JPS63229126A - Control method for wet exhaust gas desulfurizer - Google Patents

Control method for wet exhaust gas desulfurizer

Info

Publication number
JPS63229126A
JPS63229126A JP62062564A JP6256487A JPS63229126A JP S63229126 A JPS63229126 A JP S63229126A JP 62062564 A JP62062564 A JP 62062564A JP 6256487 A JP6256487 A JP 6256487A JP S63229126 A JPS63229126 A JP S63229126A
Authority
JP
Japan
Prior art keywords
signal
flow rate
value
desulfurization
rate
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
Application number
JP62062564A
Other languages
Japanese (ja)
Other versions
JP2529244B2 (en
Inventor
Okikazu Ishiguro
石黒 興和
Yasuki Hashimoto
泰樹 橋本
Atsushi Kuramoto
庫本 篤
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Power Ltd
Original Assignee
Babcock Hitachi KK
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Filing date
Publication date
Application filed by Babcock Hitachi KK filed Critical Babcock Hitachi KK
Priority to JP62062564A priority Critical patent/JP2529244B2/en
Publication of JPS63229126A publication Critical patent/JPS63229126A/en
Application granted granted Critical
Publication of JP2529244B2 publication Critical patent/JP2529244B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Abstract

PURPOSE:To control the absorbent circulating flow rate at a high accuracy by forecasting the future desulfurization rate by means of simulation and correcting the demand for the absorbing liquid circulating flow rate from the difference between said forecast value and the set value. CONSTITUTION:A circulating flow rate demand signal 37 for circulating flow rate, a preceding value signal 33, a desulfurization rate feedback signal 38 and a desulfurizing forecast value feedback signal 39 are totaled by an adding machine 13a. The difference between the circulating flow rate demand signal 37 and a signal 49 from an absorption tower slurry circulating flow meter 4 is calculated, and a slurry circulating flow rate difference signal 58 is found by a subtractor 10e. From this difference, a pump flow rate control value is found a by regulator 11d, and a pump flow rate control signal 59 is signal processed, which is converted to a increasing and decreasing signal 18 of the number of revolutions at a pump flow rate control device 15, and the circulating flow rate of absorbing solution is controlled by controlling the number of revolutions of an absorption tower circulating pump 19.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は排煙脱硫装置の制御方法に係り、特に湿式排煙
脱硫装置に於ける補機の動力費を低減する事のできる制
御方法に関する。
[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a control method for a flue gas desulfurization system, and particularly relates to a control method that can reduce power costs for auxiliary equipment in a wet flue gas desulfurization system. .

〔従来の技術〕[Conventional technology]

第2図、゛第3図は湿式排煙脱硫装置の従来の制御方法
を示す。
Figures 2 and 3 show a conventional control method for a wet flue gas desulfurization system.

燃焼装置から排出される排ガスをダクト23を経て吸収
塔24に導入し、この吸収塔内で循環する吸収液26と
前記排ガスとを気液接触させる。
The exhaust gas discharged from the combustion device is introduced into the absorption tower 24 through the duct 23, and the absorption liquid 26 circulating within the absorption tower is brought into gas-liquid contact with the exhaust gas.

排ガス中のSO!は吸収液に吸収されて脱硫され、処理
後の排ガスは排出ライン28を経て系外に排出される。
SO in exhaust gas! is absorbed by the absorption liquid and desulfurized, and the treated exhaust gas is discharged out of the system through the discharge line 28.

一方、SO!を吸収した吸収液26は吸収塔24の底部
からタンク27に流下する。タンク27には吸収剤スラ
リ供給ライン30を経て吸収剤が供給されており、吸収
液26のSO□吸収性能を一定に保持するようにしてい
る。この吸収剤の添加により吸収性能を回復した吸収液
26は吸収塔循環ポンプ19により循環ライン25を経
て吸収塔24に再供給される。なお、循環液の一部は抜
き出しライン29を通って排出され、後続する工程にお
いて酸化され石膏とされる。
On the other hand, SO! The absorption liquid 26 that has absorbed the water flows down from the bottom of the absorption tower 24 to the tank 27. An absorbent is supplied to the tank 27 via an absorbent slurry supply line 30, so that the SO□ absorption performance of the absorbent liquid 26 is maintained constant. The absorption liquid 26 whose absorption performance has been restored by the addition of the absorbent is re-supplied to the absorption tower 24 via the circulation line 25 by the absorption tower circulation pump 19. Note that a part of the circulating fluid is discharged through the extraction line 29 and is oxidized into gypsum in a subsequent process.

このS Oを吸収装置において、従来は吸収剤の供給量
は次のように制御されている。
Conventionally, in this SO 2 absorption device, the supply amount of the absorbent is controlled as follows.

