KR970003633B1 - A checking device & control method of blowing quantity - Google Patents

Abstract

The present invention is about measurement and control apparatus of coal dust blowing by channel blowing quantity in blast furnace which can be stabilized coal dust blowing operation of providing optimum equal coal dust blowing quantity and can be stabilized operation control in blast.The present Measurement and control apparatus comprise detecting sensor of blowing quantity outputting changing temperature continuously according to inflowing of coal dust and heating isothermal; signal processing site outputting difference of input temperature signal and standard temperature signal and receiving detected temperature signal by comparing said temperature signal with standard temperature signal; air supply pipe connected at one side and a number of ventilation pipe at the other side, air distribution system which said ventilation pipe connect in compounded port of coal dust feed channel individually, automatic control valve generating current resistance in current of coal dust by introjection regular amount in coal dust feed channel from said ventilation pipe controlled opening to control signal provided said signal processing site.

Description

Measurement control device of blowing amount of pulverized pulverized coal injection flow path and its control method

1 is an overall configuration diagram of the measurement control device for each pulverized coal injection flow path according to the present invention.

2 is a process configuration diagram of a control device for pulverized coal injection flow paths according to the present invention.

3 is a block diagram of a blow amount detection sensor provided in the blow amount measurement control apparatus according to the present invention.

4 is a process operation sequence diagram of a blow-off measurement control apparatus according to the present invention.

5 is a graph showing a temperature decrease trend curve obtained in a blow-off measurement control apparatus according to the present invention.

6 is a flow chart of a blowing amount control method according to the present invention.

7 is a system diagram of a general pulverized coal injection facility.

* Description of the symbols for the main parts of the drawings *

10: blown amount detection sensor 17: thermocouple

20: signal processing unit 24: relay

30: process computer 50: air distributor

55: air supply pipe 60: automatic control valve

315: air blower 37: pulverized coal distributor

320: pulverized coal supply passage (Raceway) 325: blast furnace

S: power

The present invention relates to an apparatus and a method for measuring the pulverized coal injection situation for each pulverized coal injection passage and controlling the amount of injection in a pulverization coal injection facility (PCI: Pulverization Coal Injection) used as a heat source of the blast furnace. Equipped with an injection amount detection sensor and controlling the flow rate of the pulverized coal injection flow path in accordance with the data obtained by the injection amount detection sensor, to stabilize the pulverized coal injection operation, and thereby to adjust the pulverized coal of the blast furnace It relates to a flow rate measurement and control device and method for each flow path.

A system of a pulverized coal injection plant of a typical blast furnace is shown in FIG.

The pulverized coal injection facility 300 includes a plurality of pulverized coal storage hoppers 310a, 310b, 310c, and a pulverized coal main supply pipe 312 is connected to a lower portion thereof, and one side of the pulverized coal main supply pipe 312 is air. An air blower 135 is mounted, and the pulverized coal distributor 317 is mounted on the pulverized coal main supply pipe 312. The pulverized coal distributor 317 is connected to the pulverized coal main supply pipe 312 into which pulverized coal is introduced, and on the other side, a plurality of pulverized coal supply flow paths 320 are formed (34) to uniformly distribute the pulverized coal. Each pulverized coal supply flow path 320 is connected to a plurality of (34) pulverized coal supply holes 330 in a circumferential direction of the blast furnace 325 at predetermined intervals.

In addition, each of the pulverized coal supply passages 320 is formed with a purge air pipe 320a close to the pulverized coal distributor 317, respectively. The pulverized coal injection facility 300 as described above is supplied to the pulverized coal distributor 317 by the air blower 315 of the pulverized coal dropped from the pulverized coal storage hopper 310a, 310b, 310c to the pulverized coal main supply pipe 312. The pulverized coal is distributed at the same pressure and flow rate into each pulverized coal supply flow path 320, and the pulverized coal through the pulverized coal supply flow path 320 is introduced by a uniform blowing amount in the circumferential direction of the blast furnace 325. In the inside, it is possible to produce stable molten iron by uniform melt reduction in the circumferential direction.

