U.S. patent application number 12/015732 was filed with the patent office on 2009-07-23 for apparatus and control method for avoiding shock in diesel filters.
This patent application is currently assigned to BASF CATALYSTS LLC. Invention is credited to R. Samuel Boorse.
Application Number | 20090183499 12/015732 |
Document ID | / |
Family ID | 40433891 |
Filed Date | 2009-07-23 |
United States Patent
Application |
20090183499 |
Kind Code |
A1 |
Boorse; R. Samuel |
July 23, 2009 |
APPARATUS AND CONTROL METHOD FOR AVOIDING SHOCK IN DIESEL
FILTERS
Abstract
Provided are systems and/or methods that facilitate regeneration
of a soot filter for a diesel engine. The systems and/or methods
can include a bypass tube that connects a compressor side of a
turbocharger to an exhaust side of the turbocharger. Compressed air
from the turbocharger is introduced through the bypass tube into
the soot filter and reduced a soot filter temperature, thereby
mitigating the risk of thermal shock and over temperature
conditions in the soot filter.
Inventors: |
Boorse; R. Samuel;
(Skillman, NJ) |
Correspondence
Address: |
BASF CATALYSTS LLC
100 CAMPUS DRIVE
FLORHAM PARK
NJ
07932
US
|
Assignee: |
BASF CATALYSTS LLC
Florham Park
NJ
|
Family ID: |
40433891 |
Appl. No.: |
12/015732 |
Filed: |
January 17, 2008 |
Current U.S.
Class: |
60/295 ; 60/274;
60/297; 60/600 |
Current CPC
Class: |
F01N 2560/06 20130101;
Y02T 10/40 20130101; F01N 9/002 20130101; Y02T 10/12 20130101; Y02T
10/47 20130101; F02B 37/166 20130101; F01N 3/035 20130101; F02B
37/16 20130101; Y02T 10/144 20130101; F01N 13/009 20140601; F01N
2270/02 20130101; F01N 3/025 20130101 |
Class at
Publication: |
60/295 ; 60/600;
60/297; 60/274 |
International
Class: |
F01N 3/023 20060101
F01N003/023; F01N 3/00 20060101 F01N003/00 |
Claims
1. A system that facilitates regeneration of a soot filter for a
diesel engine, comprising: a turbocharger that is coupled to the
diesel engine and the soot filter; a motor that is coupled to a
turbocharger shaft; a bypass tube that connects a compressor side
of the turbocharger to an exhaust side of the turbocharger; and a
bypass valve and a controller that control an amount of compressed
air that flows through the bypass tube.
2. The system of claim 1, wherein the motor drives the turbocharger
independently of the diesel engine.
3. The system of claim 1, wherein the bypass tube comprises a
burner therein to increase a compressed air temperature.
4. The system of claim 1 further comprising a fuel injector that
provides fuel vapors in an exhaust gas of the diesel engine.
5. The system of claim 4, wherein the controller controls the
amount of compressed air by operating the motor, the bypass valve,
or combinations thereof.
6. The system of claim 1, wherein the soot filter is a ceramic soot
filter.
7. The system of claim 1, wherein the bypass tube connects the
compressor side to an exhaust conduit upstream of the exhaust side
of the turbocharger, to an exhaust pipe downstream of the
turbocharger, or a combination thereof.
8. The system of claim 1 further comprising a soot filter
temperature sensor, a turbo outlet temperature sensor, an engine
speed sensor, or combinations thereof.
9. A method that facilitates mitigating thermal shock in a soot
filter for a diesel engine, comprising: introducing compressed air
from a turbocharger into the soot filter by a bypass tube that
bypasses the compressed air around the diesel engine, the bypass
tube comprising a bypass valve; and controlling an amount of the
compressed air introduced into the soot filter to prevent a soot
filter temperature from exceeding a first pre-determined
temperature.
10. The method of claim 9, wherein the compressed air is introduced
by the bypass tube that connects the compressor side to an exhaust
conduit upstream of the exhaust side of the turbocharger, to an
exhaust pipe downstream of the turbocharger, or a combination
thereof.
11. The method of claim 9, wherein the amount of the compressed air
introduced into the soot filter is controlled based on a turbo
speed, turbo outlet temperature, turbo outlet pressure, engine
speed, soot filter temperature, soot filter back pressure, or
combinations thereof.
12. The method of claim 9, wherein the amount of the compressed air
introduced into the soot filter is controlled by operating the
bypass valve in the bypass tube, a motor that drives the
turbocharger, or combinations thereof.
13. The method of claim 9 further comprising increasing a
temperature of an exhaust gas that flows into the soot filter by
operating a motor that drives the turbocharger, a fuel injector
that injects fuel into the exhaust gas, a burner in the bypass
tube, or combinations thereof.
14. The method of claim 1, wherein the amount of the compressed air
introduced into the soot filter is controlled when the diesel
engine is in an idle mode or a low-demand mode, or when the diesel
engine stops.
15. A method that facilitates mitigating thermal shock in a soot
filter for a diesel engine, comprising: introducing compressed air
from a turbocharger into the soot filter by a bypass tube that is
around the diesel engine and that comprises a bypass valve; and
reducing a soot filter temperature by controlling an amount of the
compressed air introduced into the soot filter.
