WO2016088612A1 - Gas turbine combustor and gas turbine - Google Patents

Abstract

Provided are a gas turbine combustor and a gas turbine, with which the amount of NOx exhaust emissions from a diffuse combustion-type duct burner can be reduced. A duct burner 36 is provided with cylindrical fuel injection nozzles 38 and air holes 340. The fuel injection nozzles 38 are supported by an outside casing 35 along eight axial centers 360 included within a plane orthogonal to a center axis 302 and arranged at equidistant intervals (45-degree intervals) in the circumferential direction. Sets of eight fuel injection nozzles 38a-1 to 38a-8, 38b-1 to 38b-8, 38c-1 to 38c-8, 38d-1 to 38d-8 are respectively constituted as single fuel injection nozzle rows, the four fuel injection nozzle rows 38a, 38b, 38c, 38d being arrayed at prescribed spacing along the direction of the center axis 302. The angular positions of the fuel injection nozzles 38a-1 to 38a-8, 38b-1 to 38b-8, 38c-1 to 38c-8, 38d-1 to 38d-8 are arrayed so as to be shifted by the half-pitch angle in opposing rows.

Description

Gas turbine combustor and gas turbine

The present invention relates to a gas turbine combustor and a gas turbine.

In gas turbines, strict environmental standards are established for nitrogen oxides (hereinafter referred to as “NOx”) contained in turbine exhaust gas.

The applicant has a plurality of premixed combustion type main burners arranged on the upstream side (first combustion region) of the combustion chamber and the combustion chamber in the combustion chamber on the downstream side (second combustion region) of the combustion chamber. A gas turbine combustor having a diffusion combustion type reheating burner arranged so as to face a dilution air hole through which air is introduced has been proposed (for example, see Patent Document 1).

JP-A-8-210642

The gas turbine combustor described in Patent Document 1 employs a diffusion combustion type reheating burner and has an advantage of low risk of flashback. However, when the fuel flow rate of the additional burner is increased, the fuel concentration in the combustion region of the additional burner increases and the combustion temperature rises, resulting in a problem that the NOx emission amount increases.

Accordingly, an object of the present invention is to reduce the NOx emission amount from the diffusion burner reheating burner in the gas turbine combustor and the gas turbine having the above-described configuration.

A combustor for a gas turbine according to the present invention is a combustor for a gas turbine in which fuel is mixed with combusted air introduced from a compressor and burned, and the generated combustion exhaust gas is supplied to the gas turbine. A premixed combustion type main burner disposed on the upstream side of the combustion tube, and disposed on the downstream side of the main burner through the peripheral wall of the combustion tube and from the peripheral wall to the combustion chamber And a plurality of diffusion combustion type burner burners that inject fuel into the combustion cylinder, and the plurality of burner burners are arranged in alignment in the circumferential direction and the axial direction of the combustion cylinder.

According to this configuration, since the main burner is a premixed combustion method, the amount of NOx in the high-temperature combustion gas generated in the primary combustion region upstream of the combustion chamber is suppressed. In addition, the plurality of additional burners are arranged in alignment in the circumferential direction and the axial direction of the combustion cylinder, and the additional fuel is distributed and supplied from each additional burner to the combustion chamber. The fuel flow rate per additional burner is smaller than when the burners are arranged in the circumferential direction. Therefore, the fuel concentration in the combustion region of each additional burner is reduced, and the combustion temperature of each additional burner is reduced overall, so that the amount of NOx in the combustion gas can be suppressed.

The plurality of tracking burners arranged in adjacent rows may be staggered in the circumferential direction.

According to this configuration, the combustion of the additional burner arranged on the downstream side is less affected by the combustion of the additional burner arranged on the upstream side by arranging the additional burners in the circumferential direction in a staggered manner. Combustion of the side burner can be stabilized.

A fuel header that distributes the fuel to each of the plurality of additional burners may be provided.

こ の According to this configuration, fuel can be evenly distributed to a plurality of additional burners with a simple configuration.

