EP3019574A1

EP3019574A1 - 2,3,3,3-tetrafluoropropene compositions having improved miscibility

Info

Publication number: EP3019574A1
Application number: EP14736904.5A
Authority: EP
Inventors: Sophie GUERIN; Wissam Rached
Original assignee: Arkema France SA
Current assignee: Arkema France SA
Priority date: 2013-07-11
Filing date: 2014-06-13
Publication date: 2016-05-18
Also published as: CN105378021A; AU2014289096A1; US20160376484A1; US10023780B2; US20180282603A1; JP6581977B2; WO2015004353A1; FR3008419B1; US10377935B2; AU2014289096B2; JP2016529351A; CN105378021B; FR3008419A1

Abstract

The invention relates to the use of an alcoholic compound to improve the miscibility of ammonia with 2,3,3,3-tetrafluoropropene, as well as to compositions of ammonia, 2,3,3,3-tetrafluoropropene and an alcoholic compound, and the use thereof, in particular in heat-transfer applications.

Description

COMPOSITIONS BASED ON 2,3,3,3-TETRAFLUOROPROPENE

HAVING IMPROVED MISCIBILITY

FIELD OF THE INVENTION

The present invention relates to the use of alcoholic compounds to improve the miscibility of compositions based on 2,3,3,3-tetrafluoropropene and the use of these compositions in particular for heat transfer. TECHNICAL BACKGROUND

Fluorocarbon-based fluids are widely used in vapor compression heat transfer systems, including air conditioning, heat pump, refrigeration or freezing devices. These devices have in common to rely on a thermodynamic cycle comprising the vaporization of the fluid at low pressure (in which the fluid absorbs heat); compressing the vaporized fluid to a high pressure; condensing the vaporized fluid into a high pressure liquid (in which the fluid emits heat); and the expansion of the fluid to complete the cycle.

The choice of a heat transfer fluid (which may be a pure compound or a mixture of compounds) is dictated on the one hand by the thermodynamic properties of the fluid, and on the other hand by additional constraints. Thus, a particularly important criterion is that of the impact of the fluid considered on the environment. In particular, chlorinated compounds (chlorofluorocarbons and hydrochlorofluorocarbons) have the disadvantage of damaging the ozone layer. Thus, non-chlorinated compounds such as hydrofluorocarbons, fluoroethers and fluoroolefins are now generally preferred.

Another environmental constraint is that of global warming potential (GWP). It is therefore essential to develop heat transfer compositions with as low a GWP as possible and good energy performance.

WO 2006/094303 describes a large number of heat transfer compositions comprising fluorolefins, and in particular 2,3,3,3-tetrafluoropropene (HFO-1234yf), and additional compounds. WO 2007/126414 describes a large number of mixtures of heat transfer compounds, including mixtures comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and ammonia.

WO 2008/009928 and WO 2008/009922 disclose heat transfer compositions based on pentafluoropropene, tetrafluoropropene and at least one additional compound, which may be ammonia.

Document US 2006/0243945 describes a large number of mixtures of heat transfer compounds, and in particular quaternary compositions based on HFO-1234yf, ammonia, difluoromethane (HFC-32) and trifluoroiodomethane.

EP 2487216 describes binary compositions of HFO-1234yf and of azeotropic or quasi-azeotropic ammonia.

The mixture of HFO-1234yf and ammonia represents an advantageous composition, especially for heat transfer applications - in particular because the HFO-1234yf is a very interesting compound given its low GWP and its good energy performance. . However, the miscibility of the two compounds is limited. Thus, the azeotropic mixture composed of 78% HFO-1234yf and 22% ammonia is demixed at a temperature of less than or equal to -21 ° C.

It is therefore desirable to develop compositions based on HFO-1234yf and ammonia with improved miscibility. SUMMARY OF THE INVENTION

The invention firstly relates to a composition comprising 2,3,3,3-tetrafluoropropene, ammonia and an alcoholic compound having a melting point of less than or equal to 0 ° C.

According to one embodiment, the alcoholic compound has a melting point less than or equal to -50 ° C, preferably less than or equal to -80 ° C; and / or the alcoholic compound has a viscosity at 20 ° C. of less than or equal to 32.5 mm ² / s, preferably less than or equal to 15 mm ² / s and more particularly preferably less than or equal to 5 mm ² / s.

According to one embodiment, the alcoholic compound is a primary alcohol of formula R 1 -CH 2 -OH, or a secondary alcohol of formula R ₂ R ₃ -CH-OH, or a tertiary alcohol of formula R ₄ R ₅ R 6-C-OH, or an enol of formula R ₇ R _{8 C} = CR ₉ OH, or a phenol of formula R 10 -OH, the groups R 1, R 2, R 3, R 4, R 5, R 6, R 7, R ₉ and R ₉ each independently represent a linear or branched alkyl group comprising from 1 to 20 carbon atoms, preferably from 1 to 10 carbon atoms and more particularly preferred from 1 to 7 carbon atoms, optionally substituted in whole or in part by F, Br, Cl or OH; and R ₀ represents a benzene ring optionally substituted in whole or in part with F, Br, Cl, OH or with alkyl groups as defined above.

According to one embodiment, the alcoholic compound is chosen from propan-1-ol, propan-2-ol, 2-perfluorohexylethanol and 1,1,1,3,3,3-hexafluoropropan-2-ol and their mixtures.

According to one embodiment, the composition comprises:

from 1 to 60% of ammonia and from 40 to 99% of 2,3,3,3-tetrafluoropropene;

preferably from 5 to 45% of ammonia and from 55 to 95% of 2,3,3,3-tetrafluoropropene;

preferably from 15 to 30% of ammonia and from 70 to 85% of 2,3,3,3-tetrafluoropropene;

preferably 18 to 26% of ammonia and 74 to 82% of 2,3,3,3-tetrafluoropropene;

preferably from 21 to 23% of ammonia and from 77 to 79% of

2,3,3,3-tetrafluoropropene;

the proportions being given in relation to the sum of ammonia and 2,3,3,3-tetrafluoropropene.

According to one embodiment, the alcoholic compound is present in a proportion of 0.1 to 20%, preferably 0.5 to 10%, preferably 1 to 5%, relative to the sum of the alcoholic compound, ammonia and 2,3,3,3-tetrafluoropropene.

