A compressed carbon dioxide energy storage system utilizing abandoned mine resources

Abstract

The utility model relates to the technical field of compressed carbon dioxide energy storage, especially to a kind of compressed carbon dioxide energy storage system for recycling abandoned mine resources, including compressed energy storage subsystem, heat storage and heat exchange subsystem, liquefied gasification subsystem, medium-pressure liquid storage subsystem, expansion energy release subsystem, low-pressure gas storage subsystem.This kind of compressed carbon dioxide energy storage system using abandoned mine resources, for the effective development and utilization of mine resources, adopt capsule type flexible single membrane air warehouse structure, without outer membrane, cable net and air supplement system, can effectively reduce the construction cost and period of system, the device is aimed at widely distributed abandoned mine resources, according to the different regional geological conditions inside mine, using mine has certain pressure capacity and shelter effect, stable temperature environment and other favorable factors, effectively combined with compressed carbon dioxide energy storage system application, that is, realized the secondary development and utilization of abandoned mine resources, and promoted the development of compressed carbon dioxide energy storage technology application.

Description

Technical Field

[0001] This utility model relates to the technical field of compressed carbon dioxide energy storage, and in particular to a compressed carbon dioxide energy storage system for the reuse of abandoned mine resources. Background Technology

[0002] Compressed carbon dioxide (CCCO) energy storage technology is one of the emerging long-term energy storage technologies. The system uses CO2 as the working fluid, achieving liquid storage through compression and liquefaction at room temperature. Current two-phase compressed carbon dioxide energy storage systems require enormous storage space and land area for the low-pressure side gas storage unit. Furthermore, the impact of ultraviolet radiation and weather conditions such as wind, rain, and snow must be considered, resulting in high investment costs. Traditional pressure vessels used for medium- and high-pressure side liquid storage are also too expensive, significantly limiting the application and development of compressed carbon dioxide energy storage systems. Meanwhile, my country has a large number of abandoned mines due to resource depletion or ecological protection. These abandoned mines face the problem of resource waste from direct abandonment or landfill, while also requiring ecological restoration and resource reuse. Underground mine spaces inherently possess a certain pressure-bearing capacity, sheltering effect, and stable temperature environment, making the combination of compressed carbon dioxide energy storage systems with underground mine resources highly valuable. Therefore, a compressed carbon dioxide energy storage system utilizing abandoned mine resources is particularly needed.

[0003] Based on the current compressed carbon dioxide energy storage technology of gas-liquid two-phase storage, the above-ground and underground resources of abandoned mining areas are fully reused. The underground spaces such as vertical shafts and inclined tunnels with certain pressure bearing capacity are sealed and modified to form a large-capacity liquid storage tank to store medium-pressure liquid carbon dioxide. The underground goaf area is transformed into a distributed low-pressure carbon dioxide storage tank using single-layer gas film material. This device realizes the secondary development and reuse of the resources in the current abandoned mining areas, greatly reduces the construction cost of compressed carbon dioxide systems, and avoids the safety hazards caused by a large number of pressure vessels. Utility Model Content

[0004] The purpose of this invention is to provide a compressed carbon dioxide energy storage system that utilizes abandoned mine resources, thereby addressing the challenges posed by the current compressed carbon dioxide energy storage technology based on gas-liquid two-phase storage mentioned in the background. This system fully reuses above-ground and underground resources in abandoned mining areas, seals and seals underground spaces such as shafts and inclined tunnels with certain pressure-bearing capacity to create a large-capacity liquid storage tank for storing medium-pressure liquid carbon dioxide, and transforms underground goaf areas into distributed low-pressure carbon dioxide storage tanks using single-layer gas film materials. This device realizes the secondary development and reuse of resources in abandoned mining areas, greatly reduces the construction cost of compressed carbon dioxide systems, and avoids safety hazards caused by a large number of pressure vessels.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a compressed carbon dioxide energy storage system utilizing abandoned mine resources, comprising a compressed energy storage subsystem, wherein the compressed energy storage subsystem is connected to a heat storage and heat exchange subsystem, the heat storage and heat exchange subsystem is connected to a liquefaction and gasification subsystem, the liquefaction and gasification subsystem is connected to a medium-pressure liquid storage subsystem, the medium-pressure liquid storage subsystem is connected to an expansion and energy release subsystem, and the expansion and energy release subsystem is connected to a low-pressure gas storage subsystem.

[0006] The heat storage and heat exchange subsystem includes a cooler, a heat storage tank, a reheater, an ambient temperature pump, and a high temperature pump. The cooler is fixedly connected to one side of the compressed energy storage subsystem, the ambient temperature pump is fixedly connected to one side of the cooler, the heat storage tank is connected to one side of the ambient temperature pump, the high temperature pump is fixedly connected to one side of the heat storage tank, and the reheater is connected to one side of the high temperature pump.

