A pumped storage power station based on an underground reservoir

Abstract

The present invention provides a pumped-storage power station based on an underground reservoir, comprising an above-ground reservoir and an underground reservoir. A reversible water pump and worm turbine unit is disposed underground between the above-ground reservoir and the underground reservoir. An upper outlet pipe and an upper inlet pipe are respectively disposed on the side slope of the above-ground reservoir. The other ends of the upper outlet pipe and the upper inlet pipe are connected to a water diversion pipeline via a three-way ball valve. The other end of the water diversion pipeline is connected to the turbine inlet and water pump outlet of the reversible water pump and worm turbine unit via a branch and is also provided with a ball valve. By placing the lower reservoir underground, the ground occupation can be reduced, making it particularly suitable for areas with limited land resources. The underground reservoir can flexibly adapt to various terrains, such as near rivers, lakes, or the seaside, without relying on natural height differences, thereby expanding the site selection range of the pumped-storage power station.

Description

Technical Field

[0001] The present invention relates to the field of pumped storage power stations, and in particular to a pumped storage power station based on an underground reservoir. Background Art

[0002] With the growth of global energy demand and the development of renewable energy, pumped-storage hydropower plants (PSPs) have been widely adopted worldwide as a highly efficient method of energy storage and regulation. The basic principle of a PSP is to use excess electricity to pump water from a lower reservoir to a higher reservoir for storage during periods of low electricity demand. During peak periods of electricity demand, water is released from the higher reservoir to drive turbine generators for power generation, helping to balance grid loads and improve overall power system stability.

[0003] Despite the many advantages of pumped storage technology, traditional pumped storage power station designs also face some inherent challenges and limitations. Pumped storage power stations require the construction of two large reservoirs, namely a high-level reservoir and a low-level reservoir, which requires a large amount of land resources. At the same time, the two large reservoirs will also affect the surrounding ecological environment. In addition, the successful construction of pumped storage power stations is highly dependent on geographical conditions. There must be a sufficient height difference to ensure the head height, and suitable geological structures are also required to support the construction and operation of the reservoirs. Such conditions limit the construction site of pumped storage power stations. Therefore, a pumped storage power station based on underground reservoirs is proposed to solve the above problems. Summary of the Invention

[0004] The main purpose of the present invention is to provide a pumped storage power station based on an underground reservoir to solve the problems that two large reservoirs require a large amount of land resources, are highly dependent on geographical conditions and affect the surrounding ecological environment.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is as follows: a pumped storage power station based on an underground reservoir, comprising an above-ground reservoir and an underground reservoir, wherein an underground reversible water pump and worm turbine unit is provided between the above-ground reservoir and the underground reservoir, an upper water outlet pipe and an upper water inlet pipe are respectively provided on the side slope of the above-ground reservoir, the other ends of the upper water outlet pipe and the upper water inlet pipe are connected to a water diversion pipeline through a three-way ball valve, the other end of the water diversion pipeline is connected to the turbine inlet end and the water pump outlet end of the reversible water pump and worm turbine unit through a branch, and a ball valve is provided, the water turbine outlet end of the reversible water pump and worm turbine unit is connected to the upper part of the underground reservoir through a lower water outlet pipe, and the water pump inlet end is connected to the bottom end of the underground reservoir through a lower water inlet pipe;

[0006] Among them, the connecting ends of the upper water outlet pipe and the above-ground reservoir, and the connecting ends of the lower water outlet pipe and the underground reservoir are both equipped with one-way valves, and the connecting ends of the upper water inlet pipe and the above-ground reservoir, and the connecting ends of the lower water inlet pipe and the underground reservoir are both equipped with opening and closing valves.

[0007] In the preferred embodiment, the middle sections of the upper water inlet pipe and the lower water inlet pipe are both provided with overflow filter tanks for filtering and buffering.

