JPS58143878A - Method of controlling injection of chemical - Google Patents

Abstract

PURPOSE:To enable to perform the highly-accurate feed forward of injecting chemicals in response to long-term variation in the quality of water caused by seasons or the like, by injecting the chemicals according to the model of calculation modified by the measured value of the quality of water before and after the injection of the chemicals. CONSTITUTION:A part 10 for modifying the formula of a feed foward model is provided at the arithmetic unit 1 of a means for controlling the injection of chemicals. A feed foward part 2 finds the ratio Y of injection from each measured value Xi (i=1-n), and a feed back part 3 finds the deviation DELTAY of the injection ratio from measured values Zi (i=1-n). The time when the measured values Zi are obtained, a time lag from a point for injecting the chemicals (the point of an injector 4) to a measuring point 8 and a time lag from a measuring point 5 for the measured values Xi to the measuring point 7 are taken into consideration. The formula of calculation at the modifying part 10 is determined in a manner such that a feed back value is made at 0. On the other hand, using a measured value from a flow meter 6, the required amount of the chemicals is injected from the injector 4 according to the modified formula of calculation.

Description

【発明の詳細な説明】 本発明は、水処理栴設の薬品注入制御装置に係り、特に
薬品注入前後の水質を測定して注入量を計算する演舞装
置を備えた制御方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a chemical injection control device for water treatment facilities, and more particularly to a control method equipped with a performance device that measures the water quality before and after chemical injection and calculates the injection amount.

従来の水処理施設の薬品注入制御の一実施例全糖１図に
示す。注入量を計算す６ｆＪ算装置１は、水質計５の測
定イ…より計算を行なうフィードフォワード部２と、水
質計７の測定値より計算を行なうフィードバック部３か
らなり、これらを加えて流用・計６の測定値を乗じて注
入量を求め、注入機４に指令を出す。このような施設に
おいて、通常は薬品注入地点（４の地点）から水質測定
地点（７の地点）寸でにはある程を畠の時間遅れがあ６
゜このｔめ、７によ／）ｄ相定１１自がある目イ尭イ１
自ＶＣ達していなかった場合、フィードバックを行なう
が、今測定した水自体の水質を変化させろことはできな
い。従ってフィードバック部３の佃ｔ゛１はぼ０になる
ようＶＣフィードフォワード部２の精度ケよくしなけれ
ばならない。しかしながら、通常フィードフォワード部
２の計藷一式は固定であるため、気温、天１次、季節、
長年にわた／）慶水の水質の変化等に対応することがで
きない。また、対応策としてフィードフォワ−ド部２の
計算式のパラメータヲ変更させる場合でも、操作員の勘
で行なわれ−Ｃいるために、人手がかかり、かつ梢１１
ｔもあまりよくないという欠点があった。An example of conventional chemical injection control in a water treatment facility is shown in Figure 1. The 6fJ calculation device 1 that calculates the injection amount consists of a feedforward section 2 that performs calculations based on the measurement values of the water quality meter 5, and a feedback section 3 that performs calculations based on the measured values of the water quality meter 7. The injection amount is determined by multiplying the total 6 measured values, and a command is issued to the injection machine 4. In such facilities, there is usually a certain amount of time delay between the chemical injection point (point 4) and the water quality measurement point (point 7).
゜This t is 7/) d phase constant 11 is the eye I 1
If the own VC has not been reached, feedback is provided, but the quality of the water itself that has just been measured cannot be changed. Therefore, the accuracy of the VC feedforward section 2 must be improved so that the t1 of the feedback section 3 becomes approximately 0. However, since the set of instruments in the feedforward unit 2 is usually fixed, temperature, celestial temperature, season, etc.
Over the years, we have been unable to respond to changes in Keisui's water quality. Furthermore, even when changing the parameters of the calculation formula of the feedforward unit 2 as a countermeasure, this is done based on the intuition of the operator, which requires a lot of manpower and
There was also a drawback that t was not very good.

本発明の目的は、季節や長期的な水廚の変化に対応でき
る鞘変の高いフィードフォワード制仰機Ｕヒ全備えた薬
品注入制御方法を提供することにある。An object of the present invention is to provide a chemical injection control method that is equipped with a feedforward suppressor U that has a high sheath change and can respond to seasonal and long-term water changes.

