JPH0726135B2 - Hot stove temperature control device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a temperature control device for a hot stove that lowers the average temperature of the hot stove when feeding the temperature and air volume required by the blast furnace. Is.

[Prior Art] In order to efficiently carry out the reducing action in a blast furnace, a predetermined temperature and a predetermined amount of hot air are required.

A hot-air stove is used to supply hot air to the blast furnace.

As shown in FIG. 3, the hot stove has a heat storage body 2 inside a furnace body 1 and the on-off valves 3c and 3d with the on-off valves 3a and 3b closed.
Is opened and the combustion air 5 and the fuel gas 5 ′ are fed while being burned by the burner 4, when the combustion gas passes through the heat storage body 2, the heat storage body 2 is heated and heat is stored, and the heat storage body 2 has a predetermined temperature. When the temperature becomes higher than the temperature, the on-off valves 3c and 3d are closed to stop the combustion of the burner 4, the supply of the air 5 to stop the heat accumulation, and the on-off valve 3
This is for heating air in the process of passing the heat storage body 2 by opening a and 3b and passing the heat storage body 2, and sending the generated hot air to a blast furnace (not shown).

Normally, a plurality of hot blast stoves are provided for one blast furnace facility. When one is in a hot air supply state, the rest is in a heat storage state, and hot air is sent by alternately repeating the heat storage state and the hot air supply state. I have to.

[Problems to be Solved by the Invention] The above-described conventional hot air supply facility has a system in which the supply of hot air from one hot air stove is completed and then the blowing of air from another hot air stove is started.

For this reason, the hot air temperature at the end of hot air feeding from the hot air stove must be the target temperature required by the blast furnace, and the average temperature (maximum temperature) of the hot air stove becomes high, which causes the damage to the heat storage body (brick) earlier. is there.

In view of such circumstances, the present invention aims to reduce the average temperature of the hot stove.

[Means for Solving Problems] In the present invention, four hot stoves whose heat storage state is controlled by a combustion controller are installed, and the first hot stove to the fourth hot stove, and further to the first hot stove. It circulates sequentially and blows air by overlapping the blowing condition within a range of 2/3 or less, and at least one hot stove is used for heat storage operation, and the blowing temperature is detected in each of the first hot stove and the second hot stove. First and second temperature deviation calculators, which are provided corresponding to both temperature detectors and which obtain a deviation between a detection result from both temperature detectors and a target value, Based on the calculation result from the temperature deviation calculator, a calculator for instructing the third combustion controller of the hot stove the corrected combustion amount, and based on the calculation results from the first and second temperature deviation calculators, a fourth calculator The burner controller of the hot blast stove, and the correction controller for the first and second hot blast stoves. It is characterized in that it is equipped with an arithmetic unit for instructing the positive combustion amount.

[Operation] In the present invention, the air blowing by each hot air stove is performed while being sequentially overlapped, and at this time, the air blowing temperature of the first hot air stove and the air blowing temperature of the second hot air stove are the first and second temperature detectors. The deviation between the detection result and the target value is detected by the first and second
The corrected combustion amount is instructed from the calculator to the combustion controller of the third hot stove based on the calculation result from the first temperature deviation calculator, and the first and second temperature deviations are calculated. Based on the calculation result from the arithmetic unit, the arithmetic unit instructs the combustion controller of the fourth hot stove to specify the corrected combustion amount, and the combustion controllers of the first and second hot stoves also indicate the corrected combustion amount. Due to
The blowing temperature of the hot stove is controlled to the target value.

In this way, since the hot air blower in the previous stage and the hot air blower in the next stage are sequentially overlapped, the hot air sent to the blast furnace has a low temperature hot air in the previous stage and a high temperature hot in the next stage. It becomes a mixture of hot air and hot air with an averaged temperature. Therefore, the hot air at the previous stage may be a hot air having a temperature lower than the required temperature of the blast furnace, and the temperature difference between the temperature of the hot air fed and the required temperature of the blast furnace is reduced.

