Method for regulating the temperature of a motor vehicle battery

Abstract

The invention relates to a method for regulating the temperature of a battery in an electric or hybrid motor vehicle, using a system comprising a vapor compression circuit through which circulates a first heat transfer composition comprising 2,3,3,3-tetrafluoropropene and a secondary circuit through which circulates a second heat transfer composition comprising 1-chloro-3,3,3-trifluoropropene having a Z-to-E ratio less than or equal to 9. The method comprises: heat exchange between the battery and the second heat transfer composition; and heat exchange between the second heat transfer composition and the first heat transfer composition. The invention also relates to an installation adapted for implementing this method.

Description

Title of the invention: Method for regulating the temperature of a battery in a motor vehicle Scope of the invention

[0001] The present invention relates to a method for regulating the temperature of a battery in a motor vehicle, as well as an installation adapted to implement this method. Technical background

[0002] The batteries of electric or hybrid vehicles deliver maximum efficiency under specific operating conditions and, above all, within a very specific temperature range. Maximum efficiency means high instantaneous power availability, high total available capacity, and an increased battery lifespan. Thus, maximum battery efficiency not only allows for better vehicle performance and range but also lower energy consumption per kilometer.

[0003] Furthermore, during the operation of the electric or hybrid vehicle, the battery temperature increases and must always be maintained below 60°C, preferably below 40°C, to prevent premature aging or even destruction of the battery. At temperatures below 15°C, the battery charge decreases due to increased internal resistance. Therefore, during vehicle operation, the battery temperature should be maintained between approximately 15 and 40°C. Operating the battery unit below 0°C damages the battery cells and consequently leads to a significant reduction in the battery unit's lifespan, so such conditions must be avoided.

[0004] In motor vehicles, the internal combustion engine includes a circulation circuit for a heat transfer fluid which is used for engine cooling and also for heating the passenger compartment. For this purpose, the circuit includes, in particular, a pump and a heater in which an airflow circulates, recovering the heat stored by the heat transfer fluid in order to heat the passenger compartment.

[0005] Furthermore, a cooling system comprises an evaporator, a compressor, a condenser, an expansion valve, and a fluid capable of changing state (liquid / gas), commonly referred to as a refrigerant or heat transfer fluid. The compressor, driven directly by the vehicle's engine via a belt and pulley, compresses the refrigerant, expelling it under high pressure and at high temperature to the condenser. The condenser, through a valve Forced ventilation causes the gas, which arrives in a high-pressure, high-temperature gaseous state, to condense. The condenser liquefies the gas by lowering the temperature of the air passing through it. The evaporator is a heat exchanger that extracts heat from the air that will be blown into the passenger compartment or from the vehicle's battery. The expansion valve regulates the gas flow into the loop by changing its cross-sectional area based on the temperature and pressure at the evaporator. Thus, the hot air coming from outside or from the vehicle's battery is cooled by contact with the evaporator.

[0006] The refrigerant traditionally used in automotive air conditioning is 1,1,1,2-tetrafluoroethane (HFC-134a).

[0007] However, many HFC fluids, including HFC-134a, can contribute adversely to the greenhouse effect. This contribution is quantified by a numerical parameter, the GWP (Global Warming Potential).

[0008] Another refrigerant now used in heat transfer applications is 2,3,3,3-tetrafluoropropene (HFO-1234yf). However, even though HFO-1234yf is a low GWP fluid, it is considered a flammable fluid.

[0009] Document EP 3499634 relates to a battery thermal management system for a vehicle with at least one battery unit.

[0010] Document WO 2017 / 143018 relates to refrigeration systems for air conditioning and / or articles located in a dwelling occupied by humans or other animals.

[0011] Document DE 202014010264 relates to a vehicle comprising at least one first compression refrigeration device designed to cool an internal space of the vehicle and comprising a circulating refrigerant, characterized in that the refrigerant is a substance from the family of fluoroketones and / or (hydro)fluoroolefins and / or (hydro)fluorochlorolefins.

[0012] There is a need to provide effective and safe methods for regulating the temperature of a motor vehicle battery, while limiting or reducing the amount of flammable products in the vehicle or their proximity to the hottest parts of the vehicle. Summary of the invention

[0013] The invention relates firstly to a method for regulating the temperature of a battery in an electric or hybrid motor vehicle, by means of a system comprising a vapor compression circuit in which a first heat transfer composition comprising 2,3,3,3-tetrafluoropropene circulates and a secondary circuit in which a second heat transfer composition circulates comprising l-chloro-3,3,3-trifluoropropene having a ratio of the Z form to the E form less than or equal to 9, the process comprising:

[0014] • the heat exchange between the battery and the second heat transfer composition; • the exchange of heat between the second heat transfer composition and the first heat transfer composition.

[0015] In embodiments, the ratio of the Z form to the E form of l-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 even more preferably less than or equal to 0.1.

[0016] In embodiments, the first heat transfer composition comprises one or more heat transfer compounds other than 2,3,3,3-tetrafluoropropene, these compounds preferably being 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 preferably this compound being difluoromethane.

[0017] In embodiments, 2,3,3,3-tetrafluoropropene is present at a content of approximately 78.5% by weight in the first composition and difluoromethane is present at a content of approximately 21.5% by weight in the first composition.

[0018] In embodiments, the second heat transfer composition consists of l-chloro-3,3,3-trifluoropropene.

[0019] In embodiments, the second heat transfer composition is at an essentially uniform pressure in the secondary circuit, said pressure preferably being equal to the saturation pressure of the second composition.

[0020] In embodiments, the battery is maintained at a temperature between a minimum temperature ti and a maximum temperature t2.

[0021] In embodiments, the minimum temperature ti 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 ti is greater than or equal to 15°C and the maximum temperature t2 is less than or equal to 40°C, and preferably the minimum temperature ti is greater than or equal to 16°C and the maximum temperature t2 is less than or equal to 28°C.

[0022] In embodiments, the process is implemented during the charging of the vehicle battery, the vehicle battery preferably being fully charged in a period less than or equal to 30 min, and preferably less than or equal to 15 min from its total discharge.

[0023] In embodiments, the second heat transfer composition is in direct contact with the vehicle's battery.

