Underground gravity energy storage shaft and chamber spatial arrangement structure
By optimizing the design of the number, spacing, and shape of the heavy block storage chamber group, the transportation chamber group, and the connecting section chamber, the problem of the difficulty in long-term stable operation of the underground gravity energy storage well shaft and chamber layout scheme in the existing technology has been solved, and safe and stable operation under the conditions of ground stress and surrounding rock excavation disturbance has been achieved.
Patent Information
- Application Number
- CN202520157932.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-23
- Publication Date
- 2025-11-21
- Estimated Expiration
- 2035-01-23
AI Technical Summary
Existing technologies fail to adequately consider the stress distribution in underground spaces, the interaction between the heavy block storage chamber group and the hoisting shaft, and the disturbance and damage to the surrounding rock caused by underground space excavation. As a result, the underground gravity energy storage well and chamber layout schemes are difficult to maintain long-term safe and stable operation under the conditions of ground stress, surrounding rock excavation disturbance, and cyclic load disturbance of the energy storage heavy blocks.
An underground gravity energy storage well and chamber spatial layout structure was designed, including a vertical well, a group of heavy block storage chambers, a group of heavy block transportation chambers, and connecting chambers. The number, spacing, shape, and size of the chambers were optimized, and a straight-walled semi-circular arched chamber was adopted. The design was optimized by monitoring stress distribution to reduce stress concentration in the surrounding rock.
It has achieved long-term safe and stable maintenance of vertical shafts at a lower cost and with less difficulty, balancing the long-term stability of the chamber with the construction cost, reducing stress concentration in the surrounding rock, and improving energy storage, transportation and storage capacity.
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Figure CN223577988U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to vertical shaft type gravity energy storage technical field, and concretely relates to a kind of underground gravity energy storage shaft and chamber space arrangement structure. BACKGROUND
[0002] Vertical shaft type gravity energy storage system is based on the gravity energy storage of vertical shaft, and the shaft of vertical shaft is a vertical wall straight pipe, so that the height difference of vertical shaft is used as the conveying channel of energy storage weight block, and the weight block is lifted from low place (lower bin) to high place (upper bin) for storage when energy storage, and the electric energy is converted into gravitational potential energy, and the gravitational potential energy is converted into kinetic energy, and then converted into electric energy by generator when discharging. The lower bin is generally located underground, and has a chamber structure for storing and conveying weight blocks, and the chamber is a horizontal tunnel with a large cross section and a short length without a direct surface outlet.
[0003] The gravity energy storage underground chamber is in deep underground space, in a complex mechanical environment of "high ground stress, high ground temperature, high osmotic pressure and strong heavy load transportation disturbance", which leads to significant differences in the mechanical behavior of chamber and roadway surrounding rock, the evolution law of energy and the damage distribution compared with shallow underground space engineering. The supporting means used in shallow underground space engineering is partially or totally invalid in this scenario, increasing the possibility of deformation instability and dynamic disaster of surrounding rock. Moreover, the lower bin of gravity energy storage has a long service life, and conventional supporting means is difficult to cope with the creep and rheological phenomena in long time scale. To meet the service requirements of gravity energy storage, about 30,000 cubic meters of underground rock mass needs to be excavated. The large-scale underground space roof will cause overburden stress concentration, which may cause impact instability and disaster, therefore, the stress concentration of surrounding rock of underground chamber needs to be calculated. In addition, gravity energy storage needs to transport heavy load energy storage blocks periodically in underground space, which will apply cyclic dynamic and static load to the surrounding rock of roadway and chamber. Long-term operation of gravity energy storage unit will cause fatigue damage of surrounding rock of roadway and chamber, and further lead to damage, crack field development and expansion and instability disaster of surrounding rock. Therefore, it is of great significance to study the damage and instability disaster law of surrounding rock under dynamic and static load disturbance conditions of deep gravity energy storage lower bin, and to optimize the design of supporting means according to actual engineering requirements, to ensure the long-term safe and stable operation of gravity energy storage unit.
[0004] In recent years, the number of published data and literature shows that the layout of energy storage underground facilities and related fields are becoming a research hotspot of domestic and foreign scientific research institutions and related enterprises. The current mainstream research on energy storage underground facilities includes underground compressed air energy storage and gravity energy storage.
[0005] For example, patent CN116992529A relates to a hard rock underground compressed air energy storage cavern group layout design method, including the following steps: obtaining the engineering geological parameters of the cavern field area; comprehensively considering the maximum air internal pressure, combining with the engineering geological parameters to determine the safe buried depth; selecting multiple feasible cavern diameters within the range of the maximum cavern diameter allowed by the safe buried depth, establishing a three-cavern model to solve the minimum safe cavern distance; using a quadratic polynomial to fit the relationship between the cavern diameter and the minimum safe cavern distance; determining the cavern group outside reserved distance, the number of caverns permitted by the land use, and the gas storage volume according to the minimum safe cavern distance and the cavern diameter; taking the maximum gas storage volume as the criterion to determine the corresponding minimum safe cavern distance, cavern diameter, number of caverns, and outside reserved distance, and combining the safe buried depth to obtain the cavern group layout design scheme. However, this method does not consider the influence of the layout mode of the connecting caverns and shafts between the storage caverns on the stability of the cavern group. Under the complex operating conditions of the underground energy storage cavern, the surrounding rock of the connecting caverns and shafts may be unstable, affecting the safe and stable operation of the energy storage system.
