Patent Publication Number: US-2023158883-A1

Title: Thermal management system, and vehicle

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a National Stage patent application (filed under 35 § U.S.C. 371) of PCT/SE2021/050381, filed Apr. 26, 2021, of the same title, which, in turn claims priority to Swedish Patent Application No. 2050488-2 filed Apr. 29, 2020, of the same title; the contents of each of which are hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present disclosure relates to a vehicle thermal management system comprising a first and a second coolant circuit each comprising a coolant pump. The present disclosure further relates to a vehicle comprising a vehicle thermal management system. 
     BACKGROUND 
     Modern vehicles usually comprise several cooling circuits each arranged to cool a vehicle system such as a combustion engine, an electric propulsion system, a propulsion battery, a retarder, a waste heat recovery circuit, and the like. Such cooling circuits usually comprise a coolant pump and one or more radiators arranged to transfer heat from the cooling circuit to ambient air. Radiators are usually arranged at a front of a vehicle to be subjected to the air flow generated during driving of the vehicle. Moreover, radiators can be provided with one or more cooling fans arranged to blow air through the radiators. In this manner, an air flow through the radiators can be generated also when the vehicle is driving at low speed or is at stand still. 
     A problem associated with coolant circuits is that air may enter the circuit. Air in a coolant circuit reduces the efficiency of the coolant circuit, partly because air has a much lower specific heat capacity than coolant. Moreover, air inside a coolant circuit may harm components of the coolant circuit, such as the coolant pump of the coolant circuit. 
     Technical development has led to an increased number of systems and components packed into vehicles. For example, the current trend of electrification of vehicles has increased this number significantly. The increased number of systems and components packed into vehicles add costs and complexity to the vehicle. Moreover, the mounting, fitting, and access of the systems and components can be problematic due to the limited available space in vehicles. 
     Furthermore, the increased number of systems and components packed into vehicles has led to an increased number of coolant circuits arranged in vehicles. Each of these coolant circuits are usually arranged to cool a vehicle system or a set of vehicle systems, wherein each coolant circuit is arranged to operate in an independent manner relative to the other coolant circuits. This entails that each of the coolant circuits must be designed to have a capacity sufficient for cooling or heating at a respective peak power, which adds to the problems of added costs, complexity, and limited available space in vehicles. 
     Moreover, generally, on today&#39;s consumer market, it is an advantage if vehicles and their associated components, systems and arrangements have conditions and/or characteristics suitable for being manufactured and assembled in a cost-efficient manner. 
     SUMMARY OF THE INVENTION 
     It 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 vehicle thermal management system comprising a first and a second coolant circuit each comprising a coolant pump. The first coolant circuit comprises a coolant duct configured to conduct coolant flow through a portion of the first coolant circuit and an expansion tank connected to the coolant duct. The system further comprises a first connecting conduit connecting the second coolant circuit to the coolant duct. The system comprises a valve controllable between a first state in which the valve hinders flow of fluid through the first connecting conduit and a second state in which the valve allows flow of fluid through the first connecting conduit to deair the second coolant circuit via the expansion tank. 
     Since the thermal management system comprises the first connecting conduit and the valve controllable between the first and second states, a system is provided having conditions for deairing the second coolant circuit via the expansion tank simply by controlling the valve to the second state. Moreover, since the expansion tank is connected to the coolant duct, the first coolant circuit is also deaired via the expansion tank. In this manner, it can be ensured that the coolant pumps of the first and second coolant circuits are fed with coolant and not air. Thereby, damage of the coolant pumps can be avoided. 
     Moreover, a system is provided in which two coolant circuits can be deaired using only one expansion tank, while conditions are provided for isolating the second coolant circuit from the first coolant circuit when wanted simply by controlling the valve to the first state. In this manner, the first and second coolant circuits can be allowed to operate at different temperature levels when wanted simply by controlling the valve to the first state. 
     Furthermore, since the two coolant circuits can be deaired using only one expansion tank, a less costly and complex thermal management system is provided. Accordingly, a thermal management system is provided having conditions and/or characteristics suitable for being manufactured and assembled in a cost-efficient manner. Moreover, a thermal management system is provided having conditions for utilizing the available space in a vehicle in a more efficient manner. 
     In addition, a system is provided having conditions for connecting the second coolant circuit to the first coolant circuit so as to at least partially mix coolant of the first and second coolant circuits when wanted simply by controlling the valve to the second state. In this manner, heat energy can be transferred from one of the first and second coolant circuits to the other of the first and second coolant circuits. Thereby, a system is provided capable of transferring heat between the first and second coolant circuits and components and systems thermally connected to the respective first and second coolant circuits. As a result thereof, a system is provided capable of managing heat in an improved manner. 
     Accordingly, a vehicle thermal management system is provided overcoming, or at least alleviating, at least some of the above-mentioned problems and drawbacks. As a result, the above-mentioned object is achieved. 
     Optionally, the first connecting conduit comprises a first end connected to the coolant duct and a second end connected to the second coolant circuit, and wherein the first end is arranged above the second end when the system is mounted in an intended mounting position on a vehicle. Thereby, a system is provided having improved conditions for deairing the second coolant circuit via the first connecting conduit. Moreover, due to these features, filling of coolant into the system can be facilitated, for example during assembly, service, and repair of the system. 
     Optionally, the first connecting conduit is routed such that an intended flow direction through the first connecting conduit has a vector component parallel to a local gravity vector along the full length of the first connecting conduit when the system is mounted in an intended mounting position on a vehicle. Thereby, it is ensured that air bubbles can be transported along the full length of the first connecting conduit in an efficient manner due to gravity and the density difference between the air bubbles and the coolant. Moreover, due to these features, filling of coolant into the system is facilitated, for example during assembly, service, and repair of the system. 
     Optionally, the first connecting conduit comprises a second end connected to the second coolant circuit via a connection arranged above the coolant pump of the second coolant circuit when the system is mounted in an intended mounting position on a vehicle. Thereby, a system is provided having conditions for deairing the coolant pump of the second coolant circuit in an efficient manner. Thereby, damages of the coolant pump of the second coolant circuit can be avoided. In addition, it can be ensured that coolant is reaching the coolant pump of the second coolant circuit when the system is filled with coolant, for example during assembly, service, and repair of the system. 
     Optionally, the second coolant circuit comprises a conduit section between the connection and the coolant pump of the second coolant circuit, and wherein the conduit section is routed such that an intended flow direction through the conduit section has a vector component parallel to a local gravity vector along the full length of the conduit section when the system is mounted in an intended mounting position on a vehicle. Thereby, it is ensured that air bubbles can be transported from the coolant pump of the second coolant circuit in an efficient manner along the full length of the conduit section due to gravity and the density difference between the air bubbles and the coolant. In this manner, a system is provided having further improved conditions for deairing the coolant pump of the second coolant circuit. In addition, it can be ensured that coolant is reaching the coolant pump of the second coolant circuit when the system is filled with coolant, for example during assembly, service, and repair of the system. 
