Sand washing device for hydroelectric power generation

Abstract

The invention relates to the field of hydroelectric power generation facilities, in particular to a sand washing device for hydroelectric power generation. The device comprises a sand blocking assembly, an impact table, a backflow table, a traction piece and a sand scraping assembly. The sand blocking assembly is arranged on a water diversion opening of a dam in the water flow direction, and gravel in water flow is blocked by forming a high-low fluctuating trend. The impact table is located on one side of the sand blocking assembly, and the top is provided with a transverse flushing sand washing gate. The backflow table is located on the other side of the sand blocking assembly, the side wall is provided with a backflow culvert communicating with the sand blocking assembly, and the bottom is provided with a sand collecting box communicating with the backflow culvert and the sand outlet pipe. The backflow table is further provided with an opening and closing assembly used for blocking the backflow culvert. The traction piece is connected with a gate of the sand-washing gate and the opening-closing assembly. According to the sand washing device, high-pressure and high-speed water flow washing of the sand washing gate is combined with scraping and sand removing of the sand scraping assembly, and the sand washing and sand discharging efficiency and effect are effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of hydroelectric power generation facilities, and particularly to a sand flushing device for hydroelectric power generation. Background Art

[0002] Sand and gravel are likely to accumulate near the water intake of the reservoir. The siltation of sand and gravel will reduce the reservoir capacity and lower the power generation head. Sand and gravel entering the water turbine may wear the blades and shorten the service life of the equipment. The siltation of sand and gravel will also block the water diversion system and increase the maintenance cost. Therefore, in large hydropower stations, the sand flushing device, as an important water conservancy equipment, is mainly used to remove the sediment deposited in the reservoir or the water diversion channel.

[0003] A Chinese patent document with the authorization announcement number of CN114197411B, a water conservancy and hydropower sand flushing system, includes a dam main body and a sand retaining dam provided at the upstream inlet section of the dam main body. A sand discharge culvert is provided at the bottom of the dam main body, and a sand discharge gate is provided in the sand discharge culvert; a sand discharge corridor is provided at the bottom of the front wall surface of the sand retaining dam, and the sand discharge corridor is connected to the sand discharge culvert through a sand discharge pipe; a grid plate is provided on the upstream side of the sand retaining dam, the top of the grid plate is fixedly connected to the sand retaining dam through a top plate, and the bottom of the grid plate is fixedly connected to a bottom plate; a plurality of wing plates are fixedly provided on the front wall surface of the grid plate, the wing plates incline downward in the direction away from the grid plate, and the control opening formed by two adjacent wing plates has a lift H1.

[0004] The above sand flushing device uses the sand retaining dam to suck and discharge sand unidirectionally. Since the suction cavity is always open, the water flow and sundries in the reservoir are easily mixed with sand and gravel and enter the suction cavity, which not only causes the loss of the reservoir capacity, but also is prone to blockage. At the same time, the sand discharge mainly uses the water flow scouring on one side of the sand retaining dam. Not only the sand discharge method is single, but also the scouring power cannot be guaranteed, resulting in a large limitation of the sand discharge efficiency and insufficient stability. Summary of the Invention

[0005] Aiming at the problems existing in the background art, a sand flushing device for hydroelectric power generation is proposed, which combines the high-pressure and high-speed water flow scouring of the sand discharge gate and the sand scraping of the sand scraping component, effectively improving the efficiency and effect of sand flushing and sand discharge.

[0006] The present invention provides a sand flushing device for hydraulic power generation, which includes a sand retaining component, an impact platform, a return platform, a traction member, and a sand scraping component. The sand retaining component is arranged on the water intake of the dam along the water flow direction, intercepting sand and gravel in the water flow by forming a high and low undulating trend; the impact platform is located on one side of the sand retaining component, and a sand flushing gate for horizontal water flushing is arranged on the top; the return platform is located on the other side of the sand retaining component, a return culvert communicating with the sand retaining component is arranged on the side wall, and a sand collecting box connecting the return culvert and the sand discharging pipe is arranged at the bottom; an opening and closing component for blocking the return culvert is also arranged on the return platform; one end of the traction member is connected to the gate of the sand flushing gate, and the other end is connected to the opening and closing component; when the gate rises, the traction member extends, and the opening and closing component opens the return culvert; when the gate descends, the traction member shortens, and the opening and closing component closes the return culvert; the sand scraping component is connected in series on the traction member, and moves back and forth on the sand retaining component to scrape sand along with the extension and shortening of the traction member and the scouring of the water flow.