先ずI) H計6で抽出してた吸収液のPH値を測定し
、この検出したPHH値0を調節計11gに入力する。
First, I) Measure the pH value of the extracted absorption liquid using the H meter 6, and input the detected PHH value 0 to the controller 11g.

調節計11gでは塔頂に至る吸収液OP H値が一定と
なるようP H値補正信号41を加算器13bに出力す
る。−力負荷検出器22からのSO2信号42、即ち脱
硫プラントの負荷を)★出し、加算器13gに入力する
。加算器13bでは調節計11gからのPH補正値信号
41と負荷検出器22からのSO2信号42とを加算し
、調節計11fに吸収剤スラリ流量設定値信号43とし
て入力する。調節計11fはこれらの信号43及びスラ
リ流量計3からのスラリ流量信号44に基づいて、吸収
剤スラリ流量調節弁21を吸収剤スラリ調節信号45に
より制御する。
The controller 11g outputs a PH value correction signal 41 to the adder 13b so that the OPH value of the absorbent liquid reaching the top of the column is constant. - Output the SO2 signal 42 from the power load detector 22, that is, the load of the desulfurization plant) and input it to the adder 13g. The adder 13b adds the PH correction value signal 41 from the controller 11g and the SO2 signal 42 from the load detector 22, and inputs the result to the controller 11f as an absorbent slurry flow rate setting value signal 43. Based on these signals 43 and the slurry flow rate signal 44 from the slurry flow meter 3, the controller 11f controls the absorbent slurry flow rate control valve 21 using an absorbent slurry control signal 45.

ここで、吸収塔24に於ける脱硫性能、つまり脱硫率は
循環ライン25を流動する吸収液の循環流量によって大
きく左右される。この場合、燃焼装置の負荷の変動に関
わらず常に目標の脱硫効率を得るためには、吸収液の循
環流量の最適な制御を行うことが必要であることは周知
の事実である。
Here, the desulfurization performance in the absorption tower 24, that is, the desulfurization rate, is largely influenced by the circulation flow rate of the absorption liquid flowing through the circulation line 25. In this case, it is a well-known fact that in order to always obtain the target desulfurization efficiency regardless of fluctuations in the load of the combustion device, it is necessary to optimally control the circulating flow rate of the absorption liquid.

この循環星制御方弐としては例えば特開昭60−110
320がある。この方式によると、吸収塔24に流入す
る排ガスの負荷量に対応してシミュレーションモデルに
基づき吸収塔24を循環する吸収液の最適PH値及び吸
収液循環ポンプ19の最適稼動台数を設定し、これら設
定値に基づいて吸収剤の供給量及び稼動ポンプ台数を制
御する。
As a method for controlling this circulating star, for example, Japanese Patent Application Laid-open No. 60-110
There are 320. According to this method, the optimum pH value of the absorption liquid circulating in the absorption tower 24 and the optimum number of operating absorption liquid circulation pumps 19 are set based on a simulation model in accordance with the load amount of exhaust gas flowing into the absorption tower 24. The amount of absorbent supplied and the number of operating pumps are controlled based on the set values.

燃焼装置の負荷安定時には算出されている最適稼動台数
から1を減じた台数を設定し、かつ前記算出されている
PH値に予め定めた増加分を加えた値を設定する。さら
にこれら設定値をシミュレーションモデルに入力し、モ
デル条件を満たしている場合、変更された設定値に基づ
いて吸収剤の供給流量及び稼動ポンプ台数を制御してい
る。
When the load of the combustion devices is stable, the number of combustion devices is set by subtracting 1 from the calculated optimal number of operating devices, and a value is set by adding a predetermined increase to the calculated PH value. Furthermore, these set values are input into the simulation model, and if the model conditions are satisfied, the supply flow rate of the absorbent and the number of operating pumps are controlled based on the changed set values.

〔発明が解決しようとする問題点〕[Problem that the invention seeks to solve]

しかし以上の従来方法には次のような問題があり、その
解決が望まれている。
However, the conventional methods described above have the following problems, and a solution to these problems is desired.

湿式排煙脱硫プラントの特性として、吸収剤スラリの投
入の対するPH値の応答性は極めて悪((時定数は40
分程度)、PH値の最適設定値を変更しても、実際のP
H値がこの設定値に達する迄には最短でもこの時定数に
対応する40分程度の時間がかかってしまう。
As a characteristic of a wet flue gas desulfurization plant, the response of the pH value to the input of absorbent slurry is extremely poor ((time constant is 40
Even if you change the optimum setting value of the PH value, the actual P
It takes at least about 40 minutes corresponding to this time constant for the H value to reach this set value.

