Compressed air energy storage power station

Abstract

The invention provides a compressed air energy storage power station which comprises a compression energy storage system, a heat storage and exchange system, an air storage system, an expansion energy release system, a water supply system, a cooling facility and other auxiliary systems. The compressed air energy storage power station is built by utilizing temporary buildings, construction factory facilities, power transmission equipment facilities and roads inside and outside the field of the hydropower engineering, the installed capacity is comprehensively determined according to the total available conditions of the hydropower engineering and the power grid requirements, and the compressed air energy storage power station and the hydropower engineering are jointly operated. According to the invention, watercourse tail water of hydropower engineering and abandoned temporary buildings and construction factory facilities are fully utilized, power transmission equipment facilities and roads inside and outside the field are shared, the problems of land acquisition, immigrant settlement and water sources are solved, and the construction and production management costs of engineering civil engineering, equipment facilities and the like are reduced. Meanwhile, through combined operation with hydropower engineering, electric energy is bundled and sent out, power generation benefits are increased, the utilization rate of a sending-out system is improved, and standby of a power system is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of hydropower and compressed air energy storage, and in particular relates to a compressed air energy storage power station. Background Art

[0002] At present, there are tens of thousands of hydropower projects, and their temporary buildings and construction plant facilities will be completely abandoned after use. Corresponding measures such as sealing, demolition, and ecological restoration will be taken, and the construction and treatment costs are relatively high. In particular, diversion tunnels need to meet the flood discharge requirements of the reservoir, and the requirements for tunnel exploration, surrounding rock geological conditions, lining types and sealing are more stringent, and the construction and treatment costs are even higher. At the same time, hydropower stations also have the problem of shutdown caused by the inability to access the grid during the low load period of the power grid. Compressed air energy storage power stations have a long energy storage cycle and can use low-peak, abandoned hydropower, wind and solar power to store energy, generate electricity during peak grid load periods, have strong peak-shaving and frequency regulation capabilities, and respond quickly. They play an important role in ensuring the safe, stable and economical operation of the power system. However, compressed air energy storage power stations are currently independently constructed and managed, requiring separate engineering planning, survey and design, land acquisition and resettlement, construction, operation and maintenance, and construction of dedicated buildings, on-site roads, and delivery systems. It is difficult to find natural caves that are large in size, airtight, and stable, and the gas storage facilities of compressed air energy storage power stations are mostly ground gas tanks or artificially built caverns. The exploration workload is large and time-consuming, and the cooling system of the compressed air energy storage power station requires a large amount of water, resulting in high project investment.

[0003] Therefore, in the prior art, there are many problems such as high construction and treatment costs for temporary buildings and construction plant facilities of hydropower projects, large investment in compressed air energy storage power station projects, and shutdown of hydropower stations due to the inability to generate electricity and access the grid during the low-load period of the power grid. Summary of the invention

[0004] In view of the defects of the prior art, the present invention provides a compressed air energy storage power station, which can effectively solve the above problems.

[0005] The technical solution adopted by the present invention is as follows:

[0006] The present invention provides a compressed air energy storage power station, comprising a compressed energy storage system (1), a heat storage and exchange system (2), a gas storage system (3), an expansion energy release system (4), a water supply system and cooling facilities (5) and other auxiliary systems (6); the compressed air energy storage power station is constructed using temporary buildings (8), construction plant facilities (9), power transmission equipment facilities (10) and on-site roads (11) of a hydropower project (7); the installed capacity is comprehensively determined based on the overall available conditions of the hydropower project (7) and the demand of the power grid, and is operated in conjunction with the hydropower project (7).

[0007] Preferably, the heat storage and exchange system (2) comprises a heat exchanger (2.1), a normal temperature heat storage tank (2.2) and a high temperature heat storage tank (2.3);

[0008] The gas charging and discharging ends of the gas storage system (3) are respectively connected to one end of the normal temperature heat storage tank (2.2) and one end of the high temperature heat storage tank (2.3) through the heat exchanger (2.1); the other end of the normal temperature heat storage tank (2.2) is connected to the compression energy storage system (1); and the other end of the high temperature heat storage tank (2.3) is connected to the expansion energy release system (4).

