JPH09871A - Ammonia injection amount control device for a plurality of exhaust gas treatment systems - Google Patents
Ammonia injection amount control device for a plurality of exhaust gas treatment systemsInfo
- Publication number
- JPH09871A JPH09871A JP7156407A JP15640795A JPH09871A JP H09871 A JPH09871 A JP H09871A JP 7156407 A JP7156407 A JP 7156407A JP 15640795 A JP15640795 A JP 15640795A JP H09871 A JPH09871 A JP H09871A
- Authority
- JP
- Japan
- Prior art keywords
- nox concentration
- exhaust gas
- outlet
- ammonia
- outlet nox
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
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Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、複数の排ガス処理系統
へのアンモニア注入量制御装置に係り、特にアンモニア
ガスを還元剤とする脱硝装置へのアンモニア注入量制御
装置であって、2系統以上の排ガス脱硝反応装置を有す
る排ガス処理系統へのアンモニア注入量制御装置に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ammonia injection amount control device for a plurality of exhaust gas treatment systems, and more particularly to an ammonia injection amount control device for a denitration device using ammonia gas as a reducing agent. The present invention relates to an ammonia injection amount control device for an exhaust gas treatment system having an exhaust gas denitration reactor.
【0002】[0002]
【従来の技術】図4にボイラ排ガス系がA、Bの2系統
を有する場合の煙道系統図を示す。ボイラ1より排出さ
れた排ガスはA系、B系脱硝反応器8、9へ流入する。
脱硝装置にて処理された排ガスは空気予熱器14、15
にて熱回収され、その後必要に応じて除塵、脱硫が行な
われた後、煙突17から排出される。脱硝装置用アンモ
ニアの注入量制御は、通常脱硝装置出口NOx濃度が一
定となるようコントロールされている。具体的には脱硝
装置入口に設けられたNOx計2、3および脱硝装置出
口に設けられたNOx計33、34のNOx濃度検出信
号を用いアンモニア流量調節弁4、6にて行なわれる。
一般に図8に示すように燃料燃焼バーナ33、34を缶
前側と缶後側にそれぞれ設けて対向燃焼方式をとるボイ
ラにおいては、火炉1a内において、バーナの燃焼状態
は缶前と缶後で異なっており、燃焼状態の異なった燃焼
排ガスが十分に混合されることなく、図8に示すように
そのままの状態で火炉出口から排出される傾向がある。2. Description of the Related Art FIG. 4 shows a flue system diagram when a boiler exhaust gas system has two systems A and B. The exhaust gas discharged from the boiler 1 flows into the A-type and B-type denitration reactors 8 and 9.
The exhaust gas treated by the denitration device is the air preheater 14, 15
The heat is recovered at 1, after which dust and desulfurization are carried out if necessary, and then discharged from the chimney 17. The injection amount control of ammonia for the denitration device is usually controlled so that the NOx concentration at the outlet of the denitration device becomes constant. Specifically, the NOx concentration detection signals of the NOx meters 2 and 3 provided at the inlet of the denitration device and the NOx concentration detection signals of the NOx meters 33 and 34 provided at the outlet of the denitration device are used to control the ammonia flow rate control valves 4 and 6.
Generally, as shown in FIG. 8, in a boiler that employs the opposed combustion method by providing fuel combustion burners 33 and 34 on the front side and the rear side of the can, respectively, in the furnace 1a, the combustion state of the burner differs between before and after the can. In other words, the combustion exhaust gases in different combustion states tend not to be sufficiently mixed and to be discharged from the furnace outlet as they are as shown in FIG.
【0003】したがって、火炉出口に燃焼排ガス煙道を
A、Bの2系統として、各系統ごとに脱硝反応器を設け
て排ガス中のNOxを除去する場合、A、B各系統の入
口NOx濃度が同一でないので、各系統ごとに脱硝装置
の制御装置を設け、独立に制御している。なお、排ガス
流量は各系統にダンパー、脱硝装置、空気予熱器が設け
られており、ガス流量はA、B同一ではなく、多少の偏
差があるが、一般には、排ガス流量の1/2づつが流れ
ていると仮定して処理している。Therefore, when the NOx concentration in the exhaust gas is removed by providing a NOx removal reactor for each system with the combustion exhaust gas flue as the two systems A and B at the furnace outlet, the inlet NOx concentration of each system A, B Since they are not the same, a denitration device control device is provided for each system to control them independently. It should be noted that the exhaust gas flow rate is provided with a damper, a denitration device, and an air preheater in each system, and the gas flow rate is not the same as A and B, but there is some deviation, but in general, 1/2 of the exhaust gas flow rate is used. It is processed assuming that it is flowing.
