Thermomanagementsystem

Abstract

Thermal management system (1), in particular for a motor vehicle, comprising a heat pump (2) with a refrigerant circuit (3) and at least one temperature control circuit (8, 9) thermally coupled to the refrigerant circuit (3) of the heat pump (2), in which temperature control circuit (8, 9) at least one thermal consumer can be thermally integrated or is integrated, wherein at least one thermal consumer is designed as an electrical device (10), wherein the thermal management system (1) is designed to guide a dielectric temperature control medium, in particular oil, along at least one electrical component of the electrical device (10) in the at least one temperature control circuit (8, 9).

Description

[0001] The invention relates to a thermal management system, in particular for a motor vehicle, comprising a heat pump with a refrigerant circuit and at least one temperature control circuit thermally coupled to the refrigerant circuit of the heat pump, in which temperature control circuit at least one thermal consumer can be thermally integrated or is integrated, wherein at least one thermal consumer is designed as an electrical device.

[0002] Thermal management systems comprising a heat pump with a refrigerant circuit coupled to a temperature control circuit in which at least one thermal consumer is integrated, are generally known from the prior art. For example, such thermal management systems are used in buildings or motor vehicles to achieve a defined temperature control of the temperature control fluid in the temperature control circuit through heat exchange between the refrigerant circuit and the temperature control fluid circuit, so that, in turn, temperature control of the thermal consumer is possible via thermal exchange between the thermal consumer and the temperature control fluid in the temperature control fluid circuit.

[0003] Specifically, electrical equipment, including electrical machines (i.e., electric motors and / or generators), electrical control devices (especially power electronics), electrical energy storage devices (e.g., high-voltage batteries), and the like, are integrated into the temperature control circuit as thermal consumers. Such electrical equipment can be integrated as thermal consumers together with other thermal consumers in the temperature control circuit or in different temperature control circuits.

[0004] To regulate the temperature of electrical equipment, it is known that different requirements apply to the temperature control medium compared to other thermal loads. In particular, it is usually necessary to prevent direct contact between the components of the electrical equipment and the temperature control medium, since an electrically conductive temperature control medium, for example water or a water-glycol mixture, is typically used.Since sufficient electrical insulation of the electrical equipment cannot be guaranteed throughout the entire operation of the thermal management system if the temperature control fluid comes into direct contact with it, a heat conduction structure is usually placed between the temperature control fluid circuit and the electrical equipment, so that the electrical equipment is only in thermal contact with the temperature control fluid via the heat conduction structure and does not come into direct contact with the temperature control fluid.

[0005] For example, the electrical device itself can have a heat exchanger, which may be designed as a thermally conductive plate. It is also known that electrical components of the electrical device are thermally coupled to such a heat exchanger, for example via a thermal paste, with the heat exchange with the temperature control fluid of the temperature control circuit taking place through the heat exchanger. This means that a direct heat transfer from the electrical device to the temperature control fluid is not possible, but rather an indirect heat transfer occurs from the electronic component, possibly via the thermal paste, into the heat exchanger and from there into the temperature control fluid.

[0006] This leads, firstly, to reduced heat dissipation from the electrical equipment compared to direct heat dissipation, and secondly, to inertia in the heat transfer. Furthermore, the described procedure requires additional effort, particularly regarding the components to be installed, especially the heat exchanger, and the installation space required for them.

[0007] The invention is based on the objective of providing an improved thermal management system in which the temperature control of the electrical equipment is improved.

[0008] The problem is solved by a thermal management system with the features of claim 1. Advantageous embodiments are the subject of the dependent claims.

[0009] As described, the invention relates to a thermal management system. The thermal management system can be part of a motor vehicle, for example, to regulate the temperature of assemblies, equipment, sections, or components of the vehicle. Alternatively, the thermal management system can also be part of a building. The thermal management system comprises a heat pump with a refrigerant circuit, wherein the heat pump, as is known per se, is designed to circulate refrigerant within the refrigerant circuit. For this purpose, the heat pump has a compressor that compresses the refrigerant and thereby circulates or pumps it within the refrigerant circuit. After the compressor, the refrigerant is typically fed to a condenser or condenser heat exchanger, then expanded by an expansion valve and fed to an evaporator or evaporator heat exchanger. The refrigerant then returns to the compressor.

