A medium pressure main steam valve control seat

Abstract

The present invention relates to a medium-pressure main steam valve operating seat, comprising a main housing and a starting valve housing arranged on one side of the main housing; a spring base which can move up and down is arranged inside the main housing to partition the inside of the main housing into an upper oil chamber at the top and a lower oil chamber at the bottom; a connecting rod is arranged at the bottom of the spring base; an upper piston which can move up and down is arranged inside the starting valve housing to partition the starting valve housing into an upper reset oil chamber and a lower return oil chamber at the bottom; the return oil chamber is connected to a safety oil chamber through an oil return passage; the upper piston can move downward to block the oil return passage; the return oil chamber is connected to the upper oil chamber, and the safety oil chamber is connected to the lower oil chamber; the reset oil chamber is connected to the outside through a reset oil port, the return oil chamber is connected to the outside through a return oil port, and the safety oil chamber is connected to the outside through a safety oil port; the present invention presses the upper piston and blocks the return oil passage by introducing reset oil into the reset oil port, and does not need to manually lock the brake, thereby reducing the danger during the startup process.

Description

Technical Field

[0001] The invention relates to the technical field of steam turbines, and in particular to a medium-pressure main steam valve operating seat. Background Art

[0002] The main steam valve control seat of the steam turbine is connected to the main steam valve, and its main function is to open and close the main steam valve. In recent years, the automation requirements of power plants have gradually increased, and medium-pressure steam turbines have been moving towards remote locking and one-piece start and stop. The main steam valve control seat is an actuator to protect the safe operation of the unit, and the power plant's requirements for its closing time have also increased accordingly. The traditional main steam valve control seat must be locked manually, which increases the danger of the startup process. In addition, the traditional main steam valve control seat takes a long time to open and cannot perform the main steam valve activity test online. Summary of the invention

[0003] Based on the above description, the present invention provides a medium-pressure main steam valve operating seat, which can press the upper piston and block the return oil channel by introducing reset oil into the reset oil port, without the need for manual locking, thereby reducing the danger during the startup process.

[0004] The technical solution of the present invention to solve the above technical problem is as follows: a medium-pressure main steam valve operating seat, including a main housing and a starter valve housing arranged on one side of the main housing;

[0005] A spring base that can move up and down is arranged inside the main housing, dividing the interior of the main housing into an upper oil chamber at the top and a lower oil chamber at the bottom; a connecting rod is arranged at the bottom of the spring base;

[0006] An upper piston that can move up and down is arranged inside the start valve housing, which separates the start valve housing into an upper reset oil chamber and a lower return oil chamber; the return oil chamber is connected to a safety oil chamber through an oil return channel; the upper piston can move downward to block the return oil channel;

[0007] The oil return chamber is connected to the upper oil chamber, and the safety oil chamber is connected to the lower oil chamber;

[0008] The reset oil chamber is connected to the outside through a reset oil port, the return oil chamber is connected to the outside through a return oil port, and the safety oil chamber is connected to the outside through a safety oil port.

[0009] Based on the above technical solution, the present invention can also be improved as follows.

[0010] Furthermore, a spring top cover that can move up and down is also provided inside the main shell body, the spring top cover is located above the spring base, and the spring top cover and the spring base are connected by a plurality of main springs; the spring top cover separates the inside of the main shell body to form a test oil chamber above the upper oil chamber, and the test oil chamber is connected to the outside through a test oil port.

[0011] Furthermore, a housing upper cover is arranged on the top of the main housing, and the test oil port is arranged on the housing upper cover; an inner stop is arranged on the top of the main housing, and the spring top cover slides up and down in the inner stop.

[0012] Furthermore, a sliding seat protruding upward is provided at the bottom of the inner wall of the main shell, the spring base is slidably mounted on the sliding seat, and the connecting rod is slidably passed through the sliding seat up and down; the main shell forms the lower oil chamber between the inner wall around the sliding seat and the spring base, and a pressure-stabilizing chamber is formed between the top of the sliding seat and the spring base; and a pressure-stabilizing channel connecting the outside and the pressure-stabilizing chamber is also provided at the bottom of the main shell.

