Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K5/00—Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
  • C09K5/02—Materials undergoing a change of physical state when used
  • C09K5/04—Materials undergoing a change of physical state when used the change of state being from liquid to vapour or vice versa
  • C09K5/041—Materials undergoing a change of physical state when used the change of state being from liquid to vapour or vice versa for compression-type refrigeration systems
  • C09K5/044—Materials undergoing a change of physical state when used the change of state being from liquid to vapour or vice versa for compression-type refrigeration systems comprising halogenated compounds
  • C09K5/045—Materials undergoing a change of physical state when used the change of state being from liquid to vapour or vice versa for compression-type refrigeration systems comprising halogenated compounds containing only fluorine as halogen
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K2205/00—Aspects relating to compounds used in compression type refrigeration systems
  • C09K2205/10—Components
  • C09K2205/12—Hydrocarbons
  • C09K2205/126—Unsaturated fluorinated hydrocarbons
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K2205/00—Aspects relating to compounds used in compression type refrigeration systems
  • C09K2205/22—All components of a mixture being fluoro compounds
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K2205/00—Aspects relating to compounds used in compression type refrigeration systems
  • C09K2205/40—Replacement mixtures

Definitions

• This disclosure relates to a working medium for a heat cycle and a composition for a heat cycle system.
• chlorofluorocarbons such as chlorotrifluoromethane and dichlorodifluoromethane
• hydrochlorofluorocarbons such as chlorodifluoromethane
• CFCs and HCFCs are currently subject to regulation due to their impact on the stratospheric ozone layer.
• HFCs hydrofluorocarbons
• HFC-32 difluoromethane
• HFC-125 pentafluoroethane
• R410A a pseudo-azeotropic mixture refrigerant with a mass ratio of HFC-32 and HFC-125 of 1:1
• HFCs may be a cause of global warming.
• R410A Due to its high refrigeration capacity, R410A has been widely used in air conditioning equipment such as commercial air conditioners and home air conditioners. However, R410A has a high global warming potential (GWP) of 2256. For this reason, there is a demand for the development of a working medium with a low GWP. In this regard, there is a demand for the development of a working medium that can simply replace R410A and continue to be used in the equipment that has been used up until now.
• GWP global warming potential
• Patent Document 1 describes a composition containing fluoroethane (HFC-161), trifluoroethylene (HFO-1123), 1,1-difluoroethane (HFC-152a), and trifluoroiodomethane (CF 3 I) as a working medium that can replace R410A.
• Patent Document 1 when the composition disclosed in Patent Document 1 is used as a working medium, pressure loss is likely to increase. Pressure loss depends on both the characteristics of the path through which the working medium passes and the physical properties of the working medium itself. For this reason, there is a demand for a working medium with physical properties that make it difficult for pressure loss to increase.
• One aspect of the present disclosure aims to provide a working fluid for a heat cycle in which an increase in pressure loss is suppressed, and a composition for a heat cycle system using the same.
• a working fluid for heat cycle comprising trifluoroethylene, 1,1-difluoroethane, and trifluoroiodomethane
• the ratio of 1,1-difluoroethane to the total of trifluoroethylene and 1,1-difluoroethane is 57.5 mass% or less
• the ratio of trifluoroiodomethane to the total of trifluoroethylene, 1,1-difluoroethane, and trifluoroiodomethane is 24.5 mass% or less
• the total ratio of trifluoroethylene, 1,1-difluoroethane and trifluoroiodomethane to the entire working fluid for heat cycle is 75.0% by mass or more;
• Working medium for heat cycles comprising trifluoroethylene, 1,1-difluoroethane, and trifluoroiodomethane
• ⁇ 2> The working fluid for heat cycle according to ⁇ 1>, wherein a ratio of 1,1-difluoroethane to a total of trifluoroethylene and 1,1-difluoroethane is 23.0 mass% or less.
• ⁇ 3> The working fluid for heat cycle according to ⁇ 1>, wherein a ratio of 1,1-difluoroethane to a total of trifluoroethylene and 1,1-difluoroethane is 11.9 mass% or less.
• ⁇ 4> The working fluid for heat cycle according to any one of ⁇ 1> to ⁇ 3>, wherein a ratio of trifluoroiodomethane to a total of trifluoroethylene, 1,1-difluoroethane and trifluoroiodomethane is 19.0 mass% or less.
• ⁇ 5> The working fluid for heat cycle according to any one of ⁇ 1> to ⁇ 4>, wherein the working fluid for heat cycle has a global warming potential of 150 or less.
• ⁇ 6> The working fluid for heat cycle according to any one of ⁇ 1> to ⁇ 5>, wherein the working fluid for heat cycle has a combustion heat quantity of 15,000 MJ/kg or less.
• ⁇ 7> The working fluid for a heat cycle according to any one of ⁇ 1> to ⁇ 6>, wherein a temperature gradient, which is a difference between an evaporation start temperature and an evaporation completion temperature in an evaporator, when the working fluid for a heat cycle is applied to a reference refrigeration cycle having an evaporation temperature of 5°C, a condensation temperature of 40°C, a degree of subcooling (SC) of 5°C, a degree of superheat (SH) of 5°C, and a compressor efficiency of 0.7, is 7.0°C or less.
• a composition for a heat cycle system comprising the working fluid for a heat cycle according to any one of ⁇ 1> to ⁇ 7>.
• a working fluid for a heat cycle in which an increase in pressure loss is suppressed, and a composition for a heat cycle system using the same.
• FIG. 1 is a schematic diagram illustrating a refrigeration cycle system as an example of a heat cycle system according to an embodiment of the present disclosure.
