KR101477385B1 - Method for controlling blow of blast furnace - Google Patents

Abstract

The present invention relates to a blowing control method for a blast furnace, wherein a reference range of air blowing amount and oxygen blowing amount in blowing conditions is set in a hot air supplied into a blast furnace tuyere, and a blowing amount and an oxygen blowing amount are controlled according to the reference range, It is possible to prevent the problems such as secondary deterioration due to the fluctuation of the main operational management indexes when changing the blowing condition according to the time of the year and the future, and to ensure the target productivity by stable blast furnace operation.

Description

[0001] METHOD FOR CONTROLLING BLOW OF BLAST FURNACE [0002]

The present invention relates to a blowing control method for a blast furnace, and more particularly, to a blowing control method for a blast furnace capable of stable blast furnace operation.

Generally, blast furnace is a facility that repeatedly charges cokes and iron ore, fuel, and blows hot air through a tuyere to melt iron ore to produce charcoal.

The blast furnace is supplied with not only pulverized coal but also hot air into the blast furnace, and the flow of gas is controlled.

Related prior art is domestic patent registration No. 0851879 'blast furnace facility' (2008.08.06 registered).

According to an aspect of the present invention, there is provided a method of controlling an air conditioner, comprising the steps of: setting a reference range of a blowing amount and an amount of oxygen enrichment in blowing conditions in a hot air supplied into a blast furnace;

And controlling the air blowing amount and the oxygen enriching amount of the hot air to a reference range of the air blowing amount and the oxygen blowing amount.

According to an aspect of the present invention, there is provided a method of controlling an air conditioner, comprising the steps of: setting a reference range of a blowing amount and an amount of oxygen enrichment in blowing conditions in a hot air supplied into a blast furnace;

And controlling the air blowing amount and the oxygen enriching amount of the hot air to a reference range of the air blowing amount and the oxygen blowing amount.

The present invention has the effect of preventing the generation of problems such as secondary deterioration due to fluctuation of the main operation management indexes when the blowing condition is changed according to the aging of the blast furnace during the blast furnace operation and stably operating the blast furnace.

The present invention has an effect of facilitating production of a target production amount of a charcoal by easily managing the fluctuation of the related operation index according to the change of the blowing condition and preventing the cost increase due to the increase of the amount of the reducing agent.

1 is a block diagram showing a blowing control method for a blast furnace according to the present invention;
2 is a graph showing an example of visualization of a reference range of the blowing amount and the amount of oxygen enrichment in the blast furnace blowing control method according to the present invention
3 is a graph showing another example of visualizing the reference range of the blowing amount and the amount of oxygen enrichment in the blast furnace blowing control method according to the present invention

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

A method for controlling blowing in a blast furnace according to the present invention includes a step (100) of setting a reference range (S) of a blast amount and an oxygen blending amount in a blowing condition in hot air supplied into a blast furnace tuyere, And controlling (200) the blowing amount of the hot air and the oxygen enriching amount in the range (S).

The step (100) of setting the reference range (S) of the amount of blowing air and the amount of oxygen enrichment is a step (110) of deriving a diagram for each operation condition according to the blowing amount and the amount of oxygen enrichment in a plurality of operating conditions; And

A portion overlapping with the blowing amount and the oxygen blowing amount exceeding the blowing amount and the oxygen blowing amount exceeding the blowing amount and the oxygen blowing amount falling within the range where the blowing amount and the oxygen blowing amount are less than the standard blowing amount and the oxygen blowing amount reference (S). ≪ / RTI >

In the step 110 of deriving the operating conditions by operating conditions, it is preferable that the X and Y axes are taken as the amount of blowing air and the amount of oxygen enrichment, and a graph for each operation condition is displayed and displayed so that the operator can confirm it. The graphs indicated by the operating conditions are changed by receiving the respective operating condition data in real time during the blast furnace operation and the reference ranges of the blowing amount and the oxygen enrichment amount set in accordance with the change of the operating conditions (S) is also changed.

In order to control the target production volume of blast furnace during the blast furnace operation, it is necessary to control the oxygen supply to reduce the iron ore to control the planned production target. The control of the oxygen content is controlled by the blowing conditions, and the blowing conditions include the blowing amount, the amount of oxygen enrichment, the amount of conditioning, and the amount of pulverized coal blown. It is preferable that the blowing condition at the time of blast furnace operation is adjusted according to the theoretical combustion temperature, the flooding in the filling layer, and the excess acid consumption (oxygen dose relative to the amount of pulverized coal sprayed). If the conditions of the theoretical burning temperature, the flooding in the filling layer, and the excess acid consumption (oxygen content relative to the amount of pulverized coal injection) are sufficient, that is, if the predetermined range is satisfied, charcoal can be normally produced in the blast furnace , Otherwise the melting capacity of the lower part of the blast furnace is insufficient and the charter can not be produced at the target production amount.

The operating condition is a target production amount, a flooding limitation, a theoretical combustion temperature range, an excess acid consumption, and the above-mentioned line-by-line operating conditions show a target production amount line A, , The theoretical combustion temperature upper limit line (C), the theoretical combustion temperature lower limit line (D), and the excess acid consumption line (E).

The reference range S of the amount of air blowing and the amount of oxygen enrichment satisfies a range where the excess oxygen ratio is equal to or larger than a predetermined excess acid consumption standard value.

The reference range S of the blowing amount and the oxygen enrichment amount satisfies the range between the upper limit and the lower limit of the theoretical burning temperature.

The target production amount diagram (A) is expressed by the following equation (1). The following equations are derived by regression analysis of actual charter production data according to blowing volume, oxygen hatching amount and gas utilization rate during blast furnace operation.

[Equation 1]

Q _s : Target production (ton / day)

X ₁ : Amount blown (Nm ³ / min)

X ₂ : oxygen enrichment amount (Nm ³ / hr)

X ₆ : Gas utilization rate (%)

The discharge (Flooding) restriction leading is represented by Equation 2 below, the reference value is a lower pressure loss a predetermined (C) or less (P _loss C) or less (P _loss ≪ C), while the BHR gas amount (BGV) and the coke porosity are represented by variables.

The predetermined value of the lower pressure loss may be determined according to the size and shape of the blast furnace in the range of 0.2 Kg / Cm ² to 0.5 Kg / Cm ² .

The coke porosity and the coke bottom particle size are values input after sampling at the coke located at the tuff level of the blast furnace during blast furnace operation.

&Quot; (2) "

P _loss (ΔP / L): lower pressure loss (Kg / Cm ² )

BGV: Bosch gas amount (Nm ³ / min)

Y ₁ : Coke porosity

Y ₂ : Coke lower particle size

The Bosch gas amount BGV is calculated by the following equation (3).

&Quot; (3) "

BGV: Bosch gas amount (Nm ³ / min)

X ₁ : Amount blown (Nm ³ / min)

X ₃ : Condition (g / Nm ³ )

R _{X1 / X2} : oxygenated oxygen (Nm 3 / min)

KPC: number of moles of gas produced by pulverizing reaction (mol / g)

PCB: Amount of pulverized coal blown during blowing (g / N㎥)

The BGV is represented by hot wind time + oxygen incubation time + humidity conditioning time + pulverized coal time.

The constant 1.21 is calculated as the increase in volume due to hot air combustion as shown in the following equation. The equation is O ₂ + 2C → 2CO and is calculated as 0.79 + 2 × 0.21.

R _{X1 / X2} is calculated as the volume increase due to oxygenated combustion as shown in the following reaction formula. The equation is O ₂ + 2C → 2CO and is calculated as 2 × O ₂ . 22.4 / 1000 is the unit of correction of L unit in Nm3 unit.

X ₃ is the molecular weight calculated by the following reaction formula.

The reaction is H ₂ O + C → H ₂ + CO.

R _{X1 / X2} , PCB, and KPC are calculated by the following equations (4), (5), and (6).

&Quot; (4) "

R _{X1 / X2} : oxygenated oxygen (Nm 3 / min)

X ₁ : Amount blown (Nm ³ / min)

X ₂ : oxygen enrichment amount (Nm ³ / hr)

The oxygen enrichment amount is an oxygen volume included in the blowing amount. As the amount of oxygen increases, the temperature of the bedside rises and the massive area decreases.

&Quot; (5) "

PCB: Amount of pulverized coal blown during blowing (g / N㎥)

X ₁ : Amount blown (Nm ³ / min)

X ₄ : Amount of pulverized coal blown (ton / hr)

&Quot; (6) "

Equation (6) is an equation for calculating an elemental value according to the use of pulverized coal, where H 2 O _PC is the pulverized coal moisture content, H _PC is the hydrogen contained in the pulverized coal moisture, N _PC is the nitrogen included in the blowing air, O _PC is the volume increased by oxygen combustion in pulverized coal.

Meanwhile, the theoretical burning temperature upper limit line (C) and the theoretical burning temperature lower limit line (D) are calculated by the following equation (7), and the reference range S of the blowing amount and the oxygen enrichment amount is calculated from the theoretical burning temperature The upper limit reference value T ₁ and the lower limit reference value T ₂ of T _f . That is, the theoretical combustion temperature upper limit line (C) is derived as the upper limit reference value (T ₁ ), and the theoretical combustion temperature lower limit line (D) is derived as the lower limit reference value (T ₂ ). In the present invention, the upper limit reference value T ₁ is 2250 ° C and the lower limit reference value T ₂ is 2150 ° C. That is, in the present invention, the theoretical combustion temperature T _f satisfies the range of 2150 ° C <T _f <2250 ° C.

&Quot; (7) &quot;

T _f : Theoretical combustion temperature (캜)

X ₁ : Amount blown (Nm ³ / min)

X ₂ : oxygen enrichment amount (Nm ³ / hr)

X ₃ : Condition (g / Nm ³ )

X ₄ : Amount of pulverized coal blown (ton / hr)

X ₅ : blowing temperature (캜)

On the other hand, consume the excess acid leading to (E) is a mathematical is calculated by the expression (8), said blowing air volume and the reference range (S) is a (μ _s) the excess acid consumption (μ) the excess acid consumption reference values of the oxygen-enriched amount of the to At least equal to or greater than the range. In the present invention, the excessive acid consumption standard value (μ _s ) is 0.7. That is, in the present invention, the excessive acid consumption standard value (μ _s ) satisfies a range of 0.7 <μ _s .

&Quot; (8) &quot;

μ: excess acid consumption

X ₁ : Amount blown (Nm ³ / min)

X ₂ : oxygen enrichment amount (Nm ³ / hr)

X ₄ : Amount of pulverized coal blown (ton / hr)

On the other hand, FIG. 2 confirms that the ranges of the blowing amount and the oxygen blowing amount are overlapped with each other in the range where the blowing amount and the oxygen blowing amount are smaller than the blowing amount and the oxygen blowing amount based on the respective operating condition diagrams.

The graphs indicated by the operating conditions are changed by receiving the respective operating condition data in real time during the blast furnace operation and the reference ranges of the blowing amount and the oxygen enrichment amount set in accordance with the change of the operating conditions (S) is also changed so that the operator can check the change of the reference range of the blowing amount and the amount of oxygen enrichment in real time, thereby controlling the blowing amount of the hot air supplied into the blast furnace and the amount of oxygen enrichment.

The present invention may further include the step of displaying the blowing amount of the hot air supplied into the blast furnace and the value P of the oxygen enrichment amount in the above graph.

The present invention adjusts the blowing amount of the hot air supplied into the blast furnace and the oxygen enriching amount to within the reference range S of the blowing amount and the oxygen enriching amount and the blowing amount and the oxygen enriching amount of the hot air supplied into the blast furnace It may further include a step of informing the user when the out of the range S is reached.

The present invention prevents the occurrence of problems such as secondary deterioration due to fluctuation of the main operational management indexes when the blowing condition is changed according to the aging of the blast furnace during the blast furnace operation, and enables stable blast furnace operation.

The present invention easily manages the fluctuation of the related operation index according to the change of the blowing condition to smoothly produce the target production amount of the charcoal and prevents the cost increase due to the increase of the amount of the reducing agent.

It will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the present invention.

100: step of setting reference range
200: controlling the blowing amount and the amount of oxygen enrichment

Claims (7)

delete Setting a reference range of the blowing amount and the amount of oxygen enrichment in blowing conditions in the hot air supplied into the furnace tuyere;
And controlling the blowing amount of the hot air and the oxygen enriching amount in a reference range of the blowing amount and the oxygen enriching amount,
Wherein the step of setting the reference range of the amount of blowing air and the amount of oxygen enrichment includes the steps of deriving a diagram for each operating condition according to the blowing amount and the amount of oxygen enrichment in a plurality of operating conditions; And
Wherein the step of setting the air blowing amount and the oxygen enriching amount as a reference range of the air blowing amount and the oxygen enriching amount overlap each other in a range where the air blowing amount and the oxygen enriching amount are exceeded, Control method. The method of claim 2,
Wherein the step of deriving the line-by-line operating conditions comprises the steps of plotting the X-axis and Y-axis as the amount of blowing air and the amount of oxygen enrichment, respectively, and displaying a graph for each operating condition and outputting it as a graph. The method of claim 3,
Further comprising the step of displaying the blowing amount of the hot air and the oxygen annealing amount supplied into the blast furnace in the above graph. The method of claim 2,
Wherein the operating condition is a target production amount, a flooding limit, a theoretical combustion temperature range, and an excess acid consumption, and the above-mentioned line-by-line operating conditions include a target production amount curve based on the blowing amount and the oxygen enrichment amount, Wherein the combustion temperature is lower than the theoretical combustion temperature lower limit, and the excess acid consumption is higher than the theoretical combustion temperature lower limit. The method of claim 5,
Wherein the reference range of the amount of blowing air and the amount of oxygen enrichment satisfies a range where the excess oxygen ratio is equal to or larger than a predetermined excess acid consumption reference value. The method of claim 5,
Wherein the reference range of the amount of blowing air and the amount of oxygen enrichment satisfies a range between an upper limit and a lower limit of the theoretical burning temperature.

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