JP3845905B2 - Outlet feed water temperature control device for gas high pressure feed water heater in exhaust recombustion combined cycle plant - Google Patents

Outlet feed water temperature control device for gas high pressure feed water heater in exhaust recombustion combined cycle plant Download PDF

Info

Publication number
JP3845905B2
JP3845905B2 JP19760796A JP19760796A JP3845905B2 JP 3845905 B2 JP3845905 B2 JP 3845905B2 JP 19760796 A JP19760796 A JP 19760796A JP 19760796 A JP19760796 A JP 19760796A JP 3845905 B2 JP3845905 B2 JP 3845905B2
Authority
JP
Japan
Prior art keywords
feed water
flow rate
water heater
pressure feed
output
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP19760796A
Other languages
Japanese (ja)
Other versions
JPH1038201A (en
Inventor
寿範 温見
Original Assignee
石川島播磨重工業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 石川島播磨重工業株式会社 filed Critical 石川島播磨重工業株式会社
Priority to JP19760796A priority Critical patent/JP3845905B2/en
Publication of JPH1038201A publication Critical patent/JPH1038201A/en
Application granted granted Critical
Publication of JP3845905B2 publication Critical patent/JP3845905B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E20/00—Combustion technologies with mitigation potential
    • Y02E20/16—Combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT]