[0007] Preferably, the liquefaction and vaporization subsystem includes a first condensation and liquefaction device, an evaporator device, a first control valve, and a booster pump. The first condensation and liquefaction device is fixedly connected to one side of the cooler, the evaporator device is fixedly connected to one side of the reheater, the first control valve is fixedly connected to one side of the first condensation and liquefaction device, and the booster pump is installed on one side of the evaporator device.

[0008] Preferably, the medium-pressure liquid storage subsystem includes a liquid storage unit, a pressure stabilizing device, a pressure stabilizing control valve, an inlet pipe, an outlet pipe, a pressure stabilizing and gas replenishment pipe, a pressure relief pipe and device, a sealing structure, a surrounding rock layer, surrounding rock support, concrete lining, and a sealing layer. The liquid storage unit is fixedly connected to the outlet side of the compressed energy storage subsystem. A pressure stabilizing device is installed on one side of the liquid storage unit. A pressure stabilizing control valve is fixedly connected to one side of the pressure stabilizing device. An inlet pipe is fixedly connected to one side of the liquid storage unit. One side of the liquid storage unit is fixedly connected to a liquid outlet pipe, which is connected to a booster pump. One side of the liquid storage unit is fixedly connected to a pressure stabilizing and gas replenishing pipe, and one side of the pressure stabilizing and gas replenishing pipe is fixedly connected to a pressure stabilizing device. One side of the liquid storage unit is equipped with a pressure relief pipe and device. The liquid storage unit is provided with a support and concrete lining layer in the surrounding rock layer, and a sealing layer is constructed by laying a sealing material that does not react with carbon dioxide, has good sealing performance, high strength, and good durability. The liquid storage unit is provided with sealing structures at both ends of the mine tunnel.

[0009] Preferably, depending on the project conditions and needs, waterproof membranes, drainage protection boards, geotextiles, and other components can also be installed.

[0010] Preferably, the low-pressure gas storage subsystem includes a single-membrane flexible low-pressure gas storage tank, a main gas pipeline, a second control valve, a mine shaft, a gas silo membrane, a bottom membrane, a protective pad layer, inlet and outlet gas pipelines, sealing and fixing components, a monitoring system, a ventilation and exhaust system, a drainage system, a support layer, surrounding rock of the mine shaft, and a foundation structure. The inlet side of the compressed energy storage subsystem is connected to the main gas pipeline and the second control valve. The main gas pipeline is connected to the single-membrane flexible low-pressure gas storage tank, which is located in the mine shaft.

[0011] Preferably, the mine shaft is equipped with a gas-filled membrane, which is connected to a bottom membrane and fixedly installed with a sealing and fixing component. The bottom membrane is laid on a protective pad layer, and an inlet and outlet gas pipe is installed on the bottom membrane inside the gas-filled membrane. The mine shaft is equipped with a temperature, pressure, and gas monitoring system.

[0012] Preferably, the mine is equipped with a ventilation and exhaust system, a drainage system, a support layer in the surrounding rock layer, and a foundation structure at the bottom.

[0013] Preferably, the compression energy storage subsystem is located on the ground, with its inlet end connected to the low-pressure gas storage subsystem and its exhaust end connected to the heat storage and exchange subsystem. The compression energy storage subsystem is used to pressurize the low-pressure gas carbon dioxide to achieve the system's set pressure requirements. Depending on the system design requirements, a multi-stage compression system can be adopted.

[0014] Preferably, the heat storage and heat exchange subsystem is located on the ground and mainly consists of a cooler, a heat storage tank, a reheater, a normal temperature pump, a high temperature pump, and valves and pipelines. The heat storage and heat exchange subsystem is connected to the compression energy storage subsystem, the liquefaction and gasification device, and the expansion energy release subsystem.

[0015] Preferably, the heat storage tank is used for storing the heat of compression through the circulation of hot and cold heat storage media. The heat storage media can be pressurized water, heat transfer oil, molten salt, solid heat storage bed, etc. The liquefaction and vaporization subsystem is arranged on the ground and includes a condensation and liquefaction device, an evaporator device, a booster pump and valve pipelines, etc., which are connected to the heat storage and heat exchange subsystem and the medium-pressure liquid storage tank, respectively. The inlet end of the condensation and liquefaction device is connected to the heat storage and heat exchange subsystem, and the outlet end is connected to the liquid inlet pipeline of the medium-pressure liquid storage tank. The system uses the cold energy of the cold source to realize the condensation and liquefaction of medium and high pressure gas carbon dioxide, and uses gravity to send the liquid carbon dioxide into the underground medium-pressure liquid storage tank.

[0016] Preferably, the inlet end of the booster pump is connected to the outlet of the medium-pressure storage tank, and the outlet end is connected to the evaporator device and the storage tank pressure stabilization and gas replenishment system to realize the booster delivery of liquid carbon dioxide.