• 2 is a cycle diagram showing the state change of the working fluid for the heat cycle in the refrigeration cycle system of FIG. 1 on a pressure-enthalpy diagram.
• each component may contain multiple types of the corresponding substance.
• the ratio of each component means the total ratio of the multiple substances present in the composition, unless otherwise specified.
• the GWP of the working fluid is the 100-year value from the Intergovernmental Panel on climate Change (IPCC) Sixth Assessment Report.
• the GWP of a mixture is the weighted average by composition mass.
• the combustion heat quantity of the working fluid is a theoretical value obtained by converting the value of the combustion heat quantity obtained by stoichiometrically completely combusting 1 mol of the working fluid with oxygen into the value of the combustion heat quantity per 1 kg of the working fluid, and is calculated under the following assumptions.
• the product and reactant compounds are assumed to be gases.
• the products of combustion, which are compounds produced, are HF(g), CO2 (g), COF2 (g) and H2O (g), and if iodine is part of the molecular structure of the substance, I2 (g) is added as a combustion product.
• each compound contained in the working fluid is decomposed into the atoms constituting each compound, and a virtual substance containing each atom is set in consideration of the molar ratio in the working fluid.
• the combustion heat is calculated using the combustion reaction formula of the virtual substance.
• C q H r F s corresponds to the virtual substance.
• a combustion reaction formula is defined by the magnitude of the number of H atoms (r) and the number of F atoms (s) in a substance, and the following formula is used as the combustion reaction formula when the number of H atoms (r) ⁇ the number of F atoms (s).
• a working fluid for heat cycle in one embodiment of the present disclosure contains trifluoroethylene (HFO-1123), 1,1-difluoroethane (HFC-152a), and trifluoroiodomethane (CF 3 I), in which the ratio of HFC-152a to the total of HFO-1123 and HFC-152a is 57.5 mass% or less, the ratio of CF 3 I to the total of HFO-1123, HFC-152a, and CF 3 I is 24.5 mass% or less, and the total ratio of HFO-1123, HFC-152a, and CF 3 I to the entire working fluid for heat cycle is 75.0 mass% or more.
• HFO-1123 trifluoroethylene
• HFC-152a 1,1-difluoroethane
• CF 3 I trifluoroiodomethane
• the working fluid for heat cycle will also be simply referred to as the "working fluid”.
• the ratio to the total of HFO-1123 and HFC-152a will also be referred to as the "two-component ratio”
• the ratio to the total of HFO-1123, HFC-152a, and CF 3 I will also be referred to as the “ternary component ratio”
• the ratio to the entire working fluid will also be referred to as the "medium ratio”.
• the ratio of the total of HFO-1123, HFC-152a, and CF 3 I to the medium is within the above range, and the ratio of HFC-152a to the two-component and the ratio of CF 3 I to the three-component are each within the above range, so that an increase in pressure loss is suppressed.
• the ratio of the total of HFO-1123, HFC-152a, and CF 3 I to the medium, the ratio of HFC-152a to the two-component, and the ratio of CF 3 I to the three-component are each within the above range, so that the relative pressure loss RdP R410A obtained by the method described below can be set to 1.50 or less.
• the working fluid of this embodiment is useful as a substitute for R410A, which has been widely used in air conditioners and the like. As described above, R410A has high cycle performance but high GWP. Therefore, there is a demand for an alternative working fluid having high cycle performance and low GWP.
• Cycle performance is the performance required when applying a working medium to a thermal cycle system, and is evaluated by the coefficient of performance and capacity per unit volume.
• the capacity is the refrigeration capacity, which is the output of the refrigeration cycle system.
• the coefficient of performance is the value obtained by dividing the output (kW) by the power (kW) consumed to obtain that output, and corresponds to the energy consumption efficiency. In other words, the coefficient of performance is the capacity per kW of power consumption. The higher the coefficient of performance, the greater the output can be obtained with a smaller input.
• the capacity per unit volume is also referred to as "CAP”
• COP the coefficient of performance
• HFO-1123 has a low GWP and a high CAP in terms of cycle performance, but there is room for improvement in COP.
• HFC-152a is a compound that has a relatively low GWP and a high COP, so it is expected to improve the COP.
• HFC-152a has a higher flammability than HFO-1123.
• a working fluid containing a highly flammable compound low flammability is required from the viewpoint of safety not only in the initial composition, which is the composition at the time of mixing, but also in the leaked composition, which is the composition after volatilization and leakage during transportation, etc. Therefore, in a working fluid which is a mixture of a highly flammable compound and a less flammable compound, when the most flammable compound in the mixture is compound A, it is preferable that the working fluid satisfies 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, which is less flammable than compound A and has a lower boiling point than compound A, and compound C, which is less flammable than compound A and has a higher boiling point than compound A. Since a working fluid that satisfies the above condition 1 or condition 2 contains compound C, which is less flammable than compound A and has a higher boiling point than compound A, even if evaporation and leakage occur during transportation, etc., compound C is likely to be concentrated and compound A is unlikely to be concentrated because the boiling points of compound A or compound B are lower than compound C. Therefore, it is only necessary to consider the flammability of the initial composition, and it becomes easy to select the composition of the working fluid, which is a mixture.
• CF 3 I which has a boiling point of -22°C, is used as a compound that is less flammable and has a higher boiling point than HFC-152a.
• CF 3 I is a compound that has a low GWP, an extremely low ozone depletion potential, and a low heat of combustion.
• the working fluid of this embodiment can suppress the impact on the ozone layer, satisfy the above condition 2, and suppress the heat of combustion while taking advantage of the low GWP and high CAP of HFO-1123 and the high COP of HFC-152a.
• the working fluid may have physical properties that tend to increase pressure loss depending on the composition.
