Storage system for storing a fluid medium, preferably hydrogen, fuel cell system, hydrogen combustion engine system, fuel cell-powered vehicle, and hydrogen-powered vehicle

Abstract

The invention relates to a storage system (1) for storing a fluid medium, preferably hydrogen, comprising at least one tank vessel (200) which has a cylindrical basic shape and has two ends (2000, 2001) for storing fluid medium, in particular hydrogen, wherein the tank vessel (200) comprises at least one shell element (10) and, at each of the ends (2000, 2001) of the tank vessel (200), an end cap element (14). The end cap element (14) at least partially surrounds the shell element (10). Furthermore, the end cap elements (14) of a tank vessel (200) are each fixedly connected in a pressure-tight manner to the shell element (10) at ends (38) of the shell element (10) by means of a tie rod element (16). Compared with the shell element (10), each end cap element (14) comprises a material having a lower coefficient of thermal expansion.

Description

[0001] R. 416899

[0002] - 1 -

[0003] Description

[0004] Storage system for storing a fluid medium, preferably hydrogen, fuel cell system, hydrogen combustion engine system, fuel cell-powered vehicle, hydrogen-powered vehicle

[0005] The invention relates to a storage system for storing a fluid medium, for example hydrogen. This is used, for example, in vehicles with fuel cell propulsion or in vehicles with a hydrogen combustion engine as a drive system.

[0006] State of the art

[0007] Today's hydrogen tank systems for mobile applications typically consist of several tank containers, which are made, for example, from a carbon fiber reinforced material.

[0008] The tank containers can also comprise different materials, for example as a liner with reinforcement made of fibers or monolithically made of steel.

[0009] DE 10 2021 207 190 A1 describes, for example, such a hydrogen tank system for mobile applications with multiple tank containers.

[0010] The connection between individual storage tanks, or between them and extraction or filling units, requires a complete seal that can withstand dimensional changes resulting from pressure fluctuations and / or temperature variations. In particular, hydrogen pressure storage systems experience storage pressures of up to 700 bar, for example. These pressure changes cause significant dimensional changes in both radial and axial directions for all tank materials. R. 416899

[0011] - 2 -

[0012] Advantages of the invention

[0013] The storage system according to the invention with the characterizing features of claim 1 has the advantage of achieving a geometrically flexible and secure storage system.

[0014] The storage system for a fluid medium, preferably hydrogen, comprises at least one cylindrical tank with two ends for storing the fluid medium, particularly hydrogen. The tank has a shell element and an end cap element at each end. This end cap element at least partially surrounds the shell element. Furthermore, the respective end cap elements of a tank are pressure-tightly connected to the shell element at its ends by means of a tie rod element. The end cap element is made of a material with a lower coefficient of thermal expansion compared to the shell element.

[0015] The geometry of the design allows for a simple yet optimized pressure-tight connection of the entire storage system. The dimensions of the outer cap must be selected according to the maximum pressure relative to the material strength. The end cap elements are secured against pressure-induced blow-off by the adjacent tie rod elements, thus relieving the seal of the burden of transmitting axial forces from the storage tank. Maintaining constant pressure on the seal, even at extremely low pressures or temperatures, is ensured by generating a preload on the end cap element, either through design features or by employing appropriate assembly techniques. R. 416899

[0016] - 3 -

[0017] In a first advantageous embodiment, an intermediate element is arranged between the tie rod element and each end of the shell element. Due to pressure, the intermediate element and the end cap elements do not expand radially. The tank expands radially in accordance with the pressure increase. When the pressure increases, the radial seal is automatically subjected to pressure, resulting in a seal. When the pressure decreases, there would be a risk that the pressure on the radial seal would be too low, leading to a leak, which is prevented by the intermediate element. In this way, pressure is generated on the sealing surfaces of the tank in a structurally simple manner, thus achieving a high level of sealing for the entire storage system.

[0018] In an advantageous embodiment, the intermediate element comprises a metallic material, preferably steel or aluminum. The outer shell expands when the temperature rises. According to the invention, the end cap element has a lower coefficient of thermal expansion than the outer shell element. The pressure on the seal increases or remains constant. When the temperature drops, the metallic intermediate element takes over this function.

[0019] In a further embodiment of the invention, it is advantageously provided that the intermediate element comprises the same material as the end cap element. Advantageously, the intermediate element and the end cap element can be joined to each other by a material-fit or form-fit connection.

[0020] In an advantageous further development, it is provided that the intermediate element comprises a material that differs from that of the end cap element.

[0021] In a further embodiment of the invention, it is advantageously provided that the intermediate element has a through-channel. This allows for the simple removal and filling of the tank container with a gaseous medium, in particular hydrogen. R. 416899

[0022] - 4 -

[0023] In a further advantageous design, the end cap elements are provided with several longitudinal openings. The manufacturing-related assembly and the design with an end cap element featuring longitudinal openings and appropriately applied preload ensure that pressure is always applied to the seal, creating a seal against the gas pressure, in this case hydrogen.

