U.S. patent application number 14/602748 was filed with the patent office on 2015-05-14 for exhaust gas aftertreatment bypass system and methods.
This patent application is currently assigned to CUMMINS IP, INC.. The applicant listed for this patent is CUMMINS IP, INC.. Invention is credited to Gregory BENTLEY.
Application Number | 20150128571 14/602748 |
Document ID | / |
Family ID | 51486079 |
Filed Date | 2015-05-14 |
United States Patent
Application |
20150128571 |
Kind Code |
A1 |
BENTLEY; Gregory |
May 14, 2015 |
EXHAUST GAS AFTERTREATMENT BYPASS SYSTEM AND METHODS
Abstract
A method for protecting an exhaust aftertreatment system of an
internal combustion engine from deterioration by selectively
diverting exhaust gasses from the engine away from a component of
the exhaust aftertreatment system includes assessing a status of an
operating condition associated with a physical condition of the
component of the internal combustion engine. The status of the
operating condition is compared with a threshold value that
corresponds with deterioration of the physical condition of the
component. A valve upstream of the component is moved to a first
position to open a bypass fluid path directing exhaust gasses
around the component when the status of the operating condition
meets the threshold value to reduce deterioration of the component.
The valve is moved to a second position to close the bypass fluid
path thereby directing exhaust gasses to the component when the
status of the operating condition does not meet the threshold.
Inventors: |
BENTLEY; Gregory;
(Greenwood, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CUMMINS IP, INC. |
Columbus |
IN |
US |
|
|
Assignee: |
CUMMINS IP, INC.
Columbus
IN
|
Family ID: |
51486079 |
Appl. No.: |
14/602748 |
Filed: |
January 22, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13789345 |
Mar 7, 2013 |
|
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14602748 |
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Current U.S.
Class: |
60/274 ;
60/288 |
Current CPC
Class: |
F01N 2550/10 20130101;
F01N 2550/02 20130101; F01N 3/2066 20130101; F01N 13/017 20140601;
F01N 2410/02 20130101; F01N 2900/08 20130101; Y02T 10/12 20130101;
F01N 11/002 20130101; Y02T 10/24 20130101; F01N 9/00 20130101; F01N
2900/1404 20130101; Y02T 10/47 20130101; F01N 3/2053 20130101; F01N
11/00 20130101; Y02T 10/40 20130101 |
Class at
Publication: |
60/274 ;
60/288 |
International
Class: |
F01N 3/20 20060101
F01N003/20; F01N 11/00 20060101 F01N011/00 |
Claims
1. A method for protecting an exhaust aftertreatment system of an
internal combustion engine from deterioration by selectively
diverting exhaust gasses from the engine away from a component of
the exhaust aftertreatment system, comprising: assessing a status
of an operating condition associated with a physical condition of
the component of the internal combustion engine; comparing the
status of the operating condition with a threshold value that
corresponds with deterioration of the physical condition of the
component; moving a valve upstream of the component to a first
position to open a bypass fluid path directing exhaust gasses
around the component when the status of the operating condition
meets the threshold value to reduce deterioration of the component;
and moving the valve to a second position to close the bypass fluid
path thereby directing exhaust gasses to the component when the
status of the operating condition does not meet the threshold
value.
2. The method of claim 1, wherein the operating condition includes
a temperature of the exhaust gasses and the threshold value is an
upper temperature limit above which the component produces harmful
byproducts.
3. The method of claim 1, wherein the operating condition includes
a geographical location of the internal combustion engine and the
threshold value includes geographical locations that do not require
emissions controls for internal combustion engines.
4. The method of claim 1, wherein the operating condition includes
a chemical formulation of fuel used by the internal combustion
engine and the threshold value includes chemicals that deteriorate
the component.
5. The method of claim 4, wherein the chemicals that deteriorate
the component include sulfur.
6. The method of claim 1, further comprising: overriding the step
of moving the valve to the first position based on the threshold
comparison by manually moving the valve to the second position to
close the first fluid path and open the second fluid path to bypass
the exhaust aftertreatment device.
7. The method of claim 1, wherein the component is selected from
the group consisting of: a selective catalytic reducer (SCR), an
SCR coated filter, a diesel oxidation catalyst (DOC), a diesel
particulate filter (DPF), and combinations thereof.
8. A method for protecting an exhaust aftertreatment system of an
internal combustion engine from deterioration by selectively
diverting exhaust gasses from the engine away from a selective
catalyst reducer (SCR) component of the exhaust aftertreatment
system, comprising: assessing a status of an operating condition
associated with a physical condition of the SCR component of the
internal combustion engine; comparing the status of the operating
condition with a threshold value that corresponds with
deterioration of the physical condition of the SCR component, the
operation condition and threshold value including at least one of:
a temperature of the exhaust gasses compared to a higher
temperature threshold of the exhaust gasses above which the SCR
component produces harmful byproducts, fuel chemistry compared to
an upper threshold limit of sulfur content above which the sulfur
deteriorates the SCR component, or a geographical position of the
internal combustion engine compared to geographical locations that
do not require emissions controls for internal combustion engines;
moving a valve upstream of the component to a first position to
open a bypass fluid path directing exhaust gasses around the
component when the status of the operating condition meets the
threshold value to reduce deterioration of the SCR component; and
moving the valve to a second position to close the bypass fluid
path thereby directing exhaust gasses to the SCR component when the
status of the operating condition does not meet the threshold
value.