     Optionally, the first connecting conduit comprises a second end connected to the second coolant circuit via a connection arranged upstream of the coolant pump of the second coolant circuit relative to an intended flow direction through the second coolant circuit. Thereby, a system is provided having conditions for deairing an inlet of the coolant pump of the second coolant circuit simply by controlling the valve to the second state. In this manner, damages of the coolant pump of the second coolant circuit can be avoided. Moreover, it can be ensured that coolant is reaching the coolant pump of the second coolant circuit when the system is filled with coolant, for example during assembly, service, and repair of the system. 
     In addition, it can be ensured that the inlet of the coolant pump of the first coolant circuit and the inlet of the coolant pump of the second coolant circuit have the same static pressure, or at least substantially the same static pressure, at least when the valve is in the second state. 
     Optionally, the coolant duct comprises an expansion tank connection fluidly connecting the coolant duct to the expansion tank, and wherein the first connecting conduit is connected to the coolant duct at a location below the expansion tank connection when the system is mounted in an intended mounting position on a vehicle. Thereby, air bubbles transported from the second coolant circuit via the first connecting conduit can be transported through the coolant duct to the expansion tank connection in an efficient manner due to gravity and the density difference between the air bubbles and the coolant. 
     Optionally, the coolant duct comprises an inlet and an outlet each connected to the first coolant circuit, and wherein the coolant duct comprises an expansion tank connection fluidly connecting the coolant duct to the expansion tank, wherein the expansion tank connection is arranged above the inlet when the system is mounted in an intended mounting position on a vehicle. Thereby, conditions are provided for deairing the first and second coolant circuits in an efficient manner via the expansion tank connection. 
     Optionally, the expansion tank connection is arranged above the outlet when the system is mounted in an intended mounting position on a vehicle. Thereby, air can be evacuated in an efficient manner via the expansion tank connection while flow of air is avoided through the outlet of the coolant duct. 
     Optionally, the coolant duct is configured to conduct coolant flow along a flow direction having a vector component parallel to a local gravity vector along the full length of the coolant duct when the coolant duct is mounted in an intended mounting position on a vehicle. Thereby, it is ensured that air bubbles can be transported along the full length of the coolant duct in an efficient manner due to gravity and the density difference between the air bubbles and the coolant. Thereby, conditions are provided for deairing the first and second coolant circuits in a further efficient manner. 
     Optionally, the system comprises a second connecting conduit fluidly connecting the second coolant circuit to the coolant duct. Thereby, a system is provided having improved conditions for mixing coolant of the first and second coolant circuits when wanted simply by controlling the valve to the second state. Thereby, heat energy can be transferred from one of the first and second coolant circuits to the other of the first and second coolant circuits in a more efficient manner. Accordingly, a system is provided capable of managing heat in an improved manner as well as an improved ability to transfer heat between the first and second coolant circuits and components and systems thermally connected to the respective first and second coolant circuits. 
     As a further result thereof, conditions are provided for designing at least one of the first and second coolant circuits with a lower cooling or heating capacity than would be the case otherwise. 
     Moreover, due to the second connecting conduit, it can be ensured that the inlets of the pumps of the first and second coolant circuits can be supplied with coolant at the same static pressure, or at least substantially the same static pressure, regardless of whether the valve is in the first or second state. Thereby, cavitation in the pumps of the first and second coolant circuits can be avoided in a simple and efficient manner. 
     Furthermore, since the second coolant circuit is fluidly connected to the coolant duct of the first coolant circuit via the second connecting conduit and is fluidly connectable to the coolant duct of the first coolant circuit via the first connecting conduit, it can be ensured that the pumps of the first and second coolant circuits can be operated independently without causing any flow disturbances in the other coolant circuit regardless of whether the valve is in the first or second state. 
     Optionally, the second connecting conduit comprises a flow restrictor. Thereby, unintended and unwanted flow of coolant is avoided through the second connecting conduit when the valve is in the first state, such as a spontaneous mixing of coolant of the first and second coolant circuits. 
     Optionally, one of the first and second connecting conduits is configured to supply coolant from the coolant duct to the second coolant circuit and the other of the first and second connecting conduits is configured to return coolant from the second coolant circuit to the coolant duct when the valve is in the second state. Thereby, a system is provided having improved conditions for mixing coolant of the first and second coolant circuits when wanted simply by controlling the valve to the second state. In this manner, heat energy can be transferred from one of the first and second coolant circuits to the other of the first and second coolant circuits in an efficient manner. Thereby, a system is provided having an improved ability to transfer heat between the first and second coolant circuits and components and systems thermally connected to the respective first and second coolant circuits. 
     Moreover, due to these features, it is ensured that the pumps of the first and second coolant circuits can be operated independently without causing any flow disturbances in the other coolant circuit regardless of whether the valve is in the first or second state. 
     Optionally, the connecting conduit of the first and second connecting conduits which is configured to supply coolant to the second coolant circuit, comprises a connection at the coolant duct located upstream of a connection of the other connecting conduit at the coolant duct relative to an intended flow direction through the coolant duct. Thereby, a more complete mixing of coolant of the first and second coolant circuits is provided when the valve is in the second state while it is ensured that the pumps of the first and second coolant circuits can be operated independently without causing any flow disturbances in the other coolant circuit. Accordingly, a system is provided having improved conditions for mixing coolant of the first and second coolant circuits when wanted simply by controlling the valve to the second state. In this manner, heat energy can be transferred from one of the first and second coolant circuits to the other of the first and second coolant circuits in a more efficient manner. 
     Thereby, a system is provided having an improved ability to transfer heat between the first and second coolant circuits and components and systems thermally connected to the respective first and second coolant circuits. Moreover, conditions are provided for designing at least one of the first and second coolant circuits with a lower cooling capacity than would be the case otherwise. 
     Optionally, the second coolant circuit is configured to heat a vehicle occupant compartment. Thereby, the second coolant circuit, which is configured to heat a vehicle occupant compartment, can be deaired in an efficient manner simply by controlling the valve to the second state. 
     Optionally, the first coolant circuit is configured to cool components of an electric propulsion system. Thereby, a system is provided capable of utilizing the expansion tank of a coolant circuit being configured to cool components of an electric propulsion system for deairing a second coolant circuit. 
     According to a second aspect of the invention, the object is achieved by a vehicle comprising a vehicle thermal management system according to some embodiments of the present disclosure. 
