Flywheel-equipped gravity energy storage system and control method thereof

Abstract

The application discloses a gravity energy storage system with a flywheel, a gravity block is arranged in a shaft, the lower ends of first and second racks are vertically arranged on the upper side of the gravity block, the upper ends of the first and second racks are connected with a rack lifting driving mechanism and are driven by the rack lifting mechanism, a first flywheel input gear is engaged with one of the first and second racks, a second flywheel input gear is engaged with the other rack, a first flywheel mechanism is coaxially connected with the first flywheel input gear, a second flywheel mechanism is coaxially connected with the second flywheel input gear, and a clutch is arranged in the first and second flywheel mechanisms. The gravity potential energy and the rotational kinetic energy of the flywheel are directly converted, the energy efficiency is improved, the gravity block is started and lifted by directly using the energy stored in the flywheel, quick response can be realized, power compensation in time can be realized, and the problem of impact current caused by frequent start and stop of the gravity energy storage system is solved.

Description

Technical Field

[0001] This invention relates to a gravity energy storage system and its control method, particularly a gravity energy storage system with a flywheel and its control method, belonging to the field of energy storage technology. Background Technology

[0002] The inherent intermittency and volatility of renewable energy sources, primarily wind and solar, are becoming increasingly prominent during grid-connected power generation, easily leading to high wind and solar curtailment rates. Energy storage technology is a crucial solution for improving the absorption and storage capacity of renewable energy. Gravity energy storage is a novel physical energy storage technology. Compared to electrochemical energy storage, gravity energy storage offers advantages such as environmental friendliness, low cost, large scale, long service life, and lack of geographical limitations, making it highly suitable for large-scale renewable energy power storage scenarios. Currently, China Tianying has developed a gravity energy storage technology based on a gravity slider. This technology stores and releases energy by moving a gravity slider up and down using a high-power motor / generator. However, due to the gravity slider's weight of tens of tons, the starting load is high, resulting in frequent start-ups and shutdowns. The instantaneous current during startup is many times that of normal operation, causing current surges on the system busbars. Frequent start-ups and shutdowns also cause grid frequency instability, reducing power quality and affecting the normal operation of other equipment. Furthermore, the inconsistent power output of wind and solar renewable energy sources, with excessive instantaneous power, further exacerbates the damage to the grid. Therefore, solving the surge current problem caused by frequent start-ups and shutdowns of gravity energy storage systems is a key factor in ensuring the stable operation of the power grid.

[0003] Many researchers are attempting to solve this problem. Invention patent CN115441532A proposes a composite gravity energy storage system that combines a gravity energy storage device with a power-type energy storage module. It utilizes supercapacitors, batteries, or flywheel energy storage to provide millisecond-level or faster power input to the grid, thereby compensating for grid fluctuations. Invention patent CN114784830A proposes a comprehensive physical energy storage system combining gravity and a flywheel. This system is equipped with a frequency-regulating flywheel and an energy storage flywheel to perform frequency regulation on the grid to which the energy storage system is connected, and to provide timely power compensation to the grid, thereby improving the safety and stability of grid operation.

[0004] It is clear that the above methods all employ power-type energy storage modules. During the frequent start-ups and shutdowns of the gravity energy storage system, the grid control system provides the grid with millisecond-level high power peaks, thereby compensating for potential current surges. However, these methods are indirect and have low technical efficiency. Furthermore, achieving millisecond-level technical control places very high demands on the grid control system. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a gravity energy storage system with a flywheel and its control method, in which gravitational potential energy and flywheel rotational kinetic energy are directly converted into each other, thereby improving energy efficiency.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] A gravity energy storage system with a flywheel, characterized in that it comprises a vertical shaft, a gravity block, a first rack, a second rack, a rack lifting drive mechanism, a first flywheel mechanism, a second flywheel mechanism, a first flywheel input gear, and a second flywheel input gear. The gravity block is disposed within the vertical shaft. The lower ends of the first and second racks are vertically disposed above the gravity block. The upper ends of the first and second racks are connected to the rack lifting drive mechanism and driven to move vertically upwards and downwards by the rack lifting mechanism. The first flywheel input gear meshes with one of the first and second racks, and the second flywheel input gear meshes with the other of the first and second racks. The first flywheel mechanism is coaxially connected to the first flywheel input gear, and the second flywheel mechanism is coaxially connected to the second flywheel input gear. Clutches are disposed within the first and second flywheel mechanisms.

