JP5922450B2

JP5922450B2 - Pilot combustion burner, gas turbine combustor and gas turbine

Info

Publication number: JP5922450B2
Application number: JP2012059347A
Authority: JP
Inventors: 中尾　光宏; 光宏中尾; 斉藤　圭司郎; 圭司郎斉藤; 赤松　真児; 真児赤松
Original assignee: Mitsubishi Hitachi Power Systems Ltd
Current assignee: Mitsubishi Power Ltd
Priority date: 2012-03-15
Filing date: 2012-03-15
Publication date: 2016-05-24
Anticipated expiration: 2032-03-15
Also published as: JP2013194928A

Description

本発明は、ガスタービンの燃焼器の軸心に配置されるパイロット燃焼バーナ、このパイロット燃焼バーナを有するガスタービン燃焼器及びこのガスタービン燃焼器が搭載されるガスタービンに関するものである。 The present invention relates to a pilot combustion burner disposed at the center of a combustor of a gas turbine, a gas turbine combustor having the pilot combustion burner, and a gas turbine on which the gas turbine combustor is mounted.

一般的なガスタービンは、圧縮機と燃焼器とタービンとにより構成されている。そして、空気取入口から取り込まれた空気が圧縮機によって圧縮されることで高温・高圧の圧縮空気となり、燃焼器において、この圧縮空気に燃料を供給して燃焼させることで高温・高圧の燃焼ガスを得て、この燃焼ガスによりタービンを駆動させ、このタービンにロータを介して連結された発電機により発電を行う。タービンを駆動した燃焼ガスは、排気車室のディフューザを経由して大気に放出される。 A general gas turbine includes a compressor, a combustor, and a turbine. The air taken in from the air intake is compressed by the compressor to become high-temperature and high-pressure compressed air. In the combustor, fuel is supplied to the compressed air and burned to burn it. The turbine is driven by the combustion gas, and power is generated by a generator connected to the turbine via a rotor. The combustion gas that has driven the turbine is released to the atmosphere via the diffuser in the exhaust casing.

近年、大気放出される燃焼ガスの環境影響を考慮して、燃焼ガスに含まれる窒素酸化物（以下、ＮＯｘ）等の低減が求められている。そのため、ガスタービンの燃焼器にも低ＮＯｘ化の特性が要求されるようになった。これに対し、従来のガスタービンの燃焼器に使用されてきた拡散燃焼方式は、燃焼安定性が高い反面、燃料と酸素とが量論比になる部分に火炎が形成され、火炎温度が断熱火炎温度に近い高温になるため、ＮＯｘの排出濃度が高くなる。そこで、燃焼前に理論空燃比よりも空気の量が過剰な混合ガスを作り、それを燃焼するという希薄予混合燃焼方式が提案された。この方式は火炎温度を抑えた燃焼が可能となるため、低ＮＯｘ化に対して優れている。しかし、希薄混合ガスは燃料濃度が低過ぎるので、火炎を保持することが困難である。 In recent years, in consideration of the environmental influence of combustion gas released into the atmosphere, reduction of nitrogen oxide (hereinafter referred to as NOx) contained in the combustion gas has been demanded. For this reason, the characteristics of NOx reduction are also required for the combustor of the gas turbine. In contrast, the diffusion combustion method that has been used in conventional gas turbine combustors has high combustion stability, but a flame is formed in the stoichiometric ratio of fuel and oxygen, and the flame temperature is adiabatic flame. Since the temperature is close to the temperature, the NOx emission concentration increases. Therefore, a lean premixed combustion method has been proposed in which a mixed gas whose amount of air is larger than the stoichiometric air-fuel ratio before combustion is burned. Since this method enables combustion while suppressing the flame temperature, it is excellent for reducing NOx. However, since the lean gas mixture has a fuel concentration that is too low, it is difficult to hold the flame.

そこで、例えば、特許文献１に記載されているように、混合ガスとは別個にパイロット燃焼バーナを使用し、メインの予混合燃焼バーナとは別の高温の燃焼ガスを作り、そのガスを主燃焼器の希薄混合ガスに吹き込んで安定的に燃焼を行う燃焼器が提案された。 Therefore, for example, as described in Patent Document 1, a pilot combustion burner is used separately from the mixed gas, a high-temperature combustion gas different from the main premixed combustion burner is created, and the gas is burned into the main combustion. A combustor has been proposed for stable combustion by blowing into a lean gas mixture.

しかし、特許文献１のパイロット燃焼バーナは拡散燃焼を行うため、可燃範囲が広く火炎は安定するが、燃焼時に局所的な高温部が発生するので、更なる低ＮＯｘ化のためには限界がある。 However, since the pilot combustion burner of Patent Document 1 performs diffusion combustion, the flammable range is wide and the flame is stable, but a local high temperature portion is generated during combustion, so there is a limit to further reducing NOx. .

そこで特許文献２に記載されているように、パイロット燃焼バーナにおいても拡散燃焼方式と予混合燃焼方式を併用することが検討された。この技術では、燃焼が不安定な起動時には拡散燃焼を行い、ガスタービンが所定の負荷に達したら予混合燃焼に切り替えることにより、起動時における吹き消えを防止することができるとともに、低ＮＯｘ化を実現する効果を狙ったものである。 Therefore, as described in Patent Document 2, it has been studied to use the diffusion combustion method and the premixed combustion method in the pilot combustion burner. With this technology, diffusion combustion is performed at startup when combustion is unstable, and switching to premixed combustion when the gas turbine reaches a predetermined load can prevent blow-off at startup and reduce NOx. It aims at the effect to be realized.

特開２００４−１０１０８１号公報JP 2004-101081 A 特開２０１０−２４９４４９号公報JP 2010-249449 A

しかしながら、ガスタービン起動から定格運転に合わせて、パイロット燃焼バーナの燃焼方式を拡散燃焼方式から予混合燃焼方式に切り替え、さらに、更なる低ＮＯｘ化のため、予混合パイロット燃焼バーナにおける燃料の比率（パイロット比率）を下げていくと、燃焼器内に燃焼振動が発生する場合がある。 However, in accordance with the rated operation from the start of the gas turbine, the combustion method of the pilot combustion burner is switched from the diffusion combustion method to the premixed combustion method, and in order to further reduce NOx, the fuel ratio in the premixed pilot combustion burner ( If the pilot ratio is decreased, combustion vibration may occur in the combustor.

パイロット比率を下げていくとパイロット混合ガスの燃焼温度が下がり、また、燃焼速度が遅くなるために、低温燃焼域になった火炎長が長くなっていく。つまり、パイロット比率が高い間はメイン燃焼バーナの混合ガスへは高温の既燃ガスが到達していたのに対し、パイロット比率を下げていくと未燃予混合ガスが到達するようになり、その結果、メイン燃焼バーナの保炎器部に対して、既燃ガスと未燃ガスとが不規則な影響を与えるため、燃焼安定性が損なわれ、燃焼振動が発生する。 When the pilot ratio is lowered, the combustion temperature of the pilot mixed gas is lowered and the combustion speed is slowed down, so that the flame length in the low-temperature combustion zone becomes long. In other words, while the pilot ratio was high, high-temperature burned gas reached the mixed gas of the main combustion burner, but when the pilot ratio was lowered, unburned premixed gas arrived. As a result, the burned gas and the unburned gas have an irregular effect on the flame holder portion of the main combustion burner, so that the combustion stability is impaired and combustion vibration occurs.

本発明は、上記に鑑みてなされたものであって、燃焼振動を抑制することで安定燃焼を行うとともにＮＯｘの発生量を抑制することができるパイロット燃焼バーナ、ガスタービン燃焼器及びガスタービンを提供することを目的とする。 The present invention has been made in view of the above, and provides a pilot combustion burner, a gas turbine combustor, and a gas turbine capable of performing stable combustion by suppressing combustion vibration and suppressing the amount of NOx generated. The purpose is to do.

上記の問題点に対し本発明は、以下の各手段を以って課題の解決を図る。 In order to solve the above problems, the present invention aims to solve the problems by the following means.

第１の発明のパイロット燃焼バーナは、ガスタービンの燃焼器の軸心に配置されるパイロット燃焼バーナであって、前記パイロット燃焼バーナの先端部分に設置した保炎器の任意半径位置において、前記保炎器の周方向に一定の間隔で孔を並べて貫通させ、圧縮機から送られた圧縮空気を前記孔に流入させるとともに、前記圧縮空気の流れ方向において、燃料噴射口の位置を前記孔の上流側または内部に設けることで、燃料と前記圧縮空気とを混合して前記孔から噴出する予混合パイロットノズルと、前記保炎器上において、前記孔と別の位置に設けた燃料噴射口から燃料を噴射することで拡散燃焼を行う拡散パイロットノズルと、を備えることを特徴とする。 A pilot combustion burner according to a first aspect of the present invention is a pilot combustion burner disposed at the axial center of a combustor of a gas turbine, and is arranged at an arbitrary radial position of a flame holder installed at a tip portion of the pilot combustion burner. Holes are lined up and arranged at regular intervals in the circumferential direction of the flame unit, and compressed air sent from the compressor flows into the holes, and the position of the fuel injection port in the flow direction of the compressed air is set upstream of the holes. A premix pilot nozzle that mixes fuel and the compressed air and ejects the fuel from the hole, and a fuel injection port provided at a position different from the hole on the flame holder. And a diffusion pilot nozzle that performs diffusion combustion by injecting.

