Thermal system for an electric or hybrid vehicle, electric or hybrid vehicle, method for operating a thermal system

Abstract

A thermal system for a vehicle having a comprehensive cooling circuit, a refrigeration circuit, a cooling circuit, a heating circuit, and a plurality of switched states is disclosed. The cooling circuit is connected with a heat source of the vehicle. The cooling circuit has a high-voltage accumulator (HVA) circuit to which a high-voltage accumulator for supplying power to an electric drivetrain of the vehicle is connected. An ambient cooler is connected to the cooling circuit downstream of the heat source. A chiller for transferring heat from the HVA circuit into the refrigeration circuit is also connected to the refrigeration circuit. A first switched state, in which the HVA circuit downstream and upstream of the heat source is connected to the cooling circuit, can be set such that an extended HVA circuit, in which the high-voltage accumulator and the heat source are connected in series is configured.

Claims

1. A thermal system having a plurality of switched states for a vehicle comprising: a heat source for heating a high-voltage accumulator; a cooling circuit connected to the heat source; a refrigeration circuit; a high-voltage accumulator (HVA) circuit connected to the high-voltage accumulator for supplying power to an electric drivetrain of the vehicle; an ambient cooler exchanging heat and connected to the cooling circuit downstream of the heat source; a chiller transferring heat from the HVA circuit into the refrigeration circuit; and an extended HVA circuit connecting the high-voltage accumulator and the heat source in series, wherein a first switched state of the thermal system connects the HVA circuit downstream and upstream of the heat source and connects to the extended HVA circuit for heating the high-voltage accumulator using the heat source, a second switched state configures the thermal system such that: the HVA circuit cools the heat source using the chiller, the ambient cooler, or both, and is connected upstream and downstream of the chiller; and the heat source, the chiller, and the ambient cooler are connected in series, such that: the heat source is disposed upstream of the chiller; and the ambient cooler is disposed downstream of the chiller.

2. The thermal system according to claim 1, comprising: a first actuator disposed downstream of the high-voltage accumulator and setting the first switched state, comprising: a first switched position in which the HVA circuit is connected to the cooling circuit upstream of the heat source; and a second switched position in which the HVA circuit is separated from the cooling circuit or is connected downstream of the heat source.

3. The thermal system according to claim 1, wherein: the heat source is a component of the electric drivetrain of the vehicle; and the heat source is configured for generating additional heat by trimming in the first switched state.

4. The thermal system according to claim 1, further comprising: a third switched state configuring the thermal system such that: the chiller is separated from the cooling circuit; and the ambient cooler is separated from the HVA circuit.

5. The thermal system according to claim 1, further comprising: a junction is disposed upstream and downstream of the chiller to configure an HVA branch and a cooler branch, wherein the high-voltage accumulator is connected to the HVA branch; the heat source and the ambient cooler are connected to the cooler branch; and a third switched state of the thermal system connects the HVA branch and the cooler branch in parallel to cool the high-voltage accumulator via the ambient cooler by mixing coolant from the HVA branch and the cooler branch.

6. The thermal system according to claim 2, further comprising: a second actuator disposed upstream of the ambient cooler, comprising: a first switched position in which the heat source is connected in series with the ambient cooler and bypasses the chiller; and a second switched position in which the heat source, the chiller, and the ambient cooler are connected in series, wherein a third switched state connects the chiller upstream of the ambient cooler and downstream of the heat source.

7. The thermal system according to claim 1, further comprising: a third switched state configuring the thermal system such that: the heat source is connected in parallel with the high-voltage accumulator and the chiller; and the chiller is disposed downstream of the ambient cooler and upstream of the high-voltage accumulator.

8. The thermal system according to claim 7, further comprising: an actuator disposed upstream of the chiller, comprising: a first switched position in which the high-voltage accumulator is not connected in series with the ambient cooler; and a second switched position in which the ambient cooler, the chiller, and the high-voltage accumulator are connected in series.

9. The thermal system according to claim 1, wherein the ambient cooler is a first ambient cooler, and the thermal system further comprises: a cooler junction disposed downstream of the first ambient cooler from which an LT branch and an HT branch extend; and a second ambient cooler connected to the LT branch upstream of the HVA circuit, wherein: the HT branch supplies coolant for the heat source; and the LT branch is connected to the HVA circuit downstream of the chiller.