[0008] Furthermore, the first flywheel mechanism includes a first flywheel, a first flywheel clutch, a first flywheel speed increaser, a first flywheel main shaft, and a first flywheel coupling. The first flywheel is connected to one end of the first flywheel speed increaser via the first flywheel clutch, the other end of the first flywheel speed increaser is connected to one end of the first flywheel main shaft, and the other end of the first flywheel main shaft is connected to the shaft of the first flywheel input gear via the first flywheel coupling.

[0009] Furthermore, the second flywheel mechanism includes a second flywheel, a second flywheel clutch, a second flywheel speed increaser, a second flywheel main shaft, and a second flywheel coupling. The second flywheel is connected to one end of the second flywheel speed increaser via the second flywheel clutch, the other end of the second flywheel speed increaser is connected to one end of the second flywheel main shaft, and the other end of the second flywheel main shaft is connected to the shaft of the second flywheel input gear via the second flywheel coupling.

[0010] Furthermore, the first flywheel is rotatably disposed within the first flywheel sealing housing, and the second flywheel is rotatably disposed within the second flywheel sealing housing. The first flywheel sealing housing and the second flywheel sealing housing are fixed inside the side wall of the shaft, and a vacuum is drawn inside the first flywheel sealing housing and the second flywheel sealing housing.

[0011] Furthermore, the upper side of the gravity block has a first rack groove and a second rack groove that are parallel to each other. The lower end of the first rack is slidably disposed in the first rack groove and is connected to the first rack pushing mechanism. The first rack pushing mechanism drives the rack to slide back and forth along the length direction of the first rack groove. The lower end of the second rack is slidably disposed in the second rack groove and is connected to the second rack pushing mechanism. The second rack pushing mechanism drives the rack to slide back and forth along the length direction of the second rack groove. When switching between charging and releasing states, the first rack pushing mechanism and the second rack pushing mechanism respectively drive the first rack and the second rack to move along the length direction of the first rack groove and the second rack groove, thereby realizing the cross meshing of the first rack and the second rack with the first flywheel input gear and the second flywheel input gear.

[0012] Furthermore, the first rack pushing mechanism and the second rack pushing mechanism adopt electric push rod or lead screw mechanism.

[0013] Furthermore, the upper end of the shaft is provided with a first guide rail and a second guide rail. The upper end of the first rack is slidably disposed in the first guide rail and can move up and down in the first guide rail in the vertical direction. The upper end of the second rack is slidably disposed in the second guide rail and can move up and down in the second guide rail in the setting direction. The first guide rail and the second guide rail are respectively fixed to the upper end of the shaft by guide rail brackets.

[0014] Furthermore, the horizontal thickness of the first guide rail and the second guide rail matches the thickness of the first rack and the second rack, and the horizontal length of the first guide rail and the second guide rail matches the length of the first rack groove and the second rack groove. The first rack can slide along the horizontal length direction of the first guide rail, and the second rack can slide along the horizontal length direction of the second guide rail.

[0015] Furthermore, the rack and pinion lifting drive mechanism includes a wire rope, a winch, a gearbox, and a gravity energy storage motor / generator. One end of the wire rope is connected to the upper ends of the first and second racks, and the other end of the wire rope is mounted on the winch. One end of the winch is connected to the output end of the gearbox, and the input end of the gearbox is connected to the gravity energy storage motor / generator.

