Low-pressure normal-temperature physical adsorption type hydrogen storage tank

Abstract

The invention provides a low-pressure normal-temperature physical adsorption type hydrogen storage tank, and belongs to the technical field of hydrogen storage equipment, the low-pressure normal-temperature physical adsorption type hydrogen storage tank comprises a fractal flow channel supporting structure, a carbon nano tube block and a sealing tank body, the fractal flow channel supporting structure is arranged in the sealing tank body, and the fractal flow channel supporting structure comprises a main flow channel supporting body and a plurality of branch flow channel supporting bodies; a plurality of branch flow channel supporting bodies are communicated with the main flow channel supporting body, carbon nano tube blocks are arranged on the branch flow channel supporting bodies, the carbon nano tube blocks are in a cup shape, and a hydrogen conveying pipeline and a hydrogen discharging pipeline are arranged at the two ends of the sealed tank body respectively. A coupling system of a fractal flow channel supporting structure and a cup-shaped carbon nano tube module is constructed, hydrogen can be efficiently stored under the normal temperature and low pressure through the physical adsorption effect, the surface of a carbon nano tube can provide a larger surface area, the adsorption sites of the hydrogen can be increased, and the breakthrough improvement of the hydrogen storage performance under the working conditions of low pressure and normal temperature is achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of hydrogen storage equipment, and specifically relates to a low-pressure and normal-temperature physical adsorption type hydrogen storage tank. BACKGROUND

[0002] At present, the hydrogen storage methods mainly include high-pressure hydrogen storage, liquid hydrogen storage and solid hydrogen storage. The high-pressure hydrogen storage needs to be configured with high-cost carbon fiber composite tank body and precise pressure control system, and has safety hazards. The liquid hydrogen storage has an evaporation loss of up to 30% and huge energy consumption due to ultra-low temperature maintenance. The normal-temperature physical adsorption hydrogen storage technology adopts adsorbent materials such as carbon nanotubes or metal organic frameworks (MOFs), and has good hydrogen storage performance, but faces two big bottlenecks. One is that the adsorbent materials cause thermal expansion stress, structure pulverization and cycle life attenuation in the hydrogen absorption and release process due to sharp temperature change. The other is that the existing tank body adopts an adsorbent particle filling type design, and the thermal conductivity is generally lower than 0.5 W / (m·K), so that the adsorption heat cannot be discharged in time. When the environmental temperature is higher than 25 DEG C, the hydrogen storage density decreases by more than 40%, and the hydrogen release rate fluctuates greatly, and the hydrogen release is unstable.

[0003] At the same time, the normal-temperature physical adsorption type hydrogen storage system often faces the problem of large temperature fluctuation, which directly affects the hydrogen adsorption capacity of the adsorbent material and reduces the hydrogen storage efficiency. In addition, a large number of cooling and heating systems are needed to adjust the temperature in the hydrogen charging and discharging process, which increases the complexity and cost of the equipment.

[0004] The material of the hydrogen storage container and the supporting structure is easily affected by hydrogen embrittlement, which may cause hydrogen permeation and leakage, and further reduces the safety and stability of the hydrogen storage system.

[0005] The design of the existing adsorption type hydrogen storage tank is usually complex, and a powder adsorbent is used. Such structure easily causes hydrogen outlet blockage, and may cause the service life of the hydrogen storage tank to be shortened and the hydrogen storage capacity to be significantly reduced. SUMMARY

[0006] In view of the above problems of the prior art, the technical problem to be solved by the embodiments of the present application is to provide a low-pressure and normal-temperature physical adsorption type hydrogen storage tank.

[0007] To solve the above technical problems, the present application provides the following technical scheme: a low-pressure and normal-temperature physical adsorption type hydrogen storage tank, comprising a fractal flow channel supporting structure, a carbon nanotube block and a sealed tank body, the fractal flow channel supporting structure is arranged in the sealed tank body, the fractal flow channel supporting structure comprises a main flow channel supporting body and a plurality of branch flow channel supporting bodies, the plurality of branch flow channel supporting bodies are communicated with the main flow channel supporting body, and the main flow channel supporting body is connected with an external medium circulating system.

[0008] The branch flow channel support body is provided with a carbon nanotube block in a cup cover shape, and the tank body is provided with a hydrogen input pipeline and a hydrogen output pipeline at two ends respectively.

