COOLING SYSTEM FOR A MOTOR VEHICLE AND METHOD FOR OPERATING A COOLING SYSTEM

Description

[0001] The present invention relates to a cooling system for a motor vehicle of the type mentioned in the preamble of claim 1.

[0002] Such cooling systems are already known in numerous design variants from the prior art. The known cooling systems for motor vehicles comprise, on the one hand, a battery subcircuit with a first coolant pump and a battery, and, on the other hand, a heating subcircuit for heating a passenger compartment of the motor vehicle with a second coolant pump, a hot air radiator, and a coolant heater for heating the coolant flowing in the heating subcircuit.

[0003] DE 11 2014 001 830 T5 discloses a vehicle thermal management system for a vehicle, comprising a first switching valve connected in parallel to at least one device in a group of multiple devices through which a thermal medium circulates, a thermal medium discharge side of a first pump, and a thermal medium discharge side of a second pump, and a second switching valve connected in parallel to the at least one device in the device group, a thermal medium intake side of the first pump, and a thermal medium intake side of the second pump. A second device is provided that must allow the thermal medium circulating through a first device included in the device group to flow through the second device.One side of a heat medium inlet side and a heat medium outlet side of the second device are connected between the first switching valve or the second switching valve and the first device. Therefore, the vehicle thermal management system can switch the heat medium circulating through the device with the simple structure.

[0004] Furthermore, EP 1 291 206 A1 relates to a heat management device for at least one first heat exchanger, in particular for a motor vehicle, comprising a primary refrigerant circuit in which a refrigerant fluid is circulated and in which at least one compressor is connected in series, a condenser, an expander and an evaporator, a secondary circuit in which a heat transfer fluid circulates and in which at least the first heat exchanger and the condenser or the evaporator are used, wherein the secondary circuit comprises circulation means for heat transfer.

[0005] Furthermore, CN 110 481 275 A discloses an integrated expansion tank for an electric vehicle with a multi-way valve, wherein the multi-way valve is fixedly connected to a housing of the expansion tank or is formed integrally with this housing. Furthermore, the housing of the expansion tank is also equipped with a cooling circuit for the electric vehicle. A plurality of communicating cooling interfaces and the multi-way valve are used to change the connection states of the plurality of cooling interfaces. The cooling circuit water pump is arranged in the cooling circuit, and the housing of the cooling circuit water pump is fixedly connected to or formed integrally with the housing of the expansion tank.

[0006] This is where the present invention comes in.

[0007] The present invention is based on the object of improving a cooling system for a motor vehicle.

[0008] This object is achieved by a cooling system for a motor vehicle having the features of claim 1, which is characterized in that the multi-way valve is designed as a five-way valve, wherein the battery subcircuit is connected in a coolant-conducting manner to a first and a second connection of the five-way valve, the heating subcircuit is connected to the first and a third connection of the five-way valve, and the chiller subcircuit is connected to a fourth and a fifth connection of the five-way valve, and wherein the first connection of the five-way valve is connected to an inlet of the first coolant pump, an outlet of the first coolant pump is connected to an inlet of the battery, an outlet of the battery is connected to the second connection of the five-way valve, the third connection of the five-way valve is connected to an inlet of the second coolant pump, an outlet of the second coolant pump is connected to an inlet of the coolant heater, an outlet of the coolant heater is connected to an inlet of the hot air radiator,An outlet of the hot air radiator is connected to the first connection of the five-way valve and the inlet of the first coolant pump, the fourth connection of the five-way valve is connected to an inlet of the chiller, and an outlet of the chiller is connected to the fifth connection of the five-way valve. The subclaims relate to advantageous developments of the invention.

[0009] A significant advantage of the invention lies in the fact that it improves a cooling system for a motor vehicle. Due to the inventive design of the cooling system for a motor vehicle, a very flexible distribution of heat flows in a cooling system for a motor vehicle can be achieved in a simple manner in terms of design, manufacturing, circuitry, and process technology. The invention enables the core functions of the cooling system according to the invention—namely, cooling the battery by means of the chiller, heating the passenger compartment by means of the coolant heater and the hot air radiator, and heating the battery by means of the coolant heater—to be implemented cost-effectively and efficiently.Furthermore, the multi-way valve, designed as a five-way valve, makes it possible to combine the circuitry required for the desired operating modes in a single multi-way valve in a particularly simple manner in terms of design and manufacturing technology. The circuitry for implementing the aforementioned core functions of the cooling system according to the invention is very simple and therefore cost-effective.

