JPH08200650A - Preventing device of backflow of high temperature gas - Google Patents

Preventing device of backflow of high temperature gas

Info

Publication number
JPH08200650A
JPH08200650A JP1223695A JP1223695A JPH08200650A JP H08200650 A JPH08200650 A JP H08200650A JP 1223695 A JP1223695 A JP 1223695A JP 1223695 A JP1223695 A JP 1223695A JP H08200650 A JPH08200650 A JP H08200650A
Authority
JP
Japan
Prior art keywords
gas
damper
high temperature
duct
exhaust gas
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP1223695A
Other languages
Japanese (ja)
Inventor
Nobuaki Shimizu
宣明 清水
Hiroshi Nagahisa
博司 永久
Shigenobu Oshima
重信 大嶋
Katsuhiko Igaue
克彦 伊賀上
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Power Ltd
Original Assignee
Babcock Hitachi KK
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Babcock Hitachi KK filed Critical Babcock Hitachi KK
Priority to JP1223695A priority Critical patent/JPH08200650A/en
Publication of JPH08200650A publication Critical patent/JPH08200650A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE: To avoid that a high temperature gas staying in a heat exchanger part is forced back to flow backward and thereby to prevent damages of a gas turbine and others from occurring by a construction wherein an exhaust means having a structure wherein the high temperature gas is exhausted outside a system by a funnel effect produced by a temperature difference from the atmosphere is provided in the ceiling part of a duct of a damper. CONSTITUTION: In an exhaust gas dust of a gas turbine 7 wherein a heat exchanger 6 heating exhaust gas and a damper 1 intercepting combustion exhaust gas at the time of stop of an operation are provided in an exhaust gas outlet duct 5 of a combustion apparatus such as the gas turbine 7, a high temperature gas remaining in the duct on the front flow side of the damper 1 and in the heat exchanger 6 is prevented from being forced back to a combustor by a gas flow leaking from the rear flow side of the damper 1 closed into the duct on the front flow side at the time of stop of the operation of the combustion apparatus. As a means for preventing this backflow, a preventing device of backflow of the high temperature gas which is installed in the duct 5 between a gas heater 6 and the damper 1 and constructed of gas vent valves 3 and 4 and a seal air valve 2 is provided.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は排気再燃コンバインドサ
イクルプラント等におけるガスタービン等の運転停止時
に、排ガス出口ダクト内の高温排ガスの逆流によるガス
タービン等の燃焼機器の損傷を防止するのに好適な構造
の高温ガス逆流防止装置に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable for preventing damage to combustion equipment such as a gas turbine due to backflow of high temperature exhaust gas in an exhaust gas outlet duct when the operation of a gas turbine or the like in an exhaust gas recombustion combined cycle plant or the like is stopped. The present invention relates to a hot gas backflow prevention device having a structure.

【0002】[0002]

