Series-parallel integral flexible sealed coal mine tunnel compressed gas energy storage cavern group structure

Abstract

The present invention discloses a series-parallel integral flexible sealed coal mine tunnel compressed air energy storage cavern group structure, comprising: a reinforced concrete lining cast on the inner wall of a single coal mine tunnel and a plurality of prefabricated integral rubber flexible air storage bags arranged in the cavity of the reinforced concrete lining, wherein the plurality of prefabricated integral rubber flexible air storage bags are connected in series to form a single tunnel air storage reservoir, and the single tunnel air storage reservoirs established in the same mode are connected in parallel to form a coal mine tunnel compressed air energy storage cavern group; the present invention not only improves the scale, efficiency and economy of comprehensive utilization of compressed air energy storage in the underground space of Guantui Coal Mine, but also ensures the stability and safety of the gas storage system through reasonable layout and structural design, and provides strong support for the energy management and emergency response of the Guantui Coal Mine energy storage power station.

Description

Technical Field

[0001] The present invention relates to the technical field of underground energy storage, and in particular to a series-parallel integral flexible sealed coal mine tunnel compressed gas energy storage cavern group structure. Background Art

[0002] At present, the rapid development of new energy has put forward an urgent demand for efficient large-scale energy storage. Compressed air energy storage is a safe large-scale physical energy storage technology with the advantages of relatively low construction cost, long energy storage life and environmental protection.

[0003] Compressed air energy storage technology uses air compression and release as a medium for energy storage, achieving electricity storage during low-load periods of the power grid and power generation during peak periods. With the rational regulation of energy storage and release, intermittent new energy sources such as wind power and photovoltaic power can be transformed into stable and controllable high-quality energy. Compressed air energy storage requires a large-capacity gas storage space. Underground space storage is the first choice, and the sealing of high-pressure gas storage is the key. However, coal mine tunnels are characterized by small spaces and long lengths, which poses challenges to the construction of sealing materials. The traditional compressed air energy storage lined cavern design has the following defects:

[0004] 1) In traditional compressed air energy storage systems, steel plates are often used as sealing layers (polymer plates have only recently been conceptually proposed) to ensure the sealed storage of high-pressure air. Steel plate sealing layers offer excellent sealing performance and high strength, and are commonly used to seal large, artificially excavated hard rock underground storage spaces. However, steel plate sealing layers are expensive, and the yield deformation of steel is very small (only 0.2%), making it difficult to adapt to the deformation of the surrounding rock of high-pressure gas storage, which may lead to the risk of sealing layer failure. Polymer plate sealing layers as gas storage sealing layers are still in the exploratory stage and have not yet been applied in practical projects. In particular, in the confined and complex environment of coal mine underground spaces, the technical approach of sealing gas storage with steel plates or polymer plates is difficult to implement. This is because the limited underground space makes it extremely difficult to transport large steel plates or polymer sealing materials to the work site. Furthermore, on-site cutting and welding of steel plates, or welding and installing polymer materials, not only requires stringent technical requirements, but also significantly increases the difficulty and cost of construction due to the limited working space.

[0005] 2) In the integration of compressed air storage rubber bladders with reinforced concrete linings, while geotextiles have traditionally been used to address the issue of proper fit between the two, their effectiveness is unsatisfactory. The geotextiles have difficulty adapting to the uneven surface of the lining, potentially causing the bladders to rupture due to uneven force. Therefore, the geotextiles' potential for rupture in practical applications demonstrates a structural design flaw, necessitating the search for a more effective solution.

[0006] 3) If only one large sealing unit (i.e., a single large air bag) is deployed in a single coal mine tunnel, there are problems such as difficulty locating the leak point, high maintenance and replacement costs, and inconvenient transportation and installation in narrow coal mine tunnels. Specifically, once a leak occurs in a large air bag, due to its large size and complex structure, it is difficult to quickly determine the leak point, which increases the difficulty of repair. At the same time, the cost of repairing or replacing a large air bag is relatively high, including not only material costs but also potential additional losses due to downtime. In addition, the transportation and installation of large air bags in narrow coal mine tunnels are complex and subject to space constraints, further increasing the difficulty of construction and project time. These issues together constitute the main technical challenges faced when installing a single large sealing unit in a single tunnel, involving cost, safety, and ease of operation, and urgently need to be resolved through technological innovation and improvement.

