DE102022112574B3 - Method for starting a thermal management system for electric vehicles and thermal management system therefor - Google Patents

Abstract

Today's electric vehicles have a short range at low outside temperatures, since a significant proportion of the electrical energy is used for heating the vehicle cabin. Heat pumps are now being used to reduce the use of electrical energy for heating the vehicle cabin. The disadvantage here is that known heat pump arrangements (1) with today's common refrigerants such as R134a or R1234yf, at very low temperatures, -20 ° C and lower, can not fully cover the heat requirement for the vehicle cabin heating. A thermal management system for electric vehicles is specified which, even at very low temperatures, can heat the vehicle cabin sufficiently without an electric cabin heater. Heat from the coolant heater (220) and the compressor (10) is used for the cabin heating. By providing a non-optional second start-up procedure--divided into an optional first and a non-optional second start-up phase--the system is started up safely. In the optional first start-up phase, the compressor oil in the external heat exchanger (40) is fed back into the refrigerant circuit so that it is again available for lubricating the compressor (10). In the non-optional second start-up phase, refrigerant condensed in the external heat exchanger (40) is fed back into the active refrigerant circuit.

Description

The invention relates to a method for starting a thermal management system according to claim 1 and a thermal management system for carrying out this method according to claim 10.

Today's electric vehicles have a short range at low outside temperatures, since a significant proportion of the electrical energy is used for heating the vehicle cabin. Heat pumps are now being used to reduce the use of electrical energy for heating the vehicle cabin.

The applicant offers such thermal management systems for electric vehicles with a heat pump arrangement 1 that 7 have the structure shown. The heat pump arrangement 1 connects a compressor 10 with a compressor inlet 11 and a compressor outlet 12 via a refrigerant circuit, a cabin condenser 20 for heating the air in a vehicle cabin with a condenser inlet 21 and a condenser outlet 22, an external heat exchanger 40 for absorbing heat from or dissipating heat to the environment with an outdoor heat exchanger inlet 41 and an outdoor heat exchanger outlet 42, a chiller 80 or external evaporator with a chiller inlet 81 and a chiller outlet 82, the chiller inlet 81 being connected to a chiller expansion valve 70, a cabin evaporator 60 having a cabin evaporator inlet 61 and a cabin evaporator outlet 62, wherein a cabin evaporator expansion valve 50 is connected upstream of the cabin evaporator inlet 61 . On the air side, the cabin condenser 20 is provided with an air mixing flap 2 for temperature regulation. Optionally, an internal heat exchanger may be placed to transfer heat between the refrigerant before entering the cabin evaporator expansion valve 50 and the refrigerant after the cabin evaporator outlet 62 . A bypass line 100 is provided between the outdoor heat exchanger outlet 42 and the compressor inlet 11 and can be shut off via a bypass shut-off valve 90 . This refrigerant bypass line 100 is needed in heating or heat pump mode.

In order to be able to heat the vehicle cabin sufficiently even at very low temperatures, an electric cabin heater 300 is provided for the vehicle cabin. The thermal management system also includes a battery 210 and an electric coolant heater 220. The electric coolant heater 220 is integrated into a coolant circuit 200 between the chiller 80 and the battery 210. Evaporation heat is supplied to the chiller 80 via the coolant circuit 200 .

A valve unit 110 is arranged between the outdoor heat exchanger outlet 42 and the chiller expansion valve 70 on the one hand and the outdoor heat exchanger inlet 41 and the condenser outlet 22 on the other hand. The valve unit 110 comprises a first and a second refrigerant inlet 111, 113, and a first and a second refrigerant outlet 112, 114. Optionally, a high-pressure-side refrigerant reservoir can be provided in the valve unit 110. Depending on the operating mode, the valve unit 110 blocks, directs or throttles the refrigerant flows between the refrigerant inlets 111, 113 and the refrigerant outlets 112, 114. Using a controller 400, the heat pump arrangement 1 or the thermal management system can be operated in various operating modes, such as start or heating mode.

In a heat pump or heating mode, refrigerant condensed by the cabin condenser 20 is supplied to the valve unit 110 via the first refrigerant inlet 111 . Liquid refrigerant is then supplied to the chiller expansion valve 70 via the second refrigerant outlet 114 and the chiller expansion valve 70 creates a controlled expansion. The expanded coolant is vaporized in the chiller 80 by heat input via the coolant circuit 200 and compressed in the compressor 10 . The compressed refrigerant gas from the compressor 10 is condensed in the cabin condenser, giving off heat to the air which is supplied to the vehicle cabin.