第２の発明のパイロット燃焼バーナは、上述したパイロット燃焼バーナにおいて、前記予混合パイロットノズルは、前記孔を設けた前記保炎器の半径位置における円周の接線方向に沿うように、前記孔を貫通させることで、前記燃料と前記圧縮空気とを含むパイロット混合ガスを周方向に旋回させること、を特徴とする。 A pilot combustion burner according to a second aspect of the present invention is the pilot combustion burner described above, wherein the premixed pilot nozzle has the hole formed along a circumferential tangential direction at a radial position of the flame holder provided with the hole. By making it penetrate, the pilot mixed gas containing the fuel and the compressed air is swirled in the circumferential direction.

第３の発明のパイロット燃焼バーナは、上述したパイロット燃焼バーナにおいて、前記予混合パイロットノズルは、前記保炎器の半径方向外側に向って前記孔を貫通させ、前記燃料と前記圧縮空気とを含むパイロット混合ガスを半径方向外側に噴出させること、を特徴とする。 A pilot combustion burner according to a third aspect of the present invention is the pilot combustion burner described above, wherein the premix pilot nozzle passes through the hole toward the radially outer side of the flame holder and includes the fuel and the compressed air. The pilot mixed gas is ejected radially outward.

第４の発明のパイロット燃焼バーナは、上述したパイロット燃焼バーナにおいて、前記メイン燃焼バーナの延長管出口位置と保炎器の位置関係に関し、前記燃焼器の軸心を通り燃焼器尾筒に向う直線に直交する方向で見たときに、前記保炎器の位置を前記延長管出口の位置よりも上流に設置するとともに、前記保炎器の外周上、かつ前記メイン燃焼バーナの前記延長管の内側部分に、周方向に連続しているコーン部材を配置したこと、または前記保炎器の外周上でかつ前記メイン燃焼バーナの前記延長管の内側部分に前記延長管の周方向位置と略一致させて複数の板を配置したこと、を特徴とする。 A pilot combustion burner according to a fourth aspect of the present invention relates to the pilot combustion burner described above, and relates to the positional relationship between the extension tube outlet position of the main combustion burner and the flame holder, and is a straight line passing through the combustor axis and toward the combustor tail cylinder. When installed in a direction orthogonal to the flame holder, the flame holder is positioned upstream of the extension pipe outlet, and on the outer circumference of the flame holder and inside the extension pipe of the main combustion burner. A cone member that is continuous in the circumferential direction is disposed in the portion, or is substantially aligned with the circumferential position of the extension tube on the outer periphery of the flame holder and on the inner portion of the extension tube of the main combustion burner. And a plurality of plates are arranged.

第５の発明のパイロット燃焼バーナは、上述したパイロット燃焼バーナにおいて、前記パイロットノズルに接続している燃料流路が、前記燃料流路内の燃料供給方向において、前記保炎器の上流に位置するキャビティに接続し、前記キャビティには、外径が前記キャビティよりも大きく、前記燃料流路内の燃料供給方向において、その下流側を覆って蓋をする多孔板を設置するとともに、前記多孔板には複数の孔を設けて、前記孔から燃料を噴射できるようにし、前記多孔板は、前記圧縮空気の流入方向でみて前記保炎器より上流側に位置し、かつ前記多孔板と前記保炎器との間には所定の隙間を設けるように設置し、前記多孔板の周方向の孔位置を燃料噴射方向の下流に位置する前記保炎器の孔位置と一致する構成としたことで、前記多孔板と前記保炎器との隙間に前記圧縮空気が流入し、前記多孔板の孔位置から噴出した前記燃料と前記圧縮空気とを混合して噴出する予混合パイロットノズルを備えること、を特徴とする。 A pilot combustion burner according to a fifth aspect of the present invention is the pilot combustion burner described above, wherein the fuel flow path connected to the pilot nozzle is located upstream of the flame holder in the fuel supply direction in the fuel flow path. A perforated plate connected to the cavity and having an outer diameter larger than that of the cavity and covering the downstream side in the fuel supply direction in the fuel flow path and covering the downstream side is installed in the cavity plate. Is provided with a plurality of holes so that fuel can be injected from the holes, and the perforated plate is located upstream of the flame holder in the inflow direction of the compressed air, and the perforated plate and the flame holding member It was installed so as to provide a predetermined gap between the container and the hole position in the circumferential direction of the perforated plate and the hole position of the flame holder located downstream in the fuel injection direction, Porous And a premix pilot nozzle that mixes and ejects the fuel and the compressed air that are injected from the hole position of the perforated plate and flows into the gap between the flame holder and the flame holder. .

第６発明のガスタービン燃焼器は、圧縮空気と燃料とが内部で燃焼して燃焼ガスを発生させる燃焼筒と、前記燃焼筒内における軸心に配置されるパイロット燃焼バーナと、前記燃焼筒内における前記パイロット燃焼バーナを取り囲むように配置される複数のメイン燃焼バーナと、を備えるガスタービン燃焼器において、前記パイロット燃焼バーナの先端部分に設置した保炎器の任意半径位置において、前記保炎器の周方向に一定の間隔で孔を並べて貫通させ、圧縮機から送られた圧縮空気を前記孔に流入させるとともに、前記圧縮空気の流れ方向において、燃料噴射口の位置を前記孔の上流側に設けることで、燃料と前記圧縮空気とを混合して前記孔から噴出する予混合パイロットノズルと、前記保炎器上において、前記孔と別の位置に設けた燃料噴射口から燃料を噴射することで拡散燃焼を行う拡散パイロットノズルと、を備えることを特徴とする。 A gas turbine combustor according to a sixth aspect of the present invention includes a combustion cylinder in which compressed air and fuel are combusted to generate combustion gas, a pilot combustion burner disposed at an axial center in the combustion cylinder, and the combustion cylinder A gas turbine combustor comprising a plurality of main combustion burners arranged so as to surround the pilot combustion burner in the above, and at the arbitrary radial position of the flame stabilizer installed at the tip portion of the pilot combustion burner The holes are lined up and penetrated at regular intervals in the circumferential direction, and the compressed air sent from the compressor flows into the holes, and the position of the fuel injection port is located upstream of the holes in the flow direction of the compressed air. A premix pilot nozzle that mixes the fuel and the compressed air and ejects it from the hole, and is provided at a position different from the hole on the flame holder. Characterized in that it comprises a diffusion pilot nozzle performing diffusion combustion by injecting fuel from the fuel injection port, a.

第７発明のガスタービンは、圧縮機で圧縮した圧縮空気に燃焼器で燃料を供給して燃焼し、発生した燃焼ガスをタービンに供給することで回転動力を得るガスタービンにおいて、前記燃焼器は、高圧空気と燃料とが内部で燃焼して燃焼ガスを発生させる燃焼筒と、該燃焼筒内における中央部に配置されるパイロット燃焼バーナと、前記燃焼筒内における前記パイロット燃焼バーナを取り囲むように配置される複数のメイン燃焼バーナを有し、前記パイロット燃焼バーナの先端部分に設置した保炎器の任意半径位置において、前記保炎器の周方向に一定の間隔で孔を並べて貫通させ、圧縮機から送られた圧縮空気を前記孔に流入させるとともに、前記圧縮空気の流れ方向において、燃料噴射口の位置を前記孔の上流側に設けることで、燃料と前記圧縮空気とを混合して前記孔から噴出する予混合パイロットノズルと、前記保炎器上において、前記孔と別の位置に設けた燃料噴射口から燃料を噴射することで拡散燃焼を行う拡散パイロットノズルと、を備えることを特徴とする。 A gas turbine according to a seventh aspect of the present invention is a gas turbine which obtains rotational power by supplying fuel to compressed air compressed by a compressor by a combustor and supplying the generated combustion gas to the turbine. A high-pressure air and fuel are combusted inside to generate a combustion gas, a pilot combustion burner disposed in the center of the combustion cylinder, and the pilot combustion burner in the combustion cylinder A plurality of main combustion burners are arranged, and at an arbitrary radial position of the flame holder installed at the tip portion of the pilot combustion burner, holes are arranged at regular intervals in the circumferential direction of the flame holder and compressed. The compressed air sent from the machine flows into the hole, and the fuel injection port is positioned upstream of the hole in the flow direction of the compressed air. A premix pilot nozzle that mixes with compressed air and jets out of the hole, and a diffusion pilot that performs diffusion combustion by injecting fuel from a fuel injection port provided at a position different from the hole on the flame holder And a nozzle.

上述した第１の発明のパイロット燃焼バーナ、第６発明のガスタービン燃焼器及び第７発明のガスタービンの構成によると、周方向に複数配置した予混合パイロットノズルから噴出したパイロット混合ガスは周方向に分割されている。そして、予混合パイロットノズルの周方向の位置と拡散パイロットノズルの周方向の位置がずれているので、拡散パイロットノズルからの燃焼ガスは、パイロット混合ガスの切れ目をすり抜けてメイン燃焼バーナの延長管出口まで到達しやすくなることでメイン燃焼バーナからの希薄予混合燃料の保炎性が増し燃焼が安定するので、燃焼振動を抑制する効果が得られる。 According to the configuration of the pilot combustion burner of the first invention, the gas turbine combustor of the sixth invention, and the gas turbine of the seventh invention described above, the pilot mixed gas ejected from a plurality of premixed pilot nozzles arranged in the circumferential direction is circumferential. It is divided into Since the circumferential position of the premix pilot nozzle and the circumferential position of the diffusion pilot nozzle are misaligned, the combustion gas from the diffusion pilot nozzle passes through the break of the pilot mixture gas and exits from the extension pipe of the main combustion burner. Since the flame holding property of the lean premixed fuel from the main combustion burner is increased and the combustion is stabilized, an effect of suppressing combustion vibration can be obtained.

