JP2518753B2 - Blast furnace charge distribution control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for controlling a local gas flow to stabilize a gas flow distribution and an operation by controlling a charge distribution in a circumferential direction in a blast furnace. .

[0002]

2. Description of the Related Art FIG. 14 is a diagram showing the distribution control of the charge and the state inside the furnace, and Table 1 is a table showing the position and shape of the melting zone and the operating state.

[0003]

[Table 1]

Generally, a reducing gas (hereinafter referred to as a gas) generated by the combustion of coke flows mainly in the central portion of the blast furnace, which is the central flow, a large amount of the reducing gas flowing in the furnace wall portion, which is the peripheral flow, and a large amount of which flows locally. This is called local flow. Usually, coke has a larger grain size than ore as a raw material to be charged into a blast furnace, and since coke does not undergo reduction pulverization, coke has better air permeability. Further, in the zone where the ore melts (hereinafter referred to as the melting zone), the ventilation resistance of the ore layer is 200 to 300 times that of the coke layer, and the gas passes through the coke layer (the coke layer in the melting zone is hereinafter referred to as the slit). Flowing.

When a large amount of coke is charged in the center of the blast furnace, it becomes a central flow, the shape of the melting zone becomes Mt. Fuji, the number of slits increases, and the gas flow becomes stable. In addition, when a large amount of coke is charged into the furnace wall, it becomes a peripheral flow, which is said to be useful for removing deposits on the furnace wall. However, when a large amount of gas locally flows, it becomes a local flow, which causes a sudden abnormal reactor condition such as blow-through and slip. Therefore, for stable operation, control the charge distribution to stabilize the gas flow,
Furthermore, by detecting the occurrence of local flow, M
It is necessary to prevent local flow growth by taking A action.

In the case of a bell type blast furnace, charging of raw materials is performed by opening and closing a large bell. One large bell opening / closing operation is called a batch, and the coke and the ore are charged in several batches (for example, 2 batches of the coke and 3 batches of the ore). This is called 5 batch charging, and 5 batches are collectively called 1 charge. In normal operation, the charging interval is about 10 minutes.

FIG. 15 is a diagram showing the installation status of the MA.
(A) is the top view, (b) is a side view. In order to control the landing position of the raw material that falls freely from the large bell, about 20 MAs are installed evenly in the circumferential direction in the blast furnace.
The MA stroke can be moved from the furnace wall toward the center. Then, the distribution control of the charge is performed by changing the stroke of the MA in batch units with the charge as a cycle.

Regarding the relationship between the MA and the distribution of the charge,
For example, it is disclosed in "Materials and Processes (1) 1988, p74". However, the content is a formulation of the relationship between MA action and charge distribution based on the results of intermittent measurement of layer thickness distribution of coke and ore in the furnace with a sonde or the results obtained from outdoor model experiments. However, a consistent system technology for determining the MA action amount from the intensity and transition tendency of the gas flow in actual operation and controlling the MA to optimize the gas flow distribution has not yet been established. Further, a technique for predicting blow-through or slip based on sensor information is disclosed in, for example, Japanese Patent Laid-Open No. 62-270712. However, this was a system aimed at predicting blow through and slip, and was not a consistent system aimed at optimizing the gas flow distribution in the blast furnace. Further, the blast furnace charge distribution control device proposed by the present applicant in Japanese Patent Application No. 3-147627 focuses on the central flow and the peripheral flow, not the local flow.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of such a situation, and the strength and transition tendency of the gas flow in the furnace of the blast furnace, charging and reducing wind, MA operation history, Taking into consideration the operating conditions such as tapping situation, the MA action amount for optimizing the gas flow distribution in the circumferential direction in the furnace is determined,
An object of the present invention is to provide a blast furnace charge distribution control device that can be automatically controlled.

