Storage container

Abstract

A storage container (1) for storing a cryogenic agent (H2) comprises an inner container (4) for containing the cryogenic agent (H2), an outer container (3) surrounding the inner container (4), and a heating device (14) for generating pressure inside the inner container (4) by introducing heat (Q) into the cryogenic agent (H2), the heating device (14) having a length compensator (35) set up to compensate for the change in length (Δl) of the inner container (4) due to heat.

Description

Technical Field

[0001] The present invention relates to a storage container for storing cryogenic agents.

[0002] According to the knowledge within a business establishment, a storage container for liquid hydrogen can have a heating device that enables generation of a predetermined pressure inside the storage container. Such a type of storage container is substantially cylindrical or drum-shaped and includes an inner container for containing hydrogen and an outer container surrounding the inner container. A vacuum chamber with a vacuum applied is provided between the inner container and the outer container.

[0003] The heating device is guided, for example for its replacement, from around the storage container, through such a vacuum chamber, and into the inner container. It must be possible to perform the expansion and assembly of the heating device without breaking the vacuum. Furthermore, the change in length of the inner container caused by heat should not lead to mechanical stress in the outer container, the inner container, and / or the heating device during the injection of the cryogenic agent into the inner container, which may be fixedly connected to the outer container.

[0004] Based on such a background, an object of the present invention is to provide an improved storage container.

[0005] Accordingly, a storage container for storing cryogenic agents is proposed. The storage container includes an inner container for containing the cryogenic agent, an outer container surrounding the inner container, and a heating device for generating pressure inside the inner container by introducing heat into the cryogenic agent. The heating device has a length compensator set up to compensate for the change in length of the inner container caused by heat.

[0006] By providing the length compensator, it is possible to compensate for the change in length of the inner container caused by heat, so that when the cryogenic agent is injected into the inner container, stress is not introduced into the heating device, the inner container, and / or the outer container due to the contraction of the inner container caused by heat.

[0007] In particular, the length compensator is set up to compensate for thermal changes in the length of the inner container along the longitudinal direction of the storage container. In addition, it can also compensate for radial changes in length of the storage container, although this is optional.

[0008] The refrigerant is preferably hydrogen. Therefore, the concepts of "refrigerant" and "hydrogen" can be interchanged at will. However, in principle, the refrigerant may be any other refrigerant. Examples of refrigerant liquid, refrigerant fluid or liquid, or simply refrigerant include, in addition to the hydrogen mentioned above, liquid helium, liquid nitrogen, or liquid oxygen. Thus, "refrigerant" is understood to be a liquid in particular. Therefore, the refrigerant can also be called a refrigerant liquid.

[0009] The cryogenic agent can vaporize and transition into the gas phase. After vaporization, the cryogenic agent becomes a gas, or can be called a gaseous or vaporized cryogenic agent. Thus, the concept of "cryogenic agent" can include both of these, that is, the gas phase and the liquid phase. As mentioned above, the liquid phase can also be called a cryogenic agent liquid. In this context, the concept of "vaporized cryogenic agent" specifically refers only to the gaseous phase of the cryogenic agent.

[0010] Within the storage container, particularly within the inner container of the storage container, a gaseous zone and a liquid zone located beneath it are formed after or when the refrigerant is injected into the storage container. A phase boundary is provided between the gaseous zone and the liquid zone. The heating device is positioned particularly, at least regionally, inside the inner container, especially in the liquid zone.

[0011] In other words, after being poured into a storage container, the refrigerant has two phases with different condensation states, namely liquid and gas. The liquid phase can transition to the gas phase, and vice versa. The liquid phase can be called the liquid phase. The gas phase can be called the gaseous phase. It is also possible to fill the storage container with pure liquid.

[0012] The pressure generated in the storage container is preferably about 3.5 bara. The pressure generated in the storage container is particularly constant. The storage container is suitable for supplying the gaseous or liquid phase of the cryogenic agent to the consumption unit at an appropriate supply pressure and temperature. The consumption unit may be a fuel cell. In this context, "fuel cell" is understood to mean a galvanic cell that converts the chemical reaction energy of a continuously supplied fuel, in this case hydrogen, and an oxidizer, in this case oxygen, into electrical energy.

[0013] The cryogenic agent is supplied to the consumption unit itself, particularly in gaseous form. That is, when the gas phase is supplied directly from the storage container, the cryogenic agent is completely vaporized or heated before reaching the consumption unit, or upstream of it. For example, the cryogenic agent is supplied to the consumption unit at a supply pressure of 1 to 2.5 bara and a temperature of +10°C to +25°C. However, the supply pressure may be up to 6 bara.

[0014] Preferably, the storage container is assigned an axis of symmetry or a central axis, with respect to which it is substantially rotationally symmetric. Thus, the storage container may have a circular or ring-shaped cross-section. However, it may also have an elliptical or oblong cross-section. The inner and outer containers are, in particular, similarly configured with respect to the central axis.

[0015] The inner and outer containers each include a tubular base section configured rotationally symmetrically with respect to a central axis. At the end faces, the inner and outer containers are fluid-tightly closed off by cover sections. The inner and outer containers are particularly fluid-tight. The inner and outer containers may be made from, for example, a metal material, particularly special steel. The inner container is entirely located inside the outer container; that is, the outer container completely surrounds the inner container.

