CA2227917A1 - Refrigerant compositions - Google Patents
Refrigerant compositions Download PDFInfo
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- CA2227917A1 CA2227917A1 CA 2227917 CA2227917A CA2227917A1 CA 2227917 A1 CA2227917 A1 CA 2227917A1 CA 2227917 CA2227917 CA 2227917 CA 2227917 A CA2227917 A CA 2227917A CA 2227917 A1 CA2227917 A1 CA 2227917A1
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- CA
- Canada
- Prior art keywords
- weight
- refrigerant composition
- azeotropic refrigerant
- refrigerant
- composition
- 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.)
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- 239000003507 refrigerant Substances 0.000 title claims abstract description 66
- 239000000203 mixture Substances 0.000 title claims abstract description 48
- RWRIWBAIICGTTQ-UHFFFAOYSA-N difluoromethane Chemical compound FCF RWRIWBAIICGTTQ-UHFFFAOYSA-N 0.000 claims abstract description 24
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims abstract description 20
- 229910002092 carbon dioxide Inorganic materials 0.000 claims abstract description 20
- GTLACDSXYULKMZ-UHFFFAOYSA-N pentafluoroethane Chemical compound FC(F)C(F)(F)F GTLACDSXYULKMZ-UHFFFAOYSA-N 0.000 claims abstract description 20
- 239000001569 carbon dioxide Substances 0.000 claims abstract description 10
- 238000005057 refrigeration Methods 0.000 claims description 15
- 150000002430 hydrocarbons Chemical class 0.000 claims description 9
- 229930195733 hydrocarbon Natural products 0.000 claims description 8
- OFBQJSOFQDEBGM-UHFFFAOYSA-N Pentane Chemical compound CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 claims description 6
- 239000004215 Carbon black (E152) Substances 0.000 claims description 5
- RJCQBQGAPKAMLL-UHFFFAOYSA-N bromotrifluoromethane Chemical compound FC(F)(F)Br RJCQBQGAPKAMLL-UHFFFAOYSA-N 0.000 claims description 5
- 238000001816 cooling Methods 0.000 claims description 5
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 claims description 4
- 239000013529 heat transfer fluid Substances 0.000 claims description 4
- 238000000034 method Methods 0.000 claims description 4
- 125000004432 carbon atom Chemical group C* 0.000 claims description 3
- 238000001704 evaporation Methods 0.000 claims description 2
- 239000001294 propane Substances 0.000 claims description 2
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 5
- 239000002253 acid Substances 0.000 description 5
- KYKAJFCTULSVSH-UHFFFAOYSA-N chloro(fluoro)methane Chemical class F[C]Cl KYKAJFCTULSVSH-UHFFFAOYSA-N 0.000 description 5
- 239000000314 lubricant Substances 0.000 description 5
- 150000007513 acids Chemical class 0.000 description 4
- 238000009835 boiling Methods 0.000 description 4
- 229920005862 polyol Polymers 0.000 description 4
- VOPWNXZWBYDODV-UHFFFAOYSA-N Chlorodifluoromethane Chemical compound FC(F)Cl VOPWNXZWBYDODV-UHFFFAOYSA-N 0.000 description 3
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 3
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 239000002199 base oil Substances 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- PXBRQCKWGAHEHS-UHFFFAOYSA-N dichlorodifluoromethane Chemical compound FC(F)(Cl)Cl PXBRQCKWGAHEHS-UHFFFAOYSA-N 0.000 description 3
- 150000002148 esters Chemical class 0.000 description 3
- 150000002334 glycols Chemical class 0.000 description 3
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 3
- -1 neopentyl polyol ester Chemical class 0.000 description 3
- LVGUZGTVOIAKKC-UHFFFAOYSA-N 1,1,1,2-tetrafluoroethane Chemical compound FCC(F)(F)F LVGUZGTVOIAKKC-UHFFFAOYSA-N 0.000 description 2
- RFCAUADVODFSLZ-UHFFFAOYSA-N 1-Chloro-1,1,2,2,2-pentafluoroethane Chemical compound FC(F)(F)C(F)(F)Cl RFCAUADVODFSLZ-UHFFFAOYSA-N 0.000 description 2
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 description 2
- 150000007933 aliphatic carboxylic acids Chemical class 0.000 description 2
- 125000001931 aliphatic group Chemical group 0.000 description 2
- 150000004996 alkyl benzenes Chemical class 0.000 description 2
