JP2841409B2 - DO control device - Google Patents

DO control device

Info

Publication number
JP2841409B2
JP2841409B2 JP1015868A JP1586889A JP2841409B2 JP 2841409 B2 JP2841409 B2 JP 2841409B2 JP 1015868 A JP1015868 A JP 1015868A JP 1586889 A JP1586889 A JP 1586889A JP 2841409 B2 JP2841409 B2 JP 2841409B2
Authority
JP
Japan
Prior art keywords
air volume
aeration
aeration tank
flow rate
meter
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 - Fee Related
Application number
JP1015868A
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Japanese (ja)
Other versions
JPH02194897A (en
Inventor
利憲 金谷
逸朗 藤田
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.)
YASUKAWA DENKI KK
Original Assignee
YASUKAWA DENKI KK
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Priority to JP1015868A priority Critical patent/JP2841409B2/en
Publication of JPH02194897A publication Critical patent/JPH02194897A/en
Application granted granted Critical
Publication of JP2841409B2 publication Critical patent/JP2841409B2/en
Anticipated expiration legal-status Critical
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Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W10/00—Technologies for wastewater treatment
    • Y02W10/10—Biological treatment of water, waste water, or sewage

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  • Activated Sludge Processes (AREA)

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、下水処理において最も広範に利用されてい
る活性汚泥法における曝気槽内のDO一定制御装置に関す
る。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a constant DO control device in an aeration tank in an activated sludge method most widely used in sewage treatment.

〔従来の技術〕[Conventional technology]

活性汚泥法は、活性汚泥（好気性微生物群）の作用に
よって、流入下水中の汚濁物質を吸着し、分解し、下水
の浄化を図るものである。この方法においては、作用の
主体となる活性汚泥を良好な環境下に維持しなければな
らない。The activated sludge method adsorbs and decomposes pollutants in influent sewage by the action of activated sludge (aerobic microorganisms) to purify the sewage. In this method, the activated sludge that acts as the main component must be maintained in a favorable environment.

環境条件の第一要因に挙げられるのが、水中の溶存酸
素濃度（DO）であり、これを確保するために、曝気槽に
空気が吹き込まれる。The first factor in environmental conditions is the dissolved oxygen concentration (DO) in water, and air is blown into the aeration tank to ensure this.

しかし、曝気風量が過剰になると、活性汚泥が微細化
し、浄化能力の低下、最終沈澱池での沈降性悪化を招く
とともに、エネルギー的にも大きな損失となる。However, if the amount of aeration air becomes excessive, the activated sludge becomes finer, lowering the purification capacity, worsening the sedimentation property in the final sedimentation basin, and causing a large energy loss.

以上の点を考慮し、曝気槽出口部のDOを一定に維持す
るDO一定制御が実施されている。In consideration of the above points, the DO constant control for keeping the DO at the outlet of the aeration tank constant is implemented.

第３図に、従来実施されているPI（比例積分）制御系
によるDO一定制御のブロック図を示す。この制御系によ
れば、曝気槽出口部に設置されたDO計２によって検出さ
れたDO計測値と、予め設定されている設定DO値９を用
い、DO調節計３によって、所要の曝気風量が計算され
る。この計算は、設定DO値９とDO計測値の偏差及びDO計
測値の変化速度を用いたPI計算による方法が一般的であ
る。FIG. 3 shows a block diagram of DO constant control by a conventionally implemented PI (proportional-integral) control system. According to this control system, the required aeration air volume is calculated by the DO controller 3 using the DO measurement value detected by the DO meter 2 installed at the outlet of the aeration tank and the preset DO value 9. Is calculated. This calculation is generally performed by a PI calculation using the deviation between the set DO value 9 and the DO measurement value and the change speed of the DO measurement value.

次に、計算によって得られた所要曝気風量は、設定曝
気風量10として、風量調節計４に入力される。風量調節
計４では、風量計５による計測風量と設定曝気風量10か
ら、風量調節用の電磁弁６の操作量を計算し、電磁弁６
に開閉操作指令を出力する。Next, the required aeration air volume obtained by the calculation is input to the air volume controller 4 as the set aeration air volume 10. The air volume controller 4 calculates the operation amount of the solenoid valve 6 for adjusting the air volume from the air volume measured by the air volume meter 5 and the set aeration air volume 10.
And outputs an opening / closing operation command.

