JPH0422001Y2 - - Google Patents

Description

【考案の詳細な説明】 〔考案の属する技術分野〕 本考案は、蒸気タービンの復水器に併置されタ
ービン排気中の不凝縮性ガスを抽出する蒸気エゼ
クタからの排気を冷却、凝縮する蒸気エゼクタ冷
却器に関する。[Detailed description of the invention] [Technical field to which the invention pertains] The invention relates to a steam ejector that cools and condenses exhaust gas from a steam ejector that is placed alongside a steam turbine condenser and extracts noncondensable gas from the turbine exhaust gas. Regarding coolers.

〔従来技術とその問題点〕[Prior art and its problems]

蒸気タービンプラント特に地熱発電プラントに
使用される復水タービンは復水器を備え、蒸気タ
ービンの排気は復水器に導かれて復水にされると
とも排気中に含まれる不凝縮性ガスは併置されて
る蒸気エゼクタにより吸引排出されるようになつ
ている。なお蒸気エゼクタからの排気は一般に直
接接触式の冷却器に導かれ、外部から供給される
冷却水に直接接触させ復水として外部に回収又は
廃棄される。以下従来例の図面に基づいて説明す
る。第４図は従来の蒸気エゼクタ冷却器の断面図
である。 A condensing turbine used in a steam turbine plant, especially a geothermal power plant, is equipped with a condenser, and the exhaust gas of the steam turbine is guided to the condenser and converted into condensate, and the noncondensable gases contained in the exhaust gas are It is designed to be sucked and discharged by a steam ejector located side by side. Note that the exhaust gas from the steam ejector is generally guided to a direct contact cooler, brought into direct contact with cooling water supplied from the outside, and collected or disposed of as condensate outside. A description will be given below based on drawings of a conventional example. FIG. 4 is a cross-sectional view of a conventional steam ejector cooler.

図において、２はステンレス製の円筒状密封容
器の蒸気エゼクタ冷却器で４はその胴壁である。
そしてその頂部にはエゼクタ排気中に含まれる不
凝縮性ガスの放出口６と、胴壁４の下側部にあり
蒸気エゼクタ１の放流口に接続されエゼクタ排気
を送流する排気導管１２の終端が接続される排気
入口７と、底部に復水の排出口８ならびに胴壁４
の上側部には図示しない冷却水源から給水ポンプ
１１の駆動により冷却水を蒸気エゼクタ冷却器２
へ送流する冷却水管１０が接続される冷却水入口
９とがそれぞれ配設されている。その内部には、
平盤状の箱体でその底面に多数の小孔を備え冷却
水を一時的に貯留させるとともに、絶えず底面の
小孔から冷却水を流下させるようになる複数個の
散水トレイ３ａ，３ｂ……３ｎが、胴壁４からそ
の内方へ水平に張り出しかつ上下互い違いに交差
して設けられており、その散水トレイ３ａ，３ｂ
……３ｎによつて蒸気エゼクタ冷却器２の内部を
幾段かに画成するとともに、胴壁４とで該冷却器
２内に蛇行する排気流路５（蛇行矢印）を形成し
ている。また蒸気エゼクタ冷却器２の底部はエゼ
クタ排気の復水を貯留し排出するためのホツトウ
エル１３になつている。さらに排気入口７の配設
位置と反対側でかつエゼクタ排気流を真正面に受
ける領域に、ホツトウエル１３の最高水面から最
下段の散水トレイ３ｎが配設されている高さまで
の間でかつ胴壁４の周長の略1/2の巾に、胴壁４
の内周面の前方にありかつ覆うように配設され、
エゼクタ排気の速度エネルギの低減と胴壁４の保
護及び排気流の案内板の役割りを負うバツフル１
４が配設されている。 In the figure, 2 is a steam ejector cooler of a cylindrical sealed container made of stainless steel, and 4 is its body wall.
At its top, there is a discharge port 6 for non-condensable gas contained in the ejector exhaust gas, and at the end of an exhaust conduit 12, which is located on the lower side of the body wall 4 and is connected to the discharge port of the steam ejector 1, through which the ejector exhaust gas flows. an exhaust inlet 7 to which is connected, a condensate outlet 8 at the bottom and a body wall 4
On the upper side, cooling water is supplied from a cooling water source (not shown) to a steam ejector cooler 2 by driving a water supply pump 11.
A cooling water inlet 9 to which a cooling water pipe 10 is connected is provided. Inside it,
A plurality of watering trays 3a, 3b, which are flat box-like bodies with many small holes on the bottom surface, temporarily store cooling water, and allow the cooling water to constantly flow down from the small holes on the bottom surface... 3n are provided horizontally extending inward from the trunk wall 4 and intersecting vertically alternately, and the watering trays 3a, 3b
. . 3n defines the interior of the steam ejector cooler 2 into several stages, and the body wall 4 forms an exhaust passage 5 (indicated by a meandering arrow) that snakes inside the cooler 2. The bottom of the steam ejector cooler 2 is a hot well 13 for storing and discharging condensate from the ejector exhaust gas. Further, in an area opposite to the location where the exhaust inlet 7 is disposed and directly receiving the ejector exhaust flow, there is a section between the highest water level of the hot well 13 and the height where the lowest watering tray 3n is disposed, and the body wall 4. The trunk wall 4 has a width approximately 1/2 of the circumference of
is located in front of and covers the inner peripheral surface of the
Batsuful 1, which plays the role of reducing the velocity energy of ejector exhaust, protecting the body wall 4, and acting as a guide plate for the exhaust flow
4 are arranged.

