Method and system for accumulating energy by compressed air and heat accumulation medium simultaneously

Abstract

The invention relates to a method and a system for accumulating energy by compressed air and heat accumulation medium simultaneously, and belongs to the field of compressed air energy accumulating. The system comprises a motor, an air compressor, an air storage device, a heat accumulation tin, a turbine and an electric generator. The system comprises the following principles: solid heat accumulation medium and electrical heating elements are arranged in the heat accumulation tin; when the system is charged in off-peak hour period, air is compressed by the air compressor and exchanges heat with the solid heat accumulation medium in the heat accumulation tin; the heat exchanged air is stored in the air accumulation device; the heat exchanged solid heat accumulation medium is heated continuously by using the electrical heating elements; when the system discharges in peak hour period, the accumulated air is released, and enters the turbine to work after absorbing the heat from the solid heat accumulation medium; and the electric generator is driven by the turbine to generate electricity. Compared with the conventional adiabatic compression air energy accumulating system, the system has the advantages that the memory capacity is greatly increased; the unit capacity investment cost is reduced; the system only needs to adopt a one-stage heat accumulation tin and a one-stage turbine; and the system complex degree is low.

Description

technical field [0001] The invention relates to a method and system for simultaneously storing energy by using compressed air and a heat storage medium, and belongs to the technical field of compressed air energy storage. Background technique [0002] At present, the development of renewable energy including wind energy and solar energy has drawn increasing attention to energy storage technology. A major problem with renewable energy is its instability. External climate conditions at different times will cause large fluctuations in power generation, which has a great negative impact on grid-connected operation or matching with user needs. Therefore, it is crucial to develop appropriate energy storage technology to adjust the power generation at different times to meet the needs of grid connection or users. [0003] Among the current common energy storage technologies, compressed air energy storage technology has great development potential. Its storage capacity is equivalen...

AI Technical Summary

Problems solved by technology

However, due to the introduction of heat storage tanks, the adiabatic compressed air energy storage system is more complicated, and the initial investment cost is 20-30% higher than that of the non-adiabatic compressed air energy storage system, which limits its application and promotion.

Moreover, due to the limitations of current compressor materials, the air temperature at the outlet of the air compressor is not high, which limits the heat storage potential of the heat storage medium in the heat storage tank

In addition, the turbine inlet temperature will also be limited, which means that when the air storage pressure is high, condensation may occur at the turbine outlet, and it is necessary to increase the turbine outlet pressure or use a two-stage heat storage tank and two Turbine, increasing the outlet pressure of the turbine will lead to a decrease in system efficiency, and the use of two-stage heat storage tanks and two-stage turbines will significantly increase the complexity of the system

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