Composition containing refrigerant, use thereof, refrigerator having same, and method for operating refrigerator

Abstract

The technical problem to be solved by the invention is to provide a novel low-GWP mixed refrigerant. [Solution] A refrigerant-containing composition which contains trans-1, 2-difluoroethylene (HFO-1132 (E)) and difluoromethane (R32) in an amount of 99.5% by mass or more in total relative to the total amount of the refrigerant, and which contains HFO-1132 (E) in an amount of 63.0-68.3% by mass relative to the total amount of HFO-1132 (E) and R32; the content of HFO-1132 (E) is 70.5-76.5 mass% relative to the total of HFO-1132 (E) and R32, and the content of HFO-1132 (E) is 70.5-76.5 mass%; alternatively, the content of HFO-1132 (E) is 81.6 to 83.7 mass% relative to the total of HFO-1132 (E) and R32.

Description

Technical Field

[0001] The present invention relates to a composition containing a refrigerant, use thereof, a refrigerator having the composition, and a method for operating the refrigerator. Background Art

[0002] As a heat cycle working fluid that can replace R410A, a heat cycle working fluid containing trifluoroethylene (HFO-1123) and 1,2-difluoroethylene (HFO-1132) has been proposed (Patent Document 1).

[0003] Prior art literature Patent Literature Patent Document 1: International Publication No. 2015 / 141678 Summary of the Invention

[0004] Problems to be solved by the invention The object of the present invention is to provide a new low GWP mixed refrigerant.

[0005] Technical solutions to problems Item 1. A composition containing a refrigerant, wherein The refrigerant contains 99.5% by mass or more of trans-1,2-difluoroethylene (HFO-1132(E)) and difluoromethane (R32) in total relative to the total refrigerant. Contains 63.0% to 68.3% by mass of HFO-1132(E) relative to the total of HFO-1132(E) and R32; Contains 70.5% to 76.5% by mass of HFO-1132(E) based on the total of HFO-1132(E) and R32; or The amount of HFO-1132(E) contained is 81.6% by mass to 83.7% by mass based on the total of HFO-1132(E) and R32.

[0006] Item 2. The composition according to Item 1, wherein the refrigerant further contains 0.5% by mass or less of at least one selected from methylamine, acetylene, HFO-1141, HFO-1123, HFC-143a, HFC-134a, HFO-1132a, Z-HFO-1132, HFO-1243zf, HFC-245cb, HCFC-1122, HCFC-124, CFC-1113, and 3,3,3-trifluoropropyne in a total amount based on the total refrigerant.

[0007] Item 3. The composition according to Item 1 or 2, further comprising 0.1% by mass or less of water based on the total composition.

[0008] Item 4. The composition according to any one of Items 1 to 3, wherein R12, R22, R134a, R404A, R407A, R407C, R407F, R407H, R410A, R413A, R417A, R422A, R422B, R422C, R422D, R423A, R424A, R426A, R427A, R430A, Use as an alternative refrigerant to R434A, R437A, R438A, R448A, R449A, R449B, R449C, R452A, R452B, R454A, R454B, R454C, R455A, R465A, R474A, R479A, R502, R507, R513A, R1234yf or R1234ze.

[0009] Item 5. A freezing method comprising the step of operating a freezing cycle using the composition according to any one of Items 1 to 3.

[0010] Item 6. A refrigerator comprising the composition according to any one of Items 1 to 3 as a working fluid.

[0011] Item 7. Use of the composition according to any one of Items 1 to 3 as a working fluid in a refrigerator.

[0012] Effects of the Invention The refrigerant of the present invention has a low GWP. DETAILED DESCRIPTION

[0013] In order to solve the above-mentioned technical problems, the inventors of the present invention have conducted intensive studies and found that various mixed refrigerants described below have the above-mentioned characteristics.

[0014] The present invention has been completed through further research based on the above findings. The present invention includes the following embodiments.

