JP5878428B2 - Gas turbine combustor and method of operating gas turbine combustor - Google Patents

Description

  The present invention relates to a gas turbine combustor, and more particularly to a burner structure of a gas turbine combustor capable of stable combustion of a flame-retardant gas and a gas having a low calorific value.

  In general, a fuel having a low calorific value is a fuel that is difficult to burn because the flame temperature is low and the combustion speed is slow compared to LNG (Liquefied Natural Gas), which is the main fuel of gas turbines. Another feature is that the amount of NOx emissions during combustion is small. A typical example of such a low calorie gas is blast furnace gas. Blast furnace gas is a by-product gas generated from the blast furnace in the iron making process. In recent years, from the viewpoint of effective use of resources, there is an increasing need to use this blast furnace gas as a gas turbine fuel.

The blast furnace gas is a flame retardant gas containing carbon monoxide (CO) and hydrogen (H ₂ ) as main combustible components and a large amount of N ₂ and CO ₂ in addition. For this reason, it is difficult to operate the rated load range from igniting the gas turbine by blast furnace gas-only firing, and in order to stably operate (combust) the partial load range from ignition, generally a separate starting fuel is required. In addition, in order to stably burn the flame-retardant gas, the gas turbine combustor adopts a diffusion combustion system that supplies fuel and air to the combustion chamber from separate flow paths, and a starting fuel such as liquid fuel and a low calorie gas. In general, the burner configuration is capable of burning the dual fuel.

Other low calorie gases include coal and biomass gasification gases. These coal and biomass fuels are also increasingly needed as gas turbine fuels from the viewpoint of effective use of resources. The fuel obtained by gasification with air using coal or wood chips as a raw material is a low calorie gas containing a large amount of N ₂ , and a starter fuel and a burner capable of burning the low calorie gas are required.

  Here, as a structural example of a low calorie gas burning burner for coal gasification gas, Patent Document 1 (Japanese Patent Laid-Open No. 5-86902) is cited. Patent Document 1 discloses a burner structure in which a starting oil nozzle is provided at the radial center of a burner, gas injection holes are arranged on the outer periphery thereof, and gas injection holes and air injection holes are alternately arranged on the outer periphery thereof. Is described.

  On the other hand, since high-calorie fuels such as LNG have a high flame temperature during combustion, some contrivance is required for low NOx combustion. An example of the combustion method is lean premixed combustion. In addition, since premixed combustion has a narrower stable combustion range than diffusion combustion, it is common to enhance the combustion stability of the premixed flame with a pilot burner employing a diffusion combustion method. In the premixer, a mixing distance for uniformly mixing the fuel and air is required, and therefore, the premix burner tends to protrude to the downstream side of the combustion chamber rather than the pilot burner.

  As an example of such a structure, in Patent Document 2, a pilot burner for flame stabilization and a premixing burner for low NOx combustion are combined, and most of the air supplied to the combustor is used as a premixer. A description is given of supplying fuel and air in advance and reducing NOx by lean premix combustion.

Japanese Patent Laid-Open No. 5-86902 JP-A-8-86407

  Generally, low-calorie gas is a fuel that is difficult to burn because it has a lower flame temperature and a slower combustion speed than a high-calorie fuel such as LNG. Therefore, in a gas turbine combustor, a stable combustion technique of low calorie gas becomes an important issue. Moreover, since the calorific value is low, it is necessary to increase the flow rate of fuel supplied to the combustor in order to obtain a combustion gas temperature equivalent to a high calorie gas such as LNG. For this reason, the low-calorie gas-fired combustor is also characterized in that the fuel flow rate to be supplied is increased.

In the burner structure described in Patent Document 1, when blast furnace gas is burned, the CO ₂ content is higher than that of coal gasification gas, so the flame temperature formed on the inner swirler is lowered and supplied from the outer swirler. The reaction of the fuel to be done tends to become slow. Accordingly, the CO emission concentration at the combustor outlet is likely to increase, and when the calorific value of the blast furnace gas is further reduced, the flame may be easily blown off. In addition, when blast furnace gas is burned with the burner structure described in Patent Document 2 that performs premixed combustion with a narrow stable combustion range, the possibility that a flame will blow out increases, and it may be difficult to perform the combustion itself.

An object of the present invention is to provide a gas turbine combustor capable of stably burning even a flame-retardant low-calorie gas such as a blast furnace gas containing a large amount of CO ₂ .

