JP6861944B2

JP6861944B2 - How to adjust the atmosphere inside the exhaust heat recovery boiler and the exhaust heat recovery boiler

Info

Publication number: JP6861944B2
Application number: JP2017009244A
Authority: JP
Inventors: 仁石原; 薫小澤; 敏史平崎; 泰彦尾山; 純也飯田
Original assignee: Tokyo Electric Power Co Inc; Tokyo Electric Power Co Holdings Inc
Current assignee: Tokyo Electric Power Co Holdings Inc
Priority date: 2017-01-23
Filing date: 2017-01-23
Publication date: 2021-04-21
Anticipated expiration: 2037-01-23
Also published as: JP2018119694A

Description

本発明は、コンバインドサイクル発電プラントの排熱回収ボイラおよび排熱回収ボイラ内部の雰囲気調整方法に関する。 The present invention relates to an exhaust heat recovery boiler of a combined cycle power plant and a method of adjusting the atmosphere inside the exhaust heat recovery boiler.

コンバインドサイクル発電プラントは、燃焼ガスによって駆動されるガスタービンの排ガスを排熱回収ボイラに導き、排ガスの余熱を利用して蒸気を生成し、得られた蒸気を蒸気タービンに導いて発電機を駆動し、発電する発電プラントである。これにより高効率の発電プラントを実現している。 The combined cycle power plant guides the exhaust gas of the gas turbine driven by the combustion gas to the exhaust heat recovery boiler, generates steam using the residual heat of the exhaust gas, and guides the obtained steam to the steam turbine to drive the generator. It is a power plant that generates electricity. This has realized a highly efficient power plant.

しかしながら、上記のような排熱回収ボイラは、特にその停止時において、外部環境（降雨等）の湿度の影響により、内部器材（特に、熱交換部のチューブ等）に腐食が発生し易いという問題がある。 However, the exhaust heat recovery boiler as described above has a problem that the internal equipment (particularly the tube of the heat exchange part) is easily corroded due to the influence of the humidity of the external environment (precipitation, etc.), especially when the boiler is stopped. There is.

特に、腐食を受けた器材は耐久性が低下するため、腐食がひどい場合には新しい器材への交換が必要となり、工事費用などがかかる。また、器材が腐食して発生した錆は、排熱回収ボイラの起動時に、ガスタービンから送り込まれる排ガスの気流によって剥がれ、排気部を通って排熱回収ボイラの外へと排出されることがあり、周囲を汚染する等の問題がある。そのため、器材に腐食が発生しないように、排熱回収ボイラに設置前の器材に対しては、防錆対策として塗装や溶射を行うことは可能であるが、器材の設置後はこれらの対策は実質的に不可能である。したがって、設置後に発生した錆については、排熱回収ボイラを起動させる前に、錆の除去を行うメンテナンス（例えば気吹掃除等）を行ってきた。しかしながら、排熱回収ボイラの内部、特に熱交換部は、チューブ等の器材が密集し、入り組んでいるため、上記のような器材の交換やメンテナンスの作業が困難で、作業者の負担が大きい。 In particular, since the durability of corroded equipment decreases, if the corrosion is severe, it is necessary to replace it with new equipment, which requires construction costs. In addition, rust generated by corrosion of equipment may be peeled off by the airflow of exhaust gas sent from the gas turbine when the exhaust heat recovery boiler is started, and may be discharged to the outside of the exhaust heat recovery boiler through the exhaust section. , There are problems such as polluting the surroundings. Therefore, in order to prevent corrosion of the equipment, it is possible to paint or spray the equipment before installation in the exhaust heat recovery boiler as a rust preventive measure, but after installing the equipment, these measures are taken. It is virtually impossible. Therefore, for the rust generated after installation, maintenance (for example, air blow cleaning) for removing the rust has been performed before starting the exhaust heat recovery boiler. However, since the equipment such as tubes is densely packed and complicated inside the exhaust heat recovery boiler, particularly the heat exchange part, it is difficult to replace and maintain the equipment as described above, and the burden on the operator is heavy.

そのため、これらの問題を解決するべく、特許文献１では、排熱回収ボイラの内部の全領域を加熱して錆を発生させないようにする手法が提案されている。しかしながら、このような手法では、排熱回収ボイラの内部の全領域を加熱するための加熱管が必要となるため多大な設備コストを要し、実用性の観点で好ましくない。また特許文献２では、比較的コストがかからない方法として、発生した錆を排熱回収ボイラの外部に放出させないようにする手法が提案されているが、この手法では、そもそも錆の発生自体を抑制することはできないため、根本的な解決には至らない。 Therefore, in order to solve these problems, Patent Document 1 proposes a method of heating the entire area inside the exhaust heat recovery boiler so as not to generate rust. However, such a method requires a heating tube for heating the entire area inside the exhaust heat recovery boiler, which requires a large equipment cost and is not preferable from the viewpoint of practicality. Further, Patent Document 2 proposes a method of preventing the generated rust from being released to the outside of the exhaust heat recovery boiler as a relatively inexpensive method, but this method suppresses the generation of rust itself in the first place. It cannot be done, so it does not lead to a fundamental solution.