[0016] The heating device may be guided to enter the inner container, starting from the periphery of the storage container, passing through the outer and inner containers, and particularly into the liquid zone of the inner container. To this end, the heating device can be guided, for example, to pass through the respective covering areas of the inner and outer containers. In particular, the heating device is positioned in the liquid zone below the phase boundary, so that the heating device is always surrounded by or washed by the liquid phase of the chiller.

[0017] The heating device is set up to directly introduce heat into the liquid phase of the cryogenic material. To introduce heat, the heating device preferably includes a heating unit comprising a heating element supported by a support member. The introduction of heat into the cryogenic material causes it to vaporize at least partially, thereby enabling pressure generation inside the storage container, particularly inside the inner container.

[0018] The storage container preferably has a pressure sensor for measuring the internal pressure of the inner container. This allows for monitoring the pressure inside the inner container.

[0019] The storage container preferably has a control device connected to a pressure sensor and a heating device. This allows for the possibility of controlling the pressure inside the inner container.

[0020] Preferably, the heating device is assigned an axis of symmetry or a central axis, and is configured substantially rotationally symmetric with respect to this axis. The heating device may be circular or cylindrical in cross-section. However, this does not preclude the heating device from being at least partially elliptical or oblong in cross-section. In particular, the heating device may have an elliptical cross-section.

[0021] When viewed with respect to gravity, the central axis of the heating device is positioned below the central axis of the storage container. Conversely, the central axis of the storage container is positioned above the central axis of the heating device with respect to gravity. The central axes of the heating device and the storage container are parallel to each other and spaced apart.

[0022] When a refrigerant is poured into the inner container, the inner container, which may be fixedly connected to the outer container, shrinks along its longitudinal direction due to heat. At this time, the longitudinal direction is parallel to the central axis of the storage container. Due to the shrinkage, the inner container moves relative to the outer container by an amount equal to the change in length. This change in length may be, for example, several millimeters. Such a change in length can be compensated for by a length compensator.

[0023] In this context, "compensate" is understood to mean that the length compensator is compressed or stretched so as to prevent heat-induced stress from being applied to the heating device, the inner container, or the outer container. Thus, the length compensator is expandable and contractible. In this context, "expandable and contractible" is understood to mean that the length compensator can be compressed or folded, or stretched or unfolded, at least regionally. Thus, the length compensator is elastically, and especially spring-elastically, deformable.

[0024] In one embodiment, the storage container further has a vacuum chamber provided between an inner container and an outer container, and the heating device has an outer sleeve that is guided through the vacuum chamber into the inner container, and the internal space of the heating device surrounded by the outer sleeve is fluidly separated from the vacuum chamber.

[0025] As described above, the inner container is completely surrounded or encapsulated by the outer container. A gap in the form of a vacuum chamber is provided between the inner and outer containers. The vacuum chamber is evacuated. "Vacuum" in this case refers to a pressure lower than 300 mbar, preferably 10 mbar. -3 Lower than, more preferably 10 -7It is understood that the pressure is lower than [a certain value]. In this way, the storage container is vacuum-insulated or vacuum-sealed. The outer sleeve is preferably guided into the inner container below the phase boundary, so that the outer sleeve is flushed around by the refrigerant. The outer sleeve is preferably tubular. Inside the outer sleeve is the heating unit of the heating device described above, which is set up to introduce heat into the refrigerant. The internal space surrounded by the outer sleeve is "fluidically" separated from the vacuum chamber, in this case in particular, is understood to mean that there is no fluid connection between the internal space of the heating device and the vacuum chamber. In other words, the internal space of the heating device surrounded by the outer sleeve is not fluidly connected to the vacuum chamber.

[0026] In another embodiment, the internal space is filled with a thermally conductive medium.

[0027] The thermally conductive medium may be a gas. Therefore, the concepts of "medium" and "gas" can be arbitrarily interchanged. The thermally conductive medium may be a liquid, or may contain a liquid. The thermally conductive medium may have a liquid phase, a solid phase, and a gas phase. The thermally conductive medium may be part of a heating device. The thermally conductive medium embodies the assurance of heat conduction between the heating unit of the heating device and the outer sleeve, and consequently between the heating unit and the liquid phase of the cryogenic agent. Suitable gases include, for example, inert gases. The thermally conductive medium or gas may be helium. In particular, the thermally conductive medium is selected so that no phase change of the thermally conductive medium occurs over the entire operating temperature range of the storage container. In particular, the thermally conductive medium is preferably non-freezing or does not freeze. Alternatively, a phase change of the thermally conductive medium may be intended when the heating device is in operation. This can be embodied by the appropriate selection of the thermally conductive medium. The filling pressure and thermally conductive medium are preferably selected such that there is a difference between the ambient pressure and the operating pressure of the storage container, under the minimum and maximum temperatures that may occur during the operation of the storage container. Such a difference, as described above, allows for reliable detection of potential non-sealing between the liquid zone and the internal space of the outer sleeve, between the vacuum chamber and the internal space of the outer sleeve, and / or between the surroundings and the internal space of the outer sleeve. In the case where the refrigerant is hydrogen, the thermally conductive medium is preferably helium. The use of helium as the thermally conductive medium ensures that the freezing of the thermally conductive medium is prevented when the storage container is operated with hydrogen. As the filling pressure of the internal space of the outer sleeve, any overpressure is selected, for example, to enable leak monitoring. As the filling pressure, a pressure between 1.1 and 200 bar, particularly between 5 and 10 bar, is preferably selected. Monitoring of the internal space in this way enables safety engineering leak monitoring to meet the requirements under the relevant regulations concerning the separation of electrical systems from process systems and from the surroundings.

