Motor vehicle, in particular battery-electric motor vehicle, having a cooling circuit and cooling circuit for a motor vehicle

Abstract

In order to provide a motor vehicle, in particular a battery-electric motor vehicle, in which heat sources for controlling the temperature of the vehicle interior and the drive battery are used more efficiently and the production costs are reduced, a motor vehicle (100), in particular a battery-electric motor vehicle (10), comprising a drive battery (11), a vehicle interior (12), and a cooling circuit (200) is proposed, wherein the cooling circuit (200) is designed to control the temperature of the drive battery (11) and the vehicle interior (12), wherein the cooling circuit (200) has a battery heat exchanger (13), an interior heat exchanger (13), a chiller (15), a first heat source (16) and a first actuating device (17), wherein according to the invention the cooling circuit (200) can be switched by means of the first actuating device (17) in such a way that the first heat source (16) can be used selectively for selective or joint heating of the vehicle interior (12) and the drive battery (11).

Description

[0001] K 33772

[0002] Description

[0003] Motor vehicle, in particular battery-electric motor vehicle, with a cooling circuit and cooling circuit for a motor vehicle

[0004] The present invention relates to a motor vehicle, in particular a battery-electric motor vehicle, comprising a traction battery, a vehicle interior and a cooling circuit, wherein the cooling circuit is designed for temperature control of the traction battery and the vehicle interior, wherein the cooling circuit comprises a battery heat exchanger, an interior heat exchanger, a chiller, a first heat source and a first actuating device.

[0005] Furthermore, the present invention relates to a cooling circuit for a motor vehicle, in particular for a battery-electric motor vehicle.

[0006] Efficiency and range are essential characteristics of a battery-electric vehicle. Increasing efficiency directly benefits the driver in terms of running costs and range. The purchase price of battery-electric vehicles is comparatively high compared to conventional vehicles with combustion engines, making cost optimization desirable. Since battery-electric vehicles generate significantly less waste heat compared to combustion engine vehicles due to the high efficiency of their drive systems, it is particularly important to utilize all heat sources in battery-electric vehicles as effectively as possible.

[0007] From DE 10 2012 024 712 A1, a cooling circuit arrangement for a vehicle with an electric drive motor is known, wherein several components are arranged in a common cooling circuit. The components include at least the drive motor, an energy storage device, and a vehicle interior, and at least one control unit is provided by means of which heat flows in the cooling circuit between the components can be adjusted depending on a target temperature specified for each component. K 33772

[0008] - 2 -

[0009] DE 102014226 346 A1 discloses a heating system for electric or hybrid vehicles that can be operated in several operating modes and has a cooling circuit which includes a radiator and a heating heat exchanger for interior heating, which is connected in parallel to the radiator to form a heating circuit, wherein at least one heat source is arranged in the cooling circuit for heat transfer to the cooling circuit.

[0010] From DE 11 2012 001 744 B4, a vehicle temperature control device for temperature control of a temperature control object is known, which is at least one of the interior air of a vehicle interior and a vehicle component, a heat-capacitive element that is able to store or build up heat, a refrigeration circuit that absorbs heat from a low-temperature side and dissipates heat to a high-temperature side, a heat exchanger that enables the heat-capacitive element to exchange heat with the refrigerant of the refrigeration circuit, and a heat dissipation part that dissipates heat in the refrigerant of the refrigeration circuit to the temperature control object.

[0011] The present invention is based on the objective of providing a motor vehicle, in particular a battery-electric motor vehicle, in which heat sources for temperature control of the vehicle interior and the drive battery are used more efficiently and manufacturing costs are reduced.

[0012] To solve the problem underlying the invention, a motor vehicle, in particular a battery-electric motor vehicle, comprising a traction battery, a vehicle interior and a cooling circuit is proposed, wherein the cooling circuit is designed for temperature control of the traction battery and the vehicle interior, wherein the cooling circuit comprises a battery heat exchanger, an interior heat exchanger, a chiller, a first heat source and a first actuating device, wherein it is further provided that the cooling circuit can be switched by means of the first actuating device in such a way that the first heat source can be used selectively or jointly for heating the vehicle interior and the traction battery.

