Information
-
Patent Grant
-
6210152
-
Patent Number
6,210,152
-
Date Filed
Tuesday, August 24, 199925 years ago
-
Date Issued
Tuesday, April 3, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Lazarus; Ira S.
- Clarke; Sara
Agents
- Burns, Doane, Swecker & Mathis, L.L.P.
-
CPC
-
US Classifications
Field of Search
US
- 431 12
- 431 22
- 431 42
- 431 258
- 431 281
- 431 284
- 431 285
- 431 346
- 431 354
- 060 737
- 060 39826
-
International Classifications
-
Abstract
In a burner for operating a combustor, the former consists essentially of a rotation generator (100), a transition piece following the rotation generator, and a mixing pipe following this transition piece. Transition piece and mixing pipe form the mixing section (220) of the burner and are located upstream from a combustion chamber (30). In the lower part of the mixing pipe is located a pilot burner system (300) which creates, among other things, a stabilization of the flame front, in particular in the transient load ranges, while minimizing pollutant emissions. A sensor (400) installed in the burner detects a flashback of the flame (80), whereupon the fuel quantity of this flame is at least temporarily reduced and at the same time the fuel quantity for the pilot burner is increased in such a way that the total fuel quantity and thus the turbine output remains constant. This measure prevents a destruction of the burner.
Description
FIELD OF TECHNOLOGY
The invention on hand relates to a burner for a heat exchanger according to the preamble of claim
1
. It also relates to a method for operating such a burner.
STATE OF THE ART
Usually, burners of gas turbines are operated in premix mode. Such premix burners are known from EP-B1-0 321 809 and DE-195 47 913.0. By using upstream fuel injection in such premix burners, the fuel is premixed with the air before the combustion takes place. This provides an explosive mixture for the further combustion inside the burner. In general, it can be noted that such new generation burners offer numerous advantages, for example, a stable flame position, lower pollutant emissions (CO, UHC, NOx), minimal pulsations, complete burnout, a larger operating range, good cross-ignition between the various burners, in particular when creating graduated loads, during which case the burners are operated independently from each other, an adaptation of the flame to the corresponding combustor geometry, a compact design, an improved mixing of the flow media, an improved “pattern factor” of temperature distribution in the combustor, i.e., a balanced temperature profile of the combustor flow.
If, however, unforeseen malfunctions occur during operation, this may result in flame instability. Once the flashed-back flame is able to stabilize inside the burner, it burns as a diffusion flame with a very high temperature, at about 1900° C. Within a short time, ranging from 10 to max. 30 seconds, the burner overheats and is destroyed. In any case, the gas turbine must be stopped, inspected, and repaired, resulting in tremendous costs. It was found that, in particular, in prototype gas turbines with new combustion technology or combustion of hydrogen-containing fuels (MBt or LBt gasses) a high risk exists in this regard.
DESCRIPTION OF THE INVENTION
The invention attempts to solve this problem. The invention, as characterized in the claims, is based on the objective of proposing measures for a burner and a process of the initially mentioned type that would maximize flame stability in the burner.
According to the invention it is proposed to provide the burners with a compact, contactless flame monitor in a suitable place.
The essential advantages of the invention are that the sensor installed in the burner reports a flashback of the flame. Then the premix fuel mixture is reduced, and the pilot fuel quantity is simultaneously increased, so that the total fuel quantity, and therefore the turbine output, remains constant. Because of the reduction, i.e., of the premix fuel quantity, the flashback flame can no longer stabilize in the burner; it is inevitably flushed out of the burner. This makes it possible to prevent a destruction of the burner.
Such a sensor or flame monitor can be realized with high-temperature-resistant glass fibers. These fibers are arranged so that their monitoring field covers the areas at risk, but not the pilot and premix flame burning normally. The UV portion (about 300-330 nm) of the radiation measured by the sensor undergoes a spectral analysis with suitable filters. A flashback in the burner can be detected within a matter of milliseconds via the ratio of the intensity at various wavelengths. If the combustor consists of a number of burners, it is possible to determine with suitable data acquisition in which burner the flame flashback has occurred, and suitable measures for eliminating the causes can be taken.
