Refrigerant compositions and use thereof

Abstract

To provide a refrigerant composition suitable for use as a refrigerant in liquid chiller systems, such as in liquid chiller systems which are incorporated into or are thermal management systems of vehicles, especially electric vehicles.SOLUTION: The invention provides the use as a refrigerant of a composition comprising 1,1-difluoroethylene in a liquid chiller system.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to refrigerant compositions, and more particularly to refrigerant compositions comprising 1,1-difluoroethylene (R-1132a) suitable for use as refrigerants in liquid chiller systems, such as liquid chiller systems incorporated into or which are thermal management systems of vehicles, particularly electric vehicles. [Background technology]

[0002] The listing or discussion of a prior-published document or any background art in this specification should not necessarily be taken as an acknowledgement that the document or background art is part of the state of the art or is common knowledge.

[0003] Unless otherwise specified, the term "electric vehicle" as used herein should be understood to refer to both purely electric vehicles as well as vehicles that use electricity as one of several means of propulsion, such as hybrid vehicles.

[0004] A simple vapor compression cycle used in air conditioning for internal combustion engine (ICE) vehicles traditionally involves warm air being cooled and dehumidified by flowing in cross-flow over an evaporative heat exchanger, where a refrigerant evaporates in the evaporator tubes. Similarly, heat is rejected to the exterior of the vehicle by flowing ambient air in cross-flow over the condenser tubes, where the refrigerant condenses. The temperature of the air flowing over the evaporator decreases, and the temperature of the air flowing over the condenser increases.

[0005] In this configuration, the evaporation temperature of the refrigerant must be lower than the evaporation temperature of the air for heat exchange to occur in the evaporator, and simultaneously, the evaporation temperature of the refrigerant must be higher than the evaporation temperature of the air for heat exchange to occur in the condenser. This is shown in Figure 1 for a single component refrigerant (or equivalently, an azeotropic or near-azeotropic refrigerant mixture). In any practical heat exchanger, as shown in Figures 1-3, there is a minimum practical temperature difference between the hot and cold fluids, referred to as the "approach temperature" or "approach."

[0006] Non-azeotropic refrigerants used in cross-flow configurations must also adhere to these constraints. However, in this case, the situation is further complicated by the presence of "temperature glide"—the phenomenon in which a non-azeotropic refrigerant's temperature increases as it evaporates and decreases as it condenses. The overall temperature change during evaporation or condensation is temperature glide. This means that in the extreme case of pure cross-flow, the dew point temperature of the refrigerant in the evaporator must be lower than the temperature of the air exiting the evaporator, and the bubble point of the refrigerant in the condenser must be higher than the air temperature. This situation is illustrated in Figure 2. Viewing Figures 1 and 2 together, it is clear that the combined effects of temperature glide and glide can result in average evaporation and condensation temperatures for a non-azeotropic refrigerant that are quite different from those for a fluid without glide. This has the effect of adversely affecting the refrigerant's performance compared to a fluid without glide.

[0007] In electric vehicles (whether pure battery electric vehicles (BEVs) or hybrid electric vehicles (HEVs)), the air conditioning system arrangements common to ICEs are increasingly being replaced or improved by the use of a liquid coolant loop to recover waste heat from components requiring cooling, particularly the drivetrain battery, but also other electronic components. Many configurations are possible, ranging from traditional air conditioning systems where the refrigerant can be fed to a "chiller" to remove heat from the coolant loop, to air conditioning systems that can operate in reverse as a heat pump to heat the passenger compartment, to full "secondary loop" configurations. In the latter, the refrigerant is not used directly to heat or cool the passenger air, but instead is used to transfer heat between reservoirs of hot and cold liquid. This allows the hot and cold liquids to be used to heat / cool the passenger compartment air.