[0013] The battery heat exchanger can be part of the traction battery or integrated into it. The chiller advantageously serves for thermal coupling to a refrigerant circuit of the vehicle. This refrigerant circuit can be a compression refrigeration circuit and / or a heat pump circuit. K 33772

[0014] - 3 -

[0015] Preferably, the coolant in the cooling circuit is water.

[0016] The cooling circuit preferably includes coolant lines through which the coolant is conveyed to the components of the cooling circuit. The coolant lines can be assigned to individual coolant circuits.

[0017] According to the invention, the cooling circuit has a first actuating device by means of which the cooling circuit can be switched in such a way that the first heat source can be used either for selective or joint heating of the vehicle interior and the drive battery.

[0018] Compared to conventional vehicles with cooling systems that use separate heat sources for heating the vehicle interior and the traction battery, the option of selectively or simultaneously heating the vehicle interior and the traction battery reduces manufacturing costs for the cooling system. Furthermore, the heat from the first heat source can be used as needed to heat the vehicle interior or the traction battery, thereby increasing the efficiency of the vehicle's cooling system.

[0019] Preferably, the interior heat exchanger is a heating heat exchanger, and / or the first heat source is a high-voltage heater (HV heater), and / or the first actuating device is a valve, in particular a mixing valve and / or a multi-way valve, preferably a two-way valve, more preferably a three-way valve, and more preferably a four-way valve.

[0020] Since waste heat from a combustion engine cannot be utilized, particularly in battery-electric vehicles, the first heat source is advantageously designed as a high-voltage heater. By means of this first heat source, designed as a high-voltage heater, the vehicle interior and the traction battery can be heated selectively or simultaneously by appropriately switching the first actuator.

[0021] The first actuating device is preferably a multi-way valve, and particularly preferably a four-way valve. The multi-way valve allows coolant flow rates to be directed to the chiller, the first heat source, the drive battery, and K 33772.

[0022] - 4 - distributed throughout the vehicle interior, providing a high degree of freedom in the control of the coolant volume flows, thereby enabling a further increase in efficiency.

[0023] A further advantage is that the cooling circuit has at least a first coolant line and a second coolant line, and preferably a third coolant line, wherein the first coolant line and the second coolant line, and preferably the third coolant line, are connected in parallel, wherein coolant volume flows through the first coolant line and the second coolant line, and preferably the third coolant line, can be controlled by means of the first actuating device, wherein the chiller is arranged in the first coolant line, and wherein the first heat source and the interior heat exchanger are arranged in the second coolant line.

[0024] Preferably, depending on the position of the first actuator, a first operating mode and a second operating mode can be selected or set. In the first operating mode, the components are connected in the order of chiller and battery heat exchanger, viewed in the direction of coolant flow. In this first operating mode, the traction battery can be cooled by means of the chiller. If the chiller is coupled to a heat pump, the traction battery can be heated. In the second operating mode, the order of the components in the direction of coolant flow is the first heat source and battery heat exchanger. In this second operating mode, the traction battery can be heated by means of the heat generated by the first heat source.

[0025] Since the interior heat exchanger is also located in the second coolant circuit alongside the first heat source, the first heat source can also be used to heat the vehicle interior.

[0026] For this purpose, it is preferably provided that the second coolant line comprises a coolant line loop, wherein the first heat source and the interior heat exchanger are arranged in the coolant line loop.

[0027] Within the second coolant circuit, a partial cooling circuit is thus arranged, which includes the first heat source and the interior heat exchanger. By operating the K 33772

[0028] - 5 -

[0029] The coolant loop allows the heat from the first heat source to be used to heat the vehicle interior via the interior heat exchanger.

[0030] In particular, by appropriately configuring the first actuator, the first heat source can also be used in a third operating mode to simultaneously heat both the vehicle interior and the traction battery. For this purpose, the first actuator can be set such that the coolant flow rates are distributed between the first coolant circuit and / or the third coolant circuit, and the second coolant circuit.

