DE102021207249A1 - Thermal management system for a battery in a motor vehicle and motor vehicle with a thermal management system - Google Patents

Abstract

In order to provide a thermal management system for a motor vehicle, in particular for a battery-electric vehicle, which has a significant reduction in complexity and efficiency advantages over known thermal management systems, a thermal management system (100) for a battery (10) of a motor vehicle, in particular a battery-electric vehicle, is comprehensive a coolant circuit (11), wherein a battery (10), a refrigeration machine (12), an auxiliary heating device (13) and a fluid control device (14, 14a, 14b) are arranged in the coolant circuit (11), it being further provided that the fluid control device (14, 14a, 14b) is designed to divide a volume flow of a coolant emerging from the auxiliary heating device (13) into the refrigerating machine (12) and/or the battery (10) as required.

Description

The present invention relates to a thermal management system for a battery of a motor vehicle, in particular a battery-electric vehicle, comprising a coolant circuit, a battery, a refrigerator, an auxiliary heating device and a fluid control device being arranged in the coolant circuit.

Furthermore, the present invention relates to a motor vehicle with a thermal management system.

Thermal management systems are used to cool or heat the battery of a motor vehicle, in particular the battery of a battery-electric vehicle. The battery is in particular the energy store for operating the drive motors. In battery electric vehicles in particular, the requirements for the thermal management system are diverse and complex. Such thermal management systems are often thermally connected to other cooling or refrigerant circuits, for example to a refrigerant circuit for temperature control of a vehicle interior.

The use of auxiliary heating devices, in particular PTC auxiliary heaters, is known in the known thermal management systems. In the prior art, these auxiliary heating devices are arranged on the sink side or hot side of a heat pump and thus in the cooling or refrigerant circuit for temperature control of the vehicle interior. A disadvantage of arranging an auxiliary heating device on the hot side, for example in a cooling or refrigerant circuit for temperature control of a vehicle interior, is that sharing the auxiliary heating device for the battery and the vehicle interior is lossy because it is in the components and the cooling or refrigerant lines a higher temperature level prevails.

From the CN111516556A1 a thermal management system for a purely electric vehicle is known. The system includes a heating system, a power system, a power system cooling system, and a battery cooling system. A four-way valve is arranged between the power system cooling system and the heating system to connect the two circuits. A high-voltage electric heater can be used entirely to heat the passenger compartment and battery.

the CN109572365A1 discloses a thermal management system of a hybrid electric vehicle. According to the thermal management system of the hybrid electric vehicle, using two four-way valves, an engine cooling system, an intercooling system, a heating system, a power system cooling system, a battery cooling system, and an air conditioning system are integrated into a more efficient system.

From the CN110481271A1 a thermal management system for pure electric vehicles is known that includes a heating loop, a power system cooling loop, and a battery cooling loop. A three-way valve is placed between the power system cooling loop and the battery cooling loop to connect the two circuits.

the CN110949182A1 discloses an electric vehicle thermal management system having a battery control loop and a power system control loop. The battery control loop is coupled to a battery pack of the electric vehicle. The power system control circuit includes a main path, a first branch path and a second branch path, wherein heat transfer fluid in the power system control circuit can flow from the main path into the first branch path and the second branch path and finally flow back to the main path. A radiator is arranged in the main path.

the CN112109521A1 discloses a vehicle thermal management system for an all-electric vehicle. The thermal management system comprises a refrigerant circuit, a warm air-water system circuit, a battery-water system circuit, an engine-water system circuit, a water-cooled condenser for coupling the refrigerant circuit with the warm air-water system circuit, a chiller for coupling the refrigerant circuit with the Battery water system circuit and a four-way valve for coupling the battery water system circuit with the engine water system circuit.

The object of the present invention is to provide a thermal management system for a motor vehicle, in particular for a battery-electric vehicle, which has a significant reduction in complexity and efficiency advantages compared to known thermal management systems.

In order to achieve the object on which the invention is based, a thermal management system for a battery of a motor vehicle, in particular a battery-electric vehicle, is proposed, comprising a coolant circuit, a battery, a refrigerating machine, an auxiliary heating device and a fluid control device being arranged in the coolant circuit, it also being provided that the fluid control device is designed to require a volume flow of a coolant emerging from the auxiliary heating device depending on the chiller and/or the battery.