[0010]

A blast furnace charge distribution control apparatus according to one aspect of the present invention includes a knowledge base in which various kinds of knowledge about blast furnace operation obtained through operating experience and model experiments are registered, and a blast furnace. Means for fetching data from various sensors installed at a predetermined period, means for removing noise included in the fetched data, and knowledge base and circumferential direction for each sensor based on the noise-removed data With an inference means for inferring the strength and the transition tendency of the gas flow corresponding to the positions of a plurality of MAs arranged along the line, and an operation file in which the operation information in the blast furnace operation and the tapping information are fetched and stored as needed. , A synthesizing means for synthesizing the inference result as the strength and the transition tendency of the gas flow corresponding to the position of MA based on the information and knowledge base stored in the operation file, Strength and transition tendency of the gas flow are divided into a plurality of stages, and a matrix is formed by the strength and the transition tendency of the gas flow. As a component of the matrix, the manipulated variable of MA corresponding to the strength and transition tendency of the gas flow. Is stored in the storage means for storing the MA action decision matrix, and the synthesis result by the synthesis means is M
Applying to the A action decision matrix, the individual M
It has means for determining the change operation amount of A and means for obtaining the drive amount based on the change operation amount of MA and transmitting the drive amount to the drive control device of the MA to control the MA. In the blast furnace charging distribution control device according to another aspect of the present invention, in the above device, at least an operation history of MA and operation information associated with its history are stored in an operation file, and
It further has a correction unit that corrects the drive amount of the MA based on the operation information, and a teaching unit that outputs the corrected drive amount of the MA by video or audio.

[0011]

According to the present invention, the knowledge about the blast furnace operation obtained through the operation experience and the model experiment is registered in the knowledge base. The blast furnace is continuously used for 10 to 15 years once it has been put into operation. However, the knowledge about the operation of the blast furnace during this period is not the same or fixed. In order to effectively operate the system in response to operational changes such as deterioration of the charged raw materials and attempts to use new raw materials, register the newly acquired knowledge in the knowledge base and update the knowledge. Go. Knowledge of this blast furnace can be gained through operational experience and model experiments. What can be obtained by operating experience is, for example, when performing blast furnace operation in a raw material distribution shape made by charging various raw material brands and charging weights into the furnace at a plurality of types of MA stop positions,
There are good and bad results of blast furnace operation at that time and the state of gas flow in the furnace. As a model experiment, for example, a small blast furnace 1/10 the size of an actual blast furnace (room temperature is normal because hot air is not sent) was created, and charging of multiple raw materials and MA operation were performed in combination. There are findings obtained by experimentally verifying the distribution shape of the raw materials. On the other hand, data from various sensors installed in the blast furnace is taken in, for example, a process computer at a predetermined cycle. Then, the noise included in the acquired data is removed, and the intensity and transition tendency of the gas flow are inferred for each sensor for the noise-removed data based on the knowledge of the knowledge-based blast furnace operation. The inference result is used as operational information (for example, charging waiting, wind reduction, current MA position,
Based on the information about the operating state and operating parameters such as the current mixture ratio of raw materials) and the knowledge base, for example, the knowledge of the local flow, it is synthesized as the strength and transition tendency of the gas flow corresponding to the position of MA, and the synthesis result is operated. Apply to MA action decision matrix made by experience and model experiment,
The change operation amount (: MA action) of A is determined, the drive amount is determined based on the change operation amount, MA is driven based on the drive amount, and the charging raw material is charged into the furnace. Further, the drive amount of the MA is added with the operation history of the MA and the operation information associated with the operation history (for example, a change in blast pressure, a change in composition, or a transient element associated with a change in operation specifications). to correct. Then, the corrected drive amount of MA is M
It is transmitted to the drive control device of A, for example, a programmable controller (hereinafter referred to as PLC) to control the MA. Further, the corrected MA drive amount is displayed or voice output to guide the operator.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a conceptual diagram of a blast furnace charge distribution control device according to an embodiment of the present invention. In the figure, 10 is a blast furnace, and a fixed sonde (measuring temperature and components) and a shaft thermometer are installed in the circumferential direction on the upper part of the furnace wall. Further, various sensors such as a furnace mouth TV (measured with the temperature distribution on the surface of the charge as a surface) and MAs are installed at the furnace top.

