KR101205059B1 - Operating method of hot stove - Google Patents

Abstract

The present invention relates to a hot stove operation method, the sensing unit 27 detects the opening degree of the hot air valve 19a during the hot stove operation, and the determination unit 28 is provided from the sensing unit 27 Judging the opening degree information of the hot air valve 19a to determine whether the hot air path 10 is abnormal, and the controller 29 determines that the hot air path 10 is abnormal. And controlling the operation of the hot stove 10 to change from the three hot stove operation modes to the two hot stove operation modes.
The present invention has the advantage that can be operated stably the hot blast furnace and stable operation of the blast furnace when inevitably due to the problem of the installation of two hot stove operations.

Description

Operating method of hot stove

The present invention relates to a hot stove operating method, and more particularly, to a hot stove operating method for optimizing the temperature in the hot stove when two operations inevitably due to equipment problems.

Hot blast furnace is a facility that manufactures and supplies high temperature hot blast so that molten iron and slag are formed in blast furnace loaded with iron ore and coke.

The coke is combusted to form CO gas by the hot air supplied from the hot stove, and the CO gas heats, reduces and dissolves the iron ore while raising the descending charge layer.

It is an object of the present invention to provide a hot blast furnace operating method of controlling the blast furnace productivity in the same manner as in the third stage of operation by optimizing the temperature in the hot blast furnace inevitably due to equipment problems.

According to a feature of the present invention for achieving the object as described above, the present invention comprises the steps of detecting the opening of the hot air valve during the sensing unit operation hot stove; Determining, by the determination unit, the opening degree information of the hot air valve provided from the detection unit to determine whether the hot air path is abnormal; And if the control unit determines that the hot stove is abnormal, controlling the hot stove operation to change from the three hot stove operating modes to the two hot stove operating modes.

The hot stove operation operation mode circulates two hot stoves in which the abnormality does not occur in the sequence of combustion operation-standby operation-blowing operation, and thermally operates the hot stoves in which the abnormality occurs.

The hot stove combustion operation includes calculating the heat of the hot stove combustion; Calculating a hot stove dome temperature set value deviation, and determining whether the hot stove dome temperature set value deviation is less than a set value, and if the determined hot stove dome temperature set value deviation is less than a set value, waits for the hot stove combustion operation. Convert to driving.

If the determined hot stove dome temperature set value deviation is equal to or larger than the set value, the step of recalculating the heat of combustion through adjustment of the combustion air amount, the COG mixing ratio, and the mixed gas amount is performed again, and calculating the hot stove dome temperature set value deviation.

The set value of the hot stove dome temperature set value deviation is 100 ° C.

The hot stove standby operation is converted to a blow operation when the remaining hot stove that does not have an abnormality is converted to a combustion operation.

The hot blast blowing operation is to adjust the opening degree of the cold air supply valve (CBMCV) while monitoring the hot blast and wind temperature, and whether the hot blast back temperature, hot blast dome temperature deviation, wind temperature setpoint deviation is less than the set value, respectively And performing the determining, and converting the hot blast blowing operation into a combustion operation when the determined hot blast back temperature, the hot blast dome temperature deviation, and the wind temperature set variance are less than the set value, respectively.

If any one of the determined hot stove back temperature, hot stove dome temperature setpoint deviation, and wind temperature setpoint deviation is equal to or greater than each set value, the air blower air volume adjustment is performed and the cold wind supply valve (CBMCV) opening degree is adjusted while monitoring the hot stove and wind temperature. The steps are repeated.

The hot stove back temperature set value is 550 ° C., the hot stove dome temperature set value deviation is 100 ° C., and the wind temperature set value deviation is 50 ° C.

The two operation modes of the hot stove are circulated in a cycle of 50 minutes of combustion, 10 minutes of air, and 60 minutes of blowing.

The hot blast blowing operation adjusts the ratio of the blower air flow rate and the cold air supply valve (CBMCV) flow rate to 7: 3.

According to the present invention, when two hot stoves are inevitably operated due to equipment problems, the operation time of combustion-waiting-blowing of the hot stoves is changed, and the flow rate of the cold winds supplied to the hot stoves and the flow rate of the cold winds supplied to the mixed cooling chamber. Adjust.

Therefore, it is possible to maintain the molten iron temperature from the blast furnace similar to the three operation of the hot blast furnace, it is possible to operate the hot blast furnace stably, the blast furnace operation can be stably maintained, the blast furnace cost is maintained.

