SE543871C2

SE543871C2 - Radiator assembly, Powertrain, and Vehicle

Info

Publication number: SE543871C2
Application number: SE1851577A
Authority: SE
Inventors: Matthias Ussner; Ola Hall; Zoltan Kardos
Original assignee: Scania Cv Ab
Priority date: 2018-12-14
Filing date: 2018-12-14
Publication date: 2021-08-17
Also published as: DE102019008256B4; SE1851577A1; DE102019008256A1

Abstract

A radiator assembly (4) for a vehicle (3) is disclosed. The radiator assembly (4) comprises an engine radiator (46), a charge air cooler (72), and one or more low temperature radiators (70, 70’, 74). The radiator assembly (4) is configured to be subjected to a flow of air having a flow direction (d). The charge air cooler (72) is arranged in front of the engine radiator (46) seen in the flow direction (d). The charge air cooler (72) comprises an inflow half portion (72’) and an outflow half portion (72”), the inflow half portion (72’) having a higher temperature than the outflow half portion (72”) during operation of the charge air cooler (72). At least one radiator (70’, 74) of the one or more low temperature radiators (70, 70’, 74) superimposes a greater proportion of the inflow half portion (72’) than the outflow half portion (72”) seen in the flow direction (d). The present disclosure further relates to a powertrain (1) and a vehicle (3).

Description

Radiator assembly, Powertrain, and Vehicle TECHNICAL FIELDThe present disclosure relates to a radiator assembly for a vehicle. The present disclosure further relates to a powertrain and a vehicle.

BACKGROUND Modern vehicles usually comprise several cooling systems each arranged to cool a vehiclesystem such as a combustion engine, an electric propulsion system, a retarder, a waste heatrecovery system, and the like. Such cooling systems usually comprise one or more radiators arranged to transfer heat from the cooling system to ambient air.

Hybrid electric powertrains use two or more distinct types of power, such as an internalcombustion engine and an electric propulsion system. Generally, an internal combustionengine has poor energy efficiency at lower power output levels and better energy efficiencyat higher power output levels. An electric propulsion system usually has great energyefficiency at low power output levels and at high power output levels, but the storage ofelectric energy in the vehicle is usually insufficient for allowing longer time periods of operation at higher power output levels.

Therefore, some hybrid electric powertrains are configured to switch between electricpropulsion and combustion engine propulsion in dependence of the load such that theelectric propulsion system is operated in low load situations and the combustion engine isstarted and operated in higher load situations. Some hybrid electric powertrains areconfigured to allow simultaneous operation of the electric propulsion system and the combustion engine.

Most modern hybrid electric powertrains are capable of performing regenerative braking, inwhich at least part of the kinetic energy of the vehicle is converted into electric energy duringbraking of the vehicle. The electric energy can be stored in batteries, and/or capacitors, forsubsequent use for propulsion of the vehicle. ln this manner, the total energy efficiency of thevehicle can be improved, especially when driving in areas with many starts and stops, suchas when driving in urban areas. However, the energy saving potential of a hybrid electricpowertrain is limited, or even close to zero, when driving at constant higher speeds, such as during highway driving. 2 A further advantage of hybrid electric powertrains is that they can allow pure electricpropulsion system in certain areas, such as in city centres, and other areas sensitive toemission of exhaust gases, and/or emission of noise. Therefore, some hybrid electricpowertrains are arranged to shift between pure electric propulsion and pure combustionengine propulsion. This provides an advantage, especially for heavier vehicles, since thevehicle can be operated on pure electric drive when driving in certain areas, such as whendriving in urban areas, and can shift to operation using only the combustion engine whendriving at constant higher speeds, such as during highway driving. ln this manner, thepowertrain can generate low emission levels of exhaust gases and noise in sensitive areas,and the combustion engine is operated in load situations where it is most efficient, i.e. in high load situations. Moreover, the vehicle can be equipped with reasonably sized batteries. ln general, diesel engines have energy efficiency of up to 45% but more typically 30%, andpetrol engines of up to 40%, but more typically 20%. Accordingly, even when the engine isoperating at its point of maximum efficiency, most of the total heat energy released by thefuel consumed is emitted as heat without being turned into useful work, i.e. turning thecrankshaft. A large proportion of the waste heat is emitted in the form of hot exhaust gases.For this reason, some vehicles are equipped with a waste heat recovery system capable ofconverting waste heat into useful work. Most waste heat recovery systems operate in theRankine cycle and comprise a condenser, an exhaust gas heat exchanger, and an expander,wherein steam generated in the exhaust gas heat exchanger is converted into useful work bythe expander. The expander may comprise a turbine or one or more pistons and may beconnected to a shaft of the powertrain to supply useful work thereto. As an alternative, theexpander may be linked to an alternator to generate electricity. ln order to obtain a proper thermal efficiency of the waste heat recovery system, the condenser thereof must be cooled.

The above described vehicle systems are capable of improving energy efficiency of vehicles.However, they are also associated with some drawbacks, such as that they add cost andcomplexity to vehicles. For example, all the above described vehicle systems require cooling.That is, a combustion engine needs a combustion engine cooling system for cooling thecombustion engine, the electrical propulsion system needs a cooling system for coolingelectrical components thereof, and the waste heat recovery system needs a cooling systemfor cooling the condenser thereof. All these cooling systems must be designed in size andcapacity to provide sufficient cooling at the highest power output of the respective system.Thus, in most operating conditions, the size and capacity of the respective cooling system is greater than what is needed given the current power output of the vehicle system. Moreover, 3 all these cooling systems need hoses and one or more radiators arranged to radiate heat, which may pose problems given the limited space available at the vehicle.

Radiators are usually arranged at a front of a vehicle to be subjected to the air flowgenerated during driving of the vehicle. Moreover, radiators can be provided with one ormore cooling fans arranged to blow air through the radiators. ln this manner, an air flowthrough the radiators can be generated also when the vehicle is driving at low speed or is atstand still.

Supercharged combustion engines are usually provided with a charge air cooler arranged tocool air compressed by a supercharger of the combustion engine before the air is ducted toan inlet of the combustion engine. When the supercharger compresses the air, thetemperature of the air increases. By cooling the compressed air, the density of the airincreases and more air can be ducted into cylinders of the engine. ln this manner, the fuel efficiency and the performance of the combustion engine can be improved by cooling the air, and a higher degree of cooling of the air results in higher efficiency of the combustion engine.

Charge air coolers are usually also arranged at the front of a vehicle.