本発明ではこの目的ケ達１゛るために、フィ　−ドフォ
ワード部による演算結果、実際の注入率、及びフィード
バック部による演ｐ結果の３つのデータより、フィード
フォワード部のモデル式に対してフィードバック全行な
う演算装置を設け、常に犬除の永別に通したイ参ｉ１Ｅ
されたモデル式でフィードフォワード制御を行ｌ１５．
。In order to achieve this objective 1, the present invention provides feedback to the model equation of the feedforward section based on three types of data: the calculation result of the feedforward section, the actual injection rate, and the calculation result of the feedback section. Isan i1E was equipped with a calculation device that performs all operations, and was constantly passed through the Eibetsu of dog removal.
Feedforward control is performed using the model formula shown in line l15.
.

以ド、本発明の一実施例を第２図によって説明する。第
２図は８ｇ１図の従来の楽品注入制（財）装置の演算装
置ｌに、フィードフォワードモデル式修正部ｌＯ？設け
たものである。次に各演箕部について説１明する。捷す
、フィードフォワード部２は各測定頭Ｘ＋＋１＝１〜ｎ
）ｊり注入率Ｙを求Ｖ〕るものであり、次式で衣わされ
る。Hereinafter, one embodiment of the present invention will be described with reference to FIG. Figure 2 shows the feed forward model equation correction unit lO? It was established. Next, we will explain each theater section. The feedforward section 2 separates each measuring head X++1=1 to n
)j to find the injection rate Y, which is given by the following equation.

Ｙ二１’　ｆＸＩ　、　ｘｔ　、・・・Ｘｆｉ）　　　
　　　　　　　（１’）オは一般的な意味での関数を示
す。ここではさらに具体的な例としてｎ＝２で、ｆが線
形であるとする。すなわち、 Ｙ””　ａ　＋Ｘ、＋　＋ａ２Ｘ２　＋ａ、　　　””
　　　　　（２）ａ、１ｉ＝ｌ〜３）、パラメータ １だ、フィードバンク部３は同様に測定頭Ｚ＋（１−１
〜１ｎ　）から注入率−差ΔＹを求ぬるもので次式で表
わされる。Y21' fXI, xt,...Xfi)
(1') O indicates a function in a general sense. Here, as a more specific example, it is assumed that n=2 and f is linear. That is, Y"" a +X, + +a2X2 +a, ""
(2)a, 1i=l~3), parameter 1, feed bank section 3 similarly measures the measurement head Z+(1-1
~1n) to find the injection rate-difference ΔY, which is expressed by the following equation.

ΔＹ＝ｇ　ｆＺ＋　　、Ｚｔ　、　・　Ｚ、）　　　　
　　　（３）ｇ−関数 ここでやはり具体例としてｍ　＝　１とし、ｇを次のよ
うな関数とする。ΔY=g fZ+ , Zt , ・Z,)
(3) g-function Here, as a concrete example, let m = 1 and let g be the following function.

ΔＹ　＝　ｂ　−Ｚ　　　　　　　　　　　　　　　　
（４）ｂ　：　１ｉ１１］ボ１１白Ｚの目標価寸な、ト
ータル注入率をＹとする。ΔY = b −Z
(4) b: 1i11] Let Y be the total injection rate that is the target price of Bo11 white Z.

△ Ｙ＝Ｙ＋ΔＹ（５） 次に、測定頭Ｚを４′ｆｃ時刻をｔとすると、そのｌ１
ｌｌＩ駕した水に注入した薬品の注入率けＹｌｔ−α）
となる。但しαは注入地点（４の地点）から測定点（７
の地点）までの時間遅れを示す。また、その注入率の計
貢に用いた測定頭ＸＩはＸＩ　（を−γ）となる。γは
測定点（５の地点）から測定点（７の地点）までの時間
遅れである。これらをまとめると次のようになる。・ Ｙ　（Ｌ　−（１）＝ａ１Ｘ１１　ｔ−’ｒ　）＋ａ２
Ｘ２　（ｔ　　ｒ　）＋ａｓ（６） ／＼ Ｙｆｔ−α）−”ｌ’（ｔ−α）＋Δｙ（を−α）（７
）ｆｆｉわち、水質がＸＩ　（ｔ−ｒ）、　Ｘｔ　　（
ｆ、−ｒ　）テ△ あった水にＹ（ｔ−α）たけ薬品を注入した結束侍られ
た水の水′紹の目標帥との差は、ｂ−ｚ（ｔ）となる。△Y=Y+ΔY(5) Next, if the measurement head Z is 4'fc time is t, then l1
Injection rate of chemicals injected into water (Ylt-α)
becomes. However, α is the distance from the injection point (point 4) to the measurement point (point 7).
indicates the time delay to the point). In addition, the measurement head XI used to calculate the injection rate is XI (-γ). γ is the time delay from the measurement point (point 5) to the measurement point (point 7). These can be summarized as follows.・Y (L - (1) = a1X11 t-'r) + a2
X2 (t r )+as(6) /\Yft-α)-"l'(t-α)+Δy(-α)(7
)ffi, that is, the water quality is XI (t-r), Xt (
f, -r) te△ The difference between the water that was bound and the water that was filled with Y(t-α) amount of chemicals and the target amount of water is b-z(t).

