U.S. patent application number 12/488054 was filed with the patent office on 2010-12-23 for airless thermal regenerator or enhancer with mixer.
Invention is credited to Navin Khadiya.
Application Number | 20100319329 12/488054 |
Document ID | / |
Family ID | 43353080 |
Filed Date | 2010-12-23 |
United States Patent
Application |
20100319329 |
Kind Code |
A1 |
Khadiya; Navin |
December 23, 2010 |
AIRLESS THERMAL REGENERATOR OR ENHANCER WITH MIXER
Abstract
A combustor comprises a fuel-fired burner for a vehicle
application. In one example, the fuel-fired burner is configured to
regenerate a particulate filter where the fuel-fired burner
comprises one of a thermal regenerator or thermal enhancer that
operates with airless fuel injection. A fuel nozzle supplies fuel
to the fuel-fired burner and an igniter ignites fuel sprayed from
the fuel nozzle. A mixer is positioned downstream of the fuel
nozzle and upstream of the igniter and operates to reduce fuel
droplet size, which improves ignition.
Inventors: |
Khadiya; Navin; (Columbus,
IN) |
Correspondence
Address: |
PAMELA A. KACHUR
577 W Santee Drive
Greensburg
IN
47240
US
|
Family ID: |
43353080 |
Appl. No.: |
12/488054 |
Filed: |
June 19, 2009 |
Current U.S.
Class: |
60/295 ; 60/297;
60/303 |
Current CPC
Class: |
B01F 5/0616 20130101;
F01N 3/0256 20130101; F01N 3/36 20130101; B01F 5/0693 20130101;
B01F 5/0608 20130101; B01F 5/0603 20130101; Y02A 50/2322 20180101;
B01F 5/0643 20130101; F01N 2240/20 20130101; F01N 9/002 20130101;
B01F 5/0682 20130101; Y02A 50/20 20180101 |
Class at
Publication: |
60/295 ; 60/297;
60/303 |
International
Class: |
F01N 3/023 20060101
F01N003/023; F01N 3/035 20060101 F01N003/035; F01N 3/10 20060101
F01N003/10 |
Claims
1. A component assembly comprising: a combustor comprising a
fuel-fired burner having airless fuel injection; at least one fuel
nozzle to supply fuel to said combustor; an igniter to ignite fuel
sprayed from said at least one fuel nozzle; and a mixer positioned
downstream of said at least one fuel nozzle and upstream of said
igniter.
2. The component assembly according to claim 1 wherein said
fuel-fired burner comprises one of a thermal regenerator or thermal
enhancer.
3. The component assembly according to claim 2 wherein said
fuel-fired burner is configured to regenerate a particulate
filter.
4. The component assembly according to claim 1 wherein said mixer
solely mixes fuel with existing exhaust gases for ignition without
requiring an additional atomization air supply.
5. The component assembly according to claim 1 including a housing
having an exhaust gas inlet, an exhaust gas outlet, and an internal
wall structure positioned within said housing to define a
combustion chamber, and wherein said mixer is supported by said
internal wall structure within said combustion chamber.
6. The component assembly according to claim 5 wherein said at
least one fuel nozzle defines a nozzle axis extending along a
length of said at least one fuel nozzle, and wherein said exhaust
gas inlet defines an exhaust gas flow axis that is non-parallel to
said nozzle axis.
7. The component assembly according to claim 5 wherein said at
least one fuel nozzle defines a nozzle axis extending along a
length of said at least one fuel nozzle, and wherein said exhaust
gas inlet defines an exhaust gas flow axis that is parallel to said
nozzle axis.
8. The component assembly according to claim 5 wherein said at
least one fuel nozzle defines a nozzle axis extending along a
length of said at least one fuel nozzle and wherein said mixer is
axially spaced from a tip of said at least one fuel nozzle along
said nozzle axis and said igniter is axially spaced from said mixer
along said nozzle axis.
9. The component assembly according to claim 1 wherein said igniter
comprises at least one electrode positioned downstream of said
mixer.
10. The component assembly according to claim 1 wherein said mixer
is defined by an outer peripheral surface with a downstream end
face and an upstream end face, and wherein said downstream and
upstream end faces provide discontinuous surfaces that cooperate to
reduce the size of fuel droplets flowing through said mixer from
said upstream end face to said downstream end face.
11. The component assembly according to claim 1 wherein said
fuel-fired burner is configured to heat up a NOx reduction
catalyst.
12. A method of assembling a component comprising the steps of: (a)
providing a combustor comprising a fuel-fired burner having airless
fuel injection, providing at least one fuel nozzle to supply fuel
to the combustor, and providing an igniter to ignite fuel sprayed
from the at least one fuel nozzle; and (b) positioning a mixer
within the combustor downstream of the at least one fuel nozzle and
upstream of the igniter.
13. The method according to claim 12 including solely mixing fuel
with existing exhaust gases for ignition without requiring an
additional atomization air supply.
