Low-temperature-resistant pumped liquid LH2 storage vessel

Abstract

A method and apparatus for storing a liquid gas, such as liquid hydrogen, is provided. The liquid gas container includes a plurality of insulating layers to enable non-vacuum insulation while reducing cryogenic pumping. The inner insulating layer is formed of a material having a closed-cell structure and is thick enough to make a temperature at an outer surface of the inner insulating layer higher than a boiling point of a gas within the outer insulating layer. The insulating material of the outer insulating layer may have a perforated structure.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 522,651, filed on June 22, 2023, which is incorporated herein by reference in its entirety.

[0003] Government Rights

[0004] This invention was made with Government support under Grant No. DE-EE0009387 awarded by the Department of Energy. The Government has certain rights in this invention. Technical Field

[0005] Embodiments of the present disclosure generally relate to cryogenic vessels for storing liquid hydrogen. Background Art

[0006] Hydrogen is an energy source that can replace conventional fossil fuels. For example, some types of vehicles (such as cars) are powered by hydrogen fuel cells. Hydrogen can also be used in other industrial applications, such as the Haber-Bosh process for producing fertilizers. As the demand for hydrogen increases (partly due to the development of more efficient hydrogen-powered vehicles and machines, and the adoption of such vehicles and machines by consumers), there is a need to store hydrogen in industrial quantities.

[0007] Hydrogen gas has a low density. In order to efficiently store industrial-grade quantities of hydrogen gas, the hydrogen gas is liquefied. However, liquefied hydrogen gas is extremely cold, which puts pressure on its container. For example, the boiling point of liquefied hydrogen gas at one atmosphere of pressure is about -253°C (20°K). Therefore, liquid hydrogen is typically stored under conditions close to ambient pressure and a temperature of about 20 Kelvin (K).

[0008] Storing liquid hydrogen requires insulation to reduce heat transfer between the liquid hydrogen and the external environment. Without insulation, the liquid hydrogen will quickly change phase to gaseous hydrogen (commonly known as boil-off), and the outside of the storage vessel will be cold enough to liquefy or freeze most components of the air, such as nitrogen and oxygen.

[0009] The liquid hydrogen is cold enough to cause constituent gases in the air (such as nitrogen or oxygen) to condense and freeze in the presence of the liquid hydrogen, such as on the walls of the vessel containing the liquid hydrogen. The condensation and freezing of the atmospheric gases transfer heat to the liquid hydrogen, which vaporizes the liquid hydrogen. The vaporized hydrogen gas may have to be vented, which results in losses. Therefore, some liquid hydrogen containment vessels include vacuum insulation to avoid heat loads caused by condensation or freezing of atmospheric gases.

[0010] Conventional liquid hydrogen storage vessels are formed of double-walled steel vessels with vacuum insulation. The inner steel vessel wall storing the liquid hydrogen is suspended from the outer steel vessel wall. The insulating material is located between the two vessel walls under vacuum conditions. For all insulating materials, evacuating the air can prevent convective heat transfer and can also prevent the gas in the insulation space from contacting the cold inner container and liquefying and causing heat transfer that will reduce the effectiveness of the insulation.

[0011] The size of the outer steel vessel wall of a liquid hydrogen storage vessel is limited because the steel wall is susceptible to buckling due to the vacuum load of the vacuum insulation. Therefore, the outer vessel must be designed to withstand the pressure difference caused by evacuating the insulation space, otherwise it may cause the outer vessel to buckle and collapse inward.

[0012] While vacuum jacket insulation is cost effective for smaller storage vessels, designing a vacuum outer container may be cost prohibitive for very large storage vessels. Rocket fuel tanks are often insulated with a single layer of foam due to weight constraints, but they have very high boil-off rates, very short storage times (measured in hours), experience adsorption of water vapor and gases that can damage the foam, and ice formation on the outer surface. This behavior is unacceptable for multiple filling cycles or long-term storage.

[0013] Therefore, what is needed in the art is a cost-effective method of insulating large liquid hydrogen gas storage vessels. Summary of the invention

[0014] The present disclosure generally relates to a cryogenic vessel for storing liquid hydrogen.

[0015] In one embodiment, a liquid gas storage container is described. The liquid gas storage container includes: an inner shell forming a cavity; and an outer shell forming an insulating volume between the outer shell and the inner shell. A first insulating layer is disposed in the insulating volume and surrounds the inner shell. The first insulating layer is formed of a closed-cell insulating material. A second insulating layer is disposed in the insulating volume between the first insulating layer and the outer shell.

