Composition which contains refrigerant, refrigeration method, and refrigeration device

Abstract

Provided is a novel low-GWP mixed refrigerant.　Provided is a composition which contains a refrigerant, wherein the refrigerant contains CO2, trans-1,2-difluoroethylene (HFO-1132(E)), difluoromethane (R32), and 2,3,3,3-tetrafluoropropene (HFO-1234yf) at a specific blending ratio.

Description

Composition containing a refrigerant, refrigeration method, and refrigeration apparatus

[0001] This disclosure relates to a composition containing a refrigerant, a refrigeration method, and a refrigeration apparatus.

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

[0003] International Publication No. 2015 / 141678

[0004] This disclosure aims to provide a novel low-GWP mixed refrigerant.

[0005] Item 1. A composition containing a refrigerant, wherein the refrigerant comprises CO2 and trans-1,2-difluoroethylene (HFO-1132(E)), difluoromethane (R32), and 2,3,3,3-tetrafluoropropene (HFO-1234yf), and when the mass percentages based on the sum of CO2 and HFO-1132(E), R32, and R1234yf are a, x, y, and z respectively, in a three-component composition diagram where the sum of HFO-1132(E), R32, and R1234yf is 100-a mass%, when the coordinates (x,y,z) are 7.0 < a < 9.4, point C (54.0, -a+46.0, 0.0), point D (44.0, 0.0, -a+56.0), point E (0.0463a 2 -5.0509a+72.688, 0.0, -0.0463a 2 If the six points C, F, B, and A (0.0, -a+46.0, 0.0), D, E (0.0, -a+46.0, 0.0), and E (0.0607a) are enclosed by lines CD, DE, EF, FB, BA, and AC connecting these six points, or if the points lie on lines CD, DE, EF, and BA (excluding points C, F, B, and A), and 9.4 ≤ a ≤ 17.3, then the points C (54.0, -a+46.0, 0.0), D (44.0, 0.0, -a+56.0), and E (0.0607a) are within the range of the figure enclosed by lines CD, DE, EF, FB, BA, and AC connecting the six points C, F, B, and A (0.0, -a+46.0, 0.0), and E (0.0607a) are within the range of the figure enclosed by lines CD, DE, EF, BA, and AC connecting the six points C, F, B, and A (0.0, -a+46.0, 0.0), and E (0.0607a) are within the range of the figure enclosed by lines CD, DE, EF, BA, and AC connecting the six points C, F, B, B, and A (0.0, -a+46.0, 0.0), and E (0.0607a) are within the range of the figure enclosed by lines CD, DE, EF, BA, and AC connecting the six points C, B, F FB, BA, and A (0.0, -a+46.0, 0.0), and E (0.062 -5.3283a + 74.027, 0.0, -0.0607a 2 +4.3283a + 25.973), point F (0.0, 0.0012a 2 -2.9938a + 51.437, -0.0012a 2 +1.9938a + 48.563), point B (0.0, 51.6, -a + 48.4) and point A (-a + 48.2, 51.8, 0.0). The composition is within the range of the figure surrounded by the straight lines CD, DE, EF, FB, BA, and AC connecting these six points respectively, or on the straight lines CD, EF, and BA (excluding points C, point F, point B, and point A). Item 2. A composition containing a refrigerant, wherein the refrigerant contains CO2, as well as HFO - 1132(E), R32, and HFO - 1234yf. When the mass percentages of CO2, HFO - 1132(E), R32, and R1234yf based on their total sum are a, x, y, and z respectively, in a ternary composition diagram where the sum of HFO - 1132(E), R32, and R1234yf is 100% by mass, when 7.0 < a < 9.4, the coordinates (x, y, z) are as follows: point L (0.0185a 2 -0.2204a + 46.635, 0.0648a 2 -0.938a + 11.19, -0.0833a 2 +0.1583a + 42.175), point M (-0.0278a 2 +0.4972a + 35.581, -0.0556a 2 +0.9944a + 12.461, 0.0833a 2 -2.4917a + 51.958), point N (-0.0278a 2 +0.4972a + 30.681, 0.0278a 2 -0.4972a + 27.819, -a + 41.5), point O (-0.0278a 2 +0.4972a + 25.781, 0.0556a 2 -0.9944a + 43.139, -0.0278a 2 -0.5028a + 31.08), point P (0.0278a<00000-0.4972a+26.319, 51.7, -0.0278a 2 -0.5028a+21.981), Point B (0.0, 51.6, -a+48.4), Point F (0.0, -3.0a+51.6, 2.0a+48.4), Point E (0.0463a 2 -5.0509a+72.688, 0.0, -0.0463a 2 If point L (-0.0055a) is located within the area enclosed by the lines LM, MN, NO, OP, PB, BF, FE, ED, and DL connecting the nine points (+4.0509a + 27.312) and point D (44.0, 0.0, -a + 56.0), or on the lines LM, MN, NO, OP, PB, FE, and DL (excluding points B and F), and 9.4 ≤ a ≤ 17.3, then point L (-0.0055a) 2 +0.1856a+44.944, -0.017a 2 +0.3403a+6.4041, 0.0225a 2 -1.526a+48.652), point M (-0.0065a 2 +0.1093a+37.344, -0.0105a 2 +0.231a+15.661, 0.017a 2 -1.3403a+46.996), point N (-0.0129a 2 +0.2187a+31.987, -0.0041a 2 +0.1217a+24.817, 0.017a 2 -1.3403a+43.196), point O (-0.01a 2 +0.0908a+28.033, 38.7, 0.01a 2 -1.0908a+33.267), point P (-0.0086a 2 +0.0269a+24.607, 51.7, 0.0086a 2 -1.0269a+23.693), point B (0.0, 51.6, -a+48.4), point F (0.0, 0.0012a 2 -2.9938a+51.437, -0.0012a 2+1.9938a+48.563), point E (0.0607a 2 -5.3283a+74.027, 0.0, -0.0607a 2 A composition located within the area enclosed by the lines LM, MN, NO, OP, PB, BF, FE, ED, and DL connecting the nine points (+4.3283a+25.973) and point D (44.0, 0.0, -a+56.0), or on the lines LM, MN, NO, OP, PB, FE, and DL (excluding points B and F). Item 3. The composition according to item 1 or 2, wherein the total content of CO2 and the sum of HFO-1132(E), R32, and HFO-1234yf is 99.5% by mass or more relative to the total amount of refrigerants. Item 4. The composition according to any one of items 1 to 3, used as an R32 substitute refrigerant. Item 5. A refrigeration method comprising the step of operating a refrigeration cycle using the composition according to any one of items 1 to 4. Item 6. A refrigeration apparatus containing the composition according to any one of items 1 to 4 as a working fluid.