- 235000019406 chloropentafluoroethane Nutrition 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000002480 mineral oil Substances 0.000 description 2
- WXZMFSXDPGVJKK-UHFFFAOYSA-N pentaerythritol Chemical compound OCC(CO)(CO)CO WXZMFSXDPGVJKK-UHFFFAOYSA-N 0.000 description 2
- 238000003786 synthesis reaction Methods 0.000 description 2
- PTJWCLYPVFJWMP-UHFFFAOYSA-N 2-[[3-hydroxy-2-[[3-hydroxy-2,2-bis(hydroxymethyl)propoxy]methyl]-2-(hydroxymethyl)propoxy]methyl]-2-(hydroxymethyl)propane-1,3-diol Chemical compound OCC(CO)(CO)COCC(CO)(CO)COCC(CO)(CO)CO PTJWCLYPVFJWMP-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 239000004340 Chloropentafluoroethane Substances 0.000 description 1
- 239000004338 Dichlorodifluoromethane Substances 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- OFOBLEOULBTSOW-UHFFFAOYSA-N Malonic acid Chemical compound OC(=O)CC(O)=O OFOBLEOULBTSOW-UHFFFAOYSA-N 0.000 description 1
- GOOHAUXETOMSMM-UHFFFAOYSA-N Propylene oxide Chemical compound CC1CO1 GOOHAUXETOMSMM-UHFFFAOYSA-N 0.000 description 1
- ZJCCRDAZUWHFQH-UHFFFAOYSA-N Trimethylolpropane Chemical compound CCC(CO)(CO)CO ZJCCRDAZUWHFQH-UHFFFAOYSA-N 0.000 description 1
- 238000004378 air conditioning Methods 0.000 description 1
- 150000001335 aliphatic alkanes Chemical class 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 150000001735 carboxylic acids Chemical class 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 235000019404 dichlorodifluoromethane Nutrition 0.000 description 1
- 125000001153 fluoro group Chemical group F* 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 231100000053 low toxicity Toxicity 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 235000010446 mineral oil Nutrition 0.000 description 1
- SLCVBVWXLSEKPL-UHFFFAOYSA-N neopentyl glycol Chemical compound OCC(C)(C)CO SLCVBVWXLSEKPL-UHFFFAOYSA-N 0.000 description 1
- 150000003077 polyols Chemical class 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 150000005846 sugar alcohols Polymers 0.000 description 1
- CYRMSUTZVYGINF-UHFFFAOYSA-N trichlorofluoromethane Chemical compound FC(Cl)(Cl)Cl CYRMSUTZVYGINF-UHFFFAOYSA-N 0.000 description 1
- 229940029284 trichlorofluoromethane Drugs 0.000 description 1
- QXJQHYBHAIHNGG-UHFFFAOYSA-N trimethylolethane Chemical compound OCC(C)(CO)CO QXJQHYBHAIHNGG-UHFFFAOYSA-N 0.000 description 1
- 238000009834 vaporization Methods 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K5/00—Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
- C09K5/02—Materials undergoing a change of physical state when used
- C09K5/04—Materials undergoing a change of physical state when used the change of state being from liquid to vapour or vice versa
- C09K5/041—Materials undergoing a change of physical state when used the change of state being from liquid to vapour or vice versa for compression-type refrigeration systems
- C09K5/044—Materials undergoing a change of physical state when used the change of state being from liquid to vapour or vice versa for compression-type refrigeration systems comprising halogenated compounds
- C09K5/045—Materials undergoing a change of physical state when used the change of state being from liquid to vapour or vice versa for compression-type refrigeration systems comprising halogenated compounds containing only fluorine as halogen
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K2205/00—Aspects relating to compounds used in compression type refrigeration systems
- C09K2205/10—Components
- C09K2205/106—Carbon dioxide
-
- 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
- C09K2205/34—The mixture being non-azeotropic
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)
- Lubricants (AREA)
Abstract
A non-azeotropic refrigerant composition is described comprising (A) carbon dioxide (CO2), (B) difluoromethane (R-32), and (C) pentafluoroethane (R-125).
Description
REFRIGERANT COMPOSITIONS
The present invention relates to non-azeotropic refrigerant compositions and more particularly to non-azeotropic refrigerant compositions which can be used in the low temperature refrigeration applications currently satisfied by bromotrifluoromethane (R-13Bl).
