Hydrogen storage device, hydrogen storage well and conditioning method for hydrogen storage well

Abstract

The application provides a hydrogen storage device, which comprises a well shaft capable of being put into a base well of a hydrogen storage well, an annular fixing seat used for setting a well mouth of the base well, and a first joint, which comprises a supporting seat used for being engaged with the annular fixing seat, wherein the well shaft is configured as a continuous well shaft made of a fiber-wound flexible composite material, and the fiber-wound flexible composite material comprises an inner anti-seepage layer, a reinforcing layer and an outer protective layer. The application can set the well shaft as an integrally-formed structure, thereby eliminating the problem of setting a plurality of connecting joints on the well shaft itself, and effectively improving the safety of the hydrogen storage well. In addition, the application further provides a hydrogen storage well and an adjusting method for the hydrogen storage well.

Description

Technical Field

[0001] This invention relates to the field of hydrogen storage equipment technology, specifically to a hydrogen storage device, a hydrogen storage well, and a regulation method for the hydrogen storage well. Background Technology

[0002] Hydrogen energy is a clean and efficient energy source and an important pathway for energy transformation and upgrading, as well as for achieving green development. Hydrogen storage is a crucial link in the development of the hydrogen energy industry. Currently, hydrogen storage methods include gaseous hydrogen storage, liquid hydrogen storage, and solid hydrogen storage. Among these, high-pressure gaseous hydrogen storage is the most common method, primarily using high-pressure hydrogen storage cylinders as the storage containers.

[0003] CN215949579U provides an underground hydrogen storage well, comprising a wellhead at the bottom, a well casing connected to the top of the wellhead, and a well tail connected to the top of the well casing. The lower section of the wellhead gradually tapers downwards, forming a drill bit. The tops of the wellhead and well casing are respectively provided with sockets, and the bottoms of the well casing and well tail are respectively provided with insertion ports. The sockets and insertion ports are fitted with regular polygonal structures. The top of the wellhead, the bottom of the well casing, and the top and bottom of the well tail are respectively provided with connecting parts on their outer walls, and the corresponding connecting parts are fixed together by bolts. Therefore, comparison shows that hydrogen storage wells have multiple advantages over hydrogen storage cylinders, including smaller footprint and higher safety.

[0004] While the aforementioned hydrogen storage well offers greater safety and a smaller footprint for hydrogen storage, it is primarily constructed of metal and connected by multiple sections of metal pipe. Because a metal hydrogen storage well requires multiple pipe connections, a large number of joints are unavoidable. These joints are prone to leaks and corrosion, posing a serious safety hazard to the long-term operation of the entire hydrogen storage well.

[0005] Therefore, it is desirable to propose a hydrogen storage device to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a hydrogen storage device that features a one-piece molded wellbore, eliminating the need for joints on the wellbore itself and thus effectively improving the safety of the hydrogen storage well. Furthermore, since the wellbore in this invention is made of fiber-wound flexible composite material, leakage problems caused by wellbore corrosion are effectively solved. This invention also provides a hydrogen storage well and a method for regulating the hydrogen storage well.

[0007] According to a first aspect of the present invention, a hydrogen storage device is provided, comprising a wellbore capable of being inserted into a base well for containing hydrogen gas; an annular fixing seat for mounting the wellhead of the base well; and a first joint for sealing connection with the upstream end of the wellbore, the first joint including a support seat for engaging with the annular fixing seat; wherein the wellbore is configured as a continuous wellbore made of a fiber-wound flexible composite material, the fiber-wound flexible composite material including an inner impermeable layer, a reinforcing layer, and an outer protective layer arranged radially in sequence.

[0008] In one embodiment, the inner impermeable layer comprises at least one of non-metallic and metal-non-metallic composite layers, the reinforcing layer comprises at least one of glass fiber, carbon fiber, metal wire and nylon fiber, and the outer protective layer comprises at least one of PE, PVDF and PA.

