JP4610722B2

JP4610722B2 - Gas turbine steam cooling system

Info

Publication number: JP4610722B2
Application number: JP2000360800A
Authority: JP
Inventors: 知佳田中; 康治平本
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Ltd
Priority date: 2000-11-28
Filing date: 2000-11-28
Publication date: 2011-01-12
Anticipated expiration: 2020-11-28
Also published as: JP2002161756A

Description

【０００１】
【発明の属する技術分野】
本発明は、ガスタービンの燃焼器等の高温部品に排熱回収ボイラからの蒸気または補助経路からの流体を導入して温度制御するガスタービンの蒸気冷却装置に関する。
【０００２】
【従来の技術】
エネルギー資源の有効利用と経済性の観点から、発電設備（発電プラント）では様々な高効率化が図られている。ガスタービンと蒸気タービンを組み合わせたタービン発電プラント（複合発電プラント）もその一つである。複合発電プラントでは、ガスタービンからの高温の排気ガスが排熱回収ボイラに送られ、排熱回収ボイラ内で過熱ユニットを介して蒸気を発生させ、発生した蒸気を蒸気タービンに送って蒸気タービンで仕事をするようになっている。
【０００３】
ガスタービンの燃焼器等の高温部品は空気により冷却されていたが、近年の燃焼温度の高温化にともない蒸気により冷却されるようになってきている。複合発電プラントにおいても、燃焼器等の高温部品を蒸気によって冷却するガスタービンを適用し、蒸気タービンと組み合わせて高効率な発電プラントが計画されている。例えば、排熱回収ボイラからの蒸気（中圧蒸気）を燃焼器にバイパスさせて冷却蒸気を燃焼器に導き、温度や圧力等に基づいて冷却蒸気の量を調節して所望量の冷却蒸気を燃焼器に供給するようにしている。そして、冷却後の蒸気は蒸気タービン側に回収している。このため、効率の良い冷却システムが構築された複合発電プラントとなる。
【０００４】
【発明が解決しようとする課題】
従来のガスタービンの蒸気冷却装置は、燃焼器に供給される冷却蒸気の量を調節することで所望量の冷却蒸気を供給しているので、予め決められた流量設定通りに冷却蒸気の量を制御することは可能である。しかし、何らかの異常により、冷却蒸気の量が設定通りであっても燃焼器の出口温度が上昇した場合（計画通りに冷却されない場合）、トリップやランバック等のインターロック機能により燃焼器を保護するようになっている。このため、何らかの異常により燃焼器の出口温度が上昇した場合には、プラント全体の効率が低下してしまうのが現状であった。
【０００５】
本発明は上記状況に鑑みてなされたもので、高温部品の出口側の温度が上昇してもインターロック機能を用いることなく高温部品を保護することができるガスタービンの蒸気冷却装置を提供することを目的とする。
【０００６】
【課題を解決するための手段】
上記目的を達成するための本発明のガスタービンの蒸気冷却装置の構成は、ガスタービンの排気ガスによって蒸気を発生させる排熱回収ボイラと、排熱回収ボイラで発生した蒸気により作動する蒸気タービンと、排熱回収ボイラからの蒸気を蒸気タービンに導入する蒸気導入路と、蒸気導入路に備えられ排熱回収ボイラからの蒸気をガスタービンの高温部品の冷却のためにバイパスする蒸気冷却路と、排熱回収ボイラで発生する蒸気圧力を検出する発生蒸気圧力検出手段と、排熱回収ボイラで発生する蒸気圧力を調整するために発生蒸気圧力検出手段の検出情報に基づいて蒸気導入路の蒸気の流量を制御する発生蒸気圧力制御弁と、蒸気冷却路に設けられ蒸気冷却路に導入される蒸気量を制御する蒸気量制御弁と、高温部品の後流側における蒸気冷却路に備えられ高温部品を冷却した後の蒸気温度を検出する冷却後蒸気温度検出手段と、ガスタービンの状態に基づいて蒸気冷却路に流入する蒸気流量を調整するために発生蒸気圧力検出手段の検出値が設定値になるように発生蒸気圧力制御弁の開閉制御を行うと共に冷却後蒸気温度検出手段の検出情報に基づいて蒸気冷却路に流入する蒸気流量を調整するために発生蒸気圧力制御弁及び蒸気量制御弁の開閉制御を行う制御手段とを備えたガスタービンの蒸気冷却装置において、
前記排熱回収ボイラの高圧ドラムからの蒸気が導入される補助蒸気導入路が蒸気冷却路につなげられ、補助蒸気導入路に補助蒸気圧力制御弁を設けて発生蒸気圧力制御弁とし、制御手段には、冷却後蒸気温度検出手段の検出情報に基づいて補助蒸気導入路の流量を制御して蒸気冷却路の流量を確保するように補助蒸気圧力制御弁の開閉制御を行なう機能が備えられていることを特徴とする。
【０００７】
また、上記目的を達成するための本発明のガスタービンの蒸気冷却装置の構成は、ガスタービンの排気ガスによって蒸気を発生させる排熱回収ボイラと、排熱回収ボイラで発生した蒸気により作動する蒸気タービンと、排熱回収ボイラからの蒸気を蒸気タービンに導入する蒸気導入路と、蒸気導入路に備えられ排熱回収ボイラからの蒸気をガスタービンの高温部品の冷却のためにバイパスする蒸気冷却路と、排熱回収ボイラで発生する蒸気圧力を検出する発生蒸気圧力検出手段と、排熱回収ボイラで発生する蒸気圧力を調整するために発生蒸気圧力検出手段の検出情報に基づいて蒸気導入路の蒸気の流量を制御する発生蒸気圧力制御弁と、蒸気冷却路に設けられ蒸気冷却路に導入される蒸気量を制御する蒸気量制御弁と、高温部品の後流側における蒸気冷却路に備えられ高温部品を冷却した後の蒸気温度を検出する冷却後蒸気温度検出手段と、ガスタービンの状態に基づいて蒸気冷却路に流入する蒸気流量を調整するために発生蒸気圧力検出手段の検出値が設定値になるように発生蒸気圧力制御弁の開閉制御を行うと共に冷却後蒸気温度検出手段の検出情報に基づいて蒸気冷却路に流入する蒸気流量を調整するために発生蒸気圧力制御弁及び蒸気量制御弁の開閉制御を行う制御手段とを備えたガスタービンの蒸気冷却装置において、
前記排熱回収ボイラの中圧ドラムから中圧蒸気タービンへの蒸気導入路から分岐されて蒸気冷却路が設けられ、高圧ドラムからの蒸気が導入される補助蒸気導入路が蒸気冷却路につなげられ、蒸気冷却路の分岐部の後流側の蒸気導入路に中圧ドラム圧力制御弁を設けて発生蒸気圧力制御弁とすると共に、補助蒸気導入路に補助蒸気圧力制御弁を設けて発生蒸気圧力制御弁とし、制御手段には、冷却後蒸気温度検出手段の検出情報に基づいて蒸気導入路の流量を規制して蒸気冷却路の流量を確保するように中圧ドラム圧力制御弁の開閉制御を行なうと共に冷却後蒸気温度検出手段の検出情報に基づいて補助蒸気導入路の流量を制御して蒸気冷却路の流量を確保するように補助蒸気圧力制御弁の開閉制御を行なう機能が備えられていることを特徴とする。
【００１２】
【発明の実施の形態】
図１には本発明の第１実施形態例に係るガスタービンの蒸気冷却装置を備えた複合発電プラントの冷却系統を表す概略系統を示してある。
【００１３】
図に示すように、ガスタービン１からの排気ガスが排熱回収ボイラ２に送られるようになっており、排熱回収ボイラ２には、高圧ドラム３、高圧過熱器４及び中圧ドラム５、中圧過熱器６、再熱器７が備えられている。高圧ドラム３で発生した蒸気は高圧蒸気導入路８により高圧過熱器４を経て高圧蒸気タービン９に送られる。中圧ドラム５の蒸気は中圧蒸気導入路１０により中圧過熱器６及び再熱器７を順次経て中圧蒸気タービン１１へ送られる。
【００１４】
高圧蒸気タービン９の出口蒸気は再熱器７の入口側の中圧蒸気導入路１０に合流し、再熱器７を通過した蒸気は中圧蒸気タービン１１へ送られる。中圧過熱器６と再熱器７の間における中圧蒸気導入路１０には中圧ドラム圧力制御弁１２が設けられ、中圧ドラム圧力制御弁１２の開閉制御により中圧ドラム５の蒸気圧力が所定状態に調整される。尚、図中の符号で２０は復水器である。
【００１５】
中圧過熱器６と中圧ドラム圧力制御弁１２の間における中圧蒸気導入路１０からは蒸気冷却路１４が分岐して設けられ、蒸気冷却路１４はガスタービン１の高温部品である燃焼器１３を経て再熱器７の下流側の中圧蒸気導入路１０に合流している。つまり、燃焼器１３には、蒸気冷却路１４から中圧ドラム５の出口蒸気（例えば300 ℃) が冷却蒸気となって供給され、冷却に使用された蒸気（例えば560 ℃〜600 ℃) は再熱器７の出口蒸気と合流して中圧蒸気タービン１１に導かれる。燃焼器１３の出口側の蒸気冷却路１４には蒸気量制御弁としての制御弁１５が設けられ、中圧ドラム圧力制御弁１２及び制御弁１５の開閉により燃焼器１３に導かれる蒸気量が調節される。尚、制御弁１５は燃焼器１３の入口側の蒸気冷却路１４に設けられることもある。燃焼器１３と制御弁１５の間における蒸気冷却路１４には冷却後蒸気温度検出手段としての出口温度検出手段T2が設けられ、出口温度検出手段T2の検出情報に基づいて中圧ドラム圧力制御弁１２及び制御弁１５が開閉制御される（制御手段）。
【００１６】
中圧ドラム圧力制御弁１２及び制御弁１５は、冷却蒸気の圧力や温度、中圧ドラム５の圧力等に基づいて開閉制御され、所定量の蒸気が蒸気冷却路１４に供給されるようになっている。即ち、蒸気冷却路１４から中圧ドラム５の出口蒸気（例えば300 ℃) が冷却蒸気となって燃焼器１３に供給され、燃焼器１３の冷却が行われる。燃焼器１３に導かれる蒸気量は中圧ドラム圧力制御弁１２及び制御弁１５により調節され、所望量の蒸気が燃焼器１３に供給される。燃焼器１３を冷却した後の蒸気は中圧蒸気タービン１１にに回収されるようになっている。このため、効率の良い冷却システムが構築された複合発電プラントとなる。
【００１７】
