JPS59225285A - Method of cooling inside of fire proofing wall - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling method within a refractory wall, and in particular to internal cooling of the refractory wall itself (hereinafter simply referred to as furnace body cooling), and to improve the cooling efficiency in the wall thickness direction and the heat flow on the shell side. The present invention relates to an economical cooling method in which the amount of cooling liquid can be appropriately controlled by monitoring the relative relationship between levels.

Although the present invention is applicable to cooling the furnace body of any high-temperature furnace whose interior cannot be viewed directly, the following description will typically refer to the case where it is applied to a blast furnace.

It is no exaggeration to say that the lifespan of a blast furnace is largely determined by the quality of the furnace body cooling, and for this reason, furnace body cooling is generally always managed in a state that is a little too safe. In other words, when cooling the furnace body, multiple units are inserted into the fireproof wall in a staggered manner.
While water is supplied and circulated in the cooling channels arranged, the temperature of the water in the cooling channels located on the discharge side and outside the fireproof wall is measured, or the temperature inside the furnace wall is measured, and the supply side A control method is adopted that adjusts the amount of water. When implementing this control system, the minimum standard is to ensure that water flow is sufficient to achieve a sufficient cooling effect even when the heat load inside the furnace is at its highest. However, the actual heat load in the furnace constantly fluctuates, and when viewed over time, it can be seen that the phenomenon of local weakening of this heat load occurs frequently. Therefore, the cooling inside the fireproof wall, which corresponds to the area where the heat load inside the furnace is reduced, becomes even more excessive, and the reality is that cooling water is wasted unnecessarily. From this point of view, there has been a strong demand to conserve the cooling water used for cooling the reactor body in line with the demand for energy conservation.

The present invention was made with a focus on the above-mentioned circumstances, and its purpose is to grasp the cooling channels in the fireproof wall in units of blocks, and to analyze the state of heat transfer in the wall thickness direction for each block (i.e., to The heat flow through the reactor and the amount of heat removed into the cooling channel) are directly measured, and the water cooling dust in each block is controlled based on the measured values, and the supply amount of cooling water used for cooling the reactor body is appropriately controlled. The object of the present invention is to provide a cooling method that can be used.

However, the cooling method of the present invention that has achieved the above object is that when cooling the fireproof wall by embedding the coolant passage in the fireproof wall, A detection sensor having at least three or more temperature-sensing parts is buried in the thickness direction of the wall, and the heat flux information obtained by the sensor is used to determine the relative relationship between the cooling efficiency in the wall thickness direction and the heat flow level on the skin side. The gist is that the supply amount of the cooling liquid is adjusted while being monitored.

The configuration and effects of the present invention will be explained below with reference to the drawings. As described above, the present invention aims to directly capture the movement of heat inside the fireproof wall, that is, the heat flux (hereinafter simply referred to as heat flow), and control the amount of cooling water for each block (or it can also be called distributed control) according to the degree of the movement. To do so, it was necessary to consider the heat flow situation within the fireproof wall. That is, FIG. 1 is a schematic diagram of the main part showing the heat flow situation within the fireproof wall W.

As shown in this figure, the heat flows within the fireproof wall W between adjacent cooling water passages 1.1 are those directed toward each cooling water passage 1 (heat flows indicated by arrows Qa l Qb l... (arrow Q'
a+Q'b+...Q10 heat flow).

Therefore, in order to control the amount of cooling water flowing through the cooling water passage 1, it is essentially the most direct way to grasp the change in the Qa-Qe heat flow over time. However, the actual direction of the Qa-Qe heat flow is not as simple as shown in the schematic diagram, but is extremely complex, so it is extremely difficult to directly capture the Qa-Qe heat flow. there were. But Q'
Since the heat flow in r barrel 'e is a uniaxial heat flow, it has the advantage that it is easy to collect thermal information, that is, measure it.Moreover, Q'a
The amount of decrease in heat flow (-ΔQ') of ~Q'e is naturally Q a
-QeO It should correspond to the increase in heat flow (+ΔQ), so as a result of further investigation on this point, we found the following (
It was confirmed that the technical causal relationships shown in equations 1-1) and (1-2) almost hold true.

, 5f(Q'e)f(ηq')ζf(η9)...
・(1-2) However, Δt: minute time Q10: uniaxial heat flow ηQ dissipating from the steel shell means indirect cooling efficiency by cooling water, ηQ: means direct cooling efficiency by cooling water, that is, (i =2) Formula is the indirect cooling efficiency, that is, the cooling efficiency in the wall thickness direction η9I, and the skin side level (
By simultaneously grasping the relative relationship of Q'H (hereinafter referred to as the heat flow level on the shell side), Qa toward the cooling water passage 1
-Qe can be approximated as a change in heat flow over time f(ηQ).

Therefore, the present inventors used a detection sensor that can reliably measure the above-mentioned cooling efficiency ηQ/ and shell side heat flow level Q/e, and conducted cooling while monitoring the relative relationship between ηQ/ and Q'e as shown below. They were able to adopt a method of adjusting the amount of water supplied. This monitoring and adjustment of the amount of cooling water supplied may be carried out according to the basic procedures (a) to (a) below.

(a) When ηQ' is high and Q10 is also high: Increase the amount of cooling water appropriately.

(b) When η91 is high and Q10 is low: The amount of cooling water is significantly reduced.

(c) When ηQ/ is low and Q10 is high: Largely increase the amount of cooling water.

b) When ηQ/ is low and Q10 is also low: The amount of cooling water is maintained as it is.

Comparing the total cooling water supply range when this cooling water amount adjustment method is implemented in one block with the same range when using the conventional method, the energization results are as shown in Table 4.

(+) is a normal increase 1 (1000) → (+110)
indicates that the degree of increase is even more significant.

(→ indicates a decrease in I, and <--> indicates a greater degree of decrease.

(0) indicates that the status quo will be maintained.

As is clear from the results in Table 1, it can be seen that by implementing the method of the present invention, the amount of cooling water can be saved on a block basis by 25 to 75 times compared to the conventional method, and on average about 50%. Therefore, in the present invention, it is clear that the more the number of cooling water controls for each block is increased, the more the running cost can be reduced by significantly saving the amount of cooling water even after subtracting the increase in control cost.

By the way, the detection sensor for measuring ηQ' and Q'e mentioned above may be of any type or structure as long as it can measure at least Q'a and Q10. Of course, it must have three or more temperature sensing parts. This is because two temperature-sensing parts can detect only one heat sink.

A preferred example of such a detection sensor and an example of its application will be described below. That is, FIG. 2 shows a partially cutaway perspective view of a preferred sensor (temperature detection sensor) 20, and FIG. 3 shows a developed cross-sectional view corresponding to FIG. 2. In these figures, reference numeral 21 denotes an outer sheath tube which serves as a protector for the entire temperature detection sensor 2o. 22a is a sheath type thermocouple, and a pair of metal wires 24, 24' exhibiting a thermoelectric effect are inserted through the thermocouple 22a, and the tips of the metal wires 24, 24' are located within the sheath as measurement contacts, that is, temperature sensing portions PI, P2. . . . constitutes P6 (hereinafter referred to as P when speaking representatively).

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 (side A) to the side of the steel shell (side B).
PL, P2, . . . P6 are provided by changing the positions in the length direction at approximately equal pitches toward the side). Further, a sheathed thermocouple 22d made of the same material as the sheathed thermocouple 22a is connected as a dummy to the tip of the temperature sensitive part P (26 in the figure indicates a connection part). Reference numeral 23 denotes a fire-resistant insulating material filled in the outer sheath tube 21, which has a thermal conductivity suitable for the fire-resistant wall characteristics in order to suppress the influence of thermal disturbances as much as possible. Therefore, it can be said that the temperature measurement performance of each temperature sensing part P in such a temperature detection sensor 2o is sufficiently reliable in terms of accuracy and durability.

When installing this temperature detection sensor 20 on a fireproof wall, please refer to Fig. 4 (schematic sectional view when the method of the present invention is carried out in units of minimum blocks) and Fig. 5 (schematic front view thereof).
This can be done as shown in.

That is, xa*xb+tc++a (hereinafter simply referred to as 1 when speaking representatively) indicates cooling water passages, which are arranged in plurality in a substantially staggered manner inside the fireproof wall W (in the figure, they are arranged at substantially diagonal positions). (installed) state. The three cooling water passages 1a to 1d shown in the figure constitute a minimum unit cooling block.

The temperature detection sensor 20 may be buried approximately in the center of the cooling block so as to penetrate through the iron skin 3 and the stamp layer 4 deep into the fireproof wall W so as to be approximately parallel to each cooling water passage 1. Reference numeral 5 denotes a heat flow calculation indicator provided outside the blast furnace, and within the indicator 5, Q10 (furnace heat flow level) lQ'5 (shell side heat flow level) and ηQ/ (cooling efficiency) is calculated as shown in equations (3) to (5), respectively.

λ Q' i −1(Ti −T j) ・・・・・・
...(2) i However, the subscript j means the i-th and j-th parts counting from the inside of the furnace, and the heat flow axis Vm2 between the Q'lji-th temperature sensing part and the j-th temperature sensing part
・h) Ti: Temperature measurement value at the i-th temperature sensing part (°C) Tj: Temperature measurement value at the i-th temperature sensing part (°C) DI Distance between the i-th temperature sensing part and the j-th temperature sensing part (h) )λ:
Thermal conductivity of the sensor 20 (kal/m-hr ・'C
) The thus calculated ηQ/ and Q10 are sent to the comparison setting indicator 6. In the setting indicator 6, the relative relationship between ηQ/ and Q'5 is monitored according to the criteria (a) to (a) as described above, and a predetermined control amount is set and instructed, and the cooling water is output as a constant signal. Supply system (arrow line L in the diagram)
It is transmitted to the pulp 8 on the root side. As a result, the pulp 8
opens and closes according to instructions. In this way, even if only the smallest cooling block is used, it is possible to supply the necessary and sufficient amount of cooling water according to the heat load inside the fireproof wall, which is extremely economical and contributes to energy savings. You can make a big contribution.

The above-mentioned embodiments are merely representative examples and do not limit the present invention, and it is within the technical scope of the present invention to implement the invention with appropriate modifications within the scope of the above-mentioned spirit. Needless to say.

For example, a cooling box system and a so-called stave system can be considered as cooling water passages, but it is possible to apply to both.
Furthermore, the cooling blocks can be divided freely, and a temperature detection sensor may be provided for each cooling block. Further, the sensor is not limited to a buried type, but may be a type that protrudes into the furnace.

Furthermore, in the above explanation, the main focus was on cooling inside the refractory wall of a blast furnace, but it goes without saying that this is not limited to this, but as stated at the beginning, in short, it is suitable for cooling the furnace body of any high-temperature furnace where the inside cannot be seen directly. Of course, the cooling liquid is not limited to water.

Since the present invention is configured as described above, it is possible to directly measure the state of heat transfer within the fireproof wall in blocks, and to perform cooling control for each hook based on the obtained measurement values. Ta. As a result, in response to a local increase or decrease in the heat load in the furnace, the supply core of the coolant can be adjusted to the extent necessary and sufficient to cool the refractory wall corresponding to that location, which reduces running costs. It has become possible to contribute to the reduction of energy consumption and the realization of energy conservation.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of the main parts showing the heat flow situation within the fireproof wall, Fig. 2 is a partially cutaway perspective view of a detection sensor suitable for carrying out the method of the present invention, and Fig. 3 is an exploded cross-sectional view equivalent to Fig. 2. , FIG. 4 is a schematic cross-sectional explanatory view when the method of the present invention is carried out in units of minimum blocks, and FIG. 5 is a schematic explanatory front view of the same. W...Fireproof wall 1 (1allblIC116)...Cooling liquid passage 20
...Detection sensor applicant Kobe Steel, Ltd. 21S1 Port 1 Figure 3

Claims (1)

[Claims] When cooling the fireproof wall by embedding a cooling liquid passage in the fireproof wall, a detection sensor having three or more temperature sensing parts is buried in the vicinity of the cooling liquid passage in the thickness direction of the fireproof wall, A method for cooling inside a fireproof wall, comprising: adjusting the amount of forced circulation of the coolant using heat flux information obtained from a detection sensor.