JPS61201802A - Turbine forced cooling method and its device - Google Patents

Abstract

PURPOSE:To restrain generation of thermal stress of a rotor, a casing etc., by feeding cooling air from a low temperature portion to a high temperature portion of the turbine casing by the exhausting steam ejector of a condenser at the time of turbine stop. CONSTITUTION:In a power plant composed of turbines 4, 8, 10, a steam type air extractor 12 is actuated to make a condenser 11 suck air by a vacuum break valve 17 at the time of plant stop. This time, valves 13, 22-25 are fully opened and those 14-16, 26 are fully closed. The air cools a turbine casing from the low pressure turbine 10 exhaust side and reaches a cross over pipe 9, a medium pressure turbine 8 and the valve 23 while being warmed, and a portion of the air reaches a pipe 18a and the valve 22 via the exhaust unit of a high pressure turbine 4 from the condenser 11 and discharged from an ejector 12 into atmosphere through a cooler 21 and valves 24, 25. Then, cooling is made from the low temperature portion to the high temperature portion, and thermal stress can be restrained.

Description

【発明の詳細な説明】 〔発明の利用分野〕 本発明は火力発電プラント設備の停止時に、タービンケ
ーシングを冷却するタービン強制冷却法及びその装置に
関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a forced turbine cooling method and device for cooling a turbine casing during shutdown of thermal power plant equipment.

〔発明の背景〕[Background of the invention]

従来の火力発電プラント設備は、タービンを停止し亀定
検もしくは緊急停止によりタービンの分解点検を行う場
合、タービン停止解列後、自然冷却によりタービンケー
シングτは度が作業員が接触できる程度の温度（約１５
０ｔ：’〜１８　ＱＧ）になるまで４〜５日を要してい
る。特に、高圧タービンは高温蒸気ｆｔ使用しているた
め、停止後すぐにはタービンケーシング温度は下がらず
、作業員が触れることすらできない。タービンは停止中
これを分解して内部を点検する必要があるが、冷却を自
然冷却に任せると４〜５日間の作業待ちとなり、長いも
のでは１週間も待たなければならないというのが実情で
ある。In conventional thermal power plant equipment, when the turbine is stopped and the turbine is overhauled due to a periodic inspection or an emergency shutdown, after the turbine is stopped and disassembled, the turbine casing τ is cooled down to a temperature that can be touched by workers due to natural cooling. (about 15
It takes 4 to 5 days to reach 0t:'~18 QG). In particular, since high-pressure turbines use high-temperature steam, the temperature of the turbine casing does not drop immediately after it is stopped and cannot even be touched by workers. While the turbine is stopped, it is necessary to disassemble it and inspect the inside, but the reality is that if you leave the cooling to natural cooling, you will have to wait 4 to 5 days for the work to be done, and in some cases you will have to wait as long as a week. .

これは、できるだけ早期にタービンを再作動させて火力
発電所等を再開する必要のある場合、大いに問題である
。よって、分解作業着手までの待時間を極力短縮すべく
、タービン内部から強制冷却を行う方法が考えられてい
る。この方法においては、停止後タービン内部に空気を
送入して冷却するのであるが、提案されている従来の方
法は、例えば実公昭５２−５７２８１号公報に見られる
如く冷却用の空気を蒸気の流れと同一方向から流す構成
、即ち該空気を蒸気通路の上流がわからタービン内に送
気する構成をとるものである。This is a big problem when it is necessary to restart a thermal power plant etc. by restarting the turbine as soon as possible. Therefore, in order to reduce the waiting time until the start of disassembly work as much as possible, methods are being considered in which forced cooling is performed from inside the turbine. In this method, air is introduced into the turbine to cool it after the turbine is stopped. However, in the conventional method proposed, for example, as seen in Japanese Utility Model Publication No. 52-57281, the cooling air is replaced with steam. The structure is such that the air flows from the same direction as the steam flow, that is, the air is sent into the turbine by knowing the upstream side of the steam passage.

