JP2004028558A

JP2004028558A - Exhaust gas temperature reducing method using hot water and its device

Info

Publication number: JP2004028558A
Application number: JP2003118325A
Authority: JP
Inventors: Kazuhiro Sato; 佐藤　和宏
Original assignee: Takuma Co Ltd
Current assignee: Takuma Co Ltd
Priority date: 2002-05-07
Filing date: 2003-04-23
Publication date: 2004-01-29

Abstract

<P>PROBLEM TO BE SOLVED: To constantly and stably spray a necessary amount of pressurized hot water and prevent dispersion of atomized particle size even when a spray amount of the pressurized hot water is reduced or a temperature of the pressurized hot water drops in activation and deactivation of a combustion device in regard to temperature reducing method for exhaust gas using the pressurized hot water. <P>SOLUTION: In the exhaust gas temperature reducing method using the hot water in a combustion furnace or a boiler facility using the pressurized hot water with a temperature higher than a boiling point of water under atmospheric pressure as temperature reducing water and spraying it into the exhaust gas, a temperature reducing water spray nozzle spraying the hot water into the exhaust gas as the temperature reducing water can provide both two fluid spraying and one fluid spraying, and a nozzle conduit attached with the temperature reducing water spray nozzle in a tip is a double wall structure. The hot water is sprayed into the exhaust gas by a two fluid spraying method by passing the hot water through an outer passage of the nozzle conduit with the double wall structure, and passing pressurized air through an inner passage of the nozzle conduit when a pressure of the hot water drops to a vicinity of a saturation vapor pressure at that temperature or a temperature of the pressurized hot water drops to a saturation temperature or less at a pressure of its spray area. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、ごみ焼却炉やボイラ等の燃焼装置から排出される排ガスの処理に利用されるものであり、加圧熱水を排ガス内へ噴霧するようにした排ガス減温システムに於いて、燃焼装置の立上げや立下げ時等の加圧熱水の噴霧量が減少したような場合や、加圧熱水の温度が低下したような場合でも、安定した所要量の加圧熱水の噴霧を行なえると共に、噴霧粒の粒径の増大を有効に防止できるようにした熱水を利用した排ガス減温方法とその装置に関するものである。
【０００２】
【従来の技術】
出願人は先きに、図５に示す如き熱水を利用した排ガス減温方法を開発し、これを特開２０００−２７４６５４号として公開している。
即ち図５に於いて、１はガス冷却室、１ａは排ガス入口、１ｂは排ガス出口、１ｃは灰出口、１ｄは灰出フィーダー、３は減温水量制御弁、４は温度制御装置、４ａは出口側排ガス温度検出器、４ｂは入口側排ガス温度検出器、１２は熱水タンク、１３はポンプ、１４は減温水ノズル、１５は配管路、Ｇｈは高温排ガス、Ｇｌは低温排ガス、Ｃは灰、Ｗｔは加圧熱水、Ｗは水、Ｓは加熱用蒸気であり、大気圧に於ける水の沸点（１００℃）よりも高温に保持された加圧熱水を、減温水ノズル１４から高温排ガスＧｈ内へ噴霧して短時間内に急速蒸発させることにより、加圧熱水の蒸発潜熱と水蒸気の顕熱により高温排ガスＧｈを減温するよう構成されている。
【０００３】
上記図５に示した熱水を利用した排ガス減温方法は、従前の低温水を利用した排ガス減温方法に比較して、▲１▼水滴の付着等によるガス冷却室壁面の損傷や壁面へのダスト堆積等のトラブルが防止できること、▲２▼ガス冷却室の大幅な小型化が図れること及び▲３▼排ガス減温設備の簡素化やランニングコストの引下げが図れること、等の点で優れた実用的効用を奏するものである。
【０００４】
【発明が解決しようとする課題】
しかし、上記図５に示した従前の熱水を利用した排ガス減温方法は解決すべき問題が多く残されており、その中でも、加圧熱水Ｗｔの供給量が減少した場合や、加圧熱水の温度が低下した場合に、減温水ノズル１４からの噴霧量が不安定になり易いことが、早急に解決を要する問題として残されている。
【０００５】
即ち、前記減温水ノズル１４から噴霧する加圧熱水Ｗｔの流量は減温水量制御弁３の開閉制御により制御されている。そのため、都市ごみ焼却炉（燃焼装置）の立上げや立下げ時に、減温水量制御弁３を絞って加圧熱水Ｗｔの噴霧量を減少させると、減温水量制御弁３の流路抵抗の増大と加圧熱水Ｗｔの流量減少とが相俟って、加圧熱水Ｗｔの圧力がその温度に於ける飽和蒸気圧付近にまで低下してしまうことになる。その結果、減温水量制御弁３から減温水ノズル１４までの配管路１５内で加圧熱水Ｗｔの一部が蒸発することになり、減温水ノズル１４からの加圧熱水Ｗｔの噴霧量が不安定になったり、噴霧粒径が大きくなったりする。また、立上げや立下げ時に加圧熱水が得られない場合には、減温効果が悪化したり、噴霧粒径が大きくなったりする。
【０００６】
本願発明は、従前の加圧熱水を利用した排ガス減温方法に於ける上述の如き問題、即ち加圧熱水Ｗｔの供給量が減少した場合や、加圧熱水の温度が低下した場合に、減温水ノズルからの熱水の噴霧量が不安定になったり、噴霧粒径が増大する等の問題を解決せんとするものであり、燃焼装置の立上げや立下げ時等に於いても、常に必要量の加圧熱水を安定して噴霧することができると共に、噴霧粒径の増大もほぼ完全に防止できるようにした熱水を利用した排ガス減温方法とこれに用いる排ガス減温装置を提供するものである。
【０００７】
【課題を解決するための手段】
