JP3790504B2

JP3790504B2 - Pulverized coal combustion system

Info

Publication number: JP3790504B2
Application number: JP2002232316A
Authority: JP
Inventors: 祥啓出口; 祥規猪澤
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Ltd
Priority date: 2002-08-09
Filing date: 2002-08-09
Publication date: 2006-06-28
Anticipated expiration: 2022-08-09
Also published as: JP2004069251A

Description

【０００１】
【発明の属する技術分野】
本発明は、例えば微粉炭火力プラントのボイラにおける微粉炭燃焼システムに関する。
【０００２】
【背景技術】
例えば火力プラントのボイラに微粉炭を供給する場合、低コスト化のために種々の産地からの石炭が供給されているので、その均一化が図られている。
【０００３】
このため、従来においてはボイラ火炉の温度や石炭を微粉炭にするミルの温度を制御して、燃焼制御することがおこなわれている。
【０００４】
しかしながら、火炉の温度制御やミルの温度制御は過去の情報からの推察による制御であるので、ボイラに供給する直前における微粉炭の性状をリアルタイムに確認し、燃焼制御たいという要望があるが、未だ実用化されていないのが現状である。
【０００５】
そこで、従来では、石炭ヤードの石炭を手分析し、該分析結果から、石炭の切替を予測し、該切替予測に応じて、ボイラの燃焼を制御することが提案されているが、該予測に応じた切替は経験によるものであり、効率的な燃焼制御することができない、という問題がある。
【０００６】
また、ボイラに供給する粉砕手段であるミルが複数ある場合には、ミルにより粉砕条件が異なるので、それらも考慮する必要があるが、従来の方法ではミル温度のみの情報であるので、適切なボイラ燃焼制御を行うことが困難であった。
【０００７】
本発明は上述した問題に鑑み、例えば微粉炭火力プラントのボイラに供給する微粉炭の性状をリアルタイムで計測し、該性状に応じた燃焼制御を効率的に行うことができる微粉炭燃焼システムを提供することを課題とする。
【０００８】
【課題を解決するための手段】
前述した課題を解決する第１の発明は、石炭の微粉炭を各燃焼器へ供給して燃焼させる微粉炭燃焼システムであって、
石炭ヤードからの石炭を微粉砕する粉砕手段と、
該粉砕手段からの微粉炭を燃焼器に供給する微粉炭供給管と、
上記粉砕手段内又は該微粉炭供給管内にレーザ光を照射するレーザ装置と、微粉炭中の固定炭素からのラマン散乱光，Ｃ−Ｈ結合からのラマン散乱光，炭化水素の蛍光を検出する検出器とからなり、微粉炭の燃料比を計測する燃料比計測装置と、
該燃料比計測装置の計測結果から、各微粉炭の燃料比に応じて燃焼を制御する燃焼制御手段とを具備したことを特徴とする微粉炭燃焼システムにある。
【０００９】
第２の発明は、第１の発明において、
上記微粉炭中の固定炭素からのラマン散乱光とＣ−Ｈ結合からのラマン散乱光との比率から燃料比（固体炭素分／揮発分）を求めることを特徴とする微粉炭燃焼システムにある。
【００１０】
第３の発明は、第１又は２の発明において、
上記微粉炭中の固定炭素からのラマン散乱光と炭化水素の蛍光との比率から燃料比を求めることを特徴とする微粉炭燃焼システムにある。
【００１１】
第４の発明は、第１又は２の発明において、
上記レーザ光の波長が３５０〜８００ｎｍであることを特徴とする微粉炭燃焼システムにある。
【００１２】
第５の発明は、石炭ヤードからの石炭を微粉砕する粉砕手段と、
該粉砕手段からの微粉炭を燃焼器に供給する微粉炭供給管と、
上記粉砕手段内又は該微粉炭供給管内にレーザ光を照射するレーザ装置と、微粉炭中の固定炭素からのラマン散乱光，Ｃ−Ｈ結合からのラマン散乱光，炭化水素の蛍光を検出する検出器とからなり、微粉炭の燃料比を計測する燃料比計測装置と、
該燃料比計測装置の計測結果から、各微粉炭の燃料比に応じて燃焼を制御する燃焼制御手段とを具備した微粉炭燃焼システムであって、
上記燃料比計測装置により求めた燃料比の結果から、ボイラ火炉と過熱器・再熱器との熱吸収バランスを制御してバーナ燃焼を制御することを特徴とする微粉炭燃焼システムにある。
【００１３】
第６の発明は、石炭ヤードからの石炭を微粉砕する粉砕手段と、
該粉砕手段からの微粉炭を燃焼器に供給する微粉炭供給管と、
上記粉砕手段内又は該微粉炭供給管内にレーザ光を照射するレーザ装置と、微粉炭中の固定炭素からのラマン散乱光，Ｃ−Ｈ結合からのラマン散乱光，炭化水素の蛍光を検出する検出器とからなり、微粉炭の燃料比を計測する燃料比計測装置と、
該燃料比計測装置の計測結果から、各微粉炭の燃料比に応じて燃焼を制御する燃焼制御手段とを具備した微粉炭燃焼システムであって、
上記燃料比計測装置により求めた燃料比の結果から、バーナ燃焼を制御してボイラ火炉内のＮＯｘ発生量を制御することを特徴とする微粉炭燃焼システムにある。
【００１４】
第７の発明は、石炭ヤードからの石炭を微粉砕する粉砕手段と、
該粉砕手段からの微粉炭を燃焼器に供給する微粉炭供給管と、
上記粉砕手段内又は該微粉炭供給管内にレーザ光を照射するレーザ装置と、微粉炭中の固定炭素からのラマン散乱光，Ｃ−Ｈ結合からのラマン散乱光，炭化水素の蛍光を検出する検出器とからなり、微粉炭の燃料比を計測する燃料比計測装置と、
該燃料比計測装置の計測結果から、各微粉炭の燃料比に応じて燃焼を制御する燃焼制御手段とを具備した微粉炭燃焼システムであって、
上記燃料比計測装置により求めた燃料比の結果から、バーナ燃焼を制御してボイラ火炉内の未燃分量を制御することを特徴とする微粉炭燃焼システムにある。
【００１５】
第８の発明は、石炭ヤードからの石炭を微粉砕する粉砕工程と、
上記粉砕手段内又は該微粉炭を供給する供給管内にレーザ光を照射し、微粉炭中の固定炭素からのラマン散乱光，Ｃ−Ｈ結合からのラマン散乱光，炭化水素の蛍光を検出し、微粉炭中の固定炭素からのラマン散乱光とＣ−Ｈ結合からのラマン散乱光との比率から燃料比（固体炭素分／揮発分）を求め、
該燃料比の結果から、各微粉炭の燃料比に応じて燃焼を制御する燃焼制御手段とを具備した微粉炭燃焼方法であって、
上記燃料比の結果から、ボイラ火炉と過熱器・再熱器との熱吸収バランスを制御してバーナ燃焼を制御することを特徴とする微粉炭燃焼方法にある。
【００１６】
第９の発明は、石炭ヤードからの石炭を微粉砕する粉砕工程と、
上記粉砕手段内又は該微粉炭を供給する供給管内にレーザ光を照射し、微粉炭中の固定炭素からのラマン散乱光，Ｃ−Ｈ結合からのラマン散乱光，炭化水素の蛍光を検出し、微粉炭中の固定炭素からのラマン散乱光とＣ−Ｈ結合からのラマン散乱光との比率から燃料比（固体炭素分／揮発分）を求め、
該燃料比の結果から、各微粉炭の燃料比に応じて燃焼を制御する燃焼制御手段とを具備した微粉炭燃焼方法であって、
上記燃料比の結果から、バーナ燃焼を制御してボイラ火炉内のＮＯｘ発生量を制御することを特徴とする微粉炭燃焼方法にある。
【００１７】
第１０の発明は、石炭ヤードからの石炭を微粉砕する粉砕工程と、
上記粉砕手段内又は該微粉炭を供給する供給管内にレーザ光を照射し、微粉炭中の固定炭素からのラマン散乱光，Ｃ−Ｈ結合からのラマン散乱光，炭化水素の蛍光を検出し、微粉炭中の固定炭素からのラマン散乱光とＣ−Ｈ結合からのラマン散乱光との比率から燃料比（固体炭素分／揮発分）を求め、
該燃料比の結果から、各微粉炭の燃料比に応じて燃焼を制御する燃焼制御手段とを具備した微粉炭燃焼方法であって、
上記燃料比の結果から、バーナ燃焼を制御してボイラ火炉内の未燃分量を制御することを特徴とする微粉炭燃焼方法にある。
【００１８】
【発明の実施の形態】
本発明による実施の形態を以下に説明するが、本発明はこれらの実施の形態に限定されるものではない。
【００１９】
［第１の実施の形態］
図１は本実施の形態にかかる微粉炭燃焼システムの概略図である。
図１に示すように、本実施の形態にかかる微粉炭燃焼システム１００は、石炭ヤード１０１からの石炭１０２を微粉砕する粉砕手段であるミル１０３と、該ミル１０３からの微粉炭１０４を燃焼器であるボイラ火炉１０５のバーナ１０６に供給する微粉炭供給管１０７と、上記微粉炭供給管１０７内にレーザ光を照射するレーザ装置と、微粉炭中の固定炭素からのラマン散乱光，Ｃ−Ｈ結合からのラマン散乱光，炭化水素の蛍光を検出する検出器とからなり、微粉炭の燃料比を計測する燃料比計測装置１１０と、該燃料比計測装置１１０の計測結果から、各微粉炭の燃料比に応じて燃焼を制御する燃焼制御手段１２０とを具備するものである。
【００２０】
上記燃料比計測装置１１０の概略を図２に示す。
図２に示すように、本実施の形態にかかる燃料比計測装置１１０は、ボイラへ供給する微粉炭の燃料比を計測する計測装置であって、微粉炭１０４を供給する供給管１０７にレーザ光１３を照射するレーザ装置１４と、微粉炭１０４中の固定炭素からのラマン散乱光１５、Ｃ−Ｈ結合からのラマン散乱光１６、炭化水素の蛍光１７を検出する光検出器１８とを具備してなるものである。
なお、図２中、符号２１パージ空気、２２はバルブ、２３はビームスプリッタ、２４はフィルタを各々図示する。
ここで、レーザ光装置１４から発振されるレーザ光１３の波長は３５０〜８００ｎｍの範囲とするのが好ましく、更に好ましくは４００〜６００ｎｍの範囲とするとよい。
これは、ラマン散乱光強度は、一般に波長の４乗に反比例するため、波長８００ｎｍを超えると十分な強度が得られない他、赤外光対応の高価な検出器を使用する必要から好ましくないからである。一方、３５０ｎｍよりも波長が短いと、微粉炭に含められる芳香族系炭化水素の蛍光の影響を強く受け、ラマン散乱光がＳ／Ｎ良く検出することができなくなるからである。
４００〜６００ｎｍの範囲とする場合には、信号強度が確保でき、且つ可視領域の廉価な検出器を使用できる他、Ｓ／Ｎ良くラマン散乱光を検出することができ、微粉炭の燃料比を計測することが可能となるからである。
【００２１】
図３に微粉炭の構成模式図を示す。
図３に示すように、微粉炭１０４は、その固定炭素分のほとんどがＣ（炭素）であり、揮発分はＣ（炭素）、Ｈ（水素）からなる低分子量でガスとして揮発しやすい炭化水素（ＨＣ）であり、その他ケイ素（Ｓｉ）、アルミ（Ａｌ）等が含まれている。
【００２２】
図４は上記レーザ光を微粉炭に照射した際におけるラマン散乱光及び蛍光の微粉炭の測定結果である。
レーザ光装置１４から発振されるレーザ光１３の波長は５３２ｎｍとし、固定炭素からのラマン散乱光１５の波長は５７０ｎｍ近傍、Ｃ−Ｈ結合からのラマン散乱光１６の波長は６３０ｎｍ近傍の信号強度を測定し、固定炭素分と揮発分との比率により燃料比を求めた。
