Thermal management system for an electric vehicle and method for operating the same

Abstract

The invention relates to a thermal management system (2) for an electrically operated vehicle, comprising a control unit (4), a battery circuit (8) in heat transfer connection with a drive battery (6) of the electrically operated vehicle, a drive circuit (14) in heat transfer connection with an electric drive (10) of the electrically operated vehicle and / or with power electronics (12) for an electric drive (10), and an air conditioning circuit (16) in heat transfer connection with a vehicle interior of the electrically operated vehicle, wherein, on the one hand, the battery circuit (8) and the drive circuit (14) are each operable with a coolant and are connectable or disconnectable to one another by means of at least one controllable coolant valve (18), and, on the other hand, the air conditioning circuit (16) is operable with a refrigerant which is different from the coolant, characterized in that a heat transfer connection between, on the one hand, the battery circuit (8) and / or the drive circuit (14) and, on the other hand, the air conditioning circuit (16) is establishable or disconnectable by means of at least one heat exchange device (24) of the thermal management system (2) depending on a control of the coolant valve (18) and a control of the heat exchange device (24) by means of the control unit (4). Furthermore, the invention relates to a method for operating a thermal management system (2).

Description

TECHNICAL FIELD

[0001] The present application relates to a thermal management system for an electrically operated vehicle and to a method for operating the thermal management system. BACKGROUND

[0002] Such a thermal management system for an electrically operated vehicle and a method for operating the thermal management system are known in the prior art in various embodiments and comprise a control unit, a battery circuit in heat transfer connection with a drive battery of the electrically operated vehicle, a drive circuit in heat transfer connection with an electric drive of the electrically operated vehicle and / or a power electronics for the electric drive, and an air conditioning circuit in heat transfer connection with a vehicle interior of the electrically operated vehicle, wherein the battery circuit and the drive circuit are each operable with a coolant and are connectable or disconnectable to one another by means of at least one controllable coolant valve, and the air conditioning circuit is operable with a refrigerant which is different from the coolant. SUMMARY

[0003] The present application is based on this.

[0004] It is the task of the present application to improve a thermal management system for an electrically operated vehicle and a method for operating the thermal management system.

[0005] This task is solved by a thermal management system for an electrically operated vehicle according to the present application, characterized in that

[0006] According to the control of the coolant valve and the control of the heat exchange device by means of the control unit, a heat transfer connection between the battery circuit and / or the drive circuit on the one hand and the air conditioning circuit on the other hand can be established or disconnected by means of at least one heat exchange device of the thermal management system. Thus, the above-mentioned heat transfer connection can be established or disconnected between the air conditioning circuit with refrigerant on the one hand and at least one of the above-mentioned coolant circuits, i.e. the battery circuit and / or the drive circuit, on the other hand. Furthermore, this task is solved by a method for operating a thermal management system for an electrically operated vehicle according to the present application. The electrically operated vehicle can in particular be a motor vehicle for road traffic. Furthermore, the electrically operated vehicle can be freely selected within wide suitable limits and can be constructed, for example, as a vehicle with only an electric drive or as a vehicle with a so-called hybrid drive, i.e. an electric drive and an internal combustion engine.

[0007] The invention relates to a thermal management system for an electrically operated vehicle, comprising a control unit, a battery circuit in heat transfer connection with a drive battery of the electrically operated vehicle, a drive circuit in heat transfer connection with an electric drive of the electrically operated vehicle and / or with power electronics for the electric drive, and an air conditioning circuit in heat transfer connection with a vehicle interior of the electrically operated vehicle, wherein, on the one hand, the battery circuit and the drive circuit are each operable with a coolant and are connectable or disconnectable to one another by means of at least one controllable coolant valve, and, on the other hand, the air conditioning circuit is operable with a refrigerant which is different from the coolant, characterized in that a heat transfer connection between, on the one hand, the battery circuit and / or the drive circuit and, on the other hand, the air conditioning circuit is connectable or disconnectable by means of at least one heat exchange device of the thermal management system depending on a control of the coolant valve and a control of the heat exchange device by means of the control unit, wherein the heat exchange device has at least one refrigerant valve and at least one heat exchanger, wherein the heat exchanger is flowable or not flowable by the refrigerant depending on a control of the refrigerant valve by means of the control unit, and wherein, in the air conditioning circuit, in addition to the heat exchange device, a cooler, an evaporator, a liquefier, an accumulator, a compressor and a valve are arranged, such that the cooler is arranged not only in the battery circuit but also in the air conditioning circuit and, similar to the heat exchange device, a heat transfer connection between, on the one hand, the air conditioning circuit and, on the other hand, the battery circuit is connectable or disconnectable by means of the cooler depending on a control of the coolant valve and a control of the valve by means of the control unit, such that the cooler is flowable or not flowable by the refrigerant depending on a control of the valve by means of the control unit, wherein the thermal management system is configured in such a way that not only the heat exchanger but also the cooler can be used simultaneously for transferring waste heat of the drive circuit and waste heat of the battery circuit for heating the vehicle interior of the electrically operated vehicle.

