JP2884997B2 - Operation support system for sewage treatment plant - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewage treatment plant operation support system for assisting an operator who manages a process.

[0002]

2. Description of the Related Art In processes such as water purification treatment and sewage treatment, measuring instruments are arranged at various places in order to grasp the process state. The online measuring instruments located in these places are very important information for monitoring the entire treatment plant. In these processes, measuring instruments have characteristics that fluctuate according to the incoming water quality due to fluctuations in the quality of the incoming water and disturbances such as typhoon rainfall, so the failure rate of the measuring instruments is higher than in other processes. In particular, since the sewage treatment process utilizes a microbial reaction, problems such as contamination of a measuring instrument are more serious than other processes. Since abnormalities of measuring instruments such as deterioration and breakage of the detection end, adhesion of foreign substances, and failure of the electrical system frequently occur, calibration and inspection of measuring instruments are periodically performed at the treatment plant to improve reliability. Strive to. For this purpose, many measuring instrument abnormality diagnosis techniques have been proposed. Specifically, based on the instantaneous values and time series values of the measuring instruments, the upper and lower limit checks on the electrical system and maintenance of the measuring instruments, the change speed check, and the pattern check are used for each measuring instrument. Is diagnosed, and a warning is issued to a measuring instrument that has been diagnosed as abnormal.

[0003]

In a water purification process or a sewage treatment process, an instrument uses abnormal data (for example,
Exceeding the upper limit) are caused by a failure or defect of the measuring instrument itself, by an abnormal inflow, or by a driving operation. Due to the slow response of these plants, the measuring instrument itself does not need to take immediate measures against abnormalities caused by failures or inadequacies, while abnormalities caused by abnormal inflow or operation We need to take immediate action to shock them. The conventional measuring instrument diagnosis technology could detect a measuring instrument showing abnormal data, but this measuring instrument itself can distinguish between abnormalities caused by failures and defects, abnormalities caused by abnormal inflow, and abnormalities caused by driving operation. could not. If similar guidance is given to the above abnormal phenomena, an inflow of an abnormality or an abnormality due to a driving operation is overlooked, and a problem such as a response delay occurs.

[0004] In view of the above circumstances, it is an object of the present invention to accurately and easily determine the information necessary for the operation management of an operator, and to further reflect an abnormality in a measuring instrument, an abnormality in inflow water quality, and an operation. And provide guidance to the operator,
Its support contents easy to understand for the operator, also is to provide a plant operation supporting system for sewage processing corresponding to the good operation management efficiency.

[0005]

In order to achieve the above object, a driving support system according to the present invention determines various abnormal phenomena using other process measurement data generated simultaneously with measurement data of a measuring instrument itself. Is what you do.

[0006] An apparatus capable of distinguishing and guiding abnormal phenomena is built in the main body of the support system and connected to a monitor capable of displaying a diagnosis result.

[0007]

According to the present invention, the information necessary for the operation management of the operator can be accurately and easily determined, and further, the abnormality of the measuring instrument can be detected.
An inlet water quality abnormality, and fractionated a reflection on the operation and guidance to the operator, easily understand the support contents for the operator, also possible to provide a driving support system of the sewage treatment plant which corresponds to a good operation management efficiency It is in.

[0008]

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an example of processing performed by a sewage plant and a central processing unit (CPU) to which the plant support system of the present invention is applied.

[0010] A sewage treatment plant usually comprises a plurality of lines capable of performing the same treatment. FIG. 1 shows an embodiment of a plant having two systems a and b.