[0008] In the preferred embodiment, the overflow filter tank includes a box body, in which a partition wall is provided, which divides the interior of the box body into a filter chamber and a water collection chamber. An overflow space is reserved between the partition wall and the inner top wall of the box body, and a filter grille covering the filter chamber is provided between the partition wall and the inner wall of the box body. The filter grille is inclined toward the water collection chamber, and the bottoms on both sides of the overflow filter tank are respectively connected to the filter chamber and the water collection chamber with an overflow inlet pipe and an overflow outlet pipe.

[0009] In the preferred embodiment, a sand settling trough is further provided at the bottom of the filter chamber, a sewage pipe connected to the bottom of the sand settling trough is provided on the side of the box body, and the inner bottom wall of the sand settling trough is inclined toward the sewage pipe.

[0010] In the preferred embodiment, the sand settling tank is located directly below the water inlet end of the overflow water inlet pipe, and a guide slope inclined toward it is provided on the bottom wall of the filter chamber above the sand settling tank.

[0011] In a preferred embodiment, a connected energy dissipation step is further provided on the inner bottom wall of the water collecting chamber, and the lower side of the energy dissipation step is close to the direction of the overflow outlet pipe.

[0012] In the preferred embodiment, a closed gate is provided through the top of the box body, which closes the overflow space between the partition wall and the box body, an opening and closing gate is provided in the overflow outlet pipe, and a backwash device for cleaning the filter grid is provided between the filter chamber and the water collection chamber.

[0013] In the preferred embodiment, a cavity is provided inside the energy dissipation step, and a connecting groove communicating with the cavity is provided on the side of the step at the lowest end, and a filter plate is provided in the connecting groove;

[0014] The backwash device includes a water supply system arranged in the water collection chamber and a mobile backwash system located above the filter grid;

[0015] The water supply system includes a water pump arranged in the cavity, a water supply pipe is provided at the water outlet of the water pump, and the other end of the water supply pipe passes through the energy dissipation ladder and the box body, bypasses the closed gate and passes into the box body;

[0016] The mobile backflushing system includes a baffle arranged on the top wall of the box body, two limit slide rails and a rotatable screw are arranged between the baffle and the inner side wall of the box body, the length of the limit slide rail and the screw is adapted to the filter grid, and a transverse seat is provided on the outside of the screw and the two limit slide rails, the transverse seat is slidably connected to the two limit slide rails and is threadedly connected to the screw, a support platform is arranged on the outside of the box body, and a driving device with an output end connected to the screw is arranged on the support platform, a water pipe is arranged at the bottom of the transverse seat, a plurality of backflushing nozzles are arranged at the bottom of the water pipe, and a delivery hose is connected between the water supply pipe and the water inlet end of the water pipe.

[0017] In the preferred embodiment, a water pipe slide rail is provided on the inner top wall of the box body, a plurality of pulleys are provided on the water pipe slide rail, the delivery hose is helically hoisted on the plurality of pulleys, and the pulleys fix the delivery hose through pipe clamps.

[0018] The preferred solution also includes a traffic and ventilation passage extending from the ground to the underground reservoir and the reversible water pump worm turbine unit.

[0019] The present invention provides a pumped-storage power station based on an underground reservoir. By placing the lower reservoir underground, the ground occupation can be reduced, making it particularly suitable for areas with limited land resources. The underground reservoir can flexibly adapt to a variety of terrains, such as near rivers, lakes, or the seaside, without relying on natural elevation differences, thereby expanding the site selection range of pumped-storage power stations. In addition, underground construction is less damaging to the ecological environment and does not require large-scale landform changes like traditional above-ground reservoirs, reducing interference with the surrounding ecosystem. The underground reservoir does not affect the ground landscape, avoiding the potential safety hazards such as collapse caused by above-ground reservoirs. At the same time, underground reservoirs can also significantly reduce water evaporation, especially in arid or hot areas, helping to maintain the stability of water resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below with reference to the accompanying drawings and examples:

[0021] Figure 1 It is a schematic cross-sectional view of the overall structure of the present invention;

[0022] Figure 2 It is a schematic structural diagram of the overflow filter tank of the present invention;

[0023] Figure 3 This is a schematic diagram of a half-section structure of an overflow filter tank of the present invention;

[0024] Figure 4 This invention Figure 3 Schematic diagram from another perspective;

