Cryopumping-resistant LH2 storage vessel

Abstract

The present disclosure provides a liquid gas storage container and a method thereof. The liquid gas storage container includes an inner shell forming a cavity. The inner shell is disposed on an insulating base. The insulating base includes an insulating sublayer. The liquid gas storage container includes an outer shell forming an insulating space between the inner shell and the outer shell. A first insulating layer is disposed within the insulating space and around the inner shell and the insulating base. A second insulating layer is disposed within the insulating space between the first insulating layer and the outer shell.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 522,652, filed June 22, 2023, which is incorporated herein by reference in its entirety.

[0002] FIELD OF THE DISCLOSURE Embodiments of the present disclosure generally relate to cryogenic vessels for storing liquid hydrogen. [Background technology]

[0003] Hydrogen is an alternative energy source to traditional fossil fuels. For example, some modes of transportation, such as automobiles, are powered by hydrogen fuel cells. Hydrogen is also finding other industrial applications, such as the Haber-Bosch process for producing fertilizer. As demand for hydrogen increases, due in part to the development and consumer adoption of more efficient hydrogen-powered vehicles and machines, there is a need to store hydrogen in industrial quantities.

[0004] Hydrogen gas has a low density. To efficiently store industrial quantities of hydrogen gas, it is liquefied. However, liquefied hydrogen gas is very cold, which places stress on its container. For example, the boiling point of liquefied hydrogen gas at one atmosphere of pressure is approximately -253°C (20°K). Therefore, liquid hydrogen is typically stored at conditions close to ambient pressure and a temperature of approximately 20 Kelvin.

[0005] Liquid hydrogen storage requires insulation to reduce heat transfer between the liquid hydrogen and the external environment. Without insulation, the liquid hydrogen would rapidly change phase to gaseous hydrogen (commonly known as evaporation), and the outside of the storage container would be cold enough to liquefy or freeze most components of air, such as nitrogen and oxygen.

[0006] Liquid hydrogen is cold enough to condense and freeze atmospheric gases, such as nitrogen or oxygen gas, in its presence, on the walls of the vessel containing the liquid hydrogen. The condensation and freezing of the atmospheric gases transfers heat to the liquid hydrogen, causing it to evaporate. The evaporated hydrogen gas may have to be vented, resulting in losses. As a result, some liquid hydrogen containment vessels include vacuum insulation to avoid the heat load caused by the condensation or freezing of the atmospheric gases.

[0007] Conventional liquid hydrogen storage vessels consist of a double-walled steel vessel with vacuum insulation. The inner steel vessel wall, which stores the liquid hydrogen, is suspended from the outer steel vessel wall. Insulating material is placed between the two vessel walls under vacuum. In all insulating materials, the evacuation of air prevents convective heat transfer and also prevents heat transfer that would otherwise occur if gas in the insulated space liquefies against the cold inner vessel, thereby reducing the insulation's effectiveness.

[0008] The outer steel vessel wall of a liquid hydrogen storage vessel is limited in size due to the tendency of the steel wall to buckle due to the vacuum load of the vacuum insulation. Therefore, the outer vessel must be designed to withstand the pressure differential created by evacuating the insulated space, which could cause the outer vessel to buckle inward and collapse.

[0009] Vacuum-jacketed insulation is cost-effective for smaller storage vessels, but for very large storage vessels, designing the outer vessel for vacuum can be prohibitively expensive. Rocket fuel tanks are often insulated with a single layer of foam due to weight constraints, but they experience very high evaporation rates, very short storage times measured in hours, adsorption of water vapor and gases that can cause damage to the foam, and ice formation on the exterior surface. This behavior is unacceptable for multiple fill cycles or long-term storage.

[0010] Therefore, what is needed in the art is a cost-effective method for insulating large liquid hydrogen gas storage vessels. Summary of the Invention

[0011] In one aspect, the present disclosure generally provides a liquid gas storage container. The liquid gas storage container includes an inner shell forming a cavity. The inner shell is disposed on an insulating base. The insulating base includes an insulating sublayer. The liquid gas storage container includes an outer shell forming an insulating space between the inner shell and the outer shell. A first insulating layer is disposed within the insulating space and around the inner shell and the insulating base. A second insulating layer is disposed within the insulating space between the first insulating layer and the outer shell.

[0012] In another aspect, the disclosure generally provides a liquid gas storage container. The liquid gas storage container includes an inner shell forming a cavity. The inner shell is disposed on an insulating base. The insulating base includes an insulating sublayer. The liquid gas storage container includes an outer shell forming an insulating space between the inner shell and the outer shell. A first insulating layer is disposed within the insulating space and around the inner shell and the insulating base. A second insulating layer is disposed within the insulating space between the first insulating layer and the outer shell. A membrane layer is disposed between the first insulating layer and the second insulating layer.

[0013] So that the above features briefly summarized above can be understood in detail, a more particular description can be had by reference to exemplary embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings depict only typical exemplary embodiments and are not to be considered as limiting the scope thereof. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic cross-sectional side view of a first liquid hydrogen storage vessel according to embodiments described herein. [Figure 2] FIG. 2 is a schematic cross-sectional side view of a second liquid hydrogen storage vessel according to embodiments described herein. [Figure 3A] 1 is a schematic cross-sectional side view of an exemplary liquid hydrogen storage vessel according to embodiments described herein. [Figure 3B]1 is a schematic cross-sectional side view of an exemplary liquid hydrogen storage vessel according to embodiments described herein. [Figure 3C] 1 is a schematic cross-sectional side view of an exemplary liquid hydrogen storage vessel according to embodiments described herein. [Figure 4A] FIG. 2 is an enlarged view of a portion of a wall forming a liquid hydrogen storage vessel according to embodiments described herein. [Figure 4B] FIG. 2 is an enlarged view of a portion of a wall forming a liquid hydrogen storage vessel according to embodiments described herein. [Figure 5] 1 is an enlarged view of a portion of an insulating base according to embodiments described herein. DETAILED DESCRIPTION OF THE INVENTION

[0015] For ease of understanding, where possible, like reference numerals have been used to designate like elements common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

[0016] The present disclosure generally relates to a cryogenic vessel for storing liquid hydrogen. The present disclosure provides a cryogenic vessel that allows for the use of thinner walls while maintaining efficient cryogenic storage, thereby reducing the cost of the cryogenic vessel. The cryogenic vessel can include an inner shell disposed on an insulating base, which allows the cryogenic vessel to be mounted on a flat surface. The insulating base can include a first insulating sublayer, a planarizing layer, and a second insulating sublayer, thereby providing a stable, flat surface for the inner shell to rest on while reducing thermal conductivity. The insulating base can be enclosed within a skirt and / or anchor straps that support the weight of the inner shell, thereby reducing foam compression and / or thermal conductivity complications. The skirt can be secured to the base, thereby preventing movement of the inner shell within the cryogenic vessel. Advantageously, securing the inner vessel via the skirt and / or anchor straps can prevent the inner shell from rising within the cryogenic vessel due to internal hydrogen pressure acting on the inner shell.

