JPS63207894A - Control of nox in high efficiency - Google Patents
Control of nox in high efficiencyInfo
- Publication number
- JPS63207894A JPS63207894A JP4210087A JP4210087A JPS63207894A JP S63207894 A JPS63207894 A JP S63207894A JP 4210087 A JP4210087 A JP 4210087A JP 4210087 A JP4210087 A JP 4210087A JP S63207894 A JPS63207894 A JP S63207894A
- Authority
- JP
- Japan
- Prior art keywords
- nox
- concentration
- fuel
- content
- coal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000003245 coal Substances 0.000 claims abstract description 39
- 239000000446 fuel Substances 0.000 claims abstract description 38
- 238000002485 combustion reaction Methods 0.000 claims abstract description 25
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 5
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 5
- 230000003068 static effect Effects 0.000 claims abstract description 3
- 238000002347 injection Methods 0.000 claims description 20
- 239000007924 injection Substances 0.000 claims description 20
- 238000000034 method Methods 0.000 claims description 5
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 4
- 230000033228 biological regulation Effects 0.000 claims description 4
- 239000003546 flue gas Substances 0.000 claims description 4
- 239000007789 gas Substances 0.000 abstract description 20
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 abstract 2
- 229910052757 nitrogen Inorganic materials 0.000 abstract 1
- 230000007423 decrease Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 238000005259 measurement Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 230000002378 acidificating effect Effects 0.000 description 3
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 description 3
- 229910052921 ammonium sulfate Inorganic materials 0.000 description 3
- 235000011130 ammonium sulphate Nutrition 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- 238000005457 optimization Methods 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 238000009423 ventilation Methods 0.000 description 3
- 238000012937 correction Methods 0.000 description 2
- 238000011017 operating method Methods 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000008676 import Effects 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、微粉炭燃焼装置において、多種類の石炭を同
一火炉で燃焼させる際の排ガス中の窒素酸化物を低減す
る運転方法に係り、高効率にして低ＮＯｘ化を図るに好
適な火炉の制御方法に関する。[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an operating method for reducing nitrogen oxides in exhaust gas when multiple types of coal are burned in the same furnace in a pulverized coal combustion device. The present invention relates to a furnace control method suitable for achieving high efficiency and low NOx.
燃料として、多種類の石炭を同一ボイラで微粉状で浮遊
燃焼させるボイラ等にあっては、排ガス中のＮＯｘに関
して以下のことが言える。■燃料比（固定炭素／揮発分
）が高い程ＮＯｘ発生が高くなる。すなわち石炭中に含
有するＮ分は、揮発分並びに固定炭素に偏在することな
く分布しており、燃料比が低い程、揮発分放出時のＮ分
放出率が高くなり、燃料比が高い程多くのＮ分がチャー
中に残留する。そして、揮発分中のＮ分は、バーナ中心
域での還元雰囲気下で短時間に放出されることからＮＯ
ｘへの転換率は低くなるのに対し、チャー中に残留する
Ｎ分は、酸化雰囲気下での燃焼を余儀なくされＮＯｘへ
の転換率が高くなる（第７図参照）。■燃料中のＮ分が
高いほどＮＯｘが高くなる（第２図参照）。■火炉出口
０２（以下Ｅ Ｃｏ○２という）によってＮＯｘ値が影
響を受ける（第４図ＮＯｘ曲線参照）。■同一炭種の場
合は、Ｅ Ｃｏ Ｏ，に対しＮＯｘ値と灰中未燃分とが
相反する特性を有し、従ってＮＯｘを低下させる運転法
は灰中未燃分を高める特性となる（第４図未燃分曲線参
照）と云った特徴をもつ。またＥＣ００２一定の場合で
も、微粉炭の粒度によって燃料比に対する灰中未燃分は
変化する（第３図）。In a boiler or the like in which various types of coal are floatingly burned in the form of fine powder in the same boiler as fuel, the following can be said regarding NOx in the exhaust gas. ■The higher the fuel ratio (fixed carbon/volatile matter), the higher the NOx generation. In other words, the N content in coal is distributed without being unevenly distributed in volatile matter and fixed carbon, and the lower the fuel ratio, the higher the N content release rate when volatile matter is released, and the higher the fuel ratio, the more N content is released. A portion of N remains in the char. Since the N content in the volatile matter is released in a short time under the reducing atmosphere in the center area of the burner, NO
While the conversion rate to x is low, the N content remaining in the char is forced to burn in an oxidizing atmosphere, and the conversion rate to NOx is high (see Figure 7). ■The higher the N content in the fuel, the higher the NOx (see Figure 2). ■The NOx value is affected by the furnace outlet 02 (hereinafter referred to as E Co○2) (see NOx curve in Figure 4). ■In the case of the same coal type, the NOx value and unburned content in the ash have contradictory characteristics with respect to E Co O, so an operating method that reduces NOx has the property of increasing the unburned content in the ash ( (See the unburned content curve in Figure 4). Furthermore, even when EC002 is constant, the unburned content in the ash relative to the fuel ratio changes depending on the particle size of the pulverized coal (Figure 3).
