JP3855963B2

JP3855963B2 - Gas turbine rotor blade repair method and gas turbine rotor blade structure

Info

Publication number: JP3855963B2
Application number: JP2003138180A
Authority: JP
Inventors: 傑関原; 国弘市川
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 2003-05-16
Filing date: 2003-05-16
Publication date: 2006-12-13
Anticipated expiration: 2023-05-16
Also published as: JP2004340044A

Description

【０００１】
【発明の属する技術分野】
本発明は、燃焼ガスの膨張の際に発生する運動エネルギーを回転動力へ変換するガスタービン動翼の補修方法およびこの補修方法によって構成されるガスタービン動翼構造に関する。
【０００２】
【従来の技術】
特許文献１には、ガスタービン動翼における耐酸化、耐腐食コーティングに発生する表面のき裂の長さを計測し、このき裂が基材まで達しているか否かを推定するということが記載されている。
【０００３】
特許文献２には、基材にコーティング層を施したガスタービン翼の前記基材に発生したクラックまたは劣化相を除去するガスタービン翼の補修方法において、前記コーティング層を溶融薬品を用いずに除去する第一の工程と、前記基材に発生したクラックまたは劣化相の部位を切削する第二の工程と、を連続的に行うガスタービン翼の補修方法が記載されている。
【０００４】
特許文献３には、補修対象となるガスタービン静翼について、予め亀裂が発生する確率が高い部位を想定して予備品を用意しておき、当該部位に亀裂が発生したとき、前記予備品により当該部位を置換して補修するガスタービン静翼の補修方法が記載されている。
【０００５】
特許文献４には、圧縮機で圧縮された空気に、燃焼器で燃料を加えて燃焼ガスを発生させ、その高温、高速の燃焼ガスによりタービンを回転させ、発電機を駆動するガスタービンにおいて、上記ガスタービンの燃焼ガスを動翼に最適となる角度で送り込むために、燃焼器直後に位置し、タービンの起動停止に伴って生じる温度変動による熱疲労損傷を受けるガスタービン静翼において、構造解析あるいは実機における熱疲労き裂分布データから、高応力が発生し、き裂の成長が予想される部位について、き裂の起点となると予想される点から、き裂の成長経路と推定される領域に、冷却孔を有するガスタービン静翼構造が記載されている。
特許文献５には、き裂深さ評価方法が記載されている。
【０００６】
【特許文献１】
特開平９−２７３９７８号公報
【特許文献２】
特開２００１−３０３９０３号公報
【特許文献３】
特開２００１−２０７８０３号公報
【特許文献４】
特開２０００−１３０１０３号公報
【特許文献５】
特開平９−１９５７９５号公報
【０００７】
【発明が解決しようとする課題】
近年ガスタービン設備においては、夏場の電力需要の増大に対応するために出力の増大化が、また省エネルギーを目的とした高効率化が求められるようになってきた。
出力の増大化の手段としては、ガスタービンの環状流路面積、すなわち寸法の増大化が図られる傾向にある。また高効率化の手段としては圧縮機圧力比の上昇、および燃焼温度の向上が採用される傾向にある。これらはいずれもガスタービン動翼に作用する温度および荷重の増加に直結するために、ガスタービン動翼は今後更に高温、高遠心荷重環境下に曝される事が予想され、必然的に強度の向上および長寿命化が求められている。
さらに近年、電力料金の値下げに対する社会的な要望が強まってきている中で、発電コストの低減が急務となっている。特に燃焼器やタービン動静翼などの高温部品の補修費用は、ガスタービンの補修費用の多くを占めており、定期検査期間および工数の短縮が求められている。
【０００８】
さらに近年、外周に凹凸部を有し、回転時に隣接する翼と嵌合しあうシュラウドカバーを有するガスタービン動翼において、シュラウドカバーにおける嵌合部での摩耗を低減するために接触表面にガスタービン動翼よりも硬い部材を接合する構造、もしくは硬い部材を溶射する構造が採用されつつあるが、本構造を採用することにより、嵌合面から伝達される接触反力が原因となり嵌合面に近接する凹部に応力集中が生じ、凹部にき裂が発生しやすくなる可能性がある。
【０００９】
本発明は、シュラウドカバーの嵌合部に発生しやすい、あるいは発生したき裂の補修を小さな領域の加工で容易に行うようにして補修費用の低減を図ることのできるガスタービン動翼の補修方法および当該補修方法によって補修されたガスタービン動翼の構造を提供することを目的とする。
【００１０】
【課題を解決するための手段】
以上の課題を解決するには、外周に回転方向に凹凸部を有するシュラウドが設けられ、凹凸部が隣接するガスタービン動翼と互いに嵌合することにより外周側で拘束されるガスタービン動翼において、シュラウドカバーの凹凸部の凹部に発生したき裂部分近傍のみを除去することで、補修を容易とすることを特徴とするガスタービン動翼の補修方法の採用が効果的である。また、シュラウドカバーの凹凸部の凹部にてき裂が発生することが予測される部分のみを予めタービン動翼高さ方向に沿って上方より円形状（円弧状）に除去するガスタービン動翼構造の採用が効果的であり、本発明はその補修方法および補修されたガスタービン動翼構造を提供する。
【００１１】
【発明の実施の形態】
以下、本発明の実施例を図面に基づいて説明する。
図１にガスタービンの一般的な構造断面図を示す。ガスタービンは大きくわけて圧縮機１、燃焼器２およびタービン３から構成されている。圧縮機１は大気から吸い込んだ空気を作動流体として断熱圧縮し、燃焼器２は圧縮機１から供給された圧縮空気に燃料を混合し燃焼することで高温高圧のガスを生成し、そしてタービン３は燃焼器２から導入した燃焼ガスの膨張の際に回転動力を発生する。タービン３からの排気は大気中に放出される。タービン３にて発生した回転動力から圧縮機１を駆動する動力を差し引いた残りの動力が、ガスタービンの発生動力となり発電機を駆動する。