16. The method of claim 15, wherein the compressed air is
introduced by the bypass tube that connects the compressor side to
an exhaust conduit upstream of the exhaust side of the
turbocharger, to an exhaust pipe downstream of the turbocharger, or
a combination thereof.
17. The method of claim 15, wherein the amount of the compressed
air introduced into the soot filter is controlled based on a turbo
speed, turbo outlet temperature, turbo outlet pressure, engine
speed, soot filter temperature, soot filter back pressure, or
combinations thereof.
18. The method of claim 15, wherein the amount of the compressed
air introduced into the soot filter is controlled by operating the
bypass valve in the bypass tube, a motor that drives the
turbocharger or combinations thereof.
19. The method of claim 15 further comprising increasing a
temperature of an exhaust gas that flows into the soot filter by
operating a motor that drives the turbocharger, a fuel injector
that injects fuel into the exhaust gas, a burner in the bypass
tube, or combinations thereof.
20. The method of claim 15, wherein the amount of the compressed
air introduced into the soot filter is controlled when the diesel
engine is in an idle mode or a low-demand mode, or when the diesel
engine stops.
Description
BACKGROUND
[0001] Internal combustion engines used for both mobile and
stationary applications are subject to strict emission limits. One
approach to reducing emissions is to improve in-cylinder designs,
but these improvements have fallen short of meeting emissions
limits. Other approaches involve exhaust aftertreatment devices,
which have achieved significant emissions reductions.
[0002] Diesel engine exhaust is a heterogeneous mixture which
contains not only gaseous emissions such as carbon monoxide ("CO"),
unburned hydrocarbons ("HC") and nitrogen oxides ("NO.sub.x"), but
also contains phase materials (liquids and solids) which constitute
the so-called particulates or particulate matter. The total
particulate matter emissions of diesel exhaust are comprised of
three main components. One component is a solid, dry, solid
carbonaceous fraction or soot fraction. This dry carbonaceous
matter contributes to visible soot emissions commonly associated
with diesel exhaust.
[0003] A second component of the particulate matter is a soluble
organic fraction. The soluble organic fraction is sometimes
referred to as a volatile organic fraction. The volatile organic
fraction can exist in diesel exhaust either as a vapor or as an
aerosol (fine droplets of liquid condensate) depending on the
temperature of the diesel exhaust. These liquids arise from two
sources: (1) lubricating oil swept from the cylinder walls of the
engine each time the pistons go up and down; and (2) unburned or
partially burned diesel fuel.
[0004] A third component of the particulate matter is a sulfate
fraction. The sulfate fraction is formed from small quantities of
sulfur components present in the diesel fuel. Small proportions of
SO.sub.3 are formed during combustion of the diesel, which in turn
combines rapidly with water in the exhaust to form sulfuric acid.
The sulfuric acid collects as a condensed phase with the
particulates as an aerosol, or is adsorbed onto the other
particulate components, and thereby adds to the mass of total
particulate matter.
[0005] Diesel engine exhaust systems typically include soot filters
(e.g., particulate filters) and NO.sub.x reduction catalysts that
clean exhaust and reduce engine emissions. There are many known
filter structures that are effective in removing particulate matter
from diesel exhaust, such as honeycomb wall flow filters, wound or
packed fiber filters, open cell foams, sintered metal filters,
etc.
[0006] The filter is a physical structure for removing particles
from exhaust, and the accumulating particles increase a back
pressure from the filter on the engine. Thus the accumulating
particles have to be continuously or periodically burned out of the
filter to maintain an acceptable back pressure. For regeneration of
soot filters, elevated exhaust gas temperature can contribute to
increased regeneration activity. The accumulated particulate matter
is typically heated and oxidized, and removed in a regeneration
process before excessive levels have accumulated.
SUMMARY
[0007] The following presents a simplified summary of the
innovation in order to provide a basic understanding of some
aspects described herein. This summary is not an extensive overview
of the claimed subject matter. It is intended to neither identify
key or critical elements of the claimed subject matter nor
delineate the scope of the subject innovation. Its sole purpose is
to present some concepts of the claimed subject matter in a
simplified form as a prelude to the more detailed description that
is presented later.
[0008] The subject innovation relates to systems that facilitate
regeneration of a soot filter for a diesel engine. The systems can
include a bypass tube that connects a compressor side of a
turbocharger to an exhaust side of the turbocharger, and a bypass
valve and a controller that control an amount of compressed air
that flows through the bypass tube. The compressed air through the
bypass tube is introduced into the soot filter and reduced a soot
filter temperature, thereby mitigating the risk of thermal shock
and over temperature conditions in the soot filter. The compressed
air can be generated a motor that is coupled to the turbocharger
independently of the diesel engine.
