JP3575500B2

JP3575500B2 - Gas flow control device for desulfurizer

Info

Publication number: JP3575500B2
Application number: JP13663195A
Authority: JP
Inventors: 訓木村
Original assignee: 石川島播磨重工業株式会社
Priority date: 1995-06-02
Filing date: 1995-06-02
Publication date: 2004-10-13
Anticipated expiration: 2019-10-13
Also published as: JPH08323140A

Description

【０００１】
【産業上の利用分野】
本発明は、脱硫装置のガス流量制御装置に関するものである。
【０００２】
【従来の技術】
一般に、石炭等の硫黄分を含む燃料が使用され、硫黄分を含む排ガスが排出されるボイラ設備においては、排ガスから硫黄分を除去するための脱硫装置が設けられる。
【０００３】
図３は斯かる従来の脱硫装置のガス流量制御装置の一例を表わすものであって、１は硫黄分を含む排ガスが排出されるボイラ本体、２はボイラ本体１から排出される排ガスを煙突１０へ導く排ガスライン、３は排ガスライン２途中に設けられ且つボイラ本体１から排出される排ガスを誘引する誘引通風機、４は誘引通風機３によって誘引される排ガスの流量を調整するための誘引通風機ガス流量制御ダンパ、５は前記誘引通風機３の下流側の排ガスライン２途中に配設され且つ前記排ガスから硫黄分を除去するための脱硫装置、６は脱硫装置５の下流側の排ガスライン２途中に設けられた脱硫通風機、７は脱硫通風機６によって誘引され且つ脱硫装置５を通過する脱硫ガスの流量を調整するための脱硫通風機ガス流量制御ダンパ、８は前記誘引通風機３と脱硫装置５との間の排ガスライン２途中から分岐し且つ前記脱硫通風機６の下流側の排ガスライン２途中に接続される脱硫バイパスライン、９は脱硫バイパスライン８途中に設けられた脱硫バイパスダンパである。
【０００４】
前記誘引通風機ガス流量制御ダンパ４は、ボイラ炉内圧制御指令に応じて出力される誘引通風機ガス流量制御ダンパ開度指令１１に基づいて開度調整されるようになっている。
【０００５】
又、図３中、１２は脱硫バイパスダンパの上流側と下流側の差圧１３を検出する脱硫バイパスダンパ差圧検出器、１４は誘引通風機ガス流量制御ダンパ開度指令１１に基づき脱硫通風機ガス流量制御ダンパ基本開度指令１５を出力する関数発生器、１６は前記脱硫バイパスダンパ差圧検出器１２で検出した差圧１３と脱硫バイパスダンパ差圧目標値１７との差を求め、差圧偏差信号１８を出力する減算器、１９は減算器１６から出力される差圧偏差信号１８を比例積分処理し、該差圧偏差信号１８を０とするための脱硫通風機ガス流量制御ダンパ開度補正指令２０を出力する比例積分調節器、２１は前記脱硫バイパスダンパ９閉時には前記比例積分調節器１９からの脱硫通風機ガス流量制御ダンパ開度補正指令２０を信号２２として出力する一方、前記脱硫バイパスダンパ９開時には無条件に０の信号２３を信号２２として出力する切換リレー、２４は前記関数発生器１４から出力される脱硫通風機ガス流量制御ダンパ基本開度指令１５と前記切換リレー２１から出力される信号２２との和を求め、脱硫通風機ガス流量制御ダンパ７へ開度指令２５を出力する加算器であり、前記脱硫通風機ガス流量制御ダンパ７は、加算器２４から出力される開度指令２５に基づいて開度調整されるようになっている。
【０００６】
尚、前記関数発生器１４には、図４に示されるような関数が入力されており、該関数は、誘引通風機ガス流量制御ダンパ開度指令１１の増減に対し略比例させて脱硫通風機ガス流量制御ダンパ基本開度指令１５を増減させることを表わしている。
【０００７】
前述の如き脱硫装置のガス流量制御装置においては、脱硫装置５に故障等がなく、脱硫バイパスダンパ９が閉じた状態での通常の運転時には、ボイラ炉内圧制御指令に応じて出力される誘引通風機ガス流量制御ダンパ開度指令１１に基づいて誘引通風機ガス流量制御ダンパ４が開度調整されると共に、前記誘引通風機ガス流量制御ダンパ開度指令１１が関数発生器１４へ入力され、該関数発生器１４において誘引通風機ガス流量制御ダンパ開度指令１１に基づき脱硫通風機ガス流量制御ダンパ基本開度指令１５が加算器２４へ出力され、脱硫バイパスダンパ差圧検出器１２によって脱硫バイパスダンパ９の上流側と下流側の差圧１３が検出され、減算器１６において差圧１３と脱硫バイパスダンパ差圧目標値１７との差が求められて差圧偏差信号１８が比例積分調節器１９へ出力され、該比例積分調節器１９において差圧偏差信号１８が比例積分処理されて該差圧偏差信号１８を０とするための脱硫通風機ガス流量制御ダンパ開度補正指令２０が切換リレー２１へ出力され、該切換リレー２１から脱硫通風機ガス流量制御ダンパ開度補正指令２０が信号２２として加算器２４へ出力され、該加算器２４において前記関数発生器１４から出力される脱硫通風機ガス流量制御ダンパ基本開度指令１５と前記切換リレー２１から出力される信号２２との和が求められて脱硫通風機ガス流量制御ダンパ７へ開度指令２５が出力され、脱硫通風機ガス流量制御ダンパ７が開度調整され、これにより、脱硫バイパスライン８における脱硫バイパスダンパ９の下流側圧力が上流側圧力よりも若干高くなるように制御が行われ、脱硫前の未処理の排ガスが脱硫バイパスライン８の脱硫バイパスダンパ９を経て外部へ漏洩しないようになっている。
【０００８】
一方、万が一、脱硫装置５の図示していないガスガスヒータやミストエリミネータ等が故障したような場合には、ボイラ本体１の運転は停止されるが、急には止らないため、ボイラ本体１の運転が停止するまでの間、ボイラ本体１の火炉圧が異常に高まることを防止するために、脱硫バイパスダンパ９が開かれ、該脱硫バイパスダンパ９が開かれると、切換リレー２１から無条件に０の信号２３が信号２２として加算器２４へ出力され、脱硫通風機ガス流量制御ダンパ７の開度は、誘引通風機ガス流量制御ダンパ開度指令１１に基づいて関数発生器１４から出力される脱硫通風機ガス流量制御ダンパ基本開度指令１５によって制御される形となる。
【０００９】
【発明が解決しようとする課題】
