Manual and hydraulic main steam valve

Abstract

The invention discloses a manual and hydraulic main steam valve, which relates to the technical field of main steam valves and comprises a valve casing, a steam cavity is arranged in the valve casing, a valve cover is mounted at the upper end of the valve casing, supports are symmetrically mounted on two sides of the upper end of the valve cover, an oil cylinder is mounted at the upper ends of the two supports, a piston is movably mounted in the oil cylinder, and a radial through hole is formed in the piston. A top cover is installed at the upper end of the oil cylinder, a fixing nut is installed at the upper end of the top cover through an installation hole, a screw is installed in the fixing nut in a penetrating type threaded mode, and a butterfly valve is rotatably installed at the position, located in the oil cylinder, of the lower end of the screw. The lower end of the valve rod extends into the steam cavity and is provided with a valve disc, and one side of the surface of the oil cylinder is provided with a quick-closing device. The radial through hole is formed in the oil cylinder, and hydraulic oil is bidirectionally discharged through the radial through hole and the oil cavity below the piston, so that the fast closing speed is effectively increased, the maintenance cost is reduced, and starting oil ways and test oil ways are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of main steam valves, in particular to a manual and hydraulic main steam valve. Background Art

[0002] The main steam valve allows main steam to enter the steam turbine and can be quickly closed. It serves as a protective mechanism during critical turbine operation. Its tightness and flexibility directly impact the safe operation of the turbine generator. The main steam valve is typically driven by a hydraulic actuator, which is responsible for opening the main steam valve. Steam turbines are generally required to operate continuously for at least 8,000 hours. The main steam valve is normally open during turbine operation. Furthermore, the main steam valve must close within 0.3 seconds in the event of a unit trip, instantly cutting off steam flow to the turbine.

[0003] The existing main steam valve has a complex structure, is difficult to manufacture, and has high maintenance costs. The traditional main steam valve actuator is typically a Siemens structure. The opening process of the main steam valve actuator is complicated. It is necessary to first establish starting oil. After the starting oil pressure closes the piston in the closing direction, the quick-closing oil pressure is established. After the quick-closing oil pressure is established, the starting oil pressure is slowly released. Only then can the main steam valve be opened under the pressure difference between the quick-closing oil and the starting oil. The entire main steam valve opening process requires providing one quick-closing oil pressure, one starting oil pressure, and an external oil circuit for the activity test and return oil of the quick-closing valve.

[0004] At present, the traditional main steam valve quick closing relies on complex oil circuits. The entire main steam valve opening process requires the provision of one quick-closing oil pressure and one starting oil pressure. In addition, the activity test and return oil of the quick-closing valve each require an external oil circuit; at the same time, the traditional activity test is driven by a test piston and requires external hydraulic system control, which has a complex structure; at the same time, the traditional main steam valve is only equipped with a travel switch for position monitoring, and the valve stem position error is large, which cannot achieve accurate monitoring; at the same time, the traditional main steam valve can only stay in the two switch positions and cannot be controlled according to the actual flow butterfly valve opening. Summary of the Invention

[0005] The object of the present invention is to provide a manual and hydraulic main steam valve to solve the problems raised in the above background technology.

[0006] The cam is provided with an oil pump, and an oil pump is installed in the cam, and an oil pump is installed in the cam, and an oil pump is installed in the cam.

[0007] Preferably, a handwheel is installed at the upper end of the screw, a mounting groove is provided at the top end of the cylinder, an elastic spring is installed inside the mounting groove, the upper end of the piston is connected to the lower end of the elastic spring, a piston seal is installed on the surface of the piston, and the piston seal is in contact with the inner wall of the cylinder.

[0008] Preferably, a thrust ball bearing is installed at the lower end of the screw, and the butterfly valve is rotatably installed on the thrust ball bearing.

[0009] Preferably, a valve seat is installed inside the steam chamber below the valve disc, and the valve seat and the valve disc can form a seal.