【0004】実際のアンモニア注入量の制御系統の一例
を図5に示す。本制御系統は図4に対応するもので、A
系、B系は各々独立に構成されている。アンモニア注入
量制御の考え方は、負荷信号18をベースとして求めら
れた処理ガス量25に、入口NOx濃度信号19とアナ
ログメモリ20より出力される出口NOx濃度設定信号
の偏差を入口NOx濃度で割算した値をベースとして求
められた必要アンモニア注入モル比信号26を出口NO
x濃度設定値20aと実測された出口NOx濃度21の
偏差により前記した必要モル比に補正をかける方法であ
る。このようにして求められたアンモニア注入モル比信
号26aと処理ガス量25を乗じることにより要求アン
モニア量28を求め、アンモニア注入流量調節弁31に
て注入されるアンモニア量は実測されたアンモニア流量
24との偏差をなくすよう調節計30にてコントロール
される。FIG. 5 shows an example of a control system for the actual ammonia injection amount. This control system corresponds to Fig. 4.
The system and the system B are independently configured. The concept of the ammonia injection amount control is that the difference between the inlet NOx concentration signal 19 and the outlet NOx concentration setting signal output from the analog memory 20 is divided by the inlet NOx concentration by the processing gas amount 25 obtained based on the load signal 18. The required ammonia injection molar ratio signal 26 obtained on the basis of
This is a method of correcting the required molar ratio by the deviation between the x concentration set value 20a and the measured outlet NOx concentration 21. The required ammonia amount 28 is obtained by multiplying the ammonia injection molar ratio signal 26a thus obtained and the processing gas amount 25, and the ammonia amount injected by the ammonia injection flow rate control valve 31 is the measured ammonia flow rate 24. It is controlled by the controller 30 so as to eliminate the deviation.
【0005】[0005]
【発明が解決しようとする課題】ボイラから排出される
NOxの排出規制の監視は、通常図4に示す煙突入口N
Ox濃度計16にて行なわれる。これに対し実際の運転
操作に際しては、A系、B系各々出口NOx設定値を加
減し、脱硝装置出口NOx濃度計33、34にてアンモ
ニア注入量をコントロールすることにより煙突入口NO
x濃度が規制値より若干低い値となるように行なわれ
る。Monitoring of NOx emission regulation from the boiler is usually performed by monitoring the chimney inlet N shown in FIG.
It is performed by the Ox densitometer 16. On the other hand, at the time of actual operation, the NOx set values for the A and B systems are adjusted, and the NOx concentration meter 33, 34 for denitration equipment controls the amount of ammonia injection to control the chimney inlet NO.
It is performed so that the x concentration is slightly lower than the regulation value.
【0006】しかし、脱硝装置出口NOx設定値がA、
B系2つの設定値を持つため、煙突入口NOx値を目標
値に合わせることが難しい。そのため運用上安全サイド
である目標値より低目のNOx濃度設定値としていた
(これは結果として過剰アンモニアの注入となる)。さ
らに脱硝装置出口にNOx濃度計としてA、B系に各々
1台(合計2台)設けるため、これら分析計器の保守点
検手数が増加する等の問題があった。そのため図6に示
すごとく脱硝装置出口NOx濃度計13をA、B系兼用
とし、両系統から排ガスを等量づつサンプリングして混
合した両系統の平均NOx濃度によりアンモニア注入量
の制御が行なわれたが、A、B系入口NOx濃度の測定
値がボイラ負荷によって異なる場合等にA、B系の出口
NOx濃度値にアンバランスが生じる結果となり(図7
参照)、過大な量のアンモニアを注入された側で未反応
アンモニア濃度が高くなること、またA、B系の総合脱
硝効率もアンモニア注入量に対してみた場合低下する等
の問題が生じていた。However, the NOx setting value at the outlet of the denitration device is A,
Since the B system has two set values, it is difficult to match the NOx value of the chimney inlet to the target value. Therefore, the NOx concentration set value lower than the target value on the safe side in operation was set (this results in injection of excess ammonia). Further, since one NOx concentration meter is provided for each of the A and B systems (two in total) at the outlet of the denitration device, there has been a problem that the number of maintenance and inspections for these analyzers increases. Therefore, as shown in FIG. 6, the NOx concentration meter 13 at the outlet of the denitration device is used for both A and B systems, and the amount of ammonia injection is controlled by the average NOx concentration of both systems in which exhaust gas from both systems is sampled in equal amounts and mixed. However, when the measured values of the NOx concentration at the inlets of the A and B systems differ depending on the load of the boiler, etc., the NOx concentration values at the outlets of the A and B systems become unbalanced (Fig. 7).
However, there was a problem that the unreacted ammonia concentration increased on the side where an excessive amount of ammonia was injected, and the overall denitration efficiency of the A and B systems also decreased when viewed from the ammonia injection amount. .
