A solid-state hydrogen storage tank based on heat self-balancing and heat control method

Abstract

The present invention belongs to the field of thermal management of hydrogen storage technology, and provides a solid-state hydrogen storage tank based on heat self-balancing and a heat control method. Among them, the solid-state hydrogen storage tank based on heat self-balancing includes a tank body, a flange cover, a hydrogen storage and heat storage unit, a U-shaped tube and an air duct; the flange cover is sealed with the upper open end of the tank body; a hydrogen inlet and outlet are provided on the flange cover; the hydrogen storage and heat storage unit is arranged in the tank body, and is composed of a hydrogen storage layer and a heat storage layer; at least two of the U-shaped tubes are inserted into the hydrogen storage and heat storage unit and are distributed circumferentially; the air duct is divided into a main air duct and a plurality of circumferentially distributed branch air ducts, which are used to guide the hydrogen to be evenly distributed and circulated in the hydrogen storage layer; one end of the main air duct is connected to the hydrogen inlet and outlet and passes through the tank body for connecting to a hydrogen source; the other end of the main air duct is connected to a plurality of branch air ducts, which are inserted into the hydrogen storage layer and penetrate into the interior thereof and are distributed circumferentially.

Description

Technical Field

[0001] The present invention belongs to the field of thermal management of hydrogen storage technology, and in particular relates to a solid-state hydrogen storage tank based on thermal self-balancing and a heat control method. Background Art

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

[0003] Proton exchange membrane fuel cells (PEMFCs), fueled by hydrogen, offer advantages such as high energy density, long power supply life, fast startup, and low operating temperature. However, achieving safe and efficient hydrogen storage remains a technical bottleneck hindering the development of hydrogen fuel cells. Metal hydride hydrogen storage offers numerous advantages, including low storage pressure, high volumetric hydrogen density, excellent safety, and simple storage and decomposition processes. It is suitable for small and medium-sized hydrogen fuel cell power generation systems and is one of the most promising hydrogen storage methods.

[0004] The storage and release of hydrogen in metal hydrides is accompanied by significant thermal effects, causing their temperature to change and deviate from the appropriate temperature conditions for the reaction. Integrating phase change materials in metal hydride hydrogen storage tanks has the potential to achieve self-thermal management without the need for an external heat source. However, the inherent thermal conductivity of phase change materials is low, and the heat transfer area of ​​traditional sleeve-type hydrogen storage tanks coupled with phase change materials is limited and cannot meet application requirements, resulting in low heat transfer efficiency. Although built-in heat exchangers with different structures are conducive to improving the heat transfer rate, the released reaction heat is directly discharged by the heat exchange fluid and cannot be effectively recycled. In this context, combining the coupled thermal management method of built-in heat exchangers and phase change materials can not only ensure heat exchange efficiency, but also help improve energy utilization.

[0005] However, existing technologies generally assume that the internal heat exchanger and phase change material operate independently in metal hydride hydrogen storage tanks. Therefore, how to effectively integrate and coordinate the interaction between the two has become one of the key challenges in improving hydrogen storage performance and optimizing thermal management efficiency. In addition, the melting process of the phase change material is affected by the combined effects of natural convection and heat conduction. Natural convection increases the melting rate, but it also causes the upper part of the phase change region to melt faster than the lower part, resulting in non-uniform melting and thermal stratification, which is not conducive to the heat and mass transfer behavior in the metal hydride hydrogen storage tank coupled with the phase change material. Summary of the Invention

[0006] In order to solve the technical problems existing in the above-mentioned background technology, the purpose of the present invention is to provide a solid-state hydrogen storage tank and a heat control method based on heat self-balancing, which can solve the high energy consumption problem in the thermal management of solid-state hydrogen storage tanks and improve the thermal stratification phenomenon in metal hydride hydrogen storage tanks coupled with phase change materials.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A first aspect of the present invention provides a solid-state hydrogen storage tank based on thermal self-balancing type.

