U.S. patent application number 14/982041 was filed with the patent office on 2016-04-21 for waste heat recovery system of engine.
This patent application is currently assigned to Caterpillar Inc.. The applicant listed for this patent is Caterpillar Inc.. Invention is credited to Andrew M. Denis.
Application Number | 20160108790 14/982041 |
Document ID | / |
Family ID | 55748652 |
Filed Date | 2016-04-21 |
United States Patent
Application |
20160108790 |
Kind Code |
A1 |
Denis; Andrew M. |
April 21, 2016 |
WASTE HEAT RECOVERY SYSTEM OF ENGINE
Abstract
A waste heat recovery system of an engine is provided. The waste
heat recovery system includes an inlet member adapted to introduce
exhaust gases in the aftertreatment system, and an outlet member
adapted to receive the exhaust gases from the Selective Catalytic
Reduction module. The outlet member includes a first surface
defining a passage, and a second surface coupled with a power
generation module. The power generation module includes a plurality
of power generating units having a first lead and a second lead.
The power generating units are adapted to generate electric power
based on a temperature gradient between the first and second lead.
At least one of the first lead and the second lead is exposed to
the exhaust gases. An electric load is coupled with the plurality
of power generating units for utilizing the power generated by the
plurality of power generating units.
Inventors: |
Denis; Andrew M.; (Peoria,
IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Caterpillar Inc. |
Peoria |
IL |
US |
|
|
Assignee: |
Caterpillar Inc.
Peoria
IL
|
Family ID: |
55748652 |
Appl. No.: |
14/982041 |
Filed: |
December 29, 2015 |
Current U.S.
Class: |
60/301 |
Current CPC
Class: |
F01N 3/2066 20130101;
Y02T 10/12 20130101; F01N 13/009 20140601; F01N 13/0093 20140601;
F01N 5/025 20130101; Y02T 10/16 20130101; Y02T 10/24 20130101; F01N
2470/22 20130101 |
International
Class: |
F01N 5/02 20060101
F01N005/02; F01N 3/20 20060101 F01N003/20 |
Claims
1. A waste heat recovery system of an engine having an
aftertreatment system, the waste heat recovery system comprising:
an inlet member adapted to introduce exhaust gases in the
aftertreatment system; a Selective Catalytic Reduction (SCR) module
in fluid communication and attached downstream to the inlet member;
and an outlet member adapted to receive the exhaust gases from the
SCR module and attached downstream of the SCR module, the outlet
member including: a first surface defining a passage for flow of
the exhaust gases therethrough; and a second surface coupled with a
power generation module, the power generation module including a
plurality of power generating units, the plurality of power
generating units having a first lead and second lead, the plurality
of power generating units adapted to generate electric power based
on a temperature gradient between the first lead and the second
lead, wherein at least one of the first lead and the second lead is
exposed to the exhaust gases flowing through the passage; wherein
an electric load is coupled with the plurality of power generating
units, the electric load adapted to utilize the power generated by
the plurality of power generating units.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a waste heat recovery
system associated with an engine system, and more particularly to a
waste heat recovery system for generating power from exhaust gases
exiting the engine system.
BACKGROUND
[0002] In an engine, thermal energy generated by combustion of air
and fuel mixture is converted into mechanical energy. During this
energy conversion process, a portion of the thermal energy is
converted to useful work and remaining portion is wasted in the
form of heat into atmosphere via various engine components. Thus,
an effective utilization of the thermal energy generated by the
engine is challenged.
[0003] U.S. Patent Publication number 2010/0186399, hereinafter
referred to as the '399 publication, describes a thermoelectric
facility contains a thermoelectric generator. The thermoelectric
generator is thermally connected on a first side to a heat source
and on a second side to a heat sink. The thermoelectric facility
also has a structure for limiting the temperature on the
thermoelectric generator. The structure includes a first
compartment, filled with a first working medium that can melt,
which compartment is connected across a large surface thereof to
the heat source or to a second compartment that is filled with an
evaporable second working medium. The second compartment is
connected to the thermoelectric generator on its side facing away
from the first compartment. The working media have a predetermined
melting point or boiling point in order to prevent permanent
damages to the thermoelectric generator. The thermoelectric
facility is especially useful for motor vehicles that are operated
by an internal combustion engine. However, the thermoelectric
facility described in the '399 publication includes multiple
components that makes the facility complex in operation and also
increases an overall cost associated with energy generation.