[0006] The refrigerant disclosed herein is low GWP.

[0007] This is a triangular diagram showing the composition of the refrigerant in this disclosure. This is a triangular diagram showing the composition of the refrigerant in this disclosure. This is a triangular diagram showing the composition of the refrigerant in this disclosure. This is a triangular diagram showing the composition of the refrigerant in this disclosure. This is a diagram showing the apparatus used in the combustion rate test of the example.

[0008] In order to solve the above problems, the inventors conducted diligent research and found that the various mixed refrigerants described below possess the above characteristics.

[0009] This disclosure is the result of further research based on the aforementioned findings. This disclosure includes the following embodiments. <Definition of Terms> In this specification, the term "refrigerant" includes at least compounds that have been assigned a refrigerant number (ASHRAE number) beginning with R, which indicates the type of refrigerant as defined by ISO 817 (International Organization for Standardization), and also includes compounds that have equivalent refrigerant properties even if they have not yet been assigned a refrigerant number. Refrigerants are broadly classified into "fluorocarbon compounds" and "non-fluorocarbon compounds" in terms of the structure of the compound. "Fluorocarbon compounds" include chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and hydrofluorocarbons (HFCs).

[0010] In this specification, the term "composition containing a refrigerant" includes at least (1) the refrigerant itself (including a mixture of refrigerants), (2) a composition further containing other components that can be used to obtain a working fluid for a refrigerator by mixing with at least refrigerant oil, and (3) a working fluid for a refrigerator containing refrigerant oil. In this specification, of these three embodiments, composition (2) is referred to as "refrigerant composition" to distinguish it from the refrigerant itself (including a mixture of refrigerants). Also, working fluid for a refrigerator (3) is referred to as "refrigerant oil-containing working fluid" to distinguish it from "refrigerant composition".

[0011] In this specification, when the term “substitute” is used in the context of “substituting” a first refrigerant with a second refrigerant, the first type means that equipment designed to operate using the first refrigerant can be operated under optimal conditions using the second refrigerant with only minor changes to components (at least one of the following: refrigerant oil, gaskets, packings, expansion valves, dryers, and other components) and equipment adjustments as needed. In other words, this type refers to operating the same equipment with a “substitute” refrigerant. The forms of “substitution” in this type may be, in order of increasing degree of change or adjustment required when replacing with the second refrigerant, “drop-in substitution,” “nealy drop-in substitution,” and “retrofit.”

[0012] A second type of "substitution" includes using equipment designed to operate with a second refrigerant, but for the same existing applications as the first refrigerant, by installing the second refrigerant. This type refers to providing the same application by "substituting" a refrigerant.

[0013] In this specification, the term "refrigeration unit" refers to any device that removes heat from an object or space to a temperature lower than the surrounding ambient air and maintains that low temperature. In other words, a refrigerator is a conversion device that obtains energy from an external source, performs work, and converts energy in order to transfer heat from a lower temperature to a higher temperature.

[0014] In this specification, "in-vehicle air conditioning equipment" refers to a type of refrigeration system used in automobiles such as gasoline cars, hybrid cars, electric cars, and hydrogen cars. In-vehicle air conditioning equipment refers to a refrigeration system consisting of a refrigeration cycle in which a liquid refrigerant undergoes heat exchange in an evaporator, the evaporated refrigerant gas is drawn in by a compressor, the adiabatically compressed refrigerant gas is cooled and liquefied in a condenser, and then passed through an expansion valve to undergo adiabatically expanded refrigerant before being supplied back to the evaporator as liquid refrigerant.

[0015] In this specification, "WCF low-flammability" of a refrigerant means that, according to the US ANSI / ASHRAE 34-2013 standard, the worst case of formulation for flammability (WCF) has a burning rate of 10 cm / s or less.

