FIELD OF THE INVENTION
The present invention relates to compositions comprising 1,3,3,3-tetrafluoropropene, difluoromethane and at least one other compound. The compositions of the present invention are useful as refrigerants, heat transfer fluids, foam blowing agents, aerosol propellants, and fire suppression and fire extinguishing agents.

BACKGROUND OF THE INVENTION
The refrigeration industry has been working for the past few decades to find replacement refrigerants for the ozone depleting chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs), being phased out as a result of the Montreal Protocol. The solution for most refrigerant producers has been the commercialization of hydrofluorocarbon (HFC) refrigerants. The new HFC refrigerants, HFC-134a being the most widely used at this time, have zero ozone depletion potential and thus are not affected by the regulatory phase out as a result of the Montreal Protocol.
Currently, industry is facing regulations relating to global warming potential of refrigerants used in air-conditioning. Industry in general and the heat transfer industry in particular are continually seeking new fluorocarbon based mixtures that offer alternatives to, and are considered environmentally safer substitutes for, CFCs and HCFCs. It is generally considered important, with respect to heat transfer fluids, that any potential substitute must possess properties such as excellent heat transfer properties, chemical stability, low- or no-toxicity, non-flammability and/or lubricant compatibility etc.
Furthermore, it is generally considered desirable for CFC refrigerant substitutes to be effective without major engineering changes to conventional vapor compression technology currently used with CFC refrigerants.
Flammability is another important property for many applications. It is particularly important in heat transfer applications, to use compositions which are non-flammable. As used herein, the term “nonflammable” refers to compounds or compositions which are determined to be nonflammable as determined in accordance with ASTM standard E-681, dated 2002, which is incorporated herein by reference.
U.S. Patent Pub. No. 2004/0061091 discloses a refrigerant composition comprising 45-50 weight percent R134a, 45-50 weight percent R125, 3-5 weight percent R32, and 1-4 weight percent of the hydrocarbon component, the hydrocarbon component comprising one or more hydrocarbons selected from Group A and one or more hydrocarbons selected from Group B, wherein the Group A hydrocarbon comprises R290 and the Group B hydrocarbon comprises R600a.
U.S. Patent No. 9982180 discloses a heat transfer composition consisting of: (a) about 10% by weight of R32; (b) about 69% by weight of R125; (c) about 8% by weight of HFO1234yf and (d) about 13% by weight of trans HFO1234ze, with the weight percent being based on the total of the components (a)-(d) in the composition.
All the above composition have significant amount of R125 which contributes to higher GWP of these compositions.
Applicants have thus come to appreciate a need for compositions, and particularly heat transfer compositions, that are highly advantageous in heating and cooling systems and methods, particularly vapor compression heating and cooling systems, and even more particularly low temperature refrigerant systems, including systems which are used with and/or have been designed for use with R-404A.
The present invention provides a refrigerant composition comprising R1234ze, R32 and at least one compound selected from a group consisting of tetrafluoroethane, R125, R1234yf, heptafluoropropane, difluoroethane and CO2.

OBJECT OF THE INVENTION
The main object of the present invention is to provide a composition for use in refrigeration, air-conditioning, and heat pump systems comprising a 1,3,3,3-tetrafluoropropene, difluoromethane and at least one other compound.

SUMMARY OF THE INVENTION
The present invention provides a refrigerant composition comprising R1234ze, R32 and at least one compound selected from a group consisting of tetrafluoroethane, R125, R1234yf, heptafluoropropane, difluoroethane and CO2.
The present invention provides a refrigerant composition comprising:
10% by weight to 38% by weight of R32;
0% by weight to 50% by weight of tetrafluoroethane;
10% by weight to 38% by weight of R1234ze;
0% by weight to 15% by weight of R125;
0% by weight to 20% by weight of R1234yf;
0% by weight to 10% by weight of heptafluoropropane;
0% by weight to 15% by weight of difluoroethane; and
0% by weight to 5% by weight of CO2.
The present invention provides a refrigerant composition comprising R1234ze, R32, tetrafluoroethane and at least one compound selected from a group consisting of R125, R1234yf, heptafluoropropane, difluoroethane and CO2.
The present invention provides a refrigerant composition comprising:
10% by weight to 38% by weight of R32;
20% by weight to 50% by weight of tetrafluoroethane;
10% by weight to 38% by weight of R1234ze;
0% by weight to 15% by weight of R125;
0% by weight to 20% by weight of R1234yf;
0% by weight to 10% by weight of heptafluoropropane;
0% by weight to 15% by weight of difluoroethane; and
0% by weight to 5% by weight of CO2.

