A gas turbine engine has a compressor section, a combustor, and a turbine section. An associated fluid is to be cooled and an associated fluid is to be heated. A transcritical vapor cycle heats the fluid to be heated, and cools the fluid to be cooled. The transcritical vapor cycle includes a gas cooler in which the fluid to be heated is heated by a refrigerant in the transcritical vapor cycle. An evaporator heat exchanger at which the fluid to be cooled is cooled by the refrigerant in the transcritical vapor cycle. A compressor upstream of the gas cooler compresses the refrigerant to a pressure above a critical point for the refrigerant. An expansion device expands the refrigerant downstream of the gas cooler, with the evaporator heat exchanger being downstream of the expansion device, and such that the refrigerant passing through the gas cooler to heat the fluid to be heated is generally above the critical point.

Thermal management techniques include: transporting a refrigerant fluid from a receiver to an inlet of a flash tank that has a vapor-side outlet and liquid-side outlet such that a liquid phase of the refrigerant fluid moves to a bottom of the flash tank and outputs from the liquid-side outlet; forming a solid-vapor state from the liquid phase by expanding the liquid phase with an expansion valve to a first pressure that is less than a triple point pressure to form a solid-vapor mixture of the refrigerant fluid; extracting heat from a heat load with an evaporator that receives the solid-vapor mixture of the refrigerant fluid and sublimates the solid state of the solid-vapor mixture of the refrigerant fluid directly into a vapor phase of the refrigerant fluid; and discharging, from an exhaust line, the vapor phase to an ambient environment without returning the vapor phase to the receiver.

An evaporatively cooled refrigeration system includes a refrigerant, a gas/liquid separator, an expansion valve in fluid connection to the gas/liquid separator, an evaporator to receive the refrigerant from the expansion valve, a compressor configured to compress the refrigerant in fluid connection to the evaporator, and a gas cooler in fluid connection to the compressor. The gas cooler includes an indirect heat exchanger to convey the refrigerant and facilitate heat from the refrigerant and a spray system to spray an evaporative coolant on the indirect heat exchanger. Evaporative cooling provided by the evaporative coolant on the coil is configured to cool the refrigerant below a dry bulb ambient air temperature.

Secondary loop air conditioning and heat pump systems include a reservoir with a capsule holding a phase change material.

The invention relates to a flow circuit system (1) for a vehicle, with a first flow circuit (10) guiding a first fluid and operable as a heat pump, and a second flow circuit (50) with a conveying device (31) guiding a second fluid, and a switching device (35), wherein in the provided flow direction of the first fluid downstream of a compressor (3) and upstream of an expansion element (15), at least one first heat exchanger (7) between the first and second fluids, wherein the second flow circuit (50) has at least two flow circuit modes, wherein in the first flow circuit mode, apart from the at least one conveying device (31) for the second fluid and the at least one first heat exchanger (7), at least one outside heat exchanger (37) which may be flowed through by the second fluid and is configured as a radiator is connected to the second flow circuit (50), and in the second flow circuit mode this at least one outside heat exchanger (37) is not connected to the at least second flow circuit (50) containing the conveyor device (31) and the first heat exchanger (7), and preferably is also a heating flow circuit. In this way more flexibility is created in the flow circuit system (1) for a vehicle.

An air source heat pump system includes at least one heat pump sub-system and at least one water tank. Each heat pump sub-system includes a refrigerant circulation path and a water supply circulation path. The refrigeration circulation path includes a compressor, a first heat exchanger, a first throttling device, and an evaporator that are sequentially connected to one another. The water supply circulation path includes a first supply pipe, a second supply pipe, a return pipe, and a waterway control valve. The first supply pipe and the second supply pipe are each communicated with an end of the first heat exchanger through the waterway control valve, and the return pipe is communicated with another end of the first heat exchanger. The return pipe is communicated with a water inlet of a corresponding water tank, and the second supply pipe is communicated with a water outlet of the corresponding water tank.

A refrigeration system includes a dedicated defrost-mode compressor that delivers high pressure, high temperature refrigerant to one or more evaporators to defrost the evaporators.

A refrigeration system includes an expansion valve downstream of one or more medium temperature compressors. The expansion valve is configured to decrease pressure of a portion of refrigerant output by the one or more medium temperature compressors. When defrost operation of an evaporator is indicated, the refrigerant with decreased pressure from the expansion valve is provided to the evaporator for at least a period of time sufficient to defrost the evaporator.

A method includes receiving, by a processing device and from a variable frequency drive coupled to one or more compressors, operation information of the one or more compressors. The method also includes comparing the operation information of the one or more compressors to an operation threshold and determining that the operation information satisfies the operation threshold. The method also includes changing, based on the determination that the operation information of the one or more compressors satisfies the operation threshold, an operation parameter of a component of the refrigeration system. Changing the operation parameter increases at least one of: (i) a velocity of a working fluid in a piping assembly fluidly coupled to the one or more compressors, or (ii) a flow rate of an oil in the piping assembly flowing into the one or more compressors.

A refrigeration assembly includes a receiver tank, a heat exchanger, a first piping assembly, and a second piping assembly. The receiver tank has a fluid outlet and a fluid inlet that receives a working fluid. The heat exchanger is disposed within the receiver tank. The heat exchanger has coiled tubing that is fluidly coupled to the fluid inlet and to the fluid outlet. The first piping assembly is disposed between and is fluidly coupled to the fluid inlet and the coiled tubing. The first piping assembly has a first double riser and a first P-trap. The second piping assembly is disposed between and is fluidly coupled to the fluid outlet and the coiled tubing. The second piping assembly includes a second double riser and a second P-trap.