U.S. patent application number 16/210933 was filed with the patent office on 2019-06-27 for systems and methods for air assisted injection of a reductant into an aftertreatment system.
This patent application is currently assigned to Cummins Emission Solutions Inc.. The applicant listed for this patent is Cummins Emission Solutions Inc.. Invention is credited to Nicholas Blodgett, Taren DeHart, Shireen Faizi, Stephen M. Holl, Tyler Kent Lorenz, Colin L. Norris.
Application Number | 20190195106 16/210933 |
Document ID | / |
Family ID | 66950065 |
Filed Date | 2019-06-27 |
![](/patent/app/20190195106/US20190195106A1-20190627-D00000.png)
![](/patent/app/20190195106/US20190195106A1-20190627-D00001.png)
![](/patent/app/20190195106/US20190195106A1-20190627-D00002.png)
United States Patent
Application |
20190195106 |
Kind Code |
A1 |
Faizi; Shireen ; et
al. |
June 27, 2019 |
SYSTEMS AND METHODS FOR AIR ASSISTED INJECTION OF A REDUCTANT INTO
AN AFTERTREATMENT SYSTEM
Abstract
An aftertreatment system structured to decompose constituents of
an exhaust produced by an engine having a turbocharger including a
turbine and a compressor coupled thereto, includes: a selective
catalytic reduction system; an injector fluidly coupled to the
selective catalytic reduction system and structured to selectively
insert a reductant into the selective catalytic reduction system;
an intake conduit fluidly coupled to a compressor outlet of the
compressor and structured to deliver a compressed air from the
compressor to the engine; and an air delivery line fluidly coupling
the intake conduit to the injector, the air delivery line
structured to deliver a portion of the compressed air to the
injector.
Inventors: |
Faizi; Shireen; (Columbus,
IN) ; Lorenz; Tyler Kent; (McFarland, WI) ;
Blodgett; Nicholas; (Columbus, IN) ; Norris; Colin
L.; (Columbus, IN) ; Holl; Stephen M.;
(Columbus, IN) ; DeHart; Taren; (Columbus,
IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Cummins Emission Solutions Inc. |
Columbus |
IN |
US |
|
|
Assignee: |
Cummins Emission Solutions
Inc.
Columbus
IN
|
Family ID: |
66950065 |
Appl. No.: |
16/210933 |
Filed: |
December 5, 2018 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
62609712 |
Dec 22, 2017 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F01N 3/208 20130101;
F01N 2610/02 20130101; F01N 2610/085 20130101; F01N 2340/06
20130101; F01N 2270/00 20130101; F01N 3/326 20130101; F01N
2900/1824 20130101; F01N 3/2066 20130101; F01N 2900/1804 20130101;
F01N 2610/08 20130101; F02B 37/168 20130101; F01N 2610/146
20130101 |
International
Class: |
F01N 3/20 20060101
F01N003/20 |
Claims
1. An aftertreatment system, structured to decompose constituents
of an exhaust produced by an engine having a turbocharger including
a turbine and a compressor coupled thereto, the aftertreatment
system comprising: a selective catalytic reduction system; an
injector fluidly coupled to the selective catalytic reduction
system and structured to selectively insert a reductant into the
selective catalytic reduction system; an intake conduit fluidly
coupled to a compressor outlet of the compressor and structured to
deliver a compressed air from the compressor to the engine; and an
air delivery line fluidly coupling the intake conduit to the
injector, the air delivery line being structured to deliver a
portion of the compressed air to the injector so as to facilitate
air-assisted insertion of the reductant by the injector.
2. The aftertreatment system of claim 1, further comprising: a
booster pump positioned in the air delivery line upstream of the
injector; wherein the air delivery line is structured to deliver
the portion of the compressed air within the air delivery line
upstream of the booster pump at a first pressure; and wherein the
booster pump is structured to pressurize the portion of the
compressed air, so as to generate pressurized air having a second
pressure greater than the first pressure, and deliver the
pressurized air to the injector.
3. The aftertreatment system of claim 2, wherein the injector
comprises a nozzle structured to shear the reductant into reductant
droplets using the pressurized air at the second pressure.
4. The aftertreatment system of claim 2, further comprising a flow
valve positioned in the air delivery line upstream of the booster
pump, the flow valve operable between a first state and a second
state, the flow valve structured to facilitate fluid communication
between the intake conduit and the booster pump in the first state
and to prohibit fluid communication between the intake conduit and
the booster pump in the second state.
5. The aftertreatment system of claim 1, wherein the injector
comprises a nozzle structured to shear the reductant into reductant
droplets.
6. The aftertreatment system of claim 1, wherein the portion of the
compressed air has a volume in a range of 0.01-8% of a total volume
of the compressed air flowing through the intake conduit.
