JP2003013118A - Method of controlling lower part of blast furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of controlling the lower part of blast furnace, which can stabilize the operation of a blast furnace, by using the readings of a pyrometer which is buried in a refractory to exclude disturbance on the cooling side of the pyrometer, precisely grasping the heat transfer amount in the furnace, and operating the blast furnace according to the conditions presumed from the heat transfer amount in the furnace. SOLUTION: This method comprises burying two or more pyrometers M1 and M2 perpendicularly into the refractories 14 and 16 in the lower part 12 of the blast furnace 11, grasping the progression of actual temperature based on a pair of measured values with pyrometers M1 and M2 , calculating the unsteady heat transfer amount while assuming the heat transfer amount in the furnace toward the operating side and the heat removal amount on the cooling side on the basis of the temperature of the molten pig iron, and determining simultaneously the heat transfer amount inside the furnace and the heat removal amount on the cooling side, by calculating the above obtained progression values so as to substantially match with the actual progression values measured with the pyrometers M1 and M2 , by a heat-transfer reverse analysis method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the lower part of a blast furnace, which accurately predicts the heat load in the lower part of the blast furnace, prevents wear of refractory material on the bottom and side walls of the blast furnace, and prolongs its life. .

[0002]

2. Description of the Related Art Conventionally, it has been considered that molten iron is accumulated in the lower part of the blast furnace, which is composed of the bottom of the blast furnace and the side wall near the bottom of the blast furnace, and a bed of coke is immersed in the molten pig iron. In addition, the hot metal flow (hot metal flow) is formed by the movement of the tapping layer and the coke packed layer.
In this hot metal flow, a large local flow may occur on the inner side of the side wall, and the local flow increases the heat load on the refractory material forming the side wall portion, and the refractory material is worn. If the wear of the refractory material progresses extremely, a furnace wall damage accident occurs, and the operation becomes impossible. On the other hand, in the bottom of the furnace, the coke packed bed may come into contact with the bottom of the furnace or the coke packing density may become high. In this case, the heat load at the center of the bottom is reduced, but near the outer circumference of the bottom. At this point, a large hot metal flow locally occurs, and the heat load on the refractory increases, causing the refractory to wear. In either case, stable operation and long life of the blast furnace cannot be achieved. In order to manage the wear state of the refractory on the bottom and side walls, the heat load state of each refractory is managed by observing the measured temperature with multiple thermometers embedded in the refractory. ing. However, since the thickness of the refractory material is 1.5 m or more, there is a large time delay in grasping the state of the working surface of the refractory material on the furnace bottom and side walls, and external disturbances and the like due to cooling conditions occur. There is a problem that the action of the operation for the measured temperature cannot be performed in real time. As measures against this, Japanese Patent Laid-Open No. 9-6760
As described in Japanese Patent Publication No. 7, a plurality of heat flow meters are arranged on the inside of the refractory and the outer surface of the refractory at the bottom of the furnace, and the measured values of the heat flow meter (thermometer) are used. Method, boundary element method, or finite difference method is used to perform a three-dimensional heat transfer analysis to find the erosion shape of the refractory at the bottom of the furnace, and compare this erosion shape with the largest erosion shape in the past. The advanced surface shape is updated, and three-dimensional heat transfer analysis is performed using the finite element method, boundary element method, or finite difference method based on the heat flow rate from the thermometer value of the furnace bottom described above. , A method of estimating the erosion shape of the refractory material at the bottom of the furnace and the shape of the solidified layer to prevent the refractory material of the blast furnace from being worn and extending the life.

[0003]

However, in the method described in Japanese Patent Laid-Open No. 9-67607, the bottom of the blast furnace is assumed to be in a simulated thermal steady state, and the temperature inside the furnace is suddenly increased. It is not possible to use the erosion shape of the furnace bottom refractory and the shape of the solidified layer, which are estimated by calculation, for the action during unsteady state, because the application to the actual operation with high unsteadyness that changes to 1 is not considered. For example, based on the erosion shape of the refractory and the shape of the solidified layer, etc., when carrying out operation actions such as blowing conditions into the furnace, restrictions on tap hole, etc., the action of the operation is the originally desirable operation action. Invites when different from. As a result, the eroded shape and the shape of the solidified layer are further deteriorated. Furthermore, in actual operation,
Since the condition on the cooling side (outside the furnace) according to the heat load measured by the thermometer is not considered, it becomes a disturbance factor of the erosion shape of the furnace bottom refractory and the shape of the solidified layer estimated by calculation, and erosion The shape, the shape of the solidified layer, etc. become inaccurate, and proper operation actions cannot be performed. Moreover, if the operation actions such as the conditions for blowing air into the furnace and restrictions on the tap hole become inaccurate, the progress of erosion of the refractory at the bottom of the furnace and the shape of the solidified layer will worsen, and the operation of the blast furnace will become unstable. However, there is a problem such as a decrease in the amount of tapped metal.

