Online calculation method for voidage of dead stock column in iron notch area of blast furnace hearth

Abstract

The invention relates to an online calculation method for the voidage of a dead stock column in an iron notch area of a blast furnace hearth, and belongs to the technical field of blast furnace ironmaking. Comprising the following steps that 1, hearth geometric parameters, molten iron attributes, tapping data and dead stock column state parameters are obtained; 2, the distance between the molten iron liquid level and the tap hole plane at the beginning of tapping and the distance between the molten iron liquid level and the tap hole plane at the end of tapping are calculated; 3, calculating the voidage of the dead stock column; and 4, repeating the steps 1-3, and calculating the voidage of the dead stock column in the next period. According to the method, the blast furnace dead stock voidage is continuously calculated on line through blast furnace tapping data, the voidage of the blast furnace hearth dead stock in the production and operation process is known in real time, and time and labor are saved.

Description

Technical Field

[0001] The invention relates to an online calculation method for the void fraction of a dead material column in an iron mouth area of ​​a blast furnace hearth, and belongs to the technical field of blast furnace ironmaking. Background Art

[0002] A large amount of high-temperature molten iron and slag is stored in the hearth of a blast furnace. Once the hearth is burned through, a large amount of high-temperature slag and iron will gush out from the burnt-through place, burning the equipment in front of the furnace. If it is not handled properly, it will also cause fires, explosions and other malignant accidents, which will not only lead to huge economic losses, but also seriously threaten the personal safety of on-site workers. Production practice shows that the erosion rate of the lining of the blast furnace hearth determines the life of the blast furnace. When the carbon bricks of the hearth lining are directly washed by the carbon-unsaturated high-temperature molten iron and dissolve and then erode, it is not conducive to the longevity of the hearth. The flow form of the hearth slag and molten iron has an important influence on the carburization behavior of the hearth molten iron and the lining erosion. During the blast furnace smelting process, due to changes in operating parameters such as blast pressure and coke ratio and changes in raw fuel conditions, the porosity of the dead material column may change, and the flow of slag and molten iron in the hearth and the carburization of molten iron are not evenly distributed, resulting in uneven erosion of the hearth lining.

[0003] Studying the porosity of the dead material column in the blast furnace hearth is of great significance for activating the hearth, avoiding abnormal hearth erosion, achieving stable and smooth operation and longevity of the blast furnace, and improving the quality of molten iron. However, due to the high temperature and high pressure working conditions in the blast furnace, there is no way to directly observe and measure the thermal equipment inside the hearth. At present, there are two main methods for measuring the porosity of the dead material column: the first is to remove some of the residual materials in the furnace after the blast furnace is shut down and measure the porosity of the dead material column; the second is to use the tuyere sampling method to measure the porosity of the dead material column in the tuyere area when the blast furnace is shut down. These two methods can only study the porosity of the dead material column in the hearth of the blast furnace in the shutdown state when the blast furnace is overhauled or shut down, but cannot understand the porosity of the dead material column in the hearth of the blast furnace in the production process in real time, cannot adapt to the characteristics of continuous production operations of the blast furnace, and the measurement process is time-consuming and labor-intensive and has poor effectiveness, and has poor guidance for blast furnace production.

[0004] Therefore, it is necessary to propose a simple, efficient and online method to continuously calculate the voidage of the dead material column in the blast furnace. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an online calculation method for the voidage of the dead material column in the iron mouth area of ​​a blast furnace hearth in view of the above-mentioned prior art, and to realize online continuous calculation of the voidage of the dead material column in the blast furnace by using the blast furnace iron tapping data, so as to understand the voidage of the dead material column in the blast furnace hearth in real time during the production operation, thus saving time and effort.