[0010] In principle, the cooling system according to the invention for a motor vehicle can be freely selected within wide, suitable limits in terms of type, mode of operation, material, and dimensions. In particular, the cooling system according to the invention can be advantageously used in motor vehicles designed as electric vehicles. Electric vehicles are generally understood here to mean all motor vehicles in which the motor vehicle is driven at least partially by a battery-powered electric motor. Accordingly, motor vehicles with so-called hybrid drives are also considered electric vehicles in the aforementioned sense.

[0011] A particularly advantageous development of the cooling system according to the invention provides that the cooling system additionally has a heat pump for air conditioning the passenger compartment, wherein the chiller is simultaneously designed as a component of the heat pump. This makes it possible to transfer heat from the environment and / or waste heat from the powertrain subcircuit to the vehicle interior, i.e. the passenger compartment, and thus enable efficient heating. This usually requires a large number of heat exchangers and refrigerant valves. The present development addresses this in that the cooling system according to the invention enables the aforementioned heat pump functions by means of the chiller and thereby reduces costs and effort in the refrigerant system of the heat pump, in particular by eliminating components in the heat pump.

[0012] A further advantageous development of the cooling system according to the invention provides that the third connection of the five-way valve and the inlet of the second coolant pump are jointly connected by means of a check valve to the inlet of the first coolant pump, the first connection of the five-way valve, and the outlet of the hot air radiator, in a coolant-conducting manner. The check valve allows coolant flow only in the direction of the third connection of the five-way valve and the inlet of the second coolant pump. This effectively protects the cooling system according to the invention against, for example, dry running and pressure surges.

[0013] Another particularly advantageous development of the cooling system according to the invention provides that the cooling system additionally has a drive train subcircuit with a third coolant pump, power electronics, an electric motor, and a cooling air radiator for cooling the coolant flowing in the drive train subcircuit, wherein the drive train subcircuit comprises a bypass line to the cooling air radiator, and wherein the battery subcircuit and / or the heating subcircuit and / or the chiller subcircuit and / or the drive train subcircuit can be selectively connected to one another in a coolant-conducting manner by means of the aforementioned multi-way valve and a further multi-way valve of the cooling system. In this way, the efficiency of the cooling system according to the invention is significantly improved.Thus, the invention is available both in the aforementioned cost-reduced variant and in a more efficient variant according to the present development, without requiring any modification of the basic system. Only minor adjustments are required to convert the cost-reduced variant into the more efficient variant of the cooling system according to the invention.

[0014] An advantageous development of the aforementioned development of the cooling system according to the invention, with reference back to claim 1 or 2, provides that the multi-way valve and the further multi-way valve are each designed as a five-way valve, wherein the battery sub-circuit is connected in a coolant-conducting manner to a first connection of the further five-way valve and a second connection of the five-way valve, the heating sub-circuit is connected to a first and a third connection of the five-way valve and a second connection of the further five-way valve, the chiller sub-circuit is connected to a fourth connection of the five-way valve and to a third connection of the further five-way valve, the drive train sub-circuit is connected to a fifth connection of the five-way valve and a fourth and a fifth connection of the further five-way valve.This makes it possible, by means of the two multi-way valves designed as five-way valves, to combine the circuit technology required for the desired operating modes, even for the more efficient variant of the cooling system according to the invention, in a particularly simple manner in terms of design and manufacturing technology.

