Gravity energy storage system

Abstract

The invention belongs to the technical field of gravity energy storage, and discloses a gravity energy storage system. The gravity energy storage system comprises a friction type elevator, a plurality of energy storage weights and at least two supporting assemblies, each supporting assembly comprises a supporting frame, a first fixed pulley and a second fixed pulley, and the first fixed pulley and the second fixed pulley are fixed to different heights of the supporting frame; the energy storage weight is located between two adjacent supporting assemblies, a first movable pulley is arranged at the top of the energy storage weight, and a second movable pulley is arranged at the bottom of the energy storage weight; a driving rope is wound around the friction type elevator and comprises a driving part and a winding part, the driving part is alternately wound around the first fixed pulley and the first movable pulley, the tail end of the driving part is connected to the winding part, and the winding part is alternately wound around the second fixed pulley and the second movable pulley. According to the gravity energy storage system, synchronous lifting or lowering of all energy storage weights can be achieved, the gravity energy storage system with the larger capacity can be conveniently formed, winding of a driving rope is facilitated, and the reliability and the implementability of the system are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of gravity energy storage, and in particular to a gravity energy storage system. Background Art

[0002] Gravity energy storage is a storage method that achieves energy storage and release through the conversion of gravitational potential energy and electrical energy. Specifically, it uses the height difference to cooperate with electromechanical equipment to achieve the lifting or lowering of the energy storage block to achieve energy storage and conversion. It is a highly sustainable innovative form of energy storage with the advantages of long discharge time, long cycle life, strong environmental adaptability and high safety. When there is surplus electricity generated by new energy, the surplus electricity is used to lift the energy storage block for "charging", and the gravitational potential energy is stored by raising the height of the energy storage weight. When the power consumption is at its peak, the system lowers the energy storage block and uses gravity to do work to "discharge", converting the gravitational potential energy into electrical energy for release. At present, new energy storage has become a core link in building a new power system with new energy as the main body as a rigid demand for coordinating interactive sources, grids, loads and storage and achieving a dynamic balance between power supply and demand.

[0003] Patent application number 202111551398.4 proposes a gravity energy storage system; the energy storage system also proposes the use of a pulley group consisting of multiple sets of fixed pulleys and movable pulleys to achieve the connection of multiple energy storage weights. There is no need to schedule the energy storage weights, and all energy storage weights can be discharged at the same time, which will be of great help in supporting the stability of the power grid frequency, and can greatly shorten the response time and provide fast frequency response support. However, the wire rope described in the patent is connected to a hoist at one end, and the wire rope is wound on the hoist drum. For a system with a larger energy storage capacity, the wire rope will be very long. If the wire rope is too long and is wound on the drum, there will be a problem of too large a thickness of the wire rope, and it will also be difficult to arrange the wire rope, resulting in poor reliability of the gravity energy storage system.

[0004] Therefore, there is an urgent need to provide a new type of gravity energy storage system to solve the above-mentioned technical problems in the prior art. Summary of the invention

[0005] The object of the present invention is to provide a gravity energy storage system that can achieve the synchronous lifting or lowering of all energy storage weights, facilitate the formation of a gravity energy storage system with a larger capacity, and facilitate the winding of a drive rope, thereby improving the reliability and feasibility of the system.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] The gravity energy storage system includes a friction hoist, a plurality of energy storage weights and at least two support assemblies, wherein the support assembly includes a support frame, a first fixed pulley and a second fixed pulley, and the first fixed pulley and the second fixed pulley are respectively fixed at different height positions of the support frame; the energy storage weights are arranged one by one between two adjacent support assemblies, the top of the energy storage weights is provided with a first movable pulley, and the bottom of the energy storage weights is provided with a second movable pulley; the friction hoist is wound with a drive rope, and the drive rope includes a drive part and a winding part, the drive part is drawn out from the friction hoist and alternately wound around the first fixed pulley and the first movable pulley, the end of the drive part is connected to the winding part, and the winding part is alternately wound around the second fixed pulley and the second movable pulley and introduced into the friction hoist.

