Method and system for judging dead manhole state of furnace hearth based on static pressure of furnace shaft

Abstract

The application discloses a method and system for judging the dead material column state of a hearth based on static pressure of a furnace shaft, which comprises presetting multiple static pressure test points at the lower part of the furnace shaft and continuously detecting multiple static pressure test values; calculating the difference between the blast pressure and the multiple static pressure test values to obtain a static pressure change value; calculating the pressure fluctuation range of each static pressure test point within a preset time according to the static pressure change value; when the pressure fluctuation range exceeds the preset normal range to reach a preset threshold value; judging that the air permeability of the dead material column exceeds the expectation. The method avoids the increase of the coke crushing amount in the dead material column, the deterioration of the liquid permeability of the dead material column, the deterioration of the hearth state, and abnormal conditions such as material sliding, pipeline and furnace type bonding. The method maintains the stability of the dead material column state and maintains the blast furnace in a stable state for a long time.

Description

Technical Field

[0001] This invention relates to the field of blast furnace condition technology, and in particular to a method and system for determining the state of the dead material column in the hearth based on the static pressure of the furnace body. Background Technology

[0002] The dead charge column in the blast furnace hearth is located inside the furnace, and its state is difficult to observe directly. However, its state directly affects the stability and smooth operation of the blast furnace. Currently, measures such as coke quality management, temperature change assessment, and adjustments between the upper and lower parts of the blast furnace are generally used to evaluate the dead charge column. These measures aim to control the dead charge column by improving coke quality, adjusting hearth temperature, and regulating the blast and charging systems. A common problem with these measures is their long control cycle, typically taking 3-5 hours to take effect. Blast furnace operation is a massive system that changes rapidly; fluctuations in blast pressure, blast volume, pressure differential, and charge distribution within 1-3 seconds can cause serious problems if not handled promptly. Therefore, there is an urgent need for a method and system based on the static pressure of the furnace body to determine the state of the dead charge column in the hearth, and to evaluate blast furnace operation and the state of the dead charge column. Summary of the Invention

[0003] This application provides a method and system for judging the state of the dead material column in the hearth based on the static pressure of the furnace body. It at least partially solves the technical problem in the prior art that the hearth state deteriorates due to the long control cycle of the blast furnace and the untimely handling of the blast furnace operation system. It achieves the technical effect of timely judging the state of the dead material column and maintaining the stability of the dead material column state.

[0004] Firstly, to solve the above-mentioned technical problems, embodiments of the present invention provide the following technical solutions:

[0005] A method for determining the state of the dead stock in the hearth based on the static pressure of the furnace body includes:

[0006] Multiple static pressure test points are preset at the lower part of the furnace body, and multiple static pressure test values ​​are continuously obtained.

[0007] Calculate the difference between the blower pressure and multiple static pressure test values ​​mentioned above to obtain the static pressure change value;

[0008] Based on the above static pressure change values, calculate the pressure fluctuation range of each of the above static pressure test points within a preset time period;

[0009] When the pressure fluctuation range exceeds the preset normal range and reaches the preset threshold, it is determined that the air permeability of the dead material column exceeds expectations.

[0010] Optionally, after determining that the air permeability of the aforementioned dead material column exceeds expectations, the above method further includes:

[0011] The blast furnace operating parameters are adjusted until the pressure fluctuation range meets the preset conditions.

[0012] Optionally, the above steps for correcting blast furnace operating parameters also include:

[0013] When the quality of coke deteriorates but the thermal strength of the coke does not exceed a preset threshold, the coke load is adjusted by controlling the amount of deteriorated coke used.

[0014] Optionally, the above steps for adjusting the coke load by controlling the amount of degraded coke used further include:

[0015] Control the blast furnace temperature and ensure that the silicon content is greater than or equal to a preset threshold.

[0016] Optionally, the above-mentioned step of adjusting the coke load by controlling the amount of degraded coke used further includes:

[0017] Adjust the blast furnace basicity to ensure that the sulfur content in the molten iron is less than the preset threshold.

[0018] Optionally, the above steps for adjusting the coke load by controlling the amount of degraded coke used further include:

[0019] Adjust the amount of ore used in the blast furnace and the angle of the charge distribution until an M-shaped charge surface is formed on the top of the furnace.

[0020] Optionally, the above steps for adjusting the coke load by controlling the amount of degraded coke used further include:

[0021] Within the preset total center focus ring number range, adjust the center focus amount.

[0022] Optionally, the above steps for adjusting the coke load by controlling the amount of degraded coke used further include:

[0023] Adjust the blast furnace air intake area according to the required blast kinetic energy and wind speed.

