Method for visualizing the degree of erosion of carbon bricks in a hearth

Abstract

The application discloses a method for visualizing the erosion degree of hearth carbon bricks, which comprises the following steps: firstly, obtaining the linear relationship between the thermal conductivity of carbon bricks and temperature of intact layers by using the data during the blowing-in period; secondly, dividing the carbon bricks into different regions according to the erosion change of the carbon bricks; thirdly, calculating the temperature of the boundary line between the intact layer and the embrittlement layer by using the linear relationship between the thermal conductivity and temperature and combining the heat flux equivalence principle; and fourthly, calculating and visualizing the residual thickness of the hearth carbon bricks based on the boundary line temperature and the thermal conductivity of the embrittlement layer and the iron infiltration layer. The application calculates the relationship between the thermal conductivity of the residual carbon bricks and the temperature of the intact layer and the structural change of the carbon bricks after the actual erosion, and the obtained result can more accurately reflect the erosion degree of the carbon bricks, and the calculation result is visualized, so that the measures favorable to the safety of the hearth are guided, the risk of the hearth burning through is reduced, a scientific theoretical basis for improving the service life of the blast furnace is provided, and the application has a wide application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of blast furnace smelting, and particularly relates to a method for establishing visualization of erosion degree of carbon brick of hearth. BACKGROUND

[0002] With the development of ironmaking technology, China's blast furnace has made major breakthroughs in green, high efficiency, and long life technologies. For a long time, the hearth is a limiting factor for the long life of the blast furnace, and the residual thickness of the carbon brick is the main way to evaluate the life of the hearth. Due to the "black box" characteristics of the blast furnace, it is not possible to directly measure the carbon brick of the hearth, so the method of embedding a thermocouple in the carbon brick is often used to measure the temperature of the carbon brick, and then the residual thickness of the carbon brick is calculated according to the Fourier heat conduction law, so as to achieve the purpose of monitoring the erosion degree of the carbon brick of the hearth. However, the structural changes of the carbon brick caused by erosion and the changes of the thermal conductivity of each structure layer and the influence of temperature on the thermal conductivity are not fully considered in the calculation process, so that the calculation result is greatly different from the actual result.

[0003] In the prior art, a high-precision calculation method for residual thickness of carbon brick of blast furnace hearth is disclosed in the patent with publication number CN 114896546 A. First, the boundary conditions are selected, and then the thermal conductivity of the carbon brick is brought into the heat transfer formula in the form of a function of temperature, and then the erosion line position and erosion degree of the blast furnace at the end of service are calculated. However, this calculation method does not take into account the structural changes of the carbon brick after erosion and the inconsistent thermal conductivity between each structure, and still considers that the structure of the whole carbon brick is consistent during the calculation process, resulting in a certain deviation between the actual result and the calculation result.

[0004] Therefore, it is necessary to design a method for establishing visualization of erosion degree of carbon brick of hearth to solve the above problems. SUMMARY

[0005] The present application aims to provide a method for establishing visualization of erosion degree of carbon brick of hearth, which utilizes the linear relationship between the thermal conductivity of the carbon brick of the intact layer and the temperature established during the blowing period, calculates the temperature of the boundary line between the intact layer and the embrittlement layer of the carbon brick at the later stage of the service life by the heat flux equivalence principle, corrects the important characteristic that the thermal conductivity of the intact layer of the carbon brick changes with temperature, and calculates the thickness of the intact layer of the carbon brick based on the boundary line temperature. Meanwhile, the carbon brick is divided into intact layer, embrittlement layer and iron infiltration layer along the radial direction of the hearth according to the erosion changes of the carbon brick, and the thicknesses of the embrittlement layer and the iron infiltration layer of the carbon brick are calculated by using the thermal conductivities of the embrittlement layer and the iron infiltration layer, so as to accurately and intuitively reflect the erosion degree of the carbon brick.

