U.S. patent application number 12/643374 was filed with the patent office on 2011-03-31 for electrically heated diesel oxidation catalyst.
This patent application is currently assigned to International Engine Intellectual Property Company LLC. Invention is credited to Artur Dudzik, Joshua Horner.
Application Number | 20110072805 12/643374 |
Document ID | / |
Family ID | 43778766 |
Filed Date | 2011-03-31 |
United States Patent
Application |
20110072805 |
Kind Code |
A1 |
Horner; Joshua ; et
al. |
March 31, 2011 |
ELECTRICALLY HEATED DIESEL OXIDATION CATALYST
Abstract
An exhaust gas aftertreatment system (10) for a vehicle having
an engine (14) includes a fluid passageway (20) extending from the
engine to an ambient (18) for fluidly communicating exhaust gas
(F). A diesel particulate filter (30) is disposed on the fluid
passageway downstream of the engine (14). Disposed downstream of
the engine (14) and upstream of the diesel particulate filter (30)
is an electric diesel oxidation catalyst (24) having a substrate
(34). A first electrode (40) and a second electrode (46) are
attached to the electric diesel oxidation catalyst (24). The first
electrode (40) selectively delivers current through the substrate
(34) to the second electrode (46) to generate heat at the substrate
(34).
Inventors: |
Horner; Joshua; (Oak Park,
IL) ; Dudzik; Artur; (Berwyn, IL) |
Assignee: |
International Engine Intellectual
Property Company LLC
Warrenville
IL
|
Family ID: |
43778766 |
Appl. No.: |
12/643374 |
Filed: |
December 21, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61246012 |
Sep 25, 2009 |
|
|
|
Current U.S.
Class: |
60/295 ; 60/297;
60/299; 60/300 |
Current CPC
Class: |
F01N 3/106 20130101;
F01N 13/009 20140601; Y02T 10/26 20130101; F01N 3/281 20130101;
Y02T 10/12 20130101; F01N 3/2026 20130101; F01N 3/035 20130101;
Y02A 50/2322 20180101; Y02A 50/20 20180101; F01N 3/027
20130101 |
Class at
Publication: |
60/295 ; 60/299;
60/297; 60/300 |
International
Class: |
F01N 3/023 20060101
F01N003/023; F01N 3/10 20060101 F01N003/10; F01N 3/035 20060101
F01N003/035 |
Claims
1) An exhaust gas aftertreatment system for a vehicle having an
engine, the aftertreatment system comprising: a fluid passageway
extending from the engine to an ambient for fluidly communicating
exhaust gas; a diesel particulate filter disposed on the fluid
passageway downstream of the engine; an electric diesel oxidation
catalyst disposed downstream of the engine and upstream of the
diesel particulate filter on the fluid passageway, the electric
diesel oxidation catalyst having a substrate; and a first electrode
and a second electrode attached to the electric diesel oxidation
catalyst, the first electrode for selectively delivering current
through the substrate to the second electrode to generate heat at
the substrate.
2) The aftertreatment system of claim 1 further comprising a first
transmission wire electrically connected to the engine for
providing electric current to the first electrode.
3) The aftertreatment system of claim 2 further comprising a second
transmission wire electrically connected to the engine for
transmitting electric current from the second electrode to the
engine.
4) The aftertreatment system of claim 1 wherein the electric diesel
oxidation catalyst includes a housing enclosing the substrate.
5) The aftertreatment system of claim 4 further comprising an
isolator disposed about the first electrode to prevent the contact
of the first electrode with the housing.
6) The aftertreatment system of claim 1 wherein the substrate
permits the flow of exhaust gas therethrough.
7) The aftertreatment system of claim 1 wherein the first electrode
extends into the electric diesel oxidation catalyst generally the
radius of the electric diesel oxidation catalyst.
8) The aftertreatment system of claim 1 wherein the first electrode
and the second electrode are spaced from each other and separated
by the substrate.
9) The aftertreatment system of claim 1 further comprising a diesel
oxidation catalyst disposed on the fluid passageway downstream of
the electric diesel oxidation catalyst and upstream of the diesel
particulate filter.
10) A method of regenerating an exhaust aftertreatment system of an
engine having a diesel particulate filter, the method comprising:
providing a fluid passageway from the engine to an ambient;
providing a substrate upstream of the diesel particulate filter on
the fluid passageway; heating the substrate electrically; heating
exhaust gas flowing through the heated substrate; and delivering
the heated exhaust gas to the diesel particulate filter to initiate
regeneration.
11) The method of claim 11 further comprising the step of
contacting a first electrode with the substrate.
12) The method of claim 12 further comprising the step of
connecting the first electrode to the engine with a first
transmission wire.
13) The method of claim 12 further comprising the step of
contacting a second electrode with a housing that substantially
encloses the substrate.
14) The method of claim 13 further comprising the step of
connecting the second electrode to the engine with a second
transmission wire.
15) The method of claim 14 further comprising the step of providing
electric current from the engine to the first electrode, through
the substrate, to the second electrode, and back to the engine.
16) An electric diesel oxidation catalyst for an exhaust
aftertreatment system of an engine, the electric diesel oxidation
catalyst comprising: a housing substantially enclosing a substrate,
the housing having an inlet and an outlet configured for permitting
a flow of exhaust gas through the housing; a first electrode
extending through the housing configured for providing an electric
current to the substrate; and a second electrode extending from the
housing configured for receiving the electric current from the
substrate.
17) The electric diesel oxidation catalyst of claim 16 wherein the
first electrode contacts the substrate generally at the
cross-sectional center of the substrate.
18) The electric diesel oxidation catalyst of claim 16 wherein the
first electrode and the second electrode are spaced from each other
and separated by the substrate.
19) The electric diesel oxidation catalyst of claim 16 further
comprising an isolator sleeve disposed around the first
electrode.
20) The electric diesel oxidation catalyst of claim 16 wherein the
housing is generally cylindrical.
Description
BACKGROUND
[0001] Embodiments described herein relate to a system, method and
device for heating exhaust gas. More specifically, embodiments
described herein relate to a system, method and device for heating
exhaust gas to create a regeneration event at a diesel particulate
filter.
[0002] Exhaust gas aftertreatment systems in diesel vehicles are
located downstream of the engine for treating exhaust gases emitted
from the engine. The aftertreatment systems typically include a
diesel oxidation catalyst, and a diesel particulate filter.
Particulate matter from the exhaust gas accumulates on the diesel
particulate filter, and if left unchecked, can create a back
pressure in the aftertreatment system.
[0003] A regeneration event is the periodic oxidation of the
collected particulate matter in the aftertreatment system during
routine diesel engine operation. When the diesel particulate filter
of the exhaust system experiences a build-up of particulate matter,
the particulate matter is oxidized to "regenerate" the filter.
Regeneration is typically initiated by increasing engine load and
activating a post-injection of diesel fuel into the exhaust stream.
This post-injection provides sufficient heat to oxidize the trapped
particulate matter within the diesel particulate filter.
[0004] Exhaust gas is a relatively poor conductor of heat. As such,
the loading of the engine must be increased to provide a
sufficiently heated exhaust gas to initiate the regeneration
downstream at the diesel particulate filter. During low speed and
low load operation of the engine, the resulting exhaust gas may not
have a sufficiently high temperature to initiate the
regeneration.
SUMMARY
[0005] An exhaust gas aftertreatment system for a vehicle having an
engine includes a fluid passageway extending from the engine to an
ambient for fluidly communicating exhaust gas. A diesel particulate
filter is disposed on the fluid passageway downstream of the
engine. Disposed downstream of the engine and upstream of the
diesel particulate filter is an electric diesel oxidation catalyst
having a substrate. A first electrode and a second electrode are
attached to the electric diesel oxidation catalyst. The first
electrode selectively delivers current through the catalyst
substrate to the second electrode to generate heat at the catalyst
substrate.
[0006] A method of regenerating an exhaust aftertreatment system of
an engine having a diesel particulate filter includes the steps of
providing a fluid passageway from the engine to an ambient,
providing a substrate upstream of the diesel particulate filter,
and heating the substrate electrically. The method of regeneration
also includes the steps of heating the exhaust gas flowing through
the heated substrate, and delivering the heated exhaust gas to the
diesel particulate filter to initiate regeneration.
[0007] An electric diesel oxidation catalyst for an exhaust
aftertreatment system of an engine includes a housing that
substantially encloses a substrate. The housing has an inlet and an
outlet configured for permitting a flow of exhaust gas through the
housing. A first electrode extends through the housing and is
configured for providing an electric current to the substrate. A
second electrode extends from the housing and is configured for
receiving the electric current from the substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a schematic of an exhaust aftertreatment system
having an electric diesel oxidation catalyst located downstream of
an engine.
[0009] FIG. 2 is a schematic indicating the direction of flow of
exhaust gas through the electric diesel oxidation catalyst.
[0010] FIG. 3 is a section view of the electric diesel oxidation
catalyst taken along line A-A of FIG. 2.
DETAILED DESCRIPTION
[0011] Referring to FIGS. 1-3, an exhaust gas aftertreatment system
is indicated generally at 10, and has an exhaust pipe assembly 12
extending from an engine 14 to an outlet 16, such as the outlet to
an ambient 18. The exhaust pipe assembly 12 forms a fluid
passageway 20 for the flow of exhaust gas F from the engine 14 to
the ambient 18.
