A balanced sealing ring for high pressure bypass valve of 660MW steam turbine unit

Abstract

The invention discloses a balancing seal ring for a high-pressure bypass valve of a 660MW steam turbine unit, and relates to the technical field of balanced seals for bypass valves. In the prior art, the valve core balancing seal ring is pressed from graphite, and the graphite has good sealing performance, but its strength is low. If there are slight impurities in the steam pipeline, the valve core balancing seal ring is very likely to be torn to cause internal leakage, thereby resulting in poor sealing effect and easy damage to cause leakage. The invention optimizes the sealing performance and effectively reduces steam leakage by adjusting the spacing of the sealing rings. At the same time, the twisting deformation of the extension ring and the inner sleeve and the inclination of the support sheet can buffer and absorb impact, reduce the damage of the vibration to the system's own structure, and have a stable and reliable structure, can buffer and reduce shock and reduce noise, can avoid stress concentration, have good protection and limiting effects on internal components, and have many beneficial effects such as elastic compensation and the ability to adapt to spacing changes.

Description

Technical Field

[0001] The invention relates to the technical field of bypass valve balancing seal rings, in particular to a 660MW steam turbine unit high-pressure bypass valve balancing seal ring. Background Art

[0002] The high-pressure bypass valve is an essential and important equipment for reheat steam turbine units. It protects the boiler reheater from dry burning, speeds up the unit startup time, and improves the unit startup conditions. Before the turbine is started after the boiler is ignited, or when the turbine trips, the main steam is led to the reheat steam pipeline after temperature reduction and pressure reduction, so that the boiler reheater has a certain steam flow, thereby protecting the reheater from burning. In normal operation of the unit, the high-pressure bypass valve is required to be closed tightly, but internal leakage is common in actual production.

[0003] In this regard, the patent publication number CN117108817A discloses a new sealing structure and method for a high-pressure bypass valve, which solves the problem that the existing high-pressure bypass valve is not convenient to send out a prompt signal when the pressure is released during use, which reminds the patrol staff, affects the staff's diagnosis of the fault of the thermal power unit, and easily causes equipment overload or failure leading to accidents. The present invention can also disassemble and replace the sealing cover to avoid excessive wear of the sealing cover affecting the sealing performance.

[0004] In this regard, the patent with publication number CN215635330U discloses a sealing ring packing chamber of a high-temperature and high-pressure regulating valve. By adopting a combined sealing form of a spring energy storage sealing ring and a graphite packing ring, the problem of easy wear and leakage caused by only using packing seals in traditional regulating valves can be effectively avoided. At the same time, by arranging a pressurizing mechanism on the outside of the graphite packing ring, the sealing performance of the regulating valve is further improved.

[0005] Based on the above-mentioned comparative documents and the prior art, the valve core balance sealing ring is made of pressed graphite. Graphite has good sealing performance, but its strength is low. If there is a little impurity in the steam pipe, the valve core balance sealing ring is likely to be pulled and cause internal leakage, resulting in poor sealing effect and easy damage to cause leakage.

[0006] In view of the above problems, a balanced sealing ring for a high-pressure bypass valve of a 660MW steam turbine unit is proposed. Summary of the invention

[0007] The object of the present invention is to provide a balanced sealing ring for a high-pressure bypass valve of a 660MW steam turbine unit, which solves the problem of poor sealing effect in the background technology.

