Composition containing refrigerant, use of said composition, refrigerator having said composition, and method for operating said refrigerator

The present disclosure relates to a composition comprising a refrigerant, use of the composition, a refrigerating machine having the composition, and a method for operating the refrigerating machine.

R410A is currently used as an air conditioning refrigerant for home air conditioners etc. R410A is a two-component mixed refrigerant of difluoromethane (CH 2 F 2 : HFC-32 or R32) and pentafluoroethane (C 2 HF 5 : HFC-125 or R125), and is a pseudo-azeotropic composition.

However, the global warming potential (GWP) of R410A is 2088. Due to growing concerns about global warming, R32, which has a GWP of 675, has been increasingly used.

For this reason, various low-GWP mixed refrigerants that can replace R410A have been proposed (PTL 1).

Patent Literature

PTL 1: WO2015/141678

Technical Problem

The present inventors performed independent examination, and conceived of the idea that no prior art had developed refrigerant compositions having three types of performance, i.e., a refrigerating capacity (also referred to as “cooling capacity” or “capacity”) and a coefficient of performance (COP) that are equivalent to those of R410A, and a sufficiently low GWP. An object of the present disclosure is to solve this unique problem.

Solution to Problem

Item 1 A composition comprising a refrigerant, the refrigerant comprising trans-1,2-difluoroethylene (HFO-1132(E)), trifluoroethylene (HFO-1123), 2,3,3,3-tetrafluoro-1-propene (R1234yf), and difluoromethane (R32),

wherein

when the mass % of HFO-1132(E), HFO-1123, R1234yf, and R32 based on their sum in the refrigerant is respectively represented by x, y, z, and a,

if 0<a≤11.1, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is (100−a) mass % are within the range of a figure surrounded by straight lines GI, IA, AB, BD′, D′C, and CG that connect the following 6 points:

point G (0.026a 2 −1.7478a+72.0, −0.026a 2 +0.7478a+28.0, 0.0),

point I (0.026a 2 −1.7478a+72.0, 0.0, −0.026a 2 +0.7478a+28.0),

point A (0.0134a 2 −1.9681a+68.6, 0.0, −0.0134a 2 +0.9681a+31.4),

point B (0.0, 0.0144a 2 −1.6377a+58.7, −0.0144a 2 +0.6377a+41.3),

point D′ (0.0, 0.0224a 2 +0.968a+75.4, −0.0224a 2 −1.968a+24.6), and

point C (−0.2304a 2 −0.4062a+32.9, 0.2304a 2 −0.5938a+67.1, 0.0),

or on the straight lines GI, AB, and D′C (excluding point G, point I, point A, point B, point D′, and point C);

if 11.1<a≤18.2, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines GI, IA, AB, BW, and WG that connect the following 5 points:

point G (0.02a 2 −1.6013a+71.105, −0.02a 2 +0.6013a+28.895, 0.0),

point I (0.02a 2 −1.6013a+71.105, 0.0, −0.02a 2 +0.6013a+28.895),

point A (0.0112a 2 −1.9337a+68.484, 0.0, −0.0112a 2 +0.9337a+31.516),

point B (0.0, 0.0075a 2 −1.5156a+58.199, −0.0075a 2 +0.5156a+41.801), and

point W (0.0, 100.0−a, 0.0),

or on the straight lines GI and AB (excluding point G, point I,

point A, point B, and point W);

if 18.2<a≤26.7, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines GI, IA, AB, BW, and WG that connect the following 5 points:

point G (0.0135a 2 −1.4068a+69.727, −0.0135a 2 +0.4068a+30.273, 0.0),

point I (0.0135a 2 −1.4068a+69.727, 0.0, −0.0135a 2 +0.4068a+30.273),

point A (0.0107a 2 −1.9142a+68.305, 0.0, −0.0107a 2 +0.9142a+31.695),

point B (0.0, 0.009a 2 −1.6045a+59.318, −0.009a 2 +0.6045a+40.682), and

point W (0.0, 100.0−a, 0.0),

or on the straight lines GI and AB (excluding point G, point I,

point A, point B, and point W);

if 26.7<a≤36.7, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines GI, IA, AB, BW, and WG that connect the following 5 points:

point G (0.0111a 2 −1.3152a+68.986, −0.0111a 2 +0.3152a+31.014, 0.0),

point I (0.0111a 2 −1.3152a+68.986, 0.0, −0.0111a 2 +0.3152a+31.014),

point A (0.0103a 2 −1.9225a+68.793, 0.0, −0.0103a 2 +0.9225a+31.207),

point B (0.0, 0.0046a 2 −1.41a+57.286, −0.0046a 2 +0.41a+42.714), and

point W (0.0, 100.0−a, 0.0),

or on the straight lines GI and AB (excluding point G, point I,

point A, point B, and point W); and

if 36.7<a≤46.7, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines GI, IA, AB, BW, and WG that connect the following 5 points:

point G (0.0061a 2 −0.9918a+63.902, −0.0061a 2 −0.0082a+36.098, 0.0),

point I (0.0061a 2 −0.9918a+63.902, 0.0, −0.0061a 2 −0.0082a+36.098),

point A (0.0085a 2 −1.8102a+67.1, 0.0, −0.0085a 2 +0.8102a+32.9),

point B (0.0, 0.0012a 2 −1.1659a+52.95, −0.0012a 2 +0.1659a+47.05), and

point W (0.0, 100.0−a, 0.0),

or on the straight lines GI and AB (excluding point G, point I,

point A, point B, and point W).

