JP2002089841A - Combustion device for gas turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustion device for a gas turbine in which the size of a catalytic combustion device for burning exhaust gas of an anode for the gas turbine can be extremely reduced and a stable combustion can be achieved in a simple structure. SOLUTION: The combustion device for the gas turbine comprises a cathode exhaust gas line 22 for supplying cathode exhaust gas 7c including oxygen to a gas turbine power generator 16, the catalytic combustion device 25a for burning the low calorie exhaust gas 4a of the anode by compressed air 26b to supply combustion exhaust gas 11a to the cathode exhaust gas line and a burner combustion device 25b for burning high calorie fuel gas 1a by compressed air 26a to supply combustion exhaust gas 11b to the cathode exhaust line.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a gas turbine combustor for burning anode exhaust gas.

[0002]

2. Description of the Related Art Molten carbonate fuel cells have features that are not found in conventional power generation devices, such as high efficiency and little impact on the environment, and have attracted attention as power generation systems following hydro, thermal and nuclear power. Are being researched and developed in various countries around the world. In particular, in a power generation facility using a molten carbonate fuel cell using natural gas as a fuel, as shown in FIG. 2, a reformer 10 for reforming a fuel gas 1 such as natural gas into an anode gas 2 containing hydrogen is provided. And a fuel cell 12 for generating electricity from the anode gas 2 and the cathode gas 3 containing oxygen. The anode gas 2 produced in the reformer 10 is
2 in the fuel cell (for example, 80%).
%), The combustor 1 as anode exhaust gas 4
1,15.

In the combustor 11, combustible components (hydrogen, carbon monoxide, methane, etc.) in the anode exhaust gas are burned, and the heating chamber of the reformer 10 is heated by the high-temperature combustion gas to reform the fuel passing through the reforming chamber. To qualify. The combustion exhaust gas 5 that has exited the reforming chamber is circulated and supplied to the cathode side of the fuel cell 12 by the cathode blower 14 and merges with the pressurized air 6 supplied from the gas turbine generator 16 to form the cathode gas 3, Supply the necessary oxygen and carbon dioxide to the cathode side of. The cathode gas (cathode exhaust gas 7) partially reacted in the fuel cell is circulated to a portion 7b upstream of the fuel cell 12 via a circulation control valve 14a, and a portion 7a is
1 is supplied. The remaining cathode exhaust gas 7c is the combustor 1
At 5, a part 4 a of the anode exhaust gas 4 is burned, the pressure is recovered by the gas turbine generator 16, and the heat is recovered by the exhaust heat recovery steam generator 18 and discharged out of the system. In this figure, 8 is steam, 9 is cooling water, 13 is a fuel preheater, and 17 is a feed water pump.

[0004]

FIG. 3 is a detailed block diagram of the part A in FIG. In this figure, the combustor 15 of FIG.
Consists of a catalytic combustor 15a for burning the anode exhaust gas 4a and a burner combustor 15b for burning the fuel gas 1 (natural gas or the like). That is, as a combustor of a gas turbine combustor, a burner combustor 15b for burning high calorie gas such as natural gas and city gas.
In addition, a catalytic combustor 15a for burning low-calorie gas such as anode exhaust gas is required.

[0005] In this case, the anode exhaust gas 4a and the cathode exhaust gas 7c are supplied to the catalytic combustor 15a after being mixed in the mixer 15c (mixer). Is high, the superficial velocity (SV value:
There is a problem in that the catalyst combustor 15a is much larger than the burner combustor 15b in order to keep the space velocity within an allowable range. Specifically, for example,
The size of the reaction part of the catalytic combustor 15a is 620 mm in diameter.
It is about 760 mm.

Further, an exhaust heat recovery steam generator 18 (HRS)
G: Heat RecoverySteam Gene
If the temperature of the exhaust gas to be supplied to the exhaust gas is low, the required amount of steam becomes insufficient, so that it is necessary to increase the temperature of the exhaust gas by adding additional fuel gas 1a in the combustor 15. In this case, since the burner combustor 15b is used for startup and independent operation and has a small amount of combustion, it is necessary to inject the fuel gas 1a into the catalytic combustor 15a to perform catalytic combustion during additional cooking. Was. However, if the high calorie gas is supplied to the catalytic combustor as it is, there is a risk of local overheating, so it is necessary to supply the gas uniformly to the combustion catalyst. For this reason, there has been a problem that the combustion injection structure is complicated, the development elements are large and the cost is high.