また、メイン燃焼バーナから噴出した燃焼ガスは燃焼器尾筒内で循環し、高温の既燃ガスの循環流になるが、この高温の既燃ガスの循環流が予混合パイロットノズルから噴出したパイロット混合ガスの間を抜けてメイン燃焼バーナの延長管出口まで到達し、予混合パイロットの濃度と関係なくメイン燃焼バーナからの希薄予混合燃料の保炎性が増し、燃焼が安定するので、燃焼振動を抑制する効果が得られる。 In addition, the combustion gas ejected from the main combustion burner circulates in the combustor tail cylinder and becomes a circulating flow of high-temperature burned gas. The circulating flow of this high-temperature burned gas is injected from the premixed pilot nozzle. Combustion oscillations because it passes through the mixed gas and reaches the extension pipe outlet of the main combustion burner, and the flame holding property of the lean premixed fuel from the main combustion burner increases and the combustion becomes stable regardless of the concentration of the premix pilot. The effect which suppresses is acquired.

以上により、ガスタービン起動から定格運転に合わせて、パイロット燃焼バーナでの燃焼方式を拡散燃焼方式から予混合燃焼方式に切り替え、さらに、更なる低ＮＯｘ化のためパイロット比率を低く運転することでパイロット燃焼ガスが低温になった場合でも、メイン燃焼バーナの燃焼を安定させ、燃焼振動を抑制することができ、低ＮＯｘ化を実現することができるという効果が得られる。 As described above, the pilot combustion burner is switched from the diffusion combustion method to the premixed combustion method in accordance with the rated operation from the start of the gas turbine, and the pilot ratio is operated by lowering the pilot ratio for further NOx reduction. Even when the temperature of the combustion gas becomes low, the combustion of the main combustion burner can be stabilized, the combustion vibration can be suppressed, and the effect of reducing NOx can be obtained.

上述した第２の発明のパイロット燃焼バーナの構成により、パイロット混合ガスは旋回流となり、遠心力によって外周方向に広がるので、予混合パイロットノズルの前方を通過するメイン既燃ガスの循環流と衝突しにくくなる。このため、パイロット比率を低く運転することで低温になったパイロット燃焼ガスが、高温のメイン既燃ガスの循環流に衝突を抑制できる。これにより、既燃ガスの循環流による、メイン燃焼バーナからの希薄予混合燃料の保炎を高めることができる。 With the configuration of the pilot combustion burner of the second invention described above, the pilot mixed gas becomes a swirling flow and spreads in the outer circumferential direction by centrifugal force, so that it collides with the circulating flow of the main burned gas passing in front of the premixed pilot nozzle. It becomes difficult. For this reason, the pilot combustion gas which became low temperature by driving | running a pilot ratio low can suppress a collision with the circulation flow of high temperature main burned gas. Thereby, the flame holding of the lean premixed fuel from the main combustion burner due to the circulating flow of burned gas can be enhanced.

上述した第３の発明のパイロット燃焼バーナの構成により、パイロット混合ガスを外周方向に広げて放出することができるので、第２の実施の形態のパイロット燃焼バーナと同様の効果が得られる。 With the configuration of the pilot combustion burner of the third invention described above, the pilot mixed gas can be released while being expanded in the outer peripheral direction, so the same effect as the pilot combustion burner of the second embodiment can be obtained.

上述した第４の発明の形態のパイロット燃焼バーナの構成により、保炎器の位置をメイン燃焼バーナの延長管出口位置より上流に所定の距離で離して設置し、かつ保炎器の外縁にコーン部材を設置したことにより、燃焼器尾筒内を循環してきた高温のメイン既燃ガスは保炎器とメイン燃焼バーナの間にできた空間内に広がって、その後、保炎器外縁に設置したコーン部材に沿って流れる。これにより、メイン燃焼バーナの延長管出口付近では、メイン燃焼バーナの延長管出口から噴出された希薄予混合燃料と上記の高温の既燃ガスが略平行に合流するようになる。これにより、合流付近での流れの乱れが小さくなり、それによりメイン燃焼バーナの混合ガスの燃焼速度は低下して、その火炎が長く延びる。なお、保炎器外縁上でかつメイン燃焼バーナの延長管の内側部分に延長管の周方向位置と略一致させて複数の板を配置しても、コーン部材を配置したのと略同様の効果を得ることができる。 With the configuration of the pilot combustion burner according to the fourth aspect of the invention described above, the flame holder is installed at a predetermined distance upstream from the outlet position of the extension pipe of the main combustion burner, and a cone is provided at the outer edge of the flame holder. By installing the members, the high-temperature main burned gas that circulated in the combustor tail tube spreads into the space formed between the flame holder and the main combustion burner, and then installed on the outer edge of the flame holder. It flows along the cone member. As a result, in the vicinity of the extension pipe outlet of the main combustion burner, the lean premixed fuel ejected from the extension pipe outlet of the main combustion burner and the above-mentioned high-temperature burned gas come to join approximately in parallel. Thereby, the turbulence of the flow in the vicinity of the merging is reduced, whereby the combustion speed of the mixed gas in the main combustion burner is lowered and the flame is extended for a long time. Even if a plurality of plates are arranged on the outer edge of the flame holder and on the inner part of the extension pipe of the main combustion burner so as to substantially coincide with the circumferential position of the extension pipe, the effect is almost the same as that of the cone member. Can be obtained.

メイン燃焼バーナの延長管出口付近では燃料と圧縮空気の均一な混合が進んでいる途中であり、ここ付近での流れの乱れが大きいと、燃料と圧縮空気が完全に予混合できる前に燃焼が完了してしまう可能性がある。そのため、第４の実施の形態のパイロット燃焼バーナにより、メイン燃焼バーナの延長管出口付近でのメイン燃焼バーナからの希薄予混合燃料と高温の既燃ガスの循環流の合流角度を小さくし略平行にすることで、メイン燃焼ガスの予混合を促進する効果が得られる。これにより、メイン燃焼バーナからの希薄予混合燃料の保炎を高めることで燃焼を安定させる効果に加え、メイン燃焼バーナの燃焼における低ＮＯｘ化を実現することができるという効果が得られる。 Near the outlet of the main combustion burner extension pipe, the fuel and compressed air are being mixed uniformly. If there is a large turbulence in the vicinity of the main combustion burner, combustion will occur before the fuel and compressed air can be completely premixed. May be completed. Therefore, the pilot combustion burner according to the fourth embodiment reduces the merging angle of the circulation flow of the lean premixed fuel from the main combustion burner and the high-temperature burned gas in the vicinity of the extension pipe outlet of the main combustion burner to be substantially parallel. By doing, the effect which accelerates | stimulates the premixing of main combustion gas is acquired. Thereby, in addition to the effect of stabilizing combustion by increasing the flame holding of the lean premixed fuel from the main combustion burner, the effect of achieving low NOx in the combustion of the main combustion burner is obtained.

上述した第５の発明の形態のパイロット燃焼バーナの構成によると、予混合パイロットノズルの燃料流路を通って送られた燃料は、燃料通路に接続したキャビティを経由して多孔板の孔部から噴出し、多孔板と保炎器の隙間に沿って流れ込んできた圧縮空気と混合され、保炎器の基盤部分に設けた孔から圧縮空気と燃料の予混合ガスとして噴出される。 According to the configuration of the pilot combustion burner of the fifth aspect of the invention described above, the fuel sent through the fuel flow path of the premixed pilot nozzle passes through the cavity of the perforated plate via the cavity connected to the fuel passage. It is jetted and mixed with compressed air that has flown along the gap between the perforated plate and the flame holder, and is jetted as a premixed gas of compressed air and fuel from a hole provided in the base portion of the flame holder.

さらに、多孔板と保炎器の隙間に沿って圧縮空気が流れるので、火炎に曝され加熱された保炎器の冷却効果を高めることができる。これにより、メイン燃焼バーナからの希薄予混合燃料の保炎を高めることで燃焼を安定させる効果に加え、炎器の冷却効果を高める効果が得られる。 Furthermore, since the compressed air flows along the gap between the perforated plate and the flame holder, the cooling effect of the flame holder that has been exposed to the flame and heated can be enhanced. Thereby, in addition to the effect which stabilizes combustion by raising the flame holding of the lean premixed fuel from a main combustion burner, the effect which raises the cooling effect of a flame retardant is acquired.