[0015] An advantageous development of the latter embodiment of the cooling system according to the invention provides that the first connection of the five-way valve is connected to the second connection of the further five-way valve, the first connection of the further five-way valve is connected to an inlet of the first coolant pump, an outlet of the first coolant pump is connected to an inlet of the battery, an outlet of the battery is connected to the second connection of the five-way valve, the third connection of the five-way valve is connected to an inlet of the second coolant pump, an outlet of the second coolant pump is connected to an inlet of the coolant heater, an outlet of the coolant heater is connected to an inlet of the hot air radiator, an outlet of the hot air radiator is connected to the second connection of the further five-way valve, the fourth connection of the five-way valve is connected to an inlet of the chiller, an outlet of the chiller is connected to the third connection of the further five-way valve,The fourth connection of the additional five-way valve is connected to an inlet of the cooling air radiator, an outlet of the cooling air radiator is connected to an inlet of the third coolant pump, the fifth connection of the additional multi-way valve is connected via the bypass line to the inlet of the third coolant pump, an outlet of the third coolant pump is connected to an inlet of the power electronics, an output of the power electronics is connected to an inlet of the electric motor, and an output of the electric motor is connected to the fifth connection of the five-way valve. In this way, the circuitry for implementing the more efficient variant of the cooling system according to the invention is very simple and therefore cost-effective.

[0016] An advantageous development of the cooling system according to the invention according to claim 6 provides that the third connection of the five-way valve and the inlet of the second coolant pump are jointly connected by means of a check valve to the second connection of the further five-way valve and the outlet of the hot air radiator in a coolant-conducting manner, wherein the check valve allows coolant flow only in the direction of the third connection of the five-way valve and the inlet of the second coolant pump. As a result, the cooling system according to the invention according to the more efficient variant, analogous to the cost-reduced variant, is effectively protected, for example, against dry running and pressure surges.

[0017] Using the more efficient variant of the cooling system according to the invention, a first operating mode can be implemented in which the battery subcircuit and the chiller subcircuit, as well as the powertrain subcircuit and the heating subcircuit, are each connected. The first operating mode is advantageous at very high outside temperatures and / or high power output of the powertrain, since the battery can be cooled via the chiller regardless of the ambient temperature, while the waste heat from the powertrain is dissipated to the environment via the cooling air radiator.

[0018] Furthermore, the more efficient variant of the cooling system according to the invention enables a second operating mode to be implemented. This is advantageous at moderately cold outside temperatures and moderate power output of the drivetrain, since the waste heat from the drivetrain can be used directly to efficiently heat the vehicle interior, i.e., the passenger compartment. The multi-way valve is used to direct only part or all of the coolant flow from the drivetrain subcircuit through the heating subcircuit, thus heating it. Meanwhile, the battery can be cooled via the chiller, if necessary.

[0019] Furthermore, using the more efficient variant of the cooling system according to the invention, a third operating mode can be implemented, in which the battery subcircuit and the heating subcircuit, as well as the powertrain subcircuit and the chiller subcircuit, are each connected. The third operating mode is advantageous at low outside temperatures, i.e., when heating is required for the battery and / or the vehicle interior, i.e., the passenger compartment, since in this operating mode, the battery and the vehicle interior can be heated via the coolant heater. The multi-way valve is used to direct only a portion of the coolant flow from the battery subcircuit through the heating subcircuit, thus heating it.

[0020] Furthermore, the powertrain subcircuit and the chiller subcircuit are connected to transfer the waste heat from the powertrain subcircuit via the chiller to the coolant and then into the vehicle interior, i.e., the passenger compartment. The coolant is cooled in the chiller to a temperature below the ambient temperature. As a result, the coolant is reheated to ambient temperature as it flows through the cooling radiator, thus extracting the corresponding heat from the ambient air. Accordingly, the third operating mode, in addition to heating the battery and the vehicle interior, enables the use of ambient and powertrain heat in the form of a combined ambient and powertrain heat pump, provided the cooling system is used in accordance with claim 2, i.e., a cooling system with a heat pump.

[0021] A fourth operating mode can also be implemented using the more efficient variant of the cooling system according to the invention. This fourth operating mode is advantageous at very low outside temperatures, i.e. when heating is required for the battery and / or the vehicle interior, i.e. the passenger compartment, since in this fourth operating mode the battery and the vehicle interior can be heated via the coolant heater. The multi-way valve is used to direct only a portion of the coolant flow from the battery sub-circuit via the heating sub-circuit, i.e. to heat it. Furthermore, the powertrain sub-circuit and the chiller sub-circuit are connected in order to transfer the waste heat from the powertrain sub-circuit via the chiller to the coolant and then into the vehicle interior.In contrast to the third operating mode, the coolant is returned by means of the additional multi-way valve past the cooling air radiator through the bypass line directly to the third coolant pump, which is connected upstream of the power electronics and the electric motor. This is necessary at very low ambient temperatures, which are below the minimum possible coolant temperature through the chiller, and consequently prevents heat from the coolant from being released into the environment. Accordingly, the fourth operating mode, analogous to the third operating mode, enables the use of the drive train heat in the function of a drive train heat pump in addition to heating the battery and the vehicle interior, provided that the cooling system is used with reference to claim 2, i.e., a cooling system with a heat pump.