7. The aftertreatment system of claim 1, further comprising: an
exhaust conduit fluidly coupled to a turbine inlet of the turbine,
structured to receive exhaust from the engine, and structured to
provide the exhaust from the engine to the turbine; and an inlet
conduit fluidly coupled to a turbine outlet of the turbine, fluidly
coupled to the selective catalytic reduction system separate from
the injector, structured to receive the exhaust from the turbine,
and structured to provide the exhaust from the turbine to the
selective catalytic reduction system.
8. The aftertreatment system of claim 1, further comprising: a
reductant tank structured to store the reductant prior to insertion
of the reductant into the selective catalytic reduction system by
the injector; and a reductant insertion assembly fluidly coupled to
the reductant tank and the injector, the reductant insertion
assembly structured to draw the reductant from the reductant tank
and provide the reductant to the injector.
9. An aftertreatment system for an internal combustion engine, the
aftertreatment system comprising: a turbocharger comprising: a
compressor configured to receive air from an air source; and a
turbine configured to receive exhaust from the internal combustion
engine; an intake conduit configured to receive compressed air from
compressor; an intake manifold configured to receive a first
portion of the compressed air from the intake conduit and to
provide the first portion of the compressed air to the internal
combustion engine; an air delivery line configured to receive a
second portion of the compressed air from the intake conduit
separate from the intake manifold; and a housing configured to
receive the second portion of compressed air from the air delivery
line and to receive the exhaust from the turbine.
10. The aftertreatment system of claim 9, further comprising: a
reductant insertion assembly; and an injector coupled to the
housing and configured to receive the second portion of compressed
air from the air delivery line, receive reductant from the
reductant insertion assembly, mix the second portion of compressed
air and the reductant into an air-reductant mixture, and deliver
the air-reductant mixture into the housing.
11. The aftertreatment system of claim 10, wherein the injector
comprises a nozzle configured to shear the reductant into reductant
droplets using the second portion of the compressed air.
12. The aftertreatment system of claim 9, further comprising: a
booster pump positioned in the air delivery line between the intake
conduit and the housing; wherein the air delivery line is
structured to deliver the first portion of the compressed air at a
first pressure; and wherein the booster pump is configured to
pressurize the second portion of the compressed air to a second
pressure greater than the first pressure.
13. The aftertreatment system of claim 12, further comprising a
flow valve positioned in the air delivery line upstream of the
booster pump, the flow valve operable between a first state and a
second state, the flow valve structured to facilitate fluid
communication between the intake conduit and the booster pump in
the first state and to prohibit fluid communication between the
intake conduit and the booster pump in the second state.
14. The aftertreatment system of claim 9, wherein: the first
portion of the compressed air accounts for a first volume of
compressed air over a period of time; the second portion of the
compressed air accounts for a second volume of compressed air over
the period of time; a sum of the first volume of compressed air and
the second volume of compressed air results in a total volume of
compressed air over the period of time; and the second volume of
compressed air is in a range of 0.01-1% of the total volume of
compressed air over the period of time.
15. An aftertreatment system for an internal combustion engine
having a turbocharger with a compressor and a turbine, the
aftertreatment system comprising: an intake conduit configured to
receive compressed air; an air delivery line coupled to the intake
conduit and structured such that a first portion of the compressed
air bypasses the air delivery line and a second portion of the
compressed air is diverted into the air delivery line; and a
housing structured to receive the second portion of compressed air
from the air delivery line and to separately receive exhaust.
16. The aftertreatment system of claim 15, further comprising: a
reductant insertion assembly; and an injector structured to receive
the second portion of compressed air from the air delivery line,
receive reductant from the reductant insertion assembly, mix the
second portion of compressed air and the reductant into an
air-reductant mixture, and deliver the air-reductant mixture into
the housing.
17. The aftertreatment system of claim 16, further comprising a
booster pump positioned in the air delivery line between the intake
conduit and the housing; wherein the air delivery line is
structured to deliver the first portion of the compressed air at a
first pressure; and wherein the booster pump is structured to
pressurize the second portion of the compressed air to a second
pressure greater than the first pressure.
18. The aftertreatment system of claim 17, further comprising a
flow valve positioned in the air delivery line between the intake
conduit and the booster pump, the flow valve operable between a
first state and a second state, the flow valve structured to
facilitate fluid communication between the intake conduit and the
booster pump in the first state and to prohibit fluid communication
between the intake conduit and the booster pump in the second
state.
19. The aftertreatment system of claim 18, wherein the injector
comprises a nozzle configured to shear the reductant into reductant
droplets using the second portion of the compressed air.