本願発明の請求項１に記載の発明は、大気圧下で水の沸点よりも高い温度の加圧熱水を減温水として排ガス内へ噴霧するようにした焼却炉やボイラ設備における熱水を利用した排ガス減温方法に於いて、加圧熱水を減温水として排ガス内へ噴霧する減温水噴霧ノズルを二流体噴霧と一流体噴霧の両方が可能な減温水噴霧ノズルとすると共に、加圧熱水の噴霧量の減少時に、減温水量制御弁の下流側に於ける前記加圧熱水の圧力がその温度での飽和蒸気圧の近傍にまで低下したとき、又は加圧熱水の温度がその噴霧場の圧力での飽和温度の近傍にまで低下したときには、前記減温水噴霧ノズルへ加圧空気を流通させ、二流体噴霧方式により排ガス内へ加圧熱水を噴霧するようにしたことを発明の基本構成とするものである。
【０００８】
本願発明の請求項２に記載の発明は、大気圧下で水の沸点よりも高い温度の加圧熱水を減温水として排ガス内へ噴霧するようにした焼却炉やボイラ設備における熱水を利用した排ガス減温方法に於いて、加圧熱水を減温水として排ガス内へ噴霧する減温水噴霧ノズルを二流体噴霧と一流体噴霧の両方が可能な減温水噴霧ノズルとすると共に、先端に減温水噴霧ノズルを取付けしたノズル導管を二重壁構造のノズル導管とし、当該二重壁構造のノズル導管の外側通路に加圧熱水を流通させると共に、当該加圧熱水の圧力がその温度での飽和蒸気圧の近傍にまで低下したとき、又は加圧熱水の温度がその噴霧場の圧力での飽和温度の近傍にまで低下したときには、前記ノズル導管の内側通路に加圧空気を流通させ、二流体噴霧方式により排ガス内へ加圧熱水を噴霧するようにしたことを発明の基本構成とするものである。
【０００９】
請求項３に記載の発明は、請求項１又は請求項２の発明に於いて、加圧熱水を減温水としてガス冷却室又は排ガスダクト内へ噴霧するようにしたものである。
【００１０】
請求項４に記載の発明は、請求項２又は請求項３の発明に於いて、ノズル導管内の加圧熱水の圧力がその温度での飽和蒸気圧＋０．１（ＭＰａＧ）以下に低下したとき、又は加圧熱水の温度がその噴霧場の圧力での飽和温度＋２０℃以下に低下したときにに、加圧空気を流通させるようにしたものである。
【００１１】
請求項５に記載の発明は、請求項２又は請求項３の発明に於いて、二流体噴霧方式のときの加圧空気の流量を、排ガス内へ噴霧する加圧熱水の流量に対して比例させる制御とするようにしたものである。
【００１２】
請求項６に記載の発明は、ガス入口とガス出口とを備えたガス冷却室又は排ガスダクトと、大気圧下で水の沸点よりも高い温度の加圧熱水を供給する加圧熱水の供給源と、加圧熱水の供給源からの加圧熱水をガス冷却室又は排ガスダクト内へ噴霧する減温水噴霧ノズルと、減温水噴霧ノズルへ供給する加圧熱水量を調整する減温水量制御弁と、ガス入口から流入する高温排ガスとガス出口から流出する低温排ガスの何れか一方又は両方の温度検出器と、前記温度検出器からの検出信号により減温水量制御弁を開閉制御する温度制御装置とから成る熱水を利用した排ガス減温装置に於いて、前記減温水噴霧ノズルを一流体噴霧と二流体噴霧の両方が可能な減温水噴霧ノズルとし、また前記減温水噴霧ノズルと減温水量制御弁との間に混合器を設け、当該混合器へ加圧空気制御弁を介設して圧縮空気供給装置を連結し、更に、前記減温水量制御弁の下流側に加圧熱水の圧力検出器及び温度検出器を設け、当該圧力検出器の検出圧力が加圧熱水のその温度での飽和蒸気圧の近傍にまで低下したとき、又は温度検出器の検出温度がその噴霧場の圧力での飽和温度の近傍にまで低下したときに、加圧空気制御装置を介して前記加圧空気制御弁を開閉制御し、二流体噴霧方式により排ガス内へ加圧熱水を噴霧するようにしたことを発明の基本構成とするものである。
【００１３】
本願の請求項７に記載の発明は、ガス入口とガス出口とを備えたガス冷却室又は排ガスダクトと、大気圧下で水の沸点よりも高い温度の加圧熱水を供給する加圧熱水の供給源と、加圧熱水の供給源からの加圧熱水をガス冷却室又は排ガスダクト内へ噴霧する減温水噴霧ノズルと、減温水噴霧ノズルへ供給する加圧熱水量を調整する減温水量制御弁と、ガス入口から流入する高温排ガスとガス出口から流出する低温排ガスの何れか一方又は両方の温度検出器と、前記温度検出器からの検出信号により減温水量制御弁を開閉制御する温度制御装置とから成る熱水を利用した排ガス減温装置に於いて、前記減温水噴霧ノズルを一流体噴霧と二流体噴霧の両方が可能な減温水噴霧ノズルとし、また前記減温水噴霧ノズルと減温水量制御弁間のノズル導管を二重壁構造の導管としてその内側通路を加圧空気の流通路にすると共に外側通路を加圧熱水の通路とし、更に、前記ノズル導管の内側通路へ加圧空気制御弁を介設して圧縮空気供給装置を連結すると共に、前記ノズル導管に外側通路内の加圧熱水の圧力検出器及び温度検出器を設け、当該圧力検出器の検出圧力が加圧熱水のその温度での飽和蒸気圧の近傍にまで低下したとき、又は又は温度検出器の検出温度がその噴霧場の圧力での飽和温度の近傍にまで低下したときには、加圧空気制御装置を介して前記加圧空気制御弁を開閉制御し、二流体噴霧方式により排ガス内へ加圧熱水を噴霧するようにしたことを発明の基本構成とするものである。
【００１４】
請求項８の発明は、請求項６又は請求項８の発明に於いて、圧力検出器の検出圧力が、加圧熱水のその温度での飽和蒸気圧＋０．１（ＭＰａＧ）以下に低下したとき、又は温度検出器の検出温度が、その噴霧場の圧力での飽和温度＋２０℃以下に低下したときに、加圧空気制御弁を開放するようにしたものである。
【００１５】
【発明の実施の形態】
以下、図面に基づいて本発明の実施形態を説明する。
図１は本発明の第１実施形態に係る排ガス減温方法とこれに用いる装置の説明図であり、図に於いて１はガス冷却室、１ａは排ガス入口、１ｂは排ガス出口、１ｃは灰出口、１ｄは灰出フィーダー、２は減温水噴霧ノズル、３は減温水量制御弁、４は温度制御装置、４ａ・４ｂは温度検出器、５は加圧空気制御弁、６は加圧空気制御装置、６ａは圧力検出器、６ｂは加圧熱水の温度検出器、７はノズル導管、Ｇｈは高温排ガス、Ｇｌは低温排ガス、Ｃは灰、Ｗｔは加圧熱水、Ａは加圧空気である。
また、図２は、減温水噴霧ノズル２と減温水量制御弁３との間を連結するノズル導管７の断面図であり、ノズル導管７は外管７ａと内管７ｂとから成る二重壁構造の導管であって、外側通路７ｃを減温水（加圧熱水）Ｗｔが、また内側通路７ｄを加圧空気Ａが夫々流通する。
【００１６】
本発明に於いては、前記減温水噴霧ノズル２として一流体噴霧と二流体噴霧の両方が可能なノズルが使用されており、後述する如く燃焼装置（図示省略）が定常運転中等の加圧熱水Ｗｔの噴霧量が多い場合には、加圧熱水Ｗｔのみを噴霧する一流体噴霧ノズルとして作動される。また、燃焼装置の立上げや立下げ時等の加圧熱水Ｗｔの噴霧量が少ない場合や、加圧熱水Ｗｔの温度が低下した場合には、加圧空気Ａと加圧熱水Ｗｔとを混合噴霧する二流体噴霧ノズルとして作動される。
【００１７】
尚、減温水噴霧ノズル２の構造は、一流体噴霧と二流体噴霧との切換噴霧が可能な構造のものであれば如何なる構造のものであってもよく、図１の実施形態に於いては、減温水噴霧ノズル２の噴出口の手前に於いて加圧熱水Ｗｔの流れの中央部へ加圧空気Ａを混入させ、両者の混合体を噴出口から外方へ向けて噴射させる構造のノズルを使用している。
【００１８】
前記減温水（加圧熱水）Ｗｔは、大気圧下に於ける沸点（１００℃）よりも高温度の水（加圧熱水）であり、その温度における飽和蒸気圧以上の圧力を保持するものである。この加圧熱水Ｗｔの圧力は通常０．１〜１０ＭＰａＧの間に選定されており、廃熱ボイラや熱水貯留タンク等の熱水供給源（図示省略）の設備面から、加圧熱水Ｗｔの圧力は０．３〜１．０ＭＰａＧ位とするのが望ましい。
【００１９】
前記加圧空気Ａの空気源としてはコンプレッサー等が使用されており、その圧力は加圧熱水Ｗｔの圧力に近い値に設定されている。具体的には、加圧空気Ａの圧力は０．１〜１０ＭＰａＧの間、望ましくは０．３〜０．７ＭＰａＧの圧力に設定されている。
