Abstract: Thermal management systems include an open circuit refrigeration system featuring a first receiver configured to store a gas, a second receiver configured to store a liquid refrigerant fluid, an evaporator configured to extract heat from a heat load that contacts the evaporator, and an exhaust line, where the first receiver, the second receiver, the evaporator, and the exhaust line are connected to provide a refrigerant fluid flow path.

Abstract: A thermal management system is described. The thermal management system includes an open circuit refrigeration circuit that has a refrigerant fluid flow path, with the refrigerant fluid flow path including a receiver configured to store a refrigerant fluid, an ejector having a primary flow inlet configured to receive refrigerant, a liquid separator, an evaporator configured to extract heat from a heat load that contacts the evaporator, with the evaporator coupled to the ejector and the liquid separator, and an exhaust line coupled to a vapor side outlet of the liquid separator. In operation, the evaporator in the open circuit refrigeration circuit would be coupled to a heat load.

Abstract: A thermal management system includes an open circuit refrigeration circuit that has a refrigerant fluid flow path, with the refrigerant fluid flow path including a receiver configured to store a refrigerant fluid, a first control device configured to receive refrigerant from the receiver, a liquid separator, and an evaporator configured to extract heat from a heat load that contacts the evaporator, with the evaporator coupled to the first control device and the liquid separator. The system includes a pump having an inlet and an outlet, with the outlet of the pump coupled to the liquid side outlet of the liquid separator and a second control device that is coupled to an exhaust line, that is coupled to the vapor side outlet of the liquid separator through the second control device. In operation, the evaporator in the open circuit refrigeration circuit would be coupled to a heat load.

Abstract: A thermal management system includes an open circuit refrigeration circuit that has a refrigerant fluid flow path, with the refrigerant fluid flow path including a receiver configured to store a refrigerant fluid, a first control device configured to receive refrigerant from the receiver, a liquid separator, and an evaporator configured to extract heat from a heat load that contacts the evaporator, with the evaporator coupled to the first control device and the liquid separator. The system includes a pump having an inlet and an outlet, with the outlet of the pump coupled to the liquid side outlet of the liquid separator and a second control device that is coupled to an exhaust line, that is coupled to the vapor side outlet of the liquid separator through the second control device. In operation, the evaporator in the open circuit refrigeration circuit would be coupled to a heat load.

Abstract: A cooling system includes a first heat exchanger for cooling a refrigerant, an expander configured to receive the refrigerant from the first heat exchanger at least one compressor configured to compress the refrigerant, an ejector configured to receive the refrigerant from the expander as a motive stream that evacuates and compresses the refrigerant from an evaporator, and a liquid separator coupled to an output of the ejector and configured to provide liquid refrigerant to an evaporator loop and vapor refrigerant to the at least one compressor. The evaporator loop includes an expansion device positioned to expand the liquid refrigerant from the liquid separator, and the evaporator configured to receive the refrigerant from the expansion device, heat the refrigerant from a heat load, and pass the refrigerant to the ejector.

Abstract: A gas turbine engine includes a first shaft coupled to a first turbine and a first compressor, a second shaft coupled to a second turbine and a second compressor, and a third shaft coupled to a third turbine and a fan assembly. The turbine engine includes a heat rejection heat exchanger configured to reject heat from a closed loop system with air passed from the fan assembly, and a combustor positioned to receive compressed air from the second compressor as a core stream. The closed-loop system includes the first, second, and third turbines and the first compressor and receives energy input from the combustor.

Abstract: An aircraft power and propulsion system includes an air compressor, a heat rejection heat exchanger, a combustor positioned to receive compressed air from the air compressor as a core stream and provide thrust to the aircraft, and a closed-loop s-CO2 system. The closed-loop s-CO2 system includes carbon dioxide as a working fluid, receives power from the combustor, and rejects heat via the heat rejection heat exchanger to a cooling stream. The closed-loop system s-CO2 configured to provide power to a fan that provides the cooling stream and thrust, and power to the air compressor and at least one auxiliary load.

Abstract: A power and propulsion system includes an air compressor, a combustor positioned to receive compressed air from the air compressor as a core stream, and a closed-loop system having carbon dioxide as a working fluid that receives heat from the combustor and rejects heat to a cooling stream. The closed-loop system configured to provide power to a fan that provides the cooling stream, and to one or more distributed propulsors that provide thrust to an aircraft.

Abstract: A gas turbine engine includes a shaft comprising a first compressor, a fan assembly, and a power circuit that provides power to the shaft in a closed-loop system. An inner housing houses at least a portion of the shaft, the first compressor for compressing a core stream of air, and a combustor. A baffle encloses a portion of the inner housing and forms a first air passageway therebetween. A nacelle encloses a portion of the baffle and forms a second air passageway therebetween. A heat exchanger is positioned in the second air passageway that rejects heat from the power circuit into a heat rejection stream of air passing through the second air passageway. Air is accelerated as streams in parallel and via the fan assembly as the core stream into the inner housing, as a bypass flow stream of air through the first volume, and as the heat rejection stream.

Abstract: A gas turbine engine may include a deep heat recovery system, such as a deep heat recovery super critical carbon dioxide (sCO2) system. The deep heat recovery system may include two-stage cooling of the working fluid (such as carbon dioxide—CO2) where at least one of cooling stages is recuperative by transferring heat from the working fluid to a flow of compressed air being supplied to a combustor included in the gas turbine engine. The deep heat recovery system may operate in a supercritical cycle, or in a transcritical cycle depending on the temperature to which the working fluid is cooled during a second stage of the two-stage cooling. The second stage of the two-stage cooling includes working fluid-to-air heat rejection where the air is ambient air.

