Cooling arrangement for an energy storage device of a motor vehicle and method for cooling an energy storage device

Abstract

The invention relates to a cooling arrangement (10) for cooling an energy storage device (14), which has a first cooling circuit (16) for cooling the energy storage device (14), wherein a coolant is circulating in the first cooling circuit (16), and the first cooling circuit (16) comprises at least one first pump by means of which the coolant can be conveyed through the first cooling circuit (16). The cooling arrangement (10) further comprises a second cooling circuit (18) for cooling the energy storage device (14), wherein a coolant is circulating in the second cooling circuit (18), and wherein the second cooling circuit (18) comprises a second pump (50) by means of which the coolant can be conveyed through the second cooling circuit (18) when the first cooling circuit (16) is at least partially in an inactive and / or defective state.

Description

The invention relates to a cooling arrangement for cooling an energy store, wherein the cooling arrangement has a first cooling circuit for cooling the energy store, in which a coolant can be circulated, and wherein the first cooling circuit comprises at least one first pump, by means of which the coolant can be conveyed through the first cooling circuit. Furthermore, the invention also relates to a method for cooling an energy store.Energy stores such as, for example, motor vehicle batteries, in particular high-voltage batteries, are typically cooled by a cooling system. In this case, above all, cooling plate concepts are used. The battery modules or battery cells of such a battery can be arranged accordingly on such a cooling plate which comprises integrated cooling ducts through which a coolant can flow for the purpose of cooling the battery. Such a coolant is typically conveyed by a coolant pump. The coolant which has passed through the cooling plate and has thereby been heated, for example, can be cooled via a heat exchanger, which can be thermally coupled to a refrigeration circuit of the motor vehicle, for example, and fed back to the cooling plate. The refrigeration circuit of such a motor vehicle, which can also be referred to as an AC (Air Conditioning) system, can comprise, for example, an electric air conditioning compressor in order to cool the refrigerant. This is typically a high-voltage component, that is to say part of a high-voltage on-board power supply system of such a motor vehicle, which comprises the high-voltage battery to be cooled. If, for example, a thermal runaway occurs, it would be advantageous to cool such a battery cell as much as possible in order to restrict the propagation of this thermal runaway or to prevent the progress of the thermal runaway and transfer to, for example, adjacent cells. The cooling capacity that can be provided by a conventional cooling circuit is often not sufficient for this, however. A further complication is that the high-voltage on-board power supply is often deactivated in the event of such a defect, the electric air conditioning compressor can no longer be operated accordingly, and active cooling of the cooling circuit can accordingly also no longer take place.DE 10 2020 127 572 A1 describes a method for cooling an electrical energy store of a motor vehicle, which store has at least one storage cell designed for storing electrical energy and comprises a cell housing, in which, as a result of a thermal event of the storage cell, a gas is discharged from the cell housing via a degassing opening of the cell housing which is released as a result of the thermal event. As a result of the thermal event, a coolant exits a cooling element through which the coolant can flow and is introduced into the cell housing via the degassing opening. The coolant is introduced into the cell housing at a volume flow and at a pressure.As a result, cooling of the relevant battery cell by flooding it can only take place when it has already outgassed and therefore the cell degassing opening is open. Proactive cooling of adjacent cells is not possible by this method, for example, so that the propagation of such a thermal runaway and the access to adjacent cells can only be inhibited to a limited extent.DE 10 2019 007 809 A1 describes an electrical storage device having a receiving space, a storage cell accommodated in the receiving space, having a contacting device and a cell housing which is provided with a venting element for discharging gas from the cell housing, and having a sealing device by means of which the receiving space is divided into a venting region and a contacting region sealed counter to the venting region. In this case, the receiving space is also divided by means of the sealing device into all cooling regions sealed against the contacting region and against the venting region, in which cooling regions at least a partial region of the storage cell is arranged. By means of a cooling device, a coolant can be introduced into the cooling region, by means of which coolant the storage cell around which the coolant can flow directly on the outer circumference is to be cooled. As a result, a direct cooling of the storage cells can be provided.However, in the case of thermal runaway of a memory cell, the problems described above remain.It is an object of the present invention to provide a cooling arrangement and a method which allow cooling of an energy store that is as effective as possible, in particular also in the case of a thermal runaway of a storage cell of the energy store.This object is achieved by a cooling arrangement and a method having the features according to the respective independent claims. Advantageous embodiments of the invention are the subject matter of the dependent patent claims, the description and the figures.The cooling arrangement according to the invention for cooling an energy store comprises a first cooling circuit for cooling the energy store, in which a coolant can be circulated, wherein the first cooling circuit comprises at least one first pump, by means of which the coolant can be conveyed through the first cooling circuit. In addition, the cooling arrangement comprises a second cooling circuit for cooling the energy store, wherein a coolant can be circulated in the second cooling circuit and wherein the second cooling circuit has a second pump, by means of which the coolant can be conveyed through the second cooling circuit when the first cooling circuit is at least partially in an inactive and / or defective state.The energy store can thus advantageously also be cooled by means of the second cooling circuit in the event of a defect or inactive state of the first cooling circuit. The second cooling circuit can thus function as an emergency cooling system. If the first cooling circuit is not in an inactive or defective state, there is advantageously the further option of nevertheless operating the second cooling circuit and, for example, additionally supporting the cooling of the energy store. If, for example, a thermal runaway of a storage cell of the energy store occurs and as a result, for example when the high-voltage on-board power supply system is switched off, no cooling power or only a reduced cooling power can be provided by the first cooling circuit, the second cooling circuit can cool the energy store additionally or alternatively to the first cooling circuit. It is thus advantageously possible to provide a certain cooling capacity for cooling the energy store even in the event of a fault, which cooling capacity is increased compared to a cooling capacity which could be provided to the maximum in such a fault without the operation of the second cooling circuit or without the second cooling circuit. By providing the second cooling circuit, it is thus possible on the one hand to increase the cooling capacity both during normal operation or to support the operation of the first cooling circuit, that is to say to provide supplementary or alternative emergency cooling even in the event of a fault. This allows particularly effective cooling of the energy store, in particular, even in the event of a fault.Optionally, the coolant which can be circulated in the first cooling circuit can likewise be part of the cooling arrangement and / or the coolant which can be circulated in the second cooling circuit can likewise be part of the cooling arrangement. In this case, the coolant circulating in the first cooling circuit may also be referred to as a first coolant, and the coolant circulating in the second cooling circuit may be referred to as a second coolant. These need not necessarily be different cooling means, but can also be the same cooling means. According to one possible configuration, the first cooling circuit and the second cooling circuit can be permanently fluidically separated from one another. This means that the coolant which is located in the first cooling circuit cannot pass into the second cooling circuit and vice versa. The two cooling circuits are thus completely fluidically decoupled from one another. According to a further embodiment, however, it is also conceivable and in particular preferred for the two cooling circuits also to be able to be fluidically coupled to one another. The coolant which passes through the first cooling circuit can then, at least temporarily, also pass into the second cooling circuit and vice versa. In this case, it is preferable that the first and second refrigerants be the same refrigerant, for example, a water-based refrigerant, for example, water with additives, or a cooling oil or the like in both cases. Otherwise, the coupling of the two cooling circuits would result in a thorough mixing of the various cooling agents. A respective cooling circuit can thereby define at least one flow path along which the coolant flows when it runs through the respective cooling circuit or is circulated therein. The flow direction can be predefined, for example, by the at least one pump assigned to the respective cooling circuit and the pumping direction thereof. In this case, each of the cooling circuits is assigned at least one such pump, wherein the pump assigned to the first cooling circuit is referred to in the present case as a first pump and the pump assigned to the second cooling circuit is referred to as a second pump. The pumps can be identical or different in terms of their design. By providing a respective pump, the coolant can be circulated in the first cooling circuit even if the second cooling circuit is not currently active and, for example, its pump is deactivated, and vice versa. The respective pumps are preferably supplied during operation with energy from a low-voltage on-board power supply system of the motor vehicle, in which the cooling arrangement is preferably used. The pumps can therefore generally also be operated if, for example, the high-voltage on-board power supply of such a motor vehicle is deactivated or defective or the like.It is also conceivable that at least a part of the second cooling circuit is provided outside the motor vehicle, for example by a charging station having an integrated cooling functionality. In this case, the second pump can also optionally be part of such a charging station or generally represent a pump external to the motor vehicle. For example, the motor vehicle, which comprises the first cooling circuit, the energy store and a part of the second cooling circuit, can additionally be coupled to the vehicle-external part of the second cooling circuit, which is provided by the charging station, during charging, in order to provide emergency cooling via the charging station, for example, in the event of an emergency. In an emergency, the charging station can correspondingly pump coolant through the second cooling circuit in order to cool the energy store. Thus, the operation of the second cooling circuit is independent of the functionality of the motor vehicle and its components. Emergency cooling can thus be provided at any time.However, it is preferred that the second cooling circuit completely represents an internal cooling circuit of the motor vehicle and the second pump thus also represents an internal pump of the motor vehicle. An emergency cooling function can thus be provided at any time, regardless of whether or not such a motor vehicle is currently connected to a charging station. In addition, the second cooling circuit can also be used advantageously in normal operating situations in