[0006] The technical solution adopted by the present invention to solve the above problem is: an online calculation method for the void fraction of the dead material column in the iron mouth area of ​​a blast furnace hearth, the calculation method comprising the following steps:

[0007] Step 1: Obtain the geometric parameters of the furnace, molten iron properties, iron tapping data and dead material column status parameters;

[0008] Step 2: Calculate the distance between the molten iron level and the tap hole plane at the beginning of tapping and the distance between the molten iron level and the tap hole plane at the end of tapping;

[0009] Step 3: Calculate the void fraction of the dead material column;

[0010] Step 4: Repeat steps 1 to 3 to calculate the void fraction of the dead material column in the next cycle.

[0011] The geometric parameter of the hearth in the step one is the cross-sectional area of ​​the hearth, the property of the molten iron is the density of the molten iron, the tapping data include the time from the start of tapping to the slag appearance, the molten iron outflow from the start of tapping to the slag appearance, the molten iron production from the start of tapping to the slag appearance, the tapping time, the molten iron outflow during tapping, the molten iron production during tapping, the tapping interval time and the molten iron production during the tapping interval, and the dead material column state parameter is the dead material column porosity measured by sampling or the dead material column porosity calculated in step three.

[0012] In the step 2, according to the law of conservation of mass, the amount of molten iron flowing out of the tapping hole during the period from the start of tapping to the appearance of slag is equal to the initial amount of molten iron above the tapping hole plus the amount of molten iron generated during the period from the start of tapping to the appearance of slag, thereby calculating the distance between the molten iron level and the tapping hole plane at the start of the nth tapping:

[0013]

[0014] Among them, t 见渣(n) The time from the start of the nth tapping to the appearance of slag, min;

[0015] Q 铁(n) The outflow rate of molten iron from the beginning of tapping to the appearance of slag, t / min;

[0016] h 初(n) is the distance between the initial molten iron surface and the tapping hole plane at the beginning of tapping, m;

[0017] A is the cross-sectional area of ​​the furnace, m 2 ;

[0018] ρ is the density of molten iron, t / m 3 ;

[0019] ε n-1 It is the voidage of the dead material column measured by sampling or the voidage of the dead material column at the n-1th tapping time obtained by calculation;

[0020] Y 铁(n) It is the amount of molten iron produced from the start of tapping to the appearance of slag, t / min.

[0021] The distance between the molten iron surface and the tapping hole plane at the end of the nth tapping is:

[0022]

[0023] Among them, t 出铁(n) is the tapping time, min;

[0024] Q (n) is the molten iron outflow during tapping, t / min;

[0025] Y (n) It is the amount of molten iron produced during tapping, t / min.

[0026] In the step 3, for the n+1th tapping, the distance between the molten iron level and the tapping hole plane at the beginning of tapping is the sum of the distance between the molten iron level and the tapping hole plane at the end of the nth tapping and the increase in the molten iron level during the interval between the nth and n+1th tappings, that is:

[0027]

[0028] Among them, t 间 is the time between the nth tapping and the n+1th tapping, min;

[0029] Y 间 It is the amount of molten iron produced during the interval between two adjacent tappings, t / min.

[0030] The distance between the molten iron level and the tapping hole plane at the beginning of the n+1th tapping can also be:

[0031]

[0032] Combining the above two equations, we can get the void fraction of the dead material column as:

[0033]

[0034] When the step 1 is repeated in step 4, the dead material column void fraction is the dead material column void fraction calculated in step 3 in the previous cycle.

[0035] The dead material column void fraction calculation frequency is once for each iron tapping.

