Working medium for heat cycle and composition for heat cycle system

Abstract

A working medium for a heat cycle, which contains trifluoroethylene, 1, 1-difluoroethane, and (E)-1, 3, 3, 3-tetrafluoropropene.

Description

Technical Field

[0001] The present disclosure relates to a working medium for a heat cycle and a composition for a heat cycle system. Background Art

[0002] In the present disclosure, for a halogenated hydrocarbon, the abbreviation of the compound is added in parentheses after the compound name, and the abbreviation may also be used to replace the compound name as needed.

[0003] Conventionally, as working media for heat cycle systems such as refrigerants for refrigerators, refrigerants for air-conditioning equipment, working media for power generation systems (such as waste heat recovery power generation), working media for latent heat transfer devices (such as heat pipes), and secondary cooling media, chlorofluorocarbons (CFCs) such as chlorotrifluoromethane and dichlorodifluoromethane, and hydrochlorofluorocarbons (HCFCs) such as chlorodifluoromethane have been used. However, CFCs and HCFCs have been pointed out to have an impact on the ozone layer in the stratosphere and have now become regulated substances.

[0004] For this reason, as working media for heat cycle systems, hydrofluorocarbons (HFCs) such as difluoromethane (HFC-32), tetrafluoroethane, and pentafluoroethane (HFC-125) that have little impact on the ozone layer are now used to replace CFCs and HCHCs. For example, R410A (an azeotropic-like mixed refrigerant with a mass ratio of HFC-32 to HFC-125 of 1:1) and the like have been widely used refrigerants. However, HFCs have been pointed out to potentially cause global warming.

[0005] R410A has been widely used in so-called commercial air conditioners or air-conditioning equipment such as household air conditioners due to its strong refrigeration capacity. However, the global warming potential (GWP) of R410A is as high as 2256. Therefore, it is necessary to develop a working medium with a low GWP. In this case, it is required to develop a working medium on the premise of only replacing R410A and continuing to use the equipment used so far as it is.

[0006] Recently, hydrofluoroolefins (HFOs), that is, HFCs having a carbon-carbon double bond, have been highly anticipated as working media that have little impact on the ozone layer and little impact on global warming because the carbon-carbon double bond is easily decomposed by OH radicals in the atmosphere. In the present disclosure, unless otherwise specified, saturated HFCs are referred to as HFCs and are used separately from HFOs.

[0007] Among HFOs, as a widely used working medium, for example, 2,3,3,3-tetrafluoropropene (HFO-1234yf) can be cited. The GWP of HFO-1234yf is low, but it is difficult to obtain high cycle performance. Therefore, among HFOs, it is required to develop a working medium with a low GWP and improved cycle performance compared to HFO-1234yf.

[0008] As a working medium using HFO, for example, Patent Document 1 discloses a technology of a working medium using trifluoroethylene (HFO-1123) which has a low GWP and excellent cycle performance. Prior Art Documents Patent Documents

[0009] Patent Document 1: International Publication No. 2015 / 125880 Summary of the Invention Technical Problem to be Solved by the Invention

[0010] An object of one aspect of the present disclosure is to provide a working medium for a heat cycle which has excellent cycle performance, has a small impact on global warming, and has a low combustion heat, and a composition for a heat cycle system made therefrom. Technical Solution for Solving the Technical Problem

[0011] The present disclosure includes the following aspects. <1> A working medium for a heat cycle, which contains trifluoroethylene, 1,1-difluoroethane, and (E)-1,3,3,3-tetrafluoropropene. <2> The working medium for a heat cycle according to <1>, wherein, when the content ratio of 1,1-difluoroethane is set to Y mass% and the content ratio of (E)-1,3,3,3-tetrafluoropropene is set to Z mass% with respect to the total of trifluoroethylene, 1,1-difluoroethane, and (E)-1,3,3,3-tetrafluoropropene, the following formulas (1) and (2) are satisfied: Formula (1): 2.0 ≤ Y ≤ 18.34 Formula (2): Z ≤ -0.01611×Y 2 -0.36606×Y + 17.14. <3> The working medium for a heat cycle according to <2>, wherein the combustion heat of the working medium for a heat cycle is 12.000 MJ / kg or less. <4> The working medium for a heat cycle according to <2> or <3>, wherein the global warming potential value of the working medium for a heat cycle is 45 or less. <5> The working medium for a heat cycle according to <1>, wherein, when the content ratio of 1,1-difluoroethane is set to Y mass% and the content ratio of (E)-1,3,3,3-tetrafluoropropene is set to Z mass% with respect to the total of trifluoroethylene, 1,1-difluoroethane, and (E)-1,3,3,3-tetrafluoropropene, the following formulas (3) and (4) are satisfied: Formula (3): 2.0 ≤ Y ≤ 76.25 Formula (4): Z ≥ 0.00279×Y 2 -1.25979×Y + 84.84 <6>The working medium for thermal cycle as described in <5>, wherein the combustion heat of the working medium for thermal cycle is 15,300 MJ / kg or less. <7>The working medium for thermal cycle as described in <5> or <6>, wherein the global warming potential value of the working medium for thermal cycle is 130 or less. <8>A composition for a thermal cycle system, which contains the working medium for thermal cycle according to any one of <1> to <7>. Advantages of the Invention

[0012] According to one aspect of the present disclosure, it is possible to provide a working medium for thermal cycle having excellent cycle performance, small impact on global warming, and low combustion heat, and a composition for a thermal cycle system made therefrom. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 Shown is a schematic structural diagram of a refrigeration cycle system as an example of a thermal cycle system according to one embodiment of the present disclosure. Figure 2 Shown is Figure 1 a cycle diagram in which the state change of the working medium for thermal cycle in the refrigeration cycle system is depicted by a pressure-enthalpy diagram. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0014] Hereinafter, embodiments of the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments. In the following embodiments, its constituent elements (including element steps, etc.) are not essential unless otherwise specifically stated. The same applies to numerical values and their ranges, which do not limit the present disclosure.

[0015] In the present disclosure, the numerical range indicated by "~" includes the numerical values described before and after "~" as the minimum value and the maximum value, respectively. In the present disclosure, each component may contain a plurality of corresponding substances. When there are a plurality of substances corresponding to each component in the composition, unless otherwise specifically stated, the proportion of each component refers to the total proportion of the plurality of substances present in the composition.

[0016] In the present disclosure, when describing an embodiment with reference to the drawings, the structure of the embodiment is not limited to the structure shown in the drawings. In addition, the dimensions of the components in each drawing are schematic, and the relative relationship of the dimensions between the components is not limited thereto. In the present disclosure, the combination of two or more preferred embodiments is a more preferred embodiment.

[0017] In the present disclosure, the GWP of the working medium is the 100-year value in the 6th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). In addition, the GWP of the mixture is based on the weighted average of the constituent masses.

