KR20030029383A - Method for regulating the temperature of furnace using the character of coal itself - Google Patents

Abstract

PURPOSE: A method for controlling furnace heat of blast furnace according to characteristics of pulverized coal is provided to control furnace temperature stably by preventing sharp temperature fluctuation in the furnace according to exothermic characteristics of coals blended to manufacture pulverized coal. CONSTITUTION: In a control method for controlling temperature inside blast furnace according to characteristics of pulverized coal supplied into blast furnace(1), the method for controlling furnace temperature of the blast furnace according to characteristics of pulverized coal comprises first step of forming and storing data table according to characteristics of each of coals; second step of calculating the total stock of pulverized coal stored in coal preparation storage vessel(10), PCI (pulverized coal injection) coal storage vessel(20), fine coal storage vessel(50) and feed tank(60) before changing thereof when adjusting PCI coal type and blending ratio, and calculating in a process computer(100) a time in which the total coal stock can be injected by variation of pulverized coal injection quantity; third step of setting in an upper controller a pulverized coal injection starting time after change using the pulverized coal injection time of coals before change calculated in the second step; fourth step of calculating heating value deviation before and after change according to change of the PCI coal type and blending ratio; and fifth step of injecting coals into the blast furnace(1) by resetting the pulverized coal injection quantity after changing of the PCI coal type and blending ratio by the heating value deviation.

Description

Method for regulating the furnace furnace according to pulverized coal characteristics {Method for regulating the temperature of furnace using the character of coal itself}

The present invention relates to a blast furnace control method according to the pulverized coal characteristics, and more specifically, to mix and supply coal such as fine coal, semi-anthracite coal for the production of pulverized coal used as fuel in the blast furnace, respectively The present invention relates to a blast furnace control method according to pulverized coal characteristics according to the pulverized coal characteristic which can stably control the furnace temperature by preventing the temperature inside the furnace from suddenly changing according to the heat generation characteristics of the furnace.

In blast furnace operation in steel mills, a large amount of pulverized coal, which is an alternative raw material of coke, is blown and used. The purpose of injecting pulverized coal is to solve the environmental pollution problem that occurs during the manufacturing process of coke, and also because it is cheaper than coke and can exhibit the same calories. The purchase price per ton of coke is about 100,000 won, and the purchase price per ton of coal, which is a raw material of pulverized coal, is about 4 to 70,000 won. Therefore, when a large amount of low-cost calls are used in the blast furnace, the cost reduction is very effective.

For example, the amount of coke needed to produce 1 ton of molten iron is 485 kg / TP, although coking and iron ore are charged into the blast furnace to produce molten iron. / TP + fine coal 135kg / TP) can reduce the environmental pollution by suppressing the use of coke. In addition, by using not only one kind of coking coal, but also a mixture of coking coal, or anthracite coal at the same time, not only suppresses the amount of coke used, but also reduces costs.

First, a process for using pulverized coal in the conventional blast furnace 1 will be described with reference to FIG. 1. In the process of manufacturing pulverized coal, coal coal is stored in the PCI call tank 20 through the belt conveyor 15 by controlling the coking coal and semi-anthracite coal at a predetermined ratio in the coal tank storage tank 10. PCI stands for Pulvurized Coal Injection. The call stored in the PCI call reservoir 20 is dropped into a mill 30, which is a pulverized coal manufacturing facility, through a call feeder 25 and converted into a fine state while grinding. The particulate call is dried and transported by hot gas waste gas and then transferred to the bag filter 40 (Bag Filter). The waste gas used for the transfer is discharged into the atmosphere, and the pulverized coal is stored in the fine storage tank 50. Pulverized coal is stored in the pulverized coal storage tank (50) through the distribution valve 70 transfer to the air (air) by the charging sequence with nitrogen by the nitrogen compressor (4) in the feed tank (60) of the blowing facility (3) It is blown into each tuyere 2 provided in the blast furnace (1) through. The amount of pulverized coal to be blown is set by an operator. The pulverized coal blowing operation as described above is repeatedly performed until the blast furnace is stopped due to facility work. Reference numeral 80 denotes a fine coal injection controller for controlling the overall apparatus.