[0006] To achieve the above-mentioned application purposes, the present application provides a method for establishing visualization of erosion degree of carbon brick of hearth, which comprises the following steps:

[0007] S1, collecting the hot blast furnace hearth period and non-blast furnace hearth position and temperature data of thermocouple arrangement, the hot blast furnace period is recorded as Tf, the insertion depth of the thermocouple close to the center of the blast furnace is recorded as H3, and the temperature data of the thermocouple in the hot blast furnace period and non-blast furnace period is pretreated;

[0008] S2, based on the principle of radial heat flux of blast furnace hearth and combined with the thermocouple data in the hot blast furnace period, the linear relationship of thermal conductivity-temperature of carbon brick intact layer is obtained;

[0009] S3, the residual carbon brick of the hearth is divided into intact layer, brittle layer and iron infiltration layer along the radial direction of the hearth, the thickness of each region layer is recorded as L1, L2 and L3 respectively, the thermal conductivity of the brittle layer and the iron infiltration layer is obtained, the size relationship between the thickness L1 of the intact layer and the insertion depth H3 of the thermocouple close to the center of the blast furnace is judged by coupling calculation, and the calculation of the brittle layer and the brittle layer of the intact layer is carried out according to the judgment result and the linear relationship of thermal conductivity-temperature in step S2.

[0010] S4, taking 1150℃ as the critical point of the hot surface temperature of the hearth, 907℃ as the demarcation temperature point of the brittle layer and the iron infiltration layer, and combining with the real-time thermocouple temperature, the thickness L2 of the brittle layer and the thickness L3 of the iron infiltration layer are calculated.

[0011] S5, repeating steps S1-S4, calculating the length L1, L2 and L3 of the carbon brick intact layer, brittle layer and iron infiltration layer at different heights h of the hearth, and using interpolation algorithm to make the discrete points continuous, obtaining the visualization diagram of the erosion degree of the carbon brick in the hearth.

[0012] As a further improvement of the application, in step S1, at least three thermocouples 1, 2 and 3 with different insertion depths are arranged in the hearth, the calculation starting point of the insertion depth is the starting point of the carbon brick close to the furnace shell, the insertion depths are H1, H2 and H3 respectively, and H1

[0013] As a further improvement of the application, in step S2, the linear relationship of thermal conductivity-temperature of the carbon brick intact layer is:

[0014] λ=f(t)=λ c +b(t-t c )

[0015] b = 2λ c [(H2-H1)(Tf3-Tf2)-(H3-H2)(Tf2-Tf1)]x[(H3-H2)(Tf2-Tf1)(Tf2+Tf1-2tc)-(H2-H1)(Tf3-Tf2)(Tf3+Tf2-2tc)] -1

[0016] wherein λ c is the temperature t c The thermal conductivity coefficient of the lower carbon brick is detected before leaving the factory, and b is the temperature coefficient.

[0017] As a further improvement of the present application, in step S3, the coupling calculation is to calculate the heat flux difference value c between the thermocouple 1, 2 and the thermocouple 2, 3, to determine the relationship between the intact layer thickness L1 and H3.

[0018] As a further improvement of the present application, if c is greater than the preset difference value a, it is considered that L1

[0019]

[0020] wherein q 21 is the heat flux between the thermocouple 1, 2, q 32 is the heat flux between the thermocouple 2, 3.

[0021] As a further improvement of the present application, the calculation formula of q 21 and q 32 is as follows:

[0022]

[0023]

[0024] wherein f(T1), f(T2), f(T3) represent the thermal conductivity coefficient of the intact layer at the temperature of the thermocouple 1, 2, 3.

[0025] As a further improvement of the present application, when L1

[0026] q 12 = q 2T0 = q 3T0

[0027] wherein q 2T0 is the heat flux between the thermocouple 2, T0, q 3T0 is the heat flux between the thermocouple 3, T0, q 2T0 and q 3T0The calculation formula of f (T0) is as follows:

[0028]

[0029]

[0030] Wherein, f (T0) represents the intact layer thermal conductivity at T0 temperature, λ2 represents the thermal conductivity of the embrittlement layer;

[0031] The calculation formula of the intact layer and the embrittlement layer boundary temperature T0 and the intact layer thickness L1 is as follows:

[0032]

[0033]

[0034] Wherein, λ c is the thermal conductivity of the carbon brick at the factory detection at temperature tc, and b is the temperature coefficient.

[0035] As a further improvement of the application, when L1>H3, it indicates that the carbon brick residual state is good, L1=H3 is taken, and the calculation formula of the intact layer and the embrittlement layer boundary temperature T0 and the intact layer thickness L1 is as follows:

[0036] T0=T3

[0037] L1=H3.

[0038] As a further improvement of the application, in step S4, the calculation method of the embrittlement layer thickness L2 and the iron permeation layer thickness L3 is as follows:

[0039] Based on the principle of equal intensity of radial heat flow of blast furnace:

[0040] q 12 =q 34 =q 45

[0041] Wherein, q 34 is the heat flux between thermocouple 3 and 907℃, q 45 is the heat flux between 907℃ and 1150℃, and the calculation formula of q 45 is as follows:

[0042]

[0043] Wherein, λ3 represents the thermal conductivity of the iron permeation layer;

[0044] The calculation formula of the iron permeation layer L3 is as follows:

[0045]

[0046] When L1 < H3, q 34 The calculation formula of L2 is as follows:

[0047]

[0048] The calculation formula of L2 is as follows:

[0049]

[0050] When L1 > H3, q 34 The calculation formula of L2 is as follows:

[0051]

[0052] The calculation formula of L2 is as follows:

[0053]

[0054] Wherein, b is the temperature coefficient.

[0055] As a further improvement of the application, steps S1-S4 are repeated, the lengths L1, L2 and L3 of the carbon brick intact layer, the embrittlement layer and the iron infiltration layer at different heights h of the furnace hearth are calculated, and the length and height information of the boundary lines of the carbon brick intact layer-embrittlement layer, embrittlement layer-iron infiltration layer and iron infiltration layer-iron are marked, and are sequentially recorded as (L1, h), (L1+L2, h) and (L1+L2+L3, h). The discrete boundary points of each erosion layer at different heights of the carbon brick are continuous by using the Bezier interpolation algorithm, and a visualization diagram of the erosion degree of the carbon brick of the furnace hearth is obtained.

[0056] The beneficial effects of the application are:

[0057] 1. The application can verify the accuracy of the formula calculation by using the position and temperature data of the thermocouple during the blowing period, and the actual length of the intact layer of the carbon brick during the blowing period is not eroded, which can facilitate the verification of the accuracy of the formula calculation, and the carbon brick heat conductivity-temperature linear relationship formula of the intact layer is obtained, so that the formula is used in the middle and later periods, and the boundary line temperature of the intact layer and the embrittlement layer is calculated by combining the heat flux equalization principle, and the accurate thickness of the carbon brick intact layer is calculated based on the boundary line temperature.

[0058] 2. The present application divides the carbon bricks along the radial direction of the hearth into sound layers, embrittlement layers and iron infiltration layers according to the erosion changes of the carbon bricks, and based on the temperature distribution characteristics of each layer area, fully considers the physical properties of the thermal conductivity coefficient of the sound layer of the carbon bricks changing with temperature and the characteristics of the structure of the carbon bricks changing from a whole sound to sound layers, embrittlement layers and iron infiltration layers after erosion, and uses the sound layer and embrittlement layer demarcation line temperature calculated by the linear relationship between the thermal conductivity coefficient of the sound layer of the carbon bricks and temperature, and the thermal conductivity coefficient of the embrittlement layer and iron infiltration layer, to calculate the residual thickness of the carbon bricks and establish the visualization of the erosion degree, so as to avoid the large deviation between the calculated results and the actual results of the residual thickness of the carbon bricks due to not fully considering the relationship between the actual thermal conductivity coefficient of the sound layer of the carbon bricks changing with temperature and the large change of the thermal conductivity coefficient of the carbon bricks after erosion, so that the calculated residual thickness of the carbon bricks is more accurate, and the visualization of the erosion degree of the carbon bricks can more intuitively reflect the erosion condition of the carbon bricks.

[0059] 3. The calculation method of the present application is simple, the data is easy to obtain, and the operability is strong, based on the relationship between the thermal conductivity coefficient of the sound layer of the residual carbon bricks changing with temperature and the characteristics of the structure change and the corresponding change of the thermal conductivity coefficient of the carbon bricks after actual erosion, the thickness of the carbon bricks is calculated in different regions, and the calculation results can more accurately reflect the erosion degree of the carbon bricks, so as to guide the measures beneficial to the safety of the hearth and reduce the risk of the hearth burning through, provide a scientific theoretical basis for improving the service life of the blast furnace, and have a wide application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0060] Figure 1 It is the design idea diagram for the establishment method of the visualization of the erosion degree of the hearth carbon bricks of the present application.

[0061] Figure 2 It is a schematic diagram of the arrangement position of the thermocouple of the present application.

[0062] Figure 3 It is a visualization diagram of the erosion degree of the hearth carbon bricks of the present application. DETAILED DESCRIPTION

[0063] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be described in detail below in combination with the drawings and specific embodiments.

[0064] Here, it also needs to be explained that, in order to avoid the unnecessary details from blurring the present application, only the structures and / or processing steps closely related to the scheme of the present application are shown in the drawings, and other details not closely related to the present application are omitted.

[0065] It is also important to note that the term "comprising" or "including" or any other variation thereof is intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0066] The application provides a method for visualizing the erosion degree of a hearth carbon brick, comprising the following steps:

[0067] S1, collecting the temperature data of the hearth thermocouple arrangement position during the blowing period and the non-blowing period of the blast furnace, recording the temperature of the thermocouple during the blowing period as Tf, recording the insertion depth of the thermocouple close to the center of the blast furnace as H3, and preprocessing the temperature data of the thermocouple during the blowing period and the non-blowing period;

[0068] S2, obtaining the linear relationship between the thermal conductivity coefficient and the temperature of the carbon brick intact layer based on the principle of equal radial heat flux of the blast furnace hearth and combining the thermocouple data during the blowing period;

[0069] S3, dividing the residual carbon brick of the hearth into an intact layer, a brittle layer and an iron infiltration layer along the radial direction of the hearth, recording the thickness of each region layer as L1, L2 and L3 respectively, obtaining the thermal conductivity coefficients λ2 and λ3 of the brittle layer and the iron infiltration layer, judging the size relationship between the thickness L1 of the intact layer and the insertion depth H3 of the thermocouple close to the center of the blast furnace through coupling calculation, and calculating the temperature T0 of the boundary line of the intact layer and the brittle layer and the thickness L1 of the intact layer under different conditions according to the judgment result and using the linear relationship between the thermal conductivity coefficient and the temperature obtained in step S2;

[0070] S4, taking 1150 DEG C as the critical point of the hot surface temperature of the hearth and 907 DEG C as the boundary temperature point of the brittle layer and the iron infiltration layer, and combining the real-time thermocouple temperature to calculate the thickness L2 of the brittle layer and the thickness L3 of the iron infiltration layer.

[0071] S5, repeating steps S1-S4 to calculate the lengths L1, L2 and L3 of the carbon brick intact layer, brittle layer and iron infiltration layer at different heights h of the hearth, and using an interpolation algorithm to continuously connect the discrete points to obtain a visualization diagram of the erosion degree of the carbon brick of the hearth.

[0072] Specifically, in step S1, at least three thermocouples 1, 2, 3 with different insertion depths are arranged in the hearth, the calculation starting point of the insertion depth is the starting point of the carbon brick close to the furnace shell, the insertion depths are H1, H2, H3 respectively, and H1 < H2 < H3, the temperature data of thermocouples 1, 2, 3 during the start-up period are Tf1, Tf2, Tf3 respectively, and the temperature data of thermocouples 1, 2, 3 during the non-start-up period are T1, T2, T3 respectively; the temperature data of the thermocouples is pretreated by removing the data that does not meet T3 > T2 > T1 and Tf3 > Tf2 > Tf1.

[0073] Specifically, in step S2, the solving step of the linear relationship between the thermal conductivity of the carbon brick intact layer and the temperature is:

[0074] The linear relationship between the thermal conductivity of the carbon brick intact layer and the temperature is:

[0075] λ = f (t) = λ c + b (t - tc) c )

[0076] Based on the equal heat flux between thermocouples 1, 2 and 2, 3 during the start-up period, the temperature coefficient b can be calculated by substituting the linear relationship between the thermal conductivity of the carbon brick intact layer and the temperature, and the calculation method is as follows:

[0077]

[0078] The temperature coefficient b is simplified as:

[0079] b = 2λ c [(H2-H1)(Tf3-Tf2)-(H3-H2)(Tf2-Tf1)]×[(H3-H2)(Tf2-Tf1)(Tf2+Tf1-2tc)-(H2-H1)(Tf3-Tf2)(Tf3+Tf2-2tc)] -1

[0080] The linear relationship between the thermal conductivity of the carbon brick intact layer and the temperature is obtained as:

[0081] λ = f (t) = λ c + 2λ c [(H2-H1)(Tf3-Tf2)-(H3-H2)(Tf2-Tf1)]×[(H3-H2)(Tf2-Tf1)(Tf2+Tf1-2tc)-(H2-H1)(Tf3-Tf2)(Tf3+Tf2-2tc)] -1 (t-tc)

[0082] Where λ c is the thermal conductivity of the carbon brick detected at the factory at temperature tc, and b is the temperature coefficient.

[0083] Specifically, in step S3, the coupling calculation is to calculate the heat flux difference value c between thermocouples 1, 2 and thermocouples 2, 3, and the relationship between the intact layer thickness L1 and H3 is determined by the size of the heat flux difference value c and the preset difference value a. If c is greater than the preset difference value a, it is considered that L1 < H3; if c is less than the preset difference value a, it is considered that L1 > H3; the calculation formula of the heat flux difference value c is as follows:

[0084]

[0085] Wherein, q 21 is the heat flux between thermocouples 1, 2, q 32 is the heat flux between thermocouples 2, 3.

[0086] Specifically, the calculation formulas of q 21 and q 32 are as follows:

[0087]

[0088]

[0089] Simplifying the heat flux difference value c is:

[0090]

[0091] Wherein, f(T1), f(T2), f(T3) represent the intact layer thermal conductivity at the temperatures of thermocouples 1, 2, 3.

[0092] Specifically, when L1 < H3, based on the principle that the radial heat flow intensity of the blast furnace is equal:

[0093] q 12 = q 2T0 = q 3T0

[0094] Wherein, q 2T0 is the heat flux between thermocouples 2, T0, q 3T0 is the heat flux between thermocouples 3, T0, q 2T0 and q 3T0 The calculation formulas of q 2T0 and q 3T0 are as follows:

[0095]

[0096]

[0097] Wherein, f(T0) represents the intact layer thermal conductivity at the temperature of T0, and λ2 represents the thermal conductivity of the embrittlement layer.

[0098] The calculation formula of the boundary temperature T0 between the intact layer and the embrittlement layer and the thickness L1 of the intact layer is as follows:

[0099]

[0100]

[0101] wherein λ c is the thermal conductivity of the carbon brick at the temperature tc in the factory detection, and b is the temperature coefficient.

[0102] Specifically, when L1>H3, it indicates that the residual state of the carbon brick is good, L1=H3 is taken, and the calculation formula of the boundary temperature T0 between the intact layer and the embrittlement layer and the thickness L1 of the intact layer is as follows:

[0103] T0=T3

[0104] L1=H3.

[0105] Specifically, in step S4, the temperature interval of the iron infiltration layer and the protective layer is 907-1150℃, and the calculation method of the thickness L2 of the embrittlement layer and the thickness L3 of the iron infiltration layer is as follows:

[0106] Based on the principle that the radial heat flow intensity of the blast furnace is equal:

[0107] q 12 =q 34 =q 45

[0108] wherein q 34 is the heat flux between the thermocouple 3 and 907℃, q 45 is the heat flux between 907℃ and 1150℃, and the calculation formula of q 45 is as follows:

[0109]

[0110] wherein λ3 represents the thermal conductivity of the iron infiltration layer;

[0111] The calculation formula of the iron infiltration layer L3 is as follows:

[0112]

[0113] When L1<H3, the calculation formula of q 34 is as follows:

[0114]

[0115] The calculation formula of the embrittlement layer L2 is as follows:

[0116]

[0117] When L1>H3, q 34 The calculation formula of the fragile layer L2 is as follows:

[0118]

[0119] The calculation formula of the fragile layer L2 is as follows:

[0120]

[0121] Wherein, b is the temperature coefficient.

[0122] Specifically, the steps S1-S4 are repeated, the lengths L1, L2 and L3 of the carbon brick intact layer, the fragile layer and the iron infiltration layer at different heights h of the hearth are calculated, and the lengths and height information of the boundary lines of the carbon brick intact layer-fragile layer, the fragile layer-iron infiltration layer and the iron infiltration layer-iron are marked as (L1, h), (L1+L2, h) and (L1+L2+L3, h) in turn. The discrete boundary points of each erosion layer at different heights of the carbon brick are continuous by using the Bezier interpolation algorithm, and a visualization diagram of the erosion degree of the carbon brick of the hearth is obtained.

[0123] The method for establishing the visualization of the erosion degree of the carbon brick of the hearth provided by the present application will be described below in combination with specific examples.

[0124] Example 1

[0125] The present example provides a method for establishing the visualization of the erosion degree of the carbon brick of the hearth, which specifically comprises the following steps:

[0126] S1, collect the temperature data of the hearth thermocouple arrangement position and the temperature data of the hearth thermocouple arrangement position at the start of the blast furnace and in the later production period, the insertion depths H1, H2 and H3 of the thermocouples 1, 2 and 3 are 0.20 m, 0.33 m and 0.73 m respectively. The temperatures of the thermocouples 1, 2 and 3 at the start of the blast furnace are Tf1, Tf2 and Tf3 respectively, and the temperatures of the thermocouples 1, 2 and 3 in the later production period are T1, T2 and T3 respectively. Since the thermocouple 3 is closest to the center of the hearth, the data that do not satisfy Tf3>Tf2>Tf1 and T3>T2>T1 are removed, and the temperature data of the temperature measuring area are obtained, as shown in Table 1.

[0127] Table 1 Temperature data of the thermocouples of the blast furnace at different periods

[0128] Light-off period Temperature Non-light-off period Temperature [tf1] 77.4 [T1] 131.2 [tf2] 126.8 [T2] 223.6 [tf3] 275.9 [T3] 515.7

[0129] S2, the linear mathematical model of the thermal conductivity λ of the carbon brick intact layer and the temperature t is established as follows:

[0130] λ=f(t)=λ c +b(t-t c ) (1)

[0131] wherein λ c is the thermal conductivity of the carbon brick at temperature t c is the thermal conductivity of the carbon brick at temperature t

[0132] The thermal conductivity of the carbon brick at 600℃ is 20.5 W / m℃, which is substituted into equation (1) to obtain:

[0133] λ = f(t) = 20.5 + b(t-600) (2)

[0134] Further, based on the principle of equal radial heat flux of the blast furnace hearth, the following equation is solved:

[0135]

[0136] The insertion depths H1, H2, H3 of the thermocouples 1, 2, 3 during the start-up period, the temperatures Tf1, Tf2, Tf3, and equation (2) are substituted into equation (3) to obtain the temperature coefficient b:

[0137]

[0138] Further, the temperature parameter b is substituted to obtain the relationship between the thermal conductivity of the carbon brick and the temperature:

[0139] λ = f(t) = 0.0037t + 18.3038 (5)

[0140] S3, the residual carbon brick of the hearth is divided into an intact layer, a brittle layer and an iron infiltration layer along the radial direction of the hearth, wherein the thermal conductivity λ1 of the intact layer varies with temperature, and the length of the intact layer is denoted as L1; the thermal conductivity λ2 of the brittle layer is 6.5 W / m℃, and the length is denoted as L2; the thermal conductivity λ3 of the iron infiltration layer is 8.7 W / m℃, and the length is denoted as L3; the heat flux difference value c between the thermocouples 1, 2 and the thermocouples 2, 3 is calculated, and the size relationship between the heat flux difference value c and the preset difference value 0.05 is compared to determine the relationship between the intact layer thickness L1 and H3. In this example, the heat flux difference value c is calculated as follows:

[0141]

[0142] Therefore, L1 < H3.

[0143]

[0144]

[0145] The simultaneous equations can be solved to obtain:

[0146] T0 = 489.84℃

[0147] L1 = 0.718m

[0148] S4, taking 1150℃ as the critical point of the hot face temperature of the hearth, the brittle layer near the end of the iron penetration layer deposited with harmful element zinc, taking the boiling point of zinc 907℃ as the demarcation point between the brittle layer and the iron penetration layer, so as to more accurately calculate the thickness of the brittle layer and the iron penetration layer, combining with the real-time thermocouple temperature, calculating the thickness L2 of the brittle layer and the thickness L3 of the iron penetration layer, the calculation results are as follows:

[0149]

[0150]

[0151] S5, repeating steps S1-S4, calculating the lengths L1, L2, L3 of the carbon brick intact layer, brittle layer and iron penetration layer at different heights h of the hearth, marking the length and height information of the demarcation line of the carbon brick intact layer-brittle layer, brittle layer-iron penetration layer, iron penetration layer-iron liquid, sequentially recorded as (L1, h), (L1+L2, h), (L1+L2+L3, h). Using the Bezier interpolation algorithm to continuously connect the discrete demarcation points of each erosion layer at different heights of the carbon brick, obtaining the carbon brick erosion degree visualization graph of the hearth.

[0152] The specific calculation process is shown in Table 2:

[0153]

[0154] Further, according to Table 2, the erosion degree visualization graph of the hearth can be drawn, as shown in Figure 3 From Figure 3 , the erosion degree of the carbon brick can be intuitively understood.

[0155] In summary, the application discloses a method for visualizing the erosion degree of carbon bricks in a hearth, which utilizes the position and temperature data of thermocouples during the blowing-in period, and the fact that the carbon bricks are not eroded and the actual length of the intact layer is known during the blowing-in period, so as to verify the accuracy of the formula calculation, and obtain the linear relationship between the carbon brick thermal conductivity and temperature of the intact layer, so as to ensure the use of the formula during the middle and later periods, and combine the heat flux equivalence principle to calculate the temperature of the boundary between the intact layer and the embrittlement layer, and calculate the accurate thickness of the intact layer of the carbon brick based on the boundary temperature; then, the carbon bricks are divided into the intact layer, the embrittlement layer and the iron infiltration layer along the radial direction of the hearth according to the erosion change of the carbon bricks, and based on the temperature distribution characteristics of the layers, the structure of the carbon bricks is fully considered to change from the whole intact structure to the intact layer, the embrittlement layer and the iron infiltration layer, and the boundary temperature and the thermal conductivity of the embrittlement layer and the iron infiltration layer are used to calculate the residual thickness of the carbon bricks and to establish the visualization of the erosion degree, so as to avoid the large deviation between the calculation result and the actual result of the residual thickness of the carbon bricks due to the insufficient consideration of the relationship between the actual thermal conductivity of the intact layer of the carbon bricks and the temperature change and the large change of the thermal conductivity of the carbon bricks after being eroded, so as to make the calculated residual thickness of the carbon bricks more accurate, and the visualization of the erosion degree of the carbon bricks can more directly reflect the erosion condition of the carbon bricks. The calculation method of the application is simple, the data is easy to obtain, and the operability is strong, and based on the relationship between the thermal conductivity of the intact layer of the residual carbon bricks and the temperature change and the structure change and the corresponding change of the thermal conductivity of the carbon bricks after being eroded, the thickness of the carbon bricks is calculated in different regions, so that the calculation result can more accurately reflect the erosion degree of the carbon bricks, so as to guide the measures beneficial to the safety of the hearth and reduce the risk of the hearth burning through, provide a scientific theoretical basis for improving the service life of the blast furnace, and have a wide application prospect.

[0156] The above examples are only used to illustrate the technical solutions of the application but not limit the application. Although the application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the application can be modified or replaced equivalently without departing from the spirit and scope of the application.

Claims

1. A method of establishing a visualization of the degree of erosion of a hearth carbon brick, characterized in that The method comprises the following steps: S1, collecting the temperature data of the hot electrode arrangement position of the furnace hearth during the blowing period and the non-blowing period of the blast furnace, recording the temperature of the hot electrode during the blowing period as Tf, recording the insertion depth of the hot electrode close to the center of the blast furnace as H3, and preprocessing the temperature data of the hot electrode during the blowing period and the non-blowing period; S2, based on the principle of equal radial heat flux of the blast furnace hearth and combined with the hot electrode data during the blowing period, a linear relationship between the thermal conductivity and the temperature of the carbon brick intact layer is obtained; S3, the residual carbon brick of the furnace hearth is divided into an intact layer, a brittle layer and a iron infiltration layer along the radial direction of the furnace hearth, the thicknesses of the layers are respectively recorded as L1, L2 and L3, the thermal conductivities λ2 and λ3 of the brittle layer and the iron infiltration layer are obtained, the relationship between the thickness L1 of the intact layer and the insertion depth H3 of the hot electrode close to the center of the blast furnace is judged by coupling calculation, and the boundary temperature T0 of the intact layer and the brittle layer and the thickness L1 of the intact layer are calculated under different conditions according to the judgment result and the linear relationship between the thermal conductivity and the temperature in step S2; S4, taking 1150℃ as the critical point of the hot surface temperature of the furnace hearth and 907℃ as the boundary temperature point of the brittle layer and the iron infiltration layer, the thicknesses L2 and L3 of the brittle layer and the iron infiltration layer are calculated combined with the real-time temperature of the hot electrode; S5, repeating steps S1-S4, the lengths L1, L2 and L3 of the carbon brick intact layer, the brittle layer and the iron infiltration layer at different heights h of the furnace hearth are calculated, the discrete points are continuous by using the interpolation algorithm, and a visualization diagram of the erosion degree of the carbon brick of the furnace hearth is obtained; In step S1, at least three hot electrodes 1, 2 and 3 with different insertion depths are arranged in the furnace hearth, the calculation starting point of the insertion depth is the starting point of the carbon brick close to the furnace shell, the insertion depths are H1, H2 and H3, and H1 In step S2, the linear relationship between the thermal conductivity and the temperature of the carbon brick intact layer is: λ = f(t) = λ c + b(t - t c ) b = 2λ c [(H2-H1)(Tf3-Tf2)-(H3-H2)(Tf2-Tf1)] x [(H3-H2)(Tf2-Tf1)(Tf2+Tf1-2tc)-(H2-H1)(Tf3-Tf2)(Tf3+Tf2-2tc)] -1 where λ c is the thermal conductivity at temperature t c b is the temperature coefficient.

2. The method of claim 1, wherein: In step S3, the coupling calculation is to calculate the heat flux difference value c between the hot electrodes 1 and 2 and the hot electrodes 2 and 3 to judge the relationship between the thickness L1 of the intact layer and H3.

3. The method of claim 2, wherein: If c is greater than a preset difference value a, it is considered that L1 where q 21 is the heat flux between thermocouples 1, 2, q 32 is the heat flux between thermocouples 2, 3.

4. The method of claim 3, wherein: q 21 With q 32 The calculation formula is as follows: When L1 5. The method of claim 4, wherein: ​ wherein Ktcis the thermal conductivity of the carbon brick at the temperature tc, and b is the temperature coefficient.

6. The method of claim 4, wherein: When L1>H3, it indicates that the carbon brick residual state is good, L1=H3 is taken, and the calculation formula of the perfect layer and the brittle layer boundary temperature T0 and the perfect layer thickness L1 is as follows: 。 7. The method of claim 1, wherein: In step S4, the calculation method of the brittle layer thickness L2 and the iron permeation layer thickness L3 is as follows: Based on the principle of equal radial heat flow intensity of the blast furnace: where q 34 is the heat flux between 3 and 907 °C for thermocouple 1, q 45 is the heat flux between 907 and 1150 °C for thermocouple 1, and q 45 is calculated as follows: wherein represents the thermal conductivity of the iron penetration layer; The calculation formula of the iron permeation layer L3 is as follows: when L1 34 The calculation formula is as follows: The calculation formula of the brittle layer L2 is as follows: when L1> H3, q 34 The calculation formula is as follows: The calculation formula of the brittle layer L2 is as follows: Wherein, b is the temperature coefficient.

8. The method of claim 1, wherein: Repeat steps S1-S4 to calculate the lengths L1, L2 and L3 of the carbon brick perfect layer, brittle layer and iron permeation layer at different heights h of the furnace hearth, mark the length and height information of the carbon brick perfect layer-brittle layer, brittle layer-iron permeation layer and iron permeation layer-iron layer boundaries, and sequentially mark as (L1, h), (L1+L2, h) and (L1+L2+L3, h). The discrete boundary points of each erosion layer at different heights of the carbon brick are continuous by using the Bezier interpolation algorithm, and the carbon brick erosion degree visualization diagram of the furnace hearth is obtained.

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