[0009] The subject innovation also relates to methods that
facilitate mitigating thermal shock in a soot filter for a diesel
engine. In accordance with one aspect of the claimed subject
matter, the methods can involve introducing compressed air from a
turbocharger into the soot filter by a bypass tube that bypasses
the compressed air around the diesel engine, and controlling an
amount of the compressed air introduced into the soot filter to
prevent a soot filter temperature from exceeding a pre-determined
temperature. In accordance with another aspect of the claimed
subject matter, the methods can involve introducing compressed air
from a turbocharger into the soot filter by a bypass tube that is
around the diesel engine, and reducing a soot filter temperature by
controlling an amount of the compressed air introduced into the
soot filter.
[0010] The following description and the annexed drawings set forth
in detail certain illustrative aspects of the claimed subject
matter. These aspects are indicative, however, of but a few of the
various ways in which the principles of the innovation may be
employed and the claimed subject matter is intended to include all
such aspects and their equivalents. Other advantages and novel
features of the claimed subject matter will become apparent from
the following detailed description of the innovation when
considered in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a block diagram of an exemplary system that
facilitates regeneration of a soot filter for a diesel engine
having a turbocharger in accordance with one aspect of the
specification.
[0012] FIG. 2 is a block diagram of another exemplary system that
facilitates regeneration of a soot filter for a diesel engine
having a turbocharger in accordance with one aspect of the
specification.
[0013] FIG. 3 is a block diagram of another exemplary system that
facilitates regeneration of a soot filter for a diesel engine
having a turbocharger in accordance with one aspect of the
specification.
[0014] FIG. 4 is a flow diagram of an exemplary methodology for
mitigating thermal shock in a soot filter for a diesel engine in
accordance with one aspect of the specification.
[0015] FIG. 5 is a flow diagram of another exemplary methodology
for mitigating thermal shock in a soot filter for a diesel engine
in accordance with one aspect of the specification.
DETAILED DESCRIPTION
[0016] Diesel aftertreatment devices such as a soot filter can be
used for controlling diesel engine emissions. During diesel engine
operation, carbon particulates are produced as byproducts of
combustion. These materials are subsequently collected by the soot
filter. As the carbon particulates accumulate within these
aftertreatment devices, the aftertreatment devices must be
regenerated. This is accomplished by oxidizing the carbon
particulates held by these devices.
[0017] Regeneration of a soot filter is typically accomplished by
injecting fuel into engine cylinders by a fuel injector during
their exhaust cycle to form fuel vapors which are carried with
exhaust gas for burning in the soot filter device. Regeneration of
soot filters can be accomplished by after-injection, which involves
injecting low pressure diesel fuel directly into the exhaust
downstream of the engine. The regeneration may increase the
potential for thermal shock damages to the soot filter.
[0018] The subject innovation relates to systems, apparatuses,
and/or methods that mitigate (e.g., prevent or minimize) thermal
shock (e.g., over temperature or rapid cooling) of one or more
aftertreatment components (e.g., soot filter) for a diesel engine
under active regeneration. The systems, apparatuses and/or methods
can involve a turbocharger for a diesel engine that has a bypass
tube from a compressor side of the turbocharger to an exhaust side
of the turbocharger. The turbocharger can be connected to a motor,
thereby allowing independent driving of the turbocharger. When
desired, such as when the engine is subjected to "drop to idle"
conditions to regenerate soot filters, fresh air from the turbo
compressor can be bypassed around the engine and intake air can be
used to increase the gas flow through the exhaust system without
increasing engine speed.
[0019] The bypass tube can increase gas flow of compressed fresh
air through the soot filter, thereby reducing the temperature in
the soot filter. As a result, thermal shock and/or over temperature
conditions can be mitigated. The control of the valve, the motor,
and/or the fuel injector can facilitate mitigating thermal shock
and/or thermal excursions in soot filters by increasing fresh air
flow through the bypass tube and the through the soot filter
thereby reducing the temperature in the soot filter.
[0020] The control system can use inputs such as a turbo out
temperature, engine speed, regeneration control state, and turbo
speed to control the amount of power to the motor driving the
turbocharger, the position of the bypass valve, and the state of
the fuel injector being used to regenerate the system. The control
system can also use the turbo outlet temperature to determine
whether the fuel continues to be injected into the engine, diesel
oxidation catalyst (DOC) device, or regeneration burner to maintain
regeneration conditions in the filter. The fuel can be injected to
the components to avoid thermal shock of cold air bypassed around
the engine through the bypass tube from causing thermal shock as it
hits the already hot filter. The control system can also use a
small burner in the bypass tube to increase the bypass air
temperature to reduce to possibility of the thermal shock of cold
air bypassed around the engine.
[0021] The claimed subject matter is described with reference to
the drawings, wherein like reference numerals are used to refer to
like elements throughout. In the following description, for
purposes of explanation, numerous specific details are set forth in
order to provide a thorough understanding of the subject
innovation. It may be evident, however, that the claimed subject
matter may be practiced without these specific details. In other
instances, well-known structures and devices are shown in block
diagram form in order to facilitate describing the subject
innovation.