[0028] In another embodiment, the outer sleeve is fixedly coupled to the inner container.

[0029] In particular, the outer sleeve is joined to the inner container in a material bonding manner. In a material bonding type of connection, the mating partners are joined by atomic or molecular forces. A material bonding type of connection is a non-removable connection and can only be separated by destroying the bonding means and / or the mating partner. For example, bonding can be achieved by adhesion, soldering, welding, or vulcanization. For example, the outer sleeve is soldered or welded into the inner container. As described above, the inner container has a base area joined by two cover areas on the end face side. The outer sleeve is fixedly joined in particular to one of these cover areas. The outer sleeve may be soldered or welded into one of the cover areas of the inner container.

[0030] In another embodiment, the outer sleeve is guided to pass through a length compensator.

[0031] The length compensator is particularly cylindrical or tubular. The length compensator may be configured to be rotationally symmetric with respect to the central axis of the heating device. The length compensator circumscribes or surrounds the outer sleeve on the outer circumference.

[0032] In another embodiment, the length compensator is fixedly coupled to the outer container, and the outer sleeve is fixedly coupled to the length compensator.

[0033] In particular, the length compensator is materially bonded to the outer container. As mentioned above, the outer container has base areas that are closed off at their end faces by cover areas. The length compensator is fixedly bonded to one of these cover areas. In particular, the length compensator may be soldered or welded to the outer container. The outer sleeve is also materially bonded to the length compensator. For example, the outer sleeve may be welded or soldered to the length compensator. Thus, the outer sleeve is directly bonded to the inner container and also indirectly or non-directly bonded to the outer container via the length compensator. That is, the length compensator is positioned between the outer sleeve and the outer container.

[0034] In another embodiment, the length compensator has a bellows section that is foldable and foldable along the longitudinal direction of the storage container for longitudinal length compensation.

[0035] In addition to the bellows section, the length compensator has a first coupling section that is coupled to the outer container and a second coupling section that is coupled to the outer sleeve of the heating device. The bellows section is located between these two coupling sections. The bellows section is specifically a corrugated bellows and can therefore be called so. The bellows section is expandable and contractible. The bellows section may be made from, for example, a metal material.

[0036] In another embodiment, the length compensator surrounds an internal space that is fluidly connected to the vacuum chamber.

[0037] In other words, the internal space of the length compensator is also loaded with the vacuum generated within the vacuum chamber. In this case, the statement that the internal space of the length compensator is "fluidically" connected to the vacuum chamber is understood to mean that the internal space of the length compensator is fluidly connected to the vacuum chamber.

[0038] In another embodiment, the heating device includes a heating unit for introducing heat into the chilling agent and a coupling piece, the heating unit and coupling piece being located inside an outer sleeve.

[0039] In particular, the heating unit has the support member described above, and the heating element described above is wound around it in the form of a heating wire. The heating unit is attached to the coupling piece, in particular, on the front side. The heating unit may be fixedly coupled to the coupling piece. The heating unit is positioned, in particular, entirely inside the inner container, in particular inside the liquid zone.

[0040] In another embodiment, the outer sleeve has a flange, the coupling piece has a flange, and the flanges of the outer sleeve and the flange of the coupling piece are joined to each other in a shape-joint manner.

[0041] A shape-joint connection is established by the interlocking or rearward engagement of at least two connecting partners. In this case, the flange of the outer sleeve and the flange of the connecting piece may be screwed to each other. The flange of the outer sleeve and the flange of the connecting piece will be fluid-tightly sealed to each other. For this purpose, for example, a so-called welded lip seal may be intended.

[0042] In another embodiment, the heating unit is entirely located inside the inner container, and the coupling piece is guided from the perimeter of the storage container through the vacuum chamber into the inner container.

[0043] The coupling piece includes the flange described above, which is provided on a rod-shaped or bar-shaped base section. On the opposite side of this flange, an end section is provided on the base section at the end side to support the heating unit. In this way, the coupling piece allows the heating unit to be inserted into the inner container.

[0044] In another embodiment, the outer sleeve has a periphery-protruding connection that is fluidly connected to the internal space, and the connection is fluid-tightly closed.

[0045] A thermally conductive medium, for example, can be injected into the internal space of the outer sleeve via the connection. The connection may have a suitable valve for this purpose. The connection can also be used to monitor the pressure in the internal space. For this purpose, the connection may be equipped with a sensor, particularly a pressure sensor. The connection may have a number of different sensors, such as a pressure sensor, a temperature sensor, an optical sensor, and a sensor suitable for detecting cryogens and / or thermally conductive mediums.

[0046] In another embodiment, the connecting piece is made of special steel, composite material, and / or plastic.