[0006] For another example, patent CN118167346A proposes a gravity energy storage underground space layout system and a gravity energy storage system. The gravity energy storage underground space layout system includes a logistics shaft, a service shaft, a storage roadway, and a lifting mechanism. The logistics shaft is used for transporting energy storage weights; the logistics shaft and the service shaft are arranged apart and extend in the upward and downward directions; the storage roadway is used for storing the energy storage weights; the storage roadway extends in the lateral direction and intersects each of the logistics shaft and the service shaft, and the logistics shaft, the storage roadway, and the service shaft are sequentially connected to form a ventilation channel; and the lifting mechanism is installed in the logistics shaft to transport the energy storage weights. This layout mode arranges the energy storage caverns and the shafts in the same vertical plane, does not fully utilize the underground space, and may cause stress superposition of different horizontal caverns and shafts, resulting in stress concentration and affecting the long-term safe and stable operation of the underground energy storage cavern. Utility model content
[0007] The technical problem to be solved by the utility model is to provide an underground gravity energy storage shaft and cavern space layout structure, solve the problem that the prior art does not fully consider the stress distribution of the underground space, the interaction between the heavy block storage cavern group and the lifting shaft, and the disturbance and damage effect of the underground space excavation on the surrounding rock, and further solve the problem that the provided underground gravity energy storage shaft and cavern layout scheme is difficult to maintain long-term safe and stable operation under the conditions of the ground stress, the surrounding rock excavation disturbance, and the cyclic load disturbance of the energy storage heavy block, and realize the effect of better balancing the long-term stability of the cavern and the construction cost through further optimization and improvement of the cavern design.
[0008] The utility model discloses a kind of underground gravity energy storage wellbore and chamber space arrangement structure, comprising: vertical wellbore, for transporting energy storage weight between ground and underground chamber;Weight block storage chamber group, for storing energy storage weight;Weight block storage chamber group is arranged on the two sides of vertical wellbore with vertical wellbore as symmetry axis, and the weight block storage chamber group of each side includes five weight block storage chambers arranged in parallel;Weight block transport chamber group, for transporting weight block between each weight block storage chamber;Weight block transport chamber group includes four weight block transport chambers in parallel, and weight block transport chamber is perpendicular to weight block storage chamber;The head end and tail end of weight block transport chamber group on each side of vertical wellbore are connected with a weight block transport chamber;Connecting section chamber, for connecting weight block transport chamber close to vertical wellbore side and vertical wellbore.
[0009] Further, weight block storage chamber group, weight block transport chamber group and connecting section chamber are located at the same depth level, and the whole is symmetrically distributed with vertical wellbore as center.
[0010] Further, the shape of weight block storage chamber is straight wall semicircular arch, and the bottom of weight block storage chamber is provided with two columns of storage racks transversely arranged in parallel, each column of storage racks is formed with carrying channel for carrying vehicle to pass through, and each column of storage racks is formed with storage position capable of placing a column of weight blocks.
[0011] Further, the shape of weight block storage chamber is straight wall semicircular arch, and the ratio of straight wall height and semicircular arch radius is in the range of 0.730-1.807;The distance between each weight block storage chamber is not less than 1.5 times of the width of weight block storage chamber.
[0012] Further, the shape of weight block transport chamber is straight wall semicircular arch, and the right angle connection between each weight block transport chamber and weight block storage chamber is provided with chamfer.
[0013] Further, connecting section chamber is perpendicular to vertical wellbore and weight block transport chamber, and connecting section chamber connects the midpoint of weight block transport chamber with the bottom of vertical wellbore.
[0014] Further, the shape of connecting section chamber is straight wall semicircular arch, and the length of two connecting section chambers on the two sides of vertical wellbore is not less than 17.5m.
[0015] According to the technical scheme of the utility model, the utility model further provides a design method of underground gravity energy storage shaft and chamber space arrangement structure, adopts the underground gravity energy storage shaft and chamber space arrangement structure, wherein the heavy block storage chamber, the heavy block transportation chamber and the connecting section chamber are all straight wall semicircular arch chambers, the design method of the underground gravity energy storage shaft and chamber space arrangement structure includes chamber shape optimization design, and specifically includes the following contents:
[0016] With the semicircular arch radius r as the independent variable, under the condition that the straight wall semicircular arch chamber cross section area is constant, several working conditions are designed; at least four measuring points are arranged on the wall surface of the straight wall semicircular arch chamber, the measuring point positions include the middle position of the top of the straight wall semicircular arch, the middle position of the bottom of the straight wall semicircular arch, the corner position of the bottom of the straight wall semicircular arch, the intersection position between the straight wall and the semicircular arch; the stress conditions in the horizontal and vertical directions of each measuring point under various working conditions are monitored; based on the monitoring results, the change conditions of the horizontal normal stress of each measuring point with the semicircular arch radius r and the change conditions of the vertical normal stress of each measuring point with the semicircular arch radius r are analyzed, the second derivative mean of the horizontal normal stress which first increases and then decreases is selected as the first range R1, and the second derivative mean of the vertical normal stress which first increases and then decreases is selected as the second range R2, the intersection of the first range R1 and the second range R2 is taken as the preferred design range; the ratio of the straight wall height to the semicircular arch radius of each working condition in the preferred design range is calculated, and the preferred straight wall height to semicircular arch radius ratio range is obtained; the preferred straight wall height to semicircular arch radius ratio range is taken as the standard for the design of the straight wall semicircular arch chamber shape.
