Method for evaluating working state of hearth

Abstract

The invention relates to the field of iron and steel metallurgy blast furnace ironmaking, in particular to a method for evaluating the working state of a hearth, which analyzes, calculates and quantifies the furnace core temperature, the hearth temperature measurement temperature uniformity and the bosh gas index weight through a large amount of blast furnace operation data, and establishes the correlation with a circumference active index. And analyzing and calculating to obtain a reference value of the circumferential activity index according to the operation condition of the furnace condition. And establishing a circumferential activity index division interval rule for judging the working state of the hearth. A quantitative blast furnace working state evaluation mode is provided for a blast furnace operator in time, a basis is provided for blast furnace operation adjustment, the good working state of a hearth is kept, the long-period stable and smooth operation of the furnace condition is kept, and safe, long-life, efficient and stable production of the blast furnace is achieved.

Description

Technical Field

[0001] The invention relates to the field of iron and steel metallurgy blast furnace ironmaking, and in particular to a method for evaluating the working state of a furnace. Background Art

[0002] The blast furnace hearth is the source of blast furnace smelting, providing gas and heat for the blast furnace smelting process. The initial distribution state of the gas flow generated in the hearth not only determines the heat distribution and temperature distribution of the hearth cross section, but is also the key to the gas flow and temperature distribution along the entire height of the blast furnace. Therefore, the working state of the blast furnace hearth has long-term and important significance for whether the blast furnace smelting can achieve the production goals of "high efficiency, high quality, low consumption, and long life".

[0003] The working state of the hearth is a key link that directly determines the production of blast furnaces. However, with the continuous improvement of smelting technology and smelting equipment, the occurrence of freezing or accumulation accidents in blast furnace hearths is extremely rare. The daily production fluctuations of the hearth, such as changes in raw material quality, changes in equipment operating status, changes in airflow distribution and other uncertain factors, are the main reasons for the changes in the working state of the hearth. Once the state of the hearth changes, it will bring huge losses to production for a period of time.

[0004] At present, most blast furnace operators use hearth activity to describe the working status of the blast furnace hearth, but the methods for judging hearth activity are different. Currently, Taigang blast furnace mainly relies on hearth temperature changes and the operator's experience summary to judge hearth activity, lacking systematic quantitative evaluation and accurate, real-time prediction.

[0005] Therefore, a quantifiable method must be provided to judge the working status of the furnace hearth. By systematically sorting out the factors that affect the activity of the furnace hearth, screening important factors, and reasonably controlling the values ​​of each influencing factor, the furnace hearth can be continuously kept active and in good working condition, thereby ensuring the stable and smooth operation of the blast furnace and achieving the production goals of "high efficiency, high quality, low consumption, and long life".

[0006] This method aims to provide a method for evaluating the working state of the hearth, and proposes to quantify the hearth activity with a circular activity index. The circular activity index combines factors such as the hearth core temperature, the hearth side wall temperature uniformity, and the bosh gas index of the blast furnace. Through the weight of each factor, the hearth activity is maintained near the circular activity index, maintaining good activity and good hearth working state, and achieving the production goals of "high efficiency, high quality, low consumption, and long life". Summary of the invention

[0007] The purpose of the present invention is to provide a method for evaluating the working state of a furnace cylinder in view of the above problems.

[0008] The object of the present invention is achieved as follows: A method for evaluating the working state of a furnace comprises the following steps: Step 1: obtaining the basic value of the blast furnace operating parameters, the furnace core temperature T 芯 , Temperature T of each point on the circumference of the brick lining at the bottom elevation below the iron mouth of the furnace side wall 1i , Temperature T of each point on the brick lining circumference of the taphole area 2i And blast furnace bosh gas index X BG , where i = 1, 2, 3, ... n; Step 2: Calculate the temperature uniformity of the furnace bottom elevation below the iron mouth of the furnace side wall T average 1, and the temperature uniformity of the iron mouth area T average 2; T average T average Where:

[0009] Step 3: Collect and calculate the quantified furnace core temperature, furnace cylinder temperature uniformity and furnace gas index weight, establish the correlation formula with the circular activity index K, and calculate the K benchmark value through the blast furnace operation data combined with the relevant indicators of blast furnace operation, and divide the interval rules; K = T core / 100 + T average 1 / 150 + T average 2 / 150 + 0.01*X BG , K benchmark = 3.25 ± 0.25; Step 4: Obtain parameters in real time to calculate the circular activity index K value and compare it with the K benchmark to determine the working status of the furnace.

[0010] The working state of the furnace is determined in step 4 as follows: if the K value falls within the range of K reference = 3.25 ± 0.25, it indicates that the furnace activity is good; if it is outside the range, it indicates that the furnace activity is deteriorated.

[0011] The beneficial effects of the present invention are as follows: the method uses blast furnace operation data to analyze and calculate the quantified furnace core temperature, furnace hearth temperature uniformity and furnace bosh gas index weight, and establishes its correlation with the circumferential activity index. And according to the furnace operation conditions, the circumferential activity index reference value is obtained by analysis and calculation. A circumferential activity index division interval rule for determining the working state of the furnace hearth is established. A quantitative blast furnace working state evaluation model is provided to the blast furnace operator in a timely manner, providing a basis for blast furnace operation adjustment, timely adjusting the furnace condition, maintaining the furnace hearth working state in good condition, maintaining the furnace condition stable and smooth for a long period of time, and realizing safe, long-lived, efficient and stable production of the blast furnace. It has important guiding significance for blast furnace operators to judge the working state of the furnace hearth.

[0012] TISCO Ironmaking Plant 1800m 3 The blast furnace was put into operation on July 31, 2007. It has always paid attention to the management of the working status of the furnace. After years of operation experience, this method was invented. The blast furnace operator adjusts the operation system in time according to the changes in the furnace status to keep the furnace status in good working condition. As of December 2023, it has been in production and operation for 16 years. The cumulative iron output per unit furnace capacity is 14,800 t / m 3, reaching the advanced level of domestic long-life blast furnaces. The furnace has been in operation for 16 years without any maintenance, the cooling wall of the entire furnace is intact, the furnace shell is intact, and the temperature of the furnace brick lining is controlled, achieving safe, long-life, efficient and stable production of the blast furnace.

[0013] In May 2023, according to the production and operation plan, intensified smelting will increase the blast furnace utilization factor to 2.9. By regulating the working state of the hearth, the intensified smelting air supply ratio will be increased to 2.11, and the utilization factor will increase from 2.6 to 2.9. After the smelting intensity is improved, there is no abnormal erosion of the furnace brick lining temperature, and all temperature points are under control. DETAILED DESCRIPTION

[0014] The present invention adopts a basic technical concept: the working state of the blast furnace hearth characterizes the blast furnace slag and iron discharge capacity and the blast furnace hearth air volume and the acceptance capacity of the furnace belly gas, thereby affecting the degree of smooth operation of the blast furnace condition. The working state of the hearth is evaluated by the circular activity index K, which combines the furnace core temperature, the temperature uniformity of the furnace side wall and the furnace belly gas index. The furnace core temperature represents the state of coke and dead coke piled in the furnace hearth, and the temperature uniformity of the furnace hearth side wall effectively represents the discharge, penetration, and circulation of molten iron in the furnace hearth. The furnace belly gas index represents the ability of the furnace hearth to accept air volume to enhance smelting. The three are effectively combined to reflect the working state of the blast furnace hearth. Through daily control of the circular activity index K, the furnace hearth is kept in good working condition, and the long-term stable and smooth operation of the blast furnace condition is achieved.