[0008] While their configurations vary, a common feature of such thermal management systems, including secondary liquid heat transfer fluid circuits, is that the heat exchangers for transferring heat between the refrigerant and the hot and cold liquids in the chiller system are arranged so that the fluids flow countercurrently. The effect of this arrangement is shown in Figure 3 for a non-azeotropic refrigerant (Figure 1 is still valid for refrigerants without glide). It can be seen that glide does not adversely affect performance in this arrangement. Furthermore, the average evaporating temperature may increase (compared to the temperature of the fluid without glide) and the average condensing temperature may decrease (compared to the temperature of the fluid without glide). This means that glide allows the refrigerant cycle to operate over a lower temperature range than a fluid without glide, resulting in relative capacity and energy efficiency. DISCLOSURE OF THE INVENTION

[0009] It is an object of the present invention to address the above deficiencies.

[0010] According to a first aspect of the present invention there is provided the use of a composition comprising 1,1-difluoroethylene (R-1132a) as a refrigerant in a liquid chiller system.

[0011] The present inventors have unexpectedly discovered that compositions comprising 1,1-difluoroethylene (R-1132a), particularly compositions comprising R-1132a, difluoromethane (R-32), and 2,3,3,3-tetrafluoropropene (R-1234yf), can exploit their temperature glide to benefit the performance of liquid chiller systems, particularly liquid chiller systems comprising one or more countercurrent heat exchangers, when compared to R-1234yf or binary mixtures of R-32 and R-1234yf used in similar systems. Particularly useful applications for liquid chiller systems employing such compositions include thermal management systems for vehicles, particularly electric vehicles.

[0012] Liquid chiller systems using vapor compression cycles are known in the art. When used in such liquid chiller systems (particularly those with one or more countercurrent heat exchangers), the compositions disclosed herein exhibit superior cooling performance compared to R-1234yf or binary mixtures of R-1234yf and R-32 (e.g., R-454C).

[0013] Specifically, the performance of the compositions disclosed herein is significantly improved when the compositions are used in liquid chiller systems employing a counterflow heat exchanger configuration compared to a crossflow configuration, in stark contrast to the corresponding use of R-1234yf and binary compositions of R-1234yf and R-32 (e.g., R-454C), where such improvement is not observed (in the case of R-1234yf) or is insubstantial (in the case of R-454C).

[0014] In use according to the invention, the composition typically comprises a second component selected from difluoromethane (R-32), 2,3,3,3-tetrafluoropropene (R-1234yf), trans-1,3,3,3-tetrafluoropropene (R-1234ze(E)), 1,1-difluoroethane (R-152a), and mixtures thereof.

[0015] Advantageously, the composition comprises at least about 1 or about 1.5 wt. % R-1132a, such as at least 2 wt. %, for example at least about 3 or about 4 wt. %, for example at least about 5 wt. % R-1132a.

[0016] Advantageously, the composition comprises from about 1 to about 20 wt. % R-1132a, such as from about 2 to about 15 wt. %, for example, from about 3 to about 12 wt. %, optionally from about 4 to about 9 wt. %.

[0017] Typically, the second component is present in the composition in an amount of about 80 to about 99 wt %, for example, about 85 to about 98 wt %, for example, about 88 to about 97 wt %, optionally about 91 to about 96 wt %.

[0018] Advantageously, the second component is R-32 and / or R-1234yf, preferably the second component is R-32 and R-1234yf.

[0019] Advantageously, R-32 is present in the composition in an amount of from about 1 to about 30% by weight, such as from about 2 to about 25% by weight, for example, from about 3 to about 21% by weight, optionally from about 4 to about 19% by weight.

[0020] Typically, R-1234yf is present in the composition in an amount of from about 50 to about 98 wt%, e.g., from about 55 to about 97 wt%, e.g., from about 60 to about 96 wt%, optionally from about 65 to about 95 wt%, or from about 70 to about 94 or about 92 wt%.

[0021] Advantageously, the composition comprises about 1 to about 20 wt.% R-1132a, about 1 to about 30 wt.% R-32, and about 50 to about 98 wt.% R-1234yf; for example, the composition comprises about 2 to about 15 wt.% R-1132a, about 2 to about 25 wt.% R-32, and about 60 to about 96 wt.% R-1234yf; for example, the composition comprises about 3 to about 12 wt.% R-1132a, about 3 to about 21 wt.% R-32, and about 67 to about 94 wt.% R-1234yf; optionally, the composition comprises about 4 to about 9 wt.% R-1132a, about 4 to about 19 wt.% R-32, and about 72 to about 92 wt.% R-1234yf.

