GB2581475A

GB2581475A - Engine cooling circuit and method of cooling an engine

Info

Publication number: GB2581475A
Application number: GB1901967.8A
Authority: GB
Inventors: Richard Hutchins William
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2019-02-13
Filing date: 2019-02-13
Publication date: 2020-08-26
Anticipated expiration: 2039-02-13
Also published as: GB201901967D0; GB2581475B

Abstract

A flow control valve assembly for an engine cooling circuit comprises first inlet and outlet ports 142,144 for coolant flow from/to an engine 110 and second inlet and outlet ports 148,146 for coolant flow from/to a radiator 120. The first outlet port and second inlet port are above the first inlet port in use. A flow diverter portion 140D has a first configuration where coolant flows from the first inlet port to the first outlet port, and second configuration where coolant flows from the first inlet port to the second outlet port and from the second inlet port to the first outlet port. An upper region of the valve assembly may have a degas tank inlet 149. When the valve assembly is operated in the first configuration, gas bubbles entrained in coolant leaking past ‘F2’ the flow diverter portion can rise through the degas tank inlet to a degas tank 170. A method of cooling an engine comprises controlling a flow control valve to cause coolant fluid to circulate through the engine but substantially not through a radiator and a degas tank, or to cause coolant fluid to circulate through the engine, the radiator and the degas tank.

Description

ENGINE COOLING CIRCUIT AND METHOD OF COOLING AN ENGINE

TECHNICAL FIELD

The present disclosure relates to a motor vehicle cooling circuit and method. Aspects of the invention relate to at least a flow control valve assembly, an engine cooling circuit, a control system, a motor vehicle and a method.

BACKGROUND

It is known to provide a cooling system (or cooling circuit) for cooling an engine of a motor vehicle. Cooling systems typically include a thermostatic pressure relief valve that controls the flow of coolant fluid through a radiator of the cooling system in order to maintain the coolant fluid, and therefore the engine, at an acceptable temperature. Thermostatic pressure relief valves are typically of the wax pellet type and arranged such that a valve permitting flow of coolant fluid through the radiator is opened by thermal expansion of a wax pellet at a predetermined coolant fluid temperature, the predetermined temperature being determined by the construction of the valve and thermal expansion properties of the wax pellet.

It is known to provide a cooling system degas tank to permit expulsion of gas that becomes trapped within the cooling system. The degas tank is partially filled with coolant fluid, and partially with air, and a flow of coolant fluid within the cooling system through the degas tank is permitted in a parallel flow arrangement with coolant fluid flowing through another portion of the cooling system.

The present applicant has recognised that the presence of the degas tank in the cooling system can reduce the rate of engine coolant fluid warming following start-up from cold.

It is an aim of the present invention to address disadvantages associated with the prior art.

SUMMARY OF THE INVENTION

Aspects of the invention relate to a flow control valve, a method, a control system and a vehicle. Embodiments of the invention may be understood with reference to the appended claims.

In one aspect of the invention for which protection is sought there is provided a flow control valve assembly for an engine cooling circuit. The assembly comprises a first inlet port for receiving a flow of coolant fluid from an engine, a second inlet port for receiving a flow of coolant fluid from a radiator, a first outlet port for delivering a flow of coolant fluid to the engine, a second outlet port for delivering a flow of coolant fluid to the radiator and a flow diverter portion. The flow diverter portion is arranged to direct a flow of coolant fluid from the first inlet port to the first outlet port in a first configuration and to direct a flow of coolant fluid from the first inlet port to the second outlet port in a second configuration and to direct a flow of coolant fluid from the second inlet port to the first outlet port in the second configuration.

In use, the first outlet port is located above the first inlet port and the second inlet port is located above the first inlet port.

Such a flow control valve assembly has the feature that, in use, direct recirculation of coolant fluid from the engine back to the engine may be facilitated in the first configuration.

This has the advantage that the coolant fluid may warm to a required operating temperature relatively rapidly without undue cooling due to flow through other cooling circuit components such as a degas tank, if present.

