Gas turbine combustor

Abstract

A gas turbine combustor includes a first air flow path through which air flows out into a combustion chamber, and a fuel flow path through which fuel flows out into the air flowing out of the first air flow path, in which the first air flow path is configured such that the air flowing out of the first air flow path expands toward an inside of the combustion chamber, and a second air flow path through which air flows out from a vertical direction into the air flowing out of the first air flow path is provided.

Description

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to Japanese Patent Application No. 2025-008271 filed on Jan. 21, 2025. The disclosure of the above-identified application, including the specification, drawings, and claims, is incorporated by reference herein in its entirety.BACKGROUND1. Technical Field

[0002] The present disclosure relates to a gas turbine combustor.2. Description of Related Art

[0003] Japanese Unexamined Patent Application Publication No. 2020-106258 (JP 2020-106258 A) discloses a combustion device that achieves low-NOx combustion and suppression of flame flashback by using an annular fuel injection unit including an annular fuel injection member and an annular air guide member.SUMMARY

[0004] This structure is complicated and is not suitable for a small gas turbine. In addition, since mixing of hydrogen and air is not sufficient, there is a problem with low-NOx fuel. Although there is also a method of adopting a vertical mixing type nozzle as a structure suitable for the small gas turbine, a problem with ignitability may arise as a result of improvement in the mixing of the hydrogen and the air.

[0005] Therefore, an object of the present disclosure is to provide a gas turbine combustor capable of improving ignitability and reducing NOx.

[0006] A gas turbine combustor according to the present disclosure is a gas turbine combustor including:a first air flow path through which air flows out into a combustion chamber; anda fuel flow path through which fuel flows out into the air flowing out of the first air flow path, in whichthe first air flow path is configured such that the air flowing out of the first air flow path expands toward an inside of the combustion chamber, anda second air flow path through which air flows out from a vertical direction into the air flowing out of the first air flow path is provided.

[0007] The gas turbine combustor according to the present disclosure may be configured such that the fuel flows out between the air flowing out of the first air flow path and the air flowing out of the second air flow path.

[0008] According to the present disclosure, an air-fuel mixture is formed in a flared shape, and the ignitability can be improved by an igniter present in an outer peripheral portion of the combustion chamber. In addition, it is possible to achieve both flared-shaped flow and suppression of erosion by vertical mixing. In addition, as a result, a temperature in the combustor can be maintained lower than that in the related art, and a further effect of reducing NOx can be obtained.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Features, advantages, and technical and industrial significance of exemplary embodiments of the disclosure will be described below with reference to the accompanying drawings, in which like signs denote like elements, and wherein:

[0010] FIG. 1 is a perspective view showing a structure of a gas turbine combustor 10;

[0011] FIG. 2 is a cross-sectional view showing the structure of the gas turbine combustor 10;

[0012] FIG. 3 is a perspective view of a fuel injection nozzle 20; and

[0013] FIG. 4 is a cross-sectional view of the fuel injection nozzle 20.DETAILED DESCRIPTION OF EMBODIMENTS1. Structure of Gas Turbine Combustor

[0014] The gas turbine combustor according to the present disclosure can be used for a gas turbine combustor that uses a substance having a lower mass and a higher combustion temperature than hydrogen or a hydrocarbon-based substance used in the related art as fuel. FIG. 1 is a perspective view (in which only some members are shown for description) showing the gas turbine combustor 10, FIG. 2 is a cross-sectional view showing a periphery of one fuel injection nozzle 20 in the gas turbine combustor 10, FIG. 3 is an external perspective view of the fuel injection nozzle 20, and FIG. 4 is a cross-sectional view showing an internal structure of the fuel injection nozzle 20.

[0015] As shown in FIGS. 1 and 2, in the gas turbine combustor 10, the fuel injection nozzle 20 includes a double tubular housing 31 having an axis O as an axis. A combustion chamber 30 that defines a combustion field A is provided inside the housing 31. An opening 31a is provided in a bottom surface of the housing 31 in the combustion chamber 30, and the fuel injection nozzle 20 is installed here.In addition, a circular pipe-shaped compressed air supply pipe 40 is provided on an outer periphery of the housing 31 to surround the housing 31, and a flow path 40a through which compressed air PA flows is provided between the housing 31 and the compressed air supply pipe 40. The compressed air PA flows into the fuel injection nozzle 20 from a compressor (not shown) connected to a turbine (not shown) through a first air flow path 40b in communication with the flow path 40a. In addition, the fuel F flows into from a fuel tank (not shown) through a fuel supply pipe 21, and the compressed air PA from the first air flow path 40b and the fuel F are mixed and released to the combustion field A as indicated by an arrow M to be combusted. The flow of air or fuel will be described in detail later.