更に実際のPH値がP H設定値よりも大幅に低いよう
な場合には、吸収剤スラリの過剰投入が生じ、非常に不
経済となる。
Furthermore, if the actual PH value is significantly lower than the PH set value, excessive amount of absorbent slurry will be added, which will be very uneconomical.

またP H値を設定値に保証するため吸収剤スラリ流量
調節弁21の開度が頻繁に変化するため、弁21の寿命
が短くなってしまう。
Furthermore, since the opening degree of the absorbent slurry flow control valve 21 changes frequently in order to guarantee the PH value at the set value, the life of the valve 21 is shortened.

通常、吸収塔循環ポンプ19の稼動台数は4台程度であ
るが、頻繁な負荷変動時にはポンプを作動させるモータ
の起動時間の制限により実質的にはポンプの稼動台数制
御が追いつかず、制御遅れが生じる。
Normally, the number of operating absorption tower circulation pumps 19 is about four, but when there are frequent load fluctuations, the limit on the start-up time of the motor that operates the pumps makes it virtually impossible to control the number of operating pumps, resulting in control delays. arise.

また上記従来方法では次の点に付いての配慮がなされて
いなっかった。
Further, the above conventional method does not take into account the following points.

即ち、吸収液の組成が遷移状態にある場合、つまり全量
酸化領域(吸収液中に亜硫酸カルシウムが存在しない領
域)から部分酸化領域(液中に亜硫酸カルシウムが存在
する領域)へ遷移する状態では脱硫率が数%程度も急激
に低下し、この結果脱硫率を目標値に維持できない事態
も生じるが、従来方法はこの点についての配慮はなされ
ていなかった。
In other words, when the composition of the absorbent liquid is in a transition state, that is, when it transitions from a fully oxidized region (a region where calcium sulfite is not present in the absorbent fluid) to a partially oxidized region (a region where calcium sulfite is present in the fluid), desulfurization occurs. The desulfurization rate suddenly decreases by several percentage points, and as a result, there are cases where the desulfurization rate cannot be maintained at the target value, but conventional methods have not taken this point into account.

以上のように従来方法にあっては、一定の効果を発揮す
るものの、解決すべき問題も多分にあった。
As described above, although the conventional methods exhibit certain effects, there are many problems that need to be solved.

〔問題点を解決するための手段〕[Means for solving problems]

本発明は上述した問題点を除去すべく構成したのもであ
り、実際の脱硫プラントの挙動を忠実に模擬することの
できるシミュレーションモデルを用いて、オンラインで
計測することのできない状態量を求めて、脱硫率の将来
値を予測し、これにより循環ポンプによる脱硫率制御を
行わせるようにした湿式脱硫装置の制御方法であること
を特徴とする。
The present invention was constructed to eliminate the above-mentioned problems, and uses a simulation model that can faithfully simulate the behavior of an actual desulfurization plant to obtain state quantities that cannot be measured online. The present invention is characterized in that it is a control method for a wet desulfurization apparatus in which the future value of the desulfurization rate is predicted and the desulfurization rate is controlled by a circulation pump based on this prediction.

〔作用〕[Effect]

本発明は排ガス流量、入口5Ott!11度、吸収剤ス
ラリ流量、吸収液循環流量、吸収液PH値、出ロSOz
7M度のオンライン計測信号に基づいてリアルタイムシ
ミュレーションモデルを同定し、この同定されたシミュ
レーションモデルをオフラインシミュレーションモデル
として使用し、将来の脱硫率を予測し、この予測値と目
標値との偏差に基づいて、循環流量デマンドを補正し、
吸収液循環流量を制御する。
The present invention has an exhaust gas flow rate of 5 Ott at the inlet! 11 degrees, absorbent slurry flow rate, absorption liquid circulation flow rate, absorption liquid PH value, output SOz
A real-time simulation model is identified based on the online measurement signal of 7M degrees, and this identified simulation model is used as an offline simulation model to predict the future desulfurization rate, and based on the deviation between this predicted value and the target value. , correct the circulating flow demand,
Control the absorption liquid circulation flow rate.

〔実施例〕〔Example〕

以下本発明の実施例を図面を参考に具体的に説明する。 Embodiments of the present invention will be specifically described below with reference to the drawings.

第1図は本発明の実施例を示す。FIG. 1 shows an embodiment of the invention.

図中符号8はリアルタイムシミュレーションモデルを示
す。このモデルの内容を示せば次のとおりである。
Reference numeral 8 in the figure indicates a real-time simulation model. The contents of this model are as follows.

吸収液の組成を、源側と固形物側に分け、これら源側と
固形物側を以下の組成で代゛表させる。
The composition of the absorption liquid is divided into the source side and the solids side, and the source side and solids side are represented by the following compositions.