【００２０】
尚、図１に於けるガス冷却室１や減温水量制御弁３、温度制御装置４等の構成は、前記特開２０００−２７４６５４号の場合と略同一であるため、ここではその説明を省略する。
また、図１では、ガス冷却室１内に於ける高温排ガスＧｈの減温について記載しているが、本発明を排ガスダクト（図示省略）内に於ける高温排ガスＧｈの減温にも適用できることは勿論である。
更に、図１に於いては、加圧熱水Ｗｔとして通常の水を利用しているが、高温排ガスＧｈ内の酸性ガスを除去するために、アルカリ性溶液等を含んだ水を加圧熱水Ｗｔとしてもよいことは勿論である。
【００２１】
次に、本発明による高温排ガスＧｈの減温について説明する。
図１及び図２を参照して、燃焼装置（図示省略）等が定常運転中であって減温水量（加圧熱水量）が相対的に多い場合には、加圧空気制御弁５は閉鎖されている。その結果、加圧熱水Ｗｔは減温水量制御弁３を通してノズル導管７の外側通路７ｃ内へ導入され、減温水噴霧ノズル２から所謂一流体噴霧方式により高温排ガスＧｈ内へ噴霧される。
【００２２】
尚、加圧熱水Ｗｔの噴霧量は、高温排ガスＧｈの温度検出器４ｂ及び低温排ガスＧｌの温度検出器４ａからの各検出信号により、温度制御装置４を介して減温水量制御弁３の開度制御をすることにより自動調整されており、これによって低温排ガスＧｌの温度が設定範囲内の温度に制御されている。
【００２３】
また、ノズル導管７の外側通路７ａ内を流通する加圧熱水Ｗｔの圧力及び温度は、圧力検出器６ａ及び温度検出器６ｂによって常時検出されており、その各検出信号により加圧空気制御装置６を介して、加圧空気制御弁５が開閉制御される。
【００２４】
具体的には、圧力検出器６ａによる加圧熱水Ｗｔの検出圧力値が、その温度に於ける加圧熱水Ｗｔの飽和蒸気圧Ｐｓの近傍値（例えば、飽和蒸気圧Ｐｓ±１．０（ＭＰａＧ）、望ましくは飽和蒸気圧Ｐｓ＋０．１（ＭＰａＧ）以下の圧力になれば、加圧空気制御弁５を開放してノズル導管７の内側通路７ｄ内へ加圧空気Ａを供給する。
同様に、温度検出器６ｂによる加圧熱水Ｗｔの温度検出値が、加圧熱水Ｗｔの噴霧場の圧力での飽和温度近傍の温度（例えば飽和温度＋２０℃以下の温度）になれば、加圧空気制御弁５を開放してノズル導管７の内側通路７ｄ内へ加圧空気Ａを供給する。
これにより、減温水噴霧ノズル２は二流体方式の噴霧ノズルとして作動することになり、後述するように噴霧量の変動や噴霧粒径の大粒径化が防止されることになる。
【００２５】
例えば、燃焼装置（図示省略）の立上げや立下げ時には、入口側の高温排ガスＧｈの温度や排ガス量が定常運転時の排ガス温度や排ガス量に比較して下降する。その結果、排ガスの減温に必要とする加圧熱水Ｗｔの噴霧量自体も定常運転時の噴霧量に比較して少なくなる。
一方、減温水量制御弁３を絞ることによって加圧熱水Ｗｔの噴霧量を減少させると、制御弁３の部分の流路抵抗が増大して、この部分に於ける圧力損失が増大すると共に、加圧熱水Ｗｔの流通する外側通路７ｃの有効断面積が相当大きいため、絞りによって小流量とされた加圧熱水Ｗｔの一部が外側通路７ｃ内で蒸発することになる。その結果、加圧熱水Ｗｔの圧力は、その温度に於ける飽和蒸気圧近傍或いは飽和蒸気圧よりも低い圧力にまで低下することになる。
【００２６】
ところで、外側通路７ｃ内を流通する加圧熱水Ｗｔの圧力が、その温度に於ける飽和蒸気圧近傍或いは飽和蒸気圧より低い圧力にまで低下すると、減温水噴霧ノズル２から高温排ガスＧｈ内へ噴出される加圧熱水Ｗｔの噴霧量が時間的に脈動すると共に、霧化された加圧熱水Ｗｔの噴霧粒径が大きくなり、結果として噴霧水による高温排ガスＧｈの冷却能力が低下したり、水滴がガス冷却室の壁面に直接当って流下することにより、耐火材の破損やダストの付着・堆積を招くことになる。
【００２７】
そのため、前述の通り減温水量制御弁３の下流側の加圧熱水Ｗｔの圧力が、その温度に於ける飽和蒸気圧近傍にまで低下すると、加圧空気制御弁５を開放して所定流量・圧力の加圧空気Ａを内側通路７ｂ内へ供給し、減温水噴霧ノズル２を二流体噴霧方式のノズルとして作動させる。
即ち、ノズル２の本体内部に於いて、加圧熱水Ｗｔの中央部へその流れ方向と同方向に加圧空気Ａを噴出させ、当該加圧空気Ａの流れの有するエネルギーによって加圧熱水Ｗｔの流れを均一化させると共に、ノズル２からの噴霧粒の粒径を細粒化させる。
【００２８】
尚、図１の実施形態に於いては、減温水量制御弁３より下流側の加圧熱水Ｗｔの圧力（圧力検出器６ａの検出圧力）が、その温度に於ける飽和蒸気圧Ｐｓ＋０．１（ＭＰａＧ）以下の値となった時に加圧空気制御弁５を開放し、圧力が０．３〜０．７ＭＰａＧの所定流量の加圧空気Ａを減温水噴霧ノズル２へ供給するようにしている。
【００２９】
また、図１の実施形態に於いては、圧力検出器６ａにより検出した加圧熱水Ｗｔの圧力により、加圧空気制御装置６を介して加圧空気制御弁５を開又は閉とし、所定圧力・流量の加圧空気Ａを供給（又は供給停止）するだけの制御しか行なっていないが、前記加圧空気制御弁５及び加圧空気制御装置６に温度制御要素を付加することにより、加圧空気Ａの供給量を噴霧する加圧熱水Ｗｔの流量に関連付けて制御する構成とすることも可能である。
【００３０】
更に、図１の実施形態に於いては、二重壁構造のノズル導管７の外側通路７ｃへ加圧熱水Ｗｔを流通させるようにしているため、ノズル導管７の表面温度が常に所謂排ガスＧｈの酸性ガスの酸露点温度よりも高い温度に保持されることになり、結果として排ガスＧｈ内のＨＣｌやＳＯｘなどによるノズル導管７の腐食が有効に防止されることになる。
【００３１】
尚、上記説明に於いては、燃焼装置（図示省略）の立上げや立下げ時に、減温水量制御弁３を絞った場合に生ずる加圧熱水Ｗｔの圧力低下のケースを例に挙げて説明をしているが、燃焼装置（図示省略）の立上げや立下げ時に、加圧熱水Ｗｔの温度が加圧熱水Ｗｔの噴霧場での飽和温度以下に下降したような場合でも、上記の説明と全く同様である。
【００３２】
図３は、本発明の第２実施形態を示すものであり、前記図１に於ける加圧空気制御弁５の下流側に加圧空気量制御弁８を設け、当該加圧空気制御弁８を温度制御装置４を介して減温水量制御弁３と並列的に制御することにより、二流体噴霧時に於ける加圧空気Ａの供給流量を加圧熱水Ｗｔの噴霧量に比例させるようにしたものである。
【００３３】
上述のように、加圧空気Ａの供給流量を加圧熱水Ｗｔの噴霧量に比例させることにより、加圧熱水Ｗｔの噴霧量の少ない二流体噴霧時に於いても、より高度な噴霧量制御が可能となると共に、従前の二流体噴霧方式の場合に比較して、加圧空気Ａの消費量を大幅に削減することが出来る。
【００３４】
図４は、本発明の第３実施形態を示す説明図である。
当該第３実施形態に於いては、減温水量制御弁３の下流側に混合器９を設け、混合器９で加圧熱水Ｗｔと加圧空気Ａとを混合させたあと、両者の混合流体を配管路１０を通して減温水噴霧ノズル２へ供給する構成が採用されている。
【００３５】
尚、当該第３実施形態に於いても、加圧空気制御弁５が開放されるのは、燃焼装置の立上げや立下げ時に、圧力検出器６ａによる加圧熱水Ｗｔの検出圧力値が、加圧熱水Ｗｔのその温度に於ける飽和蒸気圧近傍にまで低下した場合、又は温度検出器６ｂによる加圧熱水Ｗｔの温度がその噴霧場の圧力での飽和温度の近傍にまで低下した場合のみであり、加圧熱水Ｗｔの噴霧量が定常値に近いような場合には、加圧熱水Ｗｔのみを噴霧する所謂一流体噴霧方式により高温排ガスＧｈの減温が行なわれる。
また、当該第３実施形態に於いては、配管路１０が通常の単管でよいことは勿論である。
【００３６】
【発明の効果】
本発明に於いては、減温水噴霧ノズルを一流体噴霧と二流体噴霧の切換え作動が可能な減温水ノズルとし、当該加圧熱水の圧力がその温度に於ける飽和蒸気圧の近傍にまで低下したとき又は、加圧熱水Ｗｔの温度がその噴霧場の圧力での飽和温度の近傍にまで低下したときには、加圧空気の供給による二流体噴霧により加圧熱水を噴霧する構成としている。