[0024] In embodiments, the battery comprises at least one electrochemical cell having a negative electrode, a positive electrode and an electrolyte, the positive electrode comprising at least one oxide of formula LiNixMnyCozO2 with x+y+z=l, x>y and x>z, or LiNixCoyAlz- with x'+y'+z'=l, x'>y' and x'>z', as an electrochemically active material.

[0025] The invention also relates to an installation for regulating the temperature of a battery in an electric or hybrid motor vehicle, comprising:

[0026] • a vapor compression circuit in which a first heat transfer composition comprising 2,3,3,3-tetrafluoropropene circulates; and • a secondary circuit in which a second heat transfer composition comprising l-chloro-3,3,3-trifluoropropene circulates, having a ratio of the Z form to the E form less than or equal to 9;

[0027] the vapor compression circuit being coupled with the secondary circuit by an intermediate heat exchanger, so as to permit heat exchange between the first heat transfer composition and the second heat transfer composition; and the installation comprising an additional heat exchanger configured to exchange heat between the coil and the second heat transfer composition.

[0028] In some embodiments, the secondary circuit does not include a compressor.

[0029] In embodiments, the circulation of the second heat transfer composition in the secondary circuit is carried out by means of a pump, or by gravity, or by capillarity.

[0030] In embodiments, the installation is further adapted for air conditioning the vehicle's passenger compartment, and / or heating the vehicle's passenger compartment, and / or cooling electronic components of the vehicle, and / or heating electronic components of the vehicle.

[0031] In embodiments, the first heat transfer composition comprises one or more heat transfer compounds other than 2,3,3,3-tetrafluoropropene, these compounds preferably being 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 preferably this compound being difluoromethane.

[0032] In embodiments, 2,3,3,3-tetrafluoropropene is present at a content of approximately 78.5% by weight in the first composition and difluoromethane is present at a content of approximately 21.5% by weight in the first composition.

[0033] The present invention addresses the need expressed above. More specifically, it provides an efficient and safe method for regulating the temperature of a motor vehicle battery. It also allows, where appropriate, for limiting or reducing the quantity of flammable products in the vehicle or their proximity to the hottest parts of the vehicle.

[0034] This is accomplished through the combined use of two heat transfer compositions, one comprising HFO-1234yf circulating in a vapor compression circuit, and the other comprising HCFO-1233zd having a Z-form to E-form ratio less than or equal to 9 and circulating in a secondary circuit. The heat transfer composition in the secondary circuit performs the required heat transfers with the vehicle's battery. Preferably, the heat transfer composition in the secondary circuit does not contain any flammable heat transfer compound; or this composition is non-flammable.Specifically, since HFO-1234yf is used as a heat transfer fluid in the vapor compression circuit, using a secondary circuit allows for a smaller vapor compression circuit footprint and reduces the amount of HFO-1234yf used. It also prevents the HFO-1234yf from coming into close proximity to the hottest vehicle components, particularly the vehicle battery, thereby reducing the risk of leaks and fires. Furthermore, using a secondary circuit facilitates the vehicle's thermal management. In particular, electric vehicles, for example, have numerous heat sources (battery, electrical and electronic systems, motor) and various heating and / or cooling requirements (battery, passenger compartment) at different temperature levels.The use of a secondary circuit including a heat transfer fluid facilitates the thermal management of this equipment compared to other technologies.

[0035] Furthermore, it has been observed that the combination of a first heat transfer composition comprising HFO-1234yf with a second heat transfer composition comprising HCFO-1233zd (Z / E ratio<9) allows for particularly efficient and safe regulation of the vehicle battery temperature.

[0036] Cooling or heating efficiency can be characterized by capacity and coefficient of performance. Temperatures and pressures observed in the circuits (in particular the compressor outlet temperature, condenser pressure, and even evaporator pressure) are also factors to be considered when evaluating efficiency and safety.

[0037] The dielectric properties of HCFO-1233zd (gas and liquid) are particularly advantageous for use in close proximity to, or even in contact with, the battery.

[0038] In certain embodiments, the use of the secondary circuit also allows for a reduction in energy consumption thanks to a low pumping power, compared to the use of a single-phase heat transfer fluid.

[0039] In some embodiments, the use of the secondary circuit comprising the second heat transfer composition allows for a reduction in vehicle weight, by avoiding the use of solid phase change materials to carry out heat exchanges.

[0040] In some embodiments, the second heat transfer composition, not containing flammable heat transfer compounds, or at least being non-flammable, can also serve as an extinguishing agent in case of overheating of the vehicle battery.

[0041] In some embodiments, the battery pack is immersed in the second transfer composition, and the second transfer composition is dielectric. Brief description of the figures

[0042] Fig. 1 schematically represents an embodiment of an installation according to the invention. Detailed description

[0043] The invention is now described in more detail and in a non-limiting manner in the following description.

[0044] The invention relates to a heat transfer method for temperature control, namely for cooling and / or heating a motor vehicle battery, implemented by means of a heat transfer system. The system comprises a first and a second heat transfer composition, each heat transfer composition comprising a heat transfer fluid which includes one or more heat transfer compounds.

[0045] By "heat transfer compound" is meant a compound capable of absorbing heat (for example by evaporating) and releasing heat (for example by condensing), in the application under consideration.

[0046] In the context of the invention, "HFO-1234yf" refers to 2,3,3,3-tetrafluoropropene, "HCFO-1233zd" refers to l-chloro-3,3,3-trifluoropropene, "HCFO-1224yd" refers to l-chloro-2,3,3,3-tetrafluoropropene, and "HFO-1336mzz" refers to 1,1,1,4,4,4-hexafluorobut-2-ene. Vehicle battery

[0047] The motor vehicle is an electric or hybrid vehicle. It includes at least one electric motor, and optionally a combustion engine. It therefore includes an electronic circuit and a traction battery, referred to simply as the battery hereafter.

[0048] 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 interposed between the negative and positive electrodes.

[0049] Each electrochemical cell may also include a separator, in which the electrolyte is impregnated.

[0050] Electrochemical cells can be assembled in series and / or in parallel in the battery.

[0051] The term "negative electrode" refers to the electrode that acts as the anode when the battery is delivering current (i.e., when it is discharging) and as the cathode when the battery is charging. The negative electrode typically comprises an electrochemically active material, possibly an electronically conductive material, and possibly a binder.