Item 2 A composition comprising a refrigerant, the refrigerant comprising trans-1,2-difluoroethylene (HFO-1132(E)), trifluoroethylene (HFO-1123), 2,3,3,3-tetrafluoro-1-propene (R1234yf), and difluoromethane (R32),

wherein

when the mass % of HFO-1132(E), HFO-1123, R1234yf, and R32 based on their sum in the refrigerant is respectively represented by x, y, z, and a,

if 0<a≤11.1, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is (100−a) mass % are within the range of a figure surrounded by straight lines JK′, K′B, BD′, D′C, and CJ that connect the following 5 points:

point J (0.0049a 2 −0.9645a+47.1, −0.0049a 2 −0.0355a+52.9, 0.0),

point K′ (0.0514a 2 −2.4353a+61.7, −0.0323a 2 +0.4122a+5.9, −0.0191a 2 +1.0231a+32.4),

point B (0.0, 0.0144a 2 −1.6377a+58.7, −0.0144a 2 +0.6377a+41.3),

point D′ (0.0, 0.0224a 2 +0.968a+75.4, −0.0224a 2 −1.968a+24.6), and

point C (−0.2304a 2 −0.4062a+32.9, 0.2304a 2 −0.5938a+67.1, 0.0),

or on the straight lines JK′, K′B, and D′C (excluding point J, point B, point D′, and point C);

if 11.1<a≤18.2, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines JK′, K′B, BW, and WJ that connect the following 4 points:

point J (0.0243a 2 −1.4161a+49.725, −0.0243a 2 +0.4161a+50.275, 0.0),

point K′ (0.0341a 2 −2.1977a+61.187, −0.0236a 2 +0.34a+5.636, −0.0105a 2 +0.8577a+33.177),

point B (0.0, 0.0075a 2 −1.5156a+58.199, −0.0075a 2 +0.5156a+41.801), and

point W (0.0, 100.0−a, 0.0),

or on the straight lines JK′ and K′B (excluding point J, point B, and point W);

if 18.2<a≤26.7, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines JK′, K′B, BW, and WJ that connect the following 4 points:

point J (0.0246a 2 −1.4476a+50.184, −0.0246a 2 +0.4476a+49.816, 0.0),

point K′ (0.0196a 2 −1.7863a+58.515, −0.0079a 2 −0.1136a+8.702, −0.0117a 2 +0.8999a+32.783),

point B (0.0, 0.009a 2 −1.6045a+59.318, −0.009a 2 +0.6045a+40.682), and

point W (0.0, 100.0−a, 0.0),

or on the straight lines JK′ and K′B (excluding point J, point B, and point W);

if 26.7<a≤36.7, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines JK′, K′A, AB, BW, and WJ that connect the following 5 points:

point J (0.0183a 2 −1.1399a+46.493, −0.0183a 2 +0.1399a+53.507, 0.0),

point K′ (−0.0051a 2 +0.0929a+25.95, 0.0, 0.0051a 2 −1.0929a+74.05),

point A (0.0103a 2 −1.9225a+68.793, 0.0, −0.0103a 2 +0.9225a+31.207),

point B (0.0, 0.0046a 2 −1.41a+57.286, −0.0046a 2 +0.41a+42.714), and

point W (0.0, 100.0−a, 0.0),

or on the straight lines JK′, K′A, and AB (excluding point J, point B, and point W); and

if 36.7<a≤46.7, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines JK′, K′A, AB, BW, and WJ that connect the following 5 points:

point J (−0.0134a 2 +1.0956a+7.13, 0.0134a 2 −2.0956a+92.87, 0.0),

point K′ (−0.1892a+29.443, 0.0, −0.8108a+70.557),

point A (0.0085a 2 −1.8102a+67.1, 0.0, −0.0085a 2 +0.8102a+32.9),

point B (0.0, 0.0012a 2 −1.1659a+52.95, −0.0012a 2 +0.1659a+47.05), and

point W (0.0, 100.0−a, 0.0),

or on the straight lines JK′, K′A, and AB (excluding point J, point B, and point W).

Item 3 A composition comprising a refrigerant, the refrigerant comprising trans-1,2-difluoroethylene (HFO-1132(E)), trifluoroethylene (HFO-1123), 2,3,3,3-tetrafluoro-1-propene (R1234yf), and R32,

wherein

when the mass % of HFO-1132(E), HFO-1123, R1234yf, and R32 based on their sum in the refrigerant is respectively represented by x, y, z, and a,

if 0<a≤10.0, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is (100−a) mass % are within the range of a figure surrounded by straight lines that connect the following 4 points:

point a (0.02a 2 −2.46a+93.4, 0, −0.02a 2 +2.46a+6.6),

point b′ (−0.008a 2 −1.38a+56, 0.018a 2 −0.53a+26.3, −0.01a 2 +1.91a+17.7),

point c (−0.016a 2 +1.02a+77.6, 0.016a 2 −1.02a+22.4, 0), and

point o (100.0−a, 0.0, 0.0),

or on the straight lines oa, ab′, and b′c (excluding point o and point c);

if 10.0<a≤16.5, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines that connect the following 4 points:

point a (0.0244a 2 −2.5695a+94.056, 0, −0.0244a 2 +2.5695a+5.944),

point b′ (0.1161a 2 −1.9959a+59.749, 0.014a 2 −0.3399a+24.8, −0.1301a 2 +2.3358a+15.451),

point c (−0.0161a 2 +1.02a+77.6, 0.0161a 2 −1.02a+22.4, 0), and

point o (100.0−a, 0.0, 0.0),

or on the straight lines oa, ab′, and b′c (excluding point o and point c); or

if 16.5<a≤21.8, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines that connect the following 4 points:

point a (0.0161a 2 −2.3535a+92.742, 0, −0.0161a 2 +2.3535a+7.258),

point b′ (−0.0435a 2 −0.0435a+50.406, −0.0304a 7 +1.8991a−0.0661, 0.0739a 2 −1.8556a+49.6601),

point c (−0.0161a 2 +0.9959a+77.851, 0.0161a 2 −0.9959a+22.149, 0), and

point o (100.0−a, 0.0, 0.0),

or on the straight lines oa, ab′, and b′c (excluding point o and point c).

Item 4 The composition according to any one of Items 1 to 3, for use as a working fluid for a refrigerating machine, wherein the composition further comprises a refrigerant oil.

Item 5 The composition according to any one of Items 1 to 4, for use as an alternative refrigerant for R410A.

Item 6 Use of the composition according to any one of Items 1 to 4 as an alternative refrigerant for R410A.

Item 7 A refrigerating machine comprising the composition according to any one of Items 1 to 4 as a working fluid.

Item 8 A method for operating a refrigerating machine, comprising the step of circulating the composition according to any one of Items 1 to 4 as a working fluid in a refrigerating machine.

Advantageous Effects of Invention

The refrigerant according to the present disclosure has three types of performance, i.e., a refrigerating capacity and a coefficient of performance that are equivalent to those of R410A, and a sufficiently low GWP.

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

FIG. 2 is a diagram showing points A to C, D′, G, I, J, and K′, 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−a) mass %.

FIG. 3 is a diagram showing points A to C, D′, G, I, J, and K′, 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 92.9 mass % (the content of R32 is 7.1 mass %).

FIG. 4 is a diagram showing points A to C, D′, G, I, J, K′, and W, 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 88.9 mass % (the content of R32 is 11.1 mass %).

