U.S. patent application number 12/633813 was filed with the patent office on 2010-06-17 for exhaust system of an internal combustion engine.
Invention is credited to Boris Kienle, Andreas Mayr.
Application Number | 20100146942 12/633813 |
Document ID | / |
Family ID | 42168757 |
Filed Date | 2010-06-17 |
United States Patent
Application |
20100146942 |
Kind Code |
A1 |
Mayr; Andreas ; et
al. |
June 17, 2010 |
EXHAUST SYSTEM OF AN INTERNAL COMBUSTION ENGINE
Abstract
An exhaust system of an internal combustion engine, in
particular of a vehicle, has an insert through which exhaust gas
flows, for purifying the exhaust gas, and a mixing chamber through
which exhaust gas flows and which is arranged upstream of the
insert through which exhaust gas flows. The mixing chamber includes
at least one permeable wall and is arranged on a channel wall of
the exhaust system and protrudes radially into the interior of the
exhaust system. The exhaust system further has a vaporizer device
that vaporizes an oxidizable liquid and introduces the vapor into
the mixing chamber, and an ignition device that protrudes at least
partly into the mixing chamber. The vaporizer device includes a
glow element which is configured and heatable in such a way that an
auto-ignition of the oxidizable vapor occurs on its surface.
Inventors: |
Mayr; Andreas; (Meitingen,
DE) ; Kienle; Boris; (Augsburg, DE) |
Correspondence
Address: |
PAMELA A. KACHUR
577 W Santee Drive
Greensburg
IN
47240
US
|
Family ID: |
42168757 |
Appl. No.: |
12/633813 |
Filed: |
December 9, 2009 |
Current U.S.
Class: |
60/286 ; 60/297;
60/303; 60/317 |
Current CPC
Class: |
Y02A 50/2322 20180101;
F01N 2560/06 20130101; F01N 2610/03 20130101; F01N 3/38 20130101;
F01N 3/106 20130101; F01N 3/36 20130101; F01N 3/0256 20130101; F01N
2610/10 20130101; F01N 13/0097 20140603; F01N 2610/107
20130101 |
Class at
Publication: |
60/286 ; 60/303;
60/317; 60/297 |
International
Class: |
F01N 9/00 20060101
F01N009/00; F01N 3/10 20060101 F01N003/10; F01N 3/02 20060101
F01N003/02; F01N 3/035 20060101 F01N003/035 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 16, 2008 |
DE |
10 2008 062 479.9 |
Claims
1. An exhaust system of an internal combustion engine, comprising:
a channel; an insert for purifying exhaust gas within said channel;
a mixing chamber arranged upstream of said insert; a vaporizer
device vaporizing an oxidizable liquid and introducing generated
oxidizable vapor into said mixing chamber; and an ignition device
protruding at least partly into said mixing chamber, said exhaust
gas flowing along said channel through said insert and said mixing
chamber, said mixing chamber including at least one permeable wall
and being arranged on a channel wall and protruding radially into
an interior of said exhaust system, and said vaporizer device
including a glow element heatable in such a way that an
auto-ignition of oxidizable vapor occurs on a surface of the glow
element.
2. The exhaust system according to claim 1, wherein said ignition
device includes one or more ignition electrodes producing an
ignition spark for ignition of the oxidizable vapor.
3. An exhaust system of an internal combustion engine, comprising:
a channel; an insert for purifying exhaust gas within said channel;
a mixing chamber arranged upstream of said insert; a vaporizer
device vaporizing an oxidizable liquid and introducing generated
oxidizable vapor into said mixing chamber; and an ignition device
protruding at least partly into said mixing chamber, said exhaust
gas flowing along said channel through said insert and said mixing
chamber, said mixing chamber including at least one permeable wall
and being arranged on a channel wall and protruding radially into
an interior of said exhaust system, and said ignition device
including at least one ignition electrode producing an ignition
spark for ignition of said oxidizable vapor.
4. The exhaust system according to claim 3, wherein said at least
one ignition electrode is arranged on a channel wall section
located radially opposite to said mixing chamber.
5. The exhaust system according to claim 3, wherein said at least
one ignition electrode is a spark plug.
6. The exhaust system according to claim 5, wherein at least one
opening is provided on said channel wall of said exhaust system,
said at least one spark plug protruding through said at least one
opening into a gas guiding channel.
7. The exhaust system according to claim 3, wherein said ignition
spark is produced between two electrodes.
8. The exhaust system according to claim 7, wherein said ignition
spark is in one of a substantially transverse and perpendicular
orientation to an inflow direction of said oxidizable liquid into
said mixing chamber.