[0007] Preferably, an installation cavity is arranged inside the impact platform; a first deflection roller is arranged in the installation cavity; a second deflection roller is arranged on the frame of the sand flushing gate; one end of the traction member is connected to the top of the gate, and the other end sequentially bypasses the second deflection roller and the first deflection roller, passes through the sand retaining component, extends into the return culvert and is connected to the opening and closing component.

[0008] Preferably, a sand collecting cavity communicating the return culvert and the sand collecting box is arranged inside the return platform; the opening and closing component includes a telescopic rod located in the sand collecting cavity; the end of the telescopic rod extends into the return culvert and is connected to a sealing seat, and a return spring is sleeved outside the telescopic rod; a sealing platform matching the return culvert is arranged at the front end of the sealing seat; the end of the traction member is connected to the sealing platform.

[0009] Preferably, a magnetic adsorption layer is arranged on the sealing seat; an electromagnet acting on the sealing seat is arranged in the sand collecting cavity.

[0010] Preferably, the sand retaining component includes a sand retaining seat located between the impact platform and the return platform; sand retaining grooves and sand retaining platforms are alternately arranged on the sand retaining seat; the sand retaining grooves and the sand retaining platforms form a sand retaining structure with high and low undulations along an S-shaped track; the sand retaining structure is communicated with the return culvert; the traction member passes through the sand retaining grooves; the sand scraping component is pulled by the traction member and moves back and forth in the sand retaining grooves to scrape sand.

[0011] Preferably, the sand scraping component includes two groups of positioning heads arranged in pairs on the traction member; a sliding sleeve is slidably sleeved on the traction member and is located between the two groups of positioning heads; an elastic telescopic sleeve wrapping the traction member is arranged between the sliding sleeve and the positioning heads on both sides, and a rotatable sand scraping cylinder is arranged on the outer periphery of the sliding sleeve.

[0012] Preferably, the sand scraping cylinder is provided with a hollow for water flow to pass through, a pushing paddle is arranged on one side of the hollow, and a sand scraping frame is arranged on the side wall of the sand scraping cylinder.

[0013] Preferably, the sand retaining groove is set as a semi-cylindrical groove, one side of the groove opening is in one-to-one correspondence and communication with the return culvert, and the other side of the groove opening abuts against the impact platform; the sand retaining platform is set as a solid pillow shape; the sand scraping cylinder is located in the sand retaining groove.

[0014] Preferably, the sand retaining groove is set as a semi-cylindrical groove, one side of the groove opening is in one-to-one correspondence and communication with the return culvert, and the other side of the groove opening abuts against the impact platform; the sand retaining platform is set as a hollow pillow-shaped structure, and a sand inlet communicating with the sand retaining groove is arranged at the bottom of the water-facing side, and a sand storage cavity is arranged inside; the sand storage cavity gradually becomes smaller from top to bottom and communicates with the sand inlet at the bottom; the sand scraping cylinder is located in the sand retaining groove.