ここで、式（２）のパラメータａ、（ｎ＝１〜３）の内
、季節や長期的水質の変化ケ含むＪｌがａ２であるとす
ると、今の１回のループでａ、を修正するならば次のよ
うになる。Here, if Jl, which includes seasonal and long-term water quality changes, is a2 among the parameters a and (n = 1 to 3) in equation (2), then a is corrected in the current one loop. Then it becomes as follows.

８２′＝［Ｙ（ｔ−ａ）＋（ｂ−Ｚｔ）ｌ−（ａｌＸＩ
　ｆｔ−ｒ）＋ａ、ｌンＸ２（ｔ−ｒ）（８） つ甘り最初からａ２がａ！であったならば今回のループ
ＶＣおいてフィードバック＠け０となり、かつ最紺目伸
（１Ｇと一欽するというｆ１盲ａ【を求めるのである。82'=[Y(t-a)+(b-Zt)l-(alXI
ft-r)+a, lnX2(t-r) (8) A2 is a from the beginning! If so, in this loop VC, feedback @ ke 0 and f1 blind a[ which is the same as the most dark blue (1G) is sought.

さらに、ある周期Ｔにおいてこれらの修ＩＥ個の平均を
とる。すなわち、 Ｘ２（ｔ　　ｒ）　　　（９） となり、これがフィードフォワードモデル式修正部１０
の中の計偉式となる。以上のような方法で制御を竹なつ
と、周期１゛毎にパラメータａ２　が自動的に修ｒＥさ
れ、より適したモデル式でフィードフォワード制御を行
なうことができる。Furthermore, in a certain period T, the average of these modified IEs is taken. In other words, X2(t r) (9) This becomes
It becomes a ceremony in the middle of the day. When the control is carried out in the manner described above, the parameter a2 is automatically modified every cycle, and feedforward control can be performed using a more suitable model formula.

本発明によれは、季節や長期的な水質の変化に対応した
より精度の制い制御が行なえるので、処ｆ！ｌＩ後の水
質が安定するとともに、薬品Ｉｒ、七°効に使用できる
。また、操作員がパラメータを修正する心安がない点で
、操作性が向上した。According to the present invention, more precise control can be performed in response to seasonal and long-term changes in water quality, so it is possible to control the water quality more accurately. The water quality after Ir is stabilized, and it can be used as a chemical Ir. In addition, operability has been improved because the operator does not have to worry about modifying parameters.

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

第１図は、従来の薬品注入制御ブロック図であり、第２
図は、本発明の一実施例の制御ブロック図である。FIG. 1 is a conventional chemical injection control block diagram.
The figure is a control block diagram of one embodiment of the present invention.

Claims (1)

【特許請求の範囲】[Claims] １、薬品注入前及び優の水質を聞ｊ定するｉｌ゛側器と
、これらの測定１１０僅にｉｔ１′簀モテルに従って薬
品を注入する注入機からなる水処理施設において、薬品
注入前後の水′凶夾迎］１１自により該計算モデルを修
正することを特許とする楽品注入制釧ｊ方法、。1. In a water treatment facility consisting of a side device for measuring water quality before and after chemical injection, and an injection machine for injecting chemicals according to these measurements, water quality before and after chemical injection is measured. 11. A music injection system patented method for modifying the calculation model by 11.