[0047] In particular, the bonding pieces are made from materials with low thermal conductivity. In addition, the bonding pieces have a long, elongated rod-like geometry. This reduces the thermal conductivity of the bonding pieces. For example, the bonding pieces are made from polytetrafluoroethylene (PTFE). As for the composite material, for example, fiber-reinforced plastic materials, especially epoxy resins, can be used. As for the reinforcing fibers, for example, glass fibers or plastic fibers can be used.

[0048] In another embodiment, the heating unit has connecting pipes and / or sensor pipes that are guided to pass through the coupling piece.

[0049] For example, a heating unit has two connecting pipes for the heating element. These connecting pipes are routed from the heating unit through the coupling piece and through the flange of the coupling piece to the periphery. The heating unit may have one or more temperature sensors. Each temperature sensor is assigned the sensor piping described above. The sensor piping is also routed from the heating unit through the coupling piece to the flange of the coupling piece and from there to the periphery.

[0050] In another embodiment, the connecting piece is rod-shaped.

[0051] In this context, "rod-shaped" is understood to mean a long, elongated geometry. For example, the connecting piece has a circular cross-section. The connecting piece may be hollow. In this case, the connecting piece is a rod with an annular cross-section.

[0052] Here, "one" does not necessarily mean limited to exactly one element. Rather, there may be, for example, two, three, or more elements. The other numbers used here are not meant to be understood as having to be strictly limited to the exact number of elements mentioned. Rather, numerical differences up or down are possible.

[0053] Other possible embodiments of the storage container include combinations of the constituent elements or embodiments described above or below with respect to the examples, which are not explicitly stated. Those skilled in the art may also add individual embodiments as improvements or supplements to each basic form of the storage container. [Brief explanation of the drawing]

[0054] Other advantageous embodiments of the storage container are subject to the dependent claims and the embodiments of the storage container described below. Next, preferred embodiments of the storage container will be described in detail with reference to the accompanying figures. [Figure 1] This is a schematic cross-sectional view showing an embodiment of a storage container. [Figure 2] This is a detailed view II of Figure 1. [Figure 3] Figure 1 is a schematic diagram showing an embodiment of a length compensator for a storage container. [Figure 4] Figure 1 is a schematic diagram showing an embodiment of a coupling piece for a storage container.

[0055] Unless otherwise specified, identical elements or elements with the same function are given the same symbol in the diagrams.

[0056] Figure 1 shows a schematic cross-sectional view of an embodiment of storage container 1. Figure 2 shows a detailed view II of Figure 1. Figures 1 and 2 will be described together below.

[0057] Storage container 1 can also be called a storage tank. Preferably, storage container 1 is suitable for storing liquid hydrogen H2 (boiling point 1 bara: 20.268 K = -252.882°C). Therefore, storage container 1 can also be called a hydrogen storage container or a hydrogen storage tank. However, storage container 1 can also be used for other cryogenic liquids. Examples of cryogenic fluids or cryogenic liquids, or simply examples of cryogenics, include liquid helium He (boiling point 1 bara: 4.222 K = -268.928°C), liquid nitrogen N2 (boiling point 1 bara: 77.35 K = -195.80°C), or liquid oxygen O2 (boiling point 1 bara: 90.18 K = -182.97°C), in addition to the liquid hydrogen H2 mentioned above.

[0058] Storage container 1 is suitable for use inside or on the surface of a vehicle (not shown). The vehicle may be, for example, a marine vehicle, particularly a ship. The vehicle may also be called a marine vehicle. In particular, the vehicle may be a marine passenger ship. Alternatively, the vehicle may be a land vehicle. However, in the following, it is assumed that the vehicle is a marine vehicle.

[0059] The storage container 1 is constructed to be rotationally symmetric with respect to an axis of symmetry or central axis 2. The central axis 2 may be perpendicular to the direction of gravity g. That is, the storage container 1 is positioned horizontally or in a horizontal orientation. Alternatively, the central axis 2 may be parallel to the direction of gravity g. That is, the storage container 1 may be positioned vertically or in a vertical orientation. The longitudinal direction of the storage container 1 is aligned with the central axis 2. In the orientation of Figure 1, the longitudinal direction L extends from left to right.

[0060] The storage container 1 includes an outer container 3 configured rotationally symmetric with respect to a central axis and an inner container 4 configured rotationally symmetric with respect to a central axis 2. Here, the inner container 4 is entirely located inside the outer container 3. The outer container 3 and / or the inner container 4 may be made of, for example, special steel.

[0061] A vacuum chamber 5, at least partially a gap, is provided between the outer container 3 and the inner container 4. Within the vacuum chamber 5, a negative pressure is generated compared to the surrounding area 6 of the storage container 1. The surrounding area 6 can also be called the atmosphere. In other words, the concepts of "surrounding area" and "atmosphere" can be arbitrarily interchanged.

[0062] A barrier or insulating member may be provided within the vacuum chamber 5, filling at least partially or entirely the vacuum chamber 5. The insulating member may have, or be configured as, a multilayer insulating layer (MLI). Such a multilayer insulating layer may include multiple alternating layers or layers consisting of perforated and / or embossed aluminum foil as reflectors and glass paper as spacers between adjacent aluminum foils. The glass paper may be perforated and / or punctured.