【００２３】
これにより微粉炭をボイラに供給している現場にてリアルタイムで測定対象物の燃料比を求めることができるので、その結果に基づき、ボイラの燃焼制御を微粉炭の性状に応じて行うことができる。
【００２４】
図５は本システムに適用する燃料比計測装置の概略図である。
図５に示すように、本実施の形態にかかる他の燃料比計測装置１１０は、複数の微粉炭供給管１０７Ａ、１０７Ｂ、１０７Ｃ…に光ファイバ３１でレーザ光１３を照射するレーザ装置１４と、各々の微粉炭供給管１０７Ａ、１０７Ｂ、１０７Ｃ…における微粉炭１０４中の固定炭素からのラマン散乱光１５Ａ、１５Ｂ、１５Ｃ…、Ｃ−Ｈ結合からのラマン散乱光１６Ａ、１６Ｂ、１６Ｃ…、炭化水素の蛍光１７Ａ、１７Ｂ、１７Ｃ…を検出する分光器３２とＣＣＤカメラ３３からなる光検出器３４とを具備してなるものである。
【００２５】
上記レーザ装置１４と光検出器３４でレーザユニット４１を構成しており、光ファイバ３１により各計測ヘッド４２へレーザ光１３を送ると共に、ラマン散乱光及び蛍光を光ファイバ３１を介して分光器３２へ導いている。
なお、図４中、符号２１パージ空気、２２はバルブ、２３、４３はビームスプリッタ、２４はフィルタを各々図示する。
【００２６】
各計測場１乃至３…には、第１計測ヘッド４２Ａ，第２計測ヘッド４２Ｂ，第３計測ヘッド４２Ｃ…を備えて各供給管内を通過する微粉炭の燃料比を計測するようにしている。
【００２７】
なお、この計測の際に、図６に示すように、レーザユニット４１においてもＣＣＤカメラによる画像で各計測場所の波長スペクトルを計測することで、検出器の簡素化も可能となる。
【００２８】
図７に本測定装置を用いてボイラの燃焼制御のシステムについて説明する。
図７に示すように、ボイラ火炉１０５には複数のバーナ１０６が設けられており、該バーナ１０６には各々微粉炭の供給管１０７が接続され、微粉炭１０４がミル（微粉炭機）１０３から供給されている。
なお、各バーナ１０６ａ〜１０６ｆにおいて、各バーナ段毎のバーナ１０６ａと１０６ｄ、１０６ｂと１０６ｅ、１０６ｃと１０６ｆには、それぞれ同じミル（バーナ１０６ａと１０６ｄには第１ミル１０３Ａ、バーナ１０６ｂと１０６ｅには第１ミル１０３Ｂ、バーナ１０６ｃと１０６ｆには第１ミル１０３Ｃ）からの微粉炭１０４Ａ，１０４Ｂ，１０４Ｃが供給され、同じ性状の微粉炭で燃焼させている。
【００２９】
ここで、複数の微粉炭供給管１０７ａ、１０７ｂ及び１０７ｃには、上述した図５に示す燃料比計測装置１１０の第１乃至第３計測ヘッド４２ａ〜４２ｃが各々が設けられており、光ファイバ３１でレーザユニット４１からレーザ光１４を照射し、各々の微粉炭供給管１０７ａ〜１０７ｃを流れる微粉炭中の固定炭素からのラマン散乱光１５、Ｃ−Ｈ結合からのラマン散乱光１６及び炭化水素の蛍光１７を検出している。
【００３０】
そして、レーザユニット４１において、供給過程における微粉炭中の、例えば固定炭素からのラマン散乱光とＣ−Ｈ結合からのラマン散乱光との比率から燃料比（固体炭素分／揮発分）を求め、燃料比率が変動したら、制御装置１２０からの制御信号ａ，ｂ，ｃによりバーナ１０６等の制御を行い、常に安定した燃焼制御を行うようにしている。
【００３１】
なお、本実施の形態では、微粉炭の性状を計測する場所として、微粉炭の供給管１０７から微粉炭１０４をサンプリングして計測するようにしたが、本発明はこれに限定されず、微粉炭粉砕機であるミル１０３から直接微粉炭１０４の性状を計測するようにしてもよい。
【００３２】
以下に燃料比の制御方法の一例を以下に示す。
ここで、上述した燃料比計測装置１１０により求めた燃料比の結果から制御手段１２０を介してバーナ燃焼等を制御する方法としては、(1) 火炉と過熱器・再熱器との熱吸収バランスを制御方法、(2) ＮＯｘの制御の制御方法、又は(3) 未燃分の制御方法の３つがある。
【００３３】
図８にボイラ火炉の燃焼概念図を示す。図８中、ボイラ火炉２００内は主バーナ燃焼部２０１と、還元脱硝部２０２と、未燃分燃焼完結部２０３とが形成される。
【００３４】
(1) ボイラ火炉と過熱器・再熱器との熱吸収バランスを制御には以下のようにする。
燃料比の特徴として、何も調整しなければ、低燃料比の微粉炭の場合は、燃え切り性がよいので、火炉での熱吸収が良く、一方高燃料比の微粉炭の場合は、燃え切り性が悪いので、再熱器での熱吸収が良くなる。
このような状態で、燃焼を行えば、ボイラでの熱吸収量と過熱器・再熱器（ボイラ出口に設置）での熱吸収量にアンバランスが生じ、負荷変化時に温度制御を行っているスプレやＳＨ・ＲＨパスガスダンパなどの制御に裕度が無くなることになる。
よって、制御代を確保するために、上記燃料比計測装置により求めた燃料比の結果を基にして以下の制御を実施する。
ａ）バーナの点消火パターンを燃料比によって切り替える。
例）低燃料比の場合：燃え切り性がよいので、バーナを火炉の上の方から点火する。
高燃料比の場合：燃え切り性が悪いので、バーナを火炉の下の方から点火する。
ｂ）バーナの角度調節器を制御する。
例）低燃料比の場合：燃え切り性がよいので、バーナ角度を増（上向き）とする。
高燃料比の場合：燃え切り性が悪いので、バーナ角度を減（下向き）とする。
【００３５】
(2) ＮＯｘの制御の制御方法の場合には、以下のようにする。
図７に示す火炉概略図におけるボイラ火炉２００内の還元脱硝領域２０２を確保するために、以下の制御を実施する。
ａ）バーナの角度調節器を制御する。
例）低燃料比の場合：燃え切り性がよいので、バーナ角度をバーナ角度調整器２０４で減（下向き）とする。
高燃料比の場合：燃え切り性が悪いので、バーナ角度をバーナ角度調整器２０４で増（上向き）とする。
また、脱硝制御として、アンモニアの注入量を先行制御する。
例）低燃料比の場合：燃え切り性がよいので、アンモニアを先行注入流量を増とする。
高燃料比の場合：燃え切り性が悪いので、アンモニアの先行注入流量を減とする。
【００３６】
(3) 未燃分の制御方法の場合には、以下のようにする。
図７に示すボイラ火炉２００内の未燃分燃焼完結部２０３を確保するために、以下の制御を実施する。
ａ）アディショナル・エア（ＡＡ）２０５を供給するアディショナル・エア（ＡＡ）角度調節器２０６を制御する。
例）低燃料比の場合：燃え切り性がよいので、アディショナル・エアの角度を減（下向き）とする。
高燃料比の場合：燃え切り性が悪いので、アディショナル・エアの角度を増（上向き）とする。
ｂ）アディショナル・エア２０５の供給するアディショナル・エアダンパ調節器２０７を制御する。
例）低燃料比の場合：燃え切り性がよいので、アディショナル・エアダンパを閉方向に動作させる。
高燃料比の場合：燃え切り性が悪いので、アディショナル・エアダンパを開方向に動作させる。
【００３７】
以上のような制御を微粉炭の性状に応じて行うことにより、微粉炭の性状に応じてボイラの燃焼を安定化させることができる。
【００３８】
従来では、ボイラ火炉の温度や石炭を微粉炭にするミルの温度を制御して、燃焼制御することがおこなわれていたが、本発明によれば、火炉の温度制御やミルの温度制御を過去の情報からの推察による制御のような不確定な要素による制御ではなく、ボイラ火炉に供給する直前における微粉炭の性状をリアルタイムに計測しつつ火炉の燃焼を制御を行うことができるので、供給する微粉炭の性状に応じて個別的な細やかな制御を行うことができ、より安定した燃焼を行うことができる。
【００３９】
この結果、様々な性状の石炭の種類を同一ボイラ火炉にミルを介して各々の微粉炭供給管から供給した場合においても、その石炭の種類が大幅に変動しても、リアルタイムに火炉の燃焼制御を行うことができる。
【００４０】
【発明の効果】
以上の説明したように、本発明によれば、石炭の微粉炭を各燃焼器へ供給して燃焼させる微粉炭燃焼システムであって、石炭ヤードからの石炭を微粉砕する粉砕手段と、該粉砕手段からの微粉炭を燃焼器に供給する微粉炭供給管と、上記粉砕手段内又は該微粉炭供給管内にレーザ光を照射するレーザ装置と、微粉炭中の固定炭素からのラマン散乱光，Ｃ−Ｈ結合からのラマン散乱光，炭化水素の蛍光を検出する検出器とからなり、微粉炭の燃料比を計測する燃料比計測装置と、
該燃料比計測装置の計測結果から、各微粉炭の燃料比に応じて燃焼を制御する燃焼制御手段とを具備したので、その結果に基づき、ボイラの燃焼制御を微粉炭の性状に応じて行うことができる。
【図面の簡単な説明】
【図１】本実施の形態にかかる微粉炭燃焼システムの概略図である。
【図２】本実施の形態にかかる燃料比計測装置の概略図である。
【図３】微粉炭の構成模式図である。
【図４】レーザ光を微粉炭に照射した際におけるラマン散乱光及び蛍光の微粉炭の測定結果図である。
【図５】本実施の形態にかかる燃料比計測装置の概略図である。
【図６】ＣＣＤカメラによる画像の一例を示す図である。
【図７】ボイラに適用した構成概略図である。
【図８】ボイラ火炉の概略図である。
【符号の説明】
１１微粉炭
１２供給管
１３レーザ光
１４レーザ装置
１５ラマン散乱光
１６Ｃ−Ｈ結合からのラマン散乱光
１７炭化水素の蛍光
１８光検出器
１００微粉炭燃焼システム
１０１石炭ヤード
１０２石炭
１０３ミル
１０４微粉炭
１０５ボイラ火炉
１０６バーナ
１０７微粉炭供給管
１１０燃料比計測装置
１２０燃焼制御手段
２００ボイラ火炉
２０１主バーナ燃焼部
２０２還元脱硝部
２０３未燃分燃焼完結部
２０４バーナ角度調節器
２０５アディショナル・エア
２０６アディショナル・エア角度調節器
２０７アディショナル・エアダンパ調節器[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pulverized coal combustion system in a boiler of a pulverized coal thermal power plant, for example.
[0002]
[Background]
For example, when supplying pulverized coal to the boiler of a thermal power plant, since the coal from various production areas is supplied for cost reduction, the equalization is achieved.
[0003]
For this reason, conventionally, combustion control is performed by controlling the temperature of a boiler furnace or the temperature of a mill that turns coal into pulverized coal.
[0004]
