Coolant system for an electric vehicle, and cooling system for an electric vehicle, comprising a coolant system and a refrigerant circuit

Abstract

The invention relates to a coolant system (4) for an electric vehicle, comprising a plurality of components (12, 14, 16, 18, 20, 22, 30, 34) through which the coolant can flow, the components (12, 14, 16, 18, 20, 22, 30, 34) being interconnectable, by means of at least one valve (26) and coolant lines (32), so as to conduct coolant, the at least one valve (26) being designed as merely a single multi-way valve, and a component bypass line (24) of the coolant system (4) being arranged with respect to at least one of the components (22) through which the coolant can flow such that this component (22) is connectable, by means of the component bypass line (24), to the multi-way valve (26) so as to conduct coolant in such a way that, in a first switching state of the multi-way valve (26), the coolant can flow both through the component bypass line (24) in a first flow direction and through this component (22) and, in a second switching state of the multi-way valve (26), the coolant can flow through the component bypass line (24) in a second flow direction opposite the first flow direction.

Description

[0001] Coolant system for an electric vehicle and cooling system for an electric vehicle with a coolant system and a refrigerant circuit

[0002] Description

[0003] The present invention relates to a coolant system for an electric vehicle of the type mentioned in the preamble of claim 1 and a cooling system for an electric vehicle with a coolant system and a refrigerant circuit of the type mentioned in the preamble of claim 11.

[0004] Such coolant systems for electric vehicles and cooling systems for electric vehicles are already known from the state of the art in numerous design variants.

[0005] This is where the present invention comes in.

[0006] The present invention is based on the object of improving a coolant system for an electric vehicle and a cooling system for an electric vehicle with a coolant system and a refrigerant circuit.

[0007] This object is achieved by a coolant system for electric vehicles with the features of claim 1, which is characterized in that the at least one valve is designed as only a single multi-way valve and a component bypass line of the coolant system is arranged for at least one of the components through which the coolant can flow, such that this component can be connected to the multi-way valve in a coolant-conducting manner by means of the component bypass line, such that in a first switching state of the multi-way valve, the coolant can flow through both the component bypass line in a first flow direction and this component, and in a second switching state of the multi-way valve, the coolant can flow through the component bypass line in a second flow direction opposite to the first flow direction in the bypass to this component.The aforementioned component can be designed as any sensible and suitable component of the coolant system according to the invention through which the coolant can flow. When a component is bypassed by means of the component bypass line, the coolant is guided to this component via the bypass. Furthermore, this problem is solved by a cooling system for electric vehicles with the features of claim 11. The subclaims relate to advantageous developments of the invention.

[0008] A significant advantage of the invention lies in particular in the fact that a coolant system for an electric vehicle and a cooling system for an electric vehicle with a coolant system and a refrigerant circuit are improved. Due to the invention, functionally complex coolant systems and cooling systems for electric vehicles can be implemented in a manner that is simpler in terms of design and production technology. By means of the inventive combination with the multi-way valve and the component bypass line, it is possible to use the component bypass line for different operating states of the inventive coolant system, since the component bypass line can be flowed through with the coolant in both fundamentally possible flow directions. Accordingly, the number of coolant lines and valves is significantly reduced.At the same time, the invention increases the efficiency of such coolant systems and cooling systems, as the aforementioned systems enable greater functional complexity with significantly fewer components compared to the prior art. Accordingly, a multitude of operating states, i.e., system operating modes, can be realized with a simply constructed system with few components and coolant lines.

[0009] In principle, the cooling system for an electric vehicle according to the invention and the coolant system for an electric vehicle according to the invention can each be freely selected in terms of type, mode of operation, material, and dimensioning within wide, suitable limits. Furthermore, the invention is not limited to application in purely electric vehicles. For example, the invention can also be advantageously used in so-called hybrid vehicles. An advantageous development of the coolant system according to the invention provides that the plurality of components comprises at least a subset of the following components of a cooling system: coolant pump, battery, chiller, coolant heater, powertrain with an electric motor and power electronics for the electric motor, cooling air radiator for heat exchange with the outside environment, and condenser. The aforementioned components can also be installed in a plurality of the respective components in the coolant system according to the invention.This specifies essential components for a coolant system for the coolant system according to the invention.

