Method for estimating supplied heat, device for estimating supplied heat, computer-readable recording medium recording supplied heat estimation program, and method for operating blast furnace

Abstract

The present invention relates to a supply heat estimation method for estimating heat supplied to pig iron in a blast furnace based on heat supplied to the blast furnace and a production rate of molten iron in the blast furnace, wherein the supply heat estimation method includes an estimation step of estimating a change in outgoing sensible heat caused by gas in the furnace and a change in incoming sensible heat supplied by raw material preheated by the gas in the furnace, and estimating the heat supplied to the pig iron in the blast furnace by taking into account the estimated changes in the outgoing sensible heat and the incoming sensible heat, the estimation step including a step of estimating the outgoing sensible heat by taking into account heat emitted to the outside of the blast furnace due to a collapse, and estimating the change in the incoming sensible heat by taking into account a change in a surface height of the raw material caused by the collapse, and a step of estimating heat held by coke present in a hearth core of the blast furnace, and estimating the heat supplied to the pig iron in the blast furnace by taking into account the estimated heat held by the coke in the hearth core.

Description

Technical Field

[0001] This invention relates to a method, apparatus, procedure, and operation method for estimating the heat supplied to pig iron in a blast furnace. Background Technology

[0002] Typically, to ensure stable operation of a blast furnace, the temperature of molten iron needs to be maintained within a specified range. Specifically, if the molten iron temperature is low, the viscosity of the molten iron and the slag produced with it increases, making it difficult to discharge them from the taphole. Conversely, if the molten iron temperature is high, the Si concentration in the molten iron increases, further increasing its viscosity. This increases the risk of the molten iron sticking to the tuyeres and causing them to melt. Therefore, to ensure stable operation of the blast furnace, fluctuations in the molten iron temperature need to be suppressed. Against this backdrop, various methods for estimating the heat supplied to the blast furnace and the temperature of the molten iron have been proposed. Specifically, Patent Document 1 discloses a furnace heat control method for a blast furnace, characterized by estimating the molten iron temperature after a specific time period based on the displacement of the furnace heat index at the current time point from a furnace heat index reference level corresponding to the target molten iron temperature, the displacement of the unloading speed at the current time point from a furnace top unloading speed reference level corresponding to the target molten iron temperature, and the time the two displacements affect the molten iron temperature. Based on this estimation result, furnace heat control operations are performed to reduce fluctuations in the molten iron temperature. Furthermore, Patent Document 2 discloses a method for predicting the molten iron temperature of a blast furnace. This method predicts the future molten iron temperature based on operational data including actual values ​​of blast conditions data (at least one of blast furnace blast temperature, blast humidity, blast volume, fine carbon injection amount, and oxygen enrichment), actual values ​​of interference factor data (at least carbon dissolution amount), and actual values ​​of the molten iron temperature. The method is characterized by comprising: a data accumulation step for accumulating operational data; a stable state prediction model construction step for constructing a stable state prediction model that predicts the molten iron temperature in a stable state based on the operational data accumulated in the data accumulation step; an unstable state prediction model construction step for constructing an unstable state prediction model that reduces the dimensionality of the stable state prediction model and predicts the molten iron temperature in an unstable state based on the operational data accumulated in the data accumulation step; and a molten iron temperature prediction step for predicting the molten iron temperature based on the constructed stable state prediction model and the unstable state prediction model.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2-115311

[0006] Patent Document 2: Japanese Patent Application Publication No. 2008-144265 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] The likelihood of significant fluctuations in molten iron temperature is high when changes in operational parameters such as the blast furnace feed rate lead to variations in the amount of molten iron produced and the amount of pig iron relative to the heat supplied to the blast furnace. Particularly, when the force pushing the raw material up by the gas in the blast furnace becomes greater than the force causing the material to fall, and the material stops falling, the molten iron temperature fluctuates dramatically when the surface height of the raw material drops sharply due to the breakdown of this relationship, i.e., a so-called slip occurs. However, the method described in Patent Document 1 does not consider factors such as the carry-over of sensible heat from the blast furnace feed, which is believed to change with operational parameters, and therefore cannot accurately estimate the heat supplied to the pig iron when operational parameters change significantly. On the other hand, the method described in Patent Document 2 assumes that the accuracy of molten iron temperature estimation decreases when operational changes that have not previously accumulated occur. Furthermore, in cases of low molten iron temperature estimation accuracy, as described above, there is often an excessive heat supply, raising concerns about equipment malfunction. Additionally, from the perspective of reducing carbon dioxide emissions, excessive use of reducing materials as carbon sources is also undesirable.