However, furnace temperature control and mill temperature control are controls based on inferences from past information, so there is a desire to check the properties of pulverized coal immediately before being supplied to the boiler in real time and to control combustion, but still At present, it has not been put into practical use.
[0005]
Therefore, conventionally, it has been proposed to manually analyze the coal in the coal yard, predict coal switching from the analysis result, and control boiler combustion in accordance with the switching prediction. The corresponding switching is based on experience, and there is a problem that efficient combustion control cannot be performed.
[0006]
In addition, when there are a plurality of mills as pulverization means to be supplied to the boiler, the pulverization conditions differ depending on the mills. It was difficult to perform boiler combustion control.
[0007]
In view of the above-described problems, the present invention provides a pulverized coal combustion system capable of measuring properties of pulverized coal supplied to a boiler of a pulverized coal thermal power plant in real time and efficiently performing combustion control according to the properties. The task is to do.
[0008]
[Means for Solving the Problems]
1st invention which solves the subject mentioned above is a pulverized coal combustion system which supplies and burns coal pulverized coal to each combustor,
Pulverizing means for pulverizing coal from the coal yard;
Pulverized coal supply pipe for supplying pulverized coal from the pulverizing means to a combustor;
Laser apparatus for irradiating laser light into the pulverizing means or the pulverized coal supply pipe, and detection for detecting Raman scattered light from fixed carbon in pulverized coal, Raman scattered light from C—H bond, and hydrocarbon fluorescence A fuel ratio measuring device for measuring the fuel ratio of pulverized coal,
A pulverized coal combustion system comprising combustion control means for controlling combustion according to the fuel ratio of each pulverized coal from the measurement result of the fuel ratio measuring device.
[0009]
According to a second invention, in the first invention,
In the pulverized coal combustion system, a fuel ratio (solid carbon content / volatile content) is obtained from a ratio of Raman scattered light from fixed carbon and Raman scattered light from C—H bond in the pulverized coal.
[0010]
According to a third invention, in the first or second invention,
In the pulverized coal combustion system, a fuel ratio is obtained from a ratio of Raman scattered light from fixed carbon in the pulverized coal and fluorescence of hydrocarbons.
[0011]
4th invention is 1st or 2nd invention,
In the pulverized coal combustion system, the wavelength of the laser beam is 350 to 800 nm.
[0012]
5th invention, the grinding | pulverization means to pulverize the coal from a coal yard,
Pulverized coal supply pipe for supplying pulverized coal from the pulverizing means to a combustor;
Laser apparatus for irradiating laser light into the pulverizing means or the pulverized coal supply pipe, and detection for detecting Raman scattered light from fixed carbon in pulverized coal, Raman scattered light from C—H bond, and hydrocarbon fluorescence A fuel ratio measuring device for measuring the fuel ratio of pulverized coal,
From the measurement result of the fuel ratio measuring device, a pulverized coal combustion system comprising combustion control means for controlling combustion according to the fuel ratio of each pulverized coal,
In the pulverized coal combustion system, burner combustion is controlled by controlling the heat absorption balance between the boiler furnace and the superheater / reheater from the result of the fuel ratio obtained by the fuel ratio measuring device.
[0013]
6th invention, the grinding | pulverization means to pulverize the coal from a coal yard,
Pulverized coal supply pipe for supplying pulverized coal from the pulverizing means to a combustor;
Laser apparatus for irradiating laser light into the pulverizing means or the pulverized coal supply pipe, and detection for detecting Raman scattered light from fixed carbon in pulverized coal, Raman scattered light from C—H bond, and hydrocarbon fluorescence A fuel ratio measuring device for measuring the fuel ratio of pulverized coal,
From the measurement result of the fuel ratio measuring device, a pulverized coal combustion system comprising combustion control means for controlling combustion according to the fuel ratio of each pulverized coal,
In the pulverized coal combustion system, burner combustion is controlled from the result of the fuel ratio obtained by the fuel ratio measuring device to control the amount of NOx generated in the boiler furnace.
