Turbine speed regulation valve hydraulic servo-motor servo mechanism oil inlet stop valve leakproofness online discrimination method

Abstract

The invention belongs to the technical field of generator sets, and relates to a steam turbine speed regulation valve hydraulic servo-motor servo mechanism oil inlet stop valve leakproofness online judgment method. After the oil inlet stop valve of the high-pressure control valve of the servo mechanism is closed, an operator verifies the tightness of the valve, sets an instruction value of the high-pressure control valve controlled by the servo mechanism to be 10%, pulls the valve forcibly, and checks whether the stroke feedback of the high-pressure control valve is changed or not; if the stroke feedback does not change, the command set value of the high-pressure control valve controlled by the servo mechanism is increased by 10% for forced valve pulling, and if the stroke feedback of the high-pressure control valve does not change, the oil inlet stop valve is tight; if the high-pressure control valve has a stroke action, the oil inlet stop valve on the servo mechanism is not tight, and internal leakage exists. According to the steam turbine speed regulation valve hydraulic servo-motor servo mechanism oil inlet stop valve leakproofness online judgment method, whether the oil inlet stop valve is closed tightly or not can be effectively judged before online cleaning and checking are conducted and parts are replaced, and it is guaranteed that the operation is conducted safely and smoothly.

Description

Technical Field

[0001] The present invention belongs to the technical field of generator sets, and more specifically, relates to a turbine speed regulating valve oil motor servo mechanism. The present invention also relates to an online tightness determination method for an oil inlet stop valve of a turbine speed regulating valve oil motor servo mechanism. Background Art

[0002] The turbine speed regulating valve oil motor servo mechanism is an executive device that controls the opening, closing and stroke adjustment of the turbine speed regulating valve of the generator set. The accuracy and sensitivity of the device in executing system instructions directly determine the safety and efficiency of the unit. It is mainly composed of servo valves, unloading valves, high-pressure fire-resistant oil (EH oil), filters, valves, pipelines, etc. With the advancement of science and technology, the device has achieved miniaturization and modularization. Because the device works in a harsh environment of high temperature and high pressure and is adjusted frequently, the oil quality is easy to deteriorate. At the same time, because the processing of each set is very precise and the oil flow channels between them are small, it is very easy to get stuck. Once a component is stuck or damaged, the oil inlet valve of the device must be closed for online cleaning or replacement. However, the oil inlet stop valve of the device is expensive and can only be replaced when the machine is shut down. It is flushed by high-pressure oil for a long time and cannot guarantee that it can be tightly closed every time. The pressure gauge and oil drain valve cannot be installed on the module of the device, and the operator cannot judge whether the oil inlet stop valve of the device is tightly closed. Since the pressure of the EH oil in the device is as high as more than ten MPa and it is corrosive, and the device is installed in a small space, once the EH oil leaks, the operator cannot avoid it in time. In the past, when the maintenance personnel cleaned, inspected, and replaced the device online, they could only slightly loosen the fixing screws diagonally to observe whether there was excess oil flowing out of the module joint surface. If there was excess oil flowing out, then observe whether the pressure had a trend of gradually decreasing. The observation time was generally about 2 minutes. If there was no excess oil flowing out of the joint surface, one of the other diagonal fixing screws could be slightly loosened to observe the residual oil outflow. The oil outflow should be without pressure and have a trend of gradually decreasing. The observation time was generally about 2 minutes, and then the disassembly could be carried out after the residual oil had flowed out. When loosening any fixing screw of the module, if there is no trend of decreasing oil outflow or there is pressure, the loose fixing screws should be tightened quickly and the maintenance work should be stopped. This method often causes the module sealing ring to be distorted or the sprayed oil to splash everywhere, and it is impossible to re-tighten the screws, so the generator set can only be shut down for fault elimination. In recent years, many such accidents have occurred in various power plants.

[0003] The utility model patent "A Servo Module for Steam Turbine Speed ​​Control Oil System" with publication number CN215633171U discloses a servo module for steam turbine speed control oil system, which relates to the field of steam turbines. The utility model includes an oil motor unit, an oil inlet pipeline, an oil return pipeline, a filter element, and also includes a dual servo valve switching unit composed of two parallel servo valves, and an intelligent control system. The intelligent control system includes a background, a buzzer alarm, a wireless communication module, and an oil leakage detector. The oil leakage detector is also connected to a buzzer alarm. The background controls the switching of the dual servo valves. The utility model can detect the oil leakage of the servo valve and send it to the background. The background controls the electromagnetic valve to be energized or de-energized through control logic, and automatically switches the oil circuit to realize intelligent operation. The utility model is simple to operate and practical in function, and is very worthy of promotion. The servo module of the steam turbine speed control oil system designed in this design has the function of online detection of the oil leakage of the servo valve. When the oil leakage of the servo valve exceeds the normal oil leakage, it can alarm and switch between servo valves.