[0015] Definition of terms In this manual, the term "refrigerant" includes at least compounds designated by an ASHRAE number (preceding "R"), as defined by ISO 817 (International Organization for Standardization), and also includes substances without an ASHRAE number but exhibiting equivalent refrigerant properties. Based on their structure, refrigerants are broadly categorized as "fluorocarbon compounds" and "non-fluorocarbon compounds." "Fluorocarbon compounds" include chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and hydrofluorocarbons (HFCs).

[0016] In this specification, the term "refrigerant-containing composition" includes at least: (1) the refrigerant itself (including a mixture of refrigerants); (2) a composition that also contains other components and can be used to obtain a working fluid for a refrigerator by mixing with at least refrigeration oil; and (3) a working fluid for a refrigerator containing refrigeration oil. In this specification, of these three types, the composition in (2) is distinguished from the refrigerant itself (including a mixture of refrigerants) and expressed as a "refrigerant composition." Furthermore, the working fluid for a refrigerator in (3) is distinguished from the "refrigerant composition" and expressed as a "working fluid containing refrigeration oil."

[0017] In this specification, the term "replacement," when used in the context of "replacing" a first refrigerant with a second refrigerant, refers to a first type of operation in equipment designed to operate with the first refrigerant. By making only a few component changes and adjustments (at least one of the following: refrigeration oil, gaskets, packings, expansion valves, dryers, or other components) as needed, the equipment can be operated under optimal conditions using the second refrigerant. In other words, this type of operation allows the same equipment to operate by "replacing" the refrigerant. This type of "replacement" can be classified into "drop-in replacement," "nearly drop-in replacement," and "retrofit," depending on the degree of change or adjustment required when switching to the second refrigerant.

[0018] The second type, using a second refrigerant to adapt equipment designed to operate with it for the same purpose as the first refrigerant, also falls under the term "substitution." This type means the "substitution" refrigerant serves the same purpose.

[0019] In this specification, the term "refrigerator" refers to any device that removes heat from an object or space, bringing it to a lower temperature than the surrounding air, and maintaining that lower temperature. In other words, a refrigerator is a device that converts energy from an external source to produce work, moving heat from a lower temperature to a higher temperature.

[0020] In this manual, "Toxicity Class A" refrigerants mean that the permitted concentration (Occupational Exposure Limits (OEL)) for the mixed refrigerant is 400 ppm or higher, as per the US ANSI / ASHRAE 34-2019 standard. "Toxicity Class B" refrigerants mean that the permitted concentration for the mixed refrigerant is less than 400 ppm, as per the US ANSI / ASHRAE 34-2019 standard.

[0021] In the present invention, the permissible concentration (Occupational Exposure Limits (OEL)) of a mixed refrigerant is not particularly limited and refers to a value evaluated based on the central composition. The OEL of each refrigerant is calculated as follows.

[0022] HFO-1132 (E): 350ppm R32: 1000ppm HFO-1132a: 500ppm R124: 1000ppm The OEL of the core composition of the mixed refrigerant is calculated using the following formula.

[0023]

[0024] Where a n Indicates the OEL of each refrigerant compound, mf n Indicates the mole fraction of each refrigerant compound.

[0025] The pressure described in this specification is absolute pressure unless otherwise specified.

[0026] 1. Refrigerant The refrigerant of the present invention contains 99.5% by mass or more of trans-1,2-difluoroethylene (HFO-1132(E)) and difluoromethane (R32) in total based on the entire refrigerant.

[0027] The refrigerant of the present invention may be any of the following (a) to (c).

[0028] (a) containing 63.0% by mass to 68.3% by mass of HFO-1132(E) based on the total of HFO-1132(E) and R32; (b) containing 70.5% by mass to 76.5% by mass of HFO-1132(E) based on the total of HFO-1132(E) and R32; or (c) Contains 81.6% by mass to 83.7% by mass of HFO-1132(E) based on the total of HFO-1132(E) and R32.

[0029] The refrigerant of the present invention is a low GWP mixed refrigerant.