As understood from the above, the limited area at the front of vehicles poses a problem formodern vehicles which comprises various systems and subsystems having coolingrequirements. ln some cases, due to the limited space, one radiator can be arranged in frontof another radiator. lf so, the cooling efficiency of the radiator downstream may be reduced,because firstly, heat radiated from the radiator upstream may be partially transferred to theradiator downstream, and secondly, the radiator upstream may have a negative impact on the airflow, i.e. may partially hinder airflow, to the radiator downstream.

SUMMARYlt is an object of the present invention to overcome, or at least alleviate, at least some of the above-mentioned problems and drawbacks.

According to a first aspect of the invention, the object is achieved by a radiator assembly fora vehicle. The radiator assembly comprises an engine radiator, a charge air cooler, and oneor more low temperature radiators. The radiator assembly is configured to be subjected to aflow of air having a flow direction. The charge air cooler is arranged in front of the engineradiator seen in the flow direction. The charge air cooler comprises an inflow half portion andan outflow half portion, the inflow half portion having a higher temperature than the outflow half portion during operation of the charge air cooler. At least one radiator of the one or more 4 low temperature radiators superimposes a greater proportion of the inflow half portion than the outflow half portion seen in the flow direction.

Thereby, a radiator assembly is provided in which the at least one radiator of the one or morelow temperature radiators can be used to cool a vehicle system in an efficient manner. Thisbecause the at least one radiator of the one or more low temperature radiators is arrangedupstream of the charge air cooler relative the air flow direction. Moreover, since the at leastone radiator superimposes a greater proportion of the inflow half portion than the outflow halfportion of the charge air cooler, the at least one radiator will have a low impact on the coolingefficiency of the charge air cooler. This because the at least one radiator superimposes theinflow half portion having a higher temperature than the outflow half portion during operationof the charge air cooler, and because a greater proportion of the outflow half portion, which is cooler than the inflow half portion, is not faced with a radiator superimposing portions thereof.

Accordingly, a radiator assembly is provided capable of cooling an engine, at least onevehicle system, and compressed air in an efficient manner, while the space available at avehicle comprising the radiator assembly is utilized in an efficient manner. As a further resultthereof, the radiator assembly provides conditions for improved energy efficiency of a vehicle.

Accordingly, a radiator assembly is provided overcoming, or at least alleviating, at least someof the above-mentioned problems and drawbacks. As a result, the above-mentioned object is achieved. one or more low temperature radiators comprise a first low temperatureradiator arrangement and a second low temperature radiator. Thereby, a radiator assemblyis provided capable of cooling two or more vehicle systems in an efficient manner, in addition to the combustion engine and the supercharger arrangement. _ low temperature radiator superimposes the charge air coolerseen in the flow direction. Thereby, second low temperature radiator can be utilized to cool asecond vehicle system in an efficient manner, while the second low temperature radiator causes a low impact on the cooling efficiency of the charge air cooler.

Optionally, the first low temperature radiator arrangement comprises a first radiator unit anda second radiator unit. Thereby, the first low temperature radiator arrangement can be utilized to cool a first vehicle system in an efficient manner.

Optionally, the first radiator unit comprises a coolant outlet fluidly connected to a coolant inletof the second radiator unit. Thereby, the first low temperature radiator arrangement can beutilized to cool a first vehicle system in an efficient manner. Furthermore, since first radiatorunit comprises a coolant outlet fluidly connected to a coolant inlet of the second radiator unit,the second radiator unit will have a lower temperature than the first radiator unit during cooling of a vehicle system.

Optionally, the second radiator unit superimposes a greater proportion of the inflow halfportion than the outflow half portion seen in the flow direction. Thereby, the first lowtemperature radiator arrangement can be utilized to cool a first vehicle system in an efficientmanner, while causing a low impact on the cooling efficiency of the charge air cooler. Thisbecause the second radiator unit, which is cooler than the first radiator unit, superimposesthe inflow half portion of the charge air cooler, which has a higher temperature than theoutflow half portion during operation of the charge air cooler. Thus, in this manner, a lowamount of heat will be transferred from the second radiator unit to the charge air cooler during operation of the radiator assembly. , first low temperature radiator arrangement is arranged between the chargeair cooler and the engine radiator, seen in the flow direction. Thereby, the cooling efficiencyof the charge air cooler is further improved.

According to a second aspect of the invention, the object is achieved by a powertrain for avehicle. The powertrain comprises a combustion engine, a supercharger, an electricpropulsion system, and a radiator assembly according to some embodiments of the presentdisclosure, wherein the engine radiator is arranged to cool the combustion engine, thecharge air cooler is arranged to cool air compressed by the supercharger, and the one ormore low temperature radiators are arranged to cool at least a portion of the electric propulsion system.

Since the powertrain comprises a radiator assembly according to some embodiments, apowertrain is provided with a radiator assembly capable of cooling the combustion engine,compressed air, as well as at least a portion of the electric propulsion system in an efficientmanner, while the space available at a vehicle comprising the powertrain is utilized in an efficient manner. 6 Accordingly, a powertrain is provided overcoming, or at least alleviating, at least some of theabove-mentioned problems and drawbacks. As a result, the above-mentioned object is achieved.

Optionally, the powertrain is arranged to operate the combustion engine and the electricpropulsion system separately. Thereby, the at least one radiator superimposing the chargeair cooler will have a further lowered impact on the cooling efficiency of the charge air cooler.This because substantially no heat is transferred from the at least one radiator to the chargeair cooler when the combustion engine is operating. Thus, a powertrain is provided in whichat least a portion of the electric propulsion system can be cooled in an efficient manner,using the one or more low temperature radiators when the electric propulsion system isoperating, and in which compressed air can be cooled in an efficient manner using the charge air cooler when the combustion engine is operating.

Optionally, the first low temperature radiator arrangement is arranged to cool a first portion ofthe electric propulsion system, and the second low temperature radiator is arranged to cool asecond portion of the electric propulsion system. Thereby, a powertrain is provided capableof cooling a first and a second portion of the electric propulsion system in an efficientmanner, while the space available at a vehicle comprising the powertrain is utilized in an efficient manner.

Optionally, the first portion of the electric propulsion system comprises an electric machineand power electronics, and wherein the first low temperature radiator arrangement isarranged to cool at least one of the electric machine and the power electronics. Thereby, apowertrain is provided capable of cooling least one of the electric machine and the powerelectronics in an efficient manner, while the space available at a vehicle comprising the powertrain is utilized in an efficient manner.

Optionally, the second portion of the electric propulsion system comprises a battery.Thereby, a powertrain is provided capable of cooling the battery of the electric propulsionsystem in an efficient manner, while the space available at a vehicle comprising the powertrain is utilized in an efficient manner.