[0004] The invention patent "A Redundant Servo Control System and Method Supporting Online Replacement" with publication number CN113431820A relates to a redundant servo control system and method supporting online replacement, including: a main module and a standby module respectively connected to multiple acquisition channels; the standby module receives feedback signals and obtains the processing results of the standby module, obtains the status of each MCU in the standby module and the status of the hardware corresponding to the standby module and transmits them to the main module; the main module receives feedback signals to obtain the processing results of the main module, and transmits the processing results of the main module to the servo valve; obtains the status of each MCU in the main module and the status of the hardware corresponding to the main module, and determines the main MCU in the main module according to the voting logic architecture based on the status of each MCU in the main module; the main MCU controls the disconnection of the main module and the connection of the standby module to the servo valve according to the switching logic according to the status of the MCU in the main module and the hardware status corresponding to the main module and the hardware status corresponding to the standby module. The servo control system of this design has a redundant configuration, and two control modules and two servo valves are configured in the system, which can perform cross-matching work. When one control module or one servo valve fails, it can switch to another control module or another servo valve. No online disassembly replacement of the servo valve is performed, only online switching between the main and auxiliary servo valves is performed. Summary of the invention

[0005] The technical problem to be solved by the present invention is: in view of the deficiencies in the prior art, a method is provided for online determination of the tightness of the oil inlet stop valve of the speed regulating valve oil motor servo mechanism of a steam turbine generator set, which has simple steps and is convenient for judging the tightness of system isolation when the components of the speed regulating valve oil motor servo mechanism are cleaned, inspected and replaced online during the operation of the steam turbine generator set, so as to prevent the control oil from spraying out during the online cleaning, inspection and replacement of the servo mechanism components due to the oil inlet stop valve of the oil motor servo mechanism not being closed tightly, thereby injuring the operating personnel, polluting the environment and forcing the generator set to be shut down for leak repair.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: The present invention is an online determination method for the tightness of an oil inlet stop valve of a steam turbine speed regulating valve oil motor servo mechanism. The determination steps of the online determination method for the tightness of an oil inlet stop valve of a steam turbine speed regulating valve oil motor servo mechanism are as follows: S1: When a generator set needs to clean, inspect or replace a speed regulating valve oil motor servo mechanism component online, the operator performs a single-point cutoff of the high-voltage regulating valve command GVSPO value controlled by the servo mechanism on the VCC screen of the DEH system (steam turbine digital electro-hydraulic control system) of the generator set to confirm that the high-voltage regulating valve command GVSPO value is in an open-loop state and is not controlled by the servo system target value; S2: After the single point is cut off, it is slowly set to 0 (the amplitude is 1 or 2), forcing the servo mechanism oil motor signal to zero; it should not be set too quickly to prevent other normal high-pressure regulating valves from not being able to track and adjust in time, causing large fluctuations in the unit load; S3: After the operator forces the oil motor signal to zero, the operator closes the oil inlet stop valve on the oil motor; S4: After the oil inlet stop valve of the high-pressure regulating valve of the servo mechanism is closed, the operator verifies the tightness of the valve, sets the high-pressure regulating valve command controlled by the servo mechanism to 10% to force the valve to be pulled, and checks whether the stroke feedback of the high-pressure regulating valve changes. If there is no change, increase the high-pressure regulating valve command value controlled by the servo mechanism by 10% to force the valve to be pulled. If the stroke feedback of the high-pressure regulating valve has not changed, it means that the oil inlet stop valve is tight; if the high-pressure regulating valve has a stroke movement, it means that the oil inlet stop valve on the servo mechanism is not tight and there is internal leakage.

[0007] After the oil inlet stop valve of the high-pressure regulating valve of the servo mechanism is closed, the operator verifies the tightness of the valve. Alternatively, the operator uses a hand operator to connect the aviation plug of the high-pressure regulating valve controlled by the servo mechanism on site and manually pulls the valve twice on site.

