Air cushion sealing device, salt cavern cavity forming pipe set, salt cavern cavity forming structure and cavity forming method

Abstract

The application discloses a kind of air cushion sealing device, salt cave cavity forming pipe group, salt cave cavity forming structure and cavity forming method, air cushion sealing device includes short section pipe, outer ring cover, annular seat, sliding cover, elastic element and rubber sleeve;Outer ring cover coaxially covers and is arranged outside short section pipe, annular seat coaxially covers and is arranged on short section pipe, and the outer wall of annular seat is connected with the inner lower end of outer ring cover;Sliding cover is arranged outside short section pipe, and the outer wall of sliding cover is in sliding sealing contact with the inner wall of outer ring cover, and short section pipe, annular seat, outer ring cover and sliding cover are collectively enclosed to form annular cavity;Annular seat is provided with pressure balance hole that is penetrated from top to bottom and is connected with annular cavity in;Elastic element is arranged in annular cavity, rubber sleeve is covered outside outer ring cover, and the outer wall of outer ring cover is sealingly connected at both ends of rubber sleeve to collectively enclose to form an expansion cavity, the middle part of outer ring cover inner wall is provided with vent hole that is connected with expansion cavity in, and air inlet valve is embedded in vent hole, its structure is simple, and its plugging effect to hole is good.

Description

Technical Field

[0001] This invention belongs to the field of salt cavern storage technology, and particularly relates to an air cushion sealing device, a salt cavern cavity-forming tube assembly, a salt cavern cavity-forming structure, and a cavity-forming method. Background Technology

[0002] Natural gas is a safe, efficient, and high-quality clean energy source, and its share in the energy mix is ​​increasing. Salt cavern gas storage technology is an advanced method of storing natural gas using underground salt layer space. By injecting water to dissolve the salt layer and create storage space, it allows for flexible regulation of natural gas supply, balancing seasonal or consumption fluctuations and meeting energy reserve needs. Simultaneously, salt cavern gas storage spaces can also be used for underground energy storage construction, improving energy efficiency, enhancing energy security, and promoting the development of clean energy.

[0003] During the salt cavern cavity construction process, the height of the cavity-building tubing needs to be adjusted multiple times to control the cavity shape. Currently, domestic salt cavern storage facilities mainly use diesel fuel as a roof protection measure to control the cavity shape. Although this method offers high safety and controllability, it results in significant diesel fuel loss and pollution of the surrounding environment. If diesel fuel leaks into salt chemical plants, it could lead to production shutdowns. Using nitrogen as a solvent overcomes the shortcomings of diesel fuel as a solvent, offering higher environmental friendliness, safety, and economic benefits. It is also convenient to operate and relatively easy to monitor the gas-liquid interface, which can accelerate storage facility construction to some extent. However, adjusting the tubing height requires venting an air cushion layer, resulting in a waste of time and gas resources. Summary of the Invention

[0004] In order to solve the above-mentioned technical problems, the purpose of this invention is to provide an air cushion sealing device with a simple structure that can be inflated and deflated.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: an air cushion sealing device, comprising a short section tube, an outer ring sleeve, an annular seat, a sliding sleeve, an elastic element, and a rubber sleeve;

[0006] The short tube is arranged vertically, and the outer ring is coaxially sleeved outside the short tube, with an annular gap between them;

[0007] The annular seat is coaxially sleeved on the short section tube and located at the lower inner end of the annular gap. The outer wall of the annular seat is connected to the lower inner end of the outer ring sleeve.

[0008] The sliding sleeve is disposed outside the short section tube and located within the annular gap. The outer wall of the sliding sleeve is in sliding sealing contact with the inner wall of the outer annular sleeve, and the short section tube, annular seat, outer annular sleeve and sliding sleeve together enclose and form an annular cavity.

[0009] The annular seat is provided with a pressure balance hole that runs vertically through the annular cavity and communicates with the inside of the annular cavity.