[0017] Compared with the prior art, the utility model has the beneficial technical effects as follows:
[0018] 1、The underground gravity energy storage shaft and chamber space arrangement structure has the heavy block storage chamber group, the heavy block transportation chamber group and the connecting section chamber, and the number, spacing, shape and size of the chambers are optimized, so that the gravity energy storage and transportation capacity requirements can be met while the difficulty and cost of chamber excavation construction and maintenance are reduced.
[0019] 2、The underground gravity energy storage shaft and chamber space arrangement structure arranges the vertical shaft in the stress reduction zone formed by the excavation of the heavy block storage chambers and the heavy block transportation chambers on both sides, which is beneficial to the long-term safety and stability of the vertical shaft.
[0020] 3、The underground gravity energy storage shaft and chamber space arrangement structure considers the stress distribution of the heavy block storage chamber surrounding rock and the excavation space size, so that the chamber arrangement scheme can better balance the long-term stability and construction cost of the chambers.
[0021] 4. The underground gravity energy storage shaft and chamber space arrangement structure design method of the utility model fully considers the stress distribution change caused by the underground gravity energy storage shaft and chamber excavation, reduces the stress concentration degree in the surrounding rock as much as possible, thereby reducing the difficulty of the underground gravity energy storage shaft and chamber excavation and maintenance. BRIEF DESCRIPTION OF DRAWINGS
[0022] Figure 1 It is a three-dimensional schematic view of the underground gravity energy storage shaft and chamber space arrangement structure provided by the utility model.
[0023] Figure 2 It is a top view schematic view of the underground gravity energy storage shaft and chamber space arrangement structure provided by the utility model.
[0024] Figure 3a It is a structural schematic view of the heavy block storage chamber provided by the utility model.
[0025] Figure 3b It is Figure 3a a preferred design size annotation diagram.
[0026] Figure 4 It is a relationship curve diagram of the semicircular arch radius r and the straight wall height h of the straight wall semicircular arch chamber under the same cross-sectional area.
[0027] Figure 5a It is a horizontal direction displacement detection result diagram of each measuring point under different working conditions in the design method provided by the utility model.
[0028] Figure 5b It is a vertical direction displacement detection result diagram of each measuring point under different working conditions in the design method provided by the utility model.
[0029] Figure 5c It is a horizontal direction normal stress detection result diagram of each measuring point under different working conditions in the design method provided by the utility model.
[0030] Figure 5d It is a vertical direction normal stress detection result diagram of each measuring point under different working conditions in the design method provided by the utility model.
[0031] Figure 5e It is a shear stress detection result diagram of each measuring point under different working conditions in the design method provided by the utility model.
[0032] Figure 5f It is a measuring point arrangement position diagram on the straight wall semicircular arch chamber in the design method provided by the utility model.
[0033] Figure 6 It is a second-order derivative mean value change curve diagram of the horizontal and vertical direction normal stress of each measuring point of the chamber with the semicircular arch radius of the chamber.
[0034] Figures 7a to 7c are vertical stress nephograms when the number of heavy block storage chambers is 3, 5 and 7 respectively.
[0035] Figure 8a Figure 8b are vertical stress nephograms when the length of the connecting section chamber is increased by 20m and 30m respectively. Figure 7b
[0036] Figures 9a to 9d are plastic zone distribution diagrams when the length of the connecting section chamber is increased by 0m, 10m, 20m and 30m respectively.
[0037] Figure 10 is a stress rising area diagram of the heavy block storage chambers on both sides.
[0038] Figure 11 is a stress distribution diagram on the ore pillar under different lengths of the connecting section chamber.
[0039] Explanation of reference signs in the drawings:
[0040] 1, vertical shaft; 2, heavy block storage chamber; 3, heavy block transportation chamber; 4, connecting section chamber; 21, storage rack; 22, carrying vehicle; 23, heavy block; 31, mother vehicle; 32, transfer vehicle; 41, conveyor. DETAILED DESCRIPTION
[0041] The utility model provides a kind of underground gravity energy storage shaft and chamber space arrangement structure, solve the problem that prior art fails to fully consider underground space stress distribution, interaction between heavy block storage chamber group and lifting shaft and the disturbance and damage effect of underground space excavation to surrounding rock, and then the underground gravity energy storage shaft and chamber arrangement scheme provided by the utility model can be maintained long-term safe and stable operation under the condition of ground stress, surrounding rock excavation disturbance and energy storage heavy block cyclic load disturbance.The chamber design of the present scheme is further optimized and improved, and the chamber arrangement spacing proposed considers the surrounding rock stress distribution condition and excavation space size of each heavy storage chamber, so that the long-term stability of the chamber and the construction cost can be better balanced.
[0042] Please refer to Figures 1 to 3a , a kind of underground gravity energy storage shaft and chamber space arrangement structure of the utility model one embodiment, it mainly includes following component parts.
