A safer main steam valve actuator

Abstract

The application discloses a safer main steam valve actuator, which comprises a hydraulic control block assembly, a conversion plate assembly installed at the bottom of the hydraulic control block assembly and an oil cylinder installed at the bottom of the conversion plate assembly, a shell is arranged at the bottom of the oil cylinder, bolts are arranged through the top edge of the oil cylinder and the shell, a connecting plate is connected to the bottom of the shell, a spring is arranged in the shell, a spring seat is connected to the bottom of the spring inside the shell, a bearing is installed on the outer side wall of the spring seat, a test piston is arranged at the top of the inner cavity of the oil cylinder, a piston rod is arranged at the bottom of the inner cavity of the oil cylinder, and a pressing plate is arranged on the outer side of the bottom end of the piston rod. Through the arrangement of the piston rod and the test piston, the movable test function can be realized, and the safety hidden danger and the great quality loss caused by the non-stop production due to the stroke switch, the proximity switch, the displacement sensor signal problem, the line or the clamping piece problem during the online test of the unit operation can be effectively solved.

Description

Technical Field

[0001] This invention relates to the field of main steam valve technology, specifically to a safer main steam valve actuator. Background Technology

[0002] The main steam valve is a valve that allows main steam to enter the steam turbine and can be quickly closed. It serves as a protective mechanism in case of emergency during turbine operation. Its tightness and flexibility directly affect the safe operation of the steam turbine generator. The main steam valve is generally driven by a hydraulic actuator, which is responsible for opening the main steam valve. Steam turbines are generally required to operate continuously for more than 8,000 hours. The main steam valve is normally open during turbine unit operation. The function of the main steam valve also requires that it can close within 0.2 seconds when the unit needs to trip and shut down, instantly cutting off the steam passage to the turbine. Therefore, in addition to ensuring rapid closure, the main steam valve actuator must also ensure that the main steam valve and actuator do not jam. A mobility test is required during turbine unit operation.

[0003] Currently, the high-pressure fire-resistant oil and high-pressure anti-wear oil actuators on the market come in various forms and have varying levels of technology. In particular, the mobility test function relies on electronic feedback to complete the travel of the mobility test, which poses a significant safety hazard. When the electronic switch is de-energized, the signal line becomes loose, the signal receiving card is damaged, or the proximity switch is damaged, it can cause unauthorized shutdowns and result in significant production losses. Summary of the Invention

[0004] The purpose of this invention is to provide a safer main steam valve actuator to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a safer main steam valve actuator, comprising a hydraulic control block assembly, a conversion plate assembly installed at the bottom of the hydraulic control block assembly, and a cylinder installed at the bottom of the conversion plate assembly. The cylinder has a housing at its bottom, and a bolt is threaded through the cylinder and the top edge of the housing. A connecting plate is connected to the bottom of the housing. A spring is installed inside the housing, and a spring seat is connected to the bottom of the spring inside the housing. A bearing is installed on the outer wall of the spring seat. A test piston is installed at the top of the cylinder's inner cavity, and a piston rod is installed at the bottom of the cylinder's inner cavity. A pressure plate is fitted around the bottom end of the piston rod, and a mounting nut is fitted below the pressure plate. A washer is placed below the mounting nut. A round nut is fitted around the bottom of the piston rod, and a coupling is installed around the round nut. A displacement sensor assembly is installed on one side of the housing, a limit switch assembly is installed on the other side of the housing, and an electrical junction box assembly is installed on the front wall of the housing.

[0006] Preferably, a first Gladius ring and a second Gladius ring are respectively fitted on the top of the piston rod and the outer wall of the test piston. A first guide belt and a second guide belt are respectively provided above the first Gladius ring and the second Gladius ring. The top of the piston rod and the test piston are slidably connected to the inner wall of the oil cylinder.

[0007] Preferably, a base plate is installed at the bottom of the cylinder, and a guide sleeve is provided through the center of the base plate. Both the base plate and the guide sleeve are annular, and the piston rod is inserted into the cylinder through the base plate and the guide sleeve.

[0008] Preferably, a copper sleeve is movably inserted into the inner wall of the connecting plate, a fixing plate is provided at the bottom of the copper sleeve, a fixing nut is provided at the bottom edge of the connecting plate, an adjusting screw is provided through the edge of the connecting plate, the fixing plate is connected to the connecting plate by the screw, and the upper surface of the fixing plate is in contact with the bottom of the copper sleeve.

