Method for controlling the temperature of a battery pack in a motor vehicle

Abstract

The present invention relates to a method for controlling the temperature of a battery pack in an electric or hybrid vehicle, using a system comprising a vapor compression circuit through which flows a first heat transfer composition containing 2,3,3,3-tetrafluoropropene and a secondary circuit through which flows a second heat transfer composition containing 1-chloro-3,3,3-trifluoropropene, wherein the ratio of the Z form to the E form of 1-chloro-3,3,3-trifluoropropene is less than or equal to 9, the method comprising: - heat exchange between the battery pack and the second heat transfer composition; - heat exchange between the second heat transfer composition and the first heat transfer composition. The invention also relates to a system for implementing the method.

Description

Technical Field

[0001] The present invention relates to a method for regulating the temperature of a battery of a motor vehicle and also to a device suitable for implementing the method. Background Art

[0002] The battery pack of an electric or hybrid vehicle provides maximum efficiency under the specific conditions of use and, in particular, within a very specific temperature range. Maximum efficiency means high available instantaneous power, high available total capacity, and improved battery pack life. Therefore, maximum battery pack efficiency enables not only better vehicle performance and autonomy, but also lower energy consumption per kilometer traveled.

[0003] Furthermore, during operation of an electric or hybrid vehicle, the temperature of the battery pack increases and must always be kept below 60°C, preferably below 40°C, in order to avoid premature aging of the battery pack, or indeed even destruction of the battery pack. At temperatures below 15°C, the charge of the battery pack decreases due to the increased internal resistance. Therefore, during operation of the vehicle, the temperature of the battery pack should be kept between approximately 15 and 40°C. Operation of the battery unit at temperatures below 0°C damages the battery cells and thus leads to a significant shortening of the battery cell life, so such conditions should be avoided.

[0004] In a motor vehicle, a heat engine comprises a circuit for the circulation of a heat exchange fluid, which is used to cool the engine and to heat the passenger compartment. To this end, the circuit comprises, in particular, a pump and a unit heater, through which circulates an air flow that extracts the heat stored in the heat exchange fluid in order to heat the passenger compartment.

[0005] Furthermore, the cooling system includes an evaporator, a compressor, a condenser, an expansion valve and a fluid that can change (liquid / gas) state (which is usually referred to as a refrigerant or heat transfer fluid). The refrigerant is compressed by a compressor that is directly driven by a belt and pulley by the vehicle's engine, forcing it to flow back to the condenser at high pressure and high temperature. The condenser uses forced ventilation to condense the gas that arrives in a gaseous state at high pressure and high temperature. The condenser liquefies the gas by lowering the temperature of the air passing through the condenser. The evaporator is a heat exchanger that removes heat from the air to be blown to the passenger compartment or battery pack of the vehicle. Depending on the temperature and pressure in the evaporator, the expansion valve makes it possible to adjust the flow rate of the gas entering the loop by changing the flow cross-section. As a result, the hot air from the outside of the vehicle or the battery pack comes into contact with the evaporator and is cooled.

[0006] A commonly used refrigerant in motor vehicle air conditioning is 1,1,1,2-tetrafluoroethane (HFC-134a).

[0007] However, a number of HFC fluids, including HFC-134a, can have a detrimental impact on the greenhouse effect, which is quantified by a numerical parameter called GWP (Global Warming Potential).

[0008] Another refrigerant that has since been used in heat transfer applications is 2,3,3,3-tetrafluoropropylene (HFO-1234yf). However, although HFO-1234yf is a low GWP fluid, it is considered flammable.

[0009] Document EP 3 499 634 relates to a battery thermal management system for a vehicle having at least one battery cell.

[0010] Document WO 2017 / 143018 relates to a refrigerant system for conditioning the air and / or products located in dwellings occupied by humans or other animals.

[0011] Document DE 202014010264 relates to a vehicle comprising at least a first compression refrigeration device designed to cool the interior of the vehicle and containing a circulating refrigerant, characterized in that the refrigerant is a substance from the group of fluoroketones and / or (hydro)fluoroolefins and / or (hydro)chlorofluoroolefins.

[0012] There is a need to provide a method for regulating the temperature of a battery pack of a motor vehicle that is efficient and safe while limiting or reducing the amount of flammable products in the vehicle or the proximity of these flammable products to the hottest components of the vehicle. Summary of the Invention

[0013] The present invention firstly relates to a method for regulating the temperature of a battery pack of an electric or hybrid vehicle by means of a system comprising a vapor compression circuit in which circulates a first heat-transfer composition containing 2,3,3,3-tetrafluoropropene and a secondary circuit in which circulates a second heat-transfer composition containing 1-chloro-3,3,3-trifluoropropene, the method comprising:

[0014] - heat exchange between the battery pack and the second heat transfer composition;

[0015] - heat exchange between the second heat transfer composition and the first heat transfer composition.

[0016] In some embodiments, the ratio of the Z form to the E form of 1-chloro-3,3,3-trifluoropropene is less than or equal to 5, preferably less than or equal to 1, preferably less than or equal to 0.5 and more preferably less than or equal to 0.1.

[0017] In some embodiments, the first heat transfer composition comprises one or more heat transfer compounds different from 2,3,3,3-tetrafluoropropene, preferably selected from difluoromethane, pentafluoroethane, 1,1,2,2-tetrafluoroethane, 1,1,1,2-tetrafluoroethane, 1,1-difluoroethane, fluoroethane, 1,1,1,2,3,3,3-heptafluoropropane, 1,1,1-trifluoropropane and mixtures thereof, and more preferably the compound is difluoromethane.

[0018] In some embodiments, 2,3,3,3-tetrafluoropropene is present in the first composition at about 78.5 weight percent and difluoromethane is present in the first composition at about 21.5 weight percent.

[0019] In some embodiments, the second heat transfer composition consists of 1-chloro-3,3,3-trifluoropropene.

[0020] In some embodiments, the second heat transfer composition is at a substantially uniform pressure in the secondary loop, preferably equal to the saturation pressure of the second composition.

[0021] In some embodiments, the battery pack is maintained at a temperature between a minimum temperature t1 and a maximum temperature t2.

[0022] In some embodiments, the minimum temperature t1 is greater than or equal to 0°C and the maximum temperature t2 is less than or equal to 60°C, more preferably the minimum temperature t1 is greater than or equal to 15°C and the maximum temperature t2 is less than or equal to 40°C, and more preferably the minimum temperature t1 is greater than or equal to 16°C and the maximum temperature t2 is less than or equal to 28°C.

[0023] In some embodiments, the method is carried out during charging of a battery pack of a vehicle, the battery pack of the vehicle preferably being fully charged within a period of less than or equal to 30 minutes and preferably less than or equal to 15 minutes from its complete discharge.

[0024] In some embodiments, the second heat transfer composition is in direct contact with the battery pack of the vehicle.

[0025] In some embodiments, the battery comprises at least one electrochemical cell comprising a negative electrode, a positive electrode, and an electrolyte, wherein the positive electrode comprises at least one electrochemically active material having the formula LiNi x Mn y Co z Oxides of O2 (wherein x+y+z=1, x>y and x>z) or having the formula LiNi x’ Co y’ Al z’Oxides of (wherein x'+y'+z'=1, x'>y' and x'>z').

[0026] The invention also relates to a device for regulating the temperature of a battery pack of an electric vehicle or a hybrid vehicle, comprising:

[0027] a vapor compression circuit in which circulates a first heat transfer composition comprising 2,3,3,3-tetrafluoropropene; and

[0028] a secondary circuit in which circulates a second heat-transfer composition comprising 1-chloro-3,3,3-trifluoropropene, wherein the ratio of the Z form to the E form of 1-chloro-3,3,3-trifluoropropene is less than or equal to 9;

[0029] The vapor compression circuit is coupled to the secondary circuit via an intermediate heat exchanger to enable heat exchange between the first heat transfer composition and the second heat transfer composition; and the apparatus comprises an additional heat exchanger configured for heat exchange between the battery pack and the second heat transfer composition.

