A supercritical high temperature and high pressure gate valve

Abstract

The present invention discloses a supercritical high-temperature and high-pressure gate valve, which belongs to the technical field of gate valves and solves the problem that a gate plate may have a thermal collision, which may cause it to be locked or stuck with a valve seat, and then cause the gate plate to be damaged when it is separated from the valve seat. It includes a valve body, a multi-stage cylinder located above the valve body, a valve seat fixedly connected to the valve body, a connecting gate plate that can be vertically displaced in the valve body, and end gate plates located on both sides of the connecting gate plate. The multi-stage cylinder includes a piston tube that can be vertically displaced and a piston rod that can be displaced in the piston tube. The lower end of the piston tube is fixedly connected to an inverted U-shaped connecting frame. When the present invention is applied to a supercritical boiler, supercritical water transportation is controlled by a gate valve. The multi-stage cylinder controls the opening and closing of the gate plate to avoid locking or sticking due to thermal expansion. After detection by the locking monitoring system, the connecting gate plate is first released from the jamming, and then the end gate plate is released to prevent damage and reduced sealing.

Description

Technical Field

[0001] The present invention relates to the technical field of gate valves, and in particular to a supercritical high-temperature and high-pressure gate valve. Background Art

[0002] A supercritical boiler is a boiler that operates at supercritical pressure and temperature. Its steam pressure usually exceeds the critical pressure of water by 22.12MPa and the temperature exceeds 374.3℃. This type of boiler does not have a phase change process in which steam and water coexist, so it can only be in the form of a direct-flow boiler, that is, the working fluid passes through each heating surface at one time and is directly converted from feed water to superheated steam. Supercritical boilers have higher thermal efficiency. Compared with subcritical boilers, their thermal efficiency can be increased by about 3% to 8%, significantly reducing coal consumption and emissions. Due to their high efficiency and low emissions, supercritical boilers have been widely used in modern thermal power plants, especially in large power stations that pursue high efficiency and environmental protection.

[0003] The working fluid in the boiler is water, and the critical pressure of water is: 22.115MPa, 374.15℃; at this pressure and temperature, the latent heat of vaporization of water and steam is equal to zero, and there is no two-phase region, that is, water turns into steam continuously and in a single-phase form, which is called the critical point of water. The water at this time becomes supercritical water.

[0004] Supercritical water refers to a special state in which the physical properties of water are between liquid and gas under specific temperature and pressure conditions. When the temperature and pressure of water exceed its critical point (temperature 374.12°C, pressure 22.064MPa), the hydrogen bonds between water molecules are destroyed, the boundary between liquid and gas disappears, and supercritical water is formed. In this state, supercritical water has unique physical properties such as low density, high diffusivity and low surface tension. These properties make it extremely efficient as a solvent in chemical reactions and can significantly improve reaction rates and selectivity.

[0005] Supercritical water needs to be transported in the pipeline of the supercritical boiler, but the pipeline is not always kept unobstructed and blockage may occur. The on-off control in the pipeline is operated by a gate valve, which blocks the supercritical water by inserting its gate at an angle perpendicular to the direction of supercritical water transportation.

[0006] However, supercritical water itself has a high temperature. When the gate is in continuous contact with supercritical water, the gate may experience a thermal collision, which may cause it to lock or get stuck with the valve seat. When the gate is separated from the valve seat, the pneumatic actuator needs to exert a force far beyond the ordinary to separate the gate from the valve seat. Moreover, this separation action is relatively violent, or it may cause obvious collision damage between the gate and the valve seat. If this happens multiple times, it will have a negative impact on the sealing of the gate valve, causing supercritical water to leak through the gate valve.

[0007] Therefore, a supercritical high temperature and high pressure gate valve is proposed to solve or alleviate the above problems. Summary of the invention

[0008] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a supercritical high-temperature and high-pressure gate valve.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] A supercritical high-temperature and high-pressure gate valve comprises a valve body, a multi-stage cylinder located above the valve body, a valve seat fixedly connected to the valve body, a connecting gate plate that can be vertically displaced in the valve body, and end gate plates located on both sides of the connecting gate plate. The multi-stage cylinder comprises a piston tube that can be vertically displaced, and a piston rod that can be displaced in the piston tube. The lower end of the piston tube is fixedly connected to an inverted U-shaped connecting frame. The end gate plates on both sides are respectively fixedly connected to the two ends of the connecting frame and the spacing between the end gate plates on both sides is gradually increased from bottom to top. The lower end of the piston rod passes through the connecting frame and is fixedly connected to the connecting gate plate through the connecting seat. The width of the connecting gate plate is gradually increased from bottom to top. The minimum width of the connecting gate plate is between the maximum spacing and the minimum spacing of the end gate plates on both sides. A locking monitoring system is also included. The locking monitoring system is coupled to the multi-stage cylinder. The locking monitoring system is used to collect thermal data of the end gate plates and the connecting gate plates, judge the thermal expansion and locking degree of the end gate plates and the connecting gate plates, and control the operation of the multi-stage cylinder.