特開２００２−０９８３０１号公報Japanese Unexamined Patent Publication No. 2002-098301 特開２００５−２４１０７５号公報Japanese Unexamined Patent Publication No. 2005-241075

そこで、本発明は、上記課題に鑑みてなされたものであり、排熱回収ボイラにおいて、内部器材に発生する腐食を防止し得る、排熱回収ボイラおよび排熱回収ボイラ内部の雰囲気調整方法を提供することを目的とする。 Therefore, the present invention has been made in view of the above problems, and provides a method for adjusting the atmosphere inside the exhaust heat recovery boiler and the exhaust heat recovery boiler, which can prevent corrosion generated in the internal equipment in the exhaust heat recovery boiler. The purpose is to do.

上記課題を解決するため、本発明は、燃焼ガスによって駆動されるガスタービンから排出される排ガスを導入して蒸気を発生させる熱交換部を備える排熱回収ボイラであって、前記排ガスが通過する前記熱交換部の排ガス流路に連通する空調設備をさらに備え、前記空調設備が、前記排ガス流路の気体を回収して冷却する冷却部と、前記冷却部で冷却した気体を加熱して前記排ガス流路に戻す加熱部と、を有することを特徴とする。 In order to solve the above problems, the present invention is an exhaust heat recovery boiler including a heat exchange unit that introduces exhaust gas discharged from a gas turbine driven by combustion gas to generate steam, through which the exhaust gas passes. An air conditioning facility that communicates with the exhaust gas flow path of the heat exchange section is further provided, and the air conditioning facility heats a cooling section that collects and cools the gas in the exhaust gas flow path and the gas cooled by the cooling section. It is characterized by having a heating unit for returning to the exhaust gas flow path.

また、前記空調設備は、前記冷却部で冷却した気体を、前記加熱部で加熱する前に、除湿する除湿部をさらに有することが好ましい。 Further, it is preferable that the air-conditioning equipment further has a dehumidifying section for dehumidifying the gas cooled by the cooling section before the heating section heats the gas.

また、前記冷却部は、前記排ガス流路から気体を回収するための吸気路を有し、前記加熱部は、加熱した気体を前記排ガス流路に戻すための戻し路を有し、前記吸気路と前記戻し路とは、地面に対して水平方向に見たときに、前記熱交換部を挟む位置関係で配置されていることが好ましい。 Further, the cooling unit has an intake passage for recovering gas from the exhaust gas flow path, and the heating unit has a return path for returning the heated gas to the exhaust gas flow path, and the intake passage. And the return path are preferably arranged so as to sandwich the heat exchange portion when viewed in the horizontal direction with respect to the ground.

また、前記冷却部は、前記排ガス流路から気体を回収するための吸気路を有し、前記加熱部は、加熱した気体を前記排ガス流路に戻すための戻し路を有し、前記吸気路の先端は、地面に対して垂直方向に見たときに、前記戻し路の先端よりも低い位置で、前記排ガス流路に接続されていることが好ましい。 Further, the cooling unit has an intake passage for recovering gas from the exhaust gas flow path, and the heating unit has a return path for returning the heated gas to the exhaust gas flow path, and the intake passage. It is preferable that the tip of the exhaust gas is connected to the exhaust gas flow path at a position lower than the tip of the return path when viewed in a direction perpendicular to the ground.

また、本発明は、燃焼ガスによって駆動されるガスタービンから排出される排ガスを導入して蒸気を発生させる熱交換部を備える排熱回収ボイラの内部雰囲気調整方法であって、前記熱交換部の周囲を略密閉状態にする、準備工程と、前記排ガスが通過する前記熱交換部の排ガス流路の気体を回収して冷却する、冷却工程と、前記冷却工程にて冷却した気体を加熱して前記排ガス流路に戻す、加熱工程と、を有することを特徴とする。 Further, the present invention is a method for adjusting the internal atmosphere of an exhaust heat recovery boiler including a heat exchange unit that introduces exhaust gas discharged from a gas turbine driven by combustion gas to generate steam. The preparatory step of making the surroundings substantially sealed, the cooling step of recovering and cooling the gas in the exhaust gas flow path of the heat exchange section through which the exhaust gas passes, and the cooling step of heating the gas cooled in the cooling step. It is characterized by having a heating step of returning to the exhaust gas flow path.