[0022] FIG. 1 is a block diagram of a system 100 for mitigating
thermal shock in aftertreatment devices such as a soot filter
device. The system 100 can include an internal combustion diesel
engine 102 that can be operatively coupled to a transmission (not
shown). The system 100 can involve a turbocharger 104 for a diesel
engine 102. The turbocharger 104 can have a bypass tube (e.g.,
pipe, conduit) 106 from a compressor side 108 of the turbocharger
104 to an exhaust side 110 of the turbocharger 104. The
turbocharger 104 can be connected to a motor 112, thereby allowing
independent driving of the turbocharger 104. The bypass tube 106
can have a valve 114 which allows the bypass to be open or
closed.
[0023] The engine 102 can include an intake manifold 116 fluidly
coupled to an intake conduit (e.g., pipe) 118 for receiving fresh
air. An exhaust manifold 120 of the engine 102 is fluidly coupled
to an exhaust gas conduit 122. Exhaust gas produced by the engine
102 exits through the exhaust manifold 120 and exhaust gas conduit
122 to the exhaust side 110 of the turbocharger 104.
[0024] Operation of the turbocharger 104 is conventional in that a
turbine wheel (not shown) housed within the exhaust side 110 of the
turbocharger 104 is responsive to the flow of exhaust gas through
the exhaust gas conduit 122 to rotationally drive the drive shaft
124 of the turbocharger 104 and thereby rotate a compressor wheel
(not shown) housed within the compressor side 108 of the
turbocharger 104. The rotational speed of the turbine wheel is
generally related to the flow rate of exhaust gas through the
exhaust gas conduit 122, and the mass flow rate of fresh air into
the intake conduit 118 is, in turn, proportional to the rotational
speed of the compressor wheel.
[0025] The motor 112 can be any suitable motor such as an electric
motor as long as the motor 112 can supply power to a turbocharger
shaft 124 and/or remove power from the shaft 124. The motor 112 can
be mechanically coupled to the turbocharger shaft 124 and can
receive an electrical control signal 126 from a controller 128.
When the motor 112 is operated, power is supplied to turbocharger
shaft 124, in addition to power supplied from the turbine wheel,
which increases turbocharger speed and forces additional air into
the intake conduit 118 and/or the bypass 106.
[0026] By including the motor 112 that drives the turbocharger 104,
the turbocharger 104 can generate the compressed air independently
of the engine state. For example, the turbocharger 104 generates
the compressed air by the motor 104 while the engine 102 is in an
idle mode or a low-demand mode or when the engine stops. As a
result, the soot filter regeneration can be performed when the
engine 102 is in an idle mode or a low-demand mode, or when the
engine stops.
[0027] An exhaust gas conduit 130 from the turbocharger 104 can be
fluidly coupled to an inlet of a DOC device 132. An outlet of the
diesel oxidation catalyst device 132 can be fluidly coupled via an
exhaust conduit 134 to an inlet of a soot filter 136 having an
outlet fluidly coupled to an exhaust conduit 138. It will be
appreciated that in some embodiments of the system 100, a NO.sub.x
aftertreatment device (not shown) may be included between the DOC
132 and the soot filter 136.
[0028] The bypass tube 106 can fluidly connect the compressor side
108 of the turbocharger 104 to the exhaust side 110. The bypass
tube 106 can bypass fresh air around the engine 102 and provide the
air from the compressor side 108 of the turbocharger 104 to the
exhaust side 110. The bypass tube 106 can go from the compressed
intake conduit 118 (e.g., just upstream of the intake manifold 116)
to the exhaust gas conduit 122 upstream of the exhaust side 110 of
the turbocharger 104. The bypass tube 106 can have a valve 114
which allows the bypass to be turned on and off. The bypass valve
114 can open and close the bypass 106.
[0029] The soot filter 136 can be any suitable filter including a
ceramic soot filter that collects carbon particulates in diesel
engine emissions produced as byproducts of combustion. The soot
filter 136 may be referred to as a particulate filter. As the
carbon particulates accumulate within the soot filter 136, the soot
filter can be regenerated by oxidizing the carbon particulates.
[0030] Regeneration of the soot filter 136 can be accomplished by
providing fuel vapors in an exhaust gas which are carried with the
exhaust gas for burning in the soot filter device 136. For example,
regeneration of the soot filter can be accomplished by injecting
fuel into engine cylinders of the engine 102 via a fuel injector
140 to form the fuel vapors. Although not shown in FIG. 1,
regeneration can be accomplished by injecting fuel into the exhaust
downstream of the engine or a regeneration burner. The details of
the regeneration and fuel injector are not critical to the practice
of the subject innovation. The details of the regeneration and fuel
injector can be found in, for example, U.S. Pat. No. 7,021,047,
which is hereby incorporated by reference.
[0031] The controller 128 is operatively coupled to one or more
sensors in the system. The controller 128 is also operatively
coupled to one or more components of the system. The controller 128
can receive information from the sensors and control the one or
more components based on the information generated by the sensors
for mitigating thermal shock (e.g., over temperature or rapid
cooling) of one or more aftertreatment components (e.g., soot
filter).