Description

【０００１】
【発明の属する技術分野】
本発明は、排気再燃型コンバインドサイクルプラントにおけるガス高圧給水加熱器の出口給水温度制御装置に関するものである。
【０００２】
【従来の技術】
一般に、ボイラによる発電プラントは、図５に示されるように、ボイラ本体１において燃料の燃焼を行うと共に、給水ポンプ２によって圧送される給水を高圧給水加熱器３を介してボイラ本体１へ導き、加熱して蒸気を発生させ、該蒸気を蒸気タービン４へ供給して蒸気タービン発電機５を駆動し発電を行い、該蒸気タービン発電機５を駆動した後の蒸気の一部を前記高圧給水加熱器３へ導き、前記ボイラ本体１へ供給される給水を加熱するようになっているが、近年、図５に示されるような既設のプラントを改造し、図６に示される如く、熱効率の向上を図った排気再燃型コンバインドサイクルプラントとする試みが行われている。
【０００３】
前記排気再燃型コンバインドサイクルプラントは、燃焼器６から送給される燃焼ガスにより駆動され且つガスタービン発電機７と圧縮機８を駆動するガスタービン９と、該ガスタービン９からの高温の排ガスを所要温度まで温度降下させボイラ本体１へ導く風道蒸発器１０と、前記高圧給水加熱器３と並列に設けられ且つボイラ本体１から排出される排ガスによって給水の一部を加熱するガス高圧給水加熱器１１とを追加装備してなる構成を有している。
【０００４】
図６に示される排気再燃型コンバインドサイクルプラントにおいては、前記燃焼器６に噴射された燃料が圧縮機８から送給される圧縮空気と混合して燃焼し、該燃焼器６からの燃焼ガスがガスタービン９へ供給されて、前記圧縮機８とガスタービン発電機７が駆動され発電が行われ、該ガスタービン発電機７を駆動した後のガスタービン９の排ガスが風道蒸発器１０において所要温度まで温度降下されてボイラ本体１へ導かれ、該ボイラ本体１において燃料の燃焼用ガスとして燃焼に供され、更に、前記ボイラ本体１から排出される排ガスがガス高圧給水加熱器１１へ導入され、該ガス高圧給水加熱器１１において前記排ガスにより給水の一部が加熱され、高圧給水加熱器３において蒸気タービン４からの蒸気によって加熱された給水と合流されて前記ボイラ本体１へ導かれ、蒸気化されるようになっている。
【０００５】
【発明が解決しようとする課題】
前述の如き排気再燃型コンバインドサイクルプラントにおいては、機器構成の簡略化並びに経済性の面等から、高圧給水加熱器３の一個の流量調整弁１２の開度を適宜調整することにより、高圧給水加熱器３とガス高圧給水加熱器１１へ分配される給水の流量を調整し、ガス高圧給水加熱器１１の出口給水温度を制御することが望まれているが、前記ガス高圧給水加熱器１１の出口給水温度を制御するための具体的な手段は確立されていないのが現状であった。
【０００６】
本発明は、斯かる実情に鑑み、高圧給水加熱器３の流量調整弁１２の開度調整により、該高圧給水加熱器３とガス高圧給水加熱器１１へ分配される給水の流量を調整し、ガス高圧給水加熱器１１の出口給水温度を制御し得る排気再燃型コンバインドサイクルプラントにおけるガス高圧給水加熱器の出口給水温度制御装置を提供しようとするものである。
【０００７】
【課題を解決するための手段】
【０００８】
本発明は、ガスタービン９の排ガスをボイラ本体１において燃料の燃焼用ガスとして使用すると共に、高圧給水加熱器３とガス高圧給水加熱器１１とによりボイラ本体１への給水を加熱するようにした排気再燃型コンバインドサイクルプラントにおけるガス高圧給水加熱器の出口給水温度制御装置であって、
ボイラ負荷指令１９に基づきガス高圧給水加熱器１１の出口給水温度設定値２５を出力する関数発生器２４と、
ボイラ負荷指令１９に基づき高圧給水加熱器３の給水流量設定値２７を出力する関数発生器２６と、
前記関数発生器２４から出力されるガス高圧給水加熱器１１の出口給水温度設定値２５と、ガス高圧給水加熱器１１の出口給水温度１８との差を求め、出口給水温度偏差２９を出力する減算器２８と、
高圧給水加熱器３の給水最低流量設定値３１と、前記関数発生器２６から出力される高圧給水加熱器３の給水流量設定値２７との差を求め、流量設定値偏差３３を出力する減算器３２と、
前記減算器２８から出力されるガス高圧給水加熱器１１の出口給水温度偏差２９を比例積分処理して高圧給水加熱器３の給水流量補正値を求め、該高圧給水加熱器３の給水流量補正値が前記減算器３２から出力される流量設定値偏差３３より大きい場合には、前記高圧給水加熱器３の給水流量補正値をそのまま補正指令３５として出力する一方、前記高圧給水加熱器３の給水流量補正値が前記減算器３２から出力される流量設定値偏差３３以下の場合には、該流量設定値偏差３３を補正指令３５として出力する低信号制限器付比例積分調節器３４と、
前記関数発生器２６から出力される高圧給水加熱器３の給水流量設定値２７に対し前記低信号制限器付比例積分調節器３４から出力される補正指令３５を加え、高圧給水加熱器３の給水流量補正設定値３７を出力する加算器３６と、
前記高圧給水加熱器３を流れる給水流量２３と、前記加算器３６から出力される高圧給水加熱器３の給水流量補正設定値３７との差を求め、高圧給水加熱器３の給水流量偏差３９を出力する減算器３８と、
該減算器３８から出力される高圧給水加熱器３の給水流量偏差３９を比例積分処理して前記高圧給水加熱器３の流量調整弁１２へ開度指令２１を出力する比例積分調節器４０と
を備えたことを特徴とする排気再燃型コンバインドサイクルプラントにおけるガス高圧給水加熱器の出口給水温度制御装置にかかるものである。
【０００９】
上記手段によれば、以下のような作用が得られる。
【００１０】
【００１１】
本発明の排気再燃型コンバインドサイクルプラントにおけるガス高圧給水加熱器の出口給水温度制御装置においては、ボイラ負荷指令１９に基づき関数発生器２４においてガス高圧給水加熱器１１の出口給水温度設定値２５が求められて減算器２８へ出力され、ボイラ負荷指令１９に基づき関数発生器２６において高圧給水加熱器３の給水流量設定値２７が求められて減算器３２と加算器３６へ出力され、減算器２８において前記関数発生器２４から出力されるガス高圧給水加熱器１１の出口給水温度設定値２５と、前記温度検出器１７で検出されたガス高圧給水加熱器１１の出口給水温度１８との差が求められ、出口給水温度偏差２９が低信号制限器付比例積分調節器３４へ出力され、減算器３２において前記高圧給水加熱器３の給水最低流量設定値３１と、前記関数発生器２６から出力される高圧給水加熱器３の給水流量設定値２７との差が求められ、流量設定値偏差３３が低信号制限器付比例積分調節器３４へ出力され、該低信号制限器付比例積分調節器３４において前記減算器２８から出力されるガス高圧給水加熱器１１の出口給水温度偏差２９が比例積分処理されて高圧給水加熱器３の給水流量補正値が求められ、該高圧給水加熱器３の給水流量補正値が前記減算器３２から出力される流量設定値偏差３３より大きい場合には、前記高圧給水加熱器３の給水流量補正値がそのまま補正指令３５として加算器３６へ出力される一方、前記高圧給水加熱器３の給水流量補正値が前記減算器３２から出力される流量設定値偏差３３以下の場合には、該流量設定値偏差３３が補正指令３５として加算器３６へ出力され、該加算器３６において前記関数発生器２６から出力される高圧給水加熱器３の給水流量設定値２７に対し前記低信号制限器付比例積分調節器３４から出力される補正指令３５が加えられ、高圧給水加熱器３の給水流量補正設定値３７が減算器３８へ出力され、該減算器３８において前記減算器２２から出力される高圧給水加熱器３を流れる給水流量２３と、前記加算器３６から出力される高圧給水加熱器３の給水流量補正設定値３７との差が求められ、高圧給水加熱器３の給水流量偏差３９が比例積分調節器４０へ出力され、該比例積分調節器４０において前記減算器３８から出力される高圧給水加熱器３の給水流量偏差３９が比例積分処理されて流量調整弁１２へ開度指令２１が出力され、該開度指令２１に応じて流量調整弁１２の開度が調節され、高圧給水加熱器３とガス高圧給水加熱器１１へ分配される給水の流量が調整され、ガス高圧給水加熱器１１の出口給水温度が出口給水温度設定値２５となるように制御される。
【００１２】
【発明の実施の形態】
以下、本発明の実施の形態を図示例と共に説明する。
【００１３】
図１〜図４は本発明を実施する形態の一例であって、図中、図６と同一の符号を付した部分は同一物を表わしており、１３は給水ポンプ２の吐出流量１４を検出する流量検出器、１５はガス高圧給水加熱器１１を流れる給水流量１６を検出する流量検出器、１７はガス高圧給水加熱器１１の出口給水温度１８を検出する温度検出器、２０は前記流量検出器１３で検出された給水ポンプ２の吐出流量１４と、前記流量検出器１５で検出されたガス高圧給水加熱器１１を流れる給水流量１６と、前記温度検出器１７で検出されたガス高圧給水加熱器１１の出口給水温度１８と、ボイラ負荷指令（ＭＷＤ）１９とに基づき、高圧給水加熱器３の流量調整弁１２に対して開度指令２１を出力する制御器である。
【００１４】
前記制御器２０は、図２に示す如く、前記流量検出器１３で検出された給水ポンプ２の吐出流量１４と、前記流量検出器１５で検出されたガス高圧給水加熱器１１を流れる給水流量１６との差を求め、高圧給水加熱器３を流れる給水流量２３を出力する減算器２２と、
ボイラ負荷指令１９に基づきガス高圧給水加熱器１１の出口給水温度設定値２５を求めて出力する関数発生器２４と、
ボイラ負荷指令１９に基づき高圧給水加熱器３の給水流量設定値２７を求めて出力する関数発生器２６と、
前記関数発生器２４から出力されるガス高圧給水加熱器１１の出口給水温度設定値２５と、前記温度検出器１７で検出されたガス高圧給水加熱器１１の出口給水温度１８との差を求め、出口給水温度偏差２９を出力する減算器２８と、
蒸気タービン４から高圧給水加熱器３への蒸気抽気前には０［ｔｏｎ／ｈ］を高圧給水加熱器３の給水最低流量設定値３１として出力する（ａ側に切り換えられる）一方、蒸気タービン４から高圧給水加熱器３への蒸気抽気後にはα［ｔｏｎ／ｈ］を高圧給水加熱器３の給水最低流量設定値３１として出力する（ｂ側に切り換えられる）切換器３０と、
該切換器３０から出力される高圧給水加熱器３の給水最低流量設定値３１と、前記関数発生器２６から出力される高圧給水加熱器３の給水流量設定値２７との差を求め、流量設定値偏差３３を出力する減算器３２と、
前記減算器２８から出力されるガス高圧給水加熱器１１の出口給水温度偏差２９を比例積分処理して高圧給水加熱器３の給水流量補正値を求め、該高圧給水加熱器３の給水流量補正値が前記減算器３２から出力される流量設定値偏差３３より大きい場合には、前記高圧給水加熱器３の給水流量補正値をそのまま補正指令３５として出力する一方、前記高圧給水加熱器３の給水流量補正値が前記減算器３２から出力される流量設定値偏差３３以下の場合には、該流量設定値偏差３３を補正指令３５として出力する低信号制限器付比例積分調節器３４と、
前記関数発生器２６から出力される高圧給水加熱器３の給水流量設定値２７に対し前記低信号制限器付比例積分調節器３４から出力される補正指令３５を加え、高圧給水加熱器３の給水流量補正設定値３７を出力する加算器３６と、
前記減算器２２から出力される高圧給水加熱器３を流れる給水流量２３と、前記加算器３６から出力される高圧給水加熱器３の給水流量補正設定値３７との差を求め、高圧給水加熱器３の給水流量偏差３９を出力する減算器３８と、
該減算器３８から出力される高圧給水加熱器３の給水流量偏差３９を比例積分処理して前記流量調整弁１２へ開度指令２１を出力する比例積分調節器４０と
を備えてなる構成を有している。
【００１５】
尚、前記関数発生器２４には、図３に示されるような関数Ｆ1（ｘ）が入力されており、該関数Ｆ1（ｘ）は、ボイラ負荷指令１９の増減に対し略比例させてガス高圧給水加熱器１１の出口給水温度設定値２５を増減させることを表わしている。
【００１６】
又、前記関数発生器２６には、図４に示されるような関数Ｆ2（ｘ）が入力されており、該関数Ｆ2（ｘ）は、ボイラ負荷指令１９の増減に対し略比例させて高圧給水加熱器３の給水流量設定値２７を増減させることを表わしている。
【００１７】
次に、上記図示例の作動を説明する。
【００１８】
運転時には、流量検出器１３で検出された給水ポンプ２の吐出流量１４と、流量検出器１５で検出されたガス高圧給水加熱器１１を流れる給水流量１６との差が制御器２０の減算器２２において求められ、高圧給水加熱器３を流れる給水流量２３が減算器３８へ出力され、ボイラ負荷指令１９に基づき関数発生器２４においてガス高圧給水加熱器１１の出口給水温度設定値２５が求められて減算器２８へ出力され、ボイラ負荷指令１９に基づき関数発生器２６において高圧給水加熱器３の給水流量設定値２７が求められて減算器３２と加算器３６へ出力され、減算器２８において前記関数発生器２４から出力されるガス高圧給水加熱器１１の出口給水温度設定値２５と、前記温度検出器１７で検出されたガス高圧給水加熱器１１の出口給水温度１８との差が求められ、出口給水温度偏差２９が低信号制限器付比例積分調節器３４へ出力される。
【００１９】
ここで、蒸気タービン４から高圧給水加熱器３への蒸気抽気前には、切換器３０の入力がａ側に切り換えられ、該切換器３０から０［ｔｏｎ／ｈ］が高圧給水加熱器３の給水最低流量設定値３１として減算器３２へ出力され、該減算器３２において前記切換器３０から出力される高圧給水加熱器３の給水最低流量設定値３１と、前記関数発生器２６から出力される高圧給水加熱器３の給水流量設定値２７との差が求められ、流量設定値偏差３３が低信号制限器付比例積分調節器３４へ出力され、該低信号制限器付比例積分調節器３４において前記減算器２８から出力されるガス高圧給水加熱器１１の出口給水温度偏差２９が比例積分処理されて高圧給水加熱器３の給水流量補正値が求められ、該高圧給水加熱器３の給水流量補正値が前記減算器３２から出力される流量設定値偏差３３より大きい場合には、前記高圧給水加熱器３の給水流量補正値がそのまま補正指令３５として加算器３６へ出力される一方、前記高圧給水加熱器３の給水流量補正値が前記減算器３２から出力される流量設定値偏差３３以下の場合には、該流量設定値偏差３３が補正指令３５として加算器３６へ出力され、該加算器３６において前記関数発生器２６から出力される高圧給水加熱器３の給水流量設定値２７に対し前記低信号制限器付比例積分調節器３４から出力される補正指令３５が加えられ、高圧給水加熱器３の給水流量補正設定値３７が減算器３８へ出力され、該減算器３８において前記減算器２２から出力される高圧給水加熱器３を流れる給水流量２３と、前記加算器３６から出力される高圧給水加熱器３の給水流量補正設定値３７との差が求められ、高圧給水加熱器３の給水流量偏差３９が比例積分調節器４０へ出力され、該比例積分調節器４０において前記減算器３８から出力される高圧給水加熱器３の給水流量偏差３９が比例積分処理されて流量調整弁１２へ開度指令２１が出力され、該開度指令２１に応じて流量調整弁１２の開度が調節され、高圧給水加熱器３とガス高圧給水加熱器１１へ分配される給水の流量が調整され、ガス高圧給水加熱器１１の出口給水温度が出口給水温度設定値２５となるように制御される。
【００２０】
尚、前記ガス高圧給水加熱器１１の実際の出口給水温度１８が非常に高くなり、該ガス高圧給水加熱器１１へ流通させる給水の流量を大幅に増加させる必要が生じ、前記低信号制限器付比例積分調節器３４において減算器２８から出力されるガス高圧給水加熱器１１の出口給水温度偏差２９が比例積分処理されて求められる高圧給水加熱器３の給水流量補正値が、減算器３２から出力される流量設定値偏差３３以下となった場合には、該流量設定値偏差３３が補正指令３５として加算器３６へ出力され、該加算器３６において前記関数発生器２６から出力される高圧給水加熱器３の給水流量設定値２７に対し前記低信号制限器付比例積分調節器３４から出力される補正指令３５が加えられるため、結果的に０［ｔｏｎ／ｈ］が高圧給水加熱器３の給水流量補正設定値３７として減算器３８へ出力されることとなり、流量調整弁１２が全閉とされ、高圧給水加熱器３に対して給水が全く流通しない状態となるが、このときは蒸気タービン４から高圧給水加熱器３への蒸気抽気前であるため、高圧給水加熱器３が熱により損傷を受けたりする心配はない。
【００２１】
一方、蒸気タービン４から高圧給水加熱器３への蒸気抽気後には、切換器３０の入力がｂ側に切り換えられ、該切換器３０からα［ｔｏｎ／ｈ］が高圧給水加熱器３の給水最低流量設定値３１として減算器３２へ出力され、該減算器３２において前記切換器３０から出力される高圧給水加熱器３の給水最低流量設定値３１と、前記関数発生器２６から出力される高圧給水加熱器３の給水流量設定値２７との差が求められ、流量設定値偏差３３が低信号制限器付比例積分調節器３４へ出力され、該低信号制限器付比例積分調節器３４において前記減算器２８から出力されるガス高圧給水加熱器１１の出口給水温度偏差２９が比例積分処理されて高圧給水加熱器３の給水流量補正値が求められ、該高圧給水加熱器３の給水流量補正値が前記減算器３２から出力される流量設定値偏差３３より大きい場合には、前記高圧給水加熱器３の給水流量補正値がそのまま補正指令３５として加算器３６へ出力される一方、前記高圧給水加熱器３の給水流量補正値が前記減算器３２から出力される流量設定値偏差３３以下の場合には、該流量設定値偏差３３が補正指令３５として加算器３６へ出力され、該加算器３６において前記関数発生器２６から出力される高圧給水加熱器３の給水流量設定値２７に対し前記低信号制限器付比例積分調節器３４から出力される補正指令３５が加えられ、高圧給水加熱器３の給水流量補正設定値３７が減算器３８へ出力され、該減算器３８において前記減算器２２から出力される高圧給水加熱器３を流れる給水流量２３と、前記加算器３６から出力される高圧給水加熱器３の給水流量補正設定値３７との差が求められ、高圧給水加熱器３の給水流量偏差３９が比例積分調節器４０へ出力され、該比例積分調節器４０において前記減算器３８から出力される高圧給水加熱器３の給水流量偏差３９が比例積分処理されて流量調整弁１２へ開度指令２１が出力され、該開度指令２１に応じて流量調整弁１２の開度が調節され、高圧給水加熱器３とガス高圧給水加熱器１１へ分配される給水の流量が調整され、ガス高圧給水加熱器１１の出口給水温度が出口給水温度設定値２５となるように制御される。
【００２２】