[0009] A solid-state hydrogen storage tank based on heat self-balancing type, comprising: a tank body, a flange cover, a hydrogen storage-heat storage unit, a U-shaped tube and an air guide tube;

[0010] The flange cover is sealed with the upper open end of the tank body; the flange cover is provided with a hydrogen inlet and outlet; the hydrogen storage-heat storage unit is disposed within the tank body and is composed of a hydrogen storage layer and a heat storage layer; the heat storage layer is coated on the outside of the hydrogen storage layer in the form of a jacket;

[0011] At least two of the U-shaped tubes are inserted into the hydrogen storage-heat storage unit and are distributed circumferentially; one end of the U-shaped tube is located in the hydrogen storage layer, and the other end is located in the heat storage layer; both ends of the U-shaped tube extend to the outside of the flange cover and are connected to an external power pump; a heat exchange fluid flows inside the U-shaped tube;

[0012] The gas pipe is divided into a main gas pipe and several branch gas pipes distributed in a circular manner, which are used to guide the hydrogen to be evenly distributed and circumferentially distributed in the hydrogen storage layer; one end of the main gas pipe is connected to the hydrogen inlet and outlet and passes through the tank body to connect to the hydrogen source; the other end of the main gas pipe is connected to several branch gas pipes, which are inserted into the hydrogen storage layer and penetrate into its interior and are distributed in a circular manner.

[0013] As an embodiment, the number of the hydrogen storage-heat storage units is set to at least two, and the hydrogen storage-heat storage units are sequentially wrapped around the outside of other hydrogen storage-heat storage units in the form of jackets.

[0014] As an embodiment, the number of U-shaped tubes inserted in each of the hydrogen storage-heat storage units is the same and is distributed in a circular pattern.

[0015] As an embodiment, a main air pipe is placed in the center of each hydrogen storage-heat storage unit and an equal number of branch air pipes are placed around the unit in a circumferential distribution.

[0016] As an embodiment, the hydrogen storage layer is filled with metal hydride hydrogen storage material for storing hydrogen; the heat storage layer is filled with composite phase change material for recovering reaction heat during the hydrogen storage process and utilizing it during the hydrogen release process.

[0017] As an embodiment, a graphite gasket for sealing is provided at the connection between the flange cover and the tank body.

[0018] As an embodiment, a thermocouple inserted into the tank body is welded on the flange cover, and the thermocouple is used to monitor the temperature changes inside the tank body during the storage and discharge of hydrogen; or a pressure sensor and a pressure relief valve are connected to the flange cover, and the pressure sensor is used to detect the changes in the hydrogen pressure in the tank body, and the pressure relief valve is used to relieve the pressure when the pressure in the storage tank exceeds the safety pressure.

[0019] A second aspect of the present invention provides a heat control method for a solid-state hydrogen storage tank based on a heat self-balancing type.

[0020] A heat control method based on the heat self-balancing solid-state hydrogen storage tank as described above comprises:

[0021] During the hydrogen storage process, hydrogen from the hydrogen source enters the hydrogen storage tank through the gas pipe, diffuses into the hydrogen storage layer, undergoes a hydrogen absorption reaction with the metal hydride hydrogen storage material in the hydrogen storage layer, and releases reaction heat; part of the reaction heat is transferred through the wall between the hydrogen storage layer and the heat storage layer, and the other part is extracted from the hydrogen storage layer by the heat exchange fluid flowing in the U-shaped tube driven by the power pump and transferred to the heat storage layer for storage;

[0022] Subsequently, during the hydrogen desorption process, in addition to transferring the heat required for the hydrogen desorption reaction through the wall between the hydrogen storage layer and the heat storage layer, the power pump drives the heat exchange fluid to extract the stored reaction heat from the heat storage layer and transfer it to the hydrogen storage layer as a heat source for the hydrogen desorption reaction; the metal hydride hydrogen storage material absorbs heat and undergoes a hydrogen desorption reaction, and the released hydrogen is released from the hydrogen storage tank through the gas duct and supplied to the hydrogen fuel cell as fuel.

[0023] As an implementation method, when the hydrogen demand is less than the set value or in the cold start, the power pump is controlled to be closed. At this time, heat exchange is carried out only through the contact surface between the hydrogen storage layer and the heat storage layer in the hydrogen storage tank; when the hydrogen demand is greater than or equal to the set value, the power pump is controlled to be turned on. At this time, heat is transferred collaboratively in the hydrogen storage tank through the circulating flow of the heat exchange fluid in the U-tube and the contact surface of the hydrogen storage layer.

