METHOD FOR CHARGING AN ELECTRIC ENERGY ACCUMULATOR OF A MOTOR VEHICLE, THE MOTOR VEHICLE, AND A CHARGING STATION

Abstract

A method for charging at least one electric energy accumulator of a motor vehicle, wherein electric energy from a charging station external to the motor vehicle is transferred via a detachable electrical connection to the energy accumulator, wherein a cooling fluid is taken from the charging station via a detachable cooling fluid connection to at least one cooling element of the motor vehicle, so that thermal energy from the energy accumulator is transferred via the cooling element to the cooling fluid and taken away by the cooling fluid, wherein the liquid cooling fluid is mixed with a gas before and/or during its transfer to the cooling element, so that a cooling fluid/gas mixture is formed, wherein at least a portion of the cooling fluid is evaporated into gas during the transfer of the thermal energy from the energy accumulator to the cooling fluid.

Claims

1. A method for charging at least one electric energy accumulator of a motor vehicle, comprising: transferring electric energy from a charging station external to the motor vehicle via a detachable electrical connection to the energy accumulator, wherein a cooling fluid is taken from the charging station via a detachable cooling fluid connection to at least one cooling element of the motor vehicle, so that thermal energy from the energy accumulator is transferred via the cooling element to the cooling fluid and taken away by the cooling fluid, wherein the liquid cooling fluid is mixed with a gas before and/or during its transfer to the cooling element, so that a cooling fluid/gas mixture is formed, wherein at least a portion of the cooling fluid is evaporated into gas during the transfer of the thermal energy from the energy accumulator to the cooling fluid.

2. The method according to claim 1, wherein water is used as the cooling fluid and/or ambient air is used as the gas.

3. The method according to claim 1, wherein the charging station comprises a cooling fluid reservoir and/or it is connected to a cooling fluid source, wherein the cooling fluid is taken by a cooling fluid delivery device from the cooling fluid reservoir or the cooling fluid source to the cooling element.

4. The method according to claim 1, wherein gas is supplied to the cooling fluid by a gas delivery device, the gas delivery device being a component of the motor vehicle or the charging station.

5. The method according to claim 1, wherein the cooling element is a cooling plate standing in thermal contact with the energy accumulator or a heat exchanger by which thermal energy is transferred from a coolant circulating in a cooling circuit for the cooling of the energy accumulator to the cooling fluid.

6. The method according to claim 1, wherein the cooling fluid/gas mixture is partially or entirely discharged into the surroundings after the transfer of the thermal energy.

7. The method according to claim 1, wherein the cooling fluid/gas mixture is partially or entirely taken to a phase separator of the motor vehicle or the charging station after the transfer of the thermal energy, wherein a liquid phase of the cooling fluid/gas mixture, consisting of the liquid cooling fluid, and a gaseous phase of the cooling fluid/gas mixture, consisting of the evaporated cooling fluid and the gas, are separated from each other.

8. The method according to claim 7, wherein the gaseous phase is discharged into the surroundings and/or the liquid phase is supplied to the liquid cooling fluid prior to the transfer of the thermal energy.

9. A motor vehicle, comprising: at least one electric energy accumulator, and an electric interface, especially a charging socket, to form a detachable electric connection, by which electric energy can be transferred from a charging station external to the motor vehicle to the energy accumulator, and a cooling fluid interface, especially a connection nozzle, to form a detachable cooling fluid connection, by which a cooling fluid can be taken from the charging station to at least one cooling element of the motor vehicle, so that thermal energy can be transferred from the energy accumulator via the cooling element to the cooling fluid and taken away by the cooling fluid, wherein the motor vehicle includes: a gas delivery device configured to bring the liquid cooling fluid together with the gas before and/or during the feeding to the cooling element; and/or a phase separator, to which the cooling fluid/gas mixture can be taken partially or entirely and which is configured to separate a liquid phase of the cooling fluid/gas mixture, consisting of the liquid cooling fluid, from a gaseous phase of the cooling fluid/gas mixture, consisting of the evaporated cooling fluid and the gas.

10. The motor vehicle according to claim 9, further comprising the gas delivery device, wherein the gas delivery device can draw in ambient air as the gas via an intake opening of the motor vehicle and then supply it to the liquid cooling fluid via an air duct, which leads from the intake opening to the cooling element and/or to a cooling fluid line leading to the cooling element, at the motor vehicle side.