In FIG. 1, inflow sewage is first settled in a settling basin 10.
After the large dust and the like are settled and removed at 0a and 100b, they flow into the aeration tanks 110a and 110b. Further, the aeration tanks 110a, 110
b is the sludge return pipe 16 from the final sedimentation basins 150a and 150b.
Returned sludge (microorganisms) is supplied via Oa and 160b. The aeration tanks 110a and 110b are provided with air pipes 130a and 130b from the blowers 140a and 140b.
Air blown through the air diffusers 120a, 120b
Is diffused by As a result, the returned sludge and the sewage supplied into the aeration tanks 110a and 110b are stirred and mixed. Returned sludge, that is, activated sludge, is a lump (floc) having a particle size of about 0.1 to 1.0 mm in which microorganisms are aggregated.
It contains dozens of microorganisms, but is roughly divided into cohesive microorganisms and filamentous microorganisms. Activated sludge absorbs oxygen in the supplied air and decomposes organic matter in the sewage to carbon dioxide and water. Some of the organic matter is used for cell growth of activated sludge. The mixed liquid of activated sludge and sewage is supplied to the final settling basin 150a,
It is led to 150b, where the activated sludge settles by gravity. The supernatant is usually discharged after chlorine sterilization. On the other hand, part of the settled sludge is returned to the aeration tanks 110a and 110b as returned sludge from the sludge return pipes 160a and 160b, and the other settled sludge is returned to the sludge discharge pipes 170a and 170a.
70b is discharged from the process as excess sludge.

[0012] The sewage inflow water quality measuring instrument 50 is provided with an inflow sewage amount,
Measure pH, SS, turbidity, etc. First sedimentation basin water quality measuring devices 105a and 105b measure pH, turbidity, SS, sludge interface, and the like. Aeration tank water quality meter 11
5a and 115b measure the DO concentration (dissolved oxygen concentration), MLSS, pH and the like in the tank. The final sedimentation basin water quality measuring devices 155a and 155b measure the pH and the sludge interface. The discharge water quality meter 60 measures pH, COD, and the like. These measuring instruments measure at regular time intervals and transmit the measurement data to the database 303.

Based on the relationship of the arrangement of measuring instruments in the plant shown in FIG. 1, the plant is classified into a series arrangement and a parallel arrangement. Sewage inflow water quality measuring device 50, a system measuring device (first sedimentation tank water quality measuring device 105a, aeration tank water quality measuring device 115
a, Final sedimentation basin water quality measuring instrument 155a) and discharge water quality measuring instrument 60 are arranged in series. Similarly, the sewage inflow water quality measuring instrument 50, the b-type measuring instrument, and the discharge water quality measuring instrument 60 also have a relationship of being arranged in series. On the other hand, measuring instruments of a system and b system
Each has a parallel arrangement relationship (for example, first settling basin water quality measuring instruments 105a and 105b).

The database 303 separates and stores the water quality data transmitted from the plant and the control information transmitted from the control device 500. The control device 500 executes the control mode set by the operator, and transmits the control mode to the database 303.

The central processing unit (CPU) 200 refers to the data in the database 303, makes a diagnosis of a measuring instrument abnormality, determines guidance based on the diagnosis result, and displays the guidance on a monitor (CRT) 302.

Here, the central processing unit (CP) according to the present invention
FIG. 2 shows a configuration diagram of U) 200 and peripheral devices.

In FIG. 2, the database 303 stores water quality information transmitted from measuring instruments disposed in various parts of the plant, control information transmitted from the control device 500, and the like. The CPU 200 is connected to the system bus 30
7, the database 303 is referred to, and a measurement device abnormality diagnosis is performed, and guidance is determined based on the diagnosis result. Information, programs, and the like necessary for processing performed by the CPU 200 are stored in the main memory 301 and the disk 304. Guidance from the CPU 200 is displayed on a monitor (CRT) 302 via a system bus. Usually, the operator monitors the process by a screen displayed on the monitor 302.

On the other hand, the display designation and change of the display location, display item, time, period, etc. of the guidance on the monitor 302 are as follows.
Monitor 3 by keyboard 305 or mouse 306
02.