[0016] Furthermore, in this specification, when a refrigerant is described as ASHRAE low-flammability (WCF & WCFF low-flammability), it means that the WCF has a combustion rate of 10 cm / s or less, and the worst case of fractionation for flammability (WCFF), identified by performing storage, transport, and use leak tests based on ANSI / ASHRAE 34-2013 using WCF, has a combustion rate of 10 cm / s or less, and is judged to be in the "2L class" flammability category according to the US ANSI / ASHRAE 34-2013 standard.

[0017] Unless otherwise specified, the pressures described herein are in absolute pressure units.

[0018] 1. Refrigerants The refrigerants of this disclosure include CO2, as well as trans-1,2-difluoroethylene (HFO-1132(E)), difluoromethane (R32), and 2,3,3,3-tetrafluoropropene (HFO-1234yf).

[0019] The refrigerant in this disclosure is a low GWP mixed refrigerant.

[0020] In the refrigerant of this disclosure, when the mass percentages of CO2, HFO-1132(E), R32, and R1234yf based on their sum are a, x, y, and z, respectively, in a three-component composition diagram where the sum of HFO-1132(E), R32, and R1234yf is 100-a mass%, when the coordinates (x,y,z) satisfy the following requirements, no disproportionation reaction occurs at 3 MPa and 150°C, the refrigeration capacity ratio to R32 is 80% or more, and the GWP is 350 or less.

[0021] <Requirements> When 7.0 < a < 9.4, point C (54.0, -a + 46.0, 0.0), point D (44.0, 0.0, -a + 56.0), point E (0.0463a) 2 -5.0509a+72.688, 0.0, -0.0463a 2 The six points C (0.0, -a+46.0, 0.0), D (0.0, -a+48.0), and E (0.0607a) are enclosed by lines CD, DE, EF, FB, BA, and AC connecting these six points, or lie on lines CD, DE, EF, and BA (excluding points C, F, B, and A). When 9.4 ≤ a ≤ 17.3, the points C (54.0, -a+46.0, 0.0), D (44.0, 0.0, -a+56.0), and E (0.0607a) are also enclosed by lines CD, DE, EF, and BA. 2 -5.3283a+74.027, 0.0, -0.0607a 2 +4.3283a+25.973), point F (0.0, 0.0012a 2 -2.9938a+51.437, -0.0012a 2 The area is within the range of the figure enclosed by the lines CD, DE, EF, FB, BA, and AC that connect the six points (+1.9938a+48.563), point B (0.0, 51.6, -a+48.4), and point A (-a+48.2, 51.8, 0.0), or it lies on the lines CD, EF, and BA (excluding points C, F, B, and A).

[0022] In the refrigerant of this disclosure, when the mass percentages of CO2, HFO-1132(E), R32, and R1234yf based on their sum are a, x, y, and z, respectively, in a three-component composition diagram where the sum of HFO-1132(E), R32, and R1234yf is 100-a mass%, when the coordinates (x,y,z) satisfy the following requirements, no disproportionation reaction occurs at 3 MPa and 150°C, the refrigeration capacity ratio to R32 is 80% or more, the GWP is 350 or less, and it is ASHRAE slightly flammable.

[0023] <Requirements> When 7.0 < a < 9.4, point L (0.0185a) 2 -0.2204a+46.635, 0.0648a 2 -0.938a+11.19, -0.0833a 2 +0.1583a+42.175), point M (-0.0278a 2 +0.4972a+35.581, -0.0556a 2 +0.9944a+12.461, 0.0833a 2 -2.4917a+51.958), point N (-0.0278a 2 +0.4972a+30.681, 0.0278a 2 -0.4972a+27.819, -a+41.5), point O (-0.0278a 2 +0.4972a+25.781, 0.0556a 2 -0.9944a+43.139, -0.0278a 2 -0.5028a+31.08), point P (0.0278a 2 -0.4972a+26.319, 51.7, -0.0278a 2 -0.5028a+21.981), Point B (0.0, 51.6, -a+48.4), Point F (0.0, -3.0a+51.6, 2.0a+48.4), Point E (0.0463a 2 -5.0509a+72.688, 0.0, -0.0463a 2 If point L (-0.0055a) is located within the area enclosed by the lines LM, MN, NO, OP, PB, BF, FE, ED, and DL connecting the nine points (+4.0509a + 27.312) and point D (44.0, 0.0, -a + 56.0), or on the lines LM, MN, NO, OP, PB, FE, and DL (excluding points B and F), and 9.4 ≤ a ≤ 17.3, then point L (-0.0055a) 2 +0.1856a+44.944, -0.017a 2 +0.3403a+6.4041, 0.0225a 2 -1.526a+48.652), point M (-0.0065a 2+0.1093a+37.344, -0.0105a 2 +0.231a+15.661, 0.017a 2 -1.3403a+46.996), point N (-0.0129a 2 +0.2187a+31.987, -0.0041a 2 +0.1217a+24.817, 0.017a 2 -1.3403a+43.196), point O (-0.01a 2 +0.0908a+28.033, 38.7, 0.01a 2 -1.0908a+33.267), point P (-0.0086a 2 +0.0269a+24.607, 51.7, 0.0086a 2 -1.0269a+23.693), point B (0.0, 51.6, -a+48.4), point F (0.0, 0.0012a 2 -2.9938a+51.437, -0.0012a 2 +1.9938a+48.563), point E (0.0607a 2 -5.3283a+74.027, 0.0, -0.0607a 2 The figure is located within the area enclosed by the lines LM, MN, NO, OP, PB, BF, FE, ED, and DL that connect the nine points (+4.3283a+25.973) and point D (44.0, 0.0, -a+56.0), or on the lines LM, MN, NO, OP, PB, FE, and DL (excluding points B and F).