10. The thermal system according to claim 8, further comprising: a heating circuit connected to a heating heat exchanger for heating cabin air for the vehicle; and a condenser connected with the refrigeration circuit and the chiller forms a heat pump connected to the heating circuit, the heat pump transmitting heat from the chiller to the heating circuit, wherein the condenser, the heating heat exchanger, and the ambient cooler are connected in series.

11. The thermal system according to claim 10, wherein the actuator is a first actuator and the thermal system further comprises: a second actuator, comprising: a first switched position in which the heating circuit for heating the cabin air is separated from the cooling circuit; and a second switched position in which the heating circuit for dissipating heat from the heating circuit is connected to the cooling circuit.

12. The thermal system according to claim 10, further comprising: a heating circuit booster heater to feed additional heat into the heating circuit, wherein the heating circuit booster heater is disposed in the heating circuit downstream of the condenser and upstream of the heating heat exchanger.

13. The thermal system according to claim 1, further comprising: an HVA booster heater to feed additional heat into the HVA circuit, wherein the HVA booster heater is disposed in the HVA circuit downstream of the high-voltage accumulator and upstream of the chiller.

14. The thermal system according to claim 1, further comprising: an HVA check valve disposed downstream of the high-voltage accumulator for blocking the high-voltage accumulator on both sides in the event of a defect; and an HVA shut-off valve disposed upstream of the high-voltage accumulator and which is closed in a non-energized state.

15. An electric or hybrid vehicle having a thermal system according to claim 1.

16. A thermal system having a plurality of switched states for a vehicle comprising, a heat source for heating a high-voltage accumulator; a cooling circuit connected to the heat source, a refrigeration circuit; a high-voltage accumulator (HVA) circuit connected to the high-voltage accumulator for supplying power to an electric drivetrain of the vehicle; an ambient cooler exchanging heat and connected to the cooling circuit downstream of the heat source; a chiller transferring heat from the HVA circuit into the refrigeration circuit; and an extended HVA circuit connecting the high-voltage accumulator and the heat source in series, wherein a switched state of the thermal system connects the HVA circuit downstream and upstream of the heat source and connects to the extended HVA circuit for heating the high-voltage accumulator using the heat source, during a heating demand for the high-voltage accumulator: the switched state is set; a first HVA heating operation for which an HVA pump in the HVA circuit is activated; and the high-voltage accumulator is heated by exhaust heat from the heat source.

17. The thermal system according to claim 16, wherein: the heat source is a component of an electric drivetrain of the vehicle; during a heating demand for the high-voltage accumulator: the switched state is set; and the heat source is trimmed to generate exhaust heat that heats the high-voltage accumulator.

18. The thermal system according to claim 16, wherein the switched state is a first switched state and the thermal system further comprises: a second switched state set during a heat demand for the high-voltage accumulator or during a cooling demand for the heat source, or both, the second switched state configuring the thermal system such that: the HVA circuit and the cooling circuit are mutually separated; the chiller is separated from the cooling circuit; and the ambient cooler is separated from the HVA circuit, wherein the second switched state sets at least one operation mode selected from the group consisting of: a first HVA cooling operation in which the chiller is activated and coolant is conveyed in the HVA circuit to cool the high-voltage accumulator by the heat source; a homogenization operation deactivating the chiller and conveying coolant in the HVA circuit such that a temperature spread within the high-voltage accumulator is reduced; a second HVA temperature-controlling operation activating an HVA booster heater in the HVA circuit and conveying coolant in the HVA circuit such that the high-voltage accumulator is heated; and a first heat source cooling operation in which exhaust heat from the heat source is discharged to the cooling circuit.

19. The thermal system according to claim 16, wherein the switched state is a first switched state and the thermal system further comprises: a second switched state set during a cooling demand for the high-voltage accumulator, the second switched state configuring the thermal system such that: the heat source is connected in parallel with the high-voltage accumulator and the chiller; the chiller is disposed upstream of the ambient cooler and downstream of the high-voltage accumulator; and an HVA cooling operation cools the high-voltage accumulator via the chiller and the cooling circuit, or only via the cooling circuit.

