U.S. patent application number 14/099065 was filed with the patent office on 2014-07-03 for integrated waste heat recovery.
This patent application is currently assigned to GM GLOBAL TECHNOLOGY OPERATIONS LLC. The applicant listed for this patent is GM GLOBAL TECHNOLOGY OPERATIONS LLC. Invention is credited to John R. Bucknell, James D. Hendrickson.
Application Number | 20140182266 14/099065 |
Document ID | / |
Family ID | 50928599 |
Filed Date | 2014-07-03 |
United States Patent
Application |
20140182266 |
Kind Code |
A1 |
Hendrickson; James D. ; et
al. |
July 3, 2014 |
INTEGRATED WASTE HEAT RECOVERY
Abstract
A system and method of operating a waste heat recovery system
for a vehicle is provided. The system includes an
expander/compressor portion mechanically linked to wheels of the
vehicle, the expander/compressor portion including an inlet valve
and an exhaust valve. A combustion engine is provided having an
exhaust portion. A working fluid path is thermally coupled between
the combustion engine and a working fluid, the working fluid path
being fluidly coupled to the expander/compressor portion. A boiler
portion is fluidly coupled to the working fluid path, the boiler
portion further being thermally coupled to the exhaust portion. An
accumulator tank portion having a cavity is operative to receive
and store the working fluid, the accumulator tank portion fluidly
coupled to the inlet valve and the exhaust valve. A condenser is
fluidly coupled to the working fluid path and the exhaust
valve.
Inventors: |
Hendrickson; James D.;
(Oxford, MI) ; Bucknell; John R.; (Royal Oak,
MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GM GLOBAL TECHNOLOGY OPERATIONS LLC |
Detroit |
MI |
US |
|
|
Assignee: |
GM GLOBAL TECHNOLOGY OPERATIONS
LLC
Detroit
MI
|
Family ID: |
50928599 |
Appl. No.: |
14/099065 |
Filed: |
December 6, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61746704 |
Dec 28, 2012 |
|
|
|
Current U.S.
Class: |
60/273 ;
60/320 |
Current CPC
Class: |
Y02E 20/14 20130101;
F01K 23/14 20130101; F01K 23/065 20130101; F01K 23/10 20130101;
F01K 15/02 20130101 |
Class at
Publication: |
60/273 ;
60/320 |
International
Class: |
F01K 23/10 20060101
F01K023/10 |
Claims
1. A waste heat recovery system for a vehicle, the system
comprising: an expander/compressor portion is mechanically linked
to wheels of the vehicle, the expander/compressor portion including
an inlet valve and an exhaust valve; a combustion engine having an
exhaust portion; a working fluid path having a working fluid, the
working fluid path being thermally coupled to exchange heat between
the combustion engine and the working fluid, the working fluid path
being fluidly coupled to the expander/compressor portion; a boiler
portion having a heat exchange portion that is fluidly coupled to
the working fluid path, the boiler portion further being thermally
coupled to the exhaust portion; an accumulator tank portion having
a cavity that is fluidly coupled to receive and store the working
fluid, the accumulator tank portion being fluidly coupled to the
working fluid path, the inlet valve and the exhaust valve of the
expander/compressor portion; and a condenser fluidly coupled to the
working fluid path and the exhaust valve.
2. The system of claim 1, further comprising a pump portion fluidly
coupled to the working fluid path between the condenser and the
combustion engine.
3. The system of claim 1, further comprising a processor operative
to control the system, wherein the processor is operative to
control a vehicle driving mode that includes: operating the
combustion engine to exchange heat with the working fluid; control
an output of the working fluid from the boiler portion to the
expander/compressor portion; and control the expander/compressor
portion such that the expander/compressor portion drives the wheels
of the vehicle.
4. The system of claim 1, further comprising a processor operative
to control the system, wherein the processor is operative to
control an accumulator charging mode that includes: operating the
combustion engine and exchanging heat with the working fluid;
controlling an output of the working fluid from the boiler portion
to the accumulator tank portion; and controlling the accumulator
tank portion to receive and store the working fluid.
5. The system of claim 1, further comprising a processor operative
to control the system, wherein the processor is operative to
control an accumulator tank depletion mode that includes:
controlling the accumulator tank portion to output the working
fluid to the expander/compressor portion; and controlling the
expander/compressor portion to receive the working fluid from the
accumulator tank portion and drive the wheels of the vehicle.