[0024] Optionally, before calculating the difference between the blower pressure and the multiple static pressure test values, the method further includes:

[0025] Based on the preset normal air volume and the blast furnace required blast kinetic energy, the coefficient between the normal air volume and the required air volume is determined to obtain the reference range of the required air volume.

[0026] Calculate the blower pressure based on the above benchmark range.

[0027] Secondly, a system for determining the state of the dead stock in the furnace hearth based on the static pressure of the furnace body is provided, the system comprising:

[0028] The static pressure detection module is used to preset multiple static pressure test points at the bottom of the furnace body and continuously detect and obtain multiple static pressure test values.

[0029] The static pressure change calculation module is used to calculate the difference between the blower pressure and multiple static pressure test values ​​mentioned above, and obtain the static pressure change value.

[0030] The fluctuation range calculation module is used to calculate the pressure fluctuation range of each of the above static pressure test points within a preset time based on the above static pressure change value.

[0031] The result module is used to determine that the air permeability of the dead material column exceeds expectations when the pressure fluctuation range exceeds the preset normal range and reaches the preset threshold.

[0032] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0033] Firstly, by utilizing the static pressure changes at points 8-12 in the lowest section of the blast furnace, corresponding to the differences in airflow distribution between the center and the edges, the state of the deadweight column is characterized by the change in the pressure difference ΔPi between the blast pressure and the static pressure detected in the lower part of the furnace. This allows for timely assessment of the deadweight column state and its impact on blast furnace operation. Appropriate measures are then taken to maintain the stability of the deadweight column state, keeping the blast furnace in a stable state for extended periods. This prevents an increase in coke breakage within the deadweight column, deterioration of its permeability, and worsening of the hearth condition, leading to abnormal conditions such as material slippage, pipe adhesion, and furnace mold sticking, which could cause significant losses to blast furnace production. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 A flowchart illustrating a method for determining the state of the dead material column in the hearth based on the static pressure of the furnace body, as provided in this application;

[0036] Figure 2 A schematic diagram showing the location of the static pressure detection points of the dead material column inside the blast furnace provided in this application;

[0037] Figure 3 A flowchart illustrating the steps for adjusting coke load to control the amount of degraded coke used, as provided in this application.

[0038] Figure 4 This application provides a schematic diagram of a system for determining the state of the dead material column in the furnace hearth based on the static pressure of the furnace body. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0041] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0042] It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solutions of this application, rather than limitations on the technical solutions of this application. Unless otherwise specified, the embodiments of the present application and the technical features in the embodiments can be combined with each other.

[0043] This application provides a method and system for judging the state of the dead material column in the hearth based on the static pressure of the furnace body. This improves the technical problem in the prior art where the long control cycle of the blast furnace and the instantaneous changes in the blast furnace operation system lead to untimely handling of the blast furnace and the deterioration of the hearth state. It achieves the technical effect of timely evaluation of the state of the dead material column and maintaining the stability of the dead material column state.

[0044] The technical solution of this application embodiment is to solve the above-mentioned technical problems, and the general idea is as follows:

[0045] To address the aforementioned technical issues, the change in static pressure at points 8-12 in the lowest section of the blast furnace corresponds to the difference in airflow distribution between the center and the edge. The pressure difference ΔP between the blast pressure and the static pressure at the bottom of the furnace is then measured. i The changes in the deadweight column are used to characterize its state, allowing for timely assessment and evaluation of its impact on blast furnace operation. Appropriate measures are then taken to maintain the stability of the deadweight column, ensuring the blast furnace remains in a stable state for extended periods. This prevents an increase in coke breakage within the deadweight column, deterioration of its permeability, and subsequent worsening of the hearth condition, leading to abnormal situations such as material slippage, pipe adhesion, and furnace lining sticking, which could cause significant losses to blast furnace production.

[0046] In the embodiments of this application, the following are provided: Figure 1The method shown is for determining the state of the dead material column in the furnace hearth based on the static pressure of the furnace body. The method includes steps S101 to S104:

[0047] Step S:110: Multiple static pressure test points are preset at the lower part of the furnace body, and multiple static pressure test values ​​are continuously obtained.

[0048] The description will be based on a 3700m³ blast furnace. Figure 2 As shown, 10 furnace body static pressure measuring holes are installed at the 4th and 7th cooling wall sections of the tuyeres to measure the furnace body static pressure in 10 directions, ΔP. i (i = 1, ..., 10) generally varies within the range of 0.04-0.1 MPa. △P i (i = 1, ..., 10) No adjustment is needed below 0.07 MPa; above 0.07 MPa, furnace condition monitoring is required to promptly address any issues related to the permeability of the dead material column. Simultaneously, the measured static pressure P at the bottom of the furnace body is stored in the database. i (i is between 6 and 12), the measurement frequency is once every 30 seconds, and a total of 100 days of measurement data are saved. There are generally 6-12 pressure measurement points at the bottom of the furnace body, and the total amount of data is around 40,000.

[0049] Step S120: Calculate the difference between the blower pressure and multiple static pressure test values ​​to obtain the static pressure change value;

[0050] In this step, the change in static pressure is calculated according to a preset formula:

[0051] △P i =P0-P i

[0052] Where P0 is the blower pressure, with a value of 0.47 MPa, and i is 10.

[0053] Step S130: Calculate the pressure fluctuation range of each static pressure test point within a preset time period based on the above static pressure change value.

[0054] The formula for calculating the fluctuation range of static pressure measurement points in the furnace body within 1 hour (preset time) is as follows:

[0055] Dev_P i =(△P) i ) max -(△P i ) min

[0056] The calculated data is shown in the table below:

[0057] 1 0.32 0.36 0.04 2 0.34 0.355 0.015 3 0.35 0.36 0.01 4 0.360 0.375 0.015 5 0.358 0.376 0.018 6 0.348 0.359 0.011 7 0.355 0.370 0.015 8 0.366 0.370 0.004 9 0.36 0.375 0.015 10 0.362 0.374 0.012

[0058] And from this, max(Dev_P) is calculated. i = 0.018MPa, 0.6*max(Dev_P) i = 0.0108 MPa.

[0059] Step S140: When the pressure fluctuation range exceeds the preset normal range and reaches the preset threshold, it is determined that the air permeability of the dead material column exceeds expectations.

[0060] It should be noted that, for the normal range, based on a large amount of experimental data, it is between 0 and 0.6*max(Dev_P) i Within the range of ) the static pressure fluctuation of the furnace body (Fluc_△P) i Normal, once Flux_△P i ≥0.6*[max(Dev_P i If the value is less than or equal to 1, it indicates that the value is outside the control range. Additionally, if Flux_ΔP is less than or equal to 1 hour... i ≥0.6*[max(Dev_P i If the number of cycles exceeds 80, the air permeability of the aforementioned dead material column is determined to be beyond expectations. Based on the above data, the results are as follows:

[0061] Within the range of 0-0.0108 MPa, the static pressure fluctuation of the furnace body is normal. When the pressure fluctuation range is Flux_ΔP... i ≥0.0108MPa, exceeding the normal range, and if Flux_ΔP exceeds this range within 1 hour... i If the pressure is ≥0.0108MPa more than 80 times, then the permeability of the dead material column is judged to be beyond expectations.

[0062] Furthermore, after determining that the permeability of the aforementioned dead material column exceeds expectations, the above method further includes:

[0063] The blast furnace operating parameters are adjusted until the pressure fluctuation range meets the preset conditions.

[0064] It should be noted that △P i Corresponding to the difference in airflow distribution between the center and the edge, for blast furnaces below the softening zone, the permeability of the blast furnace mainly depends on the degree of penetration of the gas from the swirling zone to the center of the dead stack. The dead stack has high coke thermal intensity, large porosity, large coke particle size, and sufficient furnace temperature, resulting in a greater ability of the gas from the swirling zone to enter the center of the dead stack. For the same volume of gas generated, a higher proportion is distributed inside the dead stack, while a smaller proportion is distributed at the edge of the dead stack. Therefore, less gas passes through the same edge cross-sectional area, resulting in lower gas resistance and ΔP. i Small, conversely △P iThe value of (i = 1, ..., 8) will increase, and the change in the value of ΔPi corresponds to the change in the gas flow of the dead column. The preset condition for the pressure fluctuation range is: "until ΔP..." i <0.6*Dev_P i And it meets the control target of ≤40 times per hour.

[0065] Furthermore, the permeability of the lower part of the deadweight column has a crucial impact on the smooth operation of the blast furnace. In actual blast furnace operation, the change in the value of ΔPi can be used to analyze and characterize the state of the deadweight column. Except for the stable operating range, once ΔPi... i Entering the abnormal range requires serious attention. A comprehensive analysis of various factors affecting the state of the deadweight column should be conducted, and appropriate measures should be taken to maintain its permeability. Prolonged deterioration of deadweight column permeability should be avoided, as this slows the central coke turnover rate, increases coke breakage within the deadweight column, worsens liquid permeability, and deteriorates the hearth condition, leading to abnormal conditions such as material slippage, pipe adhesion, and furnace lining sticking. This will prevent significant losses to blast furnace production. Specific corrective measures are as follows:

[0066] Furthermore, the steps for correcting the blast furnace operating parameters described above also include:

[0067] When the quality of coke deteriorates but the thermal strength of the coke does not exceed a preset threshold, the coke load is adjusted by controlling the amount of deteriorated coke used.

[0068] It should be noted that if the quality of coke deteriorates and the hot strength (CSR) of the coke is less than 65%, the use of deteriorated coke should be controlled and the coke load should be adjusted until the oxygen-carbon ratio (O / C ratio) is reduced by 0.2 to 0.4.

[0069] Furthermore, such as Figure 3 As shown, the above steps for adjusting the coke load by controlling the amount of degraded coke used also include:

[0070] Step 141: Control the blast furnace temperature and ensure that the silicon content is greater than or equal to a preset threshold.

[0071] It should be noted that adjusting the blast furnace temperature, ensuring the silicon content in the molten iron is ≥0.4%, and maintaining a temperature of ≥1510℃ per ton of molten iron are all aimed at reducing the coke load and increasing the amount of coke used.

[0072] Furthermore, the above-mentioned steps for adjusting the coke load by controlling the amount of degraded coke used also include:

[0073] Step 142: Adjust the blast furnace basicity to ensure that the sulfur content in the molten iron is less than the preset threshold.

[0074] It should be noted that blast furnace basicity refers to slag basicity, which is the CaO / SiO2 ratio, between 1.05 and 1.18; ensuring that the sulfur content [S] in the molten iron is ≤0.040%. The purpose is to adjust the basicity to ensure that the minimum amount of coke is used to provide appropriate heat and achieve good slag fluidity.

[0075] Furthermore, the above-mentioned steps for adjusting the coke load by controlling the amount of degraded coke used also include:

[0076] Step 143: Adjust the amount of ore used in the blast furnace and the angle of the charge distribution until an M-shaped charge surface is formed on the top of the furnace.

[0077] It should be noted that adjusting the charging system by reducing the amount of ore at the edges and narrowing the charging angle inwards creates an "M"-shaped charge surface at the furnace top. The purpose of this adjustment is to loosen the edges, ensure stable edge airflow, and prevent the formation of ducts that stick together at the edges, which could cause blast furnace malfunctions, resulting in significant coke losses.

[0078] Furthermore, the above-mentioned steps for adjusting the coke load by controlling the amount of degraded coke used also include:

[0079] Step 144: Within the preset total center focus ring range, adjust the center focus amount.

[0080] It should be noted that for the amount of coking at the center, the total number of center coking rings should be ≤3. The purpose is to reduce the size of the dead material column and control the smooth flow of air in the center.

[0081] Furthermore, the above-mentioned steps for adjusting the coke load by controlling the amount of degraded coke used also include:

[0082] Step 145: Adjust the blast furnace air intake area according to the required blast kinetic energy and wind speed.

[0083] It should be noted that, based on the required blower kinetic energy and wind speed, the air intake area can be reduced according to the plan to ensure sufficient blower kinetic energy and wind speed. This can increase the blower kinetic energy and wind speed, thereby improving the coke combustion efficiency.

[0084] It should be noted that the order of operations for steps 141 to 145 above can be interchanged depending on the specific conditions inside the blast furnace.

[0085] Furthermore, before calculating the difference between the blower pressure and the multiple static pressure test values, the method further includes:

[0086] Based on the preset normal air volume and the blast furnace required blast kinetic energy, the coefficient between the normal air volume and the required air volume is determined to obtain the reference range of the required air volume.

[0087] Calculate the blower pressure based on the above benchmark range.

[0088] It should be noted that direct detection of blast pressure using sensors is difficult. Therefore, a coefficient between the normal blast volume and the required blast kinetic energy is determined using the normal blast volume and the required blast energy of the blast furnace, thus obtaining the baseline range for the required blast volume; that is, the required blast volume (BV) ≥ 0.9 * BV_Nor, where BV_Nor is the normal blast volume, taken as 5600 m³ / min. Then, the blast volume data is converted using the blast volume and blast pressure conversion formula, allowing subsequent calculations to be completed simply by detecting the blast volume data, thus improving convenience.

[0089] Based on the same inventive concept, embodiments of this application provide a system for determining the state of the dead material column in the furnace hearth based on the static pressure of the furnace body, such as... Figure 4 As shown, it includes:

[0090] The static pressure detection module 201 is used to preset multiple static pressure test points in the lower part of the furnace body and continuously detect and obtain multiple static pressure test values.