11. The motor vehicle according to claim 9, having the phase separator, wherein the motor vehicle further comprises a liquid phase drain line, leading from the phase separator to the cooling element and/or to the cooling fluid line or a cooling fluid line leading to the cooling element, wherein the liquid phase can be supplied by the liquid phase drain line to the liquid cooling fluid at the motor vehicle side and prior to the transfer of the thermal energy, and/or the motor vehicle further comprises a return connection interface by which a detachable return connection can be formed, which connects the phase separator to the charging station, wherein the liquid phase can be taken by the return connection to the liquid cooling fluid at the charging station side and/or the motor vehicle further comprises a gas phase drain line, leading from the phase separator to a gas phase drain opening of the motor vehicle, wherein the gaseous phase can be discharged via the gas phase drain line into the surroundings.

12. The motor vehicle according to claim 9 wherein the electric interface is a charging socket, and the cooling fluid interface is a connection nozzle.

13. A charging station for charging at least one electric energy accumulator of a motor vehicle, comprising: an electric interface, in particular a charging cable having a plug, in order to form a detachable electrical connection, by which electric energy can be transferred from the charging station external to the motor vehicle to the energy accumulator, and a cooling fluid interface, in particular a hose having a connector plug, in order to form a detachable cooling fluid connection, by which a cooling fluid can be taken from the charging station to at least one cooling element of the motor vehicle, so that thermal energy can be transferred from the energy accumulator via the cooling element to the cooling fluid and taken away by the cooling fluid, wherein the charging station includes: a gas delivery device, by which the liquid cooling fluid can be brought together with the gas before and/or during the feeding to the cooling element; and/or a phase separator, to which the cooling fluid/gas mixture can be taken partially or entirely and by which a liquid phase of the cooling fluid/gas mixture, consisting of the liquid cooling fluid, and a gaseous phase of the cooling fluid/gas mixture, consisting of the evaporated cooling fluid and the gas, can be separated from each other.

14. The charging station according to claim 13, comprising the gas delivery device, wherein the gas delivery device can draw in ambient air as the gas via an intake opening of the motor vehicle, wherein the gas can be supplied to the liquid cooling fluid via an air duct, which connects the intake opening to the cooling fluid line leading to the cooling fluid interface at the charging station side; and/or the charging station further comprises a gas connection interface, by which a detachable gas connection can be formed, which connects the intake opening to the cooling element and/or to a cooling fluid line of the motor vehicle leading to the cooling element, wherein the gas can be supplied by the gas connection to the liquid cooling fluid at the motor vehicle side.

15. The charging station according to claim 13, having the phase separator, wherein the charging station further comprises a liquid phase drain line, leading from the phase separator to a cooling fluid reservoir and/or to the or to a cooling fluid line leading to the cooling fluid interface, wherein the liquid phase can be supplied by the liquid phase drain line to the liquid cooling fluid at the charging station side and prior to the transfer of the thermal energy; and/or the charging station further comprises a gas phase drain line, which leads from the phase separator to a gas phase drain opening of the charging station, wherein the gaseous phase can be discharged by the gas phase drain line into the surroundings.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0039] Further benefits and details will emerge from the embodiments described in the following, as well as the figures.

[0040] FIG. 1 shows an arrangement comprising a motor vehicle and a first embodiment of a charging station to explain a first embodiment of a method.

[0041] FIG. 2 shows an arrangement comprising a first embodiment of a motor vehicle and a charging station to explain a second embodiment of a method.

[0042] FIG. 3 shows an arrangement comprising a motor vehicle and a second embodiment of a charging station to explain a third embodiment of a method.

[0043] FIG. 4 shows an arrangement comprising a second embodiment of a motor vehicle and the first embodiment of the charging station to explain a fourth embodiment of a method.

[0044] FIG. 5 shows an arrangement comprising a third embodiment of a motor vehicle and a charging station to explain a fifth embodiment of a method.

[0045] FIG. 6 shows an arrangement comprising a motor vehicle and a third embodiment of a charging station to explain a sixth embodiment of a method.

DETAILED DESCRIPTION

[0046] The highly schematic FIGS. 1 to 6 each show an arrangement of a motor vehicle 1 and a charging station 2 in the context of several embodiments. What is said about the individual figures holds equally for the other respective figures, unless otherwise explicitly stated.

[0047] The motor vehicle 1 shown in FIG. 1 is an electric vehicle having an electric energy accumulator 3 as the traction battery. The motor vehicle 1 in the state shown in FIG. 1 is electrically connected detachably to the charging station 2 for the charging of the energy accumulator 3. The charging station 2 is a stationary charging column, not being represented further in FIG. 1, and is connected to an energy source, such as a public electricity grid and/or to a solar installation and/or the like.

