Patent ID: 11873740
Assignee: LAWRENCE LIVERMORE NATIONAL SECURITY, LLC
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F  H  Y | IPC F  H

Claim 17:
18. A method for storing and time-shifting at least one of excess electrical power from an electrical power grid, excess electrical power from a power plant, or heat from a heat generating source, in a form of pressure and heat, for future use in assisting with a production of electricity, the method comprising:
using a reservoir to contain a quantity of a thermal storage medium, the thermal storage medium including at least one of sand, rocks, manufactured granular material including ceramic pebbles, or a mixture of manufactured granular material, sand, and rocks;
feeding a furnace, operably associated with the reservoir, with a combustible fuel source to heat the thermal storage medium during a charge phase of operation;
performing a discharge operation including:
using a heat exchanger having a first input configured to receive heated CO2 from the reservoir during the discharge operation to generate a first quantity of supercritical CO2 (sCO2) at a first temperature and a first pressure, at a first output thereof;
using a Brayton-cycle turbine to receive the first quantity of sCO2 from the first output of the heat exchanger and to generate electricity therefrom at a first output thereof for transmission to the power grid;
using the Brayton-cycle turbine to also produce a second quantity of sCO2 having a second temperature and a second pressure at a second output thereof, the second temperature and the second pressure each being lower than the first temperature and the first pressure;
using a recuperator subsystem to circulate the second quantity of sCO2 to reheat and re-pressurize the second quantity of sCO2 to create a third quantity of sCO2;
feeding the third quantity of sCO2 to the heat exchanger to be further reheated by the heat exchanger to create a re-heated third quantity of sCO2 similar in temperature and pressure to the first quantity of sCO2; and
feeding the re-heated third quantity of sCO2 to the Brayton-cycle turbine to further assist in powering the Brayton-cycle turbine.