[0017] Preferably, the evaporator device inlet is connected to a booster pump, utilizing heat energy from a heat source to vaporize liquid carbon dioxide, and the outlet end is connected to the inlet of a heat storage exchanger. The expansion and energy release subsystem is located on the ground, with its inlet end connected to the heat storage exchange subsystem and its exhaust end connected to the low-pressure gas storage subsystem. This expansion and energy release subsystem is used to convert potential energy into mechanical work and drive a generator to produce electricity. After energy release, the exhaust end outputs low-pressure, room-temperature carbon dioxide into the low-pressure gas storage subsystem. The expansion and energy release subsystem can employ multi-stage expansion according to system design requirements.

[0018] Preferably, the medium-pressure liquid storage subsystem is connected to the liquefaction and vaporization subsystem to realize the storage of liquid carbon dioxide.

[0019] Preferably, the liquid storage unit is formed by modifying underground shafts, inclined tunnels, and other spaces for sealing and plugging. Inclined tunnels and shafts with intact surrounding rock structures and pressure-bearing capacity that meet the storage pressure requirements of liquid carbon dioxide are selected according to the geographical depth of underground mine resources and rock strata. The loosened area of ​​the surrounding rock needs to be reinforced by high-pressure grouting.

[0020] Preferably, waterproof membranes, drainage protection boards, geotextiles, and other related measures are arranged according to project conditions and needs.

[0021] Preferably, the sealing layer material should be a sealing material that does not react with carbon dioxide, has good sealing performance, high strength, and good durability. The selection of sealing materials should also take into account the engineering site environment, cost, performance, etc., and is not limited to steel linings, high-performance composite materials, etc.

[0022] Preferably, the liquid storage unit is connected to the condensation outlet of the liquefaction and vaporization subsystem via a liquid inlet pipe, and the liquid carbon dioxide after being liquefied by the condenser under high pressure enters the storage unit cavity through the liquid inlet pipe.

[0023] Preferably, the liquid storage unit is connected to the booster pump of the liquefaction and gasification subsystem via a liquid outlet pipe, which pressurizes the liquid carbon dioxide and delivers it to the evaporator and pressure stabilizing gas supply device of the liquefaction and gasification subsystem.

[0024] Preferably, the pressure-stabilizing gas supply pipeline of the liquid storage unit is connected to the outlet of the pressure-stabilizing gas supply device. When the internal pressure of the liquid storage unit is lower than a set threshold, an appropriate amount of liquid carbon dioxide is supplied through the pressure-stabilizing gas supply device to supplement a certain amount of gaseous carbon dioxide to maintain the pressure stability of the liquid storage unit.

[0025] Preferably, the pressure relief pipeline device is connected to the low-pressure gas storage subsystem. When the internal pressure of the liquid storage unit exceeds the safe pressure value, the safety valve automatically opens to release the medium-pressure gas carbon dioxide into the low-pressure gas storage through throttling and pressure reduction.

[0026] Preferably, the low-pressure gas storage subsystem is connected to the air inlet of the compression energy storage subsystem and the exhaust of the expansion energy release subsystem.

[0027] Preferably, the low-pressure gas storage subsystem involves properly leveling a large number of underground mine shafts with limited individual capacity and scattered locations, and constructing them into distributed capsule-type single-membrane flexible low-pressure gas storage facilities using flexible sealing membrane materials. These facilities are then connected to the control valves of the compressor unit and expander unit via the main gas transmission pipeline, forming a large single-membrane flexible low-pressure gas storage facility.

[0028] Preferably, the distributed capsule-type single-membrane flexible low-pressure gas storage facility is a closed space structure made of membrane material according to the shape and size of each mine cavern space. It mainly consists of a mine cavern, gas chamber membrane, bottom membrane, protective pad layer, inlet and outlet gas pipelines, sealing and fixing components and auxiliary facilities.

[0029] Preferably, the inner wall of the mine is treated to add a support layer. Depending on the surrounding rock structure of the mine, anchor spraying support can be used. After the bottom of the mine is leveled, the foundation structure of the capsule-type flexible single membrane air chamber is constructed according to the load-bearing requirements. The foundation structure is used to support and fix the capsule-type flexible single membrane air chamber.

[0030] Preferably, the bottom membrane and the gas chamber membrane are fixed to the foundation structure ring beam by a sealing and fixing component to form a sealed gas chamber; a protective pad is laid between the bottom membrane and the bottom foundation structure to protect the bottom membrane from scratches; the inlet and outlet pipeline system is laid underground through the foundation structure ring beam to enter the sealed gas chamber, and a gas distribution network can be extended inside the gas chamber according to the size of the gas chamber and needs to more evenly inflate and deflate the gas; valve devices can be installed on the inlet and outlet pipelines, and the capsule-type flexible single membrane gas chamber is connected to the main gas pipeline along the roadway through the inlet and outlet gas pipelines; after inflation, it is supported by a gas micro-positive pressure gas storage membrane to form an arc shape. When inflation is completed, a certain space is left between the top of the capsule-type flexible single membrane gas chamber and the top of the mine to prevent the membrane material from contacting and rubbing against the inner wall; a maintenance passage of a certain width is left between the capsule-type flexible single membrane gas chamber membrane structure and the mine.

