JPH024498A - Controlling device for methane producing equipment - Google Patents

Abstract

PURPOSE:To perform accurate operating control by erasing a time element from the time sequential data of the process signals and calculating the relation of the mutual process signals and comparing the feature with a knowledge base to infer it and deciding an operating controlling method. CONSTITUTION:In a controlling device 1, respective process signals of a methane producing equipment 6 are inputted via an input terminal 7 and stored time sequentially in a data storage part and a time element is erased from the time sequential data in an analysis part 3. Furthermore the time element is erased even in 1st-order time differential signal of the process signals and the relation of the mutual process signals is calculated. Then the feature between the mutual process signals is compared with the knowledge data of a knowledge base 4 and inferred in an inference part 5 and a necessary operating controlling method is decided and indicated on an indicator 9 via an interface part 8 and also the operating control of the equipment 6 is performed via an operation output terminal 10. By such a way, accurate operating control excellent in the follow-up ability can be performed.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention relates to a control device for a methane production device that anaerobically treats organic wastewater, and in particular to a control device for controlling time series data of two or more types of signals. The present invention relates to a control device for a methane production device that can understand the operating state of the methane production device by analyzing interrelationships and instruct necessary operation management methods.

(Conventional technology) Anaerobically treating sewage and industrial wastewater and producing methane gas, which has high utility value as fuel, through methane fermentation is a promising method that is expected to reduce treatment costs and reduce the amount of sludge generated. It is a great technology.

In the methane fermentation that takes place, the methane bacteria that control this fermentation are obligate anaerobic bacteria and therefore dislike air contamination, and the gas generated is flammable, so the entire system must be sealed. Must be.

Therefore, it is very difficult to monitor the fermentation status compared to conventional aerobic and facultative devices.

Therefore, methane! 3! The flow rate and organic matter concentration of wastewater flowing into the drainage equipment, the amount of gas generated and its composition,
Furthermore, a mathematical model has been used to detect the quality of water flowing out from the treatment switch and use these values to analyze the state of the biochemical reactions occurring inside the methane production equipment.

(Problem to be solved by the invention) However, the biochemical reactions that can be calculated using mathematical models are extremely limited, and the types of water quality factors that can be detected are also limited, such as pH and ORP. As a process measuring instrument, it is low compared to those for condyle and aerobic processing, and the control accuracy of the control system using a mathematical model is extremely low, making it almost impossible to put it into practical use.

For this reason, the operational management of methane production equipment has traditionally been left to management methods based on the operator's long experience, rather than the control systems described above, and manual operation has therefore been the main method. The appearance of a control device for a certain methane production facility was desired.

By the way, a reliable signal that can be obtained from a methane production device is a signal related to flow rate rather than a signal related to water quality, and among flow rate signals, the inflow flow rate (hereinafter referred to as inflow amount) of wastewater such as sewage and wastewater is important. The outflow amount of generated gas (hereinafter referred to as gas flow rate) is a signal that can be easily and stably obtained over a long period of time.

Therefore, the inventor focused on a control system that uses these stably obtained flow rate signals of a methane production apparatus as an input signal, and attempted to develop it.

- Numerically speaking, the relationship between the inflow amount and the gas flow rate is an important monitoring item in the current manual management method for methane production equipment. In other words, the operators of methane production equipment (experts) have accumulated norms relating to each other regarding the characteristics of the inflow amount and the response characteristics of the gas flow rate through experience, and operate in accordance with these norms on a daily basis. is in charge of operational management.

However, the norms that experts adhere to often differ from person to person, and the terminology used may not be the same. Therefore, conventional manual operation management is practical but not systematic, and although professional, it lacks objectivity.

Furthermore, there was the problem that the judgment varied depending on the type of methane production equipment, the scale of the equipment, and the characteristics of the wastewater.

This invention was made in view of the problems of the conventional control device for methane production equipment, and it provides reliable signals that are important in the conventional empirical management method of inflow amount and gas flow rate. By utilizing the time series data of
A methane system that analyzes the interrelationships of multiple signals, including different types of signals, extracts characteristics, and finds the optimal operation management method by comparing the characteristics with the experiential knowledge of the operator (-expert). The purpose is to provide a control device for manufacturing equipment.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a control device for a methane production device that performs anaerobic treatment on organic wastewater such as urban sewage or industrial wastewater and recovers it as methane gas. a data storage unit that stores time series data of a plurality of signals including both signals related to fluid flowing into the fluid and signals related to fluid flowing out;
an analysis unit that extracts process characteristics from correlations obtained by erasing time elements from the plurality of signals stored in the data storage unit; and mutual rA characteristics of the plurality of signals and operational management of the methane production equipment. The system includes a knowledge base that determines a causal relationship with a method, and an inference section that determines an operation management method based on the analysis result of the analysis section and the knowledge base.