[0008] Optionally, two of the above-mentioned friction lifts are provided, and the two friction lifts are relatively arranged at the two ends of at least two of the above-mentioned supporting components along the first direction, and the driving directions of the two friction lifts are opposite; the above-mentioned driving part is led out from one of the above-mentioned friction lifts and introduced into the other friction lift at the end.

[0009] Optionally, the gravity energy storage system further comprises two guide wheels, which are respectively arranged at the two ends of at least two supporting components along the first direction, and the driving part is led out from the first fixed pulley at the outermost end and wound around the corresponding guide wheel, and the outer edge diameter of the guide wheel is adjustable.

[0010] Optionally, the outer edge of the guide wheel is flush with the outer edge of the corresponding outermost first fixed pulley in the vertical direction.

[0011] Optionally, the outer edge of the guide wheel is flush with the outer edge of the corresponding friction hoist in the first direction.

[0012] Optionally, the guide wheel is provided with a guide lining, and the guide lining is clamped between the drive rope and the wheel body of the guide wheel.

[0013] Optionally, the friction hoist comprises a multi-rope friction hoist, and a plurality of the drive ropes are arranged side by side.

[0014] Optionally, the first fixed pulley and the second fixed pulley are each provided with a plurality of wire grooves, and the drive ropes are accommodated in the wire grooves one by one; or, the first fixed pulley and the second fixed pulley are each provided with a plurality of wire grooves side by side, and the drive ropes are wound around the first fixed pulley and the second fixed pulley one by one.

[0015] Optionally, the multi-rope friction hoist includes a hoist motor, an outer rotor friction wheel and a braking device, the hoist motor rotates synchronously with the outer rotor friction wheel, the drive rope is wound around the outer rotor friction wheel, and the braking device is used to brake the hoist motor.

[0016] Optionally, the multi-rope friction hoist further comprises a control system, wherein the control system is communicatively connected to the hoist motor and the guide wheel, and the control system is capable of adjusting the rotation speed of the hoist motor and the outer edge diameter of the guide wheel.

[0017] Beneficial effects:

[0018] The gravity energy storage system in this embodiment uses a friction hoist to lift the energy storage weight. Specifically, the friction hoist uses the driving part of the driving rope to tighten and drive the energy storage weight to rise. In this process, the driving part is wound around the two first fixed pulleys and the first movable pulley between the two first fixed pulleys. The driving rope will be shortened when it is tightened by the friction hoist, so that the first movable pulley drives the energy storage weight to rise, and the energy storage weight drives the second movable pulley to rise. The second movable pulley is arranged between the two second fixed pulleys, so that the winding part of the driving rope is driven to stretch, compensating for the shortened length of the driving part, and realizing a driving rope to lift the energy storage weight without being wound and shortened. The gravity energy storage system solves the problem of driving rope winding, improves the reliability and feasibility of the system, and can set the number of support components and energy storage weights according to demand to achieve module expansion. It can also realize the synchronous lifting or lowering of all energy storage weights, without the need to mobilize some energy storage weights to achieve charging and discharging. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of a gravity energy storage system provided in a specific embodiment of the present invention;

[0020] Figure 2 is a schematic diagram of a first fixed pulley provided in a specific embodiment of the present invention;

[0021] Figure 3 is a schematic diagram of a second fixed pulley provided in a specific embodiment of the present invention;

[0022] Figure 4 is a schematic diagram of the outer diameter change process of the guide wheel provided in a specific embodiment of the present invention;

[0023] Figure 5 It is a schematic diagram of the gravity energy storage system in Example 3 provided in a specific embodiment of the present invention;.

