JP3782565B2

JP3782565B2 - Combined cycle power plant

Info

Publication number: JP3782565B2
Application number: JP31411197A
Authority: JP
Inventors: 洋一杉森; 幸生渋谷
Original assignee: Toshiba Corp
Current assignee: Toshiba Corp
Priority date: 1997-11-14
Filing date: 1997-11-14
Publication date: 2006-06-07
Anticipated expiration: 2017-11-14
Also published as: JPH11148315A

Description

【０００１】
【発明の属する技術分野】
本発明はガスタービン高温部の冷却に、冷却媒体として蒸気を使用するコンバインドサイクル発電プラントに関する。
【０００２】
【従来の技術】
最近の火力発電プラントでは、プラント熱効率の向上を図るため、ガスタービンプラント、蒸気タービンプラントおよび排熱回収ボイラを組み合せたコンバインドサイクル発電プラントが数多く実機として運転されている。このコンバインドサイクル発電プラントのプラント熱効率は、ガスタービンプラント、蒸気タービンプラントおよび排熱回収ボイラの各プラントの入熱の総和に対する各プラントの出熱の総和の比率から算出される。プラント熱効率の向上の観点から蒸気タービンプラント、排熱回収ボイラおよびガスタービンプラントを見直した場合、蒸気タービンおよび排熱回収ボイラは既に限界に達しており、ガスタービンプラントの熱効率の改善がコンバインドサイクル発電プラントのプラント熱効率の向上につながると期待されている。
【０００３】
ガスタービンプラントは、ガスタービンの入口燃焼ガス温度が高いほど熱効率を向上させることができ、最近の耐熱材料の開発と相俟って冷却技術の進歩により、ガスタービンの入口燃焼ガス温度をひところの１０００℃級から１３００℃級を経て１５００℃級以上に移行しつつある。
【０００４】
ガスタービンの入口燃焼ガス温度を１５００℃以上にする場合、耐熱材料が開発されていると言えども、ガスタービン高温部、例えば燃焼ガスに直接曝されるガスタービン静翼、ガスタービン動翼、燃焼器のライナやトラジションピース等の許容メタル温度は既に限界に達しており、起動・停止回数の多い運転や、長時間に亘る連続運転のときに材料の破損・溶融など事故につながるおそれがある。
【０００５】
このため、ガスタービンの入口燃焼ガス温度を上昇させても、ガスタービン高温部の各部品の許容メタル温度以内に維持できる技術として耐熱材料の開発と並行して、空気を用いてガスタービン高温部を冷却する冷却技術の開発が進められ、既に実用機として実現している。
【０００６】
しかし、空気を用いてガスタービン高温部を冷却する場合、その冷却空気供給源は、ガスタービンに直結した空気圧縮機から求めているために、空気圧縮機からガスタービンに供給される数十％の高圧空気がガスタービン高温部の冷却用に廻され、タービン翼を冷却後に高温ガス中に吹き出されるため、作動ガスの温度低下、ミキシングロスが生じ、プラント熱効率の改善上好ましくない。
【０００７】
最近、ガスタービンプラントのガスタービン高温部、例えばガスタービン静翼、ガスタービン動翼などに冷却媒体として蒸気の活用が見直されており、既にアメリカ機械学会誌（ＡＳＭＥ論文、９２−ＧＴ−２４０）や特開平５−１６３９６１号公報などに公表されている。
【０００８】
蒸気は、空気に較べ、比熱が約２倍で、伝熱性能も優れているため、閉ループの冷却が可能となり、作動ガスの温度低下およびミキシングロスがなくなるため、プラント効率の改善に寄与でき、実用機への適用が期待されている。
【０００９】
【発明が解決しようとする課題】
コンバインドサイクル発電プラントにおいて、ガスタービン高温部に冷却媒体として蒸気を供給する場合、その蒸気は、ガスタービン高温部を冷却後、蒸気タービンに回収されるが、その回収温度はガスタービンの冷却性能から制約されてしまい、再熱蒸気温度（中圧タービン入口温度）が制約を受ける。
【００１０】
本発明は、上述した事情を考慮してなされたもので、ガスタービン側の制約によらず、ガスタービン冷却後の蒸気を再熱し、所望する再熱蒸気温度を効率よく有効的に得ることができるコンバインドサイクル発電プラントを提供することを目的とする。
【００１１】
本発明の他の目的は、ガスタービンの冷却性能を向上させるとともに、ガスタービン冷却後の蒸気を再熱して所望の再熱蒸気温度を得、タービン出力制御を容易にしたコンバインドサイクル発電プラントを提供にある。
【００１２】
【課題を解決するための手段】
本発明に係るコンバインドサイクル発電プラントは、上述した課題を解決するために、請求項１に記載したように、ガスタービンを備えたガスタービンプラントと、上記ガスタービンからの排ガスを利用して蒸気を発生させる排熱回収ボイラと、この排熱回収ボイラで発生した蒸気を蒸気タービンの駆動源とする蒸気タービンプラントと、上記ガスタービン高温部の入口側に接続され、蒸気タービンからの排気蒸気を冷却蒸気として供給する冷却蒸気供給系統を備えたコンバインドサイクル発電プラントにおいて、前記ガスタービン高温部の出口側に接続され、ガスタービン冷却後の蒸気を回収する冷却蒸気回収系統を備え、この冷却蒸気回収系統はガスタービン冷却後の蒸気を排熱回収ボイラに導くボイラ回収系統と、ガスタービン冷却後の蒸気を排熱回収ボイラにて再熱する再熱器と、再熱された蒸気を上記蒸気タービンに回収するタービン回収系とを備え、前記冷却蒸気回収系統は再熱器下流側に減温器を設け、この減温器で再熱蒸気温度を制御したものである。
【００１４】
さらに、本発明に係るコンバインドサイクル発電プラントは、上述した課題を解決するために、請求項２に記載したように、ガスタービンを備えたガスタービンプラントと、上記ガスタービンからの排ガスを利用して蒸気を発生させる排熱回収ボイラと、この排熱回収ボイラで発生した蒸気を蒸気タービンの駆動源とする蒸気タービンプラントと、上記ガスタービン高温部の入口側に接続され、蒸気タービンからの排気蒸気を冷却蒸気として供給する冷却蒸気供給系統を備えたコンバインドサイクル発電プラントにおいて、前記ガスタービン高温部の出口側に接続された冷却蒸気回収系統を備え、この冷却蒸気回収系統は、途中にガスタービン高温部冷却後の蒸気を前記蒸気タービンプラントの再熱蒸気系統の低温側に回収させるものである。
【００１５】
さらにまた、本発明に係るコンバインドサイクル発電プラントは、上述した課題を解決するために、請求項３に記載したように、ガスタービンを備えたガスタービンプラントと上記ガスタービンからの排ガスを利用して蒸気を発生させる排熱回収ボイラと、この排熱回収ボイラで発生した蒸気を蒸気タービンの駆動源とする蒸気タービンプラントと、上記ガスタービン高温部の入口側に接続され、上記蒸気タービンからの排気蒸気を冷却蒸気として供給する冷却蒸気供給系統を備えたコンバインドサイクル発電プラントにおいて、上記ガスタービン高温部の出口側に接続された冷却蒸気回収系統を備え、この冷却蒸気回収系統は、途中にガスタービン高温部冷却後の蒸気を、前記蒸気タービンプラントの再熱蒸気系統に設置された減温器の上流側に回収させるものである。
【００１６】
またさらに、本発明に係るコンバインドサイクル発電プラントは、上述した課題を解決するために、請求項４に記載したように、ガスタービンを備えたガスタービンプラントと、上記ガスタービンからの排ガスを利用して蒸気を発生させる排熱回収ボイラと、この排熱回収ボイラで発生した蒸気を蒸気タービンの駆動源とする蒸気タービンプラントと、上記ガスタービン高温部の入口側に接続され、蒸気タービンからの排気蒸気を冷却蒸気として供給する冷却蒸気供給系統を備えたコンバインドサイクル発電プラントにおいて、上記ガスタービン高温部の出口側に接続された冷却蒸気回収系統を備え、この冷却蒸気回収系統は、途中にガスタービン高温部冷却後の蒸気を、上記蒸気タービンプラントの再熱蒸気系統に設置された減温器の下流側に回収させるものである。
【００１７】
さらに、本発明に係るコンバインドサイクル発電プラントは、上述した課題を解決するために、請求項５に記載したように、ガスタービンを備えたガスタービンプラントと、上記ガスタービンからの排ガスを利用して蒸気を発生させる排熱回収ボイラと、この排熱回収ボイラで発生した蒸気を蒸気タービンの駆動源とする蒸気タービンプラントと、上記ガスタービン高温部の入口側に接続され、蒸気タービンの排気蒸気を冷却蒸気として供給する冷却蒸気供給系統を備えたコンバインドサイクル発電プラントにおいて、上記ガスタービン高温部の出口側に接続された冷却蒸気回収系統を備え、この冷却蒸気回収系統は、途中にガスタービン冷却後の蒸気を温度制御する減温器を備えて、前記蒸気タービンプラントの再熱蒸気系統の低温側に接続し、再熱蒸気系統の低温側にガスタービン冷却後の蒸気を回収させたものである。
【００１８】
また、本発明に係るコンバインドサイクル発電プラントは、上述した課題を解決するために、請求項６に記載したように、ガスタービンを備えたガスタービンプラントと、上記ガスタービンからの排ガスを利用し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を蒸気タービンの駆動源とする蒸気タービンプラントと、上記ガスタービン高温部の入口側に接続され、上記蒸気タービンからの排気蒸気を冷却蒸気として供給する冷却蒸気供給系統を備えたコンバインドサイクル発電プラントにおいて、上記ガスタービン高温部の出口に接続された冷却蒸気回収系統を備え、この冷却蒸気回収系統は、途中にガスタービン冷却後の蒸気を温度制御する減温器を備えて前記蒸気タービンプラントの再熱蒸気系統の減温器上流側に接続し、上記減温器の上流側にガスタービン冷却後の蒸気を回収させたものである。
【００１９】
さらに、本発明に係るコンバインドサイクル発電プラントは、上述した課題を解決するために、請求項７に記載したように、ガスタービンを備えたガスタービンプラントと、蒸気ガスタービンからの排ガスを利用して蒸気を発生させる排熱回収ボイラと、この排熱回収ボイラで発生した蒸気を蒸気タービンの駆動源とする蒸気タービンプラントと、上記ガスタービン高温部の入口側に接続され、蒸気タービンからの排気蒸気を冷却蒸気として供給する冷却蒸気供給系統を備えたコンバインドサイクルプラントにおいて、上記ガスタービン高温部の出口側に接続された冷却蒸気回収系統を備え、この冷却蒸気回収系統は、途中にガスタービン冷却後の蒸気を温度制御する減温器を備えて再熱蒸気系統の減温器下流側に接続し、上記減温器の下流側にガスタービン冷却後の蒸気を回収させたものである。
【００２０】
さらにまた、本発明に係るコンバインドサイクル発電プラントは、上述した課題を解決するために、請求項８に記載したように、ガスタービンを備えたガスタービンプラントと、上記ガスタービンからの排ガスを利用して蒸気を発生させる排熱回収ボイラと、この排熱回収ボイラで発生した蒸気を蒸気タービンの駆動源とする蒸気タービンプラントと、上記ガスタービン高温部の入口側に接続され、蒸気タービンからの排気蒸気を冷却蒸気として供給する冷却蒸気供給系統を備えたコンバインドサイクル発電プラントにおいて、上記ガスタービン高温部の出口側に接続された冷却蒸気回収系統を備え、この冷却蒸気回収系統はガスタービン冷却後の蒸気を排熱回収ボイラ内で再熱する冷却蒸気再熱器を、途中に備えた再熱蒸気系統の減温器上流側に接続され、この減温器上流側にガスタービン冷却後の蒸気を回収させたものである。
【００２１】
またさらに、本発明に係るコンバインドサイクル発電プラントは、上述した課題を解決するために、請求項９に記載したように、ガスタービンを備えたガスタービンプラントと、上記ガスタービンからの排ガスを利用して蒸気を発生させる排熱回収ボイラと、この排熱回収ボイラで発生した蒸気を蒸気タービンの駆動源とする蒸気タービンプラントと、上記ガスタービン高温部の入口側に接続され、蒸気タービンからの排気蒸気を冷却蒸気として供給する冷却蒸気供給系統を備えたコンバインドサイクル発電プラントにおいて、上記ガスタービン高温部の出口側に接続された冷却蒸気回収系統を備え、この冷却蒸気回収系統はガスタービン冷却後の蒸気を排熱回収ボイラ内で再熱する冷却蒸気再熱器を、途中に備えた前記蒸気タービンプラントの再熱蒸気系統の減温器下流側に接続し、この減温器下流側にガスタービン冷却後の蒸気を回収させたものである。
【００２２】
さらに、上述した課題を解決するために、本発明に係るコンバインドサイクル発電プラントは、請求項１０に記載したように、冷却蒸気回収系統は、冷却蒸気再熱器の下流側に減温器を設け、ガスタービン冷却後の再熱蒸気を減温器で温度制御して蒸気タービンプラントの再熱蒸気系統に回収させたものである。
【００２３】
【発明の実施の形態】
本発明に係るコンバインドサイクル発電プラントの実施形態について添付図面を参照して説明する。
【００２４】
図１は、本発明に係るコンバインドサイクル発電プラントの第１実施形態を概略的に示す系統図である。
【００２５】
本実施形態は、排熱回収ボイラ１を別置きにし、ガスタービンプラント２と蒸気タービンプラント３と発電機４とを同一の回転軸５に直結した一軸型コンバインドサイクル発電プラントである。
【００２６】
ガスタービンプラント２は、空気圧縮機６、燃焼器７およびガスタービン８をそれぞれ備え、空気圧縮機６で吸込んだ大気を高圧化して燃焼器７に案内し、その高圧空気に燃料を加えて燃焼させて燃焼ガスを生成し、その燃焼ガスをガスタービン８に案内して膨張仕事をさせ、膨張仕事後の排ガス（排熱）を蒸気発生源としての排熱回収ボイラ１に供給するようになっている。
【００２７】
排熱回収ボイラ１は、軸方向に向かって延びるケーシング９を備え、このケーシング９内に燃焼排ガスの流れに沿って順に必要に応じて第２高圧過熱器１０、第２再熱器１１、第１再熱器１２、第１高圧過熱器１３、高圧蒸発器１４、中圧過熱器１５、第３高圧節炭器１６、低圧過熱器１７、中圧蒸発器１８、第２中圧節炭器１９、第２高圧節炭器２０、低圧蒸発器２１、第１高圧節炭器２２および第１中圧節炭器２３がそれぞれ設置される。また、高、中、低圧の各蒸発器１４、１８、２１には、高圧ドラム２４、中圧ドラム２５および低圧ドラム２６がそれぞれ接続され、蒸発器１４、１８、２１で蒸発した飽和蒸気を、各ドラム２４，２５，２６内で気液分離させている。
【００２８】
一方、蒸気タービンプラント３は、蒸気タービンが高圧タービン２７、中圧タービン２８および低圧タービン２９にそれぞれ区分けされており、排熱回収ボイラ１の第２高圧過熱器１０から高圧加減弁３０を経て主蒸気（過熱蒸気）系統３１を案内された過熱蒸気を、高圧タービン２７に導き、この高圧タービン２７で膨張仕事をさせている。高圧タービン２７で膨張仕事をした後の排気蒸気は再熱蒸気系統３２に案内され、その低温再熱蒸気管３３を介して第１再熱器１２、減温器３４、第２再熱器１１に順次導かれて再熱蒸気にし、その再熱蒸気を再熱蒸気系統３２の高温再熱蒸気管３５および再熱組合せ弁３６を経て中圧タービン２８に案内し、この中圧タービン２８で膨張仕事をさせる。符号３７は再熱蒸気系統３２の低温再熱蒸気管３３に設けられた再熱蒸気流量調節弁であり、この再熱蒸気流量調節弁３７はガスタービン冷却蒸気流量調節弁を兼ねている。
【００２９】
さらに、中圧タービン２８で仕事をした排気蒸気は続いて低圧タービン２９に案内され、この低圧タービン２９でも膨張仕事させ、各蒸気タービン２７、２８、２９の膨張仕事による回転動力で発電機４を駆動するようになっている。
【００３０】
また、低圧タービン２９には、排熱回収ボイラ１の低圧過熱器１７から低圧蒸気供給系３８の低圧蒸気組合せ弁３９を経て低圧蒸気が案内されており、その低圧蒸気の膨張仕事により発生した回転動力で発電機４を駆動するようになっている。
【００３１】
また、低圧タービン２９では、膨張仕事後の排気蒸気を復水器４０に案内し、ここで凝縮させて復水にし、凝縮後の復水を復水給水系統４１の復水ポンプ４３、給水ポンプ４４で昇圧している。給水ポンプ４４の下流側は２又に分岐され、給水として排熱回収ボイラ１の第１中圧節炭器２３および第１高圧節炭器２２にそれぞれ供給されるようになっている。
【００３２】
このコンバインドサイクル発電プラントにおいては、ガスタービン８の高温部４６、例えばガスタービン静翼、ガスタービン動翼、燃焼器７のライナおよびトランジションピース等を蒸気で冷却する冷却蒸気系統４７が設けられる。この冷却蒸気系統４７は冷却蒸気供給系統４８、冷却蒸気回収系統４９および冷却蒸気バイパス系統５０をそれぞれ備える。冷却蒸気バイパス系統５０には常閉のバイパス蒸気弁５１が設けられる。
【００３３】
一方、冷却蒸気供給系統４８は、高圧タービン２７の低温再熱蒸気管３３から、第１再熱器１２に至る分岐点Ａで分岐されて構成される。上記冷却蒸気供給系統４８は逆止弁５３を経由し、合流点Ｂにて中圧蒸気系統５４と合流し、ガスタービン８の高温部４６の入口に接続される。中圧蒸気系統５４は、中圧過熱器１５に接続されており、中圧ドラム２５で発生した蒸気が全量供給される。
【００３４】
また、ガスタービン２の高温部４６の出口側には冷却蒸気回収系統４９が接続され、この冷却蒸気回収系統４９でガスタービン高温部４６冷却後の蒸気を回収するようになっている。
【００３５】
冷却蒸気回収系統４９は、ガスタービン冷却後の蒸気を排熱回収ボイラ１に導くボイラ回収系統５５と、冷却後の蒸気を排熱回収ボイラ１にて再熱する再熱手段としての冷却蒸気再熱器５６と、この再熱器５６を通る間に再熱された蒸気を蒸気タービンの中圧タービン２８に回収するタービン回収系統５７とを備える。タービン回収系統５７は再熱蒸気系統３２の高温再熱蒸気管３５と合流点Ｃ1 にて合流せしめられる。再熱手段には再熱器５６の下流側に再熱蒸気温度制御のための減温器が必要に応じて設けられる。
【００３６】
このコンバインドサイクル発電プラントにおいて、プラント起動時には排熱回収ボイラ１から発生する蒸気は、圧力・温度が所定の値に達するまでは高圧タービンバイパス系統６０、中圧タービンバイパス系統６１および低圧タービンバイパス系統６２により蒸気タービン２７，２８，２９をバイパスして復水器４０に導かれる。各タービンバイパス系統６０，６１，６２には常閉の高圧、中圧、低圧タービンバイパス弁６３，６４，６５がそれぞれ設けられる。
【００３７】
また、冷却蒸気系統４７のガスタービンの冷却蒸気は、所定の圧力・温度に達するまでは冷却蒸気バイパス系統５０によりガスタービン高温部４６をバイパスするとともに、冷却蒸気供給系統４８および冷却蒸気回収系統４９のウォーミングを行なう。
【００３８】
さらに、冷却蒸気系統４７にガスタービン冷却蒸気の供給を開始する際には、その蒸気供給圧力を設定値に保つために、中圧タービンバイパス弁６１によってガスタービン冷却蒸気の供給圧力制御を行なう。
【００３９】
ガスタービン冷却蒸気の流量は再熱蒸気系統３２のガスタービン冷却蒸気流量調節弁３７によって制御され、また、ガスタービン冷却蒸気の供給温度は、主蒸気の温度を減温器６６によって制御することで行なう。
【００４０】
次に、コンバインドサイクル発電プラントの運転を説明する。
【００４１】
このコンバインドサイクル発電プラントは、ガスタービンプラント２と蒸気タービンプラント３とを協動させて発電機４を駆動させ、発電させる。
【００４２】
ガスタービンプラント２は、空気調和機６で圧縮された高圧空気を燃焼器７に案内し、この燃焼器７のライナ内で燃料の供給を受けて燃焼せしめられる。燃焼器７からの燃焼ガスはトランジションピースを介してガスタービン８に供給され、このガスタービン８でタービン動翼を駆動させ、回転軸５を回転駆動させる。
【００４３】
ガスタービン８を駆動させることにより膨張した燃焼排ガスは、続いて排熱回収ボイラ１に案内され、この排熱回収ボイラ１にて蒸気タービンプラント３の蒸気タービン２７，２８，２９を駆動させる蒸気を発生させる。
【００４４】
排熱回収ボイラ１の第２高圧過熱器１０で過熱された過熱蒸気は、主蒸気系統（過熱蒸気系統）３１を通って高圧タービン２７に導かれ、この高圧タービン２７を駆動させる。高圧タービン２７を駆動させ、仕事をした蒸気は、膨張して再熱蒸気系統３２に案内される。再熱蒸気系統３２の低温再熱蒸気管３３から第１再熱器１２に導かれた高圧タービン排気蒸気はここで第１段の再熱作用を受け、この再熱後に第１再熱器１２から再熱蒸気温度制御を行なう減温器３４を経て第２再熱器１１に案内される。第１再熱器１２および第２再熱器１１を通る間に再熱された再熱蒸気は、続いて高温再熱蒸気管３５を通って中圧タービン２８に導かれ、この中圧タービン２８を駆動させる。中圧タービン２８を駆動して膨張した蒸気は続いて低圧タービン２９に案内され、ここで低圧タービン２９を駆動させる。このように、高圧タービン２７、中圧タービン２８および低圧タービン２９を駆動させることにより回転軸５が回転駆動せしめられ、発電機４にて発電が行われる。
【００４５】
一方、低圧タービン２９で仕事をし、膨張した蒸気は、復水器４０に導かれ、この復水器４０で冷却され、復水となる。復水器４９で凝縮された復水は、復水給水系統４１の復水ポンプ４３、給水ポンプ４４にて昇圧され、昇圧された給水は、排熱回収ボイラ１の第１中圧節炭器２３、および第１高圧節炭器２２に送られる。
【００４６】
第１中圧節炭器２３に送られた給水は、この節炭器２３で加熱されて低圧ドラム２６に送られる一方、第２中圧節炭器１９を経て中圧ドラム２５に送られる。各ドラム２６，２５には低圧蒸発器２１および中圧蒸発器１８が接続され、これらの蒸発器２１，１８で給水は加熱され、蒸発される。低圧蒸発器２１および中圧蒸発器１８で加熱された流体（気液混合流体）は、各ドラム２６，２５内に戻されて、気液分離される。
【００４７】
低圧ドラム２６で気液分離された低圧蒸気は、続いて低圧過熱器１７に導かれ、この低圧過熱器１７で過熱され、低圧過熱蒸気（乾き蒸気）となって低圧蒸気供給系統（低圧過熱蒸気供給系）３８により低圧タービン２９に導かれる。
【００４８】
また、中圧ドラム２５で気液分離された中圧蒸気は、中圧過熱器１５に導かれ、この中圧過熱器１５で中圧過熱蒸気となって冷却蒸気系統４７の冷却蒸気供給系統４８に導かれる。
【００４９】
一方、第１高圧節炭器２２に導かれた給水は、この高圧節炭器２２、第２高圧節炭器２０および第３高圧節炭器１６を通って順次加熱され、高圧ドラム２４に導かれる。この高圧ドラム２４に案内された加熱流体は高圧蒸発器１４で加熱され、蒸気化され、気液二層流となって高圧ドラム２４内に戻され、高圧ドラム２４内で気液分離される。
【００５０】
高圧ドラム２４で気液分離された蒸気は、続いて第１高圧過熱器１３から減温器６６を経て第２高圧過熱器１０に案内される。両過熱器１３，１０で過熱された過熱蒸気は続いて高圧タービン２７に導かれ、再び蒸気タービンの駆動に供される。
【００５１】
ところで、このコンバインドサイクル発電プラントにおいては、高圧タービン２７からの再熱蒸気系統３２および中圧過熱器１５からの中圧蒸気系統（中圧過熱蒸気系統）５４に、ガスタービン高温部４６の冷却蒸気系統４７が接続されており、この冷却蒸気系統４７の冷却蒸気供給系統４８に高圧タービン２７からの排気蒸気（一部）および中圧過熱器１５からの中圧過熱蒸気が冷却蒸気として案内される。
【００５２】
この冷却蒸気は、ガスタービン８の高温部４６に導かれてガスタービン高温部４６を冷却する。冷却後の蒸気は冷却蒸気回収系統４９にて回収される。
【００５３】
この冷却蒸気回収系統４９は、冷却後の蒸気をボイラ回収系統５５を通して排熱回収ボイラ１の冷却蒸気再熱器５６に導き、この再熱器５６で冷却後の蒸気を再熱させる。再熱手段としての冷却蒸気再熱器５６で再熱された蒸気は続いてタービン回収系統５７に案内されて中圧タービン２８に導かれる。
【００５４】
このコンバインドサイクル発電プラントにおいては、冷却蒸気系統４７を備え、ガスタービン高温部４６を冷却した後の回収蒸気を、排熱回収ボイラ１にて再熱し、再熱蒸気温度（中圧タービン入口蒸気温度）を所望の温度とすることが可能となる。したがって、ガスタービン８側の制約によらず、再熱蒸気温度、すなわち中圧タービン入口温度を所望の温度とすることができ、タービンの出力制御が容易になる。
【００５５】
図２は、本発明に係るコンバインドサイクル発電プラントの第２実施形態を概略的に示す系統図である。
【００５６】
この実施形態に示されたコンバインドサイクル発電プラントは、第１実施形態に示されたものと、ガスタービンの冷却蒸気系統４７のうち、冷却蒸気回収系統７０が基本的に相違し、他の構成は実質的に同一であり、異ならないので、同一符号を付して重複する部分についての説明は省略する。
【００５７】