6. The system of claim 1, further comprising a processor operative
to control the system, wherein the processor is operative to
control a regenerative breaking mode that includes: controlling the
expander/compressor portion to receive the working fluid from the
boiler portion, compressing the working fluid by being driven by
the wheels of the vehicle, and outputting compressed working fluid
to the accumulator tank portion; and controlling the accumulator
tank portion to receive and store the compressed working fluid.
7. The system of claim 1, further comprising a processor operative
to control the system, wherein the processor is operative to
control a warm up mode that includes controlling an output of the
working fluid from the boiler portion to the engine such that the
working fluid heats the engine.
8. The system of claim 1, wherein the boiler portion is operative
to receive the working fluid from the combustion engine at a high
pressure and medium temperature and output the working fluid at a
high pressure and high temperature.
9. A waste heat recovery system for a vehicle, the system
comprising: an expander/compressor portion mechanically linked to
wheels of the vehicle, the expander/compressor portion including a
primary inlet valve, a secondary inlet valve and an exhaust valve;
a combustion engine having an exhaust portion, the exhaust portion
having an exhaust gas path; a working fluid path having a working
fluid, the working fluid path being thermally coupled to the
combustion engine and fluidly coupled to the to the secondary inlet
valve of the expander/compressor portion; a boiler portion having a
heat exchange portion thermally coupled to the exhaust gas path; an
accumulator tank portion that includes a cavity operative to
receive and store the working fluid, the accumulator tank portion
fluidly coupled to the working fluid path and the primary inlet
valve; and a condenser portion fluidly coupled between the exhaust
valve and the boiler portion.
10. The system of claim 9, further comprising a pump portion
fluidly coupled to the working fluid path between the condenser
portion and the combustion engine.
11. The system of claim 9, further comprising a processor operative
to control the system, wherein the processor is operative to
control a vehicle driving mode that includes: operating the
combustion engine to exchange heat with the working fluid;
controlling an output of the working fluid from the combustion
engine to the expander/compressor portion; controlling an output of
the working fluid from the boiler portion to the
expander/compressor portion; and controlling the
expander/compressor portion such that the expander/compressor
portion drives the wheels of the vehicle.
12. The system of claim 9, further comprising a processor operative
to control the system, wherein the processor is operative to
control an accumulator charging mode that includes: operating the
combustion engine to exchange heat with the working fluid;
controlling an output of the working fluid from the boiler portion
to the accumulator tank portion; and controlling the accumulator
tank portion to receive and store the working fluid.
13. The system of claim 9, further comprising a processor operative
to control the system, wherein the processor is operative to
control an accumulator tank depletion mode that includes:
controlling the accumulator tank portion to output the working
fluid to the expander/compressor portion; and controlling the
expander/compressor portion to receive the working fluid from the
accumulator tank portion and drive the wheels of the vehicle.
14. The system of claim 9, further comprising a processor operative
to control the system, wherein the processor is operative to
control a regenerative breaking mode that includes: controlling the
expander/compressor portion to receive the working fluid from the
boiler portion, compressing the working fluid by being driven by
the wheels of the vehicle, and outputting compressed working fluid
to the accumulator tank portion; and controlling the accumulator
tank portion to receive and store the compressed working fluid.
15. The system of claim 9, further comprising a processor operative
to control the system, wherein the processor is operative to
control a warm up mode that includes controlling an output of the
working fluid from the boiler portion to the engine such that the
working fluid heats the engine.
16. The system of claim 9, wherein the boiler portion is operative
to receive the working fluid from the combustion engine at a high
pressure and medium temperature and output the working fluid at a
high pressure and high temperature.
17. A method of operating a waste heat recovery system for a
vehicle having wheels, the method comprising: operating a
combustion engine to exchange heat with a working fluid; outputting
the working fluid from the combustion engine to an accumulator
tank; and storing the working fluid in the accumulator tank.
18. The method of claim 17 further comprising: following the
storing the working fluid in the accumulator tank, outputting the
working fluid from the accumulator tank to an expander/compressor
portion; driving the expander/compressor portion with the working
fluid; and driving the wheels of the vehicle with the
expander/compressor portion.
19. The method of claim 18, further comprising: following the
driving the wheels of the vehicle with the expander/compressor
portion, receiving the working fluid in the expander/compressor
portion; driving the expander/compressor portion with the wheels of
the vehicle; compressing the working fluid with the
expander/compressor portion; outputting compressed working fluid
from the expander/compressor portion to the accumulator tank
portion; and storing the compressed working fluid in the
accumulator tank portion.
20. The method of claim 17, further comprising: outputting the
working fluid from the accumulator tank portion to an
expander/compressor portion; driving the expander/compressor
portion with the working fluid; and driving the wheels of the
vehicle with the expander/compressor portion.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims priority to U.S. Patent
Application Ser. No. 61/746,704 filed Dec. 28, 2012 which is hereby
incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The subject invention relates to combustion engines and
waste heat recovery in combustion engines.
BACKGROUND
[0003] Combustion engines such as internal combustion engines used
in vehicles consume fuel through a combustion process. The
combustion process produces heat that is wasted when the heat is
not used for productive purposes.
[0004] Accordingly, it is desirable to provide a system that
utilizes the waste heat to provide more efficient operation of the
system.
SUMMARY OF THE INVENTION
[0005] According to one embodiment, a system and method of
operating a waste heat recovery system for a vehicle is provided.
The system includes an expander/compressor portion mechanically
linked to wheels of the vehicle, the expander/compressor portion
including an inlet valve and an exhaust valve. A combustion engine
is provided having an exhaust portion. A working fluid path is
thermally coupled between the combustion engine and a working
fluid, the working fluid path being fluidly coupled to the
expander/compressor portion. A boiler portion is fluidly coupled to
the working fluid path, the boiler portion further being thermally
coupled to the exhaust portion. An accumulator tank portion having
a cavity is operative to receive and store the working fluid, the
accumulator tank portion fluidly coupled to the inlet valve and the
exhaust valve. A condenser is fluidly coupled to the working fluid
path and the exhaust valve
[0006] According to another embodiment, a waste heat recovery
system for a vehicle is provided. The system including an
expander/compressor portion mechanically linked to wheels of the
vehicle, the expander/compressor portion including a primary inlet
valve, a secondary inlet valve and an exhaust valve. A combustion
engine is provided having an exhaust portion, the exhaust portion
having an exhaust gas path. A working fluid path is provided having
a working fluid, the working fluid path being thermally coupled to
the combustion engine and fluidly coupled to the to the secondary
inlet valve of the expander/compressor portion. A boiler portion is
provided having a heat exchange portion thermally coupled to the
exhaust gas path. An accumulator tank portion that includes a
cavity is operative to receive and store the working fluid, the
accumulator tank portion fluidly coupled to the working fluid path
and the primary inlet valve. A condenser portion is fluidly coupled
between the exhaust valve and the boiler portion.
[0007] According to yet another embodiment a method of operating a
waste heat recovery system for a vehicle having wheels is provided.
The method including operating a combustion engine to exchange heat
with a working fluid. The working fluid is output from the
combustion engine to an accumulator tank. The working fluid is
stored in the accumulator tank.
[0008] The above features and advantages and other features and
advantages of the invention are readily apparent from the following
detailed description of the invention when taken in connection with
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Other features, advantages and details appear, by way of
example only, in the following detailed description of embodiments,
the detailed description referring to the drawings in which:
[0010] FIG. 1 illustrates an exemplary heat waste recovery
system;
[0011] FIG. 2 illustrates an exemplary "driving vehicle mode" of
the system of FIG. 1;
[0012] FIG. 3 illustrates an exemplary "accumulator charging mode"
of the system of FIG. 1;
[0013] FIG. 4 illustrates an exemplary "accumulator tank depletion
mode" of the system of FIG. 1;
[0014] FIG. 5 illustrates an exemplary "regenerative breaking mode"
of the system;
[0015] FIG. 6 illustrates a graphical representation of the torque
output by the system over time of FIG. 1;
[0016] FIG. 7 illustrates an another embodiment of a waste heat
recovery system;
[0017] FIG. 8 illustrates an exemplary "driving vehicle mode" of
the system of FIG. 7;
[0018] FIG. 9 illustrates an exemplary "accumulator charging mode"
of the system of FIG. 7;
[0019] FIG. 10 illustrates an exemplary "accumulator tank depletion
mode" of the system of FIG. 7;
[0020] FIG. 11 illustrates an exemplary "regenerative breaking
mode" of the system of FIG. 7; and
[0021] FIG. 12 illustrates an exemplary embodiment of a control
system for a waste heat recovery system.
