DE102019132688A1 - Thermal management system for a motor vehicle and method for thermal management of a motor vehicle - Google Patents

Abstract

The invention relates to a heat management system for a motor vehicle, with a motor chiller circuit (36) in which a chiller (29), an electrical energy store (25) and an electric motor (2, 3) are arranged; an HVS chiller circuit (6) in which the chiller (29) and the electrical energy store (25) are arranged bypassing the electric motor (2, 3); a cooling circuit (40) via which thermal energy can be transported from the chiller (29) to a condenser (15), and a heating circuit (13) through which coolant can flow and in which the condenser (15) and an interior heat exchanger (18) are arranged , An operating state is provided in which both the motor chiller circuit (36) and the HVS chiller circuit (6) are in operation. In addition, the invention relates to a method for thermal management of a motor vehicle.

Description

The invention relates to a heat management system for a motor vehicle and a method for heat management of a motor vehicle.

Thermal management systems for electrified motor vehicles are known which provide heating power for a vehicle interior by means of a heat pump functionality in which existing heat sources, e.g. Electric motor and high voltage storage can be used.

Especially at cold temperatures, the coolant is relatively viscous and the pump is put under a lot of stress in this operating state. This operating point may not correspond to an optimal volume flow for which the pump was designed. With radial pumps, the impeller can only be optimized for one flow rate. Due to an inefficient pump operating point, hydraulic component requirements can only be met with appropriate dimensioning.

It is therefore an object of the present invention to at least partially solve the aforementioned problems. This object is achieved by a heat management system according to claim 1 and a method according to claim 5. Advantageous developments of the invention are the subject of the dependent claims.

According to one exemplary embodiment of the invention, a heat management system for a motor vehicle is provided, with an engine chiller circuit in which a chiller, an electrical energy store and at least one electric motor are arranged, and an HVS chiller circuit in which the chiller and the electrical energy store are arranged bypassing the electric motor, an operating state being provided in which both the motor-chiller circuit and the HVS-chiller circuit are in operation. The highest possible volume flow is advantageous for uniform distribution of the heating energy to all cells in the energy store. Through a targeted bypass to the electric motor, the electric motor can continue to be flowed through and thus the waste heat of the electric motor can be introduced into the energy store and at the same time a high volume flow can be achieved. Relief of the HVS pump can thus be achieved without heat loss, so that a more efficient pump operating point is generated. The increased efficiency leads to a higher volume flow and a better flow through the energy store.

According to a further exemplary embodiment of the invention, a bypass line is provided which forms a section of the HVS chiller circuit and represents a bypass to the electric motor.

According to a further exemplary embodiment of the invention, the heat management system is designed with a branching of the HVS chiller circuit and the motor chiller circuit, at which a coolant flow can be divided into a proportion of coolant that flows through the electric motor and a proportion of coolant, which flows through the bypass line.

According to a further exemplary embodiment of the invention, the heat management system is designed with HVS switchover means with which a division of coolant at a branching of the HVS chiller circuit and the motor-chiller circuit into a proportion of coolant that flows through the electric motor, and a proportion of coolant that flows through the bypass line is adjustable.

According to a further exemplary embodiment of the invention, the heat management system is further equipped with a refrigeration circuit via which thermal energy can be transported from the chiller to a condenser, and a heating line through which coolant can flow and in which the condenser and an interior heat exchanger are arranged.

In addition, the invention provides a method for heat management of a motor vehicle, comprising the steps of: circulating coolant in an engine chiller circuit through a chiller, an electrical energy store and an electric motor, and circulating coolant in an HVS chiller circuit the chiller and the electrical energy store bypassing the electric motor, an operating state being provided in which the motor-chiller circuit and the HVS-chiller circuit are in operation at the same time. This method provides the same advantages as already described above in connection with the thermal management system.

According to a further exemplary embodiment of the invention, the method is further embodied with the step: setting HVS switching means with which it is possible to switch between the engine chiller circuit and the HVS chiller circuit in such a way that the engine chiller circuit Circulation and the HVS chiller circuit are flowed through.

According to a further exemplary embodiment of the invention, the method is further embodied with the step of dividing the coolant flow at the HVS switchover means into an engine component, which flows through the electric motor and a bypass component which flows past the electric motor, the motor component being more than 50% of the coolant flow at an input of the HVS switching means.

