Blast furnace airflow closed-loop control method

Abstract

The invention discloses a blast furnace airflow closed-loop control method which comprises the following steps: acquiring charge level data and material distribution parameters through online laser scanning equipment and furnace top material distribution equipment, calculating the size of a blast furnace center funnel and the material distribution speed, calculating a center coke material distribution error, establishing a center coke control algorithm, and controlling the material distribution speed by controlling the opening degree of a material flow valve. Therefore, the center coke distribution error is adjusted, and closed-loop control of blast furnace airflow is achieved. According to the embodiment of the invention, the size of the central funnel and the material distribution speed of the blast furnace are calculated in real time, and the data are transmitted to the controller to control the opening of the material flow valve, so that the problem of inaccurate material distribution control caused by incapability of detecting the central material speed can be solved, and furnace core accumulation caused by excessive central coke quantity is avoided.

Description

Technical Field

[0001] The invention relates to the field of blast furnace airflow control, and in particular to a blast furnace airflow closed-loop control method. Background Art

[0002] The core of blast furnace operation is to control the reasonable distribution and stability of blast furnace airflow by adjusting the blast parameters at the bottom of the blast furnace and the distribution of the upper burden, which in turn affects the stable operation and economic and technical indicators of the blast furnace. Once the blast furnace enters the smelting state, the lower part of the blast furnace cannot adjust the air inlet area and tuyere size during the production process, so the adjustment of the airflow is mainly completed by the upper burden by controlling the distribution of the upper airflow. However, the blast furnace is an extra-large, high-temperature, closed chemical reactor, and the distribution of the burden on the top of the furnace cannot be directly measured. In order to obtain the burden distribution on the top of the blast furnace and then accurately control the airflow distribution, blast furnace workers have carried out a lot of fruitful work over the years and have made certain progress.

[0003] Since the results of the top position scan are superimposed step by step from the bottom of the furnace, and the working state of the lower part, especially the shape of the dead material column and the soft melting zone, directly determine the shape of the material surface on the top of the furnace, for example, under the same raw fuel quality and the same upper and lower operation systems, the shape of the material surface scanned each time is also different. Compared with the normal operation of the furnace hearth, the material speed in the center is reduced when the furnace hearth is piled up, and the working condition inside the blast furnace cannot be detected. Therefore, the existing airflow distribution or O / C distribution based on online measurement is established to establish a relationship with the soft melting zone mode or blast furnace condition production data, and the established corresponding mode has deviations in closed-loop charging control and cannot accurately express the control of the central coke amount. Summary of the invention

[0004] To solve the above problems, the present invention extracts the important center funnel size based on the material surface data scanned online, establishes a closed-loop control method for the center coke amount, and ensures the stability of the activity of the blast furnace dead coke pile.

[0005] A blast furnace airflow closed-loop control method comprises the following steps:

[0006] S1 collects data information;

[0007] S2 calculates the size of the blast furnace center hopper;

[0008] S3 calculates the hourly material rate;

[0009] S4 calculates the center focus distribution error;

[0010] S5 establishes a center focus closed-loop control algorithm.

[0011] Furthermore, in the step S1, through the online laser scanning start signal and the coordinates of each radial point, the collected data information includes the name of the charge, the weight of the material tank, the opening of the material flow valve, the number of circles set for each gear of coke, the tilting signal of each gear of coke, the material flow valve opening signal, the material empty signal, and the probe raising signal.

[0012] Furthermore, the step S2 is specifically as follows:

[0013] S21 links the blast furnace online laser material surface scanning equipment and the blast furnace top material distribution equipment;

[0014] S22 obtains the coordinates of each laser point on the material surface other than the central part;

[0015] S23 uses the Lagrange difference algorithm to calculate and obtain the coordinates of each laser point in the center;

[0016] S24 combines the directly acquired fabric laser point coordinates and the center part coordinates calculated by using the difference algorithm into complete material surface curve coordinates;

[0017] S25 calculates the ore descent speed;

[0018] S26 calculates the size of the central funnel.

[0019] Specifically, the coordinates of the laser point in step S22 are represented by B i (r, z); the coordinates of each laser point in step S23 are represented by C i (r, z); the material surface curve coordinates in step S24 are expressed as A i (r,z).

[0020] Specifically, in step S25, the ore descending speed calculation formula is:

[0021] v=a·r+b, where: v is the ore descending speed, r is the distance from the laser point to the center line of the blast furnace, a is the coefficient, b is the coefficient, i=1,2…N+1, where N means dividing the furnace throat radius into N equal parts.

