JPS6011113A - Method for assuming position of thermal furnace core in shaft furnace - Google Patents

Abstract

PURPOSE:To administrate more precisely a furnace operation and to maintain a reaction in the furnace satisfactorily for a long time by assuming and grasping accurately a thermal furnace core from bosh part to shaft part in horizontal and vertical directions for a long time. CONSTITUTION:Suitable numbers of temp. measuring sensors B having >=2 temp. sensitive parts P1-P6 in a wall thickness direction and for detecting temperatures at different positions in said direction are embedded in a circumferential direction in refractory wall of shaft furnace, and the thermal center in the furnace is obtained by calculation from temp. information groups obtained by each temp. measuring sensor. Next, the thermal center or thermal center of gravity obtained by calculation at each level is made as the thermal furnace core in horizontal direction in each level. The vertical direction distribution of the horizontal direction thermal furnace core in each level is grasped. Furthermore a deviation of thermal furnace core at present time is assumed from true verticality and the horizontal furnace core. Thereby, the position of the thermal furnace core from above the tuyere to the throat can be assumed and grasped exactly in horizontal and vertical directions for a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for estimating the thermal core position during operation of a vertical furnace, such as a blast furnace, and more specifically, the present invention relates to a method for estimating the thermal core position during operation of a vertical furnace, for example, a blast furnace. The present invention relates to a method for accurately estimating and grasping the thermal core position in the horizontal and vertical directions.

A blast furnace is a high-temperature metallurgical reaction furnace that uses iron oxide raw materials such as iron ore and solid reducing agents such as coke.The ultimate purpose of a blast furnace is to ensure that this high-temperature metallurgical reaction (hereinafter referred to as the furnace reaction) is efficient and stable over a long period of time. The goal is to produce large quantities of high-quality pig iron stably, efficiently, and at low cost by manipulating the steel in the same way. By the way, one of the ideal conditions for efficient reaction in the furnace is the thermal center of the furnace (the most thermally balanced point in the furnace) at any height position (hereinafter referred to as level). One example of this is that the axial center (geometric center, hereinafter referred to as the thermal core) of the blast furnace (hereinafter referred to as the thermal core) almost coincides with the blast furnace axis (geometric center, hereinafter referred to as the thermal core). However, inside an operating blast furnace, various phenomena such as ■ shift of the top layer of the so-called softened cohesive zone, ■ sudden blowing of gas in a specific direction, and ■ falling off of refractory walls and deposits occur constantly. As a result, the thermal core is constantly fluctuating. Therefore, during reactor operation management, we must constantly track and understand the fluctuations in this thermal core.
It is believed that if the reactor, fuel charging, and blast pipes are controlled on a case-by-case basis in order to bring the thermal core closer to the structural core, the reaction within the reactor can be maintained to a sufficiently satisfactory level.

However, since it is extremely difficult to directly measure the thermal core, in order to control the reactions inside the reactor, instead of measuring the thermal core, various information inside the reactor, such as the gas flow at the reactor mouth, has been used. Countermeasures are only taken symptomatically using measured distribution data, which is extremely insufficient for reactor operation management. The challenge has been to develop technology that can be used to understand

The present invention was made under these circumstances.1 It is possible to accurately estimate and understand the thermal core from the morning glory section to the reactor chest over a long period of time in the horizontal and vertical directions.
The purpose of this study is to provide a method for estimating the thermal core position that will enable more accurate reactor operation management and maintain reactor reactions at a satisfactory level over a long period of time.

However, the method for estimating the thermal core position according to the present invention is to use a temperature sensor that has two or more temperature sensing parts in the wall thickness direction and detects temperatures at different positions in the wall thickness direction. A suitable number of sensors are embedded in the circumferential direction and height direction in the refractory wall of the furnace, and the thermal core in the horizontal direction of the vertical furnace can be determined by determining the thermal center of the furnace from the temperature information group obtained by each temperature sensor. At the same time, the horizontal thermal cores are obtained at different positions in the vertical direction of the vertical reactor, and the vertical distribution of each of these horizontal thermal cores is grasped, and the horizontal thermal core and its vertical distribution are determined. The gist of this is to estimate the current thermal core position from the above.