According to a further exemplary embodiment of the invention, the method is also designed such that, in the dividing step, the bypass fraction is less than 30%, in particular less than 20%, of the coolant flow at an input of the HVS switching means.

• 1 zeigt schematisch Heiz- und Kühlkreisläufe eines Wärmemanagementsystems gemäß einem Ausführungsbeispiel der Erfindung, und
• 2 zeigt schematisch einen Kältekreislauf des Wärmemanagementsystems gemäß einem Ausführungsbeispiel der Erfindung.

Preferred embodiments of the present invention are described below with reference to the accompanying drawings. The following is shown in these drawings:

• 1 shows schematically heating and cooling circuits of a heat management system according to an embodiment of the invention, and
• 2nd shows schematically a refrigeration cycle of the heat management system according to an embodiment of the invention.

1 shows schematically heating and cooling circuits of a heat management system according to an embodiment of the invention. The heat management system is preferably installed in a motor vehicle, not shown, in particular a passenger car, for example an electric vehicle. The heating and cooling circuits of the thermal management system include an engine cooling circuit 1 , in the electric motors 2nd and 3rd as well as power electronics components 4th and 5 are arranged. The electric motors 2nd and 3rd are traction motors for driving the motor vehicle, although of course only one or more than two such electric motors can be provided. The power electronics components 4th and 5 include, for example, the electric motors 2nd , 3rd assigned inverters, a DC converter, a battery controller and an on-board charger. The electric motor is more precise 2nd and the power electronics component 4th in the engine cooling circuit 1 connected in series as well as the electric motor 3rd and the power electronics component 5 in the engine cooling circuit 1 connected in series. These two series connections are in turn in the engine cooling circuit 1 parallel to each other. The power electronics components can also be used 4th and or 5 parallel to the electric motors 2nd , 3rd be arranged. Downstream of this parallel connection are a chiller valve 7 , an HT cooler 11 as well as a cooler pump 12 arranged. In the engine cooling circuit 1 is with the chiller valve open accordingly 7 and activated cooler pump 12 a coolant can be circulated, for example a water mixed with additives.

Parallel to the electric motors 2nd , 3rd as well as the power electronics components 4th , 5 is a heating element 13 intended. More precisely branches between the radiator pump 12 and that in the engine cooling circuit 1 components to be cooled (ie the electric motors 2nd , 3rd and the power electronics components 4th , 5 ) the heating element 13 from the engine cooling circuit 1 from. Between the chiller valve 7 and the HT cooler 11 the heating element opens 13 back into the engine cooling circuit 1 .

The heating element 13 has an NT cooler 14 , a heating element valve 8th , a water-cooled condenser 15 , a heating circuit pump 16 , an electric heater 17th as well as an indoor heat exchanger 18th on. These components are in operation of the heating train 13 usually flows in this order. The heating element valve 8th is, for example, a shut-off valve and upstream of the condenser 15 arranged.

The indoor heat exchanger 18th is within an indicated air duct 19th , for example an air flow channel, is arranged, with which air is led into a passenger compartment of the motor vehicle, not shown, so that by means of the interior heat exchanger 18th the passenger compartment can be heated. By means of the heating element valve 8th there may be a flow through the heating line 13 are allowed or prevented, including intermediate positions of the heating element valve 8th possible are.

The NT cooler 14 and the HT cooler 11 are arranged so that ambient air can flow through them so that they can be cooled by the wind. In particular, the two coolers 11 , 14 Arranged one behind the other seen in the vehicle longitudinal direction, the NT cooler 14 in front of the HT cooler 11 is arranged. The two coolers 11 , 14 is a blower 20th assigned to promote an air flow through this in addition to the airstream. In a known manner, the two coolers 11 , 14 an expansion tank 21st assigned.

For forming an EDH heating circuit 22 (shown with a dashed line) is a heating return line 23 provided a downstream outlet of the indoor heat exchanger 18th with an upstream input of the capacitor 15 fluidly interconnects. In the heating return line 23 is a one-way valve 24th provided which is only a flow in one direction from the exit of the indoor heat exchanger 18th towards the input of the capacitor 15 allows. Using the EDH heating circuit 22 the passenger compartment can be heated by using the heating circuit pump 16 circulated coolant at least from the electric heater 17th is heated and this thermal energy to the indoor heat exchanger 18th is delivered. In other operating states, the coolant is additionally or alternatively used by the condenser 15 heated, for example by waste heat from an electrical energy store 25th (HVS), the electric motors 2nd , 3rd and / or the power electronics components 4th , 5 , depending on the amount of heat available from these components. To increase the waste heat from the electric motors 2nd , 3rd these can be trimmed, ie they are brought into an operating state in which more waste heat is produced.