[0010] A particularly advantageous development of the aforementioned embodiment of the coolant system according to the invention provides that the plurality of components has a chiller, wherein the component bypass line is designed as a chiller bypass line and the chiller is designed as the component around which flow can pass in the bypass by means of the component bypass line in the second switching state of the multi-way valve. Preferably, a component outlet designed as a chiller outlet can be connected to the multi-way valve in a coolant-conducting manner by means of the component bypass line. In this way, the component and the component bypass line are implemented in a particularly suitable manner. By means of the chiller, in particular the battery can be cooled to a temperature range required for its function, despite adverse ambient and / or operating conditions of the electric vehicle.However, due to the invention, the chiller can also be used additionally or alternatively for other cooling tasks, for example, for cooling the power electronics and / or the electric motor. The waste heat generated during any cooling process using the cooling system according to the invention with the coolant system according to the invention, including the waste heat from the chiller, can, depending on the switching state of the multi-way valve, be usefully used to heat other areas of the vehicle, for example a passenger compartment, or to heat other components of the coolant system. Of course, dissipation of this waste heat to the outside environment, for example, by means of a cooling air radiator of the coolant system, is also conceivable.

[0011] Another advantageous development of the coolant system according to the invention provides that the plurality of components is distributed across at least two coolant circuits of the coolant system, wherein the at least two coolant circuits can be connected to one another in a coolant-conducting manner by means of the multi-way valve, preferably that on the one hand a first coolant pump and / or the battery and / or the chiller and / or the coolant heater are arranged in a first coolant circuit and / or on the other hand a second coolant pump and / or the powertrain and / or the cooling air radiator and / or the condenser are arranged in a second coolant circuit. In this way, it is possible, on the one hand, to operate the at least two coolant circuits separately or, on the other hand, to operate them in a coolant-conducting connection with one another. The preferred embodiment of this development specifies a particularly advantageous refinement of this development.Of course, the present development also includes embodiments of the invention with more than two coolant circuits.

[0012] An advantageous development of the aforementioned development of the coolant system according to the invention provides that the first coolant circuit is designed as a battery subcircuit, with the chiller, the first coolant pump, and the battery arranged downstream of the first coolant pump in the flow direction with respect to the flow of coolant through the first coolant pump, and the second coolant circuit is designed as a drive train subcircuit, with the second coolant pump and the powertrain and cooling air radiator arranged downstream of the second coolant pump in the flow direction with respect to the flow of coolant through the second coolant pump for cooling the coolant flowing in the drive train subcircuit with ambient air. As a result, the first and second coolant circuits are implemented in a very advantageous manner.A particularly advantageous development of the latter embodiment of the coolant system according to the invention provides that the multi-way valve is designed such that the drive train subcircuit can be continuously flowed through with coolant in all possible switching states of the multi-way valve and when the multi-way valve is transferred from one of these switching states to another. This ensures that the drive train subcircuit, and thus the power electronics and the electric motor, are reliably cooled to the temperature required for their proper functioning under all ambient and operating conditions of the electric vehicle.

[0013] An advantageous development of the coolant system according to the invention according to claim 5 or 6, with reference back to claim 3, provides that one end of the chiller bypass line, with respect to a flow of coolant through the chiller and the first coolant pump, is arranged in a coolant-conducting manner in the flow direction downstream of the chiller outlet and upstream of an inlet of the first coolant pump. In this way, it is possible, on the one hand, to use the chiller without essentially simultaneously cooling the battery, for example for other cooling tasks. This is possible when the first coolant pump is switched off. When the first coolant pump is switched on, this development also makes it possible, for example, to deviate from the case in which the coolant flows through the battery using the chiller bypassing the chiller by means of the chiller bypass line.

[0014] An advantageous development of the coolant system according to the invention according to one of claims 5 to 7 provides that in the battery subcircuit, with respect to a flow of coolant through the battery, a check valve is additionally arranged downstream of the battery in the flow direction such that the check valve only allows the coolant to flow from the battery in the direction of the multi-way valve. This makes it possible, for example, to design the multi-way valve more simply, since unwanted flow through the battery from the direction of the multi-way valve is effectively prevented by the check valve. Otherwise, i.e. if no such check valve is provided, this unwanted flow of coolant through the battery can be prevented by means of the multi-way valve, i.e. in a switching state of the multi-way valve.

[0015] An advantageous development of the coolant system according to the invention according to one of claims 5 to 8 provides that the battery sub-circuit additionally has a coolant heater for heating the battery as needed, wherein the coolant heater is arranged downstream of the multi-way valve and upstream of the chiller in the flow direction with respect to the flow of coolant through the chiller. Preferably, the chiller and the coolant heater are arranged in a common coolant line of the battery sub-circuit, particularly preferably, the coolant heater is designed as an electric heater. In this way, the battery can also be heated in the presence of extreme ambient cold or the like. The preferred embodiment of this development also has the further advantage that not only the chiller, but also the coolant heater can be bypassed by means of the chiller bypass line in a manner that is simple in terms of design and manufacturing technology.When bypassing at least one component, for example, the chiller and the coolant heater, the coolant is routed to this component or these components via a bypass. Furthermore, the coolant heater can be implemented particularly advantageously according to the particularly preferred embodiment of this development; this applies in particular if the vehicle is an electric vehicle.