[0030] In some embodiments, the secondary loop does not include a compressor.

[0031] In some embodiments, the circulation of the second heat transfer composition in the secondary loop is performed with the aid of a pump, or by gravity, or by capillary action.

[0032] In some embodiments, the device is additionally adapted for air conditioning the passenger compartment of the vehicle, and / or heating the passenger compartment of the vehicle, and / or cooling electronic compounds of the vehicle, and / or heating electronic compounds of the vehicle.

[0033] In some embodiments, the first heat transfer composition comprises one or more heat transfer compounds different from 2,3,3,3-tetrafluoropropene, preferably selected from difluoromethane, pentafluoroethane, 1,1,2,2-tetrafluoroethane, 1,1,1,2-tetrafluoroethane, 1,1-difluoroethane, fluoroethane, 1,1,1,2,3,3,3-heptafluoropropane, 1,1,1-trifluoropropane and mixtures thereof, and more preferably the compound is difluoromethane.

[0034] In some embodiments, 2,3,3,3-tetrafluoropropene is present in the first composition at about 78.5 weight percent and difluoromethane is present in the first composition at about 21.5 weight percent.

[0035] The present invention makes it possible to meet the needs described above. More particularly, it provides a method for regulating the temperature of a battery pack of a motor vehicle, which is effective and safe. It also makes it possible, if appropriate, to limit or reduce the amount of flammable products in the vehicle or their proximity to the hottest parts of the vehicle.

[0036] This is achieved by means of the coupled use of two heat transfer compositions, one of which contains HFO-1234yf and circulates in a vapor compression circuit, and the other contains HCFO-1233zd in which the ratio of Z form to E form is less than or equal to 9 and circulates in a secondary circuit, the heat transfer composition in the secondary circuit performing the required heat transfer with the battery pack of the vehicle. The heat transfer composition in the secondary circuit preferably does not contain flammable heat transfer compounds; or the composition is nonflammable. More particularly, given that HFO-1234yf is used as a heat transfer fluid in the vapor compression circuit, the use of a secondary circuit makes it possible to limit the extent of the vapor compression circuit and reduce the amount of HFO-1234yf used and / or prevent HFO-1234yf from coming into proximity with the hottest elements of the vehicle (in particular the battery pack of the vehicle), thus reducing the risk of leakage and fire. In addition, the use of a secondary circuit facilitates thermal management of the vehicle. More specifically, and taking electric vehicles as an example, there are numerous heat sources at different temperature levels (battery pack, electrical and electronic circuits, engine) and numerous requirements for heating and / or cooling (battery pack, passenger compartment). The use of a secondary circuit containing a heat transfer fluid facilitates the thermal management of these equipment items compared to other technologies.

[0037] Furthermore, it has been found that the combination of a first heat transfer composition comprising HFO-1234yf and a second heat transfer composition comprising HCFO-1233zd (Z / E ratio <9) enables in particular effective and safe regulation of the temperature of the battery pack of a vehicle.

[0038] The effectiveness of cooling or heating can be characterized by capacity and coefficient of performance. The temperatures and pressures observed in the circuit (especially the temperature at the compressor outlet, the pressure at the condenser and indeed even the pressure at the evaporator) are also factors to be taken into account for evaluating effectiveness and safety.

[0039] The dielectric properties of HCFO-1233zd (both gaseous and liquid) are particularly advantageous for use close to, and indeed even in contact with, batteries.

[0040] In some embodiments, the use of a secondary loop also allows for reduced energy consumption due to lower pumping power compared to the use of a single-phase heat exchange fluid.

[0041] In some embodiments, the use of a secondary loop comprising a second heat transfer composition allows for a lighter vehicle by avoiding the use of solid phase change materials for heat exchange.

[0042] In some embodiments, because the second heat transfer composition does not contain flammable heat transfer compounds, or is at least non-flammable, it can also act as a fire extinguishing agent in the event that the vehicle's battery pack overheats.

[0043] In some embodiments, the battery pack is immersed in the second conductive composition, and the second conductive composition is a dielectric. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 An embodiment of the device according to the invention is schematically represented. DETAILED DESCRIPTION

[0045] The invention will now be described in more detail in a non-limiting manner in the following description.

[0046] The present invention relates to a heat transfer method for regulating the temperature of a battery pack of a motor vehicle (i.e., for cooling and heating), which is performed with the aid of a heat transfer device comprising a first and a second heat transfer composition, each heat transfer composition comprising a heat transfer fluid comprising one or more heat transfer compounds.

[0047] The term "heat-transfer compound" is understood to mean a compound that is able to absorb heat (for example by evaporation) and to release heat (for example by condensation) in the application under consideration.

[0048] In the context of the present invention, "HFO-1234yf" refers to 2,3,3,3-tetrafluoropropene, "HCFO-1233zd" refers to 1-chloro-3,3,3-trifluoropropene, "HCFO-1224yd" refers to 1-chloro-2,3,3,3-tetrafluoropropene and "HFO-1336mzz" refers to 1,1,1,4,4,4-hexafluorobut-2-ene.

[0049] Vehicle battery pack

[0050] The motor vehicle is an electric vehicle or a hybrid vehicle. It comprises at least one electric motor and, if appropriate, a heat engine. It therefore comprises an electronic circuit and a traction battery (hereinafter more simply referred to as a battery).

[0051] The battery comprises at least one electrochemical cell and preferably a plurality of electrochemical cells. Each electrochemical cell comprises a negative electrode, a positive electrode and an electrolyte disposed between the negative electrode and the positive electrode.

[0052] Each electrochemical cell may also include a separator in which the electrolyte is impregnated.

[0053] Electrochemical cells can be assembled in series and / or parallel in a battery.

[0054] The term "negative electrode" is understood to mean an electrode that acts as an anode when the battery is conducting current (that is, when it is in the process of discharging) and acts as a cathode when the battery is in the process of charging. The negative electrode typically comprises an electrochemically active material, optionally an electronically conductive material, and optionally a binder.

[0055] The term "positive electrode" is understood to mean an electrode that acts as a cathode when the battery is conducting current (that is, when it is in the process of discharging) and that acts as an anode when the battery is in the process of charging. The positive electrode typically comprises an electrochemically active material, optionally an electronically conductive material, and optionally a binder.

[0056] The term "electrochemically active material" is understood to mean a material that is capable of reversibly inserting ions.

[0057] The term "electron-conducting material" is understood to mean a material that is able to conduct electrons.

[0058] The negative electrode of the electrochemical cell may comprise, in particular, as electrochemically active material, graphite, lithium, a lithium alloy, Li4Ti5O 12 Type lithium titanate or titanium oxide TiO2, silicon or lithium / silicon alloy, tin oxide, lithium intermetallic compound or a mixture thereof.

[0059] When the negative electrode contains lithium, it may be in the form of a film of metallic lithium or a film of an alloy containing lithium. Among the lithium-based alloys that can be used, there may be mentioned, for example, lithium-aluminum alloys, lithium-silicon alloys, lithium-tin alloys, Li-Zn, Li3Bi, Li3Cd, and Li3SB. Examples of negative electrodes may include an active lithium film produced by rolling a lithium strip between rollers.

[0060] The positive electrode contains an electrochemically active material of the oxide type. It is a lithium / nickel / manganese / cobalt composite oxide (LiNi x Mn y Co z O2, where x+y+z=1, abbreviated as NMC, where x>y and x>z), or lithium / nickel / cobalt / aluminum composite oxide with high nickel content (LiNi x' Co y' Al z' , where x'+y'+z'=1, abbreviated as NCA, where x'>y' and x'>z').

