CA2161813C - Azeotrope-like compositions of pentafluoroethane and 1,1,1,-trifluoroethane - Google Patents
Azeotrope-like compositions of pentafluoroethane and 1,1,1,-trifluoroethane Download PDFInfo
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- 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
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- 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
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- 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
- C09K2205/32—The mixture being azeotropic
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Abstract
Azeotrope-like compositions comprising pentafluoroethane and 1,1,1-trifluoroethane are stable and have utility as refrigerants for heating and cooling.
Description
~WO 94126836 ~~g ~ ~ ~ ~ ~ PCTIU593104577 DESCRIPTION
' 5 AZEOTROPE-LIKE COMPOSITIONS OF
PENTAFLUOROETHANE AND 1,1,1-TRIFLUOROETHANE
Field of the Invention This invention relates to azeotrope-like or essentially constant-boiling mixtures of pentafluoroethane and 1,1,1-trifluoroethane. These mixtures are 'useful as refrigerants for heating and cooling.
CROSS-REFERENCE TO RELATED APPLICATION
Commonly assigned U.S. patent No. 4,944,388 discloses azeotrope-like mixtures of pentafluoroethane; 1,1,1-trifluoroethane; and chloradifluoromethane.
BACKGROUND OF THE INVENTION
Fluorocarbon based fluids have found widespread use in industry for refrigeration applications such as air conditioning and heat pump applications.
Vapor compression is one type of refrigeration. In its simplest farm, vapor compression involves changing the refrigerant from the liquid to the vapor phase through heat absorption at a low pressure and then from the vapor to the liquid phase through heat removal at an elevated pressure. First, the refrigerant is vaporized in the evaporator which is in contact with the body to be cooled. The pressure in the evaporator is such that the boiling point of the refrigerant is below the temperature of the body to be cooled. Thus, heat flows from the body to the refrigerant and causes vaporization. The formed vapor is then removed by means of a compressor in order to WO 94126836 '~ ~ ~ s3 PCT/US93J04577 maintain the Low pressure in the evaporator. The temperature and pressure of the vapor ate then raised through the addition of mechanical energy by the compressor. The high-pressure vapor then passes to the condenser whereupon heat exchange with a cooler medium.
the sensible and latent heats are removed with subsequent condensation. The hot liquid refrigerant then passes to the expansion valve and is ready to cycle again.
While the primary purpose of refrigeration is to remove energy at low temperature. the primary purpose of a heat pump is to add energy at higher temperature. Heat pumps ace considered reverse cycle systems because for heating. the operation of Lhe condenser is interchanged =5 with that of the refrigeration evaporator.
Certain chlorofluoromethane and chlorofluocoethane derivatives have gained widespread use in refrigeration applications including air conditioning and heat pump applications owing to their unique combination of chemical and physical properties.
The majority of refrigerants utilized in vapor compression systeis are either single components fluids or azeotropic aixtuses. The use o! azeotropic mixtures as refrigerants is known in the art; for example, see E. C.
Downing. FLUOSOC11SBONS SEPSIGES!lNTS H11PTDBOOK. Preatice-Hall. 1988 and U.S. Patents 2.101.993 sad 2.641.579.
S-502 is an azeotropic blend which consists of monochlorodifluoromethane(S-22) and chloropeatafluoro-ethane(S-115), a fully haloqenated chlorofluorocarbon.
S-502 has been routinely used for medius; to low temperature refrigeration applications.
~O 94/2683 ~ ~ $ ~ '~ PCT/U593104577 Azeotropic of azeotrope-like compositions are desired because they do not feactionate upon boiling.
This behavior is desirable because in the previously described vapor compression equipment with which these refrigeeants are employed, condensed material is generated in preparation for cooling or for heating purposes.
Unless the refrigerant composition exhibits a constant boiling point, i.e. is azeotrope-like, fractionation and segregation will occur upon evaporation and condensation and undesirable refrigerant distribution may act to upset the cooling or heating.
Non-azeotropic mixtures have bean disclosed as refrigerants for example in U. S. Patent 4.303.536 but have not found widespread use in commercial applications.
The use of non-azeotropic mixtures which fractionate during the refrigeration cycle introduces additional complexity info the system which necessitates hardware changes. The use o! non-azeottopic refrigerants has been avoided primarily due to the added difficulty is charging and servicing refrigeration equipaeat and the situation ie further coaplicated i! an inadvertent leak in the system oceurs duriaQ use or during service. The composition of the mixture could change atfectiag system pressures and systea pertoraance. If one coaponeat of the non-azeotropic aixture is damnable, then fractionation could shift the coaposition into the flammable region with potential adverse consequences.
The art is continually seeking new fluorocarbon based azeotrope-like mixtures which otter alternatives for . refrigeration and heat pump applications. Currently, of particular interest, ate fluorocarbon based azeotrope-like mixtures which are considered to be eavironaentally safe substitutes for the presently used lolly haloqenated - q _ chlorofluorocarbons(CFC's). The latter are suspected of causing environmental problems in connection with the earth's protective ozone layer.
The substitute mate. gals must also possess those properties unique to the CFC's including chemical stability, low toxicity, non-flammability, and efficiency in-use. The latter characteristic is important in refrigeration and air-conditioning especially where a loss in refrigerant thermodynamic pecformance or energy efficiency may have secondary environmental impacts through increased fossil fuel usage arising from an increased demand for electrical energy. Furthermore, the ideal CFC refrigerant substitute would not require major engineering changes to conventional vapor compression _ technology currently used with CFC relrigecants.
Mathematical modals have substantiated that hydrolluoro-carbons, such as pentalluoroethane(F~C-125) and 1,1,1-trilluoroethane(F~C-143a) will not adversely a!lect atmospheric cheaistry, being negligible contributors to ozone depletion and to green-house global warning in comparison to the fully haloqenated species.
Because t~C-143a is as e!licient as S-502 and provides a modest increase in refrigeration capacity.
IBC-143a aiQht be considered a good relriqerant substitute !ot S-502. aowever, a disadvantage o! t~C-143a as a relriQeraat is that the vapor of IBC-143a is flammable.
As a result, the shipping, handling, and use o! H!C-143a have to be carefully controlled due to the potential flamaability.
Because IiFC-125 is nonflammable and provides a ~
modest increase in refrigeration capacity coapared with H-502, FR~C-125 might be considered a good refrigerant ~O 94f26836 ~ PCT/U593104577 substitute for R-502.. However, a disadvantage of HFC-125 is that HFC-125 is about 5t less efficient than R-502.
It is an object of this invention to provide novel azeotrope-like compositions based on pentafluoroethane and 1.1.1-trifluoroethane which will not fractionate under normal cooling or heating conditions.
Another object of the invention is to provide novel environmentally acceptable refrigerants for use in the aforementioned applications.
