JPH079006B2 - Blast furnace bellless charging equipment control method - Google Patents

Description

The present invention relates to a method for controlling a blast furnace bellless charging facility.

[Prior Art] Raw material flow rate control valve (hereinafter FCG) of conventional blast furnace bellless charging equipment
The opening degree is controlled by the following method.

For example, in the control method disclosed in Japanese Patent Laid-Open No. 60-46306, the weight in the lower bunker is measured with a load cell or the like while the raw material is being discharged, and the opening of the FCG is controlled so as to match the target weight pattern. ing.

Further, the control method disclosed in Japanese Patent Laid-Open No. 61-238906 calculates the correction amount of the opening based on the difference between the discharge time of a plurality of charges in the past and the set value, and determines the required opening for the next time. It is corrected to control the opening of the FCG.

In addition, we have multiple discharge time data such as reserving hopper and discharge time data in the lower bunker, and linearly regress these relationships for each FCG opening to show the relationship between the FCG opening and the above hopper. There is also a control method for obtaining and determining the opening of the FCG from the discharge time of the hopper based on this relationship (hereinafter referred to as feedforward control).

[Problems to be Solved by the Invention] In the control method disclosed in Japanese Patent Laid-Open No. 60-46306, the furnace body for high-pressure operation and the lower bunker are integrated, and Since the change in the furnace pressure becomes a disturbance, it is difficult to measure the weight of the lower bunker with high accuracy, and there is a problem that sufficient control accuracy cannot be obtained.

Further, in the control method disclosed in Japanese Patent Laid-Open No. 61-238906, the obtained correction data is used for the next control data, so it is not possible to follow the change in the flow rate characteristics of the FCG due to the change in the properties of the raw material. It was difficult. Further, in feed-forward control, it is possible to follow changes in the properties of the raw material, but the control accuracy is determined by the discharge time of the razor hopper and the accuracy of the FCG relational expression, and sufficient accuracy has not been obtained.

The present invention has been made in order to solve such a problem, and it is possible to control the opening of the FCG with high accuracy and make it possible to make the raw material charging start point and the end point coincide with each other. The purpose is to obtain a method of controlling equipment.

[Means for Solving the Problem] A method of controlling a blast furnace bellless charging facility according to the present invention includes a step of generating a reference opening function from a relationship between a charging speed and an opening of an FCG based on a track record, and The method includes a step of obtaining a target charging speed from the weight of the raw material to be charged and the number of turns by the turning shooter, and a step of finding a reference opening of the FCG from a reference opening function and the target charging speed.

Further, the step of obtaining a feedback correction amount based on the previous charging speed, the previous target charging speed and the reference opening function, and the previous feedback correction amount, and the discharge weight and discharge time of the raw material from the hopper based on the actual results. From the hopper, and a step of determining the feedforward correction amount based on the discharge weight of the raw material charged this time from the hopper, the discharge time, and the approximate expression.

Further, there is a step of obtaining an FCG opening command value based on the FCG reference opening, the feedback correction amount, and the feedforward correction amount, and adjusting the FCG opening based on the opening command value.

[Operation] In the present invention, in addition to obtaining the reference opening of the FCG, the feedback correction amount is obtained based on the past performance, and the feedforward correction amount based on the property of the raw material charged this time is obtained as the reference amount. Correct the opening to obtain the FCG opening command value. Then, the FCG opening is adjusted based on the FCG opening command value. By adjusting the opening of the FCG, the charging rate of the raw material is properly controlled.

[Embodiment] FIG. 1 is an explanatory view of a control device and its associated equipment for carrying out a method according to an embodiment of the present invention. In the figure, (1
0) is the lower bunker, and (11) is the FCG provided under the lower bunker (10). (12) is the top of the blast furnace, and (1
3) is a turning shooter installed in the furnace. (14) is a weighing hopper, and the raw material discharged from the weighing hopper (14) is conveyed by a belt conveyor (not shown) to the lower bunker (10) and is fed into the furnace via the FCG (11). It is loaded into the furnace by the turning operation of the turning shooter (13).

(20) is an FCG opening meter that detects the opening of the FCG (11).
(21) is a raw material passage sensor for detecting the start and end of raw material charging. (22) is a load cell, weighing hopper (14)
Detects the weight of raw material discharged from.

The charging time measuring circuit (30) measures the charging time of the raw material based on the output of the raw material passage sensor (21). A charging speed calculation circuit (31) calculates the charging speed of the raw material based on the charging weight from the load cell (22) and the charging time from the charging time measuring circuit (30).