[0017] The outer insulating layer is filled with gas to maintain a pressure in the insulating space near atmospheric pressure outside the outer vessel so that external pressure on the outer vessel is substantially reduced. This reduces the cost of the outer vessel. If the inner vessel contracts due to the cold liquid hydrogen product or if gas condenses, additional gas is supplied to the outer insulating layer to prevent a drop in pressure. The contraction of the inner vessel may depend on the radius of the inner vessel multiplied by the temperature difference between ambient temperature and the inner vessel temperature. At least one embodiment utilizes a low thermal conductivity gas, such as nitrogen or argon, in the insulating space, e.g., the inner insulating layer and / or the outer insulating layer.

[0018] The thermal insulation layer structures described herein can be used in any application that stores or transports cryogenic liquids, such as pipes. For example, the thermal insulation layer structures described herein can store higher temperature liquids, such as liquid helium or liquid natural gas. Although a spherical liquid gas storage vessel is shown, the thermal insulation layers, membranes, and shell structures described herein can also be used with cylindrical storage vessels, or storage vessels of other shapes.

[0019] If the liquid hydrogen product must be stored at pressures significantly above ambient pressure, the simplest shape is a sphere, although non-spherical pressure vessel shapes (generally having rounded shapes) are also possible. If the liquid hydrogen product can be stored at or near ambient pressure vessels of other shapes, such as cylinders, they can be used. The insulating space can have a consistent thickness throughout to reduce interfacial temperature variations.

[0020] FIG. 1 shows a schematic cross-sectional side view of a liquid hydrogen storage vessel 100. The liquid hydrogen storage vessel 100 includes an inner shell 102 that defines a cavity 104. The cavity 104 is defined by an inner surface 122 of the inner shell 102. The cavity 104 is configured to hold liquid hydrogen or another liquid gas. The cavity 104 has a capacity of 3,000 m 3 Larger, e.g. 4,000m 3 Larger, e.g. 5,000m 3 Larger, e.g. 6,000m 3 Larger, e.g. 6,500m 3 Larger, e.g. 7,000m 3 Larger, e.g., about 10,000 m 3 Larger, e.g., about 50,000 m 3 Larger, e.g., about 75,000 m 3 Larger, e.g., about 100,000 m 3 Larger, e.g., about 150,000 m 3 Larger, e.g., about 200,000 m 3 In some embodiments, the volume is about 5,000 m 3 ~about 250,000m3 , or more, e.g., about 100,000 m 3 ~About 200,000m 3 The inner shell 102 is formed of a cryogenic metal material, such as cryogenic steel or another cryogenic metal alloy, that is available at a temperature of about 20 Kelvin. The inner shell 102 may be substantially cylindrical and / or spherical. In some embodiments, the inner shell 102 may be cylindrical with substantially vertical sidewalls, a domed top surface, and a flat bottom surface. In some embodiments, the cylindrical inner shell may include rounded corners. Without being bound by theory, rounded corners may reduce stress concentrations compared to sharp corners, and rounded corners may reduce stress cracking of the insulation.

[0021] The inner shell 102 is disposed on an insulating base 130. The insulating base can include a first insulating sublayer 132. The first insulating sublayer 132 can include closed-cell foam, open-cell foam, or any other load-bearing insulation. The first insulating sublayer 132 can include a thermal barrier coating, such as aerogel, disposed on the first insulating sublayer 132 so that the thermal barrier coating is in contact with the interior of the inner shell 102. Without being bound by theory, the thermal barrier coating can improve cryosorption of gas molecules not removed by the vacuum pump. The first insulating sublayer 132 is laterally defined by a skirt 138. The first insulating sublayer 132 is horizontally defined by a planarizing layer 134 and / or an interleaving layer.

[0022] The first insulating sublayer 132 is a load-bearing foam, and the first insulating sublayer 132 can support a pressure of about 800 Kpa to about 2,400 Kpa. The first insulating sublayer 132 is maintained under vacuum, for example, at a pressure of about 1 mTorr to about 1,000 mTorr, e.g., about 100 mTorr to about 900 mTorr, about 100 mTorr to about 800 mTorr, or about 500 mTorr to about 700 mTorr. The first insulating sublayer 132 includes a thickness of about 50 mm to about 1,000 mm, e.g., about 50 mm to about 800 mm, about 100 mm to about 700 mm, or about 200 mm to about 500 mm. The first insulating sublayer 132 can include a thermal expansion coefficient similar to that of the material of the inner shell 102, allowing the first insulating sublayer 132 to contract and / or expand at a similar rate to the inner shell 102. Without being bound by theory, the first insulating sublayer 132 in combination with the vacuum in the first insulating sublayer 132 can reduce and / or prevent runaway cryopumping by reducing gas liquefaction and / or freezing near the inner shell 102.

[0023] The first insulating sublayer 132 can be disposed on the planarizing layer 134. The planarizing layer 134 can include a cement material and / or a metal material. The planarizing layer 134 can have a thickness of about 0 mm to about 200 mm, e.g., about 10 mm to about 150 mm, about 50 mm to about 150 mm, or about 50 mm to about 100 mm. Without being bound by theory, the planarizing layer 134 can provide a uniform and / or flat surface for disposing the first insulating sublayer 132, thereby allowing the inner shell 102 to rest on the flat surface.

