Motor vehicle with coolant circuit and, if required, usable flooding areas through which coolant can flow in a battery storage unit

Abstract

A motor vehicle (10) is described, comprising at least a partially electric drive; a battery storage unit (12) containing several battery cell modules (12m); and a coolant circuit (14) thermally connected to the battery storage unit (12) to condition, in particular cool, the battery storage unit (12) during operation of the motor vehicle (10). The battery storage unit (12) is provided to have at least one flooding area (26) configured to be flooded with coolant from the coolant circuit (14), wherein the flooding area (26) is free of coolant during normal operation of the battery storage unit (12), and that the flooding area (26) is associated with at least one switchable connecting element (28) which is closed during normal operation. wherein the switchable connecting element (28) is connected to the coolant circuit (14) and is designed to be opened as required, such that the flooding area (26) is filled with coolant, is fluidically integrated into that of the coolant circuit (14) and is permeated by coolant.

Description

[0001] The invention relates to a motor vehicle having an at least partially electric drive; a battery storage unit containing a plurality of battery cell modules; and a coolant circuit that is in thermal operative connection with the battery storage unit in order to condition, in particular to cool, the battery storage unit during operation of the motor vehicle.

[0002] In motor vehicles with a battery storage unit, in particular a high-voltage battery storage unit, there is a need to enable safe handling of so-called thermal events, for example degassing of a battery cell or the like.

[0003] For example, DE 10 206 219 284 A1 discloses introducing coolant between adjacent energy storage cells if a threshold temperature is exceeded in one energy storage cell. The introduction occurs once from a pressure vessel in which the coolant is stored under pressure and carried in the vehicle.

[0004] Furthermore, reference is also made to DE 10 2012 215 736 A1, DE 44 458 20 A1 and EP 1 693 632 A2 regarding the state of the art.

[0005] The object underlying the invention is to provide a motor vehicle with a battery storage device in which improved cooling is possible in the event of a thermal event.

[0006] This problem is solved by a motor vehicle having the features of the independent patent claim. Advantageous embodiments with useful further developments are specified in the dependent patent claims.

[0007] What is proposed is a motor vehicle with an at least partially electric drive; a battery storage unit containing a plurality of battery cell modules; a coolant circuit that is in thermal operative connection with the battery storage unit in order to condition, in particular to cool, the battery storage unit when required during operation of the motor vehicle.It is provided that the battery storage unit has at least one flooding area which is designed to be flooded with coolant from the coolant circuit, wherein the flooding area is free of coolant during normal operation of the battery storage unit, and that at least one switchable connecting means is assigned to the flooding area, which is closed during normal operation, wherein the switchable connecting means is connected to the coolant circuit and is designed to be opened as required, such that the flooding area is filled with coolant, is fluidically incorporated into the coolant circuit and has coolant flowing through it.

[0008] This makes it possible to additionally cool the battery storage unit, at least partially, for example, in the area of ​​a specific battery cell module. The flooding area is actively integrated into the coolant circuit and coolant flows through it, allowing heat to be dissipated efficiently and over a longer period of time by means of the coolant in the flooding area. Furthermore, this type of cooling can be implemented using a coolant circuit already present in a motor vehicle.

[0009] The term "operation of the motor vehicle" used here can also be understood as a type of normal operation, i.e., in particular, operation in which no irregularities or malfunctions occur in the motor vehicle or the battery storage unit. Furthermore, it should be noted that cooling for the battery storage unit can be requested both while driving and during the charging process, i.e., when the motor vehicle is stationary. Thus, the term "operation" or "normal operation" in this regard also includes a stationary motor vehicle during the charging process.

[0010] In the motor vehicle, the coolant circuit can have an expansion tank for coolant, wherein the volume of the expansion tank is oversized by at least one filling volume of the flooding area. This ensures that a sufficient quantity or volume of coolant is kept in the expansion tank at all times to guarantee the operation of the coolant circuit and to ensure that at least one flooding area is flooded with coolant. A multiple of the filling volume of a flooding area can also be additionally stored in the expansion tank, so that, for example, sufficient coolant is available to flood several flooding areas essentially simultaneously.

[0011] In the motor vehicle, the flooding area may be part of a degassing channel of the battery storage unit.

[0012] In the motor vehicle, the coolant circuit along the battery storage unit can have at least one coolant channel that is in thermal communication with the battery storage unit and through which the coolant flows during operation. The switchable connecting means is connected to the coolant channel. This allows the coolant to flow from the coolant channel into the flooding area when the connecting means is open.