【0007】[0007]
【課題を解決するための手段】上記問題点を解決するた
め本願で特許請求する発明は以下のとおりである。 (1)排ガス発生源からの排ガスを処理する排ガス煙道
を2系統以上設け、各系統にアンモニア注入装置と脱硝
反応器および該反応器入口NOx濃度計を設けたものに
おいて、各系統兼用として設けた脱硝反応器出口NOx
濃度計と、各系統の脱硝反応器下流側排ガスをそれぞれ
サンプリングする手段と、該手段によりサンプリングさ
れた全系統の排ガスの混合体を前記出口NOx濃度計に
供給して平均出口NOx濃度を検出する手段と、各系統
の入口NOx濃度計の検出値、出口NOx濃度設定器の
設定値および前記平均出口NOx濃度とに基づき各系統
それぞれの注入アンモニアモル比を算出する手段と、注
入アンモニアモル比と排ガス流量とに基づき各系統の注
入アンモニア量を制御する手段と、前記排ガスサンプリ
ング手段に設けた切換手段により、各系統ごとの出口排
ガスを前記出口NOx濃度計に供給して各系統ごとの出
口NOx濃度を検出する手段と、この検出値と前記出口
NOx濃度設定値の偏差に基づき前記注入アンモニアモ
ル比を補正する手段とを設けたことを特徴とする複数の
排ガス処理系統へのアンモニア注入量制御装置。The invention claimed in the present application for solving the above problems is as follows. (1) Two or more exhaust gas flues for treating exhaust gas from an exhaust gas source are provided, and each system is provided with an ammonia injection device, a denitration reactor, and a NOx concentration meter at the reactor inlet DeNOx reactor outlet NOx
A concentration meter, a means for sampling exhaust gas on the downstream side of each system of the denitration reactor, and a mixture of exhaust gases of all the systems sampled by the means are supplied to the outlet NOx concentration meter to detect the average outlet NOx concentration. Means, means for calculating the injected ammonia molar ratio of each system based on the detected value of the inlet NOx concentration meter of each system, the set value of the outlet NOx concentration setting device, and the average outlet NOx concentration, and the injected ammonia molar ratio, The outlet NOx for each system is supplied to the outlet NOx concentration meter by the outlet exhaust gas for each system by means for controlling the amount of injected ammonia in each system based on the exhaust gas flow rate and the switching means provided in the exhaust gas sampling means. A means for detecting the concentration and a means for correcting the injected ammonia molar ratio based on the deviation between the detected value and the outlet NOx concentration set value. Ammonia injection quantity control device to a plurality of exhaust gas treatment system characterized in that a and.
【0008】(2)燃焼装置からの排ガスを処理する排
ガス煙道を複数系統設け、各系統にアンモニア注入装
置、脱硝反応器、該反応器入口NOx濃度計、出口NO
x濃度設定器および反応器下流の排ガスサンプリング手
段とを設けたものにおいて、各系統兼用として設けた脱
硝反応器出口NOx濃度計と、前記排ガスサンプリング
管よりサンプリングした全系統の混合排ガスに基づき前
記出口NOx濃度計により平均出口NOx濃度を検出す
る手段と、前記入口NOx濃度計、平均出口NOx濃度
検出手段および出口NOx濃度設定器の出力値に基づき
各系統への注入アンモニアモル比を算出する手段と、常
時に、この注入アンモニアモル比と各系統の排ガス流量
とに基づき各系統へのアンモニア注入量を制御する手段
を設けるとともに、所定時間ごとに、前記排ガスサンプ
リング手段に接続した切換手段により各系統ごとにサン
プリングした排ガスに基づき前記出口NOx濃度計によ
り各系統ごとの出口NOx濃度を検出する手段と、この
検出値と前記出口NOx濃度設定器の設定値により前記
注入アンモニアモル比を補正する手段とを設けたことを
特徴とする複数の排ガス処理系統へのアンモニア注入量
制御装置。(2) A plurality of exhaust gas flues for treating exhaust gas from the combustion device are provided, and each system has an ammonia injection device, a denitration reactor, a NOx concentration meter at the reactor inlet, and an outlet NO.
x concentration setting device and exhaust gas sampling means downstream of the reactor, the NOx concentration outlet NOx concentration meter provided for both systems and the outlet based on the mixed exhaust gas of all the systems sampled from the exhaust gas sampling pipe A means for detecting the average outlet NOx concentration by the NOx concentration meter, and a means for calculating the injection ammonia molar ratio to each system based on the output values of the inlet NOx concentration meter, the average outlet NOx concentration detecting means and the outlet NOx concentration setting device. , And means for controlling the amount of ammonia injected into each system on the basis of this injected ammonia molar ratio and the exhaust gas flow rate of each system at all times, and each system by a switching means connected to the exhaust gas sampling means every predetermined time. Based on the exhaust gas sampled for each Ammonia injection amount into a plurality of exhaust gas treatment systems, characterized by including means for detecting NOx concentration and means for correcting the injected ammonia molar ratio based on the detected value and the setting value of the outlet NOx concentration setting device. Control device.