[0015] The specific technical scheme of the present invention is as follows: 1. The basic value of the blast furnace operating parameters and the furnace core temperature T are obtained through the blast furnace computer system. 芯 , Temperature T of each point on the circumference of the brick lining at the bottom elevation below the iron mouth of the furnace side wall 1i , Temperature T of each point on the brick lining circumference of the taphole area 2i And blast furnace bosh gas index X BG (wherein i=1, 2, 3,...n).

[0016] 2. Calculate the temperature uniformity T of the furnace bottom elevation below the iron mouth of the furnace side wall 均1 , Temperature uniformity of the taphole area T 均2 .

[0017]

[0018]

[0019] Where:

[0020]

[0021] 3. Collect and calculate a large amount of data to quantify the furnace core temperature, furnace cylinder temperature uniformity and furnace gas index weight, establish a correlation formula with the circular activity index K, and calculate K through the daily operation data of the blast furnace combined with various related indicators of the blast furnace operation. 基准 Value, interval division rules.

[0022] K=T 芯 / 100+T 均1 / 150+T 均2 / 150+0.01*X BG ,

[0023] K 基准 =3.25±0.25.

[0024] 4. Obtain parameters in real time to calculate the circular activity index K value and K 基准 Compare and determine the working status of the furnace.

[0025] The invention has been applied in 1800m2 of Taigang Ironmaking Plant. 3 Application on blast furnaces. Taking the actual production from March to May 2023 as an example, the specific implementation plan is as follows: 1. From March 9 to 21, 2023, the temperature at the 0° elevation of the hearth bottom elevation on the side of the furnace increased significantly (from 240°C to 417°C, an increase of 177°C). Through calculation, it is obtained that the circular activity index K remains between 3.09 and 3.28 in the middle and early part of the year.

[0026] Among them: March 13th T 均1 =40, T 均2 =24, X BG =4727.3, T 芯 =203.7

[0027] K=T 芯 / 100+T 均1 / 150+T 均2 / 150+0.01*X BG

[0028] =203 / 100+40 / 150+24 / 150+0.01*4727.3=3.09

[0029] March 20T 均1 =57, T 均2 =27, X BG =4780.7, T 芯 =207.7

[0030] K=T 芯 / 100+T 均1 / 150+T 均2 / 150+0.01*X BG

[0031] =207.7 / 100+57 / 150+27 / 150+0.01*4780.7=3.28.

[0032] 2. The circle activity index K gradually increased on March 21, and rose to 3.50 on March 29, and reached a peak of 3.71 on April 7. During this period, the actual circle activity index K exceeded K 基准 =3.25±0.25, judging that the working condition of the furnace hearth has deteriorated, and the highest temperature point has not exceeded the historical highest value. It is judged that the slag skin on the side wall in this direction is aggravated by the circulation of molten iron in the furnace hearth, and the slag skin on the side wall is eroded.

[0033] Among them: March 21 T 均1 =67, T 均2 =27, X BG =4802.2, T 芯 =211.2

[0034] K=T 芯 / 100+T 均1 / 150+T 均2 / 150+0.01*X BG

[0035] =211.2 / 100+67 / 150+27 / 150+0.01*4802.2=3.38

[0036] March 29thT 均1 =75, T 均2 =29, X BG =4811.3, T 芯 =217

[0037] K=T 芯 / 100+T 均1 / 150+T 均2 / 150+0.01*X BG

[0038] =217 / 100+75 / 150+29 / 150+0.01*4811.3=3.5

[0039] April 7thT 均1 =89, T 均2 =31, X BG =4773.2, T 芯 =227

[0040] K=T 芯 / 100+T 均1 / 150+T 均2 / 150+0.01*XBG

[0041] =227 / 100+89 / 150+31 / 150+0.01*4773.2=3.71.

[0042] 3. By taking the approach of activating the working state of the furnace hearth inside the furnace, the working state of the furnace hearth was gradually changed. On April 27, the circular activity index K recovered to 3.3, the temperature at the 0° elevation of the furnace bottom recovered to normal levels, the temperatures of all points on the side walls of the furnace hearth were normal, the circular activity index K remained near 3.25, within the K reference value range, the working state of the furnace hearth was significantly improved, smelting was intensified in May, the furnace condition remained smooth, and the utilization factor was increased from 2.6 to 2.9.

[0043] Among them: April 27 T 均1 =40, T 均2 =30, X BG =4801.5, T 芯 =219.2

[0044] K=T 芯 / 100+T 均1 / 150+T 均2 / 150+0.01*X BG

[0045] =219.2 / 100+40 / 150+30 / 150+0.01*4801.5=3.3.

[0046] Specific implementation plan II is as follows: On October 25, 2023, the three blast furnaces were shut down for 48 hours for scheduled inspection. After the blast furnaces were shut down, slag iron accumulated in the furnace without heat source, and the temperature gradually dropped. The slag iron on the side wall of the furnace solidified, the furnace volume became smaller, and the dead coke pile permeability became worse. In the early stage after the scheduled inspection and resumption of air on October 27, the furnace working volume was small, the dead coke pile permeability was poor, and the furnace working state was not good. After the air supply was restored, the initial value of the circular activity index K was 2.38 from October 29, which was far lower than the K benchmark value. It was difficult to strengthen the smelting by adding air to the blast furnace, and the utilization coefficient was about 2.7.

[0047] Among them: October 29th T 均1 =15, T 均2 =17, X BG =4566.1, T 芯 =187.5

[0048] K=T 芯 / 100+T 均1 / 150+T 均2 / 150+0.01*X BG

[0049] =187.5 / 100+15 / 150+17 / 150+0.01*4566.1=2.7.

[0050] Until November 4, 2023, the circular activity index K rose to 3.07, the working condition of the furnace hearth improved, the furnace condition improved smoothly, it was obviously accepted by enhanced smelting, and the utilization coefficient increased to 2.9.

[0051] Among them: November 4th T 均1 =44, T 均2 =36, X BG =4795.1, T 芯 =189.8

[0052] K=T 芯 / 100+T 均1 / 150+T 均2 / 150+0.01*X BG

[0053] =189.8 / 100+44 / 150+36 / 150+0.01*4795.1=3.07.

[0054] The above description is only a specific embodiment of the present invention, but the structural features of the protection scope of the present invention are not limited thereto. Any changes or modifications made by any technician in the field of the present invention are included in the patent scope of the present invention.

Claims

1. A method for evaluating the working state of a furnace, characterized in that: The following steps are involved: Step 1: Obtain the basic values ​​of blast furnace operating parameters, furnace core temperature T 芯 , Temperature T of each point on the circumference of the brick lining at the bottom elevation below the iron mouth of the furnace side wall 1i , Temperature T of each point on the brick lining circumference of the taphole area 2i And blast furnace bosh gas index X BG , where i = 1, 2, 3, ... n; Step 2: Calculate the temperature uniformity of the furnace bottom elevation below the iron mouth of the furnace side wall T average 1 and the temperature uniformity of the iron mouth area T average 2; Where: Step 3: Collect and calculate the quantified furnace core temperature, furnace cylinder temperature uniformity and furnace gas index weight, establish the correlation formula with the circular activity index K, and calculate the K benchmark value through the blast furnace operation data combined with the relevant indicators of blast furnace operation, and divide the interval rules; K=T core / 100+T average 1 / 150+T average 2 / 150+0.01*X BG , Kbase = 3.25 ± 0.25; Step 4: Obtain parameters in real time to calculate the circular activity index K value and compare it with the K benchmark to determine the working status of the furnace.

2. A method for evaluating the working state of a furnace according to claim 1, characterized in that: The working state of the furnace is determined in step 4 as follows: if the K value falls within the range of K reference = 3.25 ± 0.25, it indicates that the furnace activity is good; if it is outside the range, it indicates that the furnace activity is deteriorated.

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