[0013] In the motor vehicle, at least one blocking device can be arranged along the coolant channel, which is designed to stop active flow through a partial area of ​​the coolant channel, such that a larger volume flow of coolant is directed through the flooding area. This makes it possible to deactivate individual areas or sectors of the coolant channel, so to speak, in order to be able to provide more coolant where a thermal event has occurred.

[0014] In the motor vehicle, the flooding area can be configured such that a flow and a return flow of coolant are formed, with at least one filter device being arranged downstream of the return flow of the flooding area in the coolant circuit. This makes it possible to keep the circulating coolant substantially free of contaminants that can arise during a thermal event, for example, in the degassing channel, and to flush coolant out of the flooding area. Thus, continued circulating operation of coolant is possible without, for example, adversely affecting a coolant pump or a heat exchanger through which coolant flows.

[0015] The motor vehicle may have a control unit that communicates with the coolant circuit, wherein the control unit is configured to flood the flooding area and include it in the actively flowing coolant circuit in the event of a thermally critical situation occurring in the battery storage unit or HV battery. For this purpose, for example, the temperature of the battery cell modules or the like can be monitored.

[0016] In the motor vehicle, the control unit can be configured to operate the coolant circuit with an adjustable cooling capacity, which is maximized in the event of a thermally critical situation. In other words, the coolant circuit can be operated at a low or medium power level. Upon the occurrence of a thermal event and the associated opening of at least one switchable connecting means, a coolant pump is operated at the maximum possible power or speed, so that a higher volume flow of coolant can be directed through the flooding area to achieve the desired cooling effect.

[0017] The coolant circuit can comprise, in a known manner, at least one coolant pump and at least one heat exchanger. The heat exchanger can, for example, be thermally coupled to a refrigeration system of the motor vehicle, in particular in the form of a so-called chiller. Alternatively, the heat exchanger can be designed as an air-cooled cooler. A combination of chiller and cooler is also possible, i.e., both heat exchangers can be connected in series or in parallel to each other and integrated into the cooling process simultaneously, should the thermal boundary conditions on the vehicle and in the environment result in an advantage for cooling the battery.

[0018] A coolant circuit as described above, which can be used as needed to flood and flow through flooding areas of the battery storage unit, also makes it possible to return to normal operation after a thermal event. For example, if a flooding area was previously flooded with coolant, the switchable connection can be closed again, so that no more coolant circulates in the flooding area, but the flooding area volume remains filled with coolant.

[0019] Furthermore, in the case of a motor vehicle as described above, a separate extinguishing device can also be provided or, if necessary, connected externally to the vehicle, i.e. the cooling circuit system, which is designed to trigger further measures if this is detected as necessary due to the thermal event and the parameters recorded in connection with it.

[0020] Further advantages and details of the invention will become apparent from the following description of embodiments with reference to the figures. Fig. 1 shows a simplified and schematic circuit diagram of a motor vehicle with a coolant circuit and a battery storage unit with an empty flooding area; Fig. 2 shows a simplified and schematic circuit diagram of a motor vehicle with a coolant circuit and a battery storage unit with a filled flooding area; Fig. 3 shows in a simplified and schematic circuit diagram similar to the Fig. 1 is a motor vehicle with a coolant circuit and a battery storage unit with an empty flooding area; Fig. 4 shows in a simplified and schematic circuit diagram similar to the Fig. 2 is a motor vehicle with a coolant circuit and a battery storage unit with a filled flooding area; Fig. 5 shows in a simplified and schematic circuit diagram similar to the Fig. 3 is a motor vehicle with a coolant circuit and a battery storage unit with an empty flooding area;

[0021] In Fig. 1 shows a simplified and schematic representation of a motor vehicle 10 as a dot-dash rectangle. The motor vehicle 10 has an at least partially electric drive, which in the Fig. 1 is not explicitly shown. Furthermore, the motor vehicle 10 comprises a battery storage unit 12 containing a plurality of battery cell modules 12m. The battery storage unit can also be referred to as an energy storage unit or high-voltage battery.

[0022] Each of the battery cell modules 12m comprises several battery cells 12z. In the example shown, the two exemplary battery cell modules 12m each have four battery cells 12z, purely for illustrative purposes.

[0023] The motor vehicle further comprises a coolant circuit 14, which is shown in a highly simplified manner and is designed with a minimal number of components and is in thermal connection with the battery storage unit 12. The coolant circuit comprises a coolant pump 16 and at least one heat exchanger 18. In the example shown, the Fig. 1, for the implementation of an active battery cooling concept, the heat exchanger 18 is thermally coupled to a refrigeration system 20 of the motor vehicle 10, shown here only in simplified form, so that heat can be transferred or exchanged between coolant in the coolant circuit 14 and refrigerant in the refrigeration system 20.