[0015] Preferably, the sand scraping assembly further includes a sand discharging ball; the sand discharging ball is movably arranged in the sand storage cavity and is larger than the sand inlet, and the sand discharging ball is connected to the sliding sleeve through a connecting chain.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: a sand retaining structure that undulates along an S-shaped trajectory is provided to intercept the sand and gravel carried in the water flow, so that the sand and gravel stay in the sand storage cavity and the sand retaining groove. It not only has a large capacity for accommodating sand and gravel, but also reduces the damage to hydropower caused by the direct exposure of sand and gravel, and reduces the frequency of sand flushing. A sand flushing gate is provided to flush water from one side of the water flow to the other side, and the sand and gravel in the sand retaining structure are scoured by high-speed and high-pressure water flow. The traction member is stretched as the gate rises. When it is stretched, on the one hand, the sealing platform is released by the traction member, and the water flow impact causes the sealing platform to be stressed inward, releasing the blockage of the return culvert, and the sand and gravel are washed into the return culvert. On the other hand, the sand scraping assembly is washed by the water flow and moves towards the return culvert. During the movement, the sand scraping cylinder drives the elastic telescopic sleeves on both sides to bounce back and forth, driving the sand scraping cylinder to rotate and the sand scraping frame to rotate, scraping the sand and gravel attached to the sand retaining structure. At the same time, the sliding sleeve slides and pulls the sand discharging ball to move in the sand storage cavity, assisting the sand and gravel to enter the return culvert from the sand storage cavity and the sand retaining groove. Finally, the sand and gravel are discharged from the sand outlet pipe. The sand flushing combines the high-pressure and high-speed water flow flushing of the sand flushing gate and the scraping of the sand scraping assembly to effectively improve the efficiency and effect of sand flushing and sand discharging. It is applicable to local sand flushing near the water intake of the dam and can significantly improve the long-term operation efficiency and safety of the hydropower station. Description of the Drawings

[0017] Figure 1 Structural diagram of the sand flushing device for hydropower (Viewpoint 1);

[0018] Figure 2 Structural diagram of the sand flushing device for hydropower (Viewpoint 2);

[0019] Figure 3 Structural diagram of the sand flushing device for hydropower (Viewpoint 3);

[0020] Figure 4 Internal structural diagram of the installation cavity and the sand collection cavity;

[0021] Figure 5 It is a structural diagram of the impact platform and the sand flushing gate;

[0022] Figure 6 It is a sectional view of the reflux platform;

[0023] Figure 7 It is a structural diagram of the sand interception component in the second embodiment;

[0024] Figure 8 It is a structural diagram of the sand scraping component in the second embodiment;

[0025] Figure 9 It is a structural diagram of the sand interception component in the third embodiment;

[0026] Figure 10 It is Figure 9 an enlarged view of part A in

[0027] Reference numerals: 1, sand interception component; 101, sand interception seat; 102, sand interception groove; 103, sand interception platform; 104, sand inlet; 105, sand storage cavity; 2, impact platform; 201, installation cavity; 202, first deflector roll; 3, reflux platform; 301, sand collection cavity; 302, reflux culvert; 4, sand flushing gate; 401, gate; 402, second deflector roll; 5, sand discharge pipe; 6, sand collection box; 7, sand scraping component; 701, positioning head; 702, sand scraping cylinder; 703, sand scraping frame; 704, pushing paddle; 705, hollowing; 706, sliding sleeve; 707, elastic telescopic sleeve; 8, traction member; 9, opening and closing component; 901, plugging seat; 902, telescopic rod; 903, return spring; 904, sealing platform; 905, electromagnet; 10, sand discharge ball; 11, connecting chain. Detailed implementation manners

[0028] In the first embodiment, as Figures 1 - 3 shown, the present invention provides a sand flushing device for hydroelectric power generation, including a sand interception component 1, an impact platform 2, a reflux platform 3, a traction member 8 and a sand scraping component 7. The sand interception component 1 is arranged on the water intake of the dam along the water flow direction, and intercepts the sand and gravel in the water flow by forming a undulating trend; the impact platform 2 is located on one side of the sand interception component 1, and a sand flushing gate 4 for horizontal water flushing is arranged on the top; the reflux platform 3 is located on the other side of the sand interception component 1, a reflux culvert 302 communicated with the sand interception component 1 is arranged on the side wall, and a sand collection box 6 communicating the reflux culvert 302 and the sand discharge pipe 5 is arranged at the bottom; an opening and closing component 9 for blocking the reflux culvert 302 is also arranged on the reflux platform 3; one end of the traction member 8 is connected to the gate 401 of the sand flushing gate 4, and the other end is connected to the opening and closing component 9; when the gate 401 rises, the traction member 8 extends, and the opening and closing component 9 opens the reflux culvert 302; when the gate 401 descends, the traction member 8 shortens, and the opening and closing component 9 closes the reflux culvert 302; the sand scraping component 7 is connected in series on the traction member 8, and moves back and forth on the sand interception component 1 to scrape sand along with the extension and shortening of the traction member 8 and the scouring of the water flow.