Other objects and advantages of the invention will become apparent from the following description.
T»SC&IPTION OF THE INVENTION
Ia accordance with the invention, novel azeotrope-like compositions have been discovered comprising penta-fluoroethane and 1,1.1-trifluoroethane. The azeotrope-like compositions comprise from about 1 to about 80 weight peeceat peatafluoroethane and from about 20 to about 99 weight peccaat 1.1,1-trifluoroethane which have a vapor pressure of about 167 psia(1113 kPa) ~ about 6 psia(40 kPa) at 70'!(21.1'C). These compositions ate azeotrope-like because they ase constant-boiling, i.e. exhibit essentially constant-vapor pressure versus composition and essentially identical liquid and vapor cotpositions over the aforeasntionsd compositional canoes.
In a preferred embodiment of the invention, the azeotrope-like compositions of the invention coapcise from about 38.4 to about 80 weight percent pentafluoroethane and from about 20 to about 61.6 weight percent 1.1,1-trifluoroethane. Vapor phase compositions containing in .~ ~y ._ excess of about ~~ : ~ weigt'~t per~ec~xc pentaE ~.uoroe~.hane were determined to be nonflatQmable .n aic ac ,a~ab~enc ~onditians r.~sing the ATM F._~;s~, ~ethrad as s~seca.fiec~ ~n the ~meriran 'society of liea'Cing,. ~efri~;~erati.n, -tc~~ ~.~c...i~ondi~ic~nic~g I~ngirleecsa;A~~iR~E) Standar3~ 3.4.
In a most prat~arra~cl a~tb~~d~~ant of~ tha in~rantion"
the azeot~cope-like c~a~;pos~.ti~ans~ C>~ ~.he ic~,vention comprise from about 4o try abort ~o ~re~~ht pe~r~en~~ pentaflrJOroethane and from about 2C7 to about. ~ ire ~g~rt percent ~ . 1 , 1-trifluoroethane. "These cs~mpositio~'es are conetan~c-boiling, non-segregating, and nonf lammable,.
These most pce~erred a~eotrope--like compositions of the invention have a vapor pressure of about 16 ~~ psia ( 111 k p a ~ ~, a b o a t ~: p s °~. ~t ( ~ ~' k 1~ a: ~ ~ ~. -ar to ~ ~ ;~
F. ~~~, ° ~~' ~~ r A. k~lexud of ~I~'C 125 ixrn~ ~El~°t'. ~rx a.,r ~ur,~ ~:i.~ ~.x::,~~a<i ~.s kGr~ua.::xr~
utli.t~r as a. x~efryt.xa~~t°. aT. °~ty~;~:r~~wb~~i:~
T,rxit_~~.~ ~~v~c:,~ ~."~k'~lw;:rra'f'lsz~ax-oaG,~~,,ons As ~Zefric~ex-an~ts ~E~C ~~~u k~at~t: ~c:h.-. ~J'ei~iu~m~~ r~ ~:'~a... ~tesa-,ax°uh ~:?i~,cla~:uxe vatabase Number lS~itU2 (ke:~ea~<~:kx a:~a.:~<:.lu;~x~~.~ ;fr'ru~nal ~~'umbE:~r: 15~U2~.
~aublxshec~ Februar~.° ~..~'i '~ , K.~~nnt-=t:.h Ih9dsa~z k"..sta.~i ~.at:ians Ltd. " , trut Llais c3ise;i.osure implied t: hat= saah .i ~rl~~zi3 ~~~ .~~~r --a~;eotrofWc, i...e.
would fractiaaaatc= x~~rai: ~rr<~~rk~x°~,rc.i.~~~ ::rz ~~?n.~iarr~aa_ic::~~-, azict stateci that .::he blenr,~ was da. sadvaazty,~:~.~~e~»:r~:, F>ec;s.o~;e a.. t: ~rF~s f laanmalale . ~:arrtrar~r ~.a this teach:ingM we have ~~:is~ava::rr~ec~ t~aa~.. t:tza ~:le~~c3s of xIFC-2:~5 anCi t-IF~°_:3~~a a~ xwc~.t~WCa a~.~a~r~ ~~~"e a~rti~r . ::~~~, t ~:~.~
~,cr:a r~~_~~" i.,.~. .azeotr.,pe-~.ik~:, ~~tkc~ ara~ n~:..n~le~:~unalWr?..e.
'~"~Ui tll~~l "~'~IcC~~,,ra"~'w..~ ~k~'~ ',~~itd~ ~.~re~.tl, fob' t:h~
mixtures off' t:e ~"nvent~.orr ~reca~us~r ~.n t~r~r clai~ae~d propoxt~ons, the c~o>epositi~ons of ~aent~xiluocoett~ane and x,1,1--trif luoroett~ane acer constant ~,.bo~,l.inq oc essential l~r constant-boiling.
All composit~oa~s within tlhe indicat~c~ ranges, as ~5 well as certain compositions outside rrt~e in~l~cate~cl ranges, are azeatcop~r-li~c~a, ae d~e~ined moce pacticulac:ly below.
~y 2~.6~8~.3 wW0 94/26836 PCTlUS93I04577 From fundamental principles. the thermodynamic state of a fluid is defined by four variables: pressure, temperature, liquid composition and vapor composition. or P-T-X-Y, respectively. An azeotrope ie a unique characteristic of a system of two or more components where X and Y are equal at the stated P and T. In practice.
this means that the components of a mixture cannot be separated during a phase change, and therefore are useful in the cooling and heating applications as described above.
For the purpose of this discussion, azeotrope-like composition is intended to mean that the composition behaves like an azeotrope, i.e. hae constant-boiling charactecistics or a tendency not to fractionate upon boiling oc evaporation. Thus, in such compositions. the composition of the vapor formed during boiling or evaporation is identical or substantially identical to the original liquid composition. Hence, during boiling or evaporation. the liquid composition. if it changes at a11, changes only to a minimal or negligible extant. This is to be contrasted with non-azeottope-like compositions in which during boiling or evaporation, the liquid composition changes to a substantial degree.
Thus, one way to detecmine whether a candidate mixture is ~azeotropo-like" within the meaning of this invention. is to distill a sample thereo! under conditions (i.e. resolution - nusber of plates) which would be expected to separate the mixture into its separate components. I! the mixture is non-azeotropic or noa-azeotrope-like, the mixture will fractionate, i.e.
separate into its various components with the lowest boiling component distilling off first, and so on. if the mixture is azeotropo-like, some finite a~ouat of a first distillation cut will be obtained which contains all of WO 94/26836 - '$ PCTIUS93104577 the mixture components and which is constant-boiling or behaves as a single substance. This phenomenon cannot occur if the mixture is not azeotrope-Like i.e., it is not part of an azeotropic system.
