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.

A CO.sub.2 refrigeration system includes a plurality of compressors configured to circulate a CO.sub.2 refrigerant, a suction line configured to deliver the CO.sub.2 refrigerant to the compressors, an oil separator configured to separate oil from the CO.sub.2 refrigerant, and an oil return line configured to deliver the oil from the oil separator to the suction line. The oil mixes with the CO.sub.2 refrigerant in the suction line before reaching the compressors.

A refrigerant consisting or consisting essentially of: a) a nonflammable high volatility component consisting of carbon dioxide, and b) a nonflammable low volatility component selected from the group consisting of: HFO1224yd(Z), HFO1224yd(E), HFO1233zd(E), HFO1233zd(Z), HFO1233xf, HFO1336mzz(E), HFO1336mzz(Z), 2-bromo-3,3,3-trifluoroprop-1-ene and mixtures thereof; c) an intermediate volatility component selected from the group consisting of: HFO1234yf, HFO1234ze(E), HFO1225ye(Z), HFO1243zf and mixtures thereof; and d) optionally a component selected from the group consisting of HFC227ea, HFC152a, HFC32 and mixtures thereof.

The present invention relates to compositions for use in refrigeration, air-conditioning, and heat pump systems wherein the composition comprises a fluoroolefin and at least one other component. The compositions of the present invention are useful in processes for producing cooling or heat, as heat transfer fluids, foam blowing agents, aerosol propellants, and fire suppression and fire extinguishing agents.

In accordance with the present invention refrigerant compositions are disclosed. The compositions comprise a refrigerant mixture consisting essentially of HFC-32, HFO-1234yf, and CO.sub.2. The compositions are useful in processes to produce cooling and heating, in methods for replacing refrigerant R-32, and in refrigeration, air conditioning or heat pump systems. These inventive compositions are match cooling performance for R-32 with GWP less than 400 or less than 300.

Non-ozone depleting and non-flammable refrigerant compositions with GWPs less than 1050 which may replace HFC404A, HFC507 and HFC410A in refrigeration and air-conditioning systems.

A composition comprising: (i) 1,1-difluoroethene (vinylidene fluoride, R-1132a); (ii) carbon dioxide (CO.sub.2, R-744); (iii) pentafluoroethane (R-125); and (iv) one or more of trifluoromethane (R-23) and hexafluoroethane (R-116).

A refrigerant for a cooling device comprising a cooling circuit with at least one heat exchanger, the refrigerant undergoing a phase transition in the heat exchanger, the refrigerant being a refrigerant mixture composed of a mass fraction of carbon dioxide (CO.sub.2), a mass fraction of pentafluoroethane (C.sub.2HF.sub.5) and a mass fraction of at least one other component, wherein the mass fraction of carbon dioxide in the refrigerant mixture is up to 60 mass percent, the mass fraction of pentafluoroethane being 11 to 72 mass percent, the other component being 2,3,3,3-tetrafluoropropene (C.sub.3H.sub.2F.sub.4), the mass fraction of 2,3,3,3-tetrafluoropropene being up to 51 mass percent.

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)-RFC-1132], cis-1,2-difluoroethylene [(Z)-HFO-1132], fluoroethylene (HFO-1141), and 3,3,3-trifluoropropyne (TFP).

A refrigeration cycle apparatus according to the present disclosure includes a refrigeration circuit which includes a compressor, an outdoor heat exchanger, an indoor heat exchanger, and an expansion valve, and refrigerant is enclosed in the refrigeration circuit. The refrigerant contains three components R32, HFO1123, and R744 and, in a composition diagram in which a mass ratio between the three components is represented by triangular coordinates, the mass ratio between the three components falls in a range enclosed by a first straight line connecting a point A to a point B, a second straight line connecting the point A to a point C, a third straight line connecting the point C to a point D, and a first curve connecting the point B to the point D. All the three components each have a mass ratio of more than 0% by mass.