20. The aftertreatment system of claim 19, wherein, over a period
of time: the first portion of the compressed air accounts for a
first volume of compressed air; the second portion of the
compressed air accounts for a second volume of compressed air; a
sum of the first volume of compressed air and the second volume of
compressed air results in a total volume of compressed air; and the
second volume of compressed air is in a range of 0.01-1% of the
total volume of compressed air or is in a range of 1-8% of the
total volume of compressed air.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATION
[0001] This application claims the benefit of and priority to U.S.
Provisional Patent Application No. 62/609,712, filed Dec. 22, 2017,
the entire disclosure of which is incorporated herein by
reference.
TECHNICAL FIELD
[0002] The present disclosure relates generally to aftertreatment
systems for use with internal combustion (IC) engines.
BACKGROUND
[0003] Exhaust aftertreatment systems are used to receive and treat
exhaust gas generated by IC engines. Generally, exhaust gas
aftertreatment systems comprise any of several different components
to reduce the levels of harmful exhaust emissions present in the
exhaust gas. For example, certain exhaust gas aftertreatment
systems for diesel-powered IC engines comprise a selective
catalytic reduction (SCR) system, including a catalyst formulated
to convert NO.sub.x (NO and NO.sub.2 in some fraction) into
harmless nitrogen gas (N.sub.2) and water vapor (H.sub.2O) in the
presence of ammonia (NH.sub.3). Generally, in such aftertreatment
systems, an exhaust reductant (e.g., a diesel exhaust fluid such as
urea) is injected into the SCR system to provide a source of
ammonia and mixed with the exhaust gas to partially reduce the
NO.sub.x gases. The reduction byproducts of the exhaust gas are
then fluidly communicated to the catalyst included in the SCR
system to decompose substantially all of the NO.sub.x gases into
relatively harmless byproducts that are expelled out of the
aftertreatment system.
[0004] Aftertreatment systems generally include a reductant
insertion assembly for inserting a reductant into the SCR system.
Some reductant insertion assemblies use air provided by an air
supply system to assist in insertion of the reductant into the SCR
system, i.e., provide air-assisted insertion of the reductant. Such
air supply systems generally include a compressor and an external
air source (e.g., an air tank) to provide air-assisted insertion of
the reductant. Furthermore, such air supply systems may also
require a dedicated energy source, a filtration system, and/or an
oil separation system. These requirements increase the complexity
of such reductant insertion assemblies and therefore increase
manufacturing and maintenance costs.
SUMMARY
[0005] Embodiments described herein relate generally to systems and
methods for providing air-assisted reductant insertion in an
aftertreatment system, and in particular to a reductant insertion
assembly that includes an injector positioned on a SCR system for
inserting a reductant therein. A portion of compressed air from an
outlet of a compressor included in a turbocharger of the
aftertreatment system is rerouted to the injector and used in
air-assisted insertion of the reductant into the SCR system.
[0006] In one embodiment, an aftertreatment system structured to
decompose constituents of an exhaust produced by an engine having a
turbocharger including a turbine and a compressor coupled thereto,
includes: a selective catalytic reduction system; an injector
fluidly coupled to the selective catalytic reduction system and
structured to selectively insert a reductant into the selective
catalytic reduction system an intake conduit fluidly coupled to a
compressor outlet of the compressor and structured to deliver a
compressed air from the compressor to the engine; and an air
delivery line fluidly coupling the intake conduit to the injector,
the air delivery line being structured to deliver a portion of the
compressed air to the injector so as to facilitate air-assisted
insertion of the reductant by the injector.
[0007] In another embodiment, an aftertreatment system for an
internal combustion engine includes a turbocharger, an intake
conduit, an intake manifold, an air delivery line, and a housing.
The turbocharger includes a compressor and a turbine. The
compressor is configured to receive air from an air source. The
turbine is configured to receive exhaust from the internal
combustion engine. The intake conduit is configured to receive
compressed air from compressor. The intake manifold is configured
to receive a first portion of the compressed air from the intake
conduit and to provide the first portion of the compressed air to
the internal combustion engine. The air delivery line is configured
to receive a second portion of the compressed air from the intake
conduit separate from the intake manifold. The housing is
configured to receive the second portion of compressed air from the
air delivery line and to receive the exhaust from the turbine.
[0008] In yet another embodiment, an aftertreatment system for an
internal combustion engine having a turbocharger with a compressor
and a turbine, includes an intake conduit, an air delivery line,
and a housing. The intake conduit is configured to receive
compressed air. The air delivery line is coupled to the intake
conduit and structured such that a first portion of the compressed
air bypasses the air delivery line and a second portion of the
compressed air is diverted into the air delivery line. The housing
is structured to receive the second portion of compressed air from
the air delivery line and to separately receive exhaust.