According to one embodiment, the composition consists essentially of a mixture of ammonia, 2,3,3,3-tetrafluoropropene and the alcoholic compound.

According to one embodiment, the composition has a demixing temperature of less than or equal to -23 ° C., preferably less than or equal to -25 ° C., preferably less than or equal to -27 ° C., preferably less than or equal to -29 ° C, preferably less than or equal to -31 ° C, preferably less than or equal to -33 ° C, preferably less than or equal to -35 ° C.

According to one embodiment, the composition further comprises one or more additives chosen from lubricants and preferably polyalkylene glycols, stabilizers, tracers, fluorescers, odorants, solubilizers and mixtures thereof.

The invention also relates to the use of the composition as described above as a heat transfer composition.

The invention also relates to the use of an alcoholic compound to improve the miscibility of ammonia with 2,3,3,3-tetrafluoropropene.

According to one embodiment, the alcoholic compound has a melting point less than or equal to 0 ° C, preferably less than or equal to -50 ° C, more preferably less than or equal to -80 ° C; and / or the alcoholic compound has a viscosity at 20 ° C. of less than or equal to 32.5 mm ² / s, preferably less than or equal to 15 mm ² / s and more particularly preferably less than or equal to 5 mm ² / s.

According to one embodiment, the alcoholic compound is a primary alcohol of formula R 1 -CH 2 -OH, or a secondary alcohol of formula R ₂ R ₃ -CH-OH, or a tertiary alcohol of formula R ₄ R ₅ R 6-C-OH, or an enol of formula or a phenol of formula R10-OH, the groups R 1, R 2, R 3, R 4, R 5, R 6, R 7, R ₉ and R ₉ each independently representing a linear or branched alkyl group comprising from 1 to 20 carbon atoms, preferably from 1 to 10 carbon atoms and more preferably 1 to 5 carbon atoms, optionally substituted in whole or in part by F, Br, Cl or OH; and R10 represents a benzene ring optionally substituted in whole or in part by F, Br, Cl, OH or by alkyl groups as defined above.

According to one embodiment, ammonia and 2,3,3,3-tetrafluoroproene are combined in a mixture comprising:

from 1 to 60% of ammonia and from 40 to 99% of 2,3,3,3-tetrafluoropropene;

preferably from 15 to 30% of ammonia and from 70 to 85% of 2,3,3,3-tetrafluoropropene; preferably 18 to 26% of ammonia and 74 to 82% of 2,3,3,3-tetrafluoropropene;

preferably from 21 to 23% of ammonia and from 77 to 79% of 2,3,3,3-tetrafluoropropene.

According to one embodiment, the alcoholic compound is added to a mixture of ammonia and 2,3,3,3-tetrafluoropropene in a proportion of 0.1 to 20%, preferably 0.5 to 10%, of preferably 1 to 5%, based on the sum of the three compounds.

In one embodiment, ammonia and 2,3,3,3-tetrafluoropropene are not combined with any heat transfer compound.

The invention also relates to a heat transfer installation comprising a vapor compression circuit containing a composition as described above as a heat transfer composition.

According to one embodiment, the plant is chosen from mobile or stationary heat pump heating, air conditioning, refrigeration, freezing and Rankine cycles, and in particular from automotive air-conditioning installations.

According to one embodiment, the installation is an automotive air conditioning installation.

The invention also relates to a method for heating or cooling a fluid or a body by means of a vapor compression circuit containing a heat transfer fluid, said method comprising successively at least partial evaporation of the heat transfer fluid, compression of the heat transfer fluid, at least partial condensation of the heat transfer fluid and expansion of the heat transfer fluid, wherein the heat transfer fluid is provided by a composition such as as described above.

The invention also relates to a method for reducing the environmental impact of a heat transfer installation comprising a vapor compression circuit containing an initial heat transfer fluid, said method comprising a step of replacing the heat transfer fluid. initial heat in the vapor compression circuit by a final heat transfer fluid, the final heat transfer fluid having a GWP lower than the initial heat transfer fluid, in wherein the final heat transfer fluid is provided by a composition as described above.

The invention also relates to the use of the composition described above as a solvent.

The invention also relates to the use of the composition described above as an expanding agent.

The invention also relates to the use of the composition described above as a propellant, preferably for an aerosol.

The invention also relates to the use of the composition described above as a cleaning agent.

The present invention makes it possible to meet the needs felt in the state of the art. It provides more particularly compositions based on HFO-1234yf and ammonia with improved miscibility.

This is accomplished through the use of alcoholic compounds as compatibilizing additives. It has surprisingly been found that these additives make it possible to improve the miscibility of the HFO-1234 / ammonia mixture, whereas other surfactant compounds do not improve it, even degrade it, or even are incompatible with the mixture. DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The invention is now described in more detail and without limitation in the description which follows.

Unless otherwise stated, in the whole of the application the proportions of compounds indicated are given in percentages by mass.

According to the present application, the global warming potential (GWP) is defined with respect to the carbon dioxide and with respect to a duration of 100 years, according to the method indicated in "The scientific assessment of ozone depletion, 2002, a report of the World Meteorological Association's Global Ozone Research and Monitoring Project.

By "heat transfer compound" or "heat transfer fluid" (or refrigerant), is meant a compound, respectively a fluid, capable of absorbing heat by evaporating at low temperature and low pressure and to reject heat by condensing at high temperature and high pressure, in a vapor compression circuit. In general, a heat transfer fluid may comprise one, two, three or more than three heat transfer compounds. By "heat transfer composition" is meant a composition comprising a heat transfer fluid and optionally one or more additives which are not heat transfer compounds for the intended application.

The invention is based on the use of two heat transfer compounds, namely HFO-1234yf and ammonia, and a compatibilizing additive, namely an alcoholic compound, to form heat transfer compositions, optionally with other additives including lubricants.

The heat transfer composition can be introduced as such into a vapor compression circuit. Alternatively, the heat transfer fluid (comprising HFO-1234yf and ammonia) can be introduced separately into the circuit with the compatibilizing additive, and on the other hand with other additives (in particular lubricant), at the same point or not. The heat transfer fluid (comprising HFO-1234yf and ammonia) and the compatibilizing additive can be introduced separately, optionally with other additives and in particular lubricant. The individual heat transfer compounds (HFO-1234yf and ammonia) can also be introduced separately.