[0030] The refrigerant of the present invention, when containing 63.0 to 68.3 mass % of HFO-1132(E) relative to the total of HFO-1132(E) and R32, has a GWP of 250 or less, an ASHRAE toxicity classification of A, and a refrigeration capacity ratio of 108% or more to R410A.

[0031] When the refrigerant of the present invention contains 70.5% to 76.5% by mass of HFO-1132(E) relative to the total of HFO-1132(E) and R32, it has a GWP of 200 or less, an ASHRAE toxicity classification of A, and a condensation slip of 0.12K or less, similar to R410A.

[0032] When the refrigerant of the present invention contains 81.6% to 83.7% by mass of HFO-1132(E) relative to the total of HFO-1132(E) and R32, the GWP is 125 or less and the ASHRAE toxicity classification is A.

[0033] The refrigerant of the present invention may contain additional refrigerants in addition to HFO-1132(E) and R32, within the limits of not impairing the aforementioned properties and effects. In this regard, in one embodiment, the refrigerant of the present invention preferably contains a combined total of 99.75% by mass or greater of HFO-1132(E) and R32, relative to the total refrigerant, more preferably 99.9% by mass or greater, even more preferably 99.999% by mass or greater, and most preferably 99.9999% by mass or greater. The refrigerant of the present invention may also consist essentially solely of HFO-1132(E) and R32. In this case, the refrigerant of the present invention may consist solely of HFO-1132(E), R32, and unavoidable impurities. The refrigerant of the present invention may also consist solely of HFO-1132(E) and R32.

[0034] The additional refrigerant is not particularly limited and can be selected from a wide range. The mixed refrigerant may contain one type of additional refrigerant alone or two or more types.

[0035] Examples of the additional refrigerant include methylamine, acetylene, HFO-1141, HFO-1123, HFC-143a, HFC-134a, HFO-1132a, Z-HFO-1132, HFO-1243zf, HFC-245cb, HCFC-1122, HCFC-124, CFC-1113, and 3,3,3-trifluoropropyne.

[0036] 2. Refrigerant composition The refrigerant composition of the present invention contains at least the refrigerant of the present invention and can be used for the same purposes as the refrigerant of the present invention. In addition, the refrigerant composition of the present invention can also be used to obtain a refrigerator working fluid by mixing with at least refrigerator oil.

[0037] The refrigerant composition of the present invention may contain at least one other component in addition to the refrigerant of the present invention. The refrigerant composition of the present invention may contain at least one of the following other components as needed. As described above, when the refrigerant composition of the present invention is used as a working fluid in a refrigerator, it is usually mixed with at least refrigeration oil. Therefore, the refrigerant composition of the present invention preferably does not substantially contain refrigeration oil. Specifically, with respect to the refrigerant composition of the present invention, the content of refrigeration oil relative to the total refrigerant composition is preferably 1% by mass or less, more preferably 0.1% by mass or less.

[0038] 2.1 Water The refrigerant composition of the present invention may contain a trace amount of water. The water content in the refrigerant composition is preferably 0.1% by mass or less, more preferably 0.05% by mass or less, and even more preferably 0.01% by mass or less relative to the total refrigerant composition. The inclusion of a trace amount of water in the refrigerant composition stabilizes the intramolecular double bonds of the unsaturated fluorocarbon compounds that may be contained in the refrigerant, and reduces the likelihood of oxidation of the unsaturated fluorocarbon compounds, thereby improving the stability of the refrigerant composition.

[0039] 2.2 Tracer In order to track the changes in the refrigerant composition of the present invention when it undergoes dilution, contamination, or other changes, a tracer is added to the refrigerant composition of the present invention at a detectable concentration.

[0040] The refrigerant composition of the present invention may contain one type of tracer alone or two or more types of tracers.

[0041] The tracer is not particularly limited and can be appropriately selected from commonly used tracers.