S
It follows from the above that a~othec characteristic of azeotrope-like compositions is that there is a range of compositions containing the same components in varying proportions which ate azeotrope~like oc constant-boiling. All such compositions are intended to be covered by the Cerm azeotrope-like or constant-boiling as used herein. As an example. it is well known that at differing pressures, the composition of a given azeotrope will vary at least slightly as does the boiling point of the composition. Thus. an azeotrope of A and B
represents a unique type o! relationship but with a variable composition depending on temperature and/or pressure. As is readily understood by parsons skilled in the art, the boiling point of the azeottope will vary with the pressure.
In one process embodiment o! the invention, the azeotrope-like compositions o! the invention may be used in a method !or producing refrigeration which comprises condensing a refrigerant coaprisiag the azeotrope-like compositions and thereafter evaporating the refrigerant in the vicinity o! a body to be cooled.
In another process embodiment o! the invention, the azeotrops-like cosipositions o! the invention nay be used in a method !or producing heating which comprises condensing a refrigerant comprising the azeotrope-like compositions is the vicinity o! a body to be heated and thereafter evaporating the refrigerant.
~WO 94126836 ~ ~ ~ ~ ~ PCT1US93104577 The pentafluoroethane and 1.1.1-trifluoroethane of the novel azeotrope-like compositions of the invention are known materials. Preferably. the materials should be used in sufficiently high purity so as to avoid the introduction of adverse influences upon the cooling or , heating properties or constant-boiling properties of the system.
It should be understood that the present compositions may include additional components so as to form new azeotrope-like compositions. Any such compositions are considered to be within the scope of the present invention as long as the compositions ate constant-boilinq or essentially constant-boiling and contain all of the essential components described herein.
The present invention is more fully illustrated by the following non-limiting Examples.
Fi7CAMPLE 1 Thls exaaple shows that certain compositions of pentafluoroethane and 1.1,1-trifluoroethano era azeotrope-like, i.a. exhibit essentially identical liquid and vapor compositions, and are constant-boiling, i.e. ezhibit essentially constant vapor pressure versus composition within this tango.
Vapor liquid equilibrium ezpaciments were performed by preparing aiztures of FCC-125 and FTfC-143a in as approzimauly 150 cubic centimeter vessel. The vessel.
equipped with a naqneticaliy driven stirrer and a 0-300 psia(0-2068 kPa) pressure transducer accurate to +0.23, was submerged in a constant temperature bath controlled to within ~0.05°F(0.03~C). Once thermal equilibrium was WO 94126836 _ ~ ~ ~ ~ ~ ~ PCTIUS93104577 attained, as determined by constant vapor pressure readings, vapor and liquid samples were withdrawn from the vessel and analyzed by standard gas chromatographic techniques. This procedure was repeated at three nominal .
5r compositions of about 25. 50, and 75 weight percent HFC-125 in HFC-143a, and at three temperatures of _ -10°F(-Z3.3°C). 70°F(21.1°C), and 112.5°F(44.7°C). Table I summarizes the results of these experiments. In Table I, the compositions are in weight percent HFC-125 in HFC_143a.
TABLE I
VAPOR LIOUTD EOUILIBRIA DATA
Liquid Composition Yapor Composition Tomparaturo lei8ht Porconta8a(iloi8ht Porca~tasoVspor Pressure C ltlC-125) tilC-125) osia(kPa) -10.0(-23.3) 0.0 0.0 40.2(268) -10.0(-23.3) 22.4 22.1 40.1(261) -10.0(-23.3) 51.2 52.0 40.1(261) -10.0(-23.3)76.1 77.0 41.0(273) -I0.0(-23.3) 100.0 100.0 43.5(290) 70.0(21.1) 0.0 0.0 165.2(1101) 70.0<21.1) 22.5 22.8 165.2(1101) 70.0(21.1) 51.0 52.3 167.1(1114) 70.0(21.1) 76.0 77.7 171.6(1144) 700(21.1) 100.0 100.0 180.0(1200) 112.5(44.7) 0.0 0.0 297.9(1986) 112.5(44.7) 22.4 23.1 299.2(1995) 112.5(A4.7) 50.9 50.6 300.9(2006) 112.5(44.7) 7i.2 78.0 309.9(2066) 112.5(44.7) 100.0 100.0 326.0(2173) The data shown in Table I indicate that the vapor and liquid compositions are essentially identical within the experimental uncertainty o! ~1.0 weight percent unit ' associated with the chromatographic analysis. The vapor pressures of the blends ate essentially constant to within _+2s over the composition range from about 1 to about SO
weight percent HFC-125 and from about 99 to about 20 weight percent FTFC-143a, i.e. these blends are constant-boiling or azeottope-like.
~VO 9412683 ~ ~ ~ ~ ~ ~ 3 PCTIUS93104577 This example shows that certain HFC-125/HFC-143a r blends are nonflammable.
Flammability measurements were performed using the ASTM E-681 technique modified according to ASHRAE Standard 34. Briefly, this technique involves preparing fluorocarbon/air gas mixtures to a total pressure of one atmosphere(l~lkPa) in a 5-liter spherical glass vessel, stirring the mixture with a magnetically driven propeller to ensure a uniform composition, and then attempting to ignite the mixture using an electrically activated kitchen match head as the ignition source. A ternary flammability diagram was mapped by preparing mixtures of HFC-125.
HFC-143a, and air by the method of partial pressures and then determiniaQ whether or not a flaae would propagate as defined by ASTM E-681. The critical flammability composition, i.e. the composition of the HFC-125/HFC-143a blend which contains the maximum proportion of the flammable HFC-143a but does not exhibit flame limits in air, was determined fa a graphical manner siailar to that described is Haenai et a1, Industrial and Encineeriaa ~heaistrv ~. 695(1959). The critical flaamability composition was found to be 61.6 weight percent HFC-143a sad about 38.4 weight percent H1~C-135. in other words, blends of IBC-125 and HPC-143a containing 38.4 or more woiQht percent HFC-125 ate nonflammable in all proportions in air at ambient conditions.
~]CAMPLE 3 This example shows that a bland of 50 weight percent HPC-125 and 50 weight percent FZEC-143a undergoes essentially no fractionation and maintains a constant-vapor pressure during a vapor leak which illustrates one advantage of a constant-boiling or azeotrope-like composition.
The vessel described in Example 1 was charged with approximately 105 grams of a 50/50 weight percent mixture of HFC-125 and HFC-143a. Vapor was allowed to leak from this container until about 14 weight percent of the ociginal charge had dissipated, at which point the vapor pressure of the remaining liquid was measured and a vapor phase sample collected for analysis. The vapor leak was continued until 80s of the original charge had dissipated;
additional vapor samples were taken for analysis at different stages during the leak. The temperature of the ~esael was maintained at 70°F(21.1°C) during the leak.