In addition, the thermal management system has a HVS line 9 on the one HVS pump 10th , an HVS valve 26 , the electrical energy storage 25th (HVS), a check valve 27 and HVS switching means 32 which has a branch 28 are positioned. The elements mentioned are in the operation of the HVS rod 9 flows in particular in the order mentioned. The HVS switching device 32 are in 1 as a changeover valve or a 2/3-way valve, but these can also be formed by two or three shut-off valves.

There is also a chiller line in the heat management system 30th provided the chiller 29 as well as the chiller valve 7 having. The chiller valve 7 is in 1 designed as a changeover valve or a 2/3-way valve, but this can also be formed by two or three shut-off valves.

The chiller is on the side facing away from the chiller valve 29 with an input side of the HVS pump 10th connected, a connecting line leads from this connecting section 31 which is a one-way valve 33 or has a check valve to the engine cooling circuit 1 at a point between the confluence of the heating line 13 in the engine cooling circuit 1 and the chiller valve 7 .

Between the chiller 29 and the chiller valve 7 branches a bypass line 34 starting to branching 28 or the HVS switching means 32 leads. Another connection of the branch 28 or the HVS switching means 32 is with a connecting line 35 connected to the engine cooling circuit 1 opens out at a point upstream of the parallel connection of electric motors 2nd , 3rd and power electronics components 4th , 5 and downstream of the cooler pump 12 .

2nd shows schematically a refrigeration cycle 40 of the heat management system according to an embodiment of the invention. The refrigeration cycle 40 includes the water-cooled condenser 15 , the chiller 29 as well as a climate evaporator 41 which is in the air duct 19th is arranged. It should be noted that it does not necessarily have to be a water-cooled condenser, but that the invention can also be used advantageously in connection with an air-cooled condenser. A refrigerant, for example, circulates through these components R134a , R1234yf , R1234ze or similar. The chiller 29 is a heat exchanger or heat exchanger, the thermal energy between the refrigerant of the refrigeration cycle 40 and the coolant in the chiller line 26 transmits. For this purpose, the refrigerant and the coolant flow through the chiller in a fluid-separate manner 29 . The climate evaporator 41 is a heat exchanger or heat exchanger, the thermal energy between the refrigerant of the refrigeration cycle 40 and one in the air duct 19th flowing air. For this purpose, the refrigerant and the air flow through the air conditioning evaporator in a fluid-separate manner 41 . The climate evaporator 41 is in the refrigeration cycle 40 parallel to the chiller 29 switched. For setting the cooling capacity of the air conditioning evaporator 41 is a self-regulating and electrically lockable expansion valve 42 upstream. The chiller 29 is an expansion valve 43 upstream. The indoor heat exchanger 18th and the climate evaporator 41 are both in the air flow 19th arranged. They can be used to heat, cool and / or dehumidify the passenger compartment.

Furthermore, the refrigeration cycle 40 an electric compressor 44 with which the refrigerant can be compressed and pumped. The refrigeration cycle 40 in 2nd also has two internal heat exchangers 45 , 46 on, one of which is the climate evaporator 41 and the other the chiller 29 assigned. The internal heat exchangers 45 , 46 each have two chambers that can be flowed through in thermal contact, but fluidly separated from each other. One chamber is connected upstream of the chiller or air conditioning evaporator and the other chamber is connected downstream of the chiller / air conditioning evaporator. The chambers are flowed through in the opposite direction and thus form a counterflow heat exchanger. The internal heat exchanger thus flows through the predominantly liquid refrigerant coming from the compressor in one chamber and the predominantly gaseous refrigerant coming from the chiller or air conditioning evaporator in the other chamber. Through the inner heat exchanger 45 , 46 thermal energy is extracted from the predominantly liquid refrigerant, which means that an even higher proportion is liquefied. This energy is added to the predominantly gaseous refrigerant, which means that an even higher proportion evaporates and is gaseous. This serves to increase the performance and efficiency of the chiller 29 and the climate evaporator 41 . For the function of the refrigeration cycle 40 are the internal heat exchangers 45 , 46 but not absolutely necessary. Downstream of the air conditioning evaporator 41 is a check valve 47 or one-way valve arranged.

