Method for operating a heat exchanger and energy storage heat exchange system

Abstract

The present invention relates to a method for operating a heat exchanger and an energy storage device heat exchange system, which energy storage device heat exchange system has: an energy storage device including a plurality of electrochemical battery cells for providing electrical energy; a flow channel for a flow of a heat exchange medium to flow through the battery cells arranged one after the other in the flow direction, the battery cells respectively having a heat exchange surface circulated by the heat exchange medium and capable of exchanging heat between the heat exchange medium and the battery cells through the heat exchange surface, the first battery cell in the flow direction having a first heat exchange surface, and the second battery cell located downstream of the first battery cell having a second heat exchange surface larger in size than the first heat exchange surface; a control and / or regulating device and a device for regulating a volume flow, the control and / or regulating device being operatively connected to the device for regulating a volume flow in such a way that the volume flow can be controlled and / or regulated by the control and / or regulating device.

Description

Technical Field

[0001] The invention relates to a method for operating a heat exchanger for an energy storage device comprising a plurality of electrochemical cells and to an energy storage device heat exchange system. Technical Background

[0002] In electrochemical energy storage systems, such as batteries, the required voltage level is provided by connecting individual electrochemical cells one after the other. A plurality of cells can be assembled into individual modules. The required voltage is then generated by connecting the corresponding modules in series with the corresponding number of cells.

[0003] A typical application area for such energy storage devices is in the field of electric vehicles, in particular electrically driven motor vehicles, but the application is not limited thereto. The electric motor for driving the motor vehicle requires high electrical power from the energy storage device or its electrochemical cells during acceleration.

[0004] When energy is discharged from an energy storage device or from an electrochemical cell, a power loss in the cell, which is dependent on the current intensity, is caused by the sum of all resistances (e.g. internal cell resistance, contact resistance, etc.), and is converted into heat. This power loss heats the energy storage device and the cell, so that the energy storage device or the cell of the energy storage device can overheat if the heat energy is not discharged.

[0005] Therefore, cooling devices or heat exchangers are provided for the energy storage device in order to avoid overheating. In this case, heat exchangers are primarily used which are integrated into an existing heat exchanger circuit of a motor vehicle, in particular into a cooling circuit of a motor vehicle. Such heat exchangers are operated, for example, with a water / glycol mixture. To avoid short circuits, the electrically conductive water / glycol mixture must not come into contact with the electrochemical cells, in particular with their electrical contact surfaces; the same applies to the heat sink through which the water / glycol flows, which is usually made of metal for better heat conduction.

[0006] However, if a non-conductive medium is used for the heat exchange process, in particular for cooling, such as transformer oil, the battery cells are brought into direct contact with the medium. The heat exchange medium flows around the heated battery cell, exchanges heat, in particular absorbs heat from the battery cell, and circulates to the next battery cell. In practice, this is a continuous process. However, this method leads to different temperatures of the battery cells circulated by the heat exchange medium, because the medium heats up during its flow from battery cell to battery cell and thus reduces the amount of heat transferred to the medium from battery cell to battery cell.

[0007] However, higher temperatures accelerate the aging of electrochemical cells, so that the cells of the energy store age to varying degrees and the voltage level of the energy store changes depending on the failure of the respectively oldest cell, until individual cells, individual modules or the entire energy store have to be replaced. Summary of the invention

[0008] The technical problem to be solved by the present invention is therefore to provide a method, a control and / or regulating device, and an energy storage system using means that are as simple as possible in structure, by means of which the failure probability of the energy storage system is reduced.

[0009] The technical problem is solved by the subject matter of the independent claim of the present invention. Advantageous improvements of the present invention are given in the dependent claims, the specification and the drawings of the specification. In particular, an independent claim of one claim type can also be expanded similarly to an independent claim of another claim type. Other advantageous embodiments and improvements of the present invention are given by the description of the dependent claims and the drawings of the specification.