先ず源側の組成は次のとおりである。First, the composition on the source side is as follows.

Total Ca、 Total Na5Total 
Mg、 Total CITotal 503 、To
tal SO4、Total NO,−5Total 
CO3とし、 また固形物側の組成は次のものとする。
Total Ca, Total Na5Total
Mg, Total CITotal 503, To
tal SO4, Total NO, -5Total
CO3, and the composition of the solid material is as follows.

CaC0z(S) 、Ca5O*(S) 、Ca5Q、
(S)ここで、反応速度としてCaC03(S)の溶解
速度、脱炭酸速度、Sol吸収速度、Ca5Oz(S)
及びCa S 04(S)の晶析速度、酸化速度を考慮
すると、運転条件と全体の物質バランスからTo ta
 l液組成を求める事ができる。次ぎにイオンバランス
、マスバランス及び平衡条件によりこのTo ta 1
液組成から各化学種の濃度(〔H〕、〔OR3[H3O
3)  ・・・・・・)を求める。
CaC0z(S), Ca5O*(S), Ca5Q,
(S) Here, the reaction rates are CaC03(S) dissolution rate, decarboxylation rate, Sol absorption rate, Ca5Oz(S)
Considering the crystallization rate and oxidation rate of CaS04(S), Tota
The liquid composition can be determined. Next, this To ta 1 is determined by ion balance, mass balance, and equilibrium conditions.
From the liquid composition, the concentration of each chemical species ([H], [OR3[H3O
3) Find ......).

このような液組成の計算が必要なのは、液組成の如何に
より反応速度が変化するためである。
This calculation of the liquid composition is necessary because the reaction rate changes depending on the liquid composition.

またPH値の計算値C*PH)は以下の式で求めること
ができる。
Further, the calculated value C*PH) of the PH value can be obtained using the following formula.

*PH=−logI0〔H〕 ・・・・・ (1)脱硫
率の計算値(ホη)は次式から求める。
*PH=-logI0[H]... (1) The calculated value of desulfurization rate (Hη) is obtained from the following formula.

”+7”1  exh(BTLI −RTIJ L ’
RTIJ pH・RTtl e  −RTLI sat
 )・・・ (2) BTU=  j!n (1770)  ・・・(3)こ
こで、 (H”):水素イオン濃度 η。:基準の脱硫率 RT U : Rerative、 Transfer
 UnitL:吸収液循環流量 G:排ガス流量 So□ :入口5Oza度 である。
”+7”1 exh(BTLI-RTIJ L'
RTIJ pH・RTtl e -RTLI sat
)... (2) BTU= j! n (1770)...(3) Here, (H"): Hydrogen ion concentration η.: Standard desulfurization rate RTU: Relative, Transfer
Unit L: Absorption liquid circulation flow rate G: Exhaust gas flow rate So□: Inlet 5Oza degree.

次ぎに脱硫率の目標値η11、を得るために必要な循環
流量の先行値Ldは上記式(3)により下記式(4)と
して求めることができる。
Next, the preceding value Ld of the circulation flow rate required to obtain the target value η11 of the desulfurization rate can be obtained from the above equation (3) as the following equation (4).

Ld = r  (RTUtd)    ・・・ (4
)また上記式に於けるR T U Ldは以下の式(5
)で求める。
Ld = r (RTUtd) ... (4
) In the above formula, R T U Ld is expressed as the following formula (5
).

