KR20010054883A - Method and apparatus for controlling a crusher of a pulverized coal injection - Google Patents

Abstract

PURPOSE: An apparatus and a method for controlling a crusher of a pulverized coal facility are provided which prevent increase of pulverized lignite and manufacture high quality pulverized coal by appropriately controlling blown air flow rate depending on the supplied coal amount of the crusher during operation of the crusher and controlling a temperature of the outlet of the crusher with a mixing ratio of hot and cold air. CONSTITUTION: The apparatus comprises a blown air flow rate control part outputting control signals to a cold air flow rate control valve (2) and a hot air flow rate control valve (1); a supplied coal amount adjusting part outputting signals to a cold feeder (6) for controlling rotational speed by correcting a temperature of the outlet of a crusher; and a crusher outlet temperature control part correcting a crusher outlet temperature to control signals outputted from the supplied coal amount adjusting part and the blown air flow rate control part. The method comprises a first step of detecting a blown air flow rate at a blown air flow rate measuring unit, a supplied coal amount at a speed detector and an outlet temperature of a crusher at the outlet temperature gauge; a second step of obtaining a blown air flow rate converted value for the supplied coal amount using the detected values in the first step, and setting a crusher outlet temperature; a third step of outputting by comparing the blown air flow rate values detected in the first step with the set values, and outputting the difference by comparing the crusher outlet temperature detected in the first step with the set values; and a fourth step of controlling the amount of cold air gas and hot air gas entered into the crusher by outputting control signals after obtaining a hot air flow rate set value, and control signals after obtaining a cold air flow rate set value.

Description

Method and apparatus for controlling a crusher of a pulverized coal injection

The present invention relates to a pulverizer control device and method of the pulverized coal plant, and in particular, to control the appropriate blow flow rate control and the outlet temperature control of the pulverizer in accordance with the amount of coal supply of the pulverizer when operating the pulverizer to prevent the coal coal The present invention relates to a pulverizer control apparatus and a method for pulverized coal plant.

1 is a view showing a pulverizer control state of a conventional pulverized coal plant, the raw coal stored in the call hopper 5 is supplied to the crusher 7 through the call feeder 6, and the hot air supplied by the blowing fan 3. The pulverized coal together with the furnace flue gas is crushed into pulverized coal and stored in the storage hopper 9 through the bag filters 8-1 and 8-2. Pulverized coal stored in the storage hopper is blown into the blast furnace through a plurality of feed tanks (10-1, 10-2, 10-3) in accordance with the blowing process of the pulverized coal blowing facility. The feed amount control unit 22 controls the speed of the feeder 6 to maintain the feed amount constant.

The airflow flow rate control unit 21 compares the airflow flow rate detected by the airflow flow rate measuring apparatus 4 with a set value, and corrects the difference. To this end, the opening ratio of the hot air flow rate control valve 1 is controlled.

The mill outlet temperature control unit 23 controls the opening rate of the cold air flow control valve 2 by comparing the output value sent from the mill outlet temperature detection unit 11 with the set value.

On the other hand, the control of the amount of coal supplied to the grinder is to control only a certain amount of the coal supplied to the grinder, there is a problem that the grinding operation is not properly performed when the air flow rate change or the grinder outlet temperature changes.

The grinder outlet temperature control is controlled by cold air (air air), so that the outlet temperature of the grinder is abnormally controlled when the temperature of the hot air changes as in the blower flow rate control.

The blowing flow rate control is controlled only by the hot air flow rate, and thus greatly affects the outlet temperature 11 of the grinder according to the temperature change (200 ° C. to 300 ° C.) of the hot air. Even though there is no change in the amount of coal supply, it is controlled constantly. Due to this, there is a problem that the coal dust is accumulated in the grinder or the particle size of the pulverized coal stored in the storage hopper exceeds the prescribed value (200 mesh).

In addition, since the hot air and cold air are separately controlled by the blowing flow rate and the pulverizer outlet temperature, it is difficult to realize smooth control according to mutual interference.

