Vertical underground high-pressure lining gas storage and construction method

Abstract

The invention provides a vertical underground high-pressure lining gas storage and a construction method. The construction method comprises the following steps: determining that gas storage caverns are vertically arranged based on geological conditions, gas storage scale and construction land; the method comprises the following steps: establishing a stress field-thermal field coupling model of an underground high-pressure lining gas storage system based on surrounding rock geological conditions, ground stress and a gas storage cavern structure, and calculating and determining gas storage pressure; a plurality of spaced gas storage caverns are arranged, and every two adjacent gas storage caverns are communicated through a construction roadway; the semispherical arch bottom, the circumferential tank wall and the semispherical arch top of the gas storage cavern are sequentially connected through an upside-down mounting method; and in the layered concrete pouring process of the circumferential tank wall of the gas storage cavern, water is injected into a containing space formed by the circumferential tank wall and the hemispherical arch bottom in a layered mode. According to the vertical underground high-pressure lining gas storage and the construction method thereof, the pressure bearing capacity and economical efficiency of the gas storage cavern can be improved, so that internal and external pressure balance of concrete and water inside and outside the circumferential tank wall is kept, and it is guaranteed that the circumferential tank wall cannot be damaged by the pressure difference generated by the concrete and the water.

Description

Technical Field

[0001] The embodiments disclosed herein belong to the field of underground energy storage technology, specifically relating to a vertical underground high-pressure lined gas storage facility and its construction method. Background Technology

[0002] Underground gas storage facilities are a primary means of gas storage and peak shaving systems, and their construction is essential for achieving national planning and policy objectives and improving national reserve levels.

[0003] Currently, underground gas storage facilities are mainly constructed in the form of depleted oil and gas reservoirs, salt caverns, and aquifers. However, the site selection suitability for all three types of gas storage facilities is extremely limited. Surface gas storage facilities mainly use liquefied natural gas (LNG) tanks. Underground high-pressure lined gas storage facilities only require the selection of hard and intact rock masses. The eastern and southern regions of my country, where gas consumption is most concentrated, have a wide distribution of hard and intact rock strata, making their site selection suitability far superior to that of oil and gas reservoirs, salt caverns, and LNG storage facilities.

[0004] Underground high-pressure lined gas storage facilities only require the selection of hard, intact rock masses, making their site selection far more suitable than other gas storage facilities, thus attracting widespread attention from research institutions both domestically and internationally. However, the development of underground high-pressure lined gas storage facilities is still in its early stages, with no mature construction cases yet, indicating significant room for technological advancement. Therefore, there is an urgent need for a large-scale underground high-pressure lined gas storage facility and its construction method. Summary of the Invention

[0005] The embodiments disclosed herein aim to at least solve one of the technical problems existing in the prior art, and provide a vertical underground high-pressure lined gas storage facility and its construction method.

[0006] An embodiment of this disclosure provides a method for constructing a vertical underground high-pressure lined gas storage facility, the method comprising the following steps:

[0007] Step 1: Based on geological conditions, gas storage scale, and construction land, determine that the gas storage caverns are arranged vertically. The burial depth of the gas storage caverns ranges from 100 to 150 meters, the inner diameter of the gas storage caverns ranges from 35 to 50 meters, and the height of the gas storage caverns ranges from 50 to 110 meters.

[0008] Step 2: Based on the surrounding rock geological conditions, in-situ stress, and gas storage cavern structure, establish a stress field-thermal field coupling model for the underground high-pressure lined gas storage system, and calculate the gas storage pressure of the gas storage cavern using the stress field-thermal field coupling model.

[0009] Step 3: Set up multiple gas storage caverns, with the multiple gas storage caverns spaced apart and at the same height. A construction tunnel is set between two adjacent gas storage caverns to connect them. A vertical shaft is set at the top of each gas storage cavern.

[0010] Step 4: Construct the hemispherical arch bottom of the gas storage cavern, build the circumferential tank wall of the gas storage cavern on the basis of the hemispherical arch bottom, prefabricate the hemispherical arch top, and lift the hemispherical arch top on the basis of the circumferential tank wall using the inverted method.

[0011] Step 5: During the process of pouring concrete in layers along the height direction of the gas storage chamber, water is injected in layers into the containment space formed by the circumferential tank wall and the hemispherical arch bottom.

[0012] In some embodiments of this disclosure, the distance between two adjacent gas storage chambers is greater than or equal to 1.4 times the outer diameter of the gas storage chamber.

[0013] In some embodiments of this disclosure, the distance between two adjacent gas storage chambers is equal to twice the outer diameter of the gas storage chamber.

[0014] In some embodiments of this disclosure, the gas storage cavern is buried at a depth of 150 meters.

[0015] In some embodiments of this disclosure, the step of establishing a stress-thermal field coupling model of the underground high-pressure lined gas storage system based on surrounding rock geological conditions, in-situ stress, and gas storage cavern structure, and calculating the gas storage pressure of the gas storage cavern using the stress-thermal field coupling model, specifically includes:

[0016] Based on the surrounding rock geological conditions, in-situ stress, and gas storage cavern structure, a stress field-thermal field coupled model of the underground high-pressure lined gas storage system is established.