Among the plurality of additional burners, a first fuel header that distributes the first fuel mainly composed of methane to a predetermined number of additional burners, and the remaining predetermined number of additional burners contain hydrogen gas or hydrogen. You may provide the 2nd fuel header which distributes the 2nd fuel which consists of gas.

こ の According to this configuration, fuel can be distributed to a plurality of additional burners with a simple configuration.

Moreover, the gas turbine of the present invention includes any one of the combustors described above. According to this structure, the gas turbine provided with the combustor which can suppress the discharge | emission amount of NOx can be provided.

According to the present invention, it is possible to provide a gas turbine combustor and a gas turbine that can reduce NOx emissions.

It is a figure showing a schematic structure of a gas turbine concerning an embodiment of the invention. It is a longitudinal cross-sectional view of the combustor which concerns on embodiment of this invention. 2A is a sectional view in the axial direction of the combustor viewed from the direction AA in FIG. 2, FIG. 2B is a sectional view in the axial direction of the combustor viewed from the direction BB in FIG. 2, and FIG. FIG. 3D is an axial sectional view of the combustor viewed from the CC direction in FIG. 2, and FIG. 4D is an axial sectional view of the combustor viewed from the DD direction in FIG. It is sectional drawing which shows the modification of a chasing burner (fuel injection nozzle).

Hereinafter, a combustor for a gas turbine and a gas turbine according to an embodiment of the present invention will be described with reference to the accompanying drawings. Note that the following description is merely an example of one embodiment of the present invention, and is not intended to limit the present invention, its application, or its use.

Fig. 1 shows the schematic configuration and functions of the gas turbine. In the gas turbine 1, the compressor 2 sucks the atmosphere and generates compressed air 200. The compressed air 200 is combusted together with fuel in the combustor 3 to generate high-temperature and high-pressure combustion product gas (hereinafter referred to as “combustion exhaust gas 300”). The combustion exhaust gas 300 is supplied to the turbine 4 and used for rotating the rotor 5. The rotation of the rotor 5 is transmitted to the compressor 2 and used to generate compressed air 200 (hereinafter referred to as “combustion air 200”), while the rotation of the rotor 5 is transmitted to the generator 6 to generate power. Used for

FIG. 2 shows the combustor 3. In the present embodiment, the combustor 3 includes a flow direction of compressed air 200 supplied from a compressor (see FIG. 1) (a direction from the top to the bottom in FIG. 1) and a flow direction of combustion exhaust gas 300 (see FIG. 1). Is a backflow can type combustor which is opposed to each other inside. The type of the combustor may be an annular type having a plurality of fuel injection valves on the circumference.

The combustor 3 includes a combustion cylinder 34 and a casing 35 that are arranged concentrically on the central axis 302. A burner unit 30 is attached to the top of the combustion cylinder 34, and a combustion chamber 33 for burning fuel or the like injected from the burner unit 30 is formed inside the combustion cylinder 34. The combustion cylinder 34 is surrounded by a cylindrical casing 35, and an annular combustion air flow path 37 through which the combustion air 200 supplied from the compressor flows is formed between the combustion cylinder 34 and the casing 35. ing. The casing 35 and the combustion cylinder 34 support a plurality of reheating burners 36 on the downstream side of the burner unit 30.

In the present embodiment, the burner unit 30 is disposed along the central axis 302 and premixed main burner 31 that injects a premixed gas generated by mixing fuel and combustion air 200 into the combustion chamber 33. And a diffusion combustion type pilot burner 32 for directly injecting fuel into the combustion chamber 33. The main burner 31 is arranged concentrically around the pilot burner 32. The main burner 31 and the pilot burner 32 are in communication with the first fuel supply source 305 through a pipe 304.