従来は、以上の工程により、曝気槽出口部のDO値を一
定に維持するよう制御していた。Conventionally, according to the above steps, the DO value at the outlet of the aeration tank was controlled to be kept constant.

ところで、曝気槽内のDOの変動は、流入汚濁負荷すな
わち曝気槽流入下水流量と曝気槽流入下水中汚濁物質濃
度の積の変動や、活性汚泥の呼吸速度の変化によって生
じる。The fluctuation of DO in the aeration tank is caused by a change in inflow pollution load, that is, a change in a product of a flow rate of sewage flowing into the aeration tank and a concentration of pollutants in the aeration tank, and a change in a respiration rate of the activated sludge.

これらの要因のうち、曝気流入下水流量以外の要因に
ついては、変化速度が比較的小さく、従来の制御系にお
いても対応が可能であった。しかし、曝気槽流入下水流
量は、最初沈澱池へ下水を送水する汚水ポンプの運転状
況によって決定され、汚水ポンプの運転は台数制御によ
ることが多い。Among these factors, those other than the aeration-inflow sewage flow rate have a relatively low change speed, and can be handled even by the conventional control system. However, the flow rate of sewage flowing into the aeration tank is initially determined by the operation status of the sewage pump that sends sewage to the sedimentation basin.

したがって、汚水ポンプの台数変更によって生じる曝
気槽流入下水流量の変動は、急峻で、変化量も大きいも
のとなる。このような変動に対して、従来の制御系で
は、対応が困難であった。Therefore, the fluctuation of the aeration tank inflow sewage flow rate caused by the change in the number of sewage pumps is steep and the change amount is large. It is difficult for the conventional control system to cope with such a change.

〔発明が解決しようとする課題〕[Problems to be solved by the invention]

上述のように、従来のDO一定制御系では、汚水ポンプ
の台数変更によって発生する曝気槽流入下水流量の変動
に対処し、DOを一定値に維持することが困難であった。As described above, in the conventional DO constant control system, it is difficult to maintain the DO at a constant value while coping with the fluctuation of the flow rate of sewage flowing into the aeration tank caused by the change in the number of sewage pumps.

すなわち、汚水ポンプの台数増設時には、曝気槽流入
下水流量が急激に増大し、曝気槽内DOの低下が起きる。
また、汚水ポンプの台数減少時には、DOの上昇が発生す
るという問題が、従来のDO一定制御系には存在した。That is, when the number of sewage pumps is increased, the flow rate of sewage flowing into the aeration tank rapidly increases, and the DO in the aeration tank decreases.
Further, when the number of sewage pumps is reduced, there is a problem that the DO rises in the conventional DO constant control system.

本発明の目的は、上述の問題点に鑑みて、曝気槽流入
下水流量の急激な変動にも対処し得るDO一定制御装置を
提供することにある。An object of the present invention is to provide a constant DO control device that can cope with a rapid change in the flow rate of sewage flowing into an aeration tank in view of the above problems.

〔課題を解決するための手段〕[Means for solving the problem]