・・・ (5) このリアルタイムシミュレーションモデル8は排ガス流
量計1からの排ガス流量信号46、入口SO□濃度計2
からの入口SO2濃度信号47、吸収剤ス′ラリ流量計
3からの吸収剤スラリ流量信号48、吸収塔スラリ循環
流量計4からの吸収塔スラリ循環流量信号49、PH計
6のPH信号51を入力し、液組成を計算し、前記式(
1)によりPH値を算出してPH値算出信号32を減算
器10bに出力する。また式(3)により脱硫率を計算
し、この脱硫率計算値信号31を減算器10cに出力す
る。式(4)、(5)により循環流量先行値を計算し、
この循環流量先行値信号33を加算器13aに出力する
。リアルタイムシミュレーションモデル8のオンライン
同定は、入口SCh濃度計2からの入口SCh濃度信号
47及び出口SOzYM度計5の出口SO□濃度信号5
0に基づき、減算器10aからの入ロ出ロSO□濃度差
信号53及び割算器12において実測の脱硫率を算出す
る。この脱硫率信号17を減算器10cに入力し、この
減算器10cにおいて前述の脱硫率計算値信号31と脱
硫信号17との脱硫率偏差を求め、その脱硫率偏差信号
54を調節計11bで信号処理し、BTU修正信号34
としてリアルタイムシミュレーションモデル8に入力す
る。次ぎにPH計6のP H信号51とPH計算値信号
32とによるP H偏差信号56を減算器10bで求め
、これを調節計113で信号処理し、吸収剤の溶解速度
定数の修正を行い、この吸収剤溶解速度定数修正信号3
5をリアルタイムシミュレーションモデル8に人力する
。なお吸収剤の溶解速度は次の式で求める事ができる。
... (5) This real-time simulation model 8 includes the exhaust gas flow rate signal 46 from the exhaust gas flow meter 1, the inlet SO□ concentration meter 2
, an inlet SO2 concentration signal 47 from the absorbent slurry flow meter 3, an absorbent slurry flow rate signal 48 from the absorbent slurry flow meter 3, an absorption tower slurry circulation flow rate signal 49 from the absorption tower slurry circulation flow meter 4, and a PH signal 51 from the PH meter 6. Enter and calculate the liquid composition and use the above formula (
1), the PH value is calculated and a PH value calculation signal 32 is output to the subtracter 10b. Further, the desulfurization rate is calculated using equation (3), and this desulfurization rate calculation value signal 31 is output to the subtractor 10c. Calculate the circulating flow rate advance value using equations (4) and (5),
This circulating flow rate advance value signal 33 is output to the adder 13a. Online identification of the real-time simulation model 8 is performed using the inlet SCh concentration signal 47 from the inlet SCh concentration meter 2 and the outlet SO□ concentration signal 5 of the outlet SOzYM concentration meter 5.
0, the input/output SO□ concentration difference signal 53 from the subtractor 10a and the divider 12 calculate the actually measured desulfurization rate. This desulfurization rate signal 17 is input to the subtractor 10c, and the desulfurization rate deviation between the desulfurization rate calculation value signal 31 and the desulfurization signal 17 is determined by the subtractor 10c, and the desulfurization rate deviation signal 54 is sent to the controller 11b as a signal. Process and BTU correction signal 34
input into the real-time simulation model 8 as Next, a PH deviation signal 56 from the PH signal 51 of the PH meter 6 and the calculated PH value signal 32 is obtained by the subtractor 10b, and this signal is processed by the controller 113 to correct the dissolution rate constant of the absorbent. , this absorbent dissolution rate constant correction signal 3
5 to the real-time simulation model 8. The dissolution rate of the absorbent can be calculated using the following formula.

ここで、 T:吸収剤溶解速度 に:吸収剤溶解速度定数 〔H〕 :水素イオン濃度 [Ca):カルシウムイオン濃度 〔X〕 :吸収剤濃度 a、b、c :定数 である。here, T: Absorbent dissolution rate : Absorbent dissolution rate constant [H]: Hydrogen ion concentration [Ca): Calcium ion concentration [X]: Absorbent concentration a, b, c: constant It is.

吸収剤のPH値は吸収剤の溶解速度に大きく支配される
ので、上述のような修正を行う。
Since the pH value of the absorbent is largely controlled by the dissolution rate of the absorbent, the above-mentioned correction is performed.

次ぎに吸収液の組成中、亜硫酸カルシウムの存在の存無
が吸収液の脱硫性能に大きな影響を及ぼす。亜硫酸カル
シウムはSO□の吸収によって生じるが、この亜硫酸カ
ルシウムが排ガス中にあるOtによって全量酸化される
場合と、一部が酸化される場合がある。このうち全量酸
化領域では吸収液中のSO□分圧が部分酸化領域の場合
に比較して低いため、同一のP H値でも脱硫性能が向
上することになる。この点についてのモデルの修正は以
下のように実施する。
Next, the presence or absence of calcium sulfite in the composition of the absorbent greatly affects the desulfurization performance of the absorbent. Calcium sulfite is produced by the absorption of SO□, and in some cases, this calcium sulfite is completely oxidized by Ot in the exhaust gas, and in other cases, it is partially oxidized. Among these, in the fully oxidized region, the partial pressure of SO□ in the absorbent is lower than in the partially oxidized region, so the desulfurization performance is improved even with the same pH value. The model is modified in this regard as follows.

〔CaSO3〕〉εのとき RTUpH=RTUpH・・・ (7a)(Ca S 
O:l )≦εのとき RT U ’ ru = k RT U PH・・・ 
(7b)k>l、k=f  (PH) ここで (Ca SO3):亜硫酸カルシウム濃度ε:定数 である。
[CaSO3]> When ε, RTUpH=RTUpH... (7a) (Ca S
O:l)≦ε, RT U' ru = k RT U PH...
(7b) k>l, k=f (PH) where (Ca SO3): calcium sulfite concentration ε: constant.

