JP3585975B2 - Isolation and restart systems for moisture separation heater devices and methods thereof - Google Patents

Description

また、弁の開口面積と弁開度の関係は弁の型式により異なるが、弁開度，弁差圧と弁容量係数：Ｃｇ値との関係を示す代表例のグラフを図３に示す。そこで、流量一定制御を行なう加熱蒸気弁２０のグラフを予め求め、第１加熱蒸気定流量制御器３５ａに関数として入力し、Ｃｇ値を制御定数とすることで、Ｃｇ値一定制御、つまり第１加熱器７へ供給する加熱蒸気の流量一定制御を行なうことができる。
【００３７】
すなわち、第１ドレンタンク１０が空になり、水位低々信号Ｓ４が出力され、さらに、第１加熱器７の器内圧力の低下信号により、第１加熱蒸気定流量制御器３５ａからの加熱蒸気定流量制御信号Ｓ５が第１加熱蒸気弁２０に与えられ、加熱蒸気流量を一定に制御する。
【００３８】
ｃ．湿分分離加熱器出口蒸気温度自動制御部
湿分分離加熱器出口蒸気温度自動制御部は、第１加熱器７の器内圧力が一定または、ある変化率以下の条件が成立すると、湿分分離加熱器５の出口蒸気温度の変化率を監視し、蒸気温度低下率が規定値以内になるよう第１加熱蒸気弁２０に対して閉信号を印加し、この第１加熱蒸気弁２０を信号に従って徐々に閉じて全閉させる制御を行う湿分分離加熱器出口蒸気温度制御器３６を有する。
【００３９】
つまり、第１加熱器７の器内圧力が０Ｋｐａ 以下、圧力変化率が１０Ｋｐａ／ｍｉｎ 以下になると、湿分分離加熱器出口蒸気温度制御器３６からの蒸気温度定率低下制御信号Ｓ６の信号により加熱蒸気弁２０が閉動作される。第１加熱蒸気弁２０は全閉信号Ｓ７で第１加熱器７の隔離が完了し、その完了信号Ｓ８が出力される。
【００４０】
（３）第２加熱器隔離制御部
第２加熱器隔離制御部は、上記第１加熱器隔離制御部と同様、ドレン自動排出制御部，加熱蒸気量一定制御部，湿分分離加熱器出口蒸気温度自動制御部から成り、第２加熱器８のドレンタンク１１，第２常用ドレンタンク水位調節弁１４，第２非常用ドレン水位調節弁１９，第２加熱蒸気弁２１を対象に第１加熱器隔離制御部と同じ制御を行なう。
【００４１】
つまり、第１加熱器隔離完了信号Ｓ８により第２加熱器８の隔離が開始されるが、この第２加熱器８の隔離動作は、第１加熱器７の隔離とほぼ同様であり、第２加熱器ドレンタンクドレン排出制御器３４ｂ，第２加熱蒸気定流量制御器３５ｂを有する。
【００４２】
次に本実施例の作用を説明する。
【００４３】
通常運転の状態では、湿分分離加熱器５の加熱蒸気弁２０，２１は全開であり、第１，第２加熱器７，８で発生するドレンは第１，第２ドレンタンク１０，１１へ導かれ、常用ドレンタンク水位調節弁１３，１４を介して給水加熱器１５へ排出されている。ドレン水位が一定水位以上に上昇すると、非常用のドレン水位調節弁１８，１９が開き、ドレンは復水器１６へ排出される。
【００４４】
ここで、湿分分離加熱器５の隔離信号を動作させると、第１加熱器７の第１非常用ドレンタンク水位調節弁１８に対し一定割合開制御信号を与え、この第１非常用ドレン水位調節弁１８を徐々に開く。
【００４５】
この第１非常用ドレンタンク水位調節弁１８の開に伴い、第１ドレンタンク１０の水位が低下すると、第１常用ドレンタンク水位調節弁１３が第１ドレンタンク１０の水位を一定に保つべく閉動作を繰り返し、やがて全閉し、全閉信号が出力される。
【００４６】
この第１常用ドレン水位調節弁１３の全閉信号により第１非常用ドレン水位調節弁１８には第１ドレンタンク１０のドレン水位が予め決められた所定の低下率で低下せしめる水位一定割合低下制御信号が印加され、第１ドレンタンク１０の水位は低下を続ける。
【００４７】
第１ドレンタンク１０の水位が第１非常用ドレンタンク水位調節弁１８の制御範囲を逸脱する値まで低下すると、制御範囲の逸脱直前の信号が第１非常用ドレンタンク水位調節弁１８に印加され続ける。
【００４８】
第１ドレンタンク１０の水位がさらに低下し、空になると、これまでドレンにより圧力的に分離されていた第１加熱器７と復水器１６間の圧力分離が壊れ、第１加熱器７の器内圧力が低下を始める。
【００４９】
第１加熱器７の器内圧力の低下に伴って、第１加熱蒸気弁２０の弁差圧が増え、弁容量係数Ｃｇ値も増大すると、第１加熱蒸気弁２０を通過する蒸気量が増加する。この加熱蒸気量の増加を加熱蒸気定流量制御器３５ａが検出し、第１加熱蒸気弁２０に閉信号を印加し、加熱蒸気流量を一定に保つ制御を行なう。この加熱蒸気流量が一定に保たれることで、湿分分離加熱器５の出口の蒸気温度の変化が規制される。
【００５０】
そして、復水器１６と均圧され第１加熱器７の器内圧力の低下が止まり、また、予め決められた所定の圧力低下率以下になった状態で、第１加熱蒸気弁２０は加熱蒸気流量一定制御による制御を終了する。
【００５１】
この後、湿分分離加熱器５の出口の蒸気温度制御に移行する。この制御は、湿分分離加熱器５の出口の蒸気温度を、予め決められた所定の温度降下率以内で下げるものであり、湿分分離加熱器出口蒸気温度変化率の信号で第１加熱蒸気弁２０を徐々に閉める動作を行なう。第１加熱蒸気弁２０は信号に従って徐々に閉まり、やがて全閉する。第１加熱蒸気弁２０の全閉で第１加熱器７の隔離が完了する。
【００５２】
この第１加熱器７の隔離完了後、第２加熱器８の隔離操作に入る。第２加熱器８の隔離は第１加熱器７の停止と同様な制御であるが、第１加熱器７が隔離完了していることを条件に隔離制御が可能となり、第２非常用ドレンタンク水位調節弁１９および第２加熱蒸気弁２１が制御される弁となる。
【００５３】
したがって、本実施例によれば、湿分分離加熱器５の隔離を手動操作を全く必要としない完全自動操作により安全かつ迅速に行なうことができ、運転員の負担を軽減することができる。また、ドレンタンク１０，１１内のドレンを排出してから、加熱蒸気弁２０，２１を閉じるので、ドレンフラッシュに起因する、サージング現象による機器の損傷を防止することができ、隔離操作の安全性を向上させることができる。
【００５４】
さらにまた、各ドレンタンク１０，１１に滞留するドレンの排出を非常用ドレン水位調節弁１８，１９を、一定割合開制御とドレン水位定割合低下制御により開度制御することにより水位制御の外乱を抑制すると共に、ドレンタンク水位調節の制御範囲を逸脱する空の状態まで、確実にドレンを排出できる。
【００５５】
さらに、このドレン排出後の第１，第２加熱器７，８の器内圧力低下に伴う、加熱蒸気量の増加事象に対し、加熱蒸気弁２０，２１の弁容量係数Ｃｇ値を一定に保つことで、加熱蒸気量を一定に制御する方法を採用したので、加熱蒸気流量をオリフィスまたはフローノズル等で流量を直接計測し、流量信号をもって制御する一般的方法に比して流量計測設備無しに流量一定制御が可能である。
【００５６】
さらにまた、加熱蒸気弁２０，２１の上流の蒸気条件が一定であることから、これら加熱蒸気弁２０，２１の下流に位置する第１，第２加熱器７，８の器内圧力を検出し、加熱蒸気量一定制御の信号とすることができる。
【００５７】
また、ドレンタンク１０，１１の滞留ドレンを排出した後、第１，第２加熱器７，８への加熱蒸気の供給を停止するので、ドレンフラッシュの虞無しに加熱蒸気弁２０，２１を湿分分離加熱器５の出口の蒸気温度降下率に従って閉じる制御が可能となる。
【００５８】
次に、上記隔離システム３１または他の隔離方法により湿分分離加熱器５を一旦隔離した後、この湿分分離加熱器５を再起動する場合の再起動システムおよびその方法の各実施例について説明する。
【００５９】
まず、その第１実施例は、図４に示すように第１，第２加熱蒸気弁２０，２１（２１ａ，２１ｂ，２１ｃ）を開弁して湿分分離加熱器５の再起動する前に、常用ドレンタンク水位調節弁１３，１４を強制的に所定時間全開せしめる制御装置４１を有する。なお、図４および図７，図８は第２加熱器８の再起動のみを図示しているが、第１加熱器７の再起動についても同様とする。
