Storage system for storing low-temperature medium and fuel cell system

Abstract

The invention relates to a reservoir system (1) for storing a cryogenic medium for a fuel cell system, comprising: a pressure vessel (3) for receiving the medium; a gas delivery line (4) for filling / extracting a gaseous medium from the pressure vessel; the invention relates to a pressure vessel (1) comprising a gas supply line (5) for supplying / extracting a liquid medium from the pressure vessel, and a liquid supply line (5) for supplying / extracting a liquid medium from the pressure vessel, the gas supply line and the liquid supply line being coupled to a controllable shut-off device (6), the gas supply line and / or the liquid supply line having a heating element (7) for heating the medium in the pressure vessel. The invention further relates to a fuel cell system.

Description

Technical Field

[0001] The present invention relates to a memory system for storing cryogenic media for a fuel cell system, and a fuel cell system having such a memory system. Background Technology

[0002] In a fuel cell system (FCS), oxygen from ambient air is typically used as an oxidant to react with hydrogen in the fuel cell to produce water or water vapor, which then provides electrical power through electrochemical conversion. The hydrogen required for this process is stored in a dedicated tank under high pressure and low temperature. Here, hydrogen is typically present in part in liquid form and part in gaseous form within the storage container.

[0003] To remove the medium from the storage container, it is known that the removed medium is heated outside the storage container, and a portion of the heated medium is guided back into the storage container, so that the medium surrounding the guided portion of the medium in the storage container is also heated and thus evaporated.

[0004] For example, document DE 10 2020 206 689 A describes a storage system for storing hydrogen, which includes a first heat exchanger arranged outside the storage container and in flow connection with a gas extraction line for heating the medium, and an inner tank heat exchanger arranged downstream of the first heat exchanger and inside the storage container and in flow connection with the gas extraction line for heating the liquid medium in the storage container. Summary of the Invention

[0005] The present invention provides a storage system for storing cryogenic media for a fuel cell system, and a fuel cell system having the features of the independent claims.

[0006] According to a first aspect, the present invention relates to a storage system for storing a cryogenic medium for a fuel cell system, comprising a pressure vessel for receiving the medium; a gas delivery line for filling / extracting a gaseous medium from the pressure vessel; and a liquid delivery line for filling / extracting a liquid medium from the pressure vessel, wherein the gas delivery line and the liquid delivery line are coupled to a controllable shut-off device; wherein the gas delivery line and / or the liquid delivery line have heating elements within the pressure vessel for heating the medium.

[0007] According to a second aspect, the present invention relates to a fuel cell system having a refueling device and a consumer, the refueling device and the consumer being fluidly connected to a storage system.

[0008] The concept upon which this invention is based is to incorporate a heat-generating element or heating element on at least one existing medium guide in the memory system, i.e., on the input and / or output lines, or on the gas and / or liquid delivery lines. This means that the inner tank or pressure vessel has at least one heat-generating element on at least one existing medium guide leading into or out of the internal space of the tank. The input and / or output lines transport the medium into and / or out of the internal space of the tank or pressure vessel.

[0009] Advantageously, existing resources, namely gas delivery lines and / or liquid delivery lines already present in known storage systems, can be utilized to evaporate liquid media or heat gaseous media within the storage elements and / or line elements of the fuel cell system. This means that heating the contents of the tank or pressure vessel via existing input and / or output lines expands the functionality of the storage system. This avoids the need for additional interfaces. Furthermore, the efficiency of the required heat input can be improved.

[0010] Another advantage is the arrangement of the heating element on the medium guide leading to the liquid or gas phase, i.e., on the gas or liquid delivery line. By arranging the heating element on the liquid delivery line, large pressure changes in the pressure vessel can be provided with less energy. By arranging the heating element on the gas delivery line, small pressure changes can be provided with less energy, thus improving the quality of regulation.

[0011] Advantageous configurations and extensions are derived from the additional dependent claims and the description with reference to the accompanying drawings.