The present invention has been made in view of the above circumstances, and accurately measures the amount of heat transfer in the furnace by using a thermometer value that eliminates disturbance on the cooling side of a thermometer embedded in a refractory, It is an object of the present invention to provide a management method for the lower part of a blast furnace that can stabilize the operation of the blast furnace by performing a blast furnace operation action according to the in-furnace condition estimated from the internal heat transfer amount.

[0005]

According to the method for controlling the lower part of a blast furnace of the present invention which meets the above-mentioned object, two or more thermometers are embedded in the refractory at the lower part of the blast furnace in the thickness direction, and the thermometer is used. Grasping the actual temperature transition with the measured temperature as a pair, performing unsteady heat transfer calculation assuming the heat transfer amount in the furnace and the heat removal amount on the cooling side from the hot metal temperature at this time, and obtain the calculated temperature. The heat transfer inverse analysis method is used for calculation so that the transition value of the temperature of the meter substantially matches the temperature actually measured by the thermometer, and the heat transfer amount in the furnace and the heat removal amount on the cooling side are simultaneously determined. The in-furnace heat transfer amount is the in-reactor heat transfer coefficient Up from the operating surface part, or
It is a heat transmission flow rate qp from the operating surface portion, and the cooling side heat transfer coefficient Uw or the cooling side heat transmission flow rate qw can be used as the cooling side heat removal amount. By this method, the heat transfer inverse analysis method is used so that the heat transfer coefficient Up is the amount of heat transfer in the furnace to the operating surface, or the heat transmission flow rate qp to the operating surface side is almost equal to the measured value of the thermometer. Therefore, it is possible to accurately grasp the heat load state of the refractory on the bottom and side walls of the furnace at unsteady times when the temperature changes abruptly, the supply fuel, the cooling conditions on the outside of the bottom,
Operational actions such as branch pipe ventilation and use of tap holes can be properly performed, and the operation of the blast furnace can be stabilized.

Here, the refractory material in the lower part of the furnace is divided into a plurality of calculation meshes, and the innermost mesh is a solidified layer (solidified material) having a melting point at a predetermined temperature, and the space between the surface of the solidified layer and the hot metal is defined. The heat transfer amount and heat balance in the furnace were calculated assuming the heat transfer coefficient of
It is preferable to use the latent heat of solidification and melting of the solidification layer to determine the thickness of the solidification layer at which the surface of the solidification layer has the melting point temperature. This allows
Since the thickness of the solidified layer is calculated using the latent heat of solidification and fusion from the amount of heat transfer in the furnace obtained by dividing into a plurality of calculation meshes, the thickness of the solidified layer formed in the lower part of the furnace can be accurately grasped.

