U.S. patent application number 14/241149 was filed with the patent office on 2014-11-27 for combustion chamber for a gas turbine plant.
This patent application is currently assigned to SIEMENS AKTIENGESELLSCHAFT. The applicant listed for this patent is Bernd Prade, Japp Van Kampen. Invention is credited to Bernd Prade, Japp Van Kampen.
Application Number | 20140345283 14/241149 |
Document ID | / |
Family ID | 46690501 |
Filed Date | 2014-11-27 |
United States Patent
Application |
20140345283 |
Kind Code |
A1 |
Prade; Bernd ; et
al. |
November 27, 2014 |
COMBUSTION CHAMBER FOR A GAS TURBINE PLANT
Abstract
A combustion chamber (1) for a gas turbine plant, has a
combustion chamber wall (10), which is flowed through by combustion
gases in the direction of a downstream expansion turbine, the
chamber wall (10) has a device (20) for damping thermoacoustic
oscillations caused by the combustion gases. At least one resonator
tube (22), interacts with the resonator volume (21) and opens out
into the combustion chamber (1) with its mouth (M) opposite from
the resonator volume (21) in the combustion chamber inner wall
(10). At least one feed opening (23, 23', 23'') for sealing air for
sealing the resonator tube mouth (M) is introduced into the
combustion chamber (1) from a compressor plenum (2), surrounding
the combustion chamber. The at least one first feed opening (23',
23'') is provided in a region of the combustion chamber wall (10)
close to the resonator tube mouth (M) and is aligned such that the
sealing air (S) through the feed opening (23', 23'') flows over the
resonator mouth (M).
Inventors: |
Prade; Bernd; (Mulheim,
DE) ; Van Kampen; Japp; (Roermond, NL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Prade; Bernd
Van Kampen; Japp |
Mulheim
Roermond |
|
DE
NL |
|
|
Assignee: |
SIEMENS AKTIENGESELLSCHAFT
Munchen
DE
|
Family ID: |
46690501 |
Appl. No.: |
14/241149 |
Filed: |
August 14, 2012 |
PCT Filed: |
August 14, 2012 |
PCT NO: |
PCT/EP2012/065849 |
371 Date: |
February 26, 2014 |
Current U.S.
Class: |
60/725 |
Current CPC
Class: |
F23R 3/002 20130101;
F23R 2900/03042 20130101; F23R 3/06 20130101; F23R 3/16 20130101;
F23M 20/005 20150115; F23R 2900/00014 20130101 |
Class at
Publication: |
60/725 |
International
Class: |
F23R 3/16 20060101
F23R003/16 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 1, 2011 |
DE |
102011081962.2 |
Claims
1-6. (canceled)
7. A combustion chamber for a gas turbine plant, the combustion
chamber includes: a combustion chamber wall, through which
combustion gases flow in a direction of a following gas turbine;
the combustion chamber wall having a damping device for the damping
of thermoacoustic vibrations caused by combustion gases, the
damping device comprising at least one Helmholtz resonator which is
configured such that a resonator volume thereof lies on a side of
the combustion chamber wall that faces away from an inner wall of
the combustion chamber; the resonator has at least one resonator
tube, the tube co-operates with the resonator volume, and the
resonator tube has a mouth lying opposite the resonator volume in
the combustion chamber inner wall and exits into the combustion
chamber; at least one delivery port configured for entry of barrier
air into the combustion chamber in such manner as for barring the
resonator tube mouth the barrier air from a compressor plenum that
surrounds the combustion chamber, the plenum being of a compressor
that is positioned upstream of the combustion chamber, and the at
least one first delivery port being provided in a region of the
combustion chamber wall near the mouth of the at least one
resonator tube and the at least one first delivery port being
oriented such that the barrier air flowing through the at least one
first delivery port flows over the resonator tube mouth; the
resonator tube mouth is set back in the combustion chamber wall
with respect to the combustion chamber inner wall and into an area
set back away from the combustion chamber, the at least one first
delivery port is oriented and configured for injecting the barrier
air virtually parallel to the flow direction of the combustion
gases and flows over the setback resonator tube mouth.
8. The combustion chamber as claimed in claim 7, wherein the
resonator comprises a plurality of resonator tubes and the
resonator tubes have their respective mouths oriented such that the
barrier air of the delivery port flows over the setback resonator
tube mouths of the plurality of resonator tubes.
9. The combustion chamber as claimed in claim 8, further comprising
a second one of the delivery ports directed opposite to the first
one of the delivery ports, the second one of the delivery ports
being oriented such that the barrier air through the second one of
the ports is injected virtually parallel to and opposite to the
flow direction of combustion gases in the combustion chamber and
the barrier air through the second ones of the delivery ports flows
over the setback resonator tube mouths.
10. The combustion chamber as claimed in claim 7, wherein the
delivery port is oriented in the combustion chamber wall such that
the delivery port axis is inclined with respect to the resonator
tube mouth.
11. The combustion chamber as claimed in claim 7, wherein the
combustion chamber inner wall has in a region of setback areas
overlaps with the setback areas of the combustion chamber wall.