20. A thermal system having a plurality of switched states for a vehicle comprising: a heat source for heating a high-voltage accumulator; a cooling circuit connected to the heat source; a refrigeration circuit; a high-voltage accumulator (HVA) circuit connected to the high-voltage accumulator for supplying power to an electric drivetrain of the vehicle; an ambient cooler exchanging heat and connected to the cooling circuit downstream of the heat source; a chiller transferring heat from the HVA circuit into the refrigeration circuit; and an extended HVA circuit connecting the high-voltage accumulator and the heat source in series, wherein a first switched state of the thermal system connects the HVA circuit downstream and upstream of the heat source and connects to the extended HVA circuit for heating the high-voltage accumulator using the heat source, a second switched state of the thermal system is set during a cooling demand for the high-voltage accumulator or for the heat source, or both, the second switched state configuring the thermal system such that: the heat source, the chiller, and the ambient cooler are connected in series; the heat source is disposed upstream of the chiller; and the ambient cooler is disposed downstream of the chiller, wherein the second switched state sets at least one operation mode selected from the group consisting of: a HVA cooling operation in which coolant is conveyed in the HVA circuit as well as in the cooling circuit and the coolant in the cooling circuit is cooled and mixed with the coolant in the HVA circuit such that the high-voltage accumulator is cooled indirectly by way of the cooling circuit; and a heat source cooling operation in which the heat source is cooled by means of the chiller.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a thermal system.

(2) FIG. 2 shows a refrigeration circuit of the thermal system.

(3) FIG. 3 shows a variant of the refrigeration circuit.

(4) FIG. 4 shows a first switched state.

(5) FIG. 5 shows a second switched state.

(6) FIG. 6 shows a third switched state.

(7) FIG. 7 shows a fourth switched state.

(8) FIG. 8 shows a comprehensive cooling circuit having a shut-off heating circuit.

(9) FIG. 9 shows the comprehensive cooling circuit having an opened heating circuit.

DETAILED DESCRIPTION OF THE DRAWINGS

(10) A thermal system 2 which is configured for use in an electric or hybrid vehicle which is not shown in more detail and is also referred to simply as the vehicle is shown in FIG. 1. The thermal system 2 has a comprehensive cooling circuit 4 as well as a refrigeration circuit 6 which is not illustrated in FIG. 1. Two variants of the refrigeration circuit 6 are shown in FIGS. 2 and 3. The thermal system 2 furthermore has a plurality of switched states, presently four of the latter. FIGS. 4 to 7 show in each case the comprehensive cooling circuit 4 in the various switched states of the thermal system 2. However, the thermal system 2 does not mandatorily have to have the combination of four switched states shown here. In a variant of the thermal system 2 (not shown here) not all of the four switched states described here are thus able to be set, on account of which corresponding simplifications result.

(11) The comprehensive cooling circuit 4 in the embodiment shown has a plurality of circuits 8, 10, 12, 14, specifically a cooling circuit 8, a high-voltage accumulator (HVA) circuit 10, an extended HVA circuit 12, and a heating circuit 14. For improved clarity, the circuits 8, 10, 12, 14 in FIG. 1 are additionally indicated by dashed lines. It becomes evident herein that the extended HVA circuit 12 has overlaps with the HVA circuit 10 and the cooling circuit 8. In principle, the heating circuit 14 can also be omitted or be separately implemented, but an integration in the comprehensive cooling circuit 4, such as in FIG. 1 for example, is advantageous.

(12) A high-voltage accumulator 16 for supplying power to an electric drivetrain of the electric or hybrid vehicle is connected to the HVA circuit 10. Furthermore, an HVA booster heater 18 is connected to the HVA circuit 10, said HVA booster heater 18 in a variant not shown however being dispensed with. Furthermore, a chiller 20 which is also connected to the refrigeration circuit 6 is connected to the HVA circuit 10. Furthermore, an HVA pump 22 for recirculating coolant is disposed in the HVA circuit 10. An HVA check valve 23 is disposed downstream of the high-voltage accumulator. An HVA shut-off valve 25 which in combination with the HVA check valve 23 fluidically encapsulates the high-voltage accumulator 16 is disposed upstream of the high-voltage accumulator 16.

(13) A heat source 24 of the vehicle is connected to the cooling circuit 8. The heat source 24 is also connected to the extended HVA circuit 12. A first ambient cooler 26 for exchanging heat with the environment is connected to the cooling circuit 8 downstream of the heat source 24. The first ambient cooler 26 in the embodiment shown is combined with a second ambient cooler 28 so as to form a cooler pack. In principle however, an embodiment without the second ambient cooler 28 is also possible. Both ambient coolers 26, 28 are disposed in succession in an ambient air path 30, wherein the second ambient cooler 28 in terms of the coolant is disposed downstream of the first ambient cooler 26, but in the ambient air path 30 is disposed upstream of the first ambient cooler 26. A fan 32 for suctioning ambient air is disposed in the ambient air path 30 downstream of the two ambient coolers 26, 28. A number of air flaps 34 for controlling the supply of ambient air are disposed upstream of the two ambient coolers 26, 28. Furthermore, a cooling circuit pump 36 is disposed in the cooling circuit 8, here so as to be downstream of the first ambient cooler 26 and upstream of the heat source 24.

