JPH0351453B2 - - Google Patents
Info
- Publication number
- JPH0351453B2 JPH0351453B2 JP57164059A JP16405982A JPH0351453B2 JP H0351453 B2 JPH0351453 B2 JP H0351453B2 JP 57164059 A JP57164059 A JP 57164059A JP 16405982 A JP16405982 A JP 16405982A JP H0351453 B2 JPH0351453 B2 JP H0351453B2
- Authority
- JP
- Japan
- Prior art keywords
- denitrification
- control
- value
- signal
- constant
- 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.)
- Expired - Lifetime
Links
- 238000000034 method Methods 0.000 claims description 20
- 230000009467 reduction Effects 0.000 claims description 20
- 239000007789 gas Substances 0.000 claims description 17
- 239000003638 chemical reducing agent Substances 0.000 claims description 11
- 238000002347 injection Methods 0.000 claims description 10
- 239000007924 injection Substances 0.000 claims description 10
- 238000002485 combustion reaction Methods 0.000 claims description 8
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 7
- 239000003546 flue gas Substances 0.000 claims description 7
- 230000007613 environmental effect Effects 0.000 claims description 4
- 230000004044 response Effects 0.000 claims description 3
- 239000000779 smoke Substances 0.000 description 24
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 20
- 238000006722 reduction reaction Methods 0.000 description 19
- 238000010586 diagram Methods 0.000 description 7
- 230000008859 change Effects 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 230000008901 benefit Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J4/00—Feed or outlet devices; Feed or outlet control devices
- B01J4/008—Feed or outlet control devices
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Treating Waste Gases (AREA)
- Feeding, Discharge, Calcimining, Fusing, And Gas-Generation Devices (AREA)
- Feedback Control In General (AREA)
Description
【発明の詳細な説明】
この発明は排煙脱硝装置に係り、特に還元剤注
入量調節弁を備え、排ガス中の窒素酸化物（以
下、NOxと記す）を低減するに好適な排煙脱硝
装置の還元剤注入制御方式に関するものである。[Detailed Description of the Invention] The present invention relates to a flue gas denitrification device, and particularly to a flue gas denitrification device equipped with a reducing agent injection amount control valve and suitable for reducing nitrogen oxides (hereinafter referred to as NOx ) in flue gas. The present invention relates to a reducing agent injection control method for the device.
従来、排煙脱硝装置のNOxの基本的な制御方
式としては、「排ガス流量」×「節炭器出口のNOx
値」により算定するNOx総量に、還元剤比率
（いわゆるモル比）を掛算して算出する還元剤例
えばアンモニアガス注入量要求信号と、実際のア
ンモニアガス注入量のフイードバツク信号との偏
差演算（または比率算出）を行ない、この偏差の
比例積分演算信号によつて、アンモニアガスの注
入量を制御する方法が一般に行なわれている。こ
れは排ガス中のNOxの総量に対して常に一定還
元比率のアンモニアガス注入量を測つて、全負荷
範囲で所定の脱硝性能を維持しようとするもので
ある。 Conventionally, the basic control method for NO x in flue gas denitrification equipment is the following: "exhaust gas flow rate" x "NO x at the exit of the economizer"
Calculate the difference between the reducing agent, for example, ammonia gas injection amount request signal, which is calculated by multiplying the total amount of NO x calculated by the reducing agent ratio (so-called molar ratio), and the feedback signal of the actual ammonia gas injection amount (or Generally, a method is used in which the amount of ammonia gas to be injected is controlled based on the proportional-integral calculation signal of this deviation. This measures the amount of ammonia gas injected at a constant reduction ratio with respect to the total amount of NO x in the exhaust gas, in order to maintain a predetermined denitrification performance over the entire load range.
しかし最近では、このような脱硝性能を常時一
定に維持する方式とは別に、煙突入口のNOx値
を検出してフイードバツクし、煙突入口のNOx
値を環境規制値と一致させた所定値に制御しよう
といういわゆる煙突入口NOx一定の制御を行う
方式が増加してきている。上記の目的は、脱硝装
置の最終目的である煙突入口NOx値を環境規制
上から所定値に常時維持することにより、部分負
荷におけるアンモニアガス注入量を抑制した経済
運用を図ることを主眼とするものである。このよ
うに従来方式には上記の二方式があり、現在その
いずれかの方式を採用している。 However, recently, in addition to this method of always maintaining constant denitrification performance, a method has been developed that detects and feeds back the NO x value at the smoke inlet .