[0013] Furthermore, a first groove is arranged at the center of the top of the spring top cover, and the test oil port is arranged above the first groove; when the spring top cover moves to the uppermost end of the stroke, the spring top cover is tightly against the housing upper cover.

[0014] Furthermore, the top of the connecting rod protrudes from the top surface of the spring base; and the bottom of the spring top cover is provided with a protrusion adapted to the top of the connecting rod.

[0015] Furthermore, a lower piston that can move up and down is also provided in the starting valve housing. The lower piston is located below the upper piston, and the lower piston separates the inside of the starting valve housing to form the safety oil chamber below the return oil chamber. The return oil channel is provided on the lower piston.

[0016] Furthermore, the upper piston and the lower piston are connected via a starting valve spring; when the upper piston moves to the lowest end of the stroke, the upper piston is in close contact with the top surface of the lower piston.

[0017] Furthermore, a starting valve upper cover is arranged on the top of the starting valve housing, a second groove is arranged at the center of the bottom of the starting valve upper cover, and the reset oil port is arranged in the second groove.

[0018] Compared with the prior art, the technical solution of this application has the following beneficial technical effects:

[0019] 1. The present invention allows reset oil to be introduced into the reset oil port to compress the upper piston and block the oil return channel, eliminating the need for manual brake operation and reducing the risk during startup.

[0020] 2. By setting the lower piston, the safety oil pressure in the safety oil chamber gradually increases after the brake is engaged, pressing the lower piston tightly against the bottom of the upper piston. At this time, the reset oil can be disconnected; after the safety oil pressure is removed, the lower piston quickly falls and separates from the upper piston, and the safety oil quickly flows into the return oil port through the return oil channel. The safety oil pressure further accelerates the decline, and the brake operation time is short.

[0021] 3. By setting a spring top cover, a test oil chamber is formed above the spring top cover. Test oil can be introduced into the test oil chamber to push the spring top cover and the spring base to move downward together, thereby realizing the activity test of the main steam valve. In addition, by setting a slide seat, the cross-sectional area of ​​the lower oil chamber is reduced to ensure that the effective area of ​​the spring top cover is larger than the effective area of ​​the spring base during the activity test. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic structural diagram of a medium-pressure main steam valve operating seat provided by an embodiment of the present invention;

[0023] Figure 2 It is a structural schematic diagram of the main housing in an embodiment of the present invention;

[0024] Figure 3 It is a structural schematic diagram of a starter valve housing in an embodiment of the present invention;

[0025] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0026] 1. Main housing; 11. Main housing body; 111. Internal stop; 12. Housing cover; 121. Test oil port; 13. Housing cover; 131. Sliding seat; 132. Pressure stabilizing channel; 14. Spring top cover; 141. Protrusion; 142. First groove; 15. Spring base; 16. Connecting rod; 17. Main spring; 2. Starting valve housing; 21. Starting valve cover; 211. Second groove; 22. Starting valve base; 23. Upper piston; 24. Lower piston; 241. Oil return channel; 25. Starting valve spring; 26. Safety oil port; 27. Oil return port; 28. Reset oil port; 3. Steam chamber; A1. Lower oil chamber; A2. Upper oil chamber; A3. Test oil chamber; A4. Pressure stabilizing chamber; B1. Safety oil chamber; B2. Oil return chamber; B3. Reset oil chamber. DETAILED DESCRIPTION

[0027] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0029] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" etc. specify the presence of stated features, wholes, steps, operations, components, parts or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof.

[0030] A medium-pressure main steam valve operating seat comprises a main housing 1 and a starting valve housing 2 arranged on one side of the main housing 1.

[0031] The main housing 1 comprises a main housing body 11, a housing upper cover 12 sealedly arranged at the top of the main housing 11, and a housing lower cover 13 sealedly arranged at the bottom of the main housing 11. The bottom of the housing lower cover 13 is integrally connected to the steam chamber 3. The interior of the main housing 1 is provided with a spring top cover 14 and a spring base 15 which can be slid up and down in sequence from top to bottom, and a connecting rod 16 is also provided in the center of the spring base 15, the top of the connecting rod 16 protrudes from the top of the spring base 15 and is fixed to the spring base 15, and the bottom of the connecting rod 16 passes through the slide seat 131 up and down and extends into the steam chamber 3.