[0017] Set different gas storage pressures for the stress field-thermal field coupling model;

[0018] Calculate the stress in the stress-thermal field coupling model under different pressure parameters;

[0019] The gas storage pressure of the gas storage chamber is determined based on the stress in the stress-thermal field coupling model.

[0020] In some embodiments of this disclosure, the construction tunnel includes a main tunnel and three branch tunnels, the three branch tunnels being connected to the main tunnel respectively, and the three branch tunnels being spaced apart along the height direction of the gas storage cavern.

[0021] In some embodiments of this disclosure, the three branch tunnels are respectively located at the top, middle and bottom of the gas storage chamber.

[0022] In some embodiments of this disclosure, before constructing the hemispherical arch base of the gas storage cavern, constructing the circumferential tank wall of the gas storage cavern on the basis of the hemispherical arch base, prefabricating the hemispherical dome, and lifting the hemispherical dome using an inverted method on the basis of the circumferential tank wall, the following steps are also included:

[0023] A geometric model of the gas storage cavity was established using ANSYS software.

[0024] Set the parameters of the geometric model of the gas storage cavity;

[0025] Calculate the deformation of a vertically arranged gas storage cavity during construction;

[0026] Based on the deformation and maximum stress of the gas storage cavern during construction, determine whether the gas storage cavern meets the strength and stiffness requirements.

[0027] In some embodiments of this disclosure, during the process of layering concrete pouring for the circumferential tank wall of the gas storage chamber along its height direction, before layering water injection into the receiving space formed by the circumferential tank wall and the hemispherical arch bottom, the following steps are further included:

[0028] A geometric model of the gas storage cavity was established using ANSYS software.

[0029] Set the parameters of the geometric model of the gas storage cavity;

[0030] Calculate the radial deformation and stress value of a vertically arranged gas storage cavity during the layered casting process of the circumferential tank wall;

[0031] Based on the fact that the radial deformation of the circumferential tank wall during the layered casting process is less than the radial deformation threshold, and based on the fact that the stress value of the circumferential tank wall during the layered casting process is less than the stress threshold, the maximum height of a single casting of the circumferential tank wall of the gas storage cavern is determined.

[0032] This disclosure also proposes a vertical underground high-pressure lined gas storage facility, wherein the underground hydrogen storage facility is constructed according to the construction method of the vertical underground high-pressure lined gas storage facility described in any of the above embodiments, and the vertical underground high-pressure lined gas storage facility includes:

[0033] Multiple gas storage chambers are arranged at intervals and at the same height. The gas storage chambers are arranged vertically. The burial depth of the gas storage chambers ranges from 100 to 150 meters, the inner diameter of the gas storage chambers ranges from 35 to 50 meters, and the height of the gas storage chambers ranges from 50 to 110 meters. Each gas storage chamber includes a hemispherical arched bottom, a hemispherical arched top, and a circumferential tank wall. The arched bottom, the circumferential tank wall, and the arched top are connected in sequence to form a closed gas storage space.

[0034] Construction tunnels are provided between two adjacent gas storage caverns to connect them. The construction tunnels include a main tunnel and three branch tunnels. The three branch tunnels are respectively connected to the main tunnel and are respectively located at the top, middle and bottom of the gas storage caverns.

[0035] A vertical shaft is provided at the top of each of the gas storage chambers.

[0036] This disclosure discloses a vertical underground high-pressure lined gas storage facility and its construction method. Based on geological conditions, gas storage scale, and construction land, the gas storage caverns are arranged vertically. The burial depth of the gas storage caverns ranges from 100 to 150 meters, the inner diameter ranges from 35 to 50 meters, and the height ranges from 50 to 100 meters, in order to improve the pressure-bearing capacity and economy of the gas storage caverns. Based on the surrounding rock geological conditions, in-situ stress, and the structure of the gas storage caverns, a stress-thermal field coupling model of the underground high-pressure lined gas storage facility system is established to simulate the stress-thermal field coupling model under different gas storage pressures, thereby determining the gas storage pressure of the gas storage caverns. The system consists of multiple spaced gas storage chambers connected by construction tunnels. Each chamber has a vertical shaft at its top for air intake and exhaust. The construction process involves first building a hemispherical arch base, then constructing a circular tank wall on top of the arch base, prefabricating a hemispherical dome, and finally lifting the dome using an inverted method on top of the circular tank wall. The circular tank wall is formed by pouring concrete layer by layer, while water is injected layer by layer into the circular tank wall to maintain the internal and external pressure balance between the concrete and water, ensuring that the pressure difference between the concrete and water does not damage the circular tank wall. Attached Figure Description

[0037] Figure 1 This is a logic flowchart of a construction method for a vertical underground high-pressure lined gas storage facility according to an embodiment of the present disclosure.

[0038] Figure 2 This is a cross-sectional layout diagram of a vertical underground high-pressure lined gas storage facility according to an embodiment of this disclosure;

[0039] Figure 3 for Figure 2 The diagram shows the plan layout of the vertical underground high-pressure lined gas storage facility.