[0022] Likewise, using the more efficient variant of the cooling system according to the invention, a fifth operating mode can be implemented in which no battery temperature control is required, so that the first coolant pump is switched off. The drive train generates usable waste heat for the purpose of temperature control of the vehicle interior, i.e., the passenger compartment, which is transferred via the chiller to the heat pump, specifically to the heat pump's refrigerant system. Furthermore, the vehicle interior is additionally heated via the heating circuit using the coolant heater if the drive train heat is insufficient.

[0023] Furthermore, by means of the more efficient variant of the cooling system according to the invention, a sixth operating mode can be realized in which the battery is heated via the drive train waste heat, while the heating circuit heats the vehicle interior, i.e. the passenger compartment, by means of the coolant heating, for example electrically.

[0024] Furthermore, using the more efficient variant of the cooling system according to the invention, a seventh operating mode can be implemented in which all sub-circuits of the cooling system according to the invention are connected to one another. Initially, the powertrain sub-circuit and the heating sub-circuit are connected via the multi-way valve. Subsequently, the additional multi-way valve connects the heating sub-circuit with the battery sub-circuit. Furthermore, the multi-way valve connects the battery sub-circuit with the chiller sub-circuit. Finally, the additional multi-way valve connects the chiller sub-circuit and the powertrain sub-circuit. The seventh operating mode is advantageous in cold outside temperatures and when the powertrain is producing high power, as the waste heat from the powertrain can be used directly to efficiently heat the battery and the vehicle interior, i.e., the passenger compartment.The multi-way valve is used to direct only part or all of the coolant flow from the powertrain subcircuit through the heating subcircuit, thus heating it. The battery is then heated using the residual heat in the coolant.

[0025] The invention is explained in more detail below with reference to the attached, roughly schematic drawing. It shows: Fig. 1 shows a first exemplary embodiment of the cooling system according to the invention in a process diagram, Fig. 2 shows a second exemplary embodiment of the cooling system according to the invention in a process diagram, Fig. 3 shows the second exemplary embodiment in a first operating mode, Fig. 4 shows the second exemplary embodiment in a second operating mode, Fig. 5 shows the second exemplary embodiment in a third operating mode, Fig. 6 shows the second exemplary embodiment in a fourth operating mode, Fig. 7 shows the second exemplary embodiment in a fifth operating mode, Fig. 8 shows the second exemplary embodiment in a sixth operating mode and Fig. 9 shows the second exemplary embodiment in a seventh operating mode.

[0026] In the Fig. 1 a first embodiment of the cooling system according to the invention for a motor vehicle is shown.

[0027] The motor vehicle not shown in detail is an electric vehicle.

[0028] The cooling system 2 for circulating a coolant (not shown) in the form of a cooling liquid comprises, on the one hand, a battery subcircuit 4 with a first coolant pump 6 and a battery 8 and, on the other hand, a heating subcircuit 10 for heating a passenger compartment (not shown) of the motor vehicle with a second coolant pump 12, a hot air radiator 14 and a coolant heater 16 designed as an electric PTC heater for heating the coolant flowing in the heating subcircuit 10.

[0029] Furthermore, the cooling system 2 additionally has a chiller sub-circuit 18 with a chiller 20, wherein the battery sub-circuit 4 and / or the heating sub-circuit 10 and / or the chiller sub-circuit 18 can be selectively connected to one another in a coolant-conducting manner by means of a multi-way valve 22 of the cooling system 2.

[0030] The cooling system 2 additionally has a heat pump (not shown in detail) for air conditioning the passenger compartment, wherein the chiller 20 is simultaneously designed as a component of the heat pump.