このように構成される蒸気エゼクタ冷却器２に
給水ポンプ１１を駆動して、図示しない冷却水源
からの冷却水を冷却水管１０を介して冷却水入口
９へ送り、最上段の散水トレイ３ａへ供給する
と、冷却水は散水トレイ３ａの底板の小孔から流
下し、下段の散水トレイ３ｂへと流れ、さらに順
次下段の散水トレイを介しホツトウエル１３へ流
下して行く、従つて散水トレイ間及び最下段の散
水トレイ３ｎとホツトウエル１３の水面との間に
は冷却水柱が形成されている。 The water supply pump 11 is driven to the steam ejector cooler 2 configured as described above, and cooling water from a cooling water source (not shown) is sent to the cooling water inlet 9 via the cooling water pipe 10, and is supplied to the top watering tray 3a. Then, the cooling water flows down from the small hole in the bottom plate of the watering tray 3a, flows to the lower watering tray 3b, and then sequentially flows down to the hot well 13 via the lower watering tray. A cooling water column is formed between the water spray tray 3n and the water surface of the hot well 13.

このような状態の蒸気エゼクタ冷却器２内へ蒸
気エゼクタ１を駆動して不凝縮性ガスを含むエゼ
クタ排気を排気導管１２及び排気入口７を介して
送入すると、エゼクタ蒸気は排気流路５の矢印に
従つて蛇行しながら器内を上昇し、エゼクタ排気
中の蒸気は器内に形成されている冷却水柱に接触
し凝縮され復水となり冷却水と一緒にホツトウエ
ル１３に貯留するとともに、該排気に含まれてい
た不凝縮性ガスは冷却器２の頂部の放出口６を介
して大気中に放散される。一方ホツトウエル１３
に貯留されてる冷却水と復水の混合水は排出口８
を介し図示しない管路を介し冷却水源へ回収され
たり、河川に直接放流される。 When the steam ejector 1 is driven into the steam ejector cooler 2 in such a state and ejector exhaust gas containing non-condensable gas is sent through the exhaust conduit 12 and the exhaust inlet 7, the ejector steam flows into the exhaust flow path 5. The steam in the ejector exhaust rises in the vessel while meandering according to the arrow, and the steam in the ejector exhaust comes into contact with the cooling water column formed in the vessel, condenses, becomes condensate, and is stored in the hot well 13 together with the cooling water, and the steam is The non-condensable gas contained in the cooler 2 is dissipated into the atmosphere through the outlet 6 at the top of the cooler 2. On the other hand, Hotwell 13
The mixed water of cooling water and condensate stored in
The water is collected through a pipe (not shown) to a cooling water source or directly discharged into a river.

このように蒸気エゼクタ１からのエゼクタ排気
を冷却、凝縮する際、該排気の蒸気温度のため蒸
気エゼクタ２の胴壁４の温度は60〜100℃に加熱
される。 When the ejector exhaust gas from the steam ejector 1 is cooled and condensed in this manner, the temperature of the body wall 4 of the steam ejector 2 is heated to 60 to 100° C. due to the steam temperature of the exhaust gas.