Abstract: A cooling system includes a main refrigerant circuit that includes a compressor, a heat rejection heat exchanger, one of an expander and an expansion device, at least one evaporator coupled to a thermal load, and a suction accumulator. A charge management circuit includes a charge management receiver configured in parallel with the compressor and the heat rejection heat exchanger. A controller is configured to accumulate and discharge reserve refrigerant to and from the charge management receiver to provide flexibility in system operation as refrigerant in the main refrigerant circuit operates in sub-critical, trans-critical, and super-critical modes of operation.

Abstract: A cooling system for an aircraft includes an air intake, an expansion device, and an evaporator. A first heat exchanger receives air passing into the air intake when the aircraft is operating at elevation, and receives the refrigerant from a first compressor at a first pressure. A second compressor receives the refrigerant from the first heat exchanger and compresses the refrigerant to a second pressure that is greater than the first pressure. A second heat exchanger receives the refrigerant from the second compressor. The first and second compressors are configured the first and second compressors are configured to operate at pressures that avoid temperature differences between the refrigerant and the air within each of the first and second heat exchangers below a set restriction.

Abstract: A cooling system includes a heat exchanger through which a refrigerant flows, the heat exchanger having a fluid passing therethrough such that heat is rejected to the fluid, an evaporator, a refrigerant piping split point that receives the refrigerant at a given pressure from the heat exchanger and splits the refrigerant flow into a first circuit and a second circuit, the first circuit having an expansion valve that receives the refrigerant at the given pressure, and the second circuit having a first turbine coupled to a first compressor, wherein the first turbine receives the refrigerant at the given pressure, and a set of valves arranged to direct the refrigerant through the first circuit, the second circuit, or both the first and second circuits based on ambient conditions of the cooling system.

Abstract: A thermal management system includes a closed dynamic cooling circuit, and a closed first steady-state cooling circuit. Each circuit has its own compressor, heat rejection exchanger, and expansion device. A thermal energy storage (TES) system is configured to receive a dynamic load and thermally couple the dynamic cooling circuit and the first steady-state cooling circuit. The dynamic cooling circuit is configured to cool the TES to fully absorb thermal energy received by the TES when a dynamic thermal load is ON, and the steady-state cooling circuit is configured to cool the TES when the dynamic thermal load is OFF.

Abstract: An apparatus, system, and method for a gas turbine engine may include a sectioned heat exchanger. A heat exchanger may include an inlet manifold configured to receive a working fluid. A plurality of circuits including at least first and second circuits configured to transfer heat with respect to the working fluid. Each of the circuits may have a circuit inlet valve, a circuit heat exchange channel, and a circuit outlet valve. The heat exchanger may further include an outlet manifold configured to pass the working fluid to an outlet. The heat exchanger may include a first sensor configured to measure of first parameter of the first circuit and a second sensor configured to measure a second parameter of at least one of the outlet and the second circuit. A controller may be configured to selectively isolate at least one of the plurality of circuits based on a pressure difference between the first and second parameters.

Abstract: A gas turbine engine includes a first shaft coupled to a first turbine and a first compressor, a second shaft coupled to a second turbine and a second compressor, and a third shaft coupled to a third turbine and a fan assembly. The turbine engine includes a heat rejection heat exchanger configured to reject heat from a closed loop system with air passed from the fan assembly, and a combustor positioned to receive compressed air from the second compressor as a core stream. The closed-loop system includes the first, second, and third turbines and the first compressor and receives energy input from the combustor.

Abstract: A gas turbine engine includes a first shaft coupled to a first turbine and a first compressor, a second shaft coupled to a second turbine and a second compressor, and a third shaft coupled to a third turbine and a fan assembly. The turbine engine includes a heat rejection heat exchanger configured to reject heat from a closed loop system with air passed from the fan assembly, and a combustor positioned to receive compressed air from the second compressor as a core stream. The closed-loop system includes the first, second, and third turbines and the first compressor and receives energy input from the combustor.

Abstract: A thermal management system includes a closed dynamic cooling circuit, and a closed first steady-state cooling circuit. Each circuit has its own compressor, heat rejection exchanger, and expansion device. A thermal energy storage (TES) system is configured to receive a dynamic load and thermally couple the dynamic cooling circuit and the first steady-state cooling circuit. The dynamic cooling circuit is configured to cool the TES to fully absorb thermal energy received by the TES when a dynamic thermal load is ON, and the steady-state cooling circuit is configured to cool the TES when the dynamic thermal load is OFF.

Abstract: A gas turbine engine includes a shaft having a first air compressor coupled thereto, a combustor positioned to receive compressed air from the first compressor, and a power source coupled to the shaft, the power source powered by a working fluid other than the compressed air.

Abstract: A gas turbine engine may include a deep heat recovery system, such as a deep heat recovery super critical carbon dioxide (sCO2) system. The deep heat recovery system may include two-stage cooling of the working fluid (such as carbon dioxide—CO2) where at least one of cooling stages is recuperative by transferring heat from the working fluid to a flow of compressed air being supplied to a combustor included in the gas turbine engine. The deep heat recovery system may operate in a supercritical cycle, or in a transcritical cycle depending on the temperature to which the working fluid is cooled during a second stage of the two-stage cooling. The second stage of the two-stage cooling includes working fluid-to-air heat rejection where the air is ambient air.