図１は、本発明の第１の実施の形態に係るガスタービンを表す概略構成図である。FIG. 1 is a schematic configuration diagram illustrating a gas turbine according to a first embodiment of the present invention. 図２は、本発明の第１の実施の形態に係るガスタービン燃焼器を表す概略構成図である。FIG. 2 is a schematic configuration diagram showing the gas turbine combustor according to the first embodiment of the present invention. 図３−１は、本発明の第１の実施の形態に係るパイロット燃焼バーナの要部を拡大して示した断面図である。FIG. 3A is an enlarged cross-sectional view of a main part of the pilot combustion burner according to the first embodiment of the present invention. 図３−２は、本発明の第１の実施の形態に係るパイロット燃焼バーナをパイロット混合ガスが噴射された側からみた平面図である。FIG. 3-2 is a plan view of the pilot combustion burner according to the first embodiment of the present invention as viewed from the side where the pilot mixed gas is injected. 図４−１は、本発明の第２の実施の形態に係るパイロット燃焼バーナの要部を拡大して示した断面図である。FIG. 4A is an enlarged cross-sectional view of a main part of a pilot combustion burner according to a second embodiment of the present invention. 図４−２は、本発明の第２の実施の形態に係るパイロット燃焼バーナをパイロット混合ガスが噴射された側からみた平面図である。FIG. 4-2 is a plan view of the pilot combustion burner according to the second embodiment of the present invention as viewed from the side where the pilot mixed gas is injected. 図５−１は、本発明の第３の実施の形態に係るパイロット燃焼バーナの要部を拡大して示した断面図である。FIG. 5-1 is an enlarged cross-sectional view of a main part of a pilot combustion burner according to a third embodiment of the present invention. 図５−２は、本発明の第３の実施の形態に係るパイロット燃焼バーナをパイロット混合ガスが噴射された側からみた平面図である。FIG. 5-2 is a plan view of the pilot combustion burner according to the third embodiment of the present invention as viewed from the side where the pilot mixed gas is injected. 図６−１は、本発明の第４の実施の形態に係るパイロット燃焼バーナにおいて、延長管内側に配置されるコーン部材を設けた保炎器の要部を拡大して示した断面図である。FIG. 6-1 is an enlarged cross-sectional view of a main part of a flame holder provided with a cone member disposed inside an extension pipe in a pilot combustion burner according to a fourth embodiment of the present invention. . 図６−２は、本発明の第４の実施の形態に係るパイロット燃焼バーナにおいて、延長管内側に配置されるコーン部材を取り付けた保炎器をパイロット混合ガスが噴射された側からみた平面図である。FIG. 6-2 is a plan view of a flame holder equipped with a cone member arranged inside the extension pipe as viewed from the side where the pilot mixed gas is injected, in a pilot combustion burner according to a fourth embodiment of the present invention. It is. 図６−３は、本発明の第４の実施の形態に係るパイロット燃焼バーナにおいて、延長管内側に配置される複数の板を取り付けた保炎器の要部を拡大して示した断面図である。FIG. 6-3 is an enlarged cross-sectional view of the main part of the flame holder attached with a plurality of plates arranged inside the extension pipe in the pilot combustion burner according to the fourth embodiment of the present invention. is there. 図６−４は、本発明の第４の実施の形態に係るパイロット燃焼バーナにおいて、延長管内側に配置される複数の板を取り付けた保炎器をパイロット混合ガスが噴射された側からみた平面図である。FIG. 6-4 is a plan view of a flame holder equipped with a plurality of plates arranged inside the extension pipe, as viewed from the side where the pilot mixed gas is injected, in a pilot combustion burner according to a fourth embodiment of the present invention. FIG. 図７−１は、本発明の第５の実施の形態に係るパイロット燃焼バーナの要部を拡大して示した断面図である。FIG. 7-1 is an enlarged cross-sectional view of a main part of a pilot combustion burner according to a fifth embodiment of the present invention. 図７−２は、本発明の第５の実施の形態に係るパイロット燃焼バーナを構成する多孔板ノズルを示す概略構成図である。FIG. 7-2 is a schematic configuration diagram showing a perforated plate nozzle constituting a pilot combustion burner according to a fifth embodiment of the present invention.

以下に、本発明に係るガスタービンの燃焼器の軸心に配置されるパイロット燃焼バーナ、このパイロットノズルを有するガスタービン燃焼器、このガスタービン燃焼器が搭載されるガスタービンの好適な実施形態を図面に基づいて詳細に説明する。なお、この実施形態によりこの発明が限定されるものではない。 Hereinafter, preferred embodiments of a pilot combustion burner arranged at the center of a combustor of a gas turbine according to the present invention, a gas turbine combustor having the pilot nozzle, and a gas turbine on which the gas turbine combustor is mounted will be described. This will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment.

（第１の実施の形態）
第１の実施の形態のガスタービンは、図１に示すように、圧縮機２７と燃焼器２とタービン２８により構成され、さらに図示しない発電機がガスタービンに連結されており、発電可能となっている。 (First embodiment)
As shown in FIG. 1, the gas turbine according to the first embodiment is composed of a compressor 27, a combustor 2, and a turbine 28. Further, a generator (not shown) is connected to the gas turbine so that power generation is possible. ing.

圧縮機２７は空気取入口２９を有し、圧縮機車室３０内に入口案内翼（ＩＧＶ：Inlet Guide Vane）３１が設置されるとともに、複数の静翼３２と動翼３３とが前後方向（後述するロータ３４の軸方向）に交互に設置され、その外側には抽気室３５が設けられている。燃焼器２は、圧縮機２７で圧縮された圧縮空気３に対して燃料４を供給し点火することで燃焼を行う。タービン２８はタービン車室３６内に複数の静翼３７と動翼３８とが前後方向（後述するロータ３４の軸方向）に交互に設置されている。このタービン車室３６の下流側には、排気車室３９を介して排気室４０が設置されており、排気室４０はタービン２８に連続する排気ディフューザ４１を有する。 The compressor 27 has an air intake 29, an inlet guide vane (IGV) 31 is installed in the compressor casing 30, and a plurality of stationary blades 32 and moving blades 33 are arranged in the front-rear direction (described later). Are arranged alternately in the axial direction of the rotor 34), and bleed chambers 35 are provided on the outside thereof. The combustor 2 performs combustion by supplying fuel 4 to the compressed air 3 compressed by the compressor 27 and igniting it. In the turbine 28, a plurality of stationary blades 37 and moving blades 38 are alternately installed in the turbine casing 36 in the front-rear direction (the axial direction of the rotor 34 described later). An exhaust chamber 40 is installed on the downstream side of the turbine casing 36 via an exhaust casing 39, and the exhaust chamber 40 has an exhaust diffuser 41 continuous with the turbine 28.

また、圧縮機２７、燃焼器２、タービン２８、排気室４０の中心部をロータ（回転軸）３４が貫通している。ロータ３４は、圧縮機２７側の端部が軸受部４２により回転自在に支持され、排気室４０側の端部が軸受部４３により回転自在に支持されている。そして、このロータ３４は、圧縮機２７で、各動翼３３が装着されたディスクが複数重ねられて固定され、タービン２８で、各動翼３８が装着されたディスクが複数重ねられて固定されており、排気室４０側の端部に図示しない発電機の駆動軸が連結されている。 A rotor (rotating shaft) 34 passes through the center of the compressor 27, the combustor 2, the turbine 28, and the exhaust chamber 40. The end of the rotor 34 on the compressor 27 side is rotatably supported by the bearing portion 42, and the end of the exhaust chamber 40 side is rotatably supported by the bearing portion 43. The rotor 34 is fixed by a compressor 27 in which a plurality of disks, each having a blade 33 mounted thereon, are stacked and fixed by a turbine 28, and a plurality of disks, each having a blade 38 mounted thereon, are fixed. A generator drive shaft (not shown) is connected to the end portion on the exhaust chamber 40 side.

そして、このガスタービンは、圧縮機２７の圧縮機車室３０が脚部４４に支持され、タービン２８のタービン車室３６が脚部４５により支持され、排気室４０が脚部４６により支持されている。 In this gas turbine, the compressor casing 30 of the compressor 27 is supported by the legs 44, the turbine casing 36 of the turbine 28 is supported by the legs 45, and the exhaust chamber 40 is supported by the legs 46. .

従って、圧縮機２７の空気取入口２９から取り込まれた圧縮空気が、入口案内翼３１、複数の静翼３２と動翼３３を通過して圧縮されることで高温・高圧の圧縮空気３となる。燃焼器２で、この圧縮空気３に対して所定の燃料４が供給され、燃焼する。そして、この燃焼器２で生成された高温・高圧の燃焼ガスが、タービン２８を構成する複数の静翼３７と動翼３８を通過することでロータ３４を駆動回転し、このロータ３４に連結された発電機を駆動する。一方、排気ガス（燃焼ガス）のエネルギは、排気室４０の排気ディフューザ４１により圧力に変換され減速されてから大気に放出される。 Therefore, the compressed air taken in from the air intake port 29 of the compressor 27 passes through the inlet guide vane 31, the plurality of stationary vanes 32, and the moving blades 33 and is compressed to become high-temperature / high-pressure compressed air 3. . In the combustor 2, a predetermined fuel 4 is supplied to the compressed air 3 and burned. The high-temperature and high-pressure combustion gas generated in the combustor 2 drives and rotates the rotor 34 by passing through the plurality of stationary blades 37 and the moving blades 38 constituting the turbine 28, and is connected to the rotor 34. Drive the generator. On the other hand, the energy of the exhaust gas (combustion gas) is converted into pressure by the exhaust diffuser 41 in the exhaust chamber 40 and decelerated before being released to the atmosphere.

図２に示すように、上述した燃焼器２の中心に位置してパイロット燃焼バーナ１が配置されるとともに、燃焼器２の内周面に周方向に沿ってパイロット燃焼バーナ１を取り囲むように複数のメイン燃焼バーナ６が配置されている。 As shown in FIG. 2, the pilot combustion burner 1 is disposed at the center of the combustor 2 described above, and a plurality of pilot combustion burners 1 are surrounded on the inner peripheral surface of the combustor 2 along the circumferential direction. The main combustion burner 6 is arranged.

また、図示しないパイロット燃料ラインがパイロット燃焼バーナの燃料流路６２、６３に連結され、図示しないメイン燃焼ラインが各メイン燃焼ノズルの燃料流路１５に連結されている。 A pilot fuel line (not shown) is connected to the fuel passages 62 and 63 of the pilot combustion burner, and a main combustion line (not shown) is connected to the fuel passage 15 of each main combustion nozzle.