第２実施形態に示されたコンバインドサイクル発電プラントにおいて、ガスタービン８の冷却蒸気系統４７を構成する冷却蒸気供給系統４８は第１実施形態に示されたものと同様であるが、その冷却蒸気回収系統４９は異にする。冷却蒸気回収系統７０は蒸気タービンプラント３の再熱蒸気系統３２の低温側である低温再熱蒸気管３３に、ガスタービン冷却蒸気流量調節弁を兼ねる再熱蒸気流量調節弁３７の下流の合流点Ｃ2 で接続される。この冷却蒸気回収系統７０によりガスタービン高温部４６を冷却した蒸気を、再熱蒸気系統３２に回収させるようになっている。
【００５８】
この冷却蒸気回収系統７０は、ガスタービン８の高温部４６を冷却した冷却蒸気を回収するようになっており、ガスタービン冷却後の蒸気は、冷却蒸気回収系統７０を通って再熱蒸気系統３２の低温再熱蒸気管３３に導かれて高圧タービン排気蒸気である低温再熱蒸気と合流する。合流した冷却後の蒸気は低温再熱蒸気と混合して第１再熱器１２から減温器３４を経て第２再熱器１１に導かれ、両再熱器１１，１２で加熱されて再熱蒸気となる。この再熱蒸気は、再熱蒸気系統３２の高温再熱蒸気管３５より、再熱組合せ弁３６を経て蒸気タービンの中圧タービン２８に供給され、この中圧タービン２８を駆動させて膨張仕事をする。
【００５９】
このコンバインドサイクル発電プラントにおいては、ガスタービン８の高温部４６を冷却した後の冷却蒸気を冷却蒸気回収系統７０により再熱蒸気系統３２の低温側に導いて回収し、高圧タービン２７からの排気蒸気である低温再熱蒸気と合流させる。
【００６０】
低温再熱蒸気に合流せしめられたガスタービン冷却後の蒸気は混合蒸気となって排熱回収ボイラ１に案内され、排熱回収ボイラ１内に設置された第１再熱器１２と第２再熱器１１で再熱され、再熱蒸気となる。再熱蒸気は、両再熱器１２，１１の間に減温器３４を設置することで、再熱蒸気の温度制御が可能となり、中圧タービン２８に案内される再熱蒸気温度を所望の温度にすることができる。
【００６１】
なお、排熱回収ボイラ１内に第１再熱器１２と第２再熱器１１をセパレートさせ必要は必ずしもなく、１つの再熱器を設置するものであってもよい。この場合には、再熱器の下流側に再熱蒸気温度を制御する減温器が設けられる。
【００６２】
図３は、本発明に係るコンバインドサイクル発電プラントの第３実施形態を概略的に示す系統図である。
【００６３】
この実施形態に示されたコンバインドサイクル発電プラントは、第１実施形態に示されたものと、ガスタービン８の冷却蒸気系統のうち、冷却蒸気回収系統７１が基本的に相違し、他の構成は実質的に同一であり、異ならないので、同一符号を付して重複する部分についての説明は省略する。
【００６４】
第３実施形態に湿されたコンバインドサイクル発電プラントにおいて、ガスタービン８の冷却蒸気系統４７を構成する冷却蒸気供給系統４８は第１実施形態に示されたものと異ならない。冷却蒸気回収系統７１は、蒸気タービンプラント３の再熱蒸気系統３２の減温器３４上流側に接続される。すなわち、ガスタービン高温部４６の出口側に接続された冷却蒸気回収系統７１は、第１再熱器１２と減温器３４の間の合流点Ｃ3 で再熱蒸気系統３２に接続され、ガスタービン高温部４６冷却後の蒸気が再熱蒸気と合流せしめられる。
【００６５】
図３に示されたコンバインドサイクル発電プラントにおいては、ガスタービン高温部４６冷却後の蒸気を冷却蒸気回収系統７１により減温器３４の上流側に回収させ、この回収蒸気を排熱回収ボイラ１にて再熱し、再熱蒸気温度（中圧タービン入口蒸気温度）を所望の温度にして中圧タービン２８に供給するようにしたものである。
【００６６】
この場合、ガスタービン冷却蒸気を蒸気タービンプラントの再熱蒸気系統３２の減温器３４上流側に混合させるので、ガスタービン８の排ガス温度が上昇した場合の再熱蒸気の温度制御が容易である。また、ガスタービン８の冷却蒸気の回収温度が蒸気タービンの排気蒸気温度よりも高い場合には、蒸気タービン排気蒸気を再熱器１２にて再加熱した後にガスタービン冷却蒸気と合流させることで、合流部Ｃ3 における温度ミスマッチを抑えることが可能となる。
【００６７】
図４は、本発明に係るコンバインドサイクル発電プラントの第４実施形態を概略的に示す系統図である。
【００６８】
この実施形態に示されたコンバインドサイクル発電プラントは、第１実施形態に示されたものと、ガスタービン８の冷却蒸気回収系統７２が基本的に相違し、他の構成は実質的に同一であり、異ならないので、同一符号を付して重複する部分についての説明は省略する。
【００６９】
第４実施形態に示されたコンバインドサイクル発電プラントにおいて、ガスタービン８の冷却蒸気系統４７を構成する冷却蒸気供給系統４８は第１実施形態に示されたものと異ならない。冷却蒸気系統４７の冷却蒸気回収系統７２は蒸気タービンプラント３の再熱蒸気系統３２の減温器３４下流側（出口側）に接続される。すなわち、ガスタービン高温部４６の出口側に接続された冷却蒸気回収系統７２は減温器３４と第２再熱器１１の間の合流点Ｃ4 で再熱蒸気系統３２に接続され、ガスタービン高温部冷却後の蒸気が減温器下流側で再熱蒸気と合流せしめられる。
【００７０】
このコンバインドサイクル発電プラントは、ガスタービン高温部４６を冷却した蒸気を冷却蒸気回収系統７２により蒸気タービンプラント３の減温器３４の下流側に回収させ、排熱回収ボイラ１で蒸気タービンの排気蒸気とともに再加熱されるようにしたものである。
【００７１】
このコンバインドサイクル発電プラントは、冷却蒸気回収系統７２でガスタービン８の冷却後の蒸気を減温器３４の下流側に回収し、この回収蒸気を排熱回収ボイラ１にて再熱し、再熱蒸気温度（中圧タービン入口蒸気温度）を所望の温度とすることが可能となる。また、ガスタービン冷却蒸気を蒸気タービンプラント３の再熱蒸気系統３２の減温器３４下流側に回収させるので、減温器３４下流側に設置された再熱器１１分の圧力損失の増加だけでガスタービン冷却蒸気を再熱することが可能となる。
【００７２】
図５は、本発明に係るコンバインドサイクル発電プラントの第５実施形態を概略的に示す系統図である。
【００７３】
この実施形態に示されたコンバインドサイクル発電プラントは、第１実施形態に示されたものと、ガスタービン８の冷却蒸気回収系統７３が基本的に相違し、他の構成は実質的に異ならず同一なので、同一符号を付して重複する部分についての説明は省略する。
【００７４】
このコンバインドサイクル発電プラントにおいて、冷却蒸気系統４７の冷却蒸気供給系統４８は第１実施形態に示されたものと同様であるが、冷却蒸気回収系統７３は途中に減温器７４を備えて再熱蒸気系統３２の低温再熱蒸気管３３に合流点Ｃ5 で接続せしめられる。冷却蒸気回収系統７３はガスタービン８の高温部４６に接続される一方、その反対側が再熱蒸気系統３２の低温再熱蒸気管３３に再熱蒸気流量調整弁３７下流側の合流点Ｃ5 で接続され、ガスタービン高温部４６冷却後の蒸気を減温器７４で温度制御した後、再熱蒸気系統３２に回収させている。
【００７５】
図５に示されたコンバインドサイクル発電プラントにおいては、冷却蒸気回収系統７３に減温器７４を設け、この減温器７４にてガスタービン冷却後の蒸気を温度制御して、再熱蒸気系統３２に回収させ、この回収蒸気を蒸気タービン排気蒸気と合流させた後、排熱回収ボイラ１の再熱器１２，１１にて再熱し、中圧タービン３８に供給させる再熱蒸気温度を所望の温度にしている。この場合、冷却蒸気回収系統７３に減温器７４を設け、この減温器７４でガスタービン冷却蒸気の回収温度を制御することが可能となり、蒸気タービン排気蒸気との合流点Ｃ5 における温度ミスマッチを抑えることが可能となる。
【００７６】
図６は、本発明に係るコンバインドサイクル発電プラントの第６実施形態を概略的に示す系統図である。
【００７７】
この実施形態に示されたコンバインドサイクル発電プラントは、第１実施形態に示されたものと、ガスタービン８の冷却蒸気回収系統７５が基本的に相違し、他の構成は同一なので、同一符号を付して重複する部分についての説明は省略する。
【００７８】
このコンバインドサイクル発電プラントは、第１実施形態に示されたものと、冷却蒸気系統４７の冷却蒸気供給系統４８を同じくし、その冷却蒸気回収系統７５を異にする。冷却蒸気系統４７の冷却蒸気回収系統７５には減温器７６が備えられ、蒸気タービンプラント３の再熱蒸気系統３２に設けられた減温器３４上流側に、合流点Ｃ6 で接続される。冷却蒸気回収系統７５はガスタービン高温部４６に接続されてガスタービン８冷却後の蒸気を減温器７６に案内し、蒸気温度を制御した後、蒸気タービンプラント３の再熱蒸気系統３２に再熱器１２と減温器３４の間で回収するようになっている。
【００７９】
再熱蒸気系統３２に回収された回収蒸気は、第１再熱器１２で再熱された蒸気タービン排気蒸気と混合せしめられて排熱回収ボイラ１の第２再熱器１１で再び加熱されて再熱蒸気温度が所望の蒸気温度に調整されて中圧タービン２８に供給されるようになっている。
【００８０】
このコンバインドサイクル発電プラントにおいては、冷却蒸気供給系統７５に減温器７６を備えて、ガスタービン冷却後の蒸気温度を制御した後、ガスタービン冷却後の蒸気を再熱蒸気系統３２に減温器３４上流側で回収させ、回収蒸気温度と蒸気タービン排気温度とのミスマッチを防止する一方、回収蒸気は第１再熱器１２で再熱された低温再熱蒸気と合流せしめられ、減温器３４で全体の蒸気温度がコントロールされた後、排熱回収ボイラ１の第２再熱器１１で再熱され、所望する再熱蒸気温度となって中圧タービン２８に供給される。
【００８１】
この冷却蒸気回収系統７５は、ガスタービン冷却蒸気を蒸気タービン排気蒸気の再熱蒸気系統３２の減温器３４の上流側に混合するので、ガスタービンの排ガス温度が上昇した場合の再熱蒸気の温度制御が容易である。また、ガスタービン冷却蒸気の回収温度を減温器７６で制御することが可能となり、蒸気タービン排気蒸気との合流点Ｃ6 における温度ミスマッチを抑えることが可能となる。
【００８２】
図７は、本発明に係るコンバインドサイクル発電プラントの第７実施形態を概略的に示す系統図である。
【００８３】
この実施形態に示されたコンバインドサイクル発電プラントは、第１実施形態に示されたものと、ガスタービン８の冷却蒸気回収系統７７が基本的に相違し、他の構成は実質的に異ならず、同一であるので、同一符号を付して重複する部分についての説明は省略する。
【００８４】
このコンバインドサイクル発電プラントは、第１実施形態に示されたものと、冷却蒸気系統４７の冷却蒸気供給系統４８を同じくし、冷却蒸気回収系統７７を異にする。冷却蒸気系統４７の冷却蒸気回収系統７７には減温器７８が備えられて、蒸気タービンプラント３の再熱蒸気系統３２に、減温器３４下流側の合流点Ｃ7 で接続される。冷却蒸気回収系統７７はガスタービン高温部４６に接続されてガスタービン冷却後の蒸気を減温器７８に案内し、蒸気温度を制御した後、減温器３４下流側で再熱蒸気系統３２に回収させている。
【００８５】
再熱蒸気系統３２に回収された回収蒸気は、排熱回収ボイラ１の第２再熱器１１で蒸気タービン排気蒸気とともに再熱されて所望する温度の再熱蒸気となって中圧タービン２８に供給されるようになっている。
【００８６】
このコンバインドサイクル発電プラントにおいては、冷却蒸気回収系統７７に減温器７８を備えてガスタービン８冷却後の蒸気を減温器７８で温度制御した後、蒸気タービン排気蒸気と減温器３４下流側で合流せしめられて回収し、排熱回収ボイラ１の第２再熱器１１で再熱し、所望する温度の再熱蒸気にして高温再熱蒸気管３５から再熱組合せ弁３６を経て中圧タービンに供給することができる。
【００８７】
ガスタービン冷却後の蒸気回収温度を減温器７８で制御することが可能となり、蒸気タービン排気蒸気との合流点における温度ミスマッチを抑えることが可能となる。また、ガスタービン冷却蒸気を蒸気タービン排気蒸気の再熱系統の減温器の下流側に混合するので、減温器下流に設置された再熱器分の圧損の増加だけでガスタービン冷却蒸気を再熱することが可能となる。
【００８８】
図８は、本発明に係るコンバインドサイクル発電プラントの第８実施形態を概略的に示す系統図である。
【００８９】
この実施形態に示されたコンバインドサイクル発電プラントは、第１実施形態に示されたものと、ガスタービン８の冷却蒸気回収系統８０が基本的に相違し、他の構成は同一で実質的に異ならないので、同一符号を付して重複する部分についての説明は省略する。
【００９０】
このコンバインドサイクル発電プラントにおいては、第１実施形態に示されたものと、冷却蒸気系統４７の冷却蒸気供給系統４８を同じくし、その冷却蒸気回収系統８０を異にする。冷却蒸気回収系統８０には、ガスタービン冷却蒸気再熱器８１が備えられる。この再熱器８１は排熱回収ボイラ１内に設置され、例えば第１再熱器１２と第１高圧加熱器１３の間に配置される。
【００９１】
冷却蒸気系統４７の冷却蒸気回収系統８０はガスタービン高温部４６の出口側に一方が接続され、途中にガスタービン冷却蒸気再熱器８１を備えて他方が蒸気タービンプラント３の再熱蒸気系統３２に、減温器３４上流側の合流点Ｃ8 で接続される。
【００９２】
このコンバインドサイクル発電プラントにおいては、ガスタービン高温部４６を冷却した後、冷却後の蒸気を、冷却蒸気回収系統８０のガスタービン冷却蒸気再熱器８１に案内して再熱し、この再熱後に減温器３４出口側合流点Ｃ8 にて低温再熱蒸気に合流させて再熱蒸気系統３２に回収させる。低温再熱蒸気と合流せしめられた回収蒸気は、減温器３４で温度制御された後、排熱回収ボイラ１内の第２再熱器１１で再熱されて所望温度の再熱蒸気となり、高温再熱蒸気管３５により再熱組合せ弁３６を経て中圧タービン２８に供給される。
【００９３】
このコンバインドサイクル発電プラントにおいては、冷却蒸気系統４７の冷却蒸気回収系統８０にガスタービン冷却蒸気再熱器８１を備え、ガスタービン８冷却後の蒸気を排熱回収ボイラ１内の再熱器８１で再熱することで、あるいは再熱した回収蒸気温度が高くなりすぎる場合は、再熱器８１で再熱した後、図示しない減温器にて温度制御することで、蒸気タービン排気蒸気の再熱蒸気系統３２との合流点Ｃ8 における温度ミスマッチを抑えることが可能となる。減温器は冷却蒸気回収系統８０の冷却蒸気再熱器８１下流側に必要に応じて設置される。また、ガスタービン冷却蒸気を蒸気タービン排気蒸気の再熱蒸気系統３２の減温器３４上流側に混合するので、ガスタービンの排ガス温度が上昇した場合の再熱蒸気の温度制御が容易である。
【００９４】
図９は、本発明に係るコンバインドサイクル発電プラントの第９実施形態を概略的に示す系統図である。
【００９５】
この実施形態に示されたコンバインドサイクル発電プラントは、第１実施形態に示されたものと、ガスタービン８の冷却蒸気回収系統８３が基本的に相違し、他の構成は同一なので、同一符号を付して重複する部分についての説明は省略する。
【００９６】
このコンバインドサイクル発電プラントは、第１実施形態に示されたものと、冷却蒸気系統４７の冷却蒸気供給系統４８を同じくし、その冷却蒸気回収系統８３を異にする。冷却蒸気回収系統８３には、ガスタービン冷却蒸気再熱器８４と減温器８５とが直列接続状態に備えられる。冷却蒸気回収系統８３は、一方がガスタービン８の高温部４６の出口側に接続され、他方が蒸気タービンプラント３の再熱蒸気系統３２に、減温器３４下流側で接続される。
【００９７】
そして、ガスタービン８の冷却蒸気回収系統８３により、ガスタービン高温部４６冷却後の蒸気を、再熱器８４で再熱し、減温器８５で温度制御して再熱蒸気系統３２の減温器３４下流側（出口部）で低温再熱蒸気に合流せしめ、回収させ、この回収蒸気を排熱回収ボイラ１内の第２再熱器１１で再熱させることにより、再熱蒸気温度を所望の温度とすることができる。
【００９８】
この冷却蒸気回収系統８３に、ガスタービン冷却蒸気再熱器８４と減温器８５とを備えることで、ガスタービン冷却蒸気の回収蒸気温度を再熱器８４で再熱したり、また、回収蒸気温度の変動幅が大きい場合は、再熱器８４と減温器８５にて温度制御することで、蒸気タービンプラント３の再熱蒸気系統３２との合流点Ｃ9 における温度ミスマッチを抑えることが可能となる。また、冷却蒸気回収系統８３を蒸気タービンプラント３の再熱蒸気系統３２の減温器３４の下流側に接続し、ガスタービン冷却後の蒸気を減温器３４の下流側で低温再熱蒸気と混合するので、減温器３４下流に設置された再熱器１１分の圧力損失の増加だけでガスタービン冷却蒸気を再熱することが可能となる。
【００９９】
なお、各実施形態に示されたコンバインドサイクル発電プラントにおいては、ガスタービンプラントと蒸気タービンプラントが共通軸を有する一軸型の例を示したが、ガスタービンプラントと蒸気タービンプラントとにそれぞれ発電機を備えた多軸型のコンバインドサイクル発電プラントに適用してもよい。
【０１００】
また、排熱回収ボイラ内に加熱器や再熱器、節炭器をセパレートさせて複数台設置した例を示したが、加熱器や再熱器、節炭器の設置台数はコンバインドサイクル発電プラントの発電容量等に応じて種々の変形が考えられ、１台以上であればよい。
【０１０１】
【発明の効果】
以上に述べたように本発明に係るコンバインドサイクル発電プラントにおいては、ガスタービン高温部に冷却蒸気供給系統により蒸気タービンの排気蒸気（一部）を案内し、ガスタービンを蒸気冷却により有効的かつ効率よく冷却する一方、ガスタービン冷却後の蒸気を排熱回収ボイラ内で再熱し、蒸気タービンプラントの再熱蒸気系統に回収するようしたので、ガスタービン冷却蒸気の回収温度如何によらず、所望する再熱蒸気温度に調整して蒸気タービンの中圧タービンに供給することができ、タービン出力制御が容易になる。
【図面の簡単な説明】
【図１】本発明に係るコンバインドサイクル発電プラントの第１実施形態を示すプラント通常運転時の概略系統図。
【図２】本発明に係るコンバインドサイクル発電プラントの第２実施形態を示すプラント通常運転時の概略系統図。
【図３】本発明に係るコンバインドサイクル発電プラントの第３実施形態を示すプラント通常運転時の概略系統図。
【図４】本発明に係るコンバインドサイクル発電プラントの第４実施形態を示すプラント通常運転時の概略系統図。
【図５】本発明に係るコンバインドサイクル発電プラントの第５実施形態を示すプラント通常運転時の概略系統図。
【図６】本発明に係るコンバインドサイクル発電プラントの第６実施形態を示すプラント通常運転時の概略系統図。
【図７】本発明に係るコンバインドサイクル発電プラントの第７実施形態を示すプラント通常運転時の概略系統図。
【図８】本発明に係るコンバインドサイクル発電プラントの第８実施形態を示すプラント通常運転時の概略系統図。
【図９】本発明に係るコンバインドサイクル発電プラントの第９実施形態を示すプラント通常運転時の概略系統図。
【符号の説明】
１排熱回収ボイラ
２ガスタービンプラント
３蒸気タービンプラント
４発電機
５回転軸
６空気圧縮機
７燃焼器
８ガスタービン
９ケーシング
１０第２高圧過熱器
１１第２再熱器
１２第１再熱器
１３第１高圧過熱器
１４高圧蒸発器
１５中圧過熱器
１６第３高圧節炭器
１７低圧過熱器
１８中圧蒸発器
１９第２中圧節炭器
２０第２高圧節炭器
２１低圧蒸発器
２２第１高圧節炭器
２３第１中圧節炭器
２４高圧ドラム
２５中圧ドラム
２６低圧ドラム
２７高圧タービン（蒸気タービン）
２８中圧タービン（蒸気タービン）
２９低圧タービン（蒸気タービン）
３０高圧加減弁
３１主蒸気系統（過熱蒸気系統）
３２再熱蒸気系統
３３低温再熱蒸気管
３４減温器
３５高温再熱蒸気管
３６再熱組合せ弁
３７再熱主蒸気流量調節弁（ガスタービン冷却蒸気流量調節弁）
３８低圧蒸気供給系統
３９低圧蒸気組合せ弁
４０復水器
４１復水給水系統
４３復水ポンプ
４４給水ポンプ
４６ガスタービン高温部
４７冷却蒸気系統
４８冷却蒸気供給系統
４９冷却蒸気回収系統
５０冷却蒸気バイパス系統
５１バイパス蒸気弁
５３逆止弁
５４中圧蒸気系統
５５ボイラ回収系統
５６冷却蒸気再熱器（再熱手段）
５７タービン回収系統
６０高圧タービンバイパス系統
６１中圧タービンバイパス系統
６２低圧タービンバイパス系統
６３高圧タービンバイパス弁
６４中圧タービンバイパス弁
６５低圧タービンバイパス弁
６６減温器
７０，７１，７２冷却蒸気回収系統
７３，７５，７７，８０冷却蒸気回収系統
７４，７６，７８，８５減温器
８１，８４冷却蒸気再熱器[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a combined cycle power plant that uses steam as a cooling medium for cooling a high temperature portion of a gas turbine.
[0002]
[Prior art]
In recent thermal power plants, many combined cycle power plants that combine a gas turbine plant, a steam turbine plant, and an exhaust heat recovery boiler are operated as actual machines in order to improve plant thermal efficiency. The plant thermal efficiency of this combined cycle power plant is calculated from the ratio of the total heat output of each plant to the total heat input of each plant of the gas turbine plant, steam turbine plant, and exhaust heat recovery boiler. When the steam turbine plant, exhaust heat recovery boiler and gas turbine plant are reviewed from the viewpoint of improving the plant thermal efficiency, the steam turbine and exhaust heat recovery boiler have already reached their limits, and the improvement of the thermal efficiency of the gas turbine plant is combined cycle power generation. It is expected to improve the plant thermal efficiency of the plant.
[0003]
The gas turbine plant can improve the thermal efficiency as the gas combustion temperature at the gas turbine is higher. The progress of cooling technology coupled with the recent development of heat-resistant materials has made it possible to reduce the gas combustion temperature at the gas turbine. It is shifting from the 1000 ° C class to the 1500 ° C class or higher through the 1300 ° C class.
[0004]
When the temperature of the combustion gas at the inlet of the gas turbine is set to 1500 ° C. or higher, although a heat-resistant material has been developed, a gas turbine high temperature part, for example, a gas turbine stationary blade, a gas turbine moving blade, The allowable metal temperature of the liner and transition piece of the container has already reached its limit, and there is a risk of accidents such as material breakage and melting during operation with many start / stop operations and continuous operation over a long period of time. .
[0005]