[0012] According to the expansion scheme of the memory system, heating elements are arranged at least in sections along the flow path of the medium on the gas delivery line. Preferably, the heating elements are arranged in the end sections or middle sections of the gas delivery line. Therefore, heating of the medium can be provided directly at the location where it is desired to be used.

[0013] The cryogenic medium is, for example, hydrogen.

[0014] According to another extension of the memory system, heating elements are arranged at least in sections along the flow path of the medium on the liquid delivery line. Preferably, the heating elements are arranged in the end sections or middle sections of the liquid delivery line. Therefore, heating of the medium can be provided directly at the location where it is desired to be used.

[0015] According to another extension of the memory system, the heating element is constructed as a resistance heating device.

[0016] According to another extension of the memory system, the gas delivery line and / or liquid delivery line has at least two distinct chambers, wherein the heating element is disposed in one of the at least two chambers that is not permeable by the medium. In this way, the heating element is protected from contact with the cryogenic medium.

[0017] According to another extension of the memory system, the heating element includes a cable assembly connected to a power source for supplying power to the heating element. Therefore, power can be supplied via a cable or cable assembly that can extend protectively against hydrogen within the multi-chamber system of the medium guide, for example, in one of the at least two chamber assemblies.

[0018] According to another extension, the memory system includes a double-walled container for receiving a cryogenic medium, wherein a pressure vessel forms the inner container of the double-walled container, and the double-walled container additionally includes an outer container surrounding the pressure vessel. Therefore, the memory system can better insulate the cryogenic medium relative to the environment.

[0019] According to another extension, the memory system also includes a control device electronically connected to the heating element and configured to increase the pressure within the pressure vessel by heating the medium. Thus, the medium can be heated precisely, for example, by manipulating the heating element of a liquid delivery line for large pressure changes. Alternatively or additionally, for example, the heating element of a gas delivery line can be manipulated for small pressure changes.

[0020] According to another extension, the storage system also includes a first heat exchanger, flowably connected to the gas delivery line and disposed outside the pressure vessel, for heating the medium, and an inner tank heat exchanger, flowably connected to the gas delivery line, disposed downstream of the first heat exchanger and inside the pressure vessel, for heating the liquid medium within the pressure vessel. In this way, the liquid medium can be heated via the inner tank heat exchanger in addition to the heating element.

[0021] In other words, the structure of a pressure vessel can be described as follows: The inner tank or pressure vessel consists of a pressure body (also called an inner liner) coated on the inside, a heat radiation shield or third wall layer, and a fabric composed of carbon fibers surrounding the pressure body. Attached Figure Description

[0022] The invention is explained below with reference to the accompanying drawings. The drawings show: Figure 1 : A memory system according to an embodiment of the present invention.

[0023] In all the accompanying drawings, identical or functionally equivalent elements and devices are given the same reference numerals. The numbering of method steps is for clarity and should generally not imply a specific temporal order. In particular, multiple method steps may be performed simultaneously. Detailed Implementation

[0024] Other advantages, features and details of the invention will become apparent from the following description, in which different embodiments are described in detail with reference to the accompanying drawings.

[0025] Figure 1 A memory system 1 is shown. The memory system 1 is particularly suitable for storing cryogenic media 2a; 2b, such as hydrogen, for fuel cell systems. Typically, hydrogen exists in a gaseous phase 2a and a liquid phase 2b.

[0026] The storage system 1 includes a pressure vessel 3 for receiving hydrogen gas 2a; 2b. Exemplarily, the storage system 1 includes a double-walled container for receiving cryogenic hydrogen gas 2a; 2b, wherein the pressure vessel 3 forms the inner container of the double-walled container, and the double-walled container additionally includes an outer container 9 surrounding the pressure vessel 3.

[0027] In addition, a spacer 14 is arranged in sections between the outer container 9 and the inner container 3 to position and fix the two shells of the double-walled container relative to each other.