[0009] Preferably, the hydropower project (7) includes a conventional hydropower station and a pumped storage power station;

[0010] The temporary buildings (8) include diversion tunnels, construction branch tunnels and exploration tunnels of the hydropower project (7);

[0011] The construction plant facilities (9) include the sand and gravel processing system, concrete production system, concrete preheating and preheating system, compressed air system, water supply, power supply and communication system, and comprehensive processing and machinery repair plant of the hydropower project (7);

[0012] The power transmission equipment and facilities (10) include a substation or a switch station and a transmission line of the hydropower project (7).

[0013] Preferably, the gas storage system (3) adopts an underground gas storage reservoir, a ground gas storage tank, or a combination of an underground gas storage reservoir and a ground gas storage tank.

[0014] Preferably, when the underground gas storage utilizes the diversion tunnel, the construction branch tunnel or the exploration tunnel, after the cavern completes the corresponding use function in the hydropower project (7), the two ends of the cavern are sealed and rebuilt or expanded;

[0015] The underground gas storage comprises a plug (3.1) at one end of the tunnel, a plug (3.2) at the other end of the tunnel and a middle section (3.3) of the tunnel, and is a high-pressure resistant concrete structure, a reinforced concrete structure or a steel-lined concrete structure; a charging and discharging pipe (3.4) and a maintenance passage (3.5) are buried in the plug (3.1) at one end of the tunnel or the plug (3.2) at the other end of the tunnel; the head and tail of the charging and discharging pipe (3.4) are respectively connected to the underground gas storage and the heat exchanger (2.1); the maintenance passage (3.5) is provided with a sealed door, the cross-sectional dimensions of which meet the requirements for the entry and exit of personnel, machinery and materials during maintenance, and is only opened when the underground gas storage needs to be inspected or repaired;

[0016] The gas storage pressure range of the underground gas storage is 5MPa to 20MPa, and the design pressure is determined according to the lining structure type and the overall conditions of the rock (12) surrounding the cave, and should also meet the safety and stability requirements of the lining structure and the rock (12) surrounding the cave.

[0017] Preferably, the compressed air energy storage power station constructed on the ground using the temporary buildings (8) and the construction plant facilities (9) should be rebuilt after the corresponding functions in the hydropower project (7) are completed. The ground elevation should be higher than the highest flood level at the corresponding location of the hydropower project (7), and a safety overheight of not less than 1m should be reserved. When built on a soft foundation, sufficient settlement overheight should also be reserved according to the soft foundation properties and stress conditions.

[0018] Preferably, the water source of the water supply system and cooling facilities (5) is taken from the downstream river (13) of the hydropower project (7).

[0019] Preferably, the compressed air energy storage power station operates in conjunction with the hydropower project (7) to bundle and input or output electrical energy.

[0020] Preferably, the compressed air energy storage power station and the hydropower project (7) are jointly operated in the following manner:

[0021] When the hydropower project (7) is a conventional hydropower station, the compressed air energy storage power station and the conventional hydropower station are operated in a joint manner as follows: when the power grid has surplus electricity, the compressed energy storage system (1) first consumes the power generated by the conventional hydropower station (7.2), and the remaining surplus electricity of the power grid is used for the remaining surplus electricity; when the power grid is insufficient, the conventional hydropower station (7.2) generates electricity first and then transmits it, and the remaining insufficient electricity is transmitted by the expansion energy release system (4);

[0022] When the hydropower project (7) is a pumped-storage power station, the compressed air energy storage power station and the pumped-storage power station are jointly operated in the following manner: the design efficiency and grid-connected electricity price of the compressed air energy storage power station and the pumped-storage power station are comprehensively analyzed, and the power station with better economic indicators is given priority in energy storage and power generation operation.