[0014]
The seventh invention comprises a pulverizing means for pulverizing coal from a coal yard,
Pulverized coal supply pipe for supplying pulverized coal from the pulverizing means to a combustor;
Laser apparatus for irradiating laser light into the pulverizing means or the pulverized coal supply pipe, and detection for detecting Raman scattered light from fixed carbon in pulverized coal, Raman scattered light from C—H bond, and hydrocarbon fluorescence A fuel ratio measuring device for measuring the fuel ratio of pulverized coal,
From the measurement result of the fuel ratio measuring device, a pulverized coal combustion system comprising combustion control means for controlling combustion according to the fuel ratio of each pulverized coal,
In the pulverized coal combustion system, burner combustion is controlled from the result of the fuel ratio obtained by the fuel ratio measuring device to control the amount of unburned fuel in the boiler furnace.
[0015]
The eighth invention is a pulverization step for finely pulverizing coal from a coal yard;
Irradiating laser light into the pulverizing means or a supply pipe for supplying the pulverized coal to detect Raman scattered light from fixed carbon in the pulverized coal, Raman scattered light from C—H bonds, and hydrocarbon fluorescence, The fuel ratio (solid carbon content / volatile content) is determined from the ratio of the Raman scattered light from the fixed carbon in the pulverized coal and the Raman scattered light from the C—H bond,
From the result of the fuel ratio, a pulverized coal combustion method comprising combustion control means for controlling combustion according to the fuel ratio of each pulverized coal,
From the result of the fuel ratio, the burner combustion is controlled by controlling the heat absorption balance between the boiler furnace and the superheater / reheater.
[0016]
A ninth invention comprises a pulverization step for finely pulverizing coal from a coal yard,
Irradiating laser light into the pulverizing means or a supply pipe for supplying the pulverized coal to detect Raman scattered light from fixed carbon in the pulverized coal, Raman scattered light from C—H bonds, and hydrocarbon fluorescence, The fuel ratio (solid carbon content / volatile content) is determined from the ratio of the Raman scattered light from the fixed carbon in the pulverized coal and the Raman scattered light from the C—H bond,
From the result of the fuel ratio, a pulverized coal combustion method comprising combustion control means for controlling combustion according to the fuel ratio of each pulverized coal,
In the pulverized coal combustion method, the burner combustion is controlled from the result of the fuel ratio to control the amount of NOx generated in the boiler furnace.
[0017]
The tenth invention comprises a pulverization step for finely pulverizing coal from a coal yard,
Irradiating laser light into the pulverizing means or a supply pipe for supplying the pulverized coal to detect Raman scattered light from fixed carbon in the pulverized coal, Raman scattered light from C—H bonds, and hydrocarbon fluorescence, The fuel ratio (solid carbon content / volatile content) is determined from the ratio of the Raman scattered light from the fixed carbon in the pulverized coal and the Raman scattered light from the C—H bond,
From the result of the fuel ratio, a pulverized coal combustion method comprising combustion control means for controlling combustion according to the fuel ratio of each pulverized coal,
A pulverized coal combustion method is characterized in that burner combustion is controlled from the result of the fuel ratio to control the amount of unburned fuel in the boiler furnace.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments according to the present invention will be described below, but the present invention is not limited to these embodiments.
[0019]
[First Embodiment]
FIG. 1 is a schematic view of a pulverized coal combustion system according to the present embodiment.
As shown in FIG. 1, a pulverized coal combustion system 100 according to the present embodiment includes a mill 103 which is a pulverizing means for pulverizing coal 102 from a coal yard 101, and a pulverized coal 104 from the mill 103 as a combustor. The pulverized coal supply pipe 107 supplied to the burner 106 of the boiler furnace 105, the laser device for irradiating the pulverized coal supply pipe 107 with laser light, the Raman scattered light from the fixed carbon in the pulverized coal, C—H It consists of a detector that detects Raman scattered light from the bond and fluorescence of hydrocarbons, and a fuel ratio measuring device 110 that measures the fuel ratio of the pulverized coal, and from the measurement result of the fuel ratio measuring device 110, Combustion control means 120 for controlling combustion according to the fuel ratio is provided.
