JPH1114056A - Gas turbine combustor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out positioning of open ends of flame propagation tubes and inner wall surfaces of liners easily and accurately by axially dividing the flame propagation tubes in halves and mounting short-tube like support members (liner collars) on flame propagation tube inserting openings of the liners and forcibly bringing stoppers of the flame propagation tubes come into contact with the liner collars. SOLUTION: In combustors 2, 2a, in the outside of combustor liners 12, 12a which have a cylindrical shape, high pressure air 100 flows from above to below, while in the inside of the combustor liners 12, 12a, a combustion gas 103 flows from below to above. Flame propagation tubes 15, 15a having a two-split structure are provided for communicating these combustor liners 12, 12a and flame propagation openings 18a, 18b are formed in liner collars 19, 19a. In such a construction, the flame propagation tubes 15, 15a are provided with collar stoppers 20, 20a and retainer stoppers 21, 21a. The retainer stoppers 21, 21a are forcibly moved by the retainers 22, 22a so that collar stoppers 20, 20a and liner collars 19, 19a are brought into contact with each other thus enabling positioning of the flame propagation tubes 15, 15a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine combustor, and more particularly to a gas turbine combustor in which a plurality of combustors for burning fuel with air are connected via a flame propagation tube.

[0002]

2. Description of the Related Art Many gas turbines are provided with a plurality of combustors. In each of the combustors, fuel and compressed air are reacted to generate a high-temperature gas.

[0003] The combustors are arranged in a circle around the axis of the gas turbine, and all adjacent combustors are connected by a connecting pipe, and a flame propagation pipe is installed inside the connecting pipe. The flame propagation tube is formed in a tubular shape, and has a structure in which a combustion gas can pass through the tube due to a pressure difference of a connected combustor.

[0004] When the gas turbine is started, the rotation speed is increased to the ignition rotation speed by an external drive device. Thereafter, fuel and air are introduced into all combustors. And spark the spark plug installed in one or two combustors,
Initiate the combustion reaction. When the combustion reaction starts in the combustor, high-temperature gas is generated, and the pressure inside the combustor increases.

[0005] When the adjacent combustor is not ignited, the high-temperature combustion gas flows into the unignited combustor through the flame propagation tube due to the pressure difference from the ignited combustor. Thus, starting with the ignition of only one or two combustors, each adjacent combustor is ignited one after another. The presence of the flame propagation tube can reduce the number of spark plugs and cost. Further, even if a certain combustor is misfiring during operation, reignition can be immediately performed by high-temperature combustion gas from an adjacent combustor.

[0006] Theoretically, once all combustors have ignited, the pressure in each combustor is equal and the flow of combustion gases through the flame spreader stops. However, in actual gas turbines, differences in the shapes of adjacent combustors, air and fuel flow rates are due to variations in the combination of parts manufactured within tolerances and manufacturing tolerances of the turbine vane throat area. Inevitably, a pressure difference is generated between the combustors, and the combustion gas may continuously flow inside the flame propagation tube connecting the combustors. The combustion gas temperature is up to 150
Since the temperature is about 0 ° C., if the combustion gas and the flame continuously flow through the flame propagation tube, the flame propagation tube may be damaged.

[0007] One method for suppressing the continuous gas flow in the flame propagation tube is to provide a cooling hole in the flame propagation tube, as shown as a conventional example in Japanese Patent Application Laid-Open No. 3-158619. is there. Compressed air at a high-pressure chamber pressure in which the combustor and the flame propagation tube are installed flows into the flame propagation tube from the cooling hole, and lowers the temperature of the combustion gas and reduces the pressure difference between adjacent combustors. When the differential pressure decreases, the amount of combustion gas flowing in the flame propagation tube decreases, and it becomes possible to prevent the temperature of the flame propagation tube from rising. In addition, since the flame propagating tube is cooled by the air flowing from the cooling hole, the reliability is improved.

However, the cooling air lowers the temperature of the combustion gas in the flame propagation tube when the combustor is ignited, and also reduces the flow rate of the combustion gas in the flame propagation tube to reduce the pressure difference between the combustors. In some cases, it may interfere with the original purpose of the flame propagation tube to propagate the flame. Therefore, in Japanese Patent Application Laid-Open No. H3-158619, the flame propagation tube has a double structure to create a film-like air flow between the tube wall and the combustion gas, thereby protecting the flame propagation tube without lowering the combustion gas temperature. doing.

[0009]

The flame transmission tube provided with a cooling hole has a basic idea of making the combustion gas difficult to flow, whereas the flame propagation tube provided with the film cooling as described above. The pipe has a concept of isolating the hot gas from the flame propagation pipe wall by a film air flow while flowing a high-temperature combustion gas in the center of the pipe. Therefore, one end of the flame propagation tube opened to the high-pressure side combustor liner is directly exposed to the high-temperature combustion gas upstream of the position where the film cooling air flow starts. In order to lower the tube wall temperature in that portion, it is conceivable to flow cooling air between the combustor liner and the flame propagation tube. However, if the positional relationship between the combustor liner and the flame propagation tube fluctuates, not only will effective cooling become difficult, but also the cooling air flow will block the opening of the flame propagation tube like an air curtain, reducing the flame propagation performance. May be caused.

In order to improve the positioning accuracy between the combustor liner and the flame propagation tube, Japanese Patent Application Laid-Open No. 58-168822 discloses that the flame propagation tube is fixed to an intermediate cylinder integrated with the combustor liner. In the present invention, there is shown a structure for positioning the combustor liner and the flame propagation tube by a simpler method and improving disassembly / assembly.

[0011]

The present invention comprises a liner that produces combustion gas and through which high-temperature combustion gas flows, and an outer cylinder that is disposed outside the liner and forms a compressed air flow path together with the liner. In a gas turbine combustor in which a plurality of combustors are arranged and a flame propagation tube communicating between liners of these adjacent combustors is installed, the flame propagation tube is divided into two in the axial direction, and a stopper is provided on the flame propagation tube. A short tubular support member (hereinafter, referred to as a liner collar) is provided at the flame propagation tube insertion port of the liner, and a stopper of the flame propagation tube is pressed against the liner collar to thereby open the flame propagation tube with the open end of the liner. Easy and accurate positioning with the wall.

Also, a part of the flame propagation tube or a member for pressing the stopper of the flame propagation tube against the liner collar is made of an elastic body, so that the stress in the flame propagation tube in the axial direction is reduced.

Further, the opening end of the flame propagation tube is positioned so as to be located radially outward of the liner from the inner wall of the liner, and a cooling hole is provided in a stopper or a liner collar of the flame propagation tube. Between the flame tubes,
Cooling air is allowed to flow in the direction along the axial direction of the flame propagation tube, and the center of the flame propagation tube is subjected to film cooling so that the flame propagation tube does not interfere with the original purpose of the flame propagation tube. Protect from hot combustion gases.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A gas turbine combustor according to an embodiment of the present invention will be described with reference to a sectional view shown in FIG. The gas turbine for power generation is composed of a compressor 1, a combustor 2, and a turbine 3, and the generator 4 is rotated by the output of the turbine to obtain electric power. A large gas turbine for power generation or the like is provided with a plurality of combustors, two of which are shown here. The combustor 2 is stored in a gas turbine casing 5, a combustor casing 6, and a combustor cover 7.
A diffusion pilot burner 8 is provided at the center of the upstream end of the combustor 2, and an annular premix burner 9 is provided on the outer periphery thereof. The premix burner 9 includes a plurality of premix burner fuel nozzles 10 and a flame stabilizer 11. Downstream of the premix burner is a combustor liner 12 that separates unburned air from burned combustion gases. An outer wall for forming an air flow path and controlling the flow outside the combustor liner (hereinafter referred to as a flow sleeve)
There are thirteen.

The high pressure air 100 from the compressor 1 passes through a generally annular space between the flow sleeve 13 and the combustor liner 12 and is used for convective cooling of the combustor liner 12 before the air 101 for the diffusion pilot burner. The premixed burner air 102 is supplied into the combustor and used as combustion air. Burned combustion gas 103
Is supplied to the turbine 3 via the transition piece 14 through the inside of the combustor liner 12.

The fuel system includes a main fuel system 200, a fuel system 201 for a diffusion pilot burner, and a fuel system 202 for a premix burner, which are branched from the main fuel system 200. The pressure control valve 20 is provided in the fuel system 201 for the diffusion pilot burner.
4, a flow control valve 205 is provided. Pressure regulating valve 2
04 also functions as a fuel cutoff valve. The premix burner fuel system 202 is provided with a pressure control valve 206 and a flow control valve 207. The pressure adjustment valve 206 also functions as a fuel cutoff valve.

The combustor 2 and a combustor 2a adjacent thereto
The combustor outer cylinders 6 are connected to each other by a connecting pipe 16, and a flame propagation pipe 15 for connecting the combustor liners 12 is installed inside the connecting pipes 16. This flame propagation tube is formed in a tubular shape, and has a structure in which a combustion gas can pass through the tube by a pressure difference between two connected combustors.

When the gas turbine is started, the rotation speed is increased to the ignition rotation speed by an external drive device. Thereafter, fuel and air are introduced into all combustors. And combustor 2
The spark plug 17 placed in the combustor 2 is sparked to start the combustion reaction in the combustor 2. When the combustion reaction starts in the combustor 2, high-temperature gas is generated, so that the pressure inside the combustor 2 increases. If the combustor 2a is not ignited, the ignited combustor 2a
And a pressure difference is generated between Due to this pressure difference, a part of the combustion gas 103 is sent into the combustor 2a through the inside of the flame propagation tube 15, and ignites a mixture of fuel and air.
Similarly, all the combustors not shown are ignited.
The presence of the flame propagation tube can reduce the number of spark plugs and cost. Further, even if a certain combustor is misfired during operation, re-ignition can be immediately performed by the high-temperature combustion gas from the adjacent combustor.

Theoretically, once all the combustors have been ignited, their pressures are equal and the flow of combustion gases through the flame tube 15 stops. However, in an actual gas turbine, a pressure difference is generated between the combustors 2 and 2a due to differences in shapes of adjacent combustors, air and fuel flow rates, and the inside of the flame propagation tube 15 connecting the combustors is formed. Combustion gases may flow continuously.

Next, in one embodiment of the present invention,
The details of the part related to the flame propagation tube 15 and the combustor liner 12 will be described with reference to FIG. 1 which are the same as those in FIG. 2 are denoted by the same reference numerals. The components of the combustor 2a shown on the right side of FIG. 1 are distinguished by adding a to the end of the number.

Outside the generally cylindrical combustor liners 12, 12a, which are components of the combustors 2, 2a, relatively cool high pressure air 100 from the compressor is indicated by the arrows in FIG. Flows from top to bottom. A high-temperature combustion gas 103 flows inside the combustor liners 12, 12a from the bottom to the top in the figure. Liner collars 19, 19a are provided in the flame propagation tube holes 18, 18a provided in the combustor liner. The flame propagation tube 15 is divided into two parts (15, 15a), and at the portion 15b, the inner diameter of the flame propagation tube 15 is made larger than the outer diameter of the flame propagation tube 15a, and is relatively movable in the axial direction. A collar stopper 2 is provided in the flame propagation tube 15.
0, and a retainer stopper 21 are provided.
2, the retainer stopper 21 is pressed to the left in the drawing.

Then, the liner collar 19 is brought into contact with the liner collar stopper 20 to position the flame propagation tube 15 with respect to the combustor liner 12. The retainer 22 receives a reaction force from the flame propagation tube 15 to the right in the figure, but the combustor outer tube 6
Fixed by. Incidentally, the retainer 22 is a generally leaf-spring-like elastic body. Therefore, even if the mutual positions of the outer cylinder 6, the retainer stopper 21, the liner collar stopper 20, and the liner collar 19 vary due to manufacturing tolerances and the like, the relative positions are absorbed within the elasticity range of the retainer 22, and the liner collar stopper 20 is removed. It can be positioned by pressing against the liner collar 19. In addition, during operation of the gas turbine, the liner collar 19, the collar stopper 20, the retainer stopper 21, and the flame propagation pipe 1 are caused by thermal deformation, vibration, or the like.
5, Even if stress occurs in the retainer 22 or the like in the axial direction of the flame propagation tube, the elasticity of the retainer allows positioning of the retainer 22 with a force that does not destroy any of them.

Similarly, the flame propagation tube 15a is provided with a collar stopper 20a and a retainer stopper 21a, and the retainer 22a is provided by the retainer 22a.
To the right of the figure. And color stopper 2
0a is brought into contact with the liner collar 19a so that the
The position of a is determined with respect to the combustor liner 12a. The retainer 22a receives a reaction force from the flame propagation tube 15a to the left in the figure, but is fixed by the combustor outer tube 6a. Then, the elasticity of the retainer 22a positions the combustor liner 12a, the liner collar 19a, the collar stopper 20a, the retainer stopper 21a, the flame propagation tube 15a, and the retainer 22a with such a force as not to break. Further, by such a positioning method, manufacturing tolerance of each component is absorbed, and stress due to thermal deformation, vibration, or the like is reduced.

Next, in order to describe a method of cooling the flame propagation tube 15, an enlarged view of the end of the flame propagation tube is shown in FIG. Here, the pressure of the combustor 2 shown in FIG.
A case where the value is higher than a will be described. Therefore, in FIG. 3, the combustion gas 1 inside the combustor liner 12 (left side in the figure)
A part 104 of 03 flows in the flame propagation tube from left to right in the figure. The terms left and right in the description refer to left and right in FIG. 3 unless otherwise specified.

The flame propagation tube 15 is provided with a cooling hole 23.
The cooling hole 23 has a double cylindrical structure as shown in FIG. 3, and the cooling air 105 flowing from the cooling hole 23 moves rightward along the axial direction of the flame propagation tube 15 near the wall surface of the flame propagation tube 15. Flows. In this way, a layer of cooling air 105 is formed between the high-temperature gas flow 104 in the flame propagation tube and the wall of the flame propagation tube, thereby suppressing heat from flowing into the flame propagation tube and protecting the flame propagation tube. Outside this portion of the flame propagation tube 15, there is a relatively low-temperature compressed air flow 100, which convectively cools the flame propagation tube from the outside and makes the internal film cooling flow 1
Along with 05, it has a function of lowering the temperature of the flame propagation tube 15. Cooling holes 24 are provided at an appropriate interval on the right side of the cooling holes 23, and the cooling air flow 106 similarly protects the flame propagation tube.

Outside of the flame propagation tube 15 in this portion, there is air 107 flowing in the connecting tube 16 due to the differential pressure between the combustors in the flow 100 of the compressed air. Cooling and internal film cooling flow 10
Along with 6, it has a function of lowering the temperature of the flame propagation tube 15. Such film cooling is generally used as a cooling method for a combustor liner or the like.
Since a cooling hole cannot be provided in a portion overlapping the liner collar 19, film cooling is difficult. Therefore, this portion is subjected to external convection cooling.

As described above, the stopper 20 for the liner collar of the flame propagation tube 15 is pressed against the liner collar 19 for positioning. Here, the left end of the flame propagation tube 15 is located outside (to the right of) the inner surface of the combustor liner 12. The inner diameter of the end (right end) of the liner collar 19 is substantially equal to the outer diameter of the left end of the flame propagation tube 15, and positions the flame propagation tube 15 in the radial direction. The inner diameter of the liner collar 19 is slightly enlarged on the left side, and maintains an appropriate distance of about 1 to 2 mm from the flame propagation tube. The liner collar 19 is provided with a cooling hole 25, from which air 107 entering the liner collar passes through an annular flow path between the liner collar 19 and the flame propagation tube 15 and is substantially parallel to the axis of the flame propagation tube. It flows into the combustor liner 12. At this time, the left end of the flame propagation tube 15 is externally cooled by the cooling air 108.

Here, as shown in FIG. 4, when the positioning accuracy between the flame propagation tube and the liner collar is poor, and when the left end of the flame propagation tube 15 is on the right side of the cooling hole 25, the cooling air 107 moves with the axis of the flame propagation tube. It flows in orthogonally and obstructs the flow of the hot gas 104 like an air curtain. In such a case, when the gas turbine is ignited, the flame propagation pipe from the already ignited can to the unignited can may become impossible. Also, as shown in FIG. 5, when the left end of the flame propagation tube 15 projects to the left from the inner wall of the combustor liner 12, the outer wall of the flame propagation tube 15 becomes in contact with the flow of the combustion gas 103 in the combustor liner 12. Because it is directly exposed, the cooling air 108 has little effect,
The flame propagation tube 15 may be rapidly destroyed.

According to the present invention, as shown in FIG. 3, the open end (left end) of the flame propagation tube is a right side of the inner wall of the combustor liner and a left side of the cooling hole of the liner collar. And effective cooling can be performed without impairing the flame propagation performance.

When assembling the flame propagation tube, first, the outer tubes 6 and 6a are attached to the gas turbine casing, and then the respective outer tubes are connected by the connecting tube 16. Next, the flame propagation tube 1
5, 15a are inserted into the connection pipe 16, and the combustor liner 2 is attached. Thereafter, the flame propagating tube 15 is inserted into the combustor liner 12 from the right side in FIG. 3, and is fixed while being pressed leftward by the retainer 22. Next, the combustor liner 12a is attached with the flame propagation tube 15a shifted to the left. Thereafter, the flame propagation tube 15a is connected to the combustor liner 12a from the left side of the figure.
And fixed while pressing it to the right by the retainer 22a. As described above, according to the structure of the present invention, the end of the flame propagation tube and the combustor liner can be positioned with a simple structure and an assembling process. At the time of disassembly, the work may be performed in the reverse order of the assembly. Since the flame propagation tube 15 is divided into two parts and is movable in the axial direction when the retainer is removed, it is easy to remove only the liner during disassembly and inspection.

FIG. 6 shows another embodiment of the present invention, in which the retainer 22 is made rigid and a part of the retainer stopper 21 is made elastic. Even with such a structure, the positioning method intended by the present invention can be performed, the manufacturing tolerance of each component can be absorbed, and the stress due to thermal deformation, vibration, or the like can be reduced. Further, as shown in FIG. 7, a portion between the retainer stopper 21 and the liner collar stopper 20 of the flame propagation tube 15 may be made of an elastic body.
FIG. 8 shows a configuration in which a cooling hole is provided in a liner collar stopper 20 instead of the cooling hole provided in the liner collar 19.

[0032]

As described above, according to the present invention, the flame propagation tube is divided into two parts in the axial direction, the flame propagation tube is provided with a stopper, the combustor liner is provided with a collar, and the flame propagation tube is provided with this collar. By pressing the stopper, the positioning between the open end of the flame propagation tube and the inner wall surface of the liner can be performed easily and accurately.

In addition, by using an elastic body as a part of the flame propagation tube or a member for pressing the stopper of the flame propagation tube against the collar of the liner, the axial stress of the flame propagation tube can be reduced.

Furthermore, the positioning according to the invention and the effective cooling method made possible thereby protect the flame propagation tube from hot combustion gases without disturbing the flame propagation tube's original purpose of propagating the flame. Therefore, the reliability of the gas turbine can be improved.

[Brief description of the drawings]

FIG. 1 is a detailed view of the vicinity of a flame propagation tube and a combustor liner in a gas turbine combustor according to one embodiment of the present invention.

FIG. 2 is a schematic diagram for explaining a gas turbine equipped with a gas turbine combustor according to one embodiment of the present invention.

FIG. 3 is an enlarged view of the vicinity of the open end of the flame propagation tube in FIG. 2;

FIG. 4 is a diagram for explaining an example of a defect when the present invention is not applied.

FIG. 5 is a diagram for explaining an example of a problem when the present invention is not applied.

FIG. 6 is a view showing another embodiment of the present invention in which a retainer stopper is an elastic body.

FIG. 7 is a diagram of another embodiment of the present invention, in which a part of the flame propagation tube is made of an elastic body.

FIG. 8 is a view showing another embodiment of the present invention in which a cooling hole is provided in a liner collar stopper.

[Explanation of symbols]

2 ... combustor, 6 ... combustor outer cylinder, 12 ... combustor liner, 1
5 ... flame propagation pipe, 16 ... connection pipe, 18 ... flame propagation pipe hole,
19: liner collar, 20: stopper for liner collar,
21 ... Retainer stopper, 22 ... Retainer, 100 ...
High-pressure air, 103: combustion gas, 104: high-temperature gas flow in the flame propagation tube.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Yoshitaka Hirata 7-2-1, Omika-cho, Hitachi City, Ibaraki Pref.

Claims (6)

[Claims] 1. A combustor comprising a liner that forms a combustion chamber and through which high-temperature combustion gas flows, and an outer cylinder that is disposed outside the liner and that forms a flow path for compressed air with the liner. In a gas turbine combustor in which a plurality of flame dispersing tubes are disposed and communicate between the liners of these adjacent combustors, the flame propagating tubes are divided into two in the axial direction,
By providing a stopper in the flame propagation tube, providing a short tubular support member in the flame propagation tube insertion port of the liner, and pressing the stopper of the flame propagation tube against the support member, the open end of the flame propagation tube and the inner wall surface of the liner A gas turbine combustor characterized by performing positioning of a gas turbine. 2. The gas turbine combustor according to claim 1, wherein a part of the flame propagation tube or a member for pressing a stopper of the flame propagation tube against the support member is an elastic body. 3. The gas turbine combustor according to claim 2, wherein the position of the open end of the flame propagation tube is determined so as to be located radially outside the liner with respect to the inner wall of the liner. 4. A cooling hole is provided in a stopper of the flame propagation tube or the support member, cooling air flows between the support member and the flame propagation tube, and a flow of the cooling air flows in an axial direction of the flame propagation tube. The gas turbine combustor according to claim 3, wherein: 5. The gas turbine combustor according to claim 4, wherein the opening end of the flame propagation tube is positioned so as to be located radially inward of the liner with respect to the cooling hole according to claim 4. 6. The gas turbine combustor according to claim 5, wherein the central portion of the flame propagation tube is cooled by film cooling.