[0029] As shown Figures 4 - 5 in the figure, an installation cavity 201 is arranged inside the impact table 2; a first deflection roller 202 is arranged in the installation cavity 201; a second deflection roller 402 is arranged on the frame of the sand flushing gate 4; one end of the traction member 8 is connected to the top of the gate 401, and the other end sequentially bypasses the second deflection roller 402 and the first deflection roller 202, then passes through the sand blocking assembly 1, extends into the return culvert 302 and is connected to the opening and closing assembly 9.

[0030] It should be further noted that the traction member 8 is arranged as a steel rope.

[0031] When the gate 401 rises, the end of the steel rope rises, extends along the second deflection roller 402 and the first deflection roller 202. At this time, the opening and closing assembly 9 is loosened by the steel rope, and the blockage of the return culvert 302 can be released. The flushed sand and gravel can enter the sand collecting box 6 through the return culvert 302. When the gate 401 descends, the end of the steel rope descends, shortens along the second deflection roller 402 and the first deflection roller 202. At this time, the opening and closing assembly 9 is pulled by the steel rope, and the return culvert 302 can be blocked.

[0032] As shown Figure 4 and Figure 6 in the figure, a sand collecting cavity 301 communicating the return culvert 302 and the sand collecting box 6 is arranged inside the return table 3; the opening and closing assembly 9 includes a telescopic rod 902 located in the sand collecting cavity 301; the end of the telescopic rod 902 extends into the return culvert 302 and is connected to the blocking seat 901. A return spring 903 is sleeved outside the telescopic rod 902; a sealing table 904 matching the return culvert 302 is arranged at the front end of the blocking seat 901. The end of the traction member 8 is connected to the sealing table 904.

[0033] It should be further noted that one end of the return spring 903 is connected to the blocking seat 901, and the other end is connected to the cavity wall of the sand collecting cavity 301.

[0034] When the sealing table 904 is loosened by the steel rope, the water flow impact causes the sealing table 904 to be stressed inward, and the blockage of the return culvert 302 is released. When the sealing table 904 is pulled by the steel rope, the return spring 903 pushes the sealing table 904 to be stressed outward, and the return culvert 302 is blocked again.

[0035] It should be further noted that a magnetic adsorption layer is arranged on the blocking seat 901; an electromagnet 905 acting on the blocking seat 901 is arranged in the sand collecting cavity 301.

[0036] It should be further noted that the bottom of the sand collecting cavity 301 is open to communicate with the sand collecting box 6; the opening and closing assembly 9 is mounted above the opening.

[0037] When the water flow flushes and unseats the blocking seat 901 and moves backward, the electromagnet 905 is energized to generate magnetism, fixing the blocking seat 901, reserving enough space for the sand and gravel to enter, and also storing energy for the return spring 903. When the sand flushing is completed and the magnetic attraction ends, the return spring 903 quickly rebounds and resets.

[0038] As Figures 1 - 4 shown, the sand blocking assembly 1 includes a sand blocking seat 101 located between the impact table 2 and the return table 3; sand blocking grooves 102 and sand blocking platforms 103 are alternately arranged on the sand blocking seat 101; the sand blocking grooves 102 and the sand blocking platforms 103 form a sand blocking structure with undulations along an S-shaped trajectory with one concave and one convex; the sand blocking structure communicates with the return culvert 302; the traction member 8 passes through the sand blocking grooves 102; the sand scraping assembly 7 is pulled by the traction member 8 and moves back and forth in the sand blocking grooves 102 to scrape sand.

[0039] Since the sand blocking grooves 102 and the sand blocking platforms 103 form a sand blocking structure with undulations along an S-shaped trajectory with one concave and one convex, it realizes the interception of the sand and gravel carried by the water flow at the water intake of the dam. And after the sand and gravel accumulate to a certain amount, by opening the sand flushing gate 4, a high-speed water flow is formed by using the height difference of the impact table 2 and the water flow pressure, flushing the sediment deposited on the sand blocking seat 101 and discharging it into the return culvert 302, and finally discharging it through the sand outlet pipe 5.