ところが、従来のかかる方法では、以下述べる如き数々
の問題点がある。However, this conventional method has many problems as described below.

即ち、ケーシング温度と大きな温度差のある冷たい空気
を送入すると、タービンの冷却速度を早めることができ
るものの、今まで高温であったケーシングが急激に冷却
されるためタービン各部を構成する部片に大きな熱り力
が発生し材料劣化、ひいてはクラックが生ずる危険性が
ある。かつ、急冷によって先ず熱容量の小さな部片が収
縮することになり、キーのゆるみが生じたり、回転体と
静止体とに伸び差が生じて両者が接触し、接触摺損を起
こす原因となる。In other words, by introducing cold air with a large temperature difference from the casing temperature, it is possible to speed up the cooling rate of the turbine, but the casing, which has been at a high temperature until now, is rapidly cooled, causing damage to the parts that make up each part of the turbine. There is a risk that large heating forces will be generated, leading to material deterioration and even cracks. In addition, due to rapid cooling, parts with a small heat capacity shrink first, causing the key to become loose or a difference in expansion between the rotating body and the stationary body to come into contact with each other, causing contact damage.

一方、上記問題点を軽減すべくケーシング温度と余り差
のない比較的高温の空気を送入すると、タービン冷却の
効果は小さく、冷却期間短縮という当初の目的が達成さ
れなくなる。かつ、このような高温空気を送入するため
には、蒸気通路の上流側は特に高温となっているので、
かかる温度近くにまで空気を予熱しておく必要があるわ
けであり、その予熱が容易でないという問題もある。On the other hand, if air at a relatively high temperature that is not significantly different from the casing temperature is introduced in order to alleviate the above-mentioned problems, the turbine cooling effect will be small and the original purpose of shortening the cooling period will not be achieved. In addition, in order to feed such high-temperature air, the upstream side of the steam passage is particularly high temperature, so
It is necessary to preheat the air to near this temperature, and there is also the problem that preheating is not easy.

更に、蒸気通路の上流がわから冷却用空気を送入するた
めには、その上流がわ部分は主蒸気のためきわめて高温
高圧であるので、それに十分耐えられる送気手段を用い
る必要がある。この高温高圧状態を抽気により緩和しよ
うとする場合でも、そのための弁や通気管はそれに耐え
る必要性があり、コストアップの要因となる。Furthermore, in order to introduce cooling air into the upstream part of the steam passage, it is necessary to use an air supply means that can sufficiently withstand the main steam, which is at an extremely high temperature and pressure. Even if this high temperature and high pressure state is to be alleviated by air extraction, the valves and vent pipes needed to withstand this need to be able to withstand it, which increases costs.

第３図は、強制冷却装置を持たない分類の発電プラント
を示している。FIG. 3 shows a power plant classified without forced cooling.

第３図において、ボイラ１より発生した主蒸気は、主蒸
気配管２、主蒸気止め弁（以下Ｍ８Ｖ）３を通り高圧タ
ービン４で仕事をし、低温再熱管５ｔ−介し、再熱器６
へ導かれ再加熱された再熱蒸気は、再熱蒸気止め弁（以
下几５Ｖ）７より中圧タービン８、クロスオーバ管９、
低圧タービン１０より復水器１１へと回収される。ここ
で、主蒸気の温度を高圧タービン４の排気部、つまり低
温再熱管５の部分で湿りとならない温度まで低下させて
高圧タービンを冷却させる。そして、再熱器６を経た蒸
気は、中圧タービン８下流へと流れることになる。In Fig. 3, main steam generated from a boiler 1 passes through a main steam pipe 2, a main steam stop valve (hereinafter referred to as M8V) 3, works in a high pressure turbine 4, passes through a low temperature reheat pipe 5t, and then passes through a reheater 6.
The reheated steam guided and reheated is passed through a reheat steam stop valve (hereinafter referred to as 5V) 7 to an intermediate pressure turbine 8, a crossover pipe 9,
It is recovered from the low pressure turbine 10 to the condenser 11. Here, the temperature of the main steam is lowered to a temperature that does not cause dampness at the exhaust section of the high-pressure turbine 4, that is, at the low-temperature reheat pipe 5, to cool the high-pressure turbine. The steam that has passed through the reheater 6 then flows downstream of the intermediate pressure turbine 8.