【００１２】
ガスタービン動翼１１は図２に示すように、翼部４、タービンホイール外周に加工された植込み溝へ嵌合されるファーツリー部５、および外周に回転方向に凹凸部８を有し、回転時に隣接するガスタービン翼のシュラウドカバーの凸凹部と嵌合しあうシュラウドカバー７を有する。
ガスタービン動翼は燃焼ガスの膨張の際に発生する運動エネルギーを外表面４Ａに受けて回転動力へ変換するために外表面は高温となる。
【００１３】
このように過酷な環境にさらされるガスタービン動翼は、熱疲労およびクリープなど最も損傷が発生しやすく、タービンの寿命を律する部品となっている。特に、前述のようにシュラウドカバーにおける嵌合部での摩耗を低減するために接触表面にガスタービン動翼よりも硬い部材を接合あるいは溶射する構造を採用したときに、硬い部材に隣接する部分、すなわち凹部の最へこみ部近傍において、き裂が発生しやすいことが判って来ており、当該き裂はタービンの寿命を律する部分となってきている。
【００１４】
図３は、図２のシュラウドカバー7の詳細を示す。この図において、翼部４は燃焼ガスの膨張の際に発生する運動エネルギーを外表面４Ａに受けて回転動力へ変換することを行う。翼部４の先端部の外周の外表面７１上には回転方向に凹凸部であって、嵌合部となる部分を備えたシュラウドカバー７が設けられる。シュラウドカバーの外表面７１上には、ガスタービン動翼１１の高さ方向に、ガスタービン車室方向に延在する細長状の突起３１がガス漏洩を防止するために設けられる。シュラウドカバー７は翼部４と一体とされるが、その端部において表面が曲面とされた一定の板状の厚さを有し、シュラウドカバー７の隣接側の一端には、凹部６およびこれらの凹部を挟んで凸部３４、３５が形成してある。従って、凹部６と凸部３４、３５によって１つの凹凸部８が形成される。他の隣接側の一端には、凹凸部８に嵌合するような形状、すなわち凹凸に逆形状した凸凹部が形成される。この場合であっても凸部と凹部とを有し、凹凸部ということができるが、両者は嵌合されることが重要である。
【００１５】
このように、隣接するガスタービン動翼の隣接部にはこれらの凹凸部８に嵌合するように、形状を凸部、凹部とした凸凹部が形成される。嵌合された状態を図４に示す。図４において、ガスタービン動翼１１の両側には隣接して他のガスタービン動翼１１Ａ、１１Ｂが配設される。それぞれのガスタービン動翼１１、１１Ａ、１１Ｂは前述のように、外周に回転方向に隣接するシュラウドカバー７、７Ａ、７Ｂを備える。
【００１６】
シュラウドカバー７は、その一端側において前述のように、凹凸部８を有し、他の一端側において凸凹部８１を有する。従って、凹凸部８には隣接するシュラウドカバー７Ａの凸凹部８１Ａが嵌合し、凸凹部８１には凹凸部８Ｂが嵌合している。凹凸部８、凸凹部８１Ａが嵌合することによって隣接するガスタービン動翼１１は互いに外周側で拘束される。
【００１７】
図５は、１つのガスタービン動翼１１のシュラウドカバー７の平面図を示し、凹凸部８、凸凹部８１についての拡大を示し、凹凸部８、凸凹部８１の凹部６、６１を概略的に示している。以下の図面も同じである。
【００１８】
以上のような構成において、図６に示すように凹凸部８、凸凹部８１の凹部の両側の表面に沿って嵌合部での摩耗を低減するためにガスタービン動翼よりも硬い材質の部材１２、１２１が接合あるいは溶射される。
【００１９】
このように、硬い材質の部材１２、１２１を接合あるいは溶射された場合には特に凹部６の最へこみ部付近であって、両側の硬い材質の対峙する二枚の板の近傍、特に最へこみ部においてき裂９、９１が発生することがある。これは、凹部６から伝達される接触反力が原因となり、凹部６に応力集中が生ずることによる。図７は、硬い材質の部材１２、１２１が接合あるいは溶射されないときにあっても部材１２、１２１がある程ではないが、応力集中によって同様に発生したき裂状態を示す。
【００２０】
図８は、図６に示すように凹部６、６１の最へこみ部にき裂９、９１が発生した場合に、き裂９、９１の近傍を除去して補修を行う状況を示す。また、き裂９、９１が発生していなくても、凹部６、６１の最へこみ部にはき裂９、９１が発生することが予測される場合には、予め図８に示すようにして除去することを行う。
図９は、図７の状態について図８と同様に対応することを示す。
【００２１】
き裂９、９１の除去に際しては、図１０に矢印で示すように、ガスタービン動翼１１の高さ方向に沿うようにシュラウドカバー７の板状部分についてき裂９，９１の近傍部分を含んで、上方から円弧状（円形状）１０に、シュラウドカバー７を貫通し、凹部の裏表面にまで達するようにして削り取る。すなわち、シュラウドカバー７の凹部６、６１の最へこみ部には、シュラウドカバー７の一部が削り取られて外部に開放された形の円弧状の貫通孔１００が形成される。この場合に、貫通孔１００は、突起３１までは到達しない大きさの孔とされる。また、貫通孔１００は、硬い材質の部材１２、１２１が接合あるいは溶射されている場合には、これらの部材１２、１２１までは到達しない大きさの孔とされる。凹部６、６１の最へこみ部から突起３１の高さ中央までの長さをＴとしたときに削り取る円弧状の円形の半径はＴよりも小さい。すなわち円弧状の円形は突起３１まで到達しない。いわば未到達の半径とされる。部材１２、１２１についても同様である。
【００２２】
以上のように、燃焼ガスの膨張の際に発生する運動エネルギーを外表面４Ａに受けて回転動力へ変換し、外周に回転方向に凹凸部８を有するシュラウドカバー７が設けられ、凹凸部８が隣接するガスタービン動翼１１Ａの凸凹部８１Ａと互いに嵌合することにより隣接するガスタービン動翼１１Ａとの間で外周側で拘束されるガスタービン動翼１１において、シュラウドカバー７の凹凸部８の凹部６に発生したき裂９部分を含んだ部分をガスタービン動翼高さ方向に、シュラウドカバー７を円弧状に貫通してシュラウドカバー７の一部を上方より除去するガスタービン動翼の補修方法が構成される。
【００２３】