which there is no fault, in particular also during travel, as will be explained in more detail later.The respective cooling circuits can comprise coolant lines for guiding the coolant. These can be designed, for example, as tubes and / or hoses. In addition, the cooling arrangement can also comprise at least one coolant compensation container. For this purpose, a common coolant compensation container can be provided for the first and second cooling circuits, or a separate coolant compensation container can be provided for each of the first and second cooling circuits. In addition, the coolant circuits can each also have numerous further components which are not explicitly mentioned in the present case. The coolant, in particular the first and / or second coolant, can also be an electrically non-conductive coolant. As a result, the safety can be increased even further, especially with regard to a possible thermal runaway of a battery cell. Even a leak in the cooling system, which causes the coolant to penetrate into the energy store, for example, then does not necessarily lead to a short circuit and / or generally to a defect in the energy store.Optionally, the energy store can also be part of the cooling arrangement. The energy store is preferably designed as a battery, for example as a high-voltage battery, in particular for a motor vehicle. The energy store can have, for example, a plurality of energy storage modules which in turn each comprise a plurality of energy storage cells, for example battery cells. These battery cells can be configured, for example, as lithium-ion cells. In general, the energy store comprises at least one energy storage cell.The first cooling circuit is preferably in the inactive and / or defective state here if a cooling circuit to which the first cooling circuit is thermally coupled or couplable is inactive and / or no heat can be transferred from the first cooling circuit to the cooling circuit and / or the first pump is inactive and / or the first cooling circuit has a leak.The cooling arrangement may comprise a measuring device or detection device configured to detect one or more such particular inactive and / or defective states. In addition, as explained in more detail below, the cooling arrangement can have a control device in order to activate and / or control or operate the second cooling circuit as a function of the detection of such a specific inactive and / or defective state.The refrigeration circuit can optionally also be part of the cooling arrangement. However, this does not necessarily have to be the case. The first cooling circuit can be coupled or couplable to the cooling circuit, for example, via a first heat exchanger, as explained in more detail below. If, as described at the beginning, the high-voltage on-board power supply system, and also an electric air-conditioning compressor or another device of the refrigeration circuit, for example, fails, it may be the case that the refrigeration circuit can no longer be cooled properly via the refrigeration circuit. In other words, heat can then either no longer be transferred from the first cooling circuit to the cooling circuit or can only be transferred to a reduced extent. This can be determined, for example, by means of a temperature sensor of the first cooling circuit. If the coolant temperature of the coolant flowing through the first cooling circuit is unexpectedly high, for example higher than a predetermined limit value, this situation can be classified as a defective state of the first cooling circuit or can be detected as such a defective state. However, the reason for this can also be entirely outside the first cooling circuit, such as in the cooling circuit. A further possible defective state can relate, for example, to the first pump. If, for example, the energy supply of the first pump fails, coolant can no longer be conveyed through the first cooling circuit. The first pump may also be otherwise defective, for example having a mechanical defect, or the like. This can also be detected and evaluated as a defective state. A further defective state can also be a leak in the first cooling circuit. Such a leak allows the coolant to leak out of the first cooling circuit. This can also be detected, for example by the coolant compensation container dropping below a specific fill level limit value, and / or by a specific pressure drop of the refrigerant pressure in the first cooling circuit being detected, or the like. Many of these defective states may result in inactivity of the first cooling circuit. In general, an inactive state of the cooling circuit can thus be understood to mean that the cooling circuit can no longer provide cooling power for cooling the energy store or can only provide it to a reduced extent compared to a specific cooling power requirement and / or a specific normal operating situation. In all these situations, the second cooling circuit can thus be used to cool the energy store. However, the second cooling circuit is not limited to being used only in situations in which an inactive and / or defective state of the first cooling circuit is at least partially present, which can nevertheless be the case. It can thus be provided either that the coolant is conveyed through the second cooling circuit by means of the second pump of the second cooling circuit only when the first cooling circuit is at least partially in an inactive and / or defective state of one or more defined states of this kind, or it can be provided that coolant can also be conveyed through the second cooling circuit by means of the second pump when the first cooling circuit is not in such an inactive and / or defective state.According to a further advantageous embodiment of the invention, the first cooling circuit comprises a first heat exchanger for transferring heat from the first cooling circuit to a first heat sink, in particular wherein the first cooling circuit is thermally coupled or couplable to a cooling circuit via the first heat exchanger. Alternatively or additionally, the second cooling circuit can comprise a second heat exchanger for transferring heat from the second cooling circuit to a second heat sink, in particular wherein the second cooling circuit can be coupled or is coupled to an environment via the second heat exchanger.The first cooling circuit can be coupled or coupled at least thermally to a conventional cooling circuit, for example, via the first heat exchanger. By means of this thermal coupling, the first cooling circuit can be cooled by means of the cooling circuit, that is to say heat can be transferred from the first cooling circuit to the cooling circuit. It is also conceivable that the second cooling circuit can also be or is thermally coupled to such a cooling circuit, in particular to the same cooling circuit, by means of its second heat exchanger. In particular, such a coupling of the second cooling circuit to the cooling circuit can be fluidic. Thus, for example, to activate the emergency cooling, the refrigerant circulated in the refrigeration circuit, for example CO2, can be introduced into the second cooling circuit via this coupling. However, it is particularly advantageous if the second cooling circuit is not coupled or can be coupled to the cooling circuit via the second heat exchanger, but instead to an environment, in particular the cooling arrangement and / or the motor vehicle, which comprises the cooling arrangement. The second heat exchanger can be designed accordingly as an ambient heat exchanger. The cooling of the second cooling circuit via the second heat exchanger can be designed, for example, as air cooling. For this purpose, the cooling arrangement can also comprise a fan and / or a fan in order to generate an air flow in the region of the second heat exchanger in a targeted manner in order to promote the heat transfer from the second heat exchanger to the environment. This is particularly advantageous since, for example, in the event of a failure of the high-voltage on-board power supply system and of the cooling functionality of the refrigeration circuit, an additional cooling option, in particular passive cooling option, or at least cooling option not bound to the functionality of the high-voltage on-board power supply system is provided by the second cooling circuit. In addition, this enables particularly energy-efficient operation of the second cooling circuit. This allows cooling even when no or only little energy is available for operating the second cooling circuit. Although in such a case, it is not possible to achieve any particularly high cooling capacities alone by the second cooling circuit, in particular in comparison with the cooling capacities which can be achieved by the first cooling circuit and which is coupled or can be coupled to the cooling circuit, the second cooling circuit can also be operated, for example, in addition to the first cooling circuit, in order, for example, to precool the coolant before it is further cooled by the first cooling circuit or the first heat exchanger. As a result, more energy-efficient operation of the first cooling circuit is possible and energy can be saved. In addition, this also makes it possible to provide a type of boost cooling system in order to be able to achieve even higher cooling capacities in total by the combined operation of the two cooling circuits.However, particularly with regard to such a combined operation, which is in principle also possible when both cooling circuits are operated permanently in a fluidically separated manner from one another, significantly more efficient operating modes can be made possible if a coupling possibility is provided between the two cooling circuits. Accordingly, a further very advantageous embodiment of the invention is provided if the cooling arrangement comprises a valve arrangement comprising at least one valve, by means of which the first and the second cooling circuit can be fluidically coupled at at least one point and can be fluidically separated, and in particular by coupling the first and the second cooling circuit from at least part of the first cooling circuit and at least part of the second cooling circuit an overall circuit can be formed, in which a coolant can be circulated. With respect to the above-mentioned first and second coolant, this coolant can now be composed proportionally of the first and second coolant or of fractions of the first and second coolant. The first cooling circuit and the second cooling circuit can thus advantageously be connected to form an overall circuit by means of the valve arrangement. Such an overall circuit can comprise a plurality of circuit branches. For example, at least one flow path can be assigned to such an overall circuit, in particular a closed flow path, along which the coolant can be flowed when the coolant is circulated in the overall circuit. However, such an overall circuit can also comprise a plurality of, for example branching and / or merging, circuit branches and correspondingly provide a plurality of flow paths along which the coolant which is circulated through the overall circuit can flow. It is precisely by virtue of such interconnection of the two cooling circuits that it is advantageously possible for the second cooling circuit to provide a supporting effect for the first cooling circuit and / or a boost function, that is to say an overall increased cooling capacity. In the event of an emergency or in the event of a defect, the two cooling circuits can advantageously be decoupled again via the valve arrangement and, for example, only the second cooling circuit can be operated or the second cooling circuit can be operated independently and decoupled from the first cooling circuit. This allows a particularly high level of flexibility and a particularly good situation adaptation. In addition, the valve arrangement can not only provide two switching states, at least one of which is assigned to the decoupled state between the first and second cooling circuits and a second state represents a coupled state, but, for example, it is possible within the coupled state to define further different substates and to implement them by suitable switching states of the valve arrangement in order to provide different functions and, for example, different cooling properties.The valve arrangement can generally comprise not only one valve but also a plurality of valves. These can be arranged distributed in the first and / or second cooling