Search

EP-4737531-A1 - WORKING MEDIUM FOR REFRIGERATION CYCLE, AND REFRIGERATION CYCLE SYSTEM

EP4737531A1EP 4737531 A1EP4737531 A1EP 4737531A1EP-4737531-A1

Abstract

A refrigeration-cycle working medium includes: as a refrigerant component, fluoroolefin that causes a disproportionation reaction; and as a disproportionation inhibitor that suppresses the disproportionation reaction of the fluoroolefin, hydrofluoroolefin that is different from the fluoroolefin and has three or more carbon atoms. The hydrofluoroolefin may not have a perfluoromethyl group (-CF 3 ) and a perfluoromethylene group (-CF 2 -) in a molecular structure thereof or may have at least one of a methyl group (-CH 3 ), a fluoromethyl group (-CH 2 F), or a difluoromethyl group (-CHF 2 ) in the molecular structure.

Inventors

  • MURAKAMI, HIKARU
  • HASHIMOTO, TAKAHIKO
  • SAKATA, NAOYA
  • TSUNOYAMA, HIRONORI

Assignees

  • Panasonic Intellectual Property Management Co., Ltd.

Dates

Publication Date
20260506
Application Date
20240617

Claims (12)

  1. A refrigeration-cycle working medium comprising: as a refrigerant component, fluoroolefin that causes a disproportionation reaction; and as a disproportionation inhibitor that suppresses the disproportionation reaction of the fluoroolefin, hydrofluoroolefin that is different from the fluoroolefin and has three or more carbon atoms.
  2. The refrigeration-cycle working medium according to claim 1, wherein the hydrofluoroolefin does not have a perfluoromethyl group (-CF 3 ) and a perfluoromethylene group (-CF 2 -) in a molecular structure thereof.
  3. The refrigeration-cycle working medium according to claim 1, wherein the hydrofluoroolefin has at least one of a methyl group (-CH 3 ), a fluoromethyl group (-CH 2 F), or a difluoromethyl group (-CHF 2 ) in a molecular structure thereof.
  4. The refrigeration-cycle working medium according to claim 3, wherein the hydrofluoroolefin has a boiling point of 0°C or less.
  5. The refrigeration-cycle working medium according to any one of claims 1 to 4, wherein the hydrofluoroolefin is 2,3,3-trifluoropropene (HFO1243yf, CF 2 H-CF = CH 2 ), 1,1-difluoropropene (HFO1252zc, CH 3 -CH = CF 2 ), 2-fluoropropene (HFO1261yf, CH 3 -CF = CH 2 ), or 3-fluoropropene (HFO1261zf, CFH 2 -CH = CH 2 ).
  6. The refrigeration-cycle working medium according to any one of claims 1 to 4, wherein the fluoroolefin that causes the disproportionation reaction is 1,1,2-trifluoroethylene or difluoroethylene.
  7. The refrigeration-cycle working medium according to any one of claims 1 to 4, further comprising difluoromethane (R32) as the refrigerant component.
  8. The refrigeration-cycle working medium according to any one of claims 1 to 4, further comprising, when the hydrofluoroolefin is a main disproportionation inhibitor, as the disproportionation inhibitor, a sub-disproportionation inhibitor that is at least one selected from the group consisting of (i) haloalkane that has one or two carbon atoms and is not a compound in which all halogen atoms are fluorine, (ii) fluoroalkane having a boiling point of 0°C or less and having one to three carbon atoms (except for difluoromethane), and (iii) saturated hydrocarbon having two to five carbon atoms.
  9. The refrigeration-cycle working medium according to any one of claims 1 to 4, wherein when a total amount of the refrigerant component and the disproportionation inhibitor is regarded as 100 mass %, the content of the hydrofluoroolefin is 50 mass % or less.
  10. The refrigeration-cycle working medium according to claim 7, wherein when a total amount of the refrigerant component and the disproportionation inhibitor is regarded as 100 mass %, the content of the difluoromethane is 30 mass % or less.
  11. The refrigeration-cycle working medium according to claim 8, wherein when a total amount of the refrigerant component and the disproportionation inhibitor is regarded as 100 mass %, the content of the sub-disproportionation inhibitor is 10 mass % or less.
  12. A refrigeration cycle system configured by using the refrigeration-cycle working medium according to any one of claims 1 to 4.