[0022] The radius of the blast furnace is divided into N equal parts (r1, r2, r3....rN), and the material discharge speed corresponding to each radius is (v1, v2, v3.....vN). Linear fitting is performed on the two sets of data to obtain a linear equation v=a·r+b for the speeds v and r, and the equation is updated regularly.

[0023] Furthermore, the method for calculating the size of the central funnel in step S26 is:

[0024] S261 uses a temperature gun to measure temperature points;

[0025] S262 draws a vertical straight line along each center point of the temperature measuring gun and intersects the fabric to obtain a node;

[0026] S263 calculates the size of the central funnel.

[0027] The radius of the blast furnace is divided into N equal parts, and a laser point is set in each part, including the laser point at the center point, that is, there are N+1 laser points in total, each laser point is a center point of a temperature measuring gun, the laser point at the center point of the blast furnace is set as the center point of the temperature measuring gun, and the laser points in other equal parts are secondary center points of the temperature measuring gun.

[0028] Specifically, the calculation formula for the size of the central funnel is:

[0029] Among them: θ is the size of the funnel in the center, N is the node where the vertical line of the temperature measuring center point of the temperature measuring gun intersects with the material surface, atan is the inverse tangent function, is the ordinate of the current node on the material surface, is the ordinate of the node in front of the material, is the horizontal coordinate of the current node of the material surface, It is the horizontal coordinate of the node in front of the material.

[0030] Furthermore, in step S3, the calculation method of hourly materials is as follows: the material name, the opening of the material flow valve, and the lifting of the probe are associated, and the material name coke is used as the standard, and the time difference between the material flow valve and the probe action is matched, and the time of the current 5 batches of materials is calculated, and the time t of the current first coke lifting signal is calculated. 1批 , and the time t of the sixth coke lifting signal 6批 The difference is the fabric time of 5 batches of materials, that is, t 5批料 =t 1批 -t 6批 , the unit is min, then the hourly material rate: p = 60 / t 5批料 5, unit is batch / hour.

[0031] Furthermore, the step S4 is specifically as follows:

[0032] S41 associates all action signals of the entire coke distribution process with the second-level real-time data of the tank weight and sets the allowable error;

[0033] S42 calculates the actual weight of the center focus;

[0034] S43 calculates the center focus error and compares it with the set error;

[0035] S44 establishes a coke flow precision control method.

[0036] Specifically, the actual weight calculation formula of the center focus is:

[0037] wt 中心焦 =wt 倾动角度 -wt 料空 Where: wt 中心焦 is the actual weight of the center focus, wt 倾动角度 is the weight of the tank at a certain tilting angle, wt 料空 The weight of the material tank corresponding to the empty signal;

[0038] The central focus error calculation formula is:

[0039] E 中心焦 =(wt 中心焦 -wt 中心焦设定 ) / wt 中心焦设定 Where: E 中心焦 is the central focus error, wt 中心焦 is the actual weight of the center focus, wt 中心焦设定 Set the weight for the center focus at that moment.

[0040] Furthermore, the coke flow precision control method comprises the following specific steps:

[0041] S441 obtains historical center focal weight data;

[0042] S442 establishes a functional relationship between the actual material distribution time and the actual material flow valve opening;

[0043] S443 automatically adjusts the actual material flow valve opening by comparing the actual material flow valve opening and the material distribution error.

[0044] Specifically, the actual flow valve opening calculation formula is:

[0045] f=a·(CB / t 布料 )+b, where: f is the opening of the material flow valve, CB is the coke distribution batch, t distribution is the actual distribution time, a is the coefficient, and b is the coefficient.

[0046] Furthermore, the step S5 is specifically as follows:

[0047] S51 performs real-time diagnosis of current material speed and center coke hopper;

[0048] S52 calculates the center focus ratio;

[0049] S53 calculates the number of center focus circles based on the center focus ratio and fabric matrix settings;

[0050] S54 compares theoretical material distribution time with actual material distribution time, and sets the distribution matrix and material flow valve opening;

[0051] S55 sends the material distribution matrix and the material flow valve opening setting to the feeding system for closed-loop control;

[0052] S56 automatically calculates the actual center focus error and actual material feeding time for each batch of materials, compares the actual center focus error with the set error, and sends the comparison results to the feeding system for closed-loop control.