[0009] In one embodiment, the hydrogen storage device further includes a delivery mechanism sleeved outside the wellbore. The delivery mechanism includes an airbag and centralizers respectively disposed upstream and downstream of the airbag. The centralizers are provided with a plurality of rollers for engaging with the inner wall of the base well.

[0010] In one embodiment, a plurality of the dispensing mechanisms are arranged at equal intervals along the axial direction of the hydrogen storage device.

[0011] In one embodiment, the hydrogen storage device further includes a second connector that is sealed to the downstream end of the wellbore, and a buffer disposed downstream of the second connector, the buffer being configured to abut against the bottom of the base well.

[0012] In one embodiment, the hydrogen storage device further includes a first valve disposed on the support base, and a first connecting pipe extending through the first valve and communicating with each of the gasbags, for supplying gas to the gasbags to allow the gasbags to be seated within the base well.

[0013] In one embodiment, the hydrogen storage device further includes a second valve disposed on the support base, and a second connecting pipe passing through the second valve and extending into the annulus between the base well and the wellbore, for displacing oxygen in the annulus.

[0014] In one embodiment, the hydrogen storage device further includes a third valve and a third connecting pipe, both arranged on the support, wherein the third connecting pipe is configured to communicate with the second connecting pipe through the third valve, thereby allowing gas in the annulus to flow to the outside through the third connecting pipe.

[0015] In one embodiment, the hydrogen storage device further includes a first interface and a second interface disposed on the first connector for guiding hydrogen, and a fourth connecting pipe, wherein a first end of the fourth connecting pipe is fixedly connected to the second interface, and a second end extends to the bottom of the wellbore.

[0016] In one embodiment, the hydrogen storage device further includes a safety valve disposed on the first connector and a pressure sensor disposed within the support.

[0017] According to a second aspect of the invention, a hydrogen storage well is provided, comprising a base well and a hydrogen storage device as described above disposed in the base well.

[0018] According to a third aspect of the present invention, a method for regulating a hydrogen storage well as described above is provided, comprising the following steps: S1, placing the assembled hydrogen storage device into the base well; S2, replacing the oxygen in the annulus between the base well and the wellbore with an inert gas through a second connecting pipe and a third connecting pipe; S3, closing the second interface and filling the wellbore with hydrogen gas through the first interface; S4, monitoring the pressure of hydrogen gas seeping into the annulus from the wellbore through a pressure sensor, and opening the third valve when the pressure reaches the limit value of the pressure sensor, so that the seeping hydrogen gas is discharged to the outside through the third connecting pipe.

[0019] In one embodiment, the cross-sectional area of ​​the wellbore accounts for 60-90% of the cross-sectional area of ​​the base well.

[0020] Compared with existing technologies, the advantages of this invention are as follows: This invention enables the wellbore to be designed as a single-piece structure, thus eliminating the need for joints on the wellbore itself and effectively improving the safety of the hydrogen storage well. The wellbore of this invention is made of fiber-wound flexible composite material, which effectively prevents leakage caused by hydrogen corrosion of the wellbore. This invention also uses airbags instead of cement slurry to restrict the position of the wellbore, and the combination of the second and third connecting pipes enables real-time adjustment of the gas in the annulus, ensuring that the pressure in the annulus remains within a controllable range, further improving the safety of the hydrogen storage well. Furthermore, compared to hydrogen storage wells made of metal, this invention can achieve higher storage pressure, thus providing a higher hydrogen storage density. Attached Figure Description

[0021] The invention will now be described in detail with reference to the accompanying drawings, in which:

[0022] Figure 1 The schematic diagram illustrates the structure of a hydrogen storage well according to the present invention, showing the positional relationship between the hydrogen storage device and the base well.

[0023] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not drawn to scale.