The battery can be the primary source of energy for operating the traction motors of a battery electric vehicle. The refrigeration machine is also referred to as a chiller and preferably represents the thermal connection to an additional cooling or refrigerant circuit required for the temperature control of a vehicle interior.

The fluid control device is designed to divide a volume flow of the coolant between the refrigerating machine and the battery. This means in particular that 100% of the volume flow can be supplied to either the refrigeration machine or the battery by means of the fluid control device. Furthermore, the volume flow of the coolant can also be divided proportionately between the battery and the refrigerating machine by means of the fluid control device.

According to the invention it is provided that the auxiliary heating device is arranged in the coolant circuit of the thermal management system. Compared to the prior art, in which the auxiliary heating device is on the sink side or on the hot side of the refrigeration machine, which is used to control the temperature of the passenger compartment, in the present invention the auxiliary heating device is arranged on the source side or cold side of the refrigeration machine. The auxiliary heating device can therefore be used both for temperature control of the battery and, via the refrigeration machine, for temperature control of the vehicle interior. This is made possible in particular by the fact that, by means of the fluid control device, the volume flow of the coolant can be divided between the refrigerating machine and/or the battery as required.

It is advantageously provided that the cooling machine is a chiller and/or that the auxiliary heating device is an electrical auxiliary heating device, preferably a high-voltage heater, more preferably a PTC auxiliary heater.

With a further advantage it can be provided that the fluid control device is a valve, in particular a three-way valve or a four-way valve.

With a further advantage, it can be provided that the coolant circuit has a branch into a first coolant line and a second coolant line downstream of the auxiliary heating device in the flow direction of the coolant, with the refrigeration machine being arranged in the first coolant line.

Provision is also preferably made for the first coolant line and the second coolant line to be connected to the fluid control device and to be combined into a third coolant line by means of the fluid control device, with the auxiliary heating device being arranged in the third coolant line.

In other words, a coolant flows through the auxiliary heating device in the direction of flow and is then divided by the branching into a first coolant line and a second coolant line. The first coolant line and the second coolant line are in turn combined by means of the fluid control device to form the third coolant line, in which the auxiliary heating device is located. The third coolant line runs from the fluid control device to the junction.

It is preferably provided that a switching device, in particular a switching valve, is provided in the third coolant line, with the switching device being designed to direct a volume flow of the coolant into a fourth coolant line, with the fourth coolant line being connected to the first coolant line between the refrigeration machine and the fluid control device is fluidly connected.

With yet another advantage, it can be provided that a pump is arranged in the third coolant line.

Furthermore, it is preferably provided that the battery is arranged in the third coolant line.

The battery is therefore preferably located in the coolant line in which the auxiliary heating device is also located. The battery can be arranged in the direction of flow before the auxiliary heating device, and more preferably before the switching device, in the third coolant line. In this embodiment, the volume flow of the coolant can be distributed by the fluid control device in such a way that the battery can be heated and cooled. If, for example, the first coolant line and the third coolant line are fluidically connected to one another by means of the fluid control device and the second coolant line is fluidically separated from the third coolant line, then by operating the auxiliary heating device, a heated coolant exiting the auxiliary heating device can flow through the branch and the refrigeration machine via the fluid control device of the battery be supplied. If the refrigeration machine is not in operation, the battery can be heated or warmed up. In addition, the refrigeration machine can be raised to a higher level by means of the auxiliary heating device in the same way Temperature level are raised, so that a heat transfer from the thermal management system via the chiller in another cooling or refrigerant circuit for temperature control of a passenger compartment can be done more efficiently. The passenger compartment can consequently be heated by means of the auxiliary heating device in the coolant circuit of the thermal management system. If the auxiliary heating device is not operated with the fluid control device in the same position, the battery can be cooled by operating the refrigerating machine. If, on the other hand, the second coolant line and the third coolant line are fluidically connected by means of the fluid control device and the third coolant line is fluidically separated from the first coolant line, a coolant heated by the auxiliary heating device can be fed directly to the battery via the branch and the second coolant line, and the battery can thus be heated.