【従来の技術】従来のガスタービンの排ガス出口ダクト
系の一例として、図3に示すように、ガスタービン7の
排ガス出口ダクト5には、排ガスを加熱するガスヒータ
(熱交換器)6が設けられており、その後流に、上記ガ
スタービンの運転停止時にボイラからの燃焼ガスを遮断
するためのダンパ1が設けられている。すなわち、ガス
タービン7の運転時には、ガスタービン7の排ガスは、
ダクト5に設置されているガスヒータ6とダンパ1を通
り、ボイラ(図示せず)へ供給されている。そして、ガ
スタービンの運転停止時にはダンパ1を遮断していた。
この従来のダクト系において、上記ダンパ1により排ガ
スを完全に遮断することができなくても、ダンパ1の後
流側は常時負圧であるため、ダンパ1の後流側から前流
側への排ガスが逆流する現象は生じなかった。しかし、
排気再燃コンバインドサイクルプラントにおいては、ダ
ンパ1の後流側が正圧となり、ダンパ1の後流側から前
流側へ排ガスがリークし、ダンパ1の前流側のダクト5
およびガスヒータ6内に滞留している高温ガスが押し戻
されガスタービン7等の燃焼機器が損傷されるという問
題があった。なお、従来技術として、例えば、特開昭6
2−41514号公報に記載されている排煙脱硫設備に
おける排ガスの通風制御方法等が挙げられる。
2. Description of the Related Art As an example of an exhaust gas outlet duct system of a conventional gas turbine, a gas heater (heat exchanger) 6 for heating exhaust gas is provided in an exhaust gas outlet duct 5 of a gas turbine 7 as shown in FIG. Further, a damper 1 for cutting off the combustion gas from the boiler when the operation of the gas turbine is stopped is provided in the subsequent flow. That is, when the gas turbine 7 is in operation, the exhaust gas of the gas turbine 7 is
It is supplied to a boiler (not shown) through a gas heater 6 installed in the duct 5 and the damper 1. The damper 1 was shut off when the gas turbine was stopped.
In this conventional duct system, even if exhaust gas cannot be completely blocked by the damper 1, the downstream side of the damper 1 is always under negative pressure, so that the downstream side of the damper 1 moves to the upstream side. The phenomenon that the exhaust gas flows backward did not occur. But,
In the exhaust gas re-combustion combined cycle plant, a positive pressure is applied to the downstream side of the damper 1, the exhaust gas leaks from the downstream side of the damper 1 to the upstream side, and the duct 5 on the upstream side of the damper 1
Also, there is a problem that the high temperature gas staying in the gas heater 6 is pushed back and the combustion equipment such as the gas turbine 7 is damaged. As a conventional technique, for example, Japanese Patent Laid-Open No.
Examples include a method for controlling ventilation of exhaust gas in a flue gas desulfurization facility described in JP-A 2-41514.

【0003】[0003]

【発明が解決しようとする課題】上述したごとく、従来
のガスタービン排ガス出口ダクト系においては、図3に
示すように、排ガス遮断用のダンパ1の後流側は、常に
負圧となるために、ダンパ1の後流側から前流側へ流体
がリークする現象は生じなかった。しかし、排気再燃コ
ンバインドサイクルプラントにおいては、ダンパ後流側
が正圧となる場合があって、ダンパ1の後流側から前流
側へ排ガスがリークし、ダンパ1の前流側のダクト5お
よびガスヒータ6内に滞留している高温ガスがガスター
ビン7の側へ押し戻される、いわゆる逆流現象が生じガ
スタービン7が損傷を受けるという問題があった。
As described above, in the conventional gas turbine exhaust gas outlet duct system, as shown in FIG. 3, the downstream side of the exhaust gas shut-off damper 1 always has a negative pressure. The phenomenon that the fluid leaked from the downstream side to the upstream side of the damper 1 did not occur. However, in the exhaust gas re-combustion combined cycle plant, the pressure on the downstream side of the damper may be positive, and the exhaust gas leaks from the downstream side of the damper 1 to the upstream side, and the duct 5 and the gas heater on the upstream side of the damper 1 may be leaked. There is a problem in that the high temperature gas staying in 6 is pushed back to the gas turbine 7 side, a so-called backflow phenomenon occurs, and the gas turbine 7 is damaged.

【0004】本発明の目的は、排気再燃コンバインドサ
イクルプラント等の排ガス出口ダクト系において、ガス
タービン等の燃焼機器の運転停止時に、排ガス遮断用の
ダンパの後流側の正圧の排ガスがダンパからリークして
ダンパの前流側のダクトに流入しても、ダンパの前流側
のダクトおよびガスヒータ(熱交換器)部に滞留する高
温ガスが押し戻され逆流することがなく、ガスタービン
等の燃焼機器が損傷を受けることのない高温ガス逆流防
止装置を提供することにある。
An object of the present invention is, in an exhaust gas outlet duct system of an exhaust gas re-combustion combined cycle plant or the like, when the operation of a combustion device such as a gas turbine is stopped, a positive pressure exhaust gas on the wake side of the damper for shutting off the exhaust gas is discharged from the damper. Even if the gas leaks and flows into the duct on the upstream side of the damper, the high-temperature gas staying in the duct on the upstream side of the damper and the gas heater (heat exchanger) is not pushed back and does not flow backward, and combustion of gas turbines, etc. It is an object of the present invention to provide a high temperature gas backflow prevention device that does not damage the equipment.