[0040] Figure 4 This is a schematic diagram of the structure of the gas storage chamber according to an embodiment of the present disclosure;

[0041] Figure 5 This is a cross-sectional view of the gas storage chamber according to an embodiment of this disclosure;

[0042] Figure 6 This is a schematic diagram of the dome structure of the gas storage cavern according to an embodiment of the present disclosure;

[0043] Figure 7 This is a schematic diagram of the arched bottom structure of the gas storage chamber according to an embodiment of the present disclosure;

[0044] Figure 8 The simulated cloud diagram (Pa) of the maximum principal stress of the gas storage cavity in this embodiment of the present disclosure at a storage pressure of 15 MPa;

[0045] Figure 9 The simulated minimum principal stress (Pa) of the gas storage cavity in this embodiment of the present disclosure at a storage pressure of 15 MPa is shown in the cloud diagram.

[0046] Figure 10 The equivalent plastic strain simulation cloud diagram of the gas storage cavity in this embodiment of the present disclosure under a storage pressure of 15 MPa;

[0047] Figure 11 This is a simulated contour map (Pa) of the maximum principal stress in the gas storage cavity of this embodiment under a storage pressure of 20 MPa;

[0048] Figure 12 This is a simulated contour map (Pa) of the maximum principal stress in the gas storage cavity of this embodiment under a storage pressure of 20 MPa;

[0049] Figure 13 This is a simulated cloud diagram of the equivalent plastic strain of the gas storage cavity under a storage pressure of 20 MPa, according to an embodiment of this disclosure.

[0050] Figure 14 The simulated cloud diagram (Pa) of the maximum principal stress of the gas storage cavity in this embodiment of the present disclosure at a storage pressure of 25 MPa;

[0051] Figure 15 The simulated minimum principal stress (Pa) of the gas storage cavity in this embodiment of the present disclosure at a storage pressure of 25 MPa is shown in the cloud diagram.

[0052] Figure 16 The equivalent plastic strain simulation cloud diagram of the gas storage cavity in this embodiment of the present disclosure under a storage pressure of 25 MPa;

[0053] Figure 17 The simulated cloud diagram (Pa) of the maximum principal stress of the gas storage cavity in this embodiment of the present disclosure at a storage pressure of 30 MPa;

[0054] Figure 18 The simulated minimum principal stress (Pa) of the gas storage cavity in this embodiment of the present disclosure at a storage pressure of 30 MPa is shown in the cloud diagram.

[0055] Figure 19 The equivalent plastic strain simulation cloud diagram of the gas storage cavity in this embodiment of the present disclosure under a storage pressure of 30 MPa;

[0056] Figure 20 for Figure 2 The geometric model diagram of the gas storage cavity is shown.

[0057] Figure 21 for Figure 20 The diagram shows a simulation of the self-weight load of the gas storage cavity.

[0058] Figure 22 for Figure 20 The diagram shows a simulation of the uniformly distributed live load assignment during the construction of the arch of the gas storage cavern.

[0059] Figure 23 for Figure 20 The diagram shows a simulation of the fixed support at the bottom of the gas storage cavity.

[0060] Figure 24 for Figure 20 The diagram shows the overall deformation cloud of the gas storage cavity;

[0061] Figure 25 for Figure 20 The vertical deformation cloud diagram of the gas storage cavity is shown.

[0062] Figure 26 for Figure 20 The diagram shows the radial deformation contour of the circumferential tank wall of the gas storage chamber.

[0063] Figure 27 for Figure 20 The Mises stress cloud diagram of the gas storage cavity is shown.

[0064] Figure 28 for Figure 20 The diagram shows the Mises stress cloud of the vault of the gas storage chamber.

[0065] Figure 29 for Figure 20 The diagram shows the Mises stress cloud of the circumferential tank wall of the gas storage cavity.

[0066] Figure 30 for Figure 20 The static water pressure on the inner surface of the gas storage tunnel shown (water injection height is 5m above the bottom of the circumferential tank wall);

[0067] Figure 31 for Figure 20 The static concrete pressure on the outdoor surface of the gas storage tunnel shown (the concrete pouring height is 5m above the bottom of the circumferential tank wall);

[0068] Figure 32 for Figure 20 The diagram shows the overall deformation cloud of the gas storage chamber (the concrete pouring height is 5m above the bottom of the circumferential tank wall);

[0069] Figure 33 for Figure 20 The diagram shows the radial deformation cloud of the concrete pouring layer of the gas storage cavern (the concrete pouring height is 5m above the bottom of the circumferential tank wall).

[0070] Figure 34 for Figure 20 The stress cloud diagram of the concrete pouring layer of the gas storage cavern is shown (the concrete pouring height is 5m above the bottom of the circumferential tank wall).

[0071] Figure 35 for Figure 20 The hydrostatic pressure on the inner surface of the gas storage chamber shown (water injection height is 10m above the bottom of the circumferential tank wall);

[0072] Figure 36 for Figure 20 The static concrete pressure on the outer surface of the gas storage chamber shown (the concrete pouring height is 10m above the bottom of the circumferential tank wall);

[0073] Figure 37 for Figure 20 The overall deformation cloud diagram of the gas storage cavern shown (the concrete pouring height is 10m above the bottom of the circumferential tank wall);

[0074] Figure 38 for Figure 20 The radial deformation cloud diagram of the concrete pouring layer of the gas storage cavern is shown (the concrete pouring height is 10m above the bottom of the circumferential tank wall).