また、燃焼ガスの膨張の際に発生する運動エネルギーを外表面４Ａに受けて回転動力へ変換し、外周に回転方向に凹凸部８を有するシュラウドカバー７が設けられ、凹凸部８が隣接するガスタービン動翼１１Ａの凸凹部８１Ａと互いに嵌合することにより隣接するガスタービン動翼１１Ａとの間で外周側で拘束されるガスタービン動翼１１において、シュラウドカバー７の凹凸部８の凹部６の最へこみ部を含んだ部分を予めガスタービン動翼高さ方向に、上方よりシュラウドカバー７を円弧状に貫通してシュラウドカバー７の一部を除去するガスタービン動翼の補修方法が構成される。
【００２４】
また、燃焼ガスの膨張の際に発生する運動エネルギーを外表面４Ａに受けて回転動力へ変換し、外周に回転方向に凹凸部８を、そしてガスタービン動翼１１の高さ方向に上方に細長状の突起３１を有するシュラウドカバー７が設けられ、凹凸部８が隣接するガスタービン動翼１１Ａの凸凹部８１Ａと互いに嵌合することにより隣接するガスタービン動翼１１Ａとの間で外周側で拘束されるガスタービン動翼１１において、シュラウドカバー７の凹凸部８の凹部６に発生したき裂９部分を含んだ部分をガスタービン動翼高さ方向に、突起３１に未到達の状態でシュラウドカバー７を円弧状に貫通してシュラウドカバー７の一部を上方より除去するガスタービン動翼の補修方法が構成される。
【００２５】
また、燃焼ガスの膨張の際に発生する運動エネルギーを外表面４Ａに受けて回転動力へ変換し、外周に回転方向に凹凸部８を、そしてガスタービン動翼１１の高さ方向に上方に細長状の突起３１を有するシュラウドカバー７が設けられ、凹凸部８が隣接するガスタービン動翼１１Ａの凸凹部８１と互いに嵌合することにより隣接するガスタービン動翼１１Ａとの間で外周側で拘束されるガスタービン動翼１１において、シュラウドカバー７の凹凸部８の凹部６の最へこみ部を含んだ部分を予めガスタービン動翼高さ方向に、突起３１に未到達の状態で外部に上方よりシュラウドカバー７を円弧状に貫通して、外部に開放された形状でシュラウドカバー７の一部を除去するガスタービン動翼の補修方法が構成される。
【００２６】
更に、隣接するガスタービン動翼１１Ａと嵌合する凹凸部８の凹部６に沿って接触面表面に、ガスタービン動翼よりも硬い材質の部材１２が接合あるいは溶射されているとき、前記円弧状に貫通する孔１００は板状の部材１２に未到達であるガスタービン動翼の補修方法が構成される。
【００２７】
以上のような補修方法によって、シュラウドカバー７の凹凸部８の凹部６の最へこみ部を含んだ部分を含んで、ガスタービン動翼高さ方向に、突起３１に、および硬い材質の部材１２に未到達の状態で上方よりシュラウドカバー７を円弧状に貫通してシュラウドカバー７の一部を除去し、外部に開放された形態で貫通孔１００が設けられているガスタービン動翼が構成される。
【００２８】
図６に示すように、ガスタービン動翼１１の外周には凹凸部８を有するシュラウドカバー７が設けられ、凹凸部８が隣接するガスタービン動翼と互いに嵌合することにより外周側で拘束され、また嵌合部での摩耗を低減するために接触表面にガスタービン動翼よりも硬い材質の部材１２を設けているときに、図８に示すようにシュラウドカバー７の凹凸部８の凹部６に発生したき裂９の近傍部分を、すなわち凹部の最へこみ部を含んで円弧状１０に除去することで、補修を容易とし、図１１に示すように延命化を図ることができるガスタービン動翼を提供する事が可能となる。またガスタービン動翼では、シュラウドカバー７の凹凸部８の凹部６に予めき裂が発生することが予測される場合には、その部分の近傍を円弧状１０に除去することで、ガスタービン動翼１１の延命化を図ることができるガスタービン動翼の補修方法を提供することが可能となる。尚、円形状カッターとしては種々のものが知られている。
ここで硬い部材を接合する代わりに溶射した構造を用いても良いことは前述した。
【００２９】
図１１において、起動停止したときに、上述のようにしてき裂９，９１を除去すると、継続使用の曲線Ａから検査時発見き裂長さ曲線Ｂに移行し、限界き裂長さに対してガスタービン動翼１１の延命化を図ることができる。この場合に、上述した補修方法は、図１０に示すようにガスタービン動翼１１の高さ方向に沿うように上方から円弧状１０に削ってシュラウドカバー７に貫通孔１００を設けることを行えば済み、他方向から削るよりも削除を容易に行うことができ、簡単にき裂９、９１を除去することができる。き裂を予測した場合にも同様の補修を行う。
【００３０】
【発明の効果】
本発明によれば、ガスタービン動翼は、翼部４とタービンホイール外周に加工された植込み溝へ嵌合されるファーツリー部５、隣接するガスタービン動翼と互いに嵌合することにより外周側で拘束される凹凸部８を有するシュラウドカバー７から構成され、シュラウド凹凸部８の凹部６に発生したき裂９、９１の近傍部分を円弧状１０にタービン動翼高さ方向に沿って上方より除去することで、補修交換を容易とすることを特徴とするガスタービン動翼補修方法およびこの補修に伴ってのガスタービン動翼構造の提供が可能となる。
【図面の簡単な説明】
【図１】ガスタービンの一般的な構造断面図。
【図２】ガスタービンの動翼の構造図。
【図３】図２の一部詳細構造図。
【図４】ガスタービン動翼が隣接する同士で嵌合する様子を示す図。
【図５】ガスタービン動翼外周のシュラウドを示す図。
【図６】シュラウド接触面にガスタービン動翼よりも硬い物質を接合したときにき裂が発生する様子を示す図。
【図７】シュラウド凹部にき裂が生じた様子を示す図。
【図８】接触面に動翼よりも硬い材質の部材を接合したシュラウドの凹部のき裂近傍部を除去する様子を示す図。
【図９】シュラウド凹部のき裂近傍部を除去する様子を示す図。
【図１０】き裂を除去する方法を示す図。
【図１１】本発明の適用による延命化効果を示す図。
【符号の説明】
１…圧縮機、２…燃焼器、３…タービン、４…翼部、５…ファーツリー部、６…凹部、７…シュラウドカバー、８…凹凸部、９…き裂、１０…円弧状(円形状、き裂近傍部分)、１１…タービン動翼、１２…ガスタービン動翼より硬い材質の部材（板状の部材）。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for repairing a gas turbine blade that converts kinetic energy generated during the expansion of combustion gas into rotational power, and a gas turbine blade structure constituted by the repair method.