[0031] Preferably, the auxiliary system includes a monitoring system, a ventilation and exhaust system, a drainage system, etc.

[0032] Preferably, the monitoring system mainly includes a temperature, pressure, and gas sensing system and a control system, which detects the temperature, pressure, and carbon dioxide gas content inside the mine in real time, and the sensor data is transmitted to the ground monitoring room for real-time monitoring via wired or wireless means.

[0033] Preferably, the ventilation and exhaust system is used for overall ventilation and exhaust within the mine shaft. To prevent potential risks caused by the accumulation of carbon dioxide gas, a ventilation and exhaust system is installed in each mine shaft; the entire goaf area of ​​the mine can utilize the existing ventilation shafts and fan equipment in the mining area for ventilation.

[0034] Preferably, the drainage system is used to remove seepage water inside the mine, ensuring that the capsule-type flexible single-membrane air chamber does not come into direct contact with the seepage water. The drainage pipe is connected to the roadway drainage ditch, and the seepage water is discharged into the collection pool through the drainage ditch. The water is then discharged out of the cavern using pumping equipment. The drainage system can make full use of the mine's existing drainage equipment and system.

[0035] Compared with existing technologies, the beneficial effects of this utility model are as follows: This compressed carbon dioxide energy storage system utilizes abandoned mine shaft resources. In underground spaces such as vertical shafts and inclined tunnels in mining areas, it possesses a certain pressure-bearing capacity and a stable temperature environment. It can ensure that the ambient temperature of the surrounding rock and the ambient temperature of the chamber remain constant. Through sealing and plugging treatment, it can be transformed into a large-capacity liquid storage tank. Suitable temperature conditions can be constructed based on the pressure-temperature relationship of carbon dioxide to store medium-pressure liquid carbon dioxide. Compared with the traditional method of storing liquid carbon dioxide using pressure vessels, this greatly reduces the investment cost and land requirements of the compressed carbon dioxide system, avoids the safety hazards associated with operating medium- and high-pressure pressure vessels, and significantly reduces the complexity of system engineering, design, and operation control. The distributed capsule-type flexible single-membrane gas chamber construction method fully utilizes the original structure of the mine shaft. Based on the characteristics and conditions, simple leveling of mine shafts can effectively utilize existing underground mine space resources, greatly reducing the land occupation requirements of traditional large-scale gas storage systems, saving land and costs. At the same time, the natural shielding effect of underground space against ultraviolet rays, wind, rain, snow and other climatic factors can be utilized for the effective development and utilization of mine resources. The capsule-type flexible single-membrane gas chamber structure eliminates the need for an outer membrane, steel cable net and make-up air system, which can effectively reduce the construction cost and cycle of the system. This device is designed for widely distributed abandoned mine resources. According to the geological conditions of different areas inside the mine, it takes advantage of the mine's certain pressure bearing capacity, shielding effect and stable temperature environment, and other favorable factors, and effectively combines them with the application of compressed carbon dioxide energy storage system. This not only realizes the secondary development and utilization of abandoned mine resources, but also promotes the development of compressed carbon dioxide energy storage technology. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the overall appearance and structure of the present utility model;

[0037] Figure 2 This is a schematic diagram of the structure of the liquid outlet pipe and the pressure stabilizing gas supply pipe of this utility model.

[0038] Figure 3 This is a schematic diagram of the structure in which the surrounding rock layer and the waterproof membrane cooperate.

[0039] Figure 4 This is a schematic diagram of the interaction between the surrounding rock and the foundation structure of the mine in this utility model;

[0040] Figure 5 This is a schematic diagram of the structure of the single-membrane flexible low-pressure gas storage tank and the gas transmission pipeline of this utility model.