For this reason, even if the inlet combustion gas temperature of the gas turbine is increased, the gas turbine hot section is used by using air in parallel with the development of heat resistant materials as a technology that can be maintained within the allowable metal temperature of each component of the gas turbine hot section. The development of cooling technology for cooling the air has already been realized as a practical machine.
[0006]
However, when cooling the gas turbine high-temperature part using air, the cooling air supply source is obtained from the air compressor directly connected to the gas turbine, and therefore, it is several tens of percent supplied from the air compressor to the gas turbine. The high-pressure air is used for cooling the high-temperature part of the gas turbine, and is blown into the high-temperature gas after cooling the turbine blades. This causes a decrease in the temperature of the working gas and mixing loss, which is not preferable in terms of improving the plant thermal efficiency.
[0007]
Recently, the use of steam as a cooling medium has been reviewed in the high temperature section of a gas turbine plant, for example, a gas turbine stationary blade, a gas turbine blade, etc., and has already been reviewed by the American Society of Mechanical Engineers (ASME paper, 92-GT-240). And Japanese Patent Laid-Open No. 5-163961.
[0008]
Steam has a specific heat approximately twice that of air and has excellent heat transfer performance, so it is possible to cool the closed loop and eliminate the temperature drop and mixing loss of the working gas, contributing to the improvement of plant efficiency. Application to practical machines is expected.
[0009]
[Problems to be solved by the invention]
In a combined cycle power plant, when steam is supplied as a cooling medium to a gas turbine high temperature section, the steam is recovered by the steam turbine after cooling the gas turbine high temperature section, but the recovery temperature depends on the cooling performance of the gas turbine. Therefore, the reheat steam temperature (intermediate pressure turbine inlet temperature) is restricted.
[0010]
The present invention has been made in consideration of the above-described circumstances, and can reheat steam after cooling the gas turbine and effectively and efficiently obtain a desired reheat steam temperature regardless of the restrictions on the gas turbine side. It aims at providing the combined cycle power plant which can be performed.
[0011]
Another object of the present invention is to provide a combined cycle power plant that improves the cooling performance of a gas turbine and reheats the steam after cooling the gas turbine to obtain a desired reheat steam temperature and facilitates turbine output control. It is in.
[0012]
[Means for Solving the Problems]
In order to solve the above-described problem, a combined cycle power plant according to the present invention, as described in claim 1, uses a gas turbine plant equipped with a gas turbine and exhaust gas from the gas turbine to generate steam. An exhaust heat recovery boiler to be generated, a steam turbine plant that uses steam generated in the exhaust heat recovery boiler as a driving source of the steam turbine, and an inlet side of the gas turbine high-temperature section are connected to cool the exhaust steam from the steam turbine. In a combined cycle power plant equipped with a cooling steam supply system for supplying steam, a cooling steam recovery system connected to the outlet side of the gas turbine high temperature section and recovering the steam after cooling the gas turbine is provided. Is a boiler recovery system that directs steam after cooling to the exhaust heat recovery boiler, and after cooling the gas turbine And reheating reheater steam at exhaust heat recovery boiler, the reheat steam and the turbine recovery system for recovering the said steam turbine The cooling steam recovery system is provided with a temperature reducer downstream of the reheater, and the reheat steam temperature is controlled by this temperature reducer. Is.
[0014]
Furthermore, the combined cycle power plant according to the present invention, in order to solve the problems described above, Claim 2 As described above, a gas turbine plant equipped with a gas turbine, an exhaust heat recovery boiler that generates steam using exhaust gas from the gas turbine, and steam generated by the exhaust heat recovery boiler is driven by the steam turbine. In a combined cycle power plant having a steam turbine plant as a source and a cooling steam supply system connected to an inlet side of the gas turbine high temperature section and supplying exhaust steam from the steam turbine as cooling steam, the gas turbine high temperature section The cooling steam recovery system is connected to the outlet side of the steam turbine, and this cooling steam recovery system recovers the steam after cooling the high-temperature part of the gas turbine on the way to the low temperature side of the reheat steam system of the steam turbine plant. .
[0015]
Furthermore, the combined cycle power plant according to the present invention, in order to solve the problems described above, Claim 3 As described above, a gas turbine plant equipped with a gas turbine, an exhaust heat recovery boiler that generates steam using exhaust gas from the gas turbine, and steam generated by the exhaust heat recovery boiler is used as a drive source for the steam turbine. In the combined cycle power plant having a steam turbine plant and a cooling steam supply system connected to the inlet side of the gas turbine high temperature section and supplying exhaust steam from the steam turbine as cooling steam, the gas turbine high temperature section The cooling steam recovery system is connected to the outlet side of the gas turbine, and this cooling steam recovery system is configured to supply steam after cooling the high-temperature part of the gas turbine on the way to a desuperheater installed in the reheat steam system of the steam turbine plant. It is collected upstream.
[0016]
Furthermore, the combined cycle power plant according to the present invention is to solve the above-described problems, Claim 4 As described above, a gas turbine plant equipped with a gas turbine, an exhaust heat recovery boiler that generates steam using exhaust gas from the gas turbine, and steam generated by the exhaust heat recovery boiler is driven by the steam turbine. In a combined cycle power plant having a steam turbine plant as a source and a cooling steam supply system connected to an inlet side of the gas turbine high temperature section and supplying exhaust steam from the steam turbine as cooling steam, the gas turbine high temperature section The cooling steam recovery system is connected to the outlet side of the steam turbine, and this cooling steam recovery system uses a steam reducer installed in the reheat steam system of the above steam turbine plant for the steam after cooling the high-temperature portion of the gas turbine. It is collected on the downstream side.
[0017]
Furthermore, the combined cycle power plant according to the present invention, in order to solve the problems described above, Claim 5 As described above, a gas turbine plant equipped with a gas turbine, an exhaust heat recovery boiler that generates steam using exhaust gas from the gas turbine, and steam generated by the exhaust heat recovery boiler is driven by the steam turbine. In a combined cycle power plant having a steam turbine plant as a source and a cooling steam supply system connected to the inlet side of the gas turbine high temperature section and supplying exhaust steam of the steam turbine as cooling steam, the gas turbine high temperature section A cooling steam recovery system connected to the outlet side, and this cooling steam recovery system includes a temperature reducer that controls the temperature of the steam after cooling the gas turbine in the middle, and the low temperature of the reheat steam system of the steam turbine plant The steam after cooling the gas turbine is recovered on the low temperature side of the reheat steam system.
[0018]
Moreover, in order to solve the above-described problem, the combined cycle power plant according to the present invention, Claim 6 As described above, a gas turbine plant including a gas turbine, an exhaust heat recovery boiler that generates steam using exhaust gas from the gas turbine, and steam generated in the exhaust heat recovery boiler is used as a drive source for the steam turbine. In the combined cycle power plant having a steam turbine plant and a cooling steam supply system connected to the inlet side of the gas turbine high temperature section and supplying exhaust steam from the steam turbine as cooling steam, the gas turbine high temperature section The cooling steam recovery system is connected to the outlet of the steam turbine, and the cooling steam recovery system includes a temperature reducer that controls the temperature of the steam after cooling the gas turbine in the middle to reduce the temperature of the reheat steam system of the steam turbine plant. It is connected to the upstream side of the cooler, and the steam after cooling the gas turbine is recovered upstream of the temperature reducer.
[0019]
Furthermore, the combined cycle power plant according to the present invention, in order to solve the problems described above, Claim 7 As described in 1., a gas turbine plant equipped with a gas turbine, an exhaust heat recovery boiler that generates steam using exhaust gas from the steam gas turbine, and steam generated by the exhaust heat recovery boiler is driven by the steam turbine. In a combined cycle plant having a steam turbine plant as a source and a cooling steam supply system connected to an inlet side of the gas turbine high temperature section and supplying exhaust steam from the steam turbine as cooling steam, the gas turbine high temperature section It has a cooling steam recovery system connected to the outlet side, and this cooling steam recovery system is connected to the downstream side of the reheat steam system with a desuperheater that controls the temperature of the steam after cooling the gas turbine. The steam after cooling the gas turbine is recovered downstream of the temperature reducer.
[0020]
Furthermore, the combined cycle power plant according to the present invention, in order to solve the problems described above, Claim 8 As described above, a gas turbine plant equipped with a gas turbine, an exhaust heat recovery boiler that generates steam using exhaust gas from the gas turbine, and steam generated by the exhaust heat recovery boiler is driven by the steam turbine. In a combined cycle power plant having a steam turbine plant as a source and a cooling steam supply system connected to an inlet side of the gas turbine high temperature section and supplying exhaust steam from the steam turbine as cooling steam, the gas turbine high temperature section The cooling steam recovery system is connected to the outlet side of the boiler, and this cooling steam recovery system is a reheat steam provided with a cooling steam reheater that reheats the steam after cooling the gas turbine in the exhaust heat recovery boiler. It is connected to the upstream side of the system desuperheater, and the steam after cooling the gas turbine is recovered upstream of this desuperheater.