しかしながら、前述の如き脱硫装置のガス流量制御装置では、脱硫装置５の図示していないガスガスヒータやミストエリミネータ等の故障時に脱硫バイパスダンパ９が開かれた場合、ボイラ本体１の運転が停止するまでの間、硫黄分を含む排ガスが未処理のまま脱硫バイパスライン８を経由して煙突１０から大気へ放出される可能性があった。
【００１０】
本発明は、斯かる実情に鑑み、脱硫装置のガスガスヒータやミストエリミネータ等の故障時に脱硫バイパスダンパが開かれた場合にも、硫黄分を含む排ガスが未処理のまま脱硫バイパスラインを経由して煙突から大気へ放出されることを防止し得る脱硫装置のガス流量制御装置を提供しようとするものである。
【００１１】
【課題を解決するための手段】
本発明は、ボイラ本体１から排出される硫黄分を含む排ガスを煙突１０へ導く排ガスライン２と、該排ガスライン２途中に設けられ且つボイラ本体１から排出される排ガスを誘引する誘引通風機３と、該誘引通風機３によって誘引される排ガスの流量を調整するための誘引通風機ガス流量制御ダンパ４と、前記誘引通風機３の下流側の排ガスライン２途中に配設され且つ前記排ガスから硫黄分を除去するための脱硫装置５と、該脱硫装置５の下流側の排ガスライン２途中に設けられた脱硫通風機６と、該脱硫通風機６によって誘引され且つ脱硫装置５を通過する脱硫ガスの流量を調整するための脱硫通風機ガス流量制御ダンパ７と、前記誘引通風機３と脱硫装置５との間の排ガスライン２途中から分岐し且つ前記脱硫通風機６の下流側の排ガスライン２途中に接続される脱硫バイパスライン８と、該脱硫バイパスライン８途中に設けられた脱硫バイパスダンパ９とを備えた脱硫装置のガス流量制御装置であって、
ボイラ本体１から排出される排ガス流量２６を検出する排ガス流量検出器２７と、
脱硫装置５を通過した脱硫ガス流量２８を検出する脱硫ガス流量検出器２９と、
脱硫バイパスダンパ９の上流側と下流側の差圧１３を検出する脱硫バイパスダンパ差圧検出器１２と、
誘引通風機ガス流量制御ダンパ開度指令１１に基づき脱硫通風機ガス流量制御ダンパ基本開度指令１５を出力する関数発生器１４と、
前記脱硫バイパスダンパ差圧検出器１２で検出した差圧１３と脱硫バイパスダンパ差圧目標値１７との差を求め、差圧偏差信号１８を出力する減算器１６と、
該減算器１６から出力される差圧偏差信号１８を比例積分処理し、該差圧偏差信号１８を０とするための脱硫通風機ガス流量制御ダンパ開度補正指令２０を出力する比例積分調節器１９と、
前記排ガス流量検出器２７で検出した排ガス流量２６に基づき脱硫ガス流量目標値３０を出力する関数発生器３１と、
前記脱硫ガス流量検出器２９で検出した脱硫ガス流量２８と前記関数発生器３１から出力される脱硫ガス流量目標値３０との差を求め、脱硫ガス流量偏差信号３２を出力する減算器３３と、
該減算器３３から出力される脱硫ガス流量偏差信号３２を比例積分処理し、該脱硫ガス流量偏差信号３２を０とするための脱硫通風機ガス流量制御ダンパ開度補正指令３４を出力する比例積分調節器３５と、
前記脱硫バイパスダンパ９閉時には前記差圧偏差信号１８を比例積分処理する比例積分調節器１９からの脱硫通風機ガス流量制御ダンパ開度補正指令２０を信号２２として出力する一方、前記脱硫バイパスダンパ９開時には前記脱硫ガス流量偏差信号３２を比例積分処理する比例積分調節器３５からの脱硫通風機ガス流量制御ダンパ開度補正指令３４を信号２２として出力する切換リレー２１と、
前記関数発生器１４から出力される脱硫通風機ガス流量制御ダンパ基本開度指令１５と前記切換リレー２１から出力される信号２２との和を求め、脱硫通風機ガス流量制御ダンパ７へ開度指令２５を出力する加算器２４と
を備えたことを特徴とするものである。
【００１２】
【作用】
従って、脱硫装置５に故障等がなく、脱硫バイパスダンパ９が閉じた状態での通常の運転時には、ボイラ炉内圧制御指令に応じて出力される誘引通風機ガス流量制御ダンパ開度指令１１に基づいて誘引通風機ガス流量制御ダンパ４が開度調整されると共に、前記誘引通風機ガス流量制御ダンパ開度指令１１が関数発生器１４へ入力され、該関数発生器１４において誘引通風機ガス流量制御ダンパ開度指令１１に基づき脱硫通風機ガス流量制御ダンパ基本開度指令１５が加算器２４へ出力され、脱硫バイパスダンパ差圧検出器１２によって脱硫バイパスダンパ９の上流側と下流側の差圧１３が検出され、減算器１６において差圧１３と脱硫バイパスダンパ差圧目標値１７との差が求められて差圧偏差信号１８が比例積分調節器１９へ出力され、該比例積分調節器１９において差圧偏差信号１８が比例積分処理されて該差圧偏差信号１８を０とするための脱硫通風機ガス流量制御ダンパ開度補正指令２０が切換リレー２１へ出力され、該切換リレー２１から脱硫通風機ガス流量制御ダンパ開度補正指令２０が信号２２として加算器２４へ出力され、該加算器２４において前記関数発生器１４から出力される脱硫通風機ガス流量制御ダンパ基本開度指令１５と前記切換リレー２１から出力される信号２２との和が求められて脱硫通風機ガス流量制御ダンパ７へ開度指令２５が出力され、脱硫通風機ガス流量制御ダンパ７が開度調整され、これにより、脱硫バイパスライン８における脱硫バイパスダンパ９の下流側圧力が上流側圧力よりも若干高くなるように制御が行われ、脱硫前の未処理の排ガスが脱硫バイパスライン８の脱硫バイパスダンパ９を経て外部へ漏洩することが防止される。
【００１３】
一方、万が一、脱硫装置５のガスガスヒータやミストエリミネータ等が故障したような場合に、脱硫バイパスダンパ９が開かれると、排ガス流量検出器２７で検出された排ガス流量２６に基づき関数発生器３１から脱硫ガス流量目標値３０が減算器３３へ出力され、該減算器３３において、脱硫ガス流量検出器２９で検出された脱硫ガス流量２８と前記関数発生器３１から出力される脱硫ガス流量目標値３０との差が求められて脱硫ガス流量偏差信号３２が比例積分調節器３５へ出力され、該比例積分調節器３５において減算器３３から出力される脱硫ガス流量偏差信号３２が比例積分処理されて該脱硫ガス流量偏差信号３２を０とするための脱硫通風機ガス流量制御ダンパ開度補正指令３４が切換リレー２１へ出力され、該切換リレー２１から脱硫通風機ガス流量制御ダンパ開度補正指令３４が信号２２として加算器２４へ出力され、該加算器２４において前記関数発生器１４から出力される脱硫通風機ガス流量制御ダンパ基本開度指令１５と前記切換リレー２１から出力される信号２２との和が求められて脱硫通風機ガス流量制御ダンパ７へ開度指令２５が出力され、脱硫通風機ガス流量制御ダンパ７が開度調整され、これにより、脱硫ガス流量２８が脱硫ガス流量目標値３０となるように制御が行われる。