[0043] Vertical shaft 1 is used to transport energy storage heavy (heavy block) between ground (upper warehouse) and underground chamber (lower warehouse), which has lifting system for lifting heavy block and connected power system, so as to realize the basic function of gravity energy storage power generation, and relevant content is prior art, which will not be described here.
[0044] The heavy block storage chamber group is used for storing (and transporting) the energy storage heavy blocks. The heavy block storage chamber group is arranged on both sides of the vertical shaft 1 (generally the horizontal direction, for example, left and right sides in the figure) with the vertical shaft 1 as the symmetry axis, and each side of the heavy block storage chamber group includes five parallel heavy block storage chambers 2. Such layout and quantity are the preferred scheme obtained through design research, which will be further described below.
[0045] The heavy block transportation chamber group is used for transporting the heavy blocks at the position between each heavy block storage chamber 2 (more specifically, outside the end of each heavy block storage chamber 2 in the direction perpendicular to the length of the heavy block storage chamber 2). The heavy block transportation chamber group includes four parallel heavy block transportation chambers 3, which are perpendicular to the heavy block storage chamber 2, and each side of the heavy block transportation chamber group of the vertical shaft 1 is connected with a heavy block transportation chamber 3 at the head and tail.
[0046] The connecting section chamber 4 is used for connecting the heavy block transportation chamber near the side of the vertical shaft 1 with the vertical shaft 1, and the connecting section chamber 4 has a transportation mechanism such as a conveyor for transporting the heavy blocks, so as to realize the transportation of the heavy blocks between the vertical shaft 1 and the heavy block storage chamber 2. The connecting section chamber 4 is two sections located on both sides of the vertical shaft 1, which can be selected as a straight channel, and the vertical shaft 1 is located in the middle of the length direction.
[0047] More specifically, please refer to Figure 3aThe heavy block storage chamber 2 is shaped as a straight wall semi-circular arch, has better mechanical properties and can be applied to the heavy block with high height of the vertical shaft type gravity energy storage system. The bottom of the heavy block storage chamber 2 is provided with two transversely arranged storage racks 21, for example, each of the storage racks 21 includes two support bodies, and the two storage racks 21 share one support body; each of the storage racks 21 (between the two support bodies) is formed with a carrying channel for the carrying vehicle 22 to pass through, and each of the storage racks 21 is formed with a storage position capable of placing one column of heavy blocks 23, for example, the heavy blocks 23 are placed on the two support bodies, and the carrying vehicle 22 is located below the heavy blocks 23. The carrying vehicle 22 is, for example, an RGV trolley, and the carrying channel is correspondingly provided with a track for the carrying vehicle 22 to run. The carrying vehicle 22 is provided with a lifting and conveying device above, so as to lift the heavy blocks 23, move away from the storage rack 21, and then move the heavy blocks 23 to the storage rack 21 and place the heavy blocks 23 on the storage rack 21. The working mode of the carrying vehicle and the heavy block is the prior art, and the main optimization of the present scheme is to select the shape and size of the chamber, and then design the scheme of arranging two storage racks 21 in one heavy block storage chamber 2, which can place two columns of heavy blocks 23. The present scheme can improve the space utilization and the number of heavy blocks, that is, the capacity of energy storage and power generation, while ensuring the long-term stability of the chamber structure, and placing more heavy blocks in one chamber can also help to reduce the construction cost of the chamber.
[0048] For each of the structures on both sides of the vertical shaft 1, the heavy block transportation chamber group has one heavy block transportation chamber 3 connecting one end of all the heavy block storage chambers 2, referred to as the head end, on one side close to the vertical shaft 1, which is used to further move the heavy blocks transported in the heavy block storage chambers 2 to the head end to the connecting section chamber 4, which has one or more mother vehicles 31, such as RGV trolleys similar in structure to the carrier vehicles 22, and is provided with a corresponding track, the mother vehicle 31 can move to the head end of any heavy block transportation chamber 3 to perform the heavy block transfer work with the carrier vehicle 22 in the heavy block transportation chamber 3, and the mother vehicle 31 can also move to the connecting section chamber 4 to perform the heavy block transfer work with the conveyor 41 therein, which is used to realize the heavy block transfer work with the lifting container in the vertical shaft 1. The heavy block transportation chamber group on the side away from the vertical shaft 1 also has another heavy block transportation chamber 3 connecting the other end of all the heavy block storage chambers 2, referred to as the tail end, and the other heavy block transportation chamber 3 has one or more transfer vehicles 32, such as RGV trolleys similar in structure to the carrier vehicles 22, and is provided with a corresponding track, the transfer vehicle 32 can move to the tail end of any heavy block transportation chamber 3, and then the carrier vehicle 22 can move above the transfer vehicle 32, which carries the carrier vehicle 22 to the tail end of the other heavy block transportation chamber 3 (carrier passage), thereby realizing the work of transporting the carrier vehicle 22 between the heavy block storage chambers 2 (carrier passages). By using this scheme, it is not necessary to provide one carrier vehicle 22 in each carrier passage, which can avoid the idle of the carrier vehicle 22, improve the equipment utilization rate, and reduce the construction cost.