[0061] Specific examples of these oxides are NMC532 (LiNi0.5 Mn 0.3 Co 0.2 O2), NMC622(LiNi 0.6 Mn 0.2 Co 0.2 O2) and NMC811(LiNi 0.8 Mn 0.1 Co 0.1 O2).

[0062] Mixtures of these oxides may be used. If appropriate, the above oxide materials may be combined with other oxides such as manganese dioxide (MnO2), iron oxide, copper oxide, nickel oxide, lithium / manganese composite oxides (e.g., Li x Mn2O4 or Li x M n O2), lithium / nickel oxide compositions (e.g. Li x NiO2), lithium / cobalt oxide compositions (e.g. Li x CoO2), lithium / nickel / cobalt composite oxides (such as LiNi 1-y Co y O2), lithium and transition metal composite oxides, spinel structure lithium / manganese / nickel composite oxides (such as Li x Mn 2-y Ni y O4), vanadium oxides, NMC and NCA oxides without high nickel content and mixtures thereof.

[0063] Preferably, the NMC or NCA oxide having a high nickel content accounts for at least 50% by weight of the oxide material present as electrochemically active material in the positive electrode, preferably at least 75% by weight, more preferably at least 90% by weight and more preferably substantially all of the oxide material present as electrochemically active material in the positive electrode.

[0064] In addition to the electrochemically active material, the material of each electrode may also contain an electron-conducting material, such as a carbon source, including, for example, carbon black, Carbon, Shawinigan carbon, graphite, graphene, carbon nanotubes, carbon fibers (e.g., vapor-grown carbon fibers or VGCFs), non-powdered carbon obtained by carbonization of organic precursors, or a combination of two or more of these. Other additives may also be present in the positive electrode material, such as lithium salts or ceramic or glass-type inorganic particles, or other compatible active materials (e.g., sulfur).

[0065] The material of each electrode can also include adhesive.The limiting examples of adhesive include linear, branched and / or crosslinked polyether polymer adhesive (for example based on poly (ethylene oxide) (PEO) or poly (propylene oxide) (PPO) polymer, or based on the polymer of the mixture of the two (or EO / PO copolymer), and optionally including crosslinkable unit), water-soluble adhesive (such as SBR (styrene / butadiene rubber), NBR (acrylonitrile / butadiene rubber), HNBR (hydrogenated NBR), CHR (epichlorohydrin rubber), ACM (acrylate rubber)), or fluoropolymer adhesive (such as PVDF (polyvinylidene fluoride), PTFE (polytetrafluoroethylene)), and combinations thereof.Some adhesives (such as those soluble in water) also can include additives, such as CMC (carboxymethyl cellulose).

[0066] The separator can be a porous polymer film. By way of non-limiting example, the separator can be composed of a porous film of a polyolefin (e.g., an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, an ethylene / methacrylate copolymer, or a multilayer structure of the above polymers).

[0067] The electrolyte may be composed of one or more lithium salts dissolved in a solvent or a mixture of solvents together with one or more additives.

[0068] As non-limiting examples, the one or more lithium salts may be selected from LiPF6 (lithium hexafluorophosphate), LiFSI (lithium bis(fluorosulfonyl)imide), LiTDI (lithium 2-trifluoromethyl-4,5-dicyanoimidazole), LiPOF2, LiB(C2O4)2, LiF2B(C2O4)2, LiBF4, LiNO3 or LiClO4.

[0069] The solvent(s) may be selected from the following non-exhaustive list: ethers, esters, ketones, alcohols, nitriles and carbonates.

[0070] Among the ethers, there may be mentioned linear or cyclic ethers, for example, dimethoxyethane (DME), methyl ethers of oligoethylene glycols of 2 to 5 ethylene oxide units, dioxolane, dioxane, dibutyl ether, tetrahydrofuran and mixtures thereof.

[0071] Among the esters, there may be mentioned phosphoric acid esters or sulfite esters. There may be mentioned, for example, methyl formate, methyl acetate, methyl propionate, ethyl acetate, butyl acetate, gamma-butyrolactone or mixtures thereof.

[0072] Among the ketones, mention may especially be made of cyclohexanone.

[0073] Among the alcohols there may be mentioned, for example, ethanol or isopropanol.

[0074] Among the nitriles there may be mentioned, for example, acetonitrile, acetonenitrile, propionitrile, methoxypropionitrile, dimethylaminopropionitrile, butyronitrile, isobutyronitrile, valeronitrile, pivalonitrile, isovaleronitrile, glutaronitrile, methoxyglutaronitrile, 2-methylglutaronitrile, 3-methylglutaronitrile, adiponitrile, malononitrile and mixtures thereof.

[0075] Among the carbonates there may be mentioned, for example, cyclic carbonates such as ethylene carbonate (EC) (CAS: 96-49-1), propylene carbonate (PC) (CAS: 108-32-7), butylene carbonate (BC) (CAS: 4437-85-8), dimethyl carbonate (DMC) (CAS: 616-38-6), diethyl carbonate (DEC) (CAS: 105-58-8), ethyl methyl carbonate (EMC) (CAS: 623-53-0), diphenyl carbonate (CAS: 10 2-09-0), methyl phenyl carbonate (CAS: 13509-27-8), dipropyl carbonate (DPC) (CAS: 623-96-1), methylpropyl carbonate (MPC) (CAS: 1333-41-1), ethyl propyl carbonate (EPC), vinylene carbonate (VC) (CAS: 872-36-6), fluoroethylene carbonate (FEC) (CAS: 114435-02-8), trifluoropropylene carbonate (CAS: 167951-80-6) or a mixture thereof.

[0076] The additive(s) may be selected from fluoroethylene carbonate (FEC), vinylene carbonate, 4-vinyl-1,3-dioxolane-2-one, pyridazine, vinylpyridazine, quinoline, vinylquinoline, butadiene, sebaconitrile, alkyl disulfide, fluorotoluene, 1,4-dimethoxytetrafluorotoluene, tert-butylphenol, di(tert-butyl)phenol, tris(pentafluorophenyl)borane, oxime, aliphatic epoxide, halogenated biphenyl, methacrylic acid, allyl ethyl carbonate, vinyl acetate, divinyl adipate, propane sultone, acrylonitrile, 2-vinylpyridine, maleic anhydride, methyl cinnamate, phosphonate, vinyl-containing silane compound, and 2-cyanofuran.

[0077] Device for regulating the temperature of a battery pack of a vehicle

[0078] The present invention relates to a heat transfer method comprising regulating the temperature of a battery pack of a motor vehicle in a heat transfer device.

[0079] The method according to the invention is therefore a method for cooling a battery pack of a vehicle; or a method for heating such a battery pack; or a method for cooling and heating (cooling and heating being performed alternately over time as required).

[0080] The method according to the present invention is implemented by the apparatus described below.

[0081] The heat transfer apparatus comprises a vapor compression circuit containing a first heat transfer composition (or refrigeration circuit) and a secondary circuit containing a second heat transfer composition (or heat exchange circuit).

[0082] According to Figure 1 In one embodiment of the invention schematically shown in FIG, a vapor compression circuit 1 is coupled to a secondary circuit 2. The vapor compression circuit 1 comprises at least one first heat exchanger 3, an expansion valve 4, an intermediate heat exchanger 5 and a compressor 6. The first heat exchanger 3 is preferably of the air / refrigerant type and allows heat exchange with an energy source (e.g., ambient air). The secondary circuit 2 comprises at least one additional heat exchanger 7.

[0083] The term "energy source" is understood to mean a solid and / or liquid and / or gaseous object that can absorb or release thermal energy as required. Examples of energy sources include the vehicle's external air, the passenger compartment air, the battery pack, and electronic circuitry.

[0084] In cooling mode (cooling of the battery pack), heat is transferred from the battery pack to the additional heat exchanger 7. Optionally, this heat transfer causes evaporation of the second heat transfer composition circulating in the secondary circuit 2. Alternatively, the second heat transfer composition remains liquid during this heat transfer.