[0041] In the diagram: 1. Compression energy storage subsystem; 2. Thermal storage and heat exchange subsystem; 201. Cooler; 202. Thermal storage tank; 203. Reheater; 204. Ambient temperature pump; 205. High temperature pump; 3. Liquefaction and vaporization subsystem; 301. First condensation and liquefaction unit; 302. Evaporator unit; 303. First control valve; 304. Booster pump; 4. Medium-pressure liquid storage tank subsystem; 401. Liquid storage unit; 402. Pressure stabilizing device; 403. Pressure stabilizing control valve; 4011. Inlet pipe; 4012. Outlet pipe; 4013. Pressure stabilizing and gas replenishment pipe; 4014. Pressure relief pipe and device; 4015. Sealing structure; 40 16. Surrounding rock layer; 4017. Surrounding rock support; 4018. Concrete lining; 4019. Sealing layer; 5. Expansion energy release subsystem; 6. Low-pressure gas storage subsystem; 601. Single-membrane flexible low-pressure gas storage tank; 602. Main gas transmission line; 603. Second control valve; 6011. Mine tunnel; 6012. Gas chamber membrane; 6013. Bottom membrane; 6014. Protective cushion layer; 6015. Inlet and outlet gas pipelines; 6016. Sealing and fixing components; 6017. Monitoring system; 6018. Ventilation and exhaust system; 6019. Drainage system; 60100. Support layer; 60101. Mine surrounding rock; 60102. Foundation structure. Detailed Implementation

[0042] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0043] Please see Figure 1-5This utility model provides a technical solution: a compressed carbon dioxide energy storage system utilizing abandoned mine resources, comprising a compressed energy storage subsystem 1, a heat storage and heat exchange subsystem 2 connected to one side of the compressed energy storage subsystem 1, a liquefaction and gasification subsystem 3 connected to one side of the heat storage and heat exchange subsystem 2, a medium-pressure liquid storage subsystem 4 connected to one side of the liquefaction and gasification subsystem 3, an expansion and energy release subsystem 5 connected to one side of the medium-pressure liquid storage subsystem 4, and a low-pressure gas storage subsystem 6 connected to one side of the expansion and energy release subsystem 5. The heat storage and heat exchange subsystem 2 includes a cooler 201, a heat storage tank 202, a reheater 203, a normal temperature pump 204, and a high temperature pump 205. The cooler 201 is fixedly connected to one side of the compressed energy storage subsystem 1, the normal temperature pump 204 is fixedly connected to one side of the cooler 201, the heat storage tank 202 is connected to one side of the normal temperature pump 204, the high temperature pump 205 is fixedly connected to one side of the heat storage tank 202, and the reheater 203 is connected to one side of the high temperature pump 205.

[0044] Furthermore, the liquefaction and vaporization subsystem 3 includes a first condensation and liquefaction device 301, an evaporator device 302, a first control valve 303, and a booster pump 304. The first condensation and liquefaction device 301 is fixedly connected to one side of the cooler 201, the evaporator device 302 is fixedly connected to one side of the reheater 203, the first control valve 303 is fixedly connected to one side of the first condensation and liquefaction device 301, and the booster pump 304 is installed on one side of the evaporator device 302.

[0045] Furthermore, the medium-pressure liquid storage subsystem 4 includes a liquid storage unit 401, a pressure stabilizing device 402, a pressure stabilizing control valve 403, an inlet pipe 4011, an outlet pipe 4012, a pressure stabilizing and gas replenishment pipe 4013, a pressure relief pipe and device 4014, a sealing structure 4015, a surrounding rock layer 4016, a surrounding rock support 4017, a concrete lining 4018, and a sealing layer 4019. The liquid storage unit 401 is fixedly connected to the outlet side of the compressed energy storage subsystem 1. A pressure stabilizing device 402 is installed on one side of the liquid storage unit 401, and a pressure stabilizing control valve 403 is fixedly connected to one side of the pressure stabilizing device 402. One side of the liquid storage unit 401... A liquid inlet pipe 4011 is fixedly connected to one side of the liquid storage unit 401. A liquid outlet pipe 4012 is fixedly connected to one side of the liquid storage unit 401. The liquid outlet pipe is connected to a booster pump 304. A pressure stabilizing and gas replenishing pipe 4013 is fixedly connected to one side of the liquid storage unit 401. A pressure stabilizing device 402 is fixedly connected to one side of the pressure stabilizing and gas replenishing pipe 4013. A pressure relief pipe and device 4014 is installed on one side of the liquid storage unit 401. The liquid storage unit 401 is supported by a support layer 4017 and a concrete lining layer 4018 based on the surrounding rock layer 4016 of the mine shaft. A sealing layer 4019 is constructed by laying sealing material. A sealing structure 4015 is set at both ends of the mine shaft for the liquid storage unit.

[0046] Furthermore, depending on the project conditions and needs, measures such as waterproof membranes, drainage protection boards, and geotextiles can also be adopted.

[0047] Furthermore, the low-pressure gas storage subsystem 6 includes a single-membrane flexible low-pressure gas storage 601, a main gas transmission line 602, a second control valve 603, a mine shaft 6011, a gas chamber membrane 6012, a bottom membrane 6013, a protective pad layer 6014, inlet and outlet gas pipes 6015, a sealing and fixing assembly 6016, a monitoring system 6017, a ventilation and exhaust system 6018, a drainage system 6019, a support layer 60100, surrounding rock of the mine shaft 60101, and a foundation structure 60102. The inlet side of the compressed energy storage subsystem 1 is connected to the main gas transmission line 602 and the second control valve 603. The main gas transmission line 602 is connected to the single-membrane flexible low-pressure gas storage 601, which is located in the mine shaft 6011.

