An underground compressed air energy storage chamber with a series-connected rubber air storage bag

Abstract

The present invention discloses a compressed air energy storage underground cavern with a series of rubber air storage bags, comprising a cavern lining, a series of rubber air storage bags, an isolation wall, and a drainage system. The cavern lining is disposed within the surrounding rock, and a cavern sealing door and an air inlet and outlet pipe are provided on one side of the cavern lining. The air inlet and outlet pipes communicate with the series of rubber air storage bags, which are disposed within the cavern lining. The series of rubber air storage bags are composed of a plurality of rubber bags connected in series along the longitudinal direction of the cavern lining. Each rubber bag is integrally formed, and its upper half is tightly fixed to the wall surface of the cavern lining by a fixing device, while the lower half droops naturally. Adjacent rubber bags are connected by flanges and are provided with an isolation wall. The isolation wall is integrally disposed with the cavern lining along the transverse direction of the cavern lining, and the flange is embedded in the isolation wall. The drainage system is disposed at the bottom of the cavern lining. The compressed air energy storage underground cavern has convenient construction and operation, good installation effect and airtightness, low maintenance and repair costs, and a long operating cycle.

Description

Technical Field

[0001] The present invention relates to the technical field of underground gas storage, and in particular to a compressed air energy storage underground cavern with a series-connected rubber gas storage bag. Background Art

[0002] Compressed air energy storage (CAES), often called an air "power bank," boasts large storage capacity, long storage cycles, and low unit investment, making it considered one of the most promising large-scale energy storage technologies. CAES uses high-pressure air as a medium to store and release energy within the power grid. By rationally regulating energy storage and release, it transforms intermittent energy sources such as wind and photovoltaic power into stable, controllable, and high-quality energy. Underground caverns, serving as storage vessels for high-pressure air, play a crucial role in the operation of CAES power stations. A key issue in their construction is their sealing.

[0003] The invention with application number 202110665113.3 and titled "Integral rubber bladder-sealed compressed air energy storage lined cavern" published on November 18, 2022, discloses an integral rubber bladder-sealed cavern. The compressed air energy storage cavern adopts a structure in which an integral rubber bladder is installed in a reinforced concrete lining combined with a drainage ditch. This invention provides a new idea for the sealing of compressed air energy storage caverns. Flexible materials such as rubber have the advantages of good air tightness, uniform deformation with the lining structure, and effective transfer of load to the surrounding rock. However, the structure of underground gas storage caverns is generally large in volume, ranging from tens of thousands to hundreds of thousands of cubic meters. The matching integral rubber bladder structure will have the characteristics of heavy weight, large volume, difficult transportation, and difficult installation. A one-time molded rubber air storage bag is difficult to realize in the actual construction of compressed air energy storage caverns. The rubber air storage bag formed by splicing and pasting pieces has the disadvantages of many splicing seams, long construction period, unguaranteed construction quality, and unguaranteed glue service life, and there is a risk of air leakage. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a compressed air energy storage underground cavern with a series of rubber air storage bags in response to the shortcomings of the existing technology. The compressed air energy storage underground cavern has convenient construction and operation, good installation effect and good air tightness, low maintenance and repair costs, and a long operating cycle.

[0005] The technical solution adopted by the present invention to solve the above technical problems is: a compressed air energy storage underground cavern with serial rubber air storage bags, including a cavern lining, a serial rubber air storage bag, an isolation wall and a drainage system, the cavern lining is arranged in the surrounding rock, and a cavern sealing door and an air inlet and outlet pipe are provided on one side of the cavern lining, the air inlet and outlet pipes are communicated with the serial rubber air storage bag, the serial rubber air storage bag is arranged in the cavern lining, the serial rubber air storage bag is composed of a plurality of rubber bags connected in series along the longitudinal direction of the cavern lining, each of the rubber bags is integrally formed, the upper half of each rubber bag is tightly fixed to the wall surface of the cavern lining by a fixing device, the lower half of each rubber bag naturally droops, and the adjacent two rubber bags are connected by a flange, and an isolation wall is provided between the adjacent two rubber bags, the isolation wall is integrated with the cavern lining along the transverse direction of the cavern lining, the flange is embedded in the isolation wall, and the drainage system is arranged at the bottom of the cavern lining.

