Vehicle cooling system and vehicle with such a

Abstract

Vehicle coolant system comprising at least two independently operable coolant circuits (3, 6, 7, 160), wherein at least a first coolant circuit (6, 7, 160) operates at a first temperature level and at least a second coolant circuit (3) operates at a second temperature level lower than the first temperature level, and wherein the first coolant circuit (6, 7, 160) is intended for temperature control of an internal combustion engine (8) or an electric machine (5) and the second coolant circuit (3) is intended for temperature control of an energy storage device (2), and wherein at least one recuperation device (37) is provided for thermally coupling the at least one first (6,7,160) and the at least one second coolant circuit (3), characterized by the fact that in the second coolant circuit (3) the recuperation device (37) is arranged in parallel to a heating device (32) by providing at least one proportional valve (34).

Description

[0001] The invention relates to a vehicle coolant system comprising at least two independently operable coolant circuits, wherein at least a first coolant circuit operates at a first temperature level and at least a second coolant circuit operates at a second temperature level that is lower than the first temperature level, and wherein the first coolant circuit is intended for temperature control of an internal combustion engine or an electric machine and the second coolant circuit is intended for temperature control of an energy storage device, as well as a vehicle with at least one energy storage device, in particular at least one internal combustion engine and at least one electric machine, and a vehicle coolant system comprising at least two independently operable coolant circuits.

[0002] Vehicles with at least one energy storage device in the form of a traction battery, at least one internal combustion engine, at least one electric motor, and at least one vehicle cooling system, as well as vehicle cooling systems comprising at least two independently operable coolant circuits, of which at least one first coolant circuit operates at a first temperature level and at least one second coolant circuit operates at a second, lower temperature level compared to the first, are known in the prior art. The first coolant circuit serves in particular to regulate the temperature of the vehicle's internal combustion engine or its electric motor. The second cooling circuit serves to regulate the temperature of the vehicle's traction battery. A traction battery is understood to be an energy storage device for powering vehicles with electric or hybrid drives, comprising an electric motor and an internal combustion engine.Since traction batteries are subject to cyclic charging and discharging processes, accumulators are typically used, in particular a combination of individual accumulator cells or blocks. Compared to device batteries, the cells of a traction battery have a significantly higher capacity. The driving voltage, or traction voltage, is obtained by connecting individual cells in series. Increasing the size of the cells or connecting them in parallel can increase the storage capacity and current carrying capacity. The product of the traction voltage and the electrical charge or galvanic capacitance of the individual cells or cells connected in parallel yields the energy content of the traction battery. Due to manufacturing processes and usage influences, the cells of a traction battery exhibit differences in capacity and current output resulting from varying internal resistance.As temperatures decrease, the mobility of electrons diminishes, which in turn reduces the traction battery's ability to deliver high currents. To counteract this effect, and because various battery technologies become unusable at lower temperatures, traction batteries are often equipped with a heating element. Therefore, both excessively high and excessively low temperatures pose problems for the operation of traction batteries, as cooling is required in the former case and heating in the latter.

[0003] Vehicles equipped with a traction battery temperature control system or a battery circuit for temperature control of the traction battery are known in the prior art. For example, DE 10 2009 060 860 A1 discloses an air conditioning system for a vehicle that comprises at least one refrigerant circuit and at least one temperature control circuit for temperature control of the vehicle interior and at least one vehicle component, wherein at least one device for heat absorption from the temperature control circuit and at least one device for heat transfer to the temperature control circuit are provided. In this system, the traction battery is temperature controlled by a coolant circuit with heat input and / or heat removal via the vehicle's refrigerant circuit. A different temperature level is required for temperature control of the traction battery than for the vehicle engine and auxiliary components as well as the vehicle interior.The air conditioning system handles both cooling and temperature control tasks, making its design quite complex.

[0004] DE 10 2009 059 240 A1 discloses a motor vehicle cooling system comprising a first cooling circuit for an electrical component of the vehicle to be cooled, a refrigeration system, and a refrigerant-coolant heat exchanger. A coolant circulates in the first cooling circuit to cool the electrical component. The cooling power provided by the refrigeration system is transferred to the coolant via the heat exchanger. The first cooling circuit also includes a first coolant-air heat exchanger for cooling air for the vehicle interior. The vehicle heating system comprises a fuel-operated heater and / or an electric resistance heater. The traction battery is thus temperature-controlled by integrating heating and cooling devices into the cooling circuit, which is quite complex. The circuits can only be decoupled from each other to a limited extent, i.e.,They can be operated independently of each other.

[0005] Some well-known vehicles with hybrid or electric drive systems include a refrigeration circuit, a heating and cooling circuit for the vehicle interior or passenger compartment, a cooling circuit for the electronic components, power electronics, electric motor, etc., and a battery circuit for the traction battery. An example of such a vehicle is the Opel Ampera, which includes a refrigeration circuit comprising a compressor, condenser, evaporator, and chiller, a heating and cooling circuit for temperature control of the vehicle interior, an electronics cooling circuit, and a battery temperature control circuit. Thus, this vehicle has one refrigeration circuit and three cooling circuits.

[0006] From DE 10 2010 060 230 A1, a temperature control system for a drive unit of a motor vehicle is known. This system comprises a first temperature control circuit, which is coupled to an electrical drive unit of the drive unit, a second temperature control circuit separate from the first temperature control circuit and coupled to an electrical energy storage device of the drive unit, and a heat exchanger for selectively transferring heat between the first temperature control circuit and the second temperature control circuit.

