JP3697316B2

JP3697316B2 - Moisture separator heater protection device for nuclear power plant

Info

Publication number: JP3697316B2
Application number: JP12927496A
Authority: JP
Inventors: 賢治熊谷
Original assignee: Toshiba Corp
Current assignee: Toshiba Corp
Priority date: 1996-04-26
Filing date: 1996-04-26
Publication date: 2005-09-21
Anticipated expiration: 2016-04-26
Also published as: JPH09292107A

Description

【０００１】
【発明の属する技術分野】
本発明は、原子炉圧力制御を行う原子力発電所における湿分分離加熱器を保護するための原子力発電所の湿分分離加熱器保護装置に関する。
【０００２】
【従来の技術】
図１１は、原子炉圧力制御を行う原子力発電所におけるタービン設備の概略図である。原子炉１で発生した蒸気は、主蒸気管２を介して蒸気止め弁４及び蒸気加減弁５に至り高圧タービン３に導かれ、高圧タービン３を駆動する。
【０００３】
一方、主蒸気管２の途中には、主蒸気隔離弁６と主蒸気ヘッダ７とがあり、主蒸気ヘッダ７からは主蒸気を直接復水器８へ導くタービンバイパス管９と、湿分分離加熱器１０に主蒸気を供給する加熱蒸気管１１とが分岐している。タービンバイパス配管９には、タービンバイパス弁１３が設けられ、このタービンバイパス弁１３は原子炉圧力検出器１２からの原子炉圧力に基づいてタービンバイパス弁制御装置２３により制御される。また、湿分分離加熱器１０に主蒸気を供給する加熱蒸気管１１には湿分分離加熱器１０への加熱蒸気の流入を閉止する加熱蒸気元弁１４と、加熱蒸気圧力調節弁１５が設置されている。
【０００４】
高圧タービン３と低圧タービン１６とはクロスアラウンド管１７によって連絡されており、このクロスアラウンド管１７の途中に主蒸気を加熱源とする加熱器１８を内蔵した湿分分離加熱器１０が設置されている。つまり、高圧タービン３で仕事を終えた蒸気は湿分分離加熱器１０を通って低圧タービン１６に導かれ、低圧タービン１６を駆動する。低圧タービン１６で仕事を終えた排気蒸気は、復水器８において凝縮され、その後、昇圧ポンプ２０および給水加熱器１９を介して昇温、昇圧されて原子炉１へ戻される。
【０００５】
この様な原子炉圧力制御を行う原子力発電所のタービン設備において、主蒸気隔離弁６が全閉した場合は、原子炉１の炉圧力が上昇し、プラント停止となる。その過程で原子炉圧力検出器１２からの信号を受けたタービンバイパス弁制御装置２３は、タービンバイパス弁１３を開動作する。つまり、主蒸気隔離弁６が閉すると原子炉圧力が上昇を始めるので、このとき炉圧力の上昇を抑制すべくタービンバイパス弁１３は開動作して、主蒸気ヘッダ７から復水器８へ主蒸気が排出される。
【０００６】
【発明が解決しようとする課題】
しかし、原子炉１からタービンバイパス弁１３への主蒸気管２の途中に設置された主蒸気隔離弁６の閉により、原子炉１内の蒸気を復水器８へ導くことができず、結果としてはタービンバイパス弁１３の開により主蒸気隔離弁６の２次側の蒸気圧力が急速に低下していくことになる。
【０００７】
主蒸気隔離弁６の２次側圧力の低下により加熱器１８の器内圧力は低下し、加熱器１８の蒸気温度はその器内圧力の飽和温度に従い低下する。このため、加熱器１８の器内温度も低下する。したがって、急激な器内圧力の変化は器内の温度分布を急変させるため過度の熱応力を発生させる可能性があり、湿分分離加熱器１０の健全性が維持出来ずプラントの信頼性の面で問題があった。
【０００８】
本発明の目的は、主蒸気隔離弁が閉した場合であっても、湿分分離加熱器の器内圧力の急減を防止しその健全性を維持することができる原子力発電所の湿分分離加熱器保護装置を提供することである。
【０００９】
【課題を解決するための手段】
請求項１の発明は、原子力発電所の主タービンで仕事を終えた蒸気に含まれる湿分を、原子炉からの主蒸気を供給して除去するようにした湿分分離加熱器を保護するための原子力発電所の湿分分離加熱器保護装置であり、原子炉出口に設けられた主蒸気隔離弁の弁状態を検出する弁状態検出装置と、弁状態検出装置からの信号に基づいて主蒸気隔離弁の弁状態を判定する弁状態判定手段と、弁状態判定手段により主蒸気隔離弁が全開以外の弁状態であると判定されたときはタービンバイパス弁の全閉操作を行うと共にタービントリップ操作を行う制御手段とを備えたものである。
【００１０】
請求項１の発明では、主蒸気隔離弁の弁状態を弁状態検出装置で検出し、弁状態判定手段は弁状態検出装置からの信号に基づいて主蒸気隔離弁の弁状態を判定する。そして、制御手段は、弁状態判定手段により主蒸気隔離弁が全開以外の弁状態であると判定されたときは、タービンバイパス弁の全閉操作を行うと共にタービントリップ操作を行う。
【００１１】
請求項２の発明は、原子力発電所の主タービンで仕事を終えた蒸気に含まれる湿分を原子炉からの主蒸気を供給して除去するようにした湿分分離加熱器を保護するための原子力発電所の湿分分離加熱器保護装置であり、原子炉出口に設けられた主蒸気隔離弁の２次側圧力を検出する２次側圧力検出器と、２次側圧力検出器からの信号に基づいて主蒸気隔離弁の２次側圧力が所定値以下であるか否かを判定する２次側圧力判定手段と、２次側圧力判定手段により主蒸気隔離弁の２次側圧力が所定値以下であると判定されたときはタービンバイパス弁の全閉操作を行うと共にタービントリップ操作を行う制御手段とを備えたものである。
【００１２】
請求項２の発明では、主蒸気隔離弁の２次側圧力を２次側圧力検出器で検出し、２次側圧力判定手段は、２次側圧力検出器からの信号に基づいて主蒸気隔離弁の２次側圧力が所定値以下であるか否かを判定する。そして、制御手段は、２次側圧力判定手段により主蒸気隔離弁の２次側圧力が所定値以下であると判定されたときはタービンバイパス弁の全閉操作を行うと共にタービントリップ操作を行う。
【００１３】
請求項３の発明は、原子力発電所の主タービンで仕事を終えた蒸気に含まれる湿分を原子炉からの主蒸気を供給して除去するようにした湿分分離加熱器を保護するための原子力発電所の湿分分離加熱器保護装置であり、原子炉出口に設けられた主蒸気隔離弁の２次側圧力を検出する２次側圧力検出器と、２次側圧力検出器からの信号に基づいて主蒸気隔離弁の２次側圧力の変化率が所定値より大であるか否かを判定する２次側圧力変化率判定手段と、２次側圧力変化率判定手段により主蒸気隔離弁の２次側圧力変化率が所定値より大であると判定されたときはタービンバイパス弁の全閉操作を行うと共にタービントリップ操作を行う制御手段とを備えたものである。
【００１４】
請求項３の発明では、主蒸気隔離弁の２次側圧力を２次側圧力検出器で検出し、２次側圧力変化率判定手段は、２次側圧力検出器からの信号に基づいて主蒸気隔離弁の２次側圧力の変化率が所定値より大であるか否かを判定する。そして、制御手段は、２次側圧力変化率判定手段により主蒸気隔離弁の２次側圧力変化率が所定値より大であると判定されたときはタービンバイパス弁の全閉操作を行うと共にタービントリップ操作を行う。
【００１５】
請求項４の発明は、原子力発電所の主タービンで仕事を終えた蒸気に含まれる湿分を原子炉からの主蒸気を供給して除去するようにした湿分分離加熱器を保護するための原子力発電所の湿分分離加熱器保護装置であり、原子炉出口に設けられた主蒸気隔離弁の１次側圧力を検出する１次側圧力検出器と、主蒸気隔離弁の２次側圧力を検出する２次側圧力検出器と、１次側圧力検出器及び２次側圧力検出器からの信号に基づいて主蒸気隔離弁の１次側圧力と２次側圧力との圧力偏差が所定値より大であるか否かを判定する圧力偏差判定手段と、圧力偏差判定手段により主蒸気隔離弁の１次側圧力と２次側圧力との圧力偏差が所定値より大であると判定されたときはタービンバイパス弁の全閉操作を行うと共にタービントリップ操作を行う制御手段とを備えたものである。
【００１６】
請求項４の発明では、主蒸気隔離弁の１次側圧力を１次側圧力検出器で検出し、主蒸気隔離弁の２次側圧力を２次側圧力検出器で検出し、圧力偏差判定手段は、１次側圧力検出器及び２次側圧力検出器からの信号に基づいて主蒸気隔離弁の１次側圧力と２次側圧力との圧力偏差が所定値より大であるか否かを判定する。そして、制御手段は、圧力偏差判定手段により主蒸気隔離弁の１次側圧力と２次側圧力との圧力偏差が所定値より大であると判定されたときはタービンバイパス弁の全閉操作を行うと共にタービントリップ操作を行う。
【００１７】
請求項５の発明は、原子炉からの主蒸気を加熱蒸気元弁及び加熱蒸気圧力調整弁を介して湿分分離加熱器に導き、主タービンで仕事を終えた蒸気に含まれる湿分を湿分分離加熱器で除去するようにした原子力発電所の湿分分離加熱器保護装置であり、原子炉出口に設けられた主蒸気隔離弁の弁状態を検出する弁状態検出装置と、弁状態検出装置からの信号に基づいて主蒸気隔離弁の弁状態を判定する弁状態判定手段と、弁状態判定手段により主蒸気隔離弁が全開以外の弁状態であると判定されたときは加熱蒸気元弁又は加熱蒸気調節弁の全閉操作を行う制御手段とを備えたものである。
【００１８】
請求項５の発明では、主蒸気隔離弁の弁状態を弁状態検出装置で検出し、弁状態判定手段は、弁状態検出装置からの信号に基づいて主蒸気隔離弁の弁状態を判定する。そして、制御手段は、弁状態判定手段により主蒸気隔離弁が全開以外の弁状態であると判定されたときは加熱蒸気元弁又は加熱蒸気調節弁の全閉操作を行う。
【００１９】
請求項６の発明は、原子炉からの主蒸気を加熱蒸気元弁及び加熱蒸気圧力調整弁を介して湿分分離加熱器に導き、主タービンで仕事を終えた蒸気に含まれる湿分を湿分分離加熱器で除去するようにした原子力発電所の湿分分離加熱器保護装置であり、原子炉出口に設けられた主蒸気隔離弁の２次側圧力を検出する２次側圧力検出器と、２次側圧力検出器からの信号に基づいて主蒸気隔離弁の２次側圧力が所定値以下であるか否かを判定する２次側圧力判定手段と、２次側圧力判定手段により主蒸気隔離弁の２次側圧力が所定値以下であると判定されたときは加熱蒸気元弁又は加熱蒸気調節弁の全閉操作を行う制御手段とを備えたものである。
【００２０】
請求項６の発明では、主蒸気隔離弁の２次側圧力を２次側圧力検出器で検出し、２次側圧力判定手段は、２次側圧力検出器からの信号に基づいて主蒸気隔離弁の２次側圧力が所定値以下であるか否かを判定する。そして、制御手段は、２次側圧力判定手段により主蒸気隔離弁の２次側圧力が所定値以下であると判定されたときは加熱蒸気元弁又は加熱蒸気調節弁の全閉操作を行う。
【００２１】
請求項７の発明は、原子炉からの主蒸気を加熱蒸気元弁及び加熱蒸気圧力調整弁を介して湿分分離加熱器に導き、主タービンで仕事を終えた蒸気に含まれる湿分を湿分分離加熱器で除去するようにした原子力発電所の湿分分離加熱器保護装置であり、原子炉出口に設けられた主蒸気隔離弁の２次側圧力を検出する２次側圧力検出器と、２次側圧力検出器からの信号に基づいて主蒸気隔離弁の２次側圧力の変化率が所定値より大であるか否かを判定する２次側圧力変化率判定手段と、２次側圧力変化率判定手段により主蒸気隔離弁の２次側圧力変化率が所定値より大であると判定されたときは加熱蒸気元弁又は加熱蒸気調節弁の全閉操作を行う制御手段とを備えたものである。
【００２２】
請求項７の発明では、主蒸気隔離弁の２次側圧力を２次側圧力検出器で検出し、２次側圧力変化率判定手段は、２次側圧力検出器からの信号に基づいて主蒸気隔離弁の２次側圧力の変化率が所定値より大であるか否かを判定する。そして、制御手段は、２次側圧力変化率判定手段により主蒸気隔離弁の２次側圧力変化率が所定値より大であると判定されたときは加熱蒸気元弁又は加熱蒸気調節弁の全閉操作を行う。
【００２３】
請求項８の発明は、原子炉からの主蒸気を加熱蒸気元弁及び加熱蒸気圧力調整弁を介して湿分分離加熱器に導き、主タービンで仕事を終えた蒸気に含まれる湿分を湿分分離加熱器で除去するようにした原子力発電所の湿分分離加熱器保護装置であり、原子炉出口に設けられた主蒸気隔離弁の１次側圧力を検出する１次側圧力検出器と、主蒸気隔離弁の２次側圧力を検出する２次側圧力検出器と、１次側圧力検出器及び２次側圧力検出器からの信号に基づいて主蒸気隔離弁の１次側圧力と２次側圧力との圧力偏差が所定値より大であるか否かを判定する圧力偏差判定手段と、圧力偏差判定手段により主蒸気隔離弁の１次側圧力と２次側圧力との圧力偏差が所定値より大であると判定されたときは加熱蒸気元弁又は加熱蒸気調節弁の全閉操作を行う制御手段とを備えたものである。
【００２４】
請求項８の発明では、主蒸気隔離弁の１次側圧力を１次側圧力検出器で検出し、主蒸気隔離弁の２次側圧力を２次側圧力検出器で検出し、圧力偏差判定手段は、１次側圧力検出器及び２次側圧力検出器からの信号に基づいて主蒸気隔離弁の１次側圧力と２次側圧力との圧力偏差が所定値より大であるか否かを判定する。そして、制御手段は、圧力偏差判定手段により主蒸気隔離弁の１次側圧力と２次側圧力との圧力偏差が所定値より大であると判定されたときは加熱蒸気元弁又は加熱蒸気調節弁の全閉操作を行う。
【００２７】
請求項９の発明は、請求項５乃至請求項８の発明において、湿分分離加熱器に供給する主蒸気を遮断するための遮断弁を加熱蒸気元弁の上流側に設け、制御手段は加熱蒸気元弁又は加熱蒸気調節弁に代えて遮断弁の全閉操作を行うようにしたものである。
【００２８】
請求項９の発明では、主蒸気隔離弁の２次側圧力が低下した状態のときに、遮断弁を全閉し湿分分離加熱器の器内圧力の低下を防止する。
【００２９】
【発明の実施の形態】
以下、本発明の実施の形態を説明する。図１は、本発明の第１の実施の形態を示す構成図である。図１において、弁状態検出装置２４は主蒸気隔離弁６の弁状態を検出するものであり、この弁状態検出装置２４で検出された主蒸気隔離弁の弁状態は、弁状態判定手段２５に入力される。弁状態判定手段２５は入力した弁状態に基づいて、主蒸気隔離弁６が全開以外の状態か否かを判定し、主蒸気隔離弁６の弁状態が全開以外の状態であるときは、制御手段２６に論理信号「１」を出力する。制御手段２６は、主蒸気隔離弁６が全開以外である信号を受けると、タービンバイパス弁１３の全閉操作と、タービントリップ操作とを行う。
【００３０】
すなわち、主蒸気隔離弁６に全閉事象が発生した場合には、原子炉圧力の入力信号に応じて動作するタービンバイパス弁１３への全閉操作と、タービントリップ操作による主蒸気止め弁４の全閉操作により、主蒸気隔離弁６の２次側圧力の急減を防ぐ。これにより、湿分分離加熱器１０の主蒸気を加熱源とする加熱器１８に過度の熱応力を発生させず、湿分分離加熱器１０の健全性を維持することができる。
【００３１】
以上の説明では、弁状態判定手段２５は主蒸気隔離弁６が全開以外の状態か否かを判定し、主蒸気隔離弁６が全開以外の状態のときに、制御手段２６はタービンバイパス弁１３の全閉操作及びタービントリップ操作とを行うようにしたが、主蒸気隔離弁６の弁開度が全閉となった場合に、そのように操作を行うようにしても良い。
【００３２】
次に、本発明の第２の実施の形態を説明する。図２は、本発明の第２の実施の形態を示す構成図である。図２において、２次側圧力検出器２７は主蒸気隔離弁６の２次側圧力を検出するものであり、この２次側圧力検出器２７で検出された主蒸気隔離弁の２次側圧力は、２次側圧力判定手段２８に入力される。２次側圧力判定手段２８では、２次側圧力検出器２７からの信号に基づいて主蒸気隔離弁６の２次側圧力が所定値以下であるか否かを判定する。そして、制御手段２６では、２次側圧力判定手段２８により主蒸気隔離弁６の２次側圧力が所定値以下であると判定されたときは、タービンバイパス弁１３の全閉操作を行うと共にタービントリップ操作を行う。
【００３３】
すなわち、主蒸気隔離弁６の２次側圧力が所定値を下回った場合に、タービンバイパス弁１３の全閉操作及びタービントリップ操作を行う。これにより、主蒸気隔離弁６の２次側圧力の急減を防ぐことが可能となり、湿分分離加熱器１０の主蒸気を加熱源とする加熱器１８に過度の熱応力を発生させず湿分分離加熱器の健全性を維持することができる。
【００３４】
次に、本発明の第３の実施の形態を説明する。図３は、本発明の第３の実施の形態を示す構成図である。図３において、２次側圧力検出器２７は主蒸気隔離弁６の２次側圧力を検出するものであり、この２次側圧力検出器２７で検出された主蒸気隔離弁の２次側圧力は、圧力変化率判定手段２９に入力される。圧力変化率判定手段２９は、２次側圧力検出器２７からの信号に基づいて主蒸気隔離弁６の２次側圧力の変化率を求め、その圧力変化率が所定値より大であるか否かを判定する。そして、制御手段２６では、圧力変化率判定手段２９により主蒸気隔離弁６の圧力変化率が所定値より大であると判定されたときは、タービンバイパス弁１３の全閉操作を行うと共にタービントリップ操作を行う。
【００３５】
すなわち、主蒸気隔離弁６の２次側圧力変化率が所定値を上回った場合に、タービンバイパス弁１３の全閉操作とタービントリップ操作とを行う。これにより、主蒸気隔離弁６の２次側圧力の急減を防ぐことが可能となり、湿分分離加熱器１０に過度の熱応力で発生させることを防止し、湿分分離加熱器１０の健全性を維持することができる。
【００３６】
次に、本発明の第４の実施の形態を説明する。図４は、本発明の第４の実施の形態を示す構成図である。図４において、主蒸気隔離弁６の１次側圧力は１次側圧力検出器３０で検出され、また、主蒸気隔離弁６の２次側圧力は２次側圧力検出器２７で検出される。１次側圧力検出器３０で検出された主蒸気隔離弁６の１次側圧力及び２次側圧力検出器２７で検出された主蒸気隔離弁６の２次側圧力は、圧力偏差判定手段３１に入力される。圧力偏差判定手段３１は、１次側圧力検出器３０及び２次側圧力検出器２７からの信号に基づいて、主蒸気隔離弁６の１次側圧力と２次側圧力との圧力偏差が所定値より大であるか否かを判定する。そして、圧力偏差判定手段３１により主蒸気隔離弁６の１次側圧力と２次側圧力との圧力偏差が所定値より大であると判定されたときは、制御手段２６はタービンバイパス弁の全閉操作を行うと共にタービントリップ操作を行う。
【００３７】
すなわち、主蒸気隔離弁６の２次側圧力と原子炉圧力（主蒸気隔離弁６の１次側圧力）との圧力偏差により、タービンバイパス弁１３の全閉操作とタービントリップを行う。これにより、主蒸気隔離弁６の２次側圧力の急減を防ぐことが可能となり、湿分分離加熱器１０に過度の熱応力を発生させず、湿分分離加熱器１０の健全性を維持することができる。
【００３８】
次に、本発明の第５の実施の形態を説明する。図５は本発明の第５の実施の形態を示す構成図である。図５において、主蒸気隔離弁６の弁状態は弁状態検出装置２４で検出され、弁状態判定手段２５は、弁状態検出装置２４からの信号に基づいて主蒸気隔離弁６の弁状態を判定する。そして、制御手段２６は、弁状態判定手段２５により主蒸気隔離弁６が全開以外の弁状態であると判定されたときは加熱蒸気元弁１４又は加熱蒸気調節弁１５の全閉操作を行う。
【００３９】