9. The exhaust system according to claim 1, including an electronic
controller for at least one of said ignition device and said
vaporizer device.
10. The exhaust system according to claim 9, wherein said
electronic controller drives at least one of said ignition device
and said vaporizer device for igniting said vapor depending on at
least one of a temperature and exhaust gas flow.
11. The exhaust system according to 9, wherein said electronic
controller means controls the quantity of said vapor introduced
into said mixing chamber as a function of at least one of a
temperature and exhaust gas flow.
12. The exhaust system according to claim 1, wherein said vaporizer
device includes a glow element.
13. The exhaust system according to claim 12, wherein said glow
element terminates in a region of, or in, said mixing chamber.
14. The exhaust system according to claim 12, wherein said glow
element can be heated to different temperatures, said different
temperatures including at least a first temperature level which
ensures a vaporization of said oxidizable liquid and a second
temperature level which leads to an auto-ignition of said
vapor.
15. The exhaust system according to claim 1, wherein said insert
includes a diesel particulate filter.
16. The exhaust system according to claim 15, wherein an oxidation
catalytic converter is arranged in said insert in a flow direction
upstream of said diesel particulate filter.
17. The exhaust system according to claim 1, wherein said
oxidizable liquid is a fuel.
Description
RELATED APPLICATION
[0001] This applications claims priority to German application 10
2008 062 479.9, which was filed Dec. 16, 2008.
BACKGROUND OF THE INVENTION
[0002] To purify exhaust gases, vehicle exhaust systems have
inserts, for example catalytic converters or diesel particulate
filters having catalytic converters connected upstream. Particulate
filters require regeneration at regular intervals. To reach the
high temperatures that are required for the regeneration, in most
cases the particulate filter has an oxidation catalytic converter
connected upstream thereof in which the temperature of the exhaust
gas is raised. For regeneration it is known to introduce vapor
upstream of the particulate filter, the vapor acting as a
regeneration agent.
[0003] However, oxidation catalytic converters become active only
as of a particular temperature, which is not reached during a cold
start and in the starting phase of the engine. Increased pollutant
values are known to occur in this phase.
SUMMARY OF THE INVENTION
[0004] It is the object of the present invention to provide an
exhaust system which operates effectively in the warm-up phase of
the engine as well. In particular, the exhaust system according to
the invention is intended to allow a regeneration of the diesel
particulate filter at lower temperatures.
[0005] According to the invention, an exhaust system of an internal
combustion engine, comprises a channel, an insert for purifying
exhaust gas within the channel, a mixing chamber arranged upstream
of the insert, a vaporizer device vaporizing an oxidizable liquid
and introducing generated oxidizable vapor into the mixing chamber,
and an ignition device protruding at least partly into the mixing
chamber. The exhaust gas flows along the channel through the insert
and the mixing chamber. The mixing chamber includes at least one
permeable wall and is arranged on a channel wall and protrudes
radially into an interior of the exhaust system. The vaporizer
device includes a glow element which is heatable in such a way that
an auto-ignition of oxidizable vapor occurs on a surface of the
glow element.
[0006] The combination of the vaporizer device with the ignition
device necessitates no additional ignition elements, which reduces
the manufacturing expenditure. Since the oxidizable liquid is
ignited directly during or immediately upon the vaporizing process,
a reliable ignition is additionally ensured.
[0007] Furthermore, the invention provides an exhaust system of an
internal combustion engine, comprising a channel, an insert for
purifying exhaust gas within the channel, a mixing chamber arranged
upstream of the insert, a vaporizer device vaporizing an oxidizable
liquid and introducing generated oxidizable vapor into the mixing
chamber, and an ignition device protruding at least partly into the
mixing chamber. The exhaust gas flows along the channel through the
insert and the mixing chamber. The mixing chamber includes at least
one permeable wall and is arranged on a channel wall and protrudes
radially into an interior of the exhaust system. The ignition
device includes at least one ignition electrode producing an
ignition spark for ignition of the oxidizable vapor.
[0008] The oxidizable liquid or a mixture of the vaporized
oxidizable liquid and exhaust gas is ignited still inside the
mixing chamber before the oxidizable vapor is fed into the exhaust
gas channel or into the insert. An ignition spark reliably ensures
an ignition of the oxidizable vapor.
[0009] The ignition electrodes may be arranged, for example, on a
channel wall section which is located radially opposite to the
mixing chamber. In this way, the ignition electrodes are arranged
outside the mixing chamber and merely protrude into the mixing
chamber. This means that the electrodes can be manufactured
separately and are so compact as to be positionable in the region
of the vaporizer device.