The heat transfer compounds mainly used in the context of the present invention are HFO-1234yf and ammonia.

However, the heat transfer compositions according to the invention may optionally comprise one or more additional heat transfer compounds, besides HFO-1234yf and ammonia. These additional heat transfer compounds may be chosen especially from hydrocarbons, hydrofluorocarbons, ethers, hydrofluoroethers and fluoroolefins.

According to particular embodiments, the heat transfer fluids according to the invention may be ternary (consisting of three heat transfer compounds) or quaternary (consisting of four heat transfer compounds) compositions, in association with the lubricant. to form the heat transfer compositions according to the invention.

However, binary heat transfer fluids are preferred. By binary fluid is meant either a fluid consisting of a mixture of HFO-1234yf and ammonia; a fluid consisting essentially of a mixture of HFO-1234yf and ammonia, but which may contain impurities of less than 1%, preferably less than 0.5%, of preferably less than 0.1%, preferably less than 0.05% and preferably less than 0.01%.

According to particular embodiments, the proportion of HFO-1234yf in the heat transfer fluid may be: 0.1 to 5%; or 5 to 10%; or 10 to 15%; or 15 to 20%; or from 20 to 25%; or 25 to 30%; or from 30 to 35%; or 35 to 40%; or 40 to 45%; or 45 to 50%; or 50 to 55%; or 55 to 60%; or from 60 to 65%; or from 65 to 70%; or 70 to 75%; or from 75 to 80%; or from 80 to 85%; or from 85 to 90%; or from 90 to 95%; or 95 to 99.9%.

According to particular embodiments, the proportion of ammonia in the heat transfer fluid may be: 0.1 to 5%; or 5 to 10%; or 10 to 15%; or 15 to 20%; or from 20 to 25%; or 25 to 30%; or from 30 to 35%; or 35 to 40%; or 40 to 45%; or 45 to 50%; or 50 to 55%; or 55 to 60%; or from 60 to 65%; or from 65 to 70%; or 70 to 75%; or from 75 to 80%; or from 80 to 85%; or from 85 to 90%; or from 90 to 95%; or 95 to 99.9%.

The values given in the preceding three paragraphs apply to the heat transfer fluid without additives, and not to the heat transfer composition which comprises the heat transfer fluid, the compatibilizing additive and possibly other additives.

It may be preferable not to have a too high proportion of NH ₃ in the mixture, as part of a use as a heat transfer fluid, in order to avoid a too high temperature rise at the outlet of the compressor .

Of the above heat transfer fluids, some have the advantage of being azeotropic or near-azeotropic. For example, it has been found that the azeotrope for the binary mixture HFO-1234yf / NH ₃ is obtained for a proportion of NH ₃ of about 23% (± 2%) at a temperature of 5 ° C (± 1%). ° C) and at a pressure of 7.3 bar (± 1 bar).

The term "quasi-azeotropic" refers to those compositions for which, at a constant temperature, the liquid saturation pressure and the vapor saturation pressure are almost identical (the maximum pressure difference being 10%, or even advantageously 5%, relative to at the liquid saturation pressure).

For "azeotropic" compositions, at a constant temperature, the maximum pressure difference is close to 0%.

These heat transfer fluids have the advantage of ease of implementation. In the absence of significant temperature there is no significant change in the circulating composition, and no significant change in composition in case of leakage.

In addition, certain compositions according to the invention have improved performances compared with R404A (mixture of 52% of 1,1,1-trifluoroethane, 44% of pentafluoroethane and 4% of 1,1,1,2-tetrafluoroethane). ) and / or R410A (mixture of 50% of difluoromethane and 50% of pentafluoroethane), in particular for the processes of cooling at moderate temperature, that is to say those in which the temperature of the cooled fluid or body is from -15 ° C to 15 ° C, preferably from -10 ° C to 10 ° C, more preferably from -5 ° C to 5 ° C (most preferably about 0 ° C). In this regard, the compositions for which the proportion of NH ₃ is greater than or equal to 15% are particularly preferred, especially the compositions having a proportion of NH ₃ of 15 to 30%, preferably 18 to 26%.

In addition, certain compositions according to the invention have improved performances compared to R410A, in particular for moderate temperature heating processes, that is to say those in which the temperature of the fluid or of the heated body is 30.degree. ° C to 80 ° C, and preferably 35 ° C to 55 ° C, more preferably 40 ° C to 50 ° C (most preferably about 45 ° C). In this respect, the compositions for which the proportion of NH ₃ is greater than or equal to 15% are particularly preferred, especially the compositions having a proportion of NH ₃ of 20 to 30%.

The compatibilizing additive used in the context of the present invention is an alcoholic compound, that is to say an organic compound having at least one -OH alcohol function. The compound may comprise a single alcohol function or several (polyol, or glycol).

The alcoholic compound may in particular be a primary alcohol of formula R 1 -CH 2 -OH, or a secondary alcohol of formula R ₂ R ₃ -CH-OH, or a tertiary alcohol of formula R ₄ R ₅ R 6 -C-OH, or an enol Formula or a phenol of formula R10-OH.

Preferably it is a primary alcohol of formula R 1 -CH 2 -OH, or of a secondary alcohol of formula R ₂ R ₃ -CH-OH, or of a tertiary alcohol of formula R ₄ R ₅ R ₆ - C-OH.

The groups R 1, R ₂ , R ₃ , R ₄ , R ₅ , R 6, R 7, R ₈ and R ₉ above each independently represent a linear or branched alkyl group comprising from 1 to 20 carbon atoms, or from 1 to 15 carbon atoms. carbon atoms, or from 1 to 12 carbon atoms, or from 1 to 10 carbon atoms, or from 1 to 9 carbon atoms, or from 1 to 8 carbon atoms, or from 1 to 7 carbon atoms, or from 1 to 6 carbon atoms, or from 1 to 5 carbon atoms, or from 1 to 4 carbon atoms, or from 1 to 3 carbon atoms.

Each of these groups may be substituted in whole or in part by F, Br, Cl or OH, preferably by F, Br or Cl.