• the working fluid of this embodiment has physical properties that suppress an increase in pressure loss because the ratio of the total of HFO-1123, HFC-152a, and CF 3 I to the medium is within the above-mentioned range as described above, and the ratios of HFC-152a to the two-component and CF 3 I to the ternary component are each within the above-mentioned range as described above.
• the ratio of HFC-152a to the binary component is 57.5% by mass or less, and the ratio of CF 3 I to the ternary component is 24.5% by mass or less.
• the ratio of HFC-152a to the two components is 57.5% by mass or less as described above, and from the viewpoint of reducing the temperature gradient of the evaporator described below, it is preferably 23.0% by mass or less, and more preferably 11.9% by mass or less.
• the ratio of HFC-152a to the two components is 23.0% by mass or less, it is possible to achieve a temperature gradient of the evaporator determined by the method described below of 7.0° C. or less.
• the ratio of HFC-152a to the two components is 11.9% by mass or less, it is possible to achieve a temperature gradient of the evaporator determined by the method described below of 5.0° C. or less.
• the ratio of HFC-152a to the two components is preferably 2.0% by mass or more, more preferably 3.0% by mass or more, and even more preferably 5.0% by mass or more, from the viewpoint of improving the COP of the working fluid.
• the ratio of CF 3 I to the three components is 24.5 mass % or less as described above, and from the viewpoint of suppressing an increase in pressure loss, it is preferably 19.0 mass % or less, more preferably 15.0 mass % or less.
• the ratio of CF 3 I to the three components is preferably 5 mass % or more, and more preferably 10 mass % or more, from the viewpoint of reducing flammability.
• the ratio of HFC-152a to the three components is preferably 1.5% by mass or more, more preferably 4.0% by mass or more, and even more preferably 5.0% by mass or more from the viewpoint of improving the COP of the working fluid.
• the ratio of HFC-152a to the three components is preferably 54.6% by mass or less, more preferably 50.0% by mass or less, and even more preferably 45.0% by mass or less from the viewpoint of reducing flammability.
• the ratio of HFO-1123 to the three components is preferably 32.1 mass% or more, more preferably 35.0 mass% or more, and even more preferably 40.0 mass% or more, from the viewpoint of improving the CAP of the working fluid.
• the ratio of HFO-1123 to the three components is preferably 93.1 mass% or less, more preferably 90.0 mass% or less, and even more preferably 85.0 mass% or less, from the viewpoint of improving the COP of the working fluid.
• the working fluid of the present disclosure may contain, as necessary, in addition to HFO-1123, HFC-152a, and CF 3 I, compounds that are optional components normally used as working fluids.
• the total ratio of HFO-1123, HFC-152a, and CF 3 I to the medium is 75.0 mass% or more, preferably 80.0 mass% or more, more preferably 90.0 mass% or more, and even more preferably 95.0 mass% or more.
• the ratio of HFC-152a to the two-component component is 57.5 mass% or less and the ratio of CF 3 I to the three-component component is 24.5 mass% or less, whereby the relative pressure loss RdP R410A described below can be made 1.50 or less.
• the total ratio to the medium be 75.0 mass % or more, it becomes easier to achieve both a high CAP and a high COP while suppressing the impact on the ozone layer, reducing GWP, and reducing the amount of heat of combustion.
• HFCs other than HFC-152a HFOs other than HFO-1123 and HFO-1234ze(E), and other components that vaporize or liquefy together with HFO-1123.
• Optional HFCs include trifluoroethane, 1,1,2,2-tetrafluoroethane (HFC-134), pentafluoropropane, hexafluoropropane, heptafluoropropane, pentafluorobutane, heptafluorocyclopentane, etc.
• Optional HFOs 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.
• Optional components other than the above HFCs and HFOs include hydrocarbons such as propylene, cyclopropane, butane, isobutane, pentane, and isopentane; chlorofluoroolefins (CFOs) such as 1,1-dichloro-2,3,3,3-tetrafluoropropene (CFO-1214ya), 1,3-dichloro-1,2,3,3-tetrafluoropropene (CFO-1214yb), and 1,2-dichloro-1,2-difluoroethylene (CFO-1112); and hydrochlorofluoroolefins (HCFOs) such as 1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd) and 1-chloro-1,2-difluoroethylene (HCFO-1122).
• CFOs chlorofluoroolefins
• HCFOs hydrochlorofluoroolefins
• the working fluid of the present disclosure is substantially free of any component having a heat of combustion (HOC) of 16.600 MJ/kg or more as a simple substance.
• HOC heat of combustion
• the ratio of any component having a heat of combustion of 16.600 MJ/kg or more as a simple substance to the fluid is preferably 1% by mass or less, more preferably 0.5% by mass or less, and even more preferably 0.1% by mass or less.
• An example of an optional component having a heat of combustion of 16.600 MJ/kg or more as a simple substance is fluoroethane (HFC-161).
• the working fluid of the present disclosure is substantially free of any component having a GWP of more than 150 as a simple substance.
• the ratio of any component having a GWP of more than 150 as a simple substance to the fluid is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 1% by mass or less, particularly preferably 0.5% by mass or less, and extremely preferably 0.1% by mass or less.
• An example of an optional component having a GWP of more than 150 as a simple substance is difluoromethane (HFC-32).
• the ratio of CF 3 I to the medium is preferably 24.5 mass % or less, more preferably 19.0 mass % or less, and more preferably 15.0 mass % or less from the viewpoint of suppressing an increase in pressure loss. Also, the ratio of CF 3 I to the medium is preferably 5 mass % or more, and more preferably 10 mass % or more from the viewpoint of reducing flammability.
