JP2013177988A - Gas turbine combustor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable gas turbine combustor that can maintain combustion stability, while preventing soot discharge of the gas turbine combustor, even when liquid fuel is used.SOLUTION: A flow path 26 formed by a protrusion 25, whose cross-sectional area has a minimum value, is provided on a combustion chamber 6 side of a liquid fuel nozzle 12 disposed in the center of a diffusion combustion burner 10, and an air hole for introducing air for combustion to the periphery of the liquid fuel nozzle 12 is provided. An air hole for introducing air for combustion is further provided to the protrusion 25.

Description

  The present invention relates to a gas turbine combustor, and more particularly to a dual fuel-fired gas turbine combustor compatible with both liquid fuel and gas fuel that can reduce dust generation in a multi-burner type gas turbine combustor having a plurality of burners. .

  In the power generation business in recent years, the need to use various fuels such as liquid fuel, which is relatively easy to supply fuel, has been increasing due to tight power demand, and gas turbine power generation equipment that uses a liquid fuel combustor is desired. Yes.

  From the viewpoint of protecting the global environment, environmental regulations such as NOx and dust on exhaust gas from gas turbine combustors are becoming stricter. As a means for satisfying environmental regulations, there is a pre-evaporation premix combustion method in which liquid fuel is premixed with air and then burned. As an example, Patent Document 1 discloses a plurality of premixing units in which a diffusion combustion burner having a hollow conical mixing chamber is arranged in the center and a cylindrical mixing chamber for mixing fuel and combustion air is provided on the outer periphery thereof. A gas turbine combustor with a combustion burner is disclosed.

  The diffusion combustion burner is provided with air holes that swirl the combustion air, and causes high-temperature combustion gas to spread in the outer peripheral direction to act as an ignition source for the premix combustion burner, thereby stabilizing the combustion of the premix combustion burner. Improves sex.

  The premixed combustion burner has a structure in which a liquid fuel nozzle is disposed substantially at the center of the axis, a mixing chamber is provided on the downstream side of the liquid fuel nozzle, and a plurality of rows of cylindrical air holes are provided on the mixing chamber wall. The liquid fuel injected from the liquid fuel nozzle evaporates in the mixing chamber and mixes with air, thereby pre-evaporating premixed combustion, thereby realizing reduction of NOx and dust emission.

JP 2010-236739 A

  In the multi-burner type gas turbine combustor, the fuel supply amount is limited for gas turbines with low fuel supply start-up / acceleration and low load conditions, and fuel is supplied to all burners under load conditions close to the rating. Operation is performed. In particular, under low load conditions where the fuel flow rate is low, fuel is supplied only to the diffusion combustion burner to ensure combustion stability even when the average temperature of the combustion gas is low. However, under conditions where the fuel flow rate is low or conditions where the atomization characteristics of the liquid fuel nozzle are poor, the reaction rate of combustion decreases and the time required for combustion increases. In addition, when the liquid fuel spray angle is narrow, the liquid fuel is not involved in the flow of combustion air, oxygen necessary for combustion is not supplied around the liquid fuel droplets, and the progress of the combustion reaction may be delayed. is there. Further, when the fuel is not supplied to the premixed combustion burner, the combustion gas of the diffusion combustion burner is cooled by the fuel air ejected from the premixed combustion burner, and the combustion reaction tends to become slow. Since these cause dust generation, there is a demand for dust reduction technology particularly under low load conditions.

  An object of the present invention is to provide a highly reliable gas turbine combustor capable of reducing the amount of released dust while maintaining the combustion stability of the gas turbine combustor.

  In order to solve the above-described problems, the present invention provides a liquid fuel nozzle that ejects liquid fuel into a mixing chamber, a conical plate that forms the mixing chamber inside, a combustion chamber that burns fuel flowing from the mixing chamber, A plurality of air holes provided in the conical plate, an air hole for injecting combustion air around the liquid fuel nozzle, a protrusion formed in the conical plate, and a cut formed by the protrusion. And a channel having a local minimum value.

  ADVANTAGE OF THE INVENTION According to this invention, the highly reliable gas turbine combustor which can reduce the discharge | emission amount of soot can be provided, maintaining the combustion stability of a gas turbine combustor.