また、中圧ドラム圧力制御弁１２及び制御弁１５が所定の状態に制御されて冷却蒸気の量が計画通り供給されている時に、何らかの異常により、燃焼器１３の出口側の温度が上昇したことが出口温度検出手段T2で検出された場合、温度上昇に応じて中圧ドラム圧力制御弁１２及び制御弁１５が制御されて冷却蒸気量が増加される。つまり、出口温度検出手段T2で検出された温度に応じて中圧ドラム圧力制御弁１２が閉側に制御されて蒸気冷却路１４に供給される冷却蒸気の量が増加され、制御弁１５が開側に制御されて蒸気冷却路１４を流通する冷却蒸気の量が増加される。中圧ドラム圧力制御弁１２及び制御弁１５の開閉制御は、温度上昇の度合いに応じて開閉量を増したり、中圧ドラム圧力制御弁１２を強制的に全閉状態にしたり、制御弁１５を強制的に全開状態にすることが実施される。
【００１８】
これにより、何らかの異常により燃焼器１３に供給される冷却蒸気の温度が上昇して損傷等の虞が生じた場合に、燃焼器１３に送られる冷却蒸気の流量を増加して燃焼器１３を保護することが可能になる。従って、燃焼器１３の出口側の温度が上昇してもインターロック機能を用いることなく燃焼器１３を保護することができる蒸気冷却装置となる。
【００１９】
本発明の第２実施形態例を図２乃至図５に基づいて説明する。図２には本発明の第２実施形態例に係るガスタービンの蒸気冷却装置を備えた複合発電プラントの概略構成、図３、図４には発生蒸気圧力制御弁の制御ブロック、図５には蒸気量制御弁の制御ブロックを示してある。
【００２０】
図２に示すように、ガスタービン１０１からの排気ガスが排熱回収ボイラ１０２に送られるようになっており、排熱回収ボイラ１０２には、高圧ドラム１０３及び第１高圧過熱器１０４、第２高圧過熱器１０５が備えられていると共に、中圧ドラム１０６、中圧過熱器１０７及び再熱器１０８が備えられている。高圧ドラム１０３で発生した蒸気は第１高圧過熱器１０４、第２高圧過熱器１０５を経て高圧側蒸気導入路１０９から高圧蒸気タービン１１０に送られる。高圧蒸気タービン１１０の排気蒸気は再熱器１０８を経て蒸気導入路１１１から中圧蒸気タービン１１２に送られる。そして、中圧蒸気タービン１１２の排気蒸気は低圧蒸気タービン１１３に送られ、復水器１１４で復水されて排熱回収ボイラ１０２側に回収される。一方、中圧ドラム１０６の蒸気は蒸気導入路としての中圧側蒸気導入路１１５から中圧過熱器１０７及び再熱器１０８を順次経て中圧蒸気タービン１１２に送られる。
【００２１】
中圧側蒸気導入路１１５から分岐して蒸気冷却路としての蒸気流路１１６が設けられ、蒸気流路１１６はガスタービン１０１の高温部品である燃焼器１１７を経てバイパスし、中圧蒸気タービン１１２の入口側における蒸気導入路１１１に合流している。燃焼器１１７の出口側における蒸気流路１１６には蒸気量制御弁２０１が設けられ、蒸気量制御弁２０１の開閉により蒸気流路１１６の蒸気量が調整される。尚、蒸気量制御弁２０１は燃焼器１１７の入口側における蒸気流路１１６に設けられることもある。また、第２高圧過熱器１０５の後流側の高圧側蒸気導入路１０９から分岐して高圧蒸気流路１１８が設けられ、高圧蒸気流路１１８はガスタービン１０１の前側における蒸気流路１１６に合流している。高圧蒸気流路１１８には中圧給水ポンプからの給水が導入される補助流体流路１１９が合流している。
【００２２】
蒸気流路１１６の分岐部の後流側における中圧側蒸気導入路１１５には第１流量制御弁１２０が設けられ、第１流量制御弁１２０の開閉により中圧側蒸気導入路１１５を流通する蒸気量が調整される。また、補助流体流路１１９の合流部の前流側における高圧蒸気流路１１８には第２流量制御弁１２１が設けられ、第２流量制御弁１２１の開閉により高圧蒸気流路１１８から蒸気流路１１６に導入される高圧蒸気の流量が調整される。即ち、蒸気流路１１６の蒸気の温度が調整される。更に、補助流体流路１１９には補助流体圧力制御弁としての第３流量制御弁１２２が設けられ、第３流量制御弁１２２の開閉により高圧蒸気流路１１８に適宜量の中圧給水が導入されて高圧蒸気流路１１８内の蒸気が減温され、蒸気流路１１６に導入される高圧蒸気の温度が所定温度に制御される。
【００２３】
高圧蒸気流路１１８の合流部とガスタービン１０１との間における蒸気流路１１６には温度検出手段T1が設けられ、温度検出手段T1によりガスタービン１０１に導入される蒸気の温度が検出される。蒸気流路１１６の燃焼器１１７の入口側と出口側の蒸気圧力差を検出する差圧検出手段P1が設けられ、差圧検出手段P1により燃焼器１１７を流通する蒸気の差圧、即ち、流量が検出される。また、補助流体流路１１９の合流部の後流側における高圧蒸気流路１１８には補助蒸気温度検出手段としての第２温度検出手段T3が設けられ、第２温度検出手段T3により高圧蒸気流路１１８の蒸気温度が検出される。尚、図中の符号で、P2は蒸気流路１１６の燃焼器１１７の入口側の蒸気圧力を検出する入口圧力検出手段、P3は蒸気流路１１６の燃焼器１１７の出口側の蒸気圧力を検出する出口圧力検出手段、T2は蒸気流路１１６の燃焼器１１７の出口側の蒸気温度を検出する冷却後蒸気温度検出手段としての出口温度検出手段である。また、燃焼器１１７の入口側には燃焼器１１７の車室圧を検出する車室圧検出手段P4が設けられている。
【００２４】
温度検出手段T1、差圧検出手段P1及び第２温度検出手段T3、入口圧力検出手段P2、出口圧力検出手段P3、出口温度検出手段T2及び車室圧検出手段P4の検出情報は制御手段１２５に入力される。また、制御手段１２５にはガスタービン１の出力MWが入力される。制御手段１２５からは、第１流量制御弁１２０、第２流量制御弁１２１、第３流量制御弁１２２及び蒸気量制御弁２０１に開閉指令が出力される。
【００２５】
差圧検出手段P1の検出情報に応じて（差圧に応じて）第１流量制御弁１２０を開閉させることにより、中圧蒸気タービン１１２側への蒸気の流通が規制されて燃焼器１１７を流通する蒸気流量が適正に制御される。また、差圧検出手段P1及び温度検出手段T1の検出情報に応じて第２流量制御弁１２１を開閉させると共に、第２温度検出手段T3の検出情報に応じて第３流量制御弁１２２を開閉させることにより、燃焼器１１７を流通する蒸気量が適正流量を保った状態で適正に制御される。また、車室圧検出手段P4の検出情報に応じて蒸気量制御弁２０１を開閉させることにより、燃焼器１１７を流通する蒸気流量が適正に制御される。
【００２６】
この時、燃焼器１１７を流通する蒸気量が適正を保っているにも拘らず何らかの異常により蒸気温度が上昇した場合（燃焼器１１７が計画通り冷却されない場合）、出口温度検出手段T2の検出情報に応じて、第１流量制御弁１２０、第２流量制御弁１２１、第３流量制御弁１２２及び蒸気量制御弁２０１が開閉され、蒸気流路１１６の蒸気量が増やされて燃焼器１１７を流通する蒸気温度の過上昇が防止される。
【００２７】
つまり、制御手段１２５では、燃焼器１１７の必要冷却蒸気量が演算されると共に必要冷却蒸気量に見合った差圧が演算され、差圧検出手段P1の検出値が演算された差圧となるように第１流量制御弁１２０に開閉指令を出力する。これにより、燃焼器１１７には必要冷却蒸気量が供給される。また、制御手段１２５では、ガスタービン１０１の必要蒸気温度が演算されると共に温度検出手段T1の検出値が演算された温度となるように第２流量制御弁１２１に開閉指令を出力する。このとき、制御手段１２５では、蒸気流路１１６に導入される蒸気温度（第２温度検出手段T3の検出情報及び温度検出手段T1の検出情報）に基づいて第３流量制御弁１２２に開閉指令が出力され、中圧給水の量が適宜制御されて高圧蒸気流路１１８の蒸気温度が所定温度に減温される。また、制御手段１２５では、燃焼器１１７の車室圧に応じて蒸気量制御弁２０１に開閉指令を出力する。
【００２８】
温度制御により燃焼器１１７を流通する蒸気流量が増減すると、差圧検出手段P1の検出情報により第１流量制御弁１２０が開閉制御され、規定の蒸気流量が確保されているが、負荷変動等により中圧蒸気の発生遅れ等が生じ、蒸気流路１１６を流通する蒸気の絶対流量が不足した場合は、温度制御に優先して、差圧検出手段P1の検出値が演算された差圧となるように第２流量制御弁１２１が開閉制御され、高圧蒸気を導入することで蒸気流量を確保する（バックアップ制御）。即ち、第２流量制御弁１２１には差圧制御においても開閉指令が出力され、温度制御による開度指令と、差圧制御による開度指令の高い値を選択して第２流量制御弁１２１の開度として制御されるようになっている。
【００２９】
上述した蒸気制御装置では、温度の低い中圧ドラム１０６側の発生蒸気と、温度の高い高圧ドラム１０３の発生蒸気とを混合し、混合した蒸気流量及び蒸気温度を適切に制御して燃焼器１１７に導入している。また、混合を最適に行うため、中圧側蒸気導入路１１５に設けられた第１流量制御弁１２０の開閉により蒸気流量が制御され、高圧蒸気流路１１８に設けられた第２流量制御弁１２１の開閉により高圧蒸気流量を調整して蒸気温度が制御されている。また、中圧蒸気が不足した場合には、バックアップ制御により第２流量制御弁１２１を開閉して高圧蒸気を流量確保のために導入するようにしている。更に、燃焼器１１７の車室圧に応じて蒸気量制御弁２０１を開閉して蒸気流路１１６を流通する蒸気の流量が制御されている。このため、燃焼器１１７に導かれる蒸気流量を適切に制御することが可能になる。
【００３０】
図３乃至図５に基づいて第１流量制御弁１２０、第２流量制御弁１２１及び蒸気量制御弁２０１の制御状況を詳細に説明する。図３には第１流量制御弁１２０の制御ブロック構成、図４には第２流量制御弁１２１の制御ブロック構成、図５には蒸気量制御弁２０１の制御ブロック構成を示してある。
【００３１】
図３に示すように、制御手段１２５の演算手段１４１には、温度検出手段T1、入口圧力検出手段P2、出口圧力検出手段P3及び出口温度検出手段T2の検出情報が入力される。また、変換演算手段１４２にはガスタービン１０１の出力MWが入力され、変換演算手段１４２では出力MWが、要求されるバックアップ用蒸気流量として変換されて加算手段１５１に入力される。一方、出口温度検出手段T2の検出情報に基づいて温度に応じたバイアスが関数手段１５０で演算されて加味され、温度に応じて加味されたバイアス値が加算手段１５１でガスタービン１０１の出力MWに加算される。ガスタービン１０１の出力MWとバイアス値とが加算された情報が変換演算手段１４２に入力され、変換演算手段１４２でバイアス値が加算された出力MWが、要求される冷却蒸気流量として変換されて演算手段１４１に入力される。