[0052] The term "positive electrode" refers to the electrode that acts as the cathode when the battery is delivering current (i.e., when it is discharging) and as the anode when the battery is charging. The positive electrode typically comprises an electrochemically active material, possibly an electronically conductive material, and possibly a binder.

[0053] The term "electrochemically active material" means a material capable of reversibly inserting ions.

[0054] The term "electronic conductive material" means a material capable of conducting electrons.

[0055] The negative electrode of the electrochemical cell may include, in particular, as an electrochemically active material, graphite, lithium, a lithium alloy, a lithium titanate of the type Li4ThO|2 or titanium oxide TiO2, silicon or a lithium and silicon alloy, a tin oxide, an intermetallic lithium compound, or a mixture thereof.

[0056] When the negative electrode comprises lithium, the lithium may be in the form of a metallic lithium film or a lithium alloy. Examples of lithium-based alloys that may be used include lithium-aluminum alloys, lithium-silica alloys, lithium-tin alloys, Li-Zn, Li3Bi, Li3Cd, and Li3SB. An example of a negative electrode may include a live lithium film prepared by rolling a lithium foil between rollers.

[0057] The positive electrode comprises an electrochemically active oxide-type material. This is a high-nickel-content lithium-nickel-manganese-cobalt composite oxide (LiNixMnyCozO2 with x+y+z = 1, abbreviated NMC, with x>y and x>z), or a high-nickel-content lithium-nickel-cobalt-aluminium composite oxide (LiNixCoyAlZ' with x'+y'+z'=1, abbreviated NCA, with x'>y' and x'>z').

[0058] Particular examples of these oxides are NMC532 (LiNi,5MnO,3CoO,2O2), NMC622 (LiNi,6MnO,2CoO,2O2) and NMC811 (LiNiO,xMnO,|CoO,|C)2).

[0059] Mixtures of these oxides can be used. The oxide material described above can, where appropriate, be combined with another oxide such as, for example: manganese dioxide (MnO2), iron oxide, copper oxide, nickel oxide, lithium-manganese composite oxides (e.g., LixMn2O4 or LixMnO2), lithium-nickel composition oxides (e.g., LixNiO2), lithium-cobalt composition oxides (e.g., LixCoO2), lithium-nickel-cobalt composite oxides (e.g., LiNiCoO2), lithium and transition metal composite oxides, spinel-structured lithium-manganese-nickel composite oxides (e.g., LixMn2.yNiO4), vanadium oxides, NMC and NCA oxides that are not high in nickel, and mixtures thereof.

[0060] Preferably, the high nickel NMC or NCA oxide represents at least 50% by weight, preferably at least 75% by weight, preferably still at least 90% by weight, and preferably still essentially all of the oxide material present in the positive electrode as an electrochemically active material.

[0061] The material of each electrode may also include, in addition to the electrochemically active material, an electronically conductive material such as a carbon source, including, for example, carbon black, Ketjen® carbon, Shawinigan carbon, graphite, graphene, carbon nanotubes, carbon fibers (e.g., gas-formed carbon fibers or VGCF), non-powdered carbon obtained by carbonization of an organic precursor, or a combination of two or more of these. Other additives may also be present in the material of the positive electrode, such as lithium salts or inorganic particles of the ceramic or glass type, or other compatible active materials (e.g., sulfur).

[0062] The material of each electrode may also include a binder. Non-limiting examples of binders include linear, branched, and / or crosslinked polyether polymer binders (e.g., polymers based on poly(ethylene oxide) (PEO), poly(propylene oxide) (PPO), or a mixture of the two (or an EO / PO copolymer), and possibly including crosslinkable units), water-soluble binders (such as SBR (styrene-butadiene rubber), NBR (acrylonitrile-butadiene rubber), HNBR (hydrogenated NBR), CHR (epichlorohydrin rubber), ACM (acrylate rubber)), or fluoropolymer binders (such as PVDF (polyvinylidene fluoride), PTFE (polytetrafluoroethylene), and combinations thereof). Some binders, such as water-soluble ones, may also include an additive such as CMC. (carboxymethylcellulose).

[0063] The separator can be a porous polymer film. By way of non-limiting example, the separator may consist of a porous polyolefin film such as ethylene homopolymers, propylene homopolymers, ethylene / butene copolymers, ethylene / hexene copolymers, ethylene / methacrylate copolymers, or multilayer structures of the above polymers.

[0064] The electrolyte may consist of one or more lithium salts dissolved in a solvent or a mixture of solvents with one or more additives.

[0065] By way of non-limiting examples, the lithium salt or lithium salts may be selected from LiPF6 (lithium hexafluorophosphate), LiFSI (lithium bis(fluorosulfonyl)imidide), LiTDI (lithium 2-trifluoromethyl-4,5-dicyanoimidazolate), LiPOF2, LiB(C2O4)2, LiF2B(C2O4)2, LiBF4, LiNO3, LiC104.

[0066] The solvent(s) may be chosen from the following non-exhaustive list: ethers, esters, ketones, alcohols, nitriles and carbonates.

[0067] Among the ethers, one can cite linear or cyclic ethers, such as for example dimethoxyethane (DME), methyl ethers of oligoethylene glycols of 2 to 5 oxyethylene units, dioxolane, dioxane, dibutyl ether, tetrahydrofuran, and their mixtures.

[0068] Examples of esters include phosphoric acid esters and sulfite esters. Examples include methyl formate, methyl acetate, methyl propionate, ethyl acetate, butyl acetate, gamma butyrolactone, or mixtures thereof.

[0069] Among the ketones, cyclohexanone can be mentioned in particular.

[0070] Among alcohols, examples include ethyl alcohol, iso- propyl.

[0071] Examples of nitriles include acetonitrile, pyruvonitrile, propionitrile, methoxypropionitrile, dimethylaminopropionitrile, butyronitrile, isobutyronitrile, valeronitrile, pivalonitrile, isovaleronitrile, glutaronitrile, methoxyglutaronitrile, 2-methylglutaronitrile, 3-methylglutaronitrile, adiponitrile, malononitrile, and mixtures thereof.

[0072] Examples of carbonates include 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 102-09-0), methyl phenyl carbonate (CAS: 13509-27-8), dipropyl carbonate (DPC) (CAS: 623-96-1), and methyl carbonate. propyl (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 mixtures thereof.