Vapor pressure and composition data are reported in Table II. In Table II, the composition is in weight percent H8C-125 is HFC-143a.
TABLE II
1'RACTIONATION DATA
Parcntt Vapor Pnssura Yspor Composition pissivstion vsia<kPa) (iisishi Pvrea~t !~C-125) 0.0 1f7.3(1115) 50.0 1.4 167.0(1113) S0.
31.7 166.2(1108) 19.8 1.5 165.1(1103) 19.6 f1.3 161.7(1091) 41.1 79.9 163.3(1089) 1.1 R~sidu~ liquid 11.6 E~sidu~ vapor 4E.6 The data listed in Table II show that the composition of the aiaure varies by no sore than 1.2 weight percent and that the vapor pressure resains constant within 4psia (27 kPa) or about 2. SS o! the total pressure.
~'VO 9412683 PCTlUS93104577 ExAMPLE 4 This example shows that constant-boiling HFC-125/
., HFC-143a blends have certain advantages when compared to other refrigerants which are currently used in certain ~ refrigeration cycles.
The theoretical performance of a refrigerant at specific operating conditions can be estimated from the:
thermodynamic properties of the refrigerant using standard refrigeration cycle analysis techniques; see for example, R. C. Downing. FLUOROCARBONS REFRIGERANTS HANDBOOK.
Chapter 3, Prentice-Hall, 1988. The coefficient of perfotmance(COP) is a universally accepted measure, especially useful is cepresentiag the relative thermodynamic efficiency of a refrigerant is a specific heating or cooling cycle involving evaporation or coadensatioa o! the reftiqeraat. In refrigeration engineering, this term expresses the ratio of useful refrigeration to the energy applied by the compressor in compressing the vapor. The capacity of a refrigerant represents the voluaetric effectiveness of the refrigerant. To a coapressor engineer, this value expresses the capability of a compressor to pump quantities of heat for a given voluaetric floe rata of reftiqeraat. Ia other words, given a specific compressor, a refrigerant with a higher capacity will deliver more cooling of heating power.
We have performed this type of calculation for a medium to low teaperature refrigeration cycle where the condenser tenpetature is typically 100~1~(38'C) and the evapoeatoc teaperature is typically -40 to -10~!(-~0 to -23.3'C). We have further assuaed iseatropic coapression and a compressor inlet temperature of 65~P(18.3~C). Such calculations ware performed for a 60/40 by weight percent WO 94126836 ~, ~ ~ ~ ~ ~ '~ PCTlUS93104577 blend of HFC-125 and HFC-143a as well as for R-502. Table III lists the COP of a 60/40 blend of HFC-125 and HFC-143a relative to that of R-502 over a range of evaporator temperatures. In Table III. the * indicates that COP and capacity ace given relative to R-502.
TABLE III
THERMODYNAMIC PERFORMANCE
R-502 1251113a Evaporator Discharsa DischarEo T~. Tamp. Tune.
'F 'C COp* Canacitv* 'F 'C 'F 'C
-40(-10) 1.01 1.08 235(113) 213(101) -30(-3) 1.00 1.01 220(l0A) 200(93) -20(-29) 0.99 1.07 205(96) 189(87) -10(-23) 0.99 1.06 192(89) 177(81) The data listed in Table III show that the HFC-125/HFC-143a bland provides essentially the sane COP(within ~ii) as that attainable with E-502, provides about a 7: increase in refriQetation capacity, and also products lower discharge teapecatures frog the coapressor.
which contributes to coapressor reliability. It has been recoaaended that coapressor discharge teaperatuces be liaited to about 225~T(107.2~C). This teaperature is exceeded in the current exaaple by 8-502 at evaporator teaperatures lower than -35~F(-37.2~C): the HEC-125/
H!C-143a blend can operate down to as evaporator teaperature of -50~F(-45.6~C) before exceeding the 225~r(107.2~C) discharge teaperature liait. Even cower evaporator teaperatures could be accoaplished by enriching the H8C-125 component up to 80i of the total aixture.
without significant iapact on the perforaance.
Having described the invention in detail and by reference to preferred embodiments thereof, it will be ~O 94126836 ~ ~ 3 PCT/US93104577 apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims.
S
' 5 AZEOTROPE-LIKE COMPOSITIONS OF
PENTAFLUOROETHANE AND 1,1,1-TRIFLUOROETHANE
Field of the Invention This invention relates to azeotrope-like or essentially constant-boiling mixtures of pentafluoroethane and 1,1,1-trifluoroethane. These mixtures are 'useful as refrigerants for heating and cooling.
CROSS-REFERENCE TO RELATED APPLICATION
Commonly assigned U.S. patent No. 4,944,388 discloses azeotrope-like mixtures of pentafluoroethane; 1,1,1-trifluoroethane; and chloradifluoromethane.
BACKGROUND OF THE INVENTION
Fluorocarbon based fluids have found widespread use in industry for refrigeration applications such as air conditioning and heat pump applications.
Vapor compression is one type of refrigeration. In its simplest farm, vapor compression involves changing the refrigerant from the liquid to the vapor phase through heat absorption at a low pressure and then from the vapor to the liquid phase through heat removal at an elevated pressure. First, the refrigerant is vaporized in the evaporator which is in contact with the body to be cooled. The pressure in the evaporator is such that the boiling point of the refrigerant is below the temperature of the body to be cooled. Thus, heat flows from the body to the refrigerant and causes vaporization. The formed vapor is then removed by means of a compressor in order to WO 94126836 '~ ~ ~ s3 PCT/US93J04577 maintain the Low pressure in the evaporator. The temperature and pressure of the vapor ate then raised through the addition of mechanical energy by the compressor. The high-pressure vapor then passes to the condenser whereupon heat exchange with a cooler medium.
the sensible and latent heats are removed with subsequent condensation. The hot liquid refrigerant then passes to the expansion valve and is ready to cycle again.
While the primary purpose of refrigeration is to remove energy at low temperature. the primary purpose of a heat pump is to add energy at higher temperature. Heat pumps ace considered reverse cycle systems because for heating. the operation of Lhe condenser is interchanged =5 with that of the refrigeration evaporator.
Certain chlorofluoromethane and chlorofluocoethane derivatives have gained widespread use in refrigeration applications including air conditioning and heat pump applications owing to their unique combination of chemical and physical properties.
The majority of refrigerants utilized in vapor compression systeis are either single components fluids or azeotropic aixtuses. The use o! azeotropic mixtures as refrigerants is known in the art; for example, see E. C.
Downing. FLUOSOC11SBONS SEPSIGES!lNTS H11PTDBOOK. Preatice-Hall. 1988 and U.S. Patents 2.101.993 sad 2.641.579.