その結果、燃焼装置の立上げや立下げ時に於いても、常に安定した状態で必要な量の加圧熱水を排ガス内へ噴霧することが出来ると共に、噴霧粒径が大きくなることも防止でき、排ガス冷却性能の低下及び水滴の流下による壁面耐火材の損傷やダストの堆積等のトラブルを完全に防止することができる。
【００３７】
また、ノズル導管を２重壁構造とすることにより、高温排ガスＧｈ等と接触する部分の酸性ガス腐食が有効に防止されることになり、好都合である。
【００３８】
更に、二流体噴霧時に於ける加圧空気の供給制御を、加圧空気量が加圧熱水噴霧量に比例する制御とすることにより、より高精度な加圧熱水の噴霧量制御と加圧空気の消費量の削減が可能となる。
【００３９】
加えて、本発明に於いては、燃焼装置の立上げや立下げ時のような加圧熱水の噴霧量の減少時や加圧熱水の温度低下時にだけ、二流体噴霧方式により高温排ガスの減温を行なう構成としているため、従前の二流体噴霧方式による排ガス減温方法に比較して、高圧空気の消費量を大幅に押えることが可能となる。
本発明は上述の通り優れた実用的効用を奏するものである。
【図面の簡単な説明】
【図１】本発明の第１実施形態を示すものであり、本発明を排ガス冷却室へ適用した場合の説明図である。
【図２】本発明で使用するノズル導管の断面概要図である。
【図３】本発明の第２実施形態を示すものであり、本発明を排ガス冷却室へ適用した場合の説明図である。
【図４】本発明の第３実施形態を示すものであり、本発明を排ガス冷却室へ適用した場合の説明図である。
【図５】従前の熱水を利用した排ガス減温方法の説明図である。
【符号の説明】
Ｇｈは高温排ガス、Ｇｌは低温排ガス、Ｗｔは加圧熱水、Ａは加圧空気、Ｃは灰、１はガス冷却室、１ａは排ガス入口、１ｂは排ガス出口、１ｃは灰出口、１ｄは灰出フィーダー、２は減温水噴霧ノズル、３は減温水量制御弁、４は温度制御装置、４ａ・４ｂは温度検出器、５は加圧空気制御弁、６は加圧空気制御装置、６ａは圧力検出器、６ｂは温度検出器、７はノズル導管、７ａは外管、７ｂは内管、７ｃは外側通路、７ｄは内側通路、８は加圧空気量制御弁、９は混合器、１０は配管路。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is used for treating exhaust gas discharged from a combustion device such as a refuse incinerator or a boiler, and is used in an exhaust gas temperature reduction system in which pressurized hot water is sprayed into the exhaust gas. Even when the spray amount of pressurized hot water decreases when the equipment is started or shut down, or when the temperature of pressurized hot water decreases, a stable required amount of pressurized hot water is sprayed. The present invention relates to a method and a device for reducing the temperature of exhaust gas using hot water, which can effectively prevent an increase in the particle size of spray particles.
[0002]
[Prior art]
The applicant has previously developed a method for reducing the temperature of exhaust gas using hot water as shown in FIG. 5, and has disclosed this method as JP-A-2000-274654.
That is, in FIG. 5, 1 is a gas cooling chamber, 1a is an exhaust gas inlet, 1b is an exhaust gas outlet, 1c is an ash outlet, 1d is an ash feeder, 3 is a dewatering water amount control valve, 4 is a temperature control device, and 4a is Outlet-side exhaust gas temperature detector, 4b is the inlet-side exhaust gas temperature detector, 12 is a hot water tank, 13 is a pump, 14 is a reduced temperature water nozzle, 15 is a pipeline, Gh is high-temperature exhaust gas, Gl is low-temperature exhaust gas, and C is ash. , Wt is pressurized hot water, W is water, and S is heating steam. Pressurized hot water maintained at a temperature higher than the boiling point (100 ° C.) of water at atmospheric pressure is discharged from the de-heated water nozzle 14. The high-temperature exhaust gas Gh is configured to be sprayed into the high-temperature exhaust gas Gh and rapidly evaporated within a short time, so that the high-temperature exhaust gas Gh is cooled by the latent heat of vaporization of the pressurized hot water and the sensible heat of steam.
[0003]
The exhaust gas temperature reduction method using hot water shown in FIG. 5 is different from the conventional exhaust gas temperature reduction method using low-temperature water in (1) damage to the wall of the gas cooling chamber due to adhesion of water droplets and the like. It is superior in that it can prevent troubles such as dust accumulation in the air, (2) can greatly reduce the size of the gas cooling chamber, and (3) can simplify the exhaust gas temperature reduction equipment and reduce the running cost. It has practical utility.
