JP5369498B2 - Coke oven drymen pressure control method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device for controlling coke oven collecting pipe pressure by which collecting pipe pressure is not made instable while meeting gas flow variation during coal charge. <P>SOLUTION: In the method for controlling coke oven collecting pipe pressure, a collecting pipe gas generation flow rate is estimated from a collecting pipe pressure measurement value based on a model, a valve opening degree ideal orbital is obtained based on the estimated gas flow rate and a pressure control valve is operated based on the obtained valve opening degree ideal orbital. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a coke oven dry mene pressure control method and apparatus for controlling the dry mene pressure of a coke oven.

In the conventional coke oven drain pressure control method, a technique for suppressing a large increase in pressure in the dry menn at the time of charging coal is disclosed. For example, in Patent Document 1, before entering the coal charging operation, in order to prevent the pressure in the dry men from rapidly increasing greatly, the pressure in the dry men is detected, and this is used as the target pressure value. In order to eliminate the difference, feedback control is performed to correct the opening of the pressure regulating valve between the dry men and the suction main. When the coal charging operation is started, it is sent to the PIC controller and set in advance. The feedforward control is performed so that the opening amount is added and output to the control damper (pointing to the pressure control valve) of the PIC (the first column of the specification of Patent Document 1, the lines of claims 13 to 27) (See reference). The operation is performed by setting in advance the opening of the pressure control valve and the duration of the feedforward control during feedforward control (hereinafter also abbreviated as FF control).
JP-A-6-93267

  However, in the above-described prior art, the opening degree of the pressure control valve and the duration of the feedforward control during the feedforward control (hereinafter also abbreviated as FF control) are set in advance. There is a problem that the drain pressure becomes unstable because it cannot cope with changes in gas flow rate during coal loading due to operational changes such as changes in the amount of coal and deterioration of equipment.

  An object of the present invention is to provide a coke oven dry mene pressure control method and apparatus in which the dry mene pressure does not become unstable in response to changes in the gas flow rate during coal loading.

The above problem is solved by the following means.
[1] A coke oven drymen pressure control method for controlling the drymen pressure of a coke oven,
Doraimen estimates the pressure and dry-Men gassing rate based from the measured value of the secondary-side pressure in the model shown in the following equation (1) of the pressure regulating valve, for the estimated gas generation rate, the Doraimen pressure fluctuations 0 The valve opening ideal trajectory , which is the time change of the valve opening , is obtained, the pressure adjustment valve is operated so that the valve opening of the obtained valve opening ideal trajectory is obtained , and the drymen pressure set value and the actual pressure value are the compensation deviations, coke oven Doraimen pressure control how, which comprises carrying out the PID control of the PI controller.

[2] A coke oven drymen pressure control device for controlling the drymen pressure of the coke oven,
A dry mene gas generation flow rate estimating means for estimating a dry mene gas generation flow rate from the measured values of the dry men pressure and the secondary pressure of the pressure regulating valve based on the model shown in the following formula (1)
For the estimated gas generating rate, the Doraimen pressure variation as a time change of the valve opening to 0, and the valve opening degree ideal trajectory calculating means for determining a valve opening ideal trajectory,
Operates by outputting the calculated valve opening of the ideal trajectory and operating the pressure control valve by PID control of the PI controller to compensate for the deviation between the drymen pressure set value and the actual pressure value. coke oven Doraimen pressure control equipment, characterized in that a regulating valve operation means.

  The present invention estimates a dry mens gas generation flow rate from a dry mend pressure measurement value based on a model, obtains a valve opening ideal trajectory based on the estimated gas generation flow rate, and operates a pressure control valve based on the obtained valve opening ideal trajectory As a result, the pressure can be controlled stably even during coal loading with large pressure fluctuations, and the coke oven operation can be stabilized.

  Since the timing of coal loading is known in advance, it is sufficient to measure the generated gas flow rate at this timing and perform FF control so as to cancel the influence of disturbance due to the measured generated gas flow rate. It is difficult to measure the gas flow rate of each furnace group because of the difficulty of the above and failure due to tar adhesion in the gas.

