Large-size sealed door structure for high-pressure underground gas storage facilities

Abstract

This invention relates to the field of underground gas storage technology for compressed air energy storage power stations, specifically to a large-size sealed door structure for high-pressure underground gas storage. It includes a sealed door, a sealing ring fixing steel plate, a first sealing ring, and a second sealing ring. A maintenance passage is provided inside a reinforced concrete plug. The sealed door is connected to the reinforced concrete plug via a sealing door support hinge. The maintenance passage is connected to the gas storage through the sealed door. The sealing ring fixing steel plate is fixed between the sealed door and the reinforced concrete plug. Both the first and second sealing rings are interference-fitted between the sealing ring fixing steel plate and the sealed door, with the first sealing ring positioned outside the second sealing ring. The sealed door structure is simple, adaptable to complex operating conditions, and ensures durability and reliability. It employs conventional sealing methods to form two seals, creating a double-layered protective barrier, resulting in good sealing performance, simple maintenance, and low repair costs.

Description

Technical Field

[0001] This invention relates to the field of underground gas storage technology for compressed air energy storage power stations, and specifically to a large-size sealed door structure for high-pressure underground gas storage. Background Technology

[0002] Compressed air energy storage technology is one of the key supporting technologies for realizing the large-scale consumption of new energy sources and building new power systems. It is also an important way to promote the upgrading of the energy structure and ensure the sustainable development of the energy and power industry. Northwest my country is rich in photovoltaic and wind energy resources. By constructing large-scale compressed air energy storage power stations in conjunction with wind and solar power generation, the problems of peak shaving and valley filling and stable output can be solved at the sending-end power grid.

[0003] In the design of compressed air energy storage power station gas storage tanks, the sealing layer is a crucial component. Its responsibility is to protect the gas storage tank from gas leaks, thereby ensuring the safety and reliability of the system. This includes the sealing door structure. The main function of the sealing door is to facilitate maintenance personnel bringing small equipment into the gas storage tank during operation to quickly repair locally damaged linings. To withstand the high-pressure gas stored inside the gas storage tank, the sealing door is generally made of high-hardness steel. The effectiveness of the interface seal between the sealing door and the plug directly affects the normal functioning of the overall sealing layer. If any tiny gap exists at the interface, forming a leakage channel, high-pressure gas will leak along this channel. Therefore, the interface seal design of the sealing door is particularly important.

[0004] Currently, both domestically and internationally, the interface sealing between the sealing door and the plug of a high-pressure gas storage facility is classified into two categories based on its working principle: forced sealing and self-tightening sealing. Forced sealing relies on the pre-tightening force of the connecting parts to ensure the sealing effect. Self-tightening sealing, on the other hand, increases the clamping force between the sealing elements on the contact surface as the working pressure increases, resulting in better sealing performance and reliable sealing even under fluctuating operating conditions.

[0005] Chinese utility model patent CN206309244U discloses a gas storage sealing door structure and an underground cavern gas storage for energy storage power stations. The sealing door is designed to be self-tightening and sealed. By providing a groove on the door frame and setting two sets of serrated surfaces with sealing rubber sheets at the bottom and top of the groove, the contact area at the joint of the sealing door is increased, ensuring the airtightness of the sealing door.

