Refrigerant composition and its use

Abstract

The present invention provides a refrigerant composition that can operate efficiently in automotive heat pump systems. [Solution] A refrigerant composition comprising 1,1-difluoroethylene (R-1132a), difluoromethane (R-32), 1,1-difluoroethane (R-152a), and at least one tetrafluoropropene refrigerant compound selected from the group consisting of 2,3,3,3-tetrafluoropropene (R-1234yf) and 1,3,3,3-tetrafluoropropene (R-1234ze(E)).

Description

Technical Field

[0001] The present invention relates to a refrigerant composition, more specifically, a refrigerant composition containing 1,1-difluoroethylene (R-1132a; vinylidene fluoride) which is useful in mobile or automotive heat pump systems, particularly systems for electric vehicles. The listing or discussion of prior published documents or any background art in this specification should not necessarily be construed as an admission that the document or background art is part of the state of the art or is common general knowledge.

Background Art

[0002] The introduction of electric vehicles without an internal combustion engine for supplying a heat source to the passenger compartment means that there is a growing interest in the use of vehicle air conditioning units that operate as heat pumps in cold weather. This can be achieved by reversing the direction of the refrigerant flow around the air conditioning circuit so that the refrigerant evaporates at a low temperature using heat from the ambient air and condenses at a high temperature with respect to the air circulated in the passenger compartment. By using the air conditioning system in this way, it is possible to supply more heat to the passenger compartment per unit of electrical energy taken from the battery than when used to provide heat by electrical resistance heating of the incoming passenger compartment air.

[0003] The need to heat the passenger's air is highest when the outside air is coldest, making it particularly difficult to operate the air conditioning unit as a heat pump. In particular: · The ambient atmospheric temperature can drop to -25 to -30 °C, i.e., to operate the heat pump under these conditions, the refrigerant needs to evaporate at a temperature below -30 °C. · The passenger's air from the vents to the passenger compartment is ideally heated to 40 to 50 °C, i.e., the refrigerant must condense at a temperature higher than 40 °C. · To avoid air intrusion into the system, the evaporation pressure of the refrigerant needs to be kept below 1 atmosphere. The same refrigerant should perform at an acceptable level in the operating modes of air conditioning and heat pumps. • For a new fluid to comply with EU F-Gas regulations, its global warming potential (GWP) must be less than 150. Following the phase-out of dichlorodifluoromethane (R-12), a CFC with a high ozone depletion potential, 1,1,1,2-tetrafluoroethane (R-134a) became the refrigerant of choice in automotive air conditioning systems in recent years. Subsequently, the EU F-Gas Directive was implemented, mandating a global warming potential (GWP) limit of 150 for new mobile air conditioning (MAC) systems in vehicles. As a result, the use of R-134a is now largely being replaced by the use of flammable 2,3,3,3-tetrafluoropropene (R-1234yf) in new systems in Europe. R-1234yf is slightly less efficient than R-134a, and new system designs now include additional equipment (internal heat exchangers) to compensate for the reduced efficiency.

[0004] Mobile air conditioning systems using either R-134a or R-1234yf as a refrigerant cannot operate efficiently in heat pump mode when the ambient temperature is below approximately -15 to -20°C, because the evaporation pressure at the required evaporation temperature falls below atmospheric pressure. Carbon dioxide (R-744) is a high-pressure refrigerant that can function well as a low-temperature heat pump fluid. However, carbon dioxide is known to perform worse (less energy-efficient) than R-134a or R-1234yf in air conditioning modes for automotive systems at moderate to high ambient temperatures.

