High-precision regulation and control sealing cage sleeve type regulating valve and using method thereof

Abstract

The high-precision regulation and control sealing cage sleeve type regulating valve comprises a valve body, a transmission assembly and a driving device, the transmission assembly is connected between the valve body and the driving device, and the driving device controls opening and closing actions of the valve body through the transmission assembly; the transmission assembly comprises a transmission seat structure, a transmission rod and a transmission sleeve; a rotating sleeve of the transmission sleeve is arranged in the transmission seat structure, a lubricating cavity is formed between the transmission sleeve and the transmission seat structure, a thrust bearing is arranged in the lubricating cavity, and the transmission sleeve is fixedly connected with a driving device so as to rotate along with the driving device; a transmission rod penetrates through an inner cavity of the transmission sleeve inwards from the first end, the transmission sleeve and the transmission rod are connected through a spiral structure, and the spiral structure converts rotation of the transmission sleeve into movement of the transmission rod. By arranging the lubricating cavity and the thrust bearing on the transmission assembly, the friction resistance at the transmission assembly is reduced, so that the transmission assembly is large in torque and high in transmission efficiency, the control difficulty of the driving device is reduced, and the control precision of the valve element assembly is improved.

Description

Technical Field

[0001] The invention relates to the technical field of gas wellhead throttling regulating valves, and in particular to a high-precision controlled sealed cage-type regulating valve and a use method thereof. Background Art

[0002] With the development of society, the consumption of natural gas energy is also increasing. Shale gas is an unconventional natural gas stored in organic-rich shale, and the recoverable reserves of shale gas are large. Therefore, the development of shale gas collection technology is of great significance.

[0003] In the process of shale gas extraction, it is generally necessary to first drill from the ground to the underground shale gas storage area. After the drilling is completed, it is necessary to open perforations with a depth of 1m-2m in the radial direction of the borehole in the shale gas storage area. After that, it is necessary to inject mud with fine sand into the drilled gas well. The mud enters the perforations through the boreholes, and then under the action of pressure, a tree-like flow channel is formed with the perforations as the center. When the fine sand enters these flow channels with the mud, gaps can be formed in the gaps of the fine sand for water and natural gas to pass through. The fine sand can ensure that the flow channel will not close. Shale gas will enter the flow channel under the action of formation pressure, and allow shale gas to continuously pass through the flow channel from the gaps in the fine sand into the perforations, and then be sent out from the wellhead on the ground through the borehole.

[0004] After the above-mentioned shale gas collection channel system is built, shale gas can be delivered from the wellhead on the ground. If the pressure at the wellhead is not controlled, the pressure in the well will drop too quickly. Under the action of formation pressure, the fine sand used for support in the flow channel will be discharged along with the shale gas and water flow, causing the flow channel to close, which in turn causes the problem of reduced shale gas production and shortened production life. Especially in the early stage of shale gas production, the pressure in the gas well is relatively high and there is a large amount of water. When the pressure drop rate is relatively fast, the water flow will bring out the fine sand in the flow channel near the perforation and form a phenomenon of spitting out sand. The spitted out fine sand will not only cause the flow channel to close, but also erode the valve at the wellhead, making it more difficult to finely control the pressure in the gas well.

[0005] In order to ensure the smooth exploitation of shale gas, a pressure regulating valve needs to be installed at the wellhead of the gas well to control the daily pressure drop of the wellhead pressure within a certain range. In the existing shale gas process, the exploitation pressure drops quickly, and the adjustment accuracy of the wellhead throttle valve is poor, and the gas pressure cannot be finely controlled, resulting in the problem of reduced shale gas production and exploitation life. Therefore, how to accurately control the opening of the wellhead pressure of shale gas wells has become an issue that needs to be urgently solved in the shale gas exploitation process.

[0006] Therefore, the inventor, relying on many years of experience and practice in related industries, proposes a high-precision controlled sealed cage-type regulating valve and a method of using the same to overcome the defects of the prior art. Summary of the invention

[0007] The purpose of the present invention is to provide a sealed cage-type regulating valve with high-precision control and a method of using the same, so as to solve the problem that the existing valve core assembly has poor adjustment accuracy and cannot achieve refined production during the control process. The present invention arranges a lubrication cavity and a thrust bearing in the transmission assembly to reduce the friction resistance at the transmission assembly, so that the transmission assembly has a large torque and high transmission efficiency, reduces the control difficulty of the drive device, and improves the control precision of the valve core assembly.

[0008] The object of the present invention is achieved in this way. A sealed cage-type regulating valve with high-precision control comprises a valve body, a transmission assembly and a driving device, wherein the transmission assembly is connected between the valve body and the driving device, and the driving device controls the opening and closing action of the valve body through the transmission assembly; the transmission assembly comprises a transmission seat structure, a transmission rod and a transmission sleeve; the first end of the transmission sleeve is rotatably sleeved in the transmission seat structure, a lubrication cavity capable of accommodating lubricating grease is provided between the transmission sleeve and the transmission seat structure, a thrust bearing rotatably connecting the transmission sleeve and the transmission seat structure is provided in the lubrication cavity, and the second end of the transmission sleeve is fixedly connected to the driving device to rotate with it; the inner cavity of the transmission sleeve is penetrated from the first end to the inside by the transmission rod which is circumferentially fixed and axially movable, the inner wall of the transmission sleeve and the outer wall of the transmission rod are connected by a spiral structure, and the spiral structure converts the rotation of the transmission sleeve into the movement of the transmission rod; the valve body comprises a valve core assembly, and the second end of the transmission rod is connected to the valve core assembly to drive it to move and control the opening of the valve body.

[0009] In a preferred embodiment of the present invention, an axial gap space is set between the end face of the first end of the transmission sleeve and the bottom end face of the lubrication cavity, and the lubricating grease in the lubrication cavity can flow to the spiral structure between the transmission rod and the transmission sleeve through the axial gap space.

[0010] In a preferred embodiment of the present invention, the spiral structure includes an external fine pitch trapezoidal thread portion arranged on the outer wall of the transmission rod and an internal fine pitch trapezoidal thread portion arranged on the inner wall of the transmission sleeve, and the external fine pitch trapezoidal thread portion is spirally connected to the internal fine pitch trapezoidal thread portion.

[0011] In a preferred embodiment of the present invention, the transmission seat structure includes an upper transmission seat and a lower transmission seat that can be detachably connected, the first end of the transmission sleeve is rotatably sleeved in the upper transmission seat, the lubrication cavity is arranged between the transmission sleeve and the upper transmission seat, and the transmission rod seals and slides through the bottom end of the upper transmission seat; the top end of the lower transmission seat is connected to the outer wall of the upper transmission seat, the bottom end of the lower transmission seat is arranged to be open, the cross-sectional size of the opening is larger than the cross-sectional size of the transmission rod, and the valve core assembly passes through the bottom end of the lower transmission seat and is connected to the second end of the transmission rod.