[Examples] Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a system explanatory view of the present invention, in which 7 is a first hot stove, 8 is a second hot stove, 9 is a third hot stove, 10 is a fourth hot stove, and 11 is a first hot stove. Combustion controller, 12 is a second hot stove combustion controller, 13 is a third hot stove combustion controller, 14 is a fourth hot stove combustion controller, 15,16,17,18,19,20,21 , 22 are opening / closing valves provided in the ventilation passages 23,24,25,26, 27 is a blower, and 28,29
Indicates a temperature detector provided in the ventilation paths 23, 24. It should be noted that in the figure, the supply and discharge passages for the combustion gas are omitted.

First, the hot air supply system in this embodiment will be described.

As shown in FIG. 2, the on-off valves 15 and 19 are opened to open the first hot stove 7
Opening valve starts when more air is blown and half blows
16 and 20 are opened to start blowing air from the second hot stove 8. Therefore, the temperature of the hot air that is actually sent is the same as that of the first hot air stove 7 and the second hot air stove 7.
The temperature is a temperature at which the hot air from the hot air oven 8 is mixed.

Furthermore, the first half of the blow of the third hot stove 9 is overlapped with the latter half of the blow of the second hot stove 8 and the opening / closing valves 15, 19 are closed.
The blast of the hot blast stoves 7 is stopped, and the blast of the hot blast stoves and the stop heat storage are performed while sequentially overlapping the first half of the blast of the third hot blast stoves 9 so as to overlap the latter half of the blast of the fourth hot blast stoves 10.

When hot air is fed in this way, the hot air temperature of the hot air stove that is blowing is considerably lower than the temperature required by the blast furnace, but the temperature of the hot air from the next hot air stove that has been overlapped by that amount Therefore, the temperature of the mixed hot air satisfies the required temperature of the blast furnace.

Furthermore, since the hot air temperature when the blowing of the hot air stove is stopped can be made lower than the required temperature of the blast furnace, the average temperature (maximum temperature) of the hot air stove can be lowered.

Thus, as described above, the control is performed as follows so that the temperature of the mixed hot air when overlapped is constantly maintained at a desired temperature.

In FIG. 1, 30 is a temperature deviation calculator, 31 is a target value setter, 32 is a temperature deviation calculator, 33 is a target value setter, 34, 35, 36
Indicates an arithmetic unit.

The target value setters 31, 33 set and input the target temperature Ts at the intermediate point of hot air blowing from the first hot stove 7 and the second hot stove 8 to the temperature deviation calculators 30, 32. Further, the temperature detectors 28 and 29 input the temperature of hot air at the midpoint of blowing air to the temperature deviation calculators 30 and 32, respectively.

The temperature of the hot air sent to the blast furnace affects each other because the hot air stoves of the two hot air ovens constantly overlap and blow each other, so the correction must be made with consideration of the effect.

First, the fuel combustion amount Q of the first hot stove 7 and the second hot stove 8 is determined so that the hot air temperature T _M1 at the air blowing intermediate point of the first hot stove 7 is slightly lower than the target temperature Ts. Stores 7,8 heat.

When air is blown from the first hot blast stove 7, the temperature at the midpoint
T _M1 is lower than the target temperature Ts, and the temperature difference is ΔT ₁ (= Ts−T
_M1 ). The temperature difference ΔT ₁ is calculated by the temperature deviation calculator 30, and the result is input to the calculators 34 and 36. The air blowing from the second hot stove 8 is started, and the intermediate temperature T _M2 is detected by the temperature detector 29 and input to the temperature deviation calculator 32.
The intermediate temperature T _M2 of the hot air from the second hot stove 8 is the first hot stove 7
The temperature will be lower than the intermediate temperature T _M1 due to the influence of hot air.

The temperature difference ΔT _{2 with} respect to the target temperature of the intermediate temperature of the air blown from the second hot stove 8 is Ts−T _M2 .

Further, the arithmetic unit 34 calculates the temperature deviation ΔT ₁ from the temperature deviation ΔT _1.
Is calculated and the signal is input to the combustion controller 13. In the third hot stove 9, αΔT ₁ (α is a proportional constant and is determined in consideration of the hot stove capacity, fuel type, burner performance, etc.) with respect to the fuel combustion amount in the first hot stove 7. Only increase and store heat. The hot air intermediate temperature T _M3 from the third hot stove 9 is corrected by ΔT ₁ minutes with respect to Q, but is influenced by the hot air from the second hot stove 8 and ΔT ₃ (= ΔT ₂
There is still a temperature difference of −ΔT ₁ ).

The calculation result ΔT ₂ from the temperature deviation calculator 32 and the calculation result ΔT ₁ from the temperature deviation calculator 30 are input to the calculator 36, and the temperature deviation ΔT ₃ and the temperature deviation ΔT _{3 with} respect to the target value Ts are input.
The correction fuel amount ArufaderutaT ₃ is computed for T _3, the operation result [Delta] T ₃
Is input to the calculator 35, and αΔT ₃ is input to the combustion controller 14. The fourth hot blast stove 10 stores heat by the amount of fuel of Q + αΔT ₃ .
The corrected intermediate temperature T _M4 of the hot air from the fourth hot stove 10 can be matched with the target temperature Ts.

Next, in the correction of the fuel combustion amount after the first hot blast stove in the next cycle, the hot air temperature of the air blow in the previous stage is in a desired state, and it is not necessary to consider the temperature decrease due to the hot air in the previous stage.

Therefore, the corrected fuel amount is αΔT _3/2. This calculation is performed by the calculator 35, and the combustion controller
11, 12 heat storage corresponding to the fuel amount of the driving and Q + αΔT _3/2 is performed.

By this modification, if the blast intermediate temperature T _M1 of the first hot blast stove and the blast intermediate temperature T _M2 of the second hot blast stove match the target value Ts,
Longer correction is not required, the operation of the heat storage and hot air blower according to the amount of fuel Q + αΔT _3/2 is performed.

If the intermediate temperatures T _M1 and T _M2 do not match the target value, the correction operation is performed in the process described above, and eventually T _M1 and T _M2
Converge on Ts.

As described above, if hot air is blown, the air blowing temperature is averaged, and the exhaust air blowing temperature from each hot air stove when the air blowing is stopped can be made lower than the target value (blast furnace required temperature) (that is, the hot air stove maximum temperature is kept low. be able to.).

In the above embodiment, the overlap amount was halved by the four hot air stoves, but it is needless to say that the overlap amount may be 2/3 or less.

Further, in the above embodiment, the configuration corresponding to the functions such as the deviation calculator and the calculator is shown separately, but it goes without saying that each function included in one circuit may be shown.

[Advantages of the Invention] As described above, according to the present invention, the temperature of the mixed hot air when the hot air blower in the previous stage and the hot air blower in the next stage are sequentially overlapped with each other becomes a desired temperature constantly. Since the maximum temperature of the hot-air stove can be kept low, damage to the heat storage body is reduced and the life can be extended.
Also, the temperature difference between when hot air is blown and when it is stopped is reduced,
It has excellent effects such as eliminating waste of fuel.

[Brief description of drawings]

FIG. 1 is a block diagram of a preferable apparatus for carrying out the present invention, FIG. 2 is an operation explanatory view of the present invention, and FIG. 3 is an explanatory view of a conventional example. 7,8,9,10 are hot stoves, 11,12,13,14 are combustion controllers, 28,29 are temperature detectors, 30 and 32 are temperature deviation calculators, and 34,35 and 36 are calculators. .

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shuichi Yoshii 2-2-1 Otemachi, Chiyoda-ku, Tokyo Ishi Kawashima Harima Heavy Industries Co., Ltd. (56) Reference JP-A-59-126703 (JP, A)

Claims (1)

[Claims] 1. Four hot blast stoves whose heat storage state is controlled by a combustion controller are installed, and the hot blast stoves are sequentially circulated from the first hot blast stove to the fourth hot blast stove and further to the first hot blast stove, and the blowing condition is 2 /. At least one hot blast stove is provided for overlapping heat in the range of 3 or less and the first hot blast stove and the second hot blast stove are respectively provided with first and second temperature detectors for detecting blast temperature. First and second determinations are provided corresponding to both temperature detectors to obtain a deviation between a detection result from both temperature detectors and a target value.
From the temperature deviation calculator and the first temperature deviation calculator, a calculator for instructing the combustion controller of the third hot-blast stove the corrected combustion amount based on the calculation result, and from the first and second temperature deviation calculators And a calculation unit for instructing the combustion controller of the fourth hot-blast stove to instruct the corrected combustion amount and the combustion controllers of the first and second hot-blast stoves to instruct the corrected combustion amount. And a hot-air stove temperature control device.