一般に、蒸気温度は５３８Ｃあるいは５６６Ｃで通常運
用され、従来方法による冷却運転時は、蒸気温度全１０
０Ｃ程度の温度降下しか得られず大きな効果は期待でき
なかった。また、プラント運転時、通常温度と異ったボ
イラ運転、タービン運転を行うため、これにかかわる監
視、制御をおこたると伸び差、熱りカ、ケーシング変形
、振動大等による異膚が発生する可能性があり、安定性
、信頼性の面で非常に不安定である。Generally, the steam temperature is normally operated at 538C or 566C, and during cooling operation using the conventional method, the steam temperature is 538C or 566C.
Only a temperature drop of about 0C was obtained, and no great effect could be expected. In addition, during plant operation, boiler and turbine operations are performed at temperatures different from normal temperatures, so if monitoring and control are not performed, abnormalities may occur due to differential expansion, heating force, casing deformation, large vibrations, etc. It is very unstable in terms of stability and reliability.

そして、緊急停止時には、冷却操作が行えず、本発明の
主目的の一つである、緊急対策の早期実施による稼動率
向上に全く対応できないものである。In addition, during an emergency shutdown, cooling operations cannot be performed, and it is completely impossible to improve the operating rate by implementing emergency measures early, which is one of the main objectives of the present invention.

〔発明の目的〕[Purpose of the invention]

本発明の目的は、上記従来例の諸問題を解消して、クラ
ックやその他の損傷を生ぜしめることなくしかも急速な
タービンの冷却をなし得、かつ複雑な制御や大規模な系
統改造ｔ−要することなく、比較的安価にターピ／の強
制冷却法及びその装置を提供するととＫある。It is an object of the present invention to solve the problems of the above-mentioned conventional examples, to achieve rapid cooling of the turbine without causing cracks or other damage, and to provide a system that does not require complicated control or large-scale system modification. We hope to provide a forced cooling method and device for turrets at a relatively low cost.

〔発明の概要〕[Summary of the invention]

上記目的を達成するため、本発明は、ボイラから主蒸気
止め弁を通り高圧タービンを経て再熱器へ、そして再熱
蒸気止め弁を通り中玉タービン、低圧タービンより復水
器へと蒸気が回収され、また高圧タービン排気部と復水
器とを結ぶ配管系統を有するプラント設備に対し、ター
ビンの強制冷却法を提供するものである。In order to achieve the above object, the present invention provides steam that flows from the boiler through the main steam stop valve, through the high pressure turbine, to the reheater, through the reheat steam stop valve, to the medium turbine turbine, and from the low pressure turbine to the condenser. It provides a forced turbine cooling method for plant equipment that is recovered and has a piping system connecting the high pressure turbine exhaust and the condenser.

〔発明の実施例〕[Embodiments of the invention]

以下、本発明の一実施例を第１図および第２図により説
明する。An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

プラント通常運転中は以下となる。During normal plant operation, the following will occur.