[0009] It should be appreciated that all combinations of the
foregoing concepts and additional concepts discussed in greater
detail below (provided such concepts are not mutually inconsistent)
are contemplated as being part of the subject matter disclosed
herein. In particular, all combinations of claimed subject matter
appearing at the end of this disclosure are contemplated as being
part of the subject matter disclosed herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The foregoing and other features of the present disclosure
will become more fully apparent from the following description and
appended claims taken in conjunction with the accompanying
drawings. Understanding that these drawings depict only several
implementations in accordance with the disclosure and are therefore
not to be considered limiting of its scope, the disclosure will be
described with additional specificity and detail through use of the
accompanying drawings.
[0011] FIG. 1 is a schematic illustration of an aftertreatment
system, according to an embodiment.
[0012] FIG. 2 is a flow diagram of an example method for
air-assisted insertion of a reductant into a SCR system, according
to an embodiment.
[0013] Reference is made to the accompanying drawings throughout
the following detailed description. In the drawings, similar
symbols typically identify similar components unless context
dictates otherwise. The illustrative implementations described in
the detailed description, drawings, and claims are not meant to be
limiting. Other implementations may be utilized, and other changes
may be made, without departing from the spirit or scope of the
subject matter presented here. It will be readily understood that
the aspects of the present disclosure, as generally described
herein and illustrated in the figures, can be arranged,
substituted, combined, and designed in a wide variety of different
configurations, all of which are explicitly contemplated and made
part of this disclosure.
DETAILED DESCRIPTION
[0014] Embodiments described herein relate generally to systems and
methods for providing air-assisted reductant insertion in an
aftertreatment system, and in particular to a reductant insertion
assembly that includes an injector positioned on a SCR system for
inserting a reductant therein. A portion of compressed air from an
outlet of a compressor included in a turbocharger of the
aftertreatment system is rerouted to the injector and used in
air-assisted insertion of the reductant into the SCR system.
[0015] Aftertreatment systems generally include a reductant
insertion assembly for inserting a reductant into the SCR system.
Some reductant insertion assemblies use air provided by an air
supply system to assist in insertion of the reductant into the SCR
system, i.e., provide air-assisted insertion of the reductant. For
example, air may be mixed with the reductant, or air pulses may be
used to insert the reductant. Such air supply systems generally
include a compressor and an external air source (e.g., an air tank)
to provide air-assisted insertion of the reductant. Furthermore,
such air supply systems may also require a dedicated energy source,
a filtration and/or an oil separation system. This increases the
complexity of such reductant insertion assemblies and increases
manufacturing, as well as maintenance costs.
[0016] Various embodiments of the systems and methods described
herein may provide benefits including, for example: (1) using a
portion of compressed air from an outlet of a compressor included
in an aftertreatment system, thereby eliminating the use of a
dedicated air source or supply; (2) eliminating the use of a
dedicated energy source, filtration and/or oil separation system;
and (3) reducing energy consumption, manufacturing costs as well as
maintenance costs.
[0017] FIG. 1 is a schematic illustration of an aftertreatment
system 100, according to an embodiment. The aftertreatment system
100 is configured to receive an exhaust gas (e.g., a diesel exhaust
gas, etc.) from an engine 10 and reduce constituents of the exhaust
gas such as, for example, NO.sub.x gases, CO, hydrocarbons, etc.
The aftertreatment system 100 may comprise a reductant storage tank
110, a reductant insertion assembly 120, a turbocharger 130 and a
SCR system 150.
[0018] The engine 10 may include a diesel engine, a gasoline
engine, a biodiesel engine, a natural gas engine, a dual fuel
engine, or any other suitable engine that burns a fuel to produce
energy and generates an exhaust gas. The engine 10 comprises a
plurality of engine cylinders 12. While shown as including four
engine cylinders 12, in other embodiments, the engine 10 may
include any number of engine cylinders, for example 6, 8, 10, 12,
14, 16, 18, 20 or even more.
[0019] An intake manifold 20 is fluidly coupled to the engine 10
via a plurality of intake manifold conduits 22. The intake manifold
20 is structured to receive air from a compressor 134 of the
turbocharger 130, described below in further detail, and
communicate the air to each of the engine cylinders 12 via the
corresponding intake manifold conduit 22. Furthermore, an exhaust
manifold 30 is fluidly coupled to the engine 10 via a plurality of
exhaust manifold conduits 32. The exhaust manifold 30 is structured
to receive the exhaust gas from each of the engine cylinders 12 via
the corresponding exhaust manifold conduit 32 and communicate the
exhaust gas to the SCR system 150 via the turbocharger 130.