[0010] Preferably, an L-shaped oil chamber is arranged at the bottom end of the oil cylinder, the quick-closing device is installed at one end of the oil cylinder, the L-shaped oil chamber and the quick-closing device are communicated, an oil inlet connecting pipe and an oil return pipe are respectively installed at one end of the quick-closing device, and an unloading valve is integrated on the quick-closing device.

[0011] Preferably, the connecting rod passes through the oil cylinder through mounting hole one, a sealing assembly is installed inside the mounting hole one, an oil baffle plate is installed at the lower end of the connecting rod, a connecting ring is installed at the upper end of the valve stem, the connecting ring and the oil baffle plate are connected by bolts, the valve stem passes through the valve housing through mounting hole two, a bushing is installed inside the mounting hole two and outside the valve stem, and a flexible graphite ring is installed on the surface of the valve stem above the bushing.

[0012] Preferably, a leakage oil channel is provided on the surface of the oil cylinder on one side of the sealing assembly, and a leakage detection tube is installed at one end of the leakage oil channel.

[0013] Preferably, the position detection assembly includes a mounting plate, a moving rod, a pointer, a proximity switch and a scale plate. The front and rear parts of the upper end of the valve cover between the brackets are both installed with mounting plates. The moving rod is installed on the surface of the oil baffle plate. A guide groove is arranged on the surface of one of the mounting plates. One end of the moving rod passes through the guide groove and is installed with a pointer. A scale plate is installed on the surface of the mounting plate on one side of the guide groove. A proximity switch is installed on one end of the other mounting plate on the side of the oil baffle plate.

[0014] Compared with the prior art, the present invention has the following beneficial effects: This manual and hydraulic main steam valve has radial through holes on the oil cylinder. When the main steam valve is quickly closed, the hydraulic oil is unloaded in both directions through the radial through holes and the oil chamber below the piston, thereby effectively improving the quick closing speed, reducing maintenance costs, reducing the starting oil circuit and test oil circuit, and at the same time reducing the return oil pipeline, simplifying the control module, and controlling the quick closing of the main steam valve with only one solenoid valve.

[0015] This manual and hydraulic main steam valve drives the screw by rotating the handwheel. When the screw rotates, it can push the piston to move a certain stroke. The activity test can be completed by rotating the handwheel to the original position. No external hydraulic system control is required and the structure is simple.

[0016] This manual and hydraulic main steam valve is equipped with an opening and closing proximity switch and a scale plate. When the butterfly valve moves, the proximity switch can detect the position of the butterfly valve. At the same time, when the butterfly valve moves, the oil baffle plate drives the pointer on the moving rod to move on the scale plate surface, thereby forming a double monitoring of the position of the butterfly valve, thereby improving the accuracy of the switch position and the observability of the position.

[0017] This manual and hydraulic main steam valve can adjust the maximum opening and closing degree of the butterfly valve according to the actual flow rate, which is suitable for the needs of more occasions and makes it easy for the butterfly valve to stay in various positions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a schematic diagram of the rear structure of the present invention; Figure 3 It is a front cross-sectional view of the present invention; Figure 4 It is a structural schematic diagram of the mounting plate of the present invention; Figure 5 For the present invention Figure 3 Enlarged view of point A in the middle; Figure 6 It is a cross-sectional view of the position detection component of the present invention.