[0007] 4) The economic benefits of underground gas storage in coal mines are closely related to their gas storage capacity. Since underground coal mines are mostly distributed in the form of tunnels, if the capacity of a single underground gas storage chamber is too small, it will be difficult to cover its construction and operating costs, resulting in low economic benefits. Therefore, to maximize economic benefits, underground gas storage in coal mines needs to reach a certain gas storage capacity. This requires considering the distribution characteristics of underground coal mines, rationally planning the scale and layout of gas storage, and achieving the coordinated and efficient operation of multiple tunnel gas storages to ensure their economic and practicality.

[0008] 5) The existing invention only designs a relatively common drainage ditch, which is excavated at the bottom of the compressed gas energy storage liner cavern. Its function is to collect and drain the groundwater in the cavern to maintain the dryness and sealing of the cavern. However, there is no detailed description of how to pump water out of the drainage ditch. Summary of the Invention

[0009] To solve the problems existing in the prior art, the purpose of the present invention is to provide a series-parallel integral flexible sealed coal mine tunnel compressed gas energy storage cavern group structure. The present invention not only improves the energy storage efficiency, but also ensures the stability and safety of the gas storage system through reasonable layout and structural design, providing strong support for energy management and emergency response of closed coal mine energy storage power stations.

[0010] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a series-parallel integral flexible sealed coal mine tunnel compressed air energy storage cavern group structure, including: a reinforced concrete lining cast on the inner wall of a single coal mine tunnel and a plurality of prefabricated integral rubber flexible air storage bags arranged in the cavity of the reinforced concrete lining. The plurality of prefabricated integral rubber flexible air storage bags are connected in series to form a single tunnel air storage reservoir, and the single tunnel air storage reservoirs established in the same mode are connected in parallel to form a coal mine tunnel compressed air energy storage cavern group.

[0011] As a further improvement of the present invention, the single-lane serial rubber flexible air storage bag includes a plurality of rubber air bags connected in series in sequence, and the adjacent two rubber air bags are connected by a sleeve and a rolled threaded O-ring, and an intelligent pressure monitoring and wireless control system is installed between the adjacent two rubber air bags; a rear plug is provided at one end of the serial rubber flexible air storage bag, and an entrance closed door is provided at the other end, a front plug is installed on the entrance closed door, and two pipe holes are preset on the entrance closed door, and the two pipe holes are used to lead out the outlet pipe and the inlet pipe connected to the rubber air bag, and the outlet pipe and the inlet pipe are provided with a main control airflow regulating valve.

[0012] As a further improvement of the present invention, the reinforced concrete lining and the surface of the rear plug are both sprayed with ethylene-vinyl acetate copolymer EVA material.

[0013] As a further improvement of the present invention, the compressed air energy storage cavern group uses wind power generation, solar energy and power transmission structure to electrically drive the compressor to compress the air to a high-pressure state, and stores the heat generated during the compression process through a heat exchange system; the high-pressure gas compressed to a high-pressure state is introduced into the rubber airbag through the air intake pipe, so that the last rubber airbag is completely fitted with the rear plug and the reinforced concrete lining and transmitted to the surrounding rock of the coal mine tunnel. After the first rubber airbag is inflated, it presses against the entrance closed door, and the entrance closed door transmits the force to the surrounding rock under the action of the front plug.

[0014] As a further improvement of the present invention, the main air valve is opened through the intelligent pressure monitoring and wireless control system to release the compressed air in the rubber airbag; the compressed air is discharged through the air outlet pipe, absorbs the previously stored heat through the heat exchange system, and then drives the expander for power generation, and transmits the electricity to residential buildings and factories, thereby realizing the conversion process from energy storage to power generation.

[0015] As a further improvement of the present invention, when the compressed air is discharged through the air outlet pipe, the series-connected rubber flexible air storage bag begins to shrink, and the groundwater accumulated between the reinforced concrete lining and the series-connected rubber flexible air storage bag is collected into the groundwater reservoir through the sloped drainage ditch excavated at the bottom of the coal mine tunnel; when the groundwater reservoir accumulates to a certain extent, the groundwater is pumped out of the groundwater reservoir using the outlet pipe using pumping equipment.

[0016] As a further improvement of the present invention, during the storage and release process of compressed air energy storage, a parallel compressor system is used to inflate multiple coal mine tunnel gas storage tanks; during operation, if an abnormality is detected in the series-type rubber flexible air storage bag in a certain tunnel, it is discovered in time through the reading of the pressure gauge, and the operation of the tunnel is immediately stopped and repaired through the intelligent pressure monitoring and wireless control system.