これらの燃料比や燃料中Ｎ分の異なる多種類の石炭を同
一火炉で燃焼させ、且つ環境規制値以内にＮＯｘを抑え
る制御法としては、第５図において説明するように、基
本的には（イ）低ＮＯｘバーナによるＮＯｘレベルの低
下、（ロ）二段燃焼設備の設置と、二段燃焼比の変化、
（ハ）排煙脱硝装置の取付けと、脱硝装置用ＮＨ，注入
比率の変化と云った方法で制御されてきた。As explained in Figure 5, the control method for burning various types of coal with different fuel ratios and N content in the same furnace and suppressing NOx within the environmental regulation values is basically ( b) Reduction of NOx level by low NOx burner, (b) Installation of two-stage combustion equipment and change of two-stage combustion ratio,
(c) Control has been achieved by installing a flue gas denitrification device and changing the injection ratio of NH for the denitrification device.
第５図は、従来から存在する微粉炭焚きボイラ構造例を
、第６図はそのＮＯｘ制御例を示す、第５図において５
石炭は石炭バンカ２ｏから給炭機２１を経て微粉炭機２
２に送られて粉砕され微粉炭が製造される。微粉炭機２
２からの微粉炭は、微粉炭管２３を経由して微粉炭バー
ナ２４によって火炉１へ供給され、風箱１４からの燃焼
用空気とともに火炎２を形成する。尚、風箱１４内には
エアレジスタ２５及び二段燃焼用ＮＯｘポート２６が存
在する。Figure 5 shows an example of the structure of a conventional pulverized coal-fired boiler, and Figure 6 shows an example of its NOx control.
Coal is sent from the coal bunker 2o to the coal feeder 21 and then to the pulverizer 2.
2 and is crushed to produce pulverized coal. Pulverized coal machine 2
The pulverized coal from 2 is supplied to the furnace 1 by the pulverized coal burner 24 via the pulverized coal pipe 23 and forms the flame 2 together with the combustion air from the wind box 14 . Note that an air register 25 and a NOx port 26 for two-stage combustion are present in the wind box 14.
そして、燃焼用空気の調整は、給炭機２１の燃料量に比
例して強圧通風機１１の入口に配置された空気流量制御
ダンパ１２によって行われる。適圧通風機１１からの空
気は、分流して、一方の流れは火炉２からの排熱ガスを
利用した空気予熱器４により予熱された後、二段燃焼用
空気流量制御ダンパ１０あるいはバーナ入口空気ダンパ
１３を経て火炉１内に送られる。尚、前記空気流量制御
ダンパ１２はＥＣｏ○２計３２によってフィードバック
制御されていた。分流した空気の他方の流れは一次通風
機１５を通って、さらに分流して前記空気予熱器４によ
って一部が予熱され熱空気１６となり予熱されなかった
冷空気１７と共に温度制御ダンパ１８を介して混合され
て温度制御された後、微粉炭機−次風量制御ダンバ１９
を経て微粉炭機２２内に送られる。The combustion air is adjusted in proportion to the amount of fuel in the coal feeder 21 by an air flow rate control damper 12 disposed at the inlet of the strong pressure fan 11. The air from the appropriate pressure ventilation fan 11 is divided into two streams, and one stream is preheated by an air preheater 4 that uses exhaust heat gas from the furnace 2, and then sent to the two-stage combustion air flow rate control damper 10 or the burner inlet. The air is sent into the furnace 1 via an air damper 13. Note that the air flow rate control damper 12 was feedback-controlled by an ECo◯2 meter 32. The other flow of the divided air passes through the primary ventilator 15 and is further divided into hot air 16 that is partially preheated by the air preheater 4 and is passed through the temperature control damper 18 together with the cold air 17 that has not been preheated. After being mixed and temperature controlled, the pulverized coal machine - next air volume control damper 19
The coal is then sent into the pulverizer 22.
