High-efficiency afterburning type compressed air energy storage system

Abstract

The invention discloses a high-efficiency afterburning type compressed air energy storage system. The high-efficiency afterburning type compressed air energy storage system comprises an electric energy storage system and an electric energy release system, wherein the electric energy storage system comprises a plurality of air compression units, a first heat exchanger, an air storage space and an energy storage system heat storage tank, and the electric energy release system comprises a plurality of combustors, a combustor air supply system, a plurality of second heat exchangers, a plurality ofexpansion machine units, an energy storage system waste-heat recycling heat exchanger, a gas mixing device and a generator. According to the high-efficiency afterburning type compressed air energy storage system, the compressed air required by the combustor is the pressured exhaust gas of an expansion machine unit, the pressured exhaust gas of the expansion machine unit is subjected to partial work for recycling part of energy, and the fuel consumption is reduced. The gas mixing device mixes pressured flue gas with the pressured exhaust gas of the expansion machine unit, the mixed gas entersthe expansion machine unit to work for recycling flue gas heat and pressure energy, waste heat is reused by the energy storage system, and the heat of bearing lubricating oil of devices such as the air compression units, the expansion machine unit and the engine are recycled, so that the efficiency of the energy storage system is greatly improved.

Description

technical field [0001] The invention relates to the field of electric energy storage, and is specifically used for large-scale energy storage of power grid electric energy to realize peak-shaving and valley-filling of power grid loads, and can also be used for high-efficiency supplementary combustion compressed air storage for new energy electric energy grid connection and large-scale storage of electric energy. energy system. Background technique [0002] Compressed air energy storage technology is a large-scale physical energy storage technology. When the power grid is in a low load period, the cheap electric energy during the valley period is used to drive the air compressor unit to do work, and the cheap low-valley electric energy is converted into the pressure energy of compressed air for storage. When the power grid is at the peak of power consumption, the high-pressure compressed air in the storage tank is released. After passing through the heat exchanger or burner t...

AI Technical Summary

Problems solved by technology

[0003] The existing compressed air energy storage technology is divided into two categories, one is the non-supplementary combustion compressed air energy storage technology, in the process of electric energy storage, the electric energy is converted into the pressure energy of compressed air for storage, and the compressor unit generated in this process The exhaust temperature is not high, and the exhaust temperature is usually lower than 150°C, so that the inlet airflow entering the air expander unit can be heated at a lower temperature, which limits the ability of the compressed air to do external work; in addition, it is necessary to configure a large-capacity heat accumulator to To store low-grade compression heat, the cost of heat accumulator hardware facilities is high, which increases the hardware investment cost of compressed air energy storage system

[0004] The second is the post-combustion compressed air energy storage technology. In the process of releasing compressed air to perform work, a burner is installed at the entrance of each stage of the air expander unit. The equipment investment cost is too high. The entrance of the first stage air expander unit The pressure is high, the fuel is directly mixed with high-pressure air under high pressure, and the high-pressure high-temperature flue gas directly enters the first expander unit. This type of burner needs to be burned in a high-pressure environment. Domestic high-pressure combustion The burner technology is immature, and a burner is installed at the inlet of each air expander, resulting in excessive natural gas consumption, resulting in excessively high exhaust gas temperature of the last air expander, and reducing the efficiency of the entire compressed air energy storage system

[0005] In addition, the air required for the combustion of the pressurized burner in the existing post-combustion compressed air energy storage system directly uses the compressed air stored in the gas storage space, and the high-pressure air in the gas storage space is throttled down to the pressure required by the burner. The depressurized air is supplied to the burner for combustion. However, this method has a large air throttling pressure loss. At the same time, the temperature of the compressed air in the air storage space is low, that is, the temperature of the air supplied to the burner is low, which increases the temperature of the burner. fuel consumption

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