Adiabatic compressed air energy storage system and corresponding method

Abstract

During operation of an adiabatic compressed air energy storage (ACAES) system (50), energy imbalances may arise between thermal energy storage (TES,60) in the (ACAES) system and the amount of thermal energy required to raise the temperature of a given volume of compressed air to a desired turbine entry temperature T i after the air has been discharged from compressed air storage (62) of the ACAES system (50). To at last partially redress such an energy imbalance it is proposed to selectively supply additional thermal energy to the given volume of compressed air after it has received thermal energy from the TES (60) and before it expands through the turbine (58). The additional thermal energy is supplied from a source external to the ACAES system, such as fuel burnt in a combustor (56). The amount of thermal energy added to the given volume of compressed air after it has received thermal energy from the TES is much smaller than the amount of useful work obtained from the given volume of compressed air by the turbine (58).

Description

technical field [0001] The present invention relates to the field of compressed air energy storage (CAES) systems, more particularly the invention relates to the energy balance of adiabatic CAES (ACAES) systems. Background technique [0002] CAES systems can be used to store large amounts of energy. During the "fill" phase of operation, when electricity demand is low, such as at night, when available online generation capacity exceeds demand, air is compressed to high pressure using an electric pump or compressor and stored into one or more large chambers chamber or cavity. During the "release" phase of the operation of the CAES system, during periods when there is a danger of electricity demand exceeding the grid's supply capacity, the stored compressed air is used to drive a turbine connected to a generator, thereby supplying electrical energy to the utility grid . A very relevant example of this application occurs in the field of electricity generation using renewable ...

AI Technical Summary

Problems solved by technology

However, disadvantages caused by this arrangement are, for example, increased capital costs due to the presence of heat exchangers and additional thermal energy storage units; increased pressure loss due to multi-stage compression and expansion; increased system complexity; and power while limiting the energy density of the system

[0006] Also, at high pressure and low temperature, depending on ambient conditions, moisture in the air may condense in (each) thermal energy storage unit

This condensation causes the TES to be cooled and part of its thermal energy is lost thus occurring

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