[0006] The working principle of the compressed air energy storage underground cavern with serial rubber air storage bags of the present invention is as follows: under the inflation condition, the serial rubber air storage bags are tightly attached to the wall surface of the cavern lining, and the internal pressure is transmitted to the surrounding rock through the cavern lining. The reaction of the surrounding rock makes the internal and external pressures of the serial rubber air storage bags reach a balance, thereby sealing the compressed air energy storage underground cavern; under the deflation condition, the upper half of each rubber bag is tightly attached to the wall surface of the cavern lining, and the lower half of each rubber bag is separated from the wall surface of the cavern lining and is in a naturally drooping and unconstrained state, thereby ensuring the overall shape of the serial rubber air storage bags and avoiding adhesion, uneven expansion or contraction of the serial rubber air storage bags due to repeated inflation and deflation.

[0007] Under inflation and deflation conditions, the condensed water in the compressed air energy storage underground cavern and the groundwater that has infiltrated into the compressed air energy storage underground cavern can be freely discharged out of the cave through the drainage system, and the overall shape of the series-connected rubber air storage bag remains basically unchanged.

[0008] The compressed air energy storage underground cavern of the present invention adopts a series of rubber air storage bags formed by connecting a plurality of rubber bags in series in sequence. Two adjacent rubber bags are connected by flanges. The upper half of each rubber bag is fixed tightly to the wall surface of the cavern lining by a fixing device, and the lower half hangs naturally. A single rubber bag is light in weight and small in size, and the construction operation is convenient and the installation effect is good. The series rubber air storage bag has few interfaces and good air tightness. In addition, the flange is embedded in the isolation wall, and the isolation wall supports the flange and the side wall of the rubber bag, which can ensure that the rubber bag is evenly stressed and prevent the rubber bag from being torn. It can also avoid the side walls of two adjacent rubber bags from sticking together, prevent uneven expansion of the rubber bag, and ensure the use effect and life of the series rubber air storage bag. The maintenance and repair cost of the compressed air energy storage underground cavern of the present invention is low. If a local leak in the rubber bag is found, the leaking rubber bag can be repaired locally or replaced as a whole. The rubber bag is easy to replace, easy to operate, and low in cost without replacing the entire series rubber air storage bag.

[0009] Each rubber bag is integrally formed and has a good sealing effect, which can avoid the construction quality problems and air leakage problems caused by the splicing of sealing materials in general compressed air energy storage underground caverns.

[0010] The length and number of rubber bladders can be flexibly adjusted based on the dimensions of the compressed gas energy storage underground cavern, while the diameter of the bladders is determined based on the project site's requirements. The size, thickness, and weight of individual rubber bladders should be designed in conjunction with the transport capacity of the vertical / inclined shafts and underground hoisting capabilities during the excavation of the compressed gas energy storage underground cavern. Assuming sufficient hoisting capacity, the larger the individual rubber bladder, the fewer bladders required, resulting in better economics.

[0011] Preferably, the fixing device includes a plurality of embedded steel components and a plurality of strong magnets, the plurality of embedded steel components are respectively welded to the main reinforcement of the cavern lining, the plurality of embedded steel components are respectively embedded in the concrete lining of the cavern lining, the inner surfaces of the plurality of embedded steel components are respectively flush with the wall surface of the cavern lining, the plurality of strong magnets are respectively arranged in the series rubber air storage bag, and each of the strong magnets is magnetically connected to one of the embedded steel components. The fixing device uses a combination of embedded steel components and strong magnets to support and fix the rubber bag, which has a simple structure, does not require holes to be opened in the rubber bag, and does not destroy the integrity and airtightness of the rubber bag. The number, specifications and positions of the embedded steel components and strong magnets can be flexibly adjusted and determined according to the diameter, thickness, weight, etc. of the rubber bag.

