Thermal management system for electric vehicle

Abstract

In an aspect the disclosure relates to a vehicular thermal management system that includes a refrigerant system, a cabin coolant system, a powertrain coolant system, a plurality of powertrain thermal loads, a condenser and an evaporator. The refrigerant system includes a compressor and an expansion valve. The cabin coolant system includes a cabin coolant pump and a heater core. The powertrain coolant system includes at least one powertrain coolant pump and a radiator. The condenser transfers heat from the refrigerant to the cabin coolant. The evaporator transfers heat from the powertrain coolant to the refrigerant and includes an evaporator heater to heat the refrigerant and the powertrain coolant in the evaporator.

Description

THERMAL MANAGEMENT SYSTEM FOR ELECTRIC VEHICLECROSS-REFERENCES TO RELATED APPLICATIONS

[0001] This application claims the benefit of US Provisional Application 63 / 680,837, filed August 8, 2024, the contents of which are incorporated herein by reference in their entirety.FIELD OF THE DISCLOSURE

[0002] This disclosure relates generally to the field of thermal management systems for use in electric vehicles, and more particularly for thermal management systems for use with high-pressure refrigerants in an electric vehicle.BACKGROUND

[0003] Thermal management systems in electric vehicles (EVs) are known to employ refrigerant systems, usually to assist at least in cooling the passenger cabins of the vehicles. The refrigerant used in such systems however, (e.g. R1234yf), may be restricted due to PFAS regulations. Propane, CO2 and other gases have been proposed as an alternative to R1234yf and other refrigerants. However, in order to operate successfully, propane would have to be pressurized to relatively high pressures. Furthermore, propane is flammable. Accordingly, to mitigate the risk to occupants of the vehicle, proposed thermal management systems remove the refrigerant system from near the passenger cabin, and a cabin coolant system has been introduced to coordinate with the refrigerant system in order to cool the cabin. Such proposed thermal management systems however, employ many components and devices and can be expensive. It would be beneficial to provide a thermal management system that reduces the number of components and devices, in order to simplify the thermal management system and to reduce its cost.SUMMARY

[0004] In an aspect, the disclosure relates to a thermal management system for an electric vehicle. The thermal management system includes a refrigerant system, a cabin coolant system, a powertrain coolant system, a plurality of powertrain thermal loads, a condenser and an evaporator. The refrigerant system is for transporting refrigerant, and includes a compressor and an expansion valve. The cabin coolant system is for transporting cabin coolant, and includes a cabin coolant pump and a heater core positioned to heat air passing therethrough into the passenger cabin. The powertrain coolant system for transporting powertrain coolant, and includes at least one powertrain coolant pump and a radiator. The plurality of powertrain thermal loads includes at least one of a traction motor and a battery pack, which are positioned to be thermally regulated by the powertrain coolant. The condenser includes a condenser coolant flow path and a condenser refrigerant flow path, which are positioned to transfer heat from the refrigerant in the condenser refrigerant flow path, to the cabin coolant in the condenser coolant flow path in order to carry out at least one of condensing the refrigerant and heating the cabin coolant. The compressor is upstream from the condenser, and the condenser is upstream from the expansion valve. The evaporator includes an evaporator coolant flow path and an evaporator refrigerant flow path, which are positioned to transfer heat from the powertrain coolant to the refrigerant in order to carry out at least one of evaporating the refrigerant and heating the powertrain coolant. The compressor is downstream from the evaporator, and the evaporator is downstream from the expansion valve. The evaporator further includes an evaporator heater that is positioned to heat the refrigerant in the evaporator and to heat the powertrain coolant in the evaporator.

[0005] The disclosure also relates to other innovations that are intended to be protected.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The foregoing and other aspects of the invention will be better appreciated with reference to the attached drawings, as follows:

[0007] Figure 1 is a schematic view of a thermal management system for an electric vehicle, in accordance with the prior art.

[0008] Figure 2 is a schematic view of a thermal management system for an electric vehicle, in accordance with an embodiment of the present disclosure.

[0009] Figure 3 is a side elevation view of an electric vehicle incorporating the thermal management system shown in Figure 2.

[0010] Figure 4 is a partially exploded perspective view of an evaporator shown in Figure 2.

[0011] Figure 5 is a schematic view of the thermal management system shown in Figure 2, operated in a cabin heating boost mode.

[0012] Figure 6 is a schematic view of a thermal management system shown in Figure 2, operated in a cabin and battery heating boost mode.

[0013] Figure 7 is a schematic view of a thermal management system shown in Figure 2, operated in a cabin and battery heating boost mode.

[0014] Figure 8 is a schematic view of a thermal management system shown in Figure 2, operated in a cabin heating heat-scavenge mode.

[0015] Figure 9 is a schematic view of a thermal management system shown in Figure 2, operated in a cabin and powertrain cooling mode.

[0016] Figure 10 is a schematic view of a thermal management system shown in Figure 2, including an additional cabin coolant heater.DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0017] INTRODUCTORY STATEMENTS

[0018] For simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the Figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiment or embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein may be practiced without these specific details. In other instances, well- known methods, procedures and components have not been described in detail so as not to obscure the embodiments described herein. It should be understood at the outset that, although exemplary embodiments are illustrated in the figures and described below, the principles of the present disclosure may be implemented using any number of techniques, whether currently known or not. The present disclosure should in no way be limited to the exemplary implementations and techniques illustrated in the drawings and described below.