[0024] The refrigerant of this disclosure can suppress disproportionation reactions even when the refrigeration cycle locally reaches a refrigerant pressure of 3 MPa and a refrigerant temperature of 150°C.

[0025] The refrigerant in this disclosure contains CO2, to the extent that it does not impair the above-mentioned properties and effects. 2、 In addition to HFO-1132(E), R32, and HFO-1234yf, the refrigerants may also contain additional refrigerants. In this regard, in one embodiment, the refrigerants of the Disclosure may contain CO 2、Furthermore, it is preferable that the total of HFO-1132(E), R32, and HFO-1234yf be present in an amount of 99.5% by mass or more, more preferably 99.75% by mass or more, even more preferably 99.9% by mass or more, even more preferably 99.999% by mass or more, and most preferably 99.9999% by mass or more, relative to the total amount of refrigerant. The refrigerant of this disclosure is CO 2、 Furthermore, it may consist substantially of only HFO-1132(E), R32, and HFO-1234yf, in which case the refrigerant of this disclosure is CO 2、 The refrigerant may also consist only of HFO-1132(E), R32, and HFO-1234yf, as well as unavoidable impurities. The refrigerant of this disclosure is CO 2、 It may also consist solely of HFO-1132(E), R32, and HFO-1234yf.

[0026] The additional refrigerant is not particularly limited and can be broadly selected. The mixed refrigerant may contain one type of additional refrigerant alone, or it may contain two or more types.

[0027] Additional refrigerants include acetylene, HFO-1132a, HFO-1141, HFO-1123, HFC-143a, HFC-134a, Z-HFO-1132, HFO-1243zf, HFC-245cb, HCFC-1122, HCFC-124, CFC-1113, and 3,3,3-trifluoropropyne.

[0028] The compositions of the present disclosure also include compositions comprising a refrigerant, wherein the refrigerant comprises: HFO-1132(E), R32 and R1234yf; and at least one additional refrigerant selected from the group consisting of acetylene, HFO-1132a, HFO-1141, HFO-1123, HFC-143a, HFC-134a, Z-HFO-1132, HFO-1243zf, HFC-245cb, HCFC-1122, HCFC-124, CFC-1113, HFC-152a, HFC-161 and 3,3,3-trifluoropropyne.

[0029] 2. Refrigerant Compositions The refrigerant compositions of the present disclosure may contain at least the refrigerant of the present disclosure and may be used for the same purposes as the refrigerant of the present disclosure. Furthermore, the refrigerant compositions of the present disclosure may be used to obtain a working fluid for a refrigerator by further mixing them with at least refrigerant oil.

[0030] The refrigerant compositions of this disclosure contain, in addition to the refrigerant of this disclosure, at least one other component. The refrigerant compositions of this disclosure may optionally contain at least one of the following other components. As described above, when the refrigerant compositions of this disclosure are used as working fluids in a refrigerator, they are usually used in mixture with at least refrigerant oil. Therefore, the refrigerant compositions of this disclosure preferably contain substantially no refrigerant oil. Specifically, the refrigerant composition of this disclosure preferably contains 1% by mass or less, and more preferably 0.1% by mass or less, of refrigerant oil relative to the total refrigerant composition.

[0031] 2.1 Water The refrigerant composition disclosed herein may contain trace amounts of water. Preferably, the water content in the refrigerant composition is 0.1% by mass or less relative to the total refrigerant. The inclusion of trace amounts of water in the refrigerant composition stabilizes the intramolecular double bonds of unsaturated fluorocarbon compounds that may be contained in the refrigerant, and also makes oxidation of unsaturated fluorocarbon compounds less likely, thereby improving the stability of the refrigerant composition.

[0032] The compositions of this disclosure also include compositions comprising a refrigerant, wherein the refrigerant comprises HFO-1132(E), R32, and R1234yf, and 0.1% or less of water.

[0033] 2.2 Tracer Tracers are added to the refrigerant composition of the Disclosure in a detectable concentration so that any changes to the refrigerant composition of the Disclosure can be tracked if the composition is diluted, contaminated, or otherwise altered.

[0034] The refrigerant composition of this disclosure may contain one tracer alone or two or more tracers.

[0035] The tracer is not particularly limited and can be appropriately selected from among commonly used tracers.

[0036] Examples of tracers include hydrofluorocarbons, hydrochlorofluorocarbons, chlorofluorocarbons, hydrochlorocarbons, fluorocarbons, deuterated hydrocarbons, deuterated hydrofluorocarbons, perfluorocarbons, fluoroethers, brominated compounds, iodized compounds, alcohols, aldehydes, ketones, and nitrous oxide (N2O). Hydrofluorocarbons, hydrochlorofluorocarbons, chlorofluorocarbons, hydrochlorocarbons, fluorocarbons, and fluoroethers are particularly preferred as tracers.