[0012] Furthermore, the plurality of embedded steel components are a plurality of embedded steel plates, and the plurality of strong magnets are a plurality of neodymium iron boron magnets. After the embedded steel plates are welded to the main reinforcement of the cavern lining, the embedded steel plates can be tightly fitted to the lining casting formwork during the pouring of the concrete lining of the cavern lining. After pouring is completed, the contact boundary between the embedded steel plates and the concrete lining is trimmed to ensure that the embedded steel plates are flush with the wall surface of the cavern lining, ensuring that no protruding surface will scratch the subsequently installed rubber bladder.

[0013] Preferably, a mounting hole is provided in the middle of the isolation wall, the flange is mounted on the mounting hole, and two adjacent side walls of the rubber bags are respectively provided with ventilation holes communicating with the mounting hole.

[0014] Furthermore, the flange includes a first flange ring, a second flange ring, and a third flange ring. The inner holes of the first, second, and third flange rings are coaxially arranged with the mounting hole and the vent hole. The second flange ring is fixed to the center of the isolation wall. The first and third flange rings are respectively positioned within two adjacent rubber bladders and press against the outer peripheries of the corresponding vent holes. The first, second, and third flange rings are each provided with a plurality of bolt holes corresponding to their axial directions. The first, second, and third flange rings are fixedly connected by a plurality of bolts. The second flange ring secures the flange to the center of the isolation wall, preventing damage to the rubber bladder due to flange movement or rotation. The first, second, and third flange rings, along with the sidewalls of the rubber bladder, are fixed to the center of the isolation wall by a plurality of bolts. This provides a simple structure and convenient construction and operation. The inner holes of the first, second, and third flange rings are designed to allow for the passage of construction personnel and equipment.

[0015] Preferably, the surface of the isolation wall is transitionally connected to the arc surface of the wall of the inner lining of the cave to prevent the rubber bag from being damaged by stress concentration.

[0016] Preferably, the drainage system includes a drainage channel and a plurality of water collection wells. The drainage channel is arranged along the longitudinal length of the cavern lining, and the plurality of water collection wells are arranged at intervals along the longitudinal direction of the bottom of the cavern lining. A water collection well is provided under each of the rubber bags, and the plurality of water collection wells are respectively connected to the drainage channel.

[0017] Preferably, each rubber bladder is integrally molded at the factory without any splicing. Upon leaving the factory, it undergoes an airtightness quality inspection. Once qualified, it is transported to the construction site of the compressed gas energy storage underground cavern for installation. After installation, the rubber bladders can also be individually inspected for quality, facilitating both quality inspection and construction quality control.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1) The compressed air energy storage underground cavern with a series-connected rubber air storage bag of the present invention uses a series-connected rubber air storage bag composed of multiple rubber bags connected in series. Each rubber bag is lightweight and compact, easy to construct and operate, and has a good installation effect. The series-connected rubber air storage bag has a small number of interfaces and good airtightness. In addition, the flange is embedded in the isolation wall, which supports the flange and the side wall of the rubber bag, ensuring that the rubber bag is evenly stressed and prevents the rubber bag from tearing. It also avoids the side walls of two adjacent rubber bags from sticking together, preventing uneven expansion of the rubber bag, and ensuring the use effect and life of the series-connected rubber air storage bag.

[0020] 2) The maintenance and repair costs of the compressed air energy storage underground cavern of the present invention are low. If a local leak in the rubber bag is found, the leaking rubber bag can be repaired locally or replaced as a whole. The rubber bag is easy to replace, easy to operate, and low in cost, without having to replace the entire series-connected rubber air storage bag.

