DE102020207305A1 - Heat pump system for a vehicle - Google Patents

Abstract

A heat pump system (100) for a vehicle is proposed, the heat pump system (100) comprising a coolant circuit (10). The coolant circuit (10) includes a battery coolant circuit (20) connected to a battery (21) and allowing coolant to flow therein. Furthermore, the heat pump system (100) comprises a refrigerant circuit (80), which comprises a first heat exchanger (81) for dissipating heat from the refrigerant to the air of an interior of the vehicle, and a cooling unit (60), which is designed to transfer heat from the coolant to the transfer refrigerant. The coolant circuit (10) and the refrigerant circuit (80) are connected via the cooling unit (60) in such a way that heat can be removed from the battery coolant circuit (20) in order to transfer it to the air in the interior of the vehicle by means of the first heat exchanger (81). transfer.

Description

The present invention relates to a heat pump system for a vehicle and a method for operating a heat pump system according to the independent claims.

Heat pump systems are known from the prior art, which implement a strong prioritization of the thermal comfort of the customer. This is achieved above all by installing several high-voltage heaters as heating units, in particular for directly heating the refrigerant, which gives off heat to the air in an air conditioning system. This is associated with high costs.

The object of the present invention is to improve a heat pump system in such a way that an optimum of performance, function and costs is achieved.

The aforementioned object is achieved by a heat pump system for a vehicle that includes a coolant circuit. The coolant circuit is used to circulate a coolant, in particular cooling water. The coolant circuit in turn includes a battery coolant circuit that is connected to a battery and allows coolant to flow therein. In other words, the battery coolant circuit is a sub-circuit of the coolant circuit, which is used to either heat or cool the battery. The battery is in particular the battery of the vehicle, the vehicle being in particular an electric vehicle.

The heat pump system also includes a refrigerant circuit. The refrigerant is in particular R744. The refrigerant circuit is used to circulate the refrigerant. The refrigerant circuit comprises a first heat exchanger for releasing heat from the refrigerant to air in an interior of the vehicle. The vehicle interior is in particular the cabin. The heat pump system, in particular the refrigerant circuit, is in particular part of an air conditioning system of the vehicle, which ensures the air in the interior is circulated, the refrigerant circuit serving to heat or cool the air. Furthermore, the heat pump system has a cooling unit which is designed to transfer heat from the coolant to the coolant. The cooling unit is in particular a so-called chiller.

The coolant circuit and the refrigerant circuit are connected via the cooling unit in such a way that heat can be removed from the battery coolant circuit in order to transfer it to the air in the interior of the vehicle by means of the first heat exchanger. In other words, the heat for heating the air in the interior can be taken from the battery coolant circuit of the coolant circuit. The battery coolant circuit can thus be used as a heat source for the refrigerant.

The refrigerant circuit advantageously does not have a heating unit for heating the refrigerant. The term heating unit is to be understood in particular as an electrically driven heating unit that is used exclusively for heating the refrigerant. In particular, this is to be understood as a high-voltage heater. A heating unit for heating the refrigerant on the side of the refrigerant circuit is used in the prior art to heat the refrigerant directly, namely to reheat the air flow that flows into the vehicle interior when the heat pump system is insufficiently heated. The heat pump system also preferably does not have an air-side, in particular electrical, heating unit for heating the air in the interior of the vehicle.

Such an expensive heating unit, which is arranged on the air side or on the side of the refrigerant circuit, can be dispensed with on the basis of the present invention, since heat can be drawn from the battery coolant circuit. The waiver of the heating unit is only associated with minimal functional restrictions of the heat pump system. The present invention thus enables a compromise which enables significant cost savings with minor restrictions in thermal comfort.