Optionally, the powertrain further comprises a waste heat recovery system comprising anexpander and a condenser, and wherein the condenser is arranged to be cooled by one ormore of the engine radiator, the first low temperature radiator arrangement, and the second low temperature radiator. Thereby, a powertrain is provided capable of cooling the condenser 7 of the waste heat recovery system in an efficient manner, while the space available at a vehicle comprising the powertrain is utilized in an efficient manner.

Optionally, the powertrain further comprises a set of valves arranged to allow a selection ofone or more of the engine radiator, the first low temperature radiator arrangement, and thesecond low temperature radiator as a cooling source for the condenser. Thereby, apowertrain is provided capable of utilizing one or more of the engine radiator, the first lowtemperature radiator arrangement, and the second low temperature radiator for cooling thecondenser of the waste heat recovery system. Due to these features, the energy efficiency of the powertrain can be improved.

Moreover, the combustion engine and the electric propulsion system of a hybrid electricpowertrain rarely operates simultaneously at high power levels. On the contrary, somepowertrains are arranged to operate the combustion engine and the electric propulsionsystem separately, which is the case according to some embodiments of the presentdisclosure. When the powertrain is operating the combustion engine at high power levels andthe electric propulsion system is inactive, the cooling demands of the combustion engine and of the condenser of the waste heat recovery system are high. ln these operating conditions, the cooling system of the electric propulsion system is notneeded for cooling the electric propulsion system since the electric propulsion system is notoperating. lnstead, in these operating conditions, the condenser of the waste heat recoverysystem can be cooled using one or more of the first low temperature radiator arrangement and the second low temperature radiator as a cooling source for the condenser. ln operating conditions where the powertrain is operating the electric propulsion system andthe combustion engine is inactive, there is no need for cooling the condenser of the wasteheat recovery system because the combustion engine and the waste heat recovery systemare inactive. Accordingly, the cooling system of the electric propulsion system can be usedfor cooling the electric propulsion system in some operating conditions and can be used forcooling the condenser of the waste heat recovery system in some other operating conditions.Moreover, in this manner, the need for an additional radiator is circumvented in a condensercoolant circuit and the available radiators of the powertrain can be utilized in a furtherefficient manner. ln addition, the space available at the front of a vehicle can be utilized in a further efficient manner. 8 Furthermore, due to these features, the condenser of the waste heat recovery system can besufficiently cooled over a wider operational range of the internal combustion engine, and in amanner independent of the temperature of coolant in an engine coolant circuit, which in turn improves the energy efficiency potential of the powertrain.

Optionally, the powertrain further comprises a set of valves, arranged to allow a selection oftwo or more of the engine radiator, the first low temperature radiator arrangement, and thesecond low temperature radiator, as a cooling source for the condenser. Thereby, thecondenser of the waste heat recovery system can be cooled in a further efficient manner andcan be cooled over a wider operational range of the internal combustion engine, which in turn improves the energy efficiency potential of the powertrain.

According to a third aspect of the invention, the object is achieved by a vehicle comprising a powertrain according to some embodiments of the present disclosure.

Since the vehicle comprises a powertrain according to some embodiments, a vehicle isprovided in which the combustion engine, compressed air, as well as at least a portion of theelectric propulsion system are cooled in an efficient manner, while the space available at the vehicle is utilized in an efficient manner.

Accordingly, a vehicle is provided overcoming, or at least alleviating, at least some of theabove-mentioned problems and drawbacks. As a result, the above-mentioned object is achieved.

Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGSVarious aspects of the invention, including its particular features and advantages, will bereadily understood from the example embodiments discussed in the following detailed description and the accompanying drawings, in which: Fig. 1 schematically illustrates a side view of a radiator assembly for a vehicle, according tosome embodiments Fig. 2 illustrates a front view of the radiator assembly illustrated in Fig. 1, Fig. 3 schematically illustrates a side view of a radiator assembly for a vehicle, according to some further embodiments, 9 Fig. 4 illustrates a front view of the radiator assembly illustrated in Fig. 3,Fig. 5 schematically illustrates a powertrain for a vehicle, according to some embodiments,and Fig. 6 illustrates a vehicle, according to some embodiments.

DETAILED DESCRIPTIONAspects of the present invention will now be described more fully. Like numbers refer to likeelements throughout. Well-known functions or constructions will not necessarily be described in detail for brevity and/or clarity.

Fig. 1 schematically illustrates a side view of a radiator assembly 4 for a vehicle, according tosome embodiments. The radiator assembly 4 comprises an engine radiator 46 arranged tocool a combustion engine and a charge air cooler 72 arranged to cool air compressed by asupercharger of the combustion engine. The charge air cooler 72 may also be referred to asan intercooler. The radiator assembly 4 further comprises a set of low temperature radiators70, 70', 74. As is further explained herein, the low temperature radiators 70, 70', 74 may bearranged to cool portions of an electric propulsion system. The radiator assembly 4 isconfigured to be subjected to a flow of air having a flow direction d. As is further explainedherein, the radiator assembly 4 may be configured to be arranged at a front area of a vehicleto be subjected to an airflow during driving of the vehicle. According to such embodiments,the flow direction d may be opposite to a fonNard direction of travel of the vehicle comprisingthe radiator assembly 4. As an alternative, or in addition, the radiator assembly 4 maycomprise one or more cooling fans arranged to selectively blow air through the radiator assembly 4 in the flow direction d.

As can be seen in Fig. 1, the charge air cooler 72 is arranged in front of the engine radiator46 seen in the flow direction d, i.e. upstream of the engine radiator 46 relative the flowdirection d. Moreover, according to the embodiments illustrated in Fig. 1, two radiators 70',74 of the set of low temperature radiators 70, 70', 74 are arranged in front of the charge aircooler 72 seen in the flow direction d, i.e. arranged upstream of the charge air cooler 72 relative the flow direction d.

According to the illustrated embodiments, the set of low temperature radiators 70, 70', 74comprises a first low temperature radiator arrangement 70, 70', and a second lowtemperature radiator 74. The first low temperature radiator arrangement 70, 70' comprises afirst radiator unit 70 and a second radiator unit 70". The first radiator unit 70 comprises a coolant outlet 77 fluidly connected to a coolant inlet 77' of the second radiator unit 70". Since the second radiator unit 70' is arranged downstream of the first radiator unit 70, the secondradiator unit 70' will have a lower temperature than the first radiator unit 70 during operation of the radiator assembly 4.

