A sealing device for gaseous hydrogen storage well

Abstract

The present invention belongs to the field of hydrogen storage technology, and specifically relates to a sealing device for gaseous hydrogen storage wells. The sealing device, used to seal any two adjacent casings of a gaseous hydrogen storage well, comprises a plurality of sealing rings arranged axially in sequence. The sealing rings are made of a rubber material with hydrogen-absorbing expansion properties, and each sealing ring is configured to sequentially absorb hydrogen expansion to seal. This invention can reduce the risk of hydrogen leakage and achieve safe and efficient hydrogen storage.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrogen storage, and in particular relates to a sealing device for a gaseous hydrogen storage well. Background Art

[0002] As a highly efficient and clean new energy source, hydrogen is the best choice for achieving the strategic goals of achieving carbon peak and carbon neutrality. The production, storage, transportation, and use of hydrogen are four key links in promoting the development of the hydrogen energy industry, with storage being the crucial link connecting production and use.

[0003] High-pressure gaseous hydrogen storage wells use steel casing to store high-pressure gaseous hydrogen. The main storage body is located underground. It has the advantages of small footprint, large storage capacity, and high safety performance. It can effectively promote the safe and efficient storage of hydrogen.

[0004] Hydrogen molecules are small, and high sealing performance is required for storage containers. High-pressure gaseous hydrogen storage wells are connected by multiple wellbore casings, and the casings are mostly sealed with a single threaded connection, which is a risk point for hydrogen leakage.

[0005] Furthermore, hydrogen storage wells are located underground. Any hydrogen leak at the casing interface is difficult to repair and could potentially cause the well to be out of service, resulting in economic losses. Therefore, a special sealing structure is required for the casing interface of high-pressure gas hydrogen storage wells to reduce the risk of hydrogen leakage and achieve safe and efficient hydrogen storage. Summary of the Invention

[0006] In response to the technical problems described above, the present invention aims to propose a sealing device for a gaseous hydrogen storage well, which can reduce the risk of hydrogen leakage and achieve safe and efficient storage of hydrogen.

[0007] According to the present invention, a sealing device is provided for sealing any two adjacent casings of a gaseous hydrogen storage well, comprising a plurality of sealing rings arranged in sequence along the axial direction, wherein the sealing rings are made of a rubber material having the property of absorbing hydrogen and expanding, and each of the sealing rings is configured to absorb hydrogen in sequence and expand for sealing.

[0008] In a preferred embodiment provided by the present invention, a plurality of sealing rings are respectively provided on the upper side and the lower side of the joint between two adjacent sleeves.

[0009] In a preferred embodiment provided according to the present invention, the sealing device further comprises a spacer ring, and a plurality of the spacer rings and the sealing rings are alternately arranged along the axial direction.

[0010] In a preferred embodiment provided according to the present invention, the sealing device further comprises a sealing sleeve, and the sealing sleeve is arranged on the outside of the sealing ring and the spacer ring.

[0011] In a preferred embodiment provided according to the present invention, the sealing sleeve is mounted on two adjacent sleeves.

[0012] In a preferred embodiment provided according to the present invention, two adjacent sleeves are connected by a coupling, the sealing sleeve is mounted on the coupling, both axial ends of the sealing sleeve exceed the axial range of the coupling, and the plurality of sealing rings are respectively arranged on the upper and lower sides of the coupling and located between the sleeve and the sealing sleeve.

[0013] In a preferred embodiment provided according to the present invention, a sealing hoop is provided on the outer wall of the sealing sleeve.

[0014] In a preferred embodiment provided according to the present invention, the two sealing rings are respectively provided at two axial ends of the sealing sleeve, corresponding to the positions of the sealing ring.

[0015] In a specific embodiment, four sealing rings are provided on the inner side of the sealing ring, namely a first sealing ring, a second sealing ring, a third sealing ring and a fourth sealing ring which are coaxially arranged in sequence.

[0016] A spacer ring is provided between each of two adjacent sealing rings, and a spacer ring is provided at the top of the first sealing ring and the bottom of the fourth sealing ring respectively, and the adjacent sealing rings and the spacer rings are axially abutted against each other.