[0007] DE 10 2011 107 281 A1 discloses a chiller for cooling a heat source of a motor vehicle, comprising a plurality of refrigerant flow channels and a plurality of coolant flow channels. The coolant flow channels are formed by spaces provided between the refrigerant flow channels, with heat-transferring surfaces provided between a refrigerant and a coolant flowing in the coolant flow channels, preferably formed by at least partial regions of the walls of the coolant flow channels. In the region of the heat transfer surfaces, the refrigerant flow channels have a refrigerant-carrying volume that is larger by a factor F between 3 and 6 than the coolant-carrying volume of the coolant flow channels in the region of the heat transfer surfaces.

[0008] From EP 2 287 507 A2 a double-walled pipe is known which comprises a pipe shell with an outer wall and an inner wall and channels running parallel to each other in between, wherein the pipe shell consists of an outer and an inner pipe, at least one of which has projections in the direction of the inside of the pipe, wherein parallel shell channels are formed by the same being superimposed on top of each other.

[0009] DE 38 26 022 A1 discloses a heating system for a motor vehicle with an air-cooled rear engine, wherein a heating line of a heating circuit, equipped with a silencer, runs within body components of the motor vehicle. The heating line, together with the integrated silencer, is formed by a prefabricated, flexible assembly part, which, after the surface treatment of the motor vehicle, is inserted into the body component through an assembly opening provided in a front wheel arch and is connected at its end to adjacent components of the heating system or the body.

[0010] From EP 1 637 709 A2, a device for heat exchange in vehicles is known for increasing or decreasing the temperature of vehicle components, comprising a pump for pumping coolant through at least one cooling circuit, a first cooling circuit comprising at least two heat exchangers and at least one heat storage device, a second cooling circuit exchanging thermal energy with at least one first vehicle component, a third cooling circuit which can be optionally connected to the second cooling circuit and which exchanges thermal energy with at least one second vehicle component, and a number of control elements which optionally connect the first cooling circuit to at least one of the second and third cooling circuits and furthermore, independently, optionally connect the second and third cooling circuits.

[0011] The present invention is based on the objective of further developing a vehicle coolant system and a vehicle with such a system in such a way that very effective temperature control of the energy storage device, in particular the traction battery, is enabled, making it possible to operate at different temperature levels.

[0012] The problem is solved for a vehicle coolant system according to the preamble of claim 1 by arranging the recuperation device in the second coolant circuit in parallel with a heating device, including at least one proportional valve. For a vehicle with at least one energy storage device, at least one drive unit, in particular at least one electric motor in the case of an electric vehicle or at least one internal combustion engine and at least one electric motor in the case of a hybrid vehicle, and at least one vehicle coolant system comprising at least two independently operable coolant circuits, the problem is solved by the fact that the at least one vehicle coolant system is such a vehicle coolant system. Further developments of the invention are defined in the dependent claims.

[0013] This creates a vehicle in the form of an electric or hybrid vehicle with a vehicle cooling system, or a vehicle cooling system for such a vehicle, comprising at least a first and at least a second cooling circuit operating at two different temperature levels. The first cooling circuit is intended for temperature control of the vehicle's electric motor or internal combustion engine (in the case of a hybrid vehicle), and the second cooling circuit is intended for temperature control of the energy storage device, in particular a traction battery or the energy storage device of a fuel cell. To fulfill the various temperature control tasks, the first cooling circuit can also consist of several circuits. The at least one first and at least one second cooling circuit are thermally coupled to each other via the at least one recuperation device.The recuperation system, particularly when configured as a cooling water recuperation heat exchanger, serves to couple heat from the first coolant circuit into the second coolant circuit. Furthermore, it can fulfill cooling requirements in the first coolant circuit. If there is no heat demand from the energy storage system, the recuperation system can be switched off or bypassed to prevent heat transfer to the second coolant circuit.

[0014] The thermal coupling of the two coolant circuits via the recuperation system allows for energy recovery from one of the two coolant circuits and its use in the other. This enables heat transfer from one coolant circuit to the other, with the operation of the recuperation system being determined by the heat demand of the energy storage system or the second coolant circuit.

[0015] The vehicle is an electric or hybrid vehicle. For the respective electric powertrain, various configurations are possible, from the energy storage system, particularly in the form of a traction battery, to the electric motor. A recuperation system can also be advantageously incorporated into a fuel cell vehicle, which likewise includes an energy storage system and a coolant circuit for the electric motor. During power generation, the fuel cell produces waste heat, similar to an internal combustion engine, but at a significantly lower temperature. Typically, an inverter, such as a DC / AC converter, is used between the energy storage system, which provides direct current, and an electric motor, particularly a three-phase electric motor.Depending on the type of energy storage device, such as a fuel cell or traction battery, the operational voltage drop in the storage device varies as a DC voltage. This may necessitate an adjustment of the intermediate circuit voltage between the inverter and the energy storage device, for which a DC / DC converter can be advantageously used. Adjusting the intermediate circuit voltage can be used as an additional degree of freedom when optimizing efficiency. The energy storage device, in the form of a fuel cell or traction battery, is temperature-controlled, as mentioned above, by the second coolant circuit of the vehicle's cooling system, whereas the components of the electric motor, inverter, and DC / DC converter are only cooled, as they typically heat up during operation to such an extent that cooling is required for smooth operation.This is done using the first coolant circuit.