[0005] There is a need for refrigerant compositions that can operate efficiently in mobile heat pump systems for heating vehicles, particularly electric vehicles, such as automotive heat pump systems. A working refrigerant fluid for use in integrated mobile heat pump / air conditioner systems for electric vehicles needs to be found that can operate as a working fluid in a heat pump cycle with a positive number (greater than atmospheric intake pressure) at an evaporation temperature of approximately -30°C, while also providing acceptable performance (energy efficiency) when used in air conditioning mode. Furthermore, all new refrigerants developed for automotive systems must have a global warming potential (GWP) of less than 150 to comply with European environmental laws. [Overview of the project]

[0006] The inventors have discovered that a composition of 1,1-difluoroethylene (R-1132a; vinylidene fluoride) with other hydrofluorocarbon refrigerants may offer improved performance compared to R-1234yf when used in automotive heat pump systems, particularly for electric vehicles. This composition can also provide acceptable performance when used in air conditioning mode. It can extract heat from the environment at lower ambient temperatures than is possible with R-1234yf or R-134a, and furthermore, it can provide improved energy efficiency. This is a particularly desirable combination of properties for use in electric vehicles, where battery energy must otherwise be used to provide heat for passenger comfort.

[0007] Accordingly, in a first aspect, the present invention provides for the use of a composition comprising 1,1-difluoroethylene (R-1132a) and at least one fluorocarbon refrigerant compound selected from the group consisting of 2,3,3,3-tetrafluoropropene (R-1234yf), difluoromethane (R-32), 1,3,3,3-tetrafluoropropene (R-1234ze(E)), and 1,1-difluoroethane (R-152a) as a refrigerant in a heat pump system of an electric vehicle.

[0008] Conveniently, the refrigerant composition further comprises at least one of trifluoroethylene (R-1123), trifluoroiodomethane (CF3I), carbon dioxide (R-744, CO2), and 1,1,1,2-tetrafluoroethane (R-134a).

[0009] In a further embodiment, the present invention provides for the use of a composition comprising 1,1-difluoroethylene (R-1132a) and trifluoroiodomethane (CF3I) as a refrigerant in a heat pump system of an electric vehicle. Preferably, the refrigerant composition comprises about 1 to about 30% by weight of R-1132a and about 70 to about 99% by weight of CF3I.

[0010] A preferred composition of the present invention contains 1 to 30% by weight or 1 to 20% by weight, for example, about 3 to 15% by weight of 1,1-difluoroethylene (R-1132a), based on the total weight of the refrigerant composition.

[0011] In one embodiment, the refrigerant composition comprises 1,1-difluoroethylene (R-1132a), at least one tetrafluoropropene refrigerant compound selected from the group consisting of 2,3,3,3-tetrafluoropropene (R-1234yf) and 1,3,3,3-tetrafluoropropene (R-1234ze(E)), and optionally difluoromethane (R-32). In this embodiment, R-1132a is preferably present in an amount of 1 to 20% by weight based on the total weight of the refrigerant composition. If difluoromethane is included, it is preferably present in an amount of 1 to 21% by weight based on the total weight of the refrigerant composition. Whether the composition of this first embodiment is a two-component composition or a three-component composition, the selected tetrafluoropropene gives the remainder of the refrigerant composition.

[0012] Preferred compositions of this first embodiment include: (i) A two-component refrigerant composition comprising 1 to 20% by weight of 1,1-difluoroethylene (R-1132a) and 99 to 80% by weight of 2,3,3,3-tetrafluoropropene (R-1234yf). (ii) A two-component refrigerant composition comprising 1 to 20% by weight of 1,1-difluoroethylene (R-1132a) and 99 to 80% by weight of 1,3,3,3-tetrafluoropropene (R-1234ze(E)). (iii) A three-component refrigerant composition comprising 1 to 20% by weight of 1,1-difluoroethylene (R-1132a), 1 to 21% by weight of difluoromethane (R-32), and 59 to 98% by weight of 2,3,3,3-tetrafluoropropene (R-1234yf). (iv) A three-component refrigerant composition comprising 1 to 20% by weight of 1,1-difluoroethylene (R-1132a), 1 to 21% by weight of difluoromethane (R-32), and 59 to 98% by weight of 1,3,3,3-tetrafluoropropene (R-1234ze(E)).

[0013] When trifluoroiodomethane (CF3I) is included in the composition of the present invention, it is typically present in a smaller amount than R-1234yf or R-1234ze(E). A preferred CF3I-containing composition of the present invention includes R-1132a, R-32, R-1234yf, and CF3I, such as 1-20% by weight of R-1132a, 1-21% by weight of R-32, 5-40% by weight of CF3I, and 19-93% by weight of R-1234yf.