[0020]
An outline of the fuel ratio measuring device 110 is shown in FIG.
As shown in FIG. 2, a fuel ratio measuring device 110 according to the present embodiment is a measuring device that measures the fuel ratio of pulverized coal supplied to a boiler, and laser light is supplied to a supply pipe 107 that supplies pulverized coal 104. 13 and a photodetector 18 for detecting Raman scattered light 15 from fixed carbon in pulverized coal 104, Raman scattered light 16 from C—H bond, and hydrocarbon fluorescence 17. It will be.
In FIG. 2, reference numeral 21 indicates purge air, 22 is a valve, 23 is a beam splitter, and 24 is a filter.
Here, the wavelength of the laser beam 13 oscillated from the laser beam device 14 is preferably in the range of 350 to 800 nm, and more preferably in the range of 400 to 600 nm.
This is because the Raman scattered light intensity is generally inversely proportional to the fourth power of the wavelength, so that if the wavelength exceeds 800 nm, sufficient intensity cannot be obtained, and it is not preferable because it is necessary to use an expensive detector for infrared light. It is. On the other hand, if the wavelength is shorter than 350 nm, it is strongly influenced by the fluorescence of aromatic hydrocarbons contained in the pulverized coal, and Raman scattered light cannot be detected with good S / N.
In the range of 400 to 600 nm, signal intensity can be secured and an inexpensive detector in the visible region can be used, Raman scattered light can be detected with good S / N, and the fuel ratio of pulverized coal can be increased. It is because it becomes possible to measure.
[0021]
FIG. 3 shows a schematic configuration diagram of pulverized coal.
As shown in FIG. 3, the pulverized coal 104 is mostly C (carbon) in the fixed carbon content, and the volatile content is a low molecular weight hydrocarbon consisting of C (carbon) and H (hydrogen) and easily volatilized as a gas. (HC), which includes silicon (Si), aluminum (Al), and the like.
[0022]
FIG. 4 shows the measurement results of Raman scattered light and fluorescent pulverized coal when the pulverized coal is irradiated with the laser light.
The wavelength of the laser beam 13 oscillated from the laser beam device 14 is 532 nm, the wavelength of the Raman scattered light 15 from the fixed carbon is around 570 nm, and the wavelength of the Raman scattered light 16 from the C—H bond is around 630 nm. The fuel ratio was determined from the ratio between the fixed carbon content and the volatile content.
[0023]
As a result, the fuel ratio of the object to be measured can be obtained in real time at the site where the pulverized coal is supplied to the boiler. Based on the result, the combustion control of the boiler can be performed according to the properties of the pulverized coal. .
[0024]
FIG. 5 is a schematic diagram of a fuel ratio measuring device applied to this system.
As shown in FIG. 5, another fuel ratio measuring apparatus 110 according to the present embodiment includes a laser apparatus 14 that irradiates a plurality of pulverized coal supply pipes 107A, 107B, 107C,. The Raman scattered light 15A, 15B, 15C ... from the fixed carbon in the pulverized coal 104 in each pulverized coal supply pipe 107A, 107B, 107C ..., the Raman scattered light 16A, 16B, 16C ... from the CH bond, hydrocarbons Are provided with a spectroscope 32 for detecting the fluorescence 17A, 17B, 17C... And a photodetector 34 comprising a CCD camera 33.
[0025]
A laser unit 41 is configured by the laser device 14 and the photodetector 34, and the laser beam 13 is sent to each measuring head 42 by the optical fiber 31, and the Raman scattered light and the fluorescence are transmitted through the optical fiber 31 to the spectroscope 32. Leading to.
In FIG. 4, reference numeral 21 indicates purge air, 22 is a valve, 23 and 43 are beam splitters, and 24 is a filter.
[0026]
Each of the measurement fields 1 to 3 is provided with a first measurement head 42A, a second measurement head 42B, a third measurement head 42C, etc., and measures the fuel ratio of the pulverized coal passing through the supply pipes.
[0027]
In this measurement, as shown in FIG. 6, the detector can also be simplified by measuring the wavelength spectrum of each measurement location in the laser unit 41 using an image from a CCD camera.
[0028]
FIG. 7 illustrates a boiler combustion control system using this measuring apparatus.
