EP0987493B1 - Burner for a heat generator - Google Patents

Description

Technical field

The present invention relates to a burner for a heat generator according to Claim 1. It also relates to a method of operation of such a burner.

State of the art

Traditionally, gas turbine burners are used in premix mode hazards. Such premix burners are from EP-B1-0 321 809 and from DE-195 47 913.0 became known. Thanks to the upstream fuel injection such premix burners, the fuel is premixed with the air before the Combustion takes place. This will make it ignitable within the burner Mixture provided for further combustion. In general, find that such new generation burners have several advantages offer a stable flame position, lower pollutant emissions (Co, UHC, NOx), minimization of pulsations, complete burnout, coverage a larger operating area, a good cross ignition between the different burners, especially with stepped load position, in which the burners are operated interdependent, an adjustment the flame to the corresponding combustion chamber geometry, a compact Construction, an improved mixture of flow media, an improved one "Pattern factor" of the temperature distribution in the combustion chamber, i.e. a balanced one Temperature profile of the combustion chamber flow.

If, however, unforeseeable faults occur during operation, the flame may become unstable. If the one that has jumped back can then stabilize within the burner, it burns as a diffusion flame at a very high temperature, approx. 1900 ° C. Within a short time in the range of 10 to max. 30 seconds, the burner overheats and is destroyed. The subsequent turbine blades may then be damaged; in any case, the gas turbine has to be stopped, inspected and repaired, which leads to immense costs.
It has been shown that there is a high risk in this regard, in particular in the case of prototype gas turbines with new combustion technology or the combustion of fuels containing hydrogen (MBtu or LBtu gases).

EP-A-0 816 760 describes a burner for operating a gas turbine with several in the premixing section downstream of the fuel injection Glass fiber are arranged, which via optical sensors with the Control system of the gas turbine are connected.

Presentation of the invention

The invention seeks to remedy this. The invention as set out in the claims is characterized, the task is based on one burner and one Propose measures of the type mentioned at the outset, by means of which stabilization of the flame in the burner is maximized.

According to the invention, it is proposed that the burner be fitted at a suitable point compact non-contact flame detector.

The main advantages of the invention are the fact that the burner attached sensor reports a flame back. Then the Reduced the amount of premix fuel and at the same time increased the amount of pilot fuel so that the total amount of fuel and thus the turbine power is constant remains. By which a reduction, i.e. the amount of premix fuel, is able the retracted flame no longer stabilizes in the burner, it is inevitably flushed out of the burner. This allows the destruction prevent the burner.

Such a sensor or flame monitor can be help of high temperature resistant Realize glass fibers. The fibers are arranged in such a way that their control field endangered areas, but not the normal burning pilot and premix flame. The UV component (approx. 300-330 nm) of the radiation detected by the sensor Spectrally analyzed with suitable filters. About the ratio of intensity Different wavelengths can be flashback in the burner within milliseconds be recognized. If the combustion chamber consists of a number of burners, suitable data acquisition can be used to determine which one Burner of flashback has occurred and suitable ones can be used Measures to remedy the causes are taken.

Advantageous and expedient developments of the task solution according to the invention are characterized in the further claims.

Exemplary embodiments of the invention are described below with reference to the drawings explained in more detail. All of which are insignificant for the immediate understanding of the invention Features have been left out. The same elements are in the different Figures with the same reference numerals. The flow direction the media is indicated by arrows.