[0031] The multi-way valve 22 is designed as a five-way valve, wherein the battery sub-circuit 4 is connected to a first and a second connection of the five-way valve 22, the heating sub-circuit 10 is connected to the first and a third connection of the five-way valve 22 and the chiller sub-circuit 18 is connected to a fourth and a fifth connection of the five-way valve 22 in a coolant-conducting manner.

[0032] Specifically, the first connection of the five-way valve 22 is connected in a coolant-conducting manner to an inlet of the first coolant pump 6, an outlet of the first coolant pump 6 is connected to an inlet of the battery 8, an outlet of the battery 8 is connected to the second connection of the five-way valve 22, the third connection of the five-way valve 22 is connected to an inlet of the second coolant pump 12, an outlet of the second coolant pump 12 is connected to an inlet of the coolant heater 16, an outlet of the coolant heater 16 is connected to an inlet of the hot air radiator 14, an outlet of the hot air radiator 14 is connected to the first connection of the five-way valve 22 and the inlet of the first coolant pump 6, the fourth connection of the five-way valve 22 is connected to an inlet of the chiller 20, and an outlet of the chiller 20 is connected to the fifth connection of the five-way valve 22.

[0033] Furthermore, the third connection of the five-way valve 22 and the inlet of the second coolant pump 12 are jointly connected by means of a check valve 24 to the inlet of the first coolant pump 6, the first connection of the five-way valve 22 and the outlet of the hot air radiator 14 in a coolant-conducting manner, wherein the check valve 24 enables a coolant flow only in the direction of the third connection of the five-way valve 22 and the inlet of the second coolant pump 12.

[0034] The first embodiment corresponds to the cost-reduced variant according to the introduction to the description, so that reference is made here to the relevant explanations in the introduction to the description.

[0035] A drive train of the motor vehicle, with power electronics, an electric motor and a cooling system with a third coolant pump, the power electronics, the electric motor and a cooling air radiator for cooling this drive train, is not operatively connected to the cooling system 2 according to the first embodiment. This is shown in the Fig. 1 by a wide dash-dotted dividing line, whereby the cooling system for the aforementioned drive train is in the image plane of the Fig. 1 to the left of the dash-dotted dividing line, while the cooling system 2 according to the first embodiment is in the image plane of the Fig. 1 shown to the right of the dotted line.

[0036] In the Fig. 2 bis 9 A second embodiment of the cooling system according to the invention is shown. Identical or equivalent components are designated by the same reference numerals as in the first embodiment.

[0037] In contrast to the first exemplary embodiment, the cooling system 2 here additionally has a drive train sub-circuit 26 with a third coolant pump 28, power electronics 30, an electric motor 32 and a cooling air radiator 34 for cooling the coolant flowing in the drive train sub-circuit 26, wherein the drive train sub-circuit 26 comprises a bypass line 36 to the cooling air radiator 34, and wherein the battery sub-circuit 4 and / or the heating sub-circuit 10 and / or the chiller sub-circuit 18 and / or the drive train sub-circuit 26 can be selectively connected to one another in a coolant-conducting manner by means of the aforementioned multi-way valve 22 and a further multi-way valve 38 of the cooling system 2.

[0038] The multi-way valve 22 and the further multi-way valve 38 are each designed here as a five-way valve, wherein the battery sub-circuit 4 is connected in a coolant-conducting manner to a first connection of the further five-way valve 38 and a second connection of the five-way valve 22, the heating sub-circuit 10 is connected to a first and a third connection of the five-way valve 22 and a second connection of the further five-way valve 38, the chiller sub-circuit 18 is connected to a fourth connection of the five-way valve 22 and to a third connection of the further five-way valve 38, the drive train sub-circuit 26 is connected to a fifth connection of the five-way valve 22 and a fourth and a fifth connection of the further five-way valve 38.