[0010] The at least one temperature control circuit, to which the refrigerant circuit of the heat pump is thermally coupled, can therefore be temperature-controlled depending on its connection to the refrigerant circuit, for example, at the evaporator or the condenser. The term "temperature control" thus refers to heating or cooling. Depending on which temperature control circuit a component or thermal consumer is integrated into, and at which point within that circuit, it is temperature-controlled accordingly, i.e., heated or cooled. A distribution device can be provided to control or regulate contact with the temperature control medium, i.e., to selectively integrate or disconnect thermal consumers from a temperature control circuit. It is also possible to selectively adjust the flow rate of the temperature control medium to individual thermal consumers.

[0011] As described, at least one thermal consumer is designed as an electrical device. The term "electrical device" can generally be understood to mean any device that is operated with electrical energy, stores electrical energy, generates electrical energy, conducts electrical signals, in particular carries an electric current or an electric voltage, or combinations thereof. Specifically, and especially when the thermal management system is assigned to a motor vehicle, an electric machine intended as a drive device and / or an electrical energy storage device, in particular a high-voltage battery, and / or control electronics or power electronics can be understood as an electrical device.

[0012] The invention is based on the finding that the thermal management system is configured to guide a dielectric temperature control fluid, in particular oil, along at least one electrical component of the electrical device in at least one temperature control fluid circuit. Within the scope of this application, the phrase "guide along an electrical component" is understood in particular to mean the direct guidance of the temperature control fluid over the electrical component, or flowing through or over the electrical component. The temperature control fluid therefore makes direct contact with the electrical component. Consequently, direct thermal contact is established between the temperature control fluid and the surface of the electrical component. This thermal contact is thus not established via an additional device, in particular without an additional heat exchanger. The temperature control fluid comes into direct contact with the surface of the electrical component.

[0013] Electrical components are understood to be, in particular, electrical or electronic components, for example, electrical conductors, electrical connectors, cells of an electrical energy storage device, electrical or electronic components such as coils, transistors, resistors, and the like. The use of a dielectric temperature control fluid prevents an electrical connection between the electrical device and the dielectric fluid. This allows the heat generated by the electrical device or component during operation to be dissipated directly at its source and transferred into the temperature control fluid.

[0014] Even though dielectric cooling fluids have a lower density and heat capacity compared to other cooling fluids, such as water, the direct dissipation of heat at its source is advantageous. Furthermore, this eliminates the need for additional structures, particularly heat exchangers, and consequently, the associated installation space requirements. As a result, heat dissipation is less sluggish, and temperature changes are more readily detectable, allowing for improved control of the thermal management system and ultimately leading to higher system performance. A dielectric cooling fluid can be any type of fluid, especially a liquid. It is electrically non-conductive or poorly conductive. Oil is commonly used as a dielectric cooling fluid.

[0015] Following further development of the thermal management system, it can be provided that the thermal management system has at least two temperature control circuits, in particular a heating circuit coupled with a condenser heat exchanger of the heat pump and a cooling circuit coupled with an evaporator heat exchanger of the heat pump, wherein at least one temperature control circuit has a dielectric temperature control medium and at least one temperature control circuit has a water-comprising temperature control medium, in particular a water-glycol mixture.

[0016] The described design makes it possible to utilize the advantages of different temperature control media. Specifically, the temperature control circuit in which at least one electrical device, or an electrical device where the most direct possible heat dissipation from the electronic component is desired, is located can contain the dielectric temperature control medium. The temperature control circuit containing water can benefit from water's higher density and heat capacity and thus, for example, since no electrical components need to be cooled there, can also allow the temperature control medium to flow directly through a thermal consumer requiring cooling, such as a heating device.