また、ＮＯｘ制御については、燃焼用空気量の１０〜３
０％に相当する量が二段燃焼用空気として分離されて送
られる二段燃焼用空気流量制御ダンパ１０の開度を制御
することによって微粉炭バーナ２４のバーナ口空気比を
制御し、まず火炉１出口のＮＯｘ発生量を抑える。さら
に、排煙脱硝装置（以下Ｄｅ−ＮＯｘ装置という）３へ
配管３４により注入されるＮＨ，注入率を、排ガス中の
ＮＯｘメータ３１によって監視しつつ、ＮＨ，注入量制
御弁３３によって、制御して煙突７の出口ＮＯｘを制御
していたものである。尚、煙道８の途中には電気集塵機
５及び誘引通風機６が設けられる。In addition, regarding NOx control, the amount of combustion air is 10 to 3
The burner port air ratio of the pulverized coal burner 24 is controlled by controlling the opening degree of the two-stage combustion air flow rate control damper 10, in which an amount equivalent to 0% is separated and sent as the second-stage combustion air. Reduces the amount of NOx generated at one outlet. Furthermore, the injection rate of NH injected into the flue gas denitrification device (hereinafter referred to as De-NOx device) 3 through the pipe 34 is controlled by the NH injection amount control valve 33 while being monitored by the NOx meter 31 in the flue gas. This controls the NOx at the exit of the chimney 7. Note that an electric dust collector 5 and an induced draft fan 6 are provided in the middle of the flue 8.
次に第６図を説明する。Next, FIG. 6 will be explained.
まず、空気流量制御ダンパ１２の制御について説明する
。First, control of the air flow rate control damper 12 will be explained.
ボイラ入力信号Ｂ Ｉ Ｄ （１０１）により空気流量
要求信号が作成されるが、この空気流量要求信号は燃焼
に必要な空気流量要求信号となるように過剰空気率を加
算して作成される。過剰空気率は先ず負荷に応じたＥ
Ｃｏ Ｏ，設定を演算器（１０４）により作成し、Ｅ
Ｃｏ Ｏｘ測定信号（１０２）と減算器（ｉｏｓ）によ
り減算しその偏差が積分器（１０６）により積分されて
過剰空気率信号となる。ボイラ入力信号（１０１）と過
剰空気率信号（積分器（１０６）出力）は加算＠ （１
０７）で加算され空気流量要求信号となる。この空気流
量要求信号と空気流量測定信号Ａ Ｆ （１０３）を減
算器（１０ｇ）で減算し、その偏差が零となるように調
節計（比例積分器）（１０９）により空気流量制御ダン
パ（１２）を調節する。尚、Ｈ／Ａ（空気予熱器１１０
，１１３，１２０）は自動手動切替器で通常は自動状態
で使用し、運転員が手動調整するときはＨ／Ａを手動に
切替えて調整する。An air flow rate request signal is created using the boiler input signal BID (101), and this air flow rate request signal is created by adding the excess air rate so that it becomes the air flow rate request signal necessary for combustion. The excess air rate is first determined by E depending on the load.
Co O, settings are created using the calculator (104), and E
The Co Ox measurement signal (102) is subtracted by a subtractor (ios), and the deviation thereof is integrated by an integrator (106) to provide an excess air ratio signal. The boiler input signal (101) and excess air rate signal (integrator (106) output) are added @ (1
07) to form an air flow rate request signal. This air flow rate request signal and air flow rate measurement signal A F (103) are subtracted by a subtractor (10g), and the air flow rate control damper (12 ). In addition, H/A (air preheater 110
, 113, 120) are automatic/manual switching devices that are normally used in an automatic state, and when an operator makes manual adjustments, the H/A is switched to manual.
次に、二段燃焼空気流量制御ダンパ１ｏの制御について
説明する。これは、ボイラ燃焼空気流量に応じて制御ダ
ンパ開度を決定する制御で、空気流量測定信号Ａ ／
Ｆ （１０３）によりダンパ開度設定を演算器（１１２
）で作成し演算器（１１２）の出力信号で２段燃焼用空
気流量制御ダンパ（１０）を調整する。Next, control of the two-stage combustion air flow rate control damper 1o will be explained. This is a control that determines the control damper opening degree according to the boiler combustion air flow rate, and the air flow measurement signal A /
F (103) is used to set the damper opening degree using the calculator (112).
) and adjusts the two-stage combustion air flow rate control damper (10) using the output signal of the computing unit (112).
さらに、ＮＨ３注入流量制御弁（３３）の制御について
説明する。Furthermore, control of the NH3 injection flow rate control valve (33) will be explained.
ＮＨ，注入流量制御は排ガス中のＮＯｘ量に応じてＮＨ
，注入量を調整することによりおこなう。NH, injection flow rate control is based on the amount of NOx in the exhaust gas.
, by adjusting the injection volume.
Ｎ Ｈｓ注入量要求信号は燃焼空気量（排ガス量に相当
）ＡＦ（１０３）と排ガス中のＮＯｘ測定信号（１１５
）を掛算器（１１７）で掛算して作成する。ＮＨ。The N Hs injection amount request signal is based on the combustion air amount (corresponding to the exhaust gas amount) AF (103) and the NOx measurement signal in the exhaust gas (115).
) by the multiplier (117). N.H.