[0016] To ensure smooth operation of the energy storage device in the form of a traction battery, it should operate within a narrow temperature range, particularly between approximately 15°C and 25°C. This results in heating and cooling requirements for the energy storage device, depending on the driving conditions and ambient conditions, especially the ambient temperature. The second coolant circuit, serving as a temperature control circuit for the energy storage device, therefore advantageously comprises at least one cooling device, particularly an air-cooled cooling device; at least one chiller for supplemental cooling from a refrigeration circuit, such as a heat exchanger from a refrigeration system; at least one heating device, particularly a resistance heater (PTC heater); and at least one pump for circulating the coolant through the second coolant circuit and the energy storage device, particularly in the form of a traction battery.Furthermore, the second coolant circuit includes the recuperation device and valves or other devices for switching the at least one cooling device, the at least one chiller, and the at least one heating device on and off. The individual cooling and heating devices, in particular the at least one cooling device and the at least one heating device, are connected in parallel to each other in order to be able to switch on one or the other selectively, and accordingly only one component at a time, in order to keep the thermal mass of the circuit as low as possible.

[0017] It is advantageous to be able to switch the recuperation system on and off, for example, to switch it off from the second coolant circuit when this circuit is used to cool the energy storage unit, or to prevent heat transfer into the second coolant circuit via the recuperation system when there is no heat demand in the second coolant circuit with respect to the energy storage unit. Since the recuperation system has thermal mass, it is advantageous to provide at least one bypass device, in particular a bypass line, to bypass the recuperation system, so that its thermal mass has no influence on the energy storage unit or its cooling process.

[0018] To allow for the possibility of switching off the recuperation system, it is arranged in parallel to the heating system of the second coolant circuit. In this case, a

[0019] Proportional valve provided for switching the recuperation device on and off.

[0020] For example, 3 / 2-way valves can be used as valves. Furthermore, the second coolant circuit can include at least one expansion tank to allow for volume equalization of the coolant flowing in the second circuit during alternating cooling and heating operations.

[0021] As mentioned previously, the first coolant circuit cools the electric motor and other electrical components, such as the inverter and DC / DC converter. A separate cooling system is provided for this purpose. Furthermore, a charger is provided for charging the energy storage system, which is also cooled by the first coolant circuit during charging. For this purpose, the charger is connected in parallel to the electric motor and inverter in the first coolant circuit. The first coolant circuit operates at a significantly higher temperature than the second, as the components of the first circuit operate at a temperature of 50 to 70°C (e.g., 60°C), while those of the second operate at a temperature of 15 to 25°C.Depending on driving conditions and ambient conditions, it is also necessary to cool the components of the first coolant circuit. For this purpose, the recuperation system is integrated into the first coolant circuit along with the cooling system. The recuperation system extracts heat from the first coolant circuit, which is used, or can be used, to heat the energy storage device in the second coolant circuit. The recuperation system can be arranged in series between the electric motor and the cooling system. Alternatively, the recuperation system can be connected in parallel in a separate branch of the first coolant circuit, in parallel with both the electric motor and the battery charger.

[0022] As mentioned, the recuperation system can be arranged in series between the electric motor and the coolant system in the front section of the vehicle. It is also possible to arrange it in the central section of the vehicle, particularly in a longitudinal member and / or a tunnel extending through the vehicle, and / or in the vehicle underbody. Especially when arranged in a longitudinal member, the underbody, or a tunnel, the recuperation system can be positioned close to the energy storage device, particularly the traction battery. When the recuperation system is arranged in a longitudinal member, it is advantageous to design it as a tube-in-tube heat exchanger or as a heat exchanger with closely spaced tubes.When installing such a tube-in-tube heat exchanger, it is suitable not only for placement in the longitudinal frame of a vehicle, but also in its underbody or tunnel – i.e., in locations where a long, narrow design proves advantageous. The respective coolants of the first and second cooling circuits are fed into the tube-in-tube heat exchanger in counterflow through nested tubes, thus enabling heat transfer from the coolant of one cooling circuit to the other.

[0023] In a tube-in-tube design, the recuperation system comprises at least one inner tube and at least one outer tube through which the respective coolant of the first and second coolant circuits flows. The inner tube can be made of metal and the outer tube of plastic. Advantageously, the outer tube is materially bonded to at least one end-mounted connection, particularly by laser welding. The inner tube can be joined to the connection, particularly by push-fit. Other joining methods are also possible. If the same medium flows through the outer and inner tubes—that is, if the coolant flowing in the first and second coolant circuits is the same or a similar one—push-fit is sufficient, as no complications arise in the event of a leak due to potential reactions between the two coolants.If, on the other hand, different coolants are used, a material-bonded connection or at least a seal between the inner pipe and the connecting part proves advantageous. By constructing the inner pipe from a material with higher conductivity than the outer pipe, in particular by using a metal inner pipe such as aluminum or a thermally conductive plastic, particularly good heat transfer is possible from the coolant flowing in the inner pipe to the coolant flowing in the outer pipe coaxially surrounding the inner pipe.

[0024] To further improve heat exchange, the inner tube can be provided with external fins and / or a finned structure. This increases the surface area available for heat exchange and thus improves the heat exchange accordingly. Advantageously, the external fins or finned structure of the inner tube do not extend into the end section of the inner tube intended for connection to the end fittings, in order to facilitate trouble-free connection. Depending on the design of the fittings, however, it is generally possible for the external fins or finned structure to extend into the fittings themselves, provided that corresponding openings and / or grooves are provided to accommodate the fins or finned structure.