The feature that the first outlet port is located above the first inlet port and the second inlet port is located above the first inlet port has the advantage that, in some embodiments, when the assembly is operated in the first configuration a vent path may be provided for venting gas bubbles trapped within the cooling circuit. It is to be understood that, in some embodiments, when the valve assembly is operated in the second configuration a proportion of coolant fluid flowing to the radiator may be diverted to flow through a degas tank to promote expulsion of gas trapped within the cooling circuit. Coolant fluid diverted to flow through the degas tank in this manner may be returned to a conduit, carrying coolant fluid that has passed through the radiator, from the radiator to the valve assembly at a location of the conduit that is upstream of the valve assembly. The arrangement may be such that, with the flow control valve assembly in the first configuration, gas bubbles following the leak path for coolant fluid to the opposite side of the flow diverter portion follow a flow path to the degas tank. It is to be understood that this direction of flow of gas bubbles may be against the intended flow of coolant when the valve assembly is in the second configuration. With the valve assembly in the first configuration coolant within the radiator may not be subject to mechanical pumping action. It is to be understood that coolant flow through the cooling circuit may be driven mechanically by an engine driven fluid pump at or near a coolant inlet to or coolant outlet from the engine. Thus, when the valve assembly is in the first configuration, substantially no mechanical pumping action may be experienced by coolant fluid within the radiator.

In a further aspect of the invention for which protection is sought there is provided an engine cooling circuit. The circuit comprises a valve assembly according to the above described aspect of the invention for controlling flow of coolant fluid in the cooling circuit, a radiator for cooling coolant fluid, the radiator having a coolant fluid inlet and a coolant fluid outlet coupled to the second outlet and second inlet ports, respectively, of the valve assembly, and means for receiving gas from the cooling circuit. The cooling circuit comprises control means configured to allow circulation of coolant fluid in a selected one of a first mode of operation in which the valve assembly is operated in the first configuration and permits coolant fluid to circulate through the engine whilst substantially preventing coolant fluid flow through the radiator, or a second mode of operation in which the valve assembly is operated in the second configuration and permits coolant fluid to circulate through the engine and the radiator.

It is to be understood that the cooling circuit may be operated in the first mode when the engine is first started from cold, whilst the cooling circuit may be operated in the second mode when the engine has warmed and cooling of the coolant fluid by circulation through the radiator is important.

The means for receiving gas from the cooling circuit may comprise a degas tank in fluid communication with the radiator, the cooling circuit being arranged to allow at least a portion of coolant fluid to flow from the radiator through the degas tank to the valve assembly.

It is to be understood that the cooling circuit may permit flow of coolant fluid from the radiator through the degas tank to an inlet port of the flow control valve that is in addition to the first and second inlet ports, or to an inlet port provided in a conduit that couples the radiator to the second inlet port of the control valve.

Embodiments of the present invention have the advantage that, because in the first mode of operation coolant fluid is not permitted to flow through the radiator or degas tank, the coolant fluid may be permitted to warm, from cold, more quickly than in known engine cooling circuit coolant fluid circuits in which coolant fluid is permitted to circulate through the degas tank even when coolant fluid is prevented from flowing through the radiator.

In the first configuration the flow diverter portion may direct fluid flowing into the valve from a coolant fluid outlet of the engine to flow along a first flow path through the valve and out from the valve to a coolant fluid inlet of the engine, and in the second configuration the flow diverter portion may direct coolant fluid flowing into the valve from the coolant fluid outlet of the engine to flow along a second flow path through the valve and out from the valve to the radiator and direct coolant fluid flowing into the valve from the radiator to flow through the valve along a third flow path and out from the valve to the coolant fluid inlet of the engine.

The valve assembly may be provided with a degas tank coolant fluid inlet that is coupled to the degas tank by means of a degas tank inlet conduit, the degas tank coolant fluid inlet being provided in an upper region of the valve assembly. When the circuit is operated in the first mode of operation, gas bubbles entrained in coolant fluid that has followed a leak path past the flow diverter portion are able to rise through the degas tank coolant fluid inlet to the degas tank.

It is to be understood that, in some embodiments, gas bubbles following the leak path may collect in an upper region of the valve assembly. When a sufficiently large volume has collected, gas may be able to rise through the degas tank coolant fluid inlet to the degas 25 tank.

The control means may comprise a controller, the controller being configured to cause the flow diverter portion to assume a selected one of the first and second configurations in dependence on a temperature of the engine or coolant fluid.