【0009】(3)対向燃焼式ボイラからの燃焼排ガス
煙道を複数系統設け、各系統にアンモニア注入装置、脱
硝反応器、該反応器入口NOx濃度計、出口NOx濃度
設定器および前記反応器下流の排ガスサンプリング管と
を設けたものにおいて、各系統兼用として設けた1台の
出口NOx濃度計と、各系統排ガスが合流した煙突入口
煙道から採取した排ガスに基づき前記NOx濃度計によ
り平均出口NOx濃度を検出する手段と、前記入口NO
x濃度計、出口NOx濃度設定器および平均出口NOx
濃度検出手段の出力値に基づき各系統への注入アンモニ
アモル比を算出する手段と、この注入アンモニアモル比
と各系統の排ガス流量に基づき各系統へのアンモニア注
入量を制御する手段と、所定時間ごとに前記各系統の反
応器下流の排ガスサンプリング管に接続した切換手段に
より各系統ごとにサンプリングした排ガスに基づき前記
出口NOx濃度計により各系統ごとの出口NOx濃度を
検出する手段と、この検出値と前記出口NOx濃度設定
器の設定値とにより前記注入アンモニアモルを補正する
手段を設けたことを特徴とする複数の排ガス処理系統へ
のアンモニア注入量制御装置。(3) A plurality of combustion exhaust gas flues from the opposed combustion type boiler are provided, and an ammonia injection device, a denitration reactor, a NOx concentration meter at the inlet of the reactor, an NOx concentration outlet at the outlet, and the downstream of the reactor are provided in each system. Of the exhaust gas sampling pipe of the above system, one outlet NOx concentration meter provided for each system and the average outlet NOx concentration measured by the NOx concentration meter based on the exhaust gas collected from the chimney inlet flue where each system exhaust gas merges. Means for detecting concentration and the inlet NO
x concentration meter, outlet NOx concentration setting device and average outlet NOx
Means for calculating the injection ammonia molar ratio to each system based on the output value of the concentration detection means, means for controlling the ammonia injection amount to each system based on this injection ammonia molar ratio and the exhaust gas flow rate of each system, and a predetermined time Means for detecting the outlet NOx concentration for each system by the outlet NOx concentration meter based on the exhaust gas sampled for each system by the switching means connected to the exhaust gas sampling pipe downstream of the reactor for each system, and the detected value An ammonia injection amount control device for a plurality of exhaust gas treatment systems, characterized in that means for correcting the injected ammonia moles is provided based on the set value of the outlet NOx concentration setting device.
【0010】[0010]
【作用】脱硝装置出口NOx濃度計用のガスサンプリン
グ管はA、B系各々から取出すようにし、途中に切替弁
を設け、(1)A、B系両方からサンプリングし、A、
B系平均出口NOx濃度値を測定する手段、(2)A系
のみの出口NOx濃度を測定する手段、(3)B系のみ
の出口NOx濃度を測定する手段を持つようにする。そ
して定期的にA、B系出口NOx濃度実測値と設定出口
NOx濃度値の偏差をなくす補正制御を行なうように
し、A、B系出口NOx濃度にバラツキが生じないよう
にする。The gas sampling pipe for the NOx concentration meter outlet of the denitration device is taken out from each of the A and B systems, and a switching valve is provided on the way to (1) sample from both the A and B systems.
A means for measuring the B system average outlet NOx concentration value, (2) a means for measuring the A system outlet NOx concentration, and (3) a means for measuring the B system outlet NOx concentration are provided. Then, the correction control is periodically performed to eliminate the deviation between the A / B system outlet NOx concentration actual value and the set outlet NOx concentration value so that the A / B system outlet NOx concentration does not vary.
【0011】なお、通常運用時は、A、B系平均値の出
口NOx濃度を設定出口NOx濃度に合わせる制御を行
なっているため、出口NOx濃度設定値は煙突入口NO
x濃度値とほぼ合致する(O2 %換算値で)ため運転操
作も簡単となる。During normal operation, control is performed to match the outlet NOx concentration of the A and B system average values to the set outlet NOx concentration, so the outlet NOx concentration set value is the chimney inlet NO.
Since it substantially matches the x concentration value (O 2 % conversion value), the driving operation becomes simple.
