Electric vehicle thermal management system

Abstract

An electric vehicle thermal management system is described. The electric vehicle thermal management system includes a coolant circuit (102) configured to circulate coolant through components of an electric propulsion system (110), a refrigerant circuit (104) configured to circulate refrigerant and comprising a refrigerant compressor (158), and a liquid-cooled condenser (118) configured to thermally couple the coolant in the coolant circuit to the refrigerant in the refrigerant circuit, the liquid-cooled condenser arranged downstream of the electric propulsion system (110) in the coolant circuit and downstream of the refrigerant compressor in the refrigerant circuit.

Description

Electric Vehicle Thermal Management SystemRELATED APPLICATION[0001 j This application claims priority to U.S . Provisional Patent Application Serial No. 63 / 585,860, filed on September 27, 2023, entitled “Electric Vehicle Thermal Management System,” the entire disclosure of which is hereby incorporated by reference herein in its entirety.FIELD

[0002] The present description relates generally to a cooling system for an electric vehicle.BACKGROUND

[0003] Electric vehicles have gained popularity as a sustainable and environmentally friendly alternative to traditional internal combustion engine vehicles. Electric vehicles include an electric propulsion system, which includes one or more electric motors, power electronics, inverters, battery packs, and associated electrical systems. These components convert electrical energy from the battery pack into mechanical power to drive the vehicle.

[0004] While electric propulsion systems offer numerous environmental advantages, such as by reducing or eliminating tailpipe emissions, they generate substantial amounts of heat during operation. Excessive heat accumulation can lead to reduced efficiency, accelerated degradation, and diminished overall performance. Therefore, electric ivehicles include thermal management systems in order to manage thermal conditions within the electric propulsion system.SUMMARY

[0005] An electric vehicle thermal management system is described. The electric vehicle thermal management system may include a coolant circuit configured to circulate coolant through components of an electric propulsion system, a refrigerant circuit configured to circulate refrigerant and comprising a refrigerant compressor, and a liquid-cooled condenser configured to thermally couple the coolant in the coolant circuit to the refrigerant in the refrigerant circuit, the liquid-cooled condenser arranged downstream of the electric propulsion system in the coolant circuit and downstream of the refrigerant compressor in the refrigerant circuit.

[0006] It should be understood that the summary above is provided to introduce, in simplified form, a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The detailed description is described with reference to the accompanying figures. Entities represented in the figures are indicative of one or more entities, and thus,reference is made interchangeably to single or plural forms of the entities in the discussion.

[0008] FIG. 1 schematically shows an example implementation of a thermal management system of a vehicle.

[0009] FIGS. 2A-2C schematically show another example implementation of a thermal management system of a vehicle.

[0010] FIG. 3 shows a bar graph demonstrating an effect of incorporating a liquid- cooled condenser that thermally couples superheated refrigerant vapor with heated coolant on a cooling capacity of a refrigerant circuit.

[0011] FIG. 4 shows a bar graph demonstrating an effect of incorporating a liquid- cooled condenser that thermally couples superheated refrigerant vapor with heated coolant on an efficiency of a refrigerant circuit.

[0012] FIG. 5 is a flow diagram depicting an algorithm as a step-by-step procedure in an example of implementing an electric vehicle thermal management system having a liquid-cooled condenser arranged to thermally couple superheated refrigerant vapor with heated coolant.

[0013] FIG. 6 is a flow diagram depicting an algorithm as a step-by-step procedure in an example of implementing an electric vehicle thermal management system that includes a valve for controlling flow to an air condenser.

[0014] FIG. 7 shows a summary table of example operating modes of an electric vehicle thermal management system that utilize a liquid-cooled condenser to increase a cooling capacity and efficiency of a refrigeration circuit.

[0015] FIG. 8 is a top view schematically illustrating an example configuration of a vehicle in which the techniques described herein may be implemented.DETAILED DESCRIPTIONOverview

[0016] The following description relates to systems and methods for an electric vehicle thermal management system. The electric vehicle thermal management system regulates thermal conditions within an electric propulsion system and also provides cabin cooling. However, providing adequate cooling may be challenging, particularly at higher ambient temperatures. For example, at higher ambient temperatures, the increased heat load is passed to a refrigerant circuit from a battery circuit through a chiller. By way of example, the chiller may use the refrigerant as a working fluid to receive heat transfer from the coolant flowing through the battery circuit. Due to the heat transfer from the coolant to the refrigerant at the chiller, the temperature of the coolant decreases. In contrast, as the refrigerant passes through the chiller, the temperature of the refrigerant increases, causing the refrigerant to boil.

[0017] A cooling capacity (e.g., refrigerant capacity) of the refrigerant circuit is dictated, at least in part, by a size of an air condenser used to reject heat from the refrigerant and condense the refrigerant to its liquid form. That is, increasing the air condenser size increases the overall cooling capacity of the refrigerant circuit, enabling the refrigerant circuit to effectively provide cooling to the battery circuit as well as to additional vehicle systems (e.g., a cabin cooling system) at higher ambient temperatures.

[0018] However, increasing the size of the air condenser is challenging due to packaging space constraints and airflow limitations. For instance, larger air condensers have higher airflow rate demands in order to achieve effective heat transfer to ambient air, but airflow in an underhood compartment where the air condenser is located may be limited. Increasing the size of the air condenser also results in a higher pressure drop and temperature rise of air across the air condenser, which may result in reduced efficiency, a higher incidence of degradation, and overloading of a compressor of the refrigerant circuit. Moreover, increasing the air condenser size may result in a radiator positioned proximate to the air condenser having inefficient heat transfer due to the radiator also rejecting heat to the ambient air.

[0019] The inventors herein have recognized the above issues and have engineered a solution to at least partially address them. In one example, an electric vehicle thermal management system is provided, comprising a coolant circuit configured to circulate coolant through components of an electric propulsion system, a refrigerant circuit configured to circulate refrigerant and comprising a refrigerant compressor, and a liquid-cooled condenser configured to thermally couple the coolant in the coolant circuit to the refrigerant in the refrigerant circuit, the liquid-cooled condenser arranged downstream of the electric propulsion system in the coolant circuit and downstream of the refrigerant compressor in the refrigerant circuit. By including the liquid-cooled condenser, at least part of the heat load is transferred from the refrigerant to the coolant, thus reducing the heat load of the refrigerant received at the air condenser and increasing a cooling capacity of the refrigerant circuit without increasing the size of the air condenser.

[0020] For example, the components of the electric propulsion system are fluidically coupled to a coolant inlet of the liquid-cooled condenser. The coolant inlet is configured to receive coolant that has been heated by the components of the electric propulsion system. A refrigerant inlet of the liquid-cooled condenser is fluidically coupled to an outlet of the refrigerant compressor. The refrigerant inlet is configured to receive superheated refrigerant vapor from the refrigerant compressor. The superheated refrigerant vapor is hotter than the coolant received at the coolant inlet. As such, the liquid-cooled condenser facilitates heat transfer from the superheated refrigerant vapor to the coolant, which reduces a temperature of the refrigerant and increases a temperature of the coolant. Due to the temperature of the refrigerant decreasing, the refrigerant at least partially condenses to a liquid form. By thermally coupling the coolant circuit and the refrigerant circuit via the liquid-cooled condenser, the coolant circuit augments a cooling capacity of the refrigerant circuit by diverting part of the heat load of the refrigerant circuit to the coolant circuit.

[0021] In at least one implementation, the liquid-cooled condenser is coupled in series with an air condenser. In this scenario, an inlet of the air condenser is fluidically coupled to a refrigerant outlet of the liquid-cooled condenser. As such, the air condenser receives the at least partially condensed refrigerant and further condenses it to the liquid form by facilitating heat transfer from the refrigerant to ambient air. By arranging the liquid-cooled condenser in series with the air condenser and upstream of the air condenser, the cooling capacity of the refrigerant circuit is increased beyond a capacity of the air condenser and without increasing the size of the air condenser.Moreover, by reducing an amount of heat discharged to the ambient air at the aircondenser, a temperature increase of ambient air across the air condenser is decreased, thus increasing an efficiency of the air condenser and downstream radiator stacks.

[0022] In one or more variations, the liquid-cooled condenser is coupled in parallel with the air condenser. In this scenario, a valve is arranged at the outlet of the refrigerant compressor. The valve is adjustable to block or enable flow between the refrigerant compressor and the air condenser. By way of example, the valve is adjustable between a first position that enables flow from the refrigerant compressor to both of the liquid- cooled condenser and the air condenser and a second position that enables flow from the refrigerant compressor to the liquid-cooled condenser while blocking flow from the refrigerant compressor to the air condenser. The valve may be adjusted (e.g., by a vehicle controller) between the first position and the second position based on a heat load of the refrigerant circuit. For example, the valve may be operated in the first position when the heat load of the refrigerant circuit is greater than or equal to a threshold, such as when both vehicle cabin cooling and battery cooling are requested via the refrigerant circuit. In contrast, the valve may be operated in the second position when the heat load is less than the threshold, such as when the vehicle cabin cooling or the battery cooling is requested.

[0023] Accordingly, when the valve is in the first position, a first portion of the superheated refrigerant vapor flows from the refrigerant compressor to the liquid-cooled condenser, and a second, remaining portion of the superheated refrigerant vapor flows from the refrigerant compressor to the air condenser. By dividing the superheated refrigerant vapor between the liquid-cooled condenser and the air condenser, the coolant circuit receives a portion of the heat load from the refrigerant circuit via heat exchangeat the liquid-cooled condenser. As such, the coolant circuit augments the cooling capacity of the refrigerant circuit. When the valve is in the second position, the entirety of the superheated refrigerant vapor (e.g., both the first portion and the second portion) flows from the refrigerant compressor to the liquid-cooled condenser, and the air condenser is not used for condensing the refrigerant. By bypassing the air condenser, the temperature increase across the air condenser is avoided, thus enabling increased heat transfer at a proximate radiator of the coolant circuit.