[0020] The SCR system 150 is positioned downstream of the
turbocharger 130 and comprises a housing 152 defining an internal
volume within which at least one catalyst 154 is positioned. The
housing 152 may be formed from a rigid, heat-resistant and
corrosion-resistant material, for example stainless steel, iron,
aluminum, metal, ceramic, or any other suitable material. The
housing 152 may have any suitable cross-section, for example
circular, square, rectangular, oval, elliptical, polygonal, or any
other suitable shape.
[0021] In some embodiments, the SCR system 150 may comprise a
selective catalytic reduction filter (SCRF) system, or any other
aftertreatment component, configured to decompose constituents of
the exhaust gas (e.g., NO.sub.x gases such as such nitrous oxide,
nitric oxide, nitrogen dioxide, etc.), flowing through the
aftertreatment system 100 in the presence of a reductant, as
described herein.
[0022] Although FIG. 1 shows only the catalyst 154 positioned
within the internal volume defined by the housing 152, in other
embodiments, a plurality of aftertreatment components may be
positioned within the internal volume defined by the housing 152 in
addition to the SCR system 150. Such aftertreatment components may
comprise, for example, filters (e.g., particulate matter filters,
catalyzed filters, etc.), oxidation catalysts (e.g., carbon
monoxide, hydrocarbons and/or ammonia oxidation catalysts), mixers,
baffle plates, heaters (e.g., regenerative heaters coupled to the
SCR system 150) or any other suitable aftertreatment component.
[0023] An inlet conduit 151 is fluidly coupled to an inlet of the
housing 152 and structured to receive exhaust gas from the engine
10. The inlet conduit 151 communicates the exhaust gas to an
internal volume defined by the housing 152. Furthermore, an outlet
conduit 153 may be coupled to an outlet of the housing 152 and
structured to expel treated exhaust gas into the environment. One
or more sensors may be positioned in the inlet conduit 151. Such
sensors may include a NO.sub.x sensor, for example a physical or
virtual NO.sub.x sensor, configured to determine an amount of
NO.sub.x gases included in the exhaust gas being emitted by the
engine 10.
[0024] In other embodiments, an oxygen sensor, an ammonia sensor, a
temperature sensor, a pressure sensor, or any other sensor may also
be positioned in the inlet conduit 151 so as to determine one or
more operational parameters of the exhaust gas flowing through the
aftertreatment system 100. One or more sensors may also be
positioned in the outlet conduit 153. The one or more sensors may
comprise a second NO.sub.x sensor configured to determine an amount
of NO.sub.x gases expelled into the environment after passing
through the SCR system 150, and/or a particulate matter sensor.
[0025] The catalyst 154 is formulated to decompose constituents of
an exhaust gas, for example NO.sub.x gases, flowing through the
aftertreatment system 100. The catalyst 154 is formulated to
selectively decompose constituents of the exhaust gas. Any suitable
catalyst can be used such as, for example, platinum, palladium,
rhodium, cerium, iron, manganese, copper, vanadium based catalyst,
any other suitable catalyst, or a combination thereof. The catalyst
154 can be disposed on a suitable substrate such as, for example, a
ceramic (e.g., cordierite) or metallic (e.g., kanthal) monolith
core which can, for example, define a honeycomb structure. A
washcoat can also be used as a carrier material for the catalyst
154. Such washcoat materials may comprise, for example, aluminum
oxide, titanium dioxide, silicon dioxide, any other suitable
washcoat material, or a combination thereof. The exhaust gas (e.g.,
diesel exhaust gas) can flow over and/or about the catalyst 154
such that any NO.sub.x gases included in the exhaust gas are
further reduced to yield an exhaust gas which is substantially free
of NO.sub.x gases.
[0026] An injector 122 may be positioned on a sidewall of housing
152 and is in fluid communication with the internal volume of the
housing 152, for example via a reductant insertion port defined on
a sidewall of the housing 152. In various embodiments, the injector
122 may comprise a dosing lance. The injector 122 is configured to
selectively insert a reductant into the internal volume defined by
the housing 152. The injector 122 may also include a nozzle 124
structured to shear the reductant into droplets so as to deliver
the reductant as a mist, a stream, a jet or as a conical spray cone
into the SCR system 150. Furthermore, the injector 122 may be
configured to insert the reductant droplets as a steady state
stream, or in a pulsed or transient sequence.
[0027] Furthermore, the injector 122 is structured to receive air,
as described herein so as to provide air-assisted insertion of the
reductant into the SCR system 150. For example, the injector 122
may also comprise a blending chamber structured to receive
pressurized reductant from a metering valve at a controllable rate.
The blending chamber may also be structured to receive air, for
example from the compressor 134 as described herein, so as to
deliver a combined flow of the air and the reductant to the SCR
system 150 through the nozzle 124.