SUMMARY OF THE DISCLOSURE
[0004] In one aspect of the present disclosure, a waste heat
recovery system of an engine is provided. The engine includes an
aftertreatment system. The waste heat recovery system includes an
inlet member adapted to introduce exhaust gases in the
aftertreatment system. The waste heat recovery system also includes
a Selective Catalytic Reduction (SCR) module in fluid communication
and attached downstream to the inlet member. The waste heat
recovery system further includes an outlet member adapted to
receive the exhaust gases from the SCR module and attached
downstream of the SCR module. The outlet member includes a first
surface defining a passage for flow of the exhaust gases
therethrough. The outlet member also includes a second surface
coupled with a power generation module. The power generation module
includes a plurality of power generation units. The plurality of
power generation units includes a first lead and a second lead. The
plurality of power generating units is adapted to generate electric
power based on a temperature gradient between the first lead and
the second lead. Also, at least one of the first lead and the
second lead is exposed to the exhaust gases flowing through the
passage. Further, an electric load is coupled with the plurality of
power generating units. The electric load is adapted to utilize the
power generated by the plurality of power generating units.
[0005] Other features and aspects of this disclosure will be
apparent from the following description and the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a schematic view of an exemplary engine system,
according to one embodiment of the present disclosure;
[0007] FIG. 2 is a perspective view of an aftertreatment system and
a waste heat recovery system associated with the engine system of
FIG. 1, according to one embodiment of the present disclosure;
[0008] FIG. 3 is a perspective view of an outlet member of the
aftertreatment system associated with the waste heat recovery
system of FIG. 2, according to one embodiment of the present
disclosure; and
[0009] FIG. 4 is a block diagram depicting an application of the
waste heat recovery system, according to one embodiment of the
present disclosure.
DETAILED DESCRIPTION
[0010] Reference will now be made in detail to specific embodiments
or features, examples of which are illustrated in the accompanying
drawings. Wherever possible, corresponding or similar reference
numbers will be used throughout the drawings to refer to the same
or corresponding parts.
[0011] FIG. 1 is a schematic view of an exemplary engine system 10,
according to one embodiment of the present disclosure. The engine
system 10 includes an engine 12 which may be an internal combustion
engine, such as, a reciprocating piston engine or a gas turbine
engine. In one example, the engine 12 may be a spark ignition
engine or a compression ignition engine, such as, a diesel engine,
a homogenous charge compression ignition engine, or other
compression ignition engine known in the art. In one example, the
engine 12 may be fueled by gasoline, diesel fuel, biodiesel,
alcohol, natural gas, propane, combinations thereof, or any other
combustion fuel known in the art.
[0012] The engine system 10 also includes an aftertreatment system
16 for treating exhaust gases exiting the engine 12. More
particularly, the aftertreatment system 16 is provided to trap or
treat NOx, unburned hydrocarbons, particulate matter, combination
thereof, or other combustion products present in the exhaust gases.
In particular, the aftertreatment system 16 reduces NOx to
relatively less toxic or less polluting end products. An exhaust
conduit 14 provides fluid communication between an exhaust manifold
(not shown) of the engine 12 and the aftertreatment system 16. The
exhaust gases exiting the engine 12 are introduced in the
aftertreatment system 16 by the exhaust conduit 14.
[0013] FIG. 2 is a perspective view of the aftertreatment system
16. The aftertreatment system 16 includes a housing member 22. The
housing member 22 includes a first wall 32 and a second wall 34
that is spaced apart from the first wall 32. The housing member 22
includes an inlet portion 24. The inlet portion 24 is coupled to
the first wall 32 of the housing member 22. An inlet member 36 is
coupled to the housing member 22 via the inlet portion 24. The
inlet member 36 is in fluid communication with the exhaust conduit
14. The inlet member 36 receives and introduces the exhaust gases
in the aftertreatment system 16.