[0024] The coolant circuit 14 serves, in particular, to condition, in particular to cool, the battery storage unit 12 during operation of the motor vehicle 10. In the coolant circuit 14, the coolant circulates from the coolant pump 16 via the heat exchanger 18 to cooling elements 22-1, 22-2, for example, cooling channels or cooling plates or the like, which are in thermally operative connection with the battery storage unit 12.

[0025] Furthermore, an expansion tank 24 for coolant is arranged in the coolant circuit 14, so that the coolant circuit 14 can always be operated with optimal filling or under the most optimal conditions possible.

[0026] With reference to the Fig. 2, which is essentially identical to the Fig. 1, it can be seen that the battery storage unit has at least one flooding area 26 which is designed to be flooded with coolant from the coolant circuit 14. In this case, the flooding area 26 is free of coolant during normal operation, which is Fig. 1 is evident.

[0027] The flooding area 26 is assigned at least one switchable connecting means 28, which is closed during normal operation ( Fig. 1). The switchable connecting means 28 is connected to the coolant circuit 12 and is designed to be opened as required, such that the flooding area 26 is filled with coolant, is fluidically integrated into the coolant circuit 12 and is actively flowed through by coolant, which is Fig. 2 is evident.

[0028] In the Fig. In Figure 2, the filling or flooding of the flooding area 26 is illustrated by the dotted pattern in the left battery cell module 12m. This example also shows that two switchable connecting means 28 are assigned to the flooding area 26. According to the selected, simplified illustration, coolant flows into the flooding area 26 through the lower switchable connecting means 28 and leaves it via the upper switchable connecting means 28.

[0029] Downstream of the cooling element 22-1, a shut-off device 30 is arranged in the coolant circuit 12. The shut-off device 30 is open during normal operation so that the coolant can flow unhindered through the cooling element 22-1. The cooling element 22-2 is in the example of the Fig. 1 filled with coolant, but not actively flowing through.

[0030] To allow flow through the flooding area 26, the shut-off device 30 downstream of the cooling element 22-1 is closed. Accordingly, the coolant flows through the open switchable connecting means 28 and through the flooding area 26 into the (upper) outflow channel and / or the (upper) cooling element 22-2, and from there back to the coolant pump 16.

[0031] From the overview of the Fig. 1 and Fig. 2 it is evident that the expansion tank 24 has a volume that is oversized by at least one filling volume FV of the flooding area 26. In the Fig. 1, this filling volume FV is illustrated by the dotted pattern in the expansion tank 24. In the Fig. 2, the filling volume FV is taken from the expansion tank and circulates in the coolant circuit 14 through the flooding area 26 (dotted pattern).

[0032] The flooding area 26 can be part of a degassing channel of the battery storage unit 10, but this is not shown in detail here.

[0033] The above-mentioned shut-off element 30 can be understood as a blocking device that is designed to stop an active flow through the cooling element 22-1 or coolant channel, so that a larger volume flow of coolant is guided through the flooding area 26. In addition or as an alternative to the shut-off element 30, it is also conceivable that at least one further blocking device is arranged along the cooling element 22-1 or the coolant channel, which is designed to stop an active flow through a partial area or sector of the coolant channel. This is shown in the Fig. 2 simplified by two dotted shut-off devices 30s.

[0034] As can be seen from the overview of Fig. 1 and Fig. 2, the flooding region 26 with its two connecting means 28, which are connected to the cooling elements 22-1, 22-2, is designed such that a flow and a return flow of coolant are formed. Optionally, at least one filter device 32 can be arranged in the coolant circuit 14 downstream of the return flow of the flooding region 26, which in this example is formed by the upper connecting means 28 and the upper cooling element 22-2. Alternatively, a filter element 32 can also be arranged after the two cooling sections or cooling elements 22-1, 22-2 have been brought together. By means of such a filter device 32, particles potentially swept away from the flooding region 26 due to the flooding thereof can be retained, so that the coolant can continue to circulate even if at least one flooding region 26 is flooded, without these particles being carried along or trapped in the entire coolant circuit 14.distributed and may lead to cross-sectional constrictions and component damage elsewhere.

[0035] The Fig. 3 and Fig. 4 show a motor vehicle 10 with a substantially identical structure as in the Fig. 1 and Fig. 2. The only difference to the Fig. 1 and Fig. 2 is that the cooling elements 22-1, 22-2 or cooling channels of the battery storage unit 12 in normal operation ( Fig. 3) are flowed through by coolant in parallel and thus simultaneously, thus increasing the number of cooling channels of the energy storage device 12 to at least two. In the case of flooding of a flooding area 26 ( Fig. 4) the shut-off device 30 is also closed in this constellation, so that active flow through the flooding area 26 is possible, as already described above for the Fig. 2 has been described.