[0017] In one embodiment, a temperature control circuit, particularly a heating circuit, coupled to a condenser heat exchanger of the heat pump can be configured to carry a dielectric temperature control fluid. For example, the temperature control circuit carrying the dielectric temperature control fluid can be designed as a heating circuit, i.e., thermally coupled to the condenser heat exchanger of the heat pump. This means, in particular, that the dielectric temperature control fluid flows through the side of the temperature control circuit of the condenser heat exchanger. A heating device or interior heater, i.e., for example, a cabin heater of a motor vehicle, is arranged in the heating circuit or temperature control circuit coupled to the condenser heat exchanger. This allows the interior heater or heating device to also be supplied with the dielectric temperature control fluid.The heating device, especially when viewed in the direction of flow of the temperature control fluid, can represent the first thermal consumer after the condenser heat exchanger.

[0018] By integrating the electrical equipment into the temperature control circuit associated with the condenser heat exchanger, suitable temperature control of the electrical equipment is still possible, since it is typically operated at higher temperatures and can therefore simultaneously be used to control the temperature of the heating circuit. In other words, the heat dissipation from the electrical equipment, for example, the electrical energy storage device or the electric motor, can be used to heat the temperature control fluid in the temperature control circuit coupled to the condenser heat exchanger. Furthermore, the thermal management system may be designed so that at least one electrical energy storage device and / or at least one electric motor and / or an inverter, in particular a drive unit of a motor vehicle equipped with the thermal management system, can be thermally integrated into or is already integrated into the temperature control circuit.

[0019] The flow sequence in the temperature control fluid circuit is generally arbitrary and can be changed if necessary, for example, via at least one valve. It is advantageous to position the heating element as the first thermal consumer after the condenser heat exchanger in order to utilize the temperature control fluid with the highest temperature for heating. This results in the greatest heat exchange with the temperature control fluid, for example, by transferring heat to the interior or passenger compartment of the vehicle. Subsequently, heat can be dissipated from the electrical system, or it is equally possible to input heat into the electrical system, for example, to preheat a battery or for general heating. As already described, the individual thermal consumers can be connected to their respective temperature control fluid circuits independently, for example, depending on an operating condition such as the current temperature.

[0020] Furthermore, the thermal management system may provide for the electrical energy storage device to be arranged upstream or downstream of the at least one electrical machine. In addition to the electrical machine and the electrical energy storage device, an inverter for operating the electrical machine may also be arranged in the temperature control circuit. Optionally, the inverter may also be arranged in a different temperature control circuit, for example, a cooling circuit. It may be advantageous for the electrical energy storage device and / or the at least one electrical machine to also be optionally heated in a specific operating state.Specifically, the temperature control fluid can flow through the electrical energy storage device after the heating device and then through the inverter and the at least one electrical machine, or through the inverter and the at least one electrical machine after the heating device and then through the electrical energy storage device.

[0021] A radiator can also be provided in the temperature control circuit. Specifically, a radiator, or radiators, can be provided in both the first temperature control circuit, which can be considered a heating circuit, and the second temperature control circuit, which can be considered a cooling circuit. In this embodiment, a radiator can be arranged in the temperature control circuit carrying the dielectric temperature control fluid, particularly upstream of the electrical energy storage device. Alternatively, the electrical energy storage device can also be arranged upstream of the radiator. In any case, the radiator can be used to dissipate excess heat to the environment or to harvest thermal energy from the environment, specifically in a so-called "harvesting state."If the electrical energy storage device is positioned upstream of the radiator, it can be cooled more effectively because, if necessary, thermal energy can first be dissipated to the environment via the radiator. Specifically, the radiator can be positioned upstream of the condenser heat exchanger, or the electrical energy storage device can be positioned between the condenser heat exchanger and the radiator.