The configuration and effects of the method of the present invention will be explained below with reference to the drawings, and each component will be explained in order for ease of understanding. That is, in the method of the present invention, first, (1) a temperature sensor having two or more temperature sensing parts in the wall thickness direction and detecting temperatures at different positions in the wall thickness direction is installed in the refractory wall of the vertical furnace; The thermal center in the furnace can be calculated from the temperature information group obtained by each temperature sensor by setting appropriate mathematics in the circumferential direction: In other words, Fig. 1 (a) shows the case where the method of the present invention is applied to a blast furnace. A schematic explanatory diagram of the case, FIG. 3(b) shows an enlarged view of part b of FIG. 10(a). B indicates a suitable number of temperature sensors (hereinafter simply referred to as sensors 5) installed from the circumferential direction at multiple levels (4 levels in the figure) from the upper part of the tuyere to the furnace chest of blast furnace A; are buried perpendicularly to a position that penetrates through the steel shell C and the skung layer and penetrates almost the inner surface of the refractory wall W or into the furnace. The type and structure of the sensor is not particularly limited as long as it has at least two temperature-sensing parts in the wall thickness direction, but as a preferable example of a sensor B such as the one described in Japanese Utility Model Application No. 55-105140, I will explain the principle of what I proposed. That is, FIG. 2 shows a partially cutaway perspective view of the sensor B, and FIG. 3 shows a developed cross-sectional view corresponding to FIG. 2. In these figures, reference numeral 1 denotes a jacket sheath tube that serves as a protective member for the entire sensor B. 2a is a sheathed thermocouple, and the thermocouple 2aK is inserted with a pair of gold R&94.4' exhibiting a thermoelectric effect, the tip of which is a temperature-measuring junction in the sheath, that is, a temperature-sensing part P1 +
P2H...PIl (hereinafter referred to as P when speaking representatively) is constituted. These temperature-sensing parts P are configured to occupy different positions in the length direction, and in the figure, from the inside of the furnace (I side) to the shell side (0 side), kl is arranged at equal pitches in the length direction. Change p, t P2 1...P6
has been established. Further, a sheathed thermocouple 2b made of the same material as the sheathed thermocouple 2a is connected as a dummy to the tip of the temperature sensitive part P (6 in the figure indicates a connection part).

Further, 3 is a fire-resistant insulating material filled in the outer sheath tube 1, and in order to suppress the influence of thermal disturbance as much as possible, a material having a thermal conductivity matching the fire-resistant g characteristic is used. Therefore, it can be said that the temperature measurement performance of each temperature sensing part P in such a sensor B is sufficiently reliable in terms of sheath strength and durability. Furthermore, Utility Model Application No. 57-81531 proposed by the present applicant
By using the No. 2 sensor, it can be used safely for a long period of time regardless of wear and tear on the fireproof wall. Also, in Fig. 1(b), 8 is a heat flow calculation indicator installed outside the blast furnace.
In the indicator 8, the furnace inside heat flow Qij is calculated as shown in equation (2) according to the set calculation equation of equation (■) below.

It goes without saying that the number of temperature measurements to be adopted can be determined arbitrarily, but from the viewpoint of accuracy, it is preferable to calculate the heat flow as close to the inside of the furnace as possible. The first and second temperature measurement values (Q and 2 for heat flow) were adopted, and the temperature sensing part was moved to the outside of the furnace so that the current heat flow near the innermost surface could be calculated depending on the wear status of the refractory wall. Just go.

The temperature information group obtained from the temperature sensor is not limited to the various heat flows mentioned above, but also includes the temperature measurement value itself at each temperature sensing part, and the trigger response analysis method developed by the present inventors.
Although the furnace wall surface temperature and furnace wall surface heat flow estimated using Japanese Patent Publication No. 57-51444 are also included, the following explanation will take as an example a case where heat flow is adopted as the temperature information group.

That is, when determining the thermal center in the furnace from each heat flow QI2 (hereinafter referred to as Qs) obtained by each temperature sensor for Lebel as described above, one of the following two methods is used. You can do it based on this.

(B. A method of approximating the circumferential measurement result of Qs with a circle and finding the center in the core) In other words, the circumferential measurement result of Qs is shown in Fig. 4 as the structural core of the blast furnace 0 (o + o) The coordinates ('Xl, Yt), (X4Y
28...Find (x i + yl). Furthermore, the circle closest to each of these coordinates (xi, yi) (in the figure,
The equation (indicated by the broken line) is written as the following equation (3) using the so-called least squares method, and the center of the circle is determined as the coordinates (a, b).

x" + 72-2ax -2by-C=O...
(3) (Method of displaying the circumferential direction measurement result of Qs as an n polygon and finding the center of gravity of the polygon) For example, if the circumferential direction measurement result of Qs is the structural core of the blast furnace 0 (0*0) If the vector is expressed as a hexagon as shown in Figure 5, the center of gravity 8 (x a * y a ) can be found by dividing the hexagon into triangles and dividing the hexagon into triangles. aft the top of the face
The coordinates of the three vertices are (X1i+3'11)t(xi
z+)'121L(XisiYis), it can be determined by the equation (4) below as well as the moment equation.

(2) The thermal center or thermal center of gravity for each level determined by the calculation in (1) above is m in the horizontal direction at each level.
Thermal core: i.e. the center of the circle (ai, bi) or (
As an example, the center of gravity [(xo)t+(yo)i) of the n polygon for each level determined by the method of b) is taken as an example, with the structural core 0 of the blast furnace as a pole, as shown in Figure 6. It is expressed in polar coordinates (ri, (lJi)).

