Converter oxygen regulating valve control method for dry dust removal

Abstract

This invention discloses a control method for an oxygen regulating valve in a converter for dry dust removal, including automatic blowing, detecting the open / closed state of the main pipe shut-off valve, starting blowing, adaptive parameter setting, oxygen lance positioning, preset regulating valve opening, setting oxygen flow rate, detecting the stable pressure value after the valve, entering dual closed-loop control, setting the initial oxygen flow rate purging time, controlling the ramp flow time, automatically controlling the oxygen lance position and oxygen flow rate based on oxygen step table data, and calculating the cumulative oxygen blowing volume to close the regulating valve when the set value is reached. This invention, targeting the control method of an oxygen regulating valve in a converter for dry dust removal, uses a PLC and regulating valve as the hardware platform. It fully considers the range of oxygen supply pressure in the pipeline network and the requirements of the dry dust removal process. By improving the control method of the oxygen regulating valve in the early stage of blowing, it improves the stability of the oxygen flow rate in the early stage of converter blowing and reduces the problem of large fluctuations in oxygen flow rate in the early stage of blowing, thus meeting the process requirements of dry dust removal.

Description

Technical Field

[0001] This invention relates to the field of oxygen regulation technology for steelmaking converters, specifically a method for controlling oxygen regulating valves in converters for dry dust removal. Background Technology

[0002] Based on energy conservation and environmental protection requirements, the converter's dust removal system adopts dry dust removal. In the early stages of blowing, the dry dust removal system must use a low oxygen flow rate to control the rapid increase in CO gas in the flue gas and prevent explosion accidents in the dust removal system. Currently, the regulating valve control method uses a fixed flow rate during the start-up phase. Considering the fluctuations in pipeline pressure, using a fixed flow rate during the start-up phase carries the risk of flow fluctuations, which cannot meet the process requirements of dry dust removal. In severe cases, it can interrupt the steelmaking process and affect product quality. Summary of the Invention

[0003] The purpose of this invention is to provide a converter oxygen regulating valve control method for dry dust removal. By improving the control method of the oxygen regulating valve in the early stage of blowing, the stability of oxygen flow reaching the target value is improved, so as to meet the requirements of dry dust removal process and solve the shortcomings of the prior art.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A method for controlling an oxygen regulating valve in a converter for dry dust removal includes the following steps:

[0006] S1: Start Automatic Mode: The operator selects the "Automatic Blowing" mode in the dry dust removal system, and the system initializes and prepares to execute subsequent control logic;

[0007] S2: Main pipe shut-off valve status detection: The system detects whether the main pipe shut-off valve has been fully opened;

[0008] S3: Start the blowing process: The operator clicks the "Start Blowing Process" button, and the system enters the blowing preparation stage;

[0009] S4: Adaptive parameter setting: The system monitors the main pipe pressure in real time. It automatically selects the initial opening degree of the pressure regulating valve according to preset rules. And PID control parameters to optimize subsequent dynamic response;

[0010] S5: Oxygen Lance Positioning: The system controls the oxygen lance to automatically descend to the preset oxygen blowing point. It confirms whether it has arrived via feedback from the position sensor; if it has not arrived, it enters a fault handling waiting state.

[0011] S6: Preset opening of regulating valve: Adjust the pressure regulating valve to a preset fixed opening. At the same time, adjust the flow regulating valve to the preset fixed opening degree. ;

[0012] S7: When the flow rate reaches the ignition flow rate Maintain the current opening and continue blowing for 8 seconds;

[0013] S8: Stabilized downstream pressure: Detects downstream pressure Has the set value been reached? The stability condition is:

[0014] in, To allow for error, if the target is not reached, fine-tune or wait until the pressure stabilizes.

[0015] S9: Enter Dual Closed-Loop Control: Once the oxygen lance is in position and the downstream pressure stabilizes, switch the pressure regulating valve and flow regulating valve to dual closed-loop control mode. The pressure closed-loop control will then control the downstream pressure. Closed-loop control of oxygen flow ;

[0016] S10: Initial Flow Purge: Set the initial purge flow rate to... The duration is A constant flow rate is used for purging to remove residual gas from the pipeline and stabilize the system;

[0017] S11: Slope Upflow: in time Internally, the flow will be transferred from Linearly increase to the preset blowing flow rate setting value The slope of the ramp is adjustable;

[0018] S12: Automatic execution of oxygen step table: Automatically controls the position of oxygen lance and oxygen flow rate according to the preset oxygen step table to achieve process requirements;

[0019] S13: Cumulative Oxygen Blowing Calculation: Real-time calculation of cumulative oxygen blowing volume and the target set value Compare the results to determine if the set value has been reached;

[0020] S14: Regulating valve closed: Close the pressure regulating valve and flow regulating valve to end the blowing process, and the system enters standby or the next cycle.

[0021] Furthermore, in S2, the state variable of the main shut-off valve is defined as follows: ,like If the valve is fully open, continue; if... If the fault is not resolved, the process will proceed to the fault handling waiting stage until the fault is eliminated.

[0022] Furthermore, the PID control parameters in S3 include the proportional coefficient. Integral Time Differential time .

[0023] Furthermore, the flow changes in S11 follow the following:

[0024]

[0025] in, The initial purge flow rate value. The preset blowing flow rate value, For the set time value, This is the actual time value.

[0026] Furthermore, the oxygen brute-force parameters in S12 can be adjusted online, and it includes multiple stages, each with a target oxygen lance height. and target traffic .

[0027] Furthermore, the cumulative oxygen blowing volume in S13 The calculation formula is as follows:

[0028]

[0029] like Then continue executing the oxygen schedule; if Then proceed to the next step.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] The present invention provides a converter oxygen regulating valve control method for dry dust removal. Using PLC and regulating valve as hardware platforms, it fully considers the range of oxygen supply pressure in the pipeline network and the requirements of dry dust removal process. By improving the control method of oxygen regulating valve in the early stage of blowing, it improves the stability of oxygen flow in the early stage of converter blowing and reduces the problem of large fluctuations in oxygen flow in the early stage of blowing, so as to meet the process requirements of dry dust removal. Attached Figure Description

[0032] Figure 1 This is a logic flowchart of the control method according to an embodiment of the present invention. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] This invention, using a PLC and regulating valve as the hardware platform, fully considers the range of oxygen supply pressure in the pipeline network and the requirements of dry dust removal processes. It provides a method for controlling the oxygen regulating valve in a converter for dry dust removal, aiming to reduce the problem of large fluctuations in oxygen flow rate during the early stages of blowing. Figure 1 As shown, the present invention mainly includes the following steps:

[0035] S1: Based on the existing converter dry dust removal system, start the automatic mode: The operator selects the "automatic blowing" mode, the system initializes and prepares to execute subsequent control logic:

[0036] S2: Main pipe shut-off valve status detection: The system detects whether the main pipe shut-off valve has been fully opened. The status variable is defined as follows: ,like If the valve is fully open, continue; if... If the fault is not resolved, the process will proceed to the fault handling waiting stage until the fault is resolved.

[0037] S3: Start the blowing process: The operator clicks the "Start Blowing Process" button, and the system enters the blowing preparation stage;

[0038] S4: Adaptive parameter setting: The system monitors the main pipe pressure in real time. It automatically selects the initial opening degree of the pressure regulating valve according to preset rules. And PID control parameters (proportional coefficient) Integral Time Differential time ), to optimize subsequent dynamic response;

[0039] S5: Oxygen Lance Positioning: Controls the oxygen lance to automatically descend to the preset oxygen blowing point. (Unit: m), and confirm arrival via position sensor feedback. If arrival is not achieved, the system enters a fault handling waiting state.

[0040] S6: Preset opening of regulating valve: Adjust the pressure regulating valve to a preset fixed opening. At the same time, adjust the flow regulating valve to the preset fixed opening degree. ;

[0041] S7: When the flow rate reaches the ignition flow rate (Unit: Nm³ / h), maintain the current blowing speed for 8 seconds;

[0042] S8: Stabilized downstream pressure: Detects downstream pressure (Unit: Pa) Has the set value been reached? The stability condition is:

[0043]

[0044] in, This allows for acceptable error. If the target is not reached, fine-tune the process or wait until the pressure stabilizes.

[0045] S9: Enter Dual Closed-Loop Control: Once the oxygen lance is in position and the downstream pressure stabilizes, switch the pressure regulating valve and flow regulating valve to dual closed-loop control mode. Pressure closed-loop control of downstream pressure... Closed-loop control of oxygen flow ;

[0046] S10: Initial Flow Purge: Set the initial purge flow rate to... The duration is A constant flow purging process is performed to remove residual gas from the pipeline and stabilize the system.

[0047] S11: Slope Upflow: in time Internally, the flow will be transferred from Linearly increase to the preset blowing flow rate setting value The ramp slope is adjustable. Flow rate changes follow:

[0048]

[0049] in, The initial purge flow rate value. The preset blowing flow rate value, For the set time value, This is the actual time value.

[0050] S12: Automatic execution of the oxygen step table: Based on the preset oxygen step table (containing multiple stages, each stage has a target oxygen gun height). and target traffic It automatically controls the position of the oxygen lance and the oxygen flow rate to meet process requirements. The parameters of the oxygen step table can be adjusted online.

[0051] S13: Cumulative Oxygen Blowing Calculation: Real-time calculation of cumulative oxygen (or nitrogen) blowing volume:

[0052]

[0053] and the target set value (Unit: Nm³) Compare to determine if the set value has been reached: If Then continue executing the oxygen schedule; if Then proceed to the next step.

[0054] S14: Regulating valve closed: Close the pressure regulating valve and flow regulating valve to end the blowing process. The system can then enter standby or the next cycle.

[0055] To further illustrate the feasibility of the above methods, the following specific implementation examples are provided:

[0056] Taking a special steel converter at Maanshan Iron & Steel Group as an example during the initial heat load stage: In the early ignition phase of blowing, a fixed valve opening is used. Due to unstable pressure in the main oxygen pipe, insufficient oxygen supply leads to incomplete initial combustion when the pressure is below 2.0 MPa. This results in a slow carbon-oxygen reaction in the initial stage, preventing timely oxidation of carbon into CO gas. As blowing continues, unreacted carbon may react rapidly with oxygen in the later stages, leading to an overly vigorous reaction and the accumulation of large amounts of CO gas at the furnace mouth. This poses a risk of dust collector explosion, resulting in a series of production hazards and economic losses.

[0057] To address the aforementioned problems, this embodiment provides a converter oxygen regulating valve control method for dry dust removal, the specific implementation of which is as follows:

[0058] 1. Based on the main pipe pressure range of 1.6-2.2 MPa, it is divided into three ranges: 1.6-1.9 MPa, 1.9-2.1 MPa, and greater than 2.1 MPa. The oxygen main pipe is equipped with a pressure regulating valve, and the branch pipes are equipped with flow regulating valves. Before starting the purging process, the two regulating valves are set to a fixed opening K corresponding to the three different main pipe pressure ranges. P1 and K Q1 K P2 and K Q2 K P3 and K Q3 (This value is obtained from testing) to ensure that the oxygen flow rate for ignition is reached and the oxygen pressure at the oxygen gun nozzle is met within a short time after the start of blowing.

[0059] 2. Under the conditions of satisfying both ignition requirements and preventing explosions in the dry dust removal system, the oxygen flow rate for ignition, based on the process requirements, shall not be less than... (Unit: Nm³ / h), in this embodiment =22000 Nm³ / h. After starting the blowing process, once the oxygen lance reaches the blowing point, adjust the pressure regulating valve to the preset fixed opening. At the same time, adjust the flow regulating valve to the preset fixed opening degree. Once the pressure after the valve stabilizes and the oxygen flow rate reaches [a certain level], ;

[0060] 3. After blowing for 8 seconds, check the pressure after the valve. Reaching the set value , At this point, the flow regulating valve enters closed-loop control;

[0061] 4. After blowing for 30 seconds, the pressure regulating valve enters closed-loop control, and the flow rate remains at [a certain level]. After 60 seconds of continuous purging, the flow rate reaches the set flow rate after 30 seconds based on the adjustable ramp. The ramp slope is adjustable, and the flow rate changes according to:

[0062]

[0063] 5. Subsequently, the oxygen flow rate is adjusted under dual closed-loop regulation control according to the set value of the oxygen step meter.

[0064] 6. Cumulative Oxygen Blowing Calculation: Real-time calculation of cumulative oxygen (or nitrogen) blowing volume:

[0065]

[0066] and the target set value (Unit: Nm³) Compare to determine if the set value has been reached: If Then continue executing the oxygen schedule; if The refining process is complete;

[0067] By adopting the above control method, the oxygen flow rate is not less than 22,000 Nm³ / h after the oxygen lance reaches the oxygen-opening point, which not only ensures the ignition flow rate value, but also avoids the risk of explosion leakage, thus meeting production needs.

[0068] In summary, the present invention provides a converter oxygen regulating valve control method for dry dust removal. By improving the control method of the regulating valve, the stability of oxygen flow in the early stage of converter blowing is improved, which meets the process requirements of dry dust removal. It has been successfully applied in steelmaking production. After a period of data recording and analysis, the control method is stable and reliable and fully meets production needs.

[0069] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for controlling a converter oxygen regulating valve for dry dust removal, characterized in that, Includes the following steps: S1: Start Automatic Mode: The operator selects "Automatic Blowing" mode in the dry dust removal system, the system initializes and prepares to execute subsequent control logic; S2: Main pipe shut-off valve status detection: The system detects whether the main pipe shut-off valve has been fully opened; S3: Start the blowing process: The operator clicks the "Start Blowing Process" button, and the system enters the blowing preparation stage; S4: Adaptive parameter setting: The system monitors the main pipe pressure in real time. It automatically selects the initial opening degree of the pressure regulating valve according to preset rules. And PID control parameters to optimize subsequent dynamic response; S5: Oxygen Lance Positioning: The system controls the oxygen lance to automatically descend to the preset oxygen blowing point. It confirms whether it has arrived via feedback from the position sensor; if it has not arrived, it enters a fault handling waiting state. S6: Preset opening of regulating valve: Adjust the pressure regulating valve to a preset fixed opening. At the same time, adjust the flow regulating valve to the preset fixed opening degree. ; S7: When the flow rate reaches the ignition flow rate Maintain the current opening and continue blowing for 8 seconds; S8: Stabilized downstream pressure: Detects downstream pressure Has the set value been reached? The stability condition is: in, To allow for error, if the target is not reached, fine-tune or wait until the pressure stabilizes. S9: Enter Dual Closed-Loop Control: Once the oxygen lance is in position and the downstream pressure stabilizes, switch the pressure regulating valve and flow regulating valve to dual closed-loop control mode. The pressure closed-loop control will then control the downstream pressure. Closed-loop control of oxygen flow ; S10: Initial Flow Purge: Set the initial purge flow rate to... The duration is A constant flow rate is used for purging to remove residual gas from the pipeline and stabilize the system; S11: Slope Upflow: in time Internally, the flow will be transferred from Linearly increase to the preset blowing flow rate setting value The slope of the ramp is adjustable; S12: Automatic execution of oxygen step table: Automatically controls the position of oxygen lance and oxygen flow rate according to the preset oxygen step table to achieve process requirements; S13: Cumulative Oxygen Blowing Calculation: Real-time calculation of cumulative oxygen blowing volume and the target set value Compare the results to determine if the set value has been reached; S14: Regulating valve closed: Close the pressure regulating valve and flow regulating valve to end the blowing process, and the system enters standby or the next cycle.

2. The converter oxygen regulating valve control method for dry dust removal as described in claim 1, characterized in that: In S2, the state variable of the main shut-off valve is defined as follows: ,like If the valve is fully open, continue; if... If the fault is not resolved, the process will proceed to the fault handling waiting stage until the fault is eliminated.

3. The converter oxygen regulating valve control method for dry dust removal as described in claim 1, characterized in that: The PID control parameters in S3 include the proportional coefficient. Integral Time Differential time .

4. The converter oxygen regulating valve control method for dry dust removal as described in claim 1, characterized in that: The flow rate changes in S11 follow the following: in, The initial purge flow rate value. The preset blowing flow rate value, For the set time value, This is the actual time value.

5. The method for controlling a converter oxygen regulating valve for dry dust removal as described in claim 1, characterized in that: The oxygen lance parameters in S12 can be adjusted online. It includes multiple stages, each with a target oxygen lance height. and target traffic .

6. The converter oxygen regulating valve control method for dry dust removal as described in claim 1, characterized in that: Cumulative oxygen blowing volume in S13 The calculation formula is as follows: like Then continue executing the oxygen schedule; if Then proceed to the next step.

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