ボイラ１より発生した主蒸気は、主蒸気管２、ＭＳＶ３
、高圧タービン４、低温再熱管５ｔ−通り再熱器６を経
て、Ｒ，ＳＶ７、中圧タービン８、クロスオーバ管９、
低圧タービン１０ｔ−通り復水器１１へ到る。そして、
復水器１１には、一般に蒸気エゼクタ−１２が設置され
真空度を保持している。また、蒸気加減弁（記載せず）
が閉した場合には、配管６０に設けたベンチレータ弁１
３が開し、几ＳＶ７のインターセプト弁（記載せず）が
閉した場合には、ブローダウン弁１４が開し、各各復水
器１１へと接続され高圧タービン４内の蒸気を排出する
。さらにＭ８Ｖ３の下流、　Ｒ，ＳＶ７の下流に各々ド
レン弁１５．１６があり、運転中は全閉しており、起動
停止時にはドレンを復水器１１へ排出する。タービン停
止後の真空破壊時は、蒸気エゼクタ−１２を停止させ真
空破壊弁１７ｔ−開して行う。The main steam generated from boiler 1 is transferred to main steam pipe 2 and MSV 3.
, high pressure turbine 4, low temperature reheat pipe 5t-through reheater 6, R, SV 7, intermediate pressure turbine 8, crossover pipe 9,
The low pressure turbine 10t reaches the condenser 11. and,
A steam ejector 12 is generally installed in the condenser 11 to maintain the degree of vacuum. Also, steam control valve (not listed)
is closed, the ventilator valve 1 provided in the piping 60
3 opens and an intercept valve (not shown) of the SV 7 closes, the blowdown valve 14 opens and is connected to each condenser 11 to discharge the steam in the high pressure turbine 4. Furthermore, there are drain valves 15 and 16 downstream of M8V3 and downstream of R and SV7, which are fully closed during operation and discharge drain to the condenser 11 when starting or stopping. When the vacuum is broken after the turbine is stopped, the steam ejector 12 is stopped and the vacuum break valve 17t is opened.

ここで、ドレン弁１５，１６の上流側よシ蒸気式空気抽
出器１２の入口へ結ぶ配管１８　ａ、　ｔ９ａ。Here, piping 18a, t9a connects the upstream side of the drain valves 15, 16 to the inlet of the steam air extractor 12.

２０を追設し必要に応じクーラ２１を設置する。20 is additionally installed, and a cooler 21 is installed as necessary.

この部分が本発明によるタービン冷却法を可能とするも
のであり、プラント運転中は、弁２２゜２３．２４，２
５は閉めておく。蒸気エゼクタ−１２の大口弁２６は開
けておく。This part enables the turbine cooling method according to the present invention, and during plant operation, the valves 22, 23, 24, 2
5 is closed. The large mouth valve 26 of the steam ejector 12 is left open.

第２図によシ、プラント停止時の本発明による具体的な
説明を以下行う。Referring to FIG. 2, a detailed explanation of the present invention when the plant is stopped will be given below.

ボイラ１および再熱器６からの蒸気流入をしゃ断するＭ
８Ｖ３および凡８Ｖ７は全閉しており、べ／チレータ弁
１３およびブローダウン弁１４は全開になるが、本発明
による空気冷却を行えるべく第４図に示すインタブロッ
クにて第２図の各弁の開閉操作を実施する。操作手順と
して、油ポンプを用いてタービンの軸受油および制御油
を確保し、ホット状態でのタービンの曲り防止の九めタ
ーニングを行い、この状態でタービンセットし、蒸気加
減弁（記載せず）、ベンチレータ弁１３を全開とし、ブ
ローダウン弁１４、ドレン弁１５゜１６を全閉とする。M to cut off steam inflow from boiler 1 and reheater 6
8V3 and 8V7 are fully closed, and the vent/tilator valve 13 and blowdown valve 14 are fully open, but in order to perform air cooling according to the present invention, the valves shown in FIG. 2 are closed at the interblock shown in FIG. 4. Perform opening/closing operations. The operating procedure is to secure bearing oil and control oil for the turbine using an oil pump, perform a ninth turn to prevent the turbine from bending in a hot state, set the turbine in this state, and install the steam control valve (not shown). , the ventilator valve 13 is fully opened, and the blowdown valve 14 and drain valves 15 and 16 are fully closed.

そして弁２２，２３，２４゜２５を開き、蒸気エゼクタ
−１２の大口弁２６を全閉とし、クーラ２１が使用でき
る状態とする。Then, the valves 22, 23, 24 and 25 are opened, and the large mouth valve 26 of the steam ejector 12 is fully closed, so that the cooler 21 can be used.