【００１４】
ここで、脱硫ガス流量目標値３０を排ガス流量２６より所要量αだけ多い値に設定しておけば、脱硫バイパスライン８の下流側から上流側へ向け所要量αの脱硫後の排ガスが流れて脱硫装置５の上流側の排ガスライン２へ戻される形となり、この結果、脱硫前の未処理の排ガスが脱硫バイパスライン８の脱硫バイパスダンパ９を経て煙突１０から大気へ放出されることがなくなる。
【００１５】
【実施例】
以下、本発明の実施例を図面を参照しつつ説明する。
【００１６】
図１は本発明の一実施例であって、図中、図３と同一の符号を付した部分は同一物を表わしており、誘引通風機ガス流量制御ダンパ４の上流側の排ガスライン２に、ボイラ本体１から排出される排ガス流量２６を検出する排ガス流量検出器２７を設けると共に、脱硫通風機ガス流量制御ダンパ７の上流側の排ガスライン２に、脱硫装置５を通過した脱硫ガス流量２８を検出する脱硫ガス流量検出器２９を設け、更に、前記排ガス流量検出器２７で検出した排ガス流量２６に基づき脱硫ガス流量目標値３０を出力する関数発生器３１と、前記脱硫ガス流量検出器２９で検出した脱硫ガス流量２８と前記関数発生器３１から出力される脱硫ガス流量目標値３０との差を求め、脱硫ガス流量偏差信号３２を出力する減算器３３と、該減算器３３から出力される脱硫ガス流量偏差信号３２を比例積分処理し、該脱硫ガス流量偏差信号３２を０とするための脱硫通風機ガス流量制御ダンパ開度補正指令３４を切換リレー２１へ出力する比例積分調節器３５とを追加装備せしめ、脱硫バイパスダンパ９閉時には比例積分調節器１９からの脱硫通風機ガス流量制御ダンパ開度補正指令２０を切換リレー２１から信号２２として出力する一方、前記脱硫バイパスダンパ９開時には前記比例積分調節器３５からの脱硫通風機ガス流量制御ダンパ開度補正指令３４を切換リレー２１から信号２２として出力するよう構成する。
【００１７】
尚、前記関数発生器３１には、図２に示されるような関数が入力されており、該関数は、排ガス流量２６に対し脱硫ガス流量目標値３０を常に所要量αだけ多く設定することを表わしている。
【００１８】
次に、上記実施例の作動を説明する。
【００１９】
脱硫装置５に故障等がなく、脱硫バイパスダンパ９が閉じた状態での通常の運転時には、図３に示される従来例の場合と同様、ボイラ炉内圧制御指令に応じて出力される誘引通風機ガス流量制御ダンパ開度指令１１に基づいて誘引通風機ガス流量制御ダンパ４が開度調整されると共に、前記誘引通風機ガス流量制御ダンパ開度指令１１が関数発生器１４へ入力され、該関数発生器１４において誘引通風機ガス流量制御ダンパ開度指令１１に基づき脱硫通風機ガス流量制御ダンパ基本開度指令１５が加算器２４へ出力され、脱硫バイパスダンパ差圧検出器１２によって脱硫バイパスダンパ９の上流側と下流側の差圧１３が検出され、減算器１６において差圧１３と脱硫バイパスダンパ差圧目標値１７との差が求められて差圧偏差信号１８が比例積分調節器１９へ出力され、該比例積分調節器１９において差圧偏差信号１８が比例積分処理されて該差圧偏差信号１８を０とするための脱硫通風機ガス流量制御ダンパ開度補正指令２０が切換リレー２１へ出力され、該切換リレー２１から脱硫通風機ガス流量制御ダンパ開度補正指令２０が信号２２として加算器２４へ出力され、該加算器２４において前記関数発生器１４から出力される脱硫通風機ガス流量制御ダンパ基本開度指令１５と前記切換リレー２１から出力される信号２２との和が求められて脱硫通風機ガス流量制御ダンパ７へ開度指令２５が出力され、脱硫通風機ガス流量制御ダンパ７が開度調整され、これにより、脱硫バイパスライン８における脱硫バイパスダンパ９の下流側圧力が上流側圧力よりも若干高くなるように制御が行われ、脱硫前の未処理の排ガスが脱硫バイパスライン８の脱硫バイパスダンパ９を経て外部へ漏洩することが防止される。
【００２０】
一方、万が一、脱硫装置５の図示していないガスガスヒータやミストエリミネータ等が故障したような場合に、脱硫バイパスダンパ９が開かれると、排ガス流量検出器２７で検出された排ガス流量２６に基づき関数発生器３１から脱硫ガス流量目標値３０が減算器３３へ出力され、該減算器３３において、脱硫ガス流量検出器２９で検出された脱硫ガス流量２８と前記関数発生器３１から出力される脱硫ガス流量目標値３０との差が求められて脱硫ガス流量偏差信号３２が比例積分調節器３５へ出力され、該比例積分調節器３５において減算器３３から出力される脱硫ガス流量偏差信号３２が比例積分処理されて該脱硫ガス流量偏差信号３２を０とするための脱硫通風機ガス流量制御ダンパ開度補正指令３４が切換リレー２１へ出力され、該切換リレー２１から脱硫通風機ガス流量制御ダンパ開度補正指令３４が信号２２として加算器２４へ出力され、該加算器２４において前記関数発生器１４から出力される脱硫通風機ガス流量制御ダンパ基本開度指令１５と前記切換リレー２１から出力される信号２２との和が求められて脱硫通風機ガス流量制御ダンパ７へ開度指令２５が出力され、脱硫通風機ガス流量制御ダンパ７が開度調整され、これにより、脱硫ガス流量２８が脱硫ガス流量目標値３０となるように、即ち排ガス流量２６に対し脱硫ガス流量２８が常に所要量αだけ多くなるように制御が行われる。
【００２１】
ここで、排ガス流量２６に対し脱硫ガス流量２８が常に所要量αだけ多くなるということは、脱硫バイパスライン８の下流側から上流側へ向け所要量αの脱硫後の排ガスが流れて脱硫装置５の上流側の排ガスライン２へ戻されることとなり、この結果、脱硫前の未処理の排ガスが脱硫バイパスライン８の脱硫バイパスダンパ９を経て煙突１０から大気へ放出されることがなくなる。
【００２２】
こうして、脱硫装置５の図示していないガスガスヒータやミストエリミネータ等の故障時に脱硫バイパスダンパ９が開かれた場合にも、硫黄分を含む排ガスが未処理のまま脱硫バイパスライン８を経由して煙突１０から大気へ放出されることを防止し得る。
【００２３】
尚、本発明の脱硫装置のガス流量制御装置は、上述の実施例にのみ限定されるものではなく、本発明の要旨を逸脱しない範囲内において種々変更を加え得ることは勿論である。
