Self-adaptive adjustment overspeed protection device for hydraulic power plant unit and protection method of self-adaptive adjustment overspeed protection device

Abstract

The invention relates to the technical field of hydroelectric generation, and discloses a hydraulic power plant unit overspeed protection device and a protection method thereof.The hydraulic power plant unit overspeed protection device comprises a volute, a rotating shaft is rotationally installed on the volute, a square pipe is connected to the volute, a throttling assembly is arranged on the square pipe, and the throttling assembly comprises a fixing frame; two pairs of throttle plates are rotationally mounted on the fixed frame; a power mechanism is arranged on the volute and can trigger the throttling assembly to adjust the overflowing area of the square tube according to the rotating speed of the rotating shaft. Through cooperation of the power mechanism and the throttling assembly, when the rotating shaft is overspeed due to increase of water flow, the power mechanism triggers the throttling assembly through centrifugal force generated by rotation of the rotating shaft, then the two pairs of throttling plates are driven to rotate, and after the throttling plates rotate, the shielding area of a flow channel in a square pipe can be increased through the throttling plates; therefore, the flow of water flowing into the volute is reduced by reducing the overflowing area.

Description

Technical Field

[0001] This invention relates to the field of hydropower technology, specifically to an adaptive overspeed protection device and its protection method for hydropower plant units. Background Technology

[0002] Hydropower plant generating units are the core equipment for hydropower generation. They operate based on the principle of converting water flow potential energy into mechanical energy and then into electrical energy. The core components include the spiral casing, turbine, shaft, and generator set. The spiral casing optimizes the water flow guidance, allowing the water flow potential energy within the casing to drive the turbine to rotate. The mechanical energy is then transmitted to the generator set via the shaft and converted into electrical energy. The generator set integrates intelligent control technology, upgrading from early mechanical regulation to a microcomputer monitoring and variable frequency speed control integrated system. As a key piece of equipment for clean energy, hydropower plant generating units can be flexibly started and stopped, and loads can be adjusted to adapt to grid peak shaving and different river basin hydrological conditions. They are an important support for ensuring power supply and reducing emissions and carbon emissions during the energy structure transformation.

[0003] However, the existing technology has the following problems: when the water flow velocity suddenly increases and the flow rate exceeds the design threshold, the water flow may cause the water turbine and shaft to rotate too fast, which will lead to increased vibration and fatigue damage of core components such as the water turbine and shaft, ultimately affecting the stability of the power grid frequency and causing power supply fluctuations. Summary of the Invention

[0004] The purpose of this invention is to provide an adaptive overspeed protection device and its protection method for hydropower plant units in order to solve the above-mentioned problems and overcome the defects of the prior art, as detailed below.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention provides an adaptive overspeed protection device for hydropower plant units, comprising a volute, a rotating shaft rotatably mounted on the volute, with a water turbine and a generator set connected to its two ends respectively, a square tube connected to the volute, and a throttling assembly mounted on the square tube. The throttling assembly includes a fixed frame mounted on the inner wall of the square tube, and two pairs of throttling plates rotatably mounted on the fixed frame. The top of each throttling plate protrudes from the top of the fixed frame and is connected to a lever. Two slides are slidably connected to the top of the fixed frame, each slide having two square holes. Four levers are located within the four square holes. When the slides move, they can rotate a pair of throttling plates through the interaction of the two square holes and the two levers, reducing the flow area within the square tube. A power mechanism is provided on the volute, which can trigger the throttling assembly to adjust the flow area of ​​the square tube according to the rotational speed of the rotating shaft.

[0006] Preferably, a long groove is provided at the connection between the top of the square tube and the fixed frame, and both of the slides are located in the square groove of the square tube. The cross-section of the throttling plate is elliptical. A slide rod is vertically slidably connected to the top of the fixed frame. Two connecting rods are hinged to the slide rod. The ends of the two connecting rods away from the slide rod are respectively hinged to the two slides. When the slide rod moves down, it can drive the two slides to move away from the slide rod through the two connecting rods respectively.

[0007] Preferably, a sealing cylinder is installed on the top inner side of the fixed frame, and the bottom end of the slide rod is slidably sleeved with the sealing cylinder.