The present invention is to solve the above problems, it is possible to control the optimum blowing flow rate and the exit temperature control of the grinder according to the amount of coal supplied to the grinder, to prevent the increase in non-lignite due to inefficient grinder control, It is an object of the present invention to provide a control method of a mill of a pulverized coal plant, which can realize a fine pulverized coal operation of a blast furnace by solving problems such as a particle size non-uniformity of pulverized coal.

The above-mentioned object is to provide a blowing fan for transporting pulverized coal pulverized in a pulverizer, a cold wind flow rate control valve for adjusting the amount of cold wind gas introduced into the blower fan, and a hot air flow rate control for controlling the amount of hot wind gas introduced into the blower fan. A valve, a call hopper for supplying a call to the grinder using a call feeder, an outlet thermometer for sensing the grinder exit temperature, a storage hopper into which the fine powder ground in the grinder is charged, and the storage hopper In a pulverized pulverized coal plant comprising a coal supply amount setting unit for setting the coal supply amount, the control unit for controlling the hot air flow control valve and the cold air flow control valve by converting the coal supply amount set by the coal supply amount set to the blowing flow rate; And after the temperature value detected from the grinder outlet thermometer is corrected to the control signal, the cold air flow control valve and The pulverizer outlet temperature value is set when the blowing flow rate control unit outputs a control signal to the hot air flow rate control valve and a signal for controlling the rotational speed of the call feeder according to the amount of coal supply set by the coal supply amount setter. When the deviation is out of the feeder amount adjusting unit for outputting a signal for controlling the rotational speed to the call feeder by correcting the grinder outlet temperature value, and after detecting the outlet temperature from the milling outlet thermometer, the feeder amount adjusting unit and the air blowing And a grinder outlet temperature control unit configured to correct the outlet temperature value in the control signal outputted from the flow rate control unit.

In addition, in the first step and the first step of detecting the blower flow rate value entering the grinder by the blower flow rate measuring device, detecting the feeder amount value fed into the grinder by the speed detector, and detecting the outlet temperature value of the grinder by the outlet thermometer. Calculates the blow flow rate conversion value for the coal supply amount by using each detected value, compares the blowing flow value and the set value detected in the first step with the second step of setting the mill outlet temperature, and outputs the first step. A third step of outputting the difference by comparing the grinder outlet temperature and the set value detected in the step; and outputting a hot air flow control signal by compensating the grinder outlet temperature to the output signal output in the third step, and in the third step By compensating the exit temperature of the grinder to the output signal, it outputs the cold wind flow control signal to adjust the amount of cold and hot wind gas entering the grinder. Is achieved by a mill control method of a pulverized coal plant comprising a fourth step.

1 is a view showing a mill control state of a conventional pulverized coal plant.

Fig. 2 is a flowchart showing a feed amount control procedure in the pulverized coal pulverizer control according to the present invention.

3 is a view showing a fine coal pulverizer control state according to the present invention;

Figure 4 is a flow chart illustrating a blowing flow rate control method in the mill control of the pulverized coal plant according to the present invention.

<Description of Symbols for Major Parts of Drawings>

1: Hot air flow control valve 2: Cold air flow control valve

3: Blower fan 5: Cole Hopper

6: Call feeder 7: Crusher

8-1,8-2: Bag filter 9: storage hopper

10-1, 10-2, 10-3: Feed tank 31: Feeding quantity setting device

32: blower flow rate setter 33: grinder outlet temperature setter

34: Blowing air flow meter 39: Feedwater quantity meter

θ: Crusher outlet temperature allowance T: Crusher outlet temperature

X: Coal quantity set value a: Blowing flow rate conversion constant with respect to coal quantity

b: Minimum feedrate setpoint c: Blowing flow rate value for the minimum feedrate

Y1: Blowing flow rate conversion value for the feed amount

α: Blowing flow control output value β: Crusher outlet temperature control output value

Y2: Hot air flow rate setting value Y3: Cold air flow rate setting value

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

Figure 2 is a flow chart showing a coal feed amount control procedure in the pulverized coal pulverizer control according to the present invention, Figure 3 is a view showing a pulverized coal pulverizer control state according to the present invention, the present invention is a hot air flow rate control valve ( 1) and a cold air flow rate control valve 2 for controlling the cold wind flow rate are provided in the hot air pipe and the cold air pipe, respectively. Moreover, the blowing flow volume measuring device 4 which detects a blowing flow volume is provided in the rear end. The speed feeder 12 of the feeder is installed in the call feeder, and the mill outlet thermometer 11 is installed at the rear end of the mill.