[0009] The present invention was made in view of the above-mentioned problems, and its object is to provide a method, apparatus, and procedure for estimating the heat supply, which can accurately estimate the heat of pig iron supplied to the blast furnace even under significant changes in operating conditions, especially in the event of a collapse. Another object of the present invention is to provide a method for operating a blast furnace that can appropriately maintain the heat of pig iron supplied to the blast furnace and accurately control the molten iron temperature within a specified range, even under significant changes in operating conditions, especially in the event of a collapse.

[0010] Technical solutions for solving the problem

[0011] The method for estimating the supply heat involved in this invention estimates the heat of pig iron supplied to the blast furnace based on the heat supplied to the blast furnace and the production rate of molten iron in the blast furnace. The method includes an estimation step that estimates the change in sensible heat carried out by the gas passing through the furnace and the change in sensible heat brought in by the raw materials preheated by the gas passing through the furnace. The estimated changes in sensible heat carried out and brought in are considered to estimate the heat of pig iron supplied to the blast furnace. The estimation step includes the following steps: estimating the sensible heat carried out by considering the heat released outside the blast furnace due to material collapse, and estimating the change in sensible heat brought in by considering the change in the surface height of the raw materials caused by material collapse; and estimating the heat held by the coke present in the blast furnace core, and estimating the heat of pig iron supplied to the blast furnace by considering the estimated heat held by the coke.

[0012] In addition, the estimation step may include the following steps: multiplying the specific heat of the furnace top gas by the difference between the furnace top gas temperature and the reference temperature of the furnace top gas temperature to calculate the multiplication value, and adding the multiplication value to the ironmaking speed and the resulting value to the sensible heat carried out, thereby considering the heat released outside the blast furnace due to the collapse of the material to estimate the sensible heat carried out.

[0013] Additionally, the estimation step may include the following steps: estimating the change in sensible heat by taking into account the change in the surface height of the raw material caused by material collapse, by calculating the raw material temperature as a function of the cumulative difference between the estimated value and the actual value of the raw material surface height.

[0014] The heat supply estimation device of the present invention estimates the heat of pig iron supplied to the blast furnace based on the heat supplied to the blast furnace and the production rate of molten iron in the blast furnace. The device includes an estimation unit that estimates the change in sensible heat carried out by the gas passing through the furnace and the change in sensible heat brought in by the raw materials preheated by the gas passing through the furnace. The estimation unit estimates the heat of pig iron supplied to the blast furnace by considering the estimated changes in sensible heat carried out and brought in. The estimation unit estimates the sensible heat carried out by considering the heat released outside the blast furnace due to material collapse, and estimates the change in the surface height of the raw materials caused by material collapse. It also estimates the heat held by the coke in the blast furnace core and estimates the heat of pig iron supplied to the blast furnace by considering the estimated heat held by the coke in the blast furnace core.

[0015] The heat supply estimation procedure involved in this invention enables a computer to perform a process of estimating the heat of pig iron supplied to the blast furnace based on the heat supplied to the blast furnace and the production rate of molten iron in the blast furnace. The computer performs an estimation process that estimates the change in sensible heat carried out by the gas passing through the furnace and the change in sensible heat brought in by the raw materials preheated by the gas passing through the furnace. The estimated changes in sensible heat carried out and brought in are considered to estimate the heat of pig iron supplied to the blast furnace. The estimation process includes the following steps: estimating the sensible heat carried out by considering the heat released outside the blast furnace due to material collapse; estimating the change in the sensible heat brought in by considering the change in the surface height of the raw materials caused by material collapse; estimating the heat held by the coke present in the blast furnace core; and estimating the heat of pig iron supplied to the blast furnace by considering the estimated heat held by the coke in the blast furnace core.

[0016] The blast furnace operation method involved in this invention includes the following steps: controlling the heat supplied to the blast furnace based on the heat of pig iron supplied to the blast furnace estimated by the heat supply estimation method involved in this invention.