[0010] A method according to the invention is provided as a method for operating a heat exchanger for an energy storage device comprising a plurality of electrochemical battery cells, wherein a heat exchange medium circulates successively around the battery cells in a flow direction to achieve heat exchange, wherein the battery cells each have a heat exchange surface via which heat exchange mainly takes place between the medium and the corresponding battery cells, wherein a first battery cell in the flow direction exchanges heat with the heat exchange medium via a first heat exchange surface, and a second battery cell located downstream of the first battery cell exchanges heat by means of a second heat exchange surface which is larger in size than the first heat exchange surface, wherein the volume flow of the heat exchange medium is adjusted such that, for a selected operating node of the battery cells, the temperature difference between the temperature of the first battery cell and the temperature of the second battery cell is reduced, in particular minimized.

[0011] The described method can be used to equalize the temperature-related aging of the battery cells by reducing the temperature differences between the battery cells. Usually, the first battery cell in the flow direction through which a heat exchange medium circulates and the last battery cell in the flow direction through which the same heat exchange medium circulates have a large temperature difference according to this arrangement. By increasing the size of the heat exchange surface of the battery cells in the flow direction, the temperature difference between these battery cells can be reduced. As a result, the temperature-related aging of the battery cells can be equalized and premature aging will not lead to battery cell failure. The method is already effective when the heat exchange surface is enlarged in such a way that the first heat exchange surface of the first battery cell is enlarged compared to the second heat exchange surface of the second battery cell located downstream. That is, battery cells with heat exchange surfaces of different sizes in the flow direction are provided, wherein a smaller heat exchange surface is provided downstream than in upstream.

[0012] The battery cells can also be designed as battery cell groups with respectively identical heat exchange surfaces, wherein the size of the heat exchange surface is increased in the flow direction for the battery cell group. In a particularly advantageous embodiment, the size of the heat exchange surface of the battery cells arranged one after the other in the flow direction is gradually increased. In other words, the heat exchange surface increases from each battery cell to the next adjacent battery cell in the flow direction, and the battery cells are circulated in the flow direction by the same heat exchange medium flow, in particular by a coolant flow. The same medium flow is to be understood as that no significant heat exchange takes place between the flows passing through the individual battery cells or that the absorption of the medium flow is not caused by heat exchange or heat absorption of the circulated battery cells.

[0013] Likewise, starting from the first battery cell in the flow direction, a heat exchange surface of increasing size can be provided for each battery cell that follows in the flow direction.

[0014] A device used for heat exchange is understood to be a heat exchanger. For this purpose, a flowable substance can be used as a medium for heat exchange, in particular a gas or a liquid, which is in particular not electrically conductive.

[0015] This method can be used for cooling the battery cells and for heating the battery cells. However, the cooling of the battery cells usually comes first, especially when the corresponding energy storage device is used as a drive for a motor vehicle.

[0016] However, in cool ambient conditions, it may also be necessary to heat the battery cells in order to maintain the capacity of the energy storage device even at low external temperatures. The low external temperatures may lead to battery cell temperatures that have a negative impact on the energy storage or energy output capacity. This can be avoided by heating the battery cells.

[0017] At least two battery cells, but in particular a plurality of battery cells arranged one behind the other in the flow direction are considered as a plurality of battery cells. Advantageously, 7 to 15, in particular 10 battery cells are arranged one behind the other in the flow direction and circulated by the same heat exchange medium flow, in particular by a coolant flow.

[0018] If the battery cells have a sufficiently high electrical conductivity, for example, they are made of metal, the boundaries of the battery cells can serve as heat exchange surfaces. Separate structures that enable heat exchange can also be provided on the battery cells, such as separate cooling strips or separate cooling surfaces, such as cooling fins that protrude into the heat exchange medium flow.

[0019] Advantageously, the first battery cell in the flow direction is used as the first battery cell and the last battery cell in the flow direction is used as the second battery cell. In particular, the last battery cell is the battery cell in the flow direction before the heat exchange medium is fed to a heat exchange process that is counter to the heat exchange taking place in the energy storage device. If the medium is heated in the energy storage device, the cooling of the medium can be a counter heat exchange process and vice versa.