1 is a hot air facility showing a hot stove operation method according to the present invention.
Figure 2 is a valve configuration of a hot stove facility showing a hot stove operating method according to the present invention.
Figure 3 is a flow chart showing a hot stove operating method according to the present invention.
Figure 4 is a flowchart showing an embodiment of the first hot stove combustion operation of the hot stove operation method according to the present invention.
5 is a flowchart illustrating an embodiment of a second hot stove blowing operation among the hot stove operating methods according to the present invention;
6 illustrates a case in which three hot stoves are operated for one blast furnace (a) and two hot stoves are operated for one blast furnace by applying the hot stove operating method of the present invention due to hot stove abnormalities ( Graph showing the blast furnace temperature of b).
7 is a case in which three hot blast furnaces are operated for one blast furnace (a) and two hot blast furnaces are operated for one blast furnace by applying the hot blast furnace operating method of the present invention due to hot stove abnormalities ( Graph showing the molten iron temperature of b).

Hereinafter, embodiments of the present invention will be described in detail.

3, the sensing unit 27 detects the opening degree of the hot air valve 19a during operation of the hot air furnace 10 (S1) and the determination unit 28 as illustrated in FIG. 3. ) By determining the opening degree information of the hot air valve (19a) provided from the sensing unit 27, the step (S2) of determining whether there is an abnormality of the hot air path (10), and the control unit 29 of the determination unit 28 If it is determined that the hot stove 10 is abnormal, the hot stove operation may be controlled to be changed from the three hot stove operation modes to the two hot stove operation modes (S3).

If it is determined that the hot stove 10 is not abnormal, step S4 of maintaining three hot stove operating modes is performed.

Operation mode of two hot stoves means that the two hot stoves are operated normally except for the hot stoves of one of the three hot stoves. Normal operation is to circulate the two hot stoves in the combustion-atmosphere-blowing operation sequence.

In addition, the hot stove 10 in which the abnormality is performed performs a heat keeping operation for maintaining the temperature in the hot stove.

The thermal operation is to prevent the loss of the smoke and function in the hot stove 10 so that the hot stove can be stably operated when returning to normal operation of the hot stove having the abnormality. Since the hot stove thermal operation method is not the gist of the present invention, a detailed description thereof will be omitted.

As shown in FIG. 1 and FIG. 2, the hot blast furnace 10 includes a heat storage chamber 11, a combustion chamber 13, and a mixed cooling chamber 15, and alternately repeats combustion-air-blowing to generate hot air. Therefore, three hot stoves 10 are used per blast furnace. 1 and 2 show only one hot stove.

The hot stove 10 burns the gas (BFG, COG) and air for combustion in the combustion chamber 13, raises it to about 1250 ° C, and accumulates heat in a checker (not shown) disposed inside the heat storage chamber 11. After the heat storage process is completed, as the cold air flowing into the blower tube 17 is supplied to the combustion chamber 13 through the heat storage checker, the cold air takes heat of the checker into a hot air, and the hot air passes through the combustion chamber 13. The hot air pipe 19 is supplied to the blast furnace 30 via the mixed cooling chamber 15.

The hot blast furnace 10 keeps the blow valve 17a and the hot blast valve 19a closed until sufficient heat is accumulated in the checker of the heat storage chamber 11 to produce hot air supplied to the blast furnace 30. In addition, when sufficient heat is accumulated in the checker of the heat storage chamber 11, the flue valve 23a is closed, and the blow valve 17a and the hot air valve 19a are opened to open the blower tube 17 and the hot air tube 19. To keep.

The hot stove abnormality is determined by whether or not the opening degree of the hot air valve 19a is 100%.

If the opening degree of the hot air valve 19a is less than 100%, it is determined as a hot air path or more. When the opening degree of the hot air valve 19a is less than 100%, the hot stove dome temperature deviation corresponding to the roof portion of the hot stove 10 becomes large, and the blast furnace wind temperature deviation supplied to the blast furnace 30 becomes large, thereby making the blast furnace operation unstable.

The hot stove dome temperature deviation is a deviation between the hot stove temperature measured at the hot stove dome portion and the hot stove dome temperature set value, and the blast furnace wind temperature deviation is a deviation between the hot stove temperature measured at the blast furnace vent portion and the wind temperature set value.