• the ratio of HFC-152a to the medium is preferably 1.5% by mass or more, more preferably 4.0% by mass or more, and even more preferably 5.0% by mass or more from the viewpoint of improving the COP of the working fluid.
• the ratio of HFC-152a to the medium is preferably 54.6% by mass or less, more preferably 50.0% by mass or less, and even more preferably 45.0% by mass or less from the viewpoint of reducing flammability.
• the ratio of HFO-1123 to the medium is preferably 32.1 mass% or more, more preferably 35.0 mass% or more, and even more preferably 40.0 mass% or more, from the viewpoint of improving the CAP of the working fluid.
• the ratio of HFO-1123 to the medium is preferably 93.1 mass% or less, more preferably 90.0 mass% or less, and even more preferably 85.0 mass% or less, from the viewpoint of improving the COP of the working fluid.
• the GWP of the working fluid is preferably 150 or less, more preferably 100 or less, further preferably 50 or less, and particularly preferably 25 or less.
• the heat of combustion (HOC) of the working fluid is preferably 15,000 MJ/kg or less, more preferably 13,000 MJ/kg or less, further preferably 11,000 MJ/kg or less, and particularly preferably 10,000 MJ/kg or less.
• the working medium of the present disclosure is a mixture of compounds with widely different boiling points and therefore has a temperature gradient.
• the temperature gradient is an index value that measures the usability of the mixture as a working fluid, and is defined as the property that the start temperature and the end temperature of evaporation in a heat exchanger, for example, an evaporator, or condensation in a condenser, are different, and is also called "temperature glide.”
• the temperature gradient is zero, and in a pseudo-azeotropic mixture such as R410A, the temperature gradient is extremely close to zero.
• the temperature gradient of the working medium is large, for example, the inlet temperature of the evaporator may decrease, which may increase the possibility of frost formation.
• the working medium flowing through the heat exchanger counterflow with the heat source fluid, such as water or air, in order to improve the heat exchange efficiency.
• the temperature difference between the heat source fluid is small. Therefore, if the temperature gradient of the working medium is large, it is difficult to obtain a heat cycle system with good energy efficiency. For this reason, a working medium with a small temperature gradient is desired.
• the temperature gradient (TG) expressed by the difference between the start temperature and the end temperature of evaporation in the evaporator is preferably 7.0°C or less, more preferably 6.5°C or less, even more preferably 6.0°C or less, and particularly preferably 5.0°C or less.
• the evaporation temperature is the average temperature of the evaporation start temperature and the evaporation end temperature
• the condensation temperature is the average temperature of the condensation start temperature and the condensation end temperature.
• the temperature gradient indicated by the difference between the evaporation start temperature and the evaporation end temperature in the evaporator when the working medium is applied to a reference refrigeration cycle with the evaporation temperature of 5°C, the condensation temperature of 40°C, the degree of supercooling (SC) of 5°C, the degree of superheat (SH) of 5°C, and the compressor efficiency of 0.7 is also referred to as the "temperature gradient of the evaporator".
• the temperature gradient of the evaporator is a value calculated as the difference between the evaporation start temperature and the evaporation completion temperature in the evaporator, and is a value measured using a standard refrigeration cycle adopting the following temperature conditions in a refrigeration cycle system described later.
• the temperature gradient in the working medium in the evaporator varies depending on the mixture ratio of HFO-1123, HFC-152a and CF 3 I.
• the relative refrigeration capacity RCAP R410A of the working fluid of the present disclosure to R410A is preferably 0.67 or more, more preferably 0.70 or more, and even more preferably 0.75 or more.
• the relative refrigeration capacity RCAP R410A is a value expressed by CAP A /CAP R410A , where CAP R410A is the refrigeration capacity of R410A and CAP A is the refrigeration capacity of the working fluid of the present disclosure.
• the refrigeration capacity CAP is the refrigeration capacity per unit volume of the evaporator, and is calculated as the product of the compressor intake saturation gas density and the latent heat of evaporation.
• the refrigeration capacity CAP is a value calculated by a method described later using the above-mentioned standard refrigeration cycle.
• the product of the CAP which is the refrigeration capacity per unit volume, and the volumetric flow rate corresponds to the output Q (kW) of the cycle system.
• the relative refrigeration capacity to R410A is shown.
• the relative coefficient of performance RCOP R410A of the working fluid of the present disclosure to R410A is preferably 0.96 or more, more preferably 0.97 or more, and even more preferably 0.98 or more.
• the relative coefficient of performance RCOP R410A is a value expressed as COP A /COP R410A , where COP R410A is the coefficient of performance of R410A and COP A is the coefficient of performance of the working fluid of the present disclosure.
• the coefficient of performance (COP) is a value obtained by dividing the output Q (kW) by the power P (kW) consumed to obtain the output Q (kW), and corresponds to the energy consumption efficiency. The higher the COP value, the greater the output can be obtained with a smaller input.
• the coefficient of performance (COP) is a value obtained by using the above-mentioned standard refrigeration cycle and a formula that takes into account the compressor efficiency among the methods described below. In this disclosure, the relative coefficient of performance (COP) to R410A is shown.
• the relative pressure loss RdP R410A of the working fluid of the present disclosure relative to R410A is preferably 1.5 or less, more preferably 1.43 or less, and even more preferably 1.4 or less.
• the relative pressure loss RdP R410A is a value expressed as dP A /dP R410A , where dP R410A is the pressure loss when R410A passes through a certain path, and dP A is the pressure loss when the working fluid of the present disclosure passes through the same path.
• pressure loss is a factor that increases the condensation pressure in the refrigeration cycle and decreases the evaporation pressure, thereby decreasing performance.