Further, the lower part of the furnace is preferably a bottom or a side wall of the furnace. As a result, it is possible to manage the heat balance of a portion where the heat load of the blast furnace is large and the melting loss of the refractory is severe, and it is possible to accurately grasp the melting loss of the refractory and the state of the solidified layer.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Next, referring to the attached drawings, an embodiment in which the present invention is embodied will be described to provide an understanding of the present invention. FIG. 1 is a cross-sectional view of a measuring apparatus applied to a method for managing a lower part of a blast furnace according to an embodiment of the present invention,
Fig. 2 is a schematic diagram of the measurement site of the heat transfer coefficient in the lower part of the blast furnace, Fig. 3 is a graph showing the relationship between the elapsed days and the temperature of the bottom refractory of the blast furnace, and Fig. 4 is the elapsed days of the bottom refractory and the furnace. Fig. 5 is a graph showing the relationship between the internal heat transfer coefficient, Fig. 5 is a graph showing the relationship between the elapsed days of the furnace bottom refractory and the solidified layer thickness, and Fig. 6 is a graph showing the relationship between the elapsed days of the furnace bottom refractory and the bottom plate cooling action. 7 is a graph showing the relationship between the elapsed days and the temperature of the bottom refractory, FIG. 8 is a graph showing the relationship between the elapsed days of the bottom refractory and the heat transfer coefficient in the furnace, and FIG. 9 is the elapsed days of the bottom refractory. And the cooling heat transfer coefficient, FIG. 10 is a graph showing the relationship between the elapsed days of the furnace bottom refractory and the solidified layer thickness, and FIG. 11 is the relationship between the elapsed days of the furnace bottom refractory and the sidewall refractory remaining thickness. FIG. 12 is a graph showing the relationship between the elapsed days and the operating surface temperature of the furnace bottom refractory. As shown in FIG. 1, the measuring apparatus 10 used in the method for controlling the lower part of a blast furnace according to an embodiment of the present invention is
Side wall 13 made of iron skin that constitutes the lower part 12 of the blast furnace 11.
The side wall refractory 14 lined on the side wall 13, the bottom plate 15 constituting the furnace bottom, and the furnace bottom refractory 16 lined on the bottom plate 15. The furnace bottom refractory 16, a thermometer M ₁ and M ₂ is embedded, the temperature of the M _1, M ₂ is measured and input to the computer (not shown). Further, a cooling water supply pipe 17 is arranged inside the bottom plate 15, and is provided with a cooling water supply valve 18 and a cooling water drain valve 19.
Further, on the surface of the furnace bottom refractory 16, a general solidified layer 20
Is formed, and a pooled portion of the hot metal 21 in which iron oxide is reduced and dissolved is formed on the solidified layer 20.

Next, a blast furnace according to an embodiment of the present invention
Regarding the management method of the lower part, heat transfer in the furnace using the measuring device 10
As a quantity, the heat transfer coefficient Up in the furnace is used as a heat removal amount on the cooling side.
A case of obtaining the side heat transfer coefficient Uw will be described. Blast furnace 1
The thickness direction of this furnace bottom refractory 16
Thermometer M with a certain distance in the direction₁ And M₂ Buried in the furnace
The temperature of the bottom refractory 16 in the thickness direction of 2.5 m
Measure each. This thermometer M₁ And M₂ Accumulates in the furnace
Since the temperature of the hot metal 21 is about 1500 ° C., the solidified layer 20
Transfer of heat transmitted from above and below the furnace bottom refractory 16
Of the heat transfer coefficient of the cooling water supplied to the supply pipe 17
A predetermined temperature is measured and displayed due to the sound. This heat
As shown in FIG. 2, the transmissivity is measured by the internal bottom 15 of the blast furnace 11.
T in the thickness direction of the fired furnace bottom refractory 16₃ ~ T₇ To 5
Divide and further remove heat by cooling water supply pipe 17 of bottom plate 15.
Temperature of the bottom plate 15_W And solidified layer 20 and furnace bottom refractory
16 boundary temperature T₂ , Boundary temperature between the hot metal 21 and the solidified layer 20
Degree T₁ And the temperature T of the hot metal 21_P About each biography
Heat area A₁ ~ A₇ (M² ), Thickness L₁ ~ L₇ (M), dense
Degree ρ ₁ ~ Ρ₇ (Kg / m³ ), Specific heat C₁ ~ C₇ (Kca
1 / kg ° C), thermal conductivity λ₁~ Λ₆ (Kcal / mh
℃) can be determined from its physical properties, profile, etc.
Therefore, the thermometer M for measurement embedded in the furnace bottom refractory 16
₁ And thermometer M₂ Generally used from the measured temperature value of
The heat transfer of each part is calculated by the following equation, which is a one-dimensional unsteady heat transfer calculation.
Find the achievement rate.

For example, T _{3 to} T ₆ are the following (1),
ΔT _i is calculated from the equation (2). ΔQ _i = [A _i × λ _i-1 / L _i-1 × (T _i-1 −T _i ) + A _{i + 1} × λ _i / L _i × (T _{i + 1} −T _i )] × Δt (1) ΔT _i = ΔQ _i / (A _i × L _i × ρ _i × C _i ) (2) Calculate T ₇ using the past performance Uw. ΔQ ₇ = [A ₇ × λ ₆ / L ₆ × (T ₆ −T ₇ ) + A ₈ × Uw × (T _W −T ₇ )] × Δt (3) ΔT ₇ = ΔQ ₇ / ( A ₇ × L ₇ × ρ ₇ × C ₇ ) (4) Using the past results Up, the solidification layer thickness L ₁ or the surface temperature T ₁ is calculated. ΔQ ₁ = [A ₁ × Up × (Tp−T ₁ ) + A ₂ × λ ₁ / L ₁ × (T ₂ −T ₁ )] × Δt (5) However, the solidified layer 20 exists If this is the case, the following formula applies. ΔL ₁ = ΔQ ₁ / Hg / A ₁ (6) When the solidified layer 20 does not exist, the following formula is applied. ΔT ₁ = ΔQ ₁ / (L ₁ × A ₁ × ρ ₁ × C ₁ ) (7) where i is the i-th mesh and T _i is the temperature (° C.) of the i-th mesh, Q _i is the heat storage amount of the i-th mesh (k
cal), A _i is the heat transfer area (m ² ), λ _i is the thermal conductivity (kcal / mh ° C.), ρ _i is the mesh density (kg /
m ³ ), C _i is the specific heat of the mesh (kcal / kg ° C.),
L _i is the length of the mesh (m), t is the time (h), Tp is the temperature of the hot metal (° C.), T _W is the temperature of the cooling water (° C.), and Up is the heat transfer coefficient in the furnace (kcal / m ^2). h °), Uw is the heat transfer coefficient on the cooling side (kcal / m ² h ° C.), and Hg is the latent heat of solidification and melting (kcal / kg) of the solidified layer.

The melting point of the innermost mesh in the furnace is 11
Assuming that the solidified layer 20 is 50 ° C., the hot metal temperature is 1500 ° C., and Up and Uw in the above equations are assumed values, T _{1 to} T ₇
Calculate each change over time. Further, by comparing with the line connecting the actually measured temperature values of the respective thermometers M ₁ and M ₂ for measurement, Up and Uw are subjected to the following procedure using the heat transfer inverse analysis method so as to minimize this error. Ask in. The actual measurement data measured at regular time intervals are j (Y ₁ , Y ₂ , Y ₃ ... Y _j ),
If there are j temperature values T (T ₁ , T ₂ , T ₃ ... T _j ) obtained by heat transfer calculation corresponding to the measured data j, the heat transfer coefficient U is T when slightly changed
The change of _j is calculated by the following formula. φ _j = ΔTj / ΔU (8) However, for φ _j , ΔTj is calculated by giving actual ΔU. Further, iterative calculation is performed using the following formula until U ′ that can minimize the error between the measured thermometers M ₁ and M ₂ is determined. U ′ = U + [2 × Σ (φ _j × Y _j ) −2 × Σ (φ _j × T _j )] / Σ (φ _j ² ) (9) where j is a time series Number of data (pieces), U is heat transfer coefficient (Kcal / m ² h ℃), φ _j is sensitivity coefficient (℃ m ² h ℃)
/ Kcal) U ′ is the heat transfer coefficient (Kcal / m ² h ° C.). Then, the in-reactor heat transfer coefficient Up and the cooling-side heat transfer coefficient Uw are set so that the transitions of the temperatures actually measured by the thermometers M ₁ and M ₂ substantially match the calculated values calculated using the above-described formula.
By calculating, the change in the heat transfer coefficient in the furnace according to the temperature change of the actual thermometers M ₁ and M ₂ can be calculated, and moreover, the solidification in accordance with the heat transfer coefficient Up in the furnace It is possible to accurately determine the state of layer reduction and growth.

Next, by using the measuring device 10, the heat transfer amount qp from the operating surface and the heat transfer amount qw on the cooling side as the heat transfer amount in the furnace.
The case of using will be described. T _{3 to} T ₆ are calculated by using the equations (1) and (2) described above, and using the past actual result qw, T
Calculate ₇ . ΔQ ₇ = [A ₇ × λ ₆ / L ₆ × (T ₆ −T ₇ ) + A ₈ × qw] × Δt (10) ΔT ₇ = ΔQ ₇ / (A ₇ × L ₇ × ρ ₇ × C ₇ ) (11) Using the past actual result qp, the solidification layer thickness L ₁ or the surface temperature T ₁ is calculated. ΔQ ₁ = [A ₁ × qp + A ₂ × λ ₁ / L ₁ × (T ₂ −T ₁ )] × Δt (12) However, when the solidified layer 20 exists, the following formula is applied. To do. ΔL ₁ = ΔQ ₁ / Hg / A ₁ (13) When the solidified layer 20 does not exist, the following formula is applied. ΔT ₁ = ΔQ ₁ / (L ₁ × A ₁ × ρ ₁ × C ₁ ) (14)

The melting point of the innermost mesh in the furnace is 11
Assuming that the solidified layer 20 is 50 ° C., the hot metal temperature is 1500 ° C., and qp and qw in the above equations are assumed values, T _{1 to} T ₇
Calculate each change over time. Further, by comparing with the line connecting the actually measured temperature values of the respective temperature control meters (thermometers) M ₁ and M ₂ , qp and qw are calculated using the inverse heat transfer analysis method so as to minimize this error. Follow the procedure of. J actual measurement data measured at regular intervals (Y ₁ , Y ₂ , Y ₃ ... Y
_j ), if there are j temperature values T (T ₁ , T ₂ , T ₃ ... T _j ) obtained by heat transfer calculation corresponding to the j measured data, the heat The change in T _j when the flow rate q is slightly changed is calculated by the following equation. _{φ j = ΔT j / Δq ·····} (15) However, phi _j, determined by calculation [Delta] T _j giving the actual [Delta] q. Further, iterative calculation is performed using the following formula until q'that can minimize the error between the measured thermometers M ₁ and M ₂ is determined. q ′ = q + [2 × Σ (φ _j × Y _j ) -2 × Σ (φ _j × T _j )] / Σ (φ _j ² ) (16) Here, j is a time series. The number of data (pieces), q is the heat transmission flow rate (Kcal / m ² h), φ _j is the sensitivity coefficient (° C m ² h /
Kcal) and q ′ are heat transmission flow rates (Kcal / m ² h). Then, the in-reactor heat-penetrating flow rate qp and the cooling-side heat-penetrating flow rate qw are set so that the calculated values calculated using the above-described equations substantially match the transitions of the temperatures actually measured by the thermometers M ₁ and M _2. By obtaining the value, it is possible to obtain the change in the in-furnace heat transmission flow rate according to the temperature change of the actual thermometers M ₁ and M ₂ , and moreover, the solidification layer is reduced according to this in-reactor heat transmission flow rate qp. The growth condition can be accurately determined.

As a result, the state of the heat transfer coefficient in the furnace can be accurately grasped in real time, and depending on the fluctuation of the heat transfer coefficient in the furnace, for example, the dense packing of the coke layer, the restriction on the use of the tap hole, the fuel ratio, etc. The conditions such as cooling can be changed.
By responding to the fluctuation of the heat transfer coefficient in the furnace, it is possible to prevent the wear of the furnace bottom refractory 16 and the abnormal formation of the solidified layer 20 and to extend the life of the blast furnace.

[0015]

EXAMPLE Next, an example of a method for controlling the lower part of the blast furnace will be described. Based on the transition of the temperature actually measured by the thermometers M ₁ and M ₂ , the calculation is performed using the formulas for obtaining the heat transfer coefficient Up in the furnace and the heat transfer coefficient Uw on the cooling side, and the calculated value is the measured temperature. The in-furnace heat transfer coefficient Up and the cooling-side heat transfer coefficient Uw were determined so as to be substantially equal to M ₁ and M ₂ . The results are shown in Fig. 3 ~
As shown in FIG. As shown in Fig. 3, the transition of the actual temperature change of the thermometers M ₁ and M ₂ over about 3 months exactly matches the temperature obtained by calculation (in the figure, the actual temperature thick line and the calculated temperature overlap). You can see that Furthermore, as shown in FIG. 4, the calculated heat transfer coefficient in the furnace is May / 15
Although it showed a downward trend after a day, the thermometers M ₁ and M described above
The calculated temperature of ₂ also decreased, and the trends of the calculated temperature and the heat transfer coefficient in the furnace agree well. And in FIG.
Since the thickness of the solidified layer 20 adhering to the surface of the furnace bottom refractory 16 began to increase as the heat transfer coefficient in the furnace decreased, as shown in FIG. The amount of water supplied to the water supply pipe 17 was reduced by operating the supply valve 18 and the drain valve 19, and the cooling condition of the bottom plate 15 was relaxed. The solidified layer 20 continued to increase in thickness despite relaxing the cooling conditions, but when it grew to a maximum thickness of 0.6 m, the effect of relaxing the cooling conditions contributed, and the thickness of the solidified layer 20 was reduced. Began to decrease. Therefore, the cooling action index was readjusted to 80 to 85%, and the thickness of the solidified layer 20 could be maintained at 0.3 to 0.4 m without any problem.

Next, an embodiment of the method for controlling the lower part of the blast furnace according to the present invention, particularly the method for controlling the side wall, will be described. As in the case of the the buried thermometer M _1, M ₂ of the furnace bottom refractory 16, the inside of the side wall refractories 14 lined on the side wall 13 of the furnace bottom 12, buried thermometer M _1, M ₂ , The in-reactor heat transfer coefficient Up and the cooling-side heat transfer coefficient Uw so that the measured temperature and the calculated value calculated by using the above-mentioned formula are substantially matched
I asked. The results are shown in FIGS. 7 to 1
As shown in Fig. 2, it can be seen that the actual temperature and the temperature obtained by the calculation are in good agreement, and furthermore, the heat transfer coefficient in the furnace also fluctuates satisfactorily in accordance with the variation in the actual temperature. In particular, after April 16 when the heat transfer coefficient in the furnace began to rise, the cooling heat transfer coefficient was also in a slow cooling state, so the thickness of the solidified layer rapidly decreased and the temperature of the operating surface also reached approximately 1275 ° C. Rose. Furthermore,
After June 10, the heat transfer coefficient in the furnace increased, the thickness of the solidified layer drastically decreased, the furnace bottom refractory 16 was worn, and the temperature of the operating surface rose to about 1305 ° C. Then, the frequency of tapping from the taphole in the vicinity was reduced, and at the same time, the amount of air blown from the tuyere in the vicinity was reduced according to the heat transfer coefficient Up in the furnace. Gradually decreased, the solidified layer could be stably increased after April 5, and Fig. 12
As shown in, the temperature of the operating surface could be stabilized at about 1150 ° C. In this way, it was possible to grasp the heat load in a non-steady state in which the heat load drastically fluctuates with respect to the operation side in real time, and to take action according to the situation. Furthermore, the heat transfer coefficient Up in the furnace and the heat transfer coefficient Uw on the cooling side
Even when the heat transmission flow rate qp and the cooling side heat transmission flow rate qw are used instead of the heat transmission flow rate qp, the heat transmission flow rate qp fluctuates well according to the fluctuation of the actual temperature, and the thickness of the solidified layer is stably managed. I was able to.

The embodiment of the present invention has been described above.
The present invention is not limited to the above-described embodiment, and changes in conditions and the like without departing from the spirit are all within the scope of application of the present invention. For example, in addition to M ₁ and M ₂ , the thermometer can be divided into 3 to 5 pieces of bottom plate and furnace bottom refractory, and can be provided in each, and also in the furnace wall, iron shell and side wall refractory 3 to 5
It can be divided into individual pieces and provided for each. Further, the measurement data of the thermometers M ₁ and M ₂ etc. can be input to a computer, the computer can perform calculation, and the result can be output from the computer to perform an action of operation.

[0018]

According to the method for controlling the lower part of the blast furnace according to the first to third aspects of the present invention, the blast furnace has a lower part of the blast furnace in the thickness direction inside the refractory.
By embedding a thermometer above the point, grasp the actual temperature transition using the temperature measured by the thermometer as a pair, and from the hot metal temperature at this time, assume the heat transfer amount in the furnace to the operating surface and the heat removal amount on the cooling side The unsteady heat transfer calculation was performed and calculated using the heat transfer inverse analysis method so that the obtained transition value of the temperature of the thermometer substantially matches the temperature actually measured by the thermometer. Since the heat removal amount on the cooling side and that on the cooling side are determined at the same time, the heat transfer amount in the furnace can be accurately grasped to estimate the heat load in the furnace, and the operation action of the blast furnace can be performed according to the heat load in the furnace. Stable operation and long life can be achieved.