[0018] In the present disclosure, the combustion heat of the working medium refers to the value obtained by converting the combustion heat value obtained when 1 mol of the working medium is completely burned with oxygen in a stoichiometric ratio into the combustion heat value per 1 kg of the working medium, and is a theoretical value calculated based on the following assumptions. It is assumed that the compounds in the formation system and the reaction system are gases. The compounds in the formation system, i.e., the combustion products, are HF(g), CO 2 (g), COF 2 (g), and H 2 O(g). When calculating the combustion heat of the working medium, each compound contained in the working medium is decomposed into the atoms constituting each compound, and a hypothetical substance containing each atom is set considering the molar ratio in the working medium. The combustion heat is calculated using the combustion reaction formula of this hypothetical substance. In addition, C q H r F s corresponds to the hypothetical substance. For example, the combustion reaction formula is defined by the magnitudes of the number of H atoms (r) and the number of F atoms (s) in the substance. When the number of H atoms (r) ≥ the number of F atoms (s), the combustion reaction formula uses the following formula.

[0019] [Mathematical formula 1]

[0020] When the number of H atoms (r) < the number of F atoms (s), the combustion reaction formula uses the following formula.

[0021] [Mathematical formula 2]

[0022] [Working medium for cycle] The working medium for heat cycle in one embodiment of the present disclosure includes trifluoroethylene (HFO-1123), 1,1-difluoroethane (HFC-152a), and (E)-1,3,3,3-tetrafluoropropene (HFO-1234ze(E)). Hereinafter, the working medium for heat cycle will also be simply referred to as the "working medium". By making the working medium of this embodiment include HFO-1123, HFC-152a, and HFO-1234ze(E), it is possible to have excellent cycle performance, a small impact on global warming, and a low combustion heat.

[0023] As described above, R410A and HFO-1234yf are widely used as working media for thermal cycles. However, although R410A has high cycle performance, it has a high GWP. Therefore, a working medium with high cycle performance and low GWP is required as its substitute. In addition, although HFO-1234yf has a low GWP, its cycle performance is low. Therefore, a working medium with low GWP and high cycle performance is required as its substitute.

[0024] Cycle performance is a necessary performance when using a working medium in a thermal cycle system, and is evaluated by the coefficient of performance and the capacity per unit volume. When the thermal cycle system is a refrigeration cycle system, the capacity is the refrigeration capacity, which is the output power of the refrigeration cycle system. The coefficient of performance is the value obtained by dividing the output power (kW) by the driving power (kW) consumed to obtain the output power (kW), which is equivalent to the energy consumption efficiency. That is, the coefficient of performance is the capacity per 1 kW of power consumption. The higher the value of the coefficient of performance, the higher the output power can be obtained with low input power. Hereinafter, the capacity per unit volume is also referred to as "CAP", and the coefficient of performance is also referred to as "COP".

[0025] HFO-1123 has a low GWP, and although the CAP is high in the cycle performance, there is still room for improvement in the COP. As a method of improving the COP while utilizing the low GWP and high CAP of HFO-1123, it is possible to consider mixing HFO-1123 with HFC-152a. HFC-152a is a compound with a relatively low GWP and can obtain a high COP. Therefore, an improvement in the COP can be expected. However, HFC-152a is more flammable than HFO-1123.

[0026] Here, for a working medium containing a highly flammable compound, from the viewpoint of safety, it is required that not only the composition at the time of mixing, that is, the initial composition, but also the composition after volatilization and leakage due to transportation, etc., that is, the leakage composition, has low flammability. Therefore, as a working medium that is a mixture of a highly flammable compound and a low-flammability compound, when the compound with the highest flammability in the mixture is designated as compound A, it is preferably to satisfy the following condition 1 or condition 2. Condition 1: Among the compounds contained in the mixture, compound A has the lowest boiling point Condition 2: The mixture contains compound B that is less flammable than compound A and has a lower boiling point than compound A, and compound C that is less flammable than compound A and has a higher boiling point than compound A The working medium that satisfies the above-mentioned condition 1 or condition 2 contains compound C which has lower flammability than compound A and a higher boiling point than compound A. Therefore, even if volatilization and leakage occur during transportation or the like, since the boiling points of compound A or compound B are lower than that of compound C, compound C is prone to concentration, and the concentration of compound A is not likely to occur. Therefore, as long as the flammability of the initial composition is considered, it is easy to select the composition of the working medium as a mixture.

[0027] In the working medium composed of HFO-1123 and HFC-152a, the boiling point of HFC-152a with the highest flammability is -24°C, and the boiling point of HFO-1123 which has lower flammability than HFC-152a is -61°C. Therefore, it does not satisfy the above-mentioned condition 1 and condition 2. Thus, in the present embodiment, as a compound that has lower flammability than HFC-152a and a higher boiling point than it, HFO-1234ze(E) with a boiling point of -19°C is used. HFO-1234ze(E) is a compound with low GWP, an extremely low ozone depletion potential due to not having chlorine atoms, and low combustion heat. Therefore, the working medium of the present embodiment can not only suppress the impact on the ozone layer, but also satisfies the above-mentioned condition 2, and suppresses the combustion heat by using the low GWP and high CAP of HFO-1123 and the high COP of HFC-152a.

[0028] When the content rate of HFO-1123 relative to the total of HFO-1123, HFC-152a and HFO-1234ze(E) is denoted as X mass%, from the viewpoint of improving CAP, X is preferably 3.0 or more, more preferably 4.0 or more, and further preferably 5.0 or more. In addition, from the viewpoint of improving COP, X is preferably 93.0 or less, more preferably 90.0 or less, and further preferably 85 or less. When the content rate of HFC-152a relative to the total of HFO-1123, HFC-152a and HFO-1234ze(E) is denoted as Y mass%, from the viewpoint of improving COP, Y is preferably 2.0 or more, more preferably 3.0 or more, and further preferably 4.0 or more. In addition, from the viewpoint of reducing the combustion heat, Y is preferably 80.0 or less, more preferably 75.0 or less, and further preferably 70.0 or less. When the content rate of HFO-1234ze(E) relative to the total of HFO-1123, HFC-152a and HFO-1234ze(E) is denoted as Z mass%, from the viewpoint of reducing the combustion heat, Z is preferably 5.0 or more, more preferably 6.0 or more, and further preferably 7.0 or more. In addition, from the viewpoint of improving CAP, Z is preferably 90.0 or less, more preferably 85.0 or less, and further preferably 80.0 or less.

[0029] <Optional component> The working medium of the present disclosure may also optionally contain, according to needs, compounds of any components used as common working media other than HFO-1123, HFC-152a, and HFO-1234ze(E). However, the total content rate of HFO-1123, HFC-152a, and HFO-1234ze(E) is preferably 80.0% by mass or more, more preferably 90.0% by mass or more, and still more preferably 95.0% by mass or more with respect to the whole working medium.

[0030] As the above-mentioned arbitrary components, for example, HFCs other than HFC-152a, HFOs other than HFO-1123 and HFO-1234ze(E), and other components that vaporize and liquefy together with HFO-1123 can be cited. Examples of HFCs as arbitrary components include trifluoroethane, 1,1,2,2-tetrafluoroethane (HFC-134), pentafluoropropane, hexafluoropropane, heptafluoropropane, pentafluorobutane, heptafluorocyclopentane, etc. Examples of HFOs as arbitrary components include 1,2-difluoroethylene (HFO-1132), 2-fluoropropene (HFO-1261yf), 1,1,2-trifluoropropene (HFO-1243yc), 1,2,3,3,3-pentafluoropropene (HFO-1225ye), 3,3,3-trifluoropropene (HFO-1243zf), etc.