However, in the conventional pulverized coal injection facility 300 as described above, the difference in the pulverized coal injection amount occurs for each of the 34 pulverized coal supply flow paths 320, thereby preventing the operation of the stable pulverized coal injection facility 300, and the unstable management is unstable. Is generated. In particular, when any one of the pulverized coal supply passage 320 is blocked, the pulverized coal supply port 330 is not supplied to the pulverized coal, causing a huge operation failure of the blast furnace 325, in this case, each of the pulverized coal supply passage ( It is penetrating this by supplying air to the purge air pipe 320a provided in 320, but it has a problem that it takes a long time before this operation is made.

It is not possible to directly measure the pulverized coal inflow amount of the 34 pulverized coal supply flow path 320, but only when the pulverized coal supply flow path 320 is blocked, the temperature of the pulverized coal supply flow path 320 in which the pulverized coal does not flow is You will only know when it drops to room temperature. On the other hand, in a method different from the above, the pulverized coal injection situation is visually observed through a piercing glass (not shown) fired on the blast furnace, or the outer shell temperature of the pulverized coal supply flow path 320 is measured. Although the amount was to be measured, it was difficult to grasp the pulverized coal injection amount by the pulverized coal supply flow path 320 because the error occurred largely due to the temperature deviation according to the season.

The present invention is to solve the above-mentioned conventional problems, by measuring the fine coal injection state accurately for each pulverized coal supply flow path, and by using the result to control the pulverized coal injection port of each pulverized coal supply flow path, Through the pulverized coal injection flow path of the improved blast furnace to provide a uniform pulverized coal injection through it provides a measurement and control device.

In addition, the present invention provides a fine coal injection amount control method that can achieve the stabilization of the sulfur by optimally controlling the fine coal injection amount.

In order to achieve the above object, the present invention is equipped with a plurality of pulverized coal storage hopper, the lower part is equipped with a pulverized coal main supply pipe having an air blower, the pulverized coal distributor and the pulverized coal supplied to the pulverized coal distributor In the pulverized coal injection flow rate measurement and control device of the pulverized coal injection flow path having a flow path, each of the pulverized coal injection flow path is mounted in each of the pulverized coal supply flow path is heated to a constant temperature, a plurality of continuous output of the temperature that changes as the pulverized coal flows Blown amount detection sensor; A signal processor which receives the detected temperature signal electrically connected to the blown amount detection sensor, transmits the temperature signal to a process computer, compares it with a reference temperature signal, and outputs a difference between the input temperature signal and the reference temperature signal as a control signal; ; An air main supply pipe is connected to one side, and a plurality of air supply pipes are connected to the other side, and the air supply pipes are each connected to a mixing port of the pulverized coal supply flow path; Each of the plurality of air supply pipes is mounted, and the opening degree is adjusted according to the control signal provided from the signal processing unit, thereby introducing a predetermined amount of air from the air supply pipe into the pulverized coal supply flow path, thereby providing flow resistance to the flow of pulverized coal. By providing an injection amount measurement and control device for the pulverized coal injection flow path of the blast furnace, characterized in that it comprises an automatic control valve for generating a.

In addition, the present invention, in the fine coal injection amount control method, the step of heating the blowing amount detection sensors respectively mounted in the pulverized coal supply passage; Detecting the temperature of the blown amount detection sensor and inputting it to a process computer; Counting time from set point (H) to (L) at the process computer; Comparing the counting time with the reference time; If the counting time and the reference time do not coincide, comparing whether the counting time is greater than the reference time; If the counting time is greater than the reference time, reducing the opening degree of the automatic control valve for controlling the flow rate of air provided to the pulverized coal supply passage to reduce the air supply amount; When the counting time is less than the reference time by providing a method for controlling the pulverized coal injection amount comprising the step of increasing the amount of air supply by expanding the opening degree of the automatic control valve for controlling the flow rate of air provided to the pulverized coal supply flow path.

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

In the blown amount measuring and control device 1 of the present invention, as shown in FIGS. 1 and 2, the blown amount detection sensor 10 is mounted on each of the pulverized coal supply flow paths 320, respectively, and the blown amount detection As shown in FIG. 3, the sensor 10 has a metal ring-shaped body 12 through which the pulverized coal supply passage 320 penetrates to the center, and a plurality of holes are formed at one side of the body 12 so as to be electrically connected. The heating element 15 heated by the heating element 15 is mounted, and the heating element 15 is connected to a power source through the signal processing unit 20 which will be described later. In addition, a thermocouple 17 is inserted into the other side of the body 12, and the thermocouple 17 converts the temperature of the body 12 into an electrical signal and transmits the signal to the signal processor 20.