There has been an increase in the number of so-called smoke inlet NO x constant control methods that attempt to control the NO x value to a predetermined value that matches the environmental regulation value. The above purpose is to achieve economical operation by suppressing the amount of ammonia gas injection at partial loads by constantly maintaining the smoke inlet NO It is something. As described above, there are the above-mentioned two conventional methods, and one of them is currently employed.
以下、第１図〜第３図により従来のNOx制御
系統を説明する。第１図は、脱硝装置のフロー説
明図、第２図は、脱硝還元比率一定のNOx制御
系統図を示す。第１図において、ボイラ１からの
排ガスは節炭器２を通り、脱硝反応器３へ導入さ
れる。還元剤の脱硝アンモニアガスは、脱硝アン
モニアガス量調節弁４を通つて脱硝反応器３へ注
入される。脱硝反応器３で還元処理された排ガス
は、煙突へ導かれ、大気中へ放出される。一方、
燃焼用空気は強制押込通風機（以下、EDFと記
す）７によつて空気予熱器８を通り、ボイラ１に
導かれる。節炭器２の出口の排ガスNOxは、節
炭器出口ガスNOx検出器６により、脱硝反応器
３への注入アンモニアガス量は、アンモニアガス
流量発信器５により、また燃焼用空気流量から図
示してない関数発生器１０によつて排ガス流量に
交換するところの燃焼用空気流量は、燃焼用空気
流量発信器９により、さらに煙突入口NOxは、
煙突入口NOx検出器２４によりそれぞれ検出さ
れる。従来のNOx制御の基本的制御方法の一つ
である脱硝還元比率（モル比）一定の制御は、処
理ガス流量（燃焼用空気流から変換作成）と節炭
器出口NOx値との積であるNOx総量に対し、一
定の完全比率における還元剤のアンモニアガス量
を注入して、全負荷範囲において所定な脱硝効果
を挙げようとするものである。 Hereinafter, a conventional NO x control system will be explained with reference to FIGS. 1 to 3. FIG. 1 is a flow explanatory diagram of the denitrification device, and FIG. 2 is a NO x control system diagram with a constant denitrification and reduction ratio. In FIG. 1, exhaust gas from a boiler 1 passes through a economizer 2 and is introduced into a denitrification reactor 3. The denitrified ammonia gas as a reducing agent is injected into the denitrified reactor 3 through the denitrated ammonia gas amount control valve 4 . The exhaust gas that has been reduced in the denitrification reactor 3 is led to the chimney and released into the atmosphere. on the other hand,
Combustion air is guided to the boiler 1 through an air preheater 8 by a forced draft fan (hereinafter referred to as EDF) 7. The exhaust gas NO x at the outlet of the economizer 2 is detected by the economizer outlet gas NO The combustion air flow rate, which is exchanged to the exhaust gas flow rate by a function generator 10 (not shown), is determined by the combustion air flow rate transmitter 9, and the smoke inlet NO x is
Each is detected by the smoke inlet NO x detector 24. Controlling the denitrification reduction ratio (molar ratio), which is one of the basic control methods of conventional NO x control, is based on the product of the process gas flow rate (converted from the combustion air flow) and the NO The aim is to achieve a predetermined denitrification effect over the entire load range by injecting an amount of ammonia gas as a reducing agent at a constant perfect ratio with respect to the total amount of NO x .