[0028] The aftertreatment system 100 may also include a reductant
storage tank 110 and a reductant insertion assembly 120. The
reductant storage tank 110 is structured to store the reductant.
The reductant is formulated to facilitate decomposition of the
constituents of the exhaust gas (e.g., NO.sub.x gases included in
the exhaust gas). Any suitable reductant can be used. In some
embodiments, the exhaust gas comprises a diesel exhaust gas and the
reductant comprises a diesel exhaust fluid. For example, the diesel
exhaust fluid may comprise urea, an aqueous solution of urea, or
any other fluid that comprises ammonia, by-products, or any other
suitable diesel exhaust fluid (e.g., the diesel exhaust fluid
marketed under the name) ADBLUE.RTM.). In particular embodiments,
the reductant comprises an aqueous urea solution having a
particular ratio of urea to water. For example, the reductant may
comprise an aqueous urea solution including 32.5% by volume of urea
and 67.5% by volume of deionized water. In other embodiments, the
reductant may include 40% by volume of urea and 60% by volume of
deionized water.
[0029] A reductant insertion assembly 120 is fluidly coupled to the
reductant storage tank 110. The reductant insertion assembly 120 is
configured to selectively provide the reductant to the injector 122
from the reductant storage tank 110. The reductant insertion
assembly 120 may comprise one or more pumps having filter screens
(e.g., to prevent solid particles of the reductant or contaminants
from flowing into the pump) and/or valves (e.g., check valves)
positioned upstream thereof to receive reductant from the reductant
storage tank 110. In some embodiments, the pump may comprise a
diaphragm pump but any other suitable pump may be used such as, for
example, a centrifugal pump, a suction pump, etc.
[0030] The pump may be configured to pressurize the reductant so as
to provide the reductant to the injector 122 at a predetermined
pressure. Screens, check valves, pulsation dampers, or other
structures may also be positioned downstream of the pump to provide
the reductant to the injector 122. In various embodiments, the
reductant insertion assembly 120 may also comprise a bypass line
structured to provide a return path of the reductant from the pump
to the reductant storage tank 110
[0031] A valve (e.g., an orifice valve) may be provided in the
bypass line. The valve may be structured to allow the reductant to
pass therethrough to the reductant storage tank 110 if an operating
pressure of the reductant generated by the pump exceeds a
predetermined pressure so as to prevent over pressurizing of the
pump, the reductant delivery lines, or other components of the
reductant insertion assembly 120. In some embodiments, the bypass
line may be configured to allow the return of the reductant to the
reductant storage tank 110 during purging of the reductant
insertion assembly 120 (e.g., after the engine 10 is shut off).
[0032] The turbocharger 130 is positioned upstream of the SCR
system 150 and downstream of the exhaust manifold 30. The
turbocharger 130 comprises a turbine 132 and the compressor 134
operably coupled to the turbine 132 via a shaft 136. A turbine
inlet 133 of the turbine 132 is fluidly coupled to the exhaust
manifold 30 via an exhaust conduit 131, and structured to receive
the exhaust gas therefrom. The exhaust gas drives the turbine 132
and thereby the compressor 134 via the shaft 136. The inlet conduit
151 is also fluidly coupled to the turbine 132 and communicates the
exhaust gas therefrom to the SCR system 150.
[0033] The compressor 134 is fluidly coupled to an air inlet
conduit 162 and configured to receive air therefrom. An air filter
160 may be positioned upstream of the air inlet conduit 162 and
structured to remove particles such as, for example dust, soot,
carbon, inorganic particles, etc. from the air communicated to the
compressor 134. Driving of the compressor 134 by the turbine 132
may generate negative pressure in the air inlet conduit 162 which
draws air into the compressor 134. The compressor 134 is structured
to compress the air so as to produce compressed air at a first
pressure. The first pressure may be less than 1 bar.
[0034] An intake conduit 138 is fluidly coupled to a compressor
outlet 135 of the compressor 134 and structured to deliver the
compressed air from the compressor 134 to the engine 10 via the
intake manifold 20. An air delivery line 144 fluidly couples the
intake conduit 138 to the injector 122. The air delivery line 144
is structured to deliver a portion of the compressed air to the
injector 122 so as to facilitate air-assisted insertion of the
reductant by the injector 122 into the SCR system 150. Expanding
further, the air delivery line 144 includes a sideline (e.g., a
small tube, hose or conduit) which draws the first portion of the
compressed air from the intake conduit 138 and delivers to the
injector 122.