Reference numeral 20 is a process computer conventionally used for controlling a blast furnace. The process computer 20 includes means 21 for taking data from various sensors installed in the blast furnace at a predetermined cycle, means 22 for removing noise included in the taken data, charging waiting and reducing wind 23,
A file means 26 for loading and saving information such as the operation history 24 of the MA and the tapping situation 25 at any time, a means 27 for guiding an operator of an inference result or a process, and a guidance result sent to the PLC 40 to automatically control the MA. Means 28
And means 29 for transmitting the data possessed by the process computer to the knowledge processing computer 30 and receiving the result of the knowledge processing, which are realized by the system program.

Reference numeral 30 denotes a knowledge processing computer, which registers and corrects knowledge about the operation of the blast furnace as a knowledge base 31, and the intensity of the gas flow for each sensor based on the data received from the process computer 20 and the knowledge base 31. Means 32 for inferring as a transition tendency, means 33 for synthesizing the result as intensity of gas flow corresponding to the position of MA and a transition tendency based on information about charging and wind reduction and a knowledge base, and a synthesis result Is applied to an MA action decision matrix created by a model experiment or the like, and means 34 for determining the individual MA action amount and means for correcting this MA action amount in consideration of factors associated with the operation history of the MA, etc. 35, means 36 for making an action execution decision by taking into account the pig iron information, and the data necessary for inference. Received from data 20, it has built-in means 37 to be transmitted to the process computer inference results, which are realized from the system program.

As described above, the apparatus is divided into the process computer 20 and the knowledge processing computer 30.
This is because there is a part to be processed by the conventional system technology and a part to be processed by the artificial intelligence application technology, and it is convenient for the system development to divide these parts, which is not essential to the present invention. Therefore, if one computer is logically divided and both means are realized, it can be realized by one computer.

(1) Preprocessing Method Various sensor data are taken in at a predetermined cycle by the constant cycle processing function of the process computer 20, and the file 2
After storing in 11, remove the noise contained in the data,
Pre-processing is performed to extract meaningful information as control information. In the pre-processing, the type of sensor and the state of noise included in the sensor data are taken into consideration, and data processing is performed by methods such as exponential smoothing and linear regression in order to make the data effective for gas flow determination.

A. Exponential smoothing

[Number 1] Sn = (1-1 / t) × S n-1 + R n / t S n: value after exponential smoothing in time n S _n-1: after exponential smoothing at time n-1 of the value R _n : Value before exponential smoothing at time n t: fixed for each sensor with time constant 1 ≤ t n, t unit is minute

B. Primary regression

[0019]

[Equation 2]

Τ ≦ ti ≦ o: reference point is inference execution time τ: time constant n: number of valid data Xo: linear regression data Sn or Xo is used to judge the strength and transition tendency of the gas flow.

(2) Judgment of Gas Flow Strength The preprocessing result is sent to the knowledge computer 30, and the strength of the gas flow corresponding to the position of MA is judged based on the reference value learned and controlled for each sensor. Below is an example of how to determine the reference value and how to determine the strength of the gas flow.

(2-1) How to determine the reference value The reference value is determined using the exponential smoothing method based on the daily average value,
It is designed so that it can easily respond to changes over time in equipment and operations.

[0023]

(Equation 3)

The exponential smoothed number α (0 ≦ α ≦ 1) is a function of the charging waiting time, the wind reduction time, the number of MA actions, and the charging waiting time, the wind reduction time, and the number of MA actions. Are expressed by the functions shown in (a) to (c) of FIG. 2 based on the operation experience and the offline experiment, and the special operation factor is removed.

[0025]

## EQU00004 ## α = α1 × α2 × α3 α1 = f (charging waiting time), α2 = f (wind reduction time), α3
= F (number of MA actions) Where, charging waiting time (interval between charging and next charging)
Is calculated by the following formula, targeting those whose waiting time is longer than the average charging waiting time.

[0026]

(Equation 5)

The wind reduction time (the time when the air flow rate is reduced from the target air flow rate) is empirically calculated by the following formula based on the time when the air flow is reduced and the air flow rate.