[0011] Preferably, a spacing groove penetrating through two side walls of the connecting gate is formed at the bottom of the connecting gate.

[0012] Preferably, the multi-stage cylinder is arranged vertically downward, and the multi-stage cylinder also includes a front end cover, a middle end cover located above the middle end cover, a rear end cover located above the middle end cover, a front cylinder barrel connected between the front end cover and the middle end cover, a rear cylinder barrel connected between the middle end cover and the rear end cover, a first-stage piston, and a second-stage piston located above the first-stage piston. An air cavity is formed among the front end cover, the middle end cover, the rear end cover, the front cylinder barrel, and the rear cylinder barrel. The first-stage piston and the second-stage piston are both slidably connected in the air cavity. The air cavity is divided into a lower cavity, a middle cavity, and a rear cavity by the first-stage piston and the second-stage piston. The upper end of the piston tube is fixedly connected to the bottom of the first-stage piston. The first-stage piston is annular, and the inner diameter of the first-stage piston is the same as the inner diameter of the piston tube. The upper end of the piston rod is fixedly connected to the bottom surface of the second-stage piston, and the lower end of the piston rod passes through the first-stage piston and the piston tube to the outside. The front end cover is fixedly connected with a front tube connected to the lower cavity, the middle end cover is fixedly connected with a middle tube connected to the middle cavity, and the rear end cover is fixedly connected with a rear tube connected to the rear cavity. The front tube, the middle tube, and the rear tube can be opened and closed, and the front tube, the middle tube, and the rear tube are respectively connected to the first air compressor, the second air compressor, and the third air compressor.

[0013] Preferably, the locking monitoring system includes a thermal image acquisition module, a data processing module, and a control module. The thermal image acquisition module is used to collect thermal images of the end gate plate and the connecting gate plate and associate the temperatures of each position in the thermal image and then feed back to the data processing module. The data processing module is used to estimate whether the end gate plate and the connecting gate plate are thermally expanded and locked with the valve seat and feed back the output result to the control module. The control module uses the feedback output result to control the multi-stage cylinder to drive the piston rod and piston tube displacement in different ways.

[0014] Preferably, the thermal image acquisition module is used to acquire the thermal images of the end gate and the connecting gate and associate the temperature of each position in the thermal image and then feed it back to the data processing module, including the following steps:

[0015] Take thermal images of the end gate and the connecting gate by using a thermal imager;

[0016] Establish spatial coordinates in the thermal image, and associate the spatial coordinates with the temperature to obtain the temperature (x, y, z) at each coordinate position.

[0017] Preferably, the data processing module is used to estimate whether the end gate and the connecting gate are thermally expanded and locked with the valve seat and to feed back the output result to the control module, including the following steps:

[0018] Obtain the size of the valve seat, the size of the end gate plate and the connecting gate plate, the material of the end gate plate and the connecting gate plate, the linear expansion coefficient corresponding to the end gate plate and the connecting gate plate, and the initial temperature of the end gate plate and the connecting gate plate;

[0019] Calculate the temperature change of the end gate and the connecting gate ;

[0020] Calculate the dimensional changes of the end gate and the connecting gate due to thermal expansion ,in, is the linear expansion coefficient of the end gate and the connecting gate, The dimensions of the end gate and the connecting gate;

[0021] Calculate the size changes of the position in the length direction, the position in the width direction, and the position in the thickness direction. , the size change of the position in the width direction , the size change of the position in the thickness direction ,in, , , , , , are the size ranges of the end gate and the connecting gate in the length, width and thickness directions respectively;

[0022] Setting the expansion threshold , determine whether the size change is greater than the expansion threshold If it is greater than, it is considered that thermal expansion has occurred and the valve seat has locked; otherwise, it is considered that thermal expansion has not occurred and the valve seat has locked.

