CA2126185A1 - Compositions useful as refrigerants - Google Patents
Compositions useful as refrigerantsInfo
- Publication number
- CA2126185A1 CA2126185A1 CA002126185A CA2126185A CA2126185A1 CA 2126185 A1 CA2126185 A1 CA 2126185A1 CA 002126185 A CA002126185 A CA 002126185A CA 2126185 A CA2126185 A CA 2126185A CA 2126185 A1 CA2126185 A1 CA 2126185A1
- Authority
- CA
- Canada
- Prior art keywords
- weight
- tetrafluoroethane
- refrigerant
- refrigerant composition
- 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.)
- Abandoned
Links
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
- 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
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Combustion & Propulsion (AREA)
- Thermal Sciences (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Lubricants (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
A refrigerant composition comprising a mixture of 1,1,1,2-tetrafluoroethane and at least one fluorinated ether selected from trifluoromethyl methyl ether and fluoromethyl trifluoromethyl ether is claimed.
Description
WO 93/14173 PCr/GB92/02382 212618~ -CO~POSITIONS USEFaL AS REFRIGERANTS.
ThB present in~ention relates generally to refrigerant compositions for cooling and heating applications and to the use of such compositions in heat transfer devices. More particularly, the pre~ent invention is concerned with refrigerant composi~ions 1~ which are designed to rep}ace dichlorodifluoromethane (Refrigerant R-12).
~ echa~ical refrigerstion systems a~d relsted heat transfer deYices such as heat pumps and air-conditioning sy~ems are well known. In such devices, a refrigerant liquid of a sultable boiling point evaporates at low pressure taking heat from surrounding zone. The resulting vapour ~s then compre~sed a~d passed to a conden~er where it condenses a~d give~ off heat to a seco~d zone. the condensate being returned through an e~pansion ~alve to the evaporator, so completing the c~cle. The mechanical energy required for compressing the vspour 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 }ow toxic~ty, non-flammability, non-corrosivity, high stability and freedom from ob3ectionable odour.
~itherto, heat transfer device~ have tended to use fuLly and partially halogenated chlorofluorocarbon re~rigerants. Particular mention may be made of -dichlorodifluoromethane (Refrigerant R-12) which possesse~ a suitable combination of properties and has or many ye~rs been the most widely used refrigerant.
:
212618~ 2 -In recent years, howeYer, there has been -:
increasing international concern that the fully and partially halogenated chlorofluorocarbons may be damaging the earth's protective ozone layer and ~here ~
is general agreement that their manufacture and use ::
should be severely restricted and eventually phased out completely.
Whilst heat ~ransfer devices of the type to which the present invention relates are essentially closed systems, loss of refrigera~t to the atmosphere can occur due to leakage during operation of the equipment or during maintenance procedure~. It is imporsant, therefore, to replace fully and partially halogenated c~lorofluorocarbon refrigerants by materials having subs~antially lower, preferably zero, ozone depl~tion potential~.
In addition to the possibility of ozone depletion, it has been suggested that sig~lfica~ concentratio~s 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 as a replacement for Refrigerant R-12. The compo~ition contains refrigerant -compounds which ha~e e3sentially zero ozone depletion pot2ntials and comparatively low direct global warming potentials. --:
~ccordingly, the present invention provides a re~rigerant composition comprising a mi~ture of 1,1,1,2-tetrafluoroethane (Cr3CH2F) and at least one 21261~
fluorinated ether selected from trifluoromethyl meehyl ether (CF30C83) and fluoromethyl trifluoromethyl ether ( CF30C~2F ) Refrigerant compositions in accordance with rhe present invention typically contain from 5 to 952 by weight of 1,1,1,2-tetrafluoroethane and from 95 to 5Z
by weight of the ether. Additionally, the refrigerant compositions of the invention may contain other refrigerant compounds which have low and pre~erably ~-zero ozone depletion potentials, for e~ample other hydrofluoroalksne~ and/or other fluorin~ted ethers -`
containing residual hydrogen atoms. Esamples of other 1~ hydrofluoroalk~nes which msy be incorporsted in the refrigerant compositions of the invention include difluoromethane (R-32), l,l.l-~rifluoroethane (R-143a), 1.1,2,2-tetrafluoroethane ~R-134), pentafluoroethane (R-125) and l,l-difluoroethane ~R-152a). E~amples of other fluorinated ethers which ma~ be included in the refrigerant composition~ of the invention are the fluorinated dimethyl ethers containing re~idual h~drogen stDms~
Although the refrigerant compositlons of the invention may comprise other refrigerant compounds, the preferred refrigerant compositions of the invention -~
consist ess~ntially of 1,1,1.2-tetrafluoroethane and at least one fluorinated ether selected from trifluoromethyl methyl ether and fluoromethyl -trifluoromethyl ether.
Although the refrigerant compositions of ehe invention may be zeotropic they are preferably azeotropic or azeotrope-like.