A disadvantage of the heat pump arrangement after 7 with today's common refrigerants, such as R134a or R1234yf, is that at very low temperatures, -20°C and lower, they cannot fully cover the heat requirement for the vehicle cabin heating. This is due to the low suction pressure of the compressor 10 at very low temperatures. If the suction pressure falls, the density of the refrigerant and thus the refrigerant mass flow decrease for a given maximum volumetric flow rate of the compressor 10. The refrigerant mass flow and consequently the heat flow, which is supplied to the vehicle cabin via the cabin condenser 20, decrease as a result.

There are a number of ways to increase heating, such as: B. gas injection systems, hot gas bypass heating systems or electric cabin heaters 300 - see 7 . The aforementioned measures entail additional costs and additional installation space, which is not always available. The electric heaters 300 and 220 reduce the range of an electric vehicle. Various solutions are known from the prior art, for example from WO 2021 171 802 A1 , the WO 2021 015 483 A1 and the WO 2021 024 755 A1 .

It is therefore the object of the present invention to heat the vehicle cabin sufficiently without an electric cabin heater, even at very low temperatures in the range of around -20°C.

This object is achieved by a method according to claim 1 or by a device according to claim 10.

Heat from the coolant heater and the compressor is used for the cabin heating. By providing a start-up procedure--divided into an optional first and a second start-up phase according to claim 1--the system is started up safely. In addition, damage to the compressor by liquid refrigerant from the outdoor heat exchanger and/or the chiller is prevented.

In the first start-up phase, compressor oil separated in the external heat exchanger is fed back into the active part of the refrigerant circuit for a first period of time Δt1, so that the compressor is adequately lubricated. The valve unit is switched to a first operating mode and connects the condenser outlet of the cabin condenser to the first refrigerant outlet of the valve unit and the outdoor heat exchanger outlet to the second refrigerant outlet of the valve unit. At very low outside temperatures, the gaseous refrigerant from the compressor condenses in the cabin condenser and liquefied refrigerant is fed to the outside heat exchanger. The compressor oil is flushed out of the external heat exchanger with the liquid refrigerant and fed to the compressor.

The first start-up phase should be carried out at ambient temperatures ≤ -20°C. In the first start-up phase, the compressor is operated in a lower speed range - approx. 1/4 to 1/3 of the maximum speed. At ambient temperatures > - 20°C, the first start-up phase can be omitted, ie Δt ₁ =0, and the start-up procedure begins with the second start-up phase - claim 2.

In the second start-up phase, liquid refrigerant is vaporized in the external heat exchanger for a second period of time Δt ₂ and brought back into the refrigerant circuit through which it flows. This takes place in that the bypass shut-off valve in the bypass line is opened and the valve unit blocks the first refrigerant outlet and at the same time connects the refrigerant-side condenser outlet of the cabin condenser to the second refrigerant outlet. At the same time, the valve unit closes the connection between the outdoor heat exchanger outlet and the second refrigerant outlet 114. The blocked first refrigerant outlet of the valve unit reduces the pressure in the outdoor heat exchanger and liquid refrigerant in the outdoor heat exchanger evaporates.

According to the advantageous embodiment according to claim 3, in the second start-up phase, the compressor continues to be operated in the lower speed range during a first partial time period Δt ₂₁ for safety reasons.

According to claim 4, the speed of the compressor is increased for a second partial time period Δt ₂₂ to a medium speed range (about 1/2 of the maximum speed), since then hardly any more liquid refrigerant is sucked out of the external heat exchanger.

The second start-up phase preferably ends when the pressure in the external heat exchanger has dropped to the suction pressure at the compressor inlet 11 . This should be the case after 60 to 180 seconds - Claim 5.

In an advantageous implementation, the bypass shut-off valve is partially opened for a third partial time period Δt ₂₃ and then fully opened for a fourth partial time period Δt ₂₄ of the duration of the second start-up phase. The partial opening prevents the compressor from being charged with too large a quantity of liquid refrigerant - claim 6.

The heating phase follows - claim 7 - in which at least heat from the electric coolant heater and waste heat from the compressor are used to heat the vehicle cabin. To switch to the heating phase, the bypass shut-off valve in the bypass line is closed. In this case, the valve unit continues to be operated according to the second start-up phase.

