Main throttle valve of steam turbine

Abstract

The invention discloses a steam turbine main throttle valve which comprises a valve body assembly, the valve body assembly comprises a valve shell, a connecting pipe and an adjusting pipe which are sequentially connected, a fixing plate is arranged in the connecting pipe, and an air inlet pipe is arranged on one side of the valve shell in a communicating mode. The cooling liquid in the cavity enters the driving cavity through the first through hole, the pressure in the driving cavity is gradually increased along with continuous injection of the liquid, downward thrust is formed, the sealing piece is pushed to move downwards and enter the valve seat, a steam channel is blocked, and in the whole working process, the cooling liquid is used for driving the sealing piece to move; the cooling liquid effectively avoids damage of high temperature to electrical elements, and stable operation of a driving system is guaranteed; and on the other hand, stable, continuous and strong thrust can be provided through cooling liquid driving, it is guaranteed that the sealing piece acts accurately and responds rapidly, and safe and efficient operation of the steam turbine is powerfully guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of steam turbines, and particularly to the main steam valve of a steam turbine. Background Art

[0002] The main steam valve of a steam turbine is the first valve of the steam turbine. By opening and closing the main steam valve, the supply and cut-off of steam to the steam turbine are achieved. Therefore, the main steam valve operates in a high-temperature and high-pressure steam environment for a long time.

[0003] Currently, in order to achieve automation, the main steam valve often uses an electric drive method. However, in this case, high-temperature fluid will transfer heat to the electric actuator through structures such as the valve body. Under the condition of continuously maintaining high temperature, the electric actuator may fail and be unable to start working. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides the following technical solutions:

[0005] The main steam valve of a steam turbine includes:

[0006] A valve body assembly, which includes a valve shell, a connecting pipe, and an adjusting pipe connected in sequence. A fixing plate is arranged in the connecting pipe. An air inlet pipe is communicated with one side of the valve shell. A sealing member is arranged in the adjusting pipe. The bottom of the sealing member penetrates through the fixing plate and extends outside the fixing plate. A valve seat is arranged at the connection between the connecting pipe and the adjusting pipe. An air outlet pipe is arranged on the side wall of the connecting pipe and between the fixing plate and the valve seat;

[0007] A partition plate is arranged in the adjusting pipe and above the sealing member. The partition plate divides the adjusting pipe into a flow chamber and a driving chamber from top to bottom in sequence. A chamber is opened in the partition plate. A through hole two for communicating the chamber with the flow chamber is opened at the top of the partition plate. A through hole one for communicating the chamber with the driving chamber is opened at the bottom of the partition plate;

[0008] A driving member is arranged on the adjusting pipe;

[0009] Among them, when the driving member is started, the through hole two is closed and the through hole one is opened, so that the liquid in the chamber enters the driving chamber through the through hole one, driving the sealing member to move downward into the valve seat.

[0010] As an improvement of the above technical solution, the driving member includes an electric push rod, a fixing rod arranged at the output end of the electric push rod, and a bulging part arranged on the fixing rod. The bulging part is adapted to the through hole one and the through hole two, and the height of the chamber is greater than the height of the bulging part.

[0011] As an improvement of the above technical solution, the seal includes a piston movably disposed in the adjusting pipe and a valve stem fixedly disposed at the bottom of the piston. The valve stem penetrates through the fixing plate and extends outside the fixing plate. One end of the valve stem extending outside the fixing plate is fixedly connected with a valve core adapted to the valve seat, and a first spring is wound around a section of the surface of the valve stem above the fixing plate.

[0012] As an improvement of the above technical solution, a water inlet pipe communicating with the chamber is provided on the side wall of the adjusting pipe. An adjusting member is provided at the bottom of the water inlet pipe, and the bottom of the adjusting member is communicated with the driving chamber through a connecting pipe.

[0013] As an improvement of the above technical solution, the adjusting member includes an installation pipe provided at the bottom of the water inlet pipe and a sealing plug movably disposed in the installation pipe and adapted to the water inlet pipe. A second spring is provided between the bottom of the sealing plug and the bottom inner wall of the installation pipe.

[0014] As an improvement of the above technical solution, a water outlet pipe is communicated with one side of the flow chamber.