[0021]
Furthermore, the combined cycle power plant according to the present invention is to solve the above-described problems, Claim 9 As described above, a gas turbine plant equipped with a gas turbine, an exhaust heat recovery boiler that generates steam using exhaust gas from the gas turbine, and steam generated by the exhaust heat recovery boiler is driven by the steam turbine. In a combined cycle power plant having a steam turbine plant as a source and a cooling steam supply system connected to an inlet side of the gas turbine high temperature section and supplying exhaust steam from the steam turbine as cooling steam, the gas turbine high temperature section The cooling steam recovery system is connected to the outlet side of the steam turbine, and the cooling steam recovery system includes a cooling steam reheater that reheats the steam after cooling the gas turbine in the exhaust heat recovery boiler. Connected to the downstream side of the desuperheater of the reheat steam system of the plant, and the steam after cooling the gas turbine was recovered downstream of this desuperheater A.
[0022]
Furthermore, in order to solve the above-mentioned problem, the combined cycle power plant according to the present invention is: Claim 10 As described above, the cooling steam recovery system is provided with a temperature reducer downstream of the cooling steam reheater, and the temperature of the reheated steam after cooling the gas turbine is controlled by the temperature reducer to reheat the steam turbine plant. It is collected in the steam system.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a combined cycle power plant according to the present invention will be described with reference to the accompanying drawings.
[0024]
FIG. 1 is a system diagram schematically showing a first embodiment of a combined cycle power plant according to the present invention.
[0025]
The present embodiment is a single-shaft combined cycle power plant in which the exhaust heat recovery boiler 1 is separately provided and the gas turbine plant 2, the steam turbine plant 3, and the generator 4 are directly connected to the same rotating shaft 5.
[0026]
The gas turbine plant 2 includes an air compressor 6, a combustor 7, and a gas turbine 8. The atmosphere sucked by the air compressor 6 is increased in pressure and guided to the combustor 7, and fuel is added to the high-pressure air for combustion. Combustion gas is generated, the combustion gas is guided to the gas turbine 8 to perform expansion work, and the exhaust gas (exhaust heat) after the expansion work is supplied to the exhaust heat recovery boiler 1 as a steam generation source. ing.
[0027]
The exhaust heat recovery boiler 1 includes a casing 9 extending in the axial direction, and a second high-pressure superheater 10, a second reheater 11, and a second reheater 11 are sequentially provided in the casing 9 along the flow of the combustion exhaust gas. 1 reheater 12, first high pressure superheater 13, high pressure evaporator 14, medium pressure superheater 15, third high pressure economizer 16, low pressure superheater 17, medium pressure evaporator 18, second medium pressure economizer 19, the 2nd high pressure economizer 20, the low pressure evaporator 21, the 1st high pressure economizer 22, and the 1st medium pressure economizer 23 are installed, respectively. Further, the high-pressure, medium- and low-pressure evaporators 14, 18, and 21 are connected to the high-pressure drum 24, the intermediate-pressure drum 25, and the low-pressure drum 26, respectively. Gas-liquid separation is performed in each drum 24, 25, 26.
[0028]
On the other hand, in the steam turbine plant 3, the steam turbine is divided into a high-pressure turbine 27, an intermediate-pressure turbine 28, and a low-pressure turbine 29, respectively. The superheated steam guided through the steam (superheated steam) system 31 is guided to the high-pressure turbine 27, and the high-pressure turbine 27 performs expansion work. The exhaust steam after the expansion work by the high-pressure turbine 27 is guided to the reheat steam system 32, and the first reheater 12, the temperature reducer 34, and the second reheater 11 are passed through the low temperature reheat steam pipe 33. To the intermediate pressure turbine 28 through the high temperature reheat steam pipe 35 and the reheat combination valve 36 of the reheat steam system 32, and the expanded steam is expanded by the intermediate pressure turbine 28. Let work. Reference numeral 37 denotes a reheat steam flow rate control valve provided in the low temperature reheat steam pipe 33 of the reheat steam system 32. The reheat steam flow rate control valve 37 also serves as a gas turbine cooling steam flow rate control valve.
[0029]
Further, the exhaust steam that has worked in the intermediate-pressure turbine 28 is guided to the low-pressure turbine 29 and is expanded in the low-pressure turbine 29, and the generator 4 is driven by the rotational power generated by the expansion work of the steam turbines 27, 28, and 29. It comes to drive.
[0030]
In addition, low pressure steam is guided to the low pressure turbine 29 from the low pressure superheater 17 of the exhaust heat recovery boiler 1 through the low pressure steam combination valve 39 of the low pressure steam supply system 38, and the rotation generated by the expansion work of the low pressure steam. The generator 4 is driven by power.
[0031]
Further, in the low pressure turbine 29, the exhaust steam after the expansion work is guided to the condenser 40, where it is condensed to condensate, and the condensed condensate is condensed into the condensate pump 43 and the feed pump of the condensate water supply system 41. The pressure is increased at 44. The downstream side of the feed water pump 44 is bifurcated and supplied to the first medium pressure economizer 23 and the first high pressure economizer 22 of the exhaust heat recovery boiler 1 as feed water.
[0032]
In this combined cycle power plant, a high temperature section 46 of the gas turbine 8, for example, a gas turbine stationary blade, a gas turbine moving blade, a liner of the combustor 7, a transition piece, and the like are provided with a cooling steam system 47. The cooling steam system 47 includes a cooling steam supply system 48, a cooling steam recovery system 49, and a cooling steam bypass system 50. The cooling steam bypass system 50 is provided with a normally closed bypass steam valve 51.
[0033]
On the other hand, the cooling steam supply system 48 is configured to be branched at a branch point A from the low temperature reheat steam pipe 33 of the high pressure turbine 27 to the first reheater 12. The cooling steam supply system 48 joins the intermediate pressure steam system 54 at the junction B through the check valve 53 and is connected to the inlet of the high temperature section 46 of the gas turbine 8. The intermediate pressure steam system 54 is connected to the intermediate pressure superheater 15, and the entire amount of steam generated in the intermediate pressure drum 25 is supplied.
[0034]
A cooling steam recovery system 49 is connected to the outlet side of the high temperature section 46 of the gas turbine 2, and the steam after cooling the gas turbine high temperature section 46 is recovered by the cooling steam recovery system 49.
[0035]
The cooling steam recovery system 49 includes a boiler recovery system 55 that guides the steam after cooling the gas turbine to the exhaust heat recovery boiler 1, and cooling steam re-operation as a reheating means for reheating the cooled steam in the exhaust heat recovery boiler 1. A heater 56 and a turbine recovery system 57 that recovers steam reheated while passing through the reheater 56 to the intermediate pressure turbine 28 of the steam turbine are provided. The turbine recovery system 57 is joined with the high-temperature reheat steam pipe 35 of the reheat steam system 32 at the junction C1. In the reheating means, a temperature reducer for controlling the reheat steam temperature is provided on the downstream side of the reheater 56 as necessary.
[0036]
In this combined cycle power plant, the steam generated from the exhaust heat recovery boiler 1 when the plant is started up until the pressure and temperature reach predetermined values, the high pressure turbine bypass system 60, the intermediate pressure turbine bypass system 61, and the low pressure turbine bypass system 62. Thus, the steam turbines 27, 28 and 29 are bypassed and guided to the condenser 40. Each turbine bypass system 60, 61, 62 is provided with normally closed high pressure, medium pressure, low pressure turbine bypass valves 63, 64, 65, respectively.
[0037]
Further, the cooling steam of the gas turbine of the cooling steam system 47 bypasses the gas turbine high temperature section 46 by the cooling steam bypass system 50 until reaching a predetermined pressure and temperature, and the cooling steam supply system 48 and the cooling steam recovery system 49. Warming up.
[0038]
Further, when the supply of the gas turbine cooling steam to the cooling steam system 47 is started, the supply pressure control of the gas turbine cooling steam is performed by the intermediate pressure turbine bypass valve 61 in order to keep the steam supply pressure at a set value.
[0039]
The flow rate of the gas turbine cooling steam is controlled by the gas turbine cooling steam flow rate adjusting valve 37 of the reheat steam system 32, and the supply temperature of the gas turbine cooling steam is controlled by the temperature reducer 66 controlling the temperature of the main steam. Do.
[0040]
Next, the operation of the combined cycle power plant will be described.
[0041]
In this combined cycle power plant, the gas turbine plant 2 and the steam turbine plant 3 cooperate to drive the generator 4 to generate power.
[0042]
The gas turbine plant 2 guides the high-pressure air compressed by the air conditioner 6 to the combustor 7 and is supplied with fuel in the liner of the combustor 7 to be combusted. Combustion gas from the combustor 7 is supplied to a gas turbine 8 through a transition piece, and the turbine rotor blades are driven by the gas turbine 8 to rotate the rotating shaft 5.
[0043]
The combustion exhaust gas expanded by driving the gas turbine 8 is subsequently guided to the exhaust heat recovery boiler 1, and steam that drives the steam turbines 27, 28, and 29 of the steam turbine plant 3 is driven by the exhaust heat recovery boiler 1. generate.