S-502 is an azeotropic blend which consists of monochlorodifluoromethane(S-22) and chloropeatafluoro-ethane(S-115), a fully haloqenated chlorofluorocarbon.
S-502 has been routinely used for medius; to low temperature refrigeration applications.
~O 94/2683 ~ ~ $ ~ '~ PCT/U593104577 Azeotropic of azeotrope-like compositions are desired because they do not feactionate upon boiling.
This behavior is desirable because in the previously described vapor compression equipment with which these refrigeeants are employed, condensed material is generated in preparation for cooling or for heating purposes.
Unless the refrigerant composition exhibits a constant boiling point, i.e. is azeotrope-like, fractionation and segregation will occur upon evaporation and condensation and undesirable refrigerant distribution may act to upset the cooling or heating.
Non-azeotropic mixtures have bean disclosed as refrigerants for example in U. S. Patent 4.303.536 but have not found widespread use in commercial applications.
The use of non-azeotropic mixtures which fractionate during the refrigeration cycle introduces additional complexity info the system which necessitates hardware changes. The use o! non-azeottopic refrigerants has been avoided primarily due to the added difficulty is charging and servicing refrigeration equipaeat and the situation ie further coaplicated i! an inadvertent leak in the system oceurs duriaQ use or during service. The composition of the mixture could change atfectiag system pressures and systea pertoraance. If one coaponeat of the non-azeotropic aixture is damnable, then fractionation could shift the coaposition into the flammable region with potential adverse consequences.
The art is continually seeking new fluorocarbon based azeotrope-like mixtures which otter alternatives for . refrigeration and heat pump applications. Currently, of particular interest, ate fluorocarbon based azeotrope-like mixtures which are considered to be eavironaentally safe substitutes for the presently used lolly haloqenated - q _ chlorofluorocarbons(CFC's). The latter are suspected of causing environmental problems in connection with the earth's protective ozone layer.
The substitute mate. gals must also possess those properties unique to the CFC's including chemical stability, low toxicity, non-flammability, and efficiency in-use. The latter characteristic is important in refrigeration and air-conditioning especially where a loss in refrigerant thermodynamic pecformance or energy efficiency may have secondary environmental impacts through increased fossil fuel usage arising from an increased demand for electrical energy. Furthermore, the ideal CFC refrigerant substitute would not require major engineering changes to conventional vapor compression _ technology currently used with CFC relrigecants.
Mathematical modals have substantiated that hydrolluoro-carbons, such as pentalluoroethane(F~C-125) and 1,1,1-trilluoroethane(F~C-143a) will not adversely a!lect atmospheric cheaistry, being negligible contributors to ozone depletion and to green-house global warning in comparison to the fully haloqenated species.
Because t~C-143a is as e!licient as S-502 and provides a modest increase in refrigeration capacity.
IBC-143a aiQht be considered a good relriqerant substitute !ot S-502. aowever, a disadvantage o! t~C-143a as a relriQeraat is that the vapor of IBC-143a is flammable.
As a result, the shipping, handling, and use o! H!C-143a have to be carefully controlled due to the potential flamaability.
Because IiFC-125 is nonflammable and provides a ~
modest increase in refrigeration capacity coapared with H-502, FR~C-125 might be considered a good refrigerant ~O 94f26836 ~ PCT/U593104577 substitute for R-502.. However, a disadvantage of HFC-125 is that HFC-125 is about 5t less efficient than R-502.
It is an object of this invention to provide novel azeotrope-like compositions based on pentafluoroethane and 1.1.1-trifluoroethane which will not fractionate under normal cooling or heating conditions.
Another object of the invention is to provide novel environmentally acceptable refrigerants for use in the aforementioned applications.
Other objects and advantages of the invention will become apparent from the following description.
T»SC&IPTION OF THE INVENTION
Ia accordance with the invention, novel azeotrope-like compositions have been discovered comprising penta-fluoroethane and 1,1.1-trifluoroethane. The azeotrope-like compositions comprise from about 1 to about 80 weight peeceat peatafluoroethane and from about 20 to about 99 weight peccaat 1.1,1-trifluoroethane which have a vapor pressure of about 167 psia(1113 kPa) ~ about 6 psia(40 kPa) at 70'!(21.1'C). These compositions ate azeotrope-like because they ase constant-boiling, i.e. exhibit essentially constant-vapor pressure versus composition and essentially identical liquid and vapor cotpositions over the aforeasntionsd compositional canoes.
In a preferred embodiment of the invention, the azeotrope-like compositions of the invention coapcise from about 38.4 to about 80 weight percent pentafluoroethane and from about 20 to about 61.6 weight percent 1.1,1-trifluoroethane. Vapor phase compositions containing in .~ ~y ._ excess of about ~~ : ~ weigt'~t per~ec~xc pentaE ~.uoroe~.hane were determined to be nonflatQmable .n aic ac ,a~ab~enc ~onditians r.~sing the ATM F._~;s~, ~ethrad as s~seca.fiec~ ~n the ~meriran 'society of liea'Cing,. ~efri~;~erati.n, -tc~~ ~.~c...i~ondi~ic~nic~g I~ngirleecsa;A~~iR~E) Standar3~ 3.4.
In a most prat~arra~cl a~tb~~d~~ant of~ tha in~rantion"
the azeot~cope-like c~a~;pos~.ti~ans~ C>~ ~.he ic~,vention comprise from about 4o try abort ~o ~re~~ht pe~r~en~~ pentaflrJOroethane and from about 2C7 to about. ~ ire ~g~rt percent ~ . 1 , 1-trifluoroethane. "These cs~mpositio~'es are conetan~c-boiling, non-segregating, and nonf lammable,.
These most pce~erred a~eotrope--like compositions of the invention have a vapor pressure of about 16 ~~ psia ( 111 k p a ~ ~, a b o a t ~: p s °~. ~t ( ~ ~' k 1~ a: ~ ~ ~. -ar to ~ ~ ;~
F. ~~~, ° ~~' ~~ r A. k~lexud of ~I~'C 125 ixrn~ ~El~°t'. ~rx a.,r ~ur,~ ~:i.~ ~.x::,~~a<i ~.s kGr~ua.::xr~
utli.t~r as a. x~efryt.xa~~t°. aT. °~ty~;~:r~~wb~~i:~
T,rxit_~~.~ ~~v~c:,~ ~."~k'~lw;:rra'f'lsz~ax-oaG,~~,,ons As ~Zefric~ex-an~ts ~E~C ~~~u k~at~t: ~c:h.-. ~J'ei~iu~m~~ r~ ~:'~a... ~tesa-,ax°uh ~:?i~,cla~:uxe vatabase Number lS~itU2 (ke:~ea~<~:kx a:~a.:~<:.lu;~x~~.~ ;fr'ru~nal ~~'umbE:~r: 15~U2~.