[0017] In a specific embodiment, both axial ends of the sealing ring are bent inward to form baffles that can axially abut against the spacer ring. This arrangement can prevent the sealing ring and the spacer ring from axially moving.

[0018] In a preferred embodiment, in the initial state, the first sealing ring is larger than the remaining sealing rings. After the sealing ring is installed, the first sealing ring is in a pressure-bearing state, a semi-operating state, while the remaining sealing rings are in a non-operating state. When hydrogen leaks from the threaded connection between the sleeve and the coupling and penetrates the hydrogen sealing tape, the first sealing ring comes into contact with the hydrogen, absorbs hydrogen, and expands. Under the fixed action of the spacer rings on both sides, the first sealing ring expands radially, increasing the radial pressure between the first sealing ring and the sealing ring, improving the sealing performance, and achieving a hydrogen seal. At this time, the first sealing ring is in an operating state.

[0019] As the first seal ring operates for an extended period of time, it permanently deforms, degrading its sealing performance and potentially leading to hydrogen seal failure. After the first seal ring fails, the second seal ring comes into contact with hydrogen, absorbs it, and expands radially, forming a new hydrogen seal that remains operational.

[0020] When the second sealing ring fails, the third sealing ring repeats the previous working process.

[0021] In a preferred embodiment provided according to the present invention, the sealing hoop includes four quarter hoops.

[0022] In a preferred embodiment provided according to the present invention, mounting ears are provided at the circumferential ends of the clamps, and the mounting ears of two adjacent clamps are connected by bolts.

[0023] Compared with the prior art, the advantages of this application are as follows.

[0024] The present invention employs multiple axially distributed sealing rings, each made of a rubber material that expands upon absorption of hydrogen. Under this configuration, during operation, the sealing ring closest to the joint between two adjacent casings absorbs hydrogen and expands first, achieving a seal. The remaining sealing rings are inactive. After a sealing ring reaches the end of its service life, hydrogen gas flows through it and reacts with the next sealing ring, causing it to absorb hydrogen and expand, achieving a seal. This configuration increases the service life of the seal, meeting the long-term use requirements of hydrogen storage wells and avoiding frequent repairs of the sealing device.

[0025] The sealing hoop of the present invention is composed of four quarter hoops, so that the sealing ring is evenly stressed in the circumferential direction and has a better sealing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be described below with reference to the accompanying drawings.

[0027] Figure 1 A schematic diagram showing an embodiment of a sealing device according to the present invention installed on a gaseous hydrogen storage well;

[0028] Figure 2 A schematic diagram showing the external structure of the sealing device according to the present invention is shown;

[0029] Figure 3 It shows a schematic structural diagram of a sealing ring and a spacer ring according to the present invention;

[0030] Figure 4 A schematic structural diagram of a sealing ring according to the present invention is shown.

[0031] In the picture:

[0032] 1. Casing;

[0033] 2. Coupling;

[0034] 3. Sealing sleeve;

[0035] 4. Sealing ring; 41. First sealing ring; 42. Second sealing ring; 43. Third sealing ring; 44. Fourth sealing ring;

[0036] 5. Spacer ring;

[0037] 6. Sealing hoop;

[0038] 7. Hoop;

[0039] 8. Install the ears;

[0040] 9. Bolts;

[0041] 100. Sealing device.

[0042] In this application, all drawings are schematic drawings, which are only used to illustrate the principles of the present invention and are not drawn to scale. DETAILED DESCRIPTION

[0043] The present invention will be described below with reference to the accompanying drawings.

[0044] It should be noted that, in this application, the direction of the hydrogen storage well close to the wellhead of the present invention is described as "up", "front" or similar terms, i.e. Figure 1 The upper side of the gas storage well; and the direction close to the bottom of the well is described as "down", "back" or similar terms, that is, Figure 1 the lower side.

[0045] Figure 1 FIG. 1 shows a structure in which the sealing device 100 according to the present invention is installed on a hydrogen storage well. Figure 1 As shown, the hydrogen storage well includes multiple casings 1, which are coaxially connected to each other through couplings 2 to form the entire hydrogen storage well. A sealing device 100 is installed at the joint between two adjacent casings 1 to strengthen the seal between the two adjacent casings 1 of the hydrogen storage well.