[0063] The outer container 3 includes a tubular or cylindrical base region 7 configured rotationally symmetric with respect to a central axis 2. The base region 7 is closed on both sides at its end faces by cover regions 8, although only one of these cover regions 8 is shown in Figure 1. The base region 7 may have a circular or approximately circular geometry when viewed in cross-section. The cover regions 8 are curved. The cover regions 8 are each curved in opposite directions, so that the cover regions 8 curve outward with respect to the base region 7. The outer container 3 is fluid-tight, and in particular, airtight.

[0064] The inner container 4, like the outer container 3, includes a tubular or cylindrical base area 9 configured rotationally symmetric with respect to the central axis 2. The base area 9 is closed on both sides at its end faces by cover areas 10, although only one of these cover areas 10 is shown in Figure 1. The base area 9 can have a circular or approximately circular geometry when viewed in cross-section. The cover areas 10 are curved. The cover areas 10 are curved in opposite directions, so that they curve outward with respect to the base area 9. The inner container 4 is fluid-tight, and in particular, airtight.

[0065] Liquid hydrogen H2 is contained within the inner container 4. Within the inner container 4, there may be a gaseous zone 11 where the hydrogen H2 is vaporized and a liquid zone 12 where the hydrogen H2 is liquid, as long as the hydrogen H2 is in a two-phase region. In other words, after being injected into the inner container 4, the hydrogen H2 has two phases with different condensation states, namely liquid and gas. That is, there is a phase boundary 13 between the liquid hydrogen H2 and the gaseous hydrogen H2 within the inner container 4.

[0066] The storage container 1 includes a heating device 14. The heating device 14 is partially shown in Figure 2. The heating device 14 is set up to introduce heat Q into liquid hydrogen H2. The heating device 14 is electrically operated. Therefore, the heating device 14 can also be called an electric heating device or heater, or more specifically, an electric heater.

[0067] The heating device 14 enters the inner container 4 from the surrounding area 6 through the cover areas 8 and 10, and particularly into the liquid zone 12. The portion of the heating device 14 that enters the inner container 4 is preferably washed by the liquid hydrogen H2 in the liquid zone 12.

[0068] The following technical challenges must be overcome in order to assemble the heating device 14: Electrical conductors cannot be assembled into the vacuum chamber 5 because the low thermal conductivity inside the vacuum chamber 5 poses a risk of overheating of the electrical conductors. The electronics of the heating device 14 cannot be assembled into the vacuum chamber 5 because there is also a risk of overheating in that case.

[0069] The insertion of the heating device 14 reduces the insulating effect on the inner container 4, negatively impacting its insulation. This can lead to even higher heat injection from the surroundings 6 into the inner container 4. Gas rolls may form between the low-temperature inner container 4 and the high-temperature surroundings 6, potentially causing convection.

[0070] In cases where the inner container 4 and the outer container 3 are fixedly connected to each other, it is desirable that the change in length between the inner container 4 and the outer container 3 due to heating or cooling of the inner container 4, or due to temperature changes in the surrounding environment 6, be compensated for. The heating device 14 should preferably be replaceable without breaking the vacuum. These challenges are resolved by the heating device 14.

[0071] The heating device 14 is configured to be rotationally symmetric with respect to the axis of symmetry or central axis 15. The central axis 15 may be oriented parallel to the central axis 2. Here, the central axis 15 is positioned below the central axis 2 when viewed with respect to the direction of gravity g. Furthermore, the heating device 14 is assigned a radial direction R. The radial direction R is perpendicular to the central axis 15 and oriented away from it.

[0072] The heating device 14 includes a fluid-tight outer sleeve 16. The outer sleeve 16 is tubular and can therefore also be called an outer tube. The outer sleeve 16 is preferably made of a metal material, and may preferably be made of special steel. It is preferable that the outer sleeve 16 be made of a material that conducts heat well.

[0073] The outer sleeve 16 is guided through both cover areas 8 and 10 into the liquid zone 12. That is, the outer sleeve 16 partially penetrates the surrounding area 6 and partially penetrates the inner container 4, in particular into the liquid zone 12. The outer sleeve 16 may be soldered or welded into the cover area 10 of the inner container 4. The outer sleeve 16 is not connected to the cover area 8 of the outer container 3. The outer sleeve 16 may be made from a copper alloy, aluminum alloy, glass, glass ceramic, or ceramic.

[0074] The outer sleeve 16 is configured to be rotationally symmetric with respect to the central axis 15. The outer sleeve 16 may be circular in cross-section. Alternatively, the outer sleeve 16 may be slightly elliptical or oblong in cross-section. The outer sleeve 16 is closed on its outer circumference. The outer sleeve 16 surrounds the internal space 17. The internal space 17 can be called the internal space of the outer sleeve 16 or the internal space of the heating device 14. The internal space 17 can also be called the heating internal space. The internal space 17 is filled with a thermally conductive medium. The thermally conductive medium is preferably a gas, particularly helium (He). The outer sleeve 16 is fluid-tight.

[0075] The outer sleeve 16 includes a tubular base region 18 configured to be rotationally symmetric with respect to the central axis 15. In addition to the base region 18, the outer sleeve 16 includes a flange 19 that protrudes into the surrounding area 6. Opposite the flange 19, the outer sleeve 16 has a cover region (not shown) that fluid-tightly closes the outer sleeve 16. This cover region is located inside the inner container 4.

