Cryopumping-resistant LH2 storage container

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 of related applications This application claims priority to U.S. Provisional Patent Application No. 63 / 522,652, filed on 22 June 2023, which is incorporated herein by reference in its entirety.

[0002] Embodiments of this disclosure generally relate to cryogenic containers for storing liquid hydrogen. [Background technology]

[0003] Hydrogen is an alternative energy source to conventional fossil fuels. For example, some modes of transport, such as automobiles, are powered by hydrogen fuel cells. Hydrogen is also being used in other industrial applications, such as the Haber-Bosch process for producing fertilizer. As the demand for hydrogen increases, and partly due to the development and consumer adoption of more efficient hydrogen-powered vehicles and machinery, 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 extremely cold, which puts stress on its container. For example, the boiling point of liquefied hydrogen gas at one atmosphere is approximately -253°C (20°K). Therefore, liquid hydrogen is usually stored under conditions close to ambient pressure and a temperature of approximately 20 Kelvin.

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

[0006] Liquid hydrogen is cold enough to condense and freeze component gases in the air, such as nitrogen or oxygen, in the presence of liquid hydrogen, such as in the walls of a container containing it. The condensation and freezing of atmospheric gases transfer heat to the liquid hydrogen, causing it to evaporate. The evaporated hydrogen gas may need to be vented, which results in a loss. As a result, some liquid hydrogen containment containers include vacuum insulation to avoid the heat load caused by the condensation or freezing of atmospheric gases.

[0007] Conventional liquid hydrogen storage containers are formed from double-walled steel containers with vacuum insulation. The inner steel container wall, which stores the liquid hydrogen, is suspended from the outer steel container wall. Insulation material is placed between the two container walls in a vacuum. In all insulation materials, the exhaust of air prevents convective heat transfer and also prevents heat transfer that would occur if the gas in the insulated space liquefied against the colder inner container, resulting in a decrease in the insulation effect.

[0008] The size of the outer steel vessel walls of liquid hydrogen storage containers is limited because the steel walls tend to buckle due to the vacuum load on the vacuum insulation material. Therefore, the outer vessel must be designed to withstand the pressure difference caused 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 containers, but designing an outer vacuum container for very large storage containers 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 damage the foam, and ice formation on the outer surface. This behavior is unacceptable for multiple refill cycles or long-term storage.

[0010] Therefore, what is needed in this field is a cost-effective method for insulating large liquid hydrogen gas storage containers. [Overview of the project]

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

[0013] To gain a more detailed understanding of the above features, a more specific explanation, briefly summarized above, can be obtained by referring to exemplary embodiments, some of which are shown in the accompanying drawings. However, it should be noted that the accompanying drawings only show typical exemplary embodiments and should not be considered limiting in scope. [Brief explanation of the drawing]

[0014] [Figure 1] This is a schematic cross-sectional side view of a first liquid hydrogen storage vessel according to an embodiment described herein. [Figure 2] This is a schematic cross-sectional side view of a second liquid hydrogen storage vessel according to an embodiment described herein. [Figure 3A] This is a schematic cross-sectional side view of an exemplary liquid hydrogen storage vessel according to an embodiment described herein. [Figure 3B]It is a schematic cross-sectional side view of an exemplary liquid hydrogen storage container according to the embodiments described in this specification. [Figure 3C] It is a schematic cross-sectional side view of an exemplary liquid hydrogen storage container according to the embodiments described in this specification. [Figure 4A] It is an enlarged view of a part of the wall forming the liquid hydrogen storage container according to the embodiments described in this specification. [Figure 4B] It is an enlarged view of a part of the wall forming the liquid hydrogen storage container according to the embodiments described in this specification. [Figure 5] It is an enlarged view of a part of the heat insulation base according to the embodiments described in this specification.

Mode for Carrying Out the Invention

[0015] For ease of understanding, where possible, the same reference numerals are used to indicate the same elements common to the drawings. The elements and features of one embodiment can be beneficially incorporated into other embodiments without further enumeration.

