DE102011082884A1 - Burner and gas turbine with such a burner - Google Patents

Abstract

A burner (1) and gas turbine having such a burner, the burner having a combustion chamber (20) and an axially adjacent flame holder (30; 30 ') for stabilizing a flame generated by combustion of a fuel in the combustion chamber (20) ( F) has. With the invention, a burner and a gas turbine provided therewith are provided so that they have an increased service life. This is u.a. characterized in that at least one elongated recess is provided in or adjacent to a flame-bonding region (31; 31 ') of the flame holder exposed to the flame so that it provides a thermal expansion space for material of the flame holder located in the flame-bonding region.

Description

The invention relates to a burner according to the preamble of claim 1 and a gas turbine equipped with such a burner.

A burner of the type mentioned above is eg in DE 10 2009 046 066 A1 described. In this document, the burner is integrated into an air-gas mixture fuel gas turbine used. The burner has a combustion chamber and a flame holder (in the form of a burner head plate) axially adjacent the combustion chamber for stabilizing the combustion of a flame produced by burning the fuel in the combustion chamber.

In burners, it is desirable to connect the flame to a flame holder adjacent or axially delimiting the combustion chamber of the burner in order to ensure flame stability and prevent migration of a heat release zone. This is advantageously assisted when a combustor-facing, preferably metal surface of the flame holder is heated to a high temperature, as this will aid the reaction process by preventing known reaction quenching, where heat loss of the reaction flame front reduces available energy for further molecular reactions. If this heat loss exceeds a critical value, the entire reaction process is stopped. By attaching the flame to a hot surface, it can deliver heat energy to the molecules in the reaction, thus maintaining reactions during modes in which unbounded flames would stop without an external source of energy.

However, the high temperature gradients associated with such flame bond configurations may cause problems such that concentrations of mechanical stresses in the flame holder may increase beyond acceptable limits and thereby result in a reduction in the life of the flame holder and, thus, the burner.

The invention has for its object to provide a burner according to the preamble of claim 1 so that it has an increased life. The invention is also based on the object to provide a equipped with such a burner gas turbine with a correspondingly increased lifetime.

The o.g. Problems are solved with a burner according to claim 1 or with a gas turbine according to claim 10. Further developments of the invention are defined in the dependent claims.

According to a first aspect of the invention, there is provided a burner having a combustion chamber and a flame holder axially adjacent to the combustion chamber for stably bonding thereto a flame generated by burning a fuel in the combustion chamber. The burner according to the invention is characterized in that at least one elongated depression is provided in or adjacent to a flame attachment region of the flame holder exposed to the flame, so that the depression provides a thermal expansion space for material of the flame holder located in the flame bonding region.

By providing the thermal expansion space in the form of the at least one recess, the material of the flame holder in the flame-bonding area is not limited in its heating-related extent from the rest of the flame holder, which is not in contact with the flame and therefore cooler than the flame-bonding area. As a result, beyond acceptable limit values, increasing concentrations of mechanical stresses in the flame holder are avoided, thus increasing its service life.

The flame holder is preferably formed in the form of a plate and in particular in the form of a circular plate. The flame holder is also preferably made of metal. Alternatively, e.g. also ceramic conceivable.

The at least one elongated recess is preferably formed in the form of a groove or a slot. The at least one elongated recess can be made by cutting, in particular by an exciting machining, or by primary molding, in particular by casting molds.

According to one embodiment of the burner according to the invention, the at least one depression extends in a circular manner along its length.

According to the invention, it has been recognized that the flame bonding area is normally circular and of a diameter based on about 25% of the characteristic diameter of the combustion chamber. Thus, provided by a circular or circular course of the at least one recess the material of the flame-bonding area around the thermal expansion space and thus improves the voltage prevention.

According to a further embodiment of the burner according to the invention, the at least one depression runs continuously along its length.

A continuous course has advantages with regard to the provision of a thermal expansion space that is as general as possible. However, for stability reasons, a discontinuous course of the at least one depression as a compromise solution conceivable.

According to yet another embodiment of the burner according to the invention, the at least one recess has a depth which is greater than a width thereof. Preferably, the depth and width of the at least one recess are related to the size of the flame-bonding area, which, as mentioned, is normally circular and of a diameter based on about 25% of the characteristic diameter of the combustion chamber.

According to yet another embodiment of the burner according to the invention, the at least one depression has an undercut, so that a cross-section of the depression in a bottom region of the depression is greater than in an input region of the depression.

Here, the hot flame more material or a larger area is exposed, so that more energy storage is available, the increased thermal expansion is compensated by the larger space in the bottom region of the recess.

In accordance with one embodiment of the burner according to the invention, the flame holder has a first surface facing the combustion chamber and a second surface facing away from the combustion chamber, wherein the at least one recess is formed in the first surface. According to an alternative embodiment of the burner according to the invention, the at least one depression is formed in the second surface.

According to yet another embodiment of the burner according to the invention, a plurality of depressions are provided by the at least one depression and the at least one depression, wherein the depressions are arranged in or adjacent to the flame attachment region of the flame holder, and the depressions are each circular in their length and concentric with one another run.

With this embodiment of the invention, wherein a plurality of circularly extending and mutually concentric thermal expansion spaces are provided, a particularly effective stress avoidance is achieved. Each of the material rings formed between the recesses is heated by the hot flame and thus represents a flame-stabilizing energy storage, each material ring can expand radially outwardly in its immediately adjacent thermal expansion space.

According to yet another embodiment of the burner according to the invention, the burner is adapted for use in a gas turbine using gas as an air-gas mixture. In other words, the burner is designed as a gas turbine burner.

According to a second aspect of the invention, a gas turbine with a burner according to one, several or all of the previously described embodiments of the invention is provided in any conceivable combination.

In summary, the invention limits stress concentrations by selectively removing material to allow for thermal expansion of the hot material (e.g., metal) of the flame bond area, thereby reducing stress concentrations. The invention is preferably applicable to a burner for a gas turbine, but also to other types of machines that require a controlled flame source, and any configuration in which a flame is configured to be connected to a preferably metallic surface.

The invention expressly extends to such embodiments, which are not given by combinations of features of explicit back references of the claims, whereby the disclosed features of the invention - as far as is technically feasible - can be combined with each other.

In the following the invention will be described with reference to preferred embodiments and with reference to the accompanying figures.

1 shows a view of a burner of a gas turbine according to an embodiment of the invention.

2 shows a schematic detail view of the burner of 1 ,

3 shows a perspective view of a flame holder according to an embodiment of the invention.

4 shows a perspective sectional view of the flame holder of 3 ,

5 shows a sectional view of a flame holder according to another embodiment of the invention.

6 shows a perspective sectional view of the flame holder of 5 ,

1 shows a view of a burner 1 a gas turbine (not fully shown) according to an embodiment of the invention. 2 shows a schematic detailed view of the burner 1 from 1 ,

How out 1 and 2 can be seen during operation of the gas turbine or the burner 1 compressed air discharged from a compressor (not shown) in the form of air flows LS1 and LS2 air passages (not shown) of the burner 1 and one or more swirl generator (s) 10 (please refer 2 ) of the burner 1 fed and mixed with fuel gas to form an air-gas mixture as fuel. An example of such a burner is in GB 2 454 247 A described. An example of a swirl generator is in DE 10 2009 045 950 A1 described.

The combustion of the fuel takes place in a combustion chamber 20 of the burner 1 instead, wherein a flame F (generated in FIG 2 indicated as a dashed line) for stabilizing this on a flame holder 30 . 30 ' is connected. The flame holder 30 . 30 ' is axially adjacent to the combustion chamber 20 at or limits this axially. The flame holder 30 . 30 ' is formed in the form of a circular metal plate.

The connection of the flame F occurs at the flame holder 30 . 30 ' especially in a flame bonding area 31 . 31 ' of the flame holder 30 . 30 ' on. The flame F is realized by means of the compressor discharge air by means of or the swirl generator (s) 10 lent swirl, wherein a swirl flow through a premix tube 40 , by means of a dome part 50 to a flame tube 60 of the burner 1 is attached, from the swirl generator 10 out into the fire tube 60 is directed.

The flame contact area in contact with the flame F 31 . 31 ' can experience temperatures that cause thermal expansion in the flame bonding area 31 . 31 ' located metal material of the flame holder 30 . 30 ' to lead.

In a conventional flame holder, the expanding material of the flame bonding area would be limited in extent by the remainder of the flame holder, which is not in contact with the flame and therefore cooler than the flame bonding area, and thus result in significant stress concentrations and hence life reduction.

By the invention, too high voltage levels in a boundary region between the flame bonding area 31 . 31 ' and the rest of the flame holder 30 . 30 ' avoided.

The flame holder according to the invention 30 . 30 ' has for this purpose in or adjacent to the flame F exposed flame area 31 . 31 ' at least one elongated depression 32 . 33 ( 3 and 4 : 32a - 32d such as 5 and 6 : 33a - 33c ) on, leaving the recess 32 . 33 a thermal expansion space for in the flame bonding area 31 . 31 ' material of the flame holder 30 . 30 ' provides.

By providing the thermal expansion space in the form of at least one recess 32 . 33 is that in the flame connection area 31 . 31 ' located material of the flame holder 30 . 30 ' from the rest of the flame holder 30 . 30 ' which is not in contact with the flame F and therefore cooler than the flame bonding area 31 . 31 ' is not limited in its warming-related extent. Thus, beyond acceptable limits, increasing concentrations of mechanical stresses in the flame holder become 30 . 30 ' avoided and thus increases its life.

In the 3 and 4 is a first embodiment of the flame holder according to the invention 30 shown having a plurality (here four) of elongated depressions 32a . 32b . 32c . 32d having.

More specifically, the flame holder points 30 one the flame connection area 31 having the combustion chamber 20 facing first surface 30a and one of the combustion chamber 20 remote second surface 30b on, with the wells 32a - 32d in the first area 30a are formed. According to an embodiment of the invention, not shown, the depressions 32a - 32d alternatively in the second area 30b be educated.

The wells 32a - 32d are in and / or adjacent to the flame bonding area 31 of the flame holder 30 arranged and run along their length each circular and concentric with each other. In addition, the wells extend 32a - 32d their length continuously.

The wells 32a - 32d are each formed in the form of a groove or a slot and can be prepared by separation, in particular by an exciting machining, or by primary molding, in particular by casting molds.

Each of the wells 32a - 32d has a depth T that is greater than a width W of this (see 5 ). Preferably, the depth T and the width W are the size of the flame-bonding area 31 which is substantially circular and of a diameter corresponding to about 25% of the characteristic diameter of the combustion chamber 20 based.

In conclusion, according to the 3 and 4 the flame connection area 31 and / or directly adjacent areas of the flame holder 30 a number of raked or preformed concentric recesses 32a - 32d on the flame connection side. These depressions 32a - 32d may be provided in a number greater than or equal to one. The wells 32a - 32d may be of any shape suitable for promoting or promoting unobstructed thermal expansion. The wells 32a - 32d have appropriate corner and corner radii to minimize local stress concentrations.

During operation of the burner 1 will be in the 3 and 4 shown depressions 32a - 32d subjected to the high-temperature gas of the flame F. The ring-shaped metallic material (rings 34 ) between the wells 32a - 32d is narrow in width and faces the flame F. At each of these rings 34 the flame connection creates a high temperature and therefore becomes a thermal expansion of the ring 34 cause. The wells 32a - 32d allow the heated material of the rings 34 Without a physical restriction due to the cooler material outside the flame attachment area, as in the case without depressions 31 - Can expand radially outward.

In the 5 and 6 is a second embodiment of the flame holder according to the invention 30 ' which is shown in and / or adjacent to its Flammenanbindungsbereich exposed to the flame F. 31 ' a plurality (here three) of elongated depressions 33a . 33b . 33c having.

The flame holder 30 ' according to the second embodiment of the invention is identical to the flame holder except for some differences 30 formed according to the first embodiment of the invention. Therefore, in the following only these differences are shown, wherein the same components are provided with the same reference numerals and differences by other reference numerals or addition of an apostrophe are identified.

The wells 33a - 33c each have an undercut, so that the respective cross-section of the wells 33a - 33c in a respective floor area 33.2 the wells 33a - 33c is greater than in a respective entrance area 33.1 the wells 33a - 33c , as in 5 shown.

In the case of the design of the flame holder 30 ' with the undercuts in the wells 33a - 33c the hot flame F is exposed to more material or have the rings 35 a larger the hot flame F facing surface, so that more energy storage is available. The resulting increased thermal expansion is due to the larger space in each floor area 33.2 the wells 33a - 33c compensated.

Finally, according to some embodiments of the invention, there is provided a flame retainer plate, wherein concentric circular recesses (eg, grooves or slits) are formed at a flame bonding site or in areas near it by separation or prototyping, and wherein the recesses or recesses are formed Recesses are continuous or discontinuous and usually formed with a depth greater than their width. The recesses or recesses may have different geometries such that they promote unimpeded thermal expansion. The concentric circular depressions or recesses may be introduced from a flame attachment side or alternatively from a non-flame attachment side of the flame holder. Furthermore, the concentric circular recesses or recesses may have respective undercuts.

LIST OF REFERENCE NUMBERS

1

 burner

10

 swirl generator

20

 combustion chamber

30; 30 '

 flame holder

30a; 30a '

 first surface

30b; 30b '

 second surface

31; 31 '

 Flame attachment region

32

 Deepening (general)

32a

 deepening

32b

 deepening

32c

 deepening

32d

 deepening

33

 Deepening (general)

33a

 deepening

33b

 deepening

33c

 deepening

33.1

 entrance area

33.2

 floor area

34; 35

 ring

40

 premix

50

 dome part

60

 flame tube

F

 flame

T

 depth

W

 width

LS1, LS2

 airflow

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102009046066 A1 [0002]
• GB 2454247A [0033]
• DE 102009045950 A1 [0033]

Claims (10)

Burner ( 1 ) with a combustion chamber ( 20 ) and one axially to the combustion chamber ( 20 ) adjacent flame holder ( 30 ; 30 ' ) for stabilizing a fuel by burning it in the combustion chamber ( 20 ) produced flame (F), characterized in that in or adjacent to one of the flame (F) exposed flame bonding area ( 31 ; 31 ' ) of the flame holder ( 30 ; 30 ' ) at least one elongated depression ( 32 ; 33 ), so that the recess ( 32 ; 33 ) a thermal expansion space for in the flame bonding area ( 31 ; 31 ' ) located material of the flame holder ( 30 ; 30 ' ). Burner ( 1 ) according to claim 1, wherein the at least one recess ( 32 ; 33 ) is circular in length. Burner ( 1 ) according to claim 1 or 2, wherein the at least one recess ( 32 ; 33 ) runs continuously along its length. Burner ( 1 ) according to one of claims 1 to 3, wherein the at least one recess ( 32 ; 33 ) has a depth (T) greater than a width (W) thereof. Burner ( 1 ) according to one of claims 1 to 4, wherein the at least one recess ( 33 ) has an undercut, so that a cross section of the recess ( 33 ) in a ground area ( 33.2 ) of the depression ( 33 ) is larger than in an entrance area ( 33.1 ) of the depression ( 33 ). Burner ( 1 ) according to one of claims 1 to 5, wherein the flame holder ( 30 ; 30 ' ) one the flame bonding area ( 31 ; 31 ' ) having the combustion chamber ( 20 ) facing first surface ( 30a ; 30a ' ) and one of the combustion chamber ( 20 ) facing away from the second surface ( 30b ; 30b ' ), and wherein the at least one recess ( 32 ; 33 ) in the first area ( 30a ; 30a ' ) is trained. Burner ( 1 ) according to one of claims 1 to 5, wherein the flame holder ( 30 ; 30 ' ) one the flame bonding area ( 31 ; 31 ' ) having the combustion chamber ( 20 ) facing first surface ( 30a ; 30a ' ) and one of the combustion chamber ( 20 ) facing away from the second surface ( 30b ; 30b ' ), and wherein the at least one recess ( 32 ; 33 ) in the second area ( 30b ; 30b ' ) is trained. Burner ( 1 ) according to one of claims 1 to 7, wherein a plurality of depressions ( 32a - 32d ; 33a - 33c ) of the at least one recess ( 32 ; 33 ), the depressions ( 32a - 32d ; 33a - 33c ) in or adjacent to the flame bonding area ( 31 ; 31 ' ) of the flame holder ( 30 ; 30 ' ) are arranged, and wherein the depressions ( 32a - 32d ; 33a - 33c ) are each circular in their length and concentric with each other. Burner ( 1 ) according to one of claims 1 to 8, wherein the burner ( 1 ) is adapted for use in a gas turbine using gas as an air / gas mixture. Gas turbine with a burner ( 1 ) according to one of claims 1 to 9.

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