[0016] In another embodiment, a liquid gas storage container is described. The liquid gas storage container includes: an inner shell forming a cavity; and an outer shell forming an insulating volume between the outer shell and the inner shell. A first insulating layer is disposed in the insulating volume and surrounding the inner shell, and is formed of a closed-cell insulating material. A second insulating layer is disposed in the insulating volume between the first insulating layer and the outer shell. A membrane layer is disposed between the first insulating layer and the second insulating layer.

[0017] In another embodiment, a liquid gas storage container is described. The liquid gas storage container includes an inner shell forming a cavity; and an outer shell forming an insulating volume between the inner shell and the outer shell. A first insulating layer is disposed in the insulating volume and around the inner shell, and is formed of a closed-cell insulating material. Gas is disposed in the insulating volume between the first insulating layer and the outer shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to be able to understand the above-mentioned features of the present disclosure in detail, a more specific description of the present disclosure briefly summarized above may be made with reference to the embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only exemplary embodiments and are therefore not to be considered as limiting the scope thereof, and other equivalent embodiments may be admitted.

[0019] Figure 1 A schematic cross-sectional side view of a liquid hydrogen storage container according to embodiments described herein is illustrated.

[0020] Figure 2 A schematic cross-sectional side view of a liquid hydrogen storage container according to embodiments described herein is illustrated.

[0021] Figure 3A The formation of the embodiment described herein is illustrated Figure 1 A close-up view of a portion of the wall of a liquid hydrogen storage container.

[0022] Figure 3B The formation of the embodiment described herein is illustrated Figure 2 A close-up view of a portion of the wall of a liquid hydrogen storage container.

[0023] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation. DETAILED DESCRIPTION

[0024] The present disclosure generally relates to a cryogenic vessel for storing liquid hydrogen. More specifically, the present disclosure relates to a cryogenic vessel having multiple insulating layers that can reduce cryopumping and achieve lower cost manufacturing and maintenance of large liquid hydrogen storage containers. The cryogenic vessel includes a first insulating layer that includes a closed-cell polymer foam that can condense and prevent runaway cryopumping due to reduced permeability. Additionally, the cryogenic vessel includes a second insulating layer that includes perlite or glass microspheres that can reduce flow permeability to less than 40 Darcy, thereby reducing runaway cryopumping due to reduced permeability. Advantageously, the cryogenic vessel of the present disclosure can provide enhanced storage capacity compared to conventional cryogenic vessels, wherein the cryogenic vessel can provide cold storage capacity for about 25 years to about 60 years.

[0025] Storage vessels that can insulate liquid hydrogen without vacuum and without liquefaction of the gas touching a cold surface will significantly reduce the cost of large-scale liquid hydrogen storage compared to conventional liquid hydrogen storage containers. In the embodiments described herein, the inner shell contains the liquid hydrogen product. The space between the outer shell and the inner shell contains at least two insulation layers. The insulation adjacent to the inner shell is referred to as the inner insulation layer. The insulation between the inner insulation layer and the outer shell is referred to as the outer insulation layer.

[0026] The outer insulating layer is filled with gas to maintain the pressure in the insulating space close to the atmospheric pressure outside the outer vessel, so that the external pressure on the outer vessel is substantially reduced. This reduces the cost of the outer vessel. When the inner vessel shrinks due to the cold liquid hydrogen product, or in the event of gas condensation, additional gas is supplied to the outer insulating layer to prevent the pressure from dropping. The shrinkage of the inner vessel may depend on the radius of the inner vessel multiplied by the temperature difference between the ambient temperature and the temperature of the inner vessel. At least one embodiment utilizes a low thermal conductivity gas, such as nitrogen or argon, within the insulating space (e.g., the inner insulating layer and / or the outer insulating layer).

[0027] The insulation layer structures described herein can be used in any application (such as pipelines) for storing or transporting cryogenic liquids. For example, the insulation layer structures described herein can store liquid helium or liquids with higher temperatures. The figure illustrates a spherical liquid gas storage container, however, the insulation layer, membrane and shell structures described herein can also be used in cylindrical storage containers or other shaped storage containers.

[0028] When the liquid hydrogen product must be stored at pressures significantly above ambient pressure, the most straightforward geometry is spherical, but non-spherical pressure vessel shapes (with generally rounded geometries) are possible. When the liquid hydrogen product can be stored at or near ambient pressure, other shapes of vessels, such as cylinders, can be used. The entire insulation space can have a consistent thickness to reduce interface temperature variations.

