EP0620838A1 - Compositions useful as refrigerants - Google Patents

Compositions useful as refrigerants

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Publication number
EP0620838A1
EP0620838A1 EP93900353A EP93900353A EP0620838A1 EP 0620838 A1 EP0620838 A1 EP 0620838A1 EP 93900353 A EP93900353 A EP 93900353A EP 93900353 A EP93900353 A EP 93900353A EP 0620838 A1 EP0620838 A1 EP 0620838A1
Authority
EP
European Patent Office
Prior art keywords
weight
difluoromethane
refrigerant
refrigerant composition
trifluoromethyl ether
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
EP93900353A
Other languages
German (de)
French (fr)
Inventor
Richard Llewellyn Powell
James David Morrison
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Imperial Chemical Industries Ltd
Original Assignee
Imperial Chemical Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Imperial Chemical Industries Ltd filed Critical Imperial Chemical Industries Ltd
Publication of EP0620838A1 publication Critical patent/EP0620838A1/en
Ceased legal-status Critical Current

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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
    • 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
    • C09K2205/11—Ethers
    • C09K2205/112—Halogenated ethers
    • 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

Definitions

  • the present invention relates generally to refrigerant compositions for cooling and heating applications and to the use of such compositions in heat transfer devices. More particularly, the present invention is concerned with refrigerant compositions which are designed to replace chlorodifluoromethane (Refrigerant R-22) and the azeotropic mixture of chlorodifluoromethane with chloropentafluoroethane (Refrigerant R-115), the azeotrope being Refrigerant R-502.
  • refrigerant compositions which are designed to replace chlorodifluoromethane (Refrigerant R-22) and the azeotropic mixture of chlorodifluoromethane with chloropentafluoroethane (Refrigerant R-115), the azeotrope being Refrigerant R-502.
  • the properties preferred of a refrigerant include low toxicity, non- flammability, non-corrosivity, high stability and freedom from objectionable odour.
  • heat transfer devices have tended to use fully and partially halogenated chlorofluorocarbon refrigerants such as chlorodifluoromethane (Refrigerant R-22) or the azeotropic mixture of chlorodifluoromethane and chloropentafluoroethane (Refrigerant R-502).
  • chlorofluorocarbon refrigerants such as chlorodifluoromethane (Refrigerant R-22) or the azeotropic mixture of chlorodifluoromethane and chloropentafluoroethane (Refrigerant R-502).
  • the present invention provides a refrigerant composition which may be used in place of Refrigerants R-22 and R-502.
  • the composition contains refrigerant compounds which have essentially zero ozone depletion potentials and comparatively low direct global warming potentials .
  • the present invention provides a refrigerant composition comprising a mixture of difluoromethyl trifluoromethyl ether (CF3OCHF2) and at least one hydrofluoroalkane selected from difluoromethane CH2 2). pentafluoroethane (CF3CHF2) and 1,1 ,1-trifluoroethane (CF3CH 3 ).
  • Refrigerant compositions in accordance with the present invention typically contain from 5 to 952 by weight of difluoromethyl trifluoromethyl ether and from 95 to 5Z by weight of the hydrofluoroalkane component.
  • Suitable refrigerant compositions may contain a single hydrofluoroalkane selected from the three specified compounds or a mixture of any two or all three of the said hydrofluoroalkanes .
  • the refrigerant compositions of the invention may contain other refrigerant compounds which have low and preferably zero ozone depletion potentials, for example other hydrofluoroalkanes and/or other fluorinated ethers containing residual hydrogen atoms.
  • Examples of other hydrofluoroalkanes which may be incorporated in the refrigerant compositions of the invention include 1,1,1, 2-tetrafluoroethane (R-134a ) , 1,1,2,2-tetrafluoroethane (R-134) and 1, 1-difluoroethane (R-152a).
  • Examples of other fluorinated ethers which may be included in the refrigerant compositions of the invention are the fluorinated dimethyl ethers containing residual hydrogen atoms.
  • the refrigerant compositions of the invention may comprise other refrigerant compounds
  • the preferred refrigerant compositions consist essentially of difluoromethyl trifluoromethyl ether and at least one hydrofluoroalkane selected from difluoromethane (R-32), pentafluoroethane (R-125) and 1,1,1-trifluoroethane (R-143a).
  • refrigerant compositions of the invention may be zeotropic they are preferably azeotropic or azeotrope-like.
  • compositions of the invention comprise a mixture of difluoromethyl trifluoromethyl ether and difluoromethane, since such compositions may provide a particularly suitable alternative to Refrigerants R-22 and R-502.
  • Such compositions may additionally comprise one or more further refrigerant compounds, such as pentafluoroethane and/or 1, 1,1-trifluoroethane and/or at least one other fluorinated ether containing residual hydrogen atoms and/or at least one other hydrofluoroalkane.
  • refrigerant compositions are mixtures consisting essentially of difluoromethyl trifluoromethyl ether and di luoromethane, since such compositions, in particular, can exhibit a performance in a heat transfer device which is comparable to Refrigerants R-22 and R-502.
  • Refrigerant compositions according to the invention containing from 20 to 80 Z by weight of difluoromethyl trifluoromethyl ether and from 80 to 20 Z by weight of difluoromethane are preferred as a replacement for Refrigerant R-502.
  • refrigerant compositions of the invention containing from 40 to 80 Z by weight of difluoromethyl trifluoromethyl ether and from 60 to 20 Z by weight of difluoromethane are preferred, with compositions containing from 50 to 75 Z by weight of difluoromethyl trifluoromethyl ether and from 50 to 25 Z by weight of difluoromethane being particularly preferred.