[0085] The second heat transfer composition is then fed into an intermediate heat exchanger 5, which may act as a condenser for the secondary loop 2. Alternatively, the second heat transfer composition remains liquid at the intermediate heat exchanger 5 during the heat transfer.

[0086] In the vapor compression circuit 1, the first heat transfer composition is compressed by a compressor 6 and passes through a first heat exchanger 3 acting as a condenser (that is, transferring heat energy to a source (e.g., the outside air)), then through an expansion valve 4, where it expands, and then through an intermediate heat exchanger 5 acting as an evaporator for the vapor compression circuit 1. Thus, in the intermediate heat exchanger 5, heat is transferred from the second heat transfer composition to the first heat transfer composition, optionally resulting in condensation of the second heat transfer composition and evaporation of the first heat transfer composition. The first heat transfer composition is then sent again to the compressor 6, while the second heat transfer composition is sent to an additional heat exchanger 7 and enables cooling of the battery pack.

[0087] According to certain embodiments, the device according to the present invention is also suitable for heating a battery pack, in particular when the external temperature is low (e.g., less than 10°C, or less than 5°C, or less than 0°C, or less than -5°C, or less than -10°C, or less than -15°C, or less than -20°C, or less than -25°C, or less than -30°C, or less than -35°C).

[0088] Therefore, the present invention also covers a method for heating a battery pack by means of the device. If desired, the heating of the battery pack can be alternated with the cooling of the battery pack over time.

[0089] In the case of heating the battery pack, heat is transferred from the additional heat exchanger 7 to the battery pack, which may cause condensation of the second heat transfer composition circulating in the secondary circuit 2. Alternatively, the second heat transfer composition remains liquid during this heat transfer.

[0090] The second heat transfer composition is then fed into the intermediate heat exchanger 5, which may act as an evaporator for the secondary loop 2. Alternatively, the second heat transfer composition remains liquid at the intermediate heat exchanger 5 during the heat transfer.

[0091] In the vapor compression circuit 1, the first heat transfer composition is expanded in the expansion valve 4 and passes through the first heat exchanger 3, which acts as an evaporator (that is, it absorbs heat energy from a source (for example, the outside air)), then passes through the compressor 6, where it is compressed, and then passes through the intermediate heat exchanger 5, which acts as a condenser for the vapor compression circuit 1. Thus, in the intermediate heat exchanger 5, heat is transferred from the first heat transfer composition to the second heat transfer composition, resulting in condensation of the first heat transfer composition and, optionally, evaporation of the second heat transfer composition. The first heat transfer composition is then sent again to the expansion valve 4, while the second heat transfer composition is sent to the additional heat exchanger 7 and makes it possible to heat the battery pack.

[0092] According to certain embodiments, the device according to the invention is suitable for performing one or more phases of cooling the battery pack, alternating with one or more phases of heating the battery pack.

[0093] According to certain embodiments, the device according to the invention is also suitable for cooling (air conditioning) the passenger compartment of a vehicle and / or the electronic components of the vehicle. There is then a heat exchanger dedicated to heat exchange with the air of the passenger compartment and / or a heat exchanger dedicated to heat exchange with the electronic components.

[0094] According to certain embodiments, the device according to the invention is also suitable for heating the passenger compartment of a vehicle and / or the electronic components of the vehicle. There is then a heat exchanger dedicated to heat exchange with the air of the passenger compartment and / or a heat exchanger dedicated to heat exchange with the electronic components.

[0095] In certain embodiments, the same heat exchanger may provide the functionality of the intermediate exchanger 5 described above, depending on the mode of operation.

[0096] In certain embodiments, the same heat exchanger may provide the function of the first heat exchanger 3, depending on the operating mode.

[0097] Additional exchangers may also be added to ensure different modes of operation. Assemblies of pipes and valves may be used to ensure changes in the operating mode of each exchanger.

[0098] In some embodiments, vapor compression circuit 1 is reversible and may additionally comprise means for reversing its operation.

[0099] The means for reversing the operation of the reversible vapor compression circuit 1 are means for reversing the operation of the vapor compression circuit 1 between a cooling mode setting and a heat pump mode setting.

[0100] The aforementioned reversing means may be means for changing the path of the first heat transfer composition in the reversible vapor compression circuit 1 or means for reversing the direction of circulation of the first heat transfer composition in said circuit 1 .

[0101] The reversing device may be a four-way valve, a switching valve, a stop (on / off) valve, an expansion valve or a combination thereof.

[0102] For example, during reversal of the operating mode of the vapor compression circuit 1 , the role of the heat exchanger can be changed: for example, the heat exchanger can act as a condenser in cooling mode or as an evaporator in heat pump mode, or vice versa.

[0103] Alternatively, the role of the heat exchanger can remain the same during reversal of the operating mode of the vapor compression circuit 1. Since the heat exchanger is very simply connected to other energy sources via valves, it can absorb or release thermal energy depending on its function in the vapor compression circuit 1.

[0104] In certain preferred embodiments, the first heat transfer composition can circulate in a single direction in the vapor compression circuit 1 .

[0105] In other embodiments, the first heat transfer composition can circulate in vapor compression circuit 1 in two directions (that is, a first direction and an opposite direction).

[0106] The reversible vapor compression circuit 1 may typically contain pipes, tubes, hoses, tanks, or other elements in which the first heat transfer composition circulates between various exchangers, expansion valves, other valves, and the like.

[0107] When the device is also used to heat a vehicle battery pack, the first heat exchanger 3 can act as an evaporator or an energy collector (condenser), depending on the operating mode (refrigeration pump or heating pump) of the vapor compression circuit 1. The same applies to the intermediate heat exchanger 5.

[0108] Any type of heat exchanger can be used in the vapor compression circuit 1 and in particular a parallel-flow heat exchanger or, preferably, a counter-flow heat exchanger.

[0109] According to a preferred embodiment, the present invention provides a countercurrent heat exchanger at the first heat exchanger 3 or at the intermediate heat exchanger 5. This is because the heat transfer composition described in this patent application is particularly effective in combination with a countercurrent heat exchanger. Preferably, both the first heat exchanger 3 and the intermediate heat exchanger 5 are countercurrent heat exchangers.

[0110] According to the present invention, the term "counterflow heat exchanger" is understood to mean a heat exchanger in which heat is exchanged between a first fluid and a second fluid, the first fluid at the exchanger inlet exchanging heat with the second fluid at the exchanger outlet and the first fluid at the exchanger outlet exchanging heat with the second fluid at the exchanger inlet.

[0111] For example, a countercurrent heat exchanger comprises a device in which the flow of the first fluid and the flow of the second fluid are in opposite or substantially opposite directions. Exchangers operating in a crosscurrent mode with a countercurrent tendency are also included in the countercurrent heat exchanger within the meaning of this patent application.

[0112] The compressor 6 can be hermetic, semi-hermetic, or open. Hermetic compressors contain a motor component and a compression component confined within a non-removable sealed housing. Semi-hermetic compressors contain a motor component and a compression component assembled directly against each other. The coupling between the motor component and the compression component can be disassembled to separate the two components. Open compressors contain separate motor components and compression components. They can be operated by belt drive or by direct coupling.

[0113] As compressors, in particular dynamic compressors or positive displacement compressors may be used.

[0114] Dynamic compressors include axial compressors and centrifugal compressors, which can have one or more stages. Small centrifugal compressors can also be used.

[0115] Positive displacement compressors include rotary compressors and reciprocating compressors.

[0116] Reciprocating compressors include diaphragm compressors and piston compressors.

[0117] Rotary compressors include screw compressors, vane compressors, scroll (or screw) compressors, liquid ring compressors and vane compressors. Screw compressors can preferably be twin-screw or single-screw.