すなわち、湿分分離加熱器１０は主蒸気を加熱源とする加熱器１８を有しており、この加熱器１８に主蒸気を供給する加熱蒸気管１１には、加熱蒸気元弁１４と加熱蒸気圧力調節弁１５とが設けられている。そこで、主蒸気隔離弁６が全開以外の弁状態であると判定されたときは加熱蒸気元弁１４の全閉操作を行う。たとえば、加熱蒸気元弁１４を１分以内に全閉する。これにより、加熱蒸気元弁１４の２次側圧力の急減を防ぐことが可能となり、湿分分離加熱器１０に過度の熱応力を発生させず湿分分離加熱器１０の健全性を維持することができる。また、加熱蒸気圧力調節弁１５を１分以内に全閉するようにしても良い。
【００４０】
次に、本発明の第６の実施の形態を説明する。図６は本発明の第６の実施の形態を示す構成図である。図６において、主蒸気隔離弁６の２次側圧力は２次側圧力検出器２７検出され、２次側圧力判定手段２８は、２次側圧力検出器２７からの信号に基づいて主蒸気隔離弁６の２次側圧力が所定値以下であるか否かを判定する。そして、制御手段２６は、２次側圧力判定手段２８により主蒸気隔離弁６の２次側圧力が所定値以下であると判定されたときは加熱蒸気元弁１４又は加熱蒸気調節弁１５の全閉操作を行う。
【００４１】
すなわち、湿分分離加熱器１０は主蒸気を加熱源とする加熱器１８を有しており、この加熱器１８に主蒸気を供給する加熱蒸気管１１には、加熱蒸気元弁１４と加熱蒸気圧力調節弁１５とが設けられている。そこで、主蒸気隔離弁６の２次側圧力が所定値以下であると判定されたときは加熱蒸気元弁１４の全閉操作を行う。たとえば、加熱蒸気元弁１４を１分以内に全閉する。これにより、加熱蒸気元弁１４の２次側圧力の急減を防ぐことが可能となり、湿分分離加熱器１０に過度の熱応力を発生させず湿分分離加熱器１０の健全性を維持することができる。また、加熱蒸気圧力調節弁１５を１分以内に全閉するようにしても良い。
【００４２】
次に、本発明の第７の実施の形態を説明する。図７は本発明の第７の実施の形態を示す構成図である。図７において、主蒸気隔離弁６の２次側圧力は２次側圧力検出器２７で検出し、２次側圧力変化率判定手段２９は、２次側圧力検出器２７からの信号に基づいて主蒸気隔離弁６の２次側圧力の変化率が所定値より大であるか否かを判定する。そして、制御手段２６は、２次側圧力変化率判定手段２９により主蒸気隔離弁６の２次側圧力変化率が所定値より大であると判定されたときは加熱蒸気元弁１４又は加熱蒸気調節弁１５の全閉操作を行う。
【００４３】
すなわち、湿分分離加熱器１０は主蒸気を加熱源とする加熱器１８を有しており、この加熱器１８に主蒸気を供給する加熱蒸気管１１には、加熱蒸気元弁１４と加熱蒸気圧力調節弁１５とが設けられている。そこで、主蒸気隔離弁６の２次側圧力変化率が所定値より大であると判定されたときは加熱蒸気元弁１４の全閉操作を行う。たとえば、加熱蒸気元弁１４を１分以内に全閉する。これにより、加熱蒸気元弁１４の２次側圧力の急減を防ぐことが可能となり、湿分分離加熱器１０に過度の熱応力を発生させず湿分分離加熱器１０の健全性を維持することができる。また、加熱蒸気圧力調節弁１５を１分以内に全閉するようにしても良い。
【００４４】
次に、本発明の第８の実施の形態を説明する。図８は本発明の第８の実施の形態を示す構成図である。図８において、主蒸気隔離弁６の１次側圧力を１次側圧力検出器３０で検出し、主蒸気隔離弁６の２次側圧力を２次側圧力検出器２７で検出し、圧力偏差判定手段３１は、１次側圧力検出器３０及び２次側圧力検出器２７からの信号に基づいて主蒸気隔離弁６の１次側圧力と２次側圧力との圧力偏差が所定値より大であるか否かを判定する。そして、制御手段２６は、圧力偏差判定手段３１により主蒸気隔離弁６の１次側圧力と２次側圧力との圧力偏差が所定値より大であると判定されたときは加熱蒸気元弁１４又は加熱蒸気調節弁１５の全閉操作を行う。
【００４５】
すなわち、湿分分離加熱器１０は主蒸気を加熱源とする加熱器１８を有しており、この加熱器１８に主蒸気を供給する加熱蒸気管１１には、加熱蒸気元弁１４と加熱蒸気圧力調節弁１５とが設けられている。そこで、主蒸気隔離弁６の１次側圧力と２次側圧力との圧力偏差が所定値より大であると判定されたときは加熱蒸気元弁１４の全閉操作を行う。たとえば、加熱蒸気元弁１４を１分以内に全閉する。これにより、加熱蒸気元弁１４の２次側圧力の急減を防ぐことが可能となり、湿分分離加熱器１０に過度の熱応力を発生させず湿分分離加熱器１０の健全性を維持することができる。また、加熱蒸気圧力調節弁１５を１分以内に全閉するようにしても良い。
【００４６】
次に、図９は、本発明の第９の実施の形態における系統構成の説明図である。図９において、主蒸気ヘッダ７には原子炉１から主蒸気が供給される。主蒸気ヘッダ７からの主蒸気は、湿分分離加熱器１０の加熱器１８に供給されることになるが、その加熱蒸気管１１に加熱蒸気元弁１４及び加熱蒸気圧力調整弁１５に加えて、加熱蒸気元弁１４の上流側に遮断弁２１を設けている。
【００４７】
すなわち、主蒸気を加熱源とする加熱器１８を有した湿分分離加熱器１０に主蒸気を供給する加熱蒸気管１１には、加熱蒸気元弁１４と加熱蒸気圧力調節弁１５が設けられているが、さらに遮断弁２１を追加して設ける。そして、第５の実施の形態乃至第８の実施の形態における加熱蒸気元弁１４及び加熱蒸気圧力調整弁１５を全閉にする代わりに、この遮断弁２１を１分以内で全閉する。これにより、遮断弁２１の２次側の圧力の急減を防止することが可能となり、湿分分離加熱器１０に過度の熱応力を発生させず、湿分分離加熱器１０の健全性を維持することができる。
【００４８】
次に、図１０は、本発明の第１０の実施の形態における系統構成の説明図である。図９に示した第９の実施の形態における系統構成の遮断弁２１に代えて、逆止弁２２を設けたものである。この逆止弁２２は湿分分離加熱器１０に供給する主蒸気の原子炉側への逆流を阻止するものであり、主蒸気隔離弁６の２次側圧力が低下した状態のときに、湿分分離加熱器１０の器内圧力の低下を防止する。
【００４９】
すなわち、加熱蒸気管１１の途中に逆止弁２２を設置し、この逆止弁２２の１次側圧力と２次側圧力が逆転した場合であっても、逆止弁２２の２次側の圧力が急減することを防止することが可能となり、湿分分離加熱器に過度の熱応力を発生させず、湿分分離加熱器の健全性を維持することができる。また、逆止弁２２には通常の起動停止時の圧力調節で円滑に行えるように任意に強制開または強制閉の操作が可能な設備としてもよい。
【００５０】
【発明の効果】
以上述べたように、本発明によれば、主蒸気隔離弁の全閉事象が発生し、湿分分離加熱器の主蒸気を加熱源とする加熱器の器内圧力が急減しようとするときは、タービンバイパス弁の全閉操作とタービントリップ操作を行うので、加熱器の器内圧力の圧力変化量を抑えることができる。また、湿分分離加熱器に主蒸気を供給する加熱蒸気管の途中に設置した弁により加熱器の器内圧力の圧力変化量を抑えることができる。したがって、湿分分離加熱器に過度の熱応力を発生させずに湿分分離加熱器の健全性を維持でき、プラントの信頼性を向上させることができる。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態を示す構成図。
【図２】本発明の第２の実施の形態を示す構成図。
【図３】本発明の第３の実施の形態を示す構成図。
【図４】本発明の第４の実施の形態を示す構成図。
【図５】本発明の第５の実施の形態を示す構成図。
【図６】本発明の第６の実施の形態を示す構成図。
【図７】本発明の第７の実施の形態を示す構成図。
【図８】本発明の第８の実施の形態を示す構成図。
【図９】本発明の第９の実施の形態における系統構成の説明図。
【図１０】本発明の第１０の実施の形態における系統構成の説明図。
【図１１】原子炉圧力制御を行う原子力発電所におけるタービン設備の概略図。
【符号の説明】
１原子炉
２主蒸気管
３高圧タービン
４主蒸気止め弁
５蒸気加減弁
６主蒸気隔離弁
７主蒸気ヘッダ
８復水器
９タービンバイパス管
１０湿分分離加熱器
１１加熱蒸気管
１２原子炉圧力検出器
１３タービンバイパス弁
１４加熱蒸気元弁
１５加熱蒸気圧力調整弁
１６低圧タービン
１７クロスアラウンド管
１８加熱器
１９給水加熱器
２０昇圧ポンプ
２１遮断弁
２２逆止弁
２３タービンバイパス弁制御装置
２４弁状態検出装置
２５弁状態判定手段
２６制御手段
２７２次側圧力検出手段
２８２次側圧力判定手段
２９圧力変化率判定手段
３０１次側圧力検出器
３１圧力偏差判定手段[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a moisture separator heater protection device for a nuclear power plant for protecting a moisture separator heater in a nuclear power plant that performs reactor pressure control.
[0002]
[Prior art]
FIG. 11 is a schematic diagram of turbine equipment in a nuclear power plant that performs reactor pressure control. The steam generated in the nuclear reactor 1 reaches the steam stop valve 4 and the steam control valve 5 through the main steam pipe 2 and is guided to the high pressure turbine 3 to drive the high pressure turbine 3.
[0003]
On the other hand, in the middle of the main steam pipe 2, there are a main steam isolation valve 6 and a main steam header 7. From the main steam header 7, a turbine bypass pipe 9 that leads the main steam directly to the condenser 8 and moisture separation are provided. A heating steam pipe 11 for supplying main steam to the heater 10 is branched. A turbine bypass valve 13 is provided in the turbine bypass pipe 9, and the turbine bypass valve 13 is controlled by a turbine bypass valve control device 23 based on the reactor pressure from the reactor pressure detector 12. In addition, a heating steam source valve 14 that closes the inflow of heating steam to the moisture separation heater 10 and a heating steam pressure control valve 15 are installed in the heating steam pipe 11 that supplies main steam to the moisture separation heater 10. Has been.
[0004]
The high-pressure turbine 3 and the low-pressure turbine 16 are connected to each other by a cross-around pipe 17, and a moisture separation heater 10 including a heater 18 that uses main steam as a heating source is installed in the middle of the cross-around pipe 17. Yes. That is, the steam that has finished work in the high-pressure turbine 3 is guided to the low-pressure turbine 16 through the moisture separator and heater 10 to drive the low-pressure turbine 16. The exhaust steam that has finished its work in the low-pressure turbine 16 is condensed in the condenser 8, and then heated and boosted via the booster pump 20 and the feed water heater 19 and returned to the nuclear reactor 1.
[0005]
In a turbine facility of a nuclear power plant that performs such reactor pressure control, when the main steam isolation valve 6 is fully closed, the reactor pressure of the reactor 1 increases and the plant is stopped. In the process, the turbine bypass valve control device 23 that has received a signal from the reactor pressure detector 12 opens the turbine bypass valve 13. That is, when the main steam isolation valve 6 is closed, the reactor pressure starts to increase. At this time, the turbine bypass valve 13 is opened to suppress the increase in the reactor pressure, and the main steam header 7 is connected to the condenser 8. Steam is discharged.
[0006]
[Problems to be solved by the invention]
However, due to the closing of the main steam isolation valve 6 installed in the middle of the main steam pipe 2 from the reactor 1 to the turbine bypass valve 13, the steam in the reactor 1 cannot be guided to the condenser 8. As a result, the opening of the turbine bypass valve 13 causes the steam pressure on the secondary side of the main steam isolation valve 6 to rapidly decrease.
[0007]
As the secondary pressure of the main steam isolation valve 6 decreases, the internal pressure of the heater 18 decreases, and the steam temperature of the heater 18 decreases according to the saturation temperature of the internal pressure. For this reason, the internal temperature of the heater 18 also falls. Therefore, a sudden change in the internal pressure causes an abrupt change in the temperature distribution in the internal storage, which may cause excessive thermal stress, and the soundness of the moisture separation heater 10 cannot be maintained. There was a problem.
[0008]
It is an object of the present invention to prevent moisture from being separated and to maintain its soundness in a moisture separation heater even if the main steam isolation valve is closed. Is to provide a protective device.
[0009]
[Means for Solving the Problems]
The invention of claim 1 protects a moisture separation heater that removes moisture contained in steam that has finished work in a main turbine of a nuclear power plant by supplying main steam from a nuclear reactor. Is a moisture separator / heater protection device for nuclear power plants in Japan, which detects the valve state of the main steam isolation valve provided at the reactor outlet, and the main steam based on the signal from the valve state detection device When the main steam isolation valve is determined to be in a valve state other than the fully open state by the valve state determining unit for determining the valve state of the isolation valve and the turbine state determining unit, the turbine bypass valve is fully closed and the turbine trip operation is performed. And a control means for performing the above.
