A gravity energy storage system based on a minimum value model and a design method thereof

Abstract

A gravity energy storage system based on a minimum model and its design method are disclosed. The gravity energy storage system includes a support frame, a car, a power drive unit including a stator, a mover, upper and lower storage yards, and weights as the energy storage medium. The design method includes: S1, setting the discharge reference speed, stator unit length cost, mover reference length, and single weight reference mass according to the target energy storage power; S2, setting the speed multiplier and mover lengthening multiplier; S3, setting the discharge stroke height y, and calculating the total number of weights based on the target energy storage duration t; S4, establishing a basic discharge cost function within the discharge stroke; S4, solving for the minimum value Qmin of the basic discharge cost function and the optimal discharge stroke H0 and weight number n0. Applying this method to finely segment long-stroke linear motors into elongated strips can significantly reduce drive costs by more than 85%, maximizing the economic and modular advantages of the "power reuse" direct-drive cycle architecture.

Description

Technical Field

[0001] This invention belongs to the field of gravity energy storage, specifically relating to a gravity energy storage system based on a minimum value model and its design method. Background Technology

[0002] Data from the National Energy Administration shows that by 2025, the total installed power generation capacity in China will reach 3.79 billion kilowatts, with new energy accounting for as much as 46.4% (of which, photovoltaic and wind power will account for 1.16 billion kilowatts and 600 million kilowatts respectively, with a total installed capacity exceeding 1.76 billion kilowatts). The power system's regulation demand will shift from "intraday" to "cross-day / cross-week", and long-term energy storage of ≥8 hours has become a necessity. The fundamental contradiction in the current energy storage market is that while the installed capacity of new energy storage has reached 73.76 GW, over 95% of it is for short-term configurations of 2-4 hours (average duration of only 2.3 hours). Among these, lithium batteries account for as much as 96.4%, while other new energy storage methods account for only 3.6%, leading to fierce competition due to homogeneity. Lithium batteries are "continuously consumable materials" and are not suitable for long-term use; the longer the storage time, the higher the cost per kilowatt-hour. Pumped storage is also insufficient and lacks site selection, resulting in long construction cycles and an inability to flexibly respond to distributed scenarios. Air-compressed storage and traditional heavy storage rely on specific geographical and geological (environmental) conditions, leading to long construction and return cycles.

[0003] Gravity energy storage is a mechanical energy storage technology that uses electricity to lift a heavy object to a high position, creating gravitational potential energy to complete the energy storage process. The gravitational potential energy is then converted into kinetic energy, and finally into electrical energy, as the object falls. By precisely managing the movement of the heavy object and the effects of gravity, efficient energy storage and release can be achieved. Various solutions exist, including lifting-and-releasing gravity energy storage. Installed capacity has reached hundreds of megawatts. However, traditional gravity energy storage technology is constrained by the "heavy single-point lifting + mechanical transmission" architecture, resulting in complex systems, low cycle efficiency, limited lifting height and speed due to ropes, high costs and difficulty in expansion, poor asset attributes, and the high risk of breakage in heavy single-point transmission systems, as well as ongoing maintenance issues.

[0004] Therefore, applying linear motors to gravity energy storage is of great significance, enabling the simultaneous and efficient lifting (lowering) of multiple heavy objects within a single channel. Linear motor-driven multi-car direct-drive gravity energy storage addresses the lifespan and safety issues of lithium batteries through physical means, and solves the limitations of traditional gravity energy storage in terms of lifting height, speed, and slow response through direct-drive technology. It is the only gravity energy storage technology capable of efficiently participating in rapid frequency regulation of the power system. It features a modular design, easy expansion, zero attenuation, zero resource constraints, all-weather operation, and adaptability to various scenarios and environments such as open fields, mountains, and abandoned mines. It is a standardized industrial product that can be flexibly and rapidly deployed at the city, park, and user levels. Intrinsically safe: modular direct drive with no heavy single-point transmission components; heavy objects are physically constrained by the track (and multiple protections); highly automated, allowing for unattended operation, and easier large-scale application.

[0005] Pumped storage power stations, as is commonly known, are often built near mountains, pumping water from lower elevations into reservoirs on the mountainside. The main reason for this is that the water capacity and pressure are too great. The reservoirs are built on high-altitude mountains to utilize the natural mountain structure to support (bear) this enormous pressure, thereby reducing construction costs. For the same reason, as in the solutions CN120140162A and CN119298408A, the weight of the bulk (energy block) in a single gravity energy storage system reaches thousands or even tens of thousands of tons. Currently, it mainly faces two major bottleneck problems: high storage yard costs and high drive costs. On the one hand, the excessive weight of the bulk as the energy medium causes the storage yard to be subjected to enormous pressure and bending (overturning) moments. Generally, such a large-scale concrete load-bearing building is constructed to absorb and withstand such a large force, which causes the cost of the main supporting structure and installation foundation to rise sharply, and the construction cycle to be long. Often, the infrastructure cost accounts for more than 50% of the total investment. On the other hand, the weight of the bulk and the total bulk are too large. The cost of using conventional linear motor drive schemes is too high, which may account for more than 40% of the total investment, resulting in high overall construction costs and cost per kilowatt-hour, and even making it uneconomical. Summary of the Invention

[0007] To address the aforementioned pain points, this invention provides a gravity energy storage system based on a minimum value model and its design method by optimizing the structure of the gravity energy storage system.

[0008] The objective of this invention is achieved in the following manner: a gravity energy storage system based on a minimum value model and its design method. The gravity energy storage system includes at least: The support frame serves as the supporting skeleton for the entire system. The car body is raised and lowered in coordination with the support frame. The power drive unit includes a stator section, which is fixed to a support frame and extends along the travel direction; it also includes a mover section, which is fixed to the car and cooperates with the stator section to form a power drive system. Upper storage yard, lower storage yard, and heavy blocks used as energy storage medium; The design method includes the following steps: S1. Based on the target energy storage power P of the gravity energy storage system, set the reference speed v0 during discharge, the reference mass G0 of a single weight, the reference length L0 of the mover, and the reference cost C per unit length of the stator. d Benchmark value C for unit length of moving part L ; S2, Set the speed multiplier k and the mover lengthening multiplier k L This results in the running speed v = k·v0 and the mover length L = kL • L0, the mass of a single heavy block G = G0 / k; S3. Set the discharge stroke y, calculate the single-stroke discharge time t0=y / (k·v0), and calculate the total number of weights n=k·v0 t / y based on the target energy storage time t of the gravity energy storage system; S4. Based on S1, S2, and S3, establish a basic discharge cost function Q, wherein the basic discharge cost includes at least the total weight cost and the basic cost of the discharge stroke segment. S5. Solve for the minimum value of the basic discharge cost function Q to obtain the optimal discharge stroke y0 and the optimal number of heavy blocks n0. S6. Based on the optimal stroke y0 and the optimal number of weights n0, apply the adjustment multiples k and k L The parameters of the system's operating speed v, mover length L, and single-load weight G are optimized and adjusted so that the overall cost of the drive section or the entire energy storage system tends to be the lowest or optimal while meeting the requirements of the target energy storage power P and the target energy storage duration t.

[0009] Furthermore, the basic discharge cost function Q is defined by the following expression: Q = y C d / (k L k)+V0t C G G0 / y Among them, C G Cost per unit weight of the heavy block.

[0010] Furthermore, the minimum point is determined by solving for the derivative of the basic discharge cost function Q and setting the derivative to zero. The second derivative is also greater than zero to verify that it is a minimum. The minimum value of Q is Q_min. min Defined by the following expression: Q min = 2[V0t C G G0C d / (k L k)] 1 / 2 .

[0011] Furthermore, k L While doubling the length of the mover, at k L The stator width is reduced by the same factor to maintain a constant lifting force.

[0012] Furthermore, while increasing the speed by a factor of k, the mass of a single heavy block is reduced by the same factor of k, G = G0 / k, to maintain constant power.

[0013] Furthermore, based on the value of k and k L The value determines the optimal value of the discharge stroke: y0=(kV0t k L C G G0 / C d ) 1 / 2 ; Based on the value of k and k L The value determines the optimal number of duplicate blocks: n0=[kV0t C d / (k L C G G0)] 1 / 2 .

[0014] Furthermore, when the total cost Q of the weight blocks... G The cost Q equals at least the cost of the stator or power drive system during the discharge stroke. d At that time, the basic discharge cost has a minimum value Q. min And Q min =2Q G =2Q d .

[0015] Furthermore, the gravity energy storage system is a cyclic operation system consisting of at least one ascending channel and at least one descending channel. The stockpile adopts a single-layer structure or is vertically divided into at least two sub-stockpile layers. The car has a single-layer loading space or is vertically divided into at least two loading spaces. Each single-layer or layer of loading space is used to carry a heavy block and docks with the corresponding layer of stockpile for loading or unloading the heavy block. The top and bottom of the drive frame are respectively provided with upper and lower turntables or transfer mechanisms that allow the car to switch positions between the ascending channel and the descending channel. The car, through the upper and lower turntables or transfer mechanisms, cooperates with the upper and lower stockpile layers to realize the cyclic descent or ascent of the heavy block.