[0019] The terms ‘comprising’ and ‘including’ and their various conjugations (e.g. ‘comprises’) will be understood to be inclusive and open-ended, and not exclusive. This means that if an element A includes or comprises an element B, it will be understood that element A could include or comprise other elements in addition to including or comprising element B. The term ‘having’ and its various conjugations are also to be understood as being open-ended in the same way as ‘comprising’ and ‘including’. These terms are not to be interpreted to exclude the presence of other features, steps or components.

[0020] As used herein, the terms “about” and “approximately” are meant to cover variations that may exist in the upper and lower limits of the ranges of values, such as variations in properties, parameters, and dimensions.

[0021] Various terms used throughout the present description may be read and understood as follows, unless the context indicates otherwise: "or" as used throughout is inclusive, as though written "and / or"; singular articles and pronouns as used throughout include their plural forms, and vice versa; similarly, gendered pronouns include theircounterpart pronouns such that pronouns should not be understood as limiting anything described herein to use, implementation, performance, etc. by a single gender; "exemplary" should be understood as "illustrative" or "exemplifying" and not necessarily as "preferred" over other embodiments. Further definitions for terms may be set out herein; these may apply to prior and subsequent instances of those terms, as will be understood from a reading of the present description. It will also be noted that the use of the term "a" or "an" will be understood to denote "at least one" in all instances unless explicitly stated otherwise or unless it would be understood to be obvious that it must mean "one".

[0022] Modifications, additions, or omissions may be made to the systems, apparatuses, and methods described herein without departing from the scope of the disclosure. For example, the components of the systems and apparatuses may be integrated or separated. Moreover, the operations of the systems and apparatuses disclosed herein may be performed by more, fewer, or other components and the methods described may include more, fewer, or other steps. Additionally, steps may be performed in any suitable order. As used in this document, "each" refers to each member of a set or each member of a subset of a set.

[0023] As used in this document, "attached" in describing the relationship between two connected parts includes the case in which the two connected parts are "directly attached" with the two connected parts being in contact with each other, and the case in which the connected parts are "indirectly attached" and not in contact with each other, but connected by one or more intervening other part(s) between.

[0024] As used in this document, terms describing relative positions of elements such as ‘top’, ‘upper’, ‘bottom’, ‘lower’, or other analogous terms will be understood to refer to the placement of the described element during use of the apparatus of which it is a part unless the context would make it clear that it is otherwise. It will be understood that the aforementioned placement of an element, for example, can still be considered its placement even when the object that it is a part of is lying in some position other than the position in which it will be used. As an example, if reference is made to a device having an upper member, it will be understood that the upper member is being described ashaving an upper position when the device that it is a part of is in use or is in position for use, unless the context would make it clear that it is otherwise. Further to this example, it will be understood that the aforementioned upper member of the object can still be considered its upper member even when the object is lying on its side, for storage, or for transport, or for some other reason.

[0025] "Memory" refers to a non-transitory tangible computer-readable medium for storing information (e.g., data or data structures) in a format readable by a processor, and / or instructions (e.g., computer code or software programs or modules) that are readable and executable by a processor to implement an algorithm. The term "memory" includes a single device or a plurality of physically discrete, operatively connected devices despite use of the term in the singular. Non-limiting types of memory include solid-state semiconductor, optical, magnetic, and magneto-optical computer readable media. Examples of memory technologies include optical discs such as compact discs (CD- ROMs) and digital versatile discs (DVDs), magnetic media such as floppy disks, magnetic tapes or cassettes, and solid state semiconductor random access memory (RAM) devices, read-only memory (ROM) devices, electrically erasable programmable read-only memory (EEPROM) devices, flash memory devices, memory chips and combinations of the foregoing. Memory may be non-volatile or volatile. Memory may be physically attached to a processor, or remote from a processor. Memory may be removable or nonremovable from a system including a processor. Memory may be operatively connected to a processor in such a way as to be accessible by a processor. Instructions stored by a memory may be based on a plurality of programming and / or markup languages known in the art, with non-limiting examples including the C, C++, C#, Python ™, MATLAB ™, Java ™, JavaScript ™, Perl ™, PHP ™, SQL ™, Visual Basic ™, Hypertext Markup Language (HTML), Extensible Markup Language (XML), and combinations of the foregoing. Instructions stored by a memory may also be implemented by configuration settings for a fixed-function device, gate array or programmable logic device.

[0026] "Processor" refers to one or more electronic hardware devices that is / are capable of reading and executing instructions stored on a memory to perform operations on data, which may be stored on a memory or provided in a data signal. The term"processor" includes a single device or a plurality of physically discrete, operatively connected devices despite use of the term in the singular. The plurality of processors may be arrayed or distributed. Non-limiting examples of processors include integrated circuit semiconductor devices and / or processing circuit devices referred to as computers, servers or terminals having single or multi-processor architectures, microprocessors, microcontrollers, microcontroller units (MCU), central processing units (CPU), field- programmable gate arrays (FPGA), application specific circuits (ASIC), digital signal processors, and combinations of the foregoing.

[0027] Any method, application or module herein described may be implemented using computer readable / executable instructions that may be stored or otherwise held by a memory, and executed by a processor. Aspects of the present disclosure may be described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the disclosure. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor, such that the processor, and a memory storing the instructions, which execute via the processor, collectively constitute a machine for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0028] The flowcharts and functional block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also benoted that each block of the block diagrams and / or flowchart illustration, and combinations of blocks in the block diagrams and / or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

[0029] The embodiments of the disclosures described herein are exemplary (e.g., in terms of materials, shapes, dimensions, and constructional details) and do not limit by the claims appended hereto and any amendments made thereto. Persons skilled in the art will appreciate that there are yet more alternative implementations and modifications possible, and that the following examples are only illustrations of one or more implementations. The scope of the disclosure, therefore, is only to be limited by the claims appended hereto and any amendments made thereto.