[0029] Figure 1 A schematic cross-sectional side view of a liquid gas storage container 100 is illustrated. The liquid gas storage container 100 includes an inner shell 102 forming a cavity 104. The cavity 104 is formed by an inner surface 122 of the inner shell 102. The cavity 104 is configured to store liquid hydrogen or another liquid gas. The cavity 104 may have a volume greater than 3,000 m 3 Volume, such as greater than 4,000m 3 , such as greater than 5,000m 3 , such as greater than 6,000m 3 , such as greater than 6,500m 3 , such as greater than 7,000m 3 , such as greater than about 10,000 m 3 , such as greater than about 50,000m 3 , such as greater than about 75,000m 3 , such as greater than about 100,000m 3 , such as greater than about 150,000m 3 , such as greater than about 200,000m 3 In some embodiments, the volume is about 5,000 m 3 About 250,000m 3 or greater, such as about 100,000m 3 to about 200,000m 3 The inner housing 102 is formed of a cryogenic metal material, such as cryogenic steel or another cryogenic metal alloy that can be utilized at a temperature of about 20 Kelvin. The inner housing 102 can be substantially spherical. In some embodiments, the inner housing 102 can be cylindrical with hemispheres at either end, or can have a cross-section that is a polygon, but with rounded corners. Without being bound by theory, the rounded corners can provide reduced stress concentrations compared to sharp corners, wherein the rounded corners can provide reduced stress cracking of the insulation.

[0030] The outer shell 106 is formed around the inner shell 102. The insulating volume 105 is formed between the inner shell 102 and the outer shell 106. The insulating volume 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 around the inner shell 102 such that the first insulating layer 108 is wrapped around the inner shell 102 and covers an outer surface 120 of the inner shell 102. The first insulating layer 108 is attached to the outer surface 120 of the inner shell 102. The first insulating layer 108 is chemically bonded to the outer surface 120, wherein the chemical bonding may include forming a bond using an epoxy bond and / or forming a bond via a reaction between the first insulating layer 108 and the outer surface 120. The first insulating layer 108 is a closed cell insulating material. Closed cell foams include polyethylene, polyurethane, polyisocyanurate, and polystyrene foams.

[0031] Closed cell foam is formed by having pores of a thin polymer film arranged in a polyhedral shape, for example, about 0.01 mm to about 1.0 mm, such as 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 pores are filled with a gas, such as a blowing agent, which is a gas used to expand the pores in the foam. For example, the blowing agent may include an unsaturated organic compound, such as a hydrofluoroolefin. At room temperature, atmospheric gases such as nitrogen can diffuse into the pores, wherein the blowing agent diffuses out therefrom.

[0032] As the outer surface 120 of the inner shell cools, the gas in the pores of the first insulating layer 108 near the outer surface 120 also cools. The gas may liquefy and / or solidify. As the gas liquefies and / or solidifies, the pressure in the pores drops, thereby creating a pressure difference on the pore walls of the closed-cell foam. The pressure difference may be from about 0.01 atmosphere to about 1 atmosphere, for example, from about 0.01 atmosphere to about 0.5 atmosphere, from about 0.01 atmosphere to about 0.1 atmosphere, or from about 0.01 atmosphere to about 0.05 atmosphere. When the pore walls of the closed-cell foam are permeable to the gas, the gas will diffuse from around the pores with higher pressure to the pores with lower pressure and liquefy. This process may continue until the pores near the outer surface 120 are substantially filled with liquefied and / or frozen gas. When the outer surface 120 heats up, such as during maintenance, the liquefied and / or solidified gas will evaporate and may rupture the pores.

[0033] To prevent damage, the closed-cell foam may be cooled to a cryogenic temperature, thereby reducing and / or preventing the diffusion of gas into the pores of the closed-cell foam due to the reduced permeability of the closed-cell foam. Without being bound by theory, by reducing the permeability of the closed-cell foam, the likelihood of cracking when the closed-cell foam is heated can be reduced. Additionally, without being bound by theory, the first insulation layer 108 can reduce the problem of insulation performance damage when the inner shell 102 is heated.

[0034] The first insulating layer 108 is filled with a first gas, such as a blowing agent, nitrogen, or a nitrogen-containing mixed gas. For example, the first insulating layer 108 may initially be filled with a first gas of a hydrofluoroolefin, wherein after a period of time (e.g., seconds, minutes, hours, days, years, or decades), the first insulating layer 108 may be filled with a second gas of nitrogen. In some examples, the first insulating layer 108 may be filled with air having a concentration similar to that of the gas present in ambient air. The first insulating layer 108 is used adjacent to the inner shell 102, and the first insulating layer 108 is thick enough to make the temperature at the outer surface 128 of the first insulating layer 108 higher than the condensation temperature of the gas in the second insulating layer 110, for example, about 77 Kelvin (the vaporization or liquefaction point of nitrogen).