[0020] In one embodiment of the method, a first temperature of the medium is detected at a first position and a second temperature is detected at a second position located downstream, and the volume flow is adjusted according to the conditions provided by the selected operating node, in particular according to the provided battery cell current, so that the temperature difference between the battery cells is reduced, in particular minimized.

[0021] Advantageously, the first position is located before the position of the first battery cell in the flow direction, and the second position is located after the last battery cell circulated by the same heat exchange medium flow in the flow direction. In addition to the first and second positions, other temperatures can also be collected at other positions, preferably at positions located between the first and second positions. In particular, it can be arranged that the first position is before the first battery cell and the second position is after the last battery cell circulated by the same heat exchange medium. Preferably, the temperature is collected by means of a corresponding temperature sensor.

[0022] Advantageously, the volume flow is regulated by means of a corresponding, pre-acquired representative family of characteristics for the energy storage system or a corresponding component of the energy storage system, for example a module with a plurality of battery cells, or more precisely a module through which the same medium flow flows in a heat-exchanging manner or through which it flows. In this case, the family of characteristics covers different operating nodes, in particular the battery cell currents that occur during operation of the energy storage. The operating nodes or the battery cell currents are related to the heating of the corresponding battery cells. In addition, the family of characteristics preferably includes the temperatures on the inlet side and the outlet side of the heat exchange medium and reflects which volume flow of the heat exchange medium is required under these conditions in order to minimize the temperature distribution between the battery cells. Based on these families of characteristics that can be stored in a corresponding control device, the volume flow of the heat exchange medium can be regulated in such a way that the temperature difference of the battery cells between the first position and the second position of the medium flow temperature measurement is as small as possible.

[0023] The maximum temperature difference between the battery cells in the first and second position can be determined and, if necessary, also output, for example as a function of the actual operating point and the detected medium temperature. However, this is not absolutely necessary for the regulation of the volume flow.

[0024] If the operating point changes by drawing more or less power from the battery cell than before or if the temperature of the medium at the first or second point changes, the volume flow can be adjusted accordingly again.

[0025] In another advantageous embodiment of the method, a first temperature of a first battery cell in the flow direction is detected or acquired, and a second temperature of a second battery cell located downstream is detected or acquired, wherein the volume flow is adjusted in such a way that the temperature difference between the first temperature and the second temperature is reduced. If necessary, the temperature of the first battery cell and the temperature of the second battery cell can be calculated by the current of the battery cell and the relevant resistance, and if necessary, by other existing thermal diffusion conditions in the battery cell. However, it is also possible to arrange a temperature sensor at the battery cell, in particular in the region of the heat exchange surface or on the heat exchange surface.

[0026] Preferably, by acquiring the temperature of the first battery cell in the flow direction and the temperature of the last battery cell in the flow direction, the temperature difference between the two battery cells is known, and the volume flow can be adjusted in such a way that the temperature difference is reduced. In this way, a control loop can be advantageously set up, which dynamically adjusts the volume flow determined by the actual temperature difference or temperature difference and minimizes the temperature difference. In principle, for more than two battery cells, corresponding temperature sensors can also be set for all battery cells circulated by the same heat exchange medium flow, if necessary. Preferably, the acquired data is transmitted to the corresponding control and / or regulation device.

[0027] It is therefore advantageous if the volume flow is controlled and / or regulated by a control and / or regulating device. This allows unfavorable temperature differences to be reduced or minimized quickly and dynamically.

[0028] The control and / or regulating device according to the invention is operatively connected (wirkungsverbinden, or: effectively connected, operably connected) to a device for regulating the volume flow of a heat exchange medium, wherein the control and / or regulating device can have a machine-readable program code, which includes control and / or regulating commands, which, when executed, cause the control and / or regulating device to carry out the method according to any one of claims 1 to 5. Furthermore, the control and / or regulating device can be operatively connected to a temperature device for the heat exchange medium, so that the control and / or regulating device can influence both the volume flow and the temperature of the heat exchange medium in such a way that the temperature differences of the battery cells are reduced or, more precisely, minimized.