It is a figure which shows the diffusion combustion burner structure of the gas turbine combustor in Example 1 in connection with this invention (Example 1). BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the structure of the gas turbine combustor in Example 1 in connection with this invention, and the schematic block diagram which shows schematically the whole structure of a gas turbine power plant. It is sectional drawing which shows the structure of the gas turbine combustor in Example 2 in connection with this invention, and the schematic block diagram which shows schematically the whole structure of a gas turbine power plant. It is a figure which shows the flow of the diffusion combustion burner vicinity of Example 2 of the gas turbine combustor concerning this invention.

  Hereinafter, an embodiment of a gas turbine combustor using liquid fuel as a fuel according to the present invention will be described with reference to the drawings.

  The embodiment of the present invention described below has a protrusion for reducing the cross-sectional area of the flow channel from the upstream side on the combustion chamber side at the tip of the liquid fuel nozzle disposed at the center of the diffusion combustion burner. Are provided with air holes for introducing combustion air. And according to the Example of this invention, the gas turbine combustor which reduces the discharge | emission amount of the unburned part discharged | emitted from a combustor gas turbine combustor, especially when using liquid fuel as a fuel can be provided.

  A gas turbine combustor that can use liquid fuel as an example of an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 2 is a cross-sectional view of the configuration of the gas turbine combustor and a configuration diagram of a gas turbine system including the gas turbine combustor. The schematic configuration of the gas turbine system of this embodiment will be described with reference to FIG.

  The gas turbine system shown in this embodiment is a part of a gas turbine power plant that uses liquid fuel as fuel for the gas turbine. The gas turbine power plant mainly generates a combustion gas 400 by mixing the compressor 1 that compresses air to generate high-pressure combustion air 300, and the combustion air 300 introduced from the compressor 1 and fuel. A gas turbine combustor 3 that supplies the combustion gas 400, and a generator 4 that is driven by the rotation of the turbine 2 to generate electric power.

  The gas turbine combustor 3 can supply the liquid fuel 100 as fuel, and can supply the atomized air 350 to atomize and inject the liquid fuel 100. The atomized air 350 is extracted from the compressor 1, cooled by the heat exchanger 30, then pressurized by the atomizing air compressor 31 and supplied to the liquid fuel nozzle 12. In the gas turbine combustor 3, the liquid fuel 100 and the combustion air 300 supplied from the compressor 1 are mixed and burned in the combustion chamber 6 formed in the inner cylinder 7 to generate a high-temperature combustion gas 400. An outer cylinder 5 that houses the inner cylinder 7, a closing plate 9 that covers an end of the outer cylinder 5, and a high-temperature combustion gas 400 that is generated by connecting to the downstream side of the inner cylinder 7 are supplied to the turbine 2. A sealed pressure vessel is constituted by the guiding transition piece 8.

  A diffusion combustion burner 10 with good combustion stability is installed at the axial center position upstream of the inner cylinder 7 provided in the gas turbine combustor 3, and a plurality of premixed combustion burners 11 are arranged around it. The A diffusion burner 10 and a burner cover 21 surrounding the premixed combustion burner 11 are disposed on the outer peripheral side of the premixed combustion burner 11, and the diffusion combustion burner 10 and the premixed combustion burner 11 are disposed at the downstream end of the burner cover 21. Is disposed integrally with the burner cover 21.

  The premix combustion burner 11 provided in the gas turbine combustor 3 is provided with a liquid fuel nozzle 13 for supplying the liquid fuel 100 to the upstream axial center position of the premix combustion burner 11. The liquid fuel 100 injected from the liquid fuel nozzle 13 is jetted into the combustion chamber 6 while being mixed with the combustion air 300 flowing in from the plurality of air holes 16 provided in the wall surface of the premixed combustion burner 11 in the mixing chamber 11a. To do. Since evaporation / mixing of the liquid fuel 100 is promoted in the mixing chamber 11a, combustion with less unburned content becomes possible.

  The diffusion combustion burner 10 has a structure in which a conical plate 10b having a hollow conical shape forming a mixing chamber 10a is installed on the inner side, and the combustion air 300 is ejected to the mixing chamber 10a on the wall surface of the conical plate 10b. A plurality of air holes 15 are provided. A liquid fuel nozzle 12 for injecting the liquid fuel 100 for diffusion combustion is disposed at the axial center position of the diffusion combustion burner 10. The liquid fuel 100 is injected from the center, and the spray air 350 is supplied from the periphery thereof. As a result, the fuel is atomized. The liquid fuel 100 flows into the combustion chamber 6 while being mixed with the combustion air 300 in the mixing chamber 10 a and burns to become a high-temperature combustion gas 400 to drive the turbine 2.