[0024] As an implementation method, the hydrogen outlet pressure and the flow rate of the heat exchange fluid are regulated according to the hydrogen supply rate requirement of the hydrogen fuel cell to meet the hydrogen demand under different working conditions.

[0025] The beneficial effects of the present invention are:

[0026] (1) The present invention provides a solid-state hydrogen storage tank based on heat self-balancing, which adopts a sandwich structure with alternating distribution of hydrogen storage layers and heat storage layers. By increasing the heat exchange area, the heat exchange efficiency can be effectively improved. Through the melting and solidification process of the phase change material in the hydrogen storage tank, the reaction heat is recovered and reused, which solves the high energy consumption problem in the thermal management of the solid-state hydrogen storage system and improves the energy utilization rate of the hydrogen storage and desorption process.

[0027] (2) The present invention adopts a U-shaped tube to connect the hydrogen storage layer and the heat storage layer, thereby improving the effective heat transfer coefficient inside the hydrogen storage tank. Through the flow heat transfer of the heat exchange fluid in the U-shaped tube and the heat storage function of the PCM, the efficient recovery and reuse of the reaction heat and the self-heating balance of the hydrogen storage tank are achieved, which greatly improves the thermal energy utilization efficiency and hydrogen storage and desorption performance.

[0028] (3) In order to solve the problems of thermal stratification and heat accumulation in the hydrogen storage tank, the present invention proposes to fill the solid-state hydrogen storage tank with composite phase change materials with different foam metal contents along the heat flow direction of the heat storage layer. The foam metal content in the top area with high heat flux density is low, and the foam metal content in the bottom area with low heat flux density is high. This distribution method is conducive to improving the uniformity of temperature distribution and ensuring that all areas of the hydrogen storage layer have the same degree of heat exchange efficiency, thereby improving the hydrogen storage and desorption efficiency.

[0029] (4) The present invention provides a heat control method based on a heat self-balancing solid-state hydrogen storage tank. The controller adjusts the hydrogen outlet pressure and the flow rate of the heat exchange fluid to meet the heat exchange requirements of the solid-state hydrogen storage tank under different working conditions, thereby achieving a wide range of hydrogen supply rate regulation.

[0030] (5) In order to improve the problem of uneven contact time between hydrogen and hydrogen storage materials caused by a single hydrogen inlet and outlet, the present invention evenly arranges multiple gas pipes in the hydrogen storage layer, so that hydrogen can enter or discharge the hydrogen storage tank more quickly and evenly, greatly shortening the response time.

[0031] Advantages of additional aspects of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0033] Figure 1 Schematic diagram of the three-dimensional structure of a heat self-balancing solid-state hydrogen storage tank according to an embodiment of the present invention;

[0034] Figure 2 This is a diagram of the internal heat exchange structure of a heat self-balancing solid-state hydrogen storage tank according to an embodiment of the present invention;

[0035] Figure 3 Schematic diagram of the two-dimensional structure of a heat self-balancing solid-state hydrogen storage tank according to an embodiment of the present invention;

[0036] Figure 4 This is a structural diagram of an air guide pipe in a heat self-balancing solid-state hydrogen storage tank according to an embodiment of the present invention;

[0037] Figure 5 This is a distribution diagram of air ducts in a heat self-balancing solid-state hydrogen storage tank according to an embodiment of the present invention;

[0038] Figure 6 Schematic diagram of a tank body of a heat self-balancing solid-state hydrogen storage tank according to an embodiment of the present invention;

[0039] Figure 7 This is a schematic diagram of a support structure in a heat self-balancing solid-state hydrogen storage tank according to an embodiment of the present invention;

[0040] Figure 8 This is a flow chart of a heat control method for a solid-state hydrogen storage tank based on heat self-balancing according to an embodiment of the present invention.

[0041] In the figure, 1-tank body; 2-flange cover; 21-hydrogen inlet and outlet; 22-graphite gasket; 3-hydrogen storage-heat storage unit; 31-hydrogen storage layer; 32-heat storage layer; 321-first composite phase change material; 322-second composite phase change material; 323-third composite phase change material; 4-U-shaped tube; 5-support structure; 6-gas guide pipe; 61-main gas guide pipe; 62-sub-gas guide pipe. DETAILED DESCRIPTION

[0042] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0043] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0044] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0045] In the present invention, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom", etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present invention, and do not specifically refer to any part or element in the present invention, and should not be understood as limiting the present invention.