In one embodiment of the present invention, the refrigerant composition compri~es a mixture of 1,1,1,2-tetra~luoroethane and fluoromethyl W093/14173 PCTt~B92/02382 ; ! i ` ~ ;
21261~ - 4 -trifluoromethyl ether. A specific composition of this -~
type is one which consists essentially of the stated components. Such compositions will typically comprise from 25 to 75 2 by weigh~ of 1,1,1,2-tetrafluoroethane and from 75 to 2~ ~ by weight of fluoromethyl trifluoromethyl ether. Refrigerant compositions of the invention comprising 1,1,1,2-tetrafluoroethane and fluoromethyl trifluoromethyl ether a~ essential compone~ts may suit bly replace Refrigera~t R-12 in many applications. Ho~èver, such compositions may be particularly useful as a replacement for R-12 in heat pumps and automotive air conditioners. Heat pumps snd automotive air conditioners operate with high discharge temperatures, typically around 80 C, which tends to result in fairly high pressures in the co~denser. B~
using blends of 1,1,1.2-tetrafluoroethane and fluoromethyl trifluoromethyl ether as the working fluid in such s~tems, it is possible ~o achieve lower conden~er pressures at these high discharge temperatures than is possible when Refrigerant R-12 or 1,1,1,2-tetrafluoroethane (the generally accepted replacement for Refrigerant R-12) are u~ed. Our research indicates thst at a discharge temperature of 80C a condenser pressure of around 17.7 bar is attainable when using a refrigerant composition comprising 25 Z by weight of 1,1,1,2-tetrafluoroethane and 75 Z by weight of fluoromethyl trifluoromethyl ether.
Table 1 shows the performance of a number of refrigerant compositions of the invention comprising 1,1,1,2-tetrafluoroethane (R-134a in the Table) and fluoromethyl trifluoromethyl ether (E-134a in the Table). The percentage by weight of each component in the refrigerant compositions evaluated is gi~en in the 2126I8.~-second row of the Table. Thus, refrigerant compo3itions respectively comprising 75 Z by weight of 1,1,1,2-tetrafluoroethane and 25 2 by weight of fluoromethyl trifluoromethyl ether; 50 ~ by weight of 1,1,1.2-tetrafluoroethane snd 50 2 by weight of fluoromethyl trifluoromethyl ether; and 25 Z by weight of 1,1,1,2-tetrafluoroe~ha~e and 75 ~ by weight of fluoromethyl trifluoromethyl ether were evaluated. The opera~ing conditlons which were 3elected for the evaluation are represe~tative of those esisting in a domestic refrigeration ~ystem. Specifically, these conditions were as follows:
Evaporator Temperature: -25C
Condenser Temperature: 40C
Superheat: 45C
Subcooling: lO~C
Cooling Duty: 1 ~W
Isentropic Compressor Efficiency: 75 The performance parameters of the refrigerant compositions which are presented in the Table, i.e.
conden~er pressure, evaporator pressure, discharge ~5 temperature, return gas temperature, volumetric flow, system efficiency (coefficient of performance, b~ which is meant the ratio of cooling duty achieved to mechanical energy supplied to the compre~or), refrigeration capacity (cooling du~y per unit swept volume of the compressor)~ and the glide in the evaporator ~the temperature range over which the refrigerant composition boils in the evapora~or), are all art recognised parameters.
The performance of Refrigeran~ R-12 and 1,1,1,2-tetrafluoroethane, which is the generally WO 93tl4173 PCT/GB92/02382 212618~ ` -accepted replacement for Refrigerant R-12, under identical opersting condi~ions are also shown in Table 1 by way of comparison. -From Table 1, it is apparent that refrigerant .
compositions according to the invention comprising 1,1.1,2-tetrafluoroethane and fluoromethyl trifluoromethyl ether can e~hibit a performance in a refrigera~ion s~stem which is not too far removed from that of Refrigerant R-12. Furthermore, the gl~de in the e~aporator was o~ly 0. 29C for all ~he miYed refrigerant compositions evaluated showing that such compositions are azeotrope like.
In a prefer~ed embodiment of the pre~ent -:~
inventio~, the refrigerant composition comprises a mixture of 1,1,1,2-tetrafluoroethane and .:
trifluoromethyl methyl ether, optio~ally together with :~
fluoromethyl trifluoromethyl ether and/or at least one ~:~
other fluorinated e~her containing residual hydrogen :~
atoms snd/or at least one other hydrofluoroalkane.
Particulsrly preferred refrigerant compositions are mixtures consisting essentiallr of 191,1,2-tetrafluoroethane and trifluoromethyl methyl ether. :
2S Refrigerant compositions comprising a mixt~re of l,l,l,Z-tetrafluoroethane and trifluoromethyl methyl ether have been found to eshibit a similar performance to Refrigerant R-12 in a refrigeration cycle. In consequence, such compositions may be used in plaoe of Re~rigerant R-12 which is at present widely used as 8 working fluid in refrigeration systems and related heat trans~er devices. Purthermore, compositions comprising 1,1,1,2-tetrafluoroethane a~d trifluoromethyl methyl ether benefit from the particularly short atmo~pheric lifetlme of trifluoromethrl methyl ether (ca 3.6 years) W093l14173 PCT/GB92~02382 212618i and, thus, can exhibit a low direct global warming pOt ential.