【００３２】
具体的に要求される冷却蒸気流量は、出口温度検出手段T2で検出される蒸気温度が高くになるにしたがって多くなるようにバイアス値が設定されている。即ち、出口温度検出手段T2で検出される蒸気温度が高くになるにしたがって第１流量制御弁１２０が閉側に作動されて蒸気流路１１６に送られる蒸気量が多くなるように制御される。演算手段１４１では入力情報を差圧相当値に変換して加算手段１４３に出力し、加算手段１４３には差圧検出手段P1の検出情報が入力される。加算手段１４３では、演算手段１４１からの差圧相当値の情報と差圧検出手段P1の検出情報との差を求め、PI演算手段１４４では求められた差分を０側情報の開度指令として、０側情報を選択手段１５２に送る。選択手段１５２には全閉指令（最小開度、例えば３％乃至５％の開度）が指令手段１５３から１側情報として送られている。
【００３３】
選択手段１５２は通常はオフにされ、比較手段１５４からの指令があった際にオンになる。即ち、選択手段１５２は、オンになることで０側情報から１側情報に出力指令が切り換えられるようになっており、オフの場合、０側情報の開度指令（ガスタービン１０１の出力MW及び蒸気流路１１６の状況に応じた開度指令）が第１流量制御弁１２０に出力され、オンの場合、１側情報の開度指令（全閉指令）が第１流量制御弁１２０に出力される。比較手段１５４には出口温度検出手段T2の検出情報が入力され、比較手段１５４の結果が選択手段１５２に送られる。比較手段１５４で出口温度検出手段T2の検出情報が所定値（上限値）を越えているとされた場合、比較手段１５４から選択手段１５２にオン信号が出され、選択手段１５２が１側情報の開度指令に切り換えられる。
【００３４】
従って、第１流量制御弁１２０は、ガスタービン１０１の出力MW及び蒸気流路１１６の状況の検出情報に基づいて蒸気流路１１６の蒸気量が所定流量となるように開閉が制御されると共に、出口温度検出手段T2で検出される蒸気温度に応じて、燃焼器１１７の出口側の温度が高くなった際には温度上昇分蒸気流路１１６の蒸気量が増加するように閉側に制御される。更に、第１流量制御弁１２０は、出口温度検出手段T2の検出情報が所定値（上限値）を越えた場合には全閉指令（最小開度指令）により全閉状態とされ、中圧ドラム１０６からの蒸気が蒸気流路１１６に全量送られる。
【００３５】
図４に示すように、制御装置１２５の演算手段１４１には、温度検出手段T1、入口圧力検出手段P2、出口圧力検出手段P3及び出口温度検出手段T2の検出情報が入力される。また、第２変換演算手段１４５にはガスタービン１０１の出力MWが入力され、第２変換演算手段１４５では出力MWが、要求されるバックアップ用蒸気流量として変換されて加算手段１６２に入力される。一方、出口温度検出手段T2の検出情報に基づいて温度に応じたバイアスが関数手段１６１で演算されて加味され、温度に応じて加味されたバイアス値が加算手段１６２でガスタービン１０１の出力MWに加算される。ガスタービン１０１の出力MWとバイアス値とが加算された情報が演算手段１４１に入力され、第２変換演算手段１４５でバイアス値が加算された出力MWが、要求される冷却蒸気流量として変換されて演算手段１４１に入力される。
【００３６】
そして、演算手段１４１では入力情報が差圧相当値に変換され加算手段１４３に出力され、加算手段１４３には差圧検出手段P1の検出情報が入力される。加算手段１４３では、演算手段１４１からの差圧相当値の情報と差圧検出手段P1の検出情報との差を求め、PI演算手段１４４では求められた差分を開度指令として演算する。
【００３７】
具体的に要求される冷却蒸気流量は、出口温度検出手段T2で検出される蒸気温度が高くになるにしたがって多くなるようにバイアス値が設定されている。即ち、出口温度検出手段T2で検出される蒸気温度が高くになるにしたがって第２流量制御弁１２１が開側に作動されて高圧蒸気流路１１８から蒸気流路１１６に送られる蒸気量が多くなるように制御される。
【００３８】
従って、第２流量制御弁１２１は、ガスタービン１０１の出力MW及び蒸気流路１１６の状況の検出情報に基づいて蒸気流路１１６の蒸気量が所定流量となるように開閉が制御されると共に、出口温度検出手段T2で検出される蒸気温度に応じて、燃焼器１１７の出口側の温度が高くなった際には温度上昇分蒸気流路１１６の蒸気量が増加するように開側に制御される。
【００３９】
図５に示すように、制御装置１２５の加算手段２１０には指令手段２１１からの指令情報と車室圧検出手段P4の検出情報が入力される。加算手段２１０からの情報は加算手段２１２で出口圧力検出手段P3の検出情報が加算される。これらの情報に基づいてPI演算手段２１３では蒸気量制御弁２０１の開度指令が演算される。PI演算手段２１３では求められた開度指令を０側情報として、０側情報を選択手段２１４に送る。選択手段１５２には全開指令が指令手段２１５から１側情報として送られている。
【００４０】
選択手段２１５は通常はオフにされ、比較手段２１６からの指令があった際にオンになる。即ち、選択手段２１５は、オンになることで０側情報から１側情報に出力指令が切り換えられるようになっており、オフの場合、０側情報の開度指令（車室圧力及び燃焼器１１７の出口側圧力に応じた開度指令）が蒸気量制御弁２０１に出力され、オンの場合、１側情報の開度指令（全開指令）が蒸気量制御弁２０１にに出力される。比較手段２１６には出口温度検出手段T2の検出情報が入力され、比較手段２１６の結果が選択手段２１４に送られる。比較手段２１６で出口温度検出手段T2の検出情報が所定値（上限値）を越えているとされた場合、比較手段２１６から選択手段２１５にオン信号が出され、選択手段２１４が１側情報の開度指令に切り換えられる。
【００４１】
従って、燃焼器１１７の出口側の温度が上昇して出口温度検出手段T2で検出される蒸気温度が所定値（上限値）を越えた場合には、蒸気量制御弁２０１が全開となって冷却用蒸気が増量される。これにより、所定量に冷却蒸気量が制御されているにも拘らず冷却蒸気温度が上昇して所定値（上限値）を越えた場合も、冷却蒸気量が増量されるようになっている。
【００４２】
このため、燃焼器１１７の出口側の温度が高くなった際には、出口温度検出手段T2で検出される蒸気温度が高くになるにしたがって冷却用蒸気が増量されると共に、出口温度検出手段T2の検出情報が所定値（上限値）を越えた場合には、中圧ドラム１０６からの蒸気が蒸気流路１１６に全量送られると共に蒸気量制御弁２０１が全開となって冷却用蒸気が増量される。これにより、所定量に冷却蒸気量が制御されているにも拘らず冷却蒸気温度が上昇しても、燃焼器１１７が保護されるようになっている。
【００４３】
従って、何らかの異常により燃焼器１１７に供給される冷却蒸気の温度が上昇して損傷等の虞が生じた場合に、燃焼器１１７に送られる冷却蒸気の流量を増加して燃焼器１１７を保護することが可能になる。従って、燃焼器１１７の出口側の温度が上昇してもインターロック機能を用いることなく燃焼器１１７を保護することができる蒸気冷却装置となる。
【００４４】
燃焼器１１７の出口側の温度が高くなった際における第１流量制御弁１２０及び第２流量制御弁１２１の開閉制御は、例えば、第１流量制御弁１２０の閉動作により中圧ドラム１０６からの蒸気を蒸気流路１１６に送り、第１流量制御弁１２０を全閉状態にしても燃焼器１１７の出口側の温度が高い場合に第２流量制御弁１２１を開動作させて高圧蒸気流路１１８側からの蒸気量を増量するようになっている。そして、燃焼器１１７の出口側の温度が所定値（上限値）を越えた場合に蒸気量制御弁２０１を全開にして冷却用蒸気を増量する。尚、第１流量制御弁１２０及び第２流量制御弁１２１の開閉制御の状況は、設備の能力等により適宜設定され、所定流量の確保と所定温度の確保が両立できるように他の制御弁との開閉と組み合わせて実施される。また、蒸気量制御弁２０１の開閉制御は、燃焼器１１７の出口側の温度が所定値（上限値）を越える前に上昇した温度に応じて適宜開閉し、所定値（上限値）を越えたときに全開にするようにしてもよい。
【００４５】
【発明の効果】
本発明のガスタービンの蒸気冷却装置は、ガスタービンの排気ガスによって蒸気を発生させる排熱回収ボイラと、排熱回収ボイラで発生した蒸気により作動する蒸気タービンと、排熱回収ボイラからの蒸気を蒸気タービンに導入する蒸気導入路と、蒸気導入路に備えられ排熱回収ボイラからの蒸気をガスタービンの高温部品の冷却のためにバイパスする蒸気冷却路と、蒸気冷却路に設けられ蒸気冷却路に導入される蒸気量を制御する蒸気量制御弁と、高温部品の後流側における蒸気冷却路に備えられ高温部品を冷却した後の蒸気温度を検出する冷却後蒸気温度検出手段と、冷却後蒸気温度検出手段の検出情報に基づいて蒸気冷却路に流入する蒸気流量を調整するために蒸気量制御弁の開閉制御を行うと共に蒸気冷却路に流入する蒸気流量を所定状態に制御する制御手段とを備えたので、冷却後蒸気温度が高くなった際には高温部品に導かれる蒸気流量を増量するように蒸気量制御弁を制御することで冷却蒸気量が増量して高温部品の保護が可能になる。この結果、高温部品の出口側の温度が上昇してもインターロック機能を用いることなく高温部品が保護され、高温部品の破損等を防止することができる。
【００４６】