[0029] An energy storage device heat exchange system according to the invention comprises an energy storage device comprising a plurality of electrochemical cells for providing electrical energy, the energy storage device heat exchange system having a flow channel for a heat exchange medium flow through the cells in a flow direction, wherein the cells are arranged one behind the other in the flow direction, wherein the cells each have a heat exchange surface, through which a medium can flow, and through which heat can be exchanged between the medium and the cells, wherein a first cell in the flow direction has a first heat exchange surface, wherein a second cell located downstream of the first cell has a second heat exchange surface, wherein the second heat exchange surface is larger than the first heat exchange surface; the energy storage device heat exchange system having a control and / or regulating device according to claim 6 and a device for regulating a volume flow, wherein the control and / or regulating device is operatively connected to the device for regulating a volume flow in such a way that the volume flow can be controlled and / or regulated by the control and / or regulating device, in particular in such a way that a temperature difference between a first temperature of the first cell and a second temperature of the second cell is reduced, in particular minimized.

[0030] This energy storage heat exchange system can be used to cool and heat the battery cells.

[0031] The boundaries of the battery cells can serve as heat exchange surfaces, especially when they are sufficiently heat-conductive, for example made of metal. In this case, the battery cells can be placed in a housing that is usually thermally insulated. By mechanically rigidly connecting the housings to each other, the housings can be used to construct corresponding modules consisting of battery cells. The housing for the battery cells has one or more recesses, which are designed so that the heat exchange medium can contact the battery cells at the recesses so that heat exchange between the medium and the battery cells can be achieved at the position of the housing at the recesses. Recesses of different sizes in the housing can provide heat exchange surfaces of different sizes for the battery cells without modifying the battery cells. It is also possible to provide a separate structure on the battery cell that enables heat exchange, such as a separate heat sink or a separate cooling surface that protrudes into the flow of the heat exchange medium in order to discharge heat from the battery cell or absorb heat for the battery cell.

[0032] In a further advantageous embodiment, the size of the heat exchange surface is increased stepwise for battery cells arranged one behind the other in the flow direction. In other words, the size of the heat exchange surface increases from each battery cell or each battery cell group to the next battery cell or battery cell group arranged downstream. This is done in this way for at least 50% of the battery cells, advantageously for all battery cells, which can be circulated in the flow direction by the same heat exchange medium flow, in particular by a coolant flow.

[0033] It is also advantageous if the heat exchange surface increases in size from battery cell to battery cell in the downstream direction and is designed in such a way that a minimum value of the maximum temperature difference between the first battery cell in the flow direction and the last battery cell in the flow direction is achieved with a determined inlet temperature at a preset operating node and at a preset volume flow rate.

[0034] In one embodiment of the heat exchange system for an energy storage device, a first sensor for detecting the temperature of the medium is provided at a first position in the flow channel, and at least one second sensor for detecting the temperature of the medium is provided at a second position in the flow channel downstream of the first position, wherein the temperatures detected by the first and at least the second sensor can be fed to a control and / or regulating device. The presence of such a temperature sensor allows conclusions to be drawn about the current state of the system. In particular, the detected temperature allows the volume flow to be adjusted accordingly, so that the temperature differences of the battery cells in the medium flow are minimized.

[0035] In addition, conditions related to the actual working nodes of the battery cells (such as the current of the battery cells) can be transmitted to the control and / or regulation device, so that the volume flow of the heat exchange medium can be adjusted according to the working nodes of the battery cells and the collected temperature, and the temperature difference of the battery cells can be reduced by using this volume flow.

[0036] In a further advantageous embodiment of the heat exchange system for the energy storage device, the heat exchange medium is fed to a flow circuit which is not coupled to a heat exchange circuit for the vehicle cabin or the engine. This circuit is therefore only influenced by the parameters of the heat exchange system for the energy storage device and is independent of other heat exchange processes, in particular the required engine temperature and / or vehicle cabin temperature. This allows control and / or regulation interventions to be reduced, since the heat exchange processes of the battery cells are influenced by a small number of influencing variables. Control / regulation is simplified overall. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Advantageous embodiments of the present invention are described below with reference to the accompanying drawings. The accompanying drawings show:

[0038] Figure 1 is a first side view of an exemplary energy storage heat exchange system.