[0031] In addition, as arbitrary components other than the above-mentioned HFCs and HFOs, hydrocarbons such as propylene, cyclopropane, butane, isobutane, pentane, isopentane, etc., chlorofluoroolfins (CFO) such as 1,1-dichloro-2,3,3,3-tetrafluoropropene (CFO-1214ya), 1,3-dichloro-1,2,3,3-tetrafluoropropene (CFO-1214yb), 1,2-dichloro-1,2-difluoroethylene (CFO-1112), etc., and hydrochlorofluoroolfins (HCFO) such as 1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd), 1-chloro-1,2-difluoroethylene (HCFO-1122), etc. can be cited. As arbitrary components, components with little impact on the ozone layer and little impact on global warming are preferred.

[0032] <Composition and Characteristics of Working Medium> From the viewpoint of improving CAP, the content rate of HFO-1123 with respect to the whole working medium is preferably 3.0% by mass or more, more preferably 4.0% by mass or more, and still more preferably 5.0% by mass or more. In addition, from the viewpoint of improving COP, the content rate of HFO-1123 with respect to the whole working medium is preferably 93.0% by mass or less, more preferably 90.0% by mass or less, and still more preferably 85.0% by mass or less. From the viewpoint of improving the COP, the content rate of HFC-152a relative to the whole working medium is preferably 2.0% by mass or more, more preferably 3.0% by mass or more, and still more preferably 4.0% by mass or more. In addition, from the viewpoint of reducing the combustion heat, the content rate of HFC-152a relative to the whole working medium is preferably 80.0% by mass or less, more preferably 75.0% by mass or less, and still more preferably 70.0% by mass or less. From the viewpoint of reducing the combustion heat, the content rate of HFO-1234ze(E) relative to the whole working medium is preferably 5.0% by mass or more, more preferably 6.0% by mass or more, and still more preferably 7.0% by mass or more. In addition, from the viewpoint of improving the CAP, the content rate of HFO-1234ze(E) relative to the whole working medium is preferably 90.0% by mass or less, more preferably 85.0% by mass or less, and still more preferably 80.0% by mass or less.

[0033] From the viewpoint of the small impact of the working medium on global warming, the lower the GWP of the working medium, the more preferable. The GWP of the working medium is preferably 150 or less, more preferably 130 or less, still more preferably 100 or less, and particularly preferably 45 or less. The lower the combustion heat of the working medium, the more preferable. The combustion heat (HOC) of the working medium is preferably 15.300 MJ / kg or less, more preferably 15.000 MJ / kg or less, still more preferably 14.500 MJ / kg or less, and particularly preferably 14.000 MJ / kg or less.

[0034] <Temperature gradient (TG)> The working medium of the present disclosure has a temperature gradient because it is a mixture of compounds with a huge difference in boiling points. Here, the above-mentioned temperature gradient is an index value for evaluating the usability of the mixed working medium, and it is defined as the property that the starting temperature and the finishing temperature of evaporation in an evaporator or condensation in a condenser in a heat exchanger are different, and is also called "temperature step". The temperature gradient of an azeotropic mixed medium is 0, and the temperature gradient of a near-azeotropic mixture such as R410A is extremely close to 0. If the temperature gradient of the working medium is large, the possibility of frosting may increase due to a decrease in the inlet temperature of the evaporator, for example. In addition, in a heat cycle system, in order to improve the heat exchange efficiency, the working medium flowing in the heat exchanger is usually made to form convection with a heat source fluid such as water and air. Then, in a steady operation state, the temperature difference of the heat source fluid is small. Therefore, when the temperature gradient of the working medium is large, it is difficult to obtain a heat cycle system with good energy efficiency. Therefore, a working medium with a small temperature gradient is desired.

[0035] The temperature gradient (TG) of the working medium in the evaporator is preferably 7.0 °C or less, more preferably 6.5 °C or less, and further preferably 6.0 °C or less. In addition, the temperature gradient of the evaporator is a value calculated from the difference between the evaporation start temperature and the evaporation completion temperature in the evaporator, and is a value measured using the standard refrigeration cycle under the following temperature conditions in the refrigeration cycle system described later. (Temperature conditions of the standard refrigeration cycle) Evaporation temperature: 5 °C (average temperature of the evaporation start temperature and the evaporation completion temperature) Condensation temperature: 40 °C (average temperature of the condensation start temperature and the condensation completion temperature) Subcooling degree (SC): 5 °C Superheat degree (SH): 5 °C Compressor efficiency: 0.7

[0036] The temperature gradient of the working medium in the evaporator varies with the mixing ratio of HFO-1123, HFC-152a, and HFO-1234ze(E). Regarding the relationship between the above mixing ratio and the temperature gradient of the evaporator, it has been confirmed that the temperature gradients of the working medium of the following Composition A and the working medium of the following Composition B in the evaporator are 7.0 or less. Hereinafter, based on the total of HFO-1123, HFC-152a, and HFO-1234ze(E), the content rate of HFO-1123 is set to X mass%, the content rate of HFC-152a is set to Y mass%, and the content rate of HFO-1234ze(E) is set to Z mass%.

[0037] <Working medium of Composition A> The working medium of Composition A satisfies the following formulas (1) and (2). Formula (1): 2.0 ≤ Y ≤ 18.34 Formula (2): Z ≤ -0.01611 × Y 2 -0.36606 × Y + 17.14

[0038] The working medium of Composition A has high cycle performance, and has a lower GWP compared to R410A with a GWP of 2256, and also has a lower combustion heat. Therefore, it is suitable as an alternative composition to R410A. The GWP of the working medium of Composition A is preferably 45 or less, more preferably 30 or less, and further preferably 20 or less. The combustion heat (HOC) of the working medium of Composition A is preferably 12,000 MJ / kg or less, more preferably 11,500 MJ / kg or less, and further preferably 11,000 MJ / kg or less.

[0039] From the perspective of improving CAP, X in the working medium of Component A is preferably 76.7 or more, more preferably 77.0 or more, further preferably 78.0 or more, and particularly preferably 80.0 or more. In addition, from the perspective of improving COP, X in the working medium of Component A is preferably 93.0 or less, more preferably 90.0 or less, and further preferably 85.0 or less. Y in the working medium of Component A is 2.0 or more, and from the perspective of improving COP, it is preferably 3.0 or more, more preferably 4.0 or more. In addition, Y in the working medium of Component A is 18.34 or less, and from the perspective of reducing combustion heat, it is preferably 17.0 or less, more preferably 16.0 or less. From the perspective of reducing combustion heat, Z in the working medium of Component A is preferably 5.0 or more, more preferably 6.0 or more, and further preferably 7.0 or more. In addition, from the perspective of reducing the temperature gradient, Z in the working medium of Component A is preferably 16.34 or less, more preferably 16.0 or less, and further preferably 15.0 or less.