[0048] Furthermore, a gas chamber membrane 6012 is fixedly connected to one side of the mine shaft 6011. The gas chamber membrane 6012 is connected to the bottom membrane 6013 and fixedly connected to the sealing and fixing component 6016. The bottom membrane 6013 is laid on the protective pad layer 6014. An inlet and outlet air pipe 6015 is installed on the bottom membrane 6013 inside the gas chamber. A monitoring system 6017 is installed inside the mine shaft 6011.

[0049] Furthermore, a ventilation and exhaust system 6018 is installed inside the mine shaft 6011, a drainage system 6019 is installed inside the mine shaft 6011, a support layer 60100 is implemented inside the surrounding rock layer 60101 of the mine shaft 6011, and a foundation structure 60102 is implemented at the bottom of the mine shaft 6011.

[0050] Furthermore, on the compression side, the inlet end of the cooler 201 is connected to the exhaust ends of each section of the compression subsystem, and the heat energy of compression is recovered and stored through the heat exchanger; the outlet end is connected to the liquefaction and gasification device, and room temperature high pressure carbon dioxide is sent into the liquefaction and gasification device to achieve liquefaction.

[0051] Furthermore, on the expansion side, the inlet end of the reheater 203 is connected to the liquefaction and gasification device, and the high-pressure carbon dioxide gas is reheated by the recovered compressed heat through the reheater 203; the outlet end is connected to the expansion energy release subsystem 5, and the high-pressure high-temperature carbon dioxide is sent into the expansion energy release subsystem 5.

[0052] Furthermore, the surrounding rock layer 4016 is supported by shotcrete and anchor support 4017, and then a full-section reinforced concrete lining 4018 is constructed. Waterproof membrane, drainage protection board, and geotextile components are arranged according to the project conditions and needs.

[0053] Furthermore, after smoothing the inside of the reinforced concrete lining, a sealing layer 4019 is constructed using a sealing material that does not react with carbon dioxide, has good sealing performance, high strength, and good durability. The selection of sealing materials also needs to consider engineering geological environment, cost, performance, etc., and is not limited to steel lining, high-performance composite materials, etc.

[0054] Furthermore, the sealing structure 4015 includes a specially made sealing material inside the cavity and a concrete barrier on the outer layer; and an inlet pipe 4011, an outlet pipe 4012, a pressure stabilizing and gas replenishing pipe 4013, and a pressure relief pipe and device 4014 are provided at the near-ground end of the sealing structure 4015.

[0055] Furthermore, for the sake of safe production, auxiliary systems may also include security systems, power distribution systems such as lighting, and fire protection systems.

[0056] Furthermore, the distributed membrane flexible gas storage facility is connected to the compressor unit subsystem and expander unit system of the compressed carbon dioxide energy storage system via a main gas pipeline leading to the outside of the mine. During the energy storage phase, the main gas pipeline is connected to the compressor system inlet, delivering gaseous carbon dioxide to the compressor inlet; during the energy release phase, the main gas pipeline is connected to the expander unit outlet, storing gaseous carbon dioxide in the distributed membrane flexible gas storage facility.