[0008] The main advantages of the invention lie, inter alia, in the improved thermal management system for an electrically operated vehicle and the method for operating the thermal management system. Based on the configuration according to the invention of the thermal management system for an electrically operated vehicle and the method for operating the thermal management system, an effective temperature control of the electrically operated vehicle, i.e. of the drive battery, the electric drive and / or the power electronics for the electric drive and / or of the vehicle interior of the electrically operated vehicle, can be achieved while simplifying the structure of the thermal management system. Accordingly, for example, an air-refrigerant-condenser in the vehicle front of the electrically operated vehicle is not necessary. Furthermore, the thermal management system according to the invention can be realized with less design and manufacturing effort and at lower costs. The system structure according to the invention is generally significantly simplified compared to conventional solutions.

[0009] In principle, the thermal management system can be freely chosen within wide suitable limits with respect to the type of components, the mode of operation, the materials, the dimensions and the number and the arrangement of these with respect to each other and with respect to the rest of the electric vehicle.

[0010] An advantageous refinement of the thermal management system according to the application provides that the heat exchange device has at least one refrigerant valve and at least one heat exchanger, wherein the heat exchanger can or cannot be traversed by refrigerant depending on the actuation of the refrigerant valve by means of the control unit. In this way, the establishment or disconnection of a heat transfer connection between the air conditioning circuit on the one hand and at least one of the coolant circuits, i.e. the battery circuit and / or the drive circuit, on the other hand can be controlled in a simple manner. Furthermore, the heat transfer connection between the heat exchanger described above and the rest of the air conditioning circuit and also between the heat exchanger and the vehicle interior to be tempered can also be controlled in a simple manner by means of the at least one refrigerant valve.

[0011] The concepts "control unit" and "controllable" are to be interpreted broadly according to the application and also include a regulating unit or a combination of a control unit and a regulating unit.

[0012] A particularly advantageous refinement of the thermal management system according to the application provides that the thermal management system additionally has a coolant-operated heat transfer circuit, wherein at least one of the at least one heat exchanger is arranged in the heat transfer circuit, such that a heat transfer connection between the coolant flowing in the heat transfer circuit and the refrigerant can be established or can be disconnected by means of the heat exchanger, and the heat transfer circuit can be connected or can be disconnected with the battery circuit and / or the drive circuit by means of at least one further coolant valve which can be actuated by means of the control unit, preferably the coolant valve is configured at the same time as the further coolant valve. Thereby, an additional degree of freedom in establishing or disconnecting a heat transfer connection between the air conditioning circuit on the one hand and at least one of the coolant circuits on the other hand can be achieved.

[0013] Correspondingly, an advantageous refinement of the method according to the application provides that the heat transfer circuit is connected or disconnected with the battery circuit and / or the drive circuit by means of the actuation of the further coolant valve by means of the control unit.

[0014] Thus, a complex thermal management system can also be realized in a structurally, technologically and circuit-technically simple manner and method. On the other hand, the use of the heat transfer circuit described above makes it possible to establish or disconnect additional heat transfer connections of the heat exchanger arranged in the heat transfer circuit, for example, to the free environment and / or to a further coolant circuit of the electric vehicle and / or to a further refrigerant circuit of the electric vehicle.

[0015] Accordingly, an advantageous further development of the aforementioned embodiments of the thermal management system according to the application provides that the heat transfer circuit is configured in such a way that a heat transfer connection between the coolant flowing in the heat transfer circuit and the free environment can be established or can be interrupted by means of the heat transfer circuit, preferably the heat transfer to the free environment can be realized by means of the at least one heat exchanger arranged in the heat transfer circuit. By means of a preferred embodiment of this further development, this can be technically realized, for example, also without an additional heat exchanger. However, it is also conceivable that in this further development an additional heat exchanger is used in the heat transfer circuit alternatively or in addition to the heat exchanger.

[0016] A further advantageous further development of the thermal management system according to the application provides that the heat exchange device and / or the coolant valve and / or the further coolant valve are / is configured in coordination with one another in such a way that on the one hand the battery circuit and / or the drive circuit can be heated and / or can be cooled by means of on the other hand the heat exchange device and the air conditioning circuit and / or the heat transfer circuit, and / or on the one hand the air conditioning circuit can be heated and / or can be cooled by means of on the other hand the heat exchange device and the battery circuit and / or the drive circuit and / or the heat transfer circuit. Thereby, a plurality of applications of the thermal management system according to the application for tempering an electrically powered vehicle is realized, so that a plurality of application cases can be covered.