9. An apparatus for bypassing an exhaust aftertreatment device of
an internal combustion engine to protect a selective catalytic
reducer (SCR) component of the exhaust aftertreatment device from
deterioration, the apparatus comprising: a flow control valve
operable to open and close a bypass fluid path wherein exhaust
gasses from the engine bypass the exhaust after treatment device
when the valve is in the open position and the exhaust gasses flow
through the exhaust aftertreatment device when the valve is in the
closed position; a sampling module that samples an operating
condition of the internal combustion engine that is associated with
a physical condition of the SCR component; a comparison module that
compares the operating condition with a threshold value that
corresponds with deterioration of the physical condition of the SCR
component; and a control module that operates the flow control
valve to open the bypass fluid path if the operating condition does
not meet the threshold condition and to close the bypass fluid path
if the operating condition meets the threshold condition.
10. The apparatus of claim 9, wherein the sampling module samples a
temperature of the exhaust gasses and the comparison module
compares the temperature of the exhaust gasses to an upper
temperature limit above which the SCR component produces harmful
oxidation byproducts.
11. The apparatus of claim 9, wherein the sampling module samples a
geographical location of the internal combustion engine and the
threshold value includes geographical locations that do not require
emissions controls for internal combustion engines.
12. The apparatus of claim 9, wherein the sampling module samples a
chemical formulation of fuel used by the internal combustion engine
and the threshold value includes chemicals that deteriorate the
component.
13. The apparatus of claim 12, wherein the chemicals that
deteriorate the component include sulfur.
14. The apparatus of claim 9, further comprising: a user interface
associated with the control module configured to accept user input
to override the control module control of the flow control valve
and manually open the valve to the bypass fluid path to bypass the
exhaust aftertreatment device.
15. An internal combustion engine system, comprising: an internal
combustion engine; an exhaust aftertreatment system including a
selective catalyst reducer (SCR) component in exhaust receiving
communication with the internal combustion engine; and a bypass
system operatively associated with the exhaust aftertreatment
system operable to bypass the SCR component when an operating
condition of the internal combustion engine that corresponds with
deterioration of a physical condition of the SCR component is
detected.
16. The system of claim 15, the bypass system further comprising: a
flow control valve operable to open and close a bypass fluid path
wherein exhaust gasses from the engine bypass the exhaust after
treatment device when the valve is in the open position and the
exhaust gasses flow through the exhaust aftertreatment device when
the valve is in the closed position; and a controller that
determines whether the flow control valve is open to the bypass
fluid path by sampling the operating condition of the internal
combustion engine that is associated with the physical condition of
the SCR component and comparing the sample of the operating
condition with a threshold value that corresponds with
deterioration of the physical condition of the SCR component.
17. The system of claim 16, wherein the operating condition and
threshold value include at least one of: a temperature of the
exhaust gasses compared to a higher temperature threshold of the
exhaust gasses above which the SCR component produces harmful
byproducts; fuel chemistry compared to an upper threshold limit of
sulfur content above which the sulfur deteriorates the SCR; or a
geographical position of the internal combustion engine compared to
geographical locations that do not require emissions controls for
internal combustion engines.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 13/789,345, entitled "Exhaust Gas Aftertreatment Bypass
System and Methods," filed Mar. 7, 2013, the disclosure of which is
hereby incorporated herein by reference in its entirety.
FIELD
[0002] This disclosure relates generally to exhaust aftertreatment
systems for internal combustion engines, and more particularly to a
bypass system and method for protecting exhaust aftertreatment
devices from harmful environmental or operating conditions.
BACKGROUND
[0003] Exhaust aftertreatment systems include components used to
process exhaust gasses produced by an internal combustion engine
for the purpose of reducing harmful exhaust emissions. Some
aftertreatment system components, such as diesel oxidation
catalysts (DOC) and selective catalytic reduction (SCR) catalysts,
use catalytic materials to chemically convert potentially harmful
exhaust emissions into other less harmful emission products. Such
catalyst-based exhaust aftertreatment system components are
desirable for their ability to efficiently control emissions.
Unfortunately, some catalyst-based exhaust aftertreatment system
components are also susceptible to damage from adverse operational
and environmental conditions
[0004] For example, many components have an acceptable operating
temperature range. Exceeding the upper limits of the temperature
range can result in release of undesirable oxides, such as
pentoxide being released from a Vanadium-based catalyst. On the
other hand, operating at temperatures below the lower limits of the
temperature range can result in unburned hydrocarbon being trapped
or absorbed in the catalyst. Significant quantities of unburned
hydrocarbon can become combustible, and pose a threat to
aftertreatment hardware and the environment, due to uncontrolled
thermal events
[0005] Another potential hazard to catalyst-based exhaust
aftertreatment system components is the use of high sulfur-content
fuels. Many of the catalysts used in exhaust aftertreatment systems
include catalytic materials capable of oxidizing sulfur.
Consequently, due to sulfur poisoning, fuels having high sulfur
content can overwhelm and deactivate a catalyst configured to
oxidize other emissions components.
[0006] Engine failures are yet another hazard to the components of
exhaust aftertreatment systems. A bearing seal failure, for
instance, might release oil into the exhaust line that could damage
the components of an exhaust aftertreatment system.
SUMMARY
[0007] The subject matter of the present application has been
developed in response to the present state of the art, and in
particular, in response to the problems and needs in exhaust
aftertreatment art that have not yet been fully solved by currently
available exhaust aftertreatment systems. For example, the
inventors of the subject matter of the present application have
recognized that, given the high costs of exhaust aftertreatment
systems, it would be advantageous to have a bypass system that
would protect the aftertreatment components from operational and
environmental hazards that might cause damage to the components.
Additionally, the inventors of the subject matter of the present
application have recognized that a control system and methodology
for bypassing one or more components of an exhaust aftertreatment
system would extend the service life of the components when
operational or environmental hazards threaten the components.