[0017] As a further improvement of the present invention, during the inflation process of the compressed air energy storage system, the reading of the barometer is closely monitored. If it is found that the barometer of a certain lane gas storage reservoir shows an abnormality, the remote control system is used to close the valve of the air inlet pipe of the air storage reservoir to cut off the inflow of high-pressure gas; then, the main control air flow regulating valve is opened to allow the high-pressure air of the abnormal air storage reservoir to flow back, and the air inlet pipe valves of other normal lane gas storage reservoirs are opened, and the high-pressure air of the abnormal air storage reservoir is used to inflate other normal air storage reservoirs, thereby improving the utilization rate of high-pressure air and the energy storage efficiency of the entire system. As a further improvement of the present invention, during the inflation process of the compressed air energy storage system, the reading of the barometer is closely monitored. If it is found that the barometer shows an abnormality, the remote control system is used to close the valve of the air inlet pipe to cut off the inflow of high-pressure gas; then, the compressed gas is discharged and utilized through the outlet pipe, and at the same time, the main control air flow regulating valve is opened to gradually release the gas in all rubber air bags.

[0018] This invention aims to achieve large-scale, long-term, continuous compressed air energy storage in underground coal mines. Its core lies in the innovative use of multiple prefabricated, integral rubber air bags of moderate capacity, arranged in series within a single roadway to form independent air storage reservoirs (units). Subsequently, by connecting these individual roadway air storage reservoirs in parallel, a cluster of air storage chambers is formed, thereby achieving efficient, large-scale energy storage in underground coal mines. This invention improves compressed air energy storage technology at two levels: the cavern cluster level and the individual roadway air storage level. This approach not only improves energy storage efficiency but also, through rational layout and structural design, ensures the stability and safety of the air storage system, providing strong support for energy management and emergency response at closed coal mine energy storage power stations.

[0019] The beneficial effects of the present invention are:

[0020] 1. This invention utilizes a monolithic, flexible rubber airbag sealing layer, replacing traditional steel or polymer sheet sealing layers. The high strength and toughness (good deformation capacity) of the rubber airbag material enable it to better coordinate with the deformation of the coal mine gas storage reservoir, while also facilitating transportation and installation, particularly within the confined space of underground coal mines. Its excellent sealing performance helps improve energy storage efficiency. The rubber airbag is highly adaptable to environmental conditions and resists corrosion and wear. Furthermore, in terms of safety, it can release pressure by deforming when subjected to excessive pressure, reducing the risk of explosion.

[0021] 2. This invention utilizes ethylene-vinyl acetate copolymer (EVA) as the second sealing layer in the compressed air energy storage system. It is sprayed onto the reinforced concrete lining. Its primary advantages lie in its excellent airtightness and waterproof properties, which are crucial for maintaining the airtightness and stability of the storage chamber. Furthermore, EVA ensures that the rubber bladder adheres tightly to the lining surface when inflated, especially when the lining surface is uneven or cracked, and reduces moisture penetration between the rubber bladder and the lining. EVA is easy to apply and can be applied using existing sprayed concrete machinery, effectively reducing construction costs and complexity. As an economical and efficient solution, EVA offers significant cost-effectiveness, helping to reduce the total project investment. Furthermore, EVA is highly adaptable, adapting to various geological conditions and chamber shapes, while also offering excellent durability and withstanding long-term environmental impact. While enhancing the airtightness of the flexible sealing layer, EVA also further improves the sealing margin of the gas storage facility.

[0022] 3. The present invention solves the problem of leakage monitoring in coal mine tunnel gas storage by using multiple prefabricated integral rubber airbags connected in series. The length of each airbag is controlled between 10 and 20 meters, and the thickness is about 2 mm. It is easy to fold and transport and to be connected in series through pressure pipes on site to fully utilize the tunnel space and form a larger gas storage volume. This design avoids the difficulties of on-site transportation, cutting, welding / fusion and installation of sealing layers. Each airbag is equipped with a wireless electronically controlled pressure valve for individual control, ensuring that when a leak occurs, the specific leaking unit can be accurately monitored and located, facilitating timely maintenance and replacement without affecting the operation of the entire gas storage system.