[0046] In a preferred embodiment, the main body of the hydrogen storage well is a steel casing 1 with a diameter of 350 mm. Adjacent casings 1 are connected by couplings 2. Furthermore, the casings 1 and couplings 2 are secured and initially sealed using a threaded connection. The sealing device 100 provided by the present invention is installed on the outside of the couplings 2 to further seal the joint between the couplings 2 and the casing 1.

[0047] The interfaces of adjacent casings 1 of the hydrogen storage well adopt a single sealing measure such as welding or threaded sealing. Since hydrogen molecules are small and have strong escape performance, the interfaces of casing 1 are risk points for micro-leakage of hydrogen under high-pressure storage conditions.

[0048] In a preferred embodiment, after the casing 1 is connected via the coupling 2, multiple layers of hydrogen sealing tape (not shown) are wrapped around the outside of the coupling 2 and the outside of the connection between the coupling 2 and the casing 1. After the hydrogen sealing tape is installed, the sealing device 100 of the present invention is then applied.

[0049] According to the present invention, the sealing device 100 includes a plurality of sealing rings 4 arranged in sequence along the axial direction. The sealing rings 4 are made of a rubber material having hydrogen absorption and expansion characteristics. Each sealing ring 4 is configured to absorb hydrogen in sequence and expand to seal.

[0050] By setting up multiple sealing rings 4 of the present invention, in the initial state, each sealing ring 4 is in a non-working state, that is, each sealing ring 4 is not subjected to radial compression and cannot play a sealing role, so the life of each sealing ring 4 will not be reduced. When the coupling 2, hydrogen sealing tape, etc. leak, the hydrogen in the hydrogen storage well begins to leak, and the hydrogen contacts the sealing ring 4 closest to the leaking position. The sealing ring 4 begins to absorb hydrogen and expand, thereby being in a working state and playing a sealing role, while the remaining sealing rings 4 remain in a non-working state. When the sealing ring 4 closest to the leaking position fails, hydrogen begins to leak to the next sealing ring 4, and the next sealing ring 4 begins to absorb hydrogen and expand, thereby being in a working state and playing a sealing role.

[0051] The multiple sealing rings 4 of the present invention are turned on in sequence according to the distance from the leakage point from near to far, thereby extending the service life of the entire sealing device 100 and avoiding frequent repairs of the sealing device 100.

[0052] In a specific embodiment, multiple sealing rings 4 are provided on the upper and lower sides of the joints between two adjacent sleeves 1. Figure 1 In the embodiment, a plurality of sealing rings 4 are provided on both the upper and lower sides of the coupling 2 .

[0053] In a specific embodiment, the sealing ring 4 is configured as an O-ring and is made of a rubber material that expands upon hydrogen absorption, such as any one of fluororubber, EPDM rubber, acrylonitrile-butadiene rubber, polyisoprene rubber, styrene-butadiene rubber, and the like.

[0054] According to the present invention, the sealing device 100 includes a sealing sleeve 3, which is sleeved on the outside of the sealing ring 4. After the sealing ring 4 absorbs hydrogen and expands, the sealing ring 4 can radially abut against the sealing sleeve 3, so that the sealing ring 4 can seal the annulus between the sealing sleeve 3 and the casing 1.

[0055] In a preferred embodiment, the sealing sleeve 3 is made of a heat-shrinkable high molecular polymer material with hydrogen-blocking properties. By heating the sealing sleeve 3 , the sealing sleeve 3 can be tightened to form a sealing effect.

[0056] In a preferred embodiment, the sealing device further comprises a spacer ring 5, and a plurality of spacer rings 5 ​​and sealing rings 4 are alternately arranged along the axial direction. Figure 3 As shown, a plurality of spacer rings 5 ​​and a plurality of sealing rings 4 are alternately and coaxially sleeved on the outside of the sleeve 1 in sequence, and both the spacer rings 5 ​​and the sealing rings 4 are arranged between the sealing sleeve 3 and the sleeve 1 .

[0057] According to the present invention, the spacer ring 5 is made of a polymer material with small deformation.