[0012] In a preferred embodiment of the present invention, an upper step hole portion and a lower step hole portion that are connected are arranged from top to bottom in the upper transmission seat, a convex ring is arranged on the outer wall of the transmission sleeve, the aperture size of the upper step hole portion is larger than the outer diameter size of the convex ring, and the two ends of the convex ring are respectively against the thrust bearing, the lubrication cavity is located in the upper step hole portion, and a grease injection nozzle that connects the lubrication cavity and the external environment is pierced on the side wall of the upper transmission seat; the aperture size of the lower step hole portion is larger than the aperture size of the inner cavity of the transmission sleeve and smaller than the outer diameter size of the transmission sleeve; the first end of the transmission rod passes through the lower step hole portion and then penetrates into the inner cavity of the transmission sleeve, and a sealing arrangement is formed between the outer wall of the transmission rod and the inner wall of the lower step hole portion.

[0013] In a preferred embodiment of the present invention, an inspection cavity is provided in the lower transmission seat, and the second end of the transmission rod is connected to the valve core assembly via a connector, and the connector is located in the inspection cavity.

[0014] In a preferred embodiment of the present invention, a window hole is arranged on the side wall of the lower transmission seat, and an indicator plate arranged radially is connected to the transmission rod. The indicator plate can pass through the window hole and can move with the transmission rod to indicate the opening and closing state of the valve body.

[0015] In a preferred embodiment of the present invention, the valve body includes a valve body shell, a valve seat assembly, an end sealing assembly and the valve core assembly, an air inlet is arranged at the bottom end of the valve body shell, an operating port is arranged at the top end of the valve body shell, a buffer cavity is arranged between the air inlet and the operating port, an air outlet which can be connected with the buffer cavity is arranged on the side wall of the valve body shell, the valve seat assembly is fixedly arranged at the air inlet, a throttling hole which is connected with the air inlet is arranged on the side wall of the valve seat assembly at the buffer cavity, the top end of the valve seat assembly is slidably connected with the valve core assembly, and the valve core assembly can slidably open and close to control the flow area of ​​the throttling hole; the end sealing assembly is connected to the operating port, and the valve core assembly is sealingly passed through the end sealing assembly and connected with the transmission rod.

[0016] In a preferred embodiment of the present invention, the valve core assembly includes a sealing ring sleeve, a movable valve core sleeve and an operating rod; the first end of the operating rod seals and slides through the end sealing assembly and then extends into the lower transmission seat, and the first end of the operating rod is fixedly connected to the second end of the transmission rod; the second end of the operating rod is connected to the first end of the movable valve core sleeve, and the second end of the movable valve core sleeve is provided with a core sleeve groove inwardly, and the core sleeve groove is slidably sleeved on the valve seat assembly, and the inner side wall of the core sleeve groove is sleeved with the sealing ring sleeve; the transmission rod drives the operating rod, the movable valve core sleeve and the sealing ring sleeve to move to adjust the opening of the throttle hole.

[0017] In a preferred embodiment of the present invention, the end sealing assembly includes an end cover, a sliding sleeve, an operating sleeve seat and a composite sealing structure, the end cover is buckled on the top end of the valve body shell, the first end of the operating sleeve seat is sealingly inserted in the operating port, and the operating sleeve seat seals through the end cover, and a sliding sleeve is provided at the second end of the operating sleeve seat; the valve core assembly seals and slides through the operating sleeve seat and the sliding sleeve, and the composite sealing structure is provided between the valve core assembly and the operating sleeve seat.

[0018] In a preferred embodiment of the present invention, the composite sealing structure includes an upper composite seal and a lower composite seal, the operating rod is slidably inserted through the operating sleeve and the slide sleeve, and the upper composite seal is arranged between the operating rod and the operating sleeve; the movable valve core sleeve is sealingly slidably inserted in the operating sleeve, and the lower composite seal is arranged between the movable valve core sleeve and the operating sleeve.

[0019] In a preferred embodiment of the present invention, the upper composite seal includes a first annular skeleton mounted on the operating rod, the cross-section of the first annular skeleton is V-shaped, the V-shaped opening of the first annular skeleton is downwardly disposed, a first sealing filler unit is disposed at the top end of the first annular skeleton, and the slide sleeve axially presses against the first sealing filler unit.

[0020] In a preferred embodiment of the present invention, the lower composite seal comprises two second annular skeletons sleeved on the movable valve core sleeve, and a second sealing packing unit is arranged between the two second annular skeletons.

[0021] In a preferred embodiment of the present invention, a first sleeve inner hole is arranged inwardly at the first end of the operating sleeve, a second sleeve inner hole is arranged inwardly at the second end of the operating sleeve, and the first sleeve inner hole and the second sleeve inner hole are connected through a connecting hole; the lower composite seal is located in the first sleeve inner hole, the upper composite seal is located in the second sleeve inner hole, the movable valve core sleeve is sealingly slidably penetrated in the first sleeve inner hole, and a balancing chamber is formed between the upper composite seal and the top end of the movable valve core sleeve; a balancing hole is arranged through the movable valve core sleeve, and the balancing hole can connect the air inlet and the balancing chamber.

[0022] In a preferred embodiment of the present invention, the valve seat assembly includes a valve seat body and an air intake sleeve structure, the valve seat body is fixedly arranged at the air inlet, a valve seat center hole is axially arranged in the valve seat body, the air intake sleeve structure is fixedly sleeved in the valve seat center hole, an air vent is arranged in the air intake sleeve structure, the top end of the air intake sleeve structure extends out of the valve seat body, and the throttling hole connected to the buffer chamber is arranged on the side wall of the top end of the air intake sleeve structure, the core sleeve groove is slidably sleeved on the top end of the air intake sleeve structure, and the air vent can connect the air inlet, the balancing hole and the balancing chamber.

[0023] In a preferred embodiment of the present invention, a cushion block is arranged between the top end of the air inlet sleeve structure and the top wall of the core sleeve groove, and a balancing connecting hole is arranged on the cushion block, and the balancing connecting hole connects the balancing hole and the vent hole.

[0024] In a preferred embodiment of the present invention, an outer conical section with a diameter gradually decreasing from top to bottom is provided on the outer wall of the valve seat body, an inner conical surface with an aperture gradually decreasing from top to bottom is provided in the air inlet, and a metal sealing ring is provided between the outer conical section and the inner conical surface.

[0025] The object of the present invention can also be achieved by providing a method for using a high-precision controlled sealed cage-type regulating valve, comprising the following steps;

[0026] S1: Connect the air inlet of the sealed cage type regulating valve to the wellhead of the gas well;

[0027] S2: When the sealed cage-type regulating valve is in the closed state, the valve core assembly seals the throttle hole of the valve seat assembly, and the air inlet and the air outlet are disconnected;

[0028] S3: When the sealed cage type regulating valve is opened, the driving device is started, and the valve core assembly is driven upward through the transmission assembly to open the throttle hole, and the air inlet is connected with the air outlet.

