STORAGE CONTAINER

Description

[0001] The invention relates to a storage container for liquid hydrogen according to the preamble of claim 1. Such a storage container is disclosed, for example, in WO 2008 / 036991A1.

[0002] According to the applicant's internal findings, storage vessels for liquid hydrogen have a cylindrical geometry with a tubular base section and two curved lid sections that close the base section at the front. Maritime applications of such storage vessels with sea conditions can lead to a reduction in the pressure of a gas cushion generated by the gas phase. This can have undesirable effects on the hydrogen supply pressure available for operating components, such as a fuel cell. This can lead to unstable operation of the operating components. This must be avoided.

[0003] Against this background, the object of the present invention is to provide an improved storage container for liquid hydrogen, particularly for maritime applications.

[0004] Accordingly, a storage container for liquid hydrogen is proposed. The storage container comprises a cylindrical wall which is constructed rotationally symmetrically to an axis of symmetry running along a direction of gravity, a base which closes the wall on one side at the end, a ceiling which closes the wall on one side at the end facing away from the base, and an intermediate wall arranged within the wall and at a distance from it. According to the invention, a gap is provided between a lower edge of the intermediate wall and the base so that an interior space enclosed by the intermediate wall is in fluid communication with an interior space enclosed by the wall, so that the liquid hydrogen can flow back and forth between the interior spaces. Furthermore, according to the invention, a gap circumferentially extending around the axis of symmetry is provided between the cylindrical wall and the intermediate wall.

[0005] Because the storage tank is arranged vertically and has this intermediate wall, the disadvantages described above can be avoided.

[0006] The storage container is particularly suitable for maritime applications. The storage container can therefore be referred to as a maritime storage container. For example, the storage container can be mounted on a vehicle, in particular on a watercraft. Accordingly, a vehicle, in particular a watercraft, with such a storage container is also proposed. The storage container can also be referred to as a storage tank, a hydrogen storage container or a hydrogen storage tank. The storage container is intended for holding liquid hydrogen. However, the storage container can also be used for other cryogenic liquids. Examples of cryogenic fluids or liquids, or cryogens for short, include liquid helium, liquid nitrogen or liquid oxygen.

[0007] After or during the filling of the hydrogen, a gas zone with gaseous hydrogen forms in the storage vessel, as does an underlying liquid zone with liquid hydrogen. A phase boundary is provided between the gas zone and the liquid zone. Thus, after being filled into the storage vessel, the hydrogen has two phases with different states of aggregation: liquid and gaseous. The hydrogen can transition from the liquid phase to the gaseous phase and vice versa. The partition wall extends at least partially into the liquid zone. Preferably, the partition wall is always at least partially surrounded by liquid hydrogen.

[0008] The wall is cylindrical, preferably circular-cylindrical. The partition wall also preferably has a circular-cylindrical geometry. The fact that the partition wall is "spaced" from the wall means, in this case, that there is no direct contact between the wall and the partition wall. In particular, the partition wall is positioned radially spaced from the wall. The partition wall is open or open at its front end, particularly when viewed toward the floor. This means that the term "enclosed" also encompasses embodiments in which the respective interior space is open or open toward the other interior space. With respect to a direction of gravity, the ceiling is positioned above the floor, in particular. This means that the storage container is positioned upright or vertically.

[0009] The fact that the axis of symmetry runs along the direction of gravity means that the axis of symmetry, and thus also the storage tank, are arranged vertically and not horizontally. This means that the ceiling is at the top with respect to the direction of gravity, and the floor is at the bottom and thus below the ceiling. The wall connects the ceiling to the floor. The ceiling and floor are curved outwards, particularly with respect to the wall.

[0010] According to a further embodiment, the partition wall is constructed rotationally symmetrically to the axis of symmetry. The partition wall thus extends around the axis of symmetry at a radial distance from the wall.

[0011] The gap extending around the axis of symmetry between the wall and the partition is preferably annular. The gap extends completely around the axis of symmetry. The gap is preferably gas-filled. The gap can also be at least partially liquid-filled. This means that the gap can be at least partially filled with liquid hydrogen and at least partially with gaseous hydrogen.