[0017] Invention Effects

[0018] According to the method, apparatus, and procedure for estimating the heat supply of the blast furnace, even under significant changes in operating conditions, particularly in the event of a collapse, the heat supplied to the pig iron in the blast furnace can be estimated with high accuracy. Furthermore, the blast furnace operation method according to the present invention can appropriately maintain the heat supplied to the pig iron in the blast furnace and precisely control the molten iron temperature within a specified range, even under significant changes in operating conditions, particularly in the event of a collapse. Attached Figure Description

[0019] Figure 1 This is a block diagram showing the structure of a furnace heat control device as one embodiment of the present invention.

[0020] Figure 2 This is a flowchart illustrating the process of furnace heat control as one embodiment of the present invention.

[0021] Figure 3 This is a graph illustrating an example of the relationship between conventional indices and the furnace heat index of the present invention, and the temperature difference relative to the reference molten iron temperature. Detailed Implementation

[0022] Hereinafter, with reference to the accompanying drawings, the structure and operation of a furnace heat control device, which is an embodiment of the present invention, applies the heat supply estimation method and heat supply estimation device involved in the present invention.

[0023] [structure]

[0024] First, refer to Figure 1 The structure of a furnace heat control device, which is one embodiment of the present invention, will be described. Figure 1 This is a block diagram illustrating the structure of a furnace heat control device as one embodiment of the present invention. (Example) Figure 1 As shown, the furnace heat control device 1, as one embodiment of the present invention, is composed of an information processing device such as a computer. It controls the temperature of the molten iron produced in the blast furnace 2 within a specified range by controlling the heat supplied to the molten metal from the tuyeres located at the lower part of the blast furnace 2. The furnace heat control device 1 functions as a heat supply estimation device according to the present invention.

[0025] The furnace heat control device 1, with such a structure, performs the furnace heat control process as described below, thereby accurately estimating the heat supplied to the pig iron in the blast furnace 2 even when the operating degree of the blast furnace 2 changes significantly, especially when a collapse occurs. Using the estimation result, it appropriately maintains the heat supplied to the pig iron in the blast furnace 2, and accurately controls the molten iron temperature within a specified range. Hereinafter, refer to... Figure 2The process of furnace heat control processing as one embodiment of the present invention will be described.

[0026] Furthermore, the operation of the furnace heat control device 1 described below is achieved by a processing unit such as a CPU within the information processing unit constituting the furnace heat control device 1, which loads program 1a from a storage unit such as ROM into a temporary storage unit such as RAM and executes the loaded program 1a. Program 1a may also be provided as a file recorded on a computer-readable recording medium such as a CD-ROM, floppy disk, CD-R, or DVD in an installable or executable form. Program 1a may also be provided by storing it on a computer connected to a network such as an electrical communication line (e.g., the Internet), a telephone communication network (e.g., a mobile phone), or a wireless communication network (e.g., WiFi), and downloading it from the network.

[0027] [Furnace thermal control treatment]

[0028] Figure 2 This is a flowchart illustrating the process of furnace heat control as one embodiment of the present invention. Figure 2 In the flowchart shown, starting from the moment the execution command for the furnace heat control process is input to the furnace heat control device 1, the furnace heat control process, in addition to the always-performing step S1 of estimating the heat supplied to the blast furnace based on the reaction heat balance (heat generated by reaction, heat absorbed by reaction), sensible heat of the blast air, and heat loss (heat released from the furnace body, etc.), also performs steps S2, S3, and S4, and integrates these processes into step S5 of estimating the supplied heat. Step S1, which estimates the heat supplied to the blast furnace based on the reaction heat balance (heat generated by reaction, heat absorbed by reaction), sensible heat of the blast air, and heat loss (heat released from the furnace body, etc.), has always been performed, and the supplied heat at this time is set as Q0. A preferred example of the process for step S1 will be described later.

[0029] In step S2, the furnace heat control device 1 estimates the sensible heat (sensible heat carried out by the gas) Q7 carried out from the lower part of the blast furnace 2 to the upper part of the blast furnace 2 by the gas (gas passing through the furnace). Specifically, the sensible heat Q7 (MJ / tp: heat per ton of pig iron. Hereinafter, tp indicates the number of tons of pig iron) can be calculated as follows: (1) The first multiplication value is calculated by multiplying the estimated temperature (theoretical combustion temperature) of the gas burning in front of the tuyeres and the reference temperature representing the temperature of the upper part of the lower part of the blast furnace by the specific heat of the gas; (2) The second multiplication value is calculated by multiplying the specific heat of the gas at the top of the furnace by the difference between the temperature of the gas at the top of the furnace (exhaust temperature at the top of the furnace) and the reference temperature of the gas at the top of the furnace; (3) The value obtained by adding the first multiplication value and the second multiplication value is divided by the ironmaking speed, as shown in the following mathematical formula (1). By adding the first multiplication value to the second multiplication value and dividing the result by the ironmaking speed, the heat released outside the furnace due to material collapse without heat exchange with the raw materials can be considered to accurately evaluate the sensible heat Q7 carried out by the gas. Thus, step S2 is completed, and the process proceeds to step S5.

[0030] [Mathematical Expression 1]

[0031]

[0032] Among them, C bosh，i This indicates the specific heat (MJ / m³) of gas type i (nitrogen, carbon monoxide, hydrogen) in the gas passing through the furnace (furnace gas). 3 / ℃), C top，i This represents the specific heat (MJ / m³) of gas type i (nitrogen, carbon monoxide, carbon dioxide, hydrogen, water vapor) in the furnace top gas. 3 / ℃), V bosh，i This indicates the flow rate (m³) of gas type i passing through the furnace. 3 (stp) / min)(m 3 (stp): Volume at 0℃ and 1 atm (atmosphere), V top，i This indicates the flow rate (m³) of gas type i in the gas at the furnace top. 3 (stp) / min), TFT represents the theoretical combustion temperature (°C), T base T represents the reference temperature (°C) (800–1200°C, preferably 900–1000°C). top T represents the temperature of the gas at the furnace top (°C). top，base The reference temperature (°C) representing the furnace top gas temperature (80–300°C, preferably 100–200°C), Pig represents the ironmaking speed (tp / min), α bosh α topThis indicates the influence coefficients that change according to blast furnace 2. These values ​​can be obtained, for example, from a host computer 3, such as a process computer connected to the furnace thermal control device 1 via an electrical communication line.

[0033] In step S3, the furnace heat control device 1 estimates the sensible heat (material-carried sensible heat) Q8 brought into the lower part of the blast furnace 2 by the raw material supplied from the upper part to the lower part. Specifically, the material-carried sensible heat Q8 (MJ / tp) can be expressed as shown in the following mathematical formula (2) by the raw material temperature T1 (=1450~1500℃) at the lower end of the weld band and the reference temperature T. base The temperature difference is calculated by multiplying the specific heat of the raw material. Additionally, the raw material temperature T1 is the difference ΔL between the estimated and actual values ​​of the raw material surface height, as shown in the following mathematical formula (3). surface The function of the differential value. Based on such a raw material temperature T1 setting, it is possible to consider the situation where the raw material temperature T1 decreases depending on the height of the raw material surface where the material collapses. Therefore, it is possible to evaluate with high precision the situation where the raw material becomes poorly heated due to the collapse and the heat carried by the raw material to the lower part of the furnace is reduced.

[0034] In detail, under normal operating conditions, the volume of raw materials and coke in the blast furnace decreases according to the ironmaking rate, thus the surface height of the raw material packing layer in the blast furnace continuously decreases. Here, the surface height of the raw material packing layer is measured using a sensor. When the surface height of the raw material packing layer decreases to a predetermined height, the operation of repeatedly replenishing raw materials and coke is performed to restore the surface height of the raw material packing layer to its original height. On the other hand, just before a collapse occurs, the volume of raw materials in the blast furnace itself continuously decreases according to the ironmaking rate, but at a certain point, the descent of raw materials is hindered, so the surface height of the raw material packing layer only decreases slightly or at a certain point. Therefore, the difference ΔL between the surface height of the raw material packing layer estimated based on the ironmaking rate and the sensor measurement value is always calculated in advance. surface The change in dΔL when the difference shrinks sharply surface / dt represents the amount of material breakage, and its magnitude can be used to evaluate the impact of material breakage on poorly heated raw materials. The same evaluation can also be performed by simply continuously measuring the change in the surface height of the raw material packing layer and considering it as material breakage when it exceeds a threshold. Furthermore, when there are multiple measurement directions for the surface height of the raw material packing layer, the same evaluation can be performed for each measurement direction, and the impact can be proportionally allocated according to the proportion of measurement directions where material breakage occurred. Alternatively, the average value of each measurement direction can be used to evaluate material breakage. Thus, step S3 is completed, and the process proceeds to step S5.

[0035] [Mathematical Expression 2]

[0036] Q8=β·{∑(C j ·Rj )}·(T1-T base (2)

[0037] Here, C j R represents the specific heat (MJ / kg / ℃) of raw material j (coke, pig iron, slag). j T represents the consumption rate of raw material j (kg / tp), T1 represents the raw material temperature at the lower end of the welded strip (°C), and T base The reference temperature (°C) is represented by β, and the influence coefficient varies depending on the blast furnace 2. These values ​​can be obtained, for example, from the host computer 3.

[0038] [Mathematical Expression 3]

[0039] T1=f(dΔL surface / dt)…(3)

[0040] In step S4, the furnace heat control device 1 estimates the heat retained by the coke in the lower part of the blast furnace 2 (coke retention heat) Q9. Specifically, the coke retention heat Q9 (MJ / tp) can be obtained by subtracting the amount of combustion consumption and the amount of carbon discharged in the form of dust from the coke consumption rate per ton of molten iron, multiplied by the difference between the reference temperature and the theoretical combustion temperature and the specific heat C of the coke. coke The result is given by the mathematical expression (4) shown below. Thus, step S4 is completed, and we proceed to step S5.

[0041] [Mathematical Expression 4]

[0042]

[0043] Here, C coke T represents the specific heat of coke (MJ / kg / ℃), TFT represents the theoretical combustion temperature (℃), and T represents the theoretical combustion temperature. base CR represents the reference temperature (°C), and CR represents the coke ratio (kg / tp). burn The carbon-to-fuel ratio (calcium per unit area) before the air outlet (including the oxygen consumed before the air outlet due to humidification) is expressed as (kg / tp). PCR represents the carbon-to-fuel ratio of the micronized powder (kg / tp). inPC C represents the carbon ratio in micronized charcoal. sol The carbon solubility ratio (kg / tp) is represented by C, and the dust ratio (kg / tp) is represented by Dust. indust The carbon ratio in the dust is represented by γ, and δ represents the influence coefficients that vary depending on the blast furnace 2. These values ​​can be obtained, for example, from the host computer 3.

[0044] In step S5, the furnace heat control device 1 uses the supplied heat Q0 estimated in step S1, the gas-carried sensible heat Q7 estimated in steps S2-S4, the raw material-carried sensible heat Q8, and the coke retention heat Q9 to estimate the heat of pig iron supplied to the blast furnace 2. Specifically, the furnace heat control device 1 calculates the furnace heat index T corresponding to the heat of pig iron supplied to the blast furnace 2 by substituting the supplied heat Q0 estimated in step S1, the gas-carried sensible heat Q7 estimated in steps S2-S4, the raw material-carried sensible heat Q8, and the coke retention heat Q9 into the following mathematical formula (5). Q (MJ / tp). Thus, step S5 is completed, and the process proceeds to step S6.

[0045] [Mathematical Expression 5]

[0046] T Q =Q0–Q7+Q8–Q9…(5)

[0047] Here, Q0 represents the heat supplied to the blast furnace through the reaction heat balance (reaction generation heat, reaction endothermic heat), sensible heat of the blower, and heat loss (heat released from the furnace body, etc.). It can be applied to the estimation method used in most cases in the previous estimation of the supply heat, but as a preferred method, mathematical formula (6) can be given.

[0048] [Mathematical Expression 6]

[0049] Q0 = Q1 + Q2 - Q3 - Q4 - Q5 - Q6…(6)

[0050] Here, Q1 represents the heat of combustion of the coke at the front end of the tuyeres (MJ / tp). The heat of combustion Q1 can be calculated by dividing the heat generated by the combustion of the coke, which is calculated based on the amount of oxygen supplied from the tuyeres to the blast furnace per unit time, by the amount of molten iron produced per unit time.

[0051] Additionally, Q2 represents the sensible heat of the blast furnace (MJ / tp) supplied through the blast from the tuyeres. The sensible heat of the blast Q2 can be calculated by determining the heat supplied to the blast furnace per unit time based on the measured values ​​of the blast volume and blast temperature per unit time, and then dividing this value by the amount of molten iron produced per unit time.

[0052] Additionally, Q3 represents the heat of reaction due to melting loss (MJ / tp). This value can be calculated, for example, by determining the amount of carbon lost based on the composition of the gas at the furnace top, as described in Patent Document 1. The heat of reaction due to melting loss Q3 can be calculated by dividing this heat of reaction due to melting loss by the amount of molten iron produced per unit time.

[0053] Additionally, Q4 represents the heat of decomposition (MJ / tp) of the main wet components contained in the supply air. The heat of decomposition Q4 can be calculated by dividing the heat of decomposition obtained from the measured value of the wet components in the supply air by the amount of molten iron produced per unit time.

[0054] Additionally, Q5 represents the heat loss from the furnace body (e.g., heat release caused by cooling water) (MJ / tp). When calculating the heat release caused by cooling water as heat loss, the heat release Q5 can be calculated as follows: calculate the heat release per unit time caused by cooling water based on the amount of cooling water and the temperature difference between the inlet and outlet sides of the cooling water in the blast furnace body, and divide the calculated heat release by the amount of molten iron produced in that unit time.

[0055] Additionally, Q6 represents the heat of decomposition of the reducing material blown in from the duct per unit time (MJ / tp). The heat of decomposition Q6 can be calculated by dividing the heat of decomposition by the amount of molten iron produced per unit time.

[0056] In step S6, the furnace heat control device 1 controls the heat supplied from the tuyeres to the blast furnace 2 based on the heat of the pig iron supplied to the blast furnace 2 estimated in step S5, thereby appropriately maintaining the heat of the pig iron supplied to the blast furnace 2 and controlling the molten iron temperature within a specified range. Thus, step S6 is completed, and the series of furnace heat control processes ends.

[0057] As can be seen from the above description, in the furnace heat control process of one embodiment of the present invention, the furnace heat control device 1 estimates the change in sensible heat carried out to the upper part of the blast furnace due to the gas passing through the furnace and the change in sensible heat brought in by the raw materials preheated by the gas passing through the furnace and supplied to the lower part of the blast furnace, and estimates the heat of pig iron supplied to the blast furnace by taking into account the estimated changes in sensible heat carried out and brought in. In addition, the furnace heat control device 1 estimates the sensible heat carried out by taking into account the heat released outside the blast furnace due to the collapse of the material, and estimates the change in the surface height of the raw materials caused by the collapse of the material, and estimates the heat held by the coke in the furnace core, and estimates the heat of pig iron supplied to the blast furnace by taking into account the estimated heat held by the coke in the furnace core. Therefore, even when the operating conditions such as the blast rate to the blast furnace change significantly, especially when a collapse of the material occurs, the heat of pig iron supplied to the blast furnace can be estimated with high accuracy. Furthermore, this allows for the proper maintenance of the heat supplied to the pig iron in the blast furnace and precise control of the molten iron temperature within the specified range, even when there are significant changes in the operating conditions, especially in the event of a collapse.

[0058] [Example]

[0059] Figure 3This indicates the result obtained by comparing the previous furnace heat index (estimated using Q1 to Q6) and the furnace heat index of this invention (estimated using Q1 to Q9) at the moment when the collapse occurred with the actual molten iron temperature (the difference relative to the reference molten iron temperature). Figure 3 As shown, in the furnace heat index of the present invention (example of the present invention), compared with the conventional furnace heat index (comparative example), it can be confirmed that there is a certain correlation between the furnace heat index and the molten iron temperature (the difference relative to the reference molten iron temperature). Furthermore, Table 1 shows the results after summarizing the standard deviations of the difference between the estimated molten iron temperature and the actual molten iron temperature considering various factors. It can be seen that compared with the conventional furnace heat index which only uses Q1 to Q6 to estimate the furnace heat index, the estimation accuracy is improved by considering the case of material collapse (in the example of the present invention, Q1 to Q9 are used to estimate the furnace heat index). Therefore, it can be seen that by using the furnace heat index of the present invention, even when the operating conditions change significantly, especially when material collapse occurs, the heat supplied to the pig iron in the blast furnace can be appropriately maintained, and the molten iron temperature can be controlled with high precision within a specified range.

[0060] [Table 1]

[0061]

[0062] The embodiments of the invention made by the inventors of this invention have been described above, but the invention is not limited to the description and drawings that constitute a part of the disclosure of the invention based on these embodiments. That is, all other embodiments, examples, and applications made by those skilled in the art based on these embodiments are included within the scope of this invention.

[0063] Industrial applicability

[0064] According to the present invention, a method, apparatus, and procedure for estimating the heat supply can be provided, which can accurately estimate the heat of pig iron supplied to the blast furnace even under significant changes in operating conditions, particularly in the event of a collapse. Furthermore, another object of the present invention is to provide a method for operating a blast furnace that can appropriately maintain the heat of pig iron supplied to the blast furnace and accurately control the molten iron temperature within a specified range, even under significant changes in operating conditions, particularly in the event of a collapse.

[0065] Label Explanation

[0066] 1. Furnace thermal control device

[0067] 1a Program

[0068] 2 Blast Furnace

[0069] 3. Host computer.

Claims

1. A method for estimating the heat supply, wherein the heat supplied to the pig iron in the blast furnace is estimated based on the heat supplied to the blast furnace and the rate of molten iron production in the blast furnace, wherein, The method for estimating the supplied heat includes an estimation step, which estimates the change in sensible heat carried out by the gas passing through the furnace and the change in sensible heat brought in by the raw materials preheated by the gas passing through the furnace. The estimated changes in sensible heat carried out and brought in are considered to estimate the heat supplied to the pig iron in the blast furnace. The estimation step includes the following steps: estimating the sensible heat carried out by considering the heat released outside the blast furnace due to the collapse, and estimating the change in the sensible heat carried in by considering the change in the surface height of the raw material caused by the collapse; and estimating the heat held by the core coke present in the blast furnace, and estimating the heat supplied to the pig iron in the blast furnace by considering the estimated heat held by the core coke.

2. The method for estimating the supplied heat according to claim 1, wherein, The estimation step includes the following steps: multiplying the specific heat of the furnace top gas by the difference between the furnace top gas temperature and the reference temperature of the furnace top gas temperature to calculate the multiplication value, and adding the multiplication value to the ironmaking speed and the resulting value to the sensible heat carried out, thereby estimating the sensible heat carried out by taking into account the heat released outside the blast furnace due to the collapse of the material.

3. The method for estimating the supplied heat according to claim 1 or 2, wherein, The estimation step includes the following steps: by calculating the cumulative value of the difference between the estimated value and the actual value of the raw material surface height as a function of the raw material temperature, the change in the sensible heat brought in is estimated by considering the change in the surface height of the raw material caused by material collapse.

4. A heat supply estimation device, which estimates the heat supplied to the pig iron in the blast furnace based on the heat supplied to the blast furnace and the rate of molten iron production in the blast furnace, wherein, The heat supply estimation device includes an estimation unit that estimates the change in sensible heat carried out by the gas passing through the furnace and the change in sensible heat brought in by the raw materials preheated by the gas passing through the furnace, and estimates the heat supplied to the pig iron in the blast furnace by taking into account the estimated changes in sensible heat carried out and brought in. The estimation unit estimates the sensible heat carried out by considering the heat released outside the blast furnace due to the collapse, and estimates the change in the sensible heat carried in by considering the change in the surface height of the raw material caused by the collapse, and estimates the heat held by the core coke present in the blast furnace, and estimates the heat supplied to the pig iron in the blast furnace by considering the estimated heat held by the core coke.

5. A computer-readable recording medium that records a process for estimating the heat supply, enabling a computer to execute a process for estimating the heat supplied to the pig iron in the blast furnace based on the heat supplied to the blast furnace and the rate of iron production in the blast furnace, wherein... The computer performs an estimation process that estimates the changes in sensible heat carried out by the gas passing through the furnace and the changes in sensible heat brought in by the raw materials preheated by the gas passing through the furnace. The estimated changes in sensible heat carried out and brought in are taken into account to estimate the heat supplied to the pig iron in the blast furnace. The estimation process includes the following steps: estimating the sensible heat carried out by considering the heat released outside the blast furnace due to the collapse, estimating the change in the sensible heat carried in by considering the change in the surface height of the raw material caused by the collapse, estimating the heat held by the core coke present in the blast furnace, and estimating the heat supplied to the pig iron in the blast furnace by considering the estimated heat held by the core coke.

6. A method of operating a blast furnace, comprising the following steps: controlling the heat supplied to the blast furnace based on the heat of pig iron supplied to the blast furnace estimated by the heat supply estimation method according to any one of claims 1 to 3.

Images