[0014] When carbon dioxide (CO2) is included in the composition of the present invention, the total content of R-1132a and CO2 is typically less than about 30% by weight, such as less than about 20% by weight. A preferred CO2-containing composition of the present invention contains R-1132a, R-32, R-1234yf, and CO2.

[0015] In another embodiment, the refrigerant composition includes R-1132a, R-152a, and optionally R-32. Preferred compositions in this embodiment include: (i) A two-component refrigerant composition containing 1 to 30% by weight of R-1132a and 99 to 70% by weight of R-152a. (ii) A three-component refrigerant composition comprising 1 to 20% by weight of R-1132a, 1 to 10% by weight of R-32, and 70 to 98% by weight of R-152a.

[0016] In further embodiments, the refrigerant composition comprises, and optionally consists of, R-1132a, R-152a, and R-1234yf. Typically, the amount of R-1132a present in such a composition is in the range of 1 to 20% by weight. Preferred compositions of this embodiment include compositions comprising 2 to 14% by weight of R-1132a (e.g., 4 to 10% by weight), 2 to 96% by weight of R-152a, and 2 to 96% by weight of R-1234yf. Preferably, R-152a is present in such a composition in an amount of 4 to 80% by weight, e.g., 5 to 30% by weight. Preferably, R-1234yf is present in such a composition in an amount of 4 to 96% by weight, e.g., 60 to 94% by weight of R-1234yf.

[0017] In further embodiments, the refrigerant composition comprises at least one tetrafluoropropene refrigerant compound selected from the group consisting of R-1132a, R-32, R-152a, and R-1234yf and R-1234ze(E). Preferred compositions of this third embodiment include: (i) A four-component refrigerant composition comprising 1 to 20% by weight of 1,1-difluoroethylene (R-1132a), 1 to 21% by weight of difluoromethane (R-32), and a mixture of 1,1-difluoroethane (R-152a) and 2,3,3,3-tetrafluoropropene (R-1234yf) in any ratio between 59 and 98% by weight. (ii) A four-component refrigerant composition comprising 1 to 20% by weight of 1,1-difluoroethylene (R-1132a), 1 to 21% by weight of difluoromethane (R-32), and a mixture of 1,1-difluoroethane (R-152a) and 1,3,3,3-tetrafluoropropene (R-1234ze(E)) in any ratio between 59 and 98% by weight.

[0018] The refrigerant compositions of the present invention may also contain R-134a in an amount typically of about 1 to about 10% by weight, based on the total weight of the refrigerant composition. Preferred R-134a-containing compositions include: R-1132a, CF3I and R-134a; R-1132a, R-1234yf and R-134a; R-1132a, R-1234ze(E) and R-134a; R-1132a, R-1234yf, R-32 and R-134a; R-1132a, R-1234ze(E), R-32 and R-134a; R-1132a, R-1234yf, CF3I and R-134a; R-1132a, R-1234ze(E), CF3I and R -134a; R-1132a, R-152a and R-134a; R-1132a, R-152a, R-32 and R-134a; R-1132a, R-1234yf, R-152a and R-134a (such as approximately 1 to approximately 20 wt% R-1132a, approximately 5 to approximately 25 wt% R-152a, approximately 1 to approximately 10 wt% R-134a and approximately 93 to approximately 45 wt% R-1234yf); and those containing R-1132a, R-1234ze(E), R-152a and R-134a.

[0019] When trifluoroethylene (R-1123) is included in the compositions of the present invention, it is typically present in amounts less than about 30% by weight, such as less than about 20% by weight. Preferred R-1123-containing compositions of the present invention include R-1132a, R-1123, and R-1234yf, preferably containing about 1 to about 20% by weight of R-1132a, about 1 to about 20% by weight of R-1123, and about 98 to about 60% by weight of R-1234yf. Preferred R-1123-containing compositions are those in which the maximum molar content of R-1123 in the blend as formulated and in the vapor in equilibrium with the blend is less than about 55% at temperatures of -40°C or higher. This is to mitigate the risk of disproportionation (self-reaction) of R-1123. The compositions described above and the compositions listed in the table (see Examples 24-27 below) are expected to meet these criteria.