circuit and / or in at least one additional line of the cooling arrangement, depending on the configuration of the valve arrangement. The valves of the valve arrangement can be designed to be actuatable, for example by a control device, or can also be passively switchable, for example depending on the coolant pressure. The valve arrangement can also comprise both controllable valves and passively switchable valves. Preferably, at least a part of the valve arrangement and thus at least one valve of the valve arrangement is designed to be actuatable. This makes it possible, for example, to control the valve arrangement, more precisely the actuatable part of the valve arrangement, depending on a situation parameter, for example. These situation parameters can be, for example, the detection of one of the above-mentioned inactive and / or defective states or specify the presence of such a state, and / or relate to a temperature, for example a temperature of the energy store and / or of the coolant, in particular of the coolant in the first and / or second cooling circuit, an ambient temperature, and so forth.If the first and the second cooling circuit are interconnected to form the overall circuit, it is not necessarily necessary for each part of the first and / or second cooling circuit, which is flowed through in a separated operation, to be flowed through when the coolant is circulated in the overall circuit. In other words, the overall circuit can also be formed only by a part of the first cooling circuit which is different from the entirety of the first cooling circuit and / or a part of the second cooling circuit which is different from the entirety of the second cooling circuit. In addition, the cooling arrangement can comprise further additional components, in particular at least one additional line, for example a bypass line or the like, through which the coolant does not flow in the case of operation of the first and / or second cooling circuit which is separated from one another, but through which the coolant flows in the case of combined operation, that is to say when the coolant flows through the overall circuit. Such auxiliary lines may be, for example, connecting lines in order to establish a fluidic connection between the first cooling circuit and the second cooling circuit or the corresponding parts thereof. The at least one additional line can also be designed very short, and be limited, for example, to a coupling point or coupling region which connects two lines of the first and second cooling circuit to one another, e.g., via a valve. The above-mentioned valves of the valve arrangement can then be positioned accordingly not only in the first cooling circuit and / or in the second cooling circuit, but alternatively or additionally also in such additional lines. In particular, in this case the at least one valve of the valve arrangement does not necessarily have to be arranged in the first or second cooling circuit, but can be provided exclusively in such an at least one additional line.In a further advantageous embodiment of the invention, a cooling device is assigned to the energy store. This can be designed, for example, as a cooling plate with integrated cooling channels. The cooling device can also be designed as a space through which flow can take place, with walls in order to delimit this space. This space can also represent a part of an interior space or receiving space of a battery housing for receiving energy storage cells of the energy store. In other words, direct cooling can also be implemented by the cooling device, according to which direct cooling the coolant flowing through the cooling device can be brought into direct contact with the energy storage cells, at least a part of the energy storage cells, for example a part of the energy storage cells which is not carrying voltage. Preferably, however, the cooling device is designed as an indirect cooling device. In other words, the coolant flowing through the cooling device should not be able to come into direct contact with the energy storage cells of the energy storage device. The space provided by the cooling device through which the coolant can flow, or by cooling channels, are spatially completely separated from the receiving space of the energy store in which the energy store cells are received.In addition, it is very advantageous if the cooling device of the energy store has a first coolant inlet and a second coolant inlet, as well as a first coolant outlet and a second coolant outlet, and also a first coolant path as part of the first cooling circuit, wherein the first coolant path fluidically connects the first coolant inlet and the first coolant outlet to one another, and a second coolant path as part of the second cooling circuit, wherein the second coolant path fluidically connects the second coolant inlet and the second coolant outlet to one another. The first and the second coolant inlet can thereby represent inlets of the cooling device which are separated from one another. In this case, for example, a first feed line comprised by the first cooling circuit can be coupled to the first coolant inlet and a second coolant feed line of the second cooling circuit can be coupled to the second coolant inlet. The same applies to the coolant outlets. These too can be coupled in each case to a discharge line, one of which is assigned to the first cooling circuit and one of which is assigned to the second cooling circuit. The coolant inlets and / or coolant outlets can, however, also represent a common coolant inlet and / or a common coolant outlet. The coolant flowing through the first cooling circuit can be supplied to the cooling device via the same inlet as the coolant flowing through the second cooling circuit. The same applies again to the outputs. If the first cooling circuit and the second cooling circuit are to be separated from one another, this can best be achieved by separate coolant inlets and separate coolant outlets.According to a first exemplary embodiment, the first coolant path and the second coolant path are fluidically coupled or couplable. In this case, the first and second coolant are mixed within the cooling device when the first and second coolant paths are fluidically coupled to one another. In other words, there is a fluidic connection between the different cooling channels and the cooling channels assigned to the respective cooling circuits within the cooling device. Thus, the first coolant may enter the second cooling circuit and vice versa. This fluidic coupling can be implemented in principle at any point of the two coolant paths. For example, a coupling can be realized by a common coolant inlet or also a common coolant outlet, as already described above. However, separate inlets and outlets for the coolant can nevertheless be provided, that is to say two separate inlets and two outlets separated from one another, and the fluidic coupling can be implemented at one or more points of the coolant path between the respective inlet and outlet.Such a coupling possibility or coupled configuration of the cooling device has the advantage that this allows the cooling agents flowing through the respective cooling circuits to be mixed within the cooling device. In general, the coolant supplied to the cooling device via the respective separate coolant inlets can be mixed within the cooling device before the cooling device is discharged again via the respective outlets. By such a mixing, a more homogeneous temperature distribution can be achieved. This allows, for example, a particularly uniform cooling of the energy store. On the other hand, by completely separating the two coolant paths, different coolant temperatures of the coolant supplied via the respective inputs can also be used in a targeted manner in order to cool specific regions of the energy store more strongly than other, for example typical hotspot regions of the energy store more strongly than other regions of the energy store which typically do not heat up as strongly.Accordingly, a further advantageous embodiment of the invention is provided if the first coolant path and the second coolant path are fluidically separated from one another. Accordingly, in this case, the cooling device is designed such that it has at least one first cooling duct which is assigned to the first cooling circuit and which connects the first coolant inlet to the first coolant outlet. In addition, the cooling device then comprises a second cooling channel which connects the second coolant inlet and the second coolant outlet to one another, wherein the first cooling channel and the second cooling channel are completely separated from one another in terms of fluid and space. Coolant which is supplied to the cooling device via the first coolant inlet cannot thus enter the second coolant channel and vice versa. Mixing within the cooling device is therefore not possible. The cooling device can thus be configured such that the two coolant paths, i.e. the first and the second coolant path, are permanently fluidically separated from one another and accordingly cannot be coupled within the cooling device.According to the above-described configuration, according to which the two coolant paths are coupled or couplable, this can in turn be implemented, on the one hand, in such a way that the cooling device is configured such that this fluidic coupling between the two coolant paths exists permanently or, according to a further variant, such that it can be produced as required by a valve or the like, for example. In other words, the cooling device can also have a device by means of which the two coolant paths can be fluidically coupled to one another within the cooling device and / or can be fluidically separated from one another.Advantageous design possibilities of the overall circuit are described below. In this case, according to an advantageous embodiment of the invention, it can be provided that the overall circuit which can be formed by means of the valve arrangement is designed in such a way that the coolant can flow through the first heat exchanger and the second heat exchanger in series when the coolant circulates in the overall circuit. In this case, the first heat exchanger and the second heat exchanger can be connected to one another in series, i.e. in series. The above-described cooling device of the energy store can then likewise be located in series with the first heat exchanger and / or second heat exchanger. To name a simple example, the first heat exchanger can, for example, first be flowed through by the coolant, then by the second heat exchanger, and then the coolant can be supplied to the cooling device and then in turn supplied to the first heat exchanger, and so on. However, significantly more complex flow paths can also be realized. For example, the energy store or its associated cooling device can be flowed through multiple times per flow cycle, while the first and second heat exchangers are each flowed through only once or at least less often than the cooling device. According to such a serial circuit, different flow paths can be realized in turn. In this case, it constitutes a further advantageous embodiment of the invention if a first flow path is provided by the overall circuit, according to which flow path the first heat exchanger is arranged between the cooling device and the second heat exchanger in the flow direction. If the coolant therefore flows through the overall circuit, it flows, for example, first through the second heat exchanger, then through the first heat exchanger, then through the cooling device of the energy store, then again through the second heat exchanger, and so on. This is particularly advantageous if precooling of the coolant is to take place by the second heat exchanger before it is provided to the first heat exchanger in order to cool this coolant still further before it is finally supplied to the cooling device of the energy store. As a result, particularly high cooling capacities can be achieved or the coolant can be cooled particularly efficiently in terms of energy to very low coolant temperatures. The coolant which leaves the cooling device of the energy store, the typical operating temperature of which can be situated, for example, in a range between 30° C. and 60° C., typically leaves this cooling device at a correspondingly high temperature which, in very many situations, is higher than the ambient temperature of the motor vehicle or of the cooling