12. A gas turbine plant with a compressor for the compression of
sucked-in air, with the combustion chamber as claimed in claim 7
following the compressor; and the plant having a burner for
admixing fuel and for the combustion of the fuel/air mixture, and
an expansion turbine which follows the burner and which converts
the combustion exhaust gases of the burnt fuel/air mixture into
mechanical energy.
Description
[0001] The invention relates to a combustion chamber for a gas
turbine plant according to the preamble of claim 1 and to a
correspondingly designed gas turbine plant according to claim
7.
[0002] Gas turbine plants are composed essentially of a compressor,
of a combustion chamber with a burner and of an expansion turbine.
In the compressor, sucked-in air is compressed before it is mixed
with fuel in the combustion chamber in the following burner
arranged in the compressor plenum, and this mixture is burnt. The
expansion turbine following the combustion chamber then extracts
thermal energy from the combustion exhaust gases which have
occurred in the burner and converts this into mechanical energy. A
generator capable of being coupled to the expansion turbine can
convert this mechanical energy into electrical energy for current
generation.
[0003] Nowadays, gas turbine plants, like other current-generating
plants, too, must have as low pollutant emissions as possible in
all load ranges, while working at maximum efficiency. Major
influencing variables are in this case the mass flows, set in the
combustion chamber of the burner, of the fuel, of the compressed
air and of the cooling air delivered for cooling the burner
components. However, the limitation of pollutant emissions, in
particular of NOx and unburnt fuel mostly in the form of CO, may
lead to a minimization of the quantity of cooling air or of leakage
air in the combustion chamber and consequently to parasitic flows
which have an acoustically damping effect. Furthermore, under the
boundary condition of limiting the emissions, an increase in
efficiency usually also entails an increase in the volumetric heat
release density in the combustion chamber. The two together, that
is to say a reduction in acoustic damping and an increase in the
heat release density in the combustion chamber, lead to a higher
risk that thermoacoustically induced vibrations commence. However,
thermoacoustic vibrations of this kind in the combustion chamber
present a problem in the design and, in particular, in the
operation of gas turbine plants.
[0004] To reduce such thermoacoustic vibrations, Helmholtz
resonators, which are composed of at least one resonator tube and
of a resonator volume, are employed nowadays for damping. Helmholtz
resonators of this kind damp the amplitude of vibrations with the
Helmholtz frequency in specific frequency ranges as a function of
the cross-sectional area and the length of the resonator tube and
of the resonator volume. Helmholtz resonators as damping devices
for limiting thermoacoustic vibrations in combustion chambers are
known, for example, from EP 1 605 209 A1 or U.S. 2007/0125089
A1.
[0005] FIG. 1 shows, for example, the arrangement, known from U.S.
2007/0125089 A1, of Helmholtz resonators 20 on a ring of the
combustion chamber wall 10 transversely to the flow direction. The
combustion chamber wall 10 is in this case of tubular form and
separates the combustion chamber 1 from the surrounding compressor
plenum 2. The perforations 22 in the combustion chamber wall 10
between resonator volume 21 and combustion chamber 1 form the
resonator tubes of the Helmholtz resonators. In this case, as
illustrated in FIG. 1, each Helmholtz resonator may have a
plurality of resonator tubes or else only a single resonator tube.
So that none of the hot combustion gases from the combustion
chamber 1 are introduced into the Helmholtz resonators 20,
additional ports for the delivery of barrier air are provided. In
the exemplary embodiment shown in FIG. 1, these delivery ports 23
are arranged on that wall of the resonator volume 21 which lies
opposite the resonator tubes 22. These ports 23 make it possible
that compressed air S can flow out of the compressor plenum 2
surrounding the combustion chamber into the resonator volume 21 and
from there, via the resonator tubes 22, into the combustion chamber
1, thus barring the penetration of hot combustion gases into the
resonator tubes 22.
[0006] However, Helmholtz resonators with deliveries of barrier air
via the volume body have the disadvantage that this barrier air
flowing through the Helmholtz resonator can diminish its damping
properties such that instabilities may occur when the burner is in
operation. In particular, in such systems, even a marked reduction
in the damping properties has been found with an increasing
velocity of the barrier air flowing through the resonator tubes.
However, a specific barrier air velocity in the resonator tubes is
necessary in order to bring about a reliable barrier effect with
respect to the combustion gases entering the resonator from the
combustion chamber. Moreover, this type of delivery of barrier air
makes it necessary to introduce from the compressor plenum a large
fraction of air which, however, is then no longer available for
actual combustion so as to reduce the flame temperature. This, in
turn, in gas turbine plants operated at their power output limits
for maximum NOx reduction, may bring about a rise in harmful NOx
pollutants, although this is what is precisely to be avoided.
Moreover, the cooler barrier air from the resonators may cause
local instabilities in combustion to occur, thus leading in turn to
increased CO pollutant emission.
[0007] The object of the invention is to provide a combustion
chamber which overcomes the disadvantages described above.
[0008] This object is achieved by means of the combustion chamber
having the features of claim 1.