[0023] 4. The present invention aims to form a gas storage cavern group by connecting multiple coal mine roadway gas storage reservoirs in parallel, thereby increasing the total energy storage and economic benefits of the compressed air energy storage caverns in the underground space of coal mines. In the underground space of coal mines, a specific roadway is usually selected as a gas storage reservoir, but due to the low energy storage capacity and efficiency, this approach is often not economically feasible. The present invention proposes to connect multiple roadway gas storage reservoirs in parallel to form a gas storage cavern group, so as to significantly increase the total gas storage capacity, thereby increasing the total energy storage and economic benefits. It can be seen that the present invention forms a compressed air energy storage cavern group composed of multiple roadways through reasonable arrangement. These cavern groups can realize the succession of inflation-gas storage-gas discharge and power generation when working, so that the underground air compressed air energy storage power station of Guantui Coal Mine can achieve large-capacity, long-term and continuous operation, improve work efficiency and achieve economic benefits. In the cavern group, each individual gas storage is connected in parallel, and is independently controlled without affecting each other. At the same time, during the continuous work process, a gap is left for inflation or maintenance for the cavern group that is not currently connected to the power grid.

[0024] 5. To ensure the normal operation of the gas storage reservoir, the present invention has specially designed a sloped drainage ditch, which is located directly below the gas storage reservoir in the lining layer, and a cover with drip holes is installed above the drainage ditch. This design uses gravity to more effectively guide the water that has seeped into the gas storage reservoir into the water collection well. Compared with the traditional horizontal drainage ditch, the sloped drainage ditch significantly improves the drainage efficiency. The setting of the water collection well further enhances the drainage capacity of the gas storage reservoir and ensures the normal operation of the mine. In addition, by equipping it with a water pump, the water in the water collection well can be pumped out of the coal mine, further preventing moisture accumulation. During the deflation process, the air bag is separated from the concrete lining and laid flat in the tunnel, leaving space for draining the groundwater between the lining and the air bag. The sloped drainage ditch excavated at the bottom of the tunnel and the designed water collection well can pump out the groundwater through a water pump when it accumulates to a certain level, thereby effectively preventing groundwater from interfering with the normal operation of the gas storage reservoir.

[0025] 6. The present invention incorporates a wedge-shaped plug design within the gas storage reservoir's sealing structure. This structure, when subjected to the outward pressure of the airbag, can become increasingly embedded in the coal seam, thereby providing a more stable sealing effect. The advantage of the wedge-shaped plug design lies in its self-tightening function, which enhances the reliability of the seal. Furthermore, the present invention incorporates a high-pressure sealing door to facilitate maintenance work, including partial welding reinforcement or complete replacement of leaking airbags. This design not only improves the convenience and efficiency of maintenance but also ensures the safe operation and maintenance of the gas storage reservoir.

[0026] 7. In designing the compressed air energy storage system, the present invention pays special attention to the connection method between the airbags and proposes a connection technology - rolled thread O-ring connection. This connection method uses an O-ring with a Shore hardness of 90-95. O-rings in this hardness range have been proven to be able to withstand a pressure of 16-32MPa, which is fully suitable for the pressure range of compressed air energy storage. Through this design, not only the sealing and stability of the airbag connection are ensured, but also the reliability and efficiency of the entire energy storage system are improved. This rolled thread O-ring connection method, due to its excellent pressure resistance and simple installation process, provides an effective solution for the development of compressed air energy storage technology.

[0027] 8. The present invention proposes for the first time the concept of a compressed gas energy storage cavern group in the underground space of a Guantui coal mine. The core of the invention is to connect the gas storage caverns in each tunnel in parallel through the inlet and outlet pressure pipes to form an efficient energy storage system. In terms of specific technical implementation, taking three caverns as an example, a set of air compressors and generator sets are used to lead out three interfaces that are connected to the air intake and exhaust pipes of each cavern to achieve parallel connection. In terms of workflow, the compressor will inflate each cavern in turn. Although the inflation process may take a long time due to the large number of caverns, once a cavern is completed and reaches the predetermined gas storage time, it can start to deflate and generate electricity. This process can be cyclical to ensure a continuous supply of energy. If a problem is found in a cavern during operation, its work can be stopped immediately and repaired without affecting the operation of the entire cavern group. The entire workflow can be managed in an information-based manner with the help of artificial intelligence technology to optimize scheduling and improve system efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the overall structure of an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of the structure of serially connected rubber flexible air storage bags in parallel according to an embodiment of the present invention;

[0030] Figure 3 Schematic diagram of the structure of the entrance closed door in an embodiment of the present invention;

[0031] Figure 4 Schematic diagram of the principles of gas storage and release in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0033] Example