【0012】[0012]
【実施例】図1に本発明の一実施例である煙道系統図を
示す。従来技術と異なる点はA、B系の脱硝装置出口N
Ox計13を兼用形としNOx計用サンプリング配管1
0、11に切換弁12を設けることにより、A、B両系
の平均出口NOx濃度値を測定できることはむろんA
系、B系各々単独でも出口NOx濃度を測定できるよう
にする。FIG. 1 shows a flue system diagram of an embodiment of the present invention. The difference from the conventional technology is the outlet N of the A and B system denitration equipment.
Sampling pipe for NOx meter 1 with Ox meter 13 also used
Of course, it is possible to measure the average outlet NOx concentration values of both A and B systems by providing the switching valve 12 at 0 and 11.
The outlet NOx concentration should be able to be measured by each of the system and B system alone.
【0013】図2に本発明の一実施例であるアンモニア
流量調節弁の制御系統図を示す。従来技術と異なる点
は、(1)脱硝装置出口NOx濃度信号21はA、B系
の平均出口NOx濃度値を用いている。通常時のアンモ
ニア注入量コントロールはこの平均NOx濃度値を用い
て制御することとなる。しかし、このままの制御とする
と従来技術で述べたように脱硝装置出口にてA、B系で
アンバランスがでるため、(2)出口NOx濃度計13
を切換え使用し、A系単独の出口NOx濃度測定値2
2、B系単独の出口NOx濃度測定値23の信号を用い
てアンモニア注入モル比の補正を行なうようにした点で
ある。すなわち、A系単独のNOx濃度値22と出口N
Ox濃度設定値20aの偏差を用いて、前記したA、B
平均出口NOx濃度を用いたモル比補正値にさらに補正
を加えるようにしたものである。FIG. 2 shows a control system diagram of an ammonia flow rate control valve which is an embodiment of the present invention. The difference from the prior art is that (1) the NOx concentration signal 21 at the outlet of the denitration device uses the average outlet NOx concentration value of the A and B systems. The control of the ammonia injection amount at the normal time is performed by using this average NOx concentration value. However, if the control is performed as it is, an imbalance occurs in the A and B systems at the outlet of the denitration device as described in the prior art. Therefore, (2) the outlet NOx concentration meter 13
Switched to use the measured NOx concentration at the outlet of system A alone 2
2. The point is that the ammonia injection molar ratio is corrected using the signal of the outlet NOx concentration measured value 23 of the B system alone. That is, the NOx concentration value 22 of the A system alone and the outlet N
Using the deviation of the Ox concentration set value 20a, the above A, B
The correction is further applied to the molar ratio correction value using the average outlet NOx concentration.
【0014】本実施例の要点は所定時間ごとに出口NO
x濃度計を切替えA、B系各々の値を検出し、図3に示
したように各々の出口NOx濃度値が設定出口NOx濃
度値に合うようにモル比補正をかけるようにしたもので
ある。図2中に2点鎖線内にて示した制御回路がこれを
示している。なお、A、Bの平均NOx濃度値よりA、
B系各々の単独出口NOx濃度値に切替え前記した補正
を加えるピッチは例えばNOx濃度計13の自動較正の
タイミングに合わせ行なうこともできる。したがって次
のA、B系単独測定による補正値決定までは補正値はそ
のままホードされた状態で入力されることとなる。本方
法はボイラなどのプラントの運用条件により種々のパタ
ーンが考えられるため、そのつど変更してもよい。The main point of this embodiment is that the exit NO at every predetermined time.
The x concentration meter is switched and the respective values of the A and B systems are detected, and as shown in FIG. 3, the molar ratio correction is applied so that each outlet NOx concentration value matches the set outlet NOx concentration value. . This is indicated by the control circuit shown within the chain double-dashed line in FIG. From the average NOx concentration values of A and B, A,
The pitch at which the individual outlet NOx concentration values of the respective B systems are switched and the above-mentioned correction is applied can be made, for example, at the timing of automatic calibration of the NOx concentration meter 13. Therefore, the correction value is input as it is until the correction value is determined by the next independent measurement of the A and B systems. Since this method can have various patterns depending on the operating conditions of the plant such as the boiler, it may be changed each time.
【0015】図2において脱硝出口平均NOx濃度信号
21の代わりに、図1に示す煙突入口NOx濃度計16
の信号を用いてもよい。その場合も従来技術の項で述べ
たA、B系の脱硝出口NOx濃度のアンバランスの問題
は残るため、本実施例にて述べた脱硝出口NOx計を用
い、A、B系のアンバランスを是正することが必要とな
る。Instead of the denitration outlet average NOx concentration signal 21 in FIG. 2, the chimney inlet NOx concentration meter 16 shown in FIG.
Signal may be used. Even in that case, the problem of unbalance of the NOx concentration of NOx outlets of the A and B systems described in the section of the prior art remains. It is necessary to correct it.