[0032] The sensor can generate information indicative of at least
one condition of one or more components of the system 100. Examples
of sensors include temperature sensors, pressure sensors, chemical
sensors, motion sensors, electrical signal sensors, digital
cameras, and other types of devices capable of rendering
measurements. Specific examples of sensors include turbo speed
sensors, turbo outlet temperature sensors, turbo outlet pressure
sensors, engine speed sensors, soot filter temperature sensors,
soot filter back pressure sensors, or the like. By way of example,
FIG. 1 illustrates turbo outlet temperature sensors 142, engine
speed sensors 144, and soot filter temperature sensors 146.
[0033] The controller 128 can change at least one condition of one
or more components of the system based on the information generated
by the sensors. For example, the controller 128 operates the motor
112, bypass valve 114, fuel injector 140, or the like by sending
control signals 126, 148, 150 to the motor 112, bypass valve 114,
fuel injector 140, or the like based on the information 152, 154,
156 from the turbo outlet temperature sensors 142, engine speed
sensors 144, soot filter temperature sensors 146, or the like. The
controller 128 can change the amount of power to the motor 112
driving the turbocharger 104, the position of the bypass valve 114,
the state of the fuel injector 140, or the like. In one embodiment,
the controller 128 increases the fresh air flow through the bypass
tube 106 to reduce the soot filter temperature by opening the
bypass valve 114, driving the motor 112, or the like. The intake
air from the turbo compressor 108 is bypassed around the engine 102
by the bypass tube 106 and the air can be used to increase the gas
flow through the exhaust system 132, 136 without increasing engine
speed, thereby reducing the soot filter temperature. Alternatively,
the controller 128 can reduce the air flow through the bypass tube
106 to increase the soot filter temperature by closing the bypass
valve 114, stopping the motor 112, or the like.
[0034] In one embodiment, the motor 112 functions to increase an
amount of air flow through the bypass tube 106, and to therefore
reduce the regeneration temperature in the soot filter 136.
Conversely, when the motor 123 is operated to remove power from the
shaft, the turbocharger speed is decreased, thereby reducing the
amount of combustion air entering into the bypass tube 116.
[0035] In another embodiment, the controller 128 uses inputs such
as turbo out temperature, engine speed, regeneration control state,
and turbo speed to control the amount of power to the motor 112,
the position of the bypass valve 114, and the state of the fuel
injector 140. The controller 128 can use a soot filter temperature
to determine how much power to apply to the motor 112 to drive the
turbocharger 104, how much the bypass valve 114 is opened or
closed, how much the fuel is injected by the injector 140, or the
like. The controller 128 can apply power to the motor 112 and/or
open the bypass valve 114 when the turbo outlet temperature exceeds
a first pre-determined temperature.
[0036] The controller 128 can change one or more conditions of one
or more components of the system 100 to mitigate thermal shock
and/or over temperature conditions of the soot filter under
regeneration of the soot filter at engine idle. For example, the
controller 128 changes one or more conditions of one or more
components of the system 100 to prevent the soot filter temperature
from exceeding a predetermined temperature. In one embodiment, the
controller 128 changes at least one condition of one or more
components of the system to prevent the soot filter temperature
from exceeding about 650 degrees Celsius. In another embodiment,
the controller 128 changes at least one condition of one or more
components of the system to prevent the soot filter temperature
from exceeding about 600 degrees Celsius. In yet another
embodiment, the controller 128 changes at least one condition of
one or more components of the system to prevent the soot filter
temperature from exceeding about 550 degrees Celsius.
[0037] In one embodiment, the subject innovation can increase an
exhaust gas temperature to prevent thermal shock of cold air
bypassed around the engine from causing thermal shock as it hits
the already hot filter (e.g., thermal shock due to rapid cooling).
The controller 128 can use a turbo outlet temperature to determine
whether the fuel should continue to be injected into the engine,
DOC, or regeneration burner to maintain regeneration conditions
(e.g., soot filter temperature) in the soot filter device 136. The
controller 128 operates the fuel injector 140 to inject fuel when
the turbo outlet temperature is below a second pre-determined
temperature. In another embodiment, the bypass tube 106 includes a
small burner (not shown) therein to increase the bypass air
temperature to reduce to possibility of the thermal shock.
[0038] The controller 128 can increase a temperature of the exhaust
gas from the turbocharger 104 by injecting fuel into the engine,
DOC, or regeneration burner and/or by operating the burner in the
bypass tube 106 to a second pre-determined temperature. In one
embodiment, the controller 128 increases the exhaust gas
temperature to about 200 degrees Celsius or more and 600 degrees
Celsius or less. In another embodiment, the controller 128
increases the exhaust gas temperature to about 300 degrees Celsius
or more and 550 degrees Celsius or less. In yet another embodiment,
the controller 128 increases the exhaust gas temperature to about
350 degrees Celsius or more and 500 degrees Celsius or less.
[0039] Regeneration can be performed at any suitable time.
Regeneration can be performed periodically at appropriate
intervals. In one embodiment, regeneration is performed when the
diesel engine 102 is in an idle mode or a low-demand mode.
Regeneration can be triggered shortly after the filter performance
falls to a pre-determined value during normal operation. After
extended operation of a number of hours, the soot/ash is build up
as a cake on the soot filter 136 and the engine exhaust back
pressure increases. In one embodiment, regeneration is
automatically performed when a specified back pressure is reached.