[0021] 3) During the operation of the compressed air energy storage underground cavern of the present invention, the serially connected rubber air storage bags can be effectively supported during the cyclic inflation and deflation process, thereby avoiding uneven deformation of the serially connected rubber air storage bags during the cyclic inflation and deflation operation, and avoiding local folding of the rubber bags resulting in weak points due to deflation, and further avoiding contact and adhesion between the side walls of the rubber bags under deflation conditions, thereby ensuring the operation cycle of the compressed air energy storage underground cavern. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the longitudinal section of the compressed gas energy storage underground cavern in the embodiment;

[0023] Figure 2 Schematic diagram of the cross section of the compressed gas energy storage underground cavern in the embodiment;

[0024] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0025] Figure 4 for Figure 2 Enlarged view of point B in the middle;

[0026] Figure 5 Schematic diagram of longitudinal sections of the first flange ring, the second flange ring and the third flange ring in the embodiment;

[0027] Figure 6 is a front view schematic diagram of the first flange ring in the embodiment;

[0028] Figure 7 is a longitudinal sectional perspective view of the first flange ring in the embodiment;

[0029] Figure 8is a longitudinal sectional perspective view of the second flange ring in the embodiment;

[0030] Figure 9 Schematic diagram of the connection between the flange and the rubber bag in the embodiment;

[0031] The specific reference numerals in the figures are as follows:

[0032] 1-cave lining, 11-cave sealing door, 12-inlet and outlet pipes, 2-rubber bag, 21-vent, 3-isolation wall, 31-mounting hole, 4-fixing device, 41-embedded steel member, 42-strong magnet, 5-flange, 51-first flange ring, 52-second flange ring, 53-third flange ring, 54-inner hole, 55-bolt hole, 56-bolt, 61-drainage channel, 62-water collection well. DETAILED DESCRIPTION

[0033] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments. Any unrestricted structure or component in the present invention adopts conventional techniques in the art.

[0034] The compressed air energy storage underground cavern with a series of rubber air storage bags in the embodiment, such as Figures 1 to 4 As shown, it includes a cavern lining 1, a series of rubber air storage bags, an isolation wall 3 and a drainage system. The cavern lining 1 is set in the surrounding rock (not shown in the figure). A cavern sealing door 11 and an air inlet and outlet pipe 12 are provided on one side of the cavern lining 1. The air inlet and outlet pipe 12 are communicated with the series of rubber air storage bags. The series of rubber air storage bags are set in the cavern lining 1. The series of rubber air storage bags is composed of four rubber bags 2 connected in series along the longitudinal direction of the cavern lining 1. Each rubber bag 2 is integrally formed. The upper half of each rubber bag 2 is tightly fixed to the wall of the cavern lining 1 by a fixing device 4. The lower half of each rubber bag 2 droops naturally. The two adjacent rubber bags 2 They are connected by flanges 5, and an isolation wall 3 is provided between two adjacent rubber bags 2. The isolation wall 3 is integrated with the cave lining 1 along the transverse direction of the cave lining 1. The surface of the isolation wall 3 is transitionally connected with the arc surface of the wall of the cave lining 1. The flange 5 is embedded in the isolation wall 3. The drainage system is arranged at the bottom of the cave lining 1. The drainage system includes a drainage channel 61 and 4 water collection wells 62. The drainage channel 61 is arranged along the longitudinal length of the cave lining 1, and the 4 water collection wells 62 are arranged at intervals along the longitudinal direction of the bottom of the cave lining 1. A water collection well 62 is provided under each rubber bag 2, and the 4 water collection wells 62 are respectively connected to the drainage channel 61.

[0035] In this embodiment, the fixing device 4 includes several embedded steel components 41 and several strong magnets 42. The several embedded steel components 41 are respectively welded to the main reinforcement (not shown in the figure) of the cavern lining 1, and the several embedded steel components 41 are respectively buried in the concrete lining of the cavern lining 1. The inner surfaces of the several embedded steel components 41 are respectively flush with the wall surface of the cavern lining 1. The several strong magnets 42 are respectively arranged in the serial rubber air storage bags. Each strong magnet 42 is magnetically connected to one embedded steel component 41. Specifically, the several embedded steel components 41 are several embedded steel plates, and the several strong magnets 42 are several neodymium iron boron magnets.