【0016】また、図2では、A、B各系統の排ガス流
量をボイラ負荷信号から求める例を示したが、排ガス流
量は、この外にボイラへの燃焼用空気供給量から換算す
ることもでき、また実際にA、B各系統ごとに実測して
求めることも可能である。In addition, FIG. 2 shows an example in which the exhaust gas flow rate of each of the A and B systems is obtained from the boiler load signal, but the exhaust gas flow rate can be converted from the combustion air supply amount to the boiler. It is also possible to actually measure and obtain each of the A and B systems.
【0017】[0017]
【発明の効果】本発明を実施することにより、次の効果
が期待できる。 (1)脱硝装置出口NOx設定値が通常時は、A、B系
兼用となるため、出口NOx濃度設定値が煙突入口NO
x設定値と合致するための運転員による出口NOx濃度
の設定操作が簡単となる。 (2)従来技術に比べ脱硝出口NOx計の台数が減るた
め分析計器のメンテナンスが容易となり、また分析計器
代が安くなる。The following effects can be expected by implementing the present invention. (1) When the NOx setting value at the outlet of the denitration device is normal, the NOx concentration setting value at the outlet is the same as the A and B systems.
This simplifies the operation of setting the outlet NOx concentration by the operator in order to match the x set value. (2) Since the number of NOx meters at the denitration outlet is reduced as compared with the conventional technology, the maintenance of the analytical meter becomes easier and the cost of the analytical meter becomes lower.
【図1】本発明の実施例になる煙道系統図。FIG. 1 is a flue system diagram according to an embodiment of the present invention.
【図2】本発明の実施例になるアンモニア流量調節弁の
制御系統図。FIG. 2 is a control system diagram of an ammonia flow rate control valve according to an embodiment of the present invention.
【図3】本発明の実施例におけるA、B系のアンモニア
注入量補正ピッチを示す図。FIG. 3 is a view showing A and B system ammonia injection amount correction pitches in an embodiment of the present invention.
【図4】従来技術による煙道系統図。FIG. 4 is a conventional flue system diagram.
【図5】従来技術によるアンモニア流量調節弁の制御系
統図。FIG. 5 is a control system diagram of an ammonia flow rate control valve according to a conventional technique.
【図6】従来技術による脱硝装置出口NOx濃度計を
A、B系兼用とした場合の煙道系統図。FIG. 6 is a flue system diagram when the NOx concentration meter at the outlet of the denitration device according to the related art is used for both A and B systems.
【図7】図6の従来技術においてA、B系脱硝出口NO
x濃度にアンバランスが生じた状態を示す概念図。FIG. 7 is a denitration outlet NO for A and B in the prior art of FIG.
FIG. 6 is a conceptual diagram showing a state in which an imbalance occurs in x density.
【図8】ボイラ燃焼排ガスの煙道への流動状況を示す模
式図。FIG. 8 is a schematic diagram showing a flow state of boiler combustion exhaust gas to a flue.
1…ボイラ、2…A系入口NOx濃度計、3…B系入口
NOx濃度計、4…A系アンモニア流量調節弁、5…A
系アンモニア供給管、6…B系アンモニア流量調節弁、
7…B系アンモニア供給管、8…A系脱硝反応器、9…
B系脱硝反応器、10…A系出口NOx吸引管、11…
B系出口NOx吸引管、12…切換弁、13…出口NO
x計、14…A系エアヒータ、15…B系エアヒータ、
16…煙突入口NOx計、17…煙突、18…負荷信
号、19…入口NOx信号、20…出口NOx濃度設定
器、21…平均出口NOx濃度信号、22…A系出口N
Ox濃度信号、23…B系出口NOx濃度信号、24…
アンモニア流量、25…処理ガス流量信号、26…要求
モル比、27…調節計、28…要求アンモニア量、30
…調節計、31…アンモニア流量調節弁、32…アンモ
ニア先行信号、33…A系出口NOx濃度計、34…B
系出口NOx濃度計。1 ... Boiler, 2 ... A system inlet NOx concentration meter, 3 ... B system inlet NOx concentration meter, 4 ... A system ammonia flow control valve, 5 ... A
System ammonia supply pipe, 6 ... B system ammonia flow rate control valve,
7 ... B system ammonia supply pipe, 8 ... A system denitration reactor, 9 ...
B-system denitration reactor, 10 ... A-system outlet NOx suction pipe, 11 ...
B system outlet NOx suction pipe, 12 ... switching valve, 13 ... outlet NO
x meter, 14 ... A system air heater, 15 ... B system air heater,
16 ... Chimney inlet NOx meter, 17 ... Chimney, 18 ... Load signal, 19 ... Inlet NOx signal, 20 ... Outlet NOx concentration setting device, 21 ... Average outlet NOx concentration signal, 22 ... A system outlet N
Ox concentration signal, 23 ... B system outlet NOx concentration signal, 24 ...