[0015] Advantages of the present invention:

[0016] By moving the driving member, the through hole two is closed, the communication between the flow chamber and the chamber is blocked, the through hole one is opened, and the cooling liquid in the chamber enters the driving chamber through the through hole one. As the liquid is continuously injected, the pressure in the driving chamber gradually increases, forming a downward thrust, pushing the seal downward and into the valve seat, blocking the steam channel. In the whole working process, the cooling liquid is used to drive the seal to move. On the one hand, the cooling liquid effectively avoids the damage of high temperature to electrical components and ensures the stable operation of the driving system; on the other hand, the cooling liquid drive can provide a stable, continuous and strong thrust, ensure the accurate action and rapid response of the seal, enable the main steam valve to flexibly switch between opening and closing, and effectively ensure the safe and efficient operation of the steam turbine. Description of the drawings

[0017] Figure 1 It is the front view of the overall structure of the present invention;

[0018] Figure 2 It is the schematic structural diagram of the present invention when the water inlet pipe is in a sealed state;

[0019] Figure 3 It is the schematic structural diagram of the present invention when the bulged part is located in the chamber;

[0020] Figure 4 For the present invention Figure 1 The enlarged structural diagram at A in

[0021] Reference Numerals: 10, valve housing; 101, intake pipe; 11, connecting pipe; 12, fixing plate; 13, adjusting pipe; 14, partition plate; 141, chamber; 142, first through hole; 143, second through hole; 15, outlet pipe; 16, valve seat; 20, electric push rod; 21, fixing rod; 22, enlarged portion; 30, piston; 31, valve stem; 32, first spring; 33, valve core; 40, water inlet pipe; 50, water outlet pipe; 60, adjusting member; 61, sealing plug; 62, second spring; 63, communicating pipe; 64, mounting pipe. Detailed Embodiment

[0022] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0023] The main steam valve of a steam turbine, a valve body assembly, the valve body assembly includes a valve housing 10, a connecting pipe 11 and an adjusting pipe 13 connected in sequence, a fixing plate 12 is arranged in the connecting pipe 11, an intake pipe 101 is communicated and arranged on one side of the valve housing 10, a sealing member is arranged in the adjusting pipe 13, the bottom of the sealing member penetrates through the fixing plate 12 and extends to the outside of the fixing plate 12, a valve seat 16 is arranged at the connection between the connecting pipe 11 and the adjusting pipe 13, and an outlet pipe 15 is arranged on the side wall of the connecting pipe 11 and between the fixing plate 12 and the valve seat 16;

[0024] A partition plate 14 is arranged in the adjusting pipe 13 and above the sealing member, the partition plate 14 divides the adjusting pipe 13 into a flow chamber and a driving chamber from top to bottom in sequence, a chamber 141 is opened in the partition plate 14, a second through hole 143 for communicating the chamber 141 with the flow chamber is opened at the top of the partition plate 14, and a first through hole 142 for communicating the chamber 141 with the driving chamber is opened at the bottom of the partition plate 14;

[0025] A driving member is arranged on the adjusting pipe 13;

[0026] Wherein, when the driving member is started, the second through hole 143 is controlled to be closed and the first through hole 142 is opened, so that the liquid in the chamber 141 enters the driving chamber through the first through hole 142, and the sealing member is driven to move downward into the valve seat.

[0027] Specifically, when the sealing member is located above the valve seat 16, the main steam valve is in an open state, steam enters the valve housing 10 from the intake pipe 101 and then flows out through the outlet pipe 15 of the connecting pipe 11. When it is necessary to disconnect the main steam valve, refer to Figure 1, start the driving member to move the driving member, close the second through hole 143 to block the communication between the flow chamber and the chamber 141, open the first through hole 142, and enable the cooling liquid in the chamber 141 to enter the driving chamber through the first through hole 142. As the liquid is continuously injected, the pressure in the driving chamber gradually increases, forming a downward thrust to push the sealing member downward and into the valve seat 16 to block the steam passage. During the entire working process, the cooling liquid is used to drive the movement of the sealing member. On the one hand, the cooling liquid effectively avoids the damage of high temperature to electrical components and ensures the stable operation of the driving system; on the other hand, the cooling liquid drive can provide a smooth, continuous and strong thrust to ensure the accurate action and rapid response of the sealing member, enabling the main steam valve to flexibly switch between opening and closing, and effectively ensuring the safe and efficient operation of the steam turbine.

[0028] In one embodiment, the driving member includes an electric push rod 20, a fixed rod 21 disposed at the output end of the electric push rod 20, and a bulging portion 22 disposed on the fixed rod 21. The bulging portion 22 is adapted to the first through hole 142 and the second through hole 143, and the height of the chamber 141 is greater than the height of the bulging portion 22.