[0010] The electrodes employed in this embodiment may be, for
example, spark plugs as are commonly used in the automotive sector,
which results in reduced manufacturing expenditure and production
costs.
[0011] In one example, openings are provided on the channel wall of
the exhaust system, with the spark plugs protruding through the
openings and into the gas guiding channel. The spark plugs may be
secured to rims of the openings, for example by a thread provided
in each opening or by separate fastening elements. In this way, the
spark plugs may be installed or replaced in a simple manner.
[0012] To produce a larger or longer ignition spark, the ignition
spark may also be produced between two electrodes. This allows the
size or length of the ignition spark to be ensured and varied to
achieve an improved and reliable ignition effect.
[0013] In addition, the arrangement of the electrodes in the mixing
chamber allows the ignition spark to be ideally oriented relative
to an inflow direction of the oxidizable liquid, so that a more
effective ignition occurs. In one example, the electrodes are
arranged such that the ignition spark is oriented substantially
transversely or perpendicularly to the inflow direction of the
oxidizable liquid into the mixing chamber.
[0014] In one example, an electronic controller is provided for the
ignition device and/or the vaporizer device. The electronic
controller on the vaporizer device allows both the amount of the
oxidizable liquid and also the temperature of the vaporizer device
to be regulated, so that consumption of the oxidizable liquid can
be controlled. In addition, an electronic controller for the
ignition device permits a generation of an ignition spark as
needed, so that the exhaust system can be operated more
effectively.
[0015] The electronic controller drives the ignition device and/or
the vaporizer device depending on the temperature and/or the
exhaust gas flow, for example. The amount of the oxidizable vapor
can be regulated such that the exhaust gas temperature is
maintained in a temperature range that is ideal for the
regeneration of the insert. When the temperature in the gas guiding
channel is sufficiently high, the electronic controller can reduce
the supply of the oxidizable vapor and, where required, suspend the
ignition of the oxidizable vapor or, in case the temperature is too
low, can supply the oxidizable vapor and/or activate the ignition.
The exhaust gas flow may likewise be made use of as an indicator
for the electronic controller, since a higher exhaust gas flow
occurs in the case of higher speeds and higher exhaust gas
temperatures resulting therefrom.
[0016] The electronic controller controls more particularly the
quantity of the vapor introduced into the mixing chamber as a
function of the temperature and/or the exhaust gas flow. The
quantity of the oxidizable vapor allows the combustion in the
exhaust system and, hence, the exhaust gas temperature to be
controlled especially effectively, so that the ideal temperatures
for a regeneration are always reached in the exhaust gas flow.
[0017] In one example, the vaporizer device includes a glow
element, in particular a glow plug, which terminates in the region
of, or in, the mixing chamber. The glow element produces the high
temperatures that are necessary for a vaporization of the
oxidizable liquid.
[0018] In one example, the glow element can be heated to different
temperatures. The glow element can be heated to a first temperature
level which ensures a vaporization of the liquid, and a second
temperature level which leads to an auto-ignition of the vapor. As
a result, only one component is required for vaporizing the liquid
and for igniting the vapor.
[0019] The insert of the exhaust system includes a diesel
particulate filter, and an oxidation catalytic converter, for
example, is arranged in the flow direction upstream of the diesel
particulate filter. The catalytic converter may also be dispensed
with; in that case, the particulate filter would be burnt free upon
ignition of the vapor.
[0020] The vaporized liquid may, for example, be a fuel, in
particular a diesel fuel.
[0021] These and other features of the present invention can be
best understood from the following specification and drawings, the
following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 shows a schematic view of an exhaust system according
to the invention;
[0023] FIG. 2 shows a sectional view of the exhaust system
according to the invention in the region of the vaporizer device;
and
[0024] FIG. 3 shows a perspective view of the exhaust system from
FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0025] FIG. 1 illustrates an exhaust system of an internal
combustion engine, in particular of an internal combustion engine
of a motor vehicle. Reference numeral 2 denotes an exhaust
gas-carrying pipe that accommodates a diesel particulate filter 4.
Arranged in the diesel particulate filter 4 is a body 6 through
which exhaust gas flows and which is also known as a substrate or
insert and constitutes the filter body. Positioned upstream of the
diesel particulate filter 4 is an oxidation catalytic converter 8
which may be applied onto the substrate of the filter body or may
be configured as a separate body.
[0026] The wall of the pipe 2 constitutes a channel wall 12 of the
exhaust system 10, which in its interior defines a gas guiding
channel 14.
[0027] Provided upstream of the diesel particulate filter 4 is a
vaporizer device 16 and, optionally, an ignition device 18 which is
likewise arranged in the region of the vaporizer device 16 in the
gas guiding direction.
