A steam turbine emergency shutdown system

Abstract

This invention discloses a steam turbine emergency shutdown system, comprising: a condition monitoring module that monitors the condition of the steam turbine main shaft in real time; an opening / closing module installed in each of the condition monitoring modules and electrically connected to the condition monitoring modules; and at least one emergency shutdown device connected to the opening / closing module. The emergency shutdown device receives the opening degree signal sent by the opening / closing module and controls the steam turbine's inlet valve or speed regulating valve according to the opening degree signal. This invention installs steam turbine condition monitoring devices at both ends of the steam turbine main shaft. A controller embedded within the steam turbine condition monitoring device is linked to the emergency shutdown device. The steam turbine condition monitoring device activates different emergency shutdown devices according to different conditions, allowing either the emergency shutdown device controlling the inlet valve or the emergency shutdown device controlling the speed regulating valve to be activated, achieving the purpose of rapid steam turbine shutdown or rapid speed reduction.

Description

Technical Field

[0001] This invention relates to the field of steam turbine technology, and in particular to a steam turbine emergency shutdown system. Background Technology

[0002] A steam turbine is a rotary steam power unit. High-temperature, high-pressure steam passes through a fixed nozzle, becomes an accelerated airflow, and is then injected onto the blades, causing the rotor, which is equipped with rows of blades, to rotate and perform work. In actual use, when the turbine rotor overspeeds, the turbine thrust shaft wears, or the turbine rotor vibration exceeds a certain threshold, the emergency shutdown system must be used to close the turbine's inlet valve or speed regulating valve.

[0003] The existing turbine emergency shutdown system mainly consists of a diaphragm valve, emergency shutdown block, OPC solenoid valve, AST solenoid valve, air pilot valve, emergency shutdown device, emergency shutdown device slide valve, and a safety control device for remote reset. Currently, when the turbine experiences overspeed, thrust shaft wear, rotor vibration, or other similar issues, the status data is first sent to the central control room. The central control room processes the data before issuing a command to the turbine emergency shutdown system, at which point the system can close the inlet valve or speed control valve. Therefore, the existing system cannot immediately activate the turbine emergency shutdown system when a problem occurs, hindering rapid shutdown and speed reduction, which ultimately affects the turbine's service life. Summary of the Invention

[0004] This invention provides a steam turbine emergency shutdown system. Steam turbine condition monitoring devices are installed at both ends of the steam turbine main shaft. A controller embedded in the steam turbine condition monitoring device is linked with an emergency shutdown device. The steam turbine condition monitoring device activates different emergency shutdown devices according to different conditions, allowing either the emergency shutdown device controlling the steam inlet valve or the emergency shutdown device controlling the speed regulating valve to be activated, thereby achieving the purpose of rapid shutdown or rapid deceleration of the steam turbine.

[0005] This invention is achieved using the following technical solution:

[0006] A steam turbine emergency shutdown system includes:

[0007] A condition monitoring module that monitors the condition of the turbine main shaft in real time;

[0008] An on / off module is installed in each of the condition monitoring modules, and the on / off module is electrically connected to the condition monitoring module.

[0009] At least one emergency shut-off device is provided, which is connected to the opening and closing module. The emergency shut-off device receives the opening degree signal sent by the opening and closing module and controls the turbine's intake valve or speed regulating valve according to the opening degree signal.

[0010] A further improvement of the present invention is that the emergency trip device is two, including: a first emergency trip device disposed at one end of the turbine main shaft and a second emergency trip device disposed at the other end of the turbine main shaft.

[0011] A further improvement of the present invention is that the condition monitoring module includes: a first turbine condition monitoring ring located between the first emergency shut-off device and the main turbine impeller, and a second turbine condition monitoring ring located between the second emergency shut-off device and the largest turbine impeller;

[0012] Both the first and second turbine condition monitoring loops collect data on the turbine main shaft speed and vibration.

[0013] Both the first turbine condition monitoring ring and the second turbine condition monitoring ring are connected to the first emergency trip device and the second emergency trip device.

[0014] The first turbine condition monitoring loop selects one of the first and second emergency trip devices.

[0015] The second turbine condition monitoring loop selects one of the first and second emergency trip devices.

[0016] A further improvement of the present invention is that the opening and closing module is embedded in the inner wall of the ring body of the first steam turbine condition monitoring ring;

[0017] The opening and closing module is embedded in the inner wall of the ring body of the second turbine condition monitoring ring.

[0018] A further improvement of the present invention is that the first turbine condition monitoring ring includes a first semicircular ring, a second semicircular ring, a first set of monitoring sensors disposed inside the first semicircular ring, a second set of monitoring sensors disposed inside the second semicircular ring, a first power supply installed outside the first semicircular ring, and a second power supply installed outside the second semicircular ring.