[0024] The meanings of the reference numerals in the attached figures are as follows:

[0025] 10 base well,

[0026] 11. Circular fixing seat

[0027] 12 rings,

[0028] 20 shafts,

[0029] 21 delivery agencies,

[0030] 211 airbags

[0031] 212 centralizer

[0032] 213 rollers

[0033] 22 First joint,

[0034] 221 support base

[0035] 23 Second connector

[0036] 24 buffers

[0037] 30 First valve

[0038] 31 First connecting pipe,

[0039] 40 Second valve

[0040] 41 Second connecting pipe,

[0041] 50 Third Valve

[0042] 51 Third connecting pipe,

[0043] 60 First Interface

[0044] 61 Second Interface

[0045] 62 Fourth connecting pipe,

[0046] 70 safety valve

[0047] 100 hydrogen storage device

[0048] 200 hydrogen storage wells Detailed Implementation

[0049] The invention will now be further described with reference to the accompanying drawings.

[0050] Figure 1The schematic diagram illustrates the structure of a hydrogen storage well 200 according to the present invention, showing the positional relationship between the hydrogen storage device 100 and the base well 10.

[0051] like Figure 1 As shown, according to one aspect of the present invention, a hydrogen storage device 100 is provided, mainly comprising a wellbore 20 for storing hydrogen. The wellbore 20 is constructed as a continuous wellbore and can be inserted into a base well 10, thereby forming a hydrogen storage well 200 (described below) together with the base well 10. Compared with hydrogen storage wells in the prior art that are connected by multiple pipelines, the wellbore 20 of the present invention has better continuity and does not require frequent connection and disassembly when inserted into the base well 10, thereby effectively improving work efficiency. In addition, since the wellbore 20 of the present invention is a one-piece molded structure, the number of sealing points is greatly reduced, thereby effectively eliminating the safety hazards caused by corrosion and leakage at joints in hydrogen storage wells in the prior art, and further effectively improving the safety of the hydrogen storage well 200.

[0052] According to the present invention, the hydrogen storage device 100 further includes a first connector 22. The first connector 22 is sealed to the upstream end of the wellbore 20 and is used to control the input and output of hydrogen in the wellbore 20, the details of which are described below. In addition, a support seat 221 is provided on the first connector 22, and the support seat 221 is arranged to extend radially outward, so that when the hydrogen storage device 100 is put into the base well 10, it can effectively engage with the annular fixing seat 11 (described below).

[0053] According to one embodiment of the present invention, an annular fixing seat 11 is provided on the wellhead of the base well 10. Therefore, when the hydrogen storage device 100 is inserted into the base well 10 of the hydrogen storage well 200, the well shaft 20 can form a sealed connection with the annular fixing seat 11 through the support seat 221, thereby achieving a complete seal of the base well 10. In this way, the hydrogen storage well 200 has higher safety compared to a hydrogen storage cylinder.

[0054] According to the present invention, such as Figure 1As shown, the well casing 20 is made of fiber-wound flexible composite material. Fiber-wound flexible composite material possesses excellent high-pressure resistance and flexibility. In this way, on the one hand, it can provide a good hydrogen storage environment, thereby improving the safety of the hydrogen storage well 200. On the other hand, due to the good flexibility and integral molding structure of the well casing 20, it can be transported in a coiled manner, thereby improving transportation efficiency and reducing the footprint of the well casing 20, effectively saving transportation costs. Furthermore, because the well casing 20 has an integral molding structure, the number of sealing points is significantly reduced, effectively eliminating the safety hazards caused by corrosion and leakage at joints in existing well casings, thus effectively improving the safety of the hydrogen storage well 200.

[0055] According to the present invention, the fiber-wound flexible composite material comprises an inner impermeable layer (not shown), a reinforcing layer (not shown), and an outer protective layer (not shown) arranged radially in sequence. Specifically, the inner impermeable layer, the reinforcing layer, and the outer protective layer are arranged sequentially from the inside to the outside of the wellbore 20. The action of these three layers effectively reduces the hydrogen leakage rate and increases the service life of the hydrogen storage device 100, further improving the safety of the hydrogen storage well 200. This is described below.

[0056] According to one embodiment of the present invention, the internal impermeable layer described above includes at least one of non-metallic and metal-non-metallic composite layers. Thus, because the impermeable layer employs a high gas barrier non-metallic or metal-non-metallic composite layer structure (e.g., montmorillonite-modified PE, graphene-modified PE, metal-coated composite PE, etc.), it effectively slows down hydrogen permeation and leakage, thereby reducing the possibility of safety hazards within the hydrogen storage well 200 meters, and further providing a safer storage space for hydrogen.