  • An especially preferred refrigerant composition for replacing R-502 contains from 50 to 70 Z by weight of difluoromethyl trifluoromethyl ether and from 50 to 30 Z by weight of difluoromethane.
  • Tables 1 to 3 show the results of analysing the performance of a number of refrigerant compositions of the invention in a low temperature refrigeration cycle to assess the suitability thereof as a replacement for R-502. All the compositions analysed comprised difluoromethyl trifluoromethyl ether (E-125 in the Tables) and difluoromethane (R-32 in the Tables) in varying amounts. The percentage by weight of each component in the refrigerant compositions analysed is given in the second row of the Tables. Thus, the results of analysing the performance of the following refrigerant compositions are given in Tables 1 to 3:
  • a composition comprising 75 Z by weight of difluoromethane and 25 Z by weight of difluoromethyl trifluoromethyl ether.
  • composition comprising 50 Z by weight of difluoromethane and 50 Z by weight of difluoromethyl trifluoromethyl ether.
  • composition comprising 25 Z by weight of difluoromethane and 75 Z by weight of difluoromethyl trifluoromethyl ether.
  • a composition comprising 30 Z by weight of difluoromethane and 70 Z by weight of difluoromethyl trifluoromethyl ether.
  • a composition comprising 35 Z by weight of difluoromethane and 65 Z by weight of difluoromethyl trifluoromethyl ether.
  • Three different sets of operating conditions were used for the analysis. These conditions were as follows :
  • refrigerant compositions according to the invention comprising difluoromethyl trifluoromethyl ether and difluoromethane can exhibit a performance in a low temperature refrigeration system which is comparable to that of Refrigerant R-502. If difluoromethane is used as the sole refrigerant in a refrigeration system, high energy efficiencies and high refrigeration capacities relative to Refrigerant R-502 are obtained, as shown by the values for the coefficient of performance and the cooling duty per unit swept volume of the compressor. However, the discharge temperatures, condenser pressures and evaporator pressures which are obtained with difluoromethane are also high and are not ideal when one is looking for a replacement for Refrigerant * R-502.
  • difluoromethyl trifluoromethyl ether to the difluoromethane provides a means of reducing the discharge temperature, condenser pressure and evaporator pressure while retaining energy efficiencies and refrigeration capacities which are still comparable with and in certain cases superior to R-502. Furthermore, the glide in the evaporator for all the mixed refrigerant compositions tested was 1.4°C or less showing that such compositions are azeotrope like.
  • Refrigerant compositions according to the invention containing from 25 to 99 Z , e.g. 50 to 99 Z, by weight of difluoromethyl trifluoromethyl ether and from 75 to 1 Z, e.g. 50 to 1 Z, by weight of difluoromethane are preferred as a replacement for Refrigerant R-22, particularly in air conditioning applications.
  • a more preferred refrigerant composition for replacing R-22 in air conditioning applications contains from 70 to 90 Z by weight of difluoromethyl trifluoromethyl ether and from 30 to 10 Z by weight of difluoromethane.
  • a particularly preferred refrigerant composition for replacing R-22 in air conditioning applications contains from 75 to 90 Z by weight of difluoromethyl trifluoromethyl ether and from 25 to 10 Z by weight of difluoromethane.
  • Tables 4 and 5 show the results of analysing the performance of a number of refrigerant compositions of the invention in a refrigeration cycle to assess the suitability thereof as a replacement for R-22 in air « conditioning applications. All the compositions
  • a composition comprising 75 Z by weight of difluoromethane and 25 Z by weight of difluoromethyl trifluoromethyl ether.
  • composition comprising 50 Z by weight of difluoromethane and 50 Z by weight of difluoromethyl trifluoromethyl ether.
  • composition comprising 25 Z by weight of difluoromethane and 75 Z by weight of
  • a composition comprising 20 Z by weight of difluoromethane and 80 Z by weight of difluoromethyl trifluoromethyl ether.
  • refrigerant compositions according to the invention comprising difluoromethyl trifluoromethyl ether and difluoromethane can exhibit a performance in an air conditioning system which is similar to that of Refrigerant R-22. It is also evident that refrigerant compositions containing from 75 to 90 Z by weight of difluoromethyl trifluoromethyl ether and from 25 to 10 Z by weight of difluoromethane, especially from 75 • to 85 Z by weight of difluoromethyl trifluoromethyl ether and from 25 to 15 Z by weight of difluoromethane, offer a good alternative to Refrigerant R-22 in air conditioning applications .
  • the refrigerant compositions of the invention may be prepared by a simple mixing process.
  • compositions are useful in all types of compression cycle heat transfer devices.
  • they m_.T be used to provide cooling by a method involving condensing the refrigerant composition and thereafter evaporating it in a heat exchange relationship with a body to be cooled.
  • They may also be used to provide heating by a method involving condensing the refrigerant composition in a heat exchange relationship with a body to be heated and thereafter evaporating it.
  • compositions of the invention provide a good compromise between atmospheric lifetime, ozone depletion, discharge temperature, working pressure and efficiency. They are especially suitable as replacements for R-22 and the R-502 azeotrope. TABLE 1

Abstract

Composition réfrigérante comprenant un mélange d'éther trifluorométhyle difluorométhyle et au moins un hydrofluoroalcane sélectionné à partir de difluorométhane, de pentafluoroéthane et de 1,1,1-trifluoroéthane.Refrigerant composition comprising a mixture of trifluoromethyl difluoromethyl ether and at least one hydrofluoroalkane selected from difluoromethane, pentafluoroethane and 1,1,1-trifluoroethane.