Preferred refrigersnt composition3 based on 1,1,1,2-tetrafluoroethane and trifluoromethyl methyl ether comprise from 5 to 75 ~ by weight of ~-1,1,1,2-tetrafluoroethane and from 95 to 25 Z by weight of trifluoromethyl methyl` ether. Particularly preferred refri~erant compositions of this t~pe compriRe from 5 ~;
to 60 ~ by we~ght of 1,1,1,2-tetrafluoroethane and from 95 to 40 2 by weight o~ trifluoromethyl mQthyl ether, with compositio~s comprising from 25 to 50 ~ b~ weight of 1,1,1~2-te~rafluoroe~hane and from 75 to 50 2 by weight of trifluoromethyl methyl ether being especially preferred. The preferred compositions are therefore characterised b~ the presence of a 3ubsta~tial amount of trifluoromethy} methyl ether which confers on the composition a lower direct global warming pote~tial.
~owe~er, surprisingly such compositlons also e2hibit a performance ~n a refrigeration system which is comparable to Refrigerant R-12.
Trifluoromethyl methyl ether is slightly flammable and our reRearch suggests that mixed refriBerant compositions comprising in e~cess of 40 ~ by weight of this ether and less than 60 Z by weight of 1,1,1.2-tetrafluoroethane may also be flammable. It is believed that the potential flammability o~ such refrigerant compositions may not be a problem in practice, bearing in mind that heat transfer devices are e~sentially closed systems and that~certain devices, such as domestic refrigeration systems, only contain small quantities of the refrigerAnt. Moreover, the benefit of using a refrigerant composition comprising a large amQunt of trifluoromethyl methyl ether opposite reduced global warming potential may 212618.~ 8 -outweigh any possible disadvantage opposite flammability. ~owever, if flammability is a concern, then compositions containing from 70 to 95 ~ by weight of 1,1,1,2-tetrafluoroethane and from 30 to 5 2 by weight of trifluoromethyl methyl ether are preferred, with compositio~s containing from 70 to 85 ~ by weight of 1.1~1,2-tetrafluoroethane and from 30 to 15 Z by weight of trifluoromethyl methyl ether being particularly pre~erred, in view of their non-flam~ability.
Tsble 2 shows the performance of a number of refrigerant compositions of the i~Yention comprising 1,1.1,2-tetrafluoroethane (R-134a in the Table) and trif}uoromethyl methyl ether (E-143a in the Table). The percentage by weight of each component in the refrigerant compo~itions evaluated is given in the ~econd row of the Table. Thus, refrigeran~ compositions respectively comprising 75 Z by weight of 1.1,1,2-tetrafluoroethane and 25 Z by weight of tri~luoromethyl methyl ether; 50 2 by weight of 1,1,1,2-tetrafluoroethane and 50 ~ by weight of trifluoromethyl methyl ether; and 25 Z- by weight of 1,1,1~2-tetrafluoroethane and 75 Z by weight of trifluoromethyl methyl ether were evaluated. The operating contitions which were selected for the evaluation are representative of those existing in a dome~tic refrigeration system. Specifically, the e conditions were a~ follows:
Evaporator Temperarure: -25C
Condenser Temperature: 40C
Superheat: 45 D C
Subcooli~g: 10C
Cool~ng Duty: 1 XW
W093/14173 PCT~GB92/02382 212618~ ~ `
g `. .
Isentropic Compressor Efficiency: 7S
- '' '~
The perfor~ance parameters of the refrigerant ~-compositions ~hich are presented in the Table, 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 ach$eved to mechanical energy supplied to the compressor)~
refrigeration capacity (cooling duty per unit swept vslume of the compressor), and the glide in the evaporator tthe temperature range o~er which the refrigerant composition boils in the evaporator~, are all art recognised parameters.
T~e performance of Refrigerant R-12 a~d --1,1,1,2-~etrafluoroethane, which is the generally accepted replacement for Refrigerant R-12, under identical operating conditions are also ~hown in Table 2 by ~ay of comparison.
~rom Table 2, lt is apparent that refrigerant composition~ accordlng to the invention comprising 1,1,1,2-tetrafluoroethane and trifluoromethyl methyl ether csn eshibit a performance in a refrigeration system which i5 comparable to that of Refrigerant R-12. ~-Furthermore, the glide in the evaporator was -~
essentially zero for all the mixed refrigerant compositions tested showing that such cvmpositions are azeotrope like.
The refrigerant compositions of the invention may be prepared by a simple mixing process. -The compssitions are useful in all types of compression cycle heat tsansrer de~iceR. Thus, they may be used to pzovide cooli~g by a method involving conden~ing the refrigerant composition and thereafter 3 PC~/GB92/02382 ~1261~ `
- 1 0 _ , evaporating it in a heat e~change relationship with a body to be cooled. They may also be used to provide hesting by a method in~olYing condensing the refrigerant composition in a heat exchange relationship -~
with B body to be heated and thereafter evaporating it.
The compositions of the invention provide a good compromi3e between capacity and efficiency combined with low atmospheric lifetime and esse~tially zero ozone depletion. They are especially suitable for applications currently sa~isfied by Refrlgerant R-12, for e~ample domestic refrigeration. automobile air-conditioning and refrig~rated food transport.
:-~-W093/14173 PCT/GB92~02382 ;
ll- 212618~ ~
REFRIGERANT R-12R-134a R-134a/E-134a . .. _ ... , ..