【００６０】
つまり、この制御装置４１は湿分分離加熱器５の隔離により第２加熱蒸気弁２１の元弁２１ａおよびその調節弁２１ｂ，２１ｃが全閉している場合に、再起動信号が入力されたときに、これら加熱蒸気弁２１ａ〜２１ｃを開く前に、常用ドレンタンク水位調節弁１４を所定時間強制的に全開させるものである。
【００６１】
したがって、再起動の際には、常用ドレンタンク水位調節弁１３，１４の強制全開により、加熱器７，８とドレンタンク１０，１１は既に開弁している非常用ドレンタンク水位調節弁１８，１９を通して復水器１６の内圧と等しいため、圧力的にはドレンタンク出口逆止弁２５，２６の前後で圧力が区切れ、ドレンタンク出口逆止弁２５，２６の下流側圧力Ｐａの方が上流側の圧力Ｐｂよりも高いためドレンタンク出口逆止弁２５，２６は閉弁状態である。
【００６２】
しかし、ドレンタンク出口逆止弁２５，２６と常用ドレンタンク水位調節弁１３，１４との間の中間ドレン配管２７，２８内に滞留している凝縮ドレンは給水加熱器１５と均圧しているので、この凝縮ドレンは、高圧の飽和ドレン状態から給水加熱器１５の内圧と同一の圧力の飽和ドレンまでに圧力が下がり、温度，圧力共に給水加熱器１５の器内状態と等しくなる。
【００６３】
このために、再起動時、加熱蒸気弁２１（２１ａ，２１ｂ，２１ｃ）が開弁して、ドレンタンク１０，１１の器内圧が上昇し、その前後の圧力がＰｂ＞Ｐａとなってドレンタンク出口逆止弁２５，２６が開となったとき、ドレンタンク出口逆止弁２５，２６の入口前は飽和ドレンであり、圧力的にも逆止弁２５，２６前後でドレンの状態が等しいためウォータハンマーの発生を有効に防止することができる。
【００６４】
図５はこのような本実施例による弁操作のタイミングチャートであり、これは図６の従来の弁操作タイミングチャートに示すように、従来は、常用ドレンタンク水位調節弁１３，１４を再起動前に全閉せしめるのに対し、全開させている点を示している。
【００６５】
図７は本発明の第２実施例の再起動システムを示しており、これはドレンタンク出口逆止弁２５，２６と常用ドレンタンク水位調節弁１３，１４との間の各中間ドレン配管２７，２８の途中に、復水器１６に接続されたバイパスライン５１を接続し、これらバイパスライン５１にドレン弁５２を介装すると共に、このドレン弁５２を、再起動のために加熱蒸気弁２０，２１を開弁する前に所定時間強制的に開弁する制御装置５３を設けた点に特徴がある。
【００６６】
したがって、再起動の際には制御装置５３により、まずドレン弁５２が開弁されるので、ドレンタンク出口逆止弁２５，２６と常用ドレンタンク水位調節弁１３，１４間の中間ドレン配管２７，２８内に滞留する凝縮ドレンは復水器１６へ排出される。このドレンの圧力は高い状態の飽和ドレン状態から復水器１６の内圧までが低下するので、圧力と温度と共に低下する。
【００６７】
そして、その状態で加熱蒸気弁２０，２１を開弁して湿分分離加熱器５を起動した場合、ドレンタンク出口逆止弁２５，２６と常用ドレンタンク水位調節弁１３，１４との間の中間ドレン配管２７，２８に流入する凝縮ドレンの方が常に温度的に高いので、ウォータハンマーの発生を有効に防止することができる。
【００６８】
図８は本発明の第３実施例の再起動システムを示しており、これは再起動のために加熱蒸気弁２０，２１を開弁する前に、ドレンタンク出口逆止弁２５，２６と常用ドレンタンク水位調節弁１３，１４間の中間ドレン配管２７，２８内に滞留する凝縮ドレンの温度がその前後の配管内の流体温度よりも低下するまで常用ドレンタンク水位調節弁１３，１４を所定時間強制的に閉じる制御装置６１を設けた点に特徴がある。
【００６９】
したがって、制御装置６１は常用ドレンタンク水位調節弁１３，１４を所定時間強制的に閉じた後、加熱蒸気弁２０，２１を開弁して湿分分離加熱器５を起動するので、ドレンタンク出口逆止弁２５，２６と常用ドレンタンク水位調節弁１３，１４との間の中間ドレン配管２７，２８に流入する駆動ドレンの方が温度的に高くなるためウォータハンマーの発生を有効に防止することができる。
【００７０】
つまり、従来の起動方法では図９に示すように、ドレンタンク１０，１１の温度Ｔ１ よりも中間ドレン配管２７，２８の温度Ｔ２ の方が高いためウォータハンマーが発生しているが、本実施例では図１０に示すように、、再起動前にドレンタンク１０，１１の温度Ｔ１ａが中間ドレン配管２７，２８の温度Ｔ２ａとほぼ等しくなるので、ウォータハンマを防止することができる。
【００７１】
なお、図９，１０中、Ｔ３ とＴ３ａは従来例と本実施例とにおける給水加熱器１５の温度、Ｔ４ とＴ４ａは同、非常用ドレンタンク水位弁１８，１９の上流側の配管温度をそれぞれ示す。また、図４，７，８では第２の加熱器ラインのみを示し、第１加熱器ラインを図示省略している。
【００７２】
【発明の効果】
以上説明したように本願第１，第２の発明は、湿分分離加熱器装置から湿分分離加熱器を隔離するときに、その加熱器への加熱蒸気の供給を停止する前に、まずドレンタンク内のドレンを復水器へ排出する。したがって、このドレン排出時にはまだ加熱蒸気が加熱器へ供給されているので、この加熱器内圧力が高いためにドレンフラッシュを未然にかつ有効に防止することができる。
【００７３】
しかし、このドレン排水によりドレンタンクが空になると、ドレンにより圧力分離されていた加熱器と復水器とがドレン管を介して均圧されるので、加熱器器内圧が急激に低下する。
【００７４】
このために、加熱器へ流入する加熱蒸気量の増加をもたらし、配管や加熱器器内の蒸気流速を増大させ、これら機器等を振動させ、機器を損傷させる虞が発生するが、加熱蒸気弁の加熱器へ流入する加熱蒸気流量を所定値以下に制御するので、これらの虞を未然にかつ有効に防止することができる。
【００７５】
また、加熱器の出口側の蒸気温度の低下を、低圧タービンの損傷を発生させない変化率に制御することができるので、低圧タービンの損傷を未然かつ有効に防止することができる。つまり、運転中の湿分分離加熱器を安全かつ可及的速かに自動的に隔離することができる。
【００７６】
また、本願の第３〜第６の発明は、上記隔離方法または他の方法等により、一旦、隔離された湿分分離加熱器を再起動する場合は、その隔離後、ドレンタンクから給水加熱器までの間のドレン流路に滞留しているドレンを、給水加熱器または復水器の器内圧力に均圧させ、あるいはこのドレン流路内に所定時間閉じ込めて放熱させることによりドレン温度を低下させるので、再起動時のウォータハンマーを未然かつ有効に防止することができる。したがって、隔離後の湿分分離加熱器を安全かつ可及的速かに自動的に再起動することができる。
【００７７】
さらに、本願第７の発明は、上記第１の発明に係る隔離システムと、上記第３〜第６のいずれかに係る再起動システムとを有するので、湿分分離加熱器の隔離と再起動とを安全かつ迅速に自動的に行なうことができる。
【図面の簡単な説明】
【図１】本発明に係る湿分分離加熱器装置の隔離システムおよびその方法の一実施例の制御を示すブロック図。
【図２】図３で示す加熱蒸気弁の弁容量係数を示すグラフ。
【図３】本発明が適用される湿分分離加熱器装置の一例の系統構成図。
【図４】本発明に係る湿分分離加熱器装置の再起動システムおよびその方法の一実施例の構成と作用を示す要部拡大図。
【図５】図４で示す本発明の一実施例に係る再起動システムの弁操作タイミングチャート。
【図６】従来の再起動方法の弁操作タイミングチャート。
【図７】本発明に係る再起動システムの他の実施例の構成等を示す要部拡大図。
【図８】本発明に係る再起動システムのさらに他の実施例の構成等を示す要部拡大図。
【図９】従来の再起動方法により再起動されたときの各所の温度分布を示す図。
【図１０】図８で示す再起動システムにより再起動されたときの各所の温度分布を示す図。
【符号の説明】
１ 湿分分離加熱器装置
３ 蒸気タービンの高圧タービン
４ 低圧タービン
５ 湿分分離加熱器
６ 湿分加熱器
７ 第１加熱器
８ 第２加熱器
９，１０，１１ ドレンタンク