[0002]
[Prior art]
Patent Document 1 describes that the length of a surface crack generated in an oxidation-resistant and corrosion-resistant coating in a gas turbine blade is measured, and it is estimated whether or not the crack reaches the base material. Has been.
[0003]
In Patent Document 2, in a gas turbine blade repair method for removing a crack or a deteriorated phase generated in the base material of a gas turbine blade having a coating layer applied to the base material, the coating layer is removed without using a molten chemical. A gas turbine blade repairing method is described in which a first step of performing and a second step of cutting a portion of a crack or a deteriorated phase generated in the base material are continuously performed.
[0004]
In Patent Document 3, for a gas turbine stationary blade to be repaired, a spare part is prepared in advance assuming a part having a high probability of occurrence of a crack, and when a crack occurs in the part, A repair method for a gas turbine stationary blade that replaces and repairs the part is described.
[0005]
In Patent Document 4, in a gas turbine that drives a generator by adding fuel to air compressed by a compressor and generating combustion gas by generating a combustion gas, rotating the turbine by the high-temperature, high-speed combustion gas, In order to send the combustion gas of the above gas turbine to the blade at an optimum angle, structural analysis is performed on the gas turbine stationary blade, which is located immediately after the combustor and suffers thermal fatigue damage due to temperature fluctuations caused by the start and stop of the turbine. Or, from the point where the stress is expected to be the starting point of the crack where the high stress is generated and the crack is expected to grow from the thermal fatigue crack distribution data in the actual machine, the region estimated as the crack growth path Describes a gas turbine stationary blade structure having cooling holes.
Patent Document 5 describes a crack depth evaluation method.
[0006]
[Patent Document 1]
JP-A-9-273978 [Patent Document 2]
JP 2001-303903 A [Patent Document 3]
JP 2001-207803 [Patent Document 4]
JP 2000-130103 A [Patent Document 5]
Japanese Patent Application Laid-Open No. 9-195595
[Problems to be solved by the invention]
In recent years, in gas turbine facilities, an increase in output has been demanded in order to cope with an increase in power demand in summer, and an increase in efficiency for the purpose of energy saving has been demanded.