[0036] In this embodiment, a mounting hole 31 is opened in the middle of the isolation wall 3, the flange 5 is installed in the mounting hole 31, and the side walls of the two adjacent rubber bags 2 are respectively opened with vent holes 21 communicating with the mounting hole 31. Specifically, Figures 5 to 9 As shown, the flange 5 includes a first flange ring 51, a second flange ring 52, and a third flange ring 53. The inner holes 54 of the first flange ring 51, the second flange ring 52, and the third flange ring 53 are coaxially arranged with the mounting hole 31 and the vent hole 21. The second flange ring 52 is fixed to the middle part of the isolation wall 3. The first flange ring 51 and the third flange ring 53 have the same structure. The first flange ring 51 and the third flange ring 53 are respectively arranged in two adjacent rubber bags 2 and press the outer periphery of the corresponding vent hole 21. A plurality of bolt holes 55 are respectively opened in the axial direction of the first flange ring 51, the second flange ring 52, and the third flange ring 53 are fixedly connected by a plurality of bolts 56.

[0037] During the construction of the compressed air energy storage underground cavern, after the embedded steel plate is welded to the main reinforcement of the cavern lining 1, the embedded steel plate can be tightly fitted to the lining casting template (not shown) during the pouring of the concrete lining of the cavern lining 1. After pouring, the contact boundary between the embedded steel plate and the concrete lining is trimmed to align the embedded steel plate with the wall surface of the cavern lining 1, ensuring that no protruding surface will scratch the subsequently installed rubber bladder 2. The wall surface of the cavern lining 1 should be smooth and flat, without sharp protrusions or edges. If necessary, the friction between the cavern lining 1 and the series-connected rubber air storage bladder can be reduced by applying lubricant or laying geotextiles.

[0038] The isolation wall 3 can be re-tied and cast using the steel bars reserved during the construction of the cavern lining 1, reducing the difficulty of laying the lining formwork and pouring. The second flange ring 52 can be connected to the isolation wall 3 using a variety of known methods. Each rubber bladder 2 is factory-molded as a single piece without any splicing. Upon shipment, it undergoes an airtightness quality inspection. After passing the inspection, it is transported to the construction site of the compressed gas energy storage underground cavern and then transported individually to the cavern lining 1. A temporary support structure (not shown) is used to prop up the rubber bladder 2, ensuring that its upper half is aligned with the wall of the cavern lining 1. Strong magnets 42 are then placed inside the rubber bladder 2, magnetically connecting each strong magnet 42 to a pre-embedded steel member 41.

[0039] After all the rubber bags 2 in the cavern lining 1 are installed, the two adjacent rubber bags 2 are connected through the flange 5, and then each rubber bag 2 and the quality of its connection with the flange 5 are inspected one by one to ensure that there is no folding, adhesion, local protrusion or damage on the surface of each rubber bag 2. Then, compressed air can be introduced into the serial rubber air storage bag through the air inlet and outlet pipes 12, and a high-pressure air tightness test can be carried out under the actual operating conditions of the compressed air energy storage underground cavern.

[0040] During inflation, the series-connected rubber airbags cling tightly to the wall of the cavern lining 1, transferring internal pressure through the cavern lining 1 to the surrounding rock. The reaction of the surrounding rock balances the internal and external pressures of the series-connected rubber airbags, sealing the compressed air energy storage underground cavern. During deflation, the upper half of each rubber bag 2 clings tightly to the wall of the cavern lining 1, while the lower half of each rubber bag 2 detaches from the wall of the cavern lining 1 and is in a naturally drooping, unconstrained state, maintaining the overall shape of the series-connected rubber airbags and preventing adhesion, uneven expansion, or contraction of the series-connected rubber airbags due to repeated inflation and deflation. During both inflation and deflation, condensed water within the compressed air energy storage underground cavern and groundwater that has infiltrated the cavern can freely drain out of the cavern through the drainage system, while the overall shape of the series-connected rubber airbags remains essentially unchanged.