１２，１３，１４ 常用ドレンタンク水位調節弁
１５ 給水加熱器
１６ 復水器
１７，１８，１９ 非常用ドレンタンク水位調節弁
２０，２１ 加熱蒸気弁
２２，２３ ドレン配管
２４，２５，２６ ドレンタンク出口逆止弁
２７，２８ 中間ドレン配管
３４ａ，３４ｂ 第１，第２加熱器ドレンタンクドレン排出制御器
３５ａ，３５ｂ 第１，第２加熱蒸気定流量制御器
３６ 湿分分離加熱器出口蒸気温度制御器[0001]
[Industrial applications]
The present invention relates to an isolation system and a restart system for a moisture separation heater device in a steam turbine plant, and a method thereof, and more particularly to prevention of drain flash at the time of isolation for stopping operation of the moisture separation heater and the like. The present invention relates to an isolation system and a restart system of a moisture separation heater device for preventing a water hammer at the time of startup, and a method thereof.
[0002]
[Prior art]
Generally, a steam turbine plant such as a thermal power plant or a nuclear power plant includes, for example, a moisture separation heater device 1 shown in FIG. This apparatus 1 is provided with a moisture separation heater 5 between a high-pressure turbine 3 and a low-pressure turbine 4 of a steam turbine for driving a generator 2 and the like.
[0003]
This moisture separation heater 5 is a moisture separator 6 for separating the moisture of the steam from the high-pressure turbine 3, and first and second heaters for heating the steam with the heating steam and supplying the steam to the low-pressure turbine 4. 7 and 8. Drains generated by the moisture separator 6 and the first and second heaters 7 and 8 are respectively transferred to drain tanks 9, 10 and 11 for separate moisture separators and first and second heaters. The water is drained to the feed water heater 15 through the common drain tank water level control valves 12, 13, and 14 while storing a large amount of water. In addition, emergency drain tank water level control valves 17, 18, 19 for draining these drains to the condenser 16 when the drain water levels in the drain tanks 9, 10, 11 are abnormally high are provided.
[0004]
Then, during the operation of the plant, when the operation of the used moisture separator / heater 5 is stopped to be isolated, first, the heated steam valves 20 and 21 of the first and second heaters 7 and 8 are connected to the low-pressure turbine 4. The steam is gradually closed manually so that the rate of decrease in the temperature of the inflowing steam becomes equal to or less than a specified value. After that, the drains in the drain tanks 10 and 11 for the first and second heaters are drained to the condenser 16 via the emergency drain tank water level control valves 18 and 19.
[0005]
On the other hand, when the moisture separation heater 5 thus isolated from the apparatus 1 is restarted, the load on the plant is reduced to, for example, about 10% in order to avoid a rapid temperature change of the equipment, and then the first and the second are started. (2) The ordinary drain tank water level control valves 13 and 14 are gradually opened. However, while the isolation operation is generally performed at a load close to 100%, when the plant load is reduced to about 10% load, the internal pressure of the feed water heater 15, the turbine extraction pressure, etc., greatly decrease. When restarting from the start of the isolation operation, the first and second heaters 7 and 8 and the first and second heaters 7 and 8 are opened by opening the first and second emergency drain tank water level control valves 18 and 19. The condensed drain in the drain tanks 10 and 11 is discharged to the condenser 16.