[0019] A first power source or a second power source is connected to the opening / closing module, and the first power source or the second power source supplies power to the opening / closing module.

[0020] A further improvement of the present invention is that the semicircular ring containing the power supply that supplies power to the opening and closing module is the main semicircular ring; the semicircular ring containing the power supply that does not supply power to the opening and closing module is the secondary semicircular ring.

[0021] The monitoring sensor group on the main semicircular ring continuously monitors the condition of the turbine main shaft, while the monitoring sensor group on the auxiliary semicircular ring intermittently monitors the condition of the turbine main shaft.

[0022] A further improvement of this invention is that the data collected by the monitoring sensor on the secondary semicircular ring is used as correction data and matched with the data collected by the monitoring sensor on the main semicircular ring to ensure the monitoring accuracy of the condition monitoring module and prevent the emergency trip device from being activated erroneously.

[0023] A further improvement of the present invention is that the emergency shut-off device's hook is connected to the butterfly valve, the opening and closing module controls the operation of the emergency shut-off device, and the mechanical metal parts inside the butterfly valve are disengaged.

[0024] The hook is fixedly connected to a duckbill, which is supported on the top surface of the butterfly valve by an elastic element. A displacement acquisition module is installed on the elastic element, which is connected to the control valve. The control valve can selectively control either the steam turbine's inlet valve or the speed regulating valve.

[0025] A further improvement of this invention is that, since the speed regulating valve adjusts the main shaft speed of the turbine and the intake valve adjusts the start and stop of the main shaft, the main shaft speed of the turbine gradually decreases during the process of the main shaft rotating from a high-speed state to a closed state. When the elasticity of the elastic element is at its maximum, the speed regulating valve is adjusted accordingly. When the elasticity of the elastic element is at its intermediate value, the valve switches from the speed regulating valve to the intake valve. When the elasticity of the elastic element is at its minimum value, the intake valve is completely closed. During the process of resetting the elasticity of the elastic element, the valve switches from the intake valve to the speed regulating valve.

[0026] A further improvement of the present invention is that a limit switch is installed on the peripheral wall of the butterfly valve. The limit switch is connected to the displacement acquisition module. When the hook rotates, it drives the butterfly valve to move. The mechanical metal parts inside the butterfly valve are disengaged. When the mechanical metal parts pass the limit switch, they switch from the speed regulating valve to the intake valve. When the mechanical metal parts return to the limit switch, they switch from the intake valve to the speed regulating valve.

[0027] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0028] This invention installs turbine condition monitoring devices at both ends of the turbine main shaft. The controller embedded in the turbine condition monitoring device is linked with the emergency shut-off device. The turbine condition monitoring device activates different emergency shut-off devices according to different conditions, allowing either the emergency shut-off device controlling the steam inlet valve or the emergency shut-off device controlling the speed regulating valve to be activated, thereby achieving the purpose of rapid turbine shutdown or rapid speed reduction. Attached Figure Description

[0029] Figure 1 This is a diagram showing the condition monitoring module and emergency shutdown device of the present invention installed on the main shaft of a steam turbine;

[0030] Figure 2 This is a schematic diagram of the turbine condition monitoring loop of the present invention;

[0031] Figure 3 This is a schematic diagram illustrating the operating structure of either the intake valve or the speed regulating valve of the steam turbine according to the present invention.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1-Steam turbine main shaft; 2-First emergency trip device; 3-Second emergency trip device; 4-First steam turbine condition monitoring ring; 5-Second steam turbine condition monitoring ring; 6-Steam turbine main impeller; 7-Steam turbine maximum impeller; 8-First semi-circular ring; 9-First set of monitoring sensors; 10-Second semi-circular ring; 11-Second set of monitoring sensors; 12-First power supply; 13-Second power supply; 14-Hook; 15-Butterfly valve; 16-Mechanical metal part; 17-Duckbill; 18-Elastic element; 19-Displacement acquisition module; 20-Limit switch. Detailed Implementation

[0034] The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings. However, it should be noted that these embodiments are not intended to limit the present invention. Equivalent changes or substitutions in function, method, or structure made by those skilled in the art based on these embodiments are all within the scope of protection of the present invention.

[0035] In the description of this embodiment, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the invention.

[0036] Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0037] The terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art will understand the specific meaning of these terms in this invention based on the specific circumstances.

[0038] Referring to the accompanying drawings, this embodiment of the invention provides a turbine emergency shutdown system, including a condition monitoring module, an opening and closing module installed in each condition monitoring module, and at least one emergency shutdown device. The condition monitoring module monitors the condition of the turbine main shaft 1 in real time; the opening and closing module is electrically connected to the condition monitoring module; the emergency shutdown device is connected to the opening and closing module, and receives the opening degree signal sent by the opening and closing module. The emergency shutdown device controls the turbine's intake valve or speed regulating valve according to the opening degree signal.