[0017] A further advantageous further development of the thermal management system according to the application provides that the thermal management system has at least one bypass device in the battery circuit and / or in the drive circuit and / or in the air conditioning circuit and / or in the heat transfer circuit, the bypass device having at least one bypass line and at least one controllable bypass valve, wherein by means of the respective bypass device, depending on the control of the bypass valve by means of the control unit, it is possible for a heat exchanger arranged in the respective circuit to be bypassed or not to be bypassed. In this way, the functional complexity of the thermal management system according to the application and the demand-oriented tempering of the individual circuits is further improved.

[0018] Accordingly, a further advantageous further development of the method according to the application provides that, depending on the control of the bypass valve, a heat exchanger arranged in the respective circuit having a bypass device is bypassed or not bypassed.

[0019] Furthermore, a particularly advantageous refinement of the method according to the application provides that the actuation of the coolant valve and / or the heat exchange device and / or the further coolant valve and / or the bypass valve and / or of a pump which can be actuated by means of the control unit is carried out in one of the coolant circuits in order to transport the coolant in the coolant circuit in dependence on the vehicle state of the electric vehicle and / or the driving state of the electric vehicle and / or at least one environmental condition of the free environment for transporting the coolant in the coolant circuit. Thereby, the temperature control of the electric vehicle can be adapted very simply in terms of circuit technology to the respective prevailing conditions when using the electric vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0020] The application is explained in more detail below by means of the attached rough sketches. Therein, it is shown:

[0021] Figure 1 a first embodiment of a thermal management system according to the application for an electric vehicle is shown in a block diagram,

[0022] Figure 2 the first embodiment in a first operating mode is shown,

[0023] Figure 3 the first embodiment in a second operating mode is shown,

[0024] Figure 4 a second embodiment of a thermal management system according to the application for an electric vehicle is shown in a block diagram, and

[0025] Figure 5 a third embodiment of a thermal management system according to the application for an electric vehicle is shown in a block diagram. DETAILED DESCRIPTION

[0026] In Figures 1 to 3 a first embodiment of a thermal management system according to the application for an electric vehicle for carrying out the method according to the application is shown purely exemplarily.

[0027] The electric vehicle, which is not shown, is configured as a purely electric vehicle in the present embodiment.

[0028] A thermal management system 2 for an electrically operated vehicle comprises a control unit 4, a battery circuit 8 in heat transfer connection with a drive battery 6 of the electrically operated vehicle, a drive circuit 14 in heat transfer connection with an electric drive 10 of the electrically operated vehicle and with power electronics 12 for the electric drive 10, and an air conditioning circuit 16 in heat transfer connection with a not shown vehicle interior of the electrically operated vehicle, wherein on the one hand the battery circuit 8 and the drive circuit 14 are each operable with a not shown coolant and are connectable or disconnectable to one another by means of at least one controllable coolant valve 18, and on the other hand the air conditioning circuit 16 is operable with a not shown refrigerant which is different from the coolant. The coolant valve 18 is configured as a single multi-way directional valve in the present embodiment. However, other configuration variants of the at least one coolant valve are also conceivable. For example, the at least one coolant valve can be configured as a plurality of valves which are connected to one another in a manner known to the person skilled in the art.

[0029] In the battery circuit 8, in addition to the drive battery 6, a PTC heating unit 20, a cooler 22, i.e. a so-called chiller, and a coolant pump 23 are arranged. The drive battery 6 is used to supply electric current to the electric drive 10 in a manner known to the person skilled in the art. The electric drive 10 is configured for the travel motion of the electrically operated vehicle in a manner known to the person skilled in the art. The drive circuit 14 comprises a coolant pump 13 in analogy to the battery circuit 8, in addition to the electric drive 10 and the corresponding power electronics 12.

[0030] Between the battery circuit 8 and / or the drive circuit 14 on the one hand and the air conditioning circuit 16 on the other hand, a heat transfer connection can be established or can be disconnected by means of at least one heat exchange device 24 of the thermal management system 2 depending on the control of the coolant valve 18 and the control of the heat exchange device 24 by means of the control unit 4. This is explained in more detail below. The heat exchange device 24 has two refrigerant valves 26, 28 and a heat exchanger 30, wherein the heat exchanger 30 can or can not be traversed by refrigerant depending on the control of the refrigerant valves 26, 28 by means of the control unit 4. The refrigerant valves 26, 28 are each configured as 3 / 2 directional valves here. Alternatively, the two 3 / 2 directional valves 26, 28 can be replaced by a single 6 / 2 directional valve. Of course, other variants are also conceivable. For this purpose, for example, reference is also made to the second embodiment according to Figure 4 .

[0031] Furthermore, as can be seen from Figure 1As shown in the middle, in the air-conditioning circuit 16, in addition to the heat exchanger 24, a cooler 22, an evaporator 32, a liquefier 34, an accumulator 36, a compressor 38 and two valves 40, 42 are arranged. The cooler 22 is correspondingly arranged not only in the battery circuit 8 but also in the air-conditioning circuit 16. Analogously to the heat exchanger 24, by means of the cooler 22, depending on the actuation of the coolant valve 18 and of the valve 40 by means of the control unit 4, a heat transfer connection between the air-conditioning circuit 16 on the one hand and the battery circuit 8 on the other hand can be established or can be interrupted. The cooler 22 can or can not be traversed by refrigerant depending on the actuation of the valve 40 by means of the control unit 4. In this regard, reference is made to Figure 1 . The other functions of the air-conditioning circuit 16 can correspond in other respects to the functions of a common refrigerant circuit.

