A method for designing spatial arrangement of a multi-layer annular cavern gas storage

Abstract

The application relates to a multi-layer annular cavern gas storage space arrangement design method, which comprises the following steps: selecting an underground storage site and a ground site, and determining the storage depth; designing a hole section lining diameter, a steel lining thickness, a lining thickness and related supporting parameters, and determining the total length required by the cavern; designing a reasonable hole spacing according to rock mass mechanical parameters, so that a safety distance is ensured at the narrowest part of the cavern; determining a cavern space arrangement scheme, forming an upper-middle-lower at least three-layer cavern arrangement structure according to the space arrangement scheme; optimizing the spacing and stress, and forming a staggered position in the length and width directions of each layer of the cavern, so that the spacing between adjacent caverns meets the safety spacing; firstly, the spatial position of the hole section is designed through reasonable spacing, and the length of the annular connection direction is determined; then, the length of each cavern is obtained by subtracting the total length of the three-layer cavern annular connection from the total length; the positions of the inclined shaft and the vertical shaft are arranged and designed; and the caverns are constructed layer by layer from shallow to deep.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric energy storage, in particular to a multi-layer annular cavern gas storage space arrangement design method. BACKGROUND

[0002] Compressed air energy storage has flexible regulation attributes, and is considered to be a storage technology with good application prospects under the background of rapid growth of electric energy storage demand. Underground storage is an important part of compressed air energy storage power stations and a key technology to ensure their operation performance and reliability, which determines the site selection of compressed air energy storage power stations. Common underground storage includes salt caves, aquifers, depleted oil and gas fields, abandoned mine tunnels, and artificial caverns, the first four of which rely on special geological structures and mineral resources, and are limited in site selection. Artificial caverns have less restrictions on geological structures, a wide range of adaptability, and a higher matching degree with new energy resources in China, and are the current compressed air underground storage solution being vigorously promoted.

[0003] Circular tunnels have uniform stress, small cross-section, strong structural bearing capacity, and various tunnel group combination methods, and good maintenance conditions, and are the most widely used form of caverns at present. With the increasing installed capacity of compressed air energy storage power stations year by year, the demand for underground gas storage capacity is also increasing, and the tunnel line of the tunnel type cavern will become very long. If the conventional planar arrangement method is used, the caverns will have a wide area to be laid, and the regional geological requirements will be very high. Therefore, how to reasonably arrange the cavern groups in a limited geological space and reduce the area to be laid is a key problem that needs to be solved in the design of large-scale compressed air artificial caverns. SUMMARY

[0004] The embodiment of the present application provides a multi-layer annular cavern gas storage space arrangement design method, which can reduce the requirements for the range of the site, thereby being better applicable to large-capacity compressed air energy storage power stations. The multi-layer annular cavern gas storage space arrangement design method comprises the following steps:

[0005] 1) Selecting the site of the underground storage and the ground plant area, surveying the site of the underground storage, and determining the burial depth of the storage;

[0006] 2) Designing the liner diameter after the tunnel section, the steel liner thickness, the lining thickness, and the related support parameters according to the target rock mass mechanical parameters and the gas storage pressure;

[0007] 3) Determining the total length required by the cavern according to the cavern liner diameter after the cavern volume requirement and the cavern liner diameter, and designing a reasonable inter-cavern distance according to the rock mass mechanical parameters to ensure a safety distance at the narrowest part of the cavern;

[0008] 4) Determining the spatial arrangement scheme of the cavern, and forming a cavern arrangement structure with at least three layers of upper, middle, and lower caverns according to the spatial arrangement scheme;

[0009] 5) Optimize spacing and stress. Each layer of caverns is staggered in length and width to ensure that the spacing between adjacent caverns meets the safety spacing.

[0010] 6) First, design the spatial position of the cavern section through reasonable spacing and determine the length of the circular connection direction. Then, subtract the total length of the three-layer cavern circular connection from the total length to obtain the average length of each cavern.

[0011] 7) Design the layout of inclined shafts and vertical shafts;

[0012] 8) The cavern is constructed layer by layer from shallow to deep, and the construction sequence is carried out according to the steps of excavation, support, steel lining welding, lining backfill, pipeline installation, and sealing body backfill.

[0013] In addition, the multi-layer annular cavern gas storage space layout design method provided in the embodiment of the present application may also have the following additional technical features:

[0014] In an optional scheme, the cavern arrangement structure on the same layer includes at least two caverns, and at least two caverns on the same layer are connected to form an annular cavern. The right-angle connection of the caverns is cornered and replaced by a quarter arc with a radius of 20 to 30 m. The width of the annular cavern can be optimized according to the site, and the minimum width is a safe distance.

[0015] In an optional solution, in step 5), the staggered distance of each layer of the caverns in the length and width directions is 3 to 4 times the cave diameter;

[0016] In step 6), the total length of the annular connection of the three layers of caverns includes the corner length.

[0017] In an optional solution, the step 1) specifically includes the following steps:

[0018] 1.1) Conduct on-site surveys and collect data on regional geology, lithology, topography, hydrology, and transportation to select underground storage and surface plant sites;

[0019] 1.2) Conduct a site survey for the underground reservoir to reveal information on rock stratum distribution, regional structure, geostress, groundwater, and rock mass mechanical parameters, comprehensively delineate rock mass classification, and select the target rock mass for the compressed air reservoir based on the rock stratum distribution and rock mass classification, and determine the reservoir burial depth within the range of 100 to 200 meters.

[0020] In an optional solution, in step 2), the diameter of the designed cavern section after lining is 8 to 10 m, the thickness of the steel lining is 16 to 30 mm, and the thickness of the lining is 60 to 80 cm;

[0021] In the step 3), the designed hole interval is not less than 5-6 times of the hole diameter.

[0022] In an alternative, the step 7) comprises the following steps:

[0023] A slope shaft is arranged at one end of the gas storage cavern group, and a vertical shaft is arranged at the other end, the diameter of the vertical shaft is 8-12 m, the vertical shaft is ventilated during construction, and is an air inlet and outlet after completion, and is connected to a gas transmission pipeline leading to the ground, at least three layers of the caverns share one vertical shaft, and each layer is connected to the vertical shaft through a connecting channel;

[0024] The three-layer annular caverns are gas storage spaces, the connecting channels of the gas storage caverns to the outside are blocked during operation, and only the gas inlet and outlet pipelines and the maintenance openings are reserved.

[0025] The beneficial effects of the embodiments of the present application are:

[0026] The multi-layer annular cavern gas storage space arrangement design method in the embodiments of the present application aims to reduce the land area occupied by the cavern group, and a circular tunnel is designed as a library space arrangement scheme, the caverns are at least divided into three layers, the caverns in each layer are arranged staggered, the adjacent caverns maintain a reasonable hole interval, there is no plug, the number of plugs is small, the cavern group is stable in stress, the requirements for the site range are greatly reduced, and the multi-layer annular cavern gas storage space arrangement design method can be better applied to large-capacity compressed air energy storage power stations.

[0027] It should be understood that the foregoing general description and the following detailed description are only exemplary and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The multi-layer annular cavern gas storage space arrangement schematic diagram provided by the present application is shown in the figure;

[0029] Figure 2 The left view schematic diagram of the gas storage cavern space arrangement is shown in the figure; Figure 1 The left view schematic diagram of the gas storage cavern space arrangement is shown in the figure;

[0030] Figure 3 The front view schematic diagram of the gas storage cavern space arrangement is shown in the figure. Figure 1 The front view schematic diagram of the gas storage cavern space arrangement is shown in the figure.

[0031] The figure shows the following signs: vertical shaft 1, slope shaft 2, blocking body 3, uppermost layer of caverns 4, middle layer of caverns 5, and bottom layer of caverns 6.

[0032] The accompanying drawings are incorporated into the specification and form a part of the specification, show embodiments consistent with the present application, and together with the specification serve to explain the principles of the present application. DETAILED DESCRIPTION

[0033] In order to better understand the technical solutions of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0034] It should be noted that the embodiments described are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0035] The terms used in the embodiments of the present application are merely for the purpose of describing the specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0036] It should be understood that the term "and / or" used herein is only to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A existing alone, A and B existing together, and B existing alone. In addition, the character " / " herein generally represents an "or" relationship between the front and rear associated objects.