  Next, the fuel supply system and operation method of the gas turbine system provided with the gas turbine combustor of the present invention will be described.

  The liquid fuel 100 stored in the liquid fuel tank 110 is pressurized by a pressurizing pump 101 and supplied from the liquid fuel supply system 120 and the liquid fuel supply system 121 to the diffusion combustion burner 10 and the premixed combustion burner 11 through the closing plate 9. The The fuel flow rate is controlled according to the load of the gas turbine. When the gas turbine is accelerated from the start-up and operated under a low load condition, the liquid fuel 100 is supplied only to the diffusion combustion burner 10. Drive alone. Since the fuel flow rate increases under high load conditions of the gas turbine, the liquid fuel 100 is supplied to the premixed combustion burner 11 in addition to the diffusion combustion burner 10. The ratio of the fuel flow rate between diffusion combustion and premixed combustion is controlled so as to achieve both low NOx and stable combustion.

The structure of the diffusion combustion burner of the gas turbine combustor having the above configuration will be described with reference to FIG.
A two-fluid spray type liquid fuel nozzle 12 for atomizing the liquid fuel 100 with the atomizing air 350 and injecting it into the combustion chamber 6 is disposed at the axial center position of the diffusion combustion burner 10. A plurality of air holes 15 a, 15 b, 15 c, and 15 d are arranged in the circumferential direction in a hollow conical conical plate 10 b installed around the liquid fuel nozzle 12. Combustion air 300 supplied from each air hole is mixed with the liquid fuel 100 injected from the liquid fuel nozzle 12 to become an air-fuel mixture 50 and combusts in the combustion chamber 6.

  Around the tip of the liquid fuel nozzle 12, air holes 15 a are disposed so as to be inclined in the circumferential direction. A protrusion 25 integrated with the conical plate 10b is provided at a downstream position of the liquid fuel nozzle 12, and a flow path 26 having a minimum flow cross-sectional area is formed at the center thereof. The protrusion 25 is provided with an air hole 15b for supplying the combustion air 300 to the flow path 26, and the air hole 15b is inclined in the circumferential direction and the axial direction. The outlet of the flow path 26 is opened to the conical plate 10b, and the cross-sectional area rapidly expands after passing through the flow path 26. The conical plate 10b facing the combustion chamber 6 is provided with air holes 15c and 15d inclined in the circumferential direction and the axial direction.

The flow in the vicinity of the diffusion combustion burner 10 having the above structure and the effects thereof will be described.
The liquid fuel 100 and the atomized air 350 ejected from the liquid fuel nozzle 12 are supplied to the combustion chamber 6 through the flow path 26 and the mixing chamber 10a together with the combustion air 300 supplied from the air holes to become the combustion gas 400.

  In the diffusion combustion burner 10 of the present embodiment, a projection 25 is provided on the conical plate 10b, and a flow path 26 having a minimum cross-sectional area is formed between the liquid fuel nozzle 12 and the mixing chamber 10a. In the flow path 26, a flow that flows down including fine turbulence structures such as a wake vortex generated downstream of the liquid fuel nozzle 12 and a separation vortex caused by contraction of the combustion air 300 at the inlet of the protrusion 25 is formed. The mixture 50 of the liquid fuel 100 and the combustion air 300 ejected into the mixing chamber 10a is rapidly mixed as the vortex limited in the narrow space of the flow path 26 expands and collapses.

  Further, the combustion air 300 supplied from the air holes 15 a inclined in the circumferential direction forms a swirling flow in the vicinity of the liquid fuel nozzle 12. In the flow path 26, the cross-sectional area decreases, and the angular velocity of the mixture 50 of the liquid fuel 100 ejected from the liquid fuel nozzle 12 and the combustion air 300 supplied from the air holes 15a increases. The air-fuel mixture 50 having a large angular velocity spreads rapidly in the outer circumferential direction when the wall is no longer restrained downstream of the flow path 26, and collides with the combustion air 300 flowing in from the air holes 15c and 15d provided in the conical plate 10b. . Due to the collision with the combustion air 300, a shearing force acts on the droplets of the liquid fuel 100 and atomization proceeds. The combustion air 300 flowing from the air holes 15c and 15d diffuses inside the droplet group of the liquid fuel 100 that is rapidly mixed by rapid expansion and atomized by the action of the shearing force by the combustion air 300, so that the oxidation reaction occurs. It is possible to reduce the generation amount of soot that is unburned.