[0010]
In the first aspect of the invention, the valve state of the main steam isolation valve is detected by the valve state detection device, and the valve state determination means determines the valve state of the main steam isolation valve based on the signal from the valve state detection device. When the valve state determining unit determines that the main steam isolation valve is in a valve state other than the fully open state, the control unit performs the turbine trip operation while performing the fully closing operation of the turbine bypass valve.
[0011]
The invention of claim 2 protects a moisture separation heater that removes moisture contained in steam that has finished work at the main turbine of a nuclear power plant by supplying main steam from a nuclear reactor. This is a moisture separator heater protection device for a nuclear power plant, and a secondary pressure detector for detecting the secondary pressure of the main steam isolation valve provided at the reactor outlet, and a signal from the secondary pressure detector The secondary pressure of the main steam isolation valve is determined by the secondary pressure determination means for determining whether or not the secondary pressure of the main steam isolation valve is below a predetermined value based on the When it is determined that the value is equal to or less than the value, the control unit performs a full trip operation of the turbine bypass valve and a turbine trip operation.
[0012]
In the invention of claim 2, the secondary side pressure of the main steam isolation valve is detected by the secondary side pressure detector, and the secondary side pressure determination means is based on the signal from the secondary side pressure detector. It is determined whether or not the secondary pressure of the valve is equal to or less than a predetermined value. When the secondary pressure determining means determines that the secondary pressure of the main steam isolation valve is equal to or less than a predetermined value, the control means performs the turbine trip operation while fully closing the turbine bypass valve.
[0013]
According to a third aspect of the present invention, there is provided a moisture separator for protecting a moisture separator heater that removes moisture contained in steam that has finished work in a main turbine of a nuclear power plant by supplying main steam from a nuclear reactor. This is a moisture separator heater protection device for a nuclear power plant, and a secondary pressure detector for detecting the secondary pressure of the main steam isolation valve provided at the reactor outlet, and a signal from the secondary pressure detector The secondary steam pressure change rate determination means for determining whether or not the change rate of the secondary pressure of the primary steam isolation valve is greater than a predetermined value based on the main steam isolation by the secondary pressure change rate determination means and the secondary pressure change rate determination means When it is determined that the secondary pressure change rate of the valve is larger than a predetermined value, a control means for performing a turbine trip operation as well as a fully closing operation of the turbine bypass valve is provided.
[0014]
In the invention of claim 3, the secondary side pressure of the main steam isolation valve is detected by the secondary side pressure detector, and the secondary side pressure change rate judging means is based on the signal from the secondary side pressure detector. It is determined whether the rate of change of the secondary pressure of the steam isolation valve is greater than a predetermined value. When the secondary pressure change rate determining means determines that the secondary pressure change rate of the main steam isolation valve is larger than a predetermined value, the control means performs the fully closing operation of the turbine bypass valve and the turbine. Perform a trip operation.
[0015]
According to a fourth aspect of the present invention, there is provided a moisture separator / heater for protecting a moisture separation heater that removes moisture contained in steam that has finished work in a main turbine of a nuclear power plant by supplying main steam from a nuclear reactor. It is a moisture separator heater protection device for nuclear power plants, and a primary pressure detector for detecting the primary pressure of the main steam isolation valve provided at the reactor outlet, and a secondary pressure of the main steam isolation valve The pressure deviation between the primary side pressure and the secondary side pressure of the main steam isolation valve is predetermined based on a signal from the secondary side pressure detector for detecting the pressure and a signal from the primary side pressure detector and the secondary side pressure detector. Pressure deviation determining means for determining whether or not the pressure is larger than the value, and the pressure deviation determining means determines that the pressure deviation between the primary side pressure and the secondary side pressure of the main steam isolation valve is greater than a predetermined value. When the control is performed, the turbine bypass valve is fully closed and the turbine trip operation is performed. It is those with a door.
[0016]
In the invention of claim 4, the primary side pressure of the main steam isolation valve is detected by the primary side pressure detector, the secondary side pressure of the main steam isolation valve is detected by the secondary side pressure detector, and the pressure deviation is determined. The means determines whether or not the pressure deviation between the primary side pressure and the secondary side pressure of the main steam isolation valve is larger than a predetermined value based on signals from the primary side pressure detector and the secondary side pressure detector. Determine. When the pressure deviation determining means determines that the pressure deviation between the primary side pressure and the secondary side pressure of the main steam isolation valve is greater than a predetermined value, the control means performs the fully closing operation of the turbine bypass valve. And a turbine trip operation.
[0017]
According to the fifth aspect of the present invention, the main steam from the nuclear reactor is guided to the moisture separator / heater via the heating steam main valve and the heating steam pressure regulating valve, and the moisture contained in the steam finished work in the main turbine is humidified. A moisture separation heater protection device for nuclear power plants that is removed by a separation heater, a valve state detection device that detects the valve state of the main steam isolation valve provided at the reactor outlet, and a valve state detection A valve state determining means for determining the valve state of the main steam isolation valve based on a signal from the apparatus, and a steam source valve when the valve state determining means determines that the main steam isolation valve is in a valve state other than fully open Or a control means for fully closing the heating steam control valve is provided.
[0018]
In the invention of claim 5, the valve state of the main steam isolation valve is detected by the valve state detection device, and the valve state determination means determines the valve state of the main steam isolation valve based on the signal from the valve state detection device. When the valve state determining unit determines that the main steam isolation valve is in a valve state other than the fully open state, the control unit performs a fully closing operation of the heating steam source valve or the heating steam control valve.
[0019]
According to the sixth aspect of the present invention, the main steam from the nuclear reactor is led to the moisture separation heater through the heating steam main valve and the heating steam pressure regulating valve, and the moisture contained in the steam finished work in the main turbine is humidified. A moisture separator heater protection device for a nuclear power plant that is removed by a separator heater, a secondary pressure detector for detecting a secondary pressure of a main steam isolation valve provided at a reactor outlet; Based on the signal from the secondary pressure detector, the main pressure isolation means for determining whether or not the secondary pressure of the main steam isolation valve is equal to or lower than a predetermined value and the secondary pressure determination means When it is determined that the secondary pressure of the steam isolation valve is equal to or lower than a predetermined value, a control means for performing a fully closing operation of the heating steam source valve or the heating steam control valve is provided.
