Storage container for cryogenic liquid, watercraft with a corresponding storage container and method for storing a cryogenic liquid

Abstract

The invention relates to a storage container (100) for a cryogenic liquid, comprising a container interior (14), in which an outlet region (15) for the liquid is formed, wherein an outlet opening (16) for the liquid is arranged in the outlet region (15). According to the invention, the outlet region (15) is separated from the container interior (14) by a shielding wall (18), designed with at least sections that are non-perforated, forming liquid through-openings (17). From a separate space, an outlet line can be guided out vertically downwards or to the side. The invention also relates to a corresponding watercraft (50) and a corresponding method for storing liquid hydrogen.

Description

[0001] Description

[0002] Storage container for cryogenic liquid, vessel with corresponding storage container and method for storing a cryogenic liquid

[0003] The invention relates to a storage container for a cryogenic liquid, a watercraft with a corresponding storage container and a corresponding method for storing a cryogenic liquid.

[0004] background

[0005] As described in WO 2021 / 204419 A1 by the applicant, storage containers for liquid hydrogen, for example, can have a cylindrical geometry with a tubular base section and two curved lid sections that close the base section at the front. In maritime applications of such storage containers, movement of the liquid hydrogen in the storage container caused by sea waves must be expected. If the storage container is arranged horizontally or vertically, the inertia of the liquid hydrogen and the existing curvature of the storage container can lead to extensive sloshing of the liquid hydrogen at both its base section and the lid sections. This sloshing, also known as sloshing, can lead to various disadvantages, which are also explained below.

[0006] DE 102012 207 575 A1 discloses a method for supplying a pump with cryogenic liquid, as well as a device and a container for carrying out the method. To ensure a reliable supply to a pump, the container is pressurized for improved withdrawal.

[0007] A propellant tank proposed in US 2018 / 072436 A1 comprises a tank body that collects the propellant in a liquid state, and a holding container provided within the tank body and arranged at a predetermined distance from an inner wall of the tank body so that the propellant can be held in a liquid state when the interior of the tank body is in a low-gravity state. US 5,901,557 A discloses a container for storing a cryogenic fluid that has a passive thermodynamic venting system for effectively transferring heat in a reduced-gravity environment. The storage container is divided by a screen trap so that the heat exchanger of the venting system passes through a chamber containing only the liquid phase of the cryogenic fluid.A screen tunnel, a screen trap, and a vane assembly work together to separate the gas and liquid phases of the cryogenic fluid. The thermodynamic venting system includes a throttling device to reduce the temperature of the cryogenic fluid.

[0008] US 3,933,448 A discloses a surface tension device for use in a liquid collection reservoir. This device comprises a porous membrane that maintains a separation between gas and liquid, thereby isolating accumulated gas from the collected liquid, which is subsequently released free of entrained gases. It also comprises a porous baffle held spaced from the vessel wall and forming a liquid collection chamber separate from the liquid storage chamber, into which pure liquid is collected and subsequently withdrawn through an opening. The baffle is characterized by a ski shape. This ensures essentially complete collection of the available liquid from the reservoir.

[0009] Against this background, the present invention aims to improve the storage of cryogenic liquids such as liquid hydrogen, particularly on ships.

[0010] Disclosure of the invention

[0011] Against this background, a storage container for a cryogenic liquid, a watercraft with a corresponding storage container, and a corresponding method for storing a cryogenic liquid are proposed. Embodiments of the invention are each the subject of the dependent patent claims and the following description. The storage container for a cryogenic liquid proposed according to the invention has a container interior, from which a discharge area for the liquid is separated. A discharge opening for the liquid is formed in the discharge area. According to the invention, the discharge area is separated from the container interior by means of a shielding wall, while keeping liquid passages free, wherein the shielding wall is designed to be unperforated at least in sections.

[0012] The imperforate, and thus fluid-impermeable, design of the shielding wall can be achieved in particular by providing the shielding wall entirely or at least in the corresponding sections in the form of a flat material, in particular a sheet of suitable thickness, or by joining several flat materials, in particular several sheets. The joining can be effected in particular by welding. "Partially imperforate" is to be understood here in particular to mean that one or more partial surfaces of the shielding wall are imperforate. The shielding wall can be shaped in a suitable manner, in particular to increase its stability or by adapting it to a container shape.The shielding wall can be designed, at least in the aforementioned sections, to be non-sieve-shaped and / or without bores, slots, holes, or passages of any kind, all of which, as understood here, are to be considered "perforation." A "non-sieve-shaped" design, as understood here, is also to be present in particular if a corresponding wall is not designed in the form of a grid made of woven or connected wire- or rod-shaped material or with regularly arranged holes. In particular, the shielding wall can be designed to be imperforate and thus liquid-impermeable over more than 50%, 60%, 70%, 80%, or 90% of its (total) surface area.