つぎに第２図によつて、従来の制御方式のうち
脱硝還元比率一定のNOx制御系統を説明する。
上記燃焼用空気流量発信器９の信号は、上記関数
発生器１０により処理ガス流量に変換され、掛算
器１１に入力される。一方の節炭器出口NOx値
信号は節炭器出口ガスNOx検出器６から発信さ
れて掛算器１１に入力され、「処理ガス流量」×
「節炭器出口NOx値」＝「NOx総量」が算定され
る。該NOx総量は、掛算器１２へ入力され、こ
こで還元比率設定器１３により与えられる還元比
率（モル比）が掛算されて脱硝アンモニアガス量
要求信号となり、該要求信号は、上記掛算器１２
あ接続する加算器３１に入力する。一方、上記掛
算器１１の出力端に微分器２０を接続し、NOx
総量が負荷変動によつて変化したことを検出の
上、その出力信号をゲイン調整器２１により増幅
して、信号制限器２２により上下限の制限を行う
とともに、変化率制限器２３によつて信号変化速
度の制限を加えた後、これを上記加算器３１に入
力させ、上記制限された脱硝アンモニアガス量要
求信号と加算して偏差演算器１４に入力させる。
該偏差演算器１４には、アンモニアガス流量発信
器５からの信号がフイードバツク信号として入力
し、上記両者の偏差演算結果が比例積分演算器１
５に入力して、この比例積分演算出力が脱硝アン
モニアガス量調整弁４の開度指令信号となつて、
加算器１７および切替器１８を通り脱硝アンモニ
アガス量調節弁４を駆動する。上記加算器１７
は、関数発生器１６とともに用い、掛算器１２か
らの脱硝アンモニアガス量要求信号による先行開
度信号として上記脱硝アンモニアガス量調節器４
の開度を規制するものである。また上記切替器１
８は、自動または手動切替器であつて、脱硝アン
モニアガス量調節弁４を手動によつて操作すると
きに、信号発生器１９からの信号によつて上記脱
硝アンモニアガス量調節弁４を操作する。上記方
式では、負荷変動時にNOx総量が急変する場合、
上記脱硝反応器３内におけるNOxとアンモニア
ガスとの還元反応の時間遅れにより一時的に脱硝
性能が低下するのを防ぐため、負荷上昇時には多
目に、また負荷降下時には少な目にアンモニアガ
ス量を調節することにより、負荷変動時における
脱硝性能の維持を図るものである。この制御方式
は、常時、還元比率を一定に保つて脱硝性能を維
持しようとするものであり、脱硝装置の最終目的
としての煙突入口のNOx値は、この制御結果と
してのみ与えられる。 Next, with reference to FIG. 2, a NO x control system with a constant denitrification/reduction ratio among conventional control systems will be explained.
The signal from the combustion air flow rate transmitter 9 is converted into a processing gas flow rate by the function generator 10 and input to a multiplier 11 . One economizer outlet NO x value signal is transmitted from the economizer outlet gas NO
The “NO x value at the exit of the economizer” = “total amount of NO x ” is calculated. The total NO
A is input to the adder 31 connected to A. On the other hand, a differentiator 20 is connected to the output terminal of the multiplier 11, and NO x
After detecting that the total amount has changed due to load fluctuation, the output signal is amplified by the gain adjuster 21, the upper and lower limits are limited by the signal limiter 22, and the change rate limiter 23 controls the signal. After limiting the rate of change, this is input to the adder 31, added to the limited denitrification ammonia gas amount request signal, and input to the deviation calculator 14.
The signal from the ammonia gas flow rate transmitter 5 is input as a feedback signal to the deviation calculator 14, and the result of the above-mentioned deviation calculation is input to the proportional-integral calculator 1.
5, and this proportional integral calculation output becomes the opening command signal for the denitrification ammonia gas amount adjustment valve 4.
The denitrified ammonia gas amount control valve 4 is driven through the adder 17 and the switch 18. Adder 17
is used together with the function generator 16, and the denitrification ammonia gas amount regulator 4 is used as a preliminary opening signal based on the denitrification ammonia gas amount request signal from the multiplier 12.
This controls the opening degree of the valve. In addition, the above switching device 1
Reference numeral 8 denotes an automatic or manual switching device, which operates the denitrification ammonia gas amount control valve 4 in response to a signal from the signal generator 19 when the denitrification ammonia gas amount control valve 4 is operated manually. . In the above method, if the total amount of NO x changes suddenly during load fluctuations,
In order to prevent the denitrification performance from temporarily decreasing due to a time delay in the reduction reaction between NO This adjustment aims to maintain denitrification performance during load fluctuations. This control method attempts to maintain denitrification performance by keeping the reduction ratio constant at all times, and the NO x value at the smoke inlet, which is the final objective of the denitrification device, is given only as a result of this control.
