Method for accurately calculating hard press-in material quantity of cooling plate area

Abstract

This invention belongs to the field of metallurgical engineering technology, and particularly relates to a method for accurately quantifying and verifying the amount of hard material pressed into the cooling plate area. The specific steps are as follows: S1: Basic parameter acquisition and preprocessing: 1. Determination of basic parameters; 2. Data acquisition and processing; S2: Calculation of hard material pressed-in amount: 1. Calculation of average heat flux intensity in the area; 2. Calculation of the remaining thickness from the hot surface of the graphite brick to the thermocouple point; 3. Verification and compensation of the erosion thickness of the graphite brick; 4. Calculation of geometric parameters of the erosion area; 5. Calculation of erosion volume; 6. Calculation of theoretical pressed-in amount; S3: Extended verification application: 1. Calculation of slag-iron solidified layer thickness; 2. Calculation of actual hard material pressed-in thickness; S4: Establishment or embedding of system model. This method, throughout the entire life cycle of the blast furnace, regardless of whether the thermocouple is burned out or data is missing, achieves accurate quantification of the amount of material pressed into the cooling plate area, online dynamic monitoring of slag-iron layer fluctuations, and verification of furnace lining thickness changes before and after hard material pressing-in.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical engineering technology, and in particular relates to a method for accurately calculating the amount of hard material pressed into the cooling plate area. Background Technology

[0002] As a critical cooling component of the blast furnace, the erosion state of the graphite bricks surrounding the cooling plate directly affects the operational safety and service life of the blast furnace. To compensate for graphite brick erosion, hard feedstock needs to be pressed into the drilled holes in the cooling plate. Currently, the industry's assessment of the amount of hard feedstock to be pressed in largely relies on operator experience or is based solely on simple estimations of furnace dimensions, without considering factors such as differences in heat load in different areas, the actual degree of erosion of the graphite bricks, and the dynamic changes in the slag-iron solidification layer. This leads to significant deviations in the calculation of the feedstock amount: either insufficient feedstock fails to effectively fill the eroded gaps, leaving the cooling plate still at risk of overheating and damage; or excessive feedstock results in material waste and increased costs, and may even cause secondary damage to the graphite bricks due to overfilling. Furthermore, existing technology lacks real-time measurement methods for the thickness of the slag-iron solidification layer at the hot front of the cooling plate, and cannot accurately verify the actual effective thickness of the hard feedstock after pressing. This further affects the scientific and targeted nature of blast furnace maintenance, hindering the long-term stable and efficient operation of the blast furnace. Summary of the Invention

[0003] The purpose of this invention is to provide a precise method for calculating the amount of hard material pressed into the cooling plate area, which solves the problem that existing operations do not take into account factors such as differences in heat load in different areas, the actual degree of erosion of graphite bricks, and dynamic changes in the slag and iron solidification layer, resulting in large deviations in the calculation of the pressing amount and the inability to accurately verify the actual effective thickness of the hard material after pressing.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A method for accurately calculating the amount of rigid press-in material in the cooling plate area, the specific steps of which are as follows: S1: Basic parameter acquisition and preprocessing 1. Determining basic parameters 2. Data Acquisition and Processing S2: Hard material feed rate calculation 1. Calculation of regional average heat flux intensity Based on the definition of heat flux intensity, using the formula q i =Q i / A i Calculate the current average heat flux intensity for each region, where Q i Let q be the instantaneous average heat load corresponding to each region. i This represents the average heat flux intensity under this heat load; 2. Calculation of erosion thickness of graphite bricks 3. Verification and replacement of erosion thickness in graphite bricks 4. Calculation of geometric parameters of eroded area 5. Calculation of erosion volume 6. Calculation of theoretical pressure By combining the bulk density of the hard indenter and using the conversion relationship between mass and volume, the theoretical hard indentation amount Z in each region can be obtained. i (Z) i =V i (×bulk density); S3: Extended Validation 1. Calculation of slag-iron solidified layer thickness 2. Calculation of actual hard indentation thickness S4: Establish or embed a system model Establish a large historical heat flux intensity database to continuously store data such as heat load, heat flux intensity, thermocouple temperature, and graphite brick erosion status under different operating conditions in various regions, for q m T m The database provides a data foundation for screening and correlation calculation of various parameters, and supports real-time updates and dynamic optimization. It can directly establish a hard indentation model under cooling plate erosion or embed it into an existing erosion model system. Input data can be used to directly calculate the amount of hard indentation material, which enhances the practicality and adaptability of the technical solution and facilitates its application in industrial scenarios.