[0010] The elastic member is arranged in the ring cavity, and two ends of the elastic member are respectively in abutment with one end of the annular seat and the sliding sleeve which is close to the annular seat;

[0011] The rubber sleeve is sleeved outside the outer ring sleeve, and two ends of the rubber sleeve are sealingly connected with the outer wall of the outer ring sleeve to jointly form an expansion cavity, the middle part of the inner wall of the outer ring sleeve is provided with an air inlet valve embedded in an air vent hole which is in communication with the expansion cavity.

[0012] The elastic force of the elastic member is used to drive the sliding sleeve to move upward to be in communication with the air vent hole in the ring cavity, or the sliding sleeve is pressed downward to overcome the elastic force of the elastic member and move downward to be in communication with the area above the sliding sleeve.

[0013] The beneficial effects of the above technical solution are that the air cushion sealing device forms an expansion cavity by arranging a rubber sleeve on the outer ring sleeve, and the outer ring sleeve is further provided with an air vent hole in communication with the expansion cavity and an air inlet valve in the air vent hole, and the sliding sleeve can move up and down between the nipple pipe and the outer ring sleeve, and has three position states during the up and down movement. When the sliding sleeve moves upward to the air vent hole in communication with the ring cavity under the action of the elastic member, the air inlet valve is opened to perform exhaust operation, when the sliding sleeve moves downward to block the air vent hole, the expansion cavity is pressure maintained, and when the sliding sleeve moves downward to be below the air vent hole, the air inlet valve is opened to perform inflation treatment in the expansion cavity, so that the rubber sleeve expands outward to block and separate the inside of the pipeline.

[0014] In the above technical solution, the outer side wall of the outer ring sleeve is recessed with an annular groove, and two ends of the rubber sleeve are sealingly connected with two sides of the annular groove to block the annular groove.

[0015] The beneficial effects of the above technical solution are that when the pressure in the expansion cavity is released, the rubber sleeve can be accommodated in the annular groove, so that the overall structure is beautiful.

[0016] In the above technical solution, a sealing ring is embedded at the contact between the annular seat and the nipple pipe.

[0017] The beneficial effects of the above technical solution are that the reliability of the annular seat mounted on the nipple pipe can be improved.

[0018] In the above technical solution, the upper end of the annular seat has a coaxially upward protruding partition sleeve, the upper end of the partition sleeve is coaxially recessed with an annular groove, the elastic member is located in the annular groove, and the lower end of the sliding sleeve is inserted into the annular groove and abuts against the upper end of the elastic member.

[0019] The beneficial effect of the above technical solution is that the installation effect of the annular seat on the short section pipe is better by setting the partition sleeve.

[0020] The upper end of the pressure balance hole in the above technical solution is located outside the partition sleeve.

[0021] The beneficial effect of the above technical solution is that the pressure balance hole can always communicate with the annular cavity.

[0022] The outer lower end of the sliding sleeve in the above technical solution is provided with a stepped notch, and when the sliding sleeve moves downward under the action of an external force to the upper end of the notch abuts against the upper end of the partition sleeve, the air hole communicates with the area above the sliding sleeve.

[0023] The beneficial effect of the above technical solution is that the partition sleeve can limit the maximum stroke of the sliding sleeve, thereby protecting the elastic member.

[0024] The air inlet valve in the above technical solution is an electromagnetic valve or a one-way valve, and the elastic member is a spring.

[0025] The beneficial effect of the above technical solution is that when the air inlet valve is an electromagnetic valve, the inflation cavity can be inflated and deflated, and when the air inlet valve is a one-way valve, the inflation cavity can only be inflated.

[0026] The second purpose of the present application is to provide a salt cavern cavity forming pipe group for forming a salt cavern in stages.

[0027] In order to achieve the above purpose, another technical solution of the present application is as follows: a salt cavern cavity forming pipe group, comprising a production sleeve, a cavity forming outer pipe, a cavity forming inner pipe and an air cushion sealing device as described above arranged in sequence from outside to inside, and the short section pipe is welded on the cavity forming outer pipe and constitutes a section of the cavity forming outer pipe.