従来の制御方式の別の方式として、第３図に示
すような脱硝装置の制御目標すなわち最終目的で
ある煙突入口のNOx値を環境規制上の一定値に
維持しようとする制御方式がある。この方式は、
該第３図において、煙突入口NOx値の信号は煙
突入口NOx検出器２４から取出し、信号設定器
２５からの煙突入口のNOx設定値信号とともに
偏差演算器２６に入力して偏差演算を行ない、そ
の出力を掛算器２７に入力する。該掛算器２７
は、上記関数発生器１０に対して第２図の従来例
において示した信号ラインとは別の信号ラインを
介して接続し、ゲイン調整を行なつた後、比例積
分演算器２８を経て、上記掛算器１２に入力させ
るまでの構成を、上記第２図の従来例における還
元比率設定器１３と置き換えたもので、その他の
構成は上記第２図と同一である。 Another conventional control method is a control method as shown in FIG. 3, which attempts to maintain the NO x value at the smoke inlet, which is the control target or ultimate goal of the denitrification device, at a constant value in accordance with environmental regulations. This method is
In FIG. 3, the smoke inlet NO x value signal is taken out from the smoke inlet NO x detector 24 and inputted to the deviation calculator 26 together with the smoke inlet NO x setting value signal from the signal setting device 25 for deviation calculation. The output is input to the multiplier 27. The multiplier 27
is connected to the function generator 10 through a signal line different from the signal line shown in the conventional example of FIG. The configuration up to input to the multiplier 12 is replaced with the return ratio setting device 13 in the conventional example shown in FIG. 2 above, and the other configurations are the same as in FIG. 2 above.
上記のように、従来の制御方式では、脱硝還元
比率一定とするNOx制御、または煙突入口の
NOx値を一定とするNOx制御のいずれかの方式
を採用しているが、上記二方式の目的を双方とも
達成するような要望、すなわち脱硝装置の計画性
能を常時一定に維持する制御ができるとともに、
低負荷範囲では突入口のNOx値を必要以上に降
下させることなく、環境規制上の規定値に制御す
ることによつて、脱硝アンモニアガスの注入量を
抑制した経済運用をも行ない得る制御ができる方
式の開発が要望されていた。 As mentioned above, conventional control methods either control NO x with a constant denitrification/reduction ratio or
One of the NO x control methods that keeps the NO As well as being able to
In the low load range, by controlling the NO There was a demand for the development of a method that could do this.
この発明の目的は、上記の要望に応え、上記二
方式の性能を兼ね備えるとともに、両者の切替え
を任意の部分負担において、自動的かつ連続的に
移行させ得る排煙脱硝装置の還元剤注入制御方式
を提供するにある。 The purpose of this invention is to meet the above demands and provide a reducing agent injection control system for flue gas denitrification equipment that combines the performance of the above two systems and that can automatically and continuously switch between the two at any partial cost. is to provide.
要するにこの発明は、NOx制御の基本制御方
式の一つである下記の方式、すなわちNOx総量
（「処理ガス流量」×「節炭器出口NOx値」）に脱硝
還元比率（モル比）を掛けて算定するアンモニア
ガス注入量要求値と、実際のアンモニアガス注入
量との偏差を比例積分演算し、該演算出力信号を
もつてアンモニアガス注入量を決定するNOx制
御方式において、脱硝還元比率（モル比）の設定
回路に着目し、これを全負荷範囲で常に一定値に
維持するのではなく、任意の部分負荷から自動的
に還元比率を低下させて、低負荷範囲で煙突入口
NOx値を必要以上に降下させることなく環境規
制上の規定値に制御しようとするものであつて、
その手段として還元比率設定信号回路に加算器２
９を挿入し、該加算器２９において、煙突入口
NOx値のフイードバツク信号とその設定値との
偏差を比例積分演算した演算出力信号、すなわち
煙突入口NOx値一定制御信号を入力し、上記還
元比率設定器１３からの信号に加算し、任意の部
分負荷において自動的かつ連続的に還元比率一定
のNOx制御から煙突入口のNOx値一定の制御へ、
また、この逆に煙突入口NOx値一定の制御から
還元比率一定のNOx制御へ移行させることがで
きる。 In short, this invention uses the following method, which is one of the basic control methods for NO x control, that is, the total amount of NO x ("processed gas flow rate" x "NO In the NO x control method, the deviation between the required ammonia gas injection amount calculated by multiplying by Focusing on the ratio (mole ratio) setting circuit, instead of always maintaining this at a constant value over the entire load range, the reduction ratio is automatically lowered from any partial load, and the smoke inlet is set in the low load range.