リアルタイムシミュレーションモデル8においてはオン
ライン計測が困難である亜硫酸カルシウムの濃度を計算
できるので、部分酸化/全景酸化領域の判定が可能とな
り、この領域によって、前記RTUPHのデータを前記
式(7a)、(7b)のように修正する。このようにし
てリアルタイムシミュレーションモデル8は実機と同様
の挙動を示すことになり、この状態でオンライン固定さ
れる。
Since the real-time simulation model 8 can calculate the concentration of calcium sulfite, which is difficult to measure online, it is possible to determine the partial oxidation/total oxidation region, and this region allows the RTUPH data to be calculated using the equations (7a) and (7b). ). In this way, the real-time simulation model 8 exhibits the same behavior as the actual machine, and is fixed online in this state.

次ぎにオフラインシミュレーションモデル9は、リアル
タイムシミュレーションモデル8と全く同じ構造を持つ
シミュレーションモデルであり、パラメータの同定信号
、即ちBTU修正信号34及び吸収剤溶解速度定数修正
信号35を入力する。
Next, the offline simulation model 9 is a simulation model having exactly the same structure as the real-time simulation model 8, and inputs parameter identification signals, that is, a BTU correction signal 34 and an absorbent dissolution rate constant correction signal 35.

またこれと共に運転状態ベクトル信号16.即ち排ガス
流量計1、入口SO,濃度計2、吸収剤スラリ流量計3
、吸収塔スラリ循環流量計4の出力信号を入力して、将
来の脱硫予測信号36を出力する。
Additionally, the operating state vector signal 16. Namely, exhaust gas flowmeter 1, inlet SO, concentration meter 2, absorbent slurry flowmeter 3
, the output signal of the absorption tower slurry circulation flow meter 4 is input, and a future desulfurization prediction signal 36 is output.

脱硫設定器7からの脱硫率設定値信号52と脱硫率信号
17の脱硫率偏差信号60を減算器10dで求めて、調
節計110で信号処理し、更に脱硫率フィードバック信
号38として加算器13aに入力する。脱硫率予測値信
号36と脱硫率設定信号52との脱硫率偏差信号57は
減算器10fにより求めて、係数器14aで係数を掛け
た信号を、脱硫率予測値フィードバック信号39として
加算器13aに入力する。
The desulfurization rate setting value signal 52 from the desulfurization setting device 7 and the desulfurization rate deviation signal 60 of the desulfurization rate signal 17 are obtained by the subtractor 10d, signal processed by the controller 110, and further sent to the adder 13a as the desulfurization rate feedback signal 38. input. A desulfurization rate deviation signal 57 between the desulfurization rate predicted value signal 36 and the desulfurization rate setting signal 52 is obtained by the subtracter 10f, and the signal obtained by multiplying by a coefficient by the coefficient unit 14a is sent to the adder 13a as the desulfurization rate predicted value feedback signal 39. input.

以上のように循環流量デマンド信号37は、循環流量を
、先行値信号−33、脱硫率フィードバック信号38、
脱硫率予測値フィードバック信号39を加算器13aで
合算する。この循環流量デマンド信号37と吸収塔スラ
リ循環流量計4からの吸収塔スラリ循環流量信号49と
の偏差を算出し、このスラリ循環流量偏差信号58を減
算器108で求める。更にこれに基づき調節計lidで
ポンプ流量制御値を求め、このポンプ流量制御信号59
を信号処理し、ポンプ流量制御装置15に於いて、ポン
プの回転数増減信号18に変換し、吸収塔循環ポンプ1
9の回転数制御を行い、これにより吸収液の循環流量を
制御する。
As described above, the circulation flow rate demand signal 37 indicates the circulation flow rate by the preceding value signal -33, the desulfurization rate feedback signal 38,
The desulfurization rate predicted value feedback signals 39 are summed by an adder 13a. The deviation between this circulation flow rate demand signal 37 and the absorption tower slurry circulation flow rate signal 49 from the absorption tower slurry circulation flow meter 4 is calculated, and this slurry circulation flow rate deviation signal 58 is obtained by a subtractor 108. Furthermore, based on this, the pump flow rate control value is determined by the controller lid, and this pump flow rate control signal 59
is processed and converted into a pump rotational speed increase/decrease signal 18 in the pump flow rate control device 15, and the absorption tower circulation pump 1
9, and thereby control the circulation flow rate of the absorption liquid.

