CN112895843A

CN112895843A - Thermal management system for a motor vehicle and motor vehicle having such a thermal management system

Info

Publication number: CN112895843A
Application number: CN202011214632.XA
Authority: CN
Inventors: M·莫泽
Original assignee: Bayerische Motoren Werke AG
Current assignee: Bayerische Motoren Werke AG
Priority date: 2019-12-03
Filing date: 2020-11-04
Publication date: 2021-06-04
Also published as: DE102019132816A1

Abstract

The invention relates to a thermal management system for a motor vehicle, comprising: a motor cooling circuit (1) in which an electric drive device (2), a refrigerator circuit branch point (3), a cooler (4), and a motor circuit pump (6) are provided; a refrigerator line (7) having a refrigerator (8), which branches off from the motor cooling circuit at a refrigerator line branching point and opens into the motor cooling circuit at a point between the cooler and the motor circuit pump; and a heating circuit (15) having an interior heat exchanger (20), which branches off from the motor cooling circuit at a point between the motor circuit pump and the electric drive and opens into the motor cooling circuit at a point between the freezer circuit branch point and the cooler. The invention further relates to a motor vehicle having such a thermal management system.

Description

Thermal management system for a motor vehicle and motor vehicle having such a thermal management system

Technical Field

The invention relates to a thermal management system for a motor vehicle and to a motor vehicle having such a thermal management system.

Background

Thermal management systems for electrified motor vehicles are known which provide thermal power to the vehicle interior by means of a heat pump function in which existing heat sources, such as electric motors and high-pressure accumulators, are utilized. In this regard, it is always desirable to design thermal management systems to more efficiently and effectively utilize the available heat sources, since the increase in efficiency directly improves the range of the vehicle in heating operation.

An alternative thermal management system is described in unpublished german patent application 102019120229.9. In this heat management system, however, the heating line branches into the motor cooling circuit upstream of the refrigerator line branch point.

Disclosure of Invention

The object of the invention is therefore to increase the efficiency of a thermal management system. This object is achieved by a thermal management system according to claim 1 and a motor vehicle according to claim 9. Advantageous embodiments of the invention are the subject matter of the dependent claims.

According to an embodiment of the present invention, there is provided a thermal management system for a motor vehicle, the thermal management system comprising: a motor cooling circuit in which an electric drive device, a refrigerator line branch point, a cooler, and a motor circuit pump are provided; a chiller line having a chiller that branches off from the motor cooling circuit at a chiller line branching point and opens into the motor cooling circuit at a location between the chiller and the motor circuit pump; and a heating circuit with an internal space heat exchanger, which branches off from the motor cooling circuit at a point between the motor circuit pump and the electric drive and opens into the motor cooling circuit at a point between the freezer circuit branch point and the cooler. The advantages of this embodiment are: the thermal management system can be implemented with as few valves as possible. As a result, the thermal management system can be produced more cost-effectively than the systems known from the prior art. In addition, the interconnection of the heating and cooling circuits of this embodiment allows waste heat of the electric drive to be introduced into the chiller and/or into the accumulator bypassing the cooler. Thereby, no heat loss occurs at the cooler, thereby providing a more efficient thermal management system in the heating operation (heating of the accumulator and/or heating operation by the freezer).

According to another embodiment of the invention, the thermal management system is further equipped with a motor-chiller circuit in which the electric drive, the chiller and a motor-circuit pump are arranged, said motor-chiller circuit leading from the chiller to the motor-circuit pump bypassing the cooler.

According to another embodiment of the invention, the thermal management system is further equipped with an AC circuit having a heating circuit, a cooler, and a motor circuit pump.

According to another embodiment of the invention, the thermal management system is further equipped with an HVS-chiller circuit having a chiller and an electrical energy accumulator.

According to another embodiment of the invention, the thermal management system is further provided with a heating circuit having an inner space heat exchanger and an electric heater.