[0036] Compared with the prior art, the advantages of the present invention are: an online calculation method for the voidage of the dead material column in the iron mouth area of ​​the blast furnace hearth, which utilizes the blast furnace iron tapping data to realize online continuous calculation of the voidage of the dead material column in the blast furnace, and real-time understanding of the voidage of the dead material column in the blast furnace hearth during production and operation, saving time and effort; it has the advantage of high timeliness, and avoids abnormal hearth erosion for active hearths, thereby achieving stable and smooth operation and longevity of the blast furnace and improving the quality of molten iron, which is of great significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a flow chart of an online calculation method for the void fraction of dead material columns in the iron mouth area of ​​a blast furnace hearth according to an embodiment of the present invention;

[0038] Figure 2 Schematic diagram of the distance between the molten iron surface and the tapping hole plane at the beginning and the end of the n-th tapping in an embodiment of the present invention;

[0039] Figure 3 This is a schematic diagram of the distance between the starting point of the (n+1) tapping and the tapping hole plane in an embodiment of the present invention. DETAILED DESCRIPTION

[0040] The present invention is further described in detail below with reference to the accompanying drawings.

[0041] like Figure 1 As shown, an online calculation method for the void fraction of dead material column in the iron mouth area of ​​a blast furnace hearth in this embodiment comprises the following steps:

[0042] Step 1: Obtain the cross-sectional area of ​​the furnace, the density of molten iron, the time from the start of blast furnace iron tapping to the appearance of slag, the amount of molten iron outflow from the start of iron tapping to the appearance of slag, the amount of molten iron generated from the start of iron tapping to the appearance of slag, the iron tapping time, the amount of molten iron outflow during iron tapping, the amount of molten iron generated during iron tapping, the iron tapping interval time, the amount of molten iron generated during the iron tapping interval and the void fraction parameters of the dead material column.

[0043] Step 2: Calculate the distance between the molten iron level and the tap hole plane at the beginning of tapping and the distance between the molten iron level and the tap hole plane at the end of tapping;

[0044] like Figure 2 As shown in the figure, according to the law of conservation of mass, the amount of molten iron flowing out of the tap hole during the period from the start of tapping to the appearance of slag is equal to the initial amount of molten iron above the tap hole plus the amount of molten iron generated during the period from the start of tapping to the appearance of slag. The distance between the molten iron surface and the tap hole plane at the start of the nth tapping is calculated as:

[0045]

[0046] Among them, t 见渣(n) The time from the start of the nth tapping to the appearance of slag, min;

[0047] Q 铁(n) The outflow rate of molten iron from the beginning of tapping to the appearance of slag, t / min;

[0048] h 初(n) is the distance between the initial molten iron surface and the tapping hole plane at the beginning of tapping, m;

[0049] A is the cross-sectional area of ​​the furnace, m 2 ;

[0050] ρ is the density of molten iron, t / m 3 ;

[0051] ε n-1 It is the voidage of the dead material column measured by sampling or the voidage of the dead material column at the n-1th tapping time obtained by calculation;

[0052] Y 铁(n) It is the amount of molten iron produced from the start of tapping to the appearance of slag, t / min.

[0053] The distance between the molten iron level and the tapping hole plane at the end of the nth tapping is:

[0054]

[0055] Among them, t 出铁(n) is the tapping time, min;

[0056] Q (n) is the molten iron outflow during tapping, t / min;

[0057] Y (n) It is the amount of molten iron produced during tapping, t / min.

[0058] Step 3: Calculate the void fraction of the dead material column;

[0059] like Figure 3 As shown, for the n+1 tapping, the distance between the molten iron level and the tapping hole plane at the beginning of tapping is equal to the distance between the molten iron level and the tapping hole plane at the end of the n tapping plus the increase in the molten iron level during the interval between the n and n+1 tappings, that is:

[0060]

[0061] Among them, t 间 is the time between the nth tapping and the n+1th tapping, min;

[0062] Y 间 It is the amount of molten iron produced during the interval between two adjacent tappings, t / min.

[0063] The distance between the molten iron level and the tapping hole plane at the beginning of the n+1th tapping can also be:

[0064]

[0065] Combining equations (1) and (2), we can get the void fraction of the dead material column as:

[0066]

[0067] Step 4: Repeat steps 1 to 3. The dead material column porosity value can be the dead material column porosity value measured by the most recent sampling or the reference value in the literature. After the first dead material column porosity calculation is completed, the dead material column porosity value in the next cycle of calculation is the dead material column porosity value calculated in step 3 of the previous cycle.