As a means for increasing the output, there is a tendency to increase the annular flow passage area, that is, the size of the gas turbine. Further, as means for improving efficiency, there is a tendency to increase the compressor pressure ratio and improve the combustion temperature. Both of these are directly linked to the increase in temperature and load acting on the gas turbine blades, so it is expected that the gas turbine blades will be exposed to higher temperature and high centrifugal load environments in the future. There is a need for improvement and longer life.
Furthermore, in recent years, with the increasing social demand for price reduction, there is an urgent need to reduce power generation costs. In particular, the cost of repairing high-temperature parts such as combustors and turbine blades and stators occupies much of the repair cost of gas turbines, and the periodic inspection period and man-hours are required to be shortened.
[0008]
Further, in recent years, in a gas turbine rotor blade having an uneven portion on the outer periphery and having a shroud cover that fits with an adjacent blade during rotation, the gas turbine is provided on the contact surface in order to reduce wear at the fitting portion of the shroud cover. A structure that joins harder members than moving blades or a structure that sprays hard members is being adopted, but by adopting this structure, contact reaction force transmitted from the fitting surface causes the fitting surface. There is a possibility that stress concentration occurs in the adjacent recesses, and cracks are likely to occur in the recesses.
[0009]
The present invention relates to a gas turbine rotor blade repair method capable of reducing repair costs by easily repairing a crack that is likely to occur in a fitting portion of a shroud cover or by processing a small area. It is another object of the present invention to provide a structure of a gas turbine rotor blade repaired by the repair method.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, in a gas turbine rotor blade provided with a shroud having an uneven portion in the rotation direction on the outer periphery and constraining the uneven portion to an adjacent gas turbine rotor blade on the outer periphery side. In addition, it is effective to employ a gas turbine rotor blade repairing method that makes repair easier by removing only the vicinity of the crack portion generated in the concave portion of the uneven portion of the shroud cover. In addition, the gas turbine rotor blade structure in which only a portion where a crack is predicted to be generated in the concave portion of the concavo-convex portion of the shroud cover is previously removed in a circular shape (arc shape) from above along the turbine blade height direction. Employment is effective, and the present invention provides a repair method and a repaired gas turbine blade structure.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a general structural sectional view of a gas turbine. The gas turbine is roughly composed of a compressor 1, a combustor 2, and a turbine 3. The compressor 1 adiabatically compresses air sucked from the atmosphere as a working fluid, the combustor 2 mixes fuel with the compressed air supplied from the compressor 1 and burns to generate high-temperature and high-pressure gas, and the turbine 3. Generates rotational power when the combustion gas introduced from the combustor 2 expands. Exhaust gas from the turbine 3 is released into the atmosphere. The remaining power obtained by subtracting the power for driving the compressor 1 from the rotational power generated in the turbine 3 becomes the power generated by the gas turbine and drives the generator.
[0012]
As shown in FIG. 2, the gas turbine rotor blade 11 has a blade portion 4, a fur tree portion 5 that is fitted in an implantation groove formed on the outer periphery of the turbine wheel, and an uneven portion 8 in the rotation direction on the outer periphery. There is sometimes a shroud cover 7 that mates with the convex and concave portions of the shroud cover of the adjacent gas turbine blade.
Since the gas turbine rotor blade receives the kinetic energy generated during the expansion of the combustion gas at the outer surface 4A and converts it into rotational power, the outer surface becomes hot.
[0013]
Gas turbine rotor blades exposed to such harsh environments are most susceptible to damage such as thermal fatigue and creep, and are components that limit the life of the turbine. In particular, when a structure that joins or sprays a member harder than the gas turbine rotor blade on the contact surface in order to reduce wear at the fitting portion in the shroud cover as described above, a portion adjacent to the hard member, That is, it has been found that cracks are likely to occur in the vicinity of the most recessed portion of the recess, and the crack has become a part that regulates the life of the turbine.
[0014]
FIG. 3 shows details of the shroud cover 7 of FIG. In this figure, the wing part 4 receives the kinetic energy generated when the combustion gas expands on the outer surface 4A and converts it into rotational power. A shroud cover 7 is provided on the outer surface 71 on the outer periphery of the tip of the wing portion 4. The shroud cover 7 is provided with a portion that is an uneven portion in the rotational direction and serves as a fitting portion. On the outer surface 71 of the shroud cover, elongated projections 31 extending in the direction of the gas turbine casing are provided in the height direction of the gas turbine rotor blade 11 in order to prevent gas leakage. The shroud cover 7 is integrated with the wing portion 4, and has a certain plate-like thickness with a curved surface at the end thereof. The shroud cover 7 has a recess 6 and these at one end adjacent to the shroud cover 7. Convex portions 34 and 35 are formed across the concave portion. Accordingly, one concave and convex portion 8 is formed by the concave portion 6 and the convex portions 34 and 35. At one end of the other adjacent side, a shape that fits into the concavo-convex portion 8, that is, a convex concave portion that is reverse to the concavo-convex shape is formed. Even in this case, although it has a convex part and a recessed part and can be called an uneven part, it is important that both are fitted.