DESCRIPTION OF THE EMBODIMENTS
[0022] The following description is merely exemplary in nature and
is not intended to limit the present disclosure, its application or
uses. It should be understood that throughout the drawings,
corresponding reference numerals indicate like or corresponding
parts and features.
[0023] Combustion engines, such as internal combustion engines for
example, produce of waste heat during the combustion process. The
waste heat was typically transferred into the atmosphere, resulting
in a significant inefficiency in the engine system. The
inefficiency increases the fuel needed to drive the system, and
reduces the fuel economy of the system. The methods and systems
described below provide a more efficient engine system for a
vehicle using the waste heat produced by the engine and from
braking or slowing of the vehicle to produce steam that is used to
assist in driving the vehicle.
[0024] In accordance with an exemplary embodiment of the invention,
FIG. 1 illustrates an exemplary system 100. The system 100 includes
a combustion engine 102 that receives intake air via a turbo
charger 104 and outputs exhaust gasses via a catalyst portion 106.
The engine 102 is cooled by a high pressure (HP), low temperature
(LT) working fluid, such as a refrigerant such as R134a for
example. The working fluid receives engine heat from for example,
coolant water that circulates through a heat exchanger portion 103.
A pump 105 may circulate the coolant water through the engine 102
and the heat exchanger portion 103. The HP/LT fluid received by the
engine 102, and following a heat exchange in the engine, is output
as HP medium temperature (MT) fluid to a boiler portion 108. The
boiler portion 108 is a heat exchanging device that may include,
for example, tubes that propagate the working fluid and receive
thermal energy from the exhaust gasses (output by the engine 102)
that flow through the boiler portion 108 (around the tubes
propagating the working fluid) and transfer heat to the working
fluid. The boiler portion 108 outputs the working fluid as a high
pressure and high temperature (HT) gas. An exhaust flow regulating
valve 107 may be used to regulate the temperature of the boiler
portion 108, and in-turn, the pressure of the working fluid output
by the boiler portion 108. The exhaust flow regulating valve 107 is
operative to control the flow of the exhaust gas from the engine
102 and regulate the amount of exhaust that passes through the
boiler portion 108 or is output to the atmosphere via a boiler
bypass path 109. A boiler check valve 110 is arranged to control
the flow of working fluid from the boiler portion 108 to limit or
check the backflow of working fluid into the boiler portion 108. A
boiler recirculation valve 111 is arranged to control the flow of
working fluid that may recirculate to the heat exchanger portion
103. For a working fluid that includes R134a refrigerant the
temperature and pressure ranges may include for example: HT,
125.degree. C.-200.degree. C.; MT, 55.degree. C.-125.degree. C.;
LT<55.degree. C. HP, 40 Bar-150 Bar; MP, 15 Bar-40 Bar; LP 5
Bar-15 Bar.
[0025] An accumulator tank portion 112 is arranged with a first
accumulator control valve 114 that controls the flow of working
fluid from the boiler portion 108 into the accumulator tank portion
112. An expander/compressor (E/C) portion 116 is arranged with
inlet valves 118 and exhaust valves 120 that control the flow of
working fluid into and out of the E/C portion 116. The E/C portion
116 may be mechanically linked to wheels 101 of the vehicle. A
second accumulator control valve 122 is arranged to control the
flow of the working fluid that may be output by the
expander/compressor portion 116 to the accumulator tank portion
112. A condenser portion 124 is operative to receive low pressure
(LP) high temperature working fluid output by the
expander/compressor portion 116, and condense the working fluid
from a gas to a liquid. A condenser control valve 126 is arranged
to control the flow of the working fluid into the condenser portion
124. A condenser check valve 113 may be arranged to limit or check
a backflow of the working fluid into the condenser portion 124. A
pump portion 128 may be mechanically driven by the engine 102 or
may be electrically driven via an electrical power source such as,
for example, a battery (not shown). The pump portion 128 is
arranged to receive LP-LT working fluid from the condenser and
output HP-LT working to the engine 102. A pressure regulating
portion 130 is arranged to regulate the pressure of the working
fluid output by the pump portion 128.