[0020]
In the invention of claim 6, the secondary side pressure of the main steam isolation valve is detected by the secondary side pressure detector, and the secondary side pressure determination means is based on the signal from the secondary side pressure detector. It is determined whether or not the secondary pressure of the valve is equal to or less than a predetermined value. When the secondary pressure determining means determines that the secondary pressure of the main steam isolation valve is equal to or less than a predetermined value, the control means performs a fully closing operation of the heating steam source valve or the heating steam control valve.
[0021]
According to the seventh aspect of the present invention, the main steam from the nuclear reactor is guided to the moisture separator / heater via the heating steam main valve and the heating steam pressure regulating valve, and the moisture contained in the steam finished work in the main turbine is humidified. A moisture separator heater protection device for a nuclear power plant that is removed by a separator heater, a secondary pressure detector for detecting a secondary pressure of a main steam isolation valve provided at a reactor outlet; A secondary-side pressure change rate determining means for determining whether or not the change rate of the secondary-side pressure of the main steam isolation valve is greater than a predetermined value based on a signal from the secondary-side pressure detector; Control means for fully closing the heating steam source valve or the heating steam control valve when the secondary pressure change rate of the main steam isolation valve is determined to be greater than a predetermined value by the side pressure change rate determination means; It is provided.
[0022]
In the invention of claim 7, the secondary side pressure of the main steam isolation valve is detected by the secondary side pressure detector, and the secondary side pressure change rate judging means is based on the signal from the secondary side pressure detector. It is determined whether the rate of change of the secondary pressure of the steam isolation valve is greater than a predetermined value. When the secondary pressure change rate determining means determines that the secondary pressure change rate of the main steam isolation valve is greater than a predetermined value, the control means determines that all of the heating steam source valve or the heating steam control valve is Perform the closing operation.
[0023]
According to the eighth aspect of the invention, the main steam from the nuclear reactor is guided to the moisture separation heater through the heating steam main valve and the heating steam pressure regulating valve, and the moisture contained in the steam that has finished work in the main turbine is humidified. A moisture separator heater protection device for a nuclear power plant that is removed by a separator heater, and a primary pressure detector for detecting a primary pressure of a main steam isolation valve provided at a reactor outlet; A secondary side pressure detector for detecting a secondary side pressure of the main steam isolation valve, and a primary side pressure of the main steam isolation valve based on signals from the primary side pressure detector and the secondary side pressure detector; Pressure deviation determination means for determining whether or not the pressure deviation from the secondary side pressure is greater than a predetermined value, and the pressure deviation between the primary side pressure and the secondary side pressure of the main steam isolation valve by the pressure deviation judgment means Is determined to be larger than the predetermined value, the heating steam source valve or heating steam control valve is fully closed. It is obtained by a control means.
[0024]
According to the eighth aspect of the invention, the primary pressure of the main steam isolation valve is detected by the primary pressure detector, the secondary pressure of the main steam isolation valve is detected by the secondary pressure detector, and the pressure deviation is determined. The means determines whether or not the pressure deviation between the primary side pressure and the secondary side pressure of the main steam isolation valve is larger than a predetermined value based on signals from the primary side pressure detector and the secondary side pressure detector. Determine. When the pressure deviation determining means determines that the pressure deviation between the primary side pressure and the secondary side pressure of the main steam isolation valve is larger than a predetermined value, the control means determines the heating steam source valve or the heating steam adjustment. Fully close the valve.
[0027]
Claim 9 According to the invention of claim 5, in the invention of claims 5 to 8, a shutoff valve for shutting off the main steam supplied to the moisture separation heater is provided upstream of the heating steam source valve, and the control means is the heating steam source valve. Alternatively, the shut-off valve is fully closed instead of the heating steam control valve.
[0028]
Claim 9 In this invention, when the secondary side pressure of the main steam isolation valve is lowered, the shut-off valve is fully closed to prevent the internal pressure of the moisture separation heater from being lowered.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below. FIG. 1 is a block diagram showing a first embodiment of the present invention. In FIG. 1, the valve state detection device 24 detects the valve state of the main steam isolation valve 6, and the valve state of the main steam isolation valve detected by the valve state detection device 24 is sent to the valve state determination means 25. Entered. Based on the input valve state, the valve state determination means 25 determines whether or not the main steam isolation valve 6 is in a state other than fully open. If the valve state of the main steam isolation valve 6 is in a state other than fully open, the control is performed. The logic signal “1” is output to the means 26. When the control means 26 receives a signal indicating that the main steam isolation valve 6 is not fully opened, the control means 26 performs a fully closing operation of the turbine bypass valve 13 and a turbine trip operation.
[0030]
That is, when a fully-closed event occurs in the main steam isolation valve 6, the fully-closed operation to the turbine bypass valve 13 that operates according to the reactor pressure input signal, and the main steam stop valve 4 by the turbine trip operation. The fully closed operation prevents a sudden decrease in the secondary pressure of the main steam isolation valve 6. Thereby, the soundness of the moisture separation heater 10 can be maintained without generating excessive thermal stress in the heater 18 using the main steam of the moisture separation heater 10 as a heating source.
[0031]
In the above description, the valve state determination means 25 determines whether or not the main steam isolation valve 6 is in a state other than the fully open state, and when the main steam isolation valve 6 is in a state other than the fully open state, the control means 26 determines the turbine bypass valve 13. However, when the valve opening of the main steam isolation valve 6 is fully closed, such operation may be performed.
[0032]
Next, a second embodiment of the present invention will be described. FIG. 2 is a block diagram showing a second embodiment of the present invention. In FIG. 2, the secondary side pressure detector 27 detects the secondary side pressure of the main steam isolation valve 6, and the secondary side pressure of the main steam isolation valve detected by the secondary side pressure detector 27. Is input to the secondary pressure determination means 28. The secondary pressure determination means 28 determines whether the secondary pressure of the main steam isolation valve 6 is equal to or lower than a predetermined value based on the signal from the secondary pressure detector 27. When the secondary side pressure determination unit 28 determines that the secondary side pressure of the main steam isolation valve 6 is equal to or lower than a predetermined value, the control unit 26 performs the fully closing operation of the turbine bypass valve 13 and the turbine. Perform a trip operation.