FIG. 5 is a diagram showing points A, B, G, I, J, K′, and W, 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 85.5 mass % (the content of R32 is 14.5 mass %).

FIG. 6 is a diagram showing points A, B, G, I, J, K′, and W, 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 81.8 mass % (the content of R32 is 18.2 mass %).

FIG. 7 is a diagram showing points A, B, G, I, J, K′, and W, 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 78.1 mass % (the content of R32 is 21.9 mass %).

FIG. 8 is a diagram showing points A, B, G, I, J, K′, and W, 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 73.3 mass % (the content of R32 is 26.7 mass %).

FIG. 9 is a diagram showing points A, B, G, I, J, K′, and W, 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 70.7 mass % (the content of R32 is 29.3 mass %).

FIG. 10 is a diagram showing points A, B, G, I, J, K′, and W, 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 63.3 mass % (the content of R32 is 36.7 mass %).

FIG. 11 is a diagram showing points A, B, G, I, J, K′, and W, 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 55.9 mass % (the content of R32 is 44.1 mass %).

FIG. 12 is a diagram showing points A, B, G, I, J, K′, and W, 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 52.2 mass % (the content of R32 is 47.8 mass %).

The present inventors conducted intensive study to solve the above problem, and consequently found that a mixed refrigerant comprising trans-1,2-difluoroethylene (HFO-1132(E)), 2,3,3,3-tetrafluoro-1-propene (R1234yf), trifluoroethylene (HFO-1123), and difluoromethane (R32) has the above properties.

The present disclosure has been completed as a result of further research based on this finding. The present disclosure includes the following embodiments.

Definition of Terms

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.

The term “alternative” also includes a second type of “alternative,” which means that equipment designed for operation using the second refrigerant is operated for the same use as the existing use with the first refrigerant by using the second refrigerant. This type of alternative means that the same use is achieved with an alternative refrigerant.

In the present specification, the term “refrigerating machine” refers to machines in general that draw heat from an object or space to make its temperature lower than the temperature of ambient air, and maintain a low temperature. In other words, refrigerating machines refer to conversion machines that gain energy from the outside to do work, and that perform energy conversion, in order to transfer heat from where the temperature is lower to where the temperature is higher.

In the present specification, a refrigerant having a “WCF lower flammability” means that the most flammable composition (worst case of formulation for flammability: WCF) has a burning velocity of 10 cm/s or less according to the US ANSI/ASHRAE Standard 34-2013. Further, in the present specification, a refrigerant having “ASHRAE lower flammability” means that the burning velocity of WCF is 10 cm/s or less, that the most flammable fraction composition (worst case of fractionation for flammability: WCFF), which is specified by performing a leakage test during storage, shipping, or use based on ANSI/ASHRAE 34-2013 using WCF, has a burning velocity of 10 cm/s or less, and that flammability classification according to the US ANSI/ASHRAE Standard 34-2013 is determined to be classified as “Class 2L.”

1. Refrigerant

1.1 Refrigerant Component

The refrigerant according to the present disclosure is a composition comprising trans-1,2-difluoroethylene (HFO-1132(E)), trifluoroethylene (HFO-1123), 2,3,3,3-tetrafluoro-1-propene (R1234yf), and difluoromethane (R32), and satisfies the following requirements. The refrigerant according to the present disclosure has various properties that are desirable as an alternative refrigerant for R410A; i.e. it has a coefficient of performance and a refrigerating capacity that are equivalent to those of R410A, and a sufficiently low GWP.

Requirements

When the mass % of HFO-1132(E), HFO-1123, R1234yf, and R32 based on their sum is respectively represented by x, y, z, and a,

if 0<a≤11.1, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is (100−a) mass % are within the range of a figure surrounded by straight lines GI, IA, AB, BD′, D′C, and CG that connect the following 6 points:

point G (0.026a 2 −1.7478a+72.0, −0.026a 2 +0.7478a+28.0, 0.0),

point I (0.026a 2 −1.7478a+72.0, 0.0, −0.026a 2 +0.7478a+28.0),

point A (0.0134a 2 −1.9681a+68.6, 0.0, −0.0134a 2 +0.9681a+31.4),

point B (0.0, 0.0144a 2 −1.6377a+58.7, −0.0144a 2 +0.6377a+41.3),

point D′ (0.0, 0.0224a 2 +0.968a+75.4, −0.0224a 2 −1.968a+24.6), and

point C (−0.2304a 2 −0.4062a+32.9, 0.2304a 2 −0.5938a+67.1, 0.0),

or on the straight lines GI, AB, and D′C (excluding point G, point I, point A, point B, point D′, and point C);

if 11.1<a≤18.2, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines GI, IA, AB, BW, and WG that connect the following 5 points:

point G (0.02a 2 −1.6013a+71.105, −0.02a 2 +0.6013a+28.895, 0.0),

point I (0.02a 2 −1.6013a+71.105, 0.0, −0.02a 2 +0.6013a+28.895),

point A (0.0112a 2 −1.9337a+68.484, 0.0, −0.0112a 2 +0.9337a+31.516),

point B (0.0, 0.0075a 2 −1.5156a+58.199, −0.0075a 2 +0.5156a+41.801) and

point W (0.0, 100.0−a, 0.0),

or on the straight lines GI and AB (excluding point G, point I,

point A, point B, and point W);

if 18.2<a≤26.7, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines GI, IA, AB, BW, and WG that connect the following 5 points:

point G (0.0135a 2 −1.4068a+69.727, −0.0135a 2 +0.4068a+30.273, 0.0),

point I (0.0135a 2 −1.4068a+69.727, 0.0, −0.0135a 2 +0.4068a+30.273),

point A (0.0107a 2 −1.9142a+68.305, 0.0, −0.0107a 2 +0.9142a+31.695),

point B (0.0, 0.009a 2 −1.6045a+59.318, −0.009a 2 +0.6045a+40.682) and

point W (0.0, 100.0−a, 0.0),

or on the straight lines GI and AB (excluding point G, point I,

point A, point B, and point W);

if 26.7<a≤36.7, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines GI, IA, AB, BW, and WG that connect the following 5 points:

point G (0.0111a 2 −1.3152a+68.986, −0.0111a 2 +0.3152a+31.014, 0.0),

point I (0.0111a 2 −1.3152a+68.986, 0.0, −0.0111a 2 +0.3152a+31.014),

point A (0.0103a 2 −1.9225a+68.793, 0.0, −0.0103a 2 +0.9225a+31.207),

point B (0.0, 0.0046a 2 −1.41a+57.286, −0.0046a 2 +0.41a+42.714) and

point W (0.0, 100.0−a, 0.0),

or on the straight lines GI and AB (excluding point G, point I,

point A, point B, and point W); and

if 36.7<a≤46.7, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines GI, IA, AB, BW, and WG that connect the following 5 points:

point G (0.0061a 2 −0.9918a+63.902, −0.0061a 2 −0.0082a+36.098, 0.0),

point I (0.0061a 2 −0.9918a+63.902, 0.0, −0.0061a 2 −0.0082a+36.098),

point A (0.0085a 2 −1.8102a+67.1, 0.0, −0.0085a 2 +0.8102a+32.9),

point B (0.0, 0.0012a 2 −1.1659a+52.95, −0.0012a 2 +0.1659a+47.05) and

point W (0.0, 100.0−a, 0.0),

or on the straight lines GI and AB (excluding point G, point I,

point A, point B, and point W). When the refrigerant according to the present disclosure satisfies the above requirements, it has a refrigerating capacity ratio of 85% or more relative to that of R410A, and a COP ratio of 92.5% or more relative to that of R410A, and further ensures a WCF lower flammability.

The refrigerant according to the present disclosure is preferably a refrigerant wherein

when the mass % of HFO-1132(E), HFO-1123, and R1234yf based on their sum is respectively represented by x, y, and z,

if 0<a≤11.1, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is (100−a) mass % are within the range of a figure surrounded by straight lines JK′, K′B, BD′, D′C, and CJ that connect the following 5 points:

point J (0.0049a 2 −0.9645a+47.1, −0.0049a 2 −0.0355a+52.9, 0.0),

point K′ (0.0514a 2 −2.4353a+61.7, −0.0323a 2 +0.4122a+5.9, −0.0191a 2 +1.0231a+32.4),

point B (0.0, 0.0144a 2 −1.6377a+58.7, −0.0144a 2 +0.6377a+41.3),

point D′ (0.0, 0.0224a 2 +0.968a+75.4, −0.0224a 2 −1.968a+24.6), and

point C (−0.2304a 2 −0.4062a+32.9, 0.2304a 2 −0.5938a+67.1, 0.0),

or on the straight lines JK′, K′B, and D′C (excluding point J,

point B, point D′, and point C);

if 11.1<a≤18.2, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines JK′, K′B, BW, and WJ that connect the following 4 points:

point J (0.0243a 2 −1.4161a+49.725, −0.0243a 2 +0.4161a+50.275, 0.0),

point K′ (0.0341a 2 −2.1977a+61.187, −0.0236a 2 +0.34a+5.636, −0.0105a 2 +0.8577a+33.177),

point B (0.0, 0.0075a 2 −1.5156a+58.199, −0.0075a 2 +0.5156a+41.801) and

point W (0.0, 100.0−a, 0.0),

or on the straight lines JK′ and K′B (excluding point J, point B, and point W);

if 18.2<a≤26.7, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines JK′, K′B, BW, and WJ that connect the following 4 points:

point J (0.0246a 2 −1.4476a+50.184, −0.0246a 2 +0.4476a+49.816, 0.0),

point K′ (0.0196a 2 −1.7863a+58.515, −0.0079a 2 −0.1136a+8.702, −0.0117a 2 +0.8999a+32.783),

point B (0.0, 0.009a 2 −1.6045a+59.318, −0.009a 2 +0.6045a+40.682) and

point W (0.0, 100.0−a, 0.0),

or on the straight lines JK′ and K′B (excluding point J, point B, and point W);

if 26.7<a≤36.7, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines JK′, K′A, AB, BW, and WJ that connect the following 5 points:

point J (0.0183a 2 −1.1399a+46.493, −0.0183a 2 +0.1399a+53.507, 0.0),

point K′ (−0.0051a 2 +0.0929a+25.95, 0.0, 0.0051a 2 −1.0929a+74.05),

point A (0.0103a 2 −1.9225a+68.793, 0.0, −0.0103a 2 +0.9225a+31.207),

point B (0.0, 0.0046a 2 −1.41a+57.286, −0.0046a 2 +0.41a+42.714) and

point W (0.0, 100.0−a, 0.0),

or on the straight lines JK′, K′A, and AB (excluding point J, point B, and point W); and

if 36.7<a≤46.7, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines JK′, K′A, AB, BW, and WJ that connect the following 5 points:

point J (−0.0134a 2 +1.0956a+7.13, 0.0134a 2 −2.0956a+92.87, 0.0),

point K′ (−0.1892a+29.443, 0.0, −0.8108a+70.557),

point A (0.0085a 2 −1.8102a+67.1, 0.0, −0.0085a 2 +0.8102a+32.9),

point B (0.0, 0.0012a 2 −1.1659a+52.95, −0.0012a 2 +0.1659a+47.05) and

point W (0.0, 100.0−a, 0.0),

or on the straight lines JK′, K′A, and AB (excluding point J, point B, and point W). When the refrigerant according to the present disclosure satisfies the above requirements, it has a refrigerating capacity ratio of 85% or more relative to that of R410A, and a COP ratio of 92.5% or more relative to that of R410A. Additionally, the refrigerant has a WCF lower flammability and a WCFF lower flammability, and is classified as “Class 2L,” which is a lower flammable refrigerant according to the ASHRAE standard.

When the refrigerant according to the present disclosure further contains R32 in addition to HFO-1132 (E), HFO-1123, and R1234yf, the refrigerant may be a refrigerant wherein when the mass % of HFO-1132(E), HFO-1123, R1234yf, and R32 based on their sum is respectively represented by x, y, z, and a,

if 0<a≤10.0, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is (100−a) mass % are within the range of a figure surrounded by straight lines that connect the following 4 points:

point a (0.02a 2 −2.46a+93.4, 0, −0.02a 2 +2.46a+6.6),

point b′ (−0.008a 2 −1.38a+56, 0.018a 2 −0.53a+26.3, −0.01a 2 +1.91a+17.7),

point c (−0.016a 2 +1.02a+77.6, 0.016a 2 −1.02a+22.4, 0), and

point o (100.0−a, 0.0, 0.0)

or on the straight lines oa, ab′, and b′c (excluding point o and point c);

if 10.0<a≤16.5, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines that connect the following 4 points:

point a (0.0244a 2 −2.5695a+94.056, 0, −0.0244a 2 +2.5695a+5.944),

point b′ (0.1161a 2 −1.9959a+59.749, 0.014a 2 −0.3399a+24.8, −0.1301a 2 +2.3358a+15.451),

point c (−0.0161a 2 +1.02a+77.6, 0.0161a 2 −1.02a+22.4, 0), and

point o (100.0−a, 0.0, 0.0),

or on the straight lines oa, ab′, and b′c (excluding point o and point c); or

if 16.5<a≤21.8, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines that connect the following 4 points:

point a (0.0161a 2 −2.3535a+92.742, 0, −0.0161a 2 +2.3535a+7.258),

point b′ (−0.0435a 2 −0.0435a+50.406, 0.0304a 2 +1.8991a−0.0661, 0.0739a 2 −1.8556a+49.6601),

point c (−0.0161a 2 +0.9959a+77.851, 0.0161a 2 −0.9959a+22.149, 0), and

point o (100.0−a, 0.0, 0.0),

or on the straight lines oa, ab′, and b′c (excluding point o and point c). Note that when point b in the ternary composition diagram is defined as a point where a refrigerating capacity ratio of 95% relative to that of R410A and a COP ratio of 95% relative to that of R410A are both achieved, point b′ is the intersection of straight line ab and an approximate line formed by connecting the points where the COP ratio relative to that of R410A is 95%. When the refrigerant according to the present disclosure meets the above requirements, the refrigerant has a refrigerating capacity ratio of 95% or more relative to that of R410A, and a COP ratio of 95% or more relative to that of R410A.

The refrigerant according to the present disclosure may further comprise other additional refrigerants in addition to HFO-1132(E), HFO-1123, R1234yf, and R32 as long as the above properties and effects are not impaired. In this respect, the refrigerant according to the present disclosure preferably comprises HFO-1132(E), HFO-1123, R1234yf, and R32 in a total amount of 99.5 mass % or more, more preferably 99.75 mass % or more, and still more preferably 99.9 mass % or more, based on the entire refrigerant.

The refrigerant according to the present disclosure may comprise HFO-1132(E), HFO-1123, R1234yf, and R32 in a total amount of 99.5 mass % or more, 99.75 mass % or more, or 99.9 mass % or more, based on the entire refrigerant.

Additional refrigerants are not particularly limited and can be widely selected. The mixed refrigerant may contain one additional refrigerant, or two or more additional refrigerants.

1.2. Use

The refrigerant according to the present disclosure can be preferably used as a working fluid in a refrigerating machine.

The composition according to the present disclosure is suitable for use as an alternative refrigerant for R410A.

2. Refrigerant Composition

The refrigerant composition according to the present disclosure comprises at least the refrigerant according to the present disclosure, and can be used for the same use as the refrigerant according to the present disclosure. Moreover, the refrigerant composition according to the present disclosure can be further mixed with at least a refrigeration oil to thereby obtain a working fluid for a refrigerating machine.

The refrigerant composition according to the present disclosure further comprises at least one other component in addition to the refrigerant according to the present disclosure. The refrigerant composition according to the present disclosure may comprise at least one of the following other components, if necessary. As described above, when the refrigerant composition according to the present disclosure is used as a working fluid in a refrigerating machine, it is generally used as a mixture with at least a refrigeration oil. Therefore, it is preferable that the refrigerant composition according to the present disclosure does not substantially comprise a refrigeration oil. Specifically, in the refrigerant composition according to the present disclosure, the content of the refrigeration oil based on the entire refrigerant composition is preferably 0 to 1 mass %, and more preferably 0 to 0.1 mass %.

2.1. Water

The refrigerant composition according to the present disclosure may contain a small amount of water. The water content of the refrigerant composition is preferably 0.1 mass % or less based on the entire refrigerant. A small amount of water contained in the refrigerant composition stabilizes double bonds in the molecules of unsaturated fluorocarbon compounds that can be present in the refrigerant, and makes it less likely that the unsaturated fluorocarbon compounds will be oxidized, thus increasing the stability of the refrigerant composition.

2.2. Tracer

A tracer is added to the refrigerant composition according to the present disclosure at a detectable concentration such that when the refrigerant composition has been diluted, contaminated, or undergone other changes, the tracer can trace the changes.

The refrigerant composition according to the present disclosure may comprise a single tracer, or two or more tracers.

The tracer is not limited, and can be suitably selected from commonly used tracers.

Examples of tracers include hydrofluorocarbons, hydrochlorofluorocarbons, chlorofluorocarbons, hydrochlorocarbons, fluorocarbons, deuterated hydrocarbons, deuterated hydrofluorocarbons, perfluorocarbons, fluoroethers, brominated compounds, iodinated compounds, alcohols, aldehydes, ketones, and nitrous oxide (N 2 O). The tracer is particularly preferably a hydrofluorocarbon, a hydrochlorofluorocarbon, a chlorofluorocarbon, a hydrochlorocarbon, a fluorocarbcn, or a fluoroether.

The following compounds are preferable as the tracer.

FC-14 (tetrafluoromethane, CF 4 )

HCC-40 (chloromethane, CH 3 Cl)

HFC-23 (trifluoromethane, CHF 3 )

HFC-41 (fluoromethane, CH 3 Cl)

HFC-125 (pentafluoroethane, CF 3 CHF 2 )

HFC-134a (1,1,1,2-tetrafluoroethane, CF 3 CH 2 F)

HFC-134 (1,1,2,2-tetrafluoroethane, CHF 2 CHF 2 )

HFC-143a (1,1,1-trifluoroethane, CF 3 CH 3 )

HFC-143 (1,1,2-trifluoroethane, CHF 2 CH 2 F)

HFC-152a (1,1-difluoroethane, CHF 2 CH 3 )

HFC-152 (1,2-difluoroethane, CH 2 FCH 2 F)

HFC-161 (fluoroethane, CH 3 CH 2 F)

HFC-245fa (1,1,1,3,3-pentafluoropropane, CF 3 CH 2 CHF 2 )

HFC-236fa (1,1,1,3,3,3-hexafluoropropane, CF 3 CH 2 CF 3 )

HFC-236ea (1,1,1,2,3,3-hexafluoropropane, CF 3 CHFCHF 2 )

HFC-227ea (1,1,1,2,3,3,3-heptafluoropropane, CF 3 CHFCF 3 )

HCFC-22 (chlorodifluoromethane, CHClF 2 )