この目的を達成するため、本発明のDO制御装置は、曝
気槽内に設置されたDO計を検出端とし、曝気風量調節計
を操作端とするPI制御装置と、前記曝気槽内に流入する
下水の時間当たり流入量を計測する曝気槽流入下水流量
計と、前記曝気槽入流下水流量計で計測された曝気槽流
入下水流量の変動を検出する流入量変動検出装置と、前
記流入量変動検出装置で検出された流入量の変動が前記
DO計の設置点へ到達する時間を曝気槽の容積Vat及び前
記流入量変動検出装置（13）で流入量の変動が検出され
た時点において、前記曝気槽流入下水流量計（８）で計
測された曝気槽流入下水流量Ｑに基づいて算定する到達
時間演算装置と、曝気槽流入下水流量計の計測値と前記
DO計（２）で計測されたDO計測値が変動しない安定な状
態での風量倍率とを記憶する風量倍率記憶装置と、該風
量倍率記憶装置に記憶されている風量倍率及び曝気槽流
入下水流量から所要曝気風量を推定する所要曝気風量推
定装置と、前記到達時間演算装置によって算定される到
達時間後に前記風量倍率記憶装置に記憶されている風量
倍率から算定される推定所要風量になるように曝気風量
の変更予定を決定する曝気風量設定装置と、前記DO計の
計測値と設定DO値との偏差から曝気風量の補正量を算定
する積分成分演算装置とを備えたことを特徴とする。In order to achieve this object, the DO control device of the present invention includes a PI control device having a DO meter installed in an aeration tank as a detection end and an aeration air volume controller as an operation end, and flowing into the aeration tank. An aeration tank inflow sewage flow meter for measuring an inflow amount per hour of sewage, an inflow amount fluctuation detecting device for detecting a change in the aeration tank inflow sewage flow rate measured by the aeration tank inflow sewage flow meter, and the inflow amount fluctuation detection Fluctuations in the inflow rate detected by the device
At the time the change of the inflow amount is detected the time to reach to the installation point of the DO meter volume V at and the flow rate of the aeration tank fluctuation detector (13), measured in the aeration tank inflow sewage flow meter (8) An arrival time calculating device for calculating based on the obtained aeration tank inflow sewage flow rate Q,
A flow rate magnification storage device for storing a flow rate magnification in a stable state where the DO measurement value measured by the DO meter (2) does not fluctuate, a flow rate magnification stored in the flow rate magnification storage device, and a flow rate of sewage flowing into the aeration tank. A required aeration air volume estimating device for estimating a required aeration air volume from the air flow, and aeration so that an estimated required air volume calculated from the air volume magnification stored in the air volume magnification storage device after the arrival time calculated by the arrival time calculation device is obtained. An aeration air volume setting device for determining a change schedule of the air volume, and an integral component calculating device for calculating a correction amount of the aeration air volume from a deviation between the measured value of the DO meter and the set DO value.

〔実施例〕〔Example〕

以下、本発明を図面に示す実施例に基づいて具体的に
説明する。Hereinafter, the present invention will be specifically described based on embodiments shown in the drawings.

第１図は本発明の実施例を示すブロック図である。曝
気槽１には、その出口部のDO値を計測するDO計２が設け
られており、その計測値と設定DO値９から、DO調節計３
ではPI演算により、設定曝気風量10が出力される。風量
調節計４では、設定曝気風量10を目標値、風量計５から
の出力を計測値として、PI演算により、設定曝気風量10
を維持するように、電動弁６への開閉操作指令を出力す
る。これにより、ブロワ７からの曝気風量が制御され
る。FIG. 1 is a block diagram showing an embodiment of the present invention. The aeration tank 1 is provided with a DO meter 2 for measuring the DO value at the outlet, and the DO controller 3 is calculated from the measured value and the set DO value 9.
Then, the set aeration air volume 10 is output by PI calculation. The air flow controller 4 uses the set aeration air flow 10 as a target value and the output from the air flow meter 5 as a measurement value to calculate the set aeration air flow 10 by PI calculation.
Is output to the motor-operated valve 6 so that is maintained. Thus, the amount of aeration air from the blower 7 is controlled.