DETAILED DESCRIPTION OF THE INVENTION
The term tetrafluoroethane as used herein in the present invention refers to either 1,1,2,2-tetrafluoroethane or 1,1,1,2-tetrafluoroethane.
The term difluoroethane as used herein in the present invention refers to either 1,1-difluoroethane or 1,2-difluoroethane.
The term heptafluoropropane as used herein in the present invention refers to either 1,1,1,2,3,3,3-heptafluoropropane or 1,1,1,2,2,3,3-heptafluoropropane.
The various refrigerants as used in the present invention are described in the table below.
Table-1
Refrigerant Chemical name Chemical formula
R32 Difluoromethane CH2F2
R125 Pentafluoroethane CF3CHF2
R-134 1,1,2,2-tetrafluoroethane CHF2CHF2
R134a 1,1,1,2-tetrafluoroethane CH2FCF3
R152a 1,1-difluoroethane CHF2CH3
R152 1,2-difluoroethane CH2FCH2F
R227ea 1,1,1,2,3,3,3-heptafluoropropane CF3CHFCF3
R227ca 1,1,1,2,2,3,3-Heptafluoropropane CHF2CF2CF3
R1234yf 2,3,3,3-tetrafluoropropene CF3CF=CH2
R1234ze(E) Trans-1,3,3,3-tetrafluoropropene CF3CH=CHF
R1234ze(Z) Cis-1,3,3,3-tetrafluoropropene CF3CH=CHF

