US20100218916A1

US20100218916A1 - Plug-in hybrid electric vehicle secondary cooling system

Info

Publication number: US20100218916A1
Application number: US12/394,689
Authority: US
Inventors: Kenneth James Miller; Brandon R. Masterson; Daniel Scott Colvin
Original assignee: Ford Global Technologies LLC
Current assignee: Ford Global Technologies LLC
Priority date: 2009-02-27
Filing date: 2009-02-27
Publication date: 2010-09-02
Also published as: DE102010000342A1; JP2010202184A; CN101817302A

Abstract

A system for utilizing heat generated by a component of a plug-in hybrid electric vehicle includes a first component having a first coolant system extending therethrough. The first coolant circulation system includes a first radiator. The system also includes a second component having a second coolant circulation system extending therethrough. The second coolant circulation system is in fluid communication with the first coolant circulation system. The first coolant system is configured is to selectively direct heated coolant from the first component to the second component.

Description

BACKGROUND

1. Field
Embodiments of the present invention relate to the utilization of heat generated by a first component in a plug-in hybrid electric vehicle to raise the temperature of a second component in a plug-in hybrid electric vehicle.
2. Background Art
Plug-in hybrid electric vehicles are configured to run for a predetermined distance or period of time primarily using energy stored in the vehicle's rechargeable battery. Plug-in hybrid electric vehicles include an internal combustion engine, an electric motor, and a rechargeable battery.
Plug-in hybrid electric vehicles are commonly configured in one of two distinct configurations. In a first configuration, the internal combustion engine and the electric motor are each configured to deliver torque to the drive wheels of the vehicle. This is known as a blended or parallel configuration. In a second configuration, known as a series configuration, only the electric motor delivers torque to the drive wheels of the vehicle. In a series configuration, the internal combustion engine is used exclusively to recharge the rechargeable battery or to deliver energy to the electric motor.
Both types of plug-in hybrid electric vehicles operate during an initial period of time using primarily the energy stored in the rechargeable battery to run the electric motor and deliver torque to the vehicle's drive wheels. During such periods of battery powered operation, the electric motor may lack sufficient power to meet driver demands. For instance, when accelerating on an on ramp to a freeway, the driver may demand more power from the vehicle's propulsion system than can be supplied by the electric motor powered by the battery alone. During these brief periods of high power demand, the internal combustion engine may temporarily turn on to provide either additional torque to the drive wheels or additional power to the electric motor to fulfill the demand for additional power. Once the need for increased power abates, the internal combustion engine will turn off and will remain off until either the next demand for increased power or until the rechargeable battery is drained to the point where continuous operation of the internal combustion engine is needed.
During battery-only vehicle operations, because the internal combustion engine is operated for only brief, intermittent periods of time, the internal combustion engine remains well below its optimal operating temperature which, depending upon the engine, can vary between 180° and 220° F. or even higher. When an internal combustion engine operates at a temperature below its optimal or desirable operating temperature, the internal combustion engine is less efficient and consumes more fuel. Hence, operation of the internal combustion engine below its optimal operating temperature can have an adverse impact on the plug-in hybrid electric vehicle's fuel economy. Embodiments of the invention disclosed herein address this and other problems.

