A refrigeration cycle apparatus that can improve operation efficiency when a refrigerant that contains at least 1,2-difluoroethylene is used is provided. An air conditioning apparatus 1 includes a compressor (21), an outdoor heat exchanger (23), an outdoor expansion valve (24), an indoor heat exchanger (31), and a suction injection pipe (40), and uses a refrigerant that contains at least 1,2-difluoroethylene. The suction injection pipe (40) allows a part of a refrigerant that flows toward the indoor heat exchanger (31) from the outdoor heat exchanger (23) to merge with a low-pressure refrigerant that is sucked into the compressor (21).

A two-stage refrigeration apparatus (500) includes a first cycle (510) and a second cycle (520). The first cycle (510) includes a first compressor (511), a first condenser (512), a first expansion mechanism (513), and a first evaporator (514) that are arranged in such a manner as to be connected to the first cycle. A first refrigerant circulates through the first cycle. The second cycle (520) includes a second downstream-side condenser (523) and a second evaporator (527) that are arranged in such a manner as to be connected to the second cycle. A second refrigerant circulates through the second cycle. The first evaporator (514) and the second downstream-side condenser (523) constitute a cascade condenser (531). In the cascade condenser (531), heat is exchanged between the first refrigerant and the second refrigerant. At least one of the first refrigerant and the second refrigerant is a refrigerant mixture containing at least 1,2-difluoroethylene (HFO-1132(E)).

A refrigeration cycle is a refrigeration cycle using a mixed refrigerant which is a flammable refrigerant and which contains at least 1,2-difluoroethylene (HFO-1132(E)), and includes a compressor (1), a heat-source-side heat exchanger (3), an expansion mechanism (4), a use-side heat exchanger (2), and a decompression mechanism (7). The decompression mechanism (7) decompresses, between an inlet and an outlet of the heat-source-side heat exchanger (3), the mixed refrigerant flowing through the heat-source-side heat exchanger (3) that functions as an evaporator.

The present invention provides a refrigerant composition that has a low GWP and ASHRAE non-flammability performance. Specifically, the present invention provides a composition comprising a mixture of fluorinated hydrocarbons, the mixture comprising difluoromethane (R32), pentafluoroethane (R125), 1,1,1,2-tetrafluoroethane (R134a), and 2,3,3,3-tetrafluoropropene (1234yf) at specific concentrations.

The present invention provides a refrigerant composition that has a low GWP and ASHRAE non-flammability performance. Specifically, the present invention provides a composition comprising a mixture of fluorinated hydrocarbons, the mixture comprising difluoromethane (R32), pentafluoroethane (R125), 1,1,1,2-tetrafluoroethane (R134a), and 2,3,3,3-tetrafluoropropene (1234yf) at specific concentrations.

A warm-water generating apparatus (1) uses, as a refrigerant, a mixed refrigerant containing at least 1,2-difluoroethylene (HFO-1132(E)). The warm-water generating apparatus (1) includes a compressor (21), a heat-source-side air heat exchanger (24), an expansion valve (23), and a use-side water heat exchanger (22). The water heat exchanger (22) causes the mixed refrigerant flowing therein and first water to exchange heat with each other to heat the first water.

A refrigeration cycle apparatus that is able to reduce the amount of refrigerant used while reducing a pressure loss in the case where a refrigerant containing at least 1,2-difluoroethylene is used is provided. In an air conditioner (1) including a refrigerant circuit (10), including a compressor (21), an outdoor heat exchanger (23), an outdoor expansion valve (24), and an indoor heat exchanger (31), and a refrigerant containing at least 1,2-difluoroethylene and sealed in the refrigerant circuit (10), the outdoor heat exchanger (23) has a heat transfer tube (23b) of which a pipe diameter is greater than or equal to 6.35 mm and less than 10.0 mm.

A refrigeration cycle apparatus capable of keeping a LCCP low when a heat cycle is performed using a sufficiently small-GWP refrigerant, and a method of determining a refrigerant enclosure amount in the refrigeration cycle apparatus are provided. An outdoor unit (20) including a compressor (21) and an outdoor heat exchanger (23), an indoor unit (30) including an indoor heat exchanger (31), and a refrigerant pipe (5, 6) that connects the outdoor unit (20) and the indoor unit (30) to each other are provided. A refrigerant containing at least 1,2-difluoroethylene is enclosed in a refrigerant circuit (10) that is constituted by connecting the compressor (21), the outdoor heat exchanger (23), and the indoor heat exchanger (31) to one another. An enclosure amount of the refrigerant in the refrigerant circuit (10) per 1 kW of refrigeration capacity satisfies a condition of 160 g or more and 560 g or less.

The present invention relates to compositions for use in refrigeration, air-conditioning, and heat pump systems wherein the composition comprises a tetrafluoropropene 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.

The present invention relates to a refrigerant composition, including trifluoroiodomethane (CF.sub.3I); 1,3,3,3-tetrafluoropropene (HFO-1234ze); difluoromethane (HFC-32), and pentafluoroethane (HFC-125) for use in a heat exchange system, including refrigeration applications and in particular aspects to the use of such compositions as a replacement of the refrigerant R-22 or R-404A for heating and cooling applications and to retrofitting heat exchange systems, including systems designed for use with R-22 or R-404A.