[0057] According to one embodiment of the present invention, the reinforcing layer described above comprises at least one of glass fiber, carbon fiber, metal wire, and nylon fiber. Thus, the pressure resistance of the hydrogen storage well is effectively improved by the reinforcing layer, and the reinforcing layer is unaffected by high-pressure hydrogen, further enhancing the safety of the hydrogen storage well 200.

[0058] According to one embodiment of the present invention, the external protective layer as described above includes at least one material selected from PE, PVDF, PA, etc. Thus, the internal impermeable layer and reinforcing layer can function under the protection of the external protective layer. Simultaneously, the presence of the external protective layer extends the service life of the hydrogen storage device 100 to a certain extent, thereby effectively reducing subsequent labor costs, operating costs, and maintenance costs.

[0059] According to the present invention, the hydrogen storage device 100 further includes a plurality of delivery mechanisms 21 sleeved around the wellbore 20. Each delivery mechanism 21 includes an airbag 211 and a centralizer 212. The airbag 211 is configured to expand radially outward after gas is supplied through the first connecting pipe 31 (described below), thereby settling within the base well 10. The centralizers 212 are respectively arranged upstream and downstream of the airbag 211, thereby providing a certain degree of restraint to the expanded airbag 211. Furthermore, the centralizer 212 also includes rollers 213 extending radially outward. When the wellbore 20 is inserted into the base well 10, the centralizer 212 can abut against the inner wall of the base well 10 via the rollers 213, thereby smoothly delivering the wellbore 20 to the bottom of the base well 10. Since the present invention uses the airbag 211 setting method instead of the cement grout fixing method in the prior art, the hydrogen storage device 100 can be more easily installed and disassembled in the base well 10.

[0060] In one embodiment of the present invention, an anti-slip layer (not shown) is also arranged on the outer wall surface of the airbag 211, so that after setting, the friction between the airbag and the base well 10 can be effectively increased, thereby ensuring that the wellbore 20 can always be in a stable state.

[0061] According to one embodiment of the present invention, a plurality of delivery mechanisms 21 are evenly distributed along the axial direction on the wellbore 20. In this way, on the one hand, the hydrogen storage device 100 can always remain in a stable state during its movement within the base well 10, thereby ensuring that the wellbore 20 can smoothly enter the bottom of the base well 10. On the other hand, the setting action of a plurality of airbags 211 ensures that the wellbore 20 can always maintain a stable working state.

[0062] According to the present invention, the hydrogen storage device 100 further includes a second connector 23 and a buffer 24. The second connector 23 is sealed to the downstream end of the wellbore 20, thereby providing a certain degree of sealing for the wellbore 20. The buffer 24 is disposed downstream of the second connector 23 and is fixedly connected to the second connector 23. When the hydrogen storage device 100 is inserted into the base well 10 and moves to the bottom of the base well 10, the buffer 24 abuts against the bottom of the base well 10, thereby effectively buffering the wellbore 20 and further protecting the overall structure of the wellbore 20. Furthermore, the buffer 24 cooperates with the support base 221, and both simultaneously provide protection for the overall structure of the wellbore 20. The buffer 24 is well known to those skilled in the art and therefore will not be described in detail.

[0063] It is easy to understand that, in order to ensure the sealing of the wellbore 20, both the first joint 22 and the second joint 23 adopt a multi-stage sealing structure.

[0064] According to the present invention, the hydrogen storage device 100 further includes a first valve 30 and a first connecting pipe 31. The first valve 30 is disposed on the support base 221. The first connecting pipe 31 extends through the first valve 30 and is effectively connected to each of the gas bags 211. Thus, when the hydrogen storage device 100 is inserted into the base well 10 and moves to the bottom of the base well 10, gas can be injected into each of the gas bags 211 through the first connecting pipe 31, causing each gas bag 211 to expand radially outward, thereby causing the wellbore 20 to be seated and sealed within the base well 10 under the action of the gas bags 211. Since the overall length of the wellbore 20 in the present invention is relatively long, this method can effectively limit the various parts of the wellbore 20 in the axial direction, thereby ensuring a stable state of the hydrogen storage device 100 during hydrogen storage and further providing a safer storage environment for hydrogen.

