12) is A2, and if polycarbonate with a modulus of elasticity of 2300 MPa is used for outer container body 11a and the thickness of outer container body 11a is 55 mm, A1 = 126,500 MPa mm. Also, if polyurethane with a modulus of elasticity of 380 MPa is used for inner container 12 and the thickness of inner container 12 is 25 mm, A2 = 9,500 MPa mm. In other words, A1 > A2. The relationship between A1 and A2 is preferably A1=(5-30)×A2. By making A1 considerably larger than A2, the structure of the outer container 11 and the inner container 12 is such that, when hydrogen is filled into the filling space 15, the outer container 11 expands radially outward, while the inner container 12 is easily compressed radially inward. If A1 is less than A2×5, it is difficult to obtain the effect that the inner container 12 is easily compressed radially inward, while the outer container 11 is easily expanded radially outward. On the other hand, if A1 is A2×30 or more, it is possible to obtain the effect that the inner container 12 is easily compressed radially inward, while the outer container 11 is easily expanded radially outward, but it is necessary to make the thickness of the outer container body 11a of the outer container 11 excessively thick, making it difficult to reduce the weight of the outer container 11. In this embodiment, the modulus of longitudinal elasticity of the outer container body 11a (for example, 2300 MPa in the case of polycarbonate) is also greater than the modulus of longitudinal elasticity of the inner container 12 (for example, 380 MPa in the case of urethane).

[0088] When high-pressure hydrogen is filled into the filling space 15 of the hydrogen filling container 10, pressure fluctuations occur within the filling space 15, but in this case, the inner container 12, which is easily deformed and is filled with hydrogen (second gas), can be significantly compressed and deformed radially inward. This makes it possible to suppress outward expansion and deformation of the outer container 11, which is less likely to deform, and prevent the clay mineral film 11b containing montmorillonite from falling off.

[0089] Furthermore, when a consumer uses the hydrogen in the hydrogen-filled container 10, hydrogen (first gas) is gradually released from the filling space 15 of the hydrogen-filled container 10 via the on-off valve 35. In this case, pressure fluctuations also occur in the filling space 15, but in this case too, the inner container 12 can be largely expanded and deformed radially outward. This makes it possible to suppress inward compressive deformation of the outer container 11 and prevent the clay mineral film 11b containing montmorillonite from falling off. From the above, the hydrogen (first gas) in the outer container 11 (in the filling space 15) becomes the gas supplied to the consumer, and the hydrogen (second gas) in the inner container 12 becomes the gas that absorbs the pressure fluctuations in the outer container 11 (in the filling space 15).

[0090] As described above, according to this embodiment, outer container 11 has clay mineral film 11b containing at least montmorillonite provided on the inner surface of outer container body 11a, and therefore outer container 11 has high hydrogen barrier properties. Therefore, there is no need to make outer container 11 thicker than necessary in order to improve the hydrogen barrier properties, which allows the weight of the entire hydrogen-filled container 10 to be reduced and manufacturing costs to be reduced.

[0091] Furthermore, when filling the filling space 15 of the hydrogen filling container 10 with high-pressure hydrogen, the inner container 12 can be compressed and deformed in a radially inward direction to a greater extent than the outer container 11, which expands and deforms in a radially outward direction. Furthermore, when the high-pressure hydrogen in the filling space 15 is discharged to the outside, the inner container 12 can be expanded and deformed in a radially outward direction to a greater extent. In either case, the outer container 11 can be prevented from expanding and deforming in a radially outward direction, or the outer container 11 can be prevented from compressing and deforming in a radially inward direction. Therefore, when filling the filling space 15 with high-pressure hydrogen or when discharging hydrogen from the filling space 15, deformation of the outer container can be suppressed to prevent the detachment of the clay mineral film 11b containing montmorillonite in either case.

[0092] In addition, since the reinforced plastic fiber 11c is wound around the outer surface of the outer container body 11a of the outer container 11, the outer container body 11a can be protected from the outside. Therefore, when hydrogen is filled into the filling space 15, the outer container body 11a can be more reliably prevented from expanding and deforming radially outward.