[0004]
[Problems to be solved by the invention]
However, the conventional exhaust gas temperature reducing method using hot water shown in FIG. 5 has many problems to be solved. Among them, when the supply amount of pressurized hot water Wt is reduced, When the temperature of the hot water decreases, the amount of spray from the desuperheated water nozzle 14 tends to be unstable, which remains as a problem that needs to be solved immediately.
[0005]
That is, the flow rate of the pressurized hot water Wt sprayed from the deheated water nozzle 14 is controlled by opening and closing the deheated water control valve 3. Therefore, when the municipal solid waste incinerator (combustion device) is started up or shut down, the amount of spray of the pressurized hot water Wt is reduced by squeezing the dewatering water amount control valve 3. Together with the decrease in the flow rate of the pressurized hot water Wt, the pressure of the pressurized hot water Wt decreases to near the saturated vapor pressure at that temperature. As a result, part of the pressurized hot water Wt evaporates in the piping 15 from the deheated water amount control valve 3 to the deheated water nozzle 14, and the spray amount of the pressurized hot water Wt from the deheated water nozzle 14 Becomes unstable or the spray particle size becomes large. If pressurized hot water cannot be obtained at the time of startup or shutdown, the effect of reducing the temperature will deteriorate or the spray particle size will increase.
[0006]
The invention of the present application has the above-mentioned problems in the conventional exhaust gas temperature reduction method using pressurized hot water, that is, when the supply amount of the pressurized hot water Wt is reduced or when the temperature of the pressurized hot water is reduced. In addition, the problem that the spray amount of hot water from the desuperheater nozzle becomes unstable or the spray particle diameter increases is not solved. In addition, the required amount of pressurized hot water can always be sprayed stably, and the exhaust gas temperature reduction method using hot water, which can almost completely prevent the increase in spray particle size, and the exhaust gas A heating device is provided.
[0007]
[Means for Solving the Problems]
The invention according to claim 1 of the present invention utilizes hot water in an incinerator or a boiler facility in which pressurized hot water having a temperature higher than the boiling point of water under atmospheric pressure is sprayed as desuperheated water into exhaust gas. In the exhaust gas temperature reduction method, the desuperheated water spray nozzle that sprays the pressurized hot water as desuperheated water into the exhaust gas is replaced with a desuperheated water spray nozzle that can perform both two-fluid spray and one-fluid spray. When the spray amount of water decreases, the pressure of the pressurized hot water downstream of the desuperheated water amount control valve decreases to near the saturated vapor pressure at that temperature, or the temperature of the pressurized hot water decreases. When the temperature drops to near the saturation temperature at the spraying field pressure, pressurized air is circulated to the desuperheated water spray nozzle, and pressurized hot water is sprayed into the exhaust gas by a two-fluid spray method. This is a basic configuration of the present invention.
[0008]
The invention described in claim 2 of the present invention utilizes hot water in an incinerator or a boiler facility in which pressurized hot water having a temperature higher than the boiling point of water at atmospheric pressure is sprayed into exhaust gas as desuperheated water. In the exhaust gas temperature reduction method adopted above, the temperature-reduced water spray nozzle that sprays pressurized hot water as temperature-reduced water into the exhaust gas was replaced with a temperature-reduced water spray nozzle that can perform both two-fluid spray and single-fluid spray, and reduced to the tip. The nozzle conduit fitted with the hot water spray nozzle is a double-walled nozzle conduit, and pressurized hot water flows through the outer passage of the double-walled nozzle conduit. When the temperature of the pressurized hot water has dropped to near the saturation temperature at the pressure of the spray station, or when the temperature of the pressurized hot water has dropped to near the saturated vapor pressure of In exhaust gas by two-fluid spray method It is an basic configuration of the invention that was to spray pressurized hot water.
[0009]
According to a third aspect of the present invention, in the first or second aspect, the pressurized hot water is sprayed into the gas cooling chamber or the exhaust gas duct as desuperheated water.
[0010]
According to a fourth aspect of the present invention, in the second or third aspect of the present invention, the pressure of the pressurized hot water in the nozzle conduit is reduced to a saturated vapor pressure at that temperature +0.1 (MPaG) or less. At this time, or when the temperature of the hot pressurized water drops to + 20 ° C. or lower of the saturation temperature at the pressure of the spray site, pressurized air is allowed to flow.
[0011]
According to a fifth aspect of the present invention, in the second or third aspect, the flow rate of the pressurized air in the case of the two-fluid spraying method is set to the flow rate of the pressurized hot water sprayed into the exhaust gas. The control is made proportional.
[0012]
The invention according to claim 6 provides a gas cooling chamber or an exhaust gas duct having a gas inlet and a gas outlet, and pressurized hot water for supplying pressurized hot water having a temperature higher than the boiling point of water under atmospheric pressure. A supply source, a desuperheated water spray nozzle that sprays pressurized hot water from the pressurized hot water supply source into the gas cooling chamber or the exhaust gas duct, and desuperheated water that adjusts the amount of pressurized hot water supplied to the desuperheated water spray nozzle An amount control valve, a temperature detector for one or both of a high-temperature exhaust gas flowing from a gas inlet and a low-temperature exhaust gas flowing out from a gas outlet, and opening / closing control of a desuperheated water amount control valve based on a detection signal from the temperature detector. In an exhaust gas desuperheater using hot water comprising a temperature controller, the desuperheated water spray nozzle is a desuperheated water spray nozzle capable of performing both one-fluid spray and two-fluid spray. A mixer is installed between the control valve and the temperature control valve. Connecting a compressed air supply device to the mixer with a pressurized air control valve interposed therebetween, and further providing a pressure detector and a temperature detector for the pressurized hot water downstream of the deheated water control valve, When the pressure detected by the pressure detector drops to near the saturated vapor pressure at that temperature of the pressurized hot water, or the temperature detected by the temperature detector drops to near the saturation temperature at the spray field pressure. The basic structure of the present invention is that when this is done, the pressurized air control valve is controlled to open and close via a pressurized air control device to spray pressurized hot water into exhaust gas by a two-fluid spray method. It is.
[0013]
The invention according to claim 7 of the present application provides a gas cooling chamber or an exhaust gas duct having a gas inlet and a gas outlet, and a pressurized heat supply for supplying pressurized hot water having a temperature higher than the boiling point of water at atmospheric pressure. A water supply source, a desuperheated water spray nozzle for spraying pressurized hot water from a pressurized hot water supply source into a gas cooling chamber or an exhaust gas duct, and an amount of pressurized hot water supplied to the deheated water spray nozzle are adjusted. A temperature-reducing water amount control valve, one or both of a high-temperature exhaust gas flowing from a gas inlet and a low-temperature exhaust gas flowing out from a gas outlet, and a temperature-reducing water amount control valve according to a detection signal from the temperature detector. A temperature control device for controlling the temperature of the exhaust gas, wherein the temperature-reduced water spray nozzle is a temperature-reduced water spray nozzle capable of performing both one-fluid spray and two-fluid spray. Nozzle connection between nozzle and temperature control valve Is a double-walled conduit, the inner passage of which is a pressurized air flow passage, the outer passage is a passage of pressurized hot water, and a pressurized air control valve is interposed in the inner passage of the nozzle conduit. And a pressure detector and a temperature detector for the pressurized hot water in the outer passage are provided in the nozzle conduit, and the detection pressure of the pressure detector is set at the temperature of the pressurized hot water at the temperature. When the temperature decreases to near the saturated vapor pressure, or when the temperature detected by the temperature detector decreases to near the saturation temperature at the pressure of the spray field, the pressurized air control is performed via the pressurized air control device. The basic configuration of the present invention is to control the opening and closing of a valve and spray pressurized hot water into exhaust gas by a two-fluid spray method.