[0028]

(Equation 6)

(2-2) Judgment of Gas Flow Strength A furnace TV or a fixed sonde can be used to judge the gas flow corresponding to the position of MA. FIG. 3 shows the relationship between the gas flow intensity and the gas temperature and components. Generally, when the gas flow is strong, the gas temperature is high and the gas utilization rate (CO2 / CO) is low.

(2-2-1) Furnace TV (Fig. 4) The furnace TV continuously measures the temperature distribution on the surface of the charge as a thermal image at the furnace top. FIG. 4A shows raw data measured by the furnace entrance TV when the charging surface of the blast furnace is viewed from directly above. The charging surface temperature gradually rises after charging is completed,
Maximum before the next charge begins. In addition, the surface temperature of the charged material cannot be accurately captured immediately after charging due to dust generation. Therefore, after 4 to 5 minutes after charging, the data corresponding to the position of MA is equally divided in the circumferential direction according to the number of MA based on the thermal image, and based on the weighted average value of the temperature of the peripheral portion. ((B) of FIG. 4) is made to determine the gas flow in the circumferential direction. For example, FIG. 4B shows that the gas flow on the north side is strong. here,

[0031]

ΔXi = Xi−X Xi: average value of charging material surface temperature corresponding to the position of MA X: average value of charging material surface temperature X is calculated as the average of Xi.

(2-2-2) Fixed sonde temperature (FIG. 5) The installation state of the fixed sonde is shown in FIG. 5 (a), and the measured data is shown in FIG. 5 (b). A plurality of fixed sondes are installed in the furnace wall above the shaft of the blast furnace in the circumferential direction (sometimes several steps in the vertical direction) to measure the gas temperature and composition inside the charge. Therefore, if the relationship between the measurement position and the position of MA is taken into consideration in consideration of the distribution in one circumferential direction, it can be converted into data corresponding to the position of MA by a linear regression equation or the like to determine the gas flow corresponding to the position of MA. Available for For example, FIG. 5B shows that the gas flow on the north side is strong. here,

[0033]

(Equation 8) And X is calculated as the average of Xi. The measurement data of the fixed sonde can also be used for the analysis of gas components, and if this value is used, it can be used for the determination of the local flow in the same manner as the temperature data.

(2-2-3) Others A plurality of shafts are installed in the circumferential direction of the furnace wall and in the vertical direction, and the temperature inside the brick of the furnace wall is continuously measured. For this reason, it can be used to determine the local flow in the same manner as the fixed sonde temperature. However, since the gas temperature is not measured directly, the accuracy of the information is lower than that of the fixed sonde.

(2-3) Determination of Transition Trend of Local Flow For the transition tendency of gas flow, the time-series transition of sensor information used for determination of gas flow intensity can be used as it is. For example, when the temperature at a specific point tends to rise due to the surface temperature of the charging material or the temperature of the fixed sonde measured by the furnace TV, it indicates that the local flow is growing. FIG. 6 shows an example of determining the tendency of the gas flow transition depending on the fixed sonde temperature. From this figure, it can be seen that the gas flow is growing on the north side.

(3) Synthesis of intensity of local flow and trend of change The sensor data largely changes depending on the installation condition and operation condition (charging standby, wind reduction, etc.). Also, furnace TV and fixed sonde temperature show almost the same tendency, but there are differences in measurement accuracy. Therefore, when making a final decision on the gas flow, it is necessary to systematize these factors properly. Here, a highly accurate device is realized as follows.

(3-1) Synthesis Method Table 2 shows sensor data used for synthesis. In Table 2, the larger the O mark (smaller Q), the stronger the strength and transition tendency. In the synthesis, first, the sensor data is linearly regressed as shown in FIG. 7 to be converted into data corresponding to the position of MA, and then the sensor data is synthesized by the following equation.