Brief description of the drawings

Fig. 1

eine schematische Ansicht eines Brenners, mit eingebautem Sensor,

Fig. 2

einen Brenner mit stattgefundenem Flashback und mit nachfolgender Stabilisierung der Flamme im Brenner,

Fig. 3

einen schematischen Ablauf der Brennstoff-Steuerung über die Zeit bei einem Flammenrückschlag,

Fig. 4

einen integralen Schnitt durch einen als Vormischbrenner ausgelegten Brenner mit einer Mischstrecke stromab eines Drallerzeugers sowie mit Pilotbrennern,

Fig. 5

eine schematische Darstellung des Brenners gemäss Fig. 1 mit Disposition der zusätzlichen Brennstoff-Injektoren,

Fig. 6

einen aus mehreren Schalen bestehenden Drallerzeuger in perspektivischer Darstellung, entsprechend aufgeschnitten,

Fig. 7

einen Querschnitt durch einen zweischaligen Drallerzeuger,

Fig. 8

einen Querschnitt durch einen vierschaligen Drallerzeuger,

Fig. 9

eine Ansicht durch einen Drallerzeuger, dessen Schalen schaufelförmig profiliert sind,

Fig. 10

eine Ausgestaltung der Uebergangsgeometrie zwischen Drallerzeuger und Mischstrecke und

Fig. 11

eine Abrisskante zur räumlichen Stabilisierung der Rückströmzone.

It shows:

Fig. 1

1 shows a schematic view of a burner with a built-in sensor,

Fig. 2

a burner with flashback and subsequent flame stabilization in the burner,

Fig. 3

a schematic sequence of fuel control over time in the event of a flashback,

Fig. 4

an integral section through a burner designed as a premix burner with a mixing section downstream of a swirl generator and with pilot burners,

Fig. 5

2 shows a schematic representation of the burner according to FIG. 1 with disposition of the additional fuel injectors,

Fig. 6

a swirl generator consisting of several shells in a perspective view, cut open accordingly,

Fig. 7

a cross section through a double-shell swirl generator,

Fig. 8

a cross section through a four-shell swirl generator,

Fig. 9

2 shows a view through a swirl generator, the shells of which are profiled in a shovel shape,

Fig. 10

an embodiment of the transition geometry between swirl generator and mixing section and

Fig. 11

a tear-off edge for spatial stabilization of the backflow zone.

WAYS OF IMPLEMENTING THE INVENTION, INDUSTRIAL APPLICABILITY

Fig. 1 shows a schematic overview of a premix burner, the Formation of such a burner is described in detail in FIGS. 4-11. This premix burner basically consists of a swirl generator 100 a mixing section 220 connected downstream of this swirl generator, in which the Mixing section 220 downstream combustion chamber 30 a system of pilot burners 300 acts with corresponding pilot flames 70. This fulfills Fig. 1 in connection with FIG. 2 only the task of showing how the striking back 81 of the premix flame, which is represented here by the backflow bladder 50, by sensors 400 is recorded, and immediate remedial measures are initiated. there is always observed to reignite from the combustion chamber 30 comes to the fuel injectors 116. Stabilizing this reignited Flame 80 in the area of fuel injectors 116 is then no longer closed bypass, whereby a diffusion flame with very high temperatures of approx. 1900 ° C. This flame inevitably leads within a few seconds to destroy the burner. At least one sensor 400 becomes immediate placed downstream of the fuel injectors 116 and should not be the premix flame 50 still the pilot flames 70, but only the areas at risk to capture. Such a sensor 400 preferably consists of high-temperature resistant ones Glass fibers, which are arranged so that their viewing angle 402 just that only the areas at risk are recorded. The radiation detected by the sensor is forwarded 401 and spectrally analyzed with suitable filters. About the relationship The intensities at different wavelengths can cause a flashback can be recognized in the burner within milliseconds. By a suitable one Data acquisition can be determined for which burner in the network the flashback has taken place, taking suitable measures can be taken to remedy the cause.

Fig. 3 shows which measures are initiated after a flashback become. On notification that the flame is struck back 81 a control 82 directly accesses the fuel quantity for the premix flame 50, which is immediately reduced according to certain criteria. simultaneously engages a second control 83, which determines the amount of fuel for the pilot burner system 300, i.e. for the pilot flame 70, increased. Aim this opposite The fuel supply is to keep the turbine output constant. Through the Reduction of the amount of fuel for the premix flame 50 can be the struck back Do not stabilize the flame in the burner anymore, it will become from the burner washed out, which safely prevents the inevitable destruction of the burner becomes. 3 shows the qualitative sequence of the fuel control over time, the flushing out at the extreme points of this control 84 of the retarded flame takes place.

