JP3174649B2 - Gas turbine combustor - Google Patents

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 in which liquid fuel is burned inside a combustor inner cylinder, and the inner wall of the combustor inner cylinder is film-cooled by cooling air. The object is to improve such a gas turbine combustor so that the smoke level of the gas turbine exhaust is reduced.

[0002]

2. Description of the Related Art FIG. 1 is a sectional view showing an inner cylinder of a can-type or cannula-type gas turbine combustor as an example of this type of gas turbine combustor. In FIG. 1, a plurality of primary air introduction cylinders 2 are attached to the head of a combustor inner cylinder 1. The primary air 3 flowing into the combustor inner cylinder 1 from the primary air introduction cylinder 2 burns the liquid fuel 7 injected from the fuel nozzle 6 together with the air 5 flowing through the front swirler 4. , A combustion zone 8 is formed.

[0003] Further, a large number of louvers 9 are provided in the combustor inner cylinder 2, and cooling air 10 flows along the inner wall of the combustor inner cylinder 2 through these louvers 9, thereby performing film cooling. The cooling of the inner cylinder of the combustor exposed to the combustion gas is enhanced.

[0004] As the liquid fuel 7, naphtha, kerosene, light oil, jet fuel, crude oil, heavy oil, slurry oil, residual oil, methanol and the like are generally used.

[0005]

Incidentally, in the gas turbine combustor as shown in FIG. 1, when the liquid fuel is exclusively burned, the smoke level of the gas turbine exhaust gas decreases during high load operation including the rated load. There was a problem of rising.

That is, FIG. 2 is a characteristic diagram obtained by measuring the smoke level of the gas turbine exhaust gas, and shows the case where the liquid fuel is exclusively burned. In the case of the normal combustors A and B, the smoke level increases as the load increases and the fuel-air ratio increases, but after reaching a certain value, the smoke level gradually decreases, and the operation is performed at a low smoke level at the rated load. .

[0007] However, in the case of the intensified cooling of the combustor inner cylinder as shown in FIG. 1, when the amount of cooling air is increased to protect the combustor inner cylinder as the temperature of the gas turbine increases,
Smoke level does not decrease, high load (80% of rated load)
Again, the smoke level may be subject to pollution during rated operation. This seems to be due to the fact that the primary combustion air decreases due to the increase in the cooling air, and the primary combustion air tends to be short.

[0008] The smoke level is proportional to the amount of unburned carbon, and is a baccarat smoke number (Bachar).
ach Smoke Number (BSN).

SUMMARY OF THE INVENTION The present invention has been made to solve such problems of the prior art, and provides a gas turbine combustor capable of reducing the smoke level of gas turbine exhaust during high load operation including a rated load. The purpose is to do.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a method of burning liquid fuel inside a combustor inner cylinder, and cooling the inner wall of the combustor inner cylinder with cooling air. In the gas turbine combustor described above, the liquid fuel and the gas fuel are co-fired during a high load operation including a rated load.

[0011]

The gas fuel is generally cleaner than the liquid fuel, and has no smoke, no soot, no ash, no tar, and no sulfur. As shown in FIG. 3, the smoke level when the liquid fuel and the gas fuel are co-fired decreases as the ratio of the gas fuel increases. Is reduced.

Therefore, according to the above-mentioned means, during high-load operation including the rated load, in other words, before the smoke level of the gas turbine exhaust turns to decrease and then shifts to increase again, the load is matched. Since the gaseous fuel is supplied to the combustor and the liquid fuel and the gaseous fuel are co-fired, the smoke level of the gas turbine exhaust gas can be reduced.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

According to the present invention, for example, as shown in FIG. 1 described above, the liquid fuel 7 is burned inside the combustor inner cylinder 1, and the inner wall of the combustor inner cylinder 1 is film-cooled by cooling air 10. In a liquid fuel-fired high-temperature gas turbine combustor in which the cooling of the inner cylinder of the combustor is enhanced, during high load operation including a rated load, the liquid fuel and the gas fuel 11 are co-fired to reduce the smoke level of the gas turbine exhaust gas. It is like that.

FIG. 4 is a comparison characteristic diagram of the gas turbine exhaust smoke level according to the present invention and the conventional example. The solid line shows the conventional example, and the dotted line shows the case of the present invention. According to the present invention,
Prior to the fuel-air ratio A at which the smoke level shifts to an increase (the stage of 80% of the rated load) B, the liquid fuel (oil) and the gas fuel are co-fired. By increasing the fuel, the smoke level of the gas turbine exhaust is reduced.

As the gas fuel, ordinary natural gas, liquefied natural gas (LNG), liquefied petroleum gas (LPG)
Etc. can be used. Also, the co-firing start fuel-air ratio varies depending on the type of fuel, the type of combustor, and the like, and is not constant.

[0017]

As described above, according to the present invention, a gas turbine combustion system in which liquid fuel is burned inside a combustor inner cylinder and the inner wall of the combustor inner cylinder is film-cooled by cooling air. During high load operation including rated load, the smoke level of the gas turbine exhaust gas can be significantly reduced by co-firing the liquid fuel and the gas fuel, and this type of pollution problem can be solved. .

[Brief description of the drawings]

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

FIG. 2 is a characteristic diagram showing a relationship between a fuel-air ratio and a smoke level.

FIG. 3 is a characteristic diagram showing a relationship between a co-firing ratio and a smoke level.

FIG. 4 is a characteristic diagram showing a comparison between a fuel-air ratio and a smoke level in the present invention and a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Combustor inner cylinder 6 Fuel nozzle 7 Liquid fuel 9 Louver 10 Cooling air 11 Liquid fuel and gas fuel

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F02C 9/40 F23R 3/36 F02C 7/22

Claims (1)

(57) [Claims] 1. A liquid fuel is burned inside a combustor inner cylinder,
In a combustor-in-tube cooling type gas turbine combustor in which the inner wall of the combustor- inner is film-cooled by cooling air , the liquid fuel and the gas fuel are mixed in a high load operation range after a stage of 80% of the rated load. A gas turbine combustor characterized by co-firing.