As shown in FIG. 7, the boiler furnace 105 is provided with a plurality of burners 106, each of which is connected to a pulverized coal supply pipe 107, and the pulverized coal 104 is fed from a mill (pulverized coal machine) 103. Have been supplied.
In each of the burners 106a to 106f, the burners 106a and 106d, 106b and 106e, 106c and 106f for each burner stage have the same mill (the first mill 103A for the burners 106a and 106d, the burners 106b and 106e, The first mill 103B and burners 106c and 106f are supplied with pulverized coal 104A, 104B, 104C from the first mill 103C) and burned with pulverized coal having the same properties.
[0029]
Here, the plurality of pulverized coal supply pipes 107a, 107b, and 107c are provided with the first to third measurement heads 42a to 42c of the fuel ratio measuring apparatus 110 shown in FIG. Irradiate the laser beam 14 from the laser unit 41, the Raman scattered light 15 from the fixed carbon in the pulverized coal flowing through the pulverized coal supply pipes 107a to 107c, the Raman scattered light 16 from the C—H bond, and the hydrocarbons. Fluorescence 17 is detected.
[0030]
In the laser unit 41, the fuel ratio (solid carbon content / volatile content) is obtained from the ratio of Raman scattered light from, for example, fixed carbon and Raman scattered light from C—H bonds in the pulverized coal in the supply process, When the fuel ratio fluctuates, the burner 106 and the like are controlled by the control signals a, b, and c from the control device 120 so that stable combustion control is always performed.
[0031]
In this embodiment, the pulverized coal 104 is sampled and measured from the pulverized coal supply pipe 107 as a place for measuring the properties of the pulverized coal. However, the present invention is not limited to this, and the pulverized coal is measured. You may make it measure the property of the pulverized coal 104 directly from the mill 103 which is a grinder.
[0032]
An example of the fuel ratio control method is shown below.
Here, as a method for controlling the burner combustion or the like via the control means 120 from the fuel ratio result obtained by the fuel ratio measuring device 110 described above, (1) the heat absorption balance between the furnace and the superheater / reheater There are three control methods: (2) NOx control method, and (3) unburned content control method.
[0033]
FIG. 8 shows a combustion conceptual diagram of a boiler furnace. In FIG. 8, a main burner combustion part 201, a reduction denitration part 202, and an unburned part combustion completion part 203 are formed in the boiler furnace 200.
[0034]
(1) The heat absorption balance between the boiler furnace and the superheater / reheater is controlled as follows.
As a characteristic of the fuel ratio, if nothing is adjusted, pulverized coal with a low fuel ratio has good burn-out characteristics, so heat absorption in the furnace is good, while pulverized coal with a high fuel ratio burns. Since cutting performance is poor, heat absorption by the reheater is improved.
If combustion is performed in such a state, there is an imbalance between the amount of heat absorbed by the boiler and the amount of heat absorbed by the superheater / reheater (installed at the boiler outlet), and temperature control is performed when the load changes. There will be no allowance for control of spray and SH / RH pass gas dampers.
Therefore, in order to secure the control allowance, the following control is performed based on the result of the fuel ratio obtained by the fuel ratio measuring device.
a) The burner point-extinguishing pattern is switched depending on the fuel ratio.
Example) Low fuel ratio: Since burnout is good, the burner is ignited from the top of the furnace.
When the fuel ratio is high: Since burnout is poor, the burner is ignited from the bottom of the furnace.
b) Control the burner angle adjuster.
Example) Low fuel ratio: Since burnout is good, increase the burner angle (upward).
For high fuel ratio: Burnout angle is reduced (downward) because burnout is poor.
[0035]
(2) In the case of the control method of NOx control, the following is performed.
In order to secure the reducing denitration region 202 in the boiler furnace 200 in the schematic diagram of the furnace shown in FIG. 7, the following control is performed.
a) Control the burner angle adjuster.
Example) When the fuel ratio is low: Since burnout is good, the burner angle is reduced (downward) by the burner angle adjuster 204.
In the case of a high fuel ratio: Since burnout is poor, the burner angle is increased (upward) by the burner angle adjuster 204.
As denitration control, the amount of ammonia injected is controlled in advance.
Example) When the fuel ratio is low: Since the burnout is good, the ammonia pre-injection flow rate is increased.