The refrigerant circuit has, among other things, a compressor which serves to compress the refrigerant and thus to increase the pressure and the temperature of the refrigerant. The compressor is not to be understood as a heating unit in the above-mentioned sense, since the compressor is not used exclusively for heating the refrigerant, but the heating of the refrigerant is an automatic consequence of the compression. Furthermore, the refrigerant circuit preferably has a second heat exchanger, which is used to enable the refrigerant to absorb heat from the outside air of the vehicle. The second heat exchanger can be a cryogenic cooler.

In particular, the above-mentioned components are arranged in such a way that, after being compressed in the compressor, the refrigerant first passes through the first heat exchanger, then an evaporator, then part of the refrigerant passes through the cooling unit and another part passes through the second heat exchanger until the refrigerant passes again flows into the compressor.

The coolant circuit primarily has a waste heat circuit for extracting waste heat from an engine and / or power electronics of the vehicle, which is connected to the engine and / or the power electronics and thus enables the coolant to absorb waste heat from them. The waste heat circuit is in particular a sub-circuit of the coolant circuit. The waste heat circuit has, in particular, a first heat exchanger which is designed so that the coolant can absorb heat from the outside air of the vehicle. Furthermore, the waste heat circuit can have an electric pump. Furthermore, the first heat exchanger of the coolant circuit can be arranged in such a way that, in addition to the second heat exchanger of the refrigerant circuit, heat can also be absorbed from the outside air and transferred to the refrigerant via it.

Furthermore, the coolant circuit can have a third switching valve in order to either allow coolant to circulate independently of the battery coolant circuit or to allow it to flow into the battery coolant circuit. The battery coolant circuit can also have a second switching valve in order to allow the coolant to circulate separately from the waste heat circuit or to allow it to flow into the waste heat circuit. The battery coolant circuit can also include an electric pump.

The battery coolant circuit has a heating unit and a first switching valve, namely a switching valve, which is arranged between the heating unit and the cooling unit in such a way that the cooling unit can be connected either to the waste heat circuit or to the battery coolant circuit. Both the waste heat from the electric motor and / or power electronics and the battery coolant circuit can thus be used as a heat source in order to heat the refrigerant via the cooling unit. The heating unit is in particular a high-voltage heater that heats the coolant in the battery coolant circuit. This is particularly useful when there is insufficient availability of heat from the outside air or from the electric motor and / or power electronics. Direct heating of the coolant in the battery coolant circuit can thus ensure that the coolant is sufficiently warm to sufficiently heat the air in the interior of the vehicle. It is also advantageous here that an expensive heating unit on the side of the refrigerant circuit can be omitted and instead only a few inexpensive components have to be integrated on the side of the coolant circuit. Because a switching valve is used as the first switching valve, the waste heat utilization is retained, since the cooling unit can be integrated into the waste heat circuit as well as into the battery coolant circuit.

Furthermore, the battery coolant circuit can have a heating unit, in which case, however, no first switching valve is provided, but rather the heating unit is arranged in such a way that the coolant of the battery coolant circuit always flows through it. Furthermore, the third switching valve is arranged in the battery coolant circuit in such a way that waste heat can be used by the electric motor and the power electronics and the coolant can be heated by the heating unit. The second switching valve can be a switchover valve or a proportional valve.

If the switching valve is a switching valve, the use of waste heat and the additional heating of the coolant are not possible in combination, but only cyclically. If, on the other hand, it is a proportional valve, a parallel use of both options is guaranteed.

The first heat exchanger for releasing heat from the refrigerant to the air can be designed as a refrigerant-air heat exchanger, in particular a gas cooler, for directly transferring the heat from the refrigerant to the air. Furthermore, the first heat exchanger can comprise an additional water circuit, namely with a water-air heat exchanger and a water-refrigerant heat exchanger. The additional water circuit is used to transfer the heat from the refrigerant to the air via the water in the additional water circuit.

A heating mat can preferably be provided for direct heating of the battery.

Furthermore, the battery coolant circuit can have a non-return valve so that the coolant circuit in the battery coolant circuit runs in the opposite direction to the direction of the waste heat circuit. No heating unit can be provided in the battery coolant circuit, since the battery is heated via the heating mat.