[0030] DESCRIPTION OF THERMAL MANAGEMENT SYSTEM OF PRIOR ART

[0031] Reference is made to Figure 1 , which shows schematic diagram of a thermal management system 200 for use with an electric vehicle, in accordance with the prior art. It will be noted that the thermal management system 10 shown in Figure 1 has been simplified in the sense that some components that may be present have been omitted here for simplicity.

[0032] The thermal management system 200 includes a refrigerant system 202 for transporting refrigerant, a cabin coolant system 204 for transporting cabin coolant and a powertrain coolant system 206 for transporting powertrain coolant. The refrigerant system 202 includes among other things, a compressor 208, a first expansion valve 210, a second expansion valve 212, and a cabin evaporator 214 positioned to cool air passing therethrough into the passenger cabin of the electric vehicle.

[0033] The cabin coolant system 204 includes a cabin coolant pump 216 and a heater core 218 positioned to heat air passing therethrough into the passenger cabin of the electric vehicle.

[0034] The powertrain coolant system 106 includes a powertrain coolant pump 220 and a powertrain coolant radiator 222.

[0035] The thermal management system 200 further includes a condenser 224 that includes a condenser coolant flow path and a condenser refrigerant flow path, which are positioned to transfer heat from the refrigerant in the condenser refrigerant flow path, to the coolant in the condenser coolant flow path in order to carry out at least one of condensing the refrigerant and heating the cabin coolant.

[0036] The cabin coolant system 204 further includes a cabin coolant heater 226, which is used to heat the cabin coolant, in order to heat the passenger cabin, during periods in which insufficient heat is being provided by the condenser 224.

[0037] The thermal management system 200 further includes a chiller 228, which is downstream from the first expansion valve 210 and upstream from the compressor 208. The chiller 228 receives powertrain coolant from the powertrain coolant system 206 and uses the powertrain coolant to heat refrigerant in the chiller 228 in order to evaporate the refrigerant.

[0038] The powertrain coolant system 206 transports powertrain coolant to one or more thermal loads, such as the power electronics for the traction motor of the electric vehicle, and the battery pack of the electric vehicle. The powertrain coolant may be used to heat or cool the battery pack and to cool the power electronics. In order to heat the battery pack, the powertrain coolant system 206 may further include a powertrain coolant heater 230. The powertrain coolant radiator 222 is provided to cool the powertrain coolant when it is desired to shed excess heat in the powertrain coolant.

[0039] The cabin coolant system 204 further include a cabin coolant radiator 232 that can be used to cool the cabin coolant during periods when the cabin coolant is being heated via the condenser 224, and there is no other need for the heat contained in the cabin coolant (e.g. to heat the passenger cabin).

[0040] The thermal management system 200 further includes a cabin coolant to powertrain coolant heat exchanger 234 which is used to transfer heat between the cabin coolant and the powertrain coolant, based on need.

[0041] DESCRIPTION OF THERMAL MANAGEMENT SYSTEM AND VEHICLEOF THE PRESENT DISCLOSURE

[0042] Reference is made to Figure 2, which shows a schematic diagram of a thermal management system 10 for use with an electric vehicle 12 shown in Figure 3. It will be noted that the thermal management system 10 shown in Figure 1 has been simplified in the sense that some components that may be present in the thermal management system 10, have been omitted here for simplicity, but will be understood by one skilled in the art to be provided as appropriate.

[0043] Referring to Figure 3, the electric vehicle 12 is shown as an automobile, but it could alternatively be an SUV, a light-duty truck, a heavy-duty truck, an off-road vehicle, a vehicle used in construction, an aircraft, or any other suitable type of vehicle. The electric vehicle 12 includes a plurality of thermal loads, including for example, a traction motor 13 and an energy source 14. The traction motor 13, as used herein, includes any associated power electronics. The traction motor 13 is operatively connected to one or more wheels, shown at 16, for driving the one or more wheels 16. The energy source 14 may be any suitable energy source. For example, in some embodiments, the energy source 14 may be a battery pack 15, as shown.

[0044] The electric vehicle 12 may be any type of vehicle that employs a traction motor 13 and an energy source 14 for supplying power to the traction motor 13. Furthermore, the electric vehicle 12 may contain only a traction motor (which is intended also to include containing more than one traction motor) for driving the one or more wheels 16, or optionally, it may additionally contain an internal combustion engine, such as a range extender engine to assist in recharging the energy source 14 when the energy source 14 at or near depletion, and / or for assisting in driving the one or more wheels 16.

[0045] In some embodiments the battery pack 15 may be the sole source of power for the traction motor 13 (i.e. the battery pack 15 may make up the only source of power in the energy source 14). In other embodiments, the energy source 14 for the electric vehicle 12 may include, for example, a fuel-cell stack (not shown), in addition to the battery pack 15. In the embodiment shown herein, the energy source 14 is the battery pack 15 only.

[0046] The electric vehicle includes a passenger cabin 20.

[0047] In Figure 3, the electric vehicle 12 is shown plugged in to a charging station19.

[0048] The thermal management system 10 shown in Figure 2 includes a refrigerant system 22 for transporting a refrigerant, a cabin coolant system 24 for transporting a cabin coolant and a powertrain coolant system 26 for transporting powertrain coolant. The refrigerant system 22 includes a compressor 28, and an expansion valve 30.

