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

Claim 20:
21. A system 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 the form of pressure and heat, for future use in assisting with a production of electricity, the system comprising:
a first reservoir system containing a quantity of a first thermal storage medium, the first thermal storage medium including at least one of sand, rocks, manufactured granular material including at least one of ceramic pebbles, or a mixture of manufactured granular material, sand, and rocks, and being configured to be heated during a charge operation;
a second reservoir system containing a quantity of a second thermal storage medium, the second thermal storage medium including at least one of molten salt, sand, rocks, manufactured granular material including ceramic pebbles or a mixture of manufactured granular material, sand, and rocks, for storing heat;
an oxy-combustion furnace for heating the first thermal storage medium during the charge operation using oxygen (O2), and at least one of natural gas, coal, coke, petroleum, petroleum coke, tires, solid waste, biomass, or the electricity supplied from the power grid or the power plant;
a discharge subsystem including:
a primary heat exchanger having a first input, and first and second outputs, the primary heat exchanger configured to receive heated CO2 from the first reservoir system during a discharge operation of the system and to generate a second quantity of supercritical CO2 (sCO2) at a second temperature and a second pressure, at the second output thereof;
a secondary heat exchanger, located upstream of the primary heat exchanger, and which operates in series with the primary heat exchanger, having a second input configured to receive a heat-transfer fluid from the second reservoir system during the discharge operation of the system to generate a first quantity of supercritical CO2 (sCO2) at a first temperature, the first temperature being lower than the second temperature, and at a first pressure, the first pressure being substantially the same as the second pressure, at a first output thereof;
a Brayton-cycle turbine for receiving the second quantity of sCO2 from the second output of the primary heat exchanger and generating electricity therefrom at a first output thereof for transmission to the power grid, the Brayton-cycle turbine also configured to produce a third quantity of sCO2 having a third temperature and a third pressure at a second output thereof, the third temperature and the third pressure each being lower than the second temperature and the second pressure; and
a recuperator subsystem for circulating the third quantity of sCO2 to reheat and re-pressurize the third quantity of sCO2 to create a re-heated and re-pressurized third quantity of sCO2, for reapplication to the secondary heat exchanger, to be further reheated by the secondary heat exchanger for reapplication to the primary heat exchanger, and to be subsequently further reheated by the primary heat exchanger and then output therefrom to the Brayton-cycle turbine to further assist in powering the Brayton-cycle turbine.