[0033]
That is, when the secondary pressure of the main steam isolation valve 6 falls below a predetermined value, the turbine bypass valve 13 is fully closed and the turbine trip is performed. As a result, it is possible to prevent a sudden decrease in the secondary pressure of the main steam isolation valve 6, and moisture without causing excessive thermal stress in the heater 18 using the main steam of the moisture separation heater 10 as a heating source. The soundness of the separation heater can be maintained.
[0034]
Next, a third embodiment of the present invention will be described. FIG. 3 is a block diagram showing a third embodiment of the present invention. In FIG. 3, the secondary side pressure detector 27 detects the secondary side pressure of the main steam isolation valve 6, and the secondary side pressure of the main steam isolation valve detected by the secondary side pressure detector 27. Is input to the pressure change rate determination means 29. The pressure change rate determination means 29 obtains the change rate of the secondary side pressure of the main steam isolation valve 6 based on the signal from the secondary side pressure detector 27, and whether or not the pressure change rate is greater than a predetermined value. Determine whether. When the pressure change rate determination means 29 determines that the pressure change rate of the main steam isolation valve 6 is greater than a predetermined value, the control means 26 performs a fully-close operation of the turbine bypass valve 13 and a turbine trip. Perform the operation.
[0035]
That is, when the secondary side pressure change rate of the main steam isolation valve 6 exceeds a predetermined value, the turbine bypass valve 13 is fully closed and the turbine trip operation is performed. This makes it possible to prevent a sudden decrease in the secondary side pressure of the main steam isolation valve 6, prevents the moisture separation heater 10 from being generated due to excessive thermal stress, and the soundness of the moisture separation heater 10. Can be maintained.
[0036]
Next, a fourth embodiment of the present invention will be described. FIG. 4 is a block diagram showing a fourth embodiment of the present invention. In FIG. 4, the primary side pressure of the main steam isolation valve 6 is detected by the primary side pressure detector 30, and the secondary side pressure of the main steam isolation valve 6 is detected by the secondary side pressure detector 27. . The primary side pressure of the main steam isolation valve 6 detected by the primary side pressure detector 30 and the secondary side pressure of the main steam isolation valve 6 detected by the secondary side pressure detector 27 are the pressure deviation determining means 31. Is input. Based on the signals from the primary pressure detector 30 and the secondary pressure detector 27, the pressure deviation determination means 31 has a predetermined pressure deviation between the primary pressure and the secondary pressure of the main steam isolation valve 6. It is determined whether or not it is larger than the value. When the pressure deviation determining means 31 determines that the pressure deviation between the primary side pressure and the secondary side pressure of the main steam isolation valve 6 is greater than a predetermined value, the control means 26 determines that all of the turbine bypass valves are Perform the closing operation and the turbine trip operation.
[0037]
That is, the turbine bypass valve 13 is fully closed and the turbine trip is performed based on the pressure deviation between the secondary side pressure of the main steam isolation valve 6 and the reactor pressure (primary side pressure of the main steam isolation valve 6). This makes it possible to prevent a sudden decrease in the secondary side pressure of the main steam isolation valve 6 and maintain the soundness of the moisture separation heater 10 without generating excessive thermal stress in the moisture separation heater 10. be able to.
[0038]
Next, a fifth embodiment of the present invention will be described. FIG. 5 is a block diagram showing a fifth embodiment of the present invention. In FIG. 5, the valve state of the main steam isolation valve 6 is detected by the valve state detection device 24, and the valve state determination means 25 determines the valve state of the main steam isolation valve 6 based on the signal from the valve state detection device 24. To do. When the valve state determination unit 25 determines that the main steam isolation valve 6 is in a valve state other than the fully open state, the control unit 26 performs the fully closing operation of the heating steam source valve 14 or the heating steam control valve 15.
[0039]
That is, the moisture separation heater 10 has a heater 18 that uses main steam as a heating source. A heating steam source valve 14 and heating steam are provided in a heating steam pipe 11 that supplies main steam to the heater 18. A pressure control valve 15 is provided. Therefore, when it is determined that the main steam isolation valve 6 is in a valve state other than the fully open state, the heating steam source valve 14 is fully closed. For example, the heating steam source valve 14 is fully closed within 1 minute. This makes it possible to prevent a sudden decrease in the secondary pressure of the heating steam source valve 14, and maintain the soundness of the moisture separation heater 10 without generating excessive thermal stress in the moisture separation heater 10. Can do. Moreover, you may make it fully close the heating steam pressure control valve 15 within 1 minute.
[0040]
Next, a sixth embodiment of the present invention will be described. FIG. 6 is a block diagram showing a sixth embodiment of the present invention. In FIG. 6, the secondary side pressure of the main steam isolation valve 6 is detected by the secondary side pressure detector 27, and the secondary side pressure determination means 28 is based on the signal from the secondary side pressure detector 27. It is determined whether or not the secondary pressure of the valve 6 is not more than a predetermined value. When the secondary side pressure determination unit 28 determines that the secondary side pressure of the main steam isolation valve 6 is equal to or less than a predetermined value, the control unit 26 controls all of the heating steam source valve 14 or the heating steam control valve 15. Perform the closing operation.
[0041]
That is, the moisture separation heater 10 has a heater 18 that uses main steam as a heating source. A heating steam source valve 14 and heating steam are provided in a heating steam pipe 11 that supplies main steam to the heater 18. A pressure control valve 15 is provided. Therefore, when it is determined that the secondary side pressure of the main steam isolation valve 6 is not more than a predetermined value, the heating steam source valve 14 is fully closed. For example, the heating steam source valve 14 is fully closed within 1 minute. This makes it possible to prevent a sudden decrease in the secondary pressure of the heating steam source valve 14, and maintain the soundness of the moisture separation heater 10 without generating excessive thermal stress in the moisture separation heater 10. Can do. Moreover, you may make it fully close the heating steam pressure control valve 15 within 1 minute.
[0042]
Next, a seventh embodiment of the present invention will be described. FIG. 7 is a block diagram showing a seventh embodiment of the present invention. In FIG. 7, the secondary side pressure of the main steam isolation valve 6 is detected by the secondary side pressure detector 27, and the secondary side pressure change rate determination means 29 is based on the signal from the secondary side pressure detector 27. It is determined whether or not the rate of change of the secondary side pressure of the main steam isolation valve 6 is greater than a predetermined value. When the secondary side pressure change rate determining unit 29 determines that the secondary side pressure change rate of the main steam isolation valve 6 is greater than a predetermined value, the control unit 26 or the heated steam source valve 14 or the heated steam is used. The control valve 15 is fully closed.