In the present embodiment, the main burner 31 has an outer cylinder 310 and an inner cylinder 312 that are arranged concentrically along the central axis 302. As shown in the figure, the inner cylinder 312 also serves as a combustion air injection cylinder 322b of a pilot burner 32 described later. An annular space between the outer cylinder 310 and the inner cylinder 312 is used as a premixing channel 314 for mixing fuel and combustion air. The pilot burner 32 includes a fuel injection cylinder 322a extending along the central axis 302 and a combustion air injection cylinder 322b concentrically mounted on the fuel injection cylinder 322a, and a fuel injection path formed in the fuel injection cylinder 322a. (Not shown) is connected to the first fuel supply source 305 via a pipe 304b including a flow rate adjustment valve. By opening the flow rate adjustment valve at the time of startup, the first fuel supply source 305 The supplied natural gas is injected into the combustion chamber 33. An annular air flow path 324 is formed between the fuel injection cylinder 322a and the combustion air injection cylinder 322b, one end of which is connected to the combustion air flow path 37 and the other end is connected to the combustion chamber 33. The combustion air 200 supplied from the compressor is injected into the combustion chamber 33.

The premix channel 314 has one end opened to the combustion chamber 33 and the other end opened to the combustion air channel 37 through the plurality of air intake ports 315 toward the radially outer side. A plurality of main fuel nozzles 316 for ejecting the first fuel are arranged outside the air intake port 315 in the radial direction. Although not shown, the plurality of air intake ports 315 and the plurality of main fuel nozzles 316 corresponding to the plurality of air intake ports 315 are preferably arranged at equal intervals in the circumferential direction around the central axis 302.

Each main fuel nozzle 316 is formed with a plurality of fuel injection holes (not shown) for injecting the first fuel toward the air intake 315 at a portion facing the air intake 315, while adjusting the flow rate. It is connected to the first fuel supply source 305 through a pipe 304a including a valve. Thus, the fuel supplied from the first fuel supply source 305 and the combustion air 200 supplied from the combustion air flow path 37 together with the combustion air 200 supplied from the first fuel supply source 305 are opened by opening the flow rate adjustment valve during normal operation. 315 is supplied to the premixing flow path 314 and mixed in the premixing flow path 314, and the premixed gas is injected into the combustion chamber 33. In the present embodiment, the air intake 315 is provided with a plurality of swirl vanes (swirlers) that impart a swirl force to the combustion air 200 flowing into the premixing flow path 314 to promote premixing with the first fuel. 317 is provided.

The reheating burner 36 is a diffusion combustion type burner, and includes a cylindrical fuel injection nozzle 38 and an air hole 340. As shown in FIG. 3, the fuel injection nozzle 38 is included in a casing 35 along eight axial centers 360 that are included in a plane orthogonal to the central axis 302 and are arranged at equal intervals (45 ° intervals) in the circumferential direction. And attached to the combustion cylinder 34, respectively. In the present embodiment, eight fuel injection nozzles 38a-1 to 38a-8, 38b-1 to 38b-8, 38c-1 to 38c-8, and 38d-1 to 38d-8 each have one fuel injection nozzle row. The four fuel injection nozzle rows 38a, 38b, 38c, 38d are arranged at predetermined intervals along the direction of the central axis 302 (see FIG. 2).

As shown in FIGS. 2 and 3, in the present embodiment, the upstream ends of the plurality of fuel injection nozzles 38a-1 to 38a-8, 38c-1 to 38c-8 constituting the fuel injection nozzle rows 38a and 38c. The first fuel headers 39a and 39c for distributing the first fuel to the fuel injection nozzles 38a-1 to 38a-8 and 38c-1 to 38c-8 are connected to the section. The first fuel headers 39a and 39c are connected to a first fuel supply source 305 via a pipe 306 including a flow rate adjustment valve.

On the other hand, at the upstream end of the plurality of fuel injection nozzles 38b-1 to 38b-8 and 38d-1 to 38d-8 constituting the fuel injection nozzle rows 38b and 38d, the fuel injection nozzles 38b-1 to 38b- Second fuel headers 39b and 39d for distributing the second fuel are connected to 8, 38d-1 to 38d-8. The second fuel headers 39b and 39d are connected to the second fuel supply source 307 via a pipe 308 including a flow rate adjusting valve. When the flow rate adjusting valve is opened during high load operation, The fuel and the second fuel are configured to be injected into the combustion chamber 33. The said 1st fuel shows the liquid containing 60 volume% or more of hydrocarbons, the gas which hydrogen gas is 10 volume% or less, or 60 volume% or more of hydrocarbons. The second fuel indicates a gas containing 50% by volume or more of hydrogen. In the present embodiment, natural gas is illustrated as an example of the first fuel, and hydrogen gas is illustrated as an example of the second fuel.