[0044]
The superheated steam superheated by the second high pressure superheater 10 of the exhaust heat recovery boiler 1 is guided to the high pressure turbine 27 through the main steam system (superheated steam system) 31 to drive the high pressure turbine 27. The steam that has worked by driving the high-pressure turbine 27 expands and is guided to the reheat steam system 32. The high-pressure turbine exhaust steam introduced from the low-temperature reheat steam pipe 33 of the reheat steam system 32 to the first reheater 12 is subjected to the first stage reheat action, and after this reheat, the first reheater 12 is reheated. To the second reheater 11 through a temperature reducer 34 that performs reheat steam temperature control. The reheat steam reheated while passing through the first reheater 12 and the second reheater 11 is then led to the intermediate pressure turbine 28 through the high temperature reheat steam pipe 35, and this intermediate pressure turbine 28. Drive. The steam expanded by driving the intermediate pressure turbine 28 is then guided to the low pressure turbine 29, where the low pressure turbine 29 is driven. Thus, by driving the high-pressure turbine 27, the intermediate-pressure turbine 28, and the low-pressure turbine 29, the rotary shaft 5 is driven to rotate, and the generator 4 generates power.
[0045]
On the other hand, the expanded steam that has worked in the low-pressure turbine 29 is guided to the condenser 40 and cooled by the condenser 40 to become condensed water. The condensate condensed in the condenser 49 is boosted by the condensate pump 43 and the feed pump 44 of the condensate feed system 41, and the boosted feed water is the first medium pressure economizer of the exhaust heat recovery boiler 1. 23 and the first high pressure economizer 22.
[0046]
The feed water sent to the first medium pressure economizer 23 is heated by this economizer 23 and sent to the low pressure drum 26, while being sent to the intermediate pressure drum 25 via the second medium pressure economizer 19. A low-pressure evaporator 21 and an intermediate-pressure evaporator 18 are connected to the drums 26 and 25, and the feed water is heated and evaporated by these evaporators 21 and 18. The fluid (gas-liquid mixed fluid) heated by the low-pressure evaporator 21 and the medium-pressure evaporator 18 is returned into the drums 26 and 25 to be gas-liquid separated.
[0047]
The low-pressure steam separated by the low-pressure drum 26 is then led to the low-pressure superheater 17 and is superheated by the low-pressure superheater 17 to become low-pressure superheated steam (dry steam) (low-pressure superheated steam). The supply system) 38 guides the low-pressure turbine 29.
[0048]
Further, the intermediate pressure steam separated by the intermediate pressure drum 25 is guided to the intermediate pressure superheater 15, and becomes the intermediate pressure superheated steam in the intermediate pressure superheater 15, and the cooling steam supply system 48 of the cooling steam system 47. Led to.
[0049]
On the other hand, the feed water led to the first high-pressure economizer 22 is sequentially heated through the high-pressure economizer 22, the second high-pressure economizer 20, and the third high-pressure economizer 16, and is introduced to the high-pressure drum 24. It is burned. The heated fluid guided to the high-pressure drum 24 is heated by the high-pressure evaporator 14, vaporized, returned to the high-pressure drum 24 as a gas-liquid two-layer flow, and gas-liquid separated in the high-pressure drum 24.
[0050]
The vapor that has been gas-liquid separated by the high-pressure drum 24 is then guided from the first high-pressure superheater 13 to the second high-pressure superheater 10 via the temperature reducer 66. The superheated steam superheated by both the superheaters 13 and 10 is subsequently led to the high-pressure turbine 27 and again used for driving the steam turbine.
[0051]
In this combined cycle power plant, the reheat steam system 32 from the high pressure turbine 27 and the medium pressure steam system (medium pressure superheat steam system) 54 from the intermediate pressure superheater 15 are connected to the cooling steam of the gas turbine high-temperature section 46. The system 47 is connected, and the exhaust steam (part) from the high-pressure turbine 27 and the medium-pressure superheated steam from the intermediate-pressure superheater 15 are guided to the cooling steam supply system 48 of the cooling steam system 47 as cooling steam. .
[0052]
The cooling steam is guided to the high temperature portion 46 of the gas turbine 8 to cool the gas turbine high temperature portion 46. The cooled steam is recovered by a cooling steam recovery system 49.
[0053]
The cooling steam recovery system 49 guides the cooled steam to the cooling steam reheater 56 of the exhaust heat recovery boiler 1 through the boiler recovery system 55, and reheats the cooled steam by the reheater 56. The steam reheated by the cooling steam reheater 56 as reheating means is then guided to the turbine recovery system 57 and guided to the intermediate pressure turbine 28.
[0054]
In this combined cycle power plant, a cooling steam system 47 is provided, and the recovered steam after cooling the gas turbine high-temperature portion 46 is reheated by the exhaust heat recovery boiler 1 to reheat steam temperature (medium pressure turbine inlet steam temperature). ) Can be set to a desired temperature. Therefore, regardless of the restrictions on the gas turbine 8 side, the reheat steam temperature, that is, the intermediate pressure turbine inlet temperature can be set to a desired temperature, and the output control of the turbine becomes easy.
[0055]
FIG. 2 is a system diagram schematically showing a second embodiment of the combined cycle power plant according to the present invention.
[0056]
The combined cycle power plant shown in this embodiment is basically different from the one shown in the first embodiment in the cooling steam recovery system 70 of the cooling steam system 47 of the gas turbine, and other configurations are the same. Since they are substantially the same and are not different, the description of the overlapping parts with the same reference numerals will be omitted.
[0057]
In the combined cycle power plant shown in the second embodiment, the cooling steam supply system 48 that constitutes the cooling steam system 47 of the gas turbine 8 is the same as that shown in the first embodiment. The system 49 is different. The cooling steam recovery system 70 is connected to a low-temperature reheat steam pipe 33 on the low temperature side of the reheat steam system 32 of the steam turbine plant 3 at a junction point downstream of the reheat steam flow control valve 37 that also functions as a gas turbine cooling steam flow control valve. Connected with C2. The steam that has cooled the gas turbine high temperature portion 46 by the cooling steam recovery system 70 is recovered by the reheat steam system 32.
[0058]
The cooling steam recovery system 70 is configured to recover the cooling steam that has cooled the high temperature portion 46 of the gas turbine 8, and the steam after cooling the gas turbine passes through the cooling steam recovery system 70 and the reheat steam system 32. The low-temperature reheat steam pipe 33 is led to join with the low-temperature reheat steam that is high-pressure turbine exhaust steam. The combined steam after cooling is mixed with the low-temperature reheated steam, led from the first reheater 12 to the second reheater 11 via the temperature reducer 34, heated by both reheaters 11, 12 and regenerated. It becomes hot steam. The reheat steam is supplied from the high temperature reheat steam pipe 35 of the reheat steam system 32 through the reheat combination valve 36 to the intermediate pressure turbine 28 of the steam turbine, and the intermediate pressure turbine 28 is driven to perform expansion work. To do.
[0059]
In this combined cycle power plant, the cooling steam after cooling the high temperature portion 46 of the gas turbine 8 is guided to the low temperature side of the reheat steam system 32 by the cooling steam recovery system 70 and recovered, and the exhaust steam from the high pressure turbine 27 is recovered. Combine with low temperature reheat steam.
[0060]
The steam after cooling the gas turbine combined with the low-temperature reheat steam becomes mixed steam and is guided to the exhaust heat recovery boiler 1, and the first reheater 12 installed in the exhaust heat recovery boiler 1 and the second reheat steam It is reheated by the heater 11 and becomes reheated steam. For the reheat steam, a temperature reducer 34 is installed between the reheaters 12 and 11 to enable temperature control of the reheat steam, and the reheat steam temperature guided to the intermediate pressure turbine 28 is set to a desired value. Can be temperature.
[0061]
It is not always necessary to separate the first reheater 12 and the second reheater 11 in the exhaust heat recovery boiler 1, and one reheater may be installed. In this case, a temperature reducer for controlling the reheat steam temperature is provided on the downstream side of the reheater.
[0062]
FIG. 3 is a system diagram schematically showing a third embodiment of the combined cycle power plant according to the present invention.
[0063]
The combined cycle power plant shown in this embodiment is basically different from that shown in the first embodiment in the cooling steam system of the gas turbine 8 in the cooling steam recovery system 71, and other configurations are the same. Since they are substantially the same and are not different, the description of the overlapping parts with the same reference numerals will be omitted.
[0064]
In the combined cycle power plant moistened in the third embodiment, the cooling steam supply system 48 constituting the cooling steam system 47 of the gas turbine 8 is not different from that shown in the first embodiment. The cooling steam recovery system 71 is connected to the upstream side of the temperature reducer 34 of the reheat steam system 32 of the steam turbine plant 3. That is, the cooling steam recovery system 71 connected to the outlet side of the gas turbine high temperature section 46 is connected to the reheat steam system 32 at the junction C3 between the first reheater 12 and the temperature reducer 34, and the gas turbine The steam after cooling the high temperature part 46 is combined with the reheated steam.
[0065]
In the combined cycle power plant shown in FIG. 3, the steam after cooling the gas turbine high-temperature portion 46 is recovered to the upstream side of the temperature reducer 34 by the cooling steam recovery system 71, and this recovered steam is supplied to the exhaust heat recovery boiler 1. The reheat steam temperature (medium pressure turbine inlet steam temperature) is set to a desired temperature and supplied to the intermediate pressure turbine 28.