(14) The heating circuit 14 serves for air-conditioning the cabin. A heating heat exchanger 38 for heating cabin air for a cabin 40 of the vehicle is connected to the heating circuit 14. Furthermore, a condenser 42 which is also connected to the refrigeration circuit 6 and conjointly with the chiller 20 forms a heat pump is connected to the heating circuit 14, said heat pump in a heat pump operation being configured for transmitting heat from the chiller 20 into the heating circuit 14. Furthermore, a heating circuit pump 44, as well as a heating circuit booster heater 46, are disposed in the heating circuit 14. The condenser 42, the heating circuit pump 44, the heating circuit booster heater 46, and the heating heat exchanger 38 in the sequence mentioned are disposed so as to be mutually downstream on a main train 48 of the heating circuit 14 in the embodiment shown. The circuit in this instance is closed by way of a return train 50 of the heating circuit 14, and a circulation of coolant is enabled by the latter. Only one check valve 52 is disposed in the return train 50. The heating circuit 14 by way of a heating circuit supply flow 54 and a heating circuit return flow 56 is connected to the cooling circuit 8 in such a manner that the main train 48 and the components connected thereto are disposed in series with the first ambient cooler 26.

(15) The HVA circuit 10 is likewise linked to the cooling circuit 8 but not to the heating circuit 14. The HVA circuit 10 upstream of the heat source 24 is connected to the cooling circuit 8 by means of a first connecting line L1, and downstream of the heat source 24 is connected by means of a second connecting line L2. The first connecting line L1 herein is connected to the HVA circuit 10 at a first connector point P1, and is connected to the cooling circuit 8 at a second connector point P2. The second connecting line L2 is connected to the HVA circuit 10 at a third connector point P3, and is connected to the cooling circuit 8 at a fourth connector point P4. The first connector point P1 and the third connector point P3 in the HVA circuit 10 are both disposed downstream of the high-voltage accumulator 16 and upstream of the chiller 20. A connection of the high-voltage accumulator 16 and the heat source 24 in series is possible by means of the connecting lines L1, L2.

(16) Furthermore, the HVA circuit 10 and the cooling circuit 8 are presently connected by means of a third connecting line L3 which in the HVA circuit 10 commences at a fifth connector point P5, downstream of the chiller 20 and upstream of the high-voltage accumulator 16, and at a six connector point P6, downstream of the heat source 24 and upstream of the first ambient cooler 26, opens into the cooling circuit 8. On account thereof, a line portion of the cooling circuit 8 between the fourth connector point P4 and the sixth connector point P6 is configured as a chiller bypass 58. A connection of the heat source 24, the chiller 20 and a first ambient cooler 26 in series can be implemented by means of the third connecting line L3. Moreover, a check valve 50 is disposed on the third connecting line L3 in the embodiment.

(17) A cooler junction 62, proceeding from which an LT branch 64 and an HT branch 66 extend, is configured downstream of the first ambient cooler 26, wherein the HT branch 66 forms a supply flow for the heat source 24, and wherein the LT branch 64 downstream of the chiller 20 is connected to the HVA circuit 10. The second ambient cooler 28 is also connected to the LT branch 64 upstream of the HVA circuit 10. In this way, the exchange of heat with the environment is significantly improved. Moreover, the heating circuit 14 is presently connected to the LT branch 64 by way of the heating circuit supply flow 56. The LT branch corresponds to the fourth connecting line already mentioned above. The HT branch is completely part of the cooling circuit.

(18) The thermal system 2 furthermore has an equalization volume 68 for the coolant. Moreover, the thermal system 2 for controlling has a control unit 70. Furthermore, temperature sensors 72 for measuring the temperature of the coolant are connected at various locations in the comprehensive cooling circuit 4.