[0057] Working principle: First, the intake end of the compression energy storage subsystem 1 is connected to the low-pressure gas storage subsystem 6, and the exhaust end is connected to the heat storage and heat exchange subsystem 2. This allows the compression energy storage subsystem 1 to connect to the low-pressure gas storage subsystem 6 via the intake end. Then, the compression energy storage subsystem 1 is used to pressurize the low-pressure gas carbon dioxide to reach the system's set pressure requirements. Depending on the system design requirements, a multi-stage compression can be adopted. The heat storage and heat exchange subsystem 2 is located on the ground, and then it is connected to the compression energy storage subsystem 6 via the heat storage subsystem 6. Subsystem 1, liquefaction and gasification device 3, and expansion and energy release subsystem 5 are connected. On the compression side, the inlet end of cooler 201 is connected to the exhaust end of each section of the compression subsystem. The heat energy of compression is recovered and stored through the heat exchanger. Then, the outlet end is connected to the liquefaction and gasification device to send room temperature high-pressure carbon dioxide into the liquefaction and gasification device for liquefaction. On the expansion side, the inlet end of reheater 203 is connected to the liquefaction and gasification device to reheat the gas high-pressure carbon dioxide through reheater 203 using the recovered compression heat.The outlet end is connected to the expansion and energy release subsystem 5. High-pressure, high-temperature carbon dioxide is sent into the expansion and energy release subsystem 5, and then the heat storage tank 202 stores the heat of compression through the circulation of hot and cold heat storage media. The heat storage media can be pressurized water, heat transfer oil, molten salt, solid heat storage bed, etc. The inlet end of the condensation and liquefaction device is connected to the heat storage and heat exchange subsystem 2, and the outlet end is connected to the liquid inlet pipe 4011 of the medium-pressure liquid storage tank. The system uses the cold energy of the cold source to realize the condensation and liquefaction of medium-pressure gaseous carbon dioxide, and uses gravity to send the liquid carbon dioxide into the underground medium-pressure liquid storage tank. Then the expansion and energy release subsystem 5 is arranged on the ground, and the gas inlet end is connected to the heat storage and heat exchange subsystem 202. The thermal subsystem 2 is connected, and the exhaust end is connected to the low-pressure gas storage subsystem 6. Then, the expansion and energy release subsystem 5 is used to convert potential energy into mechanical work and drive the generator to generate electricity. After energy release, the exhaust end outputs low-pressure room-temperature carbon dioxide into the low-pressure gas storage. The expansion and energy release subsystem 5 can adopt multi-stage expansion according to the system design requirements. Then, the liquid storage unit 401 is formed by sealing and plugging underground shafts, inclined tunnels, and other spaces. According to the burial depth and rock strata, inclined tunnels and shaft spaces with intact surrounding rock structures and pressure bearing capacity that meet the storage pressure requirements of liquid carbon dioxide are selected. The loosened zone of the surrounding rock needs to be filled by high-pressure injection. The slurry is reinforced. The liquid storage unit 401 is connected to the condenser outlet of the liquefaction and vaporization subsystem 3 via the liquid inlet pipe 4011. Liquid carbon dioxide, liquefied from high-pressure carbon dioxide in the condenser, enters the storage unit cavity through the liquid inlet pipe 4011. The liquid storage unit 401 is connected to the booster pump 304 of the liquefaction and vaporization subsystem 3 via the liquid outlet pipe 4012, which pressurizes the liquid carbon dioxide and delivers it to the evaporator and pressure stabilizing gas supply device of the liquefaction and vaporization subsystem 3. The pressure stabilizing gas supply pipe 4013 of the liquid storage unit 401 is connected to the outlet of the pressure stabilizing gas supply device. When the internal pressure of the liquid storage unit 401 is lower than a set threshold, it will... An appropriate amount of liquid carbon dioxide is supplemented with a certain amount of gaseous carbon dioxide through a pressure stabilizing and gas replenishment device to maintain the pressure stability of the liquid storage unit 401. Then, the bottom membrane 6013 and the gas chamber membrane 6012 are fixed to the ring beam of the foundation structure 60102 through the sealing and fixing component 6016 to form a sealed gas chamber. A protective pad 6014 is laid between the bottom membrane 6013 and the bottom foundation structure 60102 to protect the bottom membrane 6013 from scratches. The inlet and outlet pipeline system is laid underground through the ring beam of the foundation structure 60102 to enter the sealed gas chamber. Depending on the size of the gas chamber and the needs, a gas distribution network can be extended inside the gas chamber to more evenly fill and release gas.Valves can be installed on the inlet and outlet pipes. The capsule-type flexible single-membrane gas chamber is connected to the main gas pipeline along the roadway via inlet and outlet gas pipes 6015. After inflation, it is supported by a slightly positive pressure gas storage membrane in an arc shape. When inflation is complete, a certain space is left between the top of the capsule-type flexible single-membrane gas chamber and the top of the mine shaft 6011 to prevent contact friction between the membrane material and the inner wall. A certain width of maintenance passage is left between the capsule-type flexible single-membrane gas chamber membrane 6012 structure and the mine shaft 6011. Then, the ventilation and exhaust system is used for overall ventilation and exhaust inside the mine shaft 6011 to prevent secondary... To mitigate the potential risks posed by the accumulation of carbon dioxide gas, a ventilation and exhaust system is installed in each mine shaft 6011. The entire goaf area of ​​mine shaft 6011 can utilize existing ventilation shafts and fan equipment for ventilation. Finally, drainage system 6019 is used to remove seepage water from inside mine shaft 6011, ensuring that the capsule-type flexible single-membrane air chamber does not directly contact the seepage water. The drainage pipeline is connected to the roadway drainage ditch, through which seepage water is discharged into a collection pool. Pumping equipment is then used to remove the water from the cavern. Drainage system 6019 utilizes the existing drainage equipment and system of mine shaft 6011 as much as possible.

