KR20110046673A - Method of detecting gas stream of upper part of blast furnace using heat emission index - Google Patents

Abstract

PURPOSE: A method for detecting gas stream on an upper part of a blast furnace using heat emission index is provided to prevent failure state of a furnace by an estimation equation which can calculate heat emission index on a central area, a middle area, and a peripheral area. CONSTITUTION: A method for detecting gas stream on an upper part of a blast furnace using heat emission index comprises following steps. Based on the center of a blast furnace, the top of the furnace is classified into a central area, a middle area, and a peripheral area, and temperature measuring units are installed on each area so the temperature of each area is detected from temperature data generated by the temperature measuring unit. Heat emission indexes on a central area, a middle area, and a peripheral area are calculated based on area ration of each area. Based on the heat emission indexes, the state of the furnace is determined.

Description

Method of detecting gas stream of upper part of blast furnace using heat emission index}

The present invention relates to a gas flow detection method of the upper part of the blast furnace using a heat release index, and more specifically, to estimate the gas flow in the furnace by using the temperature of the above-described temperature measuring instrument (Above Burden Probe), The present invention relates to a gas flow detection method of a blast furnace upper part using a heat release index which can maintain a stable rust state by providing an operator with numerical data so as to maintain a core coke state in good condition.

In general, the operation of blast furnaces can be economically operated only when the ventilation and liquidity of the lower part of the blast furnace is maintained, thereby increasing the yield and extending the life of the blast furnace. To this end, the heat exchange and the chemical reaction between the charge and the gas from the hearth should be performed smoothly, but the core state from the hearth down to the bottom can be stably maintained.

Therefore, the distribution of gas in the radial direction of the blast furnace must be constant for stable blast furnace operation, and the management of gas distribution in the blast furnace is important to induce a high-efficiency reduction reaction. The gas distribution pattern should be controlled according to the operation situation through control and blow control.

However, even if problems such as unstable aging and fluctuation of the molten iron quality due to impaired fluidity of the bottom of the blast furnace, it is difficult to quantitatively detect this. In determining the gas flow distribution pattern inside the blast furnace, as a method of detecting a change in the gas flow passing through the inside of the high temperature blast furnace, the Republic of Korea Patent No. 10-0776036 divides the inside of the blast furnace into three regions, the periphery, the middle, and the center. Although the method of detecting core changes is introduced, this method is only an empirical formula based on POSCO's Gwangyang 3 and 4 blast furnaces. When managing the aging with the central flow index alone, blast furnace conditions can only be evaluated one-dimensionally, which is not a fundamental solution.

Therefore, it is necessary to derive a new control method to solve the melt discharge defect of the lower part of the furnace and the difference in the molten iron temperature difference by the exit port, and to secure the good fluidity of the lower part of the furnace, and to judge the change of the blast furnace at the top of the blast furnace. There is a need for a control scheme.

The present invention is to solve the conventional problems as described above, to estimate the gas flow in the furnace by using the temperature of the above-mentioned blast furnace temperature probe (Above Burden Probe), the lower core coke state in a good state It is an object of the present invention to provide a gas flow detection method on the top of a blast furnace using a heat release index that can maintain a stable aging state by providing a numerical data to an operator to maintain the operation pattern management.

Gas flow detection method of the upper part of the blast furnace using the heat release index according to the present invention for achieving the above object, the upper part of the blast furnace based on the center of the blast furnace divided into a central region, an intermediate region and a peripheral region, each area Installing corresponding temperature measuring instruments to detect the temperature of each region from the temperature data obtained from the temperature measuring instruments, the temperature data detected from detecting the temperature of each region, and the overall cross-sectional area of the upper part of the blast furnace from the center, etc. On the basis of the area ratio of each area to the area separated by the interval, by the heat release index calculated in the step of calculating the heat release index in the center region, the middle region and the peripheral region and calculating the heat release index Determining a change in yellowing.

In addition, the heat release index in the center region, the middle region, and the peripheral region may be calculated by the following Equations 1 to 3 below.

&Quot; (1) "

<Equation 2>

&Quot; (3) &quot;

In Equations 1 to 3, the _center of H is the heat release index (%) in the center region, the _middle H is the heat release index (%) in the middle region, and the area _around H is the heat release index (%). ), X _i is the ratio of the area of each area to the area divided into six equal intervals from the center of the entire blast furnace (X ₁ = 11P, X ₂ = 9P, X ₃ = 7P, X ₄ = 5P, X ₅ = 3P, X ₆ = 1P), Y ₁ and Y ₂ are the average temperatures measured from the thermometers installed in the X1 and X2 zones, and Y ₃ and Y ₄ are measured from the thermometers respectively installed in the X3 and X4 zones. Average temperatures, Y ₅ and Y _6, are mean temperatures measured from thermometers installed in the X5 and X6 zones, respectively.