Next, the processing performed by the central processing unit (CPU) 200 will be described with reference to FIG. Data collection unit 210
Collects the measurement data of a predetermined item from the current time and stores it in the main memory 301. Abnormality diagnosis unit 22 for each measuring instrument
At 0, it is checked whether or not the data of each measuring instrument is within a predetermined range. If the data is out of the predetermined range, it is determined that there is an abnormality, and the name of the measuring instrument is stored in the main memory 301. The predetermined range includes, for example, upper and lower limits of a measuring instrument, and the range is defined for each measuring instrument. In addition, the upper and lower limits include values obtained from statistical analysis or empirical values. The selection 230 of the causal instrument item is
With respect to the measuring instrument determined to be abnormal stored in the main memory 301, another related process measuring data which is generated simultaneously with the measuring data of the measuring instrument itself is selected. The causal relationship-based abnormality diagnosis unit 240 performs abnormality diagnosis based on a plurality of measurement data selected in the selection 230 of the measuring instrument item having the causal relationship.

An embodiment of the processing performed by the abnormality diagnosis unit 240 based on the causal relationship will be described with reference to FIGS. An object of the present invention is to separately diagnose an abnormality caused by a failure or defect of a measuring instrument itself, an abnormality caused by an abnormal inflow, and a process abnormality caused by a driving operation. First, a method for distinguishing an abnormality caused by a failure or defect of the measuring instrument itself from an abnormality caused by an abnormal inflow will be described using a pH meter as a specific example. An example is shown in FIG.

FIG. 5 (a) shows a trend graph of the pH meter in a normal state. FIG. 5B shows a trend graph of the pH meter at the time of abnormality. In this case, the data of the pH meter is outside the predetermined upper and lower limits. FIG. 5C shows a trend graph of a plurality of pH meters when an abnormal inflow occurs. In a plant having a plurality of series as shown in FIG.
When industrial wastewater with high H flows into a sewage plant,
The data of the inflow sewage pH meter 50 exceeds the upper limit. Then, after the residence time of the first sedimentation basin, the data of the first sedimentation basin pH meters 105a and 105b arranged in parallel simultaneously exceed the upper limit. That is, the inflow sewage p arranged in series
The H meter 50 and the first sedimentation basin pH meter 105a or the first sedimentation basin pH meter 105b show abnormalities sequentially after the residence time. On the other hand, the first settling basin pH meter 105
a and the first sedimentation basin pH meter 105b simultaneously show abnormalities. An example is shown in FIG.

Here, the abnormality shown in FIG. 5 is detected using the flowchart shown in FIG. First, step 231
Then, a measuring instrument item diagnosed as abnormal is fetched from the main memory 301. FIG. 3 shows an embodiment in which the “a-system first sedimentation basin pH meter” is diagnosed as abnormal. In step 232, other instrument data associated with the pH a first settling basin pH meter is selected. In this embodiment, the inflow sewage p
The H meter and the pH meter of the first settling tank of the b type are selected. Step 2
At 41, a branching process is performed depending on whether the measurement device is serial or parallel depending on the arrangement of the measuring instruments. If parallel, step 242 is executed. If serial, step 244 is executed. For example, since the system a first sedimentation basin pH meter and the system b first sedimentation basin pH meter are arranged in parallel, their data are read in step 242, and further, in step 243, the two data show abnormalities at the same time. Check if yes, and if yes,
When the abnormal signal 2 (there is a possibility of abnormal inflow) is “no”, the abnormal signal 1 (a system first sedimentation basin pH meter failure) is transmitted to the guidance determination unit 250. On the other hand, the first system
Since the H meter and the inflow sewage pH meter are arranged in series, their data are read in step 244. Further, in step 245, the two data are read in the order of the inflow sewage pH meter and the a-system first sedimentation tank pH meter. It is checked whether it indicates an abnormality. If "yes", an abnormal signal 2 (possible abnormal inflow) is provided, and if "no", an abnormal signal 1 (a system first sedimentation basin pH meter failure) is determined. To the unit 250.

The abnormality diagnosis method shown in FIGS. 3 and 5 is a method for diagnosing measuring instruments such as a turbidity meter, an SS meter, a COD, a pH meter, a turbidity meter, and an alkalinity meter for a water purification process, in addition to a pH meter for a sewage process. Also applicable to

Next, a method of distinguishing an abnormality due to a failure or defect of the measuring instrument itself from a process abnormality due to the driving operation will be described with a specific example of an air meter and a DO meter. The embodiment is shown in FIGS.