[0029] When the main steam valve of the steam turbine is in the open state, the bulging portion 22 is at the position of the first through hole 142. At this time, the chamber 141 is disconnected from the driving chamber, and the second through hole 143 remains open. The chamber 141 is connected to the flow chamber, and the liquid in the chamber enters the flow chamber through the second through hole 143, which can cool and dissipate heat from the fixed rod 21, ensuring that the electric push rod 20 and the fixed rod 21 connected thereto can also operate stably in a high-temperature environment, avoiding failures due to overheating, and ensuring the continuous stability of the open state of the main steam valve. When the main steam valve needs to be disconnected, the electric push rod 20 drives the fixed rod 21 to move, so that the fixed rod 21 drives the bulging portion 22 to move to the position of the second through hole 143. Refer to Figure 1 , at this time, the second through hole 143 is disconnected from the chamber 141, while the first through hole 142 is connected to the chamber. The cooling liquid in the chamber 141 flows into the driving chamber through the first through hole 142. As the liquid in the driving chamber continuously increases, the pressure gradually rises, thereby pushing the sealing member downward. The sealing member finally enters the valve seat 16 to block the steam passage.

[0030] In one embodiment, the sealing member includes a piston 30 movably disposed in the adjusting pipe 13 and a valve rod 31 fixedly disposed at the bottom of the piston 30. The valve rod 31 penetrates through the fixing plate 12 and extends outside the fixing plate 12. One end of the valve rod 31 extending outside the fixing plate 12 is fixedly connected with a valve core 33 adapted to the valve seat 16. A first spring 32 is wound around a section of the surface of the valve rod 31 above the fixing plate 12.

[0031] When the through hole 142 is opened and the cooling liquid enters the driving chamber, it acts on the piston 30, causing the piston 30 to drive the valve rod 31 to move downward, compressing the first spring 32. The valve rod 31 drives the valve core 33 to fall into the valve seat 16, and the two are in close contact, realizing the sealing of the steam passage and preventing the steam from flowing continuously. When the main steam valve needs to be reopened, the driving member acts again, causing the bulged portion 22 to be located in the chamber. Refer to Figure 3 , the liquid in the driving chamber flows into the chamber 141 through the through hole 142, and then flows into the flow chamber through the chamber 141. Therefore, the pressure in the driving chamber decreases. At this time, under the restoring elastic force of the first spring 32, the first spring 32 drives the piston 30 to move upward through the valve rod 31, pushing the liquid in the driving chamber into the chamber 141 through the through hole 142, and then flowing to the flow chamber through the through hole 143 and then flowing out of the valve body assembly. The piston 30 drives the valve rod 31 and the valve core 33 to move upward, and the valve core 33 gradually disengages from the valve seat 16, and the steam passage is reopened. The main steam valve resumes the open state, and the steam can enter the subsequent system of the steam turbine normally.

[0032] In one embodiment, a water inlet pipe 40 communicating with the chamber 141 is provided on the side wall of the regulating pipe 13. The bottom of the water inlet pipe 40 is extended with a regulating member 60. The bottom of the regulating member 60 is communicated with the driving chamber through a communicating pipe 63. The regulating member 60 includes a mounting pipe 64 provided at the bottom of the water inlet pipe 40 and a sealing plug 61 movably arranged in the mounting pipe 64 and adapted to the water inlet pipe 40. A second spring 62 is provided between the bottom of the sealing plug 61 and the inner wall bottom of the mounting pipe 64. Since the communicating pipe 63 is communicated with the driving chamber, the pressure in the driving chamber is the same as the pressure in the mounting pipe 64. Initially, the sealing plug 61 only moves upward partially under the resistance of the downward elastic force of the second spring 62, and the opening degree of the water inlet pipe 40 gradually decreases, and the flow rate of the cooling liquid flowing into the driving chamber decreases accordingly, avoiding excessive increase in the pressure in the driving chamber in a short time and affecting the stability of the movement of the piston 30. As the pressure in the driving chamber continues to rise, the piston 30 moves downward continuously. When the piston 30 reaches the lowest position, the valve core 33 is in close contact with the valve seat 16, and the main steam valve is completely closed. At this time, the pressure in the driving chamber reaches the peak value. This pressure acts on the bottom of the sealing plug 61 through the communicating pipe 63, and the upward thrust is much greater than the elastic force of the second spring 62. The sealing plug 61 is pushed to the highest position, completely blocking the water inlet pipe 40. Refer to Figure 2, the cooling liquid can no longer enter the driving cavity, preventing excessive accumulation of liquid in the driving cavity due to continuous inflow of the coolant, avoiding jamming after the main valve closes, or being difficult to operate when the main valve is reopened due to excessive liquid and pressure in the driving cavity. When the main steam valve needs to be reopened, the driving member moves, and the bulging portion 22 changes its position so that the bulging portion 22 is located within the chamber 141, and the liquid in the driving cavity can flow out. Since the sealing plug 61 has blocked the water inlet pipe 40 under the action of the peak pressure in the driving cavity when the main steam valve was closed before, when the main steam valve starts to reopen, the fluid pressure in the water inlet pipe 40 has little effect on the piston 30. At the same time, due to the restoring elastic force of the first spring 32, the piston 30 moves upward, pushing the liquid in the driving cavity into the chamber 141. The liquid in the driving cavity flows into the flow cavity through the chamber 141, the pressure in the driving cavity decreases, and the pressure in the installation pipe 64 also drops synchronously with the pressure in the driving cavity. During the process of gradually restoring its deformation, the second spring 62 exerts a downward pulling force on the sealing plug 61. Under the action of the second spring 62, the sealing plug 61 slowly moves downward, and the opening degree of the water inlet pipe 40 gradually increases, allowing the cooling liquid in the water inlet pipe 40 to re-enter the chamber 141. After the main steam valve is fully opened, the electric push rod 20 drives the bulging portion 22 to move to the position of the first through hole through the fixed rod, preventing the liquid in the chamber 141 from flowing into the driving cavity through the first through hole 142, ensuring that the main steam valve can be opened and guaranteeing the safe operation of the system. If the liquid in the chamber 141 flows into the driving cavity through the first through hole 142, it will change the pressure in the driving cavity, cause unnecessary movement of components such as the piston 30 connected to the driving cavity, affect the stability of the main steam valve opening, and further affect the stability of the steam flow. The cooling liquid continuously flows into the driving cavity to maintain the normal operation state of the system and prepare for the next closing operation of the main steam valve.