[0009] As a further improvement: the sealed tank body comprises an inner shell and an outer shell, and a heat insulation layer is arranged between the two shells.

[0010] As a further improvement: the fractal flow channel support structure is in a tree-shaped support structure.

[0011] As a further improvement: the outer wall of the flow channel support body and the branch flow channel support body is coated with a heat conduction layer.

[0012] As a further improvement: the heat conduction layer material is a resin and graphene composite material.

[0013] As a further improvement: the carbon nanotube is subjected to compaction treatment.

[0014] As a further improvement: the flow channel support body and the branch flow channel support body are copper pipes.

[0015] Compared with the prior art, the beneficial effects of the present application are: by utilizing the excellent hydrogen absorption capacity of the cup cover-shaped carbon nanotube, a fractal flow channel support structure and a cup cover-shaped carbon nanotube module coupling system are innovatively constructed, the cup cover-shaped carbon nanotube as a hydrogen storage material has a unique multi-layer structure and can store hydrogen gas efficiently at normal temperature and low pressure through physical adsorption, and its unique microstructure, especially its cup-shaped structure, can provide a larger surface area and increase the hydrogen adsorption sites on the surface of the carbon nanotube, thereby achieving a breakthrough in hydrogen storage performance at low pressure and normal temperature, and improving the existing hydrogen storage technology. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of a low-pressure and normal-temperature physical adsorption type hydrogen storage tank.

[0017] Figure 2 It is an enlarged view of A of a low-pressure and normal-temperature physical adsorption type hydrogen storage tank.

[0018] In the figure: 1, carbon nanotube block; 2, fractal flow channel support structure; 3, inner shell; 4, hydrogen input pipeline; 5, hydrogen output pipeline; 6, cold and hot medium input port; 7, heat insulation layer; 8, outer shell; 9, cold and hot medium output port; 11, heat conduction layer; 21, branch flow channel support body. DETAILED DESCRIPTION

[0019] The technical solutions of the present application will be further described in detail below in combination with specific embodiments.

[0020] Embodiments of the present application are described below in detail with reference to the accompanying drawings, wherein like or similar elements are denoted by the same or similar reference signs throughout the drawings. The embodiments described below are exemplary only, and are not intended to limit the present application.

[0021] Please refer to Figure 1 , Figure 2 In one embodiment, a low-pressure and normal-temperature physical adsorption hydrogen storage tank includes a fractal flow channel support structure 2, a carbon nanotube block 1, and a sealed tank body, the fractal flow channel support structure 2 is arranged in the sealed tank body, the fractal flow channel support structure 2 includes a main flow channel support body and a plurality of branch flow channel support bodies 21, the plurality of branch flow channel support bodies 21 are in communication with the main flow channel support body, and the main flow channel support body is connected to an external medium circulation system.

[0022] The carbon nanotube block 1 is arranged on the branch flow channel support body 21, the carbon nanotube block 1 is in the form of a cup cover, and the sealed tank body is respectively provided with a hydrogen input pipeline 4 and a hydrogen output pipeline 5 at two ends.

[0023] In the embodiment, one end of the branch flow channel support body 21 is provided with a cold and hot medium input port 6, the other end of the branch flow channel support body 21 is provided with a cold and hot medium output port 9, and the flow direction of the cold and hot medium is from the cold and hot medium input port 6 to the main flow channel to the cold and hot medium output port 9.

[0024] The low pressure is in the pressure range of normal pressure to 10 MPa, the mass hydrogen storage capacity of the carbon nanotube block 1 should be greater than 2 wt%, and the carbon nanotube block 1 should be not less than 30 cm*30 cm*10 cm.