[0093] Furthermore, the inner container 12 is placed inside the outer container 11, and an upper part 12b of this inner container 12 is fixed to a first mounting part 20 that penetrates an end plate 16 of the outer container 11. Also, a bottom part 12a of the inner container 12 is fixed to a second mounting part 30 that penetrates an end plate 17 of the outer container 11. Therefore, the inner container 12 can be firmly fixed to the outer container 11 at its upper part 12b and bottom part 12a inside the outer container 11.

[0094] Furthermore, the inner container 12 is filled with hydrogen for pressure regulation through a pressure regulating valve 25. Therefore, even if the high-pressure hydrogen in the filling space 15 mixes with the hydrogen in the inner container 12, the purity of the high-pressure hydrogen in the filling space 15 does not decrease.

[0095] In addition, by adjusting the pressure of the hydrogen for pressure adjustment filled in the inner container 12 via the pressure adjustment valve 25, it is possible to adjust the amount of deformation of the inner container 12 when hydrogen is filled into the filling space 15. This makes it possible to more reliably suppress deformation of the outer container.

[0096] In addition, a pressure regulating valve 25 communicating with the inside of the inner container 12 is provided at the top of the outer container 11 of the hydrogen-filled container 10, and an on-off valve 35 communicating with the inside of the filling space 15 is provided at the bottom of the outer container 11. This allows the pressure regulating valve 25 and the on-off valve 35 to be spaced apart from each other and provided independently of each other. This simplifies the mounting structure of the pressure regulating valve 25 and the on-off valve 35 to the outer container 11, for example, compared to the case where the pressure regulating valve 25 and the on-off valve 35 are provided integrally at the top of the outer container 11.

[0097] <Second embodiment> The second embodiment of the present disclosure will be described below with reference to the drawings.

[0098] 4 and 5 are diagrams showing a second embodiment of the present disclosure.

[0099] In the second embodiment shown in FIGS. 4 and 5, the same parts as those in the first embodiment shown in FIGS. 1 to 3 and 6 are denoted by the same reference numerals.

[0100] As shown in Figures 4 and 5, the hydrogen-filled container 10 comprises an outer container 11 made of a synthetic resin, for example, polycarbonate (PC) or an acrylic polymethyl methacrylate (PMMA), and an inner container 12 made of a synthetic resin, for example, polyurethane (PU), which is placed inside the outer container 11 and forms a filling space 15 between the outer container 11 and in which hydrogen is filled.

[0101] As shown in FIG. 6, the outer container 11 has an outer container body 11a made of polycarbonate (PC) or acrylic polymethyl methacrylate (PMMA), a clay mineral film 11b containing at least montmorillonite provided on the inner surface of the outer container body 11a, and reinforced plastic fiber 11c wrapped around the outer surface of the outer container body 11a.

[0102] The outer container body 11a of the outer container 11 is a basic component of the outer container 11, and contains hydrogen gas (hereinafter also referred to as hydrogen) to be filled into the filling space 15. As will be described later, hydrogen is filled into the filling space 15 with a pressure of, for example, 40 MPa to 100 MPa, preferably 40 MPa to 50 MPa, so that the outer container 11 has a desired longitudinal elastic modulus and a desired thickness so as to be able to contain such high-pressure hydrogen.

[0103] The reinforced plastic fiber 11c is made of reinforced plastic fibers such as carbon fiber, and is wound around the outer surface of the outer container body 11a to protect and strengthen the outer container body 11a from the outside.

[0104] Furthermore, the inner container 12 is made of polyurethane (PU) and has the desired longitudinal elastic modulus and thickness, and when high-pressure hydrogen is filled into the filling space 15, it compresses and deforms inwardly, thereby preventing the outer container 11 from expanding and deforming outwardly.

[0105] That is, the clay mineral film 11b containing montmorillonite of the outer container 11 is formed into a clay-like form, and then coated on the inner surface of the outer container body 11a and dried, and is a material with low elasticity. Therefore, when high-pressure hydrogen is filled into the filling space 15, the inner container 12 compresses and deforms inwardly, suppressing the outward expansion and deformation of the outer container 11, and preventing the clay mineral film 11b containing montmorillonite from falling off from the inner surface of the outer container body 11a.

[0106] In this embodiment, the filling space 15 between the outer container 11 and the inner container 12 is filled with hydrogen (first gas) at, for example, 40 MPa to 100 MPa, and the inner container 12 is filled with hydrogen (second gas) at, for example, 0.1 MPa to 0.15 MPa for pressure adjustment.