したがって、高温・高圧の圧縮空気３が燃焼器２内に流れ込み、この燃焼器２内で、この圧縮空気３がメイン燃焼バーナ６から噴射された燃料４と混合され、予混合ガスの旋回流１０２となって燃焼器尾筒４８内に流れ込む。また、圧縮空気３は、パイロット燃焼バーナ１から噴射された燃料４と混合され、図示しない種火により着火されて燃焼し、燃焼ガス１００となって燃焼器尾筒４８内に噴出する。このとき、燃焼ガス１００の一部が燃焼器尾筒４８内に火炎を伴って周囲に拡散するように噴出することで、メイン燃焼バーナ６から燃焼器尾筒４８内に流れ込んだ予混合ガス１０２に着火されて燃焼する。即ち、パイロット燃焼バーナ１から噴射されたパイロット燃料による火炎１０１により、メイン燃焼バーナ６からの希薄予混合燃料の安定燃焼を行うための保炎を行うことができる。また、パイロット燃焼バーナ１の端部に保炎器１２を配置している。図３−１に示すように、この保炎器１２の下流には、リ・サーキュレーションゾーン（再循環領域）１０３と呼ばれる領域が発生する。この再循環領域１０３の中では、メイン燃焼バーナ６の高温の既燃ガスが中心軸の近くで逆流するような渦運動をするので、これがメイン燃焼バーナ６の希薄予混合燃料を定常的に着火させるのに役立っている。 Therefore, the high-temperature and high-pressure compressed air 3 flows into the combustor 2, and the compressed air 3 is mixed with the fuel 4 injected from the main combustion burner 6 in the combustor 2, and the swirl flow 102 of the premixed gas And flows into the combustor tail cylinder 48. Further, the compressed air 3 is mixed with the fuel 4 injected from the pilot combustion burner 1, ignited and burned by a not-shown type fire, and becomes a combustion gas 100 which is ejected into the combustor tail cylinder 48. At this time, a part of the combustion gas 100 is ejected so as to diffuse into the combustor tail cylinder 48 with a flame, so that the premixed gas 102 flowing into the combustor tail cylinder 48 from the main combustion burner 6. Is ignited and burns. That is, flame holding for stable combustion of the lean premixed fuel from the main combustion burner 6 can be performed by the flame 101 of the pilot fuel injected from the pilot combustion burner 1. A flame holder 12 is disposed at the end of the pilot combustion burner 1. As shown in FIG. 3A, an area called a recirculation zone (recirculation area) 103 is generated downstream of the flame holder 12. In this recirculation region 103, since the hot burned gas of the main combustion burner 6 performs a vortex motion such that it flows backward near the center axis, this constantly ignites the lean premixed fuel of the main combustion burner 6. It is useful to let you.

次に、本発明に係る第１の実施の形態によるパイロット燃焼バーナ１について詳細に説明する。 Next, the pilot combustion burner 1 according to the first embodiment of the present invention will be described in detail.

図３−１に第１の実施の形態に係るパイロット燃焼バーナ１の要部を拡大して示した断面図を、図３−２にパイロット燃焼バーナ１をパイロット混合ガスが噴射された側から見た平面図を示す。 FIG. 3A is an enlarged cross-sectional view of the main part of the pilot combustion burner 1 according to the first embodiment, and FIG. FIG.

図３−１に示すように、パイロット燃焼バーナ１は、その中心に拡散パイロットノズル１１を配置し、拡散パイロットノズル１１を取り囲むように予混合パイロットノズル１０を配置している。予混合パイロットノズル１０に燃料を供給する燃料流路６２、拡散パイロットノズル１１に燃料４を供給する燃料流路６３は、それぞれが独立した系統になっており、燃料流量を別々に変更できる。 As shown in FIG. 3A, the pilot combustion burner 1 has a diffusion pilot nozzle 11 disposed at the center thereof, and a premixed pilot nozzle 10 disposed so as to surround the diffusion pilot nozzle 11. The fuel flow path 62 for supplying fuel to the premixed pilot nozzle 10 and the fuel flow path 63 for supplying fuel 4 to the diffusion pilot nozzle 11 are independent systems, and the fuel flow rate can be changed separately.

予混合パイロットノズル１０の燃料噴射口１６と拡散パイロットノズル１１の燃料噴射口１７は保炎器１２部分に設けている。保炎器１２はパイロット混合ガスが噴射された側から見ると円盤状であるが、側面方向から見ると断面形状が台形をしており、燃料噴射方向に進むにつれてその半径が大きくなっている。また、保炎器１２のパイロット混合ガス噴射口側の端面位置は、燃焼器２の中心軸を通る直線に垂直な方向で見た場合、メイン燃焼バーナ６の延長管１３の出口部分と略同じ位置になっている。 The fuel injection port 16 of the premix pilot nozzle 10 and the fuel injection port 17 of the diffusion pilot nozzle 11 are provided in the flame holder 12 portion. The flame holder 12 has a disc shape when viewed from the side where the pilot mixed gas is injected, but has a trapezoidal cross section when viewed from the side surface direction, and its radius increases as the fuel injection direction proceeds. Further, the end face position on the pilot gas mixture injection port side of the flame stabilizer 12 is substantially the same as the outlet portion of the extension pipe 13 of the main combustion burner 6 when viewed in a direction perpendicular to a straight line passing through the central axis of the combustor 2. Is in position.

上述の構成において、拡散パイロットノズル１１は保炎器１２に所定の径で複数個貫通させた燃料噴射口１７から燃料４を噴出することで、周囲の圧縮空気３と混合を行い、燃焼器２内で拡散燃焼を行う。なお、拡散パイロットノズル１１の燃料噴射口１７は、保炎器１２の半径方向外側に向って燃料を放出できるようにすることが望ましく、そのため、保炎器１２の半径方向に沿って貫通させ、燃料噴射方向が保炎器１２の外縁方向になるように保炎器１２を垂直に貫通する直線と所定の傾斜角度を持たることが好ましい。このようにすることで、燃料４を半径方向外側に噴出できるので、拡散パイロットノズルからの燃焼ガスが保炎器１２の外周方向にあるメイン燃焼バーナの延長管１３の出口まで到達し、メイン燃焼バーナからの希薄予混合燃料の保炎性が増し燃焼が安定する。 In the above-described configuration, the diffusion pilot nozzle 11 mixes with the surrounding compressed air 3 by ejecting the fuel 4 from the fuel injection ports 17 that are passed through the flame holder 12 with a predetermined diameter, and the combustor 2. Perform diffusion combustion in the interior. It is desirable that the fuel injection port 17 of the diffusion pilot nozzle 11 be made to be able to discharge fuel toward the radially outer side of the flame holder 12, so that it penetrates along the radial direction of the flame holder 12, It is preferable to have a predetermined inclination angle with a straight line penetrating the flame holder 12 vertically so that the fuel injection direction is in the outer edge direction of the flame holder 12. In this way, the fuel 4 can be ejected radially outward, so that the combustion gas from the diffusion pilot nozzle reaches the outlet of the extension pipe 13 of the main combustion burner in the outer peripheral direction of the flame holder 12, and the main combustion The flame holding property of the lean premixed fuel from the burner is increased and the combustion is stabilized.

一方、予混合パイロットノズル１０は保炎器１２に所定の径で複数個貫通させた孔１４とこの孔１４から所定の寸法の隙間を設けた位置に設けた予混合パイロットノズル１０の燃料噴射口１６で構成している。燃料噴射口１５から噴出した燃料４は、圧縮空気３と混合し、孔１４からパイロット混合ガスとして放出され、燃焼器２内で燃焼する。 On the other hand, the premix pilot nozzle 10 has a plurality of holes 14 having a predetermined diameter passing through the flame holder 12 and a fuel injection port of the premix pilot nozzle 10 provided at a position where a gap of a predetermined dimension is provided from the hole 14. 16. The fuel 4 ejected from the fuel injection port 15 is mixed with the compressed air 3, discharged as a pilot mixed gas from the hole 14, and combusted in the combustor 2.

図３−２に示すように、予混合パイロットノズル１０は、複数のメイン燃焼バーナ６（図では８個）の内側にある保炎器１２の所定の半径位置において、その周方向に複数の孔１４（図では８個）を貫通させ、また、その孔の中心位置でかつ燃料噴射に関して上流側に予混合ノズルの燃料噴射口１６を設ける。 As shown in FIG. 3-2, the premix pilot nozzle 10 has a plurality of holes in the circumferential direction at a predetermined radial position of the flame holder 12 inside the plurality of main combustion burners 6 (eight in the figure). 14 (eight in the figure) are penetrated, and the fuel injection port 16 of the premixing nozzle is provided at the center of the hole and upstream of the fuel injection.

このとき、保炎器１２の中心と各孔１４の中心を結ぶ直線の延長上に各メイン燃焼ノズル７がこないようにするため、孔１４の周方向位置をメイン燃焼ノズル７の周方向位置とずらして配置する。なお、孔１４の周方向の間隔は一定にすることが好ましい。一方、拡散パイロットノズル噴射口１７についても保炎器１２の所定の半径位置に設けているが、その中心と保炎器１２の中心を結ぶ直線上の延長上にメイン燃焼ノズル７の中心位置がくるように、拡散パイロットノズル噴射口１７を配置することが望ましい。 At this time, in order to prevent the main combustion nozzles 7 from extending on the straight line connecting the center of the flame holder 12 and the center of each hole 14, the circumferential position of the hole 14 is set as the circumferential position of the main combustion nozzle 7. Shift and arrange. In addition, it is preferable to make the space | interval of the circumferential direction of the hole 14 constant. On the other hand, the diffusion pilot nozzle injection port 17 is also provided at a predetermined radial position of the flame holder 12, but the center position of the main combustion nozzle 7 is located on a straight line connecting the center thereof and the center of the flame holder 12. It is desirable to arrange the diffusing pilot nozzle injection port 17 so as to be formed.