[0006] Chinese invention patent CN113736243A discloses sealing materials, sealing rings, manufacturing methods, and underground gas storage facilities for use in the sealing door structure of underground gas storage facilities. The sealing door design employs a combination of forced sealing and self-tightening sealing. A seepage barrier is formed by using rigid baffles and sealing rings to prevent gas leakage. The sealing material is made by mixing polyurea, expanded clay, ceramsite powder, and additives in a specific mass ratio to ensure reliable high-pressure gas leakage prevention. Considering the needs of a specific project, the design internal pressure is close to 20 MPa throughout the entire operating cycle, with a gas storage pressure fluctuation range of 5–6 MPa, and more than 10,000 filling and venting cycles. For ease of maintenance, the maintenance door size is close to 1.5m. The high internal pressure, cyclic loads, multiple media, and numerous uncertainties within the gas storage facility will present many challenges to the design of large-size maintenance doors. To meet these conditions, the maintenance door design must satisfy economic efficiency, applicability, and durability. By incorporating grooves and serrated surfaces to increase the contact area, the maintenance door, under complex operating conditions, is prone to deformation, making it difficult to close effectively and creating a potential leakage hazard. Its durability is also questionable. Furthermore, the suitability of sealing materials made by mixing different materials in a specific mass ratio for such complex operating conditions remains unknown. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of existing technologies by providing a large-size sealing door structure for high-pressure underground gas storage facilities. This sealing door structure is simple in design, adaptable to complex operating conditions, and ensures durability and reliability. It employs conventional sealing methods to form two seals, creating a double-layered protective barrier. This results in excellent sealing performance, simple inspection and maintenance, and low repair costs.

[0008] This invention provides a large-size sealing door structure for a high-pressure underground gas storage facility, comprising a sealing door, a sealing ring fixing steel plate, a first sealing ring, and a second sealing ring. A reinforced concrete plug is provided outside the gas storage facility, and a maintenance passage is provided inside the reinforced concrete plug. The sealing door is connected to the reinforced concrete plug via a sealing door support hinge, and the maintenance passage is connected to the gas storage facility via the sealing door. The sealing ring fixing steel plate is fixed between the sealing door and the reinforced concrete plug. Both the first and second sealing rings are interference-fitted between the sealing ring fixing steel plate and the sealing door, with the first sealing ring positioned outside the second sealing ring.

[0009] Preferably, the sealing door includes a flat steel plate door, a circumferential support steel plate, a vertical support steel plate, and a horizontal support steel plate. The circumferential support steel plate is fixedly connected to the surface of the flat steel plate door facing the gas storage tank. The vertical support steel plate and the horizontal support steel plate are arranged perpendicularly to each other inside the circumferential support steel plate, and their ends are fixedly connected to the inner wall of the circumferential support steel plate, and their bottoms are fixedly connected to the surface of the flat steel plate door.

[0010] Preferably, the planar steel plate door, the circumferential support steel plate, the vertical support steel plate, and the horizontal support steel plate are combined and welded together to form a sealed door.

[0011] Preferably, the inner wall of the maintenance passage is fixedly provided with a maintenance passage lining steel plate.

[0012] Preferably, the sealing ring fixing steel plate is fixed to the inner lining steel plate of the maintenance passage and the end of the reinforced concrete plug.

[0013] More preferably, it also includes a bolt fixing steel plate and a bolt supporting steel plate. The bolt fixing steel plate is fixed to the surface of the sealing door facing the maintenance passage, and the bolt supporting steel plate is fixed to the inner lining steel plate of the maintenance passage. The bolt fixing steel plate and the bolt supporting steel plate are connected by fastening bolts.

[0014] Preferably, the second sealing ring is a triangular gasket sealing ring.

[0015] Preferably, the surface of the bolt fixing steel plate opposite to the sealing door is provided with an annular groove, and the triangular gasket sealing ring is interference-fitted in the annular groove, with the surface of the triangular gasket sealing ring protruding from the surface of the bolt fixing steel plate.

[0016] Preferably, the first sealing ring is a hollow metal O-ring sealing ring, and an annular corner groove is formed at the edge of the surface of the bolt fixing steel plate opposite to the sealing door. The hollow metal O-ring sealing ring is interference-fitted into the annular corner groove, and the surface of the hollow metal O-ring sealing ring protrudes from the surface of the bolt fixing steel plate.

[0017] Preferably, the second sealing ring is connected to a signal receiver via a data cable.