[0008] Observe whether the high-pressure throttle valve has any stroke movement, and determine whether the oil inlet stop valve on the servo mechanism is tight. If the stroke feedback of the high-pressure throttle valve has not changed, it means that the oil inlet stop valve is tight; if the high-pressure throttle valve has stroke movement, it means that the oil inlet stop valve on the servo mechanism is not tight and there is internal leakage.

[0009] After the operator closes the oil inlet stop valve on the oil motor, he confirms that the oil inlet stop valve is fully closed.

[0010] The present invention also relates to a steam turbine speed regulating valve oil motor servo mechanism, wherein a high-pressure regulating valve is connected to one end of a telescopic rod, a piston at the other end of the telescopic rod is located in an oil cylinder, a first cavity at the upper part of the piston is connected to a servo valve through a first pipeline, a second cavity at the lower part of the piston is connected to the servo valve through a second pipeline, a servo mechanism oil inlet stop valve is arranged on the high-pressure oil supply pipeline, the high-pressure oil supply pipeline is connected to the oil inlet of the servo valve, the oil outlet of the servo valve is connected to the first pipeline and the second pipeline, a linear variable differential transformer (LVDT) is connected to the servo valve, and the linear variable differential transformer is close to the telescopic rod at the same time.

[0011] The turbine speed regulating valve oil motor servo mechanism also includes an oil leakage component. The first cavity is connected to the oil leakage component through a third pipeline, and the second cavity is connected to the oil leakage component through a fourth pipeline.

[0012] A first oil leakage channel and a second oil leakage channel are arranged in the oil leakage component. The first oil leakage channel is communicated with the third pipeline, and the second oil leakage channel is communicated with the fourth pipeline.

[0013] A first oil drain valve and a second oil drain valve are arranged in the oil drain component. The first oil drain valve is located in the first oil drain channel, and the second oil drain valve is located in the second oil drain channel.

[0014] The first oil drain channel and the second oil drain channel are connected to the oil drain main pipe.

[0015] The first oil drain valve and the second oil drain valve respectively include an oil drain valve body and a spring.

[0016] The technical solution of the present invention is adopted, and the working principle and beneficial effects are as follows: The key improvement of the online judgment method for the tightness of the oil inlet stop valve of the servo mechanism of the steam turbine speed regulating valve oil motor described in the present invention is that after closing the oil inlet stop valve of the servo module of the steam turbine speed regulating oil system, an electrical signal is given to the servo valve, and the tightness of the oil inlet stop valve of the servo module is judged by the change of the steam turbine speed regulating valve stroke. He judges the oil leakage of the servo valve through the oil leakage detector, and I judge whether the oil inlet stop valve of the servo module is closed tightly by the change of the steam turbine speed regulating valve stroke. Prevent the leakage of high-pressure control oil when disassembling the servo module components, which will harm the maintenance personnel, pollute the environment and force the shutdown accident. The online judgment method for the tightness of the oil inlet stop valve of the servo mechanism of the steam turbine speed regulating valve oil motor of the present invention can effectively judge whether the oil inlet stop valve is closed tightly before the online cleaning, inspection and replacement of components of the servo mechanism of the steam turbine speed regulating valve oil motor. It ensures the safe and smooth progress of the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The following is a brief description of the contents and symbols in the drawings of this specification: Figure 1 It is a structural schematic diagram of the turbine speed regulating valve oil motor servo mechanism of the present invention; The marks in the attached drawings are: 1. high-pressure regulating valve; 2. telescopic rod; 3. piston; 4. oil cylinder; 5. first cavity; 6. first pipeline; 7. servo valve; 8. second cavity; 9. second pipeline; 10. pressurized oil return mother pipe; 11. high-pressure oil supply pipeline; 12. servo mechanism oil inlet stop valve; 13. linear variable differential transformer; 14. oil leakage component; 15. third pipeline; 16. fourth pipeline; 17. first oil leakage channel; 18. second oil leakage channel; 19. first oil leakage valve; 20. second oil leakage valve; 21. oil leakage valve body; 22. spring; 23. servo amplifier; 24. filter; 25. oil leakage mother pipe. DETAILED DESCRIPTION