[0016] A control method comprising the following steps:

[0017] Set the upper and lower speed limits of the flywheel ω max and ω min Flywheel limit factor r, gravity block rated speed v rate The gravity block needs to adjust its speed v. target ;Measure and record the real-time rotational speed ω0 of the flywheel and the real-time moving speed v0 of the gravity block;

[0018] Gravity energy storage systems have three energy storage modes when entering the energy storage state:

[0019] Energy storage mode 1: When v0=0, the gravity block is at the lowest effective position. The first flywheel clutch and the second flywheel clutch are closed at the same time, connecting the first flywheel and the first flywheel speed increaser, as well as the second flywheel and the second flywheel speed increaser, respectively. The rotational kinetic energy of the first flywheel is transmitted to the second rack through the first flywheel input gear, and the rotational kinetic energy of the second flywheel is transmitted to the first rack through the second flywheel input gear, driving the two racks to lift the gravity block from a stationary state.

[0020] Energy storage mode two: when 0 <v0<v rate At that time, the rack and pinion lifting drive mechanism drives the rack to rise to lift the gravity block, while simultaneously determining the real-time rotational speed ω0 of the flywheel: when rω max <ω0<ω max At that time, the first and second flywheels continue to provide kinetic energy to the gravity block until v0 = v rate The clutches of the first and second flywheel mechanisms disengage, and the two flywheel mechanisms are separated from the gravity energy storage device; when ω min <ω0 <rω max At that time, the clutches of the first and second flywheel mechanisms disengage simultaneously, and the two flywheel mechanisms are separated from the gravity energy storage device.

[0021] Energy storage mode 3: When v0 = v rate Furthermore, when the gravity block rises steadily, it needs to accelerate to v. target The clutches of the first and second flywheel mechanisms change from the disengaged state to the engaged state, ensuring ω min Assuming ω < 0, continue to provide kinetic energy to the rack and pinion lifting drive mechanism until v0 = v target To achieve accelerated energy storage, both clutches are disengaged simultaneously; the rack lifting drive mechanism raises the gravity block to the highest position to achieve energy storage; then the rack pushing mechanism drives the two racks to move relative to each other along the flywheel axis, so that the first rack meshes with the first flywheel input gear, and the second rack meshes with the second flywheel input gear, and is in a state of preparation for energy release;

[0022] Gravity energy storage systems have two energy release modes when entering the energy release state:

[0023] Energy release mode 1: When v0=0, the gravity block is at its highest effective position. The gravity block descends and drives the rack and pinion lifting mechanism to convert rotational kinetic energy into electrical energy through the gravity energy storage generator.

[0024] Release mode two: when v0 = v rate Determine the real-time speed ω0 of the flywheel. min <ω0<ω maxAt this time, the clutches of the first and second flywheel mechanisms simultaneously close, and the first and second flywheel input gears, which mesh with the first and second racks respectively, begin to rotate, transferring rotational kinetic energy to the first and second flywheel mechanisms. Both flywheel mechanisms are in an energy storage state; when ω0 = ω max At this time, the flywheel is fully charged, and the two clutches of the flywheel mechanism are simultaneously disengaged; the gravity block continues to descend to the lowest position, achieving complete energy release. Subsequently, the rack and pinion mechanism drives the two racks to move relative to each other along the flywheel axis, achieving meshing of the first rack and the second flywheel input gear. The second rack and the first flywheel input gear are meshed, and the flywheel is in a pre-energy storage state.

[0025] Compared with the prior art, the present invention has the following advantages and effects:

[0026] 1. This invention directly utilizes the energy stored in the flywheel to start and lift the gravity block, enabling rapid response and timely power compensation;

[0027] 2. The flywheel mechanism of this invention is completely built into the gravity energy storage system. Gravitational potential energy and flywheel rotational kinetic energy are directly converted into each other without the need for mechanical energy to electrical energy conversion. This reduces the energy conversion links and has the advantages of high energy efficiency and safety.