[0018] The beneficial effects of this invention are as follows:

[0019] 1. By arranging a first sealing ring on the outer side of the sealing interface, high-pressure air is prevented from entering the sealing interface during frequent inflation and deflation. Once high-pressure air enters the interface, harmful substances in the air will corrode the interface, and the high-pressure gas will cause pressure fracturing at the interface, significantly reducing the sealing effect of the internal sealing ring. A second sealing ring is arranged in the middle of the sealing interface, forming a double protective barrier. The sealing door structure is simple, can adapt to complex operating conditions, and ensures durability and reliability. Using conventional sealing methods to form two seals creates a double sealing protection barrier, resulting in good sealing performance, simple inspection and maintenance, and low maintenance costs.

[0020] 2. By installing fastening bolts on the inspection door, a certain contact pressure is ensured at the sealing interface between the sealing door and the plug, avoiding frequent inflation and deflation that could affect the durability of the sealing ring and thus the sealing effect. The design of the sealing door employs a combination of forced sealing and self-tightening sealing methods, effectively improving the sealing performance.

[0021] 3. The first sealing ring uses a hollow metal O-ring. Under normal operating conditions, the gas storage tank will be frequently filled and vented, causing the hollow metal O-ring to contract and expand to some extent. During filling, the pressure on the hollow metal O-ring increases, causing it to fit more tightly between the flat steel door and the sealing ring fixing plate. During venting, due to the tightening bolts, even if the pressure on the hollow metal O-ring decreases and it contracts, high-pressure air will not enter the contact surface between the flat steel door and the sealing ring fixing plate. As operating time increases, if the hollow metal O-ring fails, the second sealing ring formed by the triangular gasket will activate and bear all internal pressure, preventing leakage of high-pressure gas. Furthermore, due to the sudden increase in pressure on the triangular gasket, a pressure signal will be transmitted to the signal receiver, indicating that the hollow metal O-ring has failed, allowing the gas storage tank to be automatically shut down for maintenance. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention;

[0023] Figure 2 for Figure 1 Schematic diagram of section I-I;

[0024] Figure 3 for Figure 1 Schematic diagram of section II-II;

[0025] Figure 4 for Figure 2 Enlarged schematic diagram of part A;

[0026] Figure 5 for Figure 4 Enlarged schematic diagram of Part B;

[0027] Figure 6 for Figure 4 The second enlarged schematic diagram of part B.

[0028] Figure 7 Von Mises stress contour diagram of a sealed door under high internal pressure operating conditions (unit: Pa);

[0029] Figure 8 Von Mises stress contour diagram of the sealed door under low internal pressure operating conditions (unit: Pa);

[0030] Figure 9 Deformation contour map of the sealing door under high internal pressure operating conditions (unit: m);

[0031] Figure 10 Deformation contour map of the sealing door under low internal pressure operating conditions (unit: m);

[0032] In the diagram: 1. Flat steel plate door, 2. Circumferential support steel plate, 3. Vertical support steel plate, 4. Horizontal support steel plate, 5. Bolt fixing steel plate, 6. Fastening bolt, 7. Sealing door support hinge, 8. Bolt support steel plate, 9. Maintenance passage lining steel plate, 10. Reinforced concrete plug, 11. Maintenance passage, 12. Triangular gasket sealing ring, 13. Hollow metal O-ring sealing ring, 14. Gas storage tank, 15. Sealing ring fixing steel plate, 16. Data cable, 17. Signal receiver. Detailed Implementation

[0033] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0034] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0035] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0036] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0037] References to "one embodiment" or "some embodiments" in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized. "A plurality" means "two or more."

[0038] Example 1

[0039] Figures 1-3 A schematic diagram of a large-size sealing door structure for a high-pressure underground gas storage facility according to a preferred embodiment of this application is shown. For ease of explanation, only the parts relevant to this embodiment are shown, and are described in detail below:

[0040] The sealing door structure of this invention adopts a flat door support structure composed of a circumferential support steel plate 2, a vertical support steel plate 3, and a transverse support steel plate 4; it adopts a sealing door design concept that combines forced sealing and self-tightening sealing; it increases the contact pressure between the sealing door and the plug by arranging fastening bolts on the maintenance door; and it uses a combination of hollow metal O-ring seals 13 and triangular gasket seals 12 for sealing treatment. The hollow metal O-ring seals 13 are arranged on the outside of the sealing interface to form the first sealing ring, and the triangular gasket seals 12 are arranged in the middle of the sealing interface to form the second sealing ring, thereby forming a double protective barrier.