(3) Understand the vertical distribution of the horizontal thermal core at each level determined in (2) above: In other words, the horizontal thermal core (
Since the horizontal cores (hereinafter simply referred to as horizontal cores) differ in two variables (r direction and θ direction), a line connecting these horizontal cores has a complicated profile in the vertical direction. Therefore, in order to understand the straightness of the thermal core in the vertical direction, it can be understood that the following procedure can be used.

By the way, there are various ways to understand the straightness of a profile made up of two variables, but as an example, an approximation method will be explained below. The idea is to project the above profile onto the r-Z plane and the 0-2 plane and approximate each with a straight line, and then combine this approximated curve with the horizontal reactor core (ri, a) at each level.
i), and evaluate the straightness of the profile based on the degree of the average value. That is, as a method of expressing the equation of the approximate straight line shown by the broken line in FIG. The n pieces of ri and θi data projected onto a plane are each calculated by the least squares method as shown in equation (5) below.

The distance between the approximate straight line given by equation (5) and the horizontal core (ri, θi) at each level is expressed as the length of one side MN of the triangle OMN in Figure 7, and is given by the following equation. .

The straightness of the thermal core in the vertical direction can be determined based on the numerical value given.

(4) Estimate the current thermal core deviation from the straightness determined in (3) above and the horizontal core determined in (2) above: However, for the horizontal core, the structural core of the blast furnace 0 (o + o)
It is also necessary to consider the deviation from the horizontal core r1+r determined for each level by the force formula
The average value of 2+...ri,...rn is adopted as the deviation from the structural core (Δbia).

Thus, from the above equations (6) and (7), Δ4i
If we make the following judgments from the numerical relationships between n and Δbia, we can be confident that the overall thermal core position can be estimated. That is, the numerical relationship between Akin and Δbia can be roughly classified into four groups indicated by the regions (■ to ■) within the broken lines in FIG. Therefore, if the numerical relationship between Δ7in and Δbia belongs to group 0, it can be seen that the horizontal deviation from the structural core is small because the value of horizontal core r is small, and the vertical straightness is small. Good (Δ7in
It is possible to understand that the current thermal core position of the entire blast furnace has a large deviation in the direction of the solid line in Figure 9 and good vertical straightness. It can be estimated that the thermal core position at this time is in the state shown by the solid line ■ in the figure. Also Δlin and Δb
If the numerical relationship of ia belongs to the 0 group, it can be understood that the amount of horizontal deviation is small and the vertical straightness is not good, and the thermal core position at this time is indicated by the broken line ■ in the figure.
It can be estimated that the situation is as shown in . Furthermore, Δlin
If the numerical relationship between It can be estimated that the situation is as shown. Furthermore, by displaying FIGS. 8 and 9 on a CRT screen, it becomes possible to monitor the thermal core status from time to time.

It should be noted that the above embodiments are merely representative examples and do not limit the present invention. It goes without saying that it is within the technical scope of the present invention to carry out the invention with appropriate changes within the scope of the present invention.

For example, you are free to change the temperature sensor's size, type 1ITt, number of sensors, etc. as appropriate. Furthermore, in the above explanation, the main focus was placed on blast furnaces as vertical furnaces, but it goes without saying that this is not the only option. , and can be particularly well applied to high-temperature vertical furnaces.

Since the present invention is configured as described above, the thermal core position from the upper part of the tuyere to the reactor mouth can be estimated and grasped accurately over a long period of time in the horizontal and vertical directions, and reactor operation management can be performed more accurately. This makes it possible to further contribute to ensuring long-term stability of reactor conditions.

[Brief explanation of the drawing]

Figure 1 (a) is a schematic explanatory diagram when the method of the present invention is applied to a blast furnace, Figure 1 (b) is an enlarged view of part b of Figure 1 (a), and Figure 2 is a diagram showing the method of the present invention applied to a blast furnace. FIG. 3 is a partially cutaway perspective view of the temperature sensor used for this purpose, FIG. 3 is a developed cross-sectional view equivalent to FIG. 2, FIGS. Figures 8 and 9 are explanatory diagrams of the estimated relationship between the analysis results and the thermal core position. B...Temperature sensor W...Fireproof wall P, ~P6...
・Temperature Sensing Part Applicant: Kobe Seishusho Co., Ltd.

Claims (1)

[Claims] An appropriate number of temperature sensors that have two or more temperature sensing parts in the wall thickness direction and detect temperatures at different positions in the wall thickness direction are embedded in the circumferential direction and height direction in the refractory wall of the vertical furnace. , while determining the thermal core in the horizontal direction of the vertical furnace by determining the thermal center inside the furnace from the temperature information group obtained by each temperature sensor,
The horizontal thermal cores are determined at different vertical positions of the vertical reactor, and the vertical distribution of each of these horizontal thermal cores is determined, and from the horizontal thermal core and its vertical distribution, the current position is determined. A method for estimating the thermal core position of a vertical reactor, characterized by estimating the thermal core position at .