Coolant system and vehicle

Abstract

A coolant system (1) for a vehicle (2) is disclosed. The coolant system (1) comprises a first coolant subsystem (cs1), a second coolant subsystem (cs2), a first static line (S1) connected to the first coolant subsystem (cs1), a second static line (S2) connected to the second coolant subsystem (cs2), an expansion vessel (19), a deaeration line (3) connected to the expansion vessel (19), and a deaeration junction (7) connecting the first and second static lines (S1, S2) to the deaeration line (3). The extension direction (ed1, ed2) of segments (S1', S2') of the first and second static lines (S1, S2) is inclined upwards toward the deaeration junction (7) with an inclination angle (a1, a2) within the range of 7 - 70 degrees, or within the range of 20 - 50 degrees, as measured relative to a plane (hp) perpendicular to a vertical direction (vd') of the coolant system (1). The present disclosure further relates to a vehicle (2) comprising a coolant system (1).

Description

[0001] Coolant System and Vehicle

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to a coolant system for a vehicle. The present disclosure further relates to a vehicle comprising a coolant system.

[0004] BACKGROUND

[0005] Electrified vehicles provide numerous advantages over traditional internal combustion engine vehicles, particularly in terms of reduced local emissions and improved energy efficiency. Pure electric vehicles rely exclusively on electric propulsion, eliminating the need for internal combustion engines and thus producing no emissions where they are used. Hybrid electric vehicles, which combine an internal combustion engine with an electric drive system, offer flexibility by allowing operation in electric-only mode for certain distances, which can reduce emissions and fuel consumption. However, alongside these advantages come new technical challenges, especially regarding the effective management of heat in complex coolant systems.

[0006] In electric vehicles, such as pure electric vehicles and hybrid electric vehicles, the electricity is usually stored in an electrical storage system normally comprising a number of battery packs each comprising a number of rechargeable battery cells. Some different types of battery cells are used, such as lithium-ion battery cells, lithium polymer battery cells, as well as other types of rechargeable battery cells. Multiple battery packs are often required to ensure a sufficient available operational range of a vehicle, system voltage and power, especially in battery packs for heavier types of vehicles.

[0007] The temperature of the battery cells of a battery pack affects the performance, safety, and longevity of the battery pack. Therefore, vehicles can comprise a battery coolant circuit configured to regulate the temperature of the battery cells. This circuit typically circulates a coolant fluid through channels in or around the battery packs to absorb excess heat generated during charging and discharging cycles. By preventing overheating, the battery coolant circuit helps to maintain the efficiency of the battery cells and extends their lifespan. Additionally, in colder climates, the coolant circuit can be used to warm the battery cells to ensure efficient operation, as low temperatures can significantly impact battery performance and charging capabilities. Consequently, temperature regulation through a battery coolant circuit can ensure the reliable operation of both pure electric vehicles and hybrid electric vehicles. Traditionally, vehicles have been powered by internal combustion engines, which produce significant amounts of heat as a byproduct. Coolant systems in these vehicles have been designed primarily to manage excess thermal energy, ensuring efficient operation and preventing overheating. With the rise of electrification in the automotive industry, including both pure electric vehicles and hybrid electric vehicles, the demands on coolant systems have shifted. Instead of simply dissipating waste heat, modern coolant systems must now focus on precise temperature regulation to maintain the optimal performance of components such as batteries and electric motors.

[0008] A critical issue that arises in both conventional and electrified vehicle coolant systems is the presence of air within the coolant circuit. Air trapped in the system can severely impede the ability to efficiently transfer heat, resulting in localized hot spots, reduced overall cooling efficiency, and increased wear on components. These inefficiencies can significantly degrade the performance and longevity of vital systems, such as battery coolant circuits, which are essential for maintaining energy efficiency and reliability in electrified vehicles.

[0009] Coolant systems typically use one or more expansion tanks, wherein deaeration lines are placed in critical areas to guide air toward an expansion tank, where it is separated from the coolant. This system works well in relatively simple environments where air can naturally rise to the highest points and be efficiently removed. However, with the growing trend toward electrified vehicles, the complexity of coolant systems has increased.

[0010] For example, heavier vehicles require large numbers of battery packs to ensure sufficient performance, range, and system voltage. These battery packs are often distributed throughout the vehicle to maximize available space, resulting in more intricate coolant system installations that may be challenging to deaerate effectively and efficiently. Moreover, such coolant systems tend to increase manufacturing and assembly costs of vehicles and often lead to space-demanding and complex conduit routing. Additionally, such coolant systems are usually challenging and expensive to modify or adjust so that they can work with different models and types of vehicles. In other words, adapting a coolant system designed for one vehicle to another vehicle often requires significant effort and costs.

[0011] SUMMARY

[0012] It is an object of the present invention to overcome, or at least alleviate, at least some of the above-mentioned problems and drawbacks. The object is achieved by the subject-matter of the appended independent claim(s). According to a first aspect of the present disclosure, the object is achieved by a coolant system for a vehicle, wherein the coolant system is configured to be mounted to the vehicle such that a vertical direction thereof coincides with a vertical direction of the vehicle. The coolant system comprises a first coolant subsystem configured to regulate the temperature of a first arrangement of the vehicle, and a second coolant subsystem configured to regulate the temperature of a second arrangement of the vehicle. The coolant system further comprises a first static line connected to the first coolant subsystem, a second static line connected to the second coolant subsystem, an expansion vessel, a deaeration line connected to the expansion vessel, and a deaeration junction connecting the first and second static lines to the deaeration line. Each of the first and second static lines comprises a segment adjoining the deaeration junction, wherein the extension direction of each of the segments is inclined upwards toward the deaeration junction, as seen relative to the vertical direction of the coolant system, with an inclination angle within the range of 7 - 70 degrees, or within the range of 20 - 50 degrees, as measured relative to a plane perpendicular to the vertical direction of the coolant system.