[0025] The cup cover-shaped carbon nanotube block 1 is used as an adsorption material block, which fully plays its excellent hydrogen adsorption performance. The cup cover-shaped carbon nanotube (CSCNTs) is different from the seamless cylindrical carbon nanotube (CNTs) composed of a hexagonal carbon net, and is stacked by single and truncated graphene layers. This non-continuous stacking structure exposes a large number of edge sites with high activity inside and outside the tube wall, accompanied by significant dangling bonds. This special geometry significantly increases the surface area, thereby providing more hydrogen adsorption sites and greatly improving the physical adsorption capacity of hydrogen. Under 10 MPa, the cscnts loaded with nanometer metal particles have a mass hydrogen storage fraction of 4.6 wt%, and the original bulk density of the cup cover-shaped carbon nanotube is 20 kg / m 3, the porosity is as high as 99%, which provides sufficient space for hydrogen storage and facilitates efficient hydrogen adsorption at normal temperature and low pressure. Furthermore, the hydrogen storage capacity of the original cup-shaped carbon nanotubes can be further improved by adjusting the structure of carbon nanotubes, activation modification, and loading of nano-metal particles. In terms of the morphology of the adsorbent material, the compact adsorption layer is formed by compacting the cup-shaped carbon nanotubes, which significantly improves the bulk density to 1700 kg / m 3 This high-density adsorption layer can further enhance the physical adsorption capacity of hydrogen, especially at low pressure and normal temperature, ensuring the stability and efficiency of hydrogen storage performance. The compact structure of the carbon nanotube block after pressing can effectively reduce the free flow of hydrogen in the adsorption layer, improve the storage density of hydrogen, and optimize the stability of the adsorption layer.

[0026] The density and hydrogen storage capacity of the carbon nanotube block 1 are improved by using die casting technology to ensure efficient hydrogen storage at normal temperature and low pressure. The multi-layer structure of the carbon nanotubes significantly increases the adsorption sites, and the hydrogen adsorption capacity is further improved by activation and metal loading. Through compaction treatment, the hydrogen storage density is also optimized and the risk of structure pulverization is reduced.

[0027] During the hydrogen storage and release process, the cold and hot medium flow system can stably regulate the temperature in the tank to ensure stable storage and release of hydrogen, avoiding the negative effects of temperature changes.

[0028] Hydrogen storage is carried out at low pressure and normal temperature, avoiding the high-cost equipment and high-energy consumption requirements of high-pressure hydrogen storage systems and liquid hydrogen storage systems. In addition, by optimizing the structural design of the hydrogen storage tank, the number of cooling and heating equipment in the system is reduced, reducing the complexity and cost of the overall system.

[0029] Please refer to Figure 1 , Figure 2 In one embodiment, the sealed tank body includes an inner shell 3 and an outer shell 8, and a thermal insulation layer 7 is arranged between the two shells.

[0030] In one embodiment, the flow channel support body and the branch flow channel support body are copper pipes.

[0031] In this embodiment, the flow channel support body and the branch flow channel support body can also use other metal pipes for the circulation of cold and hot media.

[0032] Please refer to Figure 1 , Figure 2 In one embodiment, the fractal flow channel support structure 2 presents a tree-shaped support structure.

[0033] In this embodiment, in the tree-shaped support structure, the "trunk" serves as the main flow channel for cold and hot media, and the "branches" serve as branch flow channels for cold and hot media, which are responsible for providing cold and hot media for each "branch", ensuring the thermal management of the hydrogen storage tank during the hydrogen filling and dehydrogenation process, and avoiding the impact of temperature fluctuations on hydrogen storage and release. A die-cast cup-shaped carbon nanotube block 1 is placed on each "branch". These carbon nanotube blocks 1 serve as hydrogen adsorbents and can efficiently store hydrogen under normal temperature and low pressure conditions.

[0034] In one embodiment, the outer walls of the flow channel support body and the branch flow channel support body are coated with a heat conductive layer 11 .

[0035] In this embodiment, in order to further enhance the performance of the fractal flow channel support structure 2, the flow channel support body and the branch flow channel support body are coated with high thermal conductivity materials, which effectively improves the thermal conductivity, avoids the adverse effects of temperature control, prevents hydrogen embrittlement, and extends the service life of the hydrogen storage tank.

[0036] In one embodiment, the heat conducting layer 11 is made of a composite material of resin and graphene.

[0037] In this embodiment, the outer wall is coated with a resin and graphene composite material. This coating material serves a dual purpose: on the one hand, the resin and graphene composite coating effectively prevents hydrogen embrittlement of the copper tube support structure and pipeline, thereby extending the service life of the hydrogen storage tank; on the other hand, the coating material greatly enhances the thermal conductivity of the copper tube, allowing the cold medium to efficiently remove the adsorbed heat generated during hydrogen storage, and conversely, the hot medium can more quickly provide the required temperature for the hydrogen release process.