[0008] Preferably, the power mechanism includes a first bracket mounted on a volute. A grooved rod is vertically slidably connected to the first bracket. One end of the grooved rod has a first sliding groove, and the other end of the grooved rod is connected to a slider. A second bracket is mounted on the volute. An installation shaft is rotatably mounted on the second bracket. A pry bar is connected to the outer wall of the installation shaft. One end of the pry bar is connected to a first sliding shaft, and the other end of the pry bar has a second sliding groove. The top of the sliding bar is connected to a second sliding shaft. The first sliding shaft is slidably connected to the first sliding groove of the grooved rod, and the second sliding shaft is slidably connected to the second sliding groove of the pry bar. When the grooved rod moves upward, it can drive the sliding bar downward through the pry bar.

[0009] Preferably, the power mechanism further includes a sleeve, which is vertically slidably fitted onto the rotating shaft. Two push rods are hinged to the outer wall of the sleeve, and two right-angle rods are hinged to the outer wall of the rotating shaft. One end of each of the two right-angle rods is connected to a counterweight, and the other end of each right-angle rod is hinged to the end of the two push rods away from the sleeve. A grooved ring is connected to the top of the sleeve, and the grooved ring has an annular groove. The sliding ball is located in the annular groove of the grooved ring. When the two right-angle rods swing away from the rotating shaft, they can drive the sleeve to move upward through the two push rods.

[0010] Preferably, the power mechanism further includes a lubrication assembly, which includes a liquid cylinder mounted on a first support. A liquid pipe is installed on the liquid cylinder. The liquid pipe is made of a flexible material, and a portion of the liquid pipe is located inside a groove rod. An oil hole is provided on the slider, and the liquid pipe communicates with the oil hole of the slider.

[0011] Preferably, an air cylinder is installed at the bottom of the liquid cylinder, the air cylinder passes through the top of the first support, the air cylinder is provided with a telescopic end that can automatically rebound, and the telescopic end of the air cylinder is located on the movement trajectory of the groove rod.

[0012] Preferably, the volute is provided with a recording component, which includes a third bracket mounted on the volute. A scale is mounted on the third bracket, a cam is connected to the mounting shaft, and a guide rod is connected to the cam. The guide rod passes through the scale, and a short shaft is rotatably mounted on the scale. A return spring is provided on the short shaft, and a pointer is connected to the short shaft. The guide rod abuts against the pointer, and the pointer can rotate when the guide rod moves. The scale is provided with graduation lines corresponding to the rotation angle of the throttle plate.

[0013] Preferably, a mechanical counter is installed on the third bracket, a trigger rod is installed on the mechanical counter, and a protruding rod is connected to the short shaft. When the protruding rod swings, it can contact the trigger rod and trigger the mechanical counter to count.

[0014] An adaptive overspeed protection method for hydropower plant units includes the following steps: Step 1: Normal operation and maintenance. When the shaft speed is normal, the throttling plate in the throttling component is parallel to the water flow. At this time, the flow area of ​​the square tube is the largest, ensuring the water inlet flow of the volute. Step 2: When the overspeed signal is triggered and the shaft speed exceeds the limit, the centrifugal force of the counterweight increases, causing the right-angle rod to swing away from the shaft, which in turn pushes the sleeve to move upward along the shaft through the push rod; Step 3: Power transmission conversion. The sleeve drives the grooved ring to move upward. The grooved ring pulls the grooved rod upward through the slider, causing the grooved rod to push the pry bar to rotate around the mounting shaft, which in turn drives the slide bar to move vertically downward. Step 4: Throttling and speed reduction protection. The slide bar moves down and drives the slide to move through the connecting rod. The slide pushes the throttling plate to rotate through the lever, thereby reducing the flow area of ​​the square tube, reducing water ingress into the volute, and reducing the rotation speed of the shaft. Step 5: Status recording and feedback. The light rod drives the pointer to swing, thereby indicating the degree of overspeed. The short shaft drives the cam to trigger the mechanical counter, recording this overspeed event. Step Six: Reset to normal, the shaft speed drops, the power mechanism resets, the carriage drives the throttle plate back to its original position, and the pointer resets under the action of the reset spring.