[0009] Preferably, the top of the adjusting screw passes through the connecting plate and contacts the bottom of the spring seat, the adjusting screw passes through the fixing nut and the connecting plate in sequence, and the adjusting screw is threadedly connected to the fixing nut.

[0010] Preferably, threaded holes are provided on both sides of the pressure plate, and a locking nut is fitted on the outside of the threaded hole. A first connecting rod is connected inside the threaded hole on one side of the pressure plate, and a second connecting rod is connected inside the threaded hole on the other side of the pressure plate. The outer diameter of the pressure plate is adapted to the inner diameter of the copper sleeve. The pressure plate passes through the copper sleeve and the connecting plate, and the top of the pressure plate is bolted to the center of the bottom of the spring seat.

[0011] Preferably, both the first connecting rod and the second connecting rod are inserted into the pressure plate through threaded holes, and the locking nut is sleeved on the outside of the threaded hole to form a threaded connection. The end of the first connecting rod away from the pressure plate is connected to the displacement sensor assembly, and the end of the second connecting rod away from the pressure plate is connected to the limit switch assembly.

[0012] Preferably, the spring is installed inside the housing, the bottom of the spring is connected to the spring seat, and the spring seat is slidably connected to the side wall of the housing via a bearing.

[0013] Compared with the prior art, the beneficial effects of the present invention are: This safer main steam valve actuator, through the setting of a piston rod and a test piston, allows the piston rod to overcome the spring's compression force and move upward under the action of the pressure oil in the rod chamber of the hydraulic cylinder, reaching the limit position after contact with the test piston, thus fully opening the valve. During unit operation, to prevent the valve rod of the quick-closing valve from jamming due to surface rust or impurities, pressure oil with the same pressure as the rod chamber of the hydraulic cylinder is introduced to the rear end of the test piston during operation. Under the combined force of the test piston and the spring, the piston rod moves in the valve closing direction and stops at the step limit position of the hydraulic cylinder. Then, the pressure oil at the rear end of the test piston is returned to the oil. At this time, the piston rod, under the action of the pressure oil in the rod chamber of the hydraulic cylinder, overcomes the spring's compression force and moves in the opening direction, pushing the test piston against the conversion plate assembly through the pressure oil, realizing the mobility test function. This can effectively solve the safety hazards and significant quality losses caused by non-stop production during online testing due to limit switch, proximity switch, displacement sensor signal problems, wiring or jamming problems during unit operation.

[0014] This safer main steam valve actuator, by incorporating a displacement sensor assembly and a limit switch assembly, achieves both mechanical and electronic redundancy protection for valve activity testing, based on the mechanical limit setting already implemented in the activity test. This is achieved through electronic signal feedback from the displacement sensor assembly and the limit switch assembly, and also provides feedback on the actuator's on / off position.

[0015] This safer main steam valve actuator, by incorporating a hydraulic cylinder with a built-in spring, effectively shortens the equipment height, reduces its weight, and increases its applicability to working conditions with limited space. Furthermore, by designing the hydraulic cylinder as a single unit, it reduces the number of components such as the upper and lower end caps, threaded rods, and nuts compared to traditional high-pressure anti-wear hydraulic actuators and high-pressure anti-oil hydraulic actuators, thus reducing leakage points and significantly saving costs. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the front cross-section structure of the present invention; Figure 2 This is a schematic diagram of the displacement sensor assembly structure of the present invention; Figure 3 This is a schematic diagram of the limit switch assembly structure of the present invention; Figure 4 This is a top view of the structure of the present invention; Figure 5 For the present invention Figure 1 Enlarged schematic diagram of section B in the middle.