[0043]
That is, the moisture separation heater 10 has a heater 18 that uses main steam as a heating source. A heating steam source valve 14 and heating steam are provided in a heating steam pipe 11 that supplies main steam to the heater 18. A pressure control valve 15 is provided. Therefore, when it is determined that the secondary pressure change rate of the main steam isolation valve 6 is larger than a predetermined value, the heating steam source valve 14 is fully closed. For example, the heating steam source valve 14 is fully closed within 1 minute. This makes it possible to prevent a sudden decrease in the secondary pressure of the heating steam source valve 14 and maintain the soundness of the moisture separation heater 10 without generating excessive thermal stress in the moisture separation heater 10. Can do. Moreover, you may make it fully close the heating steam pressure control valve 15 within 1 minute.
[0044]
Next, an eighth embodiment of the present invention will be described. FIG. 8 is a block diagram showing an eighth embodiment of the present invention. In FIG. 8, the primary pressure of the main steam isolation valve 6 is detected by the primary pressure detector 30, the secondary pressure of the main steam isolation valve 6 is detected by the secondary pressure detector 27, and the pressure deviation is detected. Based on the signals from the primary side pressure detector 30 and the secondary side pressure detector 27, the judging means 31 has a pressure deviation between the primary side pressure and the secondary side pressure of the main steam isolation valve 6 larger than a predetermined value. It is determined whether or not. When the pressure deviation determining means 31 determines that the pressure deviation between the primary side pressure and the secondary side pressure of the main steam isolation valve 6 is greater than a predetermined value, the control means 26 determines the heating steam source valve 14. Alternatively, the heating steam control valve 15 is fully closed.
[0045]
That is, the moisture separation heater 10 has a heater 18 that uses main steam as a heating source. A heating steam source valve 14 and heating steam are provided in a heating steam pipe 11 that supplies main steam to the heater 18. A pressure control valve 15 is provided. Therefore, when it is determined that the pressure deviation between the primary side pressure and the secondary side pressure of the main steam isolation valve 6 is larger than a predetermined value, the heating steam source valve 14 is fully closed. For example, the heating steam source valve 14 is fully closed within 1 minute. This makes it possible to prevent a sudden decrease in the secondary pressure of the heating steam source valve 14 and maintain the soundness of the moisture separation heater 10 without generating excessive thermal stress in the moisture separation heater 10. Can do. Moreover, you may make it fully close the heating steam pressure control valve 15 within 1 minute.
[0046]
Next, FIG. 9 is an explanatory diagram of a system configuration in the ninth embodiment of the present invention. In FIG. 9, main steam is supplied from the reactor 1 to the main steam header 7. The main steam from the main steam header 7 is supplied to the heater 18 of the moisture separation heater 10, and is added to the heating steam pipe 11 in addition to the heating steam main valve 14 and the heating steam pressure adjustment valve 15. A shut-off valve 21 is provided upstream of the heating steam source valve 14.
[0047]
That is, a heating steam source valve 14 and a heating steam pressure control valve 15 are provided in the heating steam pipe 11 for supplying the main steam to the moisture separation heater 10 having the heater 18 using the main steam as a heating source. However, a shutoff valve 21 is additionally provided. Then, instead of fully closing the heating steam source valve 14 and the heating steam pressure adjusting valve 15 in the fifth to eighth embodiments, the shutoff valve 21 is fully closed within one minute. As a result, it is possible to prevent a sudden decrease in the pressure on the secondary side of the shut-off valve 21, so that excessive thermal stress is not generated in the moisture separation heater 10 and the soundness of the moisture separation heater 10 is maintained. be able to.
[0048]
Next, FIG. 10 is an explanatory diagram of a system configuration in the tenth embodiment of the present invention. A check valve 22 is provided in place of the shutoff valve 21 of the system configuration in the ninth embodiment shown in FIG. This check valve 22 prevents the main steam supplied to the moisture separator / heater 10 from flowing back to the reactor side. When the secondary pressure of the main steam isolation valve 6 is lowered, the check valve 22 A drop in the internal pressure of the separation heater 10 is prevented.
[0049]
That is, even if the check valve 22 is installed in the middle of the heating steam pipe 11 and the primary side pressure and the secondary side pressure of the check valve 22 are reversed, the secondary side of the check valve 22 It is possible to prevent the pressure from rapidly decreasing, and it is possible to maintain the soundness of the moisture separation heater without generating excessive thermal stress in the moisture separation heater. Further, the check valve 22 may be a facility that can be arbitrarily forcibly opened or forcibly closed so that it can be smoothly adjusted by adjusting the pressure at the time of normal starting and stopping.
[0050]
【The invention's effect】
As described above, according to the present invention, when the fully closed event of the main steam isolation valve occurs and the internal pressure of the heater using the main steam of the moisture separation heater as a heating source is about to suddenly decrease, Since the turbine bypass valve is fully closed and the turbine trip is performed, the amount of change in the internal pressure of the heater can be suppressed. Moreover, the amount of pressure change of the internal pressure of the heater can be suppressed by a valve installed in the middle of the heating steam pipe for supplying the main steam to the moisture separation heater. Therefore, the soundness of the moisture separation heater can be maintained without generating excessive thermal stress in the moisture separation heater, and the reliability of the plant can be improved.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a first embodiment of the present invention.
FIG. 2 is a configuration diagram showing a second embodiment of the present invention.
FIG. 3 is a configuration diagram showing a third embodiment of the present invention.
FIG. 4 is a configuration diagram showing a fourth embodiment of the present invention.
FIG. 5 is a configuration diagram showing a fifth embodiment of the present invention.
FIG. 6 is a configuration diagram showing a sixth embodiment of the present invention.
FIG. 7 is a configuration diagram showing a seventh embodiment of the present invention.
FIG. 8 is a configuration diagram showing an eighth embodiment of the present invention.
FIG. 9 is an explanatory diagram of a system configuration according to a ninth embodiment of the present invention.
FIG. 10 is an explanatory diagram of a system configuration in the tenth embodiment of the present invention.
FIG. 11 is a schematic diagram of turbine equipment in a nuclear power plant that performs reactor pressure control.
[Explanation of symbols]
1 Reactor
2 Main steam pipe
3 High-pressure turbine
4 Main steam stop valve
5 Steam control valve
6 Main steam isolation valve
7 Main steam header
8 Condenser
9 Turbine bypass pipe
10 Moisture separation heater
11 Heated steam pipe
12 Reactor pressure detector
13 Turbine bypass valve
14 Heating steam valve
15 Heating steam pressure adjustment valve
16 Low pressure turbine
17 Cross-around tube
18 Heater
19 Water heater
20 Booster pump
21 Shut-off valve
22 Check valve
23 Turbine bypass valve control device
24 Valve state detection device
25 Valve state determination means
26 Control means
27 Secondary pressure detection means
28 Secondary pressure judgment means
29 Pressure change rate determination means
30 Primary pressure detector
31 Pressure deviation judging means