[0075] Figure 39 for Figure 20 The stress cloud diagram of the concrete pouring layer of the gas storage cavern is shown (the concrete pouring height is 10m above the bottom of the circumferential tank wall);

[0076] Figure 40 for Figure 20 The hydrostatic pressure on the inner surface of the gas storage chamber shown (water injection height is 9m above the bottom of the circumferential tank wall);

[0077] Figure 41 for Figure 20 The static concrete pressure on the outer surface of the gas storage chamber shown (concrete pouring height is 9m above the bottom of the circumferential tank wall);

[0078] Figure 42 for Figure 20 The overall deformation cloud diagram of the gas storage cavity shown (the concrete pouring height is 9m above the bottom of the circumferential tank wall);

[0079] Figure 43 for Figure 20 The radial deformation cloud diagram of the concrete pouring layer of the gas storage cavern is shown (the concrete pouring height is 9m above the bottom of the circumferential tank wall);

[0080] Figure 44 for Figure 20 The stress cloud diagram of the concrete pouring layer of the gas storage cavern is shown (the concrete pouring height is 9m above the bottom of the circumferential tank wall).

[0081] Figure label:

[0082] 100. Vertical underground high-pressure lined gas storage facility;

[0083] 10. Gas storage chamber; 11. Arched bottom; 12. Circumferential tank wall; 13. Arched bottom;

[0084] 20. Construction tunnel; 21. Main tunnel; 22. Branch tunnel;

[0085] 30. Shaft. Detailed Implementation

[0086] To enable those skilled in the art to better understand the technical solutions of this disclosure, the disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0087] like Figures 1 to 7 As shown, this disclosure proposes a vertical underground high-pressure lined gas storage facility. The underground hydrogen storage facility is constructed according to the construction method of the vertical underground high-pressure lined gas storage facility described in any embodiment of this disclosure. The vertical underground high-pressure lined gas storage facility includes: multiple gas storage chambers, construction tunnels, and shafts. Specifically, the multiple gas storage chambers are spaced apart and located at the same height. Each gas storage chamber is arranged vertically, with a burial depth ranging from 100 to 150 meters and an inner diameter ranging from 35 to 50 meters. The height of the gas storage cavern ranges from 50 to 110 meters. The gas storage cavern includes a hemispherical arched bottom, a hemispherical arched top, and a circular tank wall. The arched bottom, the circular tank wall, and the arched top are connected in sequence to form a closed gas storage space. Construction tunnels are set between two adjacent gas storage caverns to connect with each other. The construction tunnels include a main tunnel and three branch tunnels. The three branch tunnels are connected to the main tunnel respectively. The three branch tunnels are located at the top, middle, and bottom of the gas storage cavern. A vertical shaft is set at the top of each gas storage cavern. The branch tunnels located at the top of the gas storage cavern are connected to each vertical shaft.

[0088] Another embodiment of this disclosure provides a method for constructing a vertical underground high-pressure lined gas storage facility, the method comprising the following steps:

[0089] Step 1: Based on geological conditions, gas storage scale, and construction land, determine that the gas storage caverns are arranged vertically. The burial depth of the gas storage caverns ranges from 100 to 150 meters, the inner diameter of the gas storage caverns ranges from 35 to 50 meters, and the height of the gas storage caverns ranges from 50 to 110 meters.

[0090] Step 2: Based on the surrounding rock geological conditions, in-situ stress, and gas storage cavern structure, establish a stress field-thermal field coupling model for the underground high-pressure lined gas storage system, and calculate the gas storage pressure of the gas storage cavern using the stress field-thermal field coupling model.

[0091] Step 3: Set up multiple gas storage caverns, with the multiple gas storage caverns spaced apart and at the same height. A construction tunnel is set between two adjacent gas storage caverns to connect them. A vertical shaft is set at the top of each gas storage cavern.

[0092] Step 4: Construct the hemispherical arch bottom of the gas storage cavern, build the circumferential tank wall of the gas storage cavern on the basis of the hemispherical arch bottom, prefabricate the hemispherical arch top, and lift the hemispherical arch top on the basis of the circumferential tank wall using the inverted method.

[0093] Step 5: During the process of pouring concrete in layers along the height direction of the gas storage chamber, water is injected in layers into the containment space formed by the circumferential tank wall and the hemispherical arch bottom.

[0094] According to the vertical underground high-pressure lined gas storage facility and its construction method disclosed herein, based on geological conditions, gas storage scale, and construction land, the gas storage caverns are determined to be arranged vertically. The burial depth of the gas storage caverns ranges from 100 to 150 meters, the inner diameter ranges from 35 to 50 meters, and the height ranges from 50 to 100 meters, in order to improve the pressure-bearing capacity and economy of the gas storage caverns. Based on the surrounding rock geological conditions, in-situ stress, and the structure of the gas storage caverns, a stress-thermal field coupling model of the underground high-pressure lined gas storage facility system is established to simulate the stress-thermal field coupling model under different gas storage pressures, thereby determining the gas storage capacity of the gas storage caverns. Pressure; Multiple gas storage chambers are set up at intervals, and the multiple gas storage chambers are connected by construction tunnels to realize the connection between the multiple gas storage chambers. A vertical shaft is set at the top of each gas storage chamber to realize the intake and exhaust of the gas storage chamber. The construction process of the gas storage chamber is as follows: first, a hemispherical arch base is built, and then a circular tank wall is built on the arch base. A hemispherical arch is prefabricated. The arch is lifted by inverted installation on the basis of the circular tank wall. The circular tank wall is formed by pouring concrete layer by layer. At the same time, water is injected into the circular tank wall layer by layer to maintain the internal and external pressure balance of concrete and water, and to ensure that the pressure difference between concrete and water will not damage the circular tank wall.