In a further aspect of the invention for which protection is sought there is provided a method of cooling an engine. The method comprises causing a flow of coolant fluid through the engine and a cooling circuit. The cooling circuit has means for coupling a coolant fluid inlet portion and a coolant fluid outlet portion of the circuit to a coolant fluid outlet and inlet, respectively, of the engine, a radiator for cooling coolant fluid, the radiator having a coolant fluid inlet and a coolant fluid outlet, a flow control valve for controlling flow of coolant fluid in the cooling circuit, and a cooling circuit degas tank. The method comprises controlling the valve to cause circulation of coolant fluid in a selected one of a first mode of operation in which the flow control valve permits coolant fluid to circulate through the engine whilst substantially preventing coolant fluid flow through the radiator and the degas tank, or a second mode of operation in which the flow control valve permits coolant fluid to circulate through the engine, the radiator and the degas tank.

In a further aspect of the invention for which protection is sought there is provided a control system comprising at least one electronic processor and at least one non-transitory computer readable medium comprising computer readable instructions that, when executed by the processor, cause performance of the method according to the above described aspect of the invention.

In a further aspect of the invention for which protection is sought there is provided a vehicle comprising: a valve assembly, an engine cooling circuit, or a control system according to the above described aspects of the invention.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

For the avoidance of doubt, it is to be understood that features described with respect to one aspect of the invention may be included within any other aspect of the invention, alone or in appropriate combination with one or more other features.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: FIGURE 1 is a schematic illustration of a vehicle according to an embodiment of the present invention; FIGURE 2 is a schematic illustration of an engine cooling circuit of the vehicle of the embodiment of FIG. 1 with a coolant fluid flow control valve in a first position whereby fluid flows substantially only through the engine and not through a radiator or degasification (degas) tank; FIGURE 3 is a schematic illustration of an engine cooling circuit of the vehicle of the embodiment of FIG. 1 with the coolant fluid flow control valve in a second position whereby coolant fluid flows through the engine, radiator and degas tank; and FIGURE 4 is a schematic illustration of an engine cooling circuit of the vehicle of the embodiment of FIG. 1 with the coolant fluid flow control valve in a first intermediate position between the first and second positions.

DETAILED DESCRIPTION

FIG. 1 shows a vehicle 100 according to an embodiment of the present invention. The vehicle 100 has an internal combustion engine 110 cooled by means of a cooling circuit 105.

FIG. 2 shows the cooling circuit 105 of the vehicle 100 of FIG. 1. An engine-driven fluid pump 117 is provided for pumping coolant fluid (or 'coolant') when the engine 110 is running. The pump 117 draws coolant through an inlet 117IN of the pump and forces the coolant through a coolant inlet 110IN of the engine 110.

A coolant outlet 110OUT of the engine 110 is coupled by means of a T-connector to an engine outlet coolant conduit 152 and to a cabin heater coolant inlet conduit 132. The engine outlet conduit 152 is in turn coupled to an engine outlet coolant inlet 142 of a coolant flow control valve unit (or 'assembly') 140. The cabin heater coolant inlet conduit 132 supplies coolant to a cabin heater 130, a coolant outlet of the cabin heater 130 being coupled by means of a cabin heater coolant outlet conduit 134 to the engine outlet coolant conduit 152 at a location proximate the engine outlet coolant inlet 142 of the coolant flow control valve unit 140.

The coolant flow control valve unit 140 has an engine inlet coolant outlet 144 that is coupled to engine-driven fluid pump 117 by means of engine inlet coolant conduit 154.

The coolant flow control valve unit 140 also has a radiator inlet coolant outlet 146 that is coupled to a coolant inlet of the radiator 120 by means of a radiator coolant inlet conduit 156. In addition, the coolant flow control valve unit 140 has a radiator coolant outlet inlet 148 that is coupled to a coolant outlet of the radiator 120 by means of a radiator coolant outlet conduit 158.

The coolant flow control valve unit 140 comprises a substantially hollow housing or body 140H in which is provided a rotatable flow diverter (or 'diverting') portion 140D. The flow diverter portion 140D may also be described as a baffle portion. In the embodiment of FIG. 2 the diverter portion 140D is rotatable about an axle 140P through an angle of substantially 90 degrees between first and second rotational positions. In the embodiment of FIG. 2 the diverter portion 140D is substantially symmetrical about the axle 140P although this is not an essential feature of all embodiments.