[0008] Accordingly, in one embodiment, the subject matter of the
present application has been developed to provide a method for
protecting an exhaust aftertreatment system of an internal
combustion engine from deterioration by selectively diverting
exhaust gasses from the engine away from a component of the exhaust
aftertreatment system. The method includes assessing a status of an
operating condition associated with a physical condition of the
component of the internal combustion engine. The status of the
operating condition is compared with a threshold value that
corresponds with deterioration of the physical condition of the
component. A valve upstream of the component is moved to a first
position to open a bypass fluid path directing exhaust gasses
around the component when the status of the operating condition
meets the threshold value to reduce deterioration of the component.
The valve is moved to a second position to close the bypass fluid
path thereby directing exhaust gasses to the component when the
status of the operating condition does not meet the threshold
value.
[0009] In one implementation of the method, assessing the status of
the operating condition includes assessing a temperature of the
exhaust gasses and comparing the temperature to a lower temperature
threshold value below which the exhaust gasses include a
predetermined level of unburned hydrocarbons.
[0010] In another implementation, assessing the status of the
operating condition includes assessing a temperature of the exhaust
gasses and comparing the temperature to an upper temperature
threshold value above which the component degrades and produces
harmful byproducts, such as pentoxide.
[0011] In another implementation of the method, assessing the
status of the operating condition includes assessing a geographical
location of the internal combustion engine and comparing the
geographical location to a threshold value includes comparing the
geographical location of the engine to geographical locations that
do not require emissions controls for internal combustion
engines.
[0012] In yet another implementation of the method, assessing the
status of the operating condition includes assessing a chemical
formulation of fuel used by the internal combustion engine and
comparing fuel chemistry to a threshold value includes comparing
the fuel chemistry to chemicals that deteriorate the component,
such as sulfur.
[0013] The step of moving the valve to the first position based on
the threshold comparison can also be overridden by a user by
manually moving the valve to the second position to close the first
fluid path and open the second fluid path to bypass the exhaust
aftertreatment device.
[0014] Additionally, according to another embodiment, the subject
matter of the present application has been developed to provide an
apparatus for bypassing an exhaust aftertreatment device of an
internal combustion engine to protect a selective catalytic reducer
or reduction (SCR) component of the exhaust aftertreatment device
from deterioration. The apparatus includes a flow control valve
operable to open and close a bypass fluid path wherein exhaust
gasses from the engine bypass the exhaust after treatment device
when the valve is in the open position and the exhaust gasses flow
through the exhaust aftertreatment device when the valve is in the
closed position. A sampling module samples an operating condition
of the internal combustion engine that is associated with a
physical condition of the SCR component. A comparison module
compares the operating condition with a threshold value that
corresponds with deterioration of the physical condition of the SCR
component. A control module operates the flow control valve to open
the bypass fluid path if the operating condition does not meet the
threshold condition and to close the bypass fluid path if the
operating condition meets the threshold condition.
[0015] In one implementation of the apparatus a user interface is
associated with the control module. The user interface is
configured to accept user input to override the control module
control of the flow control valve and manually open the valve to
the bypass fluid path to bypass the exhaust aftertreatment
device.
[0016] In one embodiment of an internal combustion engine, the
engine includes an exhaust aftertreatment system including a SCR
component in exhaust receiving communication with the internal
combustion engine. A bypass system is operatively associated with
the exhaust aftertreatment system and operates to bypass the SCR
component when an operating condition of the internal combustion
engine that corresponds with deterioration of a physical condition
of the SCR component is detected.
[0017] In one implementation, the bypass system includes a flow
control valve operable to open and close a bypass fluid path with
exhaust gasses from the engine bypassing the exhaust after
treatment device when the valve is in the open position and the
exhaust gasses flow through the exhaust aftertreatment device when
the valve is in the closed position. The bypass system also
includes a controller that determines whether the flow control
valve is open to the bypass fluid path by sampling the operating
condition of the internal combustion engine that is associated with
the physical condition of the SCR component. The controller
compares the sampling of the operating condition with a threshold
value that corresponds with deterioration of the physical condition
of the SCR component.
[0018] The described features, structures, advantages, and/or
characteristics of the subject matter of the present disclosure may
be combined in any suitable manner in one or more embodiments
and/or implementations. In the following description, numerous
specific details are provided to impart a thorough understanding of
embodiments of the subject matter of the present disclosure. One
skilled in the relevant art will recognize that the subject matter
of the present disclosure may be practiced without one or more of
the specific features, details, components, materials, and/or
methods of a particular embodiment or implementation. In other
instances, additional features and advantages may be recognized in
certain embodiments and/or implementations that may not be present
in all embodiments or implementations. Further, in some instances,
well-known structures, materials, or operations are not shown or
described in detail to avoid obscuring aspects of the subject
matter of the present disclosure. The features and advantages of
the subject matter of the present disclosure will become more fully
apparent from the following description and appended claims, or may
be learned by the practice of the subject matter as set forth
hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order that the advantages of the subject matter may be
more readily understood, a more particular description of the
subject matter briefly described above will be rendered by
reference to specific embodiments that are illustrated in the
appended drawings. Understanding that these drawings depict only
typical embodiments of the subject matter and are not therefore to
be considered to be limiting of its scope, the subject matter will
be described and explained with additional specificity and detail
through the use of the drawings, in which:
[0020] FIG. 1 is schematic representation of an internal combustion
engine according to one embodiment of the present invention shown
with an exhaust aftertreatment bypass system coupled to an exhaust
system of the engine;
[0021] FIG. 2 is a schematic representation of an exhaust
aftertreatment bypass system according to one embodiment of the
present application, shown with a flow control valve directing flow
into a first fluid flow pathway;
[0022] FIG. 3 is a schematic representation of the bypass system of
FIG. 1 shown with the flow control valve directing flow into a
second fluid flow pathway;
[0023] FIG. 4 is a schematic block diagram of a controller of the
engine system of FIG. 1 in accordance with one representative
embodiment;
[0024] FIG. 5 is a schematic representation of an exhaust
aftertreatment bypass system according to another embodiment shown
with a flow control valve directing flow into a first fluid flow
pathway;
[0025] FIG. 6 is a schematic representation of the bypass system of
FIG. 3 shown with the flow control valve directing flow into a
second fluid flow pathway;
[0026] FIG. 7 is a schematic representation of an exhaust
aftertreatment bypass system according to another embodiment shown
with a flow control valve directing flow into a first fluid flow
pathway;
[0027] FIG. 8 is a schematic representation of the bypass device of
FIG. 5 shown with the flow control valve directing flow to a second
fluid flow pathway; and
[0028] FIG. 9 is a flow chart of a method for protecting an exhaust
aftertreatment device of an internal combustion engine system using
a bypass device in accordance with another embodiment of the
present application.