[0040] The relative cooling capacity RCAP of the working medium of Component A with respect to R410A R410A is preferably 0.93 or more, more preferably 0.94 or more, and further preferably 0.95 or more. The relative cooling capacity RCAP R410A is the value obtained by setting the cooling capacity of R410A as CAP R410A and setting the cooling capacity of the working medium of Component A as CAP A when it is CAP A / CAP R410A as represented by the value. In addition, the above-mentioned cooling capacity CAP is the cooling capacity per unit volume of the evaporator, and is calculated by the product of the saturated gas density at the compressor inlet and the latent heat of evaporation. Specifically, the cooling capacity CAP is the value obtained by using the aforementioned standard refrigeration cycle and the method described below. In addition, the product of the cooling capacity per unit volume CAP and the volume flow rate is equivalent to the output power Q (kW) of the circulation system. The above-mentioned relative cooling capacity RCAP R410A shows the relative cooling capacity of Component A with respect to R410A.

[0041] The relative coefficient of performance RCOP of the working medium of Component A with respect to R410A R410A is preferably 0.96 or more, more preferably 0.97 or more, and further preferably 0.98 or more. The relative coefficient of performance RCOP R410A is the value obtained by setting the coefficient of performance of R410A as COP R410A and setting the coefficient of performance of the working medium of Component A as COP A when it is COP A / COP R410A as represented by the value. In addition, the above-mentioned coefficient of performance COP is the value obtained by dividing the output power Q (kW) by the driving power P (kW) consumed to obtain the output power Q (kW), which is equivalent to the energy consumption efficiency. The higher the value of COP, the higher the output power can be obtained with a lower input power. Specifically, the coefficient of performance COP is the value obtained by using the aforementioned standard refrigeration cycle and the formula considering the compressor efficiency in the following method. The above-mentioned relative coefficient of performance RCOP R410A shows the relative coefficient of performance of Component A with respect to R410A.

[0042] <Working medium of Component B> The working medium of Component B satisfies the following formulas (3) and (4). Formula (3): 2.0 ≤ Y ≤ 76.25 Formula (4): Z ≥ 0.00279 × Y 2 -1.25979 × Y + 84.84

[0043] The working medium of Component B has high cycle performance, low GWP, and low combustion heat compared with HFO-1234yf. Therefore, it is suitable as an alternative composition to HFO-1234yf. The GWP of the working medium of Component B is preferably 150 or less, more preferably 130 or less, and further preferably 100 or less. The combustion heat (HOC) of the working medium of Component B is preferably 15,300 MJ / kg or less, more preferably 15,000 MJ / kg or less, and further preferably 14,500 MJ / kg or less.

[0044] From the perspective of improving CAP, X in the working medium of Component B is preferably 3.0 or more, more preferably 4.0 or more, and further preferably 5.0 or more. In addition, from the perspective of improving COP, X in the working medium of Component B is preferably 21.2 or less, more preferably 20.0 or less, and further preferably 19.0 or less. Y in the working medium of Component B is 2.0 or more, and from the perspective of improving COP, it is preferably 3.0 or more, more preferably 4.0 or more. In addition, Y in the working medium of Component B is 76.25 or less, and from the perspective of reducing combustion heat, it is preferably 75.0 or less, more preferably 70.0 or less. From the perspective of reducing combustion heat, Z in the working medium of Component B is preferably 4.9 or more, more preferably 5.0 or more, further preferably 6.0 or more, and particularly preferably 7.0 or more. In addition, from the perspective of improving CAP, Z in the working medium of Component B is preferably 90.0 or less, more preferably 85.0 or less, and further preferably 80.0 or less.

[0045] The relative refrigerating capacity RCAP of the working medium of Component B with respect to HFO-1234yf 1234yf is preferably 0.98 or more, more preferably 0.99 or more, and still more preferably 1.00 or more. The relative refrigerating capacity RCAP 1234yf is the value obtained by setting the refrigerating capacity of HFO-1234yf as CAP 1234yf and setting the refrigerating capacity of the working medium of Component B as CAP B and taking the value represented by CAP B / CAP 1234yf The above-mentioned refrigerating capacity CAP is a value obtained by using the aforementioned standard refrigeration cycle and the method described below. The above relative refrigerating capacity RCAP shows the relative refrigerating capacity of Component B with respect to HFO-1234yf 1234yf

[0046] The relative coefficient of performance RCOP of the working medium of Component B with respect to HFO-1234yf 1234yf is preferably 1.06 or more, more preferably 1.07 or more, and still more preferably 1.08 or more. The relative coefficient of performance RCOP 1234yf is the value obtained by setting the coefficient of performance of HFO-1234yf as COP 1234yf and setting the coefficient of performance of the working medium of Component B as COP B and taking the value represented by COP B / COP 1234yf The above-mentioned coefficient of performance COP is a value obtained by using the aforementioned standard refrigeration cycle and the formula considering the compressor efficiency in the method described below. The above relative coefficient of performance RCOP shows the relative coefficient of performance of Component B with respect to HFO-1234yf 1234yf

[0047] [Composition for thermal cycle system] The composition for thermal cycle system according to one embodiment of the present disclosure includes the aforementioned working medium for thermal cycle, and may further include other components as needed When the above-mentioned working medium for thermal cycle is used in a thermal cycle system, for example, the above-mentioned working medium for thermal cycle can be mixed with refrigeration oil and used as the composition for thermal cycle system of the present embodiment. The composition for thermal cycle system of the present embodiment containing the above-mentioned working medium for thermal cycle and refrigeration oil may further contain known additives such as stabilizers and leak detection substances in addition to these components

[0048] (Refrigeration oil) ​​As the refrigeration oil, a known refrigeration oil that has been commonly used in a heat cycle system composition together with a conventional working medium composed of a halogenated hydrocarbon can be employed without particular limitation. As the refrigeration oil, specifically, oxygen-containing synthetic oils (such as ester-based refrigeration oils and ether-based refrigeration oils), fluorine-based refrigeration oils, mineral-based refrigeration oils, hydrocarbon-based synthetic oils, etc. can be cited.

[0049] As the ester-based refrigeration oil, dibasic acid ester oils, polyol ester oils, complex ester oils, polyol carbonate oils, etc. can be cited.

[0050] As the dibasic acid ester oil, an ester of a dibasic acid having 5 to 10 carbon atoms (such as glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, etc.) and a monohydric alcohol having a linear or branched alkyl group and 1 to 15 carbon atoms (such as methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, etc.) is preferred. As the dibasic acid ester oil, specifically, di(tridecyl) glutarate, bis(2-ethylhexyl) adipate, diisodecyl adipate, di(tridecyl) adipate, bis(3-ethylhexyl) sebacate, etc. can be cited.

[0051] As the polyol ester oil, an ester of a diol (such as ethylene glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol, 1,2-butanediol, 1,5-pentanediol, neopentyl glycol, 1,7-heptanediol, 1,12-dodecanediol, etc.) or a polyol having 3 or more and 20 or less hydroxyl groups (such as trimethylolethane, trimethylolpropane, trimethylolbutane, pentaerythritol, glycerin, sorbitol, sorbitan, sorbitol glycerol condensate, etc.) and a fatty acid having 6 to 20 carbon atoms (such as a linear or branched fatty acid like hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, eicosanoic acid, oleic acid, etc. or a so-called neo acid in which the α carbon atom is a quaternary carbon atom) is preferred. Additionally, these polyol ester oils may also have free hydroxyl groups.