[0028] 3. This invention avoids the matching problem between the rack linear velocity and flywheel speed under physical coupling conditions of the two energy storage methods. It not only solves the inrush current problem caused by frequent start-stop of gravity energy storage system, but also smooths out the fluctuation of intermittent energy output power at different time scales. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of a gravity energy storage system with a flywheel according to the present invention.

[0030] Figure 2 This is a side view of a gravity energy storage system with a flywheel according to the present invention.

[0031] Figure 3 This is a partial schematic diagram of the gravity block of the present invention. Detailed Implementation

[0032] To illustrate in detail the technical solutions adopted by the present invention to achieve the intended technical objectives, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Furthermore, the technical means or technical features in the embodiments of the present invention can be replaced without creative effort. The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0033] like Figure 1 and Figure 2 As shown, a gravity energy storage system with a flywheel according to the present invention includes a vertical shaft 1, a gravity block 2, a first rack 3, a second rack 4, a rack lifting drive mechanism, a first flywheel mechanism, a second flywheel mechanism, a first flywheel input gear 5, and a second flywheel input gear 6. The gravity block 2 is disposed inside the vertical shaft 1. The lower ends of the first rack 3 and the second rack 4 are vertically disposed on the upper side of the gravity block 2. The upper ends of the first rack 3 and the second rack 4 are connected to the rack lifting drive mechanism and are driven to move up and down in the vertical direction by the rack lifting mechanism. The first flywheel input gear 5 meshes with one of the racks of the first rack 3 and the second rack 4, and the second flywheel input gear 6 meshes with the other rack of the first rack 3 and the second rack 4. The first flywheel mechanism is coaxially connected to the first flywheel input gear 5, and the second flywheel mechanism is coaxially connected to the second flywheel input gear 6. Clutches are disposed within the first flywheel mechanism and the second flywheel mechanism. When gravity block 2 descends, energy is directly stored in the flywheel mechanism. Then, when gravity block 2 needs to be lifted, the flywheel provides power to raise it. The gravitational potential energy of gravity block 2 and the rotational kinetic energy of the flywheel mechanism are directly converted into each other, without the need for a conversion from mechanical energy to electrical energy and back to mechanical energy. This reduces energy conversion steps, improves energy efficiency, and avoids the matching problem between the rack linear velocity and flywheel speed under physical coupling conditions between the two energy storage methods. By directly utilizing the energy stored in the flywheel to start and lift the gravity block, a rapid response and timely power compensation can be achieved. This solves the inrush current problem caused by frequent start-stop of the gravity energy storage system and smooths out the fluctuations in intermittent energy output power at different time scales.

[0034] The shaft 1 in this invention can be a shaft excavated underground or a shaft of a building structure built on the ground.

[0035] The first flywheel mechanism includes a first flywheel 7, a first flywheel clutch 8, a first flywheel speed increaser 9, a first flywheel main shaft 10, and a first flywheel coupling 11. The first flywheel 7 is connected to one end of the first flywheel speed increaser 9 via the first flywheel clutch 8. The other end of the first flywheel speed increaser 9 is connected to one end of the first flywheel main shaft 10. The other end of the first flywheel main shaft 10 is connected to the shaft of the first flywheel input gear 5 via the first flywheel coupling 11. The second flywheel mechanism includes a second flywheel 12, a second flywheel clutch 13, a second flywheel speed increaser 14, a second flywheel main shaft 15, and a second flywheel coupling 16. The second flywheel 12 is connected to one end of the second flywheel speed increaser 14 via the second flywheel clutch 13. The other end of the second flywheel speed increaser 14 is connected to one end of the second flywheel main shaft 15. The other end of the second flywheel main shaft 15 is connected to the shaft of the second flywheel input gear 6 via the second flywheel coupling 16.