以上の操作により準備が完了するが、この状態ではボイ
ラ１および再熱器６に残圧があるのでＭＳＶ３およびＲ
８Ｖ７は開いてはならない。Preparation is completed by the above operations, but in this state there is residual pressure in boiler 1 and reheater 6, so MSV3 and R
8V7 must not be opened.

蒸気式空気抽出器１２を作動させ、真空破壊弁１７より
空気を復水器１１へ吸い込む。この場合、真空破壊弁１
７には、フィルタが付いているのが一般的であり、これ
を利用することでゴミの混入防止が行える。そして、低
圧タービン１０排気側よりタービンケーシングを冷却し
、空気は次第にウオーミングされながらクロスオーバ管
９、中圧タービン８ｆｃ冷却し、Ｒ，ＳＶ７のドレン弁
１６前へ接続の配管１９より弁２３へ、また一部は復水
器１１よりベンチレータ弁１３を経て高圧タービン４排
気部より、ＭＳＶ３のドレン弁１５前へ接続の配管１８
Ｍより弁２２へ到り、さらに配管２０、クーラ２１およ
び弁２４，２５を経て蒸気エゼクタ−１２より大気へ放
出される。The steam air extractor 12 is operated and air is sucked into the condenser 11 through the vacuum breaker valve 17. In this case, vacuum breaker valve 1
7 is generally equipped with a filter, which can be used to prevent dust from entering. Then, the turbine casing is cooled from the exhaust side of the low-pressure turbine 10, and the air is gradually warmed while cooling the crossover pipe 9 and the intermediate-pressure turbine 8fc, and then flows from the pipe 19 connected to the front of the drain valve 16 of R and SV7 to the valve 23. In addition, a part of the pipe 18 connects from the condenser 11 through the ventilator valve 13 and from the high pressure turbine 4 exhaust section to the front of the drain valve 15 of the MSV 3.
The steam reaches the valve 22 from M, passes through the piping 20, the cooler 21, and the valves 24, 25, and is discharged from the steam ejector 12 to the atmosphere.

本発明による冷却空気の流れは、冷却空気と接するケ・
−シ／グが低温部から高温部へと移るので、上杵する空
気温度に丁度見会った冷却が、はぼ全域に渡り可能であ
り、ケーシングと空気との温度差の過度な冷却が回避で
きる。The flow of cooling air according to the present invention is
- Since the gas moves from the low temperature area to the high temperature area, cooling can be achieved over the entire area to match the temperature of the air passing through the upper punch, avoiding excessive cooling due to the temperature difference between the casing and the air. can.

第５図に、タービン冷却特性を示すが、本発明にＬれば
従来の自然冷却６１では約６日間要していたものが、強
制冷却６２では約３日間となり、３日間程度の短縮が可
能でおる。Figure 5 shows the turbine cooling characteristics, and if the present invention is applied, the conventional natural cooling 61 would require about 6 days, but the forced cooling 62 would take about 3 days, making it possible to shorten the time by about 3 days. I'll go.

冷却時に配慮する事項としては、過度な冷却および高圧
タービンと中低圧タービンとの冷却のアンバランスが考
えられるので、ケージング温度降下を調節する必要があ
る。冷却空気を循環させる蒸気エゼクタ−は一定速度で
運転されるので、高圧タービン、中低圧タービン全体の
冷却降下率は弁２４にて空気流量の調節を行い、高圧タ
ービン側の冷却降下率調節は弁２２にて、中低圧タービ
ン９１Ｊは弁２３にて空気流量調節することで円滑な冷
却が行える。Issues to consider during cooling include excessive cooling and unbalanced cooling between the high-pressure turbine and the medium-low pressure turbine, so it is necessary to adjust the caging temperature drop. Since the steam ejector that circulates cooling air is operated at a constant speed, the cooling drop rate of the entire high-pressure turbine and medium-low pressure turbine is adjusted by the valve 24, and the cooling drop rate of the high-pressure turbine side is controlled by the valve 24. At 22, the medium and low pressure turbine 91J can be smoothly cooled by adjusting the air flow rate with the valve 23.