In an aspect, the present invention provides a refrigerant composition comprising:
10% by weight to 38% by weight of R32;
20% by weight to 50% by weight of tetrafluoroethane;
10% by weight to 38% by weight of R1234ze;
0% by weight to 15% by weight of R125;
0% by weight to 20% by weight of R1234yf;
0% by weight to 10% by weight of heptafluoropropane;
0% by weight to 15% by weight of difluoroethane; and
0% by weight to 5% by weight of CO2.
In another aspect, the present invention provides a refrigerant composition comprising:
20% by weight to 38% by weight of R32;
10% by weight to 15% by weight of R1234yf;
14% by weight to 38% by weight of R1234ze;
0% by weight to 15% by weight of R125;
25% by weight to 48% by weight of tetrafluoroethane;
0% by weight to 5% by weight of heptafluoropropane;
0% by weight to 5% by weight of difluoroethane; and
0% by weight to 2% by weight of CO2.
In an embodiment, the present invention provides a refrigerant composition comprising 10% by weight to 38% by weight of 1,3,3,3-tetrafluoropropene (R1234ze), 20% by weight to 38% by weight of difluoromethane (R32) and one or more compounds selected from pentafluoroethane (R125), 1,1,2,2-tetrafluoroethane (R134), 1,1,1,2-tetrafluoroethane (R134a), difluoroethane (R152), heptafluoropropane, difluoromethane (R32), 2,3,3,3-tetrafluoropropene (R1234yf) and CO2.
In another embodiment, the present invention provides a refrigerant composition comprising 10% by weight to 38% by weight of 1,3,3,3-tetrafluoropropene (R1234ze), 20% by weight to 38% by weight of difluoromethane (R32), 20% by weight to 50% by weight of tetrafluoroethane and one or more compounds selected from pentafluoroethane (R125), difluoroethane (R152a), heptafluoropropane, 2,3,3,3-tetrafluoropropene (R1234yf) and CO2.
In another embodiment, the present invention provides a refrigerant composition comprising:
20% by weight to 50% by weight of tetrafluoroethane;
0% by weight to 15% by weight of R125;
0% by weight to 20% by weight of R1234yf;
0% by weight to 10% by weight of heptafluoropropane;
0% by weight to 15% by weight of difluoroethane; and
0% by weight to 5% by weight of CO2.
In another embodiment, the present invention provides a refrigerant composition comprising 10% by weight to 38% by weight of 1,3,3,3-tetrafluoropropene (R1234ze), 20% by weight to 38% by weight of difluoromethane (R32), 20% by weight to 50% by weight of R134a, 0% by weight to 15% by weight of R125 and 0% by weight to 10% by weight of 227ea.
In another embodiment, the present invention provides a refrigerant composition comprising 10% by weight to 38% by weight of 1,3,3,3-tetrafluoropropene (R1234ze), 20% by weight to 38% by weight of difluoromethane (R32), 20% by weight to 50% by weight of tetrafluoroethane, more than 0% by weight to 15% by weight of R125, more than 0% by weight to 10% by weight of R227ea.
In another embodiment, the present invention provides a refrigerant composition comprising 10% by weight to 38% by weight of 1,3,3,3-tetrafluoropropene (R1234ze), 20% by weight to 38% by weight of difluoromethane (R32), 20% by weight to 50% by weight of tetrafluoroethane and more than 0% by weight to 15% by weight of R125.
In another embodiment, the present invention provides a refrigerant composition comprising 10% by weight to 38% by weight of 1,3,3,3-tetrafluoropropene (R1234ze), 20% by weight to 38% by weight of difluoromethane (R32), 20% by weight to 50% by weight of tetrafluoroethane, more than 0% by weight to 15% by weight of R125 and more than 0% by weight to 5% by weight of CO2.
In another embodiment, the present invention provides a refrigerant composition comprising 10% by weight to 38% by weight of 1,3,3,3-tetrafluoropropene (R1234ze), 20% by weight to 38% by weight of difluoromethane (R32), 20% by weight to 50% by weight of tetrafluoroethane, more than 0% by weight to 15% by weight of R125 and more than 0% by weight to 10% by weight of R152a.
In another embodiment, the present invention provides a refrigerant composition comprising 10% by weight to 38% by weight of 1,3,3,3-tetrafluoropropene (R1234ze), 20% by weight to 38% by weight of difluoromethane (R32), 20% by weight to 50% by weight of tetrafluoroethane, more than 0% by weight to 10% by weight of R227ea.
In another embodiment, the present invention provides a refrigerant composition comprising 10% by weight to 38% by weight of 1,3,3,3-tetrafluoropropene (R1234ze), 20% by weight to 38% by weight of difluoromethane (R32), 20% by weight to 50% by weight of tetrafluoroethane, more than 0% by weight to 15% by weight of R125, more than 0% by weight to 20% by weight of R1234yf.
In another embodiment, the present invention provides a refrigerant composition comprising 10% by weight to 38% by weight of 1,3,3,3-tetrafluoropropene (R1234ze), 20% by weight to 38% by weight of difluoromethane (R32), 20% by weight to 50% by weight of tetrafluoroethane.