[0014]
According to an eighth aspect of the present invention, in the sixth or eighth aspect of the invention, the pressure detected by the pressure detector is reduced to not more than a saturated vapor pressure at that temperature of the pressurized hot water + 0.1 (MPaG). The pressurized air control valve is opened when the temperature detected by the temperature detector drops below the saturation temperature at the pressure of the spray field + 20 ° C. or less.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory view of a method for cooling exhaust gas according to a first embodiment of the present invention and an apparatus used for the method. In the figure, 1 is a gas cooling chamber, 1a is an exhaust gas inlet, 1b is an exhaust gas outlet, and 1c is ash. Outlet, 1d is ash feeder, 2 is desuperheated water spray nozzle, 3 is desuperheated water flow control valve, 4 is temperature control device, 4a and 4b are temperature detectors, 5 is pressurized air control valve, 6 is pressurized air Control device, 6a is a pressure detector, 6b is a temperature detector of pressurized hot water, 7 is a nozzle conduit, Gh is high temperature exhaust gas, Gl is low temperature exhaust gas, C is ash, Wt is pressurized hot water, and A is pressurized. It is air.
FIG. 2 is a cross-sectional view of a nozzle conduit 7 connecting between the desuperheated water spray nozzle 2 and the desuperheated water amount control valve 3. The nozzle conduit 7 has a double wall composed of an outer pipe 7a and an inner pipe 7b. This is a conduit having a structure, in which temperature-reduced water (pressurized hot water) Wt flows through the outer passage 7c, and pressurized air A flows through the inner passage 7d.
[0016]
In the present invention, a nozzle capable of performing both one-fluid spraying and two-fluid spraying is used as the temperature-reduced water spraying nozzle 2, and as described later, a combustion device (not shown) is used to generate pressurized heat during steady operation or the like. When the spray amount of the water Wt is large, it is operated as a one-fluid spray nozzle that sprays only the pressurized hot water Wt. Further, when the spray amount of the pressurized hot water Wt is small when the combustion device is started or shut down, or when the temperature of the pressurized hot water Wt decreases, the pressurized air A and the pressurized hot water Wt are used. Is operated as a two-fluid spray nozzle for mixing and spraying.
[0017]
The structure of the desuperheated water spray nozzle 2 may be any structure as long as it can switch between one-fluid spray and two-fluid spray. In the embodiment shown in FIG. A structure in which the compressed air A is mixed into the center of the flow of the pressurized hot water Wt just before the ejection port of the temperature-reduced water spray nozzle 2, and a mixture of both is ejected outward from the ejection port. Nozzles are used.
[0018]
The temperature-reduced water (pressurized hot water) Wt is water (pressurized hot water) having a temperature higher than the boiling point (100 ° C.) under atmospheric pressure, and maintains a pressure higher than the saturated vapor pressure at that temperature. Things. The pressure of the pressurized hot water Wt is usually selected to be in the range of 0.1 to 10 MPaG, and the pressure of the pressurized hot water Wt is reduced in terms of facilities of a hot water supply source (not shown) such as a waste heat boiler and a hot water storage tank. The pressure of Wt is desirably about 0.3 to 1.0 MPaG.
[0019]
A compressor or the like is used as an air source of the pressurized air A, and the pressure is set to a value close to the pressure of the pressurized hot water Wt. Specifically, the pressure of the pressurized air A is set between 0.1 and 10 MPaG, preferably 0.3 to 0.7 MPaG.
[0020]
The configurations of the gas cooling chamber 1, the dewatering water amount control valve 3, the temperature control device 4 and the like in FIG. 1 are substantially the same as those in the case of Japanese Patent Application Laid-Open No. 2000-274654. I do.
Although FIG. 1 describes the temperature reduction of the high-temperature exhaust gas Gh in the gas cooling chamber 1, the present invention can also be applied to the temperature reduction of the high-temperature exhaust gas Gh in an exhaust gas duct (not shown). Of course.
Further, in FIG. 1, ordinary water is used as the pressurized hot water Wt. However, in order to remove an acidic gas in the high-temperature exhaust gas Gh, water containing an alkaline solution or the like is removed by the pressurized hot water Wt. Needless to say, Wt may be used.
[0021]
Next, the temperature reduction of the high-temperature exhaust gas Gh according to the present invention will be described.
Referring to FIGS. 1 and 2, when a combustion device (not shown) or the like is in a steady operation and the amount of deheated water (the amount of pressurized hot water) is relatively large, the pressurized air control valve 5 is closed. Have been. As a result, the pressurized hot water Wt is introduced into the outside passage 7c of the nozzle conduit 7 through the desuperheated water amount control valve 3, and is sprayed from the desuperheated water spray nozzle 2 into the high-temperature exhaust gas Gh by a so-called one-fluid spray method.
[0022]
The spray amount of the pressurized hot water Wt is determined by the detection signals from the temperature detector 4b of the high-temperature exhaust gas Gh and the temperature detector 4a of the low-temperature exhaust gas Gl via the temperature control device 4, The opening degree is controlled automatically so that the temperature of the low-temperature exhaust gas Gl is controlled to a temperature within a set range.
[0023]
Further, the pressure and the temperature of the pressurized hot water Wt flowing in the outside passage 7a of the nozzle conduit 7 are constantly detected by the pressure detector 6a and the temperature detector 6b, and the pressurized air control device is detected by each detection signal. Via 6, the pressurized air control valve 5 is controlled to open and close.
[0024]
Specifically, the pressure value of the pressurized hot water Wt detected by the pressure detector 6a is close to the saturated vapor pressure Ps of the pressurized hot water Wt at that temperature (for example, the saturated vapor pressure Ps ± 1.0). When the pressure reaches (MPaG), desirably the saturated vapor pressure Ps + 0.1 (MPaG) or less, the pressurized air control valve 5 is opened to supply the pressurized air A into the inside passage 7 d of the nozzle conduit 7.
Similarly, if the temperature detection value of the pressurized hot water Wt by the temperature detector 6b becomes a temperature near the saturation temperature of the pressure of the spraying station of the pressurized hot water Wt (for example, a temperature equal to or lower than the saturation temperature + 20 ° C.) The pressurized air control valve 5 is opened to supply the pressurized air A into the inside passage 7d of the nozzle conduit 7.
As a result, the temperature-reduced water spray nozzle 2 operates as a two-fluid spray nozzle, thereby preventing a change in the spray amount and an increase in the spray particle diameter as described later.
[0025]
For example, when a combustion device (not shown) starts up or shuts down, the temperature and the exhaust gas amount of the high-temperature exhaust gas Gh on the inlet side decrease as compared with the exhaust gas temperature and the exhaust gas amount during steady operation. As a result, the spray amount of the pressurized hot water Wt itself required for reducing the temperature of the exhaust gas also becomes smaller than the spray amount during the steady operation.