[0016] This disclosure relates in general to cryogenic vessels for storing liquid hydrogen. This disclosure provides a cryogenic vessel that enables the use of thinner walls while maintaining efficient cryogenic storage, thereby reducing the cost of the cryogenic vessel. The cryogenic vessel may include an inner shell placed on an insulating base, the insulating base enabling the cryogenic vessel to implement a flat surface. The insulating base may include a first insulating sublayer, a planarizing layer, and a second insulating sublayer, thereby providing a stable flat surface on which the inner shell is mounted while reducing thermal conductivity. The insulating base may be enclosed within a skirt and / or anchor straps that support the weight of the inner shell, thereby reducing the complexity of foam compression and / or thermal conductivity. The skirt may be fixed to the base, thereby preventing movement of the inner shell within the cryogenic vessel. Advantageously, by fixing the inner vessel via the skirt and / or anchor straps, it is possible to prevent the inner shell from rising within the cryogenic vessel due to the internal pressure of hydrogen acting on the inner shell.

[0017] The outer insulation layer is filled with gas to maintain a pressure in the adiabatic space near 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. If the inner vessel shrinks due to low-temperature liquid hydrogen products or if the gas condenses, additional gas is supplied to the outer insulation layer to prevent a pressure drop. 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 inner vessel temperature. At least one embodiment utilizes a low thermal conductivity gas, such as nitrogen or argon, in the adiabatic space, such as the inner insulation layer and / or the outer insulation layer.

[0018] The heat insulation layer structure described in this specification can be used for any application that stores or transports cryogenic liquids such as pipes. For example, the heat insulation layer structure described in this specification can store higher temperature liquids such as liquid helium or liquid natural gas. Although a spherical liquid gas storage container is shown, the heat insulation layer, film, and shell structure described in this specification can also be used for cylindrical storage containers or storage containers of other shapes.

[0019] When liquid hydrogen products have to be stored at pressures significantly exceeding ambient pressure, the simplest shape is a sphere, but non-spherical pressure vessel shapes (generally having a rounded shape) are also possible. If the liquid hydrogen products can be stored in or near another shaped ambient pressure vessel such as a cylinder, it can be used. The insulation space can have a consistent thickness throughout to reduce fluctuations in the interface temperature.

[0020] FIG. 1 shows a schematic cross-sectional side view of a liquid hydrogen storage container 100. The liquid hydrogen storage container 100 includes an inner shell 102 that forms a cavity 1*04. The cavity 104 is formed by the inner surface 122 of the inner shell 102. The cavity 104 is configured to hold liquid hydrogen or another liquid gas. The cavity 104 can have a volume greater than 3,000 m 3 greater, for example 4,000 m 3 greater, for example 5,000 m 3 greater, for example 6,000 m 3 greater, for example 6,500 m 3 greater, for example 7,000 m 3 greater, for example about 10,000 m 3 greater, for example about 50,000 m 3 greater, for example about 75,000 m 3 greater, for example about 100,000 m 3 greater, for example about 150,000 m 3 greater, for example about 200,000 m 3 and can have a greater volume. In some embodiments, the volume is from about 5,000 m 3 to about 250,000 m3 , or more than that, for example, about 100,000 m 3 ~About 200,000m 3 The inner shell 102 is formed of a cryogenic metallic material such as cryogenic steel or another cryogenic metallic alloy that can be used 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 side walls, a domed top surface, and a flat bottom surface. In some embodiments, the cylindrical inner shell may include rounded corners. Although not bound by theory, rounded corners can reduce stress concentration compared to sharp corners, and rounded corners can reduce adiabatic stress cracking.

[0021] The inner shell 102 is placed on an insulating base 130. The insulating base may include a first insulating sublayer 132. The first insulating sublayer 132 may include closed-cell foam, open-cell foam, or any other load-bearing insulating material. The first insulating sublayer 132 may include an insulating coating, such as aerogel, placed on the first insulating sublayer 132 so that the insulating coating is in contact with the interior of the inner shell 102. Although not bound by theory, the insulating coating may improve the low-temperature adsorption of gas molecules that were 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 can support pressures from approximately 800 kPa to approximately 2,400 kPa. The first insulating sublayer 132 is maintained under vacuum at pressures of approximately 1 mTorr to approximately 1,000 mTorr, for example, approximately 100 mTorr to approximately 900 mTorr, approximately 100 mTorr to approximately 800 mTorr, or approximately 500 mTorr to approximately 700 mTorr. The first insulating sublayer 132 includes thicknesses of approximately 50 mm to approximately 1,000 mm, for example, approximately 50 mm to approximately 800 mm, approximately 100 mm to approximately 700 mm, or approximately 200 mm to approximately 500 mm. The first insulating sublayer 132 may have a coefficient of thermal expansion similar to that of the inner shell 102 material, and the first insulating sublayer 132 can contract and / or expand at a similar rate to that of the inner shell 102. While not bound by theory, the first adiabatic sublayer 132, when combined with a vacuum, 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 placed on the planar layer 134. The planar layer 134 comprises cement material and / or metal material. The planar layer 134 includes thicknesses of approximately 0 mm to approximately 200 mm, for example, approximately 10 mm to approximately 150 mm, approximately 50 mm to approximately 150 mm, or approximately 50 mm to approximately 100 mm. Although not bound by theory, the planar layer 134 can provide a uniform and / or flat surface for placing the first insulating sublayer 132, thereby allowing the inner shell 102 to rest on a flat surface.