[0013] Thereby, a coolant system is provided having conditions for a quick and effective deaeration of the first and second coolant subsystems via the first and second static lines respectively. This is because each of the first and second static lines comprises a segment adjoining the deaeration junction, wherein the extension direction of each of the segments is inclined upwards toward the deaeration junction, as seen relative to the vertical direction of the coolant system, with an inclination angle within the range of 7 - 70 degrees, or within the range of 20 - 50 degrees. Tests and simulations have shown that an inclination angle of the respective segment within these ranges can ensure a quick and efficient transport of air bubbles in the direction towards the deaeration junction. The tests and simulations also indicate that the capacity of transporting air bubbles with an inclination angle within these ranges even surpasses that of a vertically oriented segment. This is assumed to be related to the fact that larger bubbles are easier to separate, and the inclination angles of the segments ensure that smaller bubbles move to the top of the segments due to their natural tendency to rise, driven by gravity and the density difference between air and coolant, where they merge into larger bubbles due to their surface tension. As a result, these larger bubbles can flow faster and more easily toward the deaeration junction.

[0014] Moreover, by utilizing the first and second static lines for deaerating the first and second coolant subsystems, the need for arranging several deaeration lines between the expansion vessel and different parts of the first and second coolant subsystems is reduced, which thus can provide a less complex and costly coolant system while ensuring quick and efficient deaeration of the first and second coolant subsystems. In addition, a coolant system is provided having conditions for facilitated routing of conduits while ensuring quick and efficient deaeration of the first and second coolant subsystems. Furthermore, by utilizing the first and second static lines for deaerating the first and second coolant subsystems, the coolant system can be adapted to work with different models and types of vehicles and drivetrains in a simpler and more cost-efficient manner.

[0015] Accordingly, a coolant 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.

[0016] The term “static line” as used herein refers to a coolant line that connects the expansion vessel to the suction side of a coolant pump. The purpose of the static line is to provide a “static”, i.e., non-varying or low-varying, coolant feeding pressure to the suction side of the coolant pump. In this manner, the static line can reduce the risk of steam build-up and cavitation in the coolant pump.

[0017] Optionally, the length of the segment of each of the first and second static lines, as measured along the extension direction thereof, exceeds 10 centimetres. Thereby, quick and efficient transport of air bubbles in the direction towards the deaeration junction can be ensured inside the segment of each of the first and second static lines.

[0018] Optionally, the deaeration line is arranged such that the extension direction thereof has a vector component parallel to the vertical direction of the coolant system along the full length of the deaeration line from the deaeration junction to the expansion vessel. Thereby, it can be ensured that air bubbles can reach the expansion vessel via the deaeration line due to their natural tendency to rise, driven by gravity and the density difference between air and coolant.

[0019] Optionally, the deaeration line comprises a segment adjoining the deaeration junction, and wherein the angle between the extension direction of the segment of the deaeration line and the plane perpendicular to the vertical direction of the coolant system is within the range of 50 - 90 degrees, or is within the range of 75 - 90 degrees. Thereby, it can be ensured that air bubbles reaching the deaeration junction can be transported towards the expansion vessel in a quick and efficient manner. Optionally, the coolant system comprises a conduit assembly comprising the deaeration junction, the segments of the first and second static lines, and a segment of the deaeration line adjoining the deaeration junction, and wherein each end portion of the conduit assembly is provided with a connector. Thereby, a coolant system is provided having improved conditions for quick and cost-efficient adaptation to fit different models and types of vehicles and drivetrains.

[0020] Optionally, each connector is a quick connector, such as a VDA standard quick connector or a SAE standard quick connector. Thereby, conditions are provided for further reduced manufacturing and assembling costs of the coolant system. In addition, service, repair, and maintenance of the coolant system may be facilitated.

[0021] Optionally, each of the first and second static lines is arranged such that the extension direction thereof has a vector component parallel to the vertical direction of the coolant system along the full length of the static line from the first and second coolant subsystems respectively to the deaeration junction. Thereby, it can be ensured that air bubbles from the first and second coolant subsystems can reach the deaeration junction due to their natural tendency to rise, driven by gravity and the density difference between air and coolant.

[0022] Optionally, the coolant system comprises a first deaeration conduit with an inlet connected to the first coolant subsystem and an outlet connected to one static line of the first and second static lines. Thereby, fast and efficient deaeration of the first coolant subsystem can be further ensured while circumventing the need for connecting the outlet of the first deaeration conduit to the expansion vessel. In this manner, the routing of conduits can be further facilitated and conditions are provided for a less complex coolant system while ensuring quick and efficient deaeration of various parts of the coolant system.

[0023] Optionally, the outlet of the first deaeration conduit is connected to the segment of the static line. Thereby, it can be ensured that air bubbles that enter the segment via the outlet of the first deaeration conduit are quickly and efficiently transported towards the deaeration junction.