In addition, a heating unit can also be provided so that the coolant can be heated even more effectively and thus a corresponding discharge to the coolant can take place by means of the cooling unit. The waste heat can be used simultaneously with the use of the battery coolant circuit as a heat source. Furthermore, the battery coolant circuit can be designed in such a way that the cooling unit and the heating unit are arranged in a separate circuit. This circuit can include its own electric pump.

Advantageously, the battery can also have a battery refrigerant circuit of the Refrigerant circuit are cooled. The battery refrigerant circuit is in particular a sub-circuit of the refrigerant circuit. There is thus direct battery cooling via the refrigerant. In particular, the battery refrigerant circuit comprises an expansion valve.

Figure list

• 1: ein erfindungsgemäßes Wärmepumpensystem;
• 2: ein weiteres erfindungsgemäßes Wärmepumpensystem;
• 3: ein weiteres erfindungsgemäßes Wärmepumpensystem;
• 4: ein weiteres erfindungsgemäßes Wärmepumpensystem;
• 5: ein weiteres erfindungsgemäßes Wärmepumpensystem;
• 6: ein weiteres erfindungsgemäßes Wärmepumpensystem;
• 7: ein weiteres erfindungsgemäßes Wärmepumpensystem; und
• 8: ein weiteres erfindungsgemäßes Wärmepumpensystem.

It shows in a purely schematic view:

• 1 : a heat pump system according to the invention;
• 2 : Another heat pump system according to the invention;
• 3 : Another heat pump system according to the invention;
• 4th : Another heat pump system according to the invention;
• 5 : Another heat pump system according to the invention;
• 6th : Another heat pump system according to the invention;
• 7th : Another heat pump system according to the invention; and
• 8th : Another heat pump system according to the invention.

Preferred embodiments of the invention

1 shows a heat pump system according to the invention 100 .

The heating case is shown, so that the air in the cabin of the vehicle is to be heated. On the right is a refrigerant circuit 80 to see. The refrigerant circuit 80 includes a compressor 83 , in which refrigerant is compressed, increasing its pressure and temperature. The compressed refrigerant flows through the ASV valve 62 in the first heat exchanger 81 , which gives off the heat to the air in the vehicle interior, in other words to the air of the air conditioning system. With the first heat exchanger 81 it is a refrigerant-air heat exchanger that directly transfers the heat from the refrigerant to the air in a cabin of the vehicle, in other words the air conditioning system. The refrigerant circuit can have a collector 85 with an integrated heat exchanger.

The refrigerant then flows through an expansion valve 61 into the vaporizer 84 and then part of the refrigerant through an expansion valve 61 in the cooling unit 60 and part through an expansion valve 61 to the second heat exchanger 82 . Both parts of the refrigerant that pass through the second heat exchanger 82 or the cooling unit 60 flow are then returned to the compressor 83 fed. The refrigerant can thus both in the second heat exchanger 82 as well as in the cooling unit 60 Absorb heat. In the cooling unit 60 it takes heat from the coolant circuit 10 on, which is shown on the left, while it is in the second heat exchanger 82 Absorbs heat from the outside air. The cooling unit 60 is the link between the coolant circuit 10 and the refrigerant circuit 80 and is used to transfer heat from the coolant to the refrigerant.

The coolant circuit 10 on the left of the 1 includes a battery coolant circuit 20th and a waste heat cycle 40 . In the waste heat cycle 40 is an engine 41 and power electronics 42 as well as a first heat exchanger 43 of the waste heat cycle 40 involved. It can thus waste heat from the engine 41 and / or power electronics 42 be transferred to the coolant and thus used, the first heat exchanger 43 serves to absorb heat from the outside air. The first heat exchanger 43 can be arranged so that the refrigerant in the refrigerant circuit can absorb heat via this.