[0037] It should be noted that the "up", "down", "left", "right" and the like described in the embodiments of the present application are described from the angle shown in the drawings, and should not be understood as a limitation on the embodiments of the present application. In addition, in the context, it should also be understood that when referring to an element connected "on" or "under" another element, it can be directly connected "on" or "under" another element, or indirectly connected "on" or "under" another element through an intermediate element.

[0038] As shown in Figures 1-3 The embodiments of the present application provide a multi-layer annular cavern gas storage space arrangement design method. The design method is based on a circular tunnel, reduces the cavern plane laying area through spatial multi-layer arrangement, forms a ring runway type arrangement with two caverns in the same layer, reduces the head and plugging body, arranges each layer of caverns staggered, forms staggered arrangement in space, and the cavern stability is good. The caverns between layers can be connected with the ground through a gas pipeline, and the arrangement form of one inclined shaft 2 and one vertical shaft 1 can guarantee the functions of transportation, ventilation and later maintenance and gas transmission. The arrangement form maintains the advantages of the circular tunnel, the cavern itself has good stability, and the range of surrounding rock of the arrangement is small, and high-quality surrounding rock can also be fully utilized in space, thereby reducing the land area of the underground cavern and reducing the constraints of regional geological conditions.

[0039] Specifically, the multi-layer annular cavern gas storage space arrangement design method comprises the following steps: 1) selecting the underground storage and the ground plant site, surveying the underground storage site, and determining the storage depth.

[0040] 2) Based on the target rock mass mechanical parameters and gas storage pressure, design the tunnel section lining diameter, steel lining thickness, lining thickness and related support parameters.

[0041] 3) Determine the total length of the cavern required based on the reservoir volume requirement and the diameter of the cavern lining; design a reasonable hole spacing based on the rock mass mechanics parameters to ensure a safe distance at the narrowest point of the cavern.

[0042] 4) Determine the spatial layout of the caverns and form a cavern layout structure with at least three layers, top, middle and bottom, according to the spatial layout plan; Figures 1-3 As shown, taking the three-layer cavern arrangement structure as an example, the three-layer cavern arrangement structure has a total of 8 caverns, among which the bottom layer caverns 6 are 4 caverns, the middle layer caverns 5 are 2 caverns, and the top layer caverns 4 are also 2 caverns. If the three-layer arrangement structure has a total of 6 caverns, the number of caverns in the upper, middle and lower layers is the same.

[0043] 5) In order to avoid large-scale overlap of upper and lower caverns and optimize spacing and stress, each layer of caverns is staggered in length and width so that the spacing between adjacent caverns meets the safety distance.

[0044] 6) The length of the caverns is equal. When designing, first design the spatial position of the cavern section through reasonable spacing, and determine the length in the circular connection direction. Then subtract the total length of the circular connection of the three layers of caverns from the total length to obtain the average length of each cavern.

[0045] 7) Design the layout of the inclined shaft 2 and the vertical shaft 1.

[0046] 8) The cavern is constructed layer by layer from shallow to deep, and the construction sequence is carried out according to the steps of excavation, support, steel lining welding, lining backfill, pipeline installation, and sealing body backfill.

[0047] like Figures 1-3 As shown, in a specific embodiment, the cavern arrangement structure on the same layer includes at least two caverns, and at least two caverns on the same layer are connected to form an annular cavern, and the right-angle connection of the caverns is cornered and replaced by a quarter arc, and the arc radius is 20 to 30m. The width of the annular cavern can be optimized according to the site, and the minimum width is a safe distance.

[0048] In a specific embodiment, in step 5), the staggered distance of each layer of caverns in the length and width directions is 3 to 4 times the cavern diameter; in step 6), the total length of the annular connection of the three layers of caverns includes the corner length.