The present invention relates to a combustor including a combustion chamber in which fuel and air are mixed and combusted, and a burner that supplies the fuel and air to the combustion chamber and holds a flame, wherein the burner is a gas that ejects fuel. A first swirler having a nozzle hole and an air nozzle for ejecting air, and provided with the gas nozzle hole and the air nozzle hole; and a second swirler provided with the gas nozzle hole. wherein the second swirler is disposed on the outer periphery of the first swirler, and than said first swirler being configured to protrude into the combustion chamber downstream, the second swirler, the An air flow path for supplying air to the first swirler, and the air flow path protrudes further downstream of the combustion chamber than the first swirler by air supplied to the first swirler; be configured to allow cooling of the inner circumferential wall of said second swirler And features.

The present invention can provide a gas turbine combustor capable of stable combustion even the low-calorie gas flame retardancy, such as blast furnace gas containing CO ₂ in a large amount.

It is a combustor structure and a system diagram showing the first feature of the present invention. It is a front view of the burner which shows the 1st characteristic of this invention. It is sectional drawing of the burner which shows the 1st characteristic of this invention. It is a figure which shows the relationship between fuel concentration and theoretical flame temperature. It is sectional drawing of the burner which shows the 2nd characteristic of this invention. It is a front view of the burner which shows the 2nd characteristic of this invention. It is a burner structure figure which shows the 3rd characteristic of this invention.

  In order to solve the above problems, it is necessary to increase the flame temperature formed on the inner swirler to promote the combustion reaction. One of the causes that the combustion reaction becomes slow is that the flame formed in the inner swirler is cooled by the fuel supplied from the outer swirler. This is particularly noticeable in the combustion of gas with a low calorific value. In the combustion of blast furnace gas where the local flame temperature becomes low, if the outer peripheral fuel is mixed (joined) before the flame temperature formed in the inner swirler rises, the temperature of the inner peripheral flame further decreases and the reaction becomes slow Prone.

  In the burner described in each embodiment of the present invention described below, the outer peripheral swirler is protruded to the downstream side of the combustion chamber rather than the inner peripheral swirler. Therefore, it is possible to prevent a temperature drop of the inner peripheral flame due to mixing of the outer peripheral fuel before the temperature of the inner peripheral flame formed in the inner peripheral swirler increases. Further, air supplied to the inner swirler or fuel ejected from the outer swirler is used as a cooling medium for the inner peripheral wall of the protruding outer swirler. Therefore, it is possible to raise the temperature of air and fuel by wall surface cooling, and to raise the flame temperature of the inner swirler and the outer flame temperature of the outer swirler. Thus, by raising the flame temperature formed on the inner swirler and promoting the combustion reaction, it becomes possible to stably burn the blast furnace gas.

  In addition, the lean premix combustor for LNG shown in Patent Document 2 has a configuration in which an annular premix burner is protruded downstream of the combustion chamber from a pilot burner provided on the inner periphery thereof. ing. This is a pilot burner placed on the inner circumference of an annular premix burner for the purpose of stable combustion from the ignition and start-up of the gas turbine to the partial load range and stable combustion of the premixed flame for low NOx. . In Patent Document 2, the partial load range from ignition and start-up is operated only by the pilot burner. However, in the burner described in each embodiment of the present invention, the partial load range for burning the low calorie gas also includes the inner swirler and the outer swirler. Stable combustion is achieved by the interaction of the flames formed on both sides.

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

(Combustor configuration)
FIG. 1 shows an enlarged cross-sectional view of a gas turbine system and a combustor according to a first embodiment of the present invention. The gas turbine 5 includes a compressor 2, a combustor 3, a turbine 4, a generator 6, a starter motor 8, and the like. The gas turbine 5 compresses the air 101 sucked from the atmosphere by the compressor 2 and supplies the combustion air 102 to the gas turbine combustor 3. In the combustor 3, the combustion air 102 produced by the compressor 2 and the blast furnace gas 60 are mixed with a heat increasing gas 70 (supplied in the range of ignition to partial load) mixed with the coke oven gas 80 to generate the combustion gas 140 to the turbine 4. Supplied. The turbine 4 is supplied with rotational power by supplying the combustion gas 140, and the rotational power of the turbine 4 is transmitted to the compressor 2 and the generator 6. The rotational power transmitted to the compressor 2 is used as compression power, and the rotational power transmitted to the generator 6 is converted into electric energy.