In the embodiment of FIG. 2 the coolant flow control valve also has a degasification (or 'degas') tank coolant outlet 149 that permits coolant flow via a degas tank outlet conduit 172 from the degas tank 170 to the valve unit 140. Pockets of gas forming in the upper region of the valve unit 140 may rise within the conduit 172 to the degas tank 170. A second degas tank outlet conduit 174 couples a further coolant outlet of the degas tank 170 to an inlet formed in the radiator coolant outlet conduit 158 that is provided proximate the radiator outlet inlet 146 of the flow control valve unit 140. A T-piece may be inserted in the outlet conduit 158 in order to achieve this connection in some embodiments.

The degas tank 170 has a gas vent 170V arranged to allow gas entrained in the flow of coolant into the tank 170 to be released from the tank 170 to atmosphere. The purpose of the degas tank 170 is to allow venting of gas bubbles that form in the cooling circuit 105. It is to be understood that the various cross-sectional areas for fluid flow through the components associated with the degas tank 170 such as the inlet and outlet conduits 172, 174 are sized so as to permit only a relatively low flow rate of coolant therethrough relative to the flow rate of coolant through the radiator 120.

In some alternative embodiments only one of the two outlet conduits 172, 174 is provided, such as only the second outlet conduit 174 and not the first outlet conduit 172. Alternatively, only the first outlet conduit 172 may be provided and not the second outlet conduit 174.

The degas tank 170 is also coupled to a top portion of the radiator 120 by means of a radiator degas outlet conduit 176. This conduit 176 permits gas, trapped in the coolant flowing through the radiator 120, to flow to the degas tank where it may be vented to atmosphere via the gas vent 170V. It is to be understood that a flow of coolant from the radiator 120 to the degas tank 170 will be established, gas trapped in the radiator 120 becoming entrained in this flow of coolant to the degas tank 170.

With the diverter portion 140D of the control valve unit 140 in the first position, illustrated in FIG. 2, the diverter portion 140D directs coolant entering the control valve unit 140 through the engine coolant outlet inlet 142 to flow out from the control valve unit 140 through engine coolant inlet outlet 144 of the valve unit 140. Flow of coolant through the valve unit 140 to the radiator inlet outlet 146 is substantially prevented.

Thus it is to be understood that, with the diverter portion 140D in the first position, the control valve unit 140 causes recirculation of coolant through the engine 110 without passing through the radiator 120, permitting the coolant and in turn the engine 110 to warm relatively rapidly to the required operating temperature range.

With the diverter portion 140D in the second position, illustrated in FIG. 3, the diverter portion 140D directs coolant entering the control valve unit 140 through the engine coolant outlet inlet 142 to flow out from the control valve unit 140 through radiator inlet outlet 146. Flow of coolant directly to the engine coolant inlet outlet 144 of the control valve unit 140 is therefore substantially prevented.

Similarly, coolant flowing into the control valve unit 140 through the radiator coolant outlet inlet 148 is caused to flow out from the control valve unit 140 through the engine coolant inlet outlet 144. Thus, with the diverter portion 140D of the valve unit 140 in the second position, the circuit 105 causes circulation of coolant from the engine 110 to the radiator 120 via the valve unit 140 and, simultaneously, back from the radiator 120 to the engine 110 again via the control valve unit 140.

As noted above, the control valve unit 140 has a degas tank coolant inlet 149 that permits coolant flow from the degas tank 170. The degas tank coolant inlet 149 is provided in an upper region of the housing 140H of the control valve unit 140 at a location such that, with the diverter portion 140D of the control valve unit 140 in the first position as shown in FIG. 2, the inlet 149 is on an opposite side of the diverter portion 140D to the flowpath (first flowpath Fl, FIG. 2) of coolant from the engine coolant outlet inlet 142 to the engine coolant inlet outlet 144. Thus, coolant flowing into the control valve unit 140 through the engine coolant outlet inlet 142 is substantially prevented from flowing to the degas tank 170.

In some embodiments, the valve unit 140 is not provided with a degas tank coolant inlet 149. Rather, coolant flowing out from the degas tank 170 flows into the radiator coolant outlet conduit 158 via degas outlet conduit 174 as described above.