[0107] In this case, an internal pressure of 40 MPa to 100 MPa, which is a combination of the hydrogen filled in the filling space 15 and the outside atmosphere, is applied to the inner surface of the outer container 11. In addition, an external pressure, which is approximately the same as the internal pressure of the inner surface of the outer container 11, is applied to the outer surface of the inner container 12, which is a combination of the hydrogen filled in the filling space 15 and the hydrogen for adjusting the pressure in the inner container 12.

[0108] In this embodiment, (modulus of longitudinal elasticity E1 of outer container body 11a of outer container 11 × thickness t1 of outer container body 11a of outer container) > (modulus of longitudinal elasticity E2 of inner container 12 × thickness t2 of inner container). For this reason, when high-pressure hydrogen is filled into filling space 15 of hydrogen filling container 10, inner container 12 is compressed inward and significantly deformed. As a result, pressure fluctuations within filling space 15 when filling space 15 with high-pressure hydrogen can be absorbed by radially inward compressive deformation of inner container 12. This suppresses outward expansion and deformation of outer container 11, and prevents clay mineral film 11b containing montmorillonite from falling off from the inner surface of outer container body 11a.

[0109] Next, the structure for supplying hydrogen to the filling space 15 between the outer container 11 and the inner container 12 and into the inner container 12 will be described with reference to FIGS.

[0110] The outer container body 11a of the outer container 11 has a cylindrical body 15A and a pair of end plates 16, 17 provided at both ends of the body 15A. A first attachment portion 20 is provided penetrating one end plate 16, and a second attachment portion 30 is provided penetrating the other end plate 17.

[0111] 2, the first mounting part 20 has a mouth part 21 that penetrates one of the end plates 16 and a flange 22 attached to the mouth part 21. The upper part 12b of the inner container 12 is bonded to the inside of the mouth part 21 of the first mounting part 20. In addition, the flange 22 of the first mounting part 20 is fixed to the inner surface of one of the end plates 16.

[0112] As a result, the first mounting portion 20 is fixed to one end plate 16 via the flange 22 , and the upper portion 12 b of the inner container 12 is fixed to the mouth portion 21 of the first mounting portion 20 .

[0113] Further, a pressure regulating valve 25 for regulating the pressure of hydrogen filled in the inner container 12 is connected to the outside of the mouth 21 of the first mounting part 20. The hydrogen in the inner container 12 is adjusted to 0.1 MPa to 0.15 MPa by this pressure regulating valve 25.

[0114] 5, a second mounting part 30 is provided penetrating the other end plate 17 of the outer vessel 11, and this second mounting part 30 has a flange 31 fixed to the inner surface of the other end plate 17. A lid 32 penetrating the other end plate 17 is attached to this flange 31. An opening / closing valve 35 for supplying hydrogen into the outer vessel 11 is connected to the outside of the lid 32.

[0115] High-pressure hydrogen supplied from a hydrogen supply system (not shown) is sent to the space between the lid 32 and the flange 31 via an on-off valve 35. Thereafter, high-pressure hydrogen, for example, 40 MPa to 100 MPa, is supplied from the space 32a between the lid 32 and the flange 31 through a supply hole 31a formed in the flange 31 into the filling space 15 between the outer container 11 and the inner container 12.

[0116] As shown in FIG. 5, unlike the first embodiment shown in FIG. 3, the flange 31 is not provided with a mounting ring 33, and the bottom 12a of the inner container 12 is spaced apart from the flange 31 and the end plate 16.

[0117] Since the bottom 12a of the inner container 12 is separated from the flange 31 and the end plate 16 in this manner, the inner container 12 can be easily compressed and deformed radially inward when hydrogen is filled into the filling space 15, as described below. This makes it possible to reliably suppress expansion and deformation of the outer container 11.

[0118] Next, the operation of this embodiment having the above configuration will be described.

[0119] First, as shown in FIG. 4, hydrogen (second gas) is supplied from a hydrogen supply system (not shown) through a pressure regulating valve 25 into the inner container 12 of the hydrogen-filled container 10, and the hydrogen in the inner container 12 is adjusted to, for example, 0.15 MPa.