  In the combustor 3, a combustion chamber 12 formed by a liner 14 is provided in an outer cylinder 10 that is a pressure vessel, and a flow sleeve 11 for cooling the combustion chamber is provided on the outer periphery of the liner 14. Further, a burner 300 is provided upstream of the combustion chamber 12 to supply fuel and air to the combustion chamber 12 through separate flow paths and hold a flame. The combustion air 102 supplied to the combustor 3 flows in the space between the flow sleeve 11 and the combustion chamber 12, and the combustion air hole 13 provided in the liner 14 while cooling the combustion chamber 12 and the air provided in the burner 300. The fuel is supplied into the combustion chamber 12 through the nozzle holes 402 and the like.

  The burner 300 employs a double swirl structure including an inner peripheral swirler 201 and an annular outer peripheral swirler 202 disposed on the outer periphery thereof. Further, the outer peripheral swirler 202 is configured to protrude to the downstream side of the combustion chamber from the inner peripheral swirler 201. The flow rate and calorific value of the low calorie gas supplied to the inner peripheral swirler 201 and the outer peripheral swirler 202 can be changed depending on the load condition of the gas turbine. The partial load range from the ignition of the gas turbine is stably combusted by supplying a heat increasing gas 70 obtained by mixing the coke oven gas 80 with the blast furnace gas 60. Thereafter, as the fuel flow rate is increased and the combustion temperature increases, the load increases. When a high load condition (for example, the intermediate load to the rated load range) is reached, only the blast furnace gas 60 can be operated.

  The supply pressure of the low calorie gas can be adjusted by a pressure regulating valve 150 provided in the fuel system, and downstream thereof, a first fuel system 51 for supplying the inner peripheral fuel 201f to the inner peripheral swirler 201, A second fuel system 52 for supplying the outer peripheral fuel 202f to the outer peripheral swirler 202 is provided. Each fuel system includes a first fuel flow rate adjustment valve 41 and a second fuel flow rate adjustment valve 42, and the control device 200 can adjust the fuel flow rate of the inner and outer swirlers from the ignition to the rated load range. It is.

(Burner structure 1)
FIG. 2 shows a front view of the burner 300. This figure is a view of the burner 300 from the downstream side. The burner of this embodiment has a double swirl burner structure constituted by an inner circumferential swirler 201 and an outer circumferential swirler 202.

The combustion of blast furnace gas containing CO ₂ in a large amount is required to raise the flame temperature of the inner flame 250 formed by the inner peripheral swirler. Therefore, the burner of the present embodiment includes an inner peripheral swirler 201 in which gas injection holes 401 for injecting inner peripheral fuel 201f and air injection holes 402 for injecting air 102a are alternately provided in the circumferential direction, and outer peripheral fuel 202f. And an outer peripheral swirler 202 provided with a gas injection hole 403 to be ejected.

  Each nozzle hole is provided with a turning angle α as shown in the AA cross-sectional view of FIG. Therefore, a flame holding region (circulation gas region) at a low speed is formed in the vicinity of the center portion in the radial direction of the burner, and the combustion stability can be enhanced. Further, the burner according to the present embodiment includes a flame-holding gas injection hole 404 on the radially inner side of the gas injection hole 401 and the air injection hole 402 of the inner peripheral swirler 201. By supplying flame holding fuel 203f from the flame holding gas nozzle 404, it becomes possible to increase the fuel concentration in the circulating gas region formed near the radial center of the inner swirler and improve combustion stability. Can be made.

On the other hand, as shown in FIG. 1, in the outer peripheral swirler 202, the outer peripheral fuel 202 f is supplied from the gas injection hole 401. The outer peripheral fuel 202f is mixed with the air 102a supplied from the inner peripheral swirler 201 and the air in the vicinity of the burner supplied to the combustion chamber 12, and based on the flame (inner peripheral flame) formed in the inner peripheral swirler 201, A flame (peripheral flame) is formed in the swirler. Since the temperature around the inner flame is increased by the formation of the outer flame, flame holding can be strengthened. In particular, it is effective for combustion of low calorie gas containing a large amount of CO ₂ such as blast furnace gas.