arrangement. In the majority of cases, therefore, even if the second heat exchanger is designed as an ambient heat exchanger, particularly effective cooling of the coolant emerging from the cooling device can be provided without having to use much or even any additional energy for this purpose, since the heat can be dissipated to the environment in a simple manner. Further cooling can then take place by the first heat exchanger.According to a further advantageous embodiment of the invention, a second flow path is provided by the overall circuit, according to which the second heat exchanger is arranged between the cooling device and the first heat exchanger in the flow direction. In this case, the coolant therefore flows first through the first heat exchanger, then through the second heat exchanger, and is then first supplied to the cooling device and, after passing through it, is again supplied to the first heat exchanger, and so on. This configuration is advantageous, for example, when the ambient temperature is very low. In the case of minus degrees in winter, for example, very efficient cooling of the coolant can thus already be provided by the second heat exchanger designed as an ambient heat exchanger. The cooling capacity, which must be provided via the first cooling circuit or the first heat exchanger, can thus be kept extremely low. Thus, for example, the first heat exchanger can be used with low energy expenditure in order to achieve precooling of the coolant, wherein an even greater cooling of the coolant can then be achieved when passing through the second heat exchanger. This also allows a particularly high cooling capacity to be provided overall, and this in a particularly energy-saving manner. The two described variants according to the first and the second flow path can also be combined with one another. The valve arrangement can be configured such that the first flow path can be implemented in a first situation and the second flow path can be implemented in a second situation. For example, the control device for controlling at least a part of the valve arrangement can be designed to carry out the control depending on a current ambient temperature in order to implement the first flow path or the second flow path depending on this ambient temperature.According to a further advantageous embodiment of the invention, a third flow path is provided by the overall circuit, according to which flow path the coolant which has passed through the first heat exchanger first flows through the cooling device, then through the second heat exchanger, then again through the cooling device before it is fed back to the first heat exchanger, and so on. The coolant which leaves the cooling device can first be cooled slightly when passing through the second heat exchanger and then pass through the cooling device again. During the second pass, the coolant has been heated to a greater extent overall and accordingly has a higher starting temperature than, for example, after the first pass. After the second pass, the coolant can be supplied correspondingly to the first heat exchanger in order to cool it significantly more strongly and then it can be supplied again to the cooling device. The second heat exchanger can thus be used as energy-efficient intermediate cooling. This also saves the first cooling circuit in terms of energy.This third flow path can also be implemented either alternatively to the two above-mentioned flow paths or additionally combined with at least one or both of the above-mentioned flow paths. This can be accomplished in a simple manner by suitable design of the valve arrangement and its actuation.In a further advantageous embodiment of the invention, the overall circuit has at least one branching point at which, when the coolant circulates in the overall circuit, a first part of the coolant can be fed to the first heat exchanger and a second part of the coolant can be fed to the second heat exchanger, in particular during or after passing through the cooling device. Such a branching point thus allows a type of parallel flow through the first and second heat exchanger to be realized. In this way, a plurality of different flow paths can be simultaneously implemented through the entire circuit. This branching point can in principle be provided at any point of the overall circuit. For example, such a branching point can be implemented by the above-described fluidic coupling of the two flow paths within the cooling device of the energy store. Such a branching point can additionally or alternatively also be implemented outside the cooling device of the energy store. Additionally or alternatively, the overall circuit can also have a merging point at which the coolant from different coolant lines or from different coolant paths is combined into a common continuous path.The above-described parallel flow also allows a higher cooling capacity and / or an identical cooling capacity to be implemented in a more energy-efficient manner. One part of the coolant is correspondingly cooled by the first heat exchanger and the other part of the coolant is cooled by the second heat exchanger. In this case, therefore, for example, a respective heat exchanger does not have to cool the entire coolant, but only a part thereof, which allows more efficient heat dissipation via the respective heat exchangers. The cooling agents can then in turn be combined or mixed with one another in order to provide a homogeneous cooling temperature of the cooling agent.The above-described design possibilities of the overall circuit can be implemented here in each case for the variant of the coolant paths coupled within the cooling device and for the variant of the coolant paths fluidically separated from one another within the cooling device.In a further very advantageous embodiment of the invention, the first cooling circuit has a first cooling circuit part and a second cooling circuit part, wherein the first cooling circuit part comprises the first coolant inlet and the first coolant outlet, wherein the first cooling circuit part can be fluidically separated from the second cooling circuit part by means of the valve arrangement, so that in the separated state no coolant can be circulated any longer in the first cooling circuit and no coolant located in the first circuit part can be conveyed in the second circuit part. This has the great advantage that, for example, in the event of a leak in the second circuit part of the first cooling circuit, this second circuit part can be decoupled by means of the valve arrangement. The accessibility of the second circuit part can consequently be blocked by the valve arrangement. The coolant can therefore no longer pass from the remaining overall circuit arrangement or from the second cooling circuit into the second circuit part of the first cooling circuit. Nevertheless, the coolant can be circulated in the remaining, intact circuit part of the overall circuit. In other words, cooling can be provided even if there is a leak in the second circuit part of the first cooling circuit.In order to configure the decoupling as efficiently as possible in such a leakage case and in the process to cover as many different leakage cases as possible, it is very advantageous if the valve arrangement for this purpose comprises valves which are located at the interface between the first and second circuit parts of the first cooling circuit and in the process are arranged, for example, as close as possible, that is to say, in terms of flow close to the cooling device of the energy store. For example, a first such valve may be arranged at or in the immediate vicinity of the first coolant inlet and a second such valve may be arranged at or in the immediate vicinity of the first coolant outlet. As a result, the decoupled second circuit part represents almost the entire first cooling circuit. Regardless of where such a leak is thus produced in the first cooling circuit, this always allows a very efficient decoupling of the circuit part with the leak.In principle, it is also conceivable to implement this embodiment analogously for the second cooling circuit. This too can be separable into two separate circuit parts, for example, by the valve arrangement.The valve arrangement for separating the first and second circuit parts can be implemented with at least one passively controlling valve, which can be designed, for example, as a nonreturn valve. This prevents the coolant return flow against the flow direction automatically and without active activation. For example, the coolant can then pass only from the second circuit part into the first circuit part, but no longer return in the opposite flow direction. As a result, the return flow can be automatically blocked in the event of a leak. In order to prevent a flow from the first circuit part into the second circuit part in the flow direction, an actuatable valve is preferred. In principle, the first valve can also be designed as an actuatable valve. If a leak is detected, the control device can correspondingly control the valve device in order to disconnect the second circuit part of the first cooling circuit. Such a decoupling measure can be initiated by the control device in particular, regardless of whether a detected leakage can also be localized or not.As a result, a loss of coolant in the event of a leak can be prevented efficiently and the further operation of cooling the energy store can be ensured. According to a further advantageous embodiment of the invention, the cooling device has a control device for controlling at least a part of the valve arrangement. In particular, the control device can be configured as already described above. In addition, the control device can also be designed to control the first and / or second pump. In addition, the control device can be configured such that it activates the second cooling circuit by actuating the at least one part of the valve arrangement and / or the second pump if a fault event relating to the energy store and / or the first cooling circuit is detected, in particular a thermal runaway of an energy store unit of the energy store and / or a leak in the first cooling circuit and / or a functional failure of the first pump and / or a functional failure of the cooling circuit. Additionally or alternatively, the control device can also be designed to provide the second cooling circuit with a supporting function for energy saving and / or a boost function for providing a maximum possible cooling capacity by actuating the at least one part of the valve device and / or the second pump.Thus, the second cooling circuit can be used not only efficiently in cases of emergency, but also in conventional, normal operating situations. As a result, for example, a more rapid charging for electrically recharging the energy store can be made possible, that is to say higher charging powers are provided, or else a higher cooling power for acceleration processes, that is to say generally in the case of power demand for very high powers from the energy store.Furthermore, the invention also relates to a motor vehicle having a cooling arrangement according to the invention or one of its configurations. The advantages mentioned for the cooling arrangement according to the invention or its embodiments apply in the same way to the motor vehicle according to the invention.Furthermore, the invention also relates to a method for cooling an energy store, wherein the energy store is cooled by means of a first cooling circuit, by means of which a first coolant is conveyed by means of a first pump. In addition, the energy store is cooled by means of a second cooling circuit, by means of which a second coolant is conveyed by means of a second pump when the first cooling circuit is at least partially in an inactive and / or defective state.The advantages mentioned for the cooling arrangement according to the invention and its embodiments also apply here in the same way to the method according to the invention.The invention also includes the control device for the cooling arrangement, in particular for controlling the valve arrangement. The control device can have a data processing apparatus or a processor device which is configured to carry out an embodiment of the method according to the invention. For this purpose, the processor device can have at least one microprocessor and / or at least one microcontroller and / or at least one FPGA (field programmable gate array) and / or