[0065] According to the present invention, the hydrogen storage device 100 further includes a second valve 40 and a second connecting pipe 41. The second valve 40 is disposed on a support base 221. The second connecting pipe 41 passes through the second valve 40 and extends into the annulus 12 between the base well 10 and the wellbore 20. Specifically, the end of the second connecting pipe 41 extends to the bottom of the base well 10. Thus, when the wellbore 20 is seated within the base well 10 under the action of the gasbag 211, an inert gas (e.g., nitrogen) can be injected into the annulus 12 through the third connecting pipe 51 (described below), thereby fully replacing the oxygen in the annulus 12 through the second connecting pipe 41. In this way, the amount of oxygen in the annulus 12 drops sharply, thereby effectively improving the safety of the hydrogen storage well 200. According to an embodiment of the present invention, the second connecting pipe 41 is preferably a continuous flexible non-metallic pipe.

[0066] According to the present invention, the hydrogen storage device 100 further includes a third valve 50 and a third connecting pipe 51. The third valve 50 is disposed on the support base 221. The third connecting pipe 51 is disposed on the support base 221 and communicates with the second connecting pipe 41 via the third valve 50. Thus, when nitrogen is injected into the annulus 12 through the third connecting pipe 51, oxygen in the annulus 12 can be discharged to the outside through the second connecting pipe 41 under the impetus of the nitrogen, thereby effectively removing oxygen from the annulus 12 and reducing the possibility of hydrogen overflowing from the wellbore 20 combining with oxygen in the annulus 12, further improving the safety of the hydrogen storage well 200.

[0067] According to one embodiment of the present invention, the third connecting pipe 51 has two functions. Firstly, the third connecting pipe 51 can be used in conjunction with the second connecting pipe 41 to achieve complete replacement of oxygen in the annulus 12 or extraction of gas from the annulus 12 for gas composition detection. Secondly, when hydrogen seeps out or leaks locally from the wellbore 20, causing an increase in gas pressure within the annulus 12, the third valve 50 can open rapidly, allowing the hydrogen in the annulus 12 to be fully and quickly released through the third connecting pipe 51, thereby effectively eliminating potential safety hazards within the hydrogen storage well 200.

[0068] According to one embodiment of the present invention, since the oxygen in the base well 10 generally settles at the bottom of the base well 10, the bottom gas can be extracted through the end of the second connecting pipe 41, while nitrogen is injected through the third connecting pipe 51. Specifically, the nitrogen injected through the third connecting pipe 51 can compress the oxygen in the annulus, thereby promoting the oxygen to be discharged more quickly through the second connecting pipe 41, thus fully and comprehensively replacing the oxygen in the annulus 12, thereby effectively improving the overall safety of the hydrogen storage well 200.

[0069] According to the present invention, the hydrogen storage device 100 further includes a first interface 60, a second interface 61, and a fourth connecting pipe 62. The first interface 60 is disposed on the first connector 22 for injecting hydrogen into the wellbore 20. The second interface 61 is disposed on the first connector 22 for extracting hydrogen from the wellbore 20. The fourth connecting pipe 62 is disposed inside the wellbore 20, with its first end connected to the second interface 61 and its second end extending to the bottom of the wellbore 20, thereby facilitating gas replacement within the wellbore 20. According to one embodiment of the present invention, the fourth connecting pipe 62 is preferably a continuous flexible non-metallic pipe.