また、本発明のガスタービンの蒸気冷却装置は、ガスタービンの排気ガスによって蒸気を発生させる排熱回収ボイラと、排熱回収ボイラで発生した蒸気により作動する蒸気タービンと、排熱回収ボイラからの蒸気を蒸気タービンに導入する蒸気導入路と、蒸気導入路に備えられ排熱回収ボイラからの蒸気をガスタービンの高温部品の冷却のためにバイパスする蒸気冷却路と、排熱回収ボイラで発生する蒸気圧力を検出する発生蒸気圧力検出手段と、排熱回収ボイラで発生する蒸気圧力を調整するために発生蒸気圧力検出手段の検出情報に基づいて蒸気導入路の蒸気の流量を制御する発生蒸気圧力制御弁と、蒸気冷却路に設けられ蒸気冷却路に導入される蒸気量を制御する蒸気量制御弁と、高温部品の後流側における蒸気冷却路に備えられ高温部品を冷却した後の蒸気温度を検出する冷却後蒸気温度検出手段と、ガスタービンの状態に基づいて蒸気冷却路に流入する蒸気流量を調整するために発生蒸気圧力検出手段の検出値が設定値になるように発生蒸気圧力制御弁の開閉制御を行うと共に冷却後蒸気温度検出手段の検出情報に基づいて蒸気冷却路に流入する蒸気流量を調整するために発生蒸気圧力制御弁及び蒸気量制御弁の開閉制御を行う制御手段とを備えたので、冷却後蒸気温度が高くなった際には高温部品に導かれる蒸気流量を増量するように発生蒸気圧力制御弁及び蒸気量制御弁を制御することで冷却蒸気量を増量して高温部品の保護が可能になる。この結果、高温部品の出口側の温度が上昇してもインターロック機能を用いることなく高温部品が保護され、高温部品の破損等を防止することができる。
【００４７】
また、中圧ドラムから中圧蒸気タービンへの蒸気導入路から分岐されて蒸気冷却路が設けられ、蒸気冷却路の分岐部の後流側の蒸気導入路に中圧ドラム圧力制御弁を設けて発生蒸気圧力制御弁とし、制御手段には、冷却後蒸気温度検出手段の検出情報に基づいて蒸気導入路の流量を規制して蒸気冷却路の流量を確保するように中圧ドラム圧力制御弁の開閉制御を行なう機能が備えられているので、中圧ドラムからの蒸気を蒸気冷却路に送ることができる。
【００４８】
また、高圧ドラムからの蒸気が導入される補助蒸気導入路が蒸気冷却路につなげられ、補助蒸気導入路に補助蒸気圧力制御弁を設けて発生蒸気圧力制御弁とし、制御手段には、冷却後蒸気温度検出手段の検出情報に基づいて補助蒸気導入路の流量を制御して蒸気冷却路の流量を確保するように補助蒸気圧力制御弁の開閉制御を行なう機能が備えられているので、高圧ドラムからの蒸気を蒸気冷却路に送ることができる。
【００４９】
また、中圧ドラムから中圧蒸気タービンへの蒸気導入路から分岐されて蒸気冷却路が設けられ、高圧ドラムからの蒸気が導入される補助蒸気導入路が蒸気冷却路につなげられ、蒸気冷却路の分岐部の後流側の蒸気導入路に中圧ドラム圧力制御弁を設けて発生蒸気圧力制御弁とすると共に、補助蒸気導入路に補助蒸気圧力制御弁を設けて発生蒸気圧力制御弁とし、制御手段には、冷却後蒸気温度検出手段の検出情報に基づいて蒸気導入路の流量を規制して蒸気冷却路の流量を確保するように中圧ドラム圧力制御弁の開閉制御を行なうと共に冷却後蒸気温度検出手段の検出情報に基づいて補助蒸気導入路の流量を制御して蒸気冷却路の流量を確保するように補助蒸気圧力制御弁の開閉制御を行なう機能が備えられているので、中圧ドラムからの蒸気及び高圧ドラムからの蒸気及び補助蒸気を蒸気冷却路に送ることができる。
【００５０】
また、制御手段には、冷却後蒸気温度検出手段により蒸気温度が上限値を越えたことが検出されたときに蒸気流量制御弁を全開に制御する機能が備えられているので、蒸気温度が上限値を越えたときには最大量を蒸気冷却路に通すことができる。
【図面の簡単な説明】
【図１】本発明の第１実施形態例に係るガスタービンの蒸気冷却装置を備えた複合発電プラントの冷却系統を表す概略系統図。
【図２】本発明の第２実施形態例に係るガスタービンの蒸気冷却装置を備えた複合発電プラントの概略構成図。
【図３】発生蒸気圧力制御弁の制御ブロック図。
【図４】発生蒸気圧力制御弁の制御ブロック図。
【図５】蒸気量制御弁の制御ブロック図。
【符号の説明】
１，１０１ガスタービン
２，１０２排熱回収ボイラ
３，１０３高圧ドラム
４高圧過熱器
５，１０６中圧ドラム
６，１０７中圧過熱器
７，１０８再熱器
８，１０９高圧蒸気導入路
９，１１０高圧蒸気タービン
１０，１１５中圧蒸気導入路
１１，１１２中圧蒸気タービン
１２中圧ドラム圧力制御弁
１３，１１７燃焼器
１４，蒸気冷却路
１５蒸気流量制御弁
２０，１１４復水器
１１６蒸気流路
１１８高圧蒸気流路
１１９補助流体流路
１２０第１流量制御弁
１２１第２流量制御弁
１２２第３流量制御弁
１２５制御手段
１４１演算手段
１４２変換演算器
１４３，１５１、１６２，２１０，２１２加算手段
１４４，２１３ PI演算手段
１４５第２変換演算手段
１５０，１６１関数手段
１５２，２１４選択手段
１５３，２１５指令手段
１５４，２１６比較手段[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a steam cooling device for a gas turbine that controls the temperature by introducing steam from an exhaust heat recovery boiler or fluid from an auxiliary path into a high-temperature component such as a combustor of the gas turbine.
[0002]
[Prior art]
From the viewpoint of effective use of energy resources and economic efficiency, various efficiency improvements have been made in power generation facilities (power generation plants). One example is a turbine power plant (combined power plant) that combines a gas turbine and a steam turbine. In a combined power plant, high-temperature exhaust gas from a gas turbine is sent to an exhaust heat recovery boiler, and steam is generated in the exhaust heat recovery boiler via an overheating unit. I am going to work.
[0003]
High-temperature components such as a combustor of a gas turbine have been cooled by air. However, as the combustion temperature increases in recent years, it has been cooled by steam. In a combined power plant, a gas turbine that cools high-temperature parts such as a combustor with steam is applied, and a high-efficiency power plant is planned in combination with the steam turbine. For example, by bypassing the steam (medium pressure steam) from the exhaust heat recovery boiler to the combustor and guiding the cooling steam to the combustor, the amount of the cooling steam is adjusted based on temperature, pressure, etc. Supply to the combustor. Then, the cooled steam is collected on the steam turbine side. For this reason, it becomes a combined power plant in which an efficient cooling system is constructed.
[0004]
[Problems to be solved by the invention]
Since the conventional gas turbine steam cooling system supplies a desired amount of cooling steam by adjusting the amount of cooling steam supplied to the combustor, the amount of cooling steam is adjusted according to a predetermined flow rate setting. It is possible to control. However, if the combustor outlet temperature rises due to some abnormality even if the amount of cooling steam is as set (if it is not cooled as planned), the combustor is protected by an interlock function such as trip or runback. It is like that. For this reason, when the exit temperature of the combustor rises due to some abnormality, the current efficiency of the entire plant is lowered.