[0039] Figure 2 is for Figure 1 Second top view of the energy storage heat exchange system in.

[0040] Figure 3 is for Figure 1 and Figure 2 1. Method flow chart of an exemplary method flow of a method for operating a heat exchanger of an energy storage heat exchange system.

[0041] The accompanying drawings are only schematically shown and are only used to illustrate the present invention. The same or equivalent components are marked with the same reference numerals throughout. DETAILED DESCRIPTION

[0042] For ease of understanding, the following descriptions retain Figure 1 and Figure 2 The reference numerals in FIG.

[0043] Figure 1 A schematic view of an energy storage heat exchange system 1 is shown. The energy storage heat exchange system comprises an energy storage having a plurality of electrochemical cells 2 for discharging and / or absorbing electrical energy. The cells 2 are usually electrically connected in series.

[0044] Further battery cells 2 may be provided perpendicular to the plate plane or in the plate plane and surrounded by the energy storage device. Preferably, the battery cells are divided into modules having a certain number of, for example, 10 battery cells 2, characterized in that the same heat exchange medium 6 flows through these battery cells in the flow direction S in order to remove heat from the battery cells 2. Due to this modular structure, energy storage devices with almost any capacity can be constructed.

[0045] In this embodiment, the heat exchange medium 6 is designed as a non-conductive transformer oil, which is conveyed by means of a pump 9 to a flow channel 5 in which the battery cells 2 are arranged and the heat exchange medium 6 flows around the battery cells. The volume flow of the medium 6 in the flow channel 5 can be adjusted by means of the pump 9, for example by increasing or reducing the flow velocity of the medium or changing the pressure acting on the medium 6. For this purpose, it is advantageous to use an incompressible medium 6, which simplifies the adjustment of the volume flow. After the heat exchange medium 6 flows through the battery cells 2 and absorbs energy from the battery cells 2, the medium is conveyed to a further heat exchanger. There, the absorbed heat is discharged again to the environment or another medium to avoid continuous heating of the heat exchange medium 6. Preferably, the heat exchange medium 6 is conveyed to a circuit that is used only for cooling the battery cells 2 or cooling the energy storage device. Therefore, this heat exchange circuit is not coupled to other heat exchange circuits for example for the engine or the vehicle cabin.

[0046] According to the attached Figure 1 , each battery cell 2 has a heat exchange surface 4 of different size. In an embodiment, the respective battery cell has a good heat-conducting outer wall, for example a metal outer wall. The battery cell 2 is positioned in a housing 3, which, for example, forms a module so that a certain number of battery cells can be accommodated. The battery cells 2 are fixedly fastened in the flow channel 5 by the housing 3 that respectively accommodates the battery cells 2.

[0047] In this case, the housing 3 is made of a material with a lower thermal conductivity than the outer wall of the battery cell 2. For example, the housing is made of plastic. In this embodiment, the housing 3 surrounds the battery cell in the form of an outer cover so that substantially no heat exchange medium 6 can penetrate between the outer wall of the battery cell 2 and the housing 3. If the battery cell 2 is designed to be circular in cross section, the housing can have a cylindrical outer cover shape, wherein the inner diameter of the cylindrical outer cover substantially corresponds to the outer diameter of the battery cell 2.

[0048] Now, for battery cells 2 arranged one behind the other in the flow direction S, heat exchange surfaces 4 of different sizes are realized in such a way that the housing 3 has recesses of gradually increasing size in the flow direction S, in which the outer wall of the battery cell 2 can come into contact with the heat exchange medium. These recesses of the housing are distributed on the housing 3, in particular evenly distributed on the outer wall surface of the battery cell 2. Alternatively, as shown in the attached figure, Figure 1As shown, these recesses can be designed continuously. That is, the recesses are designed as continuous cylindrical shell parts, wherein the recesses each become larger in size for battery cells arranged one behind the other in the flow direction 2. In this area, in which the heat exchange medium 6 circulates around the outer wall of the battery cell 2, a heat flow from the hotter element (e.g., the battery cell 2) to the colder element (e.g., the medium 6) is generated. Usually, the battery cell 2 has a higher temperature than the medium 6, so as to promote the cooling of the battery cell 2, that is, a heat flow from the battery cell 2 to the medium 6, in this case the cooling medium, is generated.

