Refrigeration cycle apparatus

#The present disclosure relates to a refrigeration cycle apparatus.

#In the related art, R410A has been frequently used as a refrigerant in refrigeration cycle apparatuses such as air conditioners. R410A is a two-component mixed refrigerant of difluoromethane (CH2F2; HFC-32 or R32) and pentafluoroethane (C2HF5; HFC-125 or R125), which is a pseudo-azeotropic composition.

#However, R410A has a global warming potential (GWP) of 2088. From the viewpoint of increasing concern for global warming, R32 having a lower GWP has been more frequently used in recent years.

#FIG. 1 is a schematic view of an apparatus used in a flammability test.

#FIG. 2A is a diagram showing points A to M and O, and line segments that connect these points to each other in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is 100 mass %.

#FIG. 2B is a diagram showing points A to C, B′ and O, and line segments that connect these points to each other in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is 100 mass %.

#In the present specification, the term “refrigerant” includes at least compounds that are specified in ISO 817 (International Organization for Standardization), and that are given a refrigerant number (ASHRAE number) representing the type of refrigerant with “R” at the beginning; and further includes refrigerants that have properties equivalent to those of such refrigerants, even though a refrigerant number is not yet given. Refrigerants are broadly divided into fluorocarbon compounds and non-fluorocarbon compounds in terms of the structure of the compounds. Fluorocarbon compounds include chlorofluorocarbons (CFC), hydrochlorofluorocarbons (HCFC), and hydrofluorocarbons (HFC). Non-fluorocarbon compounds include propane (R290), propylene (R1270), butane (R600), isobutane (R600a), carbon dioxide (R744), ammonia (R717), and the like.

#In the present specification, the phrase “composition comprising a refrigerant” at least includes (1) a refrigerant itself (including a mixture of refrigerants), (2) a composition that further comprises other components and that can be mixed with at least a refrigeration oil to obtain a working fluid for a refrigerating machine, and (3) a working fluid for a refrigerating machine containing a refrigeration oil. In the present specification, of these three embodiments, the composition (2) is referred to as a “refrigerant composition” so as to distinguish it from a refrigerant itself (including a mixture of refrigerants). Further, the working fluid for a refrigerating machine (3) is referred to as a “refrigeration oil-containing working fluid” so as to distinguish it from the “refrigerant composition.”

#In the present specification, when the term “alternative” is used in a context in which the first refrigerant is replaced with the second refrigerant, the first type of “alternative” means that equipment designed for operation using the first refrigerant can be operated using the second refrigerant under optimum conditions, optionally with changes of only a few parts (at least one of the following: refrigeration oil, gasket, packing, expansion valve, dryer, and other parts) and equipment adjustment. In other words, this type of alternative means that the same equipment is operated with an alternative refrigerant. Embodiments of this type of “alternative” include “drop-in alternative,” “nearly drop-in alternative,” and “retrofit,” in the order in which the extent of changes and adjustment necessary for replacing the first refrigerant with the second refrigerant is smaller.