[0023] Preferably, the control module is coupled to the first air compressor, the second air compressor, and the third air compressor, and the front pipe, the middle pipe, and the rear pipe are respectively connected to the first solenoid valve, the second solenoid valve, and the third solenoid valve, the first solenoid valve is electrically connected through a first relay, the second solenoid valve is electrically connected through a second relay, and the third solenoid valve is electrically connected through a third relay, the output end of the control module is respectively coupled to the controlled ends of the first solenoid valve, the second solenoid valve, and the third solenoid valve, and the control module includes an integrated circuit of an STM32F103RCT6 embedded-microcontroller.

[0024] Preferably, it also includes a valve connecting sleeve integrally formed on the valve body, a valve bonnet fixedly connected in the valve connecting sleeve, and a bracket fixedly connected between the valve connecting sleeve and the valve bonnet and located above the valve bonnet, the outer peripheral wall of the bracket is fixedly connected with a mounting seat located above the bracket through a connecting handle, the mounting seat is fixedly connected with a mounting frame through connecting bolts, the multi-stage cylinder is vertically fixedly connected to the mounting frame through a connecting rod, the piston tube passes through the mounting frame, the mounting seat, the valve bonnet to the valve connecting sleeve, and a sealing ring is embedded between the bottom surface of the bracket and the pressure cap.

[0025] Preferably, the top surface of the bracket is provided with a gasket sleeved on the outer ring of the valve cap, the outer ring of the valve cap is provided with a pre-tightening plate located above the gasket, and the pre-tightening plate is threadedly connected with a fixing bolt that presses against the top surface of the gasket, and a filler is filled between the upper inner ring of the valve cap and the piston tube, the upper outer ring of the valve cap is provided with a support frame, the outer ring of the piston tube is provided with a stuffing sleeve that presses against the stuffing, and the outer ring of the piston tube is provided with a pressure plate that can slide vertically and press against the upper end of the stuffing sleeve, and the support frame is rotatably connected with a live bolt, the live bolt can penetrate the pressure plate, and the live bolt penetrates the pressure plate and is threadedly connected to the nut.

[0026] The present invention has the following beneficial effects:

[0027] The present invention is used to control the flow of supercritical water in the pipeline, and the gate valve is used to completely block or completely open the supercritical water. The operation of the gate valve depends on the precise control of the multi-stage cylinder, which is responsible for driving the piston rod and the piston tube, thereby driving the movement of the connecting gate and the end gate. When it is necessary to block the water flow, the multi-stage cylinder will work together to lower the connecting gate and the end gate to the closed position, or first lower the end gate, and then guide the connecting gate to be embedded between the end gates to achieve sealing;

[0028] Due to the high temperature characteristics of supercritical water, it will exchange heat with the end gate and the connecting gate, which may cause these components to lock or jam due to thermal expansion. For this reason, the present invention is equipped with a jam monitoring system, which can detect and judge the jam or jam situation in time. Once the problem is detected, the multi-stage cylinder will operate first, so that the piston rod drives the connecting gate to move upward. Due to the width design of the connecting gate, this will release the jam state between the valve seat, the end gate and the connecting gate. Subsequently, the multi-stage cylinder controls the piston tube to move the end gate upward, ensuring that the gate can be separated from the valve seat smoothly to avoid damage caused by forced separation.

[0029] This not only avoids collision and damage between the gate plate and the valve seat, but also ensures that the sealing performance of the gate plate will not be significantly reduced when the gate plate recloses the flow channel in the valve body. In this way, the present invention enhances reliability and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 It is a structural schematic diagram of the present invention;

[0032] Figure 2 for Figure 1 The enlarged view of point A in the middle;

[0033] Figure 3 It is a simplified structural diagram of the multi-stage cylinder in the present invention;

[0034] Figure 4 It is a structural block diagram of the locking monitoring system in the present invention.