     Since the vehicle comprises a thermal management system according to some embodiments, a vehicle is provided having conditions for deairing two coolant circuits via one expansion tank in an efficient manner. Since the two coolant circuits can be deaired using only one expansion tank, a less costly and complex vehicle can be provided. Moreover, conditions are provided for utilizing the available space in the vehicle in a more efficient manner. 
     Moreover, a vehicle is provided comprising a thermal management system capable of managing heat in an improved manner. 
     Accordingly, a vehicle is provided overcoming, or at least alleviating, at least some of the above-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 DRAWINGS 
       Various aspects of the invention, including its particular features and advantages, will be readily understood from the example embodiments discussed in the following detailed description and the accompanying drawings, in which: 
         FIG.  1    illustrates a vehicle thermal management system according to some embodiments of the present disclosure, 
         FIG.  2    illustrates a vehicle thermal management system according to some further embodiments of the present disclosure, and 
         FIG.  3    illustrates a vehicle according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     Aspects of the present invention will now be described more fully. Like numbers refer to like elements throughout. Well-known functions or constructions will not necessarily be described in detail for brevity and/or clarity. 
       FIG.  1    illustrates a vehicle thermal management system  1  according to some embodiments of the present disclosure. The vehicle thermal management system  1  is in some places herein referred to as “the thermal management system  1 ”, or simply “the system  1 ”. The system  1  comprises a first and a second coolant circuit  11 ,  12  each comprising a coolant pump  21 ,  22 . The vehicle thermal management system  1 , as referred to herein, may also be referred to as a coolant circuit arrangement  1 . Therefore, throughout this disclosure, the wording “vehicle thermal management system  1 ”, “thermal management system  1 ”, or “system  1 ”, may be replaced with the wording “coolant circuit arrangement  1 ”. Moreover, the coolant pump  21  of the first coolant circuit  11  may be referred to as “the first coolant pump  21 ” and the coolant pump  22  of the second coolant circuit  12  may be referred to as “the second coolant pump  22 ”. 
     The first and second coolant circuits  11 ,  12  are separate and independent coolant circuits  11 ,  12  in the sense that they can operate at different temperature levels, can operate at different flow rate levels, and can operate for different purposes, as is further explained herein. According to the illustrated embodiments, the first coolant circuit  11  is configured to cool components  41 ,  42 ,  43  of an electric propulsion system  40 . Therefore, according to the illustrated embodiments, the first coolant circuit  11  may be referred to as an electric propulsion cooling circuit. According to further embodiments, the first coolant circuit  11  may be configured to regulate the temperature of one or more other types of components, systems, and/or arrangements, such as an internal combustion engine, a retarder, a waste heat recovery circuit, an occupant compartment, or the like. 
     According to the illustrated embodiments, the first coolant circuit  11  comprises a radiator  24 . The radiator  24  is configured to radiate heat from coolant in the first coolant circuit  11 . The radiator  24  may be arranged at a front area of a vehicle comprising the first coolant circuit  11  to be subjected to an air flow generated during driving of the vehicle. Moreover, the radiator  24  may be provided with one or more cooling fans  26  arranged to selectively blow air through the radiator  24 . The first coolant circuit  11  is in heat exchanging contact with the components  41 ,  42 ,  43  of the electric propulsion system  40 . According to the illustrated embodiments, the components  41 ,  42 ,  43  of the electric propulsion system  40  comprise an electric machine  41 , a propulsion battery  43 , and power electronics  42 . The first coolant circuit  11  further comprises a thermostatic valve  16  and a bypass line  18 . The bypass line  18  bypasses the radiator  24 . The thermostatic valve  16  is configured to direct coolant to the radiator  24  or to the bypass line  18 . The thermostatic valve  16  may be configured to direct coolant to the radiator  24  or to the bypass line  18  based on the temperature of coolant in the first coolant circuit  11  and/or based on a heating or cooling need of the components  41 ,  42 ,  43  of the electric propulsion system  40 . The thermostatic valve  16  may comprise a heat sensitive body. As an alternative, or in addition, the thermostatic valve  16  may be electronically controlled. 
     The first coolant circuit  11  further comprises a coolant duct  3  configured to conduct coolant flow through a portion  5  of the first coolant circuit  11 . According to the illustrated embodiments, the coolant duct  3  is arranged downstream of the radiator  24  and downstream of the bypass line  18  relative to an intended flow direction fd 3  of coolant through the first coolant circuit  11 . In more detail, the coolant duct  3  comprises an inlet  3 ′ connected to the radiator  24  and the bypass line  18  and an outlet  3 ″ connected to the coolant pump  21  of the first coolant circuit  11 . The first coolant circuit  11  further comprises an expansion tank  7  connected to the coolant duct  3  via an expansion tank connection  19  of the coolant duct  3 . The expansion tank connection  19  of the coolant duct  3  thus fluidly connects the coolant duct  3  to the expansion tank  7 . 
     As indicated in  FIG.  1   , the coolant duct  3  is configured to conduct coolant flow along a flow direction fd 3 . The flow direction fd 3  has a vector component c 3  parallel to a local gravity vector gv along the full length of the coolant duct  3  when the coolant duct  3  is mounted in an intended mounting position on a vehicle and the vehicle is positioned in an intended use position onto a flat horizontal surface. In other words, the angle between the flow direction fd 3  and the local gravity vector gv may be within the range of 0 degrees to 90 degrees along the full length of the coolant duct  3  when the coolant duct  3  is mounted in an intended mounting position on a vehicle and the vehicle is positioned in an intended use position onto a flat horizontal surface. In this manner, air bubbles entering the coolant duct  3 , for example via the inlet  3 ′ of the coolant duct  3 , can be transported to the expansion tank connection  19  in an efficient manner due to gravity and the density difference between the air bubbles and the coolant. That is, since air has a lower density than the coolant, any air bubble will rise due to gravity acting on the coolant surrounding the air bubbles. The intended mounting position, as referred to herein, is a position and orientation of components  3 ,  9 ,  13 ,  21 ,  22 ,  28 ,  14  of the system  1  obtained when the components are mounted to a vehicle, as is further explained herein. Moreover, as is further explained herein, in  FIG.  1   , some components  3 ,  9 ,  13 ,  21 ,  22 ,  28 ,  14  of the system  1 , including the coolant duct  3 , are illustrated in a respective position and orientation corresponding to the intended mounting position thereof. 
     As seen in  FIG.  1   , according to the illustrated embodiments, the expansion tank connection  19  is arranged at a top portion of the coolant duct  3  relative to the local gravity vector gv. That is, the expansion tank connection  19  is arranged above the inlet  3 ′ of the coolant duct  3  when the coolant duct  3  is mounted in the intended mounting position on a vehicle. Moreover, the expansion tank connection  19  is arranged above the outlet  3 ″ of the coolant duct  3  when the coolant duct  3  is mounted in the intended mounting position on a vehicle. Thereby, air can be evacuated in an efficient manner via the expansion tank connection  19  while flow of air is avoided through the outlet  3 ″ of the coolant duct  3 . 