[0014] The aftertreatment system 16 includes a mixing tube 28. The
mixing tube 28 is disposed between the first wall 32 and the second
wall 34 in such a manner that the mixing tube 28 is in alignment
with the inlet portion 24 and the inlet member 36. The mixing tube
28 includes a reductant injector (not shown). The reductant
injector introduces a reductant in the exhaust gases entering the
aftertreatment system 16. The reductant may include, but is not
limited to, ammonia, urea or any other reductant know in the art.
The urea containing solution may include, but is not limited to, an
automotive grade urea, such as, diesel exhaust fluid. Further, the
mixing tube 28 includes mixing elements (not shown) that allow
uniform mixing of the exhaust gases with the reductant. In one
example, the aftertreatment system 16 may also include a Diesel
Oxidation Catalyst (DOC), a Diesel Particulate Filter (DPF), or a
combination thereof, without limiting the scope of the present
disclosure. The DOC/DPF may be positioned upstream of the mixing
tube 28 along an exhaust gas flow direction "F".
[0015] The aftertreatment system 16 includes a Selective Catalytic
Reduction (SCR) Module 30. The SCR module 30 operates to treat the
exhaust gases in the presence of a catalyst, which is provided
after degradation of the reductant injected into the exhaust gases.
The SCR module 30 is positioned downstream of the inlet member 36,
along the exhaust gas flow direction "F". The SCR module 30 is
disposed between the first wall 32 and the second wall 34 of the
housing member 22. The mixing tube 28 and the SCR module 30 have a
flow-through configuration. The flow-through configuration allows
the exhaust gases exiting the mixing tube 28 to flow through the
SCR module 30. The SCR module 30 includes one or more SCR catalysts
31. The SCR catalysts 31 may include, but not limited to, oxides of
base metals, such as vanadium, molybdenum, and tungsten.
[0016] The housing member 22 also includes an outlet portion 26.
The outlet portion 26 is coupled to the first wall 32. The SCR
module 30 is in fluid communication with the outlet portion 26.
Further, an outlet member 38 is coupled to the outlet portion 26.
The outlet member 38 receives the treated exhaust gases from the
outlet portion 26. The outlet member 38 is disposed downstream of
the SCR module 30, with respect to the exhaust gas flow direction
"F".
[0017] FIG. 3 is a perspective view of an outlet member 38 of the
aftertreatment system 16. The outlet member 38 includes a first end
40 and a second end 42. The first end 40 includes a first flange
portion 44 fastened to the outlet portion 26 of the aftertreatment
system 16. The second end 42 includes a second flange portion 46
fastened to a stack 20 (shown in FIG. 1) to release the exhaust
gases in to the atmosphere. The outlet member 38 also includes a
first surface 48 and a second surface 50. The first surface 48
defines a passage 52 for flow of the treated exhaust gases
therethrough. The aftertreatment system 16 explained herein is
exemplary in nature. The aftertreatment system 16 may include
additional components (not shown) based on operational
requirements.
[0018] The aftertreatment system 16 includes a waste heat recovery
system 18. The waste heat recovery system 18 generates electric
power from thermal energy dissipated by the treated exhaust gases
flowing through the outlet member 38. The waste heat recovery
system 18 includes a power generation module 54. The power
generation module 54 is coupled to the second surface 50 of the
outlet member 38.
[0019] The power generation module 54 includes a number of power
generating units 56. Each of the power generating units 56 includes
a first lead 58 (shown in FIG. 4) and a second lead 60. The power
generating units 56 generates electric power based on a temperature
gradient between the first lead 58 and the second lead 60. The
first leads 58 of the power generating units 56 are coupled to the
second surface 50. The first leads 58 are indirectly exposed to the
exhaust gases flowing through the passage 52. In another example,
the second lead 60 may be indirectly exposed to the exhaust gases
flowing through the passage 52, based on system requirements.
[0020] In one example, the first lead 58 of the power generating
units 56 is coupled to the second surface 50 via an adhesive layer
62 (shown in FIG. 4). The adhesive layer 62 may include, but is not
limited to, an epoxy or any other type of adhesive material known
in the industry. The type of the adhesive layer 62 (shown in FIG.
4) is selected based on various parameters. The various parameters
may include, but are not limited to, thermal conductivity of the
adhesive and moisture resistance the adhesive. A total number of
the power generating units 56 disposed on the second surface 50 may
vary based on dimensional characteristics of the outlet member 38.