[0046] In the present invention, terms such as "fixed connection," "connected," and "connection" should be interpreted broadly to mean a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediary. Relevant researchers or technicians in this field may determine the specific meanings of these terms in the present invention based on specific circumstances, and they should not be construed as limitations of the present invention.

[0047] The present invention provides a solid-state hydrogen storage tank and heat control method based on thermal self-balancing to solve the high energy consumption problem in the thermal management of the solid-state hydrogen storage system and improve the thermal stratification phenomenon in the hydrogen storage system, thereby improving the overall performance and hydrogen storage and desorption efficiency.

[0048] Example 1

[0049] In this embodiment, if Figure 1-Figure 7 As shown, a solid-state hydrogen storage tank based on heat self-balancing is provided, comprising: a tank body 1, a flange cover 2, a hydrogen storage-heat storage unit 3, a U-shaped tube 4, and an air guide tube 6; the flange cover 2 is sealedly connected to the upper open end of the tank body 1; the flange cover 2 is provided with a hydrogen inlet and outlet 21; the hydrogen storage-heat storage unit 3 is disposed in the tank body 1, and is composed of a hydrogen storage layer 31 and a heat storage layer 32; the heat storage layer 32 is coated on the outside of the hydrogen storage layer 31 in the form of a jacket;

[0050] like Figure 2 and Figure 3 As shown, at least two of the U-shaped tubes 4 are inserted into the hydrogen storage-heat storage unit 3 and are distributed in a circular pattern; one end of the U-shaped tube 4 is located in the hydrogen storage layer 31, and the other end is located in the heat storage layer 32; both ends of the U-shaped tube 4 pass through the outside of the flange cover 2 and are connected to an external power pump; a heat exchange fluid circulates inside the U-shaped tube 4 to achieve efficient transfer and recycling of reaction heat; wherein the heat exchange fluid includes but is not limited to one of a single-phase heat exchange fluid or a phase change convection heat exchange fluid, such as water, air, molten salt, thermal oil and refrigerant, and the heat exchange fluid is preferably water.

[0051] like Figure 4 and Figure 5 As shown, the gas pipe 6 is divided into a main gas pipe 61 and several branch gas pipes 62 distributed in a circular manner, which are used to guide the hydrogen to be evenly distributed and circumferentially distributed in the hydrogen storage layer 31; one end of the main gas pipe 61 is connected to the hydrogen inlet and outlet 21 and passes through the outside of the tank body 1 for connecting to a hydrogen source; the other end of the main gas pipe 61 is connected to several branch gas pipes 62, and the branch gas pipes 62 are inserted into the hydrogen storage layer 31 and penetrate into the interior thereof, and are distributed in a circular manner.

[0052] In order to ensure the safety of the main air pipe, the main air pipe 61 passes through the outside of the tank body 1 and is provided with a safety valve.

[0053] In one or more embodiments, the number of the hydrogen storage-heat storage units 3 is set to at least two, and the hydrogen storage-heat storage units 3 are sequentially wrapped around the outside of other hydrogen storage-heat storage units 3 in the form of jackets.

[0054] For example, in this embodiment, the number of hydrogen storage-heat storage units 3 is two, and one hydrogen storage-heat storage unit 3 is wrapped around the outside of another hydrogen storage-heat storage unit 3 in the form of a jacket.

[0055] The number of U-shaped tubes 4 inserted into each of the hydrogen storage-heat storage units 3 is the same (for example, 5, the number of which can be set according to actual conditions), and they are all distributed in a circular pattern.

[0056] It should be noted here that the geometric shape of the U-shaped tube 4 includes but is not limited to a straight tube, a corrugated tube, a spiral tube, etc., and is preferably a straight tube.

[0057] In order to prevent the U-shaped tube 4 from shaking and shifting in the tank body 1, it needs to be fixed. Preferably, a circular hole can be opened on the flange cover 2, and the U-shaped tube 4 can be firmly connected to the flange cover 2 with bolts to enhance its stability. At the same time, a certain amount of extra space is reserved at the bottom of the tank body 1 for placing a support structure or a buffer device to accommodate thermal expansion and provide additional support to ensure the safety and reliability of the operation of the hydrogen storage tank.

