An aircraft propulsion system includes a primary energy conversion device that uses a cryogenic fuel and air to generate power and thermal energy, a bottoming cycle where a working fluid is circulated within a closed circuit that includes a bottoming compressor section and a bottoming turbine section, the working fluid is compressed in the bottoming compressor section and expanded through the bottoming turbine section to generate shaft power, a thermal transfer circuit that includes a thermal routing fluid, the thermal routing fluid is different than the working fluid, thermal transfer heat exchanger where thermal energy from the thermal routing fluid is communicated to the working fluid, and a primary heat exchanger where thermal energy from the primary energy conversion device is communicated to the thermal routing fluid.

Rankine Cycle power generation facility having a plurality of thermal inputs and at least one heat sink, where the heat sink includes a thermal chimney or a natural convective cooling tower. In a preferred embodiment, the power facility generates electricity and/or fresh water with a zero carbon footprint, such as by using a combination of solar and geothermal heating to drive a Rankine Cycle heat engine. In one embodiment, a thermal stack is mounted in the base of the thermal chimney, the thermal stack for using waste heat from the plurality of thermal inputs to drive a natural convective flow of air in the thermal chimney, the convective flow having sufficient momentum to drive additional power generation in an air turbine mounted in the chimney and to drive an evaporative cycle for concentratively extracting fresh water from geothermal brines.

Rankine Cycle power generation facility having a plurality of thermal inputs and at least one heat sink, where the heat sink includes a thermal chimney or a natural convective cooling tower. In a preferred embodiment, the power facility generates electricity and/or fresh water with a zero carbon footprint, such as by using a combination of solar and geothermal heating to drive a Rankine Cycle heat engine. In one embodiment, a thermal stack is mounted in the base of the thermal chimney, the thermal stack for using waste heat from the plurality of thermal inputs to drive a natural convective flow of air in the thermal chimney, the convective flow having sufficient momentum to drive additional power generation in an air turbine mounted in the chimney and to drive an evaporative cycle for concentratively extracting fresh water from geothermal brines.

Methods and systems of power generation that integrate SCO.sub.2 Brayton and Rankin steam power cycles with fossil fuel combustion, One such method involves combusting a fuel material with an oxidizer material in a combustor to produce heat and a combustion exhaust. At least a portion of the combustion exhaust and a first portion of heat produced by the combustion processing are fed to a SCO.sub.2 Brayton power cycle to produce power and a second exhaust. At least a portion of the second exhaust and a second portion of heat produced by the combustion processing are feed to a steam Rankine power cycle to produce additional power and a third exhaust.

Methods and systems for low emission power generation in combined cycle power plants are provided. One system includes a gas turbine system that stoichiometrically combusts a fuel and an oxidant in the presence of a compressed recycle stream to provide mechanical power and a gaseous exhaust. The compressed recycle stream acts as a diluent to moderate the temperature of the combustion process. A boost compressor can boost the pressure of the gaseous exhaust before being compressed into the compressed recycle stream. A purge stream is tapped off from the compressed recycle stream and directed to a C0.sub.2 separator which discharges C0.sub.2 and a nitrogen-rich gas which can be expanded in a gas expander to generate additional mechanical power.

Methods and systems for low emission power generation in hydrocarbon recovery processes are provided. One system includes a gas turbine system configured to stoichiometrically combust a compressed oxidant derived from enriched air and a fuel in the presence of a compressed recycle exhaust gas and expand the discharge in an expander to generate a recycle exhaust stream and drive a main compressor. A boost compressor receives and increases the pressure of the recycle exhaust stream and prior to being compressed in a compressor configured to generate the compressed recycle exhaust gas. To promote the stoichiometric combustion of the fuel and increase the CO.sub.2 content in the recycle exhaust gas, the enriched air can have an increased oxygen concentration.

A method of power production using a high pressure/low pressure ratio Brayton Power cycle with predominantly N.sub.2 mixed with CO.sub.2 and H.sub.2O combustion products as the working fluid is provided. The high pressure can be in the range 80 bar to 500 bar. The pressure ratio can be in the range 1.5 to 10. The natural gas fuel can be burned in a first high pressure combustor with a near stoichiometric quantity of pressurised preheated air and the net combustion gas can be mixed with a heated high pressure recycle N.sub.2+CO.sub.2+H.sub.2O stream which moderates the mixed gas temperature to the value required for the maximum inlet temperature to a first power turbine producing shaft power.

A system including: (i) a pumped-heat energy storage system (PHES system), wherein the PHES system is operable in a charge mode to convert electricity into stored thermal energy in a hot thermal storage (HTS) medium; (ii) an electric heater in thermal contact with the hot HTS medium, wherein the electric heater is operable to heat the hot HTS medium above a temperature achievable by transferring heat from a working fluid to a warm HTS medium in a thermodynamic cycle.

The present disclosure relates to a power generation system and related methods that use supercritical fluids, whereby a portion of the supercritical fluid is recuperated.

The present disclosure relates to a power generation system and related methods that use supercritical fluids, whereby a portion of the supercritical fluid is recuperated.