• the pressure loss ⁇ P loss is caused by friction in the flow inside the condenser, evaporator, and connecting pipes in the refrigeration cycle, and is expressed by the following formula (13) using the friction coefficient f(-), length L(m), diameter d(m), evaporator capacity ⁇ 0 (kW), latent heat of evaporation W r (kJ/kg), and specific volume ⁇ s (m 3 /kg).
• the evaporator capacity ⁇ 0 (kW) corresponds to the above-mentioned output Q (kW).
• the value in the parentheses in the first half of the equation is determined by the dimensions and performance specifications of the components that make up the refrigeration cycle.
• the value in the second half of the parentheses is determined by the thermal properties of the refrigerant, so when the equipment specifications and performance are the same, the value in the second half of the parentheses should be taken into consideration. Therefore, the pressure loss decreases as the specific volume of the refrigerant decreases and the latent heat of vaporization increases, and increases as the specific volume of the refrigerant increases and the latent heat of vaporization decreases. The smaller the pressure loss, the smaller the work loss, and therefore the better the equipment performance. In this disclosure, the pressure loss is shown in parentheses in the latter half of the formula, and is shown as the relative pressure loss RdP R410A relative to R410A.
• composition for heat cycle systems contains the above-mentioned working fluid for a heat cycle, and may contain other components as necessary.
• the working fluid for heat cycle described above can be mixed with a refrigerating machine oil and used as the composition for heat cycle system of the present embodiment.
• the composition for heat cycle system of the present embodiment containing the working fluid for heat cycle described above and a refrigerating machine oil may further contain known additives such as stabilizers and leak detection substances in addition to the above.
• refrigeration oil any known refrigerating machine oil that has been used in a heat cycle system composition, together with a working fluid made of halogenated hydrocarbon, can be used without any particular limitation.
• the refrigerating machine oil include oxygen-containing synthetic oils (ester-based refrigerating machine oils, ether-based refrigerating machine oils, etc.), fluorine-based refrigerating machine oils, mineral-based refrigerating machine oils, and hydrocarbon-based synthetic oils.
• ester-based refrigeration oils examples include dibasic acid ester oil, polyol ester oil, complex ester oil, polyol carbonate ester oil, etc.
• Preferred dibasic acid ester oils are esters of dibasic acids having 5 to 10 carbon atoms (glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, etc.) with monohydric alcohols having 1 to 15 carbon atoms and linear or branched alkyl groups (methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, etc.).
• dibasic acid ester oils include ditridecyl glutarate, di(2-ethylhexyl) adipate, diisodecyl adipate, ditridecyl adipate, and di(3-ethylhexyl) sebacate.
• esters of diols 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.
• polyols having 3 to 20 hydroxyl groups trimethylolethane, trimethylolpropane, trimethylolbutane, pentaerythritol, glycerin, sorbitol, sorbitan, sorbitol glycerin condensates, etc.
• fatty acids having 6 to 20 carbon atoms straight-chain or branched fatty acids such as hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecano
• Preferred polyol ester oils are esters of hindered alcohols (neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, pentaerythritol, etc.) (trimethylolpropane tripelargonate, pentaerythritol 2-ethylhexanoate, pentaerythritol tetrapelargonate, etc.).
• hindered alcohols neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, pentaerythritol, etc.
• Complex ester oils are esters of fatty acids and dibasic acids with monohydric alcohols and polyols.
• the fatty acids, dibasic acids, monohydric alcohols, and polyols used are the same as those described above.
• Polyol carbonate ester oil is an ester of carbonic acid and a polyol.
• polyols include the same diols and polyols as described above.
• the polyol carbonate ester oil may be a ring-opening polymer of a cyclic alkylene carbonate.
• Ether-based refrigeration oils include polyvinyl ether oil and polyoxyalkylene oil.
• Polyvinyl ether oils include those obtained by polymerizing vinyl ether monomers such as alkyl vinyl ethers, and copolymers obtained by copolymerizing vinyl ether monomers with hydrocarbon monomers having olefinic double bonds.
• the vinyl ether monomer may be used alone or in combination of two or more types.
• Hydrocarbon monomers having an olefinic double bond include ethylene, propylene, various butenes, various pentenes, various hexenes, various heptenes, various octenes, diisobutylene, triisobutylene, styrene, ⁇ -methylstyrene, various alkyl-substituted styrenes, etc. Hydrocarbon monomers having an olefinic double bond may be used alone or in combination of two or more.
• the polyvinyl ether copolymer may be either a block or random copolymer.
• the polyvinyl ether oil may be used alone or in combination of two or more kinds.
• polyoxyalkylene oils include polyoxyalkylene monools, polyoxyalkylene polyols, alkyl ethers of polyoxyalkylene monools and polyoxyalkylene polyols, and esters of polyoxyalkylene monools and polyoxyalkylene polyols.
• Polyoxyalkylene monools and polyoxyalkylene polyols can be 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.) with an initiator such as water or a hydroxyl group-containing compound in the presence of a catalyst such as an alkali hydroxide.
• the oxyalkylene units in the polyalkylene chain may be the same in one molecule, or two or more types of oxyalkylene units may be contained. It is preferable that one molecule contains at least an oxypropylene unit.
• Initiators used in the reaction include water, monohydric alcohols such as methanol and butanol, and polyhydric alcohols such as ethylene glycol, propylene glycol, pentaerythritol, and glycerol.
• alkyl ethers or esters of polyoxyalkylene monools or polyoxyalkylene polyols are preferred.
• polyoxyalkylene polyols polyalkylene glycols are preferred.
• alkyl ethers of polyalkylene glycols called polyglycol oils, in which the terminal hydroxyl groups of polyalkylene glycols are capped with alkyl groups such as methyl groups, are preferred.