SUMMARY

Various embodiments of a system for utilizing heat generated by a component of a plug-in hybrid electric vehicle are disclosed herein. In a first embodiment, the system comprises a first component having a first coolant circulation system extending therethrough. The first coolant circulation system includes a first radiator. The system further comprises a second component having a second cooling circulation system extending therethrough. The second coolant circulation system is in fluid communication with the first coolant circulation system. In this first embodiment, the first coolant circulation system is configured to selectively direct heated coolant from the first component to the second component.
In an implementation of the first embodiment, the first coolant system is further configured to selectively prevent the heated coolant from flowing between the first component and the first radiator. In a variation of this implementation, the first coolant system further comprises a first valve that is configured to selectively direct the flow of heated coolant from the first component to one of the second component and the first radiator. In another variation, the first coolant system is further configured to permit the heated coolant to flow from the first component to the first radiator and to prevent the heated coolant from flowing to the second component when the second component reaches a predetermined temperature.
In a second embodiment, the system comprises an electric component having a first coolant circulation system extending therethrough. The first coolant circulation system includes a first radiator. The system further comprises an internal combustion engine (ICE) having a second coolant circulation system extending therethrough. The second coolant circulation system is in fluid communication with the first coolant circulation system. In this second embodiment, the first coolant circulation system is configured to selectively direct heated coolant from the electric component to the ICE.
In an implementation of the second embodiment, the electric component comprises an ISC.
In another implementation of the second embodiment, the first coolant system is further configured to selectively prevent the heated coolant from flowing between the electric component and the first radiator. In a variation of this implementation, the first coolant system further comprises a first valve that is configured to selectively direct the flow of the heated coolant from the electric component to one of the ICE and the first radiator. In a further variation, the second coolant circulation system further comprises a second radiator and a second valve configured to selectively direct the flow of coolant from the internal combustion engine to one of the electric component and the second radiator.
In a further variation of this implementation, the second valve is further configured to direct the flow of coolant from the internal combustion engine to the electric component when the first valve directs the heated coolant from the electric component to the ICE. In a further variation, the second valve is further configured to direct the flow of coolant from the internal combustion engine to the second radiator when the first valve directs the heated coolant from the electric component to the first radiator. In another variation, the first valve is further configured to direct the heated coolant from the electric component to the ICE when the ICE is not operating. The first valve is further configured to direct the heated coolant from the electric component to the ICE when the ICE is operating.
In a third embodiment, the system comprises an electric component having a first coolant circulation system extending therethrough. The first coolant circulation system includes a first radiator. The system further comprises a heater core having a second coolant circulation system extending therethrough. The second coolant circulation system is in fluid communication with the first coolant circulation system. In this third embodiment, the first coolant circulation system is configured to selectively direct heated coolant from the first component to the heater core.
In an implementation of the third embodiment, the electric component comprises an ISC.
In another implementation of the third embodiment, the first coolant system is further configured to selectively prevent the heated coolant from flowing between the electric component and the first radiator.
In another implementation of the third embodiment, the system further comprises an internal combustion engine having the second coolant circulation system extending therethrough. The second coolant circulation system further comprises a second radiator. In a variation of this implementation, the first coolant system further comprises a first valve that is configured to selectively direct the flow of the heated coolant from the electric component to one of the second coolant circulation system and the first radiator. In a further variation of this implementation, the second coolant system further comprises a second valve that is configured to selectively direct the flow of coolant from the internal combustion engine to one of the second radiator and the electric component. In a still further variation, the heater core is positioned downstream of the internal combustion engine such that when the second valve directs the flow of coolant from the internal combustion engine to the electric component, the coolant passes through the core. In yet a further variation, the electric component comprises an ISC.

BRIEF DESCRIPTION OF THE DRAWINGS

The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and in which:

FIG. 1A is a schematic view illustrating a system for utilizing heat generated by an inverter system controller (ISC) to warm an engine block of an internal combustion engine (ICE) in a plug-in hybrid electric vehicle;

FIG. 1B is a schematic view illustrating the system of FIG. 1A with heated coolant flowing from the ISC to the ICE and then flowing back to the ISC;

FIG. 2A is a schematic view illustrating an alternate embodiment of the system of FIG. 1 wherein heated coolant from the ISC is used to heat a heater core;

FIG. 2B is a schematic view illustrating the system of FIG. 2A with heated coolant flowing from the ISC to the heater core and then back to the ISC;

FIG. 3A is a schematic view illustrating another embodiment of the system of FIGS. 1A and B wherein heated coolant from the ISC heats both the ICE and the heater core; and

FIG. 3B is a schematic view illustrating the system of FIG. 3A with heated coolant flowing from the ISC through both the ICE and the heater core and then back to the ISC.