[0066]
In this case, since the gas turbine cooling steam is mixed upstream of the desuperheater 34 of the reheat steam system 32 of the steam turbine plant, the temperature control of the reheat steam when the exhaust gas temperature of the gas turbine 8 rises is easy. . When the recovery temperature of the cooling steam of the gas turbine 8 is higher than the exhaust steam temperature of the steam turbine, the steam turbine exhaust steam is reheated by the reheater 12 and then merged with the gas turbine cooling steam, It is possible to suppress the temperature mismatch at the junction C3.
[0067]
FIG. 4 is a system diagram schematically showing a fourth embodiment of the combined cycle power plant according to the present invention.
[0068]
The combined cycle power plant shown in this embodiment is basically different from that shown in the first embodiment in the cooling steam recovery system 72 of the gas turbine 8, and the other configurations are substantially the same. Since they are not different from each other, the same reference numerals are given and descriptions of overlapping parts are omitted.
[0069]
In the combined cycle power plant shown in the fourth embodiment, the cooling steam supply system 48 constituting the cooling steam system 47 of the gas turbine 8 is not different from that shown in the first embodiment. The cooling steam recovery system 72 of the cooling steam system 47 is connected to the downstream side (outlet side) of the temperature reducer 34 of the reheat steam system 32 of the steam turbine plant 3. That is, the cooling steam recovery system 72 connected to the outlet side of the gas turbine high temperature section 46 is connected to the reheat steam system 32 at the junction C4 between the temperature reducer 34 and the second reheater 11, and the gas turbine high temperature The steam after partial cooling is combined with the reheated steam on the downstream side of the desuperheater.
[0070]
In this combined cycle power plant, steam that has cooled the gas turbine high-temperature portion 46 is recovered to the downstream side of the temperature reducer 34 of the steam turbine plant 3 by the cooling steam recovery system 72, and the exhaust steam of the steam turbine is recovered by the exhaust heat recovery boiler 1. And reheated together.
[0071]
In this combined cycle power plant, the steam after cooling of the gas turbine 8 is recovered to the downstream side of the temperature reducer 34 by the cooling steam recovery system 72, and this recovered steam is reheated by the exhaust heat recovery boiler 1. The temperature (medium pressure turbine inlet steam temperature) can be set to a desired temperature. In addition, since the gas turbine cooling steam is recovered downstream of the temperature reducer 34 of the reheat steam system 32 of the steam turbine plant 3, only an increase in pressure loss for the reheater 11 installed downstream of the temperature reducer 34 is achieved. Thus, it becomes possible to reheat the gas turbine cooling steam.
[0072]
FIG. 5 is a system diagram schematically showing a fifth embodiment of the combined cycle power plant according to the present invention.
[0073]
The combined cycle power plant shown in this embodiment is basically different from that shown in the first embodiment in the cooling steam recovery system 73 of the gas turbine 8, and the other configurations are substantially the same without being different. Therefore, the description about the overlapping part which attaches | subjects the same code | symbol is abbreviate | omitted.
[0074]
In this combined cycle power plant, the cooling steam supply system 48 of the cooling steam system 47 is the same as that shown in the first embodiment, but the cooling steam recovery system 73 is provided with a temperature reducer 74 on the way to reheat. It is connected to the low temperature reheat steam pipe 33 of the steam system 32 at the junction C5. The cooling steam recovery system 73 is connected to the high temperature section 46 of the gas turbine 8, and the opposite side is connected to the low temperature reheat steam pipe 33 of the reheat steam system 32 at a junction C 5 downstream of the reheat steam flow rate adjustment valve 37. Then, after the temperature of the steam after cooling the gas turbine high-temperature portion 46 is controlled by the temperature reducer 74, the steam is recovered by the reheat steam system 32.
[0075]
In the combined cycle power plant shown in FIG. 5, the cooling steam recovery system 73 is provided with a temperature reducer 74, and the temperature of the steam after cooling the gas turbine is controlled by the temperature reducer 74 to reheat the steam system 32. The recovered steam is combined with the steam turbine exhaust steam, and then reheated by the reheaters 12 and 11 of the exhaust heat recovery boiler 1 and supplied to the intermediate pressure turbine 38 at a desired reheat steam temperature. I have to. In this case, a temperature reducer 74 is provided in the cooling steam recovery system 73, and it becomes possible to control the recovery temperature of the gas turbine cooling steam with this temperature reducer 74, and a temperature mismatch at the junction C5 with the steam turbine exhaust steam is prevented. It becomes possible to suppress.
[0076]
FIG. 6 is a system diagram schematically showing a sixth embodiment of the combined cycle power plant according to the present invention.
[0077]
The combined cycle power plant shown in this embodiment is basically different from that shown in the first embodiment in the cooling steam recovery system 75 of the gas turbine 8, and the other components are the same. A description of the overlapping parts will be omitted.
[0078]
This combined cycle power plant is the same as that shown in the first embodiment in the cooling steam supply system 48 of the cooling steam system 47 and the cooling steam recovery system 75 is different. The cooling steam recovery system 75 of the cooling steam system 47 is provided with a temperature reducer 76, and is connected to the upstream side of the temperature reducer 34 provided in the reheat steam system 32 of the steam turbine plant 3 at a junction C 6. The cooling steam recovery system 75 is connected to the gas turbine high-temperature section 46 and guides the steam after cooling the gas turbine 8 to the temperature reducer 76, controls the steam temperature, and then returns to the reheat steam system 32 of the steam turbine plant 3. It collects between the heater 12 and the temperature reducer 34.
[0079]
The recovered steam recovered by the reheat steam system 32 is mixed with the steam turbine exhaust steam reheated by the first reheater 12 and heated again by the second reheater 11 of the exhaust heat recovery boiler 1. The reheat steam temperature is adjusted to a desired steam temperature and supplied to the intermediate pressure turbine 28.
[0080]
In this combined cycle power plant, the cooling steam supply system 75 includes a temperature reducer 76, controls the steam temperature after cooling the gas turbine, and then transfers the steam after cooling the gas turbine to the reheat steam system 32. 34 is recovered upstream to prevent a mismatch between the recovered steam temperature and the steam turbine exhaust temperature, while the recovered steam is merged with the low-temperature reheated steam reheated by the first reheater 12 to reduce the temperature of the temperature reducer 34. Then, after the entire steam temperature is controlled, it is reheated by the second reheater 11 of the exhaust heat recovery boiler 1 and supplied to the intermediate pressure turbine 28 at a desired reheat steam temperature.
[0081]
The cooling steam recovery system 75 mixes the gas turbine cooling steam upstream of the temperature reducer 34 of the reheat steam system 32 of the steam turbine exhaust steam, so that the reheat steam when the exhaust gas temperature of the gas turbine rises. Temperature control is easy. Further, the recovery temperature of the gas turbine cooling steam can be controlled by the temperature reducer 76, and the temperature mismatch at the junction C6 with the steam turbine exhaust steam can be suppressed.
[0082]
FIG. 7 is a system diagram schematically showing a seventh embodiment of the combined cycle power plant according to the present invention.
[0083]
In the combined cycle power plant shown in this embodiment, the cooling steam recovery system 77 of the gas turbine 8 is basically different from that shown in the first embodiment, and other configurations are not substantially different. Since they are the same, the same reference numerals are assigned and descriptions of overlapping parts are omitted.
[0084]
In this combined cycle power plant, the cooling steam supply system 48 of the cooling steam system 47 is the same as that shown in the first embodiment, and the cooling steam recovery system 77 is different. The cooling steam recovery system 77 of the cooling steam system 47 is provided with a temperature reducer 78, and is connected to the reheat steam system 32 of the steam turbine plant 3 at a junction C 7 downstream of the temperature reducer 34. The cooling steam recovery system 77 is connected to the gas turbine high temperature section 46 and guides the steam after cooling the gas turbine to the temperature reducer 78, controls the steam temperature, and then enters the reheat steam system 32 downstream of the temperature reducer 34. It is collected.
[0085]
The recovered steam recovered in the reheat steam system 32 is reheated together with the steam turbine exhaust steam in the second reheater 11 of the exhaust heat recovery boiler 1 to become a reheat steam at a desired temperature and is supplied to the intermediate pressure turbine 28. It comes to be supplied.
[0086]
In this combined cycle power plant, the cooling steam recovery system 77 is provided with a temperature reducer 78 and the temperature of the steam after cooling the gas turbine 8 is controlled by the temperature reducer 78, and then the steam turbine exhaust steam and the temperature reducer 34 downstream side. Are combined and recovered, reheated by the second reheater 11 of the exhaust heat recovery boiler 1, converted to reheat steam at a desired temperature, from a high temperature reheat steam pipe 35 through a reheat combination valve 36, and an intermediate pressure turbine. Can be supplied to.
[0087]
The steam recovery temperature after cooling the gas turbine can be controlled by the temperature reducer 78, and temperature mismatch at the junction with the steam turbine exhaust steam can be suppressed. In addition, since the gas turbine cooling steam is mixed downstream of the desuperheater in the steam turbine exhaust steam reheat system, the gas turbine cooling steam can be generated only by increasing the pressure loss of the reheater installed downstream of the desuperheater. It can be reheated.