[0035] The closed-cell insulating material forming the first insulating layer 108 has a pore size (diameter) of less than about 1 μm to about 1 cm, such as 0.1 mm to about 1.0 mm. For example, the pore size of the closed-cell insulating material can be about 10 μm to about 100 μm. The first insulating layer 108 has a first conductivity of about 0.0001 W / (m·K) to about 0.050 W / (m·K), such as about 0.010 W / (m·K) to about 0.040 W / (m·K), such as about 0.010 W / (m·K) to about 0.030 W / (m·K), such as about 0.015 W / (m·K) to about 0.030 W / (m·K), such as about 0.020 W / (m·K) to about 0.030 W / (m·K).

[0036] A second insulating layer 110 is also disposed within the insulating volume 105. The second insulating layer 110 is disposed between the first insulating layer 108 and the outer shell 106. The second insulating layer 110 is disposed on the outer surface 128 of the first insulating layer 108 and inside the inner surface 124 of the outer shell 106. The cross-section of the inner surface 124 of the outer shell 106 is substantially circular. The second insulating layer 110 has a thermal conductivity that is optionally higher than the thermal conductivity of the first insulating layer 108. The second insulating layer 110 can be a gas, foam, aerogel, expanded perlite, glass microspheres, or another insulation with low thermal conductivity. The glass microspheres can include a diameter of about 1 nm to about 100 μm, for example, 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 100 can be a closed-cell foam.

[0037] In at least one embodiment, the second insulating layer 110 may include perlite having a flow permeability of about 40 Darcy to about 50 Darcy. In at least one embodiment, the second insulating layer 110 may 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 may include a mixture of perlite and glass microspheres. The mixture may include about 1wt% to about 99wt% of perlite and about 1wt% to about 99wt% of glass microspheres. For example, the mixture may include about 60wt% to about 99wt% of perlite and about 1wt% to about 40wt% of glass microspheres. For another example, the mixture may include about 80wt% to about 99wt% of perlite and about 1wt% to about 20wt% of glass microspheres. The mixture may include a flow permeability of about 6 Darcy to about 45 Darcy, for example, 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 may reduce uncontrolled cryopumping, thereby increasing the efficiency of the temperature insulation of the second insulating layer 110 .

[0038] The second insulating layer 110 is filled with a second gas, which may be a single entity or a combination of gas combinations. The second gas may be a combination of more than 50% nitrogen, more than 50% argon, or more than 50% nitrogen and argon, measured in partial pressure. In some embodiments, the second gas combination may be one or a combination of more than 60% nitrogen and argon, such as one or a combination of more than 70% nitrogen and argon, such as one or a combination of more than 80% nitrogen and argon, such as one or a combination of more than 90% nitrogen and argon. By exposing the first insulating layer 108 to a nitrogen and / or argon gas source, the nitrogen and / or argon concentration within the first insulating layer 108 may be maintained. In some examples, dry air may be used. During the formation of the second insulating layer 110 onto the outer surface 128 of the first insulating layer 108, nitrogen and / or argon may be utilized in the second insulating layer 110.

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

[0040] The second insulating layer 110 has a second thermal conductivity of about 0.010 W / (m·K) to about 0.100 W / (m·K). The thermal conductivity of the first insulating layer 108 may be 2 times lower than the thermal conductivity of the second insulating layer 110, such as 3 times lower than the thermal conductivity of the second insulating layer 110, such as 4 times lower than the thermal conductivity of the second insulating layer 110, such as 5 times lower than the thermal conductivity of the second insulating layer 110, such as 7 times lower than the thermal conductivity of the second insulating layer 110, such as 10 times lower than the thermal conductivity of the second insulating layer 110.

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

[0042] Optionally, a staggered layer may be disposed between the first insulating layer 108 and the second insulating layer 110. The staggered layer may include a composite material, cement, metal, polymer, foam, or a combination thereof. The staggered layer may include a thickness from about 0 mm to about 200 mm, for example, 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 staggered layer may prevent crack formation and increase the strength of the first insulating layer 108 and / or the second insulating layer 110 by preventing crack propagation from occurring throughout the insulating volume 105.