[0049] The lines used to represent refrigerant conduits are shown as dashed lines in Figure 2 (and in Figures 5-8), and the lines used to represent coolant conduits (whether for transporting powertrain coolant or for transporting cabin coolant) are shown as solid lines.

[0050] The cabin coolant system 24 includes a cabin coolant pump 32 and a heater core 34 positioned to heat air passing therethrough into the passenger cabin of the electric vehicle 12.

[0051] The powertrain coolant system 26 includes a powertrain coolant pump 36 and a powertrain coolant radiator 38.

[0052] The thermal management system 10 further includes a condenser 40 that includes a condenser coolant flow path 42 and a condenser refrigerant flow path 44, which are positioned to transfer heat from the refrigerant in the condenser refrigerant flow path 42, to the coolant in the condenser coolant flow path 44 in order to carry out at least one of condensing the refrigerant and heating the cabin coolant. The compressor 28 is upstream from the condenser, and the condenser is upstream from the expansion valve 30.

[0053] The thermal management system 10 further includes an evaporator 46, that includes an evaporator coolant flow path 48 and an evaporator refrigerant flow path 50, which are positioned to transfer heat from the powertrain coolant to the refrigerant in order to carry out at least one of evaporating the refrigerant and heating the powertrain coolant. The compressor 28 is downstream from the evaporator 46, and the evaporator 46 is downstream from the expansion valve 30.

[0054] The evaporator 46 further includes an evaporator heater 52 that is positioned to heat the refrigerant in the evaporator 46 and to heat the powertrain coolant in the evaporator 46.

[0055] The evaporator 46 may have any suitable construction. For example, referring to Figure 4, the evaporator 46 may include a plurality of flow plates 54, which may be made from any suitable material such as aluminum. Each flow plate 54 has a plurality of faces (e.g. a first face 56 and a second face 58) and a peripheral edge 60. The plurality of flow plates 54 are sealingly joined together (e.g. by brazing) such that the evaporator coolant flow path 48 and the evaporator refrigerant flow path 50 are positioned between mutually facing ones of the faces 56, 58 of adjacent ones of the plurality of flow plates 54. When joined together, the plurality of flow plates 52 together form a flow plate assembly 62 having a flow plate assembly peripheral edge face 64.

[0056] The evaporator heater 52 may extend along the flow plate assembly peripheral edge face 64. The evaporator heater 52 may be any suitable type of heater, such as, for example, an electric heater (e.g. a thin-film heater or a thick-film heater), an induction heater or any other suitable type of heater.

[0057] The evaporator 46 may be as shown and described in PCT patent publication W02023 / 060352 A1 , the contents of which are incorporated herein by reference in their entirety.

[0058] Referring to Figure 2, the powertrain coolant system 26 transports powertrain coolant to one or more thermal loads, such as the traction motor 13 (and specifically the power electronics for the traction motor 13) of the electric vehicle 12, and the battery pack 15 of the electric vehicle 12. The powertrain coolant may be used to cool the power electronics and to heat or cool the battery pack 15, as is described in further detail further below.

[0059] The evaporator 46 may be referred to as a powertrain system interface evaporator 46, and the expansion valve 30 may be referred to as a powertrain system interface expansion valve 30. The refrigerant system 22 may optionally include a cabin expansion valve 66 and a cabin evaporator 68 that is positioned to evaporate therefrigerant by the air passing over the cabin evaporator 68 and into the passenger cabin 20. The cabin evaporator 68 is shown far from the heater core 34 shown in Figure 2, however it will be understood that both of these devices may be positioned relatively close to the passenger cabin 20 of the electric vehicle 12.

[0060] Optionally, the cabin coolant system 24 and the powertrain coolant system 26 are fl uidical ly connected to one another so as to permit cabin coolant leaving the heater core 34 to pass through the radiator 38, and so as to permit powertrain coolant leaving the evaporator 46 to be transported into the cabin coolant system 24 to become cabin coolant and to pass through the heater core 34 to heat the heater core 34.

[0061] Optionally the powertrain coolant pump 36 may be referred to as a battery pack coolant pump 36, and the powertrain coolant system 26 may further include another powertrain coolant pump shown at 69, which may be referred to as a power electronics coolant pump 69. The powertrain coolant system 26 may be said to include at least one powertrain coolant pump.

[0062] The thermal management system 10 may further include a control system 70 including a memory 70a, a processor 70b, and a printed circuit board (PCB) 70c. The processor is operatively connected to the evaporator heater 52. The memory 70b contains instructions that are readable by the processor 70a to: operate the evaporator 46 in a secondary heat mode (Figures 5 and 6) in which the evaporator heater 52 is energized to heat and evaporate the refrigerant in the evaporator refrigerant flow path 50 so as to transfer heat from the refrigerant to the cabin coolant in the condenser 40 so as to heat the air passing through the heater core 34 and into the passenger cabin 20; and operate the evaporator 46 in a heat scavenging mode (Figures 7 and 8), based on at least one of an ambient air temperature, and a temperature of at least one of the powertrain thermal loads, so as to transfer heat from the powertrain coolant flow path 48 to heat and evaporate the refrigerant in the evaporator refrigerant flow path 50. In the heat scavenging mode, the evaporator heater 52 is deenergized. An ambient air temperature sensor is shown in Figure 2 at 72. A power electronics temperature sensor is shown at 74, and a battery pack temperature sensor is shown at 76. The power electronics temperature sensor 74 may have any suitable structure, such as a thermocouplepositioned in a suitable location in the power electronics, or alternatively two thermocouples, one placed to measure the temperature of the powertrain coolant immediately upstream from the power electronics, and one placed to measure the temperature of the powertrain coolant immediately downstream from the power electronics. Similarly, a battery pack temperature sensor 76 may have any suitable structure, such as a thermocouple positioned in a suitable location in the battery pack 15, or alternatively two thermocouples, one placed to measure the temperature of the powertrain coolant immediately upstream from the battery pack 15, and one placed to measure the temperature of the powertrain coolant immediately downstream from the battery pack 15. The ambient air temperature sensor 72, the power electronics temperature sensor 74, and the battery pack temperature sensor 76 may all be connected in any suitable way to the control system 70 such as by a wired connection or by a wireless connection to the PCB 70c.