[0022] In the use of the present invention, the composition is advantageously a non-azeotropic composition.

[0023] The compositions disclosed in this invention are believed to exhibit an entirely unexpected combination of low flammability / non-flammability, low GWP, improved lubricant compatibility, and improved cooling performance properties in their claimed uses, liquid chiller systems and thermal management systems, some of which are described in more detail below.

[0024] The compositions of the present invention have an ozone depletion potential of zero.

[0025] Advantageously, the composition has a global warming potential (GWP) of less than about 200, such as less than about 300, such as less than about 150.

[0026] Flammability may be determined by ASHRAE Standard 34, which incorporates ASTM Standard E-681 (e.g., ASHRAE Standard 34:2019), the entire contents of which may be incorporated herein by reference.

[0027] In one embodiment, the composition has one or more of: (a) a higher lower flammability limit; (b) a higher ignition energy; (c) a higher autoignition temperature; or (d) a lower burn rate compared to R-1132a alone.

[0028] Preferably, the compositions of the present invention have reduced flammability compared to R-1132a in one or more of the following: lower flammability limit at 23°C, lower flammability limit at 60°C, width of flammable range at 23°C or 60°C, autoignition temperature (thermal decomposition temperature), minimum ignition energy in dry air, or burning rate. The flammability limit and burning 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.

[0029] Typically, the compositions are classified as "low flammable" (Class 2L) according to ASHRAE Standard 34:2019 or ISO Standard 817.

[0030] Advantageously, the formulated composition has a laminar burning velocity of less than about 10 cm / sec, such as less than about 7 cm / sec, for example less than about 5 cm / sec.

[0031] The compositions disclosed herein are typically compatible with all classes of lubricants currently in use with established HFC refrigerants. They may optionally be stabilized or compatibilized with mineral oils by the use of appropriate additives.

[0032] Typically, in use according to the present invention, the composition is combined with a lubricant.

[0033] The lubricant is advantageously selected from mineral oil, silicone oil, polyalkylbenzene (PAB), polyol ester (POE), polyalkylene glycol (PAG), polyalkylene glycol ester (PAG ester), polyvinyl ether (PVE), poly(alpha-olefin), and combinations thereof; preferably, the lubricant is selected from PAG, POE, and mixtures thereof.

[0034] Typically, the compositions have a higher coefficient of performance (COP) than that of R-1234yf or R-454C.

[0035] Advantageously, the composition has a higher volumetric cooling capacity than that of R-1234yf or R-454C.

[0036] In one embodiment, the composition can consist essentially of the listed components. The term "consisting essentially of" includes the meaning that the composition is substantially free of other components, particularly additional (hydro)(fluoro) compounds (e.g., (hydro)(fluoro)alkanes or (hydro)(fluoro)alkenes) known to be used in heat transfer compositions. The term "consisting of" is included in the meaning of "consisting essentially of."

[0037] In embodiments, the composition is substantially free of any components (other than those specified) that have heat transfer properties. For example, the composition of the present invention may be substantially free of any other hydrofluorocarbon compounds.

[0038] In one embodiment, the composition is substantially free of trifluoroiodomethane (CF3I).

[0039] "Substantially free" and "substantially free" include meaning that the composition contains no more than 0.5% by weight of the recited component, preferably no more than 0.4%, 0.3%, 0.2%, or 0.1%, based on the total weight of the composition.

[0040] As used herein, all percentage amounts referred to for compositions herein, including the claims, are by weight based on the total weight of the composition, unless otherwise specified.

[0041] The term "about" when used in connection with numerical values ​​of component amounts in weight percent includes ±0.5 weight percent, for example ±0.2 weight percent.

[0042] For the avoidance of doubt, it is understood that the upper and lower limits set forth for ranges of the amounts of ingredients in the compositions disclosed herein can be interchanged in any manner so long as the resulting range falls within the broadest scope of the invention.