In the heating phase, heat from the external heat exchanger can preferably also be used to heat the cabin. For this purpose, the bypass shut-off valve is opened and the refrigerant mass flow is adjusted through the variable opening cross-section at the first refrigerant outlet of the valve unit in such a way that a desired overheating of the refrigerant results after the external heat exchanger - claim 8.

Depending on the heating capacity requirement of the cabin, the compressor may also be operated at an upper speed range during the heating phase - Claim 9.

According to claim 10, a thermal management system is provided which enables operation with the first and/or second start-up phase and in the heating phase.

According to an advantageous embodiment, a refrigerant collector is provided on the high-pressure side as part of the valve unit--claim 11--or on the low-pressure side upstream of the compressor--claim 12. Depending on requirements, more or less refrigerant is actively available in the refrigerant circuit through the refrigerant collector, or refrigerant is buffered for the different operating modes of the heat pump arrangement. There is also a separation between liquid and gaseous refrigerant in the refrigerant collector. Finally, refrigerant losses are compensated for by small leaks as the life of the heat pump assembly progresses.

• 1 zeigt den Aufbau der Wärmepumpenanordnung, die wesentlicher Teil eines Thermomanagementsystems für Fahrzeuge ist;
• 2 zeigt die zeitliche Abfolge der verschiedenen Phasen;
• 3 zeigt das Thermomanagementsystem in einer ersten Anlaufphase - Rückführung von Verdichteröl in den Wärmepumpenkreislauf;
• 4 zeigt das Thermomanagementsystem in einer zweiten Anlaufphase - Rückführung von Kältemittel in den Wärmepumpenkreislauf;
• 5 zeigt das Thermomanagementsystem in der Heizphase;
• 6 zeigt eine zweite Ausführungsform der Erfindung mit einem niederdruckseitigen Kältemittelsammler; und
• 7 zeigt den Aufbau eines Thermomanagementsystems nach dem Stand der Technik.

Further details, features and advantages of the invention result from the following description of a preferred embodiment of the invention.

• 1 shows the structure of the heat pump arrangement, which is an essential part of a thermal management system for vehicles;
• 2 shows the chronological sequence of the various phases;
• 3 shows the thermal management system in a first start-up phase - recirculation of compressor oil in the heat pump circuit;
• 4 shows the thermal management system in a second start-up phase - recirculation of refrigerant in the heat pump circuit;
• 5 shows the thermal management system in the heating phase;
• 6 shows a second embodiment of the invention with a low-pressure-side refrigerant collector; and
• 7 shows the structure of a thermal management system according to the prior art.

1 shows the structure of a heat pump arrangement 1, which is an essential part of a thermal management system for vehicles. The thermal management system 1 differs from the thermal management system according to 7 only due to the absence of the electrical cabin heating and due to the special design of the control 400, which enables operation in the first and/or second start-up phase and in the heating phase. In the first start-up phase, liquid compressor oil is fed back from the external heat exchanger 40 into the heat pump circuit. In the second start-up phase, liquid refrigerant in the outdoor heat exchanger 40 is returned to the compressor inlet via the bypass line 100 by evaporation. In the heating phase, low-grade heat from the coolant circuit 200 is coupled into the chiller 80 and this heat is released together with waste heat from the compressor 10 at a higher pressure and temperature level as heat of condensation in the cabin condenser 20 for heating the vehicle cabin.

2 shows the timing of the two start-up phases and the heating phase together with the heating output of the electric coolant heater 220, the speed of the compressor 10, the state of the bypass shut-off valve 90 in the bypass line 100, the switching state of the valve unit 110, the refrigerant pressure in the external heat exchanger 40 with the Suction pressure at compressor inlet 11.

In the first start-up phase - 3 - The electric coolant heater 220 and the compressor 10 is switched on. The compressor 10 is operated at a lower speed range (about 1/4 to 1/3 of the maximum speed). The low speed prevents any liquid refrigerant fed into the compressor from causing damage. Low-grade heat from the electric coolant heater 220 is coupled into the chiller 80 via the coolant circuit 200 through the refrigeration cycle. The bypass check valve 90 in the bypass line 100 is closed. The valve unit 110 is in a switching state I. In the switching state I, the connection between the first refrigerant inlet 111 and the first refrigerant outlet 112 and between the second refrigerant inlet 113 and the second refrigerant outlet 114 is released. In addition, the connection between the first refrigerant inlet 111 and the first refrigerant outlet 112 is free. At the low outside temperatures, for example -20° C., the gaseous refrigerant from the compressor 10 condenses completely in the cabin condenser 20 and in the outside heat exchanger 40 . The liquid refrigerant from the cabin condenser 20 and the external heat exchanger 40 flushes the compressor oil into the chiller 80. The refrigerant in the chiller 80 evaporates and the compressor oil is fed to the compressor 10 due to the heat from the electric coolant heater 220 coupled into the chiller 80 via the coolant circuit 200 , which lubricates it. The active parts of the refrigerant circuit are in 3 drawn in bold. The first start-up phase should be carried out at ambient temperatures ≤ -20°C. The lower the ambient temperature, the longer the first start-up phase takes. At ambient temperatures > -20°C, the first start-up phase can be omitted, ie Δt ₁ =0, and the start-up procedure begins with the second start-up phase.