[0025] Figure 5 This invention Figure 3 Front view of

[0026] Figure 6 This is a schematic diagram of a half-section structure of the energy dissipation ladder of the present invention;

[0027] Figure 7 is an independent schematic diagram of the backwash device of the present invention;

[0028] Figure: Aboveground reservoir 1; underground reservoir 2; reversible water pump worm turbine unit 3; water diversion pipeline 4; overflow filter tanks 5, 6; housing 500; partition wall 501; overflow inlet pipe 502; overflow outlet pipe 503; guide slope 504; energy dissipation ladder 505; cavity 5050; connecting trough 5051; sedimentation trough 506; sewage pipe 507; filter grille 508; closing gate 509; backwash pipe 510 ; Water pump 5100; Water supply pipe 5101; Delivery hose 5102; Water guide pipe 5103; Baffle 5104; Limit slide rail 5105; Screw 5106; Transverse seat 5107; Support platform 5108; Drive device 5109; Water pipe slide rail 5110; Backflush nozzle 5111; Ventilation channel 7; Upper water outlet pipe 8; Upper water inlet pipe 9; Three-way ball valve 10; Lower water outlet pipe 11; Lower water inlet pipe 12. DETAILED DESCRIPTION

[0029] Example 1

[0030] like Figure 1 As shown, a pumped storage power station based on an underground reservoir includes an above-ground reservoir 1 and an underground reservoir 2. The distance and height difference between the above-ground reservoir 1 and the underground reservoir 2 should meet the requirements of the pipeline inclination angle, length, etc. A reversible water pump worm turbine unit 3 located underground is provided between the above-ground reservoir 1 and the underground reservoir 2. The reversible water pump worm turbine unit 3 is a commonly used technical means in this field, so it will not be described in detail here. An upper water outlet pipe 8 and an upper water inlet pipe 9 are respectively provided on the side slope of the above-ground reservoir 1. The upper water outlet pipe 8 and the upper water inlet pipe 9 are respectively used to pump water into or out of the above-ground reservoir 1, the other ends of the upper water outlet pipe 8 and the upper water inlet pipe 9 are connected to the water diversion pipe 4 through a three-way ball valve 10. The other end of the water diversion pipe 4 is connected to the turbine water inlet end and the water pump outlet end of the reversible water pump worm turbine unit 3 through a branch, and is provided with a ball valve for controlling the switch of the corresponding pipeline. The turbine water outlet end of the reversible water pump worm turbine unit 3 is connected to the top of the underground reservoir 2 through the lower water outlet pipe 11, and the water pump inlet end is connected to the bottom end of the underground reservoir 2 through the lower water inlet pipe 12. The lower water outlet pipe 11 and the lower water inlet pipe 12 are respectively used to introduce water into or pump water out of the underground reservoir 2.

[0031] Among them, the connecting end between the upper water outlet pipe 8 and the above-ground reservoir 1, and the connecting end between the lower water outlet pipe 11 and the underground reservoir 2 are both provided with a one-way valve, and the connecting end between the upper water inlet pipe 9 and the above-ground reservoir 1, and the connecting end between the lower water inlet pipe 12 and the underground reservoir 2 are both provided with an opening and closing valve.

[0032] During power generation, water from the above-ground reservoir 1 enters the underground reservoir 2 through the upper water inlet pipe 9, the water diversion pipeline 4, the turbine of the reversible water pump and worm turbine unit 3, and the lower water outlet pipe 11. During this process, electricity is generated by the water passing through the turbine of the reversible water pump and worm turbine unit 3.

[0033] During pumping energy storage, the water pump of the reversible water pump turbine unit 3 pumps water out of the underground reservoir 2 through the lower water inlet pipe 12 and pumps the water into the aboveground reservoir 1 through the water diversion pipe 4 and the upper water outlet pipe 8.

[0034] In the above process, the valves in all pipelines are switched on and off accordingly.