[0036] The first flywheel 7 is rotatably mounted inside the first flywheel sealing housing 17, and the second flywheel 12 is rotatably mounted inside the second flywheel sealing housing 18. The first flywheel sealing housing 17 and the second flywheel sealing housing 18 are fixed inside the side wall of the shaft 1, and a vacuum is drawn inside the first flywheel sealing housing 17 and the second flywheel sealing housing 18. In addition, brakes are also provided in the first flywheel mechanism and the second flywheel mechanism to ensure the safe operation of the gravity energy storage device.

[0037] like Figure 3 As shown, the upper side of the gravity block 2 has a first rack groove 19 and a second rack groove 20 that are parallel to each other. The lower end of the first rack 3 is slidably disposed in the first rack groove 19 and is connected to the first rack pushing mechanism. The first rack pushing mechanism drives the rack 3 to slide back and forth along the length direction of the first rack groove 19. The lower end of the second rack 4 is slidably disposed in the second rack groove 20 and is connected to the second rack pushing mechanism. The second rack pushing mechanism drives the rack 4 to slide back and forth along the length direction of the second rack groove 20. When switching between charging and releasing states, the first rack pushing mechanism and the second rack pushing mechanism respectively drive the first rack 3 and the second rack 4 to move along the length direction of the first rack groove 19 and the second rack groove 20, so as to realize the cross meshing of the first rack 3 and the second rack 4 with the first flywheel input gear 5 and the second flywheel input gear 6. During the charging and releasing states of gravity block 2, the rack moves up and down along the guide rail. The two racks are arranged alternately with the vertical axis of gravity block 2 as the center. When switching between charging and releasing states, the rack pushing mechanism drives the rack to move along the flywheel axis, realizing the cross meshing of the input gears of the two racks and the two flywheels. The rack pushing mechanism is driven by its own stored electrical energy.

[0038] The first and second rack pushing mechanisms employ electric push rods or lead screw mechanisms. Of course, the rack pushing mechanism is not limited to electric mechanisms; pneumatic and hydraulic drive mechanisms can also be used.

[0039] The upper end of the shaft 1 is provided with a first guide rail 21 and a second guide rail 22. The upper end of the first rack 3 is slidably disposed in the first guide rail 21 and can move up and down in the first guide rail 21 in the vertical direction. The upper end of the second rack 4 is slidably disposed in the second guide rail 22 and can move up and down in the second guide rail 22 in the setting direction. The first guide rail 21 and the second guide rail 22 are respectively fixed to the upper end of the shaft 1 by guide rail brackets 23.

[0040] The horizontal thickness of the first guide rail 21 and the second guide rail 22 matches the thickness of the first rack 3 and the second rack 4. The horizontal length of the first guide rail 21 and the second guide rail 22 matches the length of the first rack groove 19 and the second rack groove 20. The first rack 3 can slide along the horizontal length direction of the first guide rail 21, and the second rack 4 can slide along the horizontal length direction of the second guide rail 22.

[0041] The rack and pinion lifting drive mechanism includes a wire rope 24, a winch 25, a gearbox 26, and a gravity energy storage motor / generator 27. One end of the wire rope 24 is connected to the upper end of the first rack 3 and the second rack 4, and the other end of the wire rope 24 is mounted on the winch 25. One end of the winch 25 is connected to the output end of the gearbox 26, and the input end of the gearbox 26 is connected to the gravity energy storage motor / generator 27.

[0042] A control method comprising the following steps:

[0043] Set the upper and lower speed limits of the flywheel ω max and ω min Flywheel limit factor r, gravity block rated speed v rate The gravity block needs to adjust its speed v. target ; Measure and record the real-time rotational speed ω0 of the flywheel and the real-time moving speed v0 of the gravity block.