[0016] An advantageous development of the coolant system according to the invention according to one of claims 4 to 9 provides that the coolant system is designed such that, depending on the switching state of the multi-way valve, the following coolant-conducting connections can be realized at least in a subset, preferably all, solely by means of the multi-way valve: a) coolant-conducting connection of the chiller to the battery, b) coolant-conducting connection of the chiller to the power electronics and the electric motor, c) coolant-conducting connection of the chiller to the cooling air radiator, the power electronics and the electric motor, d) coolant-conducting connection of the chiller to the battery, the power electronics and the electric motor, e) coolant-conducting connection of the chiller to the battery, the cooling air radiator, the power electronics and the electric motor.This makes the coolant system according to the invention particularly flexible and thus suitable for use in an electric vehicle, even for temperature control tasks that are inherently very demanding in terms of circuitry. This applies in particular to the preferred embodiment of this further development.

[0017] The advantages associated with the coolant system according to the invention can also be used for the cooling system according to the invention, comprising a coolant system and a refrigerant circuit for air conditioning a passenger compartment of the electric vehicle.

[0018] An advantageous development of the cooling system according to the invention provides that the refrigerant circuit is designed for air conditioning a passenger compartment of the electric vehicle and / or for controlling the temperature of a coolant flowing in the coolant circuit. This allows the refrigerant circuit to be used in a particularly advantageous manner.

[0019] An advantageous development of the cooling system according to the invention, referring back to claim 2, provides that the cooling system is designed such that, if necessary, a heat transfer connection can be established between the coolant system on one side and the refrigerant circuit on the other side by means of the chiller. In this way, in addition to controlling the temperature of the refrigerant circuit, i.e., a refrigerant flowing in the refrigerant circuit, the coolant also enables the temperature of the coolant system in a very simple manner in terms of design and manufacturing technology. The chiller is thus a component of both the coolant system and the refrigerant circuit.

[0020] Furthermore, a further advantageous development of the cooling system according to the invention, with reference back to claim 2, provides that the cooling system is designed such that, if necessary, a heat transfer connection can be established between the coolant system on the one side and the refrigerant circuit on the other side by means of the condenser, preferably that the condenser is arranged in the drive train sub-circuit in a coolant-conducting manner. As a result, for example, a component present in a conventional refrigerant circuit for an electric vehicle, namely the condenser, can be used both for the operation of the refrigerant circuit and for heat transfer between the coolant system on the one side and the refrigerant circuit on the other side. Accordingly, advantages arise here that are comparable to those of the aforementioned development of the cooling system according to the invention.Combining the two aforementioned developments of the cooling system according to the invention further enables even more energy to be exchanged between the coolant system and the refrigerant circuit. Furthermore, the flexibility of the cooling system according to the invention is further increased.

[0021] The invention is explained in more detail below using the attached, roughly schematic drawing. It shows:

[0022] Fig. 1 shows an embodiment of the cooling system according to the invention with the coolant system according to the invention in a process flow diagram,

[0023] Fig. 2 shows the embodiment in an analogous representation to Fig. 1 , in a first operating state of the cooling system,

[0024] Fig. 3 shows the embodiment in an analogous representation to Fig. 1, in a second operating state of the cooling system,

[0025] Fig. 4 shows the embodiment in an analogous representation to Fig. 1, in a third operating state of the cooling system,

[0026] Fig. 5 shows the embodiment in an analogous representation to Fig. 1, in a fourth operating state of the cooling system,

[0027] Fig. 6 shows the embodiment in a representation analogous to Fig. 1 , in a fifth operating state of the cooling system, Fig. 7 shows the embodiment in a representation analogous to Fig. 1 , in a sixth operating state of the cooling system and

[0028] Fig. 8 shows the embodiment in an analogous representation to Fig. 1, in a seventh operating state of the cooling system.

[0029] In Figures 1 to 8, an embodiment of the cooling system according to the invention for an electric vehicle with the coolant system according to the invention for an electric vehicle is shown purely by way of example.

[0030] The electric vehicle is designed here as a pure electric vehicle and is not shown in more detail.

