A blast furnace pulverized coal injection real-time injection rate deviation control system, method and application

Abstract

The present application belongs to the technical field of steelmaking equipment, and discloses a blast furnace pulverized coal injection real-time injection rate deviation control system, method and application. The system comprises a PLC system, a PID controller, an injection rate detector and an injection system. The PLC system, the PID controller, the injection rate detector and an executor are connected. The PLC system comprises a real-time monitoring module, a cumulative deviation calculation module and a feedback parameter selection module. By real-time monitoring of the injection rate and dynamic switching of the feedback parameters (hourly cumulative deviation and real-time deviation), the system response time is significantly shortened, and the overshoot phenomenon caused by hysteresis is effectively reduced. Combined with the adaptive PID controller, the proportional, integral and differential coefficients can be automatically adjusted according to the deviation size, the real-time fluctuation is suppressed while the cumulative error is eliminated, the oscillation adjustment of the coal flow valve is greatly reduced, and the stability and continuity of the injection rate are ensured.

Description

Technical Field

[0001] This invention belongs to the technical field of steelmaking equipment, and in particular relates to a real-time pulverized coal injection rate deviation control system, method and application for blast furnace pulverized coal injection. Background Technology

[0002] In blast furnace pulverized coal injection systems, current technology primarily uses hourly cumulative deviation for PID control of the coal flow valve to control the injection rate. This control process is simplistic and suffers from severe overshoot. Specifically, the hourly cumulative injection deviation is used as a control variable. This variable is incremented by 0.25, and the result divided by 0.005 is used as the feedback value for PID control. The setpoint for PID control is fixed at 50. Simply put, when the hourly cumulative injection deviation is +0.1t, (0.1 + 0.25) / 0.005 = 70. This means that when the hourly cumulative injection deviation is +0.1t, the coal flow valve opening needs to be increased to reduce the cumulative deviation. Conversely, when the deviation is less than 0.1t, the opening needs to be decreased to reduce the cumulative deviation. The goal is to ensure that the injected coal quantity equals the setpoint within each cumulative natural hour. The current situation with this control method is as follows: when external disturbances (such as nitrogen pressure fluctuations) cause an increase in the hourly cumulative deviation, the hourly cumulative deviation has a certain lag. For example, when the valve gradually increases to 70% opening, the hourly cumulative injection deviation decreases to 0, and the coal flow valve will maintain its current opening. After a period of time, when a negative deviation appears, the valve opening will gradually decrease again. During the adjustment process, the coal flow valve will experience prolonged oscillating adjustments of increasing / decreasing its opening. The real-time injection rate deviates from the rate set by the blast furnace foreman by more than 2 t / h, and the hourly cumulative injection deviation exceeds 0.5 t. This adversely affects blast furnace production and is detrimental to the real-time stable injection requirements of blast furnace production.

[0003] The integral characteristic of the hourly cumulative deviation causes a significant lag in system response. For example, when an external disturbance (such as a sudden drop in nitrogen pressure) causes a decrease in the instantaneous injection rate, the system must wait for the deviation to accumulate to a certain threshold before triggering the adjustment action. During this period, the actual injection rate may have deviated significantly from the set value, and the delay in the adjustment command further exacerbates the overshoot phenomenon. After the coal flow valve's opening is adjusted, it often cannot be corrected in time due to the lag in the reduction of the deviation, causing the valve to oscillate repeatedly between "over-opening" and "over-closing," severely affecting control stability.

[0004] Existing methods rely solely on hourly cumulative deviation as the control variable, neglecting the dynamic fluctuations in real-time injection rate. For example, Chinese patent CN105368996A, entitled "An Automatic Control Method for Pulverized Coal Injection in a Blast Furnace System," primarily relies on segmented adjustment based on historical data and a combination of fuzzy PID control. It fails to dynamically introduce real-time injection rate deviation as an independent control variable into the adjustment process, resulting in lag in response to external disturbances (such as nitrogen pressure fluctuations), significant overshoot, and an inability to effectively suppress real-time deviation.

[0005] Therefore, existing blast furnace pulverized coal injection control technologies, due to issues such as lag, single control dimension, and fixed parameters, are unable to meet the stringent requirements of blast furnace production for real-time injection rate, stability, and anti-interference capability. There is an urgent need for a novel control method that can dynamically integrate real-time rate and cumulative deviation, adaptively adjust control parameters, and achieve smooth transitions. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a real-time injection rate deviation control system, method and application for blast furnace pulverized coal injection.

[0007] The technical solution adopted by this invention to solve its technical problem is:

[0008] A real-time injection rate deviation control system for pulverized coal injection in blast furnaces includes a PLC system, a PID controller, an injection rate detector, and an injection system. The PLC system, PID controller, injection rate detector, and actuator are all connected and configured. The PLC system includes a real-time monitoring module, a cumulative deviation calculation module, and a feedback parameter selection module.

[0009] The real-time monitoring module can collect injection rate data and calculate the real-time deviation value. The cumulative deviation calculation module can calculate the hourly cumulative injection deviation and its absolute value. The feedback parameter selection module can select the hourly cumulative deviation or the processed real-time deviation value as the PID input based on the absolute value threshold (0.1t). The PID controller can output the coal flow valve opening adjustment command based on the selected feedback parameter. The injection system can adjust the injection according to the output of the PID controller.

[0010] The method for controlling the real-time injection rate deviation of pulverized coal injection in a blast furnace as described above is characterized by the following steps:

[0011] (1) Monitor the blowing rate in real time and calculate the deviation between the real-time blowing rate and the set rate;

[0012] (2) Calculate the hourly cumulative injection deviation and take the absolute value;

[0013] (3) When the absolute value of the hourly cumulative injection deviation is ≥0.1 tons, the hourly cumulative injection deviation is used as the feedback parameter of PID control to adjust the opening of the coal flow valve.

[0014] (4) When the absolute value of the cumulative hourly injection deviation is less than 0.1 tons, the processed real-time injection rate deviation value is used as the feedback parameter of PID control to adjust the opening of the coal flow valve.

[0015] Further, in step (1), the weight data of the spray can is collected every second and stored in an array variable, the difference between adjacent seconds is calculated and stored in a second array variable; the average difference is calculated every 5 seconds as the instantaneous spray rate of the initial spraying stage.

[0016] Furthermore, in step (2), the method for calculating the hourly cumulative injection deviation is as follows:

[0017]

[0018] The formula for calculating the output value of the feedback parameters of the PID controller is as follows:

[0019]

[0020] u(t) is the output value of the PID controller, K P K is the proportional gain coefficient. i Let K be the integral gain coefficient, e(t) be the error value at the current time, τ be the initial time, and K be the error value at the beginning of the time. d This is the differential gain coefficient.

[0021] Furthermore, the optimization logic in steps (3) and (4) of the PID control parameters is as follows:

[0022] When the absolute value of the cumulative deviation is ≥0.1 tons, increase the proportional coefficient and integral coefficient to quickly eliminate the cumulative error;

[0023] When the absolute value of the cumulative deviation is less than 0.1 tons, the proportional coefficient is reduced and the differential coefficient is increased to suppress real-time rate fluctuations.

[0024] Furthermore, in steps (3) and (4), a gradual variable transition strategy is adopted when the feedback parameter is switched.

[0025] During the transition period T (T = 5 to 20 seconds), the weight of the previous feedback parameter is linearly reduced from 100% to 0%, and the weight of the new feedback parameter is linearly increased from 0% to 100%. During the transition period, the PID output value is the weighted sum of the old and new feedback parameters, where the weighting value is set by the staff based on experience.

[0026] Furthermore, the real-time jetting rate deviation value processed in step (4) is smoothed using a first-order low-pass filter. The filtering formula is as follows:

[0027] y n =αx n +(1-α)y n-1

[0028] Where α = 0.1 - 0.3, x n y represents the current real-time deviation value. n This is the filtered output value.

[0029] Application of any of the above in real-time injection rate deviation control of pulverized coal injection in blast furnace.

[0030] The advantages and positive effects of this invention are as follows:

[0031] 1. This invention significantly shortens the system response time and effectively reduces overshoot caused by lag by real-time monitoring of the injection rate and dynamically switching feedback parameters (hourly cumulative deviation and real-time deviation). Combined with an adaptive PID controller, it can automatically adjust the proportional, integral, and derivative coefficients according to the magnitude of the deviation, eliminating accumulated errors while suppressing real-time fluctuations, greatly reducing the oscillation adjustment of the coal flow valve, and ensuring the stability and continuity of the injection rate.

[0032] 2. A first-order low-pass filter (α = 0.1–0.3) is introduced to smooth the real-time deviation value, effectively filtering out noise interference and avoiding malfunctions. When the absolute value of the hourly cumulative deviation is ≥ 0.1 tons, the cumulative error is quickly eliminated by increasing the proportional and integral coefficients; when the deviation is small, the derivative action is enhanced to suppress small fluctuations and achieve precise control. A gradual variable transition strategy (T = 5–20 seconds) is adopted, and a smooth transition between old and new parameters is achieved through linear adjustment of weights when switching feedback parameters, avoiding abrupt changes in the coal flow valve opening command and further ensuring the stability of system operation.

[0033] 3. Through a closed-loop control architecture (real-time monitoring → calculation → adaptive adjustment → execution feedback) and dynamic parameter optimization logic, the system reduces the need for manual intervention, enhances its adaptability, and can adapt to complex operating conditions such as nitrogen pressure fluctuations, meeting the stringent requirements of blast furnace production for real-time stable injection. In practical applications, the real-time injection rate deviation can be controlled within 2t / h, and the hourly cumulative injection deviation is reduced to below 0.5t, effectively improving the utilization rate of blast furnace pulverized coal, reducing energy consumption, and ensuring the long-term stable and efficient operation of the blast furnace. Attached Figure Description

[0034] Figure 1 This is a system control flowchart of the present invention;

[0035] Figure 2 This invention relates to the real-time injection rate deviation processing procedure and control variable selection logic.

[0036] Figure 3 The logic diagram for the variables participating in PID control in this invention;

[0037] Figure 4 This is a historical trend chart of the injection rate before the implementation of this invention;

[0038] Figure 5 This is a historical trend chart of the injection rate after the implementation of this invention. Detailed Implementation

[0039] The present invention will be further described in detail below with reference to specific embodiments. The following embodiments are merely descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0040] Unless otherwise specified, all raw materials used in this invention are commercially available products. Unless otherwise specified, all methods used in this invention are conventional methods in the field. All substances used in this invention are of conventional mass. Structures, connections, etc., not described in detail in this invention can be understood as conventional techniques in the field.

[0041] A real-time injection rate deviation control system for pulverized coal injection in blast furnaces, such as Figure 1 As shown, it includes: a PLC system, a PID controller, a jetting rate detector, and a jetting system. The PLC system, PID controller, jetting rate detector, and actuator are all connected and configured. The PLC system includes a real-time monitoring module, a cumulative deviation calculation module, and a feedback parameter selection module.

[0042] The real-time monitoring module can collect injection rate data and calculate the real-time deviation value. The cumulative deviation calculation module can calculate the hourly cumulative injection deviation and its absolute value. The feedback parameter selection module can select the hourly cumulative deviation or the processed real-time deviation value as the PID input based on the absolute value threshold (0.1t). The PID controller can output the coal flow valve opening adjustment command based on the selected feedback parameter. The injection system can adjust the injection according to the output of the PID controller.

[0043] The above-mentioned system employs a real-time injection rate deviation control method for pulverized coal injection in blast furnaces, such as... Figures 2 to 3 As shown, the steps include:

[0044] (1) Monitor the blowing rate in real time and calculate the deviation between the real-time blowing rate and the set rate;

[0045] (2) Calculate the hourly cumulative injection deviation and take the absolute value;

[0046] (3) When the absolute value of the hourly cumulative injection deviation is ≥0.1 tons, the hourly cumulative injection deviation is used as the feedback parameter of PID control to adjust the opening of the coal flow valve.

[0047] (4) When the absolute value of the cumulative hourly injection deviation is less than 0.1 tons, the processed real-time injection rate deviation value is used as the feedback parameter of PID control to adjust the opening of the coal flow valve.

[0048] In this embodiment, in step (1), the weight data of the spray can is collected every second and stored in an array variable, the difference between adjacent seconds is calculated and stored in a second array variable, and the average difference is calculated every 5 seconds as the instantaneous spray rate of the initial spraying stage.

[0049] In this embodiment, the method for calculating the hourly cumulative spraying deviation in step (2) is as follows:

[0050]

[0051] In this embodiment, the feedback parameter of the PID controller is used to calculate the output value, and the formula is as follows:

[0052]

[0053] u(t) is the output value of the PID controller, K P K is the proportional gain coefficient. i Let K be the integral gain coefficient, e(t) be the error value at the current time, τ be the initial time, and K be the error value at the beginning of the time. d This is the differential gain coefficient.

[0054] In this embodiment, the optimization logic in the parameter steps (3) and (4) of the PID control includes:

[0055] When the absolute value of the cumulative deviation is ≥0.1 tons, increase the proportional coefficient and integral coefficient to quickly eliminate the cumulative error;

[0056] When the absolute value of the cumulative deviation is less than 0.1 tons, the proportional coefficient is reduced and the differential coefficient is increased to suppress real-time rate fluctuations.

[0057] In this embodiment, in steps (3) and (4), when the feedback parameter is switched, a gradual variable transition strategy is adopted, specifically as follows:

[0058] During the transition period T (T = 5 to 20 seconds), the weight of the previous feedback parameter is linearly reduced from 100% to 0%, and the weight of the new feedback parameter is linearly increased from 0% to 100%. During the transition period, the PID output value is the weighted sum of the old and new feedback parameters to avoid sudden changes in the opening of the coal flow valve. The weighted values ​​are set by the staff based on experience.

[0059] In this embodiment, the real-time jetting rate deviation value processed in step (4) is smoothed using a first-order low-pass filter. The filtering formula is as follows:

[0060] y n =αx n +(1-α)y n-1

[0061] Where α = 0.1 - 0.3, x n y represents the current real-time deviation value. n This is the filtered output value.

[0062] Application of any of the above in real-time injection rate deviation control of pulverized coal injection in blast furnace.

[0063] Specifically, the present invention is as follows:

[0064] like Figure 5 As shown, the PID controller is connected to the PLC system. In the initial stage of the injection, the weight data of the injection tank is collected every second and stored in an array variable. The difference between adjacent seconds is calculated and stored in a second array variable. The average difference is calculated every 5 seconds as the instantaneous injection rate in the initial injection stage. The cumulative hourly spraying deviation is calculated using the formula (set rate - actual spraying rate)Δt; the output value is calculated using the feedback parameters of the PID controller, with the following formula: Where the initial parameter is K P =1.5, K i =0.05, K d =0.2. The opening of the coal flow valve is adjusted according to the output value, and a closed-loop control is formed through real-time feedback from the position sensor. When the absolute value of the cumulative deviation is ≥0.1 tons, the proportional coefficient and integral coefficient are increased to quickly eliminate the cumulative error; when the absolute value of the cumulative deviation is <0.1 tons, the proportional coefficient is decreased and the derivative coefficient is increased to suppress real-time rate fluctuations. If the feedback parameter is switched, within the transition period T (T = 5~20 seconds), the weight of the previous feedback parameter is linearly reduced from 100% to 0%, and the weight of the new feedback parameter is linearly increased from 0% to 100%. During the transition period, the PID output value is the weighted sum of the old and new feedback parameters to avoid sudden changes in the opening of the coal flow valve. The weighted value is set by the operator based on experience. Subsequently, the processed real-time injection rate deviation value is smoothed by a first-order low-pass filter.

[0065] This invention significantly shortens the system response time and effectively reduces overshoot caused by hysteresis by real-time monitoring of the injection rate and dynamically switching feedback parameters (hourly cumulative deviation and real-time deviation). Combined with an adaptive PID controller, it automatically adjusts the proportional, integral, and derivative coefficients according to the magnitude of the deviation, eliminating accumulated errors while suppressing real-time fluctuations, greatly reducing oscillation adjustments of the coal flow valve, and ensuring the stability and continuity of the injection rate. A first-order low-pass filter (α = 0.1–0.3) is introduced to smooth the real-time deviation value, effectively filtering out noise interference and avoiding malfunctions. When the absolute value of the hourly cumulative deviation is ≥ 0.1 tons, the accumulated error is quickly eliminated by increasing the proportional and integral coefficients; when the deviation is small, the derivative action is enhanced to suppress small fluctuations, achieving precise control. A gradual variable transition strategy (T = 5–20 seconds) is adopted, and a smooth transition between old and new parameters is achieved through linear adjustment of weights when switching feedback parameters, avoiding abrupt changes in the coal flow valve opening command and further ensuring the stability of system operation. Through a closed-loop control architecture (real-time monitoring → calculation → adaptive adjustment → execution feedback) and dynamic parameter optimization logic, the system reduces the need for manual intervention, enhances its adaptability, and can adapt to complex operating conditions such as nitrogen pressure fluctuations, meeting the stringent requirements of blast furnace production for real-time stable injection. In practical applications, the real-time injection rate deviation can be controlled within 2t / h, and the hourly cumulative injection deviation is reduced to below 0.5t, effectively improving the utilization rate of blast furnace pulverized coal, reducing energy consumption, and ensuring the long-term stable and efficient operation of the blast furnace.

[0066] Although embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations, and modifications are possible without departing from the spirit and scope of the invention and the appended claims. Therefore, the scope of the invention is not limited to the contents disclosed in the embodiments.

Claims

1. A method for controlling the real-time injection rate deviation of pulverized coal injection in a blast furnace, characterized by: steps include: (1) Monitor the blowing rate in real time and calculate the deviation between the real-time blowing rate and the set rate; (2) Calculate the cumulative hourly spraying deviation and take the absolute value; (3) When the absolute value of the hourly cumulative injection deviation is ≥0.1 tons, the hourly cumulative injection deviation is used as the feedback parameter of PID control to adjust the opening of the coal flow valve; (4) When the absolute value of the cumulative hourly injection deviation is less than 0.1 tons, the processed real-time injection rate deviation value is used as the feedback parameter of PID control to adjust the opening of the coal flow valve. In step (2), the method for calculating the hourly cumulative injection deviation is as follows: ； The formula for calculating the output value of a PID controller based on its feedback parameters is as follows: ； in: The output value of the PID controller. This is the proportional gain coefficient. This is the integral gain coefficient. This is the error value at the current moment. At the initial moment, The differential gain coefficient; In steps (3) and (4), a gradual variable transition strategy is adopted when the feedback parameter is switched. During the transition period T, the weight of the previous feedback parameter is linearly reduced from 100% to 0%, and the weight of the new feedback parameter is linearly increased from 0% to 100%. During the transition period, the PID output value is the weighted sum of the old and new feedback parameters, where the weighting value is set by the staff based on experience.

2. The method according to claim 1, characterized in that: In step (1), the weight data of the spray can is collected every second and stored in an array variable, the difference between adjacent seconds is calculated and stored in a second array variable; the average difference is calculated every 5 seconds as the instantaneous spray rate of the initial spraying stage.

3. The method according to claim 1, characterized in that: The optimization logic in steps (3) and (4) of the PID control parameters is as follows: When the absolute value of the cumulative deviation is ≥0.1 tons, increase the proportional coefficient and integral coefficient to quickly eliminate the cumulative error; When the absolute value of the cumulative deviation is less than 0.1 tons, the proportional coefficient is reduced and the differential coefficient is increased to suppress real-time rate fluctuations.

4. The method according to claim 1, characterized in that: The real-time jetting rate deviation value after processing in step (4) is smoothed using a first-order low-pass filter. The filtering formula is as follows: ； Where: α = 0.1 - 0.3, x n y represents the current real-time deviation value. n This is the filtered output value.

5. A real-time pulverized coal injection rate deviation control system for blast furnaces, characterized in that: The method for implementing any one of claims 1 to 4 includes a PLC system, a PID controller, a jetting rate detector, and a jetting system, wherein the PLC system, the PID controller, the jetting rate detector, and the actuator are all connected and configured, and the PLC system includes a real-time monitoring module, a cumulative deviation calculation module, and a feedback parameter selection module. The real-time monitoring module can collect injection rate data and calculate the real-time deviation value. The cumulative deviation calculation module can calculate the hourly cumulative injection deviation and its absolute value. The feedback parameter selection module can select the hourly cumulative deviation or the processed real-time deviation value as the PID input based on the absolute value threshold. The PID controller can output the coal flow valve opening adjustment command based on the selected feedback parameter. The injection system can adjust the injection according to the output of the PID controller.

6. The application of the method as described in any one of claims 1 to 4 or the system as described in claim 5 in the real-time injection rate deviation control of pulverized coal injection in blast furnaces.

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