[0025] The coolant is thus guided in counterflow, particularly when the recuperation device is designed in the form of a tube-in-tube heat exchanger, in order to enable optimal heat exchange between the first and second coolant circuits.

[0026] A coolant based on water and glycol, for example, a coolant with a high glycol content of approximately 50%, can be used. The coolant flowing through the first coolant circuit is always at a higher temperature than the coolant flowing through the second coolant circuit. Instead of just one first coolant circuit, more than one can be provided. For example, a vehicle can have two or three coolant circuits, and, particularly in an electric vehicle, a heating circuit that provides heat for temperature control of the vehicle interior, i.e., can be activated for comfort purposes, and operates at a different temperature than the first coolant circuit, which is intended for cooling, in particular, the electric motor, as described above.Such a heating circuit can comprise at least one heating element, at least one pump, and at least one heat exchanger, wherein the heat exchanger is intended for heating the vehicle interior and can be part of an air conditioning unit for heating and cooling the vehicle interior. The heat exchanger can also serve to extract heat from the vehicle interior. The at least one heating element can be designed as a resistance auxiliary heater (PTC auxiliary heater).

[0027] A combustion engine coolant circuit in a hybrid vehicle serves two purposes: cooling the combustion engine and supplying the air conditioning system's heat exchanger for interior heating. In various hybrid vehicle types, the combustion engine can provide sufficient heat or energy for all necessary heating functions of the other components through its waste heat output. These different types of hybrid vehicles include full hybrids, mild hybrids, plug-in hybrids, and range extenders. A hybrid vehicle is defined as a vehicle in which propulsion is provided by two energy converters and two energy storage systems. One of these energy converters is the combustion engine, and the other is an electric motor or electric machine.The aforementioned traction batteries and fuel cells, on the one hand, and a fuel tank (for the combustion engine) on the other, can serve as energy storage devices. Full hybrid vehicles, as well as mild hybrid vehicles, are equipped with a combustion engine, an electric motor, and a traction battery. A full hybrid vehicle is a parallel hybrid in which both the combustion engine and the electric motor operate in parallel. A full hybrid vehicle includes an automatic start system and regenerative braking. Both motors, the combustion engine and the electric motor, contribute fully to propelling the vehicle. This also applies to the so-called mild hybrid. In both full and mild hybrid vehicles, the combustion engine's power output is very low at low speeds, necessitating a starter motor. The electric motor can deliver high power at low speeds and therefore provides acceleration assistance.

[0028] In a mild hybrid vehicle, the electric motor is significantly weaker than the combustion engine, while in a full hybrid vehicle, it is more powerful, allowing short distances to be driven electrically. The range of a full hybrid vehicle depends on the storage capacity of the traction battery. Driving electrically is not possible with a mild hybrid because the electric motor is too weak.

[0029] A plug-in hybrid vehicle is a vehicle whose traction battery can be charged by connecting it to a power outlet. Plug-in hybrid vehicles can operate as either parallel or series hybrids. In a series hybrid, the combustion engine drives a generator that provides energy to the electric motor. The vehicle is then powered solely by the electric motor. The combustion engine is also referred to as a range extender, as it increases the electric motor's driving range. Three operating modes can be distinguished in a plug-in hybrid vehicle: Charge Sustaining Mode, Charge Depleting Mode, and Blend Mode. In Charge Sustaining Mode, the vehicle is operated in such a way that the traction battery's charge level does not decrease. Accordingly, this mode is comparable to the drive technology of a full hybrid vehicle.The vehicle is powered by the combustion engine, with the electric motor serving to assist it. In Charge Depleting Mode, the vehicle is driven by the electric motor until its traction battery is depleted to a predetermined charge level. At this point, the vehicle automatically switches to combustion engine propulsion. In Blend Mode, the vehicle itself selects a mode adapted to the driving situation. Before the journey begins, precise information about the route length, permitted speeds, etc., is defined to select the ideal driving strategy.

[0030] The combustion engine cooling circuit in a hybrid vehicle can, for example, operate at a temperature of approximately 90°C. This cooling circuit can include an internal cooling system for starting the combustion engine. The aforementioned heat exchanger can be located in parallel within this circuit. In turn, the recuperation system can be connected in parallel to this to supply heat to the second cooling circuit for temperature control of the energy storage system, particularly the traction battery. This proves particularly advantageous because the temperature difference between the two circuits—the combustion engine cooling circuit and the second cooling circuit for temperature control of the traction battery or, more generally, the energy storage system—is quite significant. Consequently, the heat exchanger surface area can be relatively small while still achieving efficient heat transfer.

[0031] The first coolant circuit of the electric motor can be linked to the aforementioned heating circuit to utilize the additional components of the heating circuit as a heat source, particularly during winter operation of an electric vehicle when the waste heat from the electric motor is insufficient for heating. During purely electric driving, the heating circuit can be integrated into the first coolant circuit. The resulting combined circuit allows for cooling of the electric motor and other electrical components, such as the DC / DC converter and the inverter, via the cooling system for electrical components. Furthermore, the heat from the heating circuit can be used to heat the electric motor if necessary. The heating heat exchanger of the air conditioning unit, which regulates the vehicle interior temperature, is also advantageously integrated here to transfer heat to the vehicle interior.The recuperation system can be connected in series or parallel to the combined circuit. When connected in parallel, only selectable heating or cooling operation is possible. In particular, at very low temperatures, heating is the only possible function, with only minimal cooling possible via convection. At high temperatures, cooling is the only function. The temperature level of the combined circuit can be, for example, in the temperature range of 50 to 70°C, particularly at 60°C. When using a hybrid vehicle with an internal combustion engine, integrating the heating circuit into the first coolant circuit proves to be disadvantageous. In this case, two separate circuits are preferred to allow for independent cooling and heating functions.