[0012] According to a further embodiment, the storage container comprises a plurality of intermediate walls constructed rotationally symmetrically to the axis of symmetry, wherein the intermediate walls are arranged coaxially to one another.

[0013] The number of partition walls is arbitrary. For example, two, three, or more partition walls are provided. The partition walls are preferably all cylindrical and have a rotationally symmetrical structure with respect to the common axis of symmetry. "Coaxial" means, in particular, that the partition walls share the same axis of symmetry.

[0014] According to a further embodiment, a gap extending around the axis of symmetry is provided between a first intermediate wall and a second intermediate wall arranged within the first intermediate wall.

[0015] The gap is preferably annular. The gap is, in particular, gas-filled. The gap can also be at least partially filled with liquid. A third partition wall and a fourth partition wall with corresponding gaps can also be provided.

[0016] According to a further embodiment, the partition wall is supported on the wall by means of supports.

[0017] The supports can be designed as struts and connect the partition wall to the wall of the storage tank. The second partition wall can also be supported directly on the wall, or the second partition wall can be supported on the first partition wall. The number of supports is optional. Preferably, at least three supports are provided, distributed evenly around the axis of symmetry.

[0018] The partition wall is arranged at a gap from the base, viewed along the axis of symmetry. This means that the partition wall is not connected to the base. The partition wall has, in particular, a lower edge that extends into the liquid hydrogen. In particular, the lower edge is arranged at a gap from the base.

[0019] According to a further embodiment, the partition wall is connected to the ceiling.

[0020] The storage container preferably comprises an outer container and an inner container accommodated in the outer container. The intermediate wall is, in particular, firmly connected to a ceiling section of the inner container, for example, welded or soldered thereto.

[0021] According to a further embodiment, the storage container further comprises an inner container for receiving the hydrogen and an outer container in which the inner container is received, wherein the intermediate wall extends along the axis of symmetry from the lid towards the bottom into the inner container.

[0022] An insulating element can be provided between the inner container and the outer container. The inner container and the outer container each have a tubular base section that is rotationally symmetrical to the axis of symmetry. The respective base section is connected to a ceiling section on one side at the front and to a floor section on the opposite side of the ceiling section. The respective ceiling sections form the ceiling of the storage container, and the respective floor sections form the floor of the storage container. The base sections form the wall of the storage container.

[0023] According to a further embodiment, the intermediate wall extends into the inner container at least along half of a length of the inner container.

[0024] This means that, viewed along the axis of symmetry, the partition wall has a length that is at least equal to or longer than half the length of the inner container. However, the previously mentioned gap is still provided between the lower edge of the partition wall and the bottom of the storage container.

[0025] According to a further embodiment, the floor and the ceiling are curved outwards and in opposite directions with respect to the wall.

[0026] This means that the floor and ceiling are curved away from the wall along the axis of symmetry. As previously mentioned, the floor comprises the floor sections of the inner and outer containers, and the ceiling comprises the ceiling sections of the inner and outer containers.

[0027] "One" in this case is not necessarily to be understood as limiting the number to exactly one element. Rather, multiple elements, such as two, three, or more, can also be considered. Any other counting term used here should also not be understood as requiring a precise limitation to the corresponding number of elements. Rather, numerical deviations upwards and downwards are possible.

[0028] Further possible implementations of the storage container also include combinations of features or embodiments described above or below with regard to the exemplary embodiments that are not explicitly mentioned. In this case, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the storage container. However, the invention is defined solely by the scope of the appended claims.

[0029] Further advantageous embodiments of the storage container are the subject of the dependent claims and the exemplary embodiments of the storage container described below. The storage container is explained in more detail below using preferred embodiments with reference to the accompanying figures. Fig. 1 shows a schematic side view of an embodiment of a vehicle; Fig. 2 shows a schematic sectional view of an embodiment of a storage container for the vehicle according to Fig. 1 ; and Fig. 3 shows a further schematic sectional view of the storage tank according to the section line III-III of the Fig. 2 .