(19) The thermal system 2 for temperature-controlling the cabin additionally has an air-conditioning evaporator 74 which is connected to the refrigeration circuit 6. As is shown in FIGS. 2 and 3, the air-conditioning evaporator 74 in the refrigeration circuit 6 is connected in parallel with the chiller 20. A self-regulating expansion valve 76 which for setting the cooling output of the air-conditioning evaporator 74 can be electrically shut off is disposed upstream of said air-conditioning evaporator 74. An expansion valve 78 is disposed upstream of the chiller 20. The heating heat exchanger 38 and the air-conditioning evaporator 74 conjointly form an air-conditioning apparatus by means of which the cabin 40 can be heated as well as cooled as well as dehumidified. The air-conditioning apparatus furthermore has an air path 80 by way of which air reaches the cabin 40.

(20) The refrigeration circuit 6 in the variants of FIGS. 2 and 3 has a compressor 82, a plurality of evaporators, specifically the air-conditioning evaporator 74 and the chiller 20, as well as the condenser 42. The expansion valve 78 ahead of the chiller 20 is presently regulated as a function of the suction pressure of the refrigerant upstream of the compressor 82. The suction pressure is measured by means of a pressure sensor 84. The monitoring of the compressor 82 in FIGS. 2 and 3 takes place as a function of the high pressure and the hot gas temperature downstream of the compressor 82, said high pressure and said hot gas temperature being measured by means of a pressure and temperature sensor 86. Regulating the compressor 82 takes place as a function of a cooling demand for the cabin 40 or for the high-voltage accumulator 16, wherein a corresponding temperature at the air side on the air-conditioning evaporator 74, or of the coolant, respectively, is used as a control variable. The refrigeration circuit 6 in FIG. 2 additionally has two internal heat exchangers 88, in each case one for the air-conditioning evaporator 74 and the chiller 20. Only one internal heat exchanger 88 for both evaporators is disposed in the variant of FIG. 3. A check valve 90 is disposed downstream of the air-conditioning evaporator 74, said check valve 90 in the variant of FIG. 2 also being able to be disposed upstream of the internal heat exchanger 88. No internal heat exchanger 88 is present in a variant not shown. Further variants which are likewise not shown are derived by the use of a plurality of chillers 20, a plurality of condensers 42, or a plurality of separate refrigeration circuits 6.

(21) Four switched states of the thermal system 2 will be explained hereunder by means of FIGS. 4 to 7. One of four switched states is in each case shown in said figures. The flow paths which result in each case for the coolant are in each case highlighted by bolder lines. Some reference signs have been omitted for reasons of clarity in FIGS. 4 to 7, but said reference signs can be derived directly from a comparison with FIG. 1.

(22) The thermal system 2 for setting a respective switched state has a first actuator 51, a second actuator S2, and a third actuator S3, said actuators in the embodiment shown in each case being configured as a 3/2-way valve. Furthermore, a fourth actuator S4 is disposed for additionally connecting and separating on demand the heating circuit 14 to and from the cooling circuit 8 independently of the current switched state, said fourth actuator S4 here being configured as a shut-off valve and being disposed in the heating circuit supply flow 56. By contrast, the fourth actuator S4 in a variant not shown is disposed in the heating circuit return flow 54.

(23) A first switched state is shown in FIG. 1. The HVA circuit 10 downstream and upstream of the heat source 24 is connected to the cooling circuit 8 such that the extended HVA circuit 12 in which the high-voltage accumulator 16 and the heat source 24 are connected in series is able to be utilized. To this end, the first actuator S1 is set to a first switched position, the second actuator S2 is set to a second switched position, and the third actuator S3 is set to a first switched position. The HVA pump 22 is activated. On account thereof, the high-voltage accumulator 16 can be heated by means of the heat source 24, and the latter can simultaneously also be cooled.

(24) The first switched state overall is presently characterized by a connection in series of the high-voltage accumulator 16, the heat source 24, and also the chiller 20. Excess heat in the extended heating circuit 12 is transmitted, for example by means of the chiller 20, to the condenser 42 in the heating circuit 14 and therein is utilized for heating the cabin or is dissipated to the first ambient cooler 26 and to the environment, depending on whether the fourth actuator S4 is opened or closed. The heating circuit pump 44 is activated to this end. In one variant, the cooling circuit pump 36 is activated and the first ambient cooler 26 is utilized directly for discharging heat.