注入量要求信号（（１１７）出力信号）とＮＨ，測定信
号（１１６）を減算器（１１８）で減算しその偏差が零
になるように調節計（比例積分器）（１１９）によりＮ
Ｈ，注入流量制御弁３３を調節する。The injection amount request signal ((117) output signal) and the NH, measurement signal (116) are subtracted by a subtractor (118), and the controller (proportional integrator) (119) subtracts N so that the deviation becomes zero.
H. Adjust the injection flow rate control valve 33.
ところで、要求されるＮＯｘレベルが年々低くなってい
る為、二段燃焼用空気流量制御ダンパ１０は最適化した
結果の最大の開度で使用し、ＮＨ１注入率で調整する方
式が一般的となって来た。By the way, as the required NOx level is getting lower year by year, it has become common to use the two-stage combustion air flow rate control damper 10 at the maximum opening as a result of optimization, and adjust it by the NH1 injection rate. I came.
この方法によれば、まず基本的には、ＥＣｏｏ□濃度は
、負荷（燃料量）と一対に対応させたプログラム制御（
第６図１０４）を組んでいた。従って多種類の石炭を同
一火炉で燃焼させる場合は、ＮＯｘ、灰中未燃分ともに
多く生ずる高燃料比炭をベースとして高めにＥＣ０ｏ２
設定されていた。According to this method, the ECoo□ concentration is basically controlled by a program that corresponds to the load (fuel amount).
Figure 6 104) was assembled. Therefore, when burning many types of coal in the same furnace, use a high fuel ratio coal that produces a lot of NOx and unburned matter in the ash as a base, and use a higher EC0o2.
It was set.
そして、燃料比が低い、つまり燃えやすく且つＮＯｘも
下げやすい低燃料化炭を燃焼させる時も。Also, when burning low-density coal that has a low fuel ratio, that is, it burns easily and reduces NOx.
効率を上げ所内動力率を下げる為に効果的なＥＣ０ｏ２
を下げて運転することは行われないままであった・
〔発明が解決しようとする問題点〕
上記した従来技術は、多種類の石炭を同一火炉で使用し
て高効率運転しようとする観点から考えた時、未燃分が
低く且つＮＯｘも下げやすい低揮発分炭（第４図参照）
について、排ガス損失が低下でき所内率も下げられる手
段として有効なＥＣｏＯ２濃度を下げた運転をおこなう
ことが、出来ない、従って、これらの石炭ではＥ Ｃｏ
Ｏ，濃度を下げることによって更にＮＯｘが低下でき
ＮＨ。EC0o2 is effective for increasing efficiency and lowering the power rate within the station.
[Problem to be solved by the invention] The above-mentioned conventional technology was developed from the viewpoint of high efficiency operation by using multiple types of coal in the same furnace. When you think about it, it is a low volatile coal that has low unburned content and is easy to reduce NOx (see Figure 4).
For these coals, it is not possible to operate with a lower ECoO2 concentration, which is an effective means of reducing exhaust gas loss and lowering the in-plant rate.
By lowering the concentration of O and NH, NOx can be further reduced.
注入率が低下できるにもかかわらず、ＥＣｏ○２濃度を
下げる運転がなされにくい為に、ＮＨ，も努力して下げ
る事がなく従って高効率運転されてなかった。Even though the injection rate can be lowered, it is difficult to operate to lower the ECo○2 concentration, so no effort is made to lower the NH concentration, and therefore high efficiency operation is not achieved.
このような運転の方法は、我国のように資源のない国で
は危険分散の点から数多くの産炭地からの石炭を輸入し
同一火炉へ燃焼させていると同時に、火炉が大容量炉と
なっており、さらに鉱物船の大きさとの関連で炭種が変
わる度合いは増しているほか、効率向上の要求は日増し
に強くなっている等から、問題があった。In countries like Japan, which lack resources, this method of operation imports coal from many coal producing areas and burns it in the same furnace in order to spread the risk. In addition, the type of coal is changing more and more depending on the size of the mineral carrier, and demands for improved efficiency are becoming stronger day by day, creating problems.