[0091] The static pressure change calculation module 202 is used to calculate the difference between the blower pressure and multiple static pressure test values ​​to obtain the static pressure change value;

[0092] The fluctuation range calculation module 203 is used to calculate the pressure fluctuation range of each static pressure test point within a preset time based on the static pressure change value.

[0093] The result module 204 is used to determine that the air permeability of the dead material column exceeds expectations when the pressure fluctuation range exceeds the preset normal range and reaches the preset threshold.

[0094] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0095] In summary, this invention provides a method for determining the state of the dead stock in the furnace hearth based on the static pressure of the furnace body, comprising:

[0096] First, by utilizing the static pressure changes in the blast furnace body at points 8-12 in the lowest section, corresponding to the differences in airflow distribution between the center and the edge, the pressure difference ΔP between the blast pressure and the static pressure in the lower part of the furnace body is measured. i The changes in the deadweight column are used to characterize its state, allowing for timely assessment and evaluation of its impact on blast furnace operation. Corresponding measures are then implemented to adjust the deadweight column, maintaining its stability and keeping the blast furnace in a stable state for extended periods. This prevents an increase in coke breakage within the deadweight column, deterioration of its permeability, and subsequent worsening of the hearth condition, leading to abnormal situations such as material slippage, pipe adhesion, and furnace lining sticking, which could cause significant losses to blast furnace production.

[0097] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0098] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for determining the state of the dead material column in the hearth based on the static pressure of the furnace body, characterized in that, include: Multiple static pressure test points are preset at the lower part of the furnace body, and multiple static pressure test values ​​are continuously obtained. The difference between the blower pressure and the multiple static pressure test values ​​is calculated to obtain the static pressure change value; Based on the static pressure change value, calculate the pressure fluctuation range of each static pressure test point within a preset time period; When the pressure fluctuation range exceeds the preset normal range and reaches the preset threshold; it is determined that the permeability of the dead material column exceeds expectations; and after determining that the permeability of the dead material column exceeds expectations, the blast furnace operating parameters are corrected until the pressure fluctuation range meets the preset conditions; wherein, the step of correcting the blast furnace operating parameters includes: when the coke quality deteriorates and the hot strength of the coke does not exceed the preset threshold, the coke load is adjusted by controlling the amount of deteriorated coke used.

2. The method according to claim 1, characterized in that, The step of adjusting the coke load by controlling the amount of degraded coke used also includes: Control the blast furnace temperature and ensure that the silicon content is greater than or equal to a preset threshold.

3. The method according to claim 1, characterized in that, The step of adjusting the coke load by controlling the amount of degraded coke used also includes: Adjust the blast furnace basicity to ensure that the sulfur content in the molten iron is less than the preset threshold.

4. The method according to claim 1, characterized in that, The step of adjusting the coke load by controlling the amount of degraded coke used also includes: Adjust the amount of ore used in the blast furnace and the angle of the charge distribution until an M-shaped charge surface is formed on the top of the furnace.

5. The method according to claim 1, characterized in that, The step of adjusting the coke load by controlling the amount of degraded coke used also includes: Within the preset total center focus ring number range, adjust the center focus amount.

6. The method according to claim 1, characterized in that, The step of adjusting the coke load by controlling the amount of degraded coke used also includes: Adjust the blast furnace air intake area according to the required blast kinetic energy and wind speed.

7. The method according to claim 1, characterized in that, Before calculating the difference between the blower pressure and the plurality of static pressure test values, the method further includes: Based on the preset normal air volume and the blast furnace required blast kinetic energy, the coefficient between the normal air volume and the required air volume is determined to obtain the reference range of the required air volume. The blower pressure is calculated based on the aforementioned benchmark range.

8. A system for determining the state of the dead material column in the hearth based on the static pressure of the furnace body, characterized in that, include: The static pressure detection module is used to preset multiple static pressure test points at the bottom of the furnace body and continuously detect and obtain multiple static pressure test values. The static pressure change calculation module is used to calculate the difference between the blower pressure and multiple static pressure test values ​​to obtain the static pressure change value; The fluctuation range calculation module is used to calculate the pressure fluctuation range of each static pressure test point within a preset time based on the static pressure change value. The result module is used to determine that the permeability of the dead material column exceeds expectations when the pressure fluctuation range exceeds a preset normal range and reaches a preset threshold; and after determining that the permeability of the dead material column exceeds expectations, to correct the blast furnace operating parameters until the pressure fluctuation range meets the preset conditions; wherein, the step of correcting the blast furnace operating parameters includes: when the coke quality deteriorates and the hot strength of the coke does not exceed a preset threshold, controlling the amount of deteriorated coke used to adjust the coke load.

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