【0005】[0005]

【課題を解決するための手段】上記本発明の目的を達成
するために、本発明は特許請求の範囲に記載されたよう
な構成とするものである。すなわち、本発明は請求項1
に記載のように、ガスタービン等の燃焼機器の排ガス出
口ダクトに設けられた排ガスを加熱する熱交換器と、該
熱交換器の後流に、上記燃焼機器の運転停止時にボイラ
からの燃焼排ガスを遮断するダンパを少なくとも備えた
ガスタービンの排ガス出口ダクトにおいて、上記燃焼機
器の運転停止時に、閉鎖した上記ダンパの後流側から前
流側のダクト内にリークするガス流により、上記ダンパ
の前流側のダクト内および熱交換器部に残留する高温ガ
スが上記燃焼機器に押し戻されるのを防止するために、
上記ダンパの前流側のダクトの天井部に、大気との温度
差による煙突効果によって高温ガスを系外に排出する構
造の排気手段を少なくとも設けた高温ガス逆流防止装置
とするものである。そして、本発明は具体的に、請求項
2に記載のように、請求項1において、ダンパの前流側
のダクトに、大気との温度差による煙突効果によって高
温ガスを系外に排出する構造の排気手段は、上記ダクト
の天井部に、ガスタービン等の燃焼機器の運転時に閉鎖
するガス抜きバルブを少なくとも2個直列に接続して設
け、かつ上記ガス抜きバルブ間に、ガスタービンの運転
時に、シール用の空気を供給し閉鎖したガス抜きバルブ
からダクト内の高温ガスが大気中にリークするのを防止
するシールエアバルブを連結して設け、上記燃焼機器の
運転停止時には、上記シールエアバルブを全閉にすると
共に、上記ガス抜きバルブを全開操作する手段を少なく
とも設けた構造とするものである。
In order to achieve the above-mentioned object of the present invention, the present invention has a structure as described in the claims. That is, the present invention relates to claim 1.
As described in, a heat exchanger for heating the exhaust gas provided in the exhaust gas outlet duct of the combustion equipment such as a gas turbine, and the wake of the heat exchanger, the combustion exhaust gas from the boiler when the combustion equipment is stopped. In the exhaust gas outlet duct of the gas turbine having at least a damper for shutting off the damper, when the operation of the combustion equipment is stopped, the gas flow leaking from the wake side of the closed damper into the duct of the front side causes the front side of the damper. In order to prevent the high temperature gas remaining in the duct on the flow side and in the heat exchanger section from being pushed back to the combustion device,
The hot gas backflow prevention device is provided with at least exhaust means having a structure for discharging hot gas to the outside of the system by a chimney effect due to a temperature difference from the atmosphere on the ceiling of the duct on the upstream side of the damper. Then, the present invention is, as described in claim 2, specifically, a structure according to claim 1, wherein the duct on the upstream side of the damper discharges the high temperature gas out of the system by a stack effect due to a temperature difference from the atmosphere. The exhaust means is provided with at least two degassing valves connected in series to the ceiling of the duct when the combustion equipment such as a gas turbine is in operation, and between the degassing valves when the gas turbine is in operation. , A sealing air valve is connected to prevent the hot gas in the duct from leaking into the atmosphere from the gas vent valve that is closed by supplying the sealing air. The structure is such that it is closed and at least means for fully opening the gas vent valve is provided.

【0006】また、本発明は請求項3に記載のように、
請求項2において、ガス抜きバルブの高温ガスの系外へ
の排出部に換気ファンを直列に設けた構造とするもので
ある。
Further, according to the present invention, as described in claim 3,
In the second aspect of the present invention, a ventilation fan is provided in series at a portion of the degassing valve for discharging the high temperature gas out of the system.