【００２４】
【発明の効果】
以上、説明したように本発明の脱硫装置のガス流量制御装置によれば、脱硫装置のガスガスヒータやミストエリミネータ等の故障時に脱硫バイパスダンパ９が開かれた場合にも、硫黄分を含む排ガスが未処理のまま脱硫バイパスライン８を経由して煙突１０から大気へ放出されることを防止し得るという優れた効果を奏し得る。
【図面の簡単な説明】
【図１】本発明の一実施例の概要構成図である。
【図２】図１に示される関数発生器３１に設定されている関数を表わす線図である。
【図３】従来例の概要構成図である。
【図４】図１及び図３に示される関数発生器１４に設定されている関数を表わす線図である。
【符号の説明】
１ボイラ本体
２排ガスライン
３誘引通風機
４誘引通風機ガス流量制御ダンパ
５脱硫装置
６脱硫通風機
７脱硫通風機ガス流量制御ダンパ
８脱硫バイパスライン
９脱硫バイパスダンパ
１０煙突
１１誘引通風機ガス流量制御ダンパ開度指令
１２脱硫バイパスダンパ差圧検出器
１３差圧
１４関数発生器
１５脱硫通風機ガス流量制御ダンパ基本開度指令
１６減算器
１７脱硫バイパスダンパ差圧目標値
１８差圧偏差信号
１９比例積分調節器
２０脱硫通風機ガス流量制御ダンパ開度補正指令
２１切換リレー
２２信号
２４加算器
２５開度指令
２６排ガス流量
２７排ガス流量検出器
２８脱硫ガス流量
２９脱硫ガス流量検出器
３０脱硫ガス流量目標値
３１関数発生器
３２脱硫ガス流量偏差信号
３３減算器
３４脱硫通風機ガス流量制御ダンパ開度補正指令
３５比例積分調節器[0001]
[Industrial applications]
The present invention relates to a gas flow control device for a desulfurization device.
[0002]
[Prior art]
Generally, in a boiler facility that uses a fuel containing sulfur, such as coal, and discharges exhaust gas containing sulfur, a desulfurization device for removing sulfur from the exhaust gas is provided.
[0003]
FIG. 3 shows an example of such a conventional gas flow control device for a desulfurization apparatus, in which 1 is a boiler main body from which exhaust gas containing sulfur is discharged, and 2 is a chimney 10 for discharging exhaust gas discharged from the boiler main body 1. Exhaust gas line 3 is provided in the middle of the exhaust gas line 2, and an induction ventilator for inducing exhaust gas discharged from the boiler main body 1, and 4 is an induced draft for adjusting a flow rate of the exhaust gas induced by the induction ventilator 3. A machine gas flow control damper 5 is disposed in the exhaust gas line 2 downstream of the induction ventilator 3, and a desulfurization device for removing sulfur from the exhaust gas. 6 is an exhaust gas line downstream of the desulfurization device 5. 2 A desulfurization ventilator provided in the middle, 7 is a desulfurization ventilator gas flow control damper for adjusting the flow rate of desulfurization gas which is attracted by the desulfurization ventilator 6 and passes through the desulfurization device 5, and 8 is the induction A desulfurization bypass line 9 diverging from the middle of the exhaust gas line 2 between the ventilator 3 and the desulfurization device 5 and connected to the middle of the exhaust gas line 2 downstream of the desulfurization ventilator 6 is provided in the middle of the desulfurization bypass line 8. Desulfurization bypass damper.
[0004]
The opening of the induction ventilator gas flow control damper 4 is adjusted based on the induction ventilator gas flow control damper opening command 11 output in response to the boiler furnace internal pressure control command.