Heat transfer devices of the mechanical compression type such as refrigerators, freezers, 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 heat transfer fluid. The resulting vapour is then compressed and passes to a condenser where it condenses and gives off heat to another heat transfer fluid. The co~Pn~te is then 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 bromotrifluoromethane (refrigerant R-13Bl), trichlorofluoromethane (refrigerant R-ll), dichlorodifluoromethane (refrigerant R-12), chlorodifluoromethane (refrigerant R-22) and the azeotropic mixture of chlorodifluoromethane and chloropentafluoroethane (refrigerant R-115); the azeotrope being refrigerant R-502. Refrigerant R-13B1, for example, has been widely used in low temperature refrigeration applications.
However, the fully and partially halogenated chlorofluorocarbons have been implicated in the destruction of the earth's protective ozone layer and as a result the use and production thereof has been limited by international agreement.
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 low or 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.
Replacements for some of the chlorofluorocarbon refrigerants presently in use have already been developed. These replacement refrigerants tend to comprise selected hydrofluoro~lk~n~s~ i.e.
compounds which contain only carbon, hydrogen and fluorine atoms in their structure. Thus, refrigerant R-12 is generally being replaced by 1,1,1,2-tetrafluoroethane (R-134a).
Although suitable replacement refrigerants are available, there is always a need for new refrigerants having a low or zero ozone depletion potential that are capable of repl~cing the chlorofluorocarbon refrigerants presently in use such as R-13Bl.
The present invention provides a non-azeotropic refrigerant composition comprising a mixture of compounds having low or zero ozone depletion potentials which can be used in the low temperature refrigeration applications currently satisfied by refrigerant R-13Bl.
According to the present invention there is provided a non-azeotropic ~zeotropic) refrigerant composition comprising:
(A) carbon dioxide (C02); J
(B) difluoromethane (R-32); and (C) pentafluoroethane (R-125).
The zeotropic refrigerant composition of the invention comprises three separate components. The first component (component (A)) is carbon dioxide (C02) which exhibits a low temperature refrigeration action subliming at around -78.5~C. The second component (component (B)) is difluoromethane (R-32) which has a boiling point of around -51.6~C. The third component (component (C)) is pentafluoroethane (R-125) which has a boiling point of sround -48.5~C.
A preferred refrigerant composition of the invention in terms of its suitability as a replacement for refrigerant R-13Bl is one comprising from 2 to 15 Z by weight C02, from 25 to 50 Z by weight R-32 and from 40 to 65 Z by weight R-125.
A particularly preferred refrigerant composition of the invention in terms of its suitability as a replacement for refrigerant R-13Bl is one comprising from 5 to 12 Z by weight, more particularly from 8 to 12 2 by weight, C02, from 35 to 50 Z by weight, more particularly from 40 to 50 Z by weight, R-32 and from 40 to 55 Z by weight, more particularly from 40 to 50 Z by weight, R-125.
An especially preferred refrigerant composition of the invention is one comprising abou~ 10 Z by weight C02, about 43 Z by weight R-32 and about 47 Z by weight R-125.
The refrigerant composition of the invention may also be combined with one or more hydrocarbon compounds in an amount which is sufficient to allow the composition to transport a mineral oil or alkyl benzene type lubricant around a refrigeration circuit and return it to the compressor. In this way, inexpensive lubricants based on mineral oils or alkyl benzenes may be used to lubricate the compressor.
Suitable hydrocarbons for use with the refrigerant composition of the invention are those con~;n;ng from Z to 6 carbon atoms, with t hydrocarbons con~in;ng from 3 to 5 carbon atoms being preferred.
Propane and pentane are particularly preferred hydrocarbons, with pentane being especially preferred.
Where a hydrocarbon is combined with the refrigerant composition of the invention, it will preferably be present in an amount of from 1 to 10 Z by weight on the total weight of the refrigerant composition.