[0024] The planarization layer 134 is positioned on the second insulating sublayer 136. The planarization layer 134 may include an insulating material such as metal, aerogel, and / or concrete. Although not bound by theory, the planarization layer 134 may provide protection for the second insulating sublayer 136, as described later, to prevent heat from penetrating or coming into contact with the second insulating sublayer 136. For example, the planarization layer 134 may include concrete to prevent heat from interacting with the second insulating sublayer 136 while the first insulating sublayer 132 is being welded and / or formed.

[0025] The second insulating sublayer 136 may include closed-cell foam and / or open-cell foam. The second insulating sublayer 136 is a load-bearing foam and can support pressures of approximately 800 kPa to approximately 2,400 kPa. The second insulating sublayer 136 may have thicknesses of approximately 200 mm to approximately 5,000 mm, for example, approximately 200 mm to approximately 4,000 mm, approximately 500 mm to approximately 3,000 mm, or approximately 1,000 mm to approximately 2,000 mm. The second insulating sublayer 136 may be filled with gas, for example, hydrogen, nitrogen, argon, helium, or a combination thereof. The second insulating sublayer 136 can be maintained at atmospheric pressure. Although not bound by theory, the second insulating sublayer 136 can further insulate the insulating base 130, thereby improving the cold storage efficiency of the cryogenic container.

[0026] Optionally, an interleaved layer can be placed between the first insulating sublayer 132 and the second insulating sublayer 136. The interleaved layer may include composites, cement, metal, polymer, foam, or a combination thereof. The interleaved layer may have a thickness of approximately 0 mm to approximately 200 mm, for example, approximately 10 mm to approximately 150 mm, approximately 50 mm to approximately 150 mm, or approximately 50 mm to approximately 100 mm. Although not bound by theory, the interleaved layer may stop crack formation by preventing crack propagation throughout the insulating base 130 and increase the strength of the first insulating sublayer 132 and / or the second insulating sublayer 136.

[0027] Optionally, the interleaved layer may include a foam layer. The foam layer may be placed on and / or above the second insulating sublayer 136 to form a braided layer, for example, a layer of collapsed foam bubbles. Although not bound by theory, the braided layer may reduce permeability due to the increased foam density, thereby reducing cryogenic pumping and increasing cryogenic cooling capacity.

[0028] The skirt 138 is positioned along the side wall 140 of the insulated base 130. The skirt can support the body of the inner shell 102 and the insulation material supported by the inner shell 102. The skirt 138 includes a metallic material. The skirt 138 includes thicknesses of about 5 mm to about 50 mm, for example, about 5 mm to about 40 mm, about 10 mm to about 40 mm, or about 20 mm to about 30 mm. Although not bound by theory, the skirt 138 can provide structural support to the insulated 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. One or more anchors 144 may be embedded in the top surface 146 of the base 142. Additionally or alternatively, anchors 144 may extend from the top surface 146 to the skirt 138 (not shown). The base may include cement material and / or metallic material. The base 142 may include one or more heating elements 150. While not bound by theory, one or more heating elements 150 can reduce and / or prevent freezing of materials placed beneath the base 142, thereby preventing damage to the base 142.

[0029] One or more anchors 144 can be used to attach the skirt 138 to the base 142 so that the inner shell 102 does not move and / or shift within the liquid hydrogen storage container 100, thereby preventing the thermal insulation space from being compromised. One or more anchors 144 may include fasteners, straps, bolts, nuts, rivets, or a combination thereof. One or more anchors may include cryogenic steel, stainless steel, and / or a combination thereof. One or more anchors 144 may extend along the length of the skirt 138 and / or be positioned along the top surface 146 of the base 142. Although not bound by theory, securing the skirt 138 to the base 142 via anchors 144 positioned along the top surface 146 of the base 142 can prevent the inner shell 102 from lifting away from the thermal insulation base 130 after seismic acceleration and / or internal pressure loads.

