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.

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.

An object is to provide a mixed refrigerant having four types of performance, i.e., a coefficient of performance and a refrigerating capacity that are equivalent to those of R410A, a sufficiently low GWP, and a lower flammability (Class 2L) according to the ASHRAE standard. Provided as a means for a solution is a composition comprising a refrigerant, the refrigerant comprising trans-1,2-difluoroethylene (HFO-1132(E)) and trifluoroethylene (HFO-1123) in a total amount of 99.5 mass % or more based on the entire refrigerant, and the refrigerant comprising 62.0 mass % to 72.0 mass % of HFO-1132(E) based on the entire refrigerant.

A refrigerating system may include a compressor configured to compress a non-azeotropic mixed refrigerant, a condenser configured to condense the compressed non-azeotropic mixed refrigerant, a three-way valve configured to branch the non-azeotropic mixed refrigerant condensed by the condenser, a first evaporator configured to supply cold air to a first interior space, a second evaporator configured to supply cold air to a second interior space at a temperature higher than at a temperature of the first interior space, and a capillary tube configured to expand the non-azeotropic mixed refrigerant branched by the three-way valve and supply the expanded non-azeotropic mixed refrigerant to at least one of the first evaporator or the second evaporator. With such features, a high-efficiency refrigerating system to which the non-azeotropic mixed refrigerant is applied may be implemented.

An air-conditioning apparatus includes: a heat source-side system having an intermediate heat exchanger that causes heat exchange to be performed between a heat source-side heat medium and a use-side heat medium, causes the heat source-side heat medium to receive or transfer heat, and causes the use-side heat medium to undergo a phase change; and a use-side cycle circuit formed of pipes connecting, to one another, the intermediate heat exchanger, a pump that sucks and delivers the use-side heat medium in a liquid state, a use-side heat exchanger that heats or cools air in an air-conditioning target space due to heat exchange causing a change in phase of the use-side heat medium, and a pressure-reducing device that reduces a pressure of the use-side heat medium that passes through the use-side heat exchanger, the use-side cycle circuit causing the use-side heat medium to circulate through the use-side cycle circuit.

A method of achieving high heat transfer during cooling includes providing an aluminum body having an inner surface enclosing a channel, where the inner surface comprises microscale roughness features and microcavities configured to enhance nucleation site density during flow boiling. A refrigerant is transported through the channel. During the transport, the refrigerant absorbs heat from a thermal load and undergoes flow boiling. The heat is transferred to the refrigerant at an average heat transfer coefficient of at least about 10 kW/(m.sup.2.Math.K) at a mass flux of about 300 kg/(m.sup.2.Math.s).

An ejector-based cryogenic refrigeration system for cold energy recovery includes a first cryogenic refrigeration loop connected by a helium compressor and a cryogenic refrigerator and a second cryogenic refrigeration loop connected by the helium compressor, a regenerator, an ejector, a cold head of the cryogenic refrigerator, an end to be cooled and a pressure regulating valve. The cryogenic refrigerator is separated from the end to be cooled. The cryogenic refrigerator and the cryogenic helium cooling loop share a helium compressor, which improves the utilization efficiency of the device and reduces the cost. The ejector allows a part of fluids to circulate in the cryogenic loop, so as to maintain a required cryogenic condition, recover the pressure of the fluids, reduce the gas flowing though the compressor loop, and thus reduce the power consumption of the compressor.

An air conditioning unit capable of performing a refrigeration cycle using a small-GWP refrigerant is provided. A refrigeration cycle apparatus (1, 1a to 1m) includes a refrigerant circuit (10) including a compressor (21), a condenser (23, 31, 36), a decompressing section (24, 44, 45, 33, 38), and an evaporator (31, 36, 23), and a refrigerant containing at least 1,2-difluoroethylene enclosed in the refrigerant circuit (10).

A temperature control apparatus for supplying fluid to control a temperature of at least one semiconductor wafer within a semiconductor processing chamber, the temperature control apparatus comprising: a mixed refrigerant refrigeration system; the temperature control apparatus being configured to supply the mixed refrigerant to at least one conditioning circuit within the semiconductor processing chamber and to receive the mixed refrigerant from the at least one conditioning circuit. The temperature control apparatus comprises a temperature control circuitry for controlling a temperature of the at least one conditioning circuit to one of a plurality of predetermined temperatures, at least one of the temperatures being below -100° C., the temperature control circuitry being configured to control the temperature of the at least one conditioning circuit by controlling at least one of a mass flow rate, composition or temperature of the mixed refrigerant supplied to the at least one conditioning circuit.

A temperature control apparatus for supplying fluid to control a temperature of at least one semiconductor wafer within a semiconductor processing chamber, the temperature control apparatus comprising: a mixed refrigerant refrigeration system; the temperature control apparatus being configured to supply the mixed refrigerant to at least one conditioning circuit within the semiconductor processing chamber and to receive the mixed refrigerant from the at least one conditioning circuit. The temperature control apparatus comprises a temperature control circuitry for controlling a temperature of the at least one conditioning circuit to one of a plurality of predetermined temperatures, at least one of the temperatures being below -100° C., the temperature control circuitry being configured to control the temperature of the at least one conditioning circuit by controlling at least one of a mass flow rate, composition or temperature of the mixed refrigerant supplied to the at least one conditioning circuit.