[0063] The thermal management system 10 may further include a plurality of control valves shown at 78 that the control system 70 is operatively connected to, in order to direct powertrain coolant flow and cabin coolant flow to various locations. In the figures, the control valves 78 have three ports, however they may have any other suitable number of ports. In the figures any of the ports of the control valves 78 that are shown in solid black are open and therefore permit coolant flow therethrough, and any ports that are shown as a black outline are closed and therefore prevent coolant flow therethrough.

[0064] DESCRIPTION OF OPERATION OF THERMAL MANAGEMENT SYSTEM IN VARIOUS CONDITIONS

[0065] Figures 5-9 illustrate the operation of the thermal management system 10 under various conditions. Figure 5 illustrates the operation of the thermal management system 10 when being called upon to heat the passenger cabin 20 when the ambient air temperature is below a selected ambient air temperature such as, for example, -10 degrees Celsius (or any other suitable temperature). The thermal management system 10 may be said to be controlled by the control system 70 to operate in a cabin heating boost mode. Alternatively worded, the memory 70b may contain instructions that are readable by the processor to operate the thermal management system 10 in a cabinheating boost mode. In this mode, the battery pack 15 is not being heated by the thermal management system 10. This may be because the electric vehicle 12 is parked and is not being driven, and may optionally be ‘on-plug’ (i.e. plugged into the charging station 18).

[0066] In this mode, the compressor 28 may be driven by the control system 70 to drive refrigerant flow through the refrigerant system 22. The evaporator heater 52 is energized up to a selected level (e.g. more than 5 kW) so as to heat and evaporate refrigerant in the evaporator refrigerant flow path 50. The at least one powertrain coolant pump (e.g. the powertrain coolant pumps 36 and 69) is turned off. The cabin coolant pump 32 is on to drive cabin coolant through the cabin coolant system 24. The cabin expansion valve 66 (if provided) is closed so as to prevent refrigerant flow therethrough. The powertrain system interface expansion valve 30 is open so as to permit refrigerant flow through the powertrain system interface evaporator 46. The control valves 78 are positioned to direct cabin coolant to not leave (remain in) the cabin coolant system 24. In the condenser 40 heat is transferred from the refrigerant to the cabin coolant, which in turn transfers heat to an air flow passing through the heater core 34 so as to heat the passenger cabin 20.

[0067] Figure 6 illustrates the operation of the thermal management system 10 when being called upon to heat the passenger cabin 20 and also to heat the battery pack 15 when the ambient air temperature is below a selected ambient air temperature such as, for example, -10 degrees Celsius (or any other suitable temperature). The thermal management system 10 may be said to be controlled by the control system 70 to operate in a cabin and battery heating boost mode. Alternatively worded, the memory 70b may contain instructions that are readable by the processor to operate the thermal management system 10 in a cabin and battery heating boost mode. This mode may be used where a passenger requests heating of the passenger cabin 20 while the electric vehicle 12 is being driven.

[0068] In this mode, the compressor 28 may be driven by the control system 70 to drive refrigerant flow through the refrigerant system 22. The evaporator heater 52 is energized up to a selected level (e.g. 10 kW) so as to heat and evaporate the refrigerantin the evaporator refrigerant flow path 50 and so as to heat the powertrain coolant in the evaporator coolant flow path 48. The at least one powertrain coolant pump is operated to drive powertrain coolant through the battery pack 15. In this example, the powertrain coolant pump 36 is on and the powertrain coolant pump 69 is off. The cabin coolant pump 32 is on to drive cabin coolant through the cabin coolant system 24. The cabin expansion valve 66 (if provided) is closed so as to prevent refrigerant flow through the cabin evaporator 68 (if provided). The powertrain system interface expansion valve 30 is open so as to permit refrigerant flow through the powertrain system interface evaporator 46. The control valves 78 are positioned to direct cabin coolant to leave the cabin coolant system 24 and to enter the powertrain coolant system 26 (so as to become powertrain coolant), to direct powertrain coolant to split in flow such that a first portion thereof leaves the powertrain coolant system 26 and enters the cabin coolant system 24 to become cabin coolant, and such that a second portion thereof passes through the battery pack 15, and to prevent powertrain coolant from flowing through the power electronics and through the radiator 38. In the condenser 40 heat is transferred from the refrigerant to the cabin coolant, which in turn transfers heat to an air flow passing through the heater core 34 so as to heat the passenger cabin 20. Furthermore, heat is transferred from the powertrain coolant into the battery pack 15 to heat the battery pack 15 so as to bring the battery pack 15 up to a suitable temperature for the battery pack 15 to be able to efficiently supply power to the traction motor 13.

