JP2607387Y2 - Gas turbine combustor - Google Patents

Description

[Detailed description of the invention]

[0001]

The present invention relates to a two-stage combustion type having a pilot combustion region for diffusing or premixing combustion of primary fuel and a premixing combustion region for burning premixed fuel and air. An improvement of a gas turbine combustor, which relates to a gas turbine combustor having a lean diffusion combustion region after a premixed combustion region.

[0002]

2. Description of the Related Art As a conventional combustor for driving a gas turbine by supplying a combustion gas to the gas turbine, FIG.
As shown in the figure, the pilot combustion region 3 provided with the swirler 2 and the primary fuel F ₁ from the pilot burner 1 are subjected to primary combustion to maintain the flame.
The diameter D ₁ diameter D ₂ is greater premixed combustion region 4 than, i.e., by burning a mixture of pre-secondary fuel F ₂ and the air in the main combustion zone, NOx in the combustion gas G There is a diffusion / premixing type two-stage combustor whose content is reduced.

In the case of this combustor, the pilot combustion region 3
In the premixed combustion zone 4
In this case, combustion is performed at 700 to 1300 ° C., and high-temperature combustion gas G at about 1300 ° C. is supplied to a gas turbine inlet (not shown). In the case of premixed combustion, when the load on the gas turbine changes, it is necessary to adjust the concentration of the premixed gas so that the gas can be stably burned. Unless the concentration of the premixed gas is adjusted, not only misfires and oscillating combustion occur, but also the combustion efficiency is reduced and the NOx value is increased.

[0004] Furthermore, as obtaining scale reduction of NOx, as shown in FIG. 5, from about 400 to 500 ° C. while supplying primary fuel F ₁ and combustion air A as shown by arrows
A preheat-premixed combustion region 5 'to burn in, provided with catalytic combustion region 7 consisting of the catalytic combustor 6, and supplies the secondary fuel F ₂ and the combustion air A to the catalytic combustion region 7 500
There is a catalytic combustor that burns at 1300 ° C. But
The catalyst combustor has problems with the heat resistance and durability of the catalyst
Therefore, it is necessary to keep the temperature of the catalyst
You. Also, since the pressure loss of the combustor is large, the dimensions of the combustor
There is a disadvantage that the method becomes large. Therefore, the thermal deformation of the catalyst
Support the catalyst to absorb and reduce combustion gas leakage.
It is difficult to support the catalyst. Also, uniform combustion gas
Difficult to obtain temperature distribution, changes in gas turbine load
Problem that it is difficult to obtain stable low NOx combustion
There is.

[0005]

The object of the present invention is to reduce NOx in a premixed combustor over a wide range from partial load operation to rated operation, increase combustion efficiency, and improve durability. An object of the present invention is to provide a gas turbine combustor that can be improved.

[0006]

Means for Solving the Problems That is, the gas turbine combustor of the present invention, the primary fuel F ₁ pilot combustion zone (3) to diffuse or premixed combustion, and and a secondary fuel F ₂ which were pre-mixed A diffusion / premixed two-stage combustion type gas turbine combustor having a premixed combustion region (4) for burning air, wherein a stage subsequent to the premixed combustion region (4) includes:
Tertiary fuel F ₃ supplied from the tertiary fuel injection nozzle (7)
And a three-stage combustion type in which a lean diffusion combustion region (5) for lean diffusion combustion is directly added.

In the gas turbine combustor according to the present invention, the primary fuel F ₁ is provided with flame holding properties by diffusion combustion or premixed combustion, and at the same time, the secondary fuel F ₂ is enriched in a later stage of the pilot combustion region. Low NOx combustion is performed by mixed combustion. Then, when the subsequent partial load operation of the gas turbine by providing a lean diffusion combustion region downstream of the diffusion premixed combustors supplying secondary fuel F ₂ pilot combustion zone, the secondary fuel F ₂ becomes small When the combustion efficiency of the premixed combustion is reduced, the unburned portion is burned in the lean diffusion combustion region on the downstream side, and not only the combustion efficiency is increased, but also stable low NOx combustion is enabled.

[0008] The combustor according to the present invention has a low NOx in normal operation and has a flame temperature several hundred degrees lower than that of diffusion combustion. Therefore, the temperature of the inner wall of the combustor can be lowered, and the durability and reliability are improved. You can enhance the nature. Further, the pressure loss can be reduced as compared with a catalytic combustor, and the combustor can be downsized.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. In the gas turbine combustor shown in FIG. 1, an inner cylinder 11 provided inside a heat-resistant outer cylinder 10 has a primary fuel F ₁ from a pilot burner 1 in a pilot combustion region 3 provided with a swirler 2 as in the conventional case. Is subjected to flame holding for primary combustion. The secondary fuel F premixed in the premixed combustion zone 4 downstream of the pilot combustion zone 3
It is burned with ₂ and air. This secondary fuel F ₂ is 2
The fuel is supplied from the next fuel injection nozzle 6.