  Therefore, the present inventors estimate the gas generation flow rate from the model formula, obtain the valve opening ideal trajectory for making the pressure fluctuation zero based on the estimated gas generation flow rate, and based on the valve opening ideal trajectory The present invention has been reached in which the pressure control valve is operated and the pressure deviation is compensated by PID control.

  The best mode for carrying out the present invention will be described below with reference to the drawings and mathematical expressions. FIG. 7 is a diagram illustrating a dry men pressure control system according to the present invention. In the figure, 1 is a coke oven, 2 is a dry men (collecting pipe), 3 is a diffusion pipe, 4 is a pressure guiding pipe, 5 is a pressure transmitter, 6 is a pressure control valve, 7 is a hydraulic device, 8 is a transport pipe, 9 is PI controller, 10 is a control device, 11 is a pressure transmitter (secondary side), and 12 is a valve opening ideal trajectory calculation unit.

C gas generated from a plurality of carbonization chambers (not shown) in the coke oven 1 gathers in a dry men (collection pipe) 2 and passes through a pressure transmitter 5 and a transport pipe 8 to a gas purification facility (not shown). Sent. The C gas pressure in the dry men 2 is guided by the pressure guiding tube 4 and measured by the pressure transmitter 5 and the pressure on the secondary side is measured by the pressure transmitter (secondary side) 11 installed in the transport pipe 8 on the secondary side. taking measurement. Then, the measured current pressure value is transmitted to the control device 10, and based on the measured pressure value, a control signal is calculated by the PI controller 9 and the valve opening ideal trajectory calculation unit 12, and the control signal is hydraulically transmitted. Drymen pressure is controlled by adjusting the opening and closing of the feed pressure control valve to the device 7 (for example, hydraulic cylinder).

FIG. 2 is a diagram for explaining modeling for obtaining the gas generation flow rate in the present invention. FIG. 2 (a) is a diagram schematically showing the process, and FIG. 2 (b) is a block diagram showing a model equation according to the following equation (1) in the form of a transfer function.

  In addition, what is necessary is just to obtain | require parameters, such as (alpha) and Cv in Formula (1), by acquisition etc. from an identification and valve manufacture characteristic. In addition, an example of how to obtain will be described in an embodiment described later.

In the present invention, the gas generation flow rate is estimated from the pressure fluctuation using the model equation of the process described above, and the valve opening ideal trajectory is obtained based on this generation amount, and the valve is operated.
FIG. 1 is a block diagram of a coke oven drymen pressure control apparatus according to the present invention. A portion surrounded by a broken line in the figure is a characteristic portion of the present invention in which the gas generation flow rate is estimated from the measured pressure, and the valve opening ideal trajectory is obtained based on this generation amount. Drymen pressure and secondary pressure are measured, and an estimated gas flow rate is calculated based on the model formula. Then, the estimated gas flow rate is input to the feedforward control model, a valve opening ideal trajectory that cancels the influence of disturbance is obtained, and the valve opening is output and operated. The valve opening ideal trajectory in the present invention refers to a change over time in the valve opening at which drymen pressure fluctuation is zero with respect to the estimated gas generation flow rate. It should be noted that the calculation of this part may be performed by either the control device 10 in FIG. 7 described above or an external calculation device provided separately. In addition to this, the compensation for the pressure deviation due to the sudden rise in the generated gas flow rate, that is, the compensation for the deviation between the drymen pressure set value and the actual pressure value (measured value of the pressure transmitter 5) The controller performs PID control.

  Also, the disturbance transfer function Gd (s), controlled object transfer function Gp (s), and FF control transfer function Gf (s) in the figure are expressed by the following equation (2).

Embodiments to which the present invention is applied will be described below. First, the parameter determination method for α in the equation (1) will be described. The pressure (P ₀ (actual furnace)) at the step response (valve opening 46% → 45%) was measured in a state where the gas generation amount after 10 minutes of coal charging was stable, and P shown in the following equation (3) Α was determined by searching for α that minimizes the evaluation value H, which represents the sum of squared deviations of ₀ (actual furnace) and P ₀ (model) for a predetermined time.