【0007】また、本発明は請求項4に記載のように、
代表的な燃焼機器としてガスタービンを用いた排気再燃
コンバインドサイクルプラントにおける高温ガス逆流防
止装置とするものである。
Further, according to the present invention, as described in claim 4,
This is a hot gas backflow prevention device in an exhaust gas recombustion combined cycle plant using a gas turbine as a typical combustion device.

【0008】[0008]

【作用】本発明の高温ガス逆流防止装置は、請求項1に
記載のように、ガスタービン等の燃焼機器の運転停止時
において、閉鎖した排ガス出口ダンパの後流側が正圧と
なることが予想される場合において、ダンパの後流側か
ら前流側にリークする排ガス流による高温ガスの逆流を
防止するために、大気との温度差による煙突効果によっ
て高温ガスを系外に排出する構造の排気手段を、ダンパ
の前流側のダクトの天井部に設けているので、これを開
放することにより容易に高温排ガスの逆流を防止するこ
とができ、ガスタービン等の燃焼機器の損傷を効果的に
防止することができる。また、本発明は請求項2に記載
のように、ダンパの前流側のダクトに、大気との温度差
による煙突効果によって高温ガスを系外に排出する構造
の排気手段として、上記ダクトの天井部に、ガスタービ
ン等の燃焼機器の運転時に閉鎖するガス抜きバルブを少
なくとも2個直列に接続して設け、かつ上記ガス抜きバ
ルブ間に、燃焼機器の運転時にシール用の空気を供給し
閉鎖したガス抜きバルブから高温ガスの大気中へのリー
クを防止するシールエアバルブを連結して設け、上記燃
焼機器の運転停止時には上記シールエアバルブを全閉に
すると共に、上記ガス抜きバルブを全開操作する手段を
少なくとも設けた高温ガス逆流防止装置とすることによ
り、ガスタービン等の燃焼機器の運転時には、ガス抜き
バルブからの高温ガスの大気中へのリークをシールエア
バルブの空気によってシールし、ガスタービン等の燃焼
機器の運転停止時には、シールエアバルブを全閉にする
と共に、ガス抜きバルブを全開操作することにより、ダ
ンパの後流側が正圧となる場合において、ダンパの前流
側ダクトの高温ガスと共に、ダンパからのリーク排ガス
を系外へ排出することができ、ダンパのリークガスによ
るダンパ前流側のダクトの高温ガスの逆流を効果的に防
止することができ、排気再燃コンバインドサイクルプラ
ントにおけるガスタービン等の燃焼機器の損傷を未然に
防ぐことができる。また、本発明は請求項3に記載のよ
うに、請求項2におけるガス抜きバルブの高温ガス排出
部に、高温ガスと大気との温度差による煙突効果が小さ
く高温ガスを系外に十分に排気できない時には、換気フ
ァンにより強制的に系外に排出する手段を用いるもので
ある。また、本発明は請求項4に記載のように、排気再
燃コンバインドサイクルプラントにおけるガスタービン
等の燃焼機器の損傷を未然に防ぐことができる顕著な効
果を有するものである。
According to the hot gas backflow prevention apparatus of the present invention, as described in claim 1, when the operation of the combustion equipment such as the gas turbine is stopped, the closed exhaust gas outlet damper is expected to have a positive pressure on the downstream side. In this case, in order to prevent the hot gas from flowing backward due to the exhaust gas flow that leaks from the downstream side of the damper to the upstream side, the exhaust of the structure that discharges the high temperature gas out of the system by the stack effect due to the temperature difference from the atmosphere. Since the means is provided at the ceiling of the duct on the upstream side of the damper, it is possible to easily prevent the backflow of high-temperature exhaust gas by opening it, and effectively prevent damage to combustion equipment such as a gas turbine. Can be prevented. Further, according to the present invention, as described in claim 2, in the duct on the upstream side of the damper, as a discharge means of a structure for discharging high temperature gas out of the system by a chimney effect due to a temperature difference from the atmosphere, the ceiling of the duct is At least two degassing valves that are closed when the combustion equipment such as a gas turbine is operating are connected in series in the section, and air for sealing is supplied between the degassing valves when the combustion equipment is operating and closed. A seal air valve that prevents leakage of high-temperature gas from the gas vent valve to the atmosphere is provided in a linked manner.When the combustion equipment is not operating, the seal air valve is fully closed, and a means for fully opening the gas vent valve is provided. By using at least the hot gas backflow prevention device provided, leakage of hot gas from the gas vent valve into the atmosphere during operation of combustion equipment such as gas turbines. Sealing with the air of the seal air valve, when the operation of the combustion equipment such as a gas turbine is stopped, the seal air valve is fully closed and the gas vent valve is fully opened, so that the positive pressure is generated on the downstream side of the damper. The leaked exhaust gas from the damper can be discharged to the outside of the system together with the hot gas in the duct on the upstream side of the damper, and the backflow of the hot gas in the duct on the upstream side of the damper due to the leaked gas from the damper can be effectively prevented. It is possible to prevent damage to combustion equipment such as a gas turbine in an exhaust gas re-combustion combined cycle plant. Further, according to the present invention, as described in claim 3, the chimney effect due to the temperature difference between the hot gas and the atmosphere is small in the hot gas discharge part of the gas vent valve according to claim 2, and the hot gas is sufficiently exhausted out of the system. When it is not possible, a ventilation fan is used to forcibly discharge it outside the system. Further, as described in claim 4, the present invention has a remarkable effect of preventing damage to the combustion equipment such as the gas turbine in the exhaust gas re-combustion combined cycle plant.