[0006]
In this case, the first and second emergency drain tank water level control valves 18 and 19 are fully closed when the condensed drain in each of the drain tanks 7 and 8 is drained to the condenser 16. (2) The pressure difference is reversed between before and after the drain tank outlet check valves 25 and 26, and the drain tank outlet check valves 25 and 26 are fully closed, so that the condensed drain is discharged from the drain tank outlet check valves 25 and 26 and the normal drain. In the drain pipe between the tank water level control valves 18 and 19, the water is sealed and retained in a high temperature and high pressure state.
[0007]
[Problems to be solved by the invention]
However, in such a conventional method for separating the moisture separating heater 5, the internal pressure of each of the heaters 7 and 8 starts to decrease rapidly due to a decrease in the amount of the heating steam accompanying the operation of stopping the heating steam. The saturated drain retained in the drain tanks 10 and 11 retains the amount of heat before the isolation operation, and the retained drain begins to flush as the pressure in the heaters 7 and 8 decreases.
[0008]
The flash steam flows back toward the heaters 7 and 8, causing a water hammer phenomenon in the drain pipes 22 and 23 and the heaters 7 and 8, which may damage equipment. For this reason, conventionally, the heating steam has been manually stopped gradually, for example, for 3 to 4 hours so that the drain does not suddenly flash. Originally, the time required for keeping the rate of decrease in the temperature of the steam flowing into the low-pressure turbine 4 below a specified value and isolating the moisture separation heater 5 is, for example, about 30 minutes. The manual isolation operation was not only a heavy burden on the operators, but also a risk of equipment damage due to operation errors.
[0009]
In the conventional restart method, when the first and second heating steam valves 20 and 21 are opened, the heating steam flows into the first and second heaters 7 and 8 and water surfaces are formed in the drain tanks 10 and 11. When the service drain tank water level control valves 13 and 14 are opened, the temperature of the fluid in the drain tanks 10 and 11 changes from the drain tank outlet check valves 25 and 26 to the service drain tank water level control valves 13 and 14. Is lower than the temperature of the fluid staying in the intermediate drain pipes 27 and 28 between them, a water hammer is generated in the vicinity of the drain tank outlet check valves 25 and 26, and an excessive load is applied to equipment such as the piping system. Is done.
[0010]
Further, the internal pressure of the feed water heater 15 is lower than the temperature of the fluid retained in the intermediate drain pipes 27 and 28 from the drain tank outlet check valves 25 and 26 to the normal drain tank water level control valves 13 and 14. When the service drain tank water level control valves 13 and 14 are opened, there is a problem that a water hammer is also generated in the vicinity of the valves 13 and 14 and an excessive load is applied to the piping system.
[0011]
Therefore, the present invention has been made in view of these circumstances, and an object of the present invention is to prevent the occurrence of a saturated drain flush in a drain tank and to operate a moisture separation heater safely and quickly while operating. And a method of controlling the decrease in the temperature of steam flowing into the low-pressure turbine at a rate that does not cause damage to the turbine. is there.
[0012]
Another object of the present invention is to provide a moisture separation heater that can be safely and quickly automatically restarted after isolation of a moisture separation heater by effectively preventing a drain water hammer from being generated in a piping system or the like. It is an object of the present invention to provide a restart system for a separation heater device and a method thereof.
[0013]
[Means for Solving the Problems]
The present invention is configured as follows in order to solve the above problems.
[0014]
The invention described in claim 1 of the present application (hereinafter, referred to as a first invention) removes moisture from a high-pressure turbine by a moisture separator and heats the exhaust steam by a heater that passes heated steam. And a heater for controlling the inflow of the heating steam supplied to the heater, and a drain from the heater and the moisture separator, respectively. On the other hand, a drain tank that selectively drains water to a feed water heater or a condenser, respectively, in a moisture separation heater device having a drain drain unit that drains the drain in the drain tank for the heater to the condenser. After the drainage, the heating steam inflow into the heater is controlled to a constant value by controlling the opening of the heating steam valve to reduce the internal pressure of the heater to a predetermined value or less. Constant control means, and control means for gradually closing and fully closing the heating steam valve so that the steam temperature decrease rate at the outlet of the moisture separation heater becomes within a predetermined value after the heating steam inflow amount constant control. , Is characterized by having.
[0015]
Further, the invention described in claim 2 of the present application (hereinafter, referred to as a second invention) removes the moisture from the high-pressure turbine by a moisture separator and removes the moisture from the high-pressure turbine by a heater that passes heated steam. A moisture separation heater for heating and supplying to the low pressure turbine, a heating steam valve for controlling an inflow amount of the heating steam supplied to the heater, and a drain from the heater and the moisture separator, respectively. A drain tank that selectively stores and drains water to a feed water heater or a condenser, respectively, in a moisture separation heater device, the drain in the heater drain tank is drained to the condenser, After drain drainage, the heating steam inflow into the heater is controlled to be constant by controlling the opening degree of the heating steam valve to reduce the pressure inside the heater to a predetermined value or less. control And isolating the moisture separation heater by gradually closing and fully closing the heating steam valve so that the steam temperature reduction rate at the outlet of the moisture separation heater is within a predetermined value. .
[0016]
Further, in the invention described in claim 3 of the present application (hereinafter referred to as a third invention), the steam discharged from the high-pressure turbine is removed by a moisture separator, and the steam discharged from the high-pressure turbine is heated by a heater passing the heated steam. A moisture separation heater for heating and supplying to the low pressure turbine, a heating steam valve for controlling an inflow amount of the heating steam supplied to the heater, and a drain from the heater and the moisture separator, respectively. A drain tank that selectively stores and drains water to a feed water heater or a condenser, respectively, wherein the water supply from the heater drain tank is performed after the moisture separation heater is isolated. There is provided a means for operating the moisture separation heater after equalizing the pressure of the drain staying in the drain flow path to the heater with the internal pressure of the feed water heater.
[0017]
Still further, the invention according to claim 4 of the present application (hereinafter referred to as a fourth invention) is a heater that removes moisture from steam discharged from a high-pressure turbine by a moisture separator and passes heated steam. A heater for heating and supplying to the low-pressure turbine, a heating steam valve for controlling an inflow amount of the heating steam supplied to the heater, and a drain from the heater and the moisture separator. And a drain tank for selectively draining water to a feed water heater or a condenser, respectively, while storing the feed water heater or the condenser. It is characterized by having a means for operating the moisture separation heater after equalizing the pressure of the drain retained in the drain flow path to the vessel with the internal pressure of the condenser.
[0018]
The invention described in claim 5 of the present application (hereinafter, referred to as a fifth invention) removes the moisture from the high-pressure turbine by a moisture separator and removes the moisture from the high-pressure turbine by a heater that passes the heating steam. A moisture separation heater for heating and supplying to the low pressure turbine, a heating steam valve for controlling an inflow amount of the heating steam supplied to the heater, and a drain from the heater and the moisture separator, respectively. A drain tank that selectively stores and drains water to a feed water heater or a condenser, respectively, wherein the water supply from the heater drain tank is performed after the moisture separation heater is isolated. It is characterized by having a means for confining the drain stagnating in the drain flow path to the heater in the drain flow path for a predetermined time to release heat and then operating the moisture separation heater.