Advantageous and useful further developments of the solution according to the invention are characterized in the remaining claims.
The following is a more detailed discussion of the exemplary embodiments of the invention in reference to the drawings. Any characteristics not essential for the direct understanding of the invention have been ignored. Identical elements have been marked in the various figures with the same reference symbols. The flow direction of the media is indicated with arrows.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1
shows a schematic view of a burner with integrated sensor;
FIG. 2
shows a burner after flashback and with subsequent stabilization of the flame in the burner;
FIG. 3
shows a schematic fuel control sequence over time in case of a flame flashback;
FIG. 4
shows an integral section through a burner designed as a premix burner with a mixing section downstream from a rotation generator and with pilot burners;
FIG. 5
shows a schematic portrayal of the burner according to
FIG. 1
with disposition of the additional fuel injectors;
FIG. 6
shows a perspective drawing of a rotation generator consisting of several segments, sectioned accordingly;
FIG. 7
shows a cross-section through a two-segment rotation generator;
FIG. 8
shows a cross-section through a four-segment rotation generator;
FIG. 9
shows a view through a rotation generator whose segments are profiled in blade-shape;
FIG. 10
shows a variation of the transition geometry between rotation generator and mixing section; and,
FIG. 11
shows a tear-off edge for the spatial stabilization of the flowback zone.
METHODS FOR EXECUTING THE INVENTION, COMMERCIAL USABILITY
FIG. 1
shows a schematic overview of a premix burner, whereby the design of such a burner has been described in detail in
FIGS. 4-11
. Principally, this premix burner consists of a rotation generator
100
, of a mixing section
220
following this rotation generator, whereby a system of pilot burners
300
with corresponding pilot flames
70
act in the combustor
30
following the mixing section
220
. In connection with
FIG. 2
, this
FIG. 1
only strives to explain how the flashback
81
of the premix flame
50
which is shown here by means of the flowback bubble, is detected by sensors
400
, and how remedial measures are initiated immediately. In the process, it is always observed that a back-ignition from the combustor
30
to the fuel injectors
116
takes place. A stabilization of this back-ignited flame
80
in the area of the fuel injectors
116
then can no longer be avoided, whereby in this case a diffusion flame with very high temperatures of approximately 1900° C. is created. This flame inevitably results in a destruction of the burner within a matter of a few seconds. At least one sensor
400
is placed immediately downstream from the fuel injectors
116
and is not supposed to monitor either the premix flame
50
nor the pilot flames
70
, but only those areas at risk. Such a sensor
400
preferably consists of high-temperature-resistant glass fibers which are arranged in such a way that their scan angle
402
covers only those areas at risk. The radiation detected by the sensor is further transmitted
401
and undergoes a spectral analysis with suitable filters. A flashback in the burner can be detected within a matter of milliseconds via the ratio of the intensities at various wavelengths. A suitable data acquisition will make it possible to determine in which burner in the system the flame flashback has occurred, whereby specific measures for eliminating the cause then can be taken.
FIG. 3
shows which measures are initiated following a flame flashback. When notified that a flashback
81
of the flame has taken place, a control
82
immediately manipulates the fuel quantity for the premix flame
50
, which is immediately reduced according to certain criteria. At the same time, a second control
83
is actuated, which increases the fuel quantity for the pilot burner system
300
, i.e., for the pilot flame
70
. The objective of this counter-acting fuel supply is to keep the turbine output constant. By reducing the fuel quantity for the premix flame
50
, the flashed-back flame is no longer able to stabilize in the burner, it is flushed out of the burner, so that the otherwise inevitable destruction of the burner is in this way safely avoided.
FIG. 3
shows the qualitative sequence of the fuel control over time, whereby the flushing out
84
of the flashed-back flame takes place at the extreme points of this control.
This process for the direct detection of a flame flashback can be used for all premix burners based on a rotational flow, regardless of how the burner is geometrically constructed, and regardless of which way the rotational flow is created. In particular, this process can be used for the premix burner according to EP-B1-0 321 809, whereby this publication forms an integral part of this specification at hand.
