A method for judging blast furnace gas flow distribution based on blast furnace top temperature field

Abstract

This invention discloses a method for determining the distribution of blast furnace gas flow, comprising: setting a calculation cycle; performing the following actions in each calculation cycle: acquiring the temperature distribution of the gas flow at the top of the furnace or the temperature distribution of the material surface at the top of the furnace through a furnace top temperature measuring device, and collecting the temperatures of sampling points for the intermediate ring temperature, center temperature, and edge temperature; calculating the average values ​​of the intermediate ring temperature, center temperature, and edge temperature for the current calculation cycle; calculating the values ​​of parameters characterizing the intermediate gas flow, center gas flow, and edge gas flow based on the average values ​​of the intermediate ring temperature, center temperature, and edge temperature for the current calculation cycle; and determining the changing trends of the parameters characterizing the intermediate gas flow, center gas flow, and edge gas flow based on the data of the current calculation cycle and historical data, adjusting the blast furnace feeding, and adjusting the intermediate ring gas flow, center gas flow, and edge gas flow accordingly.

Description

Technical Field

[0001] This invention relates to the field of blast furnace ironmaking technology, and in particular to a method for determining the distribution of blast furnace gas flow based on the temperature field at the top of the blast furnace. Background Technology

[0002] A blast furnace is a massive countercurrent reaction vessel, essentially a black box, making its internal conditions difficult to detect. Changes in blast furnace conditions lag significantly in response to operating parameters. Blast furnace gas is generated by the reaction of hot air blown in through the tuyeres with coke and pulverized coal in the tuyeres area. As it rises, it undergoes complex interactions with multiple phases within the blast furnace, with numerous physicochemical phenomena occurring simultaneously. Its volume, composition, temperature, and pressure all change. From its generation in the hearth to its final discharge from the top, the entire process of blast furnace gas takes only a few tens of seconds. It carries a wealth of timely information about the blast furnace, making the identification of blast furnace gas particularly important.

[0003] Existing technologies have used image processing to evaluate blast furnace gas flow, but these methods only establish the relationship between image grayscale and gas flow intensity. They lack location information that is of most concern to blast furnace operators and cannot indicate whether the central or peripheral gas flow is stronger.

[0004] The trends in the development intensity of the gas flow, the surface temperature of the burden, and the cross-shaped temperature measurement at the top of the furnace are consistent. Under normal production conditions, the burden exhibits a regular layered distribution within the blast furnace, and the overall temperature field shows a certain regularity. Based on the changes in the surface temperature field or the distribution of the cross-shaped temperature measurement, the shape of the gas flow and the relative strengths of the central and peripheral gas flows can be roughly determined. Summary of the Invention

[0005] The purpose of this invention is to provide a method for judging the strength of blast furnace gas flow based on the temperature field at the furnace top, which can promptly determine the current gas flow distribution in the blast furnace and help blast furnace operators make daily adjustments.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for determining the distribution of gas flow in a blast furnace includes setting a calculation period; and performing the following steps in each calculation period:

[0008] Step S1: Obtain the temperature distribution of the airflow at the top of the furnace or the temperature distribution of the material surface at the top of the furnace through the furnace top temperature measuring device, and collect the temperature of the middle ring temperature, center temperature and edge temperature sampling points; calculate the average value of the middle ring temperature, the average value of the center temperature and the average value of the edge temperature for the current calculation cycle;

[0009] Step S2: Calculate the values ​​of the parameters used to characterize the intermediate airflow, central airflow, and edge airflow based on the average values ​​of the intermediate ring temperature, the center temperature, and the edge temperature in the current calculation cycle; determine the changing trends of the parameters characterizing the intermediate airflow, central airflow, and edge airflow based on the data of the current calculation cycle and historical data, adjust the blast furnace feeding, and adjust the intermediate ring airflow, central airflow, and edge airflow.