[0018] The following is a further detailed description of the specific implementation of the present invention, such as the shape, structure, mutual position and connection relationship between the various components involved, the function and working principle of each part, etc., through the description of the embodiments with reference to the accompanying drawings: As attached Figure 1 As shown, the present invention is an online determination method for the tightness of the oil inlet stop valve of the servo mechanism of the steam turbine speed regulating valve oil motor, and the determination steps of the online determination method for the tightness of the oil inlet stop valve of the servo mechanism of the steam turbine speed regulating valve oil motor are as follows: S1: When a generator set needs to clean, inspect or replace a speed regulating valve oil motor servo mechanism component online, the operator shall perform a single-point cut-off of the high-pressure regulating valve command GVSPO (GovernorValve, high-pressure regulating valve control command) value controlled by the servo mechanism on the VCC (Valve Control, turbine valve control) screen of the DEH system (steam turbine digital electro-hydraulic control system) of the generator set to confirm that the high-pressure regulating valve command GVSPO value is in an open-loop state and is not controlled by the servo system target value; S2: After the single-point cut-off, the setting value is adjusted from the range of 1 to 2 to 0, and the servo mechanism oil motor signal is forced to zero; the setting value should not be too fast to prevent other normal high-pressure regulating valves from not having time to track and adjust, causing large fluctuations in the unit load; S3: The operator forces the oil motor signal to After zero, the operator closes the oil inlet stop valve on the oil motor; S4: After the oil inlet stop valve of the high-pressure regulating valve of the servo mechanism is closed, the operator verifies the tightness of the valve, sets the high-pressure regulating valve command controlled by the servo mechanism to 10% to force the valve to be pulled, and checks whether the high-pressure regulating valve stroke feedback has changed. If there is no change, the high-pressure regulating valve command value controlled by the servo mechanism is increased by 10% to force the valve to be pulled. If the high-pressure regulating valve stroke feedback has not changed, it means that the oil inlet stop valve is tight; if the high-pressure regulating valve has a stroke action, it means that the oil inlet stop valve on the servo mechanism is not tight and has internal leakage. The above structure proposes an improved technical solution to address the deficiencies in the prior art. The key improvement of the present invention is that after closing the oil inlet stop valve of the servo module of the turbine speed regulating oil system, an electrical signal is given to the servo valve, and the tightness of the oil inlet stop valve of the servo module is judged by the change of the turbine speed regulating valve stroke. He judges the oil leakage of the servo valve by the oil leakage detector, and I judge whether the oil inlet stop valve of the servo module is closed tightly by the change of the turbine speed regulating valve stroke. Prevent high-pressure control oil from leaking when disassembling servo module components, which may harm maintenance personnel, pollute the environment, and cause forced shutdown accidents. The online judgment method for the tightness of the oil inlet stop valve of the steam turbine speed regulating valve oil motor servo mechanism of the present invention, after the technical solution is proposed, has been verified by multiple field tests, and can effectively judge whether the oil inlet stop valve is tightly closed before the steam turbine speed regulating valve oil motor servo mechanism is online cleaned, inspected, and replaced. The safe and smooth progress of the operation is guaranteed. The online judgment method for the tightness of the oil inlet stop valve of the steam turbine speed regulating valve oil motor servo mechanism of the present invention has simple steps, which is convenient for judging the tightness of system isolation when the components of each speed regulating valve oil motor servo mechanism are online cleaned, inspected, and replaced during the operation of the steam turbine generator set, and prevents the oil inlet stop valve of the oil motor servo mechanism from being closed tightly, causing the control oil to spray out when the servo mechanism components are online cleaned, inspected, and replaced, which may harm the operator, pollute the environment, and cause the generator set to be forced to shut down for leakage plugging.

[0019] The method for online judging the tightness of the oil inlet stop valve of the turbine speed regulating valve oil motor servo mechanism of the present invention is that after the oil inlet stop valve of the high-pressure regulating valve of the servo mechanism is closed, the operator verifies the tightness of the valve, or as another embodiment, the operator uses a hand operator on site to connect the aviation plug of the high-pressure regulating valve controlled by the servo mechanism and manually pulls the valve twice on site.

[0020] Observe whether the high-pressure regulating valve has any stroke action to determine whether the oil inlet stop valve on the servo mechanism is tight. If the high-pressure regulating valve stroke feedback has not changed, it means that the oil inlet stop valve is tight; if the high-pressure regulating valve has a stroke action, it means that the oil inlet stop valve on the servo mechanism is not tight and has internal leakage. The above steps can reliably perform online judgment on the tightness of the oil inlet stop valve.

[0021] After the operator closes the oil inlet stop valve on the oil motor, confirm that the oil inlet stop valve is fully closed. In the above steps, after closing the oil inlet stop valve, further confirmation is required.