[0024] Optionally, the effective cross sectional area of the first deaeration conduit is less than half of the effective cross sectional area of the static line. Thereby, the routing of the first deaeration conduit is facilitated because conditions are provided for arranging the first deaeration conduit such that it passes through a horizontal plane two or more times. This is because the relatively small effective cross sectional area of the first deaeration conduit can ensure that air bubbles can be transported therethrough driven by the flow of coolant through the first deaeration conduit rather than by gravity.

[0025] Optionally, the coolant system comprises a valve controllable between an open state, in which the valve allows fluid flow through the first deaeration conduit, and a closed state, in which the valve blocks fluid flow through the first deaeration conduit. Thereby, a coolant system is provided having conditions for a controlled deaeration of the first coolant subsystem.

[0026] Optionally, the coolant system comprises a second deaeration conduit with an inlet connected to the second coolant subsystem and an outlet connected to the expansion vessel. Thereby, a coolant system is provided having conditions for mixing coolant between the first and second coolant subsystems while ensuring quick and efficient deaeration of the first and second coolant subsystems respectively.

[0027] Optionally, one of the first and second arrangements of the vehicle is a propulsion battery, and wherein the other of the first and second arrangements of the vehicle is an electric propulsion motor or power electronics. Thereby, coolant system is provided capable of controlling the temperature of the propulsion battery and electric propulsion motor or power electronics while ensuring quick and efficient deaeration of the first and second coolant subsystems of the coolant system.

[0028] According to a second aspect of the present disclosure, the object is achieved by a vehicle comprising a coolant system according to the first aspect of the present disclosure. Since the vehicle comprises a coolant system according to the first aspect of the present disclosure, a vehicle is provided having conditions for quick and effective deaeration while reducing the need for arranging several deaeration lines between the expansion vessel and different parts of the first and second coolant subsystems. In other words, a vehicle is provided having conditions for a less complex and costly coolant system. In addition, a vehicle is provided having conditions for facilitated routing of conduits while ensuring quick and efficient deaeration of the first and second coolant subsystems of the coolant system.

[0029] 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. Optionally, the vehicle is a heavy wheeled vehicle, such as a truck or a bus. Thereby, a heavy wheeled vehicle is provided having at least some of the above mentioned advantages.

[0030] It will be appreciated that the various embodiments described for the method are all combinable with the control arrangement as described herein. That is, the control arrangement according to the fourth aspect of the invention may be configured to perform any one of the method steps of the method according to the first aspect of the invention.

[0031] Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following detailed description.

[0032] BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Various aspects of the present disclosure, 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:

[0034] Fig. 1 schematically illustrates a vehicle according to some embodiments,

[0035] Fig. 2 schematically illustrates a coolant system of the vehicle illustrated in Fig. 1 , and Fig. 3 illustrates an enlarged view of a conduit assembly of the coolant system illustrated in Fig. 2.

[0036] DETAILED DESCRIPTION

[0037] Aspects of the present disclosure will now be described more fully. Like reference signs refer to like elements throughout. Well-known functions or constructions will not necessarily be described in detail for brevity and / or clarity.

[0038] Fig. 1 schematically illustrates a vehicle 2 according to some embodiments. According to the illustrated embodiments, the vehicle 2 is a truck, i.e. , a type of heavy wheeled vehicle, as well as a type of heavy commercial vehicle. According to further embodiments, the vehicle 2, as referred to herein, may be another type of heavy or lighter type of manned or unmanned vehicle for land-based propulsion such as a lorry, a construction vehicle, a tractor, a bus, a car, or the like.

[0039] The vehicle 2 comprises an electric propulsion system 10 configured to provide motive power to the vehicle 2 via wheels 27 of the vehicle 2. For reasons of brevity and clarity, the electric propulsion system 10 is in some places herein simply referred to as the “propulsion system 10”. The wording “electric propulsion system” as used herein, means that the propulsion system 10 of the vehicle 2 may be a fully electric propulsion system, comprising one or more electric machines as the only means of providing propulsion power to the vehicle 2, or a partially electric powertrain, comprising one or more electric machines combined with a further power unit for providing propulsion power to the vehicle 2. The partially electric powertrain may also be referred to as a hybrid electric powertrain and the further power unit referred to above may for example comprise an internal combustion engine.

[0040] The propulsion system 10 comprises an electric propulsion machine 12’ for providing motive power to the vehicle 2. According to the illustrated embodiments, the electric propulsion machine 12’ is configured to provide motive power to the vehicle 2 via a transmission 33 and wheels 27 of the vehicle 2. The electric propulsion machine 12’ may also be referred to as a propulsion machine, an electric motor, an electric propulsion motor, or the like. The vehicle 2 in Fig. 1 is schematically depicted as comprising one electric propulsion machine 12’. However, the propulsion system 10 of the vehicle 2 may comprise two or more electric propulsion machines 12’ each configured to provide motive power to the vehicle 2.

[0041] According to the illustrated embodiments, the propulsion system 10 of the vehicle 2 is a pure electrical propulsion system. However, according to further embodiments, the propulsion system 10 of the vehicle 2 may comprise an internal combustion engine configured to provide motive power to the vehicle 2 in addition to one or more electric propulsion machines 12, as indicated above, or as an alternative to the one or more electric propulsion machines 12.