[0034] like Figures 1-4 Figure 1 shows a series-parallel, integrally flexible, sealed coal mine tunnel compressed gas energy storage chamber cluster structure. Specifically, abandoned coal mine tunnels are used to construct a series-parallel, integrally flexible, sealed, lining coal mine tunnel compressed gas energy storage chamber cluster. This approach transforms multiple tunnels into gas storage chambers and employs integrally flexible sealing lining technology, such as rubber airbags, to adapt to the spatial and environmental characteristics of underground coal mine tunnels, ensuring the gas storage's sealing and safety. This solution is not only cost-effective, reducing construction and maintenance costs, but also enabling the large-scale reuse of abandoned mines. Furthermore, the series-parallel configuration provides flexibility in energy storage scale, enhancing system reliability and robustness. This innovative CAES technology approach provides an effective solution for the efficient and large-scale utilization of renewable energy and grid stability, and is of great significance for promoting energy structure transformation and sustainable development.

[0035] To construct a compressed air energy storage system, a reinforced concrete lining 20 is first cast on the inner wall of the coal mine tunnel, and a rear plug 8 is installed. Subsequently, ethylene-vinyl acetate copolymer (EVA) material 19 is sprayed onto the surfaces of the reinforced concrete lining 20 and the rear plug 8 to enhance airtightness and waterproofing. A prefabricated airbag is placed before the rear plug 8, and two adjacent rubber airbags are tightly connected using a sleeve and a rolled threaded O-ring to form a prefabricated series of rubber flexible air storage bags 10, ensuring high airtightness between components. Using three flexible rubber airbags as an example, the number of airbags is adjusted appropriately based on the tunnel length. An intelligent pressure monitoring and wireless control system 11 is installed between the airbags to remotely control valve closures in response to pressure anomalies, enabling leak detection and facilitating maintenance. After the prefabricated series of rubber flexible air storage bags 10 are installed, an entry closure door 12 is positioned at a predetermined position on the last flexible rubber airbag to ensure a perfect fit during inflation. Front plugs 9 are then installed above and below the entry closure door 12. Finally, the outgoing air pipe 16 and the inlet air pipe 15 are led out from the last flexible rubber airbag. The two pipes pass through the two preset pipe holes 12001 on the inlet closed door 12. In addition, each pipe is equipped with a main control airflow regulating valve 13 to control the operation of a single flexible rubber airbag to ensure the safety and efficiency of the entire energy storage system.

[0036] After the device is installed, the system begins using compressed air energy storage. When wind power generation 1, solar energy 2, and power transmission structure 3 are low-cost, an electrically driven compressor 17 compresses air to a high pressure. The heat generated during the compression process is stored via a heat exchange and heat storage system 21. The high-pressure gas is then introduced into the flexible rubber airbag via an intake duct 15, causing it to expand. Ultimately, the last flexible rubber airbag will completely adhere to the rear plug 8 and reinforced concrete lining 20, which has been treated with EVA spraying for a smooth surface and excellent waterproof properties, ensuring that the expansion force of the flexible rubber airbag can be transmitted through the reinforced concrete lining 20 to the surrounding rock 22. After expansion, the frontmost flexible rubber airbag presses against the inlet sealing door 12. Under the action of the front plug 9, the inlet sealing door 12 transmits force to the surrounding rock 22, enhancing its stability and completing the gas storage process. When grid demand is high and electricity costs rise, the intelligent pressure monitoring and wireless control system 11 opens the main air valve, releasing the compressed air from the flexible rubber airbag. The compressed air is discharged through the outlet pipe 16, passes through the heat exchange and storage system 21, absorbs the previously stored heat, and then drives the expander 18 to generate electricity, which is then transmitted to users such as residential buildings 4 and factories 5, thus completing the conversion process from energy storage to power generation. Subsequently, as the prefabricated series-connected rubber flexible air storage bags 10 begin to shrink, the groundwater accumulated between the reinforced concrete lining 20 and the prefabricated series-connected rubber flexible air storage bags 10 is collected into the groundwater reservoir 14 through the sloped drainage ditch 23 excavated at the bottom of the coal mine roadway. When the groundwater reservoir 14 accumulates to a certain level, the groundwater is pumped out of the groundwater reservoir 14 using the pumping equipment 7 and the outlet pipe 6.

[0037] During the entire compressed air energy storage system's inflation and deflation power generation operation process, the various tunnel gas storage reservoirs are connected in parallel through pressure pipes, and multiple coal mine tunnel gas storage reservoirs are connected and cyclically inflated and deflated for power generation through compressors 17 and expanders 18. Although the inflation process may be time-consuming due to the large number of tunnels, once a tunnel is completed and reaches the predetermined gas storage time, deflation power generation can be started. This cycle ensures a continuous supply of energy. During operation, if an abnormality is detected in the prefabricated serial rubber flexible air storage bag 10 in a tunnel, it can be discovered in time through the pressure gauge reading, and the intelligent pressure monitoring and wireless control system 11 can be used to immediately stop the operation of the tunnel for maintenance. This design ensures the independent operation of each coal mine tunnel, avoids the problem of a single tunnel affecting the operation of the entire energy storage system, and thus improves the reliability and flexibility of the entire compressed air energy storage system.