The regeneration can be done by using feedback signals such as an
exhaust back-pressure, elapsed time since previous regeneration,
detection of carbon accumulation, signals from diesel engine
parameters indicating a specific engine mode where conditions are
right to initiate the soot regeneration. In another embodiment,
regeneration can be performed manually.
[0040] FIG. 2 illustrates another exemplary system 200 that
facilitates regeneration of a soot filter for a diesel engine
having a turbocharger. The system 200 includes a diesel engine 202;
a turbocharger 204 that is coupled to the soot filter 206; a motor
208 that is coupled to a turbocharger shaft 210; a bypass tube 212
that connects a compressor side 214 of the turbocharger 204 to an
exhaust side 216; a bypass valve 218; and a controller 220 that
control an amount of compressed air that flows through the bypass
tube 212. The bypass tube 212 can fluidly connect the compressor
side 214 of the turbocharger to the exhaust side 216. The bypass
tube 212 can bypass fresh intake air around the engine 202 and
provide the air from the compressor side 214 of the turbocharger to
the exhaust side 216. The bypass tube 212 can go from the
compressed inlet side 214 (e.g., just upstream of the intake
manifold) to the exhaust gas conduit 222 downstream of the
turbocharger 204. In one embodiment, the bypass tube 212 includes a
small burner (not shown) therein to increase the bypass air
temperature to reduce to possibility of the thermal shock of cold
air to the soot filter 206. It is to be appreciated that the
turbocharger 204, the motor 208, the bypass valve 218, and the
controller 220 can be substantially similar to the turbocharger
104, the motor 112, the bypass valve 114, and the controller 128 as
described in connection with FIG. 1.
[0041] The engine 202 can include an intake manifold 224 fluidly
coupled to an intake conduit (e.g., pipe) 226 for receiving fresh
air from the compressor side 214 of the turbocharger 204. An
exhaust manifold 228 of the engine 202 is fluidly coupled to an
exhaust gas conduit 230. Exhaust gas produced by the engine 202
exits through the exhaust manifold 228 and exhaust gas conduit 230.
The exhaust gas then drives the drive shaft 210 of the turbocharger
204 and exits through an exhaust gas conduit 222.
[0042] The exhaust gas conduit 222 from the turbocharger 204 can be
fluidly coupled to an inlet of a DOC device 232. An outlet of the
diesel oxidation catalyst device 232 can be fluidly coupled via an
exhaust conduit 234 to an inlet of a soot filter 206 having an
outlet fluidly coupled to an exhaust conduit 236. It will be
appreciated that in some embodiments of the system 200, a NO.sub.x
aftertreatment device (not shown) may be included between the DOC
232 and the soot filter 206.
[0043] The controller 220 can change at least one condition of one
or more components of the system based on the information generated
by the sensor in the similar manner as described in connection with
FIG. 1. For example, the controller 220 operates the motor 208, the
bypass valve 218, a fuel injector 240, or the like by sending
control signals 242, 244, 246 to the motor 208, the bypass valve
218, the fuel injector 240, or the like based on the information
248, 250, 252 from the turbo outlet temperature sensors 254, engine
speed sensors 256, soot filter temperature sensors 258, or the
like. In one embodiment, the controller 220 increases the air flow
through the bypass tube 212 to reduce the soot filter temperature
by opening the bypass valve 218 and by driving the motor 208, or
the like. In another embodiment, the controller 220 increases a
temperature of the exhaust gas from the turbocharger 204 by
injecting fuel into the engine, DOC, or regeneration burner (not
shown) and/or by operating the bypass tube burner.
[0044] FIG. 3 illustrates another exemplary system 300 that
facilitates regeneration of a soot filter for a diesel engine
having a turbocharger. The system 300 includes a diesel engine 302;
a turbocharger 304 that is coupled to the soot filter 306; a motor
308 that is coupled to a turbocharger shaft 310; two bypass tubes
312, 314 that connect a compressor side 316 of the turbocharger 304
to an exhaust side 318; bypass valves 320, 322 in the bypass tubes
312, 314; and a controller 324 that control an amount of compressed
air that flows through the bypass tubes 312, 314. The bypass tubes
312, 314 can fluidly connect the compressor side 316 of the
turbocharger to the exhaust side 318. The bypass tubes 312, 314 can
bypass fresh intake air around the engine 302 and provide the air
from the compressor side 316 of the turbocharger to the exhaust
side 318. The bypass tubes 312, 314 can go from a compressed intake
conduit 326 (e.g., just upstream of the intake manifold 116) to an
exhaust gas conduit 328 upstream of the exhaust side 318 of the
turbocharger 304 and to an exhaust pipe 330 downstream of the
turbocharger 304.
[0045] The two bypass tubes 312, 314 can have a common intake. In
another embodiment, the two bypass tubes 312, 314 have separate
intakes, respectively (not shown). In one embodiment, at least one
of the bypass tubes 312, 314 include a small burner (not shown)
therein to increase the bypass air temperature to reduce to
possibility of the thermal shock of cold air to the soot filter
306.