[0032] To further explain the invention, exemplary embodiments are described below with reference to the drawings. These show: Fig. 1 a schematic diagram of a vehicle designed as an electric vehicle or hybrid vehicle with a coolant circuit according to the invention for temperature control of a traction battery as an energy storage device, Fig. 2 a schematic diagram of a vehicle designed as an electric vehicle or hybrid vehicle with a coolant circuit according to the invention for cooling an electric machine and other electrical components, Fig. 3 a schematic diagram of a hybrid vehicle with a cooling circuit according to the invention for an internal combustion engine, Fig. 4. A schematic diagram of an electric vehicle with a heating circuit. Fig. 5 a schematic diagram of an electric vehicle with a coolant circuit according to the invention for cooling an electric machine, wherein a heating circuit is integrated into the coolant circuit, Fig. 6 a sectional view through a recuperation device according to the invention in the form of a tube-in-tube heat exchanger, Fig. 7 a cross-sectional view of a ribbed recuperation device, and Fig. 8 a perspective detail view of the ribbed inner tube of the recuperation device according to Fig. 7.

[0033] Fig. Figure 1 shows a schematic diagram of a vehicle 1, which can be an electric vehicle or a hybrid vehicle. The vehicle includes an energy storage device 2, which can be in the form of a traction battery. Such an energy storage device operates within a narrow temperature range, in particular between 15 and 25 °C. To ensure this, the energy storage device is temperature-controlled accordingly. This is achieved by a coolant circuit 3. This circuit comprises, as shown in Figure 1, a cooling system 2, a cooling system 3, and a cooling system 2. Fig. Figure 1 shows a cooling unit 30, a chiller 31, and a heating unit 32. The chiller 31 is, in particular, a heat exchanger of a refrigeration system, and the heating unit 32 can, for example, be a resistance auxiliary heater (PTC auxiliary heater). The chiller 31 and the heating unit 32 are connected in parallel, with two valves 33, 34, designed here as 3 / 2-inch valves, being provided for switching the chiller and the heating unit on and off. The coolant circuit 3 also includes a pump 35 for pumping the coolant flowing through the lines of the coolant circuit 3. Furthermore, a volume expansion tank 36 is provided to compensate for volume fluctuations due to cooling or heating operation.

[0034] The coolant circuit 3 further comprises a recuperation device 37, which is designed in the form of a recuperation heat exchanger. According to the invention, this device is not arranged in series downstream of the heating device 32. Since the recuperation device 37 has thermal mass that could be a hindrance when cooling the energy storage unit 2, as cooling it would require an unnecessarily high energy input, it is possible to bypass the recuperation device 37. For this purpose, a bypass line 38 is provided. The line branch 39 comprising the recuperation device 37 and the bypass line 38 are connected to the coolant circuit 3 via connection points 40, 41 (a valve). In contrast to providing a bypass line 38 when the recuperation device 37 is connected in series with the heating device 32, the recuperation device 37 is connected in parallel to the heating device 32 according to the invention.In this case, the bypass line 38 is no longer required, since the recuperation device 37 can be switched on or off via a valve that is then provided.

[0035] The cooling and heating devices of the coolant circuit 3 are otherwise connected in parallel to each other in order to be able to switch them on and off selectively, depending on whether cooling or heating operation is required for the proper temperature control of the energy storage unit 2.

[0036] Fig. Figure 2 shows a schematic diagram of the vehicle 1, which can be configured as an electric or hybrid vehicle. This vehicle comprises an electric machine 5 and other electrical components, such as an inverter (DC / AC converter) 50, a DC / DC converter 51, and optionally other electrical components. A coolant circuit 6 is provided for cooling the electric machine 5 and the electrical components, in particular the inverter 50 and the DC / DC converter 51. This circuit includes, among other things, a cooling device 60. The coolant circuit 6 also includes a pump 61, a volumetric expansion tank 62 to allow for coolant volume compensation at different temperatures, and a valve 63.

[0037] The coolant circuit 6 also serves to cool a charger 52 for charging the energy storage device 2. Advantageously, the charger 52 is cooled during the charging of the energy storage device 2. In the coolant circuit 6, the charger 52 is arranged or connected in a parallel branch of the coolant circuit, i.e., in parallel with the electric machine 5 and the inverter 50.

[0038] Furthermore, the coolant circuit 6 also includes the recuperation device 37. The coolant circuit 3 for temperature control of the energy storage device 2 is thus thermally coupled to the coolant circuit 6 for cooling the electric machine 5 and the other electrical components of the vehicle 1 via the recuperation device 37. Since the coolant circuit 6 operates at a higher temperature level than the coolant circuit 3 for temperature control of the energy storage device 2, for example, at a temperature level of 50 to 60 °C, particularly 60 °C, due to the higher temperature level at which the electric machine 5 and the electrical components are operated, heat from the coolant circuit 6, which is hereinafter referred to as the first coolant circuit, can be coupled into the coolant circuit 3, which is hereinafter referred to as the second coolant circuit, via the recuperation device 37 for temperature control, i.e., heating, of the energy storage device 2.