[0029] As described above, the high-precision controlled sealed cage-type regulating valve and the use method thereof of the present invention have the following beneficial effects:

[0031] The present invention solves the problem that the existing regulating valve has poor regulating accuracy and cannot realize refined production during the control process by reducing the friction resistance during the transmission process; the transmission component has many relatively sliding parts, and the present invention increases the lubricity by arranging a lubrication cavity in the transmission component; and reduces the friction between the transmission sleeve and the transmission seat by arranging a thrust bearing; the present invention reduces the friction resistance at the transmission component, so that the transmission component has a large torque and high transmission efficiency, reduces the control difficulty of the drive device, and improves the control precision of the valve core component; the present invention can accurately control the pressure drop at the wellhead of the gas well to between 0.01Mpa-0.1Mpa / d, and reduce the probability of sand spitting or shale gas flow channel closure near the perforation during shale gas production. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The following drawings are only intended to illustrate and explain the present invention, and are not intended to limit the scope of the present invention.

[0033] in:

[0034] Figure 1 It is a schematic diagram of the overall structure of the high-precision controlled sealed cage-type regulating valve of the present invention.

[0035] Figure 2 The half-section structure schematic of the high-precision control sealed cage-type regulating valve of the present invention.

[0036] Figure 3 It is a schematic structural diagram of the transmission assembly of the present invention.

[0037] Figure 4 It is a structural schematic diagram of the valve body of the present invention.

[0038] Figure 5 for Figure 2 Enlarged view of point I in the middle.

[0039] Figure 6 for Figure 2 Enlarged view of point II in the middle.

[0040] In the figure:

[0041] 1. Valve body shell; 101. Air inlet; 102. Buffer chamber; 103. Air outlet; 104. Air inlet flange; 105. Operation port; 106. Pipe plug; 107. Air outlet flange;

[0042] 2. Valve seat assembly; 201. Valve seat body; 202. Lower sleeve; 203. Metal sealing ring; 204. Upper sleeve; 205. Throttle hole;

[0043] 3. Valve core assembly; 301. Sealing ring sleeve; 302. Movable valve core sleeve; 303. Balance hole; 304. Operating rod; 305. Cushion block;

[0044] 4. End sealing assembly; 401. End cover; 402. Lower composite seal; 403. Upper composite seal; 404. Slide sleeve; 405. Set screw; 406. Operating sleeve seat;

[0045] 5. Transmission assembly; 501. Lower transmission seat; 502. Indicator plate; 503. Window hole; 504. Transmission rod; 505. Inspection cavity; 506. Transmission sleeve; 507. Convex ring; 508. Upper transmission seat; 509. Lubrication cavity; 510. Thrust bearing; 511. Grease nipple; 512. Connector; 513. Axial clearance space;

[0046] 6. Driving device. DETAILED DESCRIPTION

[0047] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described with reference to the accompanying drawings.

[0048] The specific embodiments of the present invention described herein are only used to explain the purpose of the present invention and cannot be understood as limiting the present invention in any way. Under the guidance of the present invention, technicians can conceive of any possible variations based on the present invention, which should be considered to belong to the scope of the present invention. It should be noted that when an element is referred to as "arranged on" another element, it can be directly on the other element or there can also be a central element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be a central element at the same time. The terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, or it can be the internal communication of two elements, it can be directly connected, or it can be indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are only for illustrative purposes and do not represent the only implementation method.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0050] like Figures 1 to 6As shown, the present invention provides a high-precision controlled sealed cage-type regulating valve, comprising a valve body, a transmission assembly 5 and a drive device 6, wherein the transmission assembly 5 is connected between the valve body and the drive device 6, and the drive device 6 controls the opening and closing action of the valve body through the transmission assembly 5;

[0051] The transmission assembly 5 includes a transmission seat structure, a transmission rod 504 and a transmission sleeve 506; the first end of the transmission sleeve 506 is rotatably sleeved in the transmission seat structure, and a lubrication cavity 509 capable of accommodating lubricating grease is provided between the transmission sleeve 506 and the transmission seat structure, and a thrust bearing 510 rotatably connected to the transmission sleeve 506 and the transmission seat structure is provided in the lubrication cavity 509, and the second end of the transmission sleeve 506 is fixedly connected to the driving device 6 to rotate therewith; a circumferentially fixed and axially movable transmission rod 504 is penetrated from the first end to the inside of the inner cavity of the transmission sleeve 506, and the inner wall of the transmission sleeve 506 and the outer wall of the transmission rod 504 are connected by a spiral structure, and the spiral structure converts the rotation of the transmission sleeve 506 into the movement of the transmission rod 504; the valve body includes a valve core assembly 3, and the second end of the transmission rod 504 is connected to the valve core assembly 3 to drive it to move and control the opening of the valve body.

[0052] The present invention solves the problem that the existing regulating valve has poor adjustment accuracy and cannot realize refined production during the control process by reducing the friction resistance during the transmission process; the transmission component has many relatively sliding parts, and the present invention increases lubricity by setting a lubrication cavity in the transmission component; and reduces the friction between the transmission sleeve and the transmission seat by setting a thrust bearing; the present invention reduces the friction resistance at the transmission component, so that the transmission component has a large torque and high transmission efficiency, reduces the control difficulty of the drive device, and improves the control precision of the valve core component. The present invention can accurately control the pressure drop at the wellhead of the gas well between 0.01Mpa-0.1Mpa / d, and reduce the probability of sand spitting or shale gas flow channel closure near the perforation during shale gas production.

[0053] Further, if Figure 3 As shown, an axial gap space 513 is set between the end face of the first end of the transmission sleeve 506 and the bottom end face of the lubrication cavity 509. The lubricating grease in the lubrication cavity 509 can flow to the spiral structure between the transmission rod 504 and the transmission sleeve 506 through the axial gap space 513, thereby improving the lubricity of the spiral structure.

[0054] Further, the spiral structure includes an outer fine pitch trapezoidal thread portion provided on the outer wall of the transmission rod 504 and an inner fine pitch trapezoidal thread portion provided on the inner wall of the transmission sleeve 506, and the outer fine pitch trapezoidal thread portion and the inner fine pitch trapezoidal thread portion are spirally connected. The spiral structure of fine pitch trapezoidal thread effectively improves the tightness of the mutual connection and reduces the friction resistance. The upper part of the transmission rod 504 is in the shape of a screw rod and has a fine pitch trapezoidal thread. In a specific embodiment of the present invention, the overall thread section length of the outer fine pitch trapezoidal thread portion and the inner fine pitch trapezoidal thread portion is 32 mm to 40 mm, and the pitch is less than 3 mm.

[0055] Embodiment 1

[0056] like Figure 2 , Figure 3 As shown, the transmission seat structure includes an upper transmission seat 508 and a lower transmission seat 501 that are detachably connected, and the lower transmission seat 501 is detachably fixedly connected to the valve body by locking screws.