[0016] Further, as shown in FIG. 2, a second air flow path 32 is provided on a side surface of the double circular pipe-shaped housing 31. The second air flow path 32 communicates with the flow path 40a and the combustion field A, and a part of the compressed air PA flowing through the flow path 40a is configured to flow out into the combustion field A.

[0017] As shown in FIG. 1, a plurality of the fuel injection nozzles 20 are arranged to revolve at predetermined intervals along a bottom portion of the housing 31, and an air-fuel mixture flows out from each of the fuel injection nozzles 20 toward the combustion field A. An outflow state of the air-fuel mixture will be described in detail later.

[0018] In addition, as shown in FIGS. 1 and 2, an igniter 50 that is an igniter is disposed on an outer peripheral portion of the housing 31, and is configured to ignite the air-fuel mixture that has flowed out into the combustion field A to generate a flame. The igniter 50 is provided at a position between the fuel injection nozzle 20 and the second air flow path 32 in the direction of the axis O.

[0019] As shown in FIGS. 3 and 4, each of the fuel injection nozzles 20 includes a substantially cylindrical peripheral wall portion 23 on which a flange 22 and the like are provided. Each of the fuel injection nozzles 20 is fitted to the opening 31a of the housing 31 such that an end surface on which the nozzle port 20a is open faces the combustion field A. In the fuel injection nozzle 20, a first air outflow port 20b from the first air flow path 40b is open in a substantially central region of the bottom portion on a side opposite to the nozzle port 20a. In addition, a plurality of fuel injection ports 20d are disposed substantially uniformly along the inner periphery on an inner peripheral surface of the fuel injection nozzle 20. The fuel injection port 20d is an outflow port of a fuel flow path 21a from the fuel supply pipe 21. The fuel injection port 20d is disposed on a nozzle port 20a side with respect to the first air outflow port 20b.

[0020] The first air outflow port 20b, the fuel injection port 20d, and the opening of the second air flow path 32 on the combustion field A side may be disposed concentrically in this order and may be configured to more uniformly inject the compressed air and the fuel.2. Outflow of Air and Fuel

[0021] In the gas turbine combustor 10 described above, air or fuel flows out as follows.

[0022] The air that has flowed out from the flow path 40a through the first air flow path 40b and the first air outflow port 20b flows out toward the nozzle port 20a. In this case, the air flows out to be expanded in a flared shape as the air moves away from the first air outflow port 20b as indicated by an arrow E in FIG. 4. A specific aspect thereof is not particularly limited, but an aspect in which the first air flow path 40b is inclined at an angle that is flared with respect to an axis Q of the fuel injection nozzle 20 in at least the vicinity of the first air outflow port 20b is exemplified.

[0023] The fuel distributed to each of the fuel flow paths 21a from the fuel supply pipe 21 reaches the fuel injection port 20d and is injected toward the inside of the fuel injection nozzle 20 (toward the axis Q) as indicated by an arrow F in FIG. 4.Therefore, in the fuel injection nozzle 20, as indicated by the arrow M in FIG. 2, the air that has flowed out of the first air outflow port 20b flows out into the combustion field A with the fuel that has flowed out of the fuel injection port 20d in an air-fuel mixture. In this case, the flow indicated by the arrow M also flows out to be flared with respect to the axis Q of the fuel injection nozzle 20 by the air that has flowed out of the first air flow path 40b in a flared manner.

[0024] The air flows out from the flow path 40a through the second air flow path 32 and the opening of the second air flow path 32 toward the combustion field A. The air at this time flows out to be in a vertical direction with respect to the axis Q (air that has flowed out of the first air flow path) of the fuel injection nozzle 20 as indicated by an arrow N in FIG. 2.3. Effects and Like

[0025] By allowing the air to flow out of the first air flow path in a flared shape, the air-fuel mixture is also flared in the combustion field A, and can approach the igniter 50, whereby ignitability can be improved.In addition, since the flows of the air that has flowed out of the second air flow path and the air that has flowed out of the first air flow path are substantially perpendicular to each other, the fuel is interposed between the two air flows, and the air and the fuel can be efficiently mixed. As a result, the fuel and the air are mixed to form a lean mixture, and the effect of reducing NOx can be obtained. In addition, since the combustion is diluted combustion, the temperature is low, and the temperature of the combustion gas that returns to the inside of the fuel injection nozzle 20 is also low, such that erosion can be prevented.

Claims

1. A gas turbine combustor comprising:a first air flow path through which air flows out into a combustion chamber; anda fuel flow path through which fuel flows out into the air flowing out of the first air flow path, wherein:the first air flow path is configured such that the air flowing out of the first air flow path expands toward an inside of the combustion chamber; anda second air flow path through which air flows out from a vertical direction into the air flowing out of the first air flow path is provided.

2. The gas turbine combustor according to claim 1, wherein the fuel flows out between the air flowing out of the first air flow path and the air flowing out of the second air flow path.

Images