[0044] Gravity energy storage systems have three energy storage modes when entering the energy storage state:

[0045] Energy Storage Mode 1: When v0=0, gravity block 2 is in its lowest effective position. The rotational kinetic energy of the flywheel drives gravity block 2, lifting it upwards. Specifically, the first flywheel clutch 8 and the second flywheel clutch 13 are simultaneously engaged, connecting the first flywheel 7 and the first flywheel speed increaser 9, as well as the second flywheel 12 and the second flywheel speed increaser 14, respectively. The rotational kinetic energy of the first flywheel 7 is transmitted to the second rack 4 through the first flywheel input gear 5, and the rotational kinetic energy of the second flywheel 12 is transmitted to the first rack 3 through the second flywheel input gear 6, driving the two racks to lift gravity block 2 from its stationary state.

[0046] Energy storage mode two: when 0 <v0<v rate At that time, the gravity energy storage motor / generator 27 supplies power to drive the winch 25 to rotate, and the winch 25 drives the wire rope 24 to lift the gravity block 2. At the same time, the real-time speed ω0 of the flywheel is determined.

[0047] When rω max <ω0<ω max At that time, the first flywheel 7 and the second flywheel 12 continue to provide kinetic energy to the gravity block 2 until v0 = v rate The clutches of the first and second flywheel mechanisms are disengaged, and the two flywheel mechanisms are separated from the gravity energy storage device.

[0048] When ω min <ω0 <rω max At that time, the clutches of the first and second flywheel mechanisms disengage simultaneously, and the two flywheel mechanisms are separated from the gravity energy storage device.

[0049] Energy storage mode 3: When v0 = v rate Furthermore, when gravity block 2 rises steadily, it needs to accelerate to v. target The clutches of the first and second flywheel mechanisms change from the disengaged state to the engaged state, ensuring ω min Assuming ω < 0, continue to provide kinetic energy to the rack and pinion lifting drive mechanism until v0 = v target To achieve accelerated energy storage, both clutches disengage simultaneously. The rack and pinion lifting drive mechanism raises the gravity block 2 to its highest position, achieving energy storage. Subsequently, the rack and pinion pushing mechanism drives the two racks to move relative to each other along the flywheel axis, enabling the first rack 3 to mesh with the first flywheel input gear 5, and the second rack 4 to mesh with the second flywheel input gear 6, thus entering a state of preparation for energy release.

[0050] Gravity energy storage systems have two energy release modes when entering the energy release state:

[0051] Energy release mode 1: When v0=0, gravity block 2 is in the highest effective position. Gravity block 2 descends and drives the steel wire rope 24 of the rack and pinion lifting drive mechanism. The steel wire rope 24 drives the winch 25 to rotate and converts the rotational kinetic energy into electrical energy through the gravity energy storage motor / generator 27.

[0052] Release mode two: when v0 = v rate Determine the real-time speed ω0 of the flywheel:

[0053] When ω min <ω0<ω max At the same time, the clutches of the first flywheel mechanism and the second flywheel mechanism are closed simultaneously, and the first flywheel input gear 5 and the second flywheel input gear 6, which are respectively meshed with the first rack 3 and the second rack 4, begin to rotate and transfer rotational kinetic energy to the first flywheel mechanism and the second flywheel mechanism. The two flywheel mechanisms are in an energy storage state.

[0054] When ω0 = ω max At this time, the flywheel is fully charged and the two clutches of the flywheel mechanism are simultaneously disengaged; the gravity block 2 continues to descend to the lowest position, achieving complete energy release. Subsequently, the rack pushing mechanism drives the two racks to move relative to each other along the flywheel axis, realizing the meshing of the first rack 3 and the second flywheel input gear 6, and the meshing of the second rack 4 and the first flywheel input gear 5, which are in a pre-energy storage state.