at least one DSP (digital signal processor). In particular, a CPU (central processing unit), a GPU (graphic processing unit) or an NPU (neural processing unit) can be used as the microprocessor in each case. Furthermore, the processor device can have program code which is configured to carry out the embodiment of the method according to the invention when executed by the processor device. The program code can be stored in a data memory of the processor device. The processor device can be based on at least one circuit board and / or on at least one SoC (system on chip), for example.The invention also includes developments of the method according to the invention, which have features as have already been described in connection with the developments of the cooling arrangement according to the invention. For this reason, the corresponding developments of the method according to the invention are not described again here.The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car or truck, or as a passenger bus or motorcycle.The invention also includes the combinations of the features of the described embodiments. The invention therefore also comprises implementations which each have a combination of the features of a plurality of the described embodiments, provided that the embodiments have not been described as mutually exclusive.Exemplary embodiments of the invention are described below. The following shows: FIG. 1 shows a schematic illustration of a cooling arrangement according to a first exemplary embodiment of the invention; FIG. 2 shows a schematic illustration of a cooling arrangement according to a second exemplary embodiment of the invention; FIG. 3 is a schematic illustration of a cooling arrangement according to a third exemplary embodiment of the invention; FIG. 4 shows a schematic illustration of a cooling arrangement according to a fourth exemplary embodiment of the invention; FIG. 5 is a schematic illustration of a cooling arrangement according to a fifth exemplary embodiment of the invention; FIG. 6 is a schematic illustration of a cooling arrangement according to a sixth exemplary embodiment of the invention; and FIG. 7 shows a schematic illustration of the second cooling circuit for a cooling arrangement according to an exemplary embodiment of the invention.The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual features of the invention that are to be considered independently of one another and that also develop the invention independently of one another. Therefore, the disclosure is intended to include combinations of the features of the embodiments other than those illustrated. Furthermore, the described embodiments can also be supplemented by further features of the invention that have already been described.In the figures, identical reference numerals designate functionally identical elements.FIG. 1 shows a schematic illustration of a cooling arrangement 10 according to a first exemplary embodiment of the invention. The cooling arrangement 10 comprises a cooling device 12 for an energy store 14. In addition, the energy store 14 can optionally likewise be part of the cooling arrangement 10. Furthermore, the cooling arrangement 10 comprises a first cooling circuit 16 for cooling the energy store 14, and a second cooling circuit 18 for cooling the energy store 14. The cooling device 12 comprises components which are part of the first cooling circuit 16 and components which are part of the second cooling circuit 18. The cooling device 12 comprises a first coolant inlet E 1 and a second coolant inlet E 2. Furthermore, the cooling device 12 comprises a first coolant outlet A 1 and a second coolant outlet A 2. Coolant can be supplied to the cooling device 12 via the inlets E 1, E 2 and the coolant can be discharged again via the outlets A 1, A 2. The cooling device 12 is designed such that the first inlet E 1 is fluidically connected to the first outlet A 1 via an internal flow path. In addition, the cooling device 12 is designed such that the second inlet E 2 is fluidically connected to the outlet A 2 via a corresponding internal flow path. In this example, the cooling device 12 is also designed such that these two flow paths are fluidically separated within the cooling device 12 and cannot be coupled to one another. The first flow path including the first inlet E 1 and the first outlet A 1 is to be regarded as part of the first cooling circuit 16 and correspondingly the second inlet E 2, the second flow path and the second outlet A 2 are to be regarded as part of the second cooling circuit 18. This first cooling structure 20 is also referred to below as primary cooling 20. The first cooling structure 20 can have, for example, a first heat exchanger 22, via which the first cooling circuit 16 is thermally coupled or couplable to a cooling circuit of a motor vehicle in which the cooling arrangement 10 can be used. The cooling of the first cooling circuit 16 can thus take place via an AC (Air Conditioning) system. In order to circulate the coolant in the first cooling circuit 16, a first coolant pump can be provided as part of the first cooling circuit 16, which can be provided in principle at any point of the first cooling circuit 16, but is not illustrated here for reasons of clarity.The second cooling circuit 18 comprises a second cooling structure 24, which is also referred to below as emergency cooling 24. The term emergency cooling does not necessarily imply that the emergency cooling 24 is used only in emergency cases. In embodiments, the emergency cooling 24 can also be used to assist in regular cooling operation. The emergency cooling 24 can likewise comprise a heat exchanger 26. This can be designed, for example, as an ambient heat exchanger. Alternatively, this heat exchanger 26 could also be coupled to an AC system, for example an additional AC system. This coupling can be configured exclusively as a thermal coupling, without a fluidic coupling or alternatively as a fluidic coupling. The coupling can thus be carried out directly or indirectly. In the present example, it is preferred that only an indirect, i.e. exclusively thermal, coupling to a heat sink such as, for example, an environment 28 is provided by the heat exchanger 26 in order to cool the coolant circulating in the second cooling circuit 18. The coolant circulating in the first and second cooling circuits 16, 18 can be, in particular, the same coolant. This allows simple mixing of the cooling media in the case of fluidic coupling of the two cooling circuits 16, 18, as described in more detail below.In order to now couple these cooling circuits 16, 18 to one another or to decouple them from one another as required, a valve device 30 can be provided. In the present case, this comprises a plurality of valves V 1, V 2, V 3. In addition, the cooling arrangement 10 comprises a first auxiliary line 32 and a second auxiliary line 34. Both auxiliary lines 32, 34 enable a fluidic connection between the two cooling circuits 16, 18. The cooling arrangement 10 comprises in this example four coupling points, namely a first coupling point P 1, which also simultaneously represents a branching point 36, a second coupling point P 2, a third coupling point P 3 and a fourth coupling point P 4, which simultaneously represents a merging point 38. The first additional line 32 leads from the first coupling point P 1 to the second coupling point P 2 and the second additional line 34 leads from the third coupling point P 3 to the fourth coupling point P 4. The first coupling point P 1 is arranged in the flow direction, which is illustrated by the arrows shown, in the first cooling circuit 16 upstream of the cooling device 12, the second coupling point P 2 is arranged in the second cooling circuit 18 upstream of the cooling device 12, the third coupling point P 3 is arranged in the flow direction between the emergency cooling device 24 and the second coupling point P 2 and the fourth coupling point P 4 is arranged downstream of the cooling device 12 and upstream of the primary cooling device 20 in the first cooling circuit 16 in the flow direction.If the valves V 1, V 3 are closed and the second valve V 2 is open, the cooling circuits 16, 18 are completely decoupled from one another. As a result, for example, a coolant can be circulated in the second circuit part 18 independently of the operation of the first circuit part 16. It is likewise possible to operate the first cooling circuit 16 at the valve position mentioned independently of the operation of the second cooling circuit 18. In a normal operating situation, for example, the energy store 14 can be cooled only via the first cooling circuit 16. The emergency cooling system 24 can be additionally connected to support the first circuit 16. The energy store 14 can therefore also be cooled simultaneously by both cooling circuits 16, 18. If a failure of the first cooling circuit 16 or any other malfunction occurs which no longer allows cooling via the first cooling circuit 16, the energy store 14 can also be operated only by the operation of the second cooling circuit 18. The above-described valve position of the valve device 30 can define a first operating state. Such an operating state is also referred to below in part as an operating mode.In the description of the flow paths, in particular with reference to FIGS. 1 to 6, the primary cooling 20 is selected partially as a starting point by way of example. In principle, any other desired starting point can also be selected. The coolant circulates in a closed circuit and accordingly passes through the described devices repeatedly and cyclically. The sequence of the pass is maintained per flow path.In addition, the arrows shown in FIGS. 1 to 7, except for the arrows denoted by Vx in FIG. 7, not only illustrate the flow directions, but also symbolise fluid lines, e.g. pipes and / or hoses.According to a second operating state according to the example shown in FIG. 1, the valves V 1 and V 3 are open and the second valve V 2 is closed. As a result, the two circuits 16, 18 are fluidically coupled to form an overall circuit 39. The coolant then flows, for example starting from the primary cooling 20 in the direction of the cooling device 12 and is divided at the first point P 1 into a first branch which leads to the first inlet E 1 of the cooling device 12 and a second branch which leads to the second point P 2. A portion of the coolant flows through the first flow path in the cooling device 12 and exits from the first outlet A 1 again and is fed back to the primary cooling 20. The second coolant part reaches the cooling device 12 via the second point P 2 and via the second inlet E 2 and exits from the latter from the second outlet A 2, is then fed to the emergency cooling device 24, is then fed to the primary cooling device via the third point P 3 and the fourth point P 4. In this second operating state, the coolant cooled by the primary cooling 20 can be supplied directly, i.e. without the intermediate connection of the emergency cooling 24, via the two inputs E 1, E 2 to the cooling device 12. The coolant emerging at the outlets A 1, A 2 is, on the one hand, in turn fed directly to the primary cooling system 20 and, on the other hand, passes through the emergency cooling system 24 again before it is fed back to the primary cooling system 20. This provides two flow paths which are passed through in particular in parallel. One part of the coolant is cooled per pass only by the primary cooling 20 and another part of the coolant is cooled per pass by both cooling means, i.e. the primary cooling 20 and the emergency cooling 24. In this case, the emergency cooling 24 is arranged upstream of the primary cooling 20 according to the second flow path. This means that the coolant first passes through the emergency cooling system 24 and then through the primary cooling system 20 before it is fed again to the cooling system 12. As a result, higher cooling capacities can be provided overall. The primary cooling 20 can also be supported during its operation by the emergency cooling 24.FIG. 2 shows a schematic illustration of a cooling arrangement 10 according to a second exemplary embodiment of the invention. This can have in particular the same components or be embodied in the same way as the cooling arrangement 10 from FIG. 1, except for the differences described below, which relate substantially only to the additional lines, the coupling points and the valve arrangement 30. The valve