Claims

原子力発電所の主タービンで仕事を終えた蒸気に含まれる湿分を原子炉からの主蒸気を供給して除去するようにした湿分分離加熱器を保護するための原子力発電所の湿分分離加熱器保護装置において、前記原子炉出口に設けられた主蒸気隔離弁の弁状態を検出する弁状態検出装置と、前記弁状態検出装置からの信号に基づいて前記主蒸気隔離弁の弁状態を判定する弁状態判定手段と、前記弁状態判定手段により前記主蒸気隔離弁が全開以外の弁状態であると判定されたときはタービンバイパス弁の全閉操作を行うと共にタービントリップ操作を行う制御手段とを備えたことを特徴とする原子力発電所の湿分分離加熱器保護装置。 Moisture separation in nuclear power plants to protect moisture separator heaters that supply main steam from the reactor to remove moisture contained in steam that has finished work at the main turbine of the nuclear power plant In the heater protection device, a valve state detection device for detecting a valve state of a main steam isolation valve provided at the reactor outlet, and a valve state of the main steam isolation valve based on a signal from the valve state detection device A valve state determining unit for determining, and a control unit for performing a turbine trip operation while performing a fully closed operation of the turbine bypass valve when the valve state determining unit determines that the main steam isolation valve is in a valve state other than a fully open state A moisture separator heater protection device for a nuclear power plant.

原子力発電所の主タービンで仕事を終えた蒸気に含まれる湿分を原子炉からの主蒸気を供給して除去するようにした湿分分離加熱器を保護するための原子力発電所の湿分分離加熱器保護装置において、前記原子炉出口に設けられた主蒸気隔離弁の２次側圧力を検出する２次側圧力検出器と、前記２次側圧力検出器からの信号に基づいて前記主蒸気隔離弁の２次側圧力が所定値以下であるか否かを判定する２次側圧力判定手段と、前記２次側圧力判定手段により前記主蒸気隔離弁の２次側圧力が所定値以下であると判定されたときはタービンバイパス弁の全閉操作を行うと共にタービントリップ操作を行う制御手段とを備えたことを特徴とする原子力発電所の湿分分離加熱器保護装置。 Moisture separation in nuclear power plants to protect moisture separator heaters that supply main steam from the reactor to remove moisture contained in steam that has finished work at the main turbine of the nuclear power plant In the heater protection device, a secondary pressure detector for detecting a secondary pressure of a main steam isolation valve provided at the reactor outlet, and the main steam based on a signal from the secondary pressure detector A secondary-side pressure determining means for determining whether or not the secondary-side pressure of the isolation valve is less than or equal to a predetermined value; and the secondary-side pressure of the main steam isolation valve is less than or equal to a predetermined value by the secondary-side pressure determining means A moisture separator heater protection device for a nuclear power plant, comprising: a control means for performing a turbine trip operation while performing a fully-closed operation of the turbine bypass valve when it is determined that the turbine bypass valve is present.

原子力発電所の主タービンで仕事を終えた蒸気に含まれる湿分を原子炉からの主蒸気を供給して除去するようにした湿分分離加熱器を保護するための原子力発電所の湿分分離加熱器保護装置において、前記原子炉出口に設けられた主蒸気隔離弁の２次側圧力を検出する２次側圧力検出器と、前記２次側圧力検出器からの信号に基づいて前記主蒸気隔離弁の２次側圧力の変化率が所定値より大であるか否かを判定する２次側圧力変化率判定手段と、前記２次側圧力変化率判定手段により前記主蒸気隔離弁の２次側圧力変化率が所定値より大であると判定されたときはタービンバイパス弁の全閉操作を行うと共にタービントリップ操作を行う制御手段とを備えたことを特徴とする原子力発電所の湿分分離加熱器保護装置。 Moisture separation in nuclear power plants to protect moisture separator heaters that supply main steam from the reactor to remove moisture contained in steam that has finished work at the main turbine of the nuclear power plant In the heater protection device, a secondary pressure detector for detecting a secondary pressure of a main steam isolation valve provided at the reactor outlet, and the main steam based on a signal from the secondary pressure detector The secondary side pressure change rate determining means for determining whether or not the change rate of the secondary side pressure of the isolation valve is larger than a predetermined value, and 2 of the main steam isolation valve by the secondary side pressure change rate determining means. And a control means for performing a turbine trip operation while fully closing the turbine bypass valve when it is determined that the secondary pressure change rate is greater than a predetermined value. Separation heater protection device.