• fluorine-based refrigeration oils include compounds in which the hydrogen atoms of synthetic oils (such as mineral oils, poly- ⁇ -olefins, alkylbenzenes, and alkylnaphthalenes, which will be described later) are replaced with fluorine atoms, perfluoropolyether oils, and fluorinated silicone oils.
• synthetic oils such as mineral oils, poly- ⁇ -olefins, alkylbenzenes, and alkylnaphthalenes, which will be described later
• fluorine atoms such as mineral oils, poly- ⁇ -olefins, alkylbenzenes, and alkylnaphthalenes, which will be described later
• mineral refrigeration oils examples include paraffinic mineral oils and naphthenic mineral oils, which are refined by appropriately combining refining processes (solvent deasphalting, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, clay processing, etc.) from the refrigeration oil fraction obtained by atmospheric or reduced pressure distillation of crude oil.
• Examples of synthetic hydrocarbon oils include poly- ⁇ -olefins, alkylbenzenes, and alkylnaphthalenes.
• Refrigeration oils may be used alone or in combination of two or more types.
• refrigeration oil one or more types selected from polyol ester oil, polyvinyl ether oil, and polyglycol oil are preferred in terms of compatibility with the heat cycle working medium.
• the amount of refrigerating machine oil contained in the composition for heat cycle systems may be within a range that does not significantly reduce the effects of the present invention, and 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, per 100 parts by mass of the working fluid for heat cycle systems.
• the stabilizer optionally contained in the composition for heat cycle systems is a component that improves the stability of the working fluid for heat cycle systems against heat and oxidation.
• known stabilizers that have been used in heat cycle systems together with working fluids made of halogenated hydrocarbons such as oxidation resistance improvers, heat resistance improvers, metal deactivators, etc., can be used without any particular restrictions.
• oxidation resistance improvers and heat resistance improvers examples include N,N'-diphenylphenylenediamine, 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-(t-butyl)phenol, 2,6-di-(t-butyl)phenol, 4-methyl-2,6-di-(t-butyl)phenol, 4,4'-methylenebis(2,6-di-t-butylphenol), etc.
• the oxidation resistance improvers and heat resistance improvers may be used alone or in combination of two or more.
• Metal deactivators include imidazole, benzimidazole, 2-mercaptobenzthiazole, 2,5-dimethylcaptothiadiazole, salicylidin-propylenediamine, pyrazole, benzotriazole, tolutriazole, 2-methylbenzamidazole, 3,5-dimethylpyrazole, methylenebis-benzotriazole, organic acids or their esters, primary, secondary or tertiary aliphatic amines, amine salts of organic or inorganic acids, heterocyclic nitrogen-containing compounds, amine salts of alkyl acid phosphates or their derivatives, etc.
• the content of the stabilizer in the composition for heat cycle systems may be within a range that does not significantly reduce the effects of the present invention, and is preferably 5 parts by mass or less, and more preferably 1 part by mass or less, per 100 parts by mass of the working fluid for heat cycle systems.
• Leak detection substances that may be optionally contained in the composition for heat cycle systems include ultraviolet fluorescent dyes, odorous gas and odor masking agents, etc.
• ultraviolet fluorescent dyes include known ultraviolet fluorescent dyes that have been used in heat cycle systems together with working fluids made of halogenated hydrocarbons, such as those described in U.S. Pat. No. 4,249,412, JP-T-10-502737, JP-T-2007-511645, JP-T-2008-500437, and JP-T-2008-531836.
• odor masking agents include known fragrances that have been used in heat cycle systems together with working fluids made of halogenated hydrocarbons, such as those described in JP-T-2008-500437 and JP-T-2008-531836.
• a solubilizer When using a leak detection substance, a solubilizer may be used to improve the solubility of the leak detection substance in the heat cycle working fluid.
• Solubilizers include those described in JP-T-2007-511645, JP-T-2008-500437, and JP-T-2008-531836.
• the content of the leak detection substance in the composition for heat cycle systems may be within a range that does not significantly reduce the effects of the present invention, and is preferably 2 parts by mass or less, and more preferably 0.5 parts by mass or less, per 100 parts by mass of the working fluid for heat cycle systems.
• the heat cycle system according to an embodiment of the present disclosure is a system using the composition for a heat cycle system described above.
• the heat cycle system according to the present embodiment may be a heat pump system that utilizes hot heat obtained in a condenser, or a refrigeration cycle system that utilizes cold heat obtained in an evaporator.
• thermal cycle system of this embodiment include refrigeration and freezing equipment, air conditioning equipment, power generation systems, heat transport devices, and secondary cooling machines.
• the thermal cycle system of this embodiment is preferably used as air conditioning equipment, which is often installed outdoors, because it can stably and safely exert thermal cycle performance even in higher temperature operating environments.
• the thermal cycle system of this embodiment is also preferably used as refrigeration and freezing equipment.
• air-conditioning equipment examples include household air conditioners (room air conditioners, housing air conditioners, etc.), commercial air conditioners (package air conditioners for stores, package air conditioners for buildings, package air conditioners for facilities, etc.), gas engine heat pumps, train air conditioners, and automobile air conditioners.
• the automotive air conditioner is preferably an air conditioner for a gasoline vehicle, an air conditioner for a hybrid vehicle, an air conditioner for an electric vehicle, or an air conditioner for a hydrogen vehicle, and more preferably an air conditioner for an electric vehicle.
• freezing and refrigeration equipment include showcases (built-in showcases, separate showcases, etc.), commercial freezers and refrigerators, vending machines, ice makers, etc.
• the preferred power generation system is a Rankine cycle system.