The temperature measuring devices may be installed in a radial direction toward the center of the blast furnace, and the temperature measuring devices may be spaced apart from each other at an angle of 90 °.

The temperature measuring device may include a first temperature measuring device having a plurality of thermometers mounted at equal intervals from a center of the blast furnace to a position corresponding to the inner wall of the blast furnace, and on the inner wall of the blast furnace at a predetermined distance from the center of the blast furnace. A plurality of thermometers may be configured as second, third and fourth temperature measuring instruments mounted at equal intervals up to a corresponding position.

According to the gas flow detection method of the upper part of the blast furnace using the heat release index according to the present invention, the temperature data detected from a plurality of thermometers mounted at equal intervals in each of the temperature measuring devices installed on the top of the blast furnace charge and the total cross-sectional area of the upper part of the blast furnace Based on the area ratio of each area from the center to the equally spaced area, a formula for calculating the heat release index in the center area, the middle area and the surrounding area is derived so that appropriate operation pattern management actions can be taken. There is an advantage that does not reach a large yellowing failure state by the core inert.

In addition, the gas flow detection method in the upper part of the blast furnace using the heat release index according to the present invention can be commonly applied to general blast furnaces, not specific blast furnaces, and the heat release index is shown in three-axis regions so that the gas flow pattern can be seen at each eye. There is an advantage that can be easily grasped to determine the state of the blast furnace.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a cross-sectional view showing the interior of the blast furnace according to an embodiment of the present invention, Figure 2 is a position diagram showing a state in which the upper portion of the blast furnace divided into a central region, an intermediate region and a peripheral region according to the present invention.

During operation of the blast furnace, the iron ore and coke is charged into the blast furnace 100, and hot blast of hot air is injected through the tuyere 10 under the blast furnace to induce a reduction melting reaction in the blast furnace 100. The molten iron and slag are produced using the high temperature reduction melting reaction.

Referring to FIG. 2, an area from the center of the blast furnace having an upper radius of 5.55 m to a radius of 1.85 m is located in the center area (X5, X6), and an area from the outside of the center area to a radius of 3.70 m in the middle area (X3, X4), The area from the outside of the middle area to a radius of 5.55m, that is, to the blast furnace inner wall, is divided into the peripheral areas X1 and X2.

Figure 3 is a plan view showing a state in which a thermometer is equipped with a thermometer (Above Burden Probe) is installed on top of the blast furnace according to the present invention.

Each temperature measuring unit (51, 52, 53, 54) is installed in a radial direction toward the center of the blast furnace, each temperature measuring unit is disposed spaced at an angle of 90 degrees to each other, in Figure 3 60 °, 150 °, 240 An embodiment in which the temperature measuring devices 51, 52, 53, and 54 are installed at positions ˚ and 330 ˚ is illustrated.

Seven thermometers are mounted on the first temperature measuring unit 51 installed in the 60 ° direction, and each thermometer is located at the center of the blast furnace and at a position spaced 0.925 m, 1.85 m, 2.77 m, 3.695 m, and 4.62 m from the center of the blast furnace. It is mounted at equal intervals at the corresponding positions (5.55m), respectively.

Six thermometers are mounted on the second temperature measuring unit 52, the third temperature measuring unit 53, and the fourth temperature measuring unit 54 respectively installed in the directions of 150 °, 240 °, and 330 °, respectively. They are equidistantly mounted at positions equal to 0.925m, 1.85m, 2.77m, 3.695m and 4.62m from the center of the blast furnace and at positions corresponding to the blast furnace inner wall (5.55m), respectively.

Therefore, two thermometers for each temperature measuring instrument correspond to the center region, the middle region and the peripheral region of the blast furnace, so that two kinds of temperature data can be obtained in each region.

On the other hand, looking at the area ratio when viewed from the top of the blast furnace, since the area of each area is different from each other, the area correction value is applied to each of the temperature data for correction. Since the center of the blast furnace is divided into the center area X6, X5, the middle area X4, X3, the peripheral area X2, and X1, and have different radii, the area is corrected in proportion to the area X6 which is the area with the smallest radius. .

The area for each area to which the correction value for the area is applied is obtained as follows.

The area of the X6 region = π (0.8) ² = 0.64π, which is called "P" for convenience. The area of the X5 area = π (1.6) ² -π (0.8) ² = 1.92π, and the area of X5 is "3P". If the area ratio of the other areas is obtained in this manner, the area of the X4 area is "5P", X3. The area of the area is "7P", the area of the X2 area is "9P", and the area of the area X1 is "11P".

In the present invention, six thermometers are equipped with a temperature measuring device in the position of 60 °, 150 °, 240 °, 330 ° in the radial direction toward the center on the top of the blast furnace, respectively, but the present invention is not limited to this, more precise temperature data It is also possible to further refine the area of the blast furnace to obtain a more accurate temperature data by mounting more thermometers.

In the present invention, each of the six temperature data in the temperature measuring devices (51, 52, 53, 54) installed in the four directions of 60 °, 150 °, 240 °, 330 ° top of the blast furnace charge and temperature data of different areas The equations for obtaining the heat release index for each area were derived as follows using the correction values for different areas of each area.

In Equation 1, the _center of H is the heat release index (%) in the center region, and X _i is the area of each region with respect to the area divided into six equal intervals from the center as a whole. As a ratio, specifically, when the area of the X6 region is P, X ₁ is 11P, which is the area ratio of the X1 region to the area of the X6 region, and X ₂ is 9P, which is the area ratio of the X2 region to the area of the X6 region. In this manner, X ₃ = 7P, X ₄ = 5P, X ₅ = 3P, and X ₆ = 1P.

Here, Y ₅ and Y ₆ mean the average temperature measured from the thermometer installed in the X5 region and the X6 region, respectively.

That is, referring to FIG. 3, there are thermometers of the first to fourth temperature measuring instruments in different directions in region X5, and Y ₅ is an average value of four temperatures measured by the thermometers of the first to fourth temperature measuring instruments. Likewise Y ₆ is the average of the four temperatures measured on the thermometers of the first to fourth thermometers in different directions in the region X6.

 As in the central region, the heat release index in the intermediate region and the peripheral region is calculated as follows.

Here, H _intermediate is heat release index (%) in the intermediate region, _{the peripheral} H refers to the heat release index (%) in the peripheral region, Y _1, Y _2, Y _3, Y ₄ are X1, X2, respectively, and It is the average value of four temperatures measured by the thermometer of the 1st-4th temperature measuring device of a different direction in X3, X4 area | region.

Referring to the derivation process of Equations 1 to 3 as described above are as follows.

The following formula (1) is known as a general calorie formula.

Q = m × c × T ------- Equation (1)

Q is a calorie (cal), in the present invention means the heat of the gas. c means the specific heat of the gas (cal / g ° C), m is the mass of the gas (g), T means the temperature of the gas (℃). In the above formula, the mass m can be reduced to a value relating to V (volume), which is the same as the following formula (2).

Q = m × c × T = k × V × T ------- Equation (2)

Where k is the new coefficient, V is the volume of the moving gas, and T is the temperature of the gas. Since V can be expressed as the product of the cross-sectional area and the flow rate, the above formula (2) can be reduced to the following formula (3).

Q = k × V × T = k × A × v × T ------- Equation (3)

Here, A is the cross-sectional area of the gas to move, v means the flow rate of the gas. Here, since the flow velocity of gas (v) has a relation proportional to the temperature (T), substituting this into equation (3),

Q = k × A × v × T = f × A × T ² ------- Equation (4)

Where f is a newly calculated coefficient.

From the above formula (4), it can be seen that the heat amount Q is proportional to the cross-sectional area A and the square of the temperature T ² .

That is, the equations (1) to (3) represent the ratio of the amount of heat released in each region, and the amount of heat emitted in each region is proportional to X _i , which means the cross-sectional area, and is the square of Y _i , which means temperature. It can be expressed proportionally.

In Equations 1 to 3, the denominator represents the total amount of heat emitted from the center region, the middle region, and the peripheral region, and the molecule represents the amount of heat released from each region, and multiplyed by 100 to convert the percentage. In the present invention, it was defined as the heat release index.

By calculating the heat release index in each region according to Equations 1 to 3, it is possible to compare the gas flow in each region with the gas flow in another region.

That is, Equation 1 is for determining how much the gas flow (center flow) in the center region is activated than the gas flow in the other region. Equation 3 is to determine how much more active the gas flow (peripheral flow) of the peripheral area than the gas flow of the other area.

Accordingly, it can be seen that when the heat release index in the central region derived by Equation 1 is high, the central flow in the central region is activated more than other regions.

When the environment inside the blast furnace is stable, the temperature of the central region is high, and when the environment of the blast furnace is deteriorated, the temperature of the center region is lowered. When the heat release index is high in the central region, the environment inside the blast furnace is stable. It can be determined that the case.

Therefore, the heat release index is calculated for a predetermined time period using Equation 1 to Equation 3, and the change in aging is determined using the heat release index calculated in each region.