[0057] The first end of the transmission sleeve 506 is rotatably sleeved in the upper transmission seat 508 , a lubrication cavity 509 is provided between the transmission sleeve 506 and the upper transmission seat 508 , and the transmission rod 504 is sealingly slidably penetrated through the bottom end of the upper transmission seat 508 .

[0058] The top end of the lower transmission seat 501 is connected to the outer wall of the upper transmission seat 508, and the bottom end of the lower transmission seat 501 is set to be open, and the cross-sectional size of the opening is larger than the cross-sectional size of the transmission rod 504. The valve core assembly 3 passes through the bottom end of the lower transmission seat and is connected to the second end of the transmission rod 504.

[0059] The transmission rod 504 does not physically contact with any part of the lower transmission seat 501, so that the friction between the two is zero, and the overall friction resistance is reduced by reducing the physical contact. At the same time, the operating rod 304 of the valve core assembly 3 does not physically contact with the lower transmission seat 501, so that the friction between the operating rod 304 and the lower transmission seat 501 is zero.

[0060] Further, if Figure 3 As shown, an inspection inner cavity 505 is set in the lower transmission seat 501, the transmission rod 504 is vertically arranged, the second end of the transmission rod 504 extends into the inspection inner cavity 505, and the second end of the transmission rod 504 is connected to the valve core assembly 3 through a connector 512, so that the transmission rod 504 and the valve core assembly 3 are relatively fixed, and the connector 512 is located in the inspection inner cavity 505.

[0061] Specifically, the cross section of the inspection cavity 505 is arranged in a square shape, and the left and right sides (attached Figure 3 A rod-shaped connecting arm or a plate-shaped side wall is provided on the side (in the direction).

[0062] Further, if Figure 3As shown, a window hole 503 (vertical hole) is provided on the side wall of the lower transmission seat 501, and an indicator plate 502 arranged radially is connected to the transmission rod 504. The indicator plate 502 can pass through the window hole 503 and can move with the transmission rod to indicate the open and closed state of the valve body. The indicator plate 502 is relatively fixed to the transmission rod 504, so that when the transmission rod 504 moves up, the indicator plate 502 moves up synchronously, thereby indicating the open and closed state of the valve body.

[0063] Furthermore, the upper transmission seat 508 is in the shape of a tube sleeve and is vertically arranged, and the lower part of the upper transmission seat 508 is detachably fixedly connected to the top of the lower transmission seat 501 by another locking screw.

[0064] Further, if Figure 3 As shown, an upper step hole portion and a lower step hole portion connected to each other are arranged from top to bottom in the upper transmission seat 508, a convex ring 507 is arranged on the outer wall of the transmission sleeve 506, the aperture size of the upper step hole portion is larger than the outer diameter size of the convex ring 507, thrust bearings 510 are respectively arranged at both ends of the convex ring 507, the lubrication cavity 509 is located in the upper step hole portion, and a grease injection nozzle 511 connecting the lubrication cavity 509 and the external environment is pierced on the side wall of the upper transmission seat 508; the aperture size of the lower step hole portion is larger than the aperture size of the inner cavity of the transmission sleeve and smaller than the outer diameter size of the transmission sleeve; the first end of the transmission rod passes through the lower step hole portion and then penetrates into the inner cavity of the transmission sleeve, and the outer wall of the transmission rod and the inner wall of the lower step hole portion are sealed.

[0065] The convex ring 507 is integrally formed with the transmission sleeve 506. The convex ring 507 is coaxial with the transmission sleeve 506 and radially protrudes from the transmission sleeve 506. A transmission seat top cover is set at the top of the upper step hole portion. A thrust bearing 510 is located between the transmission seat top cover and the convex ring 507. A thrust bearing 510 is located between the convex ring 507 and the bottom surface of the upper step hole portion.

[0066] The transmission rod 504 is sealingly slidably penetrated through the lower step hole portion, thereby avoiding leakage and waste of lubricating oil entering the lower step hole portion.

[0067] Lubricating grease is injected into the grease injection nozzle 511 , and lubricating grease can be added into the lubrication cavity 509 through the grease injection nozzle 511 , which can improve the lubricity of the thrust bearing 510 , thereby reducing the friction resistance during the rotation of the transmission sleeve 506 .

[0068] The transmission sleeve 506 is vertically arranged and rotatably connected to the upper transmission seat 508. The lower end of the transmission sleeve 506 is threadedly matched with the transmission rod 504. When the transmission sleeve 506 rotates, it can pull the transmission rod 504 upward or push the transmission rod 504 downward.

[0069] When the transmission sleeve 506 rotates forward or reversely, the valve core assembly 3 is controlled to slide up and down by the transmission rod 504; the driving device 6 is an electric device, and the connection structure between the transmission sleeve 506 and the motor of the driving device 6 can be a gear box or a transmission belt or other existing technical structures, which will not be repeated here. The driving device 6 can also be a manual rotation device.

[0070] The problem of fine control of the regulating valve is solved in this embodiment, and it is mainly achieved by reducing the friction resistance in the transmission process. Since the stability of the process in which the drive device 6 controls the opening and closing of the valve core assembly 3 will be affected by the friction resistance, and the sliding friction is often smaller than the static friction, the contact area and the friction coefficient of the material will directly determine the values ​​of the sliding friction and the static friction. When the friction coefficient is large, the difference between the sliding friction and the static friction is also large. In this embodiment, firstly, a lubrication cavity 509 is provided, and lubrication oil can be added to the lubrication cavity 509 through a grease injection nozzle 511 to increase lubricity; secondly, a thrust bearing 510 is provided to further reduce the friction between the transmission sleeve 506 and the upper transmission seat 508; secondly, a gap is provided on the end face of the transmission sleeve 506 so that the lubrication oil can reach the fine pitch trapezoidal thread and improve the lubricity of the fine pitch trapezoidal thread; then, in this embodiment, since fine pitch trapezoidal thread is selected instead of thread structure of other structures, the tightness of the mutual connection is effectively improved and the friction resistance is reduced; finally, the transmission rod 504 does not physically contact with the lower transmission seat 501, so that the friction between the two is zero, and the overall friction resistance is reduced by reducing physical contact. Finally, the control difficulty of the drive device 6 is reduced by reducing friction resistance and reducing wear, and the control precision of the valve core assembly 3 is improved.

[0071] The present invention provides a corresponding lubrication cavity and a grease nozzle for adding lubricant, which can effectively reduce friction. In addition, the thrust bearing, the gap left at the lower end of the transmission sleeve, the use of fine-pitch trapezoidal threads, and the reduction of friction between the transmission rod and the transmission seat are all aimed at reducing the friction resistance of the transmission component; the transmission component has a large torque and high transmission efficiency. At the same time, materials with high material strength can be used to make the parts of the transmission component to increase their service life.