[0049] Preferably, the heavy block storage chamber group, the heavy block transportation chamber group, and the connecting section chamber 4 are located at the same depth level and are symmetrically distributed around the vertical shaft 1. This scheme arranges the shaft in the stress reduction zone formed by the excavation of the heavy block storage chambers and the heavy block transportation chambers on both sides, which is beneficial to the long-term safety and stability of the vertical shaft.
[0050] The connecting section chamber 4 is perpendicular to the vertical shaft 1 and the heavy block transportation chamber 3, and connects the midpoint of the heavy block transportation chamber 3 and the bottom of the vertical shaft 1. This structure is more regular, which is convenient for the construction of the chamber and the automatic transportation of heavy blocks during energy storage and power generation.
[0051] The shape of the heavy block transportation chamber 3 is also preferably a straight wall semi-circular arch, and the straight angle connection between each heavy block transportation chamber 3 and the heavy block storage chamber 2 is provided with a chamfer. This structure can avoid excessive local stress and also contribute to the long-term stability of the underground chamber.
[0052] The shape of the connecting section chamber 4 is also preferably straight wall semi-circular arch, and the length of the two connecting section chambers 4 on both sides of the vertical shaft 1 is not less than 17.5m. The shape of the heavy block storage chamber 2 is straight wall semi-circular arch, wherein the ratio of the straight wall height to the semi-circular arch radius is in the range of 0.730-1.807; the distance between each heavy block storage chamber 2 is not less than 1.5 times the width of the heavy block storage chamber 2. Such size is the preferred scheme obtained through design research, which will be further described below.
[0053] Based on the underground gravity energy storage shaft and chamber space arrangement structure, the utility model provides a kind of design method of underground gravity energy storage shaft and chamber space arrangement structure, wherein heavy block storage chamber, heavy block transportation chamber, connecting section chamber are all straight wall semi-circular arch chamber;The design method of underground gravity energy storage shaft and chamber space arrangement structure of the utility model includes chamber shape optimization design, and specifically includes the following contents.
[0054] The cross-sectional area of straight wall semi-circular arch chamber is determined by semi-circular arch radius r and straight wall height h, and when the cross-sectional area is constant, the relationship between them is, for example Figure 4 As shown in the figure.
[0055] Taking semi-circular arch radius r as the independent variable, under the condition that the cross-sectional area of straight wall semi-circular arch chamber is constant, several working conditions are designed, for example, six working conditions shown in the following table are designed.
[0056] Table 1 Chamber cross-sectional shape working condition
[0057]
[0058] As Figure 5f shown, at least four measuring points (four measuring points in this embodiment) are arranged on the wall surface of the straight wall semi-circular arch chamber, and the measuring point positions include the top middle position (P1) of the straight wall semi-circular arch, the bottom middle position (P4) of the straight wall semi-circular arch, the bottom corner position (P3) of the straight wall semi-circular arch and the intersection position (P2) between the straight wall and the semi-circular arch; The stress conditions in horizontal and vertical directions and the displacement change conditions of each measuring point under various working conditions are monitored, and the results are shown in Figures 5a to 5e .
[0059] As Figure 5a can be seen from the monitoring results of each point, the horizontal displacement of measuring point P2 is the largest, followed by measuring point P3. Measuring points P1 and P4 do not produce horizontal displacement because they are on the chamber axis. With the increase of chamber width (i.e. semi-circular arch radius r, i.e. chamber span) and the decrease of height, the horizontal displacement of measuring points P2 and P3 gradually decreases. This shows that under the condition that the chamber cross-sectional area is constant, reducing the straight wall height of the chamber is beneficial to maintaining the stability of the two side rocks.
[0060] AsFigure 5b It can be seen that with the increase of chamber width and the decrease of height, the vertical displacement of measuring point P3 has a decreasing process, and the displacement (absolute value) of the other three measuring points P1, P2 and P4 all increases. This shows that increasing the chamber span will make the vertical stability of the chamber surrounding rock decrease. For measuring point P1, it gradually moves downward; for measuring point P4, it gradually moves upward; that is, the roof deformation and floor heave phenomenon occurs.
[0061] From the above monitoring results, it can be seen that with the increase of chamber width and the decrease of height, the absolute value of the horizontal normal stress of each measuring point decreases to different degrees. The change of measuring point P2 is not significant, and the change degree of measuring points P1 and P4 is basically the same. Measuring point P3 has a significant decrease when the radius of the semicircular arch of the chamber increases from 6m to 7m. Figure 5c From the above monitoring results, it can be seen that with the increase of chamber width and the decrease of height, the absolute value of the horizontal normal stress of each measuring point decreases to different degrees. The change of measuring point P2 is not significant, and the change degree of measuring points P1 and P4 is basically the same. Measuring point P3 has a significant decrease when the radius of the semicircular arch of the chamber increases from 6m to 7m.
[0062] Figure 5d From the above monitoring results, it can be seen that with the increase of chamber width and the decrease of height, the absolute value of the horizontal normal stress of each measuring point decreases to different degrees. The change of measuring point P2 is not significant, and the change degree of measuring points P1 and P4 is basically the same. Measuring point P3 has a significant decrease when the radius of the semicircular arch of the chamber increases from 6m to 7m.