[0016] Furthermore, the gravity energy storage system is a continuous circulation system consisting of at least one ascending channel and at least one descending channel, including at least two cars, upper and lower storage yards, a closed track consisting of straight and curved sections, a stator section consisting of straight and curved section unit stators arranged along the closed track, and a mover section consisting of one unit mover or multiple unit movers flexibly connected by hinges in cooperation with the stator section. The one or more unit movers are fixedly or flexibly connected to one or more cars and cooperate with the upper and lower storage yards to realize the cyclic descent or elevation of the heavy blocks.

[0017] Furthermore, the power drive device of the gravity energy storage system is at least one of the following: a linear motor, a rotary motor gear and rack transmission mechanism, a wire rope lifting device, a traction transmission mechanism, or a chain transmission mechanism.

[0018] Compared to existing technologies, this invention utilizes a minimum value model and k, kL The two cost adjustment factors (adjustment levers) can be easily unified, compared, and used to design the energy storage system (solution) with the best cost performance. Attached Figure Description

[0019] Figure 1 This is one of the schematic diagrams of a gravity energy storage system; Figure 2 This is the second schematic diagram of a gravity energy storage system. Figure 3 This is a schematic diagram of the stator slender strip segmentation principle when the speed is increased by k times, as shown in the figure (k=50). Figure 4 It is a mover lengthening k L Schematic diagram of a multiplied stator, shown in the figure (k) L =3); Figure 5 This is a schematic diagram of a gravity energy storage system (four channels); Figure 6 This is a front view of a gravity energy storage system (four channels); Figure 7 This is an exploded view of a gravity energy storage system (four channels); Figure 8 This is a top view of the turntable structure; Figure 9 yes Figure 8 AA section view; Figure 10 This is a top view of a gravity energy storage system (four channels); Figure 11 yes Figure 10 Enlarged view of the dotted line area; Figure 12 This is a schematic diagram of a gravity energy storage system (dual-channel). Figure 13 This is a schematic diagram illustrating the evolution (comparison) from single-layer to multi-layer storage yards; Figure 14 This is a schematic diagram comparing the principles of multi-level storage yards, multi-level car cabins, and single-level car cabins. Figure 15 A schematic diagram illustrating the principle of reducing the speed by a factor of k, increasing the length of the mover by a factor of k, and reducing the total area of ​​the stacking yard (for the same single heavy block) by a factor of k while increasing the number of layers by a factor of k (shown as k=2). Figure 16 This is a schematic diagram of a well-type gravity energy storage system. Figure 17 This is a schematic diagram of the structure of a well-type gravity energy storage system after the well body has been removed. Figure 18 This is a cross-sectional view of a well-type gravity energy storage system; Figure 19 This is a top view of a well-type gravity energy storage system; Figure 20 This is a schematic diagram of a well-type gravity energy storage system with a rotating track that slides or rolls with the support column.

[0020] The components include: base 1, linear motor stator 2, linear motor mover 3, arc-shaped linear motor stator 4, arc-shaped linear motor mover 5, arc-shaped guide rail 6, arc-shaped guide rail slider 7, car 8, second conveying unit 9, turntable rotary motor 10, electromagnet 11, transfer and conveying unit 12, sensor 13, weight 14, third conveying unit 15, brake 16, rotatable stator 17, fixed section guide brake rail 18, horizontal fixed section guide brake rail 180, rotatable track 181, positioning wheel group 19, main positioning wheel 191, side positioning wheel 192, rotatable support column 195, rotatable connecting ring beam 196, non-rotatable stator 20, turntable structure 21, storage yard 22, annular rotating support 23, temporary storage yard 24, long-term storage yard 25, and support column 26. Detailed Implementation

[0021] The technical solutions of 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, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In this invention, unless otherwise explicitly specified and limited, the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "height," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0023] This invention proposes a multi-car (weight block) cyclic operation energy storage method: As shown in the basic principle diagram, the upper and lower storage yards are used to store multiple weight blocks. Assume the left side is the lowering car (power generation operation) channel with a lowering speed V, and the right side is the return ascending channel for the empty car (electric operation). Cyclic operation is formed by upper and lower turntables. Generally, two cars, one ascending and one descending, can be set up. Since loading and unloading energy blocks and the turntable reversal require a certain amount of time (several seconds) (for continuous track cyclic operation without turntables, even with special structural design to ensure uninterrupted loading and unloading of energy blocks, the continuous curve-crossing topology makes it difficult to avoid even a one-second delay), in order to maintain continuous and uninterrupted lowering of the weight blocks on the left (continuous power generation), the ascending speed of the empty car may need to be greater than the lowering speed V to return to the highest position on the left before the lowered weight blocks land, thus causing unnecessary energy consumption (waste). A simple and economical method is to set up a third car as a "transfer assistant," which is "empty" near a high position (turntable) in advance. This allows the speed of the rising empty car (mover) to be equal to or even less than the lowering speed V. The three cars (taking turns as "transfer assistants") work together perfectly to continuously and uninterruptedly lower the heavy block through the upper and lower turntables (or continuous tracks) to complete the cyclic operation. Since the number and mass of the empty cars (movers) in the lowering and rising operations on both the left and right sides are the same, theoretically, the lowering empty car (mover) is generating electricity, while the other rising empty car (mover) is generating electricity. The two are "electrically" counterweights that balance and cancel each other out (in reality, due to transmission efficiency losses, the rising mover needs to supplement a small amount of the electrical energy generated by the lowering heavy block on the left, which will not be discussed here). Therefore, only the heavy block generates electrical energy during the entire cyclic operation, not the empty car (mover).

[0024] Figure 1-2 In the discussion, assuming the lowering (discharging) stroke y (meters) of the left-side car (mover), for ease of discussion, let's first assume a reference speed V0. At this speed, the cost per unit length of the stator is: C d, (Ten thousand yuan / meter), unit length cost of moving parts: C L (Ten thousand yuan / meter), single mover length L0 (meters); single car mover thrust F0 (tons); total number of weights n, mass of a single weight G0 (tons), G0=K G F0, where K G The thrust ratio coefficient can generally be taken as K. G ≈0.8-0.85; Cost of a single heavy block C G (Ten thousand yuan / ton); The speed is reset to V=kV0, where k is the factor by which the reference speed increases or decreases; the energy storage time (continuous discharge time) is t (hours). Based on this, we will specifically analyze, model and discuss the relationship and law between the discharge distance y and the total number of heavy blocks and the energy storage time t and the above-mentioned related parameters.

[0025] Since the power is constant, and the speed is adjusted to k times the original V0, the thrust of a single car mover is F0 / k (tons); at this speed V=kV0, the mass of a single weight is G=G0 / k=K. G F0 / k (tons); Cost per unit length of stator section: C d / k (ten thousand yuan / meter), unit length cost of moving parts: C L / k (ten thousand yuan / meter); Single-acting length L0 (meters); The unit length cost Cd of the stator section can, depending on the specific circumstances, include the stator section of the linear motor and its positioning mechanism, braking mechanism, turntable, as well as the mover section, car, and may even extend to the unit length cost of the electronic control system, track (channel), support column, etc.

[0026] One-way lowering (discharge) time: t0 = y / (kV0) (seconds); initial power generation P of n weights n During the continuous discharge period of energy storage duration t hours, the total power generation P of the discharge channel must be maintained at any given time. n The constant (or essentially constant).

[0027] Therefore, the total number of heavy blocks is: n = 3600t / t0 = 3600kV0t / y (pieces), Equation (1) As the focus of this discussion, only the lowering channel is considered. The upper channel has a lighter load, and the stator section can be arranged in the same or different ways as the lowering channel, depending on the specific charging and discharging duration, whether there are rotation requirements, etc. As for the number of channels: generally, the number of lowering channels is greater than or equal to the number of upper channels, with at least one upper channel and one lower channel. The following discussion and analysis will focus on the most basic and important cost of the stator section within the discharge stroke height of gravitational potential energy (mgh) power generation and the basic cost Q of all required weights, which has significant physical implications: Height of the lowering channel (stator section): H1 = L0 + y, Equation (2) In the formula, y is the discharge stroke (meters); Basic cost of discharge: Q = yC d / k (stator section) + (3600kV0t / y) C G G0 / k (heavy block), Equation (3) Find the extreme value of equation (3) and differentiate it with respect to Q: Q'=C d / k-3600V0tC GG0 / y 2 Let Q'=0, then we can solve for: y0=60(kV0t C G G0 / C d ) 1 / 2 n0=60[kV0t C d / (C G G0)] 1 / 2 Equation (4) The second derivative is Q''=7200V0tC G G0 / y 3 >0 Therefore, the critical point (equation (4)) is the minimum point. Substituting into y0=60(kV0tC) G G0 / C d ) 1 / 2 The minimum value is found to be: Q min = 120[V0t C d C G G0 / k] 1 / 2 Equation (5) Observe the minimum value of the basic cost of discharge in equation (5), and C d It is proportional to the square root, C d The unit length cost of the stator section (ten thousand yuan / meter) can be reduced by lowering C. d The starting point is cost reduction. Under the premise of constant speed and thrust, the cost per unit length of the stator section should be reduced to C. d / k L (Where: k) L To reduce the unit length cost of the stator by a factor of [percentage missing], the mover length needs to be increased accordingly by k. L Only L0 can maintain constant thrust (Note: the mover length remains constant, and simply relying on optimizing the stator to reduce the unit length cost C). d Optimization and cost reduction issues inherent to the invention are not within the scope of this invention. Furthermore, given C... d The unit length cost was originally given after multiple optimizations, so k L In essence, it's about increasing the length of the mover. Therefore, C in equations (3), (4), and (5) d Use C d / k L Replace, L0 with k L L0 replacement, C L Use C L / k L The alternatives can be further used to obtain more comprehensive and applicable equations (6), (7), and (8): Q = yC d / (k Lk)+(3600V0t / y)C G G0, Equation (6) y0=60(kV0t k L C G G0 / C d ) 1 / 2 ;n0=60[kV0t C d / (k L C G G0)] 1 / 2 Equation (7) Q min = 120[V0t C d C G G0 / (k L k)] 1 / 2 Equation (8) H1=k L L0+60(kV0t k L C G G0 / C d ) 1 / 2 Equation (9) The unit of t in the above formula is hours, which is convenient for daily use and engineering design.