Fig. 2 i||ustrates a front view of the radiator assembly 4 illustrated in Fig. 1. ln Fig. 2, theradiator assembly 4 is illustrated as seen in the flow direction d indicated in Fig .1. Asindicated in Fig. 2, the charge air cooler 72 comprises an inflow half portion 72' and anoutflow half portion 72". The inflow half portion 72' comprises an inlet and the outflow halfportion 72" comprises an outlet. During operation of the charge air cooler 72, compressedgas is flowing into the charge air cooler 72 via the inlet and out from the charge air cooler 72via the outlet. ln the charge air cooler 72, the compressed air is flowing from the inflow halfportion 72' to the outflow half portion 72". The compressed air is cooled when flowingthrough the charge air cooler 72. Therefore, the inflow half portion 72' will have a higher temperature than the outflow half portion 72" during operation of the charge air cooler 72.

As can be seen in Fig. 2, each of the second low temperature radiator 74 and the secondradiator unit 70' superimposes a greater proportion of the inflow half portion 72' than theoutflow half portion 72" seen in the flow direction d. With other words, each of the second lowtemperature radiator 74 and the second radiator unit 70' covers a greater proportion of theinflow half portion 72' than the outflow half portion 72" seen in the flow direction d. ln thismanner, these radiators 74, 70' can be used to efficiently cool a vehicle system, while theimpact on the cooling efficiency of the charge air cooler 72 is kept low. This because each ofthe second low temperature radiator 74 and the second radiator unit 70' superimposes agreater proportion of the inflow half portion 72', which has a higher temperature than theoutflow half portion 72", and because a greater proportion of the outflow half portion 72",which is cooler than the inflow half portion 72', is not faced with a radiator 74, 70' superimposing portions thereof.

The charge air cooler 72 is provided with a total surface area substantially perpendicular tothe flow direction. The wording "half portion" as used herein is intended to encompass aportion of the charge air cooler 72 which has a surface area that is half the total surface areaof the charge air cooler 72. Thus, according to the embodiments illustrated in Fig. 2, theinflow half portion 72' and the outflow half portion 72" of the charge air cooler 72 together have a surface area equal to the total surface area of the charge air cooler 72.

Fig. 3 schematically i||ustrates a side view of a radiator assembly 4 for a vehicle, according to some further embodiments. The radiator assembly 4 according to the embodiments 11 illustrated in Fig. 3 comprises the same features, functions, and advantages as the radiatorassembly 4 according to the embodiments illustrated in Fig. 1 and Fig. 2, with some differences explained below.

According to the embodiments illustrated in Fig. 3, the first low temperature radiatorarrangement 70, 70' is arranged between the charge air cooler 72 and the engine radiator46, seen in the flow direction d. However, also in these embodiments, second lowtemperature radiator 74 is arranged in front of the charge air cooler 72 seen in the flow direction d, i.e. arranged upstream of the charge air cooler 72 relative the flow direction d.

According to the illustrated embodiments, the radiator assembly 4 is arranged to besubjected to a flow of air having a flow direction d straight towards extension planes of theradiators 46, 70, 70', 72, 74 of the radiator assembly 4. That is, according to the illustratedembodiments, the extension plane of each radiator 46, 70, 70', 72, 74 of the radiatorassembly 4 is perpendicular to the flow direction d. According to further embodiments, one ormore of the radiator 46, 70, 70', 72, 74 may be arranged such that the extension plane thereof is angled at an angle within the range of 40 - 90 degrees relative the flow direction d.

Fig. 4 illustrates a front view of the radiator assembly 4 illustrated in Fig. 3. ln Fig. 4, theradiator assembly 4 is illustrated as seen in the flow direction d indicated in Fig .3. As can beseen in Fig. 4, the second low temperature radiator 74 superimposes a greater proportion ofthe inflow half portion 72' of the charge air cooler 72 than the outflow half portion 72" seen inthe flow direction d. ln this manner, the second low temperature radiator 74 can be used toefficiently cool a vehicle system, while the impact on the cooling efficiency of the charge aircooler 72 is kept low. This because the second low temperature radiator 74' superimposes agreater proportion of the inflow half portion 72', which has a higher temperature than theoutflow half portion 72", and because a greater proportion of the outflow half portion 72",which is cooler than the inflow half portion 72', is not faced with a radiator 74 superimposing portions thereof.

Moreover, in comparison to the embodiments illustrated in Fig. 1 and Fig. 2, the coolingefficiency of the charge air cooler 72 is improved because none of the radiators 70, 70' of thefirst low temperature radiator arrangement 70, 70' superimposes the charge air cooler 72 in the flow direction d.

Moreover, according to the embodiments illustrated in Fig. 3 and Fig. 4, none of the second low temperature radiator 74 and the charge air cooler 72 superimposes the first radiator unit 12 70 of the first low temperature radiator arrangement 70, 70' seen in the flow direction d. As aresult, the first low temperature radiator arrangement 70, 70' can be used to cool a vehiclesystem in an efficient manner, while the cooling efficiency of the charge air cooler 72 is improved.

Fig. 5 schematically illustrates a powertrain 1 for a vehicle, according to some embodiments.According to the illustrated embodiments, the powertrain 1 is a hybrid electric powertrain 1configured provide motive power to a vehicle comprising the powertrain 1. The powertrain 1comprises a combustion engine 5. The combustion engine 5, as referred to herein, may bean internal combustion engine such as for example a compression ignition engine, such as adiesel engine, or an Otto engine with a spark-ignition device, wherein the Otto engine may be configured to run on gas, petrol, alcohol, similar fuels, or combinations thereof.

The powertrain 1 comprises a radiator assembly 4. The radiator assembly 4 comprises anengine radiator 46, a charge air cooler 72, a first low temperature radiator arrangement 70,70', and a second low temperature radiator 74. The radiator assembly 4 is configured to besubjected to a flow of air having a flow direction d, i.e. an air flow direction d. Throughout thisdisclosure, the wording "flow direction d" may be replaced by the wording "air flow directiond". According to the embodiments illustrated in Fig. 5, the first low temperature radiatorarrangement 70, 70' is arranged between the charge air cooler 72 and the engine radiator46, seen in the flow direction d. Moreover, the second low temperature radiator 74 isarranged in front of the charge air cooler 72 seen in the flow direction d, i.e. arrangedupstream of the charge air cooler 72 relative the flow direction d. The radiator assembly 4may be a radiator assembly 4 according to the embodiments illustrated in Fig. 3 and Fig. 4.According to further embodiments, the powertrain 1 may comprise a radiator assembly 4 according to the embodiments illustrated in Fig. 1 and Fig. 2.