[0072] Embodiment 2

[0073] like Figure 2 , Figure 4 , Figure 5 , Figure 6As shown, the valve body includes a valve body shell 1, a valve seat assembly 2, an end sealing assembly 4 and a valve core assembly 3. An air inlet 101 is arranged at the bottom end of the valve body shell 1, an operating port 105 is arranged at the top end of the valve body shell 1, a buffer cavity 102 is arranged between the air inlet 101 and the operating port 105, and an air outlet 103 which can be communicated with the buffer cavity 102 is arranged on the side wall of the valve body shell 1. The buffer cavity 102 is annular, and the operating port 105, the air inlet 101 and the operating port 105 are respectively connected and communicated with each other at the top, bottom and right side of the buffer cavity 102. 101 and an air outlet 103; the air inlet 101, the air outlet 103, the buffer cavity 102 and the operating port 105 are arranged in a T shape, and an air inlet flange 104 is arranged on the valve body shell 1 at the end of the air inlet 101 away from the buffer cavity 102, and the air inlet flange 104 is used to connect the natural gas extraction pipeline; the air outlet flange 107 is arranged on the valve body shell 1 at the end of the air outlet 103 away from the buffer cavity 102, and the air outlet flange 107 is used to connect the natural gas delivery pipeline. At the same time, a through hole is also arranged on the valve body shell 1, and the through hole can connect one of the air inlet 101, the air outlet 103, the buffer cavity 102 and the operating port 105 to the external environment, and a pipe plug 106 is arranged on the through hole, and the pipe plug 106 is used to plug the through hole.

[0074] The throttle hole 205 is always connected to the air inlet 101 of the valve body. The volume of the buffer chamber 102 should be larger than the sum of the apertures of all the throttle holes 205, and also larger than the aperture of the air outlet 103. When the valve core assembly 3 slides axially along the valve seat assembly 2, throttling control of the airflow between the air inlet 101 and the air outlet 103 is realized. The gas discharged from the throttle hole 205 can be decelerated and buffered by the buffer chamber 102, thereby reducing the formation of local airflow turbulence when the air pressure changes, and during the sand spitting process at the wellhead of the shale gas well, the airflow and fine sand cause erosion to the valve core assembly 3 and the valve seat assembly 2 inside the regulating valve, especially the erosion of the valve core assembly 3.

[0075] A valve seat assembly 2 is fixedly arranged at the air inlet 101, and a throttling hole 205 communicating with the air inlet 101 is arranged on the side wall of the valve seat assembly 2 at the buffer chamber 102. The top end of the valve seat assembly 2 is slidably connected to the valve core assembly 3, and the valve core assembly 3 can slidably open and close to control the flow area of ​​the throttling hole 205; the end sealing assembly 4 is connected to the operating port 105, and the valve core assembly 3 is sealingly penetrated through the end sealing assembly 4 and then connected to the transmission rod 504.

[0076] Further, if Figure 4As shown, the valve core assembly 3 includes a sealing ring sleeve 301, a movable valve core sleeve 302 and an operating rod 304; the first end of the operating rod 304 seals and slides through the end sealing assembly 4 and then extends into the lower transmission seat 501, and the first end of the operating rod 304 is fixedly connected to the second end of the transmission rod 504; the second end of the operating rod 304 is connected to the first end of the movable valve core sleeve 302, and the second end of the movable valve core sleeve 302 is provided with a core sleeve groove (forming a cover shape) inwardly, and the core sleeve groove is slidably sleeved on the valve seat assembly 2, and the inner side wall of the core sleeve groove is sleeved with a sealing ring sleeve 301; the transmission rod 504 drives the operating rod 304, the movable valve core sleeve 302 and the sealing ring sleeve 301 to move to adjust the opening of the throttle hole 205. The movable valve core sleeve 302 includes an upper and lower section, and the outer diameter of the lower section is greater than the outer diameter of the upper section. The operating rod 304 is fixedly connected to the upper section of the movable valve core sleeve 302, and the upper end of the operating rod 304 passes through the end sealing assembly 4 and extends out of the valve body.

[0077] Further, if Figure 4 As shown, the end sealing assembly 4 includes an end cover 401, a sliding sleeve 404, an operating sleeve seat 406 and a composite sealing structure. The end cover 401 is buckled on the top of the valve body shell 1, the first end of the operating sleeve seat 406 is sealingly inserted in the operating port 105, and the operating sleeve seat 406 seals through the end cover 401, and the sliding sleeve 404 is set at the second end of the operating sleeve seat 406; the valve core assembly 3 seals and slides through the operating sleeve seat 406 and the sliding sleeve 404, and a composite sealing structure is set between the valve core assembly 3 and the operating sleeve seat 406.

[0078] The lower transmission seat 501 can be connected to the operating sleeve seat 406 by means of a set screw 405 .

[0079] The operating port 105 of the valve body housing 1 has an open edge, the lower part of the operating sleeve 406 is conical, and the conical part can cooperate and seal at the edge of the operating port 105; the operating sleeve 406 can have a wider sealing area, and multiple radial sealing rings can be used at the same time at the lower part of the operating sleeve 406, and the sealing rings located on the conical inclined surface can provide radial sealing force and axial sealing force.

[0080] The end cover 401 is sleeved on the outside of the operating sleeve 406 and is threadedly connected to the valve body shell 1 to tighten the operating sleeve 406 to the operating port 105 .

[0081] Further, if Figure 2 , Figure 4 , Figure 5 , Figure 6As shown, the composite seal structure includes an upper composite seal 403 and a lower composite seal 402. The operating rod 304 is slidably inserted through the operating sleeve seat 406 and the slide sleeve 404. The upper composite seal 403 is arranged between the operating rod 304 and the operating sleeve seat 406, and the gap between the two is sealed by the upper composite seal 403. The movable valve core sleeve 302 is sealingly slidably inserted in the operating sleeve seat 406. The lower composite seal 402 is arranged between the movable valve core sleeve 302 and the operating sleeve seat 406, and the gap between the two is sealed by the lower composite seal 402. The lower composite seal 402 and the upper composite seal 403 are both composite seals, and the composite seals include an annular frame and a sealing packing, and the annular frame is used to support the sealing packing.

[0082] Further, if Figure 2 , Figure 4 , Figure 5 As shown, the upper composite seal 403 includes a first annular skeleton mounted on the operating rod, the cross-section of the first annular skeleton is V-shaped, the V-shaped opening of the first annular skeleton is arranged downward (towards the inner side of the valve body), the first sealing packing unit is arranged at the top end of the first annular skeleton, and the sliding sleeve 404 axially presses against the first sealing packing unit.