arrangement 30 comprises four valves V 4, V 5, V 6, V 7 in this example. In addition, the cooling arrangement 10 in turn comprises two additional lines 40, 42 which fluidically couple the first cooling circuit 16 and the second cooling circuit 18 to one another in each case. In addition, the cooling arrangement 10 again comprises four coupling points P 5, P 6, P 7, P 8. The first auxiliary line 40 connects the coupling points P 5 and P 6, and the second auxiliary line 42 connects the coupling points P 7 and P 8. The first coupling point P 5 is arranged between the first outlet A 1 and the primary cooling 20 in the flow direction. The second coupling point P 6 is arranged between the second outlet A 2 and the emergency cooling 24. The third coupling point P 7 is arranged between the second output A 2 and the second coupling point P 6, and the fourth coupling point P 8 is arranged between the first coupling point P 5 and the primary cooling 20. In this way, too, different operating states can be realized in turn.In a first operating state, the valves V 4, V 7 are opened and the valves V 6, V 5 are closed. The additional lines 40, 42 are thereby blocked. The two cooling circuits 16, 18 are thereby completely fluidically decoupled and can be operated independently of one another. This corresponds to the first operating state, as was described with reference to FIG. 1.In the second operating state, the valves V 5, V 6 are open and the valves V 4, V 7 are closed. This results in the following flow path: the coolant flows starting from the primary cooling 20 via the first inlet E 1 into the cooling device 12, exits from the first outlet A 1, is supplied via the coupling point P 5 and the coupling point P 6 to the emergency cooling device 24, and from there via the second inlet E 2 of the cooling device 12, exits from the second outlet A 2 from the cooling device 12 and is subsequently supplied via the coupling points P 2 and P 8, that is to say via the second additional line 42, again to the primary cooling device 20. Viewed in the direction of flow, the coolant accordingly flows through the primary cooling 20, then into the cooling device 12, then the emergency cooling 24, then again the cooling device 12, then again the primary cooling 20, and so on. In this case, primary and secondary cooling 20, 24 are connected in series, i.e. connected in series. As a result, the primary cooling 20 can in turn be supported by the additional operation of the emergency cooling 24, in particular in regular operating situations.In the event of a leak in the first cooling circuit 16, the cooling arrangement 10 is preferably operated in the first operating mode. In this operating mode, the first and the second cooling circuit 16, 18 are completely fluidically decoupled from one another. Accordingly, the coolant circulated in the second cooling circuit 17 cannot leak out through the leak located in the first cooling circuit 16. In addition, the operation of the first cooling circuit 16 can be adjusted in the event of such a leakage. This also applies to the cooling arrangement described with reference to FIG. 1.For controlling and changing these operating modes and in particular for controlling the valve arrangement 30 and in particular the mentioned pumps assigned to the respective cooling circuits 16, 18, a control device likewise not shown here can additionally be provided. This can carry out the control depending on a situation parameter. This situation parameter can relate, for example, to an ambient temperature of the environment 28, other temperatures, for example the temperature of the energy store 14, of the coolant in the corresponding cooling circuits 16, 18 or such a situation parameter can also specify many states, in particular fault states detected by a detection device, such as, for example, the aforementioned leakage, a thermal runaway of at least one cell of the energy store 14, another fault relating to the first cooling circuit 16 or a cooling circuit or the like. This also applies to the cooling arrangement 10 described with reference to FIG. 1 and to the examples explained with reference to FIGS. 3 to 7.By means of the cooling arrangement 10 illustrated in FIG. 2, a series connection of primary cooling 20 and emergency cooling 24 can be provided. In the first operating mode, a complete separation of both circuits 16, 18 can be realized by the separate circuits inside the battery and, as a result, a fluid loss in the second circuit 18 in the event of a leak in the first circuit 16, namely by the described valves V 4, V 5, V 6, V 7, can be avoided under certain circumstances, for example in the event of a leak. The coupling of the two battery circuit systems, i.e. of the two cooling circuits 16, 18, can be realized in the examples illustrated in FIGS. 1 and 2 via an interconnection of the outer circuits 16, 18, that is to say by an interconnection of these circuits 16, 18 externally of the cooling device 12.FIG. 3 shows a schematic illustration of a cooling arrangement 10 according to a third exemplary embodiment of the invention. This can be configured as before, except for the differences described below. In this example, the two flow paths are fluidically coupled to one another within the cooling device 12. The cooling device 12 can therefore itself represent a branching point 36' and / or a merging point 38'. Such a branching point 36' and a combining point 38' can be realized at the same or different points within the cooling device 12. A coolant supplied via the first inlet E 1 to the cooling device 12 can therefore emerge both via the first outlet A 1 and via the second outlet A 2 or emerge proportionally both via the first and the second outlet A 1, A 2. The outlet via the first outlet A 1 can also be blocked via the valve device 30, which is explained in more detail later. In this example, no additional lines are now provided. The valve device 30 comprises two valves V 9, V 10. These are both arranged in the first cooling circuit 16. The first valve V 9 is located between the primary cooling 20 and the first inlet E 1 of the cooling device 12, again viewed in the flow direction. The second valve V 10 is located between the first outlet A 1 and the primary cooling 20, and in a first operating state, the two valves V 9, V 10 are both open. In this first operating state, the two circuits 16, 18 can both contribute to cooling the energy store 14. The coolant can circulate both in the first cooling circuit 16 and in the second cooling circuit 18, wherein the coolant is mixed within the cooling device 12. The coolant which is supplied via the first inlet E 1 and the coolant which is supplied via the second inlet E 2 can mix as cooling-direction sintering 12. A part of the coolant supplied via the first inlet E 1 can thus emerge via the first outlet A 1 and the other part can emerge via the second outlet A 2. The same applies to the coolant supplied via the second inlet E 2. The two circuits 16, 18 are thus fluidically coupled to one another within the cooling device. In this respect, the first operating state in the present case differs from the first operating states described with reference to FIGS. 1 and 2 in that the two circuits 16, 18 are not operated independently of one another and in that a coolant exchange between the two circuits 16, 18 can take place in the first operating state according to the example from FIG. 3. If a defect occurs, for example of the energy store or of the first cooling circuit 16, for example a leak within the first cooling circuit 16, then a second operating state can be entered, according to which the two valves V 9, V 10 are closed. In this case, a part of the first cooling circuit 16 is decoupled. The first cooling circuit 16 can thus be divided into a first circuit part 16 aand a second circuit part 16 b. The two circuit parts 16 a, 16 bcan be fluidically separated from one another by closing the two valves V 9, V 10. If the two valves V 9, V 10 are closed, the coolant can no longer circulate in the first cooling circuit 16. However, the coolant in the second cooling circuit 18 can continue to be circulated. As a result, the emergency cooling 24 can also continue to provide cooling of the energy store 14. In this situation, an escape of coolant from the first cooling circuit 18 as a result of a leak in the second circuit part 16 bof the first cooling circuit 16 is also avoided or prevented. Accordingly, it is advantageous if the valves V 9, V 10 are arranged as close as possible to the cooling device 12, so that the first circuit part 16 ais significantly smaller than the second circuit part 16 b. The size can be dimensioned on the basis of the distance to be covered by the coolant when flowing through the respective circuit parts 16 a, 16 b. The first valve V 9 is therefore preferably positioned in the region of the first inlet E 1, for example in the immediate vicinity of this inlet E 1, and the second valve V 10 is positioned as close as possible to the first outlet A 1, for example in the immediate vicinity thereof.This example of the cooling arrangement 10 therefore comprises circuits coupled internally to the battery for providing a parallel flow, in particular according to the first operating mode described above, having two valves, wherein one, namely the first valve V 9, can also be a passive valve, that is to say a passive-switching valve, for example a nonreturn valve, in order to prevent a fluid loss in the first cooling circuit 18 in the event of damage or leakage in the first cooling circuit 16. Such a leak may occur, for example, as a result of a crash of the motor vehicle. This is realized by the above-described second operating state.FIG. 4 shows a schematic illustration of a cooling arrangement 10 according to a fourth exemplary embodiment of the invention. This can be designed in particular as described with reference to FIG. 3, except for the differences described below. In the present example, an additional additional line 44 is now provided, which fluidically connects the two coupling points P 9, P 10 to one another. Via this additional line 44, an additional fluidic coupling possibility is provided between the two circuits 18, 16, that is to say in addition to the fluidic coupling which is realized within the cooling device 12 by the coupled two flow paths through the cooling device 12.One of these coupling points P 10 is located in the first cooling circuit 16 and, as viewed in the flow direction, between the cooling device 12, in particular the first outlet A 1 of the cooling device 12, and the primary cooling 20, and the second coupling point P 9 is located in the second cooling circuit 18 between the emergency cooling 24 and the second inlet E 2 of the cooling device 12, as viewed in the flow direction.In this case, the valve arrangement 30 comprises four valves V 9, V 10, V 11, V 12, wherein the position of the two valves V 9, V 10 corresponds to the position of the two valves V 9, V 10 from FIG. 3 or can be identical thereto. The third valve V 11 is arranged between the emergency cooling system 24 and the second inlet E 2 of the cooling system 12 as viewed in the flow direction, and the fourth valve V 12 is arranged in the auxiliary line 44. The fourth valve V 12 is located between the coupling points P 9 and P 10 as viewed in the flow direction.In a first operating mode or first operating state, the valves V 9, V 10, V 11 can be opened and the fourth valve V 12 can be closed. This first operating state then corresponds to the first operating state described with reference to FIG. 3.In a second operating state, the valves V 9, V 10, V 12 are closed and the third valve V 11 is open. As a result, the second circuit part 16 bof the first cooling circuit 16 is in turn decoupled from the first circuit part 16 a. This operating state corresponds to the second operating state described with reference to FIG. 3 and can be assumed, for example, in the event of a fault, for example, in the event of a leak in the first cooling circuit 16.The cooling arrangement 10 illustrated in FIG. 4 additionally enables a third operating state, according to which the valves V 10, V 11 are closed and the valves V 9, V 12 are open. This results in the following flow path: the coolant initially passes through the cooling device 12 beginning at the primary cooling 20, exits through the second outlet A 2, passes through the emergency cooling 24 and is subsequently fed back to the primary cooling 