[0031] When the first heat source is operating to warm the vehicle interior, the heated coolant can reach a very high temperature, which may be too high for warming the traction battery. Therefore, it is possible to use the first actuator to direct a portion of the coolant flow through the chiller via the first coolant circuit and a second portion through the first heat source via the second coolant circuit. With both coolant circuits operating simultaneously, the heat from the first heat source can thus be used to warm the vehicle interior. At the same time, a portion of the coolant heated by the first heat source can be combined with the coolant cooled by the chiller and used to warm the traction battery at more moderate temperatures.Furthermore, it is possible to use the first actuator to direct part of the coolant flow through the third coolant circuit and another part through the parallel second coolant circuit and the first heat source. If the coolant flowing through the third circuit is combined with the coolant heated by the second circuit and the first heat source, the temperature of the coolant used to heat the traction battery can also be lowered.

[0032] Preferably, a first pump and / or a check valve is arranged in the coolant loop.

[0033] In the direction of coolant flow within the coolant loop, the first pump is preferably located upstream of the interior heat exchanger, and the check valve is located downstream of the interior heat exchanger. The check valve allows, particularly in the third K 33772

[0034] - 6 -

[0035] The operating mode ensures a correct flow direction of the coolant in the coolant loop.

[0036] The pump serves, particularly in the third operating mode, to ensure a sufficient coolant flow rate through the interior heat exchanger.

[0037] With a further advantage, it can be provided that the cooling circuit includes a battery string, wherein the battery string is connected in series with the first coolant string and the second coolant string, and preferably the third coolant string, wherein the battery heat exchanger, and preferably a second pump, is arranged in the battery string.

[0038] Viewed in the direction of coolant flow, the sequence of components is therefore battery heat exchanger, first actuator, chiller in the first coolant line and / or heat source in the second coolant line, and / or third coolant line.

[0039] With a further advantage, the cooling circuit can be provided with a low-temperature coolant circuit (LT coolant circuit) and a second actuating device, wherein a low-temperature heat exchanger (LT heat exchanger) and a second heat source, and preferably a third pump, are arranged in the LT coolant circuit, wherein the LT coolant circuit has a bypass for the LT heat exchanger, wherein coolant volume flows through the LT heat exchanger and the bypass can be controlled by means of the second actuating device, so that the second heat source can be used to heat the vehicle interior.

[0040] The second heat source can include a drive system and / or power electronics and / or a control unit, in particular a central computer of the vehicle. In principle, the second heat source can also include other heat-generating components of the vehicle.

[0041] Furthermore, an onboard charging DC / DC converter (OCDC) may be installed in the NT coolant circuit in the case of a battery-electric vehicle. K 33772

[0042] - 7 -

[0043] The NT coolant circuit serves in particular to cool the second heat source, especially the drive, the electric machine and / or the power electronics of the motor vehicle.

[0044] In the preferred version, a bypass for the low-temperature heat exchanger is also provided. The second actuator can be switched in such a way that

[0045] Coolant flow rates can be split between the low-temperature heat exchanger and the bypass. This makes it possible to use the second heat source for temperature control or heating of the vehicle interior and / or the traction battery. For example, if a large proportion of the coolant flow, e.g., 100%, is directed to the bypass by means of the second actuator and, if necessary, a corresponding setting of the first actuator, then the sequence of components in the direction of coolant flow can be as follows: traction battery, first actuator, second actuator, bypass, second heat source, traction battery.

[0046] Furthermore, if the first pump is operated in the second coolant loop, then, with appropriate switching of the first actuator, the coolant heated by the second heat source can be partially or completely routed through the interior heat exchanger in a fourth operating mode.

[0047] Using the second heat source to warm the vehicle interior is particularly advantageous in the case of a so-called reheat. A reheat is a special operating mode for the interior temperature control of vehicles with multi-zone climate control. For example, if a low temperature is selected for the front passenger seats, the temperature for the rear passenger seats can be slightly raised by selectively supplying heat to the second climate zone. This increase in the temperature of the second climate zone is called a reheat.

[0048] Furthermore, it may be provided that the NT coolant line has a connecting cooling line, so that by switching the second actuating device, cooling of the second heat source via the NT heat exchanger can take place.