In the second start-up phase - 4 - Liquid refrigerant is vaporized in the external heat exchanger 40 for a second period of time Δt ₂ and shifted back into the part of the refrigerant circuit through which it flows. The transition from the first start-up phase to the second start-up phase takes place in that the bypass shut-off valve 90 in the bypass line 100 is partially opened and the valve unit 110 is switched to switching state II. In switching state II, the first refrigerant outlet 112 is blocked, the connection between the second refrigerant inlet 113 and the second refrigerant outlet 114 is closed and the connection between the first refrigerant inlet 111 and the second refrigerant outlet 114 is released. If the first start-up phase is dispensed with, the bypass shut-off valve 90 is opened so that the outdoor heat exchanger outlet 42 is connected to the compressor inlet 11 . The first refrigerant outlet 112 is blocked. The connection between the first refrigerant inlet 111 and the second refrigerant outlet 114 is released by the valve unit 110 - switching state II of the valve unit 110.

As a result, the refrigerant pressure in the outdoor heat exchanger 40 drops and liquid refrigerant in the outdoor heat exchanger 40 is evaporated. This is carried out for a first partial time period Δt ₂₁ until the pressure in the outdoor heat exchanger 40 has dropped to the suction pressure at the compressor inlet 11 . Thereafter, for a second partial period of time Δt ₂₂ , the speed of the compressor 10 is increased to a medium speed range—approximately 1/2 of the maximum speed—and the suction pressure and the pressure in the external heat exchanger 40 continue to drop, so that liquid refrigerant in the external heat exchanger 40 continues to evaporate . After .DELTA.t ₂ = .DELTA.t ₂₁ + .DELTA.t ₂₂ = 60 to 180 seconds ends the second start-up phase. Alternatively, the second start-up phase ends when superheated refrigerant is present at the compressor inlet 11 .

In an advantageous implementation, the bypass shut-off valve 90 is partially opened for a third partial time period Δt ₂₃ and then fully opened for a fourth partial time period Δt ₂₄ of the duration of the second start-up phase. The partial opening prevents the compressor from being charged with too much liquid refrigerant. The first and third partial periods of time on the one hand and the second and fourth partial periods of time can be the same.

The active parts of the refrigerant circuit are in 4 drawn in bold. The refrigerant discharge from the outside heat exchanger 40 is shown in dotted lines.

The heating phase follows - 5 , in which at least heat from the electric coolant heater 220 and waste heat from the compressor 10 are used to heat the vehicle cabin. To switch from the second start-up phase to the heating phase, the controller 400 causes the bypass shut-off valve 90 in the bypass line 100 to be closed and the valve unit 110 to remain in switching state II.

At higher ambient temperatures, additional thermal energy can be absorbed from the environment via the external heat exchanger 40 . To do this, the bypass shut-off valve 90 must be open and the valve unit 110 regulates the overheating of the refrigerant downstream of the external heat exchanger 40 via the degree of opening of the first refrigerant outlet 112.

The compressor 10 is operated in an upper speed range up to the maximum speed. The controller 400 regulates the thermal management system such that the condensation temperature in the cabin condenser 20 enables a desired temperature in the vehicle cabin. This is done using the speed of the compressor 10 as a manipulated variable. The refrigerant gas in the chiller 80 is overheated by the degree of opening of the chiller expansion valve 70 as a manipulated variable.

Optionally, a refrigerant collector 4 can be provided upstream of the compressor 10 on the high-pressure side as part of the valve unit 110 or on the low-pressure side. Depending on requirements, the refrigerant collector 4 makes more or less refrigerant actively available in the refrigerant circuit or refrigerant is buffered for the different operating modes of the heat pump arrangement 1 . A separation between liquid and gaseous refrigerant also takes place in the refrigerant collector 4 . Finally, coolant losses due to small leaks are also compensated for as the service life of the heat pump arrangement 1 is advanced.