[0035] 1. Valve body; 2. Valve connecting sleeve; 3. Valve bonnet; 4. Piston tube; 5. Connecting frame; 6. End gate; 7. Piston rod; 8. Connecting seat; 9. Connecting gate; 10. Spacing groove; 11. Valve seat; 12. Sealing ring; 13. Bracket; 14. Gasket; 15. Pre-tightening plate; 16. Tightening bolt; 17. Support frame; 18. Packing; 19. Packing sleeve; 20. Pressing plate; 21. Visible bolt; 22. Nut; 23. Connecting handle; 24. Mounting seat; 25. Connecting bolt; 26. Mounting frame; 27. Connecting rod; 28. Front cover; 29. ​​Middle cover ; 30. Rear end cover; 31. Front cylinder; 32. Rear cylinder; 33. Front pipe; 34. Middle pipe; 35. Rear pipe; 36. Primary piston; 37. Secondary piston; 38. Lower chamber; 39. Middle chamber; 40. Rear chamber; 41. Thermal image acquisition module; 42. Data processing module; 43. Control module; 44. First relay; 45. Second relay; 46. Third relay; 47. First solenoid valve; 48. Second solenoid valve; 49. Third solenoid valve; 50. First air compressor; 51. Second air compressor; 52. Third air compressor. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0039] In the description of the present invention, it should be understood that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of the invention is conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0040] Furthermore, the terms “first”, “second”, “third”, etc. are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.

[0041] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] A supercritical high temperature and high pressure gate valve, such as Figure 1 and Figure 2 As shown, it includes a valve body 1, a multi-stage cylinder located above the valve body 1, a valve seat 11 fixedly connected to the valve body 1, a connecting gate plate 9 that can be vertically displaced in the valve body 1, and end gate plates 6 located on both sides of the connecting gate plate 9. The multi-stage cylinder includes a piston tube 4 that can be vertically displaced, and a piston rod 7 that can be displaced in the piston tube 4. The lower end of the piston tube 4 is fixedly connected to an inverted U-shaped connecting frame 5, and the end gate plates 6 on both sides are respectively fixedly connected to the two ends of the connecting frame 5 and the spacing between the end gate plates 6 on both sides is gradually increased from bottom to top. The lower end of the piston rod 7 passes through the connecting frame 5 and is fixedly connected to the connecting gate plate 9 through a connecting seat 8. The width of the connecting gate plate 9 is gradually increased from bottom to top. The minimum width of the connecting gate plate 9 is between the maximum spacing and the minimum spacing of the end gate plates 6 on both sides. The bottom of the connecting gate plate 9 is provided with a spacing groove 10 that passes through its two side walls.

[0043] like Figure 4 As shown, it also includes a locking monitoring system, which is coupled to the multi-stage cylinder. The locking monitoring system is used to collect thermal data of the end gate plate 6 and the connecting gate plate 9, determine the thermal expansion and locking degree of the end gate plate 6 and the connecting gate plate 9, and control the operation of the multi-stage cylinder.

[0044] The locking monitoring system includes a thermal image acquisition module 41, a data processing module 42, and a control module 43. The thermal image acquisition module 41 is used to collect thermal images of the end gate plate 6 and the connecting gate plate 9 and correlate the temperatures of each position in the thermal image and then feed back to the data processing module 42. The data processing module 42 is used to estimate whether the end gate plate 6 and the connecting gate plate 9 are thermally expanded and locked with the valve seat 11, and feed back the output results to the control module 43. The control module 43 uses the feedback output results to control the multi-stage cylinder to drive the piston rod 7 and the piston tube 4 to move in different ways.

[0045] Preferably, the thermal image acquisition module 41 is used to collect the thermal images of the end gate 6 and the connecting gate 9 and associate the temperature of each position in the thermal image and then feed it back to the data processing module 42, including the following steps:

[0046] Take thermal images of the end gate plate 6 and the connecting gate plate 9 by using a thermal imager;

[0047] The spatial coordinates are established in the thermal image, and the spatial coordinates are associated with the temperature to obtain the temperature x, y, z at each coordinate position.

[0048] Preferably, the data processing module 42 is used to estimate whether the end gate plate 6 and the connecting gate plate 9 are thermally expanded and locked with the valve seat 11 and to feed back the output result to the control module 43, including the following steps:

[0049] Obtain the size of the valve seat 11, the size of the end gate plate 6 and the connecting gate plate 9, the material of the end gate plate 6 and the connecting gate plate 9, the linear expansion coefficient corresponding to the end gate plate 6 and the connecting gate plate 9, and the initial temperature of the end gate plate 6 and the connecting gate plate 9;

[0050] Calculate the temperature change of the end gate 6 and the connecting gate 9 ;

[0051] Calculate the dimensional changes of the end gate 6 and the connecting gate 9 due to thermal expansion ,in, is the linear expansion coefficient corresponding to the end gate plate 6 and the connecting gate plate 9, The dimensions of the end gate 6 and the connecting gate 9;