Description

Technical Field The present invention relates to a refrigeration-cycle working medium that can effectively suppress or weaken a disproportionation reaction of fluoroolefin (fluoroalkene), such as 1,1,2-trifluoroethylene, and a refrigeration cycle system that uses the refrigeration-cycle working medium. Background Art As a refrigeration-cycle working medium (a refrigerant or a heat medium), HCFCs (hydrochlorofluorocarbons) have been used in the past. However, the HCFCs largely influence ozone layer depletion. Therefore, in recent years, HFCs (hydrofluorocarbons) having an ozone depletion potential (ODP) of zero are used. Among such HFCs, the use of fluoroolefin having a lower global warming potential (GWP), especially hydrofluoroolefin (HFO), has been recently proposed. Known as representative HFOs are, for example, 1,1,2-trifluoroethylene (HFO1123) and difluoroethylene (HFO1132). These HFOs are lower in stability than the conventional HFCs and the like. Therefore, the HFOs hardly remain in the atmosphere, and thus, has a low ODP and a low GWP. However, it is also known that since the stability of the HFO is low, a self-polymerization reaction which is called a disproportionation reaction tends to occur (such reaction is hereinafter referred to as the disproportionation reaction). The disproportionation reaction tends to occur by being induced by, for example, heat generated during the use of the refrigeration-cycle working medium. In addition, it is also known that since large heat dissipation is caused by the occurrence of the disproportionation reaction, the disproportionation reactions occur successively. As a result, a large amount of soot is generated, and this may deteriorate the reliability of a refrigeration cycle system or the reliability of a compressor and the like constituting the refrigeration cycle system. Therefore, when, for example, the 1,1,2-trifluoroethylene is used as a refrigerant component of the refrigeration-cycle working medium, the present applicants propose, as a component (disproportionation inhibitor) that suppresses the disproportionation reaction of the 1, 1,2-trifluoroethylene, halomethane (PTL 1), saturated hydrocarbon (PTL 2), haloethane (PTL 3), a combination of these (PTL 4 or 5), and difluoroiodomethane (PTL 6) as a representative example of the especially suitable disproportionation inhibitor. As the refrigerant component that can be used together with the 1,1,2-trifluoroethylene, difluoromethane (HFC32, R32) is also known (R32 is a refrigerant number based on Standard 34 of American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE)). For example, PTLs 1 to 4 disclose that a main refrigerant component is the 1,1,2-trifluoroethylene, but the difluoromethane can be used together. PTLs 5 and 6 disclose that the 1,1,2-trifluoroethylene (or fluoroolefin) and the difluoromethane are used together as the refrigerant components. Citation List Patent Literature PTL 1: Japanese Laid-Open Patent Application Publication No. 2017-145380PTL 2: Japanese Laid-Open Patent Application Publication No. 2018-048271PTL 3: Japanese Laid-Open Patent Application Publication No. 2018-104565PTL 4: Japanese Laid-Open Patent Application Publication No. 2018-104566PTL 5: Japanese Laid-Open Patent Application Publication No. 2019-034983PTL 6: Japanese Laid-Open Patent Application Publication No. 2021-161316 Summary of Invention Technical Problem The above-described disproportionation inhibitor can effectively suppress or weaken the disproportionation reaction of the fluoroolefin, such as the 1,1,2-trifluoroethylene. Moreover, even when the difluoromethane is used together as the refrigerant component, the above-described disproportionation inhibitor can effectively suppress or weaken the disproportionation reaction of the fluoroolefin. In recent years, regarding such refrigeration-cycle working medium, in addition to achieving the effective suppression or weakening of the disproportionation reaction of the fluoroolefin, there is a growing tendency to seek a further reduction in environmental impact. The present invention was made to solve the above problems, and an object of the present invention is to further reduce the environmental impact regarding the refrigeration-cycle working medium which includes the fluoroolefin as the refrigerant component and also includes the disproportionation inhibitor. Solution to Problem The present inventors have diligently studied to solve the above problems. As a result, the present inventors have uniquely found that: the hydrofluoroolefin has been considered to be unable to exhibit suitable performance as the refrigerant component; however, by combining the hydrofluoroolefin with fluoroolefin suitable as the refrigerant component, the disproportionation reaction of the fluoroolefin can be effectively suppressed or weakened, and the environmental impact can be further reduced. Thus, the present invention has been made. To solve the above pro