According to a further embodiment of the invention, the thermal management system is further equipped with a refrigeration circuit having a refrigerating machine which can be traversed by the refrigerant of the refrigeration circuit and which can be traversed by the coolant of the motor cooling circuit and/or of the motor-refrigerating circuit in a fluid-separated manner from the refrigerant of the refrigeration circuit, an air-conditioning evaporator and a water-cooled condenser, and the air-conditioning evaporator is arranged in an air guiding device by means of which air can be guided into the passenger compartment of the vehicle.

According to a further embodiment of the invention, the electric drive has at least one electric motor for driving the motor vehicle.

According to a further exemplary embodiment of the invention, the electric drive also has an inverter, a dc converter, a battery control device and/or a vehicle internal charger.

The invention further relates to a motor vehicle having such a thermal management system.

Drawings

Preferred embodiments of the present invention are described below with reference to the accompanying drawings. In the drawings:

figure 1 schematically shows a heating and cooling circuit of a thermal management system according to a first embodiment of the invention;

FIG. 2 schematically illustrates a refrigeration circuit of a thermal management system according to an embodiment of the present invention; and

figure 3 schematically shows a heating and cooling circuit of a thermal management system according to a second embodiment of the invention.

Detailed Description

FIG. 1 schematically illustrates heating and cooling circuits of a thermal management system according to an embodiment of the invention. The thermal management system is preferably installed in a motor vehicle, not shown, in particular a passenger car, such as an electric vehicle. The heating and cooling circuit of the thermal management system comprises a motor cooling circuit 1 in which an electric drive 2 is arranged for driving the motor vehicle. The electric drive 2 has at least one electric motor. In the case of a plurality of electric motors, these can be traversed in parallel with one another by the motor cooling circuit 1, for which purpose the motor cooling circuit 1 branches into parallel lines upstream of the electric motors, which lines merge again downstream of the electric motors. Furthermore, the electric drive 2 may also have power electronics, such as an inverter, a dc converter, a battery control and an on-board charger, which are associated with the electric motor. Downstream of the electric drive 2, a refrigerating machine line branching point 3 with a refrigerating machine valve 3a, a cooler 4, a compensation tank 5 and a motor circuit pump 6 are provided. The cooler 4 is arranged to be traversed by ambient air, so that it can be cooled by the driving wind. The cooler is provided with a blower for conveying air in addition to the running wind so that the air flows through the cooler. The compensating tank 5 may also be mounted elsewhere in the heating and cooling circuit and/or more than one compensating tank may be provided.

A coolant, such as water doped with additives, may be circulated in the motor cooling circuit 1. The through-flow of the cooler 4 can be allowed or prevented by means of the freezer valve 3a at the freezer line branching point 3, wherein intermediate positions of the freezer valve 3a are also possible. For example, when the motor cooling circuit 1 is in operation, with the freezer valve 3a open and the motor circuit pump 6 activated, the coolant circulates in the motor cooling circuit 1 in such a way that the series connection (in particular in this order) comprising the electric drive 2, the freezer valve 3a, the cooler 4, the motor circuit pump 6 and back again to the electric drive 2 is traversed. In the context of the present description, the terms "upstream" and "downstream" relate to the flow direction of the coolant or the refrigerant mentioned later when the thermal management system is in operation.

At the chiller line branching point 3, the chiller line 7 branches off from the motor cooling circuit 1, so that the flow through the chiller line 7 and the cooler 4 is allowed or prevented by means of the chiller valve 3a, wherein intermediate positions are also possible. The freezer valve 3a is in particular designed as a two-position three-way valve, but instead of a two-position three-way valve, one or more further valves, for example two (or three) shut-off valves, can also be provided.

The chiller circuit 7 has a chiller 8 and opens into the motor cooling circuit 1 again downstream of the chiller 8, more precisely upstream of the motor circuit pump 6 or between the cooler 4 and the motor circuit pump 6. The freezer 8 is a heat exchanger which transfers thermal energy between the heating and cooling circuit shown in fig. 1, more precisely the freezer circuit 7, and a refrigeration circuit 30 explained later.