本発明は、上記した問題点を解決する為に、まず、入荷
したバンカに入って来た石炭性状のうち燃料比と燃料中
Ｎ分を、制御上のインプット項目として電算機へ入力す
る。一方、電算機には、当該火炉または、類似炉で得ら
れたデータから、（ａ）Ｎ分に対するＮ０Ｘ（第２図参
照）補正率、（ｂ）ＥＣｏＯ□濃度に対するＮＯｘと未
燃分（第４図参照） 、 （ｃ）燃料比に対するＮ０ｘ
（第７図参照）、および未燃分（第３図参照） （ｄ）
ＮＨａ注入率と脱硝率の関連（従来から既知）、を記憶
させておく。煙突出口ＮＯｘ値（地元の規制値）は制御
目標値として事前に把握されているので、該ＮＯｘ値の
範囲内において、Ｅ Ｃｏ Ｏを濃度に対する排ガス損
失及び所内率のコスト計算、Ｅ Ｃｏ Ｏ，濃度に対し
未燃分増加による損失コスト（未燃分コスト）計算、及
び前記ＮＯｘ値によって決まるＮＨ。In order to solve the above-mentioned problems, the present invention first inputs the fuel ratio and the N content in the fuel from among the properties of the coal that has arrived in the bunker as input items for control. On the other hand, the computer contains data obtained from the furnace concerned or a similar furnace, including (a) correction factor for NOX (see Figure 2) for N content, (b) correction factor for NOx and unburned content (refer to Figure 2) for ECoO□ concentration. (See Figure 4), (c) NOx versus fuel ratio
(see Figure 7), and unburned content (see Figure 3) (d)
The relationship between the NHa injection rate and the denitrification rate (known in the past) is memorized. Since the chimney outlet NOx value (local regulation value) is known in advance as a control target value, within the range of the NOx value, E Co O is calculated based on the concentration of exhaust gas loss and the cost of the station rate, E Co O, Loss cost (unburnt cost) calculated due to increase in unburned content with respect to concentration, and NH determined by the NOx value.
注入率に対するコスト計算を計算させる。そして計算結
果にもとづいて効率が最大（損失が最小）となるＥＣｏ
ｏ□濃度を見出し、従来のＥＣｏｏ□濃度プログラムに
、バイアス率を打出すと共に自動時に制御信号としてア
ウトプットする。以上のよう゛な制御は、たとえば、イ
ンテリジェント型Ｎ。Calculate cost for injection rate. Based on the calculation results, ECo has the maximum efficiency (minimum loss).
The o□ concentration is found, the bias rate is outputted to the conventional ECoo□ concentration program, and it is output as a control signal during automatic operation. The above-mentioned control is, for example, intelligent type N.
Ｘ制御装置によっておこなう。This is done by the X control device.
微粉炭燃焼炉においてＥ Ｃｏ Ｏｘ濃度を変化させた
時のＮＯｘ、灰中未燃分の挙動は第４図に示されている
。まず、ＮＯｘについて取り上げると。Figure 4 shows the behavior of NOx and unburned matter in the ash when the E Co Ox concentration is changed in a pulverized coal combustion furnace. First, let's talk about NOx.
二段燃焼率を一定とするとＥＣｏＯ□濃度が低くなった
場合、バーナ下流において発生したＮＯｘは空気不足の
雰囲気下で還元作用を受け、その一部が安定なＮ２に還
元され、ＮＯｘ値は低下する。If the two-stage combustion rate is held constant and the ECoO□ concentration becomes low, the NOx generated downstream of the burner will undergo a reduction action in an atmosphere lacking air, and a portion of it will be reduced to stable N2, resulting in a decrease in the NOx value. do.
ＮＯｘ低下はＤ ａ−ＮＯｘにおけるＮＨ，注入牢を下
げる効果をもつぼか空気予熱器の酸性硫安の発生を軽減
しＡ／Ｈ詰りを軽減させる。次に、未燃分はＥＣｏＯ□
濃度が低くなった場合、酸欠によって燃焼率が低下し、
この為、灰中未燃分中の未燃カーボンにはたとえば尚８
，０ＯＯＫｃａＱ／−の発熱量を有しており、未燃損失
は燃料損失で増加する。The reduction in NOx reduces the generation of acidic ammonium sulfate in the air preheater, which has the effect of lowering NH in Da-NOx and the injection chamber, thereby reducing A/H clogging. Next, the unburned matter is ECoO□
When the concentration becomes low, the combustion rate decreases due to lack of oxygen,
For this reason, the unburned carbon in the unburned matter in the ash contains, for example, 8
,0OOKcaQ/-, and unburned loss increases due to fuel loss.
一方、空気予熱器出ロガス温度は一般的に低負荷時でも
１３０℃、高負荷時は１４５℃程度をバランスする様設
計される為、ＥＣｏＯ□濃度が高いほど、排ガス量が増
加し、乾き排ガス損失の他、空気中湿分損失が増加する
と共に、空気や排ガスを移送する為の強圧通風機および
誘引通風機６の動力は、大きくなる。On the other hand, the air preheater output log gas temperature is generally designed to balance 130℃ even at low load and 145℃ at high load, so the higher the ECoO□ concentration, the more the exhaust gas amount increases, and the dry exhaust gas In addition to the loss, the moisture loss in the air increases, and the power of the high-pressure ventilation fan and induced ventilation fan 6 for transferring air and exhaust gas increases.
