A metal hydride hydrogen energy storage system and its thermal management method

Abstract

This invention belongs to the field of hydrogen energy technology and provides a metal hydride hydrogen energy storage system and its thermal management method. The metal hydride hydrogen energy storage system includes a fuel cell, a heat exchange fluid circulation system, and multiple parallel-connected metal hydride hydrogen storage devices. The heat exchange fluid circulation system is connected to the multiple parallel-connected metal hydride hydrogen storage devices through the fuel cell. One end of each metal hydride hydrogen storage device is provided with a hydrogen inlet / outlet, a first heat exchange fluid inlet, and a second heat exchange fluid inlet, and the other end is provided with a first heat exchange fluid outlet and a second heat exchange fluid outlet. A hydrogen buffer zone is provided between the hydrogen inlet / outlet and the metal hydride region. The metal hydride hydrogen storage device is filled with metal hydride and also has a through-type inner and outer heat exchange tube bundle. This significantly improves the hydrogen storage / desorption efficiency of the hydrogen storage reactor and shortens the reaction time.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen energy technology, and particularly relates to a metal hydride hydrogen energy storage system and its thermal management method. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Current hydrogen storage solutions include high-pressure gaseous hydrogen storage, cryogenic liquid hydrogen storage, and solid-state hydrogen storage. Among these, solid-state hydrogen storage, especially metal hydride-based solid-state hydrogen storage, offers advantages such as low storage pressure, high storage density, and excellent safety, making it a crucial direction for future hydrogen storage technology development. Existing solid-state hydrogen storage systems primarily accelerate heat transfer during hydrogen storage and release by embedding heat exchange tube bundles, finned heat exchange tubes, and specially designed heat exchange channels within the bed. However, while these embedded heat exchangers effectively exchange heat with the adjacent metal hydride region, the low thermal conductivity of the metal hydrides limits the reaction rate of reactants far from the heat exchange surface. This results in reaction dead zones with extremely low reaction fractions within the reactor, prolonging the hydrogen storage / release cycle and limiting the large-scale commercial application of metal hydride hydrogen storage technology. Furthermore, fuel cell systems have a power generation efficiency of approximately 50%, exhibiting significant heat dissipation. Summary of the Invention

[0004] To address the technical problems existing in the background art, the present invention provides a metal hydride hydrogen energy storage system and its thermal management method, which can increase the heat exchange rate in the metal hydride hydrogen storage / desorption process within the reaction dead zone, and reduce the energy consumption of heat exchange fluid circulation by utilizing the heat dissipation of traditional hydrogen energy storage systems, significantly improving the hydrogen storage / desorption efficiency of the hydrogen storage reactor, shortening the reaction time, thereby promoting the large-scale and commercialization process of metal hydride hydrogen storage reactors.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] The first aspect of the present invention provides a metal hydride hydrogen energy storage system.

[0007] A metal hydride hydrogen energy storage system includes: a fuel cell, a heat exchange fluid circulation system, and multiple metal hydride hydrogen storage devices connected in parallel; the heat exchange fluid circulation system is connected to the multiple metal hydride hydrogen storage devices in parallel through the fuel cell.

[0008] The metal hydride hydrogen storage device has a hydrogen inlet / outlet, a first heat exchange fluid inlet, and a second heat exchange fluid inlet at one end, and a first heat exchange fluid outlet and a second heat exchange fluid outlet at the other end. A hydrogen buffer zone is provided between the hydrogen inlet / outlet and the metal hydride region. The metal hydride hydrogen storage device is filled with metal hydride and also has a through-type inner heat exchange tube bundle and an outer heat exchange tube bundle. The first heat exchange fluid inlet and the first heat exchange fluid outlet are connected to the inner heat exchange tube bundle, and the second heat exchange fluid inlet and the second heat exchange fluid outlet are connected to the outer heat exchange tube bundle. The heat exchange fluid circulation system is connected to the corresponding metal hydride hydrogen storage device through the first heat exchange fluid inlet, the second heat exchange fluid inlet, the first heat exchange fluid outlet, and the second heat exchange fluid outlet.