[0052] As the polyol ester oil, esters of hindered alcohols (such as neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, pentaerythritol, etc.) (such as trimethylolpropane trinonanoate, pentaerythritol 2-ethylhexanoate, pentaerythritol tetranonanoate, etc.) are preferred.

[0053] The complex ester oil refers to an ester of a fatty acid and a dibasic acid with a monohydric alcohol and a polyol. As the fatty acid, dibasic acid, monohydric alcohol, and polyol, the same components as those described above can be used.

[0054] A polyol carbonate oil refers to an ester of carbonic acid and a polyol. As the polyol, the same diols or polyols as described above can be cited. In addition, as the polyol carbonate oil, it can also be a ring-opening polymer of a cyclic alkylene carbonate.

[0055] As an ether-based refrigerant oil, polyvinyl ether oil or polyoxyalkylene oil can be cited.

[0056] As polyvinyl ether oil, there are copolymers obtained by polymerizing vinyl ether monomers such as alkyl vinyl ether and copolymers obtained by copolymerizing vinyl ether monomers with hydrocarbon monomers having an olefinic double bond.

[0057] One type of vinyl ether monomer can be used alone, or two or more types can be used in combination.

[0058] As hydrocarbon monomers having an olefinic double bond, ethylene, propylene, various butenes, various pentenes, various hexenes, various heptenes, various octenes, diisobutene, triisobutene, styrene, α-methylstyrene, various alkyl-substituted styrenes, etc. can be cited. One type of hydrocarbon monomer having an olefinic double bond can be used alone, or two or more types can be used in combination.

[0059] The polyvinyl ether copolymer can be either a block copolymer or a random copolymer. One type of polyvinyl ether oil can be used alone, or two or more types can be used in combination.

[0060] As polyoxyalkylene oil, polyoxyalkylene monohydric alcohols, polyoxyalkylene polyhydric alcohols, alkyl ether compounds of polyoxyalkylene monohydric alcohols or polyoxyalkylene polyhydric alcohols, ester compounds of polyoxyalkylene monohydric alcohols or polyoxyalkylene polyhydric alcohols, etc. can be cited.

[0061] Examples of the polyoxyalkylene monohydric alcohol or polyoxyalkylene polyhydric alcohol include those obtained by a method such as ring-opening addition polymerization of an alkylene oxide having 2 to 4 carbon atoms (ethylene oxide, propylene oxide, etc.) to an initiator such as water or a hydroxyl group-containing compound in the presence of a catalyst such as an alkali hydroxide. In addition, the oxyalkylene units in the polyoxyalkylene chain can be the same in one molecule or can contain two or more types of oxyalkylene units. It is preferably to contain at least an oxypropylene unit in one molecule.

[0062] As the initiator used in the reaction, monohydric alcohols such as water, methanol or butanol, and polyhydric alcohols such as ethylene glycol, propylene glycol, pentaerythritol, glycerol, etc. can be cited.

[0063] As polyoxyalkylene oil, alkyl ether compounds or ester compounds of polyoxyalkylene monohydric alcohols or polyoxyalkylene polyhydric alcohols are preferred. In addition, as polyoxyalkylene polyhydric alcohols, polyalkylene diols are preferred. In particular, alkyl ether compounds of polyalkylene diols in which the terminal hydroxyl groups of polyalkylene diols called polyglycol oils are blocked with alkyl groups such as methyl are preferred.

[0064] As fluorine-based refrigeration oils, compounds in which hydrogen atoms of synthetic oils (mineral oils, poly-α-olefins, alkylbenzenes, alkylnaphthalenes, etc., described later) are replaced by fluorine atoms, perfluoropolyether oils, fluorosilicone oils, etc. can be cited.

[0065] As mineral refrigeration oils, paraffinic mineral oils, naphthenic mineral oils, etc. obtained by purifying refrigeration oil fractions obtained by atmospheric distillation or vacuum distillation of crude oil through appropriately combined purification treatments (solvent removal, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, clay treatment, etc.) can be cited.

[0066] As hydrocarbon synthetic oils, poly-α-olefins, alkylbenzenes, alkylnaphthalenes, etc. can be cited.

[0067] The refrigeration oil can be used alone as one kind, or two or more kinds can be used in combination.

[0068] As the refrigeration oil, from the viewpoint of compatibility with the working medium for the heat cycle, one or more selected from polyol ester oils, polyvinyl ether oils, and polyglycol oils are preferred.

[0069] The content of the refrigeration oil in the composition for the heat cycle system may be within a range that does not significantly reduce the effects of the present invention. Relative to 100 parts by mass of the working medium for the heat cycle, it is preferably 10 parts by mass or more and 100 parts by mass or less, and more preferably 20 parts by mass or more and 50 parts by mass or less.

[0070] (Additive) The stabilizer optionally contained in the composition for the heat cycle system is a component that improves the stability of the working medium for the heat cycle against heat and oxidation. As the stabilizer, known stabilizers that have been commonly used in heat cycle systems together with conventional working media composed of halogenated hydrocarbons can be used without particular limitation. For example, oxidation resistance enhancers, heat resistance enhancers, metal deactivators, etc.

[0071] As oxidation resistance enhancers and heat resistance enhancers, N,N'-diphenylbenzidine, p-octyldiphenylamine, p,p'-dioctyldiphenylamine, N-phenyl-1-naphthylamine, N-phenyl-2-naphthylamine, N-(p-dodecyl)phenyl-2-naphthylamine, di-1-naphthylamine, di-2-naphthylamine, N-alkylphenothiazine, 6-(tert-butyl)phenol, 2,6-di-(tert-butyl)phenol, 4-methyl-2,6-di-(tert-butyl)phenol, 4,4'-methylenebis(2,6-di-tert-butylphenol), etc. can be cited. The oxidation resistance enhancer and the heat resistance enhancer can be used alone as one kind, or two or more kinds can be used in combination.

[0072] Examples of the metal deactivator include imidazole, benzimidazole, 2-mercaptobenzothiazole, 2,5-dimercapto-1,3,4-thiadiazole, salicylidene propylenediamine, pyrazole, benzotriazole, tolyltriazole, 2-methylbenzimidazole, 3,5-dimethylpyrazole, methylene bis-benzotriazole, an organic acid or its ester, an aliphatic primary amine, an aliphatic secondary amine or an aliphatic tertiary amine, an amine salt of an organic acid or an inorganic acid, a heterocyclic nitrogen-containing compound, an amine salt of an alkyl acid phosphate or a derivative thereof, etc.

[0073] The content of the stabilizer in the composition for a heat cycle system may be within a range that does not significantly reduce the effects of the present invention. Preferably, it is 5 parts by mass or less, more preferably 1 part by mass or less, relative to 100 parts by mass of the working medium for heat cycle.

[0074] Examples of the leak detection substance optionally contained in the composition for a heat cycle system include an ultraviolet fluorescent dye, an odor gas, an odor masking agent, etc.

[0075] Examples of the ultraviolet fluorescent dye include those described in U.S. Patent No. 4,249,412, Japanese Patent Application Laid-Open No. 10-502737, Japanese Patent Application Laid-Open No. 2007-511645, Japanese Patent Application Laid-Open No. 2008-500437, Japanese Patent Application Laid-Open No. 2008-531836, etc., and known ultraviolet fluorescent dyes that have been conventionally used in combination with a working medium composed of a halogenated hydrocarbon in a heat cycle system.

