Method for regulating operation of electric furnace and electric furnace for melting molten material

Abstract

The invention relates to a method for regulating the operation of an electric furnace (10) during a melting process of molten material, comprising the following method steps:-performing a model predictive calculation (S1) of a target curve of at least one operating characteristic (Op) up to a time range (N) on the basis of the results of the melting process to be achieved; and-setting (S2) the at least one operating characteristic (Op) by means of the electrode positioning means (30) and / or the power supply means (50) in such a way that the at least one operating characteristic (Op) lies on the target curve of the at least one operating characteristic (Op) at a predetermined future point in time. The invention also relates to an electric furnace (10) configured to perform a method for adjusting the operation of the electric furnace (10) during a melting process of a molten material.

Description

TECHNICAL FIELD

[0001] The present invention relates to a method for regulating the operation of an electric furnace during a melting process of a melting material and to an electric furnace configured to perform the method for regulating the operation of an electric furnace. BACKGROUND

[0002] Melting materials, in particular metals, are periodically melted and heated in a melting unit during a melting process. These electrically operated melting units, in particular electric furnaces such as electric arc furnaces, electric reduction furnaces and / or submerged arc furnaces, are operated with direct current (DC), alternating current (AC) or multiphase alternating current.

[0003] The melting process of a melting material typically comprises at least one melting cycle. A melting cycle typically comprises different operational steps such as, but not limited to:

[0004] - charging the furnace with melting material, typically scrap and / or direct reduced iron (DRI)

[0005] - generating an electric arc between the melting material and the electrodes of the furnace

[0006] - perforating the melting material to start the melting process

[0007] - forming a molten bath of the melting material

[0008] - refining the melting material to regulate the temperature and material composition of the molten bath

[0009] - de-slagging the melting material present in the electric furnace

[0010] - tapping the melting material present in the electric furnace.

[0011] During the different operational steps of a melting cycle of a melting process, the operational characteristics of the electric furnace will exhibit different values depending on the specific result to be achieved. The operational characteristics of the electric furnace include, but are not limited to, the voltage, the current, the electric frequency and the electrode position. The specific results achieved with a melting process include, but are not limited to, minimizing the time required to complete the melting process, minimizing the wear of the electric furnace and minimizing the electric energy required to complete the melting process.

[0012] Conventional methods for regulating the operation of an electric furnace during a melting process of a melting material follow fixed target profiles of these operational characteristics to set the operational characteristics of the electric furnace depending on the given melting material and the specific result to be achieved. For example in this way, by regulating for example the electrode position and / or the current and / or the voltage, a fixed given target amount of electric energy to be delivered to the melting material in a specific operational step of a melting cycle is achieved.

[0013] However, these known types of methods for regulating the operation of an electric furnace during a melting process of a melting material have the drawback of being associated with a wide variation of the instantaneous power absorption taken from the power grid and occurring, in particular but not exclusively, during the piercing of the melting material. The collapse of the melting material causes short circuits and disturbances in the electric arc. In view of this instantaneous variability of the power absorption of the electric furnace, voltage fluctuations are generated in the power supply grid, causing the so-called flicker phenomenon. This instantaneous variability of the power absorption can be measured by means of the so-called dynamic factor. The dynamic factor is defined as the ratio between the measured actual reactance of the entire electric furnace and the reactance within the electric circuit of the electric furnace. Furthermore, this instantaneous variability of the power absorption of the electric furnace causes non-optimal process conditions, such as increased wear, in particular of the electrodes and the furnace, and increased consumption of electric energy for a given quantity of melting material. SUMMARY

[0014] The present invention is based on this problem and provides a method for regulating the operation of an electric furnace during a melting process of a melting material, which is able to reduce the instantaneous variability of the power absorption of the electric furnace and, therefore, also to minimize the dynamic factor throughout the melting process of the melting material.

[0015] The underlying problem of the present invention is solved by a method for regulating the operation of an electric furnace during a melting process of a melting material according to claim 1. Advantageous embodiments of the method are described in the claims depending on claim 1.

[0016] In more detail, the underlying problem of the present invention is solved by a method for regulating the operation of an electric furnace during a melting process of a melting material, the electric furnace comprising: an electrode positioning device for positioning at least one electrode, preferably a plurality, for example two or three or more electrodes, of the electric furnace; an electric power supply device for supplying electric power to the at least one electrode; and an electronic control device data-coupled to the electrode positioning device and to the electric power supply device for transmitting signals. The method comprises the following method steps:

[0017] - model-predictive calculation of a target curve of the at least one operating property over a time range until a future time point, based on a result to be achieved by the melting process; and

[0018] - setting the at least one operating property by means of the electrode positioning device and / or the electric power supply device in such a way that the at least one operating property is located on the target curve of the at least one operating property at a predetermined future time point.

[0019] The method according to the present application has the advantage that at any given point in time the deviation of at least one operating characteristic from its optimum value is significantly reduced. This leads to a significant reduction of the momentary variability of the power absorption of the electric furnace and thus helps to reduce flicker in the power supply grid and at the same time improves the overall energy efficiency of the electric furnace. For example, for the minimum amount of electrical energy required to heat the melting material to a predetermined temperature, the deviation of the current of at least one electrode from its optimum value is reduced at any given point in time.

[0020] The melting process can comprise one or more melting cycles. A melting cycle can comprise the following operational steps:

[0021] - charging the melting material, typically scrap and / or direct reduced iron (DRI), into the furnace

[0022] - generating an electric arc between the melting material and the electrodes of the furnace

[0023] - perforating the melting material to start the melting process

[0024] - forming a molten bath of the melting material

[0025] - refining the melting material to adjust the temperature and material composition of the molten bath

[0026] - de-slagging the melting material present in the electric furnace

[0027] - tapping the melting material present in the electric furnace.

[0028] A melting cycle can also comprise additional operational steps which can be executed in sequence and / or in parallel to the above operational steps, such as but not limited to:

[0029] - additionally heating the melting material using gas burners and / or oxygen lances

[0030] - adjusting the chemical composition of the melting material by using oxygen lances within the melting material

[0031] - adjusting the chemical composition of the melting material by injecting additives, such as carbon, lime and / or dolomite or any combination of these, into the melting material

[0032] A melting cycle can comprise further operational steps which are specific to a particular melting material and / or a result to be achieved during the melting process. The further operational steps of a melting cycle can comprise injecting additives and / or alloying elements into the melting material. Particular operational steps of a melting cycle can be repeated several times within one melting cycle.

[0033] The electric furnace can be an electric arc furnace, an electric reduction furnace or a submerged arc resistance furnace. The electric furnace can be operated with direct current (DC), alternating current (AC) or multi-phase alternating current.

[0034] The molten material can comprise metallic material, in particular steel material, and / or direct reduced iron material. The molten material can comprise scrap, in particular scrap metal material. The molten material can comprise aluminum, copper, silver, gold or any other metallic material that can be heated and / or molten with electrical energy.

[0035] The electrodes can be made of high-density graphite and / or tungsten. The electrodes can be designed to transfer electrical energy, thereby forming an arc between their tips and the charge material. The electrodes can be prebaked electrodes or self-baking electrodes (Soederberg electrodes) and / or extruded / composite electrodes, which are a combination of Soederberg electrodes with a prebaked electrode and / or a hollow electrode system as a core, whereby the choice of electrode type can depend on the size of the electrode, the material / metallurgy produced and / or economic aspects such as operating costs.

[0036] The electrode positioning device can comprise a height adjustment device configured to move at least one electrode of the electric furnace closer to or further away from the molten material in the electric furnace. The height adjustment device can use an electric winch crane, a hydraulic cylinder, a pneumatic cylinder, a direct electromechanical drive comprising an electric motor and / or a gear, etc. In this way, the position of the at least one electrode can be adjusted faster and with higher accuracy.

[0037] The power supply device can comprise a plurality of converters configured to supply power to at least one electrode of the electric furnace.

[0038] The power supply device can comprise a plurality of DC-AC converters and / or AC-DC-AC converters configured to supply power to at least one electrode of the electric furnace. In this way, the electric furnace can be operated with alternating current, in particular with multi-phase alternating current.

[0039] The power supply device can comprise a plurality of AC-DC converters and / or DC-DC converters and / or DC choppers configured to supply power to at least one electrode of the electric furnace. In this way, the electric furnace can be operated with direct current.

[0040] The electronic control device can be any electronic system that is adapted to receive signals and / or that is adapted to store signals and / or that is adapted to process signals and / or that is adapted to transmit signals. The electronic control device can be any electronic system that is adapted to control and / or to adjust the power supply device depending on at least one signal and / or that is adapted to control and / or to adjust the electrode positioning device depending on at least one signal.

[0041] The electric furnace can comprise one or more sensors to provide information about the harmonic distortion and / or flicker and / or the ratio of active power flow to reactive power flow in the power supply network and / or at least one operating characteristic of the electric furnace. The electronic control device can be operably connected to one or more such sensors and be capable of receiving sensor signals, processing these sensor signals and using these sensor signals to control and / or regulate the power supply device and / or the electrode positioning device.

[0042] The one or more sensors can be sensors that measure one or more measurement quantities using optical measuring devices and / or electrical measuring devices and / or magnetic measuring devices and / or mechanical measuring devices and / or magnetostrictive measuring devices in order to provide sensor signals to the electronic control device.

[0043] The one or more measurement quantities can directly and / or indirectly correspond to the harmonic distortion and / or flicker and / or the ratio of active power flow to reactive power flow in the power supply network and / or at least one actual operating characteristic of the electric furnace. In this way, the positioning of the sensors within the electric furnace can be more flexible.

[0044] For example, if the at least one actual operating characteristic is the current, the at least one measurement quantity can directly correspond to the current. In other words, the measurement quantity can be the current.

[0045] For example, if the at least one actual operating characteristic is the electrode position, the at least one measurement quantity can indirectly correspond to the electrode position. In other words, the measurement quantity can be the pressure in a hydraulic cylinder for positioning at least one electrode, wherein the pressure in the hydraulic cylinder corresponds to a specific electrode position relative to the molten material in the electric furnace.

[0046] The electronic control device can comprise a storage element configured to store sensor signals received by the one or more sensors from the electric furnace.

[0047] The electronic control device can comprise a housing. The electronic control unit can be an integrated component.

[0048] In the context of the present invention, the housing is designed to protect the designated components inside from external influences, in particular from mechanical and / or electrical influences. Furthermore, the housing can be provided with an electrical ground connection, so that the housing can increase the safety of personnel in the vicinity of the electrical components enclosed by the housing in a designated manner.

[0049] The housing can comprise a bottom portion, a top portion and at least one side portion. The bottom portion, the top portion and the at least one side portion can at least partially limit the housing volume. The bottom portion, the top portion and the at least one side portion can be connected to one another, thereby forming an integrated component.

[0050] The two parts forming the integrated component are interconnected to each other by means of at least one mechanical connection in the context of the present invention. In other words, when the integrated component is moved from one spatial position to another spatial position, the two parts forming the integrated component change their spatial position relative to each other within the range of their mechanical connection.

[0051] In a preferred embodiment of the present invention, the mechanical connection of the integrated component is fixed. In other words, the relative position of the two parts forming the integrated component is constant during a change of the spatial position of the integrated component, wherein the mechanical connection between the two parts is fixed.

[0052] The model predictive calculation is based on mathematical formulas to describe the functionality and physical correlations of an electric furnace known to the person skilled in the art during the melting process of the melting material.

[0053] The operational characteristic can be any characteristic of the electric furnace during operation of the electric furnace. For example, the operational characteristic can be the voltage, the current, the electric frequency, the electrode position, etc.

[0054] The target curve of the operational characteristic is a predetermined curve of the operational characteristic, which is calculated in order to achieve a specific result of the melting process.

[0055] The time range can be any amount of time, in particular from the beginning of the melting process until the end of the melting process.

[0056] The result to be achieved of the melting process can apply to the entire melting process and / or to specific operational steps of a melting cycle of the melting process. For example, minimizing the electrical energy required to heat a specific amount of melting material to a predetermined temperature can apply to the entire melting process and / or to specific operational steps of a melting cycle of the melting process. Different operational steps of a melting cycle of the melting process can comprise different results to be achieved. For example, in an operational step of perforating the melting material in order to start the melting process, the result to be achieved can be to minimize the time required to heat the melting material to a predetermined temperature. In a subsequent operational step of forming a melt pool of the melting material, the result to be achieved can be to minimize the electrical energy required to heat the melting material to a predetermined temperature. A method designed in this way has the advantage that the energy efficiency and the time efficiency of the melting process can be improved, while at the same time the quality of the melting material at the furnace outlet can be improved.

[0057] More preferably, the method is designed to include a method step for determining at least one actual operating characteristic, which is supplied to at least one electrode at a first time by means of an electrode positioning device and / or a power supply device, and a method step for performing a model prediction calculation of a target curve of the at least one operating characteristic up to a time range, in such a way that the target curve of the at least one operating characteristic at the first time is equal to the actual operating characteristic at the first time.

[0058] In this way, the overall control and regulation of the electric furnace can be improved. The target curve of at least one operating characteristic is continuously updated, thus allowing for more precise control and regulation of that at least one operating characteristic, even taking into account sudden changes in conditions within the furnace during the melting process. In fact, the target curve is no longer a static target curve as known from the prior art, but is continuously calculated throughout the melting process, thereby improving the control and regulation of the electric furnace based on predictive control and regulation rather than on traditional correction-based control and regulation.

[0059] The method steps for determining at least one actual operational characteristic at a first moment can be performed by means of at least one sensor.

[0060] More preferably, the method is designed to include a method step for setting at least one operational characteristic in such a way that the at least one operational characteristic is on the target curve at a second time, which is after the first time.

[0061] In this way, the method has the following advantages: it can even further improve the overall control and regulation of the electric furnace, because at least one operating characteristic can follow the target curve more quickly, thus allowing for an increase in control and regulation speed.

[0062] The characteristic of the second time being after the first time in terms of time can also be expressed as the second time being after or downstream of the first time in terms of time.

[0063] More preferably, the method is designed to include a method step for determining at least one actual operating characteristic, which is supplied to at least one electrode at a third time by means of an electrode positioning device and / or a power supply device, the third time being temporally after the second time, and performing a method step for performing a model prediction calculation of a target curve of the at least one operating characteristic up to a time range, in such a way that the target curve of the at least one operating characteristic at the third time is equal to the actual operating characteristic at the third time.

[0064] In this way, the method has the following advantages: it can further improve the overall control and regulation of the electric furnace because the target curve of at least one operating characteristic is continuously updated, and therefore sudden changes in conditions within the furnace during the melting process are also taken into account. Such changes can be, but are not limited to, sudden changes in electrode position relative to the molten material due to the collapse of the molten material during the melting process.

[0065] The characteristic of the third time being after the second time in terms of time can also be expressed as the third time being after or downstream of the second time in terms of time.

[0066] More preferably, the method is designed to include a method step for setting at least one operational characteristic such that the at least one operational characteristic is on the target curve at a fourth time, which is after the third time.

[0067] In this way, the method has the following advantages: the overall control and regulation of the electric furnace can be further improved, because at least one operating characteristic can follow the target curve more quickly, thereby allowing for an increase in the speed of control and regulation.

[0068] The characteristic that the fourth time is after the third time in terms of time can also be expressed as the fourth time being after or downstream of the third time in terms of time.

[0069] The first, second, third, and fourth times can fall within the time range.

[0070] The above-described steps can be continued continuously throughout the melting process over a period of time.

[0071] More preferably, the method is designed to have the following method steps:

[0072] - Based on the desired results of the melting process, perform model prediction calculations for the target curves of n operational characteristics up to the time range; and

[0073] - Using an electrode positioning device and / or a power supply device, n operating characteristics are set in such a way that the corresponding n operating characteristics are located on the corresponding target curve associated with the corresponding operating characteristics at a predetermined future time point.

[0074] In this way, the method has the following advantages: it improves the overall control and regulation of the electric furnace by achieving simultaneous control and regulation of multiple operating characteristics.

[0075] The number of operating characteristics n is not limited to a specific value and can be any integer. For example, n can be equal to or greater than 2, preferably equal to or greater than 5, and particularly preferably equal to or greater than 35. In a preferred embodiment, the number of operating characteristics n can be equal to 4.

[0076] More preferably, the method is designed to include method steps for determining n actual operating characteristics, which are supplied to at least one electrode at a first time by means of an electrode positioning device and / or a power supply device, and to perform method steps for model prediction calculation of the corresponding target curves of the n operating characteristics up to a time range, in such a way that the corresponding target curve of the corresponding operating characteristic at the first time is equal to the corresponding actual operating characteristic at the first time.

[0077] In this way, the method has the following advantages: it can further improve the overall control and regulation of the electric furnace because the target curves of n operating characteristics are continuously updated, and therefore sudden changes in conditions within the furnace during the melting process are also taken into account. Such changes can be, but are not limited to, sudden changes in electrode position relative to the molten material due to the collapse of the molten material during the melting process.

[0078] More preferably, the method is designed to have method steps for setting n operational characteristics in such a way that the n operational characteristics are on the corresponding target curve at a second time, the second time being after the first time.

[0079] In this way, the method has the following advantages: it can even further improve the overall control and regulation of the electric furnace, because the n operating characteristics can follow the target curve more quickly, thus allowing for increased control and regulation speed.

[0080] More preferably, the method is designed to include method steps for determining n actual operating characteristics, which are supplied to at least one electrode at a third time by means of an electrode positioning device and / or a power supply device, the third time being temporally after the second time, and performing method steps for model prediction calculations of corresponding target curves for the n operating characteristics up to the time range, in such a way that the corresponding target curve of the corresponding operating characteristic at the third time is equal to the corresponding actual operating characteristic at the third time.

[0081] In this way, the method has the following advantages: it can further improve the overall control and regulation of the electric furnace because the target curves of n operating characteristics are continuously updated, and therefore sudden changes in conditions within the furnace during the melting process are also taken into account. Furthermore, the target curves of the n operating characteristics are updated continuously over a time span, thus allowing for increased control and regulation speed over extended time periods.

[0082] More preferably, the method is designed to have method steps for setting n operational characteristics in such a way that the n operational characteristics are on the corresponding target curve at a fourth time, the fourth time being after the third time.

[0083] In this way, the method has the following advantages: it can even further improve the overall control and regulation of the electric furnace, because the n operating characteristics can follow the target curve more quickly and continuously within the time range, thus allowing for increased control and regulation speed.

[0084] More preferably, the method is designed such that at least one operating characteristic and / or at least one actual operating characteristic is voltage.

[0085] In this way, the method has the advantage of allowing instantaneous control and regulation of the power supplied to at least one electrode.

[0086] The voltage can be the voltage applied to at least one electrode.

[0087] More preferably, the method is designed such that at least one operating characteristic and / or at least one actual operating characteristic is current.

[0088] In this way, the method has the advantage of allowing instantaneous control and regulation of the power supplied to at least one electrode.

[0089] The current can be the current supplied to at least one electrode.

[0090] More preferably, the method is designed such that at least one operating characteristic and / or at least one actual operating characteristic is an electrical frequency.

[0091] In this way, the method has the advantage of increasing the power factor of the electricity flowing through at least one electrode by allowing instantaneous control and regulation of the ratio of active power flow to reactive power flow supplied to at least one electrode.

[0092] The electrical frequency can be the electrical frequency applied to at least one electrode.

[0093] More preferably, the method is designed such that at least one operating characteristic and / or at least one actual operating characteristic is the electrode location of at least one electrode.

[0094] In this way, the method has the following advantages: it can significantly reduce the wear of at least one electrode.

[0095] The electrode position can be the vertical position relative to the molten material inside the electric furnace.

[0096] More preferably, the method is designed such that the model prediction calculation of at least one target curve for at least one operating characteristic is based on a discrete-time dynamic model of the melting process of the molten material in the electric furnace, wherein the time interval between two consecutive time steps is less than or equal to 0.1 s.

[0097] In this way, the method has the following advantages: because at least one actual operating characteristic can be determined and at least one operating characteristic can be set with higher sampling resolution, the accuracy of the control and regulation of the electric furnace is improved.

[0098] Preferably, the time interval between two consecutive time steps in the time dynamic model of the melting process of the molten material is less than or equal to 0.01 s, more preferably less than or equal to 0.001 s, and particularly preferably less than or equal to 0.0005 s. In this way, the method has the advantage of further improving the accuracy of the control and regulation of the electric furnace, because determining at least one actual characteristic and setting at least one operating characteristic can be done at even higher sampling resolution.

[0099] According to a preferred embodiment, the time interval between two consecutive time steps in the time dynamic model of the melting process of the molten material is greater than or equal to 0.0001s, more preferably greater than or equal to 0.0005s, and particularly preferably greater than or equal to 0.001s.

[0100] According to a preferred embodiment, the time interval between two consecutive time steps in the time dynamic model of the melting process of the molten material is in the time range of 0.0002s to 0.1s, preferably in the time range of 0.001s to 0.1s, and particularly preferably in the time range of 0.01s to 0.1s.

[0101] More preferably, the method is designed such that the desired result of the melting process is selected from the group consisting of:

[0102] - To minimize the electrical energy required to heat the molten material to a predetermined temperature;

[0103] - To minimize the time required to heat the molten material to a predetermined temperature; and

[0104] - To minimize wear on the at least one electrode used to heat molten material to a predetermined temperature.

[0105] In this way, the method has the following advantages: it can reduce the overall operating cost of the melting process of materials in an electric furnace, while increasing the service life of the electric furnace.

[0106] In a preferred embodiment, the method is designed such that the desired result of the melting process is selected from the group consisting of:

[0107] - To minimize and / or even out wear on the refractory container of the electric furnace;

[0108] - To minimize and / or even out wear on the furnace panel;

[0109] - To minimize and / or even out wear on the bottom shell of the refractory container of the electric furnace;

[0110] - To minimize and / or even out wear on the slag door of the electric furnace;

[0111] - To minimize and / or even out wear on the top cover of the electric furnace;

[0112] - Optimize the reheating of the raw material discharge and / or injection and / or tapping zones within the electric furnace vessel, especially the eccentric bottom tapping zone;

[0113] - Optimize the reheating of the chemical additive material discharge zone and / or chemical additive material injection zone within the electric furnace vessel; and

[0114] - Optimize the reheating of the slag gate area within the electric furnace vessel; and

[0115] - To minimize harmonic distortion and / or flicker in the power grid; and

[0116] - Maximize the ratio of active power flow to reactive power flow in the power supply network.

[0117] Evenly distributing wear across a specific part of an electric furnace can be understood as ensuring that the wear on a given surface of that specific part of the furnace is substantially uniform. This, in turn, extends the overall service life of the electric furnace.

[0118] The present invention further addresses this problem by providing an electric furnace in which the instantaneous variability of power absorption during the melting process of the molten material is reduced.

[0119] This problem of the present invention is solved by the electric furnace according to claim 17.

[0120] More specifically, the fundamental problem of the present invention is solved by an electric furnace for melting materials, wherein the furnace includes an electrode positioning device for positioning at least one electrode of the furnace. The furnace also includes a power supply device for supplying power to the at least one electrode. Furthermore, the furnace includes an electronic control device that is data-coupled to the electrode positioning device and the power supply device for signal transmission. The furnace is characterized in that the electronic control device is adapted to regulate the operation of the furnace during the melting process of the material according to any of the methods described above. Attached Figure Description

[0121] Further advantages, details and features of the invention are explained in the following description of embodiments, thereby:

[0122] Figure 1 A flowchart is shown of a first embodiment of a method for regulating the operation of an electric furnace during the melting process of molten material;

[0123] Figure 2 A flowchart of a second embodiment of a method for regulating the operation of an electric furnace during the melting process of molten material is shown.

[0124] Figure 3 The graph shows the target curves of the electric furnace's operating characteristics over the time range N during the melting process, based on the desired results and the actual operating characteristics up to the first time t1.

[0125] Figure 4 The graph shows the target curve of the electric furnace's operating characteristics over the time range N during the melting process, based on the desired results and the actual operating characteristics up to the second time t2.

[0126] Figure 5 The graph shows the target curves of the electric furnace's operating characteristics over the time range N during the melting process, based on the desired results and the actual operating characteristics up to the fourth time t4; and

[0127] Figure 6 A schematic diagram of an electric furnace for melting materials according to a first embodiment is shown. Detailed Implementation

[0128] In the following description, the same reference numerals describe the same elements and the same features respectively, such that a description of an element with reference to one figure is also valid for other figures, thus omitting the repetition of corresponding features.

[0129] Figure 1 A flowchart of a first embodiment of a method for regulating the operation of an electric furnace 10 during the melting process of molten material is shown. Figure 6 The electric furnace 10 shown includes an electrode positioning device 30 for positioning at least one electrode 40 of the electric furnace 10, a power supply device 50 for supplying power to the at least one electrode 40, and an electronic control device 60 for data coupling to the electrode positioning device 30 and the power supply device 50 for transmitting signals.

[0130] This method includes the following steps:

[0131] -Based on the results to be achieved in the melting process, perform model prediction calculation S1 for the target curve of at least one operating characteristic Op up to the time range N;

[0132] - By means of electrode positioning device 30 and / or power supply device 50, at least one operating characteristic Op of S2 is set in such a way that at least one operating characteristic Op is located on the target curve of at least one operating characteristic Op at a predetermined future time point;

[0133] - Determine at least one actual operating characteristic Oap of S3, which is supplied to at least one electrode 40 at a first time t1 by means of electrode positioning device 30 and / or power supply device 50.

[0134] The method step of performing model prediction calculation S1 on the target curve of at least one operating characteristic Op up to the time range N is such that the target curve of at least one operating characteristic Op at the first time t1 is equal to the actual operating characteristic Op at the first time t1.

[0135] The method also includes the following method steps:

[0136] - Set at least one operational characteristic Op in S4 such that at least one operational characteristic Op is on the target curve at a second time t2, which is after the first time t1 in time.

[0137] - Determine at least one actual operating characteristic Oap of S5, which is supplied to at least one electrode 40 at a third time t3 by means of electrode positioning device 30 and / or power supply device 50, the third time t3 being temporally after the second time t2.

[0138] Specifically, S1 involves performing model prediction calculations S1 on the target curve of at least one operational characteristic Op up to the time range N, in such a way that the target curve of at least one operational characteristic Op at the third time t3 is equal to the actual operational characteristic Oap at the third time t3.

[0139] - Set at least one operating characteristic Op in S6 such that at least one operating characteristic Op is on the target curve at the fourth time t4, which is after the third time t3 in time.

[0140] Figure 2 A flowchart of a second embodiment of a method for regulating the operation of an electric furnace 10 during the melting process of molten material is shown.

[0141] This method includes the following steps:

[0142] -Based on the results to be achieved in the melting process, perform model prediction calculations S7 for the target curves of n operational characteristics Op up to the time range N;

[0143] - Using electrode positioning device 30 and / or power supply device 50, the n operating characteristics Op are set in such a way that the corresponding n operating characteristics Op are located on the corresponding target curve associated with the corresponding operating characteristic Op at a predetermined future time point, and

[0144] -S9 n actual operating characteristics Oap are determined, which are supplied to at least one electrode 40 at a first time t1 by means of electrode positioning device 30 and / or power supply device 50.

[0145] The method step S7, which involves performing model prediction calculations on the target curves of n operational characteristics Op up to the time range N, is to make the target curve of the corresponding operational characteristic Op at the first time t1 equal to the actual operational characteristic Op at the first time t1.

[0146] The method also includes the following method steps:

[0147] - Set up n operational characteristics Op in S10 such that the n operational characteristics Op are on the corresponding target curve at the second time t2, and the second time is after the first time t1 in time.

[0148] - Determine S11 n actual operating characteristics Oap, which are supplied to at least one electrode 40 at a third time t3 by means of electrode positioning device 30 and / or power supply device 50, the third time t3 being temporally after the second time t2, wherein the method step S7 of performing model prediction calculation of the corresponding target curves of the n operating characteristics Op up to the time range N is performed in such a way that the corresponding target curve of the corresponding operating characteristic Op at the third time t3 is equal to the corresponding actual operating characteristic Oap at the third time t3, and

[0149] - Set up n operational characteristics Op in S12, such that the n operational characteristics Op are on the corresponding target curve at the fourth time t4, which is after the third time t3 in time.

[0150] Figure 3 A graph showing the target curves of the electric furnace's operating characteristics over a time range N during the melting process, based on the desired results and the actual operating characteristics up to the first time t1.

[0151] In the method step S1 of model prediction calculation, a target curve for at least one operating characteristic Op up to a time range N is calculated. In method step S2, at least one operating characteristic Op is set by means of an electrode positioning device 30 and / or a power supply device 50 such that at least one operating characteristic Op lies on the target curve of at least one operating characteristic Op at a predetermined future time point. This is indicated by the first "x" in the graph when counting the number of "x"s starting from the left side.

[0152] In method step S3, at least one actual characteristic Op is determined to be supplied to at least one positioning device 30 and / or power supply device 50 at a first time t1. Then, method step S1 is performed to perform model prediction calculation of the target curve of the at least one operating characteristic Op up to a time range N, such that the target curve of the at least one operating characteristic Op at the first time t1 is equal to the actual operating characteristic Op at the first time t1. This is shown by the second "x" in the figure. As can be seen, the actual operating characteristic Op and the target curve of the operating characteristic Op coincide at the first time t1. In this way, the target curve of the operating characteristic Op is continuously updated throughout the melting process of the molten material, taking into account the actual operating characteristic Op. This leads to more accurate control and regulation of the operating characteristics, and thus to an overall improvement in the efficiency of the melting process.

[0153] Figure 4 A graph showing the target curves of the electric furnace's operating characteristics over the time range N during the melting process, based on the desired results and the actual operating characteristics up to the second time t2.

[0154] In method step S4, at least one operational characteristic Op is set such that at least one operational characteristic Op is on the target curve at a second time t2, which is after the first time t1. This is shown as the third "x" in the figure.

[0155] Figure 5 A graph showing the target curves of the electric furnace's operating characteristics over the time range N during the melting process, based on the desired results and the actual operating characteristics up to the fourth time t4.

[0156] In method step S5, at least one actual characteristic Oap is determined, which is supplied to at least one positioning device 30 and / or power supply device 50 at a third time t3, after the second time t2. Then, method step S1, which involves model prediction calculation of the target curve of the at least one operating characteristic Op up to the time range N, is performed such that the target curve of the at least one operating characteristic Op at the third time t3 is equal to the actual operating characteristic Oap at the third time t3. This is indicated by the fourth "x" in the figure. As can be seen, the actual operating characteristic Oap and the target curve of the operating characteristic Op coincide at the third time t3. In this way, the target curve of the operating characteristic Op is continuously updated throughout the melting process of the molten material, taking into account the actual operating characteristic Oap.

[0157] In method step S6, at least one operational characteristic Op is set such that at least one operational characteristic Op is on the target curve at a fourth time t4, which is after the third time t3. This is indicated by the fifth "x" in the figure.

[0158] Figure 6 A schematic diagram of an electric furnace 10 for melting material according to a first embodiment is shown. The electric furnace 10 includes two electrode positioning devices 30 for positioning two electrodes 40 of the furnace 10. Each electrode positioning device 30 is connected to only one electrode 40, and each electrode 40 is connected to only one electrode positioning device 30. The electrodes 40 are positioned in a furnace container 70 containing the material to be melted. The electric furnace 10 also includes a power supply device 50 for supplying power to the two electrodes 40. The power supply device 50 is connected to the two electrodes 40. The electric furnace 10 also includes an electronic control device 60, wherein the electronic control device 60 is data-coupled to the two electrode positioning devices 30 and the power supply device 50 for signal transmission. The electrode control device 60 is also adapted to regulate the operation of the electric furnace 10 during the melting process of the material according to the method described above for regulating the operation of the electric furnace 10 during the melting process of the material.

[0159] List of reference numerals

[0160] 10 Electric Furnaces

[0161] 30 Electrode positioning device

[0162] 40 electrodes

[0163] 50 Power supply equipment

[0164] 60 Electronic control device

[0165] 70 furnace containers

[0166] Op operation characteristics

[0167] Oap Practical Operational Characteristics

[0168] N Time range

[0169] Up voltage

[0170] Ip current

[0171] Fp electrical frequency

[0172] t1 First Time

[0173] t2 Second Time

[0174] t3 Third Time

[0175] t4 Fourth Time

[0176] S1 Method Steps

[0177] S2 Method Steps S2

[0178] S3 Method Steps

[0179] S4 Method Steps

[0180] S5 Method Steps

[0181] S6 Method Steps

[0182] S7 Method Steps S7

[0183] S8 Method Steps S8

[0184] S9 Method Steps

[0185] S10 Method and Steps S10

[0186] S11 Method and Steps S11

[0187] S12 Method Steps S12

Claims

1. A method for regulating the operation of an electric furnace (10) during the melting process of a molten material, the electric furnace (10) comprising: -Electrode positioning device (30), the electrode positioning device being used to position at least one electrode (40) of the electric furnace (10); - Power supply device (50), the power supply device being used to supply power to the at least one electrode (40); and - An electronic control device (60), which is data coupled to the electrode positioning device (30) and the power supply device (50) for signal transmission. The method includes the following steps: -Based on the results to be achieved in the melting process, a model prediction calculation (S1) is performed on the target curve of at least one operating characteristic (Op) up to the time range (N). as well as - The at least one operating characteristic (Op) is set (S2) by means of the electrode positioning device (30) and / or the power supply device (50) in such a way that the at least one operating characteristic (Op) is located on the target curve of the at least one operating characteristic (Op) at a predetermined future time point.

2. The method according to claim 1, characterized in that, The method has method steps for determining (S3) at least one actual operating characteristic (Oap), which is supplied to the at least one electrode (40) at a first time (t1) by means of the electrode positioning device (30) and / or the power supply device (50), and - A method step of performing model prediction calculation (S1) on the target curve of the at least one operating characteristic (Op) up to the time range (N), in such a way that the target curve of the at least one operating characteristic (Op) at the first time (t1) is equal to the actual operating characteristic (Oap) at the first time (t1).

3. The method according to claim 2, characterized in that, The method comprises the following steps: - Set (S4) the at least one operating characteristic (Op) such that the at least one operating characteristic (Op) is on the target curve at a second time (t2), the second time being after the first time (t1).

4. The method according to claim 3, characterized in that, The method has method steps for determining (S5) at least one actual operating characteristic (Oap), which is supplied to the at least one electrode (40) at a third time (t3) by means of the electrode positioning device (30) and / or the power supply device (50), the third time (t3) being temporally after the second time (t2), and - A method step of performing model prediction calculation (S1) on the target curve of the at least one operating characteristic (Op) up to the time range (N), in such a way that the target curve of the at least one operating characteristic (Op) at the third time (t3) is equal to the actual operating characteristic (Oap) at the third time (t3).

5. The method according to claim 4, characterized in that, The method comprises the following steps: - Set (S6) the at least one operating characteristic (Op) such that the at least one operating characteristic (Op) is on the target curve at a fourth time (t4), the fourth time being after the third time (t3).

6. The method according to any one of the preceding claims, characterized in that... The following are the steps: -Based on the results to be achieved in the melting process, the target curves of n operating characteristics (Op) up to the time range (N) are calculated using a model (S7); as well as - The n operating characteristics (Op) are set (S8) by means of the electrode positioning device (30) and / or the power supply device (50) in such a way that the corresponding n operating characteristics (Op) are located on the corresponding target curve associated with the corresponding operating characteristic (Op) at a predetermined future time point.

7. The method according to claim 6, characterized in that, The method has method steps for determining (S9) n actual operating characteristics (Oap), which are supplied to the at least one electrode (40) at a first time (t1) by means of the electrode positioning device (30) and / or the power supply device (50), and - A method step of performing model prediction calculations (S7) on the corresponding target curves of the n operating characteristics (Op) up to the time range (N), in such a way that the corresponding target curve of the corresponding operating characteristic (Op) at the first time (t1) is equal to the corresponding actual operating characteristic (Oap) at the first time (t1).

8. The method according to claim 7, characterized in that, The method comprises the following steps: - Set (S10) the n operational characteristics (Op) in such a way that the n operational characteristics (Op) are on the corresponding target curve at a second time (t2), the second time being after the first time (t1).

9. The method according to claim 8, characterized in that, The method has method steps for determining (S11) n actual operating characteristics (Oap), which are supplied to the at least one electrode (40) at a third time (t3) by means of the electrode positioning device (30) and / or the power supply device (50), the third time (t3) being temporally after the second time (t2), and - A method step of performing model prediction calculations (S7) on the corresponding target curves of the n operating characteristics (Op) up to the time range (N), in such a way that the corresponding target curve of the corresponding operating characteristic (Op) at the third time (t3) is equal to the corresponding actual operating characteristic (Oap) at the third time (t3).

10. The method according to claim 9, characterized in that, The method comprises the following steps: - Set (S12) the n operational characteristics (Op) in such a way that the n operational characteristics (Op) are on the corresponding target curve at a fourth time (t4), the fourth time being after the third time (t3).

11. The method according to any one of the preceding claims, characterized in that, At least one operating characteristic (Op) and / or at least one actual operating characteristic (Oap) is voltage (Up).

12. The method according to any one of the preceding claims, characterized in that, At least one operating characteristic (Op) and / or at least one actual operating characteristic (Oap) is current (Ip).

13. The method according to any one of the preceding claims, characterized in that, At least one operating characteristic (Op) and / or at least one actual operating characteristic (Oap) is an electrical frequency (Fp).

14. The method according to any one of the preceding claims, characterized in that, At least one operating characteristic (Op) and / or at least one actual operating characteristic (Oap) is the electrode position of the at least one electrode (40).

15. The method according to any one of the preceding claims, characterized in that, The model prediction calculation for the at least one target curve of the at least one operating characteristic (Op) is based on a discrete-time dynamic model of the melting process of the molten material in the electric furnace (10), wherein the time interval between two consecutive time steps is less than or equal to 0.1s.

16. The method according to any one of the preceding claims, characterized in that, The desired result of the melting process is selected from the group consisting of: - To minimize the electrical energy required to heat the molten material to a predetermined temperature; - To minimize the time required to heat the molten material to a predetermined temperature; as well as - Minimize wear on the at least one electrode (40) used to heat the molten material to a predetermined temperature.

17. An electric furnace (10) for melting materials, said electric furnace (10) comprising: -Electrode positioning device (30), the electrode positioning device being used to position at least one electrode (40) of the electric furnace (10); - Power supply device (50), the power supply device being used to supply power to the at least one electrode (40); and - An electronic control device (60), which is data coupled to the electrode positioning device (30) and the power supply device (50) for signal transmission. The electric furnace (10) is characterized in that the electronic control device (60) is adapted to adjust the operation of the electric furnace (10) during the melting process of the molten material according to any one of the preceding claims.

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