[0073] The additive(s) may be selected from the group consisting of fluoroethylene carbonate (FEC), vinylene carbonate, 4-vinyl-1,3-dioxolan-2-one, pyridazine, vinyl pyridazine, quinoline, vinyl quinoline, butadiene, sebaconitrile, alkyl disulfides, fluorotoluene, 1,4-dimethoxytetrafluorotoluene, t-butylphenol, di-t-butylphenol, tris(pentafluorophenyl)borane, oximes, aliphatic epoxides, halogenated biphenyls, methacrylic acids, allyl ethyl carbonate, vinyl acetate, divinyl adipate, propanesultone, acrylonitrile, 2-vinylpyridine, maleic anhydride, cinnamate methyl, phosphonates, silane compounds containing vinyl, 2-cyanofuran.

[0074] Installation for regulating the temperature of a vehicle's battery

[0075] The invention relates to a heat transfer method, comprising regulating the temperature of the battery of a motor vehicle, in a heat transfer installation.

[0076] The method according to the invention is thus a method for cooling the battery of a vehicle; or a method for heating this battery; or a method for cooling and heating (cooling and heating alternating over time, depending on the needs).

[0077] The process according to the invention is implemented using the installation shown below.

[0078] The heat transfer installation includes a vapor compression circuit which contains a first heat transfer composition (or refrigeration circuit) and a secondary circuit containing a second heat transfer composition (or heat transfer circuit).

[0079] According to one embodiment of the invention, schematically represented by [Fig. 1], the vapor compression circuit 1 is coupled with the 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 such as ambient air. The secondary circuit 2 comprises at least one additional heat exchanger 7.

[0080] The term "energy source" refers to a solid and / or liquid and / or gaseous body that can absorb or release heat as required. Examples of energy sources include outside air, cabin air, the battery, and the vehicle's electronic system.

[0081] In refrigeration mode (battery cooling), heat is transferred from the battery to the additional heat exchanger 7. Optionally, this heat transfer causes the evaporation of the second heat transfer composition which circulates in the secondary circuit 2. Alternatively, the second heat transfer composition remains in a liquid state during this heat transfer.

[0082] The second heat transfer composition then proceeds to the intermediate heat exchanger 5, which can act as the condenser for the secondary circuit 2. Alternatively, the second heat transfer composition remains in a liquid state during heat transfer at the intermediate heat exchanger 5.

[0083] In the vapor compression circuit 1, the first heat transfer composition is compressed by the compressor 6, it passes through the first heat exchanger 3 acting as a condenser (i.e. transfers calories to a source such as the outside air), then the expansion valve 4 where it is expanded, then the 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 the condensation of the second heat transfer composition and the evaporation of the first heat transfer composition.The first heat transfer composition then returns to the compressor 6, while the second heat transfer composition goes to the additional heat exchanger 7, and allows the battery to be cooled.

[0084] According to certain embodiments, the installation according to the invention is also suitable for heating the battery, in particular when the outside temperature is low, for example below 10°C, or 5°C, or 0°C, or -5°C, or -10°C, or -15°C, or -20°C, or -25°C, or -30°C, or -35°C.

[0085] Thus, the invention also covers a method for heating the battery using the installation. The heating of the battery can alternate with the cooling of the battery over time, as required.

[0086] In the case of battery heating, heat is transferred to the battery from the additional heat exchanger 7 which may cause condensation of the second heat transfer composition which circulates in the secondary circuit 2. Alternatively, the second heat transfer composition remains in the liquid state during this heat transfer.

[0087] The second heat transfer composition then proceeds to the intermediate heat exchanger 5, which can act as an evaporator for the secondary circuit 2. Alternatively, the second heat transfer composition remains in a liquid state during heat transfer at the intermediate heat exchanger. termedial 5.

[0088] In the vapor compression circuit 1, the first heat transfer composition is expanded in the expansion valve 4, it passes through the first heat exchanger 3 acting as an evaporator (i.e. absorbs calories from a source such as the outside air), then the compressor 6 where it is compressed, then the intermediate heat exchanger 5 acting 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, causing the condensation of the first heat transfer composition and optionally the evaporation of the second heat transfer composition.The first heat transfer composition then returns to the expansion valve 4, while the second heat transfer composition goes to the additional heat exchanger 7, and allows the heating of the battery.

[0089] According to certain embodiments, the installation according to the invention is adapted to perform one or more battery cooling phases alternating with one or more battery heating phases.

[0090] According to certain embodiments, the installation according to the invention is also adapted for cooling (air conditioning) the vehicle passenger compartment and / or the vehicle's electronic components. A heat exchanger dedicated to heat exchange with the passenger compartment air and / or a heat exchanger dedicated to heat exchange with the electronic components is then present.

[0091] According to certain embodiments, the installation according to the invention is also adapted for heating the vehicle's passenger compartment and / or the vehicle's electronic components. A heat exchanger dedicated to heat exchange with the passenger compartment air and / or a heat exchanger dedicated to heat exchange with the electronic components is then present.

[0092] In certain embodiments, the same heat exchanger can perform the function of the intermediate exchanger 5 described above, depending on the operating mode.

[0093] In some embodiments, the same heat exchanger can perform the function of the first heat exchanger 3, depending on the operating mode.

[0094] Additional heat exchangers can also be added to support the different operating modes. A set of pipes and valves can be used to enable the change of operating mode for each heat exchanger.

[0095] In some embodiments, the vapor compression circuit 1 is reversible and may further include means for reversing its operation.

[0096] 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 configuration in refrigeration mode and a configuration in heat pump mode.

[0097] The aforementioned reversing means may be means for modifying the path of the first heat transfer composition in the reversible vapor compression circuit 1, or means for reversing the direction of flow of the first heat transfer composition in said circuit 1.

[0098] The aforementioned reversing means may be a four-way valve, a reversing valve, a shut-off (closing) valve, a pressure regulator, or combinations thereof.

[0099] For example, when reversing the operating mode of the vapor compression circuit 1, the role of a heat exchanger can be changed: for example, a heat exchanger can play the role of a condenser in a refrigeration mode or the role of an evaporator in a heat pump mode or vice versa.