[0076] Outside the outer container 3, the outer sleeve 16 has a connection 20 that can be sealed fluidly. The connection 20 allows, for example, the internal space 17 to be filled with helium He. Furthermore, the connection 20 can also be used for monitoring the heating device 14. For example, a pressure drop or pressure increase in the internal space 17 can be detected via the connection 20. The connection 20 is located around the perimeter 6 outside the storage container 1.

[0077] In addition to the outer sleeve 16, the heating device 14 has a tubular support member 21 that supports the wire-shaped heating element 22. The support member 21 can also be called a support tube. The support member 21 is preferably configured to be rotationally symmetric with respect to the central axis 15. The support member 21 is made from a material that conducts heat well. For example, the support member 21 is made from a metal material, particularly a copper alloy or an aluminum alloy. However, the support member 21 may also be made from glass, glass ceramic, or ceramic. The heating element 22 and the support member 21 together form the heating unit 23 of the heating device 14.

[0078] The support member 21 may be a single, or more specifically, a materially integrated, component. Here, "single" or "of a single component" means that the support member 21 is a single component, not made up of multiple sub-components or components combined together. "Materially integrated" in this case specifically means that the support member 21 is consistently made from the same material. Alternatively, the support member 21 may be complex or multi-part. In this case, the support member 21 is made up of multiple sub-components or components.

[0079] The support member 21 extends in the longitudinal direction L so as to enter the inner container 4. In this case, it is preferable that the support member 21 is entirely located inside the inner container 4. The support member 21 is housed in the outer sleeve 16. In particular, the support member 21 is located in the internal space 17. It is preferable that the support member 21 is positioned concentrically with respect to the central axis 15, thereby providing a helium-filled gap 24 between the support member 21 and the base area 18, which completely encircles the support member 21.

[0080] The gap 24 can have a gap width of 0.5 to 1 millimeter. The gap width is selected to be as small as possible and as large as necessary so that the support member 21 can be inserted into the outer sleeve 16 together with the heating member 22. The gap 24 is part of the internal space 17. The gap 24 is optional. Alternatively, the support member 21 can be in contact with the outer sleeve 16 from the inside. This can improve heat transfer.

[0081] The cylindrical outer surface 25 of the support member 21 faces the outer sleeve 16. The gap 24 is provided between the outer surface 25 and the outer sleeve 16. The outer surface 25 is provided with a groove 26 that circulates around the support member 21 in a worm-like or spiral manner, housing the heating element 22. The heating element 22 is preferably a heating wire wound around the support member 21.

[0082] In cases where the support member 21 is made of a conductive material, the heating member 22 may have an electrical insulating portion that electrically insulates the heating member 22 from the support member 21. For example, the heating wire described above may be embedded in magnesium oxide powder encapsulated by a metal sleeve that does not conduct electricity, for example, a special steel sleeve. In this case, the concept of "heating member" can be understood accordingly as a heating wire insulated by metal or mineral. The groove 26 is optional. The heating member 22 may be wound around the support member 21 without the groove 26.

[0083] The cylindrical inner surface 27 of the support member 21 faces away from the outer surface 25. The inner surface 27 can be embodied by a hole guided to pass concentrically through the support member 21. The heating device 14 has at least one temperature sensor 28 equipped with a sensor pipe 29. The temperature sensor 28 can detect the temperature of the heating device 14. The temperature sensor 28 includes a mounting lug 30. As an alternative to the mounting lug 30, other types of mounting parts can be provided, for example, in the form of clamping, screwing, soldering, or inserting.

[0084] The temperature sensor 28 is held or mounted by a mounting member 31. The mounting member 31 is made from a material that conducts heat well, such as a copper alloy or an aluminum alloy. The mounting member 31 is tubular. The mounting member 31 is located inside the support member 21. For example, the mounting member 31 is pushed into the support member 21. The mounting member 31 may be a single, in particular, material-integrated component. Alternatively, the mounting member 31 may be composite or multi-part.

[0085] The mounting member 31 is configured to be rotationally symmetric with respect to the central axis 15. The mounting member 31 includes a cylindrical outer surface 32 that abuts against the inner surface 27 of the support member 21. Furthermore, the mounting member 31 includes a cylindrical inner surface 33, which is embodied, for example, by holes concentrically provided in the mounting member 31. In other words, helium He can flow through the mounting member 31.

[0086] Each temperature sensor 28 has a housing hole 34 in the mounting member 31 into which each temperature sensor 28 is inserted. The housing hole 34 is provided in the mounting member 31 at the end and extends into the mounting member 31 along the longitudinal direction. The housing hole 34 extends parallel to the central axis 15. The housing hole 34 may be a blind hole. When viewed along the radial direction R, the housing hole 34 is located just below the outer surface 32.

[0087] Furthermore, the heating device 14 includes a length compensator 35. Figure 3 shows a schematic diagram of an embodiment of such a length compensator 35.

[0088] The length compensator 35 enables length compensation along the longitudinal direction L. The length compensator 35 is configured to be rotationally symmetric with respect to the central axis 15. The outer sleeve 16 extends through the length compensator 35.