[0046] It is to be appreciated that the turbocharger 304, the motor
308, the bypass valves 320, 322, and the controller 324 can be
substantially similar to the turbocharger 104, the motor 112, the
bypass valve 114, and the controller 128 as described in connection
with FIG. 1. The engine 302 can include an intake manifold 332
fluidly coupled to an intake conduit (e.g., pipe) 326 for receiving
fresh air from the compressor side 316 of the turbocharger 304. An
exhaust manifold 334 of the engine 302 is fluidly coupled to the
exhaust gas conduit 328 upstream of the exhaust side 318 of the
turbocharger 304. Exhaust gas produced by the engine 302 exits
through the exhaust manifold 334 and exhaust gas conduit 328. The
exhaust gas then drives the drive shaft 310 of the turbocharger 304
and exits through an exhaust gas pipe 330 downstream of the
turbocharger 304.
[0047] The exhaust gas pipe 330 from the turbocharger 304 can be
fluidly coupled to an inlet of a DOC device 336. An outlet of the
diesel oxidation catalyst device 336 can be fluidly coupled via an
exhaust conduit 338 to an inlet of a soot filter 306 having an
outlet fluidly coupled to an exhaust conduit 340. It will be
appreciated that in some embodiments of the system 300, a NO.sub.x
aftertreatment device (not shown) may be included between the DOC
and the soot filter.
[0048] The controller 324 can change at least one condition of one
or more components of the system based on information generated by
one or more sensors in the similar manner as described in
connection with FIG. 1. For example, the controller 324 operates
the motor 308, at least one of the two bypass valves 320, 322, a
fuel injector 342, or the like by sending control signals 344, 346,
348 to the motor 308, at least one of the two bypass valves 320,
322, the fuel injector 342, or the like based on the information
350, 352, 354 from the turbo outlet temperature sensors 356, engine
speed sensors 358, soot filter temperature sensors 360, or the
like. In one embodiment, the controller 324 increases the air flow
through at least one of the two bypass tubes 312, 314 to reduce the
soot filter temperature by opening at least one of the two bypass
valves 320, 322 and by driving the motor 308, or the like. In
another embodiment, the controller 324 increases a temperature of
the exhaust gas from the turbocharger 304 by injecting fuel into
the engine, DOC, or regeneration burner (not shown) and/or by
operating the bypass tube burner.
[0049] FIG. 4 illustrates an exemplary methodology 400 of
mitigating thermal shock in a soot filter for a diesel engine. At
402, compressed air is introduced from a turbocharger into the soot
filter by a bypass tube that bypasses the compressed air around the
diesel engine. At 404, an amount of the compressed air introduced
into the soot filter is controlled to prevent a soot filter
temperature from exceeding a first pre-determined temperature.
[0050] FIG. 5 illustrates another exemplary methodology 500 of
mitigating thermal shock in a soot filter for a diesel engine. At
502, compressed air is introduced from a turbocharger into the soot
filter by a bypass tube that is around the diesel engine. At 504, a
soot filter temperature is reduced by controlling an amount of the
compressed air introduced into the soot filter.
[0051] Although not shown in FIGS. 4 and 5, in one embodiment, the
bypass tube connects the compressor side to an exhaust gas conduit
upstream of the exhaust side of the turbocharger. In another
embodiment, the bypass tube connects the compressor side to an
exhaust pipe downstream of the turbocharger. In yet another
embodiment, the bypass tube connects the compressor side to both an
exhaust conduit upstream of the exhaust side of the turbocharger
and to an exhaust pipe downstream of the turbocharger.
[0052] In one embodiment, the amount of the compressed air
introduced into the soot filter is controlled based on a turbo
speed, turbo outlet temperature, turbo outlet pressure, engine
speed, soot filter temperature, soot filter back pressure,
combinations thereof. The amount of the compressed air introduced
into the soot filter can be controlled by operating a bypass valve
in the bypass tube, a motor that drives the turbocharger, a fuel
injector that injects fuel into an exhaust gas, or combinations
thereof.
[0053] In another embodiment, the methodologies in FIGS. 4 and 5
further involve increasing a temperature of a gas exhaust that
flows into the soot filter by operating a motor that drives the
turbocharger, a fuel injector that injects fuel into the exhaust
gas, a burner in the bypass tube, or combinations thereof. By
increasing the exhaust gas temperature, the methodologies can
prevent thermal shock of cold air bypassed around the engine from
causing thermal shock as it hits the already hot filter.
[0054] The claimed subject matter can be implemented on existing
engine systems that can be used for both mobile and stationary
applications. Examples of engine systems include automobiles, farm
tractors, stationary machinery, portable machinery including
generators, snow-blowers, lawn mowers, small watercraft engines,
and the like, construction vehicles and machinery such as diggers,
front end loaders, trucks, cranes, fork lifts, pavers, graders,
bulldozers and the like, boats, ships, helicopters, aircraft,
trains, motorbikes, motorcycles, all-terrain vehicles, and related
transportation machinery.