On the other hand, in the pulverized coal plant according to the present invention, when the amount of coal supply increases, the outlet temperature increases, and when the amount of coal supply decreases, the outlet temperature decreases. Therefore, in the present invention, the amount of supply of coal is adjusted by correcting the outlet temperature value in adjusting the amount of supply of coal.

On the other hand, the present invention comprises a blow flow rate control unit, a pulverizer outlet temperature control unit, and a feed rate adjustment unit.

In the present invention, the coal feed amount adjusting unit supplies a coal feed amount setter 31 which commands the supply of raw coal to a grinder, a coal feed amount converter 42 for converting the speed of the call feeder 6 into a coal feed amount, and a feed amount adjusting system 39. It consists of. The feed amount controller 39 controls the rotation speed of the call feeder 6 based on an input value input from the feed amount setter 31.

The pulverizer outlet temperature control part is composed of a pulverizer outlet temperature setter 33, a pulverizer outlet temperature controller 35 for controlling the blowing flow rate, and a pulverizer outlet temperature controller 36 for controlling the coal supply amount. The outlet temperature value set by the mill outlet temperature setter 33 is input to the mill outlet temperature controller 35 for controlling the blow flow rate. On the other hand, the feeder quantity control grinder outlet temperature controller 36 transmits a signal to the feeder quantity controller 39 described above. In addition, a difference value between the temperature value detected by the grinder outlet thermometer 11 and the temperature set by the grinder outlet temperature setter 33 is input to the feed amount controller 39.

The blow flow rate control unit includes a feed rate amount setter 31 for setting a feed rate to be supplied to the grinder 7, a blow rate setter 32 for converting a signal from the feed rate setter into a blow rate, and a blow rate setter ( 32 is a blown flow rate controller 34 which compensates the blown flow rate value inputted to the blown flow rate measuring device 4 to the signal inputted from 32) and outputs a control signal, and blows the control signal outputted from the blown flow rate adjuster 34. It is composed of ratio controllers 37 and 38 for ratio calculation control to compensate the output value outputted from the flow rate control grinder outlet temperature controller 35, hot air flow rate setter 40, and cold wind flow rate setter 41. .

4 is a flowchart illustrating a blowing flow rate control method in the pulverizer control of the pulverized coal plant according to the present invention. First, the method of controlling the coal supply amount is set when the amount of coal supplied to the pulverizer is set in the coal supply amount setter 31. The value is input to the feed amount controller 39, and at the same time the feed amount set value is input to the blowing flow rate setter 32 which converts the feed amount into the blowing flow rate. The blowing flow rate setter 32 converts the feed rate into the blowing flow rate.

On the other hand, the call feeder speed detector 12 is provided in the call feeder 6 for supplying the call to the grinder 7, and the signal detected by the call feeder speed detector 12 is fed into the feed amount by the feed rate converter 42. The conversion is input to the feed amount controller 39, the feed amount controller 39 compares the set value and the feed amount input difference and outputs the difference value as a control signal of the call feeder (6).

In addition, the exit temperature of the pulverizer should be managed at 80 ± 5 ℃, which is necessary to make the optimum coal powder at all times, and the following control may be combined with the above control of the supply of coal in order to separate the blowing gas and the pulverized coal from the bag filter. To make it possible.

That is, it is determined whether the grinder is in operation (ST101), and after that it is judged whether or not the exit temperature of the grinder is within a predetermined range (± θ) (ST102). ), And when the outlet temperature of the grinder is out of a predetermined range (± θ), the amount of coal supply is controlled by compensating the signal output from the grinder outlet temperature controller 36 for controlling the amount of coal feed.

Referring to the process for setting the pulverizer outlet temperature, when the pulverizer outlet temperature is set in the pulverizer outlet temperature setter 33, the set value is the pulverizer outlet temperature controller 36 for the feed amount control for the feed amount control, and the blower flow rate control Blower flow rate control grinder outlet temperature is input to the controller (35).