% BY WEIGHT 100 100 75/25 50/50 25/75 , . .......... . . . , . .
CONDENSER
1 PRESSURE ~Bar)9.6010.10 9.04 8.07 7.28 O , . . ....... ..
EVAPORATOR
PRESS~RE (Bar)1.23 1.07 1.01 0.94 0.8B
DISC~AR~E
TEMPERAT~RE (C)120.8110,9 106.5 100.8 96.2 RET~RN GAS
TEMPERATURE ~C)20.020.0 20.I 20.1 20.1 VOLUMETRIC
FLOW (M3l3 x 102) 0.140 0.150 0.169 0.187 0.206 , . .
COOLING DUTY PER
UNIT SWEPT
VOL~ME (~Wtm3) 7I4 F67 592 534 485 ~-COEFFICIENT OF
PERFORMANCE 1.90 1.86 1.87 1.86 1.83 BOILING BP* -29.8 -26.2 -25.31-23.91 -21.90 POINT (C) DP~ -29.8_Z6.2 -25.07-23.51 -22.26 GLIDE IN _ EVAPORATOR (C) O O 0.2 0.2 0.2 * BP - Bubble Point ** DP - Dew Point 3~
21261~S 12 -REFRICER _ R-12 R-134a R-134alE-143a .. . .. . , _ .. . , . . _ .
~ ~Y WEIG~T 100 100 75125 50~50 25/75 .:
~ . ___ :' CONDENSER . :-:
PRESS~RE (Bar) 9 63 10.10 9.58 9 2D ~.85 -P~ESS~RE ( Bar ) 1. 23 1. 07 1. 02 1. 00 O.97 .. . - . . . . - . _ DISC~ARGE
TE~PERATURE (C) 120.8 110.9 110.0 107.5 105.1 ___ _ _-- .
R~T~RN GAS ~:
TE~PERAT~RE (C) 20.0 20.0 20.0 29.0 20.0 .
. . . - ... -............ :::VOLU~ETRIC
FLOW (M31~ s lOZ ) 0.140 0.150 0.162 0.170 0-176 . . . _ . . . . , -COOLI~G D~TY PE~
UNIT SWEPT
VOLUME ~W/m3) 714 667 617 588 56B
COEFFICIENT OF
PERFORMANCE 1.90 1.86 1.85 1.85 1.85 . . _ . . . ~ .
BOILING BP~ -29.8 -26.2 -25.61 -24.94 -24.45 POINT ~C) DP*~ -29.8 -26.2 -25.54 -24.88 -24.42 . . . _ GLIDE IN
EVAPORATOR (C) O O _ O i O
* BP D Bubb1e Point ** DP - Dew Point
ThB present in~ention relates generally to refrigerant compositions for cooling and heating applications and to the use of such compositions in heat transfer devices. More particularly, the pre~ent invention is concerned with refrigerant composi~ions 1~ which are designed to rep}ace dichlorodifluoromethane (Refrigerant R-12).
~ echa~ical refrigerstion systems a~d relsted heat transfer deYices such as heat pumps and air-conditioning sy~ems are well known. In such devices, a refrigerant liquid of a sultable boiling point evaporates at low pressure taking heat from surrounding zone. The resulting vapour ~s then compre~sed a~d passed to a conden~er where it condenses a~d give~ off heat to a seco~d zone. the condensate being returned through an e~pansion ~alve to the evaporator, so completing the c~cle. The mechanical energy required for compressing the vspour 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 }ow toxic~ty, non-flammability, non-corrosivity, high stability and freedom from ob3ectionable odour.
~itherto, heat transfer device~ have tended to use fuLly and partially halogenated chlorofluorocarbon re~rigerants. Particular mention may be made of -dichlorodifluoromethane (Refrigerant R-12) which possesse~ a suitable combination of properties and has or many ye~rs been the most widely used refrigerant.
:
212618~ 2 -In recent years, howeYer, there has been -:
increasing international concern that the fully and partially halogenated chlorofluorocarbons may be damaging the earth's protective ozone layer and ~here ~
is general agreement that their manufacture and use ::
should be severely restricted and eventually phased out completely.
Whilst heat ~ransfer devices of the type to which the present invention relates are essentially closed systems, loss of refrigera~t to the atmosphere can occur due to leakage during operation of the equipment or during maintenance procedure~. It is imporsant, therefore, to replace fully and partially halogenated c~lorofluorocarbon refrigerants by materials having subs~antially lower, preferably zero, ozone depl~tion potential~.