[0015] The beneficial effects are: 1. The overspeed protection device of this hydropower plant unit, through the cooperation of the power mechanism and the throttling component, enables the power mechanism to trigger the throttling component when the shaft speed exceeds the limit due to increased water flow. This triggers the throttling component, which in turn drives two pairs of throttling plates to rotate. When the throttling plates rotate, they increase the blocking area of ​​the flow channel inside the square tube, thereby reducing the water flow entering the volute by reducing the flow area. This slows down the rotation speed of the turbine and ultimately limits the shaft speed, preventing damage to the generator unit due to overspeed. The higher the shaft speed, the greater the swing amplitude of the counterweight and the farther the sleeve moves upward, resulting in a greater rotation amplitude of the two pairs of throttling plates and a greater reduction in the flow area inside the square tube, thus achieving adaptive adjustment of speed and flow area.

[0016] 2. The overspeed protection device of this hydropower plant unit, through the setting of the lubrication component, allows the liquid cylinder to be forced through the oil hole of the sliding ball by positive pressure when the power mechanism is triggered. This lubricates the contact area between the sliding ball and the groove ring, reducing the sliding friction resistance between them, while also reducing wear and noise. 3. The overspeed protection device of this hydropower plant unit, through the setting of the recording component, causes the pointer to move forward on the scale line of the dial when the throttling component is triggered, thus indirectly reflecting the flow area of ​​the square tube and the degree of overspeed of the rotating shaft. At the same time, the trigger rod, squeezed by the convex rod, triggers the mechanical counter to count, recording an overspeed event and providing data support for the analysis of the unit's operating status. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the volute structure of the present invention; Figure 3 This is a schematic diagram of the power mechanism structure of the present invention; Figure 4 This is a schematic diagram of the right-angle rod structure of the present invention; Figure 5 This is a schematic diagram of the grooved rod structure of the present invention; Figure 6 This is a schematic diagram of the throttling component structure of the present invention; Figure 7 This is a schematic diagram of the pry bar structure of the present invention; Figure 8This is a schematic diagram of the throttle plate structure of the present invention; Figure 9 This is a schematic diagram of the carriage structure of the present invention; Figure 10 This is a schematic diagram of the lubrication mechanism of the present invention; Figure 11 This is a schematic diagram of the recording component structure of the present invention; Figure 12 This is a schematic diagram of the dial structure of the present invention.

[0019] The annotations in the attached figures are explained as follows: 1. Volute; 2. Shaft; 3. Square tube; 4. Power mechanism; 41. Sleeve; 42. Grooved ring; 43. Right-angle rod; 44. Counterweight; 45. Push rod; 46. First bracket; 47. Grooved rod; 48. Sliding ball; 49. Second bracket; 410. Mounting shaft; 411. Pry bar; 412. First sliding shaft; 5. Throttling assembly; 51. Fixing frame; 52. Throttling plate; 53. Slide rod; 54. Second slide shaft; 55. Sealing cylinder; 56. Connecting rod; 57. Slide carriage; 58. Square hole; 59. Toggle lever; 6. Lubrication assembly; 61. Liquid cylinder; 62. Liquid pipe; 63. Air cylinder; 7. Recording assembly; 71. Third support; 72. Dial; 73. Cam; 74. Smooth rod; 75. Short shaft; 76. Pointer; 77. Mechanical counter; 78. Trigger rod; 79. Protruding rod. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0021] One embodiment of the present invention is as follows: Please see Figure 1 - Figure 9An adaptive overspeed protection device for a hydropower plant unit includes a volute 1, a rotating shaft 2 rotatably mounted on the volute 1, with its two ends connected to a water turbine and a generator set respectively. A square tube 3 is connected to the volute 1, and a throttling assembly 5 is installed on the square tube 3. The throttling assembly 5 includes a fixed frame 51, which is installed on the inner wall of the square tube 3. Two pairs of throttling plates 52 are rotatably mounted on the fixed frame 51, with the top of each throttling plate 52 protruding from the top of the fixed frame 51. A lever 59 is connected to the top of each throttling plate 52. Two slides 57 are slidably connected to the top of the fixed frame 51, with two square holes 58 on each slide. Four levers 59 are located in the four square holes 58 respectively. When the slides 57 move, they can pass through the two square holes 58 and the two levers 59. The cooperation of 9 drives a pair of throttling plates 52 to rotate. After the throttling plates 52 rotate, they can reduce the flow area inside the square tube 3. When the slide 57 moves horizontally along the top of the fixed frame 51, the inner wall of the square hole 58 on the slide 57 will generate a lateral thrust on the lever 59 inside, which will push the lever 59 to swing around the hinge point between the throttling plate 52 and the fixed frame 51, so that the lever 59 drives the throttling plate 52 to rotate synchronously. Under normal conditions, the throttling plate 52 is parallel to the water flow direction. When the throttling plate 52 rotates, it will increase the blocking area of ​​the flow channel inside the square tube 3, thereby reducing the flow rate of water entering the volute 1 by reducing the flow area, thus slowing down the rotation speed of the water turbine, and finally limiting the speed of the rotating shaft 2 to avoid damage to the generator set due to overspeed.

