EP1292795B1 - Method for operating a burner with staged premix gas injection - Google Patents

Abstract

The invention relates to a method for operating a burner comprising at least one first fuel supply (5) with a first group of fuel outlets (6) for a first amount of premix fuel, said first group of fuel outlets being essentially arranged in the direction of a burner axis (3); and at least one second fuel supply (7) with a second group of fuel outlets for a second amount of premix fuel, said second group of fuel outlets (8) being essentially arranged in the direction of the burner axis (3). Fuel can be fed to the second fuel supply or supplies (7) independently from the first fuel supply (5). Both fuel supplies (5, 7) are operated using the same fuel. The inventive method for operating a burner enables optimum mixing conditions to be adjusted even in cases of varying loads, quality of gas or gas pre-heating temperatures.

Description

Technical application

The present invention relates to a method for operating a burner, the at least one first Fuel supply with a first group of im Essentially arranged in the direction of the burner axis Fuel outlet openings for the introduction of a first premix fuel in a swirl chamber and one or more second fuel feeds with a second group of essentially in the direction the burner axis arranged fuel outlet openings wherein the second fuel feeds independent of the first fuel supply can be acted upon with fuel.

State of the art

From EP 0 321 809 a conical burner consisting of several shells, a so-called double-cone burner, according to the preamble of claim 1 is known. By means of the conical swirl generator composed of several shells, a swirl flow is generated in the conical interior enclosed by the partial cone shells. Due to a jump in cross section at a combustion chamber end of the burner, the swirl flow becomes unstable, and turns into an annular swirling flow with backflow in the core. This backflow allows the stabilization of a flame front at the burner outlet. The shells of the swirl generator are assembled in such a way that tangential air inlet slots for combustion air are formed along the burner axis. Feed lines for a gaseous premix fuel, which have outlet openings for the premix gas distributed in the direction of the burner axis, are provided on the inflow edge of the conical shells formed in this way. The gas is injected through the outlet openings or bores transversely to the air inlet gap. This injection, in conjunction with the swirl generated in the swirl space of the combustion air-fuel gas flow to a good mixing of the fuel or premixed gas with the combustion air. Good mixing in such premix burners is the prerequisite for low NO _x values during the combustion process.

To further improve such a burner is from EP 0 780 629 a burner for a Heat generator known after the swirl generator an additional mixing section to the other Mixing of fuel and combustion air having. This mixing section can, for example, as Downstream pipe be executed, in which the the swirl generator exiting flow without significant Flow losses is transferred. Through this additional mixing distance can be the degree of mixing further increased and thus the pollutant emissions be reduced.

WO 93/17279 shows another known premix burner in which a cylindrical swirl generator with an additional conical inner body is used. In this burner, the premix gas is also injected via feeders with corresponding outlet openings in the swirl space, which are arranged along the axially extending air inlet slots. This burner has in the conical inner body in addition to a central supply of fuel gas, which can be injected near the outlet opening of the burner for piloting into the swirl space. This additional pilot stage is used to start the burner. However, the supply of the pilot gas in the outlet region of the burner leads to increased NO _x emissions, since in this area only an insufficient mixing with the combustion air can take place.

EP 0918191 A1 shows a generic Burner for operating a heat generator that is parallel to a first feeder for fuel also one second feeder for another type of fuel that matched to the other fuel type is. Both feeds are independent. controllable. By this configuration, the burner without modification with different fuel types operate.

In all the illustrated burners, the premixing gas is injected into the air inlet gap by means of feeds with outlet openings arranged essentially in the direction of the burner axis. Thus, the characteristic of the injection with regard to penetration depth and mixing of the gas jets and the fuel distribution along the air inlet slots or the burner axis are predetermined. The arrangement of the outlet openings thus already determines the mixing quality of the gas and the combustion air and the fuel distribution at the burner outlet. These variables are in turn crucial for NO _x emissions, extinguishing and flashback limits, and burner stability with regard to combustion pulsations.

For different loads, gas qualities or Gas preheating temperatures, however, are different Gasprordrücke on the outlet openings, the again to different premix conditions and Mixing qualities at the fuel outlet lead. From the different premix conditions then result different emission levels and stability conditions, that of the load, the gas quality and the Gas preheating are dependent. The famous burner can therefore only be used for very specific value ranges operate this parameter optimally.

Problematic in the operation of premix burners especially in gas turbines is the partial load range because here the combustion air only comparatively small amounts of fuel be mixed. At the full Mixing the fuel with all the air though A mixture is formed, which is just in the lower one Part load range is no longer flammable, or only to be able to form a very unstable flame. This can lead to harmful combustion pulsations or lead to complete extinction of the flame.

For an adaptation of the known burner to certain Emission levels or on a specific stability window at different loads, ambient conditions, Gas qualities and preheating temperatures On the one hand, there is currently the possibility of using it of multi-burner arrangements, the premix or Premix gas supply to individual burner groups to rate. However, this is only with multi-row burner arrangements possible. For single row annillar combustors this one has Technology has the disadvantage of being a circumferential non-uniform temperature profile in the combustion chamber outlet established.

Another option is Brenner, as above briefly touched, with a so-called pilot fuel supply equip. The burners will be then at very high air ratios as a diffusion burner operated. This results in a superior one hand Flame stability, but on the other hand in high Emission values and other operational Disadvantages.

From EP 433 790 is a double-cone burner or a method for operating a Double cone burner has become known in which over along the tangential Air inlet openings arranged a first fuel, for example natural gas, in the combustion air stream is injected while upstream of the entry of air into the Burner in the area of the entrance slits channels with injectors are formed over the one second, different from the first fuel fuel, such as a mittelkalorisches Gas, which usually contains flammable hydrogen, is injected.

The object of the present invention is to provide a method for operating a burner, with which the burner can be operated stably even when the load, the gas quality or the gas preheating temperature with approximately constant NO _x emission values in Vormischbetrieb possible.

Presentation of the invention

The object is achieved by the method according to the patent claims 1 and 7 solved. Advantageous embodiments and Further developments as well as the procedure are the subject of the dependent claims.

In the present method, a burner with swirl body and swirl space is used which has at least one first fuel feed with a first group of fuel exit openings arranged substantially in the direction of a burner axis for introducing a first premix fuel quantity into the swirl space and one or more second fuel feeds with a second one Group of substantially arranged in the direction of the burner axis fuel outlet openings, wherein the second fuel supply is acted upon regardless of the first fuel supply with fuel / are. For operation of the burner, the supply of the fuel via the first fuel feeds is controlled or regulated separately from the supply of the fuel via the second fuel feeds, wherein the same fuel is supplied to the first and second fuel feeds. By controlling the mass flow ratio of the first quantity of fuel supplied via the first fuel feeds to a second quantity of fuel supplied via the second fuel feeds during operation of the burner, the burner can be stabilized even with changes in load, gas quality or gas preheating temperature with approximately constant NO _x emission values operate.

In the preferred embodiment is hereby the fuel used as Vormischbrennstoff and in variable mass flow ratio to the first and split second feedings. The feed of Premix fuel differs from the feed of pilot fuel, i. of fuel for the Realization of a pilot stage, in that premix fuel with a higher momentum, preferably across to the flow of combustion air, in the swirl chamber is introduced. When introducing fuel as a pilot fuel, however, the burner is in a Operated diffusion mode.

Preferably, the fuel is load-dependent distributes the first and second fuel feeds placed in the burner.

In a further preferred operation of the Brenners is in a first operating state in the Essentially the total amount of fuel over or the first fuel feeds supplied and over the first group of fuel outlets in the Combustion air flow introduced, and in one further operating state at least a part of total amount of fuel over at least one of second fuel supply to the second group of fuel discharge openings in the combustion air flow brought in.

If the burner is operated in a heat generator, so can in a part load condition of the heat generator of entire fuel over the first fuel feeds be fed, and in full load operation of the Heat generator the fuel on the first fuel supplies and one or more second fuel feeds be split.

In addition to the load-dependent distribution mentioned above fuel on the first and second Fuel feeds can be the distribution also control according to other company sizes. So can the Fuel, for example, depending on measured combustion chamber pulsations of a gas turbine, pollutant emissions, measured material temperatures, from that through a flame position sensor detected flame position or other measuring or Operating parameters on the first and second fuel feeds be distributed.

By the one or more second fuel feeds, by which the amount of premix fuel, the over the second group of fuel outlet openings is injected into the swirling space, and thus also the fuel pre-pressure - independent of the amount of premix fuel can be adjusted can, which flows over the first fuel supply, can be a simple adjustment of the mixture distribution and the quality of mixing to different boundary conditions to reach. Furthermore, by this configuration also a balance of different Wobbe numbers achieved by, for example, the first Fuel feeds a certain power or carry a certain volume flow and the rest of the Power or the volumetric flow over the second Fuel feeds is driven. By suitable Arrangement of the second fuel supply to the corresponding second groups of fuel outlet openings relative to the first fuel feeds with the first groups of fuel outlets can be the axial and radial Fuel distribution in the burner favorably influence. So it is possible in partial load operation in certain Areas of the burner outlet targeted enrichment of the mixture with fuel to achieve the Improve flame stability. At high burner load then the fuel can be distributed evenly, which results in low emissions.

By an embodiment in which several of the second fuel feeds independently with premix fuel can be applied, can be an even finer graduated adjustment of the distribution of the mixture and the Mix quality to different boundary conditions make.

Furthermore, the invention also includes such embodiments one in which next to first and second also third, fourth, etc. Brennstoffzuführugen available and be fueled independently.

A burner which can be used by way of example for carrying out the method according to the invention consists of a swirl generator for a combustion air flow, a swirl space and means for introducing fuel into the Combustion air flow, wherein the swirl generator combustion air inlet openings for the tangential in the Having swirling space entering combustion air flow, the means for introducing fuel into the Combustion air flow one or more first fuel feeds with a first group of im Essentially arranged in the direction of the burner axis Fuel outlet openings for a first amount of premix fuel include and the burner one or several second fuel feeds with a second Group of essentially in the direction of the burner axis arranged fuel outlet openings for a second fuel quantity, preferably a premix fuel quantity, which second fuel feeds independent of the first fuel supply (s) be acted upon with fuel is / are. The burner is characterized in the described Preferred variant characterized in that in the swirl chamber an inner body is arranged, wherein the fuel outlet openings at least a second fuel supply essentially in the direction of the burner axis distributed on the inner body are arranged. In which Inner body is a preferred Embodiment to a fuel lance, the Swirl space is arranged on the burner axis.

Preferably, one or more of the first Groups of fuel outlets in the area at least one of the combustion air inlet openings arranged.

Under an arrangement essentially in the direction the burner axis is in the present application a Arrangement to understand axes that are parallel or at an angle <45 ° to the burner axis.

In a possible embodiment of the exemplary Brenners are also some of the second fuel feeders right next to the first fuel feeds, preferably parallel to these, arranged. This should be at least a second fuel supply provided next to each first fuel supply be.

It goes without saying, however, that the second Fuel supplies also independent of the first fuel supply in a symmetrical arrangement can be provided on the swirl generator. The geometry the swirl generator is irrelevant here. So can conical swirl generators, as described in the beginning mentioned prior art documents are known, for example, with two, four or more Air inlet slots, are used. Others too Geometries, such as cylindrical swirl generators or cylindrical swirl generators with conical or cylindrical Inner bodies can be used.

Some of the second fuel feeds are in an embodiment of the burner on the outer shell of the swirl body and in particular to the Air inlet slots are arranged along this. Essential in the present burner is that the second fuel feeds a plurality of substantially in the direction of the burner axis distributed fuel outlet openings have sufficient To be able to achieve premixing. The outlet openings are usually on parallel or under one a conical shape of the swirl generator or inner body predetermined angle to the burner axis extending Axes.

Depending on the desired influence on the Premix may be the second fuel outlet openings the second fuel feeds in comparison to the first fuel outlets other mutual distances or flow cross sections exhibit. Especially with an arrangement in which right next to a first fuel feeder too provided at least a second fuel supply is, can the respective fuel outlets also the same mutual Have distances, but offset from each other be. This leads to a more uniform injection of the premix fuel into the swirl space. Farther For example, the first fuel outlet openings over the entire axial extent of Combustion air inlet openings, the second fuel outlet openings but only in a certain be arranged axial portion. In the same way it is also possible the first fuel outlet openings only in a first axial portion and the second fuel outlets only in a subsequent to the first subarea provide second axial portion - or vice versa. Different possibilities of influence on the Operation of the burner due to these different Design options, their combination no Practical limits are set, can the Refer to exemplary embodiments.

For the independent use of the first and second fuel feeds with the Premix fuel are these with different Equipped connections. Preferably, in addition Means for independent regulation or Control of premix fuel supply to the first and the second fuel supply lines. The different supply, for example, by a suitable control valve can be controlled.

Figur 1

schematisch ein Ausführungsbeispiel für einen Brenner, der mit dem erfindungsgemäßen Verfahren betrieben werden kann, im Längs- und Querschnitt;

Figur 2

ein Beispiel für den Gasaustritt aus den Austrittsöffnungen bei einer möglichen Betriebsweise des in Figur 1 dargestellten Brenners;

Figur 3

schematisch ein Beispiel für die Anordnung der Brennstoffzuführungen und der Brennstoffaustrittsöffnungen eines Brenners, der mit dem erfindungsgemäßen Verfahren betrieben werden kann;

Figuren 5 bis 7

Beispiele für die Anordnung der Brennstoffzuführungen und der Brennstoffaustrittsöffnungen eines Brenners, der mit dem erfindungsgemäßen Verfahren betrieben werden kann;

Figur 8

schematisch ein Beispiel für einen mit dem erfindungsgemäßen Verfahren betreibbaren Brenner mit einem zylindrischen Drallerzeuger;

Figur 9

ein Beispiel für eine Brennerbauform mit zylindrischem Drallkörper und konischem Innenkörper, wie sie mit dem erfindungsgemäßen Verfahren betrieben werden kann;

Figur 10

ein Beispiel für die Ausgestaltung eines geeigneten Brenners;

Figuren 11 bis 14

schematisch Beispiele für weitere Drallerzeugergeometrien, mit denen die vorliegende Erfindung verwirklicht werden kann;

Figuren 15 und 16

Drallerzeugergeometrien mit einem nachgeschalteten Vormischrohr, bei denen die Erfindung verwirklicht werden kann;

Figuren 17 und 18

schematisch zwei Beispiele für den Aufbau des Drallkörpers im Querschnitt, wie er bei einem geeigneten Brenner eingesetzt werden kann;

Figuren 19 bis 21

weitere Beispiele für die Ausgestaltung eines Brenners;

Figur 22

ein Beispiel für die Betriebsweise eines Brenners der Figuren 20 und 21; und

Figuren 23 und 24

schematisch zwei Beispiele für die Ausgestaltung der Brennstoffzuführungen zur Durchführung des erfindungsgemäßen Verfahrens.

The inventive method and burner, with which the method according to the invention can be carried out, will be explained in more detail below with reference to embodiments in conjunction with the drawings without limiting the general inventive concept. Hereby show:

FIG. 1

schematically an embodiment of a burner which can be operated by the method according to the invention, in longitudinal and cross-section;

FIG. 2

an example of the gas outlet from the outlet openings in a possible operation of the burner shown in Figure 1;

FIG. 3

schematically an example of the arrangement of the fuel supply lines and the fuel outlet openings of a burner, which can be operated by the method according to the invention;

FIGS. 5 to 7

Examples of the arrangement of the fuel supply lines and the fuel outlet openings of a burner, which can be operated by the method according to the invention;

FIG. 8

schematically an example of a burner operable with the inventive method burner with a cylindrical swirl generator;

FIG. 9

an example of a burner design with cylindrical swirl body and conical inner body, as they can be operated by the method according to the invention;

FIG. 10

an example of the design of a suitable burner;

FIGS. 11 to 14

schematically examples of further swirler geometries, with which the present invention can be realized;

FIGS. 15 and 16

Swirl generator geometries with a downstream premix tube, in which the invention can be realized;

FIGS. 17 and 18

schematically two examples of the structure of the swirl body in cross section, as it can be used in a suitable burner;

FIGS. 19 to 21

further examples of the design of a burner;

FIG. 22

an example of the operation of a burner of Figures 20 and 21; and

FIGS. 23 and 24

schematically two examples of the configuration of the fuel feeds for carrying out the method according to the invention.

Ways to carry out the invention

In the following figures, the burners are in strong Schematically illustrated embodiment, so that only in each case at a position for the respective explanation essential features highlighted are. The further design of the illustrated Brenner is the expert among others from the The prior art cited common documents that an integral part of the present Show description. Furthermore, at the Embodiments partly to the injection of gaseous fuel reference. It goes without saying however, that too liquid fuel over the fuel outlet openings in the combustion air stream can be introduced. The fuel will furthermore referred to as premix fuel; it understands itself that part of the total fuel amount in certain load ranges also as pilot fuel to further increase the flame stability can be introduced. Feeders for pilot fuel are not shown in any of the figures, as they are are not essential to the invention; in knowledge of Prior art, the expert but this without More in the example shown burner implement, if he deems it necessary.

FIG. 1 shows a first example of a burner represented, with the inventive method can be operated. FIG. 1a shows an arrangement the first 5 and second fuel feeds 7 for a cone-shaped swirl burner 1. In the outer formwork of this swirl body 1 is connected to the Einströmkanten the air inlet slots, as they Person skilled in the art are known, in addition the first feed 5 for a first premix fuel quantity P1 a second feed 7 for a second Premix fuel quantity P2 arranged. These two Feeder can be independently with each other Premix fuel, that is, for example the mass flow of the second premix fuel P2, which flows through the second supply 7, independently from the mass flow of the first premix fuel P1 can be adjusted by the first feeder 5. This is due to the different feed lines indicated by the arrows. It goes without saying itself, that preferably several of these feed pairs 5, 7 arranged symmetrically about the burner axis are. The fuel supply to the two feed channels, can independently over here not explicated control valves be adjusted from each other. The arrangement of Control valves is not shown in the example, the Professional but readily familiar.

In Figure 1b, the burner is in vertical section represented by the burner axis 3. In this Illustration are the two shells 1a, 1b of the swirl body to recognize. These are with the actual Burner axis 3 offset symmetry axes 3a, 3b arranged, such that between them air inlet slots 4 is formed for the combustion air 11 are. At such an air inlet slot 4 is in the manner known from the prior art, the first Feed channel 5 with the corresponding outlet openings 6 to recognize the premix fuel. Immediately adjacent to this first supply channel 5 is the second supply channel 7 with the corresponding second outlet openings 8 arranged. Both feed channels show with their outlet openings 6, 8 for incoming combustion air flow.

By grading the premix fuel quantities via feed channels which can be acted upon separately can reduce the penetration depth of the premix fuel P1, P2 in the combustion air flow over the one Feed channel large and small over the other feed channel be set. This is schematic in FIG illustrated, which figure the arrangement of Figure 1 represents in a possible mode of operation. in this connection the amount of fuel in the first supply channel 5 becomes higher set as in the second feed channel 7, so that the pressure and thus the exit velocity of the Fuel at the outlet openings 6 compared to the outlet openings 8 increases. The first premix fuel P1 from the first feed channel 5 thus penetrates deeper into the combustion air flow than the Premix fuel P2 from the second feed channel 7, as indicated in the figure. The same Effect can also be due to different opening diameter or flow cross sections of the respective Outlet openings are achieved, in which case the fuel quantities flowing through the two channels different penetration depth selected identical can be.

With this arrangement, thus, the mixing distribution and the mixing quality in the burner targeted be set.

FIG. 3 shows a variant of the arrangement of the feed channels and the outlet openings. Also in this Example is the conical swirl body 1 with each a first and a second supply channel 5, 7 for Illustration shown in a simplified form. The two feed channels are also here parallel next to each other on - not shown - tangential air inlet slot. In this arrangement the two feed channels have the same number of Holes n1 and n2 on. The holes are even distributed along the burner axis 3, wherein the axial arrangement of the holes 8 of the second feed 7 at a gap to the axial arrangement of the holes. 6 set the first premix fuel supply is. Of course, the number of holes n1 and n2 also be different from each other.

By the possibility of drilling the feed channels to arrange differently, to distribute or with can be provided with different diameters the axial and radial fuel distribution in the burner respectively at the burner exit purposefully influence.

So can the axial and radial fuel distribution for example, by a non-uniform arrangement the holes 8 along the second feed channel 7 and the burner axis 3 are affected, as in the the following figures is shown.

FIG. 4 shows an arrangement in which the Holes 6 of the first feed channel 5 in a conventional manner in the direction of the burner axis 3 in even mutual distance are distributed. The holes 8 of the second feed channel 7 are in this example only over the first half of the swirl space towards the Burner axis 3 distributed. Through this hole arrangement can an enrichment of the fuel mixture in the burner center by connecting this second stage - the Premix fuel supply via the second feed 7 - be achieved.

FIG. 5 shows a similar arrangement in which the Holes 8 of the second feed channel also, as in Figure 4 in the first region of the swirl space in the direction the burner axis 3 are arranged. In this example However, the holes 6 of the first feed channel. 5 not over the entire length of the swirl space in the direction the burner axis 3 distributed, but only in second, directed to the burner exit part. The Number n1 or n2 of the respective holes can vary depending on Requirements are selected. These can be the same or also be different.

A comparable embodiment with interchanged Arrangement of the outlet holes 6, 8 in the direction of Burner axis 1 show the figures 6 and 7. In particular in the arrangement of Figure 6, the enrichment can be the outer region of the burner, that is the of Combustion chamber facing area, with the second Reach level. Basically, with arrangements, as shown in Figures 4 to 7, a desired concentration gradient of the fuel be adjusted along the burner axis.

With an arrangement as shown in Figure 4 is also a supply of pilot fuel be carried out at low loads. In this case is approached with the stage that the fuel in inject the center of the burner. With increasing load then the second stage is switched on. At full load, in the most uniform fuel distribution is desired, then only with the second Level driven.

Figure 8 shows another example of the embodiment a burner according to the invention in strong schematic representation. In this example, a purely cylindrical swirl body 1 used. The two in the figure, indicated feeds 5, 7 with the first 6 and second outlet openings 8 can in be configured and arranged in the same way as this already in connection with the preceding Figures was explained.

Another embodiment of a burner, in this example using a cylindrical Swirl generator 1 with conical inner body 9, for the Implementation of the present method is exemplary shown in FIG. FIG. 9 shows this again with the first 5 and the second feed channel 7 with the corresponding outlet openings 6, 8. In the Embodiment of Figure 9 are these feed channels side by side in the outer formwork of the swirl body. 1 arranged.

FIG. 10 shows an example of an embodiment the burner according to the invention, wherein the second Feed channel 7 arranged on the cylindrical inner body 9 is.

The second supply channel 7 is in this case preferably arranged inside the outer wall of the inner body 9, although in this case too, as with the previous ones Examples a symmetrical distribution of several Feed channels 7 are selected around the burner axis 3 should. However, in this example it is also possible the second supply 7 centrally in the inner body. 9 let go, in which case the outlet openings 8 via corresponding radial channels for Twist space 2 must be formed. In the front itself tapered portion of the inner body 9 can also one or more additional outlet openings with a correspondingly separate feed for fuel be provided (as a pilot stage) or air.

FIGS. 11 to 14 schematically show examples for further swirl generator geometries with which the present invention can be realized. In the Figures are from top to bottom with a burner conical swirl body 1 and conical inner body 9, a burner with in the form of an inverted cone trained swirl body 1 and conical inner body 9, a burner with tulip-shaped and a burner with funnel-shaped swirl body 1 shown. at All of these burner geometries can be used as in the previous examples, the second feeds both in the swirl body 1 as well as in the inner body. 9 be arranged. All geometries shown here are common that the axial flow area of the Swirl space in the area of the swirl body to the burner outlet increases. This is not absolutely necessary Prerequisite for a premix burner, but is an advantageous embodiment of Swirl generator.

Furthermore, all burner geometries with a premix tube 10, as exemplified in FIG. 15 for a cone burner and in FIG. 16 for a cylindrical burner with conical Inner body 9 is illustrated.

Finally, FIGS. 17 and 18 show schematically two examples of the structure of a swirl body in cross-section, as with a burner can be used. In Figure 17 is a swirl body represented, which are offset from four against each other Shells 1a, 1b, 1c, 1d composed in the illustrated arrangement four tangential air inlet slots 4 form. The cups can be shown in the picture Cross-section different, for example circular segment, elliptical or oval, be formed. at the dargestllten configuration are the body part 1a, 1b, 1c, 1d arranged so that their respective central axes 3a, 3b, 3c, 3d offset to the actual Burner axis are arranged. The design of a Burner, with or without premix tube, with one such geometry can in detail that of EP 321 809 or EP 0780629.

FIG. 18 shows a monolithic swirl body 1 with tangential air inlet openings introduced therein 4 shown. The air inlet openings 4 For example, as milled air entry slots or as rows of air intake holes be educated.

The in the preceding and following examples cited combinations of feed channels as well as the arrangement or design of the outlet openings in the feed channels can be changed arbitrarily or combined with each other. That's the way to go All variants of the illustrated in Figures 4 to 7 Outlet opening arrangements also in the Apply embodiments of Figures 8 to 16. This applies to both the distribution, the number as well as the Arrangement of the individual outlet openings. Farther can be in all variants shown in the two Feed channels use different hole diameters. This way, in the stage, the one to absorb smaller amounts of fuel, a certain Form and a desired exit velocity be set. The combination possibilities of individual design variants are not here Set limits. The expert will be the appropriate Arrangement according to the desired application condition and select desired effects. In particular it is by no means mandatory, the outlet openings in the axial To arrange direction equidistant, as it is in all Drawings is implied. On the contrary it can prove to be highly beneficial, the outlet openings for the premix fuel in an arbitrary axial distribution or other Distribution rules, such as a geometric grading of the axial distances, to implement.

The same applies to the use of different Burner geometries or the combination of swirl generators with inner bodies or premix tubes. The expert is evident that the realization. the present Invention with different types of burners and combinations of spin bodies, inner bodies, Premix tubes and other known features of Burners is possible.

Further very advantageous embodiments of a Burner can be seen in Figures 19 to 21. The illustrated burners include the cone-shaped Swirl body 1, in its outer formwork at the inflow edges the air inlet slots a first group of Outlet openings 6 are arranged for premixed gas. The burners are still with a central fuel lance 12 fitted, the at their combustion chamber side End, i. at its tip, have a nozzle can - as in this example - be used for one liquid fuel 13 or for a pilot fuel is usable. Around this nozzle around in known Way outlet openings for shielding air 14 is provided be. In addition to the fuel supplies to the first Group of outlet openings 6 and a fuel supply for injection liquid fuel 13 at the Tip of the fuel lance 12 have the illustrated Burner another fuel supply to a second group of outlet openings 8 in the fuel lance 12 on. The outlet openings 8 of the second Group are essentially in the direction of the burner axis arranged in the lateral surface of the fuel lance 12, as can be seen in Figures 19 to 21, and preferably radially symmetrical about the axis of Fuel lance 12 distributed. They allow the radial directed from the fuel lance 12 outward Injecting fuel into the swirl chamber. The number and size of these outlet openings 8 and their Distribution on the fuel lance 12 - in axial Direction and circumferential direction - is dependent on the respective requirements of the burner such as extinction limits, Pulsations and setback limits selected.

The fuel lance 12 may be relatively far in extend the swirl space (see Figures 19 and 20; "Long Lance EV Brenner ") or just a short piece in protrude the swirl space (Fig. 21). In both cases, the second group of outlet openings 8 preferably in rear, i. farthest from the combustion chamber removed, area of the swirl space at the fuel lance 12 arranged as indicated in the figures.

Of course, can also be in these embodiments the fuel supply to the first Group of outlet openings 6 regardless of the Fuel supply to the second group of outlet openings Control or regulate with fuel.

The embodiment of Fig. 19 leaves a very advantageous stepped operation of the burner, at both the fuel feeds to the first Group of outlet openings 6 and the fuel feeds to the second group of outlet openings 8 are fed with premix gas. The Independent Control possibility of the fuel supply to the first and second group of outlet openings 6, 8 allows one to the respective operating conditions of the Burner or the burner using the system optimally adapted mode of operation. The second group of Outlets 8 are located on the fuel lance 12 in this example, outlet openings of the first Group of outlet openings 6 on the swirl body. 1 opposite, so that the first and second group of Outlet openings 6, 8 in certain operating conditions for example, also exclusively, i. without the each other group, be fueled can.

In principle, the one shown in the figure Burner with appropriate supply of fuel and corresponding embodiment of the second group of Outlets over these outlet openings 8 also be operated in diffusion mode. By the spatial Separation of the outlet openings 8 of the injection liquid fuel 13 at the top of the fuel lance 12 can be contrasted in this case known burners the penetration of fuel droplets or fuel vapor into the fuel supply system for the second group of outlet openings 8 avoid.

FIG. 20 shows an embodiment of a burner, which are also in the very advantageous tiered Operation can be operated. At the second Group of outlet openings 8 opposite Regions of the swirl body 1 are the outlet openings 6 closed or there are no outlet openings 6 provided because their function of the outlet openings 8 is taken on the fuel lance 12. Figure 21 shows the same burner with shortened Fuel lance 12, for the same operation is trained.

In the operation of these burners are both groups of outlet openings 6, 8 with premixed gas applied. Ignition and start of the burner take place in a mode of operation in which the premix gas mainly via the outlet openings 8 at the Fuel lance 12, in the following also as stage 1 designated, is introduced into the swirl space. at increasing load is the supply of premixed gas to Level 1 decreases and the supply of premix gas over the first group of outlet openings 6, in the following referred to as level 2, increased. Such a distribution of premix fuel to stages 1 and 2 in Depending on the operating status of the burner can are taken from FIG. 22 by way of example.

In this way, for example, a gas turbine can be with such a burner from the ignition operate up to the base load without a pilot stage.

The supply of fuel to stages 1 and 2 is controlled independently via suitable valves or regulated.

Figures 23 and 24 show examples of the feed a fuel amount P0 to the burner. By both Examples branches the fuel line to the Total fuel quantity P0 to a fuel quantity P1 for the first group of outlet openings 6 and on a fuel amount P2 for the second group of Distribute outlet openings 8.

In Figure 23, the discontinuation of the distribution or mass flow ratio via one valve 15 and 16 in each of the branches. Figure 24 shows an embodiment in which a valve 16 before the Branching to set the total fuel quantity P0 and another valve 15 in the branch to first group of outlet openings 6 is arranged. By controlling the valve 15 can be here also the Change the mass flow ratio between P1 and P2. Of course, in this example, the valve 15 also in the branch to the second group of Outlets 8 may be arranged.

Furthermore, can be about such an arrangement also several burners simultaneously in the set Supply mass flow ratio with fuel, as by the dashed lines in the figures is indicated.

In both exemplary embodiments the mass flow ratio P1 / P2 by controlling the Valves depending on the operating condition of the Brenner changed. The change of the mass flow ratio may vary depending on different measuring and operating characteristics are controlled or regulated, like this already in a previous part of the this description has been carried out. The Embodiments shown are independent of the Burner geometry and can be with all burners of use previous embodiments.

LIST OF REFERENCE NUMBERS

1

swirl generator

1a

Swirl generator partial body

1b

Swirl generator partial body

1c

Swirl generator partial body

1d

Swirl generator partial body

2

swirl space

3

Brenner

3a

Axle of a swirl generator part body

3b

Axle of a swirl generator part body

3c

Axle of a swirl generator part body

3d

Axle of a swirl generator part body

4

Inlet openings / air slots

5

first fuel feeds

6

first fuel outlet openings

7

second fuel feeds

8th

second fuel outlet openings

9

inner body

10

premix

11

combustion air

12

fuel lance

13

liquid fuel

14

Abschirmluft

15

control valve

16

control valve

P0

Total amount of fuel

P1

first premix fuel

P2

second premix fuel

n1

first number of holes

n2

second number of holes

Claims (7)

1. Method of operating a burner, which has at least one first fuel supply conduit (5) with a first group of fuel outlet openings (6), essentially arranged in the direction of a burner centre line (3), for the introduction of a first premix fuel quantity into a swirl space and one or a plurality of second fuel supply conduits (7) with a second group of fuel outlet openings (8) essentially arranged in the direction of the burner centre line (3), it being possible to admit fuel to the second fuel supply conduits (7) independently of the first fuel supply conduit (5), in which the supply of the fuel via the first fuel supply conduits (5) is controlled, in an open-chain or closed-loop manner, separately from the supply of the fuel via the second fuel supply conduits (7), characterized in that the same fuel is supplied to the first and second fuel supply conduits (5, 7).
2. Method according to Claim 1, characterized in that premix fuel is supplied to the first fuel supply conduit or conduits (5) and the second fuel supply conduit or conduits (7).
3. Method according to Claim 1 or 2, characterized in that gaseous fuel is supplied to the first fuel supply conduit or conduits (5) and the second fuel supply conduit or conduits (7).
4. Method according to one of Claims 1 to 3, characterized in that the fuel is introduced into the burner in such a way that it is distributed between the first (5) and second fuel supply conduits (7) as a function of the load.
5. Method according to one of Claims 1 to 3, characterized in that the fuel is introduced into the burner in such a way that it is distributed, as a function of the burner air/fuel ratio, between the first (5) and second fuel supply conduits (7).
6. Method according to one of Claims 1 to 3, characterized in that in a first operating condition, the total fuel quantity is essentially supplied to the burner via the first fuel supply conduit or conduits (5) and is introduced into the combustion air flow via the first group of fuel outlet openings (6), and in that, in a further operating condition, at least a part of the total fuel quantity is supplied to the burner via at least one of the second fuel supply conduits (7) with the second group of fuel outlet openings (8).
7. Method of operating a burner according to Claims 1 to 3 in a heat generator, characterized in that, in a partial load condition of the heat generator, the total fuel is supplied via the first fuel supply conduits (5), and in that, in at least the full-load operation of the heat generator, the fuel is divided between the first fuel supply conduits (5) and at least one second fuel supply conduits (7).

Images