[0019] In the figure: 1. valve housing; 2. steam chamber; 3. valve cover; 4. bracket; 5. oil cylinder; 6. piston; 7. top cover; 8. fixing nut; 9. screw; 10. butterfly valve; 11. connecting rod; 12. valve stem; 13. valve disc; 14. quick closing device; 15. oil return pipe 1; 16. position detection assembly; 17. handwheel; 18. mounting groove; 19. elastic spring; 20. piston seal; 21. thrust ball bearing; 22. valve seat; 23. L-shaped oil chamber; 24. leakage detection tube; 25. oil inlet connecting pipe; 26. oil return pipe 2; 27. sealing assembly; 28. oil baffle plate; 29. ​​connecting ring; 30. leakage oil channel; 31. bushing; 32. flexible graphite ring; 1601. mounting plate; 1602. moving rod; 1603. pointer; 1604. proximity switch; 1605. scale plate. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0021] In the description of the invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end" and other terms indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the invention. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] like Figures 1 to 6As shown, the manual and hydraulic main steam valve of this embodiment includes a valve housing 1, which is the outer shell of the main steam valve, and the two pieces of the valve housing 1 are provided with flanges for easy connection with the steam pipe. A steam chamber 2 is provided inside the valve housing 1, and the steam chamber 2 is used for steam to pass through. A valve cover 3 is installed on the upper end of the valve housing 1 through a flange, and brackets 4 are symmetrically installed on both sides of the upper end of the valve cover 3. An oil cylinder 5 is installed on the upper ends of the two brackets 4. A piston 6 is movably installed inside the oil cylinder 5, and a radial through hole is provided on the piston 6. When the oil is quickly closed, the hydraulic oil returns to the inside of the chamber where the elastic spring 19 is located through the radial through hole to achieve two-way pressure relief. A top cover 7 is installed on the upper end of the oil cylinder 5 through a flange, and a fixing nut 8 is installed on the upper end of the top cover 7 through a mounting hole. A screw 9 is installed with a through-thread inside the fixing nut 8, and a butterfly valve 10 is rotatably installed at the lower end of the screw 9 and located inside the oil cylinder 5. By rotating the screw 9, the screw 9 can drive The butterfly valve 10 moves inside the oil cylinder 5, and a connecting rod 11 is installed at the lower end of the piston 6. The lower end of the connecting rod 11 passes through the oil cylinder 5 and is installed with a valve stem 12. The lower end of the valve stem 12 extends into the steam chamber 2 and is installed with a valve disc 13. The valve disc 13, the valve stem 12 and the piston 6 are connected. When the piston 6 rises, the valve disc 13 rises accordingly, and vice versa. A quick-closing device 14 is installed on one side of the surface of the oil cylinder 5. The quick-closing device 14 is used to control the valve to close quickly. The setting of the quick-closing device 14 reduces the starting oil circuit and the test oil circuit, and at the same time reduces the return oil pipeline and simplifies the control module. Only one solenoid valve can control the quick closing of the main steam valve. A return oil pipe 15 is installed on the surface of the oil cylinder 5 above the piston 6, and a position detection component 16 is installed between the two brackets 4. The position detection component 16 is used to detect the movement distance of the valve disc 13 for detection, thereby improving the accuracy of the switch position and the observability of the position.

[0023] Specifically, a handwheel 17 is installed at the upper end of the screw 9. The setting of the handwheel 17 facilitates the direct rotation of the screw 9 without the use of tools, and when it cannot be closed normally, it can be forced to close by turning the handwheel 17. A mounting groove 18 is arranged at the top end of the oil cylinder 5, and an elastic spring 19 is installed inside the mounting groove 18. The upper end of the piston 6 is connected to the lower end of the elastic spring 19. The elastic force generated by the elastic spring 19 supports the piston 6, providing a downward thrust for the piston 6, so that the piston 6 drives the valve disc 13 and the valve seat 22 to maintain sealing, thereby cutting off the steam chamber 2. A piston seal 20 is installed on the surface of the piston 6, and the piston seal 20 contacts the inner wall of the oil cylinder 5. The piston seal 20 is used to ensure the sealing when the piston 6 moves up and down. The piston seal 20 can divide the interior of the oil cylinder 5 into two upper and lower oil chambers.

[0024] Furthermore, a thrust ball bearing 21 is installed at the lower end of the screw 9, and the butterfly valve 10 is rotatably installed on the thrust ball bearing 21. The butterfly valve 10 can rotate under the action of the thrust ball bearing 21, effectively preventing the butterfly valve 10 from rotating with the screw 9.

