Characterisation of a smelting process

Abstract

The present invention relates to a method (100) and a system (10) for characterising a smelting process in a blast furnace (3), to a smelting plant (1) and to a method (200; 300) for machine learning of models (16; 24) which can be used in such a method (100) and system (10). Parameter values (A, B, C, D, E) of a predetermined number of different process parameters are determined (S1) for the smelting process currently taking place in the blast furnace (3). Preferably, at least one of the process parameters represents a gas distribution of the blast furnace (3). A machine-learned model (16) assigns (S2) a blast furnace operating state (30), defined by the parameter values (A, B, C, D, E), to an operating category (X, Y, Z) on the basis of the determined parameter values (A, B, C, D, E).

Description

[0001] Description

[0002] Characterization of a smelting process

[0003] field of technology

[0004] The present invention relates to a method and a system for characterizing a smelting process in a blast furnace, a smelting plant and methods for machine learning models that can be used in such a method and system.

[0005] State of the art

[0006] Processes in smelting plants, especially metallurgical processes in blast furnaces, are typically closely monitored. A variety of different sensors can be used for automation and quality assurance. These sensors can be used to record a wide range of different process parameters, which in principle allow statements and / or predictions to be made, for example, regarding reaction processes and rates.

[0007] However, evaluating these parameter values ​​is very complex and time-consuming, as it is generally not sufficient to simply examine individual process parameters to identify sources of error, for example. Rather, a combination of numerous process parameters must usually be considered. Therefore, undesirable process behaviors are often only detected late. Furthermore, it is often not possible, or only with considerable effort and / or experience, to determine the cause of the undesirable process behavior and initiate appropriate countermeasures based solely on the multitude of parameter values.

[0008] JP H07 26127 B2 discloses a control system which automatically controls the temperature in a blast furnace and has a deduction means which determines a blast furnace temperature level based on processed data and a knowledge database using artificial intelligence.

[0009] CN 102 952 912 A concerns the control of a blast furnace based on real-time updating of a knowledge database. Operating data from a blast furnace operation over a period of three to five months is classified using pattern recognition. The classified operating data can then be interpreted with regard to the respective blast furnace process. The knowledge database is then created based on characteristic parameters.

[0010] US 2021 / 0365784 A1 discloses a method for deriving fault diagnosis rules in a blast furnace using a neural network. The network is trained using historical fault data from a blast furnace. The fault diagnosis rules can then be extracted from a further level of the network using a decision tree.

[0011] WO 2022 / 069498 A1 concerns the training of a reinforcement learning-based model so that the model can issue control commands for a blast furnace. In addition to operating data from multiple blast furnaces, artificial operating data generated by a transient model for a predetermined temperature control of a generic blast furnace are also incorporated into the reinforcement learning.

[0012] Summary of the invention

[0013] Against this background, it is an object of the present invention to further improve the characterization of smelting processes in a blast furnace, in particular to simplify and accelerate it.

[0014] This object is achieved by a method and a system for characterizing a smelting process and a smelting plant according to the independent claims.

[0015] A further task is to provide methods by which models that can be used to improve the characterization of a smelting process can be machine-learned.

[0016] This object is achieved by methods for machine learning models that can be used in a method and system described here, according to the independent claims.

[0017] Preferred embodiments are subject of the dependent claims and the following description.

[0018] In a method for characterizing a smelting process in a blast furnace according to a first aspect of the invention, parameter values ​​of a predetermined number of different process parameters are determined for a smelting process currently taking place in a blast furnace. At least one of the process parameters represents a gas flow through the blast furnace. A machine-learned model then assigns a blast furnace operating state defined by the parameter values ​​to an operating category based on the determined parameter values.

[0019] A machine-learned model within the meaning of the invention is preferably a statistical model generated by one or more algorithms based on training data. The machine-learned model can therefore also be referred to as a trained model. The machine-learned model is expediently the result of machine learning. Such a machine-learned model can also be commonly referred to as artificial intelligence, which has recognized patterns and regularities in the training data and can thus also assess or evaluate unknown data according to these patterns and regularities. The machine-learned model can be based, for example, on a neural network or a random forest.

[0020] One aspect of the invention is based on the approach of assessing the operating state of a blast furnace or the smelting process taking place therein using artificial intelligence. This assessment is expediently based on a limited, for example single-digit, number of process parameters. Based on current parameter values ​​of these process parameters, also referred to as process variables, the artificial intelligence can assign the current blast furnace operating state to one of several operating categories. For example, the blast furnace operating state can be assigned to the categories "good," "neutral," or "poor." In principle, however, other categories are also conceivable. This makes it possible, in particular, to detect promptly when the smelting process deteriorates or the blast furnace operating state changes to a worse state.As a result, this deterioration can be responded to promptly, saving resources, especially energy. For example, improved quality feedstocks can be used, or the loading scheme, such as the spatial distribution of feedstocks, can be changed. Furthermore, many process parameters no longer need to be manually monitored and evaluated by experienced operators, which can further reduce effort and costs.

[0021] The artificial intelligence is expediently represented by an appropriately trained model, also referred to as a machine-learned model. The machine-learned model is preferably trained to categorize the blast furnace operating state based on current parameter values ​​of a predetermined number of (a few) process parameters. The blast furnace operating state can thus be assessed effectively, if necessary even without in-depth prior knowledge on the part of the operating personnel, in particular automatically and / or continuously.

