A system includes a pressure exchanger (PX). The PX is coupled to a motor that controls an operating speed of the PX. The system further includes a first pressure gauge configured to generate first pressure data indicative of a pressure of a fluid of a condenser. A first controller is to generate a first control signal based on the first pressure data. The motor of the PX is configured to adjust the operating speed of the PX based on the first control signal. The system further includes a pump. The system further includes a fluid density sensor for generating fluid density data associated with a first output fluid of the PX. A second controller is to generate a second control signal based on at least the fluid density data. The pump is to adjust an operating speed of the pump based on the second control signal.

A refrigerant cycle device includes a compressor, a radiator, a first expansion valve, a second expansion valve, a first evaporator, a second evaporator, and a controller. The controller is configured to switch between a first evaporator priority control and a second evaporator priority control. During the first evaporator priority control, the controller controls a throttle opening of the second expansion valve based on at least one of a temperature of a first evaporator, a temperature of a refrigerant flowing through the first evaporator, and a temperature of an air having exchanged heat in the first evaporator. During the second evaporator priority mode, the controller controls the throttle opening based on a refrigerant state of the second evaporator. When the at least one of the temperatures is equal to or greater than a switching temperature, the second priority mode is switched to the first priority mode.

A climate-control system may include a first compressor, a second compressor, a suction manifold, and a flow restrictor. The first and second compressors each include a shell and a compression mechanism. The shells define suction chambers from which the compression mechanisms draw working fluid. The shells include suction inlet fittings through which working fluid is drawn into the suction chambers. The suction inlet fittings are fluidly connected to the suction manifold. The suction manifold provides suction-pressure working fluid to the suction inlet fittings of the first and second compressors. The flow restrictor may be at least partially disposed within the suction manifold.

A trans-critical thermodynamic system includes an expansion device and a separator. The expansion device receives a supercritical fluid containing solutes. The expansion device is operable to expand the supercritical fluid to produce a sub-critical gas by reducing a temperature and/or a pressure of the supercritical fluid. The separator removes the solutes from the sub-critical gas.

Systems and methods for implementing ejector refrigeration cycles with cascaded evaporation stages that utilize a pump to optimize operation of the ejector and eliminate the need for a compressor between the evaporation stages.

A dual reclaim coil with a smart control application is provided that allows the refrigerant inlet to the HVAC unit switch between the two sides of the condenser is aimed to use the high temperature and pressure of the condenser/gas cooler outlet while a CO.sub.2 refrigerant system is operating above critical point. This occurs in hot ambient conditions, when the need for heating in the space is not as great as in the wintertime and the available heat at the condenser/gas cooler's outlet is sufficient to satisfy the heating load. This also mitigates space overcooling, while increasing the CO.sub.2 transcritical system's efficiency by subcooling the refrigerant for applications involving dehumidification HVAC systems which often results in a phenomenon called “overcooling” during the dehumidification season.

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.

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.

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.