(Function) Generally, when signals from a process such as a methane production device are used in a control system that uses the experiential knowledge of experts, the time-series signals are often analyzed using various methods, and the analysis results are used to control the translated into knowledge of the processes in the system.

Therefore, in the control device for the methane production device of the present invention, two
The interrelationship of time series data of more than one type of signal is described by eliminating the common variable of both, time.

That is, the time series signal XY is expressed as follows. In order to eliminate the time element from these data, (X.

This can be realized by expressing it graphically by plotting y)=(F(t), G(t)).

The nature of this graphic reflects the state of the process and is directly related to the method of operation.

Therefore, by extracting characteristics from this diagram and comparing them with the knowledge base obtained from the experiential knowledge of experts, it is possible to understand the operating status of the process and automatically find the necessary operation management method. can.

(Example) Hereinafter, embodiments of the present invention will be explained in detail based on the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention,
The control device 1 includes a data storage section 2, an analysis section 3, a knowledge base 4, and an inference section 5.

Data input @ 7 from the methane production device 6 provides data to the data storage section 2 . Further, the output of the inference section 5 is sent to the display device 9 via the interface section 8.
and at the same time the operation output terminal 10 of the methane production device 6
It is connected to the.

As shown in FIG. 2, the analysis section 3 includes a diagramming circuit 11 and an attribute value calculation circuit 12 that extracts attribute values of the methane production apparatus 6 based on diagram information from the diagramming circuit 11. and,
The attribute parameter storage circuit 13 provides attribute parameters to the attribute value calculation circuit 12.

The operation of the control device for the methane production apparatus having the above configuration will be described next.

The control device 1 receives an inflow amount signal of waste water flowing into the methane production device 6 from the methane production device 6 via an input end 7 and an emission amount signal of methane gas generated in the methane production device 6, and stores the data in the data storage unit. 2 is stored as time series data of the methane production device 6.

Next, in the analysis section 3, a characteristic list representing characteristics of the interrelationship between input and output signals is generated from the above-mentioned time series data in accordance with a procedure described later.

This feature list is sent to the knowledge base 4 and modifies the knowledge data stored in the knowledge base 4.

This corrected knowledge data in the knowledge base 4 is referred to by the inference unit 5 and subjected to symbolic processing to determine the optimal operation management method for controlling the methane production device 6.

The details of the operation management method determined by the inference section 5 are provided to the display device and the operation output terminal 10 via the interface section 8 as an output of the control device 1.

Through such inference operations, the optimal operation management method is automatically determined based on the time-series data taken into the control device 1. A detailed explanation is as shown in FIG.

The analysis section 3 in FIG. 2 reads the time series data (F(t), 'G(t)) of at least two types of process signals stored in the data storage section 2 shown in FIG. It is input to the diagramming circuit 11.

In the diagramming circuit 11, the two types of time series data are each normalized according to the following equations.

F(t) T x(t) ... (2) σ X G(t) - YT y(t) ... (3) σ y Here, F(t) and G(t) are time series data ,σX,σ
y is standard deviation, X", Y" is time series data F (t)
, G (t) during period T.

Next, the standardized time series data x(t), y(1) are
It is converted into time difference time series data according to the following formula.

Large (t)-x (t) -x (t-1)
... (4)9 (t)=y (t) -y
(t-1) ... (5) Here, t, t-1,
t-2,... is the sampling time, large (t) 1 sentence (1
) indicates time difference time series data.

Furthermore, the standardized process signal (x, y) and its first-order time difference signal (large, 9) are respectively shown in Fig. 3(a).
) and (b), it is expressed as a diagram showing the interrelationships with time elements removed.

The time-series data diagrams in FIGS. 3(a) and 3(b) use hourly signals over a 24-hour period as the period T.

The diagram obtained in this way is then transmitted to the attribute value calculation circuit 12.

In the attribute value calculation circuit 12, the attribute parameter storage circuit 13
In the step, the values of the attribute parameters defined in advance are calculated.