• a specific example of a power generation system is one in which a working medium is heated in an evaporator using geothermal energy, solar heat, or waste heat in the medium to high temperature range of 50°C to 200°C, and the working medium that has become steam in a high-temperature, high-pressure state is adiabatically expanded in an expander, and the work generated by this adiabatic expansion drives a generator to generate electricity.
• a latent heat transport device As the heat transport device, a latent heat transport device is preferred.
• latent heat transport devices include heat pipes and two-phase closed thermosiphon devices that transport latent heat by utilizing phenomena such as evaporation, boiling, and condensation of the working medium enclosed within the device.
• Heat pipes are used in relatively small cooling devices, such as cooling devices for heat-generating parts of semiconductor elements and electronic devices.
• Two-phase closed thermosiphon devices do not require a wig and have a simple structure, so they are widely used in gas-gas type heat exchangers, for promoting snow melting and preventing freezing on roads, etc.
• FIG. 1 is a schematic diagram showing a refrigeration cycle system, which is an example of a heat cycle system according to this embodiment. Below, a method for determining the refrigeration capacity and coefficient of performance of a specified heat cycle working medium using the refrigeration cycle system shown in FIG. 1 will be described.
• the refrigeration cycle system 10 includes a compressor 11 that compresses vapor A of a heat cycle working medium to produce vapor B of a high-temperature, high-pressure heat cycle working medium, a condenser 12 that cools and liquefies the vapor B of the heat cycle working medium discharged from the compressor 11 to produce low-temperature, high-pressure heat cycle working medium C, an expansion valve 13 that expands the heat cycle working medium C discharged from the condenser 12 to produce low-temperature, low-pressure heat cycle working medium D, an evaporator 14 that heats the heat cycle working medium D discharged from the expansion valve 13 to produce vapor A of a high-temperature, low-pressure heat cycle working medium, 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.
• a compressor 11 that compresses vapor A of a heat cycle working medium to produce vapor B of a high-temperature, high-pressure heat cycle working medium
• the vapor A of the heat cycle working fluid discharged from the evaporator 14 is compressed by the compressor 11 to produce the vapor B of the high-temperature and high-pressure heat cycle working fluid.
• this will be referred to as the "AB process.”
• the vapor B of the heat cycle working fluid discharged from the compressor 11 is cooled by the fluid F in the condenser 12 and liquefied to produce a low-temperature, high-pressure heat cycle working fluid C. During this process, the fluid F is heated to become a fluid F', which is discharged from the condenser 12.
• the refrigeration cycle system 10 is a cycle system consisting of adiabatic/isentropic changes, isenthalpic changes, and isobaric changes.
• Figure 2 is a cycle diagram showing the state changes of the working medium for the heat cycle in the refrigeration cycle system 10 of Figure 1 on a pressure-enthalpy diagram.
• the state changes of the working medium for the heat cycle are plotted on the pressure-enthalpy line (curve) diagram shown in Figure 2, they are represented as a trapezoid with vertices A, B, C, and D.
• the AB process is a process in which adiabatic compression is performed in the compressor 11 to convert high-temperature, low-pressure heat cycle working fluid vapor A into high-temperature, high-pressure heat cycle working fluid vapor B, and is shown by line AB in Figure 2.
• heat cycle working fluid vapor A is introduced into the compressor 11 in a superheated state, and the resulting heat cycle working fluid vapor B is also superheated vapor.
• the compressor intake gas density is the density ( ⁇ s) in state A in Figure 2.
• the compressor discharge gas pressure (discharge pressure) is the pressure (Px) in state B in Figure 2, which is the maximum pressure in the refrigeration cycle. Note that since the BC process is isobaric cooling, the discharge pressure has the same value as the condensation pressure (Pc). Therefore, for convenience, the condensation pressure is shown as Px in Figure 2.
• the BC process is a process in which isobaric cooling is performed in the condenser 12 to convert high-temperature, high-pressure heat cycle working fluid vapor B into low-temperature, high-pressure heat cycle working fluid C, and is shown by the BC line in Figure 2.
• the pressure at this time is the condensation pressure.
• the intersection T1 on the high enthalpy side is the condensation temperature
• the intersection T2 on the low enthalpy side is the condensation boiling point temperature.
• the temperature gradient of the condenser is shown as the difference between T1 and T2 .
• the CD process is a process in which isenthalpic expansion is performed in the expansion valve 13 to convert the low-temperature, high-pressure heat cycle working fluid C into a low-temperature, low-pressure heat cycle working fluid D, and is indicated by the line CD in Fig. 2. If the temperature of the low-temperature, high-pressure heat cycle working fluid C is indicated as T3 , then T2 - T3 is the degree of supercooling (SC) of the heat cycle working fluid in the cycles (i) to (iv).
• SC supercooling
• the DA process is a process in which isobaric heating is performed in the evaporator 14 to return the low-temperature, low-pressure heat cycle working medium D to the high-temperature, low-pressure heat cycle working medium vapor A, and is shown by the DA line in FIG. 2.
• the pressure at this time is the evaporation pressure (Py).
• the intersection T6 on the high enthalpy side is the evaporation temperature.
• T7 indicates the temperature of the heat cycle working medium D
• T5 indicates the temperature of the working medium D when the degree of supercooling (SC) is 0.
• the temperature gradient of the evaporator is shown as the difference between T6 and T4 .
• the CAP and COP of the heat cycle working fluid can be calculated from the following formulas (5) to (8) using the enthalpies hA, hB, hC, and hD of the heat cycle working fluid in each state A (after evaporation, high temperature and low pressure), B (after compression, high temperature and high pressure), C (after condensation, low temperature and high pressure), and D (after expansion, low temperature and low pressure), as well as the refrigerant mass circulation amount qmr. Note that there is no pressure loss in the piping or heat exchanger. In addition, in the following formulas (5) to (8), there is no loss of work in the compressor, which will be described later, and compressor efficiency is not taken into account.