[0043] The compositions can be prepared by simply mixing R-1132a with optional components such as a second component (eg, R-32 and R-1234yf) and / or a lubricant.

[0044] All chemicals described herein are commercially available, for example, fluorochemicals are available from Apollo Scientific (UK).

[0045] In the use of the present invention, the composition is used as a refrigerant in a liquid chiller system, some of the preferred features of which are discussed below.

[0046] Advantageously, the liquid chiller system comprises at least one countercurrent heat exchanger for exchanging heat between the refrigerant and the liquid.

[0047] Counterflow heat exchangers allow the refrigerant and liquid to flow countercurrently to one another as they pass through the counterflow heat exchanger, as opposed to crossflow heat exchangers in which the liquid and refrigerant flow approximately perpendicular to one another as they pass through the heat exchanger.

[0048] Typically, liquid chiller systems utilize a vapor compression refrigeration cycle.

[0049] Advantageously, the at least one countercurrent heat exchanger comprises at least one miniature plate countercurrent heat exchanger.

[0050] Advantageously, the liquid chiller system is a water chiller system or a water / glycol chiller system. Typically, the glycol can be ethylene glycol or propylene glycol (propane-1,2-diol). The liquid used in the liquid chiller system can also be a synthetic hydrocarbon fluid, a silicone-based fluid, or a fully or partially fluorinated fluid, such as a fluorinated ether or ketone.

[0051] Optionally, the liquid chiller system is a secondary loop liquid chiller system. In such a system, a refrigerant is used to transfer heat between a "cold" loop and a "hot" loop containing a liquid circulating in the liquid chiller system. It can also be used to provide direct cooling of the battery in parallel with providing conventional air conditioning cooling.

[0052] Preferably, the liquid chiller system is integrated into or is a thermal management system of a vehicle, preferably an electric vehicle. Conveniently, the vehicle thermal management system is a heat pump and / or an air conditioning system.

[0053] Advantageously, the liquid chiller system is adapted to heat and / or cool the battery and / or passenger compartment of a vehicle, preferably an electric vehicle. For example, the liquid chiller system may be adapted to cool and / or heat the passenger compartment of the vehicle, or may be adapted to cool the battery of the vehicle. The liquid chiller system may also be adapted to cool other sources of potentially useful waste heat, such as power electronics, instrument displays, or braking systems.

[0054] In a second aspect of the present invention, there is provided a liquid chiller system comprising at least one countercurrent heat exchanger for exchanging heat between a refrigerant composition and a liquid, the at least one countercurrent heat exchanger allowing the refrigerant composition and the liquid to flow countercurrently to one another as they pass through the countercurrent heat exchanger, the refrigerant composition being a composition comprising 1,1-difluoroethylene (R-1132a) and optionally a second component selected from difluoromethane (R-32), 2,3,3,3-tetrafluoropropene (R-1234yf), trans-1,3,3,3-tetrafluoropropene (R-1234ze(E)), and 1,1-difluoroethane (R-152a).

[0055] It will be understood that the preferred and optional features disclosed in relation to the first aspect of the invention apply equally to the second aspect of the invention.

[0056] Conveniently, the liquid chiller system is integrated into or is a vehicle thermal management system, preferably an electric vehicle thermal management system, which is typically a heat pump and / or air conditioning system.

[0057] Typically, the liquid chiller system is adapted to heat and / or cool the battery and / or passenger compartment of a vehicle, preferably an electric vehicle. For example, the liquid chiller system can be adapted to cool and / or heat the passenger compartment of the vehicle, or to cool the battery of the vehicle. The liquid chiller system can also be adapted to cool other sources of potentially useful waste heat, such as power electronics, instrument displays, or braking systems.

[0058] According to a third aspect of the present invention, there is provided a vehicle thermal management system comprising a liquid chiller system comprising at least one countercurrent heat exchanger for exchanging heat between a refrigerant composition and a liquid, the countercurrent heat exchanger allowing the refrigerant composition and the liquid to flow countercurrently to one another as they pass through the countercurrent heat exchanger, the refrigerant composition being a composition comprising 1,1-difluoroethylene (R-1132a) and optionally a second component selected from difluoromethane (R-32), 2,3,3,3-tetrafluoropropene (R-1234yf), trans-1,3,3,3-tetrafluoropropene (R-1234ze(E)), and 1,1-difluoroethane (R-152a), and preferably the vehicle is an electric vehicle.