[0005] Preferably, the specific content of determining the basic parameter 1 in S1 is as follows: Based on the blast furnace type, determine the projected lateral area A of the gas heat flow in each cooling plate region. i By approximating the cooling plate area as a frustum, and through the design of furnace parameters, calculations were derived to determine the depth of the cooling plate inserted into the furnace from the inside of the furnace shell, the depth of the thermocouple point inserted into the furnace from the inside of the furnace shell, the bulk density of the hard feed material, the original installation dimensions of the cooling plates, and the distance H between each layer of cooling plates and the corresponding pressing part. i .

[0006] Preferably, the specific content of data acquisition and processing in step S1 is as follows: Real-time data collection of the historical maximum total heat load Q for each region m Under this operating condition, the highest temperature T of the thermocouple in the cooling plate area is... m The maximum heat flux intensity q corresponding to the highest heat load in the synchronous calculation and collection of operational data is calculated. m .

[0007] Preferably, the specific details of calculating the erosion thickness of the two graphite bricks in S2 are as follows: Based on a large database of historical heat flux intensities, q is extracted under the highest heat load condition. m With T m Using the Fourier formula q=λ×(T2-T1) / L, the residual thickness L of the graphite brick at the slag-iron solidification layer from the dipole point to 1150℃ can be calculated. iWhere λ is the thermal conductivity coefficient of graphite brick, T2 is the slag-iron solidification temperature, and T1 is the thermocouple temperature at maximum heat flow intensity, substituting into the formula and transforming it, we get Lᵢ=λ×(T2-T1) / q, and the graphite brick erosion thickness Sᵢ=the depth of the cooling plate inserted into the furnace from the inside of the furnace shell - the depth of the thermocouple point inserted into the furnace from the inside of the furnace shell - the thermocouple point to the slag-iron solidification layer at 1150℃, where Lᵢ is the residual thickness of graphite brick.

[0008] Preferably, the specific details of verifying and filling in the erosion thickness of the three graphite bricks in step S2 are as follows: The annual thickness measurement data of the 5 layers and 8 positions of wear-resistant rods set in the cooling plate area is used to obtain the erosion thickness of the graphite bricks. The residual thickness of the graphite bricks is calculated first according to the formula: graphite brick residual thickness = average thickness of wear-resistant rods - length from wear-resistant rod flange to the inner side of the furnace shell - thickness of the refractory material poured into the furnace shell. The erosion thickness of the graphite bricks is calculated as: depth of the cooling plate inserted into the furnace from the inner side of the furnace shell - residual thickness of the graphite bricks. The obtained graphite brick erosion thickness is compared with the graphite brick erosion thickness calculated in S2 to verify the results. The verification standard is: the error is less than 50mm. This is to verify the accuracy of the calculated erosion thickness and to replace the thermally calculated erosion thickness with the wear-resistant rod erosion thickness when the thermocouple is burned out and cannot display the temperature in the later stage of the furnace operation, thus filling the missing data and achieving full-range applicability throughout the entire life cycle.

[0009] Preferably, the specific details of calculating the geometric parameters of the erosion region in step S2 are as follows: A physical model of the erosion space was established by designing the furnace shape and the original dimensions of the cooling plate. The cooling plate was approximated as a parallel trapezoid. When the width of the front and rear ends of the cooling plate was constant, the corresponding erosion thickness of the graphite brick was S. i At that time, the chord length and width W of the hot surface of the cooling plate were calculated using the approximate triangle principle. i .

[0010] Preferably, the specific details of the erosion volume calculation in step S2 are as follows: Using the geometric volume formula V i =W i ×2H i ×S i Calculate the erosion volume V of the graphite brick at the drilled hole of the cooling plate in each region. i W i 2H represents the chord length and width of the hot surface of the cooling plate. i This corresponds to the spacing between the upper and lower cooling plates.