[0037] The following compounds are preferred as tracers. FC-14 (tetrafluoromethane, CF4) HCC-40 (chloromethane, 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-143a (1,1,1-trifluoroethane, CF3CH3) HFC-143 (1,1,2-trifluoroethane, CHF2CH2F) HFC-152a (1,1-difluoroethane, CHF2CH3) 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) CFC-1113 (chlorotrifluoroethylene, CF2=CClF) 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)

[0038] The refrigerant composition of this disclosure may contain tracers in total at about 10 parts by weight per million (ppm) or more relative to the entire refrigerant composition. Alternatively, the refrigerant composition of this disclosure may contain tracers in total at about 1000 ppm or less relative to the entire refrigerant composition. The refrigerant composition of this disclosure may preferably contain tracers in total at about 30 ppm or more, more preferably at about 50 ppm or more, relative to the entire refrigerant composition. The refrigerant composition of this disclosure may preferably contain tracers in total at about 500 ppm or less, and may contain about 300 ppm or less, relative to the entire refrigerant composition.

[0039] 2.3 Ultraviolet fluorescent dyes The refrigerant composition of this disclosure may contain one ultraviolet fluorescent dye alone or two or more ultraviolet fluorescent dyes.

[0040] The ultraviolet fluorescent dye is not particularly limited and can be appropriately selected from commonly used ultraviolet fluorescent dyes.

[0041] Examples of ultraviolet fluorescent dyes include naphthalimide, coumarin, anthracene, phenanthrene, xanthene, thioxanthene, naphthoxanthene, and fluorescein, as well as their derivatives. Naphthalimide and coumarin, or either or both, are particularly preferred as ultraviolet fluorescent dyes.

[0042] 2.4 Stabilizers The refrigerant compositions of this disclosure may contain one stabilizer alone or two or more stabilizers.

[0043] The stabilizer is not particularly limited and can be appropriately selected from among commonly used stabilizers.

[0044] Examples of stabilizers include nitro compounds, ethers, and amines.

[0045] Examples of nitro compounds include aliphatic nitro compounds such as nitromethane and nitroethane, and aromatic nitro compounds such as nitrobenzene and nitrostyrene.

[0046] Examples of ethers include 1,4-dioxane.

[0047] Examples of amines include 2,2,3,3,3-pentafluoropropylamine and diphenylamine.

[0048] Other examples include butylhydroxyxylene and benzotriazole.

[0049] The stabilizer content is preferably 0.01% by mass or more, and more preferably 0.05% by mass or more, relative to the total refrigerant. The stabilizer content is preferably 5% by mass or less, and more preferably 2% by mass or less, relative to the total refrigerant.

[0050] 2.5 Polymerization Inhibitors The refrigerant compositions of this disclosure may contain one polymerization inhibitor alone or two or more polymerization inhibitors.

[0051] The polymerization inhibitor is not particularly limited and can be appropriately selected from among commonly used polymerization inhibitors.

[0052] 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.

[0053] The polymerization inhibitor content is preferably 0.01% by mass or more, and more preferably 0.05% by mass or more, relative to the total refrigerant. The polymerization inhibitor content is preferably 5% by mass or less, and more preferably 2% by mass or less, relative to the total refrigerant.

[0054] 3. Refrigerant Oil-Containing Working Fluid The refrigerant oil-containing working fluid of this disclosure contains at least the refrigerant or refrigerant composition of this disclosure and refrigerant oil, and is used as a working fluid in a refrigerator. Specifically, the refrigerant oil-containing working fluid of this disclosure is obtained by mixing refrigerant oil used in the compressor of a refrigerator with the refrigerant or refrigerant composition. The refrigerant oil-containing working fluid generally contains 10% by mass or more of refrigerant oil. The refrigerant oil-containing working fluid generally contains 50% by mass or less of refrigerant oil.

[0055] 3.1 Refrigerant Oil The composition of this disclosure may contain one type of refrigerant oil alone, or it may contain two or more types.

[0056] The refrigerating oil is not particularly limited and can be appropriately selected from commonly used refrigerating oils. In that case, a refrigerating oil that is superior in terms of compatibility with the mixture and its ability to improve the stability of the mixture can be appropriately selected as needed.

[0057] As the base oil for the refrigeration oil, at least one selected from the group consisting of polyalkylene glycol (PAG), polyol ester (POE), and polyvinyl ether (PVE) is preferred.

[0058] Refrigerant oil may contain additives in addition to the base oil. The additives may be at least one selected from the group consisting of antioxidants, extreme pressure agents, acid scavengers, oxygen scavengers, copper deactivators, rust inhibitors, oiliness agents, and defoaming agents.

[0059] For refrigeration oil, a kinematic viscosity of 5 cSt or higher at 40°C is preferable from a lubrication standpoint. Furthermore, for refrigeration oil, a kinematic viscosity of 400 cSt or lower at 40°C is preferable from a lubrication standpoint.

[0060] The refrigerant oil-containing working fluid of this disclosure may optionally further contain at least one additive. Examples of additives include the following compatibilizers.

[0061] 3.2 Compatibilizers The refrigeration oil-containing working fluid of this disclosure may contain one type of compatibilizer alone, or it may contain two or more types of compatibilizers.

[0062] The compatibilizer is not particularly limited and can be appropriately selected from among commonly used compatibilizers.

[0063] Examples of compatibilizers include polyoxyalkylene glycol ethers, amides, nitriles, ketones, chlorocarbons, esters, lactones, aryl ethers, fluoroethers, and 1,1,1-trifluoroalkanes. Polyoxyalkylene glycol ethers are particularly preferred as compatibilizers.

[0064] 4. Method of operating the refrigerator The method of operating the refrigerator of this disclosure is a method of operating the refrigerator using the refrigerant of this disclosure.