[0023] The compressed air energy storage power station provided by the present invention has the following advantages:

[0024] The compressed air energy storage power station makes full use of the tailwater of the river channel of the hydropower project and the abandoned temporary buildings and construction plant facilities for layout, and shares its power transmission equipment and facilities and roads inside and outside the site. There is no need to separately expropriate land and resettle people and find other water sources, which can reduce the difficulty of construction, speed up project approval and construction progress, and save the construction and production management costs of exploration, civil engineering, equipment and facilities shared with the hydropower project; at the same time, the abandoned temporary buildings and construction plant facilities of the hydropower project are directly used as the gas storage and construction facilities of the compressed air energy storage power station, realizing the effective reuse of the abandoned temporary buildings and construction plant facilities, with a simple utilization method and low utilization cost, solving the problem of high construction and treatment costs; at the same time, through the joint operation of the compressed air energy storage power station and the hydropower project, the bundled delivery can greatly increase the power generation efficiency, improve the utilization rate of the delivery system, reduce the standby of the power system, and solve the shutdown problem caused by the inability of the hydropower station to generate electricity and access the Internet during the low load period of the power grid. The present invention effectively guarantees the safe, stable and economical operation of the power system, and has broad guiding and popularization significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic plan view of a compressed air energy storage power station of the present invention;

[0026] Figure 2 It is the A-A section of the plan schematic diagram of a compressed air energy storage power station of the present invention;

[0027] Figure 3 It is a B-B section of a plan view of a compressed air energy storage power station of the present invention;

[0028] in:

[0029] 1-Compression energy storage system; 2-heat storage and exchange system; 3-gas storage system; 4-expansion energy release system; 5-water supply system and cooling facilities; 6-other auxiliary systems; 7-hydropower engineering; 8-temporary buildings; 9-construction factory facilities; 10-power transmission equipment and facilities; 11-roads inside and outside the site; 12-rocks around the cave; 13-downstream river;

[0030] 2.1-heat exchanger; 2.2-normal temperature heat storage tank; 2.3-high temperature heat storage tank; 3.1-plug at one end of the tunnel; 3.2-plug at the other end of the tunnel; 3.3-middle section of the tunnel; 3.4-charging and discharging pipes; 3.5-inspection passage;

[0031] The direction indicated by the arrow is the direction of water flow. DETAILED DESCRIPTION

[0032] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0033] The purpose of the present invention is to provide a compressed air energy storage power station, which makes full use of the tailwater of the hydropower project river channel and abandoned temporary buildings and construction plant facilities, and shares its power transmission equipment and facilities and roads inside and outside the site, solving the problems of land acquisition, resettlement of immigrants, and water sources, as well as reducing the construction and production management costs of engineering civil engineering, equipment and facilities. At the same time, by operating in conjunction with the hydropower project, the power is bundled and sent out, the power generation efficiency is increased, the utilization rate of the transmission system is improved, and the backup of the power system is reduced.

[0034] refer to Figure 1 to Figure 3 The present invention provides a compressed air energy storage power station, which includes a compressed energy storage system 1, a heat storage and exchange system 2, a gas storage system 3, an expansion energy release system 4, a water supply system and cooling facilities 5 and other auxiliary systems 6; the compressed air energy storage power station is built using temporary buildings 8, construction plant facilities 9, power transmission equipment facilities 10 and on-site roads 11 of a hydropower project 7, and the installed capacity is comprehensively determined based on the overall available conditions of the hydropower project 7 and the needs of the power grid, and is operated in conjunction with the hydropower project 7.

[0035] The heat storage and exchange system 2 mainly includes a heat exchanger 2.1, a normal temperature heat storage tank 2.2 and a high temperature heat storage tank 2.3; the charging and discharging ends of the gas storage system 3 are respectively connected with one end of the normal temperature heat storage tank 2.2 and one end of the high temperature heat storage tank 2.3 through the heat exchanger 2.1; the other end of the normal temperature heat storage tank 2.2 is connected with the compression energy storage system 1; the other end of the high temperature heat storage tank 2.3 is connected with the expansion energy release system 4.