[0048] In order to form the detachable electrical connection between the motor vehicle 1 and the charging station 2, there is provided at the motor vehicle 1 side an electric interface 4 and at the charging station 2 side an electric interface 5. The electric interface 4 at the motor vehicle side is configured as a charging socket 6 and the electric interface 5 at the charging station side is configured as a charging cable 7 with a plug 8 which can be inserted into the charging socket 6. Although in the embodiments shown the charging cable 7 is firmly connected to the charging station 2 and thus is a component thereof, the charging cable 7 may be a separate component, produced at both ends to form a corresponding plug connection, namely on the one side with the motor vehicle 1 and on the other side with the charging station 2.

[0049] The motor vehicle 1 is connected to the charging station 2 moreover across a detachable cooling fluid connection, by means of which a cooling fluid 9 can be taken from the charging station 2 to the motor vehicle 1. In the present instance, water is used as the cooling fluid 9. In order to form the cooling fluid connection, a cooling fluid interface 10 of the motor vehicle 1 and a cooling fluid interface 11 of the charging station 2 are provided. The cooling fluid interface 10 at the motor vehicle side is configured as a connection nozzle 12 and the cooling fluid interface 11 at the charging station side is configured as a hose 13 having a connector plug 14 which can be inserted into the connection nozzle 12.

[0050] By means of the cooling fluid connection, the cooling fluid 9 can be taken from the charging station 2 to a cooling element 15 of the motor vehicle 1. The cooling element 15 in the embodiments is configured as a cooling plate standing in thermal contact with the energy accumulator 3, through which cooling ducts not otherwise represented run. The cooling fluid 9 flows through the cooling ducts after being supplied to the cooling element 15. In this process, thermal energy is transferred from the energy accumulator 3 to the cooling element 15 and from the cooling element 15 in turn to the cooling fluid 9, so that a cooling of the energy accumulator 3 occurs during the charging process of the motor vehicle 1.

[0051] As regards the cooling element 15, this may be a heat exchanger, which is incorporated in a cooling circuit 46 provided independently of the charging station at the motor vehicle 1 side. The cooling circuit 46 is shown by broken line in FIG. 1, omitting any further components involved in it. A coolant circulates in the cooling circuit 46, so that thermal energy is transferred from the energy accumulator 3 to a cooling plate standing in thermal contact with the energy accumulator 3, being included in the cooling circuit 46 and having the coolant flowing through it. The coolant then flows through the heat exchanger, whereby the heat is transferred to the cooling fluid 9 flowing through the heat exchanger.

[0052] The cooling circuit 46 of the motor vehicle 1 can be provided exclusively for the transfer of thermal energy from the energy accumulator 3 to the cooling element 15. Alternatively, the cooling circuit 46 can be provided as an active cooling circuit, where “active” means that a further cooling effect with regard to the coolant also occurs in the cooling circuit 46 itself, apart from the cooling element 15. Thus, the cooling circuit 46 can work on the model of a refrigerating machine. A further heat exchanger can be incorporated in the cooling circuit 46, which is itself coupled to a refrigerant circuit. The cooling circuit 46 can comprise a further heat exchanger, in which the coolant is cooled for example by means of air cooling. The cooling circuit 46 can be designed and provided, in particular, for cooling the energy accumulator 3 in a driving operation of the motor vehicle 1. The cooling effect realized by means of the cooling circuit 46 is correspondingly intensified during the charging process in the method described herein.

[0053] The energy accumulator 3 may stand in thermal contact with at least one additional cooling element not represented in the figures, which in turn is incorporated in a separate cooling circuit. In this case, the cooling element 15 is used in addition to the further cooling element, not shown, for the temperature control of the energy accumulator 3, wherein both cooling elements can work independently of and separately from each other, since they are incorporated in different cooling circuits.

[0054] The charging station 2 comprises a cooling fluid reservoir 16, provided as a water tank, the cooling fluid 9 contained therein being taken by means of a cooling fluid delivery device 17, designed as a pump, from the cooling fluid reservoir 16 to the cooling element 15. Alternatively to the cooling fluid reservoir 16, it can be provided that the charging station 2 is connected to a cooling fluid source, such as a public water supply grid. This can also be the case in the embodiments shown here, so that the cooling fluid reservoir 16 is automatically replenished as soon as the level of the cooling fluid 9 in the cooling fluid reservoir 16 falls below a predetermined minimum level. Furthermore, it can be provided that the cooling fluid reservoir 16 of the charging station 2 can be replenished by means of a rain water catchment and/or a pump installation, by means of which water can be drawn from a local aquifer or from ground water.