[0030] An outer shell 106 is formed around an inner shell 102 and a 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 positioned 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 so that the inner shell 102 and the skirt 138 are sealed. 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 outer surface 120, and the chemical bonding may include forming a bond using epoxy bonds and / or forming a bond through a reaction between the first insulation layer 108 and the outer 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 having thin polymer films arranged in a polyhedral shape, for example, approximately 0.01 mm to 1.0 mm, approximately 0.01 mm to 0.5 mm, approximately 0.05 mm to 0.1 mm, or approximately 0.07 mm to 0.1 mm. The cells are filled with a gas, such as a blowing agent, which is used to expand the cells within the foam. For example, the blowing agent may include unsaturated organic compounds such as hydrofluoroolefins. At room temperature, atmospheric gases such as nitrogen may diffuse into the cells, where the blowing agent may also diffuse.

[0032] When the outer surface 120 of the inner shell is cooled, the gas in the cells of the first insulating layer 108 proximal to the outer surface 120 and / or skirt 138 is also cooled. The gas can liquefy and / or solidify. When the gas liquefies and / or solidifies, the pressure in the cells decreases, creating a pressure difference across the cell walls of the closed-cell foam. The pressure difference can be about 0.01 atm to about 1 atm, for example, about 0.01 atm to about 0.5 atm, about 0.01 atm to about 0.1 atm, or about 0.01 atm to about 0.05 atm. If the cell walls of the closed-cell foam are gas permeable, the 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 outer surface 120 is heated during maintenance or other processes, the liquefied gas and / or solidified gas may vaporize, potentially causing the cell to rupture.

[0033] To prevent damage, the closed-cell foam can be cooled to cryogenic temperatures, thereby reducing and / or preventing the diffusion of gas into the cells of the closed-cell foam due to reduced permeability of the closed-cell foam. Although not bound by theory, reducing the permeability of the closed-cell foam reduces the likelihood of rupture when the closed-cell foam is heated. Furthermore, although not bound by theory, the first insulation layer 108 can reduce the complexity of damage to the thermal insulation performance when heating the inner shell 102.

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

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

[0036] The second insulation layer 110 is also located within the insulation space 105. The second insulation layer 110 is located between the first insulation layer 108 and the outer shell 106. The second insulation layer 110 is located 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 that of the first insulation layer 108. The second insulation layer 110 may be formed from bulk materials, such as gas, foam, glass fiber, aerogel, expanded perlite, glass microspheres, an insulating material having low thermal conductivity, and / or a combination thereof. For example, the second insulation layer 110 may contain gas. As a further example, the second insulation layer 110 may contain a mixture of glass fiber, glass microspheres, and perlite. As a further example, the second insulating layer 110 may include expanded perlite. The glass microspheres may have diameters of approximately 1 nm to 100 μm, for example, approximately 1 nm to 10 μm, approximately 500 nm to 10 μm, or approximately 500 nm to 1 μm. The second insulating layer 110 may also be a closed-cell foam. Although not bound by theory, a second insulating layer 110 containing a mixture of glass fibers, glass microspheres, and perlite can prevent the movement of glass microspheres and perlite within the insulating layer, as the glass fibers constrain and / or hold the glass microspheres and / or perlite in place.

[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 1% to about 99% by weight of perlite and about 1% to about 99% by weight of glass microspheres. For example, the mixture may include about 60% to about 99% by weight of perlite and about 1% to about 40% by weight of glass microspheres. As a further example, the mixture may include about 80% to about 99% by weight of perlite and about 1% to about 20% by weight of glass microspheres. The mixture may have flow permeability of approximately 6 darcy to approximately 45 darcy, for example, approximately 6 darcy to approximately 40 darcy, approximately 6 darcy to approximately 30 darcy, approximately 6 darcy to approximately 20 darcy, or approximately 10 darcy to approximately 20 darcy. Although not bound by theory, a second insulating layer having a flow permeability of approximately 6 darcy to approximately 40 darcy can reduce runaway cryopumping, thereby increasing the thermal insulation efficiency 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 more than 50% nitrogen, more than 50% argon, or more than 50% nitrogen and argon combination, as measured by partial pressure. In some embodiments, the combination of second gases may be more than 60% of one or a combination of nitrogen and argon, e.g., more than 70% of one or a combination of nitrogen and argon, e.g., more than 80% of one or a combination of nitrogen and argon, e.g., more than 90% of one or a combination of 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 can be used. The nitrogen and / or argon gas may be used in the second insulation layer 110 during its formation 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 because hydrogen and helium have higher conductivity compared to nitrogen and argon.