[0059] It will be understood that the preferred and optional features disclosed in relation to the first and second aspects of the invention apply equally to the second aspect of the invention.

[0060] Conveniently, the liquid chiller system is adapted to heat and / or cool the battery and / or passenger compartment of the vehicle. For example, the liquid chiller system may be adapted to cool and / or heat the passenger compartment of the vehicle, or may be adapted to cool the battery of the vehicle. The liquid chiller system may also be adapted to cool other sources of potentially useful waste heat, such as power electronics, instrument displays, or braking systems.

[0061] Typically, the thermal management system further comprises at least one of a vapor injection system, an upper receiver and / or a lower accumulator for storing the refrigerant composition.

[0062] The invention is illustrated by reference to the following non-limiting figures. [Brief explanation of the drawings]

[0063] [Figure 1] The temperature change of a heat exchanger for a single refrigerant or an azeotropic refrigerant is shown. [Figure 2] 1 shows the temperature change in a cross-flow heat exchanger for a non-azeotropic refrigerant. [Figure 3] 1 shows the temperature change in a countercurrent heat exchanger for a non-azeotropic refrigerant.

[0064] The invention is illustrated by the following non-limiting examples. [Example]

[0065] A thermodynamic model of the R-1132a / R-32 / R-1234yf fluid system was constructed using the Span-Wagner equation of state implemented in NIST REFPROP9.1 software. A pure fluid model for R-1132a was derived by measuring its vapor pressure from the boiling point to the critical point, determining the critical point, measuring the densities of the compressed liquid and vapor, and measuring the enthalpy content and heat capacity of the fluid in the liquid and vapor states. The vapor-liquid equilibrium behavior of binary mixtures of R-1132a with R-32 and R-1234yf was then measured using a constant volume apparatus to measure the vapor pressures of a series of binary compositions over a temperature and pressure range from approximately -50 °C to +70 °C. These data were then regressed to provide binary interaction parameters suitable for use in modeling the performance of the ternary mixtures as refrigerants using standard cycle modeling techniques.

[0066] Two refrigeration / heat pump cycle models were then constructed in Microsoft Excel and interfaced with REFPROP software to provide thermodynamic property data for the mixtures. One model assumed a pure cross-flow heat exchanger geometry, with the minimum temperature approach limiting the refrigerant phase change temperature, as shown in Figure 1 (for fluids with zero glide) and Figure 2 (for fluids with glide). The other model assumed a counter-flow heat exchanger geometry, so the same minimum temperature approach was used but implemented to limit the phase change temperature, as shown in Figure 3. The performance of R-1234yf and a selected composition of R-1132a / R-32 / R-1234yf (6 wt% / 20 wt% / 74 wt%) were then simulated with both models, and the results were compared. As a comparative example, the performance of refrigerant R-454C (21.5 / 78.5% R-32 / R-1234yf) was also simulated. This refrigerant has a similar GWP to the ternary composition, but a smaller temperature glide.

[0067] The following cycle input conditions were assumed for the modeling: [Table 1]

[0068] The results of the modeling are shown in Tables 2 and 3 below. [Table 2] [Table 3]

[0069] The performance data shows that changes in heat exchanger geometry do not affect the performance of R1234yf, but do make a significant difference in the performance of the ternary compositions selected to illustrate the use of the present invention.

[0070] In cross-flow, selected blends exhibit a slightly reduced COP compared to R-1234yf, but in counter-flow, they exhibit significantly improved COP, reduced compressor displacement, reduced compression ratio, and reduced compressor discharge temperature.

[0071] Furthermore, performance data indicates that R-454C, when used in conjunction with a counterflow heat exchanger, offers some performance advantages compared to a crossflow heat exchanger, but not as much as the ternary composition.