[0024] In the figure:

[0025] 100, support assembly; 110, support frame; 120, first fixed pulley; 121, first wire groove; 130, second fixed pulley; 131, second wire groove; 132, fixed frame;

[0026] 200, energy storage weight; 210, first movable pulley; 220, second movable pulley; 230, connecting rope;

[0027] 300, friction hoist; 310, driving rope; 311, driving unit; 312, winding unit; 320, guide wheel; 321, hydraulic cylinder; 322, supporting outer edge. DETAILED DESCRIPTION

[0028] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0029] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0031] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0032] The first direction described in this embodiment is Figure 1 The X direction shown in the figure is the horizontal direction, and the X direction and the vertical direction described in this embodiment are perpendicular to each other.

[0033] Please refer to Figure 1 The gravity energy storage system includes a friction hoist 300, a plurality of energy storage weights 200 and at least two support assemblies 100, wherein the support assembly 100 includes a support frame 110, a first fixed pulley 120 and a second fixed pulley 130, wherein the first fixed pulley 120 and the second fixed pulley 130 are respectively fixed at different heights of the support frame 110; the energy storage weights 200 are arranged one by one between two adjacent support assemblies 100, and a first movable pulley 210 is arranged on the top of the energy storage weights 200; A second movable pulley 220 is provided at the bottom of 200; a driving rope 310 is wound around the friction hoist 300, and the driving rope 310 includes a driving portion 311 and a winding portion 312, the driving portion 311 is led out from the friction hoist 300 and alternately wound around the first fixed pulley 120 and the first movable pulley 210, the end of the driving portion 311 is connected to the winding portion 312, and the winding portion 312 is alternately wound around the second fixed pulley 130 and the second movable pulley 220 and introduced into the friction hoist 300.

[0034] The gravity energy storage system in this embodiment uses a friction hoist 300 to lift the energy storage weight 200. Specifically, the friction hoist 300 uses the driving part 311 of the driving rope 310 to tighten and drive the energy storage weight 200 to rise. In this process, the driving part 311 is wound around the two first fixed pulleys 120 and the first movable pulley 210 between the two first fixed pulleys 120. The driving rope 310 is shortened when it is tightened by the friction hoist 300, so that the first movable pulley 210 drives the energy storage weight 200 to rise, and the energy storage weight 200 drives the second movable pulley 220 to rise. The second movable pulley 220 is arranged between the two second fixed pulleys 130, so that the winding part 312 of the driving rope 310 is driven to stretch, compensating for the shortened length of the driving part 311, and realizing that the driving rope 310 can lift the energy storage weight 200 without being wound and shortened. The gravity energy storage system solves the problem of entanglement of the drive rope 310, improves the reliability and feasibility of the system, and can set the number of support assemblies 100 and energy storage weights 200 according to needs to achieve module expansion. It can also achieve synchronous lifting or lowering of all energy storage weights 200 without the need to mobilize some energy storage weights 200 to achieve charging and discharging.

[0035] It should be noted that the driving rope 310 can be a steel wire rope, a chain, a belt, etc., as long as it can be wound and frictionally contacted with the friction hoist 300. In this embodiment, a steel wire rope is selected, and the steel wire rope is a multi-strand steel wire rope. The steel wire rope is selected according to the weight of the energy storage weight 200 and the safety factor, and the stress of the steel wire rope under acceleration and deceleration braking is also considered.

[0036] The support frame 110 is the carrier of all energy storage weights 200 and the carrier of the entire system mass, providing a height difference for the energy storage weights 200 to achieve energy conversion. The support frame 110 can be in the form of a steel structure or a reinforced concrete structure.

[0037] Furthermore, the number of the above-mentioned support frames 110 is multiple, and they can be expanded along the first direction when arranged to form a row of support frames 110, and a gravity energy storage system can be provided with multiple rows of such support frames 110, thereby forming a complete gravity system support frame 110. In the specific design, it is necessary to consider the structural strength, rigidity and stability requirements of the external force on the support frame 110 to ensure that the safety requirements of the system for long-term operation are met. Preferably, the support frame 110 is in the form of reinforced concrete to ensure that the structural safety specifications and design standards can be met.