[0036] In the present invention, the hydropower project 7 includes conventional hydropower stations and pumped-storage power stations; the temporary buildings 8 mainly include diversion tunnels, construction branch tunnels and exploration tunnels of the hydropower project 7; the construction plant facilities 9 mainly include the sand and gravel processing system, concrete production system, concrete preheating and preheating system, compressed air system, water supply and power supply and communication system, comprehensive processing and machinery repair plant of the hydropower project 7; the power transmission equipment facilities 10 mainly include the substation or switch station and transmission lines of the hydropower project 7.

[0037] In the present invention, the gas storage system 3 may be an underground gas storage reservoir, a ground gas storage tank, or a combination of an underground gas storage reservoir and a ground gas storage tank.

[0038] As a preferred mode, when an underground gas storage is used, or a combination of an underground gas storage and a ground gas storage tank, when the underground gas storage utilizes the diversion tunnel, the construction branch tunnel or the exploration tunnel, the two ends of the tunnel body should be sealed and rebuilt or expanded after the cavern completes the corresponding use function in the hydropower project 7;

[0039] Combination Figure 2 and Figure 3 The underground gas storage includes a plug 3.1 at one end of the tunnel, a plug 3.2 at the other end of the tunnel and a middle section 3.3 of the tunnel, which are high-pressure resistant concrete structures, reinforced concrete structures or steel-lined concrete structures; a charging and discharging pipe 3.4 and an inspection channel 3.5 are buried in the plug 3.1 at one end of the tunnel or the plug 3.2 at the other end of the tunnel; the head and tail of the charging and discharging pipe 3.4 are respectively connected to the underground gas storage and the heat exchanger 2.1; the inspection channel 3.5 is provided with a sealed door, the cross-sectional size of which meets the requirements for the entry and exit of personnel, machinery and materials during maintenance, and is only opened when the underground gas storage needs to be inspected or repaired;

[0040] The gas storage pressure range of the underground gas storage is 5MPa to 20MPa, and the design pressure is determined according to the lining structure type and the overall conditions of the rock 12 surrounding the cave, and should also meet the safety and stability requirements of the lining structure and the rock 12 surrounding the cave.

[0041] The part of the compressed air energy storage power station built on the ground using the temporary buildings 8 and the construction plant facilities 9 should be rebuilt after it completes the corresponding use functions in the hydropower project 7. The ground elevation should be higher than the highest flood level at the corresponding position of the hydropower project 7, and a safety overheight of not less than 1m should be reserved; when built on a soft foundation, sufficient settlement overheight should also be reserved according to the soft foundation properties and stress conditions.

[0042] The water source of the water supply system and cooling facilities 5 is taken from the downstream river 13 of the hydropower project 7.

[0043] The compressed air energy storage power station operates in conjunction with the hydropower project 7 to bundle and input or output electrical energy.

[0044] The combined operation mode of the compressed air energy storage power station and the hydropower project 7 is:

[0045] When the hydropower project 7 is a conventional hydropower station, the compressed air energy storage power station and the conventional hydropower station are jointly operated in the following manner: when the power grid has surplus electricity, the compressed energy storage system 1 first consumes the power generated by the conventional hydropower station 7.2, and the remaining surplus electricity of the power grid is used for the insufficient part; when the power grid is insufficient, the conventional hydropower station 7.2 generates electricity first and sends it out, and the remaining insufficient part is sent out by the expansion energy release system 4;

[0046] When the hydropower project 7 is a pumped-storage power station, the joint operation mode of the compressed air energy storage power station and the pumped-storage power station is: comprehensively analyze the design efficiency and grid-connected electricity price of the compressed air energy storage power station and the pumped-storage power station, and the power station with better economic indicators gives priority to energy storage and power generation operations.