[0043] Optionally, the interleaved layers may include a foam layer. The foam layer may be disposed on and / or over the second insulating layer 110 to form a knitline, for example, a layer of collapsed foam. Without being bound by theory, the knitline may reduce permeability due to increased foam density, thereby reducing cryogenic pumping and enhancing cryogenic cooling capabilities.

[0044] The conduit 112 extends into the cavity 104 and passes through each of the inner shell 102, the first insulating layer 108, the second insulating layer 110, and the outer shell 106. The conduit 112 may be a pipe or a tube that extends into the cavity 104 to fill or discharge the liquid hydrogen in the cavity 104. The conduit 112 is arranged so that the open end of the conduit 112 is in the cavity 104, and the other end of the conduit 112 is connected to a hydrogen gas source 114 outside the body of the liquid hydrogen storage container 100. The hydrogen gas source 114 may include a pump or a condenser, and one or more feed lines to various other hydrogen gas sources 114. Although only a single conduit is shown, it will be understood that more than one conduit may be included, such as a conduit for filling, a conduit for extracting, a conduit for discharging vaporized gas, and optionally other conduits. In some examples, the filling and vaporization conduits pass through the top, and the extraction line may pass through the top or the bottom. Other configurations are also contemplated.

[0045] The support skirt 118 is utilized to support the body of the liquid hydrogen storage container 100. The support skirt 118 may be a concrete skirt outside the outer surface 126 of the outer shell 106, and then or as the skirt passes through the outer surface 126 of the outer shell 106, transitions to a metal skirt. The support skirt 118 may be a plurality of discontinuous columns outside the outer surface 126 of the outer shell 106, such that the plurality of discontinuous columns provide support to the outer shell 106. The portion of the support skirt 118 that passes through the outer shell 106 and enters the insulating volume 105 may include a plurality of hangers, such that the support skirt 118 is discontinuous within the insulating volume 105, such that the entirety of each of the first insulating layer 108 and the second insulating layer 110 is still in fluid communication, and the insulating space is not divided into separate chambers by the support skirt 118.

[0046] Figure 2 A schematic cross-sectional side view of another liquid hydrogen storage container 200 is illustrated. The liquid hydrogen container 200 includes an intermediate shell 210. The intermediate shell 210 can be an impermeable membrane, such as metal or non-metal, depending on the implementation and the type of insulation utilized in 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 can be used as the first insulation layer 108.

[0047] The intermediate housing 210 is an impermeable membrane so that gas or liquid does not pass through the intermediate housing 210, but the intermediate housing 210 is still able to flex and bend to maintain contact with both the first insulating layer 108 and the second insulating layer 110. The intermediate housing 210 can be impermeable at a temperature of about 50 Kelvin to about 100 Kelvin (such as about 60 Kelvin to about 90 Kelvin, such as about 70 Kelvin to about 90 Kelvin, such as about 75 Kelvin to about 85 Kelvin). The reason why the intermediate housing 210 is impermeable is at least in part that its permeability coefficient is low enough to provide a predetermined impermeability level for the use of the storage vessel. Without being bound by theory, the permeability coefficient can be low enough to prevent and / or reduce damage to the first insulating layer when the tank is heated during maintenance and / or when it is not in a cryogenically cooled operation.

[0048] In embodiments where the intermediate housing 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 are not explicitly listed herein. At a temperature of about 77 Kelvin, the membrane may have a thermal conductivity greater than 400 kg / mm 2 The elastic modulus is greater than 500 kg / mm 2 , such as greater than 600kg / mm 2 , such as greater than 700kg / mm 2 The membrane may have a thickness of about 0.1 mm to about 10 mm, such as about 0.1 mm to about 8 mm, about 0.5 mm to about 5 mm, or about 1 mm to about 3 mm. Without being bound by theory, a membrane having a thickness of about 0.1 mm to about 10 mm may allow the membrane to flex so as to avoid tearing and / or cracking when applying the first insulating layer 108. The elastic modulus allows the membrane to flex with the first insulating layer 108 and the second insulating layer 110 as the first insulating layer 108 and / or the inner housing 102 contract and expand during cooling and heating of the first insulating layer 108 and the inner housing 102. The membrane also helps to seal the first insulating layer 108 to the second insulating layer 110. Therefore, if there are any gaps or cracks in the first insulating layer 108, the effects of cryopumping may be reduced or eliminated in the presence of the membrane. Using the intermediate housing 210 as a flexible membrane may further enable the use of other materials as part of the first insulating layer 108, such as open-cell foam.

[0049] Optionally, a sealant is also provided around any openings in the intermediate housing 210 so that even if something passes through the intermediate housing 210, such as the support skirt 118, there is no fluid communication between the first insulating layer 108 and the second insulating layer 110. The sealant may include an epoxy resin, such as Stycast 2850. The sealant may include a diphenolic resin such as epichlorohydrin-4,4'-isopropylidene. The sealant must be able to provide a seal at temperatures below 100 Kelvin.

[0050] Optionally, the collar may be welded to the skirt, tube, and / or support that penetrates the first insulating layer. The collar may include a film chemically bonded to the outer surface of the collar and the first insulating layer. Without being bound by theory, by welding the collar with the film to the skirt, tube, and / or support that penetrates the first insulating layer, the cryogenic cooling capability of the cryogenic vessel may be enhanced.

[0051] The intermediate housing 210 may also be referred to as a middle film, and is disposed between the first insulating layer 108 and the second insulating layer 110. In this example, the intermediate housing 210 may be a metal, a polymer, or a combination thereof.

[0052] The intermediate housing 210 may be formed of a non-self-supporting material or a flexible material. When the intermediate housing 210 is an impermeable membrane, the first insulating layer 108 may be self-supporting. In this example, the first insulating layer 108 has enough structural rigidity to support the pressure applied by the gas in the second insulating layer 110. Spray foam and aerogel blankets may be examples of self-supporting materials that can be used in the first insulating layer 108. The insulating material of the first insulating layer 108 may include a compressive strength of about 14 psi to about 100 psi, such as about 14 psi to about 90 psi, about 20 psi to about 80 psi, or about 30 psi to about 70 psi, to support the load of both the pressure difference transmitted through the impermeable membrane and any force applied by the granular material used for insulation in the second insulating layer 110.

[0053] The liquid hydrogen storage container 200 may include one or more gas inputs and one or more pumps or compressors in fluid communication with the first insulating layer 108. In some examples, the one or more gas inputs and the one or more pumps are part of or function as a pressure regulator. One or more pumps or compressors fluidly coupled to the first insulating layer 108 help maintain a predetermined pressure within the first insulating layer 108. The liquefaction or freezing of the gas within the first insulating layer 108 creates a vacuum (e.g., a pressure below atmospheric pressure), the absolute value of which may vary from pore to pore, or may have a nonlinear gradient from one surface to the opposite surface. During operation, the pressure within the pores of the foam of the first insulating layer is allowed to reach a predetermined level of vacuum (e.g., sub-atmospheric pressure), thereby providing beneficial thermal conductivity within the pores.

[0054] The second gas source 208 is in fluid communication with the second insulation layer 110 via the conduit 204. The second gas source 208 can be similar to the first gas source 206 in that it can be one or more pumps, compressors, or connections to one or more other fluid delivery systems. The conduit 204 is in fluid communication with the second insulation layer 110, but not in fluid communication with the first insulation layer 108. When the first gas source is used, the first insulation layer 108 and the second insulation layer 110 receive different gases from different gas sources 206, 208.

[0055] Figure 3A Illustrate the formation Figure 1 100. Above the portion of the liquid hydrogen storage container 100 is a graph 300 illustrating a schematic diagram of the temperature of the liquid hydrogen storage container 100 at various points within the body of the liquid hydrogen storage container 100. The graph 300 includes a vertical axis 302 illustrating temperature (T) and a horizontal axis 304 illustrating a position within the liquid hydrogen storage container 100 relative to the center of the cavity 104.

[0056] The cavity 104 is maintained at a first temperature T 1 The first temperature T 1 is at or below the boiling point of the gas in the cavity 104. Therefore, when storing liquid hydrogen, the first temperature T 1 The temperature rises to a second temperature T in the inner housing 102. 2 The second temperature T 2 The first temperature T 1 , such as about 20 Kelvin to about 25 Kelvin, such as about 20 Kelvin to about 22 Kelvin. In some examples, the first temperature T 1 With the second temperature T 2 The difference between the second temperature T and the second temperature T is less than 2 Kelvin, such as less than 1 Kelvin, such as less than 0.5 Kelvin. 2 The first thickness L of the inner shell 102 may be 1 Directly related. The first thickness L 1 From about 10 mm to about 100 mm, such as from about 10 mm to about 75 mm, such as from about 10 mm to about 50 mm, such as from about 15 mm to about 45 mm, such as from about 20 mm to about 45 mm, such as from about 20 mm to about 30 mm.