[0038] During the operation of the compressed air energy storage system, the pressure gauge reading is closely monitored to ensure the normal operation of the system. Once the pressure gauge shows an abnormality, immediate action is taken to close the air valve of the air inlet pipe using the remote control system to cut off the inflow of high-pressure gas. Subsequently, the compressed gas is discharged through the outlet pipe and utilized, and at the same time, the main control air flow regulating valve 13 is opened to gradually vent the gas in all air bags. While ensuring safety, the staff enters the coal mine tunnel through the high-pressure door to replace the damaged air bag. After the replacement is completed, the new air bag will be taken out through the high-pressure door and installed in place to restore the normal operation of the energy storage system. This process not only ensures the safety of the system, but also ensures the efficiency of maintenance work, thereby minimizing system downtime and maintaining the stability and reliability of the compressed air energy storage system.

[0039] This embodiment innovatively proposes the concept of a series-parallel integral flexible sealed lined coal mine tunnel compressed gas energy storage cavern group. This design significantly improves the utilization rate of coal mine tunnel space. By connecting multiple tunnels in series and parallel, an efficient energy storage system is formed, which not only increases the gas storage capacity but also improves the energy storage efficiency. The entire workflow adopts information management to achieve real-time monitoring and optimized scheduling of the energy storage system, thereby improving the overall efficiency of the system. This management method ensures the maximum utilization of energy, while also providing stable, reliable and large-scale energy storage services for the power grid, supporting the integration of renewable energy and the smooth operation of the power grid. Through this advanced energy storage solution, it can better adapt to fluctuations in energy demand and promote the sustainable management and utilization of energy; specifically, it is reflected in:

[0040] 1. As an alternative to sealing layers, flexible rubber airbags offer excellent sealing performance and environmental adaptability, improving energy storage efficiency while reducing maintenance and construction costs. This material's excellent airtightness, high strength, high toughness (good deformation resistance), and low density allow it to better adapt to the stresses and deformations of high-pressure gas storage, particularly within the confined spaces of underground coal mines. This facilitates transportation and installation, simplifying the construction process. The rubber airbag's ability to release pressure by deforming when subjected to excessive pressure effectively reduces the risk of explosion and improves construction safety. Furthermore, the rubber airbag's resistance to corrosion and wear makes it suitable for a variety of underground environments, ensuring the long-term stability and safety of underground projects.

[0041] 2. This embodiment achieves excellent airtightness and waterproofing by spraying ethylene-vinyl acetate copolymer (EVA) onto the reinforced concrete lining as a secondary sealing layer for the compressed air energy storage system. This is crucial for maintaining the airtightness and stability of the gas storage chamber. EVA's superior properties ensure that the rubber bladder adheres tightly to the lining surface when inflated, effectively reducing moisture penetration, especially in the presence of uneven or cracked surfaces. This enhances the airtightness of the flexible sealing layer, thereby improving the airtightness of the gas storage reservoir. Furthermore, the ease of construction of EVA allows for the use of existing shotcrete machinery, reducing construction costs and complexity and significantly improving efficiency. As a cost-effective solution, EVA offers significant cost-effectiveness, helping to reduce the total project investment. EVA's high adaptability and durability enable it to adapt to various geological conditions while withstanding environmental impacts, providing strong technical support for the long-term and stable operation of the energy storage system.

[0042] 3. This embodiment effectively solves the problem of leakage monitoring in coal mine tunnel gas storage by connecting multiple prefabricated rubber airbags in series. The length of each airbag is controlled at 10 to 20 meters and the thickness is about 2 mm. It is easy to fold and transport and to connect in series through pressure pipes on site to fully utilize the tunnel space to form a larger single tunnel gas storage volume. This design simplifies the on-site construction process, avoids the complexity of transportation, cutting, welding / fusion and installation of sealing layers, and reduces construction costs. Each airbag is equipped with a wireless electronically controlled pressure valve for individual control, ensuring that when a leak occurs, it can be accurately monitored and located at the specific leaking unit, facilitating timely maintenance without affecting the operation of the entire gas storage system, thereby improving gas storage efficiency and safety, while reducing maintenance costs, improving monitoring accuracy and system flexibility, and providing a cost-effective and efficient technical solution for coal mine tunnel gas storage.