[0013] The present invention differs in particular from disclosures such as DE 102012 207 575 A1, US 2018 / 072436 A1, US 5,901,557 A and US 3,933,448 A by providing the imperforate shielding wall, which on the one hand relate to other fields of technology and on the other hand necessarily require a perforated or sieve-shaped element for the respective proposed solutions. By providing an imperforate shielding wall, stability can be increased and, if necessary, the shielding wall can be used as a structural element. Furthermore, production is simplified and becomes more cost-effective. In embodiments of the present invention, the exhaust opening can be an inlet opening of an exhaust line that is led out of the storage container inside or outside the exhaust area, vertically downwards or in a lateral direction.In other embodiments of the present invention, the discharge opening may also be an outlet opening in a container wall in the discharge area. In this way, the present invention can be used in both horizontally and vertically arranged storage containers.

[0014] The present invention, in corresponding embodiments, makes it possible, in particular, to prevent a negative effect of the sloshing mentioned above, which consists in the fact that, in the case of sufficiently large sloshing movements, gas can enter the discharge opening and remain there (so-called entrainment). In this case, a purely liquid withdrawal of the cryogenic liquid is not possible. The present invention overcomes this disadvantage using simple means. While, according to the prior art, installations such as sheet piling or baffles in horizontal and / or radial design, for example in the manner of a honeycomb structure, are typically provided throughout the entire interior of a corresponding container to prevent sloshing movements, the present invention enables the mitigation of these negative effects using simpler technical means.

[0015] Another prior art solution for preventing entrainment is the use of a sealed wall surrounding the discharge opening and having a certain height. However, this has the disadvantage that a certain liquid level is always required in a corresponding container (higher than the wall height), thus making complete drainage impossible. The present invention also overcomes this disadvantage.

[0016] A "cryogenic liquid" is understood to mean, in particular, a liquefied gas with a boiling point (significantly) below -100 °C, for example, liquefied noble gas, liquefied hydrogen, liquefied oxygen, liquefied methane, or natural gas. Therefore, although described primarily with reference to liquid hydrogen, the invention is not limited thereto. However, its suitability, in particular, for liquid hydrogen results from its low density of only approximately 70 kg / m³. 3, compared for example with 1,000 kg / m 3 for water, which makes it particularly easy to set in motion.

[0017] Overall, the invention prevents gas entrainment through the liquid discharge and enables optimized use of the entire interior space of a corresponding storage vessel. Compared to internals known from the prior art, the solution provided according to embodiments of the present invention is more space-saving and lightweight. Only local two-phase states, which could lead to disadvantages in downstream process steps or equipment, need to be avoided. As mentioned, an unperforated wall offers manufacturing, stability, and cost advantages.

[0018] In one embodiment of the invention, the storage container has a cylindrical section, wherein the shielding wall is provided in at least part of the cylindrical section. In this case, the discharge region can be separated from the container interior as a cylinder segment by means of the shielding wall. The shielding wall can contact the cylindrical section on two parallel sides. On these sides, the shielding wall, which can be flat or curved, can be connected, in particular welded, to the wall of the cylindrical section. In this way, it can be ensured that liquid in the region separated from the shielding wall, i.e. a corresponding cylinder segment, does not "slosh" along with the rest of the liquid in the container. As a result, the separated region remains filled with liquid, so that no gas can enter the discharge opening.By appropriate welding and selection of the thickness of the shielding wall, the latter can also have a structural or

[0019] Form a reinforcing element of the storage tank as a whole.

[0020] If, in a corresponding embodiment, an outlet opening or removal opening is provided in the extraction area and this is designed in the form of a cylinder segment, it can be provided, in particular, in a region of an apex line of the cylinder segment. If reference is made here to an arrangement of the outlet opening "in a region of an apex line of the cylinder segment," this is to be understood that the outlet opening does not have to be arranged directly on or at the apex line, but can also be offset from it in a specific area. In any case, however, the outlet opening is located within the separate cylinder segment.

[0021] The separation of a cylinder segment from a cylindrical portion of the storage tank can be provided, particularly in a horizontal arrangement. In a vertical design, a curved tank bottom can be separated according to the same principle. In both cases, the advantages of the invention arise essentially in the same way.