In the high-pressure-side arrangement of the refrigerant collector 4 with a refrigerant collector inlet 5 and a refrigerant collector outlet 6 as part of the valve unit 110 - not shown - the refrigerant collector inlet 5 is connected via the first refrigerant inlet 111 to the refrigerant-side condenser outlet 22 or via the second refrigerant inlet 113 to the external heat exchanger outlet 42 and the Refrigerant header outlet is connected to the second refrigerant outlet 114 . This arrangement is in the DE 102022104545.5 , filed on 02/25/2022. With regard to the arrangement of the refrigerant collector is on the DE 102022104545.5 fully referred to.

In the low-pressure side arrangement of the refrigerant collector 4 before the compressor 10 according to 6 is the refrigerant collector outlet 6 with the compressor inlet 11 and the refrigerant receiver inlet 5 is connected to the chiller outlet 82 and the bypass check valve 90 . The 6 differs from the 1 only through the refrigerant collector 4 in front of the compressor 10.

Reference List

1

heat pump arrangement

2

air mix door

4

refrigerant collector

5

refrigerant collector inlet

6

refrigerant collector outlet

10

compressor

11

compressor inlet

12

compressor outlet

20

cabin condenser

21

refrigerant side condenser inlet

22

refrigerant side condenser outlet

40

outdoor heat exchanger

41

refrigerant-side outdoor heat exchanger inlet

42

refrigerant-side outdoor heat exchanger outlet

50

Cabin evaporator expansion valve

60

cabin evaporator

61

refrigerant side cabin evaporator inlet

62

refrigerant-side cabin evaporator outlet

70

Chiller expansion valve

80

chillers

81

refrigerant side chiller inlet

82

refrigerant side chiller outlet

90

Bypass shut-off valve

100

Bypass line for refrigerant between outdoor heat exchanger and compressor

110

valve unit

111

first refrigerant inlet of 110

112

first refrigerant outlet of 110

113

second refrigerant inlet from 110

114

second refrigerant outlet from 110

200

coolant circuit

210

battery

220

Electric coolant heater

300

Electric cabin heater

400

steering

Δt1

first duration, duration of the first start-up phase

Δt2

second duration, duration of the second start-up phase

Δt21

first partial duration of Δt ₂

Δt22

second partial duration of Δt ₂

Δt23

third partial duration of Δt ₂

Δt24

fourth partial duration of Δt ₂

Claims (12)