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

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

[0042] Optionally, an interleaved layer can be placed between the first insulation layer 108 and the second insulation layer 110. The interleaved layer may include composite materials, cement, metal, polymer, foam, or a combination thereof. The interleaved layer may have a thickness of approximately 0 mm to approximately 200 mm, for example, approximately 10 mm to approximately 150 mm, approximately 50 mm to approximately 150 mm, or approximately 50 mm to approximately 100 mm. Although not 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 entire insulation space 105.

[0043] Optionally, the interleaved layer may include a foam layer. The foam layer may be placed on and / or above the second insulation layer 110 to form a braided structure, for example, a layer of collapsed foam bubbles. Although not bound by theory, the braided structure may reduce permeability due to the 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 extending into the cavity 104 to fill or drain liquid hydrogen into the cavity 104. The conduit 112 is positioned such that its open end is inside the cavity 104 and its other end is connected to a hydrogen source 114 outside the body of the liquid hydrogen storage container 100. The hydrogen source 114 may include a pump or condenser, as well as one or more supply lines to various other hydrogen sources. Although only a single conduit is shown, it should be understood that there may be two or more conduits, such as a conduit for filling, a conduit for drawing, a conduit for passing boil-off gas, and optionally other conduits. In some examples, filling and evaporation may pass through a conduit that passes through the top, and the drawer line may pass through the top or bottom. Other configurations are also possible.

[0045] Figure 2 shows a schematic cross-sectional side view of another liquid hydrogen storage container 200. The liquid hydrogen storage container 200 includes an intermediate shell 210. The intermediate shell 210 may be an impermeable membrane, such as a metal or a nonmetal, depending on the embodiment and the type of insulation used 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 can 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 it, but the intermediate shell 210 can still bend 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 of about 50 Kelvin to about 100 Kelvin, e.g., about 60 Kelvin to about 90 Kelvin, e.g., about 70 Kelvin to about 90 Kelvin, e.g., about 75 Kelvin to about 85 Kelvin. The intermediate shell 210 is at least partially impermeable because its permeability coefficient is low enough to provide a given level of impermeability for use in a storage container. Although not 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 where the intermediate shell 210 is an impermeable film, the film 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 also possible but are not expressly listed herein. The film is subjected to a pressure of 400 kg / mm² at a temperature of about 77 Kelvin. 2 exceeding, for example, 500 kg / mm 2 exceeding, for example, 600 kg / mm 2 For example, exceeding 700 kg / mm 2The membrane can have an elastic modulus exceeding 108. The elastic modulus allows the membrane to bend together with the first insulation layer 108 and the 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 to seal the first insulation layer 108 from the second insulation layer 110. Therefore, if there are gaps or cracks in the first insulation layer 108, the presence of the membrane can reduce or eliminate the effect of cryogenic pumping. The use of the intermediate shell 210, which is a flexible membrane, may further allow the use of additional materials, such as open-cell foam, as part of the first insulation layer 108.

[0048] Optionally, sealant is also placed around any openings within 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 a support skirt 118 passes through the intermediate shell 210. The sealant may include an epoxy resin such as LOCTITE® Stycast 2850. The sealant may also 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 a skirt, piping, 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 to the first insulating layer. While not bound by theory, welding a collar with a film to a skirt, piping, and / or support that penetrates the first insulating layer can enhance the cryogenic cooling capacity of a cryogenic vessel.

[0050] The intermediate shell 210, also called an interlayer, is placed between the first insulating layer 108 and the second insulating layer 110. In such examples, the intermediate shell 210 may be a metal, a 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 foams and aerogel blankets may be examples of self-supporting materials that can be used for the first insulation layer 108. The insulating material of the first insulation layer 108 may have a compressive strength of about 14 psi to about 100 psi, for example, 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 permeate the impermeable membrane from both differential pressure and any forces exerted by the granular material used for insulating the second insulation layer 110.