Provision is preferably made for the third coolant line to have a bypass to the battery, the bypass being fluidically connected to the fluid control device, the fluid control device being designed to divide a volume flow of the coolant between the battery and the bypass as required.

A coolant heated by the auxiliary heating device can be routed past the battery by means of the bypass. This is particularly advantageous when the auxiliary heating device is used to control the temperature of the refrigerating machine, but the battery does not require heating.

With a further advantage, it can be provided that the battery is arranged in the second coolant line, with the second coolant line preferably having a fifth coolant line, with the fifth coolant line being arranged in a parallel connection to the battery, with the fifth coolant line having a pump and a check valve .

By arranging the battery in the second coolant line, the coolant heated by the auxiliary heating device can be divided between the refrigerating machine and the battery as required by the position of the fluid control device. Furthermore, the battery can also be cooled by means of the refrigerating machine. This is achieved in that a volume flow of the coolant is diverted into the fourth coolant line and fed to the refrigerating machine by means of the switching device arranged in the third coolant line. The coolant cooled by the refrigeration machine then flows in the opposite direction to the direction of flow provided when the refrigeration machine is heated in the first coolant line and via the branching into the second coolant line, in order to cool the battery there.

The fifth coolant line is connected in parallel to the battery. A small coolant circuit through the battery and the fifth coolant line can be provided by the pump and the check valve in the fifth coolant line. This is particularly advantageous when the battery has neither a cooling nor a heating requirement. By operating the small coolant circuit with the fifth coolant line, temperature balancing for the battery, ie a reduction in the temperature gradient within the battery, can be carried out. In this case, the first coolant line and the third coolant line can be fluidically connected by means of the fluid control device and the second coolant line with the battery can be separated from the third coolant line. The additional heating device is then used exclusively for temperature control of the refrigeration machine on the source side.

With yet another advantage, it can be provided that the coolant circuit is fluidically connected to a second coolant circuit, the second coolant circuit being designed for cooling traction components of a motor vehicle.

For example, the second coolant circuit can include an electric motor, power electronics and/or a low-temperature cooler. In addition, the second coolant circuit can have a pump and a second switching valve. Such coolant circuits are known in the prior art and can be connected to the proposed thermal management system in a manner known to those skilled in the art.

There is preferably a branch in the fourth coolant line, via which the second coolant circuit can be supplied with coolant from the coolant circuit of the thermal management system. In addition, it is preferably provided that a further branch is provided in the first coolant branch in the direction of flow upstream of the refrigeration machine, via which a coolant from the second coolant circuit can be supplied to the coolant circuit of the thermal management system. A switching valve or another fluid control device can be provided in the second coolant circuit for controlling the inflow and outflow from the second coolant circuit to the coolant circuit of the thermal management system.

A further solution to the problem on which the invention is based consists in providing a motor vehicle with a thermal management system as described above.

The invention is explained in more detail below with reference to the accompanying figures.

• 1 eine erste Ausführungsform eines Thermomanagementsystems,
• 2 eine zweite Ausführungsform eines Thermomanagementsystems, und
• 3 eine dritte Ausführungsform eines Thermomanagementsystems.

Show it:

• 1 a first embodiment of a thermal management system,
• 2 a second embodiment of a thermal management system, and
• 3 a third embodiment of a thermal management system.

In the figures, elements that are the same or that correspond to one another are identified by the same reference symbols.