[0049] Preferably, the surface size of the heat exchange surface 4 is determined in such a way that the temperature difference between the battery cells 2 is minimized at a preset working node and at preset medium flow parameters (especially the volume flow rate and the medium temperature at the inlet of the flow channel 5). Therefore, this is an optimization problem under known boundary conditions. As a result, the distribution of the corresponding heat exchange surface is achieved on the battery cells 2 through which the heat exchange medium flows. Thereby, the heat exchange surface is optimally determined for each battery cell. The housing 3 is adapted in the flow direction S so that the corresponding battery cells 2 each have a heat exchange surface 4 that minimizes the temperature difference. Thus, for different working nodes, the heat exchange surface 4 of the corresponding battery cell 2 remains constant in its size, but allows the temperature difference of the battery cell 2 or the minimum value of the temperature difference to be adjusted by changing the volume flow rate.

[0050] By defining the heat exchange surface 4 on the housing 3, the battery cells 2 can also be replaced quickly without further operations. Thus, a minimized temperature distribution is obtained without modifying the battery cells 2.

[0051] Furthermore, the energy storage heat exchange system 1 comprises at least two temperature sensors 7 and 8. Preferably, the first temperature sensor 7 is positioned on the inflow side of the medium flow in the flow channel 5, preferably upstream of the first battery cell 2 through which the medium 6 flows. Preferably, the second temperature sensor is arranged on the outflow side of the medium flow in the flow channel 5, in particular downstream of the last battery cell through which the medium 6 flows. The temperature sensors 7 and 8 can include other functions, such as measuring the volume flow of the medium. If necessary, a separate sensor can also be provided, in particular in the flow channel, for measuring the volume flow.

[0052] The cell current of the battery cell 2, which characterizes the operating node of the energy storage device, can be supplied to the control and / or regulating device 10. Likewise, the acquired measured values ​​of the temperature sensors 7 and 8 and, if necessary, the measured values ​​of other existing sensors can be supplied to the control and / or regulating device 10.

[0053] The control and / or regulating device 10 has a machine-readable program code 11 which allows control intervention in a device for regulating the volume flow 9 of the heat exchange medium 6 (e.g. the volume flow of a pump). For this purpose, the program code 11 is designed to regulate the volume flow of the medium 6 in such a way that the temperature difference between the first battery cell in the flow direction and the last battery cell in the flow direction is reduced or minimized. This can be done by control or by regulation. The program code 11 is stored in a non-volatile memory of the control and / or regulating device 10.

[0054] Furthermore, the program code 11 can be transferred to the control and / or regulating device 10 via a server or by means of a non-volatile storage medium.

[0055] Preferably, both for control and regulation, the actual volume flow of the medium 6 is detected by means of sensors. In the case of control, this actual volume flow is used to verify the volume flow prevailing in the flow channel 5 that is regulated. In addition to the corresponding known conditions for the battery cells, for example, in addition to the measured data of the battery cell current or the temperature measurement of the battery cell 2 obtained therefrom, the measured data, in particular the temperature measurement value of the heat exchange medium 6, are used to realize the control intervention of the pump 9. It is not necessary to measure the battery cell current, which can be known empirically from the given power output of the battery cell 2.

[0056] According to the actual operating node of the battery cell 2, the optimal volume flow for minimizing the temperature difference or minimizing the temperature difference is determined according to the known characteristic curve family arranged for the battery cell to be controlled. This optimal volume flow is adjusted by the control device 10 with the aid of the pump 9. The adjustment of the volume flow can be re-verified by a volume flow sensor.

[0057] Since the operating point of the battery cell 2 can change rapidly in a short time according to the required or consumed power, continuous monitoring of the medium temperature and the battery cell charge level and corresponding regulation of the volume flow (for example through process regulation or process control) are preferably achieved.