[0035] In various embodiments, the portion of the compressed air
may have a volume in a range of 0.01-8% (e.g., 0.01%, 0.02%, 1%,
1.1%, 7.9%, 7.99%, or 8% inclusive of all ranges and values
therebetween) of a total volume of the compressed air flowing
through the intake conduit 138. In one embodiment, where the first
pressure is greater than 2.5 bar, the portion of the compressed air
may have a volume of less than 1% of the total volume of the
compressed air flowing through the intake conduit 138.
[0036] In some embodiments, the portion of the compressed air may
have a volume in a range of 0.5-8% (e.g., 0.5%, 1%, 1.5%, 7%, 7.5%,
or 8% inclusive of all ranges and values therebetween) of a total
volume of the compressed air flowing through the intake conduit
138. In some embodiments, the portion of the compressed air may
have a volume in a range of 4-8% (e.g., 4%, 5%, 6%, 7%, or 8%
inclusive of all ranges and values therebetween) of the total
volume of the compressed air flowing through the intake conduit
138. In some embodiments, the air delivery line 144 may be fluidly
coupled to any portion of the turbocharger 130, for example the
turbine 132 (e.g., the turbine inlet 133 of the turbine 132) or the
compressor 132 and configured to receive the air therefrom.
[0037] In some embodiments, the air delivery line 144 delivers the
compressed air at the first pressure to the injector 122. In such
embodiments, the first pressure may be sufficient for the injector
122 to provide air-assisted reductant insertion into the SCR system
150. Furthermore, the nozzle 124 may be structured to shear the
reductant into reductant droplets using the compressed air at the
first pressure.
[0038] In other embodiments, a booster pump 146 (e.g., a positive
displacement pump, a centrifugal pump, a rotary lobe pump, a
progressive cavity pump, a rotary gear pump, a piston pump, a
diaphragm pump, a screw pump, a gear pump, a hydraulic pump, etc.)
may be positioned in the air delivery line 144 upstream of the
injector 122. The booster pump 146 may be configured to pressurize
the portion of the compressed air so as to generate pressurized air
having a second pressure greater than the first pressure, and
deliver the pressurized air to the injector 122. In particular
embodiments, the second pressure may be in a range of 1-3 bar
(e.g., 1 bar, 1.5 bar, 2 bar, 2.5 bar or 3 bar inclusive of all
ranges and values therebetween), and may correspond to a designed
pressure of the injector 122. Moreover, the nozzle 124 may be
structured to shear the reductant into reductant droplets using the
pressurized air at the second pressure.
[0039] In still other embodiments, a flow valve 148 may be
positioned in the air delivery line 144 upstream of the booster
pump 146. The flow valve 148 may include a check valve, a butterfly
valve, a disc valve, a clapper valve, a diaphragm valve or any
other suitable valve structured to control a flow rate of the
portion of the compressed air to the injector 122.
[0040] In this manner, the aftertreatment system 100 uses a portion
of the compressed air provided by the compressor 134 of the
turbocharger 130 for air-assisted insertion of the reductant
through the injector 122 into the SCR system 150. This eliminates
the use of a separate air supply system for providing air to the
injector 122, thereby reducing energy consumption, manufacturing
costs, and/or maintenance costs.
[0041] While FIG. 1 shows the aftertreatment system 100 as
including a single intake conduit 138, in other embodiments, the
aftertreatment system 100 or any other aftertreatment system
described herein may include a plurality of intake conduits (e.g.,
the intake conduit 138), and a plurality of exhaust conduits
fluidly coupled to the intake manifold 20 and the exhaust manifold
30, respectively. An SCR system (e.g., the SCR system 150) may be
fluidly coupled to each of the exhaust conduits, and an injector
(e.g., the injector 122) may be fluidly coupled to each of the
plurality of SCR systems or otherwise, the plurality of exhaust
conduits. Furthermore, each of the plurality of exhaust conduits
may have a turbocharger, (e.g., the turbocharger 130) including the
turbine and the compressor, fluidly coupled to a corresponding
exhaust conduit. In such embodiments, the aftertreatment system 100
may include a plurality of air delivery lines (e.g., the air
delivery lines 144) fluidly coupling a respective intake conduit to
a corresponding injector so as to provide air assisted insertion
thereto, as previously described herein. Furthermore, a booster
pump (e.g., the booster pump 146) and/or a flow valve (e.g., the
flow valve 148) may be provided in each of the plurality of air
delivery lines.
[0042] FIG. 2 is a schematic flow diagram of an example method 200
for providing air-assisted insertion of a reductant into an SCR
system (e.g., the SCR system 150) of an aftertreatment system
(e.g., the aftertreatment system 100), according to an embodiment.
The aftertreatment system 100 also includes a turbocharger (e.g.,
the turbocharger 130) comprising a turbine (e.g., the turbine 132)
and a compressor (e.g., the compressor 134). The compressor is
operably coupled to the turbine via a shaft (e.g., the shaft
136).