[0042] According to the illustrated embodiments, the vehicle 2 is a wheeled vehicle comprising a number of wheels 27, 27’. According to the embodiments illustrated in Fig. 1 , the vehicle 2 comprises two driven wheels 27 which constitute rear-wheels of the vehicle 2. The vehicle 2 further comprises two non-driven wheels 27’, which according to the illustrated embodiments constitute front-wheels of the vehicle 2. In other words, in these embodiments, the electric machine 12 is configured to provide motive power to the vehicle 2 via the driven wheels 27 of the vehicle 2. However, according to further embodiments, the vehicle 2 may comprise another configuration of driven and non-driven wheels.

[0043] In Fig. 1 , the vehicle 2 is illustrated as positioned in an intended use position on a flat surface 51 supporting the vehicle 2. As seen in Fig. 1 , the wheels 27, 27’ of the vehicle 2 abut against the flat surface 51 when the vehicle 2 is positioned in the intended use position thereon. Moreover, in Fig. 1, a forward moving direction fd and a reverse moving direction rd of the vehicle 2 are indicated. The reverse moving direction rd of the vehicle 2 is opposite to the forward moving direction fd of the vehicle 2.

[0044] Furthermore, in Fig. 1 , a longitudinal direction Id of the vehicle 2 is indicated. The longitudinal direction Id of the vehicle 2 is parallel to a flat surface 51 supporting the vehicle 2 when the vehicle 2 is positioned in the intended upright use position thereon. Moreover, the longitudinal direction Id of the vehicle 2 is parallel to the forward moving direction fd of the vehicle 2 as well as to the reverse moving direction rd of the vehicle 2. A vertical direction vd of the vehicle 2 is also indicated in Fig. 1. The vertical direction vd of the vehicle 2 is perpendicular to the longitudinal direction Id of the vehicle 2. Moreover, when the vehicle 2 is positioned in the intended use position on a flat horizontal surface, the vertical direction vd of the vehicle 2 coincides with a gravity vector gv at the location of the vehicle 2.

[0045] The number of wheels 27, 27’ of the vehicle 2 is supported relative to a chassis 40 of the vehicle 2 via wheel axles. According to some embodiments, the vehicle 2 may comprise a wheel suspension system resiliently suspending the wheels 27, 27’ of the vehicle 2 relative to the chassis. The chassis 40 of the vehicle 2 serves as a structural framework that supports other components and systems of the vehicle 2, such as the propulsion system 10 and a cab 45 of the vehicle 2.

[0046] That is, as is seen in Fig. 1, according to the illustrated embodiments, the vehicle 2 comprises a cab 45. According to the illustrated embodiments, the cab 45 is resiliently suspended relative to the chassis 40. The cab 45 accommodates an occupant compartment 55. The occupant compartment 55 is arranged to accommodate one or more vehicle occupants, such as a driver and possibly one or more passengers. According to the illustrated embodiments, the occupant compartment 55 also comprises a driver environment of the vehicle 2. The term "driver environment” refers to the area within the vehicle 2 where a driver operates and controls the vehicle 2. The driver environment typically includes the driver's seat, steering wheel, pedals, dashboard, and other control interfaces and displays that the driver may use to manage the functions of the vehicle 2.

[0047] The vehicle 2 comprises a coolant system 1. As is further explained herein, the coolant system 1 comprises a first coolant subsystem configured to regulate the temperature of a first arrangement 11 of the vehicle 2 and a second coolant subsystem configured to regulate the temperature of a second arrangement 12 of the vehicle 2. According to the illustrated embodiments, the first arrangement 11 is a propulsion battery 1 T of the vehicle 2 and the second arrangement 12 is the electric propulsion machine 12’ of the vehicle 2. However, according to further embodiments, the first arrangement 11, as referred to herein, may be another type of arrangement, such as for example an electric propulsion machine 12’, an internal combustion engine, power electronics 14, a heat exchanger, a heater for the occupant compartment 55, or the like. Likewise, according to further embodiments, the second arrangement 12, as referred to herein, may be another type of arrangement than the electric propulsion machine 12’, such as for example propulsion battery 11’, an internal combustion engine, power electronics 14, a heat exchanger, a heater for the occupant compartment 55, or the like.

[0048] The propulsion battery 1 T is configured to provide electricity to the electric machine 12 of the propulsion system 10 of the vehicle 2. The vehicle 2 further comprises power electronics 14 configured to regulate the transfer of electricity between the electric machine 12 and the propulsion battery 1 T. The propulsion battery 1 T may comprise a number of rechargeable battery cells, such as lithium-ion battery cells, lithium polymer battery cells, nickel-metal hydride battery cells, sodium-ion battery cells, or the like.

[0049] In Fig. 1 , the vehicle 2 is illustrated as comprising one propulsion battery 1 T in the form of a battery pack. The vehicle 2 may comprise one or more further propulsion batteries arranged at different locations on the vehicle 2. Each propulsion battery 1 T may comprise a number of battery layers each comprising a number of battery modules, wherein each battery module may comprise a number of rechargeable battery cells. According to embodiments herein, the propulsion battery 1 T has a nominal voltage within the so-called Voltage Class B, usually abbreviated VCB, namely a nominal voltage equal to, or higher than, 60 volts. The wording propulsion battery 1 T, as referred to herein, may encompass one battery pack, one layer of battery cells, or one battery module according to the above.

[0050] Fig. 2 schematically illustrates the coolant system 1 of the vehicle 2 illustrated in Fig. 1. Below, simultaneous reference is made to Fig. 1 and Fig. 2, if not indicated otherwise.