The group Rio represents a benzene ring optionally substituted in whole or in part by F, Br, Cl, OH or by one or more alkyl groups as defined above.

According to a particular embodiment, the alcoholic compound is a primary alcohol of formula R 1 -CH 2 -OH, or a secondary alcohol of formula R ₂ R ₃ -CH-OH, or a tertiary alcohol of formula R ₄ R ₅ R 6-C-OH, each R 1, R ₂ , R ₃ , R 4, R 5, R 6 group representing a linear alkyl group having 1 to 8 carbon atoms, optionally substituted in whole or in part by fluorine atoms.

For reasons of compatibility with some of the applications described (especially in the field of heat transfer), the main compounds retained are those having a melting temperature of less than or equal to 0 ° C .; or less than or equal to -5 ° C; or less than or equal to -10 ° C; or less than or equal to -15 ° C; or less than or equal to -20 ° C; or less than or equal to -25 ° C; or less than or equal to -30 ° C; or less than or equal to -35 ° C; or less than or equal to -40 ° C; or less than or equal to -45 ° C; or less than or equal to -50 ° C; or less than or equal to -55 ° C; or less than or equal to -60 ° C; or less than or equal to -65 ° C; or less than or equal to -70 ° C; or less than or equal to -75 ° C; or less than or equal to -80 ° C; or less than or equal to -85 ° C; or less than or equal to -90 ° C.

The melting point is determined according to ISO 1392: 1977.

According to one embodiment, the compatibilizing additive (alcoholic compound) is not a lubricant or a lubricating oil. In particular, it advantageously has a viscosity less than or equal to 32.5 mm ² / s, or 30 mm ² / s, or 27.5 mm ² / s, or 25 mm ² / s, or 22, 5 mm ² / s, or 20 mm ² / s, or 17.5 mm ² / s, or 15 mm ² / s, or 12.5 mm ² / s, or 10 mm ² / s, or 7.5 mm ² / s, or 5 mm ² / s, or 2.5 mm ² / s.

The viscosity (kinematic) is determined at 20 ° C according to the standard

ISO 3104: 1976.

By way of example, propan-1 -ol, propan-2-ol, 2-perfluorohexylethanol, 1,1,1,3,3,3-hexafluoropropan-2-ol or a combination of these. Propan-1-ol and propan-2-ol are particularly preferred, and especially propan-1-ol.

The proportion of compatibilizing additive, relative to the sum of HFO-1234yf, ammonia, and the compatibilizing additive itself, may be from 0.1 to 0.5%; or from 0.5 to 1.0%; or from 1.0 to 1.5%; or 1.5 to 2.0%; or 2.0 to 2.5%; or 2.5 to 3.0%; or from 3.0 to 3.5%; or 3.5 to 4.0%; or 4.0 to 4.5%; or 4.5 to 5.0%; or from 5.0 to 5.5%; or 5.5 to 6.0%; or 6.0 to 6.5%; or 6.5 to 7.0% or 7.0 to 7.5%; or 7.5 to 8.0%; or from 8.0 to 8.5%; or from 8.5 to 9.0%; or 9.0 to 9.5%; or 9.5 to 10.0%; from 10.0 to 10.5%; or from 10.5 to 11.0%; or from 1, 0 to 1, 1.5%; or from 1, 5 to 12.0%; or from 12.0 to 12.5%; or from 12.5 to 13.0%; or from 13.0 to 13.5%; or from 13.5 to 14.0%; or from 14.0 to 14.5%; or from 14.5 to 15.0%; or from 15.0 to 15.5%; or from 15.5 to 16.0%; or from 16.0 to 16.5%; or from 16.5 to 17.0%: or from 17.0 to 17.5%; or from 17.5 to 18.0%; or from 18.0 to 18.5%; or from 18.5 to 19.0%; or from 19.0 to 19.5%; or from 19.5 to 20.0%.

The compatibilizing additive makes it possible to improve the miscibility of the HFO-1234yf / ammonia mixture, that is to say to reduce the demixing temperature of the mixture, the demixing temperature being defined as being the temperature from which the formation an emulsion is observed (starting from a homogeneous mixture without emulsion of HFO-1234yf / ammonia and gradually decreasing the temperature).

The compatibilizing additive may be added to either of the HFO-1234yf and ammonia compounds prior to mixing, or added to the mixture of the two compounds.

The other additives that may be used in the context of the invention may especially be chosen from lubricants, stabilizers, tracer agents, fluorescent agents, odorants and solubilizing agents.

According to one embodiment, none of these other possible additives is an alcoholic compound as defined above.

Lubricants that may be used include oils of mineral origin, silicone oils, paraffins of natural origin, naphthenes, synthetic paraffins, alkylbenzenes, poly-alpha olefins, polyalkylenes glycols, polyols and the like. esters and / or polyvinyl ethers.

Polyalkylene glycols are preferred lubricants (or lubricating oils). For the purposes of the invention, the polyalkylene glycol may comprise polyalkylene glycols of different formulas in a mixture.

In general, the polyalkylene glycol suitable for use in the context of the invention comprises from 5 to 50 repeating oxyalkylene units, each containing from 1 to 5 carbon atoms.

The polyalkylene glycol may be linear or branched. It may be a homopolymer or a copolymer of 2, 3 or more groups selected from oxyethylene, oxypropylene, oxybutylene, oxypentylene and combinations thereof.

Preferred polyalkylene glycols comprise at least 50% oxypropylene groups.

Suitable polyalkylene glycols are disclosed in US 4,971,712. Other suitable polyalkylene glycols are the polyalkylene glycols having hydroxyl groups at each end, as described in US Pat. No. 4,755,316. Other suitable polyalkylene glycols are the polyalkylene glycols having a capped hydroxyl end. The hydroxyl group may be capped with an alkyl group containing from 1 to 10 carbon atoms (and optionally containing one or more heteroatoms such as nitrogen), or a fluoroalkyl group containing heteroatoms such as nitrogen, or a fluoroalkyl group as described in US 4,975,212, or other similar groups.

When the two hydroxyl ends of the polyalkylene glycol are capped, one can use the same end group or a combination of two distinct groups.