[0120] In this case, the internal pressure of the inner container 12 becomes higher than the atmospheric pressure (0.1 MPa) inside the outer container 11. Since the inner container 12 is made of polyurethane (PU), which is easily deformed, the inner container 12 placed inside the outer container 11 expands slightly radially outward within the outer container 11 (solid line in FIG. 4).

[0121] Thereafter, hydrogen (first gas) at high pressure, for example, 40 MPa to 100 MPa, is supplied into the filling space 15 between the outer container 11 and the inner container 12 from a hydrogen supply system (not shown) via an on-off valve .

[0122] In this case, hydrogen supplied through the on-off valve 35 first enters the space 32a between the flange 31 and the lid 32, and is then supplied from this space 32a into the filling space 15 between the outer container 11 and the inner container 12 through a supply hole 31a formed in the flange 31. At this time, hydrogen at a high pressure of, for example, 40 MPa to 100 MPa is supplied into the filling space 15.

[0123] When high-pressure hydrogen is filled into the filling space 15 of the hydrogen filling container 10, pressure fluctuations occur within the filling space 15, but in this case, the inner container 12, which is easily deformed, can be significantly compressed and deformed radially inward. This makes it possible to suppress outward expansion and deformation of the outer container 11, which is easily deformed, and prevent the clay mineral film 11b containing montmorillonite from falling off.

[0124] Furthermore, when the hydrogen in the hydrogen-filled container 10 is used, the hydrogen is gradually released from the filling space 15 of the hydrogen-filled container 10 through the on-off valve 35. In this case, pressure fluctuations occur in the filling space 15, but the inner container 12 can also be largely expanded outward in the radial direction. This makes it possible to suppress inward compressive deformation of the outer container 11 and prevent the clay mineral film 11b containing montmorillonite from falling off.

[0125] As described above, according to this embodiment, outer container 11 has clay mineral film 11b containing at least montmorillonite provided on the inner surface of outer container body 11a, and therefore outer container 11 has high hydrogen barrier properties. Therefore, there is no need to make outer container 11 thicker than necessary in order to improve the hydrogen barrier properties, which allows the weight of the entire hydrogen-filled container 10 to be reduced and manufacturing costs to be reduced.

[0126] Furthermore, when filling the filling space 15 of the hydrogen filling container 10 with high-pressure hydrogen, the inner container 12 can be compressed and deformed in a radially inward direction to a greater extent than the outer container 11, which expands and deforms in a radially outward direction. Furthermore, when the high-pressure hydrogen in the filling space 15 is discharged to the outside, the inner container 12 can be expanded and deformed in a radially outward direction to a greater extent. In either case, the outer container 11 can be prevented from expanding and deforming in a radially outward direction, or the outer container 11 can be prevented from compressing and deforming in a radially inward direction. Therefore, when filling the filling space 15 with high-pressure hydrogen or when discharging hydrogen from the filling space 15, deformation of the outer container can be suppressed to prevent the detachment of the clay mineral film 11b containing montmorillonite in either case.

[0127] In addition, since the reinforced plastic fiber 11c is wound around the outer surface of the outer container body 11a of the outer container 11, the outer container body 11a can be protected from the outside. Therefore, when hydrogen is filled into the filling space 15, the outer container body 11a can be more reliably prevented from expanding and deforming radially outward.

[0128] Furthermore, the inner container 12 is disposed within the outer container 11 , and an upper portion 12 b of the inner container 12 is fixed to a first attachment portion 20 that penetrates the end plate 16 of the outer container 11 .

[0129] In addition, the bottom 12a of the inner container 12 is separated from the flange 31 and the end plate 16 of the outer container 11, and the bottom 12a of the inner container 12 maintains a free state. Therefore, when hydrogen is filled into the filling space 15, the inner container 12 can be easily compressed and deformed radially inward. This makes it possible to reliably suppress the expansion and deformation of the outer container 11.

[0130] Furthermore, the inner container 12 is filled with hydrogen for pressure regulation through a pressure regulating valve 25. Therefore, even if the high-pressure hydrogen in the filling space 15 mixes with the hydrogen in the inner container 12, the purity of the high-pressure hydrogen in the filling space 15 does not decrease.