[0051] The coolant system 1 is configured to be mounted to the vehicle 2 such that a vertical direction vd’ thereof coincides with a vertical direction vd of the vehicle 2. That is, in Fig. 2, the vertical direction vd’ of the coolant system 1 is indicated. As understood from the above described, the vertical direction vd’ of the coolant system 1 coincides with the vertical direction vd of the vehicle 2 when the coolant system 1 is mounted to the vehicle 2. Moreover, as understood from the above described, the vertical direction vd’ of the coolant system 1 coincides with a local gravity vector gv when the coolant system 1 is mounted to the vehicle 2 and the vehicle 2 is positioned in the use position on a flat horizontal surface as depicted in Fig. 1.

[0052] The coolant system 1 comprises a first coolant subsystem cs1 configured to regulate the temperature of the first arrangement 11 of the vehicle 2, i.e., the propulsion battery 1 T according to the illustrated embodiments. The first coolant subsystem cs1 may also be referred to as a first coolant circuit. The first coolant subsystem cs1 comprises sections in heat exchanging contact with the first arrangement 11 and a first coolant pump p1 configured to pump coolant through the first coolant subsystem cs1.

[0053] Moreover, according to the illustrated embodiments, the first coolant subsystem cs1 comprises a first radiator r1 configured to dissipate heat from coolant in the first coolant subsystem cs1 to the surroundings. As indicated in Fig. 1, the first radiator r1 may be arranged at a front portion of the vehicle 2 to be subjected to a flow of air generated upon movement of the vehicle 2 in the forward moving direction fd thereof. As an alternative, or in addition, the vehicle 2 may comprise a fan configured to generate an airflow through the first radiator r1. The first coolant subsystem cs1 further comprises a bypass line b1, which bypasses the first radiator r1, and a first valve t1 that can be controlled to direct coolant through the first radiator r1, the bypass line b1, or both. The first valve t1 of the first coolant subsystem cs1 may also be referred to as a thermostatic valve. Moreover, the bypass line b1 of the first coolant subsystem cs1 may also be referred to as a first bypass line.

[0054] The coolant system 1 comprises a second coolant subsystem cs2 configured to regulate the temperature of the second arrangement 12 of the vehicle 2, i.e., the electric propulsion machine 12’ according to the illustrated embodiments. The second coolant subsystem cs2 may also be referred to as a second coolant circuit. The second coolant subsystem cs2 comprises sections in heat exchanging contact with the second arrangement 12 and a second coolant pump p2 configured to pump coolant through the second coolant subsystem cs2.

[0055] Moreover, according to the illustrated embodiments, the second coolant subsystem cs2 comprises a second radiator r2 configured to dissipate heat from coolant in the second coolant subsystem cs2 to the surroundings. As indicated in Fig. 1 , the second radiator r2 may be arranged at a front portion of the vehicle 2 to be subjected to a flow of air generated upon movement of the vehicle 2 in the forward moving direction fd thereof. As an alternative, or in addition, the vehicle 2 may comprise a fan configured to generate an airflow through the second radiator r2. The second coolant subsystem cs2 further comprises a bypass line b2, which bypasses the second radiator r2, and a second valve t2 that can be controlled to direct coolant through the second radiator r2, the bypass line b2, or both. The second valve t2 of the second coolant subsystem cs2 may also be referred to as a thermostatic valve. Moreover, the bypass line b2 of the second coolant subsystem cs2 may also be referred to as a second bypass line.

[0056] The coolant system 1 further comprises a first static line S1 connected to the first coolant subsystem cs1 and a second static line S2 connected to the second coolant subsystem cs2. Furthermore, the coolant system 1 comprises an expansion vessel 19, a deaeration line 3 connected to the expansion vessel 19, and a deaeration junction 7 connecting the first and second static lines S1, S2 to the deaeration line 3. The expansion vessel 19 may also be referred to as an expansion tank, a coolant reservoir, or the like.

[0057] The term “static line S1 , S2” as used herein refers to a coolant line that connects the expansion vessel 17 to the suction side of the coolant pumps of the first and second coolant subsystem cs1 , cs2, i.e., the first and second coolant pumps p1, p2 referred to above. The purpose of the static lines S1, S2 is to provide a “static”, i.e., non-varying or low-varying, coolant feeding pressure to the suction side of the coolant pumps p1 , p2. In this manner, the static lines S1, S2 can reduce the risk of steam build-up and cavitation in the coolant pumps p1, p2.

[0058] Each of the first and second static lines S1, S2 comprises a segment ST, S2’ adjoining the deaeration junction 7. Likewise, the deaeration line 3 comprises a segment 3’ adjoining the deaeration junction 7. In this context, the term “adjoining” refers to the segments ST, S2’, and 3’ being arranged such that at least part of each segment ST, S2’, 3’ is directly adjacent to, or in close proximity to, the deaeration junction 7.

[0059] According to the embodiments illustrated in Fig. 2, the coolant system 1 comprises a conduit assembly 17 comprising the deaeration junction 7, the segments ST, S2’ of the first and second static lines S1, S2, and the segment 3’ of the deaeration line 3 adjoining the deaeration junction 7. Moreover, according to these embodiments, each end portion of the conduit assembly 17 is provided with a connector c1, c2, c3, c4. The purpose and advantages with the connectors c1, c2, c3, c4 are explained in greater detail below.