[0058] In this embodiment, a main air pipe 61 is placed in the center of the first hydrogen storage-heat storage unit and the same number (for example, 5) of circumferentially distributed branch air pipes 62 are placed around the first hydrogen storage-heat storage unit and the second hydrogen storage-heat storage unit.

[0059] To mitigate the problems of uneven melting and thermal stratification caused by natural convection, the heat storage layer 32 is filled axially from top to bottom with composite phase-change materials of varying porosity. The uniformity of the temperature distribution is improved by varying the metal foam content with the heat flux distribution, thereby ensuring the same degree of heat transfer efficiency across all regions of the metal hydride hydrogen storage material. Preferably, the porosities are 0.95, 0.9, and 0.85, respectively, meaning that the metal foam content in the heat storage layer 32 increases gradually from top to bottom.

[0060] The wall of the gas duct is made of a porous material with high thermal conductivity, including but not limited to foam metal, and is provided with a plurality of pores along the axial direction for circulating hydrogen.

[0061] In other embodiments, the outer layer of the air guide tube is covered with a filter layer for intercepting impurities and filtering hydrogen, and the pore size of the filter layer is no greater than 5 μm.

[0062] In a specific implementation process, the hydrogen storage layer 31 is filled with metal hydride hydrogen storage materials for storing hydrogen; wherein the metal hydride hydrogen storage materials include but are not limited to one or a combination of LaNi5, Mg, Mg2Ni or MgH2.

[0063] In a specific implementation, the heat storage layer 32 is filled with a composite phase change material to recover reaction heat during the hydrogen storage process and utilize it during the hydrogen release process. For example, the composite phase change material includes a first composite phase change material 321, a second composite phase change material 322, and a third composite phase change material 323.

[0064] Among them, the composite phase change material is a uniform composite of a phase change material and a foam metal, and the phase change material includes but is not limited to one or a combination of materials such as paraffin, fatty acid, salt, and trihydrate LiNO3·3H2O; the foam metal includes but is not limited to one or a combination of materials such as foam copper, foam nickel, and foam aluminum, and is preferably foam copper with high thermal conductivity and high specific surface area.

[0065] Preferably, when the metal hydride hydrogen storage material is LaNi5, a rare earth AB5 metal with advantages such as moderate reaction pressure, room temperature hydrogen absorption and desorption, and easy activation, the melting point of the selected phase change material should be between the reaction equilibrium temperatures corresponding to the LaNi5 absorption and desorption pressures. The operating pressures for hydrogen absorption and desorption are 10 bar and 3 bar, respectively. The melting point of LiNO3·3H2O matches the equilibrium temperature of LaNi5 absorption and desorption at the selected pressures. Furthermore, compared to other phase change materials, LiNO3·3H2O has a larger latent heat of fusion (296 kJ / kg) and requires less volume, resulting in a higher hydrogen storage density per unit volume.

[0066] In some optional embodiments, a graphite gasket 22 for sealing is provided at the connection between the flange cover 2 and the tank body 1 .

[0067] In one or more embodiments, a thermocouple inserted into the tank body 1 is welded on the flange cover 2, and the thermocouple is used to monitor the temperature change inside the tank body 1 during the hydrogen storage and discharge process;

[0068] The flange cover 2 is connected to a pressure sensor and a pressure relief valve. The pressure sensor is used to detect changes in the hydrogen pressure in the tank body 1, and the pressure relief valve is used to relieve pressure when the pressure in the tank exceeds a safety pressure.

[0069] like Figure 1 and Figure 7 As shown, a supporting structure 5 is further provided at the bottom of the tank body 1 .

[0070] This embodiment utilizes a sandwich structure with alternating hydrogen and heat storage layers. This increases heat exchange area, effectively improving heat exchange efficiency. The melting and solidification process of the phase change material within the hydrogen storage tank allows for the recovery and reuse of reaction heat, addressing the high energy consumption associated with thermal management in solid-state hydrogen storage systems and improving energy efficiency during the hydrogen storage and degassing process. Furthermore, by packing composite phase change materials with varying metal foam content within the solid-state hydrogen storage tank along the heat flow direction of the heat storage layer, thermal stratification and heat accumulation within the tank are addressed, thereby improving hydrogen storage and degassing efficiency.