[0088]
FIG. 8 is a system diagram schematically showing an eighth embodiment of the combined cycle power plant according to the present invention.
[0089]
The combined cycle power plant shown in this embodiment is fundamentally different from that shown in the first embodiment in the cooling steam recovery system 80 of the gas turbine 8, and the other configurations are the same and substantially different. Therefore, the same reference numerals are given and description of overlapping parts is omitted.
[0090]
In this combined cycle power plant, the cooling steam supply system 48 of the cooling steam system 47 is the same as that shown in the first embodiment, and the cooling steam recovery system 80 is different. The cooling steam recovery system 80 is provided with a gas turbine cooling steam reheater 81. The reheater 81 is installed in the exhaust heat recovery boiler 1, and is disposed, for example, between the first reheater 12 and the first high-pressure heater 13.
[0091]
One of the cooling steam recovery systems 80 of the cooling steam system 47 is connected to the outlet side of the gas turbine high temperature section 46, and a gas turbine cooling steam reheater 81 is provided on the way, and the other is the reheat steam system 32 of the steam turbine plant 3. Are connected at a confluence C8 upstream of the desuperheater 34.
[0092]
In this combined cycle power plant, after the gas turbine high temperature section 46 is cooled, the cooled steam is guided to the gas turbine cooling steam reheater 81 of the cooling steam recovery system 80 to be reheated, and reduced after this reheating. The low-temperature reheat steam is merged at the outlet 34 of the warmer 34 and is collected by the reheat steam system 32. The recovered steam combined with the low-temperature reheat steam is temperature-controlled by the temperature reducer 34 and then reheated by the second reheater 11 in the exhaust heat recovery boiler 1 to become reheat steam at a desired temperature. The high-temperature reheat steam pipe 35 is supplied to the intermediate pressure turbine 28 via the reheat combination valve 36.
[0093]
In this combined cycle power plant, the gas turbine cooling steam reheater 81 is provided in the cooling steam recovery system 80 of the cooling steam system 47, and the steam after cooling the gas turbine 8 is transferred by the reheater 81 in the exhaust heat recovery boiler 1. When reheated or the reheated recovered steam temperature becomes too high, after reheating with the reheater 81, the temperature is controlled with a temperature reducer (not shown) to reheat the steam turbine exhaust steam. It becomes possible to suppress the temperature mismatch at the junction C8 with the steam system 32. The temperature reducer is installed on the downstream side of the cooling steam reheater 81 of the cooling steam recovery system 80 as necessary. In addition, since the gas turbine cooling steam is mixed upstream of the temperature reducer 34 of the steam turbine exhaust steam reheat steam system 32, the temperature control of the reheat steam when the exhaust gas temperature of the gas turbine rises is easy.
[0094]
FIG. 9 is a system diagram schematically showing a ninth embodiment of the combined cycle power plant according to the present invention.
[0095]
The combined cycle power plant shown in this embodiment is basically different from the one shown in the first embodiment in the cooling steam recovery system 83 of the gas turbine 8, and the other components are the same. A description of the overlapping parts will be omitted.
[0096]
This combined cycle power plant has the same cooling steam supply system 48 as the cooling steam system 47 and the cooling steam recovery system 83 different from that shown in the first embodiment. In the cooling steam recovery system 83, a gas turbine cooling steam reheater 84 and a temperature reducer 85 are provided in series connection. One of the cooling steam recovery systems 83 is connected to the outlet side of the high temperature section 46 of the gas turbine 8, and the other is connected to the reheat steam system 32 of the steam turbine plant 3 on the downstream side of the temperature reducer 34.
[0097]
Then, the steam after cooling the gas turbine high temperature section 46 is reheated by the reheater 84 by the cooling steam recovery system 83 of the gas turbine 8, and the temperature is controlled by the temperature reducer 85 to reduce the temperature of the reheat steam system 32. 34 Combined with low-temperature reheated steam at the downstream side (exit part), recovered, and reheated by the second reheater 11 in the exhaust heat recovery boiler 1, the reheated steam temperature is set to a desired value. It can be temperature.
[0098]
By providing the cooling steam recovery system 83 with the gas turbine cooling steam reheater 84 and the temperature reducer 85, the recovered steam temperature of the gas turbine cooling steam is reheated by the reheater 84, or the recovered steam temperature When the fluctuation range is large, the temperature mismatch at the junction C9 with the reheat steam system 32 of the steam turbine plant 3 can be suppressed by controlling the temperature with the reheater 84 and the temperature reducer 85. . Further, the cooling steam recovery system 83 is connected to the downstream side of the temperature reducer 34 of the reheat steam system 32 of the steam turbine plant 3, and the steam after cooling the gas turbine is converted to low-temperature reheated steam downstream of the temperature reducer 34. Since mixing is performed, it becomes possible to reheat the gas turbine cooling steam only by increasing the pressure loss of the reheater 11 installed downstream of the temperature reducer 34.
[0099]
In the combined cycle power plant shown in each embodiment, the gas turbine plant and the steam turbine plant are uniaxial examples having a common shaft, but the gas turbine plant and the steam turbine plant each have a generator. The present invention may be applied to a provided multi-shaft combined cycle power plant.
[0100]
In addition, an example was shown in which multiple heaters, reheaters, and economizers were installed in the exhaust heat recovery boiler, but the number of heaters, reheaters, and economizers installed is a combined cycle power plant. Various modifications are conceivable depending on the power generation capacity, etc., and it may be one or more.
[0101]
【The invention's effect】
As described above, in the combined cycle power plant according to the present invention, the exhaust steam (a part) of the steam turbine is guided to the gas turbine high temperature section by the cooling steam supply system, and the gas turbine is effectively and efficiently cooled by steam cooling. While cooling well, the steam after cooling the gas turbine is reheated in the exhaust heat recovery boiler and recovered in the reheat steam system of the steam turbine plant, so it is desirable regardless of the recovery temperature of the gas turbine cooling steam The reheat steam temperature can be adjusted and supplied to the intermediate pressure turbine of the steam turbine, and turbine output control can be facilitated.
[Brief description of the drawings]
FIG. 1 is a schematic system diagram at the time of normal plant operation showing a first embodiment of a combined cycle power plant according to the present invention.
FIG. 2 is a schematic system diagram at the time of normal plant operation showing a second embodiment of the combined cycle power plant according to the present invention.
FIG. 3 is a schematic system diagram at the time of normal plant operation showing a third embodiment of a combined cycle power plant according to the present invention.
FIG. 4 is a schematic system diagram at the time of normal plant operation showing a fourth embodiment of a combined cycle power plant according to the present invention.
FIG. 5 is a schematic system diagram at the time of normal plant operation showing a fifth embodiment of the combined cycle power plant according to the present invention.
FIG. 6 is a schematic system diagram at the time of normal plant operation showing a sixth embodiment of a combined cycle power plant according to the present invention.
FIG. 7 is a schematic system diagram at the time of normal plant operation showing a seventh embodiment of a combined cycle power plant according to the present invention.
FIG. 8 is a schematic system diagram at the time of normal plant operation showing an eighth embodiment of a combined cycle power plant according to the present invention.
FIG. 9 is a schematic system diagram at the time of normal plant operation showing a ninth embodiment of a combined cycle power plant according to the present invention.
[Explanation of symbols]
1 Waste heat recovery boiler
2 Gas turbine plant
3 Steam turbine plant
4 Generator
5 Rotating shaft
6 Air compressor
7 Combustor
8 Gas turbine
9 Casing
10 Second high pressure superheater
11 Second reheater
12 First reheater
13 First high pressure superheater
14 High pressure evaporator
15 Medium pressure superheater
16 Third high pressure economizer
17 Low pressure superheater
18 Medium pressure evaporator
19 Second medium pressure economizer
20 Second high pressure economizer
21 Low pressure evaporator
22 First high pressure economizer
23 First medium pressure economizer
24 High pressure drum
25 Medium pressure drum
26 Low pressure drum
27 High-pressure turbine (steam turbine)
28 Medium-pressure turbine (steam turbine)
29 Low-pressure turbine (steam turbine)
30 High pressure control valve
31 Main steam system (superheated steam system)
32 Reheat steam system
33 Low temperature reheat steam pipe
34 Reducer
35 High-temperature reheat steam pipe
36 Reheat combination valve
37 Reheat main steam flow control valve (Gas turbine cooling steam flow control valve)
38 Low pressure steam supply system
39 Low pressure steam combination valve
40 condenser
41 Condensate water supply system
43 Condensate pump
44 Water supply pump
46 Gas turbine hot section
47 Cooling steam system
48 Cooling steam supply system
49 Cooling steam recovery system
50 Cooling steam bypass system
51 Bypass steam valve
53 Check valve
54 Medium pressure steam system
55 Boiler recovery system
56 Cooling steam reheater (reheating means)
57 Turbine recovery system
60 High-pressure turbine bypass system
61 Medium-pressure turbine bypass system
62 Low pressure turbine bypass system
63 High-pressure turbine bypass valve
64 Medium pressure turbine bypass valve
65 Low pressure turbine bypass valve
66 Reducer
70, 71, 72 Cooling steam recovery system
73, 75, 77, 80 Cooling steam recovery system
74, 76, 78, 85 Reducer
81,84 Cooling steam reheater