[0028] Furthermore, the storage system 1 includes a gas delivery line 4 for filling or extracting gaseous hydrogen 2a from the pressure vessel 3 and a liquid delivery line 5 for filling or extracting liquid hydrogen 2b from the pressure vessel 3. The gas delivery line 4 is configured, for example, to extract gaseous hydrogen 2a from the pressure vessel 3, such that its free end terminates above the liquid surface, near the top of the pressure vessel 3, within the pressure vessel 3. The liquid delivery line 5 is configured to extract liquid hydrogen from the pressure vessel 3, such that its free end terminates below the liquid surface, near the bottom of the pressure vessel 3, within the pressure vessel 3.

[0029] The terms “top” and “bottom” here refer to the usual installation location of the pressure vessel, such as in a moving or flying transport vehicle, where gravity acts in the direction toward the bottom of the pressure vessel during normal operation of the transport vehicle.

[0030] Gas delivery line 4 and liquid delivery line 5 are coupled to a controllable shut-off device 6. In this embodiment, the controllable shut-off device 6 includes a first controllable shut-off valve 6a disposed in gas delivery line 4 and a second controllable shut-off valve 6b disposed in liquid delivery line 5. Both shut-off valves are located outside pressure vessel 3. Figure 1 In this context, the shut-off valve is located inside the outer container 9, that is, between the pressure vessel 3 and the outer container 9 of the double-walled container, especially in a vacuum space.

[0031] However, the shut-off device 6 is not limited to this embodiment, but can instead be constructed as a controllable switching valve having a first inlet on the gas delivery line 4 and a second inlet on the liquid delivery line 5.

[0032] The memory system 1 also includes a control device 10, which is electronically connected to the heating element 7 and configured to increase the pressure inside the pressure vessel 3 by heating hydrogen gas 2a; 2b.

[0033] The shut-off valves 6a and 6b can also be controlled by a control device 10, for example, arranged in a vacuum space (as shown) or arranged outside the entire double-walled container. Here, the flow through the shut-off valves can preferably not only be interrupted or released, but also reduced.

[0034] The gas delivery line 4 or the liquid delivery line 5 has a heating element 7 within the pressure vessel 3 for heating hydrogen gas 2a; 2b. Exemplarily, in Figure 1 In the gas delivery line 4 and the liquid delivery line 5, there are heating elements 7 configured as resistance heaters.

[0035] The first heating element 7 is here arranged in the end section of the gas delivery line 4. Alternatively or additionally, the first heating element 7 may be arranged in the middle section of the gas delivery line 4. Furthermore, the second heating element 7 is here arranged in the end section of the liquid delivery line 5. Alternatively or additionally, the second heating element 7 may be arranged in the middle section of the liquid delivery line 5.

[0036] Gas delivery line 4 and liquid delivery line 5 each have two distinct chambers. Exemplarily, the heating element 7 is disposed in the lower chamber of either chamber, where hydrogen cannot flow through. This means that hydrogen, for example, flows through the upper chamber without contacting the heating element 7.

[0037] The cable assembly 8, which is connected to the power source to supply power to the heating element 7, is also arranged in the lower chamber assembly of the gas delivery line 4 or the liquid delivery line 5.

[0038] The pressure vessel 3 can also be filled from the fuel cell system filling device 13 via the gas delivery line 4 and / or the liquid delivery line 5, preferably also via the first shut-off valve 6a and / or the second shut-off valve 6b.

[0039] Gas delivery line 4 and liquid delivery line 5 merge into a common line after two shut-off valves 6a and 6b. A flow rectifier valve, especially a check valve 15, can be arranged in gas delivery line 4 to allow flow only in the direction from the first shut-off valve 6a to the first heat exchanger 11, while the reverse direction is blocked.

[0040] Gas delivery line 4 and liquid delivery line 5 are connected in the form of a common pipeline to a first heat exchanger 11, which is located outside the pressure vessel 3, for example, between the pressure vessel 3 and the outer vessel 9 in a double-walled vessel, and is used to heat the extracted medium.