[0030] In the figures, identical or functionally equivalent elements have been given the same reference numerals unless otherwise stated.

[0031] The Fig. 1shows a highly simplified schematic side view of an embodiment of a vehicle 1. The vehicle 1 can be, for example, a maritime watercraft, in particular a ship. The vehicle 1 can be referred to as a maritime vehicle. In particular, the vehicle 1 can be a maritime passenger ferry. Alternatively, the vehicle 1 can also be a land vehicle. However, it is assumed below that the vehicle 1 is a watercraft.

[0032] The vehicle 1 comprises a buoyant hull 2. A bridge 3 is provided on or on the hull 2. The vehicle 1 is preferably powered by hydrogen. For this purpose, the vehicle 1 can have a fuel cell 4. A "fuel cell" is understood here to be 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 resulting electrical energy can be used, for example, to drive an electric motor (not shown), which in turn drives a propeller to propel the vehicle 1.

[0033] To supply the fuel cell 4 with hydrogen, a storage tank 5 for storing liquid hydrogen is provided. The storage tank 5 is constructed rotationally symmetrically to a central or symmetry axis 6. The storage tank 5 can be arranged, for example, within the hull 2, in particular within an engine room, on the bridge 3, or on a deck of the hull 2 acting as a foundation 7. The axis of symmetry 6 is oriented along a direction of gravity g. This means that the storage tank 5 is positioned upright or vertically. Thus, the axis of symmetry 6 is placed perpendicular to the foundation 7. In the event that the vehicle 1 is, for example, a vehicle converted to a hydrogen drive, the storage tank 5 can also be placed, for example, in a chimney or chimney of the vehicle 1.

[0034] The Fig. 2shows a schematic sectional view of an embodiment of a storage container 5 as mentioned above. Fig. 3 shows a further schematic sectional view of the storage container 5 according to the section line III-III of Fig. 2 . The following refers to the Fig. 2 and 3 referred to at the same time.

[0035] The storage container 5 can also be referred to as a storage tank. As previously mentioned, the storage container 5 is suitable for holding liquid hydrogen H2 (boiling point at 1 bara: 20.268 K = -252.882 °C). Therefore, the storage container 5 can also be referred to as a hydrogen storage container or a hydrogen storage tank. However, the storage container 5 can also be used for other cryogenic liquids. Examples of cryogenic fluids or liquids, or cryogens for short, in addition to the aforementioned liquid hydrogen H2, include liquid helium He (boiling point at 1 bara: 4.222 K = -268.928 °C), liquid nitrogen N2 (boiling point at 1 bara: 77.35 K = -195.80 °C), or liquid oxygen O2 (boiling point at 1 bara: 90.18 K = -182.97 °C).

[0036] The storage container 5 is constructed rotationally symmetrically to the axis of symmetry 6. The storage container 5 comprises an outer container 8 constructed rotationally symmetrically to the axis of symmetry 6, and an inner container 9 constructed rotationally symmetrically to the axis of symmetry 6. The inner container 9 is arranged entirely within the outer container 8. An insulating element 10 is provided between the outer container 8 and the inner container 9. The insulating element 10 can comprise a multilayer insulation layer (MLI) or be designed as such.

[0037] The outer container 8 comprises a tubular or cylindrical base section 11, which is constructed rotationally symmetrically to the axis of symmetry 6. The base section 11 is closed on both sides by means of a cover section 12 and a base section 13. In the orientation of the Fig. 2Viewed along the direction of gravity g, the ceiling section 12 is arranged above the base section 13. The base section 11 can have a circular or approximately circular geometry in cross-section. The ceiling section 12 and the base section 13 are curved. The ceiling section 12 and the base section 13 are curved in opposite directions, so that the ceiling section 12 and the base section 13 are curved outward relative to the base section 11. The outer container 8 is fluid-tight, in particular gas-tight.