[0008] To achieve the above-mentioned object, the present invention provides the following technical solutions: a balanced sealing ring of a high-pressure bypass valve of a 660MW steam turbine unit, comprising an upper sealing ring, the bottom end of the upper sealing ring is connected to an extension ring, the bottom end of the extension ring is connected to a lower sealing ring, the upper surface of the upper sealing ring is connected to a nickel wire graphite ring, the outer surface of the upper sealing ring is connected to a side sleeve ring, the upper surface and the lower surface of the extension ring are connected to an elastic component, the elastic component comprises a gasket, the upper surface and the lower surface of the extension ring are both connected to the gasket, a fixing column is embedded in the gasket, and the fixing column is used to connect the upper sealing ring and the extension ring together;

[0009] The gasket has a reserved groove formed inside, a support sheet is embedded inside the reserved groove, a nylon mesh is connected to the surface of the support sheet, an inner sleeve is connected to the inner side of the support sheet, and a built-in cavity is formed inside the extension ring and the inner sleeve;

[0010] The bottom end of the upper sealing ring is connected with an extension component, and the extension component includes a top supporting block. The bottom surface of the upper sealing ring is connected with the top supporting block, and the top surface of the lower sealing ring is connected with the bottom supporting block. A movable pin is fixedly connected to the inside of the top supporting block, and a movable groove is opened inside the bottom supporting block, and the movable pin is embedded in the inside of the movable groove.

[0011] Preferably, a support assembly is embedded in the extension ring, the support assembly includes a connecting block, the connecting block is embedded in the extension ring, a support column is embedded in the extension ring, and the support column and the connecting block are connected together.

[0012] Preferably, an elastic sleeve is fixedly connected to the bottom end of the connecting block, and the elastic sleeve is arranged between two groups of extension rings, and the elastic sleeve is arranged in a U shape.

[0013] Preferably, the cavities opened inside the gasket, the extension ring and the elastic sleeve are connected, the connection between the gasket, the extension ring and the elastic sleeve is sealed, and air is stored in the internal cavity formed by the gasket, the extension ring and the elastic sleeve.

[0014] Preferably, an air pressure valve is embedded in the top end of the gasket, and air is transmitted to the inside of the gasket, the extension ring and the elastic sleeve by pushing the valve core of the air pressure valve.

[0015] Preferably, an elastic sheet is fixedly connected to the support column, the elastic sheet is arranged in an arc shape, air holes are opened on the elastic sheet, and the elastic sheet is tightly fitted on the inner wall of the extension ring.

[0016] Preferably, a notch is provided at the connection between the extension ring and the elastic sleeve, an extension belt is embedded in the notch, and an extension belt is connected to the connection between the elastic sleeve and the extension ring.

[0017] Preferably, the gasket, the extension ring and the inner sleeve form an integrated structure, and the outer wall of the extension ring and the inner wall of the inner sleeve are both corrugated.

[0018] Preferably, the support sheets are evenly distributed inside the reserved groove, and the support sheets are used to separate the reserved groove and the built-in cavity.

[0019] Preferably, one side surface of the support sheet is connected to the extension ring, and the other side surface of the support sheet close to the inner sleeve is connected to the inner sleeve.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. A balanced sealing ring for a high-pressure bypass valve of a 660MW steam turbine unit provided by the present invention optimizes sealing performance and effectively reduces steam leakage by adjusting the spacing of the sealing rings. At the same time, the distortion and deformation of the extension ring and the inner sleeve and the inclination of the support sheet can buffer and absorb impacts, reduce the damage of vibration to the system's own structure, and has a stable and reliable structure, can buffer and reduce shock and reduce noise, can avoid stress concentration, has good protection and limiting effects on internal components, and has many beneficial effects such as elastic compensation and the ability to adapt to spacing changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 It is a schematic diagram of the structure of the gasket and the fixing column of the present invention;

[0024] Figure 3 It is a schematic diagram of the structure of the support sheet and the nylon net of the present invention;

[0025] Figure 4 It is a schematic diagram of the structure of the support sheet and the bottom support block of the present invention;

[0026] Figure 5 It is a schematic diagram of the structure of the bottom supporting block and the top supporting block of the present invention in a retracted state;

[0027] Figure 6 It is a schematic diagram of the structure of the bottom supporting block and the top supporting block of the present invention in an unfolded state;

[0028] Figure 7 It is a schematic diagram of the exploded structure of the upper sealing ring and the lower sealing ring of the present invention;

[0029] Figure 8 It is a schematic diagram of the structure of the elastic sleeve and the connecting block of the present invention;

[0030] Fig. 9 For the present invention Figure 8 Schematic diagram of the structure at A in the middle.

