The integrated expander and motor-compressor assembly comprises a compression section mounted between the two radial bearings on a trans-mission shaft, an expander cantilevered at a free end of the transmission shaft, a gas diffuser and a duct between the expander and a first radial bearing, the first radial bearing been the closest radial bearing to the expander. The gas diffuser diffuses a gas barrier which is sucked up by the duct.

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.

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 refrigeration system includes a compressor, a condenser, a throttling device, and an evaporator, which are connected in sequence to form a cooling circuit, the refrigeration system further includes an oil recovery system which includes: an operation chamber, which includes a first port communicating with an oil-containing position in the refrigeration system through a first pipeline, and a second port communicating with a bearing chamber or a bearing lubrication pipeline of the compressor through a second pipeline; and a main piston in the operation chamber, the main piston reciprocating in the operation chamber to perform an extraction stroke and a discharge stroke; in the extraction stroke, an oil-containing refrigerant in the oil-containing position in the refrigeration system is extracted to the operation chamber; and in the discharge stroke, the oil-containing refrigerant in the operation chamber is delivered to the bearing chamber or the bearing lubrication pipeline of the compressor.

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.

Extra heat in a closed cycle power generation system, such as a reversible closed Brayton cycle system, may be dissipated between discharge and charge cycles. An extra cooling heat exchanger may be added on the discharge cycle and disposed between a cold side heat exchanger and a compressor inlet. Additionally or alternatively, a cold thermal storage medium passing through the cold side heat exchanger may be allowed to heat up to a higher temperature during the discharge cycle than is needed on input to the charge cycle and the excess heat then dissipated to the atmosphere.

The disclosure relates to a heating and/or cooling system having an energy conversion device included in a refrigerant circuit and having reducing means for reducing and/or removing solidified phase change material from a component of a heat transfer circuit, wherein the reducing means are driven by energy provided from the energy conversion device. The disclosure also relates to a corresponding method for reducing or removing solidified phase change material.

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.

An air turbo-refrigeration unit includes a compressor on die same shaft as a turbo-expander, an electric motor, a two-cavity heat exchanger, a recuperator, a water trap, and a refrigeration chamber with a cooler and a fan. The unit has a two-cavity heat exchanger/cooler and second and third water traps. The compressor is connected by its outlet to the first cavity of the heat exchanger, which connects to the first cavity of the heat exchanger/cooler. The first cavity of the heat exchanger/cooler is connected via the second water trap to the first cavity of the recuperator, which communicates with the inlet of the turbo-expander via the first water trap. The turbo-expander is connected by its outlet via the third water trap to the second cavity of the heat exchanger/cooler, which communicates with the cooler and, via the cooler, with the second cavity of the recuperator, which communicates with the compressor inlet.

Extra heat in a closed cycle power generation system, such as a reversible closed Brayton cycle system, may be dissipated between discharge and charge cycles. An extra cooling heat exchanger may be added on the discharge cycle and disposed between a cold side heat exchanger and a compressor inlet. Additionally or alternatively, a cold thermal storage medium passing through the cold side heat exchanger may be allowed to heat up to a higher temperature during the discharge cycle than is needed on input to the charge cycle and the excess heat then dissipated to the atmosphere.