  Another effect of the formation of the protrusion 25 is prevention of a temperature rise of the liquid fuel nozzle 12 due to a decrease in the amount of radiant heat transfer between the liquid fuel nozzle 12 and the flame formed in the combustion chamber 6. Since coke generation in the liquid fuel nozzle 12 due to thermal decomposition can be prevented, a highly reliable combustor with reduced risk of blockage of the fuel supply system can be provided.

  As another effect due to the formation of the protrusion 25, an ejector effect that creates a region where the pressure is lower than the surroundings by increasing the flow velocity in the flow channel 26 where the flow channel cross-sectional area is minimized is generated. The combustion air 300 flowing in from the holes 15a and 15b may be increased. The liquid fuel 100 and the atomized air 350 are ejected from the liquid fuel nozzle 12 into the flow path 26 at a high speed, so that the combustion air 300 supplied around the liquid fuel 100 can be increased. Evaporation / mixing of the liquid fuel 100 is promoted, and the fuel-air ratio is lowered, so that the number of points where the flame temperature rises can be reduced. Therefore, the NOx emission amount can be reduced.

  Next, the effect by providing the air hole 15b in the projection part 25 is demonstrated. By providing the air hole 15b in the protrusion 25, the combustion air 300 flows in so as to cover the surface of the protrusion 25, so that the liquid fuel 100 can be prevented from adhering to the flow path 26 and coke deposition. Note that, by inclining the air holes 15b in the axial direction and the circumferential direction, the effect of preventing the liquid fuel 100 from adhering to the flow path 26 and coke deposition is further improved. Further, since the ejector effect increases with the increase in the flow rate of the liquid fuel 100 and the spray air 350, the flow rate of the combustion air 300 flowing from the air holes 15b also increases. As a result, the combustion air 300 covering the surface of the protrusion 25 also increases, so that the effect of preventing the generation of coke due to the fuel adhering to the wall surface is increased, and the combustion stability due to the reduction in the cross-sectional area of the flow path 26 and the blockage. Therefore, it is possible to prevent the reliability of the gas turbine combustor from being lowered due to the deterioration of the performance.

  In the present embodiment, the cone-shaped spray trajectory formed downstream of the liquid fuel nozzle 12 by the injection of the liquid fuel 100 does not collide with the inner surface of the flow path 26 and the liquid is located farthest from the flow path 26. The tip of the fuel nozzle 12 is disposed. By transmitting the momentum of the liquid fuel 100 injected at high speed to the combustion air 300, the flow velocity of the combustion air 300 passing through the flow path 26 is increased, and an ejector effect is obtained. When the momentum is not sufficiently transmitted, the ejector effect is reduced, so that the liquid fuel nozzle 12 is placed away from the flow path 26 to lengthen the momentum transmission time, and the average flow velocity of the combustion air 300 in the flow path 26. Increases the ejector effect. As a result, the evaporation / mixing time of the liquid fuel 100 is lengthened and promoted, so that the number of local rises in the flame temperature can be reduced and the NOx emission amount can be reduced.

  As described above, in the configuration of the present embodiment, atomization of liquid fuel and mixing of liquid fuel and combustion air are promoted, so that the amount of air pollutants such as dust can be reduced. Moreover, since coke production | generation to the surface of the protrusion part 25 can be prevented, a reliable gas turbine combustor can be provided. Furthermore, it is possible to provide a highly reliable combustor by reducing the possibility that coke is generated at the tip of the liquid fuel nozzle or upstream thereof and fuel cannot be supplied.

  As the flow rate of the liquid fuel increases, the flow rate of the combustion air flowing around the liquid fuel tends to increase, so the combustion temperature tends to decrease, and by promoting the pre-evaporation of the fuel, the local combustion temperature decreases and NOx Increase in emissions can be suppressed.

  In the present embodiment, the description has been given using the two-fluid spray type liquid fuel nozzle using the spray air, but the effect can be expected even if a single fluid nozzle such as a spiral injection valve type is used.