However, in the conventional method of blowing pulverized coal into the blast furnace 1 according to the kind of call as mentioned above, the following problem arises.

First, in case of changing the type of coal and the combination (adjustment of coking coal and anti-anthracite coal) according to the injection of a large amount of coal, the amount of coal injection is the same as before the change. There was a problem that the fluctuations in the furnace were so severe that the prediction of the constant fluctuation and the control of the furnace were difficult.

Second, the rapid rise of furnace heat in the blast furnace raises the silicon (Si) in the molten iron component, causing a decrease in the quality of the molten iron. Also, there is a risk of large-scale accidents due to overheating of the furnace due to overcooling. There was a problem.

The present invention is to solve the above problems, an object of the present invention is the calorific value according to the type of call before and after the change in the case of changing the call type or the mixing ratio such as fine coal or semi-anthracite coal in the pulverized coal blowing operation to the blast furnace By converting the conversion into the PCI hourly blowing amount by using the difference of, it is to provide the furnace control method of the blast furnace according to the pulverized coal characteristics that can manage the furnace temperature stably and uniformly.

Another object of the present invention is to provide a blast furnace control method according to the pulverized coal characteristics that can prevent the large-scale accidents such as the rise of the molten iron quality and the blast furnace shutdown by controlling the furnace temperature constant and stably in the blast furnace. have.

Another object of the present invention is to control the furnace blast furnace according to the pulverized coal characteristics, which can prevent the ventilation of the furnace and the gas drift in the furnace by the furnace stability, and also increase productivity and reduce fuel costs by the furnace bottom temperature and furnace aging. To provide.

1 is a schematic configuration diagram of a conventional PCI manufacturing and blowing facility,

2 is a kind and characteristic data of a call classified according to the present invention,

3 is a schematic configuration diagram of a manufacturing and blowing facility in which the method of the present invention is performed;

4 is a block diagram for pulverized coal calculation and blowing time calculation of the present invention;

5 and 6 are graphs showing the set state of the pulverized coal injection time;

7 is a block diagram for calculating deviation calorific value and blown amount of the present invention;

8 and 9 are graphs showing the amount of blowing at the time of changing to a high calorific value and a low calorific value.

※ Explanation of symbols about main part of drawing ※

1: blast furnace 2: windball

3: pulverized coal injection lance 4: nitrogen compressor

10: suntan tank storage tank 10A: (suntan tank storage tank) weight detector

11, 21: weighing machine 15: belt conveyor

20: PCI Call Storage 20A: (PCI Call Storage) Weight Detector

25: call feeder 30: wheat

35: outlet 40: bag filter

50: Differential Storage Tank 50A: (Differential Storage Tank) Weight Detector

60; Feed tank 60A: (feed tank) weight detector

65: pickup 70: distribution valve

80: Pulverized coal injection controller 90: Pelletizing process computer

100: process computer 200: host controller

300: blast furnace process computer

The blast furnace control method according to the pulverized coal characteristics of the present invention for achieving the above object, the first step of constructing and storing a data table according to each characteristic of the call; When adjusting the PCI call type and compounding ratio, the total inventory of the pulverized coal stored in the first input tank storage tank 10, the PCI call storage tank 20, the differential storage tank 50 and the feed tank 60 before the change is calculated, A second step of calculating a time for which the inventory amount can be blown by the pulverized coal blowing amount; A third step of setting the pulverized coal injection start time after the change by using the pulverized coal injection time of the pre-change call calculated in the second step; Calculating a deviation calorific value before and after the change according to the PCI call type and the blending ratio; And a fifth step of setting the amount of pulverized coal blown after the change of the call type and the mixing ratio by the deviation calorific value and blowing into the blast furnace 1.

Hereinafter, the furnace control method according to the pulverized coal characteristics of the present invention with reference to the accompanying drawings in detail as follows.