~aublxshec~ Februar~.° ~..~'i '~ , K.~~nnt-=t:.h Ih9dsa~z k"..sta.~i ~.at:ians Ltd. " , trut Llais c3ise;i.osure implied t: hat= saah .i ~rl~~zi3 ~~~ .~~~r --a~;eotrofWc, i...e.
would fractiaaaatc= x~~rai: ~rr<~~rk~x°~,rc.i.~~~ ::rz ~~?n.~iarr~aa_ic::~~-, azict stateci that .::he blenr,~ was da. sadvaazty,~:~.~~e~»:r~:, F>ec;s.o~;e a.. t: ~rF~s f laanmalale . ~:arrtrar~r ~.a this teach:ingM we have ~~:is~ava::rr~ec~ t~aa~.. t:tza ~:le~~c3s of xIFC-2:~5 anCi t-IF~°_:3~~a a~ xwc~.t~WCa a~.~a~r~ ~~~"e a~rti~r . ::~~~, t ~:~.~
~,cr:a r~~_~~" i.,.~. .azeotr.,pe-~.ik~:, ~~tkc~ ara~ n~:..n~le~:~unalWr?..e.
'~"~Ui tll~~l "~'~IcC~~,,ra"~'w..~ ~k~'~ ',~~itd~ ~.~re~.tl, fob' t:h~
mixtures off' t:e ~"nvent~.orr ~reca~us~r ~.n t~r~r clai~ae~d propoxt~ons, the c~o>epositi~ons of ~aent~xiluocoett~ane and x,1,1--trif luoroett~ane acer constant ~,.bo~,l.inq oc essential l~r constant-boiling.
All composit~oa~s within tlhe indicat~c~ ranges, as ~5 well as certain compositions outside rrt~e in~l~cate~cl ranges, are azeatcop~r-li~c~a, ae d~e~ined moce pacticulac:ly below.
~y 2~.6~8~.3 wW0 94/26836 PCTlUS93I04577 From fundamental principles. the thermodynamic state of a fluid is defined by four variables: pressure, temperature, liquid composition and vapor composition. or P-T-X-Y, respectively. An azeotrope ie a unique characteristic of a system of two or more components where X and Y are equal at the stated P and T. In practice.
this means that the components of a mixture cannot be separated during a phase change, and therefore are useful in the cooling and heating applications as described above.
For the purpose of this discussion, azeotrope-like composition is intended to mean that the composition behaves like an azeotrope, i.e. hae constant-boiling charactecistics or a tendency not to fractionate upon boiling oc evaporation. Thus, in such compositions. the composition of the vapor formed during boiling or evaporation is identical or substantially identical to the original liquid composition. Hence, during boiling or evaporation. the liquid composition. if it changes at a11, changes only to a minimal or negligible extant. This is to be contrasted with non-azeottope-like compositions in which during boiling or evaporation, the liquid composition changes to a substantial degree.
Thus, one way to detecmine whether a candidate mixture is ~azeotropo-like" within the meaning of this invention. is to distill a sample thereo! under conditions (i.e. resolution - nusber of plates) which would be expected to separate the mixture into its separate components. I! the mixture is non-azeotropic or noa-azeotrope-like, the mixture will fractionate, i.e.
separate into its various components with the lowest boiling component distilling off first, and so on. if the mixture is azeotropo-like, some finite a~ouat of a first distillation cut will be obtained which contains all of WO 94/26836 - '$ PCTIUS93104577 the mixture components and which is constant-boiling or behaves as a single substance. This phenomenon cannot occur if the mixture is not azeotrope-Like i.e., it is not part of an azeotropic system.
S
It follows from the above that a~othec characteristic of azeotrope-like compositions is that there is a range of compositions containing the same components in varying proportions which ate azeotrope~like oc constant-boiling. All such compositions are intended to be covered by the Cerm azeotrope-like or constant-boiling as used herein. As an example. it is well known that at differing pressures, the composition of a given azeotrope will vary at least slightly as does the boiling point of the composition. Thus. an azeotrope of A and B
represents a unique type o! relationship but with a variable composition depending on temperature and/or pressure. As is readily understood by parsons skilled in the art, the boiling point of the azeottope will vary with the pressure.
In one process embodiment o! the invention, the azeotrope-like compositions o! the invention may be used in a method !or producing refrigeration which comprises condensing a refrigerant coaprisiag the azeotrope-like compositions and thereafter evaporating the refrigerant in the vicinity o! a body to be cooled.
In another process embodiment o! the invention, the azeotrops-like cosipositions o! the invention nay be used in a method !or producing heating which comprises condensing a refrigerant comprising the azeotrope-like compositions is the vicinity o! a body to be heated and thereafter evaporating the refrigerant.
~WO 94126836 ~ ~ ~ ~ ~ PCT1US93104577 The pentafluoroethane and 1.1.1-trifluoroethane of the novel azeotrope-like compositions of the invention are known materials. Preferably. the materials should be used in sufficiently high purity so as to avoid the introduction of adverse influences upon the cooling or , heating properties or constant-boiling properties of the system.
It should be understood that the present compositions may include additional components so as to form new azeotrope-like compositions. Any such compositions are considered to be within the scope of the present invention as long as the compositions ate constant-boilinq or essentially constant-boiling and contain all of the essential components described herein.
The present invention is more fully illustrated by the following non-limiting Examples.
Fi7CAMPLE 1 Thls exaaple shows that certain compositions of pentafluoroethane and 1.1,1-trifluoroethano era azeotrope-like, i.a. exhibit essentially identical liquid and vapor compositions, and are constant-boiling, i.e. ezhibit essentially constant vapor pressure versus composition within this tango.
Vapor liquid equilibrium ezpaciments were performed by preparing aiztures of FCC-125 and FTfC-143a in as approzimauly 150 cubic centimeter vessel. The vessel.
equipped with a naqneticaliy driven stirrer and a 0-300 psia(0-2068 kPa) pressure transducer accurate to +0.23, was submerged in a constant temperature bath controlled to within ~0.05°F(0.03~C). Once thermal equilibrium was WO 94126836 _ ~ ~ ~ ~ ~ ~ PCTIUS93104577 attained, as determined by constant vapor pressure readings, vapor and liquid samples were withdrawn from the vessel and analyzed by standard gas chromatographic techniques. This procedure was repeated at three nominal .
5r compositions of about 25. 50, and 75 weight percent HFC-125 in HFC-143a, and at three temperatures of _ -10°F(-Z3.3°C). 70°F(21.1°C), and 112.5°F(44.7°C). Table I summarizes the results of these experiments. In Table I, the compositions are in weight percent HFC-125 in HFC_143a.