In another embodiment, the present invention provides a refrigerant composition comprising 10% by weight to 38% by weight of 1,3,3,3-tetrafluoropropene (R1234ze), 20% by weight to 38% by weight of difluoromethane (R32), 20% by weight to 50% by weight of tetrafluoroethane, more than 0% by weight to 10% by weight of R152a.
In another embodiment, the present invention provides a refrigerant composition comprising 10% by weight to 38% by weight of 1,3,3,3-tetrafluoropropene (R1234ze), 20% by weight to 38% by weight of difluoromethane (R32), more than 0% by weight to 20% by weight of R1234yf and more than 0% by weight to 15% by weight of R125.
In an embodiment the said refrigerant compositions have global warming potential of less than 1500, preferably less than 1200. In another embodiment the said refrigerant compositions are used as replacement for R404A.
In first embodiment, the present invention provides a refrigerant composition 1, comprising:
30% by weight of R32;
15% by weight of R1234ze(E);
10% by weight of R125; and
45% by weight of R134a.
In second embodiment, the present invention provides a refrigerant composition 2, comprising:
28% by weight of R32;
15% by weight of R1234ze(E);
10% by weight of R125;
45% by weight of R134a; and
2% by weight of CO2.
In third embodiment, the present invention provides a refrigerant composition 3, comprising:
25% by weight of R32;
30% by weight of R1234ze(E);
15% by weight of R125;
25% by weight of R134a; and
5% by weight of difluoroethane.
In fourth embodiment, the present invention provides a refrigerant composition 4, comprising:
33.7% by weight of R32;
14.7% by weight of R1234ze(E);
5% by weight of R227ea; and
46.6% by weight of R134a.
In fifth embodiment, the present invention provides a refrigerant composition 5, comprising:
30% by weight of R32;
15% by weight of R1234yf;
10% by weight of R125;
30% by weight of R134a; and
15% by weight of R1234ze(E).
In sixth embodiment, the present invention provides a refrigerant composition 6, comprising:
25% by weight of R32;
30% by weight of R1234ze(E);
15% by weight of R125;
25% by weight of R134a; and
5% by weight of R227ea.
In seventh embodiment, the present invention provides a refrigerant composition 7, comprising:
30% by weight of R32;
34.7% by weight of R1234ze(E);
5.3% by weight of R125; and
30% by weight of R134a.
In eighth embodiment, the present invention provides a refrigerant composition 8, comprising:
35.5% by weight of R32;
36% by weight of R1234ze(E); and
28.5% by weight of R134a.
In ninth embodiment, the present invention provides a refrigerant composition 9, comprising:
37% by weight of R32;
23.5% by weight of R1234ze(E);
29.5% by weight of R134a; and
10% by weight of R152a.
In tenth embodiment, the present invention provides a refrigerant composition 10, comprising:
36% by weight of R32;
22% by weight of R1234ze(E);
14% by weight of R125; and
28% by weight of R134a.
In eleventh embodiment, the present invention provides a refrigerant composition 11, comprising:
35% by weight of R32;
35% by weight of R1234ze(E);
10% by weight of R125; and
20% by weight of R1234yf.
As used herein, a refrigerant is defined as a heat transfer fluid that undergoes a phase change from liquid to gas and back again during a cycle used to transfer of heat.
Non-azeotropic composition is a mixture of two or more substances that behaves as a simple mixture rather than a single substance. One way to characterize a non-azeotropic composition is that the vapor produced by partial evaporation or distillation of the liquid has a substantially different composition as the liquid from which it was evaporated or distilled, that is, the admixture distills/refluxes with substantial composition change.
The composition of the present invention has lower molecular weight thus has large enthalpy of evaporation. The larger the enthalpy of evaporation, the lower will be energy loss across compression and thus higher will be coefficient of performance COP value. The comparative data for molar mass and enthalpy of evaporation is given below (Table-2).
Table-2
Refrigerant Molar mass (Kg/Kmol) Enthalpy (kj/kg)
at -25°C in vapour phase at 25°C in liquid phase at -25°C in vapour phase at 25°C in liquid phase
R404a 97.604 97.604 352.33 236.3
Composition 1 81.133 81.133 410.4 237.54
Composition 2 87.488 87.488 386.02 236.8
Composition 3 84.083 84.083 403.01 237.21
Composition 4 79.189 79.189 416.89 237.78
Composition 5 82.165 82.165 402.69 237.55
Composition 6 87.488 87.488 393.51 236.47
Composition 7 82.027 82.027 408.3 229.69
Composition 8 78.285 78.285 417.73 238.03
Composition 9 77.692 77.692 424.50 238.48
Composition 10 78.372 78.372 388.60 238.08
Composition 11 80.752 80.752 401.23 237.91

