U.S. patent application number 12/179854 was filed with the patent office on 2009-02-12 for burner for a combustor of a turbogroup.
This patent application is currently assigned to ALSTOM TECHNOLOGY LTD. Invention is credited to Urs Benz, Thorsten Motzkus, Carlos Riemer.
Application Number | 20090042154 12/179854 |
Document ID | / |
Family ID | 40227077 |
Filed Date | 2009-02-12 |
United States Patent
Application |
20090042154 |
Kind Code |
A1 |
Riemer; Carlos ; et
al. |
February 12, 2009 |
BURNER FOR A COMBUSTOR OF A TURBOGROUP
Abstract
A burner for a combustor of a turbogroup is provided. The burner
includes a burner body, an outlet flange, and a plenum which is
exposed, or can be exposed, to admission of cooling medium. In
order to improve the cooling of the outlet flange, a flow passage
and a supply passage are formed. The flow passage and the supply
passage are arranged so that the cooling medium from the plenum
enters the flow passage, is transferred from the flow passage into
the supply passage, and is discharged from the supply passage
through holes into a burner interior.
Inventors: |
Riemer; Carlos;
(Schleinikon, CH) ; Motzkus; Thorsten;
(Baden-Daettwil, CH) ; Benz; Urs; (Gipf-Oberfrick,
CH) |
Correspondence
Address: |
Volpe and Koenig, P.C.;Dept. Alstom
30 South 17th Street, United Plaza, Suite 1600
Philadelphia
PA
19103
US
|
Assignee: |
ALSTOM TECHNOLOGY LTD
Baden
CH
|
Family ID: |
40227077 |
Appl. No.: |
12/179854 |
Filed: |
July 25, 2008 |
Current U.S.
Class: |
431/187 |
Current CPC
Class: |
F23R 3/286 20130101;
F23R 2900/03041 20130101 |
Class at
Publication: |
431/187 |
International
Class: |
F23C 7/00 20060101
F23C007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 7, 2007 |
DE |
102007037291.6 |
Claims
1. A burner for a combustor of a turbogroup, comprising a burner
body (2) enclosing a burner interior (5) and at an outlet end (6)
thereof has an outlet port (7) by which the burner interior (5)
communicates with a combustion chamber (8) of the combustor, and
which includes a plurality of holes (9) for a cooling medium; an
outlet flange (3) arranged at the outlet end (6) and surrounding
the outlet opening (7), and by which the burner body (2) is
fastened, on the combustor, and which has a combustion chamber side
(10) which delimits the combustion chamber (8); a plenum (4)
enclosing the burner body (2) and which is exposable to admission
of cooling medium; a flow passage (13), which is open to the plenum
(4), is formed on a plenum side (11) of the outlet flange (3) that
faces the plenum (4); a supply passage (15), which at one end
communicates with the flow passage (13) and which at the other end
is closed, and which between its ends communicates with a plurality
of holes (9) of the burner body (2), is formed on an outer side
(14) of the burner body (2) that faces the plenum (4), the flow
passage (13) and the supply passage (15) are arranged so that
cooling medium from the plenum (4) enters the flow passage (13), is
transferred from the flow passage (13) into the supply passage
(15), and is discharged from the supply passage (15) through the
plurality of holes (9) into the burner interior (5).
2. The burner as claimed in claim 1, wherein the flow passage (13)
at one end communicates with the supply passage (15) and at the
other end is open to the plenum (4).
3. The burner as claimed in claim 1, wherein the flow passage (13)
at one end communicates with the supply passage (15), at the other
end is closed, and between its ends has inlet openings (19) which
communicate with the plenum (4).
4. The burner as claimed in claim 3,wherein the inlet openings (19)
are arranged for creating an impingement cooling of the outlet
flange (3) on its plenum side (11).
5. The burner as claimed in claim 1, wherein a flow guide plate
(21) is arranged in a transition region (20) in which the flow
passage (13) merges into the supply passage (15), and deflects the
flow which issues from the flow passage (13) for entering the
supply passage (15).
6. The burner as claimed in claim 1, wherein the supply passage
(15) only extends in an outlet-side end region (22) of the burner
body (2).