The present invention has been made to solve the above problems. That is, an object of the present invention is to provide a gas turbine combustor that can significantly reduce the size of a catalytic combustor that burns anode exhaust gas for a gas turbine and that can perform stable combustion with a simple structure.

[0008]

According to the present invention, a cathode exhaust gas (7c) containing oxygen is supplied to a gas turbine generator (1).
6) and a low calorie anode exhaust gas (4a) supplied to the cathode exhaust gas line (22) and compressed air (26b).
And a catalytic combustor (25a) for supplying the combustion exhaust gas (11a) to the cathode exhaust gas line, and burning the high calorie fuel gas (1a) with the compressed air (26a) to produce the combustion exhaust gas (11b) as the cathode exhaust gas. A gas turbine combustor comprising a burner combustor (25b) for supplying to a line.

According to the configuration of the present invention, the low calorie anode exhaust gas (4a) is burned in the catalytic combustor (25a) by the compressed air (26b) from the gas turbine. (7c) is not supplied into the catalytic combustor (25a). Therefore, even if the amount of gas passing through the catalytic combustor is small and the catalytic combustor is significantly reduced in size, the superficial velocity (SV value: Space Verocci)
ty) can be kept within an allowable range. Further, since the high calorie fuel gas (1a) is not supplied to the catalytic combustor (25a), a complicated combustion injection structure for uniformly supplying the high calorie gas is not required. Further, since the burner combustor (25b) burns the high calorie fuel gas (1a) with the compressed air (26a), the temperature of the exhaust gas supplied to the exhaust heat recovery steam generator 18 increases. If additional cooking is required, the fuel gas 1a is burned by a burner combustor and the combustion exhaust gas (11b)
Can be supplied to the gas turbine via the cathode exhaust gas line (22).

According to a preferred embodiment of the present invention, a mixer (27) for mixing the anode exhaust gas (4a) and the compressed air (26b) is provided. Such a mixer (2
7), the mixing of the anode exhaust gas (4a) and the compressed air (26b) is promoted, and the catalytic combustor (25
The combustion in a) can be further stabilized.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. In the drawings, common parts are denoted by the same reference numerals. FIG. 1 is a configuration diagram of a gas turbine combustor of the present invention. As shown in this figure, the gas turbine combustor 20 of the present invention includes a cathode exhaust gas line 22, a catalytic combustor 25a, a burner combustor 25b, and a mixer 27.

The cathode exhaust gas line 22 is connected to the combustion cell 1
Cathode exhaust gas 7c containing oxygen leaving cathode side C of No. 2
To the turbine T of the gas turbine generator 16 in the catalytic combustor 2
Supply without passing through 5a. This pipe line has a relatively large diameter because the cathode exhaust gas 7c has a large flow rate, and requires, for example, a pipe of 400a.

A low calorie anode exhaust gas 4a exiting the anode side A of the combustion cell 12 is provided in the catalytic combustor 25a.
The compressed air 26b compressed by the gas turbine generator 16 is supplied, and the low calorie anode exhaust gas 4a is internally burned by the compressed air 26b. This catalytic combustor 25a
Since the anode exhaust gas 4a is not a cathode exhaust gas having a small flow rate and a low oxygen concentration but is burned by the compressed air 26b, stable combustion can be easily performed. In addition, the amount of gas passing through the catalytic combustor is small, and the superficial velocity can be kept within an allowable range even if the catalytic combustor is significantly reduced in size. For example, under the same conditions as before, the catalytic combustor 2
The inner dimension of 5a is 200 mm x 340 mm in diameter, which is about 1/20 before the improvement, and can be made much more compact. Further, the combustion exhaust gas 11a after being burned in the catalytic combustor 25a is supplied to the cathode exhaust gas line 22, merges with the cathode exhaust gas 7c, and is supplied to the turbine T of the gas turbine generator 16.

The mixer 27 promotes the mixing of the anode exhaust gas 4a and the compressed air 26b, and further stabilizes the combustion in the catalytic combustor 25a.
It is installed on the upstream side of a.

The burner combustor 25b is supplied with a high-calorie fuel gas 1a and compressed air 26b compressed by the gas turbine generator 16, and burns the high-calorie fuel gas 1a with the compressed air 26a to produce combustion exhaust gas. 11b is supplied to the cathode exhaust gas line 22. The burner combustor 25b is configured to have a larger combustion amount than the conventional burner combustor 25b so that the burner combustor 25b can be used for start-up / single operation and also for additional cooking for raising the exhaust gas temperature. Also in this case, the burner combustor 25b can be made almost the same size as the conventional one because the high calorie fuel gas 1a is burned.