[0038] Furthermore, the energy storage weight 200 can be constructed with concrete, fly ash, scrapped wind turbine blades, waste cast iron, cast steel, etc., which can reduce the construction cost of the gravity energy storage project while reusing solid waste, bringing environmental and economic benefits. The energy storage weight 200 is connected to the first movable pulley 210 and the second movable pulley 220 by a connecting rope 230, which will not be described in detail here.

[0039] The connecting rope 230 is a connecting device connecting the movable pulley and the energy storage weight 200. There is a connecting rope 230 at the top and bottom of each energy storage weight 200, which is connected to the first movable pulley 210 above the energy storage weight 200 and the second movable pulley 220 below, so as to ensure that the energy storage weight 200 can rise and fall in the closed transmission system. It should be noted that the first movable pulley 210, the second movable pulley 220 and the energy storage weight 200 can be integrally formed, which reduces the use of the connecting rope 230, simplifies the system structure, and improves the reliability of the system operation.

[0040] It should be noted that the top of the same support frame 110 can be provided with multiple first fixed pulleys 120, and the bottom can be provided with multiple second fixed pulleys 130, thereby forming a first pulley group and a second pulley group, and correspondingly, the energy storage weight 200 is also provided with multiple, and the first movable pulley 210 and the second movable pulley 220 also form a movable pulley group respectively, so as to realize the expansion of the gravity energy storage system in another horizontal direction perpendicular to the first direction, and the friction hoist 300 at this time is selected as a multi-rope friction hoist. The setting of the movable pulley group can realize the average distribution of the load on the driving rope 310 and reduce the force on the driving rope 310.

[0041] Optionally, two friction hoists 300 are provided, and the two friction hoists 300 are relatively arranged at the two ends of at least two support assemblies 100 along the first direction, and the driving directions of the two friction hoists 300 are opposite; the driving part 311 is led out from one of the friction hoists 300 and the end is introduced into the other friction hoist 300. It should be noted that when one friction hoist 300 is provided, a fixed pulley (such as an idler pulley) can be provided at the position where the friction hoist 300 is placed on the other side to realize the winding of the driving rope 310. Two friction hoists 300 are provided here, and their driving directions are opposite, so that the driving rope 310 can be tightened and shortened at the same time, thereby improving the lifting efficiency of the energy storage weight 200.

[0042] Furthermore, the gravity energy storage system further comprises two guide wheels 320, which are arranged one by one at both ends of at least two support assemblies 100 along the first direction, and the driving part 311 is led out from the first fixed pulley 120 at the outermost end and wound around the corresponding guide wheel 320, and the outer diameter of the guide wheel 320 is adjustable. Figure 4 As shown, specifically, the guide wheel 320 includes a hydraulic cylinder 321 and a supporting outer edge 322 arranged at the output end of the hydraulic cylinder 321. The output end of the hydraulic cylinder 321 can drive the supporting outer edge 322 to move radially outward, thereby increasing the outer edge of the guide wheel 320. The setting of the guide wheel 320 can achieve the function of changing direction and guiding, and can also change the contact angle between the driving rope 310 and the friction hoist 300, thereby changing the friction provided by the friction hoist 300 and improving the lifting efficiency.

[0043] Specifically, there are six hydraulic cylinders 321 and six supporting outer edges 322 corresponding to each other, which will not be described in detail here.

[0044] As a preferred embodiment, the outer edge of the guide wheel 320 is flush with the outer edge of the corresponding friction hoist 300 in the first direction. At this time, the portion of the drive rope 310 connected to the friction hoist 300 remains horizontal and tangent to the top of the friction hoist 300, which can increase the friction between the drive rope 310 and the friction hoist 300.

[0045] It should be noted that if the outer diameter of the guide wheel 320 is further increased, the contact angle between the drive rope 310 and the friction hoist 300 can be greater than 180°, which can further increase the friction between the drive rope 310 and the friction hoist 300 and achieve control of the movement speed of the energy storage weight 200.