The terminal hydroxyl groups may also be capped to form an ester with a carboxylic acid, as described in US 5,008,028. The carboxylic acid can also be fluorinated.

When both ends of the polyalkylene glycol are capped, one or the other may be an ester, or one end may be capped with an ester and the other end be free or capped with one of the aforementioned alkyl, heteroalkyl or fluoroalkyl groups.

Polyalkylene glycols suitable for use as lubricating oils and commercially available are, for example, General Motors Goodwrench Oils, Daimler-Chrysler MOPAR-56, Shrieve Chemical Products Zerol, Total's Planetelf PAG and Daphne Hermetic PAG. Itemitsu. Other suitable polyalkylene glycols are manufactured by Dow Chemical and Denso. Mention may also be made of oils manufactured by Fuchs and in particular RENISO PG 68 / NH3 oil.

The viscosity of the polyalkylene glycol may for example be from 1 to 1000 centistokes at 40 ° C, preferably from 10 to 200 centistokes at 40 ° C and more preferably from 30 to 80 centistokes at 40 ° C.

The viscosity is determined according to ISO viscosity grades, according to ASTM D2422.

The oil marketed by Denso under the name ND8, having a viscosity of 46 centistokes, is particularly suitable.

The proportion of lubricating oil to be used in combination with the heat transfer fluid depends mainly on the type of installation concerned. Indeed, the total quantity of lubricating oil in the installation depends mainly on the nature of the compressor, while the total amount of heat transfer fluid in the installation depends mainly on the exchangers and the piping.

In general, the proportion of lubricating oil in the heat transfer composition, or in other words in relation to the sum of the lubricating oil and the heat transfer fluid, is from 1 to 99%, preferably from 5 to 50%, for example 10 to 40% or 15 to 35%.

According to a particular embodiment, the lubricating oil used consists of the polyalkylene glycol described above, with the exception of any other lubricating compound.

According to an alternative embodiment, another lubricating oil is used in combination with the polyalkylene glycol. It may especially be chosen from mineral oils, silicone oils, paraffins of natural origin, naphthenes, synthetic paraffins, alkylbenzenes, poly-alpha olefins, polyol esters and / or polyvinyl ethers. . Polyol esters and polyvinyl ethers are preferred.

The stabilizer (s), when present, preferably represent at most 5% by weight in the heat transfer composition. Among the stabilizers, there may be mentioned in particular nitromethane, ascorbic acid, terephthalic acid, azoles such as tolutriazole or benzotriazole, phenol compounds such as tocopherol, hydroquinone, t-butyl hydroquinone, 2,6-di-tert-butyl-4-methylphenol, epoxides (optionally fluorinated or perfluorinated alkyl or alkenyl or aromatic) such as n-butylglycidyl ether, hexanedioldiglycidyl ether, allylglycidyl ether, butylphenylglycidyl ether, phosphites, phosphonates, thiols and lactones. The stabilizer is different from the transfer compound (s) of heat comprising the heat transfer fluid and the compatibilizing additive.

As tracer agents (which can be detected) mention may be made of deuterated hydrofluorocarbons or not, deuterated hydrocarbons, perfluorocarbons, fluoroethers, brominated compounds, iodinated compounds, aldehydes, ketones, nitrogen and combinations thereof. The tracer agent is different from the one or more heat transfer compounds composing the heat transfer fluid and the compatibilizing additive.

As solubilizing agents, mention may be made of hydrocarbons, dimethyl ether, polyoxyalkylene ethers, amides, ketones, nitriles, chlorocarbons, esters, lactones, aryl ethers, fluoroethers and magnesium compounds. 1-trifluoroalkanes. The solubilizing agent is different from the one or more heat transfer compounds composing the heat transfer fluid and the compatibilizing additive.

As fluorescent agents, mention may be made of naphthalimides, perylenes, coumarins, anthracenes, phenanthracenes, xanthenes, thioxanthenes, naphthoxanhthenes, fluoresceins and derivatives and combinations thereof. The fluorescent agent is different from the one or more heat transfer compounds comprising the heat transfer fluid and the compatibilizing additive.

As odorants, mention may be made of alkyl acrylates, allyl acrylates, acrylic acids, acrylresters, alkyl ethers, alkyl esters, alkynes, aldehydes, thiols, thioethers, disulfides, allyl isothiocyanates and alkanoic acids. , amines, norbornenes, norbornene derivatives, cyclohexene, heterocyclic aromatic compounds, ascaridole, o-methoxy (methyl) phenol and combinations thereof. The odorant is different from the heat transfer compound (s) composing the heat transfer fluid and the compatibilizing additive.

The heat transfer method according to the invention is based on the use of an installation comprising a vapor compression circuit which contains a heat transfer composition as described above. The heat transfer process may be a method of heating or cooling a fluid or a body.

The vapor compression circuit includes at least one evaporator, a compressor, a condenser and an expander, and fluid transport lines between these elements. The evaporator and the condenser comprise a heat exchanger allowing a heat exchange between the heat transfer fluid and another fluid or body.

As a compressor, it is possible to use in particular a centrifugal compressor with one or more stages or a mini centrifugal compressor. Rotary, piston or screw compressors can also be used. The compressor may be driven by an electric motor or by a gas turbine (eg powered by vehicle exhaust, for mobile applications) or by gearing.

The facility may include a turbine to generate electricity (Rankine cycle).

The installation may also optionally include at least one coolant circuit used to transmit the heat (with or without change of state) between the heat transfer fluid circuit and the fluid or body to be heated or cooled.

The installation may also optionally include two or more vapor compression circuits containing identical or different heat transfer fluids. For example, the vapor compression circuits may be coupled together.

The vapor compression circuit operates in a conventional vapor compression cycle. The cycle comprises changing the state of the heat transfer fluid from a liquid phase (or two-phase liquid / vapor) to a vapor phase at a relatively low pressure, and then compressing the fluid in the vapor phase to a relatively high pressure. high, the change of state (condensation) of the heat transfer fluid from the vapor phase to the liquid phase at a relatively high pressure, and the reduction of the pressure to restart the cycle.

In the case of a cooling process, heat from the fluid or the body that is cooled (directly or indirectly, via a coolant) is absorbed by the heat transfer fluid, during the evaporation of the latter, and this at a relatively low temperature compared to the environment. Cooling processes include air conditioning processes (with mobile installations, for example in vehicles, or stationary), refrigeration and freezing or cryogenics.

