The refrigeration cycle apparatus includes: liquid-side connection piping that extends from liquid-side refrigerant piping; gas-side connection piping that extends from gas-side refrigerant piping; a refrigerant storage tank that stores refrigerant, an intake side thereof being connected to the liquid-side connection piping, and a discharge side thereof being connected to the gas-side connection piping; an inlet-side electromagnetic valve that is disposed on the liquid-side connection piping, and that is opened when there is no passage of electric current; an inlet-side check valve that is disposed on the liquid-side connection piping, and that allows the refrigerant to flow only toward the refrigerant storage tank; and a valve apparatus that is disposed on the gas-side connection piping, that is opened during passage of electric current to the inlet-side electromagnetic valve, and that is delayed before being shut off after passage of electric current to the inlet-side electromagnetic valve is stopped.

A control method of a transcritical carbon dioxide composite heat pump system is disclosed, wherein the transcritical carbon dioxide composite heat pump system includes: a CO.sub.2 main circuit compressor, an air-cooling-air-cooling recombiner, a supercooling-evaporation recombiner, an evaporator and a CO.sub.2 auxiliary compressor; wherein the air-cooling-air-cooling recombiner comprises a CO.sub.2 main circuit, a CO.sub.2 auxiliary circuit and a water circuit; the supercooling-evaporation recombiner comprises a CO.sub.2 main circuit supercooling section and a CO.sub.2 auxiliary circuit evaporation section. The present invention includes two working modes according to the return water temperature, so that the unit has a wider application range and meets daily needs. There is only one heat exchanger for refrigerant and water. Compared with the three water and refrigerant heat exchangers in the conventional transcritical CO.sub.2 composite heat pump, the circulating water circuit is a single circuit with one inlet and one outlet.

A transcritical R-744 refrigeration system, especially used for refrigerating a skating rink, has a heat exchanger between the gas cooler followed by a throttling device and the flash tank (or receiver), in order to eliminate the need of a flash-gas bypass. The heat exchanger connects to an external mechanical refrigeration system operating at a higher evaporating temperature than the transcritical R-744 refrigeration system, and generally totally condenses the vapor of the R-744 refrigerant before it reaches the flask tank. A method for improving the energy efficiency of the transcritical R-744 refrigeration system is also disclosed.

An energy recovery apparatus for use in a refrigeration system, comprises an intake port, a nozzle, a turbine and a discharge port. The intake port is adapted to be in fluid communication with a refrigerant cooler of a refrigeration system. The nozzle comprises a fluid passageway. The nozzle is configured to increase velocity of the refrigerant as it passes through the fluid passage -way. The turbine is positioned relative to the nozzle and configured to be driven by refrigerant discharged from the fluid passageway. The discharge port is downstream of the turbine and is configured to be in fluid communication with an evaporator of the refrigeration system.

The present invention provides a vending machine having a compartment whose preset internal temperature is lower than those of compartments in conventional commonly-used beverage vending machines, and yet being capable of limiting energy required for cooling the interiors of its compartments. A vending machine 1 for cooling and dispensing products has at least three compartments (right compartment 4, center compartment 5, and left compartment 6) which are defined by heat-insulated walls (partition walls) 3 and which are for cooling products contained therein. The right, center and left compartments 4, 5, 6 are disposed side by side in a row. The preset internal temperature for the center compartment 5, which lies between the right and left compartments 4, 6, is lower than those for the right and left compartments 4, 6.

A heat exchange device has a heat transfer member having thermal conductivity and a fin that is provided integrally with the heat transfer member. A heat transfer is performed between the heat transfer member and the fin. The fin is configured by more than one of a carbon nanotube aggregate that is configured by carbon nanotubes assembled together. The carbon nanotube aggregates are arranged on the heat transfer member and distanced from each other, and protrude from the heat transfer member in an axial direction of the carbon nanotubes.

Methods and systems for providing control of a heat pump of a motor vehicle are presented. In one operating mode, speed of a heat pump compressor is controlled responsive to an outlet pressure of the heat pump compressor. In a second operating mode, speed of the heat pump compressor is controlled responsive to a pressure ratio between an inlet and an outlet of the heat pump compressor.

A method for controlling a vapour compression system (1) including a compressor unit (2) including at least two compressors (3, 12), a heat rejecting heat exchanger (4), a receiver (6), an expansion device (7) and an evaporator (8) arranged in a refrigerant path is disclosed. At least one of the compressors is a main compressor (3) being fluidly connected to an outlet of the evaporator (8) and at least one of the compressors is a receiver compressor (12) being fluidly connected to a gaseous outlet (10) of the receiver (6). A flow of vapour entering the receiver (6), such as a mass flow of vapour entering the receiver (6) is estimated and compared to a first threshold value. In the case that the estimated flow is above the first threshold value, a pressure prevailing inside the receiver (6) is controlled by operating the receiver compressor (12).

A refrigeration system includes a gas cooler or a condenser configured to reject first heat from a first fluid that is at a first pressure and that is in a supercritical state or subcritical state. The refrigeration system further includes an evaporator configured to absorb second heat into a second fluid that is at a second pressure that is lower than the first pressure and that is in a liquid state, a vapor state, or a two-phase mixture of liquid and vapor. The refrigeration system further includes a rotary pressure exchanger configured to receive the first fluid from the gas cooler or the condenser, to receive the second fluid from the evaporator, and to exchange pressure, via a rotor of the rotary pressure exchanger, between the first fluid and the second fluid.

Heat pump type heating apparatus capable of performing a continuous dual-stage operation without stopping a high stage side compressor even when a return temperature of a heating medium reaches a prescribed high temperature and, thereby, improving a sense of being insufficiently warmed due to stoppage of the high stage side compressor or a sense of being insufficiently warmed due to execution of frequent defrosting operations. The heat pump type heating apparatus includes an internal heat exchanger (a second internal heat exchanger) that performs heat exchange between a low-temperature refrigerant on a low-pressure side of a low stage side refrigeration circuit and a high-temperature refrigerant on a high-pressure side of a high stage side refrigerant circuit, a bypass pipe bypassing the internal heat exchanger, and flow path control means that controls a refrigerant flow to each of the internal heat exchanger and the bypass pipe.