[0055] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A flywheel-equipped gravitational energy storage system, characterized by: The application relates to a vertical shaft, a gravity block, a first rack, a second rack, a rack lifting driving mechanism, a first flywheel mechanism, a second flywheel mechanism, a first flywheel input gear and a second flywheel input gear, wherein the gravity block is arranged in the vertical shaft, the lower ends of the first rack and the second rack are vertically arranged on the upper side of the gravity block, the upper ends of the first rack and the second rack are connected with the rack lifting driving mechanism and are driven to vertically lift by the rack lifting mechanism, the first flywheel input gear is engaged with one of the first rack and the second rack, the second flywheel input gear is engaged with the other one of the first rack and the second rack, the first flywheel mechanism is coaxially connected with the first flywheel input gear, the second flywheel mechanism is coaxially connected with the second flywheel input gear, and clutches are arranged in the first flywheel mechanism and the second flywheel mechanism. The upper side of the gravity block is provided with a first rack sliding groove and a second rack sliding groove which are parallel to each other, the lower end of the first rack is slidingly arranged in the first rack sliding groove and the lower end of the first rack is connected with a first rack pushing mechanism and is driven to slide back and forth along the length direction of the first rack sliding groove by the first rack pushing mechanism, the lower end of the second rack is slidingly arranged in the second rack sliding groove and the lower end of the second rack is connected with a second rack pushing mechanism and is driven to slide back and forth along the length direction of the second rack sliding groove by the second rack pushing mechanism, when the charging and discharging states are switched, the first rack pushing mechanism and the second rack pushing mechanism respectively drive the first rack and the second rack to move along the length direction of the first rack sliding groove and the second rack sliding groove, and the first rack and the second rack are engaged with the first flywheel input gear and the second flywheel input gear.

2. A gravity power storage system with flywheel according to claim 1, characterized in that: The first flywheel mechanism comprises a first flywheel, a first flywheel clutch, a first flywheel speed increaser, a first flywheel main shaft and a first flywheel coupling, the first flywheel is connected with one end of the first flywheel speed increaser through the first flywheel clutch, the other end of the first flywheel speed increaser is connected with one end of the first flywheel main shaft, and the other end of the first flywheel main shaft is connected with the rotating shaft of the first flywheel input gear through the first flywheel coupling.

3. A gravity power storage system with flywheel according to claim 1, characterized in that: The second flywheel mechanism comprises a second flywheel, a second flywheel clutch, a second flywheel speed increaser, a second flywheel main shaft and a second flywheel coupling, the second flywheel is connected with one end of the second flywheel speed increaser through the second flywheel clutch, the other end of the second flywheel speed increaser is connected with one end of the second flywheel main shaft, and the other end of the second flywheel main shaft is connected with the rotating shaft of the second flywheel input gear through the second flywheel coupling.

4. A gravity power storage system with flywheel according to claim 1, characterized in that: The first flywheel is rotationally arranged in a first flywheel sealing shell, the second flywheel is rotationally arranged in a second flywheel sealing shell, the first flywheel sealing shell and the second flywheel sealing shell are fixed in the inner wall of the vertical shaft, and the interiors of the first flywheel sealing shell and the second flywheel sealing shell are vacuumized.

5. A gravity power storage system with flywheel according to claim 1, characterized in that: The first rack pushing mechanism and the second rack pushing mechanism adopt electric push rods or screw mechanisms.

6. A gravity power storage system with flywheel according to claim 1, characterized in that: The upper end of the shaft is provided with a first guide rail and a second guide rail, the upper end of the first rack is slidingly arranged in the first guide rail and can be lifted in the first guide rail along the vertical direction, the upper end of the second rack is slidingly arranged in the second guide rail and can be lifted in the second guide rail along the setting direction, and the first guide rail and the second guide rail are fixed on the upper end of the shaft by guide rail supports respectively.

7. A gravity power storage system with flywheel according to claim 6, characterized in that: The horizontal thickness of the first guide rail and the second guide rail matches the thickness of the first rack and the second rack, the horizontal length of the first guide rail and the second guide rail matches the length of the first rack sliding groove and the second rack sliding groove, the first rack can slide along the horizontal length direction of the first guide rail, and the second rack can slide along the horizontal length direction of the second guide rail.