[0042] Examples of tracers include hydrofluorocarbons, hydrochlorofluorocarbons, chlorofluorocarbons, hydrochlorocarbons, fluorocarbons, deuterated hydrocarbons, deuterated hydrofluorocarbons, perfluorocarbons, fluorinated ethers, brominated compounds, iodinated compounds, alcohols, aldehydes, ketones, and nitrous oxide (N2O). Particularly preferred tracers are hydrofluorocarbons, hydrochlorofluorocarbons, chlorofluorocarbons, hydrochlorocarbons, fluorocarbons, and fluorinated ethers.

[0043] As the tracer, the following compounds are preferred.

[0044] FC-14 (tetrafluoromethane, CF4) HCC-40 (Methyl Chloride, CH3Cl) HFC-23 (trifluoromethane, CHF3) HFC-41 (fluoromethane, CH3F) HFC-125 (pentafluoroethane, CF3CHF2) HFC-134a (1,1,1,2-tetrafluoroethane, CF3CH2F) HFC-134 (1,1,2,2-tetrafluoroethane, CHF2CHF2) HFC-143 (1,1,2-trifluoroethane, CHF2CH2F) HFC-152 (1,2-difluoroethane, CH2FCH2F) HFC-161 (fluoroethane, CH3CH2F) HFC-245fa (1,1,1,3,3-pentafluoropropane, CF3CH2CHF2) HFC-236fa (1,1,1,3,3,3-hexafluoropropane, CF3CH2CF3) HFC-236ea (1,1,1,2,3,3-hexafluoropropane, CF3CHFCHF2) HFC-227ea (1,1,1,2,3,3,3-heptafluoropropane, CF3CHFCF3) HCFC-22 (chlorodifluoromethane, CHClF2) HCFC-31 (chlorofluoromethane, CH2ClF) HFE-125 (trifluoromethyl-difluoromethyl ether, CF3OCHF2) HFE-134a (trifluoromethyl-fluoromethyl ether, CF3OCH2F) HFE-143a (trifluoromethyl-methyl ether, CF3OCH3) HFE-227ea (trifluoromethyl-tetrafluoroethyl ether, CF3OCHFCF3) HFE-236fa (trifluoromethyl-trifluoroethyl ether, CF3OCH2CF3) The refrigerant composition of the present invention may contain a total of about 10 parts per million (ppm) by weight or more of the tracer relative to the total refrigerant composition. Furthermore, the refrigerant composition of the present invention may contain a total of about 1000 ppm or less of the tracer relative to the total refrigerant composition. The refrigerant composition of the present invention may contain a total of preferably about 30 ppm or more, more preferably about 50 ppm or more of the tracer relative to the total refrigerant composition. The refrigerant composition of the present invention may contain a total of preferably about 500 ppm or less of the tracer relative to the total refrigerant composition, and may also contain a total of about 300 ppm or less of the tracer relative to the total refrigerant composition.

[0045] 2.3 UV fluorescent dyes The refrigerant composition of the present invention may contain a single type of ultraviolet fluorescent dye or two or more types of ultraviolet fluorescent dye.

[0046] The ultraviolet fluorescent dye is not particularly limited and can be appropriately selected from commonly used ultraviolet fluorescent dyes.

[0047] Examples of ultraviolet fluorescent dyes include naphthalimide, coumarin, anthracene, phenanthrene, xanthene, thioxanthene, benzoxanthene, fluorescein, and derivatives thereof. As ultraviolet fluorescent dyes, either or both of naphthalimide and coumarin are particularly preferred.

[0048] 2.4 Stabilizer The refrigerant composition of the present invention may contain one type of stabilizer alone or two or more types of stabilizers.

[0049] The stabilizer is not particularly limited and can be appropriately selected from commonly used stabilizers.

[0050] Examples of the stabilizer include nitro compounds, ethers, and amines.

[0051] Examples of the nitro compound include aliphatic nitro compounds such as nitromethane and nitroethane, and aromatic nitro compounds such as nitrobenzene and nitrostyrene.

[0052] Examples of the ethers include 1,4-dioxane and the like.