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

[0053] As shown in Figure 3A, the second insulating sublayer 136 can extend along the base 142 such that the inner shell 102 and outer shell 106 are positioned 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 one or more anchors.

[0054] A protective layer 302 is provided on the first insulating sublayer 132. The protective layer 302 may include a metal layer, a cement layer, a polymer layer, and / or other suitable materials to protect the first insulating sublayer 132 from heat. Although not bound by theory, the protective layer 302 can protect the first insulating sublayer 132 from heat during the manufacturing of the inner shell 102, thereby preventing cracking and / or deformation during manufacturing.

[0055] As shown in Figure 3B, the first insulating sublayer 132 can be positioned on the second insulating sublayer 136, and the first insulating sublayer 132 is in contact with 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 as described herein. Although not bound by theory, positioning the first insulating sublayer along the skirt 138 and the sidewall of the second insulating sublayer may reduce the gap between the skirt and the first insulating sublayer. Furthermore, although not bound by theory, a reduction in cracks at the bottom corner of the inner shell 102 may occur.

[0056] As shown in Figure 3C, the second insulating sublayer 136 can extend along the base 142 such that the inner shell 102 is positioned on the second insulating sublayer 136. The second insulating sublayer 136 can be exposed to the first insulating layer 108, and the skirt 138 terminates at the upper surface 310 of the second insulating sublayer 136. The first insulating sublayer 132 may include the insulation of the first insulating layer 108 as described herein. Although not bound by theory, a reduction in heat leakage occurs due to the skirt terminating at the upper surface of the second insulating sublayer.

[0057] Figure 4A shows a magnified view of a portion of the wall forming the liquid hydrogen storage container 100 in Figure 1. Above the portion of the liquid hydrogen storage container 100 is a graph 400 showing 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. Graph 400 includes a vertical axis 402 showing temperature (T) and a horizontal axis 404 showing the position within the liquid hydrogen storage container 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 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 rises to a second temperature T2 in the inner shell 102. The second temperature T2 may be quite similar to the first temperature T1, such as about 20 Kelvin to about 25 Kelvin, or about 20 Kelvin to about 22 Kelvin. In some examples, the inference between the first temperature T1 and the second temperature T2 is less than 2 Kelvin, e.g., less than 1 Kelvin, e.g., less than 0.5 Kelvin. The second temperature T2 can be directly related to the first thickness L1 of the inner shell 102. The first thickness L1 is approximately 10mm to 100mm, for example, approximately 10mm to 75mm, for example, approximately 10mm to 50mm, for example, approximately 15mm to 45mm, for example, approximately 20mm to 45mm, for example, approximately 20mm to 30mm.

[0059] The temperature rises from a second temperature T2 to a third temperature T3 via 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 less than about 20 Kelvin, less than about 10 Kelvin, for example less than about 5 Kelvin above the condensation point of the gas in the second insulating layer 110. If the gas in the second insulating layer 110 is nitrogen, the third temperature T3 is greater than 77 Kelvin, for example about 78 Kelvin to about 80 Kelvin, for example about 78 Kelvin to about 90 Kelvin, for example about 78 Kelvin to about 100 Kelvin. In other examples, the third temperature T3 may be higher, such as 150K to 170K, to further reduce the possibility of condensation.

[0060] To reach temperatures exceeding 77 Kelvin, the first insulation layer 108 has a thickness L2 of approximately 0.1 m to 1 m, for example, approximately 0.55 m to 0.75 m, for example, approximately 1 m to 1.5 m, for example, approximately 1.1 m to 1.4 m, for example, approximately 1.2 m to 1.3 m. The combined total thickness of both insulation layers is in the range of approximately 0.2 m to 5 m, for example, 1 m to 3 m, resulting in easier and cheaper construction, transportation, and maintenance. The relative thickness of the insulation layers is 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 is selected to provide (or lack thereof) a predetermined amount of leakage / boil-off rate.