HCFC-31 (chlorofluoromethane, CH 2 ClF)

CFC-1113 (chlorotrifluoroethylene, CF 2 ═CClF)

HFE-125 (trifluoromethyl-difluoromethyl ether, CF 3 OCHF 2 )

HFE-134a (trifluoromethyl-fluoromethyl ether, CF 3 OCH 2 F)

HFE-143a (trifluoromethyl-methyl ether, CF 3 OCH 3 )

HFE-227ea (trifluoromethyl-tetrafluoroethyl ether, CF 3 OCHFCF 3 )

HFE-236fa (trifluoromethyl-trifluoroethyl ether, CF 3 OCH 2 CF 3 )

The refrigerant composition according to the present disclosure may contain one or more tracers at a total concentration of about 10 parts per million by weight (ppm) to about 1000 ppm based on the entire refrigerant composition. The refrigerant composition according to the present disclosure may preferably contain one or more tracers at a total concentration of about 30 ppm to about 500 ppm, and more preferably about 50 ppm to about 300 ppm, based on the entire refrigerant composition.

2.3. Ultraviolet Fluorescent Dye

The refrigerant composition according to the present disclosure may comprise a single ultraviolet fluorescent dye, or two or more ultraviolet fluorescent dyes.

The ultraviolet fluorescent dye is not limited, and can be suitably selected from commonly used ultraviolet fluorescent dyes.

Examples of ultraviolet fluorescent dyes include naphthalimide, coumarin, anthracene, phenanthrene, xanthene, thioxanthene, naphthoxanthene, fluorescein, and derivatives thereof. The ultraviolet fluorescent dye is particularly preferably either naphthalimide or coumarin, or both.

2.4. Stabilizer

The refrigerant composition according to the present disclosure may comprise a single stabilizer, or two or more stabilizers.

The stabilizer is not limited, and can be suitably selected from commonly used stabilizers.

Examples of stabilizers include nitro compounds, ethers, and amines.

Examples of nitro compounds include aliphatic nitro compounds, such as nitromethane and nitroethane; and aromatic nitro compounds, such as nitro benzene and nitro styrene.

Examples of ethers include 1,4-dioxane.

Examples of amines include 2,2,3,3,3-pentafluoropropylamine and diphenylamine.

Examples of stabilizers also include butylhydroxyxylene and benzotriazole.

The content of the stabilizer is not limited. Generally, the content of the stabilizer is preferably 0.01 to 5 mass %, and more preferably 0.05 to 2 mass %, based on the entire refrigerant.

2.5. Polymerization Inhibitor

The refrigerant composition according to the present disclosure may comprise a single polymerization inhibitor, or two or more polymerization inhibitors.

The polymerization inhibitor is not limited, and can be suitably selected from commonly used polymerization inhibitors.

Examples of polymerization inhibitors include 4-methoxy-1-naphthol, hydroquinone, hydroquinone methyl ether, dimethyl-t-butylphenol, 2,6-di-tert-butyl-p-cresol, and benzotriazole.

The content of the polymerization inhibitor is not limited. Generally, the content of the polymerization inhibitor is preferably 0.01 to 5 mass %, and more preferably 0.05 to 2 mass %, based on the entire refrigerant.

3. Refrigeration Oil-Containing Working Fluid

The refrigeration oil-containing working fluid according to the present disclosure comprises at least the refrigerant or refrigerant composition according to the present disclosure and a refrigeration oil, for use as a working fluid in a refrigerating machine. Specifically, the refrigeration oil-containing working fluid according to the present disclosure is obtained by mixing a refrigeration oil used in a compressor of a refrigerating machine with the refrigerant or the refrigerant composition. The refrigeration oil-containing working fluid generally comprises 10 to 50 mass % of refrigeration oil.

3.1. Refrigeration Oil

The composition according to the present disclosure may comprise a single refrigeration oil, or two or more refrigeration oils.

The refrigeration oil is not limited, and can be suitably selected from commonly used refrigeration oils. In this case, refrigeration oils that are superior in the action of increasing the miscibility with the mixture and the stability of the mixture, for example, are suitably selected as necessary.

The base oil of the refrigeration oil is preferably, for example, at least one member selected from the group consisting of polyalkylene glycols (PAG), polyol esters (POE), and polyvinyl ethers (PVE).

The refrigeration oil may further contain additives in addition to the base oil. The additive may be at least one member selected from the group consisting of antioxidants, extreme-pressure agents, acid scavengers, oxygen scavengers, copper deactivators, rust inhibitors, oil agents, and antifoaming agents.

A refrigeration oil with a kinematic viscosity of 5 to 400 cSt at 40° C. is preferable from the standpoint of lubrication.

The refrigeration oil-containing working fluid according to the present disclosure may further optionally contain at least one additive. Examples of additives include compatibilizing agents described below.

3.2. Compatibilizing Agent

The refrigeration oil-containing working fluid according to the present disclosure may comprise a single compatibilizing agent, or two or more compatibilizing agents.

The compatibilizing agent is not limited, and can be suitably selected from commonly used compatibilizing agents.

Examples of compatibilizing agents include polyoxyalkylene glycol ethers, amides, nitriles, ketones, chlorocarbons, esters, lactones, aryl ethers, fluoroethers, and 1,1,1-trifluoroalkanes. The compatibilizing agent is particularly preferably a polyoxyalkylene glycol ether.

4. Method for Operating Refrigerating Machine

The method for operating a refrigerating machine according to the present disclosure is a method for operating a refrigerating machine using the refrigerant according to the present disclosure.

Specifically, the method for operating a refrigerating machine according to the present disclosure comprises the step of circulating the refrigerant according to the present disclosure in a refrigerating machine.

Embodiments are described above; however, it will be understood that various changes in forms and details can be made without departing from the spirit and scope of the claims.

The present disclosure is described in more detail below with reference to Examples. However, the present disclosure is not limited to the Examples.

Mixed refrigerants were prepared by mixing HFO-1132(E), HFO-1123, R1234yf, and R32 at mass % based on their sum shown in Tables 1 to 58.

The GWP of compositions each comprising a mixture of R410A (R32=50%/R125=50%) was evaluated based on the values stated in the Intergovernmental Panel on Climate Change (IPCC), fourth report. The GWP of HFO-1132(E), which was not stated therein, was assumed to be 1 from HFO-1132a (GWP=1 or less) and HFO-1123 (GWP=0.3, described in PTL 1). The refrigerating capacity of compositions each comprising R410A and a mixture of HFO-1132(E) and HFO-1123 was determined by performing theoretical refrigeration cycle calculations for the mixed refrigerants using the National Institute of Science and Technology (NIST) and Reference Fluid Thermodynamic and Transport Properties Database (Refprop 9.0) under the following conditions.