[0043] 4. This embodiment significantly improves the total energy storage and economic benefits of underground compressed air energy storage caverns in coal mines by configuring multiple coal mine roadway gas storage reservoirs in parallel. This configuration not only increases the total gas storage capacity, but also improves the energy storage efficiency, enabling the underground compressed air energy storage power station of the closed coal mine to achieve large-capacity, long-term, and continuous operation, thereby improving work efficiency and achieving economic benefits. The parallel cavern group can realize the cycle and continuity of inflation-gas storage-gas discharge power generation during operation. Each single roadway gas storage reservoir maintains independent control and does not affect each other. At the same time, during the continuous operation process, it leaves a gap for inflation or maintenance for the cavern group that is currently not connected to the power grid, optimizes the energy storage system scheduling work procedure, and ensures the energy storage scale. In addition, the use of abandoned coal mine roadways as gas storage reservoirs realizes the reuse of underground space resources in coal mines, provides a path for sustainable development for resource-depleted mines, and promotes the consumption of new energy and the clean and low-carbon transformation of the energy system.

[0044] 5. This embodiment significantly improves the drainage efficiency and operational safety of the gas storage reservoir by designing a sloped drainage ditch and its supporting water collection well and pumping system. The sloped drainage ditch is located directly below the gas storage reservoir in the lining layer, and uses gravity to more effectively guide the infiltrated water to the water collection well, which significantly improves the drainage efficiency compared to the traditional horizontal drainage ditch. The setting of the water collection well further enhances the drainage capacity and ensures the normal operation of the mine. The equipped pump can pump water from the water collection well out of the coal mine to prevent water accumulation. During the deflation process, the air bag is separated from the concrete lining, leaving space for the removal of groundwater between the lining and the air bag. This design not only improves the safety of the gas storage reservoir and reduces maintenance costs, but also reduces construction work volume and costs, providing strong technical support for the stable operation of underground compressed air energy storage mines.

[0045] 6. This embodiment significantly improves the safety and maintenance efficiency of the gas storage plugging structure by adopting a wedge-shaped plug design and a high-pressure sealing door. Under the pressure of the airbag pushing outward, the wedge-shaped plug can be embedded more and more tightly with the coal seam, providing a more stable sealing effect, and its self-tightening function enhances the reliability of the plugging. At the same time, the design of the high-pressure sealing door facilitates maintenance work, including local welding reinforcement or overall replacement of leaking air bags, which improves the convenience and efficiency of maintenance. This design not only ensures the safe operation of the gas storage, but also reduces the maintenance costs caused by plugging failure and reduces the economic losses caused by leakage, thereby improving the economic benefits and operating efficiency of the gas storage.

[0046] 7. This embodiment utilizes rolled threaded O-rings to connect the prefabricated, serially connected rubber flexible air storage bags within the compressed air energy storage system. By using O-rings with a Shore hardness of 90-95, the air bag connection is ensured to be leak-tight and stable. O-rings in this hardness range can withstand pressures of 16-32 MPa, which is consistent with the operating pressure range of compressed air energy storage. This connection method not only improves the reliability and efficiency of the entire energy storage system, but also simplifies installation and reduces maintenance and operating costs.

[0047] 8. This embodiment proposes a concept for a cluster of compressed gas energy storage chambers in underground Guantui coal mines. By connecting the gas storage chambers in each lane in parallel, efficient energy storage is achieved. This system utilizes a set of air compressors and generators, connected to the air intake and exhaust pipes of each chamber through multiple interfaces (three interfaces are provided in this example, using three lanes) to achieve parallel operation. During the workflow, the compressors sequentially inflate each chamber. Once a chamber is fully inflated and reaches the predetermined storage time, it begins to discharge gas and generate electricity. This cyclical process ensures a continuous energy supply. If a chamber experiences a problem, its operation can be immediately stopped and repaired without affecting the operation of the entire chamber cluster, enhancing the system's flexibility and reliability. Leveraging artificial intelligence and information technology, the entire workflow can be managed in an information-based manner, optimizing scheduling and improving system efficiency. This technical solution not only promotes the transformation of energy structure, reduces energy storage costs, and improves return on investment, but also provides strong support for the advancement of energy storage technology and efficient energy utilization by improving energy storage efficiency and technical performance.