[0058] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A compressed carbon dioxide energy storage system utilizing abandoned mine shaft resources, characterized in that, This system comprises a compression energy storage subsystem (1), a heat storage and heat exchange subsystem (2), a liquefaction and vaporization subsystem (3), a medium-pressure liquid storage subsystem (4), an expansion and energy release subsystem (5), a low-pressure gas storage subsystem (6), and related auxiliary facilities. The compression energy storage subsystem (1) is connected to a heat storage and heat exchange subsystem (2) on one side. The heat storage and heat exchange subsystem (2) is connected to a liquefaction and vaporization subsystem (3) on one side. The liquefaction and vaporization subsystem (3) is connected to a medium-pressure liquid storage subsystem (4) on one side. The expansion and energy release subsystem (5) is fixedly connected to a side of the medium-pressure liquid storage subsystem (4). The expansion and energy release subsystem (5) is connected to a low-pressure gas storage subsystem (6) on one side. The heat storage and heat exchange subsystem (2) includes a cooler (201), a heat storage tank (202), a reheater (203), a normal temperature pump (204), and a high temperature pump (205). The cooler (201) is fixedly connected to one side of the compression energy storage subsystem (1). The normal temperature pump (204) is fixedly connected to one side of the cooler (201). The heat storage tank (202) is fixedly connected to one side of the normal temperature pump (204). The high temperature pump (205) is fixedly connected to one side of the heat storage tank (202). The reheater (203) is fixedly connected to one side of the high temperature pump (205).

2. The compressed carbon dioxide energy storage system utilizing abandoned mine resources according to claim 1, characterized in that: The liquefaction and vaporization subsystem (3) includes a first condensation and liquefaction device (301), an evaporator device (302), a first control valve (303), and a booster pump (304). The first condensation and liquefaction device (301) is fixedly connected to one side of the cooler (201), the evaporator device (302) is fixedly connected to one side of the reheater (203), the first control valve (303) is fixedly connected to one side of the first condensation and liquefaction device (301), and the booster pump (304) is installed on one side of the evaporator device (302).

3. A compressed carbon dioxide energy storage system utilizing abandoned mine resources according to claim 1, characterized in that: The medium-pressure liquid storage subsystem (4) includes a liquid storage unit (401), a pressure stabilizing device (402), a pressure stabilizing control valve (403), an inlet pipe (4011), an outlet pipe (4012), a pressure stabilizing gas supply pipe (4013), a pressure relief pipe and device (4014), a sealing structure (4015), a surrounding rock layer (4016), surrounding rock support (4017), a concrete lining (4018), and a sealing layer (4019). The liquid storage unit (401) is fixedly connected to one side of the compressed energy storage subsystem (1), and a pressure stabilizing device is installed on one side of the liquid storage unit (401). The pressure stabilizing device (402) is fixedly connected to a pressure stabilizing control valve (403) on one side, and a liquid inlet pipe (4011) is fixedly connected to one side of the liquid storage unit (401). A liquid outlet pipe (4012) is fixedly connected to one side of the liquid storage unit (401), and a pressure stabilizing gas supply pipe (4013) is fixedly connected to one side of the pressure stabilizing control valve (403). A pressure relief pipe and device (4014) is installed on one side of the liquid storage unit (401), and a sealing structure (4015) is fixedly connected to one side of the pressure relief pipe and device (4014).

4. A compressed carbon dioxide energy storage system utilizing abandoned mine resources according to claim 1, characterized in that: The low-pressure gas storage subsystem (6) includes a single-membrane flexible low-pressure gas storage tank (601), a main gas transmission pipeline (602), a second control valve (603), a mine shaft (6011), a gas storage membrane (6012), a bottom membrane (6013), a protective cushion layer (6014), inlet and outlet gas pipelines (6015), a sealing and fixing assembly (6016), a monitoring system (6017), a ventilation and exhaust system (6018), a drainage system (6019), a support layer (60100), and surrounding rock of the mine shaft (6010). The compressed energy storage subsystem (1) is connected to a single-membrane flexible low-pressure gas storage tank (601) via a gas transmission main line (602) and a second control valve (603) on one side. A gas transmission main line (602) is fixedly connected to one side of the single-membrane flexible low-pressure gas storage tank (601), and a second control valve (603) is fixedly connected to one side of the gas transmission main line (602). The single-membrane flexible low-pressure gas storage tank (601) is arranged in the mine tunnel (6011).

5. A compressed carbon dioxide energy storage system utilizing abandoned mine shaft resources according to claim 4, characterized in that: The air chamber membrane (6012) is connected to the bottom membrane (6013), the bottom membrane (6013) is arranged on the protective pad layer (6014), the air inlet and outlet pipes (6015) are evenly arranged on the bottom membrane (6013), and a sealing and fixing component (6016) is installed. The mine tunnel (6011) is equipped with a monitoring system (6017), a ventilation and exhaust system (6018), and a drainage system (6019).

6. A compressed carbon dioxide energy storage system utilizing abandoned mine resources according to claim 4, characterized in that: The mine shaft (6011) is equipped with a monitoring system (6017), a ventilation and exhaust system (6018), a drainage system (6019), a support layer (60100) on the inner surface of the surrounding rock (60101) of the mine shaft (6011), and a foundation structure (60102) at the bottom of the mine shaft (6011).

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