(50) is a data file that stores charging speed information from the charging speed measurement circuit (31) and opening information from the FCG opening gauge (20), and records the charging speed and FCG opening. Data is always filed. The content of the data file at this time is, for example, for each raw material brand, as shown in Fig. 2, file the charging speed data for every 0.1 ° per opening section (10 °) of the FCG (11). is there.

(51) is an arithmetic unit, which calculates the average value of the charging speed for each opening based on the data in the data file (50),
Next, as shown in FIG. 3 (A), a scatter diagram of the opening degree with respect to the charging speed is created, and the scatter diagram is approximated to a curve (eg, cubic function) as shown in FIG. 3 (B). Generate an opening function. For example, the function shown in the following equation is generated.

^{θ = av 3 + bv 2 +} cv + d (1) (32) is a target velocity arithmetic circuit, based on the number of turns of the swivel chute set in advance and charged by weight, vo = charged weight ÷ (planned number of turns × 1 Target charging speed vo
Ask for. Reference numeral (33) is a reference opening calculation circuit, which calculates the reference opening θo of the FCG by the following equation based on the target charging speed vo and the reference opening function from the calculation device (51).

θo = avo ³ + bvo ² + cvo + d (2) (35) is a change-over switch, and it can be automatically controlled by using the reference opening θo from the reference opening calculation circuit (33) as a control signal or by a predetermined switch. Select whether to control with the set opening of FCG. In this embodiment, the case where automatic control is selected will be described below. (35) and (36) are buffers, respectively, in which the previous actual charging speed is stored in the buffer (35), and the previous target charging speed is stored in the buffer (36).

Reference numeral (37) is a feedback correction amount calculation circuit (hereinafter referred to as FB correction amount calculation circuit), and the feedback correction amount (hereinafter referred to as FB correction amount) Δθ1 is obtained by the following calculation.

FIG. 4 is an explanatory diagram for obtaining the FB correction amount Δθ1,
First, the error Δv at the time of loading the same brand last time is obtained by the following equation by reading the data from the buffers (35) and (36).

Δv = previous actual charging speed−previous target charging speed (3) Then, the error is corrected by the following equation from this Δv and the reference opening θo (= f (vo)) for the current target charging speed vo. The reference opening θo ′ of is calculated.

θo ′ = f (vo−Δv) (4) The reference opening correction amount (theoretical value) Δθo1 is calculated by the following formula.

Δθo1 = θo′−θo (5) Next, this Δθo1, the correction gain G1 (0 to 1) and the previous
The FB correction amount Δθ1 is obtained from the FB correction amount.

Δθ1 = G1 × Δθo1 + previous FB correction amount (6) The discharge time measuring circuit (38) measures the discharge time of the raw material based on the output of the load cell (22).

(52) is a data file, and the discharge time measurement circuit (3
The discharge time information from 8) and the discharge weight information from the load cell (22) are stored, and data on the relationship between the two is accumulated. The contents of the data at this time are, for example, as shown in FIG. 5, and the latest data regarding the relationship between the discharge weight of the unwind weigher and the discharge time for each material brand is stored for each material brand, for example, 3,000 pieces.

Reference numeral (53) is an arithmetic circuit. Based on the data in the data file (52), a scatter diagram of the discharge time with respect to the weight is created as shown in FIG. 6 (A), and as shown in FIG. 6 (B). The scatter diagram is linearly approximated as shown in the following equation.

ω = αt + β (7) (39) is a feedforward correction amount calculation circuit (hereinafter referred to as FF correction amount calculation circuit), which determines the discharge speed α ′ of this time based on the charging weight ω ′ of this time and the discharge time t ′. Calculate by the following formula.

α ′ = (ω′−β) / t ′ (8) Next, from the ratio α ′ / α of the discharge speed α ′ to the standard discharge speed α, the reference opening θo (= The predicted speed v ′ when charging at f (vo)) is calculated, and the predicted speed error Δv is calculated.

v ′ = vo × α ′ / α (9) Δv = v′−vo (10) Next, the same calculation as the FB correction amount calculation is performed from this Δv to obtain the correction amount (theoretical value) Δθ02, and this Δθ02 And the correction gain G2 (0 to 1), the feedforward correction amount (hereinafter referred to as FF correction amount) Δθ2 is obtained.

Δθ2 = G2 × Δθ02 (11) (40) is a calculation / control circuit, which is the reference opening θo selected by the selection switch (34) and the FB correction amount Δθ1 and FF correction from the FB correction amount calculation circuit (37). The FF correction amount Δθ2 from the amount calculation circuit (39) is added, and the added signal (= θ0
+ Θ1 + θ2) is output to the drive unit (not shown) as the FCG opening command value.