The powertrain 1 comprises an engine coolant circuit 6 arranged to cool the combustionengine 5. The engine coolant circuit 6 comprises the engine radiator 46 and a coolant pump49 arranged to pump coolant through the engine coolant circuit 6. The engine radiator 46 is thus arranged to cool the combustion engine 5.

The powertrain 1 comprises a supercharger 73 configured to compress air to an inlet of thecombustion engine. The supercharger 73 may comprise one or more turbochargers and/orone or more compressors which may be driven by a torque originating from a crankshaft ofthe combustion engine 5. The charge air cooler 72 is arranged to cool air compressed by the supercharger 73. 13 The powertrain 1 comprises a waste heat recovery system 7. According to the illustratedembodiments, the waste heat recovery system 7 comprises an expander 15, a condenser17, an expansion tank 83, a working media pump 85, and a heat collector 81. The heatcollector 81 may also be referred to as a boiler or an evaporator. The working media pump85 is arranged to pump working media through the waste heat recovery system 7. The heatcollector 81 may for example be arranged in an exhaust pipe of the combustion engine 5 andmay be arranged to transfer heat from exhaust gasses of the combustion engine 5 to theworking media of the waste heat recovery system 7. ln the heat collector 81, the workingmedia is heated to a temperature in which the working media evaporates from liquid phaseinto gaseous phase. The gaseous working media is transferred to the expander 15. ln theexpander 15, the temperature and the pressure of the working media is partially convertedinto useful work. According to the illustrated embodiments, a rotor of the expander 15 ismechanically connected to a crankshaft of the combustion engine 5, via a transmission 87.According to further embodiments, the expander 15 may provide useful work in another manner, such as for example by driving an alternator producing electricity.

The working media of the waste heat recovery system 7 flows out from the expander 15 andinto the condenser 17. ln the condenser 17, the temperature of the working media is furtherreduced, and gaseous working media is condensed back into liquid phase. From thecondenser 17, the working media is pumped to the heat collector 81 by the working mediapump 85. The expansion tank 83 acts as a reservoir holding working media and acts as apressure reservoir for the working media in the waste heat recovery system 7, which mayfacilitate condensation of working media also in cases where it is difficult to lower the temperature of the working media in a sufficient manner.

Moreover, according to the illustrated embodiments, the powertrain 1 comprises an electricpropulsion system 9, 11, 13 configured to, at least selectively, provide motive power to avehicle comprising the powertrain 1. The first low temperature radiator arrangement 70, 70' isarranged to cool a first portion 9, 13 of the electric propulsion system 9, 11, 13 via a firstcoolant circuit 23. According to the illustrated embodiments, the first portion 9, 13 of theelectric propulsion system 9, 11, 13 comprises an electric machine 9 and power electronics13. Thus, according to the illustrated embodiments, the first low temperature radiatorarrangement 70, 70' is arranged to cool the electric machine 9 and the power electronics 13 via the first coolant circuit 23. 14 Moreover, according to the illustrated embodiments, the second low temperature radiator 74is arranged to cool a second portion 11 of the electric propulsion system 9, 11, 13 via asecond coo|ant circuit 25. According to the illustrated embodiments, the second portion 11 ofthe electric propulsion system 9, 11, 13 comprises a battery 11. The battery 11 is arranged tosupply electricity to the electric machine 9 by an amount controlled by the power electronics13. Thus, according to the illustrated embodiments, the second low temperature radiator 74 is arranged to cool the battery 11 via the second coo|ant circuit 25.

As explained herein, it is rare that the combustion engine 5 and the electric propulsionsystem 9, 11, 13 operates simultaneously, or at least with high power output from bothsystems simultaneously. ln addition, according to some embodiments of the presentdisclosure, the powertrain 1 is arranged to operate the combustion engine 5 and the electricpropulsion system 9, 11, 13 separately. ln operating conditions where the powertrain 1 isoperating the combustion engine 5 and the electric propulsion system 9, 11, 13 is inactive,no heat is generated by the components 9, 11, 13 of the electric propulsion system 9, 11, 13,and consequently no heat is to be radiated from the first low temperature radiatorarrangement 70, 70' and from the second low temperature radiator 74. As a result, theengine radiator 46 can be used to cool the combustion engine 5 in an efficient manner and the charge air cooler 72 can be used to cool compressed air in an efficient manner.

As is further explained herein, according to the illustrated embodiments, the condenser 17 ofthe waste heat recovery system 7 is arranged to be cooled by one or more of the engineradiator 46, the first low temperature radiator arrangement 70, 70', and the second lowtemperature radiator 74. Moreover, as is explained in detail herein, the powertrain 1comprises a set of valves 31, 37, 61, 63 arranged to allow a selection of one or more of theengine radiator 46, the first low temperature radiator arrangement 70, 70', and the second low temperature radiator 74, as a cooling source for the condenser 17.

According to the illustrated embodiments, the condenser 17 is arranged to be cooled bycoo|ant flowing through a portion 21 of the engine coo|ant circuit 6. Furthermore, thepowertrain 1 comprises a heat exchanger arrangement 27, 29 configured to exchange heatbetween the portion 21 of the engine coo|ant circuit 6 and the first and second coo|antcircuits 23, 25. ln this manner, a powertrain 1 is provided capable of utilizing the first andsecond coo|ant circuits 23, 25 of the electric propulsion system 9, 11, 13 for cooling the condenser 17 of the waste heat recovery system 7.

The first coolant circuit 23 comprises a coolant pump 24 arranged to pump coolant throughthe first coolant circuit 23. The coolant pump 24 may be powered by an electric motor. Asmentioned, the first coolant circuit 23 further comprises the first low temperature radiatorarrangement 70, 70' arranged to radiate heat from, i.e. cool, coolant in the first coolant circuit23. Moreover, as mentioned, the first low temperature radiator arrangement 70, 70'comprises two radiators 70, 70' arranged in series. The two radiators 70, 70' may becombined in a u-flow radiator or similar. According to further embodiments, the first lowtemperature radiator arrangement 70, 70' may comprise one radiator. Moreover, according tothe illustrated embodiments, the first coolant circuit 23 is arranged to cool a cabin heatercondenser 90, an electrical air compressor system 92, and a condenser 94 of a battery refrigeration circuit 93.

According to the illustrated embodiments, the heat exchanger arrangement 27, 29 comprisesa first heat exchanger 27 configured to exchange heat between the portion 21 of the enginecoolant circuit 6 and the first coolant circuit 23. As can be seen in Fig. 5, the first heatexchanger 27 is arranged upstream of the condenser 17 in the portion 21 of the enginecoolant circuit 6. ln this manner, coolant flowing through the portion 21 of the engine coolantcircuit 6 can be further cooled, by the first heat exchanger 27, before the coolant is flowing tothe condenser 17. Accordingly, the first coolant circuit 23 can be utilized to cool the condenser 17 in an efficient manner.