[0095] Step 1: Based on geological conditions, gas storage scale, and construction land, determine that the gas storage caverns are arranged vertically, with a burial depth of 100-150 meters, an inner diameter of 35-50 meters, and a height of 50-110 meters.

[0096] For example, 2 to Figure 7As shown, the gas storage cavern is a vertical oval shape, with a top height of 20m and a three-centered arched shape. The central arched sphere has a radius of 21.75m and an arc of 87°, while the left and right sides each have an arched sphere with a radius of 19.33m and an arc of 46°. The central straight wall section is 70m high and is cylindrical with a diameter of 42m. The bottom is 15m high and also has a three-centered arched shape, with a central arched sphere having a radius of 27.36m and an arc of 71°, while the left and right sides each have an arched sphere with a radius of 12.17m and an arc of 54°. The perimeter is 261.48m, the net area is 4095.52m², and the net space is 134,300 cubic meters.

[0097] Based on experience with large underground caverns both domestically and internationally, the net distance between two adjacent gas storage chambers should not be less than 1.4 times the width of the chamber. Statistical analysis from actual engineering examples shows that when the net distance between underground gas storage chambers is less than twice the width of the chamber, a plastic zone will form between the lower edge and the middle of the chamber's sidewall, negatively impacting the stability of the surrounding rock. Therefore, in this embodiment, the distance between the outer walls of each gas storage chamber is considered to be twice the width of the chamber.

[0098] The burial depth of the gas storage cavern has a significant impact on its excavation deformation and stability. Increasing the burial depth helps reduce tensile stress damage to the concrete lining layer and prevents ground heave and large deformation damage under maximum storage pressure. Therefore, provided that the construction cost allows, the burial depth can be appropriately increased to suppress plastic deformation of the lining layer and prevent ground heave. The burial depth range for vertical underground high-pressure lined gas storage facilities is 100–150 m, and detailed calculations can be performed based on the specific storage pressure, cavern shape, and layout scheme. In this embodiment, the calculated burial depth of the gas storage cavern is 150 m.

[0099] Step 2: Based on the surrounding rock geological conditions, in-situ stress, and gas storage cavern structure, establish a stress field-thermal field coupling model for the underground high-pressure lined gas storage system, and calculate the gas storage pressure of the gas storage cavern using the stress field-thermal field coupling model.

[0100] The storage pressure range within a gas cavern is closely related to the injection and production process, coupled stress field, and reservoir structure. For the stability of the underground structure, the reliability of each structural layer during operation is primarily considered, namely strength, stiffness, and stability. Based on the surrounding rock geological conditions, in-situ stress, and the gas cavern structure, a coupled stress-thermal field model of the underground high-pressure lined gas storage system is established. Various pressure range conditions are set, and through numerical simulation and coupled stress analysis, the circumferential strain rate coordination and strength yielding behavior of each structural layer under various conditions are analyzed.

[0101] The operation of underground gas storage caverns involves complex gas injection and extraction processes. Under high-pressure gas storage conditions, gas movement causes the surrounding temperature to rise, while the gas storage cavern is vented, causing the surrounding temperature to drop. At the same time, the operation of gas injection and extraction will generate thermal convection. Therefore, the operation of gas storage caverns involves complex changes in thermal-structural coupling. To simplify the numerical analysis, thermal convection energy transfer is not considered, and only the mechanical response of the temperature field and stress field of the gas storage cavern caused by heat conduction is considered.

[0102] In an elastic body, the stress caused by temperature changes is called thermal stress. When an object expands freely but is constrained, and the temperature distribution is uniform, no thermal stress will be generated. When a structure is composed of several parts, and the temperature changes uniformly and is constrained by external factors, the different coefficients of thermal expansion α of various materials, or the different expansion methods, cause the various structural parts to constrain each other, thus generating different temperature stress fields.

[0103] Since thermal expansion results in linear or volumetric expansion without shear strain, it conforms to the generalized Hooke's law when analyzing different gas storage conditions in gas storage caverns: In the formula: σ1, σ2, and σ3 are the first, second, and third principal stresses, respectively; ν is Poisson's ratio; and α is the coefficient of linear expansion. The gas storage facility in this embodiment can operate at a pressure range of 0-30 MPa. Within this range, it undergoes daily pressurization and depressurization cycles of 0-4 times per day. The temperature field of the gas storage chamber is assumed to be 20°C during construction, reaching a peak temperature of 30 MPa, and then 60°C when the gas pressure reaches its peak value of 30 MPa. Finally, the temperature reaches 0°C when the gas pressure is vented to 0 MPa.

[0104] In this embodiment, the storage medium is compressed air, with very low water and oil content. Since the temperature variation in the gas storage chamber is within the range of 0–60°C, based on the thermal stress linear expansion coefficients of the concrete lining and the inner steel plate sealing layer, the linear expansion coefficient α of concrete is 1.5 × 10⁻⁶ within the range of 0–100°C. -5 The coefficient of linear expansion α of steel is 1.2 × 10⁻⁶. -5 The linear expansion coefficients of concrete and steel are input into the stress-thermal field coupling model, respectively.