An HVS line, in which an HVS pump 9, an HVS valve 10, an electrical energy accumulator 11, a non-return valve 12 or a non-return valve is arranged, branches off between the refrigerating machine 8 and the inlet of the refrigerating machine line 7 into the motor cooling circuit 1. The HVS line passes back into the freezer line 7 at a point between the freezer line branch point 3 and the freezer 8.

The HVS pump 9 is, for example, an electric pump, which in particular has a variable delivery volume. The HVS valve 10 is a shut-off valve, through which a flow through the electrical energy accumulator 11 can be allowed or prevented, wherein intermediate positions are also possible, so that the flow rate can be adjusted. The electrical energy accumulator 11 is a rechargeable battery having a plurality of storage cells which store and supply energy for driving the vehicle. When passing through the electrical energy accumulator 11, more precisely the temperature control unit of the electrical energy accumulator 11, the temperature control unit is adapted to introduce thermal energy into the storage cells and/or to discharge thermal energy.

Thus, when the HVS valve 10 is open and the HVS pump 9 is activated, a HVS-chiller circuit 13 can be constituted, which is shown in dashed lines in fig. 1. In this HVS-chiller circuit 13, the HVS pump 9, the HVS valve 10, the electrical energy accumulator 11, the non-return valve 12 and the chiller 8 are arranged in series in the circuit, for example in the stated order, and can be traversed by the coolant.

If the chiller valve 3a prevents the through-flow of the chiller line 7 during operation of the HVS-chiller circuit 13, the coolant circulates in the HVS-chiller circuit 13 without coolant flowing from the chiller line branch point 3 into the chiller line 7 and without coolant flowing from the chiller line 7 out into the motor cooling circuit 1.

By forming the HVS-chiller circuit 13, coolant is conveyed from the accumulator 11 to the chiller 8 by means of the activated HVS pump 9 and the waste heat of the accumulator 11 is thus fed into the chiller 8. After flowing through the chiller 8, the HVS pump 9 delivers coolant back to the accumulator 11, etc.

If the chiller valve 3a opens the through-flow of the chiller line 7 during operation of the HVS-chiller circuit 13, the coolant circulates in the HVS-chiller circuit 13, while the coolant flows from the chiller line branch point 3 into the chiller line 7 and the coolant flows from the chiller line 7 out into the motor cooling circuit 1. This additionally forms a motor-chiller circuit 14, which is shown in fig. 1 by a dash-dot line.

During operation of the motor-chiller circuit 14, the coolant flows through the chiller 8, the motor circuit pump 6, the electric drive 2, the chiller valve 3a and back to the chiller 8 again in that order. As described above, the motor-chiller circuit 14 may operate simultaneously with the HVS-chiller circuit 13. The motor-chiller circuit may also be operated with the HVS-chiller circuit 13 shut off, wherein the HVS-chiller circuit 13 is shut off at this time in such a way that the HVS valve 10 prevents flow through the HVS lines and the HVS pump 9 is turned off. When the motor-chiller circuit 14 operates together with the HVS-chiller circuit 13, both the waste heat of the accumulator 11 and the waste heat of the electric drive 2 can be fed into the chiller 8 and can be introduced into a heating circuit 15, explained later, via the refrigeration circuit 30.

If the motor-chiller circuit 14 is operational and the HVS-chiller circuit 13 is either off or not operational, then preferably the refrigeration circuit 30 is also off so that the chiller 8 is substantially not operational. Waste heat of the electric drive 2 is thus fed into the energy storage device 11, so that the energy storage device 11 can be heated by means of this waste heat. This is of interest, for example, in cold ambient temperatures.

Downstream of the motor circuit pump 6 or between the motor circuit pump 6 and the electric drive 2, the heating circuit 15 branches off from the motor cooling circuit 1 at a heating circuit branching point 25. Between the freezer circuit branch point 3 and the cooler 4, the heating circuit 15 again leads into the motor cooling circuit 1.