[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, its temperature rises until it reaches a fourth temperature T4. The fourth temperature lies between the third temperature T3 and the ambient temperature T6 surrounding the outer surface 126 of the outer shell 106. Therefore, the fourth temperature T4 may be approximately 80 Kelvin to approximately 320 Kelvin, for example, approximately 100 Kelvin to approximately 315 Kelvin, for example, approximately 200 Kelvin to approximately 310 Kelvin, for example, approximately 250 Kelvin to approximately 310 Kelvin, for example, approximately 273 Kelvin to approximately 310 Kelvin. In one example, the fourth temperature T4 is within approximately 2 to 5 Kelvin of the ambient temperature T6. The second insulation layer has a third thickness L3, which is as described above.

[0062] As the outer shell 106 extends from the inner surface 124 to the outer surface 126, the temperature inside the outer shell 106 rises 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 approximately 250 Kelvin to approximately 315 Kelvin, approximately 265 Kelvin to approximately 310 Kelvin, and approximately 273 Kelvin to approximately 305 Kelvin. The thickness of the outer shell 106 is a fourth thickness L4. The fourth thickness L4 is smaller 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 allows for overall support and protection of the insulating layer. However, in some situations where additional protection of the insulating material and / or contents is desired, the thickness L4 can be made larger. The fourth thickness L4 is approximately 10mm to 100mm, for example, approximately 10mm to 50mm, for example, approximately 10mm to 30mm, for example, approximately 14mm to 25mm, for example, approximately 15mm to 20mm.

[0063] Figure 4B shows an enlarged view of a portion of the wall forming the liquid hydrogen storage container 200 in Figure 2. Above the portion of the liquid hydrogen storage container 200 is Graph 450, which shows 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. Graph 450 is similar to Graph 400 in Figure 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 it may be slightly higher than the third temperature T3, for example, about 0 Kelvin to about 3 Kelvin above the third temperature T3.

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

[0065] The embodiments described herein enable better and more reliable devices for insulated 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 insulation layer 108 by using closed cells that reduce gas diffusion through the first insulation layer 108. The second insulation layer 110 can be made insulated by using a mixture of glass microspheres and perlite, thereby increasing the insulation capacity compared to conventional insulation devices. Although the disclosure shows 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 insulation layer 108 and the second insulation layer 110. The intermediate shell 210 may be an impermeable membrane that can flex to accommodate changes in the dimensions of the first insulation layer 108 or the metal / metal alloy shell. The impermeable membrane can further reduce the possibility of cryopumping.

[0067] Figure 5 shows an enlarged view of a portion of the insulating base 130 of the liquid hydrogen storage container. Above the portion of the liquid hydrogen storage container is a graph 500 showing a schematic diagram of the temperature of the liquid hydrogen storage container at various points within the body of the liquid hydrogen storage container. Graph 500 includes a vertical axis 502 showing the height (x) inside the liquid hydrogen storage container relative to the center of the cavity and a horizontal axis 504 showing the 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 less than or equal to about 20 Kelvin while storing liquid hydrogen. The temperature rises from the first temperature T1 to a second temperature T8 through the first adiabatic sublayer 132. The second temperature T8 is higher than the condensation point of the gas in the second adiabatic sublayer 136, for example, higher than the condensation point of nitrogen or argon. The second temperature T8 may be less than about 10, for example less than about 5, higher than the condensation point of the gas in the second adiabatic sublayer 136. For example, the second temperature T8 is above 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. As a further example, to further reduce the possibility of condensation, the second temperature T8 may be as high as 150K to 170K. Optionally, if the thickness of the first adiabatic sublayer 132 is greater than the thickness of the second adiabatic sublayer 136, the second temperature T8 becomes the third temperature T 10 It can be approximately 90% to 100% of that.

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

[0070] The temperature may remain stable in the planarization layer 134. The planarization layer 134 has a second thickness D2 of approximately 0 mm to approximately 200 mm, for example, approximately 0 mm to approximately 180 mm, approximately 10 mm to approximately 150 mm, or approximately 20 mm to approximately 100 mm. The temperature may continue to rise until it reaches a third temperature T9. The third temperature is the second temperature T8 and, for example, the temperature surrounding the second insulating sublayer 136 in the base 142. 10 It is between these two ranges. Therefore, the third temperature T9 may be approximately 80 Kelvin to approximately 320 Kelvin, for example approximately 100 Kelvin to approximately 315 Kelvin, for example approximately 200 Kelvin to approximately 310 Kelvin, for example approximately 250 Kelvin to approximately 310 Kelvin. In one example, the third temperature T9 is temperature T 10 The temperature is within approximately 2-5 Kelvin. 10The temperature may be above freezing point and / or ambient temperature. The second insulating sublayer 136 has a third thickness D3. The third thickness D3 is approximately 200 mm to approximately 5000 mm, for example, approximately 200 mm to approximately 4000 mm, approximately 500 mm to approximately 3000 mm, or approximately 1000 mm to approximately 2000 mm.