[0024] The planarizing layer 134 is disposed on the second insulating sublayer 136. The planarizing layer 134 may include an insulator such as metal, aerogel, and / or concrete. Without being bound by theory, the planarizing layer 134 may provide protection for the second insulating sublayer 136, described below, to prevent heat from penetrating or contacting the second insulating sublayer 136. For example, the planarizing layer 134 may include concrete to prevent heat from interacting with the second insulating sublayer 136 during welding and / or forming of the first insulating sublayer 132.

[0025] The second insulating sublayer 136 can include closed-cell foam and / or open-cell foam. The second insulating sublayer 136 is a load-bearing foam, and the second insulating sublayer 136 can support a pressure of about 800 Kpa to about 2,400 Kpa. The second insulating sublayer 136 can have a thickness of about 200 mm to about 5,000 mm, e.g., about 200 mm to about 4,000 mm, about 500 mm to about 3,000 mm, or about 1,000 mm to about 2,000 mm. The second insulating sublayer 136 can be filled with a gas, e.g., hydrogen, nitrogen, argon, helium, or a combination thereof. The second insulating sublayer 136 can be maintained at atmospheric pressure. Without being bound by theory, the second insulating sublayer 136 can further insulate the insulating base 130, thereby improving the cold storage efficiency of the cryogenic vessel.

[0026] Optionally, an interleaved layer can be disposed between the first insulation sublayer 132 and the second insulation sublayer 136. The interleaved layer can include a composite, cement, metal, polymer, foam, or a combination thereof. The interleaved layer can include a thickness of about 0 mm to about 200 mm, e.g., about 10 mm to about 150 mm, about 50 mm to about 150 mm, or about 50 mm to about 100 mm. Without being bound by theory, the interleaved layer can stop crack formation and increase the strength of the first insulation sublayer 132 and / or the second insulation sublayer 136 by preventing crack propagation throughout the insulation base 130.

[0027] Optionally, the interleaved layer can include a foam layer. The foam layer can be disposed on and / or over the second insulating sublayer 136 to form a braid, e.g., a layer of collapsed foam cells. Without being bound by theory, the braid can reduce permeability due to increased foam density, thereby reducing cryogenic pumping and increasing cryogenic cooling capacity.

[0028] The skirt 138 is disposed along the sidewall 140 of the insulating base 130. The skirt can support the main body of the inner shell 102 and the insulation supported by the inner shell 102. The skirt 138 comprises a metallic material. The skirt 138 comprises a thickness of about 5 mm to about 50 mm, e.g., about 5 mm to about 40 mm, about 10 mm to about 40 mm, or about 20 mm to about 30 mm. Without being bound by theory, the skirt 138 can provide structural support to the insulating base 130, thereby providing support against radial vacuum pressure. The skirt 138 can be mechanically coupled, e.g., fastened, to the base 142 via one or more anchors 144. The one or more anchors 144 can be embedded in an upper surface 146 of the base 142. Additionally or alternatively, the anchors 144 can extend from the upper surface 146 to the skirt 138 (not shown). The base can comprise a cement material and / or a metallic material. The base 142 may include one or more heating elements 150. Without being bound by theory, the one or more heating elements 150 may reduce and / or prevent freezing of materials disposed below the base 142, thereby preventing damage to the base 142.

[0029] The one or more anchors 144 may attach the skirt 138 to the base 142 to prevent the inner shell 102 from moving and / or shifting within the liquid hydrogen storage vessel 100, thereby preventing the insulating space from being compromised. The one or more anchors 144 may include fasteners, straps, bolts, nuts, rivets, or a combination thereof. The one or more anchors may include cryogenic steel, stainless steel, and / or a combination thereof. The one or more anchors 144 may extend along the length of the skirt 138 and / or may be positioned along the top surface 146 of the base 142. Without being bound by theory, securing the skirt 138 to the base 142 via anchors 144 positioned along the top surface 146 of the base 142 may prevent the inner shell 102 from lifting off the insulating base 130 after seismic acceleration and / or internal pressure loads.

[0030] An outer shell 106 is formed around the inner shell 102 and the skirt 138. An insulating space 105 is formed between the inner shell 102 and the outer shell 106. The insulating space 105 includes at least two insulating layers, such as a first insulating layer 108 and a second insulating layer 110. The first insulating layer 108 is disposed proximal to the inner shell 102 and proximal to the skirt 138 such that the first insulating layer 108 covers the outer surface 120 of the inner shell 102 and the skirt 138. In some embodiments, the first insulating layer 108 can form a coating around the inner shell 102 and the skirt 138 such that the inner shell 102 and the skirt 138 are encapsulated. The first insulating layer 108 is attached to the outer surface 120 of the inner shell 102 and the skirt 138. The first insulation layer 108 is chemically bonded to the exterior surface 120, which may include forming a bond using an epoxy bond and / or forming a bond through a reaction between the first insulation layer 108 and the exterior surface 120. The first insulation layer 108 is a closed-cell insulation material. Closed-cell foams include polyethylene, polyurethane, polyisocyanurate, and polystyrene foam.

[0031] Closed-cell foams are formed by cells with thin polymer membranes arranged in a polyhedral shape, e.g., about 0.01 mm to about 1.0 mm, e.g., about 0.01 mm to about 0.5 mm, about 0.05 mm to about 0.1 mm, or about 0.07 mm to about 0.1 mm. The cells are filled with a gas, such as a blowing agent, which expands the cells in the foam. For example, the blowing agent can include an unsaturated organic compound such as a hydrofluoroolefin. At room temperature, atmospheric gases, such as nitrogen, can diffuse into the cells, where the blowing agent diffuses.

[0032] As the outer surface 120 of the inner shell cools, the gas in the cells of the first insulation layer 108 proximal to the outer surface 120 and / or skirt 138 also cools. The gas can liquefy and / or freeze. As the gas liquefies and / or freezes, the pressure in the cells decreases, creating a pressure differential across the cell walls of the closed-cell foam. The pressure differential can be between about 0.01 atm and about 1 atm, e.g., between about 0.01 atm and about 0.5 atm, between about 0.01 atm and about 0.1 atm, or between about 0.01 atm and about 0.05 atm. If the cell walls of the closed-cell foam are gas permeable, gas can diffuse from the surrounding higher-pressure cells into the lower-pressure cells and liquefy. This process can continue until the cells proximal to the outer surface 120 are substantially filled with liquefied and / or frozen gas. If the exterior surface 120 is heated, such as during maintenance, the liquefied and / or solidified gas may vaporize and rupture the cell.