This procedure for the immediate determination of a flashback does not apply to all premix burners based on swirl flow, independently how the burner is geometrically constructed, and regardless of which one Way the swirl flow is generated. In particular, this can be Apply the method to the premix burner according to EP-B1-0 321 809, whereby this document is an integral part of the present description forms.

Fig. 4 shows the overall structure of a burner that can be operated by swirl flow. Initially, a swirl generator 100 is effective, the design of which follows in the following Fig. 5-8 is shown and described in more detail. It is about this swirl generator 100 around a cone-shaped structure, the multiple of one tangentially flowing combustion air flow 115 is applied. The The flow that forms here is based on a flow downstream of the swirl generator 100 provided transition geometry seamlessly transferred into a transition piece 200, in such a way that no separation areas can occur there. The configuration this transition geometry is described in more detail in FIG. 10. This Transition piece 200 is through on the outflow side of the transition geometry a mixing tube 20 extends, both parts of the actual mixing section 220 form. Of course, the mixing section 220 can be made from a single piece exist, i.e. then that the transition piece 200 and the mixing tube 20 into one single contiguous entities merge, the characteristics of each part are preserved. Are transition piece 200 and Mixing tube 20 created from two parts, these are through a sleeve ring 10 connected, the same socket ring 10 on the head side as anchoring surface serves for the swirl generator 100. Such a sleeve ring 10 also has the advantage that different mixing tubes can be used. outflow side of the mixing tube 20 is the actual combustion chamber 30 one Combustion chamber, which is only symbolized here by a flame tube. The Mixing section 220 largely fulfills the task that is downstream of the swirl generator 100 a defined route is provided, in which a perfect premix of different types of fuel can be achieved. This mixing section, so primarily the mixing tube 20, also allows lossless Flow guidance, so that it is also in operative connection with the transition geometry initially do not form a backflow zone or backflow bubble can, thus over the length of the mixing section 220 to the mixing quality for all Fuel types influence can be exerted. However, this mixing section 220 has yet another property, which is that in it the axial velocity profile has a pronounced maximum on the axis, so that reignition of the flame from the combustion chamber itself is prevented should. However, it is correct that with such a configuration this Axial velocity drops towards the wall. To reignite in this area too To prevent as much as possible, the mixing tube 20 in the flow and circumferential direction with a number of regularly or irregularly distributed holes Provide 21 different cross sections and directions, through which one Air flow into the interior of the mixing tube 20, and along the wall in the In the sense of filming, induce an increase in the flow rate. These holes 21 can also be designed so that on the inner wall of the mixing tube 20 at least additionally an effusion cooling established. Another possibility is to increase the speed of the mixture To achieve within the mixing tube 20 is that Flow cross section downstream of the transition channels 201, which the already mentioned transition geometry form, undergoes a narrowing, whereby the entire speed level within the mixing tube 20 is raised becomes. In the figure, these bores 21 run at an acute angle the burner axis 60. Furthermore, the outlet corresponds to the transition channels 201 the narrowest flow cross section of the mixing tube 20. Die named transition channels 201 accordingly bridge the respective cross-sectional difference, without negatively influencing the flow formed.