[0017] In the diagram: 1. Hydraulic control block assembly; 2. Conversion plate assembly; 3. Bolt; 4. Hydraulic cylinder; 5. Housing; 6. Spring; 7. First Glyd ring; 8. Guide sleeve; 9. Spring seat; 10. Copper sleeve; 11. Connecting plate; 12. Pressure plate; 13. Locking nut; 14. First connecting rod; 15. Coupling; 16. Second Glyd ring; 17. Second guide belt; 18. Test piston; 19. First guide belt; 20. Piston rod; 21. Base plate; 22. Bearing; 23. Fixing plate; 24. Fixing nut; 25. Adjusting screw; 26. Second connecting rod; 27. Mounting nut; 28. Washer; 29. ​​Round nut; 30. Displacement sensor assembly; 31. Limit switch assembly; 32. Electrical junction box assembly. Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" 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 an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] like Figures 1 to 5As shown, the safer main steam valve actuator in this embodiment includes a hydraulic control block assembly 1, a conversion plate assembly 2 installed at the bottom of the hydraulic control block assembly 1, and a cylinder 4 installed at the bottom of the conversion plate assembly 2. The cylinder 4 is designed as a single unit, reducing the number of related components such as the upper end cover, lower end cover, threaded rod, and nut, thus reducing leakage points and significantly saving costs. A housing 5 is provided at the bottom of the cylinder 4. The housing 5 is a hollow cylinder. A bolt 3 is installed through the top edge of the housing 5 to connect the cylinder 4 and the housing 5. A connecting plate 11 is connected to the bottom of the housing 5, sealing the bottom of the housing 5. The connecting plate 11 is annular. A spring 6 is installed inside the housing 5. A spring seat 9 is connected to the bottom of the spring 6 inside the housing 5, supporting the spring 6. A bearing 22 is installed on the outer wall of the spring seat 9, and the bearing 22 rolls in the guide groove of the spring 6 chamber, providing guidance. A test piston is provided at the top of the inner cavity of the cylinder 4. 18. A piston rod 20 is installed at the bottom of the inner cavity of the oil cylinder 4. The piston rod 20 passes through the connecting plate 11 and the spring seat 9 and is inserted into the oil cylinder 4. A pressure plate 12 is sleeved on the outer side of the bottom end of the piston rod 20. A mounting nut 27 is sleeved on the bottom end of the piston rod 20 below the pressure plate 12. The mounting nut 27 supports and limits the pressure plate 12. A washer 28 is installed below the mounting nut 27. A round nut 29 is sleeved on the bottom of the piston rod 20. A coupling 15 is installed on the outer side of the round nut 29. The bottom end of the piston rod 20 is connected to a valve through the coupling 15. The valve is opened and closed by the piston rod 20, which is raised and lowered. When the piston rod 20 moves to the top of the cylinder 4, the valve opens, and when the piston rod 20 moves to the bottom, the valve closes. A displacement sensor assembly 30 is installed on one side of the housing 5, and a limit switch assembly 31 is installed on the other side of the housing 5. An electrical junction box assembly 32 is installed on the front wall of the housing 5. Through the electronic signal feedback of the displacement sensor assembly 30 and the limit switch assembly 31, electronic protection for valve activity testing can be realized, and the switching position of the actuator can also be fed back.

[0022] Specifically, a first Gladius ring 7 and a second Gladius ring 16 are respectively fitted on the top of the piston rod 20 and the outer wall of the test piston 18. The first Gladius ring 7 and the second Gladius ring 16 achieve the sealing of the piston rod 20, the test piston 18 and the inner wall of the cylinder 4. A first guide belt 19 and a second guide belt 17 are respectively provided above the first Gladius ring 7 and the second Gladius ring 16. The top of the piston rod 20 and the test piston 18 are slidably connected to the inner wall of the cylinder 4. The first guide belt 19 and the second guide belt 17 are used to guide the piston rod 20 and the test piston 18 to move up and down.

[0023] Furthermore, a base plate 21 is installed at the bottom of the cylinder 4, and a guide sleeve 8 is provided through the center of the base plate 21. Both the base plate 21 and the guide sleeve 8 are annular. The guide sleeve 8 is installed in the hole of the cylinder 4, and the piston rod 20 is inserted into the cylinder 4 through the base plate 21 and the guide sleeve 8. The guide sleeve 8 is used as a guide for the piston rod 20 to move up and down.

[0024] Furthermore, a copper sleeve 10 is movably inserted into the inner wall of the connecting plate 11. The connecting plate 11 is circular and is bolted to the bottom of the outer shell 5. A fixing plate 23 is provided at the bottom of the copper sleeve 10. A fixing nut 24 is provided at the bottom edge of the connecting plate 11 for locking the adjusting screw 25. An adjusting screw 25 is provided through the edge of the connecting plate 11. The fixing plate 23 is connected to the connecting plate 11 by screws. The upper surface of the fixing plate 23 contacts the bottom of the copper sleeve 10. The copper sleeve 10 is stably installed inside the connecting plate 11 by pressing the fixing plate 23 to the connecting plate 11.