14. The method according to claim 12 including providing a housing
having an exhaust gas inlet, an exhaust gas outlet, and an internal
wall structure positioned within the housing that defines a
combustion chamber, and including supporting the mixer on the
internal wall structure within the combustion chamber.
15. The method according to claim 12 including forming the mixer to
be defined by an outer peripheral surface with a downstream end
face and an upstream end face with each of the upstream and
downstream end faces providing discontinuous surfaces that
cooperate to reduce the size of fuel droplets flowing through the
mixer from the upstream end face to the downstream end face.
16. The method according to claim 12 wherein the fuel-fired burner
comprises one of a thermal regenerator or thermal enhancer.
17. The method according to claim 16 including configuration the
fuel-fired burner to regenerate a particulate filter.
Description
TECHNICAL FIELD
[0001] The subject invention relates to a fuel-fired burner for a
mobile application, and more particularly to a vehicle exhaust
system utilizing a thermal regenerator or enhancer that has a
mixer.
BACKGROUND OF THE INVENTION
[0002] Exhaust systems are widely known and used with combustion
engines. Some exhaust systems utilize a thermal regenerator (TR) or
a thermal enhancer (TE). A TR is an active unit that enables
regeneration of a diesel particulate filter (DPF) as well as
providing exhaust thermal management under various operating
conditions. A TE is a partial range burner supporting active DPF
regeneration or exhaust thermal management. The TE elevates the
exhaust temperature of exhaust gas to enable regeneration of a DPF
under low temperature conditions or to improve the efficiency of
NOx reduction catalysts.
[0003] The TR and TE include a combustor unit that includes an air
supply line, a fuel supply line and an igniter unit. This
traditional configuration is disadvantageous from a cost and
complexity perspective. Airless TRs and TEs are desirable because
they reduce cost and are less complex due to the elimination of the
air supply components. However, airless TRs and TEs have
significantly larger fuel droplet sizes, which are difficult to
ignite and produce more hydrocarbons.
SUMMARY OF THE INVENTION
[0004] A component assembly includes a combustor that comprises a
fuel-fired burner for a mobile application. In one example, the
fuel-fired burner comprises one of a thermal regenerator or airless
thermal enhancer operating with airless injection and which is
configured to regenerate a particulate filter. A mixer is
positioned within the thermal regenerator or enhancer to improve
ignition by reducing fuel droplet size. A low pressure region is
also created behind the mixer which further assists the ignition
process.
[0005] In one example, at least one fuel nozzle supplies fuel to
the combustor and an igniter ignites fuel sprayed from the fuel
nozzle. The mixer is positioned downstream of the fuel nozzle and
upstream of the igniter and operates to reduce fuel droplet size as
fuel flows through the mixer. Fuel from the fuel nozzle is solely
mixed with existing exhaust gases for ignition without requiring an
additional atomization air supply.
[0006] 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
[0007] FIG. 1 shows a cross-sectional view of a combustor as used
with a thermal regenerator or thermal enhancer.
[0008] FIG. 2 is a schematic view of a mixer positioned within the
combustor.
[0009] FIG. 3 is a schematic view of another example combustor and
mixer.
[0010] FIG. 4 is one example of a mixer.
[0011] FIG. 5 is another example of a mixer.
[0012] FIG. 6 is another example of a mixer.
[0013] FIG. 7 is another example of a mixer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] FIG. 1 shows an exhaust component assembly 10 with a
combustor 12. The combustor 12 comprises any type of combustor
where air-assisted fuel injection is replaced by airless injection.
Examples of such combustors would include vehicle exhaust after
treatment components, auxiliary vehicle passenger compartment
heaters, turbine combustors, etc.
[0015] The exhaust component assembly 10 includes a housing 14
defining an internal cavity 16 and an internal wall structure 18
that defines a combustion chamber 20. The housing 14 includes an
exhaust gas inlet 22 and an exhaust gas outlet 24. Exhaust gases
generated from an engine E flows through any upstream exhaust
components 26 to the exhaust gas inlet 22. Exhaust gases flow
through the exhaust component assembly 10 to the exhaust gas outlet
24 and then on to downstream exhaust system components 28.
[0016] At least one fuel nozzle 30 is supported by the housing 14
to inject/spray fuel from a fuel supply 32 into the combustion
chamber 20. The fuel is sprayed into existing exhaust gases within
the combustion chamber and an igniter 34 (FIG. 2) then ignites the
fuel to increase heat. In one example, the igniter 34 comprises one
or more electrodes 34a, 34b; however, other types of igniters could
also be used.
[0017] The exhaust component assembly 10 comprises a fuel-fired
burner. In one example, the fuel-fired burner comprises one of an
thermal regenerator (TR) or thermal enhancer (TE). A TR is an
active unit that enables regeneration of a diesel particulate
filter (DPF) as well as providing exhaust thermal management under
various operating conditions. A TE is a partial range burner
supporting active DPF regeneration or exhaust thermal management.