7. The burner as claimed in claim 1, wherein in the region of the
supply passage (15) the number of holes per area unit in the burner
body (2) is greater than outside it.
8. The burner as claimed in claim 1, wherein the flow passage (13)
encompasses the burner body (2) in an annular manner along the
outlet flange (3) and guides the cooling medium in a radial
direction with regard to a longitudinal center axis of the burner
(1).
9. The burner as claimed in claim 1, wherein the supply passage
(15) encompasses at least an outlet-side end region (22) of the
burner body (2) in an annular manner and guides the cooling medium
in an axial direction with regard to a longitudinal center axis of
the burner (1).
10. The burner as claimed in claim 1, wherein the flow passage (13)
and the supply passage (15) are formed with a guide plate
arrangement (23) which is arranged in the plenum (4) on the outer
side (14) of the burner body (2) and on the plenum side (11) of the
outlet flange (3).
Description
FIELD OF INVENTION
[0001] The present invention relates to a burner for a combustor of
a turbogroup, especially for a turbogroup with sequential
combustion for use in a power generating plant.
BACKGROUND
[0002] A burner customarily has a burner body which encloses a
burner interior and which at an outlet end has an outlet port
through which the burner interior communicates with a combustion
chamber of the combustor. Burners for use in plants with sequential
combustion, which are subjected to high inlet temperatures, as a
rule, have an effusion cooling by which cooling of the burner body
can be realized during operation of the burner.
[0003] In the case of an effusion cooling, the respective cooling
medium, as a rule cooling air or cooling vapor, passes through
effusion cooling holes through a wall of the body which is to be
cooled. In a burner, the cooling medium which enters the burner
interior or combustion chamber interior via the cooling holes
during the effusion cooling mixes with the gas mixture which is
flowing there.
[0004] In addition, a burner customarily has an outlet flange which
is arranged at the outlet end of the burner body and surrounds the
outlet port of the burner body, and by which the burner body is
fastened on the combustor, and which has a combustor side which
delimits the combustion chamber. In addition, a burner customarily
comprises a plenum which encloses the burner body and which is
exposed to admission of cooling medium during operation of the
burner.
[0005] During operation of the burner, the outlet flange on its
combustor side is subjected to the heat of the combustion chamber.
In cooling the outlet flange, it is customary to also provide the
outlet flange with a multiplicity of holes which enable an effusion
cooling of the outlet flange. Depending upon combustion chamber
configuration, a recirculation flow can form in the combustion
chamber downstream of the outlet port of the burner, which leads to
a flame front which is stable to a greater or lesser degree. It has
been shown that the cooling medium, which enters the combustion
chamber during the effusion cooling of the outlet flange, leads to
a cooling of the backflow vortex with implications on the flame
temperature and the flame stability. As a result, undesirable
pressure pulsations ensue and carbon monoxide formation and
increased nitrogen oxide emissions occur.
SUMMARY
[0006] The invention relates to a burner for a combustor of a
turbogroup. The burner includes a burner body enclosing a burner
interior and at an outlet end (6) thereof the burner body has an
outlet port by which the burner interior communicates with a
combustion chamber of the combustor. The burner body also includes
a plurality of holes for a cooling medium. The burner also includes
an outlet flange arranged at the outlet end and surrounding the
outlet opening, and by which the burner body is fastened on the
combustor. The flange has a combustion chamber side which delimits
the combustion chamber. The burner also includes a plenum enclosing
the burner body and which is exposable to admission of cooling
medium. A flow passage, which is open to the plenum, is formed on a
plenum side of the outlet flange that faces the plenum. A supply
passage is also included, which at one end communicates with the
flow passage and which at the other end is closed. The supply
passage, between its ends, communicates with a plurality of holes
of the burner body, and is formed on an outer side of the burner
body that faces the plenum. The flow passage and the supply passage
are arranged so that cooling medium from the plenum enters the flow
passage and is transferred from the flow passage into the supply
passage, and is discharged from the supply passage through the
plurality of holes into the burner interior.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Preferred exemplary embodiments of the invention are
represented in the drawings and are explained in more detail in the
subsequent description, wherein like designations refer to the
same, or similar, or functionally the same components. In the
drawing, schematically in each case,
[0008] FIG. 1 shows a simplified basic sectional view of a
burner,
[0009] FIG. 2 shows an enlarged view of a detail of the burner
which is identified by II in FIG. 1,
[0010] FIG. 3 shows a view as in FIG. 2, of another embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Introduction to the Embodiments
[0011] The invention is based on the general idea of cooling the
outlet flange on a plenum side which faces the plenum by
impingement with cooling medium, wherein the cooling medium is then
used for achieving an effusion cooling of the burner body. By this
course of action, an effusion cooling of the outlet flange can
basically be reduced or completely dispensed with. The interaction
with the reaction zone in the combustion chamber is reduced as a
result. The pressure pulsations and also the pollutant emissions
are reduced accordingly. Providing effusion cooling holes can be
dispensed with, the wall thicknesses of the outlet flange can be
reduced, which on the one hand lowers the production costs for the
outlet flange and on the other hand reduces the temperature
gradient in the outlet flange, which extends its service life.