Furthermore, the waste heat cycle 40 an electric pump 63 have and a thermostat 44 . Using the thermostat 44 can be set, depending on the temperature, whether the coolant is the first heat exchanger 43 runs through or circulates. Furthermore, the waste heat cycle 40 a third switching valve 66 so that the coolant is either independent of the battery coolant circuit 20th can run or flow into them.

The battery coolant circuit 20th instructs the battery 21 as well as a heating unit 22nd which is used to heat the coolant directly. Furthermore, the battery coolant circuit 20th a first switching valve 64 so that the coolant passes to the cooling unit 60 can be supplied to give off its heat there, or in the battery coolant circuit 20th remains to continue using the heating unit 22nd to be heated. Furthermore, the battery coolant circuit 20th a second switching valve 65 on. As clearly in 1 As can be seen, the refrigerant is not heated by means of a heating unit, but the heat can be passed through the first switching valve 64 via the cooling unit 60 both from the battery coolant circuit 20th as well as from the waste heat cycle 40 can be removed.

2 shows a further heat pump system according to the invention 100 , which is analogous to the 1 is trained. The heat pump system does not have a first switching valve 64 on, but the cooling unit 60 is direct into the battery coolant circuit 20th integrated so that the coolant in the circuit always flows through it. In other words are the heating unit 22nd and the cooling unit 60 arranged in the same strand. By means of the second switching valve 65 , which is designed as a switchover valve, a change between the battery coolant circuit 20th and waste heat cycle 40 respectively. Thus, an operation between waste heat utilization from the waste heat cycle 40 and heating the battery 21 respectively.

In 3 is another heat pump system according to the invention 100 shown, which is analogous to the one in 2 shown heat pump system 100 is trained. The second switching valve 65 is designed here as a proportional valve so that waste heat can be used from the waste heat cycle 40 as a benefit of the battery coolant circuit 20th can take place as a heat source at the same time.

4th shows a further heat pump system according to the invention 100 , which is analogous to the one in 2 or 3 shown heat pump system 100 is trained. The first heat exchanger 81 is not designed here as a refrigerant-air heat exchanger, but the refrigerant circuit 80 includes an additional water circuit 87 with a water-to-air heat exchanger 88 and a water-refrigerant heat exchanger 89 so that the heat of the refrigerant passes through the water of the additional water circuit 87 is transmitted to the air.

5 shows another heat pump system 100 , which is analogous to the one in 1 shown heat pump system 100 is trained. It's not a first switching valve 64 and no heating unit 22nd present. The cooling unit 60 is directly in the battery coolant circuit 20th involved. Furthermore, the battery coolant circuit 20th a check valve 24 so that the coolant circulates counterclockwise, while it circulates clockwise in the waste heat circuit 40. The battery 21 is by means of a heating mat 23 directly heated.

6th shows another heat pump system 100 , which is analogous to the one in 5 shown heat pump system 100 is trained. Additionally is in the battery coolant circuit 20th a heating unit 22nd , between the cooling unit 60 and check valve 24 , installed so that the coolant can also be heated.

7th represents another heat pump system according to the invention 100 where the cooling unit 60 and the heating unit 22nd are arranged in a separate circuit, the one electric pump 63 includes. In other words, further lines are provided, each in front of the heating unit 22nd and after the cooling unit 60 that form a separate line in which the electric pump 63 is built in. Thus, by means of the strand, the cooling unit 60 and the heating unit 22nd be bypassed.

In 8th is another heat pump system according to the invention 100 which, apart from the following differences, is analogous to the one in 5 shown heat pump system 100 is trained. In addition to the heating mat 23 can the battery 22nd by means of its own battery refrigerant circuit 90 be cooled via a direct battery cooling unit 91 . The battery refrigerant circuit 90 sets in the connection line between the cooling unit 60 and the first heat exchanger 81 and the connection line between the cooling unit 60 and the vaporizer 84 on. In the battery refrigerant circuit 90 can also include an expansion valve 61 be arranged.