First, a data table according to a call type will be described with reference to FIG. 2. Types of coal (coal) made from pulverized coal, which is an alternative to blast furnace, are classified into uncoal coal AI and semi-anthracite JO, and the characteristics of moisture (TM), volatile matter (VM), and calorific value (CV) are measured for each. And table and then store on a process computer (not shown). The tabled data is stored in the memory element and read out when a change in the compounding ratio of a call is generated and applied to the calculation. The above classification is an example, and it is possible to classify in smaller range or in large range.

The necessity of the furnace control in the conventional blast furnace 1 is as follows. For example, when the pulverized coal prepared during the operation is blown into the blast furnace 1 using one of the pulverized coal (AI), and the coal powder for pulverized coal is supplied to supply new pulverized coal. If you want to use this 100% as one of (AI), the calorific value of uncoal coal is 7386-7548kCal / kg, so if you use the same uncoal coal, the variation of calorific value is not large, but if you use 100% of anthracite coal The range of calorific value is 7458-7910KCal / kg, which is a big difference from the calorific value before the change. Therefore, it is manufactured with fine powder using semi-anthracite coal and injected into the blast furnace (1). It becomes necessary.

3 is a schematic structural diagram of a PCI manufacturing and blowing facility in which the method of the present invention is performed. As shown in the drawing, the tankard tank storage tank weight detector 10A for detecting the remaining amount of the coal tank storage tank 10, the call tank tank weight detector 20A for detecting the call residual amount of the PCI call tank 20, Further, there is further provided a (a differential storage tank) weight detector 50A for detecting the remaining amount of pulverized coal of the fine powder storage tank 50 and a (feed tank) weight detector 60A for detecting the residual amount of pulverized coal of the feed tank 60. The signals generated from the weight detectors 10A, 20A, 50A, and 60A are input to the process computer 100.

The data detected from the first tank storage tank weight detector (10A) and the call storage tank weight detector (20A) receives the weight of the call before the powder is manufactured from pulverized coal, respectively, to detect the weight, thereby Note that the weight of the pulverized coal is measured in the weight detectors 50A and 60A. Therefore, the weight measured from the weight detectors 10A and 20A is converted into the weight of the pulverized coal corresponding thereto and used in the next step. This weight conversion is performed in the process computer 100, and an equation for converting and calculating the weight of the call into the fine coal quantity (10B, 20B) is shown below.

(Equation 1)

T1 × WO21 = WO2T1, T1-WO2T1 = 10B,

Here, T1 is the total basis weight value of the call in the coal pelletization storage tank 10 before the change, WO21 is the moisture content of the call, WO2T1 is the total moisture content, and 10B is the pulverized coal amount of the coal pellet storage tank 10. For example, a process computer (in the weighing detector 10A) is currently stored in the unburned coal and is weighed by the weight detection signal output from the weighing machine 11 of the pair of coal feed tanks 10 before changing the call type or blending ratio. Assuming that the total weight (T1) of the detected fine coal sent to 100) is 400T and the moisture (WO21) is 8%, the total basis weight value 400T × water content (8.0 ÷ 100) for the coal feed tank 10 = 32T (total moisture content). Therefore, if the total moisture content is subtracted from the total basis value, the pulverized coal quantity 10B = 400-32 = 368 (T), which is the total basis value of the call converted to the pulverized coal quantity of the coal pit storage tank 10. to be.

In addition, the total basis weight value of the call reservoir 20 is detected from the weighing machine 21 and detected by the call reservoir weight detector 20A, which is also converted into the corresponding pulverized coal amount in the process computer 100. The equation to be converted is similar to the above equation and is as follows.

(Equation 2)

T2 × WO22 = WO2T2, T2-WO2T2 = 20B,

Where T2 is the weight of the PCI reservoir prior to modification, WO22 is the moisture content of the call, WO2T2 is the total moisture content, and 20B is the pulverized coal capacity of the PCI call reservoir. For example, if the total inventory weight of a pair of PCI call reservoirs 20 is 660T, and the moisture content is 8.0%, this is converted to the pulverized coal content, and the total basis weight value is 660T × water content 8.0% = 52.8T, 20B = 600-52.8 = 607.2T.