[0035] This design reduces ground occupation by setting the reservoir underground, which is especially suitable for areas with tight land resources. At the same time, underground reservoirs can flexibly adapt to various terrains, such as near rivers, lakes or the seaside, without having to look for natural terrain with height differences, greatly expanding the site selection range of pumped storage power stations. In addition, underground construction causes less damage to the ecological environment and does not require large-scale changes to the landform like traditional above-ground reservoirs, reducing interference with the surrounding ecosystem. Secondly, underground reservoirs are located underground, which usually does not affect the beauty of the landscape and can avoid safety hazards such as collapse that may occur in above-ground reservoirs. Underground reservoirs are located underground, which can significantly reduce water evaporation, especially in arid or hot areas, and can better maintain the stability of water resources.

[0036] In addition, this embodiment adopts a combination of a single water diversion pipeline 4 and high and low separation inlets and outlets. The high and low separation of the upper water outlet pipe 8 and the upper water inlet pipe 9, the lower water outlet pipe 11 and the lower water inlet pipe 12 make the water flow more stable when passing through, which can effectively reduce water flow interference, reduce the cavitation phenomenon caused by the back and forth flow of the single pipe when entering and exiting, and extend its service life. At the same time, the water flow path is optimized by gravity to reduce the risk of backflow. It reduces pressure fluctuations in the system and improves the operational stability of the system, especially when the load changes rapidly. Secondly, maintenance is more convenient. A part of the system can be inspected and repaired while it is running without affecting the overall operation, reducing downtime. In addition, compared with directly setting two separate water diversion pipelines 4, its construction difficulty and cost are lower. The separately set upper water inlet pipe 9 and lower water inlet pipe 12 also facilitate the setting of a filtering structure, effectively preventing pipe blockage.

[0037] It should be noted that the underground reservoir 2 in this embodiment can be constructed by slope excavation engineering.

[0038] Example 2

[0039] Further illustrate with reference to Example 1, Figure 2-4In the structure shown, the middle sections of the upper water inlet pipe 9 and the lower water inlet pipe 12 are both provided with overflow filter tanks 5, 6 for filtering and buffering. The two overflow filter tanks 5, 6 can achieve a double filtering effect. At the same time, they can effectively buffer the impact of water flow at the corresponding inlet, eliminate excess kinetic energy in the water flow, prevent vortexes, cavitation and other phenomena, and avoid direct damage to pipelines and equipment.

[0040] In the preferred embodiment, the overflow filter tank 5, 6 includes a box body 500, and the actual size of the box body 500 can be adjusted according to the needs of water flow speed and amount. A partition wall 501 is provided in the box body 500, and the partition wall 501 divides the interior of the box body 500 into a filter chamber and a water collection chamber. An overflow space is reserved between the partition wall 501 and the inner top wall of the box body 500, and a filter grille 508 covering the filter chamber is provided between the upper part and the inner wall of the box body 500. The filter grille 508 is inclined toward the water collection chamber. The inclined design facilitates reducing obstruction to water and improving the efficiency of water passage. The bottoms on both sides of the overflow filter tank 5, 6 are respectively connected to the overflow inlet pipe 502 and the overflow outlet pipe 503 of the filter chamber and the water collection chamber, which are used to be connected to the upper water inlet pipe 9 or the lower water inlet pipe 12.

[0041] With such an arrangement, water can enter the filter chamber of the box body 500 through the overflow inlet pipe 502, and flow into the water collection chamber after passing through the filter grille 508 by overflow, and finally flow out through the overflow outlet pipe 503. In this process, the water body can be filtered to prevent impurities from directly entering the pipeline and causing blockage of the pipeline. At the same time, in this process, it can buffer the impact of water flow and prevent the occurrence of vortexes, cavitation and other phenomena.

[0042] It should be noted that the dimensions of the filter chambers and water collection chambers of the overflow filter pools 5, 6, the aperture of the filter grid 508, and the water inlet and outlet volumes of the overflow inlet pipe 502 and the overflow outlet pipe 503 should meet the normal water flow operation requirements of the pumped storage power station.

[0043] In the preferred embodiment, the overflow outlet pipe 503, the lower water inlet pipe 12 and the upper water inlet pipe 9 are all of a gradient structure, that is, wider at the inlet and gradually narrower at the outlet, which can increase the water flow speed, reduce pressure loss, and prevent air from entering.