[0012] In the case of the invention, the impingement of the plenum
side of the outlet flange is achieved by a flow passage being
formed on the plenum side, which communicates with the plenum. The
use of cooling medium for the effusion cooling of the burner body
is realized by a supply passage which communicates with the flow
passage and into which, or on which, open a plurality of holes of
the burner body. By a corresponding arrangement and design of the
flow passage and of the supply passage, conditions can be created
under which cooling medium from the plenum enters the flow passage,
subjects the plenum side of the burner body to impingement with
cooling medium, and as a result convectively cools it. From the
flow passage, the cooling medium can then transfer into the supply
passage and discharge therefrom through the cooling holes.
[0013] In the case of an advantageous development, the flow passage
at one end can communicate with the connecting passage, and at the
other end can be arranged open to the plenum. The cooling medium,
which especially reaches the plenum at an increased pressure, can
therefore penetrate into the flow passage through the open end. The
cooling medium then flows through the flow passage and so reaches
the supply passage. In doing so, the cooling medium flows past the
plenum side of the outlet flange and brings about a convection
cooling there. Since the flow is established as a result of the
pressure ratios, in this case it is a forced convection
cooling.
[0014] In the case of another embodiment, the flow passage at one
end can communicate with the supply passage, but at the other end
can be closed and between its ends can have inlet openings which
communicate with the plenum. In the case of this type of
construction, the plenum side of the outlet flange can be subjected
to impingement with cooling medium at the same time over a larger
area, as a result of which the cooling action is intensified. In
the case of an especially advantageous development, the inlet
openings can be arranged so that they bring about an impingement
cooling of the outlet flange on the plenum side. The inflow with
cooling medium against the outlet flange on its plenum side is
carried out in this case by a correspondingly selected orientation
of the inlet openings which is preferably essentially perpendicular
to the plenum side. Such an impingement cooling can bring about an
especially effective cooling.
[0015] Further important features and advantages of the burner
according to the invention result from the dependent claims, from
the drawings, and from the associated figure description with
reference to the drawings.
Detailed Description
[0016] FIG. 1 comprises a burner 1, which is only partially shown
here, a burner body 2, an outlet flange 3, and also a plenum 4
accordingly. The burner 1 in this case is a component part of a
combustor, which is not referred to in detail here, particularly of
a turbogroup. A combustor customarily has a plurality of such
burners 1 which for example can be arranged annularly.
[0017] The burner body 2 encloses a burner interior 5. The burner
body 2, as here, can be designed in the shape of a prism. A
cylindrical or conical design is also conceivable. Furthermore, the
burner body 2 can comprise two or more half-shell bodies which are
arranged in a symmetrically and eccentrically offset manner to each
other with regard to a longitudinal center axis of the burner 1. At
an outlet end 6, the burner body 2 has an outlet port 7 through
which the burner interior 5 can communicate with a combustion
chamber 8 of the combustor. The burner body 2 has a plurality of
holes 9, which are shown in FIGS. 2 and 3. These holes penetrate
the burner body 2. In particular, the aforementioned holes 9 can be
designed as effusion cooling holes. According to FIGS. 2 and 3, the
holes 9 are oriented in an inclined manner in relation to a
longitudinal center axis of the burner 1, specifically so that
cooling gas, which enters the burner interior 5 through the holes
9, has an axial component which points in the direction of the
combustion chamber 8.