[0026] The system 100 described above is operative to use the
working fluid to drive the vehicle during a variety of operational
modes of the vehicle. In this regard, the operation of the system
100 in a number of operating modes is described below. As described
herein, "drive" includes imparting a force operative to move or
affect the movement of a component or object.
[0027] The system 100 may operate in a "warm up mode" that is
operative to heat the engine quickly during a warm up period
following starting the engine 102. In this regard, referring to
FIG. 1, once the engine 102 is started, the working fluid flows
through the boiler portion 108 and is heated by the exhaust gas
output by the engine 102. The boiler recirculation valve 111 is
open, which provides a recirculation path for the working fluid
that is output by the boiler portion 108 to flow into the heat
exchanger portion 103 to heat the coolant water in the engine 102.
The pump 128 is operative to pressurize and circulate the working
fluid. The "warm up mode" decreases warm up time of the engine 102.
Once the engine 102 has reached a desired operating temperature,
the system 100 may transition into another operating mode.
[0028] FIG. 2 illustrates an exemplary "driving vehicle mode" of
the system 100. In the vehicle driving mode, the engine 102 may be
operating by combusting fuel, and providing mechanical torque to
the drive train of the vehicle alternatively, the engine 102 may be
idle, or the engine 102 may not be combusting fuel (i.e. if the
engine 102 is not combusting fuel, the engine 102 may provide
thermal energy to the working fluid due to residual heat that is
stored in the engine components and the catalyst portion 106
following the operation of the engine 102). Referring to FIG. 2,
the working fluid enters the heat exchanger portion 103 as a HP-LT
liquid, and exchanges heat with the engine 102. The working fluid
exits the heat exchanger portion 103 as a HP-MT fluid and enters
the boiler portion 108. The working fluid exchanges heat with
exhaust gas from the engine 102 (via the catalyst 106) in the
boiler portion 108, which outputs the working fluid as a HP-HT gas.
The first accumulator control valve 114 and the second accumulator
control valve 122 are closed. The inlet valves 118 and the exhaust
valves 120 of the E/C portion 116 are intermittently opened and
aligned such that the working fluid in a HP-HT state enters the
expander/compressor portion 116 and expand to drive the E/C portion
116. The driving of the E/C portion 116 by the working fluid is
operative to drive the wheels 101 of the vehicle. The condenser
control valve 126 is open such that the E/C portion 116 outputs the
working fluid as a LP-HT or as LP-MT gas to the condenser portion
124. The condenser portion 124 condenses the working fluid to a
LP-LT liquid and outputs the working fluid to the pump portion 128.
The boiler recirculation valve 111 is closed. The pump portion 128
pressurizes the working fluid into a HP-LT liquid that is provided
to the engine 102.
[0029] FIG. 3 illustrates an exemplary "accumulator charging mode"
of the system 100. In the accumulator charging mode, the system 100
is operative to provide HP-HT working fluid gas to the accumulator
tank portion 112. In this regard, referring to FIG. 3, the boiler
recirculation valve 111 is closed. The HP-HT working fluid is
output from the boiler portion 108. The first accumulator control
valve 114 is in an open state and the second accumulator control
valve 122 is in a closed state such that the accumulator tank
receives and stores the HP-HT working fluid output from the boiler
portion 108. The condenser control valve 126 is either in a closed
or open state. The inlet valves 118 and the exhaust valves 120 of
the E/C portion 116 are inactive in that they remain closed to
prevent HP-HT gas from entering or exiting the E/C.
[0030] FIG. 4 illustrates an exemplary "accumulator tank depletion
mode" of the system 100. In the accumulator tank depletion mode,
the system is operative to provide HP-HT working fluid to the E/C
portion 116. The boiler recirculation valve 111 is closed. The E/C
portion 116 is aligned to receive the HP-HT working fluid and
expand the working fluid to drive the wheels 101 of the vehicle. In
this regard, referring to FIG. 4, the first accumulator control
valve 114 is in an open state. The second accumulator control valve
122 is in a closed state. The accumulator portion 112 outputs HT-HP
working fluid to the E/C portion 116. In this state, the
accumulator 112 pressure exceeds the pressure at the outlet of the
boiler 108, thereby closing the one-way valve 110 which in turns
prevents back-flow into the boiler from the accumulator. The states
of the inlet valves 118 and the exhaust valves 120 of the E/C
portion 116 are controlled to allow the E/C portion 116 to receive
and expand the HT-HP working fluid from the accumulator tank
portion 112 and drive the E/C portion 116, which drives the wheels
101 of the vehicle. The condenser control valve 126 is in an open
state to receive the LP-HT working fluid output by the E/C portion
116 and condense the working fluid as described above.