  A dual-fuel compatible gas turbine combustor that can use both liquid fuel and gaseous fuel as an example of an embodiment of the present invention will be described with reference to FIG. The gas turbine power plant of the present embodiment has a configuration in which the gas fuel 200 can be supplied to the gas turbine combustor 3 in addition to the configuration shown in FIG.

  In addition to the liquid fuel supply systems 120 and 121 for supplying the liquid fuel 100 shown in the first embodiment, the fuel supply system of the gas turbine system including the gas turbine combustor according to the present invention uses the gaseous fuel 200 as the gaseous fuel. Gas fuel supply systems 220 and 221 for supplying from the tank 210 are provided. Each system is connected to a closing plate 9, and gaseous fuel 200 is supplied to the diffusion combustion burner 10 and the premixed combustion burner 11.

  The diffusion combustion burner 10 and the premixed combustion burner 11 are provided with a gaseous fuel nozzle 14 and a gaseous fuel injection hole 17 for supplying the gaseous fuel 200 to the mixing chambers 10a and 11a. The gaseous fuel nozzle 14 is disposed at a position close to the upstream side of the air hole 15 provided in the conical plate 10 b of the diffusion combustion burner 10. The gaseous fuel 200 is supplied to the combustion chamber 6 while being mixed with the combustion air 300 in the air holes 15 and in the mixing chamber 10a. The other gaseous fuel injection hole 17 is provided on the wall surface of a plurality of air holes 16 provided in the mixing chamber 11 a on the downstream side of the liquid fuel nozzle 13 provided in the axial center of the premixed combustion burner 11. The gaseous fuel 200 supplied from the gaseous fuel injection hole 17 is supplied to the combustion chamber 6 while being mixed with the combustion air 300 in the air hole 16 and the mixing chamber 11a. As in the case of supplying the liquid fuel 100, the mixture of the gaseous fuel 200 and the combustion air 300 is combusted in the combustion chamber 6 to become a high-temperature combustion gas 400 and drives the turbine 2.

  The structure in the vicinity of the diffusion combustion burner of the gas turbine combustor having the above configuration will be described with reference to FIG.

  Similar to the diffusion combustion burner of the gas turbine combustor shown in the first embodiment, a liquid fuel nozzle 12 of a two-fluid spray system for injecting the liquid fuel 100 into the combustion chamber 6 is provided at the axial center position of the diffusion combustion burner 10. A plurality of air holes 15a, 15b, 15c, and 15d are arranged in the circumferential direction in the surrounding conical plate 10b.

  The air holes 15 a are provided around the tip of the liquid fuel nozzle 12, and combustion air 300 is supplied from the outer periphery of the liquid fuel nozzle 12 toward the nozzle tip. A protrusion 25 integrated with the conical plate 10b is provided at a downstream position of the tip of the liquid fuel nozzle 12, and an air hole 15b for supplying the combustion air 300 to the flow path 26 formed therebetween is a protrusion. 25. The inlet of the air hole 15b is disposed on the wall surface of the air hole 15c provided in the conical plate 10b, and the air hole 15b is formed to communicate with the air hole 15c. Therefore, a part of the combustion air 300 that has flowed into the air hole 15 c is supplied to the flow path 26. Further, a gas fuel nozzle 14 for supplying the gaseous fuel 200 to the air holes 15c and 15d is disposed at a position close to the upstream side of the air holes 15c and 15d, and the gaseous fuel 200 supplied to the fuel header 18 is supplied to the gaseous fuel 200. It is configured so that it can be supplied to the mixing chamber 10a through the air holes 15c and 15d.

  The combustion chamber 6 side of the protrusion 25 has a curved surface shape, and the combustion air 300 flows out while spreading in the outer circumferential direction along the curved surface due to the Coanda effect. The combustion air 300 flowing out from the flow path 26 collides with the gas mixture 200 of the gaseous fuel 200 and the combustion air 300 flowing out from the air holes 15c and 15d and mixes in the mixing chamber 10a. A high-temperature combustion gas 400 is obtained.

  When the gaseous fuel 200 is used, since the gaseous fuel 200 is supplied into the air holes 15c, the combustion air flowing into the air holes 15c increases due to the ejector effect. However, if the flow rate of the gaseous fuel 200 is high, it collides with the side wall surface of the combustion chamber 6 of the air hole 15c and flows out to the mixing chamber 10a along the wall surface in the air hole 15c. Is narrow and difficult to mix. By providing the inlet of the air hole 15b in the air hole 15c, the combustion air 300 flows also to the air hole 15b side, the gaseous fuel 200 is also drawn to the air hole 15b side, and the side wall surface of the combustion chamber 6 of the air hole 15c It becomes difficult to collide with. When the gaseous fuel 200 flows in the vicinity of the center of the air hole 15c, the contact area with the combustion air 300 is increased and mixing is promoted, so that an increase in local combustion temperature can be prevented and NOx emission can be reduced. .