Figure 4 is a graph showing the heat release index calculated for a certain period in the three-axis region in accordance with the present invention.

After calculating the heat release index in each region, the graph of heat release index is made with this result, so that it is easy to grasp the gas flow pattern for each region.

That is, when moving from point A to point B of FIG. 4, it means that the gas flow in the center region (center flow) is reduced and the gas flow in the middle region (medium flow) is increased. Poor and unstable core conditions can identify trends in gas flow midstream due to poor ventilation at the core.

Similarly, when moving from point C of FIG. 4 to point A, it means that the gas flow in the center region (center flow) is increased and the gas flow in the middle region (medium flow) is decreased, thereby making the blast furnace operation stable. It can be concluded that it remains and that the core state is stabilizing.

In this way, the operator can determine the change in the yellowing by calculating and graphing the heat release index in each area, there is an advantage that can prevent the blast furnace accident damage in advance by performing the operation pattern management accordingly.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1 is a cross-sectional view showing the interior of the blast furnace according to an embodiment of the present invention,

2 is a position view showing a state in which the upper portion of the blast furnace divided into a central region, an intermediate region and a peripheral region according to the present invention;

3 is a plan view showing a state in which a thermometer equipped with a thermometer (Above Burden Probe) is installed on top of the blast furnace according to the present invention,

Figure 4 is a graph showing the heat release index calculated for a certain period in the three-axis region in accordance with the present invention.

Claims (6)

Dividing the upper part of the blast furnace into a central region, an intermediate region and a peripheral region based on the center of the blast furnace, and installing temperature measuring instruments corresponding to each region to detect temperature of each region from the temperature data obtained from the temperature measuring instruments ; In the center region, the middle region and the peripheral region, based on the temperature data detected from the step of detecting the temperature of each region and the area ratio of each region with respect to the region where the entire cross-sectional area of the upper part of the blast furnace is divided into equal intervals from the center. Calculating a heat release index of; And Determining the change in the sulfur by the heat release index calculated in the step of calculating the heat release index gas detection method using the heat release index inside the blast furnace. The method according to claim 1, The heat release index in the central region is a gas flow detection method in the blast furnace using a heat release index, characterized in that calculated by the following equation (1). &Quot; (1) &quot;

[Equation 1, H _center is the heat release index (%) in the center area, X _i is the area ratio of each area to the area divided into six equal intervals from the center of the entire cross-sectional area of the blast furnace (X ₁ = 11P, X ₂ = 9P, X ₃ = 7P, X ₄ = 5P, X ₅ = 3P, X ₆ = 1P), Y ₅ and Y ₆ are the average measured from a thermometer installed in the center area (X5, X6) Means temperature] The method according to claim 1, The heat release index in the intermediate region is a gas flow detection method in the blast furnace using a heat release index, characterized in that calculated by the following equation (2). <Equation 2>

In Equation 2, H _middle is the heat release index (%) in the middle region, X _i is the ratio of the area of each area to the area divided into six equal intervals from the center of the entire cross-sectional area of the blast furnace (X ₁ = 11P, X ₂ = 9P, X ₃ = 7P, X ₄ = 5P, X ₅ = 3P, X ₆ = 1P), Y ₃ and Y ₄ are measured by a thermometer installed in the intermediate region (X3, X4), respectively. Mean temperature] The method according to claim 1, The heat release index in the peripheral region is a gas flow detection method in the blast furnace using a heat release index, characterized in that calculated by the following equation (3). &Quot; (3) &quot;

[Equation 3, the H _around the heat release index (%) in the peripheral area, X _i is the area ratio of each area to the area divided into six equal intervals from the center of the overall cross-sectional area of the blast furnace (X ₁ = 11P, X ₂ = 9P, X ₃ = 7P, X ₄ = 5P, X ₅ = 3P, X ₆ = 1P), Y ₁ and Y ₂ measured from a thermometer installed in the peripheral area (X1, X2), respectively Mean temperature] The method according to claim 1, The temperature measuring instruments are installed in a radial direction toward the center of the blast furnace, The temperature measuring method of the gas flow inside the blast furnace using the heat release index, characterized in that the temperature measuring unit is arranged to be spaced apart from each other at an angle of 90 °. The method according to claim 5, The temperature measuring instruments, A first temperature measuring instrument having a plurality of thermometers mounted at equal intervals from a center of the blast furnace to a position corresponding to the blast furnace inner wall, Using a heat release index, characterized in that composed of a plurality of thermometers are mounted at equal intervals from the center of the blast furnace to a position corresponding to the inner wall of the blast furnace at regular intervals Gas flow detection method in blast furnace.

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