JP2011219804A - Hot blast stove control and computing device, method for controlling hot blast stove, and computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot blast stove control and computing device capable of flexibly controlling an operation of a hot blast stove to continue the operation by suppressing a decrease in thermal efficiency as much as possible in the hot blast stove, even when there is a need to suddenly reduce a heating value of hot blast from the first schedule, the hot blast being supplied from the hot blast stove in a staggered parallel operation to a blast furnace.SOLUTION: A hot blast stove control and computing device 301 includes: means 503a, b, c, d for computing a necessary charged heating value; a means for computing a present charged heating value; a means for computing a present blast heating value; a means for computing a present thermal efficiency value; a means for setting a reference value; a means for determining air reduction and temperature reduction; a means for determining deterioration in thermal efficiency; and a means 505 for computing a correction coefficient of a charged heating value. A charged heating value to the hot blast stove is computed by multiplying the necessary charged heating value computed by the means 503a, b, c, d for computing a necessary charged heating value by the correction coefficient of a charged heating value, the correction coefficient being computed by the means 505 for computing a correction coefficient of a charged heating value.

Description

  The present invention relates to a hot stove control calculation device, a hot stove control method, and a computer program, and is particularly suitable for setting the amount of heat input to the hot stove when the amount of hot air supplied from the hot stove to the blast furnace decreases. It is a thing.

A hot blast furnace is attached to the blast furnace in order to supply hot blast to the steel industry blast furnace. The hot stove generates hot air by heat exchange with the heat storage brick through the combustion period in which the heat storage brick is heated by the combustion gas to store heat based on the blowing conditions required from the blast furnace, and is supplied to the blast furnace The hot air is supplied to the blast furnace by alternately repeating the blowing period.
At present, a plurality of (for example, four) hot blast furnaces are connected in parallel to one blast furnace, and the plurality of hot blast furnaces are generally operated in a staggered parallel system. The staggered parallel method is a method of wrapping at least a part of two air blowing periods that move back and forth in the order of supplying hot air.

In the hot blast furnace, hot blast that satisfies the blowing conditions required from the blast furnace must be supplied to the blast furnace. For this reason, it is a matter of course that the amount of heat input to the hot stove is set so that the heat storage amount of the hot stove does not become insufficient, but within a range that satisfies the blowing conditions required from the blast furnace so that the thermal efficiency of the hot stove does not decrease. It is desirable to reduce the amount of heat input to the hot stove as much as possible. In general, the scale of a hot stove is large, and the control time constant is about 1 hour or more.
From such a viewpoint, there are techniques described in Patent Documents 1 and 2 as techniques for setting the input heat amount.

  In Patent Document 1, the amount of heat stored in the hot stove is expressed as a linear function of three temperature measurement values of the top, middle, and bottom of the heat storage chamber, and coefficients and constant terms are expressed by a statistical method such as regression analysis. I try to decide. Then, the amount of heat deprived from the hot stove at the time of the next blow is calculated and added to the target heat storage amount at the time of the next blow to obtain the heat storage amount at the start of the blow. Then, the difference between the heat storage amount at the present time and the heat storage amount at the start of blowing is determined as the input heat amount.

  Further, in Patent Document 2, the theoretical amount of heat release during the next blast condition requested from the blast furnace is obtained, the heat removal efficiency is obtained from the moving average of the actual heat balance of the hot blast furnace, and further corrected according to the operation of the hot blast furnace. Find the amount of heat. Then, the input heat quantity is obtained by dividing the value obtained by adding the correction heat quantity (or the subtracted value) to the ventilation period theoretical heat release quantity by the heat removal efficiency.

JP 55-79814 A JP-A-7-145416

By the way, when the operation in the blast furnace is reduced or the operation in the blast furnace is unstable, the amount of heat of the hot air supplied from the hot blast furnace to the blast furnace cannot be achieved as originally planned, and needs to be reduced ( In the following description, such “state in which the amount of heat of the hot air from the hot air furnace is reduced without being planned” is also referred to as “state of reduced wind and temperature”. In the operation, the operation is switched to the wind reduction / temperature reduction state by an instruction input from the operator.
In Patent Document 1, the amount of heat stored in the hot stove is obtained based on a statistical method such as regression calculation. For this reason, when the hot stove is in a state of reduced wind and reduced temperature, tuning such as a regression equation must be performed in accordance with the state. The state of temperature reduction and temperature reduction in the hot stove is not uniquely determined and is different each time, so it is difficult to perform such tuning accurately and quickly. Therefore, it is difficult to appropriately determine the amount of input heat when the hot stove is in a state of reduced wind and temperature, and as a result, there is a problem that the thermal efficiency of the hot stove may be reduced.

In addition, when operating a hot stove in the staggered parallel system, it is generally difficult to measure the flow rate of air for each furnace. Therefore, in the above-mentioned Patent Document 2, when the hot stove is in a state of reduced wind temperature reduction, an apportioned value of the entire blast heat quantity of the four hot stoves is adopted as the blast heat quantity (correction heat quantity) for each furnace. is doing. Therefore, it is difficult to appropriately determine the amount of input heat when the temperature is reduced and the temperature is reduced. As a result, there is a problem that the thermal efficiency of the hot stove may be reduced.
The present invention has been made in view of the above problems, and it is necessary to suddenly reduce the amount of heat of hot air supplied from a hot blast furnace operating in a staggered parallel system to the blast furnace from the initial schedule. It is an object of the present invention to be able to continue the operation of the hot stove flexibly by preventing the thermal efficiency of the hot stove from being lowered as much as possible.