[0053] Examples of the amines include 2,2,3,3,3-pentafluoropropylamine and diphenylamine.

[0054] Other examples include butylated hydroxyxylene and benzotriazole.

[0055] The content of the stabilizer relative to the total refrigerant is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and preferably 5% by mass or less, more preferably 2% by mass or less.

[0056] 2.5 Inhibitors The refrigerant composition of the present invention may contain one type of polymerization inhibitor alone or two or more types thereof.

[0057] The polymerization inhibitor is not particularly limited and can be appropriately selected from commonly used polymerization inhibitors.

[0058] Examples of the polymerization inhibitor include 4-methoxy-1-naphthol, hydroquinone, hydroquinone methyl ether, dimethyl-tert-butylphenol, 2,6-di-tert-butyl-p-cresol, and benzotriazole.

[0059] The content of the polymerization inhibitor is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, relative to the total refrigerant, and preferably 5% by mass or less, more preferably 2% by mass or less.

[0060] 3. Working fluid containing refrigeration oil The working fluid containing refrigerator oil of the present invention contains at least refrigerant or refrigerant composition of the present invention and refrigerator oil, and is used as the working fluid in refrigerator. Specifically, the working fluid containing refrigerator oil of the present invention is obtained by mixing the refrigerator oil used in the compressor of refrigerator with the refrigerant or refrigerant composition. In the working fluid containing refrigerator oil, the refrigerator oil of more than 10 mass % is usually contained. In the working fluid containing refrigerator oil, the refrigerator oil of less than 50 mass % is usually contained.

[0061] 3.1 Refrigeration oil The composition of the present invention may contain one type of refrigeration oil alone or two or more types of refrigeration oil.

[0062] The refrigeration oil is not particularly limited and can be appropriately selected from commonly used refrigeration oils. If necessary, a refrigeration oil that is superior in improving compatibility with the mixture and stability of the mixture can be appropriately selected.

[0063] As the base oil of the refrigeration oil, for example, at least one selected from polyalkylene glycol (PAG), polyol ester (POE), and polyvinyl ether (PVE) is preferably used.

[0064] In addition to the base oil, the refrigeration oil may contain additives. The additive may be at least one selected from the group consisting of antioxidants, extreme pressure agents, acid scavengers, oxygen scavengers, copper passivators, rust inhibitors, oiliness agents, and defoaming agents.

[0065] From the perspective of lubrication, the refrigeration oil preferably has a kinematic viscosity of 5 cSt or more at 40° C. From the perspective of lubrication, the refrigeration oil preferably has a kinematic viscosity of 400 cSt or less at 40° C.

[0066] The working fluid containing refrigeration oil of the present invention may further contain at least one additive as needed. Examples of the additive include the following solubilizers.

[0067] 3.2 Solubilizer The refrigeration oil-containing working fluid of the present invention may contain one type of solubilizing agent alone or two or more types of solubilizing agents.

[0068] The solubilizing agent is not particularly limited and can be appropriately selected from commonly used solubilizing agents.

[0069] Examples of the solubilizing agent include polyoxyalkylene glycol ethers, amides, nitriles, ketones, chlorinated hydrocarbons, esters, lactones, aryl ethers, fluorinated ethers, and 1,1,1-trifluoroalkanes. Polyoxyalkylene glycol ethers are particularly preferred as the solubilizing agent.

[0070] The refrigerant, refrigerant composition and working fluid containing refrigeration oil of the present invention can be used as R12, R22, R134a, R404A, R407A, R407C, R407F, R407H, R410A, R413A, R417A, R422A, R422B, R422C, R422D, R423A, R424A, R426A, R427A, R It can be used as an alternative refrigerant to R430A, R434A, R437A, R438A, R448A, R449A, R449B, R449C, R452A, R452B, R454A, R454B, R454C, R455A, R465A, R474A, R479A, R502, R507, R513A, R1234yf or R1234ze.

