THERMOELECTRIC ENERGY STORAGE SYSTEM WITH AN INTERMEDIATE STORAGE TANK AND METHOD FOR STORING THERMOELECTRIC ENERGY

摘要

A system and method are provided for storing electric energy in the form of thermal energy. A thermoelectric energy storage system includes a working fluid circuit for circulating a working fluid through a heat exchanger, and a thermal storage medium circuit for circulating a thermal storage medium. The thermal storage medium circuit includes at least one hot storage tank, an intermediate temperature storage tank, and a cold storage tank connected together via the heat exchanger. A proportion of the storage medium is redirected to or from the intermediate storage tank from or to the hot or cold storage tank, joining another proportion which flows directly between the cold and hot storage tank.

主权项

1. A thermoelectric energy storage system having a charging cycle for providing thermal energy to a thermal storage, and a discharging cycle for generating electricity by retrieving the thermal energy from the thermal storage, the thermoelectric energy storage system comprising:
a working fluid circuit for circulating a working fluid through a heat exchanger, the working fluid undergoing a transcritical process during heat transfer in the heat exchanger; a thermal storage medium circuit for circulating a thermal storage medium, the thermal storage medium circuit having at least one hot storage tank, one intermediate temperature storage tank and one cold storage tank connected together via the heat exchanger, wherein the system is configured to modify a rate of flow of the thermal storage medium in the heat exchanger by variation in the input rate of flow of thermal storage medium to the intermediate storage tank, and by variation in the output rate of flow of thermal storage medium from the intermediate storage tank.