The first and second fuel headers 39a, 39c, 39b, and 39d are formed in a ring shape and arranged so as to surround the outer casing 35. Further, the fuel injection nozzles 38a-1 to 38a-8, 38b-1 to 38b-8, 38c-1 to 38c-8, 38d-1 to 38d-8 are provided with respective fuel injections on the peripheral wall of the combustion cylinder 34. An air hole 340 for taking a part of compressed air 200 as combustion air from around the nozzles 38a-1 to 38a-8, 38b-1 to 38b-8, 38c-1 to 38c-8, 38d-1 to 38d-8. (See FIGS. 2 and 3).

Next, features of the combustor 3 of the present embodiment will be described below. 3 (a) to 3 (d) show the AA arrow cross section, the BB arrow cross section, the CC arrow cross section, and the DD arrow cross section in FIG. As shown in FIGS. 3A and 3C, the angular positions of the eight fuel injection nozzles 38a-1 to 38a-8 constituting the fuel injection nozzle row 38a and the eight fuels constituting the fuel injection nozzle row 38c. The angular positions of the injection nozzles 38c-1 to 38c-8 are the same.

On the other hand, as shown in FIG. 3 (b), the angular positions of the eight fuel injection nozzles 38b-1 to 38b-8 constituting the fuel injection nozzle row 38b are respectively equal to the eight fuel injection nozzle rows 38a and 38c. The fuel injection nozzles 38a-1 to 38a-8 and 38c-1 to 38c-8 are arranged so as to be shifted by a half pitch angle (22.5 degrees) with respect to the angular positions.

Similarly, as shown in FIG. 3 (d), the eight fuel injection nozzle rows 38d-1 to 38d-8 constituting the fuel injection nozzle row 38d are also at the angular positions of the eight fuel injection nozzle rows 38c. They are arranged with a half-pitch angle (22.5 degrees) shifted from the angular positions of the injection nozzles 38c-1 to 38c-8. That is, the fuel injection nozzles 38a-1 to 38a-8, 38b-1 to 38b-8, 38c-1 to 38c-8, 38d-1 to 38d-8 arranged in adjacent rows are staggered in the circumferential direction. It is arranged.

Next, the operation of the combustor 3 having the above-described configuration will be described below with reference to FIG. As shown in FIG. 2, when the gas turbine (not shown) is started, the flow rate adjustment valve is opened, and the first fuel supplied from the first fuel supply source 305 to the pilot burner 32 via the pipe 304b. (Natural gas) is injected into the combustion chamber 33. Subsequently, the combustion air 200 injected from the annular air flow path 324 into the combustion chamber 33 is diffused and mixed in the combustion chamber 33 and ignited by an ignition source (not shown) to form a pilot flame by diffusion combustion.

When the gas turbine shifts to the normal operation, the first fuel supplied from the first fuel supply source 305 to each main fuel nozzle 316 via the pipe 304a and the combustion air 200 flowing from the air intake port 315 are main. Mixing in the premixing flow path 314 of the burner 31 generates premixed gas. Subsequently, the premixed gas injected from the premixing flow path 314 is ignited by the pilot flame in the combustion chamber 33 and burns in the primary combustion region S <b> 1 on the base end side of the combustion chamber 33. By burning the lean premixed gas, the combustion flame temperature in the combustion chamber 33 is lowered, and the amount of NOx in the combustion exhaust gas of the main burner 31 is suppressed.