The heating circuit 15 has a shut-off valve 16, a water-cooled condenser 17, a heating circuit pump 18, an electric heater 19 and an interior heat exchanger 20. These components are usually flowed through in the described sequence during operation of the heating circuit 15. The interior heat exchanger 20 is arranged in an air-guiding device 21, such as an air flow duct, which is shown and by means of which air is guided into a passenger compartment of the motor vehicle, not shown, so that the passenger compartment can be heated by means of the interior heat exchanger 20. The flow through the heating line 15 can be allowed or prevented by means of the shut-off valve 16, wherein an intermediate position of the shut-off valve 16 is also possible.

To form a heating circuit 22 (shown in dashed lines), a heating return line 23 is provided, which connects the downstream outlet of the interior heat exchanger 20 and the upstream inlet of the condenser 17 in a fluid-conducting manner to one another. A non-return valve 24 is arranged in the heating return line 23, which non-return valve permits a flow only in the direction from the outlet of the interior heat exchanger 20 towards the inlet of the condenser 17. The passenger compartment can be heated by means of the heating circuit 22 in that the coolant circulated by means of the heating circuit pump 18 is heated at least by the electric heater 19 and the thermal energy is output to the interior heat exchanger 20. In other operating states, the coolant is additionally or alternatively heated by the condenser 17, for example by waste heat from the electrical energy accumulator 11(HVS) and/or the electric drive 2, depending on which heat from these components is available. The waste heat of electric drive 2 is the waste heat generated by the operation of electric drive 2. This waste heat can be increased in a targeted manner if necessary by adjusting the at least one electric motor of the electric drive 2. If only the heating circuit 22 is to be operated, no coolant flows from the motor cooling circuit 1 into the heating circuit 15 and no coolant flows from the heating circuit 15 into the motor cooling circuit 1, the shut-off valve 16 prevents a flow through.

Figure 2 schematically illustrates a refrigeration circuit 30 of a thermal management system according to one embodiment of the invention. The refrigeration circuit 30 comprises a water-cooled condenser 17, a freezer 8 and an air conditioning evaporator 31 arranged in the air guiding device 21. A refrigerant, such as R134a, R1234yf, R1234ze or the like, circulates through these components. The refrigerator 8 is a heat exchanger or heat carrier that transfers thermal energy between the refrigerant of the refrigeration circuit 30 and the coolant in the refrigerator line 7. For this purpose, the refrigerant and the coolant flow through the freezer 8 in a fluid-separated manner. The air conditioning evaporator 31 is a heat exchanger or heat carrier which transfers thermal energy between the refrigerant of the refrigeration circuit 30 and the air flowing in the air guiding device 21. For this purpose, the refrigerant and air flow through the air conditioning evaporator 31 in a fluid-separated manner from one another. The air conditioning evaporator 31 is connected in parallel with the refrigerator 8 in the refrigeration circuit 30. In order to adjust the cooling capacity of the air conditioning evaporator 31, a self-regulating, electrically switchable expansion valve 32 is connected upstream of the air conditioning evaporator. An expansion valve 33 is connected upstream of the refrigerator 8. Both the interior space heat exchanger 20 and the air conditioning evaporator 31 are disposed within the air guiding device 21. By means of which the passenger compartment can be heated, cooled and/or dehumidified.