[0031] In the figure: 11, upper sealing ring; 12, extension ring; 13, lower sealing ring; 14, nickel wire graphite ring; 15, side ring; 16, inner sleeve; 2, elastic component; 21, gasket; 22, fixing column; 23, reserved groove; 24, support sheet; 25, nylon mesh; 26, built-in cavity; 3, extension component; 31, bottom support block; 32, top support block; 33, movable groove; 34, movable pin; 4, support component; 41, air pressure valve; 42, elastic sleeve; 43, connecting block; 44, support column; 45, elastic sheet; 46, air hole; 47, extension belt. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0033] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the accompanying drawings.

[0034] Combination Figure 1-Figure 9 The invention discloses a 660MW steam turbine high-pressure bypass valve balanced sealing ring, comprising an upper sealing ring 11, an extension ring 12 connected to the bottom end of the upper sealing ring 11, a lower sealing ring 13 connected to the bottom end of the extension ring 12, a nickel wire graphite ring 14 connected to the upper surface of the upper sealing ring 11, a side sleeve ring 15 connected to the outer surface of the upper sealing ring 11, an elastic component 2 connected to the upper and lower surfaces of the extension ring 12, the elastic component 2 comprising a gasket 21, and the upper and lower surfaces of the extension ring 12. The upper sealing ring 11 and the lower sealing ring 13 are connected with a gasket 21, and a fixing column 22 is embedded in the gasket 21. The fixing column 22 is used to connect the upper sealing ring 11 and the extension ring 12 together. The gasket 21, the extension ring 12 and the inner bushing 16 form an integrated structure. The outer wall of the extension ring 12 and the inner wall of the inner bushing 16 are both corrugated. The upper sealing ring 11 and the lower sealing ring 13 are provided with a nickel wire graphite ring 14. The nickel wire graphite ring 14 is a ring structure formed by weaving and crossing, which enhances the strength and erosion resistance of the sealing ring;

[0035] In order to improve the overall sealing performance, side rings 15 are provided on both the upper sealing ring 11 and the lower sealing ring 13. The side rings 15 can improve the fit after contact, which also makes the sealing effect of the sealing ring more excellent.

[0036] When the spacing of the sealing ring thickness is adjusted, the extension ring 12 and the inner sleeve 16 are both made of ductile materials. By accurately adjusting the spacing of the sealing ring thickness, the sealing ring can be more closely matched with the valve stem and the valve body, and the possible gap can be effectively filled, thereby significantly reducing the possibility of steam leakage, improving the sealing and safety of the system, and also avoiding excessive or insufficient local pressure, thereby reducing wear;

[0037] To adjust the spacing of the sealing ring, the specific operations are as follows:

[0038] A reserved groove 23 is provided inside the gasket 21, a support sheet 24 is embedded inside the reserved groove 23, a nylon mesh 25 is connected to the surface of the support sheet 24, an inner sleeve 16 is connected to the inner side of the support sheet 24, a built-in cavity 26 is provided inside the extension ring 12 and the inner sleeve 16, the support sheet 24 is evenly distributed inside the reserved groove 23, the support sheet 24 is used to separate the reserved groove 23 and the built-in cavity 26, one side of the support sheet 24 is connected to the extension ring 12, and the other side of the support sheet 24 close to the inner sleeve 16 is connected to the inner sleeve 16, and a nylon mesh 25 is connected to the surface of the support sheet 24, which can protect the support sheet 24 and prevent the support sheet 24 from breaking when it is subjected to large stress or frequent deformation. In particular, during the adjustment of the sealing ring spacing, the support sheet 24 will deform to a certain extent, and the nylon mesh 25 can limit the deformation range of the support sheet 24, so that it deforms within a controllable range, ensuring the long-term reliability of the support sheet 24.