[0036] For more in the Fig. 3 and Fig. 4 components shown, refer to the above description of the Fig. 1 and Fig. 2.

[0037] In addition, it may prove advantageous to provide a further shut-off device (not shown) upstream of the cooling channel 22-2 or before the coolant enters the cooling channel 22-2, which shut-off device would be activated in particular in the event of flooding of a flooding area 26, in order to support or specifically achieve the forced flow through the flooding area 26.

[0038] Fig. 5 shows a Fig. 3 similar representation. In the Fig. 5 illustrates that the coolant circuit 14 may have a further heat exchanger 34. This may be a low-temperature cooler supplied with (ambient) air. Fig. 5 also shows that the heat exchanger 18 and the heat exchanger 34 can be selectively actively flowed through by coolant by means of corresponding shut-off devices 36a, 36b. In this context, it is conceivable, for example, that during normal operation, only one of the heat exchangers 18, 34 is used (actively flowed through by coolant) and the other heat exchanger 18, 34 is only integrated in the event of increased cooling requirements in the event of flooding of a flooding area 26.

[0039] Thus, in this case, the at least two heat exchangers 18, 34 can individually actively influence the cooling process of the coolant, but can also function in a coupled manner on the coolant, ie, depending on the selected integration concept, can be connected to one another in parallel or in series.

[0040] In all Fig.1 to 5 also show a control unit 40 that is communicatively connected to the coolant circuit 14 and configured to flood the flooding area 26 and include it in the actively flowing coolant circuit 14 in the event of a thermally critical situation occurring in the battery storage unit or HV battery 12. The control unit 40 is optionally configured to operate the coolant circuit 14 with an adjustable cooling capacity that is maximized in the event of a thermally critical situation. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 206 219 284 A1

[0003] DE 10 2012 215 736 A1

[0004] DE 44 458 20 A1

[0004] EP 1 693 632 A2

[0004]

Claims

[1] Motor vehicle (10) with an at least partially electric drive; a battery storage unit (12) containing a plurality of battery cell modules (12m); a coolant circuit (14) which is in thermal operative connection with the battery storage unit (12) in order to condition, in particular to cool, the battery storage unit (12) during operation of the motor vehicle (10); characterized by , that the battery storage unit (12) has at least one flooding area (26) which is designed to be flooded with coolant from the coolant circuit (14), wherein the flooding area (26) is free of coolant during normal operation of the battery storage unit (12), and that the flooding area (26) is assigned at least one switchable connecting means (28) which is closed during normal operation, wherein the switchable connecting means (28) is connected to the coolant circuit (14) and is designed to be opened as required, such that the flooding area (26) is filled with coolant, is fluidically incorporated into the coolant circuit (14) and is flowed through by coolant. [2] Motor vehicle (10) according to claim 1, characterized by that the coolant circuit (14) has an expansion tank (24) for coolant, wherein the volume of the expansion tank (24) is oversized by at least one filling volume (FV) of the flooding area (26). [3] Motor vehicle (10) according to claim 1 or 2, characterized by that the flooding area (26) is part of a degassing channel of the battery storage unit (12). [4] Motor vehicle (10) according to one of the preceding claims, characterized by that the coolant circuit (14) along the battery storage unit (12) has at least one coolant channel (22-1, 22-2) which is in thermal operative connection with the battery storage unit (12) and through which the coolant flows during normal operation, wherein the switchable connecting means (28) is connected to the coolant channel (22-1, 22-2). [5] Motor vehicle (10) according to claim 4, characterized by that at least one blocking device (30, 30s) is arranged along the coolant channel (22-1, 22-2), which is designed to stop an active flow through a partial region of the coolant channel (22-1, 22-2) in such a way that a larger volume flow of coolant is passed through the flooding region (26). [6] Motor vehicle (10) according to one of the preceding claims, characterized bythat the flooding region (26) is designed such that a flow and a return of coolant are formed, wherein at least one filter device (32) is arranged downstream of the return of the flooding region (26) in the coolant circuit (14). [7] Motor vehicle (10) according to one of the preceding claims, characterized by in that it has a control unit (40) which is in communication with the coolant circuit (14), wherein the control unit (40) is designed to cause flooding of the flooding region (26) and its inclusion in the actively flowing coolant circuit (14) in the event of a thermally critical situation occurring in the battery storage unit (12). [8] Motor vehicle (10) according to claim 7, characterized bythat the control unit (40) is designed to operate the coolant circuit (14) with an adjustable cooling capacity which is maximized in the event of a thermally critical situation.

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