Coefficient of performance (COP) is the amount of heat removed divided by the required energy input to operate the cycle. The higher the COP, higher is the energy efficiency. COP is directly related to the energy efficiency ratio (EER) that is the efficiency rating for refrigeration or air conditioning equipment at a specific set of internal and external temperatures. The composition of the present invention have higher COP as compared to known compositions of the art.
Further the compositions of the present invention have higher cooling capacity (CC) which leads to better coefficient of performance (COP) and therefore low power consumption which results in better performance as compared with the prior art composition R-404A as shown below.
Table-3
Compositions CC CC% COP COP%
R404A 1.37 100% 2.14 100%
Composition 1 1.44 105% 2.31 108.06%
Composition 2 1.42 104% 2.28 106.51%
Composition 3 1.41 103% 2.25 105.04%
Composition 4 1.48 108% 2.29 107.01%
Composition 5 1.39 101% 2.21 103.27%
Composition 6 1.32 96% 2.11 98.58%
Composition 7 1.34 98% 2.11 98.46%
Composition 8 1.43 104% 2.32 108.41%
Composition 9 1.42 104% 2.31 107.94%
Composition 10 1.44 105% 2.34 109.35%
Composition 11 1.47 107% 2.33 108.88%

Flammability is a term used to mean the ability of a composition to ignite and/or propagate a flame. Determination of whether a refrigerant compound or mixture is flammable or non-flammable can be done by testing under the conditions of ASTM-681. The compositions of the present inventions are mainly non-flammable.
Global warming potential (GWP) is an index for estimating relative global warming contribution due to atmospheric emission of a kilogram of a particular greenhouse gas compared to emission of a kilogram of carbon dioxide. GWP can be calculated for different time horizons showing the effect of atmospheric lifetime for a given gas. The GWP for the 100-year time horizon is commonly the value referenced. For mixtures, a weighted average can be calculated based on the individual GWPs for each compound. The standard GWP values for R22, R32, R125 and tetrafluoroethane has been taken from IIPCC 5th Assessment report 2014 (AR5). The GWP of the refrigerant mixture has been derived from mass fraction and the corresponding GWP values.
The compositions of the present invention has lower GWP value as compared with R-404 shown in the below table.
Table-4
Refrigerant GWP
R-404A 3920
Composition 1 1106
Composition 2 1092
Composition 3 978
Composition 4 1002
Composition 5 911
Composition 6 1139
Composition 7 763
Composition 8 613
Composition 9 649
Composition 10 1053
Composition 11 557

Ozone depletion potential (ODP) is a number that refers to the amount of ozone depletion caused by a substance. The ODP is the ratio of the impact on ozone of a chemical compared to the impact of a similar mass of CFC-11 (fluorotrichloromethane). Thus, the ODP of CFC-11 is defined to be 1.0. Other CFCs and HCFCs have ODPs that range from 0.01 to 1.0. HFCs have zero ODP because they do not contain chlorine or other ozone depleting halogens. The compositions of the present invention has zero ODP value.
In another embodiment of the present invention, the refrigerant compositions may contain optional components selected from the group consisting of lubricants, dyes (including Ultra Violet dyes), solubilizing agents, compatibilizers, stabilizers, tracers, perfluoropolyethers, anti-wear agents, extreme pressure agents, corrosion and oxidation inhibitors, metal surface energy reducers, metal surface deactivators, free radical scavengers, foam control agents, viscosity index improvers, pour point depressants, detergents, viscosity adjusters, and mixtures thereof. Indeed, many of these optional other components fit into one or more of these categories and may have qualities that lend themselves to achieve one or more performance characteristic.
In another embodiment of the present invention, the refrigerant compositions are non-azeotropic mixture.
In another embodiment of this aspect of the present invention, the refrigerant composition is preferably charged in liquid form.
The refrigerant composition of the present invention has higher specific heat capacity.
Table-5
Refrigerant Cp/Cv at -25°C in liquid phase Cp/Cv at -25°C in vapour phase Cp/Cv at 25°C in liquid phase
R404a 1.5327 1.1859 1.6678
Composition 1 1.5875 1.2064 1.7002
Composition 2 1.5631 1.1966 1.6918
Composition 3 1.5653 1.1911 1.6707
Composition 4 1.5933 1.2101 1.7056
Composition 5 1.5790 1.2044 1.7045
Composition 6 1.5624 1.1865 1.6683
Composition 7 1.5762 1.1964 1.6858
Composition 8 1.5891 1.2064 1.7063
Composition 9 1.5776 1.2041 1.6810
Composition 10 1.5988 1.2161 1.7284
Composition 11 1.5774 1.2031 1.7201

In another embodiment of this aspect, the present invention provides a refrigeration process using the refrigerant composition comprising the steps of:
a) condensing the refrigerant composition;
b) evaporating the refrigerant composition.
The vapor compression refrigeration cycle is given below.
T-S Diagram of Vapor Compression Cycle

Further, the refrigerant compositions of present invention have higher thermal conductivity.
Table-6
Refrigerant Thermal conductivity (mW/m-K) at -25°C in liquid phase Thermal conductivity (mW/m-K) at 25°C in liquid phase
R404a 82.918 62.714
Composition 1 116.16 90.103
Composition 2 104.76 80.781
Composition 3 112.68 87.680
Composition 4 119.89 93.288
Composition 5 112.83 87.293
Composition 6 110.41 85.705
Composition 7 116.87 90.91
Composition 8 121.89 94.80
Composition 9 120.17 94.04
Composition 10 118.95 91.93
Composition 11 114.92 88.73