When high-load combustion is required to increase the output of the gas turbine, the memorial burner 36 operates as follows. The first fuel is supplied to the first fuel headers 39a and 39c, and the first fuel passes through the eight fuel injection nozzles 38a-1 to 38a-8 constituting the fuel injection nozzle row 38a and the fuel injection nozzle row 38c. The eight fuel injection nozzles 38 c-1 to 38 c-8 constituting the same are equally distributed, and the first fuel is injected from the side of the flow of the combustion exhaust gas 300.

Similarly, the second fuel (hydrogen gas) is supplied to the second fuel headers 39b and 39d, and the second fuel includes eight fuel injection nozzles 38b-1 to 38b-8 constituting the fuel injection nozzle row 38b. The fuel is equally distributed to the eight fuel injection nozzles 38d-1 to 38d-8 constituting the fuel injection nozzle row 38d, and the second fuel is injected from the side of the flow of the combustion exhaust gas 300. The supply amount and ratio of the first fuel (natural gas) and the second fuel (hydrogen gas) are appropriately determined according to the combustion conditions.

Thus, by having the first fuel headers 39a and 39c and the second fuel headers 39b and 39d, each of the eight fuel injection nozzles 38a-1 to 38a-8 and 38b-1 to 38b-8 can be achieved with a simple configuration. , 38c-1 to 38c-8, and 38d-1 to 38d-8, the target fuel can be evenly distributed.

The first fuel injected from the fuel injection nozzles 38a-1 to 38a-8, 38c-1 to 38c-8, and the fuel injected from the fuel injection nozzles 38b-1 to 38b-8, 38d-1 to 38d-8 The second fuel is burned from the periphery of the fuel injection nozzles 38a-1 to 38a-8, 38b-1 to 38b-8, 38c-1 to 38c-8, 38d-1 to 38d-8 through the air holes 340. It diffuses and mixes with a part of the combustion air 200 flowing into the chamber 33. The fuel for refueling (natural gas and hydrogen gas) is fuel injection nozzles 38a-1 to 38a-8, 38b-1 to 38b-8, 38c-1 to 38c-8, 38d-1 to 38d-8. Since the fuel is distributed and supplied into the combustion chamber 33, the fuel flow rate per one burner burner 36 is reduced. Therefore, the fuel concentration in the combustion region of each additional burner 36 is reduced compared with the case where a plurality of additional burner 36 are arranged only in the circumferential direction, and the overall combustion temperature can be kept low. As a result, it depends on the combustion temperature. The amount of NOx in the combustion gas 300 can be suppressed.

As described above, the combustors 3 according to the embodiments of the present invention have the fuel injection nozzles 38a-1 to 38a-8, 38b-1 to 38b-8, 38c-1 to 38c- arranged in adjacent rows. 8, 38d-1 to 38d-8 are staggered in the circumferential direction. By configuring in this way, the combustion of the reheating burner disposed on the downstream side becomes less affected by the combustion of the reheating burner disposed on the upstream side, and the combustion of the downstream reheating burner is stabilized. Can do. The eight fuel injection nozzles 38a-1 to 38a-8, 38b-1 to 38b-8, 38c-1 to 38c-8, 38d- constituting the four fuel injection nozzle rows 38a, 38b, 38c, 38d- The angular positions 1 to 38d-8 may coincide with each other.

The combustion exhaust gas 300 increased by burning the first and second fuels introduced from the reheating burner 36 is sent to the gas turbine and used for adjusting the output of the gas turbine.

The embodiment described above can be variously modified. For example, in the above embodiment, hydrogen gas as the second fuel is injected from the fuel injection nozzles 38b-1 to 38b-8 and 38d-1 to 38d-8. Since the mass of hydrogen gas is considerably smaller than the mass of air (a mixture of oxygen and nitrogen), the main flow of the flow of the combustion exhaust gas 300 is merely applied to the flow of the combustion exhaust gas 300 from the side thereof. (Middle part) may not be reached. Therefore, for example, as shown in FIGS. 4 (a) and 4 (b), hydrogen gas is introduced into the opening at the downstream end of the fuel injection nozzles 38b-1 to 38b-8 (38d-1 to 38d-8). You may form the aperture | diaphragm | squeeze part 40 which raises the kinetic energy at the time of jetting. According to such a configuration, the hydrogen gas can be intentionally sent to the main flow (center portion) of the flow of the combustion product gas. As a result, a combustion flame having a uniform concentration distribution as a whole can be formed in the secondary combustion region S2.