[0089] The length compensator 35 has a cylindrical first coupling area 36 that is fixedly coupled to the cover area 8 of the outer container 3. For example, the first coupling area 36 is soldered or welded into the cover area 8. In addition to the first coupling area 36, ​​a second coupling area 37 is provided. The second coupling area 37 includes a chamfer 38 that encircles the central axis 15. The chamfer 38 fixates the second coupling area 37 to the base area 18 of the outer sleeve 16, for example, by soldering or welding to it.

[0090] A bellows region 39 is positioned between the first coupling region 36 and the second coupling region 37. The bellows region 39 is compressible and stretchable along the longitudinal direction L to enable length compensation along the longitudinal direction L. The length compensator 35 is preferably an integral, particularly material-integrated, component. The length compensator 35 may be made of metal. The length compensator 35 surrounds the internal space 40 which is fluidly connected to the vacuum chamber 5.

[0091] Returning to Figure 1, the inner container 4, which is fixedly connected to the outer container 3 at the end region opposite to the cover region 10, contracts along the longitudinal direction L due to heat when liquid hydrogen H2 is injected. In Figure 1, the initial position of the cover region 10 before the inner container 4 is filled with liquid hydrogen H2 is shown by the dashed line and the label 10'.

[0092] When the inner container 4 is filled with liquid hydrogen H2, the cover area 10 moves to the right by a length change Δl in the orientation shown in Figure 1. The length change Δl may be, for example, several millimeters. Such a length change Δl can be compensated by the length compensator 35, and in particular by the bellows area 39. In this case, "compensate" is understood to mean that the bellows area 39 is compressed or stretched so as not to introduce thermal stress into the outer sleeve 16, the inner container 4, or the outer container 3.

[0093] Furthermore, the heating device 14 includes a coupling piece 41. Figure 4 shows a schematic diagram of an embodiment of this type of coupling piece 41.

[0094] The coupling piece 41 is housed within the outer sleeve 16. The coupling piece 41 includes a base section 42 extending along the longitudinal direction L. An end section 43 follows the base section 42. The end section 43 allows the coupling piece 41 to be coupled to the heating unit 23. In this way, the coupling piece 41 supports the heating unit 23.

[0095] On the side opposite to the end section 43, the connecting piece 41 has a flange 44. The flange 44 is connected to the flange 19 of the outer sleeve 16 by connecting members 45, 46 (Figure 1). The connecting members 45, 46 may be threaded. The connecting members 45, 46 allow the flanges 19, 44 to be easily connected to and disconnected from each other. A welded lip seal may be intended to seal the flanges 19, 44 to each other.

[0096] The sensor piping 29 and the connecting piping 47 and 48 of the heating element 22 are guided through the coupling piece 41. For this purpose, appropriate bushings 49, 50, and 51 are provided on the flange 44. The coupling piece 41 is preferably made of special steel. However, the coupling piece 41 may be made of plastic material.

[0097] Returning to Figure 1, the storage container 1 may be part of a cryogenic supply system 52 suitable for supplying gaseous hydrogen H2 to a consumption unit 53, which is preferably a fuel cell in this example, at a defined supply pressure and a defined supply temperature. For example, hydrogen H2 is supplied to the consumption unit 53 as a gas at a supply pressure of, for example, 1 to 2.5 bara and a temperature of, for example, 0 to +70°C, particularly +10 to +25°C. However, the supply pressure may be up to 6 bara.

[0098] The cryogenic supply system 52 can also be called a hydrogen supply system. In addition to the storage container 1, the cryogenic supply system 52 may have a vaporizer (not shown) suitable for vaporizing liquid hydrogen H2 and supplying it to the consumption unit 53.

[0099] The design of the heating device 14 allows for the maintenance of thermal insulation with the inner container 4 by using a material with low thermal conductivity between the surrounding 6 and the inner container 4. For example, the connecting piece 41 can be made from special steel or plastic material for this purpose. This allows the connecting pipes 47, 48 and the associated electronics to be separated from the vacuum chamber 5 by an additional barrier in the form of an outer sleeve 16 between the connecting pipes 47, 48 and the vacuum chamber 5.

[0100] The heat generated by resistance within the electrical connection pipes 47 and 48 is dissipated by selecting an appropriate material for the coupling piece 41 between the heating unit 23 and the flange 44. At this time, it must be ensured that, on the one hand, this material dissipates the heat generated within the connection pipes 47 and 48, and on the other hand, that the loss of cold air to the surroundings 6 is kept to a minimum.

[0101] Based on the potential for cold air loss, it is advantageous for the connecting piece 41 to be manufactured with a long extension to maintain as much insulation as possible. Special steel is suitable as the material for the connecting piece 41. Special steel leads to relatively low heat conduction to the outside, but this heat conduction is sufficient to dissipate heat from the electrical connection pipes 47 and 48. However, other materials with low thermal conductivity, such as plastic or ceramic, can also be used for the connecting piece 41.

[0102] For example, by filling the gap 24 with an insulating material in the form of mineral wool, it is possible to suppress the convection roll between the low-temperature inner container 4 and the high-temperature surroundings 6, and the associated cold air loss in the inner container 4.

[0103] The length compensator 35 enables compensation for length changes Δl that may occur between the inner container 4 and the outer container 3 due to different heating or cooling of the inner container 4 and the outer container 3. Compensation for length changes Δl can also be performed by an additional axial stop that can be integrated into the heating device 14.