DETAILED DESCRIPTION OF THE EMBODIMENT(S)

Detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily drawn to scale, some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for the claims and/or as a representative basis for teaching one skilled in the art to variously employ the present invention.
Plug-in hybrid electric vehicles include one or more electric motors and one or more internal combustion engines. A rechargeable battery supplies electric power to the electric motor. An inverter system controller (ISC) converts direct current from the rechargeable battery to alternating current for use by the electric motor. During operations, the temperature of the ISC rises. If not cooled, the ISC will heat to a temperature beyond its optimal operating temperature and may even overheat. Similarly, the temperature of the internal combustion engine (ICE) will also rise during normal operations and, if not properly cooled, will exceed an optimal operating temperature for the ICE. To keep the ISC cool, the ISC has a first coolant circulation system extending through the ISC. A coolant having a temperature lower than that of the ISC enters the ISC, circulates through the ISC causing the fluid to heat up and the ISC to cool down. The heated fluid is then directed to a first radiator where the heated fluid is cooled and re-circulated to the ISC.
Similarly, a second coolant circulation system is used to cool the ICE. A fluid having a temperature less than that of the ICE enters the ICE, circulates therethrough and causes the fluid to heat up and the ICE to cool down. The heated fluid exits the ICE and is directed to a second radiator where the coolant is cooled down and re-circulated back to the ICE.
A plug-in hybrid electric vehicle is configured to operate solely on battery power for a predefined distance or period of time. During battery-only operations, the internal combustion engine is not operated and an electric motor(s) propels the vehicle. During such periods, the rechargeable battery supplies power to the electric motor for operations. At times where driver or other vehicle demands for power exceed the power capability of the rechargeable battery power alone, the ICE will briefly turn on and operate to assist the electric motors in propelling the vehicle. During such periods of brief, intermittent operation, the ICE does not have sufficient time to warm to its optimal operating temperature (approximately 200° F.). Accordingly, during such intermittent operations, the ICE operates below its peak efficiency which can cause an elevated rate of fuel consumption.
In accordance with the teachings of the present invention, the first coolant circulation system is configured to route the heated coolant from the ISC to the second coolant circulation system where the heated coolant passes through the ICE. The heated coolant is at a temperature higher than the ICE and, as the heated coolant passes through the ICE, the ICE acts as a radiator taking heat out of the fluid. This causes the ICE to heat up. The second coolant circulation system is configured to direct the cooled coolant exiting the ICE back to the first coolant circulation system where it is routed through the ISC and the cycle begins again. In this manner, heat is transferred from the ISC to the ICE which permits the ICE to maintain an elevated temperature above ambient so that the ICE may operate at a higher efficiency level during the brief, intermittent periods of operation.
The teachings of the present invention are not limited to using heated coolant from the ISC to heat the ICE. Rather, other heat sources and heat targets may be utilized as well. For instance, in another embodiment, it may be desirable to route the heated coolant from the ISC through a vehicle's heater core which is used to supply heat to a vehicle's heating and ventilation system. In this manner, the heater core, which typically relies on heated coolant routed from the ICE, may use heated coolant from the ISC to supply heat to the vehicle's HVAC system during electric only operations of the plug-in hybrid electric vehicle. In other embodiments, the heated coolant from the ISC may be routed to pass through both the ICE and the heater core. In still other embodiment, one or more of the electric motors may supply the heated coolant instead of the ISC. A greater understanding of the embodiments of the invention described herein may be obtained through a review of the figures accompanying this disclosure together with a review of the detailed description that follows.