[0039] Specifically, the first connection of the five-way valve 22 is connected to the second connection of the further five-way valve 38, the first connection of the further five-way valve 38 is connected to an inlet of the first coolant pump 6, an outlet of the first coolant pump 6 is connected to an inlet of the battery 8, an outlet of the battery 8 is connected to the second connection of the five-way valve 22, the third connection of the five-way valve 22 is connected to an inlet of the second coolant pump 12, an outlet of the second coolant pump 12 is connected to an inlet of the coolant heater 16, an outlet of the coolant heater 16 is connected to an inlet of the hot air radiator 14, an outlet of the hot air radiator 14 is connected to the second connection of the further five-way valve 38, the fourth connection of the five-way valve 22 is connected to an inlet of the chiller 20, an outlet of the chiller 20 is connected to the third connection of the further five-way valve 38, the fourth connection of the further five-way valve 38 is connected to an inlet of the cooling air radiator 34,an outlet of the cooling air radiator 34 is connected to an inlet of the third coolant pump 28, the fifth connection of the further multi-way valve 38 is connected to the inlet of the third coolant pump 28 by means of the bypass line 36, an outlet of the third coolant pump 28 is connected to an inlet of the power electronics 30, an outlet of the power electronics 30 is connected to an inlet of the electric motor 32, and an outlet of the electric motor 32 is connected to the fifth connection of the five-way valve 38 in a coolant-conducting manner.

[0040] Furthermore, the third connection of the five-way valve 22 and the inlet of the second coolant pump 12 are jointly connected by means of the check valve 24 to the second connection of the further five-way valve 38 and the outlet of the hot air radiator 14 in a coolant-conducting manner, wherein the check valve 24 enables a coolant flow only in the direction of the third connection of the five-way valve 22 and the inlet of the second coolant pump 12.

[0041] The second embodiment corresponds to the more efficient variant according to the introduction to the description, so that reference is made here to the relevant explanations in the introduction to the description.

[0042] In the following, the functioning of the cooling system according to the invention according to the present first and second embodiment is explained with reference to the Fig. 1 bis 9 explained in more detail. Coolant flows are in the respective Fig. 3 bis 9 represented by solid and dashed lines with a greater line thickness than the other lines, as well as arrows to indicate the flow direction.

[0043] By means of the cost-reduced variant, i.e., the invention according to the first exemplary embodiment, it is possible, depending on an operating mode set by means of the multi-way valve 22 from a plurality of operating modes of the cooling system 2, to cool the battery 8 by means of the chiller 20 and / or to heat the passenger compartment by means of the coolant heater 16 and the hot air radiator 14 and / or to heat the battery 8 by means of the coolant heater 16. Accordingly, by means of the cost-reduced variant of the invention, i.e., the first exemplary embodiment, the core functions of the cooling system 2 can be performed with lower efficiency compared to the second exemplary embodiment.In addition, the more efficient variant of the invention according to the second embodiment enables the following: Depending on the operating mode of the cooling system 2 set by means of the multi-way valve 22 and the further multi-way valve 38 from a plurality of operating modes, the battery sub-circuit 4 is connected to the chiller sub-circuit 18 and the drive train sub-circuit 26 is connected to the heating sub-circuit 10 in a coolant-conducting manner. For example, by the coolant flowing in the drive train sub-circuit 26 flowing through the cooling air radiator 34 and / or by the coolant flowing in the heating sub-circuit 10 being partially or completely bypassed by means of a further bypass line 40 of the cooling system 2 to the coolant heater 16 and the heating air radiator 14. See the . Fig. 3 and 4, in which the first and second operating modes of the cooling system 2 are shown according to the introduction to the description.

[0044] It should be noted that the cooling system 2 according to the first embodiment also has a further bypass line 40. See the Fig. 1 .

[0045] Depending on the operating mode of the cooling system 2 set by means of the multi-way valve 22 and the further multi-way valve 38, the battery subcircuit 4 is simultaneously connected to the heating subcircuit 10 and the drive train subcircuit 26 is simultaneously connected to the chiller subcircuit 18 in a coolant-conducting manner, for example in such a way that the coolant flowing in the drive train subcircuit 26 flows through the cooling air radiator 34 and / or that the coolant flowing in the heating subcircuit 10 is partially or completely bypassed by means of the further bypass line 40 of the cooling system 2 to the coolant heater 16 and the heating air radiator 14. See the Fig. 5 and 6 , in which the third and fourth operating modes of the cooling system 2 are shown according to the introduction to the description.