In general, a fuel having a high CO ₂ content such as blast furnace gas has a high density, and when the flame is held by a swirling flow as in this embodiment, the fuel having a high density is likely to penetrate to the outside by an inertial force. Therefore, in the burner 300 of this embodiment, the fuel supplied to the burner is divided into an inner swirler and an outer swirler, and a fuel injection hole and an air injection hole are provided in the inner swirler. This makes it possible to adjust the fuel flow rate so that, for example, the concentration at which the fuel and air are mixed is the stoichiometric mixture ratio, and to increase the flame temperature formed in the inner swirler as much as possible. Can be improved.

That is, by introducing air into the inner swirler, mixing of a part of the fuel that easily penetrates to the outside and the air is promoted, and the inner flame that covers the flame can be stabilized. Further, in the present embodiment, the outer peripheral flame is formed by mixing the fuel supplied from the outer swirler with the inner peripheral flame as a fire type and the combustion air flowing in from the combustion air hole 13 provided in the wall surface of the liner 14. It is characterized by stable combustion of a fuel having a high CO ₂ content by the above interaction.

  Next, FIG. 3 shows a cross-sectional view of the burner 300. In the burner of this embodiment, the outer swirler 202 protrudes to the combustion chamber downstream side (the right side in FIG. 3) with respect to the inner swirler 201, and the air 102a is supplied to the inner swirler 201 inside the protruding outer swirler 202. An air flow path 275 is provided. A plurality of air introduction holes 402 a for introducing the air 102 a into the air flow path 275 are provided in the outer peripheral wall 271 near the front end (combustion chamber side end face) of the outer peripheral swirler 202. With such a configuration, in the burner of the present embodiment, the inner peripheral wall 270 of the outer peripheral swirler 202 is cooled by the air 102a flowing down the air flow path 275 and the outer peripheral fuel 202f ejected from the outer peripheral swirler 202, and the cooled air 102a Can be used as combustion air for the inner swirler 201.

  As described with reference to FIG. 2, in the burner according to the present embodiment, the circulation gas regions 30 and 31 are formed in the vicinity of the center portions in the radial direction of the inner swirler 201 and the outer swirler 202. In the inner peripheral swirler 201, a part of the combustion gas is circulated by the circulating gas region 30, and the flame is held by continuously supplying heat to the inner peripheral fuel 201f and the air 102a to be supplied. Furthermore, the fuel concentration in the circulating gas region 30 is increased by supplying the flame-holding fuel 203f, and the combustion stability is improved. Also in the outer peripheral swirler 202, the circulating gas region 31 is formed by the swirling jet of gas fuel, and the heat of the outer peripheral flame is taken into the circulating gas region 30 of the inner peripheral swirler 201. Since the outer peripheral fuel 202f can utilize the heat from the inner peripheral flame 250, the reaction is activated, and the double swirl burner enables stable combustion of low calorie gas.

  In such a burner structure, when the outer peripheral swirler 202 is protruded downstream from the inner peripheral swirler 201, the inner peripheral flame 250 is formed on the inner periphery upstream of the outer peripheral swirler 202. At this time, in the inner circumferential swirler 201, the mixing and combustion of the inner circumferential fuel 201f and the air 102a proceed, so that the temperature of the inner circumferential flame 250 sufficiently increases. Compared to a double swirl burner in which the outer swirler is configured on the same surface, the outer peripheral fuel 202f is mixed on the downstream side of the inner peripheral flame 250 where the temperature of the inner peripheral flame 250 is sufficiently increased, so that stable combustion is possible. . In particular, when the amount of heat generated by the gas is low, the effect becomes remarkable.

  As described above, in the burner 300 of the present embodiment, the outer peripheral swirler 202 provided with the gas injection holes 403 protrudes downstream of the combustion chamber than the inner peripheral swirler 201 provided with the gas injection holes 401 and the air injection holes 402. Is configured to do. Therefore, since the outer peripheral fuel 202f can be mixed after sufficiently increasing the temperature of the inner peripheral flame 250 formed in the inner peripheral swirler 201, the outer peripheral fuel 202f is mixed before the temperature of the inner peripheral flame 250 increases. By doing so, the temperature drop of the inner peripheral flame 250 can be prevented, and the combustion stability of the inner peripheral flame 250 can be improved.

  Further, since the outer peripheral fuel 202f ejected from the outer swirler 202 can be heated by the heat from the inner peripheral flame 250 when flowing down the outer peripheral swirler 202, the flame temperature of the outer peripheral flame 260 formed on the outer peripheral swirler 202 is set. The combustion stability of the outer peripheral flame 260 can be improved. Further, since the heat of the outer peripheral flame 260 is taken into the inner peripheral flame 250 by the circulating gas region 31, the combustion stability of the inner peripheral flame 250 can be improved by increasing the flame temperature of the outer peripheral flame 260.