Downstream of the capacitor 15 the refrigeration cycle branches 40 into the parallel strands, one of which is to the air conditioning evaporator 41 and the other to the chiller 29 leads. From this point, the inner heat exchanger will be in one strand in this order 45 , the expansion valve 42 , the climate evaporator 41 , the inner heat exchanger 45 , the check valve 47 and the compressor 44 flows through. In the other line, the inner heat exchanger is in this order 46 , the expansion valve 43 , the chiller 29 , the inner heat exchanger 46 and the compressor 44 flows through. The parallel strands become upstream of the compressor 44 merged again.

Some operating modes of this thermal management system are described below.

In cooling cases where the HT cooler 11 The engine cooling circuit is used to dissipate heat to the environment 1 operated so that waste heat from the electric motors 2nd , 3rd and / or the power electronics components 4th , 5 about the HT cooler 11 is released into the ambient air.

With the in 1 circuit shown can be a HVS chiller circuit 6 (along the dashed line). The HVS pump is activated 10th Coolant from the energy storage 25th along the bypass line 34 to the chiller 29 guided. After flowing through the chiller 29 promotes the HVS pump 10th the coolant back to the energy storage 25th etc. In this way, for example, waste heat from the energy storage 25th in the chiller 29 are entered and from there via the cooling circuit 40 over the capacitor 15 in the heating line 13 or the EDH heating circuit 22 be entered. This is the energy storage 25th cooled while the waste heat can be used for heating purposes.

In addition, an engine-chiller circuit can be used 36 (along the dash-dot line). The HVS pump is activated 10th Coolant from the energy storage 25th , about the electric motors 2nd , 3rd as well as the power electronics components 4th , 5 to the chiller 29 promoted. The HVS pump delivers from there 10th the coolant back to the energy storage 25th etc. In this operating state, the electric motor 2nd , 3rd be trimmed so that it generates more waste heat. By operating the motor-chiller circuit 36 is a waste heat from the electric motor 2nd , 3rd in the energy storage 25th entered to heat the energy storage in cold ambient conditions. The chillers are in this operating state 29 and the refrigeration cycle 40 preferably switched off. Depending on the environmental and operating conditions, the chiller 29 and the refrigeration cycle 40 but also be in operation.

With the HVS switching devices 32 can one of the electrical energy storage 25th incoming coolant into the connecting line 35 are directed, this coolant portion being referred to as the engine portion. Furthermore, with the HVS switching means 32 that of electrical energy storage 25th coolant flow coming into the connecting line 36 are directed, this coolant portion being referred to as the bypass portion because of this on the electric motors 2nd , 3rd is led past.

With the HVS switching devices 32 can the whole of the electrical energy storage 25th incoming coolant flow, ie that at an input of the HVS switching means 32 present coolant flow, in the bypass line 34 be guided while flowing through the connecting line 35 is blocked. This is the HVS chiller cycle 6 trained during the motor-chiller cycle 36 is not active.

Furthermore, with the HVS switching means 32 the whole of the electrical energy storage 25th incoming coolant flow, ie that at an input of the HVS switching means 32 present coolant flow, in the connecting line 35 be guided while flowing through the bypass line 34 is blocked. This is the engine-chiller cycle 36 trained during the HVS chiller cycle 6 is not active.

According to the invention with the HVS switching means 32 an intermediate position can be realized, so that at the same time a flow through the bypass line 34 as well as the connecting line 35 he follows. This is the HVS chiller cycle at the same time 6 as well as the motor-chiller circuit 36 in operation. This is from the electrical energy storage 25th incoming coolant flow, ie that at an input of the HVS switching means 32 present coolant flow, divided into the engine portion and the bypass portion. In particular, the engine portion is greater than the bypass portion, ie the engine portion is more than 50% of the coolant flow upstream of the branch 28 . In particular, the bypass fraction is less than 30% of the coolant flow upstream of the branch 28 . In particular, the bypass fraction is less than 15% of the coolant flow upstream of the branch 28 . With simultaneous operation of the HVS chiller circuit and the motor chiller circuit 36 is the chiller 29 and the refrigeration cycle 40 preferably switched off, depending on the ambient and operating conditions the chiller can 29 and the refrigeration cycle 40 but also be switched on.