[0005]
The present invention has been made in view of the above situation, and provides a steam cooling device for a gas turbine that can protect a high-temperature component without using an interlock function even if the temperature of the outlet side of the high-temperature component rises. With the goal.
[0006]
[Means for Solving the Problems]
  In order to achieve the above object, the structure of the steam cooling device for a gas turbine of the present invention includes an exhaust heat recovery boiler that generates steam by exhaust gas of the gas turbine, and a steam turbine that is operated by the steam generated in the exhaust heat recovery boiler, A steam introduction path for introducing the steam from the exhaust heat recovery boiler into the steam turbine; a steam cooling path for bypassing the steam from the exhaust heat recovery boiler provided for the steam introduction path for cooling the high-temperature components of the gas turbine;The generated steam pressure detecting means for detecting the steam pressure generated in the exhaust heat recovery boiler, and the steam in the steam introduction path based on the detection information of the generated steam pressure detecting means for adjusting the steam pressure generated in the exhaust heat recovery boiler. A generated steam pressure control valve for controlling the flow rate;A steam amount control valve that is provided in the steam cooling path and controls the amount of steam introduced into the steam cooling path, and a cooling that is provided in the steam cooling path on the downstream side of the high temperature part and detects the steam temperature after cooling the high temperature part. Post steam temperature detecting means;In order to adjust the flow rate of steam flowing into the steam cooling path based on the state of the gas turbine, the generated steam pressure control valve is controlled to open and close so that the detected value of the generated steam pressure detecting means becomes a set value.To adjust the flow rate of the steam flowing into the steam cooling path based on the detection information of the steam temperature detecting means after coolingGenerated steam pressure control valve andControls the opening and closing of the steam control valveSystemWith meansIn the gas turbine steam cooling system,
  An auxiliary steam introduction path through which steam from the high-pressure drum of the exhaust heat recovery boiler is introduced is connected to a steam cooling path, and an auxiliary steam pressure control valve is provided in the auxiliary steam introduction path to form a generated steam pressure control valve. Has a function of controlling the flow of the auxiliary steam introduction passage based on the detection information of the post-cooling steam temperature detecting means and controlling the opening and closing of the auxiliary steam pressure control valve so as to secure the flow rate of the steam cooling passage.It is characterized by that.
[0007]
  In addition, the configuration of the steam cooling device for a gas turbine of the present invention for achieving the above object includes an exhaust heat recovery boiler that generates steam by the exhaust gas of the gas turbine, and a steam that is operated by the steam generated in the exhaust heat recovery boiler. A steam introduction path for introducing steam from the exhaust heat recovery boiler into the steam turbine, and a steam cooling path for bypassing the steam from the exhaust heat recovery boiler provided in the steam introduction path for cooling high-temperature components of the gas turbine Generated steam pressure detecting means for detecting the steam pressure generated in the exhaust heat recovery boiler, and the steam introduction path based on the detection information of the generated steam pressure detecting means for adjusting the steam pressure generated in the exhaust heat recovery boiler. A generated steam pressure control valve that controls the flow rate of steam, a steam amount control valve that is provided in the steam cooling path and controls the amount of steam introduced into the steam cooling path, and on the downstream side of the high-temperature components A post-cooling steam temperature detecting means for detecting a steam temperature after cooling a high-temperature component provided in the steam cooling path, and a generated steam pressure for adjusting the flow rate of the steam flowing into the steam cooling path based on the state of the gas turbine The generated steam pressure control valve is controlled to open and close so that the detection value of the detection means becomes a set value, and the generated steam is adjusted to adjust the flow rate of the steam flowing into the steam cooling path based on the detection information of the post-cooling steam temperature detection means. Control means for controlling the opening and closing of the pressure control valve and the steam control valveIn the gas turbine steam cooling system,
  A steam cooling path is provided by branching from the steam introduction path from the intermediate pressure drum to the intermediate pressure steam turbine in the exhaust heat recovery boiler, and an auxiliary steam introduction path for introducing steam from the high pressure drum is connected to the steam cooling path. An intermediate-pressure drum pressure control valve is provided in the steam introduction path on the downstream side of the branch of the steam cooling path to form a generated steam pressure control valve, and an auxiliary steam pressure control valve is provided in the auxiliary steam introduction path to generate steam pressure. The control means controls the opening / closing of the intermediate pressure drum pressure control valve so as to secure the flow rate of the steam cooling path by regulating the flow rate of the steam introduction path based on the detection information of the post-cooling steam temperature detection means. And a function of controlling the opening and closing of the auxiliary steam pressure control valve so as to secure the flow rate of the steam cooling path by controlling the flow rate of the auxiliary steam introduction path based on the detection information of the post-cooling steam temperature detecting means.It is characterized by that.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a schematic system representing a cooling system of a combined power plant provided with a steam cooling device for a gas turbine according to a first embodiment of the present invention.
[0013]
As shown in the figure, exhaust gas from the gas turbine 1 is sent to an exhaust heat recovery boiler 2, and the exhaust heat recovery boiler 2 includes a high pressure drum 3, a high pressure superheater 4, an intermediate pressure drum 5, An intermediate pressure superheater 6 and a reheater 7 are provided. The steam generated in the high-pressure drum 3 is sent to the high-pressure steam turbine 9 through the high-pressure superheater 4 through the high-pressure steam introduction path 8. The steam of the intermediate pressure drum 5 is sent to the intermediate pressure steam turbine 11 through the intermediate pressure superheater 6 and the reheater 7 sequentially by the intermediate pressure steam introduction path 10.
[0014]
The outlet steam of the high pressure steam turbine 9 joins the intermediate pressure steam introduction path 10 on the inlet side of the reheater 7, and the steam that has passed through the reheater 7 is sent to the intermediate pressure steam turbine 11. An intermediate pressure drum pressure control valve 12 is provided in the intermediate pressure steam introduction path 10 between the intermediate pressure superheater 6 and the reheater 7, and the steam pressure of the intermediate pressure drum 5 is controlled by opening and closing the intermediate pressure drum pressure control valve 12. Is adjusted to a predetermined state. Reference numeral 20 in the figure denotes a condenser.
[0015]
A steam cooling path 14 is branched from the intermediate pressure steam introduction path 10 between the intermediate pressure superheater 6 and the intermediate pressure drum pressure control valve 12, and the steam cooling path 14 is a combustor that is a high-temperature component of the gas turbine 1. 13 is joined to the intermediate pressure steam introduction passage 10 on the downstream side of the reheater 7. That is, the outlet steam (for example, 300 ° C.) of the intermediate pressure drum 5 is supplied to the combustor 13 as the cooling steam from the steam cooling path 14, and the steam (for example, 560 ° C. to 600 ° C.) used for cooling is recycled. It merges with the outlet steam of the heater 7 and is guided to the intermediate pressure steam turbine 11. The steam cooling path 14 on the outlet side of the combustor 13 is provided with a control valve 15 as a steam control valve, and the amount of steam guided to the combustor 13 is adjusted by opening and closing the intermediate pressure drum pressure control valve 12 and the control valve 15. Is done. The control valve 15 may be provided in the steam cooling path 14 on the inlet side of the combustor 13. The steam cooling path 14 between the combustor 13 and the control valve 15 is provided with an outlet temperature detecting means T2 as a post-cooling steam temperature detecting means, and an intermediate pressure drum pressure control valve based on detection information of the outlet temperature detecting means T2. 12 and the control valve 15 are controlled to open and close (control means).
[0016]
The intermediate pressure drum pressure control valve 12 and the control valve 15 are controlled to open and close based on the pressure and temperature of the cooling steam, the pressure of the intermediate pressure drum 5 and the like, so that a predetermined amount of steam is supplied to the steam cooling path 14. ing. That is, the outlet steam (for example, 300 ° C.) of the intermediate pressure drum 5 is supplied from the steam cooling path 14 to the combustor 13 as cooling steam, and the combustor 13 is cooled. The amount of steam guided to the combustor 13 is adjusted by the intermediate pressure drum pressure control valve 12 and the control valve 15, and a desired amount of steam is supplied to the combustor 13. The steam after cooling the combustor 13 is collected by the intermediate pressure steam turbine 11. For this reason, it becomes a combined power plant in which an efficient cooling system is constructed.
[0017]
Further, when the intermediate pressure drum pressure control valve 12 and the control valve 15 are controlled to a predetermined state and the amount of cooling steam is supplied as planned, the temperature on the outlet side of the combustor 13 has increased due to some abnormality. Is detected by the outlet temperature detecting means T2, the intermediate pressure drum pressure control valve 12 and the control valve 15 are controlled according to the temperature rise, and the amount of cooling steam is increased. That is, the intermediate pressure drum pressure control valve 12 is controlled to close according to the temperature detected by the outlet temperature detection means T2, the amount of cooling steam supplied to the steam cooling path 14 is increased, and the control valve 15 is opened. The amount of the cooling steam that is controlled to the side and flows through the steam cooling path 14 is increased. The opening / closing control of the intermediate pressure drum pressure control valve 12 and the control valve 15 is performed by increasing the opening / closing amount according to the degree of temperature rise, forcing the intermediate pressure drum pressure control valve 12 to be fully closed, Forcing to fully open is performed.
[0018]
As a result, when the temperature of the cooling steam supplied to the combustor 13 rises due to some abnormality and there is a risk of damage or the like, the flow rate of the cooling steam sent to the combustor 13 is increased to protect the combustor 13. It becomes possible to do. Therefore, even if the temperature on the outlet side of the combustor 13 rises, the steam cooling device can protect the combustor 13 without using the interlock function.
[0019]
A second embodiment of the present invention will be described with reference to FIGS. FIG. 2 shows a schematic configuration of a combined power plant equipped with a steam cooling device for a gas turbine according to a second embodiment of the present invention, FIGS. 3 and 4 show a control block of a generated steam pressure control valve, and FIG. A control block of the steam control valve is shown.