[0070] According to the present invention, a pressure sensor communicating with a third valve 50 is provided inside the support base 221. This pressure sensor can monitor in real time the pressure of hydrogen seeping from the wellbore 20 into the annulus 12, and opens the third valve 50 when the pressure reaches the limit set by the pressure sensor, thereby allowing the hydrogen seeping into the annulus 12 to be discharged through the third connecting pipe 51. In this way, the hydrogen seeping into the annulus 12 can be effectively released, thus avoiding safety accidents caused by the inability to timely discharge the seeping hydrogen from the hydrogen storage well 200. Compared with the prior art method of sealing the annulus with cement, the layout adopted in this invention has better effects and can more effectively and quickly discharge the overflowing hydrogen, thereby effectively improving the safety of the hydrogen storage well 200.

[0071] According to the present invention, a safety valve 70, a temperature sensor, and a pressure sensor are also provided on the first connector 22. The temperature sensor can monitor the temperature inside the wellbore 20 in real time; the pressure sensor can monitor the pressure inside the wellbore 20 in real time. The safety valve 70 is mainly for emergency release inside the wellbore 20, thereby avoiding serious accidents caused by excessive gas pressure inside the wellbore 20.

[0072] The aforementioned emergency release scenarios generally fall into two categories. First, when the gas pressure inside the wellbore 20 exceeds the limit of safety valve 70, safety valve 70 will release gas in an emergency. Second, when the third connecting pipe 51 releases hydrogen from the annulus 12, and the gas pressure inside the annulus 12 still exceeds the pressure limit of the pressure sensor located in the support 221, an emergency release will be initiated.

[0073] According to one embodiment of the present invention, when the leakage rate of hydrogen in the wellbore 20 is greater than the release rate of the third connecting pipe 51, and the pressure sensor arranged in the support 221 detects that the pressure value in the annulus 12 has reached the limit, it is necessary to open the second valve 40, the third valve 50, the first interface 60, the second interface 61 and the safety valve 70 to perform emergency pressure relief to ensure the safety of the hydrogen storage well 200.

[0074] According to a second aspect of the invention, a hydrogen storage well 200 is provided. The hydrogen storage well 200 includes a base well 10 and a hydrogen storage device 100 as described above disposed within the base well 10. The hydrogen storage device 100 is configured to be inserted into the base well 10 and, together with the base well 10, form the hydrogen storage well 200, thereby providing a safe and stable storage environment for hydrogen.

[0075] According to a third aspect of the present invention, a method for regulating a hydrogen storage well 200 as described above is provided, comprising the following steps:

[0076] First, the assembled hydrogen storage device 100 is placed into the base well 10. At this time, the support 221 is sealed to the annular fixed seat 11, and the buffer 24 abuts against the bottom of the base well 10.

[0077] Then, the wellbore 20 is subjected to an airtightness test to ensure that it has good sealing performance.

[0078] Then, inert gas is injected into the annulus 12 between the wellbore 20 and the base well 10 through the third connecting pipe 51, and the oxygen in the annulus 12 is replaced by the inert gas.

[0079] Then, hydrogen is injected into the wellbore 20 through the first interface 60. After the sample analysis results from the second interface 61 are qualified, the second interface 61 is closed, and the hydrogen pressure and temperature in the wellbore 20 are monitored. Once the required pressure is reached, the first interface 60 is closed.

[0080] Finally, the pressure of hydrogen seeping from the wellbore 20 into the annulus 12 is monitored by a pressure sensor arranged in the support 221. When the pressure value reaches the limit of the pressure sensor, the third valve 50 is opened, and the seeping hydrogen is discharged to the outside through the third connecting pipe 51, so that the pressure in the annulus 12 can always be kept under control.

[0081] Furthermore, at the construction site, a single hydrogen storage well can be used, or multiple hydrogen storage wells can be formed into a hydrogen storage well group, or hydrogen storage wells can be combined with hydrogen storage tanks to form a combination of high, medium, and low-pressure hydrogen storage containers. When transporting hydrogen to external locations, it is only necessary to fill the hydrogen fuel cell vehicle or the container requiring hydrogen with the rated pressure through a pressure reducing valve or a sequence control panel.