[0041] The maintenance passage 11 is connected to the gas storage tank 14 via a sealed door. The maintenance passage 11 is housed within a reinforced concrete plug 10, and a steel plate 9 is installed inside the maintenance passage 11. The sealed door includes a flat steel plate door 1, a circumferential support steel plate 2, a vertical support steel plate 3, and a horizontal support steel plate 4. The circumferential support steel plate 2 is fixedly connected to the surface of the flat steel plate door 1 facing the gas storage tank 14. The vertical support steel plate 3 and the horizontal support steel plate 4 are perpendicularly arranged within the circumferential support steel plate 2, with their ends fixed to the inner wall of the circumferential support steel plate 2 and their bottoms fixed to the surface of the flat steel plate door 1. To adapt to the high-pressure, frequent inflation and deflation environment in the gas storage tank 14, the sealed door is welded together from the flat steel plate door 1, the circumferential support steel plate 2, the vertical support steel plate 3, and the horizontal support steel plate 4. Figures 7-10As shown, calculations and analysis show that the maximum Von Mises stress of the sealed door under high internal pressure operation is 386 MPa, and the maximum deformation is 1.568 mm; under low internal pressure operation, the maximum Von Mises stress is 270 MPa, and the maximum deformation is 1.098 mm. The Von Mises stress variation is 116 MPa, and the deformation variation is 0.47 mm, which meets the specifications. The sealed door is connected to the reinforced concrete plug 10 via the sealed door support hinge 7, facilitating maintenance and opening / closing.

[0042] like Figures 4-6 As shown, the bolt-fixing steel plate 5 is welded to the flat steel plate door 1, and the bolt-supporting steel plate 8 is welded to the inner lining steel plate 9 of the maintenance passage. The fastening bolt 6 is used to connect the bolt-fixing steel plate 5 and the bolt-supporting steel plate 8. An annular groove is cut in the middle of the surface of the sealing ring fixing steel plate 15 to fix the triangular gasket sealing ring 12 within it. The thickness of the triangular gasket sealing ring 12 is slightly greater than the depth of the annular groove. An annular corner groove is cut on the outer side of the surface of the sealing ring fixing steel plate 15 to fix the hollow metal O-ring sealing ring 13 within it. The thickness of the hollow metal O-ring sealing ring 13 is slightly greater than the depth of the corner groove.

[0043] The working principle of this device is as follows:

[0044] After maintenance is completed, the maintenance door will be closed, and the flat steel plate door 1 and the sealing ring fixing steel plate 15 will be tightly fitted together by pre-tightening the fastening bolts. The triangular gasket sealing ring 12 and the hollow metal O-ring sealing ring 13 will be squeezed under the action of the flat steel plate door 1, so that the triangular gasket sealing ring 12 and the hollow metal O-ring sealing ring 13 will be tightly fitted between the flat steel plate door 1 and the sealing ring fixing steel plate 15.

[0045] Under normal operating conditions, the gas storage tank 14 will be frequently filled and vented, causing the hollow metal O-ring seal 13 to contract and expand to some extent. During filling, the pressure on the hollow metal O-ring seal 13 increases, causing it to fit more tightly between the flat steel door 1 and the sealing ring fixing steel plate 15. During venting, due to the action of the fastening bolts, even if the pressure on the hollow metal O-ring seal 13 decreases and it contracts, high-pressure air will not enter the contact surface between the flat steel door 1 and the sealing ring fixing steel plate 15.

[0046] As operating time increases, if the hollow metal O-ring seal 13 fails, the triangular gasket seal 12 will activate and bear all internal pressure to prevent leakage of high-pressure gas. Due to the sudden increase in pressure on the triangular gasket seal 12, a pressure signal will be transmitted to the signal receiver, indicating that the hollow metal O-ring seal 13 has failed and the gas storage tank 14 should be shut down for maintenance.