[0065] Specifically, the method for operating the refrigerator of this disclosure includes a step of circulating the refrigerant of this disclosure in the refrigerator.

[0066] 5. Method for suppressing disproportionation reaction The method for suppressing disproportionation reaction of HFO-1132(E) according to the present disclosure is a method for suppressing disproportionation reaction of HFO-1132(E) that includes the step of operating a refrigeration cycle using the refrigerant according to the present disclosure.

[0067] In the method for suppressing disproportionation reactions of the present disclosure, the effect is obtained that the disproportionation reaction of HFO-1132(E) does not occur even when the refrigerant pressure is 3.0 MPa and the refrigerant temperature is 150°C.

[0068] The method for suppressing disproportionation reactions disclosed herein makes it possible to suppress disproportionation reactions and operate the refrigeration cycle even in refrigerators that do not have means for suppressing disproportionation reactions.

[0069] 6. Use for suppressing disproportionation reactions The use of the present disclosure is for suppressing the disproportionation reaction of CO2, R32, and HFO-1234yf of HFO-1132(E), which is achieved by mixing CO2, HFO-1132(E), R32, and HFO-1234yf in the refrigerant mixing ratio of the present disclosure.

[0070] In its use for suppressing disproportionation reactions, the HFO-1132(E) disproportionation reaction is particularly effective when the refrigerant pressure is 3.0 MPa and the refrigerant temperature is 150°C.

[0071] Although embodiments have been described above, it should be understood that various modifications to the form and details are possible without departing from the spirit and scope of the claims.

[0072] The following provides further details with reference to examples. However, this disclosure is not limited to these examples.

[0073] Mixed refrigerants were prepared by mixing CO2, HFO-1132(E), R32, and HFO-1234yf in the mass percentages shown in Table 1, based on their sum.

[0074] For each of these mixed refrigerants, the presence or absence of disproportionation reactions was investigated under the following test methods and conditions. Test Method The refrigerant composition to be tested was transferred and filled into a test container, heated to 150°C, and then 30 J of energy was applied to the refrigerant composition by applying voltage to a Pt wire inside the container to melt it. The presence or absence of disproportionation reactions was determined by the rapid increase in pressure and temperature inside the apparatus. Test Conditions Test container: 38 cc SUS container Test temperature: 150°C Pressure: 3 MPa Judgment Criteria "No explosion": The temperature or pressure after melting the Pt wire was less than twice the original temperature, and no rapid disproportionation reaction occurred. "Explosion": The temperature or pressure after melting the Pt wire reached more than twice the original temperature, and a rapid disproportionation reaction occurred.

[0075]

[0076]

[0077]

[0078]

[0079] From the results in Tables 1 to 4, it can be seen that the refrigerant of this disclosure does not cause disproportionation within the region shown in the triangular diagrams in Figures 1 to 5.

[0080] Furthermore, the combustion rate test was performed using the apparatus shown in Figure 6, as follows. First, the mixed refrigerant used was made 99.5% or higher in purity and degassed by repeating a cycle of freezing, pumping, and thawing until no trace of air was visible on the vacuum gauge. The combustion rate was measured using the closed method. The initial temperature was the ambient temperature. Ignition was performed by generating an electrical spark between electrodes at the center of the sample cell. The discharge duration was set to 1.0 to 9.9 ms, and the ignition energy was typically about 0.1 to 1.0 J. The flame propagation state was visualized using the Schlieren method. A cylindrical container (inner diameter: 155 mm, length: 198 mm) with two light-transmitting acrylic windows was used as the sample cell, and a xenon lamp was used as the light source. The Schlieren image of the flame was recorded with a high-speed digital video camera at a framing speed of 600 fps and saved to a PC. The combustion rate (Su (cm / s)) is expressed as the volume of unburned gas consumed per unit time by a unit area of ​​the flame surface, and is calculated using the following formula: Su = Sb * ρu / ρb Sb: flame propagation speed (cm / s) ρu: adiabatic flame temperature (unburned) ρb: adiabatic flame temperature (burned) Here, Sb was obtained from the Schlieren video image, ρu was the measured temperature, and ρb was calculated from the heat of combustion and specific heat at constant pressure of the combustion gas. The results are shown in Tables 5 to 9.

[0081]

[0082]

[0083]

[0084]

[0085]

[0086] From the results in Tables 5 to 9, it can be seen that the refrigerants of this disclosure are non-combustible in the region shown in the triangular diagrams in Figures 1 to 5, either as WCF or WCFF.

[0087] The GWP of HFO-1132(E) was set to 1, and the GWP of R32 and HFO-1234yf was evaluated based on the values ​​from the IPCC (Intergovernmental Panel on Climate Change) Fourth Assessment Report. Furthermore, the COP, refrigeration capacity, discharge temperature, and boiling point of the mixed refrigerant were determined by performing theoretical calculations of the refrigeration cycle under the following conditions using the National Institute of Science and Technology (NIST) Reference Fluid Thermodynamic and Transport Properties Database (Refprop 9.0). Note that the physical property data for HFO-1132(E) was obtained from measured values. Evaporation temperature: 5°C, Condensation temperature: 45°C, Superheating temperature: 5K, Supercooling temperature: 5K, Compressor efficiency: 70%

[0088] In the table below, "COP ratio" and "refrigeration capacity ratio" refer to the percentage relative to R32.