[0118] In the installation used, the compressor 6 can be driven by an electric motor or by a gas turbine (fed, for example, by the exhaust gases of a vehicle) or by a transmission.

[0119] In the device used, the compressor 6 may comprise means for injecting vapor or liquid. Said injection consists in introducing the refrigerant in liquid or vapor state into the compressor at a level between the start and the end of compression.

[0120] The secondary circuit 2 comprises at least one additional heat exchanger 7 .

[0121] Each additional heat exchanger 7 can be a fluid / solid type exchanger, or a fluid / fluid type exchanger, or a fluid / air type exchanger (for heating or cooling air, for example the air of the passenger compartment). In these latter two cases, the additional heat exchanger(s) 7 can also be a parallel flow heat exchanger or, preferably, a counter-flow heat exchanger.

[0122] At least one additional heat exchanger 7 may be provided to cool the battery pack. The same additional heat exchanger 7 or other additional heat exchangers 7 may be provided to heat the vehicle's battery pack (although it is preferred that the same additional heat exchanger 7 is capable of both cooling and heating the battery pack) or to cool and / or heat the passenger compartment and / or electronic components.

[0123] In order to cool or heat the battery pack (and / or electronic components), the air blown toward the battery pack (and / or electronic components) can be cooled or heated; or the additional exchanger 7 of interest can be brought into direct contact with the battery pack (and / or electronic components) or incorporated into the battery pack (and / or electronic components).

[0124] In certain embodiments, the second heat transfer composition is in direct contact with the vehicle's battery pack. In other words, the vehicle's battery pack is immersed in the second heat transfer composition. In this case, the corresponding additional heat exchanger 7 is confined to the housing containing all or part of the battery pack, with the second heat transfer composition contained in the housing and in contact with the outer wall of the battery pack.

[0125] This allows the favorable dielectric and thermal properties of the heat transfer composition to be reconciled for better results. In this case, it is preferred that the second heat transfer composition has a boiling pressure of less than 2 bar at a temperature of 30°C. If the boiling pressure of the second heat transfer composition is not low enough, direct contact would require considerable effort in designing the battery pack housing to withstand the pressure. In this case, the pressure stress can be more easily managed by using an additional heat exchanger 7, for example in the form of a cooling plate.

[0126] In certain embodiments, the secondary loop 2 does not include a compressor. In other words, the secondary loop 2 is not a vapor compression loop.

[0127] In certain embodiments, the second heat transfer composition is at a substantially uniform pressure in the secondary loop, the pressure being equal to the saturation pressure of the second heat transfer composition at the temperature of the second heat transfer composition. Slight deviations are possible in the event of head loss. The temperature of the second heat transfer composition is preferably uniform in the secondary loop.

[0128] In certain embodiments, the second heat transfer composition is maintained at a constant temperature during the method.

[0129] The term "saturation pressure" is understood to mean the pressure at which the gaseous and liquid phases of the composition are in equilibrium in a closed system at a given temperature.

[0130] In certain embodiments, the secondary loop 2 may comprise one or more valves, in particular when it comprises several additional heat exchangers 7, in order to direct the second heat transfer composition to one or more specific additional heat exchangers 7; and / or in order to make it possible to change the direction of circulation of the second heat transfer composition in all or part of the secondary loop 2.

[0131] In certain preferred embodiments, the second heat transfer composition may circulate in a single direction through all or part of the secondary loop 2 .

[0132] In certain embodiments, the second heat transfer composition may circulate in all or part of the secondary loop 2 in both directions (that is, a first direction and a reverse direction).

[0133] In certain embodiments, the circulation of the second heat transfer composition in the secondary loop 2 from the intermediate heat exchanger 5 to the additional heat exchanger(s) 7, and / or from the additional heat exchanger(s) 7 to the intermediate heat exchanger 5, may be performed with the aid of a pump, or by gravity, or by capillary action.

[0134] In the device according to the invention, the vapor compression circuit 1 can be coupled to the secondary circuit 2 via an intermediate heat exchanger 5. Thus, both the first heat transfer composition and the second heat transfer composition can pass through the intermediate heat exchanger 5.

[0135] During cooling of the battery pack, the intermediate heat exchanger 5 may evaporate the first heat transfer composition (and possibly condense the second heat transfer composition), and an additional heat exchanger 7 is provided to transfer heat from the battery pack to the second heat transfer composition.

[0136] During heating of the battery pack, the intermediate heat exchanger 5 may condense the first heat transfer composition (and possibly evaporate the second heat transfer composition), and the additional heat exchanger 7 is arranged to transfer heat from the second heat transfer composition to the battery pack (possibly while condensing the second heat transfer composition).

[0137] In certain embodiments, the second heat transfer composition is liquid throughout the secondary circuit 2. The temperature of the second heat transfer composition changes when passing through the additional heat exchanger 7 and when passing through the intermediate heat exchanger 5. This is a particularly preferred option when the battery pack is immersed in the second heat transfer composition.

[0138] In the context of this patent application, each evaporation and each condensation may be total or partial.

[0139] Evaporation may thus consist in: starting from the liquid state and entering the vapor state; or from a two-phase liquid / vapor state to a vapor state; or from a liquid state to a two-phase liquid / vapor state; or from one two-phase liquid / vapor state to another two-phase liquid / vapor state.

[0140] Condensation may thus consist in: starting from the vapor state and entering the liquid state; or from the vapor state to a two-phase liquid / vapor state; or from a two-phase liquid / vapor state to a liquid state; or from one two-phase liquid / vapor state to another two-phase liquid / vapor state.

[0141] The evaporation and condensation can be carried out at a constant temperature or, in the case of a zeotropic mixture of heat transfer compounds, at a variable temperature.

[0142] In certain embodiments, in the intermediate heat exchanger 5, one composition (the first heat transfer composition or the second heat transfer composition) is at a lower temperature than the other composition; preferably, the temperature difference is less than 12° C., preferably less than 8° C. and more preferably less than 5° C. Assuming that the temperature of the composition is not constant in the intermediate heat exchanger 5, the reference adopted for estimating the above temperature difference is the median temperature between the inlet and outlet of the intermediate heat exchanger.

[0143] In certain embodiments, cooling and / or heating allows the temperature of the battery pack to be maintained within an optimal temperature range, particularly when the vehicle is running (engine on) and especially when the vehicle is moving.

[0144] In certain embodiments, the temperature of the vehicle's battery pack is thus maintained between a minimum temperature t1 and a maximum temperature t2 .

[0145] In certain embodiments, the minimum temperature t1 is greater than or equal to 0°C and the maximum temperature t2 is less than or equal to 60°C, preferably the minimum temperature t1 is greater than or equal to 15°C and the maximum temperature t2 is less than or equal to 40°C, and more preferably the minimum temperature t1 is greater than or equal to 16°C and the maximum temperature t2 is less than or equal to 28°C.

[0146] In certain embodiments, the external temperature during the period of maintaining the temperature of the battery pack between the minimum temperature t1 and the maximum temperature t2 is greater than or equal to 20°C, preferably greater than or equal to 30°C, more preferably greater than or equal to 35°C, and more preferably greater than or equal to 40°C.

[0147] The external temperature during which the temperature of the battery pack of the vehicle is maintained between the minimum temperature t1 and the maximum temperature t2 may in particular be -35 to -30°C; -30 to -25°C; -25 to -20°C; or -20 to -15°C; or -15 to -10°C; or -10 to -5°C; or -5 to 0°C; or 0 to 5°C; or 5 to 10°C; or 10 to 15°C; or 15 to 20°C; or 20 to 25°C; or 25 to 30°C; or 30 to 35°C; or 35 to 40°C; or 40 to 45°C; or 45 to 50°C.

[0148] The term “external temperature” is understood to mean the ambient temperature outside the vehicle before and during the period in which the temperature of the battery pack of the vehicle is maintained between a minimum temperature t1 and a maximum temperature t2 .

