High-pressure hydrogen reservoir connection device, high-pressure hydrogen storage fuel cell system and manufacturing method for a high-pressure hydrogen reservoir connection device

Description

Technical field

[0001] The present invention relates to a high-pressure hydrogen storage system with a connection device for a high-pressure hydrogen reservoir and a fuel cell system. The present invention further relates to a manufacturing method for a connection device for a high-pressure hydrogen reservoir. State of the art

[0002] Fuel cells are capable of generating electrical energy through a redox reaction at an anode and cathode using a continuously supplied fuel and an oxidizing agent. For example, hydrogen can be supplied in one anode path and atmospheric oxygen in a cathode path simultaneously. In a fuel cell stack, the hydrogen is oxidized by the supplied atmospheric oxygen, thereby generating electrical energy.

[0003] The publication DE 10 2017 212 485 A1 describes a device for storing compressed fluids for a vehicle, in particular for storing hydrogen for a fuel cell vehicle.

[0004] From GB 672 078 A, a connection device suitable for a high-pressure hydrogen reservoir is known, comprising: a base body made of aluminium or an aluminium alloy with a flow channel and at least one connection opening extending radially to the flow channel; and at least one connection element made of steel, wherein the at least one connection element is arranged in the connection opening of the base body.

[0005] WO 2011 / 062631 A1 discloses a connection device suitable for a high-pressure hydrogen reservoir, comprising: a base body made of aluminium or an aluminium alloy with a flow channel and at least one connection opening extending radially to the flow channel; and at least one connection element made of steel, wherein the at least one connection element is arranged in the connection opening of the base body.

[0006] From WO 2016 / 014261 A1 a connection device is known which is suitable for a high-pressure hydrogen reservoir, comprising a base body made of aluminium or an aluminium alloy with a flow channel and at least one connection opening extending radially to the flow channel; and at least one connection element made of steel, wherein the at least one connection element is arranged in the connection opening of the base body. Disclosure of the invention

[0007] The present invention provides a connection device for a high-pressure hydrogen reservoir, a high-pressure hydrogen storage system, a fuel cell system, and a manufacturing method for a connection device for a high-pressure hydrogen reservoir, comprising the features of the independent claims. Further advantageous embodiments are the subject of the dependent claims. Accordingly, the following is planned:

[0008] A high-pressure hydrogen storage device with a connection for a high-pressure hydrogen reservoir, comprising a base body and at least one connection element. The base body is made of aluminum, an aluminum alloy, or another light metal. The connection element is made of steel, in particular stainless steel. The base body has a connection opening extending radially to the flow channel. The at least one connection element is arranged in the connection opening of the base body. Furthermore, the following is planned:

[0009] A high-pressure hydrogen storage system with a connection device according to the invention and at least one high-pressure hydrogen reservoir. Each high-pressure hydrogen reservoir is detachably connected to the connection device via a connection element. Furthermore, the following is planned:

[0010] A fuel cell system comprising a high-pressure hydrogen storage system and a fuel cell device according to the invention. The fuel cell device is connected to the high-pressure hydrogen storage system. Finally, the following is planned:

[0011] A manufacturing process for a connection device for a high-pressure hydrogen reservoir. The process comprises a step for providing a base body. The base body is made of aluminum, an aluminum alloy, or another light metal. In particular, the base body has a flow channel and at least one connection opening extending radially to the flow channel. The process further comprises a step for inserting at least one connection element into the at least one connection opening of the base body. The connection element is made of steel, in particular stainless steel, or another high-strength material. Advantages of the invention

[0012] The present invention is based on the understanding that fuel cell systems obtain their fuel, i.e., hydrogen, from a tank system capable of storing the hydrogen at high pressure of up to 700 bar. This tank system can, in particular, comprise several individual reservoirs. A connection between the individual reservoirs and the fuel cell system is required. According to applicable regulations, this connection must maintain sufficient tightness and pressure resistance even after repeated disconnection and reconnection.

[0013] For such requirements, a fastener made of a high-strength material is needed, one that shows no wear even after repeated loosening and reconnection that could negatively affect its sealing. However, such materials typically have a high specific gravity and are also relatively difficult to machine.

[0014] It is therefore an idea of ​​the present invention to take this knowledge into account and to create a connection device for a high-pressure hydrogen storage system which is easy to manufacture and has the lowest possible weight, but also meets the requirements for sufficient tightness after repeated disconnection and reconnection.

[0015] According to the invention, such a connection device is to be manufactured from a base body and additional connection elements. The base body can be made of a lightweight material, such as aluminum or an aluminum alloy. This can be done, for example, by a casting process, so that this base body can be easily provided as a casting. The connection elements, made of a high-strength material, such as steel, particularly stainless steel, can then be attached to or within this base body. Since this connection between the base body and the connection element is generally only made once during the manufacturing process, the requirements for such a connection are lower than the requirements for a connection to external components, which is intended to be made multiple times.