[0100] Alternatively, when the operating mode of the vapor compression circuit 1 is reversed, the role of a heat exchanger can remain the same. The heat exchanger, simply connected to other energy sources via valves, can absorb or release heat depending on its function in the vapor compression circuit 1.

[0101] In some preferred embodiments, the first heat transfer composition can flow in the vapor compression circuit 1 in a one-way direction.

[0102] In other embodiments, the first heat transfer composition can circulate in the vapor compression circuit 1 in both directions, i.e. a first direction and an opposite direction.

[0103] The reversible vapor compression circuit 1 may typically contain pipes, hoses, flexible hoses, a tank or other components, through which the first heat transfer composition circulates between the various exchangers, expansion valves, valves...

[0104] When the installation is also used for heating the vehicle battery, depending on the operating mode of the vapor compression circuit 1, refrigeration or heat pump, the first heat exchanger 3 can act as an evaporator or energy recovery unit (condenser). The same applies to the intermediate heat exchanger 5.

[0105] It is possible to use any type of heat exchanger in the vapor compression circuit 1, and in particular co-current heat exchangers or, preferably, counter-current heat exchangers.

[0106] According to a preferred embodiment, the invention provides for a counter-current heat exchanger, either at the first heat exchanger 3, or at the heat exchanger Intermediate 5. Indeed, the heat transfer compositions described in this application are particularly efficient with counter-flow heat exchangers. Preferably, both the first heat exchanger 3 and the intermediate heat exchanger 5 are counter-flow heat exchangers.

[0107] According to the invention, by "counter-current heat exchanger" means a heat exchanger in which heat is exchanged between a first fluid and a second fluid, the first fluid at the inlet of the exchanger exchanging heat with the second fluid at the outlet of the exchanger, and the first fluid at the outlet of the exchanger exchanging heat with the second fluid at the inlet of the exchanger.

[0108] For example, counterflow heat exchangers include devices in which the flow of the first fluid and the flow of the second fluid are in opposite, or nearly opposite, directions. Exchangers operating in crossflow mode with a counterflow tendency are also included among counterflow heat exchangers within the meaning of this application.

[0109] The compressor 6 can be hermetic, semi-hermetic, or open. Hermetic compressors comprise a motor section and a compression section confined within a non-removable hermetic housing. Semi-hermetic compressors comprise a motor section and a compression section directly joined together. The coupling between the motor section and the compression section is accessible by disassembling the two sections. Open compressors comprise a motor section and a compression section that are separate. They can operate by belt drive or by direct coupling.

[0110] As a compressor, a dynamic compressor or a positive displacement compressor may be used in particular.

[0111] Dynamic compressors include axial compressors and centrifugal compressors, which may be single-stage or multi-stage. Mini centrifugal compressors may also be used.

[0112] Positive displacement compressors include rotary compressors and reciprocating compressors.

[0113] Reciprocating compressors include diaphragm compressors and piston compressors.

[0114] Rotary compressors include screw compressors, lobe compressors, scroll (or spiral) compressors, liquid ring compressors, and vane compressors. Screw compressors may preferably be twin-screw or single-screw.

[0115] In the installation which is used, the compressor 6 can be driven by an electric motor or by a gas turbine (for example powered by the exhaust gases of the vehicle) or by gear.

[0116] In the installation used, the compressor 6 may include a vapor or liquid injection device. Injection consists of introducing refrigerant in liquid or vapor form into the compressor at an intermediate level between the beginning and end of compression.

[0117] The secondary circuit 2 includes at least one additional heat exchanger 7.

[0118] Each additional heat exchanger 7 may be a fluid / solid type exchanger, a fluid / fluid type exchanger, or a fluid / air type exchanger (for heating or cooling air, for example, passenger compartment air). In the latter two cases, the additional heat exchanger(s) 7 may again be cocurrent heat exchangers or, preferably, countercurrent heat exchangers.

[0119] At least one additional heat exchanger 7 can be configured to cool the battery. The same additional heat exchanger 7 or other additional heat exchangers 7 can be configured to heat the battery (although it is preferred that the same additional heat exchanger 7 be able to both cool and heat the battery), or to cool and / or heat the passenger compartment and / or the vehicle's electronic components.

[0120] To cool or heat the battery (and / or the electronic components), it is possible to cool or heat air which is blown towards the battery (and / or the electronic components); or to put the additional heat exchanger 7 concerned directly in contact with the battery (and / or the electronic components), or to integrate it into the battery (and / or the electronic components).

[0121] In certain embodiments, the second heat transfer composition is in direct contact with the vehicle battery. In other words, the vehicle battery is immersed in the second heat transfer composition. In this case, the corresponding additional heat exchanger 7 is limited to a housing containing all or part of the battery, the second heat transfer composition being contained within the housing and in contact with the outer wall of the battery.

[0122] This makes it possible to reconcile the good dielectric and thermal properties of the heat transfer composition in order to obtain a better result. In this case, it is preferable for the second heat transfer composition to have 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 sufficiently low, direct contact requires considerable effort in the design of the battery housing to withstand the pressure. In this case, the pressure constraint is more easily managed by using an additional heat exchanger 7 in the form, for example, of cooling plates.

[0123] In some embodiments, the secondary circuit 2 does not include a compressor. In other words, the secondary circuit 2 is not a vapor compression circuit.

[0124] In some embodiments, the second heat transfer composition is at a substantially uniform pressure in the secondary circuit, said pressure being equal to the saturation pressure of the second heat transfer composition at the temperature of the second heat transfer composition. A small deviation is possible in the event of a pressure drop. The temperature of the second heat transfer composition is preferably uniform in the secondary circuit.

[0125] In some embodiments, the second heat transfer composition remains at a constant temperature during the process.

[0126] By "saturation pressure" is meant the pressure at which a gaseous phase of a composition is in equilibrium with a liquid phase at a given temperature in a closed system.

[0127] In some embodiments, the secondary circuit 2 may include one or more valves, particularly when it includes 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 allow the change of the direction of circulation of the second heat transfer composition in all or part of the secondary circuit 2.

[0128] In some preferred embodiments, the second heat transfer composition can circulate in all or part of the secondary circuit 2 in a one-way direction.

[0129] In some embodiments, the second heat transfer composition can circulate in all or part of the secondary circuit 2 in both directions, i.e. a first direction and an opposite direction.

[0130] In some embodiments, the circulation of the second heat transfer composition in the secondary circuit 2 of 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 can be carried out by means of a pump, or by gravity, or by capillarity.

[0131] In this installation according to the invention, the vapor compression circuit 1 can be coupled with the secondary circuit 2 by the intermediate heat exchanger 5. Thus, the intermediate heat exchanger 5 can be traversed by both the first heat transfer composition and the second heat transfer composition.

[0132] During battery cooling, the intermediate heat exchanger 5 can evaporate the first heat transfer composition (and optionally condense the second heat transfer composition), and the additional heat exchanger 7 is configured to transfer heat from the battery to the second heat transfer composition.

[0133] During battery heating, the intermediate heat exchanger 5 can condense the first heat transfer composition (and optionally evaporate the second heat transfer composition), and the additional heat exchanger 7 is configured to transfer heat from the second heat transfer composition to the battery (optionally by condensing the second heat transfer composition).

[0134] In some embodiments, the second heat transfer composition is in the liquid state throughout the secondary circuit 2. The temperature of the second heat transfer composition is modified as it passes through the additional heat exchanger 7 and through the intermediate heat exchanger 5. This is notably the preferred option when the battery is immersed in the second heat transfer composition.

[0135] Within the framework of this application, each evaporation and each condensation may be total or partial.

[0136] Evaporation can thus consist of going from the liquid state to the vapor state; or from the two-phase liquid / vapor state to the vapor state; or from the liquid state to the two-phase liquid / vapor state; or from one two-phase liquid / vapor state to another two-phase liquid / vapor state.

[0137] Condensation can thus consist of going from the vapor state to the liquid state; or from the vapor state to the liquid / vapor two-phase state; or from the liquid / vapor two-phase state to the liquid state; or from one liquid / vapor two-phase state to another liquid / vapor two-phase state.

[0138] Evaporation and condensation can take place at constant temperature, or at variable temperature in the case of non-azeotropic mixtures of heat transfer compounds.

[0139] 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; preferably, the temperature difference is less than 12°C, preferably less than 8°C, and even more preferably less than 5°C. Assuming that the temperature of one composition is not constant in the intermediate heat exchanger 5, the above-mentioned temperature difference is estimated using the median temperature between the inlet and outlet of the intermediate heat exchanger.

[0140] In certain embodiments, cooling and / or heating make it possible to maintain the battery temperature within an optimal temperature range, by particularly when the vehicle is in operation (engine running), and especially when the vehicle is moving.

[0141] In some embodiments, the temperature of the vehicle battery is thus maintained between a minimum temperature ti and a maximum temperature t2.

[0142] In some embodiments, the minimum temperature ti 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 ti is greater than or equal to 15 °C and the maximum temperature t2 is less than or equal to 40 °C, and preferably even more the minimum temperature ti is greater than or equal to 16 °C and the maximum temperature t2 is less than or equal to 28 °C.

[0143] In some embodiments, the outside temperature during the maintenance of the battery temperature between the minimum temperature ti and the maximum temperature t2 is greater than or equal to 20°C, preferably greater than or equal to 30°C, preferably even greater than or equal to 35°C, preferably even greater than or equal to 40°C.

[0144] The outside temperature during the period of maintenance of the vehicle battery temperature between the minimum temperature ti 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.

[0145] By "outside temperature" is meant the ambient temperature outside the vehicle before and during the maintenance of the vehicle battery temperature between the minimum temperature ti and the maximum temperature t2.

[0146] By "battery temperature" is generally meant the temperature of an outer wall of one or more of the electrical energy storage elements.

[0147] The battery temperature can be measured using a temperature sensor. If several temperature sensors are present on the battery, the battery temperature can be considered to be the average of the different measured temperatures.

[0148] In certain embodiments, the installation and method of the present invention make it possible to cool and / or heat (and preferably, to cool) the vehicle battery and to maintain it in an optimal temperature range (as detailed above) during battery charging.

[0149] In particular, the battery charging can be a fast charge. Thus, when fully charging the battery (from a point where the battery is completely discharged) for a period of 30 minutes or less, and preferably For a charging time of 15 minutes or less, the method according to the invention maintains the battery temperature within an optimal range. This is advantageous because during rapid charging, the battery tends to heat up quickly and reach high temperatures that can affect its operation and performance.

[0150] In some embodiments, the second heat transfer composition is maintained at a temperature between 10 and 40°C, preferably between 20 and 30°C, throughout the secondary circuit 2. Heat transfer compositions

[0151] The invention uses a first heat transfer composition and a second heat transfer composition, each heat transfer composition comprising a heat transfer fluid optionally associated with lubricants and / or additives. The heat transfer fluid may comprise one or more heat transfer compounds.

[0152] The first heat transfer composition is present and circulates in the vapor compression circuit.

[0153] The heat transfer fluid of the first heat transfer composition comprises HFO-1234yf.

[0154] In some embodiments, this heat transfer fluid comprises at least 50% HFO-1234yf, or at least 60% HFO-1234yf, or at least 70% HFO-1234yf, or at least 80% HFO-1234yf, or at least 90% HFO-1234yf, or at least 95% HFO-1234yf, by weight.

[0155] In some embodiments, this heat transfer fluid consists essentially of, or even consists of, HFO-1234yf.

[0156] In other preferred embodiments, this heat transfer fluid also comprises one or more other heat transfer compounds, such as hydrofluorocarbons and / or hydrofluoroolefins and / or hydrocarbons and / or hydro-chlorofluoroolefins and / or CO2.

[0157] Among the hydrofluorocarbons, mention may be made in particular 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 their mixtures.

[0158] Among the hydrofluoroolefins, we can mention in particular 1,3,3,3-tetrafluoropropene (HFO-1234ze), in cis and / or trans form, and preferably in trans form; and tri-fluoroethylene (HFO-1123).

[0159] Among the hydrochlorofluoroolefins, one may mention in particular l-chloro-3,3,3-trifluoropropene (HCFO-1233zd), in Z and / or E form, and preference in form E.

[0160] According to preferred embodiments, 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 (i.e., it consists, or essentially consists, of HFO-1234yf and HFC-32).

[0161] Thus, HFO-1234yf may have a content of 60 to 90 wt%, and HFC-32 may have a content of 40 to 10 wt%, preferably HFO-1234yf may have a content of 70 to 80 wt%, and HFC-32 may have a content of 20 to 30 wt%, and again preferably HFO-1234yf may have a content of 75 to 80 wt%, and HFC-32 may have a content of 20 to 25 wt%. According to preferred embodiments, HFO-1234yf is present at a content of approximately 78.5 wt% and HFC-32 is present at a content of approximately 21.5 wt%. The wt%s are given relative to the heat transfer fluid of the first heat transfer composition.

[0162] The additives that may be present in the first heat transfer composition of the invention may in particular be chosen from nanoparticles, stabilizers, surfactants, tracer agents, fluorescent agents, odorants and solubilizing agents.

[0163] The total quantity of additives does not exceed 5% by weight, in particular 4%, in particular 3% and especially 2% by weight or even 1% by weight of the first heat transfer composition.

[0164] In some embodiments, HFO-1234yf contains impurities. When present, they may represent 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) of HFO-1234yf.

[0165] The heat transfer fluid of the first heat transfer composition may optionally include HFO-1243zf (3,3,3-trifluoropropene) and / or 3,3,3-trifluoropropyne.

[0166] The content of HFO-1243zf in the heat transfer fluid may be less than or equal to 10000 ppm, or 5000 ppm, or 1000 ppm, or 500 ppm, or 100 ppm, or 50 ppm.

[0167] By way of example, the content of HFO-1243zf in the heat transfer fluid may be: from 0 to 1 ppm, or from 1 to 10 ppm, or from 10 to 50 ppm, or from 50 to 100 ppm, or from 100 to 500 ppm, or from 500 to 1000 ppm, or from 1000 to 5000 ppm, or from 5000 to 10000 ppm.

[0168] 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.

[0169] By way of example, the content of 3,3,3-trifluoropropyne in the heat transfer fluid may be: from 0 to 1 ppm, or from 1 to 10 ppm, or from 10 to 50 ppm, or from 50 to 100 ppm, or from 100 to 500 ppm, or from 500 to 1000 ppm, or from 1000 to 5000 ppm, or from 5000 to 10000 ppm.

[0170] The above ppm values ​​are given by weight.

[0171] 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).

[0172] Lubricants may represent from 1 to 50%, preferably from 2 to 40% and preferably still from 5 to 30% (by weight) of the first heat transfer composition.

[0173] 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 of 5 to 35°C and even more preferably of 8 to 34°C.

[0174] By "boiling point of a compound" is meant the temperature at which the compound boils under a pressure of 1 bar.

[0175] In some embodiments, the heat transfer fluid of the second heat transfer composition has a boiling point of 0 to 40°C, preferably of 5 to 35°C and even more preferably of 8 to 34°C.

[0176] In the case of a mixture of several compounds, the boiling point of the mixture corresponds to the average between the starting boiling point and the final boiling point at a pressure of 1 bar.

[0177] The heat transfer fluid of the second heat transfer composition comprises HCFO-1233zd.

[0178] In some embodiments, this heat transfer fluid comprises at least 50% of HCFO-1233zd, or at least 60% of HCFO-1233zd, or at least 70% of HCFO-1233zd, or at least 80% of HCFO-1233zd, or at least 90% of HCFO-1233zd, or at least 95% of HCFO-1233zd, or at least 98% of HCFO-1233zd, or at least 99% of HCFO-1233zd, or at least 99.5% of HCFO-1233zd, or at least 99.9% of HCFO-1233zd, or at least 99.95% of HCFO-1233zd, by weight.

[0179] In some preferred embodiments this heat transfer fluid consists essentially of, or even consists of, HCFO-1233zd.

[0180] The heat transfer fluid of the second heat transfer composition comprises HCFO-1233zd having a molar ratio of the Z form to the E form of HCFO-1233zd less than or equal to 9.

[0181] Preferably this 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 even more preferably less than or equal to 0.1. For example, this 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.

[0182] Preferably HCFO-1233zd comprises more than 90 mol% of form E, preferably more than 92 mol% of form E, preferably more than 94 mol% of form E, preferably more than 96 mol% of form E, preferably more than 98 mol% of form E, and even more preferably more than 99 mol% of form E. In some preferred embodiments, it is essentially entirely, or entirely, in form E.

[0183] It should be mentioned that although, in the foregoing, it is stated that the HCFO-1233zd included in the second heat transfer composition is predominantly in E form, it is also possible to consider the reverse situation. In other words, another invention (method and installation) consists of the invention (method and installation) described so far, except that HCFO-1233zd is in the predominant Z form in the second heat transfer composition (more particularly with an W / Z molar ratio 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, this 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).

[0184] Thus, HCFO-1233zd may comprise more than 90 mol% of the Z form, preferably more than 92 mol% of the Z form, preferably more than 94 mol% of the Z form, preferably more than 96 mol% of the Z form, preferably more than 98 mol% of the Z form, and even more preferably more than 99 mol% of the Z form. In some preferred embodiments, it is essentially entirely, or entirely, in the Z form.

[0185] In some embodiments, the second heat transfer composition may also include 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.

[0186] In some embodiments, the hydrochlorofluoroolefin can be, for example, l-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd).

[0187] HCFO-1224yd can be in E and / or Z form.

[0188] Preferably, HCFO-1224yd comprises more than 50 mol% of form Z, preferably more than 60 mol% of form Z, preferably more than 70 mol% of form Z, preferably more than 80 mol% of form Z, preferably more than 85 mol% of form Z, preferably more than 90 mol% of form Z, preferably more than 95 mol% of form Z, preferably more than 98 mol% of form Z and even more preferably more than 99 mol% of form Z. Preferably, it is entirely in form Z.

[0189] In some embodiments, the hydrofluoroolefin may be l,l,l,4,4,4-hexafluorobut-2-ene (HFO-1336mzz) in E and / or Z form.

[0190] HFO-1336mzz may thus comprise more than 50 mol% of form Z, preferably more than 60 mol% of form Z, preferably more than 70 mol% of form Z, preferably more than 80 mol% of form Z, preferably more than 85 mol% of form Z, preferably more than 90 mol% of form Z, preferably more than 95 mol% of form Z, preferably more than 98 mol% of form Z and even more preferably more than 99 mol% of form Z. It may be entirely in form Z.

[0191] Alternatively, HFO-1336mzz may comprise more than 50 mol% of form E, preferably more than 60 mol% of form E, preferably more than 70 mol% of form E, preferably more than 80 mol% of form E, preferably more than 85 mol% of form E, preferably more than 90 mol% of form E, preferably more than 95 mol% of form E, preferably more than 98 mol% of form E, and further preferably more than 99 mol% of form E. It may be entirely in form E.

[0192] In some embodiments, the heat transfer compounds used in the second heat transfer composition have a latent heat of vaporization at 20°C greater than 100 kJ / kg, preferably greater than 110 kJ / kg, even more preferably greater than 120 kJ / kg, even more preferably greater than 130 kJ / kg, even more preferably greater than 140 kJ / kg, even more preferably greater than 150 kJ / kg, and even more preferably greater than 160 kJ / kg.

[0193] The latent heat values ​​of the heat transfer compounds that can be used in the second composition as a heat transfer fluid are shown in the table below for a temperature of 20°C. The highest latent heat is observed for HCFO-1233zd(E).

[0194] [Tables 1] Heat Transfer Compound Temperature (°C) Pressure (bar) Latent Heat of Evaporation (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

[0195] In some embodiments, the heat transfer fluid of the second heat transfer composition comprises a single heat transfer compound, namely HCFO-1233zd.

[0196] In some preferred embodiments, the heat transfer fluid of the second heat transfer composition may be a binary mixture of heat transfer compounds.

[0197] In some embodiments, the heat transfer fluid of the second heat transfer composition may be a ternary mixture of heat transfer compounds.

[0198] The second heat transfer composition is present and circulates in the secondary circuit.

[0199] In some embodiments, the second heat transfer composition does not undergo compression or expansion.

[0200] In some 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.

[0201] In some embodiments, the heat transfer fluid of the second heat transfer composition consists essentially of, or even consists of, heat transfer compounds.

[0202] The additives that may be present in the second heat transfer composition of the invention are the same as those described above in connection with the first heat transfer composition, the same concentration ranges applying.

[0203] Furthermore, the second heat transfer composition may include a C3 and C6 alkene stabilizer, in particular a butene or a pentene.

[0204] Example 1 - Method for calculating the properties of heat transfer fluids in the different configurations considered

[0205] The RK-Soave equation is used for calculating the densities, enthalpies, entropies, and liquid-vapor equilibrium data of mixtures. The use of this equation requires knowledge of the properties of the pure substances used in the mixtures in question, as well as the interaction coefficients for each binary component.

[0206] The data available for each pure substance are: boiling point, critical temperature and critical pressure, pressure-temperature curve from boiling point to critical point, saturated liquid and saturated vapor densities as a function of temperature.

[0207] Data on HFC-32 and HFO-1234yf are available under Refrop (software developed by NIST for calculating the properties of refrigerants).

[0208] The RK-Soave equation uses binary interaction coefficients to represent the behavior of the products in a mixture. Liquid-vapor equilibrium data for the HFC-32 / HFO-1234yf binary are available under Refprop. Example 2 - Cooling performance

[0209] In the following, the data from Example 1 are used to simulate the behavior of the transfer compositions according to the invention in the case of battery cooling

[0210] The system considered is that of [Fig.1].

[0211] The system operates with 0°C of superheat and 5°C of subcooling (primary circuit).

[0212] The coefficient of performance (COP) is defined as the useful power supplied by the system divided by the power supplied or consumed by the system.

[0213] The system operates with a refrigerant inlet temperature at the evaporator of 16°C and a refrigerant condensation start temperature at the condenser of 50°C.

[0214] The performance of the compositions is given in the table below and expressed relative to the performance of the HFC-134a / HCFO-1233zd pair

[0215] [Tables2] First heat transfer composition Second heat transfer composition Primary 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% Example 3 - Heating performance

[0216] In the following, the data from Example 1 are used to simulate the behavior of the transfer compositions according to the invention in the case of battery heating.

[0217] The system considered is that of [Fig.1].

[0218] The system operates with 5°C of superheat and 0°C of subcooling (primary circuit).

[0219] The coefficient of performance (COP) is defined as the useful power supplied by the system divided by the power supplied or consumed by the system

[0220] The system operates with a refrigerant inlet temperature at the evaporator of -10°C and a refrigerant condensation start temperature at the condenser of 26°C.

[0221] The performance of the compositions is given in the table below and expressed in relation to the performance of the HFC-134a / HCFO-1233zd pair.

[0222] [Tables3] First heat transfer composition Second heat transfer composition Primary 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

Demands

1. A method for regulating the temperature of a battery in an electric or hybrid motor vehicle, by means of a system comprising a vapor compression circuit in which a first heat transfer composition comprising 2,3,3,3-tetrafluoropropene circulates and a secondary circuit in which a second heat transfer composition comprising one or more heat transfer compounds having a boiling point of 0 to 40°C circulates, the method comprising: • heat exchange between the battery and the second heat transfer composition; • heat exchange between the second heat transfer composition and the first heat transfer composition; • and the battery is maintained at a temperature between a minimum temperature t1 and a maximum temperature t2.

2. A method according to claim 1, wherein the second heat transfer composition comprises l-chloro-3,3,3-trifluoropropene having a ratio of the Z form to the E form less than or equal to 9.

3. A method according to claim 1, wherein the second heat transfer composition comprises l-chloro-2,3,3,3-tetrafluoropropene.

4. A method according to claim 1, wherein the second heat transfer composition comprises 1,1,1,4,4,4-hexafluorobut-2-ene.

5. A method according to any one of claims 1 to 4 wherein the first heat transfer composition comprises one or more heat transfer compounds other than 2,3,3,3-tetrafluoropropene, such compounds preferably being 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 preferably such compound being difluoromethane.

6. A process according to claim 5, wherein 2,3,3,3-tetrafluoropropene is present at a content of approximately 78.5% by weight in the first composition and difluoromethane is present at

7. a content of approximately 21.5% by weight in the first composition. Method according to any one of claims 1 to 4 wherein the second heat transfer composition is in direct contact with the vehicle battery.

Images