[0053] Furthermore, in step S56, when the central focus error is greater than the set error, the material flow valve opening is recalculated and the material flow valve opening is adjusted through the feeding system.

[0054] Beneficial effects of the present invention:

[0055] Based on online laser scanning equipment and furnace top distribution equipment, real-time data mining and big data analysis technology are used to calculate the material surface funnel size and the actual center coke amount in real time. Through the center funnel size, the actual center coke amount and blast furnace production characterization parameters, a dynamic closed-loop control method for the center coke is established. In daily production, especially during wet quenching, the material flow valve opening can be accurately controlled to avoid excessive center coke amount and accumulation in the furnace core. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. The drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. For those skilled in the art, other drawings can be obtained based on the drawings without paying creative work.

[0057] Figure 1 This is a flow chart of closed-loop control of blast furnace airflow according to the present invention;

[0058] Figure 2 A schematic diagram of the central part funnel calculation of an embodiment of the present invention;

[0059] Figure 3 This is a timing diagram of blast furnace burden distribution according to an embodiment of the present invention. DETAILED DESCRIPTION

[0060] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0061] Reference Figure 1 As shown, one embodiment of the present invention is a blast furnace airflow closed-loop control method, comprising the following steps:

[0062] S1 collects data information;

[0063] S2 calculates the size of the blast furnace center hopper;

[0064] S3 calculates the hourly material rate;

[0065] S4 calculates the center focus distribution error;

[0066] S5 establishes a center focus closed-loop control algorithm.

[0067] In step S1, the online laser scanning start signal, the online laser scanning radial point coordinates, collect the name of the charge, the weight of the material tank, the opening of the material flow valve, the number of circles of each coke gear, the tilting signal of each coke gear, the material flow valve opening signal, the material empty signal, and the probe ruler raising signal.

[0068] In step S2, the blast furnace online laser material surface scanning equipment and the blast furnace top distribution equipment are interlocked, that is, the laser trigger signal is automatically associated with the material flow valve opening signal and the probe ruler raising signal of each batch of materials. After each distribution, the laser is automatically started to scan the material surface with a certain delay to obtain the coordinates B of each laser point on the material surface. i (r, z), where the center of the blast furnace is the flame area and the material surface cannot be scanned. The Lagrange interpolation algorithm is used to calculate the coordinates C of each laser point in the center. i (r, z). Finally, the coordinates obtained by direct scanning and the coordinates of the center obtained by difference are combined into the complete material surface curve coordinates A i (r, z), i = 1, 2...N+1, where N represents dividing the furnace throat radius into N equal parts.

[0069] Since the coke and ore feeding is carried out continuously, the difference between the shape scanned after the ore feeding is completed and the shape scanned before the coke feeding begins, divided by the time difference between the two, is the ore descent speed. After normalization, the radial descent speed after the ore feeding is obtained as: v = a·r+b, where a>0, b>0. That is, the radial descent speed is a linear equation, the feeding speed in the center is the lowest, and the feeding speed in the edge is the fastest. When the center of the blast furnace is inactive and the overall feeding speed of the blast furnace is reduced, the center is most affected and the funnel becomes flat. Therefore, it is particularly important to quantitatively describe the size of the funnel in the center.

[0070] Calculate the size of the funnel at the center as Figure 2 As shown: In this example, a cross temperature measuring gun is used to measure the temperature points. The cross temperature measuring gun is a measuring rod. The radius of the blast furnace is divided into N equal parts, and N+1 measuring rods are set at equal distances from the center to the furnace wall, that is, T 中心 、T1、T2、T3....T N, where the center point T1 is set as the center point, and the other temperature measuring points are sub-center points. According to the distribution characteristics of the temperature measuring points of the cross temperature measuring gun, a vertical line is drawn along the sub-center point of the temperature measuring gun and the intersection with the material surface is a node, then there are N nodes A1, A2...A N , the formula for the size of the central funnel is:

[0071]

[0072] θ is the size of the funnel at the center, N is the node where the vertical line of the temperature measuring center point of the temperature measuring gun intersects with the material surface, where:

[0073] atan is the inverse tangent function, is the ordinate of the current node on the material surface, is the ordinate of the node in front of the material, is the horizontal coordinate of the current node of the material surface, It is the horizontal coordinate of the node in front of the material.

[0074] The shape of the material surface in the center is corrected based on the measurement results during wind stop.