[0022] The thermal management system can further include a temperature control circuit, particularly a cooling circuit, coupled to an evaporator heat exchanger of the heat pump, designed to carry a dielectric temperature control fluid. As already described, any number of temperature control circuits can be configured. Specifically, one temperature control circuit can be coupled to the evaporator heat exchanger and another to the condenser heat exchanger. It is also possible for multiple temperature control circuits to be selectively coupled to either the evaporator heat exchanger and / or the condenser heat exchanger. Accordingly, configurations are possible in which the temperature control circuit coupled to the evaporator heat exchanger carries the dielectric temperature control fluid, and the temperature control circuit coupled to the condenser heat exchanger carries a water-based temperature control fluid, or vice versa.

[0023] By coupling the temperature control circuit, which uses a dielectric temperature control fluid, with the evaporator heat exchanger, a cooling circuit with a dielectric temperature control fluid can be implemented. This circuit can accommodate electrical devices or components, such as DC-DC converters, charging ports, and the like, which typically have higher cooling requirements or do not necessarily need to be heated. Furthermore, the electrical devices described earlier can also be integrated into the cooling circuit.

[0024] For example, the electrical energy storage device and / or at least one electric machine and / or at least one inverter can be thermally integrated into the cooling fluid circuit coupled to the evaporator heat exchanger. This allows, in particular, the targeted removal of thermal energy from the aforementioned electrical components to cool them optimally. In the direction of the cooling fluid flow, a sequence is possible in which the inverter is integrated first, then the electric machine, followed by a radiator, then a battery, and finally a charging port and / or a DC-DC converter. The order of the individual components can be changed.

[0025] As previously described, a radiator can be thermally integrated into the temperature control circuit coupled to the evaporator heat exchanger. Specifically, the battery or electrical energy storage device can be located downstream of the radiator in the flow direction of the temperature control fluid. Alternatively, the electrical energy storage device can have its own dedicated radiator or sub-circuit within the temperature control circuit. For example, temperature control fluid can be selectively supplied to the electrical energy storage device after it has flowed through the radiator, such as to provide the electrical energy storage device with the lowest temperature fluid or after thermal energy has been dissipated to the environment by the radiator.

[0026] In addition to the thermal management system, the invention relates to a motor vehicle comprising a described thermal management system. Furthermore, the invention relates to a method for controlling the operation of a thermal management system, in particular as described above, comprising a heat pump with a refrigerant circuit and at least one temperature control circuit thermally coupled to the refrigerant circuit of the heat pump, in which at least one thermal consumer can be thermally integrated or is integrated, wherein at least one thermal consumer is designed as an electrical device, and wherein a dielectric temperature control medium, in particular oil, is guided along at least one electrical component of the electrical device in the at least one temperature control circuit.

[0027] All advantages, details, and features described in relation to the thermal management system are fully transferable to the motor vehicle and the procedure. In particular, the procedure can be carried out in its entirety on the described thermal management system.

[0028] The invention is explained below with reference to exemplary embodiments and the figures. The figures are schematic representations and show: Fig. 1 a schematic representation of a thermal management system according to a first embodiment; Fig. 2 a schematic representation of a thermal management system according to a second embodiment; Fig. 3 a schematic representation of a thermal management system according to a third embodiment; Fig. 4 a schematic representation of a thermal management system according to a fourth embodiment; Fig. 5 a schematic representation of a thermal management system according to a fifth embodiment; and Fig. 6 A schematic representation of a thermal management system according to a sixth embodiment.

[0029] Fig. Figure 1 shows a thermal management system 1, which is intended, for example, for a motor vehicle or forms part of a motor vehicle not shown in detail. The following description is therefore also applicable to a motor vehicle that includes such a thermal management system 1.

[0030] In one embodiment, the thermal management system 1 comprises a heat pump 2 with a refrigerant circuit 3. The heat pump 2 is of a known design and includes a compressor 4, a condenser heat exchanger 5, an expansion valve 6, and an evaporator heat exchanger 7. The thermal management system 1 has temperature control circuits 8 and 9. In principle, the temperature control circuits 8 and 9 can be connected to any thermal consumers and can be connected to the condenser heat exchanger 5 and the evaporator heat exchanger 7 as desired, depending on the temperature control required for the individual thermal consumers. The arrangement and thermal integration of the individual thermal consumers can therefore be modified or is selected differently in the various embodiments and can be modified, exchanged, or combined accordingly.