[0063] From the above monitoring results, it can be seen that with the increase of chamber width and the decrease of height, the absolute value of the horizontal normal stress of each measuring point decreases to different degrees. The change of measuring point P2 is not significant, and the change degree of measuring points P1 and P4 is basically the same. Measuring point P3 has a significant decrease when the radius of the semicircular arch of the chamber increases from 6m to 7m. Figure 5e From the above monitoring results, it can be seen that with the increase of chamber width and the decrease of height, the absolute value of the horizontal normal stress of each measuring point decreases to different degrees. The change of measuring point P2 is not significant, and the change degree of measuring points P1 and P4 is basically the same. Measuring point P3 has a significant decrease when the radius of the semicircular arch of the chamber increases from 6m to 7m.
[0064] Figure 6 Based on the above monitoring results, the change of the horizontal normal stress of each measuring point with the radius r of the semicircular arch and the change of the vertical normal stress of each measuring point with the radius r of the semicircular arch are analyzed, the second-order derivative mean of the horizontal normal stress is selected as the first range R1, and the second-order derivative mean of the vertical normal stress is selected as the second range R2, and the intersection (light background interval) of the first range R1 and the second range R2 is selected as the preferred design range. For this embodiment, the displacement and stress of each measuring point in the horizontal and vertical directions under the conditions of working conditions 2 to 4 are more balanced, which is more conducive to the stability of the chamber surrounding rock. Figure 6
[0065] The mean second derivative of the stress at the measuring points in the surrounding rock reflects the acceleration change of the surrounding rock under load in the horizontal or vertical direction. A stage characterized by an initial increase followed by a decrease in the mean second derivative of stress indicates that the rate of load increase on the surrounding rock is gradually slowing down, suggesting that the surrounding rock is transitioning from a stable bearing state to an unstable failure state. Further analysis shows that when both the mean second derivatives of the vertical and horizontal normal stresses exhibit an initial increase followed by a decrease, the intersection of their corresponding time periods (or intervals) represents the critical point of the horizontal and vertical stability of the surrounding rock in the chamber. Within this critical point, the surrounding rock has a high bearing capacity in both the horizontal and vertical directions and can effectively resist significant damage. Once this range is exceeded, the stability of the surrounding rock will decrease significantly, and unstable failure may occur.
[0066] Furthermore, the ratio of the straight wall height to the semi-circular arch radius for each working condition within the preferred design range is calculated, yielding a preferred range for this ratio. In this embodiment, this range is 0.730 to 1.807, thus providing a more universally applicable result. Using this preferred range for the ratio of the straight wall height to the semi-circular arch radius as a standard for the reasonable design of a straight-walled arched chamber allows for the design or verification of the chamber.
[0067] Specifically, the shape and dimensions of a chamber are as follows: Figure 3b As shown (in mm), the ratio of the height of the straight wall to the radius of the semicircular arch is 1.667, which is within the reasonable standard range obtained from the simulation.
[0068] Preferably, the design method also includes numerical simulation studies on the effect of chamber spacing on the stability of the surrounding rock, as detailed below.
[0069] The numerical model was built based on a tunnel span of 12m and a tunnel height of 12.8m. Excavation was considered under the most unfavorable scenario, i.e., the tunnel was excavated in one go. To eliminate boundary effects, the model extends 30m to the left and right, with dimensions of 144m (X-direction) length, 80m (Y-direction) width, and 40m (Z-direction) height. The established model has 363,531 nodes and 344,000 elements.
[0070] According to relevant specifications, the net distance between adjacent caverns should ideally be 1 to 2 times the width of the cavern. However, in actual engineering design, the cavern spacing should be determined comprehensively by combining domestic and international experience and numerical analysis methods. In some foreign regions, the span-to-cavity ratio of existing underground caverns is 2.0 to 2.3. In some domestic regions, the span-to-cavity ratio of existing underground caverns is 1.5 to 2.0. Therefore, this simulation selected six working conditions (as shown in the table below) to simulate the interaction effects and stability of multiple adjacent caverns, proposing a more reasonable range for cavern spacing.
[0071] Table 2 Simulation Calculation Conditions for Cavern Spacing
[0072]
[0073] The plastic zone development and the maximum principal stress distribution of each chamber under different chamber spacing are obtained by simulation.
[0074] The simulation results show that, with the increase of chamber spacing, the mutual disturbance between adjacent chambers gradually decreases. The larger the chamber spacing, the smaller the plastic zone area formed near each chamber. The change of the plastic zone area on the left and right sides of the chamber is more sensitive to the change of the chamber spacing than the change of the plastic zone area in the upper and lower directions. The degree of decrease of the plastic zone area on both sides of the chamber decreases gradually with the increase of the distance. When the chamber span ratio is greater than 2, the plastic zone area near the chamber hardly changes with the further increase or decrease of the chamber spacing. At this time, increasing the chamber spacing cannot continue to play a significant role in maintaining the stability of the chamber surrounding rock.
[0075] Therefore, under the premise of ensuring the stability of the chamber surrounding rock, the most economical chamber spacing is 2 times the chamber span ratio, that is, the distance between adjacent heavy block storage chambers 2 is 2 times the width of the heavy block storage chamber 2. Due to the actual engineering needs, there is a certain consideration for flexible adjustment of the design size, and it is limited that the distance between adjacent heavy block storage chambers 2 is not less than 1.5 times the width of the heavy block storage chamber 2. For example, the design to be adopted is that the chamber width is 7.5 m and the chamber spacing is 15 m, which meets the most stable chamber spacing design.