[0032] A sliding seat 131 protruding upward is provided at the center of the top of the housing lower cover 13, and the center of the spring base 15 can be slidably mounted on the sliding seat 131, so that a lower oil chamber A1 is formed between the top surface of the housing lower cover 13 around the sliding seat 131 and the bottom surface of the spring base 15, and a pressure stabilizing chamber A4 is formed between the top surface of the sliding seat 131 and the spring base 15. The housing lower cover 13 is also provided with a pressure stabilizing channel 132 connecting the pressure stabilizing chamber A4 and the outside.

[0033] An inner stop 111 is provided at the top of the inner wall of the main housing body 11, and the four peripheral edges of the spring top cover 14 slide up and down in the inner stop 111. The inner stop 111 is used to limit the movement range of the spring top cover 14. An upper oil chamber A2 is formed between the spring top cover 14 and the spring base 15, and the spring top cover 14 and the spring base 15 are connected by a plurality of main springs 17. A protrusion 141 adapted to the top of the connecting rod 16 is provided at the bottom of the spring top cover 14.

[0034] When the spring top cover 14 moves to the uppermost end of the stroke, the spring top cover 14 is in close contact with the housing upper cover 12. A first groove 142 is provided at the top center of the spring top cover 14, so that a test oil chamber A3 is formed between the spring top cover 14 and the housing upper cover 12. A test oil port 121 is provided on the housing upper cover 12, and the test oil port 121 is located above the first groove 142 and is connected to the test oil chamber A3 for inputting test oil into the test oil chamber A3.

[0035] The top of the start valve housing 2 is sealed with a start valve upper cover 21, and the bottom is sealed with a start valve base 22. An upper piston 23 and a lower piston 24 are slidably arranged in sequence from top to bottom in the start valve housing 2. The upper piston 23 and the lower piston 24 are connected by a start valve spring 25.

[0036] A safety oil chamber B1 is formed below the lower piston 24, and the safety oil chamber B1 is connected to the lower oil chamber A1. An oil return chamber B2 is formed between the upper piston 23 and the lower piston 24, and the oil return chamber B2 is connected to the upper oil chamber A2. An oil return passage 241 connecting the safety oil chamber B1 and the oil return chamber B2 is provided on the lower piston 24. When the upper piston 23 moves to the lowest end of the stroke, the upper piston 23 blocks the oil return passage 241.

[0037] In addition, when the upper piston 23 moves to the upper end of the stroke, the upper piston 23 is in close contact with the start valve upper cover 21. Therefore, a second groove 211 is provided at the bottom of the start valve upper cover 21 to ensure that a reset oil chamber B3 is formed between the start valve upper cover 21 and the upper piston 23. The on and off of the reset oil port 28 can be controlled by a set of latching solenoid valves.

[0038] A safety oil port 26 connected to the safety oil chamber B1 is provided on one side of the start valve housing 2, and safety oil is input into the safety oil chamber B1. A return oil port 27 connected to the return oil chamber B2 is also provided on one side of the start valve housing 2, and the safety oil flows into the return oil chamber B2 through the return oil channel 241, and then flows out through the return oil port 27. A reset oil port 28 is provided on the start valve upper cover 21, and the reset oil port 28 is connected to the second groove 211, thereby ensuring the connection with the reset oil chamber B3, and is used to input reset oil into the reset oil chamber B3.

[0039] Before the brake is engaged, only safety oil is introduced into the safety oil chamber B1, and the safety oil enters the oil return chamber B2 through the oil return channel 241, and then flows out through the oil return port 27, forming a complete cycle. At the same time, the lower oil chamber A1 is connected to the upper oil chamber A2 through the safety oil chamber B1 and the oil return chamber B2, thereby maintaining the oil pressure balance between the lower oil chamber A1 and the upper oil chamber A2.

[0040] When the brake is engaged, reset oil is introduced into the reset oil chamber B3, thereby pressing the upper piston 23 downward. The upper piston 23 blocks the return oil channel 241, and the safety oil cannot enter the return oil chamber B2, so that the oil pressure in the safety oil chamber B1 gradually rises, and the lower piston 24 is pressed against the bottom of the upper piston 23. At this time, the reset oil port 28 can be disconnected to stop inputting reset oil. At this time, the oil pressure in the lower oil chamber A1 rises, pushing the spring base 15 and the connecting rod 16 to move upward, opening the main steam valve, and the protrusion 141 first contacts the top of the connecting rod 16 to form a limit.