[0131] In addition, by adjusting the pressure of the hydrogen for pressure adjustment filled in the inner container 12 via the pressure adjustment valve 25, it is possible to adjust the amount of deformation of the inner container 12 when hydrogen is filled into the filling space 15. This makes it possible to more reliably suppress deformation of the outer container.

[0132] In addition, a pressure regulating valve 25 communicating with the inside of the inner container 12 is provided at the top of the outer container 11 of the hydrogen-filled container 10, and an on-off valve 35 communicating with the inside of the filling space 15 is provided at the bottom of the outer container 11. This allows the pressure regulating valve 25 and the on-off valve 35 to be provided separately from each other at the top and bottom of the outer container 11 and independently of each other. This simplifies the mounting structure of the pressure regulating valve 25 and the on-off valve 35 to the outer container 11 compared to, for example, the case where the pressure regulating valve 25 and the on-off valve 35 are provided integrally at the top of the outer container 11, and the pressure regulating valve 25 and the on-off valve 35 can be handled independently of each other.

[0133] <Other Modifications> In each of the above-mentioned embodiments, an example has been shown in which polycarbonate (PC) or polymethyl methacrylate (PMMA) is used as the material of the outer container body 11a of the outer container 11, and polyurethane (PU) is used as the material of the inner container 12. However, the present invention is not limited to this, and the material of the outer container body 11a may be a material having a relatively large modulus of longitudinal elasticity, that is, a material that is difficult to deform, such as acrylonitrile butadiene styrene resin (ABS resin).

[0134] The inner container 12 may be made of a material having a relatively small modulus of longitudinal elasticity, that is, a material that is easily deformed, such as a rubber-based resin. [Explanation of symbols]

[0135] 10 Hydrogen filling container 11 Outer container 11a Outer container body 11b Clay mineral film 11c Reinforced Plastic Fiber 12 Inner container 12a bottom 12b Upper 15 Filling space 16 One end plate 17 Other end plate 20 First mounting part 21 Mouth 22 Flange 25 Pressure Regulating Valve 30 Second mounting part 31 Flange 31a Supply hole 32 Lid 32a Space 35 On-off valve

Claims

1. In a gas-filled container, A cylindrical outer container made of synthetic resin; a cylindrical inner container made of synthetic resin, which is disposed within the outer container, and which defines a filling space between the outer container and the filling space and into which a first gas is filled to be supplied to a consumer, and which is filled with a second gas that absorbs pressure fluctuations in the filling space; The outer container has an outer container body and a clay mineral film formed on the inner surface of the outer container body, A gas-filled container, wherein the product of the modulus of longitudinal elasticity and the thickness of the outer container body of the outer container is greater than the product of the modulus of longitudinal elasticity and the thickness of the inner container.

2. 2. The gas-filled vessel of claim 1, wherein said first gas and said second gas have the same gas composition.

3. 3. The gas-filled container according to claim 1, wherein said outer container body has a cylindrical body portion and a pair of end plates provided on both ends of said body portion.

4. 4. The gas-filled container according to claim 3, wherein a first mounting portion is provided penetrating one of the pair of end plates, the inner container is connected to the inside of the first mounting portion, and a pressure regulating valve for controlling the hydrogen pressure in the inner container is connected to the outside of the first mounting portion.

5. 5. The gas-filled container according to claim 4, further comprising a second mounting portion extending through the other of said pair of end plates, said second mounting portion having an opening / closing valve connected to the outside thereof.

6. 6. The gas-filled container according to claim 5, wherein an inner side of said second mounting portion is fixed to said inner container to hold said inner container.

7. 6. The gas-filled container according to claim 5, wherein an inner side of said second mounting portion is spaced apart from said inner container.

8. 3. The gas-filled container according to claim 1, wherein the outer container body is made of polycarbonate resin or acrylic resin, and the inner container is made of polyurethane resin.

9. 3. The gas-filled container according to claim 1, wherein a reinforced plastic fiber is wound around the outer periphery of said outer container.

10. 3. The gas-filled vessel of claim 1, wherein said clay mineral film comprises montmorillonite.

11. 2. The gas-filled container according to claim 1, wherein the ratio of the internal volume of said outer container to the internal volume of said inner container is 2:1 to 10:1.

Images