[0031] Each temperature control circuit 8, 9 contains a temperature control medium, wherein at least one of the temperature control circuits 8, 9 contains a dielectric temperature control medium, for example, a dielectric fluid, in particular oil. The dielectric temperature control medium is accordingly non-conductive or only poorly conductive, so that at least one electrical device 10 can be temperature-controlled directly by the dielectric temperature control medium, i.e., in particular without an interposed structure, for example, without an interposed heat exchanger. Specifically, an electrical component, for example, an electrical connection element, an electrical conductor element, an electrical or electronic component, or the like, is directly exposed to the temperature control medium; i.e., its surface is directly contacted by the temperature control medium.

[0032] This is just one example showing Fig. 1. A temperature control circuit 8, which is thermally coupled to the condenser heat exchanger 5, carries a dielectric temperature control fluid. In the flow direction of the temperature control fluid, the fluid flows through a heating device 11 after the condenser heat exchanger 5 and then through at least one electric machine 12, where two electric machines are shown by way of example. Subsequently, the temperature control fluid flows through an electrical energy storage device 13 or a battery and then a radiator 14 and returns to the condenser heat exchanger 5. Advantageously, the electrical devices 10, namely the electric machine 12 and the electrical energy storage device 13, can be directly supplied with the dielectric temperature control fluid.

[0033] For example, in the electric machines 12, the electrical conductor elements or winding heads can be directly surrounded or permeated by the dielectric temperature control fluid, thus transferring heat directly. Similarly, the cells of the electrical energy storage device 13 can be in direct thermal and mechanical contact with the temperature control fluid, eliminating the need for an intermediate structure. In particular, a thermal interface material is not required to couple the thermal cells with thermal paste, with the temperature control fluid communicating with the thermal interface material via thermal conduction. This results in a less sluggish and more direct temperature control in the thermal management system 1, thus requiring less power reserve and allowing for the use of higher temperature limits.

[0034] By integrating it into the heating circuit or the temperature control circuit 8 connected to the condenser heat exchanger 5, it is also possible to preheat the electrical equipment 10, in particular the electrical machines 12 and the electrical energy storage device 13, for example at low ambient temperatures. Fig. Figure 1 shows, by way of example, that a pump 15 for conveying the temperature control fluid in the temperature control fluid circuit 8 is arranged between the radiator 14 and the condenser heat exchanger 5. In contrast, in Fig. Figure 2 shows that the pump 15 is arranged upstream of the radiator 14. Likewise, unlike Figure 2, the pump 15 is arranged upstream of the radiator 14. Fig. 1 in Fig. Figure 2 shows that the electrical machines 12 are arranged downstream of the electrical energy storage device 13, i.e., between the electrical energy storage device 13 and the radiator 14. In all embodiments, the radiator 14 is optional.

[0035] In Fig. Figures 1-3 also show inverters 16, with one inverter 16 shown for each electrical machine 12. As already described, the number of electrical machines 12 and thus also the number of inverters 16 can be changed as desired. Fig. 1, Fig. 2. The inverters 16 are located in the temperature control circuit 9 and thus in the cooling circuit or the temperature control circuit 9 coupled to the evaporator heat exchanger 7. This can be advantageous in order to cool the inverters 16 to the lowest possible temperature throughout. Alternatively, in Fig. Figure 3 shows that the inverters 16 can also be arranged in the temperature control circuit 8, which is coupled to the condenser heat exchanger 5. It is also possible to arrange this configuration in Fig. 2. To realize this, i.e., to integrate the inverters 16 into the temperature control circuit 8. The arrangement of the inverters 16 in the temperature control circuit 8 is also arbitrarily selectable, for example, upstream of the electrical energy storage device 13, downstream of the radiator 14, and the like.