[0055] Regarding the method described herein, the liquid cooling fluid 9 may be brought together with a gas before or during the feeding to the cooling element 15, so that the liquid cooling fluid 9 forms together with the gas a cooling fluid/gas mixture. The gas used in the present instance is ambient air. Thus, the cooling element 15 receives not only the liquid cooling fluid 9, but also the two-phase mixture comprising the liquid cooling fluid 9 and the gas. This has the effect that, when the thermal energy is transferred from the cooling element 15 to the cooling fluid 9, at least a portion of the cooling fluid 9 is evaporated into the gas. Otherwise put, a portion of the liquid cooling fluid 9 beneath the boiling temperature of the cooling fluid 9 is transformed into the gaseous state, so that the gas becomes enriched in the gaseous cooling fluid 9. Specifically, the water vapor content increases for the ambient air present in the mixture. Additional energy is required during the evaporation process to bring about a cooling effect in regard to the coolant 9, so that ultimately the cooling effect of the cooling fluid 9 on the cooling element 15 or the energy accumulator 3 is heightened.

[0056] The gas is taken to the liquid cooling fluid 9 by means of a gas delivery device 18. In the present case, this is a gas delivery pump or a fan for drawing in air from the surroundings 19. The gas delivery device 18 in the embodiment shown in FIG. 1 is a component of the charging station 2, while the feeding of the gas to the cooling fluid 9 occurs via a gas connection, by which the motor vehicle 1 and the charging station 2 are detachably connected to each other. The charging station 2 has an intake opening 20, by which the ambient air can be drawn in as the gas by means of the gas delivery device 18. In order to form the gas connection, the motor vehicle 1 comprises a gas connection interface 21 and the charging station 2 comprises a gas connection interface 22. The gas connection interface 21 at the motor vehicle side is configured as a connection nozzle 23 and the gas connection interface 22 at the charging station side is configured as a hose 24 having a connector plug 25, which can be inserted into the connection nozzle 23. In place of the gas connection, it can be provided that the gas is supplied to the liquid cooling fluid 9 via an air duct 27, which connects the intake opening 20 to a cooling fluid line 42 of the charging station 2 leading to the cooling fluid interface 11, at the charging station side. The air duct 27 is indicated by a broken-line arrow in FIG. 1. In this case, the gas connection and the corresponding interfaces 21, 22 are eliminated.

[0057] The components 6, 8, 12, 14, 21 and 25 of the plug connections described in the context of FIG. 1 can be provided as a common plug connection 26, so that a user when connecting the motor vehicle 1 to the charging station 2 does not need to hook up multiple plugs separately, but only a single plug. The common plug connection 26 is indicated schematically in the figures by the broken-line box. The charging cable 7 as well as the hoses 13, 24 may also be in this case combined or bundled into one common multistrand connection line. As already explained above in connection with the charging cable 7, the common connection line may be a separate component, configured to form a common plug connection at both ends, namely, to the motor vehicle 1 on the one hand and to the charging station 2 on the other hand.

[0058] In regard to FIG. 1, the cooling fluid/gas mixture after the transfer of the thermal energy is discharged entirely into the surroundings 19. For this, the cooling element 15 is connected via a mixture drain line 28 to a mixture outlet opening 29 of the motor vehicle 1. The draining of the mixture into the surroundings 19 is particularly free of problems, because it is a two-phase mixture of water and air enriched in water vapor, which is neither toxic nor harmful to the environment. The mixture outlet opening 29 is situated in the area of the outer skin of the motor vehicle 1, such as beneath a hood, or in the area of the motor vehicle underbody.

[0059] In the following, the arrangement shown in FIG. 2 will be explained, and it corresponds to the arrangement shown in FIG. 1, except for the differences explained below. These systems differ in that the gas delivery device 18 is a component of the motor vehicle 1. Accordingly, the gas delivery device 18 can draw in ambient air as the gas via an intake opening 30 of the motor vehicle 1 and then supply it to the liquid cooling fluid 9 via an air duct 31, which leads from the intake opening 30 to the cooling element 15, at the motor vehicle side. In addition or alternatively, the air duct 31 can also lead from the intake opening 30 to a cooling fluid line 32 leading to the cooling element 15.

[0060] Referring to FIG. 3, a third arrangement with the motor vehicle 1 and the charging station 2 will be explained. By contrast with FIG. 1, in this embodiment it is provided that the cooling fluid/gas mixture after the transfer of the thermal energy is taken to a phase separator 33 of the charging station 2, by means of which a liquid phase 34 of the cooling fluid/gas mixture, consisting of the liquid cooling fluid 9, and a gaseous phase 35, consisting of the evaporated cooling fluid 9 and the gas, are separated from each other. Thus, the cooling fluid/gas mixture is not given off to the surroundings 19, as in FIGS. 1 and 2, but rather it is taken back to the charging station 2 via a detachable return connection connecting the motor vehicle 1 and the charging station 2.