【0009】[0009]

【実施例】以下に本発明の実施例を挙げ、図面を用いて
さらに詳細に説明する。図1は、排気再燃コンバインド
サイクルプラントにおいて、本発明の高温ガス逆流防止
装置を設けた場合の配管系を示す模式図である。図にお
いて、ガスタービン7を運転した後の運転休止時におい
て、ダンパ1およびシールエアバルブ2を閉止すると共
に、ガス抜きバルブ(A)3およびガス抜きバルブ
(B)4を開放して、ダクト5およびガスヒータ(熱交
換器)6内に溜った高温ガスと、ダンパ1からリークし
てくる高温ガスを系外へ排出させる構造になっている。
ここで、図1を用いて、本発明の排気再燃コンバインド
サイクルプラントにおけるダクト内の高温ガス逆流防止
機構について説明する。ガスタービン7の排ガスは、ダ
クト5に設けられている熱交換器(ガスヒータ)6と、
ガスタービン7の停止時にボイラからの燃焼排ガスを遮
断するダンパ1を通してボイラへ供給される。本発明の
高温ガス逆流防止装置は、ガスヒータ6と、ダンパ1の
間のダクト5に設置されており、ガス抜きバルブ(A)
3、ガス抜きバルブ(B)4およびシールエアバルブ2
により構成されている。高温ガス逆流防止装置は、ガス
タービン7の停止によって閉鎖するダンパ1の閉鎖信号
により、シールエアバルブが閉鎖されると共に、ガス抜
きバルブ(A)3およびガス抜きバルブ(B)4を開放
して、ダクト5およびガスヒータ6内に滞留した高温ガ
スと、大気との温度差による煙突効果を利用して高温ガ
スを系外へ排出するものである。また、ガスタービン起
動時には、ダンパ1の開放信号により、シールエアバル
ブ2を開放してシールエアを供給すると共に、ガス抜き
バルブ(A)3およびガス抜きバルブ(B)4を閉鎖
し、ダクト5およびガスヒータ6を流れる高温ガスがガ
ス抜きバルブ(A)3から漏れないようにしている。従
来のガスタービン排ガス出口ダクト系におけるダンパ1
の後流側は、常時負圧となっていたため、ダンパ1によ
り排ガスを完全に遮断できなくても、ダンパ1の後流側
から前流側のダクトへの排ガスの逆流は生じなかった。
しかし、排気再燃コンバインドサイクルプラントにおい
ては、ガスタービン7の運転停止時にダンパ1の後流側
が正圧となることが予想され、それによってダンパ1の
後流側から前流側への排ガスの逆流が起こり、この排ガ
ス流によりダンパ1の前流側のダクト5およびガスヒー
タ6内に滞留した高温ガスが押し戻されガスタービン7
の機器が損傷を受けることになる。したがって、ガスタ
ービン7の停止時には、ガス抜きバルブ(A)3および
ガス抜きバルブ(B)4を開放して、煙突効果により高
温ガスを系外へ排出する構造にしている。このように、
ガスヒータ6とダンパ1の間のダクト5に、ガス抜きバ
ルブ(A)3、ガス抜きバルブ(B)4およびシールエ
アバルブ2を設置することにより、タービン7停止時
に、ダンパ1の後流側のダクトが正圧になってもタービ
ン7等の燃焼機器の損傷を防止することができる。次
に、本発明の他の実施例を図2に示す。ガス抜きバルブ
(B)4の後流に、換気ファン8を設置するものであ
る。本実施例の特長は、ダクト5およびガスヒータ6内
に滞留した高温ガスと大気との温度差による煙突効果が
小さく、高温ガスを系外へ十分に排気できない場合、換
気ファン8により強制的にガスを系外へ排出することが
できる。
Embodiments of the present invention will be described below in more detail with reference to the drawings. FIG. 1 is a schematic diagram showing a piping system in a case where the hot gas backflow prevention device of the present invention is provided in an exhaust gas reburn combined cycle plant. In the figure, when the operation is stopped after the gas turbine 7 is operated, the damper 1 and the seal air valve 2 are closed, the gas vent valve (A) 3 and the gas vent valve (B) 4 are opened, and the duct 5 and The structure is such that the high temperature gas accumulated in the gas heater (heat exchanger) 6 and the high temperature gas leaking from the damper 1 are discharged to the outside of the system.
Here, the hot gas backflow prevention mechanism in the duct in the exhaust gas reburn combined cycle plant of the present invention will be described with reference to FIG. The exhaust gas from the gas turbine 7 is supplied to the heat exchanger (gas heater) 6 provided in the duct 5,
When the gas turbine 7 is stopped, it is supplied to the boiler through a damper 1 that blocks combustion exhaust gas from the boiler. The high temperature gas backflow prevention device of the present invention is installed in the duct 5 between the gas heater 6 and the damper 1, and the degassing valve (A) is provided.