[0104] The heating device 14 is designed to allow for easy replacement of the heating unit 23. For this purpose, flange couplings are intended between the respective flanges 19 and 44. Welded lip seals are applied to the flanges 19 and 44 to ensure 100% airtightness. However, other sealing methods are also possible.

[0105] Various thermally conductive media, such as helium (He), can be used to fill the gap 24 in the heating device 14. The size of the space between the heating device 14 and the vacuum chamber 5 is variable and can be adapted to the geometry of the heating device 14.

[0106] Various insulating materials can be used between the heating device 14 and the surrounding area 6. The outer sleeve 16 forms an independent space between the inner container 4 and the outer container 3. There is no fluid connection with the inner container 4. Various flange seals can be applied to the flanges 19 and 44.

[0107] Although the present invention has been described using examples, the present invention can be modified in various ways. [Explanation of Symbols]

[0108] 1. Storage container 2 center axis 3 Outer container 4 Inner container 5 Vacuum chamber 6 Surroundings 7 Base Area 8 Coverage Area 9 Base Area 10 Coverage Area 10' Coverage Area 11 Gas Zone 12 Liquid Zones 13 phase boundary 14 Heating device 15 Center axis 16 Outer sleeve 17 Interior space 18 Base Area 19 Flange 20 Connection part 21 Support member 22 Heating element 23 Heating Unit 24 Gap 25 Exterior 26 Groove 27 Inner self 28 Temperature Sensor 29 Sensor piping 30 mounting lugs 31 Mounting components 32 Exterior 33. Inner self 34 storage holes 35 Length Compensator 36 Combined area 37 Combined area 38 Chamfering 39 Bellows area 40 Interior space 41 connecting pieces 42 Base Area 43 End area 44 Flange 45 Connecting member 46 Connecting member 47 Connecting pipes 48 Connecting pipes 49 Bushing 50 Bushing 51 Bushing 52 Cryogenic supply system 53 Consumption Department g direction of gravity Helium / medium H2 Hydrogen / Cryogenic Agent L Longitudinal direction Q Heat R radial direction ΔI length change

Claims

1. A storage container (1) for storing a cryogenic agent (H2), comprising an inner container (4) for containing the cryogenic agent (H2), an outer container (3) surrounding the inner container (4), and a heating device (14) for generating pressure inside the inner container (4) by introducing heat (Q) into the cryogenic agent (H2), wherein the heating device (14) has a length compensator (35) set up to compensate for the change in length (Δl) of the inner container (4) caused by heat.

2. The storage container according to claim 1, further comprising a vacuum chamber (5) provided between the inner container (4) and the outer container (3), wherein the heating device (14) has an outer sleeve (16) that is guided through the vacuum chamber (5) into the inner container (4), and the internal space (17) of the heating device (14) surrounded by the outer sleeve (16) is fluidly separated from the vacuum chamber (5).

3. The storage container (1) according to claim 2, wherein the internal space (17) is filled with a thermally conductive medium (He).

4. The storage container according to claim 2 or 3, wherein the outer sleeve (16) is fixedly connected to the inner container (4).

5. The storage container according to any one of claims 2 to 4, wherein the outer sleeve (16) is guided to pass through the length compensator (35).

6. The storage container according to any one of claims 2 to 5, wherein the length compensator (35) is fixedly coupled to the outer container (3), and the outer sleeve (16) is fixedly coupled to the length compensator (35).

7. The storage container according to any one of claims 2 to 6, wherein the length compensator (35) has a bellows area (39) that is foldable and foldable along the longitudinal direction (L) of the storage container (1) for length compensation along the longitudinal direction (L).

8. The storage container according to any one of claims 2 to 7, wherein the length compensator (35) surrounds an internal space (40) that is fluidly connected to the vacuum chamber (5).

9. The storage container according to any one of claims 2 to 8, wherein the heating device (14) comprises a heating unit (23) for introducing heat (Q) into a chilling agent (H2) and a coupling piece (41), and the heating unit (23) and the coupling piece (41) are arranged inside the outer sleeve (16).

10. The storage container according to claim 9, wherein the outer sleeve (16) has a flange (19), the coupling piece (41) has a flange (44), and the flange (19) of the outer sleeve (16) and the flange (44) of the coupling piece (41) are joined to each other in a shape-joint manner.

11. The storage container according to claim 9 or 10, wherein the heating unit (23) is entirely located inside the inner container (4), and the coupling piece (41) is guided from the periphery (6) of the storage container (1) through the vacuum chamber (5) into the inner container (4).

12. The storage container according to any one of claims 9 to 11, wherein the outer sleeve (16) has a connecting portion (20) that is fluidly connected to the internal space (17) and protrudes into the surrounding area (6), and the connecting portion (20) is fluidly closed.

13. The storage container according to any one of claims 9 to 12, wherein the connecting piece (41) is made of special steel, composite material, and / or plastic.

14. The storage container according to any one of claims 9 to 13, wherein the heating unit (23) has connecting pipes (47, 48) and / or sensor pipes (29) guided to pass through the coupling piece (41).

15. The storage container according to any one of claims 9 to 14, wherein the connecting piece (41) is rod-shaped.

Images