     The coolant duct  3  may be formed by a pipe comprising a number of connections  3 ′,  3 ″,  39 ,  19 ,  49  as is further explained herein. The expansion tank connection  19  of the coolant duct  3  is directly connected to the expansion tank  7  via an expansion tank conduit  28 . An inner volume of the coolant duct  3  is thus directly connected to the expansion tank  7  via the expansion tank conduit  28 . The expansion tank  7  is arranged at a position higher than the expansion tank connection  19  relative to the local gravity vector gv when the expansion tank is arranged in its intended mounting position on a vehicle. Moreover, the expansion tank conduit  28  is routed such that a flow direction through the expansion tank conduit  28  has a vector component being parallel to the local gravity vector gv along the full length of the expansion tank conduit  28  when the system  1  is mounted in the intended mounting position on a vehicle and the vehicle is positioned in an intended use position onto a flat horizontal surface. In this manner, air bubbles entering the expansion tank conduit  28  can be transported to the expansion tank  7  in an efficient manner due to gravity and the density difference between the air bubbles and the coolant. 
     The coolant duct  3  may be provided with a greater cross sectional area in a plane perpendicular to the intended flow direction fd 3  through the coolant duct  3  than the cross sectional area of other conduit sections of the first coolant circuit  11 , such as a conduit section  25  between the outlet  3 ″ of the coolant duct  3  and the coolant pump  21  of the first coolant circuit  11 . The coolant duct  3  may be provided with a cross sectional area being at least three times greater than the cross sectional area conduit section  25  between the outlet  3 ″ of the coolant duct  3  and the coolant pump  21  of the first coolant circuit  11 . In this manner, a low flow resistance and a low pressure drop is provided through the coolant duct  3 . Moreover, a low flow velocity of coolant is obtained through the coolant duct  3 . Therefore, the coolant duct  3 , as referred to herein, may also be referred to as a “coolant chamber”, a “low flow velocity chamber”, a “low flow velocity coolant chamber”, or the like. 
     The expansion tank conduit  28 , as referred to herein, may also be referred to as a static line. This because during normal operation of the system  1 , there is only a low or no flow of fluid through the expansion tank conduit  28 . Therefore, throughout this disclosure, the wording “expansion tank conduit” may be replaced with the wording “static line.” 
     Furthermore, according to the illustrated embodiments, the coolant duct  3  is arranged such that the intended flow direction fd 3  through the coolant duct  3  is substantially parallel to the local gravity vector gv along the full length of the coolant duct  3 . This means that, according to the illustrated embodiments, the coolant duct  3  is positioned in an upright position relative to the local gravity vector gv, in which the coolant duct  3  is substantially parallel to the local gravity vector gv, when being arranged in the intended mounting position on a vehicle. However, as indicated above, the coolant duct  3  may be arranged such that the angle between the intended flow direction fd 3  and the local gravity vector gv is within the range of 0 degrees to 90 degrees. 
     According to the illustrated embodiments, the second coolant circuit  12  is configured to heat a vehicle occupant compartment  35 . Therefore, according to the illustrated embodiments, the second coolant circuit  12  may be referred to as an “occupant compartment heating circuit”. According to further embodiments, the second coolant circuit  12  may be configured to regulate the temperature of one or more other types of components, systems, and/or arrangements, such as an internal combustion engine, a retarder, a waste heat recovery circuit, an electric propulsion system, a fuel cell, or the like. 
     According to the illustrated embodiments, the second coolant circuit  12  comprises a heat exchanger  30 . The system  1  further comprises a fan  32  configured to generate an airflow through the heat exchanger  30  into the occupant compartment  35 . According to further embodiments, the second coolant circuit  12  may comprise one or more radiators arranged in the occupant compartment  35  configured to heat the occupant compartment  35  by convection. 
     The second coolant circuit  12  is in thermal contact with a heat generating component  34 . The heat generating component  34  may for example comprise a combustion engine, an electric machine, a propulsion battery, a liquid cooled condenser, power electronics, or the like. As an alternative, or in addition, the heat generating component  34  may be a condenser of a heat pump circuit. The heat generating component  34  is configured to heat coolant in the second coolant circuit  12  during operation of a vehicle comprising the system  1 . 
     The second coolant circuit  12  further comprises an electrical heater  36 . The electrical heater  36  is configured to heat coolant in the second coolant circuit  12  when heat from the heat generating component  34  is insufficient for heating the occupant compartment  35 . As seen in  FIG.  1   , the heat generating component  34  and the electrical heater  36  are arranged between the coolant pump  22  of the second coolant circuit  12  and the heat exchanger  30  of the second coolant circuit  12 . 
     According to embodiments herein, the vehicle thermal management system  1  comprises a first connecting conduit  9 . The first connecting conduit  9  connects the second coolant circuit  12  to the coolant duct  3 . Moreover, the system  1  comprises a valve  13 . The valve  13  is controllable between a first state and a second state. In the first state, the valve  13  hinders, i.e. blocks, flow of fluid through the first connecting conduit  9 . In the second state, the valve  13  allows flow of fluid through the first connecting conduit  9  to deair the second coolant circuit  12  via the expansion tank  7 . In this manner, the second coolant circuit  12  can be deaired via the coolant duct  3  of the first coolant circuit  11  simply by controlling the valve  13  to the second state, as is further explained herein. 
     As indicated in  FIG.  1   , the first connecting conduit  9  comprises a first end  9 ′ connected to the coolant duct  3  and a second end  9 ″ connected to the second coolant circuit  12 . According to the illustrated embodiments, the first end  9 ′ is arranged above the second end  9 ″ when the system  1  is mounted in the intended mounting position on a vehicle. Moreover, according to the illustrated embodiments, the first connecting conduit  9  is routed such that an intended flow direction fd 9  through the first connecting conduit  9  has a vector component c 9  parallel to a local gravity vector gv along the full length of the first connecting conduit  9  when the system  1  is mounted in the intended mounting position on a vehicle and the vehicle is positioned in an intended use position onto a flat horizontal surface. In other words, the angle between the flow direction fd 9  and the local gravity vector gv may be within the range of 0 degrees to 90 degrees along the full length of the first connecting conduit  9  when the first connecting conduit  9  is mounted in an intended mounting position on a vehicle and the vehicle is positioned in an intended use position onto a flat horizontal surface. In this manner, air bubbles entering the first connecting conduit  9  can be transported along the full length of the first connecting conduit  9  in an efficient manner due to gravity and the density difference between the air bubbles and the coolant. Moreover, due to these features, filling of coolant into the system  1  is facilitated, for example during assembly, service, and repair of the system  1 . 