[0019]
Further, in the invention according to claim 6 of the present application (hereinafter referred to as a sixth invention), the steam discharged from the high-pressure turbine is removed by a moisture separator, and the steam discharged by the heater is passed through a heater. A moisture separation heater for heating and supplying to the low pressure turbine, a heating steam valve for controlling an inflow amount of the heating steam supplied to the heater, and a drain from the heater and the moisture separator, respectively. A drain tank that selectively stores and drains water to a feed water heater or a condenser, respectively, wherein the water supply from the heater drain tank is performed after the moisture separation heater is isolated. The method is characterized in that the moisture separation heater is operated after the temperature of the drain staying in the drain passage to the heater is lowered.
[0020]
Furthermore, the invention according to claim 7 of the present application (hereinafter referred to as a seventh invention) includes the isolation system according to claim 1 and the restart system according to any one of claims 2 to 5. It is characterized by having.
[0021]
[Action]
<First and second inventions>
In order to isolate the moisture separation heater from the moisture separation heater device, the present invention first condenses the drain in the drain tank for the heater before stopping the supply of the heating steam to the heater. Drain into container. Therefore, since the heating steam is still supplied to the heater at the time of drain discharge, the drain flush can be prevented beforehand and effectively because the pressure inside the heater is high.
[0022]
However, when the drain tank is emptied by the drain water, the pressure of the heater separated by the drain is equalized through the condenser and the drain pipe, so that the internal pressure of the heater rapidly decreases.
[0023]
This causes an increase in the amount of heated steam flowing into the heater, increases the flow velocity of steam in the piping and the heater, vibrates these devices and the like, and may cause damage to the devices. By controlling the opening degree, the flow rate of the heating steam flowing into the heater is suppressed to a predetermined value or less, so that these fears can be effectively and effectively prevented.
[0024]
In addition, since the decrease in the steam temperature at the outlet side of the heater can be controlled to a change rate that does not cause damage to the low-pressure turbine, damage to the low-pressure turbine can be prevented effectively beforehand. That is, it is possible to automatically and safely isolate the operating moisture separator heater as quickly as possible.
[0025]
<Third to sixth inventions>
According to the present invention, when the isolated moisture separation heater is once restarted by the above isolation method or the like, after the isolation, the moisture stays in the drain flow path from the drain tank for the heater to the feed water heater. Drain temperature is reduced by equalizing the drain that is present with the internal pressure of the feed water heater or condenser, or by confining it in this drain flow path for a predetermined time to release the heat, thus effectively preventing water hammer can do. Therefore, the moisture separation heater after isolation can be automatically restarted safely and as quickly as possible.
[0026]
<Seventh invention>
Since the present invention includes the isolation system according to the first invention and the restart system according to any of the third to sixth aspects, the isolation and restart of the moisture separation heater can be performed safely and promptly. Can be done automatically.
[0027]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 10, the same or corresponding parts are denoted by the same reference numerals.
[0028]
FIG. 1 is a control block diagram of an embodiment of an isolation system for a moisture separation heater device according to the present invention. The automatic isolation system 31 performs the operation of the moisture separation heater device 1 shown in FIG. The separation / separation heater 5 is automatically stopped to perform safe and quick isolation. The separation / separation heater 5 is roughly divided into an isolation signal switch unit, a first heater isolation control unit, and a second heater isolation control unit. Each of these heater isolation control units includes a drain automatic discharge control unit, a heating steam amount constant control unit, and a moisture separation heater outlet steam temperature automatic control unit.
[0029]
(1) Isolation signal switch section
This has three switches of “first heater isolation”, “second heater isolation”, and “first and second heater interlock isolation”, and the switch ON signal of “first heater isolation” , Only the first heater 7 is isolated. Further, with the switch ON signal of “second heater isolation”, the second heater 8 is isolated on condition that the isolation of the first heater 7 is completed. With the “first and second heater interlocking isolation” switch ON signal, the second heater 8 is isolated after the isolation of the first heater 7 is completed.
[0030]
(2) First heater isolation control unit
a. Drain automatic discharge control unit
Generally, as the moisture separation heater device 1, the drain is controlled by appropriately controlling the opening of each of the common drain tank water level control valves 12 to 14 in order to maintain the drain water in each of the drain tanks 9 to 11 at a constant water level. First and second regular drain tank water level regulators 32a and 32b for draining to the feed water heater 15, and emergency drain tank water level control valves 12 to 14 when the drain water level in each of the drain tanks 9 to 11 rises abnormally. The first and second emergency drain tank water level adjusters 32a and 32b for draining the drain to the condenser 16 by appropriately controlling the opening degree of the drain tank are provided.
[0031]
And as a drain automatic discharge control part, it has the 1st heater drain tank drain discharge controller 34a. 34a is an ON signal of an isolation signal switch of "first heater isolation" or "first and second heater interlock isolation", and provides a constant rate opening control signal to the first emergency drain water level control valve 18. While the valve 18 is opened, a signal for controlling the first emergency drain tank water level control valve 18 to open at a constant rate is a signal indicating that the first service drain tank water level control valve 13 is fully closed. The control is switched to a control signal for lowering the fixed rate, and the drain of the first drain tank 10 is automatically discharged to the condenser 16.
[0032]
Therefore, when the isolation signal is issued, the first emergency drain tank water level control valve 18 is opened by the emergency water level control valve fixed rate open signal S1 from the first heater drain tank drain discharge controller 34a, and the first emergency drain tank water level control valve 18 is opened. The drain of the drain tank 10 is discharged to the condenser 16, and the first working drain tank water level control valve 13 is fully closed.
[0033]
The control signal of the first emergency drain tank water level control valve 18 is switched to the constant water level decrease control signal S3 by the fully closed signal S2 of the first service drain tank water level control valve 13, and the drain is continued. Empty the tank 10.
[0034]
b. Heating steam constant control section
The heating steam constant control unit obtains the differential pressure of the heating steam valve 20 for the first heater 7 from the change in the internal pressure of the first heater 7, and calculates the heating steam with the increase in the pressure difference of the heating steam valve 20. Control is performed to correct the increase in the amount and keep the heating steam amount constant.
[0035]
In general, the flow rate of a fluid passing through a valve can be represented as a valve capacity coefficient Cg determined by the opening area of the valve and the valve differential pressure. As shown in the following equation 1, as the value of the valve capacity coefficient Cg increases, the flow rate of the fluid passing through the valve increases, and the value of the valve capacity coefficient Cg remains the same even if the opening area of the valve or the valve differential pressure changes. If so, the flow rate of fluid through the valve is constant.
[0036]
(Equation 1)

The relationship between the opening area of the valve and the valve opening varies depending on the type of the valve. FIG. 3 shows a graph of a representative example showing the relationship between the valve opening, the valve differential pressure, and the valve capacity coefficient: Cg value. Therefore, a graph of the heating steam valve 20 for performing the constant flow rate control is obtained in advance, and is input to the first heating steam constant flow rate controller 35a as a function, and the Cg value is used as a control constant. The constant flow rate control of the heating steam supplied to the heater 7 can be performed.