If the chosen arrangement in guiding the pipe flow 40 along the Mixing tube 20 triggers an intolerable pressure loss, can counter this Remedy can be created by placing a in the figure at the end of this mixing tube Diffuser not shown is provided. At the end of the mixing tube 20 closes Then there is a combustion chamber 30 (combustion chamber), between the two Flow cross sections a cross-sectional jump formed by a burner front 70 is available. Only here does a central flame front form with a Backflow zone 50, which has the properties of a flame front disembodied flame holder. Forms within this cross-sectional jump during operation a flow-like edge zone, in which the negative pressure prevailing there creates vortical detachments, so leads this leads to an increased ring stabilization of the backflow zone 50 It should be noted that the creation of a stable backflow zone 50 also requires a sufficiently high number of twists in a tube. Is such a thing first undesirable, stable backflow zones can be smaller by the supply strongly swirled air flows at the pipe end, for example due to tangential Openings. It is assumed here that the required one Air volume is approximately 5-20% of the total air volume. As for the design the burner front 70 at the end of the mixing tube 20 to stabilize the Backflow zone or backflow bladder 50 is referred to in the description below Fig. 8 referenced. To intervene in the event of a flashback, reference is made to the explanations under Fig. 1-3.

A pilot burner system becomes concentric with the mixing tube 20, in the area of its outlet 300 provided. This consists of an inner annular chamber 301, in which flows in a fuel, preferably a gaseous fuel 303. In addition to this inner annular chamber 301 is a second annular chamber Dispatched 302, into which an amount of air 304 flows. Both annular chambers 301. 302 have individually designed through openings, such that the individual media 303, 304 functionally in a common downstream Flow ring chamber 308. Transfer of gaseous fuel 303 from the annular chamber 301 into the downstream annular chamber 308 by a Number of openings 309 arranged in the circumferential direction. The Through geometry of these openings 309 is designed so that the gaseous Fuel 303 with a large mixing potential in the downstream Annular chamber 308 flows. The other annular chamber 302 closes with one perforated plate 305, the holes 310 provided here designed so are that the amount of air 304 flowing through there is an impact cooling on the base plate 307 of the downstream ring chamber 308. This base plate has the Function of a heat protection plate against the caloric load from the Combustion chamber 30, so that this impingement cooling must be extremely efficient here. After cooling, this air mixes within this annular chamber 308 with the inflowing gaseous fuel 303 from the openings 309 of the upstream annular chamber 301 before this mixture through a number of bores 306 arranged on the combustion chamber side into the combustion chamber 30 flows out. The mixture flowing out burns as a premixed diffusion flame with minimized pollutant emissions and therefore forms Bore 306 a pilot burner acting in the combustion chamber 30, which one guaranteed stable operation.

An ignition device becomes through the air-circulating ring chamber 302 311 passed through, which in the downstream annular chamber 308 Ignition of the mixture formed there. For one thing, it takes for this passage of the ignition device 311 no further constructive Measures, and on the other hand, this ignition device 311 is constantly by the air 304 flowing there is cooled anyway. This is very important because when using it temperature of approx. 1000 ° C can be reached with a glow plug. However, since there is only a low voltage for the operation proposed here, high current is required, the susceptibility of the ignition device is therefore eliminated against condensation water. Due to the arrangement of the glow plug, the use of a spark plug is also possible within of the burner, the respective ignition device 311 is thermally slightly loaded, which means that no additional cooling is required and leakages are also eliminated avoided.

FIG. 5 shows a schematic view of the burner according to FIG. 4, here in particular the flushing of a centrally arranged fuel nozzle 103 (See FIG. 6) and the effect of fuel injectors 170 is pointed out. The mode of operation of the remaining main components of the burner, namely swirl generator 100 and transition piece 200 are among the following figures described in more detail. The fuel nozzle 103 is spaced apart Ring 190 encased, in which a number arranged in the circumferential direction Bores 161 are placed through which an amount of air 160 in an annular Chamber 180 flows and rinses the fuel lance there. This Bores 161 are tapered forward so as to be adequate axial component arises on the burner axis 60. In active connection with these fuel holes 161 are provided with additional fuel injectors 170, which contains a certain amount of preferably a gaseous fuel enter the respective amount of air 160 in such a way that a sets uniform fuel concentration 150 over the flow cross-section, as the representation in the figure symbolizes. Exactly this even Fuel concentration 150, especially the strong concentration the burner axis 60 ensures that the flame front is stabilized at the burner outlet, especially when using a central one Injection with liquid fuel, resulting in combustion chamber pulsations be avoided.