[0038] The inner container 9, like the outer container 8, comprises a tubular or cylindrical base section 14, which is constructed rotationally symmetrically to the axis of symmetry 6. The base section 14 is in the orientation of the Fig. 2closed at the top by a ceiling section 15 and at the bottom by a floor section 16. The base section 14 can have a circular or approximately circular geometry in cross-section. The ceiling section 15 and the floor section 16 are curved. In particular, the ceiling section 15 and the floor section 16 are curved in opposite directions, so that the ceiling section 15 and the floor section 16 are curved outward with respect to the base section 14. The inner container 9 is fluid-tight, in particular gas-tight. The outer container 8 and / or the inner container 9 can have a blow-off valve (not shown).

[0039] The two ceiling sections 12, 15, together with the insulating element 10 located between them, form a ceiling 17 of the storage container 5. The two floor sections 13, 16, together with the insulating element 10 located between them, form a floor 18 of the storage container 5, and the two base sections 11, 14, together with the insulating element 10 located between them, form a wall 19 of the storage container 5 that is rotationally symmetrical about the axis of symmetry 6. The wall 19 encloses an interior space 11 of the storage container 5.

[0040] The liquid hydrogen H2 is contained in the inner container 9 or in the interior space 11. As long as the hydrogen H2 is in the two-phase region, a gas zone 20 with vaporized hydrogen H2 and a liquid zone 21 with liquid hydrogen H2 can be provided in the inner container 9. Thus, after being filled into the inner container 9, the hydrogen H2 has two phases with different aggregate states, namely liquid and gaseous. This means that a phase boundary 22 is present in the inner container 9 between the liquid hydrogen H2 and the gaseous hydrogen H2.

[0041] The storage container 5 further has at least one intermediate wall 23 within the inner container 9. The intermediate wall 23 has a cylindrical, in particular a circular-cylindrical, geometry and is constructed rotationally symmetrically to the axis of symmetry 6. The intermediate wall 23 is connected to the ceiling 17 of the storage container 5, in particular to the ceiling section 15 of the inner container 9. For example, the intermediate wall 23 can be welded or soldered to the ceiling section 15. The intermediate wall 23 encloses an interior space I2, which is in fluid communication with the interior space I1. The interior space I2 is not closed, but is open or open towards the bottom 18. The interior spaces I1, I2 are thus in fluid communication with one another.

[0042] The intermediate wall 23 is constructed in particular concentrically to the wall 19 or to the base sections 11, 14 of the outer container 8 and the inner container 9. The intermediate wall 23 extends from the ceiling 17 along the direction of gravity towards the bottom 18. However, no connection is provided between the bottom 18 and the intermediate wall 23. A gap 25 is provided between a lower edge 24 of the intermediate wall 23 and the bottom 18. The intermediate wall 23 extends, viewed along the axis of symmetry 6, at least over half a length I of the inner container 9 into the inner container 9. The intermediate wall 23 protrudes at least partially into the liquid zone 21. This means that the intermediate wall 23 is at least partially surrounded by liquid hydrogen H2.

[0043] Several such partition walls 23 can be provided. For example, a first partition wall 23 and a second partition wall 26 are provided. The second partition wall 26 is also cylindrical and rotationally symmetrical to the axis of symmetry 6. The second partition wall 26 is arranged within the first partition wall 23. This means that the second partition wall 26, the first partition wall 23, and the wall 19 are arranged concentrically. The second partition wall 26 also ends at the lower edge 24.

[0044] The first partition wall 23 and / or the second partition wall 26 can be supported by supports 27, 28 relative to the wall 19 or the base section 14 of the inner container 9. The number of supports 27, 28 is arbitrary. For example, three such supports 27, 28 are provided, which are evenly distributed around the axis of symmetry 6.

[0045] Between the wall 19 and the first partition wall 23, a gap 29 is provided, which extends around the axis of symmetry 6. The gap 29 can be partially filled with liquid and partially with gaseous hydrogen H2. Between the first partition wall 23 and the second partition wall 26, a gap 30 is provided, which extends around the axis of symmetry 6. The gap 30 can also be partially filled with liquid and partially with gaseous hydrogen H2.