一般に、高圧タービンケーシング温度は高圧初段後内壁
、中圧タービンケーシング温度は中圧タービン内壁を監
視することになり、これらの個所は通常計測制御に使用
されている。Generally, the high-pressure turbine casing temperature is monitored on the inner wall after the high-pressure first stage, and the intermediate-pressure turbine casing temperature is monitored on the inner wall of the intermediate-pressure turbine, and these locations are normally used for measurement control.

高圧タービン４および中圧タービン８のケーシング温度
を温度検出器５１．５２で検知し、それらの信号５３．
５４を演算装置５５に入力し、タービンの冷却の度合い
にエリ弁２４を開閉し、蒸気式空気抽出器１２の空気流
量ｔ−量調節ケーシングが設定温度降下降より大の時は
弁２４を絞り、逆の場合は弁２４を開操作させる。）、
また高圧タービンあるいは中圧タービンが冷え過ぎる場
合は、高圧タービン４に対しては弁２２、中圧タービン
８に対しては弁２３ｆ：絞ることになり、逆の場合は、
各々につき開操作することになる。The casing temperatures of the high-pressure turbine 4 and the intermediate-pressure turbine 8 are detected by temperature detectors 51.52, and their signals 53.
54 is input to the arithmetic unit 55, the ERI valve 24 is opened or closed depending on the degree of cooling of the turbine, and the valve 24 is throttled when the air flow rate t-amount adjustment casing of the steam type air extractor 12 is greater than the set temperature drop. In the opposite case, the valve 24 is opened. ),
Also, if the high pressure turbine or intermediate pressure turbine becomes too cold, the valve 22 for the high pressure turbine 4 and the valve 23f for the intermediate pressure turbine 8 will be throttled;
The opening operation will be performed for each one.

尚、フランジ短管１８ｂ、１９ｂは運転中は空気吸込に
より真空破壊等の支障をきたすために取外しておき閉止
７ランジを取付は安全防止対策を行う。Note that the flange short pipes 18b and 19b are removed during operation to avoid problems such as vacuum breakage due to air intake, and the closing 7 lunges are installed as a safety precaution.

以上の説明による強制冷却法の制御ブロック図を示した
一例を第６図に示す。An example of a control block diagram of the forced cooling method explained above is shown in FIG. 6.

本発明によれば、従来方式にくらべ冷却日数を約３日間
短縮することが可能であり、より安全かつ容易にタービ
ンの強制冷却が行える。According to the present invention, it is possible to shorten the cooling time by about 3 days compared to the conventional method, and forced cooling of the turbine can be performed more safely and easily.

〔発明の効果〕〔Effect of the invention〕

本発明によれば、既設の蒸気式空気抽出器を使用し、タ
ービンのケーシング低温部から高温部へと蒸気流とけ逆
に、空気を流すのでサーマルショックが極めて小さく、
これによるロータ、ケーシング等の熱応力、熱変形、伸
び差異常等が回避可能であり、高圧タービンと中低圧タ
ービンを別々の系統で冷却するので、各々の冷却調整が
可能であ怜、非常に効率の良いケーシング冷却が実施で
きる。According to the present invention, an existing steam-type air extractor is used to flow air from the low-temperature part of the turbine casing to the high-temperature part in the opposite direction of the steam flow, so thermal shock is extremely small.
This makes it possible to avoid thermal stress, thermal deformation, abnormal expansion, etc. of the rotor, casing, etc., and since the high-pressure turbine and medium-low pressure turbine are cooled by separate systems, it is possible to adjust the cooling of each, which is very convenient. Efficient casing cooling can be performed.