TABLE I
VAPOR LIOUTD EOUILIBRIA DATA
Liquid Composition Yapor Composition Tomparaturo lei8ht Porconta8a(iloi8ht Porca~tasoVspor Pressure C ltlC-125) tilC-125) osia(kPa) -10.0(-23.3) 0.0 0.0 40.2(268) -10.0(-23.3) 22.4 22.1 40.1(261) -10.0(-23.3) 51.2 52.0 40.1(261) -10.0(-23.3)76.1 77.0 41.0(273) -I0.0(-23.3) 100.0 100.0 43.5(290) 70.0(21.1) 0.0 0.0 165.2(1101) 70.0<21.1) 22.5 22.8 165.2(1101) 70.0(21.1) 51.0 52.3 167.1(1114) 70.0(21.1) 76.0 77.7 171.6(1144) 700(21.1) 100.0 100.0 180.0(1200) 112.5(44.7) 0.0 0.0 297.9(1986) 112.5(44.7) 22.4 23.1 299.2(1995) 112.5(A4.7) 50.9 50.6 300.9(2006) 112.5(44.7) 7i.2 78.0 309.9(2066) 112.5(44.7) 100.0 100.0 326.0(2173) The data shown in Table I indicate that the vapor and liquid compositions are essentially identical within the experimental uncertainty o! ~1.0 weight percent unit ' associated with the chromatographic analysis. The vapor pressures of the blends ate essentially constant to within _+2s over the composition range from about 1 to about SO
weight percent HFC-125 and from about 99 to about 20 weight percent FTFC-143a, i.e. these blends are constant-boiling or azeottope-like.
~VO 9412683 ~ ~ ~ ~ ~ ~ 3 PCTIUS93104577 This example shows that certain HFC-125/HFC-143a r blends are nonflammable.
Flammability measurements were performed using the ASTM E-681 technique modified according to ASHRAE Standard 34. Briefly, this technique involves preparing fluorocarbon/air gas mixtures to a total pressure of one atmosphere(l~lkPa) in a 5-liter spherical glass vessel, stirring the mixture with a magnetically driven propeller to ensure a uniform composition, and then attempting to ignite the mixture using an electrically activated kitchen match head as the ignition source. A ternary flammability diagram was mapped by preparing mixtures of HFC-125.
HFC-143a, and air by the method of partial pressures and then determiniaQ whether or not a flaae would propagate as defined by ASTM E-681. The critical flammability composition, i.e. the composition of the HFC-125/HFC-143a blend which contains the maximum proportion of the flammable HFC-143a but does not exhibit flame limits in air, was determined fa a graphical manner siailar to that described is Haenai et a1, Industrial and Encineeriaa ~heaistrv ~. 695(1959). The critical flaamability composition was found to be 61.6 weight percent HFC-143a sad about 38.4 weight percent H1~C-135. in other words, blends of IBC-125 and HPC-143a containing 38.4 or more woiQht percent HFC-125 ate nonflammable in all proportions in air at ambient conditions.
~]CAMPLE 3 This example shows that a bland of 50 weight percent HPC-125 and 50 weight percent FZEC-143a undergoes essentially no fractionation and maintains a constant-vapor pressure during a vapor leak which illustrates one advantage of a constant-boiling or azeotrope-like composition.
The vessel described in Example 1 was charged with approximately 105 grams of a 50/50 weight percent mixture of HFC-125 and HFC-143a. Vapor was allowed to leak from this container until about 14 weight percent of the ociginal charge had dissipated, at which point the vapor pressure of the remaining liquid was measured and a vapor phase sample collected for analysis. The vapor leak was continued until 80s of the original charge had dissipated;
additional vapor samples were taken for analysis at different stages during the leak. The temperature of the ~esael was maintained at 70°F(21.1°C) during the leak.
Vapor pressure and composition data are reported in Table II. In Table II, the composition is in weight percent H8C-125 is HFC-143a.
TABLE II
1'RACTIONATION DATA
Parcntt Vapor Pnssura Yspor Composition pissivstion vsia<kPa) (iisishi Pvrea~t !~C-125) 0.0 1f7.3(1115) 50.0 1.4 167.0(1113) S0.
31.7 166.2(1108) 19.8 1.5 165.1(1103) 19.6 f1.3 161.7(1091) 41.1 79.9 163.3(1089) 1.1 R~sidu~ liquid 11.6 E~sidu~ vapor 4E.6 The data listed in Table II show that the composition of the aiaure varies by no sore than 1.2 weight percent and that the vapor pressure resains constant within 4psia (27 kPa) or about 2. SS o! the total pressure.
~'VO 9412683 PCTlUS93104577 ExAMPLE 4 This example shows that constant-boiling HFC-125/
., HFC-143a blends have certain advantages when compared to other refrigerants which are currently used in certain ~ refrigeration cycles.
The theoretical performance of a refrigerant at specific operating conditions can be estimated from the:
thermodynamic properties of the refrigerant using standard refrigeration cycle analysis techniques; see for example, R. C. Downing. FLUOROCARBONS REFRIGERANTS HANDBOOK.
Chapter 3, Prentice-Hall, 1988. The coefficient of perfotmance(COP) is a universally accepted measure, especially useful is cepresentiag the relative thermodynamic efficiency of a refrigerant is a specific heating or cooling cycle involving evaporation or coadensatioa o! the reftiqeraat. In refrigeration engineering, this term expresses the ratio of useful refrigeration to the energy applied by the compressor in compressing the vapor. The capacity of a refrigerant represents the voluaetric effectiveness of the refrigerant. To a coapressor engineer, this value expresses the capability of a compressor to pump quantities of heat for a given voluaetric floe rata of reftiqeraat. Ia other words, given a specific compressor, a refrigerant with a higher capacity will deliver more cooling of heating power.
We have performed this type of calculation for a medium to low teaperature refrigeration cycle where the condenser tenpetature is typically 100~1~(38'C) and the evapoeatoc teaperature is typically -40 to -10~!(-~0 to -23.3'C). We have further assuaed iseatropic coapression and a compressor inlet temperature of 65~P(18.3~C). Such calculations ware performed for a 60/40 by weight percent WO 94126836 ~, ~ ~ ~ ~ ~ '~ PCTlUS93104577 blend of HFC-125 and HFC-143a as well as for R-502. Table III lists the COP of a 60/40 blend of HFC-125 and HFC-143a relative to that of R-502 over a range of evaporator temperatures. In Table III. the * indicates that COP and capacity ace given relative to R-502.
TABLE III
THERMODYNAMIC PERFORMANCE
R-502 1251113a Evaporator Discharsa DischarEo T~. Tamp. Tune.