The refrigerant compositions of the present invention find use in stationary or mobile air conditioning systems or heat exchanger systems. Preferably, the refrigerant compositions find use in domestic room air conditioning systems.
The present invention provides R404a replacement refrigerant compositions that are compatible with existing mineral oil and alike lubricants and do not require replacement of the expensive devices in the legacy system.
R32 is commercially available or may be prepared by methods known in the art, such as by dechlorofluorination of methylene chloride.
R125 is commercially available or may be prepared by methods known in the art, such as dechlorofluorination of 2,2-dichloro-1,1,1-trifluoroethane as described in US Patent No. 5,399,549, incorporated herein by reference.
Tetrafluoroethane is commercially available or may be prepared by methods know in the art, such as by the hydrogenation of 1,1-dichloro-1 ,2,2,2-tetrafluoroethane (i.e., CCI2FCF3 or CFC-114a) to 1 ,1 ,1 ,2-tetrafluoroethane.
Heptafluoropropane is commercially available or may be prepared by methods known in the art.
R1234yf and R1234ze(E) is commercially available or may be prepared by methods known in the art.
It is against this and other backgrounds, which shall be filed in a detailed manner in complete specifications, in due course, the present invention is brought out and explained in following non-limiting examples.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention and specific examples provided herein without departing from the spirit and scope of the invention. Thus, it is intended that the present invention covers the modifications and variations of this invention that come within the scope of any claims and their equivalents.

EXAMPLE
The refrigerant compositions according to the invention having components selected from the group consisting of R125, R134a, R32, R227ea, R1234yf, 1234ze(E) and R152a were prepared and tested with standard ASHRAE modeling program maintaining indoor at 5ºC dry bulb temperature (DBT) and 4ºC wet bulb temperature (WBT) and outdoor at 35 DBT and 24 WBT.
The properties of the various refrigerant compositions are shown in below tables.
Table-7
Properties at 25°C in liquid phase
R404a Composition 1 Composition 2 Composition 3

Pressure (bar) 12.546 11.812 12.309
11.339

Density (kg/m3) 1044.1 1113.2 1094.5
1104.3

Volume (m3/kg) 0.0009578 0.000898 0.00091368
0.00090553

Int. Energy (kj/kg) 235.1 236.48 235.67
236.19

Enthalpy (kj/kg) 236.3 237.54 236.8
237.21

Entropy (kJ/kg-K) 1.125 1.1296 1.1269
1.1285

Cv (kJ/kg-K) 0.92472 0.92017 0.91223
0.92679

Cp (kJ/kg-K) 1.5423 1.5645 1.5433
1.5484

Cp/Cv 1.6678 1.7002 1.6918
1.6707

Molar mass(Kg/Kmol) 97.604 81.133 87.488
87.083

Thermal conductivity (mW/m-K) 62.714 90.103 80.781
87.68
Viscosity (uPa-s) 128.27 150.57 139.22 150.04

Table-8
Properties at 25°C in vapour phase
R404a Composition 1 Composition 2 Composition 3
Pressure (bar) 12.412 9.8456 10.597
9.1359

Density (kg/m3) 65.274 39.331 46.78
37.43

Volume (m3/kg) 0.01532 0.025425 0.021377
0.026717

Int. Energy (kj/kg) 357.54 409.72 387.83
396.34

Enthalpy (kj/kg) 376.55 434.75 410.48
429.36

Entropy (kJ/kg-K) 1.5958 1.7992
1.7156
1.7824

Cv (kJ/kg-K) 0.89151 0.85685 0.86448
0.85355

Cp (kJ/kg-K) 1.2214 1.1377 1.1499
1.1059

Cp/Cv 1.3701 1.3278 1.3302
1.2957

Molar mass(Kg/Kmol) 97.604 81.133 87.488
84.083

Thermal
conductivity (mW/m-K) 17.003
14.435

14.581

14.389

Viscosity (uPa-s) 12.229 12.207 12.334 12.364

Table-9
Properties at -25°C in liquid phase
R404a Composition 1 Composition 2 Composition 3
Pressure (bar) 2.5373 2.293 2.4395
2.198