[0015]
Thus, the convex part which makes a shape a convex part and a concave part is formed in the adjacent part of an adjacent gas turbine rotor blade so that these uneven parts 8 may be fitted. The fitted state is shown in FIG. In FIG. 4, other gas turbine rotor blades 11 A and 11 B are disposed adjacent to both sides of the gas turbine rotor blade 11. As described above, each of the gas turbine rotor blades 11, 11A, 11B includes the shroud covers 7, 7A, 7B adjacent to the outer periphery in the rotational direction.
[0016]
As described above, the shroud cover 7 has the concavo-convex portion 8 at one end side thereof and the convex / concave portion 81 at the other end side. Therefore, the convex / concave portion 81 A of the adjacent shroud cover 7 A is fitted to the concave / convex portion 8, and the concave / convex portion 8 B is fitted to the convex / concave portion 81. The gas turbine rotor blades 11 adjacent to each other are constrained on the outer peripheral side by fitting the concave and convex portion 8 and the convex concave portion 81A.
[0017]
FIG. 5 shows a plan view of the shroud cover 7 of one gas turbine rotor blade 11, shows an enlargement of the concavo-convex portion 8 and the convex and concave portion 81, and schematically shows the concave and convex portions 8 and 61 of the convex and concave portion 81. Show. The following drawings are the same.
[0018]
In the configuration as described above, as shown in FIG. 6, a member made of a material harder than the gas turbine rotor blade in order to reduce wear at the fitting portions along the surfaces of both sides of the concave and convex portions 8 and the concave portions of the convex and concave portions 81. 12 and 121 are joined or sprayed.
[0019]
In this way, when the hard material members 12 and 121 are joined or sprayed, particularly in the vicinity of the most recessed portion of the recess 6, in the vicinity of the two opposite plates of the hard material on both sides, particularly the most recessed portion. Cracks 9 and 91 may occur. This is because the contact reaction force transmitted from the recess 6 causes the stress concentration in the recess 6. FIG. 7 shows a cracked state similarly generated by stress concentration, although there are not so many members 12, 121 even when the hard members 12, 121 are not joined or sprayed.
[0020]
FIG. 8 shows a situation where repair is performed by removing the vicinity of the cracks 9 and 91 when the cracks 9 and 91 are generated in the most recessed portions of the recesses 6 and 61 as shown in FIG. Further, when cracks 9 and 91 are predicted to occur at the most recessed portions of the recesses 6 and 61 even if the cracks 9 and 91 are not generated, as shown in FIG. To remove.
FIG. 9 shows that the state of FIG. 7 corresponds to that of FIG.
[0021]
When removing the cracks 9 and 91, as shown by arrows in FIG. 10, the plate-like portion of the shroud cover 7 includes the vicinity of the cracks 9 and 91 along the height direction of the gas turbine rotor blade 11. Then, it is scraped off in an arc shape (circular shape) 10 from above through the shroud cover 7 and reaching the back surface of the recess. That is, an arcuate through-hole 100 having a shape in which a part of the shroud cover 7 is cut off and opened to the outside is formed in the most recessed portion of the recesses 6 and 61 of the shroud cover 7. In this case, the through hole 100 is a hole having a size that does not reach the protrusion 31. Further, the through hole 100 is a hole having a size that does not reach the members 12 and 121 when the hard members 12 and 121 are joined or sprayed. When the length from the most recessed part of the recesses 6 and 61 to the center of the height of the protrusion 31 is T, the radius of the arcuate circular shape to be scraped is smaller than T. That is, the circular arc does not reach the protrusion 31. In other words, it is an unreachable radius. The same applies to the members 12 and 121.
[0022]
As described above, the kinetic energy generated during the expansion of the combustion gas is received by the outer surface 4A and converted into rotational power, and the shroud cover 7 having the concavo-convex portion 8 in the rotation direction is provided on the outer periphery. In the gas turbine rotor blade 11 constrained on the outer peripheral side between the adjacent gas turbine rotor blade 11A by fitting with the convex recess 81A of the adjacent gas turbine rotor blade 11A, the uneven portion 8 of the shroud cover 7 Repair of a gas turbine blade that removes a portion of the shroud cover 7 from above by penetrating the shroud cover 7 in an arc shape through a portion including a crack 9 portion generated in the recess 6 in the height direction of the gas turbine blade A method is configured.
[0023]
Further, the kinetic energy generated during the expansion of the combustion gas is received by the outer surface 4A and converted into rotational power, and the shroud cover 7 having the concavo-convex portion 8 in the rotation direction is provided on the outer periphery, and the concavo-convex portion 8 is adjacent to the gas. In the gas turbine rotor blade 11 constrained on the outer peripheral side between the adjacent gas turbine rotor blades 11A by fitting with the convex recesses 81A of the turbine rotor blade 11A, the recesses 6 of the concave and convex portions 8 of the shroud cover 7 A gas turbine rotor blade repairing method is provided in which a portion including the most recessed portion is previously passed in the gas turbine rotor blade height direction and the shroud cover 7 is passed through the shroud cover 7 from above to remove a part of the shroud cover 7. .
[0024]
Further, the kinetic energy generated during the expansion of the combustion gas is received by the outer surface 4A and converted into rotational power, the uneven portion 8 is rotated in the outer peripheral direction, and the gas turbine rotor blade 11 is elongated upward in the height direction. A shroud cover 7 having a protrusion 31 is provided, and the concave and convex portion 8 is constrained on the outer peripheral side between the adjacent gas turbine rotor blade 11A by fitting with the convex recess 81A of the adjacent gas turbine rotor blade 11A. In the gas turbine rotor blade 11, the shroud cover in a state where the portion including the crack 9 portion generated in the recess 6 of the uneven portion 8 of the shroud cover 7 has not reached the projection 31 in the height direction of the gas turbine rotor blade. A gas turbine rotor blade repairing method is constructed in which a portion of the shroud cover 7 is removed from above through a circular arc 7.