[0033] To prevent damage, the closed-cell foam can be cryogenically cooled, which can reduce and / or prevent gas diffusion into the cells of the closed-cell foam due to the reduced permeability of the closed-cell foam. Without being bound by theory, reducing the permeability of the closed-cell foam reduces the likelihood of the closed-cell foam bursting when heated. Furthermore, without being bound by theory, the first insulation layer 108 can reduce the complexity of thermal insulation damage when heating the inner shell 102.

[0034] The first insulating layer 108 is filled with a first gas, such as a blowing agent, nitrogen, or a nitrogen-containing gas mixture. For example, the first insulating layer 108 can be initially filled with a hydrofluoroolefin first gas, and after a period of time, such as seconds, minutes, hours, days, years, or decades, the first insulating layer 108 can be filled with a second nitrogen gas. In some examples, the first insulating layer 108 can be filled with air at a concentration similar to that found in ambient air. The first insulating layer 108 is used adjacent to the inner shell 102, and the first insulating layer 108 is sufficiently thick so that the temperature of the outer surface 128 of the first insulating layer 108 exceeds 77 Kelvin (the point at which nitrogen boils or liquefies).

[0035] The closed-cell insulating material forming the first insulating layer 108 has a cell size (diameter) of about 1 μm to less than about 1 cm, such as 0.1 mm to about 1.0 mm. The first conductivity of the first insulating layer 108 is about 0.0001 W / (m·K) to about 0.050 W / (m·K), for example, about 0.010 W / (m·K) to about 0.040 W / (m·K), for example, about 0.010 W / (m·K) to about 0.030 W / (m·K), for example, about 0.015 W / (m·K) to about 0.030 W / (m·K), for example, about 0.020 W / (m·K) to about 0.030 W / (m·K).

[0036] A second insulation layer 110 is also disposed within the insulation space 105. The second insulation layer 110 is disposed between the first insulation layer 108 and the outer shell 106. The second insulation layer 110 is disposed inside the outer surface 128 of the first insulation layer 108 and the inner surface 124 of the outer shell 106. The cross section of the inner surface 124 of the outer shell 106 may be circular and / or cylindrical. The thermal conductivity of the second insulation layer 110 may be higher than the thermal conductivity of the first insulation layer 108. The second insulation layer 110 may be formed from a bulk material, such as a gas, foam, glass fiber, aerogel, expanded perlite, glass microspheres, an insulator with low thermal conductivity, and / or a combination thereof. For example, the second insulation layer 110 may include a gas. As a further example, the second insulation layer 110 may include a mixture of glass fiber, glass microspheres, and perlite. As a further example, the second insulating layer 110 can include expanded perlite. The glass microspheres can have diameters of about 1 nm to about 100 μm, e.g., about 1 nm to about 10 μm, about 500 nm to about 10 μm, or about 500 nm to about 1 μm. The second insulating layer 110 can also be a closed-cell foam. Without being bound by theory, a second insulating layer 110 including a mixture of glass fibers, glass microspheres, and perlite can prevent movement of the glass microspheres and perlite within the insulating layer because the glass fibers restrain and / or hold the glass microspheres and / or perlite in place.

[0037] In at least one embodiment, the second insulating layer 110 can include perlite having a flow permeability of about 40 Darcy to about 50 Darcy. In at least one embodiment, the second insulating layer 110 can include glass microspheres having a flow permeability of about 3 Darcy to about 10 Darcy. In at least one embodiment, the second insulating layer 110 can include a mixture of perlite and glass microspheres. The mixture can include about 1% to about 99% perlite by weight and about 1% to about 99% glass microspheres by weight. For example, the mixture can include about 60% to about 99% perlite by weight and about 1% to about 40% glass microspheres by weight. As a further example, the mixture can include about 80% to about 99% perlite by weight and about 1% to about 20% glass microspheres by weight. The mixture can include a flow permeability of about 6 Darcy to about 45 Darcy, e.g., about 6 Darcy to about 40 Darcy, about 6 Darcy to about 30 Darcy, about 6 Darcy to about 20 Darcy, or about 10 Darcy to about 20 Darcy. Without being bound by theory, a second insulating layer having a flow permeability of about 6 Darcy to about 40 Darcy can reduce runaway cryopumping, thereby increasing the efficiency of the temperature insulation of the second insulating layer 110.

[0038] The second insulation layer 110 is filled with a second gas, which may be a single gas or a combination of gases. The second gas may be greater than 50% nitrogen, greater than 50% argon, or greater than 50% nitrogen and argon, as measured by partial pressure. In some embodiments, the second gas combination may be greater than 60% nitrogen and argon, e.g., greater than 70%, e.g., greater than 80%, e.g., greater than 90% nitrogen and argon. The nitrogen and / or argon concentration in the first insulation layer 108 may be maintained by exposing the first insulation layer 108 to a nitrogen and / or argon gas source. In some examples, dry air may be utilized. Nitrogen and / or argon gas may be used in the second insulation layer 110 during formation of the second insulation layer 110 on the outer surface 128 of the first insulation layer 108.

[0039] The concentration of hydrogen or helium gas is reduced within the second insulating layer 110 due to the higher electrical conductivity of hydrogen and helium compared to nitrogen and argon.

[0040] The second conductivity of the second insulating layer 110 is approximately 0.010 W / (m·K) to 0.100 W / (m·K). The thermal conductivity of the first insulating layer 108 may be less than twice the thermal conductivity of the second insulating layer 110, for example, less than three times the thermal conductivity of the second insulating layer 110, for example, less than four times the thermal conductivity of the second insulating layer 110, for example, less than five times the thermal conductivity of the second insulating layer 110, for example, less than seven times the thermal conductivity of the second insulating layer 110, or for example, less than ten times the thermal conductivity of the second insulating layer 110.

