JP3154550B2 - Gas turbine combustor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to gas turbine combustor capable of reducing the generation amount of NO _X.

[0002]

2. Description of the Related Art Low NO gas turbines_XAs a method,
Wet water injection, water vapor injection, and dry lean diffusion fuel
There are burning and lean premixed combustion. Use these methods for your usage
To comply with environmental regulations.
Extremely severe NO in some areas _XLevel required
Even if these methods are adopted, attach a denitration device
In many cases, this is unavoidable.

FIG. 2 is a sectional view of a conventional lean premixed combustor. The main gas fuel flowing from the elbow 1 flows into the gas reservoir 3 through the annular passage 2 and, as shown by an arrow b, from the multiple nozzles 4A and 4B provided in the circumferential direction of the gas reservoir 3. It is injected into the air flow in the double annular passages 5A and 5B. As shown by the arrow a, premixed air is sent into the double annular passages 5A and 5B by the guide vanes 6A and 6B and the swirl vanes, and the injected fuel becomes a lean premixed air and becomes a lean premixed air. Perform mixed combustion.

[0004] must lower the temperature of the flame by lean combustion in order to reduce NO _X, flame holding is difficult, is as it results in misfires. For this purpose, a pilot combustor described below is provided. That is,
The pilot gas fuel is sent from the elbow 8 to the center of the fuel nozzle 7 and is ejected from the pilot nozzle 9 provided at the tip of the fuel nozzle 7 to diffuse and burn as shown by the arrow c. Diffusion flame generated at this time has a flame holding the premixed flames, premixed combustors without misfiring, to continue the low NO _X lean combustion. The arrow d in FIG. 2 indicates the direction in which the combustion gas flows.

On the other hand, research on catalytic combustion, which is different from conventional combustion methods, has been actively conducted in recent years. It is believed extremely low NO _X combustion method of a gas turbine, NO _X
Is reduced to 10 ppm or less, and a denitration device is not required.
The ultra-lean pre-mixture of the catalyst combustion flammability limit and out, which is burned by utilizing a catalyst (Catalyzer), in which can be significantly suppressed NO _X generation amount since the flame temperature is low.

[0006]

[Problems to be solved by the invention]

1. When trying to reduce NO _x to the limit in the conventional premixed combustor, NO _x generated from a pilot combustor for flame holding becomes a problem.

[0007] 2. In conventional catalytic combustor as ultra low NO _X combustor, there is a problem in heat resistance and durability of the catalyst used, not come to be yet practical use as a gas turbine combustor.

[0008] The present invention is intended to provide a gas turbine combustor capable of reducing NO _X in view of the above circumstances.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a gas turbine combustor comprising a premixed combustor for performing lean premixed combustion and a pilot combustor for flame holding of the premixed combustor provided at a fuel nozzle. The pilot combustor has the fuel nozzle
Gas passage provided at the center of the
Start-up pilot nozzle provided and inside the gas passage
A hole is formed in the outer wall of the space between
And the gas communication with the nozzle via the catalyst fuel nozzle.
The catalyst layer provided around the tip of the road and the tip of the catalyst layer
And a nozzle provided at the end.
You .

[0010]

According to the present invention is reduced by attaching a catalyst layer for a combustion reaction accelerator to the pilot combustor, it is possible to lean combustion of the pilot combustor, NO _X amount generated down the temperature of the flame is to the limit Is done.

Further, since the catalyst layer is provided in the pilot combustor, the amount of fuel passing through the catalyst layer is small,
Therefore, the catalyst layer becomes smaller, the catalyst strength is increased, and the durability of the catalyst is improved in combination with lowering the combustion temperature and improving the heat resistance of the catalyst.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIG. FIG. 1 is a sectional view of a gas turbine combustor according to the present embodiment.

In this embodiment, an elbow 1 to which the main gas fuel is supplied, an annular passage 2 connected to the elbow 1, a gas reservoir 3, a large number of nozzles 4A and 4B, a double annular passage 5A and 5B, The guide vanes 6A and 6B are the same as the conventional lean premix combustor shown in FIG. 2, and the description thereof will be omitted.