[0025]
Further, the kinetic energy generated during the expansion of the combustion gas is received by the outer surface 4A and converted into rotational power, the uneven portion 8 is rotated in the outer peripheral direction, and the gas turbine rotor blade 11 is elongated upward in the height direction. A shroud cover 7 having a protrusion 31 is provided, and the concave and convex portion 8 is constrained on the outer peripheral side between the adjacent gas turbine rotor blade 11A by fitting with the convex recess 81 of the adjacent gas turbine rotor blade 11A. In the gas turbine rotor blade 11, the portion including the concave portion 6 of the concave and convex portion 8 of the shroud cover 7 is previously exposed in the height direction of the gas turbine rotor blade in the state where the projection 31 has not been reached from the outside. A gas turbine rotor blade repairing method is configured in which the shroud cover 7 is penetrated in an arc shape and a part of the shroud cover 7 is removed in a shape opened to the outside.
[0026]
Further, when the member 12 made of a material harder than the gas turbine blade is joined or sprayed on the contact surface along the concave portion 6 of the concavo-convex portion 8 fitted to the adjacent gas turbine blade 11A, the arc shape is obtained. The hole 100 penetrating through the gas turbine constitutes a method for repairing a gas turbine rotor blade that has not reached the plate-like member 12.
[0027]
By the above repairing method, including the portion including the most recessed portion of the concave portion 6 of the concave and convex portion 8 of the shroud cover 7, the protrusion 31 and the hard material member 12 are formed in the gas turbine rotor blade height direction. A gas turbine rotor blade in which a through hole 100 is provided in a form open to the outside is formed by penetrating the shroud cover 7 in an arc shape from above and removing a part of the shroud cover 7 in an unreached state. .
[0028]
As shown in FIG. 6, a shroud cover 7 having a concavo-convex portion 8 is provided on the outer periphery of the gas turbine rotor blade 11, and the concavo-convex portion 8 is constrained on the outer peripheral side by fitting with an adjacent gas turbine rotor blade. Further, when the member 12 made of a material harder than the gas turbine rotor blade is provided on the contact surface in order to reduce wear at the fitting portion, as shown in FIG. 8, the concave portion 6 of the concavo-convex portion 8 of the shroud cover 7 is provided. The portion of the crack 9 generated in the vicinity of the crack 9, that is, including the most recessed portion of the recess, is removed in the arc shape 10, so that repair can be facilitated and the life of the gas turbine can be extended as shown in FIG. It is possible to provide wings. Further, in the gas turbine rotor blade, when a crack is predicted to occur in advance in the concave portion 6 of the concavo-convex portion 8 of the shroud cover 7, the vicinity of the portion is removed in an arc shape 10, thereby It is possible to provide a method for repairing a gas turbine rotor blade capable of extending the life of the blade 11. Various circular cutters are known.
As described above, instead of joining hard members, a sprayed structure may be used.
[0029]
In FIG. 11, when the cracks 9 and 91 are removed as described above when starting and stopping, the curve A is shifted from the continuous use curve A to the crack length curve B found at the time of inspection, and the gas turbine is compared with the limit crack length. The life of the rotor blade 11 can be extended. In this case, if the repair method mentioned above cuts into circular arc shape 10 from the upper direction along the height direction of the gas turbine rotor blade 11 as shown in FIG. 10, and provides the through-hole 100 in the shroud cover 7 is performed. In other words, it is easier to delete than to cut from another direction, and the cracks 9 and 91 can be easily removed. The same repair is performed when a crack is predicted.
[0030]
【The invention's effect】
According to the present invention, the gas turbine rotor blade is connected to the blade portion 4 and the fur tree portion 5 fitted in the implantation groove machined on the outer periphery of the turbine wheel, and the gas turbine rotor blade is fitted to the adjacent gas turbine rotor blade to each other. The shroud cover 7 having the concavo-convex portion 8 constrained by the above, and a portion near the cracks 9 and 91 generated in the concave portion 6 of the shroud concavo-convex portion 8 is formed into an arc shape 10 along the turbine blade height direction from above. By removing, it is possible to provide a gas turbine rotor blade repair method characterized by facilitating repair and replacement, and a gas turbine rotor blade structure accompanying this repair.
[Brief description of the drawings]
FIG. 1 is a general structural sectional view of a gas turbine.
FIG. 2 is a structural diagram of a moving blade of a gas turbine.
FIG. 3 is a partial detailed structural diagram of FIG. 2;
FIG. 4 is a view showing a state in which gas turbine rotor blades are fitted to each other adjacent to each other.
FIG. 5 is a view showing a shroud on the outer periphery of a gas turbine blade.
FIG. 6 is a diagram showing a state in which a crack is generated when a material harder than a gas turbine rotor blade is joined to a shroud contact surface.
FIG. 7 is a view showing a state in which a crack is generated in a shroud recess.