[0083] When the slide sleeve 404 is outside the operating rod 304 and screwed onto the operating sleeve seat 406, the end face of the slide sleeve 404 presses the sealing filler, and then the slide sleeve 404 cooperates with the V-shaped frame to extrude the composite seal. Since the opening of the V-shaped frame is set to face away from the slide sleeve 404, and the V-shaped frame and the slide sleeve 404 cooperate to extrude the sealing filler, the reverse support force of the two slopes on the outer side of the V-shaped frame on the sealing filler can be decomposed into two components with mutually perpendicular directions, one of which is in the same radial direction as the operating rod 304. The component in this direction is radially inwardly applied to the operating rod 304, and can enable the sealing filler to improve the sealing force of the sealing filler on the operating rod 304, while the other component is parallel to the axial direction of the operating rod 304, and can effectively compress the sealing filler.

[0084] Further, if Figure 2 , Figure 4 , Figure 6 As shown, the lower composite seal 402 includes two second annular frames sleeved on the movable valve core sleeve, and a second sealing packing unit is arranged between the two second annular frames. The second sealing packing unit is a soft retaining ring with a V-shaped cross section. The sealing packing can be radially deformed under the extrusion of the two support rings to improve the sealing performance.

[0085] In the present invention, the valve core assembly is sealed by sliding up and down, which can reduce the contact area between the valve core assembly 3 and the operating sleeve 406. At the same time, a composite sealing structure is used for sealing between the two. The composite seal has good wear resistance and a small friction coefficient, which effectively reduces the friction resistance of the valve body itself. When the drive device controls the operating rod 304 to rise and fall, the friction resistance between the valve core assembly 3 and other components of the valve body is reduced, and the load of the motor of the drive device will urgently need to decrease, thereby improving the control stability and achieving refined production control accuracy.

[0086] Further, if Figure 4 As shown, a first sleeve inner hole is set inwardly at the first end of the operating sleeve 406, and a second sleeve inner hole is set inwardly at the second end of the operating sleeve 406, and the first sleeve inner hole and the second sleeve inner hole are connected through a connecting hole; the lower composite seal 402 is located in the first sleeve inner hole, the upper composite seal 403 is located in the second sleeve inner hole, the movable valve core sleeve 302 is sealingly slidably penetrated in the first sleeve inner hole, and a balancing chamber is formed between the upper composite seal 403 and the top of the movable valve core sleeve 302; a balancing hole 303 is set through the movable valve core sleeve 302, and the balancing hole 303 can connect the air inlet 101 and the balancing chamber.

[0087] The top end surface of the movable valve core sleeve 302 extends to the balance cavity in the operating sleeve seat 406 and forms the cavity wall of the balance cavity. The balance cavity applies pressure to the movable valve core sleeve 302 toward the valve seat assembly 2.

[0088] The balancing chamber is connected to the air inlet 101, so when the air pressure at the air inlet 101 changes, the air pressure in the balancing chamber also changes synchronously, and the air pressure in the balancing chamber can exert pressure on the upper end face of the movable valve core sleeve 302, thereby balancing the pressure applied by the air inlet 101 to the movable valve core sleeve 302, reducing the adjustment friction resistance of the regulating valve, and thus improving the fineness of the control of the regulating valve.

[0089] Further, if Figure 2 , Figure 4 As shown, the valve seat assembly 2 includes a valve seat body 201 and an air inlet sleeve structure, the valve seat body 201 is fixedly arranged at the air inlet port 101, a valve seat center hole is axially arranged in the valve seat body 201, an air inlet sleeve structure is fixedly sleeved in the valve seat center hole, an air vent is arranged in the air inlet sleeve structure, the top end of the air inlet sleeve structure extends out of the valve seat body 201, and a throttling hole 205 connected with the buffer chamber is arranged on the side wall of the top end of the air inlet sleeve structure, the core sleeve groove is slidably sleeved on the top end of the air inlet sleeve structure, and the air vent can connect the air inlet port 101, the balancing hole 303 and the balancing chamber.

[0090] The air inlet sleeve structure includes an upper sleeve 204 and a lower sleeve 202, which are coaxially arranged in the valve seat center hole of the valve seat body 201, the upper end of the upper sleeve 204 is open, and the lower end is connected to the lower sleeve 202; the lower sleeve 202 is in a straight tube shape, and the lower end of the lower sleeve 202 extends to the middle of the air inlet 101 of the valve body and is connected to the air inlet 101. An outer conical section with a diameter gradually decreasing from top to bottom is arranged on the outer wall of the valve seat body 201, an inner conical surface with an aperture gradually decreasing from top to bottom is arranged in the air inlet 101, and a metal sealing ring 203 is arranged between the outer conical section and the inner conical surface.

[0091] The upper end of the upper sleeve 204 extends out of the valve seat body 201, and a plurality of throttling holes 205 are evenly distributed on the peripheral wall of the extended portion of the upper sleeve 204. The throttling holes 205 are connected to the buffer chamber 102, so that when the valve core assembly 3 is in an open state, all the throttling holes 205 are connected to the air outlet 103 of the valve body through the buffer chamber 102.

[0092] Further, if Figure 2 , Figure 4 As shown, a cushion block 305 is arranged between the top end of the air inlet sleeve structure and the top wall of the core sleeve groove, and a balancing connecting hole is arranged on the cushion block 305, and the balancing connecting hole connects the balancing hole 303 and the vent hole.

[0093] When the operating rod 304 controls the movable valve core sleeve 302 to move downward, the upper sleeve 204 of the valve seat assembly 2 is covered therein by the lower section with a larger diameter. At the same time, the inner diameter of the sealing ring sleeve 301 is equivalent to the outer diameter of the upper sleeve 204. When the sealing ring sleeve 301 slides along the axial direction of the intake sleeve structure, the throttle hole 205 can be completely blocked or completely opened. The sealing of the valve body is achieved by the seal between the intake sleeve structure and the sealing ring sleeve 301. The sealing tightness of the two directly determines the sealing tightness of the entire regulating valve. The intake sleeve structure and the sealing ring sleeve 301 are designed as a detachable structure, so that the upper sleeve 204, the lower sleeve 202 and the sealing ring sleeve 301 are more compact. Since the two need to cooperate to achieve sealing, there are high requirements on the material and processing accuracy of the upper sleeve 204, the lower sleeve 202 and the sealing ring sleeve 301. Therefore, the structure of the three adopts a detachable structure, which can effectively reduce the manufacturing difficulty of the entire regulating valve. At the same time, after the sealing ring sleeve 301 completely blocks the throttle hole 205, the lower end face of the sealing ring sleeve 301 will be in sealing contact with the upper end face of the valve seat body 201, further improving the sealing effect. At the same time, after using multiple throttle holes 205, the pipe diameters of the upper casing 204 and the lower casing 202 can be designed to be larger, thereby increasing the sealing area, thereby reducing the local erosion of the sealing position by natural gas during the transportation process. In addition, the outer diameter of the upper section of the movable valve core sleeve 302 is smaller, which can reduce the sealing difficulty between the upper section of the movable valve core sleeve 302 and the operating sleeve seat 406, and reduce the production cost of the regulating valve.