[0075] In this embodiment, the process of calculating the central hourly material speed is as follows: the material name, the material flow valve opening and the probe ruler are associated, the material name coke is used as the standard, the material flow valve and the probe ruler action time difference are matched, the time of the current 5 batches of materials is calculated, and the time t of the current first coke ruler raising signal is calculated. 1批 , and the time t of the sixth coke lifting signal 6批 The difference is the fabric time of 5 batches of materials, that is, t 5批料 =t 1批 -t 6批 , the unit is min, then the hourly material rate: p = 60 / t 5批料 5, unit is batch / hour.

[0076] To achieve closed-loop control of airflow, it is first necessary to ensure the accuracy of the amount of center coke. Since the physical and chemical properties of each batch of materials are not exactly the same, and there are errors in the setting of the material flow valve angle, there are certain errors in the material distribution. The chute may stop rotating but the material is still being distributed, and the furnace charge may have been distributed but the distribution program has not yet ended. This error causes the amount of center coke to fluctuate, which affects the stability of the center airflow. Therefore, it is necessary to set an acceptable allowable error E0 and calculate the actual error of the center coke.

[0077] The process of calculating the center focus distribution error is as follows: Figure 3As shown in the figure, due to the fluctuation of the furnace charge performance of each batch of materials, all the action signals in the whole coke distribution process, such as the material flow valve opening signal, the tilting signals of each gear used: tilting 1, tilting 2...tilting 13, and the empty material signal, are associated with the second-level real-time data of the material tank weight. The actual weight of the central coke can be calculated. Taking the tilting 8 moment as an example, the difference between the material tank weight corresponding to the tilting 8 moment and the material tank weight corresponding to the empty material signal is as follows: Figure 3 Shown: wt 中心焦 =wt 倾动8 -wt 料空 The actual material distribution time is the time difference from the opening of the material flow valve to the emptying of the material, that is: t 布料 =t 料空 -t 料流阀打开 .

[0078] According to the setting of coke batch CB, the number of coke circles in each gear is set, and the center coke weight is set to: wt 中心焦设定 =CB*n 13 / (n1+n2+n3+n4+n5+n6+n7+n8+……+n 13 ), the chute rotation time per circle is t0, and the setting feeding time is t 设定 =(n1+n2+n3+n4+n5+n6+n7+n8+……+n 13 )*t0.

[0079] In this embodiment, the 4 gears of 9, 10, 11 and 12 do not lay material, the number of turns is set to 0, and the other gears are used for laying material.

[0080] Of course, in other applications, the fabric conditions of each gear can be changed according to actual conditions.

[0081] Table 1: Number of laps for each gear

[0082] Gear 1 2 3 4 5 6 7 8 9 10 11 12 13 Number of laps n1 n2 n3 n4 n5 n6 n7 n8 0 0 0 0 n13

[0083] The formula for calculating the center focus error is: E 中心焦 =(wt 中心焦 -wt 中心焦设定 ) / wt 中心焦设定 , E0 is the setting error.

[0084] Establish a method for controlling the precision of coke flow: Based on the historical data of the past 100 batches, establish the actual distribution time t 布料 The functional relationship between the actual flow valve opening f, f = a·(CB / t 布料 )+b, where CB is the coke batch, a and b are coefficients calculated based on past historical data. The equation is automatically trained and updated as the fabric is continuously produced.

[0085] In step S5, production data at the hourly level with a production volume higher than the lower limit and within the range of 600°C ± 50 for the central air flow are selected, and a classification analysis is performed on the size θ of the central funnel and the proportion p of the central coke based on the blast furnace charge rate. That is, the charge rate is divided into different gears according to the numerical size, v0 - v1, v1 - v2, v2 - v3, and the size θ of the central funnel and the proportion p of the central coke within each gear are taken respectively. Based on this, a closed-loop adjustment plan for the proportion of central coke is formulated.