The aim is to control the NO x value to the specified value according to environmental regulations without lowering it more than necessary.
As a means of this, an adder 2 is added to the return ratio setting signal circuit.
9, and in the adder 29, the smoke inlet
A calculation output signal obtained by proportional integral calculation of the deviation between the NO x value feedback signal and its set value, that is, a smoke inlet NO x value constant control signal is input, and added to the signal from the reduction ratio setting device 13, and then From NO x control with a constant reduction ratio automatically and continuously under partial load to control with a constant NO x value at the smoke inlet.
Moreover, on the contrary, it is possible to shift from control in which the smoke inlet NO x value is constant to NO x control in which the reduction ratio is constant.
以下、前述の従来の二つのニーズの両方の制御
機能を具備し、両者の一方または任意の部分負荷
において自動的に両者の切替えが可能となるよう
なこの発明を図面に基づいて説明する。第４図
は、この発明の一実施例の制御系統図を示す。な
お、図中、第１図〜第３図と同一または同等の部
位には同一の符号を付ける。まず上述の従来例第
３図と異なる点についてのみ構成を記すと、加算
器２９を介して還元比率制定器１３を掛算器１２
に接続し、上記加算器２９の入力端および出力端
をモニタリレー３０に接続するとともに、該モニ
タリレー３０を比例積分演算器２８に接続して、
該比例積分演算器２８を加算器２９に接続したも
ので、他の部分は上記第３図の従来例と同一であ
る。 Hereinafter, this invention will be described with reference to the drawings, which is equipped with control functions for both of the above-mentioned conventional needs and is capable of automatically switching between the two at one or any partial load. FIG. 4 shows a control system diagram of an embodiment of the present invention. In the drawings, the same or equivalent parts as in FIGS. 1 to 3 are given the same reference numerals. First, to describe only the configuration that differs from the conventional example shown in FIG.
, the input end and the output end of the adder 29 are connected to a monitor relay 30, and the monitor relay 30 is connected to the proportional-integral calculator 28,
The proportional-integral calculator 28 is connected to an adder 29, and the other parts are the same as the conventional example shown in FIG.
つぎに作用を説明する。脱硝装置入口のNOx
総量を燃焼用空気流量発信器９の出力信号から関
数発生器１０により変換する処理ガス流量と、節
炭器出口ガスNOx検出器６からのNOx値とを掛
算器１１において掛算算定し、掛算器１２へ入力
する。このNOx総量に対する脱硝還元比率を還
元比率設定器１３からの信号により加算器２９を
通つて掛算器１２へ与え、該掛算器１２の出力を
脱硝アンモニアガス量要求信号として脱硝還元比
率一定のNOx制御を行うことができる。一方、
脱硝還元比率の制定信号回路、すなわち還元比率
設定器１３からの信号ラインに設ける加算器２９
は、煙突入口のNOx値一定制御回路からの信号、
すなわち煙突入口NOx検出器２４からの信号を
偏差演算器２６へ入力し、信号設定器２５から与
えられる煙突入口NOx値制定信号とともに上記
偏差演算器２６によつて偏差演算を行ない、その
偏差を負荷に見合つてゲイン調整（NOx偏差量
に変換）をする掛算器２７を経て比例積分演算器
２８に入力する。該比例積分演算器２８の出力信
号によつて煙突入口のNOx値を規定値にしよう
とする制御信号を加算器２９に入力し、かつ該加
算器２９に上記還元比率設定器１３からの信号を
入力して加算し、任意の部分負荷から脱硝還元比
率一定制定値に換えて、煙突入口NOx値一定制
御信号を発生させ、これを掛算器１２において
NOx総量に掛算し、脱硝アンモニアガス量要求
信号として煙突入口NOx値一定の制御を達成す
るものである。 Next, the effect will be explained. NO x at the denitrification equipment inlet
The total amount is calculated by multiplying the processing gas flow rate converted by the function generator 10 from the output signal of the combustion air flow rate transmitter 9 by the NOx value from the economizer outlet gas NOx detector 6 in a multiplier 11, Input to multiplier 12. The denitrification reduction ratio with respect to the total amount of NO x control can be performed. on the other hand,
Adder 29 provided in the signal line for establishing the denitrification reduction ratio, that is, the signal line from the reduction ratio setting device 13
is the signal from the NO x value constant control circuit at the smoke inlet,
That is, the signal from the smoke inlet NO x detector 24 is input to the deviation calculator 26, and the deviation is calculated by the deviation calculator 26 together with the smoke inlet NO x value establishment signal given from the signal setting device 25. is inputted to the proportional-integral calculator 28 via a multiplier 27 that adjusts the gain (converts to NO x deviation amount) according to the load. A control signal for setting the NO x value at the smoke inlet to a specified value is input to the adder 29 using the output signal of the proportional-integral calculator 28, and a signal from the reduction ratio setting device 13 is input to the adder 29. is input and added up, and a constant set value of the denitrification reduction ratio is generated from an arbitrary partial load to generate a constant smoke inlet NO x value control signal, and this is sent to the multiplier 12.