FIG. 4
shows the overall construction of a burner that can be operated with a rotational flow. Initially, a rotation generator
100
whose design is shown and explained in more detail in reference to the following
FIGS. 5 through 8
is activated. This rotation generator
100
is a conical structure which is impacted repeatedly by a tangentially inflowing combustion air stream
115
. The flow resulting from this is seamlessly fed with the help of a transition geometry located downstream from the rotation generator
100
into a transition piece
200
in such a way that no separation areas can occur there. The configuration of this transition geometry is described in more detail under FIG.
10
. This transition piece
200
is extended on the flow-off side from the transition geometry with a mixing pipe
20
, whereby both parts form the actual mixing section
220
. Naturally, the mixing section
220
may also consist of a single piece, which means that the transition piece
200
and the mixing pipe
20
are then fused to form a single, contiguous structure, whereby the characteristics of each part are preserved. If the transition piece
200
and the mixing pipe
20
are constructed from two parts, these are connected with a bushing ring
10
, whereby the same bushing ring
10
serves on the head side as an anchoring surface for the rotation generator
100
. Such a bushing ring
10
also has the advantage of being able to use different mixing pipes. On the flow-off side of the mixing pipe
20
, the actual combustion chamber
30
of a combustor, which in this case is only symbolized by a flame pipe, is located. The mixing section
220
essentially has the function of providing a defined section downstream from the rotation generator
100
, in which a perfect premixing of fuels of various types can be achieved. This mixing section, i.e., here the mixing pipe
20
, also permits a loss-free guidance of the flow, so that initially no flowback zone or flowback bubble is able to form even in active connection with the transition geometry, so that the mixing quality of all types of fuel can be influenced over the length of the mixing section
220
. However, this mixing section
220
also has another characteristic, namely that the axial speed profile has a distinct maximum on the axis in this mixing section itself, so that a flashback of the flame from the combustor itself should actually be prevented. However, it is correct that with such a configuration this axial speeds decreases towards the wall. In order to prevent a flashback also in this area, the mixing pipe
20
is provided in the flow and peripheral direction with a number of regularly or irregularly distributed bores
21
that have different cross-sections and directions, through which bores a quantity of air flows into the inside of the mixing pipe
20
and induces an increase in the flow speed along the wall in the sense of forming a film. These bores
21
also can be designed so that, in addition, at least an effusion cooling occurs at the inside wall of the mixing pipe
20
. Another possibility for increasing the speed of the mixture within the mixing tube
20
is by constricting the latter's flow cross-section downstream from the transition channels
201
, which form the already mentioned transition geometry, so that the entire speed level inside the mixing pipe
20
is increased. In the figure, these bores
21
extend at an acute angle to the burner axis
60
. The outlet of the transition channels
201
furthermore corresponds to the narrowest flow cross-section of the mixing pipe
20
. Said transition channels
201
therefore bridge the respective cross-section differential without adversely affecting the formed flow.
If the selected measure causes an unacceptable loss of pressure when the pipe flow
40
is guided along the mixing pipe
20
, this can be remedied by providing a diffuser (not shown in the figure) at the end of this mixing pipe. The end of the mixing pipe
20
is therefore followed by a combustor
30
(combustion chamber), whereby a change in cross-section that is a result of a burner front exists between the two flow cross-sections. Only here, a central flame front with a flowback zone that has the characteristics of a bodiless flame retention baffle in relation to the flame front forms. If, during operation, a marginal flow zone forms within this cross-section change in which turbulence separations are created because of the vacuum present there, this results in an increased ring stabilization of the flowback zone. In addition, it must not go unmentioned, that the formation of a stable flowback zone also requires a sufficiently high rotation value in a pipe. If such a rotation value is initially undesired, stable flowback zones can be created by introducing small air flows with strong rotations at the pipe end, for example through tangential openings. In the process it is hereby assumed that the air quantity required for this is about 5 to 20% of the total air quantity. In regard to the design of the burner front at the end of the mixing pipe
20
for stabilizing the flowback zone or flowback bubble, reference is made to the description for FIG.