[0028] The beneficial effect of the above technical solution is that the structure is simple, and by setting the air cushion sealing device on the cavity forming outer pipe, when the cavity forming outer pipe is placed in the production sleeve, the rubber sleeve will tightly adhere to the inner wall of the production sleeve to block the annular gap after the inflation cavity is inflated.

[0029] The third purpose of the present application is to provide a salt cavern cavity forming structure for forming a salt cavern in stages.

[0030] In order to achieve the above purpose, another technical solution of the present application is as follows: a salt cavern cavity forming structure, comprising a salt cavern body and a salt cavern cavity forming pipe group as described above, the lower ends of the cavity forming inner pipe and the cavity forming outer pipe are both lowered below the liquid level in the salt cavern body, and the horizontal height of the lower end of the cavity forming inner pipe is lower than the horizontal height of the lower end of the cavity forming outer pipe.

[0031] The beneficial effects of the above technical solution are that the structure is simple, so that the salt cavern body can be staged to form a cavity, and after each cavity forming stage is completed, the cavity forming inner tube and the cavity forming outer tube are lifted to perform the next cavity forming process.

[0032] The fourth object of the present application is to provide a cavity forming method for staging the cavity forming of a salt cavern.

[0033] In order to achieve the above object, another technical solution of the present application is as follows: a cavity forming method of the cavity forming structure of a salt cavern as described above, comprising the following steps:

[0034] Step 1: replace the appropriate spring of the air cushion sealing device according to the designed air cushion pressure, detect the air tightness of the air cushion sealing device, assemble it on the cavity forming outer tube, and pre-charge the inflation cavity to preliminarily separate the annular space between the production casing and the cavity forming outer tube by the rubber sleeve;

[0035] Step 2: lower the cavity forming outer tube into the production casing until the depth of the air cushion sealing device reaches the preset depth, and then open the air inlet valve and introduce compressed gas into the annular space between the production casing and the cavity forming outer tube until the sliding sleeve moves downward to introduce air into the inflation cavity and the rubber sleeve continues to expand to improve the effect of the rubber sleeve in separating the annular space between the production casing and the cavity forming outer tube;

[0036] Step 3: lower the cavity forming inner tube into the cavity forming outer tube until the lower end of the cavity forming inner tube is located below the liquid level and reaches the preset depth to perform the staged cavity forming;

[0037] Step 4: after the completion of the staged cavity forming operation, lift the cavity forming inner tube, raise the cavity forming outer tube, or perform the pipe cutting operation to make the length of the cavity forming outer tube meet the design height of the next stage;

[0038] Step 5: re-lower the cavity forming inner tube to the design height to perform the next stage of cavity forming operation;

[0039] Step 6: repeat steps 2-5 until the cavity forming operation is completed.

[0040] The beneficial effects of the above technical solution are that the operation is simple, and at this time the salt cavern body can be staged to form a cavity, and the air cushion sealing device mainly separates the annular gap between the cavity forming outer tube and the production casing, but the height of the cavity forming outer tube needs to be adjusted in each cavity forming stage, and at the same time the air cushion sealing device needs to maintain the separation effect of the annular gap. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1Structure diagram of the air cushion sealing device according to the embodiment 1 and the embodiment 2 of the present application;

[0042] Figure 2 Structure diagram of the salt cave cavity forming pipe set according to the embodiment 3 of the present application;

[0043] Figure 3 Structure diagram of the salt cave cavity forming structure according to the embodiment 4 of the present application.

[0044] In the figure: 11 short section pipe; 12 outer ring sleeve; 121 air hole; 122 air inlet valve; 123 annular groove; 13 annular seat; 131 sealing ring; 132 partition sleeve; 1321 ring groove; 133 pressure balance hole; 14 sliding sleeve; 141 notch; 15 elastic member; 16 rubber sleeve;

[0045] 1 air cushion sealing device; 2 production sleeve; 3 cavity forming outer pipe; 4 cavity forming inner pipe;

[0046] 100 salt cave cavity forming pipe set; 200 salt cave body. DETAILED DESCRIPTION

[0047] The principles and features of the present application are described below in conjunction with the accompanying drawings, and the examples are only used to explain the present application and are not used to limit the scope of the present application. In the following paragraphs, the present application is described in more detail by way of example with reference to the accompanying drawings. The advantages and features of the present application will be more apparent from the following description and claims. It should be noted that the drawings are very simplified and use non-precise proportions, only to facilitate, clearly assist in explaining the purpose of the embodiments of the present application.