[0071] Example 2

[0072] In this embodiment, if Figure 8 As shown, a heat control method based on the heat self-balancing solid-state hydrogen storage tank as described above is provided, comprising:

[0073] During the hydrogen storage process, hydrogen from the hydrogen source enters the hydrogen storage tank through the gas pipe, diffuses into the hydrogen storage layer, undergoes a hydrogen absorption reaction with the metal hydride hydrogen storage material in the hydrogen storage layer, and releases reaction heat; part of the reaction heat is transferred through the wall between the hydrogen storage layer and the heat storage layer, and the other part is extracted from the hydrogen storage layer by the heat exchange fluid flowing in the U-shaped tube driven by the power pump and transferred to the heat storage layer for storage;

[0074] Subsequently, during the hydrogen desorption process, in addition to transferring the heat required for the hydrogen desorption reaction through the wall between the hydrogen storage layer and the heat storage layer, the power pump drives the heat exchange fluid to extract the stored reaction heat from the heat storage layer and transfer it to the hydrogen storage layer as a heat source for the hydrogen desorption reaction; the metal hydride hydrogen storage material absorbs heat and undergoes a hydrogen desorption reaction, and the released hydrogen is released from the hydrogen storage tank through the gas duct and supplied to the hydrogen fuel cell as fuel.

[0075] In this way, during the entire process, the heat transfer of the heat exchange fluid in the U-shaped tube running through the hydrogen storage layer and the heat storage layer and the heat storage function of the phase change material are used to achieve efficient recovery and reuse of the reaction heat, greatly improving the thermal energy utilization efficiency and hydrogen storage performance.

[0076] When the hydrogen demand is less than the set value or cold start occurs, the power pump is controlled to be closed. At this time, heat exchange is only carried out through the contact surface between the hydrogen storage layer and the heat storage layer in the hydrogen storage tank; when the hydrogen demand is greater than or equal to the set value, the power pump is controlled to be turned on. At this time, heat is transferred collaboratively in the hydrogen storage tank through the circulation of the heat exchange fluid in the U-tube and the contact surface of the hydrogen storage layer.

[0077] In one or more embodiments, the hydrogen outlet pressure and heat exchange fluid flow rate are regulated based on the hydrogen supply rate requirements of the hydrogen fuel cell to meet hydrogen demand under different operating conditions. By adjusting the hydrogen outlet pressure and heat exchange fluid flow rate through the controller, the heat exchange requirements of the solid-state hydrogen storage tank under different operating conditions are met, thereby achieving a wide range of hydrogen supply rate regulation.

[0078] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A solid-state hydrogen storage tank based on heat self-balancing type, characterized in that: include: Tank body, flange cover, hydrogen storage-heat storage unit, U-shaped tube and gas guide tube; The flange cover is sealed with the upper open end of the tank body; the flange cover is provided with a hydrogen inlet and outlet; the hydrogen storage-heat storage unit is disposed within the tank body and is composed of a hydrogen storage layer and a heat storage layer; the heat storage layer is coated on the outside of the hydrogen storage layer in the form of a jacket; At least two of the U-shaped tubes are inserted into the hydrogen storage-heat storage unit and are distributed circumferentially; one end of the U-shaped tube is located in the hydrogen storage layer, and the other end is located in the heat storage layer; both ends of the U-shaped tube extend to the outside of the flange cover and are connected to an external power pump; a heat exchange fluid flows inside the U-shaped tube; The gas pipe is divided into a main gas pipe and a plurality of circumferentially distributed branch gas pipes, which are used to guide the hydrogen to be evenly distributed and circulated within the hydrogen storage layer; one end of the main gas pipe is connected to the hydrogen inlet and outlet and passes through the tank body to be connected to the hydrogen source; the other end of the main gas pipe is connected to a plurality of branch gas pipes, which are inserted into the hydrogen storage layer and penetrate into the interior thereof and are distributed in a circumferential manner; The solid-state hydrogen storage tank based on thermal self-balancing adopts a sandwich structure with alternating hydrogen storage layers and heat storage layers. The heat storage layer is filled with composite phase change materials with different porosities in sequence from top to bottom along the axial direction. The uniformity of temperature distribution is improved by changing the foam metal content with the heat flow distribution to ensure that the heat exchange efficiency of each area of ​​the metal hydride hydrogen storage material is the same. The porosities are 0.95, 0.9, and 0.85, respectively, that is, the foam metal content in the heat storage layer gradually increases from top to bottom.