[0041] At this time, the active test oil can be input into the test oil chamber A3 through the solenoid valve. Due to the provision of the slide seat 131, the effective area of ​​the spring top cover 14 is larger than the effective area of ​​the spring base 15. The spring top cover 14 pushes the main spring 17 and the spring base 15 to move downward together, thereby completing the activity test of the main steam valve.

[0042] When the brake is applied, the safety oil pressure is released, and under the action of the starting valve spring 25, the lower piston 24 drops rapidly and separates from the upper piston 23, and the safety oil quickly enters the oil return chamber B2 through the oil return channel 241. The safety oil pressure further drops faster, and the spring base 15 rebounds under the action of the spring to close the main steam valve.

[0043] The present invention does not need manual locking, thus reducing the danger in the machine jam process, and the locking time is short, so that the activity test of the main steam valve can be carried out first.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A medium-pressure main steam valve operating seat, characterized in that: It includes a main housing and a start valve housing arranged on one side of the main housing; A spring base that can move up and down is arranged inside the main housing, dividing the interior of the main housing into an upper oil chamber at the top and a lower oil chamber at the bottom; a connecting rod is arranged at the bottom of the spring base; An upper piston that can move up and down is arranged inside the start valve housing, which separates the start valve housing into an upper reset oil chamber and a lower return oil chamber; the return oil chamber is connected to a safety oil chamber through an oil return channel; the upper piston can move downward to block the return oil channel; The oil return chamber is connected to the upper oil chamber, and the safety oil chamber is connected to the lower oil chamber; The reset oil chamber is connected to the outside through a reset oil port, the return oil chamber is connected to the outside through a return oil port, and the safety oil chamber is connected to the outside through a safety oil port; A spring top cover that can move up and down is also arranged inside the main housing, the spring top cover is located above the spring base, and the spring top cover and the spring base are connected through a plurality of main springs; the spring top cover separates the inside of the main housing to form a test oil chamber above the upper oil chamber, and the test oil chamber is connected to the outside through a test oil port; The top of the main housing is provided with a housing upper cover, and the test oil port is provided on the housing upper cover; the top of the main housing is provided with an inner stop, and the spring top cover slides up and down in the inner stop; A sliding seat protruding upward is arranged at the bottom of the inner wall of the main shell, the spring base is slidably mounted on the sliding seat, and the connecting rod is slidably passed through the sliding seat up and down; the main shell forms the lower oil chamber between the inner wall around the sliding seat and the spring base, and forms a pressure-stabilizing chamber between the top of the sliding seat and the spring base; a pressure-stabilizing channel connecting the outside and the pressure-stabilizing chamber is also arranged at the bottom of the main shell.

2. The medium-pressure main steam valve operating seat according to claim 1, characterized in that: A first groove is arranged at the center of the top of the spring top cover, and the test oil port is arranged above the first groove; when the spring top cover moves to the uppermost end of the stroke, the spring top cover is tightly against the housing upper cover.

3. The medium-pressure main steam valve operating seat according to claim 1, characterized in that: The top of the connecting rod protrudes from the top surface of the spring base; the bottom of the spring top cover is provided with a protrusion adapted to the top of the connecting rod.

4. The medium-pressure main steam valve operating seat according to claim 1, characterized in that: A lower piston that can move up and down is also arranged in the starting valve housing. The lower piston is located below the upper piston, and the lower piston separates the inside of the starting valve housing to form the safety oil chamber below the return oil chamber. The return oil channel is arranged on the lower piston.

5. The medium-pressure main steam valve operating seat according to claim 4, characterized in that: The upper piston and the lower piston are connected via a starting valve spring; when the upper piston moves to the lowest end of the stroke, the upper piston is in close contact with the top surface of the lower piston.

6. The medium-pressure main steam valve operating seat according to claim 1, characterized in that: A starting valve upper cover is arranged on the top of the starting valve housing, a second groove is arranged at the center of the bottom of the starting valve upper cover, and the reset oil port is arranged in the second groove.

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