[0105] In this embodiment, the gas storage cavern has a burial depth of 150m, an inner diameter of 42m, and a distance of 84m between two adjacent gas storage caverns. Using these figures as an example, the stress results for the gas storage cavern with a pressure range of 10–30MPa are calculated. Specifically, the gas storage pressures set for the stress-thermal field coupling model are 10MPa, 15MPa, 20MPa, 25MPa, and 30MPa.

[0106] The simulation results of this embodiment are as follows:

[0107] 1) such as Figures 8-10 As shown, when the storage pressure is 10-15 MPa, simulation calculations indicate that all surrounding rock stress units are subjected to compressive stress, which can serve as an ideal reservoir structure. However, the material strength is not fully utilized, limiting the gas storage capacity and resulting in a conservative design. No damaged areas appear in the surrounding rock. This storage pressure is suitable for small to medium-sized gas storage facilities.

[0108] 2) such as Figures 11-16 As shown, when the storage pressure is 20-25 MPa, simulation calculations indicate that the maximum principal stress at the arch crown and arch bottom is tensile stress. If the concrete strength grade of the lining layer is C35-C45, then tensile reinforcement of some structural layers needs to be considered, i.e., increasing the flexural section modulus of the lining layer, etc. Overall, this storage pressure can be used as the design storage pressure; no damaged areas were found in the surrounding rock. This storage pressure is suitable for medium and large-sized gas storage facilities.

[0109] 3) such as Figures 17-19 As shown, when the storage pressure is 30 MPa, simulation calculations indicate that the maximum principal stress at the arch crown and arch base is tensile stress, approximately 9.21 MPa. Both the maximum principal stress at the arch crown and arch base exceed the tensile stress borne by the lining layer. Therefore, the lining layer of the gas storage cavern in this embodiment cannot meet the tensile strength requirements; and damaged areas appear in the surrounding rock at the dome. This storage pressure is not recommended in this embodiment.

[0110] In summary, the maximum gas storage pressure of this embodiment is set to 25 MPa.

[0111] Step 3: Set up multiple gas storage caverns, spaced apart, at the same height, with construction tunnels connecting adjacent gas storage caverns, and a vertical shaft at the top of each gas storage cavern.

[0112] In some embodiments of this disclosure, the construction tunnel includes a main tunnel and three branch tunnels, each connected to the main tunnel. The three branch tunnels are spaced apart along the height of the gas storage chamber. Specifically, the main tunnel slopes downwards from the ground surface to connect with the three branch tunnels, facilitating excavation and equipment installation. The main tunnel is a straight-walled arched tunnel with a cross-section of 18m x 10m and four lanes. The branch tunnels are also straight-walled arched tunnels with a cross-section of 9m x 8m and two lanes, a perimeter of 30.47m, and an area of ​​64.51 square meters. The total length of the construction tunnel is 10728m. The slope of the construction tunnel is less than or equal to 13%, specifically, the average slope is 10%.

[0113] In some embodiments of this disclosure, three branch tunnels are respectively located at the top, middle, and bottom of the gas storage chamber, and the main tunnel slopes downwards from the ground surface to connect with the three branch tunnels located at the top, middle, and bottom of the gas storage chamber. A tunnel sealing plug is provided at the connection point between each of the three branch tunnels and each gas storage chamber, and the thickness of the tunnel sealing plug is 10m. In this embodiment, there are 14 gas storage chambers, totaling 42 tunnel sealing plugs.

[0114] In some embodiments of this disclosure, each gas storage chamber has a process shaft at its top, with a diameter of 6m and an average burial depth of 124m. A shaft sealing plug is installed at the connection between the shaft and the top of the gas storage chamber, with a casting thickness of 8m. In this embodiment, there are 14 gas storage chambers, totaling 14 shaft sealing plugs.

[0115] Step 4: Construct the hemispherical arch base of the gas storage chamber, build the circumferential tank wall of the gas storage chamber on the basis of the hemispherical arch base, prefabricate the hemispherical arch, and lift the hemispherical arch using the inverted method on the basis of the circumferential tank wall.

[0116] Specifically, the construction of the hemispherical structure at the bottom of the gas storage chamber was carried out first. Then, the hemispherical arch bottom was prefabricated, and the egg-shaped top was lifted using the inverted method used on oil tanks. During the lifting process, water was injected into the gas storage tank to balance the load during the external concrete pouring.

[0117] The lining plates of a vertically structured gas storage cavern do not bear high pressure or other pressures during operation, but construction loads need to be considered during construction. In the inverted installation method, the arch structure needs to be self-supporting and able to withstand a uniformly distributed construction load of 1200 Pa.

[0118] Before step four, simulation calculations are required to determine whether the gas storage cavern meets the strength and stiffness requirements.

[0119] Specifically, firstly, a geometric model of the gas storage cavity is established based on ANSYS software (e.g., Figures 20-22 (As shown), then set the material and boundary conditions parameters of the geometric model, and then calculate the deformation of the gas storage cavern during the construction process. Based on the deformation and maximum stress of the gas storage cavern during the construction process, determine whether the gas storage cavern meets the strength and stiffness requirements. At the same time, based on the deformation and maximum stress of the gas storage cavern during the construction process, adjust the parameters of each part of the gas storage cavern to determine the geometric parameters of the dome, circumferential tank wall and dome of the gas storage cavern.