[0024] For example, the radiator is fluidically coupled to a coolant outlet of the liquid- cooled condenser. The radiator receives the coolant, which has been further heated by the refrigerant at the liquid-cooled condenser. Moreover, due to the decreased reliance on heat transfer from the refrigerant to the ambient air at the air condenser, a temperature of the ambient air flowing across the radiator may be decreased. Due to the increased temperature of the coolant and the reduced temperature of the ambient air, a temperature difference between the coolant and the ambient air is increased. This larger temperature difference increases an efficiency of heat transfer from the coolant to the ambient air at the radiator.

[0025] In this way, the electric vehicle thermal management system has an increased overall cooling capacity and efficiency. By diverting a portion of the heat load of the refrigerant circuit to the coolant circuit, heat transfer at the radiator has increased efficiency, even during high ambient temperature conditions. Moreover, by including the liquid-cooled condenser to transfer heat from the superheated refrigerant to the coolant, the space constraint, heat transfer efficiency, air pressure drop, and degradationissues associated with increasing the air condenser size are avoided while the cooling capacity of the refrigerant circuit is increased.

[0026] Further discussion of these and other examples is included in the following description and shown in corresponding figures. A first example implementation of a thermal management system is shown in FIG. 1, which includes a liquid-cooled condenser coupled in series with an air condenser in a refrigerant circuit. The liquid- cooled condenser at least partially condenses refrigerant by diverting a portion of a heat load to a coolant circuit, such as according to the example procedure of FIG. 5. A second example implementation of the thermal management system is shown in FIGS. 2A-2C, which includes the liquid-cooled condenser coupled in parallel with the air condenser in the refrigerant circuit. A valve enables selection between flowing refrigerant to the liquid-cooled condenser alone or to both of the liquid-cooled condenser and the air condenser, enabling the thermal management system to operate in a plurality of modes based on a heat load, such as according to an example procedure depicted in FIG. 6. Including the liquid-cooled condenser results in an increased cooling capacity of the refrigerant circuit as well as an increased efficiency of the refrigerant circuit, which is demonstrated by example data graphically shown in FIGS. 3 and 4, respectively. Different operating modes that utilize the liquid-cooled condenser to increase the cooling capacity and efficiency of the refrigeration circuit are summarized in FIG. 7. FIG. 8 depicts an example vehicle system that may include the thermal management system of FIG. 1 or the thermal management system of FIGS. 2A-2C.

[0027] In the following discussion, an example environment is first described that may employ the techniques described herein. Examples of implementation details and procedures are then described which may be performed in the exemplary environment as well as other environments. Performance of the example procedures is not limited to the example environment, and the example environment is not limited to performance of the example procedures.Electric Vehicle Battery Cooling System

[0028] FIG. 1 schematically shows an example implementation of a thermal management system 100 of a vehicle. The thermal management system 100 includes a coolant circuit 102 and a refrigerant circuit 104. The coolant circuit 102 is configured to circulate liquid coolant 106 as a working fluid for heat transfer. The liquid coolant 106, referred to herein simply as “coolant 106,” may be, for example, water, a glycol-based antifreeze (e.g., ethylene glycol, propylene glycol, propylene glycol methyl ether), or a mixture thereof. The refrigerant circuit 104 (e.g., refrigerant loop) is configured to circulate refrigerant 108 as the working fluid for heat transfer. The refrigerant 108 may be, for example, a hydrochlorofluorocarbon-based refrigerant or a hydrofluorocarbon-based refrigerant. As will be elaborated below, the refrigerant 108 undergoes phase changes from a vapor to a liquid and vice versa as it absorbs and releases heat throughout the refrigerant circuit 104.

[0029] The coolant circuit 102 (e.g., coolant loop) is configured to circulate the coolant 106 through components of an electric propulsion system 110 via a plurality of coolant lines that form a sealed loop. By way of example, after being cooled at aradiator 112, the coolant 106 may flow to the electric propulsion system 110 via a first coolant line 114. As used herein, a “coolant line” refers to one or more conduits (e.g., flow passages) that fluidically couple components one to another. Heat transfer occurs between the electric propulsion system 110 and the coolant 106 as it flows through the electric propulsion system 110 components. In particular, heat is transferred from the hotter electric propulsion system 110 components to the cooler coolant 106, with an amount of heat transfer proportional to a temperature difference between the electric propulsion system 110 and the coolant 106. By way of example, the amount of heat transfer from the electric propulsion system 110 to the coolant 106 increases as the temperature difference increases. Examples of the components of the electric propulsion system 110 include an electric motor, a gearbox, one or more inverters, one or more power distribution units, and a high voltage fan. Additional details regarding examples of the electric propulsion system 110 will be described herein with respect to FIG. 8.

[0030] Due to the heat transfer from the electric propulsion system 110 to the coolant 106, the coolant 106 is hotter after passing through the electric propulsion system 110 and into a second coolant line 116. The second coolant line 116 fluidically couples the electric propulsion system 110 to a liquid-cooled condenser 118, also abbreviated as “LCC” in the figures. The liquid-cooled condenser 118 is positioned downstream of the electric propulsion system 110 and upstream of the radiator 112 in the coolant circuit 102. As used herein, a first component is considered to be “downstream” of a second component when the first component is arranged to receive flow (e.g., of the coolant 106 or the refrigerant 108) from the second component. Incontrast, the first component is considered to be “upstream” of the second component when the first component is positioned to output flow to the second component.

[0031] The liquid-cooled condenser 118 includes a coolant inlet 120 and a coolant outlet 122, and the coolant 106 flows through the liquid-cooled condenser 118 from the coolant inlet 120 to the coolant outlet 122. The liquid-cooled condenser 118 further includes a refrigerant inlet 124 and a refrigerant outlet 126. In the example illustrated in FIG. 1, the refrigerant inlet 124 is positioned on an opposite side of the liquid-cooled condenser 118 as the coolant inlet 120 and on a same side as the coolant outlet 122. The liquid-cooled condenser 118 is a heat exchanger (e.g., a plate heat exchanger) that is configured to condense the refrigerant 108, in its hot vapor form, into its liquid form by facilitating heat transfer from the refrigerant 108 to the coolant 106, as will be elaborated herein. As such, the liquid-cooled condenser 118 thermally couples (e.g., connects) the coolant circuit 102 and the refrigerant circuit 104.

[0032] Due to the heat transfer from the refrigerant 108 to the coolant 106 at the liquid- cooled condenser 118, the temperature of the coolant 106 is greater at the coolant outlet 122 than at the coolant inlet 120. The coolant outlet 122 is fluidically coupled to the radiator 112 via a third coolant line 128. The coolant 106, which has received heat transferred from the electric propulsion system 110 and from the refrigerant 108 via the liquid-cooled condenser 118, flows through the radiator 112, where it is cooled via heat transfer with ambient air. As described above, the amount of heat transfer from the coolant 106 to the ambient air increases as a temperature difference between the coolant 106 and the ambient air increases. As such, further increasing the temperature of the coolant 106 at the liquid-cooled condenser 118 results in a greater temperaturedifference between the coolant 106 and the ambient air at the radiator 112, thus increasing the amount of heat transfer that occurs at the radiator 112 compared to when the liquid-cooled condenser 118 is not used.

[0033] In at least one implementation, a pump 130 is disposed in the first coolant line 114, between the radiator 112 and the electric propulsion system 110, and is operated to circulate the coolant 106 through the coolant circuit 102. In at least one variation, the pump 130 is disposed in another location in the coolant circuit 102, such as in the second coolant line 116. However, positioning the pump 130 in the first coolant line 114, where the temperature of the coolant 106 is lower, may reduce heat- related degradation of the pump 130.

[0034] With respect to the refrigerant circuit 104, a receiver / dryer 132 (abbreviated as “R / D” in FIG. 1) at least temporarily stores the refrigerant 108, such as during periods of low cooling demand. The receiver / dryer 132 may include a filter and / or desiccant for removing contaminants and moisture, respectively, from the refrigerant 108 as the refrigerant 108 is circulated. When vehicle cabin cooling is requested (e.g., during high ambient temperature conditions), a shut-off valve 134 is at least partially open, allowing at least a portion of the refrigerant 108, in high-pressure liquid form, to flow into a first conduit 136 (e.g., a pipe or tubing) that fluidically couples the receiver / dryer 132 to an evaporator 138, abbreviated as “evap. 138” in FIG. 1. This flow path is indicated by dashed arrows in FIG. 1. In contrast, the refrigerant 108 may not flow into the first conduit 136 when the shut-off valve 134 is closed. By way of example, the shut-off valve 134 may be closed when cabin cooling is not requested.

[0035] An expansion valve 140 is positioned in the first conduit 136 between the shutoff valve 134 and the evaporator 138. The expansion valve 140 is a metering device that regulates the flow of the high-pressure liquid refrigerant 108 into the evaporator 138. In at least one implementation, the expansion valve 140 is a mechanical expansion valve, such as a thermostatic expansion valve (TXV). The expansion valve 140 creates a pressure drop, which causes the refrigerant 108 to rapidly expand into a low-pressure liquid. This expansion of the refrigerant 108 to the low-pressure gas also causes a temperature of the refrigerant 108 to decrease. As such, the evaporator 138 receives the refrigerant 108 as a low-pressure, low temperature liquid.

[0036] Heat from the vehicle cabin (not shown in FIG. 1) is transferred to the refrigerant 108 via the evaporator 138. By way of example, as the refrigerant 108 flows through coils of the evaporator 138, the refrigerant 108 absorbs heat from cabin air passing over the coils, thereby cooling the cabin air. After absorbing heat from the vehicle cabin, the refrigerant 108, in low-pressure gas form, flows from the evaporator 138 into a second conduit 142 that connects to a third conduit 144 at a junction 146.