The refrigerant composition of the invention may also be used in combination with the types of lubricants which have been specially developed for use with hydrofluorocarbon based refrigerants. Such lubricants include those comprising a polyoxyalkylene-glycol base oil. Suitable polyoxyalkylene glycols include hydroxyl group initiated polyoxyalkylene glycols, e.g. ethylene and/or propylene oxide oligomerslpolymers initiated on mono- or polyhydric alcohols such as methanol, butanol, pentaerythritol and glycerol. Such polyoxyalkylene glycols may also be end-capped with suitable terminal groups such as alkyl, e.g. methyl groups. Another class of lubricants which have been developed for use with hydrofluorocarbon based refrigerants and which may be used in combination with the present refrigerant compositions are those comprising a neopentyl polyol ester base oil derived from the reaction of at least one neopentyl polyol and at least one aliphatic carboxylic acid or an esterifiable derivative thereof. Suitable neopentyl polyols for the formation of the ester base oil include pentaerythritol, polypentaerythritols such as di- and tripentaerythritol, trimethylol alkanes such as trimethylol ethane and trimethylol propane, and neopentyl glycol. The esters may be formed with linear and/or branched aliphatic carboxylic acids, such as linear and/or branched alkanoic acids. Preferred acids are selected from the C5_8, particularly the C5_7, linear alkanoic acids and the C5_l0, particularly the C5_9, branched alkanoic acids. A
minor proportion of an aliphatic polycarboxylic acid, e.g. an aliphatic dicarboxylic acid, may also be used in the synthesis of the ester in order to increase the viscosity thereof. Usually, the amount of the carboxylic acid(s) which is used in the synthesis will be f sufficient to esterify all of the hydroxyl groups contained in the 3 polyol, although residual hydroxyl functionality may be acceptable. ~~
The zeotropic refrigerant composition of the present invention may be used to provide the desired cooling in heat transfer devices such as low temperature refrigeration systems by a method which involves condensing the refrigerant composition and thereafter evaporating it in a heat PYch~nge relationship with a heat transfer fluid to be cooled. In particular, the refrigerant composition of the invention may be employed as a replacement for refrigerant R-13Bl in low temperature refrigeration applications.
The present invention is now illustrated but not limited with reference to the following example.
Example 1 The performance of five refrigerant compositions of the invention in a low temperature refrigeration cycle was investigated using standard refrigeration cycle analysis techniques in order to assess the suitability thereof as a replacement for R-13B1. The following refrigerant compositions were subjected to the cycle analysis:
(1) A composition comprising 10 Z by weight C02, 43 Z by weight R-32 and 47 Z by weight R-125.
~Z) A composition comprising 10 % by weight C02, 45 % by weight R-32 and 45 % by weight R-125.
(3) A composition comprising 5 Z by weight C02, 45.6 % by weight R-32 and 49.4 Z by weight R-125.
(4) A composition comprising 10 Z by weight C02, 36 Z by weight R-32 and 54 X by weight R-125.
(S) A composition comprising 10 Z by weight C02, 27 % by weight R-32 and 63 Z by weight R-125.
The following operating conditions were used in the cycle analysis.
?
i Mean Evaporator Temperature: -55~C
.
Mean Condenser Temperature:Z0~C
Amount of Superheat: 0~C
Amount of Subcooling: 0~C
Isentropic Compressor Efficiency: lO0 ~
Cooling Duty: l kW
The results of analysing the performance of the five refrigerant compositions in a low temperature refrigeration cyc~e using these operating conditions are given in Table l.
The performance parameters of the refrigerant compositions which are presented in Table l, i.e. condenser pressure, evaporator pressure, discharge temperature, refrigeration capacity (by which is meant the cooling duty achieved per unit swept volume of the compressor)~ coefficient of performance (COP) (by which is meant the ratio of cooling duty (refrigeration effect) achieved to mechanical energy supplied to the compressor), and the glides in the evaporator and condenser (the temperature range over which the refrigerant composition boils in the evaporator and condenses in the condenser), are all art recognised parameters.
The performance of refrigerant R-13Bl under the same operating conditions is also shown in Table l by way of comparison.
It is apparent from the results given in Table l that the performance of the refrigerant composition of the invention in a low temperature refrigeration cycle is such that it could make an acceptable replacement for refrigerant R-13Bl.
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._ t
The present invention relates to non-azeotropic refrigerant compositions and more particularly to non-azeotropic refrigerant compositions which can be used in the low temperature refrigeration applications currently satisfied by bromotrifluoromethane (R-13Bl).
Heat transfer devices of the mechanical compression type such as refrigerators, freezers, 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 heat transfer fluid. The resulting vapour is then compressed and passes to a condenser where it condenses and gives off heat to another heat transfer fluid. The co~Pn~te is then 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 bromotrifluoromethane (refrigerant R-13Bl), trichlorofluoromethane (refrigerant R-ll), dichlorodifluoromethane (refrigerant R-12), chlorodifluoromethane (refrigerant R-22) and the azeotropic mixture of chlorodifluoromethane and chloropentafluoroethane (refrigerant R-115); the azeotrope being refrigerant R-502. Refrigerant R-13B1, for example, has been widely used in low temperature refrigeration applications.