  The hot stove control calculation apparatus of the present invention calculates the input heat amount to be input to each of the hot stoves in order to control the combustion and blowing of a plurality of hot stoves operated in a staggered parallel system. In each of the plurality of hot stoves, the required input heat amount in the next cycle of the operation of the hot stove is set to the heat balance related to the thermal efficiency of the hot stove before the combustion period in the next cycle. The required input heat amount calculation means for calculating using the actual value of the current, and the actual operation value of the combustion gas for performing the combustion are input, and the current value of the input heat amount for calculating the total input heat amount of the plurality of hot stove furnaces is calculated. A value calculation means, an actual operation value of hot air supplied from the hot stove to the blast furnace, and an actual operation value of cold air supplied to the hot stove, and A current value calculation unit for calculating a current value of the blown heat amount, a current value of the input heat amount, and a current value of the blown heat amount; When an operation for instructing the input device to correct the required input heat amount is performed by an operator, the current value of the input heat amount calculated by the input heat amount current value calculating means and the current amount of blast heat Reference value setting means for setting the current value of the blast heat quantity calculated by the value calculation means and the current value of the heat efficiency calculated by the current efficiency value calculation means as reference values, respectively, and the reference value setting means Decrease in determining whether the decrease in the current value of the blast heat quantity calculated by the blast heat quantity current value calculation means with respect to the reference value of the blast heat quantity exceeds the wind reduction / temperature reduction judgment value. Whether or not the decrease in the current value of the thermal efficiency calculated by the current thermal efficiency value calculation unit with respect to the reference value of the thermal efficiency set by the temperature reduction determination unit and the reference value setting unit exceeds the thermal efficiency decrease determination value It is determined by the thermal efficiency decrease determination means that determines the amount of decrease in the current value with respect to the reference value of the blown heat amount exceeds the reduced wind temperature decrease determination value, and the thermal efficiency decrease determination means When it is determined that the decrease in the current value with respect to the reference value of the thermal efficiency exceeds the thermal efficiency decrease determination value, the input heat amount correction coefficient calculating means for calculating the input heat amount correction coefficient and the necessary input heat amount calculating means are required. Multiplying the input heat amount by the input heat amount correction coefficient calculated by the input heat amount correction coefficient calculating means, the input heat amount in the next one cycle of each of the hot air furnaces is calculated. The input heat amount correction coefficient calculating means calculates the input heat amount correction coefficient A [−] by the following equation (A).

  The hot stove control method of the present invention is a hot stove control method for controlling the amount of heat input to each of a plurality of hot stoves operated in a staggered parallel system, and for each of the plurality of hot stoves, A required input heat amount calculation step of calculating the required input heat amount in the next one cycle of the operation of the furnace using the actual value of the heat balance related to the thermal efficiency of the hot stove furnace before the combustion period in the next one cycle; Input the actual operation value of the combustion gas for performing the combustion and calculate the current value of the input heat amount of the whole of the plurality of hot blast furnaces, and the hot air supplied from the hot blast furnace to the blast furnace The operation result value of the cooling air and the operation result value of the cold air supplied to the hot air furnace are input, and the current value calculation process for calculating the current value of the air supply heat amount of the whole of the plurality of hot air furnaces, and the input heat A current efficiency value calculation step of calculating a current value of the thermal efficiency of the entire plurality of hot stoves from the current value of the blast heat quantity and a correction of the required input heat quantity to the input device by an operator. When an operation for instructing to be performed is performed, the current value of the input heat amount calculated by the input heat amount current value calculation step, the current value of the blast heat amount calculated by the blast heat amount current value calculation step, and the A reference value setting step for setting the current value of the thermal efficiency calculated by the current thermal efficiency value calculation step as a reference value, and the current value calculation step for the blast heat amount with respect to the reference value of the blast heat amount set by the reference value setting step The decrease in the current value of the blast heat quantity calculated by the above is set by the wind reduction / temperature reduction determination step for determining whether or not the current reduction value exceeds the wind reduction / temperature reduction determination value and the reference value setting step. Thermal efficiency decrease determination step for determining whether a decrease in the current value of the thermal efficiency calculated by the thermal efficiency current value calculation step with respect to a reference value of thermal efficiency exceeds a thermal efficiency decrease determination value; and the wind reduction and temperature decrease determination It is determined by the process that the decrease in the current value with respect to the reference value of the blast heat quantity has exceeded the wind reduction and temperature reduction determination value, and the decrease in the current value with respect to the reference value of the thermal efficiency is determined as the decrease in thermal efficiency by the thermal efficiency decrease determination step When it is determined that the value has been exceeded, the input heat amount correction coefficient calculation step for calculating the input heat amount correction coefficient and the required input heat amount calculated by the necessary input heat amount calculation step are calculated by the input heat amount correction coefficient calculation step. Calculated in the input heat amount calculation step of multiplying the input heat amount correction coefficient to calculate the input heat amount in the next cycle of each of the plurality of hot stoves, and in the input heat amount calculation step And a flow rate adjusting step for adjusting the flow rate of the combustion gas supplied to the hot stove during the combustion period in the next one cycle based on the input heat amount, and the input heat amount correction coefficient calculating step includes the following (A ) To calculate the input heat amount correction coefficient A [−].