本発明の応用としては、高中圧を同じ系統で冷却した場
合には、再熱器という熱容量の非常に大きなものを通す
と、空気温度が大変高くなり冷却時間が増大するだけで
なく高圧タービン自体を、冷却以前に昇温させてしまい
伸び差、変形等を引き起こすことも懸念されるので、本
発明の実施例の如く、高圧タービンと中低圧タービンを
分離して冷却する方式が良い。As an application of the present invention, when high and medium pressures are cooled in the same system, if the air is passed through a reheater, which has a very large heat capacity, the air temperature will become very high, which will not only increase the cooling time but also cause the high pressure turbine itself to cool. Since there is a concern that the temperature of the turbine may be raised before cooling, causing differential elongation, deformation, etc., it is better to cool the high-pressure turbine and the medium-low pressure turbine separately, as in the embodiment of the present invention.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は、本発明を実施した場合のプラント系統図、第
２図は、本発明を実施した場合のプラント系統図、第３
図は、従来のプラント系統図、第４ｒｇＪは、本発明に
よるタービン強制冷却前の準備となるインタブロック線
図実施例、第５図は、タービン冷却特性、第６図は、本
発明による制御ブロック線図である。 １・・・ボイラ、２・・・主蒸気管、３・・・主蒸気止
め弁、４・・・高圧タービン、５・・・低温再熱管、６
・・・再熱器、７・・・再熱蒸気止め弁、Ｓ・・・中圧
タービン、９・・・クロスオーバ管、１０・・・低圧タ
ービン、１１・・・復水器、１２・・・蒸気式空気抽出
器、１３・・・ベンチレータ弁、１４・・・ブローダウ
ン弁、１５・・・ドレン弁、１６・・・ドレン弁、１７
・・・真空破壊弁、１８ａ。 １８ｂ・・・配管、１９ａ、１９ｂ・・・配管、２０・
・・配管、２１・・・クーラ、２２・・・弁、２３・・
・弁、２４・・・弁、２５・・・弁、２６・・・弁、５
１・・・温度検出器、５２・・・温度検出器、５３・・
・信号、５４・・・信号、５５・・・演算装置、５６・
・・弁開度信号、５７・・・弁開度信号、５８・・・弁
開度信号、６１・・・自然冷却による高圧筒１股内壁温
度、６２・・・強制冷却による高圧筒１股内壁温度、６
３・・・開放点検可能温度。Figure 1 is a plant system diagram when the present invention is implemented, Figure 2 is a plant system diagram when the present invention is implemented, and Figure 3 is a plant system diagram when the present invention is implemented.
The figure is a conventional plant system diagram, 4th rgJ is an example of an interblock diagram for preparation before forced turbine cooling according to the present invention, FIG. 5 is a turbine cooling characteristic, and FIG. 6 is a control block according to the present invention. It is a line diagram. DESCRIPTION OF SYMBOLS 1... Boiler, 2... Main steam pipe, 3... Main steam stop valve, 4... High pressure turbine, 5... Low temperature reheat pipe, 6
... Reheater, 7... Reheat steam stop valve, S... Medium pressure turbine, 9... Crossover pipe, 10... Low pressure turbine, 11... Condenser, 12... ... Steam air extractor, 13... Ventilator valve, 14... Blowdown valve, 15... Drain valve, 16... Drain valve, 17
...Vacuum breaker valve, 18a. 18b...Piping, 19a, 19b...Piping, 20.
...Piping, 21...Cooler, 22...Valve, 23...
・Valve, 24...Valve, 25...Valve, 26...Valve, 5
1...Temperature detector, 52...Temperature detector, 53...
・Signal, 54... Signal, 55... Arithmetic device, 56.
... Valve opening signal, 57... Valve opening signal, 58... Valve opening signal, 61... Inner wall temperature of one crotch of high pressure cylinder due to natural cooling, 62... One crotch of high pressure cylinder due to forced cooling. Inner wall temperature, 6
3...Temperature that allows open inspection.