[0037] The third conduit 144 also receives heated refrigerant 108 from a chiller 148. For example, in addition to or as an alternative to flowing into the first conduit 136 and to the evaporator 138, the refrigerant 108 flows from the receiver / dryer 132 into a fourth conduit 150 that fluidically couples the receiver / dryer 132 to the chiller 148. An expansion valve 152 is disposed in the fourth conduit 150 between the receiver / dryer 132 and the chiller 148. In at least one implementation, the expansion valve 152 is an electronic expansion valve (EXV), which is an electronically controlledvalve that is adjusted (e.g., modulated) by a control system 154 of the vehicle based on inputs from various sensors, such as one or more pressure and one or more temperature sensors. The electronic control of the expansion valve 152 may enable more accurate and rapid adjustments of a flow rate of the refrigerant 108 through the fourth conduit 150. In certain operating conditions, the expansion valve 152 may remain closed, such as when the chiller 148 is not used for cooling the battery. Similar to the expansion valve 140, the expansion valve 152 creates a pressure drop that causes the refrigerant 108 to rapidly expand into a low-pressure liquid before flowing into the chiller 148.

[0038] In one or more implementations, the expansion valve 140 and / or the expansion valve 152 is adjustable over a plurality of positions between and including a fully closed position (which blocks flow) and a fully open position (where flow is maximal). By way of example, the expansion valve 140 and / or the expansion valve 152 may be a continuously adjustable valve that is further opened or further closed to adjust the flow of the refrigerant 108.

[0039] In one or more implementations, the chiller 148 is a heat exchanger that transfers heat from a battery of the vehicle to the refrigerant 108. For example, as the coolant 106 flows through the battery via a battery coolant circuit (not shown), heat from the battery is transferred to the coolant 106, which then flows through the chiller 148 via a fourth coolant line 156 (only a portion of which is shown in FIG. 1 for illustrative clarity). As the coolant 106 and the refrigerant 108 both flow through the chiller 148, heat is transferred from the coolant 106 to the refrigerant 108. As such, the temperature of the refrigerant 108 increases, and it evaporates as it flows through thechiller 148 and into the third conduit 144. In contrast, the temperature of the coolant 106 decreases as it flows through the chiller 148.

[0040] An electric refrigerant compressor 158 (abbreviated as “eRC” in FIG. 1) receives the heated, low-pressure refrigerant 108 from the third conduit 144 and compresses it to a high-pressure, superheated refrigerant vapor. In one or more implementations, the electric refrigerant compressor 158 includes more than one compressor, which may be arranged in series or in parallel. The refrigerant inlet 124 of the liquid-cooled condenser 118 is fluidically coupled to the electric refrigerant compressor 158 via a fifth conduit 160 and receives the superheated refrigerant 108. The liquid-cooled condenser 118 diverts part of the heat load in the refrigerant circuit 104 to the radiator 112 by facilitating the heat transfer from the refrigerant 108 to the coolant 106. Due to the transfer of heat from the refrigerant 108 to the coolant 106 at the liquid-cooled condenser 118, the refrigerant 108 is at least partially condensed to a high-pressure, lower temperature liquid at the liquid-cooled condenser 118.

[0041] In the example shown in FIG. 1, the liquid-cooled condenser 118 is in series with an air condenser 162 and fluidically coupled to the air condenser 162 via a sixth conduit 164. The air condenser 162 receives the partially condensed refrigerant 108 from the liquid-cooled condenser 118 and facilitates further heat dissipation from the refrigerant 108. By way of example, as the refrigerant 108 flows through coils of the air condenser 162, the refrigerant 108 releases heat to the surrounding air and changes into a high-pressure liquid, which then flows to the receiver / dryer 132, as described above. By including the liquid-cooled condenser 118 in series with the aircondenser 162, an overall cooling capacity of the refrigerant circuit 104 is increased without increasing a size of the air condenser 162.

[0042] As mentioned above, FIG. 1 shows the control system 154. The control system 154 may be communicatively coupled to various components of the thermal management system 100 as well as to other components of the vehicle in order to cany out the control routines and actions described herein. For example, as shown in FIG. 1, control system 154 may include a controller 166. The controller 166 may be a microcomputer, including a microprocessor unit, input / output ports, an electronic storage medium for executable programs and calibration values, random access memory, keep alive memory, and a data bus. As depicted, the controller 166 may receive input from at least one of a plurality of sensors 168, examples of which include the temperature and pressure sensors of the expansion valve 152 as well as other sensors of the thermal management system 100 (e.g., a battery temperature sensor, a coolant temperature sensor, refrigerant temperature and pressure sensor, a fan speed sensor, a cabin temperature sensor, an ambient humidity sensor, an ambient temperature sensor, etc.), as well as other sensors from other vehicle systems. Further, the controller 166 may communicate with at least one of a plurality of actuators 170, examples of which include the shut-off valve 134, the expansion valve 140 and / or the expansion valve 152, the electric refrigerant compressor 158, and the pump 130. The plurality of actuators 170 may further include electric propulsion system 110 actuators, including an electric motor. In some examples, the storage medium may be programmed with computer-readable data representing instructions executable by the processor forperforming the methods (e.g., procedures) described below as well as other variants that are anticipated but not specifically listed.

[0043] FIGS. 2A-2C schematically show another example implementation of a thermal management system 200 of a vehicle. The thermal management system 200 is similar to the thermal management system 100 of FIG. 1. For example, the thermal management system 200 is a variation of the thermal management system 100 of FIG. 1. As such, like components are numbered the same and function as previously described.

[0044] The thermal management system 200 includes the coolant circuit 102 and a refrigerant circuit 202. The refrigerant circuit 202 is similar to the refrigerant circuit 104 of FIG. 1 except for the differences highlighted below. In particular, the liquid-cooled condenser 118 is arranged in parallel with the air condenser 162 in the refrigerant circuit 202, enabling the air condenser 162 to be bypassed during select operating modes. FIG. 2A shows flow through the refrigerant circuit 202 during a first operating mode 204, FIG. 2B shows flow through the refrigerant circuit 202 during a second operating mode 206, and FIG. 2C shows flow through the refrigerant circuit 202 during a third operating mode 208, as will be elaborated below.

[0045] In the refrigerant circuit 202, the sixth conduit 164 couples the liquid-cooled condenser 118 to the receiver / dryer 132, thus bypassing the air condenser 162. A valve 210 arranged at the outlet of the electric refrigerant compressor 158 enables control of the flow of the refrigerant 108 to the air condenser 162 via a seventh conduit 212. The valve 210 may be an electronically actuated valve, such as a solenoid valve, that is adjusted by the controller 166 in order to selectively stop the flow of therefrigerant 108 to the air condenser 162. As a non-limiting example, the valve 210 may be a 3 / 2 valve.

[0046] The controller 166, for instance, may position the valve 210 so that a flow path from the electric refrigerant compressor 158 to the seventh conduit 212 is open during the first operating mode 204 shown in FIG. 2A. The first operating mode 204 corresponds to a high heat load scenario where both vehicle cabin cooling and battery cooling are requested via the refrigerant circuit 202. This is indicated in FIG. 2A by arrows indicating flow of the refrigerant 108 through the evaporator 138 (e.g., via the open shut-off valve 134) and through the chiller 148 (e.g., via the expansion valve 152). During the first operating mode 204, the refrigerant 108 flows to the air condenser 162 via the seventh conduit 212 in addition to flowing to the liquid-cooled condenser 118 via the fifth conduit 160. Thus, the liquid-cooled condenser 118 is used to reject heat from a first portion of the refrigerant 108, and the air condenser 162 is used to reject heat from a second, remaining portion of the refrigerant 108 while operating in the first operating mode 204. By using both of the liquid-cooled condenser 118 and the air condenser 162, the thermal management system 200 has a greater cooling capacity than when either the liquid-cooled condenser 118 or the air condenser 162 is used alone.

[0047] On the other hand, the controller 166 may position the valve 210 so that the flow path from the electric refrigerant compressor 158 to the seventh conduit 212 is closed during low heat load scenarios, such as while operating in the second operating mode 206 or the third operating mode 208. No portion of the refrigerant 108 is condensed in the air condenser 162 while the valve 210 is positioned to block the flow path from the electric refrigerant compressor 158 to the seventh conduit 212, thusbypassing the air condenser 162, while operating the thermal management system 200 in the second operating mode 206 or the third operating mode 208.

[0048] For instance, during the second operating mode 206 shown in FIG. 2B, cabin cooling is not requested, and the shut-off valve 134 is closed. This is depicted in FIG. 2B by the absence of arrows indicating flow through the second conduit 142. During the second operating mode 206, battery cooling is requested, and the refrigerant 108 flows through the fourth conduit 150 to the chiller 148 to provide battery cooling. Because of the reduced cooling demand compared with the first operating mode 204 shown in FIG. 2A (e.g., when both cabin cooling and battery cooling are requested), the refrigerant 108 is condensed in the liquid-cooled condenser 118 alone.

[0049] In the third operating mode 208 shown in FIG. 2C, cabin cooling is requested while battery cooling via the chiller 148 is not requested. Thus, the shut-off valve 134 is open, enabling the refrigerant 108 to flow through the first conduit 136 and to the evaporator 138 to provide cabin cooling. In contrast, the expansion valve 152 is maintained closed so that the refrigerant 108 does not flow through the fourth conduit 150 to the chiller 148. Similar to the second operating mode 206, the reduced cooling demand during the third operating mode 208 (e.g., compared to the first operating mode 204) enables the refrigerant 108 to be condensed in the liquid-cooled condenser 118 alone. It is to be appreciated that in at least one variation, the air condenser 162 may be used for condensing the refrigerant 108 during low ambient temperature (e.g., low load) cooling of the cabin rather than the liquid-cooled condenser 118.