[0038]

[Table 2]

[0039]

[Equation 9]

(3-2) Standardization of combined result In order to carry out control with this device as close as possible to the operating experience of the operator, the combined value in the paragraph (3-1) is standardized to a level of 1-5. I decided to do it. An example of standardization is shown in FIG. This equipment has a judgment reference value k based on the operation experience.
1, k2, k3, k4 are decided and the judgment is made in 5 steps of 1-5. Numerical values in FIG. 8A indicate the following states. 1: Very weak, 2: Weak, 3: Good, 4: Strong, 5: Very strong In addition, it is judged by expressing with a function as shown in FIG. It is obvious that a finer judgment can be made if this is done, but a judgment method close to that of the operator is adopted here.

(3-4) Inference of the amount of change in MA pattern For example, the raw material charging method for a bell-type blast furnace is controlled by a charge that is one cycle of a batch, which is one large bell opening / closing operation. The stroke of each batch in this charging is called a pattern, and for example, the pattern N in FIG.
In o.1, 1 charge consists of 5 batches, and each batch contains C charge / 150mm, C charge / 900mm, O charge / 560mm, O
Charge / 1000mm, O charge / 880mm. The amount of change in this MA pattern is inferred using the MA action decision matrix (FIG. 9) determined based on operating experience and model experiments. For example, if the intensity of the gas flow at a point corresponding to a certain MA is “2” and the intensity of the transition tendency is also “2”, the value of the MA action determination matrix is “+2”. This is the current M
Only two MA patterns No. A oriented towards the central flow
Means to choose. In this case as well, the result determined by the function shown in FIG.
It is obvious that finer control can be performed by determining the change amount of the pattern No. In this apparatus, the results obtained by the model experiment on the distribution of the charged material are registered as the MA pattern from the peripheral flow toward the central flow, as shown in FIG. This pattern can also be used to control the gas flow corresponding to the position of MA.

(4) MA Action Quantity Diagnosis When the MA pattern No. in FIG. 10 is changed, the gas flow in that portion gradually changes as the charge drops. Then, it usually takes about 12 hours until the influence of the change of the MA pattern No is spread. Therefore, it is necessary to consider the operation history of the MA in order to determine the gas flow corresponding to the MA position in the actual operation. Further, during tapping work, wind is blown for several hours, so that the wind power is temporarily changed and the gas flow is disturbed. It is necessary to remove the factors associated with these transient factors. In this device, these elements are added as follows.

(4-1) MA Operation History FIG. 11 shows an example of MA action correction in consideration of the MA operation history. The horizontal axis represents time, and the vertical axis represents the change amount of the MA pattern No. For example, inference of MA pattern change amount (3-4)
In the above item, the instruction of +2 as the MA pattern change amount continues for 10 hours ((a) in FIG. 11), and at time 0, the MA pattern N
It is assumed that o is changed by +2 ((c) in FIG. 11). Then, the effect gradually appears in the gas flow as the charge drops ((b) in FIG. 11). In actual operation, this point is taken into consideration, and assuming a time (about 6 hours after) when the effect of changing the MA pattern No. by +2 appears for only +1 (6 hours later), the MA pattern No. is changed by +1 again. In addition, here too, if the change amount of the MA pattern No.
If you use the value obtained in 1 (b), you can control it a little more finely, but this device was used to approach the operation of the operator.

(4-2) Transient factors such as blast pressure Since the air is blown for several minutes during tapping work, the blast pressure and other factors temporarily change. For this reason, the temporary action associated with the wind reduction is removed by taking the actual action that started when the instruction to change the MA pattern No. continued twice or more in the same direction. Moreover, when the amount of residual pig iron is large, the gas flow is disturbed. Therefore, the remaining amount is expressed by a membership function as shown in FIG. 12, and the action amount is multiplied by the value to correct.

(4-3) Execution of MA action The result of the above (4-2) is notified to the operator by the display device (CRT) and the alarm device, and when the control mode is automatic, the signal is MA. It is transmitted to a control device (PLC) to automatically control individual MA strokes, which is useful for circumferential charge distribution control. Further, in the manual mode, the operator changes the stroke setting of the MA control device by looking at the display, which is useful for controlling the distribution of the charged material in the circumferential direction.