[0060] Fig. 3 illustrates an enlarged view of the conduit assembly 17 of the coolant system 1 illustrated in Fig. 2. Below, simultaneous reference is made to Fig. 1 - Fig. 3, if not indicated otherwise. As indicated above, the conduit assembly 17 comprises the deaeration junction 7, the segments ST, S2’ of the first and second static lines S1, S2, and the segment 3’ of the deaeration line 3 adjoining the deaeration junction 7. In Fig. 3, the vertical direction vd’ of the coolant system 1 is indicated and the conduit assembly 17 is illustrated in an intended mounting orientation relative to the vertical direction vd’ of the coolant system 1.

[0061] The extension direction ed1, ed2 of each of the segments ST, S2’ of the first and second static lines S1 , S2 is indicated in Fig. 3. The extension direction ed1, ed2 refers the orientation or path along which the segment ST, S2’ extends. The length of the segment ST, S2’ of each of the first and second static lines S1 , S2, as measured along the extension direction ed1, ed2 thereof, may exceed 10 centimetres or may exceed 15 centimetres.

[0062] According to embodiments herein, the extension direction ed1, ed2 of each of the segments ST, S2’ is inclined upwards toward the deaeration junction 7, as seen relative to the vertical direction vd’ of the coolant system 1, with an inclination angle a1, a2 of approximately 30 degrees as measured relative to a plane hp perpendicular to the vertical direction vd’ of the coolant system 1. According to further embodiments, each of the segments ST, S2’ may be inclined upwards toward the deaeration junction 7, as seen relative to the vertical direction vd’ of the coolant system 1 , with an inclination angle a1 , a2 within the range of 7 - 70 degrees, or within the range of 20 - 50 degrees as measured relative to the plane hp perpendicular to the vertical direction vd’ of the coolant system 1.

[0063] In this manner, a coolant system 1 is provided having conditions for a quick and effective deaeration of the first and second coolant subsystems cs1, cs2 via the first and second static lines S1 , S2 respectively. Tests and simulations have shown that an inclination angle a1, a2 of the respective segment ST, S2’ within these ranges can ensure a quick and efficient transport of air bubbles in the direction towards the deaeration junction 7. The tests and simulations also indicate that the capacity of transporting air bubbles with an inclination angle a1 , a2 within these ranges even surpasses that of a vertically oriented segment. This is assumed to be related to the fact that larger bubbles are easier to separate, and the inclination angles a1 and a2 ensure that smaller bubbles move to the top of the segments ST and S2’, where they merge into larger bubbles due to their surface tension. As a result, these larger bubbles can flow faster and more easily toward the deaeration junction 7.

[0064] Moreover, due to the inclination angles a1, a2 within the herein specified ranges, it can be ensured that the extension direction ed1 , ed2 of each of the segments ST, S2’ obtains a vector component parallel to a local gravity vector gv also when the vehicle 2 comprising the coolant system 1 is positioned on inclined support surfaces. Thereby, it can be ensured that air bubbles can reach the deaeration junction 7 via the segments ST, S2’ due to their natural tendency of air bubbles to rise in a coolant, driven by gravity and the density difference between air and coolant.

[0065] According to still further embodiments, each of the segments ST, S2’ may be inclined upwards toward the deaeration junction 7, as seen relative to the vertical direction vd’ of the coolant system 1, with an inclination angle a1, a2 within the range of 25 - 35 degrees as measured relative to the plane hp perpendicular to the vertical direction vd’ of the coolant system 1.

[0066] Tests and simulations have shown that an inclination angle a1, a2 of the respective segment ST, S2’ within the range of 25 - 35 degrees can further speed up and enhance the transport of air bubbles in the direction towards the deaeration junction 7. Accordingly, in this manner, a quick and effective deaeration of the first and second coolant subsystems cs1, cs2 can be further ensured via the first and second static lines S1, S2 respectively.

[0067] Moreover, due to the inclination angles a1, a2 within the range of 25 - 35 degrees, it can be ensured that the extension direction ed1, ed2 of each of the segments ST, S2’ obtains a vector component parallel to a local gravity vector gv also when the vehicle 2 comprising the coolant system 1 is positioned on inclined support surfaces. Thereby, it can be further ensured that air bubbles can reach the deaeration junction 7 via the segments ST, S2’ due to their natural tendency of air bubbles to rise in a coolant, driven by gravity and the density difference between air and coolant.

[0068] According to the illustrated embodiments, the angle a3 between the extension direction ed3 of the segment 3’ of the deaeration line 3 and the plane hp perpendicular to the vertical direction vd’ of the coolant system 1 is 90 degrees. In other words, according to the illustrated embodiments, the extension direction ed3 of the segment 3’ of the deaeration line 3 is parallel to the vertical direction vd’ of the coolant system 1. This may also be expressed as that the segment 3’ of the deaeration line 3 is a vertically oriented segment. However, according to further embodiments, the angle a3 between the extension direction ed3 of the segment 3’ of the deaeration line 3 and the plane hp perpendicular to the vertical direction vd’ of the coolant system 1 may be within the range of 50 - 90 degrees, or may be within the range of 75 - 90 degrees. According to the illustrated embodiments, the deaeration line 3 is arranged such that the extension direction ed3 thereof has a vector component parallel to the vertical direction vd’ of the coolant system 1 along the full length of the deaeration line 3 from the deaeration junction 7 to the expansion vessel 19. Thereby, it can be ensured that air bubbles can reach the expansion vessel 19 via the deaeration line 3 due to their natural tendency to rise, driven by gravity and the density difference between air and coolant.