20 via the additional line 44, and so on.According to this third operating state, the two cooling devices 20, 24 are again connected in series with the cooling device 12. In particular, the primary cooling 20 is located between the emergency cooling 24 and the cooling device 12 as viewed in the flow direction. The emergency cooling 24 can precool the coolant exiting from the cooling device 12 and this can be cooled down even more strongly by the primary cooling 20 before it is fed back to the cooling device 12. As a result, the primary cooling 20 can also be supported by the emergency cooling 24 in regular operation or a boost function can also be provided in order to achieve even higher cooling capacities than would be possible by the primary cooling 20 alone.Based on this third operating state, further modifications are possible as further operating states. For example, starting from the described third operating state, the valve V 10 can be open instead of closed. In this case, the coolant supplied via the first inlet E 1 can emerge from both outlets A 1, A 2. A portion of the emerging coolant is thus in turn fed directly to the primary cooling 20, namely the coolant emerging from the first outlet A 1, while the coolant portion emerging via the second outlet A 2 initially passes through the emergency cooling 24 and is then fed to the primary cooling 20. In this case, therefore, only a portion of the coolant exiting from the cooling device 12 is additionally cooled once again by the emergency cooling 24. These two flow paths are joined together again via the coupling point P 10.It would also be conceivable to provide a further operating state based on the described third operating state, wherein now the valve V 11 can be opened instead of closed. In this case, only a portion of the coolant which has passed through the emergency cooling system 24 would be fed directly again to the primary cooling system 20, while another portion is fed again to the cooling system 12 via the second inlet E 2.The two latter operating states, namely the fourth and fifth operating states, can also be combined by both valves V 10, V 11 being open, that is to say in addition to the valves V 9, V 12 which are open anyway according to this further operating state.In this way, a plurality of flow paths can be realized, some of which provide a serial flow through the two cooling systems 20, 24 and some of which provide a parallel flow through them.FIG. 5 shows a schematic illustration of a cooling arrangement 10 according to a fifth exemplary embodiment of the invention. The cooling arrangement 10 can in particular again be configured as described with respect to FIG. 3 except for the differences described below: the cooling arrangement 10 in turn comprises an additional line 46 and the valve arrangement 30, which in the present case comprises five valves V 9, V 10, V 11, V 13, V 14. The valves V 9 and V 10 can be configured with regard to their positioning as described with reference to FIG. 3 and the valve V 11 as described with reference to FIG. 4. The additional line 46 connects the two circuits 16, 18 fluidically to one another, in particular in addition to the fluidic coupling inside the cooling device, and provided the valve V 13 is open. The auxiliary line 46 connects the second coupling points P 11 and P 12 to each other. The coupling point P 11 is arranged in the first cooling circuit 16 and the second coupling point P 12 in the second cooling circuit 18. the first coupling point P 11 is located between the primary cooling 20 and the first inlet E 1 of the cooling device 12 as viewed in the flow direction. the second coupling point P 12 is located between the second outlet A 2 of the cooling device 12 and the emergency cooling device 24. the valve V 14 is located between the second outlet A 2 and the coupling point P 12. The valve V 13 is located in the auxiliary line 46, in particular at any desired point.According to a first operating state, the valves V 9, V 10, V 11, V 14 are opened and the valve V 13 is closed. This first operating state in turn corresponds to the first operating state, as was described for example with reference to FIGS. 3 and 4. According to a second operating state, the valves V 9, V 10, V 11, V 13 are opened and the valve V 14 is closed. This results in two flow paths: a first flow path, again for example starting from the primary cooling 20, leads from the latter to the first inlet E 1, through the cooling device 12 and via the first outlet A 1 back to the primary cooling 20, a second flow path leads starting from the primary cooling 20 via the additional line 46 to the emergency cooling 24 and then to the second inlet E 2 of the cooling device 12, through the latter and then via the first outlet A 1 back to the primary cooling 20. One part passes through only the primary cooling 20 in relation to one cycle if the other part passes through both the primary cooling and the emergency cooling 24, and in particular first the primary cooling 20 and then the emergency cooling 24, before it is fed to the cooling device 12. A modification of this wide operating state can be provided by the valve V 9 being closed instead of opened according to a further operating state based on this second operating state. As a result, the coolant, starting from the primary cooling 20, initially passes through the emergency cooling 24 before it is fed to the cooling device 12 via the second inlet E 2 and is fed again to the primary cooling 20 via the outlet from the first outlet A 1. This allows a pure serial circuit of primary and secondary cooling 20, 24 to be provided. This can, for example, in turn be used as boost cooling.A further, in particular fourth, operating state can be provided in that, according to this fourth operating state, the valves V 9, V 10, V 13 are closed and the valves V 11, V 14 are open. As a result, the second circuit part 16 bis in turn decoupled from the first circuit part 16 aof the first cooling circuit 16 and the second cooling circuit 18 can be operated independently of the first cooling circuit 16. This operating mode corresponds to the second operating state, as was also described for example in FIG. 3.This mode of operation is again suitable if there is a leak in the first cooling circuit 16, in particular in the second circuit part 16 b.FIG. 6 shows a schematic illustration of a cooling arrangement 10 according to a sixth exemplary embodiment of the invention. The cooling arrangement 10 can be configured as explained with reference to FIG. 5, except for the differences described below. In this case, a further additional line 48 is now provided between the coupling points P 12 and P 13. The cooling arrangement 10 also comprises the additional coupling point P 13 in the second cooling circuit 18. the coupling point P 13 is located between the emergency cooling 24 and the second inlet E 2 of the cooling device 12 in the flow direction. the coupling point P 13 is positioned such that the valve V 11 is located between the emergency cooling 24 and this coupling point P 13, as viewed in the flow direction. The auxiliary line 48 also comprises a further valve V 15. This valve can also be part of the valve arrangement 30. When the valve V15 is closed, the same possible operating states result as those described with reference to FIG. 5. In the following, therefore, only the further possible operating states according to which the valve V 15 is open will be explained. According to a first further operating state, the valves V 13, V 15 are opened and the valves V 11, V 14 are closed and the valve V 10 is opened. As a result, the emergency cooling 24 can be bridged or bypassed. The coolant therefore does not flow through the emergency cooling 24 in this operating state. The coolant can be supplied from the primary cooling 20 via the first additional line 46 and the second additional line 48 via the second inlet E 2 to the cooling device 12 and can emerge again via the first outlet A 1 and be supplied again to the primary cooling 20. If the valve V 9 is closed, this represents the only possible flow path. However, the valve V 9 can also be additionally open. The coolant then divides itself, starting from the primary cooling 20, in the flow direction at the point P 11 into two different paths, namely the already described flow path, and a further flow path which leads starting from the point P 11 via the first inlet E 1 into the cooling device 12. The coolant then exits again at the first outlet A 1 and is fed to the primary cooling 20. In this case, the coolant is likewise cooled exclusively by the primary cooling 20, wherein the coolant can be fed into the cooling device 12 via both inlets E 1, E 2 proceeding from the primary cooling 20.According to a further operating state, the emergency cooling 24 can also contribute additionally. This differs from the last-described operating states in that the valve V 11 is open and is not closed. The coolant then divides from the primary cooling 20 at the point P 12 into a direct path to the cooling device 12 via the point P 13 and the second inlet E 2, and an indirect path via the emergency cooling 24, the point P 13 and the second inlet E 2. A portion of the coolant can therefore also be additionally cooled by the emergency cooling 24.In principle, numerous further design possibilities are also conceivable, in particular further operating states. To name an example, the valve V 14 can also be opened, as a result of which the coolant supplied to the cooling device 12 can emerge via both outputs A 1, A 2 and the coolant emerging via the second output A 2 can be supplied to the emergency cooling device 24, before said emergency cooling device is supplied via the second input E 2 once again to the cooling device 12.As a result of these operating states, it is possible, in particular, depending on the actuation of the valve device 30, to provide boost cooling with optional serial use of primary and secondary cooling 20, 24.FIG. 7 shows a schematic illustration of the second cooling circuit 18 for a cooling arrangement 10 (cf. FIGS. 1 to 6 ) according to an exemplary embodiment of the invention. This second cooling circuit 18 can be configured as described above, wherein in the present case further details of the components of this second cooling circuit 18 are shown. On the one hand, the pump 50 integrated therein is also illustrated as part of the second cooling circuit 18 in order to convey the coolant in the second cooling circuit 18. Also illustrated in more detail is the emergency cooling 24. As already mentioned, this comprises a heat exchanger, which in the present example is designed as an ambient heat exchanger for dissipating heat 52 to the environment 28. In addition, the emergency cooling 24 can also comprise a fan 54 in order to make the heat dissipation even more efficient or effective. Also illustrated in more detail is the second flow path 56 connecting the second inlet E 2 to the second outlet A 2 of the cooling device 12. This flow path 56 can be divided into individual partial flow paths 56 a, which can be realized by individual cooling channels running through the cooling device 12. The arrows labeled Vx may each symbolize a valve.These valves Vx may each have at least one closed state and one open state. In normal operation, that is to say without the presence of a defect or another critical state of the energy store 14, the valves Vx can be in the open state. If, for example, a battery cell of the energy store 14 passes through thermally, it is possible, by actuating and switching the valves Vx, to cool certain regions of the cooling device 12 to an increased extent and others in turn to a lesser extent or not at all. As a result, for example, the critical sector of the energy store 14, which therefore comprises the thermally continuous battery cell, optionally also adjacent cells of this thermally continuous battery cell, and which corresponds to one or more of the individual cooling channels 56 a, can be cooled in a targeted manner. This therefore enables the targeted flooding of the thermally critical sector and, if appropriate, of the adjacent regions, in order in this way to specifically restrict the thermal event. The cooling channels 56 acan also be formed by segments of the receiving space of the energy store 14 themselves which are sealed or sealed from one another and in which the battery cells of the energy store 14 are arranged. As a result, the