[0032] The heat management system 2 in the present embodiment additionally comprises a coolant-operated heat transfer circuit 44, wherein the heat exchanger 30 is arranged in the heat transfer circuit 44 in such a way that a heat transfer connection between a not shown coolant flowing in the heat transfer circuit 44 and the refrigerant can be established or can be interrupted by means of the heat exchanger 30. The heat exchanger 30 is correspondingly arranged not only in the heat transfer circuit 44 but also in the air-conditioning circuit 16. The heat transfer circuit 44 can be connected or can be interrupted with the battery circuit 8 and / or the drive circuit 14 by means of at least one further coolant valve which is actuable by means of the control unit 4, wherein the coolant valve 18 is configured as the further coolant valve at the same time. Furthermore, in the heat transfer circuit 44, in addition to the heat exchanger 30 of the heat exchanger device 24, a coolant pump 46, a heat exchanger 48 configured as a radiator and two non-return valves 50, 52 are arranged analogously to the battery circuit 8 and the drive circuit 14. The heat transfer circuit 44 is configured by means of the heat exchanger 48 configured as a radiator in such a way that a heat transfer connection between the coolant flowing in the heat transfer circuit 44 and a not shown free environment can be established or can be interrupted.

[0033] The heat exchanger device 24 and the coolant valve 18 are configured in coordination with one another in such a way that the battery circuit 8 and / or the drive circuit 14 on the one hand can be heated and / or can be cooled by means of the heat exchanger device 24, the air-conditioning circuit 16 and the heat transfer circuit 44 on the other hand and vice versa, i.e. the air-conditioning circuit 16 on the one hand can be heated and / or can be cooled by means of the heat exchanger device 24 and the battery circuit 8 and / or the drive circuit 14 and the heat transfer circuit 44 on the other hand.

[0034] To meet the functional complexity of the thermal management system according to the present embodiment, the thermal management system 2 has a bypass device 54 with a bypass line 56 and two controllable bypass valves in the air-conditioning circuit 16, wherein the refrigerant valves 26, 28 are configured as bypass valves here. By means of the bypass device 54, the heat exchanger 30 arranged in the air-conditioning circuit 16 can be flowed through or not flowed through in a desired manner depending on the actuation of the refrigerant valves 26, 28 by means of the control unit 4.

[0035] The coolant valve 18 described above and / or the refrigerant valves 26, 28 described above and / or the valves 40, 42 can be configured here and can be actuated by means of the control unit 4 such that the respective valve 18, 26, 28, 40, 42 not only shuts off or releases the coolant line of one of the coolant circuits 8, 14, 44 or the refrigerant line of the refrigerant circuit 16, but it can also be provided that at least one of the valves 18, 26, 28, 40, 42 partially shuts off or opens the corresponding coolant line or refrigerant line, so that the coolant or refrigerant flowing therein flows in the coolant line or refrigerant line with a reduced volume flow, i.e. throttled. Accordingly, a mixture of coolants having different temperature levels can also be set by means of the valves 18, 26, 28, 40, 42 described above. The same applies to the refrigerant.

[0036] The following describes the working method of the thermal management system according to the present embodiment and the method for operating the thermal management system according to the present invention by means of Figures 1 to 3 The working method of the thermal management system according to the present invention and the method for operating the thermal management system according to the present invention are described in more detail.

[0037] With the aid of the thermal management system 2 of the electrically driven vehicle it is possible to cool the battery circuit 8 with the aid of the cooler 22 and to heat the battery circuit with the aid of the PTC heater 20. The waste heat of the drive battery 6 can be used for heating the vehicle interior, wherein the waste heat and / or the heat generated by the PTC heater 20 can be transferred to the air conditioning circuit 16 by means of the cooler 22. The waste heat from the drive circuit 14, i.e. the power electronics 12 and the electric drive 10, can be output to the coolant for subsequent discharge to the heat transfer circuit 44 and / or the battery circuit 8 for direct heating of the drive battery 6 and / or for heating the vehicle interior with the aid of the cooler 22. The air conditioning circuit 16 can be used for cooling the vehicle interior with the aid of the evaporator 32 and for heating the vehicle interior with the aid of the condenser 34. In the present embodiment, the heat transfer circuit 44 is used for cooling and heating the battery circuit 8 and / or the drive circuit 14 and / or for cooling and heating the interior with the aid of the air conditioning circuit 16. Here, cooling takes place, for example, with the aid of the heat exchanger 48 configured as a radiator, i.e. by heat output to the free environment, and / or with the aid of the heat exchanger 30. Here, heating takes place, for example, with the aid of the heat exchanger 48 configured as a radiator, i.e. by heat absorption from the free surroundings, and / or with the aid of the heat exchanger 30.