In order to better understand the structure of the swirl generator 100, it is advantageous to if at least FIG. 7 is used simultaneously with FIG. 6. Hereinafter 6 is referred to the other figures as required in the description of FIG. 6.

The first part of the burner according to FIG. 4 forms the swirl generator shown in FIG. 6 100. This consists of two hollow conical partial bodies 101, 102, which are nested in a staggered manner. The number of conical Partial body can of course be larger than two, like the figures 5 and 6 show; this depends in each case, as will be explained in more detail below will depend on the operating mode of the entire burner. It is with certain Operating constellations are not excluded, one from a single spiral to provide existing swirl generator. The offset of the respective central axis or longitudinal symmetry axes 101b, 102b (see FIG. 7) of the conical partial bodies 101, 102 creates each other in the adjacent wall, in mirror image Arrangement, each a tangential channel, i.e. an air inlet slot 119, 120 (see FIG. 7), through which the combustion air 115 in the interior of the swirl generator 100, i.e. flows into the cone cavity 114 of the same. The cone shape the partial body 101, 102 shown in the flow direction has a certain one fixed angle. Of course, depending on the operational use, the partial bodies can 101, 102 an increasing or decreasing cone inclination in the flow direction have, similar to a diffuser or confuser. The latter two Shapes are not recorded in the drawing, as they are without for the specialist are further sensitive. The two conical partial bodies 101, 102 have each have a cylindrical annular starting part 101a. In the area of this cylindrical Initially, the fuel nozzle 103 already mentioned under FIG. 2 is housed, which is preferably operated with a liquid fuel 112 becomes. The injection 104 of this fuel 112 coincides with the narrowest Cross-section of the conical cavity formed by the conical partial bodies 101, 102 114 together. The injection capacity and the type of this fuel nozzle 103 depends on the specified parameters of the respective burner. The conical sub-bodies 101, 102 each have a fuel line 108, 109, which along the tangential air inlet slots 119, 120 are arranged and provided with injection openings 117 through which preferably a gaseous fuel 113 in the combustion air flowing through there 115 is injected, as the arrows 116 want to symbolize. These fuel lines 108, 109 are preferably at the end of the latest tangential inflow, before entering the cone cavity 114, arranged this to get an optimal air / fuel mixture. The one through the fuel nozzle 103 introduced fuel 112 is, as mentioned, in Normally around a liquid fuel, where a mixture formation with a other medium, for example with a recirculated flue gas, without further ado is possible. This fuel 112 is preferably very pointed under one Angle injected into the cone cavity 114. Forms from the fuel nozzle 103 there is thus a conical fuel spray 105 which flows in from the tangential rotating combustion air 115 is enclosed and degraded. In The concentration of the injected fuel 112 then becomes axial continuously through the incoming combustion air 115 for mixing Degraded towards evaporation. If a gaseous fuel 113 over the Introduced opening nozzles 117, the fuel / air mixture is formed directly at the end of the air inlet slots 119, 120. Is the combustion air 115 additionally preheated, or for example with a recirculated Flue gas or exhaust gas enriched, this supports the evaporation sustainably of liquid fuel 112 before this mixture is downstream Stage flows, here in the transition piece 200 (see FIGS. 4 and 10). The same Considerations also apply when liquid lines 108, 109 Fuels should be supplied. When designing the tapered partial body 101, 102 with regard to the cone angle and the width of the tangential air inlet slots 119, 120 are strict limits to be observed so that the desired Flow field of the combustion air 115 at the exit of the swirl generator 100 can set. Generally speaking, a downsizing of the tangential air inlet slots 119, 120 the faster formation of a backflow zone already favored in the area of the swirl generator. The axial speed Within the swirl generator 100, a corresponding one shown in FIG (Item 160) Increase or stabilize the supply of an air quantity described in more detail. A corresponding swirl generation in operative connection with the downstream one Transition piece 200 (see FIGS. 4 and 10) prevents the formation of Flow separations within the swirl generator 100 downstream Mixing tube. The construction of the swirl generator 100 is furthermore particularly suitable, change the size of the tangential air inlet slots 119, 120, which is a relatively large one without changing the overall length of the swirl generator 100 operational bandwidth can be captured. Of course, the partial bodies 101, 102 can also be moved relative to one another in another plane, which even an overlap of the same can be provided. It is further possible, the sub-bodies 101, 102 by a counter-rotating movement spiral to nest into each other. So it is possible, the shape, the size and to vary the configuration of the tangential air inlet slots 119, 120 as desired, which makes the swirl generator 100 universal without changing its overall length can be used.