[0028] In the International System of Units (SI), the unit of time t is the second. For ease of daily use, H0 is used instead of y0 to represent the downward travel distance of the extreme point, i.e., H0 = y0. Then equations (6), (7), (8), and (9) can be normalized as follows: Q = yC d / (k L k)+V0t C G G0 / y, Equation (10) H0=y0=(kV0t k L C G G0 / C d ) 1 / 2 n0=[kV0t C d / (k L C G G0)] 1 / 2 Equation (11) Q min = 2[V0t C G G0C d / (k L k)] 1 / 2 Equation (12) H1=k L L0+(kV0t k L C G G0 / C d ) 1 / 2Equation (13) In equation (12), 2[V0t C] d C G G0 / (k L k)] 1 / 2 This is the minimum cost, including the total weight (energy block) and the stator section of the discharge stroke, and it is also the most basic (core) cost of the energy storage system (generating electricity).

[0029] Calculate the cost of the heavy block based on y0: y0*C d / (k L Calculate the cost of the stator section during the discharge stroke using k) and n0: n0*C G G0 / k, further analysis and derivation yield: Total weight cost Q G =Basic cost of discharge stroke section Q d =Q min / 2=[V0t C G G0C d / (k L k)] 1 / 2 Equation (14) Minimum cost formula Q min The rich physical implications it contains: when the total weight of the blocks, Q G The cost Q is equal to at least the cost of the stator or power drive system during the discharge stroke. d When the basic cost of discharge is minimized, Q min =2Q G =2Q d Equations (11), (12), and (14), along with the preceding equations (7), (8), (4), and (5), for the first time perfectly reveal, with a concise mathematical model (theoretical formula), the basic minimum cost required for complex gravitational potential energy power generation and the critical points of minimum values ​​of H0 and n0, as well as their inherent laws.

[0030] From this formula, we can see that the energy storage duration t, the initial velocity V0, and the unit weight cost of a single heavy block C are all related to the energy storage duration t, the initial velocity V0, and the unit weight cost of a single heavy block. G Weight of a single weight G0, cost per unit length of the stator C d All are constants. The most basic (core) minimum cost of an energy storage system (generating electrical energy) is only related to the speed increase factor k and the mover lengthening factor (or the stator unit length cost reduction factor) k. L The square root is inversely proportional to k, where k and k are... L As two key cost adjustment factors, these two levers make it easy to unify, compare, and design the energy storage system (solution) with the best cost performance. This is of great significance for guiding engineering design and application, and brings great convenience.

[0031] Table 1 k L Comparison of key indicators and economic analysis calculation results when =1 (1MW) Table 2k L Comparison of key indicators and economic analysis calculation results when =2 (1MW) The calculation basis for Tables 1 and 2 (derived from existing engineering experience): C G =0.02 million yuan / ton (based on composite bricks), V0=1; G0=102 tons, C h =278,000 yuan / meter, L0=4.68 meters, C L =385,000 yuan / meter.

[0032] The cost of the total weight can also be easily calculated (verified) separately from the calculation example. It can be seen that in the minimum discharge cost, the cost of the weight and the cost of the stator section during the discharge stroke each account for 50%, which are exactly equal. This is also the minimum value formula Q. min The rich physical implications are: when the cost of the total weight is equal to the cost of the stator section of the discharge stroke, it has a minimum value.

[0033] Having determined the minimum discharge cost, we can initially estimate the drive and control costs (excluding the costs of the storage yard, supports, and their construction) by using approximately (2-2.5) times the minimum discharge cost (this is only an empirical multiple). For t=4h, we can use 2.5 times; for t=8h, we can use 2.2 times; and for t=12h, we can use 2 times. It is evident that the longer the duration, the cheaper the cost.

[0034] The above analysis shows that the lower the operating speed, the greater the weight of the bulk material (and the lower the corresponding travel height), and the higher the total cost (both drive costs and yard support costs remain high), even making it an infeasible solution. However, current gravity energy storage systems generally operate at extremely low speeds of 0.1-0.5 m / s, resulting in single-trip lifting or lowering of energy blocks weighing tens or even hundreds of tons, which is unreasonable from the most economical and optimal operating perspective. This invention reveals that, within a certain range, appropriately increasing the operating speed can effectively reduce the weight of a single bulk material, the total weight of all bulk materials, and the total cost per trip. Furthermore, from the perspective of motors and frequency converters, high-speed operation is significantly more efficient and less expensive than low-speed operation (for example, at operating speeds of 2 m / s and 0.5 m / s, the latter's cost is even 2-3 times higher).

[0035] As can be seen from the above derivation and example analysis, by reasonably changing the (layout) operating speed, lowering distance, and geometric dimensions of the moving and stator parts according to the principles of this patent model and derivation formula, the weight of the heavy block can be reduced by at least 80%, and the cost of the core drive source linear motor can also be reduced by more than 85%, thus reducing both drive and support costs and making engineering implementation possible. The economic advantages are particularly evident for periods of 8 hours or more, where the energy storage market is currently either largely untapped or extremely costly.

[0036] The above model and minimum formula have clear physical meaning and conform to physical principles: the energy of a single lowering (or lifting) is W = Pt = GVt, where P is the power of a single lowering or lifting, P = GV. It is important to note that the driving force for a single lowering or lifting relies on electromagnetic power P and electromagnetic force F (equal to the weight G of the weight block, ignoring friction, wind resistance, and the elevator car, etc.). The number of weight blocks n plays a crucial role in the continuous operation for a duration t throughout the cycle, allowing the power P to be maintained for a long period. When energy W and time t are constant (given), the weight G of a single lowering weight block (energy block) is inversely proportional to the velocity V. As the velocity increases to V = kV0, the weight of the weight block decreases accordingly to G = G0 / k (G0 is the weight of the weight block at velocity V0).

[0037] We want the weight G of the weight block (energy block) to be as small as possible per single drop or lift, which means we need the speed V to be as large as possible. This also conforms to the principle P=FV, where the power P is constant, and the speed V (for a rotating motor, the speed is n) is constant. e The larger the torque (M) of a rotary motor, the smaller the force (F) and the speed (n) of a rotary motor. eThe smaller the value of the stator, the greater the force F (torque M for rotary motors). This is why, for the same power, low-speed (direct drive DD) motors are bulky and expensive. From the electromagnetic force formula F=ILB (where I is the current in the conductor, L is the conductor width, and B is the magnetic flux density), it can be seen that the thrust of a linear motor is directly proportional to the stator (moving element) width. By arbitrarily (k times) dividing the stator width, the motor thrust can be arbitrarily (k times) changed. Increasing the speed by a factor of K reduces the thrust to 1 / k of its original value, and the cost of the motor also decreases to 1 / k of its original value. Taking Tables 1 and 2 as examples, V0 = 1 m / s, G0 = 102 tons. When k = 25, V = 25V0 = 25 m / s, G = G0 / k = 4.08 tons. This means the electromagnetic force of the motor is reduced from 102 tons to 4.08 tons, and the size and cost of the motor are reduced to 1 / 25 of the original. If the width of the linear motor is 2000 mm, after a speed increase of k = 25 times, the width is only 80 mm, and the cost of the motor is significantly reduced by 96%. This means that the stator of the linear motor laid on the track becomes a long, thin strip similar to a railway rail. In large energy storage (potential energy mgH) systems with hundreds or even thousands of megawatt-hours of power, the stroke H is often hundreds of meters long. The savings in linear motors are unimaginable. Because the system only has one car (mover) doing work, the length of the mover coupled with the stator is generally only a few meters to a dozen meters. More than 90% of the stator laid on the track is wasted on hundreds of meters of travel. The core idea of ​​the slender strip segmentation method is that the thick-width motor is greatly elongated in the height direction of the stroke, equivalent to stretching a dough into thin noodles tens or even hundreds of meters long to extend the stroke. Therefore, this method is very suitable for long-stroke single-cabin direct-drive systems. However, the speed V cannot be increased indefinitely. H=Vt, and as the speed increases, the height H also increases. It is also necessary to consider that the height H cannot be too high due to various limitations, as well as the wind resistance, mechanical wear, and safety protection factors brought about by high-speed operation. Moreover, the minimum width of the linear motor cannot be segmented too small, otherwise the performance will deteriorate and it will be very uneconomical. Taking all factors into account, a more reasonable and economical speed must be selected.