[0022] The machine-learned model outputs a measure of the quality of the smelting process to assign the blast furnace operating condition to the operating category. The parameter values ​​characterizing the blast furnace operating condition are thus effectively and automatically summarized by the machine-learned model into an easy-to-interpret key figure that is meaningful even for inexperienced operators.

[0023] It has been shown that the categorization of the blast furnace operating condition using the machine-learned model can be particularly reliable if, among other things, a key figure for the blast furnace's gas flow is considered as an input variable. Inhomogeneous gas flow can indicate impending blockage, channel formation, or unstable burden movement and can therefore be associated with poor blast furnace operating condition, which is accompanied by increased energy consumption. Consequently, gas flow can represent a sensitive and universal process parameter for assessing the blast furnace's operating condition.

[0024] Such a parameter value or key figure for gas flow is given by a pressure curve in the blast furnace. Gas flow is represented by the ratio of a pressure drop in a lower region to a pressure drop in the upper region of the blast furnace, particularly the shaft. The ratio of the pressure drops is typically in the range of 2-16. If the quotient of the pressure drop in the lower region and the pressure drop in the upper region is high, e.g., in the range of 8-16, this can indicate stable gas flow in the burden column and good blast furnace operating condition. In contrast, a low quotient, e.g., in the range of 2-8, can indicate unstable gas flow in the burden column and poor blast furnace operating condition. The value ranges for good or poor gas flow can also depend on the parameter values ​​of the other process parameters.

[0025] Preferred embodiments of the invention and their further developments are described below. These embodiments can be combined with each other and with the aspects of the invention described below, unless expressly excluded.

[0026] It has been shown that a reliable assessment of the blast furnace operating condition or the smelting process does not necessarily require the consideration of a large number of process parameters. Rather, a reliable and rapid categorization of the condition can be achieved even if only parameter values ​​of ten or fewer, preferably five or fewer, or even just four, process parameters are determined and used as the basis for assigning the blast furnace operating condition to an operating category. This can have advantages not only with regard to the required infrastructure or hardware (e.g., reduced number of sensors on the blast furnace to determine the parameter values), but also with regard to machine learning of the model. In particular, it can significantly reduce the size of a training dataset and accelerate model training.

[0027] In addition to the previously mentioned parameter or characteristic value that represents the gas flow through the blast furnace (e.g., a ratio of differential pressures across different blast furnace areas), preferably i) a parameter value for a cooling capacity at the blast furnace, ii) a parameter value that represents carbon monoxide utilization, and / or iii) a parameter value for a reducing agent consumption are determined and used as the basis for assigning the blast furnace operating condition to an operating category. Numerous tests have shown that these process parameters are sufficiently independent of one another and can thus characterize the blast furnace operating condition or the smelting process sufficiently broadly. In this respect, a reliable categorization of the blast furnace operating condition is possible with these process parameters or parameter values.

[0028] The specific cooling capacity of a blast furnace, also referred to as shaft cooling capacity, i.e., the amount of heat removed from the blast furnace shaft per unit of time, is primarily determined by the temperature and volume flow of a cooling medium through a blast furnace cooling system (e.g., 8,000–30,000 kW). A high cooling capacity can indicate a suboptimal smelting process and thus a poor blast furnace operating condition.

[0029] Carbon monoxide utilization conveniently corresponds to the rate at which iron oxide reacts with carbon monoxide formed during the smelting process, ultimately reducing the iron ore used as feedstock (e.g., 44-52%). A conclusion about carbon monoxide utilization can be drawn, for example, from the carbon monoxide content in the blast furnace gas. A high carbon monoxide content can indicate poor blast furnace operating conditions. A low carbon monoxide content, on the other hand, can indicate good blast furnace operating conditions, especially in combination with corresponding parameter values ​​of other process parameters.

[0030] Reducing agent consumption (the sum of coke and substitute reducing agent) can be understood as an indicator of the efficiency of the reduction of iron ore during the smelting process (e.g., 460-510 kg per t of pig iron). Therefore, high reducing agent consumption indicates poor (because inefficient) blast furnace operating conditions.

[0031] If necessary, other process parameters can also be considered additionally or alternatively, e.g., the standard deviation of the depth (i.e., the height of the burden column in the blast furnace). This can, in some cases, at least slightly further increase the robustness of the categorization by the machine-learned model.

[0032] In principle, it is possible to estimate the development of the blast furnace operating state or the smelting process based on the predetermined number of process parameters or the corresponding parameter values, in particular a time profile of these parameter values. For this purpose, the current parameter value of at least one of the process parameters is preferably estimated using at least one further machine-learned model. This estimation is expediently carried out on the basis of the current parameter values ​​of the remaining process parameters. For example, a parameter value that reflects the current gas flow through the blast furnace can be estimated based on current parameter values ​​for the cooling capacity, the pressure drop, the carbon monoxide utilization, and / or the reducing agent consumption.Based on an error output by at least one additional machine-learned model for this estimation, it can then be checked whether there is a disturbance in the blast furnace operating state defined by the current parameter values. The error is expediently considered over a predetermined time period. For example, it can be checked whether the error reaches or exceeds a specified threshold within this time period. If this is the case, this may indicate a disturbance in the smelting process, and the operating personnel are informed accordingly.

[0033] In this context, a predetermined time period is preferably a maximum of 4 to 6 hours, particularly preferably 2 to 4 hours, and in particular a minimum of 30 minutes. Depending on the length of the predetermined time period, different types of disturbances can be identified.

[0034] If the error output by the further machine-learned model or a parameter derived from the error only reaches or exceeds the threshold value for a short time within the predetermined time range, i.e., within a short period of time, for example, a few minutes, up to a maximum of 30 minutes, the disturbance may be a so-called spontaneous state change (point anomaly). The threshold value can therefore also be referred to as a "spike limit." Such spontaneous state changes are detected, for example, when a sensor is defective and accordingly delivers incorrect parameter values. In this sense, a spontaneous state change can be a virtual state change, and the associated disturbance in the blast furnace operating state can be a virtual disturbance.On the other hand, such a spontaneous change of state can also be caused by a temporary disturbance in the smelting process, such as a collapse of the burden column in the blast furnace shaft. The type of spontaneous change of state can be determined, if necessary, through a more detailed analysis of the process parameters, in particular the temporal development of the other process parameters and / or the other errors output by the at least one machine-learned model.

[0035] However, if the error output by the additional machine-learned model or the characteristic value derived therefrom reaches or exceeds the threshold value within the predetermined time range over a longer period of time, i.e. within a long period of time of, for example, more than 1 hour, the fault may be a state change (i.e. a change to a different operating state). Such state changes may occur, for example, due to a change in the operation of the blast furnace or other phenomena, such as buildup or hanging of the burden column. Here, too, further analysis of the process parameters, in particular the temporal development of the other process parameters and / or the other errors output by the at least one additional machine-learned model, may provide additional information about the state change, in particular its cause.

[0036] It is therefore particularly preferred not only to estimate a current parameter value for one process parameter and then use the error determined in the process (or a characteristic value derived therefrom) as the basis for checking whether a fault exists. Rather, the current parameter values ​​for each process parameter are preferably estimated using a corresponding number of further machine-learned models on the basis of current parameter values ​​of the other process parameters. On the basis of the errors output by the further machine-learned models for these estimates, an overall error is expediently determined, which then forms the basis for checking whether there is a fault in the blast furnace operating state defined by the parameter values ​​of the process parameters. This overall error or a characteristic value derived therefrom, e.g.A smoothed total error is also checked to determine whether it reaches or exceeds a specified threshold, or, if applicable, how long this threshold is reached or exceeded. The evaluation of the total error enables a particularly reliable assessment of the blast furnace operating condition and its development, in particular whether a spontaneous change in condition is occurring or at least imminent.

[0037] To determine the cause of the disruption to the smelting process or the blast furnace operating condition, the individual errors determined for the estimates and / or the determined total error are preferably considered. This should also include the consideration of derived parameters, such as a smoothed total error.

[0038] For example, it can be checked for which process parameters the detected errors are increasing, for example whether they reach or exceed the corresponding threshold values. Preferably, the temporal development, i.e. the temporal progression, of the parameter values ​​and / or the corresponding errors is also evaluated. If, for example, a poor or at least only neutral blast furnace operating state is suddenly determined using the machine-learned model, those process parameters whose corresponding error reaches or exceeds the corresponding threshold value can provide an indication of the cause of the change in state or the now poor or only neutral state. In particular, on this basis, for example using explainable Kl (explainable AI algorithms), the operating personnel can receive indications as to which of the process parameters is “conspicuous” and thus primarily responsible for a “poor” operating state.If necessary, it is also possible to estimate a further development of the blast furnace operating state based on the temporal progression of the parameter values ​​of at least one of the process parameters and a parallel temporal progression of the assigned operating categories. For this purpose, for example, a trajectory of the blast furnace operating state can be determined and visualized. This allows the operating personnel to take countermeasures at an early stage and thus, if necessary, avert a transition to a poor operating state. It is also conceivable to have the temporal progression of the parameter values ​​and / or the parallel assigned operating category, in particular the trajectory, analyzed by an algorithm and to have an alarm issued automatically or at least semi-automatically if the algorithm detects that the smelting process is deteriorating.

[0039] The system for characterizing a smelting process in a blast furnace, according to a second aspect of the invention, comprises: i) a sensor device for a blast furnace, with which parameter values ​​of a predetermined number of different process parameters can be determined during a smelting process taking place in the blast furnace, wherein at least one of the process parameters represents a gas flow through the blast furnace; and ii) a categorization device which has a first machine-learned model and is configured to assign a blast furnace operating state defined by the parameter values ​​to an operating category on the basis of the determined parameter values, in particular by means of the machine-learned model.

[0040] With such a system, the blast furnace operating status can be assessed effectively, possibly even without the operating personnel requiring in-depth prior knowledge. This eliminates the need to manually monitor and evaluate numerous process parameters based on experience, reducing effort and costs. Furthermore, it can also be detected promptly if the smelting process is deteriorating. This allows for prompt response to this deterioration, saving resources, especially energy, used to operate the blast furnace.

[0041] The sensor device expediently has different sensor types in order to be able to record the parameter values ​​of the predetermined number of process parameters. Expediently, the number of sensor types corresponds to the predetermined number of process parameters. One or more sensors can be provided per sensor type in order to be able to record the parameter values ​​of the corresponding process parameter precisely and comprehensively, for example with spatial resolution. Preferably, at least one sensor is provided for detecting the gas flow through the blast furnace, e.g., at least one sensor for detecting a pressure drop in the blast furnace, at least one sensor for detecting the cooling capacity of the blast furnace, at least one sensor for detecting carbon monoxide utilization, and / or at least one sensor for detecting reducing agent consumption. The categorization device can be implemented in software and, if appropriate, additionally, at least partially, in hardware.The categorization device can in particular have a processing unit, preferably connected to a memory and / or bus system in terms of data or signals. For example, the categorization device can have a microprocessor unit (CPU) or a module thereof and / or one or more programs or program modules. In particular, the machine-learned model can form a program or software module of the categorization device. The categorization device can be designed to process instructions implemented as a program stored in a memory system or as a machine-learned model, to detect input signals from a data bus, and / or to output signals to a data bus. A memory system can have one or more, in particular different, storage media, in particular optical, magnetic, solid-state, and / or other non-volatile media. The program orThe machine-learned model may be such that it embodies or is capable of carrying out the process described here or at least parts thereof, so that a smelting process can be characterized with it.

[0042] The plant for smelting a feedstock, in particular a metal ore, according to a third aspect of the invention comprises a blast furnace and a system for characterizing a smelting process according to the second aspect of the invention. The sensor device of the system is arranged in the region of the blast furnace. For example, the sensor device, in particular at least one sensor of the sensor device, can be arranged in and / or on the blast furnace and configured to determine characteristic process parameters for subprocesses of the smelting process taking place in and / or on the blast furnace—such as the reduction of components of the burden, the gasification of the burden, the removal of thermal energy, a resulting pressure drop in the blast furnace shaft, and / or the like. In this sense, a sensor device or a sensor can also be understood as an interface via which corresponding parameter values ​​can be accessed.For example, parameter values ​​such as the current cooling capacity of the blast furnace and / or the current reducing agent consumption can be provided by a plant or blast furnace control system, e.g., via an interface. This allows process-critical process parameters in particular to be determined directly and reliably.

[0043] According to a fourth aspect of the invention, in the method for machine learning a model, which can be used in a method according to the first aspect of the invention, i) parameter values ​​of a predetermined number of different process parameters are provided, which were determined during a smelting process taking place in a blast furnace over a predetermined period of time, wherein at least one of the process parameters represents a gas flow through the blast furnace, ii) blast furnace operating states defined by a set of parameter values ​​of the process parameters are assigned to an operating category at different times within the predetermined period of time, and iii) a model is machine learned by means of an algorithm on the basis of the parameter values ​​defining the blast furnace operating states and the respectively assigned operating categories.

[0044] Using such a machine-learned model, a current blast furnace operating state can be quickly and reliably assigned to an operating category. This does not require a large, e.g., double-digit, number of different process parameters. Rather, a small number of process parameters, such as five or even just four, is sufficient to perform a robust categorization of a current blast furnace operating state.

[0045] A predetermined period of time within the meaning of the invention is preferably a period of at least two years, in particular essentially three years. Within this period, a blast furnace typically undergoes a sufficient number of different operating states to allow robust training of the model.

[0046] To enable robust operation with reproducible results from the machine-learned model, the most relevant process parameters and / or time ranges for blast furnace operating conditions are selected based on process engineering experience, for example, by experienced operators. The parameter values ​​of these selected process parameters can be taken, for example, from a database containing historical blast furnace operating data.

[0047] Tests have shown that the most relevant process parameters are the gassing of the blast furnace, the cooling capacity of the blast furnace, the pressure drop in the blast furnace, the carbon monoxide utilization in the blast furnace and / or the reducing agent consumption.

[0048] For practical purposes, experienced operating personnel manually assign each set of process parameter values, or the resulting blast furnace operating state, to a process category. For example, the respective blast furnace operating state can be assigned to one of three states: "good," "neutral," or "poor" for a variety of time points. The resulting data set can then be analyzed by artificial intelligence, i.e., the model can be machine-learned using this data set.

[0049] According to a fifth aspect of the invention, in the method for machine learning a further model, which can be used in a method according to the first aspect of the invention, i) parameter values ​​of a predetermined number of different process parameters are provided, which were determined during a smelting process taking place in a blast furnace over a predetermined period of time, wherein at least one of the process parameters represents a gas flow through the blast furnace, and ii) by means of an algorithm on the basis of parameter values ​​of the process parameters from a plurality of predetermined process sections, a further model is machine-learned, with which a current parameter value can be estimated for at least one process parameter on the basis of the current parameter values ​​of the other process parameters.

[0050] A predetermined process section in the sense of the invention is preferably a predetermined time range or is defined by the predetermined time range, i.e. a predetermined period of time.

[0051] Using such an additional machine-learned model, the current parameter value of an additional process parameter can be reliably estimated based on the current parameter values ​​of various process parameters. This does not require the use of a large number of different process parameters. Rather, current parameter values ​​of a small number of process parameters, for example, four or even just three process parameters, are sufficient to enable a robust estimation of the parameter value of the additional process parameter.

[0052] Here, too, process parameters and time ranges in which the parameter values ​​of the selected process parameters are taken into account are expediently selected on the basis of process engineering experience, for example by experienced operating personnel. The specific blast furnace operating states corresponding to this selection can serve as training data for one or more further models. By selecting in particular those time ranges - i.e. corresponding process stages of the smelting process - in which different blast furnace operating states occur, the model or models can be trained in particular to recognize deviations from a current blast furnace operating state and / or changes to another operating state, i.e. a different operating category. The error output by the trained model can also be used as an indicator of such deviations or changes in operating state.

[0053] The above-described properties, features, and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more readily understood in connection with the following description of an embodiment, which is explained in more detail in conjunction with the drawings.

[0054] FIG 1 shows an example of a plant for smelting a feedstock;

[0055] FIG 2 shows an example of a method for characterizing a smelting process; FIG 3 shows an example of a trajectory of a blast furnace state;

[0056] FIG 4 shows an example of a time course of a total error determined when estimating current parameter values;

[0057] FIG 5 shows an example of a method for machine learning a model; and

[0058] FIG 6 shows an example of a method for machine learning another model.

[0059] Where appropriate, the same reference numerals are used in the figures for the same or corresponding elements of the invention.

[0060] Description of the embodiments

[0061] FIG 1 shows an example of a plant 1 for smelting a feedstock 2, in particular a metal ore. Plant 1 comprises a blast furnace 3, which can be charged with feedstock 2, a reducing agent, such as coke, and optionally additives. In a shaft 4 of blast furnace 3, feedstock 2, the reducing agent, and optionally additives form a burden, also referred to as bed 5.

[0062] The plant 1 also has a system 10 for characterizing a smelting process taking place in the blast furnace 3, which comprises a sensor device 12 and a categorization device 14 with a machine-learned model 16. The sensor device 12 is arranged in the region of the blast furnace 3, in particular in and / or on the blast furnace 3, and comprises a plurality of sensors 18 for determining parameter values ​​of a predetermined number of process parameters. The sensors 18 can represent different sensor types, with which, for example, i) gassing of the bed 5, ii) a pressure drop in the shaft 4, iii) carbon monoxide utilization during the reduction of the feedstock 2 in the bed 5, iv) the amount of heat transported from the shaft 4 per unit time, and / or v) reducing agent consumption can be recorded.Alternatively or additionally, the sensor device 12 can also have an interface to be understood as a sensor 18 for this purpose, via which parameter values ​​for such process parameters can be retrieved, for example, from a system control 20.

[0063] The categorization device 14 is configured to assign a blast furnace operating state defined by the parameter values ​​to one of several operating categories based on the determined parameter values. For this purpose, the determined parameter values ​​can, for example, be fed to the machine-learned model 16 as input values. In other words, the machine-learned model 16 can evaluate the determined parameter values ​​to determine the blast furnace operating state and assign it to an operating category. The result of this assignment, for example, a code characterizing the operating category, can expediently be output via an output interface 22, such as a screen, a data bus, a printer, and / or the like.

[0064] FIG 2 shows an example of a method 100 for characterizing a smelting process. In a method step S1, parameter values ​​A, B, C, D, E of a predetermined number of different process parameters are determined for a smelting process currently taking place in a blast furnace. Five process parameters are considered here purely as an example. The parameter values ​​A to E of the five process parameters are expediently characteristic of the current blast furnace operating state. In addition to gassing of the blast furnace, they can, for example, represent a cooling capacity at the blast furnace, a pressure drop in the blast furnace, a carbon monoxide utilization in the blast furnace, and a reducing agent consumption. The parameter values ​​A to E can, for example, be detected and / or retrieved by means of a sensor device.

[0065] In a further process step S2, a machine-learned model 16 assigns a blast furnace operating state defined by the parameter values ​​A to E to an operating category X, Y, Z based on the determined parameter values ​​A to E. In particular, the blast furnace operating state characterized by the parameter values ​​A to E is compressed into an easily interpretable key figure. The machine-learned model 16 can thus represent the several years of experience of a plurality of operators or the corresponding expert knowledge.

[0066] One of the operating categories, operating category X, can, for example, represent "good," i.e., desired, operating conditions of the blast furnace, in which the smelting process runs efficiently and essentially without disruption. Blast furnace operating conditions of operating category X require a relatively low use of resources such as energy, reducing agents, possibly additives, and / or the like to operate the blast furnace. Operating category X is indicated in FIG. 2 by the absence of hatching.

[0067] Another operating category, operating category Y, can represent “neutral”, i.e. tolerable, but not optimal operating conditions of the blast furnace. In the blast furnace operating conditions of operating category Y, the smelting process can be comparatively less efficient and, under certain circumstances, with minor disruptions. This can result in temporarily increased resource consumption and / or a failure or defect of individual sensors in the sensor device for determining the parameter values ​​A to E. Operating category Y is identified in FIG 2 by the vertical hatching. Another operating category, operating category Z, can represent “poor”, i.e. undesirable, operating conditions of the blast furnace in which the smelting process is inefficient and / or is permanently disrupted.Blast furnace operating conditions in operating category Z require a relatively high level of resource input for blast furnace operation and / or involve problematic or even critical process developments and consequences, such as deposit formation on the shaft walls or burden sagging. Operating category Z is indicated by horizontal hatching in FIG. 2.

[0068] In a further preferred method step S3, the operating category X to Z assigned to the current blast furnace operating state is output, for example, via an interface such as a display or at least a data bus. The output could be conceivable as a kind of "traffic light" indicator, allowing operating personnel to reliably identify the blast furnace operating state without the complex and time-consuming manual evaluation of a multitude of operating parameters or without extensive process engineering experience.

[0069] If necessary, in process step S3, not only the operating category X to Z but also a condition forecast or at least a trend of how the blast furnace operating condition is developing can be output. This condition forecast or trend can be visualized in one of several ways, for example, as a 2D plot, in particular as a projection of selected process parameters into a two-dimensional representation, or as a curve over a predetermined period of time, such as a curve over the last week. A possible visual representation is shown in FIG 3.

[0070] FIG. 3 shows an example of a trajectory 110 of a blast furnace operating state 30. The blast furnace operating state 30 can generally be defined by the parameter values ​​of a predetermined number of process parameters. To illustrate the trajectory 110 in FIG. 3, operating categories assigned to the blast furnace operating state 30 at different times, which are indicated by different hatching, are plotted against two of these process parameters with the parameter values ​​A, B. Consecutive points in time are connected by lines. For reasons of clarity, the blast furnace operating state 30 is provided with a reference symbol only at the start time.

[0071] FIG 3 shows that the blast furnace in which the smelting process takes place is initially in a "good" condition. This blast furnace operating condition 30 is indicated in FIG 3 by the absence of hatching.

[0072] As time progresses, the process parameter plotted on the abscissa increases, i.e., the corresponding parameter value A increases. The blast furnace transitions to a "neutral" state, which is indicated by vertical hatching in FIG. 3. Finally, both process parameters shrink, i.e., the corresponding parameter values ​​A and B decrease, and the blast furnace transitions to a "poor" state. This blast furnace operating state 30 is indicated by horizontal hatching in FIG. 3. Towards the end of the trajectory 110, the parameter value B increases again, and the "good" operating state is restored.

[0073] Such a trajectory 110 can be determined and, as shown by way of example in FIG. 3, visualized by assigning the blast furnace operating state 30 to one of the operating categories by means of a corresponding machine-learned model using the method described in connection with FIG. 2 on the basis of the parameter values ​​determined at several successive points in time.

[0074] Advantageously, not just two process parameters are considered, but several, in addition to the gas flow through the blast furnace, such as the ratio of differential pressures across different blast furnace areas, e.g., the blast furnace cooling capacity, carbon monoxide utilization, and / or reducing agent consumption. In this respect, the trajectory can also be multidimensional, i.e., extend in more than two dimensions. For visualization, such a multidimensional trajectory of the blast furnace condition can be projected onto a plane, particularly onto main components, and thus represented as a two-dimensional plot. This allows a holistic overview of the operating condition to be created.

[0075] In principle, it is also conceivable to additionally display "historical" operating data of the blast furnace, i.e., older pairs and / or projections of parameter values ​​A, B, in such a plot, e.g., in the trajectory 110 shown in FIG. 3. These operating data can, for example, be displayed transparently in the background of the trajectory 110 to enable a comparison with past operating conditions.

[0076] FIG 4 shows an example of a time course 120 of a total error G determined during the estimation of current parameter values, for example by means of further machine-learned models. For this purpose, the total error G is plotted against time t in a process section T, ie within a certain time range.

[0077] Such a total error G can be determined, for example, by determining a parameter value for a predetermined number of process parameters at a time while a smelting process is taking place in a blast furnace. For each of the process parameters, the parameter value can then be additionally estimated using the additional machine-learned model specifically for this process parameter, based on the parameter values ​​of the remaining process parameters. The additional machine-learned model expediently outputs an error, for example as the difference between the estimated parameter value and the actually determined, e.g. measured, parameter value. Using the corresponding additional machine-learned models, this can be done for each process parameter, so that an error is determined for each process parameter.The total error G can then be calculated based on the errors determined for each process parameter, for example, by averaging, weighted averaging, and / or another suitable statistical method. If this is performed for several consecutive points in time, a time course 120 of the total error G is obtained.

[0078] Due to the significant fluctuation of the determined total error G, smoothing may be considered. A suitable smoothing method, such as a regression analysis or a regression analysis, can be applied for this purpose. The result of such a smoothing, the smoothed total error 122, is shown as a dashed line in FIG. 4.

[0079] In principle, the total error G, in particular the time profile 120, can be used to check whether a disturbance S in the blast furnace operating state is present. For example, it can be checked whether the smoothed total error 122 reaches or exceeds a first predetermined threshold value 124, which can also be referred to as the "average limit" and is shown in FIG. 4 as a horizontal, dash-dotted line. In FIG. 4, this is the case in the period marked by the dotted vertical lines. Such a disturbance S, present over a longer period of time, can indicate a change in state, also referred to as "drift," such as that caused, for example, by the formation of deposits on the shaft wall or the hanging of the burden in the shaft.

[0080] Alternatively or additionally, it can also be checked whether the total error G reaches or exceeds a second predefined threshold value 126, which can also be referred to as the "spike limit" and is also shown in FIG. 4 as a horizontal, dash-dotted line. In FIG. 4, this is the case for a short period of time. Such a short disturbance S is also referred to as a spontaneous change of state or point anomaly and can be triggered, for example, by a defect in a measuring instrument or by the loader falling after hanging.

[0081] If necessary, the cause of the fault S can be determined more precisely by also considering the temporal progression 120 of the individual errors determined for each process parameter and / or the temporal progression 120 of the corresponding parameter values, i.e., the temporal development of these errors or values. In particular, just as for the overall error G, it can be checked for each individual error determined for each process parameter whether a first predetermined threshold value 124 and / or a second predetermined threshold value 126 is reached or exceeded and, if necessary, also whether this correlates in time with the fault S identified on the basis of the overall error G. In this way, it can be deduced, if necessary, which of the process parameters are involved in the fault S or even cause it.

[0082] FIG. 5 shows an example of a method 200 for machine learning a model 16, which assigns a blast furnace operating state defined by determined parameter values ​​A, B, C, D, E of a predetermined number of process parameters to an operating category X, Y, Z. The operating categories X to Z are indicated by hatching, as in FIG. 2.

[0083] In a method step V1, the parameter values ​​A to E determined over a predetermined period of time during a smelting process in a blast furnace are provided. Providing these values ​​may include determining them, for example, by sensory detection or retrieval. For example, in method step V1, a database in which the parameter values ​​A to E are stored over a period of several years, for example, up to three years, may be read out.

[0084] In a further process step V2, blast furnace operating states defined by a set of parameter values ​​A to E are assigned to one of the operating categories X to Z at different times within the predetermined period. This assignment can be performed manually, for example, by experienced operators. The assignment is therefore based on expert knowledge. This assignment creates a new data set that can be used as a training data set in a further process step V3.

[0085] In the subsequent process step V3, model 16 is machine-learned using an algorithm based on the parameter values ​​A to E defining the blast furnace operating states and the respective associated operating categories X to Z. In other words, model 16 is trained based on the training data set generated in process step V2, so that it can automatically assign one of the operating categories X to Z to a blast furnace operating state defined by new current parameter values ​​A to E.

[0086] FIG 6 shows an example of a method 300 for machine learning of a further model 24, which estimates a current parameter value A of a process parameter from a predetermined number of process parameters on the basis of current parameter values ​​B, C, D, E of further process parameters.

[0087] In a method step W1, the parameter values ​​A to E of the predetermined number of different process parameters are provided, which were determined over a predetermined period of time during a smelting process taking place in a blast furnace. Providing these values ​​can include determining them, for example, by sensory detection or retrieval. For example, in method step W1, a database in which the parameter values ​​A to E are stored over a period of several years, for example, up to three years, can be read out.

[0088] In a further method step W2, the further model 24 is machine-learned by means of an algorithm on the basis of parameter values ​​A to E of the process parameters from a plurality of predetermined process sections T within the predetermined period of time. For example, the further model 24 can be trained under the proviso that the parameter value A is estimated on the basis of the parameter values ​​B to E. In this case, in particular for each of the predetermined process sections T, the time profile 120 of the parameter value A and the corresponding parameter values ​​B to E can also be taken into account, ie the learning of the estimate of the parameter value A can be used as a basis. These time profiles 120 are shown in FIG 6 for the parameter values ​​A to C during a process section T by plotting the parameter values ​​A to C against time t.

[0089] Although the invention has been illustrated and described in detail by the preferred embodiments, the invention is not limited by the disclosed examples and other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention.

[0090] List of reference symbols

[0091] 1 system

[0092] 2 Input material

[0093] 3 blast furnace

[0094] 4 shafts

[0095] 5 Bulk

[0096] 10 systems

[0097] 12 Sensor device

[0098] 14 Categorization device

[0099] 16 Model

[0100] 18 Sensor

[0101] 20 Plant control

[0102] 22 Output interface

[0103] 24 additional models

[0104] 30 Blast furnace operating condition

[0105] 100 methods for characterizing a smelting process

[0106] S1 Determination of parameter values

[0107] S2 Assigning an operating category

[0108] S3 Output of the assigned operating category

[0109] 200 methods for machine learning a model

[0110] V1 Providing parameter values

[0111] V2 Assigning operating categories

[0112] V3 Learning the model

[0113] 300 methods for machine learning another model

[0114] W1 Providing parameter values

[0115] W2 Learning the further model

[0116] 110 T rajectory

[0117] 120 time course

[0118] 122 smoothed total error

[0119] 124 first threshold

[0120] 126 second threshold

[0121] A, B, C, D, E Parameter value X, Y, Z Operating category

[0122] G Total error t Time

[0123] S disturbance

[0124] T Process section

Claims

Claims 1. Method (100) for characterising a smelting process in a blast furnace (3), wherein - parameter values (A, B, C, D, E) of a predetermined number of different process parameters are determined (S1) for a smelting process currently taking place in a blast furnace (3), wherein at least one of the process parameters represents a gas flow through the blast furnace (3) based on the ratio of a pressure drop in a lower region of the blast furnace (3) to a pressure drop in the upper region of the blast furnace (3), and - a machine-learned model (16) assigns (S2) a blast furnace operating state (30) defined by the parameter values (A, B, C, D, E) to an operating category (X, Y, Z) on the basis of the determined parameter values (A, B, C, D, E) and outputs a measure of the quality of the smelting process, so that the parameter values (A, B, C, D, E) characterizing the blast furnace operating state are summarized by means of the machine-learned model (16) to form an easily interpretable key figure.

2. Method (100) according to claim 1, wherein the parameter values (A, B, C, D, E) of ten or fewer, preferably of five or fewer, in particular four, process parameters are determined and used as the basis for assigning the blast furnace operating state (30) to an operating category (X, Y, Z).

3. Method (100) according to claim 1 or 2, wherein in addition to a parameter value (A, B, C, D, E) which represents a gassing of the blast furnace (3), a parameter value (A, B, C, D, E) for a cooling capacity at the blast furnace (3), a parameter value which represents a pressure drop in the blast furnace (3), a parameter value which represents a carbon monoxide utilization, and / or a parameter value for a reducing agent consumption are determined and used as the basis for assigning the blast furnace operating state (30) to an operating category (X, Y, Z).

4. Method (100) according to one of the preceding claims, wherein - by means of at least one further machine-learned model (24), the current parameter value (A) of at least one of the process parameters is estimated on the basis of current parameter values (B, C, D, E) of the remaining process parameters and - on the basis of an error output by at least one further machine-learned model (24) for this estimation, it is checked whether there is a disturbance (S) in the blast furnace operating state (30) defined by the current parameter values (A, B, C, D, E).

5. Method (100) according to one of the preceding claims, wherein - by means of further machine-learned models (24), the current parameter values (A, B, C, D, E) for each process parameter are estimated on the basis of current parameter values (A, B, C, D, E) of the remaining process parameters, and - on the basis of errors output by the further machine-learned models (24) for these estimates, a total error (G) is determined, which is used as the basis for a check as to whether there is a disturbance (S) in the blast furnace operating state (30) defined by the parameter values (A, B, C, D, E) of the process parameters.

6. The method (100) according to claim 5, wherein a cause for the disturbance (S) of the blast furnace operating state (30) defined by the parameter values (A, B, C, D, E) of the process parameters is determined on the basis of the errors determined for the estimates and / or the total error (G).

7. Method (100) according to one of the preceding claims, wherein a further development of the blast furnace operating state (30) is estimated on the basis of a time profile (120) of the parameter values (A, B, C, D, E) of at least one of the process parameters and a parallel time profile (120) of the assigned operating categories (X, Y, Z).

8. System (10) for characterizing a smelting process in a blast furnace (3), comprising - a sensor device (12) for a blast furnace (3), with which current parameter values (A, B, C, D, E) of a predetermined number of different process parameters can be determined during a smelting process taking place in the blast furnace (3), wherein at least one of the process parameters represents a gassing of the blast furnace (3) based on the ratio of a pressure drop in a lower region of the blast furnace (3) to a pressure drop in the upper region of the blast furnace (3), and - a categorization device (14) which has a machine-learned model (16) and is designed to assign a blast furnace operating state (30) defined by the parameter values (A, B, C, D, E) of the process parameters to an operating category (X, Y, Z) on the basis of the determined parameter values (A, B, C, D, E) and to output a measure of the quality of the smelting process, so that the parameter values (A, B, C, D, E) characterizing the blast furnace operating state are summarized by means of the machine-learned model (16) to form an easily interpretable key figure.

9. Plant (1) for smelting a feedstock (2), in particular a metal ore, with a blast furnace (3) and a system (10) for characterizing a smelting process according to claim 8, wherein the sensor device (12) of the system (10) is arranged in the region of the blast furnace (3).

10. Method (200) for machine learning of a model (16) which is implemented in a Method (100) according to one of claims 1 to 7, wherein - parameter values (A, B, C, D, E) of a predetermined number of different process parameters are provided (V1), which were determined during a smelting process taking place in a blast furnace (3) over a predetermined period of time, wherein at least one of the process parameters represents a gassing of the blast furnace (3) based on the ratio of a pressure drop in a lower region of the blast furnace (3) to a pressure drop in the upper region of the blast furnace (3), - blast furnace operating states (30) defined by a set of parameter values (A, B, C, D, E) of the process parameters are assigned to an operating category (X, Y, Z) at different times within the predetermined period (V2) and - a model (16) is machine-learned by means of an algorithm on the basis of the parameter values (A, B, C, D, E) defining the blast furnace operating states (30) and the respectively assigned operating categories (X, Y, Z).

11. Method (300) for machine learning of a further model (24) which can be used in a method (100) according to one of claims 4 to 6, wherein - parameter values (A, B, C, D, E) of a predetermined number of different process parameters are provided (W1), which were determined during a smelting process taking place in a blast furnace (3) over a predetermined period of time, wherein at least one of the process parameters represents a gas flow through the blast furnace (3) based on the ratio of a pressure drop in a lower region of the blast furnace (3) to a pressure drop in the upper region of the blast furnace (3), and - by means of an algorithm on the basis of parameter values (A, B, C, D, E) of the process parameters from a plurality of predetermined process sections (T), a further model (24) is machine-learned (W2), with which a current parameter value (A) can be estimated for at least one process parameter on the basis of the current parameter values (B, C, D, E) of the remaining process parameters.

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