[0038] Depending on the state of the respective coolant circuit 8, 14 or refrigerant circuit 16 and in consideration of the vehicle state and / or driving situation and / or environmental conditions, for example the ambient temperature, the different circuits 8, 14, 16, 44 can be heat sources or heat sinks.

[0039] The efficiency of the thermal management system 2 as a whole can be improved according to the application by the need- appropriate thermotechnical connection or separation of the individual circuits 8, 14, 16, 44. For example, during driving of the electrically driven vehicle, the drive battery 6 can be effectively warmed up in the cold state by the waste heat of the electric drive 10. For this purpose, the battery circuit 8 must be connected with the drive circuit 14 by means of the coolant valve 18 in such a way that the coolant is guided. However, at very high ambient temperatures, the battery circuit 8 and the drive circuit 14 must be separated, so that only the heat-sensitive drive battery 6 can be cooled by the cooler 22.

[0040] By the refrigerant valve 28 in the first switching position, i.e. as follows, that the refrigerant valve 28 is completely open with respect to the heat exchanger 30 and the bypass line 56 is open, the heat exchanger 30 is used as a heat source for the heat transfer circuit 44. Thus, heat is transferred from the air conditioning circuit 16 to the heat transfer circuit 44 and from there either by means of the heat exchanger 48 configured as a radiator to the free environment or by means of the refrigerant valve 18 and the battery circuit 8, for example, to the drive battery 6. Thereby, for example, a large condenser in the vehicle front of an electric vehicle can be dispensed with, since the transfer of waste heat from the air conditioning circuit 16 through the heat exchanger 30 is ensured. Thus, the selectively couplable heat transfer circuit 44 allows to simplify the air conditioning circuit 16 in addition to realizing various different operating modes of the thermal management system 2.

[0041] In the second switching position of the refrigerant valve 28, in which the flow-through of the refrigerant through the refrigerant valve 28 is restricted, a low-pressure region for the heat exchanger 30 is produced by the tapering in the refrigerant valve 28, so that the heat exchanger now works like a cooler 22. The heat exchanger 30 thus transfers heat from the heat transfer circuit 44 onto the air conditioning circuit 16. This is used, for example, to extract heat from the free environment, i.e. the ambient air, to temper the vehicle interior. To this end, the heat exchanger 30 transfers heat from the heat transfer circuit 44 to the air conditioning circuit 16 until the temperature in the heat transfer circuit 44 falls below the temperature of the free environment, i.e. the ambient temperature. Thereby, the now cooler coolant in the heat transfer circuit 44 is heated to the ambient temperature by the ambient air when passing through the heat exchanger 48 configured as a radiator. Subsequently, the heat exchanger 30 can again remove heat from the coolant in the heat transfer circuit 44, which is transferred to the vehicle interior via the liquefier 34 in the air conditioning circuit 16. Furthermore, in this operating mode of the thermal management system 2, the battery circuit 8 and the drive circuit 14 are connected in terms of coolant guidance, so that the waste heat of the drive battery 6, the electric drive 10 and the power electronics 12 can likewise be transferred to the vehicle interior by means of the cooler 22.

[0042] In consideration of all conceivable vehicle states, driving states and environmental conditions, a plurality of conceivable connections and disconnections, i.e. operating modes of the thermal management system 2, between the battery circuit 8, the drive circuit 14 and the air conditioning circuit 16 arise. Due to the inventive configuration of the thermal management system 2, thereby differing from usual thermal management systems for electric vehicles, the structural, manufacturing-technical and circuit-technical complexity, i.e. for example the number of coolant lines and refrigerant lines required and the number of coolant valves and refrigerant valves required, of the inventive thermal management system does not increase at all or to a lesser extent compared to less functional thermal management systems.

[0043] The air-conditioning circuit 16 can take up heat from the battery circuit 8 in order to heat the vehicle interior by means of the cooler 22. At very low outside temperatures, for example at ambient temperatures below -10°C, the PTC heater 20 represents the only heat source at the start of the electric vehicle. However, the efficiency of the heat transfer from the PTC heater 20 into the air-conditioning circuit 16 via the cooler 22 is limited by the extremely low coolant temperature. For this reason, at these ambient conditions, the coolant pump 23 in the battery circuit 8 is operated in a particularly slow delivery mode. As a result, only a small coolant quantity flows through the PTC heater 20 per unit of time, so that this coolant can be heated to a favorable high temperature in order to be able to extract heat from this coolant by means of the cooler 22 for tempering the vehicle interior effectively thereby.

[0044] Exemplarily, the use of the thermal management system 2 is illustrated below according to Figure 2 and Figure 3 by means of the operating modes of the thermal management system 2, wherein, in Figure 2 and Figure 3 the coolant lines of the coolant circuits 8, 14, 44, which are flowed through by coolant, or the refrigerant lines of the air-conditioning circuit 16, which is configured as a refrigerant circuit, are highlighted in bold.