Claims (1)

【特許請求の範囲】 １、プラント停止時に冷却用の空気を復水器の排気用蒸
気エゼクターによりタービン内に送入してタービンケー
シングを冷却するタービンの冷却法であって、前記冷却
用の空気としてタービンケーシングの温度よりも低い温
度の空気を用いるとともに、該空気はタービン膨張段の
下流がわから送入することを特徴とするタービン強制冷
却法。 ２、プラント停止時に冷却用の空気を復水器の排気用蒸
気エゼクターによりタービン内に送入してタービンケー
シングを冷却するタービンの冷却装置であって、タービ
ンを停止し、タービンの分解点検を行う場合、高圧ター
ビン排気部と復水器を結ぶ配管（６０）および前記高圧
タービン入口部と前記復水器の蒸気エゼクターとを結ぶ
配管（１８ａ、１８ｂ、２０）および中圧タービン入口
部と前記蒸気エゼクターとを結ぶ配管（１９ａ、１９ｂ
、２０）を追設し、前記プラント停止時の前記タービン
ターニング中に前記蒸気エゼクターを用いて、前記復水
器に設置されている真空破壊弁（１７）より空気を送入
し、前記配管（６０）を通り前記高圧タービン排気から
前記高圧タービン入口部へ、また前記復水器より低圧タ
ービン内を蒸気の流れとは逆に流れ、前記中圧タービン
排気から前記中圧タービン入口部を経て、配管（１９ａ
、１９ｂ、２０）を介して前記エゼクターへ空気を導い
てタービンケーシングを強制冷却することを特徴とする
タービン強制冷却装置。 ３、特許請求の範囲第２項記載において、更に前記配管
（１８ａ、１９ａ）の各々の途中に弁を設置し、高圧タ
ービンおよび中圧タービンのケーシング内壁温度を検出
する手段を設け、これらの検出手段によりケーシング温
度を目標の温度まで冷却すべく、タービンのケーシング
内壁温度の変化に対応して前記配管に設けた各々の弁を
開閉調節し、タービンを冷却することを特徴とするター
ビン強制冷却装置。[Scope of Claims] 1. A turbine cooling method that cools a turbine casing by sending cooling air into the turbine through an exhaust steam ejector of a condenser when the plant is stopped, wherein the cooling air A turbine forced cooling method characterized in that air having a temperature lower than that of the turbine casing is used as the turbine casing, and the air is introduced downstream of the turbine expansion stage. 2. A turbine cooling device that cools the turbine casing by sending cooling air into the turbine through the exhaust steam ejector of the condenser when the plant is stopped, and the turbine is stopped and the turbine is overhauled and inspected. In this case, a pipe (60) connecting the high-pressure turbine exhaust section and the condenser, a pipe (18a, 18b, 20) connecting the high-pressure turbine inlet section and the steam ejector of the condenser, and a pipe (18a, 18b, 20) connecting the high-pressure turbine inlet section and the steam ejector, and the intermediate-pressure turbine inlet section and the steam Piping connecting to the ejector (19a, 19b
, 20) is additionally installed, and during the turbine turning when the plant is stopped, the steam ejector is used to feed air from the vacuum breaker valve (17) installed in the condenser, and the piping ( 60) from the high-pressure turbine exhaust to the high-pressure turbine inlet, and from the condenser to the low-pressure turbine in a direction opposite to the flow of steam, and from the intermediate-pressure turbine exhaust to the intermediate-pressure turbine inlet; Piping (19a
, 19b, 20) to forcefully cool the turbine casing by guiding air to the ejector. 3. In claim 2, furthermore, a valve is installed in the middle of each of the pipes (18a, 19a), and means for detecting the inner wall temperature of the casing of the high-pressure turbine and the intermediate-pressure turbine is provided. A turbine forced cooling device characterized in that the turbine is cooled by adjusting the opening and closing of each valve provided in the piping in response to changes in the temperature of the inner wall of the casing of the turbine in order to cool the casing temperature to a target temperature. .