[0050] By using the liquid-cooled condenser 118 alone to fully condense the refrigerant 108 during conditions having reduced cooling demand, an operating efficiency of the thermal management system 200 may be increased by increasing an amount of heat transfer that occurs at the radiator 112, such as described above with respect to FIG. 1. Moreover, disabling use of the air condenser 162 during conditions of low cooling demand (e.g., the second operating mode 206 and the third operating mode 208) prevents an increase in a temperature of ambient air flowing across the air condenser 162 that would occur due to heat transfer from the refrigerant 108 to the ambient air at the air condenser 162. Because heat transfer to the ambient air also occurs at the radiator 112, by preventing the increase in the temperature of the ambient air at the air condenser 162, the efficiency of the heat transfer at the radiator 112 may be further improved.

[0051] The increased cooling capacity and efficiency obtained by including the liquid- cooled condenser 118 will now be described with reference to example data obtained during vehicle charging and while operating the electric refrigerant compressor 158 with standardized conditions (e.g., a discharge pressure of 24 bar and a discharge temperature of 120 °C).

[0052] FIG. 3 shows a bar graph 300 demonstrating an effect of incorporating a liquid- cooled condenser that thermally couples superheated refrigerant vapor with heated coolant on a cooling capacity of a refrigerant circuit. A first bar 302 shows the cooling capacity of the refrigerant circuit when the liquid-cooled condenser 118 is not included, while a second bar 304 shows the cooling capacity when the liquid-cooled condenser 118 is included, such as in the thermal management system 100 of FIG. 1 orthe thermal management system 200 of FIGS. 2A-2C. The cooling capacity (in kilowatts, or kW) increases when the liquid-cooled condenser 118 is included. In the example shown in FIG. 3, the cooling capacity is 31 kW when the liquid-cooled condenser 118 is included (e.g., the second bar 304), compared with 18.6 kW when the liquid-cooled condenser 118 is not included (e.g., the first bar 302). As such, the inclusion of the liquid-cooled condenser 118 increases the cooling capacity of the refrigerant circuit by more than 50%.

[0053] FIG. 4 shows a bar graph 400 demonstrating an effect of incorporating a liquid- cooled condenser that thermally couples superheated refrigerant vapor with heated coolant on an efficiency of a refrigerant circuit. A first bar 402 shows a coefficient of performance of the refrigerant circuit when the liquid-cooled condenser 118 is not included, while a second bar 404 shows the coefficient of performance when the liquid- cooled condenser 118 is included. The coefficient of performance is a ratio of a cooling output and an energy input and is a measure of the efficiency of the refrigerant circuit. As demonstrated by the bar graph 400, the coefficient of performance increases when the liquid-cooled condenser 118 is included. In the example shown in FIG. 4, the coefficient of performance is 1.55 when the liquid-cooled condenser 118 is included (e.g., the second bar 404), compared with 1.04 when the liquid-cooled condenser 118 is not included (e.g., the first bar 402). As such, the inclusion of the liquid-cooled condenser 118 increases the coefficient of performance of the refrigerant circuit by approximately 50%.Example Procedures

[0054] This section describes example procedures for an electric vehicle thermal management system. Aspects of the procedures may be implemented in hardware, firmware, software, or a combination thereof. The procedures are shown as a set of blocks that specify operations performed by one or more devices and are not necessarily limited to the orders shown for performing the operations by the respective blocks.

[0055] FIG. 5 is a flow diagram depicting an algorithm as a step-by-step procedure 500 in an example of implementing an electric vehicle thermal management system having a liquid-cooled condenser arranged to thermally couple superheated refrigerant vapor with heated coolant. For example, the electric vehicle thermal management system may be the thermal management system 100 of FIG. 1 or the thermal management system 200 of FIGS. 2A-2C. In at least one implementation, at least a portion of the procedure 500 is performable by the controller 166 of the control system 154. For example, instructions for carrying out the procedure 500 and the rest of the procedures included herein may be executed by the controller 166 based on instructions stored on one or more memories of the control system 154 and in conjunction with signals received from at least one of the plurality of sensors 168. The controller 166 may employ at least one of the plurality of actuators 170 to adjust operation the electric vehicle thermal management system according to the methods described below.

[0056] Operating conditions are estimated and / or measured (block 502). By way of example, the operating conditions include an operating status as well as a coolant temperature at one or more positions in a coolant circuit 102, a refrigerant pressure atone or more positions in a refrigerant circuit 104, a refrigerant temperature at one or more positions in the refrigerant circuit 104, a battery temperature, a vehicle speed, an ambient temperature, and so forth. The operating status may specify a vehicle status, such as whether the vehicle is running (e.g., powered on and operating) or stationary. The operating status may further specify a status of a battery of the vehicle, such as a fast-charging status, a standard charging status, or a preconditioning status. The fastcharging status is active when the battery is charged via a high output power source, which enables faster energy transfer to the battery but also generates additional heat compared with slower, standard charging methods, which use a lower output power source. The preconditioning status is active when the temperature of the battery is regulated prior to the vehicle being driven. For example, with the vehicle at rest during high ambient temperature conditions (e.g., at least 40 °C), the coolant 106 can act as a heat sink for the refrigerant circuit 104 as the refrigerant 108 passes through the liquid- cooled condenser 118.

[0057] Additionally or alternatively, the operating status includes an indication of whether cabin cooling is requested (which may include sleeper cab cooling, when present) and / or an indication of whether battery cooling via the chiller is requested. By way of example, cabin cooling is requested when the vehicle is operated and the ambient temperature is greater than a first threshold temperature (e.g., 25 °C). Additionally or alternatively, cabin cooling is requested in response to a cabin preconditioning status, which occurs at very high ambient temperatures (e.g., at least 40 °C) in order to cool the cabin prior to vehicle operation and while the vehicle is stationary. In contrast, cabin cooling may not be requested when the ambient temperature is less than the firstthreshold temperature and / or the cabin preconditioning status is not active. Battery cooling via the chiller, for instance, is requested in response to the fast-charging status or the preconditioning status being active. As another example, additionally or alternatively, battery cooling via the chiller is requested in response to the ambient temperature being above a second threshold temperature (e.g., 30 °C) while the vehicle is operated. As yet another example, additionally or alternatively, battery cooling via the chiller is requested in response to the ambient temperature being above a third threshold temperature (e.g., 20 °C) while the standard charging status is active. In contrast, battery cooling via the chiller is not requested while the vehicle is operated in lower ambient temperature conditions (e.g., when the ambient temperature is less than the second threshold temperature, such as between 20 and 30 °C) and / or while the ambient temperature is less than the third threshold temperature while the standard charging status is active.

[0058] Coolant is flowed through an electric propulsion system via a coolant loop (block 504). By way of example, a pump (e.g., the pump 130) positioned in the coolant loop may be operated at a speed calibrated to circulate coolant through the coolant loop at a desired flow rate. The speed of the pump may be regulated based on a pulse- width of electric power supplied to the pump, for instance.

[0059] Refrigerant is flowed through an evaporator of a cabin cooling system and / or a chiller of a battery cooling system via a refrigerant loop (block 506). By way of example, operation of a refrigerant compressor (e.g., the electric refrigerant compressor 158) causes the refrigerant to circulate through the refrigerant loop. A speed of the refrigerant compressor may be regulated based on a pulse- width of electricpower supplied to the refrigerant compressor, for instance. The refrigerant absorbs heat from surrounding air while flowing through the evaporator and / or absorbs heat from coolant while flowing through the chiller. As the refrigerant absorbs heat, it turns into a low-pressure vapor.

[0060] In accordance with the techniques described herein, operation of a shut-off valve is controlled based on whether cabin cooling is requested (block 508). By way of example, the shut-off valve (e.g., the shut-off valve 134) is opened and maintained in an open position when cabin cooling is requested so that the refrigerant flows to the evaporator (e.g., the evaporator 138) to provide cabin cooling. In contrast, the shut-off valve is closed (e.g., fully closed) and maintained in a closed position when cabin cooling is not requested so that the refrigerant does not flow to the evaporator.

[0061] Moreover, operation of an electric expansion valve is controlled based on whether battery cooling is requested (block 510). By way of example, the electric expansion valve is adjusted to control a flow rate of the refrigerant to the chiller (e.g., the chiller 148). The electric expansion valve may be closed (e.g., fully closed) when battery cooling is not requested, such as when low ambient temperature conditions are present and / or the vehicle is not operated, to block the flow of the refrigerant to the chiller. In contrast, the electric expansion valve may be at least partially open when battery cooling is requested, such as during high ambient temperature conditions, when the preconditioning status is active, and / or when the fast-charging status is active.

[0062] The refrigerant is compressed to a high-pressure, superheated refrigerant vapor by the refrigerant compressor (block 512). By way of example, the refrigerant compressor receives the high temperature, low-pressure refrigerant vapor from theevaporator and / or the chiller and compresses it, which increases its pressure and further increases its temperature. The refrigerant compressor thus discharges the refrigerant as the high-pressure, superheated refrigerant vapor.

[0063] The high-pressure, superheated refrigerant vapor is received at a liquid-cooled condenser that thermally couples the refrigerant loop to the coolant loop at a position that is downstream of the electric propulsion system and upstream of a radiator in the coolant loop (block 514). By way of example, a refrigerant inlet of the liquid-cooled condenser (e.g., the liquid-cooled condenser 118) may be fluidically coupled to an outlet of the refrigerant compressor.

[0064] In accordance with the described techniques, the liquid-cooled condenser may be coupled in series or in parallel with an air condenser (e.g., the air condenser 162). In implementations where the air condenser is coupled downstream of and in series with the liquid-cooled condenser 118 (e.g., as in the thermal management system 100), an entirely of the high-pressure, superheated refrigerant vapor is received by the liquid- cooled condenser. In variations where the air condenser is coupled in parallel with the liquid-cooled condenser (e.g., as in the thermal management system 200), the liquid- cooled condenser may receive at least a portion of the high-pressure, superheated refrigerant, as will be elaborated below and with respect to FIG. 6.