[0022] In one embodiment of the invention, particularly when a cylinder segment is separated from a cylindrical section, it is provided in particular that the shielding wall is connected to a container wall of the storage container by means of several fastening walls arranged parallel to one another. In the case of the cylindrical section and a separation of a cylinder segment, the fastening walls can in particular be arranged perpendicular to its central axis and connected to the container wall in the cylinder segment. The fastening walls can in particular be designed in the manner of bulkheads with suitable passages that chamber the extraction area and allow fluid exchange between the chambers.

[0023] In one embodiment of the invention, it can be provided, in particular, that the fastening walls are designed in the form of incomplete circular segments, which, in particular, define chambers arranged one behind the other along the central axis of the discharge area and leave passages between the chambers. In the case of the division of a cylinder segment in the manner explained above, these fastening walls can, in particular, leave alternating passages on the first and second of the two sides arranged parallel to the central axis between the chambers. Due to the alternating passages on both sides, the liquid can be distributed between the formed chambers, but is retained overall in the discharge area.

[0024] In one embodiment of the invention, the fastening walls define an at least partially meandering interior of the discharge area. The meandering design of the interior, according to the embodiment just explained, ensures the retention of liquid in the cylinder segment or a differently shaped discharge area in a particularly effective manner.

[0025] In one embodiment of the invention, the storage container is sealed at both ends by hemispherical or dome-shaped sections, as is generally known for corresponding tanks. The negative effects of sloshing movements that can occur at certain ends can also be reliably prevented in embodiments of the invention.

[0026] In one embodiment of the invention, it is provided that the storage container has a double wall which is designed for vacuum insulation.

[0027] A watercraft having a storage tank, as previously explained in various configurations, is also subject to the present invention. The cylindrical section can be arranged horizontally or vertically. The discharge opening can be directed vertically downwards or laterally. For further features and advantages, express reference is made to the above explanations regarding the storage tank and its configurations, as these relate to a corresponding watercraft in the same way.

[0028] The same applies to a method for storing liquid hydrogen, in which a storage container as previously explained in embodiments is used, in particular in a corresponding watercraft.

[0029] The invention and embodiments thereof are explained in more detail below with reference to the accompanying drawings.

[0030] Short description of the drawings

[0031] Figure 1 illustrates a watercraft according to an embodiment of the invention.

[0032] Figures 2A and 2B illustrate a storage container according to one embodiment of the invention in a schematic longitudinal view. Figures 3A and 3B illustrate a storage container according to one embodiment of the invention in a schematic perspective view.

[0033] In the figures, structurally and / or functionally corresponding components are indicated with identical reference symbols and are not explained repeatedly for the sake of clarity.

[0034] Detailed description of the drawings

[0035] Figure 1 shows a simplified schematic representation of a watercraft according to an embodiment of the present invention, designated overall by 50. In particular, the watercraft 50 may be a maritime passenger ferry.

[0036] The watercraft 50 comprises a hull 51 that is capable of floating. A bridge 52 is optionally provided on or on the hull 51. The watercraft 50 is preferably powered by hydrogen. For this purpose, the watercraft 50 can have a fuel cell 53. A "fuel cell" in the present case is understood to mean a galvanic cell that converts the chemical reaction energy of a continuously supplied fuel, in this case hydrogen, and an oxidizing agent, in this case oxygen, into electrical energy. The electrical energy obtained can be used, for example, to drive an electric motor (not shown), which in turn drives a ship's propeller to propel the watercraft 50.

[0037] To supply the fuel cell 53 with hydrogen, a storage tank 100 for storing liquid hydrogen is provided. The storage tank 100 is rotationally symmetrical to a central or symmetry axis 54 of the watercraft 50. To illustrate different alternatives, the storage tank 100 is oriented vertically in Figure 1, but horizontally in the subsequent figures. The storage tank 100 can be arranged, for example, within the hull 51, in particular within an engine room, on the bridge 52, or on a deck of the hull 51 acting as a foundation 55. The axis of symmetry 54 is oriented, in particular, perpendicular to a direction of gravity g. This means that the storage tank 100 is positioned horizontally or horizontally. In maritime applications, movement of the liquid hydrogen contained in the storage tank 100 caused by sea conditions must be expected.This sloshing, also known as sloshing, leads to the disadvantages mentioned above, especially the entrainment mentioned above.