[0046] As the Fig. 3 As shown, the second intermediate wall 26 has a diameter d26 that is smaller than a diameter d23 of the first intermediate wall 23. The diameter d23, in turn, is smaller than a diameter d19, in particular an inner diameter, of the wall 19 or the base portion 14 of the inner container 9.

[0047] The function of the storage vessel 5 is explained below. The vertical structure or rather the vertical arrangement of the storage vessel 5 alone reduces the sloshing effect, since the movement of the liquid hydrogen H2 caused by the sea is significantly reduced due to the vertical installation and it only impacts the vertically arranged wall 19. The installation of the first intermediate wall 23 or the intermediate walls 23, 26 further reduces the sloshing of the liquid hydrogen H2 in the storage vessel 5. The installation of the intermediate walls 23, 26 can be implemented with little effort in the vertically arranged storage vessel 5, since the movement of the liquid hydrogen H acts identically in all directions and longitudinal and transverse movements of the liquid hydrogen H2 do not have to be considered. Reference symbols used

[0048] 1Vehicle 2Hull 3Bridge 4Fuel cell 5Storage tank 6Symmetry axis 7Foundation 8Outer tank 9Inner tank 10Insulating element 11Base section 12Ceiling section 13Floor section 14Base section 15Ceiling section 16Floor section 17Ceiling 18Floor 19Wall 20Gas zone 21Liquid zone 22Phase boundary 23Partition wall 24Lower edge 25Gap 26Partition wall 27Support 28Support 29Gap 30Gap d19Diameter d23Diameter d26Diameter gDirection of gravity I1Interior I2Interior H2Hydrogen ILength

Claims

1. Storage tank (5) for liquid hydrogen (H2), comprising a cylindrical wall (19) which is constructed rotationally symmetrically to an axis of symmetry (6) running in a direction of gravity (g), a base (18) which closes the wall (19) on one side at the end face, a top part (17) which closes the wall (19) on one side at the end face facing away from the base (18), and an intermediate wall (23, 26) arranged within the wall (19) and at a distance therefrom, characterized in that a gap (25) is provided between a lower edge (24) of the intermediate wall (23, 26) and the base (18), so that an interior space (12) enclosed by the intermediate wall (23, 26) is in fluidic connection with an interior space (11) enclosed by the cylindrical wall (19), so that the liquid hydrogen can flow back and forth between the interior spaces (11, 12), and a gap (29) extending about the axis of symmetry (6) being provided between the cylindrical wall (19) and the intermediate wall (23).

2. Storage tank according to claim 1, wherein the intermediate wall (23, 26) is constructed rotationally symmetrically to the axis of symmetry (6).

3. Storage tank according to either claim 1 or claim 2, comprising a plurality of intermediate walls (23, 26) that are constructed rotationally symmetrically to the axis of symmetry (6), wherein the intermediate walls (23, 26) are arranged coaxially to one another.

4. Storage tank according to claim 3, wherein a gap (30) extending about the axis of symmetry (6) is provided between a first intermediate wall (23) and a second intermediate wall (26) arranged within the first intermediate wall (23).

5. Storage tank according to any of claims 1 - 4, wherein the intermediate wall (23, 26) is supported on the wall (19) by means of supports (27, 28).

6. Storage tank according to any of claims 1 - 5, wherein the intermediate wall (23, 26) is connected to the top part (17).

7. Storage tank according to any of claims 1 - 6, further comprising an inner tank (9) for accommodating the hydrogen (H2) and an outer tank (8) in which the inner tank (9) is accommodated, wherein the intermediate wall (23, 26) starts from the top part (17) and extends in the direction of the base (18) into the inner tank (9) along the axis of symmetry (6).

8. Storage tank according to claim 7, wherein the intermediate wall (23, 26) extends into the inner tank (9) at least along one half of a length (I) of the inner tank (9).

9. Storage tank according to any of claims 1 - 8, wherein the base (18) and the top part (17) are curved outward and in opposite directions in relation to the wall (19).