[0046] Furthermore, depending on the operating mode of the cooling system 2 set by means of the multi-way valve 22 and the further multi-way valve 38, the drive train subcircuit 26 and the chiller subcircuit 18 or the battery subcircuit 4, the drive train subcircuit 26 and the chiller subcircuit 18 are simultaneously connected in a coolant-conducting manner and the coolant in the heating subcircuit 10 is circulated independently of the battery subcircuit 4, the drive train circuit 10 and the chiller subcircuit 18. See the Fig. 7 and 8 , in which the fifth and sixth operating modes of the cooling system 2 are shown according to the introduction to the description.

[0047] In addition, depending on the operating mode of the cooling system 2 set by means of the multi-way valve 22 and the further multi-way valve 38, the battery subcircuit 4, the chiller subcircuit 18, the drive train subcircuit 26 and the heating subcircuit 10 are simultaneously connected to one another in a coolant-conducting manner, for example in such a way that the coolant flowing in the drive train subcircuit 26 flows through the cooling air radiator 34, and / or that the coolant flowing in the heating subcircuit 10 is partially or completely bypassed by means of the further bypass line 40 of the cooling system 2 to the coolant heater 16 and the heating air radiator 14. See the Fig. 9 , in which the seventh operating mode of the cooling system 2 is shown according to the introduction to the description.

[0048] With regard to the aforementioned embodiments according to the first and second embodiments and the aforementioned operating modes, reference is again made to the relevant statements in the introduction to the description.

[0049] Due to the inventive design of the cooling system 2, a very flexible distribution of heat flows in the cooling system 2 of the motor vehicle, namely the electric vehicle, can be realized in a simple manner in terms of design, manufacturing, circuitry, and process technology. This allows the core functions of the cooling system 2—namely, cooling the battery 8 by means of the chiller 20, heating the passenger compartment by means of the coolant heater 16 and the hot air radiator 14, and heating the battery 8 by means of the coolant heater 16—to be implemented cost-effectively and efficiently. In addition, the efficiency of the cooling system 2 according to the second exemplary embodiment is significantly improved compared to the efficiency of the more cost-effective first exemplary embodiment. Thus, the invention is available in both a cost-reduced variant and a more efficient variant, without requiring modification of the basic system.Only minor adjustments are required to convert the cost-reduced variant into the more efficient variant of cooling system 2.

[0050] However, the invention is not limited to the present embodiments. For example, the invention can also be advantageously used in other types of motor vehicles. List of reference symbols

[0051] 2 Cooling system 4 Battery subcircuit 6 First coolant pump 8 Battery 10 Heating subcircuit 12 Second coolant pump 14 Hot air radiator 16 Coolant heater 18 Chiller subcircuit 20 Chiller 22 Multi-way valve 24 Check valve 26 Drive train subcircuit 28 Third coolant pump 30 Power electronics 32 Electric motor 34 Cooling air radiator 36 Bypass line 38 Additional multi-way valve 40 Additional bypass line

Claims

1. A cooling system (2) for a motor vehicle for circulating a coolant, comprising on the one hand a battery subcircuit (4) with a first coolant pump (6) and a battery (8), and on the other hand a heating subcircuit (10) for heating a passenger compartment of the motor vehicle with a second coolant pump (12), a heating air radiator (14) and a coolant heater (16) for heating the coolant flowing in the heating subcircuit (10), said cooling system (2) additionally having a chiller subcircuit (18) with a chiller (20), wherein the battery subcircuit (4) and / or the heating subcircuit (10) and / or the chiller subcircuit (18) can be selectively connected to one another by means of a multi-port valve (22) of the cooling system (2) in a coolant-conducting manner, characterized in that the multi-port valve (22) is designed as a five-way valve, with the battery subcircuit (4) being connected to a first and a second connection of the five-way valve (22), the heater subcircuit (10) being connected to the first and a third connection of the five-way valve (22) and the chiller subcircuit (18) being connected to a fourth and a fifth connection of the five-way valve (22) in a coolant-conducting manner, whereby the first connection of the five-way valve (22) is connected to an inlet of the first coolant pump (6), an outlet of the first coolant pump (6) is connected to an inlet of the battery (8), an outlet of the battery (8) is connected to the second connection of the five-way valve (22), the third connection of the five-way valve (22) is connected to an inlet of the second coolant pump (12), an outlet of the second coolant pump (12) is connected to an inlet of the coolant heater (16), an outlet of the coolant heater (16) is connected to an inlet of the heating air radiator (14), an outlet of the heating air radiator (14) is connected to the first connection of the five-way valve (22) and the inlet of the first coolant pump (6), the fourth connection of the five-way valve (22) is connected to an inlet of the chiller (20) and an outlet of the chiller (22) is connected to the fifth connection of the five-way valve (22) in a coolant-conducting manner.