  Further, the outer swirler 202 has an air flow path 275 for supplying air 102a to the inner swirler 201, and the air flow path 275 is provided inside the protruding outer swirler 202 by the air 102a supplied to the inner swirler. It is comprised so that the surrounding wall 270 can be cooled. By using it for cooling the inner peripheral wall 270, the temperature of the air 102 a can be increased, and the flame temperature of the inner peripheral flame 250 can be increased. And the flame temperature of the inner periphery flame 250 formed in the inner periphery swirler 201 can be raised, and the combustion stability of the inner periphery flame 250 can be improved.

In this way, by increasing the combustion temperature of each flame to promote the combustion reaction and improving the combustion stability, it is possible to stably burn incombustible low calorie gas such as blast furnace gas containing a large amount of CO _2. be able to.

  In the above description, the fuel system has been described as two systems. However, even if the fuel flow rate supplied to the inner swirler and the outer swirler is set to optimum conditions in advance, even when the fuel is controlled by one system. Stable combustion is possible. Furthermore, in the present embodiment, the description has been made on the assumption that the gas turbine is ignited by the heated gas and the load change, but even when the oil nozzle for liquid fuel is arranged at the center in the radial direction of the double swirl burner, Stable combustion is possible.

(how to drive)
The burner operation method described above will be described with reference to FIG. At startup, the gas turbine is driven by external power such as a starter motor 8. By maintaining the rotational speed of the gas turbine at a rotational speed corresponding to the ignition condition of the combustor, the combustion air 102 necessary for ignition is supplied to the combustor 3 and the ignition condition is established. By mixing the coke oven gas 80 with the blast furnace gas 60 and supplying the heated gas 70 to the double swirl burner 300, ignition in the combustor 3 becomes possible. After the combustor is ignited, the combustion gas 140 is supplied to the turbine 4, the turbine 4 is accelerated with the increase in the flow rate of the heat-increasing gas 70, and the gas turbine enters a self-sustaining operation when the starter motor 8 is detached. To reach. After the gas turbine reaches the no-load rated rotational speed, the inlet gas temperature of the turbine 4 rises due to the addition of the generator 6 and the increase in the flow rate of the heat-increasing gas 70, and the load rises. As the load increases, the combustion stability increases when the combustor outlet gas temperature rises. Therefore, it becomes possible to stop the supply of the coke oven gas 80 supplied for heat increase.

  In the burner 300, the flame can be stably held by the interaction between the inner peripheral flame 250 formed on the inner peripheral swirler 201 and the outer peripheral flame 260 formed on the outer peripheral swirler 202 even if the blast furnace gas 60 is exclusively burned. In particular, since the burner 300 of the present embodiment projects the outer swirler 202 to the combustion chamber downstream side with respect to the inner swirler 201, the outer fuel 202f joins and mixes before the temperature of the inner flame 250 sufficiently rises. Thus, the inner flame temperature can be prevented from lowering and stable combustion can be achieved. The air 102a supplied to the inner peripheral swirler 201 is air that has cooled the inner peripheral wall 270 of the outer peripheral swirler 202, and the temperature of the inner peripheral flame 250 increases as the air temperature rises, improving the combustion stability. Similarly, the inner peripheral wall 270 of the outer peripheral swirler 202 is also cooled by the outer peripheral fuel 202f, and the fuel temperature after cooling becomes higher, which contributes to the temperature increase of the outer peripheral flame 260.

  Furthermore, in this embodiment, the ratio of the fuel flow ratios of the two systems supplied to the burner can be adjusted, so that a heat increase with a high calorific value is ensured while ensuring a sufficient stable combustion margin for low-calorie gas. Low NOx combustion is possible for gas. That is, as shown in FIG. 4, stable combustion can be ensured by operating the low calorie gas such as the blast furnace gas B with an equivalence ratio of around 1.0. On the other hand, in the low-calorie gas, the heat-increased gas has a higher theoretical flame temperature in the vicinity of an equivalence ratio of 1.0, and therefore, the NOx emission amount increases compared to the blast furnace gas B. For this reason, in this embodiment, by controlling the equivalent ratio (fuel flow rate ratio) so that the theoretical flame temperature becomes the set temperature T ° C. with respect to the heat increasing gas, the low NOx combustion and the burner during the heat increasing gas operation are controlled. Can improve the reliability.