[0076] Examples of the odor masking agent include those described in Japanese Patent Application Laid-Open No. 2008-500437, Japanese Patent Application Laid-Open No. 2008-531836, etc., and known fragrances that have been conventionally used in combination with a working medium composed of a halogenated hydrocarbon in a heat cycle system.

[0077] When using a leak detection substance, a solubilizer that improves the solubility of the leak detection substance in the working medium for heat cycle may also be used.

[0078] Examples of the solubilizer include those described in Japanese Patent Application Laid-Open No. 2007-511645, Japanese Patent Application Laid-Open No. 2008-500437, Japanese Patent Application Laid-Open No. 2008-531836, etc.

[0079] The content of the leak detection substance in the composition for a heat cycle system may be within a range that does not significantly reduce the effects of the present invention. Preferably, it is 2 parts by mass or less, more preferably 0.5 part by mass or less, relative to 100 parts by mass of the working medium for heat cycle.

[0080] [Heat cycle system] The thermal cycle system of one embodiment of the present disclosure is a system that uses the above-described composition for a thermal cycle system. The thermal cycle system of this embodiment can be either a heat pump system that utilizes the warmth obtained from a condenser or a refrigeration cycle system that utilizes the cold obtained from an evaporator.

[0081] Specific examples of the thermal cycle system of this embodiment include refrigeration and cold storage equipment, air conditioning equipment, power generation systems, heat transfer devices, and secondary coolers. Among them, the thermal cycle system of this embodiment can stably and safely exhibit thermal cycle performance even in a higher-temperature working environment, and thus is preferably used as air conditioning equipment that is usually installed outdoors or the like. In addition, the thermal cycle system of this embodiment is preferably used as refrigeration and cold storage equipment.

[0082] Specific examples of air conditioning equipment include household air conditioners (such as indoor air conditioners, central air conditioners, etc.), commercial air conditioners (such as shop-use packaged air conditioners, building-use packaged air conditioners, equipment-use packaged air conditioners, etc.), gas engine heat pumps, train air conditioning units, and motor vehicle air conditioning units. The motor vehicle air conditioning unit is preferably an air conditioning device for a fuel vehicle, a hybrid vehicle, an electric vehicle, or a hydrogen energy vehicle, and more preferably an air conditioning device for an electric vehicle.

[0083] Specific examples of refrigeration and cold storage equipment include display cabinets (such as built-in display cabinets, free-standing display cabinets, etc.), commercial refrigerators and cold storage warehouses, vending machines, and ice makers.

[0084] As the power generation system, a power generation system that utilizes a Rankine cycle system is preferred. Specific examples of the power generation system include a system in which a working medium is heated in an evaporator using geothermal energy, solar heat, waste heat in a medium to high temperature range of about 50°C or more and 200°C or less to become steam in a high-temperature and high-pressure state, and the working medium adiabatically expands in an expander, and the generator is driven to generate electricity by the work generated by this adiabatic expansion.

[0085] As the heat transfer device, a latent heat transfer device is preferred. Examples of the latent heat transfer device include a heat pipe and a two-phase closed thermosyphon device that perform latent heat transfer by utilizing phenomena such as evaporation, boiling, and condensation of the working medium enclosed in the device. The heat pipe is suitable for relatively small cooling devices such as cooling devices for the heat-generating parts of semiconductor elements or electronic devices. Since the two-phase closed thermosyphon device does not require a wick and has a simple structure, it is widely used in gas-type heat exchangers, promoting road snow melting, and anti-freezing.

[0086] Figure 1 Shown is a schematic structural diagram of a refrigeration cycle system as an example of the thermal cycle system of this embodiment. Hereinafter, using Figure 1The refrigeration cycle system shown below explains a method for determining the refrigerating capacity and coefficient of performance of a working medium for a specified heat cycle.

[0087] As Figure 1 shown, the refrigeration cycle system 10 includes: a compressor 11 that compresses the working medium vapor A for the heat cycle into a high-temperature and high-pressure working medium vapor B for the heat cycle; a condenser 12 that cools and liquefies the working medium vapor B discharged from the compressor 11 into a low-temperature and high-pressure working medium C for the heat cycle; an expansion valve 13 that expands the working medium C discharged from the condenser 12 into a low-temperature and low-pressure working medium D for the heat cycle; an evaporator 14 that heats the working medium D discharged from the expansion valve 13 into a high-temperature and low-pressure working medium vapor A for the heat cycle; a pump 15 that supplies a load fluid E to the evaporator 14; and a pump 16 that supplies a fluid F to the condenser 12.

[0088] In the refrigeration cycle system 10, the following cycles (i) to (iv) (refrigeration cycle) are repeated.

[0089] (i) The working medium vapor A discharged from the evaporator 14 is compressed in the compressor 11 into a high-temperature and high-pressure working medium vapor B for the heat cycle. This is hereinafter referred to as the "AB process". (ii) The working medium vapor B discharged from the compressor 11 is cooled and liquefied in the condenser 12 by the fluid F into a low-temperature and high-pressure working medium C for the heat cycle. At this time, the fluid F is heated into a fluid F' and discharged from the condenser 12. This is hereinafter referred to as the "BC process". (iii) The working medium C discharged from the condenser 12 is expanded in the expansion valve 13 into a low-temperature and low-pressure working medium D for the heat cycle. This is hereinafter referred to as the "CD process". (iv) The working medium D discharged from the expansion valve 13 is heated in the evaporator 14 by the load fluid E into a high-temperature and low-pressure working medium vapor A for the heat cycle. At this time, the load fluid E is cooled into a load fluid E' and discharged from the evaporator 14. This is hereinafter referred to as the "DA process".

[0090] The refrigeration cycle system 10 is a cycle system composed of adiabatic - isentropic changes, isenthalpic changes, and isobaric changes. Figure 2 Shown is the Figure 1 cycle diagram in which the state changes of the working medium for the heat cycle in the refrigeration cycle system 10 are recorded on a pressure - enthalpy diagram. If the state changes of the working medium for the heat cycle are recorded on the Figure 2 pressure - enthalpy line (curve) diagram shown, it can be represented as a trapezoid with A, B, C, and D as vertices.

[0091] The AB process is a process of adiabatic compression in the compressor 11 to convert the working medium steam A for the heat cycle at high temperature and low pressure into the working medium steam B for the heat cycle at high temperature and high pressure. As described later, the working medium steam A for the heat cycle is introduced into the compressor 11 in a superheated state, and the resulting working medium steam B for the heat cycle is also in a superheated state. The density of the gas sucked by the compressor is the density (ρs) in the A state in Figure 2 . The pressure of the gas discharged from the compressor (discharge pressure) is the pressure (Px) in the B state in Figure 2 , which is the highest pressure in the refrigeration cycle. Among them, the BC process is isobaric cooling, so the discharge pressure shows the same value as the condensation pressure (Pc). Therefore, in Figure 2 , for convenience, the condensation pressure is represented by Px. Figure 2

[0092] The BC process is a process of isobaric cooling in the condenser 12 to convert the working medium steam B for the heat cycle at high temperature and high pressure into the working medium C for the heat cycle at low temperature and high pressure. It is represented by the BC line in Figure 2 . The pressure at this time is the condensation pressure. Among the intersections of the pressure-enthalpy line and the BC line, the intersection T on the high-enthalpy side 1 is the condensation temperature, and the intersection T on the low-value side 2 is the condensation boiling point temperature. Here, the temperature gradient of the condenser is represented by the difference between T 1 and T 2 .