[0005]
In FIG. 3, reference numeral 12 denotes a desulfurization bypass damper differential pressure detector for detecting a differential pressure 13 between the upstream side and the downstream side of the desulfurization bypass damper, and reference numeral 14 denotes a desulfurization ventilator based on an induction ventilator gas flow control damper opening degree command 11. A function generator 16 for outputting a gas flow rate control damper basic opening command 15 is used to calculate a difference between the differential pressure 13 detected by the desulfurization bypass damper differential pressure detector 12 and a desulfurization bypass damper differential pressure target value 17. A subtractor 19 for outputting a deviation signal 18 performs proportional integration processing of the differential pressure deviation signal 18 output from the subtractor 16, and a desulfurization ventilator gas flow rate control damper opening degree for setting the differential pressure deviation signal 18 to 0. A proportional integral controller 21 for outputting a correction command 20 outputs a desulfurization ventilator gas flow rate control damper opening correction command 20 from the proportional integral controller 19 as a signal 22 when the desulfurization bypass damper 9 is closed. On the other hand, when the desulfurization bypass damper 9 is opened, a switching relay that unconditionally outputs a signal 23 of 0 as a signal 22, a desulfurization ventilator gas flow control damper basic opening degree command 15 output from the function generator 14 and the This is an adder that obtains the sum of the signal 22 output from the switching relay 21 and outputs an opening command 25 to the desulfurization ventilator gas flow control damper 7. The desulfurization ventilator gas flow control damper 7 includes an adder 24. The opening degree is adjusted based on the opening degree command 25 output from.
[0006]
A function as shown in FIG. 4 is input to the function generator 14, and the function is substantially proportional to the increase and decrease of the induction ventilator gas flow rate control damper opening command 11, and the desulfurization ventilator This indicates that the gas flow control damper basic opening command 15 is increased or decreased.
[0007]
In the gas flow control device of the desulfurization device as described above, during normal operation in a state where the desulfurization device 5 has no failure and the desulfurization bypass damper 9 is closed, the induced draft output in response to the boiler furnace internal pressure control command. The opening degree of the induction ventilator gas flow control damper 4 is adjusted based on the machine gas flow rate control damper opening degree command 11, and the induction ventilation gas flow rate control damper opening degree command 11 is input to the function generator 14, In the function generator 14, the desulfurization ventilator gas flow control damper basic opening command 15 is output to the adder 24 based on the induced ventilator gas flow control damper opening command 11, and the desulfurization bypass damper differential pressure detector 12 detects the desulfurization bypass damper. 9, a difference between the differential pressure 13 and the desulfurization bypass damper differential pressure target value 17 is calculated by a subtractor 16, and the differential pressure deviation is calculated. No. 18 is output to a proportional-integral controller 19, and the differential pressure deviation signal 18 is proportionally integrated in the proportional-integral controller 19 to open the desulfurization ventilator gas flow control damper for setting the differential pressure deviation signal 18 to 0. The correction command 20 is output to the switching relay 21, and the desulfurization ventilator gas flow rate control damper opening correction command 20 is output from the switching relay 21 to the adder 24 as a signal 22. The sum of the desulfurization ventilator gas flow control damper basic opening command 15 output from the controller and the signal 22 output from the switching relay 21 is obtained, and the opening command 25 is output to the desulfurization ventilator gas flow control damper 7. The opening degree of the desulfurization ventilator gas flow control damper 7 is adjusted so that the downstream pressure of the desulfurization bypass damper 9 in the desulfurization bypass line 8 is slightly higher than the upstream pressure. Control is performed so that the exhaust gas of the untreated before desulfurization is prevented from leaking to the outside through the desulfurization bypass damper 9 desulfurization bypass line 8.
[0008]
On the other hand, in the unlikely event that a gas gas heater, mist eliminator, or the like (not shown) of the desulfurization device 5 breaks down, the operation of the boiler main body 1 is stopped. Until the desulfurization bypass damper 9 is opened in order to prevent the furnace pressure of the boiler body 1 from abnormally increasing until the desulfurization bypass damper 9 is opened, the switching relay 21 unconditionally outputs 0. Is output to the adder 24 as a signal 22, and the opening of the desulfurization ventilator gas flow control damper 7 is determined by the desulfurization output from the function generator 14 based on the induction ventilator gas flow control damper opening command 11. The ventilator gas flow rate control is controlled by the damper basic opening command 15.
[0009]
[Problems to be solved by the invention]
However, in the gas flow control device of the desulfurization device as described above, if the desulfurization bypass damper 9 is opened when a gas gas heater or a mist eliminator (not shown) of the desulfurization device 5 fails, the operation of the boiler main body 1 is stopped. During this time, there is a possibility that the exhaust gas containing sulfur is discharged to the atmosphere from the chimney 10 via the desulfurization bypass line 8 without treatment.
[0010]
The present invention has been made in view of such circumstances, and even when a desulfurization bypass damper is opened at the time of failure of a gas gas heater, a mist eliminator, or the like of a desulfurization device, an exhaust gas containing sulfur remains untreated via a desulfurization bypass line. An object of the present invention is to provide a gas flow control device of a desulfurization device that can prevent the gas from being released from the chimney to the atmosphere.