[0069] Figure 7 illustrates another type of operation of the thermal management system 10 when being called upon to heat the passenger cabin 20 and also to heat the battery pack 15 when the ambient air temperature is below a selected ambient air temperature such as, for example, -10 degrees Celsius (or any other suitable temperature). The thermal management system 10 may again be said to be controlled by the control system 70 to operate in a cabin and battery heating boost mode. Alternatively worded, the memory 70b may again be said to contain instructions that are readable by the processor to operate the thermal management system 10 in a cabin and battery heating boost mode. Optionally, the cabin and battery heating boost mode illustrated in Figure 6 may be referred to as a first cabin and battery heating boost modeand the cabin and battery heating boost mode illustrated in Figure 7 may be referred to as a second cabin and battery heating boost mode.

[0070] In this mode, the compressor 28 may be driven by the control system 70 to drive refrigerant flow through the refrigerant system 22. The evaporator heater 52 is energized up to a selected level (e.g. 10 kW) so as to heat and evaporate the refrigerant in the evaporator refrigerant flow path 50 and so as to heat the powertrain coolant in the evaporator coolant flow path 48. The at least one powertrain coolant pump is operated to drive powertrain coolant through the battery pack 15. In this example, the powertrain coolant pump 32 is on and the powertrain coolant pump 69 is off. The cabin coolant pump 32 is on to drive cabin coolant through the cabin coolant system 24. The cabin expansion valve 66 (if provided) is closed so as to prevent refrigerant flow through the cabin evaporator 68 (if provided). The powertrain system interface expansion valve 30 is open so as to permit refrigerant flow through the powertrain system interface evaporator 46. The control valves 78 are positioned to direct powertrain coolant to pass through the battery pack 15 so as to heat the battery pack, to prevent powertrain coolant from flowing through the power electronics and through the radiator 38, to prevent cabin coolant from leaving the cabin coolant system 24, and to prevent powertrain coolant from leaving the powertrain coolant system 26. In the condenser 40 heat is transferred from the refrigerant to the cabin coolant, which in turn transfers heat to an air flow passing through the heater core 34 so as to heat the passenger cabin 20. Furthermore, heat is transferred from the powertrain coolant into the battery pack 15 to heat the battery pack 15 so as to bring the battery pack 15 up to a suitable temperature for the battery pack 15 to be able to efficiently supply power to the traction motor 13.

[0071] Figure 8 illustrates another type of operation of the thermal management system 10 when being called upon to heat the passenger cabin 20, not to heat the battery pack 15, and to cool the power electronics when the ambient air temperature is above a selected ambient air temperature such as, for example, -10 degrees Celsius (or any other suitable temperature). The thermal management system 10 may be said to be controlled by the control system 70 to operate in a cabin heating heat-scavenge mode. Alternativelyworded, the memory 70b may contain instructions that are readable by the processor to operate the thermal management system 10 in a cabin heating heat-scavenge mode.

[0072] In this mode, the compressor 28 may be driven by the control system 70 to drive refrigerant flow through the refrigerant system 22. The evaporator heater 52 is off. The at least one powertrain coolant pump is operated so as to drive powertrain coolant through the radiator 38 and the power electronics to cool the power electronics, and to prevent powertrain coolant through the battery pack 15. In this example, the powertrain coolant pump 69 is on and the powertrain coolant pump 36 is off. The cabin coolant pump 32 is on to drive cabin coolant through the cabin coolant system 24. The cabin expansion valve 66 (if provided) is closed so as to prevent refrigerant flow through the cabin evaporator 68 (if provided). The powertrain system interface expansion valve 30 is open so as to permit refrigerant flow through the powertrain system interface evaporator 46. The control valves 78 are positioned to prevent powertrain coolant flow through the battery pack 15, to permit powertrain coolant flow through the radiator 38 to cool down and then through the power electronics to cool the power electronics, to prevent cabin coolant from leaving the cabin coolant system 24, and to prevent powertrain coolant from leaving the powertrain coolant system 26. Heat accumulated in the powertrain coolant from the power electronics is transferred into the refrigerant in the powertrain system interface evaporator 46 to evaporate the refrigerant. In the condenser 40 heat is transferred from the refrigerant to the cabin coolant, which in turn transfers heat to an air flow passing through the heater core 34 so as to heat the passenger cabin 20.

[0073] Figure 9 illustrates another type of operation of the thermal management system 10 when being called upon to cool the passenger cabin 20, the battery pack 15, and the power electronics. The thermal management system 10 may be said to be controlled by the control system 70 to operate in a cabin and powertrain cooling mode. Alternatively worded, the memory 70b may contain instructions that are readable by the processor to operate the thermal management system 10 in a cabin and powertrain cooling mode.

[0074] In this mode, the compressor 28 may be driven by the control system 70 to drive refrigerant flow through the refrigerant system 22. The evaporator heater 52 is off.The at least one powertrain coolant pump is on so as to drive powertrain coolant through the radiator 38 and the power electronics to cool the power electronics, and to drive powertrain coolant flow through the battery pack 15 to cool the battery pack 15. In this example, both the powertrain coolant pump 69 and the powertrain coolant pump 36 are on. The cabin coolant pump 32 is on to drive cabin coolant through the cabin coolant system 24. The cabin expansion valve 66 is open so as to permit refrigerant flow through the cabin evaporator 68. The powertrain system interface expansion valve 30 is open so as to permit refrigerant flow through the powertrain system interface evaporator 46. Thus, refrigerant flow is split between the cabin evaporator 68 and the powertrain system interface evaporator 46, whereby the cabin evaporator 68 cools an air flow passing therepast into the passenger cabin 20. The control valves 78 are positioned to direct powertrain coolant flow through the powertrain system interface evaporator 46 to cool the powertrain coolant and then through the battery pack 15 to cool the battery pack 15, and also to direct cabin coolant to leave the cabin coolant system 24 and to enter the powertrain coolant system 26 (so as to become powertrain coolant), to then to flow through the radiator 38 to cool down, through the power electronics to cool the power electronics, and to then flow back into the cabin coolant system 24 (so as to become cabin coolant). In the condenser 40 heat is transferred from the refrigerant to the cabin coolant. The cabin coolant may pass through the heater core 34 but air flow is not driven across the heater core 34 and / or may be blocked from entering the passenger cabin 20 from the heater core 34, so as to avoid heating the passenger cabin 20.