7 shows, among other things, the geometrical configuration of optional ones Baffles 121a, 121b. They have a flow initiation function which, according to their length, the respective end of the tapered Partial bodies 101, 102 in the flow direction with respect to the combustion air 115 extend. Channeling the combustion air 115 into the cone cavity 114 can be opened or closed by one of the baffles 121a, 121b Area of entry of this channel into the cone cavity 114 placed fulcrum 123 can be optimized, especially if the original Gap size of the tangential air inlet slots 119, 120 changed dynamically should be, for example, to change the speed of the combustion air 115 to achieve. Of course, these can be dynamic Precautions can also be provided statically by using baffles as needed form a fixed component with the tapered partial bodies 101, 102.

8 shows, compared to FIG. 4, that the swirl generator 100 now consists of four partial bodies 130, 131, 132, 133 is constructed. The associated longitudinal symmetry axes for each sub-body are marked with the letter a. To this Configuration is to be said that it is due to the lower generated with it Twist strength and in cooperation with a correspondingly enlarged Slot width is best suited, the bursting of the vortex flow on the downstream side to prevent the swirl generator in the mixing tube, thus causing the mixing tube to can fulfill the intended role.

FIG. 9 differs from FIG. 8 in that the partial body 140, 141, 142, 143 have a blade profile shape which is used to provide a certain Flow is provided. Otherwise, the mode of operation of the swirl generator stayed the same. The admixture of fuel 116 in the combustion air flow 115 happens from inside the blade profiles, i.e. the fuel line 108 is now integrated in the individual blades. Here, too, are the longitudinal axes of symmetry to the individual partial bodies with the Letter a marked.

10 shows the transition piece 200 in a three-dimensional view. The transition geometry is corresponding for a swirl generator 100 with four partial bodies 5 or 6, built. Accordingly, the transition geometry as a natural extension of the upstream partial bodies, four transition channels 201 on, whereby the conical quarter area of said partial body is extended until it cuts the wall of the mixing tube. The same considerations also apply if the swirl generator is based on a principle other than the one below Fig. 4 is constructed. The down in the flow direction running surface of the individual transition channels 201 has a flow direction spiral shape, which has a crescent shape Course describes, corresponding to the fact that the flow cross-section is present of the transition piece 200 flared in the flow direction. The swirl angle of the transition channels 201 in the flow direction is so chosen that the pipe flow then up to the cross-sectional jump on Combustion chamber entry still has a sufficient distance to be perfect Premix with the injected fuel. Furthermore increased the axial speed due to the above-mentioned measures on the mixing tube wall downstream of the swirl generator. The transition geometry and the measures in the area of the mixing tube cause a significant increase the axial velocity profile towards the center of the mixing tube, see above that the danger of early ignition is decisively counteracted.