DETAILED DESCRIPTION
[0029] Reference throughout this specification to "one embodiment,"
"an embodiment," or similar language means that a particular
feature, structure, or characteristic described in connection with
the embodiment is included in at least one embodiment of the
present disclosure. Appearances of the phrases "in one embodiment,"
"in an embodiment," and similar language throughout this
specification may, but do not necessarily, all refer to the same
embodiment. Similarly, the use of the term "implementation" means
an implementation having a particular feature, structure, or
characteristic described in connection with one or more embodiments
of the present disclosure, however, absent an express correlation
to indicate otherwise, an implementation may be associated with one
or more embodiments.
[0030] Referring to FIG. 1, according to one embodiment, an
internal combustion engine 10 is shown with a bypass system 100
operatively associated with an exhaust aftertreatment system 20
that is in exhaust receiving communication with an exhaust manifold
12 of the internal combustion engine. The bypass system 100 is
configured to protect an exhaust aftertreatment component 22 from
potentially harmful operational and environmental conditions.
[0031] Generally, the bypass system 100 forms part of the exhaust
aftertreatment system 20, which is configured to reduce harmful
emissions in exhaust gasses generated by the internal combustion
engine 10. The exhaust aftertreatment system 20 includes one or
more components (e.g., the exhaust aftertreatment component 22)
configured to treat the exhaust gas in a particular way. The
exhaust aftertreatment system 20 also includes a main exhaust line
24 that provides exhaust gas to the one or more components prior to
being treated and directs exhaust gas away from the one or more
components after being treated. Accordingly, the main exhaust line
24 includes an upstream section 26 (e.g., upstream of the
components) and a downstream section 28 (e.g., downstream of the
components).
[0032] The components 22 that treat the exhaust gas include a
catalyst based treatment device that has a finite useful life based
on a catalytic chemical reaction with the exhaust gasses that
remove undesirable emissions from the exhaust gasses. Thus, the
more exposure the component 22 has to exhaust gasses, the more the
component will deteriorate and the shorter the component's useful
life will be. For this reason, it is desirable to control exposure
of the catalyst component 22 to the exhaust gasses to maximize the
useful life of the component. In the embodiments described herein,
the component 22 can include a selective catalytic reducer (SCR), a
selective catalytic reducer coated filter, a diesel oxidation
catalyst (DOC), a diesel particulate filter (DPF) with a selective
catalytic reducer, and the like.
[0033] Hence, to protect the component 22 from unnecessary exposure
to the exhaust gasses, the bypass system 100 includes a bypass line
110 with an inlet 112 fluidly coupleable to the upstream section 26
of the main exhaust line 24 and an outlet 114 fluidly coupleable to
the downstream section 28 of the main exhaust line. The bypass
system 100 also includes a flow control valve 120 that is operable
to divert exhaust gas flow around the exhaust aftertreatment
component 22 via the bypass line 110.
[0034] Referring to FIGS. 2 and 3, the bypass system 100 is shown
with the flow control valve 120 disposed in the upstream section 26
of the main exhaust line 24 proximate the inlet 112 to the bypass
line 110. The flow control valve 120 is actuatable between at least
first and second positions. As shown in FIG. 2, in the first
position (e.g., closed position), the flow control valve 120
defines a first fluid pathway extending from the upstream section
26 of the main exhaust line 24, through the flow control valve 120,
and into the aftertreatment component 22. In other words, the flow
control valve 120 in the closed position fluidly couples the
upstream section 26 of the main exhaust line 24 with the
aftertreatment component 22 such that exhaust gas, indicated by
directional arrow 32, flows from the upstream section 26 into the
aftertreatment component 22.
[0035] In contrast, as shown in FIG. 3, in the second position
(e.g., open position), the flow control valve 120 at least
partially blocks the first fluid pathway 32 to the aftertreatment
component 22 and defines a second fluid pathway extending from the
upstream section 26 of the main exhaust line 24, through the flow
control valve 120, around the aftertreatment component 22, and into
the downstream section 28 of the main exhaust line. In other words,
the flow control valve 120 in the open position fluidly couples the
upstream section 26 with the downstream section 28 while bypassing
the component 22 such that exhaust gas, indicated by directional
arrow 34, flows from the upstream section 26 directly into the
downstream section 28. Although not shown, the downstream section
28 of the main exhaust line may be coupled to a tailpipe of the
aftertreatment system.
[0036] The flow control valve 120 can be a gate valve 122, a ball
valve, a check valve a globe valve, a butterfly valve or other
similar type valve configured to direct the flow of gas based
fluids as known in the art. Additionally, the flow control valve
120 can have an actuator 124 that can move the valve between the
first position and the second position. The actuator 124 can
receive power from an electronic, pneumatic, or vacuum source.
