Sectional type dynamic self-adaptive control method for blast furnace fuel ratio

Abstract

The invention belongs to the technical field of steel smelting process control, and particularly relates to a sectional type dynamic self-adaptive control method for the fuel ratio of a blast furnace, which comprises the following specific steps: S1, determining reference parameters; s2, data acquisition; s3, initial fuel ratio adjustment amplitude calculation: the gas utilization rate and the thermal load parameters are fused, the initial adjustment amplitude is calculated step by step, and the initial fuel ratio adjustment amplitude is obtained through fusion calculation; s4, regulating and controlling the fuel ratio adjustment amplitude limit; s5, threshold guarantee and boundary control are carried out; and S6, controlling output. According to the method, a'adjustment direction and deviation interval 'two-dimensional segmented adjustment mechanism is established, fine control over the fuel ratio is achieved, double threshold values of'fuel ratio boundary and adjustment amplitude boundary' are set, and it is ensured that the furnace condition is stable; closed-loop logic capable of being directly embedded into an existing blast furnace control system is formed, and practicability and adaptability are improved.

Description

Technical Field

[0001] This invention belongs to the field of steel smelting process control technology, specifically relating to a segmented dynamic adaptive control method for blast furnace fuel ratio, which is suitable for precise control of fuel ratio in blast furnace ironmaking process, especially adaptable to the furnace condition stability requirements under complex working conditions, and can be directly embedded into existing blast furnace thermal control systems. Background Technology

[0002] In blast furnace ironmaking, the fuel ratio is a core process parameter that determines energy consumption, smelting costs, and furnace stability: an excessively high fuel ratio increases the consumption of coke, pulverized coal, and other fuels, driving up production costs; an excessively low fuel ratio easily leads to insufficient furnace temperature, charge suspension, and other malfunctions. Currently, fuel ratio control in the industry mainly adopts two methods: manual experience control or fixed threshold control, both of which have significant drawbacks. (1) Manual experience control: It relies on operators to manually adjust parameters such as furnace temperature and gas composition, which has the problems of "strong reliance on experience, lagging adjustment and low accuracy", and is prone to furnace condition fluctuations due to judgment deviations; (2) Fixed threshold control: The adjustment is triggered by a preset single threshold (such as setting the fuel ratio to decrease when it exceeds 550 and increase when it is below 500), or by using a fixed formula to calculate the range (such as adjusting by 5 kg / t regardless of the deviation from the threshold). This cannot adapt to different deviations in working conditions and is prone to over-adjustment (such as using a large range for small deviations) or under-adjustment (such as using a small range for large deviations). Summary of the Invention

[0003] The purpose of this invention is to provide a segmented dynamic adaptive control method and system for blast furnace fuel ratio, which solves the problems of strong reliance on experience, slow adjustment, low accuracy, and inability of fixed threshold control to adapt to different deviations in operating conditions, and the tendency to over-adjust or under-adjust.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A segmented dynamic adaptive control method for blast furnace fuel ratio, the specific steps of which are as follows: Step S1: Determining the reference parameters The baseline parameters for blast furnace operation are dynamically determined, including the baseline fuel ratio (FR_base), the baseline gas utilization rate (η_base), and the baseline heat load (Q_base). Step S2: Data Acquisition Real-time acquisition of current blast furnace operating parameters, including the current fuel ratio (FR). i ), current gas utilization rate (η) i ) and current heat load (Q) i ); Step S3: Calculation of initial fuel ratio adjustment range Based on the benchmark comparison method, the gas utilization rate and heat load parameters are integrated, and the initial fuel ratio adjustment range (Δ0) is calculated step by step by using the difference between the current parameters and the benchmark parameters. Step S4: Fuel ratio adjustment range limit control According to the current fuel ratio (FR) i ) and the preset limit fuel ratio (FR) j The relationship between the magnitudes of the initial fuel ratio adjustment (Δ0) and the direction of the initial fuel ratio adjustment range (Δ0) are used to calculate the fuel ratio adjustment range limit (Δ1) using a differentiated segmented calculation formula, and the initial fuel ratio adjustment range (Δ0) is limited to this fuel ratio adjustment range limit (Δ1). Step S5: Threshold Guarantee and Boundary Control The limit value (Δ1) of the fuel ratio adjustment range after the restriction and control is judged by a threshold. If its absolute value is less than the preset minimum effective adjustment range (Δ_min), the final adjustment range (Δ_final) is set as the minimum effective adjustment range (Δ_min) and the original adjustment direction is retained; otherwise, the limit value (Δ1) of the fuel ratio adjustment range is used as the final adjustment range (Δ_final). Step S6: Control Output Output the fuel ratio control command corresponding to the final adjustment range (Δ_final) to the blast furnace control system.

