Mechanical overspeed protection device for penstock protection valves

Abstract

The present invention discloses a mechanical overspeed protection device for a pressure steel pipe protection valve, comprising a device body, a reversing valve, a cam, a flip plate, a crank, a connecting rod, a handle shaft, and a trigger drive device. The device body is provided with a rotating shaft, the crank is connected to the rotating shaft, and one end of the crank is hinged to the connecting rod, the other end of the connecting rod is provided with a waist-shaped hole, the device body is provided with a handle shaft, and the handle shaft is connected to the waist-shaped hole of the connecting rod through a shaft, the handle shaft is provided with a trigger drive device and a cam, a reversing valve is provided above the cam, one end of the flip plate is provided in a pipeline, and the other end is connected to the rotating shaft. The mechanical overspeed protection device directly operates to control the dynamic water shutoff of the pressure steel pipe protection valve, and the trigger control is precise, the response is rapid, it is safe and reliable, and the maintenance is simple.

Description

Technical Field

[0001] The invention belongs to the field of valves, and in particular relates to a mechanical overspeed protection device used on a penstock protection valve. Background Art

[0002] Hydropower stations often require penstock protection valves on their diversion penstocks. Their primary function is to shut off the water flow when a rupture or burst occurs, preventing the accident from spreading further. Failure to close the penstock protection valve in a timely manner can lead to major accidents, such as collapse of the diversion tunnel and flooding of generator sets and powerhouses. When a rupture or burst occurs in a penstock, the flow rate of the medium within the pipe increases suddenly. Ultrasonic flowmeters were previously used to monitor flow rates, but they cannot effectively mitigate fluctuations in flow rate and uneven distribution within the pipe, making them prone to misoperation. Furthermore, ultrasonic flowmeters only generate an electrical signal and require the involvement of an electrical control system. If the electrical control system loses power, the ultrasonic flowmeter will be unable to shut off the penstock protection valve, preventing the accident from spreading further. Summary of the Invention

[0003] In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides a mechanical overspeed protection device for a pressure steel pipe protection valve. The mechanical overspeed protection device directly operates and controls the dynamic water closure of the pressure steel pipe protection valve, with precise triggering control, rapid response, safety and reliability, and simple maintenance.

[0004] To achieve the above-mentioned purpose, the present invention adopts the following technical solution: a mechanical overspeed protection device for a pressure steel pipe protection valve, comprising a device body, a reversing valve, a cam, a flip plate, a crank, a connecting rod, a handle shaft, and a trigger drive device. A rotating shaft is passed through the device body, the crank is connected to the rotating shaft, and one end of the crank is hinged to the connecting rod, and the other end of the connecting rod is provided with a waist-shaped hole. The aforementioned device body is provided with a handle shaft, and the handle shaft is connected to the waist-shaped hole of the connecting rod through an axis rod. A trigger drive device and a cam are provided on the handle shaft, and a reversing valve is provided above the cam. One end of the flip plate is arranged in the pipeline, and the other end is connected to the rotating shaft.

[0005] In the above technical solution, a box body is provided on the device body, and the trigger drive device, cam, and handle shaft are all arranged in the box body.

[0006] In the above technical solution, the trigger drive device includes a linkage sleeve, a spring seat shaft, a compression spring, a spring rod, a spring seat and a secondary shaft. The linkage sleeve is inserted into the handle shaft, the spring seat shaft is hinged to the end of the linkage sleeve, the compression spring is inserted into the spring rod, one end of the spring rod passes through the spring seat shaft, and the other end is connected to the spring seat, and the spring seat is rotatably connected to the box body.

[0007] In the above technical solution, an adjustment seat is provided between the spring rod and the spring seat.

[0008] In the above technical solution, the handle shaft and the secondary shaft are mounted on the box body via rolling bearings.

[0009] In the above technical solution, a limiting bolt is provided in the box body.

[0010] In the above technical solution, the reversing valve is connected to the hydraulic control system to control the dynamic water closure of the pressure steel pipe protection valve.

[0011] In the above technical solution, a counterweight block is provided on the crank, the counterweight block is fixed by a nut, and the position of the counterweight block is adjustable.

[0012] In the above technical solution, a reset handle is provided on the handle shaft.

[0013] In the above technical solution, a position detection switch is provided on the box body and is connected to an electrical control system to output an accident alarm signal.

[0014] The beneficial effects of the present invention are: when the flow rate of the pipeline medium exceeds the set value, the device can timely and reliably control the dynamic water closure of the pressure steel pipe protection valve, cut off the water flow, and prevent the accident from further spreading, and the above operations do not require the participation of the electrical control system; the medium response flow rate can be accurately set, and the device has a self-holding function after being triggered, which is safe, reliable and simple to maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the use of the present invention for a pressure steel pipe protection valve.

[0016] Figure 2 Schematic diagram of medium flow rate detection of the present invention.

[0017] Figure 3 This is a schematic diagram of the present invention after being triggered.

[0018] Figure 4 for Figure 2 Cross-sectional view of AA in the figure.

[0019] Figure 5 for Figure 4 Schematic diagram of BB.