With respect to FIG. 1A, a system 10 for utilizing the heat generated by a component of a plug-in hybrid electric vehicle is schematically represented. System 10 may be employed in any plug-in hybrid electric vehicle including those configured to operate in both a blended and a series manner. System 10 includes a first component 12 which generates heat during operations. In FIG. 1A, first component 12 is depicted as an ISC. It should be understood, however, that any heat generating component may serve as first component 12 of system 10. A first coolant circulation system 14 circulates a coolant through first component 12. First coolant circulation system 14 includes a first radiator 16, conduits 18 and 20, first radiator 16, conduits 22 and 24, ISC 12, and a coolant pathway internal to ISC 12 (not shown). First coolant circulation system 14 also includes a first valve 26 which is configured to route heated coolant exiting from conduit 24 towards one of two distinct paths. As illustrated in FIG. 1A, first valve 26 is positioned to direct heated coolant from conduit 24 to conduit 18.
System 10 further includes a second component 28. In the embodiment illustrated in FIG. 1A, second component 28 is an ICE. It should be understood that second component 28 may be any other component of the plug-in hybrid electric vehicle utilizing system 10 which it would be desirable to heat.
A second coolant circulation system 30 is configured to cool second component 28 during operations of second component 28. Second coolant circulation system 30 comprises a second radiator 32 configured to cool heated coolant as the heated coolant passes through second radiator 32. Second coolant circulation system 30 also includes conduits 34 and 36. Second coolant circulation system 30 also includes conduits 38 and 40. Second coolant circulation system 30 also includes a pathway (not shown) through second component 28 configured to carry coolant throughout second component 28 for the purpose of cooling component 28.
In the embodiment illustrated in FIG. 1A, second coolant circulation system 30 further comprises a second valve 42 configured to direct heated coolant from conduit 40 towards one of two distinct paths. In the embodiment illustrated in FIG. 1A, second valve 42 is positioned to direct heated coolant to conduit 34 towards second radiator 32.
First coolant circulation system 14 and second coolant circulation system 30 are linked in fluid communication with one another through linking conduit 44 and linking conduit 46. Linking conduit 44 is connected to first valve 26 and linking conduit 46 is connected to second valve 42. When first valve 26 is moved from the position illustrated in FIG. 1A to a linking position, first valve 26 will link conduit 24 with linking conduit 44 and thus allow heated coolant from first component 12 to flow along linking conduit 44 into conduit 38 and from there to second component 28. When second valve 42 is moved from the position illustrated in FIG. 1A, to a linking position connecting conduit 40 with linking conduit 46, cooled coolant exiting second component 28 may be directed along linking conduit 46 to conduit 22 and on to first component 12 where the coolant is heated.
With respect to FIG. 1B, the system 10 of FIG. 1A is illustrated with first and second valve 26, 42 moved into the linking position. With first and second valve 26, 42 in the linking position, a third coolant circulation system 48 is formed. In third coolant circulation system 48, coolant enters first component 12 where it is heated and then exits along conduit 24, passes through first valve 26 where the heated coolant is directed along linking conduit 44 into conduit 38 and then into second component 28. The coolant cools down as it delivers heat to second component 28. In this manner, second component 28 serves as a radiator to cool the coolant passing through first component 12. After passing through second component 28, the cooled coolant travels along conduit 40 into second valve 42 where the coolant is then directed along linking conduit 46 to conduit 22 where the coolant is then routed back through first component 12 to begin another heating and cooling cycle. With first and second valves 26, 42 in the linking position, first and second radiators 16, 32 are bypassed.
First and second valves 26, 42 may be connected to a controller (not shown) which can selectively move first and second valve 26, 42 from their respective independent operation positions to their respective linking positions. The controller may be a microprocessor, computer or mechanical device or any other mechanism suitable for controlling the positions of first and second valve 26, 42 and the timing of their respective movement between the independent and linked position. The controller may be configured to control first and second valves 26, 42 based on the temperature of ICE 28, or based on whether ICE 28 is on or off, or based on any other desirable triggering criterion. In other embodiments, additional valves may be utilized to control the path of coolant flow. The controller controlling the positioning of first and second valve 26, 42 may be configured to move first and second valves 26 and 42 to the linked position while the plug-in hybrid electric vehicle is operating in an electric only mode wherein the internal combustion engine is not operated.