[0047] The compressed air energy storage power station provided by the present invention has the following characteristics:

[0048] (1) Compressed air energy storage power stations are built directly using temporary buildings, construction plant facilities, power transmission equipment and facilities, and on-site roads of hydropower projects. Since they share power transmission equipment and facilities and on-site roads with hydropower projects, the construction difficulty can be reduced, saving the exploration, civil engineering, equipment and facilities construction and production management costs of the parts shared with hydropower projects;

[0049] (2) Only a small amount of modification is required to temporary buildings such as diversion tunnels, construction branch tunnels and exploration tunnels of the hydropower project to transform them into underground gas storage reservoirs of compressed air energy storage power stations, meeting the gas storage pressure and safety and stability requirements of underground gas storage reservoirs of compressed air energy storage power stations;

[0050] Therefore, on the one hand, the abandoned temporary buildings of the hydropower project are effectively reused, the utilization method is simple, the utilization cost is low, and the problem of high construction and disposal costs is solved; on the other hand, the construction cost of the underground gas storage of the compressed air energy storage power station is reduced;

[0051] (3) When the compressed air energy storage power station is arranged in combination with the hydropower project, the water source of the hydropower project, such as the water source of the downstream river, is directly used as the water supply system and cooling facilities of the compressed air energy storage power station to ensure the efficient operation of the compressed air energy storage power station. Therefore, the construction cost of the water supply system and cooling facilities of the compressed air energy storage power station can be reduced;

[0052] (4) The joint operation of compressed air energy storage power stations and hydropower projects can increase power generation efficiency, improve the utilization rate of the transmission system, and reduce the backup of the power system. In addition, during the low load period of the power grid, the hydropower station can continue to generate electricity and store part of the electricity through the compressed air energy storage power station without shutting down the hydropower station. This solves the problem of shutdown of hydropower stations in the prior art caused by the inability to generate electricity and access the grid during the low load period of the power grid.

[0053] It can be seen that the present invention innovatively combines the compressed air energy storage power station and the hydropower project. The compressed air energy storage power station makes full use of the tail water of the river channel of the hydropower project and the abandoned temporary buildings and construction plant facilities, and shares its power transmission equipment and facilities and roads inside and outside the site, which brings many unexpected technical effects. It can effectively solve many problems in the construction and operation of compressed air energy storage power stations and hydropower projects in actual projects, and ensure the safe, stable and economical operation of the power system. Therefore, the present invention has broad guiding and popularization significance.

[0054] The following is a further description of a compressed air energy storage power station using the technical solution of the present invention as an example with reference to the accompanying drawings:

[0055] A compressed air energy storage power station utilizes an existing conventional hydropower station, and the installed capacity is determined to be 150MW based on the overall availability of the project and grid demand.

[0056] like Figure 1 to Figure 3 As shown in the figure, the compressed air energy storage power station includes a compression energy storage system 1, a heat storage and exchange system 2, a gas storage system 3, an expansion energy release system 4, a water supply system and cooling facilities 5, and other auxiliary systems 6. The heat storage and exchange system 2 mainly includes a heat exchanger 2.1, a normal temperature heat storage tank 2.2, and a high temperature heat storage tank 2.3. The gas storage system 3 adopts an underground gas storage reservoir with a capacity of 150,000 m 3 It is rebuilt from the abandoned diversion tunnel of a conventional hydropower station and is connected to the compression energy storage system 1, the normal temperature heat storage tank 2.2, the high temperature heat storage tank 2.3 and the expansion energy release system 4 through the heat exchanger 2.1.

[0057] The underground gas storage was rebuilt using the diversion tunnel, and the original lining was a 60cm thick reinforced concrete structure; the plug 3.1 at one end of the tunnel was a permanent plug installed on the upstream side when the diversion tunnel was blocked; the plug 3.2 at the other end of the tunnel was newly installed on the downstream side of the diversion tunnel, and was blocked with a 5m long reinforced concrete plug. The closed structure formed by the plugs at both ends and the middle section 3.3 of the tunnel was paved with a 60mm thick high-strength steel lining. Two charging and discharging pipes 3.4 and a maintenance channel 3.5 were buried in the plug 3.2 at the other end; the head of the charging and discharging pipe 3.4 was connected to the underground gas storage, and the tail was connected to the heat exchanger 2.1; the maintenance channel 3.5 was equipped with a sealed door with a width of 1.2m and a height of 1.8m to meet the requirements for the entry and exit of personnel, machinery and materials during maintenance, and was only opened when the underground gas storage needed to be inspected or repaired. The design gas storage pressure of the underground gas storage is determined to be 10 MPa according to the lining structure type and the overall conditions of the rock 12 surrounding the cave, which can simultaneously meet the safety and stability requirements of the lining structure and the rock 12 surrounding the cave.