The feeder amount control grinder outlet temperature controller 36 outputs a control signal to control the grinder outlet temperature at a constant value, and the feeder amount controller 39 mentioned above is also used to control the feed amount constantly. The control signal is output.

At the same time, if the grinder 7 is in operation and the grinder is in operation, if the exit temperature of the grinder is out of the range of ± θ, the feed temperature control grinder outlet temperature controller 36 controls the feed feeder to adjust the feed amount. The exit temperature of the grinder is controlled to be kept constant, and if the exit temperature of the grinder is within the range of ± θ, the feed amount control is controlled by the feed amount controller 39 so that the constant feed amount control is performed.

Through this, pulverized coal is produced in a state where the exit temperature of the grinder 7 is stable, so that fine coal is produced. As described above, when the feed temperature control grinder outlet temperature controller 36 detects that the detection signal sent from the outlet thermometer 11 is equal to or larger than a set value, the signal is input to the feed amount controller 39. Thereafter, the feed amount controller 39 outputs a signal for controlling the rotation speed of the motor, which is a motor for driving the call feeder 6.

On the other hand, in the feed rate controller 39, the outlet temperature value output from the feed rate control grinder outlet temperature controller 36 and the value detected by the speed detector 12 are converted by the feed quantity converter 42 and input. And a control signal for controlling the call feeder 6 on the basis of the feed amount set in the feed amount setter 31. That is, the number of revolutions of the call feeder 6 is controlled by compensating the outlet temperature sent from the feeder amount control grinder outlet temperature controller 36.

By doing so, without controlling the outlet temperature, if the temperature detected by the outlet thermometer is greater than or equal to the set value, the rotational speed of the call feeder 6 is reduced by the deviation from the set value.

On the other hand, the blowing flow rate control is a combination of the above-mentioned supply amount of coal control and the mill outlet temperature control. If it is determined whether the grinder is in operation and the feed amount is set in the feed amount setter 31 in the state where the grinder 7 is in operation, the feed amount is calculated by the following blower flow rate.

Y1 = a (X-b) + c

In the above formula, X is the amount of coal supply, b is the lowest amount of coal supply, c is the minimum flow rate for the lowest amount of coal supply, a is the proportionality constant, and Y1 is the amount of blowing flow according to the amount of supply of coal. It is calculated to have a proper blowing flow rate value.

It is judged whether the grinder is in operation (ST111), and if it is in operation, the amount of coal supplied is converted into the amount of blown air by the blower flow rate setting unit, and the converted signal Y1 is set to a set value in the blower flow controller 34 (ST114), The blowing amount detected by the blowing flow rate measuring device 4 is input, compared, and outputs a control output signal α which is the difference value. (ST115)

The control output signal? Of the blowing flow controller 34 compensates the mill exit temperature so as to control the hot air flow rate and the cold wind flow rate. On the other hand, the pulverizer outlet temperature control system 35 for blowing flow rate control compares the pulverizer outlet temperature setting signal with the temperature detection signal to generate the control output signal β (ST212), and the control output signal β is the above blower. It is calculated in combination with the flow rate control output signal α to set the hot air flow rate and the cold wind flow rate appropriate for the amount of coal supply.

Meanwhile, the grinder outlet temperature is compensated before outputting the hot air flow control signal (ST311), and the grinder outlet temperature is compensated before outputting the cold air flow control signal. (ST312)

As a result, the optimum blowing flow rate is controlled according to the amount of coal supply and the mill exit temperature.

Here, the hot air flow rate setting signal for controlling the appropriate mill grinder exit temperature according to the amount of coal supply is calculated by Equation 2 below.

Y2 = α- (β + 50.0) × K1

In addition, the cold wind flow rate setting signal for controlling the appropriate mill grinder exit temperature depending on the amount of coal supply is converted by the following equation (3).

Y3 = α- (β + 50.0) × K1

As described above, the pulverizer control method of the present invention maintains the pulverizer outlet thermometer 11 and supplies a constant blowing flow rate according to the amount of coal supply at an appropriate ratio of the hot air flow rate and the cold wind flow rate, thereby stabilizing the exit temperature of the pulverizer. The present invention provides a pulverizer control method for pulverizing fine pulverized coal as well as allowing the pulverized pulverized coal to be smoothly called up into a storage hopper.