[0041] When the interior of the compressed air energy storage underground cavern is in a standard atmospheric pressure state for a long time, the rubber between the fixing devices 4 may produce a certain degree of bending deformation under the action of gravity, resulting in a gap between the rubber and the wall surface of the cavern lining 1. To avoid this phenomenon, under normal operating conditions, the air pressure inside the cavern should be kept higher than the air pressure outside the cavern as much as possible, or the low air pressure state in the cavern should be shortened, and the use of fixing devices 4 should be increased during the construction of the compressed air energy storage underground cavern to shorten the distance between the fixing devices 4 as much as possible.

Claims

1. A compressed air energy storage underground cavern with a series of rubber air storage bags, characterized in that: The utility model comprises a cavern lining, a serial rubber air storage bag, an isolation wall and a drainage system, wherein the cavern lining is arranged in the surrounding rock, a cavern sealing door and an air inlet and outlet pipe are provided on one side of the cavern lining, the air inlet and outlet pipes are communicated with the serial rubber air storage bag, the serial rubber air storage bag is arranged in the cavern lining, and the serial rubber air storage bag is composed of a plurality of rubber bags connected in series in the longitudinal direction of the cavern lining, each of the rubber bags is integrally formed, the upper half of each rubber bag is tightly fixed to the wall surface of the cavern lining by a fixing device, the lower half of each rubber bag droops naturally, and the adjacent two rubber bags are connected by a flange. An isolation wall is provided between the two parts, and the isolation wall is integrally arranged with the cavern lining along the transverse direction of the cavern lining. The flange is embedded and installed in the isolation wall. The drainage system is arranged at the bottom of the cavern lining. The fixing device includes a plurality of embedded steel components and a plurality of strong magnets. The plurality of embedded steel components are respectively welded to the main reinforcement of the cavern lining, and the plurality of embedded steel components are respectively embedded in the concrete lining of the cavern lining. The inner surfaces of the plurality of embedded steel components are respectively flush with the wall surface of the cavern lining, and the plurality of strong magnets are respectively arranged in the serial rubber air storage bags, and each of the strong magnets is magnetically connected to one of the embedded steel components.

2. The compressed air energy storage underground cavern with a series-connected rubber air storage bag according to claim 1, characterized in that: The plurality of embedded steel components are a plurality of embedded steel plates, and the plurality of strong magnets are a plurality of neodymium iron boron magnets.

3. The compressed air energy storage underground cavern with a series-connected rubber air storage bag according to claim 1, characterized in that: A mounting hole is provided in the middle of the isolation wall, the flange is mounted on the mounting hole, and two adjacent side walls of the rubber bags are respectively provided with ventilation holes communicating with the mounting hole.

4. The compressed air energy storage underground cavern with a series-connected rubber air storage bag according to claim 3, characterized in that: The flange includes a first flange ring, a second flange ring and a third flange ring. The inner holes of the first flange ring, the second flange ring and the third flange ring are coaxially arranged with the mounting hole and the vent hole. The second flange ring is fixed to the middle of the isolation wall. The first flange ring and the third flange ring are respectively arranged in two adjacent rubber bags and press the outer periphery of the corresponding vent hole. The first flange ring, the second flange ring and the third flange ring are respectively provided with a plurality of bolt holes in the axial direction. The first flange ring, the second flange ring and the third flange ring are fixedly connected by a plurality of bolts.

5. The compressed air energy storage underground cavern with a series-connected rubber air storage bag according to claim 1, characterized in that: The surface of the isolation wall is transitionally connected to the arc surface of the wall of the cave lining.

6. The compressed air energy storage underground cavern with a series-connected rubber air storage bag according to claim 1, characterized in that: The drainage system includes a drainage channel and multiple water collection wells. The drainage channel is arranged along the longitudinal length of the cave lining. The multiple water collection wells are arranged at intervals along the longitudinal direction of the bottom of the cave lining. A water collection well is provided under each rubber bag. The multiple water collection wells are respectively connected to the drainage channel.

7. The compressed air energy storage underground cavern with series-connected rubber air storage bags according to claim 1, characterized in that: Each of the rubber bladders is integrally formed without any splicing at the factory.

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