ところで蒸気エゼクタ冷却器２は耐食性の点か
ら応力腐蝕割れ感受性の低い材料であるステンレ
ス鋼で作られているが、地熱蒸気のように腐蝕性
気体を含み特にその中の硫化水素が前記の胴壁４
の温度条件と相俟つて応力腐蝕媒体として作用し
応力腐食割れが発生しやすくなる。この場合従来
の経験によれば排気入口７から流入するエゼクタ
排気が直接当るバツフル１４やその後背部に位置
する胴壁部分に応力腐食割れを生ずるという問題
があつた。 By the way, the steam ejector cooler 2 is made of stainless steel, which is a material with low stress corrosion cracking susceptibility in terms of corrosion resistance. 4
Coupled with the temperature conditions, it acts as a stress corrosion medium, making stress corrosion cracking more likely to occur. In this case, according to conventional experience, there has been a problem in that stress corrosion cracks occur in the buttful 14 and the body wall portion located behind it, which are directly hit by the ejector exhaust gas flowing in from the exhaust inlet 7.

なお応力腐食割れの防止対策として溶接や加工
による残留応力を熱処理によつて軽減させること
でも防止できるが、本蒸気エゼクタ冷却器の構造
では応力除去のための熱処理が難かしいため、他
の方法について検討する必要があつた。 Stress corrosion cracking can also be prevented by heat treatment to reduce the residual stress caused by welding or processing, but the structure of this steam ejector cooler makes heat treatment difficult to remove stress, so other methods are not recommended. I needed to consider it.

〔考案の目的〕[Purpose of invention]

本考案は、前述の点に鑑み応力腐食割れが発生
しない構造の蒸気エゼクタ冷却器を提供すること
を目的とする。 SUMMARY OF THE INVENTION In view of the above points, an object of the present invention is to provide a steam ejector cooler having a structure in which stress corrosion cracking does not occur.

〔考案の要旨〕[Summary of the idea]

上記の目的は、本考案によれば蒸気エゼクタ冷
却器下方のエゼクタ排気の流入口と反対側の胴壁
に沿いかつその内側に配設されているバツフル
と、前記胴壁との間を多数の小孔を備えた底板で
閉塞して、ｕ字状断面の冷却水室を形成し、該冷
却水室に冷却水を供給するように構成することに
よつて達成される。 According to the present invention, a large number of baffles are provided between the body wall and the buttful, which is disposed along and inside the body wall on the side opposite to the ejector exhaust inlet below the steam ejector cooler. This is accomplished by closing a bottom plate with small holes to form a cooling water chamber with a U-shaped cross section, and supplying cooling water to the cooling water chamber.

〔考案の実施例〕[Example of idea]

以下本考案を適用した実施例の図面に基づいて
説明する。第１図は本考案に係る応力腐蝕割れ防
止構造を備えた実施例の蒸気エゼクタ冷却器の断
面図で、第２図及び第３図は本考案の他の実施例
の部分断面図及び断面図である。なお第１図ない
し第３図において第４図と同一部分については同
符号を付すとともに、その構成、作用等について
重複する部分の説明を省略させていただくことと
する。 Embodiments to which the present invention is applied will be described below based on the drawings. FIG. 1 is a sectional view of an embodiment of a steam ejector cooler equipped with a stress corrosion cracking prevention structure according to the present invention, and FIGS. 2 and 3 are partial sectional views and sectional views of other embodiments of the present invention. It is. Note that in FIGS. 1 to 3, the same parts as in FIG. 4 are designated by the same reference numerals, and explanations of the overlapping parts in terms of structure, operation, etc. will be omitted.