[0149] The term "temperature of the battery pack" is understood to mean substantially the temperature of the outer wall of one or more electrical energy storage elements.

[0150] The temperature of the battery pack can be measured by a temperature sensor. If there are several temperature sensors at the battery pack, the temperature of the battery pack can be regarded as the average value of the different temperatures measured.

[0151] In certain embodiments, the apparatus and methods of the present invention allow for cooling and / or heating (and preferably cooling) of a vehicle's battery pack and maintaining it within an optimal temperature range during charging of the battery pack (as described in detail above).

[0152] In particular, the charging of the battery pack can be rapid charging. Thus, during a period of less than or equal to 30 minutes, and preferably less than or equal to 15 minutes, for fully charging the battery pack (from the moment the battery pack is fully discharged), the method according to the invention makes it possible to maintain the temperature of the battery pack within an optimal temperature range. This is advantageous, considering that during rapid charging, the battery pack tends to heat up quickly and reach high temperatures that can affect its operation and performance quality.

[0153] In certain embodiments, the second heat transfer composition is maintained throughout the secondary loop 2 at a temperature between 10 and 40°C, preferably between 20 and 30°C.

[0154] Heat transfer composition

[0155] The present invention utilizes a first heat transfer composition and a second heat transfer composition, each heat transfer composition comprising a heat transfer fluid, optionally in combination with a lubricant and / or additives.The heat transfer fluid may comprise one or more heat transfer compounds.

[0156] The first heat transfer composition is present in and circulates in the vapor compression circuit.

[0157] The heat transfer fluid of the first heat transfer composition comprises HFO-1234yf.

[0158] In certain embodiments, the heat transfer fluid comprises at least 50 wt% HFO-1234yf, or at least 60 wt% HFO-1234yf, or at least 70 wt% HFO-1234yf, or at least 80 wt% HFO-1234yf, or at least 90 wt% HFO-1234yf, or at least 95 wt% HFO-1234yf.

[0159] In certain embodiments, the heat transfer fluid consists essentially of, or in fact even consists of, HFO-1234yf.

[0160] In other preferred embodiments, the heat transfer fluid further comprises one or more other heat transfer compounds, such as hydrofluorocarbons and / or hydrofluoroolefins and / or hydrocarbons and / or hydrochlorofluoroolefins and / or CO2.

[0161] Mention may be made, among the hydrofluorocarbons, of difluoromethane (HFC-32), pentafluoroethane (HFC-125), 1,1,2,2-tetrafluoroethane (HFC-134), 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1-difluoroethane (HFC-152a), fluoroethane (HFC-161), 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea), 1,1,1-trifluoropropane (HFC-263fb) and mixtures thereof.

[0162] Among the hydrofluoroolefins, mention may especially be made of: 1,3,3,3-tetrafluoropropene (HFO-1234ze), in the cis and / or trans form, and preferably in the trans form; and trifluoroethylene (HFO-1123).

[0163] Among the hydrochlorofluoroolefins, mention may especially be made of 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd), in the Z and / or E form, and preferably in the E form.

[0164] According to a preferred embodiment, the heat transfer fluid of the first heat transfer composition comprises HFO-1234yf and HFC-32. Preferably, the heat transfer fluid is a binary composition of HFO-1234yf and HFC-32 (that is, it consists of HFO-1234yf and HFC-32, or consists essentially of HFO-1234yf and HFC-32).

[0165] Thus, HFO-1234yf may be present in an amount of 60% to 90% by weight and HFC-32 may be present in an amount of 40% to 10% by weight, preferably HFO-1234yf may be present in an amount of 70% to 80% by weight and HFC-32 may be present in an amount of 20% to 30% by weight, and more preferably HFO-1234yf may be present in an amount of 75% to 80% by weight and HFC-32 may be present in an amount of 20% to 25% by weight. According to a preferred embodiment, HFO-1234yf is present in an amount of about 78.5% by weight and HFC-32 is present in an amount of about 21.5% by weight. The weight percentages are provided relative to the heat transfer fluid of the first heat transfer composition.

[0166] The additives that may be present in the first heat-transfer composition of the invention may in particular be chosen from nanoparticles, stabilizers, surfactants, tracers, fluorescent agents, odorants and solubilizers.

[0167] The total amount of additives does not exceed 5% by weight, in particular 4% by weight, more in particular 3% by weight and very in particular 2% by weight, indeed even 1% by weight, of the first heat-transfer composition.

[0168] In certain embodiments, HFO-1234yf contains impurities. When present, they may comprise less than 1%, preferably less than 0.5%, preferably less than 0.1%, preferably less than 0.05%, and preferably less than 0.01% by weight relative to HFO-1234yf.

[0169] The heat transfer fluid of the first heat transfer composition may optionally comprise HFO-1243zf (3,3,3-trifluoropropene) and / or 3,3,3-trifluoropropyne.

[0170] The content of HFO-1243zf in the heat transfer fluid may be less than or equal to 10,000 ppm, or 5,000 ppm, or 1,000 ppm, or 500 ppm, or 100 ppm, or 50 ppm.

[0171] For example, the HFO-1243zf content in the heat transfer fluid may be: 0 to 1 ppm, or 1 to 10 ppm, or 10 to 50 ppm, or 50 to 100 ppm, or 100 to 500 ppm, or 500 to 1000 ppm, or 1000 to 5000 ppm, or 5000 to 10000 ppm.

[0172] The content of 3,3,3-trifluoropropyne in the heat transfer fluid may be less than or equal to 10,000 ppm, or 5,000 ppm, or 1,000 ppm, or 500 ppm, or 100 ppm, or 50 ppm.

[0173] For example, the content of 3,3,3-trifluoropropyne in the heat transfer fluid may be: 0 to 1 ppm, or 1 to 10 ppm, or 10 to 50 ppm, or 50 to 100 ppm, or 100 to 500 ppm, or 500 to 1000 ppm, or 1000 to 5000 ppm, or 5000 to 10000 ppm.

[0174] The above ppm values are provided by weight.

[0175] One or more lubricants may be present in the first heat transfer composition. These lubricants may be selected from polyol esters (POE), polyalkylene glycols (PAG) or polyvinyl ethers (PVE).

[0176] The lubricant may comprise from 1% to 50%, preferably from 2% to 40% and more preferably from 5% to 30% (by weight) of the first heat transfer composition.

[0177] The heat transfer fluid of the second heat transfer composition comprises one or more heat transfer compounds having a boiling point of 0 to 40°C, preferably 5 to 35°C and more preferably 8 to 34°C.

[0178] The term "boiling point of a compound" is understood to mean the temperature at which the compound boils at a pressure of 1 bar.

[0179] In certain embodiments, the boiling point of the heat transfer fluid of the second heat transfer composition is from 0 to 40°C, preferably from 5 to 35°C and more preferably from 8 to 34°C.

[0180] In the case of a mixture of several compounds, the boiling point of the mixture corresponds to the mean value between the onset of boiling and the end of boiling at a pressure of 1 bar.

[0181] The heat transfer fluid of the second heat transfer composition comprises HFCO-1233zd.

[0182] In certain embodiments, the heat transfer fluid comprises at least 50% HCFO-1233zd, or at least 60% HCFO-1233zd, or at least 70% HCFO-1233zd, or at least 80% HCFO-1233zd, or at least 90% HCFO-1233zd, or at least 95% HCFO-1233zd, or at least 98% HCFO-1233zd, or at least 99% HCFO-1233zd, or at least 99.5% HCFO-1233zd, or at least 99.9% HCFO-1233zd, or at least 99.95% HCFO-1233zd, by weight.

[0183] In certain preferred embodiments, the heat transfer fluid consists essentially of, and in fact even consists of, HCFO-1233zd.

[0184] The heat transfer fluid of the second heat transfer composition comprises HCFO-1233zd having a molar ratio of less than or equal to 9 of the Z form to the E form of HCFO-1233zd.