[0049] The NT coolant line can also be used to utilize heat from the outside environment. For this purpose, the second actuator can be switched such that the K 33772

[0050] - 8 -

[0051] The components are arranged in the following order: chiller, second actuator, low-temperature heat exchanger and / or bypass, second heat source, chiller. In principle, additional flow through the interior heat exchanger and / or the battery heat exchanger is also possible. In this configuration, heat absorbed from the outside environment and, if applicable, from the second heat source can be transferred to a refrigeration circuit thermally coupled to the chiller. The heat transferred to the refrigeration circuit can, for example, be used in an air conditioning system to heat the vehicle interior. Preferably, the temperature of the coolant heated in the low-temperature heat exchanger is below the temperature of the second heat source, so that the latter can also be cooled simultaneously.

[0052] By appropriately configuring the second actuator, the low-temperature (LT) coolant circuit can be partially or completely decoupled from the rest of the cooling system. For example, in a fifth operating mode, the coolant heated by the second heat source can be fed directly to the LT heat exchanger, and the coolant cooled by the LT heat exchanger can be returned to the second heat source. In this case, the LT coolant circuit serves exclusively to cool the second heat source, specifically the vehicle's drive system and power electronics. By appropriately configuring the second actuator and, if necessary, the first actuator, all combinations of the first, second, third, fourth, and fifth operating modes described above can also be enabled.

[0053] Another solution to the problem underlying the invention consists in providing a cooling circuit for a motor vehicle as described above.

[0054] All functions, features and designs explained in connection with the motor vehicle can also be transferred to the coolant circuit according to the invention in a correspondingly analogous manner.

[0055] The invention is explained in more detail below with reference to the accompanying figures. These show:

[0056] Fig. 1 schematically represents a motor vehicle with a cooling circuit. K 33772

[0057] - 9 -

[0058] Fig. 1 shows a schematic representation of a motor vehicle 100, which is designed as a battery-electric vehicle 10. The motor vehicle 100 comprises a cooling circuit 200, a traction battery 11, and a vehicle interior 12. The cooling circuit 200 is designed to regulate the temperature of the traction battery 11 and the vehicle interior 12 and includes a battery heat exchanger 13, an interior heat exchanger 14, a chiller 15, a first heat source 16, and a first actuator 17. The battery heat exchanger 13 is integrated into the traction battery 11. In the illustrated case, the first heat source 16 is designed as a high-voltage heater 18. The first actuator 17 is a four-way valve 19. The interior heat exchanger 14 is a heating heat exchanger 20.

[0059] The cooling circuit 200 comprises a first coolant line 21, a second coolant line 22, and a third coolant line 23, which are connected in parallel. The chiller 15 is located in the first coolant line 21. The second coolant line 22 includes a coolant loop 24, which in turn comprises the high-voltage heater 18 and the interior heat exchanger 14. A first pump 26 and a check valve 27 are also located in the coolant loop 24. Temperature sensors 25 may also be located in the cooling circuit 200.

[0060] The first coolant line 21, the second coolant line 22 and the third coolant line 23 are arranged in series with a battery coolant line 28 in which the battery heat exchanger 13 and a second pump 29 are arranged.

[0061] The cooling circuit 200 further comprises a low-temperature (LT) coolant line 30 and a second actuator 31, which is also designed as a four-way valve 19. The LT coolant line 30 includes a low-temperature heat exchanger 32, an expansion tank 33, a third pump 34, and a second heat source 35. The second heat source 35 comprises a drive unit (not shown in detail), in particular an electric motor, power electronics, and optionally an onboard charging DC / DC converter. The LT coolant line 30 includes a bypass 36 for the LT heat exchanger 32. The LT coolant line 30 also includes a connecting cooling line 37.

[0062] The first actuator 17 has connections A, B, C and D. The second actuator 31 has connections E, F, G and H. K 33772

[0063] - 10 -

[0064] The chiller 15 serves for thermal coupling with a refrigerant circuit of the motor vehicle 100 (not shown), which may be designed as a compression refrigeration circuit or heat pump circuit.

[0065] A variety of operating modes can be realized by switching the first actuator 17, the second actuator 31, the first pump 26, the second pump 29 and the third pump 34.

[0066] In a first operating mode, terminals A and B of the first actuator 17 are switched, so that, viewed in the direction of coolant flow, the components are connected in the sequence chiller 15 and battery heat exchanger 13. In this first operating mode, the traction battery 11 can thus be cooled by means of the chiller 15. If the chiller 15 is thermally coupled to a heat pump circuit, the traction battery 11 can be heated. Simultaneously, the first pump 26 can be operated and the vehicle interior 12 can be heated in the coolant loop 24, which in this case is largely decoupled from the rest of the cooling circuit.