これらは、極めて複雑に多変数で関与しており、最適化
を図るには、多変数の因子を総合的に判断して行う必要
があり、多種類の石炭で且つ大容量燃焼炉で炭種が頻繁
に変化する為、たとえばインテリジェント型ＮＯｘ制御
装置を使った制御をおこなえば、コスト面の最適化が図
れる。These factors are extremely complex and involved in many variables, and in order to achieve optimization, it is necessary to comprehensively judge the factors of many variables. Since the amount changes frequently, cost optimization can be achieved by controlling the amount using an intelligent NOx control device, for example.
具体的な実施例を第１図にもとづいて説明する。 A specific example will be described based on FIG.
図において右側の制御回路は、従来技術と同一機能同一
作用をもつ（第６図左側参考）。図中の左側に示される
様に、ＥＣｏ○２制御回路に、事前にインテリジェント
型ＮＯｘ制御装置を付加させ、次に予知出来る石炭中の
燃料比及びＮ分をインプットする（２０１）。この燃料
比及びＮ分は、連続分析装置による結果として信号で入
力してもよいし、人手によって入力してもよい。ＮＯｘ
制御装置内では、例えば、燃料比に対するＮＯｘ及び未
燃分が、データファイルまたは計算式（負荷静定特性）
で予測される（２０２）、その後、ＮＯｘは燃料中Ｎ分
によってＮ分補正が、かけられる（２０３）、このＮＯ
ｘ値によって、Ｄ ｅ −Ｎ Ｏｘ特性をもとにＮＨ３
注入率が決定出来る（２０４）。該注入率におけるＮ
Ｏｘ値が地元の規制値の制限内か否かが判断される（２
０５）、制限内であれば、次いで、ＮＨ３注入率コスト
、排ガス損失及び所内率（２０６）さらに未燃分コスト
（２０７）がＮＯｘ制限制限Ｃｏ Ｏ，内で繰返し計算
されて、損失ミニマム値が選定される（２０８）。これ
をもとにして、従来技術で採用している０２プロ゛グラ
ム制御設定値にバイアス率を加算して（２０９）、０２
濃度を求めるものである。勿論ＥＣ００２濃度には火炉
安全上に必要なミニマム値は下限として与えられている
。The control circuit on the right side of the figure has the same function and effect as the conventional technology (see left side of Figure 6). As shown on the left side of the figure, an intelligent NOx control device is added to the ECo○2 control circuit in advance, and then the predictable fuel ratio and N content in the coal are input (201). The fuel ratio and N minute may be input as a signal as a result of a continuous analyzer, or may be input manually. NOx
In the control device, for example, the NOx and unburned components relative to the fuel ratio are stored in a data file or calculation formula (load static characteristic).
(202), NOx is then corrected by N in the fuel (203).
Depending on the x value, NH3 is
The injection rate can be determined (204). N at the injection rate
It is determined whether the Ox value is within the limits of local regulations (2
05), if it is within the limit, then the NH3 injection rate cost, exhaust gas loss and station rate (206), and unburned fuel cost (207) are repeatedly calculated within the NOx limit Co O, and the minimum loss value is determined. It is selected (208). Based on this, the bias rate is added to the 02 program control setting value adopted in the conventional technology (209), and the 02
This is to find the concentration. Of course, the minimum value necessary for furnace safety is given as a lower limit for the EC002 concentration.
このようにインテリジェント型ＮＯｘ制御装置を用いて
ＮＯｘ制御した場合には、（ＮＯｘ特性、未燃分特性に
若干余裕がないと不可能であるが）負荷に対するＥＣｏ
Ｏ□濃度設定値は、燃料が異ることにより変化して、運
転員にはまぎられしい面はあるが、Ｅ Ｃｏ Ｏ，濃度
のベースとなっている高燃料比炭以外の石炭が入荷した
時は、低Ｅｃ００２濃度化が可能となり、従って排ガス
損失、ＮＨ３注入率が低下して、高効率運転が可能とな
るホカ、ＳＯ２→ＳＯ１への転化率やり−クＮＨ，が減
るので、Ｄｅ−ＮＯｘ装置を設置した時の問題として残
るＮＨ，（Ｈ）ＳＯ，（酸性硫安）にょるＡ／Ｈの詰り
、すなわちドラフトロス上昇が軽減出来る。In this way, when NOx is controlled using an intelligent NOx control device, the ECo
The O □ concentration setting value changes depending on the fuel, and although it can be confusing for operators, it is possible that coal other than the high fuel ratio coal that is the base of the E Co O concentration has arrived. At the same time, it becomes possible to lower the Ec002 concentration, thereby reducing the exhaust gas loss and NH3 injection rate, enabling high efficiency operation, and reducing the conversion rate from SO2 to SO1 and reducing the De- A/H clogging due to NH, (H)SO, (acidic ammonium sulfate), that is, increased draft loss, which remains a problem when installing a NOx device, can be reduced.