[0057] The temperature is increased from the second temperature T by the first insulating layer 108 2 Rising to the third temperature T 3 The third temperature T 3 The third temperature T is higher than the condensation point of the gas in the second insulating layer 110, such as higher than the condensation point of nitrogen or argon. 3The third temperature T may be higher than the condensation point of the gas in the second insulating layer 110 by less than about 10 degrees, such as less than about 5 degrees. When the gas in the second insulating layer 110 is nitrogen, the third temperature T 3 The third temperature T3 may be above 77 Kelvin, such as about 78 Kelvin to about 80 Kelvin, such as about 78 Kelvin to about 90 Kelvin, such as about 78 Kelvin to about 100 Kelvin. In other examples, the third temperature T3 may be 150 Kelvin to 170 Kelvin to further reduce the possibility of condensation. In yet other examples, the third temperature T3 may be 150 Kelvin to 170 Kelvin to further reduce the possibility of condensation. 3 It can be the ambient temperature.

[0058] To achieve a temperature above 77 Kelvin, the first insulating layer 108 has a thickness L of about 0.1 m to about 5 m. 2 , such as about 0.55 meters to about 4 meters, such as about 1 meter to about 4 meters, such as about 1.1 meters to about 3.5 meters, such as about 2 meters to about 3 meters. The total thickness of the insulation layers 108 and 110 combined is in the range of about 0.2 meters to about 5 meters, such as 1 meter to 3 meters, making construction, transportation and maintenance easier and cheaper. The relative thickness of the insulation layers 108 and 110 is selected to achieve a predetermined temperature T 3 , and the total thickness (and conductivity) of the first insulating layer 108 and the second insulating layer 110 is selected to provide a predetermined amount of leakage / vaporization rate (or no leakage / vaporization rate).

[0059] As the second insulating layer 110 extends from the outer surface 128 of the first insulating layer 108 to the inner surface 124 of the outer shell 106, the temperature rises until the temperature reaches the fourth temperature T 4 The fourth temperature is at the third temperature T 3 The ambient temperature T around the outer surface 126 of the outer shell 106 6 Therefore, the fourth temperature T 4 The fourth temperature T may be about 80 Kelvin to about 320 Kelvin, such as about 100 Kelvin to about 315 Kelvin, such as about 200 Kelvin to about 310 Kelvin, such as about 250 Kelvin to about 310 Kelvin, such as about 273 Kelvin to about 310 Kelvin. In one example, the fourth temperature T 4 At ambient temperature T 6 The second insulating layer has a third thickness L 3 The third thickness L 3 As noted above.

[0060] As the outer shell 106 extends from the inner surface 124 to the outer surface 126, the temperature inside the outer shell 106 increases from the fourth temperature T 4 Rising to the fifth temperature T 5 . Fifth temperature T 5The ambient temperature T close to the environment around the outer shell 106 6 , such as about 250 Kelvin to about 315 Kelvin, such as about 265 Kelvin to about 310 Kelvin, such as about 273 Kelvin to about 305 Kelvin. The thickness of the outer shell 106 is the fourth thickness L 4 . The fourth thickness L 4 Less than the first thickness L of the inner shell 102 1 , because the inner shell 102 has a pressurized cavity 104 formed by the inner surface 122. The outer shell 106 provides general support and protection for the insulation layers 108, 110. However, it is contemplated that in some cases, where additional protection of the insulation and / or contents is desired, the thickness L 4 The fourth thickness L 4 It is about 10 mm to about 100 mm, such as about 10 mm to about 50 mm, such as about 10 mm to about 30 mm, such as about 14 mm to about 25 mm, such as about 15 mm to about 20 mm.

[0061] Figure 3B Illustrate the formation Figure 2 A close-up view of a portion of the wall of the liquid hydrogen storage container 200. Above the portion of the liquid hydrogen storage container 200 is a graph 350 illustrating a schematic diagram of the temperature of the liquid hydrogen storage container 200 at various points within the body of the liquid hydrogen storage container 200. The graph 350 is similar to the graph 350. Figure 3A 300 , but further includes a portion corresponding to the temperature gradient in the intermediate housing 210 . The temperature in the intermediate housing 210 is from the third temperature T 3 To the seventh temperature T 7 The seventh temperature can be related to the third temperature T 3 Substantially the same as or just above the third temperature T 3 , such as above the third temperature T 3 About 0 Kelvin to about 3 Kelvin.

[0062] The intermediate housing 210 has a fifth thickness L of about 10 mm to about 100 mm. 5 , such as about 10 mm to about 75 mm, such as about 10 mm to about 50 mm, such as about 15 mm to about 45 mm, such as about 20 mm to about 45 mm, such as about 20 mm to about 30 mm. The fifth thickness L 5 At the first thickness L 1 With the fourth thickness L 4 However, other thicknesses and / or relative thicknesses are also contemplated.