In addition to the possibility of ozone depletion, it has been suggested that sig~lfica~ concentratio~s 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 as a replacement for Refrigerant R-12. The compo~ition contains refrigerant -compounds which ha~e e3sentially zero ozone depletion pot2ntials and comparatively low direct global warming potentials. --:
~ccordingly, the present invention provides a re~rigerant composition comprising a mi~ture of 1,1,1,2-tetrafluoroethane (Cr3CH2F) and at least one 21261~
fluorinated ether selected from trifluoromethyl meehyl ether (CF30C83) and fluoromethyl trifluoromethyl ether ( CF30C~2F ) Refrigerant compositions in accordance with rhe present invention typically contain from 5 to 952 by weight of 1,1,1,2-tetrafluoroethane and from 95 to 5Z
by weight of the ether. Additionally, the refrigerant compositions of the invention may contain other refrigerant compounds which have low and pre~erably ~-zero ozone depletion potentials, for e~ample other hydrofluoroalksne~ and/or other fluorin~ted ethers -`
containing residual hydrogen atoms. Esamples of other 1~ hydrofluoroalk~nes which msy be incorporsted in the refrigerant compositions of the invention include difluoromethane (R-32), l,l.l-~rifluoroethane (R-143a), 1.1,2,2-tetrafluoroethane ~R-134), pentafluoroethane (R-125) and l,l-difluoroethane ~R-152a). E~amples of other fluorinated ethers which ma~ be included in the refrigerant composition~ of the invention are the fluorinated dimethyl ethers containing re~idual h~drogen stDms~
Although the refrigerant compositlons of the invention may comprise other refrigerant compounds, the preferred refrigerant compositions of the invention -~
consist ess~ntially of 1,1,1.2-tetrafluoroethane and at least one fluorinated ether selected from trifluoromethyl methyl ether and fluoromethyl -trifluoromethyl ether.
Although the refrigerant compositions of ehe invention may be zeotropic they are preferably azeotropic or azeotrope-like.
In one embodiment of the present invention, the refrigerant composition compri~es a mixture of 1,1,1,2-tetra~luoroethane and fluoromethyl W093/14173 PCTt~B92/02382 ; ! i ` ~ ;
21261~ - 4 -trifluoromethyl ether. A specific composition of this -~
type is one which consists essentially of the stated components. Such compositions will typically comprise from 25 to 75 2 by weigh~ of 1,1,1,2-tetrafluoroethane and from 75 to 2~ ~ by weight of fluoromethyl trifluoromethyl ether. Refrigerant compositions of the invention comprising 1,1,1,2-tetrafluoroethane and fluoromethyl trifluoromethyl ether a~ essential compone~ts may suit bly replace Refrigera~t R-12 in many applications. Ho~èver, such compositions may be particularly useful as a replacement for R-12 in heat pumps and automotive air conditioners. Heat pumps snd automotive air conditioners operate with high discharge temperatures, typically around 80 C, which tends to result in fairly high pressures in the co~denser. B~
using blends of 1,1,1.2-tetrafluoroethane and fluoromethyl trifluoromethyl ether as the working fluid in such s~tems, it is possible ~o achieve lower conden~er pressures at these high discharge temperatures than is possible when Refrigerant R-12 or 1,1,1,2-tetrafluoroethane (the generally accepted replacement for Refrigerant R-12) are u~ed. Our research indicates thst at a discharge temperature of 80C a condenser pressure of around 17.7 bar is attainable when using a refrigerant composition comprising 25 Z by weight of 1,1,1,2-tetrafluoroethane and 75 Z by weight of fluoromethyl trifluoromethyl ether.
Table 1 shows the performance of a number of refrigerant compositions of the invention comprising 1,1,1,2-tetrafluoroethane (R-134a in the Table) and fluoromethyl trifluoromethyl ether (E-134a in the Table). The percentage by weight of each component in the refrigerant compositions evaluated is gi~en in the 2126I8.~-second row of the Table. Thus, refrigerant compo3itions respectively comprising 75 Z by weight of 1,1,1,2-tetrafluoroethane and 25 2 by weight of fluoromethyl trifluoromethyl ether; 50 ~ by weight of 1,1,1.2-tetrafluoroethane snd 50 2 by weight of fluoromethyl trifluoromethyl ether; and 25 Z by weight of 1,1,1,2-tetrafluoroe~ha~e and 75 ~ by weight of fluoromethyl trifluoromethyl ether were evaluated. The opera~ing conditlons which were 3elected for the evaluation are represe~tative of those esisting in a domestic refrigeration ~ystem. Specifically, these conditions were as follows:
Evaporator Temperature: -25C
Condenser Temperature: 40C
Superheat: 45C
Subcooling: lO~C
Cooling Duty: 1 ~W
Isentropic Compressor Efficiency: 75 The performance parameters of the refrigerant compositions which are presented in the Table, i.e.
conden~er pressure, evaporator pressure, discharge ~5 temperature, return gas temperature, volumetric flow, system efficiency (coefficient of performance, b~ which is meant the ratio of cooling duty achieved to mechanical energy supplied to the compre~or), refrigeration capacity (cooling du~y per unit swept volume of the compressor)~ and the glide in the evaporator ~the temperature range over which the refrigerant composition boils in the evapora~or), are all art recognised parameters.
The performance of Refrigeran~ R-12 and 1,1,1,2-tetrafluoroethane, which is the generally WO 93tl4173 PCT/GB92/02382 212618~ ` -accepted replacement for Refrigerant R-12, under identical opersting condi~ions are also shown in Table 1 by way of comparison. -From Table 1, it is apparent that refrigerant .
compositions according to the invention comprising 1,1.1,2-tetrafluoroethane and fluoromethyl trifluoromethyl ether can e~hibit a performance in a refrigera~ion s~stem which is not too far removed from that of Refrigerant R-12. Furthermore, the gl~de in the e~aporator was o~ly 0. 29C for all ~he miYed refrigerant compositions evaluated showing that such compositions are azeotrope like.