[0048] Embodiment 1

[0049] The embodiment provides an air cushion sealing device, which comprises a short section pipe 11, an outer ring sleeve 12, an annular seat 13, a sliding sleeve 14, an elastic member 15 and a rubber sleeve 16;

[0050] The short section pipe 11 is vertically arranged, and the outer ring sleeve 12 is coaxially sleeved outside the short section pipe 11, and there is an annular gap between the two;

[0051] The annular seat 13 is coaxially sleeved on the short section pipe 11 and located at the inner lower end of the annular gap, and the outer wall of the annular seat 13 is connected with the inner lower end of the outer ring sleeve 12;

[0052] The sliding sleeve 14 is arranged outside the short section pipe 11 and located in the annular gap, the outer wall of the sliding sleeve 14 is in sliding sealing contact with the inner wall of the outer ring sleeve 12, and the short section pipe 11, the annular seat 13, the outer ring sleeve 12 and the sliding sleeve 14 jointly form an annular cavity;

[0053] The annular seat 13 is provided with a pressure balance hole 133 penetrating from top to bottom and communicating with the annular cavity;

[0054] The elastic member 15 is arranged in the annular cavity, and two ends of the elastic member 15 are respectively abutted against one end of the annular seat 13 and the sliding sleeve 14 which is close to each other;

[0055] The rubber sleeve 16 is sleeved outside the outer ring sleeve 12, and two ends of the rubber sleeve 16 are sealingly connected to the outer wall of the outer ring sleeve 12 to jointly form an expansion cavity. The middle part of the inner wall of the outer ring sleeve 12 is provided with an air vent hole 121 which communicates with the expansion cavity, and the air vent hole 121 is embedded with an air inlet valve 122;

[0056] The elastic force of the elastic member 15 is used to drive the sliding sleeve 14 to move upward to the state that the air vent hole 121 communicates with the annular cavity, or the sliding sleeve 14 is pressed downward to overcome the elastic force of the elastic member 15 and move downward to the state that the air vent hole 121 communicates with the area above the sliding sleeve 14.

[0057] The operation principle of the air cushion sealing device provided by the embodiment is that the rubber sleeve is arranged on the outer ring sleeve to form the expansion cavity, the air vent hole which communicates with the expansion cavity is arranged on the outer ring sleeve, and the air inlet valve is arranged in the air vent hole. The sliding sleeve is movable up and down between the nipple pipe and the outer ring sleeve, and has three position states during the up and down movement. When the sliding sleeve moves upward to the state that the air vent hole communicates with the annular cavity under the action of the elastic member, the air inlet valve is opened to perform the exhaust operation. When the sliding sleeve moves downward to block the air vent hole, the pressure in the expansion cavity is maintained. When the sliding sleeve moves downward to be below the air vent hole, the air inlet valve is opened to perform the inflation treatment in the expansion cavity, so that the rubber sleeve expands outward to block and separate the inside of the pipeline.

[0058] The air cushion sealing device provided by the embodiment is suitable to be installed on a carrier (a pipe or a rod section) and extend the pipe into a hole (a deep well or a pipe), at this time, the inflation cavity can be pre-inflated (a rubber sleeve can be provided with an inflating door core similar to a basketball or a football, so that the inflation cavity can be preliminarily inflated through the inflating door core when the air inlet valve is closed), so that the rubber sleeve is preliminarily expanded, then the carrier of the air cushion sealing device is extended into the hole to a corresponding depth, and the inflation cavity is expanded to a degree that can preliminarily separate the hole from the rubber sleeve (but the rubber sleeve cannot be too tightly attached to the inner wall of the hole, otherwise the frictional resistance will be increased when the rubber sleeve is lowered into the hole, affecting the service life of the rubber sleeve), and for the hole, the hole is separated into two parts by the air cushion sealing device, at this time, the end of the hole close to the hole port can be pressurized, and as the pressure increases, the sliding sleeve is pressed to slide close to the annular seat until the air hole is exposed, and after the air hole is exposed, the inflation cavity can be inflated by opening the air inlet valve, so that the rubber sleeve is more closely attached to the inner wall of the hole (improving the separation effect of the rubber sleeve on the hole), at this time, the air inlet valve can be closed, and then the end of the hole close to the hole port can be normally depressurized, and the sliding sleeve slides upward to reset under the action of the elastic member, at this time, the air hole is in communication with the annular cavity (as long as the air inlet valve is not opened, the pressure in the inflation cavity is not convenient), and the annular cavity is in communication with the hole through the pressure balance hole, when the inflation cavity needs to be depressurized, the inflation cavity can be depressurized by only opening the air inlet valve, thereby removing the separation of the rubber sleeve from the hole.

