High-low pressure bypass control valve for thermal power plant
By designing a sealing ring structure including an embedded groove and a return spring in the high and low pressure bypass control valve of a thermal power plant, the problem of sealing surface damage caused by wet steam erosion is solved, achieving higher sealing performance and more convenient maintenance.
Patent Information
- Application Number
- CN202420051605.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-09
- Publication Date
- 2025-01-21
- Estimated Expiration
- 2034-01-09
AI Technical Summary
When the high and low pressure bypass control valve of thermal power plants is closed, the valve core sealing surface is flushed due to the flushing of wet steam, which reduces the sealing effect and affects the normal use of the valve.
A high and low pressure bypass control valve including a valve core seal and an embedded groove is designed. The valve core seal is composed of a first sealing ring, a second sealing ring, a third sealing ring and a return spring. Through the embedded groove and sealing ring The cooperation prevents steam from directly washing the sealing ring, improves the sealing performance, and realizes the dynamic compensation of the sealing ring through the return spring.
It effectively prevents steam erosion from damaging the sealing ring, improves the sealing performance of the valve, ensures long-term stable operation of the control valve, and simplifies the maintenance and repair process.
Smart Images
Figure CN222377236U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of valve bodies and relates to a bypass control valve, in particular to a high- and low-pressure bypass control valve for a thermal power plant. Background Art
[0002] The main function of the high and low pressure bypass system of a thermal power plant is that when the automatic main steam valve of the unit trips and is suddenly closed, the large amount of steam generated by the boiler has nowhere to be discharged and the high-pressure cylinder cannot exhaust steam, which will cause the boiler's reheater to dry burn. To ensure that the reheater does not dry burn, when the automatic main steam valve is closed, the high-pressure bypass steam control valve is quickly opened, and the high-temperature and high-pressure steam is discharged through the bypass steam control valve. However, when the control valve is closed, a large amount of wet steam will be flushed on the valve core. Due to the fast flow rate of steam, the wet steam with water droplets will erode the valve core greatly. Over time, it will erode the sealing surface of the valve core, reducing the sealing effect of the valve core, which will affect the normal use of the control valve in the long run. Utility Model Content
[0003] In order to solve the above technical problems existing in the background technology, the utility model provides a high and low pressure bypass control valve for a thermal power plant which has good sealing performance and is easy to inspect and maintain.
[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:
[0005] A high and low pressure bypass control valve for a thermal power plant, characterized in that: the high and low pressure bypass control valve for a thermal power plant comprises a lower valve body, an upper valve body, a valve stem and a valve core; the lower valve body is movably connected to the upper valve body; the valve stem is arranged in the upper valve body along the axial direction of the upper valve body and extends from the upper valve body to the lower valve body; a valve core is sleeved on the valve stem; the valve stem drives the valve core to move freely in the upper valve body along the axial direction of the upper valve body; an embedding groove is arranged on the lower valve body; a valve core seal is arranged on the circumference of the valve core; the valve core is sealed with the lower valve body through the valve core seal and the embedding groove.
[0006] The above-mentioned valve core seal includes a first sealing ring, which is arranged on the peripheral side of the valve core. When the valve stem drives the valve core to move toward the lower valve body, the valve core drives the first sealing ring to be embedded in the embedding groove; the valve core is sealed with the lower valve body through the first sealing ring and the embedding groove.
[0007] The above-mentioned valve core seal also includes an annular groove opened on the circumferential side of the valve core; the first sealing ring is placed in the annular groove; the side wall of the first sealing ring protrudes from the side of the annular groove; the embedded groove is L-shaped as a whole; when the valve stem drives the valve core to move toward the lower valve body, the annular groove is placed in the embedded groove as a whole, and the first sealing ring is squeezed on the side wall of the embedded groove.
[0008] The above-mentioned valve core seal also includes a second sealing ring and a sealing ring extrusion piece; the second sealing ring is arranged in an annular groove opposite to the first sealing ring; the sealing ring extrusion piece is placed inside the annular groove; the sealing ring extrusion piece is placed between the second sealing ring and the first sealing ring; the axial direction of the sealing ring extrusion piece is perpendicular to the axial direction of the line connecting the second sealing ring and the first sealing ring.
[0009] The structure of the second sealing ring is completely the same as that of the first sealing ring, and the second sealing ring is trapezoidal in shape as a whole; the sealing ring extrusion piece is tightly matched with the second sealing ring and the inclined surface of the first sealing ring.