[0031] The cooling system 2 for the electric vehicle comprises, on the one hand, a coolant system 4 with a first coolant circuit 6 designed as a battery subcircuit and a second coolant circuit 8 designed as a drive train subcircuit, and, on the other hand, a refrigerant circuit 10 for air conditioning a passenger compartment (not shown) of the electric vehicle and for controlling the temperature of the coolant system 4.

[0032] The coolant system 4 for circulating a liquid coolant comprises, on the one hand, the battery subcircuit 6 with the following components of the coolant system 4, namely a first coolant pump 12 and a battery 14 arranged downstream of the first coolant pump 12 in the flow direction with respect to the flow of the coolant through the first coolant pump 12, and, on the other hand, the drive train subcircuit 8 with the following components of the coolant system 4, namely a second coolant pump 16 and a powertrain 18 arranged downstream of the second coolant pump 16 in the flow direction with respect to the flow of the coolant through the second coolant pump 16, with power electronics and an electric motor, and cooling air radiator 20 for cooling the coolant flowing in the drive train subcircuit 8 with ambient air,wherein the battery subcircuit 6 and the drive train subcircuit 8 are connectable to one another in a coolant-conducting manner by means of at least one valve and coolant lines. The coolant is not shown in Figs. 1 to 8. Furthermore, the coolant system 4 has at least one component 22 designed as a chiller through which the coolant can flow, and a component bypass line 24 designed as a chiller bypass line. Furthermore, the at least one valve is designed as a single multi-way valve 26, wherein a component outlet of the chiller 22 designed as a chiller outlet is connectable to the multi-way valve 26 in a coolant-conducting manner by means of the chiller bypass line 24,that in a first switching state of the multi-way valve 26, the coolant can flow through both the chiller bypass line 24 in a first flow direction and the chiller 22, and in a second switching state of the multi-way valve 26, the coolant can flow through the chiller bypass line 24 in a second flow direction opposite to the first flow direction in the bypass to the chiller 22. See, for example, Figs. 5 and 7, wherein Fig. 5 shows the first switching state of the multi-way valve 26 and Fig. 7 shows the second switching state of the multi-way valve 26. The multi-way valve 26 can be designed and manufactured in a variety of embodiments suitable for the invention.

[0033] Thus, the component 22 with the component outlet is designed as a chiller arranged in the battery sub-circuit 6 with a chiller outlet, and the component bypass line 24 is designed as a chiller bypass line, wherein in the second switching state of the multi-way valve 26, the coolant can flow through the battery 14 in the bypass to the chiller 22 by means of the chiller bypass line 24. One end of the chiller bypass line 24 is arranged here, with respect to a flow through the chiller 22 and the first coolant pump 12 with the coolant, in a coolant-conducting manner downstream of the chiller outlet and upstream of an inlet of the first coolant pump 12, wherein the battery 14 is arranged downstream of the first coolant pump 12 in the flow direction with respect to a flow through the first coolant pump 12 with the coolant. Furthermore, in the battery sub-circuit 6 according to Fig.1 to 7, based on a flow through the battery 14 with the coolant, in the flow direction after the battery 14, a check valve 28 is additionally arranged such that the check valve 28 only allows a flow of the coolant from the battery 14 in the direction of the multi-way valve 26.

[0034] In contrast, variants of the coolant system according to the invention, for example, the coolant system 4, are also conceivable in which the aforementioned use of a check valve is dispensable. See, for example, Fig. 8, in which such a variant is shown purely as an example. In this variant according to Fig. 8, i.e., when no check valve is provided, the aforementioned undesired flow of coolant through the battery 14 is prevented by means of the multi-way valve 26, i.e., in a switching state of the multi-way valve 26.

[0035] In the present exemplary embodiment, the multi-way valve 26 is designed such that the drive train sub-circuit 8 can be continuously flowed through with the coolant in all possible switching states of the multi-way valve 26 and when the multi-way valve 26 is transferred from one of these switching states to another of these switching states.

[0036] In the present exemplary embodiment, the battery subcircuit 6 additionally has a coolant heater 30 designed as an electric heater for heating the battery 14 as needed, wherein the coolant heater 30 is arranged downstream of the multi-way valve 26 and upstream of the chiller 22 in the flow direction, with respect to a flow through the chiller 22 with the coolant, and wherein the chiller 22 and the coolant heater 30 are arranged in a common coolant line 32 of the battery subcircuit 6.

