A control method for the fire damper of a steelmaking converter

Abstract

This application relates to the field of metallurgical technology and discloses a control method for the fire door of a steelmaking converter. The method includes: the controller receives a door closing signal; the controller times the first motor and the second motor respectively; after reaching the preset time, the first fire door and the second fire door are closed in place, and the first motor and the second motor stop; if the running time of one of the motors reaches the preset time first, then control one of the motors to stop, and the running time of the other motor does not reach the preset time, the controller obtains the excitation current given value and the excitation current feedback of the frequency converter corresponding to the other motor, and controls the other motor to stop according to the excitation current given value and the excitation current feedback. In the case of no closing limit, this application can not only control the fire door to stop automatically and quickly when it is closed in place, but also close tightly, and prevent the frequency converter of the fire door from generating a large current, reducing the impact on the motor and the frequency converter, and reducing the equipment investment cost.

Description

Technical Field

[0001] This application relates to the field of metallurgical technologies, and in particular, to a method for controlling a fireproof door of a steelmaking converter. Background Art

[0002] The front fireproof door of a steelmaking converter is a front protection device for preventing molten steel from splashing and injuring people during the smelting of a steelmaking converter. When the fireproof door is opened, operations such as charging iron, cleaning the furnace mouth, and replacing the slide plate are carried out; when the fireproof door is closed, operations such as tilting the furnace and blowing can be carried out. The fireproof door is divided into two doors, namely Door 1 and Door 2. When the fireproof door is closed, Door 1 runs to the right and Door 2 runs to the left, and stops at the middle position of the converter. Due to the poor environment in front of and around the converter, installing a closing limit switch is likely to cause scalding and damage, while other ranging and drum limit switches are relatively costly, and relying on people to observe the in-place situation always fails to close tightly, or the closing is not timely, resulting in a large impact. Therefore, this method is designed to be able to automatically control the closing and stopping of the fireproof door and close it tightly. Summary of the Invention

[0003] The purpose of this application is to provide a method for controlling a fireproof door of a steelmaking converter, which can, in the absence of a closing limit switch, not only control the fireproof door to stop automatically and quickly when it closes in place, but also close tightly, and prevent the converter door frequency converter from generating a large current, reducing the impact on the motor and the frequency converter, and reducing the equipment investment cost.

[0004] Other features and advantages of this application will become apparent through the following detailed description, or be learned in part through the practice of this application.

[0005] According to one aspect of the embodiments of the present application, a control method for a fire door of a steelmaking converter is provided. The steelmaking converter includes a first motor for driving a first fire door, a second motor for driving a second fire door, a first frequency converter for controlling the operation of the first motor, a second frequency converter for controlling the operation of the second motor, and a controller for controlling the operation of the first frequency converter and the second frequency converter. The method includes: The controller receives a door closing signal and sends closing commands to the first frequency converter and the second frequency converter respectively according to the door closing signal; The first frequency converter controls the operation of the first motor according to the closing command, and the second frequency converter controls the operation of the second motor according to the closing command. The controller times the first motor and the second motor respectively; After reaching a preset time, the first fire door and the second fire door are closed in place. The controller controls the first motor to stop through the first frequency converter and controls the second motor to stop through the second frequency converter; If the running time of one of the motors reaches the preset time first, the controller controls the one motor to stop through the frequency converter corresponding to the one motor. The running time of the other motor does not reach the preset time. The controller obtains the excitation current given value and the excitation current feedback value of the frequency converter corresponding to the other motor, and controls the other motor to stop according to the excitation current given value and the excitation current feedback value.

[0006] In some embodiments, the steelmaking converter further includes a first door open limit and a second door open limit. Before the controller receives the door closing signal and sends closing commands to the first frequency converter and the second frequency converter respectively according to the door closing signal, the method further includes: The first fire door is at the first door open limit, and the second fire door is at the second door open limit.

[0007] In some embodiments, in the case where the running time of one of the motors reaches the preset time first, the controller controls the one motor to stop through the frequency converter corresponding to the one motor. The running time of the other motor does not reach the preset time. The controller obtains the excitation current given value and the excitation current feedback value of the frequency converter corresponding to the other motor, and controls the other motor to stop according to the excitation current given value and the excitation current feedback value, the method further includes: If the frequency converter corresponding to the first motor and / or the second motor cannot drive the faulty motor to work, or the first motor and / or the second motor is stopped manually, the controller pauses the timing of the first motor and / or the second motor; When the first motor and / or the second motor resumes operation, the controller continues to time the first motor and / or the second motor; After the running time of one of the motors reaches its corresponding preset time first, control the one motor that reaches the preset time first to stop running.

[0008] In some embodiments, after one of the motors reaches its corresponding preset time first and the controller controls the one motor that reaches the preset time first to stop running, the method further includes: the controller obtains the excitation current feedback and the excitation current setting of the frequency converter corresponding to the other motor that has not reached the preset time; the controller controls the fire damper corresponding to the other motor to stop running according to the excitation current feedback and the excitation current setting.

[0009] In some embodiments, in the process that the controller controls the fire damper corresponding to the other motor to stop running according to the excitation current feedback and the excitation current setting, the method further includes: obtaining the absolute value of the difference between the excitation current feedback and the excitation current setting; dividing the absolute value of the difference by the excitation current setting to obtain a target value; when the target value is greater than a first preset threshold, the controller controls the other motor and the fire damper corresponding to the other motor to stop running.

[0010] In some embodiments, the first preset threshold is 10%.

[0011] In some embodiments, the preset time is 11 seconds.

[0012] With the technical solution of the present application above, compared with the prior art, its remarkable beneficial effects are as follows: Since the environment in front of the converter and its surrounding areas is poor, installing closing limiters is likely to cause scalding and damage, and other devices such as ranging devices and reel limiters are relatively costly. Moreover, relying on people to observe the in-place situation always fails to close tightly, or the closing is not timely, resulting in a large impact, which damages the motor or the frequency converter. Therefore, without adding any form of closing limiters (ranging devices, reel limiters), by calculating and analyzing the running time of the fire damper in front of the furnace, the excitation current setting, the excitation current feedback, and the speed feedback, the fire damper can be closed tightly without generating a large current, reducing the impact on the motor or the frequency converter, reducing the equipment investment cost, and being able to automatically control the closing and stopping of the fire damper and close it tightly.

[0013] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] By referring to the accompanying drawings and describing its exemplary embodiments in detail, the above and other features and advantages of the present application will become more obvious.

[0015] Figure 1 The flowchart showing an embodiment of the present application is illustrated. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more complete and comprehensive, and will fully convey the concept of the example embodiments to those skilled in the art.

[0017] In addition, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of the embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, devices, steps, etc. may be employed. In other instances, well-known methods, devices, implementations, or operations are not shown or described in detail to avoid obscuring aspects of this application.

[0018] The block diagrams shown in the drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0019] The flowcharts shown in the drawings are merely illustrative and do not necessarily include all the content and operations / steps, nor do they necessarily have to be executed in the order described. For example, some operations / steps can be decomposed, while some operations / steps can be combined or partially combined, so the actual execution order may change according to the actual situation.

[0020] The implementation details of the technical solutions of the embodiments of this application are elaborated in detail below:

[0021] A first motor, a second motor, a first frequency converter, a second frequency converter, a first door open limit switch, a second door open limit switch, and a controller.

[0022] The first motor: drives the first fire door to operate.

[0023] The second motor: drives the second fire door to operate.

[0024] The first frequency converter: communicates with the PLC, receives the start, stop, and speed signals from the PLC, and drives the first motor to operate.

[0025] The second frequency converter: communicates with the PLC, receives the start, stop, and speed signals from the PLC, and drives the second motor to operate.

[0026] The first door open limit switch: is the limit for the first fire door to open in place, and transmits a digital high-level signal to the PLC.

[0027] Second door open limit: It is the limit for the second fire door to open in place, and transmits a digital high-level signal to the PLC.

[0028] PLC: Receives the excitation current setting, excitation current feedback, speed feedback (not the actual speed detected by the encoder, but the speed calculated inside the frequency converter) of the first frequency converter and the second frequency converter, the digital high-level signals of the first door open limit and the second door open limit, and transmits start, stop, and speed signals to the first frequency converter and the second frequency converter.

[0029] The PLC transmits start, stop, and speed signals to the first frequency converter and the second frequency converter through communication; the PLC transmits digital high-level signals to the first door open limit and the second door open limit through the hard wire of the I / O module.

[0030] When the fire door is in the open state, the first fire door is at the first door open limit, and the second fire door is at the second door open limit. The PLC transmits the same closing command and speed to the first frequency converter and the second frequency converter at the same time. At this time, the internal timers T1 and T2 of the PLC start timing for the first fire door and the second fire door respectively. If no faults occur or manual intervention is not performed during the operation of the first fire door and the second fire door, then T1 and T2 time out to 11s at the same time, and the first fire door and the second fire door stop at the same time.

[0031] To enable those skilled in the art to better understand the present application, the following will be combined with Figure 1 Briefly describe the present application.

[0032] According to some embodiments, the present application provides a control method for a fire door of a steelmaking converter. The steelmaking converter includes a first motor for driving a first fire door, a second motor for driving a second fire door, a first frequency converter for controlling the operation of the first motor, a second frequency converter for controlling the operation of the second motor, and a controller for controlling the operation of the first frequency converter and the second frequency converter. The method includes:

[0033] Step 101, the controller receives a closing signal and respectively sends a closing command to the first frequency converter and the second frequency converter according to the closing signal;

[0034] Step 102, the first frequency converter controls the operation of the first motor according to the closing command, the second frequency converter controls the operation of the second motor according to the closing command, and the controller respectively times the first motor and the second motor;

[0035] Step 103, after reaching a preset time, the first fire door and the second fire door close, and the controller controls the first motor to stop through the first frequency converter and controls the second motor to stop through the second frequency converter.

[0036] Step 104, if the running time of one of the motors reaches the preset time first, the controller controls the one motor to stop through the frequency converter corresponding to the one motor. When the running time of the other motor does not reach the preset time, the controller obtains the excitation current reference and excitation current feedback of the frequency converter corresponding to the other motor, and controls the other motor to stop according to the excitation current reference and excitation current feedback.

[0037] Based on the above embodiment, in step 101, when both the first fire door and the second fire door are in the open state and the controller receives a door closing signal, the controller simultaneously sends the same closing command to the first frequency converter and the second frequency converter according to the door closing signal.

[0038] In step 102, the first frequency converter controls the first motor to work according to the closing command, the first motor controls the first fire door to perform a closing action, the second frequency converter controls the second motor to work according to the closing command, the second motor controls the second fire door to perform a closing action. At the same time, the controller starts timing T1 and T2 for the first motor and the second motor respectively.

[0039] In step 103, after reaching the preset time, the first fire door and the second fire door just close. The controller controls the first motor to stop through the first frequency converter, and the first fire door also stops. The controller controls the second motor to stop through the second frequency converter, and the second fire door also stops. Among them, the preset time can be set according to actual needs, and the factors it depends on include running speed and running distance.

[0040] In step 104, if the running time of the first motor reaches the preset time first, the controller controls the first motor to stop through the first frequency converter. When the running time of the first motor reaches the preset time, the running time of the second motor has not reached the preset time yet. The controller obtains the excitation current reference and excitation current feedback of the second frequency converter, and the controller controls the second motor to stop according to the excitation current reference and excitation current feedback.

[0041] If the running time of the second motor reaches the preset time first, the controller controls the second motor to stop through the second frequency converter. When the running time of the second motor reaches the preset time, the running time of the first motor has not reached the preset time yet. The controller obtains the excitation current reference and excitation current feedback of the first frequency converter, and the controller controls the first motor to stop according to the excitation current reference and excitation current feedback. In some embodiments, the preset times of the first motor and the second motor are the same. The preset time can be set according to actual needs. In some embodiments, the preset time is 11 seconds.

[0042] Compared with traditional installation and closing limiters that are prone to scalding and damage, and other ranging and drum limiters that are relatively expensive, relying on human observation to ensure proper closing always fails to close tightly or results in untimely closing, causing large impacts and damaging the motor or frequency converter. Therefore, without adding any form of closing limiters (ranging devices, drum limiters), by controlling the running time of the front-of-furnace fire door, this application can not only automatically control the closing and stopping of the fire door but also ensure a tight closure.

[0043] In some embodiments, the controller adopts a PLC controller.

[0044] According to some embodiments, the steelmaking converter further includes a first door opening limit and a second door opening limit. In step 101, before the controller receives the door closing signal and sends closing commands to the first frequency converter and the second frequency converter respectively according to the door closing signal, the method further includes:

[0045] The first fire door is at the first door opening limit, and the second fire door is at the second door opening limit.

[0046] Based on the above embodiments, by setting the first door opening limit and the second door opening limit, when the first fire door and the second fire door are opened, the first fire door is stopped at the first door opening limit, and the second fire door is stopped at the second door opening limit, preventing the first fire door and the second fire door from rushing out of the door opening limit when opened or stopping before reaching the door opening limit.

[0047] According to some embodiments, in step 104, when the running time of one of the motors first reaches the preset time, the controller controls the one motor to stop through the frequency converter corresponding to the one motor, and when the running time of the other motor does not reach the preset time, the controller obtains the excitation current given and the excitation current feedback of the frequency converter corresponding to the other motor, and controls the other motor to stop according to the excitation current given and the excitation current feedback. The method further includes:

[0048] Step 1041, if the frequency converter corresponding to the first motor and / or the second motor cannot drive the faulty motor to work, or when the first motor and / or the second motor is manually controlled to stop, the controller pauses the timing of the first motor and / or the second motor;

[0049] Step 1042, when the first motor and / or the second motor resumes running, the controller continues to time the first motor and / or the second motor;

[0050] Step 1043, after one of the motors first reaches its corresponding preset time, control the one motor that first reaches the preset time to stop running.

[0051] Step 1044: The controller obtains the excitation current feedback and the excitation current set value of the frequency converter corresponding to another motor that has not reached the preset time.

[0052] Step 1045: The controller controls the fire damper corresponding to the other motor to stop running according to the excitation current feedback and the excitation current set value.

[0053] Based on the above embodiments, when the first motor and / or the second motor fails, the failure may be a stop, or the motor speed is not as fast as the normal operating speed due to other reasons. At this time, the controller pauses the timing of the faulty motor or the stopped motor. Because the speed is no longer the normal speed, if it runs according to the time corresponding to the normal speed, the two fire dampers will collide. Therefore, at this time, the controller separately times the running time of the first motor and the second motor. Among them, for the motor that reaches the preset time first, the controller sends a stop command to the frequency converter of the motor that reaches the preset time first, and the frequency converter controls the motor to stop; when the controller detects that either the running time of the first motor or the second motor reaches the preset time first, then the controller obtains the excitation current feedback and the excitation current set value of the frequency converter corresponding to the motor that has not reached the preset time. When the absolute value of the difference between the excitation current set value and the excitation current feedback, divided by the excitation current set value, is greater than the first preset threshold, the controller controls the fire damper corresponding to the motor that has not reached the preset time to stop running.

[0054] Further, for a motor without a fault or not stopped by manual control, the controller does not pause the timing, that is, continuous timing. The motor without a fault or not stopped by manual control can work normally and run normally until it is closed.

[0055] According to some embodiments, in step 104, when the controller controls the fire damper corresponding to the other motor to stop running according to the excitation current feedback and the excitation current set value, the method further includes:

[0056] Step 10451: Obtain the absolute value of the difference between the excitation current feedback and the excitation current set value.

[0057] Step 10452: Divide the absolute value of the difference by the excitation current set value to obtain a target value.

[0058] Step 10453: When the target value is greater than the first preset threshold, the controller controls the other motor and the fire damper corresponding to the other motor to stop running.

[0059] Based on the above embodiments, when the first fire door and the second fire door collide, the excitation current feedback will change. The controller continuously obtains the absolute value of the difference between the excitation current feedback and the given excitation current. When the absolute value of the difference divided by the target value of the given excitation current is greater than the first preset threshold, the controller controls the fire door corresponding to the motor that has not reached the preset time to stop running. That is, when the absolute value of (excitation current feedback - given excitation current) ÷ given excitation current is greater than the first preset threshold, the controller controls the fire door corresponding to the motor that has not reached the preset time to stop running. Among them, the first preset threshold can be set according to actual needs. In some embodiments, the first preset threshold is 10%.

[0060] After considering the specification and practicing the disclosed embodiments herein, those skilled in the art will readily conceive of other embodiments of the present application. The present application is intended to cover any variations, uses, or adaptations of the present application, which follow the general principles of the present application and include the common general knowledge or conventional technical means in the technical field not disclosed in the present application.

[0061] It should be understood that the present application is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present application is only limited by the appended claims.

Claims

1. A control method for a fire door of a steelmaking converter, characterized in that, the steelmaking converter includes a first motor for driving a first fire door, a second motor for driving a second fire door, a first frequency converter for controlling the operation of the first motor, a second frequency converter for controlling the operation of the second motor, and a controller for controlling the operation of the first frequency converter and the second frequency converter, and the method includes: The controller receives a door closing signal and respectively sends closing commands to the first frequency converter and the second frequency converter according to the door closing signal; The first frequency converter controls the operation of the first motor according to the closing command, the second frequency converter controls the operation of the second motor according to the closing command, and the controller times the first motor and the second motor respectively; After reaching the preset time, the first fire door and the second fire door are closed in place, and the controller controls the first motor to stop through the first frequency converter and controls the second motor to stop through the second frequency converter; If the running time of one of the motors reaches the preset time first, the controller controls the one motor to stop through the frequency converter corresponding to the one motor, and the running time of the other motor does not reach the preset time. The controller obtains the excitation current given value and the excitation current feedback of the frequency converter corresponding to the other motor, and controls the other motor to stop according to the excitation current given value and the excitation current feedback.

2. The method according to claim 1, characterized in that, the steelmaking converter further includes a first door open limit and a second door open limit. Before the controller receives the door closing signal and respectively sends closing commands to the first frequency converter and the second frequency converter, the method further includes: The first fire door is at the first door open limit, and the second fire door is at the second door open limit.

3. The method according to claim 1, characterized in that, in the case where the running time of one of the motors reaches the preset time first, the controller controls the one motor to stop through the frequency converter corresponding to the one motor, and the running time of the other motor does not reach the preset time. The controller obtains the excitation current given value and the excitation current feedback of the frequency converter corresponding to the other motor, and controls the other motor to stop according to the excitation current given value and the excitation current feedback, the method further includes: If the frequency converter corresponding to the first motor or / and the second motor cannot drive the faulty motor to work, or when the first motor is manually controlled to stop and / or the second motor is manually controlled to stop, the controller pauses the timing of the first motor or / and the second motor; When the first motor and / or the second motor resumes operation, the controller continues to time the first motor or / and the second motor; After one of the motors reaches its corresponding preset time first, control the one motor that reaches the preset time first to stop running.

4. The method according to claim 3, characterized in that, after controlling the one motor that reaches the preset time first to stop running after one of the motors reaches its corresponding preset time first, the method further includes: The controller obtains the excitation current feedback and the excitation current set value of the frequency converter corresponding to another motor that has not reached the preset time; The controller controls the fire damper corresponding to the another motor to stop running according to the excitation current feedback and the excitation current set value.

5. The method according to claim 1, wherein, in the controller controlling the fire damper corresponding to the another motor to stop running according to the excitation current feedback and the excitation current set value, the method further includes: obtaining the absolute value of the difference between the excitation current feedback and the excitation current set value; dividing the absolute value of the difference by the excitation current set value to obtain a target value; when the target value is greater than a first preset threshold, the controller controls the another motor and the fire damper corresponding to the another motor to stop running.

6. The method according to claim 5, wherein, the first preset threshold is 10%.

7. The method according to claim 1, wherein, the preset time is 11 seconds.

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