[0065] The refrigerant is at least partially condensed via the liquid-cooled condenser by transferring heat from the refrigerant to the coolant at the liquid-cooled condenser (block 516). By way of example, the liquid-cooled condenser receives coolant that has passed through the electric propulsion system (e.g., the electric propulsion system 110) and has thus absorbed heat from the electric propulsion system. The liquid-cooledcondenser thermally couples the refrigerant and the coolant such that additional heat is transferred to the coolant from the high-pressure, superheated refrigerant while flowing through respective paths in the liquid-cooled condenser. By transferring heat to the coolant, the temperature of the refrigerant decreases, thus causing the refrigerant to at least partially condense to its liquid form.

[0066] As mentioned above, the liquid-cooled condenser is coupled in series or in parallel with the air condenser. As a first option, partially condensed refrigerant is further condensed via the air condenser arranged downstream of the liquid-cooled condenser by transferring heat from the refrigerant to ambient air at the air condenser (block 518). By way of example, the air condenser receives the partially condensed refrigerant from the liquid-cooled condenser and further condenses it to the liquid form by facilitating heat transfer from the refrigerant to ambient air as the refrigerant flows through the air condenser. Because the air condenser receives the partially condensed refrigerant rather than the superheated refrigerant, a smaller sized condenser may be used to accommodate packaging space constraints without reducing an overall cooling capacity of the thermal management system.

[0067] As a second option, a valve arranged at an outlet of the refrigerant compressor is operated to enable or block flow to an air condenser arranged in parallel with the liquid-cooled condenser based on a heat load of the refrigerant circuit (block 520). As will be elaborated below with respect to FIG. 6, a position of the valve is controlled so that the liquid-cooled condenser receives an entirety of the high-pressure, superheated refrigerant from the refrigerant compressor or a portion of the high-pressure,superheated refrigerant. As such, during certain conditions (e.g., low heat load conditions), the refrigerant is fully condensed at the liquid-cooled condenser.

[0068] Heat is discharged from the coolant to the ambient air via a radiator (block 522). By way of example, the radiator is coupled to a coolant outlet of the liquid- cooled condenser and receives the coolant from the liquid-cooled condenser. The radiator facilitates heat transfer from the coolant to the ambient air, with an efficiency of the heat transfer increased due to the higher temperature of the coolant caused by the heat received from the refrigerant at the liquid-cooled condenser.

[0069] FIG. 6 is a flow diagram depicting an algorithm as a step-by-step procedure 600 in an example of implementing an electric vehicle thermal management system that includes a valve for controlling flow to an air condenser. For example, the electric vehicle thermal management system may be the thermal management system 200 of FIGS. 2A-2C. In at least one implementation, at least a portion of the procedure 600 is performable by the controller 166 of the control system 154 as a part of the procedure 500 of FIG. 5 (e.g., at block 520). As such, the procedure 600 may be a sub-routine of the procedure 500.

[0070] It is determined if a heat load of the refrigerant loop is greater than or equal to a threshold (block 602). By way of example, the heat load of the refrigerant loop may be greater than or equal to the threshold when both cabin cooling and battery cooling are requested, causing the refrigerant loop to operate in a high load condition. In contrast, the heat load of the refrigerant loop may be less than the threshold when cabin cooling or battery cooling is requested, causing the refrigerant loop to operate in a low load condition. Additionally or alternatively, the heat load of the refrigerant loop maybe greater than or equal to the threshold when a temperature of the refrigerant is greater than a threshold temperature. The threshold temperature may be a non- zero, positive temperature value that is stored in a memory of the controller and calibrated to distinguish low load conditions (e.g., where the refrigerant temperature is less than the threshold temperature) from high load conditions (e.g., where the refrigerant temperature is greater than or equal to the threshold temperature).

[0071] If the heat load is not greater than the threshold (e.g., the heat load is less than the threshold), the valve is positioned to block refrigerant flow through an air condenser that is arranged in parallel with a liquid-cooled condenser (block 604). By way of example, the controller may adjust the valve from a first position that enables flow to the air condenser to a second position that blocks flow to the air condenser. Alternatively, if the valve is already in the second position, the controller may maintain the valve in the second position so that the refrigerant does not flow from the refrigerant compressor to the air condenser. By operating the valve in the second position, an entirety of the refrigerant may flow from the refrigerant compressor to the liquid-cooled condenser via the valve.

[0072] The refrigerant is condensed via the liquid-cooled condenser by transferring heat from the refrigerant to the coolant at the liquid-cooled condenser (block 606). By way of example, the liquid-cooled condenser receives coolant that has passed through the electric propulsion system (e.g., the electric propulsion system 110) and has thus absorbed heat from the electric propulsion system. The liquid-cooled condenser also receives the entirety of the refrigerant exiting the refrigerant compressor, as mentioned above. The liquid-cooled condenser thermally couples the refrigerant and the coolantsuch that additional heat is transferred to the coolant from the high-pressure, superheated refrigerant as the refrigerant and the coolant flow through respective paths in the liquid-cooled condenser. By transferring heat to the coolant, the temperature of the refrigerant decreases, thus causing the refrigerant to condense to its liquid form.

[0073] On the other hand, if it is determined that the heat load is greater than the threshold at block 602, the valve is positioned to enable refrigerant flow through the air condenser that is arranged in parallel with the liquid-cooled condenser (block 608). By way of example, the controller may adjust the valve from the second position that blocks flow to the air condenser to the first position that enables flow from the refrigerant compressor to both of the liquid-cooled condenser and the air condenser. Alternatively, if the valve is already in the first position, the controller may maintain the valve in the first position. By operating the valve in the first position, a first portion of refrigerant flows from the refrigerant compressor to the to the liquid-cooled condenser via the valve, and a second, remaining portion of the refrigerant flows from the refrigerant compressor to the air condenser via the valve.

[0074] The first portion of the refrigerant is condensed via the liquid-cooled condenser by transferring heat from the first portion to the coolant at the liquid-cooled condenser (block 610). By way of example, the liquid-cooled condenser thermally couples the first portion of the refrigerant and the coolant such that additional heat is transferred to the coolant from the first portion of the high-pressure, superheated refrigerant as they flow through respective paths in the liquid-cooled condenser. By facilitating heat transfer to the coolant, the temperature of the first portion of the refrigerant decreases, thus causing the first portion of the refrigerant to condense to its liquid form.

[0075] A second, remaining portion of the refrigerant is condensed via the air condenser by transferring heat from the second portion to ambient air at the air condenser (block 612). By way of example, the air condenser receives the second portion of the refrigerant from the refrigerant compressor and condenses it to the liquid form by facilitating heat transfer from the second portion of refrigerant to ambient air as the second portion flows through the air condenser. It is to be appreciated that the first portion and the second portion may combine downstream of the air condenser, such as at a receiver / dryer or upstream of the receiver / dryer, as illustrated in FIG. 2A. Because the air condenser receives the second portion of the refrigerant, and not the entirety of the refrigerant, a smaller sized air condenser may be used to accommodate packaging space constraints without reducing an overall cooling capacity of the thermal management system.

[0076] FIG. 7 shows a summary table 700 of example operating modes of an electric vehicle thermal management system (e.g., the thermal management system 100 of FIG. 1 or the thermal management system 200 of FIGS. 2A-2C) that utilize a liquid- cooled condenser to increase a cooling capacity and efficiency of a refrigeration circuit. The summary table 700 is organized in columns and rows. A first column 702 defines a scenario of an operating mode of a given row, a second column 704 defines an example ambient temperature range at which the operating mode is active, and a third column 706 provides a description of the operating mode. The different operating modes may be predefined in a logic of the controller 166 and may be manually selected (e.g., by a vehicle operator) or automatically selected by the controller 166 based on pressure and temperature values measured by one or more of the plurality ofsensors 168. The controller 166 may adjust at least one of the plurality of actuators 170 to operate the electric vehicle thermal management system in the corresponding mode based on the predefined logic, such as summarized below.

[0077] A first row 708 of the summary table 700 describes a cabin cooling without battery cooling scenario, which may occur, for example, when the ambient temperature is greater than 25 °C. The cabin cooling without battery cooling scenario corresponds to the third operating mode 208 of FIG. 2C, for instance. During the cabin cooling without battery cooling scenario, the battery is not cooled by the chiller 148. The shutoff valve 134 is open to allow the refrigerant 108 to flow through the evaporator 138, while the expansion valve 152 is closed to block refrigerant flow through the chiller 148. After vaporizing at the evaporator 138, the refrigerant 108 is compressed in the electric refrigerant compressor 158. The liquid-cooled condenser 118 partially or entirely condenses the refrigerant 108, depending on a series or parallel arrangement of the liquid-cooled condenser 118 and the air condenser 162.

[0078] A second row 710 of the summary table 700 describes a battery cooling without cabin cooling scenario, which may occur, for example, when the ambient temperature is greater than 30 °C. The battery cooling without cabin cooling scenario corresponds to the second operating mode 206 of FIG. 2B, for instance. During the battery cooling without cabin cooling scenario, the coolant 106 flows from the battery and through the chiller 148. The expansion valve 152 in the refrigerant circuit 104 is open to enable heat transfer from the coolant 106 to the refrigerant 108 at the chiller 148, while the shut-off valve 134 is closed to prevent refrigerant flow through the evaporator 138.After vaporizing at the chiller 148, the refrigerant 108 is compressed in the electricrefrigerant compressor 158. The liquid-cooled condenser 118 partially or entirely condenses the refrigerant 108, depending on a series or parallel arrangement of the liquid-cooled condenser 118 and the air condenser 162.