[0011]
[Means for Solving the Problems]
The present invention provides an exhaust gas line 2 for guiding exhaust gas containing sulfur discharged from a boiler main body 1 to a chimney 10, and an induction ventilator 3 provided in the exhaust gas line 2 for inducing exhaust gas discharged from the boiler main body 3. And an induction ventilator gas flow rate control damper 4 for adjusting the flow rate of the exhaust gas induced by the induction ventilator 3, and disposed in the exhaust gas line 2 downstream of the induction ventilator 3 and from the exhaust gas. A desulfurization device 5 for removing sulfur, a desulfurization ventilator 6 provided in the exhaust gas line 2 on the downstream side of the desulfurization device 5, and desulfurization attracted by the desulfurization ventilator 6 and passing through the desulfurization device 5 A desulfurization ventilator gas flow rate control damper 7 for adjusting the gas flow rate, and an exhaust gas that branches off the exhaust gas line 2 between the induction ventilator 3 and the desulfurization device 5 and that is downstream of the desulfurization ventilator 6. Desulfurization bypass line 8 connected to the line 2 way, a gas flow control device of the desulfurization apparatus having a desulfurization bypass damper 9 provided midway the desulfurization bypass line 8,
An exhaust gas flow rate detector 27 for detecting an exhaust gas flow rate 26 discharged from the boiler body 1;
A desulfurization gas flow rate detector 29 for detecting a desulfurization gas flow rate 28 that has passed through the desulfurization device 5,
A desulfurization bypass damper differential pressure detector 12 for detecting a differential pressure 13 on the upstream side and the downstream side of the desulfurization bypass damper 9,
A function generator 14 for outputting a desulfurization ventilator gas flow control damper basic opening command 15 based on the induced ventilator gas flow control damper opening command 11;
A subtractor 16 that calculates a difference between the differential pressure 13 detected by the desulfurization bypass damper differential pressure detector 12 and a desulfurization bypass damper differential pressure target value 17 and outputs a differential pressure deviation signal 18;
Proportional integration controller that performs a proportional integral process on the differential pressure deviation signal 18 output from the subtracter 16 and outputs a desulfurization ventilator gas flow rate control damper opening correction command 20 for setting the differential pressure deviation signal 18 to 0. 19,
A function generator 31 that outputs a desulfurization gas flow rate target value 30 based on the exhaust gas flow rate 26 detected by the exhaust gas flow rate detector 27;
A subtracter 33 that obtains a difference between a desulfurization gas flow rate 28 detected by the desulfurization gas flow rate detector 29 and a desulfurization gas flow rate target value 30 output from the function generator 31, and outputs a desulfurization gas flow rate deviation signal 32;
Proportional integration processing of the desulfurization gas flow deviation signal 32 output from the subtracter 33 and outputting a desulfurization ventilator gas flow control damper opening correction command 34 for setting the desulfurization gas flow deviation signal 32 to 0 A regulator 35;
When the desulfurization bypass damper 9 is closed, a desulfurization ventilator gas flow rate control damper opening correction command 20 from a proportional integration controller 19 for proportionally integrating the differential pressure deviation signal 18 is output as a signal 22, while the desulfurization bypass damper 9 is output. A switching relay 21 for outputting as a signal 22 a desulfurization ventilator gas flow control damper opening correction command 34 from a proportional-integral controller 35 for proportionally integrating the desulfurization gas flow deviation signal 32 when opened;
The sum of the basic opening degree command 15 for the desulfurization ventilator gas flow control damper output from the function generator 14 and the signal 22 output from the switching relay 21 is obtained, and the opening degree command is sent to the desulfurization ventilator gas flow rate control damper 7. And an adder 24 for outputting the output signal 25.
[0012]
[Action]
Therefore, during normal operation in which the desulfurization device 5 has no failure or the like and the desulfurization bypass damper 9 is closed, it is based on the induction ventilator gas flow control damper opening degree command 11 output in response to the boiler furnace internal pressure control command. The opening degree of the induction ventilator gas flow control damper 4 is adjusted, and the induction ventilator gas flow control damper opening command 11 is input to a function generator 14, which controls the induction ventilator gas flow control. Based on the damper opening command 11, the desulfurization ventilator gas flow control damper basic opening command 15 is output to the adder 24, and the desulfurization bypass damper differential pressure detector 12 detects the differential pressure 13 between the upstream side and the downstream side of the desulfurization bypass damper 9. Is detected, the difference between the differential pressure 13 and the desulfurization bypass damper differential pressure target value 17 is obtained in the subtractor 16, and the differential pressure deviation signal 18 is output to the proportional-integral controller 19, In the proportional integral controller 19, the differential pressure deviation signal 18 is proportionally integrated, and a desulfurization ventilator gas flow rate control damper opening correction command 20 for setting the differential pressure deviation signal 18 to 0 is output to the switching relay 21. The desulfurization ventilator gas flow rate control damper opening correction command 20 is output from the switching relay 21 to the adder 24 as a signal 22, and the desulfurization ventilator gas flow rate control damper output from the function generator 14 at the adder 24 is opened. The sum of the degree command 15 and the signal 22 output from the switching relay 21 is obtained, and an opening command 25 is output to the desulfurization ventilator gas flow rate control damper 7 to adjust the opening degree. As a result, control is performed such that the downstream pressure of the desulfurization bypass damper 9 in the desulfurization bypass line 8 is slightly higher than the upstream pressure, and the untreated gas before desulfurization is processed. The exhaust gas from leaking to the outside through the desulfurization bypass damper 9 desulfurization bypass line 8 is prevented.
[0013]
On the other hand, if the desulfurization bypass damper 9 is opened in the event that the gas gas heater, the mist eliminator or the like of the desulfurization device 5 fails, the function generator 31 outputs the value based on the exhaust gas flow rate 26 detected by the exhaust gas flow rate detector 27. A desulfurization gas flow rate target value 30 is output to a subtractor 33, where the desulfurization gas flow rate 28 detected by the desulfurization gas flow rate detector 29 and the desulfurization gas flow rate target value 30 output from the function generator 31 are output. The desulfurization gas flow deviation signal 32 is output to the proportional-integral controller 35, and the desulfurization gas flow deviation signal 32 output from the subtractor 33 is proportional-integrated in the proportional-integral controller 35. A desulfurization ventilator gas flow rate control damper opening correction command 34 for setting the desulfurization gas flow rate deviation signal 32 to 0 is output to the switching relay 21. The desulfurization ventilator gas flow control damper opening correction command 34 is output as a signal 22 to the adder 24, and the desulfurization ventilator gas flow control damper basic opening command 15 output from the function generator 14 in the adder 24. And the signal 22 output from the switching relay 21 is obtained, and an opening command 25 is output to the desulfurization ventilator gas flow control damper 7, and the opening degree of the desulfurization ventilator gas flow control damper 7 is adjusted. Thus, control is performed such that the desulfurization gas flow rate 28 becomes the desulfurization gas flow rate target value 30.