[0009] In one embodiment, the metal hydride hydrogen storage device is further provided with a first inner manifold and a second inner manifold that are isolated from each other.

[0010] In one embodiment, the inner heat exchange tube bundle is disposed in the first inner header, and the outer heat exchange tube bundle is disposed in the second inner header.

[0011] In one embodiment, the heat exchange fluid circulation system includes a room temperature fluid circulation subsystem and a low temperature / high temperature fluid circulation subsystem. The room temperature fluid circulation subsystem is connected to the metal hydride hydrogen storage device through a first heat exchange fluid inlet and a first heat exchange fluid outlet. The low temperature / high temperature fluid circulation subsystem is connected to the metal hydride hydrogen storage device through a second heat exchange fluid inlet and a second heat exchange fluid outlet.

[0012] In one embodiment, the room temperature fluid circulation subsystem includes a room temperature liquid bath and a first circulation pump; the first circulation pump is installed on the pipe at the output end of the room temperature liquid bath; the heat exchange fluid output from the room temperature liquid bath is divided into two paths, one of which flows into the inner manifold after passing through the fuel cell and returns to the room temperature liquid bath, and the other flows directly into the inner manifold and returns to the room temperature liquid bath.

[0013] In one implementation, a first heat exchange fluid valve and a second heat exchange fluid valve are respectively provided on the two paths of the heat exchange fluid output from the room temperature liquid bath.

[0014] In one embodiment, the low-temperature / high-temperature fluid circulation subsystem includes a low-temperature / high-temperature liquid bath and a second circulation pump, wherein the second circulation pump is installed on the pipeline at the output end of the low-temperature / high-temperature liquid bath; the heat exchange fluid output from the low-temperature / high-temperature liquid bath flows directly into the second inner manifold and then returns to the low-temperature / high-temperature liquid bath.

[0015] As one implementation method, a third heat exchange fluid valve is installed on the heat exchange fluid pipeline output from the low-temperature / high-temperature liquid bath.

[0016] In one embodiment, the metal hydride hydrogen storage device is placed vertically.

[0017] A second aspect of the present invention provides a thermal management method based on a metal hydride hydrogen energy storage system as described above.

[0018] A thermal management method based on the metal hydride hydrogen energy storage system as described above, comprising:

[0019] Hydrogen storage process: Hydrogen flows into the metal hydride region through the hydrogen buffer zone at the top of the metal hydride hydrogen storage device to achieve hydrogen adsorption. The heat released by the metal hydride hydrogen storage is absorbed and carried away by the heat exchange fluid through the heat exchange tube bundle. In the room temperature fluid circulation, the fuel cell side valve is closed, and the room temperature fluid flows into the inner heat exchange tube through the first inner header to cool the metal hydride between the heat exchange tubes, and then returns to the room temperature liquid bath. In the cryogenic fluid circulation, the cryogenic fluid flows into the outer heat exchange tube through the second inner header to cool the metal hydride in the reaction dead zone, and then returns to the cryogenic liquid bath.

[0020] Hydrogen release process: During room temperature fluid circulation, the fuel cell side valve is open and the metal hydride hydrogen storage device side valve is closed. The room temperature fluid passes through the fuel cell, cools the fuel cell, and then flows into the internal heat exchange tube through the first inner header to heat the metal hydride between the heat exchange tubes, and then returns to the room temperature liquid bath. During high temperature fluid circulation, the high temperature fluid flows into the outer heat exchange tube through the second inner header to heat the metal hydride in the reaction dead zone, and then returns to the low temperature liquid bath. The metal hydride is heated by the heat exchange fluid, desorbs and releases hydrogen, and the hydrogen flows out through the buffer zone of the hydrogen storage device.