[0010] Furthermore, in step S1, the furnace top temperature measuring device is a furnace top infrared temperature measuring device, which obtains the temperature distribution of the material surface at the furnace top; the method for selecting the sampling points of the intermediate ring temperature, center temperature and edge temperature is as follows: starting from the center point of the material surface, it is divided into multiple concentric circles from the inside to the outside, and the average value of the temperature value in each ring is calculated;

[0011] The center temperature is the temperature at the center point of the material surface; the edge temperature is the average temperature value of the outermost ring; the middle ring temperature is the average temperature value of the two middle rings, or the average temperature value of the middle ring.

[0012] Furthermore, in step S1, the furnace top temperature measuring device is a cross-shaped thermometer, which is used to obtain the temperature distribution of the furnace top gas.

[0013] The method for selecting the sampling points for the intermediate ring temperature, center temperature, and edge temperature is as follows: Based on the distribution of the temperature measuring points of the cross thermometer, starting from the temperature measuring point at the very center of the cross thermometer, divide it into n-1 concentric circles from the inside out; record the temperature of the center temperature measuring point, and calculate the average temperature of the four temperature measuring points on each concentric circle.

[0014] The center temperature is the temperature of the central measuring point of the cross temperature measurement, the edge temperature is the average of the temperature values ​​of the four measuring points on the outermost concentric circles, and the middle ring temperature is the average of the temperature values ​​of the other measuring points excluding the center and edge temperature measuring points.

[0015] Furthermore, in step S2, the temperature of the middle annulus is used as a parameter characterizing the middle airflow. The temperature of the middle annulus is the average of the temperature values ​​of the two innermost rings. The change in the temperature of the middle annulus is used to measure the change in the airflow at the center of the blast furnace.

[0016] Set the lower and upper threshold values ​​for the temperature of the intermediate ring zone;

[0017] If the temperature of the intermediate ring is lower than the lower threshold, it indicates that the airflow in the intermediate ring of the blast furnace is weak in the current calculation cycle, and the method of loosening the airflow in the intermediate ring should be adopted.

[0018] If the temperature of the intermediate ring zone is greater than the upper threshold, it indicates that the airflow in the intermediate ring zone of the blast furnace is strong in the current calculation cycle, and adjustment methods to suppress the airflow in the intermediate ring zone can be adopted.

[0019] Furthermore, the method for adjusting the loose intermediate ring airflow is to reduce the ore-coke ratio; the method for adjusting the intermediate ring airflow is to increase the ore-coke ratio.

[0020] Furthermore, in step S2, the ratio FZC of the average center temperature value and the intermediate ring temperature value is used as a parameter characterizing the central airflow; the change in FZC is used to measure the change in the central airflow of the blast furnace.

[0021] The change in FZC is represented by the ratio of the FZC data in the current calculation period to the FZC data in the previous calculation period or the period before that.

[0022] Set the lower and upper threshold values ​​for the change in FZC;

[0023] If FZC is less than the lower threshold, it is considered that the central gas flow of the blast furnace is weakening, and the adjustment method of developing the central gas flow can be adopted; if FZC is greater than the upper threshold, it is considered that the central gas flow of the blast furnace is strengthening, and the adjustment method of suppressing the central gas flow can be adopted.

[0024] Furthermore, the method for adjusting the central airflow is to increase the amount of central coke; the method for adjusting the central airflow is to reduce the amount of central coke.

[0025] Furthermore, in step S2, the average value of the edge temperature and the average value of the center temperature, FZWD, are used as parameters characterizing the edge airflow; the change in FZWD is used to measure the change in the blast furnace edge airflow.

[0026] The change in FZWD is represented by the ratio of the FZWD data in the current calculation period to the FZWD data in the previous calculation period or the period before that:

[0027] Set the lower and upper threshold values ​​for the change in FZWD;

[0028] If the change in FZWD is less than the lower threshold, it is considered that the edge gas flow of the blast furnace is weakening, and the adjustment method of developing the edge gas flow is adopted.