[0037] As can also be seen from Figs. 1 to 8, on the one hand, a heat transfer connection can be established between the coolant system 4 on the one side and the refrigerant circuit 10 on the other side by means of the chiller 22. On the other hand, the refrigerant circuit 10 here has a condenser 34, wherein the cooling system 2 is designed such that, by means of the condenser 34, alternatively or in addition to the chiller 22, a heat transfer connection can be established between the coolant system 4 on the one side and the refrigerant circuit 10 on the other side. For this purpose, the condenser 34 is arranged in the drive train subcircuit 8 in a coolant-conducting manner.

[0038] In addition to the chiller 22 and the condenser 34, the refrigerant circuit 10 also has the following additional components: a compressor 36, a further condenser 38, a dryer 40, an evaporator 42, as well as two expansion valves 44, 46 and a switching valve 48. The aforementioned components of the refrigerant circuit 10 are interconnected here as shown in Figs. 1 to 8 and interact with one another in the usual way as a heat pump for the purpose of air conditioning the passenger compartment of the electric vehicle.

[0039] The coolant system 4 is designed here such that, depending on the switching state of the multi-way valve 26, all of the following coolant-conducting connections can be realized solely by means of the multi-way valve 26: a) coolant-conducting connection of the chiller 22 to the battery 14, b) coolant-conducting connection of the chiller 22 to the powertrain 18, i.e., the power electronics and the electric motor, c) coolant-conducting connection of the chiller 22 to the cooling air radiator 20 and the powertrain 18, i.e., the power electronics and the electric motor, d) coolant-conducting connection of the chiller 22 to the battery 14 and the powertrain 18, i.e., the power electronics and the electric motor, e) coolant-conducting connection of the chiller 22 to the battery 14, the cooling air radiator 20, and the powertrain 18, i.e., the power electronics and the electric motor. This will be explained in more detail with reference to Figs. 2 to 8.

[0040] In the following, the functioning of the cooling system according to the invention with the coolant system according to the invention according to the present embodiment is explained in more detail with reference to Figs. 1 to 8.

[0041] Depending on the operating state of the cooling system 2, i.e. the battery sub-circuit 6, the powertrain sub-circuit 8 and the refrigerant circuit 10, as well as taking into account the driving situation and the ambient temperature, the aforementioned circuits can represent heat sources or heat sinks of the cooling system 2.

[0042] The efficiency of the overall system, i.e., cooling system 2, can be improved by connecting or disconnecting the individual aforementioned coolant circuits as needed. According to the invention, this is achieved in a particularly simple manner in terms of design and manufacturing technology, while simultaneously ensuring high efficiency of the overall system.

[0043] For example, while driving, the battery 14 can be efficiently warmed up in a cold state using the waste heat from the powertrain 18, namely the power electronics and the electric motor. For this purpose, the battery subcircuit 6 must be connected to the power electronics and the electric motor, i.e., the powertrain 18, in a coolant-conducting manner. At very high ambient temperatures, however, it is imperative that the battery subcircuit 6 and the drivetrain subcircuit 8 are separated so that only the heat-sensitive battery 14 can be cooled by the chiller 22. Heating the interior, i.e., the passenger compartment, in particular, represents a major challenge, since in an electric vehicle, the powertrain 18 typically generates too little waste heat compared to a vehicle with a combustion engine. For this reason, the chiller 22 is used to supply heat from all available heat sources of the cooling system 2 to the refrigerant circuit 10, i.e., the heat pump.Accordingly, the waste heat from the battery 14, the powertrain 18, or from ambient air, which is transferred to the coolant by means of the cooling air radiator 20, must be supplied to the chiller 22, depending on availability, by creating a coolant-conducting connection between these components.

[0044] In order to optimally combine the waste heat from the battery 14 and / or the powertrain 18 and / or from the ambient air, taking into account all conceivable driving states and environmental conditions, a plurality of coolant-conducting connections between the battery 14, the powertrain 18, the cooling air radiator 20, and the chiller 22 is required. This is made possible by the invention while simultaneously keeping the structural complexity of the cooling system 2 low, i.e., while simultaneously requiring a small number of coolant lines and valves. Fig. 1 shows the cooling system 2, with which the above-mentioned combinations a) to e) for utilizing various heat sources of the cooling system 2 are possible.

[0045] Since the coolant heater 30 is arranged upstream of the chiller 22 in the flow direction, relative to the coolant flowing through the coolant heater 30, its heat can be transferred to the refrigerant circuit 10 at any time, in addition to the waste heat, via the chiller 22. Furthermore, the chiller bypass line 24 provides the option of bypassing the chiller 22, so that the powertrain 18 and battery 14 can be directly connected in a coolant-conducting manner. This can be used, for example, to operate the refrigerant circuit 10 in a so-called triangular process. The high flexibility with regard to waste heat utilization as well as the other required operating modes, i.e., operating states of the cooling system 2, would otherwise require at least three standard coolant valves, which would increase system costs and the overall pressure loss and thus simultaneously reduce system efficiency.According to the invention, as realized in the embodiment, the structural system complexity is greatly reduced and the system efficiency is significantly improved.