[0038] like Figure 3-4 As shown, in addition to the k-fold speed increase, this invention also proposes to simultaneously increase k... L Doubling the length of the mover further reduces the cost of the linear motor. The physical meaning of this is to maintain the same output force of the mover (with equal coupling area S between the mover and stator: area S = height x width of the mover), k L While doubling the length of the mover, k can be obtained L The stator width is reduced by the same factor. Taking Table 1 and Table 2 as examples, in Table 1, k L =1, mover length L0 = 4.68 meters, stator cost 278,000 yuan / meter (width tentatively assumed to be 2000mm), k in Table 2 L =2, motor output remains unchanged, stator cost 27.8 / kL =139,000 yuan / meter, the length of the mover needs to be doubled L0'=k L x4.68 = 2 x 4.68 = 9.36 meters, the stator width is reduced by half: b0' = 2000 / k L =2000 / 2=1000mm, therefore, the cost of the linear motor on the track is reduced by 50%. We can also take k. L =4, the mover length is further increased: L0'=k L x4.68 = 4 x 4.68 = 18.72 meters, stator width: b0' = 2000 / k L =2000 / 4=500mm, therefore, the cost of the stator section is 27.8 / 4=69,500 yuan / meter, which further significantly reduces the cost of the motor. However, lengthening the mover will also lead to a significant increase in the size of the turntable, which needs to be considered comprehensively, and a suitable k should be selected. L Coefficients. Also note the differences between k and k. L A holistic approach is needed, rather than making a unilateral decision. For example, if we choose k first... L =2, then the motor width is 2000 / 2 = 1000mm. Then, taking k = 40, the desired motor width is 1000 / 40 = 25mm. However, this is practically impossible because there is a minimum reasonable width for motors (generally, depending on the pole pitch, the minimum width ranges from 30 to 100mm or even larger. For permanent magnet synchronous motors, speed is proportional to pole pitch; the higher the speed, the larger the pole pitch, and the larger the minimum width). If the width is too small, the motor performance will be very poor, making it uneconomical and impractical. Regarding this (limited by the minimum motor width, k and k...), L The product k L The problem that k may not be maximized is addressed in another invention patent filed on the same day: a single-column drive with multi-column support, which perfectly solves the problem and can fully maximize the utilization of the product k. L k enables the direct-drive energy storage system to achieve performance gains without degradation, while the cost of the track-side stator becomes very economical, or even close to the limit (possibly reduced by 98%), maximizing the economic and modular advantages of the "power reuse" direct-drive cycle architecture.

[0039] This invention uses a unique direct-drive cycle architecture with "power system reuse" as its core. In terms of physical topology, it has the genes of "extremely low cost" and intrinsic safety with "ultra-long life". "The longer it is stored, the cheaper the electricity and energy storage equipment become" - reshaping the industry's understanding, defining a new downward-sloping cost curve for long-term energy storage. It is not only about reducing costs, but also has the potential to become the preferred technical path for new power systems to solve the fundamental challenge of "large-scale spatiotemporal transfer of electricity (long-term storage)" and to achieve "cost reduction" in the long-term dimension (8-12 hours) and above. The economic advantages are further highlighted and amplified as the energy storage time increases.

[0040] Simultaneously, by rationally arranging multiple sets of single-unit (main structure) columns according to this invention, the structural force system can be completely changed, transforming the "cantilever" into a simply supported beam or continuous beam. This significantly reduces the internal forces of the components, saving over 50-60% of the total investment, significantly lowering the overall cost, and reducing the construction period by over 50% (from the usual 18-24 months to 9-12 months). Furthermore, by arranging the (main structure) columns into a two-way force grid, the shortest path transmission and uniform diffusion of loads can be achieved, achieving comprehensive optimization in terms of material usage, node construction, and ease of construction.

[0041] The underlying principles of this invention are highly compatible with the modular structure characteristics and advantages of linear motor direct drive systems, facilitating rapid assembly and transportation. It serves as a "Lego brick" in the energy equipment field, delivering standardized "heavy storage module" industrial products. Through the vertical stacking and horizontal parallel connection of modules, 10NWh-GWh level energy storage power stations can be flexibly constructed.

[0042] Core value: Transforming mega-projects into mass-producible, quality-controlled, and fault-isolated industrial standard parts.

[0043] Reliable assets: “hardcore assets” with a main design life of 40+ years, zero decay, and maintenance-free (main components), possessing the financial attributes of high-quality infrastructure.

[0044] This invention features a modular design, easy expansion, zero attenuation, zero resource constraints, all-weather operation, and "land-independent" functionality: adaptable to various scenarios and environments such as open fields, mountains, and abandoned mines, it is a "standardized industrial product" that can be flexibly and quickly deployed at the city, park, and user levels. It is inherently safe: modular direct drive, no heavy single-point transmission components; heavy loads are physically constrained by the track (and multiple protections); highly automated, it can operate unattended, making it easier to scale up and apply.

[0045] The above-mentioned ideas (principles / methods) of this invention are not only applicable to gravity energy storage systems with steel structures, but also to concrete load-bearing civil engineering projects (buildings), or energy storage systems combining steel structures and civil engineering projects (buildings), significantly reducing overall project costs and construction time. With large-scale application, it can save society tens of millions, or even hundreds of millions, of tons of non-renewable resources such as steel and cement annually, as well as a large amount of building land, and the resulting resource and environmental pollution and waste.

[0046] ---------The section following this dividing line represents a specific column-type gravity energy storage scheme applicable to the above method-------- The above design method can be applied to most gravity energy storage systems, but several more suitable linear motor gravity energy storage structures are especially needed.

[0047] like Figure 5-12 As shown, a column-type direct-drive circulating gravity energy storage system is described.

[0048] like Figure 5 , Figure 6 and Figure 12 As shown, the core architecture of the linear motor gravity energy storage system includes a robust steel structure base 1. This base 1 serves as the main load-bearing frame of the entire system and can be a hollow or solid steel column. Preferably, hollow steel columns (steel pipes) can be filled with cast concrete, offering excellent compressive and bending resistance, and significantly reducing support costs. At least two sets of vertical fixed guide rails 18 are provided on the sides of the base 1. In this embodiment, Figure 5 , Figure 6 and Figure 10 It showcases a more optimized "four-channel" configuration, namely, four sets of fixed section guide rails 18 are symmetrically arranged on the side of the base 1, arranged in a cross shape to maximize space utilization and throughput capacity. Figure 12 This demonstrates a simplified configuration of the "dual-channel" system. Of these fixed-section guide rails 18, at least one is an ascending channel and at least one is a descending channel.

[0049] A set of turntable structures 21 are fixedly installed at the top and bottom of the base 1, respectively. For example... Figure 7 , Figure 8 As shown, the turntable structure 21 is a large slewing support platform, and each turntable structure 21 has at least one rotatable track 181 rotatably mounted on it. The car 8 rolls or slides on the fixed guide rail 18 and the rotatable track 181, and can switch between the ascending and descending channels by rotating the rotatable track 181 on the turntable structure 21.

[0050] The system's energy carrier is the weight 14, which is transported by the car 8. A storage yard 22 is arranged around the sides of the turntable structure 21 at the top and bottom of the base 1. The upper and lower storage yards 22 are supported as follows: the bottom storage yard 22 can be placed directly on the ground or other independent supports; while the top storage yard 22 is supported by high-strength steel cantilever beams extending from the top structure of the base 1. These cantilever beams can be radially distributed and further reinforced with diagonal braces, stiffeners, etc., to enhance rigidity and stability. The feasibility of this design is fundamentally based on the "minimum cost" optimization model upon which this invention is based. This model, by adjusting parameters such as the speed factor k and the mover lengthening factor kL, significantly reduces the mass of a single weight 14 (e.g., from thousands of tons in traditional schemes to hundreds of tons) while maintaining the same energy storage capacity. The significant reduction in the total weight of the heavy blocks makes the use of steel structure cantilever support for the top storage yard an economical and safe solution, thereby eliminating the dependence of traditional gravity energy storage systems on monolithic giant concrete structures and achieving lightweight, modular and low-cost structures.

[0051] The structure of base 1 can be designed as a tower, frame, or a modified abandoned mine shaft, depending on site conditions. The number of channels is not limited to four or two sets and can be modularly increased or decreased according to power and capacity requirements. The material of the weight block 14 is preferably a low-cost composite brick (such as garbage or coal gangue).