[0044] In the preferred embodiment, a sand settling trough 506 is further provided at the bottom of the filter chamber, and a sewage pipe 507 connected to the bottom of the sand settling trough 506 is provided on the side of the box body 500, and the inner bottom wall of the sand settling trough 506 is inclined toward the sewage pipe 507. The sand settling trough 506 can collect mud and sand in the water by gravity and discharge it through the sewage pipe 507.

[0045] It should be noted that a control valve is provided at the connection between the sand settling tank 506 and the sewage pipe 507 in order to adjust the water flow speed and flow rate to ensure the sand settling effect.

[0046] In the preferred embodiment, the sand settling trough 506 is located directly below the water inlet end of the overflow inlet pipe 502, and a guide slope 504 inclined toward it is provided on the bottom wall of the filter chamber above the side of the sand settling trough 506. The guide slope 504 can prevent mud and sand from accumulating thereon and can serve to guide it toward the sand settling trough 506.

[0047] In the preferred embodiment, a connected energy dissipation step 505 is also provided on the inner bottom wall of the water collection chamber. The lower side of the energy dissipation step 505 is close to the overflow outlet pipe 503. The water flow gradually slows down when passing through, and the energy is dispersed, preventing turbulence from causing impact and improving the service life of the equipment.

[0048] Example 3

[0049] Further illustrate with reference to Examples 1 and 2, as Figure 2-7 In the structure shown, in order to facilitate the cleaning of the filter grille, a closed gate 509 is provided through the top of the box body 500. The closed gate 509 can close the overflow space between the partition wall 501 and the box body 500. An opening and closing gate is provided in the overflow outlet pipe 503. A backwashing device 510 for cleaning the filter grille 508 is provided between the filter chamber and the water collection chamber.

[0050] With such an arrangement, when the overflow filter tanks 5 and 6 are not in use, the overflow space can be closed by using the closed gate 509. At this time, the overflow outlet pipe 503 and the overflow inlet pipe 502 stop the flow of water in and out through the closed opening and closing gates respectively, and clean water that has not been discharged is retained in the water collection chamber. Therefore, the backwashing device 510 can be used to backwash the filter grid 508 and the sand settling tank 506, and impurities can be discharged through the sewage pipe 507 to avoid blockage and affect the water flow rate. At the same time, in conjunction with Example 1, the unused part can be backwashed when the system is running without affecting the overall operation, thereby reducing downtime.

[0051] Among them, a cavity 5050 is provided inside the energy dissipation step 505, and a connecting groove 5051 connected to the cavity 5050 is provided on the side of the step at the lowest end. A filter plate is provided in the connecting groove 5051. The water in the water collection chamber can flow through the cavity 5050 and itself through the connecting groove 5051, and the filter plate can achieve a further filtering effect.

[0052] The backwash device 510 includes a water supply system disposed in the water collection chamber and a mobile backwash system located above the filter screen 508 .

[0053] The water supply system includes a water pump 5100 arranged in the cavity 5050, so that the energy dissipation step 505 can be used to protect the water pump 5100 to prevent it from being damaged by water erosion for a long time. A water supply pipe 5101 is provided at the water outlet end of the water pump 5100. The other end of the water supply pipe 5101 passes through the energy dissipation step 505 and the box body 500, bypasses the closed gate 509 and passes into the box body 500.

[0054] With such a design, the water pump 5100 can be used to deliver the water retained in the water collection chamber to the mobile backflushing system through the water supply pipe 5101, thereby achieving a reuse effect.