[0076] Preferably, the design method further comprises optimization research on the arrangement of the energy storage chamber and the shaft, which is specifically as follows.
[0077] Firstly, for the overall stress field distribution law under different chamber numbers (the number of heavy block storage chamber 2 in the heavy block storage chamber group on each side), the overall system vertical stress field cloud chart under different chamber numbers is analyzed. As shown in Figures 7a to 7c Generally speaking, the number of chambers has little effect on the distribution law of the overall vertical stress. A certain high stress is generated around the shaft due to the influence of the chamber. With the increase of the number of chambers, the stress size of the high stress area continuously increases. The highest stress when the number of chambers is 7 is about 5 MPa higher than that when the number of chambers is 3, and the highest stress when the number of chambers is 5 is only 2 MPa higher. High stress also accumulates on the rock pillars between the chambers, mainly concentrated in the first 10 m position of the chamber. The stress on the rock pillars between the chambers in the middle position is greater than that on the rock pillars between the chambers on both sides. With the increase of the number of chambers, the high stress accumulated on the rock pillars between the chambers also increases.
[0078] Therefore, considering the stability of the whole system, the stress between the shaft and the chamber is the lowest when the number of chambers is 3, and the stability is better. However, when the number of chambers is 5, the overall stress changes little, and the transportation efficiency is greatly improved. Therefore, the number of chambers is 5, which is more reasonable. In addition, since a larger stress concentration will be generated when the intersection of the chambers is a right angle, it is recommended to adjust the right angle at the intersection of the chambers to a rounded corner.
[0079] On the other hand, for the overall stress field distribution law under different lengths of the connecting section of the shaft and the lower bin (i.e., the length of the connecting section chamber 4), the vertical stress nephogram around the shaft under different lengths of the connecting section is analyzed, as shown in Figure 7b , Figure 8a , Figure 8b The reference condition is shown in Figure 7b , and the length of the connecting section on each side is 7.5 m. It can be seen that as the length of the connecting section increases, the high stress concentration around the shaft gradually weakens. Compared with the initial design scheme with a shorter length of the connecting section chamber 4, the maximum stress around the shaft is about 55 MPa after the connecting section is increased by 10 m, which decreases by about 10 MPa. When the length of the connecting section is increased by 20 m and 30 m, the stress concentration around the shaft can be more effectively relieved, but the effect is limited compared with the case where the length of the connecting section is increased by 10 m. Accordingly, when the length of the connecting section is increased by 10 m, i.e., the length of the connecting section on each side is 17.5 m, the stress concentration of the chamber surrounding rock is significantly relieved. Therefore, the length of the connecting section chamber should be greater than 17.5 m to avoid stress concentration in the chamber surrounding rock, which may lead to instability and damage of the surrounding rock.
[0080] In addition, the overall plastic zone distribution of the transportation system under different lengths of the connecting section is analyzed, as shown in Figures 9a to 9d , Figure 10 The reference condition is shown in Figure 9a , and the length of the connecting section on each side is 7.5 m. It can be seen that as the length of the connecting section increases, the range of the plastic zone in the surrounding rock around the shaft decreases. This is because the stress concentration area gradually moves away from the shaft as the length of the connecting section increases, which improves the stability of the surrounding rock. However, as the length of the connecting section increases, the plastic zone between the heavy block storage chambers increases. This is because the system as a whole can be divided into two parts with the shaft as the center, and the mutual influence between the two parts is similar to the stress concentration caused by mining. When the length of the connecting section is increased by 20 m and 30 m, the position of the chamber will be most affected by the other part, which will cause the plastic zone to increase. Overall, the range of the plastic zone is lower when the length of the connecting section is increased by 10 m compared with 20 m and 30 m.
[0081] Then the stress situation is analyzed, and the results show that different lengths of the connecting section have little effect on the vertical stress distribution around the chamber roadway. In addition, the stress variation in the surrounding rock under different lengths of the connecting section is analyzed, as shown in Figure 11As shown, it can be seen that the force on the pillar between the chambers presents a saddle-shaped distribution, and with the increase of the length of the connecting section, the force on the pillar presents a downward trend, and the speed of the decrease is the fastest in the interval from the increase of 0m to the increase of 10m of the connecting section.
[0082] In summary, in view of the three points of the stress distribution size, the plastic zone width and the stress distribution on the pillar, it is a more reasonable choice to increase the length of the connecting section chamber by 10m, that is, the length of the two connecting section chambers 4 on both sides of the vertical shaft 1 is not less than 17.5m.
[0083] As a supplement, since the overall chamber arrangement is symmetrically arranged along the center shaft, it is described that the length of the connecting section on both sides is not less than 17.5m, and the length of the defined connecting section chamber 4 does not include the shaft part. When the length of the connecting section chamber 4 is 17.5m, the total length of the two connecting section chambers including the shaft part (that is, the interval between the two weight block transportation chambers 3 on both sides of the shaft) is actually (unit: m), wherein R is the radius of the shaft, and w is the width of the connecting section chamber 4.
[0084] In addition, it also includes the stability analysis of the chamber roadway under static load, which specifically includes the following contents.