Description

COMPOSITIONS USEFUL AS REFRIGERANTS.
The present invention relates generally to refrigerant compositions for cooling and heating applications and to the use of such compositions in heat transfer devices. More particularly, the present invention is concerned with refrigerant compositions which are designed to replace chlorodifluoromethane (Refrigerant R-22) and the azeotropic mixture of chlorodifluoromethane with chloropentafluoroethane (Refrigerant R-115), the azeotrope being Refrigerant R-502.
Mechanical refrigeration systems and related heat transfer devices such as heat pumps and air-conditioning systems are well known. In such devices, a refrigerant liquid of a suitable boiling point evaporates at low pressure taking heat from a surrounding zone. The resulting vapour is then compressed and passed to a condenser where it condenses and gives off heat to a second zone, the condensate being returned through an expansion valve to the evaporator, so completing the cycle. The mechanical energy required for compressing the vapour and pumping the liquid may be provided by an electric motor or an internal combustion engine.
In addition to having a suitable boiling point and a high latent heat of vaporisation, the properties preferred of a refrigerant include low toxicity, non- flammability, non-corrosivity, high stability and freedom from objectionable odour.
Hitherto, heat transfer devices have tended to use fully and partially halogenated chlorofluorocarbon refrigerants such as chlorodifluoromethane (Refrigerant R-22) or the azeotropic mixture of chlorodifluoromethane and chloropentafluoroethane (Refrigerant R-502).
In recent years, however, there has been increasing international concern that the fully and partially halogenated chlorofluorocarbons may be damaging the earth's protective ozone layer and there is general agreement that their manufacture and use should be severely restricted and eventually phased out completely.
Whilst heat transfer devices of the type to which the present invention relates are essentially closed systems, loss of refrigerant to the atmosphere can occur due to leakage during operation of the equipment or during maintenance procedures. It is important, therefore, to replace fully and partially halogenated chlorofluorocarbon refrigerants by materials having substantially lower, preferably zero, ozone depletion potentials .
In addition to the possibility of ozone depletion, it has been suggested that significant concentrations of chlorofluorocarbon refrigerants in the atmosphere might contribute to global warming (the so-called greenhouse effect). It is desirable, therefore, to use refrigerants which have relatively short atmospheric lifetimes as a result of their ability to react with other atmospheric constituents such as hydroxyl radicals .
The present invention provides a refrigerant composition which may be used in place of Refrigerants R-22 and R-502. The composition contains refrigerant compounds which have essentially zero ozone depletion potentials and comparatively low direct global warming potentials . Accordingly, the present invention provides a refrigerant composition comprising a mixture of difluoromethyl trifluoromethyl ether (CF3OCHF2) and at least one hydrofluoroalkane selected from difluoromethane CH2 2). pentafluoroethane (CF3CHF2) and 1,1 ,1-trifluoroethane (CF3CH3).
Refrigerant compositions in accordance with the present invention typically contain from 5 to 952 by weight of difluoromethyl trifluoromethyl ether and from 95 to 5Z by weight of the hydrofluoroalkane component. Suitable refrigerant compositions may contain a single hydrofluoroalkane selected from the three specified compounds or a mixture of any two or all three of the said hydrofluoroalkanes . Additionally, the refrigerant compositions of the invention may contain other refrigerant compounds which have low and preferably zero ozone depletion potentials, for example other hydrofluoroalkanes and/or other fluorinated ethers containing residual hydrogen atoms. Examples of other hydrofluoroalkanes which may be incorporated in the refrigerant compositions of the invention include 1,1,1, 2-tetrafluoroethane (R-134a ) , 1,1,2,2-tetrafluoroethane (R-134) and 1, 1-difluoroethane (R-152a). Examples of other fluorinated ethers which may be included in the refrigerant compositions of the invention are the fluorinated dimethyl ethers containing residual hydrogen atoms.
Although the refrigerant compositions of the invention may comprise other refrigerant compounds, the preferred refrigerant compositions consist essentially of difluoromethyl trifluoromethyl ether and at least one hydrofluoroalkane selected from difluoromethane (R-32), pentafluoroethane (R-125) and 1,1,1-trifluoroethane (R-143a).
Although the refrigerant compositions of the invention may be zeotropic they are preferably azeotropic or azeotrope-like.
The preferred refrigerant compositions of the invention comprise a mixture of difluoromethyl trifluoromethyl ether and difluoromethane, since such compositions may provide a particularly suitable alternative to Refrigerants R-22 and R-502. Such compositions may additionally comprise one or more further refrigerant compounds, such as pentafluoroethane and/or 1, 1,1-trifluoroethane and/or at least one other fluorinated ether containing residual hydrogen atoms and/or at least one other hydrofluoroalkane. However, particularly preferred refrigerant compositions are mixtures consisting essentially of difluoromethyl trifluoromethyl ether and di luoromethane, since such compositions, in particular, can exhibit a performance in a heat transfer device which is comparable to Refrigerants R-22 and R-502.