[0052] like Figure 5 , Figure 7 and Figure 9 As shown, to achieve precise and smooth rotation of the rotatable track 181 on the turntable structure 21, at least one set of annular arc-shaped guide rails 6 (preferably at least two concentric rings) are fixedly connected to the surface of each turntable structure 21. The cross-section of the arc-shaped guide rail 6 can be T-shaped, I-shaped (flat guide rail), I-shaped, concave, convex, isosceles trapezoidal guide rail, ball guide rail, or roller guide rail. Correspondingly, an arc-shaped guide rail slider 7 that mates with the aforementioned arc-shaped guide rail 6 is fixedly connected to the bottom of the rotatable track 181. The slider 7 or guide wheel preferably contains balls or rollers, allowing it to slide or roll along the arc-shaped guide rail 6 with low friction, thereby constraining the rotatable track 181 so that it can only rotate around the center of the turntable.

[0053] The power driving the turntable's rotation can preferably be an integrated arc-shaped linear motor, which has the advantage of fast response speed. For example... Figure 8-9As shown, a ring-shaped linear motor stator 4 is fixedly mounted on the turntable structure 21 and on the rotatable track 181. A matching arc-shaped linear motor mover 5 is also fixedly mounted on the turntable structure 21. One feasible solution is that the mover 5 is typically composed of a permanent magnet array. When the stator 4 is energized, the resulting traveling wave magnetic field interacts with the permanent magnetic field of the mover 5, directly generating a tangential electromagnetic force that drives the rotatable track 181 and the car 8 on it to rotate, completing the channel switching. This method eliminates the need for traditional rotary motors, reducers, gears, and other intermediate transmission components, resulting in high efficiency, precise control, and simple maintenance. The turntable drive can also use multiple servo motors driving gears that mesh with the external gear ring of the slewing bearing instead of linear motors. The guide structure can also be directly integrated with a large slewing bearing instead of separate arc-shaped guide rails and sliders.

[0054] like Figure 6 , Figure 7 and Figure 11 As shown, the vertical lifting motion of the system is accomplished by another linear motor. Specifically, a non-rotatable stator 20 is fixedly installed along the entire height of each fixed section of the guide rail 18. Similarly, a rotatable stator 17 is fixedly installed along the entire height of each rotatable section of the track 181. One feasible solution is that stator sections 17 and 20 are both primary structures with three-phase windings embedded inside. A linear motor mover 3 is fixedly connected to the back of the car 8 (i.e., the side facing the guide rail). This mover 3 is a secondary structure and can typically be composed of a high-performance permanent magnet array.

[0055] When the car 8 is positioned on the fixed guide rail 18, its mover 3 and the non-rotatable stator 20 form a linear motor. When a controlled current is applied, it generates a vertical electromagnetic thrust, driving the car upwards (electric operation / power consumption) or controlling its uniform descent (power generation / energy feedback). When the car 8 rotates with the rotatable track 181 to the switching position, its mover 3 pairs with the rotatable stator 17, operating on the same principle. This design allows the drive mechanism to be fully integrated between the car and the track, eliminating the need for additional wire ropes and winches, resulting in extremely high transmission efficiency and direct, rapid thrust control.

[0056] like Figure 5-7 and Figure 10-11 As shown, the car 8 is the core transport vehicle of the system. Its front end can be designed with a sturdy platform, preferably a roller conveyor mechanism held by two side plates, to support the weight 14. Sensors 13 (such as pressure sensors or photoelectric sensors) are installed between the two side plates of the platform to detect whether the weight 14 is in position. Electromagnets 11 are also embedded between the two side plates of the platform, controlling the electromagnets to drive the locking pins to prevent the weight 14 from slipping during acceleration, deceleration, or in case of accidents.

[0057] The rear of car 8 houses the crucial motion guidance mechanism. For example... Figure 11 In detail, both the guide rail 18 and the rotatable track 181 preferably adopt a standard I-beam steel structure, which has the advantages of high strength and good stability. The main body at the rear of the car 8 is an inverted U-shaped thick steel plate with its opening facing inward, which perfectly covers the belly of the I-beam steel structure guide rail. The positioning wheel set 19 is installed on the inner sides of this U-shaped plate.

[0058] The positioning wheel assembly 19 includes main positioning wheels 191 and side positioning wheels 192. At least two sets (usually arranged vertically) of main positioning wheels 191 are provided on each of the inner sides of the U-shaped plate. The wheel surfaces of these main positioning wheels 191 extend into the space between the web of the I-beam and the side flanges (cross plates), and their rims are tightly abutted against the inner surfaces of the two flanges (cross plates) of the I-beam. This design primarily bears the lateral force in the horizontal direction, preventing the car from swaying left and right. Simultaneously, at least one side positioning wheel 192 is provided on each of the inner sides of the U-shaped plate, next to the main positioning wheels 191. The wheel surfaces of the side positioning wheels 192 are perpendicular to the main positioning wheels, and their rims abut against the outer end faces of the I-beam flanges (cross plates). This design primarily bears the normal force between the moving and stating elements and the overturning moment in the front-to-back direction of the car, preventing the car from swaying back and forth. The coordinated action of the main and side positioning wheels ensures the stability and guidance of the car 8 during high-speed lifting and lowering.

[0059] A brake 16 is also installed on the U-shaped plate structure. It can be a disc brake or a caliper brake, or it can be a mechanical latch or a hydraulic clamping device. Its brake pads act on the brake disc fixed on the guide rail or directly clamp the flange of the I-beam. The brake 16 is used for emergency stopping, power failure protection, or precise parking at a designated position.

[0060] like Figure 5 , Figure 7 , Figure 10 and Figure 12 As shown, stockpile 22 is a heavy block storage and transfer system. It is specifically composed of modular combinations of standardized conveying equipment from existing technologies: The second conveying unit 15 is a multi-segment arc-shaped roller conveyor mechanism, connected end to end and surrounding the side of the turntable structure 21. Each segment of the roller conveyor consists of a series of rollers driven by a motor or other drive equipment, used to store and convey stationary weights 14 along a circular path.

[0061] Transfer and conveying unit 12: It is located between two adjacent sections of the second conveying unit 15. It is a circular roller conveyor platform that can rotate around its own center. When the weight 14 is conveyed from one section of the arc-shaped roller conveyor to the end, the transfer and conveying unit 12 receives it, rotates it by a certain angle (such as 90 degrees), and then conveys it to the next section of the arc-shaped roller conveyor, or receives and conveys it between the second conveying unit 15 and the first conveying unit 9, thereby realizing the flow and station change of the weight in the circular stockpile.

[0062] The first conveying unit 9 is a straight roller conveyor mechanism, with one end aligned with the platform of the car 8 on the rotatable track 181, and the other end connected to the transfer conveying unit 12. Its function is to transfer the heavy block 14 between the car 8 and the storage yard 22. That is, when the car 8 loads or unloads the heavy block, the first conveying unit 9 is activated to push the heavy block 14 into the platform or pull it out of the platform.

[0063] The working process of the system of this invention is divided into two modes: energy storage (charging) and energy release (power generation). Its essence is the cyclical transport of energy blocks (heavy blocks) 14 between the upper and lower storage yards. Energy storage process (surplus electrical energy from the power grid → potential energy storage): The heavy block 14 located in the lower storage yard 22 (ground level) is transported by the storage yard conveying system (second conveying unit 15, transfer conveying unit 12, first conveying unit 9) to the platform of an empty car 8 located on the rotatable track 181 of the bottom turntable structure 21, and is fixed (blocked) by the de-energized pin of the electromagnet 11, while being aligned with an empty "ascending channel" (fixed section guide rail 18).

[0064] When the linear motor mover 3 on the car 8 and the non-rotatable stator 20 of the ascending channel are energized, the linear motor generates a strong upward electromagnetic thrust, driving the car 8 carrying the weight 14 to rise vertically at high speed.

[0065] When car 8 reaches the top position, electromagnet 11 is energized to open the self-locking pin and release weight 14. The first conveying unit 9 transfers weight 14 from the car platform to the annular storage system in the upper storage yard 22. The empty car 8 is then ready for the next cycle. At this point, electrical energy has been converted into the gravitational potential energy of the weight and stored.

[0066] Energy release process (potential energy release → electrical energy feedback to the power grid): The process is the reverse of energy storage. The heavy blocks 14 in the upper storage yard 22 are transported to an empty car 8 at the top turntable station, while being aligned with a "lowering channel".

[0067] Under the control of the control system, the car 8 begins to descend at a controlled and uniform speed. At this time, the gravitational potential energy of the weight is used to cut the magnetic field of the stator 20 by the moving part 3 driven by the car, and an induced electromotive force (power generation) is generated in the primary winding of the linear motor. This electrical energy is then fed back to the power grid after being processed by the converter system.

[0068] After the car 8 reaches the bottom, the heavy block 14 is unloaded to the lower storage yard 22, completing one energy release cycle.