[0041] Downstream of the first heat exchanger 11, an inner tank heat exchanger 12 for heating the liquid medium in the pressure vessel 3 is arranged inside the pressure vessel 3, through which heated hydrogen gas extracted from the pressure vessel flows. Through heating at the inner tank heat exchanger 12, the liquid hydrogen gas in the pressure vessel 3 is partially heated and evaporated.

[0042] For example, the pressure in the pressure vessel 3 can be regulated by means of the first and second shut-off valves 6a and 6b. Here, the control device 10 can be configured to control the pressure in the pressure vessel 3 during hydrogen extraction by selectively opening the first shut-off valve 6a and / or the second shut-off valve 6b, so that hydrogen is selectively extracted from the pressure vessel 3 through the gas delivery line 4 and / or through the liquid delivery line 5.

[0043] Downstream of the inner tank heat exchanger 12 and outside the pressure vessel 3, a second heat exchanger 16 for heating hydrogen can be arranged.

[0044] The medium extracted via gas delivery line 4 and / or liquid delivery line 5 is delivered downstream of the inner tank heat exchanger 12 to the consumer 14, particularly the fuel cell. A third shut-off valve 17 is exemplarily arranged between the second heat exchanger 16 and the consumer 14.

[0045] Although the invention has been illustrated by way of example with reference to embodiments above, the invention is not limited thereto and can be modified in various ways. In particular, combinations of the foregoing embodiments are also conceivable.

Claims

1. A storage system (1) for storing cryogenic media (2a; 2b) for a fuel cell system, comprising: Pressure vessel (3) for receiving the medium (2a; 2b); Gas delivery line (4) for filling / extracting gaseous medium (2a) from the pressure vessel (3); and Liquid delivery line (5) for filling / extracting liquid medium (2b) from the pressure vessel (3), wherein, The gas delivery line (4) and the liquid delivery line (5) are coupled to a controllable shut-off device (6); The gas delivery line (4) and / or the liquid delivery line (5) have heating elements (7) inside the pressure vessel (3) for heating the medium (2a; 2b).

2. The memory system (1) according to claim 1, wherein, The heating element (7) is arranged at least in sections, particularly in the end sections or middle sections of the gas delivery line (4), along the flow path of the medium on the gas delivery line (4).

3. The memory system (1) according to claim 1 or 2, wherein, The heating element (7) is arranged at least in sections, particularly in the end sections or middle sections of the liquid delivery line (5), along the flow path of the medium on the liquid delivery line (5).

4. The memory system (1) according to any one of the preceding claims, wherein, The heating element (7) is constructed as a resistance heater.

5. The memory system (1) according to any one of the preceding claims, wherein, The gas delivery line (4) and / or the liquid delivery line (5) have at least two different chamber devices, wherein the heating element (7) is disposed in one of the at least two chamber devices that cannot be traversed by the medium.

6. The memory system (1) according to any one of the preceding claims, wherein, The heating element (7) includes a cable assembly (8) connected to a power source for supplying power to the heating element (7).

7. The memory system (1) according to any one of the preceding claims, wherein, The memory system (1) includes a double-walled container for receiving the cryogenic medium (2a; 2b), wherein the pressure vessel (3) forms the inner container of the double-walled container, and the double-walled container additionally includes an outer container (9) surrounding the pressure vessel (3).

8. The memory system (1) according to any one of the preceding claims further comprises a control device (10) electronically connected to the heating element (7) and configured to increase the pressure inside the pressure vessel (3) by heating the medium (2a; 2b).

9. The memory system (1) according to any one of the preceding claims further comprises: a first heat exchanger (11) connected in flow to the gas delivery line (4) and disposed outside the pressure vessel (3) for heating the medium; and an inner tank heat exchanger (12) connected in flow to the gas delivery line (4), disposed downstream of the first heat exchanger (11) and inside the pressure vessel (3) for heating the liquid medium (2b) in the pressure vessel (3).

10. A fuel cell system having a storage system (1) according to any one of the preceding claims and having a refueling device (13) and a consumer (14) fluidly connected to the storage system (1).

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