原子力発電所の主タービンで仕事を終えた蒸気に含まれる湿分を原子炉からの主蒸気を供給して除去するようにした湿分分離加熱器を保護するための原子力発電所の湿分分離加熱器保護装置において、前記原子炉出口に設けられた主蒸気隔離弁の１次側圧力を検出する１次側圧力検出器と、前記主蒸気隔離弁の２次側圧力を検出する２次側圧力検出器と、前記１次側圧力検出器及び前記２次側圧力検出器からの信号に基づいて前記主蒸気隔離弁の１次側圧力と２次側圧力との圧力偏差が所定値より大であるか否かを判定する圧力偏差判定手段と、前記圧力偏差判定手段により前記主蒸気隔離弁の１次側圧力と２次側圧力との圧力偏差が所定値より大であると判定されたときはタービンバイパス弁の全閉操作を行うと共にタービントリップ操作を行う制御手段とを備えたことを特徴とする原子力発電所の湿分分離加熱器保護装置。 Moisture separation in nuclear power plants to protect moisture separator heaters that supply main steam from the reactor to remove moisture contained in steam that has finished work at the main turbine of the nuclear power plant In the heater protection device, a primary pressure detector for detecting a primary side pressure of a main steam isolation valve provided at the reactor outlet, and a secondary side for detecting a secondary side pressure of the main steam isolation valve Based on the pressure detector and signals from the primary pressure detector and the secondary pressure detector, the pressure deviation between the primary side pressure and the secondary side pressure of the main steam isolation valve is larger than a predetermined value. It is determined that the pressure deviation between the primary side pressure and the secondary side pressure of the main steam isolation valve is larger than a predetermined value by the pressure deviation judging means for judging whether or not When the turbine bypass valve is fully closed, the turbine trip operation Moisture separator heater protection device of a nuclear power plant, characterized in that a control means for performing.

原子炉からの主蒸気を加熱蒸気元弁及び加熱蒸気圧力調整弁を介して湿分分離加熱器に導き、主タービンで仕事を終えた蒸気に含まれる湿分を前記湿分分離加熱器で除去するようにした原子力発電所の湿分分離加熱器保護装置において、前記原子炉出口に設けられた主蒸気隔離弁の弁状態を検出する弁状態検出装置と、前記弁状態検出装置からの信号に基づいて前記主蒸気隔離弁の弁状態を判定する弁状態判定手段と、前記弁状態判定手段により前記主蒸気隔離弁が全開以外の弁状態であると判定されたときは前記加熱蒸気元弁又は前記加熱蒸気圧力調整弁の全閉操作を行う制御手段とを備えたことを特徴とする原子力発電所の湿分分離加熱器保護装置。 The main steam from the reactor is guided to the moisture separator / heater via the heating steam main valve and the heating steam pressure regulating valve, and the moisture contained in the steam that has finished work in the main turbine is removed by the moisture separator / heater. In the moisture separator heater protection device for a nuclear power plant, a valve state detection device for detecting a valve state of a main steam isolation valve provided at the reactor outlet, and a signal from the valve state detection device A valve state determination means for determining a valve state of the main steam isolation valve based on the heating steam source valve or the valve state determination means when the valve state determination means determines that the main steam isolation valve is in a valve state other than full open A moisture separator heater protection device for a nuclear power plant, comprising control means for performing a fully closing operation of the heating steam pressure regulating valve.

原子炉からの主蒸気を加熱蒸気元弁及び加熱蒸気圧力調整弁を介して湿分分離加熱器に導き、主タービンで仕事を終えた蒸気に含まれる湿分を前記湿分分離加熱器で除去するようにした原子力発電所の湿分分離加熱器保護装置において、前記原子炉出口に設けられた主蒸気隔離弁の２次側圧力を検出する２次側圧力検出器と、前記２次側圧力検出器からの信号に基づいて前記主蒸気隔離弁の２次側圧力が所定値以下であるか否かを判定する２次側圧力判定手段と、前記２次側圧力判定手段により前記主蒸気隔離弁の２次側圧力が所定値以下であると判定されたときは前記加熱蒸気元弁又は前記加熱蒸気調節弁の全閉操作を行う制御手段とを備えたことを特徴とする原子力発電所の湿分分離加熱器保護装置。 The main steam from the reactor is guided to the moisture separator / heater via the heating steam main valve and the heating steam pressure regulating valve, and the moisture contained in the steam that has finished work in the main turbine is removed by the moisture separator / heater. In the moisture separator / heater protection apparatus for a nuclear power plant, a secondary pressure detector for detecting a secondary pressure of a main steam isolation valve provided at the reactor outlet, and the secondary pressure Based on the signal from the detector, secondary pressure determining means for determining whether or not the secondary pressure of the main steam isolation valve is equal to or lower than a predetermined value, and the main steam isolation by the secondary pressure determining means A control means for performing a fully closing operation of the heating steam source valve or the heating steam control valve when it is determined that the secondary pressure of the valve is equal to or less than a predetermined value. Moisture separator heater protection device.

原子炉からの主蒸気を加熱蒸気元弁及び加熱蒸気圧力調整弁を介して湿分分離加熱器に導き、主タービンで仕事を終えた蒸気に含まれる湿分を前記湿分分離加熱器で除去するようにした原子力発電所の湿分分離加熱器保護装置において、前記原子炉出口に設けられた主蒸気隔離弁の２次側圧力を検出する２次側圧力検出器と、前記２次側圧力検出器からの信号に基づいて前記主蒸気隔離弁の２次側圧力の変化率が所定値より大であるか否かを判定する２次側圧力変化率判定手段と、前記２次側圧力変化率判定手段により前記主蒸気隔離弁の２次側圧力変化率が所定値より大であると判定されたときは前記加熱蒸気元弁又は前記加熱蒸気調節弁の全閉操作を行う制御手段とを備えたことを特徴とする原子力発電所の湿分分離加熱器保護装置。 The main steam from the reactor is guided to the moisture separator / heater via the heating steam main valve and the heating steam pressure regulating valve, and the moisture contained in the steam that has finished work in the main turbine is removed by the moisture separator / heater. In the moisture separator / heater protection apparatus for a nuclear power plant, a secondary pressure detector for detecting a secondary pressure of a main steam isolation valve provided at the reactor outlet, and the secondary pressure Secondary pressure change rate determining means for determining whether the change rate of the secondary pressure of the main steam isolation valve is larger than a predetermined value based on a signal from the detector; and the secondary pressure change Control means for fully closing the heating steam source valve or the heating steam control valve when the rate determining means determines that the secondary pressure change rate of the main steam isolation valve is greater than a predetermined value; A moisture separator heater protection device for a nuclear power plant, comprising:

原子炉からの主蒸気を加熱蒸気元弁及び加熱蒸気圧力調整弁を介して湿分分離加熱器に導き、主タービンで仕事を終えた蒸気に含まれる湿分を前記湿分分離加熱器で除去するようにした原子力発電所の湿分分離加熱器保護装置において、前記原子炉出口に設けられた主蒸気隔離弁の１次側圧力を検出する１次側圧力検出器と、前記主蒸気隔離弁の２次側圧力を検出する２次側圧力検出器と、前記１次側圧力検出器及び前記２次側圧力検出器からの信号に基づいて前記主蒸気隔離弁の１次側圧力と２次側圧力との圧力偏差が所定値より大であるか否かを判定する圧力偏差判定手段と、前記圧力偏差判定手段により前記主蒸気隔離弁の１次側圧力と２次側圧力との圧力偏差が所定値より大であると判定されたときは前記加熱蒸気元弁又は前記加熱蒸気調節弁の全閉操作を行う制御手段とを備えたことを特徴とする原子力発電所の湿分分離加熱器保護装置。 The main steam from the reactor is guided to the moisture separator / heater via the heating steam main valve and the heating steam pressure regulating valve, and the moisture contained in the steam that has finished work in the main turbine is removed by the moisture separator / heater. In the moisture separator / heater protection device for a nuclear power plant, a primary pressure detector for detecting a primary pressure of a main steam isolation valve provided at the reactor outlet, and the main steam isolation valve A secondary side pressure detector for detecting the secondary side pressure of the main steam isolation valve based on signals from the primary side pressure detector and the secondary side pressure detector. Pressure deviation determining means for determining whether or not the pressure deviation from the side pressure is greater than a predetermined value, and the pressure deviation between the primary side pressure and the secondary side pressure of the main steam isolation valve by the pressure deviation determining means. Is determined to be greater than a predetermined value, the heating steam source valve or the heating Moisture separator heater protection device of a nuclear power plant, characterized in that a control means for performing all the closing operation of the gas regulating valve.

前記湿分分離加熱器に供給する主蒸気を遮断するための遮断弁を前記加熱蒸気元弁の上流側に設け、前記制御手段は前記加熱蒸気元弁又は前記加熱蒸気調節弁に代えて前記遮断弁の全閉操作を行うようにしたことを特徴とする請求項５乃至請求項８に記載の原子力発電所の湿分分離加熱器保護装置。 A shut-off valve for shutting off the main steam supplied to the moisture separation heater is provided upstream of the heating steam source valve, and the control means replaces the heating steam source valve or the heating steam control valve with the shut-off valve. The apparatus for protecting a moisture separator and heater of a nuclear power plant according to any one of claims 5 to 8, wherein the valve is fully closed .