8
. Regarding the possibility of interfering with a flame flashback, reference is made to
FIGS. 1
to
3
.
A pilot burner system
300
is provided concentrically to the mixing pipe
20
in the area of the latter's outlet. This pilot burner system consists of an inner ring chamber
301
into which flows a fuel, preferably a gaseous fuel
303
. Secondary to this inner ring chamber
301
, a second ring chamber
302
is disposed, into which an air quantity
304
flows. Both ring chambers
301
,
302
have individually designed through-openings in such a way that the individual media
303
,
304
flow as a result of the function into a mutual, subsequent ring chamber
308
. The passage of the gaseous fuel
303
from the ring chamber
301
into the subsequent ring chamber
308
is achieved by a number of peripherally located openings
309
. The flow-through geometry of these openings
309
is such that the gaseous fuel
303
flows with a high mixing potential into the subsequent ring chamber
308
. The other ring chamber
302
terminates in a perforated plate
305
, whereby the bores
310
provided here are designed so that the air quantity
304
flowing through them results in an impact cooling on the bottom plate
307
of the subsequent ring chamber
308
. This bottom plate has the function of a heat shield in relation to the caloric stress from the combustion chamber
30
, so that this impact cooling must be extremely efficient here. After cooling has taken place, this air mixes inside this ring chamber
308
with the inflowing gaseous fuel
303
from the openings
309
of the upstream ring chamber
301
, before this mixture then flows off into the combustion chamber
30
through a number of bores
306
on the combustion chamber side. The mixture flowing off here burns in the form of a premixed diffusion flame with minimized pollutant emissions and then forms for each bore
306
a pilot burner that acts into the combustion chamber
30
and which ensures a stable operation.
An ignition device
311
which in the subsequent ring chamber
308
brings about the ignition of the mixture formed there is conducted through the secondary ring chamber
302
through which an air stream flows. This conduction of the ignition device
311
on the one hand does not require any additional construction measures, and on the other hand this ignition device
311
is continuously cooled by the air
304
which flows there anyway. This is very important, because temperatures of approximately 1000° C. are reached at the tip of a glow igniter
2
pin. But since the operation proposed here requires only a low voltage, but high amps, the susceptibility of the ignition device to condensate water precipitation is eliminated. The arrangement of the glow igniter pin—whereby the use of a spark plug would also be possible—inside the burner results in a low thermal stress on the respective ignition device
311
, so that no additional cooling is necessary and leaks are prevented.
FIG. 5
shows a schematic view of the burner according to
FIG. 4
, whereby here reference is made specifically to the flow around a centrally located fuel nozzle
103
(see
FIG. 6
) and to the action of fuel injectors
170
. The function of the remaining main components of the burner, i.e., rotation generator
100
and transition piece
200
are described in more detail below in reference to the figures. The fuel nozzle
103
is enclosed at a distance with a ring
190
into which a number of peripherally disposed bores
161
have been integrated, through which an air quantity
160
flows into an annular chamber
180
and there flows around the fuel lance. These bores
161
are placed so as to angle forward in such a way as to create an appropriate axial component on the burner axis
60
. In active connection with these bores
161
, additional fuel injectors
170
which add a certain quantity of a preferably gaseous fuel into the respective air quantity
160
have been provided so that a uniform fuel concentration
150
appears over the flow cross-section in the mixing pipe
20
, as is symbolized in the figure. Exactly this uniform fuel concentration
150
, in particular the strong concentration on the burner axis
60
, ensures that a stabilization of the flame front occurs at the outlet of the burner, especially when using a central injection with liquid fuel, so that any occurrence of combustor pulsations are avoided.
In order to better comprehend the construction of the rotation generator
100
, it is advantageous to explain
FIG. 6
at least in conjunction with FIG.
7
. If needed, the following text therefore will refer to the other figures when describing FIG.
6
.
The first part of the burner according to
FIG. 4
is formed by the rotation generator
100
in FIG.