[0031] FIG. 5 illustrates an exemplary "regenerative breaking mode"
of the system 100. In the regenerative breaking mode, the engine
102 may be idle or not combusting fuel. The E/C portion 116 is
aligned to receive the working fluid as a LP-MT gas from the boiler
portion 108 and compress the working fluid into a HP-HT gas. The
HT-HP working fluid is output from the E/C portion 116 to the
accumulator tank portion 112. In this regard, referring to FIG. 5,
the exhaust flow regulating valve 107 may be aligned to regulate
the engine exhaust gas to bypass the boiler portion 108. The boiler
recirculation valve 111 is closed. The first accumulator control
valve 114 is in a closed state. The inlet valves 118 and the
exhaust valves 120 are aligned in an open state such that the MP-MT
fluid output by the boiler portion 108 is compressed by the E/C
portion 116 into a HP-HT fluid. The wheels 101 of the vehicle drive
the E/C portion 116, which in turn compresses the working fluid.
The condenser control valve 126 is in a closed state. The second
accumulator control valve 122 is in an open state such that the
HP-HT working fluid is received and stored in the accumulator tank
portion 112.
[0032] FIG. 6 illustrates a graphical representation of the torque
output by the system 100 over time. In this regard, the "desired
torque" "a" curve illustrates a desired torque response of the
system 100. The "internal combustion engine (ICE) torque" "b" curve
illustrates the torque output by the engine 102. The "heat recovery
torque" "c" curve illustrates the torque output by the E/C portion
116 using working fluid received from the boiler portion 108. The
"heat recovery+ICE torque" "d" curve illustrates the torque output
by the E/C portion 116 and the engine 102.
[0033] In this regard, the region I illustrates the system 100 in a
constant torque output state in region I the system 100 may operate
in the "driving vehicle mode" described above. The region II
illustrates the system 100 in an increasing torque output state
during the operation of the system 100 in region II the system 100
may also operate in the "driving vehicle mode" described above. The
desired torque curve is greater than the heat recovery+ICE torque
curve in the region III. When the desired torque curve is greater
than the heat recovery+ICE torque curve, the system 100 may operate
in the "accumulator tank depletion mode" such that working fluid
stored in the accumulator tank portion 112 is provided to the E/C
portion 116 to provide additional working fluid to drive the E/C
portion 116 such that the E/C portion 116 outputs additional torque
to raise the output torque to approximately match the desired
torque curve.
[0034] In the region IV, the system 100 is outputting a
substantially constant torque. In the region IV, the system 100 may
also operate in the "driving vehicle mode" described above. In the
region V, the system 100 is outputting a reduced torque. The region
V heat recovery+ICE torque curve is greater than the desired torque
curve. During the region V, the system 100 may operate in a
"regenerative breaking mode" or a "accumulator charging mode" as
described above to provide HP-HT working fluid to the accumulator
tank portion 112. The system 100 in the region VI is outputting a
substantially constant torque, and may operate in the "driving
vehicle mode" as described above.
[0035] FIG. 7 illustrates another embodiment of a system 700 that
includes a two stage E/C portion 716. The system 700 is similar in
operation as the system 100 described above. The system 700
includes a first pressure regulating portion 730 and a second
pressure regulating portion 732. The first pressure regulating
portion 730 is operative to receive working fluid from the pump 128
and regulate the pressure of the output working fluid that is
output to the boiler portion 108. The second pressure regulating
portion 732 is operative to receive working fluid output by the
first pressure regulating portion 730 and regulate the pressure of
the working fluid output to the engine heat exchanger portion
103.