[0055] The mobile backflushing system includes a baffle 5104 arranged on the top wall of the box body 500, two limiting slide rails 5105 and a rotatable screw 5106 are arranged between the baffle 5104 and the inner wall of the box body 500, the screw 5106 is rotatably arranged between the baffle 5104 and the inner wall of the box body 500 through a bearing, the limiting slide rails 5105 and the screw 5106 are arranged along the length direction of the filter grille 508, and their lengths are adapted to the filter grille 508, and the screw 5106 and the two limiting slide rails 5105 are externally sheathed with a transverse seat 5107, which is horizontally movable. The moving seat 5107 is slidably connected to the two limiting slide rails 5105 and is threadedly connected to the screw 5106. A support platform 5108 is set on the outside of the box body 500. A driving device 5109 is set on the support platform 5108, and the output end is connected to the screw 5106. The driving device 5109 is connected by a driving motor and a reducer. A water pipe 5103 is set at the bottom of the transverse moving seat 5107, and a plurality of recoil nozzles 5111 are set at the bottom of the water pipe 5103. A delivery hose 5102 is connected between the water supply pipe 5101 and the water inlet end of the water pipe 5103.

[0056] With such a design, the screw 5106 can be driven to rotate by the driving device 5109, so that the transverse displacement seat 5107 can move laterally under the restriction of the two limit slide rails 5105. Therefore, through the forward and reverse rotation of the driving device 5109, the water pipe 5103 and the backwash nozzle 5111 thereon can be driven to move back and forth above the filter grille 508, thereby achieving the backwash cleaning effect. The length of the delivery hose 5102 should meet the distance requirement of the water pipe 5103 movement.

[0057] In the preferred embodiment, a water pipe slide 5110 is provided on the inner top wall of the box body 500, and a plurality of pulleys are provided on the water pipe slide 5110. The delivery hose 5102 is spirally hoisted on the plurality of pulleys to reduce bending when they are close to each other. The pulley fixes the delivery hose 5102 through a pipe clamp, so that the water pipe slide 5110 can be used to hoist the delivery hose 5102 on the inner top wall of the box body 500. At the same time, the pulley can be moved sequentially by the traction effect when the water pipe 5103 moves. The water pipe slide 5110 and the pulley can use a wire slide structure, which is a mature existing technology and will not be described in detail here.

[0058] It should be noted that before backwashing, the water in the filter chamber needs to be discharged through the drain pipe 507. The mobile backwash system needs to be waterproofed. The overflow filter tanks 5 and 6 are installed in a space accessible to personnel. There is also an inspection and cleaning door on the box 500 to facilitate construction personnel to enter for maintenance. The closed gate 509 is a common automatic gate on the market, so it will not be described in detail here.

[0059] In the preferred embodiment, a traffic and ventilation passage 7 is also included, which extends from the ground to the underground water reservoir 2 and the reversible water pump worm turbine unit 3 .