The refrigeration circuit 30 also has an electric compressor 34, by means of which the refrigerant can be compressed and conveyed. The refrigeration circuit 30 in fig. 2 also has two internal heat exchangers 35, 36, one of which is assigned to the air conditioning evaporator 31 and the other to the freezer 8. The internal heat exchangers 35, 36 each have two chambers which are in thermal contact with one another but can be flowed through in a fluidically separated manner. Here, one chamber is connected upstream of the freezer or air conditioner evaporator and the other chamber is connected downstream of the freezer/air conditioner evaporator. The chambers are traversed in opposite directions and thus constitute a counterflow heat exchanger. The refrigerant from the compressor, which is predominantly in the liquid state, therefore flows through the internal heat exchanger in one chamber, while the refrigerant from the freezer or air-conditioning evaporator, which is predominantly in the gaseous state, flows through the internal heat exchanger in the other chamber. By means of the internal heat exchangers 35, 36, heat energy is extracted from the predominantly liquid refrigerant, which results in a higher proportion of liquefaction. This energy is supplied to the refrigerant, which is predominantly in the gaseous state, which results in a higher proportion of the evaporation and is present in gaseous form. This serves to increase the power and efficiency of the freezer 8 and the air conditioning evaporator 31. The internal heat exchangers 35, 36 are not necessarily essential for the function of the refrigeration circuit 30. A check valve 37 or a check valve is provided downstream of the air conditioning evaporator 31.

Downstream of the condenser 17, the refrigeration circuit 30 branches into parallel lines, one of which leads to the air-conditioning evaporator 31 and the other to the freezer 8. From this point on, the internal heat exchanger 35, the expansion valve 32, the air-conditioning evaporator 31, the internal heat exchanger 35, the check valve 37 and the compressor 34 are flown through in this order in one line. The internal heat exchanger 36, the expansion valve 33, the refrigerator 8, the internal heat exchanger 36, and the compressor 34 are passed through another line in this order. The parallel lines merge again upstream of the compressor 34.

Some modes of operation of the thermal management system are described below.

In the case of cooling in which the cooler 4 is intended to output the heat of the electric drive 2 to the environment, the motor cooling circuit 1 is operated such that the waste heat of the electric drive 2 is output via the cooler 4 to the ambient air.

The HVS-chiller circuit 13 has been described above. Additionally or alternatively, the motor-chiller circuit 14 may be in operation. The waste heat of the electric drive 2 is fed to the refrigerator 8 via a motor-refrigerator circuit 14. This thermal energy is input to the condenser 17 via the freezer 8 and the refrigeration circuit 30 as described above. This thermal energy can then be fed from the condenser 17 into the heating circuit 22 and/or the heating circuit 15 (so-called heat pump function). Here, depending on the waste heat and heating requirements of the individual components, only the HVS-chiller circuit 13, only the motor-chiller circuit 14, or both may be operated.

Furthermore, an AC circuit 26 may be formed, which is shown in fig. 1 by a dash-dot line. In this AC circuit 26, the heating line 15, the cooler 4 and the motor circuit pump 6 (in particular in this order) are flowed through in succession. Downstream of the motor circuit pump 6, the AC circuit 26 leads back again into the heating circuit 15. To operate the AC circuit 26, the shut-off valve 16 is opened and the heating circuit pump 18 and/or the motor circuit pump 6 are operated. If the AC circuit 26 is to be operated without the electric drive 2 being traversed, the freezer valve 3a prevents the traversing of the electric drive 2. This operating mode serves to discharge the waste heat generated at the condenser 17 into the ambient air via the cooler 4 during the cooling or air conditioning of the vehicle interior.

In addition to this, the HVS-chiller circuit 13 can also be operated, i.e. both are activated simultaneously. In this case, the energy storage 11 is additionally cooled and the waste heat generated in this case at the condenser 17 is dissipated via the cooler 4 into the ambient air.

In addition to this, the motor cooling circuit 1 can also be operated in such a way that the chiller valve 3a allows a flow through the electric drive 2. In this case, the electric drive 2 is additionally cooled and the waste heat generated in this case is dissipated via a cooler 4 into the ambient air.

These modes of operation are not exhaustive and those skilled in the art will certainly be able to advantageously use other modes of operation based on the illustrated functionality and the layout of the thermal management system.