The first coolant circuit 23 comprises a first valve 31. The first valve 31 is arranged toregulate the flow of coolant through the first heat exchanger 27. Moreover, the first coolantcircuit 23 comprises a first coolant branch 33. The first heat exchanger 27 is arranged in thefirst coolant branch 33 of the first coolant circuit 23. According to the embodiments illustratedin Fig. 5, the first coolant branch 33 comprises a branch inlet 35 arranged downstream of theelectric machine 9 and the power electronics 13. ln these embodiments, the first valve 31comprises a first outlet 31' fluidly connected to a return line 34. The return line 34 is fluidlyconnected to the radiator arrangement 70, 70' in a manner bypassing the first heatexchanger 27. The first valve 31 comprises a second outlet 31 " fluidly connected to thebranch inlet 35. The first valve 31 is an electronically controlled valve which can be controlledto a first state in which the first valve 31 supplies coolant to the first outlet 31' and blockscoolant from flowing through the second outlet 31", and a second state in which the firstvalve 31 supplies coolant to the second outlet 31 " and blocks coolant from flowing throughthe first outlet 31 '_ Furthermore, the first valve 31 may allow a gradual control of flow throughthe first and second outlets 31', 31 ln this manner, the flow rate of coolant flowing through the first heat exchanger 27 can be regulated with high degree of control. 16 Furthermore, as explained above, it is rare that the combustion engine 5 and the electricpropulsion system 9, 11, 13 operates simultaneously, or at least with high power output fromboth systems simultaneously. ln addition, according to some embodiments of the presentdisclosure, the powertrain 1 is arranged to operate the combustion engine 5 and the electricpropulsion system 9, 11, 13 separately. Thus, in operating conditions where the powertrain 1is operating the combustion engine 5 and the electric propulsion system 9, 11, 13 is inactive,the components 9, 11, 13 of the electric propulsion system 9, 11, 13 generates no heat.Thereby, it is ensured that coolant having a low temperature can be supplied to the first heatexchanger 27, via the first coolant circuit 23, to cool the condenser 17. ln operatingconditions where the powertrain 1 is operating the electric propulsion system 9, 11, 13 andthe combustion engine 5 is inactive, the first coolant circuit 23 can be used to coolcomponents 9, 13 of the electric propulsion system 9, 11, 13 in an efficient manner. ln theseoperating conditions, there is no need for cooling the condenser 17 of the waste heatrecovery system 7 because the combustion engine 5 and the waste heat recovery system 7 are inactive.

According to further embodiments, the first coolant branch 33 may comprise a branch inlet35 arranged upstream of the electric machine 9 and the power electronics 13. ln this manner,heat can be exchanged from the portion 21 of the engine coolant circuit 6 to the first coolantcircuit 23 without significantly affecting the temperature and the cooling performance of theelectric machine 9 and the power electronics 13. Furthermore, it is ensured that coolant having a low temperature is supplied to the first heat exchanger 27.

According to some embodiments of the present disclosure, the first valve 31 may bepositioned at another position in the first coolant circuit 23, than at the branch inlet 35 of thefirst coolant branch 33, and still achieve all, or some of, the above described functions. As an example, the first valve 31 may be positioned at a branch outlet of the first coolant branch 33.

As mentioned, the second coolant circuit 25 further comprises the second low temperatureradiator 74 arranged to radiate heat from, i.e. cool, coolant in the second coolant circuit 25.The second coolant circuit 25 comprises a coolant pump 26 arranged to pump coolantthrough the second coolant circuit 25. The coolant pump 26 may be powered by an electricmotor. Moreover, according to the illustrated embodiments, the heat exchanger arrangement27, 29 comprises a second heat exchanger 29 arranged to exchange heat between theportion 21 of the engine coolant circuit 6 and the second coolant circuit 25. As can be seen in Fig. 5, the second heat exchanger 29 is arranged upstream of the condenser 17 in the 17 portion 21 of the engine coolant circuit 6. ln this manner, coolant flowing through the portion21 of the engine coolant circuit 6 can be further cooled, by the second heat exchanger 29,before the coolant is flowing to the condenser 17. Accordingly, the second coolant circuit 25 can be utilized to cool the condenser 17 in an efficient manner.

The second coolant circuit 25 comprises a second valve 37. The second valve 37 isarranged to regulate the flow of coolant through the second heat exchanger 29. Moreover,the second coolant circuit 25 comprises a second coolant branch 39, wherein the secondheat exchanger 29 is arranged in the second coolant branch 39. The second coolant branch39 comprises a branch inlet 41 arranged upstream of the battery 11 and a branch outletdownstream of the battery 11. ln this manner, heat can be exchanged from the portion 21 ofthe engine coolant circuit 6 to the second coolant circuit 25 without significantly affecting the temperature and the cooling performance of the battery 11.

Moreover, according to the illustrated embodiments, the second valve 37 is positioned at thebranch inlet 41 of the second coolant branch 39 and comprises a first outlet 37' fluidlyconnected to coolant portions of the battery 11 and a second outlet 37" fluidly connected tothe branch inlet 41 of the second coolant branch 39. According to the illustratedembodiments, the second valve 37 is an electronically controlled valve which can becontrolled to a first state in which the second valve 37 supplies coolant to the first outlet 37'and blocks coolant from flowing through the second outlet 37", and a second state in whichthe second valve 37 supplies coolant to the second outlet 37" and blocks coolant fromflowing through the first outlet 37". Furthermore, the second valve 37 may allow a gradualcontrol of flow through the first and second outlets 37', 37". ln this manner, the flow rate ofcoolant flowing through the second heat exchanger 29 can be regulated with high degree of control. ln operating conditions where the powertrain 1 is operating the electric propulsion system 9,11, 13 and the combustion engine 5 is inactive, the second valve 37 may be controlled topositions where second valve 37 mainly controls coolant flow to the first outlet 37". ln thismanner, the battery 11 can be efficiently cooled by the second coolant circuit 25. However, ifthe cooling demand of the battery 11 is low, the second valve 37 may also be controlled topositions where second valve 37 controls coolant flow to the second outlet 37" so as tototally or partially bypass the battery 11. Moreover, in operating conditions where thepowertrain 1 is operating the combustion engine 5 and the electric propulsion system 9, 11, 13 is inactive, the second valve 37 may be controlled to positions where second valve 37 18 mainly controls coolant flow to the second outlet 37". ln this manner, the condenser 17 of the waste heat recovery system 7 is efficiently cooled by the second coolant circuit 25.