[0039] The support sheets 24 are evenly distributed inside the reserved groove 23 and separate the reserved groove 23 and the built-in cavity 26. This separation design can ensure that the reserved groove 23 and the built-in cavity 26 maintain their respective functional characteristics under different working conditions. When the sealing ring is subjected to external pressure changes, this separation can prevent mutual interference between different cavities, maintain the pressure balance in each cavity, and thus ensure the stable operation of the entire sealing ring.

[0040] The bottom end of the upper sealing ring 11 is connected to an extension component 3, and the extension component 3 includes a top supporting block 32. The bottom surface of the upper sealing ring 11 is connected to the top supporting block 32, and the top surface of the lower sealing ring 13 is connected to the bottom supporting block 31. The interior of the top supporting block 32 is fixedly connected to a movable pin 34, and the interior of the bottom supporting block 31 is provided with a movable groove 33, and the movable pin 34 is embedded in the interior of the movable groove 33.

[0041] When adjusting the spacing, the upper sealing ring 11 and the lower sealing ring 13 are manually moved, and the upper sealing ring 11 is rotated. When the upper sealing ring 11 rotates, the top supporting block 32 is driven to rotate. When the top supporting block 32 rotates, the movable pin 34 is driven. When the movable pin 34 on the top supporting block 32 slides along the movable groove 33 provided inside the bottom supporting block 31, due to the setting of the inclined surface, when sliding, the movable pin 34 slides upward along the movable groove 33, so that the spacing between the top supporting block 32 and the bottom supporting block 31 is gradually changed. When the spacing between the bottom supporting block 31 and the top supporting block 32 is changed, the spacing of the sealing rings is also adjusted.

[0042] When the relative position between the upper sealing ring 11 and the lower sealing ring 13 is changed, the rotation of the upper sealing ring 11 drives the gasket 21. At this time, the extension ring 12 and the inner sleeve 16 connected between the gasket 21 will be twisted and deformed. When the extension ring 12 and the inner sleeve 16 are twisted and deformed, the support sheet 24 is also twisted. When the support sheet 24 is twisted, it will be tilted and set on the inner side of the gasket 21. During this period, the support sheet 24 will be stretched. In order to prevent the support sheet 24 from breaking during the stretching process, a nylon mesh 25 is wrapped on the outer surface of the support sheet 24 to limit the deformation range of the support sheet 24, so that the deformation of the support sheet 24 is within a controllable range. When the deformation of the support sheet 24 is limited, the twisting deformation of the extension ring 12 and the inner sleeve 16 can also be limited. Therefore, the nylon mesh 25 can not only protect the support sheet 24, but also provide a limit for the torsion between the upper sealing ring 11 and the lower sealing ring 13, thereby avoiding excessive twisting of the extension ring 12 and the inner sleeve 16.

[0043] The twisting deformation of the extension ring 12 and the inner sleeve 16 and the inclination of the support sheet 24 can buffer and absorb impact, improve the stability and reliability of the system, and also absorb and dissipate noise to a certain extent through such twisting deformation, improve the working environment, and reduce the damage of vibration to its own structure.

[0044] After the upper sealing ring 11 and the lower sealing ring 13 are twisted, the extension ring 12 and the inner sleeve 16 are twisted, and the extension ring 12 and the inner sleeve 16 are longitudinally stretched. The specific operation is as follows:

[0045] The extension ring 12 is embedded with a support assembly 4, and the support assembly 4 includes a connecting block 43, and the extension ring 12 is embedded with a connecting block 43, and the extension ring 12 is embedded with a support column 44, and the support column 44 and the connecting block 43 are connected together. The bottom end of the connecting block 43 is fixedly connected with an elastic sleeve 42, and the elastic sleeve 42 is arranged between the two groups of extension rings 12. The elastic sleeve 42 is arranged in a U shape, and the cavities opened inside the gasket 21, the extension ring 12 and the elastic sleeve 42 are connected, and the connection between the gasket 21, the extension ring 12 and the elastic sleeve 42 is sealed, and air is stored in the internal cavity composed of the gasket 21, the extension ring 12 and the elastic sleeve 42. The top of the gasket 21 is embedded with an air pressure valve 41, and the air is transmitted to the inside of the gasket 21, the extension ring 12 and the elastic sleeve 42 by pushing the valve core of the air pressure valve 41;