Thus it can be seen that the present embodiment has the feature that recirculation of coolant through the engine 110 with the diverter portion 140D of the control valve unit 140 in the first position does not permit circulation of coolant through the degas tank 170. This has the advantage that the time taken for coolant (and therefore the engine) to warm to a desired operating temperature range may be reduced relative to known cooling systems or circuits in which circulation of coolant through a degas tank occurs even when flow through a radiator is substantially prevented.

However, it is to be understood that, in the present embodiment, when the diverter portion 140D is in the first position, a coolant leak path past the diverter portion 140D exists, as a result of manufacturing tolerances of the valve unit 140, such that a relatively small amount of coolant flowing through the engine coolant outlet inlet 142 On the present embodiment, about 1% of flow) leaks beyond the diverter portion 140D. In the embodiment of FIG. 2 coolant leaks via a gap 140DG between the diverter portion 140D and housing 140H of the control valve unit 140. Coolant that leaks in this manner, being warmer than coolant with which it comes into contact on the opposite side of the diverter portion 140D to the first flow path Fl, tends to pool within the upper volume 140U of the control valve unit 140 on this (opposite) side of the diverter portion 140D to flow path Fl. The coolant "leaking' in this manner thus tends to follow flow path F2 illustrated schematically in FIG. 2.

The degas tank inlet 149 of the control valve unit 140 is located in a wall of the housing 140H of the control valve unit 140 in an upper region thereof on the side of the diverter portion 140D opposite that over which coolant flows along the first flow path, when the diverter portion 140D is in the first position. The inlet 149 is located such that pockets of gas pooling in the upper volume 140U of the control valve unit 140 are able to pass out from the control valve unit 140 through the degas tank inlet 149 and rise to the degas tank 170 itself where the gas may be vented.

The position of the diverter portion 140D of the control valve unit 140 is controlled by means of an electronic controller 105C. The control valve unit 140 is provided with an electric motor 140M that is powered by the controller 105C and arranged to cause the diverter portion 140D to be rotated about axis 140P from the first position to the second position as required. The controller 105C receives a signal from a temperature sensor 110T that is coupled to the engine 110 and arranged to output a signal indicative of the temperature of coolant flowing through the engine 110. In some embodiments the temperature sensor 110T may be provided at another location, such as at the coolant outlet 1100UT of the engine 110 or within the coolant outlet conduit 152 of the engine 110.

The controller 105C is configured to cause the diverter portion 140D to assume the first position whilst the signal from temperature sensor 110T indicates the coolant temperature is below a first predetermined temperature value which may be any suitable value such as 80 Celsius, 90 Celsius, 100 Celsius or any other suitable temperature. When the temperature exceeds this first predetermined temperature, the controller 105C is configured to cause the diverter portion 140D to rotate towards the second position (shown in FIG. 3) in a predetermined number of stages. In the present embodiment the controller 105C is configured to cause the diverter portion 140D to rotate towards the second position in two stages.

Firstly, the controller 105C causes the diverter portion 140D to rotate from the first position to a first intermediate position between the first and second positions. In the present embodiment the first intermediate position is an angular distance of substantially 45 degrees from the first position and the second position is an angular distance of substantially 90 degrees from the first position although other angles may be useful in some embodiments.

In the first intermediate position, illustrated schematically in FIG. 4, the diverter portion 140D causes coolant flowing into the valve unit 140 through the engine outlet inlet 142 of the valve unit 140 to be split between the first and second flow paths Fl, F2 shown in FIG. 2 and FIG. 4, but with a greater proportion of coolant flowing along the second flow path F2 (approximately 2% of flow) compared with that with the diverter portion 140D in the first position. Coolant again pools in the upper volume 140U of the valve unit 140, and the circuit is configured such that at least some coolant begins to flow through the radiator 120 along flowpaths F3 and F4 as shown in FIG. 4. Thus, relatively cold coolant flowing along flowpath F4 from the radiator 120 mixes with warmer coolant flowing through the valve unit 140 along flowpath Fl, causing dilution (and cooling) of the warmer coolant.

It is to be understood that the controller 105C causes the diverter portion 140D to rotate towards the second position in two stages rather than a single stage (i.e. rather than a single stage from the first position directly to the second position) so as to reduce the risk of adverse thermal shock to the engine 100 that may be caused when relatively cold, undiluted coolant within the radiator 120 flows into the engine 110 as the engine is warming. By rotating first to the first intermediate position, the valve unit 140 causes at least some warm coolant from the coolant outlet of the engine 100 that flows through the valve unit 140 along the second flow path to flow through the radiator 100 along the third flow path F3 and relatively cold coolant within the radiator 120 to flow along the fourth flow path F4 (FIG. 4).