As shown in FIG. 1, the activated sludge absorbs oxygen supplied from the blowers 140a and 140b in an aeration tank 110 to decompose organic substances to form water and carbon dioxide. Therefore, there is a causal relationship between the amount of air supplied from the blower and the dissolved oxygen concentration (hereinafter abbreviated as DO) in the aeration tank 110. Normally, there are two types of control in the aeration tank 110: constant DO and constant air volume.

First, FIG. 6 shows an embodiment of a driving operation with a constant air amount.

FIG. 6A shows a trend graph of the air meter and the DO meter in a normal state. Due to the constant air amount operation, the data of the air meter fluctuates slightly within a predetermined range, and the data of the DO meter fluctuates greatly according to the fluctuation of the inflow water quality.
Here, it is desirable that the data of the DO meter is also within a predetermined range. FIG. 6B shows a trend graph when the air meter is normal and the DO meter is faulty. In this case, the data of the DO meter does not fluctuate despite the constant air amount operation. FIG. 6C shows a trend graph in which the air flow meter is abnormal. In this case, despite the constant air amount operation, the data of the air amount meter fluctuates beyond a predetermined range. FIG.
(D) shows a trend graph of the DO meter abnormality due to the driving operation. In this case, the data of the DO meter exceeds a predetermined range. However, this abnormal phenomenon is not caused by an abnormality of the DO meter, but by an improper set value of the air amount or an inappropriate operation method. Such a drastic change in DO adversely affects the growth of microorganisms, and is therefore undesirable for operation management. Therefore, when this abnormal phenomenon occurs, it must be dealt with immediately. As a response method,
Change the set value of the air amount or change the air amount
There is a change to a constant operation.

Next, FIG. 7 shows an embodiment of a constant DO operation.
Shown in

FIG. 7A shows a trend graph of the DO meter and the air meter at the time of normal operation. Due to the DO constant operation, the data of the DO meter fluctuates slightly within a predetermined range, and the data of the air meter fluctuates greatly according to the fluctuation of the inflow water quality. Here, it is desirable that the data of the air meter also be within a certain predetermined range. FIG. 7B shows a trend graph when the DO meter or the air meter is abnormal. In this case, the data of the DO meter exceeds the predetermined range despite the constant DO operation. Fig. 7 (b) As the cause of the abnormality, supply of a predetermined amount of air is necessary because the DO meter is out of order and it is not possible to measure the accurate DO concentration or an abnormality such as clogging of the air diffuser occurs. Is not possible. FIG. 7 (c)
Fig. 7 shows a trend graph of an air flow meter abnormality due to a driving operation. In this case, the data of the air meter exceeds a predetermined range. This is not an abnormality of the air flow meter but an abnormal phenomenon caused by an inappropriate setting value of DO or an inappropriate operation method. This abnormal phenomenon also has a bad influence on the growth of microorganisms as in the case of FIG. In particular,
If the air is supplied in excess, abnormal phenomena such as sludge floating, sludge dismantling, and sludge dispersion in the final sedimentation basin are likely to occur, and the quality of the discharged water will be deteriorated. As a corresponding method, there is a change in the set value of DO or a change from the DO constant operation to the air amount constant operation.

The abnormalities caused by the driving operation shown in FIGS. 6D and 7C are particularly likely to occur when the water quality fluctuates greatly, for example, when it rains, the season changes, or the year-end and New Year holidays.