receiving spaces with the critical cells can be flushed directly with the coolant and a thermal event can be controlled even more efficiently.This configuration of the second cooling circuit 18 can be combined with each of the variants described above according to FIGS. 1 to 6.Moreover, the cooling arrangements 10 illustrated in FIGS. 1 to 7 and in particular the corresponding cooling circuits 16, 18 do not show all components which may be present in such a cooling circuit. In other words, the illustration of the cooling arrangement 10, the cooling circuits 16, 18 and the overall circuit 39 are simplified illustrations for reasons of clarity. In the respective cooling circuits, numerous further components and elements can be present in addition to the pumps. The respective circuits themselves can also be subdivided into further sub-circuits and each have a significantly more complex structure. This applies in particular to the first cooling circuit 16.In principle, the valves, generally the at least one valve of the valve arrangement, can not only have an open and a closed state, but can in each case also in principle be designed such that the flow rate through the relevant valve can be changed and / or controlled in stages or continuously, for example between a fully closed and a fully open state with a maximum flow rate. As a result, the fluid portions of the coolant which are divided between the individual flow paths described can be controlled. It is also possible in this way to create continuous transitions between the individual operating states described, if required.Overall, the examples show how a battery cooling concept can be provided by the invention, in particular a cooling concept for the high-voltage accumulator for restricting and preventing thermal propagation. This makes it easier to restrain thermal runaway of a cell and to restrain progression or transfer to neighboring cells with appropriate fluid cooling. On the one hand, this enables the containment of a thermal event and thus a risk containment, and on the other hand, the proposed cooling concept can also be used for boost cooling and enables rapid charging and acceleration.In addition, further measures can be provided and / or by means of which the cooling arrangement can be provided, such as, for example, the use of non-conductive and flame-retardant fluids as coolant, the ensuring of a permanent cooling fluid flow, even in the event of a defect, which is made possible by the emergency cooling, the ensuring of the cooling and heat emission of the fluid either by an active cooling concept by connection to the AC system or as a passive cooling concept with a pump-heat exchanger combination and the heat emission to an environment, the preferably direct suppression and / or elimination and / or the removal of oxygen from a damaged cell, a direct cooling of individual cells via the large in-vehicle cooling circuit, namely the first cooling circuit, and via the emergency cooling circuit, which is preferably likewise configured in the vehicle and can encapsulate itself from the existing large circuit, In order to form a separate circuit, which can also be implemented as an at least partially external circuit, for example in combination with an additional interface at the quick charging station, the reduction of the fluid flow to the critical section, that is to say a battery section with the damaged cell or thermally continuous cell, for example by segmentation and / or partition walls and optionally the direct environment of this cell. This has advantages above all, for example in vehicle displacements or rapid charging processes.The emergency cooling circuit and / or auxiliary cooling circuit, which is referred to herein as a second cooling circuit, can be operated in parallel operation in addition to the first cooling circuit or in a separate operation. The separate operation of the first cooling circuit, i.e. of the main cooling circuit system, is also conceivable. The coupling and decoupling can be effected via actuators. In addition, the cooling circuits may be implemented with separate cooling systems internal to the battery or fluidically coupled cooling systems internal to the battery.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 10 2020 127 572 A1

[0003] DE 10 20197 809 A1

[0005]

Claims

Cooling arrangement (10) for cooling an energy store (14), - which has a first cooling circuit (16) for cooling the energy store (14), - wherein a coolant can be circulated in the first cooling circuit (16), and - the first cooling circuit (16) comprises at least one first pump, by means of which the coolant can be conveyed through the first cooling circuit (16), characterized in that - the cooling arrangement (10) comprises a second cooling circuit (18) for cooling the energy store (14), - wherein a coolant can be circulated in the second cooling circuit (18), and - wherein the second cooling circuit (18) has a second pump (50), by means of which the coolant can be conveyed through the second cooling circuit (18) when the first cooling circuit (16) is at least partially in an inactive and / or defective state.Cooling arrangement (10) according to Claim 1, characterized in that the first cooling circuit (16) is in the inactive and / or defective state if - a cooling circuit, to which the first cooling circuit (16) is thermally coupled or couplable, is inactive and / or no heat can be transferred from the first cooling circuit (16) to the cooling circuit, and / or - the first pump is inactive, and / or - the first cooling circuit (16) has a leak.Cooling arrangement (10) according to one of the preceding claims, characterized in that - the first cooling circuit (16) comprises a first heat exchanger (22) for transferring heat from the first cooling circuit (16) to a first heat sink, in particular wherein the first cooling circuit (16) is thermally coupled or couplable to a cooling circuit via the first heat exchanger (22), and / or - the second cooling circuit (18) comprises a second heat exchanger (26) for transferring heat from the second cooling circuit (18) to a second heat sink, in particular wherein the second cooling circuit (18) is coupled or couplable to an environment (28) via the second heat exchanger (26).Cooling arrangement (10) according to one of the preceding claims, characterized in that the cooling arrangement (10) comprises a valve arrangement (30) comprising at least one valve (V1 - V15), by means of which the first and the second cooling circuit (18) can be fluidically coupled at at least one point and can be fluidically separated, and by coupling the first and the second cooling circuit (18) from at least part of the first cooling circuit (16) and at least part of the second cooling circuit (18) an overall circuit (39) can be formed, in which a coolant can be circulated.Cooling arrangement (10) according to one of the preceding claims, characterized in that the energy store (14) is assigned a cooling device (12), - which has a first coolant inlet (E1) and a second coolant inlet (E2), - which has a first coolant outlet (A1) and a second coolant outlet (A2), - which provides a first coolant path as part of the first cooling circuit (16), wherein the first coolant path fluidically connects the first coolant inlet (E1) and the first coolant outlet (A1) to one another, - which provides a second coolant path (56a) as part of the second cooling circuit (18), wherein the second coolant path (56a) fluidically connects the second coolant inlet (E2) and the second coolant outlet (A2) to one another, and - the first coolant path and the second coolant path (56a) are or can be fluidically coupled.Cooling arrangement (10) according to one of the preceding claims, characterized in that the energy store (14) is assigned a cooling device (12), - which has a first coolant inlet (E1) and a second coolant inlet (E2), - which has a first coolant outlet (A1) and a second coolant outlet (A2), - which provides a first coolant path as part of the first cooling circuit (16), wherein the first coolant path fluidically connects the first coolant inlet (E1) and the first coolant outlet (A1) to one another, - which provides a second coolant path (56a) as part of the second cooling circuit (18), wherein the second coolant path (56a) fluidically connects the second coolant inlet (E2) and the second coolant outlet (A2) to one another, and - the first coolant path and the second coolant path (56a) are separated from one another in fluidic fashion.Cooling arrangement (10) according to one of the preceding claims, characterized in that the overall circuit (39) which can be formed by means of the valve arrangement (30) is designed in such a way that - the coolant can flow through the first heat exchanger (22) and the second heat exchanger (26) in series when the coolant circulates in the overall circuit (39), in particular • wherein a first flow path is provided by the overall circuit (39), according to which flow path the first heat exchanger (22) is arranged between the cooling device (12) and the second heat exchanger (26) in the flow direction, and / or • wherein a second flow path is provided by the overall circuit (39), according to which flow path the second heat exchanger (26) is arranged between the cooling device (12) and the first heat exchanger (22) in the flow direction, and / or • wherein a third flow path is provided by the overall circuit (39), according to which flow path the coolant is cooled, which has passed through the first heat exchanger (22), first flows through the cooling device (12), then through the second heat exchanger (26), and then again through the cooling device (12) before it is fed back to the first heat exchanger (22); and / or - that the overall circuit (39) has at least one branching point (12, 36'), at which, when the coolant circulates in the overall circuit (39), a first part of the coolant can be fed to the first heat exchanger (22) and a second part of the coolant can be fed to the second heat exchanger (26), in particular during or after passing through the cooling device (12).Cooling arrangement (10) according to one of the preceding claims, characterized in that the first cooling circuit (16) has a first circuit part (16a) and a second circuit part (16b), wherein the first circuit part (16a) comprises the first coolant inlet (E1) and the first coolant outlet (A2), wherein the first circuit part (16a) can be fluidically separated from the second circuit part (16b) by means of the valve arrangement (30), such that in the separated state coolant can no longer be circulated in the first cooling circuit (16) and no coolant located in the first circuit part (16a) can be conveyed into the second circuit part (16b).Cooling arrangement (10) according to one of the preceding claims, characterized in that the cooling arrangement (10) has a control device for controlling at least a part of the valve arrangement (30) and the first and / or second pump (50), wherein the control device is configured in such a way that it activates the second cooling circuit (18) by actuating the at least a part of the valve arrangement (30) and / or the second pump (50), - if a fault event relating to the energy store (14) and / or the first cooling circuit (16) is detected, in particular a thermal runaway of an energy storage unit of the energy store (14) and / or a leak in the first cooling circuit (16) and / or a functional failure of the first pump and / or a functional failure of the cooling circuit; and / or - in a specific first operating situation, for supporting the cooling function of the first cooling circuit (16) and for saving energy; in a certain second operating situation for providing a boost function for providing a total cooling power for cooling the energy store (14), which is increased compared to the maximum cooling power that can be provided by the first cooling circuit (16) in the inactive state of the second cooling circuit (18).Method for cooling an energy store (14), - wherein the energy store (14) is cooled by means of a first cooling circuit (16), by means of which a first coolant is conveyed by means of a first pump, characterized in that - the energy store (14) is cooled by means of a second cooling circuit (18), by means of which a second coolant is conveyed by means of a second pump, when the first cooling circuit (16) is at least partially in an inactive and / or defective state.

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