[0067] In a second operating mode, terminals A and C are switched so that, viewed in the direction of coolant flow, the components are connected in the sequence first heat source 16 and battery heat exchanger 13. In the second battery mode, the traction battery 11 can thus be heated by means of the heat generated by the first heat source 16.

[0068] In a third operating mode, the first heat source 16 can be used simultaneously to heat the traction battery 11 and the vehicle interior 12. For this purpose, in one variant, terminals A and C of the first actuator 17 are switched and the first pump 26 is operated simultaneously. In the third operating mode, the coolant heated by the first heat source 16 can have a very high temperature, which may be too high for heating the traction battery 11. To lower the temperature of the coolant for heating the traction battery, in further variants of the third operating mode, terminals A, C, and D or A, B, and C can be switched, so that a portion of the coolant bypasses the first heat source 16 and is routed through the third coolant line 23 or the first coolant line 21 with the chiller 15. After merging with K 33772

[0069] - 11 - the coolant heated by the first heat source 16, the coolant for heating the drive battery 11 is at a lower temperature level.

[0070] The coolant flows can be controlled by means of the second actuator 31 such that the second heat source 35 can also be used in a fourth operating mode to heat the vehicle interior 12 and / or the traction battery 11. For this purpose, with appropriate switching of the first actuator 17, the terminals E and H of the second actuator 31 are switched, so that the coolant is routed via the bypass 36 and the second heat source 35 to the battery heat exchanger 13 and / or the interior heat exchanger 14. If necessary, the first pump 26 and the second pump 29 are operated to assist the distribution of the coolant via the battery heat exchanger 13 and the interior heat exchanger 14. Heating the vehicle interior 12 by means of the second heat source 35 is particularly advantageous for a reheat function.

[0071] In a fifth operating mode, by switching terminals F and G of the second actuator 31, the low-temperature coolant circuit 30 can be largely decoupled from the rest of the cooling circuit 200, so that the low-temperature coolant circuit 30 serves primarily to cool the drive, power electronics, and onboard charging DC / DC converter of the second heat source 35. Preferably, terminals G and H of the second actuator 31 are switched initially, so that the drive, power electronics, and onboard charging DC / DC converter of the second heat source 35 are first heated to operating temperature. As soon as a cooling request is issued by the second heat source 35, terminals F and G of the second actuator 31 are switched.

[0072] In principle, further operating modes or combinations of the operating modes described above can also be implemented by appropriately configuring the actuators 17, 31 and the pumps 26, 29 and 34. For example, it is possible to use waste heat from the drive battery 11 to defrost the low-temperature heat exchanger 32 by appropriately configuring the two actuators 17, 31.

[0073] The NT coolant line 30 can also be used to utilize heat from the outside environment. For this purpose, connections E and F of the second actuator 31 can be switched, so that the components are in the sequence chiller 15, second actuator 31, NT-K 33772.

[0074] - 12 -

[0075] The flow passes through heat exchanger 32 and / or bypass 36, second heat source 35, and chiller 15. In principle, by appropriately switching the first actuator 17 and, if applicable, the first pump 26 and / or the second pump 29, additional flow through the interior heat exchanger 14 and / or the battery heat exchanger 13 is also possible. In this operating mode, heat absorbed from the outside environment via the low-temperature heat exchanger 32 and, if applicable, from the second heat source 35 can be transferred to a refrigeration circuit thermally coupled to the chiller 15 and used, for example, in an air conditioning system for heating the vehicle interior 12.