また、ＥＣｏ○２濃度低下に伴って懸念される排ガス量
低下での対流伝熱部の特性すなわち１例えば再熱蒸気温
度特性、未達の問題は、排ガスのパラレルダンパ制御、
または／および排ガス再循環ガス量制御によっても対応
が可能となるので問題はない。In addition, the problem of not achieving the characteristics of the convection heat transfer section due to the decrease in exhaust gas volume, which is a concern due to the decrease in ECo○2 concentration, 1, for example, the reheat steam temperature characteristics, is due to the parallel damper control of the exhaust gas,
Or/and this can also be handled by controlling the amount of exhaust gas recirculation, so there is no problem.
煙突出口にてのＮＯｘ濃度は６０ｐｐｍとされて。The NOx concentration at the chimney outlet is assumed to be 60 ppm.
ＮＯｘダンパはほぼ全開または一定開度で運転されＤ
ｅ −Ｎ ＯｘへＮＨ，注入率が主制御因子と考えられ
ている現在において今後、ＥＣ０ｏ２でＮＯｘ制御する
ことを提案できるのは、ＮＲバーナと云った高効率低Ｎ
Ｏｘバーナが開発され、このバーナを生かし、更に高効
率化するにはどうすればよいかという間にある程度答え
られたものである。The NOx damper is operated almost fully open or at a constant opening.D
At present, the injection rate of NH to e-N Ox is considered to be the main control factor, but in the future, we can propose NOx control with EC0o2 using a high-efficiency, low-N
With the development of the Ox burner, the question of how to make the most of this burner and make it even more efficient was answered to some extent.
本発明によれば、
（１）多種類の石炭のうち、ＥＣｏ０２濃度（ＮＯｘ、
未燃分）設定のベースとなった高燃料比炭以外の燃料が
入荷した時、低ＥＣｏＯ□濃度運転が可能であるので、
最も効率の高い運用が可能となる。According to the present invention, (1) Among various types of coal, ECo02 concentration (NOx,
When fuel other than high fuel ratio coal, which was the basis for setting (unburned content), arrives, low ECoO□ concentration operation is possible.
This enables the most efficient operation.
（２） Ｅ Ｃｏ Ｏ，濃度低下に伴ない、酸性硫安
によるＡ／Ｈ詰りか軽減出来、ランニングコストの他、
メインテナンスフィの軽減が可能となる。(2) E Co O, as the concentration decreases, A/H clogging due to acidic ammonium sulfate can be reduced, and in addition to running costs,
It is possible to reduce maintenance fees.
（３） 多種炭に対し、ワンマンコントロールを行う
に当り最適Ｅ Ｃｏ Ｏ２濃度を、制御装置内で算出出
来るので、省力化したプラントに最適である。(3) When performing one-man control for various types of coal, the optimum E Co O2 concentration can be calculated within the control device, making it ideal for labor-saving plants.
第１図は本発明になるインテリジェント制御装置をあら
れす図、第２図はバーナ空気比、燃料比がほぼ一定で、
Ｎ分が変化した時のＮＯｘ特性図、第３図は０□一定、
燃料比変化時の未燃分特性図、第４図は０２変化時の未
燃分及びＮＯｘの特性図、第５図は従来技術になるボイ
ラシステム例をあられす図、第６図は従来技術になる燃
焼空気量制御システムをあられす図、第７図は燃料中Ｎ
分が、はぼ同一で、燃料比が変化した時のＮＯｘ特性図
である。
雇、Ｐｒ冗
Ｎ今含有宇（ｄＱｆ％）
第４図
ＥＣＯ０２％Fig. 1 shows the intelligent control device according to the present invention, and Fig. 2 shows the burner air ratio and fuel ratio being almost constant.
NOx characteristic diagram when N minute changes, Figure 3 shows 0□ constant,
Fig. 4 is a characteristic diagram of unburned content and NOx when the fuel ratio changes. Fig. 5 is a diagram showing an example of a boiler system according to the conventional technology. Fig. 6 is a diagram of the conventional technology. Fig. 7 shows the combustion air amount control system.