[0047] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A large-size sealing door structure for a high-pressure underground gas storage facility, characterized in that: The system includes a sealing door, a sealing ring fixing steel plate (15), a first sealing ring, and a second sealing ring. A reinforced concrete plug (10) is provided outside the gas storage tank (14). An inspection channel (11) is provided inside the reinforced concrete plug (10). The sealing door is connected to the reinforced concrete plug (10) through a sealing door support hinge (7). The inspection channel (11) is connected to the gas storage tank (14) through the sealing door. The sealing ring fixing steel plate (15) is fixed between the sealing door and the reinforced concrete plug (10). The first sealing ring and the second sealing ring are both interference-fitted between the sealing ring fixing steel plate (15) and the sealing door. The first sealing ring is located outside the second sealing ring. The inner wall of the maintenance passage (11) is fixedly provided with a maintenance passage lining steel plate (9). It also includes a bolt fixing steel plate (5) and a bolt support steel plate (8). The bolt fixing steel plate (5) is fixed on the side surface of the sealing door facing the maintenance passage (11), and the bolt support steel plate (8) is fixed on the inner lining steel plate (9) of the maintenance passage. The bolt fixing steel plate (5) and the bolt support steel plate (8) are connected by fastening bolts (6). The second sealing ring is a triangular gasket sealing ring (12); The bolt-fixing steel plate (5) has an annular groove on the surface opposite to the sealing door. The triangular gasket sealing ring (12) is interference-fitted into the annular groove, and the surface of the triangular gasket sealing ring (12) protrudes from the surface of the bolt-fixing steel plate (5). The first sealing ring is a hollow metal O-ring sealing ring (13). The bolt fixing steel plate (5) and the sealing door have an annular corner groove at the edge position. The hollow metal O-ring sealing ring (13) is interference-fitted in the annular corner groove. The surface of the hollow metal O-ring sealing ring (13) protrudes from the surface of the bolt fixing steel plate (5). Under normal operating conditions, the gas storage tank (14) will be filled and vented. During the filling process, the pressure on the hollow metal O-ring seal (13) increases, and the hollow metal O-ring seal (13) will fit more tightly between the flat steel plate door (1) and the sealing ring fixing steel plate (15). During the venting process, due to the action of the fastening bolts, even if the pressure on the hollow metal O-ring seal (13) decreases and it contracts, the high-pressure air will not enter the contact surface between the flat steel plate door (1) and the sealing ring fixing steel plate (15).

2. The large-size sealing door structure for high-pressure underground gas storage facilities according to claim 1, characterized in that: The sealing door includes a flat steel plate door (1), a circumferential support steel plate (2), a vertical support steel plate (3), and a horizontal support steel plate (4). The circumferential support steel plate (2) is fixedly connected to the surface of the flat steel plate door (1) facing the gas storage tank (14). The vertical support steel plate (3) and the horizontal support steel plate (4) are perpendicular to each other inside the circumferential support steel plate (2), and their ends are fixedly connected to the inner wall of the circumferential support steel plate (2), and their bottoms are fixedly connected to the surface of the flat steel plate door (1).

3. The large-size sealing door structure for high-pressure underground gas storage facilities according to claim 2, characterized in that: The flat steel plate door (1), circumferential support steel plate (2), vertical support steel plate (3) and horizontal support steel plate (4) are combined and welded together to form a sealed door.

4. The large-size sealing door structure for high-pressure underground gas storage facilities according to claim 3, characterized in that: The sealing ring fixing steel plate (15) is fixed to the inner lining steel plate (9) of the maintenance passage and the end of the reinforced concrete plug (10).

5. The large-size sealing door structure for high-pressure underground gas storage facilities according to claim 1, characterized in that: The second sealing ring is connected to a signal receiver (17) via a data cable (16).

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