FIG. 8 is a view showing a state in which a crack vicinity portion of a concave portion of a shroud in which a member made of a material harder than a moving blade is joined to a contact surface is removed.
FIG. 9 is a view showing a state in which a crack vicinity portion of a shroud recess is removed.
FIG. 10 is a diagram showing a method for removing a crack.
FIG. 11 is a diagram showing a life extension effect by applying the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... Combustor, 3 ... Turbine, 4 ... Blade | wing part, 5 ... Far tree part, 6 ... Recessed part, 7 ... Shroud cover, 8 ... Uneven part, 9 ... Crack, 10 ... Arc shape (circle) (Shape, crack vicinity part), 11 ... turbine blade, 12 ... member of harder material than gas turbine blade (plate-like member).

Claims

The outer surface receives the kinetic energy generated during the expansion of the combustion gas and converts it into rotational power, and a shroud cover having a concavo-convex portion in the rotation direction is provided on the outer periphery, and the concavo-convex portion of the gas turbine blade adjacent to the concavo-convex portion. In the repair method of the gas turbine rotor blade restrained on the outer peripheral side between the adjacent gas turbine rotor blades by fitting with each other,
A recess portion including a cleft content Taki occurs uneven portion of the shroud cover to the gas turbine moving blade height direction, through the shroud cover in an arc shape as to remove from above a portion of the shroud cover When a member made of a material harder than the gas turbine rotor blade is joined or sprayed on the surface of the contact surface along the concave portion of the concavo-convex portion fitted to the adjacent gas turbine rotor blade, it penetrates in the arc shape. A method for repairing a gas turbine rotor blade, wherein the hole does not reach the member.

The outer surface receives the kinetic energy generated during the expansion of the combustion gas and converts it into rotational power, and a shroud cover having a concavo-convex portion in the rotation direction is provided on the outer periphery, and the concavo-convex portion of the gas turbine blade adjacent to the concavo-convex portion. In the repair method of the gas turbine rotor blade restrained on the outer peripheral side between the adjacent gas turbine rotor blades by fitting with each other,
To advance the gas turbine moving blade height direction laden portion the most recessed portion of the concave portions of the concavo-convex portion of the shroud cover, be one of removing a portion of the shroud cover through said shroud cover in an arc shape from above When a member made of a material harder than the gas turbine rotor blade is joined or sprayed on the surface of the contact surface along the concave portion of the concavo-convex portion fitted to the adjacent gas turbine rotor blade, the hole penetrating in the arc shape Is a method for repairing a gas turbine rotor blade, wherein the member does not reach the member.

Kinetic energy generated during combustion gas expansion is received on the outer surface and converted to rotational power, with irregularities in the rotational direction on the outer periphery, and elongated projections in the height direction of the gas turbine blades In a repairing method for a gas turbine rotor blade provided with a shroud cover, and the concave and convex portions are constrained on the outer peripheral side between adjacent gas turbine rotor blades by fitting with the concave and convex portions of adjacent gas turbine rotor blades. ,
A portion of the shroud cover including a crack portion formed in the concave portion of the shroud cover extends in the arc direction with the shroud cover penetrating in the arc direction without reaching the projection in the gas turbine rotor blade height direction. A member made of a material harder than the gas turbine blade is joined or sprayed on the surface of the contact surface along the concave portion of the concavo-convex portion fitted to the adjacent gas turbine blade. When the gas turbine rotor blade is repaired, the hole penetrating in the arc shape does not reach the member.

Kinetic energy generated during combustion gas expansion is received on the outer surface and converted to rotational power, with irregularities in the rotational direction on the outer periphery, and elongated projections in the height direction of the gas turbine blades In a repairing method for a gas turbine rotor blade provided with a shroud cover, and the concave and convex portions are constrained on the outer peripheral side between adjacent gas turbine rotor blades by fitting with the concave and convex portions of adjacent gas turbine rotor blades. ,
A portion including the concave portion of the concave portion of the shroud cover in the gas turbine rotor blade height direction in advance and penetrating through the shroud cover from above in an arc shape without reaching the projection. When a member made of a material harder than the gas turbine blade is joined or sprayed on the surface of the contact surface along the concave portion of the concavo-convex portion that fits with the adjacent gas turbine blade. The method of repairing a gas turbine rotor blade, wherein the hole penetrating in an arc shape does not reach the member.

Kinetic energy generated during combustion gas expansion is received on the outer surface and converted to rotational power, with irregularities in the rotational direction on the outer periphery, and elongated projections in the height direction of the gas turbine blades A shroud cover is provided, and the projections and depressions of the gas turbine blades are fitted to each other, and a member made of a material harder than the gas turbine blades is joined or sprayed so as to face the recesses of the projections and depressions. In the gas turbine rotor blade restrained on the outer peripheral side between the adjacent gas turbine rotor blades,
The shroud cover includes a concave portion of the uneven portion of the shroud cover, and includes a shroud cover from above in a state where the projection and the hard material member have not been reached in the gas turbine rotor blade height direction. A gas turbine rotor blade comprising a through-hole penetrating in an arc shape and opened to the outside.

6. The gas turbine rotor blade according to claim 5 , wherein a plate-like member as the hard material member is joined to the surface of the contact surface along the concave portion of the concavo-convex portion fitted to the adjacent rotor blade. The gas turbine rotor blade according to claim 1, wherein the through-hole has not reached the plate-like member.