The generated gas flow rate F ₀ was obtained by multiplying the gas generation flow rate of the entire coke oven by the ratio of the coal amount of the target furnace group to the total furnace coal amount (6.43 Nm ³ / s). Further, the measured value (−144 mmH ₂ O) was used as the secondary pressure P ₁ . The value of α determined is 0.00002, and FIG. 3 is a diagram showing a comparison in step response between the actual furnace and the determined model.

  Next, FIG. 4 is a figure which shows an example of the result of having estimated the gas flow rate at the time of coal loading from the pressure fluctuation at the time of coal loading. FIG. 4 (a) is a diagram showing pressure fluctuation (measured value) during coal loading, and FIG. 4 (b) is a diagram showing a result of estimating the gas flow rate during coal loading from the actually measured pressure fluctuation. .

  Phenomenologically, the pressure suddenly increases due to an increase in the flow rate of the generated gas during coal loading, but it is difficult to measure the flow rate of the generated gas to be measured for the reasons described above. The gas flow fluctuation at the time of coal loading is estimated from the measured pressure fluctuation.

Furthermore, FIG. 5 is a figure which shows an example of the result of having verified the conventional pressure controllability at the time of coal loading. This is a result of simulating the current coal pressure controllability when the gas generation amount changes in the pattern of FIG. 4 (b), and the pressure fluctuation range shows the same result as SV ± 6.2mmH ₂ O. .

And FIG. 6 is a figure which shows an example of the comparison result of this invention and the conventional pressure control. Conventionally, the pressure fluctuation range was SV ± 6.2 mmH ₂ O, but it can be seen that the pressure fluctuation range is SV ± 0.5 mmH ₂ O and the pressure fluctuation can be greatly reduced by applying the present invention.

It is a figure which shows the block diagram of the coke oven dry men pressure control apparatus which concerns on this invention. It is a figure explaining modeling in the present invention. It is a figure which shows the comparison in the step response of a real furnace and the determined model. It is a figure which shows an example of the result of having estimated the gas flow rate at the time of coal loading from the pressure fluctuation at the time of coal loading. It is a figure which shows an example of the result of having verified the pressure controllability at the time of the conventional coal loading. It is a figure which shows an example of the comparison result of this invention and the conventional pressure control. It is a figure explaining the dry men pressure control system of the present invention.

Explanation of symbols

1 Coke oven 2 Dry men (collecting pipe)
DESCRIPTION OF SYMBOLS 3 Dissipation pipe 4 Pressure guiding pipe 5 Pressure transmitter 6 Pressure control valve 7 Hydraulic device 8 Transport pipe 9 PI controller 10 Control apparatus 11 Pressure transmitter (secondary side)
12 Valve opening ideal trajectory calculation section

Claims (2)

A coke oven drymen pressure control method for controlling the drymen pressure of a coke oven,
Doraimen estimates the pressure and dry-Men gassing rate based from the measured value of the secondary-side pressure in the model shown in the following equation (1) of the pressure regulating valve, for the estimated gas generation rate, the Doraimen pressure fluctuations 0 The valve opening ideal trajectory , which is the time change of the valve opening , is obtained, the pressure adjustment valve is operated so that the valve opening of the obtained valve opening ideal trajectory is obtained , and the drymen pressure set value and the actual pressure value are The coke oven drymen pressure control method is characterized in that compensation for the deviation is performed by PID control of a PI controller .

A coke oven drymen pressure control device for controlling the drymen pressure of a coke oven,
A dry mene gas generation flow rate estimating means for estimating a dry mene gas generation flow rate based on a model represented by the following equation (1) from measured values of the dry mens pressure and the secondary pressure of the pressure regulating valve ;
For the estimated gas generating rate, the Doraimen pressure variation as a time change of the valve opening to 0, and the valve opening degree ideal trajectory calculating means for determining a valve opening ideal trajectory,
Operates by outputting the calculated valve opening of the ideal trajectory and operating the pressure control valve by PID control of the PI controller to compensate for the deviation between the drymen pressure set value and the actual pressure value. A coke oven drymen pressure control device comprising a control valve operating means.

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