[0069] Furthermore, according to the illustrated embodiments, each of the first and second static lines S1 , S2 is arranged such that the extension direction ed1, ed2 thereof has a vector component parallel to the vertical direction vd’ of the coolant system 1 along the full length of the static line S1, S2 from the first and second coolant subsystems cs1 , cs2 respectively to the deaeration junction 7. Like above, in this manner, it can be ensured that air bubbles from the first and second coolant subsystems cs1, cs2 can reach the deaeration junction 7 due to their natural tendency to rise, driven by gravity and the density difference between air and coolant.

[0070] According to the embodiments illustrated in Fig. 2, the coolant system 1 comprises a first deaeration conduit d1 with an inlet dT connected to the first coolant subsystem cs1 and an outlet d1” connected to the segment S2’ of the second static line S2. According to further embodiments, the outlet d1” of the first deaeration conduit d1 may be connected to another part of the second static line S2, or to the first static line S1, for example the segment ST of the first static line S1.

[0071] A segment s4 of the first deaeration conduit d1 is indicated in Fig. 3. In other words, according to the illustrated embodiments, the conduit assembly 17 comprises the segment s4 of the first deaeration conduit d1. As is best seen in Fig. 3, the outlet d1” of the first deaeration conduit d1 is connected to a side portion of the second static line S2 with respect to the vertical direction vd’ of the coolant system 1. According to further embodiments, the outlet d1” of the first deaeration conduit d1 may be connected to a bottom portion of the second static line S2 with respect to the vertical direction vd’ of the coolant system 1. In this manner, the entry of air bubbles into the outlet d1” of the first deaeration conduit d1 can be avoided, for example originating from the second coolant subsystem cs2.

[0072] As mentioned above, each end portion of the conduit assembly 17 is provided with a connector c1, c2, c3, c4. That is, in more detail, the segment ST of the first static line S1 comprises a connector c1 arranged at a distal end of the segment ST. Likewise, the segment S2’ of the second static line S2 comprises a connector c2 arranged at a distal end of the segment S2’. Furthermore, the segment 3’ of the deaeration line 3 comprises a connector c3 arranged at a distal end of the segment 3’. Moreover, according to the illustrated embodiments, the segment s4 of the first deaeration conduit d1 comprises a connector c4 arranged at a distal end of the segment s4. Each connector c1, c2, c3, c4 may be a quick connector, such as a VDA standard quick connector or a SAE standard quick connector.

[0073] Since the coolant system 1 comprises the conduit assembly 17, the coolant system 1 can be adapted to work with different models and types of vehicles and drivetrains in a simpler and more cost-efficient manner. Moreover, due to the connectors c1, c2, c3, c4 of the conduit assembly 17, conditions are provided for further reduced manufacturing and assembling costs of the coolant system 1, and thus also a vehicle 2 comprising the coolant system 1. In addition, service, repair, and maintenance of the coolant system 1 and of a vehicle 2 comprising the coolant system 1 may be facilitated.

[0074] According to the embodiments illustrated in Fig. 2, the coolant system 1 comprises a second deaeration conduit d2 with an inlet d2’ connected to the second coolant subsystem cs2 and an outlet d2” connected to the expansion vessel 19. Moreover, according to the illustrated embodiments, the coolant system 1 comprises a valve v1 controllable between an open state, in which the valve v1 allows fluid flow through the first deaeration conduit d1 , and a closed state, in which the valve v1 blocks fluid flow through the first deaeration conduit d1. Thereby, a coolant system 1 is provided having conditions for mixing coolant between the first and second coolant subsystems cs1, cs2 while ensuring fast and efficient deaeration of the first and second coolant subsystems cs1, cs2 respectively.

[0075] As can be seen in Fig. 2 and Fig. 3, according to the illustrated embodiments, the effective cross sectional area of the first deaeration conduit d1 is considerably smaller than the effective cross sectional area of the static line S2. According to some embodiments, the effective cross sectional area of the first deaeration conduit d1 is less than half of the effective cross sectional area of the static line S2 or is less than 30% of the effective cross sectional area of the static line S2. In this manner, the routing of the first deaeration conduit d1 is facilitated because conditions are provided for arranging the first deaeration conduit d1 such that it passes through a horizontal plane two or more times. According to the embodiments illustrated in Fig. 2, the first deaeration conduit d1 is routed such that it passes through a horizontal plane twice. The first deaeration conduit d1 can be routed in this manner, while ensuring efficient deaeration through the first deaeration conduit d1, because the relatively small effective cross sectional area of the first deaeration conduit can ensure that air bubbles can be transported therethrough driven by the flow of coolant through the first deaeration conduit d1 rather than by gravity.

[0076] The term “coolant” as used herein, is intended to encompass liquid coolant, such as a mixture of water and glycol. Therefore, the term “coolant”, as used herein, may be replaced by the term “liquid coolant”.

[0077] A coolant system 1, as referred to herein, is a system utilizing coolant to manage the temperature of one or more arrangements 11, 12 of the vehicle 2. The wording “manage the temperature of” means that the coolant system 1 may be configured to cool and / or heat the one or more arrangements 11, 12 of the vehicle 2. In some embodiments, the coolant system

[0078] I, as referred to herein, may be specifically intended for cooling one or more arrangements

[0079] I I , 12 of the vehicle 2. In such embodiments, the coolant system 1 , as referred to herein, may also be referred to as a cooling system. Similarly, one or both of the first and second coolant subsystems cs1 , cs2 may be specifically intended for cooling an arrangement 11, 12 of the vehicle 2 and may thus also be referred to as a cooling subsystem.