[0039] The preferred emergency trip device consists of two devices: a first emergency trip device 2 located at one end of the turbine main shaft 1 and a second emergency trip device 3 located at the other end of the turbine main shaft 1. The condition monitoring module includes a first turbine condition monitoring ring 4 located between the first emergency trip device 2 and the turbine main impeller 6, and a second turbine condition monitoring ring 5 located between the second emergency trip device 3 and the turbine maximum impeller 7. Both the first turbine condition monitoring ring 4 and the second turbine condition monitoring ring 5 collect data on the rotational speed and vibration of the turbine main shaft 1. Both the first turbine condition monitoring ring 4 and the second turbine condition monitoring ring 5 are connected to the first emergency trip device 2 and the second emergency trip device 3. The first turbine condition monitoring ring 4 can selectively control either the first emergency trip device 2 or the second emergency trip device 3. The second turbine condition monitoring ring 5 can selectively control either the first emergency trip device 2 or the second emergency trip device 3.

[0040] It should be noted that the emergency trip device in this embodiment of the invention is installed on the extension shaft of the turbine main shaft. The emergency trip device includes a flyweight sensor installed on the extension shaft and a compression spring for controlling the action of the flyweight sensor. The center of gravity of the flyweight sensor is offset from the geometric center of the turbine main shaft. The compression spring presses the flyweight into a transverse hole. At a certain rotational speed, the turbine main shaft experiences centrifugal force on the flyweight. The constraint force f of the spring is opposite in direction to the centrifugal force FL experienced by the flyweight, and the flyweight flies out when its magnitude is exactly equal to FL. When the centrifugal force FL > f, the flyweight moves outward, the eccentricity increases, and the rate of increase of the centrifugal force exceeds the rate of increase of the constraint force, causing the flyweight to strike rapidly. The emergency trip device has a hook 14 outside the extension shaft, and a butterfly valve 15 is connected to the lower part of the hook 14 to control the oil pressure. When the fly hammer strikes the hook 14, the hook 14 rotates, causing the butterfly valve 15 to move to the right. The tripping oil leaks from the left end, causing the oil pressure in the mechanical tripping oil header to drop, forcing the turbine to slow down or stop, thus protecting the turbine.

[0041] Preferably, the inner wall of the first turbine condition monitoring ring 4 is embedded with an opening and closing module; the inner wall of the second turbine condition monitoring ring 5 is also embedded with an opening and closing module.

[0042] The preferred first turbine condition monitoring ring 4 includes a first semicircular ring 8, a second semicircular ring 10, a first set of monitoring sensors 9 disposed inside the first semicircular ring 8, a second set of monitoring sensors 11 disposed inside the second semicircular ring 10, a first power supply 12 installed outside the first semicircular ring 8, and a second power supply 13 installed outside the second semicircular ring 10; the first power supply 12 or the second power supply 13 is connected to the start-up and shut-down module, and the first power supply 12 or the second power supply 13 supplies power to the start-up and shut-down module.

[0043] Preferably, the semicircular ring containing the power supply that supplies power to the start-up and shut-down module is the main semicircular ring; the semicircular ring containing the power supply that does not supply power to the start-up and shut-down module is the auxiliary semicircular ring; the monitoring sensor group on the main semicircular ring continuously monitors the condition of the turbine main shaft 1, and the monitoring sensor group on the auxiliary semicircular ring intermittently monitors the condition of the turbine main shaft 1.

[0044] The data collected by the monitoring sensor on the secondary semicircular ring of this invention is used as correction data and matched with the data collected by the monitoring sensor on the main semicircular ring to ensure the monitoring accuracy of the condition monitoring module and prevent the emergency trip device from being activated erroneously.

[0045] The emergency trip device's hook 14 is preferably connected to the butterfly valve 15. The opening and closing module controls the emergency trip device's operation, and the butterfly valve 15 is mechanically tripped. The hook 14 is fixedly connected to a duckbill 17, which is supported on the top surface of the butterfly valve 15 by an elastic element 18. A displacement acquisition module 19 is installed on the elastic element 18, and the displacement acquisition module 19 is connected to a control valve. The control valve can selectively control either the turbine's intake valve or the speed regulating valve.

[0046] Since the speed regulating valve adjusts the main shaft speed of the turbine, and the intake valve adjusts the start and stop of the main shaft 1 of the turbine, the main shaft speed of the turbine 1 needs to be gradually reduced during the process of the main shaft 1 changing from a high-speed rotating state to a closed state. Therefore, when the elastic element 18 of the present invention has the maximum elasticity, it adjusts the speed regulating valve accordingly. When the elastic element 18 has the intermediate value, it switches from the speed regulating valve to the intake valve. When the elastic element 18 has the minimum elasticity, the intake valve is completely closed. During the process of resetting the elastic element 18, it switches from the intake valve to the speed regulating valve.