Ammonia flow rate, 25 ... Processing gas flow rate signal, 26 ... Required molar ratio, 27 ... Controller, 28 ... Required ammonia amount, 30
... Controller, 31 ... Ammonia flow rate control valve, 32 ... Ammonia preceding signal, 33 ... A system outlet NOx concentration meter, 34 ... B
System outlet NOx concentration meter.
Claims (3)
ガス煙道を2系統以上設け、各系統にアンモニア注入装
置と脱硝反応器および該反応器入口NOx濃度計を設け
たものにおいて、各系統兼用として設けた脱硝反応器出
口NOx濃度計と、各系統の脱硝反応器下流側排ガスを
それぞれサンプリングする手段と、該手段によりサンプ
リングされた全系統の排ガスの混合体を前記出口NOx
濃度計に供給して平均出口NOx濃度を検出する手段
と、各系統の入口NOx濃度計の検出値、出口NOx濃
度設定器の設定値および前記平均出口NOx濃度とに基
づき各系統それぞれの注入アンモニアモル比を算出する
手段と、注入アンモニアモル比と排ガス流量とに基づき
各系統の注入アンモニア量を制御する手段と、前記排ガ
スサンプリング手段に設けた切換手段により、各系統ご
との出口排ガスを前記出口NOx濃度計に供給して各系
統ごとの出口NOx濃度を検出する手段と、この検出値
と前記出口NOx濃度設定値の偏差に基づき前記注入ア
ンモニアモル比を補正する手段とを設けたことを特徴と
する複数の排ガス処理系統へのアンモニア注入量制御装
置。1. A system in which two or more exhaust gas flues for treating exhaust gas from an exhaust gas source are provided, and each system is provided with an ammonia injecting device, a denitration reactor and a NOx concentration meter at the inlet of the reactor NOx concentration meter at the outlet of the denitration reactor, means for sampling the exhaust gas on the downstream side of the denitration reactor of each system, and a mixture of the exhaust gases of all the systems sampled by the means are used as the outlet NOx.
Means for supplying the densitometer to detect the average outlet NOx concentration, and injection ammonia for each system based on the detection value of the inlet NOx concentration meter of each system, the set value of the outlet NOx concentration setter, and the average outlet NOx concentration A means for calculating the molar ratio, a means for controlling the injected ammonia amount of each system based on the injected ammonia molar ratio and the exhaust gas flow rate, and a switching means provided in the exhaust gas sampling means, the outlet exhaust gas for each system Means for supplying an NOx concentration meter to detect the outlet NOx concentration for each system, and means for correcting the injected ammonia molar ratio based on the deviation between the detected value and the outlet NOx concentration set value are provided. Ammonia injection amount control device for multiple exhaust gas treatment systems.
煙道を複数系統設け、各系統にアンモニア注入装置、脱
硝反応器、該反応器入口NOx濃度計、出口NOx濃度
設定器および反応器下流の排ガスサンプリング手段とを
設けたものにおいて、各系統兼用として設けた脱硝反応
器出口NOx濃度計と、前記排ガスサンプリング管より
サンプリングした全系統の混合排ガスに基づき前記出口
NOx濃度計により平均出口NOx濃度を検出する手段
と、前記入口NOx濃度計、平均出口NOx濃度検出手
段および出口NOx濃度設定器の出力値に基づき各系統
への注入アンモニアモル比を算出する手段と、常時に、
この注入アンモニアモル比と各系統の排ガス流量とに基
づき各系統へのアンモニア注入量を制御する手段を設け
るとともに、所定時間ごとに、前記排ガスサンプリング
手段に接続した切換手段により各系統ごとにサンプリン
グした排ガスに基づき前記出口NOx濃度計により各系
統ごとの出口NOx濃度を検出する手段と、この検出値
と前記出口NOx濃度設定器の設定値により前記注入ア
ンモニアモル比を補正する手段とを設けたことを特徴と
する複数の排ガス処理系統へのアンモニア注入量制御装
置。2. A plurality of exhaust gas flues for treating exhaust gas from a combustion device are provided, and an ammonia injection device, a denitration reactor, a NOx concentration meter at the inlet of the reactor, an NOx concentration setting device at the outlet, and a downstream of the reactor are provided in each system. In the exhaust gas sampling means provided, the NOx concentration meter outlet NOx concentration meter provided for both systems and the average outlet NOx concentration measured by the outlet NOx concentration meter based on the mixed exhaust gas of all systems sampled from the exhaust gas sampling pipe. Means for detecting, a means for calculating the molar ratio of ammonia injected into each system based on the output values of the inlet NOx concentration meter, the average outlet NOx concentration detecting means and the outlet NOx concentration setting device,
A means for controlling the amount of ammonia injected into each system based on the injected ammonia molar ratio and the exhaust gas flow rate of each system is provided, and at each predetermined time, sampling is performed for each system by the switching means connected to the exhaust gas sampling means. A means for detecting the outlet NOx concentration of each system by the outlet NOx concentration meter based on the exhaust gas, and a means for correcting the injected ammonia molar ratio by the detected value and the set value of the outlet NOx concentration setting device are provided. Ammonia injection amount control device for a plurality of exhaust gas treatment systems.