The calculation result is as shown in FIG. 4, and is output as a feature list.

The feature list generated in this way represents the features of the methane production device 6 during period 1' as a set of pairs of attributes and attribute values, and the inference unit 5 The data is compared with the knowledge data in the knowledge base 4 through inference calculations, and is used to determine the operation management method for the methane production equipment 6.

The knowledge base 4 stores knowledge data that predetermines the relationship between the above attribute list in the 'feature list' in FIG. 4 and the operation management index.

The operation management index of the methane production device 6 determined by the inference of the inference unit 5 is output from the control device 1, and is based on the content of the decision in the inference unit 5, the knowledge data in the knowledge base 4 used for the inference, and the inference. The route etc. are displayed on the display unit 9 to notify the operator, and the contents of the determined operation management index are transmitted to the operation output terminal 10 of the methane production device 6.

Here, an example of a rule for determining an operation management method by inference operation based on a comparison between the attribute list of the feature list and the knowledge data in the knowledge base 4 is as follows.

RULE 0VERLOAD IP (line diagram xy - ellipse), and (average value The shape of the line diagram in Figure (a) is an ellipse, the average value of the treated water amount If the area of the figure is level - (3) of the predetermined series, a lot of sludge has accumulated in the methane production device 6 in Figure 1, so one quarter (25% ) must be removed, the operation management method is output.

In this way, the time element is removed from at least two types of process signals including the inflow amount signal of wastewater to the methane production device 6 and the outflow amount signal of methane gas generated in the methane production device 6, and The mutual relationship is determined by deleting the time element of the first-order time difference value, and a feature list is extracted.

Then, by comparing the obtained feature list with the knowledge data of Knowledge Base 4, it is possible to instruct the necessary operation management method, and it is possible to automatically determine the appropriate operation management method that is close to the judgment of experts. It is.

Incidentally, in the above embodiment, a correlation is obtained between two types of process signals: the inflow amount signal of waste water flowing into the methane production device 6 and the discharge amount signal of methane gas generated within the methane production device 6. It goes without saying that it is also possible to eliminate the time elements of three or more types of process signals, find their mutual relationships, create a feature list, and determine the operation management method.

[Effects of the Invention] As described above, according to the present invention, the time element is removed from the time-series data of the process signals of the methane production equipment, the relationship between the process signals is determined, and the characteristics of the mutual relationship are compared with the knowledge base. Since the system makes inferences and determines the necessary operation management method, judgments similar to those based on the experience of experts can be automatically executed, and extremely accurate operation management can be performed.

Furthermore, if the time element of the first-order time difference signal of the process signal of the methane production equipment is removed, the relationship between the process signals is determined, and the process signal is compared with the knowledge base to make inferences and determine the operation management method. , it is possible to perform operational management with good followability even to large changes in the operating status of the methane production equipment.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is a block diagram showing the detailed configuration of the analysis section in the above embodiment, Fig. 3 is a characteristic diagram obtained by the above embodiment, and Fig. 4 is an ellipse diagram of the feature list obtained in the above embodiment. 1...Control device 2...Data storage unit 3...
- Analysis section 4... Knowledge storage section 5... 4I theory section 6... Methane production device 11... Diagramming circuit 12... Attribute value calculation circuit 13... Attribute parameter storage circuit

Claims (3)

[Claims] (1) In a control device for a methane production equipment that performs anaerobic treatment on organic wastewater such as urban sewage or industrial wastewater and recovers it as methane gas, both a signal related to the fluid flowing into the methane production equipment and a signal related to the fluid flowing out of the methane production equipment are transmitted. a data storage unit that stores time-series data of a plurality of signals including: an analysis unit that extracts process characteristics from correlations obtained by erasing time elements from the plurality of signals stored in the data storage unit; a knowledge base that determines a causal relationship between characteristics of the interrelationships of the plurality of signals and an operation management method for the methane production equipment; and an inference unit that determines an operation management method based on the analysis results of the analysis unit and the knowledge base. A control device for a methane production device comprising: (2) The time-series data stored in the data storage unit includes an inflow amount signal of organic wastewater and an emission amount signal of methane gas generated in the methane production device.
A control device for the methane production device described above. (3) A claim characterized in that the time-series data is a first-order time difference signal between a signal regarding the amount of fluid flowing into the methane production device and a signal regarding the amount of fluid discharged from the methane production device. Item 3. A control device for a methane production device according to item 1 or 2.