[0010] The above-mentioned sealing ring extrusion part includes a return spring and a third sealing ring connected to the return spring; the axial direction of the line connecting the return spring and the third sealing ring is perpendicular to the axial direction of the line connecting the second sealing ring and the first sealing ring; the third sealing ring is tightly fitted with the second sealing ring and the first sealing ring inclined surface respectively.
[0011] The above-mentioned return spring is placed at the top and / or bottom of the annular groove; the number of the third sealing rings is the same as the number of the return springs.
[0012] The above-mentioned high and low pressure bypass control valve of the thermal power plant further comprises a valve body connector; the lower valve body is movably connected to the upper valve body via the valve body connector.
[0013] The above-mentioned valve body connecting part includes a rotating seat, a clamp, a limit groove, a screw and a limit block; the upper valve body is provided with a limit groove; the lower valve body is provided with a rotating seat; the clamp is in the shape of a] as a whole; the bottom of the clamp extends into the rotating seat; the top of the clamp is provided with a pipe through hole; the screw is placed in the pipe through hole and is threadedly connected to the pipe through hole; the limit block is placed at the end of the screw; when the screw moves downward along the axial direction of the pipe through hole, the limit block is placed in the limit groove.
[0014] A guide groove is arranged in the upper valve body along the axial direction of the upper valve body, and guide balls are evenly distributed in the guide groove; the valve stem is placed in the guide groove and moves freely in the guide groove through the guide balls.
[0015] Compared with the prior art, the advantages of the utility model are:
[0016] The utility model provides a high and low pressure bypass control valve for a thermal power plant, which comprises a lower valve body, an upper valve body, a valve stem and a valve core; the lower valve body is movably connected with the upper valve body; the valve stem is placed in the upper valve body along the axial direction of the upper valve body and extends from the upper valve body to the lower valve body; a valve core is mounted on the valve stem; the valve stem drives the valve core to move freely in the upper valve body along the axial direction of the upper valve body; an embedding groove is arranged on the lower valve body; a valve core seal is arranged on the circumference of the valve core; the valve core is sealed with the lower valve body through the valve core seal and the embedding groove. The high and low pressure bypass control valve for a thermal power plant provided by the utility model connects the control valve with the steam inlet pipe and outlet pipe of the low pressure bypass system of the thermal power plant through the valve core seal and the embedding groove. When the control valve is closed, the first sealing ring of the valve core seal is embedded in the embedding groove when the valve core moves downward, and the first sealing ring is protected by the embedding groove to avoid direct scouring of the first sealing ring when steam enters, so that the first sealing ring is not easily damaged and affects the sealing performance. At the same time, the valve core seal used in the utility model also includes a second sealing ring, a third sealing ring and a reset spring. The two ends of the third sealing ring are respectively tightly matched with the inclined surfaces of the first sealing ring and the second sealing ring, and a pressure is applied to the first sealing ring in the direction of the embedding groove, so that the first sealing ring is tightly attached to the embedding groove to improve the sealing performance. If the first sealing ring is worn, under the action of the reset spring, the third sealing ring can push the first sealing ring and the second sealing ring to dynamically fill the position, so that the first sealing ring is always tightly attached to the embedding groove to ensure the airtightness of the control valve. In addition, the utility model is connected with a clamp through a rotating seat on both sides of the top of the lower valve body. The top of the clamp passes through the screw rod vertically, and the bottom of the screw rod is provided with a limit block. The bottom of both sides of the upper valve body is provided with a limit groove. The rotating screw rod drives the limit block to connect with the limit groove, so that the upper valve body and the lower valve body can be connected and fixed, which is convenient for the disassembly and assembly of the control valve, and convenient for its inspection and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a front view cross-sectional structural diagram of a high and low pressure bypass control valve of a thermal power plant provided by the utility model;
[0018] Figure 2 yes Figure 1 The enlarged structural diagram at A in the middle;
[0019] Figure 3 yes Figure 1 The enlarged structural diagram at B in the middle;
[0020] Figure 4 yes Figure 1 The enlarged structural diagram at C in the middle;
[0021] Figure 5 It is a side view structural schematic diagram of the lower valve body adopted by the utility model;
[0022] In the figure:
[0023] 1-lower valve body; 2-upper valve body; 3-valve stem; 4-valve core; 5-steam inlet; 6-steam outlet; 7-embedded groove; 8-first sealing ring; 9-reset spring; 10-annular groove; 11-second sealing ring; 12-third sealing ring; 13-guide groove; 14-guide ball; 15-rotating seat; 16-clamp; 17-limiting groove; 18-screw; 19-limiting block; 20-connecting hole. DETAILED DESCRIPTION
[0024] See also Figure 1 The utility model provides a high- and low-pressure bypass control valve for a thermal power plant, comprising a lower valve body 1, an upper valve body 2, a valve stem 3 and a valve core 4; the lower valve body 1 is movably connected to the upper valve body 2; the valve stem 3 is arranged in the upper valve body 2 along the axial direction of the upper valve body 2 and extends from the upper valve body 2 to the lower valve body 1; a valve core 4 is sleeved on the valve stem 3; the valve stem 3 drives the valve core 4 to move freely in the upper valve body 2 along the axial direction of the upper valve body 2; an embedding groove 7 is arranged on the lower valve body 1; a valve core seal is arranged on the peripheral side of the valve core 4; the valve core 4 is sealed with the lower valve body 1 through the valve core seal and the embedding groove 7.