風量倍率記憶装置11においては、曝気槽流入下水流量
計８の計測値とDO計測値とが安定しているときの曝気槽
流入下水流量と曝気風量の比、すなわち風量倍率を演算
し、記憶する。積分成分演算装置12では、DO計測値と制
定DO値の偏差から、曝気風量の補正量を演算する。流入
量変動検出装置13においては、流入下水量の計測値か
ら、流入下水流量の変動を検出し、到達時間演算装置14
及び所要曝気風量推定装置15に変動が発生したことを出
力するとともに、設定曝気風量切換指令18を出力し、設
定曝気風量10の出力源を、平常時のDO調節計３から曝気
風量設定装置17系統に切り替える。The air volume magnification storage device 11 calculates and stores the ratio of the aeration tank inflow sewage flow rate and the aeration air volume when the measured value of the aeration tank inflow sewage flow meter 8 and the DO measurement value are stable, that is, the air volume magnification. . The integral component calculator 12 calculates a correction amount of the aeration air volume from a deviation between the DO measurement value and the established DO value. The inflow variation detection device 13 detects a variation in the inflow sewage flow rate from the measured value of the inflow sewage amount,
In addition to the fact that the required aeration air volume estimating device 15 has changed, the set aeration air volume switching command 18 is output, and the output source of the set aeration air volume 10 is output from the DO controller 3 in the normal state to the aeration air volume setting device 17. Switch to the system.

到達時間演算装置14は、流入下水流量の変動が検出さ
れると、流量及び曝気槽１の容積から、現在流入してい
る下水が、曝気槽１の出口部に到達するに必要な時間を
求める。所要曝気風量推定装置15は、流入下水流量の変
動が検出されると、流量及び記憶されている風量倍率か
ら、現在流入している下水が曝気槽出口部に到達した時
点で必要とされる曝気風量を、次式に基づいて推定す
る。When the fluctuation of the inflowing sewage flow rate is detected, the arrival time calculation device 14 determines the time required for the currently flowing sewage to reach the outlet of the aeration tank 1 from the flow rate and the volume of the aeration tank 1. . When the fluctuation of the inflowing sewage flow rate is detected, the required aeration air volume estimation device 15 determines, based on the flow rate and the stored air volume magnification, the aeration required at the time when the currently flowing sewage reaches the outlet of the aeration tank. The air volume is estimated based on the following equation.

必要曝気風量＝流入下水流量×風量倍率 なお、曝気槽１からの下水の流出は、満水になってい
る曝気槽１への下水の流入によって発生するものであ
り、曝気槽１内の流れを押し出し流水とすれば、曝気槽
１からの流出量は到達時間の演算には影響を与えないの
で考慮には入れていない。Required aeration air volume = inflow sewage flow rate x air volume magnification The sewage outflow from the aeration tank 1 is generated by the inflow of sewage into the aeration tank 1 that is full, and pushes out the flow in the aeration tank 1. In the case of flowing water, the amount of outflow from the aeration tank 1 is not taken into consideration because it does not affect the calculation of the arrival time.

曝気風量スケジュール装置16は、流入下水流量の変動
が検出されると、到達時間演算装置14で得られる到達時
間後に、現在の曝気風量から、所要曝気風量推定装置15
で推定される曝気風量へ移行するよう、設定曝気風量の
変更スケジュールを作成する。曝気風量設定装置17で
は、曝気風量変更スケジュールに従って、定期的に設定
風量値を出力する。When the fluctuation of the inflow sewage flow rate is detected, the aeration air volume schedule device 16 calculates the required aeration air volume estimation device 15 from the current aeration air volume after the arrival time obtained by the arrival time calculation device 14.
A change schedule of the set aeration air volume is created so as to shift to the aeration air volume estimated in (1). The aeration air volume setting device 17 periodically outputs the set air volume value according to the aeration air volume change schedule.

以上の装置を備えた本発明の制御装置の動作につい
て、曝気槽流入下水流量が安定している平常時と、下水
流量の変動が検出された変動時に分けて説明する。The operation of the control device of the present invention including the above-described device will be described separately for normal times when the flow rate of sewage flowing into the aeration tank is stable, and for changes in which a change in sewage flow rate is detected.

（１）平常時のDO一定制御 曝気槽流入下水流量が安定している平常時について
は、従来と同様の方法によってDO一定制御が実施され
る。(1) Normal DO constant control In normal times when the aeration tank inflow sewage flow rate is stable, DO constant control is performed by the same method as in the past.