[0025] Furthermore, the top of the adjusting screw 25 passes through the connecting plate 11 and contacts the bottom of the spring seat 9. The adjusting screw 25 passes through the fixing nut 24 and the connecting plate 11 in sequence. The adjusting screw 25 and the fixing nut 24 are threadedly connected. The adjusting screw 25 is installed through the connecting plate 11 to form a threaded connection. By adjusting the screw-in length of the adjusting screw 25, the top of the adjusting screw 25 can lift the spring seat 9, which can compress the spring 6 and facilitate the installation of the actuator. After the adjustment is completed, it is locked by the fixing nut 24.

[0026] Furthermore, threaded holes are provided on both sides of the pressure plate 12. The pressure plate 12 is a hollow cylinder. A locking nut 13 is fitted on the outside of the threaded hole to connect the pressure plate 12 with the first connecting rod 14 and the second connecting rod 26. The first connecting rod 14 is connected to the threaded hole on one side of the pressure plate 12, and the second connecting rod 26 is connected to the threaded hole on the other side of the pressure plate 12. The outer diameter of the pressure plate 12 is adapted to the inner diameter of the copper sleeve 10. The pressure plate 12 passes through the copper sleeve 10 and the connecting plate 11. The top of the pressure plate 12 is bolted to the center of the bottom of the spring seat 9. During the movement on the piston rod 20, the piston rod 20 drives the pressure plate 12 to move upward and pushes the spring seat 9 to move upward, so that the spring seat 9 compresses the spring 6.

[0027] Furthermore, both the first connecting rod 14 and the second connecting rod 26 are inserted into the pressure plate 12 through threaded holes, and the locking nut 13 is sleeved on the outside of the threaded hole to form a threaded connection. The end of the first connecting rod 14 away from the pressure plate 12 is connected to the displacement sensor assembly 30, and the end of the second connecting rod 26 away from the pressure plate 12 is connected to the limit switch assembly 31. Based on the mechanical limit of the already realized mobility test, this actuator can realize mechanical and electronic dual redundancy protection for valve mobility test through electronic signal feedback from the displacement sensor assembly 30 and the limit switch assembly 31. The connection between the first connecting rod 14, the second connecting rod 26 and the displacement sensor assembly 30 and the limit switch assembly 31 is designed as a flexible structure, which can compensate for the impact of equipment processing errors on the limit switch assembly 31 or the displacement sensor assembly 30, and effectively compensate for axial errors.

[0028] Furthermore, spring 6 is installed inside housing 5, and the bottom of spring 6 is connected to spring seat 9. Spring seat 9 is slidably connected to the side wall of housing 5 via bearing 22. Spring seat 9 is made of 20Cr13 material with nitrided surface, which not only has good rust prevention effect, but also the surface hardness meets the usage requirements. In addition, this part is welded, which can reduce processing and raw material costs. Compared with the traditional spring seat 9 material, which turns black after nitriding, it saves costs and has a better rust prevention effect. This actuator adopts the structure of spring 6 built into cylinder 4, which effectively shortens the height of the equipment, reduces the weight of the equipment, and increases the applicable working conditions with relatively small space.

[0029] The usage method of this embodiment is as follows: When the user is conducting an actuator activity test, firstly, during unit operation, the hydraulic control block assembly 1 drives pressurized oil through the internal pipeline into the rod chamber of the cylinder 4. The pressurized oil generates hydraulic pressure to squeeze the piston rod 20 within the cylinder 4, causing the piston rod 20 to move upward against the force of the spring 6 until it contacts the test piston 18 and reaches the limit, at which point the valve is fully open. To prevent the quick-closing valve stem from rust or impurities causing jamming, during unit operation, pressurized oil with the same pressure as the rod chamber of the cylinder 4 is supplied to the rear end of the test piston 18 through the hydraulic control block assembly 1. Since the diameter of the test piston 18 is larger than the piston rod 20, the pressure is controlled by the hydraulic control block assembly 1. At this point, the hydraulic pressure of the test piston 18 is greater. Under the combined force of the hydraulic pressure of the test piston 18 and the compression force of the spring 6, the piston rod 20 moves downward and stops at the step limit of the oil cylinder 4. Then, the pressure oil at the rear end of the test piston 18 is returned to the oil cylinder. At this time, under the action of the pressure oil in the rod chamber of the oil cylinder 4, the piston rod 20 overcomes the compression force of the spring 6 and moves upward. The hydraulic pressure of the pressure oil pushes the test piston 18 against the conversion plate assembly 2, and then the displacement is stopped at the limit. The mobility test ends. This can effectively solve the problem of non-stop production caused by limit switch, proximity switch, displacement sensor signal problems, circuit or card problems during the online test of the unit operation, which causes safety hazards and major quality losses.