The computer program of the present invention causes the computer to calculate the amount of heat input to each of the hot stoves in order to control the combustion and blowing of a plurality of hot stoves operated in a staggered parallel system. A computer program for each of the plurality of hot stoves, the required input heat amount in the next one cycle of the operation of the hot stove before the combustion period in the next one cycle Enter the required input heat amount calculation process to calculate using the actual value of the heat balance related to thermal efficiency and the actual operation value of the combustion gas for performing the combustion, and calculate the current value of the input heat amount of the entire hot stove The input heat amount present value calculation process to be performed, the operation result value of hot air supplied from the hot stove to the blast furnace, and the operation result of cold air supplied to the hot air furnace And calculating the current value of the blast heat quantity of the entire plurality of hot stove furnaces, the current value of the blast heat quantity, the current value of the input heat quantity, and the current value of the blast heat quantity. When the current efficiency value calculation step for calculating the current value of the thermal efficiency of the entire furnace and an operation for instructing the input device to correct the required input heat amount are performed by the operator, the input heat amount current value The current value of the input heat quantity calculated by the calculation process, the current value of the blast heat quantity calculated by the current blast heat quantity calculation process, and the current value of the thermal efficiency calculated by the thermal efficiency current value calculation process are respectively reference values. A decrease in the current value of the blast heat amount calculated by the current value calculation step of the blast heat amount relative to the reference value of the blast heat amount set by the reference value setting step Is obtained by the present thermal efficiency current value calculating step with respect to the reference value of the thermal efficiency set by the reference value setting step, The decrease in the current value with respect to the reference value of the blast heat quantity is reduced by the heat efficiency decrease determination step for determining whether the decrease in the current value of the heat efficiency exceeds the heat efficiency decrease determination value and the wind reduction and temperature decrease determination step. When it is determined that the wind temperature reduction determination value has been exceeded, and it is determined in the thermal efficiency decrease determination step that the decrease in the current value with respect to the reference value of thermal efficiency has exceeded the thermal efficiency decrease determination value, an input heat amount correction coefficient is calculated. Multiplying the plurality of hot air by multiplying the required input heat amount calculated by the input heat amount correction coefficient calculation step and the required input heat amount calculation step by the input heat amount correction coefficient calculated by the input heat amount correction coefficient calculation step The input heat amount calculation step of calculating the input heat amount in the next one cycle of each furnace is executed by a computer, and the input heat amount correction coefficient calculation step is performed by the following equation (A) according to the input heat amount correction coefficient A [ −] Is calculated.
A = (Qouts / Qouts-0) x (Qins-0 / Qins) (A)
Here, Qouts [kcal / min] is the current value of the blast heat quantity, Qouts-0 [kcal / min] is the reference value of the blast heat quantity, and Qins-0 [kcal / min] The reference value of the input heat amount, Qins [kcal / min] is the current value of the input heat amount.

  According to the present invention, when there is a need for wind reduction and temperature reduction, the amount of hot air when viewed as a whole of a plurality of hot stove furnaces operating in a staggered parallel system after an instruction / input by the operator is Reduced and the thermal efficiency when viewed as a whole of the plurality of hot stoves is required so that the thermal efficiency when viewed as a whole of the plurality of hot stoves is the same as when an instruction is given by the operator The input heat amount correction coefficient for correcting the input heat amount is calculated. Therefore, even when the amount of hot air supplied from the hot stove operating in the staggered parallel system to the blast furnace is reduced, the thermal efficiency in the hot stove can be prevented from being lowered as much as possible.

It is a figure which shows an example of schematic structure of the hot stove to which embodiment of this invention is applied. It is a figure which shows an example of the outline | summary of the operation | movement of the combustion period and ventilation period in the hot stove to which embodiment of this invention is applied. It is a figure which shows an example of schematic structure of the control system of the hot stove to which embodiment of this invention is applied. It is a figure explaining an example of the outline of the operation schedule in a staggered parallel system. It is a block diagram which shows embodiment of this invention and shows an example of a functional structure of a hot stove control computer. It is a block diagram which shows embodiment of this invention and shows an example of a functional structure of an input heat amount correction coefficient calculating part. It is a figure which shows embodiment of this invention and illustrates the meaning of the input heat amount correction coefficient A. It is a flowchart which shows embodiment of this invention and demonstrates an example at the time of calculating | requiring the setting value of combustion gas flow volume. It is a flowchart which shows embodiment of this invention and illustrates an example of operation | movement of the input heat amount correction coefficient calculating part at the time of calculating the moving average value in the predetermined time of input heat amount. It is a flowchart which shows embodiment of this invention and demonstrates an example of operation | movement of the input heat amount correction coefficient calculating part at the time of calculating the moving average value in the predetermined time of blast heat amount. It is a flowchart which shows embodiment of this invention and demonstrates an example of operation | movement of the input heat amount correction coefficient calculating part at the time of calculating an input heat amount correction coefficient. It is a figure which shows embodiment of this invention and shows the result of the simulation showing the response of input heat amount, ventilation heat amount, and thermal efficiency when changing ventilation flow volume.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating an example of a schematic configuration of a hot stove 100. In each figure, for the convenience of explanation, only necessary portions are simplified as necessary.
In FIG. 1, a hot stove 100 is a regenerative heat exchanger for supplying hot air to a blast furnace (not shown), a regenerative chamber 101 that gives heat to blowing air to the blast furnace, and a combustion for heating the regenerative chamber 101. A chamber 102 and a mixed cooling chamber 103 for adjusting the temperature of hot air are provided.