本発明によれば、排熱回収ボイラにおいて、内部器材に発生する腐食を効果的に抑制することができる。 According to the present invention, in the exhaust heat recovery boiler, corrosion generated in the internal equipment can be effectively suppressed.

本発明の実施の形態に係る排熱回収ボイラの概略構成図である。It is a schematic block diagram of the exhaust heat recovery boiler which concerns on embodiment of this invention. 本発明の実施の形態に係る排熱回収ボイラの熱交換部および空調設備の付近を拡大した概略構成図である。It is a schematic block diagram which enlarged the vicinity of the heat exchange part and the air-conditioning equipment of the exhaust heat recovery boiler which concerns on embodiment of this invention.

本発明の好ましい実施の形態について、図面を参照しながら説明する。なお、以下に示す実施の形態は一つの例示であり、本発明の範囲において、種々の実施の形態をとり得る。 A preferred embodiment of the present invention will be described with reference to the drawings. The embodiments shown below are examples, and various embodiments can be taken within the scope of the present invention.

図１は、排熱回収ボイラの一例を示す構成概略図である。図２は、図１において、排熱回収ボイラの熱交換部および空調設備の付近を拡大した概略構成図である。 FIG. 1 is a schematic configuration diagram showing an example of an exhaust heat recovery boiler. FIG. 2 is an enlarged schematic configuration diagram of the vicinity of the heat exchange portion and the air conditioning equipment of the exhaust heat recovery boiler in FIG.

排熱回収ボイラ１は、例えば、コンバインドサイクル発電プラントに設けられている。コンバインドサイクル発電プラントは、燃焼ガスによって駆動されるガスタービンの排ガスを排熱回収ボイラ１に導き、排ガスの余熱を利用して蒸気を生成し、得られた蒸気を蒸気タービンに導いて発電機を駆動し、発電する発電プラントである。
図１および図２に示すように、排熱回収ボイラ１は、熱交換部１１と、空調設備１３と、排気部１５と、脱硝触媒装置１７等を備えている。
排熱回収ボイラ１の運転時には、燃焼ガスによって駆動されるガスタービン２から排出された排ガスが熱交換部１１に送り込まれ、熱交換部１１にて排ガスの余熱を利用して蒸気を生成し、さらに熱交換部１１を通過した排ガスは排気部１５から外部に排出される。なお、図１中の矢印は、排熱回収ボイラ１の運転時における排ガスの流れ方向を示している。 The exhaust heat recovery boiler 1 is provided in, for example, a combined cycle power generation plant. The combined cycle power plant guides the exhaust gas of the gas turbine driven by the combustion gas to the exhaust heat recovery boiler 1, generates steam using the residual heat of the exhaust gas, and guides the obtained steam to the steam turbine to generate a generator. It is a power plant that drives and generates electricity.
As shown in FIGS. 1 and 2, the exhaust heat recovery boiler 1 includes a heat exchange unit 11, an air conditioning equipment 13, an exhaust unit 15, a denitration catalyst device 17, and the like.
During the operation of the exhaust heat recovery boiler 1, the exhaust gas discharged from the gas turbine 2 driven by the combustion gas is sent to the heat exchange unit 11, and the heat exchange unit 11 uses the residual heat of the exhaust gas to generate steam. Further, the exhaust gas that has passed through the heat exchange unit 11 is discharged to the outside from the exhaust unit 15. The arrows in FIG. 1 indicate the flow direction of the exhaust gas during the operation of the exhaust heat recovery boiler 1.

（熱交換部）
熱交換部１１は、ガスタービン２から排出される排ガスを導入して、排ガスの熱を利用して蒸気を発生させる。具体的に、熱交換部１１は、水や水蒸気を導通させる熱交換パネル１１１を備えており、これらの熱交換パネル１１１は、排ガスの流路Ｆ上で、当該排ガスの流れに対向するように配置されている。熱交換部１１に導かれた排ガスは、その余熱により熱交換パネル１１１を加熱することで、熱交換パネル１１１内の水を加熱し、水蒸気を発生させる。 (Heat exchange part)
The heat exchange unit 11 introduces the exhaust gas discharged from the gas turbine 2 and uses the heat of the exhaust gas to generate steam. Specifically, the heat exchange unit 11 includes heat exchange panels 111 for conducting water and water vapor, and these heat exchange panels 111 face the flow of the exhaust gas on the flow path F of the exhaust gas. Have been placed. The exhaust gas guided to the heat exchange unit 11 heats the heat exchange panel 111 with the residual heat, thereby heating the water in the heat exchange panel 111 and generating water vapor.