List of reference symbols

100

Heat pump system

10

Coolant circuit

20th

Battery coolant circuit

21

battery

22nd

Heating unit

23

Heating mat

24

Check valve

40

Waste heat cycle

41

engine

42

Power electronics

43

first heat exchanger

44

thermostat

60

Cooling unit

61

Expansion valves

62

ASV valve

63

electric pump

64

first switching valve

65

second switching valve

66

third switching valve

80

Refrigerant circulation

81

first heat exchanger

82

second heat exchanger

83

compressor

84

Evaporator

85

Collector

87

additional water circuit

88

Water-to-air heat exchanger

89

Water-refrigerant heat exchanger

90

Battery refrigerant circuit

91

direct battery cooling unit

Claims (12)

A heat pump system (100) for a vehicle, the heat pump system (100) comprising: - a coolant circuit (10) comprising a battery coolant circuit (20) which is connected to a battery (21) and enables a coolant to flow therein, a refrigerant circuit (80), the refrigerant circuit (80) comprising a first heat exchanger (81) for releasing heat from the refrigerant to the air in an interior of the vehicle, - a cooling unit (60) which is designed to supply heat from the coolant to the refrigerant transferred, characterized in that the coolant circuit (10) and the refrigerant circuit (80) are connected via the cooling unit (60) in such a way that heat can be removed from the battery coolant circuit (20) in order to transfer it to the To transmit air of the interior of the vehicle. Heat pump system (100) Claim 1 , characterized in that the refrigerant circuit (80) does not have a heating unit for heating the refrigerant. Heat pump system (100) according to one of the Claims 1 or 2 , characterized in that the heat pump system (100) does not have an air-side heating unit for heating the air in the interior of the vehicle. Heat pump system (100) according to one of the preceding claims, characterized in that the coolant circuit (10) has a waste heat circuit (40) for removing waste heat from an engine (41) and / or power electronics (42) of the vehicle, which is connected to the engine ( 41) and / or the power electronics (42) and enables the coolant to absorb waste heat from them. Heat pump system (100) according to one of the preceding claims, characterized in that the battery coolant circuit (20) has a heating unit (22) and a first switching valve (64), namely a switching valve, the switching valve in such a way between the heating unit (22) and the cooling unit (60) is arranged so that the cooling unit (60) can optionally be connected to the waste heat circuit (40) or to the battery coolant circuit (20). Heat pump system (100) according to one of the Claims 1 until 4th , characterized in that the battery coolant circuit (20) has a heating unit (22), the heating unit (22) being arranged in such a way that the heating unit (22) is always flowed through by the coolant of the battery coolant circuit (20), a second switching valve ( 65) is arranged in the battery coolant circuit (20) in such a way that waste heat from the motor (41) and / or the power electronics (42) and the heating of the coolant by the heating unit (22) is possible, and the second switching valve ( 65) is a changeover valve or a proportional valve. Heat pump system (100) according to one of the preceding claims, characterized in that the first heat exchanger (81) for emitting heat from the refrigerant to the air is designed as a refrigerant-air heat exchanger for directly transferring the heat from the refrigerant to the air first heat exchanger (81) has an additional water circuit (87) with a water-air heat exchanger (88) and a water-refrigerant heat exchanger (89) for transferring the heat of the refrigerant to the air via water of the additional heating circuit (87). Heat pump system (100) according to one of the preceding Claims 1 , 2 , 3 , 4th or 7th , characterized in that a heating mat (22) is provided for direct heating of the battery (21). Heat pump system (100) Claim 8 , characterized in that the battery coolant circuit (20) has no heating unit (22) for heating the coolant. Heat pump system (100) Claim 8 , characterized in that the battery coolant circuit (20) has a heating unit (22) for heating the coolant. Heat pump system (100) according to one of the Claims 8 until 10 , characterized in that the battery (21) is further cooled via a battery refrigerant circuit (90) of the refrigerant circuit. Method for operating a heat pump system for a vehicle according to one of the Claims 1 until 11th .

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