[0009] Since a combustion chamber designed according to the
preamble of claim 1 and having at least one Helmholtz resonator has
at least one delivery port which is provided in a region of the
combustion chamber wall near the resonator tube mouth of the at
least one resonator tube and is oriented such that the barrier air
flowing through the delivery port flows over the resonator mouth,
the injection, known from the prior art, of barrier air through the
Helmholtz resonator may be dispensed with. Its damping properties
are therefore no longer influenced by the barrier air flowing
through, with the result that reliable damping of thermoacoustic
vibrations is achieved, thus ultimately lengthening the service
life of the combustion chamber and therefore of the entire gas
turbine plant. Moreover, with the barrier air delivery designed
according to the invention, less air from the compressor plenum is
required, as compared with the known versions, so that, overall,
the NOx and CO pollutant emission of the gas turbine plant also
becomes lower.
[0010] Further preferred exemplary embodiments may be gathered from
the subclaims. What is essential in all the combustion chamber
versions is that, with the aid of suitably designed delivery ports,
a barrier film is built up in front of the resonator tube mouths on
the combustion chamber side, and barrier air can thus be used more
effectively as a reliable barrier against the inflow of hot
combustion gases from the combustion chamber into the Helmholtz
resonators, and at the same time the damping properties of the
Helmholtz resonators are not influenced by the barrier air. Gas
turbine plants equipped with such combustion chambers can thus have
as low pollutant emissions as possible in all load ranges, while
working at maximum efficiency.
[0011] The invention, then, will be explained by way of example by
means of the following figures in which:
[0012] FIG. 1 shows diagrammatically a damping device known from
the prior art,
[0013] FIG. 2 shows diagrammatically a first version according to
the invention of a damping device,
[0014] FIG. 3 shows diagrammatically a second version according to
the invention of a damping device,
[0015] FIG. 4 shows diagrammatically a third version according to
the invention of a damping device,
[0016] FIG. 5 shows diagrammatically a fourth version according to
the invention of a damping device.
[0017] Contrary to the known embodiment illustrated in FIG. 1,
according to the invention the barrier air S is not routed through
the damping device 20, but instead delivery ports 23' and/or 23''
are provided and oriented in the combustion chamber wall 10 such
that the barrier air S flowing through the delivery ports 23', 23''
flows over the resonator tube mouth M in the region of the
combustion chamber inner wall virtually in a similar way to film
cooling.
[0018] FIG. 2 shows a first embodiment in which the resonator tube
mouths M are set back in the combustion chamber wall 10 with
respect to the combustion chamber inner wall 10' in a defined area
10'' away from the combustion chamber inner space, and the delivery
port 23' is oriented such that the barrier air S is injected,
virtually parallel to the flow direction of the combustion gases G,
into the space between the area 10'' and the combustion chamber
inner wall 10' such that it flows completely over the setback
resonator tube mouths M of the resonator tubes 22. In this space in
front of these resonator tube mouths M (shown here only for two of
the six resonator tubes), a barrier air film is thus formed which,
even with a low mass flow of barrier air, very effectively prevents
the penetration of hot combustion gases into the Helmholtz
resonator 20. When injection of the barrier air takes place, as
indicated in FIG. 2, through a tubular port 23' in the upstream
side wall in the downstream direction of the combustion gases, the
injected barrier air is entrained by the stream of combustion
exhaust gases and an especially effective barrier film is thus
obtained.
[0019] Since the effective axial distance of film cooling bores is
limited, a second delivery port 23'' lying opposite the first
delivery port 23' may be provided, as indicated in FIG. 3, which is
oriented such that the barrier air S is injected virtually parallel
to and opposite to the flow direction of the combustion exhaust
gases G so that even resonators with a greater extent in the flow
direction can still be barred effectively.
[0020] If, as indicated in FIG. 4, the combustion chamber wall 10
has on the setback area 10'', level with the combustion chamber
inner wall 10', an overlap L with the setback areas 10'', the
extent of the resonators can likewise be increased, without an
additional opposite row of barrier air bores being necessary.
[0021] It is advantageous if, as in FIG. 5, the delivery port 23'
or else other delivery ports, such as, for example, the delivery
port 23'', shown in FIG. 3, is or are arranged in the combustion
chamber wall 10 such that their axis A is inclined with respect to
the resonator tube mouth M. As a result, as well as barring,
additional impact cooling of the resonator wall is achieved, which
may be expedient particularly in regions of the combustion chamber
where an especially large amount of heat is introduced into the
combustion chamber wall.
[0022] FIG. 2 to FIG. 5 show in each case various advantageous
embodiments which individually or else in combination implement the
idea according to the invention, to be precise that of ensuring an
efficient and reliable barrier against the penetration of hot gases
from the combustion chamber into the damping devices without the
passage of barrier air via the damping device. Moreover, the
invention also embraces embodiments in which, contrary to the
exemplary embodiments shown, the deliveries of barrier air lie so
near to the resonator tube mouths that they form a direct component
of each of the resonator tube mouths and are thus virtually
integrated into each resonator tube mouth.
* * * * *