[0041] At least two insulating layers are disposed between the inner shell 102 and the outer shell 106, for example, within the insulating space 105. The first insulating layer 108, which may be a closed-cell foam, can prevent runaway cryopumping. The second insulating layer 110 is also suitable for reducing manufacturing costs and reducing the gas supply required to maintain pressure within the outer insulating layer. The gas within the second insulating layer 110 is a gas or gas mixture with a relatively low conductivity that liquefies at approximately 20 K, the temperature of liquid hydrogen. The temperature of the outer edge of the first insulating layer is higher than the condensation temperature of the gas or gas mixture within the second insulating layer to prevent condensation and runaway cryopumping. The pressure is maintained substantially above a perfect vacuum, reducing the cost of the outer vessel. The pressure within the second insulating layer 110 is maintained at about 0.5 atmospheres to about 2 atmospheres, for example, about 0.5 atmospheres to about 1.5 atmospheres, for example, about 0.75 atmospheres to about 1.25 atmospheres, for example, about 0.8 atmospheres to about 1.2 atmospheres, for example, about 0.9 atmospheres to about 1.1 atmospheres, for example, about 0.95 atmospheres to about 1.05 atmospheres, for example, about 1 atmosphere. The pressure within the first insulating layer 108 may be about 1.0 atmosphere at its first surface, but is reduced to about 0.2 atmospheres or less, or about 0.1 atmosphere or less, near the inner shell 102.

[0042] Optionally, an interleaved layer can be disposed between the first insulation layer 108 and the second insulation layer 110. The interleaved layer can include a composite, cement, metal, polymer, foam, or a combination thereof. The interleaved layer can include a thickness of about 0 mm to about 200 mm, e.g., about 10 mm to about 150 mm, about 50 mm to about 150 mm, or about 50 mm to about 100 mm. Without being bound by theory, the interleaved layer can stop crack formation and increase the strength of the first insulation layer 108 and / or the second insulation layer 110 by preventing crack propagation throughout the insulation space 105.

[0043] Optionally, the interleaved layer can include a foam layer. The foam layer can be disposed on and / or over the second insulation layer 110 to form a braid, e.g., a layer of collapsed foam cells. Without being bound by theory, the braid can reduce permeability due to increased foam density, thereby reducing cryogenic pumping and increasing cryogenic cooling capacity.

[0044] The conduit 112 extends into the cavity 104 and penetrates each of the inner shell 102, the first insulation layer 108, the second insulation layer 110, and the outer shell 106. The conduit 112 may be a pipe or tube that extends into the cavity 104 to fill or drain liquid hydrogen from the cavity 104. The conduit 112 is positioned so that an open end of the conduit 112 is within the cavity 104 and the other end of the conduit 112 is connected to a hydrogen source 114 outside the body of the liquid hydrogen storage container 100. The hydrogen source 114 may include one or more feed lines to a pump or condenser, as well as various other hydrogen sources. While only a single conduit is shown, it should be understood that more than one conduit may be included, such as a filling conduit, a withdrawal conduit, a conduit for venting boil-off gas, and optionally other conduits. In some examples, filling and evaporation may pass through conduits through the top, and withdrawal lines may pass through the top or bottom. Other configurations are possible.

[0045] 2 shows a schematic cross-sectional side view of another liquid hydrogen storage vessel 200. The liquid hydrogen storage vessel 200 includes an intermediate shell 210. The intermediate shell 210 may be an impermeable membrane, such as a metal or non-metal, depending on the embodiment and the type of insulation utilized for one or both of the first insulation layer 108 and the second insulation layer 110. In some examples, when an impermeable membrane is used as the intermediate shell, closed-cell foam and / or open-cell foam may be used as the first insulation layer 108.

[0046] The intermediate shell 210 is an impermeable membrane that prevents gas or liquid from passing through the intermediate shell 210, yet the intermediate shell 210 can still flex and bend to maintain contact with both the first insulation layer 108 and the second insulation layer 110. The intermediate shell 210 may be impermeable at temperatures between about 50 Kelvin and about 100 Kelvin, such as between about 60 Kelvin and about 90 Kelvin, such as between about 70 Kelvin and about 90 Kelvin, for example, between about 75 Kelvin and about 85 Kelvin. The intermediate shell 210 is at least partially impermeable because its permeability coefficient is sufficiently low to provide a predetermined level of impermeability for the use of the storage vessel. Without being bound by theory, the permeability coefficient may be low enough to prevent and / or reduce damage to the first insulation layer when the tank is warmed during maintenance and / or when not in cryogenic cooling operation.

[0047] In embodiments in which the intermediate shell 210 is an impermeable membrane, the membrane layer may be one or a combination of epoxy, polyethylene terephthalate (Mylar), aluminized polyethylene terephthalate, polypropylene, polyimide, polyetherimide, polyetheretherketone, or various metal foils. Other materials are contemplated but not explicitly listed herein. The membrane may have a resistance of 400 kg / mm ​​at a temperature of approximately 77 Kelvin. 2 exceeding, for example, 500 kg / mm 2 exceeding, for example, 600 kg / mm 2 exceeding, for example, 700 kg / mm 2The membrane may have a modulus of elasticity greater than 1 / 2. The modulus of elasticity allows the membrane to flex along with the first insulation layer 108 and second insulation layer 110 as the first insulation layer 108 and / or inner shell 102 contract and expand during cooling and heating of the first insulation layer 108 and inner shell 102. The membrane also helps seal the first insulation layer 108 from the second insulation layer 110. Thus, if there are gaps or cracks in the first insulation layer 108, the presence of the membrane may reduce or eliminate the effectiveness of cryopumping. The use of a flexible membrane intermediate shell 210 may further allow for the utilization of additional materials, such as open-cell foam, as part of the first insulation layer 108.

[0048] Optionally, a sealant is also disposed around any openings in the intermediate shell 210 so that there is no fluid communication between the first insulation layer 108 and the second insulation layer 110, even if something, such as the support skirt 118, passes through the intermediate shell 210. The sealant can include an epoxy resin, such as LOCTITE® Stycast 2850. The sealant can include a diphenol resin, such as epichlorohydrin-4,4'-isopropylidene. The sealant must be able to provide a seal at temperatures below 100 Kelvin.

[0049] Optionally, the collar can be welded to the skirt, piping, and / or support that penetrates the first insulation layer. The collar can include a film chemically bonded to an outer surface of the collar and to the first insulation layer. Without being bound by theory, welding a collar with a film to the skirt, piping, and / or support that penetrates the first insulation layer can increase the cryogenic cooling capacity of the cryocontainer.

[0050] The intermediate shell 210, also referred to as an interlayer, is disposed between the first insulation layer 108 and the second insulation layer 110. In such an example, the intermediate shell 210 may be metal, polymer, or a combination thereof.