[0047] A limit switch 20 is preferably installed on the peripheral wall of the butterfly valve 15. The limit switch 20 is connected to the displacement acquisition module 19. When the hook 14 rotates, it drives the butterfly valve 15 to move. The mechanical metal part 16 inside the butterfly valve 15 is disengaged. When the mechanical metal part 16 passes the limit switch 20, it switches from the speed regulating valve to the intake valve. When the mechanical metal part 16 returns to the limit switch 20, it switches from the intake valve to the speed regulating valve.

[0048] The detailed descriptions listed above are merely specific descriptions of feasible embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

[0049] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0050] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A turbine trip system, characterized by, The utility model relates to a turbine condition monitoring system, comprising: a condition monitoring module for monitoring the condition of the turbine main shaft in real time; an on-off module installed on each condition monitoring module, which is electrically connected to the condition monitoring module; at least one emergency breaker connected to the on-off module, which receives the opening degree signal sent by the on-off module and controls the turbine's inlet valve or speed regulating valve according to the opening degree signal; the emergency breaker is two, including a first emergency breaker arranged at one end of the turbine main shaft and a second emergency breaker arranged at the other end of the turbine main shaft; the condition monitoring module includes a first turbine condition monitoring ring between the first emergency breaker and the turbine main impeller and a second turbine condition monitoring ring between the second emergency breaker and the turbine maximum impeller; the first turbine condition monitoring ring and the second turbine condition monitoring ring both collect the turbine main shaft speed and vibration condition; the first turbine condition monitoring ring and the second turbine condition monitoring ring are both connected to the first emergency breaker and the second emergency breaker; the first turbine condition monitoring ring selectively controls the first emergency breaker and the second emergency breaker; the second turbine condition monitoring ring selectively controls the first emergency breaker and the second emergency breaker; the first turbine condition monitoring ring includes a first semicircular ring, a second semicircular ring, a first group of monitoring sensors arranged on the inner side of the first semicircular ring, a second group of monitoring sensors arranged on the inner side of the second semicircular ring, a first power supply installed on the outer side of the first semicircular ring, and a second power supply installed on the outer side of the second semicircular ring; the first power supply or the second power supply is connected to the on-off module, and the first power supply or the second power supply supplies power to the on-off module.

2. A turbine trip system according to claim 1, wherein the on-off module is embedded in the inner wall of the ring body of the first turbine condition monitoring ring; the on-off module is embedded in the inner wall of the ring body of the second turbine condition monitoring ring.

3. A turbine trip system according to claim 1 wherein, the semicircular ring where the power supply for the on-off module is located is the main semicircular ring, and the semicircular ring where the power supply not for the on-off module is located is the auxiliary semicircular ring; the monitoring sensor group on the main semicircular ring continuously monitors the turbine main shaft condition, and the monitoring sensor group on the auxiliary semicircular ring intermittently monitors the turbine main shaft condition.

4. A turbine trip system according to claim 3, wherein The data collected by the monitoring sensor on the auxiliary semicircular ring is used as correction data to match the data collected by the monitoring sensor on the main semicircular ring, ensuring the monitoring accuracy of the condition monitoring module and preventing the emergency breaker from being mistakenly started.

5. A turbine trip system according to claim 1 wherein, The emergency breaker is connected to the butterfly valve, the on-off module controls the action of the emergency breaker, and the mechanical metal part in the butterfly valve is tripped; the duckbill is fixedly connected to the impact hook and supported on the top surface of the butterfly valve through the elastic member, a displacement amount collecting module is arranged on the elastic member, the displacement amount collecting module is connected to the control valve, and the control valve selectively controls the turbine's inlet valve or speed regulating valve.

6. A turbine trip system according to claim 5, wherein The elastic member is adjusted by the speed regulating valve when the elastic amount of the elastic member is maximum, the elastic member is switched from the speed regulating valve to the air inlet valve when the elastic amount of the elastic member is in the middle value, and the air inlet valve is completely closed when the elastic amount of the elastic member is minimum.

7. A turbine trip system according to claim 5, wherein The stroke switch is installed on the peripheral wall of the butterfly valve, the stroke switch is connected with the displacement acquisition module, the impact hook drives the butterfly valve to act, the mechanical metal part in the butterfly valve is tripped, and the mechanical metal part is switched from the speed regulating valve to the air inlet valve when passing through the stroke switch; the mechanical metal part is switched from the air inlet valve to the speed regulating valve when passing through the stroke switch in the return process.

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