[0089] The coefficient of performance (COP) was calculated using the following formula: COP = (refrigeration capacity) / power consumption

[0090]

[0091]

[0092]

[0093]

[0094]

[0095] The coordinates on each line segment EF were determined using the least squares method as follows.

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105]

[0106]

[0107]

[0108]

[0109] From the above results, it can be seen that, in the refrigerant of this disclosure, when the mass percentages based on the sum of CO2, HFO-1132(E), R32, and R1234yf are a, x, y, and z, respectively, in a three-component composition diagram where the sum of HFO-1132(E), R32, and R1234yf is 100-a mass%, when the coordinates (x,y,z) satisfy the following requirements, no disproportionation reaction occurs at 3 MPa and 150°C, the refrigeration capacity ratio to R32 is 80% or more, and the GWP is 350 or less.

[0110] <Requirements> When 7.0 < a < 9.4, point C (54.0, -a + 46.0, 0.0), point D (44.0, 0.0, -a + 56.0), point E (0.0463a) 2 -5.0509a+72.688, 0.0, -0.0463a 2Points C (54.0, -a + 46.0, 0.0), point D (44.0, 0.0, -a + 56.0), point E (0.0607a 2 -5.3283a + 74.027, 0.0, -0.0607a 2 +4.3283a + 25.973), point F (0.0, 0.0012a 2 -2.9938a + 51.437, -0.0012a 2 +1.9938a + 48.563), point B (0.0, 51.6, -a + 48.4) and point A (-a + 48.2, 51.8, 0.0), within the figure enclosed by the straight lines CD, DE, EF, FB, BA and AC connecting these six points respectively, or on the straight lines CD, EF, and BA (excluding points C, point F, point B and point A).

[0111] From the above results, in the refrigerant of the present disclosure, when the mass percentages of CO2, HFO - 1132(E), R32 and R1234yf based on their total sum are a, x, y and z respectively, in the ternary composition diagram where the total sum of HFO - 1132(E), R32 and R1234yf is 100 - a mass%, when the coordinates (x, y, z) satisfy the following requirements, it can be seen that no disproportionation reaction occurs at 3 MPa and 150 °C, the refrigerating capacity ratio to R32 is 80% or more, the GWP is 350 or less, and it is ASHRAE mildly flammable.

[0112] <Requirements> When 7.0 < a < 9.4, point L (0.0185a 2 -0.2204a + 46.635, 0.0648a 2 -0.938a + 11.19, -0.0833a 2(+0.1583a + 42.175), point M (-0.0278a 2 (+0.4972a + 35.581, -0.0556a 2 (+0.9944a + 12.461, 0.0833a 2 (-2.4917a + 51.958), point N (-0.0278a 2 (+0.4972a + 30.681, 0.0278a 2 (-0.4972a + 27.819, -a + 41.5), point O (-0.0278a 2 (+0.4972a + 25.781, 0.0556a 2 (-0.9944a + 43.139, -0.0278a 2 (-0.5028a + 31.08), point P (0.0278a 2 (-0.4972a + 26.319, 51.7, -0.0278a 2 (-0.5028a + 21.981), point B (0.0, 51.6, -a + 48.4), point F (0.0, -3.0a + 51.6, 2.0a + 48.4), point E (0.0463a 2 (-5.0509a + 72.688, 0.0, -0.0463a 2 (+4.0509a + 27.312) and the straight lines LM, MN, NO, OP, PB, BF, FE, ED, and DL connecting the nine points of point D (44.0, 0.0, -a + 56.0) respectively are within the range of the figure surrounded by them or on the straight lines LM, MN, NO, OP, PB, FE, and DL (excluding point B and point F). When 9.4 ≦ a ≦ 17.3, point L (-0.0055a 2 (+0.1856a + 44.944, -0.017a 2 (+0.3403a + 6.4041, 0.0225a 2 [[ID=​​​​​​​+0.2187a+31.987, -0.0041a 2 +0.1217a+24.817, 0.017a 2 -1.3403a+43.196), point O (-0.01a 2 +0.0908a+28.033, 38.7, 0.01a 2 -1.0908a+33.267), point P (-0.0086a 2 +0.0269a+24.607, 51.7, 0.0086a 2 -1.0269a+23.693), point B (0.0, 51.6, -a+48.4), point F (0.0, 0.0012a 2 -2.9938a+51.437, -0.0012a 2 +1.9938a+48.563), point E (0.0607a 2 -5.3283a+74.027, 0.0, -0.0607a 2 The figure is enclosed by the lines LM, MN, NO, OP, PB, BF, FE, ED, and DL that connect the nine points (+4.3283a+25.973) and point D (44.0, 0.0, -a+56.0), respectively, or it lies on the lines LM, MN, NO, OP, PB, FE, and DL (excluding points B and F).