[0046] Please continue to refer to Figure 1 The outer edge of the guide wheel 320 is flush with the outer edge of the corresponding outermost first fixed pulley 120 in the vertical direction. The driving rope 310 connected to the guide wheel 320 is tangent to the guide wheel 320 in the vertical direction, so that the pressure of the driving rope 310 transmitted to the first fixed pulley 120 on the outermost support frame 110 is vertically downward, and no overturning force that can cause the support assembly 100 to tilt in the first direction is generated, thereby improving the stability of the gravity energy storage system.

[0047] Specifically, when the diameter of the guide wheel 320 is the smallest, the guide wheel 320 is tangent to the outermost driving rope 310 in the vertical direction, so that the pressure of the driving rope 310 transmitted to the first fixed pulley 120 on the outermost support frame 110 is vertically downward, and will not generate a force that can cause the first fixed pulley 120 and the support assembly 100 to overturn in the left and right directions, thereby improving the stability of the system. Subsequently, the guide wheel 320 is tangent to the driving rope 310 passing around it in the horizontal direction, thereby achieving the function of changing direction and guiding; the purpose of setting the guide wheel 320 is to provide a larger contact angle between the driving rope 310 and the multi-rope friction hoist, thereby improving its friction. Furthermore, when the diameter of the guide wheel 320 becomes larger, the wrapping angle between the contact point and the separation point between the drive rope 310 and the drum of the multi-rope friction hoist will become larger and exceed 180°, which will increase the friction force between the drive rope 310 and the drum of the multi-rope friction hoist, thereby enabling the movement speed of the energy storage weight 200 to be controlled.

[0048] In this embodiment, the guide wheel 320 is provided with a guide lining, which is sandwiched between the drive rope 310 and the wheel body of the guide wheel 320. The guide lining is used to prevent the drive rope 310 from directly contacting the metal wheel body of the guide wheel 320, thereby reducing the wear between the wire rope and the guide wheel 320. The material of the guide lining can be polyurethane, nylon, ultra-high molecular polyethylene, rubber, rubber-plastic composite material, etc.

[0049] Optionally, the friction hoist 300 comprises a multi-rope friction hoist, and the drive ropes 310 are arranged in parallel. The arrangement of multiple drive ropes 310 can simultaneously lift the energy storage weight 200, which can increase the weight of a single energy storage weight 200 and improve the reliability of the system. The drive ropes 310 are preferably 4, which are wound around the corresponding movable pulley and fixed pulley to form an overall closed transmission chain system, so that they rotate under the drive of friction, thereby driving the energy storage weight 200 to rise or fall.

[0050] like Figure 2 and Figure 3 As shown, the first fixed pulley 120 and the second fixed pulley 130 are both provided with a plurality of wire grooves, and the driving ropes 310 are accommodated in the wire grooves one by one; or, the first fixed pulley 120 and the second fixed pulley 130 are both provided with a plurality of wire grooves side by side, and the driving ropes 310 are wound around the first fixed pulley 120 and the second fixed pulley 130 one by one. Specifically, the first fixed pulley 120 is provided with a first wire groove 121, and the second fixed pulley 130 is provided with a second wire groove 131. The number of wire grooves is limited to 2-10, which is convenient for winding multiple steel wire ropes, and the preferred number of wire grooves is 4.

[0051] The second fixed pulley 130 is fixed to the bottom of the support frame 110 through a fixed frame 132. The fixed frame 132 is a closed frame structure, which can realize a reliable connection between the second fixed pulley 130 and the support frame 110. Specifically, the fixed frame 132 is fixed to the bottom of the support frame 110 by connecting bolts, which will not be repeated here.

[0052] Furthermore, the guide wheel 320, the first movable pulley 210 and the second movable pulley 220 are also provided with the same number of wire grooves for accommodating the drive rope 310, which will not be described in detail here.