Further, in the present invention, the tertiary fuel F supplied from the tertiary fuel injection nozzle 7 to the downstream side of the premixed combustion zone 4 is used.
It is provided lean diffusion combustion region 5 for combusting _3. In the gas turbine combustor having the above structure performs preheating and flame holding by diffusion combustion or premix combustion in a pilot combustion region 3 for burning primary fuel F _1, holding the combustion temperature of about 350 to 500 ° C. Have been.

[0011] Next, in the premixed combustion region 4, secondary fuel F by combustion of ₂ is uniform burning of 500 to 1100 ° C. is performed, tertiary fuel in lean diffusion combustion region 5 to the combustion gas generated by this combustion by adding F ₃ it is burnt,
Generating combustion gas G at a temperature of 1100 to 1300 ° C.,
Introduced to gas turbines. As described above, in the present invention, uniform combustion is performed at a relatively low temperature by providing the premixed combustion region 4 at the end of the pilot combustion region 3, and a high-temperature combustion of 1500 ° C. or higher as in the conventional apparatus. Since no gas is generated, no high concentration NOx is generated.

The combustion gas generated at a uniform temperature from the premixed combustion zone 4 is further subjected to a combustion so as to further uniformly perform lean combustion.
By introducing the secondary fuel F ₃ , this lean diffusion region 5
, Uniform combustion is performed. As a result, 150
Since it becomes difficult to generate high-temperature combustion gas of 0 ° C. or more, NO
The generation of x also decreases. Further, even when the combustion efficiency of the secondary fuel is reduced during the partial load operation, the tertiary fuel can maintain a stable and high combustion efficiency.

FIG. 2 shows another embodiment of the present invention. The difference from the previously described embodiment is that the inner cylinder 11 is different from that of the first embodiment.
In the plurality of premixed gas forming tubes 20 connected to the shoulders of
The secondary fuel F ₂ is injected from the secondary fuel injection nozzle 21, the secondary fuel F ₂ and air are mixed in advance in the premixed gas forming pipe 20, and then supplied to the premixed combustion area 4. It is in. The other parts are the same as those of the combustor of the previous embodiment, and the description thereof is omitted.

FIG. 3 shows the relationship between the amount of generated NOx in each section of the combustor and the combustion efficiency. 2, a indicates pilot diffusion combustion, a 'indicates pilot premix combustion, b indicates premix combustion, c indicates lean diffusion combustion, and d indicates unburned combustion. FIG. 4 is a graph showing the NOx generation amount with respect to the gas turbine load (%). FIG. 4 shows the case of the embodiment (pilot diffusion combustion) of the present invention in FIG. The case of two-stage combustion is shown by B and the case of the conventional diffusion combustor is shown by C. From these diagrams, the NOx generation amount and the combustion efficiency can be obtained by employing the combustor of the present invention. Is significantly improved as the gas turbine load increases. The case where the pilot fuel is premixed and burned is represented by A '.

[0015]

[Effects of the present invention ]
A mixed two-stage combustion gas turbine combustor is a catalytic combustor.
There are many problems and problems that catalytic combustors have
There are no restrictions. It is also smaller than a catalytic combustor.
Mold and low pressure loss. Moreover, Gusta
Stable and low NO over a wide operating range
There is an excellent effect that x can be burned.

[0016]

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view of a gas turbine combustor according to another embodiment of the present invention.

FIG. 3 is a diagram showing the NOx generation amount and combustion efficiency of the gas turbine combustor according to the present invention.

FIG. 4 is a diagram showing the amount of NOx generated with respect to the gas turbine load of the gas turbine combustor of the present invention and the conventional gas turbine combustor.

FIG. 5 is a sectional view of a conventional gas turbine combustor.

FIG. 6 is a sectional view of a conventional gas turbine combustor.

[Explanation of symbols]

3 pilot combustion region 4 premixed combustion region 5 lean diffusion combustion region F ₁ 1 primary fuel F ₂ 2 primary fuel F ₃ 3 primary fuel

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Claims (1)

(57) [Scope of request for utility model registration] 1. A primary fuel F ₁ pilot combustion region to diffuse or premixed combustion (3), and the diffusion having a premixed combustion region for burning (4) and a secondary fuel F ₂ which were pre-mixed with air - a premixing type two-stage combustion type gas turbine combustor, downstream of the premixed combustion region (4), is lean diffusion combustion tertiary fuel F ₃ supplied from the tertiary fuel injection nozzles (7) Three-stage lean diffusion combustion zone (5) is directly added
A gas turbine combustor characterized by being of a combustion type .