• the cycle performance (CAP and COP) of the working fluid for heat cycle is based on the National Institute of Science and Technology (NIST)
• the refrigeration cycle theoretical calculation of the working medium is performed under the above conditions using the Reference Fluid Thermodynamic and Transport Properties Database (REFPROP 10.0).
• REFPROP 10.0 Reference Fluid Thermodynamic and Transport Properties Database
• problems can occur, especially when it is used at low temperatures. For example, problems can occur such as freezing inside the capillary tube, hydrolysis of the heat cycle working medium and refrigeration oil, material deterioration due to acid components generated within the cycle, and generation of contaminants.
• the refrigeration oil is polyglycol oil, polyol ester oil, etc.
• it is highly hygroscopic and prone to hydrolysis reactions, which reduces the properties of the refrigeration oil and is a major cause of impairing the long-term reliability of the compressor. Therefore, in order to suppress hydrolysis of the refrigeration oil, it is necessary to control the moisture concentration in the heat cycle system.
• Methods for controlling the moisture concentration in a heat cycle system include using moisture removal means such as desiccants (silica gel, activated alumina, zeolite, etc.).
• desiccants silicon gel, activated alumina, zeolite, etc.
• Zeolite-based desiccants are preferred as desiccants in terms of the chemical reactivity between the desiccants and the composition for heat cycle systems and the moisture absorption capacity of the desiccants.
• a zeolite-based desiccant whose main component is a compound represented by the following formula (12) is preferred because of its excellent moisture absorption capacity.
• M is a Group 1 element such as Na or K, or a Group 2 element such as Ca
• n is the atomic valence of M
• x and y are values determined by the crystal structure.
• the pore size can be adjusted by changing M.
• pore size and breaking strength are important. If a desiccant with a pore size larger than the molecular size of the heat cycle working fluid contained in the heat cycle system composition is used, the heat cycle working fluid will be adsorbed into the desiccant. As a result, a chemical reaction will occur between the heat cycle working fluid and the desiccant, resulting in undesirable phenomena such as the generation of non-condensable gases, a decrease in the strength of the desiccant, and a decrease in its adsorption capacity.
• a zeolite-based desiccant with a small pore size as the desiccant.
• sodium-potassium A-type synthetic zeolite with a pore size of 3.5 angstroms or less is preferable.
• sodium-potassium A-type synthetic zeolite with a pore size smaller than the molecular size of the heat cycle working fluid it is possible to selectively adsorb and remove only the moisture in the heat cycle system without adsorbing the heat cycle working fluid.
• the heat cycle working fluid is less likely to be adsorbed onto the desiccant, thermal decomposition is less likely to occur, and as a result, deterioration of the materials that make up the heat cycle system and the generation of contaminants can be suppressed.
• the size of the zeolite desiccant is preferably between about 0.5 mm and 5 mm, since if it is too small it can cause clogging of the valves and piping details of the heat cycle system, and if it is too large it reduces the drying capacity.
• the shape of the zeolite desiccant is preferably granular or cylindrical.
• Zeolite-based desiccants can be formed into any shape by solidifying powdered zeolite with a binder (such as bentonite). As long as the main component is a zeolite-based desiccant, other desiccants (such as silica gel or activated alumina) may be used in combination. There are no particular limitations on the ratio of zeolite-based desiccants to the composition for heat cycle systems.
• non-condensable gases get into the heat cycle system, it can have a detrimental effect on the heat transfer in the condenser and evaporator and increase the operating pressure, so it is necessary to prevent their mixing as much as possible.
• oxygen which is one of the non-condensable gases, reacts with the heat cycle working medium and refrigeration oil, promoting their decomposition.
• the concentration of the non-condensable gas in the gas phase of the heat cycle working fluid is preferably 1.5% by volume or less, and more preferably 0.5% by volume or less, in terms of volume ratio to the heat cycle working fluid.
• Examples 1 to 16 are working examples
• Examples 17 to 20 are comparative examples
• Examples 21 to 23 are reference examples.
• Table 1 it can be seen that the relative pressure loss is reduced in Examples 1 to 16 compared to Examples 17 to 20 and 23.
• Examples 1 to 16 have a higher relative coefficient of performance RCOP R410A compared to Example 21, a higher relative refrigeration capacity RCAP R410A , and lower heat of combustion HOC and GWP compared to Example 22.
• the heat cycle system using the heat cycle working fluid and heat cycle system composition disclosed herein can be used in refrigeration and freezing equipment (built-in showcases, separate showcases, commercial freezers and refrigerators, vending machines, ice makers, etc.), air conditioning equipment (room air conditioners, packaged air conditioners for stores, packaged air conditioners for buildings, packaged air conditioners for facilities, gas engine heat pumps, train air conditioners, automotive air conditioners, etc.), power generation systems (waste heat recovery power generation, etc.), heat transport devices (heat pipes, etc.), and secondary cooling machines.
• refrigeration and freezing equipment built-in showcases, separate showcases, commercial freezers and refrigerators, vending machines, ice makers, etc.
• air conditioning equipment room air conditioners, packaged air conditioners for stores, packaged air conditioners for buildings, packaged air conditioners for facilities, gas engine heat pumps, train air conditioners, automotive air conditioners, etc.
• power generation systems waste heat recovery power generation, etc.
• heat transport devices heat pipes, etc.
• secondary cooling machines secondary cooling machines.
• Refrigeration cycle system 11 Compressor 12 Condenser 13 Expansion valve 14 Evaporator 15, 16 Pump

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• 2023
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