[0053] Optionally, the multi-rope friction hoist includes a hoist motor, an outer rotor friction wheel and a braking device, the hoist motor rotates synchronously with the outer rotor friction wheel, the drive rope 310 is wound around the outer rotor friction wheel, and the braking device is used to brake the hoist motor. The hoist motor is a permanent magnet direct drive outer rotor synchronous motor / generator with a large moment of inertia. It is designed according to the weight of the energy storage weight 200 and the force of the rope, the rotor radius size and the discharge time, so as to ensure that the energy storage weight 200 of the system is in a state of force balance when the load is stable, thereby maintaining the uniform descent of the energy storage weight 200, achieving stable power output, and ensuring that the power generation frequency is consistent with the grid frequency. The outer rotor friction wheel is arranged on the outer rotor housing of the hoist motor, which is composed of a friction lining, and is used to provide friction to the drive rope 310 so as to drive the drive rope 310 to move through the friction force, so as to realize the charging, lifting and descending discharge process of the energy storage weight 200. The brake device is a disc brake, which is a safety device for controlling the start, speed regulation, stop and safe stop of the hoist motor of the multi-rope friction hoist in an emergency.

[0054] Optionally, the multi-rope friction hoist further includes a control system, which is communicatively connected to the hoist motor and the guide wheel 320, and can adjust the rotation speed of the hoist motor and the outer diameter of the guide wheel 320. The control system is specifically a PLC control system, which controls the extension and retraction of the hydraulic cylinder 321 of the guide wheel 320 and the operation of the hoist motor, and also controls the switching of the hoist motor between the motor mode and the generator mode.

[0055] Specifically, when the energy storage weight 200 is lifted, the hoist motor is in the motor mode, the PLC control system sends a start signal to the frequency converter, the frequency converter gradually increases the output frequency according to the preset start curve, so that the motor starts smoothly, and the energy storage weight 200 is lifted. After the energy storage weight 200 is lifted in place, the PLC control system sends a signal that the brake device starts working, the motor stops working and instantly locks the outer rotor friction wheel of the hoist motor, and the charging of the gravity energy storage system is completed. When the energy storage weight 200 is lowered, the hoist motor is in the generator mode. At this time, the PLC control system first releases the brake device, relies on the gravity of the energy storage weight 200 itself to generate a pulling force on the drive rope 310, and then according to the torque generated by the friction between the drive rope 310 and the outer rotor friction wheel, the hoist motor is rotated, and gradually accelerates to reach the synchronous speed, so as to realize the power generation of the gravity energy storage system.

[0056] Furthermore, during the startup process, the PLC control system can adjust the radial extension and retraction of the guide wheel 320 by controlling the hydraulic cylinder 321 so that the wrapping angle between the drive rope 310 and the friction wheel of the motor outer rotor is larger, thereby providing a larger friction force.

[0057] Specifically, when starting, the PLC control system issues a command to increase the oil pressure of the hydraulic cylinder 321, thereby causing the guide wheel 320 to extend outward along the outer edge 322 of the support. After the outer diameter is extended to a certain value, a constant pressure is maintained, ensuring that the guide wheel 320 has greater rigidity after the diameter increases, and also increases the wrap angle between the drive rope 310 and the outer rotor friction wheel, thereby having a larger torque, so that the hoist motor reaches the synchronous speed as soon as possible. When the hoist motor reaches the synchronous speed, it starts to connect to the grid for power generation. During the grid connection process, the diameter of the guide wheel 320 and the speed of the generator can be fine-tuned to stabilize the output voltage and frequency of the generator, ensuring that the generator provides inertia support for the power grid and completes the discharge of the gravity energy storage system.

[0058] Below, the attached Figure 1 The specific implementation of the gravity energy storage system is described in detail with specific examples.

