Thermal energy storage system for use with a low temperature heat source and a thermal power cycle system
AssigneeRondo Energy, Inc.
InventorsYusef Desjardins Ferhani, John Setel O'Donnell
Life of this patent
Estimating the term…
Abstract
An energy storage system converts variable renewable electricity (VRE) to continuous heat at over 1000° C. Intermittent electrical energy heats a solid medium. Heat from the solid medium is delivered continuously on demand. Heat delivery via flowing gas establishes a thermocline which maintains high outlet temperature throughout discharge. The delivered heat which may be used for processes including power generation and cogeneration. In one application, the energy storage system provides higher-temperature heat to a conventional lower-temperature heat source to boost the temperature of a thermal power cycle working fluid to a turbine, thereby increasing efficiency of the power cycle.
Claims24
A geothermal power generation system, including:
- a condenser producing liquid water;
- a feedwater pump configured to raise a pressure of at least a portion of the liquid water;
- a separator configured to receive a geothermal reservoir flow and to produce a flash steam at a first pressure;
- a thermal energy storage (TES) system with a heat exchanger having one portion configured to heat the liquid water from the feedwater pump to produce a high-pressure motive steam;
- a thermal vapor compressor fluidly coupled to the separator and the TES, the thermal vapor compressor configured to entrain the flash steam with the motive steam and to discharge a combined steam at an intermediate pressure and temperature;
- the heat exchanger including another portion configured to receive the combined steam and to further heat the combined steam to a superheated steam;
- and
- a steam turbine configured to receive the superheated steam and to exhaust to the condenser.
A geothermal power generation system, including:
- a separator configured to receive a geothermal reservoir flow and to discharge (i) flash steam at a first pressure and (ii) saturated geothermal liquid;
- a feedwater (FW) pump;
- a geothermal-to-FW preheater arranged to transfer heat from the saturated geothermal liquid to a FW stream to produce a preheated FW;
- a thermal energy storage (TES) heat-exchange system fluidly coupled to receive the preheated FW and to heat the preheated FW to a motive steam at a second pressure greater than the first pressure;
- a thermal vapor compressor configured to entrain the flash steam with the motive steam and to discharge a combined stream flow having an intermediate pressure and a temperature elevated by thermocompression;
- and
- a steam turbine configured to receive the combined stream flow and to exhaust to a condenser.
A retrofit kit for upgrading an existing, single-flash geothermal plant including a separator, a turbine, a condenser, and a feedwater (FW) pump, the kit including:
- a geothermal-to-FW preheater sized to extract heat from saturated geothermal liquid downstream of the separator;
- a TES heat-exchange system configured to accept preheated FW and deliver motive steam;
- a thermal vapor compressor configured to entrain plant flash steam with the motive steam to produce a thermocompressed, superheated discharge for the turbine;
- and
- piping and controls to integrate the preheater, TES, and thermal vapor compressor with the existing geothermal plant while configured to maintain substantially the same separator pressure and condenser operation.
Dependencies are inferred from the claim text.