For each of these mixed refrigerants, the COP ratio and the refrigerating capacity ratio relative to those of R410 were obtained. Calculation was conducted under the following conditions.

Evaporating temperature: 5° C.

Condensation temperature: 45° C.

Superheating temperature: 5 K

Subcooling temperature: 5 K

Compressor efficiency: 70%

Tables 1 to 58 show the resulting values together with the GWP of each mixed refrigerant. The COP and refrigerating capacity are ratios relative to R410A.

The coefficient of performance (COP) was determined by the following formula.

COP=(refrigerating capacity or heating capacity)/power consumption

The above results indicate that the refrigerating capacity ratio relative to R410A is 85% or more in the following cases:

When the mass % of HFO-1132(E), HFO-1123, R1234yf, and R32 based on their sum is respectively represented by x, y, z, and a, in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is (100−a) mass %, a straight line connecting a point (0.0, 100.0−a, 0.0) and a point (0.0, 0.0, 100.0−a) is the base, and the point (0.0, 100.0−a, 0.0) is on the left side, if 0<a≤11.1, coordinates (x, y, z) in the ternary composition diagram are on, or on the left side of, a straight line AB that connects point A (0.0134a 2 −1.9681a+68.6, 0.0, −0.0134a 2 +0.9681a+31.4) and point B (0.0, 0.0144a 2 −1.6377a+58.7, −0.0144a 2 +0.6377a+41.3);

if 11.1<a≤18.2, coordinates (x,y,z) in the ternary composition diagram are on, or on the left side of, a straight line AB that connects point A (0.0112a 2 −1.9337a+68.484, 0.0, −0.0112a 2 +0.9337a+31.516) and point B (0.0, 0.0075a 2 −1.5156a+58.199, −0.0075a 2 +0.5156a+41.801);

if 18.2a<a≤26.7, coordinates (x,y,z) in the ternary composition diagram are on, or on the left side of, a straight line AB that connects point A (0.0107a 2 −1.9142a+68.305, 0.0, −0.0107a 2 +0.9142a+31.695) and point B (0.0, 0.009a 2 −1.6045a+59.318, −0.009a 2 +0.6045a+40.682);

if 26.7<a≤36.7, coordinates (x,y,z) in the ternary composition diagram are on, or on the left side of, a straight line AB that connects point A (0.0103a 2 −1.9225a+68.793, 0.0, −0.0103a 2 +0.9225a+31.207) and point B (0.0, 0.0046a 2 −1.41a+57.286, −0.0046a 2 +0.41a+42.714); and

if 36.7<a≤46.7, coordinates (x,y,z) in the ternary composition diagram are on, or on the left side of, a straight line AB that connects point A (0.0085a 2 −1.8102a+67.1, 0.0, −0.0085a 2 +0.8102a+32.9) and point B (0.0, 0.0012a 2 −1.1659a+52.95, −0.0012a 2 +0.1659a+47.05).

Actual points having a refrigerating capacity ratio of 85% or more form a curved line that connects point A and point B, and that extends toward the 1234yf side. Accordingly, when coordinates are on, or on the left side of, the straight line AB, the refrigerating capacity ratio relative to R410A is 85% or more.

Similarly, it was also found that in the ternary composition diagram, if 0<a≤11.1, when coordinates (x,y,z) are on, or on the left side of, a straight line D′C that connects point D′ (0.0, 0.0224a 2 +0.968a+75.4, −0.0224a 2 −1.968a+24.6) and point C (−0.2304a 2 −0.4062a+32.9, 0.2304a 2 −0.5938a+67.1, 0.0); or if 11.1<a≤46.7, when coordinates are in the entire region, the COP ratio relative to that of R410A is 92.5% or more. In FIG. 2 , the COP ratio of 92.5% ox more forms a

curved line CD. In FIG. 2 , an approximate line formed by connecting three points: point C (32.9, 67.1, 0.0) and points (26.6, 68.4, 5) (19.5, 70.5, 10) where the COP ratio is 92.5% when the concentration of R1234yf is 5 mass % and 10 mass was obtained, and a straight line that connects point C and point D′ (0, 75.4, 24.6), which is the intersection of the approximate line and a point where the concentration of HFO-1132(E) is 0.0 mass % was defined as a line segment D′C. In FIG. 3 , point D′(0, 83.4, 9.5) was similarly obtained from an approximate curve formed by connecting point C (18.4, 74.5, 0) and points (13.9, 76.5, 2.5) (8.7, 79.2, 5) where the COP ratio is 92.5%, and a straight line that connects point C and point D′ was defined as the straight line D′C.

The composition of each mixture was defined as WCF. A leak simulation was performed using NIST Standard Reference Database REFLEAK Version 4.0 under the conditions of Equipment, Storage, Shipping, Leak, and Recharge according to the ASHRAE Standard 34-2013. The most flammable fraction was defined as WCFF.

For the flammability, the burning velocity was measured according to the ANSI/ASHRAE Standard 34-2013. Both WCF and WCFF having a burning velocity of 10 cm/s or less were determined to be classified as “Class 2L (lower flammability).”

A burning velocity test was performed using the apparatus shown in FIG. 1 in the following manner. First, the mixed refrigerants used had a purity of 99.5% or more, and were degassed by repeating a cycle of freezing, pumping, and thawing until no traces of air were observed on the vacuum gauge. The burning velocity was measured by the closed method. The initial temperature was ambient temperature. Ignition was performed by generating an electric spark between the electrodes in the center of a sample cell. The duration of the discharge was 1.0 to 9.9 ms, and the ignition energy was typically about 0.1 to 1.0 J. The spread of the flame was visualized using schlieren photographs. A cylindrical container (inner diameter: 155 mm, length: 198 mm) equipped with two light transmission acrylic windows was used as the sample cell, and a xenon lamp was used as the light source. Schlieren images of the flame were recorded by a high-speed digital video camera at a frame rate of 600 fps and stored on PC.

The results are shown in Tables 59 to 66.