Accordingly, the hot stove operation is controlled to change from the three hot stove operating modes to the two hot stove operating modes. However, it is possible to supply high temperature hot air to the blast furnace in the three operation modes of the hot blast furnace, but in the case of the two operation operation modes of the hot blast furnace, the same high temperature hot air is supplied to the blast furnace. In this case, heat loss of the hot stove may occur, and thus the life of the hot stove may be shortened.

Accordingly, the hot blast furnace operation operation mode is performed in the best range in which heat loss of the hot blast furnace is prevented and blast furnace productivity is not adversely affected.

The opening degree of the hot air valve 19a is detected by the detection unit 27. The sensing unit 27 for detecting the opening degree of the hot air valve 19a is a limit switch provided in the hot air pipe. The limit switch senses using a switch to which the contact is switched when the opening degree of the hot air valve 19a reaches a predetermined limit position.

The detection unit 27 detects the hot air back temperature, the hot air dome temperature, and the blast furnace air temperature in addition to the opening degree of the hot air valve 19a.

The sensing unit 27 that detects the hot stove back temperature and the hot stove dome temperature includes a temperature sensor installed at the shell of the hot stove dome, a temperature sensor installed at the edge of the hot stove dome, and a temperature sensor inserted into the outside of the hot stove dome. And, the sensing unit for detecting the blast furnace temperature is a plurality of temperature sensors provided in the blast furnace vents. A thermocouple may be used as the temperature sensor.

The operation of the hot stove two operation mode will be described in detail.

For convenience of description, the two hot stoves normally operated will be referred to as a first hot stove, a second hot stove, and a hot stove to be thermally operated will be referred to as a third hot stove.

When the first hot stove is burned and operated, the second hot stove is blown and the first hot stove and the second hot stove are circulated with each other in the combustion-standby-blowing operation sequence. The case where the first hot stove is burned and the second hot stove is blown is described as an example.

4 shows an example of the first hot stove combustion operation in a flowchart.

As shown in FIG. 4, the hot stove combustion operation includes calculating a combustion heat of the hot stove 10 (S11), measuring a hot stove dome temperature setpoint deviation, and determining whether the hot stove dome temperature setpoint deviation is less than the set point. It includes the step (S12).

The hot stove dome temperature deviation is the deviation between the hot stove temperature and the hot stove dome temperature measured at the hot stove dome.

The hot stove dome temperature setpoint is set in the range of 1380 to 1400 ° C. Hot stove dome temperature is important for combustion and it is advantageous that the temperature is high to obtain sufficient heat, but if it exceeds 1400 ℃, hot gas will heat the stove and cause cracks in the smoke and equipment, shortening the hot stove life.

Temperature measurement of the hot stove dome is carried out by a temperature sensor installed on the shell of the hot stove dome, a temperature sensor installed on the edge of the hot stove dome, and a temperature sensor inserted into the inside of the hot stove dome.

If the determined hot stove dome temperature deviation is less than the set value, the hot stove combustion operation is converted to standby operation.

The set point of the hot stove dome temperature deviation is 100 ° C. If the hot stove dome temperature deviation is less than 100 ° C., it is determined that the hot stove is operating stably and the hot stove combustion operation is converted into the standby operation.

If the hot stove dome temperature deviation is more than 100 ° C, combustion chamber flames are high and the heat loss is high, resulting in unstable operation of the hot stove. Therefore, if the determined hot stove dome temperature set value deviation is equal to or larger than the set value, the combustion heat is recalculated by adjusting the combustion air amount, the COG mixing ratio, and the mixed gas amount (S14), and calculating the hot stove dome temperature set value deviation (S11). Is performed.

The heat of combustion is calculated by the amount of combustion air, the COG mixing ratio, and the amount of mixed gas supplied to the hot stove 10, and the hot stove dome temperature set value deviation according to the combustion heat changes is calculated.

The amount of combustion air is the amount of air supplied for the combustion of the mixed gas, the COG mixing ratio is the coke oven gas (COG) gas mixing ratio, and the mixed gas means a gas in which blast furnace gas (BFG) and coke oven gas (COG) are mixed. do.

And determining whether or not the remaining second hot stove is converted to the combustion operation during which the abnormality does not occur during the standby operation of the hot stove. (S15) As a result of the determination, when the second hot stove is converted to the combustion operation, the first hot standby operation is performed. The hot stove is converted into a blowing operation (S16). The combustion-standby-blowing operation cycle of the first hot stove and the second hot stove is circulated through this.

The second hot stove is blown during the first hot stove combustion operation. 5 is a flowchart showing an embodiment of a second hot stove blowing operation.

As shown in FIG. 5, the hot stove (second hot stove) blowing operation is performed by adjusting the opening degree of the cold wind supply valve (CBMCV) while monitoring the hot stove and the wind temperature (S21), and a hot stove back temperature, And determining whether the hot stove dome temperature set value deviation and the wind temperature set value deviation are less than the set value, respectively (S23).

If the determined hot stove back temperature, hot stove dome temperature setpoint deviation, and wind temperature setpoint deviation are less than the set value, the hot stove blower operation is converted to the combustion operation.

The hot stove back temperature means the hot stove smoke temperature, and the hot stove dome temperature deviation is a deviation between the hot stove temperature measured at the hot stove dome portion and the hot stove dome temperature setpoint, as described above.

The wind temperature is the temperature of the hot wind supplied to the blast furnace, and the wind temperature setpoint deviation is a deviation between the hot wind temperature measured at the blast furnace vent and the wind temperature setpoint.

The air temperature set point is set within a range in which heat loss of the hot stove is prevented based on the hot stove back temperature, the hot stove dome temperature, and the air volume. The hot stove back temperature is used to manage the temperature of the hot stove, and the hot stove dome temperature and the volume of the hot stove combustion heat are managed to manage the heat loss of the final hot stove.

Therefore, the hot air temperature measured in the tuyere part is measured by a plurality of temperature sensors provided in the tuyere part.

The hot stove back temperature set value is 550 ° C, the hot stove dome temperature set value deviation is 100 ° C, and the wind temperature set value deviation is 50 ° C.

The set back temperature of 550 ℃ in the hot stove takes into account the smoke and transformation point. When the back temperature of the hot air furnace is lowered below 550 ° C., the edible falls below the transformation point, causing cracks in the edible and loss of edible function such as heat storage and dissipation prevention.

The set value 100 deg. C of the hot stove dome temperature set value deviation is a set value for stably maintaining the hot stove for the same reason as described above.

The set value 50 ° C. of the wind temperature set value deviation is for stabilization of the blast furnace and improvement of productivity. If the wind temperature set value deviation is 50 ° C or higher, a difference occurs in the amount of heat supplied to the blast furnace, and the combustion temperature of the coke changes so that a deviation of the reducing gas generated during combustion occurs. Deviation of reducing gas causes deviations in the rate of reduction and melting of iron ore, resulting in blast furnace operation performance deviations.

Therefore, if any one of the determined hot stove back temperature, hot stove dome temperature setpoint deviation, and wind temperature setpoint deviation is equal to or greater than the set value, respectively, the blower air volume adjustment is performed (S25) and the hot stove and wind temperature are monitored (S21). Step S22 of adjusting the opening degree of the valve CBMCV is performed again.

The combustion operation of the hot stove (second hot stove) is performed in the same process as the combustion operation method of the hot stove (first hot stove), and the standby operation is performed after the combustion operation (S26). The cycle is repeatedly circulated until the return to normal operation of the hot stove or the blast furnace operation is completed.

When the two hot stove operation modes described above are applied, the hot stove is circulated in a cycle of 50 minutes of combustion, 10 minutes of air, and 60 minutes of air blowing, and a blower air volume control valve 26a (flow rate of cold air flowing into the hot stove) and The flow rate ratio of the cold air supply valve (CBMCV) 25a that supplies the cold air to the mixed cooling chamber is adjusted to 7: 3.

As a result, in this case, the wind temperature of the hot air supplied to the blast furnace is maintained in the range of 950 ~ 970 ℃. In addition, the blast furnace start-up cost is also maintained in the 1.9 range. The blast furnace cost of 1.9 is lower than that of the 3rd blast furnace, but it does not matter when operating the blast furnace, as it exceeds the condition of more than 1.5.