[0120] like Figures 23-29As shown, this embodiment of the present disclosure simulates and calculates whether the gas storage cavern will buckle and collapse. The simulation results show that, under its own weight and construction live load, the maximum deformation displacement of the vertical gas storage cavern is 2.2 mm, which is less than the deformation threshold of 140 mm; the maximum stress is 11.4 MPa, which is less than the prestressed stress of 189 MPa. Therefore, the gas storage cavern in this embodiment meets the strength and stiffness requirements under its own weight and construction live load conditions.

[0121] Step 5: During the process of pouring concrete in layers along the height of the gas storage chamber, water is injected in layers into the containment space formed by the circumferential tank wall and the hemispherical arch bottom.

[0122] In this embodiment, the vertical structure of the gas storage cavern has a diameter of 42m but a wall thickness of only 14mm. Under the conditions of concrete pouring and water injection into the vertical structure of the gas storage cavern, the thin-walled structure of the gas storage cavern is prone to yielding failure. Therefore, concrete pouring and water injection into the vertical structure of the gas storage cavern need to be carried out in sections and layers to ensure that the pressure difference between concrete and water due to density will not cause damage.

[0123] During the concrete pouring process of the vertical gas storage cavern, water is injected into the cavern to maintain pressure balance between the inside and outside. Therefore, the inner surface of the vertical gas storage cavern is subjected to hydrostatic pressure.

[0124] Before step five, a simulation calculation is required to determine the maximum height of a single pour of the circumferential tank wall of the gas storage cavern. Specifically, first, a geometric model of the gas storage cavern is established using ANSYS software; then, the parameters of the geometric model of the gas storage cavern are set; next, the radial deformation and stress values ​​of the vertically arranged gas storage cavern during the layered pouring process of the circumferential tank wall are calculated; finally, based on the fact that the radial deformation of the circumferential tank wall during the layered pouring process is less than the radial deformation threshold, and based on the fact that the stress value of the circumferential tank wall during the layered pouring process is less than the stress threshold, the maximum height of a single pour of the circumferential tank wall of the gas storage cavern is determined.

[0125] The simulation results of this embodiment are as follows:

[0126] 1) Concrete pouring height 5m

[0127] When the concrete pouring height is 5m, the stress on the vertical gas storage cavern is as follows: Figures 30-34 As shown.

[0128] Based on the above calculations, because the concrete pressure on the outer wall of the vertical gas storage tunnel is greater than the hydrostatic pressure inside the tunnel, the circumferential tank wall experiences radial displacement close to the model's axis. The maximum radial deformation is 10.4 mm, which does not exceed the 1 / 300 deformation requirement and is less than the radial deformation threshold of 140 mm. The stress at this point is also the maximum, at 82.3 MPa. This stress value is less than the stress threshold of 189 MPa, meaning it does not exceed the material's allowable stress.

[0129] 2) Concrete pouring height 10m

[0130] When the concrete pouring height is 10m, the stress on the vertical gas storage cavern is as follows: Figures 35-39 As shown.

[0131] Based on the above calculations, because the concrete pressure on the outer wall of the vertical gas storage tunnel is greater than the hydrostatic pressure inside the tunnel, the circumferential tank wall experiences a radial displacement close to the model's axis, with a maximum of 27.6 mm. This maximum radial deformation of 27.6 mm is less than the radial deformation threshold of 140 mm, and does not exceed the deformation requirement of 1 / 300. The stress at this point is also the maximum, at 208 MPa. This stress value is greater than the stress threshold of 189 MPa, meaning the stress at this point exceeds the material's allowable stress.

[0132] 3) Maximum allowable concrete pouring height

[0133] When the concrete pouring height is increased from 5m to 10m, the lining structure of the vertical gas storage tunnel does not meet the strength requirements. Therefore, the maximum allowable pouring height is obtained by gradually reducing the pouring height, as shown in the figure below.

[0134] When the concrete pouring height is 9m, the stress on the vertical gas storage cavern is as follows: Figures 40-44 As shown.

[0135] Based on the above calculations, when the concrete pouring height is 9m, the cylinder will experience a radial displacement close to the model's axis, with a maximum of 24.1mm. This maximum radial deformation of 24.1mm is less than the radial deformation threshold of 140mm, and does not exceed the deformation requirement of 1 / 300. The stress at this point is also the maximum, at 183MPa. This stress value is less than the stress threshold of 189MPa, and just below the allowable material stress of 189MPa. Therefore, the maximum permissible concrete pouring height in this embodiment is 9m.

[0136] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of this disclosure, and this disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and these modifications and improvements are also considered to be within the scope of protection of this disclosure.