尚、蒸気タービン４から高圧給水加熱器３への蒸気抽気後に、前記ガス高圧給水加熱器１１の実際の出口給水温度１８が非常に高くなり、該ガス高圧給水加熱器１１へ流通させる給水の流量を大幅に増加させる必要が生じ、前記低信号制限器付比例積分調節器３４において減算器２８から出力されるガス高圧給水加熱器１１の出口給水温度偏差２９が比例積分処理されて求められる高圧給水加熱器３の給水流量補正値が、減算器３２から出力される流量設定値偏差３３以下となった場合には、該流量設定値偏差３３が補正指令３５として加算器３６へ出力され、該加算器３６において前記関数発生器２６から出力される高圧給水加熱器３の給水流量設定値２７に対し前記低信号制限器付比例積分調節器３４から出力される補正指令３５が加えられるため、結果的にα［ｔｏｎ／ｈ］が高圧給水加熱器３の給水流量補正設定値３７として減算器３８へ出力されることとなり、流量調整弁１２が全閉とされず、高圧給水加熱器３に対してα［ｔｏｎ／ｈ］の給水が必ず流通する状態となり、高圧給水加熱器３の給水最低流量が確保され、高圧給水加熱器３が熱から保護される形となる。
【００２３】
こうして、高圧給水加熱器３の流量調整弁１２の開度調整により、該高圧給水加熱器３とガス高圧給水加熱器１１へ分配される給水の流量を調整し、ガス高圧給水加熱器１１の出口給水温度を制御し得、更に、高圧給水加熱器３の給水最低流量を確保して、高圧給水加熱器３を熱から保護し得る。
【００２４】
尚、本発明の排気再燃型コンバインドサイクルプラントにおけるガス高圧給水加熱器の出口給水温度制御装置は、上述の図示例にのみ限定されるものではなく、流量検出器で検出された給水ポンプの吐出流量と、流量検出器で検出されたガス高圧給水加熱器１１を流れる給水流量との差から、高圧給水加熱器３を流れる給水流量を求める代りに、高圧給水加熱器３を流れる給水流量を直接検出するようにしてもよいこと等、その他、本発明の要旨を逸脱しない範囲内において種々変更を加え得ることは勿論である。
【００２５】
【発明の効果】
以上、説明したように本発明の排気再燃型コンバインドサイクルプラントにおけるガス高圧給水加熱器の出口給水温度制御装置によれば、高圧給水加熱器３の流量調整弁１２の開度調整により、該高圧給水加熱器３とガス高圧給水加熱器１１へ分配される給水の流量を調整し、ガス高圧給水加熱器１１の出口給水温度を制御し得、更に、高圧給水加熱器３の給水最低流量を確保して、高圧給水加熱器３を熱から保護し得るという優れた効果を奏し得る。
【図面の簡単な説明】
【図１】 本発明を実施する形態の一例の全体概要構成図である。
【図２】 本発明を実施する形態の一例における制御器の詳細を示すブロック図である。
【図３】 図２に示す関数発生器２４に設定されている関数を表わす線図である。
【図４】 図２に示す関数発生器２６に設定されている関数を表わす線図である。
【図５】 従来の一般的なボイラによる発電プラントの一例の全体概要構成図である。
【図６】 近年提案されている排気再燃型コンバインドサイクルプラントの一例の全体概要構成図である。
【符号の説明】
１ ボイラ本体
３ 高圧給水加熱器
９ ガスタービン
１１ ガス高圧給水加熱器
１２ 流量調整弁
１６ 給水流量
１８ 出口給水温度
１９ ボイラ負荷指令
２０ 制御器
２１ 開度指令
２３ 給水流量
２４ 関数発生器
２５ 出口給水温度設定値
２６ 関数発生器
２７ 給水流量設定値
２８ 減算器
２９ 出口給水温度偏差
３１ 給水最低流量設定値
３２ 減算器
３３ 流量設定値偏差
３４ 低信号制限器付比例積分調節器
３５ 補正指令
３６ 加算器
３７ 給水流量補正設定値
３８ 減算器
３９ 給水流量偏差
４０ 比例積分調節器[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an outlet feed water temperature control device for a gas high-pressure feed water heater in an exhaust reburning type combined cycle plant.
[0002]
[Prior art]
In general, as shown in FIG. 5, a power plant using a boiler burns fuel in the boiler body 1 and guides feed water pumped by the feed water pump 2 to the boiler body 1 via the high-pressure feed water heater 3. Steam is generated by heating, the steam is supplied to the steam turbine 4 to drive the steam turbine generator 5 to generate power, and a part of the steam after driving the steam turbine generator 5 is heated by the high-pressure feed water However, in recent years, the existing plant as shown in FIG. 5 has been remodeled to improve the thermal efficiency as shown in FIG. 6. Attempts have been made to make an exhaust-fired combined cycle plant that achieves the above.
[0003]
The exhaust recombustion type combined cycle plant is driven by combustion gas fed from a combustor 6 and drives a gas turbine generator 7 and a compressor 8, and high-temperature exhaust gas from the gas turbine 9. Gas high-pressure feed water heating, which is provided in parallel with the high-pressure feed water heater 3 and the air passage evaporator 10 that lowers the temperature to the required temperature and leads to the boiler body 1 and heats part of the feed water by the exhaust gas discharged from the boiler body 1 And a device 11 is additionally provided.
[0004]
In the exhaust recombustion type combined cycle plant shown in FIG. 6, the fuel injected into the combustor 6 is mixed with the compressed air fed from the compressor 8 and burned, and the combustion gas from the combustor 6 is The gas turbine 9 is supplied to drive the compressor 8 and the gas turbine generator 7 to generate power, and the exhaust gas of the gas turbine 9 after the gas turbine generator 7 is driven is required in the wind path evaporator 10. The temperature is lowered to the temperature, led to the boiler body 1, used as combustion gas for fuel in the boiler body 1, and exhaust gas discharged from the boiler body 1 is further introduced into the gas high-pressure feed water heater 11. In the gas high pressure feed water heater 11, a part of the feed water is heated by the exhaust gas, and the high pressure feed water heater 3 joins with the feed water heated by the steam from the steam turbine 4. The guided to the boiler body 1, and is vaporized been.
[0005]
[Problems to be solved by the invention]
In the exhaust recombustion type combined cycle plant as described above, the high pressure feed water heating is performed by appropriately adjusting the opening of one flow rate adjusting valve 12 of the high pressure feed water heater 3 in view of simplification of the equipment configuration and economy. It is desired to adjust the flow rate of the feed water distributed to the gas vessel 3 and the gas high-pressure feed water heater 11 to control the outlet feed water temperature of the gas high-pressure feed water heater 11. The present condition is that the concrete means for controlling feed water temperature is not established.
[0006]
In view of such circumstances, the present invention adjusts the flow rate of feed water distributed to the high pressure feed water heater 3 and the gas high pressure feed water heater 11 by adjusting the opening of the flow rate regulating valve 12 of the high pressure feed water heater 3. An outlet water supply temperature control device for a gas high-pressure feed water heater in an exhaust reburning combined cycle plant capable of controlling the outlet feed water temperature of the gas high-pressure feed water heater 11 is provided.
[0007]
[Means for Solving the Problems]
[0008]
The present invention uses the exhaust gas of the gas turbine 9 as fuel combustion gas in the boiler body 1 and heats the feed water to the boiler body 1 by the high-pressure feed water heater 3 and the gas high-pressure feed water heater 11. An outlet feed water temperature control device for a gas high pressure feed water heater in an exhaust recombustion type combined cycle plant,
A function generator 24 that outputs an outlet feed water temperature set value 25 of the gas high-pressure feed water heater 11 based on the boiler load command 19;
A function generator 26 that outputs a feed water flow rate setting value 27 of the high-pressure feed water heater 3 based on the boiler load command 19;
The difference between the outlet feed water temperature set value 25 of the gas high-pressure feed water heater 11 output from the function generator 24 and the outlet feed water temperature 18 of the gas high-pressure feed water heater 11 is obtained, and the subtraction to output the outlet feed water temperature deviation 29 Vessel 28;
A subtractor that obtains a difference between the minimum feed water flow rate set value 31 of the high pressure feed water heater 3 and the feed water flow rate set value 27 of the high pressure feed water heater 3 output from the function generator 26 and outputs a flow rate set value deviation 33 32,
The outlet feed water temperature deviation 29 of the gas high pressure feed water heater 11 output from the subtractor 28 is proportionally integrated to obtain a feed water flow rate correction value of the high pressure feed water heater 3, and a feed water flow rate correction value of the high pressure feed water heater 3. Is larger than the flow rate set value deviation 33 output from the subtractor 32, the feed water flow rate correction value of the high pressure feed water heater 3 is output as it is as a correction command 35, while the feed water flow rate of the high pressure feed water heater 3 is output. When the correction value is less than or equal to the flow rate set value deviation 33 output from the subtractor 32, the proportional integral controller 34 with a low signal limiter that outputs the flow rate set value deviation 33 as a correction command 35;
The correction command 35 output from the proportional integral controller 34 with a low signal limiter is added to the feed water flow rate setting value 27 of the high pressure feed water heater 3 output from the function generator 26, and the feed water of the high pressure feed water heater 3 is added. An adder 36 for outputting a flow rate correction set value 37;
The difference between the feed water flow rate 23 flowing through the high pressure feed water heater 3 and the feed water flow rate correction setting value 37 of the high pressure feed water heater 3 output from the adder 36 is obtained, and the feed water flow rate deviation 39 of the high pressure feed water heater 3 is calculated. An output subtractor 38;