Here, the abnormalities shown in FIGS. 6 and 7 are detected using the flowchart shown in FIG. First, in step 231, a measuring instrument item diagnosed as abnormal is fetched from the main memory 301. FIG. 4 shows an embodiment in which the "b-based aeration tank DO meter" is diagnosed as abnormal. In step 232, another measuring instrument related to the b-system aeration tank DO meter is selected. In this embodiment, a b-type aeration tank air meter is selected. Step 241
Then, the data of the b-type aeration tank DO meter and air meter are read. In step 242, a branching process is performed by a control operation.
In the case of the constant DO operation, step 246 is executed. In step 243, a branching process is performed depending on whether the data of the air flow meter fluctuates within a predetermined range, and if “no”, an abnormal signal 3 (air flow meter failure) is output to the guidance determination unit 2
50, and if “yes”, execute step 244. In step 244, branch processing is performed depending on whether the data of the DO meter is fluctuating. A signal 4 (DO meter failure) is transmitted to the guidance determination unit 250, and if "yes", furthermore,
Step 245 is executed. In step 245, DO
Data is within a predetermined range,
In the case of “no”, an abnormality signal 5 (DO meter abnormality due to driving operation) is transmitted to the guidance determination unit 250. On the other hand, in step 246, a branching process is performed depending on whether the data of the DO meter fluctuates within a predetermined range. If “no”, an abnormal signal 4 (DO meter failure) is transmitted to the guidance determination unit 250, and “ [yes], execute step 247.
In step 247, a branching process is performed depending on whether the data of the air meter has fluctuated. If “no”, the air flow meter does not fluctuate, so that an abnormal signal 3 (air flow meter failure) is transmitted to the guidance determination unit 250. If “yes”, step 248 is further executed. In step 248, it is determined whether the air amount data is within a predetermined range.
In the case of “no”, an abnormality signal 6 (air meter abnormality due to driving operation) is transmitted to the guidance determination unit 250.

The abnormality diagnosis method shown in FIGS.
Diagnosis of measuring instruments such as MLSS meter and return sludge meter, water amount and turbidity, water amount and pH, turbidity meter and rain gauge, pH meter and alkalinity meter of water purification process, in addition to air meter and DO meter of sewage process Can also be applied.

The guidance judging section 250 includes an abnormality diagnosing section 240 for each measuring instrument and an abnormality diagnosing section 240 based on a causal relationship.
Guidance is selected based on the abnormal signal transmitted from. For guidance selection, for example, for the abnormal signal 2 in FIG.
"There is a possibility that an abnormal inflow may occur instead of a measuring instrument. It is necessary to investigate the cause." For the abnormal signal 1, "Measuring instrument error, calibration and inspection required." For the abnormal signal 6, FIG. Rather, the DO set value must be adjusted. " The result of the guidance determination unit 250 is transmitted to the display editing unit 260 and stored in the database 303.

The display editing unit 260 includes a guidance determining unit 2
Reference is made to the signal transmitted from 50 and the data in the database 303 and displayed on the monitor (CRT) 303. Also,
The display editing unit 260 includes the keyboard 305 or the mouse 30
6 to display or change the display of the display location, display item, time, period, etc., and display guidance on the monitor 302.

An embodiment of the guidance of the display editing unit 260 is shown in FIGS.

FIG. 8 shows an example in which an alarm is displayed on the measurement device layout of the processing plant based on the abnormal signals shown in FIGS. For example, a normal measuring instrument is displayed in white, an abnormal measuring instrument is displayed in red, an abnormality caused by an abnormal inflow is displayed in yellow, and an abnormality caused by a driving operation is displayed in blue. The guidance in FIG. 8 can provide the operator with accurate process status.

The abnormality diagnosis is performed at regular time intervals, and the result is stored in a database. Furthermore, the keyboard 30
5 or the mouse 306 can be used to display the diagnosis result for a certain period. FIG. 9 shows an example of guidance for a certain period. When the date and time are designated, the database 303 is accessed, the display data is searched by the date and time, and the search result is displayed as a graph. The graph shows the trend data of the specified measuring instrument and the period during which the abnormality was diagnosed. The abnormal period is indicated by a dashed line above the graph. The abnormal period is displayed by different line types by classifying abnormalities due to a failure or defect in the measuring instrument itself, abnormalities due to abnormal inflow, and process abnormalities due to operation operation.