(5) Operation record FIG. 13 shows the transition of the operation index after the control by this apparatus is started. It can be seen that the realization of the control by this device made the gas flow distribution in the circumferential direction appropriate, and the effect on the operation side was gradually expanded.

[0047]

Industrial Applicability As described above, the present invention is a systemization of advanced operational knowledge about the control of the distribution of the charged material in the circumferential direction for the purpose of standardizing and handing down the operation technology, and the automation of the operation. The effect of is obtained. (1) High-level standardization and transmission of operation technology (2) Reduction of operator work load, automation of operation (3) Optimization of gas flow judgment by advanced processing of sensor information (high accuracy) (4) Real-time monitoring and control Realization of (5) (as a result of (1) to (4) above) Realization of control narrower than conventional operator control (6) (as a result of (1) to (4) above) Operation effect shown in FIG. Confirmation of

[Brief description of drawings]

FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a method of determining an exponential smoothing constant,
(A) is waiting time for loading, (b) is wind reduction time, (c) is MA
The number of actions.

FIG. 3 is a diagram showing an example of determination of gas flow intensity.

FIG. 4 is a diagram showing measurement data of a furnace opening television and processing examples.

FIG. 5 is a diagram showing an installation situation of a fixed sonde and an example of measurement data.

FIG. 6 is a diagram showing an example of determination of transition tendency of gas flow.

FIG. 7 is a diagram showing an example of converting sensor data into data corresponding to a position of MA.

FIG. 8 is a diagram showing an example of standardization of a synthesis result.

FIG. 9 is a diagram showing an inference example of a change amount of an MA pattern No.

FIG. 10 is a diagram showing a MA pattern No registration status.

FIG. 11 is a diagram showing a correction example in which an operation history of MA is added.

FIG. 12 is a diagram showing an example of a correction function for the amount of residual pig iron.

FIG. 13 is a diagram showing an operation result.

FIG. 14 is a diagram showing the distribution control of the charging material and the condition of the furnace opening.

FIG. 15 is a diagram showing an installation situation of MAs.

[Explanation of Codes] 10 Blast Furnace 20 Process Computer 30 Knowledge Processing Computer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsushi Takekoshi 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nippon Steel Pipe Co., Ltd. (72) Inventor Masaaki Sakurai 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Nippon Steel Pipe Incorporated (72) Inventor Shinichi Matsubara 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nippon Steel Tube Co., Ltd.

Claims (3)

(57) [Claims] 1. A knowledge base in which various kinds of knowledge about blast furnace operation obtained from operational experience and model experiments are registered, a means for acquiring data from various sensors installed in the blast furnace at a predetermined cycle, and Corresponding to the position of a plurality of movable armors (hereinafter referred to as MA) arranged along the circumferential direction for each sensor based on the knowledge base and the noise-removed data. Reasoning means for respectively inferring the strength and the transition tendency of the generated gas flow, an operation file in which the operation information in the blast furnace operation, and pig iron information are taken in and saved at any time, and the inference result is saved in the operation file. Based on the information obtained and the knowledge base, a synthesis means for synthesizing the intensity and transition tendency of the gas flow corresponding to the position of MA, and the intensity and estimation of the gas flow. The transfer tendency is divided into a plurality of stages, respectively, and a matrix is formed by the strength of the gas flow and the transition tendency, and the change operation amount of the MA corresponding to the strength of the gas flow and the transition tendency is stored as a component of the matrix. Storage means for storing the MA action determination matrix, means for applying the synthesis result by the synthesis means to the MA action determination matrix, and determining the change operation amount of each MA; Blast furnace charge distribution control device having means for determining the drive amount and transmitting the drive amount to the drive control device of the MA to control the MA. 2. The operation file stores MA operation history and operation information associated with the operation history, and
The blast furnace charge distribution control device according to claim 1, further comprising a correction unit that corrects the drive amount of the MA based on the operation information. 3. The blast furnace charge distribution control device according to claim 2, further comprising teaching means for outputting the corrected drive amount of the MA by video or audio.