すなわち、曝気槽１出口部のDO値が、DO計２によって
計測され、この計測値と設定DO値９を用い、DO調節計３
におけるPI演算によって、所要曝気風量が計算される。
次に、所要曝気風量は、設定曝気風量10として、風量調
節計４へ入力される。設定曝気風量10として、DO調節計
３からの出力を使用するか、あるいは曝気風量設定装置
17及び積分成分演算装置12からの出力を使用するかは、
流入下水流量の変動の有無によって出力される設定曝気
風量切替指令18によって決定される。平常時の場合、DO
調節計３からの出力が選択される。That is, the DO value at the outlet of the aeration tank 1 is measured by the DO meter 2, and using this measured value and the set DO value 9, the DO controller 3
, The required aeration air volume is calculated.
Next, the required aeration air volume is input to the air volume controller 4 as the set aeration air volume 10. Use the output from the DO controller 3 as the set aeration air volume 10, or use the aeration air volume setting device
Whether to use the output from 17 and the integral component arithmetic unit 12
It is determined by a set aeration air volume switching command 18 that is output depending on whether or not the inflow sewage flow rate has changed. In normal times, DO
The output from the controller 3 is selected.

次に風量調節計４では、風量計５による計測風量と、
設定曝気風量10から、風量調節用の電動弁６の操作量を
計算し、電動弁６に開閉操作指令を出力する。また、こ
の動作期間中は、風量計５で計測された曝気風量と曝気
槽流入下水流量計８で計測された流入量の比、すなわち
風量倍率が風量倍率記憶装置11に記憶される。Next, in the air volume controller 4, the air volume measured by the air volume meter 5,
From the set aeration air volume 10, the operation amount of the electric valve 6 for adjusting the air volume is calculated, and an open / close operation command is output to the electric valve 6. Also, during this operation period, the ratio of the aeration air volume measured by the air volume meter 5 to the inflow volume measured by the aeration tank inflow sewage flow meter 8, that is, the air volume magnification, is stored in the air volume magnification storage device 11.

このように、曝気槽流入下水流量が安定している平常
時については、従来と同様のDO一定制御が実施される。As described above, in a normal state where the flow rate of sewage flowing into the aeration tank is stable, the same DO constant control as in the related art is performed.

（２）曝気槽流入下水流量変動時のDO一定制御 一般に下水処理場に流入する下水流量は、深夜時間帯
では少なく、昼間の時間帯では多い。したがって、汚水
ポンプの運転台数も、これに対応した形で増減され、曝
気槽流入下水流量の変動が発生する。(2) DO constant control when the sewage flow rate in the aeration tank fluctuates In general, the sewage flow rate flowing into the sewage treatment plant is low during the late night hours and high during the daytime hours. Therefore, the number of operating sewage pumps is also increased / decreased in a manner corresponding to this, and fluctuations in the flow rate of sewage flowing into the aeration tank occur.

曝気槽流入下水流量の変動の検出は、曝気槽流入下水
流量計８の計測値に基づいて行われる。すなわち、第２
図に示すように、流入下水流量を毎分計測し、（ｎ−
ａ）時刻より現時刻ｎまでの平均流入下水流量Q2と、
（ｎ−ｃ）時刻より（ｎ−ｂ）時刻までの平均流入下水
流量Q1を求める。そして、Q1とQ2の差ΔＱの絶対値が、
設定値以上であれば、流入下水流量の変動が発生したと
して検出する。ここで設定値は、平常時のDO一定制御系
で対応可能な流量変動の最大値を基準に決定される。The detection of the fluctuation of the aeration tank inflow sewage flow rate is performed based on the measurement value of the aeration tank inflow sewage flowmeter 8. That is, the second
As shown in the figure, the inflow sewage flow rate was measured every minute, and (n-
and the average inflow sewage flow rate Q 2 of up to the current time n from a) time,
Determining the average inflow sewage flow to Q 1 from (n-c) time to (n-b) time. And the absolute value of the difference ΔQ between Q 1 and Q 2 is
If it is equal to or greater than the set value, it is detected that a change in the inflow sewage flow rate has occurred. Here, the set value is determined based on the maximum value of the flow rate variation that can be handled by the DO constant control system in normal times.