[0072] The present invention includes the following aspects. [Aspect 1] 1. Use of a composition comprising 1,1-difluoroethylene (R-1132a) as a refrigerant in a liquid chiller system. [Aspect 2] 2. The use of embodiment 1, wherein the composition comprises a second component selected from difluoromethane (R-32), 2,3,3,3-tetrafluoropropene (R-1234yf), trans-1,3,3,3-tetrafluoropropene (R-1234ze(E)), 1,1-difluoroethane (R-152a), and mixtures thereof. [Aspect 3] 3. The use according to embodiment 1 or 2, wherein the composition comprises at least about 1 or about 1.5% by weight, such as at least 2% by weight, such as at least about 3 or about 4% by weight, for example at least about 5% by weight, of R-1132a. [Aspect 4] 4. The use according to any one of aspects 1 to 3, wherein the composition comprises from about 1 to about 20 wt. % R-1132a, e.g., from about 2 to about 15 wt. %, e.g., from about 3 to about 12 wt. %, optionally from about 4 to about 9 wt. % R-1132a. [Aspect 5] The use according to any one of aspects 2 to 4, wherein the composition comprises the second component in an amount of about 80 to about 99% by weight, e.g., about 85 to about 98% by weight, e.g., about 88 to about 97% by weight, optionally about 91 to about 96% by weight. [Aspect 6] 6. The use according to any one of aspects 2 to 5, wherein the second component comprises R-32 and / or R-1234yf, preferably the second component comprises R-32 and R-1234yf. [Aspect 7] 7. The use of any one of aspects 2 to 6, wherein the R-32 is present in the composition in an amount of from about 1 to about 30 wt %, e.g., from about 2 to about 25 wt %, e.g., from about 3 to about 21 wt %, optionally from about 4 to about 19 wt %. [Aspect 8] 8. The use of any one of aspects 2 to 7, wherein the composition comprises R-1234yf in an amount of about 50 to about 98 wt %, e.g., about 55 to about 97 wt %, e.g., about 60 to about 96 wt %, optionally about 65 to about 95 wt %, or about 70 to about 94 or about 92 wt %. [Aspect 9] The use of any one of Aspects 1 to 8, wherein the composition comprises about 1 to about 20 wt% R-1132a, about 1 to about 30 wt% R-32, and about 50 to about 98 wt% R-1234yf; e.g., about 2 to about 15 wt% R-1132a, about 2 to about 25 wt% R-32, and about 60 to about 96 wt% R-1234yf; e.g., about 3 to about 12 wt% R-1132a, about 3 to about 21 wt% R-32, and about 67 to about 94 wt% R-1234yf; optionally, the composition comprises about 4 to about 9 wt% R-1132a, about 4 to about 19 wt% R-32, and about 72 to about 92 wt% R-1234yf. [Aspect 10] Aspect 10. The use according to any one of aspects 1 to 9, wherein the composition is a non-azeotropic composition. [Aspect 11] 11. The use according to any one of aspects 1 to 10, wherein the composition has a global warming potential (GWP) of less than about 200, such as less than about 300, such as less than about 150. [Aspect 12] 12. The use of any one of aspects 1 to 11, wherein the composition is classified as "low flammable" (Class 2L) according to ASHRAE Standard 34:2019 or ISO Standard 817, and optionally the composition as formulated has a laminar burning velocity of less than about 10 cm / sec, e.g., less than about 7 cm / sec, e.g., less than about 5 cm / sec. [Aspect 13] 13. The use of any one of aspects 1 to 12, wherein the composition further comprises a lubricant selected from mineral oil, silicone oil, polyalkylbenzene (PAB), polyol ester (POE), polyalkylene glycol (PAG), polyalkylene glycol ester (PAG ester), polyvinyl ether (PVE), poly(alpha-olefin), and combinations thereof; preferably, the lubricant comprises PAG and / or POE or a mixture thereof. [Aspect 14] 14. The use of any one of aspects 1 to 13, wherein the composition has a coefficient of performance (COP) higher than that of R-1234yf or R-454C. [Aspect 15] 15. The use of any one of aspects 1 to 14, wherein the composition has a volumetric cooling capacity higher than that of R-1234yf or R-454C. [Aspect 16] 16. The use of any one of aspects 1 to 15, wherein the liquid chiller system comprises at least one countercurrent heat exchanger for exchanging heat