(25) A second switched state is shown in FIG. 5. The HVA circuit 10 and the cooling circuit 8, by contrast to the first switched state, are herein mutually separated such that the chiller 20 is separated from the cooling circuit 8 and such that the first ambient cooler 26 is separated from the HVA circuit 10. To this end, the first actuator S1 is set to a second switched position, the second actuator S2 is set to a first switched position, and the third actuator S3 is set to the first switched position thereof. On account thereof, the heat source 24 and the high-voltage accumulator 16 are able to be temperature-controlled in a mutually independent manner. The second switched state, by virtue of the separation of the HVA circuit 10 and the cooling circuit 8, offers the possibility of choosing and setting various operating modes for the high-voltage accumulator 16 and the heat source 24 in a mutually independent manner. Potential operating modes are, for example, a first HVA cooling operation, a homogenization operation, a second HVA heating operation, a first heat source cooling operation. The HVA pump 22 or the cooling circuit pump 44, or both, are activated, depending on the operating mode.

(26) In the first HVA cooling operation, the chiller 20 is activated and coolant in the HVA circuit 10 is conveyed by means of the HVA pump 22 such that the high-voltage accumulator 16 is cooled by means of the chiller 20. By contrast, in the homogenization operation the chiller 20 is deactivated, but coolant continues to be conveyed by means of the HVA pump 22 such that a temperature spread within the high-voltage accumulator 16 is reduced. In the second HVA heating operation, the HVA booster heater 18 in the HVA circuit 10 is activated, and coolant is conveyed by means of the HVA pump 22 such that the high-voltage accumulator 16 is heated. Discharging of heat into the heating circuit 14 herein is additionally possible in that the chiller 20 is activated. Independently of the afore-mentioned temperature-controlling of the high-voltage accumulator 16, exhaust heat from the heat source 24 in the first heat source cooling operation is discharged by way of the cooling circuit 8 and is dissipated to the environment by way of the first ambient heat exchanger 26, for example.

(27) A third switched state is shown in FIG. 6. The HVA circuit 10 upstream and downstream of the chiller 20 is connected to the cooling circuit 8 such that the heat source 24, the chiller 20, and the first ambient cooler 26 are connected in series in such a manner that the heat source 24 is disposed upstream of the chiller 20 and the first ambient cooler 26 for cooling the heat source 24 by way of the chiller 20 or the first ambient cooler 26, or both, is disposed downstream of the chiller 20. To this end, the first actuator S1 is set to the second switched position thereof, the second actuator S2 is set to the second switched position thereof, and the third actuator S3 is set to the first switched position thereof. Furthermore, by contrast to the first and the second switched state, the third connecting line L3 but not the chiller bypass 58 is utilized in the third switched state.

(28) Indirect cooling of the high-voltage accumulator 16 by means of the first ambient cooler 26 can be implemented in a simple manner by activating the HVA pump 22, despite said two components in the third switched state not being connected in series. To this end, one junction 92 is in each case configured upstream and downstream of the chiller such that two sub-branches, specifically an HVA branch and a cooler branch, are configured. The HVA branch commences at the junction 92 downstream of the chiller 20, runs by way of the high-voltage accumulator 16, the HVA booster heater 18, and finally to the junction 92 upstream of the chiller 20. The cooler branch likewise commences at the junction 92 downstream of the chiller 20, but then runs by way of the third connecting line L3 and the second actuator S2 to the first ambient cooler 26, and from there by way of the heat source 24 to the junction 92 upstream of the chiller 20. The junctions 92 in the embodiment shown are identical to the third and the fifth connector point P3, P5, respectively. The coolant from the HVA branch and from the cooler branch parallel with the former mixes at the junction 92 upstream of the chiller 20, such that the high-voltage accumulator 16 is correspondingly cooled by means of the first ambient cooler 26.

(29) The third switched state thus enables the following two operating modes. A second heat source cooling operation, in which the heat source 24 is cooled by means of the chiller 20 and optionally, additionally by means of the first ambient cooler 26. A second HVA cooling operation, in which the HVA pump 22 is activated in addition to the cooling circuit pump 36, such that the high-voltage accumulator 16 is cooled indirectly by way of the cooling circuit 8.