[0086] Table 2 Central Coke Closed-Loop Control Plan

[0087] Gear Feed speed Center Funnel Center focus ratio 1 v0 <v≤v1 <![CDATA[θ0]]> <![CDATA[p0]]> 2 v1 <v≤v2 <![CDATA[θ1]]> <![CDATA[p1]]> 3 <h2 style=";text-align:left;direction:ltr">v2 <v≤v3 <h2 style=";text-align:left;direction:ltr"> <![CDATA[θ2]]> <![CDATA[p2]]>

[0088] Perform real-time diagnosis on the current charge rate and the central coke funnel:

[0089] When the charge rate v0 < v ≤ v1, and the central funnel angle θ < θ0, the proportion of central coke p0;

[0090] When the charge rate v1 < v ≤ v2, the central funnel angle θ < θ1, the proportion of central coke p1;

[0091] When the charge rate v2 < v ≤ v3, the central funnel angle θ < θ2, the proportion of central coke p2;

[0092] Since the charging sequence is from the edge to the center, and the area of the central part is small, the opening degree of the material flow valve directly affects the amount of burden in the central part, especially coke (the center is usually a non-mining area, mainly coke, which is the size of the air flow channel). Therefore, the closed-loop adjustment of the proportion of central coke is achieved by controlling the opening degree of the material flow valve. According to the charging time formula t 设定 =(n1 + n2 + n3 + n4 + n5 + n6 + n7 + n8 + …… + n 13 )*t0, when facing the air flow fluctuation caused by the fluctuation of the coke amount in the central part, the number of charging circles is not adjusted in daily operation, and only the proportion of central coke (number of circles) is adjusted, that is, the opening degree of the material flow valve can be adjusted to achieve.

[0093] Calculate the number of central coke circles and the theoretical charging time t 设定 , and assign t 设定 to t 布料 , and use the formula f = a·(CB / t 布料 ) + b trained by the latest 100 batches of materials in the past to calculate the required opening degree of the material flow valve, and send the charging matrix and the opening degree setting of the material flow valve to the PLC of the charging system for closed-loop control.

[0094] In this embodiment, the relationship between the actual charging time t 布料 and the theoretical charging time t 设定 , and the number of central coke circles is: the actual charging time t 布料It is the difference between the time when the material flow valve is open and the time when the material is empty, that is: t 布料 =t 料空 -t 料流阀打开 This value is used to calculate the flow valve opening formula for every 100 batches of material f = a·(CB / t 布料 )+b. The center coke ratio p is used to adjust the opening of the material flow valve according to the actual furnace conditions (material speed and center funnel size). According to the center coke ratio p=n 13 / (n1+n2+n3+n4+n5+n6+n7+n8+……+n 13 ) can calculate the center focal circle number n 13 , then the theoretical laying time t 设定 =(n1+n2+n3+n4+n5+n6+n7+n8+……+n 13 )*t0, where t0 is the rotation time of the chute per circle.

[0095] t 设定 Assign to t 布料 Specifically, according to the functional relationship between the opening of the material flow valve and the actual material distribution time, the actual material distribution time t is adjusted by learning and controlling the historical material flow valve opening. 布料 Approaching the set cloth time t 设定 The functional relationship between the opening of the material flow valve and the actual material distribution time is: f = a·(CB / t 布料 )+b, a and b are calculated based on the correlation between f and CB / t distribution collected from the past 100 batches of materials, forming a complete dynamic adjustment logic for the material flow valve based on the furnace conditions.

[0096] In order to maintain the actual center focus at a stable level, the actual center focus error E is automatically calculated for each batch of materials. 中心焦 , actual fabric time t 布料 , when |E 中心焦 |>E0, that is, when the center focus error is greater than the set error, the formula f=a·(CB / t 布料 )+b calculates the new material flow valve opening and sends it to the feeding system for closed-loop control.

[0097] Although the preferred implementation cases of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms of specific changes without departing from the scope of protection of the invention spirit and claims, which all fall within the scope of protection of the present invention.

Claims

1. A blast furnace airflow closed-loop control method, characterized in that: The following steps are involved: S1 collects data information; S2 calculates the size of the blast furnace center hopper; S3 calculates the hourly material rate; S4 calculates the center focus distribution error; S5 establishes a center focus closed-loop control algorithm.

2. A blast furnace airflow closed-loop control method according to claim 1, characterized in that: In the step S1, the data information collected by online laser scanning start signal and radial point coordinates include the name of the charge, the weight of the material tank, the opening of the material flow valve, the number of circles set for each coke gear, the tilting signal of each coke gear, the material flow valve opening signal, the material empty signal and the probe raising signal.

3. A blast furnace airflow closed-loop control method according to claim 1, characterized in that: The step S2 is specifically as follows: S21 links the blast furnace online laser material surface scanning equipment and the blast furnace top material distribution equipment; S22 obtains the coordinates of each laser point on the material surface other than the central part; S23 uses the Lagrange difference algorithm to calculate and obtain the coordinates of each laser point in the center; S24 combines the directly acquired fabric laser point coordinates and the center part coordinates calculated by using the difference algorithm into complete material surface curve coordinates; S25 calculates the ore descent speed; S26 calculates the size of the central funnel.

4. A blast furnace airflow closed-loop control method according to claim 3, characterized in that: The coordinates of the laser point in step S22 are represented by B i (r,z); The coordinates of each laser point in step S23 are represented by C i (r,z); The material surface curve coordinates in step S24 are represented by A i (r,z); The calculation formula for the ore descending speed in step S25 is: v=a•r+b Where v is the ore descending speed, r is the distance from the laser point to the center line of the blast furnace, a is the coefficient, b is the coefficient, i=1,2…N+1, where N means dividing the furnace throat radius into N equal parts.

5. A blast furnace airflow closed-loop control method according to claim 4, characterized in that: In step S26, the method for calculating the size of the central funnel is: S261 uses a temperature gun to measure temperature points; S262 draws a vertical straight line along the secondary center point of each temperature measuring gun and intersects the fabric to obtain a node; S263 calculates the size of the central funnel.

6. A blast furnace airflow closed-loop control method according to claim 5, characterized in that: The calculation formula for the size of the central funnel is: in: θ is the size of the funnel in the center, N is the node where the vertical line of the temperature measuring center point of the temperature measuring gun intersects with the material surface, atan is the inverse tangent function, is the ordinate of the current node on the material surface, is the ordinate of the node in front of the material, is the horizontal coordinate of the current node of the material surface, It is the horizontal coordinate of the node in front of the material.

7. A blast furnace airflow closed-loop control method according to claim 1, characterized in that: In step S3, the calculation method of hourly material rate is: p = 60 / t n批料 •n, in batches / hour, where p is the hourly material rate, t n批料 is the fabric time for n batches of material, where n is the number of fabric batches.

8. A blast furnace airflow closed-loop control method according to claim 1, characterized in that: The step S4 is specifically as follows: S41 associates all action signals of the entire coke distribution process with the second-level real-time data of the tank weight and sets the allowable error; S42 calculates the actual weight of the center focus; S43 calculates a center focus error and compares it with a set error; S44 establishes a coke flow precision control method.

9. A blast furnace airflow closed-loop control method according to claim 8, characterized in that: In step S43, the actual weight of the center focus is calculated using the formula: wt 中心焦 =wt 倾动角度 -wt 料空 Where: wt 中心焦 is the actual weight of the center focus, wt 倾动角度 is the weight of the tank at a certain tilting angle, wt 料空 The weight of the material tank corresponding to the empty signal; In step S43, the central focus error calculation formula is: E 中心焦 = (wt 中心焦 -wt 中心焦设定 ) / wt 中心焦设定 Where: E 中心焦 is the central focus error, wt 中心焦 is the actual weight of the center focus, wt 中心焦设定 Set the weight for the center focus at that moment.

10. A blast furnace airflow closed-loop control method according to claim 9, characterized in that: The specific steps of the coke flow precision control method are as follows: S441 obtains historical center focal weight data; S442 establishes a functional relationship between the actual material distribution time and the actual material flow valve opening; S443 automatically adjusts the actual material flow valve opening by comparing the actual material flow valve opening and the material distribution error.

11. A blast furnace airflow closed-loop control method according to claim 10, characterized in that: The actual flow valve opening calculation formula is: f=a•(CB / t 布料 )+b Where: f is the opening of the material flow valve, CB is the coke distribution batch, t distribution is the actual distribution time, a is the coefficient, and b is the coefficient.

12. A blast furnace airflow closed-loop control method according to claim 1, characterized in that: The step S5 is specifically as follows: S51 performs real-time diagnosis of current material speed and center coke hopper; S52 calculates the center focus ratio; S53 calculates the number of center focus circles based on the center focus ratio and fabric matrix settings; S54 compares theoretical material distribution time with actual material distribution time, and sets the distribution matrix and material flow valve opening; S55 sends the material distribution matrix and the material flow valve opening setting to the feeding system for closed-loop control; S56 automatically calculates the actual center focus error and actual material feeding time for each batch of materials, compares the actual center focus error with the set error, and sends the comparison results to the feeding system for closed-loop control.

13. A blast furnace airflow closed-loop control method according to claim 12, characterized in that: In step S56, when the central focus error is greater than the set error, the material flow valve opening is recalculated and the material flow valve opening is adjusted through the feeding system.

Images