熱交換パネル１１１は、複数のチューブが一連に連なったチューブ群により構成され、熱交換パネル１１１は、図示しない蒸気タービンに連結されており、熱交換パネル１１１内で発生した水蒸気を蒸気タービンへと導いている。また熱交換パネル１１１を構成するチューブとしては、例えば、ボイラ・熱交換器用合金鋼管（ＳＴＢＡ）等が好適に用いられる。 The heat exchange panel 111 is composed of a group of tubes in which a plurality of tubes are connected in a series, and the heat exchange panel 111 is connected to a steam turbine (not shown), and the water vapor generated in the heat exchange panel 111 is transferred to the steam turbine. I'm leading. Further, as the tube constituting the heat exchange panel 111, for example, an alloy steel pipe for a boiler / heat exchanger (STBA) or the like is preferably used.

熱交換部１１は、複数の熱交換パネル１１１を有していてもよい。このような熱交換部１１において、排ガスは、熱交換パネル１１１の間、さらには熱交換パネル１１１を構成するチューブ同士の隙間を、下流の排気部１５に向かって流れる。したがって、熱交換部１１の排ガス流路Ｆは、熱交換パネル１１１同士の間や、図示は省略しているが熱交換パネル１１１のチューブ同士の隙間にも存在する。 The heat exchange unit 11 may have a plurality of heat exchange panels 111. In such a heat exchange unit 11, the exhaust gas flows between the heat exchange panels 111 and further through the gaps between the tubes constituting the heat exchange panel 111 toward the downstream exhaust unit 15. Therefore, the exhaust gas flow path F of the heat exchange unit 11 also exists between the heat exchange panels 111 and also in the gap between the tubes of the heat exchange panel 111, although not shown.

（空調設備）
図１および図２に示すように、空調設備１３は、排熱回収ボイラ１の停止時に、熱交換部１１の内部、特に熱交換部１１における排ガス流路Ｆの雰囲気（温度、湿度）を調整するものである。空調設備１３は、冷却部１３３、加熱部１３５、除湿部１３９等を備えている。 (Air conditioning equipment)
As shown in FIGS. 1 and 2, the air conditioning equipment 13 adjusts the atmosphere (temperature, humidity) of the exhaust gas flow path F inside the heat exchange unit 11, particularly in the heat exchange unit 11, when the exhaust heat recovery boiler 1 is stopped. To do. The air conditioning equipment 13 includes a cooling unit 133, a heating unit 135, a dehumidifying unit 139, and the like.

空調設備１３は、運転停止している熱交換部１１の排ガス流路Ｆから気体ｇ１を回収して、冷却部１３３において冷却し、冷却した気体ｇ２を加熱部１３５で加熱して、加熱した気体ｇ３として熱交換部１１の排ガス流路Ｆに送り戻す空調システムである。 The air conditioning equipment 13 recovers the gas g1 from the exhaust gas flow path F of the heat exchange unit 11 that has stopped operating, cools the gas g1 in the cooling unit 133, heats the cooled gas g2 in the heating unit 135, and heats the gas. This is an air conditioning system that sends back to the exhaust gas flow path F of the heat exchange unit 11 as g3.

冷却部１３３は、熱交換部１１の排ガス流路Ｆから気体ｇ１を回収して、回収した気体ｇ１を冷却する部分である。冷却は、公知の冷却用の空調装置により行うことができる。また冷却時の温度設定は、冷却後の気体ｇ２の温度Ｔ２が、排ガス流路Ｆに存在する気体ｇ１の温度Ｔ１よりも低くなるように設定する。このような温度設定で気体ｇ１を冷却することで、気体ｇ１に含まれる水蒸気量Ｐと、冷却後の気体温度Ｔ２の飽和水蒸気量Ｐ２の差分に応じて、気体ｇ１に含まれていた水蒸気の一部が凝集して、水分として気体から分離される。そのため、冷却部１３３は、気体ｇ１を冷却することにより生じた水分を冷却部１３３の外に排出するための排水路１３４を有する。 The cooling unit 133 is a portion that recovers the gas g1 from the exhaust gas flow path F of the heat exchange unit 11 and cools the recovered gas g1. Cooling can be performed by a known cooling air conditioner. Further, the temperature at the time of cooling is set so that the temperature T2 of the gas g2 after cooling is lower than the temperature T1 of the gas g1 existing in the exhaust gas flow path F. By cooling the gas g1 with such a temperature setting, the amount of water vapor contained in the gas g1 is increased according to the difference between the amount of water vapor P contained in the gas g1 and the saturated water vapor amount P2 of the gas temperature T2 after cooling. Part of it aggregates and separates from the gas as water. Therefore, the cooling unit 133 has a drainage channel 134 for discharging the water generated by cooling the gas g1 to the outside of the cooling unit 133.