以上により、予混合パイロットノズル１０が周方向に一定の間隔を持って配置されているので、予混合パイロットノズル１０から噴出されるパイロット混合ガスは周方向には切れ目ができることになる。メイン燃焼バーナ６から噴出した燃焼ガスは燃焼器尾筒４８内で循環し、高温の既燃ガスの循環流になり、この高温の既燃ガスの循環流が予混合パイロットノズル１０から噴出したパイロット混合ガスの間を抜けてメイン燃焼バーナ６の延長管１３出口まで到達し、メイン燃焼バーナ６からの希薄予混合燃料の保炎性が増し燃焼が安定するので、燃焼振動を抑制することができる。 As described above, since the premixed pilot nozzle 10 is arranged at a constant interval in the circumferential direction, the pilot mixed gas ejected from the premixed pilot nozzle 10 can be cut in the circumferential direction. The combustion gas ejected from the main combustion burner 6 circulates in the combustor tail cylinder 48 to become a high-temperature burned gas circulation flow, and this high-temperature burned gas circulation flow is ejected from the premixed pilot nozzle 10. Since the gas mixture passes through the mixed gas and reaches the outlet of the extension pipe 13 of the main combustion burner 6 and the flame holding property of the lean premixed fuel from the main combustion burner 6 is increased and the combustion is stabilized, combustion vibration can be suppressed. .

なお、図３−２では、予混合パイロットノズル１０及び拡散パイロットノズル１１の燃料噴射口の個数をメイン燃焼バーナ６と同数にしているが、その個数は適宜変更可能である。また、図３−２において、拡散ノズルの燃料噴射口１７は簡便のため円形で記載しているが、実際の形状は燃料噴出方向に長軸を持つ楕円形である。 In FIG. 3-2, the number of fuel injection ports of the premix pilot nozzle 10 and the diffusion pilot nozzle 11 is the same as that of the main combustion burner 6, but the number can be changed as appropriate. Further, in FIG. 3-2, the fuel injection port 17 of the diffusion nozzle is described as a circle for simplicity, but the actual shape is an ellipse having a long axis in the fuel injection direction.

（第２の実施の形態）
第２の実施の形態によるパイロット燃焼バーナ１は、図４−２に示すように保炎器１２をパイロット混合ガスが噴射された側から見た平面上に孔１４の中心線を投影した場合に、その中心線を投影した直線が孔１４を設けた保炎器１２の半径位置における円周の接線と平行となるようにするように孔１４を貫通させるか、または投影直線が保炎器１２の外周方向に向うように孔１４を貫通させるようにするため、基盤部分２６を垂直に貫通する直線と所定の角度で傾斜させている。つまり、孔１４を通過した圧縮空気３と燃料４のパイロット混合ガスが保炎器１２の中心軸まわりにその周方向に旋回させるようにするか、または外縁方向に向うように孔１４を貫通させる。 (Second Embodiment)
In the pilot combustion burner 1 according to the second embodiment, the center line of the hole 14 is projected on a plane when the flame holder 12 is viewed from the side where the pilot mixed gas is injected as shown in FIG. The center line is projected so that the straight line is parallel to the circumferential tangent at the radial position of the flame holder 12 provided with the hole 14, or the projected straight line is passed through the flame holder 12. The base portion 26 is inclined at a predetermined angle with a straight line penetrating the base portion 26 so as to pass through the hole 14 so as to face in the outer peripheral direction. That is, the pilot mixed gas of the compressed air 3 and the fuel 4 that has passed through the hole 14 is swung in the circumferential direction around the central axis of the flame holder 12 or is penetrated through the hole 14 toward the outer edge. .

このように孔１４を貫通させることで、予混合ノズルの燃料噴射口１６から放出されるパイロット混合ガスは、周方向（図４−２の矢印方向）に放出され、旋回に伴う遠心力により、保炎器１２の外縁方向に広がる。なお、図４−２において、拡散ノズルの燃料噴射口１７及び孔１４は簡便のため円形で記載しているが、実際の形状は燃料噴出方向に長軸を持つ楕円形である。 By penetrating the hole 14 in this way, the pilot mixed gas released from the fuel injection port 16 of the premixing nozzle is released in the circumferential direction (arrow direction in FIG. 4-2), and due to the centrifugal force accompanying the swirling, It spreads in the outer edge direction of the flame holder 12. In FIG. 4B, the fuel injection port 17 and the hole 14 of the diffusion nozzle are described in a circular shape for the sake of simplicity, but the actual shape is an ellipse having a long axis in the fuel injection direction.

上述の構成によりパイロット混合ガスが外縁方向に広がることで、パイロット燃焼ガスと高温のメイン既燃ガスの循環流との衝突が抑制される。これにより、低ＮＯｘ化のために、パイロット比率を低く運転することでパイロット燃焼ガスが低温になった場合でも、高温の既燃ガスの循環流はメイン燃焼バーナの延長管出口まで到達しやすくなっているので、メイン燃焼バーナからの希薄予混合燃料の保炎性が増し、燃焼が安定するので、燃焼振動を抑制することができる。一方、パイロット燃焼ガスが外周方向に噴出されることで、メイン燃焼バーナ出口付近の保炎器基部に到達しやすくなり、パイロット比率を高めパイロット燃焼ガス温度を高くして運転している場合には、パイロット燃焼ガスによるメイン燃焼バーナからの希薄予混合燃料の保炎を高めることができるので燃焼を安定させ、燃焼振動を抑制することができる。 With the above-described configuration, the pilot mixed gas spreads in the outer edge direction, so that collision between the pilot combustion gas and the circulating flow of the high-temperature main burned gas is suppressed. Thereby, even if the pilot combustion gas becomes low temperature by operating at a low pilot ratio in order to reduce NOx, the circulating flow of the high temperature burned gas easily reaches the outlet of the extension pipe of the main combustion burner. Therefore, the flame holding property of the lean premixed fuel from the main combustion burner is increased and the combustion is stabilized, so that the combustion vibration can be suppressed. On the other hand, when the pilot combustion gas is ejected in the outer circumferential direction, it becomes easy to reach the flame holder base near the main combustion burner outlet, and when the pilot combustion gas temperature is increased and the pilot combustion gas temperature is increased. Since flame holding of the lean premixed fuel from the main combustion burner by the pilot combustion gas can be enhanced, combustion can be stabilized and combustion vibration can be suppressed.

（第３の実施の形態）
第３の実施の形態によるパイロット燃焼バーナ１は、図５−１及び図５−２に示すように、予混合パイロットノズル１０における保炎器１２の孔１４を、保炎器１２の半径方向外側に向って貫通させたものである。このようにすることで、パイロット混合ガスを直接外周方向に広げることができ、低温になったパイロット混合ガスが高温のメイン燃焼ガスの循環流を妨げることを抑制する効果が高まる。また、パイロット混合ガスが外周方向のメイン燃焼バーナ６の保炎基部に到達しやすくなるので、パイロット比を高めることで、パイロット燃焼ガスの温度を高くして運転している場合には、メイン燃焼バーナ６の保炎基部での保炎性を高めることができる。なお、図５−２において、拡散ノズルの燃料噴射口１７及び孔１４は簡便のため円形で記載しているが、実際の形状は燃料噴出方向に長軸を持つ楕円形である。 (Third embodiment)
As shown in FIGS. 5A and 5B, the pilot combustion burner 1 according to the third embodiment is configured so that the holes 14 of the flame holder 12 in the premix pilot nozzle 10 are formed radially outward of the flame holder 12. It is made to penetrate toward. By doing in this way, pilot mixed gas can be directly extended to an outer peripheral direction, and the effect which suppresses that the pilot mixed gas used as the low temperature obstructs the circulation flow of high temperature main combustion gas increases. Further, since the pilot mixed gas easily reaches the flame holding base of the main combustion burner 6 in the outer peripheral direction, the main combustion is increased when the pilot combustion gas is operated at a high temperature by increasing the pilot ratio. The flame holding property at the flame holding base of the burner 6 can be enhanced. In FIG. 5B, the fuel injection port 17 and the hole 14 of the diffusion nozzle are shown in a circular shape for simplicity, but the actual shape is an ellipse having a long axis in the fuel injection direction.

（第４の実施の形態）
第４の実施の形態によるパイロット燃焼バーナ１は、図６−１、図６−２に示すようにメイン燃焼バーナ６の延長管１３出口位置と保炎器１２の位置関係に関し、燃焼器２の軸心を通り燃焼器尾筒４８に向う直線に直行する方向で見たときに、保炎器１２の位置をメイン燃焼バーナ６の延長管１３出口位置より前方に所定の距離で離して設置したものである。さらに、保炎器１２のパイロット燃焼ガスを噴射する側の端面の外周上でかつメイン燃焼バーナ６の延長管１３の内側部分には、周方向に連続しているコーン部材１８を配置している。コーン部材１８の端面位置は燃焼器２の軸心を通る直線に垂直な方向で見たときに、メイン燃焼バーナ６の延長管１３の出口部分と略同じ位置になっている。 (Fourth embodiment)
The pilot combustion burner 1 according to the fourth embodiment relates to the positional relationship between the outlet position of the extension pipe 13 of the main combustion burner 6 and the flame holder 12 as shown in FIGS. When viewed in a direction perpendicular to the straight line passing through the axial center toward the combustor tail cylinder 48, the position of the flame holder 12 is set a predetermined distance away from the outlet position of the extension pipe 13 of the main combustion burner 6. Is. Further, a cone member 18 that is continuous in the circumferential direction is disposed on the outer periphery of the end face of the flame holder 12 on the side where the pilot combustion gas is injected and on the inner side of the extension pipe 13 of the main combustion burner 6. . The end surface position of the cone member 18 is substantially the same as the outlet portion of the extension pipe 13 of the main combustion burner 6 when viewed in a direction perpendicular to a straight line passing through the axis of the combustor 2.