[0051] The intermediate shell 210 may be formed of a material that is not self-supporting or is otherwise flexible. The first insulation layer 108 may be self-supporting if the intermediate shell 210 is an impermeable membrane. In such an example, the first insulation layer 108 has sufficient structural rigidity to support the pressure exerted by the gas in the second insulation layer 110. Spray-on foam and aerogel blankets are examples of self-supporting materials that may be used for the first insulation layer 108. The insulating material of the first insulation layer 108 may include a compressive strength of about 14 psi to about 100 psi, e.g., about 14 psi to about 90 psi, about 20 psi to about 80 psi, or about 30 psi to about 70 psi, and may support loads that penetrate the impermeable membrane from both the pressure differential and any forces exerted by the granular material used to insulate the second insulation layer 110.

[0052] The liquid hydrogen storage vessel 200 can include one or more gas inputs, such as a first gas source 202 and a second gas source 204, and one or more pumps or compressors in fluid communication with the second insulating layer. In some examples, the one or more gas inputs and the one or more pumps are part of or function as a pressure regulator. The one or more pumps or compressors, which can be fluidly coupled to the first insulating layer 108, help maintain a predetermined pressure within the first insulating layer 108. The liquefaction or freezing of gas within the first insulating layer 108 creates a vacuum (e.g., a pressure below atmospheric pressure) whose absolute value can vary from cell to cell or which can exist in a nonlinear gradient from one surface to the opposite surface. During operation, the pressure within the cells of the foam of the first insulating layer can reach a predetermined level of vacuum (e.g., subatmospheric pressure), providing beneficial thermal conductivity within the cells. For example, the first gas source 202 may be fluidly coupled to the first insulation layer 108 via a first conduit 206, and the second gas source 204 is fluidly coupled to the second insulation layer 110 via a conduit 208. The second gas source 204 may be similar to the first gas source 202 in that it may include a connection to one or more pumps, compressors, or one or more other fluid delivery systems. When using a first gas source, the first insulation layer 108 and the second insulation layer 110 may receive different gases from different gas sources.

[0053] 3A , the second insulating sublayer 136 can extend along the base 142 such that the inner shell 102 and the outer shell 106 are disposed on the second insulating sublayer 136. The second insulating sublayer 136 can be exposed to the first insulating layer 108 and / or the second insulating layer 110. One or more anchors 144 can extend through the second insulating sublayer 136, thereby preventing gas leakage and subsequent condensation and / or freezing of the one or more anchors.

[0054] A protective layer 302 is provided over the first insulating sublayer 132. The protective layer 302 may include a metal layer, a cement layer, a polymer layer, and / or other suitable material for thermally protecting the first insulating sublayer 132. Without being bound by theory, the protective layer 302 may protect the first insulating sublayer 132 from heat during manufacturing of the inner shell 102, thereby preventing cracking and / or deformation during manufacturing.

[0055] As shown in FIG. 3B , the first insulating sublayer 132 can be disposed on the second insulating sublayer 136, with the first insulating sublayer 132 contacting the skirt 138 and the sidewall 304 of the second insulating sublayer 136. The first insulating sublayer 132 includes the insulation of the first insulating layer 108 described herein. Without being bound by theory, disposing the first insulating sublayer along the sidewalls of the skirt 138 and the second insulating sublayer may result in a reduction in gaps between the skirt and the first insulating sublayer. Additionally, without being bound by theory, cracking at the bottom corners of the inner shell 102 may be reduced.

[0056] 3C , the second insulating sublayer 136 can extend along the base 142 such that the inner shell 102 is disposed on the second insulating sublayer 136. The second insulating sublayer 136 can be exposed to the first insulating layer 108, with the skirt 138 terminating at an upper surface 310 of the second insulating sublayer 136. The first insulating sublayer 132 can include the insulation of the first insulating layer 108 as described herein. Without being bound by theory, reduced heat leakage occurs due to the skirt terminating at the upper surface of the second insulating sublayer.

[0057] Figure 4A shows an enlarged view of a portion of a wall forming the liquid hydrogen storage vessel 100 of Figure 1. Over the portion of the liquid hydrogen storage vessel 100 is a graph 400 showing a schematic diagram of the temperature of the liquid hydrogen storage vessel 100 at various points within the body of the liquid hydrogen storage vessel 100. The graph 400 includes a vertical axis 402 that indicates temperature (T) and a horizontal axis 404 that indicates position within the liquid hydrogen storage vessel 100 relative to the center of the cavity 104.

[0058] The cavity 104 is maintained at a first temperature T1. The first temperature T1 is below the boiling point of the gas within the cavity 104. Therefore, the first temperature T1 is approximately 20 Kelvin or less while storing liquid hydrogen. The temperature is increased within the inner shell 102 to a second temperature T2. The second temperature T2 may be substantially similar to the first temperature T1, such as between approximately 20 Kelvin and approximately 25 Kelvin, or between approximately 20 Kelvin and approximately 22 Kelvin. In some examples, the difference between the first temperature T1 and the second temperature T2 is less than 2 Kelvin, such as less than 1 Kelvin, or less than 0.5 Kelvin. The second temperature T2 may be directly related to the first thickness L1 of the inner shell 102. The first thickness L1 is about 10 mm to about 100 mm, for example, about 10 mm to about 75 mm, for example, about 10 mm to about 50 mm, for example, about 15 mm to about 45 mm, for example, about 20 mm to about 45 mm, for example, about 20 mm to about 30 mm.

[0059] The temperature is increased from the second temperature T2 to a third temperature T3 through the first insulating layer 108. The third temperature T3 is higher than the condensation point of the gas in the second insulating layer 110, for example, higher than the condensation point of nitrogen or argon. The third temperature T3 may be higher than the condensation point of the gas in the second insulating layer 110 by less than about 20 Kelvin, less than about 10 Kelvin, for example, less than about 5 Kelvin. When the gas in the second insulating layer 110 is nitrogen, the third temperature T3 is greater than 77 Kelvin, for example, between about 78 Kelvin and about 80 Kelvin, for example, between about 78 Kelvin and about 90 Kelvin, for example, between about 78 Kelvin and about 100 Kelvin. In another example, the third temperature T3 may be as high as 150 Kelvin to 170 Kelvin to further reduce the possibility of condensation.