1 shows a thermal management system 100 for a battery 10 of a battery-electric vehicle, not shown in detail. The thermal management system 100 comprises a coolant circuit 11, a battery 10, a refrigerating machine 12, also called a chiller, an auxiliary heating device 13 and a fluid control device 14 being arranged in the coolant circuit 11. The fluid control device 14 is designed as a three-way valve 14a. A branch 15 is provided downstream of the auxiliary heating device 13 in the flow direction and divides the volume flow of a coolant into a first coolant line 16 and a second coolant line 17 . The refrigerating machine 12 is arranged in the first coolant line 16 . The first coolant line 16 and the second coolant line 17 are brought together in a third coolant line 18 via the fluid control device 14 , the battery 10 and the auxiliary heating device 13 being arranged in the third coolant line 18 . The volume flow of the coolant in the coolant circuit 11 can be divided between the first coolant line 16 and the second coolant line 17 by means of the fluid control device 14 . Furthermore, a switching device 19, in particular a switching valve 19a, is arranged in the third coolant line 18, which can supply a volume flow from the third coolant line 18 to a fourth coolant line 20. The fourth coolant line 20 is connected to the first coolant line 16 via a further branch 21 downstream of the refrigerating machine 12 in the direction of flow. In the fourth coolant line 20 there is also a further branch 22 via which the thermal management system 100 or its coolant circuit 11 is fluidly connected to a second coolant circuit 23 known per se. In addition, there is a further branch 24 in the first coolant line 16 between the branch 15 and the refrigeration machine 12, via which the second coolant circuit 23 is coupled to the first coolant circuit 11. The second coolant circuit 23 can be configured in a manner known to those skilled in the art. In the case shown, the second coolant circuit 23 includes an electric motor 25, power electronics 26 and a low-temperature cooler 27. In the second coolant circuit 23, a pump 28 and a switching valve 29 are also arranged. A coolant exchange between the first coolant circuit 11 and the second coolant circuit 23 can be adjusted by means of the switching valve 29 . A pump 30 is also arranged in the coolant circuit 11 of the thermal management system 100 . The battery 10 can be both heated and cooled with the thermal management system 100 . In addition, the cooling machine 12 can be raised to a higher temperature level by means of the auxiliary heating device 13 . The cooling machine 12 is preferably connected with its sink or hot side to a cooling or refrigerant circuit, not shown, for the temperature control of a passenger compartment.

If the first coolant line 16 and the third coolant line 18 are connected by means of the fluid control device 14 and the second coolant line 17 is separated from the third coolant line 18, then both the refrigeration machine 12 and the battery can be raised to a higher temperature level by operating the auxiliary heating device 13 10 to be heated. If the auxiliary heating device 13 is not operated, the battery 10 can be cooled by operating the refrigerating machine 12 by means of the coolant routed through the first coolant line 16 and the third coolant line 18 . If only the battery 10 needs to be heated, the first coolant line 16 can be separated from the third coolant line 18 by means of the fluid control device 14 and the second coolant line 17 can be connected to the third coolant line 18 . In this case, the coolant heated by the auxiliary heating device 13 flows directly into the battery 10 without passing through the refrigerating machine 12 and can be used to heat the battery 10 .

In 2 is a variant of the thermal management system 100 according to 1 shown. Compared to the thermal management system 100 of 1 a bypass 31 is also provided, which is connected to a fluid control device 14 designed as a four-way valve 14b. A volume flow of the coolant can be routed past the battery 10 by means of the bypass 31 . This is particularly advantageous when the auxiliary heating device 13 is used exclusively to increase the temperature level of the refrigerating machine 12 . In order to prevent the battery 10 from heating up, the heated coolant flowing out of the auxiliary heating device 13 through the branch 15 into the first coolant line 16 and through the refrigerating machine 12 can be routed past the battery 10 by means of the bypass 31 .

3 shows another variant of the thermal management system 100. In the variant 3 the battery 10 is arranged in the second coolant line 17 . A fifth coolant line 32 is provided parallel to the battery 10 , a further pump 33 and a check valve 34 being located in the fifth coolant line 32 . The fluid control device 14 is as in the variant shown in FIG 1 designed as a three-way valve 14a. By operating the auxiliary heating device 13 and setting the fluid control device 14 accordingly, the coolant heated by the auxiliary heating device 13 can be fed both to the refrigerating machine 12 to raise its temperature level and to the battery 10 . The thermal management system 100 after 3 can also be operated in a cooling mode for the battery 10. In this case, the second coolant line 17 is connected to the third coolant line 18 by means of the fluid control device 14 . Furthermore, a volume flow of the coolant from the third coolant line 18 into the fourth coolant line 20 is conducted by means of the switching device 19 . The coolant flowing through the fourth coolant line 20 is routed via the branch 21 into the refrigerating machine 12 and from there into the battery 10 . If the third coolant line 18 is fluidically connected to the first coolant line 16 and fluidly separated from the second coolant line 17 by means of the fluid control device 14, the auxiliary heating device 13 is used exclusively to raise the refrigerating machine 12 to a higher temperature level. This case makes sense when the battery 10 has neither a cooling nor a heating requirement. In this case, it can also be provided that the fifth coolant line 32 is operated by operating the pump 33 so that a coolant flows in a circuit through the battery 10 and the fifth coolant line 32 . A temperature gradient within the battery 10 can thereby be reduced.