[0113] 1: Sample cell 2: High-speed camera 3: Xenon lamp 4: Collimating lens 5: Collimating lens 6: Ring filter

Claims

1. A composition containing a refrigerant, wherein the refrigerant comprises CO2, and trans-1,2-difluoroethylene (HFO-1132(E)), difluoromethane (R32), and 2,3,3,3-tetrafluoropropene (HFO-1234yf), and when the mass percentages based on the sum of CO2, HFO-1132(E), R32, and R1234yf are a, x, y, and z respectively, in a three-component composition diagram where the sum of HFO-1132(E), R32, and R1234yf is 100-a mass%, when the coordinates (x,y,z) are 7.0 < a < 9.4, point C (54.0, -a+46.0, 0.0), point D (44.0, 0.0, -a+56.0), point E (0.0463a). 2 -5.0509a+72.688, 0.0, -0.0463a 2 If the six points C, F, B, and A (0.0, -a+46.0, 0.0), point C (54.0, -a+46.0, 0.0), point D (44.0, 0.0, -a+56.0), and point E (0.0607a) are within the range of the figure enclosed by the lines CD, DE, EF, FB, BA, and AC that connect the six points C, F, B, and A (0.0, -a+48.2, 51.8, 0.0), or lie on the lines CD, DE, EF, and BA (excluding points C, F, B, and A), and 9.4 ≤ a ≤ 17.3, then point C (54.0, -a+46.0, 0.0), point D (44.0, 0.0, -a+56.0), and point E (0.0607a) are within the range of the figure enclosed by the lines CD, DE, EF, FB, BA, and AC that connect the six points C, F, B, and A (0.0, -a+46.0, 0.0), and point E (0.0607a) are within the range of the figure enclosed by the lines CD, DE, EF, BA, and AC that connect the six points C, F, B B, F, B, FB, BA, and AC (0.0, -a+46.0, 0.0 2 -5.3283a+74.027, 0.0, -0.0607a 2 +4.3283a+25.973), point F (0.0, 0.0012a 2 -2.9938a+51.437, -0.0012a 2 A composition that lies within the area of ​​a figure enclosed by the lines CD, DE, EF, FB, BA, and AC connecting the six points B (0.0, 51.6, -a+48.4) and A (-a+48.2, 51.8, 0.0), or on the lines CD, EF, and BA (excluding points C, F, B, and A).

2. A composition containing a refrigerant, wherein the refrigerant contains CO2, HFO-1132(E), R32 and HFO-1234yf. When the mass percentages of CO2, HFO-1132(E), R32 and R1234yf based on their total sum are a, x, y and z respectively, in a ternary composition diagram where the total sum of HFO-1132(E), R32 and R1234yf is 100% by mass, when 7.0 < a < 9.4, the coordinates (x, y, z) are: point L (0.0185a 2 -0.2204a + 46.635, 0.0648a 2 -0.938a + 11.19, -0.0833a 2 +0.1583a + 42.175), point M (-0.0278a 2 +0.4972a + 35.581, -0.0556a 2 +0.9944a + 12.461, 0.0833a 2 -2.4917a + 51.958), point N (-0.0278a 2 +0.4972a + 30.681, 0.0278a 2 -0.4972a + 27.819, -a + 41.5), point O (-0.0278a 2 +0.4972a + 25.781, 0.0556a 2 -0.9944a + 43.139, -0.0278a 2 -0.5028a + 31.08), point P (0.0278a 2 -0.4972a + 26.319, 51.7, -0.0278a 2 -0.5028a + 21.981), point B (0.0, 51.6, -a + 48.4), point F (0.0, -3.0a + 51.6, 2.0a + 48.4), point E (0.0463a 2 -5.0509a + 72.688, 0.0, -0.0463a 2 If point L (-0.0055a) is located within the area enclosed by the lines LM, MN, NO, OP, PB, BF, FE, ED, and DL connecting the nine points (+4.0509a + 27.312) and point D (44.0, 0.0, -a + 56.0), or on the lines LM, MN, NO, OP, PB, FE, and DL (excluding points B and F), and 9.4 ≤ a ≤ 17.3, then point L (-0.0055a) 2 +0.1856a+44.944, -0.017a 2 +0.3403a+6.4041, 0.0225a 2 -1.526a+48.652), point M (-0.0065a 2 +0.1093a+37.344, -0.0105a 2 +0.231a+15.661, 0.017a 2 -1.3403a+46.996), point N (-0.0129a 2 +0.2187a+31.987, -0.0041a 2 +0.1217a+24.817, 0.017a 2 -1.3403a+43.196), point O (-0.01a 2 +0.0908a+28.033, 38.7, 0.01a 2 -1.0908a+33.267), point P (-0.0086a 2 +0.0269a+24.607, 51.7, 0.0086a 2 -1.0269a+23.693), point B (0.0, 51.6, -a+48.4), point F (0.0, 0.0012a 2 -2.9938a+51.437, -0.0012a 2 +1.9938a+48.563), point E (0.0607a 2 -5.3283a+74.027, 0.0, -0.0607a 2 A composition located within the area of ​​a figure enclosed by the lines LM, MN, NO, OP, PB, BF, FE, ED, and DL that connect the nine points (+4.3283a+25.973) and point D (44.0, 0.0, -a+56.0), or on the lines LM, MN, NO, OP, PB, FE, and DL (excluding points B and F).

3. The composition according to claim 1 or 2, wherein the total content of CO2 and HFO-1132(E), R32, and HFO-1234yf relative to the total amount of the refrigerants is 99.5% by mass or more.

4. A composition according to any one of claims 1 to 3, which is used as an R32 substitute refrigerant.

5. A refrigeration method comprising the step of operating a refrigeration cycle using the composition described in any one of claims 1 to 4.

6. A refrigeration apparatus comprising the composition described in any one of claims 1 to 4 as a working fluid.

Images