Storage system for storing a fluid medium, preferably hydrogen, and method for the pressure-tight assembly of the storage system

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 (202) for storing fluid medium, in particular hydrogen, wherein the tank vessel (200) comprises: a first shell element (10), which first shell element (10) forms a tank-vessel interior (201); a second shell element (12), which second shell element (12) surrounds the first shell element (10); and an end cap element (18) at each of the ends (202). The end cap element (18) receives the first shell element (10) and the second shell element (12) at the ends (202) of the tank vessel (202). Furthermore, the first shell element (10) is fully inserted into the second shell element (12) and into the end cap element (18), and is fixed therein. The invention also relates to a method for the pressure-tight assembly of the storage system (1).

Description

[0001] R. 417052

[0002] - 1 -

[0003] Description

[0004] Storage system for storing a fluid medium, preferably hydrogen; method for pressure-tight assembly of the storage system

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

[0006] State of the art

[0007] Today's hydrogen tank systems for mobile applications typically consist of several tanks, often made of carbon fiber reinforced material. These are typically pressurized to a nominal hydrogen pressure of, for example, 350 bar or 900 bar. During filling, storage, or withdrawal of hydrogen in operation, temperatures below the freezing point of water (down to -40°C during withdrawal in a 700 bar system) can occur inside the tank.

[0008] The tank containers can also contain metallic materials, for example.

[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 tank containers or to extraction or filling units requires a complete seal that can withstand dimensional changes resulting from pressure fluctuations and / or temperature variations. In particular, in hydrogen pressure storage systems, storage pressures of up to [value missing] occur, as described above. R. 417052

[0011] - 2 - for example, 700 bar. The pressure changes lead to a significant change in dimensions in the radial and axial directions for all container materials.

[0012] Advantages of the invention

[0013] The storage system according to the invention with the characterizing features of claim 1 has the advantage of providing a safe and pressure-tight storage system with a long service life.

[0014] The storage system for storing a fluid medium, preferably hydrogen, comprises at least one cylindrical tank with two ends for storing the fluid medium, particularly hydrogen. The tank includes a first shell element, which forms the interior of the tank, a second shell element, which surrounds the first shell element, and an end cap element at each end. The end cap element accommodates the first and second shell elements at the ends of the tank. Furthermore, the first shell element is completely inserted into and secured within the second shell element and the end cap element.

[0015] Furthermore, the invention comprises a method for pressure-tight assembly of the storage system described above, comprising the following steps: a. Inserting and securing the first shell element into the second shell element and the end cap elements with a pre-assembled fitting element at one end of the first shell element, b. Sliding the fitting element onto and securing it to the other end of the first shell element, R. 417052

[0016] - 3 - c. Introducing and holding compressed air until a connection between the first shell element and the second shell element is formed under the hot compressed air by means of pressure and temperature, d. Releasing the compressed air and cooling the storage system.

[0017] In this way, a reliable seal of the interfaces in the area of ​​the first shell element, the so-called liner, at the tank ends where they transition to supply adapters for filling and emptying the tanks can be achieved in a structurally simple manner. The first shell element must be able to accommodate, for example, different expansions or deformations resulting from geometric deviations caused by pressure loads.

[0018] In a first advantageous embodiment, the end cap element has an interior space with an inner surface onto which the first shell element is inserted. This design reduces the number of sealing points and thus potential leakage points, as these are self-reinforcing and pressure-activated sealing points.

[0019] In a further embodiment of the invention, the interior has a conical section towards the interior of the tank container and a through channel opposite the direction of the interior of the tank container. Advantageously, a fitting element is arranged in the through channel, with the first sleeve element being fixed between the end cap element and the fitting element or directly within the fitting element. Thus, the first sleeve element is used as an inliner for the temporary fixation of the end cap element during the manufacturing and assembly process and, through the fitting element, creates a tight connection, so that, for example, a connection adapter element can be attached to the fitting element to ensure safe emptying and filling of the tank containers. R. 417052

[0020] - 4 -

[0021] In a further advantageous embodiment, a spring element is provided in the through-channel between the fitting element and the first shell element for fixing the first shell element in the end cap element. Advantageously, the spring element is made of a polymer material or is designed as a metallic spring element. The spring element is, for example, designed as a sealing clip and is pre-tensioned in the end cap element by means of the fitting element. The design of the spring element, which is designed as a sealing clip, is such that a corresponding basic force can be applied by the pre-tensioning and a further increase in the compressive force is achieved by an internal pressure load.