[0021] The beneficial effects of this invention are:

[0022] (1) The metal hydride hydrogen storage device in the metal hydride hydrogen energy storage system of the present invention uses heat exchange tube bundles to enhance the heat exchange rate of the device and separates the heat exchange fluid inlets of the outermost heat exchange tube bundle and the inner heat exchange tube bundle. During the hydrogen storage / de-hydrogen process, the outer heat exchange tube bundle is filled with heat exchange fluid at a lower / higher temperature, which effectively improves the rate of hydrogen storage reaction and hydrogen de-hydrogenation reaction in the reaction dead zone and reduces the energy consumption of heat exchange fluid circulation.

[0023] (2) In the hydrogen energy storage system thermal management method of the present invention, during the hydrogen storage process, cold fluid in the low temperature liquid bath is introduced into the inner and outer heat exchange tube bundles of the hydrogen storage device; cold fluid in the room temperature liquid bath is introduced into the inner heat exchange tube bundle. While ensuring the hydrogen storage rate of metal hydride inside the device, the hydrogen storage performance of the reaction dead zone inside the device is significantly improved and the energy consumption of heat exchange fluid is reduced.

[0024] (3) In the hydrogen energy storage system thermal management method of the present invention, during the hydrogen release process, the hot fluid in the high temperature liquid bath is introduced into the inner and outer heat exchange tube bundles of the hydrogen storage device; the fluid in the room temperature liquid bath is introduced into the internal heat exchange tube bundle after passing through the fuel cell cooling circuit. While ensuring the hydrogen release rate of the metal hydride inside the device, the hydrogen release performance of the reaction dead zone inside the device is significantly improved and the energy consumption of the heat exchange fluid is reduced.

[0025] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0026] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0027] Figure 1 This is a schematic diagram of a metal hydride hydrogen energy storage system according to an embodiment of the present invention;

[0028] Figure 2(a) is a front view of the metal hydride hydrogen energy storage device according to an embodiment of the present invention;

[0029] Figure 2(b) is a left view of the metal hydride hydrogen energy storage device according to an embodiment of the present invention;

[0030] Figure 2(c) is a top view of the metal hydride hydrogen energy storage device according to an embodiment of the present invention;

[0031] Figure 2(d) is a three-dimensional structural schematic diagram of the metal hydride hydrogen energy storage device according to an embodiment of the present invention;

[0032] Figure 3(a) is a cross-sectional view of the metal hydride hydrogen energy storage device in Figure 2(a);

[0033] Figure 3(b) is a BB cross-sectional view of the metal hydride hydrogen energy storage device in Figure 2(a);

[0034] Figure 3(c) is a CC cross-sectional view of the metal hydride hydrogen energy storage device in Figure 2(a);

[0035] Figure 3(d) is a DD cross-sectional view of the metal hydride hydrogen energy storage device in Figure 2(a);

[0036] Figure 3(e) is a cross-sectional view of the metal hydride hydrogen energy storage device in Figure 2(c).

[0037] In the picture:

[0038] 1-Fuel cell, 2-First heat exchange fluid valve, 3-First circulation pump, 4-Second heat exchange fluid valve, 5-Metal hydride hydrogen storage device, 6-Third heat exchange fluid valve, 7-Second circulation pump, 8-Cryogenic / High-temperature liquid bath, 9-Room temperature liquid bath, 10-Hydrogen inlet / outlet, 11-First heat exchange fluid inlet, 12-Second heat exchange fluid inlet, 13-Outer shell, 14-First heat exchange fluid outlet, 15-Second heat exchange fluid outlet, 16-Hydrogen inlet buffer zone, 17-Inlet of the second inner manifold, 18-Inlet of the first inner manifold, 19-Inner heat exchange tube bundle, 20-Outlet of the first inner manifold, 21-Outlet of the second inner manifold, 22-Metal hydride. Detailed Implementation

[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0040] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0041] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0042] Figure 1 This is a schematic diagram of a metal hydride hydrogen energy storage system according to an embodiment of the present invention; as shown. Figure 1 As shown, this embodiment of the invention provides a metal hydride hydrogen energy storage system, which includes: a fuel cell 1, a heat exchange fluid circulation system, and multiple metal hydride hydrogen storage devices 5 connected in parallel; the heat exchange fluid circulation system is connected to the multiple metal hydride hydrogen storage devices 5 connected in parallel through the fuel cell.