[0085] On the basis of determining the number of chambers and the length of the connecting section, the vertical stress of 0.16MPa is added to the model bottom plate to simulate the full load weight block working condition. By comparing the vertical stress cloud difference after applying the static load, it can be found that the stress added by the weight of the weight block is far less than the stress state of the environment where the chamber is located, so the influence on the stress distribution around the chamber is small, and from the perspective of the plastic zone, the width of the overall plastic zone changes little, indicating that the application of static load has little effect on the stability of the chamber of the spatial arrangement structure of the utility model.
[0086] In summary, the underground gravity energy storage shaft and chamber space arrangement structure of the utility model has the design of heavy block storage chamber group, heavy block transportation chamber group and connecting section chamber, and optimizes the design of the number, spacing, shape, size and the like of the chamber, can reduce the difficulty and cost of chamber excavation construction and maintenance while better meeting the gravity energy storage transportation and storage capacity requirements; the utility model arranges the vertical shaft in the stress reduction area formed by the excavation of the heavy block storage chamber and the heavy block transportation chamber on both sides, which is beneficial to maintaining the long-term safety and stability of the vertical shaft; the chamber arrangement spacing of the utility model considers the stress distribution of the surrounding rock of each heavy block storage chamber and the excavation space size, so that the chamber arrangement scheme of the utility model can better balance the long-term stability of the chamber and the construction cost; the design method of the utility model fully considers the stress distribution change caused by the excavation of the underground gravity energy storage shaft and chamber, and reduces the stress concentration degree in the surrounding rock as much as possible, thereby reducing the difficulty of the excavation and maintenance of the underground gravity energy storage shaft and chamber.
[0087] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the utility model, but not to limit them; obviously, the described examples are part of the embodiments of the utility model, but not all. Based on the examples in the utility model, all other examples obtained by those skilled in the art without creative labor, such as only modifying the chamber burial depth, adjusting the chamber size and shape and the like, without great modification of the shaft and chamber arrangement, belong to the protection scope of the utility model; for the convenience of description, only the part related to the utility model is shown in the drawings. In the case of no conflict, the examples in the utility model and the features in the examples can be combined with each other; modifying the technical solutions recorded in the foregoing examples, or making equivalent replacement to part of the technical features, does not make the essence of the corresponding technical solution deviate from the spirit and scope of the technical solutions of the embodiments of the utility model.
Claims
1. A spatial arrangement structure for an underground gravity energy storage wellbore and chamber, characterized in that, include: A vertical shaft (1) is used to transport energy-storing heavy objects between the ground and the underground chamber; The heavy block storage chamber group is used to store energy storage heavy objects; the heavy block storage chamber group is arranged on both sides of the vertical shaft (1) with the vertical shaft (1) as the axis of symmetry, and each side of the heavy block storage chamber group includes five heavy block storage chambers (2) arranged in parallel. A group of heavy block transport chambers is used to transport heavy blocks between the heavy block storage chambers (2); the group of heavy block transport chambers includes four parallel heavy block transport chambers (3), which are perpendicular to the heavy block storage chambers (2); a heavy block transport chamber (3) is connected to the first and last ends of the group of heavy block transport chambers on each side of the vertical shaft (1); Connecting section chamber (4), which is used to connect the heavy block transport chamber near the vertical shaft (1) to the vertical shaft (1).
2. The underground gravity energy storage well shaft and chamber spatial arrangement structure according to claim 1, characterized in that, The heavy block storage chamber group, the heavy block transportation chamber group and the connecting section chamber (4) are all located at the same burial depth level, and are symmetrically distributed around the vertical shaft (1).
3. The underground gravity energy storage well shaft and chamber spatial arrangement structure according to claim 1, characterized in that, The shape of the heavy block storage chamber (2) is a straight wall semi-circular arch. The bottom of the heavy block storage chamber (2) is provided with two horizontally parallel storage racks (21). Each storage rack (21) has a transport channel for the transport vehicle (22) to pass through. Each storage rack (21) has a storage position that can hold a row of heavy blocks (23).
4. The underground gravity energy storage well shaft and chamber spatial arrangement structure according to claim 1, characterized in that, The shape of the heavy block storage chamber (2) is a straight wall semi-circular arch, wherein the ratio of the height of the straight wall to the radius of the semi-circular arch is in the range of 0.730 to 1.807; the distance between each heavy block storage chamber (2) is not less than 1.5 times the width of the heavy block storage chamber (2).
5. The underground gravity energy storage well shaft and chamber spatial arrangement structure according to claim 1, characterized in that, The shape of the heavy block transport chamber (3) is a straight wall semi-circular arch, and the right angle connection between each heavy block transport chamber (3) and the heavy block storage chamber (2) is provided with a chamfer.
6. The underground gravity energy storage well shaft and chamber spatial arrangement structure according to claim 1, characterized in that, The connecting section chamber (4) is perpendicular to the vertical shaft (1) and the heavy block transport chamber (3). The connecting section chamber (4) connects the midpoint of the heavy block transport chamber (3) to the bottom of the vertical shaft (1).
7. The underground gravity energy storage well shaft and chamber spatial arrangement structure according to claim 1, characterized in that, The shape of the connecting section chamber (4) is a straight-walled semi-circular arch, and the length of the two connecting section chambers (4) on both sides of the vertical shaft (1) is not less than 17.5m.