However, the fully and partially halogenated chlorofluorocarbons have been implicated in the destruction of the earth's protective ozone layer and as a result the use and production thereof has been limited by international agreement.
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 low or 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.
Replacements for some of the chlorofluorocarbon refrigerants presently in use have already been developed. These replacement refrigerants tend to comprise selected hydrofluoro~lk~n~s~ i.e.
compounds which contain only carbon, hydrogen and fluorine atoms in their structure. Thus, refrigerant R-12 is generally being replaced by 1,1,1,2-tetrafluoroethane (R-134a).
Although suitable replacement refrigerants are available, there is always a need for new refrigerants having a low or zero ozone depletion potential that are capable of repl~cing the chlorofluorocarbon refrigerants presently in use such as R-13Bl.
The present invention provides a non-azeotropic refrigerant composition comprising a mixture of compounds having low or zero ozone depletion potentials which can be used in the low temperature refrigeration applications currently satisfied by refrigerant R-13Bl.
According to the present invention there is provided a non-azeotropic ~zeotropic) refrigerant composition comprising:
(A) carbon dioxide (C02); J
(B) difluoromethane (R-32); and (C) pentafluoroethane (R-125).
The zeotropic refrigerant composition of the invention comprises three separate components. The first component (component (A)) is carbon dioxide (C02) which exhibits a low temperature refrigeration action subliming at around -78.5~C. The second component (component (B)) is difluoromethane (R-32) which has a boiling point of around -51.6~C. The third component (component (C)) is pentafluoroethane (R-125) which has a boiling point of sround -48.5~C.
A preferred refrigerant composition of the invention in terms of its suitability as a replacement for refrigerant R-13Bl is one comprising from 2 to 15 Z by weight C02, from 25 to 50 Z by weight R-32 and from 40 to 65 Z by weight R-125.
A particularly preferred refrigerant composition of the invention in terms of its suitability as a replacement for refrigerant R-13Bl is one comprising from 5 to 12 Z by weight, more particularly from 8 to 12 2 by weight, C02, from 35 to 50 Z by weight, more particularly from 40 to 50 Z by weight, R-32 and from 40 to 55 Z by weight, more particularly from 40 to 50 Z by weight, R-125.
An especially preferred refrigerant composition of the invention is one comprising abou~ 10 Z by weight C02, about 43 Z by weight R-32 and about 47 Z by weight R-125.
The refrigerant composition of the invention may also be combined with one or more hydrocarbon compounds in an amount which is sufficient to allow the composition to transport a mineral oil or alkyl benzene type lubricant around a refrigeration circuit and return it to the compressor. In this way, inexpensive lubricants based on mineral oils or alkyl benzenes may be used to lubricate the compressor.
Suitable hydrocarbons for use with the refrigerant composition of the invention are those con~;n;ng from Z to 6 carbon atoms, with t hydrocarbons con~in;ng from 3 to 5 carbon atoms being preferred.
Propane and pentane are particularly preferred hydrocarbons, with pentane being especially preferred.
Where a hydrocarbon is combined with the refrigerant composition of the invention, it will preferably be present in an amount of from 1 to 10 Z by weight on the total weight of the refrigerant composition.