[0020] Figure 6 、 7 8 are schematic diagrams of three states of the present invention.

[0021] Wherein: 1. This device, 2. Heavy hammer, 3. Relay, 4. Penstock protection valve, 5. Reversing valve, 6. Cam, 7. Device body, 8. Flip plate, 9. Crank, 10. Counterweight, 11. Box, 12. Reset handle, 13. Position detection switch, 14. Connecting rod, 15. Handle shaft, 16. Linking sleeve, 17. Spring seat shaft, 18. Compression spring, 19. Spring rod, 20. Adjustment seat, 21. Spring seat, 22. Countershaft, 23. Limit bolt. DETAILED DESCRIPTION

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0023] like Figures 1 to 3 The device, shown in FIG. 1 , is a mechanical overspeed protection device for a penstock protection valve. The device comprises a main body 7, a reversing valve 5, a cam 6, a flip plate 8, a crank 9, a connecting rod 14, a handle shaft 15, and a triggering mechanism. The main body 7 is provided with a rotating shaft, to which the crank 9 is connected. One end of the crank 9 is hingedly connected to the connecting rod 14, and the other end of the connecting rod 14 is provided with a circular hole. The main body 7 is provided with a handle shaft 15, which is connected to the circular hole in the connecting rod 14 via a shaft. The handle shaft 15 is provided with a triggering mechanism and a cam 6. The reversing valve 5 is located above the cam 6. The flip plate 8 is disposed at one end within the pipeline and at the other end connected to the rotating shaft. The crank 9 and connecting rod 14 form a crank-connecting rod mechanism. Water flow drives the flip plate 8 to move, rotating the crank, which in turn drives the connecting rod 14. This movement of the connecting rod 14 activates the triggering mechanism, which drives the handle shaft 15 to continue rotating rapidly, thereby rotating the cam 5 and operating the reversing valve 5.

[0024] When in use, the device works together with the heavy hammer 2, the relay 3 and the pressure steel pipe protection valve 4.

[0025] In the above technical solution, a box body 11 is provided on the device body 7 , and the trigger driving device, the cam 6 , and the handle shaft 15 are all arranged in the box body 11 .

[0026] like Figure 4As shown, the trigger drive device includes a linkage sleeve 16, a spring seat shaft 17, a compression spring 18, a spring rod 19, a spring seat 21, and a secondary shaft 22. The linkage sleeve 16 is mounted on the handle shaft 15. The spring seat shaft 17 is hinged to the end of the linkage sleeve 16. The compression spring 18 is mounted on the spring rod 19. One end of the spring rod 19 passes through the spring seat shaft 17 and the other end is connected to the spring seat 21. The spring seat 21 is rotatably connected to the housing 11. A linkage mechanism is also formed between the linkage sleeve 16, the spring seat shaft 17, and the spring rod 19. In a normal state, the linkage sleeve 16, the spring seat shaft 17, and the spring rod 19 are in a straight line, which is the dead point of the linkage mechanism. When the handle shaft 15 is rotated, the linkage mechanism is triggered, and the elastic force of the compression spring 18 drives the linkage sleeve 16 to rotate rapidly, causing the cam 6 to rotate and the reversing valve 5 to receive a reversing signal.

[0027] During the rapid rotation of the handle shaft 16, since the end of the connecting rod 14 is provided with a waist-shaped hole, the shaft connected to the waist-shaped hole of the connecting rod 14 will not be hindered by the connecting rod 14 during the rapid movement of the handle shaft 15, preventing the connecting rod 14 and other mechanisms from affecting the movement of the handle shaft 15, thereby reducing the sensitivity of the device.

[0028] In the above technical solution, an adjustment seat 20 is provided between the spring rod 19 and the spring seat 21. The adjustment seat 20 is connected to the spring rod 19 by a thread, and the elastic force of the compression spring 18 is changed by adjusting the position of the adjustment seat 21 to adapt to different spring force requirements.

[0029] In the above technical solution, the handle shaft 15 and the secondary shaft 22 are mounted on the box body 11 via rolling bearings.

[0030] like Figure 5 As shown, a limiting bolt 23 is provided in the housing 11. The limiting bolt 23 is used to limit the movement of the linkage sleeve 16. The linkage sleeve 16 can only move upward when subjected to the elastic force of the compression spring 18. In addition, when the reset handle 12 is reset, it is simple and convenient, without having to repeatedly search for the dead point of the trigger drive mechanism.

[0031] In the above technical solution, the reversing valve 5 is connected to the hydraulic control system to control the dynamic water closure of the pressure steel pipe protection valve 4.

[0032] In the above technical solution, a counterweight 10 is provided on the crank 9 , the counterweight 10 is fixed by a nut, and the position of the counterweight 10 is adjustable.

[0033] In the above technical solution, a reset handle 12 is provided on the handle shaft 15 .

[0034] In the above technical solution, the housing 11 is provided with a position detection switch 13, which is connected to the electrical control system and outputs an accident alarm signal. The position detection switch 13 is used to detect the position of the shaft. When the device is triggered, the handle shaft 15 drives the shaft to move significantly. The position detection switch 13 detects this movement and sends a signal to the electrical control system.