The dimensional characteristics may include, but are not limited
to, a surface area of the second surface 50. Each of the power
generating units 56 includes plurality of semiconductors (not
shown) disposed between the first lead 58 and the second lead
60.
[0021] During an operation of the engine 12, the treated exhaust
gases flow through the passage 52 of the outlet member 38. The
treated exhaust gases dissipate heat energy to the first surface 48
by a convection mode of heat transfer, thereby increasing a
temperature of the first surface 48. The first surface 48 in turn
dissipates heat energy to the second surface 50 of the outlet
member 38 by a conduction mode of heat transfer, thereby increasing
a temperature of the second surface 50.
[0022] Further, heat energy is transferred from the second surface
50 to the first lead 58 of the power generating units 56 through
the adhesive layer 62, thereby increasing a temperature of the
first lead 58. Also, the second lead 60 of the power generating
units 56 is exposed to the ambient temperature that is lesser than
the temperature of the first lead 58. Due to temperature difference
between the first lead 58 and the second lead 60, the power
generating units 56 yields electric power. In particular, each of
the power generating units 56 generates electric power due to the
temperature gradient between the first lead 58 and the second lead
60. The electric power generated by the power generating units 56
is transferred to an electric load 68 (shown in FIG. 4) via, a
first electric terminal 64 (shown in FIG. 4) and a second electric
terminal 66 (shown in FIG. 4).
INDUSTRIAL APPLICABILITY
[0023] The waste heat recovery system 18 enables the engine system
10 to generate electric power using the thermal energy of the
treated exhaust gases that would otherwise be released into the
atmosphere as waste gases. In particular, the waste heat recovery
system 18 converts the thermal energy dissipated by the treated
exhaust gases into electric power. The electric power can be
utilized for operating a lighting system, a motor, a braking system
of a machine in which the engine 12 is used, and/or any other
electrical component associated with the engine 12.
[0024] The waste heat recovery system 18 eliminates the use of an
electric generator that generates electrical power by using
mechanical power produced from the engine 12, thereby reducing fuel
consumption.
[0025] In one example, the electric power generated by the waste
heat recovery system 18 can be utilized to increase power output of
the engine 12 in addition to mechanical power received from a
crankshaft of the engine 12. The waste heat recovery system 18 can
be employed at the inlet portion 24 or the outlet portion 26 of the
aftertreatment system 16. The waste heat recovery system 18 can be
easily retrofitted to an existing engine system 10. The present
disclosure offers the waste heat recovery system 18 that is
simpler, effective, easy to use, economical, and time saving.
[0026] FIG. 4 is a block diagram depicting an exemplary application
of the waste heat recovery system 18. The waste heat recovery
system 18 generates the electric power based on the temperature
gradient between the first lead 58 and the second lead 60 of the
power generating unit 56. The power generating units 56 also
includes the first electric terminal 64 and the second electric
terminal 66. The first electric terminal 64 and the second electric
terminal 66 are connected to the electric load 68. In this example,
the electric load 68 is embodied as an electrical storage for
storing the electric power generated by the waste heat recovery
system 18.
[0027] The electric power stored in the electrical storage is used
by an inverter 70 to convert DC electric power generated by the
waste heat recovery system 18 to AC electric power. Further, the
inverter 70 supplies the electric power to an electric motor 72 of
the engine system 10. In another example, the inverter 70 may
supply the electric power to any other component of the engine
system 10 or a machine equipped with the engine system 10.
Although, the waste heat recovery system 18 is described with
reference to the aftertreatment system 16, it may be contemplated
that the waste heat recovery system 18 may be coupled to any other
component of the engine system 10 that radiates thermal energy
including, but not limited to, a radiator, a cylinder block, an
exhaust manifold, an oil cooler, and the like.
[0028] While aspects of the present disclosure have been
particularly shown and described with reference to the embodiments
above, it will be understood by those skilled in the art that
various additional embodiments may be contemplated by the
modification of the disclosed remote operating station without
departing from the spirit and scope of what is disclosed. Such
embodiments should be understood to fall within the scope of the
present disclosure as determined based upon the claims and any
equivalents thereof.
* * * * *