[0093] The CD process is a process of isenthalpic expansion in the expansion valve 13 to convert the working medium C for the heat cycle at low temperature and high pressure into the working medium D for the heat cycle at low temperature and low pressure. It is represented by the CD line in Figure 2 . Among them, if the temperature of the working medium C for the heat cycle at low temperature and high pressure is represented by T 3 , then T 2 -T 3 is the subcooling degree (SC) of the working medium for the heat cycle in the (i)-(iv) cycles.

[0094] The DA process is a process of isobaric heating in the evaporator 14 to convert the working medium D for the heat cycle at low temperature and low pressure back into the working medium steam A for the heat cycle at high temperature and low pressure. It is represented by the DA line in Figure 2 . The pressure at this time is the evaporation pressure (Py). Among the intersections of the pressure-enthalpy line and the DA line, the intersection T on the high-enthalpy side 6 is the evaporation temperature. If the temperature of the working medium steam A is represented by T 7 , then T 7 -T 6 is the superheat degree (SH) of the working medium for the heat cycle in the (i)-(iv) cycles. In addition, T 4 4Represents the temperature of the working medium D for the heat cycle, T 5 Represents the temperature of the working medium D when the degree of subcooling (SC) is 0. Here, the temperature gradient of the evaporator is T 6 And T 4 The difference represents.

[0095] The CAP and COP of the working medium for the heat cycle are calculated respectively by the following formulas (5) to (8) using the enthalpies hA, hB, hC, and hD in the respective states A (after evaporation, high temperature and low pressure), B (after compression, high temperature and high pressure), C (after condensation, low temperature and high pressure), D (after expansion, low temperature and low pressure) of the working medium for the heat cycle and the refrigerant mass circulation rate qmr. In addition, in the following formulas (5) to (8), the pressure losses in the piping and heat exchanger are not considered.

[0096] The cycle performance (CAP and COP) of the working medium for the heat cycle is obtained by performing theoretical calculations of the refrigeration cycle of the working medium under the above conditions using the National Institute of Science and Technology (NIST) Reference Fluid Thermodynamic and Transport Properties Database (REFPROP 10.0). In addition, regarding the physical property data of HFO-1123, the values described in Thermodynamic properties of trifluoroethene (R1123): (p, ρ, T) behavior and fundamental equation of state by Akasaka, R., Higashi, Y., Sakoda, N., Fukuda, S. and Lemmon, E.W., International Journal of Refrigeration, 2020, 119, 457 - 467 are used.

[0097] CAP = (hA - hD) × ρs... Equation (5) COP = Q / P = (qmr × (hA - hD)) / (qmr × (hB - hA)) = (hA - hD) / (hB - hA)... Equation (6) Q = qmr × (hA - hD)... (7) P = qmr × (hB - hA)... (8) In the above formulas (5) to (8), ρs represents the compressor suction gas density (kg / m 3), where Q represents the output power (kW) and P represents the driving power (kW).

[0098] In addition, when the loss work of the compressor is applied to the working medium in the form of heat, if the compressor efficiency is set as η, the enthalpy hB’ of the working medium vapor B’ (after compression, high temperature and high pressure) after the AB process is expressed by the following formula (9) using hA, hB, and η. hB’ = hA + (hB - hA) / η…(9) Furthermore, when considering the compressor efficiency, COP and P are expressed by the following formulas (10) and (11). COP = Q / P = (hA - hD) / (hB’ - hA)…(10) P = qmr×(hB’ - hA)…(11) In the above formula (10), Q represents the output power (kW) and P represents the driving power (kW).

[0099] In addition, when the heat cycle system is in operation, in order to avoid adverse conditions caused by the mixing of moisture, non-condensable gases such as oxygen, etc., it is preferable to provide means for suppressing the mixing of these substances.

[0100] If moisture mixes into the heat cycle system, problems sometimes occur especially during low-temperature use. For example, problems such as ice formation in the capillary tube, hydrolysis of the working medium or refrigeration oil for the heat cycle, material deterioration caused by acid components generated during the cycle, and generation of contaminants may occur. Especially when the refrigeration oil is polyglycol oil, polyol ester oil, etc., its hygroscopicity is extremely high and it is prone to hydrolysis reaction, and its characteristics as a refrigeration oil are reduced, which will become the main reason for damaging the long-term reliability of the compressor. Therefore, in order to suppress the hydrolysis of the refrigeration oil, it is necessary to control the moisture concentration in the heat cycle system.

[0101] As a method for controlling the moisture concentration in the heat cycle system, a method using water removal means such as a desiccant (silica gel, activated alumina, zeolite, etc.) can be cited. From the perspective of dehydration efficiency, it is preferable to bring the desiccant into contact with the liquid heat cycle system composition. For example, it is appropriate to arrange the desiccant at the outlet of the condenser 12 or the inlet of the evaporator 14 to bring it into contact with the heat cycle system composition.

[0102] As the desiccant, from the perspectives of the chemical reactivity between the desiccant and the heat cycle system composition and the moisture absorption capacity of the desiccant, zeolite desiccants are preferable.

[0103] As the zeolite desiccant, when using a refrigeration oil with a higher moisture absorption amount compared to conventional mineral refrigeration oils, from the perspective of excellent moisture absorption capacity, a zeolite desiccant mainly composed of the compound represented by the following formula (12) is preferable.

[0104] M 2 / n O·Al 2 O 3 ·xSiO 2 ·yH 2 O…Formula (12)

[0105] Among them, M is a Group 1 element such as Na, K, etc. or a Group 2 element such as Ca, etc., n is the valence of M, and x and y are values determined by the crystal structure. By changing M, the pore diameter can be adjusted.

[0106] When selecting a desiccant, the pore diameter and crushing strength are important. When using a desiccant with a pore diameter larger than the molecular diameter of the working medium for the heat cycle in the heat cycle system composition, the working medium for the heat cycle will be adsorbed in the desiccant. As a result, the working medium for the heat cycle will chemically react with the desiccant to generate non-condensable gases, resulting in undesirable phenomena such as a decrease in the strength of the desiccant and a decline in the adsorption capacity.

[0107] Therefore, as a desiccant, it is preferable to use zeolite desiccants with a small pore diameter. In particular, sodium-potassium A-type synthetic zeolite with a pore diameter of 3.5 Å or less is preferred. By using sodium-potassium A-type synthetic zeolite with a pore diameter smaller than the molecular diameter of the working medium for the heat cycle, it is possible to selectively adsorb and remove only the moisture in the heat cycle system without adsorbing the working medium for the heat cycle. In other words, the working medium for the heat cycle is not easily adsorbed on the desiccant, so thermal decomposition is not likely to occur. As a result, the deterioration and contamination of the materials constituting the heat cycle system can be suppressed.