[0045] It is possible, for example, to use the heat exchanger 30 and the cooler 22 to transfer the waste heat of the drive circuit 14, i.e. of the electric drive 10 and the power electronics 12, and of the battery circuit 8, i.e. of the drive battery 6.

[0046] In the operating mode according to Figure 2 only the cooler 22 is used to transfer the waste heat of the drive circuit 14, i.e. of the electric drive 10 and the power electronics 12, and of the battery circuit 8, i.e. of the drive battery 6.

[0047] In addition, a part of the waste heat of the drive circuit 14 can be output to the free environment by a proportional mixing of the individual coolant flows between the heat exchanger 48, which is configured as a radiator, and its bypass. This can be advantageous in order to ensure a constant heating power when heating the vehicle interior by means of the air-conditioning circuit 16 in the dynamic driving operation of the electric vehicle, for example in the case of a temporary excessive waste heat power of the battery circuit 8 and / or of the drive circuit 14. In this regard, reference is made to Figure 3 .

[0048] In addition to the aforementioned operating modes, further operating modes can also be realized by means of the thermal management system 2 according to Figures 1 to 3 .

[0049] Purely by way of example, the following further operating modes are mentioned here:

[0050] For example, the operating mode of the thermal management system 2 can provide for heating the vehicle interior space of the electric vehicle simultaneously with ambient heat from the free environment via the heat exchanger 30 and with waste heat from the drive battery 6, the electric drive 10 and the power electronics 12 via the cooler 22.

[0051] In a further example of a possible operating mode, the heat exchanger 30 is used to transfer waste heat from the drive circuit 14 to the free environment by means of the heat exchanger 48 and to the air conditioning circuit 16 by means of the heat exchanger 30, while the waste heat of the drive battery 6 is transferred to the air conditioning circuit 16 by means of the cooler 22. Thereby, an optimum temperature can be set for the battery circuit 8 and the drive circuit 14, respectively, i.e. the temperature level of the drive circuit 14 is higher compared to the battery circuit 8, if a joint use of the cooler 22 is possible.

[0052] Furthermore, in a further operating mode of the thermal management system 2, not only the waste heat power of the PTC heater 20 in the battery circuit 8, but also the loss heat of the compressor 38 in the air conditioning circuit 16, can be used to heat the vehicle interior space of the electric vehicle. For this purpose, the heat transfer circuit 44 and the battery circuit 8 are connected to one another by means of the coolant valve 18 in such a way that coolant is guided therebetween. The PTC heater 20 heats the coolant of the battery circuit 8, wherein, immediately thereafter, heat is again extracted from this coolant directly by means of the cooler 22. This heat is only partially output to the vehicle interior space of the electric vehicle by means of the liquefier 34. The remainder of this heat is again delivered to at least one of the coolant circuits 8, 14, 44 by means of the heat exchanger 30. Thus, the heat exchanger 30 forms a closed heat circuit with the cooler 22 by means of the connection of the air conditioning circuit 16. In a critical case, i.e. when no heat is conducted from the liquefier 34 to the vehicle interior space of the electric vehicle, the heat exchanger 30 transfers the same amount of heat to the coolant, which has previously been extracted from this coolant by means of the cooler 22. In order to maintain this heat circuit, the compressor 38 has to do hydraulic work.

[0053] The greater the amount of heat of the cycle, the greater this work and the loss heat of the compressor 38 that follows. The loss heat of the compressor 38 is conducted away by means of the refrigerant and thus additionally increases the heat transfer into the coolant. Thus, in this operating mode, the loss heat of the compressor 38 is added to the heat power of the PTC heater 20, so that a particularly high heating power can be used to quickly heat the drive battery 6 and / or the vehicle interior space of the electric vehicle.

[0054] As is clear from the above embodiments, by means of the control unit 4 operating the coolant valve 18 and the heat exchange device 24, the heat transfer connection between the battery circuit 8 and / or the drive circuit 14 on one side and the air conditioning circuit 16 on the other side is established or disconnected by means of the at least one heat exchange device 24. Furthermore, by means of the control unit 4 operating the coolant valve 18, which is also configured as another coolant valve, the heat transfer circuit 44 is connected or disconnected from the battery circuit 8 and / or the drive circuit 14 to guide the coolant. Furthermore, by means of the control unit 4 operating the refrigerant valves 26 and 28, which are also configured as bypass valves, the heat exchanger 30 arranged in the air conditioning circuit 16 may or may not have refrigerant flowing through it. A similar situation applies to the cooler 22 and the valve 40 provided to it. The operation of the coolant valve 18 and / or the heat exchange device 24 and / or the refrigerant valves 26, 28 and / or the coolant pumps 13, 23, 46 operable by means of the control unit 4, in order to deliver the coolant in one of the coolant circuits 8, 14, 44, is performed according to at least one environmental condition of the electric vehicle's vehicle state and / or the electric vehicle's driving state and / or the free environment.