[0055] As utilized herein, terms "controller," "component,"
"system," "device," and the like can be intended to refer to a
computer-related entity, either hardware, software (e.g., in
execution), and/or firmware. For example, a component can be a
process running on a processor, an object, an executable, a
program, a function, a library, a subroutine, and/or a computer or
a combination of software and hardware. By way of illustration,
both an application running on a computer that is mounted on a
vehicle and the computer can be a controller or a component. One or
more components can reside within a process and a component can be
localized on one computer and/or distributed between two or more
computers.
[0056] Furthermore, the claimed subject matter may be implemented
as a method, apparatus, or article of manufacture using standard
programming and/or engineering techniques to produce software,
firmware, hardware, or any combination thereof to control a
computer to implement the disclosed subject matter. The term
"article of manufacture" as used herein is intended to encompass a
computer program accessible from any computer-readable device,
carrier, or media. For example, computer readable media can include
but are not limited to magnetic storage devices (e.g., hard disk,
floppy disk, magnetic strips, or the like), optical disks (e.g.,
compact disk (CD), digital versatile disk (DVD), or the like),
smart cards, and flash memory devices (e.g., card, stick, key
drive, or the like). Additionally it should be appreciated that a
carrier wave can be employed to carry computer-readable electronic
data such as those used in transmitting and receiving electronic
mail or in accessing a network such as the Internet or a local area
network (LAN). Of course, those skilled in the art will recognize
many modifications may be made to this configuration without
departing from the scope or spirit of the claimed subject matter.
Moreover, the word "exemplary" is used herein to mean serving as an
example, instance, or illustration. Any aspect or design described
herein as "exemplary" is not necessarily to be construed as
preferred or advantageous over other aspects or designs.
[0057] While the claimed subject matter has been described above in
the general context of computer-executable instructions of a
computer program that runs on a local computer and/or remote
computer, those skilled in the art will recognize that the subject
innovation also may be implemented in combination with other
program modules. Generally, program modules include routines,
programs, components, data structures, etc., that perform
particular tasks and/or implement particular abstract data
types.
[0058] Moreover, those skilled in the art will appreciate that the
inventive methods may be practiced with other computer system
configurations, including single-processor or multi-processor
computer systems, minicomputers, mainframe computers, as well as
personal computers, hand-held computing devices,
microprocessor-based and/or programmable consumer electronics, and
the like, each of which may operatively communicate with one or
more associated devices. The illustrated aspects of the claimed
subject matter may also be practiced in distributed computing
environments where certain tasks are performed by remote processing
devices that are linked through a communications network. However,
some, if not all, aspects of the subject innovation may be
practiced on stand-alone computers. In a distributed computing
environment, program modules may be located in local and/or remote
memory storage devices.
[0059] What has been described above includes examples of the
subject innovation. It is, of course, not possible to describe
every conceivable combination of components or methodologies for
purposes of describing the claimed subject matter, but one of
ordinary skill in the art may recognize that many further
combinations and permutations of the subject innovation are
possible. Accordingly, the claimed subject matter is intended to
embrace all such alterations, modifications, and variations that
fall within the spirit and scope of the appended claims.
[0060] In particular and in regard to the various functions
performed by the above described systems, components, devices, and
the like, the terms used to describe such components are intended
to correspond, unless otherwise indicated, to any component which
performs the specified function of the described component (e.g., a
functional equivalent), even though not structurally equivalent to
the disclosed structure, which performs the function in the herein
illustrated exemplary aspects of the claimed subject matter. In
this regard, it will also be recognized that the innovation
includes a system as well as a computer-readable medium having
computer-executable instructions for performing the acts and/or
events of the various methods of the claimed subject matter.
[0061] There are multiple ways of implementing the subject
innovation, e.g., an appropriate API, tool kit, driver code,
operating system, control, standalone, downloadable software
object, etc. which enables applications and services to use the
advertising techniques of the innovation. The claimed subject
matter contemplates the use from the standpoint of an API (or other
software object), as well as from a software or hardware object
that operates according to the advertising techniques in accordance
with the innovation. Thus, various implementations of the
innovation described herein may have aspects that are wholly in
hardware, partly in hardware and partly in software, as well as in
software.
[0062] The aforementioned systems have been described with respect
to interaction between several components. It can be appreciated
that such systems and components can include those components or
specified sub-components, some of the specified components or
sub-components, and/or additional components, and according to
various permutations and combinations of the foregoing.
Sub-components can also be implemented as components
communicatively coupled to other components rather than included
within parent components (hierarchical). Additionally, it should be
noted that one or more components may be combined into a single
component providing aggregate functionality or divided into several
separate sub-components, and any one or more middle layers, such as
a management layer, may be provided to communicatively couple to
such sub-components in order to provide integrated functionality.
Any components described herein may also interact with one or more
other components not specifically described herein but generally
known by those of skill in the art.
[0063] In addition, while a particular feature of the subject
innovation may have been disclosed with respect to only one of
several implementations, such feature may be combined with one or
more other features of the other implementations as may be desired
and advantageous for any given or particular application.
Furthermore, to the extent that the terms "includes," "including,"
"has," "contains," variants thereof, and other similar words are
used in either the detailed description or the claims, these terms
are intended to be inclusive in a manner similar to the term
"comprising" as an open transition word without precluding any
additional or other elements.
* * * * *