[0058] In addition, the temperature of at least the first and last battery cell 2 flowing through can also be detected or acquired in the flow direction S, and the volume flow can be regulated according to the temperature difference with the help of the control and / or regulation device 10 so that the temperature difference between the battery cells 2 is minimized at the existing working nodes of the battery cells 2.

[0059] Figure 2 Shown by the attached Figure 1 90° rotated view of the schematically shown energy storage heat exchange system. Figure 2 In, then Figure 2 The reference numerals in Figure 1 The corresponding reference numerals in FIG. Figure 2 and Figure 1 As can be seen in combination, the heat exchange medium 6 flows along the outer shell surface of the battery cell 2, but the end faces of the battery cell 2 are usually not circulated by the heat exchange medium 6 and are therefore available for sensors and can be used for energy output and / or input of the battery cell 2.

[0060] Figure 3 shows the Figure 1 and attached Figure 2 Flowchart of a method for an energy storage heat exchanger. The flow chart assumes that the energy storage heat exchanger is in operation and that energy is output from the battery cells 2. As a result, the battery cells heat up. The battery cells are cooled by means of a cooling medium, as described in the attached Figure 1 and attached Figure 2 A heat exchange medium, in particular a cooling medium, circulates around the battery cells.

[0061] In a first method step S1 measuring the temperature, a first and a second temperature of the cooling medium are detected. The first temperature is measured upstream of the first battery cell and the second temperature is measured downstream of the last battery cell. These temperature values ​​are fed to the control and / or regulating device 10 .

[0062] In the second method step S2, determining the operating node, the actually existing operating node of the battery cell is tested and the conditions characterizing the operating node are transmitted to the control and / or regulating device. If necessary, such a test of the operating node is carried out by the control and / or regulating device itself, in that the control and / or regulating device interacts with the engine control or other control and retrieves the corresponding data or power parameters.

[0063] In the third method step S3 check, the control and / or regulating device checks whether the volume flow is adapted to the existing parameters in the form of the working nodes of the cooling medium and the cooling medium temperature based on the characteristic curve family stored in the memory. The characteristic curve family presets the optimal values ​​for the volume flow for the corresponding parameters. If the volume flow actually adjusted for the cooling medium deviates from the volume flow that results in the minimum temperature difference between the first and last battery cells in the flow direction under the existing parameters, a control intervention is performed. In this case, the Y path of the flowchart is executed. If the adjusted volume flow is consistent with the value of the volume flow, at least within the preset tolerance range provided by the characteristic curve family for the preset parameters, no control intervention is performed. In this case, further continuous monitoring is performed until control intervention is required. This executes the N path of the flowchart.

[0064] In a fourth method step S4 control, the control and / or regulating device controls the device for regulating the volume flow in such a way that the volume flow is increased or reduced to a volume flow predefined, for example, by a characteristic diagram. This then leads to a reduction in the temperature difference between the first and last battery cell in the flow direction and thus overall a reduction or minimization of the temperature difference between the first and last battery cell.

[0065] In an optional fifth method step S5 verification, the control and / or regulating device verifies whether the value of the volume flow obtained from the characteristic diagram corresponds to the value actually present in the flow channel after the control intervention. If so, the operating node and the medium temperature are monitored continuously until the next control intervention. Otherwise, another control intervention is carried out until a desired value of the volume flow is obtained in the cooling flow channel, which desired value can be changed by a change in the medium temperature and / or a change in the operating node. Therefore, the volume flow regulation based on the theoretical value of the modified volume flow has priority over the tracking of the actual volume flow as an "outdated" value for the theoretical volume flow due to the changed medium temperature and / or the changed operating node.

[0066] Since the above detailed description of the device and method is about embodiments, a person skilled in the art can modify it in a wide range in a usual way without departing from the technical field of the present invention. In particular, the mechanical arrangement and size ratios of the individual components to each other are only exemplary.