[0037] A controller 130 may be designed to provide a performance
status to an on-board diagnostic system 150, or OBD 150. The OBD
150 may convey the status to a user such as a driver of the vehicle
containing the engine system 10 (FIG. 1), for example, with a light
or LED, an auditory signal or alarm, an analog gauge, a digital
readout, or the like. In the embodiment shown in FIGS. 2 and 3, the
controller 130 is in electronic communication with the flow control
valve 120 to control movement of the flow control valve 120 between
the first position and the second position.
[0038] Referring to FIG. 4, the controller 130 may include various
modules for controlling the operation of the exhaust aftertreatment
system 20. For example, the controller 130 may include one or more
modules for controlling the operation of the bypass system 100. As
embodied in FIGS. 2 and 3, the controller 130 includes a sampling
module 132, a comparison module 134, and a control module 136. The
control module 136 may control the ordinary operation of the bypass
system 100 and the more particularly the flow control valve 120 by
providing instruction to move the valve to either the first
position (e.g., closed position) 138 or the second position (e.g.,
open position) 140.
[0039] The sampling module 132 may, at desired times, sample an
operating condition of the internal combustion engine and the
aftertreatment component 22 that is associated with a physical
condition of the component 22. The sampling module can be a
physical sensor 52 (FIGS. 2 and 3), such as a thermocouple, a
virtual sensor, and the like. The sampling module 132 sends data
regarding the sampled condition to the comparison module 134 for
analysis.
[0040] The comparison module 134 may include a processor with logic
and instructions for comparing data from the sampling module 132
with a threshold value of the operating condition being sampled.
When the data from the sampling module 132 exceeds the threshold
value, the comparison module 134 informs the control module 136
which sends instructions 140 to the bypass system 100 to move the
valve 120 to the second position to bypass the aftertreatment
component 22. When the data from the sampling module 132 meets the
threshold value, the comparison module 134 informs the control
module 136 which sends instructions 138 to the bypass system 100 to
move the flow control valve 120 to the first position to allow the
exhaust gasses to flow through the aftertreatment component 22.
[0041] The controller 130 and its various modular components may
comprise processor, memory, and interface modules that may be
fabricated of semiconductor gates on one or more semiconductor
substrates. Each semiconductor substrate may be packaged in one or
more semiconductor devices mounted on circuit cards. Connections
between the modules may be through semiconductor metal layers,
substrate-to-substrate wiring, or circuit card traces or wires
connecting the semiconductor devices.
[0042] While not specifically illustrated and described with
reference to FIG. 4, the controller 130 can include additional
modules for conducting other control system functions. For example,
the controller can include a calculation module 142 and a reporting
module 144. The reporting module 144 can report the performance
status of the various modules in the controller 130 to a user via
an output device 146.
[0043] Additionally, the sampling module 132 can receive data from
multiple sources such as additional sensors 148 that sample other
operating conditions of the internal combustion engine that can
have a deteriorating effect on the aftertreatment component 22. For
example, the additional sensors 148 can sample an upper temperature
of the exhaust gasses, a lower temperature of the exhaust gasses, a
sulfur content of the fuel and exhaust gasses, and a global
positioning sensor (GPS) location of the engine during operation as
described below.
[0044] Although not shown in the Figures, other sensors (e.g. OBDII
sensors) located throughout the engine can be used to detect engine
performance problems that may adversely affect the SCR device, such
as a bearing seal failure that releases engine oil into the exhaust
system and the aftertreatment system. In such cases, the controller
can receive data from the engine sensors and turn the exhaust
stream to the bypass pathway in order to prevent damage to the
catalyst due to the engine performance problems.
[0045] Returning to FIG. 4, it will be appreciated that since the
exhaust gasses pass through and are treated by the exhaust
aftertreatment device 20, the physical properties of the exhaust
gasses can have a deteriorating effect on the exhaust
aftertreatment component 22 that can shorten the service life of
the aftertreatment component. For example, in catalyst based
exhaust aftertreatment devices such as SCR devices and SCR coated
filters, temperature of the exhaust gasses can result in
undesirable and even dangerous operating conditions for the SCR. If
the temperature of the exhaust gasses is too high, the catalyst in
the SCR device can produce undesirable oxides, such as pentoxide
from a vanadia based catalyst, which are produced at an
unacceptable rate at temperatures of around 550 degrees C.
Moreover, if the temperature exceeds an even higher threshold, a
vanadia based catalyst may be rendered useless. Other materials
used as catalysts in SCR devices, as known in the art, may also
degrade, produce harmful byproducts, or be rendered useless at
relatively high temperatures.
[0046] Consequently, the controller 132 includes a sensor 52, real
or virtual, that samples an upper temperature of the exhaust gasses
and a sampling module 132 that receives the sensor data. The
sampling module 132 sends the sampled temperature data to the
comparison module 134 where the data is compared to a high
temperature threshold. In one aspect, the high temperature
threshold is set at a temperature that is below the temperature
(e.g., 550 degrees C.) at which harmful byproducts, such as
pentoxides, may be produced at an unacceptable rate. In another
aspect, the high temperature threshold is set at a temperature that
is below the temperature at which the catalyst is rendered useless
by overheating. The comparison module 134 sends the comparison
results to the control module 136 to move the flow control valve
120 to the second position to bypass the exhaust aftertreatment
device 20 if the temperature exceeds the high temperature
threshold, thereby protecting the aftertreatment component 22 from
an undesirable production of harmful byproducts, such as
pentoxides, or damage from heat that may render the catalyst
useless.
[0047] On the other hand, if the exhaust gas temperatures are too
low, the exhaust gasses may contain an unacceptably high amount of
unburned hydrocarbons. Large quantities of unburned hydrocarbons
can overwhelm the catalyst such that the catalyst leaves residual
unburned hydrocarbons in the exhaust aftertreatment device 20.