[0025] Furthermore, a valve seat 22 is installed inside the steam chamber 2 below the valve disc 13. The valve seat 22 and the valve disc 13 can form a seal. When the valve disc 13 and the valve seat 22 are combined, the steam inside the steam chamber 2 exerts a certain pressure on the valve disc 13 from above, effectively preventing the valve disc 13 and the valve seat 22 from accidentally separating.

[0026] Furthermore, an L-shaped oil chamber 23 is arranged at the bottom end of the oil cylinder 5, and the quick-closing device 14 is installed at one end of the oil cylinder 5. The L-shaped oil chamber 23 and the quick-closing device 14 are connected. An oil inlet connecting pipe 25 and an oil return pipe 26 are respectively installed at one end of the quick-closing device 14. An unloading valve is integrated on the quick-closing device 14. The hydraulic oil enters the quick-closing device 14 through the oil inlet connecting pipe 25 and enters the oil chamber below the piston 6 through the L-shaped oil chamber 23. The hydraulic oil pushes the piston 6 to move upward, and the piston 6 drives the valve disc 13 to rise, so that the interior of the steam chamber 2 is connected, and the unloading valve is opened by the solenoid valve. Remote control is performed. When the quick-closing device 14 needs to control the valve disc 13 for quick closing, the unloading valve is opened under the action of the internal spring to return the hydraulic oil to the chamber below the piston 6. When the pressure inside the chamber is less than the elastic force of the elastic spring 19, the elastic spring 19 will drive the piston 6 to move toward the closed state of the main steam valve. The radial through holes provided on the piston 6 allow the hydraulic oil to enter the spring chamber above the piston 6 through the radial through holes for two-way pressure relief, thereby realizing rapid closing of the main steam valve. At the same time, the return oil management design can be minimized, which can reduce the cost of laying pipelines on site for users.

[0027] Furthermore, the connecting rod 11 extends through the oil cylinder 5 through mounting hole 1. A sealing assembly 27 is installed within mounting hole 1, ensuring a tight seal during the vertical movement of the connecting rod 11. An oil deflector 28 is mounted at the lower end of the connecting rod 11, and a connecting ring 29 is mounted at the upper end of the valve stem 12. The connecting ring 29 and oil deflector 28 are bolted together. The valve stem 12 extends through mounting hole 2, extending through the valve housing 1. The connecting rod 11 and valve stem 12 are connected by the oil deflector 28 and connecting ring 29, enabling their joint movement. A bushing 31 is installed within mounting hole 2 and on the exterior of the valve stem 12. A flexible graphite ring 32 is mounted on the surface of the valve stem 12 above the bushing 31. The flexible graphite ring 32 operates stably over a wide temperature range of -200°C to 850°C, resisting softening at high temperatures and cracking at low temperatures. It is also resistant to strong acids and bases within a pH range of 0-14. The flexible graphite ring 32 also exhibits self-lubrication and compression-rebound properties.

[0028] Furthermore, a leakage oil channel 30 is provided on the surface of the oil cylinder 5 on one side of the sealing component 27, and a leakage detection tube 24 is installed at one end of the leakage oil channel 30. When the sealing component 27 cannot complete the sealing, the hydraulic oil will leak, and the leaked hydraulic oil will enter the leakage oil channel 30 and enter the leakage detection tube 24 from the leakage oil channel 30, making it easier to understand whether the sealing component 27 can effectively seal.