[0020] Certain compositions of the present invention comprise R-1132a and R-32, preferably from about 68 to about 99% by weight of R-1132a and from about 1 to about 32% by weight of R-32, such as from about 72 to about 96% by weight of R-1132a and from about 4 to about 28% by weight of R-32, and optionally consist essentially of these. These compositions may substantially contain no R-1234yf.

[0021] Further compositions of the present invention comprise R-1132a, R-32 and CO2, preferably from about 1 to about 20% by weight of R-1132a, from about 1 to about 32% by weight of R-32 and from about 50 to about 95% by weight of CO2, such as from about 2 to about 15% by weight of R-1132a, from about 2 to about 32% by weight of R-32 and from about 55 to about 93% by weight of CO 2、 For example, they comprise from about 64 to about 93% by weight of carbon dioxide, from about 2 to about 25% by weight of difluoromethane and from about 2 to about 14% by weight of R-1132a, such as from about 65 to about 93% by weight of carbon dioxide, from about 2 to about 22% by weight of difluoromethane and from about 2 to about 14% by weight of R-1132a, and optionally consist essentially of these. These compositions may substantially contain no R-1234yf.

[0022] By "substantially free of", the inventors mean that the compositions of the present invention contain no more than 0.5% by weight, preferably no more than 0.1% by weight, of the stated component, based on the total weight of the composition.

[0023] As used herein, all % amounts referred to in the compositions of this specification, including the claims, are by weight based on the total weight of the composition, unless otherwise specified.

[0024] In one embodiment, the composition may consist essentially of the recited components. By the term "consisting essentially of", the inventors mean that the compositions of the present invention do not substantially contain additional (hydro)(fluoro) compounds (e.g., (hydro)(fluoro) alkanes or (hydro)(fluoro) alkenes) known to be used in heat transfer compositions, particularly other components. The term "consisting of" is included within the meaning of "consisting essentially of".

[0025] To avoid doubt, it should be understood that the upper and lower limits of the ranges of amounts of the components in the compositions of the invention described herein can be replaced in any manner, as long as the resulting ranges fall within the broadest scope of the invention.

[0026] When used in a heat pump or a combination of a heat pump and an air conditioning system, the refrigerant composition is typically combined with a lubricant. Suitable lubricants include polyol esters such as neopentyl polyol esters, and polyalkylene glycols, preferably capped at one or both ends with an alkyl group, e.g., C 1~4 alkyl group.

[0027] The composition of the present invention has a zero ozone depletion potential.

[0028] Typically, the composition of the present invention has a GWP of less than about 150, e.g., less than about 100, e.g., less than about 50.

[0029] Typically, the composition of the present invention has a reduced risk of flammability when compared to R-1132a.

[0030] Flammability can be determined according to ASHRAE Standard 34 incorporating ASTM Standard E-681 using the test method according to page 34 of the appendix dated 2004, the entire content of which is incorporated herein by reference. In one embodiment, the composition has one or more of the following characteristics compared to R-1132a alone: ​​(a) a higher lower flammability limit, (b) a higher ignition energy, (c) a higher autoignition temperature, or (d) a lower flame propagation rate. Preferably, the composition of the present invention is less flammable than R-1132a in one or more of the following: lower flammability limit at 23°C, lower flammability limit at 60°C, width of the flammability range at 23°C or 60°C, autoignition temperature (pyrolysis temperature), minimum ignition energy in dry air, or combustion rate. The flammability limit and combustion rate are determined according to the method specified in ASHRAE 34, and the autoignition temperature is determined in a 500 ml glass flask according to the method of ASTM E659-78.

[0031] A preferred composition of the present invention is one having a laminar combustion rate of less than 10 cm / second, and particularly preferred is a composition in which both the compound and the "worst-case fractionated compound" have a combustion rate of less than 10 cm / second, i.e., a composition classified as "2L" flammability according to ASHRAE Standard 34.