[0024] In a further embodiment of the invention, it is advantageously provided that the end cap elements have a through-opening which opens into the through-channel of the intermediate element. This allows for the removal and filling of the tank container with gaseous medium, in particular hydrogen, in a structurally simple manner.

[0025] In a further advantageous development, it is provided that the shell element comprises plastic, a polymer liner and a fiber reinforcement.

[0026] In a further embodiment of the invention, it is advantageously provided that the end cap element is directly connected to a manifold. A manifold is, in this context, a conduit into which all tank containers of the storage system lead and in which a gaseous medium, in particular hydrogen, can be stored.

[0027] The described storage system is preferably suitable for use in a fuel cell system for storing hydrogen for the operation of a fuel cell.

[0028] The described storage system is preferably suitable for use in a hydrogen combustion engine system for the provision of hydrogen.

[0029] The described storage system is preferably suitable for a fuel cell-powered vehicle for storing hydrogen to operate a fuel cell. R. 416899

[0030] - 5 -

[0031] The described storage system is particularly suitable for use in a hydrogen-powered vehicle to provide hydrogen.

[0032] Drawings

[0033] The drawing shows exemplary embodiments of a storage system according to the invention for storing a fluid medium, in particular hydrogen. It shows in

[0034] Fig. 1 shows a possible embodiment of a storage system according to the invention for storing a gaseous medium in a simplified schematic view.

[0035] Fig. 2 shows a possible embodiment of a single tank container of the storage system according to the invention from Fig. 1 in longitudinal section in an enlarged view.

[0036] Fig. 3 shows another possible embodiment of a single tank container of the storage system according to the invention from Fig. 1 in longitudinal section in an enlarged view.

[0037] Fig. 4 shows a possible embodiment of an end cap element of the storage system according to the invention in a sectional view.

[0038] Fig. 5 shows a hydrogen-powered vehicle with a storage system according to the invention in a simplified schematic view,

[0039] Fig. 6 shows a hydrogen-powered vehicle with a fuel cell system or a hydrogen combustion engine system with a storage system according to the invention in a simplified schematic view.

[0040] The description of the embodiments shows a possible embodiment of a storage system 1 according to the invention for storing a gaseous medium, in particular hydrogen, for a consumer system, such as a fuel cell system 70 or a hydrogen combustion engine system 71 (see Fig. 5 R. 416899).

[0041] - 6 - or Fig. 6), in a schematic view. The storage system 1 has several tank containers 200, which are received in a frame element 205. The tank container 200 is cylindrical in its basic form and has two ends 2000, 2001. Furthermore, the individual tank containers 200 are connected to a manifold 500. The manifold 500 collects, stores, or directs the gaseous medium, in particular hydrogen, from or into the individual tank containers 200. The storage system 1 has several tank containers 200, which in this embodiment are received in a frame element 205. In an alternative embodiment, the storage system 1 has, for example, only one tank container 200. Figure 6 shows a possible embodiment of the storage system 1 according to the invention from Fig. 1 in the area of ​​the tank container 200 in an enlarged view.The tank 200 has a longitudinal axis 400, a shell element 10 forming a tank interior 201, and an end cap element 14 at each end 2000 and 2001. The shell element 10 comprises plastic, a polymer liner, and a fiber reinforcement 12. The end cap element 14 surrounds the shell element 10 at the ends 2000 and 2001 of the tank 200. Furthermore, in an alternative configuration, the individual tanks 200 may have additional shell elements. The dimensions of the end cap elements 14 must be selected according to the maximum pressure with respect to the material strength.

[0042] For the extraction and / or filling of the tank interior 201 with fluid medium, in particular hydrogen, the end cap element 14 has a through-opening 32.

[0043] The respective end cap elements 14 of a tank container 200 are pressure-tightly connected to the shell element 10 at its ends 38 by means of a tie rod element 16 extending outwards from the tank container 200, so that the seal does not have to perform the function of force transmission in the axial direction of the storage container 200. Maintaining constant pressure on the seal, even at low pressures or low temperatures, is achieved by generating a preload on the end cap elements 14, either through design measures or by applying R. 416899.

[0044] - 7 - corresponding assembly technology is ensured. Furthermore, sealing elements 18, 24 are arranged between the end cap element 14 and the shell element 10. The axial sealing elements are held under pressure by the external tie rod system. The sealing elements 18, 24, arranged radially to the longitudinal axis 400, are held under pressure by the selection of the material combination of the end cap element, the design of the end cap element, the joining technique used during assembly, and the material of the tank 200. The sealing elements 18, 24 comprise materials that withstand temperatures between -40 degrees Celsius and +85 degrees Celsius.

[0045] Furthermore, the respective end cap element 14 comprises a material with a lower coefficient of thermal expansion compared to the shell element 10.

[0046] The end cap element 14 remains directly connected to the manifold 500. Figure 1 shows another possible embodiment of the invention.