[0029] Furthermore, the position detection assembly 16 includes a mounting plate 1601, a moving rod 1602, a pointer 1603, a proximity switch 1604 and a scale plate 1605. The front and rear ends of the upper end of the valve cover 3 between the brackets 4 are both mounted with mounting plates 1601. The moving rod 1602 is mounted on the surface of the oil baffle plate 28. A guide groove is arranged on the surface of one mounting plate 1601. One end of the moving rod 1602 passes through the guide groove and is mounted with a pointer 1603. A scale plate 1605 is mounted on the surface of the mounting plate 1601 on one side of the guide groove. Another mounting plate on the side of the oil baffle plate 28 A proximity switch 1604 is installed at one end of 1601. The model of the proximity switch 1604 is an inductive opening and closing proximity switch. The proximity switch 1604 can detect the position of the oil baffle plate 28. At the same time, the movement of the oil baffle plate 28 drives the moving rod 1602 to move inside the guide groove, and the moving rod 1602 drives the pointer 1603 to move on the surface of the scale plate 1605. By setting the opening and closing proximity switch 1604 and the scale plate 1605, the movement position of the valve disc 13 is double-monitored, which improves the accuracy of the switch position and the observability of the position.

[0030] The method of using this embodiment is as follows: first, turn the hand wheel 17 to drive the screw 9 to rotate, and the screw 9 drives the butterfly valve 10 to move down and seal with the piston 6, and then the pressure oil enters the oil chamber below the piston 6 through the quick closing device 14. The hydraulic oil generates a certain pressure on the piston 6, so that the piston 6 presses the butterfly valve 10, and then reversely turn the hand wheel 17. The hydraulic oil will push the piston 6 to overcome the force of the elastic spring 19 and move upward. The piston 6 drives the valve disc 13 to open through the connecting rod 11, the oil baffle plate 28, the connecting ring 29 and the valve stem 12, so that the steam The inside of cavity 2 is connected. When the unit is running, in order to prevent the main steam valve stem 12 from rusting or sticking due to impurities, the activity test of the valve stem 12 is usually performed regularly. The process is: turn the handwheel 17 to move the piston 6 to the closing direction. When the displacement of the piston 6 in the closing direction reaches 15mm, turn the handwheel 17 in the opposite direction to make the piston 6 drive the valve disc 13 to the opening direction again until it is fully opened. The test is completed, and an open and close proximity switch 1604 is set to detect the position of the valve disc 13. At the same time, the valve disc 13 drives the oil baffle 28 when it moves. The moving rod 1602 on the moving rod 1602 moves, and the pointer 1603 on the moving rod 1602 moves on the scale plate 1605, which is convenient for monitoring the position of the valve disc 13. When the main steam valve needs to be unloaded and closed, the pressure at the oil inlet connecting pipe 25 drops, and the unloading valve on the quick closing device 14 opens under the action of the internal spring, returning the hydraulic oil inside the oil chamber below the piston 6. When the pressure inside the oil chamber below the piston 6 is less than the pressure of the elastic spring 19, the elastic spring 19 will drive the piston 6 to move toward the closing direction of the main steam valve. The piston 6 is provided with a radial through hole, and the hydraulic oil in the lower chamber of the piston 6 enters the chamber where the elastic spring 19 is located through the radial through hole for oil return, which can realize the rapid closing of the main steam valve. At the same time, the return oil pipeline can be designed to be small, reducing the cost of laying pipelines on site. The quick-closing device 14 can be controlled by a solenoid valve installed on the hydraulic pipeline, which can realize the rapid closing of the main steam valve, reducing the use of the quick-closing control device to control the starting oil, quick-closing oil, and test oil, saving a lot of pipelines. The main steam valve has a small number of parts and is easy to maintain.

[0031] Finally, it should be noted that the foregoing descriptions are merely preferred embodiments of the invention and are not intended to limit the invention. Although the invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will be able to modify the technical solutions described in the foregoing embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the invention shall be included within the scope of protection of the invention.