[0040] Embodiment 2, as Figure 7 shown, the sand blocking groove 102 is set as a semi-cylindrical groove, one side of the groove opening corresponds to and communicates with the return culvert 302 one by one, and the other side of the groove opening abuts against the impact table 2; the sand blocking platform 103 is set as a solid pillow shape. The sand scraping cylinder 702 is located in the sand blocking groove 102. The water flow moves along an S-shaped trajectory along the sand blocking groove 102 and the sand blocking platform 103, the sand and gravel are intercepted by the sand blocking platform 103, slide into the sand blocking groove 102, and are finally washed into the return culvert 302.

[0041] As Figure 8 shown, the sand scraping assembly 7 includes two groups of positioning heads 701 arranged in pairs on the traction member 8; the sliding sleeve 706 is slidably sleeved on the traction member 8 and is located between the two groups of positioning heads 701. An elastic telescopic sleeve 707 that wraps the traction member 8 is arranged between the sliding sleeve 706 and the positioning heads 701 on both sides, and a rotatable sand scraping cylinder 702 is arranged on the outer periphery of the sliding sleeve 706.

[0042] It should be further noted that the sand scraping cylinder 702 is provided with a hollow 705 for the water flow to pass through, a pushing paddle 704 is arranged on one side of the hollow 705, and a sand scraping frame 703 is arranged on the side wall of the sand scraping cylinder 702.

[0043] When the gate 401 rises, the end of the steel rope rises and extends along the deflection roller II 402 and the deflection roller I 202. At this time, the sand scraping assembly 7 is washed by the water flow and moves towards the return culvert 302. During the movement, the sand scraping cylinder 702 drives the elastic telescopic sleeves 707 on both sides to bounce back and forth, and at the same time, the water flow impacts and rotates. Through the hollow 705, the pushing paddle 704 is forced, which can drive the sand scraping cylinder 702 to rotate, and the sand scraping frame 703 rotates to scrape the sand and gravel attached to the sand retaining structure, accelerating its entry into the return culvert 302.

[0044] Embodiment 3, as Figure 9 shown, the sand retaining groove 102 is set as a semi-cylindrical groove, one side of the groove mouth is in one-to-one correspondence and communication with the return culvert 302, and the other side of the groove mouth abuts against the impact platform 2; the sand retaining platform 103 is set as a hollow pillow-shaped structure, and a sand inlet 104 communicating with the sand retaining groove 102 is arranged at the bottom of the water-facing side, and a sand storage cavity 105 is arranged inside; the sand storage cavity 105 gradually becomes smaller from top to bottom and communicates with the sand inlet 104 at the bottom; the sand scraping cylinder 702 is located in the sand retaining groove 102.

[0045] The water flow moves along the sand retaining groove 102 and the sand retaining platform 103 in an S-shaped trajectory. The sand and gravel are intercepted by the sand retaining platform 103, slide into the sand retaining groove 102 and the sand storage cavity 105, and are finally washed into the return culvert 302. The setting of the sand storage cavity 105 not only increases the capacity for accommodating sand and gravel, but also reduces the impact of sand and gravel on hydropower generation and reduces the frequency of sand flushing.

[0046] As Figure 10 shown, the sand scraping assembly 7 includes two groups of positioning heads 701 arranged in pairs on the traction member 8; the sliding sleeve 706 is slidably sleeved on the traction member 8 and is located between the two groups of positioning heads 701. Elastic telescopic sleeves 707 wrapping the traction member 8 are arranged between the sliding sleeve 706 and the positioning heads 701 on both sides, and a rotatable sand scraping cylinder 702 is arranged on the outer periphery of the sliding sleeve 706.

[0047] It should be further noted that the sand scraping cylinder 702 is provided with a hollow 705 for water flow to pass through. A pushing paddle 704 is arranged on one side of the hollow 705, and a sand scraping frame 703 is arranged on the side wall of the sand scraping cylinder 702.

[0048] It should be further noted that the sand scraping assembly 7 further includes a sand discharging ball 10; the sand discharging ball 10 is movably arranged in the sand storage cavity 105 and is larger than the sand inlet 104. The sand discharging ball 10 is connected to the sliding sleeve 706 through a connecting chain 11.