[0075] Figure 10 illustrates an alternative embodiment of the thermal management system 10 in which the cabin coolant system 24 includes an optional cabin coolant heater 80, which can be used to assist in heating the cabin coolant faster than just using the powertrain system interface evaporator 46 with or without the evaporator heater 52. The cabin coolant heater 80 may be any suitable type of heater such as a thin-film heater or a thick-film heater that is mounted on the exterior surface of a portion of the conduit that is part of the cabin coolant system 24. The cabin coolant heater 80 may be positioned downstream of the condenser 36 and upstream from the heater core 34. The cabin coolant heater 80 may have any suitable amount of power, such as, for example, 3 kW.

[0076] While the description contained herein constitutes a plurality of embodiments of the present invention, it will be appreciated that the present invention is susceptible to further modification and change without departing from the fair meaning of the accompanying claims.

Claims

CLAIMSWhat is claimed is:

1. A thermal management system for an electric vehicle having a passenger cabin, comprising: a refrigerant system for transporting refrigerant, and which includes a compressor and an expansion valve; a cabin coolant system for transporting cabin coolant, and which includes a cabin coolant pump and a heater core positioned to heat air passing therethrough into the passenger cabin; a powertrain coolant system for transporting powertrain coolant, and which includes at least one powertrain coolant pump and a radiator; a plurality of powertrain thermal loads including at least one of a traction motor and a battery pack, which are positioned to be thermally regulated by the powertrain coolant; a condenser that includes a condenser coolant flow path and a condenser refrigerant flow path, which are positioned to transfer heat from the refrigerant in the condenser refrigerant flow path, to the cabin coolant in the condenser coolant flow path in order to carry out at least one of condensing the refrigerant and heating the cabin coolant, wherein the compressor is upstream from the condenser, and the condenser is upstream from the expansion valve; and an evaporator that includes an evaporator coolant flow path and an evaporator refrigerant flow path, which are positioned to transfer heat from the powertrain coolant to the refrigerant in order to carry out at least one of evaporating the refrigerant and heating the powertrain coolant, wherein the compressor is downstream from the evaporator, and the evaporator is downstream from the expansion valve, wherein the evaporator further includes an evaporator heater that is positioned to heat the refrigerant in the evaporator and to heat the powertrain coolant in the evaporator.

2. The thermal management system as claimed in claim 1 , further comprising a control system including a memory and a processor, wherein the processor is operatively connected to the evaporator heater, and the memory contains instructions that are readable by the processor to: operate the evaporator in a secondary heat mode in which the evaporator heater is energized to heat and evaporate the refrigerant in the evaporator refrigerant flow path so as to transfer heat from the refrigerant to the cabin coolant in the condenser so as to heat the air passing through the heater core and into the passenger cabin, and operate the evaporator in a heat scavenging mode, based on at least one of an ambient air temperature, and a temperature of at least one of the powertrain thermal loads, so as to transfer heat from the powertrain coolant in the powertrain coolant flow path to the refrigerant in the evaporator refrigerant flow path to heat and evaporate the refrigerant in the evaporator refrigerant flow path, wherein, in the heat scavenging mode, the evaporator heater is deenergized.

3. The thermal management system as claimed in claim 1 , wherein the evaporator is a powertrain system interface evaporator, and the expansion valve is a powertrain system interface expansion valve, and wherein the refrigerant system further includes a cabin expansion valve and a cabin evaporator that is positioned to evaporate the refrigerant by the air passing over the cabin evaporator and into the passenger cabin.

4. The thermal management system as claimed in claim 1 , wherein the evaporator heater is an electric heater.

5. The thermal management system as claimed in claim 1 , wherein the cabin coolant system and the powertrain coolant system are fluidically connected to one another so as to permit cabin coolant leaving the heater core to pass through the radiator, and so as to permit powertrain coolant leaving the evaporator to be transported into the cabin coolant system to become cabin coolant and to pass through the heater core to heat the heater core.

6. The thermal management system as claimed in claim 1 , wherein the cabin coolant system includes a cabin coolant heater that is positioned upstream from the heater core, and is energizable by the control system to heat cabin coolant being transported to the heater core.

7. The thermal management system as claimed in claim 1 , wherein the thermal management system further includes a plurality of control valves that the control system is operatively connected to, in order to direct powertrain coolant flow and cabin coolant flow through the thermal management system, and wherein the memory contains instructions that are readable by the processor to operate the thermal management system in a cabin heating boost mode, in which the compressor drives the refrigerant to flow through the refrigerant system, the evaporator heater is energized to heat and evaporate the refrigerant in the evaporator refrigerant flow path, the at least one powertrain coolant pump is turned off to prevent coolant flow in the powertrain coolant system, the cabin coolant pump is on to drive cabin coolant through the cabin coolant system, the expansion valve is open so as to permit the refrigerant to flow through the evaporator, and the control valves are positioned to direct the cabin coolant to remain in the cabin coolant system, such that, in the condenser heat is transferred from the refrigerant to the cabin coolant, which in turn transfers heat to an air flow passing through the heater core so as to heat the passenger cabin.