[0022] In a further advantageous embodiment, the conical area of ​​the interior of the end cap element features a surface texture, preferably a wave-shaped recess, for fixing the first shell element. Advantageously, the first shell element is fixed to the end cap element by means of an adhesive bond and firmly connected to it. By means of a surface texture or corresponding adhesive layers in the end cap element prior to the actual insertion of the first shell element as a liner, or alternatively by an undercut in the liner material, the individual components of the tank can be considered as a unit for the subsequent manufacturing process. The actual fixing of the end cap element for high-pressure loading can then, for example, also take place after the complete installation of the tanks in a frame.

[0023] In a further advantageous design, the second shell element is provided for in a recess of the end cap element, at least partially, and firmly fixed within this recess. This allows for a reliable seal of the individual components of the tank container in a structurally simple manner.

[0024] The described storage system is preferably suitable for use in a fuel cell system for storing hydrogen to operate a fuel cell. R. 417052

[0025] - 5 -

[0026] The described storage system is preferably suitable for use in a hydrogen combustion engine system for the provision of hydrogen.

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

[0028] The described storage system is particularly suitable for use in a hydrogen-powered vehicle to provide hydrogen.

[0029] Drawings

[0030] The drawing shows exemplary embodiments of a storage system according to the invention for storing a fluid medium, in particular hydrogen. It shows in

[0031] Fig. 1 shows a possible embodiment of a storage system according to the invention for storing a gaseous medium in a simplified schematic view.

[0032] Fig. 2 shows another possible embodiment of the tank container of the storage system according to the invention from Fig. 1 in longitudinal section in an enlarged view.

[0033] Fig. 3 shows another possible embodiment of the tank container of the storage system according to the invention from Fig. 1 in longitudinal section in an enlarged view,

[0034] Fig. 4a shows another possible embodiment of the tank container of the storage system according to the invention from Fig. 1 in longitudinal section in an enlarged view,

[0035] Fig. 4b shows another possible embodiment of the tank container of the storage system according to the invention from Fig. 1 in longitudinal section in an enlarged view, R. 417052

[0036] - 6 -

[0037] Fig. 4c shows another possible embodiment of the tank container of the storage system according to the invention from Fig. 1 in longitudinal section in an enlarged view,

[0038] Fig. 5 Flowchart for the method for pressure-tight assembly of the storage system according to the invention,

[0039] Fig. 6a Process diagram for the method for pressure-tight assembly of the storage system according to the invention in longitudinal section,

[0040] Fig. 6b Process diagram for the method for pressure-tight assembly of the storage system according to the invention in longitudinal section,

[0041] Fig. 6c Process diagram for the method for pressure-tight assembly of the storage system according to the invention in longitudinal section,

[0042] Fig. 6d Process diagram for the method for pressure-tight assembly of the storage system according to the invention in longitudinal section,

[0043] Fig. 7 shows a hydrogen-powered vehicle with a storage system according to the invention in a simplified schematic view,

[0044] Fig. 8 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.

[0045] Description of the exemplary embodiment

[0046] Fig. 1 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. 7 R. 417052).

[0047] - 7 - or Fig. 8), in schematic view. The storage system 1 has several tank containers 200, which are received in a frame element 205. In this embodiment, the tank containers 200 are cylindrical in their basic form and have two hemispherical ends 202. The storage system 1 here 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.

[0048] Fig. 2 shows a possible embodiment of the storage system 1 according to the invention from Fig. 1 in the area of ​​the tank 200 in an enlarged view. The tank 200 has a longitudinal axis 400, a first shell element 10, a second shell element 12, and an end cap element 18. The first shell element 10 forms a tank interior 201. The second shell element 12 completely surrounds the first shell element 10.

