Compressed air energy storage technology is a potential development direction of large-scale energy storage technology

The salt cavern gas storage has great cost and performance advantages, which can make use of the huge salt caverns, i.e. the mine holes left after salt mining; The construction of salt cavern storage for energy storage such as compressed air, natural gas, oil and hydrogen is a common method in many countries in the world. Salt cavern gas storage is a technology that uses artificial methods to create cavern space to store gas in the thicker salt rock or salt dome underground. The salt cavern gas storage is generally constructed by solution mining, and its depth, capacity, spacing, pressure and other parameters are determined according to different terrain and geological conditions. As an excellent large-scale gas storage method, salt cavern gas storage can be fully combined with compressed air energy storage system to solve the large capacity gas storage problem of large-scale compressed air energy storage power stations.

The underground salt cavern as the gas storage of the compressed air energy storage system has many advantages:

1) Low construction cost; 2) Small floor area; 3) Mature technology; 4) Good sealing performance; 5) High gas storage pressure; 6) Safe and stable.

Energy storage process: drive the compressor with low valley power, abandoned wind power and abandoned photoelectric power, compress the air to high pressure through two-stage compression and store it in the underground salt cavern. At the same time, the compression heat generated in the compression process is recovered by the regenerative system and the compressor is cooled to complete the storage of compression heat energy. In this process, the electric energy is decoupled and converted into the pressure potential energy and compression heat energy of high-pressure air to realize the decoupled storage of electric energy.

Energy release process: high-pressure air is released from the salt cavern gas storage, heated by the heat stored in the regenerative system, and then enters the primary turbine for expansion. After the first stage expansion, the pressure and temperature of the air are reduced, and the air needs to be heated again by the heat stored in the heat storage system, and then enters the second stage turbine for work to complete the expansion power generation. In this process, the pressure potential energy and the compressed heat energy are coupled to drive the turbine to generate electricity, realizing the system's coupling energy release power generation.