[0037]
That is, the first drain tank 10 is emptied, the low water level signal S4 is output, and furthermore, the heating steam from the first heating steam constant flow rate controller 35a is output by the signal for decreasing the internal pressure of the first heater 7. A constant flow rate control signal S5 is provided to the first heating steam valve 20, and controls the heating steam flow rate to be constant.
[0038]
c. Automatic control unit for steam temperature at outlet of moisture separator heater
When the internal pressure of the first heater 7 is constant or a condition that is equal to or less than a certain rate of change is satisfied, the moisture-separation heater outlet steam temperature automatic control unit determines the rate of change of the outlet steam temperature of the moisture-separation heater 5. Monitoring is performed, and a closing signal is applied to the first heating steam valve 20 so that the steam temperature reduction rate is within a specified value, and the first heating steam valve 20 is controlled to gradually close and fully close according to the signal. It has a steam heater controller 36 at the outlet of the separation heater.
[0039]
That is, when the internal pressure of the first heater 7 is 0 Kpa or less and the pressure change rate is 10 Kpa / min or less, heating is performed by the signal of the steam temperature constant rate decrease control signal S6 from the moisture separation heater outlet steam temperature controller 36. The steam valve 20 is closed. The first heating steam valve 20 completes the isolation of the first heater 7 by the fully closed signal S7, and outputs the completion signal S8.
[0040]
(3) Second heater isolation control unit
The second heater isolation control section, like the first heater isolation control section, includes a drain automatic discharge control section, a heating steam amount constant control section, a moisture separation heater outlet steam temperature automatic control section, and a second heating section. The same control as the first heater isolation control unit is performed for the drain tank 11, the second service drain tank water level control valve 14, the second emergency drain water level control valve 19, and the second heating steam valve 21 of the heater 8.
[0041]
That is, the isolation of the second heater 8 is started by the first heater isolation completion signal S8. The isolation operation of the second heater 8 is almost the same as the isolation of the first heater 7, and the second heater 8 is isolated. It has a heater drain tank drain discharge controller 34b and a second heating steam constant flow controller 35b.
[0042]
Next, the operation of the present embodiment will be described.
[0043]
In a normal operation state, the heating steam valves 20 and 21 of the moisture separation heater 5 are fully opened, and the drain generated in the first and second heaters 7 and 8 flows to the first and second drain tanks 10 and 11. The water is guided and discharged to the feed water heater 15 through the common drain tank water level control valves 13 and 14. When the drain water level rises above a certain level, the emergency drain water level control valves 18 and 19 are opened, and the drain is discharged to the condenser 16.
[0044]
Here, when the isolation signal of the moisture separation heater 5 is operated, an opening control signal is given to the first emergency drain tank water level control valve 18 of the first heater 7 at a fixed rate, and the first emergency drain water level is controlled. The control valve 18 is gradually opened.
[0045]
When the water level in the first drain tank 10 decreases with the opening of the first emergency drain tank water level control valve 18, the first normal drain tank water level control valve 13 closes to maintain the water level in the first drain tank 10 constant. The operation is repeated, and finally the valve is fully closed, and a fully closed signal is output.
[0046]
The first emergency drain water level control valve 18 controls the first emergency drain water level control valve 18 to decrease the drain water level of the first drain tank 10 at a predetermined reduction rate in response to the fully closed signal of the first service drain water level control valve 13. The signal is applied, and the water level in the first drain tank 10 continues to decrease.
[0047]
When the water level in the first drain tank 10 falls to a value outside the control range of the first emergency drain tank water level control valve 18, a signal immediately before the control range departs is applied to the first emergency drain tank water level control valve 18. to continue.
[0048]
When the water level in the first drain tank 10 further decreases and becomes empty, the pressure separation between the first heater 7 and the condenser 16 which has been separated by pressure by the drain is broken, and the first heater 7 The internal pressure starts to decrease.
[0049]
When the internal pressure of the first heater 7 decreases, the valve differential pressure of the first heating steam valve 20 increases, and when the valve capacity coefficient Cg also increases, the amount of steam passing through the first heating steam valve 20 increases. I do. The heating steam constant flow rate controller 35a detects the increase in the heating steam amount, applies a closing signal to the first heating steam valve 20, and performs control to keep the heating steam flow rate constant. By keeping the heating steam flow rate constant, a change in the steam temperature at the outlet of the moisture separation heater 5 is regulated.
[0050]
Then, the pressure in the condenser 16 is equalized, the pressure in the first heater 7 stops decreasing, and the first heating steam valve 20 is heated in a state in which the pressure decreases below a predetermined pressure reduction rate. The control by the steam flow constant control is ended.
[0051]
Thereafter, the process shifts to control of the steam temperature at the outlet of the moisture separation heater 5. This control lowers the steam temperature at the outlet of the moisture separation heater 5 within a predetermined temperature drop rate, and uses the signal of the steam temperature change rate at the outlet of the moisture separation heater to output the first heating steam. An operation of gradually closing the valve 20 is performed. The first heating steam valve 20 gradually closes according to the signal, and eventually closes completely. When the first heating steam valve 20 is fully closed, the isolation of the first heater 7 is completed.
[0052]
After the isolation of the first heater 7 is completed, the operation of isolating the second heater 8 is started. The isolation of the second heater 8 is the same control as the stop of the first heater 7, but the isolation control becomes possible on condition that the isolation of the first heater 7 is completed, and the second emergency drain tank The water level control valve 19 and the second heated steam valve 21 are controlled valves.
[0053]
Therefore, according to the present embodiment, isolation of the moisture separation heater 5 can be performed safely and promptly by fully automatic operation which does not require any manual operation, and the burden on the operator can be reduced. In addition, since the heating steam valves 20 and 21 are closed after draining the drains in the drain tanks 10 and 11, damage to the equipment due to a surging phenomenon due to drain flushing can be prevented, and the safety of the isolation operation can be improved. Can be improved.
[0054]
Furthermore, the discharge of the drain remaining in each of the drain tanks 10 and 11 is controlled by opening the emergency drain water level control valves 18 and 19 by a constant ratio opening control and a drain water constant constant ratio lowering control, thereby disturbing the disturbance of the water level control. In addition to the suppression, the drain can be reliably discharged to an empty state that deviates from the control range of the drain tank water level adjustment.
[0055]
Furthermore, the valve capacity coefficient Cg of the heating steam valves 20 and 21 is kept constant in response to an event of an increase in the amount of heating steam due to a decrease in the internal pressure of the first and second heaters 7 and 8 after draining. By adopting a method of controlling the amount of heating steam constant, the flow rate of heating steam is directly measured with an orifice or a flow nozzle, etc. Flow constant control is possible.
[0056]
Furthermore, since the steam conditions upstream of the heating steam valves 20 and 21 are constant, the internal pressures of the first and second heaters 7 and 8 located downstream of the heating steam valves 20 and 21 are detected. And a signal for controlling the amount of heating steam constant.