[0018] The outlet flange 3 delimits the combustion chamber 8. It is
arranged at the outlet end 6 of the burner body 2 and surrounds the
outlet port 7. The outlet flange 3 is welded onto the outlet end 6,
for example. By the outlet flange 3, the burner body 2 can be
fastened on the combustor. The outlet flange 3 has a combustion
chamber side 10 which faces the combustion chamber 8, and also a
plenum side 11 which faces the plenum 4.
[0019] The plenum 4 encloses the burner body 2 and is subjected to
admission of cooling gas during operation of the burner 1.
According to FIG. 1, the burner 1 can also be equipped with a lance
12 which in this case projects radially through the burner body 2
into the burner interior 5 and then extends axially and centrally
within the burner interior 5. Via the lance 12, fuel can be
introduced into the burner interior 5 or into the combustion
chamber 8 in a conventional manner.
[0020] In accordance with FIG. 2 and 3, the burner 1 according to
the invention is equipped with a flow passage 13 on the plenum side
11 of the outlet flange 3 and is open to the plenum 4. Furthermore,
a supply passage 15 is formed on an outer side 14 of the burner
body 2 which faces the plenum 4. This supply passage 15 at one end
communicates with the flow passage 13, and at the other end 16 is
closed. Between its ends, the supply passage 15 communicates with a
plurality of holes 9 of the burner body 2. That is to say, the
supply passage 15 is positioned so that it extends across a
plurality of holes 9 of the burner body 2. According to the
invention, the flow passage 13 and the supply passage 15 are now
matched to each other so that during operation of the burner 1 a
defined cooling gas flow is created. The cooling gas flow in this
case is indicated by arrows which are not referred to in detail.
The cooling gas in this case flows from the plenum 4 into the flow
passage 13 and can transfer from the flow passage 13 into the
supply passage 15. From the supply passage 15, the cooling gas
reaches the burner interior 5 via the holes 9.
[0021] In the case of the embodiment which is shown in FIG. 2, the
flow passage 13 is arranged so that at one end 17 it is open to the
plenum 4, while at the other end it communicates with the supply
passage 15. In this arrangement, a cooling gas flow which is
parallel to the plenum side 11 is created. This creates a
convection cooling of the outlet flange 3. In contrast to this, in
the case of the embodiment which is shown in FIG. 3, the flow
passage 13 at one end is reconnected to the supply passage 15 in a
communicating manner. At the other end 18, it is closed. For that
reason, between its ends it has inlet openings 19 which communicate
with the plenum 4. As a result, cooling gas can enter the flow
passage 13 by the inlet openings 19. In the case of the preferred
embodiment which is shown in FIG. 3, the inlet openings 19 are
oriented so that as a result an impingement cooling of the outlet
flange 3 on its plenum side 11 can be realized. In the example, the
inlet openings 19 are arranged so that a virtually perpendicular
inflow against the plenum side 11 of the outlet flange 3 can be
formed. Since the cooling gas in the flow passage 13 follows the
pressure drop, a force-guided convection flow, which feeds the
cooling gas to the supply passage 15 and consequently to the holes
9 of the burner body 2, is also formed in the case of this
embodiment.
[0022] A transition region 20, in which, in the case of a preferred
embodiment, a flow guide plate 21 can be arranged, is formed at the
transition between the flow passage 13 and the supply passage 15.
Such a flow guide plate 21 is provided in the case of the
embodiment which is shown in FIG. 2. The flow guide plate 21 brings
about a deflection of the cooling gas flow which issues from the
flow passage 13 in the direction of the supply passage 15 so that
the cooling gas flow can enter the supply passage 15 with reduced
pressure loss. This is especially advantageous when, as in this
case, the flow passage 13 extends essentially radially with regard
to the longitudinal center axis of the burner 1, that is to say
brings about a radial guiding of the cooling gas in the flow
passage 13. In contrast to this, the supply passage 15 is oriented
axially with regard to the longitudinal center axis of the burner
1, that is to say is oriented so that it brings about a guiding of
the cooling gas in the axial direction.