[0185] Preferably, the ratio may be less than or equal to 5, preferably less than or equal to 1, preferably less than or equal to 0.5 and more preferably less than or equal to 0.1. For example, the ratio may be 0.01 to 0.1; or 0.1 to 0.5; or 0.5 to 1; or 1 to 2; or 2 to 3; or 3 to 4; or 4 to 5; or 5 to 6; or 6 to 7; or 7 to 8; or 8 to 9.

[0186] Preferably, HCFO-1233zd comprises greater than 90 mol% of the E form, preferably greater than 92 mol% of the E form, preferably greater than 94 mol% of the E form, preferably greater than 96 mol% of the E form, preferably greater than 98 mol% of the E form, and more preferably greater than 99 mol% of the E form. In certain preferred embodiments, it is entirely or substantially entirely in the E form.

[0187] It should be noted that even though it has been described above that the HCFO-1233zd included in the second heat transfer composition is predominantly in the E form, the opposite is also contemplated. In other words, the present invention (method and apparatus) described thus far constitutes another invention (method and apparatus), except that the HCFO-1233zd in the second heat transfer composition is predominantly in the Z form (wherein the E / Z molar ratio is less than or equal to 9; preferably less than or equal to 5, or less than or equal to 1, or less than or equal to 0.5, or less than or equal to 0.1; for example, the ratio may be from 0.01 to 0.1; or from 0.1 to 0.5; or from 0.5 to 1; or from 1 to 2; or from 2 to 3; or from 3 to 4; or from 4 to 5; or from 5 to 6; or from 6 to 7; or from 7 to 8; or from 8 to 9).

[0188] HCFO-1233zd may thus comprise greater than 90 mol% Z-form, preferably greater than 92 mol% Z-form, preferably greater than 94 mol% Z-form, preferably greater than 96 mol% Z-form, preferably greater than 98 mol% Z-form, and more preferably greater than 99 mol% Z-form. In certain preferred embodiments, it is entirely, or substantially entirely, Z-form.

[0189] In certain embodiments, the second heat transfer composition may further comprise one or more heat transfer compounds having a boiling point of 0 to 40°C, which may be selected from hydrochlorofluoroolefins, hydrofluoroolefins, and combinations thereof.

[0190] In certain embodiments, the hydrochlorofluoroolefin may be, for example, 1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd).

[0191] HCFO-1224yd may be in the E and / or Z form.

[0192] Preferably, HCFO-1224yd comprises greater than 50 mol% Z-form, preferably greater than 60 mol% Z-form, preferably greater than 70 mol% Z-form, preferably greater than 80 mol% Z-form, preferably greater than 85 mol% Z-form, preferably greater than 90 mol% Z-form, preferably greater than 95 mol% Z-form, preferably greater than 98 mol% Z-form and more preferably greater than 99 mol% Z-form. Preferably, it is entirely in the Z-form.

[0193] In certain embodiments, the hydrofluoroolefin may be the E and / or Z form of 1,1,1,4,4,4-hexafluorobut-2-ene (HFO-1336mzz).

[0194] HFO-1336mzz may thus comprise greater than 50 mol% of the Z form, preferably greater than 60 mol% of the Z form, preferably greater than 70 mol% of the Z form, preferably greater than 80 mol% of the Z form, preferably greater than 85 mol% of the Z form, preferably greater than 90 mol% of the Z form, preferably greater than 95 mol% of the Z form, preferably greater than 98 mol% of the Z form and more preferably greater than 99 mol% of the Z form. It may be entirely in the Z form.

[0195] Alternatively, HFO-1336mzz may contain greater than 50 mol% of the E form, preferably greater than 60 mol% of the E form, preferably greater than 70 mol% of the E form, preferably greater than 80 mol% of the E form, preferably greater than 85 mol% of the E form, preferably greater than 90 mol% of the E form, preferably greater than 95 mol% of the E form, preferably greater than 98 mol% of the E form, and more preferably greater than 99 mol% of the E form. It may be entirely in the E form.

[0196] In certain embodiments, the heat transfer compound used in the second heat transfer composition has a latent heat of vaporization at 20°C greater than 100 kJ / kg, preferably greater than 110 kJ / kg, more preferably greater than 120 kJ / kg, more preferably greater than 130 kJ / kg, more preferably greater than 140 kJ / kg, more preferably greater than 150 kJ / kg and more preferably greater than 160 kJ / kg.

[0197] For a temperature of 20° C., the latent heat values of heat transfer compounds that can be used as the heat transfer fluid in the second composition are shown in the table below. The highest latent heat is observed for HCFO-1233zd(E).

[0198] [Table 1]

[0199] Heat transfer compounds Temperature (℃) Pressure (bar) Latent heat of vaporization (kJ / kg) HCFO-1233zd(E) 20 1.07 194 HFO-1336mzz(Z) 20 0.6 171 HFO-1336mzz(E) 20 1.66 141 HCFO-1224yd(Z) 20 1.26 164

[0200] In certain embodiments, the heat transfer fluid of the second heat transfer composition comprises a single heat transfer compound, namely HCFO-1233zd.

[0201] In certain preferred embodiments, the heat transfer fluid of the second heat transfer composition may be a binary mixture of heat transfer compounds.

[0202] In certain embodiments, the heat transfer fluid of the second heat transfer composition may be a ternary mixture of heat transfer compounds.

[0203] The second heat transfer composition is present in and circulates in the secondary loop.

[0204] In certain embodiments, the second heat transfer composition undergoes neither compression nor expansion.

[0205] In certain embodiments, the second heat transfer composition comprises at least 50% heat transfer fluid, or at least 60% heat transfer fluid, or at least 70% heat transfer fluid, or at least 80% heat transfer fluid, or at least 90% heat transfer fluid, or at least 95% heat transfer fluid, by weight.

[0206] In certain embodiments, the heat transfer fluid of the second heat transfer composition consists essentially of, or in fact even consists of, a heat transfer compound.

[0207] The additives that may be present in the second heat transfer composition of the present invention are the same as those described above with respect to the first heat transfer composition, and the same concentration ranges apply.

[0208] Further, the second heat transfer composition may comprise a C3 to C6 olefin stabilizer, in particular butene or pentene.

[0209] Example 1 - Calculation Method of Properties of Heat Transfer Fluids in Various Settings Considered

[0210] The RK-Soave equation is used to calculate density, enthalpy, entropy, and liquid / vapor equilibrium data for mixtures. Using this equation requires knowledge of the properties of the pure substances used in the mixture of interest and the interaction coefficients for each binary mixture.

[0211] The available data for each pure substance are: boiling point, critical temperature and critical pressure, the pressure curve as a function of temperature from the boiling point up to the critical point, the density of the saturated liquid and saturated vapor as a function of temperature.

[0212] Thus, data on HFC-32 and HFO-1234yf are available under Refrop, a software developed by NIST for calculating the properties of refrigerants.

[0213] The RK-Soave equation uses binary interaction coefficients to represent the behavior of the products as a mixture. Liquid / vapor equilibrium data for HFC-32 / HFO-1234yf binary mixtures are available under Refprop.

[0214] Example 2 - Performance Quality in Cooling

[0215] In the following, the data of Example 1 are used to simulate the behavior of the conductive composition according to the invention in the case of cooling of a battery.

[0216] The system considered is Figure 1 system.

[0217] The system was operated with a superheat of 0°C and a subcooling of 5°C (primary loop).

[0218] The coefficient of performance (COP) is defined as the available power provided by a system relative to the power drawn or consumed by the system.

[0219] The system was operated with a refrigerant inlet temperature of 16°C at the evaporator and a refrigerant start condensing temperature of 50°C at the condenser.

[0220] The performance qualities of the compositions are provided in the table below and are expressed relative to the performance qualities of the HFC-134a / HCFO-1233zd pair.