[0005] Preferably, the initial fuel ratio adjustment magnitude (Δ0) in step S3 includes: The first adjustment component is calculated based on the difference in gas utilization rate: Δ_η = -(η_n) i -η_base)×k_η, where k_η is the adjustment coefficient; The second adjustment component is calculated based on the difference in heat load: Δ_Q=(Q i -Q_base)×γ, where γ is the heat load-fuel ratio conversion coefficient; The first adjustment component and the second adjustment component are weighted and fused: Δ0 = α × Δ_η + β × Δ_Q, where α and β are weighting coefficients, and α + β = 1. If Δ0 < 0, it is a decrease in fuel ratio; if Δ0 ≥ 0, it is an increase in fuel ratio.

[0006] Preferably, the specific details of the fuel ratio adjustment range limitation control in step S4 are as follows: When the initial fuel ratio adjustment magnitude (Δ0) indicates a reduction in the fuel ratio: If the current fuel ratio (FR) i ) greater than the limit fuel ratio (FR) j Then the first calculation formula is used: Δ1=[(FR i -FR j ) / 5]×k1+B1; If the current fuel ratio (FR) i ) less than or equal to the limit fuel ratio (FR) j Then the second calculation formula is used: Δ1=[(FR i -FR j ) / 5]×k2+B1; Where k1 and k2 are slope coefficients, B1 is a constant term, and k1 ≠ k2; When the initial fuel ratio adjustment magnitude (Δ0) indicates an increase in the fuel ratio: use the third calculation formula: Δ1=[(FR j -FR i ) / 5]×k3+D1; where k3 is the slope coefficient and D1 is the constant term.

[0007] Preferably, in step S4, after calculating the fuel ratio adjustment range limit value (Δ1), a range limiting operation is performed: the absolute value of the initial fuel ratio adjustment range (Δ0) is compared with the size of the fuel ratio adjustment range limit value (Δ1); If |Δ0|>Δ1, then Δ1 is used as the adjustment range to be operated on in subsequent steps; If |Δ0|≤Δ1, then the subsequent steps use |Δ0| as the adjustment range to be operated on.

[0008] Preferably, in step S4, the limiting fuel ratio (FR) j The value range is from 515 kg / t to 525 kg / t.

[0009] Preferably, the minimum effective adjustment range (Δ_min) in the threshold protection and boundary control step S5 is 1 kg / t.

[0010] The core parameters are defined as follows:

[0011] The system that implements the above method includes a benchmark parameter calculation module, a real-time data acquisition module, an initial fuel ratio adjustment range calculation module, an adjustment range limit control module, a threshold guarantee module, and a control output module. All modules are linked together through industrial Ethernet communication.

[0012] The baseline parameter calculation module is responsible for collecting and calculating stable operating condition data, and calculating and updating FR_base, η_base, and Q_base; the real-time data acquisition module is used to connect the blast furnace sensor and the data acquisition system, and to collect and filter FR_base. i η i Q i The initial fuel ratio adjustment range calculation module performs the calculation of Δ_η, Δ_Q, and Δ1; the adjustment range limit control module adjusts the adjustment direction and FR accordingly. iCalculate Δ1; the threshold protection module performs the calculation of Δ_final and fuel ratio interval verification; the control output module generates execution instructions and sends them to the existing blast furnace control program, and synchronizes data to the monitoring system.