Refrigerant compositions according to the invention containing from 20 to 80 Z by weight of difluoromethyl trifluoromethyl ether and from 80 to 20 Z by weight of difluoromethane are preferred as a replacement for Refrigerant R-502. As a R-502 replacement, refrigerant compositions of the invention containing from 40 to 80 Z by weight of difluoromethyl trifluoromethyl ether and from 60 to 20 Z by weight of difluoromethane are preferred, with compositions containing from 50 to 75 Z by weight of difluoromethyl trifluoromethyl ether and from 50 to 25 Z by weight of difluoromethane being particularly preferred. An especially preferred refrigerant composition for replacing R-502 contains from 50 to 70 Z by weight of difluoromethyl trifluoromethyl ether and from 50 to 30 Z by weight of difluoromethane.
Tables 1 to 3 show the results of analysing the performance of a number of refrigerant compositions of the invention in a low temperature refrigeration cycle to assess the suitability thereof as a replacement for R-502. All the compositions analysed comprised difluoromethyl trifluoromethyl ether (E-125 in the Tables) and difluoromethane (R-32 in the Tables) in varying amounts. The percentage by weight of each component in the refrigerant compositions analysed is given in the second row of the Tables. Thus, the results of analysing the performance of the following refrigerant compositions are given in Tables 1 to 3:
(1) A composition comprising 75 Z by weight of difluoromethane and 25 Z by weight of difluoromethyl trifluoromethyl ether.
(2) A composition comprising 50 Z by weight of difluoromethane and 50 Z by weight of difluoromethyl trifluoromethyl ether.
(3) A composition comprising 25 Z by weight of difluoromethane and 75 Z by weight of difluoromethyl trifluoromethyl ether.
(4) A composition comprising 30 Z by weight of difluoromethane and 70 Z by weight of difluoromethyl trifluoromethyl ether.
(5) A composition comprising 35 Z by weight of difluoromethane and 65 Z by weight of difluoromethyl trifluoromethyl ether. Three different sets of operating conditions were used for the analysis. These conditions were as follows :
Set 1:
Evaporator Temperature: -40°C
Condenser Temperature: 32°C
Superheat: 58°C
Subcooling: 0°C
Cooling Duty: 1 KW
Isentropic Compressor Efficiency: 100 z
The results of analysing the various refrigerant compositions in a low temperature refrigeration cycle using these operating conditions are given in Table 1.
Set 2:
Evaporator Temperature: -32°C Condenser Temperature: 43°C
Superheat: 50°C
Subcooling: 0°C
Cooling Duty: 1 KW
Isentropic Compressor Efficiency: 100 Z
The results of analysing the various refrigerant compositions in a low temperature refrigeration cycle using these operating conditions are given in Table 2.
Set 3:
Evaporator Temperature: -40°C Condenser Temperature: 54°C Superheat: 58°C
Subcooling: 0°C
Cooling Duty: 1 KW
Isentropic Compressor Efficiency: 100 Z
The results of analysing the various refrigerant compositions in a low temperature refrigeration cycle' using these operating conditions are given in Table 3.
The performance parameters of the refrigerant compositions which are presented in Tables 1 to 3, i.e. condenser pressure, evaporator pressure, discharge temperature, return gas temperature, volumetric flow, system efficiency (coefficient of performance, by which is meant the ratio of cooling duty achieved to mechanical energy supplied to the compressor), refrigeration capacity (cooling duty per unit swept volume of the compressor), and the glide in the evaporator (the temperature range over which the refrigerant composition boils in the evaporator), are all art recognised parameters. The values for the coefficient of performance shown in the Tables do not take account of superheat.
The performance of Refrigerant R-502 and difluoromethane under the three different sets of operating conditions are also shown in the Tables by way of comparison.
From Tables 1 to 3, it is apparent that refrigerant compositions according to the invention comprising difluoromethyl trifluoromethyl ether and difluoromethane can exhibit a performance in a low temperature refrigeration system which is comparable to that of Refrigerant R-502. If difluoromethane is used as the sole refrigerant in a refrigeration system, high energy efficiencies and high refrigeration capacities relative to Refrigerant R-502 are obtained, as shown by the values for the coefficient of performance and the cooling duty per unit swept volume of the compressor. However, the discharge temperatures, condenser pressures and evaporator pressures which are obtained with difluoromethane are also high and are not ideal when one is looking for a replacement for Refrigerant* R-502. The addition of difluoromethyl trifluoromethyl ether to the difluoromethane provides a means of reducing the discharge temperature, condenser pressure and evaporator pressure while retaining energy efficiencies and refrigeration capacities which are still comparable with and in certain cases superior to R-502. Furthermore, the glide in the evaporator for all the mixed refrigerant compositions tested was 1.4°C or less showing that such compositions are azeotrope like.