[0020]
As shown in FIG. 2, the exhaust gas from the gas turbine 101 is sent to the exhaust heat recovery boiler 102, and the exhaust heat recovery boiler 102 includes a high pressure drum 103, a first high pressure superheater 104, a second A high-pressure superheater 105 is provided, and an intermediate-pressure drum 106, an intermediate-pressure superheater 107, and a reheater 108 are provided. The steam generated in the high-pressure drum 103 is sent from the high-pressure side steam introduction path 109 to the high-pressure steam turbine 110 via the first high-pressure superheater 104 and the second high-pressure superheater 105. The exhaust steam of the high-pressure steam turbine 110 is sent from the steam introduction path 111 to the intermediate-pressure steam turbine 112 through the reheater 108. Then, the exhaust steam from the intermediate pressure steam turbine 112 is sent to the low pressure steam turbine 113, condensed in the condenser 114, and recovered to the exhaust heat recovery boiler 102 side. On the other hand, the steam of the intermediate pressure drum 106 is sent to the intermediate pressure steam turbine 112 through the intermediate pressure superheater 107 and the reheater 108 sequentially from the intermediate pressure side steam introduction path 115 as a steam introduction path.
[0021]
A steam flow path 116 is provided as a steam cooling path branched from the intermediate pressure side steam introduction path 115, and the steam flow path 116 is bypassed via a combustor 117 that is a high-temperature part of the gas turbine 101, and the intermediate pressure steam turbine 112. It merges with the steam introduction path 111 on the inlet side. A steam amount control valve 201 is provided in the steam channel 116 on the outlet side of the combustor 117, and the steam amount of the steam channel 116 is adjusted by opening and closing the steam amount control valve 201. Note that the steam amount control valve 201 may be provided in the steam flow path 116 on the inlet side of the combustor 117. Further, a high-pressure steam flow path 118 branches from the high-pressure side steam introduction path 109 on the downstream side of the second high-pressure superheater 105, and the high-pressure steam flow path 118 joins the steam flow path 116 on the front side of the gas turbine 101. is doing. The high-pressure steam channel 118 is joined with an auxiliary fluid channel 119 into which feed water from an intermediate pressure feed water pump is introduced.
[0022]
A first flow rate control valve 120 is provided in the intermediate pressure side steam introduction path 115 on the downstream side of the branch portion of the steam flow path 116, and the amount of steam flowing through the intermediate pressure side steam introduction path 115 by opening and closing the first flow rate control valve 120. Is adjusted. In addition, a second flow rate control valve 121 is provided in the high-pressure steam flow path 118 on the upstream side of the joining portion of the auxiliary fluid flow path 119, and the steam flow path from the high-pressure steam flow path 118 by opening and closing the second flow rate control valve 121. The flow rate of the high-pressure steam introduced into 116 is adjusted. That is, the temperature of the steam in the steam channel 116 is adjusted. Further, the auxiliary fluid flow path 119 is provided with a third flow rate control valve 122 as an auxiliary fluid pressure control valve, and an appropriate amount of medium pressure water supply is introduced into the high pressure steam flow path 118 by opening and closing the third flow rate control valve 122. Thus, the temperature of the steam in the high-pressure steam channel 118 is reduced, and the temperature of the high-pressure steam introduced into the steam channel 116 is controlled to a predetermined temperature.
[0023]
A temperature detection means T1 is provided in the steam flow path 116 between the joining portion of the high-pressure steam flow path 118 and the gas turbine 101, and the temperature of the steam introduced into the gas turbine 101 is detected by the temperature detection means T1. A differential pressure detecting means P1 for detecting a steam pressure difference between the inlet side and the outlet side of the combustor 117 in the steam flow path 116 is provided, and the differential pressure of the steam flowing through the combustor 117 by the differential pressure detecting means P1, that is, the flow rate. Is detected. The high-pressure steam flow path 118 on the downstream side of the joining portion of the auxiliary fluid flow path 119 is provided with second temperature detection means T3 as auxiliary steam temperature detection means, and the high-pressure steam flow path is provided by the second temperature detection means T3. 118 steam temperatures are detected. In the figure, P2 is an inlet pressure detecting means for detecting the steam pressure on the inlet side of the combustor 117 of the steam channel 116, and P3 is a steam pressure on the outlet side of the combustor 117 of the steam channel 116. An outlet pressure detecting means T2 is an outlet temperature detecting means as a post-cooling steam temperature detecting means for detecting the steam temperature on the outlet side of the combustor 117 of the steam channel 116. Further, on the inlet side of the combustor 117, a casing pressure detecting means P4 for detecting the casing pressure of the combustor 117 is provided.
[0024]
Detection information of temperature detection means T1, differential pressure detection means P1 and second temperature detection means T3, inlet pressure detection means P2, outlet pressure detection means P3, outlet temperature detection means T2 and vehicle compartment pressure detection means P4 is sent to the control means 125. Entered. Further, the output MW of the gas turbine 1 is input to the control means 125. An opening / closing command is output from the control means 125 to the first flow control valve 120, the second flow control valve 121, the third flow control valve 122, and the steam amount control valve 201.
[0025]
By opening and closing the first flow rate control valve 120 according to the detection information of the differential pressure detection means P1, the flow of steam to the intermediate pressure steam turbine 112 side is regulated and flows through the combustor 117. The flow rate of steam is controlled appropriately. Further, the second flow control valve 121 is opened and closed according to the detection information of the differential pressure detection means P1 and the temperature detection means T1, and the third flow control valve 122 is opened and closed according to the detection information of the second temperature detection means T3. As a result, the amount of steam flowing through the combustor 117 is properly controlled while maintaining an appropriate flow rate. Further, the flow rate of the steam flowing through the combustor 117 is appropriately controlled by opening and closing the steam amount control valve 201 in accordance with the detection information of the passenger compartment pressure detection means P4.
[0026]
At this time, when the steam temperature rises due to some abnormality despite the proper amount of steam flowing through the combustor 117 (when the combustor 117 is not cooled as planned), the detection information of the outlet temperature detection means T2 Accordingly, the first flow rate control valve 120, the second flow rate control valve 121, the third flow rate control valve 122, and the steam amount control valve 201 are opened and closed, and the amount of steam in the steam flow path 116 is increased to flow through the combustor 117. An excessive rise in steam temperature is prevented.
[0027]
That is, in the control means 125, the required cooling steam amount of the combustor 117 is calculated, the differential pressure corresponding to the required cooling steam amount is calculated, and the detected value of the differential pressure detection means P1 becomes the calculated differential pressure. In addition, an opening / closing command is output to the first flow control valve 120. As a result, the required cooling steam amount is supplied to the combustor 117. Further, the control means 125 outputs an opening / closing command to the second flow rate control valve 121 so that the necessary steam temperature of the gas turbine 101 is calculated and the detected value of the temperature detection means T1 becomes the calculated temperature. At this time, the control means 125 issues an open / close command to the third flow control valve 122 based on the steam temperature introduced into the steam flow path 116 (detection information of the second temperature detection means T3 and detection information of the temperature detection means T1). Then, the amount of medium-pressure feed water is appropriately controlled, and the steam temperature in the high-pressure steam channel 118 is reduced to a predetermined temperature. Further, the control means 125 outputs an opening / closing command to the steam amount control valve 201 in accordance with the cabin pressure of the combustor 117.
[0028]
When the flow rate of steam flowing through the combustor 117 is increased or decreased by temperature control, the first flow control valve 120 is controlled to open and close based on the detection information of the differential pressure detection means P1, and a prescribed steam flow rate is secured. When the generation delay of the medium pressure steam occurs and the absolute flow rate of the steam flowing through the steam flow path 116 is insufficient, the detected pressure of the differential pressure detecting means P1 is the calculated differential pressure in preference to the temperature control. Thus, the second flow control valve 121 is controlled to be opened and closed, and the steam flow rate is secured by introducing high-pressure steam (backup control). That is, an opening / closing command is also output to the second flow rate control valve 121 even in the differential pressure control, and an opening command based on the temperature control and a high value of the opening command based on the differential pressure control are selected. It is controlled as the opening.
[0029]
In the steam control device described above, the generated steam on the intermediate pressure drum 106 side having a low temperature and the generated steam generated on the high pressure drum 103 having a high temperature are mixed, and the mixed steam flow rate and steam temperature are appropriately controlled to combustor 117. Has been introduced. Further, in order to perform the mixing optimally, the steam flow rate is controlled by opening and closing the first flow rate control valve 120 provided in the intermediate pressure side steam introduction path 115, and the second flow rate control valve 121 provided in the high pressure steam flow path 118. The steam temperature is controlled by adjusting the high-pressure steam flow rate by opening and closing. Further, when the intermediate pressure steam is insufficient, the second flow rate control valve 121 is opened and closed by backup control so that high pressure steam is introduced to secure the flow rate. Further, the flow rate of the steam flowing through the steam flow path 116 is controlled by opening and closing the steam control valve 201 in accordance with the cabin pressure of the combustor 117. For this reason, it becomes possible to appropriately control the flow rate of the steam guided to the combustor 117.
[0030]
Based on FIG. 3 thru | or FIG. 5, the control condition of the 1st flow control valve 120, the 2nd flow control valve 121, and the steam quantity control valve 201 is demonstrated in detail. 3 shows a control block configuration of the first flow rate control valve 120, FIG. 4 shows a control block configuration of the second flow rate control valve 121, and FIG. 5 shows a control block configuration of the steam amount control valve 201.