[0022] The present invention also relates to a steam turbine speed regulating valve oil motor servo mechanism, wherein a high-pressure regulating valve 1 is connected to one end of a telescopic rod 2, a piston 3 at the other end of the telescopic rod 2 is located in an oil cylinder 4, a first cavity 5 on the upper part of the piston 3 is connected to a servo valve 7 through a first pipeline 6, a second cavity 8 on the lower part of the piston 3 is connected to the servo valve 7 through a second pipeline 9, a high-pressure oil supply pipeline 11 is provided with a servo mechanism oil inlet stop valve 12, the high-pressure oil supply pipeline 11 is connected to the oil inlet of the servo valve 7, an oil outlet of the servo valve 7 is connected to the first pipeline 6 and the second pipeline 9, a linear variable differential transformer 13 is connected to the servo valve 7, and the linear variable differential transformer 13 is close to the telescopic rod 2 at the same time. The steam turbine speed regulating valve oil motor servo mechanism also includes an oil leakage component 14, the first cavity 5 is connected to the oil leakage component 14 through a third pipeline 15, and the second cavity 8 is connected to the oil leakage component 14 through a fourth pipeline 16. The oil leakage component 14 is provided with a first oil leakage channel 17 and a second oil leakage channel 18, the first oil leakage channel 17 is connected to the third pipeline 15, and the second oil leakage channel 18 is connected to the fourth pipeline 16. The oil leakage component 14 is provided with a first oil leakage valve 19 and a second oil leakage valve 20, the first oil leakage valve 19 is located in the first oil leakage channel 17, and the second oil leakage valve 20 is located in the second oil leakage channel 18. The first oil leakage channel 17 and the second oil leakage channel 18 are connected to the oil leakage main pipe 20. The first oil leakage valve 19 and the second oil leakage valve 20 respectively include an oil leakage valve body 21 and a spring 22. In the above structure, when it is necessary to control the high-pressure regulating valve 1 to move upward, the servo valve is controlled to supply oil to the second cavity, and the second cavity is pushed to move upward after the oil enters the second cavity, and the telescopic rod drives the high-pressure regulating valve 1 to move upward to achieve adjustment. At this time, the first cavity is synchronously limited to drain oil.

[0023] When it is necessary to control the high-pressure regulating valve 1 to move downward, the servo valve is controlled to supply oil to the first cavity. After the first cavity enters the oil, the piston is pushed downward, and the telescopic rod drives the high-pressure regulating valve 1 downward to achieve adjustment. At this time, the second cavity is synchronously limited to limit oil leakage. The control of the high-pressure regulating valve 1 is effectively completed.

[0024] The key improvement of the online judgment method for the tightness of the oil inlet stop valve of the servo mechanism of the steam turbine speed regulating valve oil motor described in the present invention is that after closing the oil inlet stop valve of the servo module of the steam turbine speed regulating oil system, an electrical signal is given to the servo valve, and the tightness of the oil inlet stop valve of the servo module is judged by the change of the steam turbine speed regulating valve stroke. He judges the oil leakage of the servo valve through the oil leakage detector, and I judge whether the oil inlet stop valve of the servo module is closed tightly by the change of the steam turbine speed regulating valve stroke. Prevent the leakage of high-pressure control oil when disassembling the servo module components, which will harm the maintenance personnel, pollute the environment and force the shutdown accident. The online judgment method for the tightness of the oil inlet stop valve of the servo mechanism of the steam turbine speed regulating valve oil motor of the present invention can effectively judge whether the oil inlet stop valve is closed tightly before the online cleaning, inspection and replacement of components of the servo mechanism of the steam turbine speed regulating valve oil motor. It ensures the safe and smooth progress of the operation.

[0025] The present invention is described exemplarily above in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A method for online determination of the tightness of the oil inlet stop valve of a steam turbine speed regulating valve oil motor servo mechanism, characterized in that: The steps of the online determination method for the tightness of the oil inlet stop valve of the steam turbine speed regulating valve oil motor servo mechanism are as follows: S1: When a generator set needs to clean, inspect or replace a speed regulating valve oil motor servo mechanism component online, the operator performs a single-point cutoff of the high-voltage regulating valve command GVSPO value controlled by the servo mechanism on the VCC screen of the DEH system of the generator set to confirm that the high-voltage regulating valve command GVSPO value is in an open-loop state and is not controlled by the servo system target value; S2: After the single point is cut off, the value is slowly set to 0, forcing the servo mechanism oil motor signal to zero; it should not be set too quickly to prevent other normal high-pressure regulating valves from not being able to track and adjust in time, causing large fluctuations in the unit load; S3: After the operator forces the oil motor signal to zero, the operator closes the oil inlet stop valve on the oil motor; S4: After the oil inlet stop valve of the high-pressure regulating valve of the servo mechanism is closed, the operator verifies the tightness of the valve, sets the high-pressure regulating valve command controlled by the servo mechanism to 10% to force the valve to be pulled, and checks whether the stroke feedback of the high-pressure regulating valve changes. If there is no change, the high-pressure regulating valve command value controlled by the servo mechanism is increased by 10% to force the valve to be pulled. If the stroke feedback of the high-pressure regulating valve has not changed, it means that the oil inlet stop valve is tight; if the high-pressure regulating valve has a stroke movement, it means that the oil inlet stop valve on the servo mechanism is not tight and there is internal leakage.