第１図において、蒸気エゼクタ冷却器２の胴壁
４の下側方に配されている排気入口７の配設位置
の反対側の胴壁内周面にそいかつその前方にあ
り、その部分の胴壁内円周長の略1/2を長さとし、
ホツトウエル１３の最高水面から最下段の散水ト
レイ３ｎが配されている高さまでの間を高さとし
て、エゼクタ排気流を真正面に受ける胴壁４の領
域をカバーするように、胴壁内周面とある間隔を
保ちつつ胴壁４の内周面を覆つて配設されている
バツフル１４の下端と、胴壁４とバツフル１４と
の前記間隔寸法を巾とするリング状板をその直径
で1/2した形状の板であつて、その面に多数の小
孔が穿設されている底板１５の内周側端面とを、
さらにその外周側端面と胴壁４の内周面とをそれ
ぞれ結合させ、胴壁４とバツフル１４との間を閉
塞するとともに、バツフル１４の長さ方向の両端
面とそれに対する胴壁４の内周面との間を、底板
１５の巾とバツフル１４の高さを持つ２枚の側板
（図示せず）によつて閉塞することによつて、蒸
気エゼクタ冷却器２の内部下方にｕ字状断面でか
つ1/2リング状に続く冷却水室３０が画成される。
さらに最上段の散水トレイ３ａに連通するように
その一端を接続し他端の開口端を前記空間部の開
口面にのぞむよう、胴壁４の内周面に沿いかつそ
の縦方向に延伸させてある冷却水管１６が、冷却
水室３０の容積に応じて幾本か設けられている。 In FIG. 1, it is located along and in front of the inner circumferential surface of the body wall opposite to the location where the exhaust inlet 7 is disposed on the lower side of the body wall 4 of the steam ejector cooler 2. The length is approximately 1/2 of the circumference inside the trunk wall,
The height is defined as the height between the highest water level of the hot well 13 and the height at which the lowest watering tray 3n is arranged, and the inner circumferential surface of the body wall is designed to cover the area of the body wall 4 that directly receives the ejector exhaust flow. The lower end of the buttful 14, which is disposed to cover the inner circumferential surface of the body wall 4 while maintaining a certain distance, and the ring-shaped plate whose width is the width of the gap between the body wall 4 and the buttfull 14 are 1/1/1 in diameter. The inner peripheral side end surface of the bottom plate 15, which is a plate with a shape of 2 and has a large number of small holes bored on its surface,
Further, the outer circumferential side end surface and the inner circumferential surface of the body wall 4 are respectively connected to close the space between the body wall 4 and the buttful 14, and both end surfaces in the length direction of the buttful 14 and the inner circumferential surface of the body wall 4 are connected to each other. By closing the gap with the circumferential surface with two side plates (not shown) having the width of the bottom plate 15 and the height of the buttful 14, a U-shaped structure is formed in the lower part of the interior of the steam ejector cooler 2. A cooling water chamber 30 is defined that has a cross section and continues in a 1/2 ring shape.
Further, one end thereof is connected so as to communicate with the uppermost watering tray 3a, and the other end is extended along the inner circumferential surface of the body wall 4 in the longitudinal direction so as to look into the opening surface of the space. A number of cooling water pipes 16 are provided depending on the volume of the cooling water chamber 30.

以上説明したように蒸気エゼクタ冷却器２の内
部に配設されてるバツフル１４を利用し、冷却水
を貯留しかつ流下させる冷却水室３０を形成する
ことにより、最上段の散水トレイ３ａに供給され
る冷却水はエゼクタ排気の冷却に流下するととも
に、一部が冷却水管１６を介し冷却水室３０へ注
入貯留され、その一部が底板１５の小孔からホツ
トウエル１３へ流下し、余部がバツフル１４の上
縁を溢流し壁面を滑りおりてホツトウエル１３へ
流れ落ちるようになる。したがつて冷却水室３０
内へは絶えず新しい冷たい冷却水が供給され、か
つ流出するようになるため、バツフル１４及びそ
れに対向している胴壁部分のエゼクタ排気による
温度上昇を押え50℃以下に維持することができる
のである。 As explained above, by using the buffer 14 disposed inside the steam ejector cooler 2 to form the cooling water chamber 30 in which cooling water is stored and allowed to flow down, the water is supplied to the uppermost water sprinkling tray 3a. The cooling water flows down to cool the ejector exhaust gas, and part of it is injected into the cooling water chamber 30 through the cooling water pipe 16 and stored therein, part of it flows down from the small hole in the bottom plate 15 to the hot well 13, and the rest flows into the hot well 14. It overflows the upper edge of the wall, slides down the wall, and flows down into the hot well 13. Therefore, the cooling water chamber 30
Since new cold cooling water is constantly supplied into the tank and flows out, it is possible to suppress the temperature rise caused by the ejector exhaust on the buttful 14 and the body wall facing it, and to maintain the temperature below 50°C. .