Once the internal combustion engine begins to operate, it will quickly reach a temperature wherein it can no longer serve as a radiator for cooling the coolant flowing through ISC 12. In normal conventional operations, internal combustion engines are operated between approximately 180° and approximately 220° F. while conventional ISC's operate at a maximum temperature of roughly 160° F. Therefore, once the ICE kicks on at the conclusion of electric-only operations and stays on, the controller will move first and second valves 26, 42 from their respective linked positions to their independent operation positions which closes off ISC 12 from ICE 28 and permits independent operation of the first and second coolant circulation systems 14, 30. In some embodiments, ICE 28 may heat slowly and may, for some period of time, continue to serve effectively as a radiator for ISC 12. In such embodiments, the controller may not move first and second valves 26, 42 to their respective independent positions until ICE 28 reaches a predetermined temperature.
With respect to FIG. 2A an alternate embodiment of system 10, here system 10′ for utilizing heat generated by a component of a plug-in hybrid electric vehicle is illustrated. In system 10′, a third component 50, here illustrated as a heat core, serves as a radiator to cool the heated coolant exiting ISC 12. In FIG. 2A, first valve 26 is illustrated in the independent position wherein first coolant circulation system 14 cools ISC 12. System 10′ does not include a second valve 42 or a second coolant circulation system 30.
With respect to FIG. 2B, the system 10′ of FIG. 2A is illustrated with first valve 26 moved to the linking position to direct coolant from ISC 12 to heater core 50. In embodiments of plug-in hybrid electric vehicles wherein heater core 50 is not connected to a coolant system for cooling the internal combustion engine, ISC 12 may be the sole source of heat for heater core 50 and the controller controlling first valve 26 may maintain first valve 26 in the linked position until such time as the temperature of heater core 50 rises to a level where it can no longer effectively serve as a radiator for ISC 12. In such event, the controller would move first valve 26 to the independent position wherein the coolant passing through ISC 12 would be cooled by first radiator 16. When the temperature of heater core 50 falls below a predetermined temperature, the controller may return first valve 26 to the linked position to allow coolant to flow from ISC 12 to heater core 50.
With respect to FIG. 3A, a system 10″ for utilizing the heat generated by a component of a plug-in hybrid electric vehicle is illustrated. In system 10″, first coolant circulation system 14 is the same as that illustrated in FIG. 1A for system 10. In system 10″, second coolant circulation system 30 circulates coolant through ICE 28 and heater core 50. Coolant enters ICE 28 from conduit 38, passes through ICE 28, cooling ICE 28 in the process and exits ICE 28 through conduit 40 where it is directed into heater core 50. The heated coolant entering heater core 50 warms heater core 50 as it passes through heater core 50, then exits heater core 50 and travels along conduit 41 to second valve 42. With second valve 42 in the independent position, the heated coolant is directed to conduit 34 and then into second radiator 32 where it is cooled and then passes into conduit 36 and then directed into conduit 38 where it enters ICE 28 to begin another heating and cooling cycle.
The independent operation of first coolant circulation system 14 and second coolant circulation 28 may occur subsequent to an electric only operation of the plug-in hybrid electric vehicle when the internal combustion engine is operated to aid electric motors in propelling the vehicle. Prior to operation of the internal combustion engine, system 10′ operates in the manner depicted in FIG. 3B. A controller (not shown) moves first and second valves 26, 42 to their respective linked position effectively bypassing first and second radiators 16 and 32. As illustrated in FIG. 3B, coolant enters ISC 12 and circulates therethrough, cooling ISC 12 as it is heated. The coolant exits ISC 12 and enters conduit 24 where it is directed to first valve 26. First valve 26, illustrated in the linked position, directs the coolant along linking conduit 44 to conduit 38 where it is directed into ICE 28. The heated coolant passes through ICE 28, warming ICE 28 as it passes through and then exits ICE 28 in conduit 40 where it is directed into heater core 50 where the coolant is further cooled, heating heater core 50 in the process. The cooled coolant leaves heater core 50 along conduit 41 and enters second valve 42 which, when in the linked position, directs the coolant into linking conduit 46 where it is directed to conduit 22 and on into ISC 12 where a new heating and cooling cycle begins. The system 10″ illustrated in FIG. 3B may be utilized during electric-only operations of the plug-in hybrid electric vehicle when ICE 28 is not operated for any substantial length of time.
While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and various changes may be made without departing from the spirit and scope of the invention.

Claims

1. A system for a hybrid electric vehicle having an engine and an electric drive system, including an electric motor, the system comprising:

a component of the electric drive system;

a first closed-loop coolant circulation system associated with the electric drive system component and having a coolant configured to flow therethrough

a vehicle component to be heated;

a second closed-loop coolant circulation system associated with the vehicle component to be heated, the first and second coolant circulation systems being operable independently of each other, and selectively in fluid communication with each other;

such that heated coolant from the component of the electric drive system can be provided to the vehicle component to be heated; and

a radiator in fluid communication with at least one of the closed-loop coolant circulation systems for transferring heat away from the corresponding coolant.

2. The system of claim 1 wherein the first coolant circulation system is further configured to selectively prevent heated coolant from flowing between the component of the electric drive system and the radiator.

3. The system of claim 2 wherein the first coolant circulation system further comprises a first valve configured to selectively direct the flow of heated coolant from the component of the electric drive system to one of the vehicle component to be heated or the radiator.

4. The system of claim 2 wherein the first coolant circulation system is further configured to permit heated coolant to flow from the component of the electric drive system to the radiator and to prevent heated coolant from flowing to the vehicle component to be heated when the vehicle component to be heated reaches a predetermined temperature.

5. A system for utilizing heat generated by a component of a plug-in hybrid electric vehicle, the system comprising:

an electric component having a first coolant circulation system extending therethrough, the first coolant circulation system including a first radiator; and

an internal combustion engine (ICE) having a second coolant circulation system extending therethrough, the second coolant circulation system (ICE) being in fluid communication with the first coolant circulation system;

wherein the first coolant circulation system is configured to selectively direct heated coolant from the electric component to the ICE.

6. The system of claim 5 wherein the electric component comprises an ISC.

7. The system of claim 5 wherein the first coolant system is further configured to selectively prevent the heated coolant from flowing between the electric component and the first radiator.

8. The system of claim 7 wherein the first coolant system further comprises a first valve configured to selectively direct the flow of the heated coolant from the electric component to one of the ICE and the first radiator.

9. The system of claim 8 wherein the second coolant circulation system further comprises a second radiator and a second valve configured to selectively direct the flow of coolant from the internal combustion engine to one of the electric component and the second radiator.

10. The system of claim 9 wherein the second valve is further configured to direct the flow of coolant from the internal combustion engine to the electric component when the first valve directs the heated coolant from the electric component to the ICE.

11. The system of claim 10 wherein the second valve is further configured to direct the flow of coolant from the internal combustion engine to the second radiator when the first valve directs the heated coolant from the electric component to the first radiator.

12. The system of claim 10 wherein the first valve is further configured to direct the heated coolant from the electric component to the ICE when the ICE is not operating and wherein the first valve is further configured to direct the heated coolant from the electric component to the ICE when the ICE is operating.

13. A system for utilizing heat generated by a component of a plug-in hybrid electric vehicle, the system comprising:

a heater core having a second coolant circulation system extending therethrough, the second coolant circulation system being in fluid communication with the first coolant circulation system;

wherein the first coolant circulation system is configured to selectively direct heated coolant from the first component to the heater core.

14. The system of claim 13 wherein the electric component comprises an ISC.

15. The system of claim 13 wherein the first coolant system is further configured to selectively prevent the heated coolant from flowing between the electric component and the first radiator.

16. The system of claim 13 further comprising an internal combustion engine having the second coolant circulation system extending therethrough, the second coolant circulation system further comprising a second radiator.

17. The system of claim 16 wherein the first coolant system further comprises a first valve configured to selectively direct the flow of the heated coolant from the electric component to one of the second coolant circulation system and the first radiator.

18. The system of claim 17 wherein the second coolant circulation system further comprises a second valve configured to selectively direct the flow of coolant from the internal combustion engine to one of the second radiator and the electric component.

19. The system of claim 18 wherein the heater core is positioned down stream of the internal combustion engine such that when the second valve directs the flow of coolant from the internal combustion engine to the electric component, the coolant passes through the heater core.

20. The system of claim 19 wherein the electric component comprises an ISC.