[0048] The above-described embodiments merely represent specific implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, and all such variations and improvements fall within the scope of protection of the present invention.

Claims

1. A series-parallel integral flexible sealed coal mine tunnel compressed gas energy storage cavern group structure, characterized in that: include: A reinforced concrete lining is cast on the inner wall of a single coal mine tunnel and a plurality of prefabricated integral rubber flexible air storage bags are arranged in the cavity of the reinforced concrete lining. The plurality of prefabricated integral rubber flexible air storage bags are connected in series to form a single tunnel gas storage reservoir. The single tunnel gas storage reservoirs established in the same mode are connected in parallel to form a coal mine tunnel compressed air energy storage cavern group. The single tunnel series rubber flexible air storage bag includes a plurality of rubber air bags connected in series in sequence. The adjacent two rubber air bags are connected by sleeves and rolled thread O-rings, and the adjacent An intelligent pressure monitoring and wireless control system is installed between the two rubber airbags; a rear plug is provided at one end of the serial rubber flexible air storage bag, and an inlet closed door is provided at the other end, a front plug is installed on the inlet closed door, and two pipe holes are preset on the inlet closed door, and the two pipe holes are used to lead out the air outlet pipe and the air inlet pipe connected to the rubber airbag, and the air outlet pipe and the air inlet pipe are provided with a main control airflow regulating valve; the reinforced concrete lining and the surface of the rear plug are sprayed with ethylene-vinyl acetate copolymer EVA material.

2. The series-parallel integral flexible sealed coal mine tunnel compressed gas energy storage cavern group structure according to claim 1 is characterized in that: The compressed air energy storage cavern group uses wind power generation, solar energy and power transmission structure to electrically drive the compressor to compress the air to a high-pressure state, and stores the heat generated during the compression process through a heat exchange system; the high-pressure gas compressed to a high-pressure state is introduced into the rubber airbag through the air intake pipe, so that the last rubber airbag completely fits the rear plug and the reinforced concrete lining and is transmitted to the surrounding rock of the coal mine tunnel. After the first rubber airbag is inflated, it presses against the entrance closed door, and the entrance closed door transmits the force to the surrounding rock under the action of the front plug.

3. The series-parallel integral flexible sealed coal mine tunnel compressed gas energy storage cavern group structure according to claim 2 is characterized in that: Open the main air valve through the intelligent pressure monitoring and wireless control system to release the compressed air in the rubber airbag; The compressed air is discharged through the outlet pipe, passes through the heat exchange system to absorb the previously stored heat, and then drives the expander to generate electricity, transmitting electricity to residential buildings and factories, thus realizing the conversion process from energy storage to power generation.

4. The series-parallel integral flexible sealed coal mine tunnel compressed gas energy storage cavern group structure according to claim 3 is characterized in that: When the compressed air is discharged through the air outlet pipe, the series-connected rubber flexible air storage bag begins to shrink, and the groundwater accumulated between the reinforced concrete lining and the series-connected rubber flexible air storage bag is collected into the groundwater reservoir through the sloped drainage ditch excavated at the bottom of the coal mine tunnel; when the groundwater reservoir is filled to a preset level, pumping equipment is used to pump the groundwater out of the groundwater reservoir using the outlet pipe.

5. The series-parallel integral flexible sealed coal mine tunnel compressed gas energy storage cavern group structure according to claim 4 is characterized in that: During the storage and release process of compressed air energy storage, a parallel compressor system is used to inflate multiple coal mine tunnel gas storage facilities. During operation, if an abnormality is detected in the series-connected rubber flexible air storage bag in a certain tunnel, it will be discovered in time through the reading of the pressure gauge, and the operation of the tunnel will be immediately stopped and repaired through the intelligent pressure monitoring and wireless control system.

6. The series-parallel integral flexible sealed coal mine tunnel compressed gas energy storage chamber group structure according to claim 4 is characterized in that: During the inflation process of the compressed air energy storage system, the pressure gauge reading is closely monitored. If the pressure gauge of a certain tunnel gas storage reservoir is found to show an abnormality, the remote control system is used to close the valve of the air inlet pipe of the gas storage reservoir to cut off the inflow of high-pressure gas; then, the main control air flow regulating valve is opened to allow the high-pressure air of the abnormal gas storage reservoir to flow back, and the air inlet pipe valves of other normal tunnel gas storage reservoirs are opened, and the high-pressure air of the abnormal gas storage reservoir is used to inflate other normal gas storage reservoirs, thereby improving the utilization rate of high-pressure air and the energy storage efficiency of the entire system.

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