次に、吸収剤スラリ流量の制御方式としては第2図に示
すように従来方式の吸収剤過剰率一定制御方式等が考え
られる。同図において、吸収剤スラリ流量は入口s o
z i! (排ガス流量計1の出力信号として入口SO
□濃度計2の出力信号とを積算した掛算吸収20の出力
信号)に対して一定の比率で吸収剤スラリを供給するこ
とになる。すなわち、係数器14bで一定の係数を掛け
、その値を、吸収剤スラリ流量を補正値として減算器l
Next, as a control method for the absorbent slurry flow rate, a conventional absorbent excess rate constant control method as shown in FIG. 2 can be considered. In the same figure, the absorbent slurry flow rate is
z i! (Inlet SO is used as output signal of exhaust gas flow meter 1.
□The absorbent slurry is supplied at a constant ratio to the output signal of the multiplication absorber 20 (multiplying the output signal of the concentration meter 2). That is, the multiplier 14b multiplies a constant coefficient, and the value is multiplied by the subtractor l, using the absorbent slurry flow rate as a correction value.
.

gにおいて補正し、調節計11eにおいて調節弁作動1
(3号とし、この信号に基づいてスラリ流量調節弁21
を制御することよりスラリ流量を調節する。
g, and the controller 11e adjusts the control valve operation 1.
(No. 3, and based on this signal, the slurry flow control valve 21
Adjust the slurry flow rate by controlling.

〔効果〕〔effect〕

本発明は以上にその内容を詳細に説明したように、リア
ルタイムシミュレーションモデルがオンライン固定され
るので、オンライン計測が困難な液組成を確実に把握す
ることが可能となり、吸収剤循環流量を高精度で制御で
き、Wi環ポンプの動力を無駄に消費することがなくな
る。
As explained above in detail, the present invention allows the real-time simulation model to be fixed online, making it possible to reliably grasp the liquid composition, which is difficult to measure online, and to measure the absorbent circulation flow rate with high precision. control, and the power of the Wi ring pump is not wasted.

また液組成の予測が可能となったため、酸化領域と部分
酸化領域との間の大幅な変動を予め予測でき、燃焼装置
のあらゆる負荷状態に対応して脱硫率を高く保持するこ
とができる。
Furthermore, since it is now possible to predict the liquid composition, large fluctuations between the oxidation region and the partially oxidation region can be predicted in advance, making it possible to maintain a high desulfurization rate in response to all load conditions of the combustion device.

更にまた、吸収液P)(値を積極的に制御することがな
いので、PH値の大幅な変化に対しても吸収剤の過剰投
入を避けることができ、酸化工程における硫酸の消費量
が急激に増加することもない等、各種の効果を発揮する
Furthermore, since the absorption liquid P) (value is not actively controlled, it is possible to avoid adding too much absorbent even when there is a large change in the pH value, and the amount of sulfuric acid consumed in the oxidation process is reduced rapidly. It exhibits various effects such as no increase in the amount of water.

【図面の簡単な説明】[Brief explanation of drawings]

第1図は本発明の実施例を示す制御系統図、第2図は吸
収剤スラリ流量制御系統図、第3図は従来技術による脱
硫プラントの制御概念図である。 1・・・排ガス流量計  2・・・入口SO□濃度計 
 3・・・吸収塔スラリ流量計 4・・・吸収塔スラリ循環流置針 5・・・出口so、;1度計 7・・・脱硫率設定器 8・・・リアルタイムシミュレーションモデル9・・・
オフラインシミュレーションモデル15・・・ポンプ流
量制御装置 17・・・脱硫率信号 2工・・・吸収剤スラリ流量調節弁 24・・・吸収塔  25・・・吸収液循環ライン 2
6・・・吸収液 46・・・排ガス流量信号  47・・・入口SO□濃
度信号  48・・・吸収剤スラリ流量信号  49・
・・吸収塔スラリ循環流量信号50・・・P H値信号 第1図 第2図
FIG. 1 is a control system diagram showing an embodiment of the present invention, FIG. 2 is an absorbent slurry flow control system diagram, and FIG. 3 is a conceptual diagram of control of a desulfurization plant according to the prior art. 1...Exhaust gas flow meter 2...Inlet SO□ concentration meter
3...Absorption tower slurry flow meter 4...Absorption tower slurry circulation flow needle 5...Outlet so, ;1 degree meter 7...Desulfurization rate setting device 8...Real-time simulation model 9...
Offline simulation model 15... Pump flow rate control device 17... Desulfurization rate signal 2... Absorbent slurry flow rate control valve 24... Absorption tower 25... Absorbent circulation line 2
6... Absorbing liquid 46... Exhaust gas flow rate signal 47... Inlet SO□ concentration signal 48... Absorbent slurry flow rate signal 49.
...Absorption tower slurry circulation flow rate signal 50...PH value signal Fig. 1 Fig. 2

Claims (1)