Claims

A gas turbine plant equipped with a gas turbine, an exhaust heat recovery boiler that generates steam using exhaust gas from the gas turbine, and a steam turbine plant that uses steam generated in the exhaust heat recovery boiler as a drive source of the steam turbine And a combined cycle power plant having a cooling steam supply system connected to the inlet side of the high-temperature portion of the gas turbine and supplying exhaust steam from the steam turbine as cooling steam,
Connected to the outlet side of the gas turbine high temperature section, comprising a cooling steam recovery system for recovering steam after cooling the gas turbine,
This cooling steam recovery system
A boiler recovery system for guiding steam after cooling to the gas turbine to an exhaust heat recovery boiler;
A reheater that reheats the steam after cooling with the exhaust heat recovery boiler; and a turbine recovery system that recovers the reheated steam to the steam turbine, the cooling steam recovery system downstream of the reheater A combined cycle power plant characterized in that a temperature reducer is provided on the side and the reheat steam temperature is controlled by this temperature reducer .

A gas turbine plant equipped with a gas turbine, an exhaust heat recovery boiler that generates steam using exhaust gas from the gas turbine, and a steam turbine plant that uses steam generated in the exhaust heat recovery boiler as a drive source of the steam turbine And a combined cycle power plant having a cooling steam supply system connected to the inlet side of the high-temperature portion of the gas turbine and supplying exhaust steam from the steam turbine as cooling steam,
A cooling steam recovery system connected to the outlet side of the high-temperature section of the gas turbine,
This cooling steam recovery system is a combined cycle power plant characterized in that the steam after cooling the high temperature part of the gas turbine is recovered on the way to the low temperature side of the reheat steam system of the steam turbine plant.

A gas turbine plant equipped with a gas turbine, an exhaust heat recovery boiler that generates steam using exhaust gas from the gas turbine, and a steam turbine plant that uses steam generated in the exhaust heat recovery boiler as a drive source of the steam turbine And in the combined cycle power plant provided with a cooling steam supply system connected to the inlet side of the gas turbine high temperature section and supplying exhaust steam from the steam turbine as cooling steam,
A cooling steam recovery system connected to the outlet side of the gas turbine high temperature section,
In this cooling steam recovery system, the steam after cooling the high-temperature part of the gas turbine is recovered on the way to the upstream side of the desuperheater installed in the reheat steam system of the steam turbine plant. Cycle power plant.

A gas turbine plant equipped with a gas turbine, an exhaust heat recovery boiler that generates steam using exhaust gas from the gas turbine, and a steam turbine plant that uses steam generated in the exhaust heat recovery boiler as a drive source of the steam turbine And a combined cycle power plant having a cooling steam supply system connected to the inlet side of the high-temperature portion of the gas turbine and supplying exhaust steam from the steam turbine as cooling steam,
A cooling steam recovery system connected to the outlet side of the gas turbine high temperature section,
In this cooling steam recovery system, the steam after cooling the high-temperature part of the gas turbine is recovered on the way to the downstream side of the desuperheater installed in the reheat steam system of the steam turbine plant. Cycle power plant.

A gas turbine plant equipped with a gas turbine, an exhaust heat recovery boiler that generates steam using exhaust gas from the gas turbine, and a steam turbine plant that uses steam generated in the exhaust heat recovery boiler as a drive source of the steam turbine And a combined cycle power plant having a cooling steam supply system that is connected to the inlet of the gas turbine high temperature section and supplies exhaust steam from the steam turbine as cooling steam.
A cooling steam recovery system connected to the outlet side of the gas turbine high temperature section,
This cooling steam recovery system includes a temperature reducer that controls the temperature of the steam after cooling the gas turbine in the middle, and is connected to the low temperature side of the reheat steam system of the steam turbine plant. A combined cycle power plant characterized by recovering steam after cooling a gas turbine.

A gas turbine plant including a gas turbine, an exhaust heat recovery boiler that generates steam using exhaust gas from the gas turbine, and a steam turbine plant that uses steam generated in the exhaust heat recovery boiler as a drive source of the steam turbine; In the combined cycle power plant having a cooling steam supply system connected to the inlet side of the gas turbine high temperature section and supplying exhaust steam from the steam turbine as cooling steam,
A cooling steam recovery system connected to the outlet side of the gas turbine high temperature section,
The cooling steam recovery system includes a desuperheater that controls the temperature of the steam after cooling the gas turbine in the middle, and is connected to the upstream side of the desuperheater of the reheat steam system of the steam turbine plant, and upstream of the desuperheater. A combined cycle power plant characterized in that the steam after cooling the gas turbine is recovered on the side.

A gas turbine plant equipped with a gas turbine, an exhaust heat recovery boiler that generates steam using exhaust gas from the gas turbine, and a steam turbine plant that uses steam generated in the exhaust heat recovery boiler as a drive source of the steam turbine And a combined cycle plant that is connected to the inlet side of the gas turbine high temperature section and includes a cooling steam supply system that supplies exhaust steam from the steam turbine as cooling steam,
A cooling steam recovery system connected to the outlet side of the high temperature section of the gas turbine,
The cooling steam recovery system includes a temperature reducer that controls the temperature of the steam after cooling the gas turbine in the middle, and is connected to the downstream side of the temperature reducer of the reheat steam system of the steam turbine plant, and downstream of the temperature reducer. A combined cycle power plant characterized in that the steam after cooling the gas turbine is recovered on the side.

A gas turbine plant equipped with a gas turbine, an exhaust heat recovery boiler that generates steam using exhaust gas from the gas turbine, and a steam turbine plant that uses steam generated in the exhaust heat recovery boiler as a drive source of the steam turbine And a combined cycle power plant having a cooling steam supply system connected to the inlet side of the high-temperature portion of the gas turbine and supplying exhaust steam from the steam turbine as cooling steam,
A cooling steam recovery system connected to the outlet side of the gas turbine high temperature section,
This cooling steam recovery system connects a cooling steam reheater that reheats the steam after cooling the gas turbine in the exhaust heat recovery boiler to the upstream side of the desuperheater of the reheat steam system of the steam turbine plant provided in the middle A combined cycle power plant characterized in that the steam after cooling the gas turbine is recovered upstream of the temperature reducer.

A gas turbine plant equipped with a gas turbine, an exhaust heat recovery boiler that generates steam using exhaust gas from the gas turbine, and a steam turbine plant that uses steam generated in the exhaust heat recovery boiler as a drive source of the steam turbine And a combined cycle power plant having a cooling steam supply system connected to the inlet side of the high-temperature portion of the gas turbine and supplying exhaust steam from the steam turbine as cooling steam,
A cooling steam recovery system connected to the outlet side of the gas turbine high temperature section,
In this cooling steam recovery system, a cooling steam reheater that reheats the steam after cooling in the exhaust heat recovery boiler is connected to the downstream side of the desuperheater of the reheat steam system of the steam turbine plant that is provided on the way. A combined cycle power plant characterized in that the steam after cooling the gas turbine is recovered downstream of the temperature reducer.

The cooling steam recovery system is provided with a temperature reducer on the downstream side of the cooling steam reheater, and the temperature of the reheated steam after cooling the gas turbine is controlled by the temperature reducer to be recovered by the reheat steam system of the steam turbine plant. The combined cycle power plant according to claim 8 or 9 .