[0094] In this embodiment, the problem of fine control of the regulating valve is solved, and it is achieved by reducing the friction resistance during the operation of the valve core assembly 3. In this embodiment, a composite seal is set at the valve core assembly 3, mainly to utilize the advantages of the seal's good wear resistance, friction resistance, and resistance to high temperature and high pressure; the valve core assembly 3 of the regulating valve will reciprocate up and down during operation. If an ordinary sealing structure is used, the friction coefficient is large and the wear resistance is poor. Not only before and after the sealing structure is worn, it will affect the precision of the control of the drive device 6. In the embodiment, after redesign and calculation, the materials and sealing forms are selected to greatly reduce friction and have a composite seal with high sealing pressure. The structure includes an annular skeleton and a sealing filler, and the filler is used for sealing. By reducing friction resistance and wear, the control difficulty of the drive device 6 is reduced, and the precision of the control of the valve core assembly 3 is improved.

[0095] The present invention also provides a method for using a sealed cage-type regulating valve, comprising the following steps:

[0096] S1: connecting the air inlet 101 of the sealed cage-type regulating valve to the wellhead of the gas well (existing technology);

[0097] S2: When the sealed cage-type regulating valve is in a closed state, the valve core assembly 3 seals the throttle hole 205 of the valve seat assembly 2, and the air inlet 101 and the air outlet 103 are disconnected;

[0098] Specifically, the lower cover of the movable valve core sleeve 302 is arranged at the upper end of the air inlet casing structure and is sealed by the sealing ring sleeve 301; after the shale gas enters from the air inlet 101, it is cut off at the throttle hole 205, and the shale gas can reach the balance cavity above the movable valve core sleeve through the balance hole 303 in the movable valve core sleeve 302, and exert a pressure opposite to the air inlet direction on the upper end surface of the movable valve core sleeve to balance the pressure of the air inlet;

[0099] S3: When the sealed cage-type regulating valve is opened, the driving device 6 is started, and the valve core assembly 3 is driven to move upward through the transmission assembly 5, so that the throttle hole 205 is opened, and the air inlet 101 is connected with the air outlet 103.

[0100] Specifically, the driving device 6 is started, and the transmission sleeve 506 of the transmission assembly 5 rotates to drive the transmission rod 504 and the operating rod 304 to move upward. The movable valve core sleeve 302 moves upward under the control of the operating rod 304 and makes the throttle hole 205 connect to the buffer chamber 102, so that the shale gas is decelerated after passing through the buffer chamber 102 and is output from the gas outlet 103; during the opening process, the upper composite seal 403 is always sealed between the operating rod 304 and the operating sleeve seat 406; the lower composite seal 402 is always sealed between the movable valve core sleeve 302 and the operating sleeve seat 406.

[0101] As described above, the high-precision controlled sealed cage-type regulating valve and the use method thereof of the present invention have the following advantages:

[0102] Beneficial effects:

[0103] The present invention solves the problem that the existing regulating valve has poor regulating accuracy and cannot realize refined production during the control process by reducing the friction resistance during the transmission process; the transmission component has many relatively sliding parts, and the present invention increases the lubricity by arranging a lubrication cavity in the transmission component; and reduces the friction between the transmission sleeve and the transmission seat by arranging a thrust bearing; the present invention reduces the friction resistance at the transmission component, so that the transmission component has a large torque and high transmission efficiency, reduces the control difficulty of the drive device, and improves the control precision of the valve core component; the present invention can accurately control the pressure drop at the wellhead of the gas well to between 0.01Mpa-0.1Mpa / d, and reduce the probability of sand spitting or shale gas flow channel closure near the perforation during shale gas production.

[0104] The above description is only an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes and modifications made by any person skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A high-precision controlled sealed cage-type regulating valve, characterized in that: It comprises a valve body, a transmission assembly and a driving device, wherein the transmission assembly is connected between the valve body and the driving device, and the driving device controls the opening and closing action of the valve body through the transmission assembly; the transmission assembly comprises a transmission seat structure, a transmission rod and a transmission sleeve; the first end of the transmission sleeve is rotatably sleeved in the transmission seat structure, a lubrication cavity capable of accommodating lubricating grease is provided between the transmission sleeve and the transmission seat structure, a thrust bearing rotatably connecting the transmission sleeve and the transmission seat structure is provided in the lubrication cavity, and the second end of the transmission sleeve is fixedly connected to the driving device so as to rotate therewith; the transmission rod circumferentially fixed and axially movable is passed through the inner cavity of the transmission sleeve from the first end inwardly, the inner wall of the transmission sleeve and the outer wall of the transmission rod are connected by a spiral structure, and the spiral structure converts the rotation of the transmission sleeve into the movement of the transmission rod; the valve body comprises a valve core assembly, and the second end of the transmission rod is connected to the valve core assembly to drive it to move and control the opening of the valve body.

2. The high-precision controlled sealed cage-type regulating valve according to claim 1, characterized in that: An axial gap space is provided between the end surface of the first end of the transmission sleeve and the bottom end surface of the lubrication cavity, and the lubricating grease in the lubrication cavity can flow to the spiral structure between the transmission rod and the transmission sleeve through the axial gap space.

3. The high-precision controlled sealed cage-type regulating valve according to claim 2, characterized in that: The spiral structure includes an outer fine pitch trapezoidal thread portion arranged on the outer wall of the transmission rod and an inner fine pitch trapezoidal thread portion arranged on the inner wall of the transmission sleeve, and the outer fine pitch trapezoidal thread portion is spirally connected with the inner fine pitch trapezoidal thread portion.

4. The high-precision controlled sealed cage-type regulating valve according to claim 3, characterized in that: The transmission seat structure includes an upper transmission seat and a lower transmission seat which are detachably connected, the first end of the transmission sleeve is rotatably sleeved in the upper transmission seat, the lubrication cavity is arranged between the transmission sleeve and the upper transmission seat, and the transmission rod is sealingly slidably passed through the bottom end of the upper transmission seat; the top end of the lower transmission seat is connected to the outer wall of the upper transmission seat, and the bottom end of the lower transmission seat is arranged in an opening, the cross-sectional size of the opening is larger than the cross-sectional size of the transmission rod, and the valve core assembly is connected to the second end of the transmission rod after passing through the bottom end of the lower transmission seat.

5. The high-precision controlled sealed cage-type regulating valve according to claim 4, characterized in that: An upper step hole portion and a lower step hole portion are connected from top to bottom in the upper transmission seat, a convex ring is arranged on the outer wall of the transmission sleeve, the aperture size of the upper step hole portion is larger than the outer diameter size of the convex ring, and the two ends of the convex ring are respectively against the thrust bearing, the lubrication cavity is located in the upper step hole portion, and a grease injection nozzle connecting the lubrication cavity and the external environment is pierced on the side wall of the upper transmission seat; the aperture size of the lower step hole portion is larger than the inner cavity aperture of the transmission sleeve and smaller than the outer diameter size of the transmission sleeve; the first end of the transmission rod passes through the lower step hole portion and then penetrates into the inner cavity of the transmission sleeve, and the outer wall of the transmission rod and the inner wall of the lower step hole portion are sealed.