As described in the above embodiment, the operator can display the information necessary for determining the plant state accurately, at a glance, and display it in an easy-to-use form. The operator can accurately determine the state of the plant based on the information. In addition, since abnormal phenomena that need to be dealt with immediately can be monitored online, it is possible to respond quickly. It should be noted that the present invention is not applied only to a sewage treatment plant, and is applicable to any process using a measuring instrument.
For example, the present invention can be applied to processes such as a water purification process and a chemical reaction process.

[0039]

According to the present invention, it is possible to accurately and efficiently provide information necessary for an operator's judgment, to make it easier for an operator to understand, and to further reduce the burden on the operator. Further, the reliability of the measuring instrument data is improved, and efficient operation management of the plant by the computer can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a main part of an embodiment of the present invention in detail.

FIG. 2 is a configuration diagram showing one embodiment of the present invention.

FIG. 3 is a flowchart for explaining the operation of the present invention.

FIG. 4 is a flowchart for explaining the operation of the present invention.

FIG. 5 is a trend graph for explaining the present invention.

FIG. 6 is a trend graph for explaining the present invention.

FIG. 7 is a trend graph for explaining the present invention.

FIG. 8 is a diagram showing an example of a guidance display according to the present invention.

FIG. 9 is a diagram showing an example of a guidance display according to the present invention.

[Explanation of symbols]

100a, 100b: Inflow sewage is the first sedimentation basin, 110
a, 110b ... aeration tank, 120a, 12
0b: air diffuser, 130a, 130b: air tube, 140
a, 140b: blower, 150a, 150b: final settling tank, 160a, 160b: sludge return pipe, 200: central processing unit (CPU), 301: main memory, 302: monitor (CRT), 303: database, 304: disk 305: keyboard, 306: mouse.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI G06F 3/14 320 G06F 3/14 320C (72) Inventor Nobuyoshi Yamakoshi 5-2-1 Omikacho, Hitachi City, Ibaraki Prefecture Hitachi, Ltd. Inside the Omika Plant (72) Inventor Shoji Watanabe 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Inside Hitachi Research Laboratory, Hitachi, Ltd. (72) Misako Obuchi 7-1-1 Omika-cho, Hitachi City, Ibaraki Stock (72) Inventor Kenji Baba 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Hitachi, Ltd. Hitachi Research Laboratory (56) References JP 1-267799 (JP, A) JP Japanese Unexamined Patent Publication No. Hei 4-14697 (JP, A) Japanese Unexamined Patent Publication No. Hei 3-156508 (JP, A) Japanese Unexamined Patent Publication No. Hei 4-92998 (JP, A) Japanese Unexamined Patent Publication No. Hei 4-48217 (JP, A) JP-A-1-209520 (JP, A) JP-A-54-121379 (JP, A) JP-A-5-325073 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB G08B 31/00 B01J 19/00 C02F 3/12 G01D 21/00 G05B 23/02 301 G06F 3/14 320

Claims (1)

(57) [Claims] 1. A sewage treatment plant having a plurality of treatment systems including a first settling tank, an aeration tank and a final settling tank, wherein sewage is guided from a common inflow source to the plurality of treatment systems. First water quality measuring means for measuring the quality of inflow sewage flowing into the plurality of processing systems; second water quality measuring means for measuring the quality of sewage water for each of the plurality of processing systems; The first and second measurement values become abnormal in order using the first measurement value measured by the water quality measurement means and the second measurement value for each processing system measured by the second water quality measurement means, or An abnormality diagnosing means for diagnosing an inflow sewage abnormality or an abnormality of the water quality measuring means depending on whether the second measured values of the respective processing systems have become abnormal at the same time, and the measurement values of the first or second water quality measuring means are trended. display Operating the sewage treatment plant, comprising: a display device for displaying the measured value on the display device as a trend, and display editing means for displaying the period of the inflow sewage abnormality or the water quality measurement means abnormality in the trend display. Support system.