[0022] Furthermore, a long groove is provided at the connection between the top of the square tube 3 and the fixed frame 51. Both slides 57 are located within the square groove of the square tube 3. The cross-section of the throttle plate 52 is elliptical. A slide rod 53 is vertically slidably connected to the top of the fixed frame 51. Two connecting rods 56 are hinged to the slide rod 53. The ends of the two connecting rods 56 away from the slide rod 53 are respectively hinged to the two slides 57. When the slide rod 53 moves downward, it can drive the two slides 57 to move away from the slide rod 53 through the two connecting rods 56 respectively. When the elliptical cross-section throttle plate 52 rotates... Its curved surface can reduce the resistance generated by water flow impact, and at the same time make the adjustment of the flow area smoother. When the slide bar 53 moves vertically down along the fixed frame 51, it will drive the two connecting rods 56 to unfold synchronously through the hinge point. The connecting rod 56 converts the vertical movement of the slide bar 53 into the horizontal movement of the carriage 57, so that the two carriages 57 move synchronously in a direction away from the slide bar 53, thereby driving the two pairs of throttling plates 52 to rotate, achieving the throttling effect. Moreover, the rotation angle of the two pairs of throttling plates 52 is consistent, ensuring the uniformity of the flow area adjustment.

[0023] In addition, a sealing cylinder 55 is installed on the top inner side of the fixed frame 51, and the bottom end of the slide rod 53 is slidably sleeved with the sealing cylinder 55; the inner wall of the sealing cylinder 55 is tightly fitted with the outer wall of the slide rod 53, which can prevent water in the square tube 3 from leaking through the gap between the slide rod 53 and the fixed frame 51, and at the same time guide the vertical sliding of the slide rod 53, thereby improving the operational reliability and sealing performance of the throttling component 5.

[0024] In addition, a power mechanism 4 is provided on the volute 1. The power mechanism 4 can trigger the throttling component 5 to adjust the flow area of ​​the square tube 3 according to the rotation speed of the shaft 2. When the rotation speed of the shaft 2 is within the normal range, the power mechanism 4 remains stationary and the throttling component 5 maintains the maximum flow area of ​​the square tube 3 to ensure normal power generation of the unit. When the rotation speed of the shaft 2 exceeds the safety threshold, the power mechanism 4 will immediately start the mechanical transmission to transmit an action signal to the throttling component 5, prompting the throttling component 5 to quickly adjust the flow area and ensure that the unit speed is always controlled within the safe range.

[0025] It is worth noting that the power mechanism 4 includes a first bracket 46, which is mounted on the volute 1. A grooved rod 47 is vertically slidably connected to the first bracket 46. One end of the grooved rod 47 has a first sliding groove, and the other end of the grooved rod 47 is connected to a slider 48. A second bracket 49 is mounted on the volute 1. A mounting shaft 410 is rotatably mounted on the second bracket 49. A pry bar 411 is connected to the outer wall of the mounting shaft 410. One end of the pry bar 411 is connected to a first sliding shaft 412, and the other end of the pry bar 411 has a second sliding groove. The top of the sliding rod 53 is connected to a second sliding shaft 54. The first sliding shaft 412 is slidably connected to the first sliding groove of the grooved rod 47. Next, the second sliding shaft 54 ​​is slidably connected to the second sliding groove of the pry bar 411. When the groove bar 47 moves upward, it can drive the sliding bar 53 to move downward through the pry bar 411. The first bracket 46 provides vertical sliding support and guidance for the groove bar 47, ensuring that the groove bar 47 can only move in the vertical direction. When the groove bar 47 moves upward, its first sliding groove will drive the first sliding shaft 412 to move upward synchronously, so that the first sliding shaft 412 drives the pry bar 411 to rotate around the mounting shaft 410. The other end of the pry bar 411 pushes the second sliding shaft 54 ​​downward through the second sliding groove, so that the second sliding shaft 54 ​​drives the sliding bar 53 to move vertically downward, thereby triggering the rotation of the two pairs of throttle plates 52.