[0057]
In addition, since the supply of the heating steam to the first and second heaters 7 and 8 is stopped after draining the accumulated drain in the drain tanks 10 and 11, the heating steam valves 20 and 21 are wetted without danger of drain flush. The closing control according to the steam temperature drop rate at the outlet of the minute separation heater 5 becomes possible.
[0058]
Next, a description will be given of a restart system and a method for restarting the moisture separation heater 5 after the moisture separation heater 5 is once isolated by the above-described isolation system 31 or another isolation method. I do.
[0059]
First, in the first embodiment, as shown in FIG. 4, before the first and second heating steam valves 20, 21 (21a, 21b, 21c) are opened and the moisture separation heater 5 is restarted. And a control device 41 for forcibly fully opening the service drain tank water level control valves 13 and 14 for a predetermined time. 4, 7 and 8 show only the restart of the second heater 8, but the same applies to the restart of the first heater 7.
[0060]
In other words, when the main valve 21a of the second heating steam valve 21 and its control valves 21b and 21c are fully closed due to the isolation of the moisture separation heater 5, the control device 41 receives a restart signal. Before the heating steam valves 21a to 21c are opened, the normal drain tank water level control valve 14 is forcibly fully opened for a predetermined time.
[0061]
Therefore, at the time of restarting, the heaters 7 and 8 and the drain tanks 10 and 11 are forced to fully open the service drain tank water level control valves 13 and 14 so that the emergency drain tank water level control valves 18 and Since the pressure is equal to the internal pressure of the condenser 16 through 19, the pressure is divided before and after the drain tank outlet check valves 25 and 26, and the downstream pressure Pa of the drain tank outlet check valves 25 and 26 is lower. Since the pressure Pb is higher than the upstream pressure Pb, the drain tank outlet check valves 25 and 26 are closed.
[0062]
However, the condensed drain retained in the intermediate drain pipes 27 and 28 between the drain tank outlet check valves 25 and 26 and the service drain tank water level control valves 13 and 14 is equalized with the feed water heater 15. The pressure of the condensed drain drops from a high-pressure saturated drain state to a saturated drain having the same pressure as the internal pressure of the feed water heater 15, and both the temperature and the pressure become equal to those in the feed water heater 15.
[0063]
For this reason, at the time of restart, the heating steam valve 21 (21a, 21b, 21c) opens, the internal pressure of the drain tanks 10, 11 rises, and the pressure before and after that becomes Pb> Pa, and the drain tank When the outlet check valves 25 and 26 are opened, the area before the inlet of the drain tank outlet check valves 25 and 26 is a saturated drain, and the state of the drain is equal before and after the check valves 25 and 26. The occurrence of water hammer can be effectively prevented.
[0064]
FIG. 5 is a timing chart of such valve operation according to the present embodiment. As shown in the conventional valve operation timing chart of FIG. 6, conventionally, the conventional drain tank water level adjusting valves 13 and 14 are not restarted. The figure shows a point where the shutter is fully closed while the shutter is fully opened.
[0065]
FIG. 7 shows a restart system according to a second embodiment of the present invention, which includes intermediate drain pipes 27 between drain tank outlet check valves 25 and 26 and service drain tank water level control valves 13 and 14. 28, a bypass line 51 connected to the condenser 16 is connected, a drain valve 52 is interposed in the bypass line 51, and the drain valve 52 is connected to the heating steam valve 20 for restarting. It is characterized in that a control device 53 for forcibly opening the valve for a predetermined time before opening the valve 21 is provided.
[0066]
Therefore, at the time of restart, the drain valve 52 is first opened by the control device 53, so that the intermediate drain pipes 27, 26 between the drain tank outlet check valves 25, 26 and the normal drain tank water level adjusting valves 13, 14 are provided. The condensed drain staying in 28 is discharged to the condenser 16. Since the pressure of the drain decreases from the high saturated drain state to the internal pressure of the condenser 16, the drain pressure decreases with the pressure and the temperature.
[0067]
Then, in this state, when the heating steam valves 20 and 21 are opened to start the moisture separation heater 5, the drain tank outlet check valves 25 and 26 and the normal drain tank water level control valves 13 and 14 are connected. Since the condensed drain flowing into the intermediate drain pipes 27 and 28 is always higher in temperature, the occurrence of water hammer can be effectively prevented.
[0068]
FIG. 8 shows a restart system according to a third embodiment of the present invention, which is connected to the drain tank check valves 25, 26 before the heating steam valves 20, 21 are opened for restart. The ordinary drain tank water level control valves 13 and 14 are operated for a predetermined time until the temperature of the condensed drain staying in the intermediate drain pipes 27 and 28 between the drain tank water level control valves 13 and 14 becomes lower than the fluid temperatures in the pipes before and after the same. The feature is that a control device 61 forcibly closing is provided.
[0069]
Therefore, the control device 61 forcibly closes the common drain tank water level control valves 13 and 14 for a predetermined time and then opens the heating steam valves 20 and 21 to start the moisture separating heater 5. To effectively prevent the occurrence of water hammer since the drive drain flowing into the intermediate drain pipes 27, 28 between the check valves 25, 26 and the service drain tank water level control valves 13, 14 becomes higher in temperature. Can be.
[0070]
That is, as shown in FIG. 9, a water hammer is generated because the temperature T2 of the intermediate drain pipes 27 and 28 is higher than the temperature T1 of the drain tanks 10 and 11 in the conventional starting method. As shown in FIG. 10, since the temperature T1a of the drain tanks 10 and 11 becomes almost equal to the temperature T2a of the intermediate drain pipes 27 and 28 before the restart, water hammer can be prevented.
[0071]
9 and 10, T3 and T3a indicate the temperature of the feed water heater 15 in the conventional example and the present embodiment, and T4 and T4a indicate the pipe temperatures upstream of the emergency drain tank water level valves 18 and 19, respectively. Show. 4, 7, and 8, only the second heater line is shown, and the first heater line is not shown.
[0072]
【The invention's effect】
As described above, the first and second inventions of the present application provide a method of isolating a moisture separation heater from a moisture separation heater device before stopping the supply of heated steam to the heater. Discharge the drain in the tank to the condenser. Therefore, since the heating steam is still supplied to the heater at the time of drain discharge, the drain flush can be prevented beforehand and effectively because the pressure inside the heater is high.
[0073]
However, when the drain tank is emptied by the drain water, the heater and the condenser, which have been separated in pressure by the drain, are equalized through the drain pipe, so that the internal pressure of the heater decreases rapidly.
[0074]
This causes an increase in the amount of heated steam flowing into the heater, increases the flow velocity of steam in the piping and the heater, vibrates these devices and the like, and may cause damage to the devices. Since the flow rate of the heating steam flowing into the heater is controlled to a predetermined value or less, these fears can be effectively and effectively prevented.
[0075]
In addition, since the decrease in the steam temperature at the outlet side of the heater can be controlled to a change rate that does not cause damage to the low-pressure turbine, damage to the low-pressure turbine can be prevented effectively beforehand. That is, it is possible to automatically and safely isolate the operating moisture separator heater as quickly as possible.