Claims

1. A method for constructing a vertical underground high-pressure lined gas storage facility, characterized in that, The construction method includes the following steps: Step 1: Based on geological conditions, gas storage scale, and construction land, determine that the gas storage caverns are arranged vertically. The burial depth of the gas storage caverns ranges from 100 to 150 meters, the inner diameter of the gas storage caverns ranges from 35 to 50 meters, and the height of the gas storage caverns ranges from 50 to 110 meters. Step 2: Based on the surrounding rock geological conditions, in-situ stress, and gas storage cavern structure, establish a stress field-thermal field coupling model for the underground high-pressure lined gas storage system, and calculate the gas storage pressure of the gas storage cavern using the stress field-thermal field coupling model. Step 3: Set up multiple gas storage caverns, with the multiple gas storage caverns spaced apart and at the same height. A construction tunnel is set between two adjacent gas storage caverns to connect them. A vertical shaft is set at the top of each gas storage cavern. Step 4: Construct the hemispherical arch bottom of the gas storage cavern, build the circumferential tank wall of the gas storage cavern on the basis of the hemispherical arch bottom, prefabricate the hemispherical arch top, and lift the hemispherical arch top on the basis of the circumferential tank wall using the inverted method. Step 5: During the process of pouring concrete in layers along the height direction of the gas storage chamber, water is injected in layers into the containment space formed by the circumferential tank wall and the hemispherical arch bottom.

2. The construction method of the vertical underground high-pressure lined gas storage facility according to claim 1, characterized in that, The distance between two adjacent gas storage chambers is greater than or equal to 1.4 times the outer diameter of the gas storage chamber.

3. The construction method of the vertical underground high-pressure lined gas storage facility according to claim 2, characterized in that, The distance between two adjacent gas storage chambers is equal to twice the outer diameter of the gas storage chamber.

4. The construction method of the vertical underground high-pressure lined gas storage facility according to claim 1, characterized in that, The gas storage cavern is buried at a depth of 150 meters.

5. The construction method of the vertical underground high-pressure lined gas storage facility according to claim 1, characterized in that, Based on the surrounding rock geological conditions, in-situ stress, and gas storage cavern structure, a stress-thermal field coupled model of the underground high-pressure lined gas storage system is established. The gas storage pressure of the gas storage cavern is determined by calculating this coupled model. Specifically, this includes: Based on the surrounding rock geological conditions, in-situ stress, and gas storage cavern structure, a stress field-thermal field coupled model of the underground high-pressure lined gas storage system is established. Set different gas storage pressures for the stress field-thermal field coupling model; Calculate the stress in the stress-thermal field coupling model under different pressure parameters; The gas storage pressure of the gas storage chamber is determined based on the stress in the stress-thermal field coupling model.

6. The construction method of the vertical underground high-pressure lined gas storage facility according to claim 1, characterized in that, The construction tunnel includes a main tunnel and three branch tunnels, which are connected to the main tunnel and are spaced apart along the height of the gas storage cavern.

7. The construction method of the vertical underground high-pressure lined gas storage facility according to claim 6, characterized in that, The three branch tunnels are respectively located at the top, middle and bottom of the gas storage chamber.

8. The construction method of the vertical underground high-pressure lined gas storage facility according to claim 1, characterized in that, The construction of the hemispherical arch base of the gas storage cavern, the construction of the circumferential tank wall of the gas storage cavern based on the hemispherical arch base, the prefabrication of the hemispherical arch top, and the lifting of the hemispherical arch top using the inverted method based on the circumferential tank wall, further includes the following steps: A geometric model of the gas storage cavity was established using ANSYS software. Set the parameters of the geometric model of the gas storage cavity; Calculate the deformation of a vertically arranged gas storage cavity during construction; Based on the deformation and maximum stress of the gas storage cavern during construction, determine whether the gas storage cavern meets the strength and stiffness requirements.

9. The construction method of the vertical underground high-pressure lined gas storage facility according to claim 1, characterized in that, During the process of pouring concrete in layers along the height direction of the gas storage chamber, before filling the space formed by the circumferential tank wall and the hemispherical arch bottom with water in layers, the following steps are also included: A geometric model of the gas storage cavity was established using ANSYS software. Set the parameters of the geometric model of the gas storage cavity; Calculate the radial deformation and stress value of a vertically arranged gas storage cavity during the layered casting process of the circumferential tank wall; Based on the fact that the radial deformation of the circumferential tank wall during the layered casting process is less than the radial deformation threshold, and based on the fact that the stress value of the circumferential tank wall during the layered casting process is less than the stress threshold, the maximum height of a single casting of the circumferential tank wall of the gas storage cavern is determined.

10. A vertical underground high-pressure lined gas storage facility, characterized in that, The underground hydrogen storage facility is constructed using the construction method of the vertical underground high-pressure lined gas storage facility according to any one of claims 1 to 9, wherein the vertical underground high-pressure lined gas storage facility comprises: Multiple gas storage chambers are arranged at intervals and at the same height. The gas storage chambers are arranged vertically. The burial depth of the gas storage chambers ranges from 100 to 150 meters, the inner diameter of the gas storage chambers ranges from 35 to 50 meters, and the height of the gas storage chambers ranges from 50 to 110 meters. Each gas storage chamber includes a hemispherical arched bottom, a hemispherical arched top, and a circumferential tank wall. The arched bottom, the circumferential tank wall, and the arched top are connected in sequence to form a closed gas storage space. Construction tunnels are provided between two adjacent gas storage caverns to connect them. The construction tunnels include a main tunnel and three branch tunnels. The three branch tunnels are respectively connected to the main tunnel and are respectively located at the top, middle and bottom of the gas storage caverns. A vertical shaft is provided at the top of each of the gas storage chambers.

Images