応力腐蝕割れは、腐蝕によつて生じたきわめて
小さな腐蝕孔に引張り応力が集中するため、腐蝕
がすすまないのにかかわらず局部的に亀裂を生じ
遂には破断する現象であつて、構造物の残留応力
や環境中の応力腐蝕媒体の存在、使用材料の応力
腐蝕割れに対する感受性ならびに環境温度等が因
子として作用し発生するもので、特に環境温度が
50℃以下で起ることが稀であるがそれ以上の温度
では発生の危険性が非常に高いと言われている。
本考案はこの点に着目したもので、従来構造の蒸
気エゼクタ冷却器の下部特に排気入口７に直面し
ている胴壁部分は、既述したようにエゼクタ排気
によつて60℃〜100℃に加熱されるので、該排気
中に含まれる硫化水素のような応力腐蝕媒体の存
在とともに、応力腐蝕割れを発生し易い状態にお
かれているので、冷却水室３０を設け新しい冷却
水を常時注入し該室外へ溢流々下させることによ
り、応力腐蝕割れを発生しやすい部分に応力腐蝕
媒が直接々触することをなくするとともにバツフ
ル１４及び胴壁部分の温度を50℃以下に保持する
ことにより応力腐蝕割れの発生を略完全に防止す
ることができるようにした。 Stress corrosion cracking is a phenomenon in which tensile stress concentrates in extremely small corrosion holes caused by corrosion, resulting in localized cracking and eventual rupture even though corrosion is not progressing. It is caused by factors such as stress, the presence of a stress corrosion medium in the environment, the susceptibility of the materials used to stress corrosion cracking, and the environmental temperature.
Although it rarely occurs at temperatures below 50°C, it is said that the risk of occurrence is extremely high at temperatures above that.
The present invention focuses on this point, and as mentioned above, the lower part of the steam ejector cooler of the conventional structure, especially the part of the body wall facing the exhaust inlet 7, is heated to 60°C to 100°C by the ejector exhaust. Since the exhaust gas is heated, it is in a state where stress corrosion cracking is likely to occur due to the presence of stress corrosion media such as hydrogen sulfide contained in the exhaust gas, so a cooling water chamber 30 is provided and new cooling water is constantly injected. By overflowing to the outside of the room, the stress corrosion medium is prevented from coming into direct contact with areas where stress corrosion cracking is likely to occur, and the temperature of the buttful 14 and the shell wall portion is maintained at 50°C or less. The occurrence of stress corrosion cracking can be almost completely prevented.

第２図は本考案の他の実施例を示すもので、冷
却水室３０への冷却水の供給を冷却水管１６に代
え、冷却水管１０から冷却水管１８を分岐させ冷
却水室３０の胴壁４側に設けた冷却水入口１７へ
接続し、給水ポンプ１１の働きで図示しない冷却
水源から直接冷却水室３０へ冷却水を送流するよ
うに構成してある点が第１図の実施例と異るだけ
で、作用及び効果は第１図の場合と全く同様であ
る。 FIG. 2 shows another embodiment of the present invention, in which the supply of cooling water to the cooling water chamber 30 is replaced by the cooling water pipe 16, and the cooling water pipe 18 is branched from the cooling water pipe 10 to form the body wall of the cooling water chamber 30. The embodiment shown in FIG. 1 is configured so that the cooling water is connected to the cooling water inlet 17 provided on the 4 side, and the cooling water is sent directly from the cooling water source (not shown) to the cooling water chamber 30 by the action of the water supply pump 11. The operation and effect are exactly the same as in the case of FIG. 1, except for the difference.

また第３図も他の実施例を示したもので、バツ
フル１４を上方へ最上段の散水トレイ３ａの底板
まで延伸しその端部を接合固定するとともに、そ
の延伸部分の中間に溢流口２０を設けるようにし
て、冷却水室３０を上方へ大きく作り、冷却水の
貯留を多くするように構成したもので、胴壁４の
冷却面積を第１図の実施例に比し拡大させた点が
異るだけで、作用ならびに効果は全く既述のもの
と変わるところはない。 FIG. 3 also shows another embodiment, in which the buttful 14 is extended upward to the bottom plate of the uppermost watering tray 3a, its ends are joined and fixed, and an overflow port 20 is provided in the middle of the extended portion. The cooling water chamber 30 is made larger upwards so that more cooling water can be stored, and the cooling area of the body wall 4 is expanded compared to the embodiment shown in FIG. The only difference is that the action and effect are the same as those already described.