[0082] According to one embodiment of the present invention, the cross-sectional area of ​​the wellbore 20 accounts for 60-90% of the cross-sectional area of ​​the base well 10. In this way, hydrogen gas seeping from the wellbore 20 can enter the nitrogen-filled annulus 12, and then be quantitatively discharged to the outside under the action of the third valve 50 and the third connecting pipe 51. Compared with injecting cement into the annulus 12, the present invention can effectively improve the safety of the hydrogen storage well 200 by suppressing hydrogen gas with inert gas. Furthermore, the pressure sensor arranged in the support 221 can monitor the pressure of the hydrogen gas seeping into the annulus 12 in real time, thereby opening the third valve 50 and discharging hydrogen gas to the outside through the third connecting pipe 51 when the pressure reaches a limit, thus completing the pressure relief operation of the annulus 12 and further improving the safety of the hydrogen storage well 200.

[0083] It is easy to understand that fiber-wound composite materials have high pressure resistance and do not have the heat treatment problems of thick-walled metals. In addition, since the fiber reinforcement layer material used for pressure bearing does not suffer from hydrogen embrittlement and corrosion, well casings made of non-metallic materials can have higher safety and reliability.

[0084] Due to the unique properties of hydrogen, hydrogen atoms can permeate through the well wall and reach the outer wall to form hydrogen gas. Therefore, existing technologies present three main problems in addressing this issue. First, the formed hydrogen gas can cause the cement on the outside of the tube bundle to peel off from the vessel wall, leading to a sudden increase in local pressure and causing the cement to crack, allowing hydrogen gas to escape along the cracks. The escaped hydrogen gas can easily cause a serious fire. Furthermore, external moisture can also enter the gap between the tube wall and the cement along the cracks, causing well wall corrosion. Second, since existing gas storage wells are typically made of metal, hydrogen penetration into the metal leads to a deterioration of the metal's mechanical properties, resulting in reduced corrosion resistance. Third, metal gas storage wells generally have relatively low pressures. Therefore, when the pressure is high, the well wall of a metal gas storage well needs to be thickened, placing higher demands on connection reliability and heat treatment processes. (Metal gas storage wells typically cannot store hydrogen under pressures exceeding 50 MPa).

[0085] However, the present invention can solve all the aforementioned problems. First, the present invention replaces cement injection by sealing the wellbore 20 within the base well 10 with an airbag 211, thus allowing the generated hydrogen gas to be discharged in a timely manner, thereby effectively improving the safety of the hydrogen storage well 200. Second, the wellbore 20 in the present invention is made of fiber-wound composite material. Since fiber-wound composite material is a non-metallic material, the corrosion problem is solved from a material perspective. Third, the fiber-wound composite material used in the wellbore 20 of the present invention has extremely high pressure resistance and does not present the heat treatment problems of thick-walled metals. In addition, since the fiber reinforcement layer material used for pressure bearing does not undergo hydrogen embrittlement and corrosion during use, the wellbore made of non-metallic material can have higher safety and reliability.

[0086] This invention enables the wellbore 20 to be designed as a single, integrally formed structure, thus eliminating the need for joints on the wellbore 20 itself and effectively improving the safety of the hydrogen storage well 200. The wellbore 20 of this invention is made of fiber-wound flexible composite material, effectively preventing leakage caused by corrosion of the wellbore 20. This invention also uses an airbag 211 instead of cement grout to restrict the position of the wellbore 20, and, combined with the second connecting pipe 41 and the third connecting pipe 51, enables real-time adjustment of the gas within the annulus 12, ensuring that the pressure within the annulus 12 remains within a controllable range, further improving the safety of the hydrogen storage well 200. Furthermore, compared to hydrogen storage wells made of metal, this invention is more suitable for underground environments and easier to implement high-pressure storage.