Further, in the above-described embodiment, the configuration in which the first fuel is supplied to the fuel injection nozzle rows 38a and 38c and the second fuel is supplied to the fuel injection nozzle rows 38b and 38d is exemplified. It is not restricted to such a form. The fuel header is manufactured in an appropriate structure, and, for example, among the fuel injection nozzles 38a-1 to 38a-8, the first fuel is injected from the fuel injection nozzles 38a-1, 38a-3, 38a-5, and 38a-7. It is also possible to adopt a configuration in which the second fuel is injected from the remaining fuel injection nozzles 38a-2, 38a-4, 38a-6, 38a-8 (the fuel injection nozzle rows 38b, 38c, 38d are provided). The same applies to the constituent fuel injection nozzles 38b-1 to 38b-8, 38c-1 to 38c-8, and 38d-1 to 38d-8).

In the above-described embodiment, an example in which the four fuel injection nozzle rows 38a, 38b, 38c, and 38d are arranged at predetermined intervals along the direction of the central axis 302 has been described. The number only needs to be at least two columns, and the number can be changed as appropriate. In the above-described embodiment, the fuel injection nozzles 38 are supported on the outer casing 35 at eight equal intervals (45 degree intervals). However, the number of the fuel injection nozzles 38 is at least two. Often, the number can be changed as appropriate. Needless to say, the pitch angle for shifting the angular position of each fuel injection nozzle in the opposed fuel injection nozzle rows also changes by changing the number of fuel injection nozzles 38.

In the above-described embodiment, the first fuel is supplied to the first fuel headers 39a and 39c and the second fuel is supplied to the second fuel headers 39b and 39d. It is also possible to supply the first fuel or the second fuel to all of the first fuel headers 39a and 39c and the second fuel headers 39b and 39d.

DESCRIPTION OF SYMBOLS 1 Gas turbine 2 Compressor 3 Combustor 4 Turbine 5 Rotor 6 Generator 31 Main burner 32 Pilot burner 33 Combustion chamber 34 Combustion cylinder 36 Combustion burner 37 Combustion air flow path (air flow path)
38 Fuel injection nozzles 38a to 38d Fuel injection nozzle arrays 39a, 39c First fuel headers 39c, 39d Second fuel headers 40 Restricted portions 200 Compressed air (combustion air)
300 Combustion exhaust gas 302 Center axis 360 Center axis

Claims (5)

A gas turbine combustor that mixes and burns fuel with compressed air introduced from a compressor and supplies the generated combustion exhaust gas to a gas turbine,
A combustion cylinder forming a combustion chamber therein;
A premixed combustion type main burner disposed upstream of the combustion cylinder;
A plurality of diffusion combustion type burner burners that are arranged downstream of the main burner and penetrate the peripheral wall of the combustion cylinder and inject fuel into the combustion chamber from the peripheral wall;
The gas turbine combustor, wherein the plurality of additional burners are arranged in a circumferential direction and an axial direction of a combustion cylinder. The gas turbine combustor according to claim 1, wherein the plurality of reheating burners arranged in adjacent rows are arranged in a staggered manner in the circumferential direction. The gas turbine combustor according to claim 1 or 2, further comprising a fuel header that distributes the fuel to each of the plurality of additional burners. A first fuel header that distributes a first fuel mainly composed of methane to a predetermined number of additional burners among the plurality of additional burners;
The combustion for a gas turbine according to any one of claims 1 to 3, further comprising a second fuel header that distributes a second fuel made of hydrogen gas or a hydrogen-containing gas to the remaining predetermined number of burner burners. vessel. A gas turbine comprising the combustor according to any one of claims 1 to 4.

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