As described above, removing the water content weight from the total weight of the call removes the water contained in the call using waste gas of hot air in the process of crushing the call and stores it in the fine storage tank 50 to be blown into the blast furnace 1. It is to remove the amount of water evaporated at the time of call crushing in advance, and to calculate the amount of pulverized coal input into the actual blast furnace (1).

In contrast, the fine powder amount of the fine powder storage tank 50 and the fine coal feed tank 60 is the value detected from the fine powder storage weight detector 50A and the feed tank weight detector 60A without removing the water content because the moisture is already removed. Is transferred directly to the process computer 100 to calculate the fine coal quantity 50B and 60B, respectively. Thus, the process computer 100 stores the amount of each pulverized coal and the sum thereof. As described above, using the sum of the pulverized coal storage tank 10, the PCI call storage tank 20, the differential storage tank 50, and the pulverized coal of the feed tank 60, Equation 3 Calculate using

(Equation 3)

BFT = (10B + 20B + 50B + 60B) ÷ Current Pulverized Coal Blowing Volume (T / Hr),

Here, BFT is the time required before the call is injected into the blast furnace, 10B is the pulverized coal output of the coal pit storage tank, 20B is the pulverized coal output of the PCI call reservoir, 50B is the pulverized coal output of the grinding tank, and 60B is the pulverized coal output of the feed tank. it means. For example, if the currently set pulverized coal injection amount in the blast furnace is 60T / Hr, and the total number of calls before the change, that is, the pulverized coal quantity (BFT) that can be injected into the blast furnace is 1210.2T, 1210.2T ÷ 60T / Hr = 20 hours 17 minutes. This 20 hours and 17 minutes is the time before the change can be blown into the blast furnace with pulverized coal. As described above, the blast furnace injection time calculated by the processor computer 100 according to the pulverized coal injection amount and the remaining inventory amount before the call type change is described with reference to FIG. 4, and the blast furnace process control computer is operated by the upper controller 200 or the upper controller 200. Transmitted in real time (not shown). 4 is a block diagram of a control unit in which the method of the present invention is performed, where 100 is a process computer that calculates the inventory amount taking time by collecting the above-described fine coal quantity.

The remaining blast furnace injection time of the pulverized coal calculated as described above is calculated by subtracting 3 hours (3Hr), which is a delay value of the furnace fluctuation time caused by the change of the call fuel, to calculate the in-blast furnace start time after the call fuel change. do. This is a value calculated from experience or performance data after changing the pulverized coal injection amount during the operation of the blast furnace, and it is inferred from the fact that the furnace heat inside the blast furnace changes after 3 hours when the pulverized coal injection amount is changed. This delay time may be represented by Equation 4 below.

(Equation 4)

BFT1 = BFT-3 (Hr)

Here, BFT is the blast furnace injection time before change, BFT1 is the blast furnace start time after change. Equation 4 is embedded in the upper controller 200, and when the pulverized coal injection time calculated by Equation 3 is input, according to the pulverized coal injection start setting time step, the blast furnace process computer 300 is displayed as shown in FIG. 7. ). Resetting the injection start setting time as shown in Equation 4 generally means that if the fluctuation of the pulverized coal injection amount can be known after 3 hours, the change before the call is undifferentiated, and the amount of pulverized coal injection is 3 hours before the injection is completed. After the change, the furnace heat according to the pulverized coal injection after the change can be kept the same as the furnace heat due to the pulverized coal injection after the change. However, in this state, the calorific value has not been corrected yet.

After calculating the starting time for injecting pulverized coal after changing the call type or blending ratio as described above, the pulverized coal compensation step is performed by calculating the calorific value deviation before and after the change in the call type, the fine coal, the anti-anthracite coal adjustment (ie blending). The following equations are for calculating the calorific value. This is a necessary process to control the furnace temperature inside the blast furnace to the set temperature constantly.

(Eq. 5)

K1 = PCR × heating weight (X1) × injection ratio (R1)

(Equation 6)

K2 = PCR × heating weight (X2) × injection ratio (R2)

(Eq. 7)

K = K1-K2,

Here, K is calorific value, K1 is calorie value before call change, K2 is calorie value after call change, PCR is fine coal injection amount (KG / T) and weighted calorific value (X1) is 1 calorie value , The weighted calorific value (X2) is the calorie value of the call type after the change, the blowing ratio (R1) is the call usage ratio before the change, the blowing ratio (R2) represents the call usage ratio after the change.

Dividing the amount of pulverized coal used in a day by dividing the amount of pulverized coal produced in a day, it is possible to obtain the amount of pulverized coal taken to produce 1 ton of molten iron, which is expressed by PCR. The calorific value of the call (coal) classified according to each characteristic is the weighted calorific value, and the call mix ratio before the change is represented by the intake ratio, so that the call types before and after the change are processed in the coal processing process computer 90 (computer controlling coal supply). When it is transmitted to the computer 100, the powdered coal calorific value K1 before the change is calculated by Equation 5. In addition, after the change, the fine coal calorific value after the change is calculated by subtracting the fine coal calorific value after the change from the fine coal calorific value before the change, and the calorie compensation value before and after the call change is calculated. The calorie compensation value is calculated by the process computer 100, calculated as the pulverized coal injection amount, and transmitted to the blast furnace process computer 300. The calorie compensation value is transmitted to the pulverized coal controller 80. In the pulverized coal controller 80, when the deviation calorie K calculated in Equation 7 is divided by the calorie of 1T of pulverized coal, the amount of pulverized coal powder to be injected after the change is calculated. Is calculated. This is shown in Equation 8.

(Eq. 8)

K _X = K ÷ P1,

The process computer 100 transmits the current mined coal injection amount minus the K _X value to the blast furnace process computer 300. The transmitted value is the amount of pulverized coal blown by calculating the deviation calorific value as blown amount. The blast furnace process computer 300 transmits this value to the pulverized coal controller 80 so that the pulverized coal is blown by the pulverized coal controller 80 at the start injection time after the call type change.

The method of the present invention as described above will be described using specific examples.

As shown in FIG. 2, it is assumed that data by type of uncoal coal (A-I) and semi-anthracite (J-O) classified according to characteristics of a call are stored in the process computer 100 in a tabled state. In order to change the pulverized coal to 60T / Hr in the blast furnace (1) due to the shortage of pulverized coal during the operation, to change from 100% unburned coal (A) with 7368 Kcal / Kg to 100% semi-anthracite (J) with 7910 Kcal / Kg Input the call signal of call type and mix ratio.

When the call change signal is input, the process computer 100 receives the weight detector 10A of the first shot tank storage 10, the weight detector 20A of the call storage tank 20, and the weight detector of the differential storage tank 50 ( 50) and the weight value input from the weight detector 60A of the feed tank 60, respectively, 1) to calculate the pulverized coal quantity limiting the water content of the coal pellet storage tank 10 before the pulverized coal call change; Calculate the pulverized coal limiting the water content of the PCI call tank 20, 3) Calculate the pulverized coal amount stored in the pulverized storage tank 50 and the feed tank 60, 4) Calculate the total amount of pulverized coal residue before the call change. . After calculation of the total amount of pulverized coal, the process computer 100 calculates a remaining blowing time for blowing pulverized coal into the blast furnace 1.

For example, before the change, the inventory of the first tank input tank 10 is 400T, the inventory of the PCI call tank 20 is 660T, the inventory 50B of the differential storage tank 50 is 150T, and the inventory of the feed tank 60 ( Assuming that 60B) is 235T and the water content of the call is 8%, the pulverized coal amount of the first input tank storage tank 10 is 368T (10B) by the above equations 1 and 2, and the pulverized coal quantity of the PCI storage tank 20 is Is 607.2T (20B). At this time, the pulverized coal of the fine storage tank 50 and the feed tank 60 is used directly without removing the moisture content because the pulverized coal is already removed. When the pulverized coal inventory before the call change is calculated as described above, the pulverized coal inventory is added to calculate the total amount. The total amount is calculated by the above equation 3. In the above example, the total pulverized coal is 1360.2T, which is divided by the current pulverized coal injection, resulting in 1360.2 ÷ 60 = 22 hours 40 minutes, during which time the pulverized coal can be blown. When the residual coal injection remaining time is calculated as described above, the process computer 100 transmits the calculated value to the host computer. The host computer 200 uses this value to calculate the starting time for pulverized coal injection after the change using Equation 4 above. That is, after 22 hours 40 minutes-3 hours = 19 hours 40 minutes is the start time of pulverized coal injection.