[0023] In the case of the embodiments shown here, the supply
passage 15 extends in each case exclusively in an outlet-side end
region 22 of the burner body 2, which is symbolized in FIGS. 2 and
3 by a brace. The end region 22 comprises the outlet end 6 and for
example extends over a third or over half of the overall length of
the burner body 2.
[0024] Embodiments in which in the region of the supply passage 15,
that is to say especially in the end region 22, a hole density in
the burner body 2 is greater than outside the region of the burner
body 2 which is covered by the supply passage 15 are preferred in
this case. The number of holes per area unit is understood by "hole
density" in this case. For example, it can be seen in FIG. 2 that
the distances of adjacent holes 9 in the end region 22 which is
covered by the supply passage 15 are greater than in the region of
the burner body 2 which adjoins the end region 22.
[0025] The flow passage 13, in the case of the embodiments which
are shown here, encompasses the burner body 2 along the plenum side
11 of the outlet flange 3. Furthermore, the supply passage 15, in
the case of the embodiments which are shown here, encompasses at
least the outlet-side end region 22 of the burner body 2.
[0026] In the case of the embodiments shown here, a guide plate
arrangement 23 is provided for realizing the flow passage 13 and
the supply passage 15. This guide plate arrangement is arranged in
the plenum 4 on the outer side 14 of the burner body 2 and also on
the plenum side 11 of the outlet flange 3. For example the guide
plate arrangement 23 can comprise at least one shell-shaped plate
body which is mounted on the burner body 2 on the outside and
essentially follows its contour. In addition, the guide plate
arrangement 23 can comprise a further flow guide plate 24 which
serves as the boundary to the plenum 4 and brings about the guiding
of the cooling gas to the respective inlet side of the flow passage
13. Where the existing structure allows it, this function can also
be entirely or partially undertaken by a support component. By the
proposed type of construction, an intensive cooling of the outlet
flange 3 can be achieved. In this case, an effusion cooling of the
outlet flange 3 can especially be dispensed with. At least the
number of effusion cooling holes in the outlet flange 3 can be
significantly reduced. As a result of the reduced or avoided
effusion cooling of the outlet flange 3, interactions in the
combustion chamber 8 between cooling gas and combustion reaction
can be minimized which correspondingly reduces the formation of
pressure pulsations and the occurrence of CO emissions and NO.sub.x
emissions. Furthermore, the outlet flange 3, on its combustion
chamber side 10 which delimits the combustion chamber 8, can be
provided with a reinforced thermal barrier coating 25 which enables
an intensive thermal protection for the outlet flange 3. In the
case of an effusion cooling in the outlet flange 3, such a barrier
coating 25 would be repeatedly interrupted because of the effusion
holes and would not be able to be applied so thickly. Furthermore,
the material thickness of the outlet flange 3 can be reduced since
a minimum thickness which is required for realizing effusion
cooling passages no longer has to be observed. The reduced wall
thickness improves the temperature distribution inside the outlet
flange 3 and reduces its thermal load.
[0027] Inside the flow passage 13 or inside the supply passage 15,
for example turbulators can also be arranged in order to boost the
cooling action of the convection cooling inside the respective
passage 13, 15.
[0028] By selection of the cross sections and also of the cross
sectional variations of the passages 13, 15, the cooling demand can
be adapted to local requirements. The same also applies to the
number, the density and the distribution of the effusion cooling
holes 9 inside the region of the burner 2 which is covered by the
supply passage 15.
List of Designations
[0029] 1 Burner [0030] 2 Burner body [0031] 3 Outlet flange [0032]
4 Plenum [0033] 5 Burner interior [0034] 6 Outlet end [0035] 7
Outlet port [0036] 8 Combustion chamber [0037] 9 Effusion cooling
hole [0038] 10 Combustion chamber side [0039] 11 Plenum side [0040]
12 Fuel lance [0041] 13 Flow passage [0042] 14 Outer side [0043] 15
Supply passage [0044] 16 Closed end [0045] 17 Open end [0046] 18
Closed end [0047] 19 Inlet opening [0048] 20 Transition region
[0049] 21 Flow guide plate [0050] 22 End region [0051] 23 Guide
plate arrangement [0052] 24 Flow guide plate [0053] 25 Thermal
barrier coating
* * * * *