Refrigerant compositions according to the invention containing from 25 to 99 Z , e.g. 50 to 99 Z, by weight of difluoromethyl trifluoromethyl ether and from 75 to 1 Z, e.g. 50 to 1 Z, by weight of difluoromethane are preferred as a replacement for Refrigerant R-22, particularly in air conditioning applications. A more preferred refrigerant composition for replacing R-22 in air conditioning applications contains from 70 to 90 Z by weight of difluoromethyl trifluoromethyl ether and from 30 to 10 Z by weight of difluoromethane. A particularly preferred refrigerant composition for replacing R-22 in air conditioning applications contains from 75 to 90 Z by weight of difluoromethyl trifluoromethyl ether and from 25 to 10 Z by weight of difluoromethane.
Tables 4 and 5 show the results of analysing the performance of a number of refrigerant compositions of the invention in a refrigeration cycle to assess the suitability thereof as a replacement for R-22 in air « conditioning applications. All the compositions
5 analysed comprised difluoromethyl trifluoromethyl ether t (E-125 in the Tables) and difluoromethane (R-32 in the
Tables) in varying amounts. The percentage by weight of each component in the refrigerant compositions analysed is given in the second row of the Tables. Thus, the results of analysing the performance of the following
10 refrigerant compositions are given in Tables 4 and 5:
(1) A composition comprising 75 Z by weight of difluoromethane and 25 Z by weight of difluoromethyl trifluoromethyl ether.
15
(2) A composition comprising 50 Z by weight of difluoromethane and 50 Z by weight of difluoromethyl trifluoromethyl ether.
(3) A composition comprising 25 Z by weight of difluoromethane and 75 Z by weight of
20 difluoromethyl trifluoromethyl ether.
(4) A composition comprising 20 Z by weight of difluoromethane and 80 Z by weight of difluoromethyl trifluoromethyl ether.
(5) A composition comprising 15 Z by weight of
25 difluoromethane and 85 Z by weight of difluoromethyl trifluoromethyl ether.
Two different sets of operating conditions were used for the analysis. The conditions used reflect the
30 conditions which are likely to prevail in air conditioning systems using R-22 as the refrigerant. The two sets of conditions were as follows:
Set 4:
35 Evaporator Temperature: 4.44°C
Condenser Temperature: 37.78°C
Superheat: 11.11°C
Subcooling: 0°C
Cooling Duty: 1 KW
Isentropic Compressor Efficiency: 75 Z
The results of analysing the various refrigerant compositions in a refrigeration cycle using these operating conditions are given in Table 4.
Set 5:
Evaporator Temperature: 8.89°C
Condenser Temperature: 37.78°C
Superheat: 11.11°C
Subcooling: 8.83°C
Cooling Duty: 1 KW
Isentropic Compressor Efficiency: 75 Z
The results of analysing the various refrigerant compositions in a refrigeration cycle using these operating conditions are given in Table 5.
The performance parameters which appear in Tables 4 and 5 are the same as those presented in Tables 1 to 3. However, the values for the coefficient of performance given in Tables 4 and 5 take account of superheat.
The performance of Refrigerant R-22 and difluoromethyl trifluoromethyl ether under the two different sets of operating conditions are also shown in Tables 4 an 5 by way of comparison.
From Tables 4 and 5, it is apparent that refrigerant compositions according to the invention comprising difluoromethyl trifluoromethyl ether and difluoromethane can exhibit a performance in an air conditioning system which is similar to that of Refrigerant R-22. It is also evident that refrigerant compositions containing from 75 to 90 Z by weight of difluoromethyl trifluoromethyl ether and from 25 to 10 Z by weight of difluoromethane, especially from 75 • to 85 Z by weight of difluoromethyl trifluoromethyl ether and from 25 to 15 Z by weight of difluoromethane, offer a good alternative to Refrigerant R-22 in air conditioning applications .
The refrigerant compositions of the invention may be prepared by a simple mixing process.
The compositions are useful in all types of compression cycle heat transfer devices. Thus, they m_.T be used to provide cooling by a method involving condensing the refrigerant composition and thereafter evaporating it in a heat exchange relationship with a body to be cooled. They may also be used to provide heating by a method involving condensing the refrigerant composition in a heat exchange relationship with a body to be heated and thereafter evaporating it.
The compositions of the invention provide a good compromise between atmospheric lifetime, ozone depletion, discharge temperature, working pressure and efficiency. They are especially suitable as replacements for R-22 and the R-502 azeotrope. TABLE 1
REFRIGERANT R-502 R-32 ' R-32/E-125
Z BY WEIGHT 100 100 75/25 50/50 25/75
CONDENSER
PRESSURE (Bar) 13.89 20.31 19.12 17.38 14.75
EVAPORATOR
PRESSURE (Bar) 1.31 1.78 1.67 1.51 1.26
DISCHARGE
TEMPERATURE (°C) 110.8 176.5 150.5 126.1 104.2
RETURN GAS
TEMPERATURE (°C) 18.0 18.0 18.2 18.5 18.7
VOLUMETRIC
FLOW (M3/s x 102) 0.180 0.100 0.118 0.141 0.184
COOLING DUTY PER
UNIT SWEPT
VOLUME (KW/m3) 555 1000 847 709 543
COEFFICIENT OF
PERFORMANCE 1.64 1.78 1.74 1.68 1.59
BOILING BP* -45.6 -51.7 -51.07 -49.64 -46.91
POINT (°C) DP** -45.6 -51.7 -50.63 -48.32 -44.43
GLIDE IN
EVAPORATOR (°C) 0 0 0.4 1.0 1.4
* BP = Bubble Point ** DP = Dew Point TABLE 1 CONTINUED
REFRIGERANT R-502 R-32 R-32/E-125 Z BY WEIGHT 100 100 30/70 35/65