このように、保炎器１２を燃焼ガスの噴出方向に関する位置関係において、メイン燃焼バーナ６の延長管１３出口位置の上流側に所定の距離で離して設置し、かつ保炎器１２の外周にコーン部材１８を設置したことで、燃焼器尾筒４８内を循環してきたメイン燃焼ガスは保炎器１２の後流の空間に広がり、その後、保炎器１２の外周のコーン部材１８に沿って流れ、メイン燃焼バーナ６の延長管１３出口付近では延長管１３出口を出た直後のメイン燃焼バーナ６から噴出された希薄予混合燃料と略平行に合流するようになる。このため、延長管１３出口付近における流れの乱れが小さくなり、メイン燃焼バーナ６の希薄予混合燃料の燃焼速度が低下し、それによりメイン燃焼バーナの混合ガスの燃焼速度は低下して、その火炎は、希薄予混合燃料の噴出方向に長く延びる。 As described above, the flame holder 12 is installed at a predetermined distance upstream of the outlet position of the extension pipe 13 of the main combustion burner 6 in the positional relationship with respect to the ejection direction of the combustion gas, and on the outer periphery of the flame holder 12. By installing the cone member 18, the main combustion gas circulated in the combustor tail cylinder 48 spreads in the space downstream of the flame holder 12, and then along the cone member 18 on the outer periphery of the flame holder 12. In the vicinity of the outlet of the extension pipe 13 of the main combustion burner 6, the main combustion burner 6 merges with the lean premixed fuel injected from the main combustion burner 6 immediately after exiting the extension pipe 13. For this reason, the turbulence of the flow in the vicinity of the outlet of the extension pipe 13 is reduced, the combustion speed of the lean premixed fuel in the main combustion burner 6 is lowered, and thereby the combustion speed of the mixed gas in the main combustion burner is lowered, and the flame Extends long in the jet direction of the lean premixed fuel.

延長管１３出口を出た直後のメイン燃焼バーナ６の希薄予混合燃料内では、燃料と圧縮空気との均一な混合が進んでいる途中であり、ここでの流れの乱れが大きいと、完全に予混合できる前に燃焼が進む可能性がある。したがって、第４の実施の形態のパイロット燃焼バーナの構成により、延長管１３から噴出した希薄予混合燃料と循環してきた燃焼ガスとの合流角度を小さくし、略平行にすることで燃焼速度を遅くすることができ、燃料と圧縮空気の均一な混合が完了するまでの時間が確保できるので、予混合効果が促進されることになり、メイン燃焼バーナの燃焼における低ＮＯｘ化を実現することができるという効果が得られる。 In the lean premixed fuel of the main combustion burner 6 immediately after exiting the extension pipe 13, the uniform mixing of the fuel and the compressed air is in progress, and if the flow turbulence here is large, Combustion may proceed before it can be premixed. Therefore, with the configuration of the pilot combustion burner of the fourth embodiment, the merging angle between the lean premixed fuel ejected from the extension pipe 13 and the circulated combustion gas is reduced, and the combustion speed is lowered by making them substantially parallel. Since the time until the uniform mixing of the fuel and the compressed air can be secured, the premixing effect is promoted, and the NOx reduction in the combustion of the main combustion burner can be realized. The effect is obtained.

なお、コーン部材１８は周方向に連通しているが、図６−３、図６−４に示すように、延長管１３の出口部分を沿うように、かつ、延長管１３との間に所定の間隔を空けて複数の板材１９を設置しても上述と同様の効果が得られる。なお、図６−２と図６−４において、拡散ノズルの燃料噴射口１７は簡便のため円形で記載しているが、実際の形状は燃料噴出方向に長軸を持つ楕円形である。 The cone member 18 communicates in the circumferential direction. As shown in FIGS. 6-3 and 6-4, the cone member 18 is provided along the outlet portion of the extension pipe 13 and between the extension pipe 13 and the predetermined length. The same effect as described above can be obtained even if a plurality of plate members 19 are installed with an interval of. In FIGS. 6-2 and 6-4, the fuel injection port 17 of the diffusion nozzle is described as a circle for simplicity, but the actual shape is an ellipse having a long axis in the fuel injection direction.

（第５の実施の形態）
第５の実施の形態によるパイロット燃焼バーナは、図７−１に示すように予混合パイロットノズル１０の燃料流路６２が、通路の内径よりも大きなキャビティ２１に接続し、そのキャビティ２１には外径がキャビティ２１よりも大きく、キャビティ２１の燃料方向の流れで下流側になる部分を覆って蓋をする円盤状の多孔板２２が設置されている。多孔板２２の周方向には孔２３を複数設けている。この多孔板２２に対し、燃料噴射方向において下流側位置に、保炎器１２が所定の間隔を空けて配置される。このとき、多孔板に設けられた孔２３の周方向位置は、保炎器１２に設けた孔１４の周方向位置と一致し、その径は孔１４と略同じ大きさになっている。多孔板２２の外径は保炎器１２の外径と同じ程度である。また、多孔板２２の中心部分には拡散パイロットノズル１１の燃料流路６３である配管を貫通させ、保炎器１２に設けた拡散パイロットノズル１１の燃料噴射口１７から燃料を噴出することができる。 (Fifth embodiment)
In the pilot combustion burner according to the fifth embodiment, as shown in FIG. 7A, the fuel flow path 62 of the premix pilot nozzle 10 is connected to the cavity 21 larger than the inner diameter of the passage, A disk-shaped perforated plate 22 that is larger in diameter than the cavity 21 and covers and covers a portion of the cavity 21 that flows downstream in the fuel direction is provided. A plurality of holes 23 are provided in the circumferential direction of the porous plate 22. The flame holder 12 is disposed at a predetermined interval with respect to the porous plate 22 at a downstream position in the fuel injection direction. At this time, the circumferential position of the hole 23 provided in the perforated plate coincides with the circumferential position of the hole 14 provided in the flame holder 12, and the diameter thereof is substantially the same as that of the hole 14. The outer diameter of the porous plate 22 is approximately the same as the outer diameter of the flame holder 12. In addition, a pipe which is the fuel flow path 63 of the diffusion pilot nozzle 11 can be passed through the central portion of the porous plate 22, and fuel can be ejected from the fuel injection port 17 of the diffusion pilot nozzle 11 provided in the flame holder 12. .

予混合パイロットノズルの燃料流路６２を通って送られた燃料４は、燃料通路６２に接続したキャビティ２１を経由して多孔板２２の孔２３から噴出し、多孔板２２と保炎器１２の隙間に沿って流れ込んできた圧縮空気３と混合され、保炎器１２に設けた孔１４から圧縮空気と燃料の予混合ガスとして噴出される。 The fuel 4 sent through the fuel flow path 62 of the premix pilot nozzle is ejected from the hole 23 of the perforated plate 22 via the cavity 21 connected to the fuel passage 62, and between the perforated plate 22 and the flame holder 12. It is mixed with the compressed air 3 flowing in along the gap, and is ejected from the hole 14 provided in the flame holder 12 as a premixed gas of compressed air and fuel.

さらに、本手段によれば、多孔板２２と保炎器１２の隙間に沿った圧縮空気３の流れを作ることで流動する圧縮空気３と保炎器１２の接触面積が確保でき、この結果、燃焼火炎に曝されて加熱された保炎器１２の効率のよい冷却効果を得ることができる。 Furthermore, according to this means, the contact area between the compressed air 3 and the flame holder 12 flowing can be secured by creating a flow of the compressed air 3 along the gap between the perforated plate 22 and the flame holder 12. An efficient cooling effect of the flame holder 12 exposed to the combustion flame and heated can be obtained.

１パイロット燃焼バーナ
２燃焼器
３圧縮空気
４燃料
６メイン燃焼バーナ
７メイン燃焼ノズル
８燃焼器内筒
１０予混合パイロットノズル
１１拡散パイロットノズル
１２保炎器
１３延長管
１４孔
１５メインノズルの燃料流路
１６予混合ノズルの燃料噴射口
１７拡散ノズルの燃料噴射口
１８コーン部材
１９板材
２１キャビティ
２２多孔板
２３多孔板の孔
６２予混合パイロットノズルの燃料流路
６３拡散パイロットノズルの燃料流路
１００メイン燃焼ガス
１０１パイロット火炎
１０２予混合ガスの旋回流
１０３予混合ガスのリ・サーキュレーションゾーン（再循環領域） DESCRIPTION OF SYMBOLS 1 Pilot combustion burner 2 Combustor 3 Compressed air 4 Fuel 6 Main combustion burner 7 Main combustion nozzle 8 Combustor inner cylinder 10 Premix pilot nozzle 11 Diffusion pilot nozzle 12 Flame holder 13 Extension pipe 14 Hole 15 Fuel flow path of main nozzle 16 Premixing nozzle fuel injection port 17 Diffusion nozzle fuel injection port 18 Cone member 19 Plate material 21 Cavity 22 Perforated plate 23 Perforated plate hole 62 Premixing pilot nozzle fuel flow path 63 Diffusion pilot nozzle fuel flow path 100 Main combustion Gas 101 Pilot flame 102 Premixed gas swirl flow 103 Premixed gas recirculation zone (recirculation zone)

Claims

A pilot combustion burner disposed in the axial center of a combustor of a gas turbine,
At an arbitrary radial position of the flame holder installed at the tip of the pilot combustion burner, holes are arranged at regular intervals in the circumferential direction of the flame holder, and compressed air sent from the compressor flows into the holes. As well as
A premix pilot nozzle that mixes fuel and the compressed air and jets out of the hole by providing a fuel injection port upstream or inside the hole in the compressed air flow direction;
On the flame holder, a diffusion pilot nozzle that performs diffusion combustion by injecting fuel from a fuel injection port provided at a position different from the hole;
With
Regarding the positional relationship between the extension pipe outlet position of the main combustion burner and the flame holder, the position of the flame holder is determined when viewed in a direction orthogonal to a straight line passing through the axis of the combustor and toward the combustor tail tube. Install upstream from the extension pipe outlet,
Disposing a cone member that is continuous in the circumferential direction on the outer periphery of the flame holder and on the inner portion of the extension pipe of the main combustion burner;
Or a gas turbine pilot characterized in that a plurality of plates are arranged on the outer periphery of the flame holder and on the inner portion of the extension pipe of the main combustion burner so as to substantially coincide with the circumferential position of the extension pipe. Burning burner.