Claims

1. A manual and hydraulic main steam valve, comprising a valve housing (1), characterized in that: A steam chamber (2) is provided inside the valve housing (1), a valve cover (3) is mounted on the upper end of the valve housing (1) via a flange, brackets (4) are symmetrically mounted on both sides of the upper end of the valve cover (3), an oil cylinder (5) is mounted on the upper ends of the two brackets (4), a piston (6) is movably mounted inside the oil cylinder (5), and a radial through hole is provided on the piston (6), a top cover (7) is mounted on the upper end of the oil cylinder (5) via a flange, a fixing nut (8) is mounted on the upper end of the top cover (7) via a mounting hole, and a screw ( 9), a butterfly valve (10) is rotatably installed at the lower end of the screw (9) and located inside the oil cylinder (5), a connecting rod (11) is installed at the lower end of the piston (6), the lower end of the connecting rod (11) passes through the oil cylinder (5) and is installed with a valve stem (12), the lower end of the valve stem (12) extends to the inside of the steam chamber (2) and is installed with a valve disc (13), a quick closing device (14) is installed on one side of the surface of the oil cylinder (5), a return oil pipe (15) is installed on the surface of the oil cylinder (5) above the piston (6), and a position detection component (16) is installed between the two brackets (4).

2. The manual and hydraulic main steam valve according to claim 1 is characterized in that: A hand wheel (17) is installed at the upper end of the screw rod (9), a mounting groove (18) is arranged at the top end of the inner portion of the oil cylinder (5), an elastic spring (19) is installed inside the mounting groove (18), the upper end of the piston (6) and the lower end of the elastic spring (19) are connected, a piston seal (20) is installed on the surface of the piston (6), and the piston seal (20) is in contact with the inner wall of the oil cylinder (5).

3. The manual and hydraulic main steam valve according to claim 1 is characterized in that: A thrust ball bearing (21) is installed at the lower end of the screw (9), and the butterfly valve (10) is rotatably installed on the thrust ball bearing (21).

4. The manual and hydraulic main steam valve according to claim 1 is characterized in that: A valve seat (22) is installed inside the steam chamber (2) below the valve disc (13), and the valve seat (22) and the valve disc (13) can form a seal.

5. The manual and hydraulic main steam valve according to claim 1 is characterized in that: An L-shaped oil chamber (23) is arranged at the bottom end of the oil cylinder (5), and the quick-closing device (14) is installed at one end of the oil cylinder (5). The L-shaped oil chamber (23) and the quick-closing device (14) are connected. An oil inlet connecting pipe (25) and a second oil return pipe (26) are respectively installed at one end of the quick-closing device (14), and an unloading valve is integrated on the quick-closing device (14).

6. The manual and hydraulic main steam valve according to claim 1, characterized in that: The connecting rod (11) passes through the oil cylinder (5) through the first mounting hole, a sealing assembly (27) is installed inside the first mounting hole, an oil baffle plate (28) is installed at the lower end of the connecting rod (11), a connecting ring (29) is installed at the upper end of the valve stem (12), the connecting ring (29) and the oil baffle plate (28) are connected by bolts, the valve stem (12) passes through the valve housing (1) through the second mounting hole, a bushing (31) is installed inside the second mounting hole and outside the valve stem (12), and a flexible graphite ring (32) is installed on the surface of the valve stem (12) above the bushing (31).

7. The manual and hydraulic main steam valve according to claim 6, characterized in that: A leakage oil passage (30) is provided on the surface of the oil cylinder (5) on one side of the sealing assembly (27), and a leakage detection tube (24) is installed at one end of the leakage oil passage (30).

8. The manual and hydraulic main steam valve according to claim 6, characterized in that: The position detection assembly (16) includes a mounting plate (1601), a moving rod (1602), a pointer (1603), a proximity switch (1604) and a scale plate (1605). The front and rear parts of the upper end of the valve cover (3) between the brackets (4) are both mounted with mounting plates (1601). The surface of the oil baffle plate (28) is mounted with a moving rod (1602). A guide groove is arranged on the surface of one of the mounting plates (1601). One end of the moving rod (1602) passes through the guide groove and is mounted with a pointer (1603). The surface of the mounting plate (1601) on one side of the guide groove is mounted with a scale plate (1605). The proximity switch (1604) is mounted on one end of another mounting plate (1601) on one side of the oil baffle plate (28).

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