[0059] The rubber sleeve in the embodiment has high wear resistance, and a steel wire mesh can be embedded in the rubber sleeve to form a steel wire-rubber composite material, and carbon black is added to the rubber to improve the wear resistance of the rubber (for the rubber material, it is similar to the rubber material used in tires).

[0060] The outer side wall of the outer ring sleeve 12 is concave to form an annular groove 123, and the two ends of the rubber sleeve 16 are respectively and sealingly connected to the two sides of the annular groove 123 to block the annular groove 123, so that the rubber sleeve can be accommodated in the annular groove when the inflation cavity is depressurized, thereby making the overall structure beautiful.

[0061] The groove width of the annular groove in the embodiment can be 10-20 cm, the two ends of the rubber sleeve in the embodiment can be connected to the outer ring sleeve by riveting, and after riveting, the two ends of the rubber sleeve are clamped on the outer ring sleeve, and sealing treatment can also be performed at the contact between the two ends of the rubber sleeve and the outer ring sleeve (the specific measures of the sealing treatment can be to inject a tire repair fluid into the inflation cavity to block the possible air leakage position).

[0062] The sealing ring 131 is embedded at the contact position between the annular seat 13 and the short section pipe 11, so as to improve the reliability of the annular seat on the short section pipe.

[0063] The upper end of the annular seat 13 is provided with a coaxial upward protruding partition sleeve 132, the upper end of the partition sleeve 132 is coaxially recessed with a ring groove 1321, the elastic member 15 is located in the ring groove 1321, and the lower end of the sliding sleeve 14 is inserted into the ring groove 1321 and abuts against the upper end of the elastic member 15. The partition sleeve is arranged, so that the installation effect of the annular seat on the short section pipe is better.

[0064] The upper end of the pressure balance hole 133 is located outside the partition sleeve 132, so that the pressure balance hole can always communicate with the annular cavity.

[0065] The outer lower end of the sliding sleeve 14 is provided with a stepped notch 141, when the sliding sleeve 14 moves downward under the action of external force to the upper end of the notch 141 abutting against the upper end of the partition sleeve 132, the air vent 121 communicates with the area above the sliding sleeve 14, so that the partition sleeve can limit the maximum stroke of the sliding sleeve, so as to protect the elastic member.

[0066] The inner side of the upper end of the outer ring sleeve can be slightly bent in the box, so as to limit the stroke of the sliding sleeve upwardly sliding.

[0067] The air inlet valve 122 is an electromagnetic valve, and the elastic member 15 is a spring. When the air inlet valve is an electromagnetic valve, the inflation cavity can be inflated and deflated.

[0068] Since the electromagnetic valve is used in the air inlet valve in the present application, the conductive wire of the electromagnetic valve can pass out through the upper end of the outer ring sleeve.

[0069] Embodiment 2

[0070] The same as embodiment 1, the difference is that the air inlet valve 122 in the present embodiment is a one-way valve, so that the inflation cavity can only be inflated and cannot be deflated.