また、冷却部１３３は、排ガス流路Ｆから気体ｇ１を回収するための吸気路１３１を有する。吸気路１３１は、地面に対して水平方向で見たときに、後述する加熱部１３５の戻し路１３７とは反対側の、熱交換部１１の端に配置される。さらに、吸気路１３１の先端（吸気口）１３１ａは、地面に対して垂直方向で見たときに、後述する加熱部１３５の戻し路１３７の先端（戻し口）１３７ａよりも低い位置で、排ガス経路に接続される。 Further, the cooling unit 133 has an intake passage 131 for recovering the gas g1 from the exhaust gas flow path F. The intake passage 131 is arranged at the end of the heat exchange portion 11 on the opposite side of the return passage 137 of the heating portion 135, which will be described later, when viewed in the horizontal direction with respect to the ground. Further, the tip (intake port) 131a of the intake path 131 is located at a position lower than the tip (return port) 137a of the return path 137 of the heating unit 135, which will be described later, when viewed in the direction perpendicular to the ground. Connected to.

加熱部１３５は、冷却部１３３で冷却された気体ｇ２を加熱して、排ガス流路Ｆに戻す部分である。加熱は、公知の加熱用の空調装置により行うことができる。また加熱時の温度設定は、加熱後の気体ｇ３の温度Ｔ３が、冷却後の気体ｇ２の温度Ｔ２以上、好ましくは排ガス流路Ｆに存在する気体ｇ１の温度Ｔ１以上になるように設定する。 The heating unit 135 is a portion that heats the gas g2 cooled by the cooling unit 133 and returns it to the exhaust gas flow path F. Heating can be performed by a known heating air conditioner. The temperature at the time of heating is set so that the temperature T3 of the gas g3 after heating is equal to or higher than the temperature T2 of the gas g2 after cooling, preferably the temperature T1 or higher of the gas g1 existing in the exhaust gas flow path F.

このような加熱部１３５は、加熱した気体ｇ３を排ガス流路Ｆに送り戻すための戻し路１３７を有する。戻し路１３７は、地面に対して水平方向で見たときに、冷却部１３５の吸気路１３１とは反対側の、熱交換部１１の端に配置される。さらに、戻し路１３７の先端（戻し口）１３７ａは、地面に対して垂直方向で見たときに、冷却部１３３の吸気路１３１の先端（吸気口）１３１ａよりも高い位置で、排ガス経路に接続される。より具体的には、吸気路１３１の先端（吸気口）１３１ａは、排ガス流路Ｆの底部近傍に設けられており、戻し路１３７の先端（戻し口）１３７ａは、排ガス流路Ｆの天井部近傍に設けられている。 Such a heating unit 135 has a return path 137 for sending the heated gas g3 back to the exhaust gas flow path F. The return path 137 is arranged at the end of the heat exchange section 11 on the opposite side of the cooling section 135 from the intake path 131 when viewed horizontally with respect to the ground. Further, the tip (return port) 137a of the return path 137 is connected to the exhaust gas path at a position higher than the tip (intake port) 131a of the intake path 131 of the cooling unit 133 when viewed in the direction perpendicular to the ground. Will be done. More specifically, the tip (intake port) 131a of the intake passage 131 is provided near the bottom of the exhaust gas flow path F, and the tip (return port) 137a of the return path 137 is the ceiling portion of the exhaust gas flow path F. It is provided in the vicinity.

除湿部１３９は、冷却部１３３と加熱部１３５の間の気体ｇ２の経路上に設けられている。除湿部１３９は、冷却部１３３で冷却された気体ｇ２を、物理的または化学的に除湿する部分である。このような除湿には、公知の吸湿式除湿装置を用いることができる。また、吸湿材としては活性炭、シリカ等を用いることができる。 The dehumidifying unit 139 is provided on the path of the gas g2 between the cooling unit 133 and the heating unit 135. The dehumidifying unit 139 is a portion that physically or chemically dehumidifies the gas g2 cooled by the cooling unit 133. A known wet-absorbing dehumidifying device can be used for such dehumidification. Further, activated carbon, silica and the like can be used as the moisture absorbing material.

（排気部）
図１に示すように、排気部１５は排ガス流路Ｆの下流に位置し、熱交換部１１を通過した排ガスを、排熱回収ボイラ１の外部に排出する部分である。 (Exhaust part)
As shown in FIG. 1, the exhaust unit 15 is located downstream of the exhaust gas flow path F, and is a portion that discharges the exhaust gas that has passed through the heat exchange unit 11 to the outside of the exhaust heat recovery boiler 1.

（脱硝触媒装置）
脱硝触媒装置１７は、ガスタービン２から導かれる排ガスから窒素酸化物（ＮＯｘ）を除去する装置である。 (Denitration catalyst device)
The denitration catalyst device 17 is a device that removes nitrogen oxides (NOx) from the exhaust gas led from the gas turbine 2.

＜排熱回収ボイラの内部雰囲気調整方法＞
以下、本実施の形態に係る排熱回収ボイラ内部の雰囲気調整方法について説明する。 <How to adjust the internal atmosphere of the exhaust heat recovery boiler>
Hereinafter, a method for adjusting the atmosphere inside the exhaust heat recovery boiler according to the present embodiment will be described.

図１に示すように、排熱回収ボイラ１の一端は、ガスタービン２に連結されており、また他端は、排気部１５から外部に通じている。そのため、まず、図２に示すように、熱交換部１１の周囲に仕切体１４を設け、熱交換部１１の周囲を略密閉状態にする（準備工程）。これにより、熱交換部１１の周囲の空気だけを効率よく雰囲気調整できる。ここで、仕切体１４は、熱交換部１１の周囲を覆うことができるものであればよく、例えば、防炎シート等を用いることができる。なお、ここでいう略密閉状態とは、厳密な密閉状態ではなく、空調設備１３による気体の移動以外の外部からの空気の出入りを遮断できる程度の封止状態を意味する。 As shown in FIG. 1, one end of the exhaust heat recovery boiler 1 is connected to the gas turbine 2, and the other end is connected to the outside from the exhaust unit 15. Therefore, first, as shown in FIG. 2, a partition body 14 is provided around the heat exchange unit 11 to make the periphery of the heat exchange unit 11 substantially sealed (preparation step). As a result, only the air around the heat exchange unit 11 can be efficiently adjusted in atmosphere. Here, the partition body 14 may be any as long as it can cover the periphery of the heat exchange unit 11, and for example, a flameproof sheet or the like can be used. The substantially sealed state referred to here does not mean a strict sealed state, but a sealed state that can block the inflow and outflow of air from the outside other than the movement of gas by the air conditioning equipment 13.

次に、熱交換部１１の排ガス流路Ｆから気体ｇ１を回収し、冷却部１３１にて冷却する（冷却工程）。さらに、冷却後の気体ｇ２に対し、除湿部１３９にて物理的または化学的な吸湿処理により、除湿してもよい（吸湿除湿工程）。 Next, the gas g1 is recovered from the exhaust gas flow path F of the heat exchange unit 11 and cooled by the cooling unit 131 (cooling step). Further, the cooled gas g2 may be dehumidified by a physical or chemical moisture absorption treatment in the dehumidification section 139 (moisture absorption / dehumidification step).

次に、加熱部１３５にて冷却後の気体ｇ２を加熱して、加熱後の気体ｇ３を熱交換部１１の排ガス流路Ｆに戻す（加熱工程）。 Next, the heated gas g2 is heated by the heating unit 135, and the heated gas g3 is returned to the exhaust gas flow path F of the heat exchange unit 11 (heating step).

さらに、上記冷却と加熱の各工程を繰り返すことで、上記各気体を循環させ、特に熱交換部１１の内部の雰囲気を、所望の温度および湿度に制御する。特に、熱交換部１１は、その周囲が略密閉状態となっているため、上記のような雰囲気制御により、外部環境（仕切体１４の外側の環境、ひいては排熱回収ボイラ１の外の環境）の湿度の影響を受けにくい。 Further, by repeating each of the steps of cooling and heating, each of the above gases is circulated, and in particular, the atmosphere inside the heat exchange unit 11 is controlled to a desired temperature and humidity. In particular, since the heat exchange unit 11 is in a substantially sealed state around it, the external environment (the environment outside the partition body 14, and by extension, the environment outside the exhaust heat recovery boiler 1) is controlled by the above atmosphere control. Not easily affected by humidity.

上述した構成によれば、排熱回収ボイラ１は、熱交換部１１の排ガス流路Ｆに連通する、冷却部１３３および加熱部１３５を有する空調設備１３を備えているので、排熱回収ボイラ１の停止時において、特に熱交換部１１の排ガス流路Ｆ内の湿度および温度を容易に制御できる。すなわち、冷却部１３３は、排ガス流路Ｆの気体ｇ１を、温度Ｔ１から温度Ｔ２に冷却することで、気体ｇ１に含まれる水蒸気量Ｐを、温度Ｔ２における飽和水蒸気量Ｐ２まで下げることができ、気体ｇ１の水蒸気量Ｐと温度Ｔ２における飽和水蒸気量Ｐ２との差分（Ｐ−Ｐ２）は、冷却過程で凝集し水滴として取り出すことできる。さらに、加熱部１３５は、冷却後の気体ｇ２を温度Ｔ３まで加熱することで、加熱後の気体ｇ３における相対湿度を低くでき、相対湿度が低い気体ｇ３として、排ガス流路Ｆに戻すことができる。このように、停止時の排熱回収ボイラ１において、熱交換部１１の排ガス流路Ｆ内を、相対湿度が低い雰囲気に調整することにより、内部器材（例えば、熱交換部１１のチューブ等）への結露を防止でき、内部器材の腐食を効果的に抑制できる。その結果、排熱回収ボイラ１の内部器材の寿命が延び、内部器材の交換やメンテナンスの回数を低減できる。また、内部器材が腐食して錆が発生することを防止できるため、排熱回収ボイラ１を運転させても、排気部１５を通じて錆が設備の外部に放出されることはなく、錆の飛散防止等の対策を講じる必要がない。 According to the above-described configuration, since the exhaust heat recovery boiler 1 includes an air conditioning facility 13 having a cooling unit 133 and a heating unit 135 communicating with the exhaust gas flow path F of the heat exchange unit 11, the exhaust heat recovery boiler 1 is provided. In particular, the humidity and temperature in the exhaust gas flow path F of the heat exchange unit 11 can be easily controlled when the heat exchange unit 11 is stopped. That is, the cooling unit 133 can reduce the amount of water vapor P contained in the gas g1 to the saturated water vapor amount P2 at the temperature T2 by cooling the gas g1 of the exhaust gas flow path F from the temperature T1 to the temperature T2. The difference (P-P2) between the amount of water vapor P of the gas g1 and the amount of saturated water vapor P2 at the temperature T2 can be aggregated in the cooling process and taken out as water droplets. Further, the heating unit 135 can reduce the relative humidity of the heated gas g3 by heating the cooled gas g2 to the temperature T3, and can return the gas g3 to the exhaust gas flow path F as a gas g3 having a low relative humidity. .. In this way, in the exhaust heat recovery boiler 1 when stopped, the inside of the exhaust gas flow path F of the heat exchange unit 11 is adjusted to an atmosphere in which the relative humidity is low, so that the internal equipment (for example, the tube of the heat exchange unit 11 or the like) is used. Condensation can be prevented and corrosion of internal equipment can be effectively suppressed. As a result, the life of the internal equipment of the exhaust heat recovery boiler 1 is extended, and the number of times of replacement and maintenance of the internal equipment can be reduced. Further, since it is possible to prevent the internal equipment from corroding and causing rust, even if the exhaust heat recovery boiler 1 is operated, the rust is not released to the outside of the equipment through the exhaust unit 15 and the rust is prevented from scattering. There is no need to take measures such as.

また、空調設備１３が、除湿部１３９を備えていることにより、冷却部１３３で冷却した気体ｇ２を、加熱部１３５で加熱する前に、物理的または化学的に吸湿して除湿することができ、気体ｇ２の湿度をさらに低下させることができる。その結果、排ガス流路Ｆに戻される加熱後の気体ｇ３の相対湿度をさらに低減でき、停止時の排熱回収ボイラ１において、熱交換部１１の排ガス流路Ｆ内をより乾燥した状態に調整できる。 Further, since the air conditioning equipment 13 includes the dehumidifying unit 139, the gas g2 cooled by the cooling unit 133 can be physically or chemically absorbed and dehumidified before being heated by the heating unit 135. , The humidity of the gas g2 can be further reduced. As a result, the relative humidity of the heated gas g3 returned to the exhaust gas flow path F can be further reduced, and the inside of the exhaust gas flow path F of the heat exchange unit 11 is adjusted to a drier state in the exhaust heat recovery boiler 1 when stopped. it can.

空調設備１３において、冷却部１３３の吸気路１３１と、加熱部１３５の戻し路１３７とは、地面に対して水平方向に見たときに、熱交換部１１を挟む位置関係で配置され、かつ、吸気路１３１の先端１３１ａは、地面に対して垂直方向に見たときに、戻し路１３７の先端１３７ａよりも低い位置で、排ガス流路Ｆに接続されることにより、相対湿度が低い気体ｇ３が、効率よく熱交換部１１の排ガス流路Ｆに行き渡り、熱交換部１１の全体を所望の雰囲気に制御しやすくなる。通常、温かい空気は上方に滞留しやすいが、吸気路１３１の先端１３１ａを、戻し路１３７の先端１３７ａとは対角線上にある、熱交換部１１の下方の隅に配置し、排ガス流路Ｆの下方側から気体を吸引することで、上方側に滞留し易い温かい気体を強制的に下方側に向かって流動させることができ、排ガス流路Ｆにおける気体の循環を良好にできる。これにより、相対湿度が低い気体ｇ３を効率よく熱交換部１１に行き渡らせることができる。このような空調設備１３における吸気路１３１と戻し路１３７の位置関係は、排ガス流路Ｆに戻される気体ｇ３の温度が、排ガス流路Ｆに存在する気体ｇ１の温度よりも高い場合に、特に好適である。 In the air conditioning equipment 13, the intake passage 131 of the cooling portion 133 and the return passage 137 of the heating portion 135 are arranged in a positional relationship sandwiching the heat exchange portion 11 when viewed in the horizontal direction with respect to the ground. The tip 131a of the intake path 131 is connected to the exhaust gas flow path F at a position lower than the tip 137a of the return path 137 when viewed in the direction perpendicular to the ground, so that the gas g3 having a low relative humidity can be generated. , Efficiently spreads over the exhaust gas flow path F of the heat exchange unit 11, and it becomes easy to control the entire heat exchange unit 11 to a desired atmosphere. Normally, warm air tends to stay upward, but the tip 131a of the intake passage 131 is arranged in the lower corner of the heat exchange portion 11 diagonally opposite to the tip 137a of the return path 137, and the exhaust gas flow path F By sucking the gas from the lower side, the warm gas that tends to stay in the upper side can be forcibly flowed toward the lower side, and the gas circulation in the exhaust gas flow path F can be improved. As a result, the gas g3 having a low relative humidity can be efficiently distributed to the heat exchange unit 11. The positional relationship between the intake passage 131 and the return passage 137 in the air conditioning equipment 13 is particularly large when the temperature of the gas g3 returned to the exhaust gas flow path F is higher than the temperature of the gas g1 existing in the exhaust gas flow path F. Suitable.

１排熱回収ボイラ
２ガスタービン
１１熱交換部
１３空調設備
１５排気部
１１１熱交換パネル
１３１吸気路
１３３冷却部
１３４排水路
１３５加熱部
１３７戻し路
１３９除湿部
Ｆ排ガス流路 1 Exhaust heat recovery boiler 2 Gas turbine 11 Heat exchange section 13 Air conditioning equipment 15 Exhaust section 111 Heat exchange panel 131 Intake path 133 Cooling section 134 Drainage channel 135 Heating section 137 Return path 139 Dehumidifying section F Exhaust gas flow path

Claims

An exhaust heat recovery boiler equipped with a heat exchange unit that introduces exhaust gas discharged from a gas turbine driven by combustion gas to generate steam.
A partition around the heat exchange section that blocks air from the outside to make it substantially sealed.
And the air conditioning equipment that communicates with the exhaust gas passage of the heat exchanging portion in which the exhaust gas passes through, further comprising a
The air conditioning equipment
A cooling unit that recovers and cools the gas in the exhaust gas flow path,
A heating unit that heats the gas cooled by the cooling unit and returns it to the exhaust gas flow path,
A waste heat recovery boiler characterized by having.

The exhaust heat recovery boiler according to claim 1, wherein the air conditioning equipment further includes a dehumidifying unit for dehumidifying the gas cooled by the cooling unit before being heated by the heating unit.

The cooling unit has an intake passage for recovering gas from the exhaust gas flow path.
The heating unit has a return path for returning the heated gas to the exhaust gas flow path.
The exhaust according to claim 1 or 2, wherein the intake passage and the return passage are arranged in a positional relationship sandwiching the heat exchange portion when viewed in a horizontal direction with respect to the ground. Heat recovery boiler.

The cooling unit has an intake passage for recovering gas from the exhaust gas flow path.
The heating unit has a return path for returning the heated gas to the exhaust gas flow path.
Claim 1 or 2, wherein the tip of the intake path is connected to the exhaust gas flow path at a position lower than the tip of the return path when viewed in a direction perpendicular to the ground. Exhaust heat recovery boiler described in.

It is a method of adjusting the internal atmosphere of an exhaust heat recovery boiler equipped with a heat exchange unit that introduces exhaust gas discharged from a gas turbine driven by combustion gas to generate steam.
A preparatory step in which a partition body is provided around the heat exchange portion to block air from the outside and make it a substantially sealed state.
A cooling process in which the gas in the exhaust gas flow path of the heat exchange section through which the exhaust gas passes is recovered and cooled.
A heating step of heating the gas cooled in the cooling step and returning it to the exhaust gas flow path.
A method for adjusting the internal atmosphere of an exhaust heat recovery boiler, which comprises the above.