[0032] In preferred embodiments, the compositions of the present invention are non-flammable. For example, the compositions of the present invention are non-flammable at a test temperature of 60°C using the ASHRAE-34 methodology. Advantageously, a mixture of vapors present in equilibrium with the compositions of the present invention at any temperature between approximately -20°C and 60°C is also non-flammable. In some applications, it may not be necessary to classify the compound as non-flammable according to the ASHRAE-34 method. For example, if it is physically impossible to create a flammable mixture by leaking the cooling device filler into the surroundings, it is possible to develop a fluid whose flammability limit in air is sufficiently reduced to make it safe for use in that application.

[0033] In one embodiment, the composition of the present invention is flammable and can be classified as either non-flammable (Class 1) or a slightly flammable fluid (Class 2L) with a flame velocity of less than 10 cm / sec, according to the ASHRAE standard 34 classification system.

[0034] The composition of the present invention preferably has a temperature gradient in the evaporator or condenser of less than about 15K, more preferably less than about 10K, and even more preferably less than about 5K.

[0035] The compositions of the present invention are useful in mobile applications, such as automotive heat pump applications, and exhibit acceptable performance in mobile air conditioning applications. The compositions may offer particular benefits when heat pump and / or air conditioning systems are used in electric vehicles, whether pure electric or hybrid vehicles.

[0036] Unless otherwise specified, the term "electric vehicle" should be understood to refer to both pure electric vehicles and vehicles that use electricity as one of several means of propulsion, such as hybrid vehicles.

[0037] Preferably, in the use of the present invention, the refrigerant composition evaporates at a temperature of less than about -30°C, thereby enabling heat pump operation at low ambient temperatures of -25 to -30°C.

[0038] Accordingly, in a further embodiment, the present invention provides an electric vehicle equipped with a heat pump and / or air conditioning system using a refrigerant composition according to a first embodiment of the present invention. The refrigerant composition may be as described in any of the above embodiments.

[0039] Accordingly, the present invention also provides (i) a method for cooling an electric vehicle, comprising evaporating a refrigerant composition of the present invention near an object to be cooled, and (ii) a method for heating an electric vehicle, comprising condensing a refrigerant composition of the present invention near an object to be heated.

[0040] The present invention will be illustrated by the following non-limiting embodiments. [Examples]

[0041] Here, the present invention will be described by theoretical cycle modeling of the performance of the selected composition of the present invention in a heat pump cycle and an air conditioning cycle. R-1234yf was selected as the reference refrigerant for both cycles.

[0042] Modeling was performed in Microsoft Excel using NIST REFPROP10 as the thermodynamic data source. To measure the vapor pressure of binary mixtures of R-1132a / R-32 or R-1132a / R-1234yf over a temperature range of -70C to +40C, a constant-volume apparatus was used to first investigate the phase equilibrium of the R-1132a mixture with R-32 and R-1234yf. This data was then regressed to obtain binary interaction parameters for use in REFPROP to reproduce the experimental data.

[0043] The following conditions were assumed for the heat pump cycle. [Table 1]

[0044] The modeled cycle included the injection of intermediate-pressure refrigerant vapor to improve cycle performance. For each composition, the optimal injection pressure was determined to maximize the coefficient of performance (COP) for heating.

[0045] The results of the selected two- and three-component mixtures of the present invention are summarized in Examples 1-8 below. It was found that incorporating R-1132a increased the COP (energy efficiency) and increased the refrigerant evaporation pressure compared to R-1234yf. It also showed a reduction in the volumetric flow rate of the refrigerant that needs to be pumped through the system, and a decrease in pressure drop losses compared to R-1234yf. For comparison, modeled performance data for two commercially available blends (R-454C and R-516A) are also shown in the table below.

[0046] [Table 2]

[0047] [Table 3]

[0048] [Table 4]

[0049] [Table 5]

[0050] [Table 6]

[0051] [Table 7]

[0052] [Table 8]

[0053] [Table 9]

[0054] [Table 10]

[0055] Next, the air conditioning performance was evaluated using the following theoretical cycle modeling conditions that represent operation under high-temperature ambient conditions (Examples 9 and 10).