[0058] The compression energy storage system 1, heat storage and exchange system 2, expansion energy release system 4, water supply system and cooling facilities 5, other auxiliary systems 6, etc. are built on the ground, using the energy dissipation building at the outlet of the diversion tunnel, as well as the sites and structures of the downstream construction plant facilities 9 such as the sand and gravel processing system, concrete production system, comprehensive processing and machinery repair plant, etc. The ground elevation is 1m higher than the highest flood level of the corresponding location of the conventional hydropower station. The water source of the water supply system and cooling facilities 5 is taken from the downstream river 13 of the conventional hydropower station.

[0059] The compressed air energy storage power station shares the switch station, transmission lines and other power transmission equipment and facilities 10 and the roads 11 inside and outside the field of the conventional hydropower station, and operates in conjunction with the conventional hydropower station to bundle and input or transmit electric energy. The electricity generated by the conventional hydropower station but not absorbed by the power grid is used for the compressed energy storage system 1, and the remaining insufficient electricity is used by the excess electricity of the power grid; when the power grid is insufficient, the conventional hydropower station will give priority to generating electricity and transmitting it, and the remaining insufficient electricity will be transmitted by the expansion energy release system 4.

[0060] By adopting the above technical solution disclosed in the present invention, the following beneficial effects are obtained:

[0061] The compressed air energy storage power station makes full use of the tailwater of the river channel of the hydropower project and the abandoned temporary buildings and construction plant facilities for layout, and shares its power transmission equipment and facilities and roads inside and outside the site. There is no need to separately expropriate land and resettle people and find other water sources, which can reduce the difficulty of construction, speed up project approval and construction progress, and save the construction and production management costs of exploration, civil engineering, equipment and facilities shared with the hydropower project; at the same time, the abandoned temporary buildings and construction plant facilities of the hydropower project are directly used as the gas storage and construction facilities of the compressed air energy storage power station, realizing the effective reuse of the abandoned temporary buildings and construction plant facilities, with a simple utilization method and low utilization cost, solving the problem of high construction and treatment costs; at the same time, through the joint operation of the compressed air energy storage power station and the hydropower project, the bundled delivery can greatly increase the power generation efficiency, improve the utilization rate of the delivery system, reduce the standby of the power system, and solve the shutdown problem caused by the inability of the hydropower station to generate electricity and access the Internet during the low load period of the power grid. The present invention effectively guarantees the safe, stable and economical operation of the power system, and has broad guiding and popularization significance.

[0062] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be considered as the scope of protection of the present invention.

Claims

1. A compressed air energy storage power station, characterized in that: The compressed air energy storage power station comprises a compressed energy storage system (1), a heat storage and exchange system (2), a gas storage system (3), an expansion energy release system (4), a water supply system and cooling facilities (5) and other auxiliary systems (6); the compressed air energy storage power station is constructed using temporary buildings (8), construction plant facilities (9), power transmission equipment facilities (10) and on-site roads (11) of a hydropower project (7); the installed capacity is determined comprehensively based on the overall availability of the hydropower project (7) and the demand of the power grid, and is operated in conjunction with the hydropower project (7).

2. A compressed air energy storage power station according to claim 1, characterized in that: The heat storage and exchange system (2) comprises a heat exchanger (2.1), a normal temperature heat storage tank (2.2) and a high temperature heat storage tank (2.3); The gas charging and discharging ends of the gas storage system (3) are respectively connected to one end of the normal temperature heat storage tank (2.2) and one end of the high temperature heat storage tank (2.3) through the heat exchanger (2.1); the other end of the normal temperature heat storage tank (2.2) is connected to the compression energy storage system (1); and the other end of the high temperature heat storage tank (2.3) is connected to the expansion energy release system (4).