[0221] [Table 2]

[0222] first heat transfer composition Second heat transfer composition Main GWP (AR5) Secondary GWP (AR5) COP CAP R134a R1233zd 1300 1 100％ 100％ R1234yf R1233zd 1 1 96％ 92％ R32 / R1234yf (21.5% / 78.5%) R1233zd 150 1 95％ 143％

[0223] Example 3 - Performance Quality During Heating

[0224] In the following, the data of Example 1 are used to simulate the behavior of the conductive composition according to the invention in the case of heating of a battery.

[0225] The system considered is Figure 1 system.

[0226] The system was operated with a superheat of 5°C and a subcooling of 0°C (primary loop).

[0227] The coefficient of performance (COP) is defined as the available power provided by a system relative to the power drawn or consumed by the system.

[0228] The system was operated with a refrigerant inlet temperature of -10°C at the evaporator and a refrigerant start condensing temperature of 26°C at the condenser.

[0229] The performance qualities of the compositions are provided in the table below and are expressed relative to the performance qualities of the HFC-134a / HCFO-1233zd pair.

[0230] [Table 3]

[0231] first heat transfer composition Second heat transfer composition Main GWP (AR5) Secondary GWP (AR5) COP CAP R134a R1233zd 1924 1 100％ 100％ R1234yf R1233zd 1 1 97％ 99％ R32 / R1234yf (21.5% / 78.5%) R1233zd 150 1 97％ 159％

Claims

1. A method for regulating the temperature of a battery pack of an electric vehicle or a hybrid vehicle by means of a system comprising a vapor compression circuit in which circulates a first heat transfer composition containing 2,3,3,3-tetrafluoropropene and a secondary circuit in which circulates a second heat transfer composition containing 1-chloro-3,3,3-trifluoropropene, wherein: The ratio of the Z form to the E form of 1-chloro-3,3,3-trifluoropropene is less than or equal to 9, the method comprising: - heat exchange between the battery pack and the second heat transfer composition; - heat exchange between the second heat transfer composition and the first heat transfer composition.

2. The method of claim 1, wherein the ratio of the Z form to the E form of 1-chloro-3,3,3-trifluoropropene is less than or equal to 5.

3. The method of claim 2, wherein the ratio of the Z form to the E form of 1-chloro-3,3,3-trifluoropropene is less than or equal to 1.

4. The method of claim 3, wherein the ratio of the Z form to the E form of 1-chloro-3,3,3-trifluoropropene is less than or equal to 0.

5.

5. The method of claim 4, wherein the ratio of the Z form to the E form of 1-chloro-3,3,3-trifluoropropene is less than or equal to 0.

1.

6. The method of any one of claims 1 to 5, wherein the first heat transfer composition comprises one or more heat transfer compounds other than 2,3,3,3-tetrafluoropropene.

7. The method of claim 6, wherein the one or more heat transfer compounds other than 2,3,3,3-tetrafluoropropene are selected from the group consisting of difluoromethane, pentafluoroethane, 1,1,2,2-tetrafluoroethane, 1,1,1,2-tetrafluoroethane, 1,1-difluoroethane, fluoroethane, 1,1,1,2,3,3,3-heptafluoropropane, 1,1,1-trifluoropropane and mixtures thereof.

8. The method of claim 7, wherein the one or more heat transfer compounds other than 2,3,3,3-tetrafluoropropene is difluoromethane.

9. The method of claim 6, wherein 2,3,3,3-tetrafluoropropene is present in the first composition in an amount of about 78.5 weight percent and difluoromethane is present in the first composition in an amount of about 21.5 weight percent.

10. The method of one of claims 1 to 5, wherein the second heat transfer composition consists of 1-chloro-3,3,3-trifluoropropene.

11. The method of one of claims 1 to 5, wherein the second heat transfer composition is at a substantially uniform pressure in the secondary circuit.

12. The method of claim 11, wherein the second heat transfer composition is at a substantially uniform pressure in the secondary loop, said pressure being equal to the saturation pressure of the second composition.

13. The method of one of claims 1 to 5, wherein the battery pack is maintained at a temperature between a minimum temperature t1 and a maximum temperature t2. 14 . The method of claim 13 , wherein the minimum temperature t1 is greater than or equal to 0° C. and the maximum temperature t2 is less than or equal to 60° C.

15. The method of claim 14, wherein the minimum temperature t1 is greater than or equal to 15°C and the maximum temperature t2 is less than or equal to 40°C. 16 . The method of claim 15 , wherein the minimum temperature t1 is greater than or equal to 16° C. and the maximum temperature t2 is less than or equal to 28° C.

17. The method of any one of claims 1 to 5, which is performed during charging of a battery pack of a vehicle.

18. The method of claim 17, implemented during charging of a battery pack of a vehicle, the battery pack of the vehicle being fully charged within a period of less than or equal to 30 minutes from its complete discharge.

19. The method of claim 18, performed during charging of a battery pack of a vehicle, the battery pack of the vehicle being fully charged within a period of less than or equal to 15 minutes from its complete discharge.

20. The method of one of claims 1 to 5, wherein the second heat transfer composition is in direct contact with a battery pack of a vehicle.

21. The method of claim 1 , wherein the battery comprises at least one electrochemical cell comprising a negative electrode, a positive electrode and an electrolyte, the positive electrode comprising as electrochemically active material at least one electrolyte having the formula LiNi x Mn y Co z Oxides of O2, wherein x+y+z=1, x>y and x>z, or having the formula LiNi x’ Co y 'Al z’ An oxide wherein x'+y'+z'=1, x'>y' and x'>z'.

22. An apparatus for regulating the temperature of a battery pack of an electric vehicle or a hybrid vehicle, comprising: a vapor compression circuit (1) in which circulates a first heat transfer composition comprising 2,3,3,3-tetrafluoropropene; and a secondary circuit (2) in which circulates a second heat-transfer composition comprising 1-chloro-3,3,3-trifluoropropene, wherein the ratio of the Z form to the E form of 1-chloro-3,3,3-trifluoropropene is less than or equal to 9; The vapor compression circuit (1) is coupled to the secondary circuit (2) via an intermediate heat exchanger (5) to enable heat exchange between the first heat transfer composition and the second heat transfer composition; and the apparatus comprises an additional heat exchanger (7) configured for heat exchange between the battery pack and the second heat transfer composition.

23. Apparatus as claimed in claim 22, wherein the secondary circuit (2) does not contain a compressor.

24. Apparatus according to any one of claims 22 or 23, wherein the circulation of the second heat transfer composition in the secondary circuit (2) is carried out with the aid of a pump, or by gravity, or by capillary action.

25. The device as claimed in one of claims 22 or 23, which is additionally adapted for air conditioning a passenger compartment of a vehicle and / or heating a passenger compartment of a vehicle and / or cooling electronic components of a vehicle and / or heating electronic components of a vehicle.

26. The apparatus of one of claims 22 or 23, wherein the first heat transfer composition comprises one or more heat transfer compounds other than 2,3,3,3-tetrafluoropropene.

27. The apparatus of claim 26, wherein the one or more heat transfer compounds other than 2,3,3,3-tetrafluoropropene are selected from the group consisting of difluoromethane, pentafluoroethane, 1,1,2,2-tetrafluoroethane, 1,1,1,2-tetrafluoroethane, 1,1-difluoroethane, fluoroethane, 1,1,1,2,3,3,3-heptafluoropropane, 1,1,1-trifluoropropane, and mixtures thereof.

28. The apparatus of claim 27, wherein the one or more heat transfer compounds other than 2,3,3,3-tetrafluoropropene is difluoromethane.

29. The apparatus of claim 26, wherein 2,3,3,3-tetrafluoropropene is present in the first composition in an amount of about 78.5 weight percent and difluoromethane is present in the first composition in an amount of about 21.5 weight percent.

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