[0046] By providing an air pressure valve 41, in the high-pressure bypass valve, high-pressure gas is transported to the interior of the extension ring 12 through the air pressure valve 41. At this time, the air fills the interior of the extension ring 12, causing the extension ring 12 to expand. At this time, the gas enters through the air hole 46, thereby causing the extension ring 12 to expand and increase the degree of fit.

[0047] When the distance between the upper sealing ring 11 and the lower sealing ring 13 is enlarged, the upper sealing ring 11 moves upward and drives the gasket 21. When the gasket 21 is pulled and stretched, in order to adapt to this movement process, the gasket 21 drives the elastic sleeve 42 to stretch. When the gasket 21 drives the elastic sleeve 42 to expand continuously, the length of the extension ring 12 and the inner sleeve 16 is driven. The inner sleeve 16 itself is made of rubber material and has a certain ductility. The extension of the extension ring 12 is completed by the elastic sleeve 42. In order to prevent the extension ring 12 from being affected during the extension process, the elastic sheet 45 provided inside the extension ring 12 is used to support the inside of the extension ring 12, so as to ensure that the extension ring 12 can always fit with the valve wall and ensure the sealing of the connection;

[0048] An elastic sheet 45 is fixedly connected to the support column 44. The elastic sheet 45 is arranged in an arc shape. An air hole 46 is opened on the elastic sheet 45. The elastic sheet 45 fits tightly on the inner wall of the extension ring 12. A groove is opened at the connection between the extension ring 12 and the elastic sleeve 42. An extension belt 47 is embedded in the groove. The connection between the elastic sleeve 42 and the extension ring 12 is connected with the extension belt 47.

[0049] The elastic sleeve 42 is connected to the extension ring 12 through the connecting block 43. The connecting block 43 is located between the two groups of extension rings 12. The end of the elastic sleeve 42 is connected to the connecting block 43, and most of it is pressed between the extension rings 12. This design can make the extension distance of the elastic sleeve 42 longer when it is unfolded. At the same time, the U-shaped setting of the elastic sleeve 42 is between the two groups of extension rings 12, which can provide better support for the extension ring 12 and have better elastic performance. In addition, by opening a notch on the extension ring 12, the notch is obliquely opened on the extension ring 12, so that the extension ring 12 can provide a stress release path when it is subjected to external force or internal stress. When the extension ring 12 is subjected to load or expands due to temperature changes, the oblique notch allows a certain degree of deformation to avoid excessive stress concentration inside the structure. Since the extension belt 47 has good elasticity, when the extension ring 12 is slightly deformed, the extension belt 47 can play a role of elastic compensation. It can stretch or compress to maintain the overall integrity and sealing of the structure.

[0050] Compared with vertical or horizontal straight notches, oblique notches can disperse stress more evenly. The stress distribution at the edge of the oblique notch is relatively gentle, reducing the local stress peak and thus reducing the risk of damage to the structure due to stress concentration.