     As seen in  FIG.  1   , according to the illustrated embodiments, the second end  9 ″ of the first connecting conduit  9  is connected to the second coolant circuit  12  via a connection  12 ′ arranged above the coolant pump  22  of the second coolant circuit  12  when the system  1  is mounted in the intended mounting position on a vehicle. Moreover, the second coolant circuit  12  comprises a conduit section  14  between the connection  12 ′ and the coolant pump  22  of the second coolant circuit  12 . The connection  12 ′ between the second end  9 ″ of the first connecting conduit  9  and the second coolant circuit  12  is arranged upstream of the coolant pump  22  of the second coolant circuit  12  relative to an intended flow direction fd 14  through the second coolant circuit  12 . The conduit section  14  is routed such that an intended flow direction fd 14  through the conduit section  14  has a vector component c 14  parallel to a local gravity vector gv along the full length of the conduit section  14  when the system  1  is mounted in the intended mounting position on a vehicle and the vehicle is positioned in an intended use position onto a flat horizontal surface. In other words, the angle between the flow direction fd 14  and the local gravity vector gv may be within the range of 0 degrees to 90 degrees along the full length of the conduit section  14  when the system  1  is mounted in an intended mounting position on a vehicle and the vehicle is positioned in an intended use position onto a flat horizontal surface. In this manner, the coolant pump  22  of the second coolant circuit  12  can be deaired in an efficient manner simply by controlling the valve  13  to the second state. Furthermore, it can be ensured that coolant is reaching the coolant pump  22  of the second coolant circuit  12  when filling the system  1  with coolant. Accordingly, due to these features, filling of coolant into the system  1  is facilitated, for example during assembly, service, and repair of the system  1 . 
     As indicated above, the system  1  comprises a conduit section  25  between the outlet  3 ″ of the coolant duct  3  and the coolant pump  21  of the first coolant circuit  11 . As seen in  FIG.  1   , the outlet  3 ″ of the coolant duct  3  is arranged above the coolant pump  21  of the first coolant circuit  11  when the system  1  is mounted in the intended mounting position on a vehicle. Moreover, the outlet  3 ″ of the coolant duct  3  is arranged upstream of the coolant pump  21  of the first coolant circuit  11  relative to an intended flow direction through the first coolant circuit  11 . The conduit section  25  between the outlet  3 ″ of the coolant duct  3  and the coolant pump  21  of the first coolant circuit  11  is routed such that an intended flow direction through the conduit section  25  has a vector component parallel to a local gravity vector gv along the full length of the conduit section  25  when the system  1  is mounted in the intended mounting position on a vehicle and the vehicle is positioned in an intended use position onto a flat horizontal surface. In other words, the angle between the intended flow direction through the conduit section  25  and the local gravity vector gv may be within the range of 0 degrees to 90 degrees along the full length of the conduit section  25  when the system  1  is mounted in an intended mounting position on a vehicle and the vehicle is positioned in an intended use position onto a flat horizontal surface In this manner, the coolant pump  21  of the first coolant circuit  11  is deaired in an efficient manner via the coolant duct  3 . Furthermore, it can be ensured that coolant is reaching the coolant pump  21  of the first coolant circuit  11  when filling the system  1  with coolant. Accordingly, due to these features, filling of coolant into the system  1  is facilitated, for example during assembly, service, and repair of the system  1 . 
     Moreover, as seen in  FIG.  1   , according to the illustrated embodiments, the first end  9 ′ of the first connecting conduit  9  is connected to the coolant duct  3  at a location below the expansion tank connection  19  relative to the local gravity vector gv when the system  1  is mounted in the intended mounting position on a vehicle. In this manner, air bubbles entering the coolant duct  3  from the first connecting conduit  9  can be transported in an efficient manner to the expansion tank connection  19  due to gravity and the density difference between the air bubbles and the coolant. 
     According to the illustrated embodiments, the connection  12 ′ between the first connecting conduit  9  and the second coolant circuit  12  is an outlet  12 ′ of the valve  13 . That is, according to the embodiments illustrated in  FIG.  1   , the valve  13  is a three-way valve  13  comprising a one inlet  13 ′ and two outlets  12 ′,  13 ′. According to further embodiments, the valve  13 , as referred to herein, may be a two-way valve positioned in the first connecting conduit  9  or at the first or second end  9 ′,  9 ″ of the first connecting conduit  9 . Moreover, according to some further embodiments of the present disclosure, the valve  13  may be a three-way valve comprising two inlets and one outlet, as is further explained herein. 
     According to the embodiments illustrated in  FIG.  1   , the valve  13  comprises an inlet  13 ′ connected to the heat exchanger  30  of the second coolant circuit  12 . Moreover, the valve  13  comprises a first outlet  13 ″ connected to the conduit section  14  between the valve  13  and the coolant pump  22  of the second coolant circuit  12 . The valve  13  further comprises a second outlet  12 ′ connected to the second end  9 ″ of the first connecting conduit  9 . The second outlet  12 ′ of the valve  13  is in some places herein referred to as the connection  12 ′ between the first connecting conduit  9  and the second coolant circuit  12 . 
     In the first state, the valve  13  opens a fluid connection between the inlet  13 ′ and the first outlet  13 ″ and closes a fluid connection between the inlet  13 ′ and the second outlet  12 ′. Thereby, the valve  13  hinders flow of fluid, i.e. coolant, through the first connecting conduit  9  when the valve  13  is in the first state. In this manner, the coolant pump  22  of the second coolant circuit  12  can pump coolant through the heat generating component  34 , the electrical heater  36  and the heat exchanger  35  into the valve  13  via the inlet  13 ′ and out from the valve  13  via the first outlet  13 ″ to the coolant pump  22  when the valve  13  is in the first state. The second coolant circuit  12  can be said to be isolated from the first coolant circuit  11  when the valve  13  is in the first state. This because the coolant pump  22  of the second coolant circuit  12  can pump coolant through the second coolant circuit  12  without any mixing of coolant between the first and second coolant circuits  11 ,  12 . 
     According to the illustrated embodiments, the second state of the valve  13 , as referred to herein, is a state in which the valve  13  opens a fluid connection between the inlet  13 ′ and the second outlet  12 ′ of the valve  13  and closes a fluid connection between the inlet  13 ′ and the first outlet  13 ″ of the valve  13 . According to further embodiments, second state of the valve  13 , as referred to herein, may be a state in which the valve  13  at least partially opens a fluid connection between the inlet  13 ′ and the first and second outlets  12 ′,  13 ″ of the valve  13 . 
