A cooling system includes a compressor configured to pressurize carbon dioxide to form pressurized carbon dioxide, a mixer configured to generate mixed refrigerant in which the pressurized carbon dioxide and solvent in a liquid state, a depressurization apparatus provided downstream from the mixer and configured to depressurize the mixed refrigerant, a separator configured to separate carbon dioxide in a gas state from the mixed refrigerant, a heat exchanger configured to exchange heat between the mixed refrigerant cooled through depressurization and a fluid to be cooled, and a second heat exchanger configured to cool the carbon dioxide or the mixed refrigerant using vaporized carbon dioxide or the mixed refrigerant.

Air is taken out from a drying oven 1 for drying a coating film of a work piece 2, and the air is cooled such that each of at least part of moisture and at least part of a VOC which are contained in the air is condensed to be removed from the air. The air after the cooling is heated, and is returned into the drying oven 1. A heat pump 3 whose heat absorption source is the air taken out from the drying oven 1 and whose heat radiation source is the air after the cooling is provided. By using the heat pump 3, cooling and heating of the air are performed.

The present invention provides a composition comprising a refrigerant (mixed refrigerant) having three types of performance, i.e., a coefficient of performance (COP) and refrigerating capacity (Cap) that are equivalent to or higher than those of R410A, and a sufficiently low GWP. Specifically, the present invention provides a composition comprising a refrigerant, the refrigerant comprising CF.sub.3I, CO.sub.2 (R744), and at least one compound A selected from the group consisting of trifluoroethylene (HFO-1123), trans-1,2-difluoroethylene [(E)-HFO-1132], cis-1,2-difluoroethylene [(Z)—HFO-1132], fluoroethylene (HFO-1141), and 3,3,3-trifluoropropyne (TFP).

A refrigeration system is described that includes a compression device configured to increase a pressure of a refrigerant. The refrigeration system further includes a first heat exchanger configured to reject heat from the refrigerant and reduce a temperature of the refrigerant. The refrigeration system further includes a storage device configured to store the refrigerant at a supercritical state. The refrigeration system further includes an expansion device configured to reduce the pressure of the refrigerant. The refrigeration system further includes a second heat exchanger configured to absorb heat into the refrigerant and increase the temperature of the refrigerant. The refrigeration system further includes a controller configured to release the refrigerant from the storage device to the expansion device to provide cooling capacity to the refrigeration system.

A climate-control system can be used to heat or cool a space. The climate-control system may include first and second vessels between which refrigerant and co-fluid may be circulated. The refrigerant may be absorbed into the co-fluid within the first vessel at a first rate. The refrigerant may desorb from the co-fluid within the second vessel at a second rate. Ultrasonic energy may be used to adjust the second rate to substantially match the first rate.

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 direct contact densified fluid-based thermodynamic treatment system uses the fluid to effect heat transfer as the working fluid in a separate yet linked treatment system. During certain phases of operation of a densified fluid-based treatment process wherein it is necessary to distill the fluid to maintain the purity of the densified fluid heat is imparted to the densified fluid raising it above the boiling point for the associated pressure within a vessel. A densified fluid-based refrigeration/thermodynamic system removes heat during the condensing cycle of a working densified fluid treatment system and use the removed heat for distillation of the same working fluid in the distillation vessel. The process does not require an external heating or cooling system, and thus can be entirely supported by a single machine using the same densified fluid during its operational phase.

A system includes a first heat exchanger, a flash tank, a first compressor, a condenser, a second heat exchanger, and a second compressor. The first heat exchanger removes heat from carbon dioxide refrigerant. The flash tank stores the carbon dioxide refrigerant from the first heat exchanger. The first compressor compresses the carbon dioxide refrigerant and sends the compressed carbon dioxide refrigerant to the first heat exchanger. The condenser removes heat from a second refrigerant. The second heat exchanger receives the second refrigerant from the condenser. The second heat exchanger further removes heat from the carbon dioxide refrigerant stored in the flash tank. The second compressor compresses the second refrigerant from the heat exchanger. The second compressor sends the second refrigerant to the condenser.

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 refrigerant loop of a vapor injection heat pump includes a compressor, first and second expansion valves, and first and second separator valves. The separator valves allow an entire refrigerant flow to pass therethrough or operate to separate vapor and liquid components of expanded refrigerant and inject the vapor component into a suction port of the compressor. Vapor injection occurs in both heating and cooling modes of operation and may depend upon an ambient condition (e.g., high or low ambient temperatures). An accumulator receives an output refrigerant of the heat exchangers dependent upon the mode and directs a vapor component into another suction port of the compressor. A control module controls at least the first and second expansion valves and first and second separator valves dependent upon the mode of operation which include, among others, heating, cooling, and dehumidification and re-heating.