CONDENSER
PRESSURE (Bar) 13.89 20.31 15.22 15.95
EVAPORATOR
PRESSURE (Bar) 1.31 1.78 1.32 1.37
DISCHARGE
TEMPERATURE (°C) 110.8 176.5 108.5 112.8
RETURN GAS
TEMPERATURE (°C) 18.0 18.0 18.7 18.7
VOLUMETRIC
FLOW (M3/s x 102) 0.180 0.100 0.172 0.163
COOLING DUTY PER
UNIT SWEPT
VOLUME (KW/m3) 555 1000 581 613
COEFFICIENT OF
PERFORMANCE 1.64 1.78 1.61 1.63
BOILING BP* -45.6 ■51.7 -47.65 -48.31
POINT (°C) DP** -45.6 ■51.7 -45.36 -46.22
GLIDE IN
EVAPORATOR (°C) 0 1.4 1.3
* BP - Bubble Point ** DP - Dew Point
TABLE 2
REFRIGERANT R- 502 R- 32 R- 32 / E- 125
Z BY WEIGHT 100 100 75 / 25 50 / 50 25 / 75
CONDENSER
PRESSURE (Bar) 18.02 26.70 25.15 22.89 19.41
EVAPORATOR
PRESSURE (Bar) 1.84 2.52 2.37 2.13 1.78
DISCHARGE
TEMPERATURE (°C) 110.3 173.4 149.2 125.9 104.6
RETURN GAS
TEMPERATURE (°C) 18.0 18.0 18.2 18.5 18.7
VOLUMETRIC
FLOW (M3/s x 102) 0.140 0.080 0.092 0.112 0.148
COOLING DUTY PER
UNIT SWEPT
VOLUME (KW/m3) 714 1250 1087 893 676
COEFFICIENT OF
PERFORMANCE *1.55 1.73 1.64 1.57 1.46
BOILING BP* -45.6 -51.7 -51.07 -49.64 -46.91
POINT (°C) DP** -45.6 -51.7 -50.63 -48.32 -44.43
GLIDE IN
EVAPORATOR (°C) 0 0 0.4 1.0 1.3
* BP = Bubble Point ** DP - Dew Point TABLE 2 CONTINUED
REFRIGERANT R- 502 R- 32 R - 32 / E - 125
Z BY WEIGHT 100 100 30 / 70 35 / 65
CONDENSER
PRESSURE (Bar) 18.02 26.70 20.15 21.07
EVAPORATOR
PRESSURE (Bar) 1.84 2.52 1.86 1.94
DISCHARGE
TEMPERATURE (°C) 110.3 173.4 108.7 113.2
RETURN GAS
TEMPERATURE (°C) 18.0 18.0 18.6 18.6
VOLUMETRIC
FLOW (M3/s x 102) 0.140 0.080 0.138 0.131
COOLING DUTY PER
UNIT SWEPT
VOLUME (KW/m3) 714 1250 725 763
COEFFICIENT OF
PERFORMANCE 1.55 1.73 1.49 1.50
BOILING BP* -45.6 -51.7 -47.65 -48.31
POINT (°C) DP** -45.6 -51.7 -45.36 -46.22
GLIDE IN
EVAPORATOR (°C) 0 0 1.4 1.3
* BP - Bubble Point ** DP = Dew Point TABLE 3
REFRIGERANT R- 502 R- 32 R- 32 / E-125
Z BY WEIGHT 100 100 75 / 25 50 / 50 25 / 75
CONDENSER
PRESSURE (Bar) 23.01 34.50 32.53 29.70 25.11
EVAPORATOR
PRESSURE (Bar) 1.31 1.78 1.67 1.50 1.25
DISCHARGE
TEMPERATURE (°C) 135.3 216.7 184.4 154.5 127.2
RETURN GAS
TEMPERATURE (°C) 18.0 18.0 18.1 18.4 18.4
VOLUMETRIC
FLOW (M3/s x 102) 0.250 0.130 0.162 0.207 0.298
COOLING DUTY PER
UNIT SWEPT
VOLUME (KW/m3) 400 769 617 483 336
COEFFICIENT OF
PERFORMANCE 0.92 1.13 1.00 0.92 0.80
BOILING BP* -45.6 -51.7 -51.07 -49.64 -46.91
POINT (°C) DP** -45.6 -51.7 -50.63 -48.32 -44.43
GLIDE IN
EVAPORATOR (°C) 0 0 0.3 0.7 0.9
* BP *■ Bubble Point ** DP = Dew Point TABLE 3 CONTINUED
REFRIGERANT R-502 R-32 R-32/E-125 Z BY WEIGHT 100 100 30/70 35/65
CONDENSER
PRESSURE (Bar) 23.01 34.50 26.19 27.06
EVAPORATOR
PRESSURE (Bar) 1.31 1.78 1.31 1.36
DISCHARGE
TEMPERATURE CO 135.3 216.7 132.5 137.7
RETURN GAS
TEMPERATURE (°C) 18.0 18.0 18.5 18.5
VOLUMETRIC
FLOW (M3/s x 102) 0.250 0.130 0.273 0.251
COOLING DUTY PER
UNIT SWEPT
VOLUME (KW/m3) 400 769 366 398
COEFFICIENT OF
PERFORMANCE 0.92 1.13 0.83 0.86
BOILING BP* -45.6 ■51.7 •47.65 •48.31
POINT (°C) DP** -45.6 •51.7 •45.36 ■46.22
GLIDE IN
EVAPORATOR (°C) 0.9 0.9
* BP - Bubble Point ** DP - Dew Point TABLE 4
REFRIGERANT R- 22 E- 125 R- 32 / E- 125
Z BY WEIGHT 100 100 75 / 25 50 / 50 25 / 75
CONDENSER
PRESSURE (Bar) 14.50 12.80 22.14 20.31 17.0.7
EVAPORATOR
PRESSURE (Bar) 5.70 5.00 8.80 7.95 6.68
DISCHARGE
TEMPERATURE (°C) 74.3 49.4 80.0 70.7 60.7
RETURN GAS
TEMPERATURE (βC) 15.5 15.5 15.8 16.4 16.8
VOLUMETRIC
FLOW (M3/s x 102) 0.027 0.035 0.019 0.022 0.026
COOLING DUTY PER
UNIT SWEPT
VOLUME (KW/m3) 3708 2857 5263 4545 3846
COEFFICIENT OF
PERFORMANCE 5.19 4.83 4.85 4.78 4.88
BOILING BP* -41.0 -38.4 -50.07 -49.64 -46.91
POINT (°C) DP** -41.0 -38.4 -50.63 -48.32 -44.43
GLIDE IN
EVAPORATOR (°C) 0 0 0.6 1.6 2.4
* BP = Bubble Point ** DP - Dew Point
TABLE 4 CONTINUED
REFRIGERANT R- 22 E- 125 R- 32 / E- 125
Z BY WEIGHT 100 100 20 / 80 15 / 85
CONDENSER
PRESSURE (Bar) 14.50 12.80 16.31 15.40
EVAPORATOR
PRESSURE (Bar) 5.70 5.00 6.37 6.03
DISCHARGE
TEMPERATURE (°C) 74.3 49.4 58.8 56.4
RETURN GAS
TEMPERATURE (°C) 15.5 15.5 16.7 16.6
VOLUMETRIC
FLOW (M3/s x 10∑) 0.027 0.035 0.028 0.030
COOLING DUTY PER
UNIT SWEPT
VOLUME (KW/m3) 3708 2857 3571 3333
COEFFICIENT OF
PERFORMANCE 5.19 4.83 4.87 4.91
BOILING BP* -41.0 -38.4 -46.01 -44.88
POINT (°C) DP** -41.0 -38.4 -43.41 -42.30
GLIDE IN
EVAPORATOR (°C) 0 0 2.4 2.1
* BP - Bubble Point ** DP - Dew Point
TABLE 5
REFRIGERANT R-22 E-125 R-32/E-125
Z BY WEIGHT 100 100 75/25 50/50 25/75
CONDENSER
PRESSURE (Bar) 14.50 12.80 22.14 20.31 17.07
EVAPORATOR
PRESSURE (Bar) 6.60 5.75 10.09 9.13 7.70
DISCHARGE
TEMPERATURE (°C) 70.4 49.28 75.5 67.8 59.3
RETURN GAS
TEMPERATURE (°C) 20.0 20.0 20.3 20.9 21.5
VOLUMETRIC
FLOW (M3/s x 102) 0.022 0.026 0.015 0.017 0.020
COOLING DUTY PER
UNIT SWEPT
VOLUME (KW/m3) 4560 3846 6667 5882 5000
COEFFICIENT OF
PERFORMANCE 6.60 6.54 6.32 6.29 6.52
BOILING BP* -41.0 -38.4 -51.07 -49.64 -46.91
POINT (°C) DP** -41.0 -38.4 -50.63 -48.32 -44.43
GLIDE IN
EVAPORATOR CO 0 0 0.6 1.8 2.9
* BP - Bubble Point ** DP » Dew Point TABLE 5 CONTINUED
REFRIGERANT R-22 E-125 R-32/E-125 Z BY WEIGHT 100 100 20/80 15/85
CONDENSER
PRESSURE (Bar) 14.50 12.80 16.31 15.40
EVAPORATOR
PRESSURE (Bar) 6.60 5.75 7.34 6.97
DISCHARGE
TEMPERATURE CO 70.4 49.28 57.6 55.6
RETURN GAS
TEMPERATURE CO 20.0 20.0 21.4 21.3
VOLUMETRIC
FLOW (M3/s x 102) 0.022 0.026 0.021 0.023
COOLING DUTY PER
UNIT SWEPT
VOLUME (KW/m3) 4560 3846 4762 4348
COEFFICIENT OF
PERFORMANCE 6.60 6.54 6.54 6.62
BOILING BP* 41.0 38.4
POINT CO DP** 41.0 38.4
GLIDE IN
EVAPORATOR (°C) 2.8 2.6
* BP - Bubble Point ** DP - Dew Point