2. The heat self-balancing solid-state hydrogen storage tank according to claim 1, characterized in that: The number of the hydrogen storage-heat storage units is set to at least two, and the hydrogen storage-heat storage units are sequentially wrapped around the outside of other hydrogen storage-heat storage units in the form of jackets.

3. The heat self-balancing solid-state hydrogen storage tank according to claim 2, characterized in that: The number of U-shaped tubes inserted in each of the hydrogen storage-heat storage units is the same and is distributed in a circular pattern.

4. The solid-state hydrogen storage tank based on heat self-balancing type according to claim 2, characterized in that: A main air pipe is placed at the center of each hydrogen storage-heat storage unit, and an equal number of branch air pipes are placed around the unit in a circumferential distribution.

5. The solid-state hydrogen storage tank based on heat self-balancing type according to claim 1 is characterized in that: The hydrogen storage layer is filled with metal hydride hydrogen storage material for storing hydrogen; or the heat storage layer is filled with composite phase change material for recovering reaction heat during the hydrogen storage process and utilizing it during the hydrogen release process.

6. The heat self-balancing solid-state hydrogen storage tank according to claim 1, characterized in that: A graphite gasket for sealing is provided at the connection between the flange cover and the tank body.

7. The solid-state hydrogen storage tank based on heat self-balancing type according to claim 1 is characterized in that: A thermocouple inserted into the tank body is welded on the flange cover, and the thermocouple is used to monitor the temperature changes inside the tank body during the storage and discharge of hydrogen; or a pressure sensor and a pressure relief valve are connected to the flange cover, and the pressure sensor is used to detect the changes in the hydrogen pressure in the tank body, and the pressure relief valve is used to relieve the pressure when the pressure in the storage tank exceeds the safety pressure.

8. A heat control method based on a heat self-balancing solid-state hydrogen storage tank according to any one of claims 1 to 7, characterized in that: include: During the hydrogen storage process, hydrogen from the hydrogen source enters the hydrogen storage tank through the gas pipe, diffuses into the hydrogen storage layer, undergoes a hydrogen absorption reaction with the metal hydride hydrogen storage material in the hydrogen storage layer, and releases reaction heat; part of the reaction heat is transferred through the wall between the hydrogen storage layer and the heat storage layer, and the other part is extracted from the hydrogen storage layer by the heat exchange fluid flowing in the U-shaped tube driven by the power pump and transferred to the heat storage layer for storage; Subsequently, during the hydrogen desorption process, in addition to transferring the heat required for the hydrogen desorption reaction through the wall between the hydrogen storage layer and the heat storage layer, the power pump drives the heat exchange fluid to extract the stored reaction heat from the heat storage layer and transfer it to the hydrogen storage layer as a heat source for the hydrogen desorption reaction; the metal hydride hydrogen storage material absorbs heat and undergoes a hydrogen desorption reaction, and the released hydrogen is released from the hydrogen storage tank through the gas duct and supplied to the hydrogen fuel cell as fuel.

9. The heat control method according to claim 8, wherein: When the hydrogen demand is less than the set value or cold start occurs, the power pump is controlled to be closed. At this time, heat exchange is only carried out through the contact surface between the hydrogen storage layer and the heat storage layer in the hydrogen storage tank; when the hydrogen demand is greater than or equal to the set value, the power pump is controlled to be turned on. At this time, heat is transferred collaboratively in the hydrogen storage tank through the circulation of the heat exchange fluid in the U-tube and the contact surface of the hydrogen storage layer.

10. The heat control method according to claim 8, wherein: According to the hydrogen supply rate requirements of the hydrogen fuel cell, the hydrogen outlet pressure and the flow rate of the heat exchange fluid are regulated to meet the hydrogen demand under different working conditions.

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