[0025] See also Figure 1 as well as Figure 4 The valve core seal includes a first seal ring 8, which is arranged on the side of the valve core 4. When the valve stem 3 drives the valve core 4 to move toward the lower valve body 1, the valve core 4 drives the first seal ring 8 to be embedded in the embedding groove 7; the valve core 4 is sealed with the lower valve body 1 through the first seal ring 8 and the embedding groove 7. When the control valve is closed, the valve stem 3 drives the valve core 4 to move downward, so that the first seal ring 8 is embedded in the embedding groove 7. The first seal ring 8 is protected by the embedding groove 7 to prevent the first seal ring 8 from being directly eroded when steam enters, so that the first seal ring 8 is not easily damaged and affects the sealing performance.
[0026] In order to facilitate the installation of the first sealing ring 8, the valve core seal used in the utility model also includes an annular groove 10 opened on the side of the valve core 4; the first sealing ring 8 is placed in the annular groove 10; the side wall of the first sealing ring 8 protrudes from the side of the annular groove 10; the embedded groove 7 is L-shaped as a whole; when the valve stem 3 drives the valve core 4 to move toward the lower valve body 1, the annular groove 10 is placed in the embedded groove 7 as a whole, and the first sealing ring 8 is squeezed on the side wall of the embedded groove 7. When the first sealing ring 8 is used for a long time, it may cause the problem of reduced sealing effect of the first sealing ring 8. The valve core seal provided by the utility model also includes a second sealing ring 11 and a sealing ring extrusion piece; the second sealing ring 11 is arranged in the annular groove 10 relative to the first sealing ring 8; the sealing ring extrusion piece is placed inside the annular groove 10; the sealing ring extrusion piece is placed between the second sealing ring 11 and the first sealing ring 8; the axial direction of the sealing ring extrusion piece is perpendicular to the axial direction of the line connecting the second sealing ring 11 and the first sealing ring 8. The structure of the second sealing ring 11 is completely the same as that of the first sealing ring 8. The second sealing ring 11 is trapezoidal in shape as a whole. The sealing ring extrusion piece fits tightly with the second sealing ring 11 and the inclined surface of the first sealing ring 8. The sealing ring extrusion piece includes a reset spring 9 and a third sealing ring 12 connected to the reset spring 9. The axial direction of the line connecting the reset spring 9 and the third sealing ring 12 is perpendicular to the axial direction of the line connecting the second sealing ring 11 and the first sealing ring 8. The third sealing ring 12 fits tightly with the inclined surface of the second sealing ring 11 and the first sealing ring 8 respectively. The reset spring 9 is placed at the top and / or bottom of the annular groove 10. The number of the third sealing rings 12 is the same as the number of the reset springs 9. See Figure 4 , exemplarily, the sealing ring extrusion parts used in the utility model are two groups, which are respectively arranged at the top and bottom of the annular groove 10. The two groups of sealing ring extrusion parts squeeze the third sealing ring 12 between the second sealing ring 11 and the first sealing ring 8 under the action of the reset spring 9 at the same time, so that the third sealing ring 12 can push the first sealing ring 8 and the second sealing ring 11 to move to both sides, so that the first sealing ring 8 can always be tightly squeezed on the embedded groove 7, so as to realize the dynamic compensation of the third sealing ring 12 to the first sealing ring 8 and the second sealing ring 11, and ensure the airtightness of the control valve. Exemplarily, the first sealing ring 8, the second sealing ring 11 and the third sealing ring 12 are all made of silicone material, which has good high temperature resistance.