[0046] The inventive combination of the components of the cooling system 2, in particular the multi-way valve 26, the chiller 22 and the chiller bypass line 24, enables the following six operating modes of the cooling system 2.

[0047] In a first operating state of the cooling system 2 and a corresponding switching state of the multi-way valve 26, the battery 14 is cooled separately via the chiller 22, while the powertrain 18 is connected to the cooling air radiator 20 in a parallel coolant circuit. See Fig. 2. The coolant lines of the coolant system 4 through which coolant flows or the refrigerant lines of the refrigerant circuit 10 through which refrigerant flows are shown in bold in Figs. 1 to 8. This first operating state of the cooling system 2 corresponds to the above-mentioned coolant-conducting connection a.

[0048] In a second operating state of the cooling system 2, which is alternative to the aforementioned waste heat utilization case and has a corresponding switching state of the multi-way valve 26, the battery 14 is heated separately via the coolant heater 30, while the powertrain 18 is connected to the multi-way valve 26 in a parallel coolant circuit, bypassing the cooling air radiator 20. See Fig. 3. This second operating state of the cooling system 2 also corresponds to the above-mentioned coolant-conducting connection a.

[0049] In a third operating state of the cooling system 2 with a corresponding switching state of the multi-way valve 26, the battery sub-circuit 6 and the drive train sub-circuit 8 are implemented in parallel, bypassing the cooling air radiator 20, but are coupled via the chiller 22. The chiller 22 acts as a mixing section, i.e., the coolant flows of the two aforementioned coolant circuits overlap and mix in the chiller 22. See Fig. 4. The coolant flow in the battery sub-circuit 6 is shown in dotted lines for easier differentiation. Accordingly, the third operating state of the cooling system 2 corresponds both to the aforementioned coolant-conducting connection b and, at the same time, to the aforementioned coolant-conducting connection d. If both coolant pumps 12, 16 are in operation, this third operating mode of the cooling system 2 corresponds to the coolant-conducting connection d.If the first coolant pump 12 is switched off, this results in the coolant-conducting connection b.

[0050] In a fourth operating state of the cooling system 2 with a corresponding switching state of the multi-way valve 26, the battery sub-circuit 6 and the drive train sub-circuit 8 are implemented in parallel, but are again coupled via the chiller 22. This again functions as a mixing section, i.e. the coolant flows of the two aforementioned circuits overlap and mix in the chiller 22. In the drive train sub-circuit 8, the corresponding coolant flow is then passed through the cooling air radiator 20. See Fig. 5. The coolant flow in the battery sub-circuit 6 is again shown in dotted lines for clarity. If both coolant pumps 12, 16 are in operation, this operating mode corresponds to the aforementioned coolant-conducting connection e. If the first coolant pump 12 is switched off, this results in the aforementioned coolant-conducting connection c. Based on the present operating state according to Fig.5, reference is made here, by way of example, to the flow through the chiller bypass line 24 in the first flow direction, i.e., from the chiller 24 toward the multi-way valve 26. See also the relevant comments on the sixth embodiment shown in Fig. 7.

[0051] In a fifth operating state of the cooling system 2 with a corresponding switching state of the multi-way valve 26, the battery subcircuit 6 and the drive train subcircuit 8 form a common coolant circuit with the chiller 22. The cooling air radiator 20 is not connected in a coolant-conducting manner. See Fig. 6. This fifth operating state corresponds to the aforementioned coolant-conducting connection d.

[0052] In a sixth operating state of the cooling system 2 with a corresponding switching state of the multi-way valve 26, the battery subcircuit 6 and the drive train subcircuit 8 form a common coolant circuit, with the coolant flow bypassing the chiller 22 via the chiller bypass line 24. The cooling air radiator 20 is also not connected in a coolant-conducting manner here. See Fig. 7. Based on the present operating state according to Fig. 7, reference is made here, by way of example, to the flow through the chiller bypass line 24 in the second flow direction, i.e., from the multi-way valve 26 toward the battery 14. See also the relevant explanations for the fourth exemplary embodiment according to Fig. 5.