[0079] A third row 712 of the summary table 700 describes a battery cooling and cabin cooling scenario, which may occur, for example, when the ambient temperature is greater than 30 °C. The battery cooling and cabin cooling scenario corresponds to the first operating mode 204 of FIG. 2A, for instance. During the battery cooling and cabin cooling scenario, the coolant 106 flows from the battery and through the chiller 148. The expansion valve 152 in the refrigerant circuit 104 is open to enable heat transfer from the coolant 106 to the refrigerant 108 at the chiller 148. The shut-off valve 134 is open to allow the refrigerant 108 to also flow through the evaporator 138. After vaporizing at the chiller 148 or the evaporator 138, the refrigerant 108 is compressed in the electric refrigerant compressor 158 before the liquid-cooled condenser 118 and the air condenser 162 are both used to condense the refrigerant 108.

[0080] A fourth row 714 of the summary table 700 describes a fast vehicle charging scenario, which may occur, for example, when the ambient temperature is in a range from 0 to 50 °C. The fast vehicle charging may produce substantial heat, and thus, the liquid-cooled condenser 118 may be used to increase the cooling capacity and efficiency of the refrigerant circuit 104 even during relatively low ambient temperature conditions (e.g., less than 20 °C). During the fast vehicle charging scenario, the coolant 106 flows from the battery and through the chiller 148. The expansion valve 152 in the refrigerant circuit 104 is open to enable heat transfer from the coolant 106 to the refrigerant 108 at the chiller 148, while the shut-off valve 134 is closed to prevent refrigerant flow throughthe evaporator 138. After vaporizing at the chiller 148, the refrigerant 108 is compressed in the electric refrigerant compressor 158 before the liquid-cooled condenser 118 at least partially condenses the refrigerant 108. Heat transferred to the coolant 106 at the liquid-cooled condenser 118 is discharged into ambient air at the radiator 112. Because the vehicle is at rest, the coolant 106 acts as a heat sink, enabling a higher cooling capacity in the refrigerant circuit 104.

[0081] A fifth row 716 of the summary table 700 describes a standard vehicle charging during high ambient conditions scenario, which may occur, for example, when the ambient temperature is in a range from 20 to 50 °C. The standard charging produces heat, albeit less than during the fast vehicle charging condition described above. As such, a temperature range during which the liquid-cooled condenser 118 is used to increase the cooling capacity and efficiency of the refrigerant circuit 104 is smaller than that used for the fast vehicle charging scenario and occurs during higher ambient temperature conditions, (e.g., greater than 20 °C).

[0082] In the standard vehicle charging during high ambient conditions scenario, the coolant 106 flows from the battery and through the chiller 148. The expansion valve 152 in the refrigerant circuit 104 is open to enable heat transfer from the coolant 106 to the refrigerant 108 at the chiller 148, while the shut-off valve 134 is closed to prevent refrigerant flow through the evaporator 138. After vaporizing at the chiller 148, the refrigerant 108 is compressed in the electric refrigerant compressor 158 before the liquid-cooled condenser 118 at least partially condenses the refrigerant 108.Heat transferred to the coolant 106 at the liquid-cooled condenser 118 is discharged intoambient air at the radiator 112. Because the vehicle is at rest, the coolant 106 acts as a heat sink, enabling a higher cooling capacity in the refrigerant circuit 104.

[0083] A sixth row 718 of the summary table 700 describes a vehicle preconditioning scenario, which may occur, for example, when the ambient temperature is greater than 40 °C. The vehicle preconditioning is used to rapidly cool both the cabin and the battery prior to vehicle operation, for instance, in response to a high ambient temperature condition (e.g., greater than 40 °C). During the vehicle preconditioning scenario, the coolant 106 flows from the battery and through the chiller 148. The expansion valve 152 in the refrigerant circuit 104 is open to enable heat transfer from the coolant 106 to the refrigerant 108 at the chiller 148, while the shut-off valve 134 is open to allow the refrigerant 108 to also flow through the evaporator 138. After vaporizing at the chiller 148 or the evaporator 138, the refrigerant 108 is compressed in the electric refrigerant compressor 158 before the liquid-cooled condenser 118 and the air condenser 162 are both used to condense the refrigerant 108. Heat transferred to the coolant 106 at the liquid-cooled condenser 118 is discharged into ambient air at the radiator 112. Because the vehicle is at rest, the coolant 106 acts as a heat sink, enabling a higher cooling capacity in the refrigerant circuit 104.

[0084] It is to be appreciated that other scenarios are also possible, and the electric vehicle thermal management system may be operated in additional operating modes that do not utilize the liquid-cooled condenser 118 to increase the cooling capacity and efficiency of the refrigerant circuit 104. For example, during a vehicle cold starting condition, which may occur at ambient temperatures between -20 and 20 °C, battery heating may be requested rather than cooling. In such a scenario, the coolant 106 thatflows through the battery is instead heated, e.g., with an electrical resistance heater. Similarly, battery and cabin heating may be used during a preconditioned cold start of the vehicle (which may occur at ambient temperatures between -20 and 0 °C) as well as for a defrost mode that is used while the vehicle is stationary at very low ambient temperatures (e.g., less than -5 °C). In still other conditions, sufficient battery cooling may be achieved via a low temperature radiator rather than via the chiller 148. For example, while the vehicle is running during moderate ambient temperature conditions (e.g., between 20 and 30 °C), the battery cooling may be achieved via the low temperature radiator by actuating a valve in a battery coolant circuit that bypasses the chiller 148 and directs the coolant to the low temperature radiator. A same or similar control logic may be used during standard vehicle charging at low ambient temperature conditions (e.g., between 0 and 20 °C) because the heat generated during charging may be effectively discharged via the low temperature radiator. As such, the liquid-cooled condenser 118 may be selectively utilized to provide increased cooling capacity and efficiency to the refrigerant circuit 104 based on the operating conditions and instructions stored in a non- transitory memory of the controller 166.Example Vehicle System

[0085] FIG. 8 is a top view schematically illustrating an example configuration of a vehicle 800 in which the techniques described herein may be implemented. In the example illustrated in FIG. 8, the vehicle 800 is an electric truck including a ladder frame 802 (e.g., a vehicle chassis), a cab 804, a packing box 806, a wheel mechanism 808, and a thermal management system 810, which includes components ofthe thermal management system 100 of FIG. 1 and / or the thermal management system 200 of FIGS. 2A-2C. The vehicle 800 further includes, from FIG. 1, the electric propulsion system 110 and the control system 154 including the controller 166, the plurality of sensors 168, and the plurality of actuators 170. FIG. 8 is illustrated as a top view where the cab 804 and the packing box 806 are transparent, as indicated by dashed boundaries.

[0086] In the example shown in FIG. 8, the electric propulsion system 110 includes an inverter 812, a battery 814, an electric motor 816, a speed reduction mechanism 818, and a differential 820. The electric motor 816 generates a driving force for propelling the vehicle 800 from AC power supplied by the inverter 812, as will be elaborated below. As such, the vehicle 800 is a battery electric vehicle (BEH). Alternatively, the vehicle 800 may be a hybrid electric vehicle (HEV) that includes an internal combustion engine in addition to the electric motor 816, and the internal combustion engine may be selectively operated to provide at least a portion of the power used to propel the vehicle 800 depending on an operating mode. Moreover, rather than an electric truck, the vehicle 800 may be another type of electric commercial vehicle, such as a cargo van.

[0087] The inverter 812 converts DC power supplied from the battery 814 to AC power and supplies it to the electric motor 816. The inverter 812 further controls the rotational speed of the electric motor 816 in accordance with an accelerator operation to the vehicle 800. The battery 814 supplies power to the electric motor 816 as an energy source for producing torque to propel the vehicle 800. The battery 814 includes a plurality of battery modules, also termed battery packs, which are relatively large-sized and have a large energy storage capacity in order to store enough power for propelling the vehicle 800. Furthermore, a DC-DC converter 822 is included as a power converting device for supplying power to low-voltage devices mounted on the vehicle 800 by lowering a voltage of the relatively high-voltage power output from the battery 814.

[0088] The ladder frame 802 includes side rails 824 and a plurality of cross members 826, only one of which is labeled for illustrative clarity. Moreover, the side rails 824 extend in a vehicle longitudinal direction X of the vehicle 800, from the front to the rear of the vehicle 800. For example, the side rails 824 include a left side rail and a right side rail disposed in parallel to each other in a vehicle width direction Y. The plurality of cross members 826 connect the left side rail and the right side rail and stabilize the side rails 824 with respect to each other. The ladder frame 802 supports the cab 804, the packing box 806, the electric propulsion system 110, the inverter 812, the battery 814, and other heavy articles mounted on the vehicle 800.

[0089] The cab 804 is a structural body including a driver’ s seat (not shown) and is provided on an upper front part of the ladder frame 802. The cab 804 may further include a sleeper cab. By way of example, the cab 804 is a vehicle cabin that may receive air cooled via the evaporator 138 introduced in FIG. 1. The packing box 806 is a structural body on which cargo carried by the vehicle 800 is mounted and is provided on an upper rear part of the ladder frame 802.

[0090] The wheel mechanism 808 comprises left and right front wheels 828 located on the front of the vehicle, a front axle 830 as an axle of the front wheels 828, rear wheels 832 located on the rear of the vehicle and disposed two each on the left and right,and a real' axle 834 as an axle of the rear wheels 832. In the example depicted in FIG. 7, the vehicle 800 is a real’ drive vehicle, with the driving force transmitted to the rear wheels 832 via the rear axle 834. By way of example, the rear axle 834 may be an electric axle. It is to be appreciated that the wheel mechanism 808 may be suspended by the ladder frame 802 through a suspension mechanism (not shown) and supports the weight of the vehicle 800.

[0091] The speed reduction mechanism 818 reduces a rotary torque input from the electric motor 816 and outputs it to the differential 820. For example, the speed reduction mechanism 818 includes one or more gears for reducing the torque produced by the electric motor 816 for input to the differential 820. The differential 820 distributes the power input from the speed reduction mechanism 818 to the rear wheels 832. For example, the electric propulsion system 110 reduces the torque of the electric motor 816 to a rotational speed suitable for a desired speed of vehicle travel through the speed reduction mechanism 818, and the differential 820 and transmits the driving force to the rear axle 834. As a result, the electric propulsion system 110 may rotate the rear wheels 832 through the rear axle 834 and cause the vehicle 800 to travel.