     As seen in  FIG.  1   , according to the illustrated embodiments, the system  1  comprises a second connecting conduit  29  fluidly connecting the second coolant circuit  12  to the coolant duct  3 . According to the embodiments illustrated in  FIG.  1   , the second connecting conduit  29  is configured to return coolant from the coolant duct  3  to the second coolant circuit  12  when the valve  13  is in the second state. Accordingly, as understood from the above, the first connecting conduit  9  is configured to supply coolant to the coolant duct  3  and the second connecting conduit  29  is configured to return coolant from the coolant duct  3  when the valve  13  is in the second state. Moreover, according to the illustrated embodiments, the coolant duct  3  is provided with a greater cross sectional area in a plane perpendicular to the intended flow direction fd 3  through the coolant duct  3  than the cross sectional area of other conduit sections of the first coolant circuit  11 . Due to these features, it is ensured that the pumps  21 ,  22  of the first and second coolant circuits  11 ,  12  can be operated independently without causing any flow disturbances in the other coolant circuit  11 ,  12  also when the valve  13  is in the second state. 
     According to embodiments illustrated in  FIG.  1   , the second connecting conduit  29  comprises a first end  29 ′ connected to the coolant duct  3  at a location upstream of the connection  39  of the first connecting conduit  9  at the coolant duct  3  relative to an intended flow direction fd 3  through the coolant duct  3 . The first end  29 ′ of the second connecting conduit  29  is connected to the coolant duct  3  via a connection  49 . Moreover, the second connecting conduit  29  comprises a second end  29 ″ connected to the conduit section  14  between the valve  13  and the coolant pump  22  of the second coolant circuit  12 . Due to these features, coolant being pumped into the coolant duct  3  via the first connecting conduit  9  flows through the first coolant circuit  11  before flowing back to the second coolant circuit  12  via the second connecting conduit  29 , when the valve  13  is in the second state. In this manner, a substantially complete mixing of coolant of the first and second coolant circuits  11 ,  12  is provided when the valve  13  is in the second state, which can be utilized to transfer heat or cold between the first and second coolant circuits  11 ,  12  in an efficient manner by controlling the valve  13  to the second state. 
     According to further embodiments, the second connecting conduit  29  may comprise a first end  29 ′ connected to the coolant duct  3  at a location downstream of the connection  39  of the first connecting conduit  9  at the coolant duct  3  relative to an intended flow direction fd 3  through the coolant duct  3 . According to such embodiments, an at least partial mixing of coolant of the first and second coolant circuits  11 ,  12  can be provided in the coolant duct  3  when the valve  13  is in the second state, which can be utilized to transfer heat or cold between the first and second coolant circuits  11 ,  12  by controlling the valve  13  to the second state. 
     Accordingly, due to the features of the system  1 , the second coolant circuit  12  can be deaired in an efficient manner via the first connecting conduit  9  while conditions are provided for transferring heat between the first and second coolant circuits  11 ,  12  and components and systems  24 ,  30 ,  41 ,  42 ,  43  thermally connected to the respective first and second coolant circuits  11 ,  12 . As a result thereof, a system  1  is provided capable of managing heat in an improved manner. In other words, a system  1  is provided in which the first and second coolant circuits  11 ,  12  are allowed to operate independently regarding coolant temperature when the valve  13  is in the first state, while conditions are provided for deairing the second coolant circuit  12  and transferring heat between the first and second coolant circuits  11 ,  12  in an efficient manner when the valve  13  is in the second state. 
     The system  1  may comprise a control arrangement configured to control the opening state of the valve  13 , i.e. control the valve  13  between the first and second states. The control arrangement may be further configured to control operation of one or both of the coolant pumps  21 ,  22  of the first and second coolant circuits  11 ,  12 . Such a control arrangement is not illustrated in  FIG.  1    for the reason of brevity and clarity. The control arrangement may be configured to control the valve  13  to the second state when it is desired to deair the second coolant circuit  12 , such as when air is estimated to be present in the second coolant circuit  12 . As an example, air can be estimated to be present in the second coolant circuit  12  after assembly, service, or repair of the system  1 . As an alternative, or in addition, the control arrangement may be configured to control the valve  13  to the second state when it is desired to transfer heat between the first and second coolant circuits  11 ,  12 . According to the illustrated embodiments, it may be desired to transfer heat from the first coolant circuit  11  to the second coolant circuit  12  when there is a high heating need of the occupant compartment  35  and the coolant temperature in the first coolant circuit  11  is high and the coolant temperature in the second coolant circuit  12  is low. Thus, in such situations, the control arrangement may control the valve  13  to the second state, and as a result thereof, the heat of the coolant of the first coolant circuit  11  can be utilized for heating the occupant compartment  35 . 
     According to the illustrated embodiments, the second connecting conduit  29  comprises a flow restrictor  31 . The flow restrictor  31  prevents mixing of coolant between the first and second coolant circuits  11 ,  12  when the valve  13  is in the first state. According to the illustrated embodiments, the flow restrictor  31  comprises an anti-mixing loop. The anti-mixing loop comprises a flow path routed such that mixing caused by temperature differences between coolant of the first and second coolant circuits  11 ,  12  is avoided. As an alternative, or in addition, the flow restrictor  31  may comprise another type of component configured to prevent mixing of coolant between the first and second coolant circuits  11 ,  12  when the valve  13  is in the first state, such as a one-way valve, a non-return valve, a check valve, or the like. 
     In  FIG.  1   , a horizontal plane hp and a local gravity vector gv are illustrated. The local gravity vector gv is representative of a local gravity vector gv at the location of the system  1 . The horizontal plane hp is perpendicular to the local gravity vector gv, i.e. the normal to the horizontal plane hp is parallel to the local gravity vector gv. The components of the system  1  are configured to be mounted in an intended mounting position on a vehicle. In  FIG.  1   , the coolant duct  3 , the first connecting conduit  9 , the valve  13 , the coolant pump  21  of the first coolant circuit  11 , the coolant pump  22  of the second coolant circuit  12 , the expansion tank conduit  28 , the conduit section  25  between the outlet  3 ″ of the coolant duct  3  and the coolant pump  21  of the first coolant circuit  11 , and the conduit section  14  between the valve  13  and the coolant pump  22  of the second coolant circuit  12  are illustrated in a respective position and orientation corresponding to an intended mounting position thereof. 