The refrigerant composition of the invention may also be used in combination with the types of lubricants which have been specially developed for use with hydrofluorocarbon based refrigerants. Such lubricants include those comprising a polyoxyalkylene-glycol base oil. Suitable polyoxyalkylene glycols include hydroxyl group initiated polyoxyalkylene glycols, e.g. ethylene and/or propylene oxide oligomerslpolymers initiated on mono- or polyhydric alcohols such as methanol, butanol, pentaerythritol and glycerol. Such polyoxyalkylene glycols may also be end-capped with suitable terminal groups such as alkyl, e.g. methyl groups. Another class of lubricants which have been developed for use with hydrofluorocarbon based refrigerants and which may be used in combination with the present refrigerant compositions are those comprising a neopentyl polyol ester base oil derived from the reaction of at least one neopentyl polyol and at least one aliphatic carboxylic acid or an esterifiable derivative thereof. Suitable neopentyl polyols for the formation of the ester base oil include pentaerythritol, polypentaerythritols such as di- and tripentaerythritol, trimethylol alkanes such as trimethylol ethane and trimethylol propane, and neopentyl glycol. The esters may be formed with linear and/or branched aliphatic carboxylic acids, such as linear and/or branched alkanoic acids. Preferred acids are selected from the C5_8, particularly the C5_7, linear alkanoic acids and the C5_l0, particularly the C5_9, branched alkanoic acids. A
minor proportion of an aliphatic polycarboxylic acid, e.g. an aliphatic dicarboxylic acid, may also be used in the synthesis of the ester in order to increase the viscosity thereof. Usually, the amount of the carboxylic acid(s) which is used in the synthesis will be f sufficient to esterify all of the hydroxyl groups contained in the 3 polyol, although residual hydroxyl functionality may be acceptable. ~~
The zeotropic refrigerant composition of the present invention may be used to provide the desired cooling in heat transfer devices such as low temperature refrigeration systems by a method which involves condensing the refrigerant composition and thereafter evaporating it in a heat PYch~nge relationship with a heat transfer fluid to be cooled. In particular, the refrigerant composition of the invention may be employed as a replacement for refrigerant R-13Bl in low temperature refrigeration applications.
The present invention is now illustrated but not limited with reference to the following example.
Example 1 The performance of five refrigerant compositions of the invention in a low temperature refrigeration cycle was investigated using standard refrigeration cycle analysis techniques in order to assess the suitability thereof as a replacement for R-13B1. The following refrigerant compositions were subjected to the cycle analysis:
(1) A composition comprising 10 Z by weight C02, 43 Z by weight R-32 and 47 Z by weight R-125.
~Z) A composition comprising 10 % by weight C02, 45 % by weight R-32 and 45 % by weight R-125.
(3) A composition comprising 5 Z by weight C02, 45.6 % by weight R-32 and 49.4 Z by weight R-125.
(4) A composition comprising 10 Z by weight C02, 36 Z by weight R-32 and 54 X by weight R-125.
(S) A composition comprising 10 Z by weight C02, 27 % by weight R-32 and 63 Z by weight R-125.
The following operating conditions were used in the cycle analysis.
?
i Mean Evaporator Temperature: -55~C
.
Mean Condenser Temperature:Z0~C
Amount of Superheat: 0~C
Amount of Subcooling: 0~C
Isentropic Compressor Efficiency: lO0 ~
Cooling Duty: l kW
The results of analysing the performance of the five refrigerant compositions in a low temperature refrigeration cyc~e using these operating conditions are given in Table l.
The performance parameters of the refrigerant compositions which are presented in Table l, i.e. condenser pressure, evaporator pressure, discharge temperature, refrigeration capacity (by which is meant the cooling duty achieved per unit swept volume of the compressor)~ coefficient of performance (COP) (by which is meant the ratio of cooling duty (refrigeration effect) achieved to mechanical energy supplied to the compressor), and the glides in the evaporator and condenser (the temperature range over which the refrigerant composition boils in the evaporator and condenses in the condenser), are all art recognised parameters.
The performance of refrigerant R-13Bl under the same operating conditions is also shown in Table l by way of comparison.
It is apparent from the results given in Table l that the performance of the refrigerant composition of the invention in a low temperature refrigeration cycle is such that it could make an acceptable replacement for refrigerant R-13Bl.
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o ~ o 0 ~ o o o _i _ ~ o ~ o ~ o o o m O -I ' 0 J' O O o _ ~ 1 ~ C~ U ~
.8 Q ~3 . _ t 5~ _ o r ~
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.. ~ , ._ .
. ~:
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._ t
Claims (13)
1. A non-azeotropic refrigerant composition comprising:
(A) carbon dioxide (CO2);
(B) difluoromethane (R-32); and (C) pentafluoroethane (R-125).
(A) carbon dioxide (CO2);
(B) difluoromethane (R-32); and (C) pentafluoroethane (R-125).
2. A non-azeotropic refrigerant composition as claimed in claim 1 comprising from 2 to 15 % by weight CO2, from 25 to 50 % by weight R-32 and from 40 to 65 % by weight R-125.
3. A non-azeotropic refrigerant composition as claimed in claim 2 comprising from 5 to 12 % by weight CO2, from 35 to 50 % by weight R-32 and from 40 to 55 % by weight R-125.
4. A non-azeotropic refrigerant composition as claimed in claim 3 comprising from 8 to 12 % by weight CO2, from 40 to 50 % by weight R-32 and from 40 to 50 % by weight R-125.