[0026] It is worth noting that the power mechanism 4 also includes a sleeve 41, which is vertically slidably fitted onto the rotating shaft 2. Two push rods 45 are hinged to the outer wall of the sleeve 41, and two right-angle rods 43 are hinged to the outer wall of the rotating shaft 2. One end of each right-angle rod 43 is connected to a counterweight 44, and the other end is hinged to the end of each push rod 45 away from the sleeve 41. A grooved ring 42 is connected to the top of the sleeve 41, and the grooved ring 42 has an annular groove. A sliding ball 48 is located within the annular groove of the grooved ring 42. When the two right-angle rods 43 swing away from the rotating shaft 2, they can drive the sleeve 41 upward through the two push rods 45. The sleeve 41 is slidably fitted with the rotating shaft 2, allowing the sleeve 41 to rotate synchronously with the rotating shaft 2 and slide along the axial direction of the rotating shaft 2. The counterweight 44 operates based on the principle of centrifugal force. When the rotation speed of the rotating shaft 2 is maintained within the normal range, the counterweight 44 remains downward. The right-angle rods 43 are L-shaped, and the right-angle rods 43 are connected to the counterweight 44... The section connected to the hammer 44 remains vertical. When the rotational speed of the shaft 2 increases, the centrifugal force on the hammer 44 increases accordingly. After exceeding the normal rotational speed of the shaft 2, the hammer 44 begins to drive the right-angle rod 43 to swing around the hinge point with the shaft 2 in a direction away from the shaft 2, causing the section connected to the right-angle rod 43 and the hammer 44 to change from vertical to horizontal. When the right-angle rod 43 swings, its end away from the hammer 44 converts the swinging motion into the vertical upward movement of the sleeve 41 through the push rod 45. The sleeve 41 drives the grooved ring 42 to move upward synchronously. The annular groove of the grooved ring 42 drives the grooved rod 47 to move upward through the slider 48, realizing the precise transmission of the speed signal to the mechanical action. The higher the rotational speed of the shaft 2, the greater the swing amplitude of the hammer 44, and the farther the sleeve 41 moves upward, ultimately making the rotation amplitude of the two pairs of throttling plates 52 greater and the flow area in the square tube 3 smaller, realizing the adaptive adjustment of speed and flow area.

[0027] Based on the above embodiments, another embodiment of the present invention is as follows: Please see Figure 2 , Figure 10The power mechanism 4 also includes a lubrication assembly 6, which includes a liquid cylinder 61 mounted on the first support 46. A liquid pipe 62, made of flexible material, is mounted on the liquid cylinder 61, with a portion of it located inside the grooved rod 47. An oil hole is provided on the slider 48, and the liquid pipe 62 communicates with the oil hole of the slider 48. An air cylinder 63 is mounted at the bottom of the liquid cylinder 61, extending through the top of the first support 46. The air cylinder 63 has a retractable end that automatically rebounds, and this retractable end is located on the movement trajectory of the grooved rod 47. The liquid cylinder 61 stores lubricant, and the flexible liquid pipe 62 can freely extend, retract, and bend with the movement of the grooved rod 47 without restricting its movement. During the stroke, the air cylinder 63 has an air pipe inside that communicates with the liquid cylinder 61. The telescopic end of the air cylinder 63 is normally kept in the extended state. When the groove rod 47 moves upward due to the excessive speed of the rotating shaft 2, the groove rod 47 will contact and squeeze the telescopic end of the air cylinder 63, causing the air cylinder 63 to inject its internal air into the liquid cylinder 61. The liquid cylinder 61, through positive pressure, pushes its internal lubricant through the liquid pipe 62 and squeezes it out from the oil hole of the ball 48, so that the lubricant lubricates the contact part between the ball 48 and the groove ring 42, reducing the sliding friction resistance between the two, while reducing wear and noise. When the rotation speed of the rotating shaft 2 returns to normal and the groove rod 47 returns to its downward reset, the telescopic end of the air cylinder 63 automatically rebounds and resets under its own elastic force.