[0092] The battery 814 may be charged with power generated by regenerative braking, where kinetic energy of the vehicle is transformed into electric energy by the electric motor 816. That is, in at least one implementation, the electric motor 816 is a motor / generator that is capable of both transforming electrical energy stored in the battery 814 into kinetic energy used to propel the vehicle and transforming the kinetic energy of the vehicle into electrical energy for storage at the battery 814. For example, the rotation of the rear wheels 832 turns the electric motor 816, which generateselectricity during a speed reduction event. As such, regenerative braking allows the electric propulsion system 110 to recover some of the energy that would otherwise be lost during braking, which increases an efficiency of the vehicle 800.

[0093] The thermal management system 810 includes a drive component cooling system 836 and a cabin cooling system 838. For example, the drive component cooling system 836 includes components of the thermal management system 810 that are used to provide cooling to components of the electric propulsion system 110, including, from FIGS. 1-2C, the coolant circuit 102 (e.g., the coolant 106, the radiator 112, the liquid- cooled condenser 118, the pump 130, and the associated coolant lines) and portions of the refrigerant circuit 104 or the refrigerant circuit 202, including the chiller 148. The cabin cooling system 838 includes components of the thermal management system 810 that are used to provide cooling to the cab 804, including, from FIGS. 1-2C, the refrigerant 108, the liquid-cooled condenser 118, the evaporator 138, the electric refrigerant compressor 158, and associated conduits and valves. Thus, it may be appreciated that some components are included in both the drive component cooling system 836 and the cabin cooling system 838. In addition to the components previously described with respect to FIGS. 1-2C, the thermal management system 810 may further include a fan 840 that is operated to increase air flow across components of the drive component cooling system 836 and / or the cabin cooling system 838, such as the radiator 112 and / or the air condenser 162.

[0094] In this way, the liquid-cooled condenser thermally couples the refrigerant in the refrigerant circuit to the coolant in the coolant circuit, thus increasing a cooling capacity and efficiency of the refrigerant circuit without increasing the size of the air condenser.As a result, challenges that come with increasing the size of the air condenser, such as packaging constraints and the effects of airflow and pressure across the larger air condenser, may be avoided. Moreover, an incidence of compressor overloading may be reduced by including the liquid-cooled condenser rather than a larger air condenser.

[0095] In one aspect, provided herein is an electric vehicle thermal management system, comprising; a coolant circuit configured to circulate coolant through components of an electric propulsion system, a refrigerant circuit configured to circulate refrigerant and comprising a refrigerant compressor, and a liquid-cooled condenser configured to thermally couple the coolant in the coolant circuit to the refrigerant in the refrigerant circuit, the liquid-cooled condenser arranged downstream of the electric propulsion system in the coolant circuit and downstream of the refrigerant compressor in the refrigerant circuit. In a first example of the system, the coolant circuit further comprises a radiator fluidically coupled to a coolant outlet of the liquid-cooled condenser. In a second example of the system, optionally including the first example, a coolant inlet of the liquid-cooled condenser is positioned to receive heated coolant from the components of the electric propulsion system. In a third example of the system, optionally including one or both of the first and second examples, a refrigerant inlet of the liquid-cooled condenser is fluidically coupled to an outlet of the refrigerant compressor, the refrigerant inlet positioned to receive superheated refrigerant vapor from the refrigerant compressor. In a fourth example of the system, optionally including one or more or each of the first through third examples, the refrigerant circuit further comprises an air condenser arranged in series with the liquid-cooled condenser in the refrigerant circuit.In a fifth example of the system, optionally including one or more or each of the firstthrough fourth examples, the air condenser is fluidically coupled to a refrigerant outlet of the liquid-cooled condenser. In a sixth example of the system, optionally including one or more or each of the first through fifth examples, the refrigerant circuit further comprises an air condenser arranged in parallel with the liquid-cooled condenser, downstream of the refrigerant compressor. In a seventh example of the system, optionally including one or more or each of the first through sixth examples, the system further comprises: a valve arranged at an outlet of the refrigerant compressor and adjustable to block or enable flow between the refrigerant compressor and the air condenser, and a controller including executable instructions stored in non-transitory memory that, when executed, cause the controller to: position the valve to enable a first portion of the refrigerant to flow from the refrigerant compressor to the liquid-cooled condenser and a second, remaining portion of the refrigerant to flow to the air condenser in response to a high heat load operating condition, and position the valve to block the flow of the refrigerant to the air condenser and enable both of the first portion and the second, remaining portion of the refrigerant to flow from the refrigerant compressor to the liquid-cooled condenser in response to a low heat load operating condition. In an eighth example of the system, optionally including one or more or each of the first through seventh examples, the high heat load operating condition comprises a heat load of the refrigerant circuit being greater than or equal to a threshold, and the low heat load operating condition comprises the heat load of the refrigerant circuit being less than the threshold. In a ninth example of the system, optionally including one or more or each of the first through eighth examples, the high heat load operating condition comprises both of cabin cooling and battery cooling by the refrigerant circuit being requested, andthe low heat load operating condition comprises one of the cabin cooling and the battery cooling by the refrigerant circuit being requested. In a tenth example of the system, optionally including one or more or each of the first through ninth examples, the high heat load operating condition comprises a vehicle charging condition where additional cooling capacity at the refrigerant circuit is requested.

[0096] In another aspect, provided herein is a method for an electric vehicle thermal management system, comprising: flowing coolant through an electric propulsion system via a coolant loop, flowing refrigerant through at least one of an evaporator of a cabin cooling system and a chiller of a battery cooling system via a refrigerant loop, compressing the refrigerant to a superheated refrigerant vapor by a refrigerant compressor positioned downstream of both of the evaporator and the chiller, receiving the superheated refrigerant vapor at a liquid-cooled condenser that thermally couples the refrigerant loop to the coolant loop at a position that is downstream of the electric propulsion system and upstream of a radiator in the coolant loop, and at least partially condensing the refrigerant via the liquid-cooled condenser by enabling heat transfer from the superheated refrigerant vapor to the coolant at the liquid-cooled condenser. In a first example of the method, at least partially condensing the refrigerant via the liquid- cooled condenser by enabling heat transfer from the superheated refrigerant vapor to the coolant at the liquid-cooled condenser comprises: partially condensing the refrigerant via the liquid-cooled condenser, flowing the partially condensed refrigerant to an air condenser arranged downstream of the liquid-cooled condenser and in series with the liquid-cooled condenser, and further condensing the partially condensed refrigerant via the air condenser by enabling further heat transfer from the partiallycondensed refrigerant to ambient air at the air condenser. In a second example of the method, optionally including the first example, at least partially condensing the refrigerant via the liquid-cooled condenser by enabling heat transfer from the superheated refrigerant vapor to the coolant at the liquid-cooled condenser comprises: operating a valve positioned at an outlet of the refrigerant compressor, upstream of the liquid-cooled condenser, to block or enable flow to an air condenser arranged in parallel with the liquid-cooled condenser based on a heat load of the refrigerant loop relative to a threshold, including: operating the valve to block flow to the air condenser in response to the heat load of the refrigerant loop being less than the threshold, and condensing an entirety of the refrigerant via the liquid-cooled condenser. In a third example of the method, optionally including one or both of the first and second examples, operating the valve positioned at the outlet of the refrigerant compressor to block or enable flow to the air condenser based on the heat load of the refrigerant loop relative to the threshold comprises: operating the valve to enable flow to the air condenser in response to the heat load of the refrigerant loop being greater than or equal to the threshold, condensing a first portion of the refrigerant via the liquid-cooled condenser by enabling heat transfer from the first portion to the coolant at the liquid-cooled condenser, and condensing a second, remaining portion of the refrigerant via the air condenser by enabling heat transfer from the second, remaining portion to ambient air at the air condenser.

[0097] In another aspect, provided herein is an electric vehicle thermal management system, comprising: a coolant circuit configured to circulate coolant through components of an electric propulsion system and to transfer heat from the coolant toambient air at a radiator, a refrigerant circuit configured to circulate refrigerant through at least one of an evaporator and a chiller, the evaporator and the chiller each arranged downstream of a receiver / dryer and upstream of a refrigerant compressor, and a liquid- cooled condenser configured to thermally couple the coolant in the coolant circuit to the refrigerant in the refrigerant circuit, the liquid-cooled condenser arranged downstream of the electric propulsion system and upstream of the radiator in the coolant circuit and downstream of the refrigerant compressor and upstream of the receiver / dryer in the refrigerant circuit. In a first example of the system, the refrigerant circuit further comprises an air condenser arranged in series with the liquid-cooled condenser and upstream of the receiver / dryer, the air condenser positioned to receive the refrigerant from the liquid-cooled condenser after the refrigerant has been partially condensed at the liquid-cooled condenser. In a second example of the system, optionally including the first example, the refrigerant circuit further comprises: an air condenser arranged in parallel with the liquid-cooled condenser, downstream of the refrigerant compressor and upstream of the receiver / dryer, and a valve arranged at an outlet of the refrigerant compressor and adjustable to between a first position that enables flow from the refrigerant compressor to both of the liquid-cooled condenser and the air condenser and a second position that enables flow from the refrigerant compressor to the liquid-cooled condenser while blocking flow from the refrigerant compressor to the air condenser. In a third example of the system, optionally including one or both of the first and second examples, the system further comprises: a controller including executable instructions stored in non-transitory memory that, when executed, cause the controller to: operate the valve in the first position in response to a heat load of the refrigerant circuit beinggreater than or equal to a threshold, and operate the valve in the second position in response to the heat load of the refrigerant circuit being less than the threshold. In a fourth example of the system, optionally including one or more or each of the first through third examples, the heat load is greater than or equal to the threshold when the refrigerant is circulated through both of the evaporator and the chiller, and wherein the heat load is less than the threshold when the refrigerant is circulated through one of the evaporator and the chiller.