[0033] In one embodiment, a water outlet pipe 50 is communicatively provided on one side of the flow cavity, and the cooling liquid in the flow cavity can flow out of the valve body assembly through the water outlet pipe 50.

[0034] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them.

Claims

1. Main steam valve of steam turbine, characterized in that, Including: A valve body assembly, the valve body assembly includes a valve housing (10), a connecting pipe (11) and an adjusting pipe (13) connected in sequence. A fixing plate (12) is arranged in the connecting pipe (11). An air inlet pipe (101) is communicated and arranged on one side of the valve housing (10). A sealing member is arranged in the adjusting pipe (13). The bottom of the sealing member penetrates through the fixing plate (12) and extends to the outside of the fixing plate (12). A valve seat (16) is arranged at the connection between the connecting pipe (11) and the adjusting pipe (13). An air outlet pipe (15) is arranged on the side wall of the connecting pipe (11) and between the fixing plate (12) and the valve seat (16); A partition plate (14) is arranged in the adjusting pipe (13) and above the sealing member. The partition plate (14) divides the adjusting pipe (13) into a flow cavity and a driving cavity from top to bottom in sequence. A cavity (141) is opened in the partition plate (14). A through hole two (143) for communicating the cavity (141) with the flow cavity is opened at the top of the partition plate (14). A through hole one (142) for communicating the cavity (141) with the driving cavity is opened at the bottom of the partition plate (14); A driving member is arranged on the adjusting pipe (13); Wherein, when the driving member is started, the through hole two (143) is controlled to be closed and the through hole one (142) is opened, so that the liquid in the cavity (141) enters the driving cavity through the through hole one (142), and the sealing member is driven to move downward into the valve seat.

2. The main steam valve of a steam turbine according to claim 1, characterized in that: The driving member includes an electric push rod (20), a fixing rod (21) arranged at the output end of the electric push rod (20), and a bulging part (22) arranged on the fixing rod (21). The bulging part (22) is adapted to the through hole one (142) and the through hole two (143). The height of the cavity (141) is greater than the height of the bulging part (22).

3. The main steam valve of a steam turbine according to claim 2, characterized in that: The sealing member includes a piston (30) movably arranged in the adjusting pipe (13) and a valve rod (31) fixedly arranged at the bottom of the piston (30). The valve rod (31) penetrates through the fixing plate (12) and extends to the outside of the fixing plate (12). One end of the valve rod (31) extending to the outside of the fixing plate (12) is fixedly connected with a valve core (33) adapted to the valve seat (16). A first spring (32) is wound around a section of the surface of the valve rod (31) above the fixing plate (12).

4. The main steam valve of a steam turbine according to claim 1, characterized in that: A water inlet pipe (40) communicating with the cavity (141) is opened on the side wall of the adjusting pipe 13. The bottom of the water inlet pipe (40) extends and is provided with an adjusting member (60). The bottom of the adjusting member (60) is communicated with the driving cavity through a communicating pipe (63).

5. The main steam valve of a steam turbine according to claim 4, characterized in that: The adjusting member (60) includes an installation pipe (64) arranged at the bottom of the water inlet pipe (40) and a sealing plug (61) movably arranged in the installation pipe (64) and adapted to the water inlet pipe (40). A second spring (62) is arranged between the bottom of the sealing plug (61) and the inner wall bottom of the installation pipe (64).

6. The main steam valve of a steam turbine according to claim 5, characterized in that: One side of the flow cavity is communicated with a water outlet pipe (50).

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