[0028] Based on the above embodiments, another embodiment of the present invention is as follows: Please see Figure 2 , Figure 11 , Figure 12A recording component 7 is provided on the volute 1. The recording component 7 includes a third bracket 71, which is mounted on the volute 1. A dial 72 is mounted on the third bracket 71. A cam 73 is connected to a mounting shaft 410, and a guide rod 74 is connected to the cam 73. The guide rod 74 passes through the dial 72. A short shaft 75 is rotatably mounted on the dial 72. A return spring is provided on the short shaft 75, and a pointer 76 is connected to the short shaft 75. The guide rod 74 abuts against the pointer 76. When the guide rod 74 moves, it can drive the pointer 76 to rotate. The dial 72 has scale lines corresponding to the rotation angle of the throttle plate 52. The rotation of the mounting shaft 410 will synchronously drive the cam 73 to rotate. When the cam 73 rotates, it will drive the guide rod 74 to swing. The return spring on the short shaft 75 holds... The spring force is continuously applied so that the pointer 76 on the short shaft 75 always presses against the polished rod 74. Therefore, when the polished rod 74 swings, it pushes the pointer 76 to swing, which in turn drives the short shaft 75 to rotate against the spring force of the return spring, causing the pointer 76 to move in front of the scale line on the scale 72. The scale line on the scale 72 is precisely calibrated, and each scale corresponds to a specific rotation angle of the throttle plate 52, thereby indirectly reflecting the flow area of ​​the square tube 3 and the overspeed degree of the rotating shaft 2, allowing the staff to intuitively read the protection action range when the unit is overspeeding. When the rotation speed of the rotating shaft 2 returns to normal, the mounting shaft 410 reverses and resets, the thrust of the cam 73 on the polished rod 74 disappears, and the return spring on the short shaft 75 releases its elastic potential energy, causing the pointer 76 to rotate back and reset.

[0029] It is worth mentioning that a mechanical counter 77 is installed on the third bracket 71, and a trigger rod 78 is installed on the mechanical counter 77. A protruding rod 79 is connected to the short shaft 75. When the protruding rod 79 swings, it can contact the trigger rod 78 and trigger the mechanical counter 77 to count. The protruding rod 79 rotates synchronously with the short shaft 75. Its installation position has been adjusted. When the short shaft 75 drives the pointer 76 to rotate to half its stroke, the protruding rod 79 contacts the trigger rod 78. After the trigger rod 78 is squeezed by the protruding rod 79, it will trigger the mechanical counter 77 to count, realizing the recording of an overspeed event. The mechanical counter 77 adopts... The specific structure and working principle of the existing technology will not be elaborated here. The counting function of the mechanical counter 77 can accurately count the number of times the overspeed protection device is activated during the operation of the unit, providing data support for the analysis of the unit's operating status. When the staff finds that the mechanical counter 77 counts a lot within a unit of time, they need to investigate the cause of the overspeed and take corresponding measures. When the pointer 76 returns to the zero position under the action of the reset spring, the protruding rod 79 will swing in the opposite direction with the short shaft 75 and disengage from the trigger rod 78. The mechanical counter 77 maintains the current counting state and waits for the next trigger.