In addition, the signal processing unit 20 to which the plurality of 34 injection amount detection sensors 10 are electrically connected to each other is a temperature signal of the thermocouple 17 through the inverter 22 as shown in FIG. 2. Is electrically input, and the signal processing unit 20 is also connected to the wires 15a connected to the plurality of heating elements 15 through a plurality of relays 24, and is a process computer that is a control computer of pulverized coal injection facility. 30 is connected to the DDC controller (Direct Digital Controller) 32 and the ICC controller (Instrument Communicating Computer) (34). In addition, the signal processing unit 20 is also electrically connected to the automatic control valve 60 mounted on the air supply branch pipe 55 of the air distributor 50 to be described later. In addition, an air distributor 50 having a plurality of air supply pipes 55 connected to the pulverized coal supply flow path 320 through the mixing port 27, respectively, is connected to the main air supply pipe 51 to one side of the compressed air. Are introduced, and the air supply branch pipe 55 is equipped with an automatic control valve 60, and the automatic control valve 60 has an opening degree according to the control signal output from the signal processing unit 20. It is automatically adjusted to adjust the flow rate of air flowing in the air supply pipe (55).

Reference numerals 28a and 28b are alarm devices sent from the signal processor.

According to the present invention configured as described above, when the pulverized coal is charged into the blast furnace 325 through the 34 pulverized coal supply passages 320, the heating element () of the injection amount detection sensor 10 mounted on each pulverized coal supply passage 320 is provided. 15, a proper amount of current is supplied from the power source S through the signal processing unit 20 to raise the ring-shaped body 12 to 140 ° C or more, and then the power source is cut off. Then, when the pulverized coal injection is made in such a state, the temperature of the body 12 is gradually lowered by the movement of the pulverized coal maintaining approximately 60 ° C., and finally, the temperature of the pulverized coal falls. At this time, the temperature decrease rate of the body 12 is faster the more the flow of pulverized coal is represented by the following formula (1).

T (t) = 60 + 80 exp [− (C ₁ V ^0.8 -C ₂ ) t]... … … … … … … … … … … … … … … … … (One)

here,

V: pulverized coal flow rate

t: time after power off of heating element

C ₁ , C ₂ : constant

T is the temperature measured in the thermocouple

That is, the temperature of the body 12 decreases as the amount of pulverized coal injection increases, and such temperature change is continuously detected by the thermocouple 17 inserted into the body 12 and input to the signal processing unit 20.

FIG. 5 is a graph showing the temperature variation as the differential amount passes through the blowing amount detection sensor 10. The graph curves the temperature change for each time zone 15 as the thermocouple 17 by cutting off the power supply of the heating element 15 while raising the temperature of the body 12 to 140 ° C. or higher. It is. The curve indicated by the zero point (a) is a case where the amount of pulverized coal blown is smaller than the curve indicated by the point (b), which shows that the temperature of the body 12 decreases slowly compared with the curve (b) which has a relatively high amount of pulverized coal injection. have. Therefore, the increase in the blowing amount of pulverized coal is such that the temperature of the body 12 is drastically lowered as in Equation (1).

Meanwhile, the signal processor 20 transmits the temperature signal input from the thermocouple 17 to the process computer 30, respectively, and the printer 36 and the monitor in the process of passing through the DDC controller 32 and the ICC controller 34. A temperature signal is output on (38a) (38b), and the temperature signal inputted to the process computer 30 is compared with a reference signal representing the optimum amount of blowing in advance and the control signal corresponding to the difference is returned to the signal processor. And information related to the control signal is also output on the printer 36 and the monitors 38a and 38b in the process computer 30 as well. On the other hand, the control signal input to the signal processing unit 20 transmits the high level alarm device 28a or the low level alarm device 28b according to the type, and the signal processing unit 20 has a respective air supply pipe ( 55 to provide an electrical control signal to the automatic control valve 60 installed in proportion to automatically control the opening degree proportionally, thereby controlling the amount of air from the air distributor 50 for each pulverized coal supply flow path 320. .