[0071] Since the one-way valve is used in the air inlet valve in the present embodiment, the inflation cavity cannot be deflated after being inflated, so the entire air cushion sealing device can be regarded as a disposable product at this time. Since it cannot be depressurized, it will be stuck in the hole (unless it is pulled out by force, but this requires higher wear resistance of the rubber sleeve. Of course, even if the rubber sleeve is worn out and broken under the force, the entire air cushion sealing device can better exit the hole at this time, and then the rubber sleeve can be replaced).

[0072] In this embodiment, since the expansion chamber does not require external gas discharge, the sliding sleeve can also block the vent when it is in the reset state, and the vent will only be exposed during the downward sliding process.

[0073] Example 3

[0074] like Figure 2 As shown, this embodiment provides a salt cavern cavity creation tube assembly, including a production sleeve 2, a cavity creation outer tube 3, a cavity creation inner tube 4, and an air cushion sealing device 1 as described in Embodiment 1 or Embodiment 2, arranged sequentially from the outside to the inside. The short section tube 11 is welded to the cavity creation outer tube 3 and constitutes a section of the cavity creation outer tube 3.

[0075] The advantages of this embodiment are: its structure is simple. By setting an air cushion sealing device on the outer tube of the cavity, when the outer tube of the cavity is placed in the production sleeve, after the expansion chamber is inflated, the rubber sleeve will fit tightly against the inner wall of the production sleeve to isolate the annular gap.

[0076] Example 4

[0077] like Figure 3 As shown, this embodiment provides a salt cavern cavity structure, including a salt cavern body 200 and a salt cavern cavity tube assembly 100 as described in Embodiment 3. The lower ends of the inner cavity tube 4 and the outer cavity tube 3 are both lowered below the liquid surface in the salt cavern body 200, and the horizontal height of the lower end of the inner cavity tube 4 is lower than the horizontal height of the lower end of the outer cavity tube 3.

[0078] The advantages of this embodiment are: its structure is simple, which allows for staged cavity creation of the salt cave body, and after each cavity creation stage is completed, the inner cavity creation tube and the outer cavity creation tube are lifted up for the next cavity creation process.

[0079] Example 5

[0080] This embodiment provides a cavity creation method for the salt cavern cavity structure as described in Embodiment 4, including the following steps:

[0081] Step 1: Replace the spring of the air cushion sealing device 1 with a suitable spring according to the pre-designed air cushion pressure, test the air tightness of the air cushion sealing device 1, and assemble it on the cavity outer tube 3. At the same time, pre-inflate the expansion cavity so that the rubber sleeve 16 initially isolates the annulus between the production sleeve 2 and the cavity outer tube 3.

[0082] Step 2: Lower the cavity-outer pipe 3 into the production casing 2 until the depth of the air cushion sealing device 1 is lowered to a preset depth, and the cavity-outer pipe 3 needs to be lowered below the liquid level of the salt cavern body 200, then open the air inlet valve 122, and introduce compressed gas into the annulus between the production casing 2 and the cavity-outer pipe 3, until the sliding sleeve 14 moves downward to introduce air into the expansion cavity and continues to expand by the rubber sleeve 16, to improve the effect of the rubber sleeve 16 on isolating the annulus between the production casing 2 and the cavity-outer pipe 3;

[0083] Step 3: Lower the cavity-inner pipe 4 into the cavity-outer pipe 3 until the lower end of the cavity-inner pipe 4 is located below the liquid level and reaches a preset depth to perform a phased cavity-formation;

[0084] Step 4: After the completion of the phased cavity-formation operation, the cavity-inner pipe 4 is pulled out, the cavity-outer pipe 3 is raised or a pipe cutting operation is performed to make the length of the cavity-outer pipe 3 meet the design height of the next stage;

[0085] Step 5: Re-lower the cavity-inner pipe 4 to the design height to perform the next stage of cavity-formation operation;

[0086] Step 6: Repeat steps 2-5 until the cavity-formation operation is completed.

[0087] The advantage of the embodiment is that it is easy to operate, and the salt cavern body can be formed in stages at this time, and the air cushion sealing device mainly isolates the annular gap between the cavity-outer pipe and the production casing, but the height of the cavity-outer pipe needs to be adjusted in each cavity-formation stage, but at the same time, the air cushion sealing device also needs to maintain the isolation effect of the annular gap.