3. A compressed air energy storage power station according to claim 2, characterized in that: The hydropower project (7) includes conventional hydropower stations and pumped storage power stations; The temporary buildings (8) include diversion tunnels, construction branch tunnels and exploration tunnels of the hydropower project (7); The construction plant facilities (9) include the sand and gravel processing system, concrete production system, concrete preheating and preheating system, compressed air system, water supply, power supply and communication system, and comprehensive processing and machinery repair plant of the hydropower project (7); The power transmission equipment and facilities (10) include a substation or a switch station and a transmission line of the hydropower project (7).

4. A compressed air energy storage power station according to claim 3, characterized in that: The gas storage system (3) adopts an underground gas storage reservoir, a ground gas storage tank, or a combination of an underground gas storage reservoir and a ground gas storage tank.

5. A compressed air energy storage power station according to claim 4, characterized in that: When the underground gas storage uses the diversion tunnel, the construction branch tunnel or the exploration tunnel, after the cavern has completed the corresponding use function in the hydropower project (7), the two ends of the cavern are sealed and rebuilt or expanded; The underground gas storage comprises a plug (3.1) at one end of the tunnel, a plug (3.2) at the other end of the tunnel and a middle section (3.3) of the tunnel, and is a high-pressure resistant concrete structure, a reinforced concrete structure or a steel-lined concrete structure; a charging and discharging pipe (3.4) and a maintenance passage (3.5) are buried in the plug (3.1) at one end of the tunnel or the plug (3.2) at the other end of the tunnel; the head and tail of the charging and discharging pipe (3.4) are respectively connected to the underground gas storage and the heat exchanger (2.1); the maintenance passage (3.5) is provided with a sealed door, the cross-sectional dimensions of which meet the requirements for the entry and exit of personnel, machinery and materials during maintenance, and is only opened when the underground gas storage needs to be inspected or repaired; The gas storage pressure range of the underground gas storage is 5MPa to 20MPa, and the design pressure is determined according to the lining structure type and the overall conditions of the rock (12) surrounding the cave, and should also meet the safety and stability requirements of the lining structure and the rock (12) surrounding the cave.

6. A compressed air energy storage power station according to claim 1, characterized in that: The compressed air energy storage power station, which is built on the ground using the temporary buildings (8) and the construction plant facilities (9), should be rebuilt after completing the corresponding functions in the hydropower project (7). The ground elevation should be higher than the highest flood level at the corresponding location of the hydropower project (7), and a safety overheight of not less than 1m should be reserved. When built on a soft foundation, sufficient settlement overheight should also be reserved according to the soft foundation properties and stress conditions.

7. A compressed air energy storage power station according to claim 1, characterized in that: The water source of the water supply system and cooling facilities (5) is taken from the downstream river (13) of the hydropower project (7).

8. A compressed air energy storage power station according to claim 1, characterized in that: The compressed air energy storage power station operates in conjunction with the hydropower project (7) to bundle and input or output electrical energy.

9. A compressed air energy storage power station according to claim 1, characterized in that: The combined operation mode of the compressed air energy storage power station and the hydropower project (7) is: When the hydropower project (7) is a conventional hydropower station, the compressed air energy storage power station and the conventional hydropower station are operated in a joint manner as follows: when the power grid has surplus electricity, the compressed energy storage system (1) first consumes the power generated by the conventional hydropower station (7.2), and the remaining surplus electricity of the power grid is used for the remaining surplus electricity; when the power grid is insufficient, the conventional hydropower station (7.2) generates electricity first and then transmits it, and the remaining insufficient electricity is transmitted by the expansion energy release system (4); When the hydropower project (7) is a pumped-storage power station, the compressed air energy storage power station and the pumped-storage power station are jointly operated in the following manner: the design efficiency and grid-connected electricity price of the compressed air energy storage power station and the pumped-storage power station are comprehensively analyzed, and the power station with better economic indicators is given priority in energy storage and power generation operation.

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