[0031]
As shown in FIG. 3, the detection information of the temperature detection means T1, the inlet pressure detection means P2, the outlet pressure detection means P3, and the outlet temperature detection means T2 is input to the calculation means 141 of the control means 125. Further, the output MW of the gas turbine 101 is input to the conversion calculation unit 142, and the output MW is converted into the required backup steam flow rate by the conversion calculation unit 142 and input to the addition unit 151. On the other hand, the bias according to the temperature is calculated by the function means 150 based on the detection information of the outlet temperature detection means T2, and the bias value added according to the temperature is added to the output MW of the gas turbine 101 by the addition means 151. Is added. Information obtained by adding the output MW of the gas turbine 101 and the bias value is input to the conversion calculating means 142, and the output MW added with the bias value by the conversion calculating means 142 is converted as the required cooling steam flow rate and calculated. Input to means 141.
[0032]
The bias value is set so that the cooling steam flow rate specifically required increases as the steam temperature detected by the outlet temperature detection means T2 increases. That is, as the steam temperature detected by the outlet temperature detecting means T2 becomes higher, the first flow rate control valve 120 is operated to the closed side, and the amount of steam sent to the steam flow path 116 is controlled to increase. The calculation means 141 converts the input information into a differential pressure equivalent value and outputs it to the addition means 143. The detection information of the differential pressure detection means P1 is input to the addition means 143. The adding means 143 obtains the difference between the information on the differential pressure equivalent value from the computing means 141 and the detected information of the differential pressure detecting means P1, and the PI computing means 144 uses the obtained difference as the opening command of the 0 side information. The zero side information is sent to the selection means 152. A full-close command (minimum opening, for example, an opening of 3% to 5%) is sent from the command unit 153 to the selection unit 152 as one-side information.
[0033]
The selection means 152 is normally turned off and turned on when a command from the comparison means 154 is received. That is, when the selection unit 152 is turned on, the output command is switched from the 0-side information to the 1-side information. When the selection unit 152 is off, the opening command of the 0-side information (the output MW and the output MW of the gas turbine 101) The opening command according to the state of the steam flow path 116 is output to the first flow control valve 120, and when it is on, the opening command (full closing command) of the 1-side information is output to the first flow control valve 120. The Detection information of the outlet temperature detection means T2 is input to the comparison means 154, and the result of the comparison means 154 is sent to the selection means 152. When the comparison means 154 determines that the detection information of the outlet temperature detection means T2 exceeds a predetermined value (upper limit value), the comparison means 154 outputs an ON signal to the selection means 152, and the selection means 152 displays the one-side information. Switch to opening command.
[0034]
Therefore, the first flow rate control valve 120 is controlled to open and close based on the output MW of the gas turbine 101 and the detection information of the status of the steam channel 116 so that the steam amount of the steam channel 116 becomes a predetermined flow rate, Depending on the steam temperature detected by the outlet temperature detecting means T2, when the temperature on the outlet side of the combustor 117 becomes higher, the steam amount in the steam flow path 116 is controlled to be closed so as to increase. The Further, when the detection information of the outlet temperature detection means T2 exceeds a predetermined value (upper limit value), the first flow control valve 120 is fully closed by a full-close command (minimum opening command), and the intermediate pressure drum All the steam from 106 is sent to the steam flow path 116.
[0035]
As shown in FIG. 4, detection information of the temperature detection means T1, the inlet pressure detection means P2, the outlet pressure detection means P3, and the outlet temperature detection means T2 is input to the calculation means 141 of the control device 125. Further, the output MW of the gas turbine 101 is input to the second conversion calculating means 145, and the output MW is converted as the required backup steam flow rate and input to the adding means 162 in the second conversion calculating means 145. On the other hand, the bias according to the temperature is calculated by the function means 161 based on the detection information of the outlet temperature detection means T2, and the bias value added according to the temperature is added to the output MW of the gas turbine 101 by the addition means 162. Is added. Information obtained by adding the output MW of the gas turbine 101 and the bias value is input to the calculation means 141, and the output MW to which the bias value is added by the second conversion calculation means 145 is converted as a required cooling steam flow rate. It is input to the calculation means 141.
[0036]
Then, the calculation means 141 converts the input information into a differential pressure equivalent value and outputs it to the addition means 143. The detection information of the differential pressure detection means P1 is input to the addition means 143. The adding means 143 obtains the difference between the differential pressure equivalent value information from the computing means 141 and the detection information from the differential pressure detecting means P1, and the PI computing means 144 computes the obtained difference as an opening degree command.
[0037]
The bias value is set so that the cooling steam flow rate specifically required increases as the steam temperature detected by the outlet temperature detection means T2 increases. That is, as the steam temperature detected by the outlet temperature detecting means T2 increases, the second flow rate control valve 121 is actuated to the open side, and the amount of steam sent from the high-pressure steam channel 118 to the steam channel 116 increases. To be controlled.
[0038]
Therefore, the second flow rate control valve 121 is controlled to be opened and closed based on the output MW of the gas turbine 101 and the detection information of the status of the steam channel 116 so that the steam amount in the steam channel 116 becomes a predetermined flow rate, Depending on the steam temperature detected by the outlet temperature detection means T2, when the temperature on the outlet side of the combustor 117 becomes higher, the steam amount of the steam flow path 116 is controlled to be increased so that the steam amount increases. The
[0039]
As shown in FIG. 5, the command information from the command means 211 and the detection information from the vehicle compartment pressure detection means P4 are input to the adding means 210 of the control device 125. The information from the adding means 210 is added by the adding means 212 with the detection information of the outlet pressure detecting means P3. Based on these pieces of information, the PI calculation means 213 calculates an opening degree command for the steam control valve 201. The PI calculation means 213 sends the obtained opening degree command as 0 side information to the selection means 214. A full open command is sent from the command unit 215 to the selection unit 152 as one-side information.
[0040]
The selection means 215 is normally turned off and turned on when a command from the comparison means 216 is received. In other words, when the selection unit 215 is turned on, the output command is switched from the 0-side information to the 1-side information. When the selection unit 215 is off, the opening command of the 0-side information (chamber pressure and combustor 117) is switched. The opening degree command according to the outlet side pressure) is output to the steam amount control valve 201, and when it is on, the opening degree command (full open command) of the one side information is output to the steam amount control valve 201. The detection information of the outlet temperature detection means T2 is input to the comparison means 216, and the result of the comparison means 216 is sent to the selection means 214. When the comparison unit 216 determines that the detection information of the outlet temperature detection unit T2 exceeds a predetermined value (upper limit value), the comparison unit 216 outputs an ON signal to the selection unit 215, and the selection unit 214 displays the one-side information. Switch to opening command.
[0041]
Therefore, when the temperature on the outlet side of the combustor 117 rises and the steam temperature detected by the outlet temperature detecting means T2 exceeds a predetermined value (upper limit value), the steam amount control valve 201 is fully opened and cooled. The amount of steam is increased. As a result, even when the cooling steam amount is controlled to a predetermined amount, the cooling steam amount is increased even when the cooling steam temperature rises and exceeds a predetermined value (upper limit value).
[0042]
For this reason, when the temperature on the outlet side of the combustor 117 increases, the amount of cooling steam increases as the steam temperature detected by the outlet temperature detecting means T2 increases, and the outlet temperature detecting means T2 When the detected information exceeds a predetermined value (upper limit value), all the steam from the intermediate pressure drum 106 is sent to the steam passage 116 and the steam control valve 201 is fully opened to increase the amount of cooling steam. The As a result, the combustor 117 is protected even when the cooling steam temperature rises despite the cooling steam amount being controlled to a predetermined amount.
[0043]
Therefore, when the temperature of the cooling steam supplied to the combustor 117 rises due to some abnormality and there is a possibility of damage or the like, the flow rate of the cooling steam sent to the combustor 117 is increased to protect the combustor 117. It becomes possible. Therefore, even if the temperature on the outlet side of the combustor 117 rises, the steam cooling device can protect the combustor 117 without using the interlock function.
[0044]
The opening / closing control of the first flow rate control valve 120 and the second flow rate control valve 121 when the temperature on the outlet side of the combustor 117 becomes high is performed by, for example, closing the first flow rate control valve 120 from the intermediate pressure drum 106. Even when the steam is sent to the steam flow path 116 and the first flow rate control valve 120 is fully closed, when the temperature on the outlet side of the combustor 117 is high, the second flow rate control valve 121 is opened to open the high pressure steam flow path 118. The amount of steam from the side is increased. When the temperature on the outlet side of the combustor 117 exceeds a predetermined value (upper limit value), the steam control valve 201 is fully opened to increase the amount of cooling steam. The opening / closing control status of the first flow control valve 120 and the second flow control valve 121 is appropriately set according to the capacity of the equipment, etc., and other control valves can be used to ensure both a predetermined flow rate and a predetermined temperature. It is implemented in combination with the opening and closing of. Further, the opening / closing control of the steam amount control valve 201 is appropriately opened / closed according to the temperature increased before the temperature on the outlet side of the combustor 117 exceeds a predetermined value (upper limit value), and exceeds the predetermined value (upper limit value). Sometimes it may be fully open.
[0045]
【The invention's effect】
The steam cooling device for a gas turbine according to the present invention includes an exhaust heat recovery boiler that generates steam by exhaust gas from the gas turbine, a steam turbine that operates by steam generated in the exhaust heat recovery boiler, and steam from the exhaust heat recovery boiler. A steam introduction path to be introduced into the steam turbine, a steam cooling path that is provided in the steam introduction path and bypasses the steam from the exhaust heat recovery boiler for cooling the high-temperature components of the gas turbine, and a steam cooling path provided in the steam cooling path A steam amount control valve for controlling the amount of steam introduced into the steam, a post-cooling steam temperature detecting means for detecting the steam temperature after cooling the high-temperature component provided in the steam cooling path on the downstream side of the high-temperature component, and after cooling In order to adjust the flow rate of the steam flowing into the steam cooling path based on the detection information of the steam temperature detecting means, the steam amount control valve is controlled to open and close and the flow rate of the steam flowing into the steam cooling path is determined. Control means to control the state, so when the steam temperature after cooling rises, the amount of cooling steam is increased by controlling the steam amount control valve so as to increase the flow rate of steam led to the high-temperature parts. High temperature parts can be protected. As a result, even when the temperature on the outlet side of the high temperature component rises, the high temperature component is protected without using the interlock function, and the high temperature component can be prevented from being damaged.