3, degassing valve (B) 4 and seal air valve 2
It consists of. In the high temperature gas backflow prevention device, the seal air valve is closed and the gas vent valve (A) 3 and the gas vent valve (B) 4 are opened by the closing signal of the damper 1 which is closed by stopping the gas turbine 7. The high temperature gas accumulated in the duct 5 and the gas heater 6 is discharged from the system by utilizing the stack effect due to the temperature difference between the high temperature gas and the atmosphere. Further, at the time of starting the gas turbine, the seal air valve 2 is opened to supply the seal air by the opening signal of the damper 1, the gas vent valve (A) 3 and the gas vent valve (B) 4 are closed, and the duct 5 and the gas heater are closed. The high temperature gas flowing through 6 is prevented from leaking through the gas vent valve (A) 3. Damper 1 in a conventional gas turbine exhaust gas outlet duct system
Since the negative pressure was always present on the wake side, the exhaust gas did not flow backward from the wake side of the damper 1 to the duct on the front side even if the exhaust gas could not be completely blocked by the damper 1.
However, in the exhaust gas re-combustion combined cycle plant, it is expected that the wake side of the damper 1 becomes a positive pressure when the operation of the gas turbine 7 is stopped. Due to this exhaust gas flow, the high temperature gas that has accumulated in the duct 5 and the gas heater 6 on the upstream side of the damper 1 is pushed back, and the gas turbine 7
Equipment will be damaged. Therefore, when the gas turbine 7 is stopped, the degassing valve (A) 3 and the degassing valve (B) 4 are opened so that the high temperature gas is discharged to the outside of the system by the stack effect. in this way,
By installing the gas vent valve (A) 3, the gas vent valve (B) 4 and the seal air valve 2 in the duct 5 between the gas heater 6 and the damper 1, the duct on the downstream side of the damper 1 when the turbine 7 is stopped Even if the pressure becomes positive, it is possible to prevent damage to the combustion equipment such as the turbine 7. Next, another embodiment of the present invention is shown in FIG. A ventilation fan 8 is installed downstream of the gas vent valve (B) 4. The feature of this embodiment is that the chimney effect due to the temperature difference between the high temperature gas staying in the duct 5 and the gas heater 6 and the atmosphere is small, and when the high temperature gas cannot be exhausted to the outside of the system, the ventilation fan 8 forcibly gasses it. Can be discharged out of the system.