reference list

100

thermal management system

10

battery

11

coolant circuit

12

chiller

13

auxiliary heating device

14

fluid control device

14a

three-way valve

14b

four-way valve

15

branch

16

First line of coolant

17

Second line of coolant

18

Third line of coolant

19

switching device

19a

switching valve

20

Fourth line of coolant

21

branch

22

branch

23

Second coolant circuit

24

branch

25

electric motor

26

power electronics

27

low temperature cooler

28

pump

29

switching valve

30

pump

31

bypass

32

Fifth line of coolant

33

pump

34

check valve

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• CN111516556A1 [0005]
• CN 109572365 A1 [0006]
• CN110481271A1 [0007]
• CN 110949182 A1 [0008]
• CN 112109521 A1 [0009]

Claims (10)

Thermal management system (100) for a battery (10) of a motor vehicle, in particular a battery-electric vehicle, comprising a coolant circuit (11), with a battery (10), a refrigerator (12), an auxiliary heating device (13) and a fluid control device (14, 14a, 14b) are arranged, characterized in that the fluid control device (14, 14a, 14b) is designed to direct a volume flow of a coolant emerging from the auxiliary heating device (13) to the refrigerating machine (12) and/or the Divide battery (10). Thermal management system (100) according to claim 1 , characterized in that the cooling machine (12) is a chiller and/or that the auxiliary heating device (13) is an electrical auxiliary heating device, preferably a high-voltage heater, more preferably a PTC auxiliary heater, and/or that the fluid control device (14, 14a , 14b) is a valve, in particular a three-way valve (14a) or a four-way valve (14b). Thermal management system (100) according to claim 1 or 2 , characterized in that the coolant circuit (11) has a branch (15) into a first coolant line (16) and a second coolant line (17) downstream of the auxiliary heating device (13) in the direction of flow of the coolant, with the refrigeration machine (12) in the first Coolant line (16) is arranged. Thermal management system (100) according to claim 3 , characterized in that the first coolant line (16) and the second coolant line (17) are connected to the fluid control device (14, 14a, 14b) and are combined into a third coolant line (18) by means of the fluid control device (14, 14a, 14b). be, wherein the auxiliary heating device (13) is arranged in the third coolant line (18). Thermal management system (100) according to claim 4 , characterized in that a switching device (19, 19a), in particular a switching valve (19a), is provided in the third coolant line (18), the switching device (19, 19a) being designed to control a volume flow of the coolant into a fourth coolant line ( 20), wherein the fourth coolant line (20) is fluidically connected to the first coolant line (16) between the refrigeration machine (12) and the fluid control device (14, 14a, 14b). Thermal management system (100) according to claim 4 or 5 , characterized in that a pump (30) is arranged in the third coolant line (18) and/or that the battery (10) is arranged in the third coolant line (18). Thermal management system (100) according to one of Claims 4 until 6 , characterized in that the third coolant line (18) has a bypass (31) to the battery (10), the bypass (31) being fluidically connected to the fluid control device (14, 14b), the fluid control device (14, 14b) being formed is to divide a volume flow of the coolant between the battery (10) and the bypass (31) as required. Thermal management system (100) according to one of claims 3 until 7 , characterized in that the battery (10) is arranged in the second coolant line (17), the second coolant line (17) preferably having a fifth coolant line (32), the fifth coolant line (32) being connected in parallel to the battery ( 10) is arranged, wherein the fifth coolant line (32) has a pump (33) and a check valve (34). Thermal management system (100) according to one of the preceding claims, characterized in that the coolant circuit (11) is fluidically connected to a second coolant circuit (23), the second coolant circuit (23) being designed to cool traction components of a motor vehicle. Motor vehicle with a thermal management system (100) according to one of the preceding claims.

Images