[0069] The above describes the minimum system structure for a single-layer storage yard. Under the premise of adopting the "minimum cost" optimization model of this invention and a small energy storage capacity, the total weight of the heavy blocks is significantly reduced (for example, from thousands of tons in the traditional scheme to hundreds or tens of tons). Although the single-column cantilever support for the top single-layer storage yard has certain feasibility, it still has its limitations: the storage yard area is often hundreds of square meters, with not only a large number and weight of heavy blocks, but also a considerable number and weight of transfer equipment. The excessive extension length of the cantilever beam causes the support column to bear huge bending moments, resulting in a large volume and a sharp increase in cost. It also has weak high-altitude wind resistance, high risk, and limited energy storage capacity.

[0070] The above problems can be effectively solved by applying the concept of multi-layer storage yards: Figure 13 This diagram illustrates the evolution (comparison) from a single-level to a multi-level storage yard. The single-level storage yard is vertically decomposed into a multi-level yard, for example, a 9-level sub-yard or smaller storage yard. Correspondingly, the original large blocks are also divided into smaller blocks and stored in the multi-level sub-yards. The storage car system can be modified to a multi-level (e.g., 9-level) car system, or multiple (e.g., 9) single-level cars can operate synchronously with the multi-level (e.g., 9-level) sub-yards (smaller blocks). The lower storage yard is also set up in the same multi-level manner (extending underground), significantly reducing the footprint (approximately 90% reduction with a 9-level storage yard). Each small platform has an area that is only 1 / 9 of the original single-layer platform area, and the extension length of the single-layer cantilever beam is reduced to 1 / 3 of the original length. For example, it can be significantly reduced from 5 meters to 1.667 meters. Moreover, the multi-layer storage platform is equivalent to a multi-layer ring beam, providing more lateral support points. The strength and stress (bending resistance, wind resistance, etc.) of the support columns are greatly improved, and the design has been changed from mainly bending resistance to compression resistance. The overall material and construction (including foundation) costs can be reduced by more than 50-60%, and the high-altitude wind resistance and stability are significantly enhanced, resulting in a larger energy storage capacity.

[0071] Figure 14 This diagram illustrates the principles of multi-level storage yards, multi-level cars, and single-level cars (compare). It can be used with multiple cars (single mover) or multiple single-level cars (multiple movers), suitable for different occasions and uses. For example, when the mover is too long and the speed multiplication factor is too large, or the mover (turntable) length is too long, it can be divided into multiple mover segments (multiple cars) for different occasions and uses. For example, by increasing the number of movers and cars, the power can be increased arbitrarily, making it very flexible and convenient to use.

[0072] Figure 15 A schematic diagram illustrating the principle of reducing the velocity by a factor of k, increasing the length of the mover by a factor of k, and reducing the total area of ​​the stockpile (for the same single heavy block) by a factor of k while increasing the number of stockpile layers by a factor of k (shown as k=2). It can be seen that, with a velocity reduction of a factor of k and a mover length increase of a factor of k, according to the minimum formula of this invention, the product of the adjustment factors k... L k remains unchanged, the optimal discharge stroke height H0 remains unchanged, and the minimum discharge basic cost Q remains unchanged.min The total weight of the stockpiles (for the same single stockpile) remains unchanged, but the stockpile area decreases by a factor of k and the number of stockpile layers increases by a factor of k. This feature is very useful and convenient in practical applications for adjusting the optimal movement speed and mover length, as well as for stockpile design.

[0073] Due to the significant reduction in the total weight of the optimized weight blocks, the area of ​​each storage yard platform, and the span of the cantilever beams, the total load of the storage yard remains within the safe bearing capacity of the steel structure, achieving stable and reliable support. This is the key to the significant reduction in support and civil engineering costs of this solution. The system achieves continuous and efficient charging and discharging functions through the circulating flow of multiple cabins in multiple channels.

[0074] ---------The section following this dividing line represents a specific well-type gravity energy storage scheme applicable to the above method-------- As attached Figure 16-20 As shown, another feasible solution is proposed. For the underground environment, the upper storage yard does not need to be equipped with the high-cost main support column of the column structure. The upper storage yard can rely entirely on the strong ground as support. Therefore, a well-type direct-drive circulating gravity energy storage system is proposed. It should be noted that some components of this solution are the same or similar to those in the aforementioned column solution. Therefore, the same reference numerals are used to avoid repetition.

[0075] As attached Figure 16-17 As shown, a well-type direct-drive circulating gravity energy storage system has its core architecture based on fully utilizing existing or specially excavated well structures, with the main working parts of the system located within these wells. The top of the well is the surface layer, while its bottom is typically an underground space formed at a certain depth (such as hundreds to thousands of meters), with the bottom of the well widening outwards to form underground layers.

[0076] Unlike the aforementioned solutions that rely on one or more extremely high-strength, expensive independent steel main columns to support all drive equipment (such as the stator), this invention utilizes the unique characteristics of the downhole environment. The wellbore's own rock and soil support structure or permanent lining (such as concrete well walls) possesses natural and strong load-bearing capacity. Therefore, as Figure 16 and Figure 18 As shown, multiple sets of fixed-section guide brake rails 18 can be directly installed and fixed against the inner wall of the shaft. This means that the weight and load of the entire vertical channel's support structure (including the fixed-section guide brake rails 18 and their attached non-rotatable stator 20) are mainly borne by the ground around the shaft, thus completely eliminating the huge cost of constructing independent high-strength support columns. This is the key to the economic breakthrough of this solution. The shaft can be converted from an abandoned mine or a newly built vertical or inclined shaft. For newly built shafts, their cross-sectional shape is not limited to a circle; it can also be elliptical, rectangular, or polygonal to adapt to different geological conditions and equipment layouts.

[0077] At least two sets of fixed-section guide brake rails 18 are installed along the height direction of the well body wall. At least one set serves as the lifting channel (ascending channel) for the car 8, and at least the other set serves as the lowering channel (lowering channel) for the car 8. The car 8 is configured to cooperate with the fixed-section guide brake rails 18 via its guiding and braking mechanisms. A set of annular rotating supports 23 is installed at both the ground level and the underground level. Figure 17 and Figure 18 As shown, each annular rotating support 23 is rotatably equipped with at least two rotatable tracks 181. The car 8 can stop on these rotatable tracks 181 and rotate with them, thereby switching from the ascending channel position to the descending channel position, or vice versa, forming a loop path.

[0078] The system's energy carrier is a modular weight 14. Inside the well body, such as on the surface level well wall or utilizing the bottom space, a temporary storage area 24 is fixed (non-rotatable) or rotatable. This is primarily used to temporarily store weights 14 that are about to be loaded by the car 8 or have just been unloaded. Outside the well body, the surface or underground space surrounding the temporary storage area 24 is used as a long-term storage area 25 for large-scale, long-term storage of weights 14. Multiple conveying units (transfer conveying units 12) are installed on each storage area. These units can be connected end-to-end along the conveying direction to form a continuous conveying channel, enabling the transfer of weights 14 within the storage area and between the storage area and the car.

[0079] The principle (idea) for setting up storage yards is that the top surfaces of long-term storage yards 25 and temporary storage yards 24 (including their conveying units) must be at the same height (located on the same horizontal plane) to ensure that the heavy blocks 14 can enter and exit smoothly and quickly throughout the entire transfer process.

[0080] Long-term storage yard 25: Located on the ground or underground plane (space) around the well body, it preferably has multiple conveying units arranged in an array (ring array). These conveying units can be connected to form one or more continuous external conveying channels around the well body for long-term, orderly storage and transfer of heavy blocks 14.

[0081] Temporary storage yard 24 has both rotatable and non-rotatable structures.

[0082] The rotating temporary storage area 24 is designed using the base plate of the "rotatable birdcage," specifically the base plate within the annular rotating support 23, as the rotating temporary storage area 24. This base plate (rotatable temporary storage area 24) is fixed to the rotating support column 195 within the annular rotating support 23 and the connecting ring beam 196 between the rotating support column and the rotating support column. As the annular rotating support 23 rotates, the ground (foundation) surrounding the base plate (rotatable temporary storage area 24) serves as the long-term storage area 25, with both surfaces maintaining the same height. The base plate (rotatable temporary storage area 24) has dedicated workstations for the car 8 to stop (specifically, these workstations are through holes for unobstructed access for the car 8, and are configured in conjunction with the fixed section guide brake rail 18). Conveying units are installed to the sides of these workstations or within the plane of the temporary storage area. These units connect to form one or more continuous internal conveying channels, specifically serving the rapid loading and unloading operations of the car 8.

[0083] Internal and external channel connection: The external and internal conveying channels are connected by at least one set of connecting conveying units, thus forming a complete logistics loop from long-term storage to temporary loading and unloading.

[0084] The annular rotating support 23 is the core mechanism for realizing channel switching, and its specific structure includes: Column 26: As a static support core, its base is securely fixed to the ground or underground foundation of the (adjacent temporary storage yard) by anchor bolts or similar means.