[0055] exist Figure 4 and Figure 5 The image exemplarily illustrates two aspects of the thermal management system according to the present invention. Figures 1 to 3 The first embodiment is an alternative implementation. Of course, other structural, manufacturing, and circuitry modifications are also conceivable.

[0056] According to Figure 4 In a second embodiment of the thermal management system according to the present invention, a heat exchange device 24 consisting of a heat exchanger 30 and refrigerant valves 26, 28 is connected to a heat exchanger according to the present invention. Figures 1 to 3 The first embodiment is modified in comparison. Instead of two 3 / 2 directional control valves, one of the 3 / 2 directional control valves, namely refrigerant valve 26, is replaced here by a one-way valve 58 and a check valve 60. In other respects, the second embodiment corresponds to the first embodiment. Accordingly, reference is made here to the above explanation regarding the first embodiment.

[0057] according to Figure 5 The third embodiment is an implementation of the thermal management system according to the invention, wherein the functional scope and thus complexity of the thermal management system are reduced compared to the two first-mentioned embodiments. A particular advantage of this third embodiment is that the coolant valve can be simplified and thus constructed at a lower cost. The air conditioning circuit 16 corresponds here to the first embodiment; however, the heat transfer circuit 44 is modified compared to the first and second embodiments.

[0058] On the basis of the configuration according to the application for a thermal management system for an electric vehicle and for a method for operating the thermal management system, according to the current embodiment, an effective temperature control of the electric vehicle, i.e. of the drive battery 6, the electric drive 10 and the power electronics 12 for the electric drive 10 and of the vehicle interior of the electric vehicle, is able to be achieved while simplifying the structure of the thermal management system 2. Accordingly, for example, an air-refrigerant-condenser in the vehicle front of the electric vehicle is not necessary. Furthermore, the thermal management system 2 is able to be realized with less design and production engineering outlay and with less costs. The system structure according to the application is generally significantly simplified compared to the conventional technical solutions.

[0059] The application is not limited to the current embodiment. For example, the application can also be advantageously applied in other electric vehicles. For this purpose, reference is also made to the explanations in the introductory part of the description.

[0060] In particular, the application is not limited to the structural, production engineering and circuit-technical configuration of the three embodiments.

Claims

1. A thermal management system (2) for an electric vehicle, the thermal management system comprising: The control unit (4), a battery circuit (8) in heat transfer connection with a drive battery (6) of the electric vehicle, a drive circuit (14) in heat transfer connection with an electric drive (10) of the electric vehicle and / or with power electronics (12) for the electric drive (10), and an air conditioning circuit (16) in heat transfer connection with a vehicle interior of the electric vehicle, wherein, on the one hand, the battery circuit (8) and the drive circuit (14) can each be operated with a coolant and can be connected or disconnected to one another by means of at least one controllable coolant valve (18), and, on the other hand, the air conditioning circuit (16) can be operated with a refrigerant which is different from the coolant, characterized in that, by means of at least one heat exchange device (24) of the thermal management system (2), a heat transfer connection between, on the one hand, the battery circuit (8) and / or the drive circuit (14) and, on the other hand, the air conditioning circuit (16) can be established or can be interrupted in dependence on a control of the coolant valve (18) and a control of the heat exchange device (24) by means of the control unit (4), wherein the heat exchange device (24) has at least one refrigerant valve (26, 28) and at least one heat exchanger (30), wherein the heat exchanger (30) can be flowed through or can not be flowed through by the refrigerant in dependence on a control of the refrigerant valve (26, 28) by means of the control unit (4), and wherein, in the air conditioning circuit (16), in addition to the heat exchange device (24), a cooler (22), an evaporator (32), a liquefier (34), an accumulator (36), a compressor (38) and a valve (40) are arranged, such that the cooler (22) is arranged not only in the battery circuit (8) but also in the air conditioning circuit (16) and, similar to the heat exchange device (24), by means of the cooler (22) a heat transfer connection between, on the one hand, the air conditioning circuit (16) and, on the other hand, the battery circuit (8) can be established or can be interrupted in dependence on a control of the coolant valve (18) and a control of the valve (40) by means of the control unit (4), so that the cooler (22) can be flowed through or can not be flowed through by the refrigerant in dependence on a control of the valve (40) by means of the control unit (4), wherein the thermal management system (2) is configured in such a way that not only the heat exchanger (30) but also the cooler (22) can be used simultaneously for transferring waste heat of the drive circuit (14) and waste heat of the battery circuit (8) for heating the vehicle interior of the electric vehicle.