[0056] [Table 11]

[0057] It was found that improved heating mode performance can be obtained, and that cooling mode performance can be obtained in which the theoretical COP for cooling is within approximately 10% of the theoretical COP obtained with R-1234yf. The fluid of the present invention operates at higher pressures and lower mass / volume flow rates compared to R-1234yf, meaning that efficiency losses in actual systems due to pressure drop effects are also reduced compared to R-1234yf.

[0058] [Table 12]

[0059] [Table 13]

[0060] The performance of the selected two-component, three-component, and four-component compositions of the present invention in a heat pump cycle is further demonstrated in Examples 11 to 34 below. Similarly, R-1234yf was selected as the reference refrigerant for the cycle.

[0061] The following operating conditions were assumed. [Table 14]

[0062] In summary, the modeled performance data demonstrates the following advantages of the composition according to the present invention. (a) Essentially equivalent or improved energy efficiency (COP) in heated mode cycle operation compared to R-1234yf alone. (b) The increased evaporation pressure results in a greater capacity and improved ability to operate at lower ambient temperatures.

[0063] Furthermore, the performance of selected two-component blends containing R-1132a and R-32, as well as three-component blends containing R-1132a, R-32, and CO2, in air conditioning cycles is demonstrated in Examples 35-37 below.

[0064] [Table 15]

[0065] [Table 16]

[0066] [Table 17]

[0067] [Table 18]

[0068] [Table 19]

[0069] [Table 20]

[0070] [Table 21]

[0071] [Table 22]

[0072] [Table 23]

[0073] Table 24

[0074] Table 25

[0075] Table 26

[0076] Table 27

[0077] Table 28

[0078] Table 29

[0079] Table 30

[0080] Table 31

[0081] Table 32

[0082] Table 33

[0083] Table 34

[0084] [Table 35]

[0085] [Table 36]

[0086] [Table 37]

[0087] [Table 38]

[0088] [Table 39]

[0089] [Table 40]

[0090] [Table 41]

[0091] Example 38 shows performance data for a three-component composition containing 8 wt% R-1132a, 11 wt% R-32, and 81 wt% R-1234yf in a mobile heat pump / air conditioner system for use in an electric vehicle. System performance was tested under three test conditions using the same refrigerant charge size as for R-1234yf, in a cooling mode (air conditioning) compliant with SAE standard J2765. The compressor speed was reduced according to standard techniques for comparing different refrigerants to ensure this blend achieved the same cooling capacity as R-1234yf at each test point.

[0092] The results are shown below and illustrated in Figures 2 and 3. The tested compositions consistently provided improved energy efficiency at each test point, with the coefficient of performance (COP) varying from 110% to 125% of the R-1234yf value.

[0093] [Table 42]

[0094] [Table 43]