[0039] As in Fig. As indicated in Figure 2, the recuperation heat exchanger can be connected in series between the electric motor 5 and the cooling unit 60. In this case, the recuperation unit 37 is located in the front area of ​​the vehicle. It is also possible to position the recuperation unit 37 in the central area of ​​the vehicle, in particular in the longitudinal members of the vehicle and / or in the vehicle underbody and / or in a vehicle tunnel. The positioning in a vehicle longitudinal member 10 is shown in dashed lines in Figure 2. Fig. 2 is also indicated. The vehicle longitudinal member 10 is also indicated here with a dashed line. When the recuperation device 37 is arranged in the central area of ​​the vehicle or in a longitudinal member and / or tunnel of the vehicle and / or in the vehicle underbody, an orientation towards the energy storage device 2, which is usually located more towards the rear of the vehicle, is possible. When the recuperation device 37 is arranged in the longitudinal member 10 of the vehicle 1, a so-called tube-in-tube design of the recuperation device 37 in the form of a so-called tube-in-tube heat exchanger or coaxial heat exchanger is particularly suitable. Furthermore, it is possible to join tubes that are not joined inside each other, but rather lie next to each other, in order to enable heat exchange of the coolant flowing in these tubes.

[0040] An example of a tube-in-tube heat exchanger 37 is shown in Fig. 6 shown. At the in Fig. In the embodiment of the recuperation device 37 shown in Figure 6, an inner tube 137 and an outer tube 138 are provided. The inner tube 137 is located approximately centrally within the outer tube 138, so that coolant can flow completely around the inner tube 137 through the outer tube 138 of the recuperation heat exchanger or recuperation device 37. The coolant flowing through the inner tube 137 can be directed in counterflow to the coolant flowing through the outer tube 138. This is indicated by arrows 139 and 140 in Figure 6. Fig. Figure 6 indicates that two connection parts 141 and 142 are arranged at the ends of the recuperation device 37, in the form of a tube-in-tube heat exchanger, for connecting the two coolant circuits 3 and 6. The first connection part 141 and the second connection part 142 are each materially bonded to the outer tube 138 to prevent coolant leakage at the joints. The two connection parts 141 and 142 can be positively connected to the inner tube 137 by push-fit, provided that the coolant flowing through the inner tube corresponds to that flowing through the outer tube. In the event of a leak, no incompatibility problems with the coolants will then occur. It is therefore sufficient to provide a so-called technically tight connection between the inner tube and the two connection parts 141 and 142.However, if different coolants are routed through the inner pipe 137 and the outer pipe 138 of the recuperation device 37, it proves advantageous to provide a material-bonded connection between the inner pipe 137 and the two connection parts 141, 142, or at least a reliable seal. In principle, a seal can also be provided to seal the push-fit connection even when the same coolants are routed through both pipes.

[0041] To enable particularly good heat transfer from the coolant of the second coolant circuit 6, which flows through the inner tube, to the coolant of the first coolant circuit 3, which flows through the outer tube 138, the inner tube 137 advantageously has a higher thermal conductivity than the outer tube 138. In particular, the inner tube 137 is made of a metal, such as aluminum, and / or a thermally conductive plastic. The outer tube 138 can also be made of a plastic.

[0042] To enable even better heat transfer from the coolant of the first coolant circuit 6 flowing through the inner tube 137 to the coolant of the second coolant circuit 3 flowing through the outer tube 138, fins 237 can be arranged on the outside of the inner tube 137. This is shown in the Fig. 7 and Fig. 8 indicated. The ribs extend in the Fig. The cross-sectional view shown in Figure 7 extends radially from the inner tube 137 towards the outer tube 138. A different type of external rib structure may also be arranged on the inner tube 137. This is shown in particular in the detailed view of the inner tube 137 in Figure 7. Fig. As can be seen from section 8, the externally arranged ribs 237 do not extend to the ends of the inner tube 137, but terminate at a distance from them. This leaves a rib-free connection area 238 at the end of the inner tube 137, allowing the inner tube 137 to be easily connected to the two connection parts 141, 142. Depending on the design of the connection parts 141, 142, however, the ribs 237 can also extend to the respective end of the inner tube 137. This is shown in Fig. However, number 6 was not shown.

[0043] Fig. Figure 3 shows a schematic diagram of vehicle 1 in its configuration as a hybrid vehicle. This can be configured as a full hybrid, mild hybrid, or range-extender hybrid. A characteristic of a hybrid vehicle is the combination of two energy converters, one of which is an internal combustion engine 8 and the other an electric motor or electric machine 5. Two energy storage devices are also provided: a traction battery or fuel cell and a fuel tank. Fig. Figure 3 shows a cooling circuit 7 for the internal combustion engine 8. The cooling circuit for the internal combustion engine 8 comprises a cooling device 70 and a pumping device 71 for circulating the coolant through the lines of the cooling circuit 7. A heating heat exchanger 72 of an air conditioning unit (HVAC) is also provided in the cooling circuit 7, which serves to heat the interior of the vehicle. The heating heat exchanger of the air conditioning unit, which itself is located in Fig. The unit 3, which is not shown, is connected in parallel to the combustion engine 8, the pump unit 71, and the cooling unit 70. A valve 73 is provided for selectively switching the flow connection to the heating heat exchanger 72 or the cooling unit 70. Furthermore, a volume expansion tank 75 is provided for volume compensation.

[0044] To provide an internal cooling circuit when starting the combustion engine 8, a bridging line 74 is also connected to the valve 73, in parallel with the heating heat exchanger 72. To utilize the waste heat provided by the combustion engine for heating tasks required in the second coolant circuit 3 for temperature control of the energy storage unit 2, the recuperation device 37 can be connected in parallel with the heating heat exchanger 72 in circuit 7. The heat provided here passes as a coolant flow through the inner tube 137 of the [unclear text]. Fig. The recuperation device 37 shown in Figure 6 allows heat transfer from the coolant of cooling circuit 7, which is heated by the waste heat from the combustion engine 8, to the coolant of cooling circuit 3 for temperature control of the energy storage unit 2 by means of appropriate switching in the area of ​​valve 73. Since the cooling circuit 7 for the combustion engine is operated at a comparatively high temperature level due to the waste heat emitted by the combustion engine 8, for example at a temperature level of approximately 90°C, sufficient energy is generated that can be made available for heating outputs in other circuits, such as, in particular, the coolant circuit 3 for temperature control of the energy storage unit 2.Since the temperature difference in the cooling circuit 7 for the combustion engine is relatively large compared to the temperature in the coolant circuit 3 for tempering the energy storage unit 2, a relatively small heat exchanger surface area is already sufficient to enable good heat transfer.

[0045] In Fig. Figure 4 shows a heating circuit 9 of vehicle 1 in the training scenario as an electric vehicle. This includes a heating heat exchanger 90, which is part of a climate control (HVAC) unit (not shown) for heating the vehicle's interior. If the vehicle were a hybrid vehicle, the heating heat exchanger 90 would be identical to the heating heat exchanger 72, which is shown in Fig. 3 is shown. Since the one in Fig. Since the vehicle shown in Figure 4 is a purely electric vehicle, no internal combustion engine is provided whose waste heat could be used to heat the vehicle interior. Accordingly, a heating device 91 is arranged in the heating circuit 9 of an electric vehicle. Furthermore, the heating circuit 9 includes a pump device 92 and a volume expansion tank 93. The heating device 91 can, for example, be a resistance auxiliary heater (PCT auxiliary heater). The temperature level of the heating circuit 9 is approximately the same as that of the coolant circuit 6 for cooling the electric motor 5.

[0046] In Fig. 5 is opposite to the in Fig. In the second embodiment of the coolant circuit shown, a modified coolant circuit 160 is shown. This also serves to cool the electric machine 5 and is intended for electric vehicles. A heating circuit 161 is also integrated into the coolant circuit 160, which is essentially the same as the one shown in Figure 2. Fig. This corresponds to the assembly shown in Figure 4. This assembly in turn comprises a heating heat exchanger 162, a heating unit 163, and a pump unit 164. The heating heat exchanger 162 can be switched on and off via a valve 165, and the heating unit 163 via a valve 166. The heating heat exchanger 162 is itself part of an air conditioning unit, which is located in Fig. 5, however, is not shown. The two components of the heating heat exchanger and, in particular, the heating device make it possible to provide a sufficient amount of heat even during winter operation of the vehicle, especially for the vehicle interior via the heating heat exchanger 162, since the waste heat from the electric machine 5 will not be sufficient for heating during winter operation.

[0047] In order to utilize the heat generated in this combined circuit of coolant circuit 160 and heating circuit 161 for temperature control of the energy storage device 2 in the second coolant circuit 3, the recuperation device 37 is also coupled into the coolant circuit 160. According to the invention, this device is connected in parallel to the electric machine 5 with inverter 50 or the heating device 163. This is indicated by dashed lines in Fig. 5 indicated.

[0048] The coolant circuit 160 operates at a temperature level of approximately 50 to 70 °C, particularly around 60 °C. Integrating the heating circuit 161 into the coolant circuit 160 is typically only advantageous during purely electric driving. The tasks of the combined cooling and heating circuit—cooling the electrical components and heating, in particular, the vehicle interior, but also via the energy storage system 2's recuperation unit 37—are accomplished by connecting the heating circuit 161 or its components in parallel. At high temperatures, only cooling occurs, and at low temperatures, only heating takes place.

[0049] In the second coolant circuit 3, the recuperation device 37, as mentioned above, is connected in parallel to the heating device 32, which enables preheating, according to the invention. In parallel connection, control is achieved via a proportional valve. In non-inventory series connection of the recuperation device 37, switching on and off is achieved via the bypass line 38. To avoid having to cool the thermal mass of the recuperation device 37 during cooling operation of the energy storage unit 2, it can be bypassed via the bypass line 38 during cooling operation. If additional heating in the second coolant circuit 3 is not required, the recuperation device is switched off; in parallel connection according to the invention, it is switched out of the circuit via the valve.

[0050] The recuperation unit 37 thus utilizes the waste heat or heat generated in the other circuits to make it available to the second coolant circuit 3 for temperature control of the energy storage unit 2. This enables very economical operation, since waste heat from other circuits is used to temperature control or heat the energy storage unit 2, while the thermal mass of the recuperation unit does not prove to be a disadvantage for temperature control of the energy storage unit 2, due to its ability to be bypassed in the coolant circuit 3, if only cooling of the energy storage unit 2 is required.

[0051] Vehicle 1, currently being trained as an electric vehicle, includes in particular the components specified in the Fig. 1, Fig. 2 and Fig. 4 or in the Fig. 1 and Fig. The 5 circuits and components shown, in training as a hybrid vehicle, are located in the Fig. 1, Fig. 2 and Fig. 3 cycles and components shown.

[0052] In addition to the embodiment variants of vehicle coolant systems described above and shown in the exemplary embodiments, comprising at least two independently operable coolant circuits, numerous other variants can be formed, including any combinations of the aforementioned exemplary embodiments and features, in each of which at least one recuperation device is provided for thermally coupling the at least one first and the at least one second coolant circuit. Reference symbol list 1 vehicle 2 Energy storage 3 Coolant circuit 5 electric machine 6 Coolant circuit 7 Cooling circuit internal combustion engine 8 Internal combustion engine 9 Heating circuit 10 vehicle longitudinal beams 30 Cooling equipment 31 Chiller 32 Heating system 33 Valve / 3 / 2 Valve 34 valve / 3 / 2 valve 35 Pumping equipment 36 volume expansion tanks 37 Recuperation unit 38 Bypass line 39 Branch line 40 first junction 41 second interchange 50 Inverter 51 DC / DC converters 52 charger 60 Cooling unit 61 Pumping equipment 62 volume expansion tanks 63 Valve 70 Cooling unit 71 Pumping unit 72 heating heat exchangers 73 Valve 74 Management 75 Volume expansion tanks 90 heating heat exchangers 91 Heating system 92 Pumping equipment 93 Volume expansion tanks 137 Inner tube 138 Outer tube 139 Arrow 140 Arrow 141 first connection part 142 second connection part 160 Coolant circuit 161 Heating circuit 162 heating heat exchangers 163 Heating system 164 Pumping equipment 165 valve 166 Valve 237 rib 238 rib-free connection area

Claims

[1] Vehicle coolant system, comprising at least two independently operable coolant circuits (3, 6, 7, 160), wherein at least one first coolant circuit (6, 7, 160) operates at a first temperature level and at least one second coolant circuit (3) operates at a second temperature level which is lower than the first temperature level, and wherein the first coolant circuit (6, 7, 160) is provided for controlling the temperature of an internal combustion engine (8) or an electric machine (5) and the second cooling circuit (3) is provided for controlling the temperature of an energy store (2), and wherein at least one recuperation device (37) is provided for thermally coupling the at least one first (6, 7, 160) and the at least one second coolant circuit (3), characterized by , that in the second coolant circuit (3) the recuperation device (37) is arranged parallel to a heating device (32) with the provision of at least one proportional valve (34). [2] Vehicle coolant system according to claim 1, characterized by that the second coolant circuit (3) comprises at least one cooling device (30), at least one chiller (31) and at least one heating device (32) which are arranged parallel to one another, and the recuperation device (37) is arranged so as to be switchable on and off. [3] Vehicle coolant system according to one of the preceding claims, characterized by that the recuperation device (37) is designed in the form of a heat exchanger, in particular as a tube-in-tube heat exchanger with at least one inner tube (137) and at least one outer tube (138). [4] Vehicle coolant system according to claim 3, characterized bythat the inner tube (137) consists of a conductive material, in particular metal and / or a thermally conductive plastic, and the outer tube (138) consists of plastic. [5] Vehicle coolant system according to claim 3 or 4, characterized by that the outer tube (138) is materially connected to at least one connecting part (141,142) provided at the end, in particular by laser welding. [6] Vehicle coolant system according to one of claims 3 to 5, characterized by that the inner tube (137) is joined to one or the connecting part (141,142), in particular by plugging. [7] Vehicle coolant system according to one of claims 3 to 6, characterized by that the inner tube (137) is provided with external ribs (237) and / or a rib structure. [8] Vehicle coolant system according to one of the preceding claims, characterized bythat the recuperation device (37) is arranged in at least one vehicle longitudinal member (10) and / or in the vehicle underbody and / or in a vehicle tunnel. [9] Vehicle coolant system according to one of the preceding claims, characterized by that the recuperation device (37) is arranged in the front area of ​​the vehicle (1) or in the middle or rear area of ​​the vehicle in the direction of or in the area of ​​the energy storage device (2). [10] Vehicle coolant system according to one of the preceding claims, characterized by that the at least one recuperation device (37) is provided in an internal combustion engine cooling circuit (7), wherein the recuperation device (37) is arranged such that falling heat is released to the second coolant circuit (3). [11] Vehicle coolant system according to one of the preceding claims, characterized bythat the recuperation device (37) is arranged in the first coolant circuit (6,160) in series between the electric machine (5) and a cooling device (60). [12] Vehicle coolant system according to one of the preceding claims, characterized by that a heating circuit (161) is integrated into the coolant circuit (160) of the electrical machine (5). [13] Vehicle coolant system according to claim 12, characterized by that the heating circuit (161) comprises at least one heat source (163) and at least one heating heat exchanger (162) of an air conditioning unit for dissipating heat to the vehicle interior. [14] Vehicle coolant system according to one of the preceding claims, characterized by that the at least two coolant circuits (3,6,7,160) are provided with an identical or similar coolant. [15] Vehicle (1) with at least one energy storage device (2), at least one drive unit, in particular at least one electric machine (5) or at least one internal combustion engine (8) and at least one electric machine (5), and at least one vehicle coolant system, comprising at least two independently operable coolant circuits (3, 6, 7, 160), wherein the at least one vehicle coolant system is a vehicle coolant system according to one of the preceding claims.

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