     Since the vector components c 3 , c 9 , c 14  referred to herein, are parallel to a local gravity vector gv, the vector components c 3 , c 9 , c 14  may also be referred to as vertical vector components. The feature that a vector component c 3 , c 9 , c 14  is parallel to a local gravity vector gv along the full length of a fluid conduction element  3 ,  9 ,  25 ,  28  means that the vector component c 3 , c 9 , c 14  does not change its vertical direction from a first vertical direction to a second vertical direction, wherein the second vertical direction is opposite to the first vertical direction, along the full length of a fluid conducting element  3 ,  9 ,  25 ,  28 . 
       FIG.  2    illustrates a vehicle thermal management system  1  according to some further embodiments of the present disclosure. The thermal management system  1  illustrated in  FIG.  2    comprises the same features, functions, and advantages as the thermal management system  1  explained with reference to  FIG.  1   , with some differences explained below. 
     According to the embodiments illustrated in  FIG.  2   , the first connecting conduit  9  is configured to return coolant from the coolant duct  3  to the second coolant circuit  12  and the second connecting conduit  29  is configured to supply coolant from the second coolant circuit  12  to the coolant duct  3  when the valve  13  is in the second state. Moreover, according to the embodiments illustrated in  FIG.  2   , the connection  12 ′ between the first connecting conduit  9  and the second coolant circuit  12  is an inlet  12 ′ of the valve  13 . That is, according to the embodiments illustrated in  FIG.  1   , the valve  13  is a three-way valve  13  comprising two inlets  13 ′,  12 ′ and one outlet  13 ″. According to further embodiments, the valve  13  may be a two-way valve positioned in the first connecting conduit  9  or at the first or second end  9 ′,  9 ″ of the first connecting conduit  9 . 
     According to the embodiments illustrated in  FIG.  2   , the valve  13  comprises a first inlet  13 ′ connected to the heat exchanger  30  of the second coolant circuit  12 . Moreover, the valve  13  comprises an outlet  13 ″ connected to the conduit section  14  between the valve  13  and the coolant pump  22  of the second coolant circuit  12 . The valve  13  further comprises a second inlet  12 ′ connected to the second end  9 ″ of the first connecting conduit  9 . 
     Also in these embodiments, the valve  13  is controllable between a first state and a second state. In the first state, the valve  13  opens a fluid connection between the first inlet  13 ′ and the outlet  13 ″ and closes a fluid connection between the second inlet  12 ′ and the outlet  13 ″. Thereby, the valve  13  hinders flow of fluid through the first connecting conduit  9  when the valve  13  is in the first state. In this manner, the coolant pump  22  of the second coolant circuit  12  can pump coolant through the heat generating component  34 , the electrical heater  36  and the heat exchanger  35  into the valve  13  via the first inlet  13 ′ and out from the valve  13  via the outlet  13 ″ to the coolant pump  22  when the valve  13  is in the first state. The second coolant circuit  12  can be said to be isolated from the first coolant circuit  11  when the valve  13  is in the first state. This because the coolant pump  22  of the second coolant circuit  12  can pump coolant through the second coolant circuit  12  without any mixing of coolant between the first and second coolant circuits  11 ,  12 . 
     According to the embodiments illustrated in  FIG.  2   , the second state of the valve  13  is a state in which the valve  13  opens a fluid connection between the second inlet  12 ′ and the outlet  13 ″ of the valve  13  and closes a fluid connection between the first inlet  13 ′ and the outlet  13 ″ of the valve  13 . According to further embodiments, second state of the valve  13 , as referred to herein, may be a state in which the valve  13  at least partially opens a fluid connection between the first and second inlets  12 ′,  13 ′ and the outlet  13 ″ of the valve  13 . 
     As seen in  FIG.  2   , the second connecting conduit  29  comprises a first end  29 ′ connected to the coolant duct  3  and a second end  29 ″ connected to the second coolant circuit  12 . The second end  29 ″ of the second connecting conduit  29  is connected to the second coolant circuit  12  at a location between the heat exchanger  30  and the valve  13 . In this manner, the first connecting conduit  9  will return coolant from the coolant duct  3  to the second coolant circuit  12  and the second connecting conduit  29  is configured to supply coolant from the second coolant circuit  12  to the coolant duct  3  when the valve  13  is in the second state. Thereby, it is ensured that the pumps  21 ,  22  of the first and second coolant circuits  11 ,  12  can be operated independently without causing any flow disturbances in the other coolant circuit  11 ,  12  also when the valve  13  is in the second state. 
     According to the embodiments illustrated in  FIG.  2   , the first end  29 ′ of the second connecting conduit  29  is connected to the coolant duct  3  at a location downstream of the connection  39  of the first connecting conduit  9  at the coolant duct  3  relative to an intended flow direction fd 3  through the coolant duct  3 . Due to these features, coolant being pumped into the coolant duct  3  via the second connecting conduit  29  flows through the first coolant circuit  11  before flowing back to the second coolant circuit  12  via the first connecting conduit  9 , when the valve  13  is in the second state. In this manner, a substantially complete mixing of coolant of the first and second coolant circuits  11 ,  12  is provided when the valve  13  is in the second state, which can be utilized to transfer heat or cold between the first and second coolant circuits  11 ,  12  by controlling the valve  13  to the second state. 
     According to further embodiments, the second connecting conduit  29  may comprise a first end  29 ′ connected to the coolant duct  3  at a location upstream of the connection  39  of the first connecting conduit  9  at the coolant duct  3  relative to an intended flow direction fd 3  through the coolant duct  3 . According to such embodiments, an at least partial mixing of coolant of the first and second coolant circuits  11 ,  12  can be provided in the coolant duct  3  when the valve  13  is in the second state, which can be utilized to transfer heat or cold between the first and second coolant circuits  11 ,  12  by controlling the valve  13  to the second state. 
     Also in these embodiments, the first connecting conduit  9  comprises a first end  9 ′ connected to the coolant duct  3  and a second end  9 ″ connected to the second coolant circuit  12 . The first end  9 ′ is arranged above the second end  9 ″ when the system  1  is mounted in the intended mounting position on a vehicle. Moreover, the first connecting conduit  9  is routed such that an intended flow direction fd 9  through the first connecting conduit  9  has a vector component c 9  parallel to a local gravity vector gv along the full length of the first connecting conduit  9  when the system  1  is mounted in the intended mounting position on a vehicle and the vehicle is positioned in an intended use position onto a flat horizontal surface. In other words, the angle between the flow direction fd 9  and the local gravity vector gv may be within the range of 0 degrees to 90 degrees along the full length of the first connecting conduit  9  when the first connecting conduit  9  is mounted in an intended mounting position on a vehicle and the vehicle is positioned in an intended use position onto a flat horizontal surface. In this manner, air bubbles entering the first connecting conduit  9  can be transported along the full length of the first connecting conduit  9  in an efficient manner due to gravity and the density difference between the air bubbles and the coolant. Moreover, due to these features, filling of coolant into the system  1  is facilitated, for example during assembly, service, and repair of the system  1 . 