[0030] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A safer main steam valve actuator, comprising a hydraulic control block assembly (1), a conversion plate assembly (2) mounted at the bottom of the hydraulic control block assembly (1), and a cylinder (4) mounted at the bottom of the conversion plate assembly (2), characterized in that: The bottom of the cylinder (4) is provided with a housing (5), and a bolt (3) is provided through the top edge of the cylinder (4) and the housing (5). A connecting plate (11) is connected to the bottom of the housing (5). A spring (6) is provided inside the housing (5). A spring seat (9) is connected to the bottom of the spring (6) inside the housing (5). A bearing (22) is installed on the outer side wall of the spring seat (9). A test piston (18) is provided at the top of the inner cavity of the cylinder (4). A piston rod (20) is provided at the bottom of the inner cavity of the cylinder (4). A pressure plate (12) is fitted on the outer side of the bottom end of the piston rod (20). A mounting nut (27) is fitted on the bottom end of the piston rod (20) below the pressure plate (12). A washer (28) is provided below the mounting nut (27). A round nut (29) is fitted on the bottom of the piston rod (20). A coupling (15) is installed on the outer side of the round nut (29). A displacement sensor assembly (30) is installed on one side of the housing (5). A limit switch assembly (31) is installed on the other side of the housing (5). An electrical junction box assembly (32) is installed on the front side wall of the housing (5).

2. The safer main steam valve actuator according to claim 1, characterized in that: The top of the piston rod (20) and the outer wall of the test piston (18) are respectively fitted with a first glyph (7) and a second glyph (16). A first guide belt (19) and a second guide belt (17) are respectively provided above the first glyph (7) and the second glyph (16). The top of the piston rod (20) and the test piston (18) are slidably connected to the inner wall of the oil cylinder (4).

3. The safer main steam valve actuator according to claim 1, characterized in that: The bottom of the cylinder (4) is equipped with a base plate (21), and a guide sleeve (8) is provided through the center of the base plate (21). Both the base plate (21) and the guide sleeve (8) are annular. The piston rod (20) passes through the base plate (21) and the guide sleeve (8) and is inserted into the cylinder (4).

4. The safer main steam valve actuator according to claim 1, characterized in that: A copper sleeve (10) is movably inserted into the inner wall of the connecting plate (11). A fixing plate (23) is provided at the bottom of the copper sleeve (10). A fixing nut (24) is provided at the bottom edge of the connecting plate (11). An adjusting screw (25) is provided through the edge of the connecting plate (11). The fixing plate (23) is connected to the connecting plate (11) by screws. The upper surface of the fixing plate (23) is in contact with the bottom of the copper sleeve (10).

5. The safer main steam valve actuator according to claim 4, characterized in that: The top of the adjusting screw (25) passes through the connecting plate (11) and contacts the bottom of the spring seat (9). The adjusting screw (25) passes through the fixing nut (24) and the connecting plate (11) in sequence. The adjusting screw (25) and the fixing nut (24) are threaded together.

6. The safer main steam valve actuator according to claim 1, characterized in that: The pressure plate (12) has threaded holes on both sides, and a locking nut (13) is fitted on the outside of the threaded hole. A first connecting rod (14) is connected inside the threaded hole on one side of the pressure plate (12), and a second connecting rod (26) is connected inside the threaded hole on the other side of the pressure plate (12). The outer diameter of the pressure plate (12) is matched with the inner diameter of the copper sleeve (10). The pressure plate (12) passes through the copper sleeve (10) and the connecting plate (11). The top of the pressure plate (12) is bolted to the center of the bottom of the spring seat (9).

7. The safer main steam valve actuator according to claim 6, characterized in that: The first connecting rod (14) and the second connecting rod (26) are both inserted into the pressure plate (12) through threaded holes. The locking nut (13) is sleeved on the outside of the threaded hole to form a threaded connection. The end of the first connecting rod (14) away from the pressure plate (12) is connected to the displacement sensor assembly (30), and the end of the second connecting rod (26) away from the pressure plate (12) is connected to the limit switch assembly (31).

8. The safer main steam valve actuator according to claim 1, characterized in that: The spring seat (9) is slidably connected to the side wall of the outer casing (5) via a bearing (22).

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