  In the combustion chamber 102, a mixed gas (combustion gas) of BFG gas and COG gas blown from the gas supply duct 112 and combustion air blown from the combustion air supply duct 113 are burned by the combustion burner 108, and the combustion gas is stored as heat. Heat is stored by passing between the heat storage bricks stacked inside the chamber 101.

In the example shown in FIG. 1, as this heat storage brick, a high alumina brick 109 and a silica brick 111 mainly composed of silica are laminated in order from the bottom, and the high alumina brick 109 and the quartz brick 111 are A plurality of passage openings extending in the vertical direction are formed. In detail, heat storage bricks generally have a three-layer structure of clay bricks, high alumina bricks, and quartz bricks in order from the bottom, but for the sake of simplicity, the hot stove is of the above structure. It will be explained as being.
The gas supply duct 112 is provided with a gas cutoff valve 130, a gas butterfly valve 131, and a combustion gas flow meter 132, and an inflow amount of combustion gas flowing into the combustion chamber 102 by opening and closing the gas butterfly valve 131. Can be adjusted.

The combustion air supply duct 113 sends the air blown from the combustion air fan to the hot stove 100.
The combustion air supply duct 113 is provided with an air flow meter 127, an air butterfly valve 128, and an air shut-off valve 129. An amount of air necessary for combustion is introduced into the combustion air supply duct 113 in accordance with the flow rate of the combustion gas.
A duct 114 is provided at the lower end of the heat storage chamber 101, and this duct 114 has a gas discharge duct 119 for discharging combustion gas containing N ₂ , CO _2, etc., and a heat storage chamber via the duct 114. Branched into a cold air introduction duct 116 for supplying cold air to 101.
The gas exhaust duct 119 is provided with a flue valve 126.

The cold air introduction duct 116 is provided with a blower valve 124 and a blower butterfly valve 125, and by opening and closing the blower butterfly valve 125, the inflow amount of the cold wind flowing into the hot air furnace 100 can be adjusted.
The mixed cooling chamber 103 is connected to a hot air discharge duct 117 for discharging hot air for the blast furnace. The hot air discharge duct 117 is provided with a hot air valve 121.
In addition, a duct 118 connected to the mixed cooling chamber 103 is provided on the upstream side of the air blowing butterfly valve 125 of the cold air introduction duct 116. The duct 118 is provided with a cold air valve 122 and a cold air butterfly valve 123.

FIG. 2 is a diagram illustrating an example of an outline of operations in the combustion period and the blowing period in the hot stove 100. In the following description, BFG gas and COG gas are collectively referred to as “combustion gas”.
As shown in FIG. 2A, when heat is stored in the heat storage chamber 101 during the combustion period, the air supply valve 124, the cold air valve 122, and the hot air valve 121 are completely closed, and the gas supply duct 112 and the combustion air Combustion gas and combustion air are introduced into the combustion chamber 102 via the supply duct 113.
These combustion gases and combustion air are burned by the burner 108, and the combustion gases store heat in the high alumina brick 109 and the quartz brick 111 through the openings formed in the high alumina brick 109 and the quartz brick 111 in the heat storage chamber 101. . The combustion gas that has passed through the high alumina brick 109 and the quartz brick 111 is discharged to the flue as exhaust gas through the gas discharge duct 119.

  When the heat storage in the heat storage chamber 101 is completed, as shown in FIG. 2B, the flue valve 126, the air shut-off valve 129, and the gas shut-off valve 130 are completely closed, and the heat storage chamber is connected via the cold air introduction duct 116. Cold air is caused to flow into 101. The cold air that has flowed into the heat storage chamber 101 passes through openings formed in the high alumina brick 109 and the quartz brick 111 and is heated to 900 to 1300 ° C., and then is discharged from the hot air discharge duct 117 as hot air for the blast furnace. .

FIG. 3 is a diagram illustrating an example of a schematic configuration of a hot stove control system. In FIG. 3, the solid line indicates the flow of signals, and the broken line indicates the flow of cold air, hot air, combustion gas, and combustion air.
FIG. 3 shows an example in which four hot stoves 100a to 100d are attached to one blast furnace. Moreover, these four hot stove 100a-100d shall operate | move by a staggered parallel system.
FIG. 4 is a diagram for explaining an example of an outline of an operation schedule in the staggered parallel system.
In the example shown in FIG. 4, switching from blowing to combustion from left to right, combustion, switching from combustion to blowing, and blowing are performed in this order, and one cycle is configured by combining these periods. (See “1 cycle = switching period 401 + combustion period 402 + switching period 401 + air blowing period 403” shown in FIG. 4). And it is made to wrap a part of ventilation period of 2 units | sets (for example, hot stove 1 and hot stove 2) which back and forth (adjacent) in the order which supplies hot air. Further, in the example shown in FIG. 4, for the sake of simplicity, the air blowing period and the combustion period are made the same length, so two units (for example, the hot air furnace 1 and the hot air furnace 3) that are not adjacent in the order in which hot air is supplied. When one hot stove is in the blowing period, the other hot stove is in the burning period, and when one hot stove is in the burning period, the other hot stove is in the blowing period. However, this is not necessarily required if a part of the blowing period of the two units (for example, the hot stove 1 and the hot stove 2) that are back and forth (adjacent) in the order in which the hot air is supplied is wrapped (the blowing period). And the combustion period need not be the same length).