In a prefer~ed embodiment of the pre~ent -:~
inventio~, the refrigerant composition comprises a mixture of 1,1,1,2-tetrafluoroethane and .:
trifluoromethyl methyl ether, optio~ally together with :~
fluoromethyl trifluoromethyl ether and/or at least one ~:~
other fluorinated e~her containing residual hydrogen :~
atoms snd/or at least one other hydrofluoroalkane.
Particulsrly preferred refrigerant compositions are mixtures consisting essentiallr of 191,1,2-tetrafluoroethane and trifluoromethyl methyl ether. :
2S Refrigerant compositions comprising a mixt~re of l,l,l,Z-tetrafluoroethane and trifluoromethyl methyl ether have been found to eshibit a similar performance to Refrigerant R-12 in a refrigeration cycle. In consequence, such compositions may be used in plaoe of Re~rigerant R-12 which is at present widely used as 8 working fluid in refrigeration systems and related heat trans~er devices. Purthermore, compositions comprising 1,1,1,2-tetrafluoroethane a~d trifluoromethyl methyl ether benefit from the particularly short atmo~pheric lifetlme of trifluoromethrl methyl ether (ca 3.6 years) W093l14173 PCT/GB92~02382 212618i and, thus, can exhibit a low direct global warming pOt ential.
Preferred refrigersnt composition3 based on 1,1,1,2-tetrafluoroethane and trifluoromethyl methyl ether comprise from 5 to 75 ~ by weight of ~-1,1,1,2-tetrafluoroethane and from 95 to 25 Z by weight of trifluoromethyl methyl` ether. Particularly preferred refri~erant compositions of this t~pe compriRe from 5 ~;
to 60 ~ by we~ght of 1,1,1,2-tetrafluoroethane and from 95 to 40 2 by weight o~ trifluoromethyl mQthyl ether, with compositio~s comprising from 25 to 50 ~ b~ weight of 1,1,1~2-te~rafluoroe~hane and from 75 to 50 2 by weight of trifluoromethyl methyl ether being especially preferred. The preferred compositions are therefore characterised b~ the presence of a 3ubsta~tial amount of trifluoromethy} methyl ether which confers on the composition a lower direct global warming pote~tial.
~owe~er, surprisingly such compositlons also e2hibit a performance ~n a refrigeration system which is comparable to Refrigerant R-12.
Trifluoromethyl methyl ether is slightly flammable and our reRearch suggests that mixed refriBerant compositions comprising in e~cess of 40 ~ by weight of this ether and less than 60 Z by weight of 1,1,1.2-tetrafluoroethane may also be flammable. It is believed that the potential flammability o~ such refrigerant compositions may not be a problem in practice, bearing in mind that heat transfer devices are e~sentially closed systems and that~certain devices, such as domestic refrigeration systems, only contain small quantities of the refrigerAnt. Moreover, the benefit of using a refrigerant composition comprising a large amQunt of trifluoromethyl methyl ether opposite reduced global warming potential may 212618.~ 8 -outweigh any possible disadvantage opposite flammability. ~owever, if flammability is a concern, then compositions containing from 70 to 95 ~ by weight of 1,1,1,2-tetrafluoroethane and from 30 to 5 2 by weight of trifluoromethyl methyl ether are preferred, with compositio~s containing from 70 to 85 ~ by weight of 1.1~1,2-tetrafluoroethane and from 30 to 15 Z by weight of trifluoromethyl methyl ether being particularly pre~erred, in view of their non-flam~ability.
Tsble 2 shows the performance of a number of refrigerant compositions of the i~Yention comprising 1,1.1,2-tetrafluoroethane (R-134a in the Table) and trif}uoromethyl methyl ether (E-143a in the Table). The percentage by weight of each component in the refrigerant compo~itions evaluated is given in the ~econd row of the Table. Thus, refrigeran~ compositions respectively comprising 75 Z by weight of 1.1,1,2-tetrafluoroethane and 25 Z by weight of tri~luoromethyl methyl ether; 50 2 by weight of 1,1,1,2-tetrafluoroethane and 50 ~ by weight of trifluoromethyl methyl ether; and 25 Z- by weight of 1,1,1~2-tetrafluoroethane and 75 Z by weight of trifluoromethyl methyl ether were evaluated. The operating contitions which were selected for the evaluation are representative of those existing in a dome~tic refrigeration system. Specifically, the e conditions were a~ follows:
Evaporator Temperarure: -25C
Condenser Temperature: 40C
Superheat: 45 D C
Subcooli~g: 10C
Cool~ng Duty: 1 XW
W093/14173 PCT~GB92/02382 212618~ ~ `
g `. .
Isentropic Compressor Efficiency: 7S
- '' '~
The perfor~ance parameters of the refrigerant ~-compositions ~hich are presented in the Table, 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 ach$eved to mechanical energy supplied to the compressor)~
refrigeration capacity (cooling duty per unit swept vslume of the compressor), and the glide in the evaporator tthe temperature range o~er which the refrigerant composition boils in the evaporator~, are all art recognised parameters.