[0076]
In the third to sixth aspects of the present invention, when the isolated moisture separation heater is once restarted by the above isolation method or another method, after the isolation, the feed water heater is removed from the drain tank. Drain temperature is reduced by equalizing the drain remaining in the drain flow path up to the internal pressure of the feed water heater or condenser, or by trapping heat in this drain flow path for heat radiation Therefore, the water hammer at the time of restart can be prevented beforehand and effectively. Therefore, the moisture separation heater after isolation can be automatically restarted safely and as quickly as possible.
[0077]
Furthermore, since the seventh invention of the present application includes the isolation system according to the first invention and the restart system according to any of the third to sixth aspects, the isolation and restart of the moisture separation heater can be performed. Can be performed safely and quickly automatically.
[Brief description of the drawings]
FIG. 1 is a block diagram showing control of an embodiment of an isolation system and a method of a moisture separation heater device according to the present invention.
FIG. 2 is a graph showing a valve capacity coefficient of the heated steam valve shown in FIG. 3;
FIG. 3 is a system configuration diagram of an example of a moisture separation heater device to which the present invention is applied.
FIG. 4 is an enlarged view of a main part showing the configuration and operation of one embodiment of a restart system and a method for a moisture separation heater device according to the present invention.
FIG. 5 is a valve operation timing chart of the restart system according to the embodiment of the present invention shown in FIG. 4;
FIG. 6 is a valve operation timing chart of a conventional restart method.
FIG. 7 is an enlarged view of a main part showing a configuration and the like of another embodiment of the restart system according to the present invention.
FIG. 8 is an enlarged view of a main part showing a configuration and the like of still another embodiment of the restart system according to the present invention.
FIG. 9 is a diagram showing temperature distributions at various points when the system is restarted by a conventional restart method.
10 is a diagram showing temperature distributions at various points when the system is restarted by the restart system shown in FIG. 8;
[Explanation of symbols]
1 Moisture separation heater device
3 High-pressure turbine of steam turbine
4 Low pressure turbine
5 Moisture separation heater
6 Moisture heater
7 First heater
8 Second heater
9,10,11 Drain tank
12,13,14 Normal drain tank water level control valve
15 Water heater
16 condenser
17, 18, 19 Emergency drain tank water level control valve
20,21 Heated steam valve
22, 23 Drain piping
24, 25, 26 Drain tank outlet check valve
27, 28 Intermediate drain piping
34a, 34b First and second heater drain tank drain discharge controller
35a, 35b First and second heating steam constant flow controllers
36 Moisture separation heater outlet steam temperature controller

Claims (7)

A moisture separation heater that removes the moisture from the high-pressure turbine by a moisture separator and heats the exhaust steam from a high-pressure turbine to a low-pressure turbine by heating with a heater that passes heated steam;
A heating steam valve for controlling an inflow amount of the heating steam supplied to the heater,
A drain tank that selectively drains water to the feed water heater or the condenser while storing the drain from the heater and the moisture separator, respectively.
In a moisture separation heater device having
Drain drain means for draining the drain in the drain tank for the heater to the condenser,
After the drainage, the heating steam inflow amount flowing into the heater is controlled to a constant value by controlling the opening degree of the heating steam valve to reduce the pressure inside the heating device to a predetermined value or less. Means,
After the heating steam inflow rate constant control, control means for gradually closing and fully closing the heating steam valve so that the steam temperature reduction rate at the outlet of the moisture separation heater is within a predetermined value,
An isolation system for a moisture separation heater device, comprising: A moisture separation heater that removes the moisture from the high-pressure turbine by a moisture separator and heats the exhaust steam from a high-pressure turbine to a low-pressure turbine by heating with a heater that passes heated steam;
A heating steam valve for controlling an inflow amount of the heating steam supplied to the heater,
A drain tank that selectively drains water to the feed water heater or the condenser while storing the drain from the heater and the moisture separator, respectively.
In a moisture separation heater device having
The drain in the drain tank for the heater is drained to the condenser, and after the drain is drained, the amount of heated steam flowing into the heater is controlled to be constant by controlling the degree of opening of the heated steam valve, thereby controlling the heater. After the heating steam inflow rate is controlled to be constant, the heating steam valve is gradually closed so that the steam temperature reduction rate at the outlet of the moisture separation heater becomes within a predetermined value. Isolating the moisture separation heater by completely closing the heater. A moisture separation heater that removes the moisture from the high-pressure turbine by a moisture separator and heats the exhaust steam from a high-pressure turbine to a low-pressure turbine by heating with a heater that passes heated steam;
A heating steam valve for controlling an inflow amount of the heating steam supplied to the heater,
A drain tank that selectively drains water to the feed water heater or the condenser while storing the drain from the heater and the moisture separator, respectively.
In a moisture separation heater device having
After isolating the moisture separation heater, the pressure of the drain stagnating in the drain flow path from the heater drain tank to the feedwater heater is equalized with the internal pressure of the feedwater heater. A restart system for a moisture separation heater device, comprising means for operating the moisture separation heater. A moisture separation heater that removes the moisture from the high-pressure turbine by a moisture separator and heats the exhaust steam from a high-pressure turbine to a low-pressure turbine by heating with a heater that passes heated steam;
A heating steam valve for controlling an inflow amount of the heating steam supplied to the heater,
A drain tank that selectively drains water to the feed water heater or the condenser while storing the drain from the heater and the moisture separator, respectively.
In a moisture separation heater device having
After isolating the moisture separation heater, the pressure of the drain remaining in the drain passage from the drain tank to the feed water heater is equalized with the internal pressure of the condenser, and then the moisture is removed. A restart system for a moisture separation heater device, comprising means for operating the separation heater. A moisture separation heater that removes the moisture from the high-pressure turbine by a moisture separator and heats the exhaust steam from a high-pressure turbine to a low-pressure turbine by heating with a heater that passes heated steam;
A heating steam valve for controlling an inflow amount of the heating steam supplied to the heater,
A drain tank that selectively drains water to the feed water heater or the condenser while storing the drain from the heater and the moisture separator, respectively.
In a moisture separation heater device having
After isolating the moisture separation heater, the drain remaining in the drain flow path from the heater drain tank to the feed water heater is confined in the drain flow path for a predetermined time to release heat, and then the moisture is removed. A restart system for a moisture separation heater device, comprising means for operating the separation heater. A moisture separation heater that removes the moisture from the high-pressure turbine by a moisture separator and heats the exhaust steam from a high-pressure turbine to a low-pressure turbine by heating with a heater that passes heated steam;
A heating steam valve for controlling an inflow amount of the heating steam supplied to the heater,
A drain tank that selectively drains water to the feed water heater or the condenser while storing the drain from the heater and the moisture separator, respectively.
In a moisture separation heater device having
After isolating the moisture separation heater, the temperature of the drain staying in the drain flow path from the heater drain tank to the feedwater heater is reduced, and then the moisture separation heater is operated. Method for restarting the moisture separation heater device. A moisture separation heater device comprising the isolation system according to claim 1 and the restart system according to any one of claims 2 to 5.

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