[0051] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0052] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A 660MW steam turbine high pressure bypass valve balance seal ring, comprising an upper seal ring (11), characterized in that: The bottom end of the upper sealing ring (11) is connected to an extension ring (12), the bottom end of the extension ring (12) is connected to a lower sealing ring (13), the upper surface of the upper sealing ring (11) is connected to a nickel wire graphite ring (14), the outer surface of the upper sealing ring (11) is connected to a side ring (15), the upper and lower surfaces of the extension ring (12) are connected to an elastic component (2), the elastic component (2) comprises a gasket (21), the upper and lower surfaces of the extension ring (12) are both connected to the gasket (21), a fixing column (22) is embedded in the interior of the gasket (21), and the fixing column (22) is used to connect the upper sealing ring (11) and the extension ring (12) together; The gasket (21) has a reserved groove (23) formed inside, a support sheet (24) is embedded inside the reserved groove (23), a nylon mesh (25) is connected to the surface of the support sheet (24), an inner sleeve (16) is connected to the inner side of the support sheet (24), and a built-in cavity (26) is formed inside the extension ring (12) and the inner sleeve (16); The bottom end of the upper sealing ring (11) is connected to an extension assembly (3), and the extension assembly (3) comprises a top supporting block (32). The bottom surface of the upper sealing ring (11) is connected to the top supporting block (32), and the top surface of the lower sealing ring (13) is connected to the bottom supporting block (31). A movable pin (34) is fixedly connected to the inside of the top supporting block (32), and a movable groove (33) is provided inside the bottom supporting block (31), and the movable pin (34) is embedded in the inside of the movable groove (33).

2. A 660MW steam turbine high pressure bypass valve balance seal ring according to claim 1, characterized in that: A support assembly (4) is embedded in the extension ring (12), the support assembly (4) comprises a connection block (43), a connection block (43) is embedded in the extension ring (12), a support column (44) is embedded in the extension ring (12), and the support column (44) and the connection block (43) are connected together.

3. A 660MW steam turbine high pressure bypass valve balance seal ring according to claim 2, characterized in that: The bottom end of the connection block (43) is fixedly connected with an elastic sleeve (42), and the elastic sleeve (42) is arranged between two groups of extension rings (12). The elastic sleeve (42) is arranged in a U shape.

4. A 660MW steam turbine high pressure bypass valve balance seal ring according to claim 3, characterized in that: The cavities opened inside the gasket (21), the extension ring (12) and the elastic sleeve (42) are connected, and the connection between the gasket (21), the extension ring (12) and the elastic sleeve (42) is sealed, and air is stored in the internal cavity formed by the gasket (21), the extension ring (12) and the elastic sleeve (42).

5. A 660MW steam turbine high pressure bypass valve balance seal ring according to claim 4, characterized in that: An air pressure valve (41) is embedded at the top end of the gasket (21), and air is transmitted to the interior of the gasket (21), the extension ring (12) and the elastic sleeve (42) by pushing the valve core of the air pressure valve (41).

6. A 660MW steam turbine high pressure bypass valve balance seal ring according to claim 2, characterized in that: An elastic sheet (45) is fixedly connected to the support column (44), the elastic sheet (45) is arranged in an arc shape, an air hole (46) is opened on the elastic sheet (45), and the elastic sheet (45) is tightly fitted on the inner wall of the extension ring (12).

7. A 660MW steam turbine high pressure bypass valve balance seal ring according to claim 6, characterized in that: A notch is provided at the connection between the extension ring (12) and the elastic sleeve (42), an extension belt (47) is embedded in the notch, and the connection between the elastic sleeve (42) and the extension ring (12) is connected with the extension belt (47).

8. A 660MW steam turbine high pressure bypass valve balance seal ring according to claim 1, characterized in that: The gasket (21), the extension ring (12) and the inner sleeve (16) form an integrated structure, and the outer wall of the extension ring (12) and the inner wall of the inner sleeve (16) are both corrugated.

9. A 660MW steam turbine high pressure bypass valve balance seal ring according to claim 1, characterized in that: The support sheets (24) are evenly distributed inside the reserved groove (23), and the support sheets (24) are used to separate the reserved groove (23) and the built-in cavity (26).

10. A 660MW steam turbine high pressure bypass valve balance seal ring according to claim 9, characterized in that: One side of the support sheet (24) is connected to the extension ring (12), and the other side of the support sheet (24) close to the inner sleeve (16) is connected to the inner sleeve (16).

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