In the case of a high fuel ratio: Since the burn-out property is poor, the ammonia pre-injection flow rate is reduced.
[0036]
(3) In the case of the control method for unburned matter, the following shall be performed.
In order to secure the unburned portion combustion completion portion 203 in the boiler furnace 200 shown in FIG. 7, the following control is performed.
a) Controlling an additional air (AA) angle adjuster 206 that supplies additional air (AA) 205.
Example) Low fuel ratio: Since the burnout is good, the angle of additional air is reduced (downward).
For high fuel ratio: Since burnout is poor, increase the angle of additional air (upward).
b) The additional air damper adjuster 207 supplied by the additional air 205 is controlled.
Example) Low fuel ratio: Since the burnout is good, the additional air damper is operated in the closing direction.
When the fuel ratio is high: Since the burnout is poor, the additional air damper is operated in the opening direction.
[0037]
By performing the control as described above according to the properties of the pulverized coal, combustion of the boiler can be stabilized according to the properties of the pulverized coal.
[0038]
Conventionally, combustion temperature control has been performed by controlling the temperature of the boiler furnace and the temperature of the mill that turns coal into pulverized coal. However, according to the present invention, the temperature control of the furnace and the temperature control of the mill have been performed in the past. Because it is possible to control the combustion of the furnace while measuring in real time the properties of the pulverized coal immediately before being supplied to the boiler furnace, rather than the control by an uncertain element such as the control by inference from the information of Individual fine control can be performed according to the properties of pulverized coal, and more stable combustion can be performed.
[0039]
As a result, even when coal types of various properties are supplied to the same boiler furnace from each pulverized coal supply pipe via a mill, the combustion control of the furnace is performed in real time even if the coal type fluctuates significantly. It can be performed.
[0040]
【The invention's effect】
As described above, according to the present invention, a pulverized coal combustion system for supplying pulverized coal to each combustor and combusting it, pulverizing means for pulverizing coal from a coal yard, and the pulverization A pulverized coal supply pipe for supplying pulverized coal from the means to the combustor, a laser device for irradiating the pulverizing means or the pulverized coal supply pipe with a laser beam, Raman scattered light from fixed carbon in the pulverized coal, C A fuel ratio measuring device for measuring the fuel ratio of pulverized coal, comprising a detector that detects Raman scattered light from -H bonds and fluorescence of hydrocarbons;
From the measurement result of the fuel ratio measuring device, the combustion control means for controlling the combustion according to the fuel ratio of each pulverized coal is provided. Based on the result, the combustion control of the boiler is performed according to the properties of the pulverized coal. be able to.
[Brief description of the drawings]
FIG. 1 is a schematic view of a pulverized coal combustion system according to an embodiment.
FIG. 2 is a schematic diagram of a fuel ratio measuring apparatus according to the present embodiment.
FIG. 3 is a schematic configuration diagram of pulverized coal.
FIG. 4 is a measurement result diagram of Raman scattered light and fluorescent pulverized coal when pulverized coal is irradiated with laser light.
FIG. 5 is a schematic view of a fuel ratio measuring device according to the present embodiment.
FIG. 6 is a diagram illustrating an example of an image obtained by a CCD camera.
FIG. 7 is a schematic configuration diagram applied to a boiler.
FIG. 8 is a schematic view of a boiler furnace.
[Explanation of symbols]
11 Pulverized Coal 12 Supply Pipe 13 Laser Light 14 Laser Device 15 Raman Scattered Light 16 Raman Scattered Light from CH Bond 17 Fluorescence of Hydrocarbon 18 Photodetector 100 Pulverized Coal Combustion System 101 Coal Yard 102 Coal 103 Mill 104 Pulverized Coal 105 Boiler furnace 106 Burner 107 Pulverized coal supply pipe 110 Fuel ratio measuring device 120 Combustion control means 200 Boiler furnace 201 Main burner combustion section 202 Reduction denitration section 203 Unburned-combustion combustion completion section 204 Burner angle adjuster 205 Additional air 206 Additional air Air angle adjuster 207 Additional air damper adjuster