Unburned hydrocarbons affect the efficiency of the catalyst and can
create an undesirable thermal event if enough accumulate within the
aftertreatment device 20. Therefore, a high unburned hydrocarbon
rate in the exhaust gas can result in a high unburned hydrocarbon
adsorption rate on the aftertreatment device 20. However, the
unburned hydrocarbon production rate may be, but is not
necessarily, equal to or proportional to the unburned hydrocarbon
device adsorption rate. Accordingly, in some implementations, the
sensed or estimated rate of accumulation or adsorption of unburned
hydrocarbons on the device 20 relative to a threshold can be
another factor controlling the operation of the exhaust bypass
valve.
[0048] Accordingly, the controller 130 includes a virtual or
physical sensor 52 to detect a low temperature of the exhaust
gasses which would indicate the presence of unburned hydrocarbons,
a virtual or physical sensor that samples for unburned hydrocarbon,
a virtual or physical sensor that samples for both low temperature
and for unburned hydrocarbons, or a virtual or physical that
determines an accumulation or adsorption rate of unburned
hydrocarbons on a catalyst or other aftertreatment device. The
controller also includes a sampling module 132 that receives the
data from the sensor. The sampling module 132 sends the sampled
temperature or unburned hydrocarbon data to the comparison module
134 where the data is compared to a low temperature threshold or an
unburned hydrocarbon threshold respectively. In one aspect, the low
temperature threshold is set at temperature at which hydrocarbons
are known to accumulate in the exhaust aftertreatment devices at an
unacceptable rate. In another aspect the unburned hydrocarbon
threshold is set at a level at which unburned hydrocarbons are
known to interfere with the catalyst material in the SCR. The
comparison module 134 sends the comparison results to the control
module 136 to move the flow control valve 120 to the second
position to bypass the exhaust aftertreatment device 20 if the
temperature falls below the low temperature threshold or the
unburned hydrocarbon rate exceeds the unburned hydrocarbon
threshold level, thereby protecting the aftertreatment component 22
from an undesirable buildup of unburned hydrocarbons.
[0049] Another physical property of the exhaust gasses that can
have a deteriorating effect on the exhaust aftertreatment component
22 is the presence of sulfur in the exhaust gasses. Some petroleum
based fuels have a high sulfur content. Unfortunately, exhaust from
high sulfur content fuels is also high in sulfur. Sulfur is also
oxidized by catalyst based exhaust aftertreatment devices and can
overwhelm the catalyst causing "sulfur poisoning" of the catalyst
wherein the catalyst is rendered useless.
[0050] Therefore, the controller 130 includes a sensor 148 that
samples the sulfur content of the exhaust gasses or the fuel and a
sampling module 132 that receives the sensor data. The sampling
module 132 sends the sampled sulfur content data to the comparison
module 134 where the data is compared to a sulfur content threshold
value. The comparison module 134 sends the comparison results to
the control module 136 to move the flow control valve 120 to the
second position to bypass the exhaust aftertreatment device 20 if
the sulfur content is above the sulfur content threshold, thereby
protecting the aftertreatment component 22 from an undesirable
buildup of sulfur within the aftertreatment device.
[0051] Yet another operating parameter that can have a
deteriorating effect on the exhaust aftertreatment component 22 is
operation of the exhaust aftertreatment device when control of
emissions is not needed. For example, some geographical areas of
the world do not have emissions regulations and being able to
bypass the exhaust aftertreatment device 20 when traveling in these
areas can extend the service life of the aftertreatment device.
[0052] Hence, the controller 130 includes a sensor 148 that samples
the geographic location of the internal combustion engine from a
global positioning sensor (GPS). The sampling module 132 sends the
GPS data to the comparison module 134 where the data is compared to
a GPS threshold value. The comparison module 134 sends the
comparison results to the control module 136 to move the flow
control valve 120. If the GPS location is found within a
geographical area that requires exhaust emission controls, then the
control module 136 sends a signal to the actuator 124 to move or
maintain the flow control valve 120 in the first position opening
the first fluid path 32 which directs flow through the after
treatment device 20. If the GPS location is in a geographical area
that does not require exhaust emissions control, the control module
136 sends a signal to move the flow control valve 120 to the second
position directing flow to the second flow path that bypasses the
exhaust aftertreatment device 20.
[0053] The flow control valve 120 can also be manually opened or
closed thereby overriding the controller 130. In one
implementation, the actuator 124 on the flow control valve can be
manually adjusted to override the controller 130 and move the flow
control valve 120 between the first position and the second
position. In another implementation, the controller 130 can receive
input data directly from a user through a user interface 56 (FIGS.
2 and 3). The user interface 56 can be a physical interface, such
as a keypad, or a virtual interface, as known in the art. Through
the user interface 56, the user can override the controller 130 and
direct the controller 130 to move the flow control valve 120 to the
first or second position as desired. In either case, the bypass
system 100 described herein provides a bypass pathway 110 that can
be selectively opened or closed by the user in order to protect and
preserve the life of the exhaust aftertreatment component 22.
[0054] Referring to FIGS. 5 and 6, a bypass system, indicated
generally at 300, is shown in accordance with another embodiment
for use in protecting an exhaust aftertreatment system 220 that is
in exhaust receiving communication with an exhaust manifold of an
internal combustion engine (not shown). The bypass system is
similar in many respects to the bypass system 100 described above
and shown in FIGS. 1-4. The bypass system 300 is configured to
protect the exhaust aftertreatment component 22 from potentially
harmful operational and environmental conditions.