【0010】[0010]

【発明の効果】以上詳細に説明したごとく、本発明の高
温ガス逆流防止装置によれば、排ガスの完全な封鎖が不
可能なダンパの後流側から前流側へリークしてくる排ガ
スによりダンパ前流側の高温ガスが押し戻され逆流する
ことにより引き起こされるダンパ前流側のガスタービン
等の燃焼機器の損傷を未然に防止できる顕著な効果があ
る。
As described in detail above, according to the high temperature gas backflow prevention apparatus of the present invention, the damper that cannot completely block the exhaust gas leaks from the downstream side to the upstream side of the damper. The damper has a remarkable effect of preventing damage to the combustion equipment such as the gas turbine on the upstream side caused by the high temperature gas on the upstream side being pushed back and flowing backward.

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明の実施例で例示した高温ガス逆流防止装
置の構成を示す模式図。
FIG. 1 is a schematic diagram showing the configuration of a high temperature gas backflow prevention device exemplified in an embodiment of the present invention.

【図2】本発明の実施例で例示した高温ガス逆流防止装
置の他の構成を示す模式図。
FIG. 2 is a schematic diagram showing another configuration of the high temperature gas backflow prevention device exemplified in the embodiment of the present invention.

【図3】従来のガスタービン出口排ガスダクト系の機器
の配置を示す模式図。
FIG. 3 is a schematic diagram showing an arrangement of devices of a conventional gas turbine outlet exhaust gas duct system.

【符号の説明】[Explanation of symbols]

1…ダンパ 2…シールエアバルブ 3…ガス抜きバルブ(A) 4…ガス抜きバルブ(B) 5…ダクト 6…ガスヒータ(熱交換器) 7…ガスタービン 8…換気ファン 1 ... Damper 2 ... Seal air valve 3 ... Gas vent valve (A) 4 ... Gas vent valve (B) 5 ... Duct 6 ... Gas heater (heat exchanger) 7 ... Gas turbine 8 ... Ventilation fan

───────────────────────────────────────────────────── フロントページの続き (72)発明者 伊賀上 克彦 広島県呉市宝町6番9号 バブコック日立 株式会社呉工場内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuhiko Igaue 6-9 Takaracho, Kure City, Hiroshima Prefecture Babcock Hitachi Kure Factory

Claims (4)