[0063] The embodiments described herein achieve better and more reliable devices for insulating liquid gas storage containers, such as liquid hydrogen storage containers. 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 or aerogels and reducing gas diffusion through the first insulating layer 108. Due to the use of a mixture of glass microspheres and perlite, the second insulating layer 110 can be a better thermal insulator than the first insulating layer 108, thereby improving the insulation capability compared to conventional insulation devices.

[0064] Some embodiments, which may be combined with other embodiments, utilize an additional intermediate or middle housing 210 (e.g., a membrane) between the first insulating layer 108 and the second insulating layer 110. The intermediate housing 210 may be an impermeable membrane that may flex to accommodate changes in the dimensions of the first insulating layer 108 or metal / metal alloy housing. The impermeable membrane may further reduce the possibility of cryopumping.

[0065] While the foregoing 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 of the present disclosure, the scope of which is determined by the claims that follow.

Claims

1. A liquid gas storage container, comprising: an inner shell forming a cavity; an outer shell, forming an insulating volume between the inner shell and the outer shell; a first insulating layer disposed in the insulating volume and surrounding the inner shell, the first insulating layer being formed of a closed-cell insulating material; and The second insulating layer is arranged in the insulating volume between the first insulating layer and the outer shell.

2. The liquid gas storage container of claim 1, wherein the inner shell comprises a cryogenic metal.

3. The liquid gas storage container of claim 2, wherein the cavity comprises greater than about 3,000 m 3 The volume.

4. The liquid gas storage container of claim 1, wherein the closed cell insulating material comprises a first gas, wherein the first gas comprises greater than 50% nitrogen.

5. The liquid gas storage container of claim 1, wherein the second insulating layer comprises a second gas, wherein the second gas comprises greater than 50% argon.

6. The liquid gas storage container of claim 1, wherein the closed cell insulating material comprises a closed cell foam.

7. The liquid gas storage container of claim 6, wherein the second insulating layer comprises a bulk filler material.

8. The liquid gas storage container of claim 7, wherein the bulk filler material comprises one or more of perlite, glass microspheres, or silica aerogel, or a mixture thereof.

9. The liquid gas storage container of claim 8, wherein the second insulating layer comprises a mixture of perlite and glass microspheres.

10. The liquid gas storage container of claim 9, wherein the mixture comprises about 60 wt% to about 99 wt% perlite and about 1 wt% to about 40 wt% glass microspheres.

11. A liquid gas storage container, comprising: an inner shell forming a cavity; an outer shell, forming an insulating volume between the inner shell and the outer shell; a first insulating layer disposed in the insulating volume and surrounding the inner shell, the first insulating layer being formed of a closed-cell insulating material; a second insulating layer, disposed in the insulating volume between the first insulating layer and the outer shell; and The film layer is arranged between the first insulating layer and the second insulating layer.

12. The liquid gas storage container of claim 11, wherein the film layer comprises one or more of aluminized Mylar, Mylar, polyurea, epoxy, water glass, or zero gel.

13. The liquid gas storage container of claim 11, wherein the closed cell insulating material comprises a closed cell foam.

14. The liquid gas storage container of claim 11, wherein the second insulating layer comprises a bulk filler material comprising one or more of perlite, glass microspheres, or silica aerogel, or a mixture thereof.

15. The liquid gas storage container of claim 14, wherein the second insulating layer comprises a mixture of perlite and glass microspheres, wherein the mixture comprises about 60 wt% to about 99 wt% perlite and about 1 wt% to about 40 wt% glass microspheres.

16. The liquid gas storage container of claim 11, wherein the first insulating layer has a thickness of about 0.1 meter to about 1.0 meter.

17. The liquid gas storage container of claim 11, further comprising one or more gas inputs and one or more pumps or compressors in fluid communication with the second insulation layer.

18. A liquid gas storage container, comprising: an inner shell forming a cavity; an outer shell, forming an insulating volume between the inner shell and the outer shell; a first insulating layer disposed in the insulating volume and surrounding the inner shell, the first insulating layer being formed of a closed-cell insulating material; and A gas is disposed in the insulating volume between the first insulating layer and the outer shell.

19. The liquid gas storage container of claim 18, wherein the gas comprises greater than 50% argon.

20. The liquid gas storage container of claim 18, wherein the gas comprises greater than 50% nitrogen.

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