[0055] The bypass system 300 forms part of the exhaust
aftertreatment system 220. The exhaust aftertreatment system 220
includes one or more components (e.g. the exhaust aftertreatment
component 22) configured to treat the exhaust gas in a particular
way. The components 22 that treat the exhaust gas include a
catalyst based treatment device, such as an SCR, SCR coated filter,
and the like, that have a finite useful life based on a catalytic
chemical reaction with the exhaust gasses that remove undesirable
emissions from the exhaust gasses.
[0056] Accordingly, to protect the component 22 from unnecessary
exposure to the exhaust gasses, the bypass system 300 includes a
housing 302 with an inlet 304 and an outlet 306. The aftertreatment
component 22 is disposed within the housing 302 and is configured
to receive exhaust gasses from the inlet 304 and to direct treated
gasses to the outlet 306.
[0057] A partition 308 is disposed within the housing 302 and
separates the housing into an inlet side 310 and an outlet side
312. The partition 308 restricts flow from the inlet side 310 to
the outlet side 312 such that flow of exhaust gasses passes through
the aftertreatment component 22 and to the outlet 306.
[0058] A flow control valve 320 is disposed in the housing 302
adjacent the inlet 304 upstream from the aftertreatment component
22. The flow control valve 320 is actuatable between at least first
and second positions. As shown in FIG. 5, in the first position
(e.g. closed position) the flow control valve 320 defines a first
fluid pathway extending from the inlet, through the flow control
valve and into the aftertreatment component 22. In other words,
when the flow control valve 320 is in the closed position, exhaust
gasses, indicated by directional arrow 332, flow through the valve
320 to the inlet side 310 of the housing 302, and into the
aftertreatment component 22.
[0059] In contrast, as shown in FIG. 6, in the second position
(e.g. open position) the flow control valve 320 at least partially
blocks the first fluid pathway 332 to the aftertreatment component
22 and defines a second fluid pathway extending from the inlet side
304 of the housing 302, around the aftertreatment component 22, and
into the outlet side 306 of the housing 302. In other words, the
flow control valve 320 in the open position fluidly couples the
inlet side 304 of the housing 302 with the outlet side 306 of the
housing 302 while bypassing the component 22 such that exhaust gas,
indicated by directional arrow 334, flows through the housing 302
without flowing through the aftertreatment component 22.
[0060] The bypass system 300 also includes the controller 130
described above and shown in detail in FIG. 4. The controller 130
is electronically coupled to the flow control valve 320 to control
movement of the flow control valve 320 between the first position
and the second position. In the embodiment shown in FIGS. 5 and 6,
the controller sends a signal to the actuator 124 to move the flow
control valve 320 to the desired position.
[0061] Referring to FIGS. 7 and 8, a bypass system, indicated
generally at 500, is shown in accordance with another embodiment
for use in protecting an exhaust aftertreatment system 220 that is
in exhaust receiving communication with an exhaust manifold of an
internal combustion engine (not shown). The bypass system is
similar in many respects to the bypass systems 100 and 300
described above and shown in FIGS. 1-6. The bypass system 500 is
configured to protect the exhaust aftertreatment component 22 from
potentially harmful operational and environmental conditions.
[0062] The bypass system 500 forms part of the exhaust
aftertreatment system 220. The exhaust aftertreatment system 220
includes one or more components (e.g. the exhaust aftertreatment
component 22) configured to treat the exhaust gas in a particular
way. The components 22 that treat the exhaust gas include a
catalyst based treatment device, such as an SCR, SCR coated filter,
and the like, that have a finite useful life based on a catalytic
chemical reaction with the exhaust gasses that remove undesirable
emissions from the exhaust gasses.
[0063] Accordingly, to protect the component 22 from unnecessary
exposure to the exhaust gasses, the bypass system 500 includes a
housing 502 with an inlet 504, a bypass outlet 506 and an
aftertreatment outlet 508. The aftertreatment component 22 is
disposed within the housing 502 and is configured to receive
exhaust gasses from the inlet 504 and to direct treated gasses to
the aftertreatment outlet 508.
[0064] A partition 510 is disposed within the housing 502 and
separates the housing into an inlet side 512 and an outlet side
514. The partition 510 restricts flow from the inlet side 512 to
the outlet side 514 such that flow of exhaust gasses passes through
the aftertreatment component 22 to the aftertreatment outlet 508
when the bypass outlet 506 is closed by the flow control valve
520.
[0065] The flow control valve 520 is disposed in the housing 502
adjacent the bypass outlet 506 upstream from the aftertreatment
component 22. The flow control valve 520 is actuatable between at
least first and second positions. As shown in FIG. 7, in the first
position (e.g. closed position) the flow control valve 520 closes
the bypass outlet 506 and defines a first fluid pathway extending
from the inlet 504 through the aftertreatment component 22 to the
aftertreatment outlet 508. In other words, when the flow control
valve 520 is in the closed position, exhaust gasses, indicated by
the directional arrow at 532, flow through into the inlet side of
the housing and into the aftertreatment component 22.
[0066] In contrast, as shown in FIG. 8, in the second position
(e.g. open position) the flow control valve 520 opens a bypass
exhaust pipe 550 that is downstream of the aftertreatment component
22 and defines a second fluid pathway extending from the inlet side
512 of the housing 502, past the aftertreatment component 22,
through the flow control valve 520 and into bypass exhaust pipe
550. In other words, in the open position the flow control valve
520 fluidly couples the inlet side 512 of the housing 502 with the
bypass exhaust pipe 550 such that exhaust gas, indicated by
directional arrow 534, flows through the housing 302 without
flowing through the aftertreatment component 22.