4 shows a method of extracting data relating to the amount of pulverized coal blown with respect to one blowing amount detection sensor 100. As shown in FIG. This counts the time t at which the process computer 30 decreases the temperature of the blowing amount detection sensor 10 from a previously set point H to the set point L and decreases. , The measurement coefficient time (t) is compared to the reference base (tset) indicating the optimum blowing amount, and if the counting time (t) is short, this indicates that the amount of fine coal dust actually injected is greater than the optimum fine coal injection amount. The process computer 30 instructs the command to open the automatic control valve 60 through the signal processing unit 20, and the opening degree is expanded so that a large amount of air is supplied to the pulverized coal supply passage 320. Inflowing into the mixing port 27 increases the pulverized coal flow resistance of the pulverized coal supply flow path 320, thereby reducing the amount of excessive pulverized coal injection.

On the other hand, if the counting time t is longer than the reference time tset, this indicates that the amount of pulverized coal actually injected is less than the optimal pulverized coal injection amount, and thus the process computer 30 is automatically controlled through the signal processing unit 20. The command to reduce the opening of the valve 60 is to be commanded so that a smaller amount of air is supplied to the pulverized coal supply passage 320 and the pulverized coal flow resistance is reduced to increase to the optimum pulverized coal injection amount.

Then, when the opening degree adjustment of the automatic adjustment valve 60 is completed, the injection amount detection sensor 10 is re-heated again, and the re-detection operation of the pulverized coal injection amount as described above is performed, thereby providing the respective pulverized coal supply flow paths 320. Optimum pulverized coal injection for is possible. This series of pulverized coal injection control procedures are shown as steps 10 through 140 in FIG.

As described above, according to the present invention, since the optimum uniform fine coal injection amount is supplied for each fine coal supply flow path 320, the fine coal injection operation is stabilized, and the operation management of the blast furnace is stabilized, thereby achieving the optimum operation management. .

Claims (3)

Pulverized coal storage hopper 310a, 310b, 310c is provided with a plurality of pulverized coal main supply pipe 312 having an air blower 35, the pulverized coal main supply pipe 312 is equipped with a pulverized coal distributor 317 And, in the pulverized coal injection flow rate measurement and control device of the pulverized coal injection passage 300 having a pulverized coal supply passage 320 distributed in a plurality in the pulverized coal distributor 317, each of the pulverized coal supply passage 320 A plurality of blown-out detection sensors 10 which are mounted on the heated to a predetermined temperature and continuously output a temperature which changes as the pulverized coal is introduced; Receives the detected temperature signal electrically connected to the blown amount detection sensor 10, and transmits the temperature signal to the process computer 30 to compare with the reference temperature signal, and controls the difference between the input temperature signal and the reference temperature signal A signal processing unit 20 which outputs as a signal; An air main supply pipe 51 is connected to one side, and a plurality of air supply pipes 55 are connected to the other side, and the air supply pipes 55 are respectively connected to the mixing port 27 of the pulverized coal supply flow path 320. An air distributor 50; Each of the plurality of air supply pipes 55 is mounted, and an opening degree is adjusted according to a control signal provided from the signal processing unit 20 to the pulverized coal supply flow path 320 from the air supply pipes 55. A pulverized coal injection flow rate measurement and control device for the blast furnace coal injection flow path, characterized in that it comprises an automatic control valve (60) for generating a flow resistance in the flow of pulverized coal by introducing a predetermined amount of air. According to claim 1, wherein the blowing amount detection sensor 10 is provided with a metal ring-shaped body 12 through which the pulverized coal supply flow path 320 penetrates in the center, the heating element is heated by electricity to one side of the body 12 15 is mounted, and the thermocouple 17 is inserted into one side of the heating element 15 to provide a temperature signal to the signal processing unit 20, the injection amount measurement and control device for each pulverized coal injection flow path of the blast furnace. A method for controlling fine coal injection, the method comprising: warming an injection amount detection sensor (10) mounted respectively on the pulverized coal supply flow path (320); Detecting (114) (116) the temperature of the blowing amount detecting sensor (10) and inputting it to a process computer (30); Counting 118 the time from set point H to L in process computer 30; Comparing the counting time with the reference time (120); If the counting time and the reference time do not match, comparing the counting time with the reference time (122); If the counting time is greater than the reference time step (124) to reduce the opening amount of the automatic control valve 60 for controlling the flow rate of air provided to the pulverized coal supply passage 320; When the counting time is less than the reference time pulverized coal injection, characterized in that for expanding the opening degree of the automatic control valve 60 for controlling the flow of air provided to the pulverized coal supply passage 320 to increase the air supply amount (126) Quantity control method.