[0028] As can be seen in section according to FIG. 2, the vaporizer
device 16 and the ignition device 18 are attached to the channel
wall 12.
[0029] Arranged in the gas guiding channel 14 is a mixing chamber
20 which is defined by a cylindrical wall 22 which is fastened to
the channel wall 12 and has openings 23 on its entire peripheral
surface, so that the exhaust gas can flow through the mixing
chamber (see in particular FIG. 3).
[0030] The ignition device 18 is fastened to a wall section of the
channel wall 12 radially opposite to the mixing chamber 20 and has
a free end that protrudes into the mixing chamber 20, as does the
vaporizer device 16.
[0031] The vaporizer device 16 has a glow element 24 and a feed
line 26 through which an oxidizable liquid is fed to the glow
element 24. The oxidizable liquid is vaporized by the glow element
24 and reaches the mixing chamber 20 in an axial inflow direction
E.
[0032] In the mixing chamber 20 the vaporized liquid is mixed with
the exhaust gas flowing through. At a sufficiently high
temperature, the oxidizable vapor burns with the residual oxygen
contained in the exhaust gas and thus raises the temperature of the
exhaust gas, so that the oxidation catalytic converter 8 that is
arranged downstream of the vaporizer device 16 in the flow
direction is heated to the operating temperature.
[0033] An ignition of the oxidizable liquid or of the oxidizable
vapor may be effected by the ignition device 18 protruding into the
mixing chamber 20. The ignition device 18 has two spark plugs 28 in
this example, which each protrude into the mixing chamber 20 by an
electrode 30. The spark plugs 28 are each secured in an opening 32
in the channel wall 12 and each protrude into the mixing chamber 20
by an electrode 30. When the catalytic converter is heated up, an
ignition spark Z, which is oriented transversely to an inflow
direction E, will be generated between the electrodes 30. The
ignition spark ignites the oxidizable vapor or the mixture
consisting of oxidizable vapor and exhaust gas.
[0034] Activation of the ignition device 18 may be effected here by
an electronic controller which checks, for example, a temperature
of the exhaust gas and, when the temperature is not sufficient for
a regeneration, drives the ignition device 18, so that the ignition
spark Z is produced. The controlling process may, however, be
effected also as a function of other measured variables, such as,
e.g., the exhaust gas flow. But embodiments without an electronic
controller are also conceivable.
[0035] Provision is further made for the vaporizer device 16 to
have a controller which regulates the supply of the oxidizable
liquid as a function of the exhaust gas temperature, for example.
The controller may likewise regulate the temperature of the glow
element 24 and in this way control the vaporizing quantity of the
oxidizable liquid.
[0036] The spark plugs 28 of the ignition device 18 are each
arranged in an opening 32 and each protrude into the mixing chamber
20 by an electrode 30. This allows the spark plugs 28 to be quickly
replaced. But the spark plugs 28 may also be arranged on the
exhaust system 10 in any other way.
[0037] Instead of the spark plugs 28 shown here, other electrodes
30 may also be used. In particular, it is also possible to provide
only one spark plug 28 having two electrodes 30.
[0038] The electrodes 30 may protrude into the mixing chamber 20 in
any desired manner to produce an ignition spark Z. In particular,
the ignition spark Z need not be oriented transversely to the
inflow direction E of the oxidizable liquid.
[0039] The ignition device 18 need not necessarily be arranged on a
section of the channel wall 12 located radially opposite to the
mixing chamber 20. The ignition device 18 may be arranged on the
exhaust system 10 in any desired way. In particular, it is
conceivable for the ignition device 18 to be arranged on, or
integrated in, the vaporizer device 16.
[0040] The shape and the size of the mixing chamber 20 may likewise
be varied as desired, just as the openings 23 on the wall 22 of the
mixing chamber may be varies. More particularly, the mixing chamber
20 need not be of a cylindrical design.
[0041] Rather than by the ignition device 18, the ignition of the
oxidizable vapor may also be effected by the vaporizer device 16.
In this case, the ignition will be effected by the glow element 24,
which is heatable to such an extent that an auto-ignition of the
oxidizable vapor occurs on its surface. To this end, the glow
element 24 is heated to different temperature levels, for example,
on the one hand for the vaporization and, on the other hand, for
vaporization and subsequent auto-ignition of the vapor/gas mixture
at the end of the glow element 24. In this embodiment, the ignition
devices 18 may optionally be dispensed with.
[0042] Although an embodiment of this invention has been disclosed,
a worker of ordinary skill in this art would recognize that certain
modifications would come within the scope of this invention. For
that reason, the following claims should be studied to determine
the true scope and content of this invention.
* * * * *