[0067] While the aftertreatment component 22 is not closed off by
the flow control valve 520 when the flow control valve is in the
second position, back pressure from the aftertreatment component 22
is higher in the bypass exhaust pipe 550 than in the aftertreatment
component 22. Consequently, exhaust gasses will tend to flow
through the flow control valve 550 and into the bypass exhaust pipe
550 instead of the aftertreatment component 22 since the exhaust
bypass pipe 550 is the path of least resistance for the exhaust
gasses. Thus, the second fluid pathway effectively bypasses the
aftertreatment component 22 when the flow control valve 520 is in
the second position.
[0068] The bypass system 500 also includes the controller 130
described above and shown in detail in FIG. 4. The controller 130
is electronically coupled to the flow control valve 520 to control
movement of the flow control valve 520 between the first position
and the second position. In the embodiment shown in FIGS. 7 and 8,
the controller 130 sends a signal to the actuator 124 to move the
flow control valve 520 to the desired position.
[0069] Referring to FIG. 9, a method for protecting an exhaust
aftertreatment system of an internal combustion engine, indicated
generally at 700, is shown in accordance with another embodiment of
the present invention. The method for protecting the exhaust
aftertreatment system 700 selectively diverts exhaust gasses from
the engine away from an aftertreatment component, such as a
Selective Catalyst Reducer, susceptible to deterioration from
potentially harmful operational and environmental conditions which
an internal combustion engine may encounter. The method includes
assessing a status of an operating condition associated with a
physical condition of the aftertreatment component of the internal
combustion engine, as shown at 702. The status of the operating
condition is compared with a threshold value that corresponds with
deterioration of the physical condition of the aftertreatment
component, shown at 704. If the operating condition exceeds the
threshold such that deterioration of the physical condition of the
aftertreatment component may occur, then a valve upstream of the
aftertreatment component is moved to a first position to open a
bypass fluid path that directs exhaust gasses around the component
to reduce deterioration of the component, shown at 706. If the
operating condition does not exceed the threshold, then the valve
is moved to a second position to close the bypass fluid path
thereby directing exhaust gasses to the aftertreatment component,
shown at 708.
[0070] In one aspect, the operating condition is a temperature of
the exhaust gasses which is compared to a lower temperature
threshold below which an unacceptable amount of unburned
hydrocarbons remains in the exhaust gasses. In another aspect, the
operating condition is a flow rate of unburned hydrocarbons in the
exhaust gasses which is compared to an upper threshold of an
unacceptable amount of unburned hydrocarbons in the exhaust gasses.
In yet another aspect, the operating is a temperature of the
exhaust gasses which is compared to a higher temperature threshold
of the exhaust gasses above which the Selective Catalyst Reducer
component produces harmful byproducts, such as pentoxides from a
vanadia based catalyst, or may otherwise be rendered useless by
overheating. In yet another aspect, the operating condition is a
chemical formulation of the fuel used by the internal combustion
engine which is compared to an upper threshold limit of sulfur
content above which the sulfur deteriorates the aftertreatment
component. In yet another aspect, the operational condition is a
geographical location of the internal combustion engine which is
compared to geographical locations that do not require emissions
controls for internal combustion engines.
[0071] If the operating condition exceeds the threshold such that
deterioration of the physical condition of the aftertreatment
component may occur, then a valve upstream of the aftertreatment
component is moved to a first position to open a bypass fluid path
that directs exhaust gasses around the component to reduce
deterioration of the component. If the operating condition does not
exceed the threshold, then the valve is moved to a second position
to close the bypass fluid path thereby directing exhaust gasses to
the aftertreatment component.
[0072] The step of moving a valve to a first position includes
receiving a signal from a controller that directs an actuator
associated with the valve to move the valve to the first position.
Similarly, the step of moving the valve to the second position 716
includes receiving a signal from the controller directing the
actuator to move the valve to the second position.
[0073] The step of moving the valve to the first position based on
the threshold comparison can be overridden by manually moving the
valve to the second position to close the first fluid path and open
the second fluid path to bypass the exhaust aftertreatment
device.
[0074] In the above description, certain terms may be used such as
"up," "down," "upper," "lower," "horizontal," "vertical," "left,"
"right," and the like. These terms are used, where applicable, to
provide some clarity of description when dealing with relative
relationships. But, these terms are not intended to imply absolute
relationships, positions, and/or orientations. For example, with
respect to an object, an "upper" surface can become a "lower"
surface simply by turning the object over. Nevertheless, it is
still the same object.
[0075] Additionally, instances in this specification where one
element is "coupled" to another element can include direct and
indirect coupling. Direct coupling can be defined as one element
coupled to and in some contact with another element. Indirect
coupling can be defined as coupling between two elements not in
direct contact with each other, but having one or more additional
elements between the coupled elements. Further, as used herein,
securing one element to another element can include direct securing
and indirect securing. Additionally, as used herein, "adjacent"
does not necessarily denote contact. For example, one element can
be adjacent another element without being in contact with that
element.
[0076] Reference throughout this specification to features,
advantages, or similar language does not imply that all of the
features and advantages that may be realized with the subject
matter of the present disclosure should be or are in any single
embodiment or implementation of the subject matter. Rather,
language referring to the features and advantages is understood to
mean that a specific feature, advantage, or characteristic
described in connection with an embodiment is included in at least
one embodiment of the subject matter of the present disclosure.
Discussion of the features and advantages, and similar language,
throughout this specification may, but do not necessarily, refer to
the same embodiment or implementation.
[0077] The present subject matter may be embodied in other specific
forms without departing from its spirit or essential
characteristics. The described embodiments are to be considered in
all respects only as illustrative and not restrictive. The scope of
the invention is, therefore, indicated by the appended claims
rather than by the foregoing description. All changes which come
within the meaning and range of equivalency of the claims are to be
embraced within their scope.
* * * * *