なお、（ｎ−ｂ）時刻より（ｎ−ａ）時刻までの流入
下水流量を除外したのは、台数変更による流量変化の過
渡的な部分を除くためである。In addition, the reason why the inflow sewage flow rate from the time (nb) to the time (na) is excluded is to remove a transient part of the flow rate change due to the change in the number.

曝気槽流入下水流量の変動が検出されると、到達時間
演算装置14では、（１）式に基づいて、その変動が曝気
槽１出口部へ到達する時間Ｈを演算する。When the fluctuation of the flow rate of the sewage flowing into the aeration tank is detected, the arrival time calculating device 14 calculates the time H during which the fluctuation reaches the outlet of the aeration tank 1 based on the equation (1).

Ｈ＝Vat/Q ・・・・・・・・・・（１） ただしVatは曝気槽１の容積、Ｑは変化後の曝気槽流
入下水流量であり、第２図中に示した（ｎ−ａ）時刻か
ら現時刻ｎまでの平均流入下水流量Q2を用いる。H = V at / Q (1) where V at is the volume of the aeration tank 1 and Q is the flow rate of sewage flowing into the aeration tank after the change, which is shown in FIG. 2 ( from n-a) time using the average inflow sewage flow Q 2 to the current time n.

また、所要曝気風量推定装置15では、風量倍率記憶装
置11に記憶されている風量倍率を用いて、（２）式によ
り所要風量AQを求める。In addition, the required aeration air volume estimation device 15 uses the air volume magnification stored in the air volume magnification storage device 11 to obtain the required air volume AQ by equation (2).

AQ＝KQ/Q ・・・・・・・・・（２） ただしKQは風量倍率、Ｑは（１）式と同じ変化後の曝
気槽流入下水流量である。AQ = K Q / Q (2) where K Q is the air volume magnification and Q is the flow rate of sewage flowing into the aeration tank after the same change as in equation (1).

次に、曝気風量スケジュール装置16では、現在の曝気
風量AQ0から、Ｈ時間後に曝気風量AQになるように、風
量変更のスケジュールが作成される。スケジュール作成
の一例として、下記のような方法が挙げられる。Next, the aeration air volume scheduling device 16 creates an air volume change schedule from the current aeration air volume AQ 0 so as to become the aeration air volume AQ after H hours. As an example of the schedule creation, the following method is given.

ｎ＝H/Tc ・・・・・・・・・（３） ΔAQ＝（AQ−AQ0）/n ・・・（４） AQi＝AQ0＋ｉ・ΔAQ ・・・・（５） ここでTcは、曝気風量設定装置17より出力される設定
風量の更新周期、ｉは更新回数である。この方法によれ
ば、設定曝気風量が等差数列的に変化するスケジュール
が作成される。n = H / T c (3) ΔAQ = (AQ−AQ 0 ) / n (4) AQi = AQ 0 + i · ΔAQ (5) where Tc is the update cycle of the set air volume output from the aeration air volume setting device 17, and i is the number of updates. According to this method, a schedule in which the set aeration air volume changes in an arithmetic progression is created.

曝気風量設定装置17では、曝気風量変更スケジュール
に基づき、一定時間毎にその出力値を更新する。The aeration air volume setting device 17 updates its output value at regular intervals based on the aeration air volume change schedule.

一方、積分成分演算装置12では、DO値が設定値に維持
されるよう、制定風量の補正量が（６）式によって算出
される。On the other hand, in the integral component calculation device 12, the correction amount of the established air volume is calculated by the equation (6) so that the DO value is maintained at the set value.

AQc＝Ki（DOSP−DOm） ・・・（６） ここで、AQcは補正風量、DOSPは設定DO値、DOmは計測
DO値、Kiは比例係数である。 AQ c = K i (DO SP -DO m) ··· (6) where, AQ c correction air volume, DO SP is set DO value, DO m is measured
The DO value, Ki, is a proportionality coefficient.

そして、曝気風量設定装置17からの出力AQiと、積分
成分演算装置12からの出力AQcを加算し、設定曝気風量1
0として、風量調節計４に入力する。Then, an output AQ i from the aeration air quantity setting device 17, an output AQ c from the integral component calculation unit 12 adds, set the aeration airflow 1
It is input to the air volume controller 4 as 0.