[0038] In Figures 2A and 2B, a storage container according to an embodiment of the invention is shown transparently in longitudinal and cross-sectional views, designated overall by 100. A longitudinal axis of the storage container 100 is arranged parallel to the plane of the paper and parallel to the writing direction. In the views of Figures 2A and 2B, the storage container 100 is shown rotated by 90° about the longitudinal axis.

[0039] In the example illustrated here, the storage tank 100 has a double wall formed by an inner wall 11 and an outer wall 12. An intermediate space 13 between the inner wall 11 and the outer wall 12 can, for example, be evacuated. The double wall surrounds a tank interior 14, with a discharge area 15 for liquid separated from the tank interior 14. A discharge opening 16 for the liquid is arranged in the discharge area 15. In the example illustrated here, the discharge opening 16 represents an inlet opening into a discharge line 17 leading out of the storage tank 100.

[0040] As illustrated here, the discharge area 15 is separated from the container interior by a shielding wall 18, forming fluid passages. The shielding wall is imperforate. In the specifically illustrated example, the storage container 100 has a cylindrical section 110, wherein the shielding wall 18 is provided in at least a part of the cylindrical section 110, here in its central region, by means of which a cylinder segment corresponding to the discharge area 15 is separated.

[0041] In the embodiment of the present invention illustrated here, the shielding wall 18 contacts the inner wall 11 of the storage container at two sides 18a, 18b arranged parallel to a central axis of the cylindrical section 110 (as illustrated in Figure 2A), and is here, in particular, welded to it. At the front and rear, the cylinder segment or the discharge area 15 is connected to a remainder of the container interior 14 via corresponding connecting openings 19.

[0042] As illustrated in Figure 2A, the shielding wall 15 is connected to the inner wall 11 of the storage container by means of a plurality of fastening walls 20 arranged parallel to one another, wherein the fastening walls 20, in the concrete example illustrated here, are designed in the form of incomplete circular segments, define chambers arranged in the discharge region 15 and alternately leave passages on the first and the second of the two sides arranged parallel to the central axis between the chambers and in this way define an at least partially meander-shaped interior of the cylinder segment 5.

[0043] The storage tank as a whole is closed at both ends by hemispherical or dome-shaped sections 120.

[0044] Figures 3A and 3B illustrate a storage container 100 according to an embodiment of the invention in a schematic perspective view, with the storage container 100 being shown in transverse section in Figure 3A and in longitudinal section in Figure 3B. Reference is made to the explanations for Figures 2A and 2B.

Claims

Patent claims 1. Storage container (100) for a cryogenic liquid, comprising a container interior (14) in which a venting area (15) for the liquid is formed, wherein a venting opening (16) for the liquid is arranged in the venting area (15), characterized in that the venting area (15) is separated from the container interior (14) by means of a shielding wall (18) which is at least partially unperforated, while keeping liquid passages (17) free.

2. Storage container (100) according to claim 1, wherein the vent opening (16) is an inlet opening of a vent line (17) for the liquid, the vent line (17) being led vertically downwards or to the side out of the storage container (100) inside or outside the vent area (15).

3. Storage container (100) according to claim 2, wherein the extraction opening (16) is an outlet opening from the storage container (100) in the extraction area.

4. Storage container (100) according to one of the preceding claims, comprising a cylindrical section (110), wherein the shielding wall (15) is provided in at least a part of the cylindrical section (1), and wherein the extraction area (15) is separated from the interior of the container (14) by means of the shielding wall (15) as a cylindrical segment (5).

5. Storage container (100) according to claim 14, wherein the shielding wall (18) contacts the cylindrical section (110) on two parallel sides.

6. Storage container (100) according to one of the preceding claims, wherein the shielding wall (18) is connected to a container wall (11 , 12) of the storage container (100) by means of several parallel mounting walls (20).

7. Storage container (100) according to claim 6, wherein the mounting walls (20) are formed in the form of incomplete circular segments, arranged one behind the other The storage container (100) defines arranged chambers and leaves passages between the chambers. A storage container (100) according to claim 6 or claim 7, wherein the mounting walls (20) define an at least partially meandering interior of the extraction area 15. A storage container (100) according to any one of the preceding claims, which is closed at both ends by hemispherical or dome-shaped sections (120). A storage container (100) according to any one of the preceding claims, which has a double wall (11, 12) configured for vacuum insulation. A watercraft (50) comprising a storage container (100) according to any one of the preceding claims, wherein the cylindrical section (1) of the storage container (100) is arranged horizontally or vertically. A method for storing a cryogenic liquid, wherein a storage container (100) according to any one of claims 1 to 10, in particular in a watercraft (50) according to claim 11, is used.

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