[0049] In daily operation, the sand discharging ball 10 is lifted by the water flow and floats on the top of the sand storage cavity 105. When the sliding sleeve 706 slides, it drives the sand discharging ball 10 to move synchronously, and by pulling the sand discharging ball 10 to move in the sand storage cavity 105, it assists in discharging the sand and gravel from the sand storage cavity 105.

[0050] The working principle of the sand flushing device for hydropower generation in the present invention is as follows: The gate 401 is normally closed, and the plugging seat 901 blocks the return culvert 302 under the action of the return spring 903. During the process that the water flow at the water intake of the dam drives the sand and gravel to move along the sand retaining structure with a high and low undulating S-shaped trajectory, the sand and gravel are intercepted by the sand retaining platform 103 and slide into the sand retaining groove 102 and the sand storage cavity 105. When the sand and gravel accumulate to a certain amount, the gate 401 is lifted. The height difference of the impact platform 2 and the water flow pressure form a high-speed water flow. The end of the steel rope rises, and the tail extends along the second deflecting roller 402 and the first deflecting roller 202. On the one hand, the sealing platform 904 is released by the steel rope. The water flow impact causes the sealing platform 904 to be stressed inward, releasing the plugging of the return culvert 302. The electromagnet 905 is energized to generate magnetism, fixing the plugging seat 901 to reserve enough space for the sand and gravel to enter. The sand and gravel are flushed into the return culvert 302. On the other hand, the sand scraping assembly 7 is washed by the water flow and moves towards the return culvert 302. During the movement, the sand scraping cylinder 702 drives the back-and-forth bouncing through the elastic telescopic sleeves 707 on both sides. At the same time, the water flow impacts and rotates. Passing through the hollow 705, the paddle 704 is forced, which can drive the sand scraping cylinder 702 to rotate, and the sand scraping frame 703 rotates to scrape the sand and gravel attached to the sand retaining structure. At the same time, when the sliding sleeve 706 slides, it drives the sand discharging ball 10 to move synchronously, and the sand discharging ball 10 is pulled to move in the sand storage cavity 105 to assist the sand and gravel to enter the return culvert 302 from the sand storage cavity 105 and the sand retaining groove 102. Finally, the sand and gravel are discharged from the sand discharging pipe 5. The gate 401 descends and closes, and the plugging seat 901 resets to block the return culvert 302, and the hydropower generation continues.

[0051] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes can be made without departing from the spirit of the present invention within the scope of knowledge possessed by those skilled in the art.

Claims

1. A sand flushing device for hydropower generation, characterized in that: include: A sand-blocking assembly (1), which is arranged on the water intake of the dam along the direction of the water flow, and intercepts sand and gravel in the water flow by forming an undulating trend; An impact platform (2), the impact platform (2) is located on one side of the sand blocking component (1), and a sand flushing gate (4) for horizontal water flushing is arranged on the top; A reflow platform (3), the reflow platform (3) is located on the other side of the sand blocking assembly (1), a reflow culvert (302) connected to the sand blocking assembly (1) is arranged on the side wall, and a sand collecting box (6) connected to the reflow culvert (302) and the sand outlet pipe (5) is arranged at the bottom; an opening and closing assembly (9) for blocking the reflow culvert (302) is also arranged on the reflow platform (3); A traction member (8), one end of the traction member (8) is connected to the gate (401) of the sand flushing gate (4), and the other end is connected to the opening and closing assembly (9); when the gate (401) rises, the traction member (8) is extended, and the opening and closing assembly (9) opens the return culvert (302); when the gate (401) falls, the traction member (8) is shortened, and the opening and closing assembly (9) closes the return culvert (302); And a sand scraping assembly (7), which is connected in series to the traction member (8) and moves back and forth on the sand blocking assembly (1) to scrape sand as the traction member (8) is extended or shortened and the water flow scours.