Returning to the description of FIG. 3, the control system for the hot stove includes a control device 300 that controls the operation of the hot stoves 100 a to 100 d. The control device 300 includes a hot stove control computer 301, an input / output device 302, a flow rate controller 304, a temperature controller 305, and opening degree controllers 313a to 313c.
The hot stove control computer 301 performs a calculation for operating the hot stove 100a to 100d based on preset input data. Data input to the hot stove control computer 301 is performed via an input / output device 302 as an interface unit. Examples of data input to the input / output device 302 include the following. First, as data based on the operation of the input device 312 by the operator of the hot stove, there is data of the next blowing condition (the blowing condition of the next cycle). In addition, there is data measured by a hot air thermometer 310 that measures the temperature (air blowing temperature) of hot air discharged from the hot air furnaces 100a to 100d. In addition, there is data measured by an air flow meter 307 that measures the flow rate of the cool air blown from the blower 306 (air flow rate). Further, there is data measured by a cold air thermometer 308 that measures the temperature of the cold air blown from the blower 306. Moreover, although illustration is abbreviate | omitted, there exists other operation performance data output from the other sensor incidental to each hot stove 100a-100d.

In this embodiment, the hot stove control computer 301 executes an input heat amount control program based on the input data, and individually calculates the input heat amount to be input to each hot stove 100a to 100d for each hot stove 100a to 100d. Using the result, the flow rate of the combustion gas is calculated individually for each hot stove 100a to 100d. Then, the hot stove control computer 301 instructs the flow rate of the combustion gas to the flow rate controllers 304a to 304d provided corresponding to the hot stove 100a to 100d.
The flow rate controllers 304a to 304d adjust the opening and closing operations of the gas butterfly valves 131a to 131d so that the flow rate instructed from the hot stove control computer 301 becomes as instructed.

Moreover, the hot stove control computer 301 sets the temperature obtained based on the operation of the input device 312 by the operator in the temperature controller 305 as a target value of the temperature of the hot air discharged from the hot stove 100a to 100d. The temperature controller 305 instructs the target opening degree to the opening degree controllers 313a to 313d that adjust the opening and closing operations of the blower butterfly valves 125a to 125d. For example, if it is a period during which air is blown by the two hot stoves 100, the temperature controller 305 opens the opening degree of the blow butterfly valve 125 of the hot stove 100 that blows in advance if the blowing temperature is high, The opening degree of the blowing butterfly valve 125 of the hot stove 100 that blows and blows the air is closed. On the other hand, if the blowing temperature is low, the temperature controller 305 closes the opening degree of the blowing butterfly valve 125 of the hot stove 100 that blows in advance, and then sets the blowing butterfly valve 125 of the hot stove 100 that blows behind. Open the opening. Since the hot blast furnace 100 that blows air first is undergoing heat exchange, the hot air temperature is low, and the hot blast furnace 100 that blows air afterwards is sufficiently stored, so the hot air temperature is high. The blowing temperature can be controlled by adjusting the opening degree of the blowing butterfly valve 125 (distribution of air volume). In addition, when the air temperature is high during the period when the air is blown by one hot stove 100, the cold air butterfly valve 123 is opened and the cold air is mixed into the hot air to adjust the air temperature. During the period when the air is blown by one hot stove 100, the opening degree of the blow butterfly valve is kept constant.
The air blower 306 blows the cool air of the air volume set in the air flow rate controller 309. The setting of the blower flow rate controller 309 is changed at the blower factory.

Further, the hot stove control computer 301 causes the display device 303 to display a screen based on the calculation result as described above via the input / output device 302.
The hot stove control computer 301 can be realized by using, for example, a computer including a CPU, a ROM, a RAM, and an HDD. For example, the above-described program is stored in the HDD and executed by the CPU.
Here, the configuration and operation of only the portions necessary for the description of the present embodiment will be described, and the description of the configuration and operation of the portions unnecessary for the description of the present embodiment will be omitted.

  FIG. 5 is a block diagram illustrating an example of a functional configuration of the hot stove control computer 301. Each of the following blocks can be realized, for example, by the CPU executing the input heat amount control program. Also in this embodiment, execution of the input heat amount control program starts when one cycle of each of the hot stoves 100a to 100d is completed in the same manner as the control of the conventional hot stove. Then, the input heat amount control program calculates the input heat amount (combustion gas flow rate) input to the hot stove 100 corresponding to the combustion period in the next cycle until the end of the first switching period in the next cycle. For example, when the period indicated as “1 cycle” in FIG. 4 is the next cycle, the first switching period in the next cycle is the switching period 401, and the combustion period in the next cycle is the combustion period 402. Yes, the corresponding hot stove 100 is the hot stove 100a. In addition, since the time constant of a hot stove is large, it is common to calculate and control in advance the amount of heat to be input every cycle in this way.

(Blowing period theoretical heat release calculation unit 501)
The blowing period theoretical heat radiation amount calculation units 501a to 501d are different only in the hot stove 100a to 100d to be calculated, and here, the blowing period theoretical heat radiation amount calculation units 501a to 501d are collectively described. Here, an example in which the blowing period theoretical heat release calculation units 501a to 501d execute a calculation corresponding to the “blowing period theoretical heat release calculation 1” in the input heat amount control method of the hot stove described in Patent Document 2 will be described. However, other known calculation procedures may be used.
The ventilation period theoretical heat release amount calculation unit 501 includes a next scheduled blowing temperature BT, a scheduled blowing flow rate BV, and a scheduled blowing moisture BM requested from the blast furnace operation as the next blowing condition at the end of blowing in this one cycle. From the scheduled blowing time Tw of the relevant furnace determined from the repeated operation of the furnace and the current cold wind temperature CT, the blowing period theoretical heat release QBV in the blowing period of the next cycle is determined as described below. This air flow period theoretical heat release amount QBV is a theoretical heat amount to be radiated during the air flow period of the next cycle, and is a base of the necessary heat storage amount.
That is, the next blowing condition data of the corresponding hot stove 100, which is the operation condition (setting condition) required in the next blowing process, is acquired by, for example, input by an operator. That is, the next blowing condition indicates a blowing condition to be satisfied in the blowing period of the next cycle. If the period indicated as “1 cycle” in FIG. 4 is the next cycle, the blowing period of the next cycle is the blowing period 403.
The next air blowing condition includes the following information.
Next scheduled air flow (cold air) flow rate BV [Nm ³ / min]
Next scheduled ventilation (hot air) temperature BT [° C]
Next scheduled ventilation (cold air) moisture BM [volume ratio]
Next scheduled ventilation time Tw [min]