2. The method for determining the tightness of the oil inlet stop valve of the steam turbine speed regulating valve oil motor servo mechanism according to claim 1 is characterized in that: After the oil inlet stop valve of the high-pressure regulating valve of the servo mechanism is closed, the operator verifies the tightness of the valve. Alternatively, the operator uses a hand operator to connect the aviation plug of the high-pressure regulating valve controlled by the servo mechanism on site, manually pulls the valve twice on site, and observes whether the high-pressure regulating valve has any stroke movement to determine whether the oil inlet stop valve on the servo mechanism is tight.

3. The method for determining the tightness of the oil inlet stop valve of the steam turbine speed regulating valve oil motor servo mechanism according to claim 2 is characterized in that: Observe whether the high-pressure throttle valve has any stroke movement, and determine whether the oil inlet stop valve on the servo mechanism is tight. If the stroke feedback of the high-pressure throttle valve has not changed, it means that the oil inlet stop valve is tight; if the high-pressure throttle valve has stroke movement, it means that the oil inlet stop valve on the servo mechanism is not tight and there is internal leakage.

4. The method for determining the tightness of the oil inlet stop valve of the steam turbine speed regulating valve oil motor servo mechanism according to claim 3 is characterized in that: After the operator closes the oil inlet stop valve on the oil motor, he confirms that the oil inlet stop valve is fully closed.

5. A steam turbine speed regulating valve oil motor servo mechanism, characterized in that: The high-pressure regulating valve (1) is connected to one end of the telescopic rod (2), the piston (3) at the other end of the telescopic rod (2) is located in the oil cylinder (4), the first cavity (5) above the piston (3) is connected to the servo valve (7) through the first pipeline (6), the second cavity (8) below the piston (3) is connected to the servo valve (7) through the second pipeline (9), the high-pressure oil supply pipeline (11) is provided with a servo mechanism oil inlet stop valve (12), the high-pressure oil supply pipeline (11) is connected to the oil inlet of the servo valve (7), the oil outlet of the servo valve (7) is connected to the first pipeline (6) and the second pipeline (9), the linear variable differential transformer (13) is connected to the servo valve (7), and the linear variable differential transformer (13) is close to the telescopic rod (2).

6. The turbine speed regulating valve oil motor servo mechanism according to claim 5, characterized in that: The turbine speed regulating valve oil motor servo mechanism also includes an oil leakage component (14), the first cavity (5) is connected to the oil leakage component (14) through a third pipeline (15), and the second cavity (8) is connected to the oil leakage component (14) through a fourth pipeline (16).

7. The method for online judging the tightness of the oil inlet stop valve of the steam turbine speed regulating valve oil motor servo mechanism according to claim 5 or 6, characterized in that: A first oil leakage channel (17) and a second oil leakage channel (18) are arranged in the oil leakage component (14); the first oil leakage channel (17) is connected to the third pipeline (15), and the second oil leakage channel (18) is connected to the fourth pipeline (16).

8. The method for online judging the tightness of the oil inlet stop valve of the steam turbine speed regulating valve oil motor servo mechanism according to claim 7 is characterized in that: A first oil drain valve (19) and a second oil drain valve (20) are arranged in the oil drain component (14); the first oil drain valve (19) is located in the first oil drain channel (17), and the second oil drain valve (20) is located in the second oil drain channel (18).

9. The turbine speed regulating valve oil motor servo mechanism according to claim 8, characterized in that: The first oil leakage passage (17) and the second oil leakage passage (18) are connected to the oil leakage main pipe (20).

10. The turbine speed regulating valve oil motor servo mechanism according to claim 9, characterized in that: The first oil drain valve (19) and the second oil drain valve (20) respectively comprise an oil drain valve body (21) and a spring (22).

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