[0068] The calculation frequency of the dead material column void fraction is once for each iron tapping. If the calculation frequency requirement is not high, it can also be calculated once a day.

[0069] Embodiment 1

[0070] An online calculation method for the void fraction of a dead material column in a blast furnace hearth iron mouth area comprises the following steps:

[0071] Step 1: The cross-sectional area A of the furnace is 40.69 m 2 , the density of molten iron is 7138kg / m 3 ; In the iron-making data, when the nth iron-making is performed, the time from the start of iron-making in the blast furnace to the time when slag is seen is t 见渣(n) The amount of molten iron outflow Q from the start of tapping to the slag appearance is 8 minutes 铁(n) The amount of molten iron produced from the start of tapping to the slag formation is 13.27t / min. 铁(n) 2.27t / min, tapping time t 出铁(n) The molten iron outflow during the tapping period is Q (n) The amount of molten iron produced during the tapping period is 3.71t / min. (n) In the iron-making data, when the n+1th iron-making is performed, t 见渣(n+1) The amount of molten iron outflow Q from the start of tapping to the slag appearance is 8 minutes 铁(n+1) The amount of molten iron produced from the start of tapping to the slag formation is 12.01t / min. 铁(n+1) is 2.22t / min, and the interval time between the nth and n+1th tapping is t 间 The amount of molten iron produced during the interval between the nth and n+1th tapping is 18 minutes. 间 is 2.53t / min, and the void fraction of the dead material column ε calculated in step 3 of the previous cycle is n-1 is 0.35.

[0072] Step 2: According to the law of conservation of mass, the amount of molten iron flowing out of the tapping hole during the period from the start of tapping to the appearance of slag is equal to the initial amount of molten iron above the tapping hole plus the amount of molten iron generated during the period from the start of tapping to the appearance of slag.

[0073] The distance between the molten iron surface and the tapping hole plane at the beginning of the nth tapping is:

[0074]

[0075] By importing the data, we can get:

[0076]

[0077] The distance between the molten iron level and the tapping hole plane at the end of the nth tapping is:

[0078]

[0079] By importing the data, we can get:

[0080]

[0081] Step 3: Calculate the void fraction of the dead material column;

[0082] For the n+1 tapping, the distance between the molten iron level and the tapping hole plane at the beginning of tapping is equal to the distance between the molten iron level and the tapping hole plane at the end of the nth tapping plus the increase in the molten iron level during the interval between the nth and n+1th tappings, that is:

[0083]

[0084] Furthermore, the distance between the molten iron surface and the tapping hole plane at the beginning of the n+1th tapping can also be:

[0085]

[0086] Combining the two equations, we can get the void fraction of the dead material column as:

[0087]

[0088] By importing the data, we can get:

[0089]

[0090] Step 4: After the blast furnace completes the n+1th tapping, repeat steps 1 to 3 to start the calculation of a new cycle. After obtaining the tapping data of the new cycle, calculate the dead material column void fraction during the n+1th tapping. During the calculation process of the new cycle, the dead material column void fraction in step 1 is updated to the dead material column void fraction ε calculated in step 3 of the nth tapping cycle.n .

[0091] The blast furnace iron-out data is used to realize online continuous calculation of the void fraction of the blast furnace dead material column, and the void fraction of the blast furnace hearth dead material column in the production process is understood in real time, saving time and effort. It has the advantage of high timeliness, and can avoid abnormal hearth erosion for active hearths, thus achieving stable and smooth operation and longevity of the blast furnace and improving the quality of molten iron, which is of great significance.

[0092] In addition to the above embodiments, the present invention also includes other implementation modes. Any technical solutions formed by equivalent transformation or equivalent replacement should fall within the protection scope of the claims of the present invention.