Further, the blowing period theoretical heat release calculation unit 501 acquires the cold air temperature (air blowing temperature) CT [° C.] from the measured value of the cold air thermometer 308.
Further, the blowing period theoretical heat release calculation unit 501 reads the following physical property values of air and water stored in advance in the HDD or the like.
Air hot specific heat ^{CAh [kcal / Nm 3 · ℃} ]
Air cold specific heat ^{CAc [kcal / Nm 3 · ℃} ]
Moisture specific heat CHh [kcal / Nm ³・ ℃]
Moisture cold specific heat ^{CHc [kcal / Nm 3 · ℃} ]

Then, the blowing period theoretical heat release calculating unit 501 substitutes the acquired information into the following equation (1), and the blowing period theoretical heat release QBV (n, i) in the blowing period of the next cycle n of the hot stove i. Ask for.
QBV (n, i) = Σ [BV (n, i) × [{BT (n, i) × CAh−CT × CAc] + BM (n, i) × [BT (n, i) × CHh−CT × CHc}] × Tj (n, i)] (1)
In the equation (1), Σ represents integration for j. Here, BV (n, i) is as follows.
Two ventilation periods in the first half; BV (n, i) = a (n, i) × BV, Tj (n, i) = T1 (n, i)
One ventilation period; BV (n, i) = BV, Tj (n, i) = T2 (n, i)
Two ventilation periods in the latter half; BV (n, i) = b (n, i) × BV, Tj (n, i) = T3 (n, i)
Here, a and b are values input by the operator operating the input device 312. When the same flow rate is blown during the two blowing periods, a = 1/2 and b = 1/2.
Further, the following expression (2) is established.
T1 (n, i) + T2 (n, i) + T3 (n, i) = Tw (n, i) (2)
Here, Tw (n, i) is a scheduled air blowing period, and is a value input by the operator by operating the input device 312. Further, T1 (n, i), T2 (n, i), and T3 (n, i) are obtained on the basis of a scheduled start / end time signal of combustion blast and the like and a scheduled blast time Tw (n, i).

(Thermal efficiency calculation unit 502)
Since the heat removal efficiency calculation units 502a to 502d also differ only in the hot stove 100a to 100d to be calculated, here, the heat removal efficiency calculation units 502a to 502d will be described collectively.
The heat removal efficiency calculation unit 502 obtains the combustion gas flow rate (instantaneous value) Gv (t) [Nm ³ / min] based on the measurement value of the combustion gas flow meter 132. Further, the heat removal efficiency calculation unit 502 calculates the combustion gas calorie (its instantaneous value) Gcal [kcal / Nm ³ ]. The combustion gas calorie can be obtained, for example, based on a measurement value of a gas calorimeter that measures the gas calorie of the combustion gas provided in the gas supply duct 112.
Then, the heat removal efficiency calculation unit 502 substitutes the acquired information into the following equation (3) to calculate the actual input heat amount Qinm [kcal] in the cycle j of the hot stove i.

In equation (3), tbs is the combustion start time in cycle j, and tbe is the combustion end time in cycle j.
Further, the heat removal efficiency calculation unit 502 acquires the air temperature (its instantaneous value) Bt (t) [° C.] from the measurement value of the hot air thermometer 310. Further, the heat removal efficiency calculation unit 502 acquires the cold air temperature (instantaneous value) Ct (t) [° C.] from the measured value of the cold air thermometer 308. Further, the heat removal efficiency calculation unit 502 calculates the blast moisture (instantaneous value) Bm (t) [volume ratio] from the measured value of a hygrometer (not shown) disposed on the upstream side of the cold air introduction duct 116. get. Further, the heat removal efficiency calculation unit 502 obtains the air flow rate (instantaneous value) Bv (t) [Nm ³ / min] from the measured value of the air flow meter 307. Further, the heat removal efficiency calculation unit 502 reads the following physical property values stored in advance in the HDD or the like.
Air hot specific heat ^{CAh [kcal / Nm 3 · ℃} ]
Air cold specific heat ^{CAc [kcal / Nm 3 · ℃} ]
Moisture specific heat CHh [kcal / Nm ³・ ℃]
Moisture cold specific heat ^{CHc [kcal / Nm 3 · ℃} ]
Then, the heat removal efficiency calculation unit 502 substitutes the acquired information into the following equation (4) to calculate the actual blown heat quantity Qout [kcal] in the cycle j of the hot stove i.

In the equation (4), tws is the air blowing start time in the cycle j of the hot stove i, and twe is the air blowing end time in the cycle j.
Since the thermal efficiency does not change suddenly in a hot stove with a large heat capacity, the heat removal efficiency calculation unit 502 calculates the heat removal efficiency η by the following equation (5) by moving average of the actual heat balance in the same manner as in Patent Document 2. calculate. That is, the “actual input heat amount Qinm in the cycle j of the hot stove i” obtained by the equation (3) and the “actual blown heat amount Qout in the cycle j of the hot stove i” obtained by the equation (4) are stored in the HDD or the like in advance. By substituting the furnace specific correction coefficient ki into the following formula (5), the heat removal efficiency η (n, i) in the next cycle n of the hot stove i is calculated.

In equation (5), in order to eliminate the effects of fluctuations in the atmospheric temperature during the day, in the steady state for the past one day (wind reduction / decompression / temperature reduction / wind increase / pressure increase / temperature increase are within a predetermined range). The number of cycles that were present is the total range. The furnace-specific correction coefficient ki is a coefficient given to each hot stove i.
(Necessary input heat amount calculation unit 503)
The necessary input heat amount calculation units 503a to 503d are also different only in the hot stove 100a to 100d to be calculated, and therefore the necessary input heat amount calculation units 503a to 503d are also collectively described.

The necessary input heat amount calculation unit 503 calculates “the ventilation period theoretical heat release amount QBV (n, i) in the blowing period of the next cycle n of the hot stove i” obtained by the blowing period theoretical heat release calculation unit 501 and the heat removal efficiency calculation. Substrate 502 substitutes the “heat removal efficiency η (n, i) in the next cycle n of the hot stove i” into the following equation (6) to obtain the required input heat amount in the next cycle n of the hot stove i Qin (n, i) [kcal] is calculated.
Qin (n, i) = [QBV (n, i)] / η (n, i) (6)

(Input heat amount correction coefficient setting unit 504)
The input heat amount correction coefficient setting unit 504 multiplies the “necessary input heat amount Qin (n, i) in the next cycle n of the hot stove i” obtained by the required input heat amount calculation unit 503 by the input heat amount correction coefficient A [−]. (= Qin (n, i) × A). The input heat amount correction coefficient A [−] is normally “1”. However, when viewed as the whole of the four hot stoves 100a to 100d, the hot stove 100 is in a state of reduced wind temperature, and when viewed as the entire four hot stoves 100a to 100d, the thermal efficiency η of the hot stove 100 Is decreased, an input heat amount correction coefficient A is calculated by an input heat amount correction coefficient calculation unit 505 described later. In this case, the input heat amount correction coefficient setting unit 504 uses the input heat amount correction coefficient A calculated by the input heat amount correction coefficient calculation unit 505 until instructed by the operator. In other cases, the input heat amount correction coefficient setting unit 504 uses “1” as the input heat amount correction coefficient A.

(Combustion gas flow rate setting unit 506)
Since the combustion gas flow rate setting units 506a to 506d are different only in the hot stove 100a to 100d to be calculated, here, the combustion gas flow rate setting units 506a to 506d will be described collectively.
The combustion gas flow rate setting unit 506 acquires (calculates) a combustion gas flow rate (instantaneous value) Gv [Nm ³ / min] based on the measurement value of the combustion gas flow meter 132. The combustion gas flow rate setting unit 506 acquires (calculates) combustion gas calorie (instantaneous value) Gcal [kcal / Nm ³ ] based on the measurement value of the gas calorimeter.
Then, the combustion gas flow rate setting unit 506 calculates the input heat quantity Qina [kcal] by substituting the acquired information into the following equation (7).

In the equation (7), tbs is the combustion start time, and tb is the combustion elapsed time [min].
The combustion gas flow rate setting unit 506 then calculates “the required input heat amount Qin (n, i) in the next cycle n of the hot stove i” multiplied by the input heat amount correction coefficient A by the input heat amount correction coefficient setting unit 504, and combustion. The input heat quantity Qina (tb) at the elapsed time tb, the scheduled combustion time Tb (n, i) in the next cycle n of the hot stove i, and the combustion gas calorie Gcal (tb) at the elapsed combustion time tb are as follows ( 8) Substituting into the equation, the set value G Vo [Nm ³ / min] of the combustion gas flow rate during the combustion period in the next cycle n of the hot stove i is calculated.
GVo (tb) = (Qin (n, i) −Qina (tb)) / (Tb (n, i) −tb) / Gcal (tb)) (8)
Then, the combustion gas flow rate setting unit 506 sets the calculated “setting value G Vo of the combustion gas flow rate during the combustion period in the next cycle n of the hot stove furnace i” for the flow rate controller 304 corresponding to itself.

(Input heat amount correction coefficient calculation unit 505)
As described above, when the input heat quantity correction coefficient calculation unit 505 is viewed as a whole of the four hot stoves 100a to 100d, the hot stove 100 is in a state of reducing the temperature and the four hot stoves 100a to 100d. When the thermal efficiency η of the hot stove 100 is reduced as a whole, the input heat amount correction coefficient A is calculated.
FIG. 6 is a block diagram illustrating an example of a functional configuration of the input heat amount correction coefficient calculation unit 505.