The results in Tables 59 to 62 indicate that the refrigerant has a WCF lower flammability in the following cases:

When then mass % of HFO-1132(E), HFO-1123, R1234yf, and R32 based on their sum in the mixed refrigerant of HFO-1132(E), HFO-1123, R1234yf, and R32 is respectively represented by x, y, z, and a, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is (100−a) mass % and a straight line connecting a point (0.0, 100.0−a, 0.0) and a point (0.0, 0.0, 100.0−a) is the base, if 0<a≤11.1, coordinates (x,y,z) in the ternary composition diagram are on or below a straight line GI that connects point G (0.026a 2 −1.7478a+72.0, −0.026a 2 +0.7478a+28.0, 0.0) and point I (0.026a 2 −1.7478a+72.0, 0.0, −0.026a 2 +0.7478a+28.0);

if 11.1<a≤18.2, coordinates (x,y,z) in the ternary composition diagram are on or below a straight line GI that connects point G (0.02a 2 −1.6013a+71.105, −0.02a 2 +0.6013a+28.895, 0.0) and point I (0.02a 2 −1.6013a+71.105, 0.0, −0.02a 2 +0.6013a+28.895); if 18.2<a≤26.7, coordinates (x,y,z) in the ternary composition diagram are on or below a straight line GI that connects point G (0.0135a 2 −1.4068a+69.727, −0.0135a 2 +0.4068a+30.273, 0.0) and point I (0.0135a 2 −1.4068a+69.727, 0.0, −0.0135a 2 +0.4068a+30.273); if 26.7<a≤36.7, coordinates (x,y,z) in the ternary composition diagram are on or below a straight line GI that connects point G (0.0111a 2 −1.3152a+68.986, −0.0111a 2 +0.3152a+31.014, 0.0) and point I (0.0111a 2 −1.3152a+68.986, 0.0, −0.0111a 2 +0.3152a+31.014); and if 36.7<a≤46.7, coordinates (x,y,z) in the ternary composition diagram are on or below a straight line GI that connects point G (0.0061a 2 −0.9918a+63.902, −0.0061a 2 −0.0082a+36.098, 0.0) and point I (0.0061a 2 −0.9918a+63.902, 0.0, −0.0061a 2 −0.0082a+36.098).

Three points corresponding to point G (Table 67) and point I (Table 68) were individually obtained in each of the following five ranges by calculation, and their approximate expressions were obtained.

The results in Tables 63 to 66 indicate that the refrigerant is determined to have a WCFF lower flammability, and the flammability classification according to the ASHRAE Standard is “2L (flammability)” in the following cases:

When the mass % of HFO-1132(E), HFO-1123, R1234yf, and R32 based on their sum in the mixed refrigerant of HFO-1132(E), HFO-1123, R1234yf, and R32 is respectively represented by x, y, z, and a, in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is (100−a) mass % and a straight line connecting a point (0.0, 100.0−a, 0.0) and a point (0.0, 0.0, 100.0−a) is the base, if 0<a≤11.1, coordinates (x,y,z) in the ternary composition diagram are on or below a straight line JK′ that connects point J (0.0049a 2 −0.9645a+47.1, −0.0049a 2 −0.0355a+52.9, 0.0) and point K′ (0.0514a 2 −2.4353a+61.7, −0.0323a 2 +0.4122a+5.9, −0.0191a 2 +1.0231a+32.4); if 11.1<a≤18.2, coordinates are on a straight line JK′ that connects point J (0.0243a 2 −1.4161a+49.725, −0.0243a 2 +0.4161a+50.275, 0.0) and point K′(0.034a 2 −2.1977a+61.187, −0.0236a 2 +0.34a+5.636, −0.0105a 2 +0.8577a+33.177); if 18.2<a≤26.7, coordinates are on or below a straight line JK′ that connects point J (0.0246a 2 −1.4476a+50.184, −0.0246a 2 +0.4476a+49.816, 0.0) and point K′ (0.0196a 2 −1.7863a+58.515, −0.0079a 2 −0.1136a+8.702, −0.0117a 2 +0.8999a+32.783); if 26.7<a≤36.7, coordinates are on or below a straight line JK′ that connects point J (0.0183a 2 −1.1399a+46.493, −0.0183a+0.1399a+53.507, 0.0) and point K′ (−0.0051a 2 +0.0929a+25.95, 0.0, 0.0051a 2 −1.0929a+74.05); and if 36.7<a≤46.7, coordinates are on or below a straight line JK′ that connects point J (−0.0134a 2 +1.0956a+7.13, 0.0134a 2 −2.0956a+92.87, 0.0) and point K′ (−0.1892a+29.443, 0.0, −0.8108a+70.557).

Actual points having a WCFF lower flammability form a curved line that connects point J and point K′ (on the straight line AB) and extends toward the HFO-1132(E) side. Accordingly, when coordinates are on or below the straight line JK′, WCFF lower flammability is achieved.

Three points corresponding to point J (Table 69) and point K′ (Table 70) were individually obtained in each of the following five ranges by calculation, and their approximate expressions were obtained.

FIGS. 2 to 12 show compositions whose R32 content a (mass %) is 0 mass %, 7.1 mass %, 11.1 mass %, 14.5 mass %, 18.2 mass %, 21.9 mass %, 26.7 mass %, 29.3 mass %, 36.7 mass %, 44.1 mass %, and 47.8 mass %, respectively.

Points A, B, C, and D′ were obtained in the following manner according to approximate calculation.

Point A is a point where the content of HFO-1123 is 0 mass %, and a refrigerating capacity ratio of 85% relative to that of R410A is achieved. Three points corresponding to point

A were obtained in each of the following five ranges by calculation, and their approximate expressions were obtained (Table 71).

Point B is a point where the content of HFO-1132(E) is 0 mass %, and a refrigerating capacity ratio of 85% relative to that of R410A is achieved.

Three points corresponding to point B were obtained in each of the following five ranges by calculation, and their approximate expressions were obtained (Table 72).

Point D′ is a point where the content of HFO-1132(E) is 0 mass %, and a COP ratio of 95.5% relative to that of R410A is achieved.

Three points corresponding to point D′ were obtained in each of the following by calculation, and their approximate expressions were obtained (Table 73).

Point C is a point where the content of R1234yf is 0 mass %, and a COP ratio of 95.5% relative to that of R410A is achieved.

Three points corresponding to point C were obtained in each of the following by calculation, and their approximate expressions were obtained (Table 74).

1 : Sample cell

2 : High-speed camera

3 : Xenon lamp

4 : Collimating lens

5 : Collimating lens

6 : Ring filter