[0043] like Figures 2(a)-2(d)As shown, one end of the metal hydride hydrogen storage device 5 is provided with a hydrogen inlet / outlet 10, a first heat exchange fluid inlet 11, and a second heat exchange fluid inlet 12, and the other end is provided with a first heat exchange fluid outlet 14 and a second heat exchange fluid outlet 15; a hydrogen buffer zone 16 is provided between the hydrogen inlet / outlet 11 and the metal hydride region; the metal hydride hydrogen storage device 5 is filled with metal hydride 22, and the metal hydride hydrogen storage device 5 is also provided with a penetrating inner heat exchange tube bundle 19 and an outer heat exchange tube bundle. The first heat exchange fluid inlet 11 and the first heat exchange fluid outlet 14 are connected to the inner heat exchange tube bundle, and the second heat exchange fluid inlet 12 and the second heat exchange fluid outlet 15 are connected to the outer heat exchange tube bundle; the heat exchange fluid circulation system is connected to the corresponding metal hydride hydrogen storage device 5 through the first heat exchange fluid inlet 11, the second heat exchange fluid inlet 12, the first heat exchange fluid outlet 14, and the second heat exchange fluid outlet 15.

[0044] The metal hydride hydrogen storage device 5 is placed vertically.

[0045] In one or more embodiments, the inner heat exchange tube bundle and the outer heat exchange tube bundle include, but are not limited to, one or a combination of several of heat exchange tube bundles, finned tube bundles, and other heat exchange channels. The finned tubes and reactor walls are made of high thermal conductivity metals, such as aluminum, copper, aluminum alloys, or copper alloys, to improve the heat exchange rate between the heat exchange fluid and the metal hydride.

[0046] The metal hydride materials in the embodiments of the present invention include, but are not limited to, one or a combination of several of LaNi5, Mg, Mg2Ni, FeTi, etc.

[0047] In the embodiment of the present invention, Figures 3(a)-3(e) As shown, the metal hydride hydrogen storage device 5 also includes an outer casing 13, inside which are a first inner manifold and a second inner manifold that are isolated from each other. The inner heat exchange tube bundle 19 is disposed within the first inner manifold, and the outer heat exchange tube bundle is disposed within the second inner manifold. 17 is the inlet of the second inner manifold, 18 is the inlet of the first inner manifold, 20 is the outlet of the first inner manifold, and 21 is the outlet of the second inner manifold.

[0048] In this embodiment of the invention, the heat exchange fluid circulation system includes a room temperature fluid circulation subsystem and a low-temperature / high-temperature fluid circulation subsystem. The room temperature fluid circulation subsystem is connected to the metal hydride hydrogen storage device 5 through a first heat exchange fluid inlet 11 and a first heat exchange fluid outlet 14; the low-temperature / high-temperature fluid circulation subsystem is connected to the metal hydride hydrogen storage device 5 through a second heat exchange fluid inlet 12 and a second heat exchange fluid outlet 15. The room temperature fluid circulation subsystem and the low-temperature / high-temperature fluid circulation subsystem are isolated from each other.

[0049] In specific implementation, the room temperature fluid circulation subsystem includes a room temperature liquid bath 9 and a first circulation pump 3; the first circulation pump 3 is installed on the pipe at the output end of the room temperature liquid bath 9; the heat exchange fluid output from the room temperature liquid bath 9 is divided into two paths, one of which flows through the fuel cell 1 into the inner manifold and returns to the room temperature liquid bath 9, and the other flows directly into the inner manifold and returns to the room temperature liquid bath 9. A first heat exchange fluid valve 2 and a second heat exchange fluid valve 4 are respectively installed on the two paths of the heat exchange fluid output from the room temperature liquid bath 9.