Coolant from the radiator 120 flowing along the fourth flow path mixes with some of the warmed coolant from the engine 100 flowing along the second flowpath F2 before flowing through the engine 110. The circuit 105 thus begins to cause warming of coolant within the radiator 120. This reduces thermal shock to the engine 110 when the diverter portion 140D of the valve unit 140 finally assumes the second position and substantially all the warmed coolant from the engine 110 is caused to flow through the radiator 120.

With the diverter portion 140D in the first intermediate position (FIG. 4), the controller 105C continues to monitor coolant temperature by means of the temperature sensor 110T. If the coolant temperature subsequently exceeds a second predetermined temperature that is higher than the first, the controller 105C causes the diverter portion 140D to rotate to the second position, an angle of approximately 90 degrees from the first position. The second predetermined temperature may be a predetermined number of degrees higher than the first predetermined temperature, such as 5 Celsius, 10 Celsius or any other suitable number of Celsius higher.

It is to be understood that, in one embodiment, the first and second predetermined temperatures are 80 Celsius and 90 Celsius, respectively. Other values of the first and second predetermined temperatures may be useful in some embodiments.

It is to be understood that the diverter portion 140D may be caused to return to the first intermediate position from the second position if the temperature of the engine 100 falls from a temperature at or above the second predetermined temperature to a temperature below the second predetermined temperature. In order to prevent mode chattering (i.e. rapid switching of the position of the diverter portion 140D between positions) the controller 105C may be configured to cause the diverter portion 140D to switch from the second position to the first intermediate position if the coolant temperature falls a predetermined threshold amount below the second intermediate temperature, where the threshold amount may be any suitable value such as 2 Celsius, 3 Celsius or any other suitable value. Similarly, the controller may be configured to cause the diverter portion 140D to switch from the first intermediate position to the first position if the coolant temperature falls a predetermined threshold amount below the first intermediate temperature where the threshold amount may again be any suitable value such as 2 Celsius, 3 Celsius or any other suitable value.

In some embodiments, the control valve unit 140 may be actuated by means of a thermally reactive mechanical actuator such as a wax thermostat element or bimetallic strip. Other arrangements may be useful in some embodiments.

Embodiments of the present invention have the advantage that, because the degas tank 170 is not provided in the flow path of coolant when the coolant is relatively cold, the amount of time taken for the engine 100 to achieve a desired operating temperature (which is typically a temperature above ambient temperature) may be reduced. This can have one or more of the advantages of reducing unwanted vehicle emissions, reducing engine component wear and reducing the time taken for cabin warming where a cabin heater is provided that is heated at least in part by means of engine coolant.

For purposes of this disclosure, it is to be understood that the controller(s) described herein can each comprise a control unit or computational device having one or more electronic processors. A vehicle and/or a system thereof may comprise a single control unit or electronic controller or alternatively different functions of the controller(s) may be embodied in, or hosted in, different control units or controllers. A set of instructions could be provided which, when executed, cause said controller(s) or control unit(s) to implement the control techniques described herein (including the described method(s)). The set of instructions may be embedded in one or more electronic processors, or alternatively, the set of instructions could be provided as software to be executed by one or more electronic processor(s). For example, a first controller may be implemented in software run on one or more electronic processors, and one or more other controllers may also be implemented in software run on or more electronic processors, optionally the same one or more processors as the first controller. It will be appreciated, however, that other arrangements are also useful, and therefore, the present disclosure is not intended to be limited to any particular arrangement. In any event, the set of instructions described above may be embedded in a computer-readable storage medium (e.g., a non-transitory computer-readable storage medium) that may comprise any mechanism for storing information in a form readable by a machine or electronic processors/computational device, including, without limitation: a magnetic storage medium (e.g., floppy diskette); optical storage medium (e.g.. CD-ROM); magneto optical storage medium; read only memory (ROM); random access memory (RAM); erasable programmable memory (e.g., EPROM ad EEPROM); flash memory; or electrical or other types of medium for storing such information/instructions.

Throughout the description and claims of this specification, the words "comprise" and "contain" and variations of the words, for example "comprising" and "comprises", means "including but not limited to", and is not intended to (and does not) exclude other moieties, additives, components, integers or steps.

Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith.

Claims

CLAIMS1. A flow control valve assembly for an engine cooling circuit, the assembly comprising a first inlet port for receiving a flow of coolant fluid from an engine, a second inlet port for receiving a flow of coolant fluid from a radiator, a first outlet port for delivering a flow of coolant fluid to the engine, a second outlet port for delivering a flow of coolant fluid to the radiator and a flow diverter portion arranged to direct a flow of coolant fluid from the first inlet port to the first outlet port in a first configuration and to direct a flow of coolant fluid from the first inlet port to the second outlet port in a second configuration and to direct a flow of coolant fluid from the second inlet port to the first outlet port in the second configuration, wherein, in use, the first outlet port is located above the first inlet port and the second inlet port is located above the first inlet port.
2. An engine cooling circuit comprising: a valve assembly according to claim 1 for controlling flow of coolant fluid in the cooling circuit; a radiator for cooling coolant fluid, the radiator having a coolant fluid inlet and a coolant fluid outlet coupled to the second outlet and second inlet ports, respectively, of the valve assembly; and means for receiving gas from the cooling circuit, wherein the cooling circuit comprises control means configured to allow circulation of coolant fluid in a selected one of a first mode of operation in which the valve assembly is operated in the first configuration and permits coolant fluid to circulate through the engine whilst substantially preventing coolant fluid flow through the radiator, or a second mode of operation in which the valve assembly is operated in the second configuration and permits coolant fluid to circulate through the engine and the radiator.
3. A cooling circuit according to claim 2 wherein the means for receiving gas from the cooling circuit comprises a degas tank in fluid communication with the radiator, the cooling circuit being arranged to allow at least a portion of coolant fluid to flow from the radiator through the degas tank to the valve assembly.
4. A cooling circuit according to claim 2 or claim 3 wherein when in the first configuration the flow diverter portion directs fluid flowing into the valve from a coolant fluid outlet of the engine to flow along a first flow path through the valve and out from the valve to a coolant fluid inlet of the engine and in the second configuration the flow diverter portion directs coolant fluid flowing into the valve from the coolant fluid outlet of the engine to flow along a second flow path through the valve and out from the valve to the radiator and directs coolant fluid flowing into the valve from the radiator to flow through the valve along a third flow path and out from the valve to the coolant fluid inlet of the engine.
5. A cooling circuit according to 3 or claim 4 as dependent on claim 3 wherein the valve assembly is provided with a degas tank coolant fluid inlet that is coupled to the degas tank by means of a degas tank inlet conduit, the degas tank coolant fluid inlet being provided in an upper region of the valve assembly, wherein, when the circuit is operated in the first mode of operation, gas bubbles entrained in coolant fluid that has followed a leak path past the flow diverter portion are able to rise through the degas tank coolant fluid inlet to the degas tank.
6. A cooling circuit according to any one of claims 2 to 5, wherein the control means comprises a controller, the controller being configured to cause the flow diverter portion to assume a selected one of the first and second configurations in dependence on a temperature of the engine or coolant fluid.
7. A method of cooling an engine comprising: causing a flow of coolant fluid through the engine and a cooling circuit, the cooling circuit having: means for coupling a coolant fluid inlet portion and a coolant fluid outlet portion of the circuit to a coolant fluid outlet and inlet, respectively, of the engine; a radiator for cooling coolant fluid, the radiator having a coolant fluid inlet and a coolant fluid outlet; a flow control valve for controlling flow of coolant fluid in the cooling circuit; and a cooling circuit degas tank; the method comprising controlling the valve to cause circulation of coolant fluid in a selected one of a first mode of operation in which the flow control valve permits coolant fluid to circulate through the engine whilst substantially preventing coolant fluid flow through the radiator and the degas tank, or a second mode of operation in which the flow control valve permits coolant fluid to circulate through the engine, the radiator and the degas tank.
8. A control system comprising: at least one electronic processor; and at least one non-transitory computer readable medium comprising computer readable instructions that, when executed by the processor, cause performance of the method of claim 7.
9. A vehicle comprising: a valve assembly according to claim 1, a circuit according to any of claims 2 to 6, or a control system according to claim 8.