As described above, the pulverizer control method of the pulverized pulverized coal plant according to the present invention enables the optimum blowing flow rate control and the exit temperature control of the pulverizer according to the amount of coal supplied to the pulverizer, thereby reducing the non-brown coal according to the inefficient pulverizer control. The present invention provides a control method for a pulverizer of a pulverized coal plant, which can prevent and solve a problem such as uniformity of the pulverized coal in a pulverized coal.

Therefore, the present invention has the effect of reducing the cost by improving the injection of high pulverized coal, which is sex energy, and improving the aging of the blast furnace, thereby greatly improving productivity.

Claims (5)

A blowing fan for transporting the pulverized coal pulverized by a pulverizer, a cold wind flow rate control valve for adjusting an amount of cold wind gas introduced into the blowing fan, a hot wind flow rate control valve for adjusting an amount of hot wind gas introduced into the blowing fan, and Set a call hopper for supplying a call using a call feeder to the grinder, an outlet thermometer for detecting the exit temperature of the grinder, a storage hopper into which the fine powder ground in the grinder is charged, and the amount of feed coal supplied to the storage hopper. In the blast furnace pulverized coal installation including a coal supply amount setter to The control unit for controlling the hot air flow rate control valve and the cold air flow rate control valve by converting the feed water amount set in the feed rate amount setter into a blowing flow rate, and the temperature value detected from the grinder outlet thermometer is corrected to the control signal. After that, the air flow rate control unit for outputting a control signal to the cold air flow rate control valve and the hot air flow rate control valve; When outputting a signal for controlling the rotational speed of the call feeder according to the feed amount set from the feed rate setter, if the mill exit temperature value is out of the set range, the mill exit temperature value is corrected to the call feeder A coal supply amount adjusting unit for outputting a signal for controlling the rotation speed; And a pulverizer outlet temperature controller configured to detect a pulverizer outlet temperature value in a control signal output from the feed rate control unit and the blower flow rate controller after detecting the outlet temperature from the pulverizer outlet thermometer. Device. A first step of detecting a blow flow rate value entering the grinder by a blow flow rate measuring device, detecting a feed rate value fed into the grinder by a speed detector, and detecting an exit temperature value of the grinder by an outlet thermometer; A second step of calculating a blow flow rate conversion value for the amount of coal supply by using each detected value detected in the first step, and setting the mill exit temperature; A third step of comparing and outputting the blower flow rate value detected in the first step and the set value, and comparing the grinder outlet temperature and the set value detected in the first step and outputting the difference; Compensate the grinder outlet temperature to the output signal output in the third step to obtain the hot air flow rate setting value and output a control signal, and compensate the grinder outlet temperature to the output signal output in the third step to compensate the cold air flow rate set value. And a fourth step of adjusting a quantity of cold air gas and hot air gas entering the grinder by outputting a control signal. The method of claim 2, Blowing flow rate according to the amount of coal supply is calculated by the following equation 1, the mill control method of the pulverized coal installation. Equation 1 .... Y1 = a (X-b) + c Here, X is the amount of coal supply, b is the lowest amount of coal supply, c is the minimum blowing flow rate for the lowest amount of coal feeding, a is a proportionality constant, and Y1 is a blowing flow rate conversion value according to the feeding amount. The method of claim 2, The hot-air flow rate setting value is calculated | required by following formula 2, The grinder control method of the pulverized coal installation. Equation 2 .... Y2 = α- (β + 50.0) × K1 Where Y2 is a hot air flow rate setting value, α is a blow flow rate control output value, β is a mill exit temperature control output value, and K1 is a mill exit temperature compensation factor. The method of claim 2, The cold air flow rate setting value is calculated by Equation 3 below. Equation 3 ... Y3 = α- (β + 50.0) × K2 Where Y3 is a cold air flow rate setting value, α is a blow flow rate control output value, β is a mill outlet temperature control output value, and K2 is a mill outlet temperature compensation factor.