[0060] The above embodiments are merely preferred technical solutions of the present invention and should not be construed as limiting the present invention. The scope of protection of the present invention shall be the technical solutions set forth in the claims, including equivalent alternatives to the technical features of the technical solutions set forth in the claims. In other words, equivalent alternatives and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A pumped storage power station based on an underground reservoir, characterized by: The invention comprises an above-ground reservoir (1) and an underground reservoir (2), wherein a reversible water pump worm turbine unit (3) is arranged underground between the above-ground reservoir (1) and the underground reservoir (2), an upper water outlet pipe (8) and an upper water inlet pipe (9) are respectively arranged on the side slope of the above-ground reservoir (1), the other ends of the upper water outlet pipe (8) and the upper water inlet pipe (9) are connected to a water diversion pipe (4) through a three-way ball valve (10), the other end of the water diversion pipe (4) is connected to the water turbine inlet end and the water pump outlet end of the reversible water pump worm turbine unit (3) through a branch, and a ball valve is arranged, the water turbine outlet end of the reversible water pump worm turbine unit (3) is connected to the upper part of the underground reservoir (2) through a lower water outlet pipe (11), and the water pump inlet end is connected to the bottom end of the underground reservoir (2) through a lower water inlet pipe (12); Among them, the connecting end of the upper water outlet pipe (8) and the aboveground reservoir (1), and the connecting end of the lower water outlet pipe (11) and the underground reservoir (2) are both provided with a one-way valve, and the connecting point of the upper water inlet pipe (9) and the aboveground reservoir (1), and the connecting point of the lower water inlet pipe (12) and the underground reservoir (2) are both provided with an opening and closing valve; Overflow filter tanks (5, 6) for filtering and buffering are provided in the middle sections of the upper water inlet pipe (9) and the lower water inlet pipe (12); The overflow filter tank (5, 6) comprises a box (500), wherein a partition wall (501) is provided in the box (500), and the partition wall (501) divides the interior of the box (500) into a filter chamber and a water collection chamber. An overflow space is reserved between the partition wall (501) and the inner top wall of the box (500), and a filter grille (508) covering the filter chamber is provided between the partition wall (501) and the inner wall of the box (500). The filter grille (508) is inclined toward the water collection chamber. The bottoms of both sides of the overflow filter tank (5, 6) are respectively connected to the filter chamber and the water collection chamber, with an overflow water inlet pipe (502) and an overflow water outlet pipe (503). An energy dissipation step (505) is also provided on the inner bottom wall of the water collecting chamber, and the lower side of the energy dissipation step (505) is close to the overflow outlet pipe (503); A closed gate (509) is provided through the top of the box body (500), and the closed gate (509) closes the overflow space between the partition wall (501) and the box body (500). An opening and closing gate is provided in the overflow outlet pipe (503). A backwashing device (510) for cleaning the filter grille (508) is provided between the filter chamber and the water collection chamber. A cavity (5050) is provided inside the energy dissipation step (505), and a communication groove (5051) communicating with the cavity (5050) is provided on the side surface of the step at the lowest end, and a filter plate is provided in the communication groove (5051); The backwashing device (510) includes a water supply system arranged in the water collection chamber and a mobile backwashing system located above the filter grid (508); The water supply system includes a water pump (5100) disposed in the cavity (5050). A water supply pipe (5101) is disposed at the water outlet of the water pump (5100). The other end of the water supply pipe (5101) passes through the energy dissipation ladder (505) and the box (500), then bypasses the closed gate (509) and enters the box (500). The mobile backflushing system includes a baffle (5104) arranged on the inner top wall of the box (500), two limiting slide rails (5105) and a rotatable screw (5106) are arranged between the baffle (5104) and the inner side wall of the box (500), the length of the limiting slide rails (5105) and the screw (5106) are adapted to the filter grille (508), and a transverse seat (5107) is sheathed on the outside of the screw (5106) and the two limiting slide rails (5105). The transverse seat (5107) and the two limiting slide rails (5106) are in contact with each other. 105) is slidably connected and threadedly connected to the screw (5106). A support platform (5108) is provided on the outside of the box body (500). A driving device (5109) is provided on the support platform (5108) whose output end is transmission-connected to the screw (5106). A water pipe (5103) is provided at the bottom of the transverse seat (5107). A plurality of recoil nozzles (5111) are provided at the bottom of the water pipe (5103). A delivery hose (5102) is connected between the water supply pipe (5101) and the water inlet end of the water pipe (5103).

2. A pumped storage power station based on an underground reservoir according to claim 1, characterized in that: A sand settling trough (506) is further provided at the bottom of the filter chamber, and a sewage pipe (507) connected to the bottom of the sand settling trough (506) is provided on the side of the box body (500), and the inner bottom wall of the sand settling trough (506) is inclined toward the sewage pipe (507).

3. A pumped storage power station based on an underground reservoir according to claim 2, characterized in that: The sand settling trough (506) is located directly below the water inlet end of the overflow water inlet pipe (502), and a guide slope (504) inclined toward the sand settling trough (506) is provided on the bottom wall of the filter chamber above the side of the sand settling trough (506).

4. A pumped storage power station based on an underground reservoir according to claim 1, characterized in that: A water pipe slide rail (5110) is provided on the inner top wall of the box body (500), and a plurality of pulleys are provided on the water pipe slide rail (5110). The delivery hose (5102) is helically hoisted on the plurality of pulleys, and the pulleys fix the delivery hose (5102) via a pipe clamp.

5. The pumped storage power station based on an underground reservoir according to claim 1, characterized in that: It also includes a traffic and ventilation passage (7) extending from the ground to the underground reservoir (2) and the reversible water pump worm turbine unit (3).

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