2. The thermal management system (2) according to claim 1, characterized in that The thermal management system (2) additionally has a heat transfer circuit (44) which is operated with a coolant, wherein at least one of the at least one heat exchanger (30) is arranged in the heat transfer circuit (44) in such a way that, by means of the heat exchanger (30), a heat transfer connection between the coolant flowing in the heat transfer circuit (44) and the refrigerant can be established or can be interrupted, and the heat transfer circuit (44) can be connected or disconnected to the battery circuit (8) and / or to the drive circuit (14) by means of at least one further coolant valve which can be controlled by means of the control unit (4).

3. The thermal management system (2) according to claim 2, characterized in that The heat transfer circuit (44) is configured in such a way that a heat transfer connection between the coolant flowing in the heat transfer circuit (44) and the free environment can be established or interrupted by means of the heat transfer circuit (44).

4. The thermal management system (2) according to claim 3, characterized in that The thermal management system (2) is configured in such a way that ambient heat from the free environment via the heat exchanger (30) and waste heat from the drive battery (6), the electric drive (10) and the power electronics (12) via the cooler (22) can be used simultaneously for heating a vehicle interior space of the electric vehicle.

5. The thermal management system (2) according to any one of claims 2 to 4, characterized in that The heat exchanger device (24) and / or the coolant valve (18) and / or the further coolant valve (18) are configured in coordination with one another in such a way that, on the one hand, the battery circuit (8) and / or the drive circuit (14) can be heated and / or cooled by means of, on the other hand, the heat exchanger device (24) and the air conditioning circuit (16) and / or the heat transfer circuit (44), and / or, on the one hand, the air conditioning circuit (16) can be heated and / or cooled by means of, on the other hand, the heat exchanger device (24) and the battery circuit (8) and / or the drive circuit (14) and / or the heat transfer circuit (44).

6. The thermal management system (2) according to any one of claims 2 to 4, characterized in that The thermal management system (2) has at least one bypass device (54) in the battery circuit and / or the drive circuit and / or the air conditioning circuit (16) and / or the heat transfer circuit, which has at least one bypass line (56) and at least one controllable bypass valve, wherein, by means of the respective bypass device (54), a heat exchanger (30) arranged in the respective circuit can be bypassed or cannot be bypassed depending on the actuation of the bypass valve by means of the control (4).

7. The thermal management system (2) according to any one of claims 1 to 4, characterized in that The waste heat of the drive circuit (14) comprises the waste heat of the electric drive and the power electronics, and the waste heat of the battery circuit (8) comprises the waste heat of the drive battery.

8. The thermal management system (2) of claim 2, characterized in that, The coolant valve (18) is configured at the same time as the further coolant valve.

9. The thermal management system (2) of claim 3, characterized in that, The heat transfer to the free environment is possible by means of at least one heat exchanger arranged in the heat transfer circuit (44).

10. A method for operating a thermal management system (2) for an electrically driven vehicle according to any one of claims 1 to 9, wherein, Depending on the actuation of the coolant valve (18) and the actuation of the heat exchanger device (24) by means of the control (4), a heat transfer connection between, on the one hand, the battery circuit (8) and / or the drive circuit (14) and, on the other hand, the air conditioning circuit (16) is established or interrupted by means of the at least one heat exchanger device (24) in such a way that the heat exchanger (30) is bypassed or not bypassed by refrigerant depending on the actuation of the refrigerant valves (26, 28) by means of the control (4), and, similar to the heat exchanger device (24), a heat transfer connection between, on the one hand, the air conditioning circuit (16) and, on the other hand, the battery circuit (8) is established or interrupted by means of the cooler (22) depending on the actuation of the coolant valve (18) and the actuation of the valve (40) by means of the control (4) in such a way that the cooler (22) is bypassed or not bypassed by refrigerant depending on the actuation of the valve (40) by means of the control (4), In which both the heat exchanger (30) and the cooler (22) are used simultaneously for transferring waste heat of the drive circuit (14) and of the battery circuit (8) for heating the vehicle interior of the electric vehicle.

11. The method of claim 10, wherein, Both the ambient heat from the free environment via the heat exchanger (30) and the waste heat from the drive battery (6), the electric drive (10) and the power electronics (12) via the cooler (22) are used simultaneously for heating the vehicle interior of the electric vehicle.

12. The method of claim 10, wherein, By means of the actuation of the further coolant valve (18) by the control unit (4), the heat transfer circuit (44) is connected or disconnected with the battery circuit (8) and / or the drive circuit (14) conductively.

13. The method according to any one of claims 10 to 12, characterized in that, Depending on the actuation of the bypass valve, the heat exchanger (30) arranged in the respective circuit with the bypass device (54) is bypassed or not bypassed.

14. The method according to any one of claims 10 to 12, characterized in that, In one of the coolant circuits (8, 14, 44), for conveying coolant in the coolant circuit (8, 14, 44), depending on the vehicle state of the electric vehicle and / or the driving state of the electric vehicle and / or at least one environmental condition of the free environment, the coolant valve (18) and / or the heat exchanger device (24) and / or the further coolant valve (18) and / or the bypass valve and / or the pump (13, 23, 46) which can be actuated by means of the control unit (4) are actuated.

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