設定曝気風量10の出力源として、曝気風量設定装置17
及び積分成分演算装置12を選択する動作は、流入下水流
量の変動検出時に出力される設定曝気風量切替指令18に
よって実行される。As an output source of the set aeration air volume 10, the aeration air volume setting device 17
The operation of selecting the integral component calculation device 12 is executed by a set aeration air volume switching command 18 output when a change in the inflow sewage flow rate is detected.

風量調節計４において、計測値と設定値から、電動弁
６を操作する動作は、平常時と同様に行われる。In the air volume controller 4, the operation of operating the electric valve 6 based on the measured value and the set value is performed in the same manner as in normal times.

そして、流量変動の検出後、推定到達時間Ｈを経過す
ると、平常時のPI演算によるDO一定制御へと戻される。Then, when the estimated arrival time H elapses after the detection of the flow rate fluctuation, the control is returned to the constant DO control by the PI calculation in normal times.

〔発明の効果〕〔The invention's effect〕

以上に述べたように、本発明においては、曝気槽流入
下水流量の変動を検出し、予見的に、曝気風量を変更す
る制御を行う。これにより、曝気槽流入下水流量の変動
によって発生する曝気槽出口部DOの変動を抑制すること
ができる。この予見的な曝気風量の設定に際しては、設
定DO値と、計測値から、風量補正を行うので、計測値が
設定値から逸脱するおそれがない。また、風量倍率は常
に更新されているので、流入下水の水質の変化が生じて
も、所要風量の推定精度を高精度に保つことができる。As described above, in the present invention, control is performed to detect a change in the flow rate of sewage flowing into the aeration tank and change the aeration air volume in a foreseeable manner. Thereby, it is possible to suppress the fluctuation of the aeration tank outlet DO caused by the fluctuation of the aeration tank inflow sewage flow rate. In setting the foreseeable aeration air volume, the air volume is corrected from the set DO value and the measured value, so that the measured value does not deviate from the set value. Further, since the air volume magnification is constantly updated, even if the quality of the inflow sewage changes, the accuracy of estimating the required air volume can be kept high.

【図面の簡単な説明】 第１図は本発明の実施例の構成を示すブロック図、第２
図は汚水ポンプの運転と曝気槽流入下水流量との関係を
示すグラフ、第３図は従来の制御装置の構成を示すブロ
ック図である。 1:曝気槽、2:DO計 3:DO調節計、4:風量調節計 5:風量計、6:電動弁 7:ブロワ、8:曝気槽流入下水流量計 9:設定DO値、10:設定曝気風量 11:風量倍率記憶装置 12:積分成分演算装置 13:流入量変動検出装置 14:到達時間演算装置 15:所要曝気風量推定装置 16:曝気風量スケジュール装置 17:曝気風量設定装置 18:設定曝気風量切替指令BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG.
FIG. 3 is a graph showing the relationship between the operation of the sewage pump and the flow rate of sewage flowing into the aeration tank. FIG. 3 is a block diagram showing the configuration of a conventional control device. 1: Aeration tank, 2: DO meter 3: DO controller, 4: Air flow controller 5: Air flow meter, 6: Electric valve 7: Blower, 8: Aeration tank inflow sewage flow meter 9: Set DO value, 10: Set Aeration air volume 11: Air volume multiplication storage device 12: Integral component calculation device 13: Inflow variation detection device 14: Arrival time calculation device 15: Required aeration air volume estimation device 16: Aeration air volume schedule device 17: Aeration air volume setting device 18: Set aeration Air volume switching command

───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.6，ＤＢ名) C02F 3/12──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. 6 , DB name) C02F 3/12