6
. The latter consists of two hollow, conical partial bodies
101
,
102
which are stacked offset inside each other. The number of conical partial bodies natural may be greater than two, as can be seen in
FIGS. 5 and 6
. As will also be explained further below, this depends in each case on the operating mode of the burner overall. In certain operating configurations it is possible that a rotation generator consisting of a single spiral is provided. The offset of the respective center axis or longitudinal symmetry axes
101
b
,
102
b
(see
FIG. 7
) of the conical partial bodies
101
,
102
relative to each other creates in each case in the adjoining wall, in a mirror-symmetrical arrangement, a tangential channel, i.e., an air inlet slit
119
,
120
(see
FIG. 7
) through which the combustion air
115
flows into the interior of the rotation generator
100
, i.e., into the conical cavity
114
of the same. The conical shape of the shown partial bodies
101
,
102
in the flow direction has a specific fixed angle. Naturally, depending on the specific operating case, the partial bodies
101
,
102
may have an increasing or decreasing conical angle in the flow direction, similar to a diffuser or confusor. The two last mentioned forms are not shown in the drawing since the expert will be able to understand them easily. The two conical partial bodies
101
,
102
each have a cylindrical, annular starting part
101
a
. The fuel nozzle
103
already mentioned in reference to
FIG. 2
which is preferably operated with a liquid fuel
112
is located in the area of this cylindrical starting part. The injection
104
of this fuel
112
coincides approximately with the narrowest cross-section of the conical cavity
114
formed by the conical partial bodies
101
,
102
. The injection capacity and the type of this fuel nozzle
103
depend on the specified parameters of the respective burner. The conical partial bodies
101
,
102
also each have a fuel line
108
,
109
which are located along the tangential air inlet slits
119
,
120
and are provided with injection openings
117
through which preferably a gaseous fuel
113
is injected into the combustion air
115
flowing there, as is indicated symbolically by arrows
116
. These fuel lines
108
,
109
are arranged preferably not after the tangential inflow, prior to the entrance into the conical cavity
114
, in order to obtain an optimum air/fuel mixture. The fuel
112
supplied through the fuel nozzle
103
is, as mentioned, usually a liquid fuel, whereby a mixture can be easily formed with another medium also, for example, with recycled flue gas. This fuel
112
is preferably injected at a very acute angle into the conical cavity
114
. This means that after the fuel nozzle
103
a conical fuel spray forms, which is enclosed and reduced by the tangentially inflowing, rotational combustion air
115
. The concentration of the injected fuel
112
is then constantly reduced in axial direction by the inflowing combustion air
115
, resulting in a mixing that approaches an evaporation. If a gaseous fuel
113
is added via the opening nozzles
117
, the fuel/air mixture is formed directly at the end of the air inlet slits
119
,
120
. If the combustion air
115
is additionally preheated or enriched, for example, with recycled flue gas or exhaust gas, this greatly supports the evaporation of the liquid fuel
112
, before this mixture flows into the next stage, here into the transition piece
200
(see FIGS.
4
and
10
). The same concepts also apply if liquid fuels are supplied via lines
108
,
109
. When designing the conical partial bodies
101
,
102
in regard to the conical angle and the width of the tangential air inlet slits
119
,
120
, narrow limits must actually be kept, so that the desired flow field of the combustion air
115
is able to form at the outlet of the rotation generator
100
. In general, it can be said that a reduction of the tangential air inlet slits
119
,
120
promotes the faster formation of a flowback zone already in the area of the rotation generator. The axial speed within the rotation generator
100
can be increased or stabilized with an addition of an air quantity that is described in more detail in reference to
FIG. 2
(No.
160
). A corresponding rotation generation in active connection with the subsequent transition piece
200
(
FIGS. 4 and 10
) prevents the formation of flow separations within the mixing pipe following the rotation generator
100
. The construction of the rotation generator
100
is also very suitable for changing the size of the tangential air inlet slits
119
,
120
, so that a relatively large operating bandwidth can be covered without changing the design length of the rotation generator
100
. The partial bodies
101
,
102
naturally can also be moved relative to each other on a different plane, whereby even an overlapping of them is possible. It is also possible to stack the partial bodies
101
,
102
spiral-like inside each other by a counter-rotating movement. This makes it possible to change the shape, size, and configuration of the tangential air inlet slits
119
,
120
as desired, so that the rotation generator
100
can be universally used without changing its design length.