A proportional integral controller 40 for proportionally integrating the feed water flow rate deviation 39 of the high pressure feed water heater 3 output from the subtractor 38 and outputting an opening degree command 21 to the flow rate regulating valve 12 of the high pressure feed water heater 3; The present invention relates to an outlet feed water temperature control device for a gas high-pressure feed water heater in an exhaust gas reburning combined cycle plant.
[0009]
According to the above means, the following operation can be obtained.
[0010]
[0011]
In the outlet high-pressure feed water temperature control device for the high-pressure gas feed water heater in the exhaust recombustion combined cycle plant of the present invention, the function generator 24 obtains the outlet feed water temperature set value 25 for the high-pressure gas feed water heater 11 based on the boiler load command 19. Is output to the subtractor 28, and the feed water flow rate set value 27 of the high pressure feed water heater 3 is obtained by the function generator 26 based on the boiler load command 19 and is output to the subtractor 32 and the adder 36. The difference between the outlet feed water temperature setting value 25 of the gas high-pressure feed water heater 11 output from the function generator 24 and the outlet feed water temperature 18 of the gas high-pressure feed water heater 11 detected by the temperature detector 17 is obtained. , The outlet feed water temperature deviation 29 is output to the proportional integral controller 34 with a low signal limiter, and in the subtractor 32 the feed water minimum of the high pressure feed water heater 3 is output. The difference between the amount set value 31 and the feed water flow rate set value 27 of the high pressure feed water heater 3 output from the function generator 26 is obtained, and the flow rate set value deviation 33 is transferred to the proportional integral controller 34 with a low signal limiter. The output feed water temperature deviation 29 of the gas high-pressure feed water heater 11 output from the subtractor 28 in the proportional integral controller 34 with a low signal limiter is proportionally integrated to correct the feed water flow rate of the high pressure feed water heater 3. When the value is obtained and the feed water flow rate correction value of the high pressure feed water heater 3 is larger than the flow rate set value deviation 33 output from the subtractor 32, the feed water flow rate correction value of the high pressure feed water heater 3 is corrected as it is. When the feed water flow rate correction value of the high pressure feed water heater 3 is less than or equal to the flow rate set value deviation 33 output from the subtractor 32, the flow rate set value deviation 33 is output as the command 35 to the adder 36. correction Is output to the adder 36 as an instruction 35, and is output from the proportional integral controller 34 with a low signal limiter to the feed water flow rate set value 27 of the high pressure feed water heater 3 output from the function generator 26 in the adder 36. The correction command 35 is added, the feed water flow rate correction set value 37 of the high pressure feed water heater 3 is output to the subtractor 38, and the feed water flowing through the high pressure feed water heater 3 output from the subtracter 22 in the subtractor 38. The difference between the flow rate 23 and the feed water flow rate correction set value 37 of the high pressure feed water heater 3 output from the adder 36 is obtained, and the feed water flow rate deviation 39 of the high pressure feed water heater 3 is output to the proportional integration controller 40. In the proportional-plus-integral regulator 40, the feed water flow rate deviation 39 of the high-pressure feed water heater 3 output from the subtractor 38 is proportional-integrated, and the opening degree command 21 is output to the flow rate adjusting valve 12. 21, the opening of the flow rate adjusting valve 12 is adjusted, the flow rate of the feed water distributed to the high pressure feed water heater 3 and the gas high pressure feed water heater 11 is adjusted, and the outlet feed water temperature of the gas high pressure feed water heater 11 is the outlet. The feed water temperature is set to a set value 25.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0013]
1 to 4 show an example of an embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 6 denote the same parts, and 13 detects the discharge flow rate 14 of the feed water pump 2. 15 is a flow rate detector for detecting the feed water flow rate 16 flowing through the gas high-pressure feed water heater 11, 17 is a temperature detector for detecting the outlet feed water temperature 18 of the gas high-pressure feed water heater 11, and 20 is the flow rate detector. The discharge flow rate 14 of the feed water pump 2 detected by the vessel 13, the feed water flow rate 16 flowing through the gas high pressure feed water heater 11 detected by the flow rate detector 15, and the gas high pressure feed water heating detected by the temperature detector 17. This is a controller that outputs an opening degree command 21 to the flow rate adjustment valve 12 of the high-pressure feed water heater 3 based on the outlet feed water temperature 18 of the vessel 11 and the boiler load command (MWD) 19.
[0014]
As shown in FIG. 2, the controller 20 includes a discharge flow rate 14 of the feed water pump 2 detected by the flow rate detector 13 and a feed water flow rate 16 flowing through the gas high-pressure feed water heater 11 detected by the flow rate detector 15. And a subtractor 22 that outputs a feed water flow rate 23 flowing through the high-pressure feed water heater 3,
A function generator 24 for obtaining and outputting an outlet feed water temperature set value 25 of the gas high-pressure feed water heater 11 based on the boiler load command 19;
A function generator 26 for obtaining and outputting a feed water flow rate set value 27 of the high pressure feed water heater 3 based on the boiler load command 19;
The difference between the outlet feed water temperature setting value 25 of the gas high-pressure feed water heater 11 output from the function generator 24 and the outlet feed water temperature 18 of the gas high-pressure feed water heater 11 detected by the temperature detector 17 is obtained. A subtractor 28 for outputting the outlet feed water temperature deviation 29;
Before steam extraction from the steam turbine 4 to the high pressure feed water heater 3, 0 [ton / h] is output as the minimum feed water flow rate set value 31 of the high pressure feed water heater 3 (switched to the a side), while the steam turbine 4 After steam extraction from the high pressure feed water heater 3 to α [ton / h] is output as the minimum feed water flow rate set value 31 of the high pressure feed water heater 3 (switched to the b side);
The difference between the minimum feed water flow rate setting value 31 of the high pressure feed water heater 3 output from the switch 30 and the feed water flow rate set value 27 of the high pressure feed water heater 3 output from the function generator 26 is obtained, and the flow rate setting is performed. A subtractor 32 for outputting a value deviation 33;
The outlet feed water temperature deviation 29 of the gas high pressure feed water heater 11 output from the subtractor 28 is proportionally integrated to obtain a feed water flow rate correction value of the high pressure feed water heater 3, and a feed water flow rate correction value of the high pressure feed water heater 3. Is larger than the flow rate set value deviation 33 output from the subtractor 32, the feed water flow rate correction value of the high pressure feed water heater 3 is output as it is as a correction command 35, while the feed water flow rate of the high pressure feed water heater 3 is output. When the correction value is less than or equal to the flow rate set value deviation 33 output from the subtractor 32, the proportional integral controller 34 with a low signal limiter that outputs the flow rate set value deviation 33 as a correction command 35;