[0047] Storage system 1 from Fig. 1 in the area of ​​the tank 200 in an enlarged view. It largely corresponds in function and construction to the embodiment shown in Fig. 2. However, it differs in that an intermediate element 35 is arranged between the tie rod element 16 and each end 38 of the shell element 10. Due to pressure, the intermediate element 35 and the end cap element 14 do not experience radial expansion. The tank 200 expands radially in accordance with the pressure increase. With an increase in pressure, the radial seal is thus automatically subjected to pressure that leads to sealing. The axial expansion of the tank 200, due to the externally located tie rod element 16, leads to an increase in pressure on the axial seal.Excessive pressure drop on the axial seal at low storage pressure can be counteracted by appropriate preloading of the tie rod element 16 or, for example, by designing the tie rod element 16 with spring assemblies.

[0048] The intermediate element 35 comprises metallic material, preferably steel or aluminum. R. 416899

[0049] - 8 -

[0050] The end cap element 14, for example, comprises the same material as the intermediate element 35, such as steel or aluminum. Thus, the intermediate element 35 and the end cap element 14 can be joined together either by material or form-fitting means.

[0051] When the temperature increases, the outer shell element 10 expands. The end cap element 14 typically has a significantly lower coefficient of thermal expansion than the outer shell element 10. The pressure on the seal increases or remains constant. When the temperature decreases, the previously applied preload ensures that there is always pressure on the seal.

[0052] In alternative versions, the intermediate piece 35 comprises a material that differs from that of the end cap element 14.

[0053] The intermediate element 35 has a through channel 350, wherein the through opening 32 of the end cap element 14 opens into this through channel 350 of the intermediate element 35.

[0054] Furthermore, the end cap element 14 can be dimensioned such that its diameter is smaller than the diameter of the shell element 10. The end cap element 14 is then mounted onto the shell element 10 by heating, resulting in a shrink fit.

[0055] In an alternative embodiment to the embodiments shown in Figs. 2 and 3, the end cap element 14 has several longitudinal openings 140 around its circumference, as shown in Fig. 4, a sectional view of the end cap element 14. The assembly process during manufacturing, or the design with a slotted end cap element 14 and a corresponding preload applied, for example by an outer ring element, ensures that pressure is always present on the seal between the shell element 10 and the end cap element 14, sealing against the gas pressure, in this case hydrogen.

[0056] Fig. 5 and Fig. 6 show, by way of example, a hydrogen-powered vehicle 73 with a fuel cell system 70, a fuel cell-powered vehicle 72, R. 416899

[0057] - 9 - or a hydrogen combustion engine system 71 as a consumer system with a storage system 1 according to the invention in a simplified schematic view. In Fig. 5, the storage system 1 is integrated by way of example in the underbody of the chassis of a vehicle.

Claims

R. 416899 - 10 - Claims 1. Storage system (1) for storing a fluid medium, preferably hydrogen, comprising at least one tank container (200) in a basic cylindrical shape with two ends (2000, 2001) for storing fluid medium, in particular hydrogen, wherein the tank container (200) has at least one shell element (10) and at each of the ends (2000, 2001) of the tank container (200) an end cap element (14), wherein the end cap element (16) at least partially surrounds the shell element (10), characterized in that the respective end cap elements (14) of a tank container (200) are connected to the shell element (10) at ends (38) of the shell element (10) in a pressure-tight manner by means of a tie rod element (16), wherein the respective end cap element (14) comprises a material with a lower coefficient of thermal expansion compared to the shell element (10).

2. Storage system (1) according to claim 1 , characterized in that an intermediate element (35) is arranged between the tie rod element (16) and each end (38) of the shell element (10).

3. Storage system (1) according to claim 1 or 2, characterized in that the intermediate element (35) comprises metallic material, preferably steel or aluminium.

4. Storage system (1) according to claim 1, 2 or 3, characterized in that the intermediate element (35) comprises the same material as the end cap element (14).

5. Storage system (1) according to one of the preceding claims, characterized in that the intermediate element (35) and the end cap element (14) can be joined together by material or form-fitting means.

6. Storage system (1) according to claim 1, 2 or 3, characterized in that the intermediate element (35) comprises a material which differs from that of the end cap element (14). R. 416899 - 11 - 7. Storage system (1) according to one of the preceding claims, characterized in that the intermediate element (35) has a through channel (350).

8. Storage system (1) according to one of the preceding claims, characterized in that the end cap elements (14) have several longitudinal openings (140).

9. Storage system (1) according to claim 7, characterized in that the end cap elements (14) have a through-opening (32) which through-opening (32) opens into the through-channel (350) of the intermediate element (35).

10. Storage system (1) according to one of the preceding claims, characterized in that the shell element (10) comprises plastic, a polymer liner and a fiber reinforcement (12).

11. Storage system (1) according to one of the preceding claims, characterized in that the end cap element (14) is directly connected to a manifold (500).

12. Fuel cell system (70) with a storage system (1) for storing hydrogen for the operation of a fuel cell according to one of claims 1 to 11.

13. Hydrogen combustion engine system (71) with a storage system (1) for providing hydrogen according to any one of claims 1 to 11.

14. Fuel cell powered vehicle (72) with a storage system (1) for storing hydrogen for the operation of a fuel cell according to one of claims 1 to 11.

15. Hydrogen-powered vehicle (73) with a storage system (1) for providing hydrogen according to any one of claims 1 to 11.

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