6. The high-precision controlled sealed cage-type regulating valve according to claim 4, characterized in that: An inspection inner cavity is arranged in the lower transmission seat, and the second end of the transmission rod is connected to the valve core assembly through a connector, and the connector is located in the inspection inner cavity.

7. The high-precision controlled sealed cage-type regulating valve according to claim 4, characterized in that: A window hole is arranged on the side wall of the lower transmission seat, and an indicator plate arranged radially is connected to the transmission rod. The indicator plate can pass through the window hole and can move with the transmission rod to indicate the opening and closing state of the valve body.

8. The high-precision controlled sealed cage-type regulating valve according to claim 4, characterized in that: The valve body includes a valve body shell, a valve seat assembly, an end sealing assembly and the valve core assembly. An air inlet is arranged at the bottom end of the valve body shell, an operating port is arranged at the top end of the valve body shell, a buffer cavity is arranged between the air inlet and the operating port, an air outlet which can be communicated with the buffer cavity is arranged on the side wall of the valve body shell, the valve seat assembly is fixedly arranged at the air inlet, a throttling hole which is communicated with the air inlet is arranged on the side wall of the valve seat assembly at the buffer cavity, the top end of the valve seat assembly is slidably connected to the valve core assembly, and the valve core assembly can slidably open and close to control the flow area of ​​the throttling hole; the end sealing assembly is connected to the operating port, and the valve core assembly is sealingly penetrated through the end sealing assembly and connected to the transmission rod.

9. The high-precision controlled sealed cage-type regulating valve according to claim 8, characterized in that: The valve core assembly includes a sealing ring sleeve, a movable valve core sleeve and an operating rod; the first end of the operating rod seals and slides through the end sealing assembly and then extends into the lower transmission seat, and the first end of the operating rod is fixedly connected to the second end of the transmission rod; the second end of the operating rod is connected to the first end of the movable valve core sleeve, and the second end of the movable valve core sleeve is provided with a core sleeve groove inwardly, and the core sleeve groove is slidably sleeved on the valve seat assembly, and the inner side wall of the core sleeve groove is sleeved with the sealing ring sleeve; the transmission rod drives the operating rod, the movable valve core sleeve and the sealing ring sleeve to move to adjust the opening of the throttle hole.

10. The high-precision controlled sealed cage-type regulating valve according to claim 9, characterized in that: The end sealing assembly includes an end cover, a sliding sleeve, an operating sleeve seat and a composite sealing structure. The end cover is buckled on the top end of the valve body shell, the first end of the operating sleeve seat is seal-inserted in the operating port, and the operating sleeve seat seals through the end cover, and a sliding sleeve is set at the second end of the operating sleeve seat; the valve core assembly seals and slides through the operating sleeve seat and the sliding sleeve, and the composite sealing structure is set between the valve core assembly and the operating sleeve seat.

11. The high-precision controlled sealed cage-type regulating valve according to claim 10, characterized in that: The composite seal structure includes an upper composite seal and a lower composite seal. The operating rod is slidably inserted through the operating sleeve and the slide sleeve, and the upper composite seal is arranged between the operating rod and the operating sleeve. The movable valve core sleeve is seal-slidably inserted in the operating sleeve, and the lower composite seal is arranged between the movable valve core sleeve and the operating sleeve.

12. The high-precision controlled sealed cage-type regulating valve according to claim 11, characterized in that: The upper composite seal includes a first annular skeleton sleeved on the operating rod, the cross-section of the first annular skeleton is V-shaped, the V-shaped opening of the first annular skeleton is set downward, a first sealing filler unit is set at the top of the first annular skeleton, and the slide sleeve axially presses against the first sealing filler unit.

13. The high-precision controlled sealed cage-type regulating valve according to claim 11, characterized in that: The lower composite seal comprises two second annular frames sleeved on the movable valve core sleeve, and a second sealing packing unit is arranged between the two second annular frames.

14. The high-precision controlled sealed cage-type regulating valve according to claim 11, characterized in that: A first sleeve inner hole is arranged inwardly at the first end of the operating sleeve, and a second sleeve inner hole is arranged inwardly at the second end of the operating sleeve, and the first sleeve inner hole and the second sleeve inner hole are connected through a connecting hole; the lower composite seal is located in the first sleeve inner hole, and the upper composite seal is located in the second sleeve inner hole, and the movable valve core sleeve is sealingly slidably arranged in the first sleeve inner hole, and a balancing chamber is formed between the upper composite seal and the top end of the movable valve core sleeve; a balancing hole is arranged through the movable valve core sleeve, and the balancing hole can connect the air inlet and the balancing chamber.

15. The high-precision controlled sealed cage-type regulating valve according to claim 14, characterized in that: The valve seat assembly includes a valve seat body and an air intake sleeve structure, the valve seat body is fixedly arranged at the air inlet, a valve seat center hole is axially penetrated in the valve seat body, the air intake sleeve structure is fixedly sleeved in the valve seat center hole, an air vent is penetrated in the air intake sleeve structure, the top end of the air intake sleeve structure extends out of the valve seat body, and the throttling hole connected with the buffer chamber is arranged on the side wall of the top end of the air intake sleeve structure, the core sleeve groove is slidably sleeved on the top end of the air intake sleeve structure, and the air vent can connect the air inlet, the balancing hole and the balancing chamber.

16. The high-precision controlled sealed cage-type regulating valve according to claim 15, characterized in that: A cushion block is arranged between the top end of the air inlet sleeve structure and the top wall of the core sleeve groove, and a balancing connecting hole is arranged on the cushion block, and the balancing connecting hole connects the balancing hole and the vent hole.

17. The high-precision controlled sealed cage-type regulating valve according to claim 15, characterized in that: An outer conical section with a diameter gradually decreasing from top to bottom is arranged on the outer wall of the valve seat body, an inner conical surface with an aperture gradually decreasing from top to bottom is arranged in the air inlet, and a metal sealing ring is arranged between the outer conical section and the inner conical surface.

18. A method for using the high-precision controlled sealed cage-type regulating valve according to any one of claims 1 to 17, characterized in that: The steps include: S1: Connect the air inlet of the sealed cage type regulating valve to the wellhead of the gas well; S2: When the sealed cage-type regulating valve is in the closed state, the valve core assembly seals the throttle hole of the valve seat assembly, and the air inlet and the air outlet are disconnected; S3: When the sealed cage type regulating valve is opened, the driving device is started, and the valve core assembly is driven upward through the transmission assembly to open the throttle hole, and the air inlet is connected with the air outlet.

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