(30) A fourth switched state is shown in FIG. 7. In said fourth switched state, the HVA circuit 10 upstream and downstream of the heat source 24 is connected to the cooling circuit 8 in such a manner that the heat source 24 is connected in parallel with the high-voltage accumulator 16 and the chiller 20. The chiller 20 in this instance is disposed downstream of the first ambient cooler 26 and upstream of the high-voltage accumulator 16. To this end, the first actuator S1 is set to the second switched position thereof, the second actuator S2 is set to the first switched position thereof, and the third actuator S3 is set to a second switched position. On account thereof, a third HVA cooling operation in which the high-voltage accumulator 16 is cooled by means of the chiller 20 as well as by way of the cooling circuit 8 and presently by way of both ambient coolers 26, 28 is able to be set. The first heat source cooling operation is also able to be simultaneously set.

(31) By contrast to the other three switched states, the second ambient cooler 28 is now also utilized for cooling the high-voltage accumulator 16 in the fourth switched state, that is to say that coolant emanating from the cooler junction 62 is fed to the HVA circuit 10. Two sub-branches, specifically a first sub-branch and a second sub-branch among which the coolant is correspondingly divided are configured so as to proceed from the cooler junction 62. The first sub-branch commences at the cooler junction 62, runs to the heat source 24 and thereafter terminates at the fourth connector point P4. The second sub-branch commences likewise at the cooler junction 62, but then runs by way of the second ambient cooler 28 to the third actuator S3, and from there into the HVA circuit 10 in which first the chiller 20 and thereafter the high-voltage accumulator 16 are passed through. The second sub-branch by way of the first actuator S1 then runs onward to the HVA booster heater 18, thereafter to the third connector point P3, from there by way of the second connecting line L2 and terminates likewise at the fourth connector point P4. By contrast to the first and the third switched state, the flow direction of the coolant on the second connecting line L2 is reversed in the fourth switched state.

(32) The operation of the heating circuit 14 is highlighted in FIGS. 8 and 9. FIG. 8 herein shows two switched positions of the fourth actuator S4. A first switched position of the fourth actuator S4 on account of which the heating circuit 14 is separated from the cooling circuit 8 is shown in FIG. 8. On account thereof, heating the cabin is possible as a further operating mode. Herein, either heat which reaches the heating circuit 14 by way of the heat pump is utilized, or the heating circuit booster heater 46 is activated so as to generate heat, or both. Depending on the switched state, the exhaust heat of the high-voltage accumulator 16 or of the heat source 24, or of both, is in this instance used for heating the cabin. In one variant, heat is especially generated by means of the HVA booster heater 18 and by means of a heat pump transmitted into the heating circuit 14 and therein used for heating the cabin.

(33) By contrast, FIG. 9 shows a second switched position of the fourth actuator S4, on account of which the heating circuit 14 is connected to the cooling circuit 8, in the embodiment shown especially by linking to the second sub-branch described above, the latter commencing at the cooler junction 62 and also containing the second ambient cooler 28. In this switched position it is possible for dissipating to the environment heat which reaches the heating circuit 14 from the heat pump. A mixed operation is also possible.

(34) The air-conditioning evaporator 74 is activated for cooling the cabin. A dehumidification of the cabin in this instance results by combining the cabin cooling and the cabin heating.

LIST OF REFERENCE SIGNS

(35) 2 Thermal system 4 Comprehensive cooling circuit 6 Refrigeration circuit 8 Cooling circuit 10 HVA circuit 12 Extended HVA circuit 14 Heating circuit 16 High-voltage accumulator 18 HVA booster heater 20 Chiller 22 HVA pump 23 HVA check valve 24 Heat source 25 HVA shut-off valve 26 First ambient cooler 28 Second ambient cooler 30 Ambient air path 32 Fan 34 Air flaps 36 Cooling circuit pump 38 Heating heat exchanger 40 Cabin 42 Condenser 44 Heating circuit pump 46 Heating circuit booster heater 48 Main train 50 Return train 52 Check valve 54 Heating circuit supply flow 56 Heating circuit return flow 58 Chiller bypass 60 Check valve 62 Cooler junction 64 LT branch 65 HT branch 68 Equalization volume 70 Control unit 72 Temperature sensor 74 Air-conditioning evaporator 76 Expansion valve 78 Expansion valve 80 Air path 82 Compressor 84 Pressure sensor 86 Pressure and temperature sensor 88 Internal heat exchanger 90 Check valve 92 Junction L1 First connecting line L2 Second connecting line L3 Third connecting line P1 First connector point P2 Second connector point P3 Third connector point P4 Fourth connector point P5 Fifth connector point P6 Sixth connector point S1 First actuator S2 Second actuator S3 Third actuator S4 Fourth actuator

(36) The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.