A pilot combustion burner disposed in the axial center of a combustor of a gas turbine,
At an arbitrary radial position of the flame holder installed at the tip of the pilot combustion burner, holes are arranged at regular intervals in the circumferential direction of the flame holder, and compressed air sent from the compressor flows into the holes. As well as
A premix pilot nozzle that mixes fuel and the compressed air and jets out of the hole by providing a fuel injection port upstream or inside the hole in the compressed air flow direction;
On the flame holder, a diffusion pilot nozzle that performs diffusion combustion by injecting fuel from a fuel injection port provided at a position different from the hole;
With
A fuel flow path connected to the pilot nozzle is connected to a cavity located upstream of the flame holder in a fuel supply direction in the fuel flow path;
The cavity has an outer diameter larger than that of the cavity, and a perforated plate that covers and covers the downstream side in the fuel supply direction in the fuel flow path is installed, and the perforated plate has a plurality of holes. Provided so that fuel can be injected from the hole,
The perforated plate is located upstream of the flame holder as viewed in the inflow direction of the compressed air, and is installed so as to provide a predetermined gap between the perforated plate and the flame holder,
Since the hole position in the circumferential direction of the perforated plate coincides with the hole position of the flame holder located downstream in the fuel injection direction, the compressed air flows into the gap between the porous plate and the flame holder. A pilot combustion burner for a gas turbine, comprising: a premix pilot nozzle that flows in and mixes and ejects the fuel jetted from the hole position of the perforated plate and the compressed air.

The premix pilot nozzle is
The pilot mixed gas containing the fuel and the compressed air is swirled in the circumferential direction by passing through the hole so as to be along the circumferential tangential direction at the radial position of the flame holder provided with the hole. The pilot combustion burner of a gas turbine according to claim 1 or 2 , wherein

The premix pilot nozzle is
It is passed through the hole toward the radially outer side of the flame holder, according to pilot mixed gas containing the compressed air and the fuel to be ejected radially outwardly to claim 1 or 2, characterized in Gas turbine pilot combustion burner.

A combustion cylinder in which compressed air and fuel are burned to generate combustion gas;
A pilot combustion burner disposed at an axial center in the combustion cylinder;
A gas turbine combustor comprising: a plurality of main combustion burners arranged to surround the pilot combustion burner in the combustion cylinder;
At an arbitrary radial position of the flame holder installed at the tip of the pilot combustion burner, holes are arranged at regular intervals in the circumferential direction of the flame holder, and compressed air sent from the compressor flows into the holes. As well as
A premix pilot nozzle that mixes fuel and the compressed air and ejects the compressed air from the hole by providing a fuel injection port on the upstream side of the hole in the flow direction of the compressed air;
On the flame holder, a diffusion pilot nozzle that performs diffusion combustion by injecting fuel from a fuel injection port provided at a position different from the hole, and
Regarding the positional relationship between the extension pipe outlet position of the main combustion burner and the flame holder, the position of the flame holder when viewed in a direction orthogonal to a straight line passing through the axis of the combustor and toward the combustor tail tube. Install upstream from the position of the extension pipe outlet,
Disposing a cone member that is continuous in the circumferential direction on the outer periphery of the flame holder and on the inner portion of the extension pipe of the main combustion burner;
Alternatively, a plurality of plates are arranged on the outer periphery of the flame holder and on the inner portion of the extension pipe of the main combustion burner so as to substantially coincide with the circumferential position of the extension pipe . .

  A combustion cylinder in which compressed air and fuel are burned to generate combustion gas;
  A pilot combustion burner disposed at an axial center in the combustion cylinder;
  A gas turbine combustor comprising: a plurality of main combustion burners arranged to surround the pilot combustion burner in the combustion cylinder;
  At an arbitrary radial position of the flame holder installed at the tip of the pilot combustion burner, holes are arranged at regular intervals in the circumferential direction of the flame holder, and compressed air sent from the compressor flows into the holes. As well as
  A premix pilot nozzle that mixes fuel and the compressed air and ejects the compressed air from the hole by providing a fuel injection port on the upstream side of the hole in the flow direction of the compressed air;
  On the flame holder, a diffusion pilot nozzle that performs diffusion combustion by injecting fuel from a fuel injection port provided at a position different from the hole, and
  A fuel flow path connected to the pilot nozzle is connected to a cavity located upstream of the flame holder in a fuel supply direction in the fuel flow path;
  The cavity has an outer diameter larger than that of the cavity, and a perforated plate that covers and covers the downstream side in the fuel supply direction in the fuel flow path is installed, and the perforated plate has a plurality of holes. Provided so that fuel can be injected from the hole,
  The perforated plate is located upstream of the flame holder as viewed in the inflow direction of the compressed air, and is installed so as to provide a predetermined gap between the perforated plate and the flame holder,
  Since the hole position in the circumferential direction of the perforated plate coincides with the hole position of the flame holder located downstream in the fuel injection direction, the compressed air flows into the gap between the porous plate and the flame holder. A gas turbine combustor comprising: a premix pilot nozzle that flows in and mixes and ejects the fuel and the compressed air ejected from a hole position of the perforated plate.

In a gas turbine that obtains rotational power by supplying fuel to compressed air compressed by a compressor and burning it with a combustor and supplying the generated combustion gas to the turbine,
The combustor
A combustion cylinder in which high-pressure air and fuel are burned to generate combustion gas;
A pilot combustion burner disposed in the center of the combustion cylinder;
A plurality of main combustion burners arranged to surround the pilot combustion burner in the combustion cylinder;
At an arbitrary radial position of the flame holder installed at the tip of the pilot combustion burner, holes are arranged at regular intervals in the circumferential direction of the flame holder, and compressed air sent from the compressor flows into the holes. As well as
A premix pilot nozzle that mixes fuel and the compressed air and ejects the compressed air from the hole by providing a fuel injection port on the upstream side of the hole in the flow direction of the compressed air;
On the flame holder, a diffusion pilot nozzle that performs diffusion combustion by injecting fuel from a fuel injection port provided at a position different from the hole, and
Regarding the positional relationship between the extension pipe outlet position of the main combustion burner and the flame holder, the position of the flame holder when viewed in a direction orthogonal to a straight line passing through the axis of the combustor and toward the combustor tail tube. Install upstream from the position of the extension pipe outlet,
Disposing a cone member that is continuous in the circumferential direction on the outer periphery of the flame holder and on the inner portion of the extension pipe of the main combustion burner;
Alternatively, a gas turbine is characterized in that a plurality of plates are arranged on the outer periphery of the flame holder and on the inner portion of the extension pipe of the main combustion burner so as to substantially coincide with the circumferential position of the extension pipe .

  In a gas turbine that obtains rotational power by supplying fuel to compressed air compressed by a compressor and burning it with a combustor and supplying the generated combustion gas to the turbine,
  The combustor
  A combustion cylinder in which high-pressure air and fuel are burned to generate combustion gas;
  A pilot combustion burner disposed in the center of the combustion cylinder;
  A plurality of main combustion burners arranged to surround the pilot combustion burner in the combustion cylinder;
  At an arbitrary radial position of the flame holder installed at the tip of the pilot combustion burner, holes are arranged at regular intervals in the circumferential direction of the flame holder, and compressed air sent from the compressor flows into the holes. As well as
  A premix pilot nozzle that mixes fuel and the compressed air and ejects the compressed air from the hole by providing a fuel injection port on the upstream side of the hole in the flow direction of the compressed air;
  On the flame holder, a diffusion pilot nozzle that performs diffusion combustion by injecting fuel from a fuel injection port provided at a position different from the hole, and
  A fuel flow path connected to the pilot nozzle is connected to a cavity located upstream of the flame holder in a fuel supply direction in the fuel flow path;
  The cavity has an outer diameter larger than that of the cavity, and a perforated plate that covers and covers the downstream side in the fuel supply direction in the fuel flow path is installed, and the perforated plate has a plurality of holes. Provided so that fuel can be injected from the hole,
  The perforated plate is located upstream of the flame holder as viewed in the inflow direction of the compressed air, and is installed so as to provide a predetermined gap between the perforated plate and the flame holder,
  Since the hole position in the circumferential direction of the perforated plate coincides with the hole position of the flame holder located downstream in the fuel injection direction, the compressed air flows into the gap between the porous plate and the flame holder. A gas turbine, comprising: a premix pilot nozzle that flows in and mixes and ejects the fuel and the compressed air ejected from a hole position of the perforated plate.