[0013] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: (1) High control precision: The adjustment rules are segmented according to the degree of deviation from the benchmark value, and a two-dimensional segmented adjustment mechanism of "adjustment direction and deviation range" is established to achieve fine control of fuel ratio. It does not rely on experience and quickly completes the fine response to the deviation of fuel ratio, avoiding the roughness problem of "one-size-fits-all" control with fixed threshold control. (2) Strong system stability: Set dual thresholds for fuel ratio boundary (to prevent fuel ratio from exceeding the reasonable range) and adjustment range boundary (to prevent the adjustment amount from being invalid or excessive), and introduce lower limit threshold control to prevent the adjustment command from being too small or negative under critical operating conditions, thus ensuring the stability of furnace conditions; (3) Strong adaptability: This method adapts to various working conditions from high fuel ratio to low fuel ratio. The system automatically selects the optimal adjustment path based on real-time data and has good robustness to different production states. It forms a closed-loop logic that can be directly embedded into the existing blast furnace control system, improving practicality and adaptability. Detailed Implementation

[0014] The technical solution of the present invention will be described in detail below with reference to the embodiments. Example 1

[0015] For the real-time fuel ratio control system of Taiyuan Iron & Steel Group's No. 6 blast furnace, a segmented dynamic adaptive control method for the blast furnace fuel ratio is adopted. The specific steps are as follows: S1: Determination of reference parameters The system automatically collects stable operating data from the past 12-48 hours, calculates the baseline fuel ratio (FR_base), baseline gas utilization rate (η_base), and baseline heat load (Q_base), and forms a dynamic baseline library with FR_base=519kg / t, η_base=48%, and Q_base=13800 (10MJ / t). S2: Data Acquisition The current fuel ratio (FR) is collected in real time through the sensors and data acquisition system of the blast furnace thermal control system. i ), current gas utilization rate (η) i ) and current heat load (Q) i The sampling frequency is set to 1 time / 10 minutes, FR i =505kg / t、η i =50%, Q i =11800 (10MJ / t); S3: Calculation of Initial Fuel Ratio Adjustment Range Based on the benchmark comparison method, and integrating gas utilization rate and heat load parameters, the initial fuel ratio adjustment range (Δ0) is calculated step by step: (1) Calculate the adjustment range based on the difference in gas utilization rate: Calculation formula: Δ_η = -(η) i -η_base)×k_η, where k_η is an adjustment coefficient, representing the fuel ratio affected by each 1% gas utilization rate. Set k_η=4.5, Δ_η=-(50-48)×4.5=-9kg / t; Note: Current gas utilization rate η i When the value is higher than the baseline value η_base, Δ_η is negative, indicating that the fuel ratio needs to be reduced (energy utilization efficiency is improved, which can reduce fuel consumption); conversely, the fuel ratio needs to be increased. (2) Calculate the adjustment range based on the difference in heat load: Calculation formula: Δ_Q = (Q i -Q_base)×γ, where γ is the heat load-fuel ratio conversion coefficient, set γ=0.003, Δ_Q=(11800-13800)×0.003=-6kg / t; Note: The heat load / fuel ratio conversion coefficient is determined through heat balance. The current heat load Q i When the heat load is higher than the baseline heat load, Δ_Q is a positive value (requiring an increase in fuel ratio for heat compensation), and vice versa. (3) Determine the overall adjustment range Δ1: Calculation formula: Δ0=α×Δ_η+β×Δ_Q, where α and β are weighting coefficients, and α+β=1. Set α=0.5, β=0.5, Δ0=0.5×(-9)+0.5×(-6)=-7.5kg / t; Explanation: By adjusting the magnitude through the fusion of α and β weight coefficients, multi-parameter collaborative optimization is achieved, avoiding adjustment deviations caused by fluctuations in a single parameter; If Δ0 < 0, it means reducing the fuel ratio; if Δ0 ≥ 0, it means increasing the fuel ratio. In order to calculate the required adjustment range of the fuel ratio in the subsequent calculation, Δ0 takes its own absolute value. Since Δ0 < 0, it means reducing the fuel ratio. The absolute value of Δ0 is 7.5. S4: Fuel ratio adjustment range limitation control Based on the adjustment direction and the current fuel ratio level, the fuel ratio adjustment range limit (Δ1) is calculated using a differentiated formula. Fuel ratio reduction calculation: FR j =520kg / t, because FR i ≤FR j : Δ1=[(FR i -FR j) / 5]×k2+B1, where k2 is the slope coefficient and B1 is a constant term. Let k2=1.0 and B1=6.5. Δ1=[(505-520) / 5]×1.0+6.5=3.5kg / t. Since Δ0>Δ1, Δ1 takes the value 3.5. S5: Threshold Protection and Boundary Control Threshold filtering is applied to Δ1 to obtain the final adjustment magnitude (Δ_final): The minimum effective adjustment range Δ_min = 1 kg / t, and the absolute value of Δ1 is 3.5 ≥ Δ_min. Therefore, Δ_final is a reduction in fuel ratio of 3.5 kg / t. S6: Control Output (Module: Control Output Module) Δ_final is converted into an execution instruction, which sends "reduce fuel ratio by 3.5 kg / t" to the blast furnace fuel ratio control program to complete the automatic control of fuel ratio. Example 2

[0016] For the real-time fuel ratio control system of Taiyuan Iron & Steel Group's No. 6 blast furnace, a segmented dynamic adaptive control method for the blast furnace fuel ratio is adopted. The specific steps are as follows: S1: Determination of reference parameters The system automatically collects stable operating data from the past 12-48 hours, calculates the baseline fuel ratio (FR_base), baseline gas utilization rate (η_base), and baseline heat load (Q_base), and forms a dynamic baseline library with FR_base=519kg / t, η_base=48%, and Q_base=13800 (10MJ / t). S2: Data Acquisition The current fuel ratio (FR) is collected in real time through the sensors and data acquisition system of the blast furnace thermal control system. i ), current gas utilization rate (η) i ) and current heat load (Q) i The sampling frequency is set to 1 time / 10 minutes, FR i =535kg / t, η i =45%, Q i =14500 (10MJ / t); S3: Calculation of Initial Fuel Ratio Adjustment Range Based on the benchmark comparison method, and integrating gas utilization rate and heat load parameters, the initial fuel ratio adjustment range (Δ0) is calculated step by step: (1) Calculate the adjustment range based on the difference in gas utilization rate: Calculation formula: Δ_η = -(η i-η_base)×k_η, where k_η is an adjustment coefficient, representing the fuel ratio affected by each 1% gas utilization rate. Set k_η=4.5, Δ_η=-(45-48)×4.5=13.5kg / t; (2) Calculate the adjustment range based on the difference in heat load: Calculation formula: Δ_Q = (Q i -Q_base)×γ, where γ is the heat load-fuel ratio conversion coefficient, set γ=0.003, Δ_Q=(14500-13800)×0.003=2.1kg / t; (3) Determine the overall adjustment range Δ1: Calculation formula: Δ0=α×Δ_η+β×Δ_Q, where α and β are weighting coefficients, and α+β=1. Set α=0.5, β=0.5, Δ0=0.5×13.5+0.5×2.1=7.8kg / t; S4: Fuel ratio adjustment range limitation control When the initial fuel ratio adjustment magnitude (Δ0) indicates an increase in the fuel ratio: use the third calculation formula: FR j =520kg / t, Δ1=[(FR j -FR i ) / 5]×k3+D1; Set k3=0.5, D1=5.0, FR j =520kg / t, Δ1=[(520-535) / 5]×0.5+5.0=3.5kg / t, Δ0>Δ1, so Δ1 takes the value of 3.5; S5: Threshold Protection and Boundary Control If |Δ0|>Δ1, then the subsequent steps use Δ1=3.5 as the adjustment range to be operated on, resulting in the final adjustment range (Δ_final)=3.5; The minimum effective adjustment range Δ_min = 1 kg / t, and the absolute value of Δ1 is 3.5 ≥ Δ_min. Therefore, Δ_final is a reduction in fuel ratio of 3.5 kg / t. S6: Control Output (Module: Control Output Module) Δ_final is converted into an execution instruction, which sends "increase fuel ratio by 3.5 kg / t" to the blast furnace fuel ratio control program to complete the automatic control of fuel ratio.

[0017] After adopting this method, the fuel ratio increase is reduced when the actual fuel ratio is high, and vice versa when the actual fuel ratio is low, to ensure the stability of blast furnace heat control. Taiyuan Iron & Steel Group's No. 6 blast furnace has an annual output of 3.5 million tons. After this control method was put into use, the Si content of blast furnace molten iron decreased by 0.09%, and the blast furnace fuel cost decreased by 22.58 yuan / tFe.

Claims

1. A segmented dynamic adaptive control method for blast furnace fuel ratio, characterized in that, The specific steps are as follows: Step S1: Determine the reference parameters The baseline parameters for blast furnace operation are dynamically determined, including the baseline fuel ratio (FR_base), the baseline gas utilization rate (η_base), and the baseline heat load (Q_base). Step S2: Data Acquisition Real-time acquisition of current blast furnace operating parameters, including the current fuel ratio (FR). i ), current gas utilization rate (η) i ) and current heat load (Q) i ); Step S3: Calculation of initial fuel ratio adjustment range Based on the benchmark comparison method, the gas utilization rate and heat load parameters are combined, and the initial fuel ratio adjustment range (Δ0) is calculated step by step by the difference between the current parameters and the benchmark parameters. The initial fuel ratio adjustment range (Δ0) is then obtained by fusion calculation. Step S4: Fuel ratio adjustment range limit control According to the current fuel ratio (FR) i ) and the preset limit fuel ratio (FR) j The relationship between the magnitudes of the initial fuel ratio adjustment (Δ0) and the direction of the initial fuel ratio adjustment range (Δ0) are used to calculate the fuel ratio adjustment range limit (Δ1) using a differentiated segmented calculation formula, and the initial fuel ratio adjustment range (Δ0) is limited to this fuel ratio adjustment range limit (Δ1). Step S5: Threshold Guarantee and Boundary Control The limit value (Δ1) of the fuel ratio adjustment range after the restriction and control is judged by a threshold. If its absolute value is less than the preset minimum effective adjustment range (Δ_min), the final adjustment range (Δ_final) is set as the minimum effective adjustment range (Δ_min) and the original adjustment direction is retained; otherwise, the limit value (Δ1) of the fuel ratio adjustment range is used as the final adjustment range (Δ_final). Step S6: Control Output Output the fuel ratio control command corresponding to the final adjustment range (Δ_final) to the blast furnace control system.

2. The segmented dynamic adaptive control method for blast furnace fuel ratio according to claim 1, characterized in that, The initial fuel ratio adjustment magnitude (Δ0) calculated in step S3 includes: The first adjustment component is calculated based on the difference in gas utilization rate: Δ_η = -(η_n) i -η_base)×k_η, where k_η is the adjustment coefficient; The second adjustment component is calculated based on the difference in heat load: Δ_Q=(Q i -Q_base)×γ, where γ is the heat load-fuel ratio conversion coefficient; The first adjustment component and the second adjustment component are weighted and fused: Δ0 = α × Δ_η + β × Δ_Q, where α and β are weighting coefficients, and α + β = 1. If Δ0 < 0, it is a decrease in fuel ratio; if Δ0 ≥ 0, it is an increase in fuel ratio.

3. The segmented dynamic adaptive control method for blast furnace fuel ratio according to claim 1, characterized in that, The specific details of step S4, fuel ratio adjustment range limitation control, are as follows: When the initial fuel ratio adjustment magnitude (Δ0) indicates a reduction in the fuel ratio: If the current fuel ratio (FR) i ) greater than the limit fuel ratio (FR) j Then the first calculation formula is used: Δ1=[(FR i -FR j ) / 5]×k1+B1; If the current fuel ratio (FR) i ) less than or equal to the limit fuel ratio (FR) j Then the second calculation formula is used: Δ1=[(FR i -FR j ) / 5]×k2+B1; Where k1 and k2 are slope coefficients, B1 is a constant term, and k1 ≠ k2; When the initial fuel ratio adjustment magnitude (Δ0) indicates an increase in the fuel ratio: use the third calculation formula: Δ1=[(FR j -FR i ) / 5]×k3+D1; where k3 is the slope coefficient and D1 is the constant term.

4. The segmented dynamic adaptive control method for blast furnace fuel ratio according to claim 3, characterized in that, In step S4, after calculating the fuel ratio adjustment range limit value (Δ1), the range limit operation is performed: the absolute value of the initial fuel ratio adjustment range (Δ0) is compared with the size of the fuel ratio adjustment range limit value (Δ1); If |Δ0|>Δ1, then Δ1 is used as the adjustment range to be operated on in subsequent steps; If |Δ0|≤Δ1, then the subsequent steps use |Δ0| as the adjustment range to be operated on.

5. The segmented dynamic adaptive control method for blast furnace fuel ratio according to claim 3, characterized in that, In step S4, the limiting fuel ratio (FR) j The value range is from 515 kg / t to 525 kg / t.

6. The segmented dynamic adaptive control method for blast furnace fuel ratio according to claim 1, characterized in that, The minimum effective adjustment range (Δ_min) in the threshold protection and boundary control step S5 is 1 kg / t.

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