(Burner structure 2)
5 and 6 show the structure of a burner according to a second embodiment of the present invention. The present embodiment is different from the first example in that the air hole introducing portion provided in the outer peripheral wall 271 of the outer peripheral swirler 202 is constituted by a plurality of air hole introducing holes 402a, and the air flow path 275 is formed by the air hole introducing holes 402a. The impingement cooling structure cools by the impinging jet of air 102a from the air. FIG. 5 shows a cross section of a burner showing a second embodiment of the present invention. The advantage of using the impingement cooling system is that a wide area can be cooled with a small amount of air, and cooling can be efficiently performed by providing a cooling hole in an area where the temperature is high.

  In the burner structure as in the present embodiment, the inner peripheral flame 250 formed in the inner peripheral swirler 201 spreads out conically toward the downstream side of the combustion chamber, so that the wall surface temperature near the outlet of the outer peripheral swirler 202 tends to increase. In the present embodiment, in order to cool around the inner peripheral wall 270 near the downstream outlet portion of the outer peripheral swirler 202, the air hole introducing portion provided in the outer peripheral wall 271 of the outer peripheral swirler 202 is a plurality of small holes. A hole 402a is provided, and the air flow path 275 in the outer swirler 202 is cooled by a collision jet. When the inner flame 250 is wide and the temperature on the inner swirler 201 side (left side in FIG. 5) of the air flow path 275 of the outer swirler 202 rises, the air hole introduction hole 402a (impingement cooling hole). The metal temperature can be reduced by optimizing the position in the axial direction.

  Next, FIG. 6 shows a cross-sectional structure at the BB position in FIG. The flow path of the outer swirler 202 is provided with a plurality of air flow paths 275 that communicate with the air holes 402 of the inner swirler 201 and a plurality of gas fuel flow paths 276 that communicate with the gas injection holes 403 of the outer swirler 202, and these are arranged alternately. It is as. The inside (bottom surface) of the air flow path 275 can be efficiently cooled by the collision jet of the air 102a, and the gas fuel flow path 276 can be cooled by forced convection of the outer peripheral fuel 202f.

  Further, in the burner of this embodiment, the cooling efficiency can be improved by having a configuration in which the air flow path 275 is cooled by the collision jet of the air 102a from the air hole introduction hole 402a. In other words, improving the cooling efficiency means that the air 102a can be heated efficiently. That is, in the burner of the present embodiment that can efficiently heat the air 102a, the temperature of the air 102a ejected from the air nozzle hole 402 of the inner peripheral swirler 201 can be sufficiently increased. The flame temperature can be raised sufficiently, and the combustion stability of the burner can be improved.

(Burner structure 3)
FIG. 7 shows a cross-sectional view of a burner according to a third embodiment of the present invention. The feature of this embodiment is that the fuel and air flow paths provided in the outer peripheral swirler 202 are both annular flow paths (see section CC), and the air flow path 275 is more radial than the gas fuel flow path 276. Provided with a turbulent flow promoting rib 310 along the inner wall surface of the air flow path.

  In the operation from the ignition and start-up of the gas turbine to the rated load range, the fuel flow rate supplied to the inner swirler and the outer swirler may be changed in order to perform stable combustion even if the gas heat generation amount changes. At that time, if the flow rate of the outer peripheral fuel 202f supplied to the outer peripheral swirler 202 decreases, the cooling performance of the outer peripheral swirler may be insufficient.

  For this reason, this embodiment is characterized in that the inner peripheral wall 270 of the outer peripheral swirler 202 is cooled by the air 102a in which a constant flow rate is always supplied to the inner peripheral swirler 201. Thereby, even if the fuel flow rate supplied to the inner and outer swirlers changes, the outer swirler can always be cooled by the air 102a, and the reliability of the burner can be improved. In particular, in this embodiment, since the turbulent flow promoting rib 310 is provided in the annular air flow path, the inner peripheral wall 270 of the outer peripheral swirler 202 can be efficiently cooled by increasing the heat transfer area and amplifying the turbulence of the cooling air. Is possible.

  Further, in this embodiment in which the cooling efficiency is improved by providing the turbulent flow promoting rib 310, the air 102a supplied to the inner peripheral swirler 201 can be efficiently heated, and the air 102a is sufficiently heated. From the air nozzle hole 402 of the inner circumferential swirler 201. Therefore, the flame temperature of the inner peripheral flame 250 can be sufficiently increased, and the combustion stability of the burner can be improved.