[0046]
The steam cooling device for a gas turbine according to the present invention includes an exhaust heat recovery boiler that generates steam by exhaust gas from the gas turbine, a steam turbine that operates by steam generated in the exhaust heat recovery boiler, and an exhaust heat recovery boiler. Generated in a steam introduction path for introducing steam into the steam turbine, a steam cooling path provided in the steam introduction path for bypassing steam from the exhaust heat recovery boiler to cool the high-temperature components of the gas turbine, and an exhaust heat recovery boiler Generated steam pressure detecting means for detecting the steam pressure and generated steam pressure for controlling the steam flow rate in the steam introduction path based on the detection information of the generated steam pressure detecting means for adjusting the steam pressure generated in the exhaust heat recovery boiler. A control valve, a steam control valve provided in the steam cooling path for controlling the amount of steam introduced into the steam cooling path, and a high temperature provided in the steam cooling path on the downstream side of the high-temperature component. The detection value of the generated steam pressure detecting means for adjusting the steam flow rate flowing into the steam cooling path based on the state of the gas turbine and the steam temperature detecting means for detecting the steam temperature after cooling the product is a set value. The generated steam pressure control valve and the steam amount control valve are used to control the opening and closing of the generated steam pressure control valve to adjust the flow rate of steam flowing into the steam cooling path based on the detection information of the steam temperature detection means after cooling. Control means for controlling opening and closing of the steam, so that when the steam temperature rises after cooling, the generated steam pressure control valve and the steam volume control valve are controlled so as to increase the steam flow rate led to the high-temperature parts. By increasing the amount of cooling steam, it becomes possible to protect high-temperature parts. As a result, even when the temperature on the outlet side of the high temperature component rises, the high temperature component is protected without using the interlock function, and the high temperature component can be prevented from being damaged.
[0047]
Also, a steam cooling path is provided by branching from the steam introduction path from the intermediate pressure drum to the intermediate pressure steam turbine, and an intermediate pressure drum pressure control valve is provided in the steam introduction path on the downstream side of the branch portion of the steam cooling path. The generated steam pressure control valve is provided with a medium pressure drum pressure control valve for controlling the flow rate of the steam introduction path based on the detection information of the post-cooling steam temperature detection means to ensure the flow rate of the steam cooling path. Since the function of performing opening / closing control is provided, the steam from the intermediate pressure drum can be sent to the steam cooling path.
[0048]
In addition, an auxiliary steam introduction path through which steam from the high-pressure drum is introduced is connected to the steam cooling path, and an auxiliary steam pressure control valve is provided in the auxiliary steam introduction path as a generated steam pressure control valve. A function of controlling the opening and closing of the auxiliary steam pressure control valve so as to secure the flow rate of the steam cooling path by controlling the flow rate of the auxiliary steam introduction path based on the detection information of the steam temperature detecting means is provided. Steam from can be sent to the steam cooling path.
[0049]
In addition, a steam cooling path is provided by branching from the steam introduction path from the intermediate pressure drum to the intermediate pressure steam turbine, and an auxiliary steam introduction path for introducing steam from the high pressure drum is connected to the steam cooling path. An intermediate pressure drum pressure control valve is provided in the steam introduction path on the downstream side of the branch portion to form a generated steam pressure control valve, and an auxiliary steam pressure control valve is provided in the auxiliary steam introduction path to form a generated steam pressure control valve, The control means controls the opening and closing of the intermediate pressure drum pressure control valve so as to secure the flow rate of the steam cooling path by regulating the flow rate of the steam introduction path based on the detection information of the post-cooling steam temperature detection means, and after cooling Since the auxiliary steam pressure control valve is controlled to open and close so as to secure the flow rate of the steam cooling path by controlling the flow rate of the auxiliary steam introduction path based on the detection information of the steam temperature detecting means. Steam from the drum And steam and auxiliary steam from the high pressure drum can be sent to the steam cooling passage.
[0050]
Further, the control means has a function of controlling the steam flow rate control valve to be fully open when the steam temperature detecting means after cooling detects that the steam temperature exceeds the upper limit value. When the value is exceeded, the maximum amount can be passed through the steam cooling path.
[Brief description of the drawings]
FIG. 1 is a schematic system diagram showing a cooling system of a combined power plant provided with a steam cooling device for a gas turbine according to a first embodiment of the present invention.
FIG. 2 is a schematic configuration diagram of a combined power plant including a steam cooling device for a gas turbine according to a second embodiment of the present invention.
FIG. 3 is a control block diagram of a generated steam pressure control valve.
FIG. 4 is a control block diagram of a generated steam pressure control valve.
FIG. 5 is a control block diagram of a steam amount control valve.
[Explanation of symbols]
1,101 Gas turbine
2,102 Waste heat recovery boiler
3,103 high pressure drum
4 High pressure superheater
5,106 Medium pressure drum
6,107 Medium pressure superheater
7,108 Reheater
8,109 High-pressure steam inlet
9,110 High-pressure steam turbine
10,115 Medium pressure steam inlet
11,112 Medium pressure steam turbine
12 Medium pressure drum pressure control valve
13,117 combustor
14. Steam cooling path
15 Steam flow control valve
20,114 condenser
116 Steam flow path
118 High-pressure steam flow path
119 Auxiliary fluid flow path
120 First flow control valve
121 Second flow control valve
122 Third flow control valve
125 Control means
141 Calculation means
142 Conversion operator
143, 151, 162, 210, 212 addition means
144,213 PI calculation means
145 Second conversion calculation means
150,161 function means
152, 214 selection means
153, 215 command means
154,216 comparison means

Claims

An exhaust heat recovery boiler that generates steam by exhaust gas from the gas turbine, a steam turbine that operates by steam generated in the exhaust heat recovery boiler, a steam introduction path that introduces steam from the exhaust heat recovery boiler into the steam turbine, and steam A steam cooling path provided in the introduction path for bypassing steam from the exhaust heat recovery boiler to cool the high-temperature components of the gas turbine, generated steam pressure detection means for detecting the steam pressure generated in the exhaust heat recovery boiler, A generated steam pressure control valve that controls the flow rate of the steam in the steam introduction path based on detection information of the generated steam pressure detection means to adjust the steam pressure generated in the heat recovery boiler, and a steam cooling path provided in the steam cooling path A steam control valve that controls the amount of steam introduced into the steam and a post-cooling steam that is provided in a steam cooling path on the downstream side of the high-temperature part and detects the steam temperature after cooling the high-temperature part. Controls the opening and closing of the generated steam pressure control valve so that the detected value of the generated steam pressure detection means for adjusting the flow rate of steam flowing into the steam cooling passage becomes a set value based on the temperature detection means, of the gas turbine condition gas and a row intends control means closing control of generating steam pressure control valve and the steam amount control valve for adjusting the flow rate of steam flowing into the steam cooling passage based on detection information after cooling steam temperature detection means together with In turbine steam cooling system,
An auxiliary steam introduction path through which steam from the high-pressure drum of the exhaust heat recovery boiler is introduced is connected to a steam cooling path, and an auxiliary steam pressure control valve is provided in the auxiliary steam introduction path to form a generated steam pressure control valve. Has a function of controlling the flow of the auxiliary steam introduction passage based on the detection information of the post-cooling steam temperature detecting means and controlling the opening and closing of the auxiliary steam pressure control valve so as to secure the flow rate of the steam cooling passage. A steam cooling device for a gas turbine.

An exhaust heat recovery boiler that generates steam by exhaust gas from the gas turbine, a steam turbine that operates by steam generated in the exhaust heat recovery boiler, a steam introduction path that introduces steam from the exhaust heat recovery boiler into the steam turbine, and steam A steam cooling path provided in the introduction path for bypassing steam from the exhaust heat recovery boiler to cool the high-temperature components of the gas turbine, generated steam pressure detection means for detecting the steam pressure generated in the exhaust heat recovery boiler, A generated steam pressure control valve that controls the flow rate of the steam in the steam introduction path based on detection information of the generated steam pressure detection means to adjust the steam pressure generated in the heat recovery boiler, and a steam cooling path provided in the steam cooling path A steam control valve that controls the amount of steam introduced into the steam and a post-cooling steam that is provided in a steam cooling path on the downstream side of the high-temperature part and detects the steam temperature after cooling the high-temperature part. The opening / closing control of the generated steam pressure control valve is performed so that the detected value of the generated steam pressure detecting means becomes a set value in order to adjust the flow rate of the steam flowing into the steam cooling path based on the temperature detecting means and the state of the gas turbine. And a control means for controlling the opening and closing of the generated steam pressure control valve and the steam amount control valve in order to adjust the flow rate of the steam flowing into the steam cooling path based on the detection information of the post-cooling steam temperature detecting means . In the steam cooling device,
A steam cooling path is provided by branching from the steam introduction path from the intermediate pressure drum to the intermediate pressure steam turbine in the exhaust heat recovery boiler, and an auxiliary steam introduction path for introducing steam from the high pressure drum is connected to the steam cooling path. An intermediate-pressure drum pressure control valve is provided in the steam introduction path on the downstream side of the branch of the steam cooling path to form a generated steam pressure control valve, and an auxiliary steam pressure control valve is provided in the auxiliary steam introduction path to generate steam pressure. The control means controls the opening / closing of the intermediate pressure drum pressure control valve so as to secure the flow rate of the steam cooling path by regulating the flow rate of the steam introduction path based on the detection information of the post-cooling steam temperature detection means. And a function of controlling the opening and closing of the auxiliary steam pressure control valve so as to secure the flow rate of the steam cooling path by controlling the flow rate of the auxiliary steam introduction path based on the detection information of the post-cooling steam temperature detecting means. That features Steam cooling apparatus for a gas turbine.