The correction command 35 output from the proportional integral controller 34 with a low signal limiter is added to the feed water flow rate setting value 27 of the high pressure feed water heater 3 output from the function generator 26, and the feed water of the high pressure feed water heater 3 is added. An adder 36 for outputting a flow rate correction set value 37;
The difference between the feed water flow rate 23 flowing through the high pressure feed water heater 3 output from the subtractor 22 and the feed water flow rate correction set value 37 of the high pressure feed water heater 3 output from the adder 36 is obtained, and the high pressure feed water heater A subtractor 38 for outputting a feed water flow deviation 39 of 3;
And a proportional integral controller 40 for proportionally integrating the feed water flow rate deviation 39 of the high pressure feed water heater 3 output from the subtractor 38 and outputting the opening degree command 21 to the flow rate adjusting valve 12. is doing.
[0015]
Incidentally, the function generator 24, the function F 1 (x) is input as shown in FIG. 3, The function F 1 (x) is substantially in proportion to the increase or decrease in boiler load command 19 This indicates that the outlet feed water temperature set value 25 of the gas high-pressure feed water heater 11 is increased or decreased.
[0016]
Further, the function generator 26, the function F 2 (x) as shown in FIG. 4 are input, the function number F 2 (x) is substantially in proportion to the increase or decrease in boiler load command 19 This indicates that the feed water flow rate set value 27 of the high pressure feed water heater 3 is increased or decreased.
[0017]
Next, the operation of the illustrated example will be described.
[0018]
During operation, the difference between the discharge flow rate 14 of the feed water pump 2 detected by the flow rate detector 13 and the feed water flow rate 16 flowing through the gas high-pressure feed water heater 11 detected by the flow rate detector 15 is the subtractor 22 of the controller 20. The feed water flow rate 23 flowing through the high pressure feed water heater 3 is output to the subtractor 38, and the outlet water feed temperature set value 25 of the gas high pressure feed water heater 11 is obtained by the function generator 24 based on the boiler load command 19. Based on the boiler load command 19, the function generator 26 obtains the feed water flow rate set value 27 of the high pressure feed water heater 3 and outputs it to the subtractor 32 and the adder 36. The outlet feed water temperature set value 25 of the gas high pressure feed water heater 11 output from the generator 24 and the outlet feed water temperature of the gas high pressure feed water heater 11 detected by the temperature detector 17. The difference between the 18 is required, the outlet feed water temperature deviation 29 is output to a low signal limiter with proportional integral adjuster 34.
[0019]
Here, before steam extraction from the steam turbine 4 to the high-pressure feed water heater 3, the input of the switch 30 is switched to the a side, and 0 [ton / h] is output from the switch 30 to the high-pressure feed water heater 3. The minimum feed water flow rate set value 31 is output to the subtractor 32, and the subtracter 32 outputs the minimum feed water flow rate set value 31 of the high pressure feed water heater 3 output from the switch 30 and the function generator 26. A difference from the feed water flow rate set value 27 of the high pressure feed water heater 3 is obtained, and a flow rate set value deviation 33 is output to the proportional integral controller 34 with a low signal limiter. The outlet feed water temperature deviation 29 of the gas high-pressure feed water heater 11 output from the subtractor 28 is proportionally integrated to obtain the feed water flow rate correction value of the high-pressure feed water heater 3, and the feed water flow rate correction of the high-pressure feed water heater 3 is obtained. The value is subtracted When the flow rate set value deviation 33 output from 32 is larger, the feed water flow rate correction value of the high pressure feed water heater 3 is output as it is to the adder 36 as a correction command 35, while the feed water of the high pressure feed water heater 3 is When the flow rate correction value is less than or equal to the flow rate set value deviation 33 output from the subtractor 32, the flow rate set value deviation 33 is output to the adder 36 as a correction command 35, and the function generator The correction command 35 output from the proportional integral controller 34 with a low signal limiter is added to the feed flow rate set value 27 of the high pressure feed water heater 3 output from 26, and the feed water flow rate correction setting of the high pressure feed water heater 3 is added. The value 37 is output to the subtractor 38, and the feed water flow rate 23 flowing through the high pressure feed water heater 3 output from the subtractor 22 in the subtractor 38 and the high pressure feed supplied from the adder 36. The difference from the feed water flow rate correction set value 37 of the heater 3 is obtained, and the feed water flow rate deviation 39 of the high pressure feed water heater 3 is output to the proportional-plus-integral adjuster 40, which is output from the subtractor 38. The feed water flow rate deviation 39 of the high-pressure feed water heater 3 is proportionally integrated and an opening degree command 21 is output to the flow rate regulating valve 12, and the opening degree of the flow rate regulating valve 12 is adjusted according to the opening degree command 21, The flow rate of the feed water distributed to the high pressure feed water heater 3 and the gas high pressure feed water heater 11 is adjusted, and the outlet feed water temperature of the gas high pressure feed water heater 11 is controlled to the outlet feed water temperature set value 25.
[0020]
The actual outlet feed water temperature 18 of the gas high-pressure feed water heater 11 becomes very high, and the flow rate of the feed water flowing to the gas high-pressure feed water heater 11 needs to be greatly increased. A feed water flow rate correction value of the high pressure feed water heater 3 obtained by proportional integration processing of the outlet feed water temperature deviation 29 of the gas high pressure feed water heater 11 output from the subtractor 28 in the proportional integration controller 34 is output from the subtractor 32. When the flow rate set value deviation 33 is less than or equal to the flow rate set value deviation 33, the flow rate set value deviation 33 is output to the adder 36 as a correction command 35. The high pressure feed water heating output from the function generator 26 in the adder 36 is output. Since the correction command 35 output from the proportional integral controller 34 with the low signal limiter is added to the feed water flow rate setting value 27 of the vessel 3, 0 [ton / h] is consequently obtained as the high pressure feed water heater. The feed water flow rate correction set value 37 is output to the subtractor 38, the flow rate adjustment valve 12 is fully closed, and no feed water is circulated to the high pressure feed water heater 3. Since it is before steam extraction from the turbine 4 to the high-pressure feed water heater 3, there is no concern that the high-pressure feed water heater 3 is damaged by heat.
[0021]