[0085] Drive and guide components: At least two concentric annular guide braking components are fixedly connected from top to bottom on the column body of the support column 26. The middle layer (which can also be set on the upper layer, lower layer, or other heights) is an arc-shaped guide braking rail 180 with an arc-shaped linear motor stator 4. A linear motor mover 5 is set on the rotatable support column 195 and / or the connecting ring beam 196 between the rotatable support columns 195 to form the drive power source of the annular rotating bracket 23. The upper and lower layers are arc-shaped guide rails 6. The back of the rotatable rail 181 is fixedly connected to an arc-shaped guide rail slider 7 or guide wheel, which contains rollers or bearings and is set to roll or slide along the arc-shaped guide rail 6. The bottom of the column body of the support column 26 is lower than the ground floor or underground floor plane and is equipped with a set of arc-shaped guide rails 6, which cooperate with the arc-shaped guide rail sliders 7 to form a buried (hidden) positioning and guiding mechanism. The purpose of burying is to prevent the lower edge of the annular rotating support 23 (annular guide rail, ring beam, slider, etc.) from blocking and interfering with the smooth and stable entry and exit of the weight block 14, so as to ensure that the upper surface of the inner bottom plate (rotatable temporary storage yard 24) of the annular rotating support 23 is consistent with the upper surface of the outer long-term storage yard 25.

[0086] For ground-mounted rotatable temporary storage yards, the installation height of the connecting ring beam 196 and / or the arc-shaped linear motor located between the arc-shaped guide rails 6 and 180 and / or the rotatable support columns of the annular rotating support 23 above the ground level, i.e., the minimum vertical distance between them and the top surface of the conveying unit of the temporary storage yard 24, must be greater than the maximum height of a single weight 14. This design is crucial to ensure that when the annular rotating support 23 is intermittently stationary, the weight 14 can move freely and unobstructed within and outside (long-term and temporary) storage yards to complete rapid loading and unloading, avoiding interference and achieving three-dimensional interaction in space.

[0087] For ground-mounted rotatable temporary storage yards, underground temporary and long-term storage yards can adopt the same (symmetrical) structure as the ground surface, or they can be set as non-rotatable structures, just like the non-rotatable (fixed) temporary storage yards, directly utilizing the strong and solid underground plane (foundation) at the bottom of the well to set up underground temporary and long-term storage yards.

[0088] Non-rotatable (fixed) temporary storage area: The design concept can be simply understood as the manhole covers (of sewers) commonly found on roads. The manhole cover serves as a temporary storage area, while the surrounding road surface at the same height serves as a long-term storage area. A circular, elliptical, square, or polygonal manhole cover (with an inscribed circle diameter generally 10-50% larger than the manhole diameter, covering the manhole area) is installed above the manhole opening as a temporary storage area 24. A supporting framework, either built-in or constructed of steel or brick-concrete, can be laid beneath the manhole cover (temporary storage area 24). This framework relies on the surrounding ground (foundation) to reliably support the manhole cover (temporary storage area 24). Alternatively, the manhole cover (temporary storage area 24) can also rely on the manhole wall (avoiding the vertical lifting track) along the lower edge of the manhole for support, or on the manhole wall and / or the ground for support. In this case, the inscribed circle diameter of the manhole cover can be smaller than the manhole diameter. The remaining parts (ground or foundation) surrounding the manhole cover (temporary storage yard 24) serve as the long-term storage yard 25. The temporary storage yard 24 and the long-term storage yard 25 are located at or essentially on the same horizontal plane, with or without gaps between them. That is, the long-term storage yard 25 can cover the manhole opening and be integrated with the manhole cover (temporary storage yard 24) without gaps. Generally, a gap setting scheme is preferred, with the manhole cover (temporary storage yard 24) set up separately to facilitate the maintenance and transportation of bulk materials (facilities). As needed, the inner and outer storage yards can also maintain a very small inclination angle, such as the outer side being higher than the inner side, to facilitate the entry of heavy blocks into the temporary storage yard at a small inclination angle (but the inclination angle should not be too large to avoid the heavy blocks slipping uncontrollably), reducing the power loss of heavy blocks during transfer. The aforementioned rotatable temporary storage yard and its long-term storage yard can also be designed to enter at such a small inclination angle as needed. As for the temporary storage yard 24 and the long-term storage yard 25 underground, since there are no suspended areas that need to be supported, the setting up of the storage yard becomes extremely simple and easy. It can be set up directly using the strong and solid ground (foundation) at the bottom of the well, so I will not go into details.

[0089] The manhole cover (temporary storage yard 24) includes a supporting frame with a dedicated parking space for the car 8 (specifically, a through-hole for unobstructed access for the car 8, which is configured in conjunction with the fixed section guide brake rail 18). Conveying units are located to the sides of these parking spaces or within the plane of the manhole cover (temporary storage yard 24). These units connect to form one or more continuous internal conveying channels, specifically serving the rapid loading and unloading operations of the car 8.

[0090] The annular rotating support 23 is located directly above the manhole cover (temporary storage yard 24) and can rotate freely above it. The bottom of the annular rotating support 23 (bottom plane) and the upper surface of the manhole cover (temporary storage yard 24) are fitted with a clearance.

[0091] For non-rotatable temporary storage yards, the main structure of the annular rotating support 23 is the same as that of the rotatable temporary storage yard. The main difference is that the buried (hidden) positioning and guiding mechanism is eliminated and moved to the middle and upper part of the annular rotating support 23. This is to prevent the lower edge of the annular rotating support 23 (annular guide rail, ring beam, slider, etc.) from obstructing and interfering with the smooth and stable entry and exit of the weight 14. In addition, the installation height of the connecting ring beam 196 and / or the arc linear motor between the arc-shaped guide rails 6 and 180 and / or the rotatable support column of the annular rotating support 23 above the ground level, that is, the minimum vertical distance between them and the top surface of the manhole cover (temporary storage yard 24) conveying unit, must be greater than the maximum height of a single weight 14. This design is crucial to ensure that when the turntable is stationary, the weight 14 can move freely in and out of the storage yard (long-term and temporary) to complete rapid loading and unloading without obstruction, avoiding interference and realizing three-dimensional interaction in space.

[0092] The vertical lifting of the system is directly driven by another set of linear motors, similar to a column structure, specifically: Stator mounting: A non-rotatable stator 20 is fixedly mounted along the entire length of the fixed section guide brake rail 18. Simultaneously, a rotatable stator 17 is fixedly mounted along the rotatable track 181. Preferably, a long primary (or long secondary) structure is used.

[0093] Mover installation: A linear motor mover 3 is fixedly installed at the back of the car 8, which has a short secondary or short primary coil structure.

[0094] When the car 8 is running on the fixed section guide brake rail 18, its mover 3 and the non-rotatable stator 20 form a linear motor to provide upward power or control downward power generation. When the car 8 stops on the rotatable rail 181 and rotates accordingly, its mover 3 is paired with the rotatable stator 17. This arrangement achieves direct drive without intermediate transmission losses.

[0095] Track structure: The main body of both the fixed section guide brake rail 18 and the rotatable rail 181 adopts the fixed section guide brake rail structure. The arc-shaped guide rail 6 is a fixed section guide brake rail bent to the required radius.

[0096] Car connection: A high-strength U-shaped steel plate is connected to the rear side of the car 8 (and the moving part of the rotatable track 181). The opening of the U-shaped plate faces inward and just covers the web plate and part of the outer flange of the fixed section guide brake track. The structure of the car 8 can be completely adopted from the car 8 structure in the front column structure.

[0097] The bottom of the car can be equipped with a follow-up conveying unit, which works in conjunction with the conveying unit of the temporary storage yard 24 to complete the loading and unloading of heavy blocks.

[0098] Positioning wheel set: as attached Figure 11 , 20 A positioning wheel assembly 19, comprising main positioning wheels 191 and side positioning wheels 192, is installed inside the U-shaped plate. The flanges of multiple main positioning wheels 191 extend between the two flanges (cross plates) of the fixed section guide brake rail and abut against its inner surface to constrain the lateral horizontal movement of the car. The side positioning wheels 192 are installed on both sides of the U-shaped plate, their surfaces abutting against the outer end faces of the flanges of the fixed section guide brake rail to constrain the forward and backward sway of the car. This multi-wheel cooperative layout ensures stability and operational accuracy under heavy load conditions. Simultaneously, similar to a column-type structure, working brakes can be installed on the two flanges (cross plates) of the guide brake rail at the car and the rotating part of the annular rotating support for braking (stopping) the car and the rotating part of the annular rotating support.

[0099] The transfer and conveying unit 12 is a mature piece of existing technology. As described in claim 8, its basic structure includes a support fixedly installed on the ground, on which a turntable capable of horizontal rotation is driven by a slewing bearing or similar mechanism. A roller conveyor mechanism, i.e., a conveying surface composed of multiple parallel rollers, is installed on the top surface of the turntable. The rollers are driven by a motor to rotate in the same direction, thereby conveying the weight 14 on them in a linear motion. The rotation of the entire turntable unit is coordinated with the rotation of the rollers, enabling the weight 14 to be received from one radial direction, rotated a certain angle, and then delivered from the other radial direction, completing the reversal and transfer functions. This turntable roller conveyor mechanism (equipment) is widely used in automated warehousing and logistics systems, but may not be the optimal conveying mechanism. This invention only describes the basic working principle and process in principle; specifically, existing sorting (transfer) equipment with more suitable, mature, and lower energy consumption technologies in the logistics and automation fields can be preferred.