[0080] It is to be understood that the foregoing is illustrative of various example embodiments and that the invention is defined only by the appended independent 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 independent claims.

[0081] 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.

Claims

CLAIMS1. A coolant system (1) for a vehicle (2), wherein the coolant system (1) is configured to be mounted to the vehicle (2) such that a vertical direction (vd’) thereof coincides with a vertical direction (vd) of the vehicle (2), wherein the coolant system (1) comprises: a first coolant subsystem (cs1) configured to regulate the temperature of a first arrangement (11) of the vehicle (2), a second coolant subsystem (cs2) configured to regulate the temperature of a second arrangement (12) of the vehicle (2), a first static line (S1) connected to the first coolant subsystem (cs1), a second static line (S2) connected to the second coolant subsystem (cs2), an expansion vessel (19), a deaeration line (3) connected to the expansion vessel (19), and a deaeration junction (7) connecting the first and second static lines (S1 , S2) to the deaeration line (3), wherein each of the first and second static lines (S1, S2) comprises a segment (ST, S2’) adjoining the deaeration junction (7), and wherein the extension direction (ed1, ed2) of each of the segments (ST, S2’) is inclined upwards toward the deaeration junction (7), as seen relative to the vertical direction (vd’) of the coolant system (1), with an inclination angle (a1 , a2) within the range of 7 - 70 degrees, or within the range of 20 - 50 degrees, as measured relative to a plane (hp) perpendicular to the vertical direction (vd’) of the coolant system (1).

2. The coolant system (1) according to claim 1, wherein the length of the segment (ST, S2’) of each of the first and second static lines (S1 , S2), as measured along the extension direction (ed1, ed2) thereof, exceeds 10 centimetres.

3. The coolant system (1) according to claim 1 or 2, wherein the deaeration line (3) is arranged such that the extension direction (ed3) thereof has a vector component parallel to the vertical direction (vd’) of the coolant system (1) along the full length of the deaeration line (3) from the deaeration junction (7) to the expansion vessel (19).

4. The coolant system (1) according to any one of the preceding claims, wherein the deaeration line (3) comprises a segment (3’) adjoining the deaeration junction (7), and wherein the angle (a3) between the extension direction (ed3) of the segment (3’) of the deaeration line (3) and the plane (hp) perpendicular to the vertical direction (vd’) of the coolant system (1) is within the range of 50 - 90 degrees, or is within the range of 75 - 90 degrees.

5. The coolant system (1) according to any one of the preceding claims, wherein the coolant system (1) comprises a conduit assembly (17) comprising the deaeration junction (7), the segments (ST, S2’) of the first and second static lines (S1, S2), and a segment (3’) of the deaeration line (3) adjoining the deaeration junction (7), and wherein each end portion of the conduit assembly (17) is provided with a connector (c1 , c2, c3, c4).

6. The coolant system (1) according to claim 5, wherein each connector (c1 , c2, c3, c4) is a quick connector, such as a VDA standard quick connector or a SAE standard quick connector.

7. The coolant system (1) according to any one of the preceding claims, wherein each of the first and second static lines (S1, S2) is arranged such that the extension direction (ed1, ed2) thereof has a vector component parallel to the vertical direction (vd’) of the coolant system (1) along the full length of the static line (S1 , S2) from the first and second coolant subsystems (cs1, cs2) respectively to the deaeration junction (7).

8. The coolant system (1) according to any one of the preceding claims, wherein the coolant system (1) comprises a first deaeration conduit (d1) with an inlet (dT) connected to the first coolant subsystem (cs1) and an outlet (d1 ”) connected to one static line (S2) of the first and second static lines (S2).

9. The coolant system (1) according to claim 8, wherein the outlet (d1 ”) of the first deaeration conduit (d1) is connected to the segment (S2’) of the static line (S2).

10. The coolant system (1) according to any one of the claims 8 or 9, wherein the effective cross sectional area of the first deaeration conduit (d 1 ) is less than half of the effective cross sectional area of the static line (S2).

11. The coolant system (1) according to any one of the claims 8 - 10, wherein the coolant system (1) comprises a valve (v1) controllable between an open state, in which the valve (v1) allows fluid flow through the first deaeration conduit (d 1 ), and a closed state, in which the valve (v1) blocks fluid flow through the first deaeration conduit (d1).

12. The coolant system (1) according to any one of the preceding claims, wherein the coolant system (1) comprises a second deaeration conduit (d2) with an inlet (d2’) connected to the second coolant subsystem (cs2) and an outlet (d2”) connected to the expansion vessel (19).

13. The coolant system (1) according to any one of the preceding claims, wherein one of the first and second arrangements (11, 12) of the vehicle (2) is a propulsion battery (1 T), and wherein the other of the first and second arrangements (12) of the vehicle (2) is an electric propulsion machine (12’) or power electronics (14).

14. A vehicle (2) comprising a coolant system (1) according to any one of the preceding claims.

15. The vehicle (2) according to claim 14, wherein the vehicle (2) is a heavy wheeled vehicle, such as a truck or a bus.

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