[0071] 4. How to operate the freezer The method for operating a refrigerator of the present invention is a method for operating a refrigerator using the refrigerant of the present invention.

[0072] Specifically, the method for operating a refrigerator of the present invention includes the step of circulating the refrigerant of the present invention in the refrigerator.

[0073] Although the embodiments have been described above, it should be understood that various changes in form and details may be made without departing from the spirit and scope of the scope of the claims.

[0074] Example The following examples are given to further explain the present invention in detail, but the present invention is not limited to these examples.

[0075] HFO-1132(E) and R32, and HFO-1132a and R124 were mixed at the mass % shown in Tables 1 and 2 based on the total of these mixtures to prepare mixed refrigerants.

[0076] Various physical properties of each of these mixed refrigerants were evaluated as shown in Tables 1 to 3.

[0077] GWP, COP, Refrigeration Capacity and Condensation Glide The GWP of the mixed refrigerant was evaluated based on the values of 1 for HFO-1132(E) and the GWPs of R32, HFO-1132a, and R124, as reported in the Fourth Report of the Intergovernmental Panel on Climate Change (IPCC). The COP, refrigeration capacity, and condensation slip of the mixed refrigerant were calculated using the Reference Fluid Thermodynamic and Transport Properties Database (Refprop 10.0) from the National Institute of Science and Technology (NIST) under the following conditions using theoretical calculations of the mixed refrigerant's refrigeration cycle. The physical properties of HFO-1132(E) were obtained using measured values.

[0078] Evaporation temperature 5℃ Condensation temperature 45℃ Overheat temperature 5K Supercooling temperature 5K Compressor efficiency 70% In the following tables, "COP ratio" and "refrigeration capacity ratio" indicate ratios relative to R410A.

[0079] Allowable concentration The permissible concentration of a refrigerant mixture (Occupational Exposure Limits (OEL)) is a value evaluated using the core composition. The OEL for each refrigerant is calculated as follows.

[0080] HFO-1132 (E): 350ppm R32: 1000ppm HFO-1132a: 500ppm R124: 1000ppm The OEL of the core composition of the mixed refrigerant is calculated using the following formula.

[0081]

[0082] Where a n Indicates the OEL of each refrigerant compound, mf n Indicates the mole fraction of each refrigerant compound.

[0083] Toxicity classification A refrigerant designated "Toxicity Class A" means that the permitted concentration (Occupational Exposure Limits (OEL)) of the refrigerant mixture is 400 ppm or higher, as per the US ANSI / ASHRAE 34-2019 standard. Furthermore, a refrigerant designated "Toxicity Class B" means that the permitted concentration of the refrigerant mixture is less than 400 ppm, as per the US ANSI / ASHRAE 34-2019 standard.

[0084] [Table 1]

[0085] [Table 2]

[0086] Tables 1 and 2 show that when the refrigerant of the present invention contains 63.0% to 68.3% by mass of HFO-1132(E) relative to the total of HFO-1132(E) and R32, the refrigerant has a GWP of 250 or less, an ASHRAE toxicity classification of A, and a refrigeration capacity ratio of 108% or greater relative to R410A.

[0087] Tables 1 and 2 show that when the refrigerant of the present invention contains 70.5% to 76.5% by mass of HFO-1132(E) relative to the total of HFO-1132(E) and R32, the GWP is 200 or less, the ASHRAE toxicity classification is A, and the condensation slip is 0.12K or less, similar to R410A.

[0088] Tables 1 and 2 show that the refrigerant of the present invention has a GWP of 125 or less and an ASHRAE toxicity classification of A when containing 81.6 to 83.7 mass % of HFO-1132(E) relative to the total of HFO-1132(E) and R32.

[0089] Furthermore, when the refrigerant of the present invention was subjected to a stability test under the following conditions, it was found that, as shown in Table 3, the generation of solid matter was suppressed when the refrigerant contained water at a predetermined ratio.