  When the liquid fuel 100 is used in the gas turbine combustor having such a configuration, since the combustion air 300 is supplied from the direction perpendicular to the traveling direction of the liquid fuel 100 in the flow path 26, shear force is applied to the droplets. It is easy to work and can promote atomization of the liquid fuel 100. Similarly, since the air-fuel mixture 50 and the combustion air 300 that collide with the traveling direction on the downstream side of the protrusion 25 are perpendicular to each other, the atomization of the liquid fuel 100 can be promoted. These effects can reduce the generation amount of dust by increasing the combustion speed.

  Moreover, since the exit part of the projection part 25 becomes a curved surface, the stress concentration to the conical plate 10b resulting from the thermal radiation from a flame can be prevented, and the reliability of a gas turbine combustor can be ensured. This effect can also be obtained when a curved surface portion is formed on the combustion chamber side of the protrusion 25 of the first embodiment.

  In the configuration of this embodiment, when liquid fuel is supplied to the diffusion combustion burner of the gas turbine combustor, atomization of the liquid fuel and mixing of the liquid fuel and the combustion air are promoted, so that air pollution such as dust The amount of substances generated can be reduced. Further, it is possible to prevent the coke from being generated due to the tip of the liquid fuel nozzle or upstream thereof, thereby making it impossible to supply fuel, thereby ensuring reliability. Furthermore, even when gaseous fuel is used, it is possible to provide a gas turbine combustor that can reduce NOx emission by promoting mixing of gaseous fuel and combustion air.

  Here, the case where liquid fuel that is likely to generate soot is supplied to the diffusion combustion burner has been described. However, for liquid fuel that is easily vaporized, the flow velocity at the protrusion further increases due to evaporation of the fuel, and the combustion fuel supplied to the protrusion Since the air flow rate increases, it is also effective in reducing the local combustion temperature and reducing NOx emissions.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Turbine 3 Gas turbine combustor 4 Generator 5 Outer cylinder 6 Combustion chamber 7 Inner cylinder 8 Transition piece 9 Closure plate 10 Diffusion combustion burner 10a, 11a Mixing chamber 10b Conical plate 11 Premixed combustion burner 12, 13 Liquid fuel Nozzle 14 Gaseous fuel nozzle 15, 15 a, 15 b, 15 c, 16 Air hole 17 Gaseous fuel injection hole 18 Fuel header 19 Plate 21 Burner cover 25 Protrusion 26 Channel 27 Diffuser 30 Heat exchanger 31 Atomizing air compressor 50, 51 Gas 100, 150 Liquid fuel 101, 151 Pressurization pump 110 Liquid fuel tank 120, 121 Liquid fuel supply system 210 Gas fuel tank 220, 221 Gas fuel supply system 300 Combustion air 350 Spray air 400 Combustion gas

Claims (5)

A liquid fuel nozzle for jetting liquid fuel into the mixing chamber;
A conical plate forming the mixing chamber on the inside;
A combustion chamber for burning fuel flowing in from the mixing chamber;
A gas turbine combustor having a plurality of air holes provided in the conical plate,
An air hole for injecting combustion air around the liquid fuel nozzle;
A protrusion formed on the conical plate,
A gas turbine combustor characterized in that a flow path having a minimum cross-sectional area is formed between the liquid fuel nozzle and the mixing chamber by the protrusion. A gas turbine combustor according to claim 1,
A gas turbine combustor, wherein an air hole for introducing combustion air is provided in the protrusion. A gas turbine combustor according to claim 2,
A gas turbine combustor comprising a gaseous fuel nozzle for supplying gaseous fuel to an air hole provided in the conical plate. A gas turbine combustor according to claim 3,
Air holes provided in the protrusions are
A gas turbine combustor formed so as to communicate with an air hole provided in the conical plate. A gas turbine combustor according to any one of claims 1 to 4,
The gas turbine combustor, wherein the protrusion has a curved surface on the combustion chamber side.