Claims

A pulverized coal combustion system in which pulverized coal of coal is supplied to each combustor and burned,
Pulverizing means for pulverizing coal from the coal yard;
Pulverized coal supply pipe for supplying pulverized coal from the pulverizing means to a combustor;
Laser apparatus for irradiating laser light into the pulverizing means or the pulverized coal supply pipe, and detection for detecting Raman scattered light from fixed carbon in pulverized coal, Raman scattered light from C—H bond, and hydrocarbon fluorescence A fuel ratio measuring device for measuring the fuel ratio of pulverized coal,
A pulverized coal combustion system comprising combustion control means for controlling combustion according to the fuel ratio of each pulverized coal from the measurement result of the fuel ratio measuring device.

In claim 1,
A pulverized coal combustion system, wherein a fuel ratio (solid carbon content / volatile content) is determined from a ratio of Raman scattered light from fixed carbon and Raman scattered light from C—H bonds in the pulverized coal.

In claim 1 or 2,
A pulverized coal combustion system, characterized in that a fuel ratio is obtained from a ratio between Raman scattered light from fixed carbon in the pulverized coal and fluorescence of hydrocarbons.

In claim 1 or 2,
The wavelength of the said laser beam is 350-800 nm, The pulverized coal combustion system characterized by the above-mentioned.

Pulverizing means for pulverizing coal from the coal yard;
Pulverized coal supply pipe for supplying pulverized coal from the pulverizing means to a combustor;
Laser apparatus for irradiating laser light into the pulverizing means or the pulverized coal supply pipe, and detection for detecting Raman scattered light from fixed carbon in pulverized coal, Raman scattered light from C—H bond, and hydrocarbon fluorescence A fuel ratio measuring device for measuring the fuel ratio of pulverized coal,
From the measurement result of the fuel ratio measuring device, a pulverized coal combustion system comprising combustion control means for controlling combustion according to the fuel ratio of each pulverized coal,
A pulverized coal combustion system which controls burner combustion by controlling a heat absorption balance between a boiler furnace and a superheater / reheater based on a fuel ratio result obtained by the fuel ratio measuring device.

Pulverizing means for pulverizing coal from the coal yard;
Pulverized coal supply pipe for supplying pulverized coal from the pulverizing means to a combustor;
Laser apparatus for irradiating laser light into the pulverizing means or the pulverized coal supply pipe, and detection for detecting Raman scattered light from fixed carbon in pulverized coal, Raman scattered light from C—H bond, and hydrocarbon fluorescence A fuel ratio measuring device for measuring the fuel ratio of pulverized coal,
From the measurement result of the fuel ratio measuring device, a pulverized coal combustion system comprising combustion control means for controlling combustion according to the fuel ratio of each pulverized coal,
A pulverized coal combustion system, characterized in that burner combustion is controlled from the result of the fuel ratio obtained by the fuel ratio measuring device to control the amount of NOx generated in the boiler furnace.

Pulverizing means for pulverizing coal from the coal yard;
Pulverized coal supply pipe for supplying pulverized coal from the pulverizing means to a combustor;
Laser apparatus for irradiating laser light into the pulverizing means or the pulverized coal supply pipe, and detection for detecting Raman scattered light from fixed carbon in pulverized coal, Raman scattered light from C—H bond, and hydrocarbon fluorescence A fuel ratio measuring device for measuring the fuel ratio of pulverized coal,
From the measurement result of the fuel ratio measuring device, a pulverized coal combustion system comprising combustion control means for controlling combustion according to the fuel ratio of each pulverized coal,
A pulverized coal combustion system, characterized in that burner combustion is controlled from the result of the fuel ratio obtained by the fuel ratio measuring device to control the amount of unburned fuel in the boiler furnace.

A pulverization process for pulverizing coal from the coal yard;
Irradiating laser light into the pulverizing means or a supply pipe for supplying the pulverized coal to detect Raman scattered light from fixed carbon in the pulverized coal, Raman scattered light from C—H bonds, and hydrocarbon fluorescence, The fuel ratio (solid carbon content / volatile content) is determined from the ratio of the Raman scattered light from the fixed carbon in the pulverized coal and the Raman scattered light from the C—H bond,
From the result of the fuel ratio, a pulverized coal combustion method comprising combustion control means for controlling combustion according to the fuel ratio of each pulverized coal,
A pulverized coal combustion method, wherein burner combustion is controlled by controlling a heat absorption balance between a boiler furnace and a superheater / reheater from the result of the fuel ratio.

A pulverization process for pulverizing coal from the coal yard;
Irradiating laser light into the pulverizing means or a supply pipe for supplying the pulverized coal to detect Raman scattered light from fixed carbon in the pulverized coal, Raman scattered light from C—H bonds, and hydrocarbon fluorescence, The fuel ratio (solid carbon content / volatile content) is determined from the ratio of the Raman scattered light from the fixed carbon in the pulverized coal and the Raman scattered light from the C—H bond,
From the result of the fuel ratio, a pulverized coal combustion method comprising combustion control means for controlling combustion according to the fuel ratio of each pulverized coal,
A pulverized coal combustion method, characterized in that burner combustion is controlled from the result of the fuel ratio to control the amount of NOx generated in the boiler furnace.

A pulverization process for pulverizing coal from the coal yard;
Irradiating laser light into the pulverizing means or a supply pipe for supplying the pulverized coal to detect Raman scattered light from fixed carbon in the pulverized coal, Raman scattered light from C—H bonds, and hydrocarbon fluorescence, The fuel ratio (solid carbon content / volatile content) is determined from the ratio of the Raman scattered light from the fixed carbon in the pulverized coal and the Raman scattered light from the C—H bond,
From the result of the fuel ratio, a pulverized coal combustion method comprising combustion control means for controlling combustion according to the fuel ratio of each pulverized coal,
A pulverized coal combustion method characterized in that burner combustion is controlled from the result of the fuel ratio to control the amount of unburned fuel in the boiler furnace.