〔考案の効果〕[Effect of idea]

以上の説明から明らかなように、蒸気エゼクタ
冷却器の内部に図示しない冷却水源からの冷却水
が直接供給される冷却水室を画成し、冷却水を溢
流々下することにより胴壁部分及びバツフルに応
力腐蝕媒体の接触を防止するとともに、その温度
を常時50℃以下に維持するようにして、蒸気エゼ
クタ冷却器における応力腐蝕割れ発生の危険度を
略完全に防止し、その製品寿命を大巾に延長させ
ることができる大きな経済的効果が得られた。 As is clear from the above description, a cooling water chamber is defined inside the steam ejector cooler to which cooling water is directly supplied from a cooling water source (not shown), and by overflowing cooling water, the body wall portion and By thoroughly preventing contact with stress-corrosion media and maintaining the temperature below 50℃, the risk of stress corrosion cracking in the steam ejector cooler is almost completely prevented, and the product life is greatly extended. A great economical effect was obtained that could be extended in width.

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

第１図は本考案を適用した実施例による応力腐
蝕割れ防止構造を備えた蒸気エゼクタ冷却器の断
面図、第２図及び第３図は本考案を適用した異な
る実施例による応力腐蝕防止構造を備えた蒸気エ
ゼクタ冷却器の部分断面図と断面図、第４図は従
来例の蒸気エゼクタ冷却器の断面図である。 １……蒸気エゼクタ、２……蒸気エゼクタ冷却
器、３ａ，３ｂ……３ｎ……散水トレイ、４……
胴壁、５……排気流路、１０……冷却水管、１１
……給水ポンプ、１４……バツフル、１５……底
板、１６，１８……冷却水管、１９……バツフル
延長板、２０……溢流口、３０……冷却水室。 FIG. 1 is a sectional view of a steam ejector cooler equipped with a stress corrosion cracking prevention structure according to an embodiment of the present invention, and FIGS. 2 and 3 show stress corrosion prevention structures according to different embodiments of the present invention. FIG. 4 is a sectional view of a conventional steam ejector cooler. 1...Steam ejector, 2...Steam ejector cooler, 3a, 3b...3n...Water tray, 4...
Trunk wall, 5...Exhaust flow path, 10...Cooling water pipe, 11
...Water supply pump, 14...Bassful, 15...Bottom plate, 16, 18...Cooling water pipe, 19...Bassful extension plate, 20...Overflow port, 30...Cooling water chamber.

Claims (1)

【実用新案登録請求の範囲】[Scope of utility model registration request] 蒸気タービンの復水器に併置されタービン排気
中の不凝縮性ガスを吸引排出する蒸気エゼクタの
排気を、冷却器の下方から導入し該冷却器内部に
上下互い違いに交差させ配設してある複数段の散
水トレイの間を蛇行して上昇させる間に、該冷却
器の上方より供給され前記散水トレイを順次介し
流下する冷却水に接触させ復水としてその底部に
貯溜させるとともに、前記冷却器の上方から前記
不凝縮性ガスを放出する蒸気エゼクタ冷却器にお
いて、前記冷却器下方の前記排気の流入口と反対
側の胴壁に沿いその内側に配設されているバツフ
ルと、前記胴壁との間を多数の小孔を備えた底板
で閉塞してｕ字状断面の冷却水室を形成し、該冷
却水室に冷却水を供給するように構成したことを
特徴とする蒸気エゼクタ冷却器の応力腐蝕割れ防
止構造。 A plurality of steam ejectors are arranged in parallel with the condenser of the steam turbine and suck and discharge non-condensable gas in the turbine exhaust gas, and the exhaust gas is introduced from below the cooler and arranged vertically and intersectingly inside the cooler. While ascending in a meandering manner between the tiered watering trays, the water is brought into contact with the cooling water supplied from above the cooler and flowing down through the watering trays in sequence, and is stored as condensate at the bottom of the cooler. In a steam ejector cooler that discharges the non-condensable gas from above, a buttful disposed along and inside the body wall on the side opposite to the exhaust inlet below the cooler and the body wall is connected. A steam ejector cooler characterized in that a cooling water chamber having a U-shaped cross section is formed by closing the space between the holes with a bottom plate having a large number of small holes, and cooling water is supplied to the cooling water chamber. Structure that prevents stress corrosion and cracking.