11 shows the tear-off edge already mentioned which emerges at the burner is formed. The flow cross section of the tube 20 receives one in this area Transition radius R, the size of which basically depends on the flow within of the tube 20 depends. This radius R is chosen so that the Applies flow to the wall and so the swirl number increases sharply. Quantitatively the size of the radius R can be defined so that it is> 10% of the inside diameter d of the tube is 20. Opposite a flow without a radius Now the backflow bladder 50 increases enormously. This radius R runs to the exit plane of the tube 20, the angle β between the beginning and end of curvature is <90 °. Along one leg of the angle β the tear-off edge A runs inside the tube 20 and thus forms a tear-off step S opposite the front point of the tear-off edge A, whose depth> 3 mm is. Of course, this can be parallel to the exit plane of the tube 20 running edge based on a curved course back to the exit level to be brought. The angle β ', which is between the tangent of the tear-off edge A and perpendicular to the exit plane of the tube 20 is the same as large as angle β. The advantages of this formation of this tear-off edge go out EP-0 780 629 A2 under the chapter "Presentation of the invention". Another Design of the tear-off edge for the same purpose can be done with the combustion chamber achieve toroidal notches. This publication is inclusive the scope of protection there regarding the tear-off edge is an integrating one Part of this description.

LIST OF REFERENCE NUMBERS

10

jack ring

20

Mixing tube, part of the mixing section 220

21

Holes, openings

30

Combustion chamber, combustion chamber

40

Flow, pipe flow in the mixing pipe, main flow

50

Backflow zone, backflow bubble, premix flame

60

Brenner

70

pilot flame

80

Flame in the burner

81

flashback

82

Regulation fuel for the premix flame

83

Control fuel for the pilot flame

84

Flushing out the flame from the burner

100

swirl generator

101, 102

Partial conical body

101

Annular initial part

101b, 102b

Longitudinal axes of symmetry

103

fuel nozzle

104

fuel injection

105

Fuel spray (fuel injection profile)

108, 109

fuel lines

112

Liquid fuel

113

Gaseous fuel

114

conical cavity

115

Combustion air (combustion air flow)

116

Fuel injection from lines 108, 109

117

Fuel nozzles, fuel injectors

119, 120

Tangential air inlet slots

121a, 121b

baffles

123

Pivot point of the guide plates

130, 131, 132, 133

partial body

131a, 131a, 132a, 133a

Longitudinal axes of symmetry

140, 141, 142, 143

Vane-shaped partial body

140a, 141a, 142a, 143a

Longitudinal axes of symmetry

150

fuel concentration

160

Air volume, mixed air

161

Holes, openings

170

Fuel injectors

180

Annular air chamber

190

ring

200

Transition piece, part of the mixing section 220

201

Transition passages

220

mixing section

300

Pilot burner system

301

Inner ring chamber

302

Secondary ring chamber

303

Gaseous fuel

304

air flow

305

Perforated plate

306

Drilling in the combustion chamber, pilot burner

307

Heat Shield

308

Downstream ring chamber

309

Openings of the inner ring chamber

310

Holes for impingement cooling of the heat protection plate

311

detonator

400

sensor

401

Forwarding of sensory detection

402

Viewing angle of the sensor

Claims (15)