Claims

Claims :
1. A refrigerant composition comprising a mixture of difluoromethyl trifluoromethyl ether and at least one hydrofluoroalkane selected from difluoromethane, pentafluoroethane and 1,1,1-trifluoroethane.
2. A refrigerant composition as claimed in claim 1, • characterised in that it comprises a mixture of difluoromethyl trifluoromethyl ether and difluoromethane.
3. A refrigerant composition as claimed in claim 2, characterised in that it consists essentially of difluoromethyl trifluoromethyl ether and difluoromethane .
4. A refrigerant composition as claimed in claim 2 or claim 3, characterised in that it comprises from 5 to 95 Z by weight of difluoromethyl trifluoromethyl ether and from 95 to 5 Z by weight of difluoromethane.
5. A refrigerant composition as claimed in any one of claims 2 to 4, characterised in that it comprises from 20 to 80 Z by weight of difluoromethyl trifluoromethyl ether and from 80 to 20 Z by weight of difluoromethane.
6. A refrigerant composition as claimed in any one of claims 2 to 5, characterised in that it comprises from 40 to 80 Z by weight of difluoromethyl tri luoromethyl ether and from 60 to 20 Z by weight of difluoromethane.
7. A refrigerant composition as claimed in any one of claims 2 to 6, characterised in that it comprises from 50 to 75 Z by weight of difluoromethyl trifluoromethyl ether and from 50 to 25 Z by weight of difluoromethane.
8. A refrigerant composition as claimed in any one of claims 2 to 7 , characterised in that it comprises from 50 to 70 Z by weight of difluoromethyl trifluoromethyl ether and from 50 to 30 Z by weight of difluoromethane.
9. A refrigerant composition as claimed in claim 2 or claim 3, characterised in that it comprises from 25 to
*
- 99 Z by weight of difluoromethyl trifluoromethyl ether and from 75 to 1 Z by weight of difluoromethane.
10. A refrigerant composition as claimed in claim 9, characterised in that it comprises from 50 to 99 Z by weight of difluoromethyl trifluoromethyl ether and frpm
10 50 to 1 Z by weight of difluoromethane.
11. A refrigerant composition as claimed in claim 9 or claim 10, characterised in that it comprises from 70 to 90 Z by weight of difluoromethyl trifluoromethyl ether and from 30 to 10 Z by weight of difluoromethane.
12. A refrigerant composition as claimed in any one of
15 claims 9, 10 or 11, characterised in that it comprises from 75 to 90 Z by weight of difluoromethyl trifluoromethyl ether and from 25 to 10 Z by weight of difluoromethane.
13. A refrigerant composition as claimed in claim 1
20 which additionally comprises at least one other refrigerant compound having a low or zero ozone depletion potential selected from other hydrofluoroalkanes and other fluorinated ethers containing residual hydrogen atoms.
25 14. A heat transfer device containing a refrigerant composition as claimed in any one of claims 1 to 13.
15. Use of a refrigerant composition as claimed in any one of claims 1 to 13 in a heat transfer device.
16. A method for providing cooling which comprises 3 condensing the refrigerant composition claimed in any one of claims 1 to 13 and thereafter evaporating it in 1 a heat exchange relationship with a body to be cooled.
17. A method for providing heating which comprises condensing the refrigerant composition claimed in any
35 one of claims 1 to 13 in a heat exchange relationship with a body to be heated and thereafter evaporating it
EP93900353A 1992-01-10 1992-12-23 Compositions useful as refrigerants Ceased EP0620838A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB929200523A GB9200523D0 (en) 1992-01-10 1992-01-10 Compositions useful as refrigerants
GB9200523 1992-01-10
PCT/GB1992/002383 WO1993014174A1 (en) 1992-01-10 1992-12-23 Compositions useful as refrigerants