It multiplies the NO x total amount and uses it as a denitrification ammonia gas amount request signal to achieve constant control of the NO x value at the smoke inlet.
以上説明したように、この発明によれば、脱硝
還元比率一定によるNOx制御と、煙突入口NOx
値一定制御の両方の性能を具備するとともに、任
意の部分負荷によつて両者を自動的に切替えるこ
とができるという効果が得られる。 As explained above, according to the present invention, NO x control using a constant denitrification reduction ratio and smoke inlet NO x
The present invention has the advantage of having the performance of both constant value control and being able to automatically switch between the two depending on an arbitrary partial load.
第１図は、脱硝装置のフロー説明図、第２図
は、脱硝還元比率一定のNOx制御系統図、第３
図は、煙突入口NOx値一定制御の制御系統図、
第４図は、この発明の一実施例の制御系統図を示
す。
符号の説明、１……ボイラ、２……節炭器、３
……脱硝反応器、４……脱硝アンモニアガス量調
節弁、５……アンモニアガス流量発信器、６……
節炭器出口ガスNOx検出器、７……FDF、８…
…空気予熱器、９……燃焼用空気流量発信器、１
０……関数発生器、１１……掛算器、１２……掛
算器、１３……還元比率設定器、１４……偏差演
算器、１５……比例積分演算器、１６……関数発
生器、１７……加算器、１８……切替器、１９…
…信号発生器、２０……微分器、２１……ゲイン
調整器、２２……信号制限器、２３……変化率制
限器、２４……煙突入口NOx検出器、２５……
信号設定器、２６……偏差演算器、２７……掛算
器、２８……比例積分演算器、２９……加算器、
３０……モニタリレー、３１……加算器。
Figure 1 is a flow explanatory diagram of the denitrification equipment, Figure 2 is a NO x control system diagram with a constant denitrification and reduction ratio, and Figure 3
The figure shows a control system diagram for constant NO x value control at the smoke inlet.
FIG. 4 shows a control system diagram of an embodiment of the present invention. Explanation of symbols, 1... Boiler, 2... Energy saver, 3
... Denitrification reactor, 4 ... Denitrification ammonia gas amount control valve, 5 ... Ammonia gas flow rate transmitter, 6 ...
Economizer outlet gas NO x detector, 7...FDF, 8...
... Air preheater, 9 ... Combustion air flow rate transmitter, 1
0... Function generator, 11... Multiplier, 12... Multiplier, 13... Reduction ratio setter, 14... Deviation calculator, 15... Proportional integral calculator, 16... Function generator, 17 ...Adder, 18...Switcher, 19...
... Signal generator, 20 ... Differentiator, 21 ... Gain adjuster, 22 ... Signal limiter, 23 ... Rate of change limiter, 24 ... Smoke inlet NO x detector, 25 ...
Signal setting device, 26... Deviation calculator, 27... Multiplier, 28... Proportional integral calculator, 29... Adder,
30...Monitor relay, 31...Adder.