1. Burner for operating a heat generator, the burner consisting, upstream of the combustion space (30), of at least one premixing zone (220), which premixing zone has means (100) for generating a swirl flow of combustion air and which premixing zone is equipped with at least one fuel injector (103, 117), there being arranged, downstream of the fuel injector, at least one sensor (400) which detects a flashback of the premix flame out of the combustion space into the interior of the burner and triggers fuel regulation.
2. Burner according to Claim 1, characterized in that the burner consists essentially of a swirl generator for a combustion-airstream, and of means for injecting at least one fuel into the combustion-airstream to form a premix flame, there being arranged, downstream of the swirl generator, a mixing zone which, within a first zone part, has in the direction of flow a number of transitional ducts for the transfer of a flow formed in the swirl generator into a mixing tube which follows these transitional ducts downstream, and in that a pilot-burner system (300) is arranged in the lower region of the mixing tube (20) with action into the combustion space (30) following the mixing tube (20).
3. Burner according to Claim 2, characterized in that the swirl generator (100) consists of at least two hollow conical part-bodies (101, 102; 130, 131, 132, 133; 140, 141, 142, 143) nested one in the other in the direction of flow, in that the respective longitudinal axes of symmetry (101b, 102b; 130a, 131a, 132a, 133a; 140a, 141a, 142a, 143a) of these part-bodies run with an offset relative to one another, in such a way that the adjacent walls of the part-bodies form, in their longitudinal extent, tangential ducts (119, 120) for a combustion-airstream (115), and in that at least one fuel nozzle (103) is capable of acting in the inner space (114) formed by the part-bodies.
4. Burner according to Claim 2, characterized in that the pilot-burner system (300) is cooled and is capable of being operated by means of at least one ignition device (311).
5. Burner according to Claim 2, characterized in that the pilot-burner system (300) consists of at least two media-carrying chambers (301, 302) and of a further common following chamber (308), in that the media (303, 304) from the other two chambers (301, 302) are miscible in this following chamber (308), and in that the following chamber (308) has means for the formation of pilot burners (306) acting into the combustion space (30) and capable of being operated by the mixture of the two media (303, 304).
6. Burner according to Claims 2 and 5, characterized in that the media-carrying chambers (301, 303) are designed annularly and next to one another, in that a gaseous fuel (303) flows through the first annular chamber (301) and an air quantity (304) flows through the second annular chamber (302), in that, in the second annular chamber (302), means (305) are installed, by which the air (304) flowing there implements impact cooling onto a heat shield (307) arranged on the end face of the pilot-burner system (300), and in that the ignition device (311) is led up through the second annular chamber (302).
7. Burner according to Claim 6, characterized in that the means for forming the impact cooling is a perforated plate (305) forming the bottom in the next annular chamber (302).
8. Burner according to Claim 2, characterized in that the burner front of the mixing tube (20) is designed with a breakaway edge (A) with respect to the following combustion space (30).
9. Burner according to Claim 2, characterized in that the number of transitional ducts (201) in the mixing zone (220) corresponds to the number of part-streams formed by the swirl generator (100).
10. Burner according to Claim 2, characterized in that the mixing tube (20) following the transitional ducts (201) is provided, in the direction of flow and in the circumferential direction, with orifices (21) for injecting an airstream into the interior of the mixing tube (20).
11. Burner according to Claim 2, characterized in that a combustion chamber (30) is arranged downstream of the mixing zone (220), in that between the mixing zone (220) and the combustion chamber (30) there is a cross-sectional jump which induces the initial flow cross section of the combustion chamber (30), and in that a premix flame with a back flow zone (50) is formed in the region of this cross-sectional jump.
12. Burner according to Claim 1, characterized in that the premixing zone consists, upstream of the combustion space (30), of a swirl generator (100), which swirl generator consists of at least two hollow conical part-bodies (101, 102; 130, 131, 132, 133; 140, 141, 142, 143) nested one in the other in the direction of flow, in that the respective longitudinal axes of symmetry (101b, 102b; 130a, 131a, 132a, 133a; 140a, 141a, 142a, 143a) of these part-bodies run with an offset to one another, in such a way that the adjacent walls of the part-bodies form, in their longitudinal extent, tangential ducts (119, 120) for a combustion-airstream (115), and in that at least one fuel nozzle (103) is capable of acting in the inner space (114) formed by the part-bodies.
13. Burner according to Claim 2 or 12, characterized in that further fuel injectors (117) are arranged in the region of the tangential ducts (119, 120) in the longitudinal extent of the latter.
14. Burner according to Claim 15, characterized in that the part-bodies (140, 141, 142, 143) have, in cross section, a blade-shaped profiling.
15. Method for operating a burner according to Claims 1 or 2 or 1 and 12, characterized in that a flashback of the flame is detected by the sensor (400) mounted in the burner, and in that, thereupon, the fuel quantity of this flame is reduced at least temporarily and the pilot-fuel quantity simultaneously increased, in such a way that the total fuel quantity and therefore the turbine power output are kept constant.

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