[0036] In Fig. Figure 4 shows another alternative arrangement of the thermal management system 1. Optionally, it is shown here that the electrical energy storage device 13 is arranged downstream of the radiator 14, specifically in the flow direction between the radiator 14 and the condenser heat exchanger 5. This makes it possible to selectively dissipate heat into the environment via the radiator 14, thus cooling the temperature control fluid in the temperature control fluid circuit 8 before it is supplied to the electrical energy storage device 13. The operation of the radiator 14 can be controlled as needed, for example, depending on the temperature of the temperature control fluid in the temperature control fluid circuit 8. The embodiment in Fig. 4 can be combined with the embodiments described above, so that, for example, the arrangement of the inverters 16 or the electrical machines 12 can be changed accordingly.

[0037] Fig. Figure 5 shows an alternative embodiment of the thermal management system 1 in which the dielectric temperature control fluid is guided in the temperature control fluid circuit 9, which is coupled to the evaporator heat exchanger 7. As already described, in the embodiments according to Fig. 1-4 of the temperature control circuit 8 carries the dielectric temperature control fluid, and for example, the temperature control circuit 9 carries a temperature control fluid that includes water, specifically a water-glycol mixture. Therefore, in the explanations according to Fig. 5, Fig. 6. The dielectric temperature control fluid is carried in the temperature control fluid circuit 9. Accordingly, in the temperature control fluid circuit 8, Fig. 5 and Fig. 6. A temperature control fluid containing water, for example a water-glycol mixture, can be used. It is also possible, in principle, to use a dielectric temperature control fluid in all temperature control circuits 8, 9. If a dielectric temperature control fluid is used in one temperature control circuit 8, 9 and water or a water-containing temperature control fluid is used in the other temperature control circuit 8, 9, the advantages of both temperature control fluids can be utilized.

[0038] For example, as in Fig. Figure 5 shows that water is used in the temperature control circuit 8 to utilize its high heat capacity and high density for operating the heating device 11. In this embodiment, the electrical components 10 are completely relocated within the temperature control circuit 9, so that the use of water in the temperature control circuit 8 does not impair the electrical conductivity of the temperature control medium when flowing through the electrical components 10.

[0039] In the temperature control circuit 9, in which dielectric temperature control fluid is used in Fig. In section 5, all electrical devices 10 are arranged. For example, a sequence of corresponding thermal consumers is provided downstream of an air conditioning unit 17. The air conditioning unit 17, like the heating unit 11, is assigned to a passenger compartment or interior of the motor vehicle. By way of example, downstream of the air conditioning unit 17, the electric machine 12(s) and the inverter 16(s) are located. Following this, the dielectric temperature control fluid flows through the electrical energy storage device 13 and subsequently through further electrical components 18.

[0040] Fig. 6 depicts the execution according to Fig. 5 further, by providing an additional radiator 19. For example, the additional radiator 19 can dissipate heat from the dielectric temperature control fluid of the temperature control circuit 9 to the environment, which was absorbed by the upstream thermal consumers, for example, the air conditioning unit 17, the inverters 16, the electric machines 12. This ensures that the electrical energy storage device 13 receives the coolest possible temperature control fluid. As already described, in Fig. 5, Fig. 6. The arrangement of the individual thermal consumers can be changed as desired. For example, the electrical energy storage device 13 can also be integrated directly into the temperature control circuit 9 after the evaporator heat exchanger 7. The electric motors 12 and the inverters 16 can, for example, be integrated at the inlet of the evaporator heat exchanger 7.

[0041] The advantages, details, and features shown in the individual embodiments, particularly with regard to the arrangement of the individual thermal consumers, can be combined, interchanged, and transferred to one another as desired. The method described herein can be implemented in all its details with the thermal management system 1. Reference sign 1 Thermal management system 2 Heat pump 3 Refrigerant circuit 4 Compressor 5 condenser heat exchangers 6 Expansion valve 7 evaporator heat exchangers 8, 9 Temperature control circuit 10 electrical equipment 11 Heating system 12 electric machine 13 electrical energy storage 14 Radiator 15 pump 16 inverters 17 Air conditioning unit 18 electrical components 19 Radiator

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