[0049] In a specific embodiment, step 1) specifically includes the following steps: 1.1) Conducting on-site surveys and collecting information on regional geology, lithology, topography, hydrology, and transportation to select underground storage and surface plant sites.

[0050] 1.2) Survey the site of the underground storage, reveal the rock distribution, regional structure, ground stress, groundwater and rock mass mechanical parameter information, and comprehensively determine the rock mass classification. According to the rock distribution and rock mass classification, the target rock mass of the compressed air storage is selected, and the storage depth is determined within the range of 100-200 m.

[0051] In a specific embodiment, in step 2), the designed hole section lining diameter is 8-10 m, the steel lining thickness is 16-30 mm, and the lining thickness is 60-80 cm. In step 3), the designed hole spacing is not less than 5-6 times the diameter of the cavern.

[0052] As shown in Figures 1-3 , in a specific embodiment, step 7) includes the following steps: arranging an inclined shaft 2 at one end of the gas storage cavern group and arranging a vertical shaft at the other end. The diameter of the vertical shaft is 8-12 m. The vertical shaft is ventilated during construction and is the gas inlet and outlet after completion. The vertical shaft 1 is connected to the gas pipeline leading to the ground. At least three layers of caverns share one vertical shaft 1, and each layer is connected to the vertical shaft 1 through a connecting channel. In addition, the three layers of annular caverns are gas storage spaces. The connecting channels between the gas storage caverns and the outside are sealed by a sealing body 3 during operation. Only the gas inlet and outlet pipelines and the maintenance opening are reserved.

[0053] As shown in Figures 2-3 , in the cavern arrangement structure of the embodiment of the application, the uppermost layer of caverns 4, the middle layer of caverns 5 and the bottommost layer of caverns 6 are staggered in the length and width directions, so that the spacing between adjacent caverns meets the safety spacing requirement. For example, the hole spacing L1 between the uppermost layer of caverns 4 and the middle layer of caverns 5 is not less than 5-6 times the diameter of the uppermost layer of caverns 4 or the middle layer of caverns 5. In addition, the staggered distance L2 of the middle layer of caverns 5 and the bottommost layer of caverns 6 in the width direction is 3-4 times the hole diameter, and the staggered distance L3 of the middle layer of caverns 5 and the bottommost layer of caverns 6 in the length direction is also 3-4 times the hole diameter. Similarly, the uppermost layer of caverns 4 and the middle layer of caverns 5 also meet the staggered distance requirement, and therefore, the specific description is not given herein.

[0054] Embodiment 1:

[0055] A 600 MW / 2400 MWh compressed air energy storage power station is planned to be built in a certain place. Artificial caverns are used as compressed air storage. The cavern storage capacity is required to be at least 700,000 m 3 . The operating pressure is 0.1-10.5 MPa. The artificial cavern storage is designed.

[0056] The steps are as follows:

[0057] 1) Collect information and conduct site survey, and preliminarily select the site according to the information of topography, outcropped strata and geological structure, etc.

[0058] 2) On-site survey and laboratory test of selected area, obtain ground stress, surrounding rock classification and corresponding mechanical parameters, surrounding rock is granite, at target site, at 50-200m depth, local integrity is better.

[0059] 3) According to the mechanical parameters of granite, design the diameter of the chamber lining is 10m, the thickness of steel lining is 16mm, the thickness of lining is 80cm, the support mainly uses 3m and 4.5m anchor rod, the minimum design of chamber spacing is 60m.

[0060] 4) According to the reservoir capacity of 700000m3 and the section of 10m, the total length of the chamber is about 9km.

[0061] 5) According to the layout scheme of three layers, eight chambers and four annular, design the width of the lowest layer annular chamber is 100m, the spacing between two annular is 60m, the width of the middle layer annular is 160m, the width of the uppermost layer is 80m, the total length in the width direction is 880m, the average length of the chamber is 1015m.

[0062] 6) Considering that there is no direct overlapping section in each layer of chamber, the spacing of each layer is not less than 50m. Here, the first layer is buried at-60m, the middle layer is at-110m, and the lowest layer is at-160m.