On the other hand, after steam extraction from the steam turbine 4 to the high pressure feed water heater 3, the input of the switch 30 is switched to the b side, and α [ton / h] from the switch 30 is the lowest feed water of the high pressure feed water heater 3. The flow rate set value 31 is output to the subtractor 32, and the subtracter 32 outputs the minimum feed water flow rate set value 31 of the high pressure feed water heater 3 output from the switch 30 and the high pressure feed water output from the function generator 26. A difference from the feed water flow rate set value 27 of the heater 3 is obtained, and a flow rate set value deviation 33 is output to the proportional integral controller 34 with a low signal limiter. The outlet feed water temperature deviation 29 of the gas high pressure feed water heater 11 output from the vessel 28 is proportionally integrated to obtain a feed water flow rate correction value of the high pressure feed water heater 3, and the feed water flow rate correction value of the high pressure feed water heater 3 is The subtractor 2 is larger than the flow rate set value deviation 33 output from 2, the feed water flow rate correction value of the high pressure feed water heater 3 is directly output to the adder 36 as a correction command 35, while the feed water of the high pressure feed water heater 3 is supplied. When the flow rate correction value is less than or equal to the flow rate set value deviation 33 output from the subtractor 32, the flow rate set value deviation 33 is output to the adder 36 as a correction command 35, and the function generator The correction command 35 output from the proportional integral controller 34 with a low signal limiter is added to the feed flow rate set value 27 of the high pressure feed water heater 3 output from 26, and the feed water flow rate correction setting of the high pressure feed water heater 3 is added. The value 37 is output to the subtractor 38, and the subtractor 38 outputs the feed water flow rate 23 flowing through the high pressure feed water heater 3 output from the subtractor 22 and the high pressure feed water addition output from the adder 36. The difference from the feed water flow rate correction set value 37 of the heater 3 is obtained, and the feed water flow rate deviation 39 of the high pressure feed water heater 3 is output to the proportional integral controller 40, and the proportional integral controller 40 outputs from the subtractor 38. The feed water flow rate deviation 39 of the high-pressure feed water heater 3 is proportionally integrated and an opening degree command 21 is output to the flow rate regulating valve 12, and the opening degree of the flow rate regulating valve 12 is adjusted according to the opening degree command 21, The flow rate of the feed water distributed to the high pressure feed water heater 3 and the gas high pressure feed water heater 11 is adjusted, and the outlet feed water temperature of the gas high pressure feed water heater 11 is controlled to the outlet feed water temperature set value 25.
[0022]
In addition, after steam extraction from the steam turbine 4 to the high-pressure feed water heater 3, the actual outlet feed water temperature 18 of the gas high-pressure feed water heater 11 becomes very high, and the flow rate of feed water to be circulated to the gas high-pressure feed water heater 11. The high-pressure feed water is obtained by proportionally integrating the outlet feed water temperature deviation 29 of the gas high-pressure feed water heater 11 output from the subtractor 28 in the proportional integral controller 34 with a low signal limiter. When the feed water flow rate correction value of the heater 3 becomes equal to or less than the flow rate set value deviation 33 output from the subtractor 32, the flow rate set value deviation 33 is output as a correction command 35 to the adder 36, and the addition The correction command 35 output from the proportional integral controller 34 with a low signal limiter is added to the feed flow rate set value 27 of the high pressure feed water heater 3 output from the function generator 26 in the generator 36. As a result, α [ton / h] is output to the subtractor 38 as the feed water flow rate correction set value 37 of the high pressure feed water heater 3, and the flow rate adjustment valve 12 is not fully closed, and the high pressure feed water heating is performed. Thus, the water supply of α [ton / h] always circulates in the vessel 3, the minimum supply water flow rate of the high-pressure feed water heater 3 is ensured, and the high-pressure feed water heater 3 is protected from heat.
[0023]
Thus, by adjusting the opening of the flow rate adjustment valve 12 of the high pressure feed water heater 3, the flow rate of the feed water distributed to the high pressure feed water heater 3 and the gas high pressure feed water heater 11 is adjusted, and the outlet of the gas high pressure feed water heater 11 is adjusted. The feed water temperature can be controlled, and furthermore, the minimum feed water flow rate of the high pressure feed water heater 3 can be secured to protect the high pressure feed water heater 3 from heat.
[0024]
In addition, the outlet feed water temperature control device of the gas high-pressure feed water heater in the exhaust recombustion combined cycle plant of the present invention is not limited to the above illustrated example, and the discharge flow rate of the feed water pump detected by the flow rate detector Instead of obtaining the feed water flow rate flowing through the high pressure feed water heater 3 from the difference between the feed water flow rate flowing through the gas high pressure feed water heater 11 detected by the flow rate detector, the feed water flow rate flowing through the high pressure feed water heater 3 is directly detected. It goes without saying that various modifications can be made without departing from the scope of the present invention, such as being allowed to do so.
[0025]
【The invention's effect】
As described above, according to the outlet feed water temperature control device for the gas high-pressure feed water heater in the exhaust reburning combined cycle plant of the present invention, the high-pressure feed water is adjusted by adjusting the opening of the flow rate adjustment valve 12 of the high-pressure feed water heater 3. The flow rate of the feed water distributed to the heater 3 and the gas high pressure feed water heater 11 can be adjusted, the outlet feed water temperature of the gas high pressure feed water heater 11 can be controlled, and the minimum feed water flow rate of the high pressure feed water heater 3 can be secured. Thus, an excellent effect that the high-pressure feed water heater 3 can be protected from heat can be obtained.
[Brief description of the drawings]
1 is an overall schematic configuration diagram of an example of an embodiment for carrying out the present invention;
FIG. 2 is a block diagram illustrating details of a controller in an example of an embodiment of the present invention.
FIG. 3 is a diagram representing a function set in the function generator 24 shown in FIG. 2;
4 is a diagram representing a function set in the function generator 26 shown in FIG. 2. FIG.
FIG. 5 is an overall schematic configuration diagram of an example of a power plant using a conventional general boiler.
FIG. 6 is an overall schematic configuration diagram of an example of an exhaust-fired combined cycle plant proposed in recent years.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Boiler main body 3 High pressure feed water heater 9 Gas turbine 11 Gas high pressure feed water heater 12 Flow rate adjustment valve 16 Feed water flow rate 18 Outlet feed water temperature 19 Boiler load command 20 Controller 21 Opening command 23 Feed water flow rate 24 Function generator 25 Outlet feed water temperature Set value 26 Function generator 27 Feed water flow set value 28 Subtractor 29 Outlet feed water temperature deviation 31 Feed water minimum flow set value 32 Subtractor 33 Flow set value deviation 34 Proportional integral controller with low signal limiter 35 Correction command 36 Adder 37 Feedwater flow rate correction set value 38 Subtractor 39 Feedwater flow rate deviation 40 Proportional integral controller