Method for starting a thermal management system for electric vehicles, in particular at low ambient temperatures, the thermal management system comprising a battery (210), an electric coolant heater (220), a heat pump arrangement (1) and a controller (400), the heat pump arrangement (1) having a compressor (10) with compressor inlet (11) and compressor outlet (12), a cabin condenser (20) with a refrigerant-side condenser inlet (21) and a refrigerant-side condenser outlet (22), an external heat exchanger (40) with refrigerant-side external heat exchanger inlet (41) and refrigerant-side external heat exchanger outlet (42 ), a chiller expansion valve (70) and a chiller (80) with a refrigerant-side chiller inlet (81) and a refrigerant-side chiller outlet (82), a valve unit (110) and a bypass line (100) with a bypass check valve (90) between the outdoor heat exchanger outlet (42) and the compressor inlet (11), wherein the valve unit (110) is connected to the condenser outlet (22) via a first refrigerant inlet (111), is connected to the outdoor heat exchanger inlet (41) via a first refrigerant outlet (112), via a second refrigerant inlet (113) is connected to the outdoor heat exchanger outlet (42), and a second refrigerant outlet (114) is connected to the chiller expansion valve (70), and wherein the electric coolant heater (220) is connected to a coolant circuit (200) between the Battery (210) and the chiller (80) is involved, with the method steps: s0) activating the electric coolant heater (220); s1) operating the heat pump arrangement (1) in an optional first start-up phase s2) and in a non-optional second start-up phase s3), with s2) operating the heat pump arrangement (1) for a first period of time (Δt ₁ ) in a first start-up phase, during which heat from the coolant circuit (200) evaporates refrigerant at a lower pressure level in the chiller (80), which was compressed in the compressor (10). Refrigerant condenses at an upper pressure level in the cabin condenser (20) with heat dissipation to air to be supplied to a vehicle cabin, and the liquid refrigerant is supplied via the valve unit (110), the outdoor heat exchanger (40) and again to the chiller expansion valve (70); s3) reducing the pressure in the outdoor heat exchanger (40) for a second period of time (Δt ₂ ) in a second start-up phase by opening the bypass shut-off valve (90) in the bypass line (100) and simultaneously closing the first refrigerant outlet (112) and by releasing the Connection between the first refrigerant inlet (111) and the second refrigerant outlet (114) by means of the valve unit (110). procedure after claim 1 , characterized in that the first start-up phase is dispensed with at ambient temperatures > -20°C, d. _hΔt1 =0. procedure after claim 1 or 2 , characterized in that the compressor (10) in step s2) and during a first partial time period (Δt ₂₁ ) in step s3) is operated in a lower speed range. Method according to one of the preceding claims, characterized in that the compressor (10) is operated in a medium speed range during a second partial time period (Δt ₂₂ ) in step s3). Method according to one of the preceding claims, characterized in that the second period of time (Δt ₂ ) is determined by the fact that the pressure in the external heat exchanger (40) has equalized the suction pressure of the compressor (10). Method according to one of the preceding claims, characterized in that the bypass shut-off valve (90) is partially opened for a third partial time period (Δt ₂₃ ) and then fully opened for a fourth partial time period (Δt ₂₄ ). Method according to one of the preceding claims, characterized in that after the end of the first and / or second start-up phase, there is a transition to a heating phase in which heat from the coolant circuit (200) evaporates refrigerant at a lower pressure level in the chiller (80), which in Compressor (10) compresses refrigerant at an upper pressure level in the cabin condenser (20) while releasing heat to a vehicle cabin, and the liquid refrigerant is fed back to the chiller expansion valve (70) via the valve unit (110). procedure after claim 7 , characterized in that in the heating phase the bypass shut-off valve (90) is also opened and the refrigerant mass flow from the first refrigerant outlet (112) is adjusted by the valve unit (110) in such a way that a desired overheating of the refrigerant occurs after the external heat exchanger (40 ) results at the refrigerant-side external heat exchanger outlet (42), whereby ambient heat is coupled into the cabin condenser (20) via the external heat exchanger (40) and the compressor (10). procedure after claim 7 or 8th , characterized in that the compressor (10) is operated in the heating phase at an upper speed range. Thermal management system for electric vehicles for carrying out the method according to one of the preceding claims, having: a battery (210), an electric coolant heater (220), a heat pump arrangement (1) and a controller (400), the heat pump arrangement (1) having a compressor (10 ) with refrigerant-side compressor inlet (11) and refrigerant-side compressor outlet (12), a cabin condenser (20) with refrigerant-side condenser inlet (21) and refrigerant-side condenser outlet (22), an external heat exchanger (40) with refrigerant-side external heat exchanger inlet (41) and refrigerant-side external heat exchanger outlet (42), a chiller expansion valve (70) and a chiller (80) with a refrigerant-side chiller inlet (81) and a refrigerant-side chiller outlet (82), a valve unit (110), and a bypass line (100) with a bypass check valve (90) between the outdoor heat exchanger outlet ( 42) and the compressor inlet (11), the valve unit (110) comprising a first refrigerant inlet (111) which is connected to the condenser outlet (22), a first refrigerant outlet (112) which is connected to the outdoor heat exchanger inlet (41), a second refrigerant inlet (113) connected to the outdoor heat exchanger outlet (42) and a second refrigerant outlet (114) connected to the chiller expansion valve (70), wherein the electric coolant heater (220) is integrated into a coolant circuit (200) between the battery (210) and the chiller (80), and wherein the controller (400) is designed to control the thermal management system in the optional first and the non-optional second to operate in the start-up phase and in the heating phase. thermal management system claim 10 , characterized in that the valve unit (110) on the high-pressure side comprises a refrigerant collector (4) with a refrigerant collector inlet (5) and a refrigerant collector outlet (6), that the valve unit (110) connects the refrigerant collector inlet (5) via the first refrigerant inlet (111) to the refrigerant-side condenser outlet (22) or via the second refrigerant inlet (113) to the outdoor heat exchanger outlet (42), and that the valve unit (110) connects the refrigerant collector outlet (6) to the second refrigerant outlet (114). thermal management system claim 10 , characterized in that the heat pump system (1) comprises a refrigerant collector (4) on the low-pressure side, which comprises a refrigerant collector inlet (5) and a refrigerant collector outlet (6), that the refrigerant collector outlet (6) is connected to the compressor inlet (11), and that the Refrigerant receiver inlet (5) is connected to the chiller outlet (82) and the bypass check valve (90).

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