On the other hand, when the spray amount of the pressurized hot water Wt is reduced by squeezing the dewatering water amount control valve 3, the flow path resistance of the portion of the control valve 3 increases, and the pressure loss in this portion increases. Since the effective cross-sectional area of the outer passage 7c through which the pressurized hot water Wt flows is considerably large, a part of the pressurized hot water Wt whose flow rate is reduced by the throttle evaporates in the outer passage 7c. As a result, the pressure of the pressurized hot water Wt decreases to a pressure close to or lower than the saturated vapor pressure at that temperature.
[0026]
By the way, when the pressure of the pressurized hot water Wt flowing through the outside passage 7c decreases to a pressure near the saturated vapor pressure at that temperature or a pressure lower than the saturated vapor pressure, the degassed water spray nozzle 2 flows into the high-temperature exhaust gas Gh. The spray amount of the pressurized hot water Wt to be ejected pulsates with time, and the spray particle diameter of the atomized pressurized hot water Wt increases, and as a result, the cooling capability of the hot exhaust gas Gh by the spray water decreases. Also, water drops directly hit the wall surface of the gas cooling chamber and flow down, thereby causing damage to the refractory material and adhesion / deposition of dust.
[0027]
Therefore, as described above, when the pressure of the pressurized hot water Wt on the downstream side of the temperature-reducing water amount control valve 3 decreases to near the saturated vapor pressure at that temperature, the pressurized air control valve 5 is opened and the predetermined flow rate is reduced. The pressurized air A is supplied to the inside of the inner passage 7b, and the nozzle 2 is operated as a two-fluid spray nozzle.
That is, inside the main body of the nozzle 2, the pressurized air A is ejected to the center of the pressurized hot water Wt in the same direction as the flow direction of the pressurized hot water Wt. The flow of Wt is made uniform and the particle size of the spray particles from the nozzle 2 is made finer.
[0028]
In the embodiment shown in FIG. 1, the pressure of the pressurized hot water Wt downstream of the temperature-reducing water control valve 3 (the pressure detected by the pressure detector 6a) is equal to the saturated vapor pressure Ps + 0. When the pressure becomes equal to or less than 1 (MPaG), the pressurized air control valve 5 is opened to supply the pressurized air A having a predetermined flow rate of 0.3 to 0.7 MPaG to the desuperheated water spray nozzle 2. I have.
[0029]
Further, in the embodiment of FIG. 1, the pressurized air control valve 5 is opened or closed via the pressurized air control device 6 by the pressure of the pressurized hot water Wt detected by the pressure detector 6a. Although only control for supplying (or stopping supply of) pressurized air A at a pressure and flow rate is performed, by adding a temperature control element to the pressurized air control valve 5 and the pressurized air control device 6, it is possible to increase the pressure. It is also possible to adopt a configuration in which the supply amount of the compressed air A is controlled in association with the flow rate of the pressurized hot water Wt to be sprayed.
[0030]
Further, in the embodiment of FIG. 1, since the pressurized hot water Wt is caused to flow to the outer passage 7c of the nozzle pipe 7 having the double-wall structure, the surface temperature of the nozzle pipe 7 is always the so-called exhaust gas Gh. Is maintained at a temperature higher than the acid dew point of the acidic gas, and as a result, corrosion of the nozzle conduit 7 due to HCl or SOx in the exhaust gas Gh is effectively prevented.
[0031]
In the above description, a case where the pressure of the pressurized hot water Wt is reduced when the deheated water control valve 3 is throttled when the combustion device (not shown) is started or shut down is exemplified. Although described, even when the temperature of the pressurized hot water Wt falls below the saturation temperature of the spraying station of the pressurized hot water Wt at the time of startup or shutdown of the combustion device (not shown), This is exactly the same as the above description.
[0032]
FIG. 3 shows a second embodiment of the present invention. A pressurized air control valve 8 is provided downstream of the pressurized air control valve 5 in FIG. Is controlled in parallel with the temperature-reducing water amount control valve 3 via the temperature control device 4 so that the supply flow rate of the pressurized air A during the two-fluid spraying is proportional to the spray amount of the pressurized hot water Wt. It was done.
[0033]
As described above, by making the supply flow rate of the pressurized air A proportional to the spray amount of the pressurized hot water Wt, even at the time of two-fluid spraying where the spray amount of the pressurized hot water Wt is small, a higher spray amount can be obtained. Control becomes possible, and the consumption of the pressurized air A can be greatly reduced as compared with the conventional two-fluid spraying method.
[0034]
FIG. 4 is an explanatory diagram showing a third embodiment of the present invention.
In the third embodiment, a mixer 9 is provided on the downstream side of the temperature-reducing water amount control valve 3, and after the pressurized hot water Wt and the pressurized air A are mixed by the mixer 9, the two are mixed. A configuration is employed in which a fluid is supplied to the desuperheated water spray nozzle 2 through the piping 10.
[0035]
In the third embodiment as well, the reason why the pressurized air control valve 5 is opened is that the detected pressure value of the pressurized hot water Wt detected by the pressure detector 6a when the combustion device starts up or shuts down. If the temperature of the pressurized hot water Wt drops to near the saturated vapor pressure at that temperature, or the temperature of the pressurized hot water Wt by the temperature detector 6b drops to near the saturation temperature at the pressure of the spraying station. When the spray amount of the pressurized hot water Wt is close to a steady value, the temperature of the high-temperature exhaust gas Gh is reduced by a so-called one-fluid spray method in which only the pressurized hot water Wt is sprayed.
In the third embodiment, the pipe 10 may be a single pipe.
[0036]
【The invention's effect】
In the present invention, the temperature-reduced water spray nozzle is a temperature-reduced water nozzle capable of switching between one-fluid spray and two-fluid spray, and the pressure of the pressurized hot water becomes close to the saturated vapor pressure at that temperature. When the temperature of the pressurized hot water Wt drops to near the saturation temperature at the pressure of the spray field, the pressurized hot water is sprayed by the two-fluid spray by the supply of pressurized air. .
As a result, the required amount of pressurized hot water can always be sprayed into the exhaust gas in a stable state even when the combustion device is started or shut down, and the spray particle size can be prevented from increasing. In addition, it is possible to completely prevent troubles such as damage to the wall refractory material and accumulation of dust due to a decrease in exhaust gas cooling performance and flow of water droplets.
[0037]
In addition, since the nozzle conduit has a double wall structure, acid gas corrosion in a portion that comes into contact with the high-temperature exhaust gas Gh or the like is effectively prevented, which is advantageous.
[0038]
Furthermore, by controlling the supply of pressurized air during the two-fluid spraying to control the amount of pressurized air to be proportional to the amount of pressurized hot water spray, more precise control of the spray amount of pressurized hot water can be performed. The consumption of compressed air can be reduced.
[0039]
In addition, in the present invention, only when the spray amount of pressurized hot water decreases or when the temperature of pressurized hot water decreases, such as when starting or shutting down the combustion device, the high-temperature exhaust gas is discharged by the two-fluid spray method. , It is possible to significantly reduce the consumption of high-pressure air as compared with the conventional exhaust gas temperature reduction method using the two-fluid spray method.
The present invention has excellent practical utility as described above.
[Brief description of the drawings]
FIG. 1 illustrates a first embodiment of the present invention, and is an explanatory diagram in a case where the present invention is applied to an exhaust gas cooling chamber.
FIG. 2 is a schematic cross-sectional view of a nozzle conduit used in the present invention.