Claims (1)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】曝気槽（１）内に設置されたDO計（２）を
検出端とし、曝気風量調節計（４）を操作端とするPI制
御装置と、前記曝気槽（１）内に流入する下水の時間当
たり流入量を計測する曝気槽流入下水流量計（８）と、
前記曝気槽流入下水流量計（８）で計測された曝気槽流
入下水流量の変動を検出する流入量変動検出装置（13）
と、前記流入量変動検出装置（13）で検出された流入量
の変動が前記DO計（２）の設置点へ到達する時間を曝気
槽（１）の容積Vat及び前記流入量変動検出装置（13）
で流入量の変動が検出された時点において、前記曝気槽
流入下水流量計（８）で計測された曝気槽流入下水流量
Ｑに基づいて算定する到達時間演算装置（14）と、曝気
槽流入下水流量計（８）の計測値と前記DO計（２）で計
測されたDO計測値が変動しない安定な状態での風量倍率
とを記憶する風量倍率記憶装置（11）と、該風量倍率記
憶装置（11）に記憶されている風量倍率及び曝気槽流入
下水流量から所要曝気風量を推定する所要曝気風量推定
装置（15）と、前記到達時間演算装置（14）によって算
定される到達時間後に前記風量倍率記憶装置（11）に記
憶されている風量倍率から算定される推定所要風量にな
るように曝気風量の変更予定を決定する曝気風量設定装
置（17）と、前記DO計（２）の計測値と設定DO値との偏
差から曝気風量の補正量を算定する積分成分演算装置
（12）とを備えたことを特徴とするDO制御装置。1. A PI controller having a DO meter (2) installed in an aeration tank (1) as a detection end and an aeration air volume controller (4) as an operation end, and a PI control device in the aeration tank (1). An aeration tank inflow sewage flow meter (8) for measuring the amount of inflow per hour of inflow sewage,
An inflow variation detecting device (13) for detecting a variation in the aeration tank inflow sewage flow rate measured by the aeration tank inflow sewage flowmeter (8).
When the flow rate fluctuation detection device (13) variation of the detected flow rate in said DO meter (2) of volume V at and the flow rate fluctuation detection device aeration tank time to reach to the installation point (1) (13)
A time-of-arrival calculation device (14) which calculates the variation of the inflow amount based on the aeration tank inflow sewage flow rate Q measured by the aeration tank inflow sewage flowmeter (8); An air volume magnification storage device (11) for storing a measured value of the flow meter (8) and an air volume magnification in a stable state where the DO measured value measured by the DO meter (2) does not fluctuate; A required aeration air volume estimation device (15) for estimating a required aeration air volume from the air volume magnification and the aeration tank inflow sewage flow stored in (11), and the air volume after the arrival time calculated by the arrival time calculation device (14) An aeration air volume setting device (17) for determining a change schedule of the aeration air volume to be an estimated required air volume calculated from the air volume magnification stored in the magnification storage device (11), and a measured value of the DO meter (2) From the deviation between the set DO value and the A DO control device comprising an integral component calculation device (12) for calculating.
JP1015868A 1989-01-24 1989-01-24 DO control device Expired - Fee Related JP2841409B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP1015868A JP2841409B2 (en) 1989-01-24 1989-01-24 DO control device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1015868A JP2841409B2 (en) 1989-01-24 1989-01-24 DO control device

Publications (2)

Publication Number Publication Date
JPH02194897A JPH02194897A (en) 1990-08-01
JP2841409B2 true JP2841409B2 (en) 1998-12-24

Family

ID=11900781

Family Applications (1)

Application Number Title Priority Date Filing Date
JP1015868A Expired - Fee Related JP2841409B2 (en) 1989-01-24 1989-01-24 DO control device

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Country Link
JP (1) JP2841409B2 (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5001659B2 (en) * 2007-01-04 2012-08-15 住重関西施設管理株式会社 Dissolved oxygen control device
JP5032164B2 (en) * 2007-03-12 2012-09-26 株式会社東芝 Sewage treatment system and measurement system
EP2164810B1 (en) * 2007-07-02 2011-05-18 Reinhard Boller Method of introducing oxygen into a process tank during biological treatment
JP5714355B2 (en) * 2011-02-21 2015-05-07 三機工業株式会社 Activated sludge treatment apparatus and treatment method thereof

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Publication number Publication date
JPH02194897A (en) 1990-08-01

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