[0036] FIG. 8 illustrates an exemplary "driving vehicle mode" of
the system 700. A portion of the working fluid exits the first
pressure regulating portion 730 as a HP-LT fluid and enters the
boiler portion 108. The working fluid exchanges heat with the
exhaust gasses from the engine 102 and is output from the boiler
portion 108. The primary expander control valve 702 is in an open
state. The working fluid enters the E/C portion 716 via the primary
inlet valves 718. Another portion of the working fluid is output
from the pump 128 to the engine coolant heat exchanger 103 where
the working fluid exchanges heat with the engine 102 and is output
by the engine as a HP-MT fluid. The working fluid passes through
the secondary expander control valve 706 and enters the E/C portion
716 via the secondary inlet valves 704. The working fluid in the
E/C portion 716 expands and drives the E/C portion that is
mechanically linked to the wheels 101 of the vehicle. The working
fluid exits the E/C portion via the exhaust valves 120 and enters
the condenser 124 where the working fluid is condensed into a LP-LT
fluid that is input to the pump portion 128.
[0037] FIG. 9 illustrates an exemplary "accumulator charging mode"
of the system 700. In the accumulator charging mode, the system 700
is operative to provide HP-HT working fluid gas output from the
boiler portion 108 to the accumulator tank portion 112. The
accumulator control valve 114 is in an open state and the primary
expander control valve 702 is in a closed state such that the
accumulator tank receives and stores the HP-HT working fluid output
from the boiler portion 108.
[0038] FIG. 10 illustrates an exemplary "accumulator tank depletion
mode" of the system 700. In the accumulator tank depletion mode,
the system is operative to provide HP-HT working fluid to the E/C
portion 716. The E/C portion 716 is aligned to receive the HP-HT
working fluid and expand the working fluid to drive the wheels 101
of the vehicle. In this regard accumulator control valve 114 is in
an open state and the primary expander control valve 702 is in an
open state. The secondary expander control valve 706 is in a closed
state. The accumulator portion 112 outputs HT-HP working fluid to
the E/C portion 716. The states of the inlet valves 718 and the
exhaust valves 120 of the E/C portion 716 allow the E/C portion 716
to receive and expand the HT-HP working fluid from the accumulator
tank portion 112 and drive the E/C portion 716, which drives the
wheels 101 of the vehicle.
[0039] FIG. 11 illustrates an exemplary "regenerative breaking
mode" of the system 700. In the regenerative breaking mode, the
engine 102 may be idle or may not be combusting fuel. The E/C
portion 716 is aligned to receive the working fluid as a LP-MT gas
from the engine 102 and compress the working fluid into a HP-HT gas
by being driven by the wheels 101 of the vehicle. The HT-HP working
fluid is output from the E/C portion 716 to the accumulator tank
portion 112. In this regard the secondary expander control valve
706 is in an open state. The secondary inlet valves 704 are in an
open state such that LP-MT working fluid is input into the E/C
portion 716. The exhaust valves 120 are in a closed state, and the
primary inlet valves 718 are in an open state such that the HT-HP
working fluid is output by the E/C portion 716 via the primary
inlet valves 718. The primary expander control valve 702 and the
accumulator control valves 114 are in an open state such that the
HP-HT working fluid is received and stored in the accumulator tank
portion 112.
[0040] FIG. 12 illustrates an exemplary embodiment of a control
system 1200 that includes a processor 1202 that is operative to
control the systems described above using logic. The processor 1202
that is communicatively connected to input devices 1206, such as
sensors and other diagnostic devices operative to sense states of
the systems 100 and 700 (of FIGS. 1 and 7) for example. The
processor 1202 is communicatively connected to a memory device
1208. The processor 1202 is operative to process signals input from
the input devices 1206 and perform control logic to output control
signals 1210 that are operative to control, for example, the engine
102, valves, and other components of the systems 100 and 700
described above. The control system 1200 may include a display
device 1204 communicatively connected to the processor 1202. Though
the illustrated embodiment includes a single processor 1202, the
processor 1202 may include any number of processors or subsystems
that are operative to control the systems 100 and 700.
[0041] The methods and systems described herein provide a system
for a vehicle that recovers waste heat from an engine and from
braking or slowing the vehicle and utilizes the waste heat to drive
the wheels of the vehicle or other associated subsystems of the
vehicle. The use of the waste heat provides improved efficiency in
the systems.
[0042] While the invention has been described with reference to
exemplary embodiments, it will be understood by those skilled in
the art that various changes may be made and equivalents may be
substituted for elements thereof without departing from the scope
of the invention. In addition, many modifications may be made to
adapt a particular situation or material to the teachings of the
invention without departing from the essential scope thereof.
Therefore, it is intended that the invention not be limited to the
particular embodiments disclosed, but that the invention will
include all embodiments falling within the scope of the
application.
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