[0030] Based on the above embodiments, another embodiment of the present invention is as follows: An adaptive overspeed protection method for hydropower plant units, employing the adaptive overspeed protection device for hydropower plant units described in the above embodiments, further includes the following steps: Step 1: During normal operation and maintenance, when the rotation speed of shaft 2 is normal, the throttling plate 52 in the throttling assembly 5 is parallel to the water flow. At this time, the flow area of ​​square tube 3 is at its maximum, ensuring the water inlet flow of volute 1. Step 2: When the overspeed signal is triggered and the rotation speed of the shaft 2 exceeds the limit, the centrifugal force of the counterweight 44 increases, causing the right-angle rod 43 to swing away from the shaft 2, and pushing the sleeve 41 to move upward along the shaft 2 through the push rod 45; Step 3: Power transmission conversion. Sleeve 41 drives groove ring 42 to move upward. Groove ring 42 pulls groove rod 47 upward through slider 48, so that groove rod 47 pushes pry bar 411 to rotate around mounting shaft 410, thereby driving slide bar 53 to move vertically downward. Step 4: Throttling and speed reduction protection. The slide bar 53 moves down and drives the slide 57 to move through the connecting rod 56. The slide 57 pushes the throttling plate 52 to rotate through the lever 59, thereby reducing the flow area of ​​the square tube 3, reducing the water inlet of the volute 1, and reducing the speed of the rotating shaft 2. Step 5: Status recording and feedback. The light rod 74 drives the pointer 76 to swing, thereby indicating the degree of overspeed. The short shaft 75 drives the convex rod 79 to trigger the mechanical counter 77, which records the overspeed event. Step Six: Reset to normal, the rotation speed of shaft 2 drops, the power mechanism 4 resets, the slide 57 drives the throttle plate 52 back to its original position, and the pointer 76 resets under the action of the reset spring. The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An adaptive overspeed protection device for a hydropower plant unit, comprising a volute (1), a rotating shaft (2) rotatably mounted on the volute (1), the two ends of the rotating shaft (2) being connected to a water turbine and a generator set respectively, and a square tube (3) connected to the volute (1), characterized in that: A throttling assembly (5) is provided on the square tube (3). The throttling assembly (5) includes a fixed frame (51). The fixed frame (51) is installed on the inner wall of the square tube (3). Two pairs of throttling plates (52) are rotatably installed on the fixed frame (51). The top of the throttling plate (52) protrudes from the top of the fixed frame (51). A lever (59) is connected to the top of the throttling plate (52). Two slides (57) are slidably connected to the top of the fixed frame (51). Two square holes (58) are opened on the slides (57). The four levers (59) are located in the four square holes (58). When the slides (57) move, they can drive a pair of throttling plates (52) to rotate through the cooperation of the two square holes (58) and the two levers (59). After the throttling plates (52) rotate, they can reduce the flow area in the square tube (3). The volute (1) is provided with a power mechanism (4), which can trigger the throttling component (5) to adjust the flow area of ​​the square tube (3) according to the rotation speed of the shaft (2).

2. The adaptive overspeed protection device for hydropower plant units according to claim 1, characterized in that: A long groove is provided at the connection between the top of the square tube (3) and the fixed frame (51). The two slides (57) are located in the square groove of the square tube (3). The cross-section of the throttling plate (52) is elliptical. A slide rod (53) is vertically slidably connected to the top of the fixed frame (51). Two connecting rods (56) are hinged on the slide rod (53). The ends of the two connecting rods (56) away from the slide rod (53) are respectively hinged to the two slides (57). When the slide rod (53) moves down, it can drive the two slides (57) to move away from the slide rod (53) through the two connecting rods (56).

3. The adaptive overspeed protection device for hydropower plant units according to claim 2, characterized in that: A sealing cylinder (55) is installed on the top inner side of the fixed frame (51), and the bottom end of the slide rod (53) is slidably sleeved with the sealing cylinder (55).

4. The adaptive overspeed protection device for hydropower plant units according to claim 2, characterized in that: The power mechanism (4) includes a first bracket (46), which is mounted on the volute (1). A grooved rod (47) is vertically slidably connected to the first bracket (46). One end of the grooved rod (47) has a first sliding groove, and the other end of the grooved rod (47) is connected to a sliding ball (48). A second bracket (49) is mounted on the volute (1), and a mounting shaft (410) is rotatably mounted on the second bracket (49). The outer wall of the mounting shaft (410) is connected to a... A pry bar (411) is provided with a first sliding shaft (412) at one end and a second sliding groove at the other end. A second sliding shaft (54) is connected to the top of the sliding rod (53). The first sliding shaft (412) is slidably connected to the first sliding groove of the groove rod (47), and the second sliding shaft (54) is slidably connected to the second sliding groove of the pry bar (411). When the groove rod (47) moves upward, it can drive the sliding rod (53) downward through the pry bar (411).

