METHOD FOR THE THERMAL CONDITIONING OF TRACTION BATTERIES

Abstract

A method is disclosed for the thermal conditioning of an electrochemical accumulator of a vehicle, wherein data are received and/or ascertained, and the data comprise a planned or expected parking duration, ambient data of the vehicle, thermal properties of the electrochemical accumulator, the received and/or ascertained data are evaluated, and based on the evaluated data steps are taken for the thermal conditioning of the electrochemical accumulator by the control unit prior to a parking of the vehicle, during a parking of the vehicle, or after a parking of the vehicle, wherein the steps for the thermal conditioning of the electrochemical accumulator remove or add thermal energy directly or indirectly to or from the electrochemical accumulator by a battery cooling circuit and/or a main cooling circuit of the vehicle.

Claims

1. A method for thermal conditioning of an electrochemical accumulator of a vehicle, comprising: receiving and/or ascertaining data including a planned or expected parking duration, ambient data of the vehicle, and thermal properties of the electrochemical accumulator; evaluating the received and/or ascertained data; and based on the evaluated data, taking action to thermally condition the electrochemical accumulator prior to parking of the vehicle, during parking of the vehicle, or after parking of the vehicle, wherein the action removes or adds thermal energy directly or indirectly to or from the electrochemical accumulator by a battery cooling circuit and/or a main cooling circuit of the vehicle.

2. The method according to claim 1, wherein, for the purpose of transferring thermal energy from the main cooling circuit to the electrochemical accumulator, the thermal energy is transferred via a heat exchanger and/or via a heat accumulator between the main cooling circuit and the battery cooling circuit and the thermal energy transferred to the battery cooling circuit is furnished to the electrochemical accumulator.

3. The method according to claim 1, wherein the action is initiated prior to a parking of the vehicle or during a parking of the vehicle in the form of providing thermal energy to the electrochemical accumulator while taking into account a thermal cooldown curve of the electrochemical accumulator and while taking into account the parking duration of the vehicle, and the electrochemical accumulator is briefly warmed up in such a way that a predefined operating temperature of the electrochemical accumulator is maintained after the parking duration of the vehicle.

4. The method according to claim 1, wherein the action is initiated after a parking of the vehicle in the form of providing thermal energy to the electrochemical accumulator while taking into account a thermal cooldown curve of the electrochemical accumulator and while taking into account the parking duration of the vehicle, and a conditioning duration is ascertained, ending before the expiration of the parking duration, and the steps taken for the thermal conditioning are carried out during the conditioning duration.

5. The method according to claim 1, wherein a coolant of the battery cooling circuit and/or the main cooling circuit of the vehicle is heated for providing thermal energy by taking up braking recuperation energy in the form of thermal energy and/or by taking up heat from at least one consumer of the vehicle.

6. The method according to claim 1, wherein the data on a planned or anticipated parking duration are received from a manual entry or ascertained by a self-learning system.

7. The method according to claim 6, wherein the self-learning system includes a neural net which has been trained in advance.

8. The method according to claim 1, wherein the method is performed by a control unit of the vehicle.

9. A vehicle, comprising: a main cooling circuit; a battery cooling circuit; and at least one electrochemical accumulator, which is coupled thermally to the battery cooling circuit and directly or indirectly to the main cooling circuit, and wherein the vehicle is adapted to implement a method for thermal conditioning the electrochemical accumulator comprising: receiving and/or ascertaining data including a planned or expected parking duration, ambient data of the vehicle, and thermal properties of the electrochemical accumulator; evaluating the received and/or ascertained data; and based on the evaluated data, taking action to thermally condition the electrochemical accumulator prior to parking of the vehicle, during parking of the vehicle, or after parking of the vehicle, wherein the action removes or adds thermal energy directly or indirectly to or from the electrochemical accumulator by the battery cooling circuit and/or the main cooling circuit of the vehicle.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0042] Embodiments of the invention are represented schematically in the drawings and shall be described further with reference to the drawings.

[0043] FIG. 1 shows a vehicle layout according to a first embodiment of the invention.

[0044] FIG. 2 shows a vehicle layout according to a second embodiment of the invention.

[0045] FIG. 3 shows a vehicle layout according to a third embodiment of the invention.

DETAILED DESCRIPTION

[0046] Embodiments of the invention shall now be explained, making reference to the drawings. The same components are given the same reference symbols.

[0047] FIG. 1 shows a vehicle layout 1 according to a first embodiment of the invention. The vehicle layout 1 comprises a main cooling circuit 2 and a battery cooling circuit 4.

[0048] Furthermore, the vehicle layout 1 comprises at least one electrochemical accumulator 6. The electrochemical accumulator 6 is coupled thermally to the battery cooling circuit 4 and directly or indirectly to the main cooling circuit 2.

[0049] The main cooling circuit 2 may be coupled thermally to a combustion engine 8 of the vehicle. The combustion engine 8 is designed as a drive motor, for example.

[0050] The electrochemical accumulator 6 is designed as a traction battery and is based on a lithium ion technology in the embodiment shown. The electrochemical accumulator 6 may be designed as a battery system or as a battery module with multiple battery cells.

[0051] In place of the combustion engine 8, any given consumer which generates heat also can be connected thermally to the main cooling circuit 2 or the battery cooling circuit 4 in order to provide thermal energy for the electrochemical accumulator 6.

