U.S. patent application number 11/306147 was filed with the patent office on 2006-09-07 for apparatus for adjusting the temperature of exhaust gases.
This patent application is currently assigned to VOLVO LASTVAGNAR AB. Invention is credited to Carl-Johan Karlsson, Paulina Tengstrom.
Application Number | 20060196176 11/306147 |
Document ID | / |
Family ID | 27607364 |
Filed Date | 2006-09-07 |
United States Patent
Application |
20060196176 |
Kind Code |
A1 |
Karlsson; Carl-Johan ; et
al. |
September 7, 2006 |
APPARATUS FOR ADJUSTING THE TEMPERATURE OF EXHAUST GASES
Abstract
Apparatus for adjusting the temperature of exhaust gases passing
through an exhaust system of a vehicle having an internal
combustion engine. The exhaust system is provided with an active
regeneration filter for collecting particles from the exhaust gas
stream. The apparatus includes a heat exchanger that has a first
flow passage for an exhaust gas stream from the exhaust manifold of
the engine to the particle filter and a second flow passage for an
exhaust gas stream from the particle filter to the outlet pipe of
the exhaust system.
Inventors: |
Karlsson; Carl-Johan;
(Goteborg, SE) ; Tengstrom; Paulina; (Askim,
SE) |
Correspondence
Address: |
NOVAK DRUCE & QUIGG, LLP
1300 EYE STREET NW
400 EAST TOWER
WASHINGTON
DC
20005
US
|
Assignee: |
VOLVO LASTVAGNAR AB
S-405 08
Goteborg
SE
|
Family ID: |
27607364 |
Appl. No.: |
11/306147 |
Filed: |
December 16, 2005 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
PCT/SE04/00937 |
Jun 14, 2004 |
|
|
|
11306147 |
Dec 16, 2005 |
|
|
|
Current U.S.
Class: |
60/297 ; 60/295;
60/300 |
Current CPC
Class: |
F01N 2240/02 20130101;
F01N 3/023 20130101; F01N 3/035 20130101 |
Class at
Publication: |
060/297 ;
060/300; 060/295 |
International
Class: |
F01N 3/00 20060101
F01N003/00; F01N 3/10 20060101 F01N003/10 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 18, 2003 |
SE |
0301799-3 |
Claims
1. An apparatus for adjusting the temperature of exhaust gases
passing through an exhaust system (11-17) of a vehicle having an
internal combustion engine (10), which exhaust system is provided
with an active regeneration filter (14) for collecting particles
from the exhaust gas stream, and which apparatus comprises a heat
exchanger (12), which has a first flow passage for an exhaust gas
stream from the exhaust manifold (11) of the engine to the particle
filter (14) and a second flow passage for an exhaust gas stream
from the particle filter (14) to the outlet pipe (17) of the
exhaust system, and characterized in that the particle filter (14)
is provided with an oxidation catalyst (13) for intermittent
combustion of accumulated soot.
2. The apparatus as recited in claim 1, further characterized in
that the combustion chamber of the engine (10) is provided with an
injector for injecting fuel into the exhaust gases.
3. The apparatus as recited in claim 1, further characterized in
that an injector is placed in the exhaust system upstream of the
particle filter (14), for injecting fuel into the exhaust
gases.
4. An apparatus for adjusting the temperature of an exhaust gas
stream emanating from an internal combustion engine of a vehicle
and passing through an exhaust system thereof, said exhaust system
comprising: an active regeneration filter for collecting particles
from the exhaust gas stream; a heat exchanger having a first flow
passage for an exhaust gas stream from the exhaust manifold of the
engine to the particle filter and a second flow passage for an
exhaust gas stream from the particle filter to an outlet pipe of
the exhaust system; and said particle filter being provided with an
oxidation catalyst for intermittent combustion of accumulated
soot.
5. The apparatus as recited in claim 4, further comprising said
internal combustion engine having an injector that injects fuel
into the exhaust gases.
6. The apparatus as recited in claim 4, further comprising an
injector located in the exhaust system upstream of the particle
filter which injects fuel into the exhaust gases.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation patent application
of International Application No. PCT/SE2004/000937 filed 14 Jun.
2004 which is published in English pursuant to Article 21(2) of the
Patent Cooperation Treaty, and which claims priority to Swedish
Application No. 0301799-3 filed 18 Jun. 2003. Said applications are
expressly incorporated herein by reference in their entireties.
TECHNICAL FIELD OF THE INVENTION
[0002] The present invention relates to an apparatus for adjusting
the temperature of exhaust gases passing through an exhaust system
of a vehicle that has an internal combustion engine. Furthermore,
the exhaust system is provided with an active regeneration filter
for collecting particles from the exhaust gas stream and which
apparatus comprises a heat exchanger.
BACKGROUND OF THE INVENTION
[0003] Active regeneration particle filters can be used for the
after-treatment of exhaust gases from diesel engines for catching
soot and ash particles instead of allowing them to be dispersed
into the surrounding environment. By active regeneration it is
meant that the temperature of the exhaust is intermittently
increased upstream of the filter to such an extent that the
particles can be burnt off. Further, an oxidation catalyst can be
integrated with the filter for the increase in temperature.
[0004] The oxidation catalyst uses uncombusted fuel in the exhaust
gas stream to create the preconditions for regeneration. This
uncombusted fuel can be fed to the exhaust gas stream, for example,
through the normal injection system of the engine and is commonly
termed post- injection.
[0005] The effect of the high temperatures generated in active
regeneration (oxygen-based) is that the temperature of gases
discharged from a vehicle through the exhaust pipe can be extremely
high (around 600 degrees Celsius). This can cause a fire risk and
create danger for other road-users, for example pedestrians. One
way of cooling the exhaust gases can be, for example, to pass the
exhaust gases through a cooler that uses ambient air as a cooling
medium. This type of cooler is usually provided with a fan so as to
provide cooling air when the vehicle is stationary or traveling at
low speed, which expediently is the state in which the vehicle
finds itself during regeneration of its particle filter. A
drawback, however, with these types of exhaust coolers with a fan
is that they are both bulky and expensive.
SUMMARY OF THE INVENTION
[0006] One object of the present invention is therefore to produce
a cost-effective and space-saving apparatus for reducing the
temperature of the exhaust gas stream leaving a vehicle having a
diesel engine with an active regeneration particle filter.
[0007] In at least one embodiment, the invention takes the form of
a purpose-built apparatus for adjusting the temperature of exhaust
gases passing through an exhaust system of a vehicle that has an
internal combustion engine. The exhaust system is provided with an
active regeneration filter for collecting particles from the
exhaust gas stream and which comprises (includes, but is not
limited to) a heat exchanger that, according to the invention, has
a first flow passage for an exhaust gas stream from the exhaust
manifold of the engine to the particle filter and a second flow
passage for an exhaust gas stream from the particle filter to the
outlet pipe of the exhaust system. By virtue of this configuration
of the apparatus, the temperature of the exhaust gas stream leaving
the vehicle can be lowered at the same time as the thermal energy
can be utilized to heat up the gas flow into the particle filter.
This also means that less fuel is needed for the active
regeneration.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The invention will be described in greater detail below with
reference to an illustrative embodiment shown in the accompanying
drawing that diagrammatically represents an internal combustion
engine arrangement configured according to the teachings of the
present invention.
DETAILED DESCRIPTION
[0009] FIG. 1 diagrammatically illustrates a diesel engine 10
installed in a vehicle, for example a truck or a bus, and which is
provided with an exhaust system comprising an exhaust manifold 11
connected to a heat exchanger 12. A silencer having an oxidation
catalyst 13 and a particle filter 14 is connected to the heat
exchanger 12 by, on the one hand, an inlet pipeline 15 and, on the
other hand, an outlet pipeline 16.
[0010] A first flow passage through the heat exchanger 12 extends
vertically in the figure and allows an exhaust gas stream from the
exhaust manifold 11 of the engine, via the inlet pipeline 15, to
the particle filter 14. A second flow passage through the heat
exchanger 12 extends horizontally in the figure and conveys an
exhaust gas stream from the particle filter 14, via the outlet
pipeline 16, to the outlet pipe 17 of the exhaust system.
[0011] Through active regeneration, using oxygen as the oxidant,
soot particles can be automatically removed from the particle
filter, whereby servicing and maintenance requirements are reduced.
Regeneration can take place at an appropriate time, when the
vehicle has traveled a certain distance or when the engine has
operated at a certain load for a certain period of time.
[0012] In order to activate the regeneration of the particle
filter, the injectors of the engine are exemplarily equipped with
means for injecting fuel into the exhaust gases for so-called
post-injection. Alternatively, an extra injector can be placed in
the exhaust system upstream of the particle filter to inject fuel
into the exhaust gases.
[0013] The exhaust gas temperature upon exit from the engine via
the exhaust manifold 11 can measure around 200 degrees Celsius
under low load. When an active regeneration is initiated, the
temperature of the exhaust gas flow exiting the silencer will
initially increase owing to combustion of hydrocarbons in the
oxidation catalyst belonging to the system. Gradually, the soot
combustion in the particle filter begins, whereupon temperatures in
excess of 1000 degrees Celsius can be generated and occur locally.
The gas flow from the silencer to the heat exchanger via the outlet
pipeline 16 therefore has a temperature not less than around 600
degrees Celsius. This hot gas stream is cooled during its passage
through the heat exchanger 12 and leaves the vehicle via the outlet
pipe 17 at a temperature of, for example, around 400 degrees
Celsius (at 50% heat exchanger efficiency). The thermal energy from
the hot gas stream is used to heat the gas stream emanating from
the exhaust manifold, in which case a substantially smaller
quantity of fuel is needed to initiate the active regeneration.
[0014] The invention shall not be deemed to be limited to the
illustrative embodiments described above. Instead, a number of
further variants and modifications are conceivable and within the
scope of the patent claims.
* * * * *