2. The sand flushing device for hydropower generation according to claim 1, characterized in that: An installation cavity (201) is arranged inside the impact platform (2); a first direction-changing roller (202) is arranged inside the installation cavity (201); a second direction-changing roller (402) is arranged on the frame of the sand flushing gate (4); one end of the traction member (8) is connected to the top of the gate (401), and the other end is connected to the second direction-changing roller (402) and the first direction-changing roller (202) in sequence, then passes through the sand blocking component (1), extends into the return culvert (302), and is connected to the opening and closing component (9).

3. The sand flushing device for hydropower generation according to claim 1, characterized in that: A sand collecting chamber (301) is provided inside the reflow platform (3) and is connected to the reflow culvert (302) and the sand collecting box (6); The opening and closing assembly (9) comprises a telescopic rod (902) located in the sand collecting chamber (301); the end of the telescopic rod (902) extends into the reflux culvert (302) and is connected to the blocking seat (901); a return spring (903) is sleeved on the outside of the telescopic rod (902); and a sealing platform (904) matching the reflux culvert (302) is provided at the front end of the blocking seat (901); The end of the traction member (8) is connected to the sealing platform (904).

4. The sand flushing device for hydropower generation according to claim 3, characterized in that: A magnetic attraction layer is arranged on the blocking seat (901); and an electromagnet (905) for acting on the blocking seat (901) is arranged in the sand collecting chamber (301).

5. The sand flushing device for hydropower generation according to claim 1, characterized in that: The sand-trapping assembly (1) comprises a sand-trapping seat (101) located between an impact platform (2) and a return flow platform (3); the sand-trapping seat (101) is provided with sand-trapping grooves (102) and sand-trapping platforms (103) alternately; the sand-trapping grooves (102) and the sand-trapping platforms (103) are concave and convex to form a sand-trapping structure that fluctuates along an S-shaped trajectory; the sand-trapping structure is connected to a return flow culvert (302); The traction member (8) passes through the sand retaining groove (102); the sand scraping assembly (7) is pulled by the traction member (8) and moves back and forth in the sand retaining groove (102) to scrape sand.

6. The sand flushing device for hydropower generation according to claim 5, characterized in that: The sand scraping assembly (7) comprises two groups of positioning heads (701) arranged in pairs on the traction member (8); a sliding sleeve (706) is slidably sleeved on the traction member (8) and is located between the two groups of positioning heads (701); an elastic telescopic sleeve (707) covering the traction member (8) is arranged between the sliding sleeve (706) and the positioning heads (701) on both sides; and a rotatable sand scraping cylinder (702) is arranged on the outer periphery of the sliding sleeve (706).

7. The sand flushing device for hydropower generation according to claim 6, characterized in that: The sand scraping cylinder (702) is provided with a hollow (705) for water flow to pass through, a push paddle (704) is provided on one side of the hollow (705), and a sand scraping frame (703) is provided on the side wall of the sand scraping cylinder (702).

8. The sand flushing device for hydropower generation according to claim 6, characterized in that: The sand retaining groove (102) is configured as a semi-cylindrical groove, one side of which is connected to the return culvert (302) in a one-to-one correspondence, and the other side of which is against the impact platform (2); The sand trap (103) is configured as a solid pillow type; The sand scraping cylinder (702) is located in the sand retaining groove (102).

9. The sand flushing device for hydropower generation according to claim 6, characterized in that: The sand retaining groove (102) is configured as a semi-cylindrical groove, one side of which is connected to the return culvert (302) in a one-to-one correspondence, and the other side of which is against the impact platform (2); The sand retaining platform (103) is configured as a hollow pillow-shaped structure, a sand inlet (104) connected to the sand retaining groove (102) is configured at the bottom of the water-facing side, and a sand storage cavity (105) is configured inside; the sand storage cavity (105) gradually becomes smaller from top to bottom, and the bottom is connected to the sand inlet (104); The sand scraping cylinder (702) is located in the sand retaining groove (102).

10. The sand flushing device for hydropower generation according to claim 9, characterized in that: The sand scraping assembly (7) further comprises a sand discharge ball (10); the sand discharge ball (10) is movably arranged in the sand storage chamber (105) and is larger than the sand inlet (104); the sand discharge ball (10) is connected to the sliding sleeve (706) via a connecting chain (11).

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