2 Compressor 3 Combustor 4 Turbine 5 Gas turbine 6 Generator 8 Motor for starting 10 Outer cylinder 11 Flow sleeve 12 Combustion chamber (liner)
13 Combustion air hole 30 Circulating gas region 31 of inner swirler Circulating gas region 41 of outer swirler First fuel flow control valve (inner fuel system)
42 Second fuel flow control valve (peripheral fuel system)
51 First fuel system (inner fuel system)
52 Second fuel system (peripheral fuel system)
60 Low calorie gas (blast furnace gas)
70 Coal oven gas mixed with blast furnace gas 80 Coke oven gas 101 Air 102 Combustion air 102a Combustion air 140 of inner swirler 140 Combustion gas 150 Pressure control valve 200 Control device 201 Inner swirler 201f Inner fuel 202 Outer swirler 202f Outer peripheral fuel 203f Flame-holding reinforcing fuel 250 Inner peripheral flame 260 Outer peripheral flame 275 Air flow path 276 in the outer peripheral swirler Gas fuel flow path 300 in the outer peripheral swirler 300 Burner 310 Turbulent flow promoting rib 401 Gas injection hole 402 in the inner peripheral swirler Swirler air injection hole 403 Outer peripheral swirler gas injection hole 404 Inner peripheral swirler gas injection hole

Claims (9)

In a combustor comprising a combustion chamber for mixing and burning fuel and air, and a burner for supplying a fuel and air to the combustion chamber to hold a flame,
The burner has a gas nozzle for ejecting fuel and an air nozzle for ejecting air, the first swirler provided with the gas nozzle and the air nozzle, and the gas nozzle A second swirler provided,
The second swirler is arranged on the outer periphery of the first swirler, and is configured to protrude further downstream of the combustion chamber than the first swirler,
The second swirler has an air flow path for supplying air to the first swirler,
The air flow path is configured so that air supplied to the first swirler can cool an inner peripheral wall of the second swirler that protrudes further downstream of the combustion chamber than the first swirler. A gas turbine combustor. The gas turbine combustor according to claim 1 .
The second swirler has a plurality of air introduction holes for introducing air into the air flow path in an outer peripheral wall of the second swirler, and the air flow path is a collision jet of air from the air introduction hole. The gas turbine combustor is configured to be cooled with a gas turbine. The gas turbine combustor according to claim 1 or 2 ,
A gas turbine combustor comprising turbulent flow promoting ribs on an inner wall surface of the air flow path. The gas turbine combustor according to any one of claims 1 to 3 ,
The fuel flow path for supplying fuel to the fuel injection hole of the second swirler and the air flow path are each an annular flow path, and the air flow path is disposed on the inner periphery of the fuel flow path. A gas turbine combustor. The gas turbine combustor according to any one of claims 1 to 4 ,
The fuel system supplied to the gas nozzle hole of the first swirler and the gas nozzle hole of the second swirler is provided with a flow rate control valve, respectively, and the ignition control and load of the gas turbine are controlled by controlling each flow rate control valve. depending on the conditions, the first, and a gas turbine combustor, characterized by have a control device for controlling the fuel flow ratio to be supplied to the second swirler. The gas turbine combustor of claim 5 .
The gas turbine combustor, wherein the control device controls the fuel flow rate ratio so that a theoretical flame temperature in the first swirler is constant even when a fuel gas heat generation amount fluctuates . The gas turbine combustor according to any one of claims 1 to 5 ,
A gas turbine combustor, wherein an oil nozzle for atomizing a starting liquid fuel is disposed at a radial center portion of the first swirler. A combustion chamber that mixes and burns fuel and air; and a burner that supplies the fuel and air to the combustion chamber to hold a flame. The burner includes a first swirler and an outer periphery of the first swirler. A method of operating a gas turbine combustor having a second swirler disposed at
An inner flame is formed by ejecting fuel and air from the first swirler,
A method for operating a gas turbine combustor, characterized in that fuel heated by the inner peripheral flame from the second swirler is ejected to the downstream side of the inner peripheral flame. The method of operating a gas turbine combustor according to claim 8 ,
A method for operating a gas turbine combustor, wherein air is caused to flow down to the second swirler, heated by the inner peripheral flame, and the heated air is ejected from the first swirler.