を複数系統設け、各系統にアンモニア注入装置、脱硝反
応器、該反応器入口NOx濃度計、出口NOx濃度設定
器および前記反応器下流の排ガスサンプリング管とを設
けたものにおいて、各系統兼用として設けた1台の出口
NOx濃度計と、各系統排ガスが合流した煙突入口煙道
から採取した排ガスに基づき前記NOx濃度計により平
均出口NOx濃度を検出する手段と、前記入口NOx濃
度計、出口NOx濃度設定器および平均出口NOx濃度
検出手段の出力値に基づき各系統への注入アンモニアモ
ル比を算出する手段と、この注入アンモニアモル比と各
系統の排ガス流量に基づき各系統へのアンモニア注入量
を制御する手段と、所定時間ごとに前記各系統の反応器
下流の排ガスサンプリング管に接続した切換手段により
各系統ごとにサンプリングした排ガスに基づき前記出口
NOx濃度計により各系統ごとの出口NOx濃度を検出
する手段と、この検出値と前記出口NOx濃度設定器の
設定値とにより前記注入アンモニアモルを補正する手段
を設けたことを特徴とする複数の排ガス処理系統へのア
ンモニア注入量制御装置。3. A plurality of combustion exhaust gas flues from an opposed combustion type boiler are provided, and an ammonia injection device, a denitration reactor, a NOx concentration meter at the inlet of the reactor, an NOx concentration outlet at the outlet, and a downstream of the reactor are provided in each system. In the case where an exhaust gas sampling pipe is provided, one outlet NOx concentration meter provided for each system and the average outlet NOx concentration measured by the NOx concentration meter based on the exhaust gas collected from the chimney inlet flue where each system exhaust gas merges Means for calculating the injection ammonia molar ratio to each system based on the output values of the inlet NOx concentration meter, the outlet NOx concentration setting device and the average outlet NOx concentration detecting means. Means for controlling the amount of ammonia injection into each system based on the exhaust gas flow rate of the system, and the exhaust gas sump downstream of the reactor of each system at predetermined time intervals A means for detecting the outlet NOx concentration of each system by the outlet NOx concentration meter based on the exhaust gas sampled for each system by the switching means connected to the ring pipe, and the detected value and the set value of the outlet NOx concentration setting device. A device for controlling the injection amount of ammonia into a plurality of exhaust gas treatment systems, characterized in that means for correcting the injected ammonia moles is provided.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP7156407A JPH09871A (en) | 1995-06-22 | 1995-06-22 | Ammonia injection amount control device for a plurality of exhaust gas treatment systems |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP7156407A JPH09871A (en) | 1995-06-22 | 1995-06-22 | Ammonia injection amount control device for a plurality of exhaust gas treatment systems |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH09871A true JPH09871A (en) | 1997-01-07 |
Family
ID=15627076
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP7156407A Pending JPH09871A (en) | 1995-06-22 | 1995-06-22 | Ammonia injection amount control device for a plurality of exhaust gas treatment systems |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH09871A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0866395A1 (en) * | 1997-03-21 | 1998-09-23 | Von Roll Umwelttechnik AG | Method and device for controlling the input quantity of a treating medium for reducing the nitrogen concentration in the exhaust gases of a burning process |
EP2559474A1 (en) * | 2011-08-19 | 2013-02-20 | Siemens Aktiengesellschaft | Method and device for reducing the quantity of pollutants in exhaust gases |
JP2016166847A (en) * | 2015-03-10 | 2016-09-15 | 中国電力株式会社 | Gas sampling device |
-
1995
- 1995-06-22 JP JP7156407A patent/JPH09871A/en active Pending
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0866395A1 (en) * | 1997-03-21 | 1998-09-23 | Von Roll Umwelttechnik AG | Method and device for controlling the input quantity of a treating medium for reducing the nitrogen concentration in the exhaust gases of a burning process |
EP2559474A1 (en) * | 2011-08-19 | 2013-02-20 | Siemens Aktiengesellschaft | Method and device for reducing the quantity of pollutants in exhaust gases |
US8557207B2 (en) | 2011-08-19 | 2013-10-15 | Siemens Aktiengesellschaft | Method and apparatus for reducing the quantity of pollutant in waste gases |
JP2016166847A (en) * | 2015-03-10 | 2016-09-15 | 中国電力株式会社 | Gas sampling device |
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