【特許請求の範囲】[Claims] 【請求項1】燃焼機器の排ガス出口ダクトに設けられた
排ガスを加熱する熱交換器と、該熱交換器の後流に、上
記燃焼機器の運転停止時に、ボイラからの燃焼排ガスを
遮断するダンパを少なくとも備えた排ガス出口ダクトに
おいて、上記燃焼機器の運転停止時に、閉鎖した上記ダ
ンパの後流側から前流側のダクト内にリークするガス流
により、上記ダンパの前流側のダクト内および熱交換器
部に残留する高温ガスが上記燃焼機器に押し戻されるの
を防止するために、上記ダンパの前流側のダクトの天井
部に、大気との温度差による煙突効果によって高温ガス
を系外に排出する構造の排気手段を少なくとも設けてな
ることを特徴とする高温ガス逆流防止装置。
1. A heat exchanger for heating exhaust gas provided in an exhaust gas outlet duct of a combustion device, and a damper for shutting off the combustion exhaust gas from a boiler at the downstream of the heat exchanger when the operation of the combustion device is stopped. In the exhaust gas outlet duct including at least, when the operation of the combustion equipment is stopped, the gas flow leaking from the closed downstream side of the damper into the upstream side duct causes the inside of the upstream side duct of the damper and the heat In order to prevent the high temperature gas remaining in the exchanger from being pushed back to the combustion equipment, the high temperature gas is removed from the system by the stack effect due to the temperature difference with the atmosphere at the ceiling of the duct on the upstream side of the damper. A high temperature gas backflow prevention device comprising at least an exhaust means having a structure for discharging.
【請求項2】請求項1において、ダンパの前流側のダク
トに、大気との温度差による煙突効果によって高温ガス
を系外に排出する構造の排気手段は、上記ダクトの天井
部に、燃焼機器の運転時に閉鎖するガス抜きバルブを少
なくとも2個直列に接続して設け、かつ上記ガス抜きバ
ルブ間に、燃焼機器の運転時に、閉鎖したガス抜きバル
ブから高温ガスが大気中にリークするのを防止するため
のシール用空気を供給するシールエアバルブを連結して
設け、上記燃焼機器の運転停止時には、上記シールエア
バルブを全閉にすると共に、上記ガス抜きバルブを全開
操作する手段を少なくとも設けてなることを特徴とする
高温ガス逆流防止装置。
2. The exhaust means according to claim 1, wherein the duct on the upstream side of the damper has a structure for discharging high temperature gas to the outside of the system by a chimney effect due to a temperature difference from the atmosphere, the exhaust means has At least two degassing valves that are closed during operation of the equipment are provided in series, and between the degassing valves, high temperature gas is prevented from leaking to the atmosphere from the closed degassing valve during operation of the combustion equipment. A seal air valve for supplying sealing air for prevention is provided so as to be connected, and at least means for fully closing the seal air valve and fully opening the gas vent valve when the operation of the combustion equipment is stopped. A high temperature gas backflow prevention device characterized by the above.
【請求項3】請求項2において、ガス抜きバルブの高温
ガスの系外への排出部に換気ファンを直列に設けてなる
ことを特徴とする高温ガス逆流防止装置。
3. The high temperature gas backflow prevention device according to claim 2, wherein a ventilation fan is provided in series at a portion of the gas vent valve for discharging the high temperature gas out of the system.
【請求項4】請求項1ないし請求項3のいずれか1項に
おいて、燃焼機器は、排気再燃コンバインドサイクルプ
ラントにおけるガスタービンであることを特徴とする高
温ガス逆流防止装置。
4. The high-temperature gas backflow prevention device according to claim 1, wherein the combustion device is a gas turbine in an exhaust gas recombustion combined cycle plant.
JP1223695A 1995-01-30 1995-01-30 Preventing device of backflow of high temperature gas Pending JPH08200650A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP1223695A JPH08200650A (en) 1995-01-30 1995-01-30 Preventing device of backflow of high temperature gas

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1223695A JPH08200650A (en) 1995-01-30 1995-01-30 Preventing device of backflow of high temperature gas

Publications (1)

Publication Number Publication Date
JPH08200650A true JPH08200650A (en) 1996-08-06

Family

ID=11799743

Family Applications (1)

Application Number Title Priority Date Filing Date
JP1223695A Pending JPH08200650A (en) 1995-01-30 1995-01-30 Preventing device of backflow of high temperature gas

Country Status (1)

Country Link
JP (1) JPH08200650A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013092563A1 (en) 2011-12-21 2013-06-27 Ge Energy Products France Snc Vent for a gaseous fuel supply circuit of a gas turbine, and associated method

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013092563A1 (en) 2011-12-21 2013-06-27 Ge Energy Products France Snc Vent for a gaseous fuel supply circuit of a gas turbine, and associated method

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