FIG. 7
, among other things, shows the geometric configuration of optionally provided baffle plates
121
a
,
121
b
. They have a flow introduction function and extend, depending on their length, the respective end of the conical partial bodies
101
,
102
in the flow direction relative to the combustion air
115
. The channeling of the combustion air
115
into the conical cavity
114
can be optimized by opening or closing the baffle plates
121
a
,
121
b
around a pivoting point
123
placed in the area of the entrance of this channel into the conical cavity
114
; this is, in particular, necessary if the original slit size of the tangential air inlet slits
119
,
120
should be changed dynamically, for example, in order to change the speed of the combustion air
115
. Naturally, these dynamic measures can also be provided statically, in that baffle plates, as required, form a fixed part with the conical partial bodies
101
,
102
.
Compared to
FIG. 4
,
FIG. 8
shows that the rotation generator
100
is now constructed of four partial bodies
130
,
131
,
132
,
133
. The associated longitudinal symmetry axes for each partial body are designated with the letter “a.” Regarding this configuration, it can be said that as a result of the lower rotation intensity generated with it and in connection with a correspondingly greater slit width, it is ideally suited to prevent the bursting of the turbulence flow on the outlet side of the rotation generator in the mixing pipe, so that the mixing pipe is able to optimally fulfill its intended role.
Compared to
FIG. 8
, the difference in
FIG. 9
is that here the partial bodies
140
,
141
,
142
,
143
have a blade profile shape which has been provided to create a certain flow. Other than that, the operating mode of the rotation generator has remained the same. The admixture of the fuel
116
into the combustion air stream
115
is accomplished from the inside of the blade profiles, i.e., the fuel line
108
is now integrated into the individual blades. The longitudinal symmetry axes for the individual partial bodies are also designated with the letter “a” here.
FIG. 10
shows a three-dimensional view of the transition piece
200
. The transition geometry is constructed for a rotation generator
100
with four partial bodies, corresponding to
FIG. 5
or
6
. Accordingly, the transition geometry has four transition channels
201
as a natural extension of the partial bodies acting upstream, so that the conical quarter surface of said partial bodies is extended until it intersects the wall of the mixing pipe. The same concepts also apply if the rotation generator has been constructed according to a different principle than the one described in reference to FIG.
4
. The surface of the individual transition channels
201
that extends downward in the flow direction has a spiral shape in the flow direction that describes a sickle-shaped progression, corresponding to the fact that the flow cross-section of the transition piece
200
is in this case conically extended in the flow direction. The rotation angle of the transition channels
201
in the flow direction has been chosen so that the pipe flow has then a sufficiently long section available before the change in diameter at the combustor inlet to achieve a perfect premixing with the injected fuel. The above mentioned measures furthermore increase the axial direction at the mixing pipe wall downstream from the rotation generator. The transition geometry and the measures in the area of the mixing pipe bring about a clear increase in the axial speed profile towards the center of the mixing pipe, decisively counteracting the risk of a premature ignition.
FIG. 11
shows the already discussed tear-off edge formed at the burner outlet. The flow cross-section of the pipe
20
in this area has the transition radius R whose size depends principally on the flow inside the pipe
20
. This radius R is selected so that the flow closely follows the wall and in this way causes the rotation value to greatly increase. Quantitatively, the size of the radius R can be defined so that it is greater than 10% of the inside diameter d of the pipe
20
. Compared to the flow without a radius, the flowback bubble now increases enormously. This radius R extends up to the outlet plane of the pipe
20
, whereby the angle β between beginning and end of the curvature is less than 90°. The tear-off edge A extends along one leg of the angle β into the interior of the pipe
20
and in this way forms a tear-off stage S relative to the front point of the tear-off edge A whose depth is greater than 3 mm. Naturally, the edge which here extends parallel to the outlet plane of the pipe
20
can now be returned to the stage of the outlet plane with a curved progression. The angle β′ between the tangent of the tear-off edge A and the vertical to the exit plane of the pipe
20
is identical to the angle β. The advantages of this design of the tear-off edge are found in EP-0 780 629 A2 in section “Description of the Invention.” A further design of the tear-off edge for the same purpose can be achieved with torus-like notches on the combustor side. This publication, including its protected scope in regard to the tear-off edge, is an integral part of this specification.