Density (kg/m3) 1238.6 1289.4 1277.9
1276.2

Volume (m3/kg) 0.000807 0.000776 0.00078252
0.00078358

Int. Energy (kj/kg) 166.21 164.46 165.42 164.72
Enthalpy (kj/kg) 166.41 164.64 165.61
164.89

Entropy (kJ/kg-K) 0.87225 0.86531 0.86912
0.86624

Cv (kJ/kg-K) 0.84874 0.8689 0.85464
0.87540

Cp (kJ/kg-K) 1.3008 1.3794 1.3359
1.3703

Cp/Cv 1.5327 1.5875 1.5631
1.5653

Molar mass(Kg/Kmol) 97.604 81.133 87.488 84.083
Thermal conductivity
(mW/m-K) 82.918 116.16

104.76
112.68

Viscosity (uPa-s) 249.25
279.77
257.95
280.44

Table-10
Properties at -25°C in vapour phase
R404a Composition 1 Composition 2 Composition 3
Pressure (bar) 2.4752 1.6639
1.8868
1.5290

Density (kg/m3) 12.797 6.9298
8.5463
6.5761

Volume (m3/kg) 0.07814 0.1443
0.11701
0.15207

Int. Energy (kj/kg) 332.99 386.39
363.94
379.76

Enthalpy (kj/kg) 352.33 410.4
386.02
403.01

Entropy (kJ/kg-K) 1.6226 1.8721
1.7697
1.8441

Cv (kJ/kg-K) 0.7316 0.70225
0.70979
0.70923

Cp (kJ/kg-K) 0.86763 0.84718
0.84931
0.84474

Cp/Cv 1.1859 1.2064
1.1966
1.1911

Molar mass(Kg/Kmol) 97.604 81.133
87.488
84.083

Thermal conductivity (mW/m-K) 10.868
9.9824
9.9927
9.9486

Viscosity (uPa-s) 10.039
10.044
10.111
10.030

WE CLAIM:
1. A refrigerant composition comprising 10% by weight to 38% by weight of 1,3,3,3-tetrafluoropropene (R1234ze), 20% by weight to 38% by weight of difluoromethane (R32) and one or more additional compound selected from pentafluoroethane (R125), tetrafluoroethane (R134), difluoroethane (R152), heptafluoropropane (R227), 2,3,3,3-tetrafluoropropene (R1234yf) and CO2.
2. The refrigerant composition, as claimed in claim 1, wherein said one or additional compounds are selected from the group comprising:
20% by weight to 50% by weight of tetrafluoroethane;
0% by weight to 15% by weight of R125;
0% by weight to 20% by weight of R1234yf;
0% by weight to 10% by weight of heptafluoropropane;
0% by weight to 15% by weight of difluoroethane; and
0% by weight to 5% by weight of CO2.
3. The refrigerant composition, as claimed in claim 1, wherein said additional compound is essentially 20% by weight to 50% by weight of R134a.
4. The refrigerant composition, as claimed in claim 1, wherein said additional compounds essentially consist of 20% by weight to 50% by weight of R134a, more than 0% by weight to 15% by weight of R125 and more than 0% by weight to 5% by weight of CO2.
5. The refrigerant composition, as claimed in claim 1, wherein said additional compounds essentially consist of 20% by weight to 50% by weight of R134a, 0% by weight to 15% by weight of R125 and 0% by weight to 10% by weight of 227ea.
6. The refrigerant composition, as claimed in claim 1, wherein said additional compounds essentially consist of 20% by weight to 50% by weight of R134a, 0% by weight to 15% by weight of R125 and 0% by weight to 15% by weight of difluoroethane.
7. The refrigerant composition, as claimed in claim 1, wherein said additional compounds essentially consist of 0% by weight to 50% by weight of R134a, more than 0% by weight to 15% by weight of R125 and more than 0% by weight to 20% by weight of R1234yf.
8. The refrigerant composition as claimed in claim 1, has global warming potential of less than 1500, preferably less than 1200.
9. The refrigerant compositions as claimed in previous claims are non-azeotropic compositions.
10. The refrigerant compositions as claimed in previous claims are used as replacement for R404A.