[0058] Specifically, the spacer ring 5 is made of plastic.

[0059] Furthermore, the spacer ring 5 is made of polytetrafluoroethylene material having hydrogen resistance.

[0060] Through this arrangement of the present invention, the spacer ring 5 can provide an axial abutting force to the sealing ring 4 during the process of hydrogen absorption and expansion, so that the sealing ring 4 can only expand radially, thereby enhancing the sealing effect of the sealing ring 4.

[0061] According to the present invention, combined Figures 1 to 3 As shown, in a specific embodiment, the sealing sleeve 3 is sleeved on two adjacent sleeves 1 .

[0062] Specifically, two adjacent casings 1 are connected by a coupling 2, and a sealing sleeve 3 is sleeved on the coupling 2. Both axial ends of the sealing sleeve 3 exceed the axial range of the coupling 2. In other words, the axial length of the sealing sleeve 3 is greater than the axial length of the coupling 2.

[0063] A plurality of sealing rings 4 and a plurality of spacer rings 5 ​​are respectively arranged on the upper and lower sides of the coupling 2 and located between the casing 1 and the sealing sleeve 3. In other words, a plurality of sealing rings 4 and a plurality of spacer rings 5 ​​are arranged between the casing 1 and the portion of the casing 1 that exceeds the axial length range of the coupling 2.

[0064] In a preferred embodiment, the sealing ring 4 or the spacer ring 5 is in axial contact with the coupling 2. That is, the sealing ring 4 and the spacer ring 5 are alternately arranged. When the sealing ring 4 is close to the coupling 2, the sealing ring 4 is in axial contact with the coupling 2; when the spacer ring 5 is close to the coupling 2, the spacer ring 5 is in axial contact with the coupling 2.

[0065] Sealing hoops 6 are installed on the outer wall of the sealing sleeve 3. Two sealing hoops 6 are located at the two axial ends of the sealing sleeve 3, corresponding to the positions of the sealing ring 4. In other words, the sealing hoops 6 are placed on the outside of the sealing sleeve 3 to generate radial pressure on the expanded sealing ring 4, thereby enhancing the sealing effect.

[0066] like Figure 4 As shown, the sealing hoop 6 includes four quarter hoops 7. The four hoops 7 are combined to form a ring-shaped sealing hoop 6. Under this arrangement, the sealing hoop 6 is evenly stressed, thereby evenly generating radial pressure on the sealing ring 4, and having a good sealing effect.

[0067] Furthermore, mounting ears 8 are provided at the circumferential ends of the clamp 7 , and the mounting ears 8 of two adjacent clamps 7 are connected by bolts 9 .

[0068] In a specific embodiment, the circumferential ends of the clamp 7 are bent outward to form a mounting ear 8. The mounting ears 8 of two adjacent clamps 7 are connected by bolts 9. By adjusting the tightness of the bolts 9, the sealing clamp can generate different radial pressures, compressing the sealing sleeve 3 and the sealing ring 4, further improving the sealing performance of the sealing device 100.

[0069] like Figure 3 As shown, Figure 3 The sealing device 100 is shown with a sealing ring 4 located at a sealing ring 6 below the coupling 2. In this embodiment, four sealing rings 4 are provided inside the sealing ring 6, namely a first sealing ring 41, a second sealing ring 42, a third sealing ring 43, and a fourth sealing ring 44, which are coaxially arranged in sequence.

[0070] A spacer ring 5 is provided between each adjacent sealing ring 4 , and a spacer ring 5 is provided at the top of the first sealing ring 41 and the bottom of the fourth sealing ring 44 , respectively. Adjacent sealing rings 4 and spacer rings 5 ​​are axially abutted against each other.

[0071] In a specific embodiment, both axial ends of the sealing ring 6 are bent inward to form baffles (not shown) that can axially abut against the spacer ring 5. This arrangement can prevent the sealing ring 4 and the spacer ring 5 from axially moving.