In the embodiment configured as described above, the data file (50) stores the actual data showing the relationship between the charging speed and the opening degree of the FCG, and the arithmetic unit (51) is based on the data. Then, the reference opening function is calculated by the equation (1), and the reference opening generation circuit (33) determines the reference opening function and the target charging speed.
Based on vo, the FCG reference opening θo is calculated by the equation (2).

The FB correction amount calculation circuit (37) calculates the difference between the previous charging speed from the buffers (37) and (38) and the previous target speed (3).
FB correction amount Δθ obtained from equations (4) to (6)
Ask for 1.

On the other hand, the data file (52) stores the actual data showing the relationship between the discharge weight of the weighing hopper (14) and the discharge time, and the arithmetic circuit (53) calculates the discharge time by the formula (7) based on the data. An approximate expression showing the relationship between the weight and the discharged weight is obtained. Then, the FF correction amount calculation circuit (39) is (4),
The FF correction amount Δθ2 is obtained from the equations (5) and (8) to (10).

The FCG reference opening θo, the FB correction amount Δθ1 and the FF correction amount Δθ2 obtained as described above are added by the calculation / control circuit (40), and the added value is used as the FCG opening command value FCG (1
It is supplied to the drive circuit (not shown) in 1) to adjust the opening of the FCG (11).

As described above, the FB correction amount θ1 based on the previous results
Therefore, the feedback control is performed based on the obtained value, and the correction based on the past results is performed. Further, the FF correction amount θ2 is calculated based on the property of the raw material charged this time, and the feedforward correction is performed based on the FF correction amount θ2. The charging rate of the raw material can be appropriately controlled, the starting point and the ending point of the raw material can be matched, and the raw material can be uniformly charged.

The outputs of the arithmetic circuits (51) and (53) do not have to be output every time, but may be output when new data is accumulated in the data files (50) and (52) to some extent. The switches (S1) and (S2) may be closed at appropriate timing. Further, when the correction based on the FB correction amount and the FF correction amount is not performed, the switches (S3) and (S4) are opened.

In the above embodiment, the data files (50) and (52) and the arithmetic circuits (51) and (53) shown in FIG. 1 are included in the process computer, and the rest are included in the charging control device. In this case, each arithmetic circuit or the like can be realized by a hardware configuration itself, but it goes without saying that it can also be realized by software of a computer.

[Effects of the Invention] As described above, according to the present invention, based on past achievements,
Since the FB correction amount is calculated and the FF correction amount based on the property of the raw material to be charged this time is calculated to correct the reference opening, it is possible to control according to the property of the raw material.
Highly accurate control is possible.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view showing an apparatus for carrying out a method according to an embodiment of the present invention and its related equipment, and FIG. 2 shows an FCG opening and a charging speed in a certain material brand. FIG. 3 (A) and FIG. 3 (B) are characteristic diagrams showing the relationship between the average charging speed and the FCG opening, and FIG. 4 is an explanation for obtaining the FB correction value. FIG. 5 is an explanatory diagram of a data file showing the relationship between the discharged weight and the discharged time, FIGS. 6 (A) and 6 (B) are characteristic diagrams showing the relationship between the discharged time and the discharged weight, and FIG. FIG. 4 is an explanatory diagram for obtaining the relationship between the discharge weight of the raw material and the discharge time of this time. In the figure, (10) is the lower bunker, (11) is the FCG, and (1
3) is a turning shooter, and (14) is a hopper.

Claims (1)

[Claims] 1. A step of generating a reference opening function based on a relationship between a charging speed based on actual results and an opening of a raw material flow rate control valve, and a target based on a weight of a raw material charged this time and a set number of revolutions of a rotating shooter. The step of obtaining the charging speed, the step of obtaining the reference opening of the raw material flow rate control valve from the reference opening function and the target charging speed, the previous charging speed, the previous target charging speed and the reference opening function, The step of obtaining the feedback correction amount based on the previous feedback correction amount, the step of obtaining an approximate expression showing the relationship between the discharge weight and discharge time of the raw material from the hopper based on the actual results, and the raw material to be charged this time The step of obtaining the feedforward correction amount based on the discharge weight from the hopper, the discharge time, and the above approximate expression, and the reference opening of the raw material flow rate control valve, the feedback correction amount and the feedforward correction amount. Based on the opening command value of the raw material flow rate control valve, and adjusting the opening degree of the raw material flow rate control valve based on the opening command value of the raw material flow rate control valve. Equipment control method.