[0053] The check valve 28 in the battery subcircuit 6 is required exclusively for the fourth operating state of the cooling system 2 according to Fig. 5 with the first coolant pump 12 switched off, which corresponds to the aforementioned coolant-conducting connection c, since otherwise an unwanted flow through the battery 14 from the multi-way valve 26 in the direction of the battery 14 would be possible. According to the variant of the cooling system 2 already explained above, the seventh operating state of the cooling system 2, which is an alternative to the fourth operating state, provides that the coolant return from the multi-way valve 26 into the battery 14 is prevented by means of the multi-way valve 26, i.e. by means of a switching state of the multi-way valve 26 corresponding to the seventh operating state of the cooling system 2. See Fig. 8. In the latter variant of the cooling system 2 according to Fig. 8, the check valve can thus be completely omitted.If, in other embodiments of the cooling system according to the invention or the coolant system according to the invention, an operating state analogous to the aforementioned fourth operating state is not required, the aforementioned check valve can be omitted without replacement. Accordingly, an adjustment of the multi-way valve analogous to the seventh operating state would then also not be necessary.

[0054] Due to the invention, the functionally complex cooling system 2 for an electric vehicle with the coolant system 4 can be implemented in a structurally and technically simple manner. By means of the inventive combination with the multi-way valve 26 and the component bypass line 24, it is possible to use the component bypass line 24 for different operating states of the coolant system 4, since the component bypass line 24 can be flowed through with the coolant in both fundamentally possible flow directions. Accordingly, the number of coolant lines and valves is significantly reduced. At the same time, efficiency is increased by means of the cooling system 2, since the coolant system 4 of the cooling system 2 enables greater functional complexity with significantly fewer components compared to the prior art.Accordingly, a multitude of operating states, i.e. operating modes of the cooling system 2, can be realized with the simply constructed cooling system 2, in particular the simply constructed coolant system 4.

[0055] The invention is not limited to the present exemplary embodiment. See, for example, the relevant statements in the introduction to the description. In contrast to the exemplary embodiment explained, it can be provided in other embodiments of the invention, for example, that no condenser analogous to the condenser 34 of the exemplary embodiment is present. Instead, the refrigerant circuit can only have a condenser analogous to the condenser 38 of the exemplary embodiment. Furthermore, it is conceivable that the component according to the characterizing part of claim 1 is not designed as a chiller of the battery sub-circuit, but as another component of the coolant system according to the invention. In the latter embodiment, it is of course also according to the invention if, in addition to the component with the component bypass line, a chiller is also used in the battery sub-circuit.

[0056] List of reference symbols

[0057] 2 Cooling system

[0058] 4 Coolant system

[0059] 6 Battery subcircuit

[0060] 8 Powertrain subcircuit

[0061] 10 Refrigerant circuit

[0062] 12 First coolant pump

[0063] 14 Battery

[0064] 16 Second coolant pump

[0065] 18 Powertrain

[0066] 20 Cooling air radiator

[0067] 22 components, designed as chillers

[0068] 24 component bypass line, designed as chiller bypass line

[0069] 26 multi-way valve

[0070] 28 Check valve

[0071] 30 Coolant heating

[0072] 32 coolant line

[0073] 34 Capacitor

[0074] 36 Compressor

[0075] 38 Additional capacitor

[0076] 40 dryers

[0077] 42 evaporators

[0078] 44, 46 Expansion valve

[0079] 48 switching valve

Claims

Coolant system for an electric vehicle and cooling system for an electric vehicle with a coolant system and a refrigerant circuit Patent claims 1. Coolant system (4) for an electric vehicle for circulating a liquid coolant, comprising a plurality of components (12, 14, 16, 18, 20, 22, 30, 34) through which the coolant flows, wherein the components (12, 14, 16, 18, 20, 22, 30, 34) can be connected to each other, at least in at least one subset, by means of at least one valve (26) and coolant lines (32) in a coolant-conducting manner, characterized in that the at least one valve (26) is designed as a single multi-way valve and a component bypass line (24) of the coolant system (4) is arranged to at least one of the components (22) through which the coolant flows such that this component (22) can be connected to the multi-way valve (26) in a coolant-conducting manner by means of the component bypass line (24).that in a first switching state of the multi-way valve (26) both the component bypass line (24) in a first flow direction and this component (22) are permeable to the coolant, and in a second switching state of the multi-way valve (26) the component bypass line (24) is permeable to the coolant in a second flow direction opposite to the first flow direction in the bypass to this component (22).