The above-described gas turbine combustor 20 operates as follows. Since the catalytic combustor 25a is miniaturized, a general-purpose product can be used. The burner combustor 25b is used at the time of starting the gas turbine, at the time of partial load, and at the time of generating excess steam, and burns the natural gas 1a with the air 26a. The catalyst combustor 25a and the burner combustor 25b are used alone or simultaneously. Compressed air 6 from gas turbine 16
Is supplied to the fuel cell, and the exhaust gas from the fuel cell returns to the gas turbine as the anode exhaust gas 4a and the cathode exhaust gas 7c, respectively. At this time, the anode exhaust gas 4a
Contains combustible gas and is combusted by the catalytic combustor 25a. The burner combustor 25b burns the natural gas 1a with compressed air 26a from a gas turbine. The combustion exhaust gas that has passed through the gas turbine is supplied to an HRSG (exhaust heat recovery boiler) and discharged outside the system.

As described above, in the gas turbine combustor 20 of the present invention, the anode exhaust gas 4a is combusted by the air 6 from the gas turbine, so that the catalytic combustor 25a
Is about 1/20 of the size before improvement,
It can contribute to cost reduction. Further, since the natural gas 1a is burned only by the burner combustor 25b, it is not necessary to install a dedicated fuel injection device.

It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

[0019]

As described above, according to the structure of the present invention, the low calorie anode exhaust gas 4a is burned in the catalytic combustor 25a by the compressed air 26b from the gas turbine. 7c is not supplied into the catalytic combustor 25a. Therefore, even if the amount of gas passing through the catalytic combustor is small and the catalytic combustor is significantly reduced in size, the superficial velocity (SV value: Space Verocit) is increased.
y) can be kept within an allowable range.

Further, since the high calorie fuel gas 1a is not supplied to the catalytic combustor 25a, a complicated combustion injection structure for uniformly supplying the high calorie gas is not required. Further, since the burner combustor 25b burns the high-calorie fuel gas 1a with the compressed air 26a, additional cooking is necessary to increase the temperature of the exhaust gas supplied to the exhaust heat recovery steam generator 18. In this case, the fuel gas 1a can be burned by a burner combustor, and the combustion exhaust gas 11b can be supplied to the gas turbine via the cathode exhaust gas line 22.

Therefore, the gas turbine combustor according to the present invention is excellent in that the catalytic combustor for burning the anode exhaust gas for the gas turbine can be significantly reduced in size and can be stably burned with a simple structure. Has an effect.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a gas turbine combustor of the present invention.

FIG. 2 is an overall configuration diagram of a conventional power generation facility using a molten carbonate fuel cell.

FIG. 3 is a configuration diagram of a conventional gas turbine combustor.

[Explanation of symbols]

1, 1a fuel gas, 2 anode gas, 3 cathode gas, 4 anode exhaust gas, 5 combustion exhaust gas, 6, 6
a, 6b air, 7, 7a, 7b, 7c cathode exhaust gas, 8 steam, 9 cooling water, 10 reformer, 11a, 1
1b Combustion exhaust gas, 12 fuel cell, 13 fuel preheater, 14 cathode blower, 15 gas turbine combustor, 15a catalytic combustor, 15b burner combustor, 16
Gas turbine generator, 17 feed water pump, 18 waste heat recovery steam generator, 22 cathode exhaust gas line, 25
a catalytic burner, 25b burner burner, 26a, 26
b Compressed air, 27 mixer

Claims (2)

[Claims] 1. A cathode exhaust gas line (22) for supplying a cathode exhaust gas (7c) containing oxygen to a gas turbine generator (16), and a low calorie anode exhaust gas (4a).
Is burned with compressed air (26b) and the combustion exhaust gas (11
a) is supplied to the cathode exhaust gas line.
5a) and a burner combustor (25b) for burning high calorie fuel gas (1a) with compressed air (26a) and supplying the combustion exhaust gas (11b) to a cathode exhaust gas line. Turbine combustor. 2. The gas turbine combustor according to claim 1, further comprising a mixer (27) for mixing the anode exhaust gas (4a) and the compressed air (26b).