Claims
- 1. A method for operating a burner comprising the steps of:providing a burner for a heat generator comprising a rotation generator for generating a rotational flow of combustion air and including at least one fuel injector, and at least one sensor located in a downstream air flow direction from the at least one fuel injector for detecting a flashback of a premix flame formed in a combustion chamber and initiating a fuel regulation, detecting a flashback of the premix flame by the sensor, at least temporarily reducing a fuel quantity supplying the premix flame when the flashback of the flame is detected, and simultaneously increasing a fuel quantity supplying a pilot burner system of the burner such that a total fuel quantity and an output of the heat generator remain constant.
- 2. The method as claimed in claim 1,wherein the at least one fuel injector injects at least one fuel into the flow of combustion air for formation of a premix flame; and wherein the burner further comprises a mixing section located in the downstream air flow direction from the rotation generator and including a first section and a mixing pipe, the first section including a plurality of transition channels for transferring the flow formed in the rotation generator into the mixing pipe located downstream from the transition channels, the mixing pipe including a pilot burner system in fluid communication with the combustion chamber, and the combustion chamber being located in a downstream flow direction from the mixing pipe.
- 3. The method as claimed in claim 2, wherein the rotation generator further includes at least two hollow, conical partial bodies which are nested inside each other in the downstream air flow direction, wherein the partial bodies have respective longitudinal symmetry axes which extend offset relative to each other such that adjacent walls of the partial bodies form longitudinally extending tangential channels for the flow of combustion air, and in an interior chamber formed by the partial bodies at least one fuel nozzle is arranged.
- 4. The method as claimed in claim 3, wherein additional fuel injectors are provided along the longitudinal extent of the tangential channels.
- 5. The method as claimed in claim 4, wherein the partial bodies have a cross-section with a blade-shaped profile.
- 6. The method as claimed in claim 2, wherein the pilot burner system includes a cooling means and at least one ignition device.
- 7. The method as claimed in claim 2, wherein the pilot burner system includes at least two media-carrying chambers and a subsequent chamber, a media from the at least two media-carrying chambers is capable of being mixed in the subsequent chamber and the subsequent chamber including means for forming a pilot flame in the combustion chamber from the mixture of the two media.
- 8. The method as claimed in claim 7, wherein the at least two media-carrying chambers are constructed in a ring-shape, through a first ring chamber a gaseous fuel flows, and through a second ring chamber an air quantity flows, in the second ring chamber a means is integrated through which the air flowing therethrough brings about an impact cooling on a heat shield located on an end side of the pilot burner system and an ignition device extends through the second ring chamber.
- 9. The method as claimed in claim 8, wherein the impact cooling is performed with a perforated plate forming a bottom of the second ring chamber.
- 10. The method as claimed in claim 2, wherein a burner front portion of the mixing pipe is constructed with a tear-off edge facing the combustion chamber.
- 11. The method as claimed in claim 2, wherein a number of transition channels in the mixing section corresponds to a number of partial flows created by the rotation generator.
- 12. The method as claimed in claim 2, wherein the mixing pipe located downstream of the transition channels is provided in the air flow direction and a peripheral direction with openings for injecting an air stream into the interior of the mixing pipe.
- 13. The method as claimed in claim 2, wherein between the mixing section and the combustion chamber there is a change in cross-section between the cross-section of the mixing section and the cross-section of the combustion space, the change in cross-section induces the initial flow cross-section of the combustion chamber and a premix flame with a flowback zone is formed in an area of the change in cross-section.
Priority Claims (1)
Number |
Date |
Country |
Kind |
98810922 |
Sep 1998 |
EP |
|
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