T~e performance of Refrigerant R-12 a~d --1,1,1,2-~etrafluoroethane, which is the generally accepted replacement for Refrigerant R-12, under identical operating conditions are also ~hown in Table 2 by ~ay of comparison.
~rom Table 2, lt is apparent that refrigerant composition~ accordlng to the invention comprising 1,1,1,2-tetrafluoroethane and trifluoromethyl methyl ether csn eshibit a performance in a refrigeration system which i5 comparable to that of Refrigerant R-12. ~-Furthermore, the glide in the evaporator was -~
essentially zero for all the mixed refrigerant compositions tested showing that such cvmpositions are azeotrope like.
The refrigerant compositions of the invention may be prepared by a simple mixing process. -The compssitions are useful in all types of compression cycle heat tsansrer de~iceR. Thus, they may be used to pzovide cooli~g by a method involving conden~ing the refrigerant composition and thereafter 3 PC~/GB92/02382 ~1261~ `
- 1 0 _ , evaporating it in a heat e~change relationship with a body to be cooled. They may also be used to provide hesting by a method in~olYing condensing the refrigerant composition in a heat exchange relationship -~
with B body to be heated and thereafter evaporating it.
The compositions of the invention provide a good compromi3e between capacity and efficiency combined with low atmospheric lifetime and esse~tially zero ozone depletion. They are especially suitable for applications currently sa~isfied by Refrlgerant R-12, for e~ample domestic refrigeration. automobile air-conditioning and refrig~rated food transport.
:-~-W093/14173 PCT/GB92~02382 ;
ll- 212618~ ~
REFRIGERANT R-12R-134a R-134a/E-134a . .. _ ... , ..
% BY WEIGHT 100 100 75/25 50/50 25/75 , . .......... . . . , . .
CONDENSER
1 PRESSURE ~Bar)9.6010.10 9.04 8.07 7.28 O , . . ....... ..
EVAPORATOR
PRESS~RE (Bar)1.23 1.07 1.01 0.94 0.8B
DISC~AR~E
TEMPERAT~RE (C)120.8110,9 106.5 100.8 96.2 RET~RN GAS
TEMPERATURE ~C)20.020.0 20.I 20.1 20.1 VOLUMETRIC
FLOW (M3l3 x 102) 0.140 0.150 0.169 0.187 0.206 , . .
COOLING DUTY PER
UNIT SWEPT
VOL~ME (~Wtm3) 7I4 F67 592 534 485 ~-COEFFICIENT OF
PERFORMANCE 1.90 1.86 1.87 1.86 1.83 BOILING BP* -29.8 -26.2 -25.31-23.91 -21.90 POINT (C) DP~ -29.8_Z6.2 -25.07-23.51 -22.26 GLIDE IN _ EVAPORATOR (C) O O 0.2 0.2 0.2 * BP - Bubble Point ** DP - Dew Point 3~
21261~S 12 -REFRICER _ R-12 R-134a R-134alE-143a .. . .. . , _ .. . , . . _ .
~ ~Y WEIG~T 100 100 75125 50~50 25/75 .:
~ . ___ :' CONDENSER . :-:
PRESS~RE (Bar) 9 63 10.10 9.58 9 2D ~.85 -P~ESS~RE ( Bar ) 1. 23 1. 07 1. 02 1. 00 O.97 .. . - . . . . - . _ DISC~ARGE
TE~PERATURE (C) 120.8 110.9 110.0 107.5 105.1 ___ _ _-- .
R~T~RN GAS ~:
TE~PERAT~RE (C) 20.0 20.0 20.0 29.0 20.0 .
. . . - ... -............ :::VOLU~ETRIC
FLOW (M31~ s lOZ ) 0.140 0.150 0.162 0.170 0-176 . . . _ . . . . , -COOLI~G D~TY PE~
UNIT SWEPT
VOLUME ~W/m3) 714 667 617 588 56B
COEFFICIENT OF
PERFORMANCE 1.90 1.86 1.85 1.85 1.85 . . _ . . . ~ .
BOILING BP~ -29.8 -26.2 -25.61 -24.94 -24.45 POINT ~C) DP*~ -29.8 -26.2 -25.54 -24.88 -24.42 . . . _ GLIDE IN
EVAPORATOR (C) O O _ O i O
* BP D Bubb1e Point ** DP - Dew Point
Claims (14)
1. A refrigerant composition comprising a mixture of 1,1,1,2-tetrafluoroethane and at least one fluorinated ether selected from trifluoromethyl methyl ether and fluoromethyl trifluoromethyl ether.
2. A refrigerant composition as claimed in claim 1, characterised in that it comprises from 5 to 95 % by weight of 1,1,1,2-tetrafluoroethane and from 95 to 5 %
by weight of the ether component.
by weight of the ether component.
3. A refrigerant composition as claimed in claim 1 or claim 2, characterised in that is comprises a mixture of 1,1,1,2-tetrafluoroethane and fluoromethyl trifluoromethyl ether.
4. A refrigerant composition as claimed in claim 1 or claim 2, characterised in that it comprises a mixture of 1,1,1,2-tetrafluoroethane and trifluoromethyl methyl ether.
5. A refrigerant composition as claimed in claim 4, characterised in that it comprises from 5 to 75 % by weight of 1,1,1,2-tetrafluoroethane and from 95 to 25 %
by weight of trifluoromethyl methyl ether.
by weight of trifluoromethyl methyl ether.