Claims (1)
器内で接触反応させて脱硝を行う排煙脱硝装置に
おいて、上記脱硝反応器入口の排ガス流量と
NOx値から算出されるNOx総量に対する脱硝還
元比率が、NOx総量の変動に対応して常にほぼ
一定となるように脱硝還元剤の注入量を制御して
脱硝を行う脱硝制御手段と、脱硝した排ガスの上
記脱硝反応器出口におけるNOx値が、NOx総量
の変動に対応して常に所定の環境規制値以下とな
るように脱硝還元剤の注入量を制御して脱硝を行
う脱硝制御手段とを兼ね備え、上記脱硝反応器の
負荷が設定値以上の高負荷時には、上記脱硝還元
比率を一定とする脱硝制御を行い、上記負荷が設
定値以下の低負荷時には、上記脱硝反応器出口の
NOx値を一定とする脱硝制御に、それぞれ切替
えて脱硝を行うことを特徴とする排煙脱硝装置の
還元剤注入制御方法。1 In a flue gas denitrification device that denitrates NOx in combustion exhaust gas and a reducing agent by contacting it in a denitrification reactor, the exhaust gas flow rate at the entrance of the denitrification reactor and
a denitrification control means that performs denitrification by controlling the injection amount of a denitrification reducing agent so that the denitrification and reduction ratio to the total amount of NOx calculated from the NOx value is always approximately constant in response to fluctuations in the total amount of NOx ; Denitration control that performs denitration by controlling the injection amount of the denitrification reducing agent so that the NO x value of the denitrified exhaust gas at the outlet of the denitrification reactor is always below a predetermined environmental regulation value in response to fluctuations in the total amount of NO x When the load of the denitrification reactor is high, exceeding the set value, denitrification control is performed to keep the denitration reduction ratio constant, and when the load is low, below the set value, the denitrification control is performed at the outlet of the denitrification reactor.
A reducing agent injection control method for a flue gas denitrification device, characterized in that denitrification is performed by switching to denitrification control that keeps the NO x value constant.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57164059A JPS5955334A (en) | 1982-09-22 | 1982-09-22 | System for controlling injection of reducing agent in denitrator for stack gas |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57164059A JPS5955334A (en) | 1982-09-22 | 1982-09-22 | System for controlling injection of reducing agent in denitrator for stack gas |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5955334A JPS5955334A (en) | 1984-03-30 |
| JPH0351453B2 true JPH0351453B2 (en) | 1991-08-06 |
Family
ID=15785998
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57164059A Granted JPS5955334A (en) | 1982-09-22 | 1982-09-22 | System for controlling injection of reducing agent in denitrator for stack gas |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5955334A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61234914A (en) * | 1985-04-08 | 1986-10-20 | Nippon Kokan Kk <Nkk> | Controlling method for exhaust gas denitration facility |
| JPS61245826A (en) * | 1985-04-22 | 1986-11-01 | Nippon Kokan Kk <Nkk> | Apparatus for controlling denitration of flue gas |
| JPS6233532A (en) * | 1985-08-06 | 1987-02-13 | Toshiba Corp | Control device for waste gas denitration |
| CN105242012B (en) * | 2015-10-16 | 2017-09-01 | 苏州西热节能环保技术有限公司 | A kind of portable automatic switchover fast sampling denitrating flue gas test system |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5333977A (en) * | 1976-09-10 | 1978-03-30 | Unitika Ltd | Automatically controlling method for quantity of introduced nh3 in denitration plant for flue gas |
| JPS55119424A (en) * | 1979-03-09 | 1980-09-13 | Sumitomo Heavy Ind Ltd | Nh3 injection amount control method |
| JPS56163741A (en) * | 1980-05-20 | 1981-12-16 | Kawasaki Heavy Ind Ltd | Method for controlling feed rate or nh3 in dry denitration apparatus |
-
1982
- 1982-09-22 JP JP57164059A patent/JPS5955334A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5333977A (en) * | 1976-09-10 | 1978-03-30 | Unitika Ltd | Automatically controlling method for quantity of introduced nh3 in denitration plant for flue gas |
| JPS55119424A (en) * | 1979-03-09 | 1980-09-13 | Sumitomo Heavy Ind Ltd | Nh3 injection amount control method |
| JPS56163741A (en) * | 1980-05-20 | 1981-12-16 | Kawasaki Heavy Ind Ltd | Method for controlling feed rate or nh3 in dry denitration apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5955334A (en) | 1984-03-30 |
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