Blast furnace hearth molten iron storage closed-loop control and early warning method and system

Abstract

The invention provides a blast furnace hearth molten iron storage closed-loop control and early warning method and system.The method comprises the steps that on the basis of a blast furnace intelligent monitoring technology, air volume, air pressure, pig iron speed and tapping speed data are obtained in real time, and a hearth molten iron storage model is constructed; and then dividing the storage amount of the molten iron in the blast furnace into four stages: an opening slow flow stage, an opening fast flow stage, a plugging buffer stage and an iron stopping stage. On the basis of related data of the four stages, the corresponding relation between the tapping time and the tapping amount is explored, the corresponding relation between the molten iron stock and the pressure in the furnace is analyzed, and a molten iron stock early-warning value, a pressure early-warning value and the like are determined; based on the regression equation of the tapping time and the tapping amount, early warning is conducted on the stokehole opening and plugging operation by considering the in-furnace pressure amount relation, the method has important significance on reasonable and scientific management and control of the stokehole operation, and closed-loop control over the stokehole operation of the blast furnace is achieved.

Description

Technical Field

[0001] The invention belongs to the field of blast furnace hearth control, and in particular relates to a blast furnace hearth molten iron storage closed-loop control and early warning method and system. Background Art

[0002] The blast furnace is essentially a huge countercurrent heat exchanger and chemical reactor. The iron ore, coke and solvent added to the upper part of the blast furnace are used as raw materials. A series of reactions occur at the lower hot air tuyere to generate slag iron. The generated slag iron starts from the dripping zone and gathers along the coke gap to the furnace for short-term storage, and is discharged from the blast furnace by periodically opening the tap hole. Under ideal conditions, the speed of slag iron generation and collection in blast furnace smelting is the same as the speed of slag iron discharge at the tap hole, which can make the slag iron liquid level in the blast furnace relatively stable, reduce the residence time of slag iron in the furnace, and effectively alleviate the chemical erosion and thermal shock of slag iron on the refractory materials and lining of the furnace. However, in the actual production process, it is difficult to achieve real-time measurement of the slag iron liquid level in the furnace under the harsh operating environment of high temperature and pressure inside the furnace. In the absence of reliable safety basis, the timing of key processes such as tap hole opening and tap hole blocking is often determined by the operator based on the experience in front of the furnace. Under the influence of a series of factors such as slag fluidity, furnace equipment and raw materials, the operator's subjective judgment is bound to cause a large range of fluctuations in the slag liquid level in the blast furnace, which in turn leads to a series of problems such as air blockage in the furnace, burning of the tuyere, difficulty in iron mouth maintenance, and increased erosion of the inner wall of the furnace. This is especially true for large and extra-large blast furnaces in the later stages of their service life.

[0003] The patent application number is 201721538768.X, and its name is a blast furnace slag iron liquid level monitoring device. It is installed in the blast furnace using a channel steel bracket. Multiple armored thermocouples are respectively arranged at different heights of the channel steel bracket, and the temperature measuring head of the armored thermocouple is facing downward. The display instrument is connected to the armored thermocouple through a thermocouple junction box and a compensation wire, which is used to display the temperature in the blast furnace in real time. The monitoring equipment in this patent is installed in the blast furnace, and it needs to be installed before stopping production and opening the furnace. The equipment in the furnace is in high-temperature and pressurized molten iron for a long time, and is squeezed by the upper furnace charge. It is easy to be damaged and fail, and it is difficult to maintain and replace.

[0004] The patent application number is 201610088993.1, and the patent application named as blast furnace iron output estimation device and method includes a correlation determination module and a calculation module. The correlation determination module includes a liquid level unit and a determination unit. The liquid level unit reads the liquid level on the blast furnace side, and the determination unit reads the determined amount of each tank of molten iron on the steelmaking side. The correlation determination module calculates the corresponding relationship between the molten iron liquid level and the determined amount of molten iron based on the data of the liquid level unit and the determination unit. The calculation module includes an iron output estimation unit and an iron output correction unit. The iron output unit reads the actual liquid level inside the mixing car, substitutes the actual liquid level into the corresponding relationship between the molten iron liquid level and the determined amount of molten iron, and obtains the actual determined amount of molten iron inside the mixing car. The iron output correction unit corrects the corresponding relationship between the molten iron liquid level and the determined amount of molten iron according to the actual determined amount of molten iron. This patent does not provide a calculation method for key parameters such as theoretical pig iron yield and theoretical slag yield, and ignores the role of slag in the blast furnace smelting process. The iron in the blast furnace raw materials not only enters the molten iron, but also partially enters the slag. Therefore, the calculation method of this patent is difficult to reflect the actual situation.

[0005] The patent application number is 201610880421.7, and the name is a method and device for online measurement of slag and iron liquid level information in the blast furnace hearth. The high-precision electromotive force signal generated by the electromotive force measurement point is used as the measurement parameter. The computer system performs program code analysis on the data of different tuyere and different tapping holes to obtain the liquid level and dead material column information of the hearth. The measurement basis is the change in the heat transfer of the refractory material and the furnace shell of the hearth caused by the different heat storage capacity of slag and iron, and the measured value is the heat transferred by the refractory material and the furnace shell. The computer system responsible for code processing is a data visualization system. The electromotive force measurement point is composed of resistors, measuring probes and circuits, which realizes the direct analysis and calculation of the electromotive force generated by each electromotive force measurement point. The patent does not consider the electromotive force deviation caused by the uneven change of the hearth due to the erosion of the hearth. With the production of the blast furnace, irregular erosion and deformation occur inside the hearth, such as "elephant foot shape", especially in the later stage of the furnace service, this phenomenon is more significant, so it is difficult to use the electromotive force signal to truly feedback the change of the hearth liquid level.

[0006] The patent application number is 202311030145.1, and the name is a patent application for a monitoring system and method for the storage of slag iron in a blast furnace, which includes a raw material system, a slag iron system, a processing system and an early warning system. The method includes determining the chemical composition of the raw materials; formulating a material distribution system during the blast furnace charging process, recording each action time of the probe and the weight of the batch of materials; determining the data related to the iron tapping speed and the iron tapping weight; determining the data related to the slag tapping speed and the slag tapping weight; chemically testing the molten iron and slag; screening and processing the data fed back from the raw material system and the slag iron system; performing graded early warning on the data in the processing system, giving early warnings to the front desk operating staff, and giving furnace front operation signals and raw material early warning signals. This early warning method fails to provide early warnings for the storage of molten iron in the furnace cylinder in combination with the blast furnace conditions, and with changes in smelting intensity, furnace front operations, etc., the early warning value of the storage of molten iron in the blast furnace cylinder is bound to change, so this early warning method is difficult to achieve scientific and effective early warnings.

[0007] In the current blast furnace production, although there are corresponding research and applications in the measurement and visualization technology of the slag iron liquid level in the furnace, it is still at the initial stage of research and development and the reading and decoding of abnormal signals, especially in the high-temperature and pressurized molten iron environment in the furnace, the existing furnace liquid level detection equipment is difficult to play a role. At present, the control of the timing of key processes such as opening and blocking the iron mouth of the blast furnace is often determined by the blast furnace operator based on the experience in front of the furnace. If the iron mouth is opened too late, it is easy to cause a large amount of slag iron to remain in the furnace and restrict the blast furnace air supply and production process. If the iron mouth is opened too early, it is easy to cause the slag iron temperature to be low and the flow rate to be small, resulting in siltation and blockage of the slag iron ditch, affecting the production organization outside the furnace. According to the amount of molten iron in the furnace, the furnace operation time can be reasonably determined, which is of great significance for the safe and stable production of the blast furnace. Summary of the invention

[0008] In view of the problems existing in the prior art, the present invention provides a closed-loop control and early warning method and system for molten iron storage in the hearth of a blast furnace, which can calculate the molten iron storage in the hearth according to the blast furnace pig iron speed and the iron tapping speed, thereby realizing closed-loop control of the blast furnace front operation.

[0009] In order to solve the above technical problems, the present invention provides the following technical solutions: a closed-loop control and early warning method for molten iron storage in a blast furnace hearth, comprising the following steps:

[0010] S1. For the target blast furnace, collect air volume data, wind pressure data, pig iron speed data, and iron tapping speed data within a preset time period, and calculate and obtain the molten iron inventory data in the furnace within the time period;

[0011] S2. Construct a furnace molten iron stock model based on the pig iron speed, the iron tapping speed, and the furnace molten iron stock; divide the storage process of molten iron in the blast furnace furnace into four stages according to the furnace molten iron stock model:

[0012] Stage 1: t1-t2 opening slow flow stage,

[0013] Stage 2: t2-t3 opening fast flow stage,

[0014] Stage 3: t3-t4 plugging buffer stage,

[0015] Stage 4: t4-t5 iron stop stage;

[0016] Among them, t1 is the taphole opening time, t2 is the time when the pig iron speed is equal to the iron tapping speed after the taphole is opened, t3 is the taphole blocking time, t4 is the time when the taphole is completely blocked and there is no iron flow, and t5 is the taphole opening time for the next furnace;

[0017] The corresponding relationship between the iron output and the iron output time is obtained according to the second and third stages. The data of the iron output in the first stage are statistically analyzed to obtain the average total iron output Q. 缓流-out ;

[0018] S3. Based on the historical data of molten iron generation and molten iron discharge, the corresponding relationship between the molten iron storage in the blast furnace hearth and the air volume and air pressure is obtained. By monitoring the molten iron storage, air pressure trend, and blast furnace air reduction action, the molten iron storage warning value and air pressure warning value are obtained to realize the monitoring and early warning of the molten iron storage and air pressure in the blast furnace;

[0019] S4. According to the furnace molten iron inventory model, the iron mouth blocking time in front of the furnace is calculated in stage 2, and the iron mouth opening time in front of the furnace is calculated in stage 4, so as to realize the iron mouth blocking warning and the furnace opening warning.

[0020] Furthermore, in the aforementioned step S1, the first calculation method of the pig iron speed is as follows: the corresponding relationship between the number of material batches and time is calculated through the action of the material flow valve and the probe, and the material speed is obtained. Based on the conservation of elements of charge and molten iron, the weight of molten iron generated by each batch of material is calculated, that is, the batch of iron. The pig iron speed is obtained by multiplying the batch of iron by the material speed.

[0021] Furthermore, in the aforementioned step S1, the second method for calculating the pig iron speed is as follows: the consumption rate of the charge in the blast furnace is obtained by laser surface scanning and radar surface scanning, and the pig iron speed is calculated in combination with the method of conservation of elements of molten iron.

[0022] Furthermore, in the aforementioned step S1, the methods for obtaining the iron tapping speed include: weighing the molten iron ladle, weighing the train track, and video monitoring of the iron flow.

[0023] Furthermore, in the aforementioned step S2, the furnace molten iron inventory model is as follows:

[0024] , in, is the molten iron inventory in the furnace, is the pig iron speed, It is the iron tapping speed.

[0025] Furthermore, in the aforementioned step S2, the corresponding relationship between the iron output and the iron output time is as follows:

[0026] f(x)=5.23*x+50.19, R2=0.93;

[0027] Among them, x represents the iron-discharging time, f(x) represents the iron-discharging amount, and R2 is the correlation coefficient.

[0028] Furthermore, the aforementioned step S4 calculates the iron hole blocking time S2 in front of the furnace as follows:

[0029] Among them, S1 is the time interval from the current moment to blast furnace t2, Q s1-out S1 is the total amount of iron discharged from the furnace during the time interval, S2 is the time interval from the iron outlet to the plugging point, is the molten iron inventory in the furnace; Calculate the taphole opening time a2 in front of the furnace as:

[0030] Among them, a2 is the time interval from the tapping, Q 预警 is the molten iron inventory warning value analyzed by historical data in step S3, Q 缓流-out It is the average total iron output in stage 1 obtained by analyzing the historical data in step S2.

[0031] Furthermore, the aforementioned step S2 also includes: using the phases 2 and 3 to obtain the corresponding relationship between the iron output and the iron output time, and the average total iron output Q of the phase 1 缓流-out The furnace iron inventory model is modified.

[0032] Another aspect of the present invention provides a blast furnace hearth molten iron storage closed-loop control and early warning system, comprising:

[0033] The molten iron stock data calculation module is used to collect air volume data, wind pressure data, pig iron speed data, and iron tapping speed data for the target blast furnace within a preset time period, and calculate the molten iron stock data in the furnace within the time period;

[0034] The hearth iron stock model building module is used to build a hearth iron stock model based on pig iron speed, iron tapping speed, and hearth iron stock; according to the hearth iron stock model, the iron storage process in the blast furnace hearth is divided into four stages:

[0035] Stage 1: t1-t2 opening slow flow stage, Stage 2: t2-t3 opening fast flow stage, Stage 3: t3-t4 blocking buffer stage,

[0036] Stage 4: t4-t5 iron stopping stage; t1 is the taphole opening time, t2 is the time when the pig iron speed is equal to the tapping speed after the taphole is opened, t3 is the taphole blocking time, t4 is the time when the taphole is completely blocked and there is no iron flow, and t5 is the taphole opening time for the next furnace;

[0037] The corresponding relationship between the iron output and the iron output time is obtained according to the second and third stages. The data of the iron output in the first stage are statistically analyzed to obtain the average total iron output Q. 缓流-out ;

[0038] The monitoring and early warning module of molten iron inventory and wind pressure obtains the corresponding relationship between the molten iron inventory and the wind volume and wind pressure in the blast furnace cylinder based on the historical data of molten iron generation and molten iron discharge. By monitoring the molten iron inventory, wind pressure trend, and blast furnace wind reduction action, the molten iron inventory early warning value and wind pressure early warning value are obtained, thus realizing the monitoring and early warning of the molten iron inventory and wind pressure in the blast furnace;

[0039] The iron mouth blockage warning module in front of the furnace and the iron mouth opening warning module in front of the furnace are used to calculate the iron mouth blockage time in front of the furnace in stage two and the iron mouth opening time in stage four according to the molten iron inventory model in the furnace cylinder, so as to realize the iron mouth blockage warning and the iron mouth opening warning in front of the furnace.

[0040] Compared with the prior art, the beneficial technical effects of the present invention using the above technical solution are as follows:

[0041] (1) In the present invention, the molten iron generation rate can be obtained by referring to various methods such as the action of the probe, the action of the material flow valve, the laser material surface scanning, the radar material surface scanning, etc. The calculation of the molten iron generation rate is diverse, so one or more of the above methods can also be used for calculation to improve the accuracy of the calculation.

[0042] (2) The furnace front operation warning in the present invention not only takes into account the influence of the slag and iron storage in the furnace, but also fully considers the influence of the pressure-volume relationship in the furnace. In particular, when the slag and iron have poor fluidity and it is difficult to tap the slag and iron, there are certain limitations in performing furnace front operations only based on the molten iron storage in the furnace. Therefore, the present invention realizes closed-loop control of the molten iron storage in the furnace combined with the furnace conditions.

[0043] (3) The present invention can effectively guide the operators to react in advance to perform furnace operations and accurately determine the key operation timings in front of the furnace, such as opening the iron mouth and blocking the iron mouth. It can not only timely dispatch the molten iron car before the iron tapping operation, but also effectively avoid the air blockage in the furnace caused by untimely iron tapping, and avoid the risk of blast furnace operation deviation caused by the subjective will and judgment of the blast furnace operators.

[0044] (4) The present invention divides the molten iron inventory in the furnace into stages and proposes a corresponding relationship y=f(s) between the iron output and the iron output time, which is of great significance for accurately warning the furnace opening time and the plugging time. In addition, the early warning monitoring model can continuously correct the y=f(s) function based on the model data to improve the accuracy of the model; it can effectively deal with the deviation of the early warning model caused by changes in external conditions such as furnace conditions, smelting intensity, and opening diameter. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Schematic diagram of the method framework in the present invention.

[0046] Figure 2 It is a curve chart showing the stages of molten iron inventory in a blast furnace over a certain period of time.

[0047] Figure 3 It is a scatter diagram corresponding to the iron tapping amount and the iron tapping time in the open fast flow stage of the present invention.

[0048] Figure 4 It is a columnar distribution diagram of the iron output in the open slow flow stage of the present invention.

[0049] Figure 5 This is a curve chart showing the corresponding molten iron inventory and furnace conditions in the blast furnace over a certain period of time.

[0050] Figure 6 It is a schematic diagram of early warning for a certain period of time of the present invention. DETAILED DESCRIPTION

[0051] In order to better understand the technical content of the present invention, specific embodiments are given and described as follows in conjunction with the accompanying drawings.

[0052] Various aspects of the invention are described herein with reference to the accompanying drawings, in which many illustrative embodiments are shown. The embodiments of the invention are not limited to those described in the accompanying drawings. It should be understood that the invention is implemented by any of the various concepts and embodiments described above, as well as the concepts and embodiments described in detail below, because the concepts and embodiments disclosed in the invention are not limited to any implementation. In addition, some aspects disclosed in the invention may be used alone or in any appropriate combination with other aspects disclosed in the invention.

[0053] refer to Figure 1 The present invention provides a closed-loop control and early warning method for molten iron storage in a blast furnace hearth, comprising the following steps:

[0054] S1. For the target blast furnace, the air volume data, wind pressure data, pig iron speed data, and iron tapping speed data are collected within a preset time period, and the molten iron inventory data in the furnace during the time period is calculated.

[0055] The pig iron speed data can be obtained through the existing material flow valve action and the probe action; the material flow valve action and the probe action can calculate the corresponding relationship between the number of material batches and time to obtain the material speed; based on the element conservation of charge and molten iron, the weight of the molten iron generated by each batch of material is calculated, referred to as batch iron, and the pig iron speed is the product of the batch iron and the material speed.

[0056] Pig iron speed data can also be obtained through laser material surface scanning, radar scanning and other methods, that is, through related equipment and methods, to obtain the consumption rate of the charge in the blast furnace, and combined with the method of element conservation of molten iron. It is also possible to use one or more of the above methods to calculate the molten iron generation rate at the same time to improve the accuracy of the calculation.

[0057] The iron tapping speed data can be obtained through methods such as ladle weighing, train track weighing, and iron flow video monitoring.

[0058] S2. Construct a furnace iron stock model based on pig iron speed, iron tapping speed, and furnace iron stock:

[0059] The furnace molten iron inventory model is as follows: , in, is the molten iron inventory in the furnace, is the pig iron speed, It is the iron tapping speed.

[0060] Based on the data curve of molten iron inventory in the furnace formed by the historical data of pig iron speed and iron tapping speed, the corresponding relationship between iron tapping time and iron tapping amount in different stages is explored. Figure 2 As shown in the figure, according to the furnace molten iron inventory model, the storage process of molten iron in the blast furnace hearth is divided into four stages:

[0061] Stage 1: t1-t2 opening slow flow stage, in this stage the taphole has just been opened, the iron flow rate is low, the molten iron stock in the furnace increases slowly, and the iron tapping rate is lower than the pig iron rate.

[0062] Stage 2: t2-t3 open fast flow stage, during which the iron tapping rate is greater than the pig iron rate, the molten iron stock in the furnace gradually decreases, and this stage ends when the iron outlet is blocked.

[0063] Stage three: t3-t4 plugging buffer stage, during which the iron tapping speed is lower than the pig iron speed, the iron flow gradually decreases, and the molten iron stock in the furnace gradually increases until the iron tapping is completed.

[0064] Stage 4: t4-t5 iron-stopping stage, during which the iron mouth is in a blocked state, no iron is tapped, and the molten iron stock in the furnace increases rapidly.

[0065] Among them, t1 is the time for opening the iron mouth, t2 is the time when the pig iron speed is equal to the iron tapping speed after the iron mouth is opened, t3 is the time for blocking the iron mouth, t4 is the time when the iron mouth is completely blocked and there is no iron flow, and t5 is the time for opening the iron mouth of the next furnace; the calculation of the molten iron inventory in the present invention takes time t2 as the starting point, that is, the theoretical lowest point of the molten iron inventory.

[0066] According to the corresponding relationship between the iron output and the iron output time obtained in stage 2 and stage 3, early warning is provided for the critical time of opening and blocking the iron mouth in front of the blast furnace. The interception volume is 2680m 3 The relevant data between the iron-out time and iron-out amount of the blast furnace from June 20, 2023 to November 15, 2023, such as Figure 3 The corresponding relationship between the tapping time and the tapping amount in the second stage shown in the figure has an obvious linear relationship, and the fitting equation is: f(x)=5.23*x+50.19, R2=0.93, where x represents the tapping time, f(x) represents the tapping amount, and R2 is the correlation coefficient.

[0067] Statistical analysis is performed on the iron output in stage 1 to determine the average total iron output Q in this stage. 缓流-out .like Figure 4 The volume shown is 2680m 3 The total amount of iron produced during the slow flow stage of the blast furnace opening is 18t.

[0068] S3. Based on the historical data of molten iron generation and discharge, the corresponding relationship between the molten iron storage in the blast furnace hearth and the air volume and wind pressure is obtained. By monitoring the molten iron storage, wind pressure trend, and blast furnace wind reduction action, the molten iron storage warning value and wind pressure warning value are obtained to realize the monitoring and early warning of the molten iron storage and wind pressure in the blast furnace.

[0069] Too much molten iron in the furnace will inevitably lead to an increase in the wind pressure in the furnace, resulting in a tense relationship between pressure and volume, which will affect the furnace condition. By monitoring the historical data of the blast furnace, the warning value of the molten iron in the blast furnace and the wind pressure warning value can be determined. 3 For example, the blast furnace Figure 5 As shown in the figure, at around 10:33, the molten iron stock in the furnace exceeded 100t, the blast furnace opening operation was obviously not timely, and the wind pressure had a clear upward trend, exceeding 440KPa, affecting the smooth operation of the blast furnace. The blast furnace was forced to reduce the air flow by 100m3 / min twice in a row. Through multiple monitoring of historical data, the molten iron stock warning value Q was determined. 预警 The load capacity is 100t and the wind pressure warning value is 428KPa.

[0070] S4. According to the furnace molten iron inventory model, the furnace front iron mouth blocking time is calculated in stage 2, and the furnace front iron mouth opening time is calculated in stage 4, so as to realize the furnace front iron mouth blocking warning and furnace front opening warning, as follows:

[0071] The calculation of the iron mouth blocking time S2 in front of the furnace is as follows:

[0072]

[0073] Among them, S1 is the time interval from the current moment to blast furnace t2, Q s1-out S1 is the total amount of iron discharged from the furnace during the time interval, S2 is the time interval from the iron outlet to the plugging point, It is the amount of molten iron in the furnace.

[0074] Calculate the taphole opening time a2 in front of the furnace as:

[0075]

[0076] Among them, a2 is the time interval from the tapping, Q 预警 is the molten iron inventory warning value analyzed by historical data in step S3, Q 缓流-out It is the average total iron output in stage 1 obtained by analyzing the historical data in step S2.

[0077] like Figure 6 As shown, it is a schematic diagram of the furnace opening warning at a certain stage in the embodiment. In order to further avoid the poor fluidity of slag iron in the furnace, which leads to the unsmooth discharge of slag iron in multiple furnaces, when the molten iron discharge speed is lower than the molten iron generation speed, the blast furnace wind pressure is set to rise to the wind pressure warning value and then a warning is issued, prompting to open the iron mouth to discharge slag iron. The third step in the embodiment determines the molten iron inventory warning value Q 预警 The wind pressure warning value is 428KPa, so it reaches the critical value, prompting the blast furnace to tap iron in time and reduce the wind speed by 100m3 / min.

[0078] The fitting relationship between the tapping amount and tapping time at different stages and the total tapping amount at the slow flow stage of the opening may change with changes in smelting intensity, changes in furnace operations, and changes in the opening diameter. Therefore, the corresponding relationship between the tapping amount and the tapping time and Q can be selected as the data basis for the past six months or one year. 缓流-out Make regular or real-time corrections to continuously improve the accuracy of early warnings.

[0079] Another aspect of the present invention provides a blast furnace hearth molten iron storage closed-loop control and early warning system, comprising:

[0080] The molten iron stock data calculation module is used to collect air volume data, wind pressure data, pig iron speed data, and iron tapping speed data for the target blast furnace within a preset time period, and calculate the molten iron stock data in the furnace within the time period;

[0081] The hearth iron stock model building module is used to build a hearth iron stock model based on pig iron speed, iron tapping speed, and hearth iron stock; according to the hearth iron stock model, the iron storage process in the blast furnace hearth is divided into four stages:

[0082] Stage 1: t1-t2 opening slow flow stage, Stage 2: t2-t3 opening fast flow stage, Stage 3: t3-t4 blocking buffer stage,

[0083] Stage 4: t4-t5 iron stopping stage; t1 is the taphole opening time, t2 is the time when the pig iron speed is equal to the tapping speed after the taphole is opened, t3 is the taphole blocking time, t4 is the time when the taphole is completely blocked and there is no iron flow, and t5 is the taphole opening time for the next furnace;

[0084] The corresponding relationship between the iron output and the iron output time is obtained according to the second and third stages. The data of the iron output in the first stage are statistically analyzed to obtain the average total iron output Q. 缓流-out ;

[0085] The monitoring and early warning module of molten iron inventory and wind pressure obtains the corresponding relationship between the molten iron inventory and the wind volume and wind pressure in the blast furnace cylinder based on the historical data of molten iron generation and molten iron discharge. By monitoring the molten iron inventory, wind pressure trend, and blast furnace wind reduction action, the molten iron inventory early warning value and wind pressure early warning value are obtained, thus realizing the monitoring and early warning of the molten iron inventory and wind pressure in the blast furnace;

[0086] The iron mouth blockage warning module in front of the furnace and the iron mouth opening warning module in front of the furnace are used to calculate the iron mouth blockage time in front of the furnace in stage two and the iron mouth opening time in stage four according to the molten iron inventory model in the furnace cylinder, so as to realize the iron mouth blockage warning and the iron mouth opening warning in front of the furnace.

[0087] Although the present invention has been described above with preferred embodiments, it is not intended to limit the present invention. A person skilled in the art of the present invention may make various modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the definition of the claims.

Claims

1. A closed-loop control and early warning method for molten iron storage in a blast furnace hearth, characterized in that: The following steps are involved: S1. For the target blast furnace, collect air volume data, wind pressure data, pig iron speed data, and iron tapping speed data within a preset time period, and calculate and obtain the molten iron inventory data in the furnace during the time period; S2. Construct a furnace molten iron stock model based on the pig iron speed, the iron tapping speed, and the furnace molten iron stock; divide the storage process of molten iron in the blast furnace furnace into four stages according to the furnace molten iron stock model: Stage 1: t1-t2 opening slow flow stage, Stage 2: t2-t3 opening fast flow stage, Stage 3: t3-t4 plugging buffer stage, Stage 4: t4-t5 iron stop stage; Among them, t1 is the taphole opening time, t2 is the time when the pig iron speed is equal to the iron tapping speed after the taphole is opened, t3 is the taphole blocking time, t4 is the time when the taphole is completely blocked and there is no iron flow, and t5 is the taphole opening time for the next furnace; The corresponding relationship between the iron output and the iron output time is obtained according to the second and third stages. The data of the iron output in the first stage are statistically analyzed to obtain the average total iron output Q. 缓流-out ; S3. Based on the historical data of molten iron generation and molten iron discharge, the corresponding relationship between the molten iron storage in the blast furnace hearth and the air volume and air pressure is obtained. By monitoring the molten iron storage, air pressure trend, and blast furnace air reduction action, the molten iron storage warning value and air pressure warning value are obtained to realize the monitoring and early warning of the molten iron storage and air pressure in the blast furnace; S4. According to the furnace molten iron inventory model, the iron mouth blocking time in front of the furnace is calculated in stage 2, and the iron mouth opening time in front of the furnace is calculated in stage 4, so as to realize the iron mouth blocking warning and the furnace opening warning.

2. A blast furnace hearth molten iron storage closed-loop control and early warning method according to claim 1, characterized in that: In step S1, the first calculation method of the pig iron speed is as follows: the corresponding relationship between the number of material batches and time is calculated through the action of the material flow valve and the probe, and the material speed is obtained. Based on the conservation of elements of charge and molten iron, the weight of molten iron generated by each batch of material is calculated, that is, the batch of iron. The pig iron speed is obtained by multiplying the batch of iron by the material speed.

3. A blast furnace hearth molten iron storage closed-loop control and early warning method according to claim 1, characterized in that: In step S1, the second method for calculating the pig iron speed is as follows: the consumption rate of the charge in the blast furnace is obtained by laser material surface scanning and radar material surface scanning methods, and the pig iron speed is calculated by combining the method of element conservation of molten iron.

4. A blast furnace hearth molten iron storage closed-loop control and early warning method according to claim 1, characterized in that: In step S1, the methods for obtaining the iron tapping speed include: weighing the molten iron ladle, weighing the train track, and video monitoring of the iron flow.

5. A blast furnace hearth molten iron storage closed-loop control and early warning method according to claim 1, characterized in that: In step S2, the furnace molten iron inventory model is as follows: ， in, is the molten iron inventory in the furnace, is the pig iron speed, It is the iron tapping speed.

6. A blast furnace hearth molten iron storage closed-loop control and early warning method according to claim 1, characterized in that: In step S2, the corresponding relationship between the iron output and the iron output time is as follows: f(x)=5.23*x+50.19, R2=0.93; Among them, x represents the iron-discharging time, f(x) represents the iron-discharging amount, and R2 is the correlation coefficient.

7. A closed-loop control and early warning method for molten iron storage in a blast furnace hearth according to claim 5, characterized in that: Step S4 calculates the furnace front iron mouth blocking time S2 as follows: ， Among them, S1 is the time interval from the current moment to blast furnace t2, S1 is the total amount of iron discharged from the furnace during the time interval, S2 is the time interval from the iron outlet to the plugging point, is the molten iron inventory in the furnace; Calculate the taphole opening time a2 in front of the furnace as: ， Among them, a2 is the time interval from the tapping, Q 预警 is the molten iron inventory warning value analyzed by historical data in step S3, Q 缓流-out It is the average total iron output in stage 1 obtained by analyzing the historical data in step S2.

8. A blast furnace hearth molten iron storage closed-loop control and early warning method according to claim 1, characterized in that: Step S2 also includes: using the second and third stages to obtain the corresponding relationship between the amount of iron produced and the time of iron production, and the average total amount of iron produced in the first stage Q 缓流-out The furnace iron inventory model is modified.

9. A blast furnace hearth molten iron storage closed-loop control and early warning system, characterized in that: include: The molten iron stock data calculation module is used to collect air volume data, wind pressure data, pig iron speed data, and iron tapping speed data for the target blast furnace within a preset time period, and calculate the molten iron stock data in the furnace within the time period; The hearth iron stock model building module is used to build a hearth iron stock model based on pig iron speed, iron tapping speed, and hearth iron stock; according to the hearth iron stock model, the iron storage process in the blast furnace hearth is divided into four stages: Stage 1: t1-t2 opening slow flow stage, Stage 2: t2-t3 opening fast flow stage, Stage 3: t3-t4 blocking buffer stage, Stage 4: t4-t5 iron stopping stage; t1 is the taphole opening time, t2 is the time when the pig iron speed is equal to the tapping speed after the taphole is opened, t3 is the taphole blocking time, t4 is the time when the taphole is completely blocked and there is no iron flow, and t5 is the taphole opening time for the next furnace; The corresponding relationship between the iron output and the iron output time is obtained according to the second and third stages. The data of the iron output in the first stage are statistically analyzed to obtain the average total iron output Q. 缓流-out ; The monitoring and early warning module of molten iron inventory and wind pressure obtains the corresponding relationship between the molten iron inventory and the wind volume and wind pressure in the blast furnace cylinder based on the historical data of molten iron generation and molten iron discharge. By monitoring the molten iron inventory, wind pressure trend, and blast furnace wind reduction action, the molten iron inventory early warning value and wind pressure early warning value are obtained, thus realizing the monitoring and early warning of the molten iron inventory and wind pressure in the blast furnace; The iron mouth blockage warning module in front of the furnace and the iron mouth opening warning module in front of the furnace are used to calculate the iron mouth blockage time in front of the furnace in stage two and the iron mouth opening time in stage four according to the molten iron inventory model in the furnace cylinder, so as to realize the iron mouth blockage warning and the iron mouth opening warning in front of the furnace.

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