[0098] Although the systems and techniques have been described in language specific to structural features and / or methodological acts, it is to be understood that the systems and techniques defined in the appended claims are not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as example forms of implementing the claimed subject matter.

[0099] Note that the example control and estimation routines included herein can be used with various engine and / or vehicle system configurations. The control methods and routines disclosed herein may be stored as executable instructions in non- transitory memory and may be canned out by the control system including the controller in combination with the various sensors, actuators, and other vehicle hardware. The specific routines described herein may represent one or more of any number of processing strategies such as event-driven, interrupt-driven, multi-tasking, multithreading, and the like. As such, various actions, operations, and / or functions illustrated may be performed in the sequence illustrated, in parallel, or in some cases omitted. Likewise, the order of processing is not necessarily required to achieve the features and advantages of the example implementations described herein but is provided for ease ofillustration and description. One or more of the illustrated actions, operations and / or functions may be repeatedly performed depending on the particular strategy being used. Further, the described actions, operations and / or functions may graphically represent code to be programmed into non-transitory memory of the computer readable storage medium in the engine control system, where the described actions are carried out by executing the instructions in a system including the various engine hardware components in combination with the electronic controller.

[0100] It will be appreciated that the configurations and routines disclosed herein are illustrative in nature, and that these specific implementations are not to be considered in a limiting sense because numerous variations are possible. The subject matter of the present disclosure includes all novel and non-obvious combinations and subcombinations of the various systems and configurations, and other features, functions, and / or properties disclosed herein.

[0101] The following claims particularly point out certain combinations and subcombinations regarded as novel and non-obvious. These claims may refer to “an” element or “a first” element or the equivalent thereof. Such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements. Moreover, the terms “first,” “second,” and “third,” etc. are used merely as labels and are not intended to impose numerical requirements or a particular positional order on their objects. Other combinations and sub-combinations of the disclosed features, functions, elements, and / or properties may be claimed through amendment of the present claims or through presentation of new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scopeto the original claims, also are regarded as included within the subject matter of the present disclosure.

Claims

CLAIMSWhat is claimed is:

1. An electric vehicle thermal management system, comprising: a coolant circuit configured to circulate coolant through components of an electric propulsion system; a refrigerant circuit configured to circulate refrigerant and comprising a refrigerant compressor; and a liquid-cooled condenser configured to thermally couple the coolant in the coolant circuit to the refrigerant in the refrigerant circuit, the liquid-cooled condenser arranged downstream of the electric propulsion system in the coolant circuit and downstream of the refrigerant compressor in the refrigerant circuit.

2. The electric vehicle thermal management system of claim 1, wherein the coolant circuit further comprises a radiator fluidically coupled to a coolant outlet of the liquid-cooled condenser.

3. The electric vehicle thermal management system of claim 1 or 2, wherein a coolant inlet of the liquid-cooled condenser is positioned to receive heated coolant from the components of the electric propulsion system.

4. The electric vehicle thermal management system of any one of claims 1- 3, wherein a refrigerant inlet of the liquid-cooled condenser is fluidically coupled to anoutlet of the refrigerant compressor, the refrigerant inlet positioned to receive superheated refrigerant vapor from the refrigerant compressor.

5. The electric vehicle thermal management system of any one of claims 1- 4, wherein the refrigerant circuit further comprises an air condenser arranged in series with the liquid-cooled condenser in the refrigerant circuit.

6. The electric vehicle thermal management system of claim 5, wherein the air condenser is fluidically coupled to a refrigerant outlet of the liquid-cooled condenser.

7. The electric vehicle thermal management system of any one of claims 1- 4, wherein the refrigerant circuit further comprises an air condenser arranged in parallel with the liquid-cooled condenser, downstream of the refrigerant compressor.

8. The electric vehicle thermal management system of claim 7, further comprising: a valve arranged at an outlet of the refrigerant compressor and adjustable to block or enable flow between the refrigerant compressor and the air condenser; and a controller including executable instructions stored in non- transitory memory that, when executed, cause the controller to:position the valve to enable a first portion of the refrigerant to flow from the refrigerant compressor to the liquid-cooled condenser and a second, remaining portion of the refrigerant to flow to the air condenser in response to a high heat load operating condition; and position the valve to block the flow of the refrigerant to the air condenser and enable both of the first portion and the second, remaining portion of the refrigerant to flow from the refrigerant compressor to the liquid-cooled condenser in response to a low heat load operating condition.

9. The electric vehicle thermal management system of claim 8, wherein the high heat load operating condition comprises a heat load of the refrigerant circuit being greater than or equal to a threshold, and the low heat load operating condition comprises the heat load of the refrigerant circuit being less than the threshold.

10. The electric vehicle thermal management system of claim 8 or claim 9, wherein the high heat load operating condition comprises both of cabin cooling and battery cooling by the refrigerant circuit being requested, and the low heat load operating condition comprises one of the cabin cooling and the battery cooling by the refrigerant circuit being requested.

11. The electric vehicle thermal management system of any one of claims 8- 10, wherein the high heat load operating condition comprises a vehicle charging condition where additional cooling capacity at the refrigerant circuit is requested.

12. A method for an electric vehicle thermal management system, comprising: flowing coolant through an electric propulsion system via a coolant loop; flowing refrigerant through at least one of an evaporator of a cabin cooling system and a chiller of a battery cooling system via a refrigerant loop; compressing the refrigerant to a superheated refrigerant vapor by a refrigerant compressor positioned downstream of both of the evaporator and the chiller; receiving the superheated refrigerant vapor at a liquid-cooled condenser that thermally couples the refrigerant loop to the coolant loop at a position that is downstream of the electric propulsion system and upstream of a radiator in the coolant loop; and at least partially condensing the refrigerant via the liquid-cooled condenser by enabling heat transfer from the superheated refrigerant vapor to the coolant at the liquid- cooled condenser.

13. The method of claim 12, wherein at least partially condensing the refrigerant via the liquid-cooled condenser by enabling heat transfer from the superheated refrigerant vapor to the coolant at the liquid-cooled condenser comprises: partially condensing the refrigerant via the liquid-cooled condenser; flowing the partially condensed refrigerant to an air condenser arranged downstream of the liquid-cooled condenser and in series with the liquid-cooled condenser; andfurther condensing the partially condensed refrigerant via the air condenser by enabling further heat transfer from the partially condensed refrigerant to ambient air at the air condenser.

14. The method of claim 12, wherein at least partially condensing the refrigerant via the liquid-cooled condenser by enabling heat transfer from the superheated refrigerant vapor to the coolant at the liquid-cooled condenser comprises: operating a valve positioned at an outlet of the refrigerant compressor, upstream of the liquid-cooled condenser, to block or enable flow to an air condenser arranged in parallel with the liquid-cooled condenser based on a heat load of the refrigerant loop relative to a threshold, including: operating the valve to block flow to the air condenser in response to the heat load of the refrigerant loop being less than the threshold; and condensing an entirety of the refrigerant via the liquid-cooled condenser.

15. The method of claim 14, wherein operating the valve positioned at the outlet of the refrigerant compressor to block or enable flow to the air condenser based on the heat load of the refrigerant loop relative to the threshold comprises: operating the valve to enable flow to the air condenser in response to the heat load of the refrigerant loop being greater than or equal to the threshold; condensing a first portion of the refrigerant via the liquid-cooled condenser by enabling heat transfer from the first portion to the coolant at the liquid-cooled condenser; andcondensing a second, remaining portion of the refrigerant via the air condenser by enabling heat transfer from the second, remaining portion to ambient air at the air condenser.

16. An electric vehicle thermal management system, comprising: a coolant circuit configured to circulate coolant through components of an electric propulsion system and to transfer heat from the coolant to ambient air at a radiator; a refrigerant circuit configured to circulate refrigerant through at least one of an evaporator and a chiller, the evaporator and the chiller each arranged downstream of a receiver / dryer and upstream of a refrigerant compressor; and a liquid-cooled condenser configured to thermally couple the coolant in the coolant circuit to the refrigerant in the refrigerant circuit, the liquid-cooled condenser arranged downstream of the electric propulsion system and upstream of the radiator in the coolant circuit and downstream of the refrigerant compressor and upstream of the receiver / dryer in the refrigerant circuit.

17. The electric vehicle thermal management system of claim 16, wherein the refrigerant circuit further comprises an air condenser arranged in series with the liquid- cooled condenser and upstream of the receiver / dryer, the air condenser positioned to receive the refrigerant from the liquid-cooled condenser after the refrigerant has been partially condensed at the liquid-cooled condenser.

18. The electric vehicle thermal management system of claim 16, wherein the refrigerant circuit further comprises: an air condenser arranged in parallel with the liquid-cooled condenser, downstream of the refrigerant compressor and upstream of the receiver / dryer; and a valve arranged at an outlet of the refrigerant compressor and adjustable to between a first position that enables flow from the refrigerant compressor to both of the liquid-cooled condenser and the air condenser and a second position that enables flow from the refrigerant compressor to the liquid-cooled condenser while blocking flow from the refrigerant compressor to the air condenser.

19. The electric vehicle thermal management system of claim 18, further comprising: a controller including executable instructions stored in non-transitory memory that, when executed, cause the controller to: operate the valve in the first position in response to a heat load of the refrigerant circuit being greater than or equal to a threshold; and operate the valve in the second position in response to the heat load of the refrigerant circuit being less than the threshold.

20. The electric vehicle thermal management system of claim 19, wherein the heat load is greater than or equal to the threshold when the refrigerant is circulated through both of the evaporator and the chiller, and wherein the heat load is less than the threshold when the refrigerant is circulated through one of the evaporator and the chiller.

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