[0027] See also Figure 1 as well as Figure 3The high and low pressure bypass control valve of the thermal power plant also includes a valve body connector; the lower valve body 1 is movably connected to the upper valve body 2 through the valve body connector. The valve body connector includes a rotating seat 15, a clamp 16, a limit groove 17, a screw 18 and a limit block 19; the upper valve body 2 is provided with a limit groove 17, and the structure of the limit groove 17 matches the limit block 19; the lower valve body 1 is provided with a rotating seat 15; the clamp 16 is in the shape of a] as a whole; the bottom of the clamp 16 extends into the rotating seat 15; the top of the clamp 16 is provided with a pipe through hole; the screw 18 is placed in the pipe through hole and is threadedly connected with the pipe through hole; the limit block 19 is placed at the end of the screw 18; when the screw 18 moves downward along the axial direction of the pipe through hole, the limit block 19 is placed in the limit groove 17. The connecting clamp 16 is rotated by rotating the seat 15, and the top of the clamp 16 vertically passes through the screw 18. The rotating screw 18 drives the limit block 19 to connect with the limit groove 17, so that the upper valve body 2 and the lower valve body 1 can be connected and fixed, which is convenient for the disassembly and assembly of the control valve and the inspection and maintenance thereof.
[0028] See also Figure 1 as well as Figure 2 A guide groove 13 is arranged in the upper valve body 2 along the axial direction of the upper valve body 2, and guide balls 14 are evenly distributed in the guide groove; the valve stem 3 is placed in the guide groove 13 and moves freely in the guide groove 13 through the guide balls 14 to reduce friction.
[0029] See also Figure 1 as well as Figure 5 The high and low pressure bypass control valve of a thermal power plant provided by the utility model is provided with a steam inlet 5 on one side of the lower valve body 1, and a steam outlet 6 on the other side of the lower valve body 1. Connection holes 20 are evenly opened at the edges of both sides of the lower valve body 1, and the connection holes 20 are provided in 4 groups. The control valve is connected to the steam inlet pipe and outlet pipe of the low pressure bypass system of the thermal power plant through the connection holes 20.
[0030] When the utility model is in use, the two sides of the top of the lower valve body 1 are rotatably connected with the clamping piece 16 through the rotating seat 15, and the top of the clamping piece 16 vertically passes through the screw 18. The rotating screw 18 drives the limit block 19 to connect with the limit groove 17, so that the upper valve body 2 and the lower valve body 1 can be connected and fixed. Then, the control valve is connected to the steam inlet pipe and outlet pipe of the low-pressure bypass system of the thermal power plant through the connecting hole 20. When the control valve is closed, the valve stem 3 drives the valve core 4 to move downward, so that the first sealing ring 8 is embedded in the embedding groove 7, and the first sealing ring 8 is protected by the embedding groove 7. The two ends of the third sealing ring 12 in the annular groove 10 are tightly matched with the inclined surfaces of the first sealing ring 8 and the second sealing ring 11, respectively, and pressure is applied to the first sealing ring 8 in the direction of the embedding groove 7, so that the first sealing ring 8 is tightly attached to the embedding groove 7 to improve the sealing performance. If the first sealing ring 8 is worn, under the action of the reset spring 9, the third sealing ring 12 can push the first sealing ring 8 and the second sealing ring 11 to dynamically compensate for the position, so that the first sealing ring 8 is always tightly attached to the embedding groove 7, thereby ensuring the airtightness of the control valve.
Claims
1. A high and low pressure bypass control valve for a thermal power plant, characterized in that: The high- and low-pressure bypass control valve of a thermal power plant comprises a lower valve body (1), an upper valve body (2), a valve stem (3) and a valve core (4); the lower valve body (1) is movably connected to the upper valve body (2); the valve stem (3) is arranged in the upper valve body (2) along the axial direction of the upper valve body (2) and extends from the upper valve body (2) to the lower valve body (1); the valve core (4) is sleeved on the valve stem (3); the valve stem (3) drives the valve core (4) to move freely in the axial direction of the upper valve body (2) in the upper valve body (2); an embedding groove (7) is arranged on the lower valve body (1); a valve core seal is arranged on the circumferential side of the valve core (4); the valve core (4) is sealed with the lower valve body (1) through the valve core seal and the embedding groove (7).