[0100] Access to the temporary storage yard: The annular rotating support operates intermittently. The heavy-load car descends from the temporary storage yard at the shaft opening to the temporary storage yard at the bottom of the shaft (simultaneously, the empty car is lifted from the temporary storage yard at the bottom of the shaft to the temporary storage yard at the shaft opening). This process requires a certain amount of time, denoted as t0 (generally greater than 10 seconds). During this interval t0, the annular rotating support 23 at the shaft opening and bottom remains stationary. Heavy blocks from the ground and the long-term storage yard at the bottom of the shaft can freely enter the temporary storage yard of the annular rotating support 23 via internal and external conveying units and reach the designated stopping position of the car 8. During this process (because the temporary storage yard is located within the circular area enclosed by at least two support columns of the annular rotating support), access to the temporary storage yard and the long-term storage yard is easy and free from the open space or open passage between any two support columns of the annular rotating support (i.e., as long as a few support columns are avoided), without causing interference.

[0101] The system operates as a continuous energy storage and release cycle: Energy storage process (charging): The heavy block 14 located in the underground long-term storage yard 25 is transported to the inner conveying channel of the underground temporary storage yard 24 via the outer conveying channel and the conveying unit 12, and arrives at the designated loading position.

[0102] The car 8, located in the underground level and in an unloaded state, is rotated by the underground annular rotating support 23 to align with the loading position and simultaneously align with an ascending channel (fixed section guide brake rail 18).

[0103] The weight 14 is pushed into the platform of the car 8 and fixed by the conveying unit.

[0104] The linear motor mover 3 on the car 8 interacts with the non-rotatable stator 20 of the ascending channel. When the linear motor is energized, it generates an upward electromagnetic thrust, driving the car 8, which carries the weight 14, to rise vertically at high speed to the unloading position at the wellhead surface layer.

[0105] The heavy block 14 is unloaded to the temporary ground storage area 24, and then transferred to the long-term ground storage area 25 via a conveyor unit. At this point, electrical energy is converted into the gravitational potential energy of the heavy block and stored. Then, the empty car 8 is rotated to the lowering channel (fixed section guide brake rail 18) via the ground annular rotating support 23 and can be lowered to the underground level to start the next cycle.

[0106] Energy release process (power generation): The process is the reverse of energy storage. The heavy blocks 14 of the ground long-term storage yard 25 are transported to the car 8 inside the ground annular rotating support 23.

[0107] When the loaded car 8 is lowered, its moving rotor 3 cuts the magnetic field of the stator 20 in the lowering channel, generating an induced electromotive force in the primary coil, which then feeds back electrical energy to the power grid or load through the converter.

[0108] Heavy block 14 was unloaded into underground long-term storage yard 25, completing the release of potential energy.

[0109] The power drive device of the gravity energy storage system described in this invention can be a linear motor or a rotary motor gear rack transmission mechanism (equivalent to replacing the stator and mover of the linear motor with a rack and a gear driven by a rotary motor, respectively).

[0110] The gravity energy storage system described in this invention can also be a continuous circulation system consisting of at least one ascending channel and at least one descending channel, equivalent to replacing the turntable with a turning section or automatic switch. It also includes a closed track composed of straight and curved sections, a stator section consisting of straight and curved section unit stators arranged along the closed track, and a mover section consisting of one unit mover or multiple unit movers flexibly connected by hinges (for convenient turning and continuous high-speed circulation). The one or more unit movers are fixedly or flexibly connected to one or more cars, perfectly cooperating with the multi-layered storage yard of this invention to achieve efficient and continuous descent or elevation of the heavy blocks. This invention can also be a reciprocating system driven by a wire rope hoisting, traction, or chain drive device consisting of at least one ascending channel and one descending channel. At least two cars reciprocate up and down to achieve periodic descent or elevation of the heavy blocks. Multiple systems operate in coordination to achieve continuous descent or elevation of the heavy blocks.

[0111] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several changes and improvements without departing from the overall concept of the present invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. A gravity energy storage system based on a minimum value model and its design method, characterized in that, The gravity energy storage system includes at least: The support frame serves as the supporting skeleton for the entire system. The car body is raised and lowered in coordination with the support frame. The power drive unit includes a stator, which is fixed to a support frame and extends along the travel direction; it also includes a mover, which is fixed or flexibly connected to the car and cooperates with the stator to form a power drive system. Upper storage yard, lower storage yard, and heavy blocks used as energy storage medium; The design method includes the following steps: S1. Based on the target energy storage power P of the gravity energy storage system, set the reference speed v0 during discharge, the reference mass G0 of a single weight, the reference length L0 of the mover, and the reference cost C per unit length of the stator. d Benchmark value C for unit length of moving part L ; S2, Set the speed multiplier k and the mover lengthening multiplier k L This results in the running speed v = k·v0 and the mover length L = k L • L0, the mass of a single heavy block G = G0 / k; S3. Set the discharge stroke y, calculate the single-stroke discharge time t0=y / (k·v0), and calculate the total number of weights n=k·v0 t / y based on the target energy storage time t of the gravity energy storage system; S4. Based on S1, S2, and S3, establish a basic discharge cost function Q, wherein the basic discharge cost includes at least the total weight cost and the basic cost of the discharge stroke segment. S5. Solve for the minimum value of the basic discharge cost function Q to obtain the optimal discharge stroke y0 and the optimal number of heavy blocks n0. S6. Based on the optimal stroke y0 and the optimal number of weights n0, apply the adjustment multiples k and k L The parameters of the system's operating speed v, mover length L, and single-load weight G are optimized and adjusted so that the overall cost of the drive section or the entire energy storage system tends to be the lowest or optimal while meeting the requirements of the target energy storage power P and the target energy storage duration t.

2. The design method as described in claim 1, characterized in that: The basic discharge cost function Q is defined by the following expression: Q= y C d / (k L k)+V0t C G G0 / y Among them, C G Cost per unit weight of the heavy block.

3. The design method as described in claim 2, characterized in that: The minimum point is determined by solving for the derivative of the basic discharge cost function Q and setting the derivative to zero. The second derivative is also greater than zero to verify that it is a minimum. The minimum value of Q is Q_min. min Defined by the following expression: Q min = 2[V0t C G G0C d / (k L k)] 1 / 2 。 4. The design method as described in any one of claims 1-3, characterized in that: k L While doubling the length of the mover, at k L The stator width is reduced by the same factor to maintain a constant lifting force.

5. The design method as described in any one of claims 1-3, characterized in that: While increasing the speed by a factor of k, the mass of a single heavy block is reduced by the same factor of k, G = G0 / k, to maintain constant power.

6. The design method as described in claims 1-3, characterized in that: Based on the value of k and k L The value determines the optimal value of the discharge stroke: y0=(kV0t k L C G G0 / C d ) 1 / 2 ; Based on the value of k and k L The value determines the optimal number of duplicate blocks: n0=[kV0t C d / (k L C G G0)] 1 / 2 。 7. The design method as described in claims 1-3, characterized in that: When the total cost of the weight is Q G The cost Q equals at least the cost of the stator or power drive system during the discharge stroke. d At that time, the basic discharge cost has a minimum value Q. min And Q min =2Q G =2Q d .

8. The design method as described in claim 1, characterized in that: The gravity energy storage system is a circulating operating system consisting of at least one ascending channel and at least one descending channel. The stockpile adopts a single-layer structure or is vertically divided into at least two sub-stockpile layers. The car has a single-layer loading space or is vertically divided into at least two loading spaces. Each single-layer or layer of loading space is used to carry a heavy block and docks with the corresponding layer of stockpile for loading or unloading the heavy block. The top and bottom of the drive frame are respectively provided with upper and lower turntables or transfer mechanisms that allow the car to switch positions between the ascending channel and the descending channel. The car, through the upper and lower turntables or transfer mechanisms, cooperates with the upper and lower stockpile layers to realize the cyclic descent or ascent of the heavy block.

9. The design method as described in claim 1, characterized in that: The gravity energy storage system is a continuous circulation system consisting of at least one ascending channel and at least one descending channel. It includes at least two cars, upper and lower storage yards, a closed track consisting of straight and curved sections, a stator section consisting of straight and curved stator units arranged along the closed track, and a mover section consisting of one unit mover or multiple unit movers flexibly connected by hinges in cooperation with the stator section. The one or more unit movers are fixedly or flexibly connected to one or more cars and cooperate with the upper and lower storage yards to realize the cyclic descent or elevation of the heavy blocks.

10. The design method as described in claim 1, characterized in that: The power drive device of the gravity energy storage system is at least one of the following: a linear motor, a rotary motor gear and rack transmission mechanism, a wire rope lifting device, a traction transmission mechanism, or a chain transmission mechanism.

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