[0072] In a preferred embodiment, in the initial state, the size of the first sealing ring 41 is larger than that of the remaining sealing rings 4. After the sealing ring 6 is installed, the first sealing ring 41 is in a pressure-bearing state, a semi-operating state, while the remaining sealing rings 4 are in a non-operating state. When hydrogen leaks from the threaded connection between the casing 1 and the coupling 2 and penetrates the hydrogen sealing tape, the first sealing ring 41 comes into contact with the hydrogen and absorbs hydrogen and expands. Under the fixed action of the spacer rings 5 ​​on both sides, the first sealing ring 41 expands radially, increasing the radial pressure between it and the sealing ring 6, improving the sealing performance, and achieving a hydrogen seal. At this time, the first sealing ring 41 is in an operating state.

[0073] As the first sealing ring 41 operates for an extended period of time, it permanently deforms, degrading its sealing performance and potentially leading to hydrogen seal failure. After the first sealing ring 41 fails, the second sealing ring 42 comes into contact with hydrogen, absorbs it, and expands radially, forming a new hydrogen seal that remains operational.

[0074] When the second sealing ring 42 fails, the third sealing ring 43 repeats the previous working process.

[0075] According to the above working process, the sealing ring 4 that is not exposed to hydrogen is not under pressure and is in a non-working state, and will not undergo permanent deformation. After contacting hydrogen, the sealing ring 4 will absorb hydrogen and expand, and after being under pressure, it will form a hydrogen seal and enter a working state.

[0076] Therefore, the sealing device 100 provided by the present invention does not require manual regular replacement due to failure of the sealing ring 4 under pressure. When the first sealing ring 41 fails, the second sealing ring 42 automatically takes effect, which is equivalent to automatic replacement of the sealing ring 4. Compared with manual replacement of the sealing ring 4, it can save a lot of time and can meet the long-term use requirements of the hydrogen storage well.

[0077] By providing multiple sealing rings 4 and spacer rings 5, the service life of the sealing structure can be greatly improved, effectively solving the problem that the underground structure of the hydrogen storage well cannot be replaced and repaired, effectively reducing the possibility of hydrogen leakage in the hydrogen storage well, and greatly improving the operational safety of the hydrogen storage well.

[0078] It is easy to understand that although four sealing rings 4 are provided in this embodiment, the present invention is not limited to four sealing rings 4. Those skilled in the art can also increase the number of sealing rings 4 based on the present invention and in combination with actual needs.

[0079] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0080] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0081] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0082] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and does not constitute any limitation to the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A sealing device for sealing any two adjacent casings (1) of a hydrogen storage well, characterized in that: include: A plurality of sealing rings (4) are sequentially arranged along the axial direction, wherein the sealing rings (4) are made of a rubber material having hydrogen absorption and expansion characteristics, and each of the sealing rings (4) is configured to absorb hydrogen in sequence and expand to seal, and a plurality of the sealing rings (4) are respectively arranged on the upper side and the lower side of the joint between two adjacent sleeves (1); Spacer rings (5), wherein a plurality of the spacer rings (5) and the sealing rings (4) are alternately arranged along the axial direction; A sealing sleeve (3), the sealing sleeve (3) is sleeved on the outside of the sealing ring (4) and the spacer ring (5), and the sealing sleeve (3) is sleeved on two adjacent sleeves (1); A coupling (2), wherein two adjacent sleeves (1) are connected via the coupling (2), the sealing sleeve (3) is sleeved on the coupling (2), both axial ends of the sealing sleeve (3) exceed the axial range of the coupling (2), and a plurality of sealing rings (4) are respectively arranged on the upper and lower sides of the coupling (2) and located between the sleeve (1) and the sealing sleeve (3).

2. The sealing device according to claim 1, characterized in that A sealing hoop (6) is provided on the outer wall of the sealing sleeve (3).

3. The sealing device according to claim 2, characterized in that The two sealing hoops (6) are respectively arranged at the two axial ends of the sealing sleeve (3), corresponding to the positions of the sealing ring (4).

4. The sealing device according to claim 2 or 3, characterized in that: The sealing hoop (6) comprises four quarter hoops (7).

5. The sealing device according to claim 4, characterized in that Mounting ears (8) are provided at the circumferential ends of the clamps (7), and the mounting ears (8) of two adjacent clamps (7) are connected by bolts.

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