Reference numeral 8 denotes an elbow to which pilot gas fuel is supplied. The elbow 8 communicates with an annular gas passage 10 provided at the center of the fuel nozzle 7. A starting pilot nozzle 18 is provided at the tip of the annular gas passage 10, and a hole 11 is provided in an outer wall at an intermediate portion thereof. The annular gas passage 10 is connected to the air passage 13 via the hole 11 and a catalyst fuel nozzle 12 communicating with the hole 11, and the air passage 13 is connected to the annular gas passage 1.
It is open to a chamber 14 provided around 0. Room 1
Reference numeral 4 denotes a bell mouth 15 which is connected to a catalyst layer 16 provided around the tip of the annular gas passage 10, and a nozzle 17 is provided at the tip of the catalyst layer 16.

As the catalyst constituting the catalyst layer 16, for example, a palladium-based catalyst is used, and as its base material, cordierite or the like is used.

In this embodiment, the pilot gas fuel flows into the annular gas passage 10 from the elbow 8 as shown by an arrow e, and flows from the hole 11 and the catalyst fuel nozzle 12 through the air passage as shown by an arrow f. 13 to form a fuel-air mixture. This fuel / air mixture is rectified by the bell mouth 15 from the chamber 14 and flows into the catalyst layer 16. The bell mouth 15 makes the exit speed on the catalyst surface uniform and forms a film layer on the outer periphery to prevent flashback from the catalyst layer.

The combustible fuel / air mixture is supplied to the catalyst layer 1
Then, the fuel is ignited and burned behind the catalyst, and the flame is ejected from the nozzle 17 as shown by the arrow g, and the main gas fuel injected from the double annular passages 5A and 5B and the air are used for combustion. Hold the mixed flame.

As described above, in this embodiment, the catalyst layer 16
By burning the premixed air of the pilot gas fuel and the air, the premixed flame of the main gas fuel and the air injected from the double annular passages 5A and 5B can be maintained. Moreover, the pilot gas fuel is the catalyst layer 16
To perform lean combustion,
It is possible to reduce the amount of NO _X generated by lowering the temperature of the flame to the utmost.

Further, since the amount of fuel passing through the catalyst layer 16 is small, the catalyst layer can be made smaller and the catalyst strength can be improved, and the combustion temperature can be lowered as described above. Performance can be improved.

[0020]

According to the present invention, combustion of the pilot combustor for premixed combustors premixed combustor flame holding performing lean premixed combustion
In the gas turbine combustor provided in the fuel nozzle , the pilot combustor is provided in the center of the fuel nozzle.
Gas passage and a start-up pad provided at the tip of the gas passage.
Holes in the outer wall of the middle part of the gas passage with the Ilot nozzle
A fuel nozzle for the catalyst that is provided and communicates with the hole;
Around the tip of the gas passage through a gas nozzle.
The catalyst layer provided and the nozzle provided at the tip of the catalyst layer
Since the advantages of the premixed combustor and the catalytic combustion are combined, the generation of NO _x can be suppressed (can be reduced to 10 ppm or less), and the extremely low NO _x gas turbine combustor is provided. Can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a gas turbine combustor according to one embodiment of the present invention.

FIG. 2 is a cross-sectional view of a conventional premixed combustor of a gas turbine.

[Explanation of symbols]

 Reference Signs List 7 fuel nozzle 8 elbow 10 annular gas passage 12 fuel nozzle 13 air passage 14 chamber 15 bellmouth 16 catalyst layer 17 nozzle

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Japanese Utility Model Showa Sho 62-81865 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F23R 3/40

Claims (1)

(57) [Claims] 1. A premixed combustor for performing lean premixed combustion and a pilot combustor for flame holding of the premixed combustor are provided in a fuel nozzle.
In the gas turbine combustor provided, the pilot combustor includes a gas provided at a central portion of the fuel nozzle.
Passage and a start-up pilot provided at the end of the gas passage.
Holes in the outer wall of the gas nozzle and the middle part of the gas passage
A catalyst fuel nozzle communicating with the hole, and a catalyst fuel nozzle
Around the distal end of the gas passage.
Between the catalyst layer and the nozzle provided at the tip of the catalyst layer.
A gas turbine combustor characterized by being provided .