[0038] During the hydrogen storage process, when hydrogen is adsorbed, the adsorption material releases a certain amount of adsorption heat, causing the material temperature to rise. The copper tube "branches" then pass a cold medium (such as a coolant at 10°C to 25°C) through them to effectively remove the heat generated during the adsorption process, maintaining a stable temperature within the hydrogen storage tank and preventing a decrease in hydrogen adsorption capacity and material structural instability due to excessive temperatures. The flow of the cold medium not only helps maintain the hydrogen storage tank's temperature control but also prevents a decrease in hydrogen storage efficiency due to excessive temperature fluctuations. During the dehydrogenation process, when hydrogen needs to be released, the copper tube "branches" pass a hot medium (a heating liquid at 40°C to 80°C) through them to provide sufficient temperature for the adsorption material within the tank, promoting the release of hydrogen from the carbon nanotube adsorption sites. The hot medium efficiently heats the adsorption material, assisting hydrogen desorption and improving desorption efficiency. By switching and circulating the hot and cold media, the hydrogen storage tank's hydrogen absorption and desorption processes are effectively temperature-regulated, ensuring efficient and stable hydrogen storage and release.

[0039] By using the excellent hydrogen absorption capacity of cup-shaped carbon nanotubes (CSCNTs), a novel coupling system of tree-shaped copper tube support skeleton and cup-shaped carbon nanotube module is constructed, and a high-efficiency heat conduction-hydrogen barrier is established by graphene reinforced resin coating technology. As a hydrogen storage material, cup-shaped carbon nanotubes have a unique multi-layer structure and can store hydrogen efficiently at room temperature and low pressure through physical adsorption. The unique microstructure of cup-shaped carbon nanotubes, especially the cup-shaped structure, can provide a larger surface area and increase the adsorption sites of hydrogen. After powder die casting, the hydrogen adsorption capacity is significantly improved, and the risk of structure powdering is reduced. The hydrogen storage performance is significantly improved at low pressure and room temperature, and the existing hydrogen storage technology is improved.

[0040] It is apparent for those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, but can be implemented in other concrete forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all respects as illustrative and not restrictive, the scope of the present application being defined by the appended claims rather than the above description, and it is intended to include all changes falling within the meaning and scope of the equivalent elements of the claims, and no figure reference in the claims should be considered as limiting the scope of the claims.

[0041] Furthermore, it should be understood that, although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be combined appropriately to form other embodiments that those skilled in the art can understand.

Claims

1. A low-pressure, room-temperature physical adsorption hydrogen storage tank, characterized in that: It includes a fractal flow channel support structure, a carbon nanotube block and a sealed tank body. The sealed tank body is provided with a fractal flow channel support structure. The fractal flow channel support structure includes a main flow channel support body and a plurality of branch flow channel support bodies. The plurality of branch flow channel support bodies are connected to the main flow channel support body. The main flow channel support body is connected to an external medium circulation system. A carbon nanotube block is arranged on the branch flow channel support body, and the carbon nanotube block is in a cup shape. A hydrogen delivery pipeline and a hydrogen discharge pipeline are respectively arranged at both ends of the sealed tank body.

2. A low-pressure, room-temperature physical adsorption hydrogen storage tank according to claim 1, characterized in that: The sealed tank body comprises an inner shell and an outer shell, and a heat insulation layer is arranged between the two shells.

3. A low-pressure, room-temperature physical adsorption hydrogen storage tank according to claim 1, characterized in that: The fractal flow channel support structure presents a tree-shaped support structure.

4. A low-pressure, room-temperature physical adsorption hydrogen storage tank according to claim 1, characterized in that: The outer walls of the flow channel support body and the branch flow channel support body are coated with a heat conductive layer.

5. A low-pressure, room-temperature physical adsorption hydrogen storage tank according to claim 4, characterized in that: The heat-conducting layer material is a resin and graphene composite material.

6. A low-pressure, room-temperature physical adsorption hydrogen storage tank according to claim 1, characterized in that: The carbon nanotubes are compacted.

7. A low-pressure, room-temperature physical adsorption hydrogen storage tank according to claim 1, characterized in that: The flow channel support body and the branch flow channel support body are copper tubes.

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