8. The thermal management system as claimed in claim 1 , wherein the thermal management system further includes a plurality of control valves that the control system is operatively connected to, in order to direct powertrain coolant flow and cabin coolant flow through the thermal management system, and wherein the memory contains instructions that are readable by the processor to operate the thermal management system in a cabin and battery heating boost mode, in which the compressor drives the refrigerant to flow through the refrigerant system, the evaporator heater is energized up to heat and evaporate the refrigerant in the evaporator refrigerant flow path and to heat the powertrain coolant in the evaporator coolant flow path, the at least one powertrain coolant pump is operated to drive the powertrain coolantthrough the battery pack, the cabin coolant pump is on to drive cabin coolant through the cabin coolant system, the expansion valve is open so as to permit refrigerant flow through the evaporator, the control valves are positioned to direct the cabin coolant to leave the cabin coolant system and to enter the powertrain coolant system, to direct the powertrain coolant to split in flow such that a first portion thereof leaves the powertrain coolant system and enters the cabin coolant system, and such that a second portion thereof passes through the battery pack, and to prevent the powertrain coolant from flowing through the power electronics and through the radiator, such that, in the condenser heat is transferred from the refrigerant to the cabin coolant, which in turn transfers heat to an air flow passing through the heater core so as to heat the passenger cabin, and such that heat is transferred from the powertrain coolant into the battery pack to heat the battery pack.

9. The thermal management system as claimed in claim 1 , wherein the thermal management system further includes a plurality of control valves that the control system is operatively connected to, in order to direct powertrain coolant flow and cabin coolant flow through the thermal management system, and wherein the memory contains instructions that are readable by the processor to operate the thermal management system in a cabin and battery heating boost mode, in which the compressor drives the refrigerant to flow through the refrigerant system, the evaporator heater is energized to heat and evaporate the refrigerant in the evaporator refrigerant flow path and so as to heat the powertrain coolant in the evaporator coolant flow path, the at least one powertrain coolant pump is operated to drive the powertrain coolant through the battery pack, the cabin coolant pump is on to drive cabin coolant through the cabin coolant system, the expansion valve is open so as to permit refrigerant flow through the evaporator, the control valves are positioned to direct powertrain coolant to pass through the battery pack so as to heat the battery pack, to prevent powertrain coolant from flowing through the power electronics and through the radiator, to prevent cabin coolant from leaving the cabin coolant system, and to prevent powertrain coolant from leaving the powertrain coolant system, such that, in the condenser heat is transferred from the refrigerant to the cabin coolant, which in turn transfers heat to an airflow passing through the heater core so as to heat the passenger cabin, and heat is transferred from the powertrain coolant into the battery pack to heat the battery pack.

10. The thermal management system as claimed in claim 1 , wherein the thermal management system further includes a plurality of control valves that the control system is operatively connected to, in order to direct powertrain coolant flow and cabin coolant flow through the thermal management system, and wherein the memory contains instructions that are readable by the processor to operate the thermal management system in a cabin heating heat-scavenge mode, in which the compressor drives the refrigerant to flow through the refrigerant system, the evaporator heater is off, the at least one powertrain coolant pump is operated so as to drive the powertrain coolant through the radiator and the power electronics to cool the power electronics, and to prevent the powertrain coolant from flowing through the battery pack, the cabin coolant pump is on to drive the cabin coolant through the cabin coolant system, the expansion valve is open so as to permit refrigerant flow through the evaporator, the control valves are positioned to prevent powertrain coolant flow through the battery pack, to permit the powertrain coolant to flow through the radiator to cool down and then through the power electronics to cool the power electronics, to prevent the cabin coolant from leaving the cabin coolant system, and to prevent the powertrain coolant from leaving the powertrain coolant system, such that heat accumulated in the powertrain coolant from the power electronics is transferred into the refrigerant in the powertrain system interface evaporator to evaporate the refrigerant, and in the condenser heat is transferred from the refrigerant to the cabin coolant, which in turn transfers heat to an air flow passing through the heater core so as to heat the passenger cabin.

11. The thermal management system as claimed in claim 1 , wherein the thermal management system further includes a plurality of control valves that the control system is operatively connected to, in order to direct powertrain coolant flow and cabin coolant flow through the thermal management system, and wherein the memory contains instructions that are readable by the processor to operate the thermal management system in a cabin and powertrain cooling mode, inwhich the compressor drives the refrigerant to flow through the refrigerant system, the evaporator heater is off, the at least one powertrain coolant pump is on so as to drive powertrain coolant through the radiator and the power electronics to cool the power electronics, and to drive powertrain coolant flow through the battery pack to cool the battery pack, the cabin coolant pump is on to drive cabin coolant through the cabin coolant system, the cabin expansion valve is open so as to permit refrigerant flow through the cabin evaporator, the powertrain system interface expansion valve is open so as to permit refrigerant flow through the powertrain system interface evaporator, such that refrigerant flow is split between the cabin evaporator and the powertrain system interface evaporator such that the cabin evaporator cools an air flow passing therepast into the passenger cabin, the control valves are positioned to direct powertrain coolant flow through the powertrain system interface evaporator to cool the powertrain coolant and then through the battery pack to cool the battery pack, and also to direct cabin coolant to leave the cabin coolant system and to enter the powertrain coolant system, to then to flow through the radiator to cool down, through the power electronics to cool the power electronics, and to then flow back into the cabin coolant system, such that in the condenser heat is transferred from the refrigerant to the cabin coolant.

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