[0050] In specific implementation, the low-temperature / high-temperature fluid circulation subsystem includes a low-temperature / high-temperature liquid bath 8 and a second circulation pump 7. The second circulation pump 7 is installed on the pipeline at the output end of the low-temperature / high-temperature liquid bath 8. The heat exchange fluid output from the low-temperature / high-temperature liquid bath 8 flows directly into the second inner manifold and then returns to the low-temperature / high-temperature liquid bath 8. A third heat exchange fluid valve 6 is installed on the heat exchange fluid pipeline output from the low-temperature / high-temperature liquid bath 8.

[0051] The heat exchange fluids in embodiments of the present invention include, but are not limited to, one or a combination of several of water, heat transfer oil, and air.

[0052] In one or more embodiments, a method based on, for example Figure 1 The thermal management method for the metal hydride hydrogen energy storage system shown includes:

[0053] Hydrogen storage process: Hydrogen flows into the metal hydride region through the hydrogen buffer zone at the top of the metal hydride hydrogen storage device to achieve hydrogen adsorption. The heat released by the metal hydride hydrogen storage is absorbed and carried away by the heat exchange fluid through the heat exchange tube bundle. In the room temperature fluid circulation, the fuel cell side valve is closed, and the room temperature fluid flows into the inner heat exchange tube through the first inner header to cool the metal hydride between the heat exchange tubes, and then returns to the room temperature liquid bath. In the cryogenic fluid circulation, the cryogenic fluid flows into the outer heat exchange tube through the second inner header to cool the metal hydride in the reaction dead zone, and then returns to the cryogenic liquid bath.

[0054] Hydrogen release process: During room temperature fluid circulation, the fuel cell side valve is open and the metal hydride hydrogen storage device side valve is closed. The room temperature fluid passes through the fuel cell, cools the fuel cell, and then flows into the internal heat exchange tube through the first inner header to heat the metal hydride between the heat exchange tubes, and then returns to the room temperature liquid bath. During high temperature fluid circulation, the high temperature fluid flows into the outer heat exchange tube through the second inner header to heat the metal hydride in the reaction dead zone, and then returns to the low temperature liquid bath. The metal hydride is heated by the heat exchange fluid, desorbs and releases hydrogen, and the hydrogen flows out through the buffer zone of the hydrogen storage device.

[0055] The thermal management method for metal hydride hydrogen energy storage systems in this invention can increase the heat exchange rate during the metal hydride hydrogen storage / desorption process within the reaction dead zone, and reduce the energy consumption of heat exchange fluid circulation by utilizing the heat dissipation of traditional hydrogen energy storage systems; it will also significantly improve the hydrogen storage / desorption efficiency of the hydrogen storage reactor and shorten the reaction time, thereby promoting the large-scale and commercialization of metal hydrogen storage reactors.

[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A metal hydride hydrogen energy storage system, characterized in that, include: The system comprises a fuel cell, a heat exchange fluid circulation system, and multiple metal hydride hydrogen storage devices connected in parallel; the heat exchange fluid circulation system is connected to the multiple metal hydride hydrogen storage devices in parallel via the fuel cell. The metal hydride hydrogen storage device has a hydrogen inlet / outlet, a first heat exchange fluid inlet, and a second heat exchange fluid inlet at one end, and a first heat exchange fluid outlet and a second heat exchange fluid outlet at the other end. A hydrogen buffer zone is provided between the hydrogen inlet / outlet and the metal hydride region. The metal hydride hydrogen storage device is filled with metal hydride and also has a through-type inner heat exchange tube bundle and an outer heat exchange tube bundle. The first heat exchange fluid inlet and the first heat exchange fluid outlet are connected to the inner heat exchange tube bundle, and the second heat exchange fluid inlet and the second heat exchange fluid outlet are connected to the outer heat exchange tube bundle. The heat exchange fluid circulation system is connected to the corresponding metal hydride hydrogen storage device through the first heat exchange fluid inlet, the second heat exchange fluid inlet, the first heat exchange fluid outlet, and the second heat exchange fluid outlet. The metal hydride hydrogen storage device is further provided with a first inner header and a second inner header that are isolated from each other; the inner heat exchange tube bundle is located in the first inner header, and the outer heat exchange tube bundle is located in the second inner header; the heat exchange fluid circulation system includes a room temperature fluid circulation subsystem and a low temperature / high temperature fluid circulation subsystem, the room temperature fluid circulation subsystem is connected to the metal hydride hydrogen storage device through a first heat exchange fluid inlet and a first heat exchange fluid outlet; the low temperature / high temperature fluid circulation subsystem is connected to the metal hydride hydrogen storage device through a second heat exchange fluid inlet and a second heat exchange fluid outlet.