[0011] Preferably, the specific details of calculating the thickness of the slag-iron solidified layer in step S3 are as follows: Based on the heat flux intensity database, the residual thickness L of the graphite brick has been obtained. i and the current average heat flux intensity q in each region iA correlation model between heat flux intensity and solidified layer thickness was established using Fourier's formula to calculate the thickness X of the slag-iron solidified layer at the front of the cooling plate under arbitrary instantaneous conditions. i .

[0012] Preferably, the specific details of calculating the actual hard material pressing thickness in step S3 are as follows: The heat flux intensity (q) of the corresponding regions before and after the hard material was pressed in was collected respectively. i front, q i (after) and thermocouple temperature measurement data (T) i Front, T i Afterwards, the thickness of the slag-iron solidified layer after pressing is calculated using the logic for calculating the amount of hard material pressed in step S2. i Take max(X2) i X2 i -X1 i The effective thickness Y of the actual hard indenter material i , where X2 i -X1 i It reflects the incremental increase in the thickness of the solidified layer due to the pressurized material, ensuring that the calculation results cover the effective thickness range under different working conditions.

[0013] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: (1) Accuracy: Breaking through the limitations of traditional empirical estimation, through the coupled calculation of heat flow intensity, temperature and geometric parameters, the quantitative analysis of hard pressing amount, graphite brick erosion volume and condensed slag iron layer thickness is realized, the error is significantly reduced, and accurate data support is provided for pressing operation; (2) Real-time: Dynamic calculations can be performed based on real-time monitoring data of the blast furnace to promptly grasp the erosion status of graphite bricks and the changes in the solidified slag and iron layer, thereby realizing dynamic optimization of maintenance decisions; (3) Comprehensiveness: Not only can the amount of injection be quantified, but the thickness of the condensed slag iron layer and the actual injection effect can also be monitored simultaneously, forming a complete technical management closed loop of "erosion status under dynamic temperature field - erosion assessment - injection quantification - effect verification", which improves the systematic nature of maintenance; (4) Versatility: Applicable to the cooling plate area of ​​blast furnaces with different furnace designs, only requiring adjustment of A corresponding to the furnace design. i H i Basic parameters, strong adaptability; (5) Throughout the entire life cycle of the blast furnace, regardless of whether the thermocouple is burned out or the data is missing, this method can accurately quantify the material pressed into the cooling plate area, monitor the fluctuation of the slag and iron layer online, and verify the change of furnace lining thickness before and after the hard material is pressed in. It has the characteristics of full dimension, full coverage and full closed loop. Detailed Implementation

[0014] The technical solution of the present invention will be described in detail below with reference to the embodiments.

[0015] The method of this invention was used to calculate the amount of hard material pressed into the cooling plates during the scheduled maintenance shutdowns of Taiyuan Iron & Steel Group's No. 6 blast furnace in September and November. Taking the 21st to 29th layer area of ​​the cooling plates as an example, the specific steps are as follows: 1. Determination of basic parameters: Calculation of projected lateral area of ​​segmented cooling plate region: The cooling plate region is divided into 6 regions according to the designed furnace type, of which regions 21-29A are... i =127.47m², the distance H between each cooling plate and the corresponding pressing part i The length is 0.312m. The original dimensions of the cooling plate are: rear width 689mm, front width 647mm, and length 500mm. That is, the depth to which the cooling plate is inserted into the furnace from the inside of the furnace shell is 500mm. The bulk density of the hard pressed material is 2.1g / cm³. 3 The electrode point is inserted into the furnace to a depth of 0.2 mm from the inside of the furnace shell. 2. Data Acquisition: The total heat load of each area is collected through the blast furnace thermal monitoring system, with the average Q of floors 21-29 over a certain period being recorded. i =1621*10*MJ / h, corresponding to the thermocouple temperature T in the region. i =206℃; 3. Calculation of current instantaneous average heat flux intensity: q i =Q i / A i =1621*10*MJ / h / 127.47m 2 =35322W / m 2 ; 4. Historical Data Retrieval: Extract the historical highest heat load conditions for a specific region from the database, q for zones 21-29. m =468334W / m 2 Corresponding to T m =1083℃; 5. Calculation of etch thickness of graphite brick: According to Fourier's formula q=λ×(T2-T1) / L, where the thermal conductivity of graphite brick λ=130W / (m·K), T2=1150℃ (slag-iron solidification temperature), T1=T m =1083℃, substituting this into the equation, we obtain the residual thickness L of the graphite brick at the slag-iron solidification layer from the thermocouple point to 1150℃. i =λ×(T2-T1) / q=0.0186m, then the erosion thickness S of the graphite brick i =The depth of the cooling plate inserted into the furnace from the inside of the furnace shell - the depth of the thermocouple point inserted into the furnace from the inside of the furnace shell - the residual thickness of the graphite brick at the slag-iron solidification layer at 1150℃ Lᵢ=0.5-0.2-0.0186=0.2814m; 6. Verification of Actual Thickness Measurement of Wear-Resistant Rods: The thickness of wear-resistant rods in the cooling plate area is measured annually. During the scheduled maintenance shutdown on March 28, 2025, the average thickness of wear-resistant rods in zones 21-29 was 516mm. Therefore, the length from the wear-resistant rod flange to the inner side of the furnace shell is 210mm. There is 50mm of castable material inside the furnace shell. Thus, the residual thickness of the graphite brick = average thickness of wear-resistant rods - length from the wear-resistant rod flange to the inner side of the furnace shell - thickness of castable material inside the furnace shell = 516 - 210 - 50 = 256mm. The erosion thickness = depth of the cooling plate inserted into the furnace from the inner side of the furnace shell - residual thickness of the graphite brick = 500mm - 256mm = 244mm. Compared with the theoretical erosion thickness of 281mm calculated by thermal engineering, the difference is 37mm, which is less than 50mm, verifying the accuracy of the calculation. 7. The chord width W of the eroded region's thermal surface i Calculation: Coupled with the furnace lining erosion and the cooling plate embedded in the furnace shape, a physical model of the erosion space is established. The cooling plate is approximated as a parallel trapezoid, and the corresponding erosion thickness S can be calculated using the approximate triangle principle. i Cooling plate chord length and width W i =0.671m; 8. Erosion volume calculation: V i =W i ×2H i ×S i =0.671m×2×0.312m×(0.5-0.2-0.0186)m=0.118m³; 9. Calculation of theoretical indentation: Z i= V i × Bulk density = 0.118 m³ × 2.1 kg / m³ = 247.8 kg; 10. Extended Verification: For a certain location in zones 21-29, the residual thickness L of the graphite brick at the slag-iron solidification layer at 1150℃ from the electric dipole point. i =0.0186m, q after pressing i 1 = 20178 W / m², corresponding to the thermocouple temperature T in the region. i =1=76℃. Using the Fourier formula, the residual graphite brick hot surface temperature T2=T1+L*q / λ, so T2=76+0.0186*20178 / 130=78.9℃. Again, using the Fourier formula, the slag-iron solidification layer thickness X1 is calculated. i =(T2-T1)*λ / q i 1. The solidification temperature of slag and iron, T2, is 1150℃, and the thermal conductivity of the slag and iron shell, λ, is 3. The thicknesses X1 of the pressed-in layer and the solidified slag and iron layer can be further calculated. i = (1150-78.9)*3 / 20178=159.2 mm, which is the thickness of the pressed-in layer and the slag-iron solidification layer x1. i =0.159m; q was collected before pressing.i 2 = 35322 W / m², T i =206℃, and similarly, the relevant data before the artificial external lining is pressed in can be obtained, and X2 can be calculated. i =0.079m, Y i =max(159mm, 159mm-79mm)=80mm, so the actual thickness of the pressed material is at least 80mm (when the solidified slag and iron layer is completely present) and at most 159mm (when the solidified slag and iron layer is completely detached).

[0016] Using this method, the amount of hard cement pressed into a single hole in Taiyuan Iron & Steel Group's No. 6 blast furnace has been reduced from 450-500 kg to 300-350 kg, significantly reducing heat load fluctuations. This not only saves materials and reduces grouting time, but also helps to standardize the furnace shape and accelerates the stabilization of airflow after re-winding.

[0017] Each single-hole hard material injection reduces the average weight by 150 kg. Based on the current 181 holes, this directly reduces the hard material injection weight by 27.2 tons, saving 27.2 * (6800 + 3000) / 10000 = 266,000 yuan in material and construction costs. Currently, the hard material injection cycle is once every two months, resulting in an annual cost reduction of 266,000 * 6 = 1,596,000 yuan. Precise control of the hard material injection weight also leads to a more regular furnace shape, which is more conducive to stable airflow, and the heat load is reduced from the previous 1 The heat load was reduced from 5000*10Mj / h to the current 12000*10Mj / h, resulting in a daily heat load reduction of 24*3000*10Mj / h=960000Mj and a fuel reduction of 73.5t. Based on a current fuel cost of 1300 yuan and an airflow regularization cycle of 7 days, the annual fuel cost reduction is 73.5*1300*7*6=4.013 million yuan. Combining the above two factors, the total cost reduction is 5.609 million yuan, demonstrating significant economic benefits.

[0018] This method transforms the blast furnace temperature field into a three-dimensional spatial field, simultaneously analyzing and calculating the thickness of the slag-iron solidified layer at the front of the blast furnace cooling plate, providing data support for judging the gas flow distribution in the furnace and optimizing the cooling regime; it constructs a hard material infeed effect verification system to accurately evaluate the actual effective thickness of the hard material infeed, verify the infeed construction effect, and provide a basis for subsequent maintenance plan adjustments; and it establishes a standardized "erosion diagnosis - infeed amount calculation - effect verification" calculation process to reduce human error.

Claims

1. A method for accurately calculating the amount of hard material pressed into the cooling plate area, characterized in that, The specific steps are as follows: S1: Basic parameter acquisition and preprocessing 1. Determining basic parameters 2. Data Acquisition and Processing S2: Hard material feed rate calculation 1. Calculation of regional average heat flux intensity Based on the definition of heat flux intensity, using the formula q i =Q i / A i Calculate the current average heat flux intensity for each region, where Q i Let q be the instantaneous average heat load corresponding to each region. i This represents the average heat flux intensity under this heat load; 2. Calculation of erosion thickness of graphite bricks 3. Verification and replacement of erosion thickness in graphite bricks 4. Calculation of geometric parameters of eroded area 5. Calculation of erosion volume 6. Calculation of theoretical pressure By combining the bulk density of the hard indenter and using the conversion relationship between mass and volume, the theoretical hard indentation amount Z in each region can be obtained. i (Z) i =V i (×bulk density); S3: Extended Validation 1. Calculation of slag-iron solidified layer thickness 2. Calculation of actual hard indentation thickness S4: Establish or embed a system model Establish a large historical heat flux intensity database to continuously store data such as heat load, heat flux intensity, thermocouple temperature, and graphite brick erosion status under different operating conditions in various regions, for q m T m The database provides a data foundation for screening and correlation calculation of various parameters, and supports real-time updates and dynamic optimization; it can directly establish a hard indentation model under cooling plate erosion or embed it into an existing erosion model system, and directly calculate the amount of hard indentation material from the input data.

2. The method for accurately calculating the amount of hard material pressed into the cooling plate area according to claim 1, characterized in that, The specific details of the basic parameter 1 in S1 are as follows: Based on the blast furnace type, determine the projected lateral area A of the gas heat flow in each cooling plate region. i By approximating the cooling plate area as a frustum, and through the design of furnace parameters, calculations were derived to determine the depth of the cooling plate inserted into the furnace from the inside of the furnace shell, the depth of the thermocouple point inserted into the furnace from the inside of the furnace shell, the bulk density of the hard feed material, the original installation dimensions of the cooling plates, and the distance H between each layer of cooling plates and the corresponding pressing part. i .

3. The method for accurately calculating the amount of hard material pressed into the cooling plate area according to claim 2, characterized in that, The specific details of data acquisition and processing in S1 are as follows: Real-time data collection of the historical maximum total heat load Q for each region m Under this operating condition, the highest temperature T of the thermocouple in the cooling plate area is... m The maximum heat flux intensity q corresponding to the highest heat load in the synchronous calculation and collection of operational data is calculated. m .

4. The method for accurately calculating the amount of hard material pressed into the cooling plate area according to claim 1, characterized in that, The specific details of calculating the erosion thickness of graphite brick 2 in S2 are as follows: Based on a large database of historical heat flux intensities, q is extracted under the highest heat load condition. m With T m Using the Fourier formula (q=λ×(T2-T1) / L), the residual thickness L of the graphite brick at the slag-iron solidification layer from the dipole point to 1150℃ can be calculated. i Where λ is the thermal conductivity coefficient of the graphite brick, T2 is the slag-iron solidification temperature, and T1 is the thermocouple temperature at maximum heat flux. Substituting these values ​​into the formula, we get Lᵢ=λ×(T2-T1) / q, where S is the erosion thickness of the graphite brick. i =Depth of cooling plate insertion into the furnace from the inside of the furnace shell - Residual thickness of graphite brick at the slag-iron solidification layer at 1150℃ (from the depth of insertion into the furnace shell from the inside of the furnace shell - from the thermocouple point) i .

5. The method for accurately calculating the amount of hard material pressed into the cooling plate area according to claim 4, characterized in that, The specific details of verifying and filling in the erosion thickness of the graphite bricks in step S2 are as follows: The annual thickness measurement data of the 5 layers and 8 positions of the wear-resistant rods set in the cooling plate area is used to obtain the erosion thickness of the graphite bricks. First, the residual thickness of the graphite bricks is calculated according to the formula: graphite brick residual thickness = average thickness of wear-resistant rods - length from the wear-resistant rod flange to the inner side of the furnace shell - thickness of the refractory material poured into the furnace shell. The erosion thickness of the graphite bricks is calculated as: depth of the cooling plate inserted into the furnace from the inner side of the furnace shell - residual thickness of the graphite bricks. The obtained erosion thickness of the graphite bricks is compared with the erosion thickness of the graphite bricks calculated in step 2 for verification. The verification standard is: error less than 50mm.

6. The method for accurately calculating the amount of hard material pressed into the cooling plate area according to claim 5, characterized in that, The specific details of calculating the geometric parameters of the erosion region in step S2 are as follows: A physical model of the erosion space was established by designing the furnace shape and the original dimensions of the cooling plate. The cooling plate was approximated as a parallel trapezoid. When the width of the front and rear ends of the cooling plate was constant, the corresponding erosion thickness of the graphite brick was S. i At that time, the chord length and width W of the hot surface of the cooling plate were calculated using the approximate triangle principle. i .

7. The method for accurately calculating the amount of hard material pressed into the cooling plate area according to claim 6, characterized in that, The specific details of the erosion volume calculation in step S2 are as follows: Using the geometric volume formula V i =W i ×2H i ×S i Calculate the erosion volume V of the graphite brick at the drilled hole of the cooling plate in each region. i W i 2H represents the chord length and width of the hot surface of the cooling plate. i This corresponds to the spacing between the upper and lower cooling plates.

8. The method for accurately calculating the amount of hard material pressed into the cooling plate area according to claim 1, characterized in that, The specific details of calculating the thickness of the slag-iron solidified layer in step S3 are as follows: Based on the heat flux intensity database, the residual thickness L of the graphite brick has been obtained. i and the current average heat flux intensity q in each region i A correlation model between heat flux intensity and solidified layer thickness was established using Fourier's formula to calculate the thickness X of the slag-iron solidified layer at the front of the cooling plate under arbitrary instantaneous conditions. i .

9. The method for accurately calculating the amount of hard material pressed into the cooling plate area according to claim 8, characterized in that, The specific details of calculating the actual hard material pressing thickness in step S3 are as follows: The heat flux intensity (q) of the corresponding regions before and after the hard material was pressed in was collected respectively. i front, q i (after) and thermocouple temperature measurement data (T) i Front, T i Afterwards, the thickness of the pressed layer and the slag-iron solidified layer after pressing are calculated using the hard material pressing amount calculation logic in step S2. i Take max(X2) i , X2 i -X1 i The effective thickness Y of the actual hard indenter material i , where X2 i -X1 i It reflects the incremental increase in the thickness of the solidified layer due to the pressurized material, ensuring that the calculation results cover the effective thickness range under different working conditions.