[0061] In order to form the return connection, the motor vehicle 1 comprises a return connection interface 36 and the charging station 2 comprises a return connection interface 37. The return connection interface 36 at the motor vehicle side is configured as a connection nozzle 38 and the return connection interface 37 at the charging station side is configured as a hose 39 having a connector plug 40. The plug connection formed by means of the connection nozzle 38 and the connector plug 40 can also be formed in the context of the common plug connection 26. The hose 39, moreover, can be part of the multistrand common connection line comprising the components 7, 13, 24.

[0062] In the embodiment of FIG. 3, the charging station 2 comprises a liquid phase drain line 41, which leads from the phase separator 33 to the cooling fluid reservoir 16 and by which the liquid phase 34 is again taken to the liquid cooling fluid 9 at the charging station side. In addition or alternatively, the liquid phase drain line 41 can lead from the phase separator 33 to a cooling fluid line 42 leading from the cooling fluid reservoir 16 to the cooling fluid interface 11. Moreover, the charging station 2 comprises a gas phase drain line 43, which leads from the phase separator 33 to a gas phase drain opening 44 of the charging station 2, the gaseous phase 35 being discharged by means of the gas phase drain line 43 via the gas phase drain opening 44 into the surroundings 19. As regards the hose 24 provided in this embodiment or the gas connection, the gas can instead be taken to the liquid cooling fluid 9, as already explained in connection with FIG. 1, via the air duct 27, which connects the intake opening 20 to the cooling fluid line 42 of the charging station 2 leading to the cooling fluid interface 11, at the charging station side.

[0063] In the following, reference is made to FIG. 4, comprising a further arrangement comprising the motor vehicle 1 and the charging station in the configuration already shown in FIG. 1. The arrangement corresponds to the system shown in FIG. 3, but with the difference that the phase separator 33 is a component of the motor vehicle 1. Thus, the detachable return connection is not provided for this arrangement, but instead the motor vehicle 1 comprises the liquid phase drain line 41, which leads from the phase separator 33 to the cooling fluid line 32 leading to the cooling element 15, so that the liquid phase 34 is taken to the liquid cooling fluid 9 at the motor vehicle side before the transfer of the thermal energy. The liquid phase drain line 41 can also lead directly to the cooling element 15. Moreover, the motor vehicle 1 comprises the gas phase drain line 43, which leads from the phase separator 33 to the gas phase drain opening 44 of the motor vehicle 1, the gaseous phase 35 being taken across the gas phase drain line 43 and the gas phase drain opening 44 to the surroundings 19.

[0064] Regarding the liquid phase 34, it can be alternatively provided that this is returned to the charging station 2 or to the cooling fluid reservoir of the charging station 2 across a detachable return connection connecting the motor vehicle 1 and the charging station 2, as was described in connection with FIG. 3. This connection is indicated in FIG. 4 by means of the broken-line arrow 45, while details regarding the interfaces 36, 37 are not shown for sake of clarity.

[0065] The arrangement shown in FIG. 5 corresponds to the arrangement shown in FIG. 4, but with the difference that the gas delivery device 18 is not a component of the charging station 2, but rather of the motor vehicle 1. Accordingly, what was explained in this regard in connection with FIG. 2 holds equally for the motor vehicle 1 and system of FIG. 5.

[0066] The arrangement shown in FIG. 6 corresponds to a modification of the arrangement shown in FIG. 3, which differ from each other in that in FIG. 3 the gas connection is formed by means of the interfaces 21, 22 between the motor vehicle 1 and the charging station 2, while in FIG. 6 the gas is taken by means of the gas delivery device 18 to the cooling fluid line 42, which leads to the cooling fluid interface 11 at the charging station side. Thus, the gas is not taken to the cooling fluid 9 at the motor vehicle side, but already at the charging station side. Apart from the cooling element 15, all the components needed for the cooling process, such as the phase separator 33 or the delivery pump or gas delivery device 18, are accommodated at or inside the charging station 2 external to the motor vehicle, so that the entire technology and functionality of the cooling fluid conditioning and preparation is provided outside the motor vehicle.

[0067] German patent application no. 10 2021 132151.4, filed Dec. 7, 2021, to which this application claims priority, is hereby incorporated herein by reference, in its entirety.

[0068] Aspects of the various embodiments described above can be combined to provide further embodiments. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled.