Submerged arc furnace electrode position APC advanced process control method

Abstract

The invention belongs to the technical field of submerged arc furnace smelting, and relates to a submerged arc furnace electrode position APC advanced process control method which is applied to submerged arc furnace electrode equipment and comprises the steps that the electrode position, electrode electrical parameters, hearth pressure and pressure release data of a submerged arc furnace are collected to serve as an original data set; preprocessing data in the original data set through a mean filtering method; establishing a working condition identification program according to data in the original data set; establishing a transfer function model based on a single-input single-output system of electrode lifting; and designing a submerged arc furnace electrode lifting control mode according to different working conditions. According to the invention, advanced lifting process control of the submerged arc furnace electrode equipment is realized; three electrode lifting control modes are developed, and control optimization is carried out aiming at special working conditions; the application of the GPC generalized predictive control technology enhances the technical reserve of advanced control practical application.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ore smelting furnace, and particularly relates to an advanced process control method for electrode position of ore smelting furnace. BACKGROUND

[0002] In the production process of the ore smelting furnace, the smelting production is realized by adjusting the three-phase electrode position. Traditionally, the Bang-bang control method is used to realize the automatic control of the electrode. The smelting working condition of the ore smelting furnace is relatively complex, and frequent disturbances to the automatic control of the electrode can be caused by the collapse and pressure release and the like. The Bang-bang control aims at rapid adjustment, and if there is a deviation in the control input, the electrode will be in action until the deviation is eliminated, which can cause the electrode to frequently act due to the disturbance, and has a certain negative impact on the stable production of the ore smelting furnace. At the same time, traditionally, there are only two kinds of control inputs, i.e. the electrode current and the operating resistance, and the automatic control of the electrode active power has not been realized. Therefore, it is necessary to provide an automatic control method for the electrode lifting of the ore smelting furnace, so as to improve the intelligent level of the ore smelting furnace as a whole. SUMMARY

[0003] According to the above technical problem, an advanced process control method for the electrode position of the ore smelting furnace is provided. The present application takes the long-term running trend of the target object as the control purpose, adopts the generalized predictive control mode for the long time delay and large inertia object, and makes identification processing for the common disturbance, so as to solve the problem of frequent action of the traditional automatic control of the electrode of the ore smelting furnace. At the same time, in order to solve the problem of the deviation of the electrode active power in the electrode current and operating resistance control mode in practice, the electrode active power mode is developed, so that the electrode lifting automatic control system can cover more kinds of working conditions.

[0004] The technical means adopted by the present application is as follows: The advanced process control method for the electrode position of the ore smelting furnace is applied to the electrode equipment of the ore smelting furnace, and comprises the following steps: Collecting the electrode position, electrode electric parameter, hearth pressure and pressure release data of the ore smelting furnace as the original data set; Preprocessing the data in the original data set by the mean filtering method; Establishing a working condition identification program according to the data in the original data set; Establishing a transfer function model based on the single-input single-output system of the electrode lifting; Designing the GPC generalized predictive control mode of the electrode lifting of the ore smelting furnace according to different working conditions.

[0005] Further, the working condition identification program identifies the collapse through the hearth pressure, and when the collapse occurs, the control output is inhibited. When the electrode is pressure released, the working condition identification program inhibits the control output, so as to avoid the adjustment action from causing overshoot.

[0006] Furthermore, the working condition identification program adopts a deburring program to eliminate abnormal disturbances, and replaces the disturbance value with a filtered value through threshold and delayed output deburring judgment, thereby avoiding excessive response due to disturbances while ensuring control accuracy.

[0007] Furthermore, the transfer function model is described using a controlled autoregressive integrated moving average model, and the model to be identified is:

[0008] in, represents the backshift operator, represents an autoregressive polynomial, represents the input / control polynomial, Indicates that the system is Output at any moment, Indicates that the system is The control input at the moment, represents the pure time delay of the system, represents the random disturbance term, represents the backward difference operator.

[0009] Furthermore, the GPC generalized predictive control mode includes a current mode, a resistance mode and an active power mode, wherein: The current mode is used to limit current under high load to prevent overburning and electrode edge conditions, with electrode current as the control input and feedback, and electrode position as the control output; the resistance mode is used for conditions where the load is frequently adjusted, with operating resistance as the control input and feedback, and electrode position as the control output; the active power mode is used for conditions where the load is stable, with electrode active power as the control input and feedback, and electrode position as the control output; The control input of the GPC generalized predictive control loop is selected according to the control mode, and the control output electrode position command is output to the industrial control system to execute the electrode action, and the feedback value is obtained after the electrode action.

[0010] Compared with the prior art, the present invention has the following advantages: The APC advanced process control method for the electrode position of an ore-bearing furnace provided by the present invention realizes the advanced process control of the lifting and lowering of the electrode equipment of the ore-bearing furnace; develops three electrode lifting control modes; optimizes control for special working conditions; and applies GPC generalized predictive control technology to enhance the technical reserves for the practical application of advanced control.

[0011] The method for advanced process control of the electrode position of the ore-heating furnace can realize automatic control of the ore-heating furnace lifting and has the following characteristics: the GPC (generalized predictive control) method is used to control the electrode lifting, the generalized predictive control mode is used for the long time delay and large inertia object such as the ore-heating furnace electrode, the output response is slow, the long-term running trend of the target object is used as the control purpose, and the control disturbance caused by the frequent action of the electrode is reduced; three electrode lifting control modes are developed, the control input is the electrode current, the operation resistance and the electrode active power respectively, and the control output is the electrode position, so as to adapt to various complex working conditions of the ore-heating furnace; the data preprocessing such as spike elimination and filtering is adopted for the control parameters of the special working condition, the control response under the special working condition is optimized; the alarm and safety interlocking are optimized, the auxiliary fault diagnosis is realized, the equipment maintenance is in place and timely, and the production efficiency and economic benefits are improved.

[0012] Based on the above reasons, the present application can be widely popularized in the field of ore-heating furnace smelting technology. BRIEF DESCRIPTION OF DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0014] Figure 1 The flow chart of the method for advanced process control of the electrode position of the ore-heating furnace in the present application.

[0015] Figure 2 The flow chart of the deburring algorithm in the present application.

[0016] Figure 3 The control mode selection schematic diagram in the present application.

[0017] Figure 4 The GPC (generalized predictive control) loop schematic diagram in the present application. DETAILED DESCRIPTION

[0018] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0019] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. The following description of at least one example embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0020] It should be noted that the terms used herein are only intended to describe specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form, unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, there is a feature, step, operation, device, component and / or combination thereof.

[0021] Unless specifically stated otherwise, the relative arrangement of components and steps, numerical expressions, and numerical values set forth in the various embodiments described herein are not meant to limit the scope of the present application. It should also be understood that the size of the various parts shown in the drawings is not necessarily to scale. Techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered as part of the specification, if appropriate. In all examples shown and discussed herein, any specific value should be interpreted as merely illustrative, and not as a limitation. Thus, other examples of the exemplary embodiments can have different values. It should be noted that like reference numerals and letters in the following drawings represent similar items, and therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0022] As Figure 1 As shown in the figure, the present application provides a method for advanced process control of the position of a furnace electrode, which is applied to a furnace electrode device. The furnace electrode device forms mainly in three types, which are combined holder, corrugated pipe pressure ring holder and graphite electrode holder. The three electrode devices are all controlled by hydraulic pressure to lift the electrode, and are installed with an electrode position indicator to feedback the electrode position signal. A complete power detection system for the furnace is used to collect data such as electrode current, operating resistance and active power of the electrode for control.

[0023] Collecting the electrode position, electrode electric parameter, hearth pressure and pressure drop data of the ore smelting furnace as the original data set; the data in the original data set is preprocessed by mean filtering method. The electrode electric parameter includes electrode voltage, electrode current, electrode active power and operating resistance.

[0024] The working condition recognition program is established according to the data in the original data set; in the specific implementation, as the preferred embodiment of the present application, the working condition recognition program recognizes the material collapse through the hearth pressure, most of the disturbance caused by the material collapse can be self-recovered, and when the material collapse occurs, the control output is inhibited; when the electrode is pressure dropped, the working condition recognition program inhibits the control output to avoid the overshoot caused by the adjustment action.

[0025] In the specific implementation, as the preferred embodiment of the present application, the working condition recognition program adopts the deburring program to eliminate abnormal disturbance, as shown in the formula (1), the disturbance value is replaced by the filtered value, which avoids the excessive response due to the disturbance while ensuring the control accuracy. Figure 2

[0026] Figure 2 F.IN represents the real-time sampling value of the object variable, F.OUT represents the variable output value after deburring, and F.LAST represents the last sampling value before the program judges that the deviation is out of limit.

[0027] The transfer function model is established based on the single-input single-output system of the electrode lifting; In the specific implementation, as the preferred embodiment of the present application, the transfer function model is described by using the controlled autoregressive integral moving average model, and the model to be identified is as follows:

[0028] Among them, represents the backward shift operator, represents the autoregressive polynomial, represents the input / control polynomial, represents the output of the system at time t, represents the control input of the system at time t, represents the pure time delay of the system, represents the random disturbance term, represents the backward difference operator. Taking the resistance mode as an example, the step response data is intercepted in the historical data set, the data is normalized, and the program is identified to obtain the following results:

[0029]

[0030] Among them, ​​​Indicates the electrode position output, Indicates the electrode position at the previous moment, Indicates the resistance input at the previous moment.

[0031] The continuous transfer function is expressed as:

[0032] The control mode of the electrode lifting of the ore arc furnace is designed according to different working conditions. When it is implemented, as a preferred embodiment of the present invention, the control mode is as follows: Figure 3 The diagrams include current mode, resistance mode, and active mode, where: The current mode is applied to working conditions where the current is limited under high load to prevent overburning and electrode edge contact, with the electrode current as the control input and feedback, and the electrode position as the control output. The current setting value needs to be set in advance before switching the current mode, and the control setting value also needs to be adjusted more when it is put into automatic use; the resistance mode is applied to working conditions where the load is frequently adjusted, with the operating resistance as the control input and feedback, and the electrode position as the control output, such as peak and valley electricity consumption or the load increase stage after shutdown, the control setting value is adjusted less frequently, and when switching the resistance mode, the program will preset the resistance setting value to ensure smooth switching; the active power mode is applied to working conditions where the load is stable, with the electrode active power as the control input and feedback, and the electrode position as the control output, such as working conditions for long-term stable load production, the control setting value is adjusted less frequently, and is mainly adjusted when adjusting the load and electrode bias.

[0033] The structure of the control loop is as follows Figure 4 As shown in the figure, the control input of the GPC generalized predictive control loop is selected based on the control mode. The control output is an electrode position command, which is then sent to the industrial control system to execute the electrode action. After the electrode action, a feedback value is obtained. The control feedback of all three modes is filtered and de-spiked.

[0034] The present invention also includes safety interlock settings, mainly including: limit alarm, when the electrode current, electrode voltage, and electrode active power exceed the limit range and remain for a period of time when the control is put into use, the alarm will jump out of the electrode automatically; electrode pressure point fault alarm, the electrode power factor and electrode voltage trend are used to judge whether the pressure point is loosely connected or broken, and the alarm jumps out automatically; communication fault alarm, the communication status between the advanced control program and the industrial control system is detected, and the alarm jumps out automatically; electrode position output limit interlock, which limits the program's output control of the electrode position within the set range; control input limit interlock, which limits the set value range of the control input.

[0035] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for APC advanced process control of the electrode position of an ore-bearing furnace, applied to the electrode equipment of an ore-bearing furnace, characterized in that: include: Collect the electrode position, electrode electrical parameters, furnace pressure and pressure-release data of the submerged arc furnace as the original data set; The data in the original data set are preprocessed by the mean filtering method; Establish a working condition identification procedure based on the data in the original data set; Establish a transfer function model based on a single-input single-output system with electrode lifting; Design the control mode of the electrode lifting of the submerged arc furnace according to different working conditions.

2. The APC advanced process control method for electrode position of an electric arc furnace according to claim 1, characterized in that: The working condition identification program identifies material collapse through furnace pressure, and when material collapse occurs, the control output is suppressed; when the electrode pressure is released, the working condition identification program suppresses the control output to avoid overshoot caused by the adjustment action.

3. The APC advanced process control method for electrode position of an electric arc furnace according to claim 2, characterized in that: The working condition identification program adopts a deburring program to eliminate abnormal disturbances, outputs deburring judgment through thresholds and delays, and replaces the disturbance value with a filtered value, thereby avoiding excessive response due to disturbances while ensuring control accuracy.

4. The APC advanced process control method for electrode position of an electric arc furnace according to claim 1, characterized in that: The transfer function model is described using a controlled autoregressive integrated moving average model, and the model to be identified is: in, represents the backshift operator, represents an autoregressive polynomial, represents the input / control polynomial, Indicates that the system is Output at any moment, Indicates that the system is The control input at the moment, represents the pure time delay of the system, represents the random disturbance term, represents the backward difference operator.

5. The APC advanced process control method for electrode position of an electric arc furnace according to claim 1, characterized in that: The control modes include current mode, resistance mode and active mode, wherein: The current mode is used to limit current under high load to prevent overburning and electrode edge conditions, with electrode current as the control input and feedback, and electrode position as the control output; the resistance mode is used for conditions where the load is frequently adjusted, with operating resistance as the control input and feedback, and electrode position as the control output; the active power mode is used for conditions where the load is stable, with electrode active power as the control input and feedback, and electrode position as the control output; The control input of the GPC generalized predictive control loop is selected according to the control mode, and the control output electrode position command is output to the industrial control system to execute the electrode action, and the feedback value is obtained after the electrode action.

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