An embodiment is also conceivable in which the HVS switching means 32 is dispensed with and the cooling circuit is designed in such a way, for example by line cross sections, that the above-mentioned division without the HVS switching means 32 is realized permanently.

The HVS chiller cycle 6 and / or the motor-chiller circuit 36 can simultaneously with the engine cooling circuit described above 1 operate.

These operating modes are not conclusive and the person skilled in the art is certainly able to use other operating modes advantageously on the basis of the functionality shown and the circuit diagram of the heat management system.

While the invention has been illustrated and described in detail in the drawings and the foregoing description, this description is intended to be exemplary rather than restrictive, and is not intended to limit the invention to the disclosed embodiment. The mere fact that certain features are mentioned in various dependent claims is not intended to imply that a combination of these features could not be used to advantage.

Reference symbol list

1

Engine cooling circuit

2nd

Electric motor

3rd

Electric motor

4th

Power electronics component

5

Power electronics component

6

HVS chiller circuit

7

Chiller valve

8th

Heater valve

9

HVS line

10th

HVS pump

11

HT cooler

12

Radiator pump

13

Heating element

14

NT cooler

15

Water cooled condenser

16

Heating circuit pump

17th

Electric heater

18th

Indoor heat exchanger

19th

Airflow

20th

fan

21st

surge tank

22

EDH heating circuit

23

Heating return line

24th

One-way valve

25th

Electrical energy storage

26

HVS valve

27th

check valve

28

branch

29

Chiller

30th

Chiller strand

31

Connecting line

32

HVS switching device

33

One-way valve

34

Bypass line

35

Connecting line

36

Motor-chiller circuit

40

Refrigeration cycle

41

Air conditioning evaporator

42

Expansion valve

43

Expansion valve

44

Electric compressor

45

Internal heat exchanger

46

Internal heat exchanger

47

check valve

Claims (9)

Thermal management system for a motor vehicle, with a motor-chiller circuit (36) in which a chiller (29), an electrical energy store (25) and an electric motor (2, 3) are arranged, and an HVS chiller circuit (6) in which the chiller (29) and the electrical energy store (25) are arranged bypassing the electric motor (2, 3); an operating state is provided in which both the motor-chiller circuit (36) and the HVS-chiller circuit (6) are in operation. Thermal management system according to Claim 1 A bypass line (34) is provided, which forms a section of the HVS chiller circuit (6) and represents a bypass to the electric motor (2, 3). Thermal management system according to Claim 2 , with a branching (28) of the HVS chiller circuit (6) and the motor chiller circuit (36) at which a coolant flow can be divided into a proportion of coolant flowing through the electric motor (2, 3), and a portion of coolant flowing through the bypass line (34). Thermal management system according to Claim 2 or 3rd , with HVS switching means (32), with which a division of coolant at a branch (28) of the HVS chiller circuit (6) and the motor-chiller circuit (36) into a proportion of coolant, which by the electric motor (2, 3) flows, and a proportion of coolant which flows through the bypass line (34) is adjustable. Thermal management system according to one of the preceding claims, further comprising a refrigeration cycle (40) via which thermal energy can be transported from the chiller (29) to a condenser (15), and a heating section (13) through which coolant can flow and in which the condenser (15) and an interior heat exchanger (18) are arranged. Method for thermal management of a motor vehicle, comprising the steps: Circulating coolant in a motor-chiller circuit (36) through a chiller (29), an electrical energy store (25) and an electric motor (2, 3), and Circulating coolant in an HVS chiller circuit (6) through the chiller (29) and the electrical energy store (25) bypassing the electric motor (2, 3), an operating state is provided in which the motor-chiller circuit (36) and the HVS-chiller circuit (6) are in operation at the same time. Procedure according to Claim 6 , with the step: setting HVS switching means (32) with which it is possible to switch between the motor chiller circuit (36) and the HVS chiller circuit (6) in such a way that the motor chiller circuit simultaneously (36) and the HVS chiller circuit (6) are flowed through. Procedure according to Claim 7 , with the step of dividing the coolant flow at the HVS switchover means (32) into a motor part which flows through the electric motor (2, 3) and a bypass part which flows past the electric motor (2, 3), the Motor share is more than 50% of the coolant flow at an input of the HVS switching means (32). Procedure according to Claim 8 , wherein in the dividing step the bypass fraction is less than 30% of the coolant flow at an input of the HVS switching means (32).

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