[0049] The end cap element 18 receives the first shell element 10 and the second shell element 12 in the ends 202 of the tank container 200. Furthermore, the first shell element 10 is fully inserted and fixed within the second shell element 12 and within the end cap element 18. The end cap element 18 has an interior space 180 with an inner surface 1801 into which the first shell element 10 is inserted. The first shell element 10 is fixed within the end cap element 18, for example, by means of adhesive bonding, and is firmly connected to it.

[0050] The second shell element 12 is partially received in a recess 1802 of the end cap element 18 and is firmly fixed in this recess 1802 in the end cap element 18.

[0051] The second shell element 12 has a fiber composite material, in particular a carbon fiber composite material.

[0052] In this embodiment, the interior 180 of the end cap element 18 has a conical area 17 facing the interior of the tank 201 and a through channel 170 facing away from the interior of the tank 201. R. 417052

[0053] - 8 -

[0054] Fig. 3 shows another 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. It corresponds essentially in structure and function to the embodiment from Fig. 2. It differs in that the conical area 17 of the interior 180 of the end cap element 18 has a surface texture 52 for fixing the first shell element 10 in the end cap element 18. In this embodiment, the surface texture 52 is a wave-shaped recess 520.

[0055] Fig. 4a shows another possible embodiment of the storage system 1 according to the invention from Fig. 1 in the area of ​​the tank 200 in an enlarged view. It corresponds essentially in structure and function to the embodiment shown in Fig. 2. It differs in that a fitting element 15 is arranged in the through-channel 170, wherein the first shell element 10 is fixed between the end cap element 18 and the fitting element 15. In an alternative embodiment, as shown in Fig. 4b, the first shell element 10 is fixed directly in the fitting element 15. Furthermore, O-rings 23 are arranged in the through-channel 170 for optimized fixing and sealing of the first shell element 10. The fitting element 15 has a through-opening 150 that opens into the through-channel 170 of the end cap element 18, in order to enable filling and emptying of gaseous medium, in particular hydrogen, from the tank 200.

[0056] Fig. 4c shows another possible embodiment of the storage system 1 according to the invention from Fig. 1 in the area of ​​the tank 200 in an enlarged view. It corresponds essentially in structure and function to the embodiment from Fig. 4a. It differs in that a spring element 25 for fixing the first shell element 10 in the end cap element 18 is additionally arranged in the through-channel 170 between the fitting element 15 and the first shell element 10. The spring element 25 is designed here as a sealing clip and comprises polymer material. In an alternative embodiment, the design can also be a metallic spring element. Depending on the embodiment and requirements, the spring element 25 is additionally R. 417052

[0057] - 9 - provided with an elastic thin coating or a small sealing element. The design of the spring element 25, which is configured as a sealing clip, is to be determined such that a corresponding basic force can be applied by the preload and a further increase in the compressive force is achieved by an internal pressure load.

[0058] The invention further relates to a method for the pressure-tight assembly of the storage system 1 according to the invention, comprising the following steps, which are illustrated in a flowchart in Fig. 5: a. Inserting and securing 500 of the first shell element 10 into the second shell element 12 and the end cap elements 18 with a pre-assembled fitting element 15 at one end 101 of the first shell element 10, b. Sliding and securing 501 of the fitting element 15 to the other end 102 of the first shell element 10, c. Introducing and holding 502 compressed air until a connection between the first shell element 10 and the second shell element 12 is established under the hot compressed air by means of pressure and temperature, d. Releasing 503 the compressed air and cooling 504 of the storage system

[0059] 1.