[0063] 7) At one end of the gas storage chamber group, there is an inclined shaft 2, which reaches the first layer and spirals down in turn. The other end of the vertical shaft is 12m in diameter, with a construction passage at each layer, which is properly sealed in the later stage.

[0064] 8) The three layers of chambers are constructed from shallow to deep layer by layer, the construction sequence is carried out according to the steps of excavation, support, steel lining welding, lining backfill, pipeline distribution, and sealing body backfilling, and finally forms a multi-layer chamber gas storage.

[0065] The above is only the preferred embodiment of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for designing the spatial layout of a multi-layer annular cavern gas storage, characterized in that: The following steps are involved: 1) Select the site for the underground storage and the surface plant, conduct a site survey for the underground storage, and determine the storage depth; 2) Design the tunnel section lining diameter, steel lining thickness, lining thickness, and related support parameters based on the target rock mass mechanical parameters and gas storage pressure; 3) Determine the total length of the cavern required based on the required storage volume and the diameter of the cavern after lining; design a reasonable hole spacing based on the rock mass mechanics parameters to ensure a safe distance at the narrowest point of the cavern; 4) Determine the spatial layout of the caverns and form a cavern layout structure with at least three layers (upper, middle, and lower) based on the spatial layout plan; 5) Optimize spacing and stress. Each layer of caverns is staggered in length and width to ensure that the spacing between adjacent caverns meets the safety spacing. 6) First, design the spatial position of the cavern sections by reasonable spacing and determine the length of the circular connection direction. Then, subtract the total length of the three-layer cavern circular connection from the total length to obtain the average length of each cavern. 7) Design the layout of inclined shafts and vertical shafts; 8) The caverns are constructed layer by layer from shallow to deep, with the construction sequence being excavation, support, steel lining welding, lining backfill, pipeline installation, and plugging body backfill; The cavern arrangement structure on the same layer includes at least two caverns, and at least two caverns on the same layer are connected to form an annular cavern. The right-angle connection of the caverns is cornered and replaced by a quarter arc with a radius of 20~30m. The width of the annular cavern can be optimized according to the site, and the minimum width is the safety distance.

2. The spatial layout design method of a multi-layer annular cavern gas storage according to claim 1 is characterized in that: In step 5), the staggered distance of each layer of the caverns in the length and width directions is 3 to 4 times the cave diameter; In step 6), the total length of the annular connection of the three layers of caverns includes the corner length.

3. The spatial layout design method of a multi-layer annular cavern gas storage according to any one of claims 1-2, characterized in that: The step 1) specifically includes the following steps: 1.1) Conduct on-site surveys and collect data on regional geology, lithology, topography, hydrology, and transportation to select underground storage and surface plant sites; 1.2) Conduct a site survey for the underground reservoir to reveal information on rock strata distribution, regional structure, geostress, groundwater, and rock mass mechanical parameters. Comprehensively define rock mass classification. Based on the rock strata distribution and rock mass classification, select the target rock mass for the compressed air reservoir and determine the reservoir burial depth within the range of 100-200m.

4. The spatial layout design method of a multi-layer annular cavern gas storage according to claim 3 is characterized in that: In step 2), the diameter of the designed cavern section after lining is 8-10m, the thickness of the steel lining is 16-30mm, and the thickness of the lining is 60-80cm; In step 3), the designed hole spacing is not less than 5 to 6 times the cavity diameter.

5. The spatial layout design method of a multi-layer annular cavern gas storage according to any one of claims 1-2 or claim 4, characterized in that: The step 7) includes the following steps: An inclined shaft is arranged at one end of the gas storage cavern group, and a vertical shaft is arranged at the other end. The diameter of the vertical shaft is 8-12 meters. The vertical shaft is ventilated during construction and serves as an air inlet and outlet after completion, connecting to a gas pipeline leading to the ground. At least three layers of the caverns share one vertical shaft, and each layer is connected to the vertical shaft through a connecting passage. The three-layer annular cavern is the gas storage space. The connection channel between the gas storage cavern and the outside world will be blocked during operation, leaving only the inlet and outlet pipes and inspection ports.

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