[0059] Example 1

[0060] Taking the design of a 100MWh gravity energy storage system as an example, there are 101 support assemblies 100 in a row, and the spacing is designed to be 1.2m. The number of the first fixed pulley 120 and the second fixed pulley 130 are both 101. Then, the number of 30t energy storage weights 200 that can be set inside the support assemblies 100 is 100, the number of the first movable pulley 210 and the second movable pulley 220 are both 100, the connecting rope 230 has 200 sections, the guide wheels 320 are 2, the multi-rope friction hoists are set to 2, and the drive is a whole rope, which passes through the multi-rope friction hoist, the guide wheel 320, the first fixed pulley 120, the second fixed pulley 130, the first movable pulley 210, the second movable pulley 220, etc. in sequence to form a closed and complete transmission chain, which also constitutes a single-row gravity energy storage system, which can be called a gravity energy storage module. 91 rows of the gravity energy storage modules are designed, and the center distance between each group is also 1.2m. The length of the system along the first direction is 120m, the system width is 109.2m, and the designed system height is 148m, which can form a gravity energy storage system with a capacity of 100MWh.

[0061] The energy storage weight 200 can be made of concrete, in the shape of a cuboid, with a square bottom side length of 1m and a height of 12m. A single weight can reach 30t, and a system with a capacity of 100MWh has a total of 9,100 energy storage weights 200. When all the energy storage weights 200 are lifted to the top at 148m, the stored energy calculated according to their center of gravity can reach 101.07MWh.

[0062] Specifically, the relevant calculations are as follows:

[0063] The design number N of energy storage weights 200 in a single row of gravity energy storage systems composed of 101 support frames 110 is 100;

[0064] System design line number N R =91; according to the length direction spacing L = 1.2m, the system length L 总 =N×L=100×1.2=120m;

[0065] According to the width spacing W = 1.2m, the system width is W 总 =N R ×W=91×1.2=109.2m; system height H 总 =H k =148m; concrete energy storage weight 200 bottom side length a z =1m; concrete energy storage weight 200 length L z =12m; concrete density ρ z =2500kg / m 3 .

[0066] The weight of the concrete energy storage weight 200 is calculated as:

[0067] W _ z=ρ z ×a z ×a z ×L z =2500×1×1×12=30000kg

[0068] Considering the gravitational acceleration g and the center of gravity of the energy storage weight 200, the energy stored in a single energy storage weight 200 is:

[0069] E s =mg(H k -H)=30000×9.8×(148-12)=39984000J

[0070] Convert joules to kilowatt-hours according to the conversion between joules and kilowatt-hours:

[0071] E s =39984000 / 3600000=11.107kWh

[0072] That is, the maximum energy that can be stored in an energy storage weight 200 is 11.107 kWh.

[0073] Since the single-row gravity energy storage system has a total of 100 energy storage weights 200 storing energy, the energy stored in the single-row gravity energy storage system is:

[0074] E sm=N×Es=100×11.107=1110.7kWh

[0076] Then, the storage capacity of the gravity energy storage module in row 91 of this example 1 is:

[0077] E_cal=NR×Esm=91×1110.67=101070.97kWh=101.07MWh

[0078] That is, Example 1 can meet the 100MWh system capacity requirement.

[0079] In addition, based on the energy stored in each row of 100 energy storage weights 200 of 1110.7 kWh and the discharge time of 2 h, combined with the calculation formula of energy, power and time E=P×t (E is energy, unit is kWh; P is power, unit is kW; t is time, unit is h), the total power of the hoist motor is calculated to be 555.35 kW. Since there is a hoist motor at each end, the operating power required for a single hoist motor is 277.675 kW.

[0080] Example 2

[0081] The difference from the above example 1 is that one of the multi-rope friction hoists is replaced with an idler wheel, which only provides guidance and support, that is, only one multi-rope friction hoist is provided. At this time, according to the energy storage time of 2h, the required operating power of the hoist motor is 555.35kW.

[0082] Example 3

[0083] like Figure 5 As shown, the gravity energy storage system in this example three is not set on a plane, but on a non-horizontal plane. The height of the energy storage weight 200 and the support assembly 100, the height of the support frame 110, and the height of the second fixed pulley 130 can be adjusted according to the relative difference in altitude or height direction of the non-horizontal plane, so that the height difference between the center of gravity of two adjacent energy storage weights 200 is consistent with the height difference caused by the non-horizontal height of the ground, and the weight of the energy storage weights 200 is ensured to be consistent. Further, in order to ensure that the weight of the energy storage weights 200 is consistent, the density of the two adjacent energy storage weights 200 is different.