between the refrigerant and the liquid, the countercurrent heat exchanger allowing the refrigerant and the liquid to flow countercurrently to one another as the refrigerant and the liquid pass through the countercurrent heat exchanger. [Aspect 17] 17. The use of any one of aspects 1-16, wherein the liquid chiller system utilizes a vapor compression refrigeration cycle. [Aspect 18] 18. The use according to any one of aspects 1 to 17, wherein the at least one countercurrent heat exchanger comprises at least one compact plate countercurrent heat exchanger. [Aspect 19] 19. The use of any one of aspects 1-18, wherein the liquid chiller system comprises a water chiller system or a water / glycol chiller system. [Aspect 20] Aspect 20. The use of any one of aspects 1-19, wherein the liquid chiller system comprises a secondary loop liquid chiller system. [Aspect 21] 21. The use of any one of aspects 1-20, wherein the liquid chiller system is integrated into or comprises a thermal management system (e.g., a heat pump and / or air conditioning system) of a vehicle, preferably an electric vehicle's thermal management system. [Aspect 22] 22. The use of any one of aspects 1-21, wherein the liquid chiller system is a liquid chiller system adapted to heat and / or cool a battery and / or a passenger compartment of a vehicle, preferably an electric vehicle, and optionally the liquid chiller system is adapted to cool power electronics, instrument displays, and / or a braking system of the vehicle. [Aspect 23] 1. A liquid chiller system comprising: at least one countercurrent heat exchanger for exchanging heat between a refrigerant composition and a liquid, the countercurrent heat exchanger allowing the refrigerant composition and the liquid to flow countercurrently to one another as they pass through the countercurrent heat exchanger; 1. A liquid chiller system, wherein the refrigerant composition comprises 1,1-difluoroethylene (R-1132a) and, optionally, a second component selected from difluoromethane (R-32), 2,3,3,3-tetrafluoropropene (R-1234yf), trans-1,3,3,3-tetrafluoropropene (R-1234ze(E)), and 1,1-difluoroethane (R-152a). [Aspect 24] 24. The liquid chiller system of embodiment 23, wherein the liquid chiller system is integrated into or comprises a thermal management system (e.g., a heat pump and / or an air conditioning system) of a vehicle, preferably a thermal management system of an electric vehicle. [Aspect 25] 25. The liquid chiller system of claim 23 or 24, wherein the liquid chiller system comprises a liquid chiller system adapted to heat and / or cool a battery and / or a passenger compartment of a vehicle, preferably an electric vehicle. [Aspect 26] 1. A thermal management system for a vehicle, comprising: a liquid chiller system comprising at least one countercurrent heat exchanger for exchanging heat between a refrigerant composition and a liquid, the countercurrent heat exchanger allowing the refrigerant composition and the liquid to flow countercurrently to one another as they pass through the countercurrent heat exchanger; 1. A thermal management system wherein the refrigerant composition comprises 1,1-difluoroethylene (R-1132a) and, optionally, a second component selected from difluoromethane (R-32), 2,3,3,3-tetrafluoropropene (R-1234yf), trans-1,3,3,3-tetrafluoropropene (R-1234ze(E)), 1,1-difluoroethane (R-152a), and preferably wherein the vehicle comprises an electric vehicle. [Aspect 27] 27. The thermal management system of embodiment 26, wherein the liquid chiller system comprises a liquid chiller system adapted to heat and / or cool a battery and / or a passenger compartment of a vehicle. [Aspect 28] 28. The thermal management system of embodiment 26 or 27, wherein the thermal management system further comprises at least one of a vapor injection system, an upper receiver, and / or a lower accumulator for storing the refrigerant composition.

Claims

[Claim 1] Use of a composition comprising 1,1-difluoroethylene (R-1132a) as a refrigerant in a liquid chiller system.

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