[0012] A first portion 22 of the exhaust pipe assembly 12 extends
from the engine 14 to an electric diesel oxidation catalyst (EDOC)
24. A second portion 26 of the exhaust pipe assembly 12 extends
from the EDOC 24 to a diesel oxidation catalyst (DOC) 28, which is
upstream of diesel particulate filter (DPF) 30. A third portion 27
of the exhaust pipe 12 assembly extends from the DPF 30 to the
outlet 16. Other portions of the exhaust pipe may be disposed
between various components on the aftertreatment system 10, such as
between the engine 14 and an exhaust brake 29, between the exhaust
brake and the EDOC 24, or between the DOC 28 and the DPF 30.
[0013] The DPF 30 is a filter constructed from a very high
temperature resistant material. The DPF 30 catches and holds
particulate matter entrained within the exhaust gases discharged
into the exhaust aftertreatment system 10. The DPF 30 is
periodically regenerated to limit increases in exhaust
aftertreatment system 10 back pressure and to maintain engine 14
efficiency.
[0014] The DOC 28 is a flow-through device that includes a
substrate, typically a ceramic or a metal covered with a catalyst.
As the exhaust gases F flow through the DOC 28, carbon monoxide,
gaseous hydrocarbons and liquid hydrocarbon particles (unburned
fuel and oil) are oxidized, thereby reducing emissions.
[0015] Upstream of the DPF 30 and the DOC 28 is the EDOC 24. The
EDOC 24 has a housing 32 that substantially encloses a substrate 34
having a structure that permits the flow of exhaust gas F through
the substrate and that is distributed within the cross-section of
the EDOC, for example a grid-shape, a swirl-shape, a
honeycomb-shape, a circuitous-shape, a mesh-shape, or any other
shape. The substrate 34 is made of metal, however other highly
conductive materials are possible.
[0016] The housing 32 may be generally cylindrical or have any
other shape that permits the flow of exhaust gas F from an inlet 36
to an outlet 38 and through the substrate 34. The first portion 22
of the pipe assembly 12 provides the fluid passageway 20 for the
flow of exhaust gas F into the EDOC 24 at the inlet 36, and the
second portion 26 of the pipe assembly provides the fluid
passageway for the flow of exhaust gas F out of the EDOC at the
outlet 38. The housing 32 of the EDOC 24 may be metal, however
other materials are possible.
[0017] A first electrode 40 is electrically connected to a power
source on the vehicle, such as the engine 14, with a first
transmission wire 42. The first electrode 40 extends through the
housing of the EDOC 24, and may extend generally the radius or
generally half the width of the EDOC, however other lengths of
extension into the EDOC are possible. The first electrode 40
contacts the substrate 34 generally at the cross-sectional center C
of the EDOC 24 and the substrate. An isolator sleeve 44 is disposed
about the first electrode 40 to prevent the contact of the first
electrode with the housing 32 of the EDOC 24. The isolator sleeve
44 co-extends with the first electrode 40 less than the entire
length of the first electrode 40 so that a portion of the first
electrode is exposed. When current is run to the first electrode
40, the current is isolated from the housing 32 and the current is
directed to the general cross-sectional center C of the EDOC
24.
[0018] A second electrode 46 extends from the housing 32 of the
EDOC 24 and is also electrically connected to the engine 14 with a
second transmission wire 48. While the second electrode 46 extends
from the housing, it is also possible that the second electrode 46
may contact the substrate 34.
[0019] The first electrode 40 does not contact the second electrode
46, but instead the electrodes are spaced from each other and
separated by the substrate 34 within the EDOC 24. The electrodes
40, 46 may also be spaced from each other a distance D along the
length of the EDOC 24. The first electrode 40 delivers current from
the engine 14 through the substrate 34 to the second electrode 48.
It is possible that the selective introduction of current into the
EDOC 24 can be at the activation of a user or an automatic
activation, such as by an engine control module.
[0020] When the current flows from the first electrode 40, through
the substrate 34, and to the second electrode 48, heat is created
at the substrate. When current is delivered to the general
cross-sectional center C of the substrate 34, the heat created is
generally uniform across the substrate 34. The exhaust gases F that
flow through the EDOC 24 are heated by the substrate 34 and the
housing 32, and the heated exhaust gases flow to the DOC 28 and to
the DPF 30. At the DPF 30, the heated exhaust gases F provide
sufficient heat to initiate regeneration of the DPF.
[0021] While the aftertreatment system 10 of FIG. 1 has the EDOC 24
located upstream of the DOC 28, it is possible that if the EDOC 24
achieves a sufficient exhaust gas temperature, that the
aftertreatment system may include only the EDOC with no downstream
DOC. Further, it is possible that more than one EDOC 24 can be used
to increase the exhaust gas temperature.
[0022] By electrically heating the EDOC 24, the DPF 30 on the
aftertreatment system 10 can be regenerated without having to
increase the loading on the engine 14, which allows regeneration at
low engine speed and low engine loading.
* * * * *