Claims (1)

ガスタービン（９）の排ガスをボイラ本体（１）において燃料の燃焼用ガスとして使用すると共に、高圧給水加熱器（３）とガス高圧給水加熱器（１１）とによりボイラ本体（１）への給水を加熱するようにした排気再燃型コンバインドサイクルプラントにおけるガス高圧給水加熱器の出口給水温度制御装置であって、
ボイラ負荷指令（１９）に基づきガス高圧給水加熱器（１１）の出口給水温度設定値（２５）を出力する関数発生器（２４）と、
ボイラ負荷指令（１９）に基づき高圧給水加熱器（３）の給水流量設定値（２７）を出力する関数発生器（２６）と、
前記関数発生器（２４）から出力されるガス高圧給水加熱器（１１）の出口給水温度設定値（２５）と、ガス高圧給水加熱器（１１）の出口給水温度（１８）との差を求め、出口給水温度偏差（２９）を出力する減算器（２８）と、
高圧給水加熱器（３）の給水最低流量設定値（３１）と、前記関数発生器（２６）から出力される高圧給水加熱器（３）の給水流量設定値（２７）との差を求め、流量設定値偏差（３３）を出力する減算器（３２）と、
前記減算器（２８）から出力されるガス高圧給水加熱器（１１）の出口給水温度偏差（２９）を比例積分処理して高圧給水加熱器（３）の給水流量補正値を求め、該高圧給水加熱器（３）の給水流量補正値が前記減算器（３２）から出力される流量設定値偏差（３３）より大きい場合には、前記高圧給水加熱器（３）の給水流量補正値をそのまま補正指令（３５）として出力する一方、前記高圧給水加熱器（３）の給水流量補正値が前記減算器（３２）から出力される流量設定値偏差（３３）以下の場合には、該流量設定値偏差（３３）を補正指令（３５）として出力する低信号制限器付比例積分調節器（３４）と、
前記関数発生器（２６）から出力される高圧給水加熱器（３）の給水流量設定値（２７）に対し前記低信号制限器付比例積分調節器（３４）から出力される補正指令（３５）を加え、高圧給水加熱器（３）の給水流量補正設定値（３７）を出力する加算器（３６）と、
前記高圧給水加熱器（３）を流れる給水流量（２３）と、前記加算器（３６）から出力される高圧給水加熱器（３）の給水流量補正設定値（３７）との差を求め、高圧給水加熱器（３）の給水流量偏差（３９）を出力する減算器（３８）と、
該減算器（３８）から出力される高圧給水加熱器（３）の給水流量偏差（３９）を比例積分処理して前記高圧給水加熱器（３）の流量調整弁（１２）へ開度指令（２１）を出力する比例積分調節器（４０）と
を備えたことを特徴とする排気再燃型コンバインドサイクルプラントにおけるガス高圧給水加熱器の出口給水温度制御装置。The exhaust gas from the gas turbine (9) is used as fuel combustion gas in the boiler body (1), and water is supplied to the boiler body (1) by the high-pressure feed water heater (3) and the gas high-pressure feed water heater (11). An outlet feed water temperature control device for a gas high-pressure feed water heater in an exhaust reburning combined cycle plant that heats
A function generator (24) for outputting an outlet feed water temperature setting value (25) of the gas high-pressure feed water heater (11) based on the boiler load command (19);
A function generator (26) for outputting a feed water flow rate set value (27) of the high-pressure feed water heater (3) based on the boiler load command (19);
The difference between the outlet feed water temperature setting value (25) of the gas high-pressure feed water heater (11) output from the function generator (24) and the outlet feed water temperature (18) of the gas high-pressure feed water heater (11) is obtained. A subtractor (28) for outputting the outlet feed water temperature deviation (29);
The difference between the feed water minimum flow rate setting value (31) of the high pressure feed water heater (3) and the feed water flow rate setting value (27) of the high pressure feed water heater (3) output from the function generator (26) is obtained. A subtractor (32) for outputting a flow rate set value deviation (33);
The outlet water temperature deviation (29) of the gas high-pressure feed water heater (11) output from the subtractor (28) is proportionally integrated to obtain a feed water flow rate correction value for the high-pressure feed water heater (3). When the feed water flow rate correction value of the heater (3) is larger than the flow rate set value deviation (33) output from the subtractor (32), the feed water flow rate correction value of the high pressure feed water heater (3) is corrected as it is. If the feed water flow rate correction value of the high pressure feed water heater (3) is less than or equal to the flow rate set value deviation (33) output from the subtractor (32), the flow rate set value is output as the command (35). A proportional integral controller (34) with a low signal limiter that outputs the deviation (33) as a correction command (35);
Correction command (35) output from the proportional integral controller (34) with a low signal limiter for the feed water flow rate setting value (27) of the high pressure feed water heater (3) output from the function generator (26) And an adder (36) for outputting the feed water flow rate correction set value (37) of the high pressure feed water heater (3),
A difference between a feed water flow rate (23) flowing through the high pressure feed water heater (3) and a feed water flow rate correction setting value (37) of the high pressure feed water heater (3) output from the adder (36) is obtained. A subtractor (38) for outputting a feed water flow deviation (39) of the feed water heater (3);
The feed water flow deviation (39) of the high pressure feed water heater (3) output from the subtractor (38) is proportionally integrated and subjected to an opening degree command (12) to the flow rate adjustment valve (12) of the high pressure feed water heater (3). 21) A proportional integral controller (40) for outputting the output, and an outlet feed water temperature control device for a gas high-pressure feed water heater in an exhaust-fired combined cycle plant.
JP19760796A 1996-07-26 1996-07-26 Outlet feed water temperature control device for gas high pressure feed water heater in exhaust recombustion combined cycle plant Expired - Fee Related JP3845905B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP19760796A JP3845905B2 (en) 1996-07-26 1996-07-26 Outlet feed water temperature control device for gas high pressure feed water heater in exhaust recombustion combined cycle plant