In the case of a heating process, heat is transferred (directly or indirectly via a heat transfer fluid) from the heat transfer fluid, during the condensation thereof, to the fluid or to the body that is heating, and this at a relatively high temperature compared to the environment. The installation for implementing the heat transfer is called in this case "heat pump".

It is possible to use any type of heat exchanger for the implementation of heat transfer fluids according to the invention, and in particular co-current heat exchangers or, preferably, heat exchangers against -current. It is also possible to use microchannel exchangers.

The invention makes it possible in particular to implement cooling processes at moderate temperature, that is to say in which the temperature of the fluid or of the cooled body is from -15 ° C. to 15 ° C., preferably from -15 ° C. to 15.degree. 10 ° C to 10 ° C, more preferably -5 ° C to 5 ° C (most preferably about 0 ° C).

The invention also makes it possible to implement heating processes at a moderate temperature, that is to say in which the temperature of the fluid or of the heated body is from 30 ° C. to 70 ° C., and preferably 35 ° C. C at 55 ° C, more preferably at 40 ° C to 50 ° C (most preferably at about 45 ° C).

In the processes of "cooling or heating at moderate temperature" mentioned above, the inlet temperature of the heat transfer fluid to the evaporator is preferably from -20 ° C. to 10 ° C., especially from -15 ° C. ° C at 5 ° C, more preferably at -10 ° C to 0 ° C and for example about -5 ° C; and the temperature of the start of condensation of the heat transfer fluid at the condenser is preferably 25 ° C to 80 ° C, especially 30 ° C to 70 ° C, more preferably 35 ° C to 55 ° C C and for example about 50 ° C. These processes may be refrigeration, air conditioning or heating processes.

The invention also makes it possible to implement heating processes at high temperature, that is to say in which the temperature of the fluid or of the heated body is greater than 90 ° C., for example greater than or equal to 100 ° C. or greater than or equal to 1 10 ° C, and preferably less than or equal to 120 ° C.

The invention also makes it possible to implement refrigeration processes at low temperature, that is to say in which the temperature of the fluid or of the cooled body is from -40 ° C. to -10 ° C., and preferably from -40 ° C. to -10 ° C. 35 ° C to -25 ° C, more preferably -30 ° C to -20 ° C (most preferably about -25 ° C). In this respect, the compositions for which the proportion of NH ₃ is greater than or equal to 15% are particularly preferred, especially the compositions having an NH ₃ proportion of 18 to 24%.

In the "low temperature refrigeration" processes mentioned above, the inlet temperature of the heat transfer fluid to the evaporator is preferably from -45 ° C. to -15 ° C., especially from -40 ° C. at -20 ° C, more preferably -35 ° C to -25 ° C and for example about -30 ° C; and the temperature of the onset of condensation of the heat transfer fluid at the condenser is preferably 25 ° C to 80 ° C, especially 30 ° C to 60 ° C, more preferably 35 ° C to 55 ° C C and for example about 40 ° C.

According to a preferred embodiment, the heat transfer fluid is during the entire cycle at a temperature at which it is miscible. For example, the heat transfer fluid is during the entire cycle at a temperature between -20 ° C and 70 ° C.

It should be noted that the addition of the compatibilizing additive in the heat transfer fluid improves the miscibility of the heat transfer fluid, that is to say, decreases the demixing temperature (threshold temperature of appearance of the zone of non-miscibility, below which the compounds in the liquid phase form an emulsion), and thus makes it possible to increase the possibilities of use of the heat transfer fluid, for example with use at a higher evaporation temperature. low.

More generally, the invention makes it possible to proceed to the replacement of any heat transfer fluid in all heat transfer applications, and for example in automobile air conditioning. For example, the heat transfer fluids and heat transfer compositions according to the invention can serve to replace:

1,1,1,2-tetrafluoroethane (R134a);

1,1-Difluoroethane (R152a);

1,1,1,3,3-pentafluoropropane (R245fa);

mixtures of pentafluoroethane (R125), 1,1,1,2-tetrafluoroethane (R134a) and isobutane (R600a), namely R422;

chlorodifluoromethane (R22);

- the mixture of 51.2% chloropentafluoroethane (R1 15) and

48.8% chlorodifluoromethane (R22), namely R502;

- any hydrocarbon; the mixture of 20% of difluoromethane (R32), 40% of pentafluoroethane (R125) and 40% of 1, 1, 1, 2-tetrafluoroethane (R134a), namely R407A;

the mixture of 23% of difluoromethane (R32), 25% of pentafluoroethane (R125) and 52% of 1, 1, 1, 2-tetrafluoroethane

(R134a), namely R407C;

the mixture of 30% of difluoromethane (R32), 30% of pentafluoroethane (R125) and 40% of 1,1,1,2-tetrafluoroethane (R134a), namely R407F;

R1234yf (2,3,3,3-tetrafluoropropene);

R1234ze (1, 3,3,3-tetrafluoropropene).

The compositions according to the invention may also be useful as an expanding agent, propellant (eg for an aerosol), cleaning agent or solvent, in addition to their use as heat transfer fluids.

As the propellant, the compositions according to the invention can be used alone or in combination with known propellants. The propellant comprises, preferably consists of, a composition according to the invention. The active substance to be sprayed can be mixed with the propellant and inert compounds, solvents or other additives to form a sprayable composition. Preferably, the composition to be sprayed is an aerosol.

As the blowing agent, the compositions according to the invention may be included in an expansion composition, which preferably comprises one or more other compounds capable of reacting and forming a foam or cell structure under appropriate conditions, as is known to those skilled in the art.

In particular, the invention provides a process for preparing an expanded thermoplastic product comprising first the preparation of a polymeric expansion composition. Typically, the polymeric expansion composition is prepared by plasticizing a polymer resin and mixing the compounds of a blowing agent composition at an initial pressure. The plasticization of the polymer resin can be carried out under the effect of heat by heating the polymer resin to soften it sufficiently to mix a blowing agent composition. Generally, the plasticization temperature is close to the glass transition temperature or the melting temperature for the crystalline polymers. Other uses of the compositions according to the invention include uses as solvents, cleaning agents or the like. Examples include steam degreasing, precision cleaning, electronic circuit cleaning, dry cleaning, abrasive cleaning, solvents for deposition of lubricants and release agents, and other treatments. solvent or surface.