The TE elevates the exhaust temperature of exhaust gas to enable
regeneration of a DPF under low temperature conditions or to
improve the efficiency of NOx reduction catalysts. Further, a TR
comprises a combustor system that operates overall an entire engage
map while a TE typically operates only in low and medium speed load
ranges.
[0018] The igniter 34 ignites fuel droplets sprayed by the fuel
nozzle 30 in one of the TR or TE to increase temperatures such that
a particulate filter PF can be regenerated or a NOx reduction
catalyst can be heated up. Ignition of the fuel accomplished
without any type of additional atomization air supply to the
combustor 12. This provides reduced cost and complexity of the
component assembly.
[0019] FIG. 2 shows a TR/TE that incorporates a mixer 40 to improve
ignition. In the airless configurations discussed above, fuel
sprayed by the nozzle tends to include large droplet spray 42. The
mixer 40 is positioned within the TR/TE downstream of the fuel
nozzle 30 and upstream of the igniter 34. The mixer 40 is defined
by an outer peripheral surface 44 with a downstream end face 46 and
an upstream end face 48. The downstream 46 and upstream 48 end
faces provide discontinuous surfaces that cooperate to reduce the
size of fuel droplets flowing through the mixer 40 from the
upstream end face 46 to the downstream end face 48. Fuel exiting
the mixer 40 is comprised of a fine mist (very small droplets) as
indicated at 50. This mist 50 is significantly easier to ignite
than the large droplet spray 42.
[0020] Examples of different mixers 40 are shown in FIGS. 4-7. FIG.
4 shows an example of a wire mesh mixer 40a having an outer ring 52
with wire mesh supported within the ring 52 to provide the
discontinuous surfaces at the upstream 48 and downstream 46 end
surfaces.
[0021] FIG. 5 shows an example of a vane mixer 40b having an outer
ring 54 and cross-members 56 that support a plurality of vanes 58.
The vanes are orientated at various different angles and positions
to provide the discontinuous surfaces at the upstream 48 and
downstream 46 end surfaces.
[0022] FIG. 6 shows an example of a commercial mixer 40c that
includes an upper member 60, a lower member 62, and a center plate
64 positioned between the upper 60 and lower 62 members. The upper
member 60, lower member 62, and center plate 64 include various
contoured surfaces 66 and removed sections 68 that cooperate to
provide the discontinuous surfaces at the upstream 48 and
downstream 46 end surfaces.
[0023] FIG. 7 shows an example of a mixer baffler 40d that includes
a large plate portion 70 with an opening 72, a small plate portion
74, and a plurality of connecting members 76 that connect the large
plate portion 70 to the small plate portion 74. The connecting
members 76 extend in different directions and at different angles
to provide the discontinuous surfaces at the upstream 48 and
downstream 46 end surfaces.
[0024] It should be understood that the examples set forth in FIGS.
4-7 are not the only mixers that can be utilized within the TR/TE.
Any type of mixer element could be used. Further, any of the mixers
shown can be used in either the TE or TR and can be used in any of
the different exhaust inlet/outlet configurations, which will be
discussed below.
[0025] FIG. 1 shows one example exhaust inlet/outlet configuration.
In this example, the internal wall structure 18 is connected at one
end to the housing 14 with a first end plate 80 and is connected at
an opposite end to the housing 14 with an enlarged shroud 82. The
fuel nozzle 30 extends through the first end plate 80 into the
combustion chamber 20. The fuel nozzle 30 defines a nozzle axis A1
that extends along a length of the fuel nozzle 30. The exhaust gas
inlet 22 is mounted through a wall of the housing 14 at a position
between the first end plate 80 and the shroud 82. The exhaust gas
inlet 22 defines an exhaust gas flow axis A2 that is non-parallel
to the nozzle axis A1.
[0026] Exhaust gas enters through the inlet 22 and hits an outer
surface of the internal wall structure 18, which include a
plurality of openings 84 that allow exhaust gas to enter the
combustion chamber 20. The mixer 40 mixes the exhaust gas and the
fuel droplets to produce the mist that is ignited by the igniter
34. As discussed above, this occurs without any additional air
supply to the combustion chamber 20. Exhaust gas then flows from
the combustion chamber, and/or through openings 86 in the shroud
82, to the exhaust gas outlet 24.
[0027] FIG. 3 shows another example inlet/outlet configuration. In
this example, the nozzle axis A1 and the exhaust gas flow axis A2
are parallel to each other. As such, the exhaust gas inlet 22 is
positioned at the same end as the fuel nozzle 30. It should be
understood FIGS. 1 and 3 are only examples, and that other
inlet/outlet configurations could also be used.
[0028] In any of the configurations discussed above, the mixer 40
serves to significantly reduce the size of fuel droplets within the
combustion chamber 20. These smaller droplets are more easily mixed
with the exhaust gases, and are therefore easier to ignite. In
addition, by positioning the mixer 40 downstream of the fuel nozzle
30 and upstream of the igniter 34, a lower pressure region is
created at the upstream side of the mixer that also improves
ignition and flame stability.
[0029] 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.
* * * * *