     As a result of these features, the second coolant circuit  12  can be deaired in an efficient manner via the first connecting conduit  9  while conditions are provided for transferring heat between the first and second coolant circuits  11 ,  12  and components and systems  24 ,  30 ,  41 ,  42 ,  43  thermally connected to the respective first and second coolant circuits  11 ,  12 . As a result thereof, a system  1  is provided capable of managing heat in an improved manner. In other words, a system  1  is provided in which the first and second coolant circuits  11 ,  12  are allowed to operate independently regarding coolant temperature when the valve  13  is in the first state, while conditions are provided for deairing the second coolant circuit  12  and transferring heat between the first and second coolant circuits  11 ,  12  in an efficient manner when the valve  13  is in the second state. 
     Moreover, also in these embodiments, the second connecting conduit  29  comprises a flow restrictor  31 . The flow restrictor  31  prevents mixing of coolant between the first and second coolant circuits  11 ,  12  when the valve  13  is in the first state. According to the illustrated embodiments, the flow restrictor  31  comprises an anti-mixing loop. The anti-mixing loop comprises a flow path routed such that mixing caused by temperature differences between coolant of the first and second coolant circuits  11 ,  12  is avoided. As an alternative, or in addition, the flow restrictor  31  may comprise another type of component configured to prevent mixing of coolant between the first and second coolant circuits  11 ,  12  when the valve  13  is in the first state, such as a one-way valve, a non-return valve, a check valve, or the like. 
     In  FIG.  2   , a horizontal plane hp and a local gravity vector gv are illustrated. The local gravity vector gv is representative of a local gravity vector gv at the location of the system  1 . The horizontal plane hp is perpendicular to the local gravity vector gv, i.e. the normal to the horizontal plane hp is parallel to the local gravity vector gv. The components of the system  1  are configured to be mounted in an intended mounting position on a vehicle. In  FIG.  2   , the coolant duct  3 , the first connecting conduit  9 , the valve  13 , the coolant pump  21  of the first coolant circuit  11 , the coolant pump  22  of the second coolant circuit  12 , the expansion tank conduit  28 , the conduit section  25  between the outlet  3 ″ of the coolant duct  3  and the coolant pump  21  of the first coolant circuit  11 , and the conduit section  14  between the valve  13  and the coolant pump  22  of the second coolant circuit  12  are illustrated in a respective position and orientation corresponding to an intended mounting position thereof. 
       FIG.  3    illustrates a vehicle  2  according to some embodiments. The vehicle  2  may comprise a vehicle thermal management system  1  according to the embodiments illustrated in  FIG.  1   , or a vehicle thermal management system  1  according to the embodiments illustrated in  FIG.  2   . In  FIG.  3   , the radiator  24  of the first coolant circuit of the system  1  is indicated. 
     The vehicle  2  comprises an electric propulsion system  40 . The electric propulsion system  40  is configured to provide motive power to the vehicle  2  via wheels  4  of the vehicle  2 . The first coolant circuit of the system  1  may be configured to regulate the temperature of one or more components of the electric propulsion system  40  of the vehicle  2 . In  FIG.  3   , an occupant compartment  35  is indicated. The second coolant circuit of the system  1  may be configured to heat the occupant compartment  35 . 
     According to the illustrated embodiments, the vehicle  2  is a truck. However, according to further embodiments, the vehicle  2 , as referred to herein, may be another type of manned or unmanned 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. 
     Moreover, according to further embodiments, the vehicle  2  may comprise an internal combustion engine, for example a compression ignition engine, such as a diesel engine, or an Otto engine with a spark-ignition device, wherein the Otto engine may be configured to run on gas, petrol, alcohol, similar volatile fuels, or combinations thereof. According to such embodiments, the first coolant circuit of the system  1  may be configured to regulate the temperature of the internal combustion engine and/or one or more components of the internal combustion engine. 
     The control arrangement, as referred to herein, may comprise a calculation unit which may take the form of substantially any suitable type of processor circuit or microcomputer, e.g. a circuit for digital signal processing (digital signal processor, DSP), a Central Processing Unit (CPU), a processing unit, a processing circuit, a processor, an Application Specific Integrated Circuit (ASIC), a microprocessor, or other processing logic that may interpret and execute instructions. The herein utilised expression “calculation unit” may represent a processing circuitry comprising a plurality of processing circuits, such as, e.g., any, some or all of the ones mentioned above. 
     The control arrangement may further comprise a memory unit, wherein the calculation unit may be connected to the memory unit, which may provide the calculation unit with, for example, stored program code and/or stored data which the calculation unit may need to enable it to do calculations. The calculation unit may also be adapted to store partial or final results of calculations in the memory unit. The memory unit may comprise a physical device utilised to store data or programs, i.e., sequences of instructions, on a temporary or permanent basis. According to some embodiments, the memory unit may comprise integrated circuits comprising silicon-based transistors. The memory unit may comprise e.g. a memory card, a flash memory, a USB memory, a hard disc, or another similar volatile or non-volatile storage unit for storing data such as e.g. ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), EEPROM (Electrically Erasable PROM), etc. in different embodiments. 
     The control arrangement may be connected to components of the system  1  for receiving and/or sending input and output signals. These input and output signals may comprise waveforms, pulses, or other attributes which the input signal receiving devices can detect as information and which can be converted to signals processable by the control arrangement. These signals may then be supplied to the calculation unit. One or more output signal sending devices may be arranged to convert calculation results from the calculation unit to output signals for conveying to other parts of the vehicle&#39;s control system and/or the component or components for which the signals are intended. Each of the connections to the respective components of the system  1  for receiving and sending input and output signals may take the form of one or more from among a cable, a data bus, e.g. a CAN (controller area network) bus, a MOST (media orientated systems transport) bus or some other bus configuration, or a wireless connection. 
     The control arrangement, as referred to herein, may be implemented wholly or partly in two or more control arrangements or two or more control units. Control systems in modern vehicles generally comprise a communication bus system consisting of one or more communication buses for connecting a number of electronic control units (ECUs), or controllers, to various components on board the vehicle. Such a control system may comprise a large number of control units and taking care of a specific function may be shared between two or more of them. Vehicles of the type here concerned are therefore often provided with significantly more control arrangements as one skilled in the art will surely appreciate. 
     It is to be understood that the foregoing is illustrative of various example embodiments and that the invention is defined only by the appended claims. A person skilled in the art will realize that the example embodiments may be modified, and that different features of the example embodiments may be combined to create embodiments other than those described herein, 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 or more stated features, elements, steps, components, or functions but does not preclude the presence or addition of one or more other features, elements, steps, components, functions, or groups thereof.