8. A gravity power storage system with flywheel according to claim 1, characterized in that: The rack lifting driving mechanism comprises a steel wire rope, a winch, a gear box and a gravity energy storage motor / generator, one end of the steel wire rope is connected with the upper end of the first rack and the second rack, the other end of the steel wire rope is arranged on the winch, one end of the winch is connected with the output end of the gear box, and the input end of the gear box is connected with the gravity energy storage motor / generator.

9. A control method of a flywheel-equipped gravitational energy storage system as claimed in any one of claims 1-8, characterized in that The method comprises the following steps: Setting flywheel upper and lower speed ω max and ω min , flywheel limit coefficient r, gravity block rated speed v rate , gravity block adjustment speed v target ; measure and record the flywheel real-time speed ω0 and gravity block real-time moving speed v0; There are three energy storage modes when the gravity energy storage system enters the energy storage state: Energy storage mode one: when v0=0, the gravity block is located at the lowest effective position, the first flywheel clutch and the second flywheel clutch are closed at the same time, and the first flywheel and the first flywheel speed increaser and the second flywheel and the second flywheel speed increaser are connected respectively, the rotational kinetic energy of the first flywheel is transmitted to the second rack through the first flywheel input gear, the rotational kinetic energy of the second flywheel is transmitted to the first rack through the second flywheel input gear, and the two racks are driven to lift the gravity block from the static state; Energy storage mode two: when 0 < v0< v rate , the rack lifting drive mechanism drives the rack to rise to lift the gravity block, and the real-time speed ω0 of the flywheel is determined: when rω max < ω0< rω max , the first flywheel and the second flywheel continue to provide kinetic energy for the gravity block until v0= v rate , the clutch of the first flywheel mechanism and the second flywheel mechanism is disconnected, and the two flywheel mechanisms are in a separated state with the gravity energy storage device; when rω min < ω0< rω max , the clutch of the first flywheel mechanism and the second flywheel mechanism is disconnected at the same time, and the two flywheel mechanisms are in a separated state with the gravity energy storage device; Energy storage mode three: when v0=v rate , and the gravity block rises smoothly, it needs to accelerate to v target , the clutches of the first and second flywheel mechanisms change from the disconnected state to the closed state, and on the premise of ensuring ω min <ω0, continue to provide kinetic energy for the rack lifting drive mechanism until v0= v target , realize accelerated energy storage, and the two clutches are disconnected at the same time; the rack lifting drive mechanism lifts the gravity block to the highest position, realizing energy storage; then the rack pushing mechanism drives the two racks to move relatively along the flywheel axis direction, realizing the meshing of the first rack and the first flywheel input gear, and the meshing of the second rack and the second flywheel input gear, which is in the preparatory energy release state; There are two energy release modes when the gravity energy storage system enters the energy release state: Energy release mode one: when v0=0, the gravity block is located at the highest effective position, the gravity block is lowered to drive the rack lifting driving mechanism, and the rotational kinetic energy is converted into electrical energy through the gravity energy storage generator; Release mode two: when v0= v rate , the flywheel real-time speed ω0is judged, when ω min < ω0< ω max , the first flywheel mechanism and the second flywheel mechanism clutch are closed at the same time, the first flywheel input gear and the second flywheel input gear meshed with the first rack and the second rack start to rotate, and the rotating kinetic energy is transmitted to the first flywheel mechanism and the second flywheel mechanism, and the two flywheel mechanisms are in the energy storage state; when ω0= ω max , the flywheel charging is completed, and the two clutches of the flywheel mechanism are disconnected at the same time; the gravity block continues to drop to the lowest position to realize complete energy release, and then the rack pushing mechanism drives the two racks to move relatively along the flywheel axis direction, realizing the meshing of the first rack and the second flywheel input gear, and the meshing of the second rack and the first flywheel input gear, and being in the preparatory energy storage state.

Images