[0095] The present invention encompasses the following embodiments. [Aspect 1] Use as a refrigerant in a heat pump system in an electric vehicle of a composition comprising 1,1-difluoroethylene (R-1132a) and at least one fluorocarbon refrigerant compound selected from the group consisting of 2,3,3,3-tetrafluoropropene (R-1234yf), difluoromethane (R-32), 1,3,3,3-tetrafluoropropene (R-1234ze(E)), and 1,1-difluoroethane (R-152a). [Aspect 2] The use according to Embodiment 1, wherein the refrigerant composition further comprises at least one of trifluoroethylene (R-1123), trifluoroiodomethane (CF3I), carbon dioxide (R-744, CO2), and 1,1,1,2-tetrafluoroethane (R-134a). [Aspect 3] The use of a composition comprising 1,1-difluoroethylene (R-1132a) and trifluoroiodomethane (CF3I) as a refrigerant in a heat pump system in an electric vehicle, preferably the refrigerant composition comprising about 1 to about 30% by weight of R-1132a and about 70 to about 99% by weight of CF3I. [Aspect 4] The use according to Embodiment 1, wherein the refrigerant composition comprises R-1132a, R-152a, and R-1234yf, preferably 2 to 14% by weight of R-1132a, 2 to 96% by weight of R-152a, and 2 to 96% by weight of R-1234yf, for example, 4 to 10% by weight of R-1132a, 2 to 30% by weight of R-152a, and 60 to 94% by weight of R-1234yf. [Aspect 5] The use according to Embodiment 1, wherein the refrigerant composition comprises R-1132a, at least one tetrafluoropropene refrigerant compound selected from the group consisting of R-1234yf and R-1234ze(E), and optionally difluoromethane (R-32). [Aspect 6] The use according to any one of embodiments 1 to 5, wherein the R-1132a is present in an amount of 1 to 30% by weight, preferably 1 to 20% by weight, for example, about 3 to about 15% by weight, based on the total weight of the refrigerant composition. [Aspect 7] The use according to embodiment 5 or 6, wherein R-32 is present in an amount of 1 to 21% by weight based on the total weight of the refrigerant composition. [Aspect 8] The refrigerant composition is 1-20% by weight of R-1132a and 99-80% by weight of R-1234yf; R-1132a in 1-20% by weight and R-1234ze(E) in 99-80% by weight; 1-20% by weight of R-1132a, 1-21% by weight of R-32, and 59-98% by weight of R-1234yf; or The use according to embodiment 5, comprising 1-20% by weight of R-1132a, 1-21% by weight of R-32, and 59-98% by weight of R-1234ze(E). [Aspect 9] The use according to any one of embodiments 5 to 8, wherein the refrigerant composition further contains CF3I, preferably in an amount less than that of R-1234yf or R-1234ze(E). [Aspect 10] The use according to embodiment 9, wherein the refrigerant composition comprises R-1132a, R-32, R-1234yf, and CF3I. [Aspect 11] The use according to any one of embodiments 5 to 8, wherein the refrigerant composition further contains CO2 (R-744), and preferably the total content of CO2 and R-1132a is less than about 30% by weight, for example less than about 20% by weight. [Aspect 12] The use according to embodiment 11, wherein the refrigerant composition comprises R-1132a, R-32, R-1234yf, and CO2. [Aspect 13] The use according to embodiment 1, 2, or 6, wherein the refrigerant composition comprises R-1132a, R-152a, and optionally R-32. [Aspect 14] The refrigerant composition is 1-30% by weight of R-1132a and 99-70% by weight of R-152a; or The use according to embodiment 13, comprising 1 to 20% by weight of R-1132a, 1 to 10% by weight of R-32, and 70 to 98% by weight of R-152a. [Aspect 15] The use according to embodiment 1, 2, or 6, wherein the refrigerant composition comprises R-1132a, R-32, R-152a, and at least one tetrafluoropropene refrigerant compound selected from the group consisting of R-1234yf and R-1234ze(E). [Aspect 16] The refrigerant composition is A mixture of 1-20% by weight of R-1132a, 1-21% by weight of R-32, and 59-98% by weight of R-152a and R-1234yf; or The use according to embodiment 15, comprising 1 to 20% by weight of R-1132a, 1 to 21% by weight of R-32, and 59 to 98% by weight of a mixture of R-152a and R-1234ze(E). [Aspect 17] The use according to any one of embodiments 3 to 9 or 13 to 16, wherein the refrigerant composition further comprises R-134a, preferably in an amount of about 1 to about 10% by weight of R-134a. [Aspect 18] The use according to embodiment 2, wherein the refrigerant composition comprises R-1132a, R-1123, and R-1234yf, preferably about 1 to about 20% by weight of R-1132a, about 1 to about 20% by weight of R-1123, and about 98 to about 60% by weight of R-1234yf. [Aspect 19] The use according to Embodiment 2, wherein the refrigerant composition comprises