[0087] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art can easily make changes or modifications within the scope of the present invention, and such changes or modifications should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A hydrogen storage device (100), comprising: A wellbore (20) that can be inserted into the base well (10) of a hydrogen storage well (200) and used to contain hydrogen. An annular fixing seat (11) for setting the wellhead of the base well (10); and A first joint (22) is sealed to the upstream end of the wellbore (20), the first joint (22) including a support (221) for engaging with the annular fixing seat (11). The wellbore (20) is constructed as a continuous wellbore made of fiber-wound flexible composite material, which includes an inner impermeable layer, a reinforcing layer, and an outer protective layer arranged radially in sequence. The hydrogen storage device (100) further includes a second valve (40) disposed on the support base (221), and a second connecting pipe (41) passing through the second valve (40) and extending into the annulus (12) between the base well (10) and the wellbore (20). The hydrogen storage device (100) also includes a third valve (50) and a third connecting pipe (51) disposed on the support base (221). Inert gas is first injected through the third connecting pipe (51) to replace the oxygen in the annulus (12), and then the third valve (50) is opened to discharge the permeated hydrogen gas to the outside through the third connecting pipe (51). The hydrogen storage device (100) also includes several delivery mechanisms (21) sleeved outside the wellbore (20), a first valve (30) disposed on the support (221), and a first connecting pipe (31). The delivery mechanism (21) includes an airbag (211) and a centralizer (212). The first connecting pipe (31) extends through the first valve (30) and communicates with each airbag (211). The airbag (211) can expand radially outward and sit sealed inside the base well (10) after gas is supplied by the first connecting pipe (31). The hydrogen storage device (100) also includes a pressure sensor disposed inside the support (221). The pressure sensor can monitor the pressure of the annulus (12) inside the wellbore (20) in real time and discharge through the third connecting pipe (51) when the limit value is reached. The internal impermeable layer includes at least one of non-metallic and composite layers of metal and non-metal, and the wellbore (20) has an integrally formed structure and can be transported in a coiled manner.

2. The hydrogen storage device according to claim 1, characterized in that, The reinforcing layer comprises at least one of glass fiber, carbon fiber, metal wire and nylon fiber, and the outer protective layer comprises at least one of PE, PVDF and PA.

3. The hydrogen storage device according to claim 2, characterized in that, The centralizer (212) is provided with a plurality of rollers (213) for engaging with the inner wall of the base well (10).

4. The hydrogen storage device according to claim 3, characterized in that, A plurality of the delivery mechanisms (21) are arranged at equal intervals along the axial direction of the hydrogen storage device (100).

5. The hydrogen storage device according to claim 4, characterized in that, The hydrogen storage device (100) also includes a second connector (23) that is sealed to the downstream end of the wellbore (20), and a buffer (24) disposed downstream of the second connector (23), the buffer (24) being configured to abut against the bottom of the base well (10).

6. The hydrogen storage device according to any one of claims 1 to 5, characterized in that, The hydrogen storage device (100) further includes a first interface (60) and a second interface (61) disposed on the first connector (22) for guiding hydrogen, and a fourth connecting pipe (62), wherein the first end of the fourth connecting pipe (62) is fixedly connected to the second interface (61), and the second end extends to the bottom of the wellbore (20).

7. The hydrogen storage device according to any one of claims 1 to 5, characterized in that, The hydrogen storage device (100) also includes a safety valve (70) disposed on the first connector (22).

8. A hydrogen storage well (200), characterized in that, It includes a base well (10) and a hydrogen storage device (100) according to claim 6 disposed in the base well (10).

9. A method for regulating a hydrogen storage well according to claim 8, characterized in that, Includes the following steps: S1. The assembled hydrogen storage device (100) is placed into the base well (10); S2. The oxygen in the annulus (12) between the base well (10) and the wellbore (20) is replaced with an inert gas through the second connecting pipe (41) and the third connecting pipe (51); S3. Close the second interface (61) and fill the wellbore (20) with hydrogen through the first interface (60); S4. The pressure of hydrogen gas seeping from the wellbore (20) into the annulus (12) is monitored by a pressure sensor, and the third valve (50) is opened when the pressure reaches the limit of the pressure sensor, and the seeping hydrogen gas is discharged to the outside through the third connecting pipe (51).

10. The adjustment method according to claim 9, characterized in that, The cross-sectional area of ​​the wellbore (20) accounts for 60 to 90% of the cross-sectional area of ​​the base well (10).

Images