[0060] Figures 6a, 6b, 6c, and 6d show the aforementioned steps in a longitudinal section process diagram. The first shell element 10, together with a pre-assembled fitting element 15, is inserted into the second shell element 12 and the end cap elements 18 at one end 101 of the first shell element 10 and secured (500). A fitting element 15 is slid onto the other end 102 of the first shell element 10 and secured (501). Compressed air at temperatures of, for example, 200°C to 400°C and pressures of, for example, 350 bar or 700 bar is then introduced and maintained into the first shell element 10 and thus into the interior of the tank 201. R. 417052

[0061] - 10 -

[0062] (502) until a connection is formed between the first shell element 10 and the second shell element 12 under the hot compressed air. The compressed air is then released from the first shell element 10 (503) and the entire storage system 1 is cooled (504). These pressure and temperature specifications are example values ​​for a first shell element 10 that encloses plastic, thus allowing plastic deformation.

[0063] Figures 7 and 8 show, by way of example, a hydrogen-powered vehicle 73 with a fuel cell system 70, a fuel cell-powered vehicle 72, 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 Figure 7, the storage system 1 is integrated by way of example into the underbody of the chassis of a vehicle.

Claims

R. 417052 - 11 - 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 (202) for storing fluid medium, in particular hydrogen, wherein the tank container (200) has a first shell element (10), which forms a tank interior (201), a second shell element (12), which surrounds the first shell element (12), and an end cap element (18) at the ends (202) of the tank container (200), wherein the end cap element (18) receives the first shell element (10) and the second shell element (12) in the ends (202) of the tank container (200), characterized in that the first shell element (10) is completely inserted and fixed in the second shell element (12) and in the end cap element (18). is.

2. Storage system (1) according to claim 1 , characterized in that the end cap element (18) has an interior space (180) with an inner surface (1801) on which inner surface (1801) the first shell element (10) is inserted.

3. Storage system (1) according to the preceding claim, characterized in that the interior (180) has a conical area (17) in the direction of the tank interior (201) and a through channel (170) in the opposite direction of the tank interior (201).

4. Storage system (1) according to the preceding claim, characterized in that a fitting element (15) is arranged in the through channel (170), wherein the first shell element (10) is fixed between the end cap element (18) and the fitting element (15) or directly in the fitting element (15).

5. Storage system (1) according to the preceding claim, characterized in that in the through-channel (170) between the fitting element- R. 417052 - 12 - ment (15) and the first shell element (10) a spring element (25) is arranged for fixing the first shell element (10) in the end cap element (18).

6. Storage system (1) according to the preceding claim, characterized in that the spring element (25) comprises a polymer material or is designed as a metallic spring element.

7. Storage system (1) according to claim 3, characterized in that the conical area (17) of the interior (180) of the end cap element (18) has a surface structuring (52), preferably a wave-shaped recess (520), for fixing the first shell element (10).

8. Storage system (1) according to one of the preceding claims, characterized in that the first shell element (10) is fixed in the end cap element (18) by means of an adhesive bond and is firmly connected to it.

9. Storage system (1) according to one of the preceding claims, characterized in that the second shell element (12) is at least partially received in a recess (1802) of the end cap element (18) and is fixed in this recess (1802) in the end cap element (18).

10. 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 9.

11. Hydrogen combustion engine system (71) with a storage system (1) for providing hydrogen according to any one of claims 1 to 9.

12. Fuel cell powered vehicle (72) with a storage system (1) for storing hydrogen for the operation of a fuel cell according to any one of claims 1 to 9.

13. Hydrogen-powered vehicle (73) with a storage system (1) for providing hydrogen according to any one of claims 1 to 9. R. 417052 - 13 - 14. A method for pressure-tight assembly of the storage system (1) according to any one of claims 1 to 9, comprising the following steps: a. Inserting and fastening (500) the first shell element (10) into the second shell element (12) and the end cap elements (18) with a pre-assembled fitting element (15) at one end (101) of the first shell element (10), b. Sliding and fastening (501) the fitting element (15) to the other end (102) of the first shell element (10), c. Introducing and retaining (502) compressed air until a connection between the first shell element (10) and the second shell element (12) is formed under the hot compressed air by means of pressure and temperature, d. Releasing (503) the compressed air and cooling (504) the storage system (1).

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