5 and 6 show an example of the above-described change in the pulverized coal injection start time. This is not based on the above calculation formula for the pulverized coal quantity, but according to any blowing amount. 5 is based on the pulverized coal injection remaining time calculated by Equation 3 in the process computer 100, and FIG. 6 is the blowing start time calculated by Equation 4. FIG.

For example, when the blowing amount is 20T, the blowing start time is 50 hours later. However, in FIG. 6, when the blowing amount is 20T, the blowing start time is about 47, and it is understood that the blowing start time is about 3 hours. In addition, when the blowing amount is 40T, the blowing start time is 26 hours, but it can be seen that in FIG.

In addition, when the pulverized coal call type is applied in terms of fuel ratio using the calorific value deviation generated by the change from the fine coal (A) to the anthracite coal (J), it is calculated using the equations (5) to (7). The calculation of the input calorie difference when changing the call type from to anthracite (J) is as follows.

K = K1-K2

= {[(PCI 60T / Hr) × 1000kg / T × Calories (BI (A): 7386Kcal / kg) × 24Hr / D ÷ Production (9000T / D)]}-{[(PCI 60T / Hr) × 1000kg / T × calories (CB (J): 7901Kcal / kg) × 24Hr / D ÷ Production (9000T / D)]} = 1181760 (Kcal / TP)-1264160 (Kcal / TP) = -82,400 (Kcal / TP) .

When the input calorific difference is converted into pulverized coal injection ratio (PCR / T-P),

Kcal / T-P (calorie unit) ÷ calories per kilogram of PCI (Kcal / Kg) → (Kg / T-P) =

PCR-82,400 Kcal / TP ÷ 7600 (Kcal / Kg) = -10.84 (Kg / TP) .

PCR (Kg / T-P) × Production (9000T / D) ÷ 24 (Hr / D) ÷ 1000 (Kg / T)

10.84 (Kg / TP) x 9000 (T / D) ÷ 24 (Hr / D) = -4.07 (T / Hr) .

The -4.07 (T / Hr) value is sent from the process computer 100 to the upper controller 200, which is the amount of fine coal injection by the variation calorific value before and after the change, and the upper controller 200 after the change from the current blowing amount. The pulverized coal injection amount minus the compensation calories is sent to the blast furnace process computer 300. In the blast furnace process computer 300, the pulverized coal is blown from the current pulverized coal injection amount at 3 hours before the total inventory before the change to the pulverized coal injection machine 80, that is, 19 hours and 40 minutes calculated from the start time of the pulverized coal injection. It automatically adjusts the blown amount per PCI hour calculated by the amount to 60-4. 07 = 55.9T / Hr. Therefore, as shown in FIG. 8, the pulverized coal amount decreases compared to the previous one, but the furnace heat can be controlled due to the increase in the calorific value after the change.

As another embodiment, the case where the ratio of the call type is changed from 40:60 to 60:40 of the uncoal and semi-anthracite coal is as follows. First, the amount of fine coal stocks of the coal-tanking tank storage tank 10 and the amount of fine coal stocks of the PCI call storage tank 20 are obtained, and the total amount of fine coal of the fine powder storage tank 50 and the feed tank 60 is obtained to calculate the total stock of fine coal. . The remaining total injection time of pulverized coal is calculated using the calculated total inventory. It is assumed that the remaining blowing time and the total inventory are the same as in the above embodiment.

In addition, the calorific difference introduced when using the blend change is calculated as follows.