It is a NOx characteristic diagram when the fuel ratio is changed while the fuel ratio is almost the same. Employed, Pr dQf% (dQf%) Figure 4 ECO02%
Claims (1)
が異なる多種類の石炭を同一火炉において燃焼させる燃
焼炉において、煙道排ガス中のＮＯｘを規制値以内に制
御する制御回路に、事前に今から使用する石炭の燃料比
および燃料中Ｎ分をインプットすることにより、負荷静
定特性にもとづいた効率計算を排ガス中のＯ＿２（ＥＣ
ｏＯ＿２）濃度、灰中の未燃分、ＮＨ＿３注入量の因子
から計算させ、効率が最大となるＥＣｏＯ＿２濃度を見
い出してアウトプットし、該濃度にもとづいて自動的に
燃焼用空気量を制御し、よってＮＯｘを制御する制御回
路を設定することを特徴とした高効率ＮＯｘ制御方法。(1) A control circuit that controls NOx in flue gas within the regulation value in a combustion furnace in which multiple types of coal with different fuel ratios (fixed carbon/volatile matter) and N content in the fuel are burned in the same furnace. By inputting the fuel ratio of the coal to be used and the N content in the fuel in advance, efficiency calculations based on the static load characteristics can be performed using O_2 (EC
oO_2) Calculate from the factors of concentration, unburned content in ash, and NH_3 injection amount, find and output the ECoO_2 concentration that maximizes efficiency, and automatically control the amount of combustion air based on this concentration, Therefore, a highly efficient NOx control method is characterized in that a control circuit for controlling NOx is set.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4210087A JPH0781151B2 (en) | 1987-02-25 | 1987-02-25 | High efficiency NOx control method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4210087A JPH0781151B2 (en) | 1987-02-25 | 1987-02-25 | High efficiency NOx control method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63207894A true JPS63207894A (en) | 1988-08-29 |
| JPH0781151B2 JPH0781151B2 (en) | 1995-08-30 |
Family
ID=12626566
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4210087A Expired - Fee Related JPH0781151B2 (en) | 1987-02-25 | 1987-02-25 | High efficiency NOx control method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0781151B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009150619A (en) * | 2007-12-21 | 2009-07-09 | Babcock Hitachi Kk | Boiler device |
| EP2687495A4 (en) * | 2011-02-25 | 2018-03-28 | Mitsubishi Materials Corporation | Method for controlling nox concentration of discharge gas in combustion equipment using dust coal |
| JP2018204843A (en) * | 2017-06-01 | 2018-12-27 | 三菱日立パワーシステムズ株式会社 | Coal burning boiler controller |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3790504B2 (en) * | 2002-08-09 | 2006-06-28 | 三菱重工業株式会社 | Pulverized coal combustion system |
-
1987
- 1987-02-25 JP JP4210087A patent/JPH0781151B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009150619A (en) * | 2007-12-21 | 2009-07-09 | Babcock Hitachi Kk | Boiler device |
| EP2687495A4 (en) * | 2011-02-25 | 2018-03-28 | Mitsubishi Materials Corporation | Method for controlling nox concentration of discharge gas in combustion equipment using dust coal |
| JP2018204843A (en) * | 2017-06-01 | 2018-12-27 | 三菱日立パワーシステムズ株式会社 | Coal burning boiler controller |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0781151B2 (en) | 1995-08-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106247368B (en) | A kind of industrial coal powder boiler flue gas recirculation low nitrogen burning method and system | |
| CN203595119U (en) | Device capable of reducing nitric oxides in flue gas product of circulating fluidized bed boiler | |
| CN201582846U (en) | Combustion control system of lignite unit | |
| CN204611743U (en) | Boiler controller system | |
| CN103574578A (en) | Anti-implosion control method for boiler furnace and smoke system in 1045 MW thermal power generating unit by adopting three-in-one induced draft fan | |
| CN109578994B (en) | Low NOx combustion system of flue gas recirculation and hierarchical gasification of superfine buggy | |
| CN108105794A (en) | A kind of SCR denitration system inlet flue gas temperature adaptive regulation method | |
| CN208382139U (en) | A kind of flue gas recirculation system of low nitrogen burning | |
| CN204534555U (en) | A kind of flue gas recirculation device for reducing NO_x formation | |
| CN204395745U (en) | A kind of clean exhaust system for fluidized-bed combustion boiler | |
| JPS63207894A (en) | Control of nox in high efficiency | |
| US9429319B2 (en) | Boiler combustion system and operation method therefor | |
| CN106224948A (en) | A kind of self adaptation CFBB control method | |
| JPH0617741B2 (en) | Control method of primary air temperature at pulverized coal machine outlet for boiler | |
| JPS58182004A (en) | Combustion method for low nitrogen oxide in pulverized coal | |
| CN106090893A (en) | A kind of high performance clean burning method of coal-burning boiler | |
| CN218154187U (en) | SCR deNOx systems's gas temperature governing system | |
| JPS62276322A (en) | Nitrogen oxide reducing device | |
| CN104511234B (en) | A kind of clean exhaust system for fluidized-bed combustion boiler and method | |
| CN215637294U (en) | Hot air and flue gas composite recirculation system | |
| JP3544716B2 (en) | Method and apparatus for controlling ammonia injection amount in denitration apparatus | |
| JP2612284B2 (en) | Combustion equipment | |
| JPH0533906A (en) | Pulverized coal combustion method of boiler | |
| CN211526413U (en) | Coal-fired boiler | |
| CN118375907A (en) | Device for adjusting ammonia escape of flue gas of circulating fluidized bed boiler and working method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |