A Closed-Loop Control and Early Warning Method and System for Molten Iron Storage in a Blast Furnace Hearth

Abstract

The present invention provides a closed-loop control and early warning method and system for molten iron storage in a blast furnace hearth. The method of the present invention includes constructing a molten iron inventory model in the hearth based on real-time acquisition of data such as air volume, air pressure, pig iron speed, and tapping speed by blast furnace intelligent monitoring technology. Then, the molten iron storage volume in the blast furnace is divided into four stages: the opening slow flow stage, the opening fast flow stage, the taphole buffering stage, and the iron stoppage stage. Based on the relevant data of the four stages, the corresponding relationship between tapping time and tapping volume is explored, and the corresponding relationship between molten iron inventory and furnace pressure is analyzed to determine the molten iron inventory early warning value, pressure early warning value, etc. Based on the regression equation of tapping time and tapping volume, considering the pressure-volume relationship in the furnace, early warning is carried out for the opening and taphole plugging operations in front of the furnace. The present invention is of great significance for the reasonable and scientific control of the operations in front of the furnace, and realizes the closed-loop control of the operations in front of the blast furnace hearth.

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 with the patent application number 201610088993.1 and the name "Blast Furnace Hot Metal Output Estimation Device and Method" includes a correlation determination module and a calculation module. The correlation determination module includes a liquid level height unit and a determination quantity unit. The liquid level height unit reads the liquid level height on the blast furnace side, and the determination quantity unit reads the determined quantity of each ladle of hot metal on the steelmaking side. The correlation determination module calculates the corresponding relationship between the hot metal liquid level height and the determined quantity of hot metal based on the data of the liquid level height unit and the determination quantity unit. The calculation module includes a hot metal output estimation unit and a hot metal output correction unit. The hot metal output unit reads the actual liquid level height inside the torpedo car, substitutes the actual liquid level height into the corresponding relationship between the hot metal liquid level height and the determined quantity of hot metal, and obtains the actual determined quantity of hot metal inside the torpedo car. The hot metal output correction unit corrects the corresponding relationship between the hot metal liquid level height and the determined quantity of hot metal according to the actual determined quantity of hot metal. This patent does not give the calculation methods for key parameters such as the theoretical pig iron quantity and the theoretical slag quantity, and ignores the role of slag in the blast furnace smelting process. Iron in the blast furnace raw materials not only enters the hot metal, but also a part enters the slag. Therefore, the calculation method of this patent is difficult to reflect the actual situation.

[0005] The patent application with the patent application number 201610880421.7 and the name "Method and Device for Online Measuring the Information of the Slag-Iron Liquid Level in the Blast Furnace Hearth" uses the high-precision electromotive force signal generated by the electromotive force measurement point as the measurement parameter. The computer system performs program code analysis on the data of different tuyeres and different tapping holes to obtain the liquid level and dead stock column information of the hearth. The measurement basis is the change in the heat transfer of the refractory and the furnace shell of the hearth caused by the different heat storage capacities of the slag and iron. The measured value is the heat transferred by the refractory and the furnace shell. The computer system responsible for code processing serves as a data visualization system. The inside of the electromotive force measurement point consists of a resistor, a measurement probe, and a circuit, and directly analyzes and calculates the electromotive force generated by each electromotive force measurement point. This patent does not consider the electromotive force deviation caused by the uneven change of the hearth due to hearth erosion. With the production of the blast furnace, irregular erosion and deformation occur inside the hearth, such as "elephant foot shape", especially this phenomenon is more significant in the later stage of the furnace campaign. Therefore, it is difficult to truly reflect the change of the hearth liquid level using the electromotive force signal.

[0006] The patent application with the patent application number 202311030145.1 and the name of a monitoring system and method for the slag-iron storage volume in the blast furnace hearth includes a raw material system, a slag-iron system, a processing system, and an early warning system. The method includes determining the chemical components in the raw materials; formulating a burden distribution system during the charging process of the blast furnace, recording the action time of the sounding rod and the weight of each batch of materials; determining the tapping speed, tapping weight-related data; determining the slag tapping speed, slag tapping weight-related data; chemically detecting the molten iron and slag; screening and processing the data fed back from the raw material system and the slag-iron system; grading and warning the data in the processing system, giving early warnings to the front-line operation staff, and giving tapping operation signals and raw material early warning signals. This early warning method fails to give early warnings to the molten iron inventory in the hearth in combination with the blast furnace condition, and with the changes in the smelting intensity, tapping operations, etc., the early warning value of the molten iron storage in the blast furnace hearth is bound to change. Therefore, it is difficult for this early warning method to achieve scientific and effective early warning.

[0007] In the current blast furnace production, although there are corresponding researches and applications in the measurement and visualization technology of the slag-iron liquid level in the hearth, it still only stays in the initial R & D and the reading and decoding of abnormal signals. Especially in the high-temperature and pressure iron water environment in the hearth, the existing hearth liquid level detection equipment is difficult to play a role. At present, the control of the key processes such as opening the taphole and plugging the taphole of the blast furnace often depends on the judgment of the blast furnace operators according to the tapping experience. If the taphole is opened too late, a large amount of slag and iron will easily stay in the hearth, restricting the blast furnace blowing and commissioning process. If the taphole is opened too early, the slag and iron will have low temperature and small flow rate, resulting in the siltation and blockage of the slag-iron channel, affecting the out-of-furnace production organization. Reasonably determining the tapping operation time based on the molten iron storage in the hearth 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 the molten iron storage in the blast furnace hearth, which can calculate the molten iron inventory in the hearth based on the pig iron speed and tapping speed of the blast furnace, and realizes the closed-loop control of the blast furnace tapping operation.

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

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

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

[0012] Stage 1: The opening slow flow stage from t1 to t2,

[0013] Stage 2: The opening fast flow stage from t2 to t3,

[0014] Stage 3: The plugging buffer stage from t3 to t4,

[0015] Stage 4: The iron stoppage stage from t4 to t5;

[0016] Among them, 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 plugging time, t4 is the time when the taphole is completely plugged and there is no iron flow, and t5 is the taphole opening time of the next furnace;

[0017] According to the corresponding relationship between the tapping volume and the tapping time obtained in Stage 2 and Stage 3, and based on the tapping volume in Stage 1, data statistical analysis is carried out to obtain the average total tapping volume Q 缓流-out ;

[0018] S3. Based on the historical data of hot metal generation and hot metal discharge, obtain the corresponding relationship between the hot metal storage volume in the blast furnace hearth and the blast volume and blast pressure. By monitoring the hot metal storage volume, the trend of blast pressure, and the blast reduction operation of the blast furnace, obtain the hot metal storage volume warning value and the blast pressure warning value, and realize the monitoring and warning of the hot metal storage volume and blast pressure in the blast furnace;

[0019] S4. According to the hearth hot metal storage volume model, calculate the taphole plugging time in front of the furnace in Stage 2 and calculate the taphole opening time in front of the furnace in Stage 4, and realize the warning of taphole plugging in front of the furnace and the warning of taphole opening in front of the furnace.

[0020] Furthermore, in the aforementioned step S1, the first calculation method of the pig iron speed is as follows: Obtain the corresponding relationship between the number of batches of materials and time by calculating the actions of the material flow valve and the sounding rod to obtain the material speed. Based on the element conservation of the burden and hot metal, calculate the weight of the hot metal generated per batch of materials, that is, the batch iron. Multiply the batch iron by the material speed to obtain the pig iron speed.

[0021] Furthermore, in the aforementioned step S1, the second calculation method of the pig iron speed is as follows: Obtain the consumption speed of the burden in the blast furnace by means of laser burden surface scanning and radar burden surface scanning methods, and calculate the pig iron speed by combining the method of element conservation of hot metal.

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

[0023] Furthermore, in the aforementioned step S2, the hearth hot metal storage volume model is as follows:

[0024] Q iron =∫(v iron-in -v iron-out )dt,

[0025] Among them, Q iron is the molten iron inventory in the hearth, v iron-in is the pig iron speed, v iron-out is the tapping speed.

[0026] Further, in the aforementioned step S2, the correspondence between the tapping volume and the tapping time is as follows:

[0027] f(x) = 5.23 * x + 50.19,

[0028] where x represents the tapping time and f(x) represents the tapping volume.

[0029] Further, the aforementioned step S4 calculates the time for plugging the iron notch in front of the furnace as follows:

[0030] v iron-in * s2 - (f(s1 + s2) - Q s1-out ) = Q iron

[0031] where S1 is the time interval from the current moment to the blast furnace t2, Q s1-out is the total tapping volume in front of the furnace during the S1 time interval, S2 is the time interval from the current moment to plugging the iron notch, Q iron is the molten iron inventory in the hearth;

[0032] The time a2 for opening the iron notch in front of the furnace is calculated as:

[0033] v iron-in * a2 + Q iron = Q 预警 - Q 缓流-out

[0034] where a2 is the time interval from the current moment to opening the iron notch, Q 预警 is the early warning value of the molten iron inventory obtained from the historical data analysis in step S3, Q 缓流-out is the average total tapping volume in the first stage obtained from the historical data analysis in step S2.

[0035] Further, the aforementioned step S2 further includes: obtaining the correspondence between the tapping volume and the tapping time using the second stage and the third stage, and the average total tapping volume Q 缓流-out to correct the molten iron inventory model in the hearth.

[0036] On the other hand, the present invention provides a closed-loop control and early warning system for molten iron storage in the hearth of a blast furnace, including:

[0037] A molten iron inventory data calculation module, configured to collect air volume data, air pressure data, pig iron speed data, and tapping speed data for a target blast furnace within a preset time period, and calculate the molten iron inventory data in the hearth during this time period;

[0038] The hearth molten iron inventory model construction module is used to construct a hearth molten iron inventory model based on the pig iron speed, tapping speed, and hearth molten iron inventory; according to the hearth molten iron inventory model, the storage process of molten iron in the blast furnace hearth is divided into four stages:

[0039] Stage 1: The slow-flow stage with the taphole open from t1 to t2, Stage 2: The fast-flow stage with the taphole open from t2 to t3, Stage 3: The buffer stage with the taphole plugged from t3 to t4,

[0040] Stage 4: The iron stop stage from t4 to t5; where t1 is the taphole opening time, t2 is the time when the pig iron speed equals the tapping speed after the taphole is opened, t3 is the taphole plugging time, t4 is the time when there is no iron flow after the taphole is completely plugged, and t5 is the taphole opening time for the next furnace;

[0041] Obtain the corresponding relationship between the tapping volume and tapping time according to Stage 2 and Stage 3, and conduct data statistical analysis based on the tapping volume in Stage 1 to obtain the average total tapping volume Q 缓流-out ;

[0042] The monitoring and early warning module for molten iron inventory and blast pressure is based on the historical data of molten iron generation and discharge, obtains the corresponding relationship between the molten iron storage volume, air volume, and blast pressure in the blast furnace hearth, and realizes the monitoring and early warning of the molten iron inventory and blast pressure in the blast furnace by monitoring the molten iron inventory, blast pressure trend, and blast reduction actions of the blast furnace;

[0043] The taphole plugging early warning and taphole opening early warning module in front of the furnace is used to calculate the taphole plugging time in front of the furnace in Stage 2 and calculate the taphole opening time in front of the furnace in Stage 4 according to the hearth molten iron inventory model, so as to realize the taphole plugging early warning and taphole opening early warning in front of the furnace.

[0044] Compared with the prior art, the beneficial technical effects of the present invention adopting the above technical solutions are as follows:

[0045] (1) In the present invention, the molten iron generation speed can be obtained by referring to various methods such as sounding rod movement, material flow valve movement, laser burden surface scanning, and radar burden surface scanning. The calculation of the molten iron generation speed has diversity, so one or more of the above methods can also be used for calculation to improve the calculation accuracy.

[0046] (2) The tapping operation early warning in the present invention not only takes into account the influence of the slag and iron storage volume in the furnace, but also fully considers the influence of the pressure-volume relationship in the furnace. Especially when the slag and iron fluidity is poor and it is difficult to discharge slag and iron, it has certain limitations to only carry out tapping operations based on the hearth molten iron inventory. Therefore, the present invention realizes the closed-loop control of the hearth molten iron storage combined with the furnace condition.

[0047] (3) The present invention can effectively guide operators to make early responses for pre-furnace operation tasks, accurately determine the key operation timing in front of the furnace such as tapping and stopping the taphole. It can not only timely dispatch the molten iron ladle in advance before the tapping operation, but also effectively avoid the air backpressure in the furnace caused by untimely tapping, and avoid the risk of blast furnace operation deviation caused by the subjective judgment of blast furnace operators.

[0048] (4) Through the stage division of the molten iron inventory in the hearth, the present invention proposes the corresponding relationship y = f(s) between the tapping volume and the tapping time, which is of great significance for accurately warning the tapping opening time and plugging time in front of the furnace. And this warning and monitoring model can continuously correct the y = f(s) function according to the model data to improve the accuracy of the model; it can effectively cope with the deviation of the warning model caused by changes in external conditions such as furnace conditions, smelting intensity, and opening diameter. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a schematic diagram of the method framework in the present invention.

[0050] Figure 2 It is a curve graph of the stage division of the molten iron inventory in a blast furnace for a certain period of time.

[0051] Figure 3 It is a scatter plot of the tapping volume and the tapping time in the fast-flow stage of opening in the present invention.

[0052] Figure 4 It is a bar distribution graph of the tapping volume in the slow-flow stage of opening in the present invention.

[0053] Figure 5 It is a curve graph of the molten iron inventory and the furnace conditions in a blast furnace for a certain period of time.

[0054] Figure 6 It is a warning schematic diagram for a certain period of time in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0055] In order to better understand the technical content of the present invention, specific embodiments are hereby given and described in conjunction with the accompanying drawings as follows.

[0056] In the present invention, various aspects of the present invention are described with reference to the accompanying drawings, and many illustrative embodiments are shown in the drawings. The embodiments of the present invention are not limited to those described in the drawings. It should be understood that the present invention can be implemented by any one of the various concepts and embodiments introduced above, and the various concepts and embodiments described in detail below, because the concepts and embodiments disclosed in the present invention are not limited to any embodiment. In addition, some aspects disclosed in the present invention can be used alone, or in any appropriate combination with other aspects disclosed in the present invention.

[0057] Reference Figure 1, the present invention provides a closed-loop control and warning method for the molten iron storage in the blast furnace hearth, including the following steps:

[0058] S1. For the target blast furnace, collect the air volume data, air pressure data, pig iron speed data, and tapping speed data within a preset time period, and calculate the molten iron stock data in the hearth during this time period.

[0059] The pig iron speed data can be obtained through the existing actions of the material flow valve and the sounding rod; the actions of the material flow valve and the sounding rod can calculate the corresponding relationship between the number of material batches and time to obtain the material speed; based on the element conservation of the burden and molten iron, calculate the weight of the molten iron generated per batch of material, simply referred to as batch iron, and the product of batch iron and the material speed is the pig iron speed.

[0060] The pig iron speed data can also be obtained through methods such as laser burden surface scanning and radar scanning, that is, through relevant equipment and methods, obtain the consumption speed of the burden in the blast furnace, and combine with the method of element conservation of molten iron to obtain it. One or more of the above methods can also be used to calculate the molten iron generation speed simultaneously to improve the accuracy of the calculation.

[0061] The tapping speed data can be obtained through methods such as molten iron ladle weighing, train track weighing, and molten iron flow video monitoring.

[0062] S2. Construct a molten iron stock model in the hearth based on the pig iron speed, tapping speed, and molten iron stock in the hearth:

[0063] The molten iron stock model in the hearth is as follows:

[0064] Q iron =∫(v iron-in -v iron-out )dt,

[0065] where Q iron is the molten iron stock in the hearth, v iron-in is the pig iron speed, and v iron-out is the tapping speed.

[0066] Based on the molten iron stock data curve formed by the historical data of the pig iron speed and the tapping speed, explore the corresponding relationship between the tapping time and the tapping amount in different stages. As Figure 2 shown, according to the molten iron stock model in the hearth, the molten iron storage process in the blast furnace hearth is divided into four stages:

[0067] Stage 1: The opening slow flow stage from t1 to t2. In this stage, the iron notch is just opened, the iron flow speed is small, the molten iron stock in the hearth increases slowly, and the tapping speed is less than the pig iron speed.

[0068] Stage 2: The rapid flow stage with an open taphole from t2 to t3. During this stage, the tapping speed is greater than the pig iron production speed, and the molten iron inventory in the hearth gradually decreases. This stage ends when the taphole is blocked.

[0069] Stage 3: The buffer stage with a blocked taphole from t3 to t4. During this stage, the tapping speed is less than the pig iron production speed, the iron flow gradually decreases, and the molten iron inventory in the hearth gradually increases until the tapping ends.

[0070] Stage 4: The iron stoppage stage from t4 to t5. During this stage, the taphole is in a blocked state, no tapping is carried out, and the molten iron inventory in the hearth increases rapidly.

[0071] Among them, t1 is the time to open the taphole, t2 is the time when the pig iron production speed is equal to the tapping speed after the taphole is opened, t3 is the time to block the taphole, t4 is the time when the taphole is completely blocked and there is no iron flow, and t5 is the time to open the taphole for the next furnace; in the present invention, the calculation of the molten iron inventory starts from the moment of t2, that is, the theoretical lowest point of the molten iron inventory.

[0072] Based on Stage 2 and Stage 3, obtain the corresponding relationship between the tapping volume and the tapping time, and give early warnings for the critical moments of opening and blocking the taphole in front of the blast furnace hearth. Intercept the relevant data between the tapping time and the tapping volume of the blast furnace with a volume of 2680m 3 from June 20, 2023 to November 15, 2023. As Figure 3 shown, the corresponding relationship between the tapping time and the tapping volume in Stage 2 has an obvious linear relationship, and the fitting equation is: f(x)

[0073] = 5.23 * x + 50.19, where x represents the tapping time and f(x) represents the tapping volume.

[0074] Conduct data statistical analysis on the tapping volume in Stage 1 to determine the average total tapping volume Q 缓流-out in this stage. As Figure 4 shown, the total tapping volume in the slow flow stage with an open taphole of the blast furnace with a volume of 2680m 3 is 18t.

[0075] S3. Based on the historical data of molten iron generation and molten iron discharge, obtain the corresponding relationship between the molten iron inventory in the blast furnace hearth and the air volume and air pressure. By monitoring the molten iron inventory, the air pressure trend, and the blast furnace air reduction operation, obtain the early warning value of the molten iron inventory and the early warning value of the air pressure, and realize the monitoring and early warning of the molten iron inventory and the air pressure in the blast furnace.

[0076] Too much molten iron inventory in the hearth will inevitably lead to an increase in the air pressure in the furnace, a tense pressure-volume relationship, and affect the smooth operation of the furnace condition; by monitoring the historical data of the blast furnace, determine the early warning value of the molten iron inventory in the blast furnace hearth and the early warning value of the air pressure. Taking the blast furnace with a volume of 2680m 3 as an example, as Figure 5As shown, at around 10:33, the molten iron inventory in the hearth exceeded 100t. The operation of opening the tuyere in front of the blast furnace was significantly untimely, and the blast pressure showed an obvious upward trend, exceeding 440 KPa, which affected the smooth operation of the blast furnace. The blast furnace was forced to reduce the blast twice continuously by 100 m3 / min. Through multiple monitoring of historical data, the early warning value Q-warning of the molten iron inventory was determined to be 100t, and the early warning value of the blast pressure was 428 KPa.

[0077] S4. According to the hearth molten iron inventory model, calculate the time to plug the taphole in front of the furnace in stage two and the time to open the taphole in front of the furnace in stage four to achieve early warning of plugging the taphole in front of the furnace and early warning of opening the taphole, as follows:

[0078] The time to plug the taphole in front of the furnace is calculated as follows:

[0079] v iron-in *s2-(f(s1 + s2)-Q s1-out ) = Q iron

[0080] Wherein, S1 is the time interval from the current moment to the blast furnace t2, Q s1-out is the total amount of tapping in front of the furnace during the S1 time interval, S2 is the time interval from the taphole, and Q iron is the molten iron inventory in the hearth.

[0081] The time a2 to open the taphole in front of the furnace is calculated as:

[0082] v iron-in *a2 + Q iron = Q 预警 -Q 缓流-out

[0083] Wherein, a2 is the time interval from the taphole, Q 预警 is the early warning value of the molten iron inventory analyzed from historical data in step S3, and Q 缓流-out is the average total tapping amount in stage one analyzed from historical data in step S2.

[0084] As Figure 6 shown, it is a schematic diagram of early warning of opening the taphole in front of the furnace in a certain stage of the embodiment. Further, to avoid poor fluidity of slag and molten iron in the hearth, resulting in unsmooth discharge of slag and molten iron in multiple consecutive furnaces, when the discharge speed of molten iron is less than the generation speed of molten iron, it is set that after the blast pressure of the blast furnace rises to the early warning value, an early warning is also given to prompt opening the taphole to discharge slag and molten iron. In the embodiment, the early warning value Q 预警 of the molten iron inventory determined in the third step is 100t, and the early warning value of the blast pressure is 428 KPa. Therefore, when the critical value is reached, the blast furnace is prompted to tap iron in time and an operation of reducing the blast by 100 m3 / min is carried out.

[0085] The fitting relationship between the tapping volume and tapping time at different stages, and the total tapping volume in the slow-flow stage after opening the taphole may change with the change of smelting intensity, front-of-furnace operation, and taphole diameter. Therefore, the corresponding relationship between the tapping volume and tapping time in the past six months or one year can be selected as the data basis and Q 缓流-out Perform regular or real-time correction to continuously improve the accuracy of early warning.

[0086] On the other hand, the present invention provides a closed-loop control and early warning system for molten iron storage in a blast furnace hearth, including:

[0087] A molten iron inventory data calculation module, which is used to collect air volume data, air pressure data, pig iron speed data, and tapping speed data for a target blast furnace within a preset time period, and calculate the molten iron inventory data in the hearth during this time period;

[0088] A molten iron inventory model construction module, which is used to construct a molten iron inventory model based on the pig iron speed, tapping speed, and molten iron inventory in the hearth; divide the molten iron storage process in the blast furnace hearth into four stages according to the molten iron inventory model:

[0089] Stage 1: The slow-flow stage from t1 to t2 after opening the taphole, Stage 2: The fast-flow stage from t2 to t3 after opening the taphole, Stage 3: The buffer stage from t3 to t4 for plugging the taphole,

[0090] Stage 4: The iron stop stage from t4 to t5; where 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 plugging time, t4 is the time when there is no iron flow after the taphole is completely plugged, and t5 is the taphole opening time for the next furnace;

[0091] Obtain the corresponding relationship between the tapping volume and tapping time according to Stage 2 and Stage 3, and perform data statistical analysis based on the tapping volume in Stage 1 to obtain the average total tapping volume Q 缓流-out ;

[0092] A monitoring and early warning module for molten iron inventory and air pressure, which obtains the corresponding relationship between the molten iron storage volume, air volume, and air pressure in the blast furnace hearth based on the historical data of molten iron generation and molten iron discharge, and obtains the molten iron inventory early warning value and air pressure early warning value by monitoring the molten iron inventory, air pressure trend, and blast furnace air reduction operation, so as to realize the monitoring and early warning of the molten iron inventory and air pressure in the blast furnace;

[0093] A front-of-furnace taphole plugging early warning and front-of-furnace taphole opening early warning module, which is used to calculate the front-of-furnace taphole plugging time in Stage 2 and the front-of-furnace taphole opening time in Stage 4 according to the molten iron inventory model in the hearth, so as to realize the front-of-furnace taphole plugging early warning and front-of-furnace taphole opening early warning.

[0094] Although the present invention has been described above with reference to preferred embodiments, it is not intended to limit the present invention. Those of ordinary skill in the art to which the present invention pertains can make various modifications and refinements 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 claims defined therein.

Claims

1. A closed-loop control and warning method for molten iron storage in a blast furnace hearth, characterized in that It includes the following steps: S1. For the target blast furnace, collect the blast volume data, blast pressure data, hot metal production rate data, and tapping rate data within a preset time period, and calculate the hot metal inventory data in the hearth during this time period. S2. Construct a hot metal inventory model in the hearth based on the hot metal production rate, tapping rate, and hot metal inventory in the hearth; divide the storage process of hot metal in the blast furnace hearth into four stages according to the hot metal inventory model: Stage 1: The opening slow flow stage from t1 to t2, Stage 2: The opening fast flow stage from t2 to t3, Stage 3: The taphole plugging buffer stage from t3 to t4, Stage 4: The iron stoppage stage from t4 to t5; wherein, t1 is the time to open the taphole, t2 is the time when the hot metal production rate is equal to the tapping rate after the taphole is opened, t3 is the time to plug the taphole, t4 is the time when there is no iron flow after the taphole is completely plugged, and t5 is the time to open the taphole for the next furnace. According to the corresponding relationship between the tapping volume and the tapping time obtained in the second and third stages, statistical analysis of the data is carried out based on the tapping volume in the first stage, and the average total tapping volume Q is obtained 缓流-out ; S3. Based on the historical data of hot metal generation and hot metal discharge, obtain the corresponding relationship between the hot metal inventory in the blast furnace hearth and the blast volume and blast pressure. By monitoring the hot metal inventory, blast pressure trend, and the blast volume reduction action of the blast furnace, obtain the hot metal inventory warning value and blast pressure warning value, and realize the monitoring and warning of the hot metal inventory and blast pressure in the blast furnace. S4. According to the hot metal inventory model in the hearth, calculate the taphole plugging time in front of the furnace in Stage 2 and calculate the taphole opening time in front of the furnace in Stage 4, and realize the warning of taphole plugging in front of the furnace and the warning of taphole opening.

2. The closed-loop control and early warning method for molten iron storage in a blast furnace hearth according to claim 1, characterized in that, In step S1, the first calculation method of the hot metal production rate is as follows: Obtain the corresponding relationship between the number of batches of materials and time by the actions of the material flow valve and the sounding rod, obtain the material rate, and calculate the weight of the hot metal generated by each batch of materials, that is, the batch hot metal, based on the element conservation of the burden and the hot metal. The product of the batch hot metal and the material rate is the hot metal production rate.

3. A closed-loop control and early warning method for molten iron storage in a blast furnace hearth according to claim 1, characterized in that In step S1, the second calculation method of the hot metal production rate is as follows: Obtain the consumption rate of the burden in the blast furnace by the methods of laser burden surface scanning and radar burden surface scanning, and calculate the hot metal production rate by combining the method of element conservation of the hot metal.

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

5. The closed-loop control and warning method for molten iron storage in a blast furnace hearth according to claim 1, wherein In step S2, the hot metal inventory model in the hearth is as follows: ， Among them, is the molten iron inventory in the hearth, is the pig iron speed, is the tapping speed.

6. The closed-loop control and early warning method for molten iron storage in a blast furnace hearth according to claim 5, characterized in that, In step S2, the corresponding relationship between the tapping amount and the tapping time is as follows: f(x) = 5.23 * x + 50.19; wherein, x represents the tapping time, and f(x) represents the tapping amount.

7. A closed-loop control and early warning method for molten iron storage in a blast furnace hearth according to claim 6, characterized in that The calculation formula for the taphole plugging time in front of the furnace in step S4 is as follows: ， Among them, S1 is the time interval from the current moment to blast furnace t2, is the total amount of molten iron tapped in front of the furnace during the S1 time interval, and S2 is the time interval from the iron notch blocking, is the molten iron inventory in the hearth; The tapping time a2 in front of the furnace is calculated as follows: , where a2 is the time interval from the tapping hole opening, and Q 预警 is the molten iron inventory warning value analyzed from historical data in step S3, and Q 缓流-out is the total average tapping volume in the first stage obtained from historical data analysis in step S2.

8. A closed-loop control and early warning method for molten iron storage in a blast furnace hearth according to claim 7, characterized in that, It further includes: Step S2 further includes: obtaining the correspondence between the tapping volume and the tapping time by using the second stage and the third stage, and the total average tapping volume Q in the first stage 缓流-out Modify the hearth molten iron inventory model.

9. A closed-loop control and early warning system for molten iron storage in a blast furnace hearth, characterized in that It includes: A hot metal inventory data calculation module, which is used for collecting the blast volume data, blast pressure data, hot metal production rate data, and tapping rate data for the target blast furnace within a preset time period, and calculating the hot metal inventory data in the hearth during this time period; A hot metal inventory model construction module in the hearth, which is used for constructing a hot metal inventory model in the hearth based on the hot metal production rate, tapping rate, and hot metal inventory in the hearth; divide the storage process of hot metal in the blast furnace hearth into four stages according to the hot metal inventory model: Stage 1: The opening slow flow stage from t1 to t2, Stage 2: The opening fast flow stage from t2 to t3, Stage 3: The taphole plugging buffer stage from t3 to t4, Stage 4: The stage of stopping iron flow from t4 to t5; where t1 is the time of opening the taphole, t2 is the time when the pig iron production rate is equal to the tapping rate after the taphole is opened, t3 is the time of stopping the taphole, t4 is the time when the taphole is completely blocked and there is no iron flow, and t5 is the time of opening the taphole for the next furnace; According to the corresponding relationship between the tapping volume and the tapping time obtained in Phase II and Phase III, statistical analysis of the data is carried out based on the tapping volume in Phase I to obtain the average total tapping volume Q 缓流-out ; The monitoring and early warning module for molten iron inventory and blast pressure obtains the corresponding relationship between the molten iron inventory in the blast furnace hearth and the air volume and blast pressure based on the historical data of molten iron generation and discharge. By monitoring the molten iron inventory, blast pressure trend, and the blast reduction operation of the blast furnace, the early warning values of molten iron inventory and blast pressure are obtained, realizing the monitoring and early warning of molten iron inventory and blast pressure in the blast furnace; The taphole stopping early warning and taphole opening early warning module in front of the furnace is used to calculate the taphole stopping time in front of the furnace in Stage 2 and the taphole opening time in front of the furnace in Stage 4 according to the molten iron inventory model in the hearth, realizing the taphole stopping early warning and taphole opening early warning in front of the furnace.

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