[0084] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. Gravity energy storage system, characterized in that: include: At least two support assemblies (100), the support assemblies (100) comprising a support frame (110), a first fixed pulley (120) and a second fixed pulley (130), the first fixed pulley (120) and the second fixed pulley (130) being respectively fixed at different height positions of the support frame (110); A plurality of energy storage weights (200), wherein the energy storage weights (200) are arranged one by one between two adjacent support assemblies (100), a first movable pulley (210) is arranged on the top of the energy storage weight (200), and a second movable pulley (220) is arranged on the bottom of the energy storage weight (200); A friction hoist (300), wherein the friction hoist (300) is wound with a drive rope (310), wherein the drive rope (310) comprises a drive portion (311) and a winding portion (312), wherein the drive portion (311) is led out from the friction hoist (300) and alternately wound around the first fixed pulley (120) and the first movable pulley (210), wherein the end of the drive portion (311) is connected to the winding portion (312), and the winding portion (312) is alternately wound around the second fixed pulley (130) and the second movable pulley (220) and introduced into the friction hoist (300).

2. The gravity energy storage system according to claim 1, characterized in that: Two friction lifters (300) are provided, and the two friction lifters (300) are relatively arranged at the two ends of at least two supporting assemblies (100) along the first direction, and the driving directions of the two friction lifters (300) are opposite; the driving part (311) is led out from one of the friction lifters (300) and is introduced into the other friction lifter (300) at the end.

3. The gravity energy storage system according to claim 2, characterized in that: The gravity energy storage system further comprises two guide wheels (320), the two guide wheels (320) being arranged one by one at two ends of at least two support assemblies (100) along a first direction, the driving part (311) being led out from the first fixed pulley (120) at the outermost end and being arranged around the corresponding guide wheel (320), and the outer edge diameter of the guide wheel (320) being adjustable.

4. The gravity energy storage system according to claim 3, characterized in that: The outer edge of the guide wheel (320) is flush with the outer edge of the corresponding outermost first fixed pulley (120) in the vertical direction.

5. The gravity energy storage system according to claim 3, characterized in that: The outer edge of the guide wheel (320) is flush with the outer edge of the corresponding friction lifter (300) in the first direction.

6. The gravity energy storage system according to claim 3, characterized in that: The guide wheel (320) is provided with a guide lining, and the guide lining is sandwiched between the drive rope (310) and the wheel body of the guide wheel (320).

7. The gravity energy storage system according to claim 3, characterized in that: The friction hoist (300) comprises a multi-rope friction hoist, and a plurality of drive ropes (310) are arranged side by side.

8. The gravity energy storage system according to claim 7, characterized in that: The first fixed pulley (120) and the second fixed pulley (130) are both provided with a plurality of wire grooves, and the driving ropes (310) are accommodated in the wire grooves one by one; or, the first fixed pulley (120) and the second fixed pulley (130) are both provided with a plurality of wire grooves side by side, and the driving ropes (310) are sequentially wound around the first fixed pulley (120) and the second fixed pulley (130) one by one.

9. The gravity energy storage system according to claim 7, characterized in that: The multi-rope friction hoist comprises a hoist motor, an outer rotor friction wheel and a braking device, the hoist motor rotates synchronously with the outer rotor friction wheel, the drive rope (310) is wound around the outer rotor friction wheel, and the braking device is used to brake the hoist motor.

10. The gravity energy storage system according to claim 9, characterized in that: The multi-rope friction hoist also includes a control system, which is communicatively connected to the hoist motor and the guide wheel (320), and the control system is capable of adjusting the rotation speed of the hoist motor and the outer edge diameter of the guide wheel (320).

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