5. The adaptive overspeed protection device for hydropower plant units according to claim 4, characterized in that: The power mechanism (4) also includes a sleeve (41), which is vertically slidably sleeved on the rotating shaft (2). Two push rods (45) are hinged to the outer wall of the sleeve (41), and two right-angle rods (43) are hinged to the outer wall of the rotating shaft (2). One end of each of the two right-angle rods (43) is connected to a counterweight (44), and the other end of each of the two right-angle rods (43) is hinged to the end of each of the two push rods (45) away from the sleeve (41). A grooved ring (42) is connected to the top of the sleeve (41). The grooved ring (42) has an annular groove, and the slider (48) is located in the annular groove of the grooved ring (42). When the two right-angle rods (43) swing away from the rotating shaft (2), they can drive the sleeve (41) to move upward through the two push rods (45).

6. The adaptive overspeed protection device for hydropower plant units according to claim 5, characterized in that: The power mechanism (4) also includes a lubrication assembly (6), which includes a liquid cylinder (61) mounted on a first bracket (46). A liquid pipe (62) is mounted on the liquid cylinder (61), which is made of a flexible material. A portion of the liquid pipe (62) is located inside a groove rod (47). An oil hole is provided on the slider (48), and the liquid pipe (62) communicates with the oil hole of the slider (48).

7. The adaptive overspeed protection device for hydropower plant units according to claim 6, characterized in that: An air cylinder (63) is installed at the bottom of the liquid cylinder (61). The air cylinder (63) passes through the top of the first support (46). The air cylinder (63) is provided with a telescopic end that can automatically rebound. The telescopic end of the air cylinder (63) is located on the movement trajectory of the groove rod (47).

8. The adaptive overspeed protection device for hydropower plant units according to claim 5, characterized in that: A recording component (7) is provided on the volute (1). The recording component (7) includes a third bracket (71). The third bracket (71) is mounted on the volute (1). A scale (72) is mounted on the third bracket (71). A cam (73) is connected to the mounting shaft (410). A light rod (74) is connected to the cam (73). The light rod (74) passes through the scale (72). A short shaft (75) is rotatably mounted on the scale (72). A return coil spring is provided on the short shaft (75). A pointer (76) is connected to the short shaft (75). The light rod (74) abuts against the pointer (76). When the light rod (74) moves, it can drive the pointer (76) to rotate. The scale (72) is provided with scale lines corresponding to the rotation angle of the throttle plate (52).

9. The adaptive overspeed protection device for hydropower plant units according to claim 8, characterized in that: A mechanical counter (77) is installed on the third bracket (71), a trigger rod (78) is installed on the mechanical counter (77), and a protruding rod (79) is connected to the short shaft (75). When the protruding rod (79) swings, it can contact the trigger rod (78) and trigger the mechanical counter (77) to count.

10. An adaptive regulation overspeed protection method for hydropower plant units, characterized in that: The adaptive overspeed protection device for hydropower plant units according to any one of claims 1-9 further includes the following steps: Step 1: Normal operation and maintenance. When the rotation speed of the shaft (2) is normal, the throttling plate (52) in the throttling component (5) is parallel to the water flow. At this time, the flow area of ​​the square tube (3) is the largest, ensuring the water flow rate of the volute (1). Step 2: When the speed of the rotating shaft (2) exceeds the limit, the centrifugal force of the counterweight (44) increases, causing the right-angle rod (43) to swing away from the rotating shaft (2), and pushing the sleeve (41) to move upward along the rotating shaft (2) through the push rod (45); Step 3: Power transmission conversion. The sleeve (41) drives the grooved ring (42) to move upward. The grooved ring (42) pulls the grooved rod (47) upward through the slider (48), so that the grooved rod (47) pushes the pry bar (411) to rotate around the mounting shaft (410), thereby driving the slide bar (53) to move vertically downward. Step 4: Throttling and speed reduction protection. The slide bar (53) moves down and drives the slide (57) to move through the connecting rod (56). The slide (57) pushes the throttling plate (52) to rotate through the lever (59), thereby reducing the flow area of ​​the square tube (3), reducing the water inlet of the volute (1), and reducing the rotation speed of the shaft (2). Step 5: Status recording feedback. The light rod (74) drives the pointer (76) to swing, thereby indicating the degree of overspeed. The short shaft (75) drives the convex rod (79) to trigger the mechanical counter (77) to record the overspeed event. Step 6: Reset to normal, the rotation speed of the shaft (2) drops, the power mechanism (4) resets, the slide (57) drives the throttle plate (52) back to its original position, and the pointer (76) resets under the action of the reset coil spring.

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