The second valve 37 may be positioned at another position in the second coolant circuit 25,than at the branch inlet 41 of the second coolant branch 39, and still achieve all, or some of,the above described functions. As an example, the second valve 37 may be positioned at a branch outlet of the second coolant branch 39.

As indicated above, according to the illustrated embodiments, the powertrain 1 furthercomprises a battery refrigeration circuit 93. The battery refrigeration circuit 93 is arranged tofurther lower the temperature of coolant in the second coolant circuit 25. The batteryrefrigeration circuit 93 comprises a compressor 98, a condenser 94, an expansion valve 95,and an evaporator 96. The evaporator 96 may also be referred to as a chiller. Thecompressor 98 compresses working media in the battery refrigeration circuit 93. Thecompressed working media is partially cooled by the condenser 94. Then, the working mediais expanded by the expansion valve 95. As a result, the temperature of the working media issignificantly reduced. The working medium cools coolant of the second coolant circuit 25upon evaporation in the evaporator 96. ln this manner, it can be ensured that the battery 11is sufficiently cooled also in high load situations and in situations with high ambient temperatures.

As can be seen in Fig. 5, the evaporator 96 of the battery refrigeration circuit 93 is arrangedupstream of the branch inlet 41 of the second coolant branch 39. ln this manner, the batteryrefrigeration circuit 93 can also be utilized for further cooling the condenser 17 of the waste heat recovery system 7. Thereby, condensation of working medium in the condenser 17 canbe further ensured even at higher load situations of the combustion engine 5 and of the waste heat recovery system 7.

Moreover, as can be seen in Fig. 5, the second coolant circuit 25 comprises a heater 44arranged in a bypass line bypassing the second low temperature radiator 74 of the secondcoolant circuit 25. The heater 44 can be used to heat coolant of the second coolant circuit 25in order to heat the battery 11 when needed, such as at cold starts at lower ambient temperatures.

According to the illustrated embodiments, the portion 21 of the engine coolant circuit 6, asreferred to therein, is an engine coolant branch 45 of the engine coolant circuit 6. The engine coolant branch 45 comprises a branch inlet 47 arranged downstream of the engine radiator 19 46 and upstream of a coolant inlet 48 of the combustion engine 5. Thereby, it is ensured thatcoolant having a low temperature is flowing into the engine coolant branch 45 towards the condenser 17.

The engine coolant circuit 6 further comprises a radiator line 51 arranged to conduct coolantto the engine radiator 46 and a bypass line 53 arranged to conduct coolant past the engineradiator 46. Moreover, the engine coolant circuit 6 comprises a first valve device 55 arrangedto receive coolant from a coolant line 57 of the engine coolant circuit 6 and direct the coolantto the radiator line 51 and the bypass line 53. The first valve device 55 may comprise aconventional thermostat. As indicated in Fig. 5, the coolant line 57 may be fluidly connectedto a coolant outlet of the combustion engine 5. According to the illustrated embodiments, theengine coolant circuit 6 comprises a second valve device 61 arranged to receive coolantfrom the bypass line 53 and direct at least part of coolant flow from the bypass line 53 to thebranch inlet 47. Thus, in situations where the first valve device 55 directs coolant to thebypass line 53, such as when coolant at the first valve device 55 is lower than a thresholdtemperature, coolant can flow from the coolant line 57, through the bypass line 53 and the second valve device 61, and into the engine coolant branch 45, via the branch inlet 47.

Moreover, as indicated in Fig. 5, the engine coolant circuit 6 comprises a radiator outlet line59 arranged to conduct at least part of coolant flow from the engine radiator 46 to the branchinlet 47. Thereby, in situations where the first valve device 55 directs coolant to the radiatorline 51, such as when coolant at the first valve device 55 is higher than a thresholdtemperature, coolant can flow from the coolant line 57, through the radiator line 51 into theengine radiator 46, and out from the engine radiator 46 through the radiator outlet line 59 intothe into the engine coolant branch 45, via the branch inlet 47. Accordingly, in this manner, itcan be ensured that coolant having a low temperature is ducted into the portion 21 of the engine coolant circuit 6 regardless of the opening state of the first valve device 55.

The engine coolant branch 45 comprises a branch outlet 47' connected to an inlet of thecoolant pump 49 of the engine coolant circuit 6. Thus, according to the illustratedembodiments, coolant flowing into the branch inlet 47 flows through the second heatexchanger 29 and through the first heat exchanger 27 where the temperature of the coolantcan be reduced by the first and second coolant circuits 23, 25 respectively. Then, the coolantflows through the condenser 17 of the waste heat recovery system 7 to cool and condensateworking media in the waste heat recovery system 7. The coolant is ducted from thecondenser 17 to the inlet of the coolant pump 49 of the engine coolant circuit 6 from where it is further pumped through the engine coolant circuit 6. ln addition, according to the illustrated embodiments, the engine coolant branch 45comprises a third valve device 63 and a branch bypass line 65 connecting portions of theengine coolant branch 45. The third valve device 63 is controllable to a position in which flowof coolant is allowed through the branch bypass line 65 so as to form a separate coolantcircuit through the branch bypass line 65 and the engine coolant branch 45. According to theillustrated embodiments, when the third valve device 63 is in this position, the third valvedevice 63 blocks flow of coolant from the branch inlet 47 and instead allows flow of coolantthrough the branch bypass line 65. Moreover, as can be seen in Fig. 2, the engine coolantbranch 45 comprises a coolant pump 43. The coolant pump 43 is arranged such that thecoolant pump 43 can pump coolant through the separate coolant circuit formed by the branchbypass line 65 and the engine coolant branch 45. ln this manner, heat exchange can occurbetween the condenser 17 of the waste heat recovery system 7 and the first and secondheat exchangers 27, 29 in a manner independent of the rest of the engine coolant circuit 6, and thus also in a manner independent of the cooling of the combustion engine 5.

Accordingly, due to these features, the condenser 17 can be cooled using the first andsecond coolant circuit 23, 25 in a manner independent of the cooling of the combustionengine 5 and different temperatures of coolant is allowed in the engine coolant branch 45and in the rest of the engine coolant circuit 6. As a further result, it can be ensured that the combustion engine 5 obtains sufficient cooling during high load operating conditions.