R-1132a, R-152a, R-134a and R-1234yf, preferably about 1 to about 20% by weight of R-1132a, about 5 to about 25% by weight of R-152a, about 1 to about 10% by weight of R-134a and about 93 to about 45% by weight of R-1234yf. [Aspect 20] The use according to Embodiment 1, wherein the refrigerant composition comprises R-1132a and R-32, preferably about 68 to about 99% by weight of R-1132a and about 1 to about 32% by weight of R-32, for example, about 72 to about 96% by weight of R-1132a and about 4 to about 28% by weight of R-32. [Aspect 21] The refrigerant composition comprises R-1132a, R-32, and CO2, preferably about 1 to about 20% by weight of R-1132a, about 1 to about 32% by weight of R-32, and about 50 to about 95% by weight of CO2, for example, about 2 to about 15% by weight of R-1132a, about 2 to about 32% by weight of R-32, and about 55 to about 93% by weight of CO2. 2、 For example, the use according to embodiment 2, comprising about 64 to about 93% by weight of carbon dioxide, about 2 to about 25% by weight of difluoromethane and about 2 to about 14% by weight of R-1132a, for example, about 65 to about 93% by weight of carbon dioxide, about 2 to about 22% by weight of difluoromethane and about 2 to about 14% by weight of R-1132a. [Aspect 22] The use according to any one of embodiments 1 to 21, wherein the refrigerant composition has a global warming potential (GWP) of less than 150. [Aspect 23] The use according to any one of embodiments 1 to 22, wherein the heat pump system is also adapted to perform air conditioning. [Aspect 24] The use according to any one of embodiments 1 to 23, wherein the composition essentially consists of the indicated components. [Pattern 25] The refrigerant composition is less flammable than R-1132a alone, preferably the refrigerant composition is less flammable than R-1132a alone. a. Higher flammability limit, b. Higher ignition energy, and / or c. Lower flame propagation speed A use according to any one of embodiments 1 to 24, having the following characteristics. [Aspect 26] The use according to any one of embodiments 1 to 25, wherein the refrigerant composition is non-flammable, preferably the refrigerant composition is non-flammable at ambient temperature, or the composition is non-flammable at 60°C. [Aspect 27] The use according to any one of embodiments 1 to 26, wherein the heat pump system further comprises a lubricant, preferably a polyol ester (POE) or polyalkylene glycol (PAG) lubricant. [Aspect 28] The use according to any one of embodiments 1 to 27, wherein the refrigerant composition evaporates at a temperature below -30°C, and preferably condenses at a temperature above 40°C. [Aspect 29] The use according to any one of embodiments 1 to 28, wherein the refrigerant composition can operate in heat pump mode at an ambient temperature lower than about -15°C, preferably lower than -20°C. [Aspect 30] The use according to any one of embodiments 1 to 29, wherein the refrigerant composition has a temperature gradient in the evaporator or condenser of less than about 15K, preferably less than about 10K, for example less than about 5K. [Aspect 31] An electric vehicle comprising a heat pump system and a refrigerant composition as defined in any one of embodiments 1 to 30. [Aspect 32] A method for cooling an electric vehicle, comprising evaporating a refrigerant composition defined in any one of embodiments 1 to 30 near an object to be cooled. [Aspect 33] A method for heating in an electric vehicle, comprising condensing a refrigerant composition defined in any one of embodiments 1 to 30 near an object to be heated. [Brief explanation of the drawing]

[0096] [Figure 1] This shows a heat pump system. [Figure 2] This shows the cooling mode performance of a three-component blend of R-1132a / R-32 / R-1234yf (8 / 11 / 81%) compared to R-1234yf. [Figure 3] This shows the cooling mode performance of a three-component blend of R-1132a / R-32 / R-1234yf (8 / 11 / 81%) compared to R-1234yf.

Claims

1. A refrigerant composition comprising 1,1-difluoroethylene (R-1132a), difluoromethane (R-32), 1,1-difluoroethane (R-152a), and at least one tetrafluoropropene refrigerant compound selected from the group consisting of 2,3,3,3-tetrafluoropropene (R-1234yf) and 1,3,3,3-tetrafluoropropene (R-1234ze(E)).

2. A refrigerant composition comprising 1,1-difluoroethylene (R-1132a), at least one tetrafluoropropene refrigerant compound selected from the group consisting of 2,3,3,3-tetrafluoropropene (R-1234yf) and 1,3,3,3-tetrafluoropropene (R-1234ze(E)), and optionally difluoromethane (R-32).

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