[0014]
Here, if the desulfurization gas flow rate target value 30 is set to a value larger than the exhaust gas flow rate 26 by the required amount α, the required amount α of desulfurized exhaust gas flows from the downstream side to the upstream side of the desulfurization bypass line 8. The exhaust gas is returned to the exhaust gas line 2 on the upstream side of the desulfurization device 5, and as a result, untreated exhaust gas before desulfurization is not released from the chimney 10 to the atmosphere via the desulfurization bypass damper 9 of the desulfurization bypass line 8.
[0015]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0016]
FIG. 1 shows an embodiment of the present invention. In FIG. 1, portions denoted by the same reference numerals as those in FIG. 3 represent the same components, and are provided in the exhaust gas line 2 on the upstream side of the induced draft gas flow control damper 4. An exhaust gas flow rate detector 27 for detecting an exhaust gas flow rate 26 discharged from the boiler main body 1, and a desulfurization gas flow rate 28 passing through the desulfurization device 5 in the exhaust gas line 2 upstream of the desulfurization ventilator gas flow rate control damper 7. A function generator 31 for outputting a desulfurization gas flow rate target value 30 based on the exhaust gas flow rate 26 detected by the exhaust gas flow rate detector 27; and a desulfurization gas flow rate detector 29. The difference between the desulfurization gas flow rate 28 detected in the above and the desulfurization gas flow rate target value 30 output from the function generator 31 is determined, and a subtractor 33 for outputting a desulfurization gas flow rate deviation signal 32 is provided. Proportional integration processing of the desulfurization gas flow rate deviation signal 32 to be input and outputting a desulfurization ventilator gas flow rate control damper opening correction command 34 for setting the desulfurization gas flow rate deviation signal 32 to 0 to the switching relay 21 When the desulfurization bypass damper 9 is closed, the desulfurization ventilator gas flow rate control damper opening correction command 20 from the proportional integration controller 19 is output as a signal 22 from the switching relay 21 while the desulfurization bypass damper 9 is closed. When opened, the desulfurization ventilator gas flow rate control damper opening correction command 34 from the proportional integration controller 35 is output as a signal 22 from the switching relay 21.
[0017]
It should be noted that a function as shown in FIG. 2 is input to the function generator 31, and the function is to always set the desulfurization gas flow rate target value 30 larger than the exhaust gas flow rate 26 by the required amount α. It represents.
[0018]
Next, the operation of the above embodiment will be described.
[0019]
At the time of normal operation in which the desulfurization device 5 has no failure or the like and the desulfurization bypass damper 9 is closed, as in the case of the conventional example shown in FIG. 3, an induction ventilator output in response to a boiler furnace pressure control command. The degree of opening of the induction ventilator gas flow control damper 4 is adjusted based on the gas flow rate control damper opening degree command 11, and the induction ventilation gas flow rate control damper opening degree command 11 is input to a function generator 14. In the generator 14, the desulfurization ventilator gas flow control damper basic opening command 15 is output to the adder 24 based on the induced ventilator gas flow control damper opening command 11, and the desulfurization bypass damper 9 is detected by the desulfurization bypass damper differential pressure detector 12. , The difference between the differential pressure 13 and the desulfurization bypass damper differential pressure target value 17 is determined by the subtractor 16, and the differential pressure deviation signal 18 is proportionally calculated. Output to the minute adjuster 19, the differential pressure deviation signal 18 is proportionally integrated in the proportional integral adjuster 19, and the desulfurization ventilator gas flow rate control damper opening correction command 20 for setting the differential pressure deviation signal 18 to 0 Is output to the switching relay 21, and the desulfurization ventilator gas flow rate control damper opening correction command 20 is output from the switching relay 21 to the adder 24 as a signal 22, and is output from the function generator 14 in the adder 24. The sum of the basic opening degree command 15 for the desulfurization ventilator gas flow rate control damper and the signal 22 output from the switching relay 21 is obtained, and the opening degree command 25 is output to the desulfurization ventilator gas flow rate control damper 7. The opening of the gas flow control damper 7 is adjusted, whereby the downstream pressure of the desulfurization bypass damper 9 in the desulfurization bypass line 8 is controlled to be slightly higher than the upstream pressure. It is performed, and exhaust gas of the untreated before desulfurization is prevented from leaking to the outside through the desulfurization bypass damper 9 desulfurization bypass line 8.
[0020]
On the other hand, if the desulfurization bypass damper 9 is opened in the event that a gas gas heater or mist eliminator (not shown) of the desulfurization device 5 fails, a function based on the exhaust gas flow rate 26 detected by the exhaust gas flow rate detector 27 is used. A desulfurization gas flow rate target value 30 is output from a generator 31 to a subtractor 33, where the desulfurization gas flow rate 28 detected by a desulfurization gas flow rate detector 29 and the desulfurization gas output from the function generator 31 are output. The difference from the target flow rate value 30 is determined, and a desulfurization gas flow deviation signal 32 is output to a proportional-integral controller 35. In the proportional-integral controller 35, the desulfurization gas flow deviation signal 32 output from a subtractor 33 is proportionally integrated. The desulfurization ventilator gas flow rate control damper opening correction command 34 for processing the desulfurization gas flow rate deviation signal 32 to 0 is output to the switching relay 21. The desulfurization ventilator gas flow control damper opening correction command 34 is output from the exchange relay 21 to the adder 24 as a signal 22, and the desulfurization ventilator gas flow control damper basic opening output from the function generator 14 is output from the adder 24. The sum of the degree command 15 and the signal 22 output from the switching relay 21 is obtained, and an opening command 25 is output to the desulfurization ventilator gas flow rate control damper 7 to adjust the opening degree. Accordingly, control is performed such that the desulfurization gas flow rate 28 becomes the desulfurization gas flow rate target value 30, that is, the desulfurization gas flow rate 28 always increases by a required amount α with respect to the exhaust gas flow rate 26.
[0021]
Here, the fact that the desulfurization gas flow rate 28 always exceeds the exhaust gas flow rate 26 by the required amount α means that the desulfurized exhaust gas of the required amount α flows from the downstream side to the upstream side of the desulfurization bypass line 8 and the desulfurization device 5 As a result, the untreated exhaust gas before desulfurization is not released from the chimney 10 to the atmosphere via the desulfurization bypass damper 9 of the desulfurization bypass line 8.