According to some embodiments of the present disclosure, the powertrain 1 comprises acontrol unit configured to control operation of one or more pumps 24, 26, 43, 85 of thepowertrain 1, and/or configured to control opening states of one or more valves 31, 37, 55,61, 63 of the powertrain 1. The control unit may be configured to control operation of the oneor more pumps 24, 26, 43, 85, and/or to control opening states of one or more valves 31, 37,55, 61, 63, in dependence of the operating state of the combustion engine 5, the waste heatrecovery system 7, and/or the electric propulsion system 9, 11, 13, as well as in dependenceof a current, or predicted, cooling demand of one or more components 5, 9, 11, 13, 17 of thepowertrain 1. Moreover, due to these features, the control unit may select, one or more, ortwo or more, of the engine radiator 46, the first low temperature radiator arrangement 70, 70',and the second low temperature radiator 74, as a cooling source for the condenser 17. Such a control unit is not illustrated in Fig. 5 for the reason of brevity and clarity.

Fig. 6 illustrates a vehicle 3 according to some embodiments. The vehicle 3 comprises a powertrain 1 according to the embodiments illustrated in Fig. 5. The powertrain 1 is arranged 21 to provide motive power to the vehicle 3, via wheels 99 of the vehicle 3. As can be seen in Fig. 6, the radiator assembly 4 of the vehicle 3 is arranged at a front area of the vehicle 3.

According to the illustrated embodiments, the vehicle 3 is a truck. However, according tofurther embodiments, the vehicle 3, as referred to herein, may be another type of manned orunmanned vehicle for land or water based propulsion such as a lorry, a bus, a construction vehicle, a tractor, a car, a ship, a boat, or the like. lt is to be understood that the foregoing is illustrative of various example embodiments andthat the invention is defined only by the appended claims. A person skilled in the art willrealize that the example embodiments may be modified, and that different features of theexample embodiments may be combined to create embodiments other than those describedherein, without departing from the scope of the present invention, as defined by the appended claims.

As used herein, the term "comprising" or "comprises" is open-ended, and includes one ormore stated features, elements, steps, components or functions but does not preclude thepresence or addition of one or more other features, elements, steps, components, functions or groups thereof.

Claims

1.A radiator assembly (4) for a vehicle (3), wherein the radiator assembly (4) comprises:- an engine radiator (46),- a charge air cooler (72), and- one or more low temperature radiators (70, 70', 74),wherein the radiator assembly (4) is configured to be subjected to a flow of airhaving a flow direction (d),wherein the charge air cooler (72) is arranged in front of the engine radiator(46) seen in the flow direction (d),wherein the charge air cooler (72) comprises an inflow half portion (72”) and anoutflow half portion (72”), the inflow half portion (72”) having a higher temperaturethan the outflow half portion (72”) during operation of the charge air cooler (72), andwherein at least one radiator (70', 74) of the one or more low temperatureradiators (70, 70', 74) superimposes a greater proportion of the inflow half portion(72”) than the outflow half portion (72”) seen in the flow direction (d).

2. The radiator assembly (4) according to claim 1, wherein the one or more lowtemperature radiators (70, 70', 74) comprise: - a first low temperature radiator arrangement (70, 70'), and - a second low temperature radiator (74).

3. The radiator assembly (4) according to claim 2, wherein the second low temperatureradiator (74) superimposes the charge air cooler (72) seen in the flow direction (d).

4. The radiator assembly (4) according to claim 2 or 3, wherein the first low temperatureradiator arrangement (70, 70') comprises a first radiator unit (70) and a second radiatorunit (70').

5. The radiator assembly (4) according to claim 4, the first radiator unit (70) comprises acoolant outlet (77) fluidly connected to a coolant inlet (77”) of the second radiator unit(70”).

6. The radiator assembly (4) according to claim 4 or 5, wherein the second radiator unit(70”) superimposes a greater proportion of the inflow half portion (72”) than the outflowhalf portion (72”) seen in the flow direction (d).

7. The radiator assembly (4) according to claim 3, wherein the first low temperature radiatorarrangement (70, 70') is arranged between the charge air cooler (72) and the engineradiator (46), seen in the flow direction (d).

8. A powertrain (1) for a vehicle (3), wherein the powertrain (1) comprises: - a combustion engine (5), - a supercharger (73), - an electric propulsion system (9, 11, 13), and - a radiator assembly (4) according to any one of the claims 1 - 7, wherein the engine radiator (46) is arranged to cool the combustion engine (5), the charge air cooler (72) is arranged to cool air compressed by the supercharger(73), and the one or more low temperature radiators (70, 70', 74) are arranged tocool at least a portion (9, 11, 13) of the electric propulsion system.

9. The powertrain (1) according to claim 8, wherein the powertrain (1) is arranged tooperate the combustion engine (5) and the electric propulsion system (9, 11, 13)separately.

10. The powertrain (1) according to claim 8 or 9, wherein the powertrain (10) comprises aradiator assembly (4) according to claim 2, wherein the first low temperature radiatorarrangement (70, 70') is arranged to cool a first portion (9, 13) of the electric propulsionsystem (9, 11, 13), and the second low temperature radiator (74) is arranged to cool asecond portion (11) of the electric propulsion system (9, 11, 13).

11. . The powertrain (1) according to claim 10, wherein the first portion (9, 13) of the electric propulsion system (9, 11, 13) comprises an electric machine (9) and power electronics(13), and wherein the first low temperature radiator arrangement (70, 70') is arranged tocool at least one of the electric machine (9) and the power electronics (13).

12. The powertrain (1) according to claim 10 or 11,wherein the second portion (11) of theelectric propulsion system (9, 11, 13) comprises a battery (11).

13. The powertrain (1) according to any one of the claims 10 - 12, wherein the powertrain (1)further comprises a waste heat recovery system (7) comprising an expander (15) and acondenser (17), and wherein the condenser (17) is arranged to be cooled by one ormore of the engine radiator (46), the first low temperature radiator arrangement (70, 70”),and the second low temperature radiator (74).

14. The powertrain (1) according to claim 13, wherein the powertrain (1) further comprises aset of valves (31, 37, 61, 63) arranged to allow a selection of one or more of the engineradiator (46), the first low temperature radiator arrangement (70, 70”), and the second 5 low temperature radiator (74) as a cooling source for the condenser (17).

15. The powertrain (1) according to claim 13, wherein the powertrain (1) further comprises aset of valves (31, 37, 61, 63) arranged to allow a selection of two or more of the engineradiator (46), the first low temperature radiator arrangement (70, 70”), and the second 10 low temperature radiator (74) as a cooling source for the condenser (17).

16. A vehicle (3) comprising a powertrain (1) according to any one of the claims 8 - 15.