'F 'C COp* Canacitv* 'F 'C 'F 'C
-40(-10) 1.01 1.08 235(113) 213(101) -30(-3) 1.00 1.01 220(l0A) 200(93) -20(-29) 0.99 1.07 205(96) 189(87) -10(-23) 0.99 1.06 192(89) 177(81) The data listed in Table III show that the HFC-125/HFC-143a bland provides essentially the sane COP(within ~ii) as that attainable with E-502, provides about a 7: increase in refriQetation capacity, and also products lower discharge teapecatures frog the coapressor.
which contributes to coapressor reliability. It has been recoaaended that coapressor discharge teaperatuces be liaited to about 225~T(107.2~C). This teaperature is exceeded in the current exaaple by 8-502 at evaporator teaperatures lower than -35~F(-37.2~C): the HEC-125/
H!C-143a blend can operate down to as evaporator teaperature of -50~F(-45.6~C) before exceeding the 225~r(107.2~C) discharge teaperature liait. Even cower evaporator teaperatures could be accoaplished by enriching the H8C-125 component up to 80i of the total aixture.
without significant iapact on the perforaance.
Having described the invention in detail and by reference to preferred embodiments thereof, it will be ~O 94126836 ~ ~ 3 PCT/US93104577 apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims.
S
Claims (8)
1. Azeotrope-like compositions comprising 53.7 weight percent ~ 4 weight percent pentafluoroethane and 46.3 weight percent 1,1,1-trifluoroethane ~ 4 weight percent which have a vapor pressure of 167 psia ~ 6 psia at 70°F.
2. Azeotrope-like compositions according to claim 1 comprising 51 weight percent pentafluoroethane and 49 weight percent 1,1,1-trifluoroethane.
3. Azeotrope-like compositions according, to claim 1 comprising 50 weight percent pentafluoroethane and 50 weight percent 1,1,1-trifluoroethane.
4. A method for producing refrigeration which comprises condensing a refrigerant comprising an azeotrope-like composition as described in any of claims 1 to 3 and evaporating said refrigerant in the vicinity of a body to be cooled.
5. A method for producing heat which comprises condensing a refrigerant comprising an azeotropic composition as described in claims 1 through 3 in the vicinity of a body to be heated and thereafter evaporating said refrigerant.
6. A method for producing refrigeration which comprises condensing a refrigerant comprising an azeotrope-like composition as described in claim 3 and evaporating said refrigerant in the vicinity of a body to be cooled.
7. A method for producing refrigeration in a refrigeration application for which R-502 has been used or is applicable comprising condensing a refrigerant comprising an azeotropic composition as described in claims 1 through a and evaporating, said refrigerant in the vicinity of a body to be cooled
8. A method for producing refrigeration in a refrigeration application for which R-502 has been used or is applicable comprising condensing a refrigerant comprising an azeotropic composition as described in claim 3 and evaporating said refrigerant in the vicinity of a body to be cooled.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/741,202 US5211867A (en) | 1989-06-28 | 1991-07-30 | Azeotrope-like compositions of pentafluoroethane and 1,1,1-trifluoroethane |
| CA002161813A CA2161813C (en) | 1991-07-30 | 1993-05-13 | Azeotrope-like compositions of pentafluoroethane and 1,1,1,-trifluoroethane |
| EP93911313A EP0705317A1 (en) | 1993-05-13 | 1993-05-13 | Azeotrope-like compositions of pentafluoroethane and 1,1,1-trifluoroethane |
| PCT/US1993/004577 WO1994026836A1 (en) | 1991-07-30 | 1993-05-13 | Azeotrope-like compositions of pentafluoroethane and 1,1,1-trifluoroethane |
| JP6525363A JPH08511043A (en) | 1993-05-13 | 1993-05-13 | Azeotrope-like composition of pentafluoroethane and 1,1,1-trifluoroethane |
| AU40423/93A AU690066B2 (en) | 1993-05-13 | 1993-05-13 | Azeotrope-like compositions of pentafluoroethane and 1,1,1-trifluoroethane |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/741,202 US5211867A (en) | 1989-06-28 | 1991-07-30 | Azeotrope-like compositions of pentafluoroethane and 1,1,1-trifluoroethane |
| CA002161813A CA2161813C (en) | 1991-07-30 | 1993-05-13 | Azeotrope-like compositions of pentafluoroethane and 1,1,1,-trifluoroethane |
| PCT/US1993/004577 WO1994026836A1 (en) | 1991-07-30 | 1993-05-13 | Azeotrope-like compositions of pentafluoroethane and 1,1,1-trifluoroethane |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2161813A1 CA2161813A1 (en) | 1994-11-24 |
| CA2161813C true CA2161813C (en) | 2004-09-28 |
Family
ID=4156880
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002161813A Expired - Lifetime CA2161813C (en) | 1989-06-28 | 1993-05-13 | Azeotrope-like compositions of pentafluoroethane and 1,1,1,-trifluoroethane |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0705317A1 (en) |
| JP (1) | JPH08511043A (en) |
| AU (1) | AU690066B2 (en) |
| CA (1) | CA2161813C (en) |
| WO (1) | WO1994026836A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7608574B2 (en) * | 2006-08-17 | 2009-10-27 | Honeywell International Inc. | Azeotropic or azeotropic-like compositions of 1,1,1-trifuoroethane and 1-chloro-2,2,2-trifluoroethane |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH075881B2 (en) | 1987-10-02 | 1995-01-25 | 旭硝子株式会社 | Working medium mixture |
| US4943388A (en) * | 1989-06-28 | 1990-07-24 | Allied-Signal Inc. | Azeotrope-like compositions of pentafluoroethane; 1,1,1-trifluoroethane; and chlorodifluoromethane |
| US5211867A (en) * | 1989-06-28 | 1993-05-18 | Allied-Signal Inc. | Azeotrope-like compositions of pentafluoroethane and 1,1,1-trifluoroethane |
| JPH03170583A (en) * | 1989-11-30 | 1991-07-24 | Matsushita Electric Ind Co Ltd | Working fluid |
| JPH06281272A (en) * | 1991-07-08 | 1994-10-07 | Daikin Ind Ltd | Maximum azeotropic mixture and azeotropiclike mixture |
-
1993
- 1993-05-13 CA CA002161813A patent/CA2161813C/en not_active Expired - Lifetime
- 1993-05-13 WO PCT/US1993/004577 patent/WO1994026836A1/en not_active Application Discontinuation
- 1993-05-13 JP JP6525363A patent/JPH08511043A/en active Pending
- 1993-05-13 AU AU40423/93A patent/AU690066B2/en not_active Expired
- 1993-05-13 EP EP93911313A patent/EP0705317A1/en not_active Ceased
Also Published As
| Publication number | Publication date |
|---|---|
| CA2161813A1 (en) | 1994-11-24 |
| AU690066B2 (en) | 1998-04-23 |
| EP0705317A1 (en) | 1996-04-10 |
| AU4042393A (en) | 1994-12-12 |
| WO1994026836A1 (en) | 1994-11-24 |
| JPH08511043A (en) | 1996-11-19 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request |