[0088] It should be noted that the above detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs.

[0089] It should be noted that the terms used herein are only for the purpose of describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and furthermore, it should be understood that when the terms "comprise" and / or "include" are used in the specification, they indicate the presence of a feature, step, operation, device, component, and / or combination thereof.

[0090] It has to be noted that the terms "first", "second", etc. as used in the description and the claims and the above figures of the present application are used to describe different objects, not to describe a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and embodiments of the application described herein are capable of operating in other sequences than the one described or other than suggested by the above text.

[0091] Also, the use of "adapted to", "configured to", "arranged to", "capable of" or "configured for" herein is meant to open up the possibility that the object in question is not only "adapted to", "configured to", "arranged to", "capable of" or "configured for" the particular function in question, but can also be "adapted to", "configured to", "arranged to", "capable of" or "configured for" some other function, even if the other function is not explicitly described or otherwise set forth in the present application.

[0092] Furthermore, the terms "comprise" and "comprising" and any variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of steps or elements does not necessarily comprise only those steps or elements but can include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

[0093] For the purposes of the description hereinafter, the terms "upper", "lower", "right", "left", "vertical", "horizontal", "top", "bottom", "lateral", "medial", "front", "back" and derivatives thereof (e.g., "horizontally", "downwardly", "vertical", etc.) can be used herein with reference to the use of the application in the particular orientation as shown in the drawings. However, it will be understood that the application can assume any orientation, unless otherwise specified.

[0094] For example, if the device in the drawing is turned over, the device described as "above" or "below" other devices or structures can then be oriented "below" or "above" such other devices or structures. Accordingly, the exemplary terms "above" and "below" can encompass both an orientation of above and below. The devices can be oriented in other ways (rotated 90 degrees or placed in other orientations) and the spatially relative terms used herein interpreted accordingly.

[0095] The above merely describes preferred embodiments of the present application, and is not intended to limit the present application in any form; any person skilled in the art can easily implement the present application according to the drawings and the above description; however, any person skilled in the art can make some changes, modifications and equivalent changes of the above disclosed technical contents without departing from the technical solution of the present application, and the equivalent embodiments of the present application are still within the protection scope of the present application.

Claims

1. An air cushion sealing device, characterized by comprising: The utility model relates to a kind of short section pipe (11), outer ring sleeve (12), annular seat (13), sliding sleeve (14), elastic element (15) and rubber sleeve (16) comprising. The short section pipe (11) is vertically arranged, the outer ring sleeve (12) is coaxially sleeved on the outside of the short section pipe (11), and there is an annular gap between the two. The annular seat (13) is coaxially sleeved on the short section pipe (11) and located at the inner lower end of the annular gap, and the outer wall of the annular seat (13) is connected with the inner lower end of the outer ring sleeve (12). The sliding sleeve (14) is arranged outside the short section pipe (11) and located in the annular gap, and the outer wall of the sliding sleeve (14) is in sliding sealing contact with the inner wall of the outer ring sleeve (12), and the short section pipe (11), annular seat (13), outer ring sleeve (12) and sliding sleeve (14) jointly enclose an annular cavity. The annular seat (13) is provided with a pressure balance hole (133) penetrating up and down and communicating with the annular cavity. The elastic element (15) is arranged in the annular cavity, and the two ends of the elastic element (15) are respectively abutted against one end of the annular seat (13) and the sliding sleeve (14) which are close to each other. The rubber sleeve (16) is sleeved outside the outer ring sleeve (12), and the two ends of the rubber sleeve (16) are sealingly connected with the outer wall of the outer ring sleeve (12) to jointly enclose an expansion cavity, and the middle part of the inner wall of the outer ring sleeve (12) is provided with an air vent hole (121) communicating with the expansion cavity, and the air vent hole (121) is embedded with an air inlet valve (122). The elastic force of the elastic element (15) is used to drive the sliding sleeve (14) to move upward to communicate the air vent hole (121) with the annular cavity, or when the sliding sleeve (14) is pressed downward, it overcomes the elastic force of the elastic element (15) and moves downward to communicate the air vent hole (121) with the area above the sliding sleeve (14).