[0060] To reach temperatures above 77 Kelvin, the first insulation layer 108 has a thickness L2 of about 0.1 meters to about 1 meter, e.g., about 0.55 meters to about 0.75 meters, e.g., about 1 meter to about 1.5 meters, e.g., about 1.1 meters to about 1.4 meters, e.g., about 1.2 meters to about 1.3 meters. The total thickness of both insulation layers combined is in the range of about 0.2 meters to about 5 meters, e.g., 1 meter to about 3 meters, resulting in easier and cheaper construction, transportation, and maintenance. The relative thicknesses of the insulation layers are selected to achieve a predetermined temperature T3, while the combined thickness (and conductivity) of the first insulation layer 108 and the second insulation layer 110 are selected to provide a predetermined amount of leakage / boil-off rate (or lack thereof).

[0061] As the second insulation layer 110 extends from the outer surface 128 of the first insulation layer 108 to the inner surface 124 of the outer shell 106, the temperature increases until it reaches a fourth temperature T4. The fourth temperature is between the third temperature T3 and the ambient temperature T6 surrounding the outer surface 126 of the outer shell 106. Thus, the fourth temperature T4 may be between about 80 Kelvin and about 320 Kelvin, e.g., between about 100 Kelvin and about 315 Kelvin, e.g., between about 200 Kelvin and about 310 Kelvin, e.g., between about 250 Kelvin and about 310 Kelvin, e.g., between about 273 Kelvin and about 310 Kelvin. In one example, the fourth temperature T4 is within about 2 to 5 Kelvin of the ambient temperature T6. The second insulation layer has a third thickness L3. The third thickness L3 is as described above.

[0062] As the outer shell 106 extends from the inner surface 124 to the outer surface 126, the temperature within the outer shell 106 increases from a fourth temperature T4 to a fifth temperature T5. The fifth temperature T5 is close to the ambient temperature T6 of the environment surrounding the outer shell 106, such as between about 250 Kelvin and about 315 Kelvin, between about 265 Kelvin and about 310 Kelvin, or between about 273 Kelvin and about 305 Kelvin. The thickness of the outer shell 106 is a fourth thickness L4. The fourth thickness L4 is less than the first thickness L1 of the inner shell 102 because the inner shell 102 has a pressurized cavity 104 formed by the inner surface 122. The outer shell 106 provides overall support and protection for the insulation layer. However, in some situations where additional protection of the insulation and / or contents is desired, the thickness L4 may be greater. The fourth thickness L4 is about 10 mm to about 100 mm, for example, about 10 mm to about 50 mm, for example, about 10 mm to about 30 mm, for example, about 14 mm to about 25 mm, for example, about 15 mm to about 20 mm.

[0063] 4B shows an enlarged view of a portion of the wall forming the liquid hydrogen storage vessel 200 of FIG. 2. Over the portion of the liquid hydrogen storage vessel 200 is a graph 450 showing a schematic diagram of the temperature of the liquid hydrogen storage vessel 200 at various points within the body of the liquid hydrogen storage vessel 200. Graph 450 is similar to graph 400 of FIG. 4A, but further includes a portion corresponding to the temperature gradient within the intermediate shell 210. The temperature within the intermediate shell 210 ranges from a third temperature T3 to a seventh temperature T7. The seventh temperature may be substantially the same as the third temperature T3, or may be slightly greater than the third temperature T3, for example, between about 0 Kelvin and about 3 Kelvin greater than the third temperature T3.

[0064] The intermediate shell 210 has a fifth thickness L5 of about 10 mm to about 100 mm, for example, about 10 mm to about 75 mm, for example, about 10 mm to about 50 mm, for example, about 15 mm to about 45 mm, for example, about 20 mm to about 45 mm, for example, about 20 mm to about 30 mm. The fifth thickness L5 is between the first thickness L1 and the fourth thickness L4. However, other thicknesses and / or relative thicknesses are contemplated.

[0065] The embodiments described herein enable better and more reliable devices for insulating liquid gas storage vessels, such as liquid hydrogen storage vessels. The embodiments described herein are more economical and easier to manufacture. The disclosed embodiments reduce cryopumping within the first insulating layer 108 by using closed cells, which reduces gas diffusion through the first insulating layer 108. The second insulating layer 110 can be insulated through the use of a mixture of glass microspheres and perlite, thereby increasing the insulating capacity compared to conventional insulating devices. While this disclosure illustrates a mixture of glass microspheres and perlite in system 100, the mixture of glass microspheres and perlite can be implemented in any system suitable for insulating one or more temperatures. For example, the mixture of glass microspheres and perlite can be injected into a spherical system.

[0066] Some embodiments, which can be combined with other embodiments, utilize an additional intermediate shell 210 (e.g., a membrane) between the first insulating layer 108 and the second insulating layer 110. The intermediate shell 210 may be an impermeable membrane that can flex to accommodate changes in the dimensions of the first insulating layer 108 or the metal / metal alloy shell. The impermeable membrane can further reduce the possibility of cryopumping.

[0067] 5 shows an enlarged view of a portion of the insulated base 130 of the liquid hydrogen storage vessel. Above the portion of the liquid hydrogen storage vessel is a graph 500 showing a schematic representation of the temperature of the liquid hydrogen storage vessel at various points within the body of the liquid hydrogen storage vessel. Graph 500 includes a vertical axis 502 showing height (x) within the liquid hydrogen storage vessel relative to the center of the cavity, and a horizontal axis 504 showing temperature (T).

[0068] The cavity 104 is maintained at a first temperature T1. The first temperature T1 is lower than the boiling point of the gas in the cavity 104. Therefore, the first temperature T1 is about 20 Kelvin or less while storing liquid hydrogen. The temperature increases from the first temperature T1 to a second temperature T8 through the first insulating sublayer 132. The second temperature T8 is higher than the condensation point of the gas in the second insulating sublayer 136, for example, higher than the condensation point of nitrogen or argon. The second temperature T8 may be less than about 10 Kelvin, for example, less than about 5 Kelvin, higher than the condensation point of the gas in the second insulating sublayer 136. For example, the second temperature T8 is greater than 77 Kelvin, for example, between about 78 Kelvin and about 80 Kelvin, for example, between about 78 Kelvin and about 90 Kelvin, or for example, between about 78 Kelvin and about 100 Kelvin. As a further example, to further reduce the possibility of condensation, the second temperature T8 may be as high as 150 K to 170 K. Optionally, if the thickness of the first insulating sublayer 132 is greater than the thickness of the second insulating sublayer 136, the second temperature T8 may be lower than the third temperature T 10 It may be about 90% to about 100%.