EXAMPLES

The following examples illustrate the invention without limiting it.

In all of these examples, the compatibility of various additives is tested with a mixture of 78% HFO-1234yf and 22% ammonia, as well as the effect of these additives on the miscibility of this mixture.

To do this, an autoclave controlled by a double jacket temperature and fed by a thermostatic bath is used. The autoclave is equipped with portholes. A light source and a camera are used to visualize the contents of the autoclave.

We begin by introducing the refrigerant (HFO-1234yf + ammonia) into the autoclave. Then a first quantity of additive is introduced and stirred. The temperature of the autoclave is varied until an emulsion is obtained which signals the immiscibility of the mixture. These steps are then repeated by adding additional quantities of additive. The concentrations are determined by weighing each component, with an uncertainty of 0.1 g for the refrigerant and 0.01 g for the additive. Example 1 - comparative

The effect of perfluorohex-1-enene is tested as an additive. After addition of 1% of additive, it is found that the additive is not compatible with the mixture HFO-1234yf / ammonia. Indeed, the addition of the additive causes the formation of an emulsion that does not disappear by increasing the temperature, as well as the appearance of deposits.

Example 2 - comparative

The effect of n-perfluorobutylethane is tested as an additive (melting point: -89 ° C.). There is no incompatibility of the additive with the mixture HFO-1234yf / ammonia. The effect of the additive on the miscibility of the HFO-1234yf / ammonia mixture is summarized in the following table: Proportion of additive Temperature of demixing

0% -21, 3 ° C

1, 1% -21, 5 ° C

2.1% -21.3 ° C

3.0% -20.5 ° C

4.0% -20.7 ° C

4.9% -20.5 ° C

It is therefore found that the additive does not improve the homogeneity of the HFO-1234yf / ammonia mixture and on the contrary tends to degrade it. Example 3 - comparative

The effect of perfluoro-n-octylethane is tested as an additive (melting point: -39 ° C.). There is no incompatibility of the additive with the mixture HFO-1234yf / ammonia. The effect of the additive on the miscibility of the HFO-1234yf / ammonia mixture is summarized in the following table:

It is therefore found that the additive does not improve the homogeneity of the HFO-1234yf / ammonia mixture and on the contrary tends to degrade it. Example 4 - comparative

The effect of perfluorodecylethylene is tested as an additive (melting temperature: + 21 ° C.). There is no incompatibility of the additive with the mixture HFO-1234yf / ammonia. The effect of the additive on the miscibility of the HFO-1234yf / ammonia mixture is summarized in the following table: Proportion of additive Temperature of demixing

0% -20.9 ° C

1, 1% -21, 0 ° C

2.0% -20.6 ° C

3.0% -19.6 ° C

4.0% -19.1 ° C

It is therefore found that the additive does not improve the homogeneity of the HFO-1234yf / ammonia mixture and on the contrary tends to degrade it. Example 5 - Invention

The effect of 2-perfluorohexylethanol is tested as an additive (melting point: -35 ° C.). There is no incompatibility of the additive with the mixture HFO-1234yf / ammonia. The effect of the additive on the miscibility of the HFO-1234yf / ammonia mixture is summarized in the following table:

It is therefore found that the additive improves the homogeneity of the HFO-1234yf / ammonia mixture. Example 6 - invention

The effect of 1, 1, 1, 3,3,3-hexafluoropropan-2-ol was tested as an additive (melting temperature: -4 ° C). There is no incompatibility of the additive with the mixture HFO-1234yf / ammonia. The effect of the additive on the miscibility of the HFO-1234yf / ammonia mixture is summarized in the following table: Proportion of additive Temperature of demixing

0% -21.5 ° C

1, 0% -23.2 ° C

1, 9% -24.7 ° C

2.9% -26.5 ° C

3.9% -28.4 ° C

4.9% -28.7 ° C

It is therefore found that the additive significantly improves the homogeneity of the HFO-1234yf / ammonia mixture. Example 7 - Invention

The effect of propan-2-ol is tested as an additive (melting point: -89 ° C.). There is no incompatibility of the additive with the mixture HFO-1234yf / ammonia. The effect of the additive on the miscibility of the HFO-1234yf / ammonia mixture is summarized in the following table:

It is therefore found that the additive greatly improves the homogeneity of the HFO-1234yf / ammonia mixture. Example 8 - invention

The effect of propan-1-ol is tested as an additive (melting point: -126 ° C.). There is no incompatibility of the additive with the mixture HFO-1234yf / ammonia. The effect of the additive on the miscibility of the HFO-1234yf / ammonia mixture is summarized in the following table: Proportion of additive Temperature of demixing

0% -22.2 ° C

0.42% -22.6 ° C

1, 01% -24.4 ° C

1.78% -27.4 ° C

2.24% -29.6 ° C

2.47% -30.3 ° C

3.17% -32.4 ° C

3.59% -33.5 ° C

3.97% -36.7 ° C

It is therefore found that the additive greatly improves the homogeneity of the HFO-1234yf / ammonia mixture.

Claims

A composition comprising 2,3,3,3-tetrafluoropropene, ammonia and an alcoholic compound having a melting point less than or equal to 0 ° C.

The composition of claim 1, wherein the alcoholic compound has a melting point of less than or equal to -50 ° C, preferably less than or equal to -80 ° C; and / or wherein the alcoholic compound has a viscosity at 20 ° C. of less than or equal to 32.5 mm ² / s, preferably less than or equal to 15 mm ² / s and more particularly preferably less than or equal to 5 mm ² / s.

A composition according to claim 1 or 2, wherein the alcoholic compound is a primary alcohol of formula R 1 -CH ₂ -OH, or a secondary alcohol of formula R ₂ R ₃ -CH-OH, or a tertiary alcohol of formula R ₄ R ₅ R ₆ - C-OH, or an enol of formula or a phenol of formula R 10 -OH, the groups R 1, R 2, R 3, R 4, R 5, R 6, R 7, R ₈ and R ₉ each independently representing a linear or branched alkyl group comprising from 1 to 20 carbon atoms, preferably from 1 to 10 carbon atoms and more preferably 1 to 7 carbon atoms, optionally substituted in whole or in part by F, Br, Cl or OH; and R10 represents a benzene ring optionally substituted in whole or in part by F, Br, Cl, OH or by alkyl groups as defined above.

