U.S. patent application number 12/394689 was filed with the patent office on 2010-09-02 for plug-in hybrid electric vehicle secondary cooling system.
This patent application is currently assigned to Ford Global Technolgies, LLC. Invention is credited to Daniel Scott Colvin, Brandon R. Masterson, Kenneth James Miller.
Application Number | 20100218916 12/394689 |
Document ID | / |
Family ID | 42371857 |
Filed Date | 2010-09-02 |
United States Patent
Application |
20100218916 |
Kind Code |
A1 |
Miller; Kenneth James ; et
al. |
September 2, 2010 |
PLUG-IN HYBRID ELECTRIC VEHICLE SECONDARY COOLING SYSTEM
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.
Inventors: |
Miller; Kenneth James;
(Canton, MI) ; Masterson; Brandon R.; (Dexter,
MI) ; Colvin; Daniel Scott; (Farmington Hills,
MI) |
Correspondence
Address: |
BROOKS KUSHMAN P.C./FGTL
1000 TOWN CENTER, 22ND FLOOR
SOUTHFIELD
MI
48075-1238
US
|
Assignee: |
Ford Global Technolgies,
LLC
|
Family ID: |
42371857 |
Appl. No.: |
12/394689 |
Filed: |
February 27, 2009 |
Current U.S.
Class: |
165/104.11 |
Current CPC
Class: |
F01P 7/165 20130101;
F01P 2050/24 20130101; F01P 2060/08 20130101; B60K 2001/003
20130101; F01P 2037/02 20130101; Y02T 90/14 20130101; Y02T 10/6269
20130101; Y02T 10/62 20130101 |
Class at
Publication: |
165/104.11 |
International
Class: |
F28D 15/00 20060101
F28D015/00 |
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: an electric
component having a first coolant circulation system extending
therethrough, the first coolant circulation system including a
first radiator; and 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.
Description
BACKGROUND
[0001] 1. Field
[0002] 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.
[0003] 2. Background Art
[0004] 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.
[0005] 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.
[0006] 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.
[0007] 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.degree. and 220.degree. 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
[0008] 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.
[0009] 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.
[0010] 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.
[0011] In an implementation of the second embodiment, the electric
component comprises an ISC.
[0012] 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.
[0013] 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.
[0014] 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.
[0015] In an implementation of the third embodiment, the electric
component comprises an ISC.
[0016] 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.
[0017] 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
[0018] The description herein makes reference to the accompanying
drawings wherein like reference numerals refer to like parts
throughout the several views, and in which:
[0019] 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;
[0020] 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;
[0021] 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;
[0022] 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;
[0023] 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
[0024] 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)
[0025] 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.
[0026] 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.
[0027] 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.
[0028] 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.degree. F.). Accordingly, during
such intermittent operations, the ICE operates below its peak
efficiency which can cause an elevated rate of fuel
consumption.
[0029] 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.
[0030] 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.
[0031] 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.
[0032] 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.
[0033] 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.
[0034] 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.
[0035] 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.
[0036] 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.
[0037] 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.
[0038] 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.degree. and approximately
220.degree. F. while conventional ISC's operate at a maximum
temperature of roughly 160.degree. 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.
[0039] 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.
[0040] 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.
[0041] 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.
[0042] 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.
[0043] 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.
* * * * *