Table 1 below shows the hot blast temperature, the wind temperature, the molten iron temperature compared to the three blast furnace operating mode when the two hot stove operating mode according to the present invention is applied.

division Blast furnace three operation operation mode
(1st to 3rd hot stove
Normal operation) Blast furnace two operation operation mode
(1st and 2nd hot stove normal operation, 3rd hot stove thermal operation) Cycle cycle Combustion 80 minutes, atmosphere 10-13 minutes, ventilation 45 minutes 50 minutes of combustion, 10 minutes of atmosphere, 60 minutes of ventilation Blower air volume:
Cold air supply valve (CBMCV) flow rate Controlled by equal pressure flow valve (CBSV) and cold air supply valve (CBMCV) 7: 3 Wind temperature 1220 ~ 1230 ℃ 950 ~ 970 ℃ Molten iron temperature 1490 ~ 1510 ℃ 1510-1530 Admission fee 2.2 to 2.3 1.9

[Admission fee condition: 1.5 or more]

As shown in Table 1 and FIGS. 6 and 7, it was confirmed that the hot air temperature supplied to the blast furnace 30 is lowered but the molten iron temperature is not affected.

Through this, the hot blast furnace can be stably operated and the blast furnace operation can be kept stable by changing the combustion-atmosphere-blowing operation time of the hot blast furnace and changing the blower air flow rate and the cold wind supply valve flow rate even if the hot blast furnace operation mode is maintained. It can be seen that.

The scope of the present invention is not limited to the embodiments described above, but may be defined by the scope of the claims, and those skilled in the art may make various modifications and alterations within the scope of the claims It is self-evident.

10: Hot stove 11: Heat storage room
13: combustion chamber 15: mixed cooling room
17: Blowing pipe 17a: Blowing valve
19: Hot air pipe 19a: Hot air valve
21a: Equal pressure flow control valve 23a: Flue valve
25a: Cold air supply valve 26a: Blower air flow control valve
27: detection unit 28: judgment
29: control unit 30: blast furnace

Claims (11)

Detecting unit detects the opening degree of the hot air valve during operation of the hot air furnace;
Determining, by the determination unit, the opening degree information of the hot air valve provided from the detection unit to determine whether the hot air path is abnormal;
And if the control unit determines that the hot stove is abnormal, controlling the hot stove operation to change from the three hot stove operating modes to the hot stove two operating modes. . The method according to claim 1,
The hot stove operation operation mode is
A hot stove operation method comprising circulating two hot stoves in which no abnormality occurs, in the sequence of combustion operation-standby operation-blowing operation, and thermally operating the hot stoves having abnormalities. The method according to claim 2,
The hot stove combustion operation
Calculating combustion heat of the hot stove;
Calculating a hot stove dome temperature set value deviation, and determining whether the hot stove dome temperature set value deviation is less than a set value,
And the hot stove combustion operation is converted into a standby operation when the determined hot stove dome temperature deviation is less than the set value. The method according to claim 3,
If the determined hot stove dome temperature setpoint deviation is greater than or equal to the set value, the step of recalculating the heat of combustion through adjustment of the combustion air amount, COG mixing ratio, and mixed gas amount is performed, and calculating the hot stove dome temperature setpoint deviation. How to operate. The method according to claim 3 or 4,
And a set value of the hot stove dome temperature setpoint deviation is 100 ° C. The method according to claim 3,
The hot stove standby operation
Hot stove operation method characterized in that the conversion to the blowing operation when the remaining hot stove is not abnormal. The method according to claim 2,
The hot stove air blowing operation
Adjusting the opening degree of a cold air supply valve (CBMCV) while monitoring the hot air furnace and wind temperature;
And determining whether the hot stove back temperature, the hot stove dome temperature setpoint deviation, and the wind temperature setpoint deviation are less than a set value, respectively.
And converting the hot blast air blowing operation into a combustion operation when the determined hot blast back temperature, the hot blast dome temperature deviation, and the wind temperature set variance are less than the set value, respectively. The method of claim 7,
If any one of the determined hot stove back temperature, hot stove dome temperature setpoint deviation, and wind temperature setpoint deviation is equal to or greater than each set value, the air blower air volume adjustment is performed and the cold wind supply valve (CBMCV) opening degree is adjusted while monitoring the hot stove and wind temperature. Hot stove operation method characterized in that the step is performed again. The method of claim 7,
The hot stove back temperature set value is 550 ° C., the hot stove dome temperature set value deviation is 100 ° C., and the wind temperature set value deviation is 50 ° C. The method according to claim 2,
The hot stove operation operation mode is
A hot-blast furnace operation method characterized by circulating in a cycle of 50 minutes of combustion, 10 minutes of air, and 60 minutes of blowing. The method according to claim 2,
The hot stove air blowing operation
A hot blast furnace operating method characterized in that the ratio of the blower air flow rate and the cold air supply valve (CBMCV) flow rate is adjusted to 7: 3.

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