[0076] K 33772

[0077] - 13 -

[0078] Reference symbol list

[0079] 100 motor vehicles

[0080] 200 Cooling circuit

[0081] 10 Battery-electric vehicle

[0082] 11 Drive battery

[0083] 12 Vehicle interior

[0084] 13 battery heat exchangers

[0085] 14 Interior heat exchangers

[0086] 15 Chiller

[0087] 16 First heat source

[0088] 17 First actuating device

[0089] 18 high-voltage heaters

[0090] 19 Four-way valve

[0091] 20 heating heat exchangers

[0092] 21 First coolant line

[0093] 22 Second coolant line

[0094] 23 Third coolant line

[0095] 24 Coolant circuit loop

[0096] 25 Temperature sensor

[0097] 26 First pump

[0098] 27 Check valve

[0099] 28 Battery cooling system

[0100] 29 Second pump

[0101] 30 NT coolant line

[0102] 31 Second actuating device

[0103] 32 NT heat exchangers

[0104] 33 expansion tanks

[0105] 34 Third Pump

[0106] 35 Second heat source

[0107] 36 Bypass

[0108] 37 Connecting cooling line

Claims

K 33772 Patent claims 1. Motor vehicle (100), in particular a battery-electric motor vehicle (10), comprising a traction battery (11), a vehicle interior (12), and a cooling circuit (200), wherein the cooling circuit (200) is designed for temperature control of the traction battery (11) and the vehicle interior (12), wherein the cooling circuit (200) comprises a battery heat exchanger (13), an interior heat exchanger (13), a chiller (15), a first heat source (16), and a first actuating device (17), characterized in that the cooling circuit (200) can be switched by means of the first actuating device (17) in such a way that the first heat source (16) can be used selectively or jointly for heating the vehicle interior (12) and the traction battery (11).

2. Motor vehicle (100) according to claim 1, characterized in that the interior heat exchanger (13) is a heating heat exchanger (20), and / or that the first heat source (16) is a high-voltage heater (18), and / or that the first actuating device (17) is a valve, in particular a mixing valve and / or a multi-way valve, preferably a two-way valve, more preferably a three-way valve, in particular preferably a four-way valve (19).

3. Motor vehicle (100) according to claim 1 or 2, characterized in that the cooling circuit (200) has at least a first coolant line (21) and a second coolant line (22), and preferably a third coolant line (23), wherein the first coolant line (21) and the second coolant line (22), and preferably the third coolant line (23), are connected in parallel, wherein coolant volume flows through the first coolant line (21) and the second coolant line (22), and preferably the third coolant line (23), are controllable by means of the first actuating device (17), wherein the chiller (15) is arranged in the first coolant line (21), and wherein the first heat source (16) and the interior heat exchanger (13) are arranged in the second coolant line (22).

4. Motor vehicle (100) according to claim 3, characterized in that the second coolant line (22) comprises a coolant line loop (24), wherein the first heat source (16) and the interior heat exchanger (13) are arranged in the coolant line loop (24). K 33772 - 2 - 5. Motor vehicle (100) according to claim 3 or 4, characterized in that a first pump (26) and / or a check valve (27) are arranged in the coolant loop (24).

6. Motor vehicle (100) according to one of claims 3 to 5, characterized in that the cooling circuit (200) comprises a battery string (28), wherein the battery string (28) is connected in series with the first coolant string (21) and the second coolant string (22), and preferably with the third coolant string (23), wherein the battery heat exchanger (13), and preferably a second pump (29), is arranged in the battery string (28).

7. Motor vehicle (100) according to claim 6, characterized in that the first actuating device (17) is arranged in the flow direction of a coolant behind the battery string (28) and in front of the first coolant string (21) and the second coolant string (22), and preferably in front of the third coolant string (23).

8. Motor vehicle (100) according to one of the preceding claims, characterized in that the cooling circuit (200) has a low-temperature coolant circuit (30) and a second actuating device (31), wherein a low-temperature heat exchanger (32) and a second heat source (35), in particular a drive or power electronics, and preferably a third pump (34), are arranged in the low-temperature coolant circuit (30), wherein the low-temperature coolant circuit (30) has a bypass (36) for the low-temperature heat exchanger (32), wherein coolant volume flows through the low-temperature heat exchanger (32) and the bypass (36) can be controlled by means of the second actuating device (31), so that the second heat source (35) can be used to heat the vehicle interior (12).

9. Motor vehicle (100) according to claim 8, characterized in that the NT coolant line (30) has a connecting cooling line (37) so that by switching the second actuating device (31) cooling of the second heat source (35) via the NT heat exchanger (32) can take place.

10. Cooling circuit (200) for a motor vehicle (100) according to one of the aforementioned claims.

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