[0090] <Sample Adjustment> By adding a predetermined amount of water to the composition containing HFO-1132(E) and R32 shown in Table 3, the water content was adjusted to 10, 100, 1000, and 2000 ppm by mass relative to the composition containing HFO-1132(E) and R32. The composition containing HFO-1132(E) and R32, with the water content adjusted as described above, was sealed in a container, and oxygen gas was blown into the container to adjust the oxygen gas ratio relative to the composition containing HFO-1132(E) and R32 as shown in Table 3, based on the composition containing HFO-1132(E) and R32. The above procedures yielded the fluoroethylene compositions shown in Table 3, with the water and oxygen content adjusted to the predetermined ratios.

[0091] The compositions shown in Table 3 were obtained without water and with oxygen content adjusted at a predetermined ratio, by the same method as in the above example except that no water or oxygen was added to the composition containing HFO-1132(E) and R32 used above.

[0092] Evaluation Method (Stability test of compositions containing HFO-1132(E) and R32) The compositions obtained in the above examples and comparative examples were subjected to stability tests as follows. The composition was added to a glass tube (ID8mmΦ × OD12mmΦ × L300mm) with one end sealed by fusion, resulting in an HFO-1132(E) content of 0.01 mol. The tube was sealed by fusion. The tube was then placed in a thermostatic chamber at 150°C and maintained in this state for one week. The tube was then removed from the thermostatic chamber, cooled, and its appearance was examined. The acid content in the gas within the tube was analyzed to evaluate the stability of the composition.

[0093] In the stability test of the composition, the acid content in the gas was analyzed according to the following method. Liquid nitrogen was used to completely solidify the gas trapped in the cooled tube. The tube was then unsealed and slowly thawed, and the gas was recovered in a Tedlar bag. 5 g of pure water was injected into the Tedlar bag to ensure good contact with the recovered gas, and the acid content was extracted into the pure water. The extract was then analyzed by ion chromatography to determine the fluoride ion (F - ) content (mass ppm).

[0094] [Table 3]

[0095] From the above results, it was found that the stability of the refrigerant composition is improved when the refrigerant composition contains a small amount of water.

Claims

1. A composition containing a refrigerant, characterized in that: The refrigerant contains 99.5% by mass or more of trans-1,2-difluoroethylene (HFO-1132(E)) and difluoromethane (R32) in total relative to the total refrigerant. Contains 63.0% to 68.3% by mass of HFO-1132(E) relative to the total of HFO-1132(E) and R32; Contains 70.5% to 76.5% by mass of HFO-1132(E) based on the total of HFO-1132(E) and R32; or The amount of HFO-1132(E) contained is 81.6% by mass to 83.7% by mass based on the total amount of HFO-1132(E) and R32.

2. The composition according to claim 1, wherein: The refrigerant further contains at least one selected from methylamine, acetylene, HFO-1141, HFO-1123, HFC-143a, HFC-134a, HFO-1132a, Z-HFO-1132, HFO-1243zf, HFC-245cb, HCFC-1122, HCFC-124, CFC-1113 and 3,3,3-trifluoropropyne in an amount of 0.5 mass % or less relative to the total refrigerant.

3. The composition according to claim 1 or 2, wherein: The composition further contains 0.1% by mass or less of water based on the entire composition.

4. The composition according to claim 1 or 2, wherein: As R12, R22, R134a, R404A, R407A, R407C, R407F, R407H, R410A, R413A, R417A, R422A, R422B, R422C, R422D, R423A, R424A, R426A, R427A, R430A, R434A, R43 7A, R438A, R448A, R449A, R449B, R449C, R452A, R452B, R454A, R454B, R454C, R455A, R465A, R474A, R479A, R502, R507, R513A, R1234yf or R1234ze.

5. A freezing method, characterized in that: The method comprises the step of operating a refrigeration cycle using the composition according to claim 1 or 2.

6. A freezer, characterized in that: The working fluid comprises the composition according to claim 1 or 2.

7. Use of the composition according to claim 1 or 2 as a working fluid in a refrigerator.

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