[0043] The method 200 comprises communicating an exhaust gas from
an exhaust manifold of an engine to the turbine so as to drive the
compressor, at 202. For example, the exhaust gas is communicated
from the exhaust manifold 30 fluidly coupled to the engine 10, to
the turbine 132 via the exhaust conduit 131. The exhaust gas drives
the turbine 132 and thereby the compressor 134 via the shaft 136.
The compressor 134 may receive air from the air inlet conduit 162
(e.g., after passing through the air filter 160) and compress the
air so as to generate compressed air.
[0044] The compressed air is communicated from the compressor to an
intake manifold of the engine via an intake conduit, at 204. For
example, the compressed air from the compressor 134 is communicated
to the intake manifold 20 via the intake conduit 138. A portion of
the compressed air is communicated to an air delivery line fluidly
coupling the intake conduit to an injector fluidly coupled to the
SCR system, at 206. For example, the portion of the compressed air
is communicated to the air delivery line 144 fluidly coupled at one
end to the intake conduit 138, and at an opposite end to the
injector 122.
[0045] In some embodiments, the method 200 also includes
pressurizing the portion of the compressed air so as to produce
pressurized air, at 208. For example, the booster pump 146 may be
positioned in the air delivery line 144, and structured to
pressurize the portion of the compressed air so as to generate the
pressurized air. The pressurized air is delivered to the injector
122 via the air delivery line 144. A reductant mixed with the
portion of the compressed air is communicated into the SCR system
via the injector, at 210. For example, the injector 122 inserts the
reductant mixed with the portion of the compressed air or the
pressurized air into the SCR system 150, thereby providing
air-assisted insertion of the reductant into the SCR system
150.
Experimental Results
[0046] A 3/8 inch air delivery line was used to fluidly couple an
air intake conduit to an injector. A booster pump was used to pump
compressed air at various air pressures to the injector via the air
delivery line. The injector included a nozzle having a SU46 body
and a SU29 orifice. Table 1 shows results of air flow and reductant
insertion rates at various air pressures, as well as the profile of
a DEF spray produced by the nozzle.
TABLE-US-00001 TABLE 1 Air flow rates, DEF insertion rates and DEF
spray profiles produce by the nozzle of the injector at various air
pressures. Air Pressure Air Flow [standard DEF Insertion Rate DEF
Spray [bar] liters per minute] [milliliters per second] Profile
0.689 98.1 ~1 Very fine mist 2.068 201.3 8.7 Mist with some wall
impacting 2.896 258.1 ~8.5 Some mist
[0047] It should be noted that the term "example" as used herein to
describe various embodiments is intended to indicate that such
embodiments are possible examples, representations, and/or
illustrations of possible embodiments (and such term is not
intended to connote that such embodiments are necessarily
extraordinary or superlative examples).
[0048] The terms "coupled" and the like as used herein mean the
joining of two members directly or indirectly to one another. Such
joining may be stationary (e.g., permanent) or moveable (e.g.,
removable or releasable). Such joining may be achieved with the two
members or the two members and any additional intermediate members
being integrally formed as a single unitary body with one another
or with the two members or the two members and any additional
intermediate members being attached to one another.
[0049] It is important to note that the construction and
arrangement of the various exemplary embodiments are illustrative
only. Although only a few embodiments have been described in detail
in this disclosure, those skilled in the art who review this
disclosure will readily appreciate that many modifications are
possible (e.g., variations in sizes, dimensions, structures, shapes
and proportions of the various elements; values of parameters,
mounting arrangements; use of materials, colors, orientations,
etc.) without materially departing from the novel teachings and
advantages of the subject matter described herein. Additionally, it
should be understood that features from one embodiment disclosed
herein may be combined with features of other embodiments disclosed
herein as one of ordinary skill in the art would understand. Other
substitutions, modifications, changes, and omissions may also be
made in the design, operating conditions, and arrangement of the
various exemplary embodiments without departing from the scope of
the present application.
[0050] While this specification contains many specific
implementation details, these should not be construed as
limitations on the scope of any embodiments or of what may be
claimed, but rather as descriptions of features specific to
particular implementations of particular embodiments. Certain
features described in this specification in the context of separate
implementations can also be implemented in combination in a single
implementation. Conversely, various features described in the
context of a single implementation can also be implemented in
multiple implementations separately or in any suitable
subcombination. Moreover, although features may be described above
as acting in certain combinations and even initially claimed as
such, one or more features from a claimed combination can in some
cases be excised from the combination, and the claimed combination
may be directed to a subcombination or variation of a
subcombination.
* * * * *