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

[0072] Overall, this disclosure provides a cryogenic container that enables the use of thinner walls while maintaining efficient low-temperature storage, thereby reducing the cost of the cryogenic container. The cryogenic container may include an inner shell positioned on an insulating base, the insulating base enabling the cryogenic container to have a flat surface. The insulating base may include a first insulating sublayer, a planarizing layer, and a second insulating sublayer, thereby providing a stable, flat surface on which the inner shell rests while reducing thermal conductivity. The insulating base may be enclosed within a skirt that supports the weight of the inner shell, thereby reducing the complexity of foam compression and / or thermal conductivity. By fixing the skirt, movement of the inner shell within the cryogenic container can be prevented.

[0073] While the foregoing is directed toward embodiments of the present disclosure, other further embodiments of the present disclosure can be devised without departing from its basic scope, which is determined by the following claims.

Claims

1. A liquid gas storage container, An inner shell forming a cavity, wherein the inner shell is placed on an insulating base, and the insulating base includes a first insulating sublayer, An outer shell that forms an insulating space between the inner shell and the outer shell, Within the aforementioned insulated space, a first insulating layer is arranged 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, Includes, The first insulating layer comprises a closed-cell foam and is chemically bonded to the outer surface of the inner shell. The second insulating layer is a liquid gas storage container containing bulk filling material.

2. The liquid gas storage container according to claim 1, further comprising a skirt positioned along the side wall of the thermal insulation base.

3. The liquid gas storage container according to claim 2, wherein the first insulating layer is arranged around the skirt within the insulating space.

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

5. The liquid gas storage container according to claim 1, wherein the first insulating sublayer is maintained at a pressure of approximately 100 mTorr to approximately 1000 mTorr.

6. The liquid gas storage container according to claim 1, wherein the first insulating sublayer includes a load-bearing insulating body.

7. The liquid gas storage container according to claim 6, wherein the first insulating sublayer includes a load-bearing foam containing closed-cell foam.

8. Between the first insulating sublayer and the second insulating sublayer, or Between the first insulation layer and the second insulation layer, The liquid gas storage container according to claim 1, further comprising an interleaved layer arranged therein.

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

10. The liquid gas storage container according to claim 1, wherein the bulk filling material comprises one or more of gas, foam, glass fiber, aerogel, expanded perlite, glass microspheres, and an insulating material having low thermal conductivity.

11. The liquid gas storage container according to claim 10, wherein the second insulating layer comprises about 60% to about 99% by weight of perlite and about 1% to about 40% by weight of glass microspheres.

12. A liquid gas storage container, An inner shell forming a cavity, wherein the inner shell is placed on an insulating base, and the insulating base includes a first insulating sublayer, An outer shell that forms an insulating space between the inner shell and the outer shell, Within the aforementioned insulated space, a first insulating layer is arranged 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 film layer disposed between the first thermal insulation layer and the second thermal insulation layer, Includes, The first insulating layer comprises a closed-cell foam and is chemically bonded to the outer surface of the inner shell. The second insulating layer is a liquid gas storage container containing bulk filling material.

13. The liquid gas storage container according to claim 12, wherein the film layer comprises one or more of aluminized polyethylene terephthalate, polyethylene terephthalate, or epoxy.

14. The liquid gas storage container according to claim 12, further comprising a skirt positioned along the side wall of the insulating base, wherein the first insulating layer is positioned around the skirt within the insulating space.

15. The liquid gas storage container according to claim 14, further comprising one or more anchors mechanically coupled to the skirt.

16. The liquid gas storage container according to claim 15, wherein the first insulating sublayer includes a load-bearing insulating body.

17. The liquid gas storage container according to claim 16, wherein the first insulating sublayer includes a load-bearing foam containing closed-cell foam.

18. The liquid gas storage container according to claim 12, further comprising an interleaved layer disposed between the first insulating sublayer and the second insulating sublayer.

19. The liquid gas storage container according to claim 12, further comprising a protective layer disposed on the first insulating sublayer.

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