2. A cooling system (2) according to claim 1, characterized in that the cooling system (2) additionally has a heat pump for air conditioning the passenger compartment, with the chiller (20) being simultaneously designed as a component of the heat pump.

3. A cooling system (2) according to claim 1 or 2, characterized in that the third connection of the five-way valve (22) and the inlet of the second coolant pump (12) are together connected by means of a non-return valve (24) to the inlet of the first coolant pump (6), the first connection of the five-way valve (22) and the outlet of the heating air radiator (14) in a coolant-conducting manner, with the non-return valve (24) enabling a coolant flow only in the direction of the third connection of the five-way valve (22) and the inlet of the second coolant pump (12).

4. A cooling system (2) according to one of claims 1 to 3, characterized in that the cooling system (2) additionally has a powertrain subcircuit (26) with a third coolant pump (28), power electronics (30), an electric motor (32) and a cooling air radiator (34) for cooling the coolant flowing in the powertrain subcircuit (26), said powertrain subcircuit (26) comprising a bypass line (36) to the cooling air radiator (34), whereby the battery subcircuit (4) and / or the heater subcircuit (10) and / or the chiller subcircuit (18) and / or the powertrain subcircuit (26) can be selectively connected to one another by means of the aforementioned multi-port valve (22) and a further multi-port valve (38) of the cooling system (2) in a coolant-conducting manner.

5. A cooling system (2) according to claim 4, referring back to claim 1 or 2, characterized in that the multi-port valve (22) and the further multi-port valve (38) are each designed as a five-way valve, with the battery subcircuit (4) being connected to a first connection of the further five-way valve (38) and to a second connection of the five-way valve (22), the heater subcircuit (10) being connected to a first and a third connection of the five-way valve (22) and to a second connection of the further five-way valve (38), the chiller subcircuit (18) being connected to a fourth connection of the five-way valve (22) and to a third connection of the further five-way valve (38), the powertrain subcircuit (26) being connected to a fifth connection of the five-way valve (22) and to a fourth and a fifth connection of the further five-way valve (38) in a coolant-conducting manner.

6. A cooling system (2) according to claim 5, characterized in that the first connection of the five-way valve (22) is connected to the second connection of the further five-way valve (38), the first connection of the further five-way valve (38) is connected to an inlet of the first coolant pump (6), an outlet of the first coolant pump (6) is connected to an inlet of the battery (8), an outlet of the battery (8) is connected to the second connection of the five-way valve (22), the third connection of the five-way valve (22) is connected to an inlet of the second coolant pump (12), an outlet of the second coolant pump (12) is connected to an inlet of the coolant heater (16), an outlet of the coolant heater (16) is connected to an inlet of the heating air radiator (14), an outlet of the heating air radiator (14) is connected to the second connection of the further five-way valve (38), the fourth connection of the five-way valve (22) is connected to an inlet of the chiller (20), an outlet of the chiller (20) is connected to the third connection of the further five-way valve (38), the fourth connection of the further five-way valve (38) is connected to an inlet of the cooling air radiator (34), an outlet of the cooling air radiator (34) is connected to an inlet of the third coolant pump (28), the fifth connection of the further multi-port valve (38) is connected by means of the bypass line (36) to the inlet of the third coolant pump (28), an outlet of the third coolant pump (28) is connected to an inlet of the power electronics (30), an outlet of the power electronics (30) is connected to an inlet of the electric motor (32), an outlet of the electric motor (32) is connected to the fifth connection of the five-way valve (22) in a coolant-conducting manner.

7. A cooling system (2) accordance to claim 6, characterized in that the third connection of the five-way valve (22) and the inlet of the second coolant pump (12) are together connected by means of a non-return valve (24) to the second connection of the further five-way valve (38) and the outlet of the heating air radiator (14) in a coolant-conducting manner, with the non-return valve (24) enabling a coolant flow only in the direction of the third connection of the five-way valve (22) and the inlet of the second coolant pump (12).