[0016] Since the connection element itself is made of a high-strength material such as stainless steel, further components such as supply lines, valves, etc. can be connected to this connection element, whereby sufficient stability for a pressure-resistant and gas-tight connection can be guaranteed even after repeated loosening and reconnection.

[0017] Because only the relatively small connection elements of the connection device according to the invention are made of a high-strength material such as stainless steel, while the much larger base body can be made of a lightweight material such as aluminum, the overall weight of the connection device is significantly lower than that of a comparable connection device made entirely of a high-strength material. Furthermore, a lightweight material such as aluminum is much easier to machine than, for example, stainless steel. Therefore, such a base body can also be manufactured much more easily.

[0018] It is understood that suitable materials must be selected for both the base body and the connection elements of the connection device according to the invention, which meet the requirements regarding pressure resistance and, in particular, resistance to the flowing gases, here hydrogen.

[0019] According to one embodiment, the base body comprises an aluminum casting. Such castings are very easy to produce with high precision, especially in larger quantities. Therefore, it is possible to realize the connection device according to the invention cost-effectively and with high quality.

[0020] According to one embodiment, the at least one connection opening has a thread, in particular an internal thread. The at least one connection element is screwed into the connection opening. Accordingly, the connection element has a corresponding external thread. Thus, the connection element can be easily screwed into the base body. This enables simple, fast, and cost-effective manufacturing.

[0021] According to one embodiment, the at least one connecting element has a sealing section. When the connecting element is screwed in, this sealing section rests against an outer surface of the connecting element. In this way, the tightness of the connection between the connecting element and the base body can be further increased by this sealing section.

[0022] According to one embodiment, the thread in the connection opening of the base body has a conical profile. In particular, the diameter of the thread on the outside of the connection element is larger than the diameter of the thread in the flow channel. Additionally or alternatively, the thread of the connection element, which is screwed into the connection opening, can also have a corresponding conical profile.

[0023] According to one embodiment, the at least one connecting element on a section extending away from the base body is designed to be connected to a high-pressure hydrogen reservoir. For this purpose, the shape of the connecting element can be designed to connect to corresponding connection components of the hydrogen reservoir. For example, a corresponding thread can be provided on the connecting element so that it can be screwed onto the corresponding components of the hydrogen reservoir. Since the connecting element is made of a high-strength material such as stainless steel, such a screw connection can ensure the required tightness even after repeated loosening and retightening.

[0024] The above embodiments and further developments can be combined with one another as appropriate. Further embodiments, further developments, and implementations of the invention also include combinations of features of the invention described previously or subsequently with regard to the exemplary embodiments, even if not explicitly mentioned. In particular, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic forms of the invention. Brief description of the drawings

[0025] Further features and advantages of the invention are explained below with reference to the figures. These show: Fig. 1: a schematic representation of a fuel cell system with a connection device according to one embodiment; Fig. 2: a schematic representation of a cross-section through a connection device according to one embodiment; and Fig. 3: a flowchart as it underlies a manufacturing process for a connection device according to one embodiment. Description of embodiments

[0026] Figure 1 Figure 1 shows a schematic representation of the basic structure of a fuel cell system according to one embodiment. The fuel cell system shown here comprises, for example, a fuel cell device 3. In this fuel cell device 3, hydrogen can be oxidized with oxygen, in particular air at oxygen pressure. This process generates electrical energy. This electrical energy can be used, for example, in a motor vehicle for an electric drive.

[0027] The hydrogen required for the operation of the fuel cell system can be stored and supplied in a hydrogen storage system. In particular, the hydrogen can be stored at high pressure, for example up to 700 bar. This hydrogen storage system can be, as shown in Figure 1 depicted, for example, as being formed from one or more individual reservoirs 2-i. The in Figure 1 The depicted number of four individual reservoirs 2-i serves only as an example and does not represent a limitation of the present invention. The individual reservoirs 2-i can be connected to the fuel cell device 3 via a connection device 1. In particular, further components (not shown here) can also be provided between the individual reservoirs 2-i and the connection device 1. For example, these further components can include valves, non-return valves, or other measuring, control, or safety components.

[0028] The individual reservoirs 2-i are detachably connected to the connection device 1. For this purpose, for example, a connecting line of the individual reservoirs 2-i can be screwed to a corresponding component of the connection device 1.

[0029] Figure 2 Figure 1 shows a schematic cross-section through a connection device 1 according to one embodiment. As can be seen, the connection device 1 comprises a base body 10 and one or more connection elements 20.

[0030] The base body 10 has an internal flow channel 11. This flow channel can be connected to the fuel cell device 3 to supply the required hydrogen to the fuel cell device 3.

[0031] Furthermore, the base body 10 includes one or more connection openings 12. These connection openings 12 extend at least approximately radially to the flow channel 11.

[0032] The base body 10 can be made of a light metal, such as aluminum or an aluminum alloy. For example, the base body 10 can be easily manufactured as a casting with high precision. Alternatively, it is also possible to produce the base body 2 from a solid block of material by drilling appropriate holes and performing further post-processing.