5. A non-azeotropic refrigerant composition as claimed in claim 4 comprising about 10 % by weight CO2, about 43 % by weight R-32 and about 47 % by weight R-125.
6. A non-azeotropic refrigerant composition as claimed in any one of claims 1 to 5 which additionally comprises at least one hydrocarbon.
7. A non-azeotropic refrigerant composition as claimed in claim 6, wherein the at least one hydrocarbon contains from 2 to 6 carbon atoms.
8. A non-azeotropic refrigerant composition as claimed in claim 7, wherein the at least one hydrocarbon is selected from propane and pentane.
9. A non-azeotropic refrigerant composition as claimed in any one of claims 6 to 8, wherein the hydrocarbon is present in an amount of from 1 to 10 % by weight on the total weight of the refrigerant composition.
10. A heat transfer device containing a non-azeotropic refrigerant composition as claimed in any one of claims 1 to 9.
11. A low temperature refrigeration system containing a non-azeotropic refrigerant composition as claimed in any one of claims 1 to 9.
12. A method for providing cooling which comprises condensing a non-azeotropic refrigerant composition as claimed in any one of claims 1 to 9 and thereafter evaporating it in a heat exchange relationship with a heat transfer fluid to be cooled.
13. The use of a non-azeotropic refrigerant composition as claimed in any one of claims 1 to 9 as a replacement for refrigerant R-13B1 in low temperature refrigeration applications.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9516921.5 | 1995-08-18 | ||
| GBGB9516921.5A GB9516921D0 (en) | 1995-08-18 | 1995-08-18 | Refrigerant compositions |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2227917A1 true CA2227917A1 (en) | 1997-02-27 |
Family
ID=10779411
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2227917 Abandoned CA2227917A1 (en) | 1995-08-18 | 1996-08-12 | Refrigerant compositions |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0845021A1 (en) |
| JP (1) | JPH11511192A (en) |
| AU (1) | AU6746396A (en) |
| CA (1) | CA2227917A1 (en) |
| GB (1) | GB9516921D0 (en) |
| WO (1) | WO1997007181A1 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7238299B2 (en) * | 2002-11-01 | 2007-07-03 | Honeywell International Inc. | Heat transfer fluid comprising difluoromethane and carbon dioxide |
| US7655610B2 (en) | 2004-04-29 | 2010-02-02 | Honeywell International Inc. | Blowing agent compositions comprising fluorinated olefins and carbon dioxide |
| JP2008506885A (en) | 2004-07-13 | 2008-03-06 | タイアックス エルエルシー | Refrigeration system and refrigeration method |
| FR2910016B1 (en) * | 2006-12-19 | 2009-02-20 | Arkema France | COMPOSITIONS USEFUL AS REFRIGERANT FLUID |
| DE102016204378A1 (en) * | 2016-03-16 | 2017-09-21 | Weiss Umwelttechnik Gmbh | test chamber |
| DE102017012211A1 (en) | 2017-09-08 | 2019-03-14 | Technische Universität Dresden | refrigerant |
| DE102019105676B4 (en) * | 2019-03-06 | 2021-05-06 | Weiss Umwelttechnik Gmbh | Refrigerant and its use |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4116274C2 (en) * | 1991-05-17 | 1998-03-19 | Forschungszentrum Fuer Kaeltet | Refrigerant |
| DE69506550D1 (en) * | 1994-07-14 | 1999-01-21 | Du Pont | COOLING COMPOSITIONS |
-
1995
- 1995-08-18 GB GBGB9516921.5A patent/GB9516921D0/en active Pending
-
1996
- 1996-08-12 WO PCT/GB1996/001960 patent/WO1997007181A1/en not_active Application Discontinuation
- 1996-08-12 EP EP96927757A patent/EP0845021A1/en not_active Ceased
- 1996-08-12 AU AU67463/96A patent/AU6746396A/en not_active Abandoned
- 1996-08-12 CA CA 2227917 patent/CA2227917A1/en not_active Abandoned
- 1996-08-12 JP JP9509032A patent/JPH11511192A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| JPH11511192A (en) | 1999-09-28 |
| EP0845021A1 (en) | 1998-06-03 |
| AU6746396A (en) | 1997-03-12 |
| GB9516921D0 (en) | 1995-10-18 |
| WO1997007181A1 (en) | 1997-02-27 |
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