FIG. 3 illustrates a second embodiment of the present invention, and is an explanatory diagram in a case where the present invention is applied to an exhaust gas cooling chamber.
FIG. 4 illustrates a third embodiment of the present invention, and is an explanatory diagram in a case where the present invention is applied to an exhaust gas cooling chamber.
FIG. 5 is an explanatory diagram of a conventional exhaust gas temperature reducing method using hot water.
[Explanation of symbols]
Gh is high-temperature exhaust gas, Gl is low-temperature exhaust gas, Wt is pressurized hot water, A is pressurized air, C is ash, 1 is a gas cooling chamber, 1a is an exhaust gas inlet, 1b is an exhaust gas outlet, 1c is an ash outlet, and 1d is Ashing feeder, 2 is a reduced temperature water spray nozzle, 3 is a reduced temperature water control valve, 4 is a temperature control device, 4a and 4b are temperature detectors, 5 is a pressurized air control valve, 6 is a pressurized air control device, 6a Is a pressure detector, 6b is a temperature detector, 7 is a nozzle conduit, 7a is an outer tube, 7b is an inner tube, 7c is an outer passage, 7d is an inner passage, 8 is a pressurized air amount control valve, 9 is a mixer, 10 is a pipeline.

Claims

In an incinerator or a boiler facility that uses hot water in an incinerator or a boiler facility, the hot water pressurized at a temperature higher than the boiling point of water at atmospheric pressure is sprayed as desuperheated water. The temperature-reduced water spray nozzle that sprays water into the exhaust gas as temperature-reduced water is a temperature-reduced water spray nozzle that can perform both two-fluid spray and single-fluid spray. When the pressure of the pressurized hot water downstream of the valve drops to near the saturated vapor pressure at that temperature, or when the temperature of the pressurized hot water becomes close to the saturated temperature at the spray field pressure. When the temperature of the exhaust gas is lowered, pressurized air is circulated to the deheated water spray nozzle, and pressurized hot water is sprayed into the exhaust gas by a two-fluid spray method. .

In an incinerator or a boiler facility that uses hot water in an incinerator or a boiler facility, the hot water pressurized at a temperature higher than the boiling point of water at atmospheric pressure is sprayed as desuperheated water. The temperature-reduced water spray nozzle that sprays water into the exhaust gas as temperature-reduced water is a temperature-reduced water spray nozzle that can perform both two-fluid spray and single-fluid spray, and a double-walled nozzle conduit with a reduced-temperature water spray nozzle attached to the tip. When the pressurized hot water flows through the outer passage of the double-walled nozzle conduit when the pressure of the pressurized hot water decreases to near the saturated vapor pressure at that temperature, Alternatively, when the temperature of the pressurized hot water has dropped to near the saturation temperature at the pressure of the spraying field, pressurized air is circulated through the inner passage of the nozzle conduit, and pressurized heat is discharged into the exhaust gas by a two-fluid spray method. Spraying water Exhaust gas decreased temperature method using hot water, characterized.

The exhaust gas temperature reducing method using hot water according to claim 1 or 2, wherein the pressurized hot water is sprayed into the gas cooling chamber or the exhaust gas duct as temperature reducing water.

When the pressure of the pressurized hot water in the nozzle conduit falls below the saturated vapor pressure at that temperature +0.1 (MPaG) or when the temperature of the pressurized hot water becomes the saturated temperature at the pressure of the spraying field +20 The method for reducing exhaust gas temperature using hot water according to claim 2 or 3, wherein the pressurized air is allowed to flow when the temperature falls to or below ° C.

The exhaust gas cooling method according to claim 2 or 3, wherein the flow rate of the pressurized air in the two-fluid spray method is controlled to be proportional to the flow rate of the pressurized hot water sprayed into the exhaust gas.

A gas cooling chamber or an exhaust gas duct having a gas inlet and a gas outlet, a supply source of pressurized hot water for supplying pressurized hot water having a temperature higher than the boiling point of water under atmospheric pressure, A desuperheated water spray nozzle that sprays pressurized hot water from the supply source into the gas cooling chamber or exhaust gas duct, a deheated water flow control valve that adjusts the amount of pressurized hot water supplied to the deheated water spray nozzle, and flows in from the gas inlet Hot water comprising a high-temperature exhaust gas and / or a low-temperature exhaust gas flowing out of a gas outlet, and hot water comprising a temperature control device that controls the opening and closing of a dewatering water amount control valve by a detection signal from the temperature detector. In the exhaust gas temperature reduction device used, the temperature-reduced water spray nozzle is a temperature-reduced water spray nozzle capable of performing both one-fluid spray and two-fluid spray. Provision of a mixer and pressurized air A compressed air supply device is connected via a control valve, and a pressure detector and a temperature detector for pressurized hot water are further provided downstream of the dewatering water amount control valve. When the pressure of the pressurized hot water drops to near the saturated vapor pressure at that temperature, or when the temperature detected by the temperature detector drops to near the saturation temperature at the pressure of the spraying field of the pressurized hot water, The exhaust gas temperature reduction using hot water, characterized in that the pressurized air control valve is controlled to open and close via a pressurized air control device, and pressurized hot water is sprayed into the exhaust gas by a two-fluid spray method. apparatus.

A gas cooling chamber or an exhaust gas duct having a gas inlet and a gas outlet, a supply source of pressurized hot water for supplying pressurized hot water having a temperature higher than the boiling point of water under atmospheric pressure, A desuperheated water spray nozzle that sprays pressurized hot water from the supply source into the gas cooling chamber or exhaust gas duct, a deheated water flow control valve that adjusts the amount of pressurized hot water supplied to the deheated water spray nozzle, and flows in from the gas inlet Hot water comprising a high-temperature exhaust gas and / or a low-temperature exhaust gas flowing out of a gas outlet, and hot water comprising a temperature control device that controls the opening and closing of a dewatering water amount control valve by a detection signal from the temperature detector. In the exhaust gas temperature reducing apparatus used, the temperature reducing water spray nozzle is a temperature reducing water spray nozzle capable of performing both one-fluid spraying and two-fluid spraying, and a nozzle conduit between the temperature reducing water spray nozzle and the temperature reducing water amount control valve As a double-walled conduit The side passage is a flow passage for compressed air, the outside passage is a passage for pressurized hot water, and a compressed air supply device is connected to the inside passage of the nozzle conduit via a pressurized air control valve. Providing a pressure detector and a temperature detector for the pressurized hot water in the outer passage in the nozzle conduit, wherein the detected pressure of the pressure detector has dropped to near the saturated vapor pressure at that temperature of the pressurized hot water. When, or when the temperature detected by the temperature detector drops to near the saturation temperature of the pressurized hot water at the pressure of the spray field, the pressurized air control valve is controlled to open and close via a pressurized air control device. An exhaust gas temperature reducing apparatus using hot water, wherein pressurized hot water is sprayed into exhaust gas by a two-fluid spray method.

When the pressure detected by the pressure detector falls to or below the saturated vapor pressure of the pressurized hot water +0.1 (MPaG) at that temperature, or when the temperature detected by the temperature detector becomes the saturation temperature at the pressure of the spray field. The exhaust gas temperature reducing apparatus using hot water according to claim 6 or 7, wherein the pressurized air control valve is opened when the temperature falls to + 20 ° C or lower.