[0022]
Thus, even when the desulfurization bypass damper 9 is opened when a gas gas heater or mist eliminator (not shown) of the desulfurization device 5 fails, the exhaust gas containing sulfur is passed through the desulfurization bypass line 8 without being treated. 10 can be prevented from being released to the atmosphere.
[0023]
It should be noted that the gas flow control device of the desulfurization device of the present invention is not limited to the above-described embodiment, and it is needless to say that various changes can be made without departing from the gist of the present invention.
[0024]
【The invention's effect】
As described above, according to the gas flow control device of the desulfurization device of the present invention, even when the desulfurization bypass damper 9 is opened at the time of failure of the gas gas heater or the mist eliminator of the desulfurization device, the exhaust gas containing sulfur content is discharged. An excellent effect of preventing the untreated gas from being discharged from the chimney 10 to the atmosphere via the desulfurization bypass line 8 can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an embodiment of the present invention.
FIG. 2 is a diagram showing a function set in a function generator 31 shown in FIG.
FIG. 3 is a schematic configuration diagram of a conventional example.
FIG. 4 is a diagram showing functions set in a function generator 14 shown in FIGS. 1 and 3;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Boiler main body 2 Exhaust gas line 3 Induction ventilator 4 Induction ventilator gas flow control damper 5 Desulfurizer 6 Desulfurization ventilator 7 Desulfurization ventilator gas flow control damper 8 Desulfurization bypass line 9 Desulfurization bypass damper 10 Chimney 11 Induction ventilation gas flow control Damper opening command 12 Desulfurization bypass damper differential pressure detector 13 Differential pressure 14 Function generator 15 Desulfurization ventilator gas flow control damper basic opening command 16 Subtractor 17 Desulfurization bypass damper differential pressure target value 18 Differential pressure deviation signal 19 Proportional integration Controller 20 Desulfurization ventilator gas flow control damper opening correction command 21 Switching relay 22 Signal 24 Adder 25 Opening command 26 Exhaust gas flow 27 Exhaust gas flow detector 28 Desulfurization gas flow 29 Desulfurization gas flow detector 30 Desulfurization gas flow target value 31 function generator 32 desulfurization gas flow deviation signal 33 subtractor 34 desulfurization ventilator gas flow control damper Degree correction command 35 proportional integral controller

Claims

An exhaust gas line (2) for guiding exhaust gas containing sulfur discharged from the boiler body (1) to a chimney (10); and an exhaust gas provided in the exhaust gas line (2) and discharged from the boiler body (1). An induction ventilator (3) to be induced, an induction ventilator gas flow control damper (4) for adjusting a flow rate of exhaust gas induced by the induction ventilator (3), and a downstream of the induction ventilator (3) A desulfurization device (5) disposed in the middle of the exhaust gas line (2) for removing sulfur from the exhaust gas, and provided in the middle of the exhaust gas line (2) downstream of the desulfurization device (5). A desulfurization ventilator (6); a desulfurization ventilator gas flow control damper (7) for adjusting the flow rate of desulfurization gas induced by the desulfurization ventilator (6) and passing through the desulfurization device (5); Between the ventilator (3) and the desulfurizer (5) A desulfurization bypass line (8) that branches off in the middle of the exhaust gas line (2) and is connected in the middle of the exhaust gas line (2) downstream of the desulfurization ventilator (6), and is provided in the middle of the desulfurization bypass line (8). A gas flow control device of a desulfurization device provided with a desulfurization bypass damper (9),
An exhaust gas flow detector (27) for detecting an exhaust gas flow (26) discharged from the boiler body (1);
A desulfurization gas flow rate detector (29) for detecting a desulfurization gas flow rate (28) passed through the desulfurization device (5);
A desulfurization bypass damper differential pressure detector (12) for detecting a differential pressure (13) on the upstream side and the downstream side of the desulfurization bypass damper (9);
A function generator (14) for outputting a desulfurization ventilator gas flow control damper basic opening command (15) based on the induced ventilator gas flow control damper opening command (11);
A subtracter (16) for obtaining a difference between the differential pressure (13) detected by the desulfurization bypass damper differential pressure detector (12) and the desulfurization bypass damper differential pressure target value (17) and outputting a differential pressure deviation signal (18). )When,
The differential pressure deviation signal (18) output from the subtractor (16) is proportionally integrated, and the desulfurization ventilator gas flow rate control damper opening correction command (20) for setting the differential pressure deviation signal (18) to 0 is set. ), A proportional-integral controller (19) that outputs
A function generator (31) that outputs a desulfurization gas flow rate target value (30) based on the exhaust gas flow rate (26) detected by the exhaust gas flow rate detector (27);
The difference between the desulfurization gas flow rate (28) detected by the desulfurization gas flow rate detector (29) and the desulfurization gas flow rate target value (30) output from the function generator (31) is obtained, and the desulfurization gas flow rate deviation signal ( 32), which outputs a subtractor (33);
A desulfurization ventilator gas flow rate control damper opening correction command for performing a proportional integration process on the desulfurization gas flow rate deviation signal (32) output from the subtracter (33) and setting the desulfurization gas flow rate deviation signal (32) to 0 A proportional-integral controller (35) for outputting (34);
When the desulfurization bypass damper (9) is closed, a desulfurization ventilator gas flow rate control damper opening correction command (20) from a proportional integration controller (19) for proportionally integrating the differential pressure deviation signal (18 ) is signaled (22). On the other hand, when the desulfurization bypass damper (9) is opened, the desulfurization ventilator gas flow rate control damper opening correction command (34) from the proportional integration controller (35) that performs proportional integration processing of the desulfurization gas flow rate deviation signal (32). ) As a signal (22), a switching relay (21),
The sum of the desulfurization ventilator gas flow control damper basic opening command (15) output from the function generator (14) and the signal (22) output from the switching relay (21) is obtained. An adder (24) for outputting an opening command (25) to a flow control damper (7).