6. A refrigerant composition as claimed in claim 5, characterised in that it comprises from 5 to 60 % by weight of 1,1,1,2-tetrafluoroethane and from 95 to 40 %
by weight of trifluoromethyl methyl ether.
by weight of trifluoromethyl methyl ether.
7. A refrigerant composition as claimed in claim 6, characterised in that it comprises from 25 to 50 % by weight of 1,1,1,2-tetrafluoroethane and from 75 to 50 %
by weight of trifluoromethyl methyl ether.
by weight of trifluoromethyl methyl ether.
8. A refrigerant composition as claimed in claim 4, characterised in that it comprises from 70 to 95 % by weight of 1,1,1,2-tetrafluoroethane and from 30 to 5 %
by weight of trifluoromethyl methyl ether.
by weight of trifluoromethyl methyl ether.
9. A refrigerant composition as claimed in claim 8, characterised in that it comprises from 70 to 85 % by weight of 1,1,1,2-tetrafluoroethane and from 30 to 15 %
by weight of trifluoromethyl methyl ether.
by weight of trifluoromethyl methyl ether.
10. A refrigerant composition as claimed in any one of the preceding claims 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.
11. A heat transfer device containing a refrigerant composition as claimed in any one of claims 1 to 10.
12. Use of a refrigerant composition as claimed in any one of claims 1 to 10 in a heat transfer device.
13. A method for providing cooling which comprises condensing the refrigerant composition claimed in any one of claims 1 to 10 and thereafter evaporating it in a heat exchange relationship with a body to be cooled.
14. A method for providing heating which comprises condensing the refrigerant composition claimed in any one of claims 1 to 10 in a heat exchange relationship with a body to be heated and thereafter evaporating it.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB929200521A GB9200521D0 (en) | 1992-01-10 | 1992-01-10 | Compositions useful as refrigerants |
| GB9200521.4 | 1992-01-10 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2126185A1 true CA2126185A1 (en) | 1993-07-22 |
Family
ID=10708415
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002126185A Abandoned CA2126185A1 (en) | 1992-01-10 | 1992-12-23 | Compositions useful as refrigerants |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP0620837A1 (en) |
| JP (1) | JPH07502774A (en) |
| KR (1) | KR940703902A (en) |
| AU (1) | AU666694B2 (en) |
| BR (1) | BR9207035A (en) |
| CA (1) | CA2126185A1 (en) |
| GB (1) | GB9200521D0 (en) |
| WO (1) | WO1993014173A1 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU668534B2 (en) * | 1991-12-03 | 1996-05-09 | United States Environmental Protection Agency | Refrigerant compositions and processes for using same |
| 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 |
| AU686129B2 (en) * | 1993-01-20 | 1998-02-05 | Imperial Chemical Industries Plc | Refrigerant compositions |
| DE69611930T3 (en) * | 1995-10-20 | 2010-05-20 | Minnesota Mining And Mfg. Co., Saint Paul | HYDROFLUORETHER AS LOW TEMPERATURE COOLANT |
| USRE37054E1 (en) | 1996-10-16 | 2001-02-20 | Minnesota Mining And Manufacturing Company | Secondary loop refrigeration system |
| US5819549A (en) * | 1996-10-16 | 1998-10-13 | Minnesota Mining And Manufacturing Company | Secondary loop refrigeration system |
| CN110591650B (en) * | 2019-09-12 | 2020-09-25 | 珠海格力电器股份有限公司 | Heat transfer composition suitable for centrifugal refrigerating unit |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4961321A (en) * | 1989-02-28 | 1990-10-09 | W. R. Grace & Co.-Conn. | Bis (difluoromethyl) ether refrigerant |
| ATE280194T1 (en) * | 1990-03-12 | 2004-11-15 | Du Pont | AZEOTROPIC COMPOSITION OF 1,1,1,2 TETRAFLUORETHANE AND DIMETHYL ETHER |
| 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 |
-
1992
- 1992-01-10 GB GB929200521A patent/GB9200521D0/en active Pending
- 1992-12-23 CA CA002126185A patent/CA2126185A1/en not_active Abandoned
- 1992-12-23 AU AU31687/93A patent/AU666694B2/en not_active Ceased
- 1992-12-23 BR BR9207035A patent/BR9207035A/en not_active Application Discontinuation
- 1992-12-23 EP EP93900352A patent/EP0620837A1/en not_active Withdrawn
- 1992-12-23 WO PCT/GB1992/002382 patent/WO1993014173A1/en not_active Application Discontinuation
- 1992-12-23 KR KR1019940702373A patent/KR940703902A/en not_active Application Discontinuation
- 1992-12-23 JP JP5512216A patent/JPH07502774A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| KR940703902A (en) | 1994-12-12 |
| BR9207035A (en) | 1995-12-06 |
| JPH07502774A (en) | 1995-03-23 |
| AU666694B2 (en) | 1996-02-22 |
| GB9200521D0 (en) | 1992-02-26 |
| WO1993014173A1 (en) | 1993-07-22 |
| AU3168793A (en) | 1993-08-03 |
| EP0620837A1 (en) | 1994-10-26 |
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