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP19760796A JP3845905B2 (en) 1996-07-26 1996-07-26 Outlet feed water temperature control device for gas high pressure feed water heater in exhaust recombustion combined cycle plant

Publications (2)

Publication Number Publication Date
JPH1038201A JPH1038201A (en) 1998-02-13
JP3845905B2 true JP3845905B2 (en) 2006-11-15

Family

ID=16377292

Family Applications (1)

Application Number Title Priority Date Filing Date
JP19760796A Expired - Fee Related JP3845905B2 (en) 1996-07-26 1996-07-26 Outlet feed water temperature control device for gas high pressure feed water heater in exhaust recombustion combined cycle plant

Country Status (1)

Country Link
JP (1) JP3845905B2 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5723220B2 (en) * 2011-05-31 2015-05-27 株式会社東芝 Power plant
JP6006981B2 (en) * 2012-05-25 2016-10-12 株式会社テイエルブイ Drain flow meter

Also Published As

Publication number Publication date
JPH1038201A (en) 1998-02-13

Similar Documents

Publication Publication Date Title
US4572110A (en) Combined heat recovery and emission control system
JP2680033B2 (en) Method and apparatus for operating combined plant
KR101530807B1 (en) Exhaust heat recovery boiler and electricity generation plant
GB2166199A (en) Heat recovery steam generator outlet temperature control system for a combined cycle power plant
JP4885199B2 (en) Gas turbine operation control apparatus and method
EP0928882B1 (en) Steam cooling apparatus for gas turbine
CN112334636A (en) Composite power generation facility and method for operating same
JP4374798B2 (en) Mill primary air flow controller for pulverized coal fired boiler equipment
JP2000130108A (en) Starting method for combined cycle power plant
JP3845905B2 (en) Outlet feed water temperature control device for gas high pressure feed water heater in exhaust recombustion combined cycle plant
US4145995A (en) Method of operating a power plant and apparatus therefor
JP4859512B2 (en) Combustion boiler control method
JP3932628B2 (en) Boiler exhaust gas flow rate control method and apparatus for air preheater in exhaust recombustion combined cycle power plant
JP3312499B2 (en) Fuel cell generator
JP3882294B2 (en) Combustion air flow rate control method and apparatus in exhaust recombustion combined cycle power plant
JP2000266310A (en) Pressure fluidized bed boiler and control method thereof
JP3697731B2 (en) Main steam temperature controller in exhaust recombustion combined cycle plant
JP3820636B2 (en) Method and apparatus for controlling feed water temperature in exhaust recombustion combined cycle plant
JPH06123238A (en) Control method of operating circulation type power system
JPH1054508A (en) Temperature control method and apparatus for main steam
JP3354776B2 (en) Operation method of incinerator complex plant equipment
JPH04313601A (en) Boiler equipment
JP2002168406A (en) Reheat steam temperature controller for boiler
JP2004353994A (en) Reheated steam temperature control device and control method
JPH09236202A (en) Apparatus and method for controlling fuel of boiler

Legal Events

Date Code Title Description
A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20060523

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20060616

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20060801

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20060814

S533 Written request for registration of change of name

Free format text: JAPANESE INTERMEDIATE CODE: R313533

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20090901

Year of fee payment: 3

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20100901

Year of fee payment: 4

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110901

Year of fee payment: 5

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110901

Year of fee payment: 5

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120901

Year of fee payment: 6

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120901

Year of fee payment: 6

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130901

Year of fee payment: 7

LAPS Cancellation because of no payment of annual fees