{[(0.4 × PCI 60T / Hr) × 1000kg / T × Calories (BI (A): 7386Kcal / kg) × 24Hr / D ÷ Production (9000T / D)] + [(0.6 × PCI 60T / Hr) × 1000kg / T × Calorie (BI (A): 7901Kcal / kg) × 24Hr / D ÷ Production (9000T / D)]}-{[(0.6 × PCI 60T / Hr) × 1000kg / T × Calorie (BI (A): 7386Kcal / kg) × 24Hr / D ÷ Production (9000T / D)]-[(0.4 × PCI 60T / Hr) × 1000kg / T × Heat (BI (A): 7901Kcal / kg) × 24Hr / D ÷ Production (9000T / D)]} = 1,231,200-1,214,720 = 19,227 Kcal / TP.

If the difference in input calories is converted into pulverized coal injection ratio (PCR / T-P), it is as follows.

PCR = difference in calorific value (after changing the type of coal) ÷ heating weight (Kcal / Kg) of the changed call, which is 19227 (Kcal / TP) ÷ (0.6 × 7386 + 0.4 × 7801) = 2.53 (Kg / TP), When converted into PCI (T / Hr), 2.53 (Kg / TP) × 9000 (by PCR (Kg / TP) × production (9000 T / D) ÷ 24 (Hr / D) ÷ 1000 (Kg / T) T / D) ÷ 24 (Hr / D) ÷ 1000 (Kg / T) = 0.95 T / Hr.

In summary, the blast furnace process computer controls the pulverized coal control when the fine coal injection is set at 60T when the coal type mixture is changed from 40%, 60% to 60% and 40%, respectively. After 80 hours and 40 minutes at (80), the upper control unit 200 is transferred from the upper controller 200 to the blast furnace process computer 300 to blow 60.95T of the fine coal injection set amount plus 0.95T / Hr. Therefore, as shown in FIG. 9, the amount of pulverized coal injection increases, but the furnace heat of the blast furnace 1 is controlled by the characteristics of the pulverized coal due to the decrease in the calorific value.

According to the present invention, in the case of changing the call type or the mixing ratio of the fine coal or the anthracite coal, etc. during the pulverized coal injection operation to the blast furnace, it is converted into the PCI hourly blowing amount by using the difference in the calorific value according to the call type before and after the change. By applying the furnace temperature stably and consistently, it is possible to prevent large-scale accidents such as the increase of the charter quality and the blast furnace shutdown. In addition, the stabilization of the furnace can prevent the ventilation of the furnace and gas drift in the furnace, and also has the effect of increasing productivity and reducing fuel costs by stabilizing the furnace bottom temperature and aging.

Claims (4)

In the control method for controlling the temperature in the blast furnace in accordance with the characteristics of the pulverized coal supplied to the blast furnace 1, A first step of constructing and storing a data table according to each characteristic of the call; When adjusting the PCI call type and compounding ratio, the total inventory of the pulverized coal stored in the first input tank storage tank 10, the PCI call storage tank 20, the differential storage tank 50 and the feed tank 60 before the change is calculated, A second step of calculating, by the process computer 100, the amount of time that the inventory amount can be blown by the pulverized coal blowing variation; A third step of setting, by the upper controller 200, the pulverized coal injection start time after the change using the pulverized coal injection time of the pre-change call calculated in the second step; Calculating a deviation calorific value before and after the change according to the PCI call type and the blending ratio; And a fifth step of resetting the pulverized coal injection amount after the change of the call type and the mixing ratio by the deviation calorific value and blowing into the blast furnace (1). The method of claim 1, And a data table according to the call type in the first step is classified according to the size of coal, water content, volatile matter content, and calorific value. The method of claim 1, The pulverized coal characteristics of the pulverized coal is characterized in that the calculation of the pulverized coal stock in the second step is calculated by calculating the pulverized coal stock value as the weight value obtained by removing the water content from the weight values of the calls stored in the first coal storage tank 10 and the PCI call storage tank 20. The furnace control method according to the blast furnace. The method of claim 1, The pulverized blast furnace control method according to the pulverized coal characteristics, characterized in that the starting time for the pulverized coal injection in the third step is set by subtracting 3 hours from the starting time for the pulverized coal injection in the second step.