[0029] If the change in FZWD is greater than the upper threshold, it is considered that the edge gas flow of the blast furnace is becoming stronger, and adjustment methods to suppress the edge gas flow are adopted.

[0030] Furthermore, the adjustment methods for developing edge airflow are to increase the amount of edge coke or decrease the amount of edge ore; the adjustment methods for suppressing edge airflow are to decrease the amount of edge coke or increase the amount of edge ore.

[0031] The present invention achieves the following technical effects:

[0032] The method for determining the gas flow distribution in a blast furnace according to the present invention can determine the current gas flow distribution in the blast furnace based on the temperature field at the furnace top, thus helping blast furnace operators to make daily adjustments. Attached Figure Description

[0033] Figure 1 This is the flowchart of the method for determining the blast furnace gas flow distribution according to the present invention. Figure 1 ;

[0034] Figure 2 This invention relates to a schematic diagram of a furnace top temperature measurement setting;

[0035] Figure 3 This is the flowchart of the method for determining the blast furnace gas flow distribution according to the present invention. Figure 2 . Detailed Implementation

[0036] To further illustrate the various embodiments, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention, primarily used to illustrate the embodiments, and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementations and the advantages of the present invention.

[0037] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0038] Example 1

[0039] like Figure 1 As shown in the figure, this embodiment provides a method for determining the distribution of blast furnace gas flow based on an infrared temperature measurement device, including setting a calculation cycle (e.g., one day as a calculation cycle); and performing the following steps in each calculation cycle:

[0040] Step S1: Obtain the temperature distribution of the material surface at the top of the furnace using an infrared temperature measuring device; calculate the average value of the temperature in the middle ring, the average value of the temperature in the center, and the average value of the temperature at the edge for the current calculation cycle.

[0041] Specifically, in each calculation cycle, starting from the center point of the material surface, it is divided into multiple concentric circles from the inside out, and the average temperature value in each circle is calculated.

[0042] In practice, a calculation cycle is typically set to one day, or 24 hours. The number of concentric circles can be set as needed; for example, six circles, from the outside in, would be used to represent the average daily temperature within each circle, denoted as T1, T2, T3, T4, T5, and T6. Figure 3In the diagram, T1, T2, T3, T4, T5, and T6 represent the corresponding temperature measurement points.

[0043] Step S2: Calculate the values ​​of the parameters used to characterize the intermediate airflow, central airflow, and edge airflow based on the average values ​​of the intermediate ring temperature, the center temperature, and the edge temperature in the current calculation cycle; determine the changing trends of the parameters characterizing the intermediate airflow, central airflow, and edge airflow based on the data of the current calculation cycle and historical data, adjust the blast furnace feeding, and adjust the intermediate ring airflow, central airflow, and edge airflow.

[0044] (1) Judgment of intermediate airflow:

[0045] The change in the intermediate annular zone temperature FZMD is used to measure the change in the airflow in the intermediate annular zone of the blast furnace.

[0046] The lower threshold fzmd_1 and upper threshold fzmd_2 of FZMD are determined based on the characteristics of the blast furnace.

[0047] In this embodiment, the temperature of the middle ring zone, FZMD, is equal to the average of T3 and T4, denoted as FZMD = (T3 + T4) / 2. The temperature of the middle ring zone can also be represented by the average of the remaining temperature points, T0, after removing the temperature points near the center T6 and the edge T1, denoted as FZMD = T0 = (T2 + T3 + T4 + T5) / 4.

[0048] When FZMD is less than fzmd_1, it indicates that the airflow in the middle ring of the blast furnace is weak on that day. The ore-coke ratio in the middle ring can be appropriately reduced or other methods of adjusting the airflow in the middle ring can be adopted.

[0049] When FZMD is greater than fzmd_2, it indicates that the airflow in the middle ring of the blast furnace is relatively strong on that day. The ore-coke ratio in the middle ring can be appropriately increased or other adjustment methods to suppress the airflow in the middle ring can be adopted.

[0050] The intermediate ring temperature FZMD can also be equal to the average value of T2~T5, denoted as FZMD = (T2+T3+T4+T5) / 4.

[0051] (2) Determining the central airflow:

[0052] The change in the gas flow at the center of the blast furnace is measured by the change in the ratio of the average daily temperature T6 at the center point to the FZMD of the intermediate ring zone, FZC.

[0053] The change in FZC is expressed as the ratio of the current day's FZC to the data from the day before yesterday or yesterday.

[0054] If the change in FZC is less than the set lower threshold fzc_1, it is considered that the central airflow of the blast furnace is weakening. The amount of central coke can be appropriately increased or other adjustment methods to develop the central airflow can be adopted.

[0055] If the change in FZC exceeds the set upper threshold fzc_2, it is considered that the central airflow of the blast furnace is becoming stronger. The amount of central coke can be appropriately reduced or other adjustment methods to suppress the central airflow can be adopted.

[0056] (3) Judgment of edge airflow:

[0057] Take the daily average of the four edge points in the four directions as T1, and calculate the average of T1 and the center point T6 as FZWD.

[0058] The change in FZWD is expressed as the ratio of the current day's FZWD to the FZWD data from the day before yesterday or yesterday.

[0059] If the change in FZWD is less than the set lower threshold fzwd_1, it is considered that the edge gas flow of the blast furnace is weakening. The amount of edge coke can be appropriately increased or the amount of edge ore can be reduced or other adjustment methods to develop the edge gas flow can be adopted.

[0060] If the change in FZWD exceeds the set upper threshold fzwd_2, it is considered that the edge airflow of the blast furnace is becoming stronger. The amount of edge coke can be appropriately reduced or the amount of edge ore can be increased, or other adjustment methods to suppress the edge airflow can be adopted.

[0061] Example 2

[0062] like Figure 3 As shown, this invention provides a method for determining the distribution of blast furnace gas flow based on a cross-shaped thermometer, including setting a calculation cycle (e.g., one day as a calculation cycle); and performing the following steps in each calculation cycle:

[0063] Step S1: Obtain the temperature distribution of the airflow at the top of the furnace using a cross thermometer, and collect the temperatures of the middle ring temperature, center temperature, and edge temperature sampling points; calculate the average values ​​of the middle ring temperature, center temperature, and edge temperature for the current calculation cycle.

[0064] In this embodiment, according to the thermocouple distribution of the cross thermometer, the daily average temperature of the central measuring point of the cross thermometer is used as the center temperature, denoted as T6; the daily average temperature of the four measuring points on the outermost concentric circles is used as the edge temperature, denoted as T1; and the daily average temperature of the remaining points after removing T6 and T1 is used as the middle ring temperature, denoted as T0. The middle ring temperature can also be obtained in other ways, such as using the average of T3 and T4.

[0065] Step S2: Calculate the values ​​of the parameters used to characterize the intermediate airflow, central airflow, and edge airflow based on the average values ​​of the intermediate ring temperature, the center temperature, and the edge temperature in the current calculation cycle; determine the changing trends of the parameters characterizing the intermediate airflow, central airflow, and edge airflow based on the data of the current calculation cycle and historical data, adjust the blast furnace feeding, and adjust the intermediate ring airflow, central airflow, and edge airflow.

[0066] The difference between Example 2 and Example 1 lies in step S1. The two methods use different types of equipment and different methods for obtaining the temperature of the middle ring, the center temperature, and the edge temperature.

[0067] The method for determining the distribution of blast furnace gas flow in this invention can determine the current gas flow distribution in the blast furnace based on the temperature field at the furnace top, helping blast furnace operators to make daily adjustments and adjust the blast furnace feeding.

[0068] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which shall be within the scope of protection of the invention.

Claims

1. A method for determining the distribution of gas flow in a blast furnace, characterized in that, This includes setting the calculation cycle; in each calculation cycle, the following steps are performed: Step S1: Obtain the temperature distribution of the airflow at the top of the furnace or the temperature distribution of the material surface at the top of the furnace using the furnace top temperature measuring device, and collect the temperatures of the middle ring temperature, center temperature, and edge temperature sampling points; calculate the average values ​​of the middle ring temperature, center temperature, and edge temperature for the current calculation cycle. Step S2: Based on the average values ​​of the middle annular zone temperature, the center temperature, and the edge temperature in the current calculation cycle, calculate the values ​​of the parameters used to characterize the airflow in the middle annular zone, the center airflow, and the edge airflow; based on the data of the current calculation cycle and historical data, determine the changing trends of the parameters characterizing the airflow in the middle annular zone, the center airflow, and the edge airflow, adjust the blast furnace feed, and adjust the airflow in the middle annular zone, the center airflow, and the edge airflow. In step S1, in each calculation cycle, starting from the center point of the material surface, it is divided into multiple concentric circles from the inside out, and the average temperature in each circle is calculated; the outermost circle is the edge circle, and the innermost circle is the center circle. In step S2, the average value FZMD is calculated based on the average temperature of each remaining ring after removing the central and edge rings in the current calculation cycle. This average value is used as a parameter to characterize the airflow in the middle ring. FZMD is used to measure the change in the airflow in the middle ring of the blast furnace: a lower threshold and an upper threshold for FZMD are set. If FZMD is less than the lower threshold, it indicates that the airflow in the middle ring of the blast furnace is weak in the current calculation cycle, and an adjustment method to loosen the airflow in the middle ring is adopted. If FZMD is greater than the upper threshold, it indicates that the airflow in the middle ring of the blast furnace is strong in the current calculation cycle, and an adjustment method to suppress the airflow in the middle ring is adopted. In step S2, the ratio FZC is calculated based on the average value of the central ring temperature and FZMD in the current calculation cycle, and FZC is used as a parameter characterizing the central airflow. The change in FZC is used to measure the change in the central airflow of the blast furnace. The change in FZC is represented by the ratio of the FZC data in the current calculation cycle to the FZC data in the previous calculation cycle or the calculation cycle before that. A lower threshold and an upper threshold for the change in FZC are set. If the change in FZC is less than the lower threshold, it is considered that the central airflow of the blast furnace is weakening, and an adjustment method to develop the central airflow is adopted. If the change in FZC is greater than the upper threshold, it is considered that the central airflow of the blast furnace is strengthening, and an adjustment method to suppress the central airflow is adopted. In step S2, the average value FZWD of the edge ring temperature and the center ring temperature in the current calculation cycle is calculated, and FZWD is used as a parameter characterizing the edge airflow. The change in FZWD is used to measure the change in the blast furnace edge airflow. The change in FZWD is represented by the ratio of the FZWD data in the current calculation cycle to the FZWD data in the previous calculation cycle or the calculation cycle before that. A lower threshold and an upper threshold for the change in FZWD are set. If the change in FZWD is less than the lower threshold, it is considered that the edge airflow of the blast furnace is weakening, and an adjustment method to develop the edge airflow is adopted. If the change in FZWD is greater than the upper threshold, it is considered that the edge airflow of the blast furnace is strengthening, and an adjustment method to suppress the edge airflow is adopted.

2. The method for determining the distribution of blast furnace gas flow as described in claim 1, characterized in that, The method for adjusting the airflow in the loose intermediate ring zone is to reduce the ore-coke ratio; the method for adjusting the airflow in the suppressed intermediate ring zone is to increase the ore-coke ratio.

3. The method for determining the distribution of blast furnace gas flow as described in claim 1, characterized in that, The method to adjust the central airflow is to increase the amount of central coke; the method to suppress the central airflow is to reduce the amount of central coke.

4. The method for determining the distribution of blast furnace gas flow as described in claim 1, characterized in that, The adjustment methods for developing edge airflow are to increase the amount of edge coke or decrease the amount of edge ore; the adjustment methods for suppressing edge airflow are to decrease the amount of edge coke or increase the amount of edge ore.

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