2. An air cushion seal as claimed in claim 1, wherein The outer side wall of the outer ring sleeve (12) is recessed with an annular groove (123), and the two ends of the rubber sleeve (16) are sealingly connected with the two sides of the annular groove (123) to block the annular groove (123).

3. An air cushion seal as claimed in claim 1, wherein The annular seat (13) is embedded with a sealing ring (131) at the contact with the short section pipe (11).

4. An air cushion seal as claimed in claim 1, wherein The upper end of the annular seat (13) has a coaxially upward protruding partition sleeve (132) on the inner side, the upper end of the partition sleeve (132) is coaxially recessed with an annular groove (1321), the elastic element (15) is located in the annular groove (1321), and the lower end of the sliding sleeve (14) is inserted into the annular groove (1321) and abuts against the upper end of the elastic element (15).

5. An air cushion seal as claimed in claim 4, wherein The upper end of the pressure balance hole (133) is located outside the partition sleeve (132).

6. An air cushion seal as claimed in claim 4, wherein The outer lower end of the sliding sleeve (14) is provided with a stepped notch (141), and when the sliding sleeve (14) moves downward under the action of external force to abut against the upper end of the partition sleeve (132) at the upper end of the notch (141), the air vent hole (121) communicates with the area above the sliding sleeve (14).

7. An air cushion seal as claimed in claim 4, wherein The intake valve (122) is an electromagnetic valve or a one-way valve, and the elastic member (15) is a spring.

8. A salt cavern tunneling tube group characterized by, The air cushion sealing device (1) comprises, from outside to inside, a production casing (2), a cavity-forming outer pipe (3), a cavity-forming inner pipe (4), and a cavity-forming pipe group (100) as claimed in any one of claims 1-7, and the short section pipe (11) is welded to the cavity-forming outer pipe (3) and forms a section of the cavity-forming outer pipe (3).

9. A salt cavern structure, characterized in that The cavity-forming pipe group (100) as claimed in claim 8 comprises a salt cavern body (200), and the lower ends of the cavity-forming inner pipe (4) and the cavity-forming outer pipe (3) are both submerged below the liquid level in the salt cavern body (200), and the horizontal height of the lower end of the cavity-forming inner pipe (4) is lower than that of the lower end of the cavity-forming outer pipe (3).

10. A method of caverning a salt cavern structure as defined in claim 9, wherein, The method comprises the following steps: Step 1: replace the spring of the air cushion sealing device (1) according to the pre-designed air cushion pressure, detect the air tightness of the air cushion sealing device (1), assemble the air cushion sealing device (1) on the cavity-forming outer pipe (3), and pre-charge the expansion cavity to preliminarily separate the annulus between the production casing (2) and the cavity-forming outer pipe (3) by the rubber sleeve (16); Step 2: lower the cavity-forming outer pipe (3) into the production casing (2) until the depth of the air cushion sealing device (1) reaches the pre-set depth, and the cavity-forming outer pipe (3) needs to be lowered below the liquid level in the salt cavern body (200), then open the intake valve (122), and introduce compressed gas into the annulus between the production casing (2) and the cavity-forming outer pipe (3) until the sliding sleeve (14) moves downward to introduce air into the expansion cavity and the rubber sleeve (16) continues to expand to improve the effect of the rubber sleeve (16) in separating the annulus between the production casing (2) and the cavity-forming outer pipe (3); Step 3: lower the cavity-forming inner pipe (4) into the cavity-forming outer pipe (3) until the lower end of the cavity-forming inner pipe (4) is located below the liquid level and reaches the pre-set depth to perform a phased cavity formation; Step 4: after the completion of the phased cavity formation, pull out the cavity-forming inner pipe (4), raise the cavity-forming outer pipe (3), or perform pipe cutting to make the length of the cavity-forming outer pipe (3) meet the design height of the next stage; Step 5: lower the cavity-forming inner pipe (4) to the design height again to perform the next stage of cavity formation; Step 6: repeat steps 2-5 until the cavity formation is completed.

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