[0067] Reference numerals list

[0068] 1 Energy storage heat exchange system

[0069] 2 Battery Cells

[0070] 3 Battery cell housing

[0071] 4 Heat exchange surface

[0072] 5 Flow channel

[0073] 6 Heat exchange medium

[0074] 7. First temperature sensor

[0075] 8 Second temperature sensor

[0076] 9 Devices for regulating volume flow, pumps

[0077] 10 Control and / or regulating devices

[0078] 11 Machine-readable program code

[0079] S Flow direction

[0080] S1 Temperature measurement method steps

[0081] S2 Methods and steps for determining working nodes

[0082] S3 Method steps to check actual status

[0083] S4 Method step for controlling a device for regulating a volume flow

[0084] S5 Verification and Adjustment Methods and Steps

Claims

1. A method for operating a heat exchanger for an energy storage device comprising a plurality of electrochemical cells, wherein: The battery cells are circulated one after another by a heat exchange medium in a flow direction to achieve heat exchange, wherein the battery cells respectively have a heat exchange surface, and heat exchange is mainly carried out between the heat exchange medium and the corresponding battery cells through the heat exchange surface, wherein a first battery cell in the flow direction exchanges heat with the heat exchange medium through a first heat exchange surface, and a second battery cell located downstream of the first battery cell exchanges heat with the aid of a second heat exchange surface that is larger in size than the first heat exchange surface, wherein the volume flow rate of the heat exchange medium is adjusted so that for a selected working node of the battery cells, the temperature difference between the temperature of the first battery cell and the temperature of the second battery cell is reduced.

2. The method according to claim 1, in, The first battery cell in the flow direction is used as the first battery cell and the last battery cell in the flow direction is used as the second battery cell.

3. The method according to claim 1 or 2, in, A first temperature of the heat exchange medium is collected at a first position, and a second temperature is collected at a second position located downstream, and the volume flow is adjusted according to conditions provided by the determined working node so that the temperature difference of the battery cells is reduced.

4. The method according to claim 3, in, The condition provided by the determined operating node is the provided battery cell current.

5. The method according to claim 1 or 2, in, A first temperature of a first battery cell in the flow direction and a second temperature of a second battery cell located downstream are detected, wherein the volume flow is regulated such that a difference between the first temperature and the second temperature is reduced.

6. The method according to claim 1 or 2, in, The volume flow is controlled and / or regulated.

7. An energy storage device heat exchange system with an energy storage device, the energy storage device comprising a plurality of electrochemical cells for providing electrical energy, the energy storage device heat exchange system comprising: A flow channel for a flow of a heat exchange medium through the battery cell in a flow direction, wherein: The battery cells are arranged one after the other in a flow direction, wherein the battery cells each have a heat exchange surface, the heat exchange medium flows around the heat exchange surface, and heat can be exchanged between the heat exchange medium and the battery cells through the heat exchange surface, wherein a first battery cell in the flow direction has a first heat exchange surface, wherein a second battery cell located downstream of the first battery cell has a second heat exchange surface, wherein the second heat exchange surface is larger than the first heat exchange surface; A control and / or regulating device and a device for regulating a volume flow, wherein the control and / or regulating device is operatively connected to the device for regulating a volume flow, so that the volume flow can be controlled and / or regulated by means of the control and / or regulating device.

8. The energy storage heat exchange system according to claim 7, in, The control and / or regulating device is operatively connected to a device for volume flow control, so that a temperature difference between a first temperature of the first battery cell and a second temperature of the second battery cell can be reduced by the control and / or regulating device.

9. The energy storage heat exchange system according to claim 7, in, A first sensor for collecting the temperature of the heat exchange medium is provided at a first position in the flow channel, and at least one second sensor for collecting the temperature of the heat exchange medium is provided at a second position downstream of the first position, wherein the temperatures collected by the first and at least the second sensor can be supplied to the control and / or regulating device.

10. The energy storage heat exchange system according to claim 7 or 9, in, The heat exchange medium is fed into a flow circuit which is uncoupled from a heat exchange circuit for conditioning the vehicle interior or the engine.

11. The energy storage heat exchange system according to claim 7, in, The control and / or regulating device regulates the energy storage heat exchange system according to the method according to any one of claims 1 to 5 .

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