[0052] FIG. 1 illustrates a regular operation of the vehicle, during which the temperature of the electrochemical accumulator 6 lies in an optimal temperature range, for example 30° C. to 50° C. The thermal regulation of the electrochemical accumulator 6 is taken on entirely by the battery cooling circuit 4.

[0053] Upon parking the vehicle, steps are taken so that optimal operating conditions will prevail for the electrochemical accumulator 6 in the form of a so-called “comfort temperature” the next time it is started. For this, a lot of information and data are registered and evaluated by a control unit 10 (FIG. 2).

[0054] A predicted or anticipated parking duration of the vehicle, a manual entry of the parking duration by a driver, ambient data such as an expected ambient temperature from weather forecast information and the thermal properties of the electrochemical accumulator 6 can be received and evaluated by the control unit 10 (FIG. 2).

[0055] The anticipated parking duration of the vehicle can be determined by a self-learning system, such as a neural net. The thermal properties of the electrochemical accumulator 6 may take account of an entire battery system with the respective battery cells in a package and in a housing. In this way, a cooldown curve dependent on the ambient temperature and the temperature of the electrochemical accumulator 6 can be created or used.

[0056] If the vehicle has been parked, it is possible to determine in the context of the method described herein whether steps should be taken for the thermal conditioning of the electrochemical accumulator 6 already during the parking of the vehicle or after a parking of the vehicle. This function can be implemented by the control unit 10 (FIG. 2) of the vehicle layout 1.

[0057] In particular, the steps may be initiated a sufficient time before the anticipated or planned vehicle start, in order to condition the electrochemical accumulator 6 with thermal energy so that it can find itself in an optimal temperature range regardless of the parking duration and independently of the ambient conditions during the vehicle start.

[0058] The heat is furnished through the low-temperature battery cooling circulation 4. The steps are initiated directly upon parking the vehicle, for example if the parking duration falls below a predefined threshold value.

[0059] If the parking duration is greater than the predefined threshold value, a conditioning duration can be determined, serving as the basis for a starting of the steps for the thermal conditioning after the parking of the vehicle.

[0060] A starting time for initiating the steps can be determined by the ascertained parking duration, minus the conditioning duration.

[0061] For example, the heat capacity of the electrochemical accumulator 6 together with an introduced coolant (each having different temperatures) is used for initiating the steps upon parking or during the parking of the vehicle and a hybrid temperature is calculated. This will be adjusted such that the maximum temperature is never exceeded.

[0062] Alternatively, the thermal energy is only supplied to the electrochemical accumulator 6 from a heat accumulator 12 after the parking of the vehicle and shortly before starting the vehicle or after expiration of the parking duration. This is represented in FIG. 2 in the form of a vehicle layout 1 according to a second embodiment of the invention.

[0063] The heat accumulator 12 may form an indirect thermal coupling between the main cooling circuit 2 and the battery cooling circuit 4.

[0064] Optionally, a portion of the coolant of the battery cooling circuit 4 may also be heated further during vehicle operation by excess braking recuperation and a heating element. Shortly after parking the vehicle, this coolant is then provided to the battery system or used to heat the electrochemical accumulator 6.

[0065] In order to carry out the thermal conditioning afterwards upon parking or during a parking or after a parking of the vehicle and before a starting of the vehicle, thermal energy can be removed from the heat accumulator 12 and supplied to the electrochemical accumulator 6.

[0066] The heat accumulator 12 is fed by the main cooling circuit 2 and/or by the battery cooling circuit 4 during operation of the vehicle. If need be, for example if the temperature falls below 30° C. in the electrochemical accumulator 6, the thermal energy can be removed from the heat accumulator 12 in the form of a step taken for the thermal conditioning.

[0067] Enough thermal energy may be stored in the heat accumulator 12 so that the electrochemical accumulator 6 can be warmed up to at least 30° C. for the starting of the vehicle.

[0068] The heat accumulator 12 may contain, for example, a solid or liquid material with a high specific heat capacity, in order to serve as a thermal buffer. Depending on the design, the heat accumulator may be configured as a latent heat accumulator.

[0069] FIG. 3 shows a vehicle layout 1 according to a third embodiment of the invention. A further step taken for the thermal conditioning of the electrochemical accumulator 6 is illustrated. After parking the vehicle, thermal energy is transferred from the main cooling circuit 2 to the battery cooling circuit 4 and thus to the electrochemical accumulator 6 during the conditioning operation. For this indirect heat transfer, a heat exchanger 14 is provided, which thermally couples the main cooling circuit 2 to the battery cooling circuit 4.

[0070] Enough heat is provided to the electrochemical accumulator 6 so that during the next starting of the vehicle there will still prevail approximately 30° C. in the electrochemical accumulator 6.

[0071] The initiating of the steps taken for the thermal conditioning of the electrochemical accumulator 6 may be done by the control unit 10. The starting time of the steps, the conditioning duration due to the steps, and the kind of steps taken can be determined by the control unit 10 based on the data received. The control unit 10 may be configured as a neural net, which has been trained in advance. The control unit 10 may work as a self-learning unit and in particular it may estimate the parking duration of the vehicle automatically, in order to make possible a timely initiating of the thermal conditioning.

[0072] German patent application no. 10 2020 128052.1, filed Oct. 26, 2020, to which this application claims priority, is hereby incorporated herein by reference, in its entirety.

[0073] 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.