[0052] Calculate the size changes of the position in the length direction, the position in the width direction, and the position in the thickness direction. , the size change of the position in the width direction , the size change of the position in the thickness direction ,in, , , , , , The size ranges of the end gate plate 6 and the connecting gate plate 9 in the length, width and thickness directions respectively;

[0053] Setting the expansion threshold , determine whether the size change is greater than the expansion threshold If it is greater than, it is determined that thermal expansion occurs and the valve seat 11 is locked. Otherwise, it is determined that thermal expansion does not occur and the valve seat 11 is locked.

[0054] When the present invention is actually applied in a supercritical boiler, supercritical water is transported in a pipeline, and the gate valve is used to block the supercritical water in the pipeline. Since the gate valve only plays two roles in the pipeline: fully open and fully blocked, when switching between these two situations, it is essentially controlled by a multi-stage cylinder. The multi-stage cylinder controls the piston rod and the piston tube to simultaneously drive the connecting gate plate and the end gate plate to move downward, or first drives the end gate plate to move downward, and then makes the connecting gate plate embedded between the end gate plates on both sides, thereby completing the gate valve's blocking effect on supercritical water. Since the supercritical water has a high temperature, it acts on the end gate plate and the connecting gate plate. The end gate plate and the connecting gate plate Heat exchange occurs with supercritical water, causing the end gate and the connecting gate to heat up and expand thermally, thereby causing the end gate, the connecting gate and the valve seat to become locked or stuck. After detection by the locking monitoring system, it can be determined that the locking or sticking situation has occurred. The multi-stage cylinder can preferentially control the piston rod to drive the connecting gate to move upward, and due to the width setting of the connecting gate, the valve seat, the end gate and the connecting gate will no longer be stuck. Then the multi-stage cylinder controls the piston tube to drive the end gate to move upward. In this way, when the gate is separated from the valve seat, it is not easy to be forced to separate and then be damaged by collision, which avoids the problem of a significant decrease in sealing when the gate closes the flow channel in the valve body again.

[0055] like Figure 1As shown, it also includes a valve connecting sleeve 2 integrally formed on the valve body 1, a valve bonnet 3 fixedly connected in the valve connecting sleeve 2, and a bracket 13 fixedly connected between the valve connecting sleeve 2 and the valve bonnet 3 and located above the valve bonnet 3. A mounting seat 24 located above the bracket 13 is fixedly connected to the outer peripheral wall of the bracket 13 through a connecting handle 23, and a mounting frame 26 is fixedly connected to the mounting seat 24 through a connecting bolt 25. The multi-stage cylinder is vertically fixedly connected to the mounting frame 26 through a connecting rod 27. The piston tube 4 passes through the mounting frame 26, the mounting seat 24, the valve bonnet 3 to the valve connecting sleeve 2. A sealing ring 12 is embedded between the bottom surface of the bracket 13 and the pressure cap. The top surface of the bracket 13 is provided with a sleeve mounted on The gasket 14 of the outer ring of the valve bonnet 3 is provided with a pre-tightening plate 15 located above the gasket 14 on the outer ring of the valve bonnet 3, and the pre-tightening plate 15 is threadedly connected with a fixing bolt 16 that presses against the top surface of the gasket 14. A packing 18 is filled between the upper inner ring of the valve bonnet 3 and the piston tube 4, and the upper outer ring of the valve bonnet 3 is provided with a support frame 17, and the outer ring of the piston tube 4 is provided with a packing sleeve 19 that presses against the packing 18. The outer ring of the piston tube 4 is provided with a pressure plate 20 that can slide vertically and press against the upper end of the packing sleeve 19, and a live bolt 21 is rotatably connected to the support frame 17, and the live bolt 21 can penetrate the pressure plate 20, and the live bolt 21 penetrates the pressure plate 20 and is threadedly connected to the nut 22.

[0056] The above structure ensures that the gate valve has a good sealing effect. First, the multi-stage cylinder can be installed on the mounting seat 24 through the connecting rod 27 and the mounting frame 26, and the mounting seat 24 itself is connected between the valve connecting sleeve 2 and the valve bonnet 3 through the connecting handle 23 and the bracket 13. The sealing ring 12 between the valve connecting sleeve 2 and the valve bonnet 3 is to ensure the sealing of the gap generated after the two are connected. The pre-tightening plate 15 is used as a support to make the tightening bolt 16 press against the gasket 14 below, so that the bracket 13 and the valve bonnet 3 are connected. The gap at the upper end of the valve bonnet 3 can also be closed. If it is necessary to ensure the sealing effect between the piston tube 4 and the valve bonnet 3, the packing 18 is filled between the outer ring of the piston tube 4 and the upper inner ring of the valve bonnet 3, and then pressed down through the packing sleeve 19. In order to ensure that the packing sleeve 19 is always pressed tightly, the pressure plate 20 will pass through the live bolt 21, and the nut 22 will be threadedly connected to the live bolt 21, and then the nut 22 will press the pressure plate 20 downward, so that the pressure plate 20 can apply a downward force to the packing sleeve 19.

[0057] like Figure 1 and Figure 3As shown, the multi-stage cylinder is vertically arranged downward, and the multi-stage cylinder also includes a front end cover 28, a middle end cover 29 located above it, and a rear end cover 30 located above the middle end cover 29, a front cylinder barrel 31 connected between the front end cover 28 and the middle end cover 29, a rear cylinder barrel 32 connected between the middle end cover 29 and the rear end cover 30, a first-stage piston 36, and a second-stage piston 37 located above the first-stage piston 36. An air cavity is formed among the front end cover 28, the middle end cover 29, the rear end cover 30, the front cylinder barrel 31, and the rear cylinder barrel 32. The first-stage piston 36 and the second-stage piston 37 are both slidably connected in the air cavity. The air cavity is divided into a lower cavity 38, a middle cavity 39, and a rear cavity 40 by the first-stage piston 36 and the second-stage piston 37. The upper end of the piston tube 4 is fixedly connected to the first piston The bottom surface of the plug 36 and the lower end of the piston tube 4 penetrate the air cavity to the outside world. The first-stage piston 36 is annular, and the inner diameter of the first-stage piston 36 is the same as the inner diameter of the piston tube 4. The upper end of the piston rod 7 is fixedly connected to the bottom surface of the secondary piston 37 and the lower end of the piston rod 7 penetrates the first-stage piston 36 and the piston tube 4 to the outside world. The front end cover 28 is fixedly connected with the front tube 33 connected to the lower cavity 38, the middle end cover 29 is fixedly connected with the middle tube 34 connected to the middle cavity 39, and the rear end cover 30 is fixedly connected with the rear tube 35 connected to the rear cavity 40. The front tube 33, the middle tube 34, and the rear tube 35 can be set to be on and off. The front tube 33, the middle tube 34, and the rear tube 35 are respectively connected to the first air compressor 50, the second air compressor 51, and the third air compressor 52.

[0058] The control module 43 is coupled to the first air compressor 50, the second air compressor 51, and the third air compressor 52. The front pipe 33, the middle pipe 34, and the rear pipe 35 are respectively connected to the first solenoid valve 47, the second solenoid valve 48, and the third solenoid valve 49. The first solenoid valve 47 is electrically connected through the first relay 44, the second solenoid valve 48 is electrically connected through the second relay 45, and the third solenoid valve 49 is electrically connected through the third relay 46. The output end of the control module 43 is respectively coupled to the controlled ends of the first solenoid valve 47, the second solenoid valve 48, and the third solenoid valve 49. The control module 43 includes an integrated circuit of an STM32F103RCT6 embedded-microcontroller.

[0059] When the multi-stage cylinder is working, if the volume of the lower chamber 38, the middle chamber 39, and the rear chamber 40 needs to remain unchanged, the first solenoid valve 47, the second solenoid valve 48, or the third solenoid valve 49 can keep the front tube 33, the middle tube 34, and the rear tube 35 blocked. If the volume of the lower chamber 38, the middle chamber 39, or the rear chamber 40 needs to be increased, it is only necessary to make the first solenoid valve 47, the second solenoid valve 48, or the third solenoid valve 49 keep the front tube 33, the middle tube 34, and the rear tube 35 unblocked, and then start the first air compressor 50, the second air compressor 51, and the third air compressor 52 to work and press the outside air into them. Only by coordinating the volume changes of the lower chamber 38, the middle chamber 39, or the rear chamber 40, the position of the first-stage piston 36 and the second-stage piston 37 can be adjusted, and then the piston rod 7 and the piston tube 4 can be driven to move up and down.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A supercritical high temperature and high pressure gate valve, characterized in that: The invention comprises a valve body (1), a multi-stage cylinder located above the valve body (1), a valve seat (11) fixedly connected to the valve body (1), a connecting gate plate (9) vertically displaceable in the valve body (1), and end gate plates (6) located on both sides of the connecting gate plate (9), wherein the multi-stage cylinder comprises a piston tube (4) vertically displaceable and a piston rod (7) displaceable in the piston tube (4), the lower end of the piston tube (4) is fixedly connected to an inverted U-shaped connecting frame (5), the end gate plates (6) on both sides are respectively fixedly connected to the two ends of the connecting frame (5), and the spacing between the end gate plates (6) on both sides is 1 / 4 from the bottom to the top. The piston rod (7) is arranged to gradually increase in width from bottom to top, the lower end of the piston rod (7) passes through the connecting frame (5) and is fixedly connected to a connecting gate plate (9) through a connecting seat (8), the width of the connecting gate plate (9) is arranged to gradually increase from bottom to top, the minimum width of the connecting gate plate (9) is between the maximum spacing and the minimum spacing of the end gate plates (6) on both sides, and also includes a locking monitoring system, the locking monitoring system is coupled to the multi-stage cylinder, the locking monitoring system is used to collect thermal data of the end gate plates (6) and the connecting gate plates (9), determine the thermal expansion and locking degree of the end gate plates (6) and the connecting gate plates (9), and control the operation of the multi-stage cylinder; The multi-stage cylinder is arranged vertically downward, and further comprises a front end cover (28), a middle end cover (29) located above the front end cover, a rear end cover (30) located above the middle end cover (29), a front cylinder barrel (31) connected between the front end cover (28) and the middle end cover (29), a rear cylinder barrel (32) connected between the middle end cover (29) and the rear end cover (30), a first-stage piston (36), and a second-stage piston (37) located above the first-stage piston (36). An air cavity is formed among the front end cover (28), the middle end cover (29), the rear end cover (30), the front cylinder barrel (31), and the rear cylinder barrel (32). The first-stage piston (36) and the second-stage piston (37) are both slidably connected in the air cavity. The air cavity is divided into a lower cavity (38), a middle cavity (39), and a rear cavity (40) by the first-stage piston (36) and the second-stage piston (37). The upper end of the piston tube (4) is fixedly connected to the bottom of the first-stage piston (36). The first-stage piston (36) is annular, and the inner diameter of the first-stage piston (36) is the same as the inner diameter of the piston tube (4). The upper end of the piston rod (7) is fixedly connected to the bottom surface of the second-stage piston (37), and the lower end of the piston rod (7) passes through the first-stage piston (36) and the piston tube (4) to the outside. The front end cover (28) is fixedly connected to a front tube (33) communicating with the lower chamber (38), the middle end cover (29) is fixedly connected to a middle tube (34) communicating with the middle chamber (39), and the rear end cover (30) is fixedly connected to a rear tube (35) communicating with the rear chamber (40). The front tube (33), the middle tube (34), and the rear tube (35) can be switched on and off. The front tube (33), the middle tube (34), and the rear tube (35) are respectively connected to a first air compressor (50), a second air compressor (51), and a third air compressor (52); The locking monitoring system comprises a thermal image acquisition module (41), a data processing module (42), and a control module (43); the thermal image acquisition module (41) is used to acquire thermal images of the end gate plate (6) and the connecting gate plate (9), and correlate the temperatures of various positions in the thermal images and then feed them back to the data processing module (42); the data processing module (42) is used to estimate whether the end gate plate (6) and the connecting gate plate (9) are thermally expanded and locked with the valve seat (11), and feed back the output result to the control module (43); the control module (43) is used to control the multi-stage cylinder to drive the piston rod (7) and the piston tube (4) to move in different ways based on the output result fed back.

2. A supercritical high temperature and high pressure gate valve according to claim 1, characterized in that: The bottom of the connecting gate plate (9) is provided with a spacing groove (10) penetrating through the two side walls thereof.

3. A supercritical high temperature and high pressure gate valve according to claim 1, characterized in that: The thermal image acquisition module (41) is used to acquire thermal images of the end gate plate (6) and the connection gate plate (9), and correlate the temperatures of various positions in the thermal images and then feed them back to the data processing module (42), comprising the following steps: Taking thermal images of the end gate plate (6) and the connecting gate plate (9) by means of a thermal imager; The spatial coordinates are established in the thermal image, and the spatial coordinates are associated with the temperature to obtain the temperature T (x, y, z) at each coordinate position.

4. A supercritical high temperature and high pressure gate valve according to claim 3, characterized in that: The data processing module (42) is used to estimate whether the end gate plate (6) and the connecting gate plate (9) are thermally expanded and locked with the valve seat (11) and to feed back the output result to the control module (43), and comprises the following steps: Obtain the size of the valve seat (11), the size of the end gate plate (6) and the connecting gate plate (9), the material of the end gate plate (6) and the connecting gate plate (9), the linear expansion coefficient corresponding to the end gate plate (6) and the connecting gate plate (9), and the initial temperature of the end gate plate (6) and the connecting gate plate (9) ; Calculate the temperature change of the end gate (6) and the connecting gate (9) ; Calculate the dimensional changes due to thermal expansion of the end gate (6) and the connecting gate (9) ,in, is the linear expansion coefficient corresponding to the end gate plate (6) and the connecting gate plate (9), The dimensions of the end gate plate (6) and the connecting gate plate (9); Calculate the size changes of the position in the length direction, the position in the width direction, and the position in the thickness direction. , the size change of the position in the width direction , the size change of the position in the thickness direction ,in, , , , , , The size ranges of the end gate plate (6) and the connecting gate plate (9) in the length, width and thickness directions respectively; Setting the expansion threshold , determine whether the size change is greater than the expansion threshold If it is greater than, it is determined that thermal expansion has occurred and the valve seat (11) has locked. Otherwise, it is determined that thermal expansion has not occurred and the valve seat (11) has locked.

5. The supercritical high-temperature and high-pressure gate valve according to claim 1, characterized in that: The control module (43) is coupled to a first air compressor (50), a second air compressor (51), and a third air compressor (52); the front pipe (33), the middle pipe (34), and the rear pipe (35) are respectively connected to a first solenoid valve (47), a second solenoid valve (48), and a third solenoid valve (49); the first solenoid valve (47) is electrically connected via a first relay (44); the second solenoid valve (48) is electrically connected via a second relay (45); and the third solenoid valve (49) is electrically connected via a third relay (46); an output end of the control module (43) is respectively coupled to controlled ends of the first solenoid valve (47), the second solenoid valve (48), and the third solenoid valve (49); and the control module (43) comprises an integrated circuit of an STM32F103RCT6 embedded-microcontroller.

6. The supercritical high-temperature and high-pressure gate valve according to claim 1, characterized in that: It also comprises a valve connecting sleeve (2) integrally formed on the valve body (1), a valve bonnet (3) fixedly connected in the valve connecting sleeve (2), and a bracket (13) fixedly connected between the valve connecting sleeve (2) and the valve bonnet (3) and located above the valve bonnet (3); a mounting seat (24) located above the bracket (13) is fixedly connected to the outer peripheral wall of the bracket (13) via a connecting handle (23); a mounting frame (26) is fixedly connected to the mounting seat (24) via a connecting bolt (25); the multi-stage cylinder is vertically fixedly connected to the mounting frame (26) via a connecting rod (27); the piston tube (4) passes through the mounting frame (26), the mounting seat (24), the valve bonnet (3) and the valve connecting sleeve (2); and a sealing ring (12) is embedded between the bottom surface of the bracket (13) and the pressure cap.

7. A supercritical high temperature and high pressure gate valve according to claim 6, characterized in that: The top surface of the bracket (13) is provided with a gasket (14) sleeved on the outer ring of the valve cap (3); the outer ring of the valve cap (3) is sleeved with a pre-tightening plate (15) located above the gasket (14); the pre-tightening plate (15) is threadedly connected with a fixing bolt (16) for pressing the top surface of the gasket (14); a packing (18) is filled between the upper inner ring of the valve cap (3) and the piston tube (4); the upper outer ring of the valve cap (3) is sleeved with a support frame (17); the outer ring of the piston tube (4) is sleeved with a packing sleeve (19) for pressing the packing (18); the outer ring of the piston tube (4) is provided with a pressure plate (20) that can slide vertically and press the upper end of the packing sleeve (19); the support frame (17) is rotatably connected with a movable bolt (21); the movable bolt (21) can penetrate the pressure plate (20) and is threadedly connected to a nut (22) after penetrating the pressure plate (20).

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