[0035] like Figure 6 、 Figure 7 and Figure 8 As shown, the device is divided into three states when in use: normal state, trigger state, and pre-reset state.

[0036] Normal state: When the medium flow rate is less than the set value, the force of the medium impacting the flip plate 8 is small and cannot overcome the torque generated by the counterweight 10, and the flip plate 8, crank 9, counterweight 10, etc. do not move.

[0037] CFD numerical simulation technology and fluid experiments are used to accurately calibrate the balancing torque of the counterweight, and fine-tuning can be performed based on the on-site medium flow conditions. This ensures that the medium flow rate response set value of the device is accurate, ensuring that the penstock protection valve can respond promptly and effectively.

[0038] Triggered state: When the medium flow rate is equal to or greater than the set value, the force exerted by the medium on the flip plate 8 overcomes the torque generated by the counterweight 10. The flip plate 8, crank 9, counterweight 10, and other components move, driving the connecting rod 14 to rotate the handle shaft 15, moving the spring rod 19 away from its dead center equilibrium position. Driven by the compression spring 18, the linkage sleeve 16 moves to the extreme position formed by the spring rod 19 and the spring seat shaft 17. The rotation of the handle shaft 15 causes the reversing valve 5 to complete the switching action, controlling the penstock protection valve 4 to close. This valve closing action is achieved by the gravitational potential energy of the weight 2. This system, without the need for electrical control system intervention, effectively and reliably shuts off the water flow, protecting the diversion penstock, hydropower station units, and powerhouse buildings. Simultaneously, the position detection switch 13 is activated, generating an alarm signal that is transmitted to the control system.

[0039] The trigger drive mechanism utilizes a compressed spring stored in the dead center of the motion mechanism. Once triggered, the spring's potential energy is released, driving the motion mechanism. The trigger mechanism is separate from the drive mechanism, and the length of the flap can be adjusted based on the pipe diameter, ensuring stable flow of the pipeline medium. The force exerted by the medium on the flap is stable, providing the device with excellent anti-interference capabilities and preventing malfunctions of the penstock protection valve 4.

[0040] Pre-reset state: After the device is triggered, if the medium flow rate falls below the set value, the counterweight 10 and the flip plate 8 return to their initial positions under the action of the counterweight 10. However, the compression spring 18 does not activate the handle shaft 15, linkage sleeve 16, spring seat shaft 17, and spring rod 19. The reversing valve 5 remains in the reversing state, and the position detection switch 13 is on. The penstock protection valve 4 remains closed. Only after the fault is resolved can the reset handle 12 be operated to reset the handle shaft 15, linkage sleeve 16, spring seat shaft 17, and spring rod 19 to their initial state. This will return the device 1 to its normal state. Only then can the penstock protection valve 4 open.

[0041] After the device 1 is triggered, it will automatically hold until the fault is eliminated and the device is manually reset. In this way, the penstock protection valve 4 can better protect the safety of the water diversion penstock, the hydropower station unit and the powerhouse.

[0042] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. A mechanical overspeed protection device for a penstock protection valve, characterized by: The cam is provided with a trigger driving device and a cam, and a reversing valve is provided above the cam. One end of the flip plate is arranged in a pipeline, and the other end is connected to the rotating shaft. The trigger driving device includes a linkage sleeve, a spring seat shaft, a compression spring, a spring rod, a spring seat and a secondary shaft. The linkage sleeve is arranged on the handle shaft, and the spring seat shaft is hinged to the end of the linkage sleeve. The compression spring is arranged on the spring rod, one end of the spring rod passes through the spring seat shaft, and the other end is connected to the spring seat. The spring seat is rotatably connected to the box body.

2. The mechanical overspeed protection device for a penstock protection valve according to claim 1 is characterized in that: A box body is provided on the device body, and the trigger drive device, cam and handle shaft are all arranged in the box body.

3. The mechanical overspeed protection device for a penstock protection valve according to claim 1 is characterized in that: An adjustment seat is provided between the spring rod and the spring seat.

4. The mechanical overspeed protection device for a penstock protection valve according to claim 1 is characterized in that: The handle shaft and the secondary shaft are mounted on the box body through rolling bearings.

5. The mechanical overspeed protection device for a penstock protection valve according to claim 2 is characterized in that: A limiting bolt is provided in the box body.

6. The mechanical overspeed protection device for a penstock protection valve according to claim 1 is characterized by: The reversing valve is connected to the hydraulic control system to control the dynamic water closure of the pressure steel pipe protection valve.

7. The mechanical overspeed protection device for a penstock protection valve according to claim 1 is characterized by: The crank is provided with a counterweight block which is fixed by a nut and the position of the counterweight block is adjustable.

8. The mechanical overspeed protection device for a penstock protection valve according to claim 1 is characterized by: A reset handle is provided on the handle shaft.

9. The mechanical overspeed protection device for a penstock protection valve according to claim 2 is characterized by: The box body is provided with a position detection switch, which is connected to an electrical control system to output an accident alarm signal.

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