JPH066952U - Gas turbine combustor - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the amount of NO _x produced in a gas turbine combustor in which a main combustor for lean premixed combustion and a pilot combustor for diffusion combustion are combined. [Configuration] The flame zone of the pilot combustor (12), by lowering the flame temperature by injecting steam or water from the nozzle (16), inhibits the NO _x generation. Main combustor (1
In the case of 1), since the lean premixed combustion is performed, the amount of NO _x generated is originally small. Since only the pilot combustor (12) injects steam or water, the decrease in gas turbine efficiency due to the injection is negligible.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

This invention relates to a fuel nozzle structure of the gas turbine combustor, in particular low-NO _x premix combustors.

[0002]

[Prior art]

One technique for reducing NO _x in the exhaust gas of the gas turbine there is a lean premixed combustion. FIG. 2 is an assembled sectional view showing an example of a conventional gas turbine premix combustor. The main gas fuel flowing in from the elbow (1) flows into the gas reservoir (3) through the passage (2) having an annular cross section, and from the multiple nozzles (4A) and (4B) provided in the circumferential direction. It is injected into the air stream. On the other hand, the air for premixing is sent to the passages (5A) and (5B) of the double annular section through the guide vanes (6A) and (6B) and the swirl vanes (7A) and (7B). The fuel is mixed with the injected fuel to form a lean premixed gas, and a lean premixed combustion is performed.

According to such lean combustion, the temperature of the flame is lowered, so the amount of NO _x produced is reduced, but on the other hand, it becomes difficult to hold the flame for continuing the combustion, and if it is left as it is, a misfire will occur. Then, the pilot gas fuel is sent from the elbow (9) to the center of the fuel nozzle (8) and ejected from the pilot nozzle (10) provided at the tip of the fuel nozzle (8) to perform diffuse combustion with an appropriate air-fuel ratio. Since diffusion flame generated at this time is flame holding said premixed flame, premixed combustors continues to lean burn low NO _x without misfire.

[0004]

[Problems to be solved by the device]

In recent years, the NO _x limit value has become stricter due to environmental regulations, and an extremely low NO _x gas turbine of 50 ppm or less has become necessary for domestic use. For Oite the conventional gas turbine combustor, but NO _x is little generated from premixed combustors themselves to lean combustion, NO _x often occurs in the pilot combustor for flame holding for diffusion combustion, the environmental criteria There was a case that could not be satisfied.

[0005]

[Means for Solving the Problems]

 In order to solve the above-mentioned conventional problems, the present invention is directed to a gas turbine combustor having a flame-preserving pilot combustor that performs diffusion combustion, and a lean premixed combustion. A gas turbine combustor characterized by having means for injecting steam or water into the region is proposed.

[0006]

[Action]

According to the present invention, the following effects occur. 1) Since the flame of the pilot combustor and the temperature in the primary combustion region, which had been a problem with the generation of NO _{x in the} past, are lowered, NO _x from this pilot combustor is also reduced. 2) Since no steam or water is injected into the premixed combustor itself, the total injection amount is extremely small, and therefore there is almost no reduction in the gas turbine thermal efficiency associated with the injection.

[0007]

【Example】

 FIG. 1 is an assembled sectional view showing an embodiment of the present invention. In this figure, the same parts as those of the conventional one described with reference to FIG. 2 are designated by the same reference numerals to avoid redundancy, and detailed description thereof is omitted.

In this embodiment, the elbow (13), the passage (14), and the pool (14) are introduced into the flame region of the pilot combustor (12) that performs diffusion combustion for flame holding of the lean premixed combustor (11). Water vapor or water is injected through 15) and the nozzle (16).

In this embodiment, since steam or water is injected into the flame area of the pilot combustor (12), the temperature of the flame and the primary combustion area in this area is lowered, and therefore the amount of NO _x produced is also reduced. According to the experiment, only 5% of the fuel amount of the steam was added, and the NO _x concentration was reduced to 76% of the value without addition.

Since the premixed combustor (11) does not inject steam or water, the injection amount as a whole is as small as about 1/10 of the conventional injection amount. That is, in the conventional diffusion combustor, steam of about 100% of the fuel amount was supplied, whereas in the present embodiment, only 5 to 10% of the fuel is supplied. Therefore, there is almost no reduction in the thermal efficiency of the gas turbine due to the injection.

[0011]

[Effect of device]

According to the present invention, it is possible to obtain a gas turbine combustor with an extremely low NO _x , in which NO _x generated in the pilot flame portion that performs diffusion combustion is reduced and NO _x generated in the entire premix combustor is 50 ppm or less. Moreover, there is almost no decrease in thermal efficiency due to the injection of water vapor or water.

[Brief description of drawings]

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

FIG. 2 is an assembled sectional view showing an example of a premixed combustor of a conventional gas turbine.

[Explanation of symbols]

 (4A), (4B) Main gas fuel nozzle (6A), (6B) Guide vanes (7A), (7B) Swirl vane (10) Pilot nozzle (11) Premix combustor (12) Pilot combustor (16) Water vapor or water injection nozzle

Continued Front Page (72) Satoshi Tanimura Satoshi Tanimura 2-1-1, Niihama, Arai-cho, Takasago-shi, Hyogo Mitsubishi Heavy Industries Ltd. Takasago Laboratory

Claims (1)

[Scope of utility model registration request] 1. A gas turbine combustor having a pilot flame combustor for diffusion combustion and for lean premix combustion, comprising means for injecting steam or water into the flame region of the pilot combustor. A gas turbine combustor characterized by the above.