[0033] Connection elements 20 are inserted into the base body 10, in particular into the connection openings 12. These connection elements 20 can be made of a high-strength material, such as steel, in particular stainless steel.

[0034] The connecting elements 20 can, for example, be screwed into the connecting openings 12. Both the connecting openings 12 and the connecting element 20 can have a corresponding thread for this purpose. This thread can, for example, be a linear thread that has the same diameter both on the outside of the base body 10 and in the flow channel 11. In this case, a tight seal can be ensured, for example, by means of an additional sealing element 30, such as an O-ring.

[0035] Alternatively, it is also possible that the threads of the connecting element 20 and / or the thread in the connecting openings 12 have a conical profile, with a diameter on the outside of the base body 10 being larger than in an area at the flow opening 11.

[0036] Furthermore, the tightness of the connection between the base body 10 and the connection element 20 can be improved by a sealing section 21 on the connection element 20. In particular, such a sealing section 21 on the connection element 20 can be provided in such a way that the sealing section 21 lies flat on the base body 10 when the connection element 20 is inserted into the base body 10.

[0037] Furthermore, a thread 22 can be provided on the outer surface of the part of the connection element 20 that projects from the base body 10. This allows other components, such as corresponding connection components of the individual reservoirs 21-i or supply lines from the individual reservoirs 21-i, to be screwed to the connection element 20. It is understood that the connection elements 20 can also have any number of other components and configurations for connecting the individual reservoirs 21-i or their supply lines to the connection element 20.

[0038] Figure 3Figure 1 shows a flowchart illustrating the manufacturing process for a connection device 1 according to one embodiment. The underlying connection device 1 can be the connection device 1 described above. Accordingly, the process described below can include any steps required to manufacture the connection device 1 described above.

[0039] In step S1, a base body 10 is first provided. This base body 1 can be, in particular, the previously described base body 1 made of a light metal, especially aluminum or an aluminum alloy. This base body has a flow channel 11 and at least one connection opening 12 extending radially to the flow channel 11.

[0040] In step S2, a connection element 20 is inserted into each of the connection openings 12 of the base body 1. These connection elements 20 can be made of a high-strength material such as steel, in particular stainless steel. The insertion can be carried out, for example, by screwing the connection elements 20 into the connection openings 12.

[0041] In summary, the present invention relates to a connection device for connecting one or more hydrogen storage devices to a fuel cell. For this purpose, a connection device is proposed which comprises a base body made of a light metal such as aluminum and connection elements made of a high-strength material such as stainless steel.

Claims

1. High-pressure hydrogen store, having: a connection device (1) for a high-pressure hydrogen reservoir (2-i), having: a main body (10) made of aluminium or an aluminium alloy with a flow channel (11) and at least one connection opening (12) running radially with respect to the flow channel (11); and at least one connection element (20) made of steel, wherein the at least one connection element (20) is arranged in the connection opening (11) of the main body (10); and at least one high-pressure hydrogen reservoir (2-i), which is in each case detachably connected to the connection device (1) at a connection element (20).

2. High-pressure hydrogen store, having: a connection device (1) for a high-pressure hydrogen reservoir (2-i), according to Claim 1, wherein the main body (10) comprises an aluminium cast part.

3. High-pressure hydrogen store, having: a connection device (1) for a high-pressure hydrogen reservoir (2-i) according to Claim 1 or 2, wherein the at least one connection opening (12) has a thread, and wherein the at least one connection element (20) is screwed into the connection opening (12).

4. High-pressure hydrogen store, having: a connection device (1) for a high-pressure hydrogen reservoir (2-i) according to Claim 3, wherein the at least one connection element (20) comprises a sealing section (21), which rests on an outer side of the main body (10) in the screwed-in state of the connection element (20).

5. High-pressure hydrogen store, having: a connection device (1) for a high-pressure hydrogen reservoir (2-i) according to Claim 3 or 4, wherein the thread has a conical profile, and wherein a diameter of the thread in the region of the outer side of the main body (10) is greater than a diameter of the thread in the region of the flow channel (11).

6. High-pressure hydrogen store, having: a connection device (1) for a high-pressure hydrogen reservoir (2-i) according to any one of the preceding Claims 1 to 5, wherein the at least one connection element (20), by way of a section facing away from the main body (10), is designed to be connected to a high-pressure hydrogen reservoir (2-i).

7. Fuel cell system, having: a high-pressure hydrogen store according to any one of Claims 1 to 6; and a fuel cell device which is connected to the high-pressure hydrogen store.

8. Method for producing a connection device (1) of a high-pressure hydrogen store according to Claim 1 for a high-pressure hydrogen reservoir, comprising the steps of: providing (S1) a main body (10) made of aluminium or an aluminium alloy with a flow channel (11) and at least one connection opening (12) running radially with respect to the flow channel (11); and introducing (S2) at least one connection element (20) made of steel into the at least connection opening (12) of the main body (1).