[0069] The first insulating sublayer 132 has a thickness D1 of about 50 millimeters (mm) to about 5000 mm, for example, about 50 mm to about 4000 mm, about 80 mm to about 3000 mm, or about 100 mm to about 1000 mm.

[0070] The temperature can remain stable in the planarization layer 134. The planarization layer 134 has a second thickness D2 of about 0 mm to about 200 mm, e.g., about 0 mm to about 180 mm, about 10 mm to about 150 mm, or about 20 mm to about 100 mm. The temperature can continue to increase until a third temperature T9 is reached. The third temperature is the sum of the second temperature T8 and the temperature T9 surrounding the second insulating sublayer 136, e.g., at the base 142. 10 Therefore, the third temperature T9 may be between about 80 Kelvin and about 320 Kelvin, for example, between about 100 Kelvin and about 315 Kelvin, for example, between about 200 Kelvin and about 310 Kelvin, for example, between about 250 Kelvin and about 310 Kelvin. In one example, the third temperature T9 is between about 80 Kelvin and about 320 Kelvin, for example, between about 100 Kelvin and about 315 Kelvin, for example, between about 200 Kelvin and about 310 Kelvin, for example, between about 250 Kelvin and about 310 Kelvin. 10 The temperature T is within about 2 to 5 Kelvin. 10The second insulating sublayer 136 may have a third thickness D3. The third thickness D3 is between about 200 mm and about 5000 mm, for example, between about 200 mm and about 4000 mm, between about 500 mm and about 3000 mm, or between about 1000 mm and about 2000 mm.

[0071] The total thickness of the insulating base 130 is from about 1000 mm to about 5000 mm, for example, from 1000 mm to 3000 mm, resulting in easier and cheaper construction, transportation, and maintenance. The relative thicknesses of the first insulating sublayer 132, the planarizing layer 134, and the second insulating sublayer 136 can provide a predetermined amount (or lack thereof) of leakage / boil-off rate.

[0072] Overall, the present disclosure provides a cryogenic container that allows for the use of thinner walls while maintaining efficient cryogenic storage, thereby reducing the cost of the cryogenic container. The cryogenic container can include an inner shell disposed on an insulating base, which allows the cryogenic container to be mounted on a flat surface. The insulating base can include a first insulating sublayer, a planarizing layer, and a second insulating sublayer, thereby providing a stable, flat surface for the inner shell to rest on while reducing thermal conductivity. The insulating base can be enclosed within a skirt that supports the weight of the inner shell, thereby reducing foam compression and / or thermal conductivity complications. Securing the skirt can prevent movement of the inner shell within the cryogenic container.

[0073] While the forgoing is directed to embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof, which scope is determined by the following claims.

Claims

1. A liquid gas storage vessel, an inner shell defining a cavity, the inner shell disposed on an insulating base, the insulating base including a first insulating sublayer; an outer shell forming a thermal insulation space between the inner shell and the outer shell; a first insulating layer disposed within the insulating space around the inner shell and the insulating base; a second insulating layer disposed within the insulating space between the first insulating layer and the outer shell; A liquid gas storage vessel comprising:

2. The liquid gas storage vessel of claim 1 , further comprising a skirt disposed along a sidewall of the insulating base.

3. The liquid gas storage vessel of claim 2 , wherein the first insulating layer is disposed around the skirt within the insulating space.

4. The liquid gas storage vessel of claim 3 , further comprising one or more anchors mechanically coupled to the skirt.

5. 10. The liquid gas storage vessel of claim 1, wherein the first insulating sublayer comprises a pressure of about 100 mTorr to about 1000 mTorr.

6. The liquid gas storage vessel of claim 1 , wherein the first insulating sublayer comprises load-bearing insulation.

7. 7. The liquid gas storage vessel of claim 6, wherein the first insulating sublayer comprises a load-bearing foam comprising a closed-cell foam.

8. between the first and second insulating sublayers; or Between the first insulating layer and the second insulating layer, 10. The liquid gas storage vessel of claim 1, further comprising an interleaved layer disposed in

9. The liquid gas storage vessel of claim 1 , further comprising a protective layer disposed on the first insulating sublayer.

10. The liquid gas storage vessel of claim 1 , wherein the second insulating layer comprises a bulk fill material.

11. 11. The liquid gas storage vessel of claim 10, wherein the bulk fill material comprises one or more of perlite, glass microspheres, glass fiber, or mixtures thereof.

12. 12. The liquid gas storage vessel of claim 11, wherein the mixture comprises about 60% to about 99% by weight perlite and about 1% to about 40% by weight glass microspheres.

13. A liquid gas storage vessel, an inner shell defining a cavity, the inner shell disposed on an insulating base, the insulating base including a first insulating sublayer; an outer shell forming a thermal insulation space between the inner shell and the outer shell; a first insulating layer disposed within the insulating space around the inner shell and the insulating base; a second insulating layer disposed within the insulating space between the first insulating layer and the outer shell; a membrane layer disposed between the first and second thermal insulation layers; A liquid gas storage vessel comprising:

14. 14. The liquid gas storage vessel of claim 13, wherein the membrane layer comprises one or more of aluminized Mylar, Mylar, epoxy, waterglass, or xerogel.

15. 14. The liquid gas storage vessel of claim 13, further comprising a skirt disposed along a sidewall of the insulating base, the first insulating layer being disposed around the skirt within the insulating space.

16. 16. The liquid gas storage vessel of claim 15, further comprising one or more anchors mechanically coupled to the skirt.

17. 17. The liquid gas storage vessel of claim 16, wherein the first insulating sublayer comprises load-bearing insulation.

18. 20. The liquid gas storage vessel of claim 17, wherein the first insulating sublayer comprises a load-bearing foam comprising a closed-cell foam.

19. 14. The liquid gas storage vessel of claim 13, further comprising an interleaving layer disposed between the first and second insulating sublayers.

20. 14. The liquid gas storage vessel of claim 13, further comprising a protective layer disposed on the first insulating sublayer.

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