2. The metal hydride hydrogen energy storage system as described in claim 1, characterized in that, The room temperature fluid circulation subsystem includes a room temperature liquid bath and a first circulation pump; the first circulation pump is installed on the pipe at the output end of the room temperature liquid bath; the heat exchange fluid output from the room temperature liquid bath is divided into two paths, one of which flows into the inner manifold after passing through the fuel cell and returns to the room temperature liquid bath, and the other flows directly into the inner manifold and returns to the room temperature liquid bath.

3. The metal hydride hydrogen energy storage system as described in claim 2, characterized in that, The heat exchange fluid output from the room temperature liquid bath is divided into two paths, each equipped with a first heat exchange fluid valve and a second heat exchange fluid valve.

4. The metal hydride hydrogen energy storage system as described in claim 1, characterized in that, The low-temperature / high-temperature fluid circulation subsystem includes a low-temperature / high-temperature liquid bath and a second circulation pump. The second circulation pump is installed on the pipeline at the output end of the low-temperature / high-temperature liquid bath. The heat exchange fluid output from the low-temperature / high-temperature liquid bath flows directly into the second inner manifold and then returns to the low-temperature / high-temperature liquid bath.

5. The metal hydride hydrogen energy storage system as described in claim 4, characterized in that, A third heat exchange fluid valve is installed on the heat exchange fluid pipeline output from the low-temperature / high-temperature liquid bath.

6. The metal hydride hydrogen energy storage system as described in claim 1, characterized in that, The metal hydride hydrogen storage device is placed vertically.

7. A thermal management method for a metal hydride hydrogen energy storage system based on any one of claims 1-6, characterized in that, include: Hydrogen storage process: Hydrogen flows into the metal hydride region through the hydrogen buffer zone at the top of the metal hydride hydrogen storage device to achieve hydrogen adsorption. The heat released by the metal hydride hydrogen storage is absorbed and carried away by the heat exchange fluid through the heat exchange tube bundle. In the room temperature fluid circulation, the fuel cell side valve is closed, and the room temperature fluid flows into the inner heat exchange tube through the first inner header to cool the metal hydride between the heat exchange tubes, and then returns to the room temperature liquid bath. In the cryogenic fluid circulation, the cryogenic fluid flows into the outer heat exchange tube through the second inner header to cool the metal hydride in the reaction dead zone, and then returns to the cryogenic liquid bath. Hydrogen release process: During room temperature fluid circulation, the fuel cell side valve is open and the metal hydride hydrogen storage device side valve is closed. The room temperature fluid passes through the fuel cell, cools the fuel cell, and then flows into the internal heat exchange tube through the first inner header to heat the metal hydride between the heat exchange tubes, and then returns to the room temperature liquid bath. During high temperature fluid circulation, the high temperature fluid flows into the outer heat exchange tube through the second inner header to heat the metal hydride in the reaction dead zone, and then returns to the low temperature liquid bath. The metal hydride is heated by the heat exchange fluid, desorbs and releases hydrogen, and the hydrogen flows out through the buffer zone of the hydrogen storage device.

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