Claims

1. An online calculation method for the void fraction of the dead material column in the iron mouth area of ​​a blast furnace hearth, characterized in that: The calculation method comprises the following steps: Step 1: Obtain the geometric parameters of the furnace, molten iron properties, iron tapping data and dead material column status parameters; Step 2: Calculate the distance between the molten iron level and the tap hole plane at the beginning of tapping and the distance between the molten iron level and the tap hole plane at the end of tapping; Step 3: Calculate the void fraction of the dead material column; Step 4: Repeat steps 1 to 3 to calculate the void fraction of the dead material column in the next cycle.

2. The online calculation method for the void fraction of the dead material column in the iron mouth area of ​​a blast furnace hearth according to claim 1 is characterized in that: The geometric parameter of the hearth in the step one is the cross-sectional area of ​​the hearth, the property of the molten iron is the density of the molten iron, the tapping data include the time from the start of tapping to the slag appearance, the molten iron outflow from the start of tapping to the slag appearance, the molten iron production from the start of tapping to the slag appearance, the tapping time, the molten iron outflow during tapping, the molten iron production during tapping, the tapping interval time and the molten iron production during the tapping interval, and the dead material column state parameter is the dead material column porosity measured by sampling or the dead material column porosity calculated in step three.

3. The online calculation method for the void fraction of the dead material column in the iron mouth area of ​​a blast furnace hearth according to claim 1 is characterized in that: In the step 2, according to the law of conservation of mass, the amount of molten iron flowing out of the tapping hole during the period from the start of tapping to the appearance of slag is equal to the initial amount of molten iron above the tapping hole plus the amount of molten iron generated during the period from the start of tapping to the appearance of slag, thereby calculating the distance between the molten iron level and the tapping hole plane at the start of the nth tapping: Among them, t 见渣(n) The time from the start of the nth tapping to the appearance of slag, min; Q 铁(n) The outflow rate of molten iron from the beginning of tapping to the appearance of slag, t / min; h 初(n) is the distance between the initial molten iron surface and the tapping hole plane at the beginning of tapping, m; A is the cross-sectional area of ​​the furnace, m 2 ; ρ is the density of molten iron, t / m 3 ; ε n-1 It is the voidage of the dead material column measured by sampling or the voidage of the dead material column at the n-1th tapping time obtained by calculation; Y 铁(n) It is the amount of molten iron produced from the start of tapping to the appearance of slag, t / min. The distance between the molten iron surface and the tapping hole plane at the end of the nth tapping is: Among them, t 出铁(n) is the tapping time, min; Q (n) is the molten iron outflow during tapping, t / min; Y (n) It is the amount of molten iron produced during tapping, t / min.

4. The online calculation method for the void fraction of the dead material column in the iron mouth area of ​​a blast furnace hearth according to claim 1 is characterized in that: In the step 3, for the n+1th tapping, the distance between the molten iron level and the tapping hole plane at the beginning of tapping is the sum of the distance between the molten iron level and the tapping hole plane at the end of the nth tapping and the increase in the molten iron level during the interval between the nth and n+1th tappings, that is: Among them, t 间 is the time between the nth tapping and the n+1th tapping, min; Y 间 It is the amount of molten iron produced during the interval between two adjacent tappings, t / min. The distance between the molten iron level and the tapping hole plane at the beginning of the n+1th tapping can also be: Combining the above two equations, we can get the void fraction of the dead material column as:

5. The online calculation method for the void fraction of the dead material column in the iron mouth area of ​​a blast furnace hearth according to claim 1 is characterized in that: When the step 1 is repeated in step 4, the dead material column void fraction is the dead material column void fraction calculated in step 3 in the previous cycle.

6. The online calculation method for the void fraction of the dead material column in the iron mouth area of ​​a blast furnace hearth according to claim 1 is characterized in that: The dead material column void fraction is calculated once for each iron tapping.

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