Publications (1)

Publication Number Publication Date
EP0620838A1 true EP0620838A1 (en) 1994-10-26

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EP93900353A Ceased EP0620838A1 (en) 1992-01-10 1992-12-23 Compositions useful as refrigerants

Country Status (8)

Country Link
EP (1) EP0620838A1 (en)
JP (1) JPH07503741A (en)
KR (1) KR940703903A (en)
AU (1) AU666510B2 (en)
BR (1) BR9207017A (en)
CA (1) CA2126187A1 (en)
GB (1) GB9200523D0 (en)
WO (1) WO1993014174A1 (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BR9207027A (en) * 1992-01-10 1995-12-05 Ici Plc Refrigerant composition heat transfer device and processes to provide cooling and heating
US5605882A (en) 1992-05-28 1997-02-25 E. I. Du Pont De Nemours And Company Azeotrope(like) compositions of pentafluorodimethyl ether and difluoromethane
GB9414134D0 (en) * 1994-07-13 1994-08-31 Ici Plc Refrigerant compositions
GB9414110D0 (en) * 1994-07-13 1994-08-31 Ici Plc Refrigeration compositions
GB9414136D0 (en) * 1994-07-13 1994-08-31 Ici Plc Refrigerant compositions
GB9414133D0 (en) * 1994-07-13 1994-08-31 Ici Plc Refrigerant compositions
GB9415159D0 (en) * 1994-07-27 1994-09-28 Ici Plc Refrigerant compositions
FR2732242B1 (en) * 1995-03-28 1997-05-23 Elf Aquitaine ACTIVE COMPOSITE WITH LAMINATED STRUCTURE AND ITS USE AS A REACTION MEDIUM
FR2733241B1 (en) * 1995-04-20 1997-05-30 Atochem Elf Sa PSEUDO-AZEOTROPIC MIXTURES BASED ON DIFLUOROMETHANE AND PENTAFLUORODIMETHYLETHER, AND THEIR APPLICATIONS AS REFRIGERANTS
AU7663096A (en) * 1995-10-18 1997-05-07 Allied-Signal Inc. Compositions of pentafluoromethyl ether and a hydrocarbon
IT1293326B1 (en) * 1997-07-11 1999-02-16 Ausimont Spa REFRIGERANT COMPOSITIONS
EP1251020B1 (en) * 2000-01-04 2007-11-28 Daikin Industries, Ltd. Car air conditioner and car with its conditioner
US7080522B2 (en) 2000-01-04 2006-07-25 Daikin Industries, Ltd. Car air conditioner and car with its conditioner

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US4948526A (en) * 1989-09-26 1990-08-14 Allied-Signal Inc. Azeotrope-like compositions of pentafluorodimethyl ether and monochlorodifluoromethane
US4978467A (en) * 1989-09-26 1990-12-18 Allied-Signal Inc. Azeotrope-like compositions of pentafluoroethane and difluoromethane
BR9207027A (en) * 1992-01-10 1995-12-05 Ici Plc Refrigerant composition heat transfer device and processes to provide cooling and heating
US5605882A (en) * 1992-05-28 1997-02-25 E. I. Du Pont De Nemours And Company Azeotrope(like) compositions of pentafluorodimethyl ether and difluoromethane

Non-Patent Citations (1)

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Title
See references of WO9314174A1 *

Also Published As

Publication number Publication date
AU666510B2 (en) 1996-02-15
WO1993014174A1 (en) 1993-07-22
AU3168893A (en) 1993-08-03
KR940703903A (en) 1994-12-12
CA2126187A1 (en) 1993-07-22
GB9200523D0 (en) 1992-02-26
BR9207017A (en) 1995-12-05
JPH07503741A (en) 1995-04-20

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