2. Coolant system (4) according to claim 1, characterized in that the plurality of components (12, 14, 16, 18, 20, 22, 30, 34) comprises at least a subset of the following components of a cooling system: coolant pump (12, 16), battery (14), chiller (22), coolant heater (30), powertrain (18) with an electric motor and a Power electronics for the electric motor, cooling air radiator (20) for heat exchange with a free environment, capacitor (34). Coolant system (4) according to claim 2, characterized in that the plurality of components (12, 14, 16, 18, 20, 22, 30, 34) has a chiller (22), wherein the component bypass line (24) is designed as a chiller bypass line and the chiller (22) is designed as the component by which flow can be bypassed in the second switching state of the multi-way valve (26) via the component bypass line (24), preferably that a component output designed as a chiller output can be connected to the multi-way valve (26) via the component bypass line (24) in a coolant-conducting manner.Coolant system (4) according to one of claims 1 to 3, characterized in that the plurality of components (12, 14, 16, 18, 20, 22, 30, 34) are arranged distributed over at least two coolant circuits (6, 8) of the coolant system (4), wherein the at least two coolant circuits (6, 8) can be connected to each other by means of the multi-way valve (26) via coolant conduction, preferably that on the one hand a first coolant pump (12) and / or the battery (14) and / or the chiller (22) and / or the coolant heater (30) are arranged in a first coolant circuit (6) and / or on the other hand a second coolant pump (16) and / or the powertrain (18) and / or the cooling air radiator (20) and / or the condenser (34) are arranged in a second coolant circuit (8).Coolant system (4) according to claim 4, characterized in that the first coolant circuit (6) is a battery sub-circuit, comprising the chiller (22), the first coolant pump (12), which, with respect to a flow through the first coolant pump (12) with the coolant, in. The coolant system (4) according to claim 5 is characterized in that the multi-way valve (26) is configured such that the powertrain sub-circuit (8) can be continuously supplied with coolant in all possible switching states of the multi-way valve (26) and during the transition of the multi-way valve (26) from one of these switching states to another.A coolant system (4) according to claim 5 or 6, referring back to claim 3, characterized in that one end of the chiller bypass line (24), with respect to a flow through the chiller (22) and the first coolant pump (12) with the coolant, is arranged to conduct coolant in the flow direction downstream of the chiller outlet and upstream of an inlet of the first coolant pump (12). A coolant system (4) according to any one of claims 5 to 7, characterized in that in the battery sub-circuit (6), with respect to a flow through the battery (14) with the coolant, a check valve (28) is additionally arranged in the flow direction downstream of the battery (14) such that the check valve (28) only allows a flow of the coolant from the battery (14) towards the multi-way valve (26). Coolant system (4) according to one of claims 5 to 8, characterized in that the battery sub-circuit (6) additionally has a coolant heater (30) for heating the battery (14) as required, wherein the coolant heater (30), with respect to a flow through the chiller (22) with the coolant, is arranged in the flow direction after the multi-way valve (26) and before the chiller (22), preferably that the chiller (22) and the coolant heater (30) are arranged in a common coolant line (32) of the battery sub-circuit (6), particularly preferably that the coolant heater (30) is designed as an electric heater.Coolant system (4) according to one of claims 4 to 9, characterized in that the coolant system (4) is designed such that, depending on the switching state of the multi-way valve (26), the following coolant-conducting connections can be realized, at least in a subset, preferably all, solely by means of the multi-way valve (26): a) coolant-conducting connection of the chiller (22) with the battery (14), b) coolant-conducting connection of the chiller (22) with the power electronics and the electric motor, c) coolant-conducting connection of the chiller (22) with the cooling air radiator (20), the power electronics and the electric motor, d) coolant-conducting connection of the chiller (22) with the battery (14), the power electronics and the electric motor, e) coolant-conducting connection of the chiller (22) with the battery (14), the cooling air radiator (20), the power electronics and the electric motor.Cooling system (2) for an electric vehicle, comprising on the one hand a coolant system (4) and on the other hand a refrigerant circuit (10), characterized in that the coolant system (4) is designed according to one of claims 1 to 10. Cooling system (2) according to claim 11, characterized in that the refrigerant circuit (10) is configured for air conditioning a passenger compartment of the electric vehicle and / or for temperature control of a coolant flowing in the coolant circuit (4). Cooling system (2) according to claim 12, referring back to claim 2, characterized in that the cooling system (2) is configured such that a heat transfer connection between the coolant system (4) on one side and the refrigerant circuit (10) on the other side can be established by means of the chiller (22) as required.Cooling system (2) according to claim 12 or 13, referring back to claim 2, characterized in that the cooling system (2) is designed such that a heat transfer connection between the coolant system (4) on one side and the refrigerant circuit (10) on the other side can be established by means of the condenser (34), preferably that the condenser (34) is arranged in a coolant-conducting manner in the drive train sub-circuit (8).

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