[0108] If the size of the zeolite desiccant is too small, it will cause blockage in the valves and detailed parts of the piping in the heat cycle system. If it is too large, the drying capacity will decrease. Therefore, it is preferably about 0.5 mm or more and 5 mm or less. As the shape of the zeolite desiccant, granular or cylindrical shapes are preferred.

[0109] The zeolite desiccant can be formed into any shape by solidifying powdery zeolite with an adhesive (such as bentonite). If the zeolite desiccant is the main component, other desiccants (such as silica gel, activated alumina, etc.) can also be used in combination. The usage ratio of the zeolite desiccant relative to the heat cycle system composition is not particularly limited.

[0110] Furthermore, if non-condensable gases are mixed into the heat cycle system, it will cause negative effects such as poor heat conduction in the condenser and evaporator and an increase in the working pressure. Therefore, it is necessary to strongly suppress their mixing. In particular, oxygen, one of the non-condensable gases, will react with the working medium for the heat cycle and the refrigeration oil to promote decomposition.

[0111] In the gas phase portion of the working medium for the heat cycle, the concentration of the non-condensable gas is preferably 1.5 vol% or less, particularly preferably 0.5 vol% or less, based on the volume ratio with respect to the working medium for the heat cycle.

[0112] The heat cycle system according to one embodiment of the present disclosure described above uses the working medium for the heat cycle of the present disclosure, has excellent durability, can suppress the impact on global warming, and can obtain sufficient practical cycle performance. Examples

[0113] Hereinafter, the embodiments of the present disclosure will be described in detail by way of examples, but the embodiments of the present disclosure are not limited thereto.

[0114] [Example A] Figure 1 In the refrigeration cycle system 10, when using the working medium having the composition shown in Table 1 below, the temperature gradient (TG (°C) in the table), the relative coefficient of performance RCOP with respect to R410A R410A (RCOP in the table R410A ), the relative refrigerating capacity RCAP with respect to R410A R410A (RCAP in the table R410A ) and the heat of combustion (HOC (MJ / kg) in the table) and GWP were obtained by the aforementioned method. The results are shown in Table 1. In addition, "1123 (mass%)" in the table represents the content rate of HFO-1123 with respect to the total of HFO-1123, HFC-152a and HFO-1234ze(E), "152a (mass%)" represents the content rate of HFC-152a with respect to the total of HFO-1123, HFC-152a and HFO-1234ze(E), and "1234ze(E) (mass%)" represents the content rate of HFO-1234ze(E) with respect to the total of HFO-1123, HFC-152a and HFO-1234ze(E). In addition, the working media of Examples A1 to A28 do not contain any components other than HFO-1123, HFC-152a and HFO-1234ze(E).

[0115] [Table 1]

[0116] In the above examples, Examples A1 to A27 are examples, and Example A28 is a comparative example. As shown in Table 1, Examples A1 to A27 have cycle performance comparable to that of R410A, have a significantly lower GWP than R410A, and have a lower HOC than Example A28.

[0117] [Example B] Figure 1 In the refrigeration cycle system 10, when using the working medium having the composition shown in Tables 2 to 3 below, the temperature gradient (TG (°C) in the table), the relative coefficient of performance RCOP with respect to HFO-1234yf are obtained by the aforementioned method 1234yf (RCOP in the table 1234yf ), the relative refrigerating capacity RCAP with respect to HFO-1234yf 1234yf (RCAP in the table 1234yf ), the heat of combustion (HOC (MJ / kg) in the table), and the GWP. The results are shown in Tables 2 to 3. In addition, "1123 (mass%)" in the table represents the content rate of HFO-1123 with respect to the total of HFO-1123, HFC-152a, and HFO-1234ze (E), "152a (mass%)" represents the content rate of HFC-152a with respect to the total of HFO-1123, HFC-152a, and HFO-1234ze (E), and "1234ze (E) (mass%)" represents the content rate of HFO-1234ze (E) with respect to the total of HFO-1123, HFC-152a, and HFO-1234ze (E). In addition, the working media of Examples B1 to B50 do not contain any components other than HFO-1123, HFC-152a, and HFO-1234ze (E).

[0118] [Table 2]

[0119] [Table 3]

[0120] In the above examples, Examples B1 to B49 are examples, and Example B50 is a comparative example. As shown in Tables 2 to 3, Examples B1 to B49 have high cycle performance compared with HFO-1234yf, low GWP compared with Example B50, and low HOC compared with Example B50. Industrial applicability

[0121] The working medium for a heat cycle and the heat cycle system using the composition for a heat cycle system of the present disclosure can be used in refrigeration and freezing equipment (built-in display cabinets, stand-alone display cabinets, commercial refrigeration and freezing warehouses, vending machines, ice makers, etc.), air conditioning equipment (room air conditioners, shop combined air conditioners, building combined air conditioners, equipment combined air conditioners, gas engine heat pumps, train air conditioning devices, motor vehicle air conditioning devices, etc.), power generation systems (waste heat recovery power generation, etc.), heat transfer devices (heat pipes, etc.), and secondary coolers.

[0122] The entire disclosure of Japanese Application No. 2022-172709, filed on October 27, 2022, is incorporated herein by reference. In addition, all documents, patent applications, and technical standards described in this specification are incorporated herein by reference to the same extent as if each document, patent application, and technical standard were specifically and individually set forth as incorporated by reference. Symbol Explanation

[0123] 10 Refrigeration cycle system 11 Compressor 12 Condenser 13 Expansion valve 14 Evaporator 15, 16 Pumps.

Claims

1. A working medium for thermal cycling, which comprises trifluoroethylene, 1,1-difluoroethane and (E)-1,3,3,3-tetrafluoropropene.

2. The working medium for thermal cycling according to claim 1, wherein when the content rate of 1,1-difluoroethane is set as Y mass % and the content rate of (E)-1,3,3,3-tetrafluoropropene is set as Z mass % with respect to the total of trifluoroethylene, 1,1-difluoroethane and (E)-1,3,3,3-tetrafluoropropene, the following formulas (1) and (2) are satisfied: Formula (1): 2.0 ≤ Y ≤ 18.34 Equation (2): Z ≤ -0.01611 × Y 2 -0.36606 × Y + 17.14 3. The working medium for thermal cycling according to claim 2, wherein the combustion heat of the working medium for thermal cycling is 12.000 MJ / kg or less.

4. The working medium for thermal cycling according to claim 2, wherein the global warming potential value of the working medium for thermal cycling is 45 or less.

5. The working medium for thermal cycling according to claim 1, wherein when the content rate of 1,1-difluoroethane is set as Y mass % and the content rate of (E)-1,3,3,3-tetrafluoropropene is set as Z mass % with respect to the total of trifluoroethylene, 1,1-difluoroethane and (E)-1,3,3,3-tetrafluoropropene, the following formulas (3) and (4) are satisfied: Formula (3): 2.0 ≤ Y ≤ 76.25 Formula (4): Z ≥ 0.00279 × Y 2 -1.25979 × Y + 84.84 6. The working medium for thermal cycling according to claim 5, wherein the combustion heat of the working medium for thermal cycling is 15.300 MJ / kg or less.

7. The working medium for thermal cycling according to claim 5, wherein the global warming potential value of the working medium for thermal cycling is 130 or less.

8. A composition for a thermal cycling system, which comprises the working medium for thermal cycling according to any one of claims 1 to 7.

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