【特許請求の範囲】[Claims] 燃焼装置から排出される排ガス中の硫黄酸化物を吸収液
を用いて除去する装置における吸収液循環流量を制御す
る方法において、先ず吸収液のリアルタイムシミュレー
ションモデルを設定し、このリアルタイムシミュレーシ
ョンモデルをオンライン計測信号を用いて修正し、この
修正モデルをオフラインシミュレーションモデルとして
使用して将来の脱硫率を予測し、脱硫率の予測値と設定
値との間の偏差を算出し、この偏差に基づいて吸収液循
環流量のデマンドに対する補正を行うことを特徴とする
湿式排煙脱硫装置の制御方法。
In a method for controlling the absorption liquid circulation flow rate in a device that uses an absorption liquid to remove sulfur oxides from exhaust gas discharged from a combustion device, a real-time simulation model of the absorption liquid is first set, and this real-time simulation model is measured online. This modified model is used as an offline simulation model to predict the future desulfurization rate, calculate the deviation between the predicted desulfurization rate and the set value, and calculate the deviation of the absorption liquid based on this deviation. A method for controlling a wet flue gas desulfurization device, characterized by correcting a demand for a circulating flow rate.
JP62062564A 1987-03-19 1987-03-19 Absorption liquid circulation controller for wet flue gas desulfurization equipment Expired - Fee Related JP2529244B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP62062564A JP2529244B2 (en) 1987-03-19 1987-03-19 Absorption liquid circulation controller for wet flue gas desulfurization equipment

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP62062564A JP2529244B2 (en) 1987-03-19 1987-03-19 Absorption liquid circulation controller for wet flue gas desulfurization equipment

Publications (2)

Publication Number Publication Date
JPS63229126A true JPS63229126A (en) 1988-09-26
JP2529244B2 JP2529244B2 (en) 1996-08-28

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ID=13203905

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Country Status (1)

Country Link
JP (1) JP2529244B2 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02152519A (en) * 1988-12-06 1990-06-12 Babcock Hitachi Kk Method for controlling amount of slurry circulated in wet stack gas desulfurizing device
JPH02180617A (en) * 1988-12-29 1990-07-13 Ishikawajima Harima Heavy Ind Co Ltd Control of waste gas desulfurization apparatus
JPH02180616A (en) * 1988-12-29 1990-07-13 Ishikawajima Harima Heavy Ind Co Ltd Control of waste gas desulfurization apparatus
WO2011065118A1 (en) * 2009-11-24 2011-06-03 三菱重工業株式会社 System for controlling operation of desulfurization apparatus
CN105126595A (en) * 2015-09-20 2015-12-09 华南理工大学 Simplified desulfuration system for simulating power plant desulphurization efficiency
WO2019172088A1 (en) 2018-03-06 2019-09-12 三菱日立パワーシステムズ株式会社 Operation support system and operation support method for desulfurization equipment

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5932924A (en) * 1982-08-19 1984-02-22 Mitsubishi Heavy Ind Ltd Controlling method of desulfurizing ratio in waste gas desulfurizing apparatus applied with wet lime method
JPS59199021A (en) * 1983-04-26 1984-11-12 Mitsubishi Heavy Ind Ltd Controlling method of wet lime-gypsum desulfurization plant
JPS60110321A (en) * 1983-11-18 1985-06-15 Mitsubishi Heavy Ind Ltd Control of exhaust gas desulfurizing plant

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5932924A (en) * 1982-08-19 1984-02-22 Mitsubishi Heavy Ind Ltd Controlling method of desulfurizing ratio in waste gas desulfurizing apparatus applied with wet lime method
JPS59199021A (en) * 1983-04-26 1984-11-12 Mitsubishi Heavy Ind Ltd Controlling method of wet lime-gypsum desulfurization plant
JPS60110321A (en) * 1983-11-18 1985-06-15 Mitsubishi Heavy Ind Ltd Control of exhaust gas desulfurizing plant

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02152519A (en) * 1988-12-06 1990-06-12 Babcock Hitachi Kk Method for controlling amount of slurry circulated in wet stack gas desulfurizing device
JPH02180617A (en) * 1988-12-29 1990-07-13 Ishikawajima Harima Heavy Ind Co Ltd Control of waste gas desulfurization apparatus
JPH02180616A (en) * 1988-12-29 1990-07-13 Ishikawajima Harima Heavy Ind Co Ltd Control of waste gas desulfurization apparatus
WO2011065118A1 (en) * 2009-11-24 2011-06-03 三菱重工業株式会社 System for controlling operation of desulfurization apparatus
CN105126595A (en) * 2015-09-20 2015-12-09 华南理工大学 Simplified desulfuration system for simulating power plant desulphurization efficiency
WO2019172088A1 (en) 2018-03-06 2019-09-12 三菱日立パワーシステムズ株式会社 Operation support system and operation support method for desulfurization equipment

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Publication number Publication date
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