TW202134612A - Monitoring method for agglomeration on inner wall of blast furnace - Google Patents

Abstract

A monitoring method for agglomeration on inner wall of blast furnace is disclosed. A control volume having symmetrical surfaces is selected from a furnace body according to local symmetry of the furnace body. A grid temperature model of grids is established by using formulas, and the formulas are solved by a numerical method to obtain temperatures of the grids. A k value is adjusted by a lining thickness, an interior temperature of the furnace body, and a first sensed temperature to obtain a modified grid temperature model. A highest sensed temperature of a temperature sensor is obtained, and the highest sensed temperature and an interior temperature are applied to the modified grid temperature model to obtain a lining residual thickness. The lining residual thickness, a second sensed temperature, and an interior temperature are applied to the modified grid temperature model to obtain an agglomeration-layer thickness.

Description

Monitoring method for agglomeration of inner wall of blast furnace

The disclosed embodiment relates to a monitoring method of a blast furnace, and particularly relates to a monitoring method of agglomeration of the inner wall of the blast furnace.

In order to cope with the scouring of the high temperature gas inside the blast furnace body and reduce the wear of the charge, the inner lining and cooling system are generally installed on the inner side of the iron shell. During operation, the cooling effect of the cooling system will form a fouling layer on the hot surface of the inner wall of the furnace body. An appropriate thickness of the fouling layer has a positive effect on the life of the lining and energy saving. However, if the fouling layer is too thick, the so-called furnace wall agglomeration will be formed, which will adversely affect the production of molten iron and the life of the lining. Once large agglomerates are formed, it takes a lot of work to remove them, and the effect is uncertain. Therefore, the best policy should prevent the occurrence of abnormal agglomeration of the furnace wall.

At present, there are two most commonly used methods to grasp the agglomeration status of the blast furnace body. The first method is direct measurement, which uses the pressure measurement point to directly measure the residual thickness of the inner lining when the blast furnace is regularly repaired and shut down. However, this method has the following disadvantages. The interval between maintenance and shutdown of the furnace is several months, so the amount of data is very small, so that it is impossible to know the growth of agglomeration in real time, and it is impossible to distinguish whether there is a scaling layer. There are few pressure measuring points, so only the local position can be known. The pressure measuring point sometimes has iron condensed to make the measurement impossible.

The second method is the indirect inference method, which uses the furnace wall temperature and thermal load to indirectly determine the temperature measured by the thermocouple embedded in the furnace wall during the construction of the blast furnace, or the cooling by cooling elements through the furnace wall The incoming and outgoing water temperature is used to calculate the heat taken away (the so-called heat load). If the measured temperature is low or the heat load is low, it is qualitatively judged that there is agglomeration of the furnace wall. However, this method has the following disadvantages. The furnace wall temperature and heat load will be affected by the thickness of the lining, the temperature in the furnace, the thickness of the scale layer in the furnace, and the temperature and flow of the cooling water. If the temperature drop is completely attributed to the thickness of the scale layer, it is easy to produce Misjudgment. As the thickness of the fouling layer increases, the temperature of the furnace wall becomes more insensitive, and it is difficult to control the formation of agglomerates. Different locations of the blast furnace have different erosion mechanisms, the selected lining material and the configuration of the cooling elements are also different, even under the same residual thickness of the lining and the same thickness of the fouling layer, the temperature measurement value presented And heat load is also different, so there are blind spots in indirect judgment from temperature and heat load. The residual thickness of the lining and the thickness of the fouling layer cannot be quantitatively grasped.

Because the agglomeration of the furnace wall has a great influence on the operation stability of the blast furnace and the production capacity of molten iron, if there is no effective and accurate method for monitoring the scale layer in the operation of the blast furnace, it will not be possible to prevent abnormal agglomeration of the furnace wall in the first place. The temperature measurement point or heat load on the furnace wall is already quite low, and it is too late to feel the obvious signs of agglomeration.

The purpose of this disclosure is to provide a method for monitoring the agglomeration of the inner wall of a blast furnace, which can monitor the agglomeration of the inner wall of the blast furnace by controlling the volume, numerical solution, and sensed temperature, so as to take appropriate measures in time.

(1)、當x=X₀ 時，T=T_m (2)、當x=X_n 時，T=T_a (3)、以及

(4)。在上述式子中，k為控制體積之熱傳導係數，X₀ 為控制體積所對應之爐身之內壁面之x座標，T_m 為控制體積所對應之爐內溫度，X_n 為控制體積所對應之爐身之外壁面之x座標，T_a 為控制體積所對應之空氣溫度，n為對稱面之法線方向。以第一時間所對應之內襯厚度值、第一時間所對應之第一爐內溫度、及第一時間所對應之溫度感測器所感測之第一感測溫度來調整式(1)之k值，以得到修正格點溫度模型。取得對應控制體積之溫度感測器所感測到之最高感測溫度，並將最高感測溫度及最高感測溫度之感測時間所對應之爐內溫度應用於修正格點溫度模型，以得到控制體積所對應之內襯殘厚值。將內襯殘厚值、第二時間所對應之溫度感測器所感測之第二感測溫度、及第二時間所對應之第二爐內溫度應用於修正格點溫度模型，以得到控制體積所對應之結垢層厚度。According to the above objective, the disclosed embodiment provides a method for monitoring the agglomeration of the inner wall of a blast furnace. The blast furnace includes a furnace body and a plurality of temperature sensors. , The temperature sensor is installed in the furnace body. In the monitoring method, the control volume is selected from the furnace body according to the local symmetry of the furnace body, and one of the temperature sensors corresponds to the control volume, and the control volume has a plurality of symmetry planes. Divide the control volume into several grid points, use equations (1) to (4) to establish a grid point temperature model, and use a numerical solution method to solve equations (1) to (4) to obtain the grid points temperature.

(1) When x=X ₀ , T=T _m (2), when x=X _n , T=T _a (3), and

(4). In the above formula, k is the heat transfer coefficient _{of the control volume, X 0} is the x coordinate of the inner wall surface of the furnace body corresponding to the control volume, T _m is the temperature in the furnace corresponding to the control volume, and X _n is the control volume corresponding the outside wall of the furnace body coordinates x, T _a volume corresponding to the control of air temperature, n the normal direction of the plane of symmetry. Adjust the formula (1) by using the lining thickness value corresponding to the first time, the first furnace temperature corresponding to the first time, and the first sensing temperature sensed by the temperature sensor corresponding to the first time k value to get the modified grid point temperature model. Obtain the highest sensed temperature sensed by the temperature sensor corresponding to the control volume, and apply the temperature in the furnace corresponding to the highest sensed temperature and the sensing time of the highest sensed temperature to the modified grid temperature model to obtain control The residual thickness of the inner lining corresponding to the volume. Apply the lining residual thickness value, the second sensing temperature sensed by the temperature sensor corresponding to the second time, and the second furnace temperature corresponding to the second time to the modified grid temperature model to obtain the control volume The thickness of the corresponding fouling layer.

In some embodiments, the furnace shaft further includes a plurality of cooling plates. The cooling plate is arranged in the inner lining. The local symmetry of the furnace body is the local symmetry of the cooling plate, and the control volume is defined by the adjacent two of the cooling plate.

In some embodiments, the step of using a numerical solution method to solve the problem includes performing iterative calculations until the temperature difference between successive two calculations at each grid point is lower than a threshold.

In some embodiments, the numerical solution method is a difference method.

In some embodiments, adjusting the value of k in equation (1) includes adjusting the value of k until the calculated temperature of the temperature sensing position of the temperature sensor is the same as the first sensing temperature.

In some embodiments, applying the furnace temperature corresponding to the highest sensed temperature and the sensing time of the highest sensed temperature to the modified grid point temperature model includes: according to different simulated furnace temperatures and different simulated lining residual thicknesses Calculate the calculated temperature of the temperature sensing position of the temperature sensor to obtain the curve of the relationship between the calculated temperature and the residual thickness of the simulated lining at different simulated furnace temperatures; simulate separately with more than three polynomials These curves; and substituting the highest sensing temperature sensed by the temperature sensor into the polynomial corresponding to the furnace temperature corresponding to the sensing time of the highest sensing temperature to obtain the residual thickness value of the lining corresponding to the control volume .

In some embodiments, applying the inner lining residual thickness value, the second sensed temperature, and the second furnace temperature to the modified grid point temperature model includes: according to different simulated furnace temperature, different simulated erosion thickness, and Different simulated fouling layer thicknesses are used to calculate several calculated temperatures at the temperature sensing position of the temperature sensor to obtain the calculated temperature and simulated fouling layer thickness under different simulated furnace temperatures and different simulated erosion thicknesses The curve of the relationship; simulate these curves with three or more polynomials; and substitute the second sensing temperature into the polynomial corresponding to the lining residual thickness value and the second furnace temperature to obtain the scaled layer corresponding to the control volume thickness.

In some embodiments, the method for monitoring the agglomeration of the inner wall of the blast furnace further includes issuing a warning signal when the thickness of the fouling layer exceeds a threshold value.

In some embodiments, the method for monitoring the agglomeration of the inner wall of the blast furnace further includes displaying a monitoring screen, wherein the monitoring screen includes a planar expansion view of the control volume corresponding to the temperature sensors, and different colors represent the corresponding control volume The size of the thickness of the fouling layer.

In some embodiments, the method for monitoring the agglomeration of the inner wall of the blast furnace further includes displaying the flat development images corresponding to different times in chronological order.

To sum up, in the method for monitoring the agglomeration of the inner wall of the blast furnace disclosed in the present disclosure, the residual thickness of the inner lining and the thickness of the fouling layer are established by the control volume difference method, the numerical solution method, and the temperature sensed by the temperature sensor. The estimation method, and the fouling layer thickness of each control volume is presented on the monitor screen. The thickness of the fouling layer is displayed visually, and the relevant operating data is integrated into the same monitoring screen, so that the operator can grasp the fouling status of the furnace wall at any time, and take appropriate measures in time when there is an abnormality. In addition, the historical data can be played in automatic page turning mode, showing the growth and decline of the furnace wall fouling layer during the period of time to be observed, which is conducive to cause analysis and verification of the effect of measures taken, and provides the most powerful tool for furnace operators to avoid Abnormal agglomeration and take countermeasures.

In order to make the above-mentioned features and advantages of the present disclosure more obvious and understandable, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

The embodiments of the present disclosure are discussed in detail below. However, it can be understood that the embodiments provide many applicable concepts, which can be implemented in various specific contents. The discussed and disclosed embodiments are for illustration only, and are not intended to limit the scope of the disclosure. All the embodiments of the present disclosure disclose multiple different features, but these features can be implemented individually or in combination according to requirements. In addition, the "first", "second", etc. used in this text do not particularly refer to the meaning of order or sequence, but only to distinguish elements or operations described in the same technical terms. In addition, the spatial relationship between the two elements described in this disclosure is not only applicable to the orientation shown in the diagram, but also applicable to the orientation not shown in the diagram, such as an inverted orientation.

FIG. 1 is a schematic diagram of a blast furnace 10 applied in a method for monitoring agglomeration of the inner wall of a blast furnace according to an embodiment of the disclosure. Please refer to FIG. 1, the blast furnace 10 includes a furnace body 101 and a furnace base 102. The furnace base 102 is the bottom of the blast furnace 10, and the furnace body 101 is disposed on the furnace base 102 and combined with the furnace base 102 to form an accommodating space H. The blast furnace 10 further includes a plurality of blast nozzles 103 and a plurality of tap holes 104. The blast nozzle 103 penetrates the furnace base 102 and can provide hot air to the accommodating space H. The tap hole 104 is arranged in the furnace base 102 and located under the blast nozzle 103. The operator can perform the tapping operation through the tapping port 104. The accommodating space H can accommodate iron-making raw materials, as well as molten iron 105 and slag 106 generated after the iron-making raw materials are smelted. The molten iron 105 and the slag 106 are located at the bottom of the accommodating space H, and the slag 106 is located on the molten iron 105. In addition, in order to monitor the temperature of the furnace body 101, the blast furnace 10 further includes a plurality of temperature sensors 107. The temperature sensors 107 are inserted in the furnace body 101 and can sense the temperature of the furnace body 101. The temperature sensor 107 is, for example, a thermocouple. In an exemplary example, the temperature sensor 107 is arranged in the furnace body 101 in an 8-layer configuration, and each layer is provided with 8 temperature sensors 107, that is, there are 64 temperature sensors 107 in total, but this disclosure does not Limited to this. The 8 temperature sensors 107 on each layer are arranged around the furnace body 101 and can be arranged evenly.

In this embodiment, the range of the blast furnace 10 above the tuyere 103 is defined as the furnace body 101. FIG. 2 is an enlarged schematic diagram of a part of the furnace body 101 of FIG. 1 with a temperature sensor 107. Please refer to FIG. 2, the furnace body 101 includes an iron shell 201 and an inner lining 202. The inner lining 202 is arranged on the inner periphery of the iron shell 201 and can block the heat in the furnace from being transferred to the iron shell 201. The lining 202 includes a filler 203 and refractory bricks 204. The filling material 203 is arranged on the inner side of the iron shell 201. The refractory brick 204 is provided on one side of the filling material 203 and joined to the filling material 203. The filler 203 is located between the iron shell 201 and the refractory brick 204. The temperature sensor 107 is inserted in the furnace body 101, and further said to be inserted in the iron shell 201, the filling material 203, and part of the refractory brick 204. In addition, in order to take away the heat of the furnace body 101, the furnace body 101 of this embodiment may further include a plurality of cooling plates 205. The cooling plate 205 is arranged in the lining 202, and the cooling plate 205 is hollow to allow the heat exchange liquid to circulate. Several cooling plates 205 can form a heat dissipation unit. In one example, 4 or 6 cooling plates 205 constitute a heat dissipation unit, and have one inlet and one outlet, or multiple inlets and multiple outlets, to allow liquid to flow in and out, and part of the furnace body 101 The heat is taken away.

FIG. 3 is a flowchart of a method for monitoring agglomeration of the inner wall of a blast furnace according to an embodiment of the disclosure. The monitoring method of the present disclosure uses a control volume and a numerical solution method to monitor the agglomeration of the inner wall of the blast furnace. 3, in the monitoring method, step 301 is first performed to select a control volume from the furnace body 101 according to the local symmetry of the furnace body 101 and corresponding to one of the temperature sensors 107. The control volume has several symmetry planes. The purpose of selecting the control volume based on the local symmetry of the furnace body 101 is to reduce or simplify the calculation of the temperature distribution of the entire furnace body 101. The selected control volume is representative, so once a single control volume calculation mode is established, it can be applied to all control volumes of the furnace body 101. Since the control volume is selected according to the local symmetry of the furnace body 101, the control volume has multiple symmetry planes.

In this embodiment, the control volume is defined by two adjacent cooling plates 205. Please refer to FIG. 4, which is a schematic diagram of a part of the cooling plate 205 in the embodiment of the disclosure when viewed from the outside of the furnace body 101 into the furnace and is expanded in a plane. In this embodiment, the cooling plates 205 are evenly distributed on the furnace body 101, and the control volume CV is defined by two adjacent cooling plates 205. The control volume CV is representative, so the calculation amount of the entire furnace body 101 can be simplified. Please refer to FIG. 5, which is a perspective view of a control volume CV. The control volume CV has 4 symmetry planes S1~S4, and the normal vector system of these symmetry planes S1~S4 is perpendicular to the direction from the inside to the outside of the furnace. The control volume CV is connected to the other four adjacent control volumes via symmetry planes S1 to S4. In other words, two adjacent control volumes CV have a common symmetry plane. On this common symmetry plane, the two adjacent control volumes CV have the same temperature. For the control volume CV, the temperature change occurs along the direction from the surface S5 to the surface S6.

(1) 當x=X₀ 時，T=T_m (2) 當x=X_n 時，T=T_a (3)

(4)After selecting the control volume CV, proceed to step 302 to divide the control volume CV into several grid points, and use the following equations (1) to (4) to establish the grid point temperature model of these grid points, and use the numerical value Solving method to solve equations (1) to (4) to obtain the temperature of the grid point.

(1) When x=X ₀ , T=T _m (2) When x=X _n , T=T _a (3)

(4)

Equation (1) represents the energy balance of the furnace body 101 in a steady state, where k is the thermal conductivity of the control volume CV, and x, y, and z are the coordinate systems of the lattice temperature model. The x-axis direction is, for example, parallel to the direction from the inside of the furnace to the outside of the furnace.

Equation (2) is based on the assumption that the temperature on the inner wall surface of the furnace body 101 corresponding to the control volume CV is the same, for example, they are all the same as the average furnace temperature on the inner wall surface. The inner wall surface of the furnace body 101 corresponding to the control volume CV is, for example, the contact surface between the control volume CV and the furnace, which is represented by the surface S5 in FIG. 5. X ₀ is the x coordinate of the inner wall surface of the furnace body 101 corresponding to the control volume CV, for example, the x coordinate of the inner wall surface covered by the control volume CV. T _m is the temperature in the furnace corresponding to the control volume CV.

Equation (3) is based on the assumption that the temperature on the outer wall surface of the furnace body 101 corresponding to the control volume CV is equal to the air temperature. The outer wall surface of the furnace body 101 corresponding to the control volume CV is, for example, the contact surface between the control volume CV and the outside air, which is represented by the surface S6 in FIG. 5. X _n is the x coordinate of the outer wall surface of the furnace body 101 corresponding to the control volume CV, for example, the x coordinate of the outer wall surface covered by the control volume CV. T _a is the air temperature corresponding to the control volume CV. Here, it is also assumed that the air temperature corresponding to each control volume CV is the same.

Equation (4) is based on the assumption that the cooling plates 205 do not transfer heat to each other, where n is the normal direction of the symmetry plane S1~S4 in FIG. 5.

Solving equations (1) to (4) by using a numerical solution method includes performing iterative calculations until the temperature difference obtained by successive two calculations at each grid point is lower than the threshold. For example, in the 49th and 50th iterative calculations, if the temperature difference between each grid point is less than 0.001, the iterative calculation can be stopped. After the iterative calculation is completed, the temperature of each grid point can be obtained. The numerical solution method may be, for example, a difference method.

Since it is unknown whether the above-mentioned lattice temperature model is different from the actual situation, step 303 is performed to confirm the lattice temperature model. In step 303, the lining thickness value corresponding to the first time, the first furnace temperature corresponding to the first time, and the first sensing temperature sensed by the temperature sensor corresponding to the first time are used to adjust Formula (1) k value, and get the modified lattice temperature model. In one example, the first time refers to the initial stage of furnace opening, and the value of the lining thickness at this time is also called the original lining thickness value. For example, referring to Figure 2, at the beginning of the furnace opening, since the lining 202 of the furnace body 101 has not been consumed by the high-temperature airflow in the furnace, the thickness of the lining 202 is the original designed thickness, which is the formula (2 ) And formula (3) X ₀ and X _n are definite. Further, the initial opening of the furnace is the furnace temperature and the air temperature to be measured, thus the formula T _m (2) and the formula (3) and T _a is also determined. In addition, when designing the blast furnace, the temperature sensing position corresponding to the part of the temperature sensor 107 for sensing temperature is also determined. The temperature sensing position corresponds to a certain grid point or is located between two grid points, for example. In summary, the above and X ₀ and X _n T _a T _m and substituting the lattice model and calculated temperature, the temperature sensor sensing the temperature is calculated to obtain a temperature of 107 of position sensing. This calculated temperature can be compared with the actual temperature sensed by the temperature sensor 107, that is, the first sensed temperature, to know whether the lattice temperature model is different from the actual situation. If there is a difference, the parameters of the lattice temperature model can be adjusted, such as the thermal conductivity k of the control volume CV, until the calculated temperature of the temperature sensor 107 is the same as the actual sensed temperature. After this step, it can be confirmed that the lattice point temperature model represented by formula (1) to formula (4) conforms to the actual situation.

In addition to using the original lining thickness value at the beginning of the furnace to confirm the lattice temperature model, the residual thickness value of the lining measured during the fixed repair period can also be used to confirm the model. At this time, the first The time is the designated repair period. Since the fixed repair is carried out after the blast furnace has been operating for a certain period of time, the lining of the furnace body should have been eroded, and the thickness of the lining at this time is called the residual thickness value. In one embodiment, the residual thickness can be calculated from the outer wall surface of the iron shell 201. Similarly, the lining thickness value corresponding to the fixed repair period, the first furnace temperature before the start of the fixed repair period, and the first sensor sensed by the corresponding temperature sensor before the start of the fixed repair period can be used Adjust the value of k in equation (1) by temperature to obtain a modified lattice temperature model.

After the modified grid point temperature model is obtained, step 304 may be performed to obtain the residual thickness value of the lining by using the modified grid point temperature model. In step 304, obtain the highest sensed temperature sensed by the temperature sensor corresponding to the control volume, and apply the highest sensed temperature and the temperature in the furnace corresponding to the sensing time of the highest sensed temperature to the correction grid Point the temperature model to obtain the residual thickness of the inner lining corresponding to the control volume. The high temperature air flow in the furnace will consume the lining, so that the thickness of the lining decreases with the increase of the process time. When the residual thickness of the inner lining is smaller, the heat blocking effect of the inner lining decreases, so that the temperature sensed by the temperature sensor will be higher. However, when the fouling layer begins to form on the inner wall of the lining, the fouling layer will instead provide a heat blocking effect, so that the temperature sensed by the temperature sensor will begin to drop. Therefore, the highest sensing temperature sensed by the temperature sensor means that the erosion loss of the inner lining has reached the maximum, and the thickness of the inner lining at this time is the residual thickness of the inner lining.

In step 304, according to different simulated furnace temperatures and different simulated lining residual thickness values, a plurality of calculated temperatures of the temperature sensing position of the temperature sensor may be calculated to obtain the temperature at different simulated furnace temperatures. , The curve of the relationship between the calculated temperature of the temperature sensing position of the temperature sensor and the residual thickness of the simulated lining. _{By adjusting the value of T m} in the above formula (2), the calculation can be performed under different simulated furnace temperatures. _{By adjusting the values of X 0} and X _n in the above equations (2) and (3), calculations can be performed under different simulated lining residual thickness values. In one example, _{the distance from X 0} to X _n is equal to the residual thickness of the lining. Please refer to FIG. 6, which is a graph showing the relationship between the calculated temperature (vertical axis) and the erosion thickness (horizontal axis) of the temperature sensing position of the temperature sensor based on different simulated furnace temperatures. Please note that the horizontal axis in Figure 6 is not the residual lining thickness value, but due to the relationship between the residual lining thickness value + erosion thickness = the original lining thickness value, the simulated erosion thickness can be converted into a simulated lining residual thickness with certainty. Thickness (and vice versa). Therefore, the graph of FIG. 6 can be converted into a graph that simulates the relationship between the residual thickness of the inner lining (vertical axis) and the calculated temperature of the temperature sensing position of the temperature sensor (horizontal axis). After obtaining a graph that simulates the relationship between the residual thickness of the lining and the calculated temperature of the temperature sensing position of the temperature sensor, these curves can be simulated by a polynomial of more than three times to facilitate subsequent calculations. In one example, these curves are respectively simulated by a plurality of third-degree polynomials. The cubic polynomial is as follows: E _R =(C ₁ +C ₂ T+C ₃ T ² +C ₄ T ³ )/1000 (5)

In formula (5), E _R is the residual thickness of the inner lining, and C ₁ to C ₄ are regression coefficients. When the historical highest temperature sensed by the temperature sensor, that is, the highest sensed temperature, is substituted into the T of equation (5) corresponding to the furnace temperature corresponding to the sensing time of the highest sensed temperature, the temperature sensing can be obtained The residual thickness of the inner lining corresponding to the control volume corresponding to the measuring instrument.

After the residual thickness of the inner lining is obtained, step 305 can be performed to obtain the thickness of the fouling layer by using the modified lattice temperature model. 3, in step 305, the residual thickness of the inner lining, the second sensing temperature of the temperature sensor corresponding to the second time, the second furnace temperature corresponding to the second time, and the modified grid point are used The temperature model is used to obtain the thickness of the scaled layer corresponding to the control volume. The second time may be a time after the residual thickness of the inner lining is obtained. In this step, first use different simulated furnace temperatures, different simulated erosion thicknesses (which can be converted into lining residual thickness values), and different simulated fouling layer thicknesses to calculate the temperature sensing position of the temperature sensor The calculated temperature is used to obtain the curve of the relationship between the calculated temperature of the temperature sensing position of the temperature sensor and the thickness of the simulated fouling layer under different simulated furnace temperatures and different simulated erosion thicknesses. _{By adjusting the value of T m} in the above formula (2), calculations can be made for different simulated furnace temperatures. _{Since the distance from X 0} to X _n in the above equations (2) and (3) is equal to the simulated lining residual thickness value (which can be converted into simulated erosion thickness) plus the simulated fouling layer thickness, by adjusting X ₀ With _{the value of X n} , the modified grid point temperature model can be used to calculate for different simulated erosion thicknesses and simulated fouling layer thicknesses.

Please refer to Figure 7, which is based on different simulated furnace temperatures and different simulated erosion thicknesses to calculate the calculated temperature of the temperature sensing position of the temperature sensor (vertical axis) and simulated fouling layer thickness (horizontal axis) Graph of relationship. It should be noted that, for the convenience of subsequent substitutions, the graph of Figure 7 is calculated as the relationship between the calculated temperature (horizontal axis) of the temperature sensing position of the temperature sensor and the thickness of the simulated fouling layer (vertical axis). Graph. After the graph is obtained, a polynomial of more than three degrees can be used to simulate these curves to facilitate subsequent calculations. In one example, these curves are respectively simulated by a plurality of third-degree polynomials. The third degree polynomial is as follows: S _R =(A ₁ +A ₂ T+A ₃ T ² +A ₄ T ³ )/1000 (6)

In formula (6), S _R is the thickness of the fouling layer, and A ₁ to A ₄ are regression coefficients. Before substituting, first use the residual thickness value of the inner lining obtained by formula (5) to obtain the actual erosion thickness. Then, when the second sensing temperature sensed by the temperature sensor is substituted into the above-mentioned actual erosion thickness and the second furnace temperature corresponding to the formula (6) T, the temperature corresponding to the temperature sensor can be obtained Control the thickness of the scaling layer corresponding to the volume.

Through the operations of the above steps 301 to 305, the thickness of the scaled layer corresponding to the control volume corresponding to a single temperature sensor can be obtained. These operations can be extended to the control volumes corresponding to all temperature sensors, and the thickness of the fouling layer corresponding to each control volume can be obtained. As for the control volume corresponding to no temperature sensor, the control volume with the corresponding temperature sensor can be used for interpolation calculation to obtain the temperature distribution, the residual thickness of the lining, and/or the thickness of the fouling layer.

It should be noted that the above embodiment is based on each control volume corresponding to one temperature sensor, but the disclosed embodiment may include each control volume corresponding to multiple temperature sensors, which can also use the principle of the above embodiment to Implement. In addition, the monitoring method of the embodiment of the present disclosure can also be used in a blast furnace that uses a cooling stave as a cooling mechanism. Similarly, the control volume of the furnace body can be selected first according to the local symmetry of the furnace body of the blast furnace, and then follow the above steps to obtain the thickness of the scale layer corresponding to each control volume.

The monitoring method of the embodiment of the present disclosure may further include sending a warning signal when the thickness of the fouling layer exceeds a threshold. The threshold can be set to a fixed value or an adjustable value, where the adjustable value is, for example, adjusted with the time of the process. The threshold value may also be a relational expression, and the parameters of the relational expression include, for example, the original lining thickness value, the residual lining thickness value, the thickness of the fouling layer obtained last time, or a combination thereof. The warning signal can be a sound or a visual effect, and the visual effect can include images, text, symbols, or a combination thereof.

The monitoring method of the embodiment of the present disclosure may further include displaying a monitoring screen, wherein the monitoring screen includes a planar expansion view of the control volume corresponding to all temperature sensors, and different colors represent the thickness of the scale layer corresponding to each control volume size. Please refer to FIG. 8, which is a monitoring picture P according to an embodiment of the disclosure. In block A, the display furnace body and the temperature sensors arranged on the furnace body are distributed on the 8th floor, that is, the S1~S8 floor. The temperature sensor used in the foregoing embodiment is, for example, one of the temperature sensors in the S3 layer. In block B, the control volume corresponding to the S1~S8 layer is displayed in the vertical direction, and the control volume corresponding to the 8 temperature sensors corresponding to each layer is displayed in the horizontal direction, so there are 64 control volumes in total, and different The color represents the thickness of the fouling layer. The related operation data and the thickness of the scaling layer corresponding to the control volume are integrated into the monitoring screen P shown in Fig. 8, so that the operator can grasp the scaling status of the furnace wall at any time. The operator can detect the thickness of the fouling layer by watching the monitoring screen P shown in FIG. 8, and then obtain intuitive and efficient detection results, and take corresponding measures. In addition to the planar expansion view of the control volume, the monitoring method of the embodiment of the present disclosure can also generate a three-dimensional view of the control volume, that is, the three-dimensional image of the furnace body and the control volume on it are displayed.

The monitoring method of the embodiment of the present disclosure may further include playing the corresponding flat unfolded view in time sequence. With a preset interval time as a unit, the historical data is played in a way of automatically turning pages, showing the growth and decline of the fouling layer during the time period to be observed, which is conducive to cause analysis and measures.

It can be seen from the above description that in the method for monitoring the agglomeration of the inner wall of the blast furnace disclosed in the present disclosure, the residual thickness of the inner lining and the thickness of the fouling layer are established by the control volume difference method, the numerical solution method, and the temperature sensed by the temperature sensor. The estimation method, and the fouling layer thickness of each control volume is presented on the monitor screen. The thickness of the fouling layer is displayed visually, and the relevant operating data is integrated into the same monitoring screen, so that the operator can grasp the fouling status of the furnace wall at any time, and take appropriate measures in time when there is an abnormality. In addition, the historical data can be played in automatic page turning mode, showing the growth and decline of the furnace wall fouling layer during the period of time to be observed, which is conducive to cause analysis and verification of the effect of measures taken, and provides the most powerful tool for furnace operators to avoid Abnormal agglomeration and take countermeasures.

The features of several embodiments are summarized above, so those who are familiar with the art can better understand the aspect of the present disclosure. Those who are familiar with this technique should understand that they can easily use the present disclosure as a basis to design or modify other processes and structures, thereby achieving the same goals and/or the same advantages as the embodiments described herein. . Those who are familiar with this art should also understand that these equivalent constructions do not depart from the spirit and scope of this disclosure, and they can make various changes, substitutions and alterations without departing from the spirit and scope of this disclosure.

10: Blast furnace 101: furnace body 102: Stove base 103: blast mouth 104: tap hole 105: Hot Metal 106: Slag 107: temperature sensor 201: iron shell 202: Lining 203: Filler 204: Refractory Brick 205: cooling plate 301~305: steps A, B: block CV: Control volume H: accommodating space P: Monitoring screen S1~S4: symmetry plane S5, S6: surface

From the following detailed description in conjunction with the accompanying drawings, a better understanding of the aspect of the present disclosure can be obtained. It should be noted that, according to industry standard practice, each feature is not drawn to scale. In fact, in order to make the discussion clearer, the size of each feature can be increased or decreased arbitrarily. [Fig. 1] is a schematic diagram of a blast furnace applied in a method for monitoring agglomeration of the inner wall of a blast furnace according to an embodiment of the disclosure. [Figure 2] is an enlarged schematic diagram of the part of the blast furnace with temperature sensors in [Figure 1]. [Figure 3] is a flowchart of a method for monitoring agglomeration of the inner wall of a blast furnace according to an embodiment of the disclosure. [Fig. 4] is a schematic diagram of the cooling plate of the disclosed embodiment viewed from the outside of the furnace body into the furnace and is expanded in a plane. [Figure 5] is a perspective view of a controlled volume. [Figure 6] is a graph showing the relationship between the calculated temperature (vertical axis) and the simulated erosion thickness (horizontal axis) of the temperature sensing position of the temperature sensor based on different simulated furnace temperatures. [Figure 7] The relationship between the calculated temperature (vertical axis) and the simulated fouling layer thickness (horizontal axis) of the temperature sensing position of the temperature sensor is calculated based on different simulated furnace temperatures and different simulated erosion thicknesses Graph. [Figure 8] is a monitoring screen of an embodiment of the disclosure.

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301~305: steps

Claims (10)

A method for monitoring the agglomeration of the inner wall of a blast furnace, wherein the blast furnace includes a furnace body and a plurality of temperature sensors, the furnace body includes an iron shell and an inner lining, and the inner lining is arranged on an inner periphery of the iron shell, The temperature sensors are installed in the furnace body, and the monitoring method includes: selecting a control volume from the furnace body according to the local symmetry of the furnace body and corresponding to one of the temperature sensors, the control The volume has multiple symmetry planes; divide the control volume into multiple grid points, use equations (1) to (4) to establish a temperature model of one of the grid points, and use a numerical solution method to solve the equation (1) to the formula (4) to obtain the temperature of the grid points,

(1) When x=X ₀ , T=T _m (2) When x=X _n , T=T _a (3)

(4) where k is a thermal conductivity coefficient of _{the control volume, X 0} is the x coordinate of an inner wall surface of the furnace body corresponding to the control volume, T _m is a furnace temperature corresponding to the control volume, X _n for controlling the volume of the corresponding one of the outer wall surface of the furnace body coordinates x, T _a corresponding one of the air temperature for controlling the volume, n the normal direction for some of the plane of symmetry; corresponding to a first time A lining thickness value, a first furnace temperature corresponding to the first time, and a first sensing temperature sensed by the one of the temperature sensors corresponding to the first time to adjust the The value of k in formula (1) is used to obtain a modified lattice temperature model; one of the highest sensed temperatures sensed by the one of the temperature sensors corresponding to the control volume is obtained, and the highest sensed temperature, And a furnace temperature corresponding to a sensing time of the highest sensing temperature is applied to the modified grid point temperature model to obtain a lining residual thickness value corresponding to the control volume; and the lining residual thickness value A second sensing temperature sensed by the one of the temperature sensors corresponding to a second time, and a second furnace temperature corresponding to the second time are applied to the modified grid point temperature model, To obtain the thickness of a fouling layer corresponding to the control volume. The monitoring method according to claim 1, wherein the furnace body further comprises: A plurality of cooling plates are arranged in the lining, the local symmetry of the furnace body is the local symmetry of the cooling plates, and the control volume is defined by the adjacent two of the cooling plates. The monitoring method according to claim 1, wherein using the numerical solution method to solve the equations (1) to (4) includes performing iterative calculations until the temperature difference obtained by successive two calculations of each of the grid points Below a threshold. The monitoring method according to claim 1, wherein the numerical solution method is a difference method. The monitoring method according to claim 1, wherein adjusting the value of k in the formula (1) includes adjusting the value of k until one of the temperature sensing positions of the temperature sensors calculates the temperature and the first sensor The measured temperature is the same. The monitoring method according to claim 1, wherein applying the temperature in the furnace corresponding to the highest sensing temperature and the sensing time of the highest sensing temperature to the modified grid point temperature model comprises: Calculate a plurality of calculated temperatures of one of the temperature sensing positions of the temperature sensors according to a plurality of simulated furnace temperatures and a plurality of simulated lining residual thickness values to obtain the temperatures in the different simulated furnaces Next, the curves of the relationship between the calculated temperature and the residual thickness of the simulated lining; Simulate the curves with a plurality of polynomials of more than three times; and Substituting the highest sensing temperature sensed by the one of the temperature sensors into one of the polynomials corresponding to the furnace temperature corresponding to the sensing time of the highest sensing temperature to obtain the The residual thickness of the lining corresponding to the control volume. The monitoring method according to claim 1, wherein applying the residual lining thickness value, the second sensed temperature, and the second furnace temperature to the modified grid point temperature model comprises: According to a plurality of simulated furnace temperatures, a plurality of simulated corrosion loss thicknesses, and a plurality of simulated fouling layer thicknesses, a plurality of calculated temperatures of one of the temperature sensing positions of the temperature sensors are calculated to obtain different temperatures. The curves of the relationship between the calculated temperature and the thickness of the simulated fouling layer under the temperature in the simulated furnace and the different simulated erosion thickness; Simulate the curves with a plurality of polynomials of more than three times; and Substituting the second sensed temperature into one of the polynomials corresponding to the lining residual thickness value and the second furnace temperature to obtain the scaled layer thickness corresponding to the control volume. The monitoring method as described in claim 1, further comprising: When the thickness of the fouling layer exceeds a threshold, a warning signal is issued. The monitoring method as described in claim 1, further comprising: A monitoring screen is displayed, wherein the monitoring screen includes a planar expanded view of the control volumes corresponding to the temperature sensors, and different colors represent the thickness of the scaled layers corresponding to the control volumes. The monitoring method according to claim 9, further comprising: Play the flat expansion map corresponding to different times in chronological order.

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