Figure 3 schematically shows a heating and cooling circuit of a thermal management system according to a second embodiment of the invention. The thermal management system may be provided in a vehicle in place of the thermal management system of the first embodiment. This thermal management system differs from the thermal management system of the first embodiment in that: in the heating circuit 15, the NT cooler 40 is provided upstream of the shutoff valve 16, i.e., between a branch point of the heating circuit 15 from the motor cooling circuit 1 and the shutoff valve 16. The NT cooler 40 is arranged in front of the cooler 4 as seen in the vehicle longitudinal direction, wherein, in connection with this second embodiment, the cooler 4 assumes the function of an HT cooler. In addition to the described differences, reference is made entirely to the description of the first embodiment.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character and not intended to limit the invention to the disclosed embodiments. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

List of reference numerals

1 Motor Cooling Circuit

2 electric drive

3 refrigerator line branch point

3a refrigerator valve

4 cooler

5 compensating container

6 motor loop pump

7 refrigerating machine circuit

8 refrigerator

9 HVS pump

10 HVS valve

11 electric energy accumulator

12 one-way valve

13 HVS-refrigerator circuit

14 motor-refrigerator circuit

15 heating circuit

16 stop valve

17 water-cooled condenser

18 heating loop pump

19 electric heater

20 internal space heat exchanger

21 air guiding device

22 heating circuit

23 heating return line

24 one-way valve

25 branch point of heating circuit

26 AC circuit

30 refrigeration circuit

31 air conditioner evaporator

32 expansion valve

33 expansion valve

34 electric compressor

35 internal heat exchanger

36 internal heat exchanger

37 check valve

40 NT cooler

Claims

1. A thermal management system for a motor vehicle, the thermal management system comprising:

-a motor cooling circuit (1) in which an electric drive (2), a freezer circuit branch point (3), a cooler (4) and a motor circuit pump (6) are arranged;

-a refrigerator line (7) with a refrigerator (8), which branches off from the motor cooling circuit (1) at a refrigerator line branching point (3) and opens into the motor cooling circuit (1) at a point between the cooler (4) and the motor circuit pump (6); and

-a heating line (15) with an interior space heat exchanger (20), which branches off from the motor cooling circuit (1) at a point between the motor circuit pump (6) and the electric drive (2) and opens into the motor cooling circuit (1) at a point between the freezer circuit branch point (3) and the cooler (4).

2. The thermal management system according to claim 1, comprising a motor-chiller circuit (14) in which the electric drive (2), the chiller (8) and the motor-chiller pump (6) are arranged, the motor-chiller circuit (14) leading from the chiller (8) to the motor-circuit pump (6) bypassing the cooler (4).

3. The thermal management system of any of the preceding claims, comprising an AC circuit (26) with a heating circuit (15), a cooler (4) and a motor circuit pump (6).

4. Thermal management system according to any of the preceding claims, comprising an HVS-chiller circuit (13) with a chiller (8) and an electrical energy accumulator (11).

5. The thermal management system of any of the preceding claims, comprising a heating circuit (22) with an interior space heat exchanger (20) and an electric heater (19).

6. Thermal management system according to one of the preceding claims, comprising a refrigeration circuit (30) with a freezer (8), an air-conditioning evaporator (31) and a water-cooled condenser (17), the freezer (8) being able to be traversed by refrigerant of the refrigeration circuit (30) and being able to be traversed by coolant of the motor-cooling circuit (1) and/or of the motor-freezer circuit (14) in a manner that is fluidically separated from refrigerant of the refrigeration circuit, and the air-conditioning evaporator (31) being provided in an air guiding device (21), by means of which air can be guided into the vehicle passenger compartment.

7. The thermal management system according to any of the preceding claims, wherein the electric drive (2) has at least one electric motor for driving a motor vehicle.

8. The thermal management system according to claim 7, wherein the electric drive (2) further has an inverter, a direct current converter, a battery control device and/or a vehicle interior charger.

9. Automotive vehicle comprising a thermal management system according to any of the preceding claims.