2. The high and low pressure bypass control valve for thermal power plants according to claim 1, characterized in that: The valve core seal comprises a first sealing ring (8), which is arranged on the circumferential side of the valve core (4). When the valve stem (3) drives the valve core (4) to move toward the lower valve body (1), the valve core (4) drives the first sealing ring (8) to be embedded in the embedding groove (7); the valve core (4) is sealed with the lower valve body (1) via the first sealing ring (8) and the embedding groove (7).
3. The high and low pressure bypass control valve for thermal power plants according to claim 2, characterized in that: The valve core seal also includes an annular groove (10) provided on the circumferential side of the valve core (4); the first sealing ring (8) is placed in the annular groove (10); the side wall of the first sealing ring (8) protrudes from the side of the annular groove (10); the embedded groove (7) is L-shaped as a whole; when the valve stem (3) drives the valve core (4) to move toward the lower valve body (1), the annular groove (10) is placed in the embedded groove (7) as a whole, and the first sealing ring (8) is squeezed on the side wall of the embedded groove (7).
4. The high and low pressure bypass control valve for thermal power plants according to claim 3 is characterized in that: The valve core seal also includes a second sealing ring (11) and a sealing ring extrusion piece; the second sealing ring (11) and the first sealing ring (8) are arranged in the annular groove (10) relative to each other; the sealing ring extrusion piece is placed inside the annular groove (10); the sealing ring extrusion piece is placed between the second sealing ring (11) and the first sealing ring (8); the axial direction of the sealing ring extrusion piece is perpendicular to the axial direction of the line connecting the second sealing ring (11) and the first sealing ring (8).
5. The high and low pressure bypass control valve for thermal power plants according to claim 4, characterized in that: The structure of the second sealing ring (11) is completely the same as that of the first sealing ring (8), and the second sealing ring (11) is trapezoidal in shape as a whole; the sealing ring extrusion piece is tightly fitted with the second sealing ring (11) and the inclined surface of the first sealing ring (8).
6. The high and low pressure bypass control valve for thermal power plants according to claim 5, characterized in that: The sealing ring extrusion component comprises a return spring (9) and a third sealing ring (12) connected to the return spring (9); the axial direction of the line connecting the return spring (9) and the third sealing ring (12) is perpendicular to the axial direction of the line connecting the second sealing ring (11) and the first sealing ring (8); the third sealing ring (12) is tightly fitted with the inclined surfaces of the second sealing ring (11) and the first sealing ring (8), respectively.
7. The high and low pressure bypass control valve for thermal power plants according to claim 6, characterized in that: The return spring (9) is placed at the top and / or bottom of the annular groove (10); the number of the third sealing rings (12) is the same as the number of the return springs (9).
8. The high and low pressure bypass control valve for a thermal power plant according to any one of claims 1 to 7, characterized in that: The high and low pressure bypass control valve of a thermal power plant further comprises a valve body connecting piece; the lower valve body (1) is movably connected to the upper valve body (2) via the valve body connecting piece.
9. The high and low pressure bypass control valve for thermal power plants according to claim 8, characterized in that: The valve body connecting member comprises a rotating seat (15), a clamping member (16), a limiting groove (17), a screw rod (18) and a limiting block (19); the upper valve body (2) is provided with a limiting groove (17); the lower valve body (1) is provided with a rotating seat (15); the clamping member (16) is in the shape of a ] as a whole; the bottom of the clamping member (16) extends into the rotating seat (15); the top of the clamping member (16) is provided with a pipe through hole; the screw rod (18) is placed in the pipe through hole and is threadedly connected to the pipe through hole; the limiting block (19) is placed at the end of the screw rod (18); when the screw rod (18) moves downward along the axial direction of the pipe through hole, the limiting block (19) is placed in the limiting groove (17).
10. The high and low pressure bypass control valve for thermal power plants according to claim 9, characterized in that: A guide groove (13) is provided in the upper valve body (2) along the axial direction of the upper valve body (2), and guide balls (14) are evenly distributed in the guide groove; the valve stem (3) is placed in the guide groove (13) and moves freely in the guide groove (13) through the guide balls (14).