Composition according to one of claims 1 to 3, wherein the alcoholic compound is chosen from propan-1-ol, propan-2-ol, 2-perfluorohexylethanol, 1, 1, 1, 3,3,3 hexafluoropropan-2-ol and mixtures thereof.

Composition according to one of Claims 1 to 4, comprising: from 1 to 60% of ammonia and from 40 to 99% of 2,3,3,3-tetrafluoropropene; preferably from 5 to 45% of ammonia and from 55 to 95% of 2,3,3,3-tetrafluoropropene;

preferably 18 to 26% of ammonia and 74 to 82% of 2,3,3,3-tetrafluoropropene;

preferably from 21 to 23% of ammonia and from 77 to 79% of 2,3,3,3-tetrafluoropropene;

Composition according to one of Claims 1 to 5, in which the alcoholic compound is present in a proportion of 0.1 to 20%, preferably 0.5 to 10%, preferably 1 to 5%, relative to the sum of the alcoholic compound, ammonia and 2,3,3,3-tetrafluoropropene.

Composition according to one of Claims 1 to 6, consisting essentially of a mixture of ammonia, 2,3,3,3-tetrafluoropropene and the alcoholic compound.

Composition according to one of claims 1 to 7, having a demixing temperature less than or equal to -23 ° C, preferably less than or equal to -25 ° C, preferably less than or equal to -27 ° C, preferably lower or equal to -29 ° C, preferably less than or equal to -31 ° C, preferably less than or equal to -33 ° C, preferably less than or equal to -35 ° C.

Composition according to one of claims 1 to 8, further comprising one or more additives chosen from lubricants and preferably polyalkylene glycols, stabilizers, tracer agents, fluorescent agents, odorants, solubilizing agents and their agents. mixtures.

10. Use of the composition according to one of claims 1 to 9 as a heat transfer composition. Use of an alcoholic compound to improve the miscibility of ammonia with 2,3,3,3-tetrafluoropropene.

Use according to claim 11, wherein the alcoholic compound has a melting temperature of 0 ° C or less, preferably less than or equal to -50 ° C, more preferably less than or equal to -80 ° C; and / or wherein the alcoholic compound has a viscosity at 20 ° C. of less than or equal to 32.5 mm ² / s, preferably less than or equal to 15 mm ² / s and more particularly preferably less than or equal to 5 mm ² / s.

Use according to claim 1 1 or 12, wherein the alcoholic compound is a primary alcohol of formula R 1 -CH ₂ -OH, or a secondary alcohol of formula R ₂ R ₃ -CH-OH, or a tertiary alcohol of formula R ₄ R ₅ R 6 -C-OH, or an enol of formula or a phenol of formula R 10 -OH, the groups R 1, R 2, R 3, R 4, R 5, R 6, R 7, R ₈ and R ₉ each independently representing a linear or branched alkyl group comprising from 1 to 20 carbon atoms, preferably from 1 to 10 carbon atoms and more preferably 1 to 5 carbon atoms, optionally substituted in whole or in part by F, Br, Cl or OH; and R10 represents a benzene ring optionally substituted in whole or in part by F, Br, Cl, OH or by alkyl groups as defined above.

Use according to one of claims 1 1 to 13, wherein the alcoholic compound is chosen from propan-1-ol, propan-2-ol, 2-perfluorohexylethanol, 1, 1, 1, 3.3, 3- hexafluoropropan-2-ol and mixtures thereof.

Use according to one of claims 1 1 to 14, wherein the ammonia and 2,3,3,3-tetrafluoroproene are combined in a mixture comprising:

from 1 to 60% of ammonia and from 40 to 99% of 2,3,3,3-tetrafluoropropene; preferably from 5 to 45% of ammonia and from 55 to 95% of 2,3,3,3-tetrafluoropropene;

preferably 18 to 26% of ammonia and 74 to 82% of 2,3,3,3-tetrafluoropropene;

preferably from 21 to 23% of ammonia and from 77 to 79% of 2,3,3,3-tetrafluoropropene. 16. Use according to one of claims 1 1 to 15, wherein the alcoholic compound is added to a mixture of ammonia and 2,3,3,3-tetrafluoropropene in a proportion of 0.1 to 20%, preferably from 0.5 to 10%, preferably from 1 to 5%, based on the sum of the three compounds.

17. Use according to one of claims 1 1 to 16, wherein the ammonia and 2,3,3,3-tetrafluoropropene are not combined with any third compound of heat transfer. A heat transfer apparatus comprising a vapor compression circuit containing a composition according to one of claims 1 to 9 as a heat transfer composition. 19. Installation according to claim 18, selected from mobile installations or stationary heat pump heating, air conditioning, refrigeration, freezing and Rankine cycles, and particularly among automotive air conditioning installations.

20. Installation according to claim 18, which is a car air conditioning installation.

A method of heating or cooling a fluid or a body by means of a vapor compression circuit containing a heat transfer fluid, said method comprising successively at least partial evaporation of the heat transfer fluid. heat, fluid compression heat transfer, at least partial condensation of the heat transfer fluid and expansion of the heat transfer fluid, wherein the heat transfer fluid is provided by a composition according to one of claims 1 to 9.

A method of reducing the environmental impact of a heat transfer facility comprising a vapor compression circuit containing an initial heat transfer fluid, said method comprising a step of replacing the initial heat transfer fluid in the vapor compression circuit by a final heat transfer fluid, the final heat transfer fluid having a GWP lower than the initial heat transfer fluid, wherein the final heat transfer fluid is provided by a composition according to one of claims 1 to 9.

23. Use of the composition according to one of claims 1 to 9 as a solvent. 24. Use of the composition according to one of claims 1 to

9 as an expansion agent.

25. Use of the composition according to one of claims 1 to 9 as a propellant, preferably for an aerosol.

26. Use of the composition according to one of claims 1 to 9 as a cleaning agent.