Particularly, in the method for controlling the lower part of the blast furnace according to claim 2, the refractory material in the lower part of the furnace is divided into a plurality of calculation meshes, and the innermost mesh is a solidified product having a melting point at a predetermined temperature, Since the heat transfer amount and heat balance in the furnace that assume the heat transfer coefficient between the surface of the solidification layer and the hot metal are obtained, the solidification layer thickness at which the surface of the solidification layer becomes the melting point temperature is determined using the solidification melting latent heat of the solidification layer. It is possible to accurately grasp the thickness of the solidified layer formed in the lower part of the furnace, and depending on the state of the solidified layer, the packing density of coke, the number of tap holes used, the fuel ratio supplied to the furnace,
Operation actions such as cooling of the bottom plate can be selected and performed, and stable operation can be performed.

In the method for controlling the lower part of the blast furnace according to the third aspect, since the lower part of the blast furnace is applied to the bottom or side wall of the blast furnace, the refractory material in the furnace is determined from the heat balance of the part where the heat load of the blast furnace varies greatly. It is possible to accurately grasp the heat load of the blast furnace and perform appropriate operation action, and it is possible to achieve more stable operation and longer life of the blast furnace.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a measuring device applied to a method for controlling a lower part of a blast furnace according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a measurement site for heat transfer coefficient in the lower part of the blast furnace.

FIG. 3 is a graph showing the relationship between the elapsed days and the temperature of the bottom refractory of the blast furnace.

FIG. 4 is a graph showing the relationship between the elapsed days of the furnace bottom refractory and the heat transfer coefficient in the furnace.

FIG. 5 is a graph showing the relationship between the elapsed days of a furnace bottom refractory and the solidified layer thickness.

FIG. 6 is a graph showing the relationship between the elapsed days of the furnace bottom refractory and the bottom cooling action.

FIG. 7 is a graph showing the relationship between the elapsed days and the temperature of the furnace bottom refractory.

FIG. 8 is a graph showing the relationship between the elapsed days of the furnace bottom refractory and the heat transfer coefficient in the furnace.

FIG. 9 is a graph showing the relationship between the number of days elapsed in the furnace bottom refractory and the cooling heat transfer coefficient.

FIG. 10 is a graph showing the relationship between the elapsed days of the furnace bottom refractory and the solidified layer thickness.

FIG. 11 is a graph showing the relationship between the elapsed days of the furnace bottom refractory and the sidewall refractory residual thickness.

FIG. 12 is a graph showing the relationship between the elapsed days of the furnace bottom refractory and the operating surface temperature.

[Explanation of symbols]

10: Measuring device, 11: Blast furnace, 12: Lower part of furnace, 13: Side wall, 14: Side wall refractory material, 15: Bottom plate, 16: Furnace bottom refractory material, 17: Cooling water supply pipe, 18: Supply valve, 19: Discharge Valve, 20: Solidified layer, 21: Hot metal

Claims (3)

[Claims] 1. The thickness direction of the refractory in the lower part of the blast furnace is 2
A thermometer above the point is embedded, and the actual temperature transition is grasped by using the temperature measured by the thermometer as a pair, and the heat transfer amount inside the furnace to the operating surface and the heat removal amount on the cooling side are assumed from the hot metal temperature at this time. The unsteady heat transfer calculation was performed and calculated using the heat transfer inverse analysis method so that the transition value of the obtained temperature of the thermometer substantially matches the temperature actually measured by the thermometer. A method for controlling the lower part of a blast furnace, wherein the heat quantity and the heat removal quantity on the cooling side are simultaneously determined. 2. The blast furnace lower part management method according to claim 1, wherein the refractory material in the lower part of the furnace is divided into a plurality of calculation meshes, and the innermost mesh is a solidified layer having a melting point at a predetermined temperature, The amount of heat transfer in the furnace and the heat balance assuming the heat transfer coefficient between the surface of the solidification layer and the hot metal are obtained, and the solidification layer latent heat of the solidification layer is used to determine the solidification layer thickness at which the surface of the solidification layer becomes the melting point temperature. A method for managing the lower part of a blast furnace characterized by: 3. The method for managing a lower part of a blast furnace according to claim 1, wherein the lower part of the blast furnace is a bottom or a side wall of the blast furnace.