Auxiliary pressurizing reheating type compressed air energy storage system and method based on double-well structure hot salt well

Abstract

The invention discloses an auxiliary pressurizing reheating type compressed air energy storage system and method based on a double-well structure hot salt well. Usage of a heat storage device is eliminated, the situation that fuel is consumed for heating is avoided, and cost and pollution are reduced. The system comprises a progressive compression unit used for being connected with a motor for energy storage, the double-well structure hot salt well for gas storage, an expansion unit used for being connected with a power generator for energy releasing, and an auxiliary pressurizing reheating loop for expansion gas heating. The double-well structure hot salt well comprises two vertical wells and a horizontal well communicating with the two vertical wells from the bottom. A top end opening in one vertical well serves as a salt well gas storage inlet, and a top end opening in the other vertical well serves as a salt well exhaust outlet. The progressive compression unit comprises two levels of air compression units which are sequentially connected, and the power input end of at least one level of air compression unit is connected with the output end of the motor. An air outlet of the progressive compression unit is connected with the salt well gas storage inlet. The auxiliary pressurizing reheating loop comprises a heat exchanger and a pressurizing machine which are sequentially connected with air as acting media.

Description

technical field [0001] The invention relates to the technical field of physical energy storage, in particular to an auxiliary pressurized reheating compressed air energy storage system and method based on a hot salt well with a double well structure. Background technique [0002] With the development of society, the consumption of electric energy has increased sharply. In order to ensure the supply of electric energy in a clean and environmentally friendly manner, the development scale of various renewable energy sources has become larger and larger. At the same time, the inherent Random and volatility problems make it impossible to connect to the grid on a large scale, and the problem of peak load shifting and valley filling in the grid needs to be solved urgently. At present, the compressed air energy storage technology, which is favored both at home and abroad to solve these problems, is difficult to put into use on a large scale because of its low system efficiency and h...

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Problems solved by technology

[0002] With the development of society, the consumption of electric energy has increased sharply. In order to ensure the supply of electric energy in a clean and environmentally friendly manner, the development scale of various renewable energy sources has become larger and larger. At the same time, the inherent Randomness and volatility make it impossible to connect to the grid on a large scale, and the problem of peak-shaving and valley-filling of the power grid also needs to be solved urgently

At present, the compressed air energy storage technology, which is widely used to solve these problems, is unanimously optimistic at home and abroad, but it is difficult to put it into large-scale use because of its low system efficiency and high power generation costs.

Compressed air energy storage is to use a series of compressor units with multiple adiabatic compressors with interstage coolers to convert electrical energy into pressure energy of high-pressure air for energy storage, which is the process of compressed air energy storage. In the process of adiabatic compressed air About one-third of the electricity is converted into heat of compression, and this part of the heat energy is converted into low-grade heat through interstage cooling; the compressed air stored at high pressure needs to be heated during the process of releasing energy for power generation, even if the heat of compression is converted into a heat accumulator It can be stored and utilized, but due to the low grade of heat energy, it not only has little effect on improving the efficiency of the energy storage system, but also greatly increases the system investment due to the use of heat storage devices and heat recovery devices, making the energy storage system worthless

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