<Input heat amount calculation unit 601>
The input heat quantity calculation unit 601 sets the combustion gas flow rate (instantaneous value) Gv [Nm ³ / min] based on the measurement value of the combustion gas flow meter 132 every time a predetermined time (here, 1 minute) elapses. Get in. In addition, the input calorific value calculation unit 601 sets the combustion gas calorie (instantaneous value) Gcal [kcal / Nm ³ ] based on the measured value of the gas calorimeter every time a predetermined time (here, 1 minute) elapses. Get in. Note that the measurement value acquired by the input heat amount calculation unit 601 is a measurement value obtained at substantially the same timing.
Then, the input heat amount calculation unit 601 substitutes the acquired information into the following equation (9) to calculate the input heat amount (instantaneous value) Qinp [kcal / min] of the entire four hot stove 100a to 100d. .
Qinp = Gcal × Gv (9)

<Input heat amount moving average calculation unit 602>
The input heat amount moving average calculation unit 602 calculates a moving average value Qins [kcal / min] for a predetermined time (here, 100 minutes) of the input heat amount Qinp calculated by the input heat amount calculation unit 601.

<Blast heat calculation unit 603>
The blast heat quantity calculation unit 603 obtains the blast flow rate BV [Nm ³ / min] based on the measurement value of the blast flow meter 307 every time a predetermined time (here, 1 minute) elapses. The blast heat quantity calculation unit 603 obtains the blast temperature BT [° C.] every time a predetermined time (here, 1 minute) elapses based on the measurement value of the hot air thermometer 310. Further, the blast heat quantity calculation unit 603 acquires the cold air temperature CT [° C.] based on the measured value of the cold air thermometer 308 every time a predetermined time (here, 1 minute) elapses. In addition, the measured value which the ventilation heat quantity calculation part 603 acquires is a measured value obtained at substantially the same timing. The blast heat quantity calculation unit 603 reads the following physical property values stored in advance in the HDD or the like.
Air hot specific heat ^{CAh [kcal / Nm 3 · ℃} ]
Air cold specific heat ^{CAc [kcal / Nm 3 · ℃} ]
Then, the blown heat amount calculation unit 603 substitutes the acquired information into the following expression (10) to calculate the blown heat amount (instantaneous value) Qoutp [kcal / min] of the entire four hot stove furnaces 100a to 100d. .
Qoutp = BV × (BT × CAh−CT × CAc) (10)

<Blast heat amount moving average calculation unit 604>
The blast heat quantity moving average calculation unit 604 calculates a moving average value Qouts [kcal / min] for a predetermined time (here, 100 minutes) of the blast heat quantity Qoutp calculated by the blast heat quantity calculation unit 603. The timing at which the input heat amount moving average calculation unit 602 and the blown heat amount moving average calculation unit 604 perform the calculation is substantially synchronized.

<Thermal efficiency calculator 605>
The thermal efficiency calculator 605 calculates the moving average value Qins of the input heat quantity Qinp for a predetermined time calculated by the input heat quantity moving average calculator 602 and the blast heat quantity Qoutp for a predetermined time calculated by the blast heat quantity moving average calculator 604. Substituting the moving average value Qouts into the following equation (11), the moving average value ηs [−] at a predetermined time (here, 100 minutes) of the thermal efficiency of the four hot stoves 100a to 100d is calculated. .
ηs = Qouts / Qins (11)

<Wind reduction / warming correction start / end determination unit 606>
The wind reduction / temperature reduction correction start / end determination unit 606 determines whether the operator has operated ON / OFF of the wind reduction / temperature reduction correction start button PBS or the wind reduction / temperature reduction correction end button PBE included in the input device 312. judge. The wind and temperature reduction correction start button PBS is used by the operator to specify timing for setting reference values Qins-0, Qouts-0, and ηs-0 by a reference value setting unit 607 described later. When the operator determines that the hot stove 100 has been in a state of reduced wind and reduced temperature, the operator is assumed to operate the reduced wind and reduced temperature correction start button PBS.

  On the other hand, the wind reduction / temperature reduction correction end button PBE is used by the operator to specify the timing for returning the input heat amount correction coefficient A calculated by the input heat amount correction coefficient calculation unit 610, which will be described later, to the original value (= 1). When the operator determines that the hot stove 100 has returned to the steady state from the reduced wind and temperature reduction state, the operator operates the wind reduction and temperature reduction end button PBE. When it is determined by the wind reduction / temperature decrease correction start / end determination unit 606 that the wind decrease / temperature decrease correction end button PBE has been operated, the input heat amount correction coefficient setting unit 504 sets “1” as the input heat amount correction coefficient A. .

<Reference value setting unit 607>
When the reference value setting unit 607 determines that the wind reduction / temperature reduction correction start button PBS is operated by the wind reduction / temperature reduction correction start / end determination unit 606, the reference value setting unit 607 updates the latest moving average value Qins of the input heat amount Qinp for a predetermined time. Value, the latest value of the moving average value Qouts in the predetermined time of the blown heat quantity Qoutp, and the latest value of the moving average value ηs in the predetermined time of the thermal efficiency are obtained, and these are obtained as reference values Qins-0 and Qouts-0, respectively. , Ηs-0 (stored in RAM or the like).

<Wind reduction and temperature reduction determination unit 608>
The wind reduction / temperature reduction determination unit 608 determines whether or not the hot air furnace 100 is in a state where the temperature is reduced and reduced as a whole of the four hot air furnaces 100a to 100d. That is, the wind reduction / temperature reduction determination unit 608 has a value obtained by subtracting the reference value Qouts-0 from the latest value of the moving average value Qouts of the blast heat quantity Qoutp for a predetermined time calculated by the blast heat quantity moving average calculation unit 604. It is determined whether or not it is below a preset wind and temperature reduction determination value ε1. That is, the wind reduction and temperature reduction determination unit 608 determines whether or not the following expression (12) is satisfied.
Qouts-Qouts-0 <ε1 (12)

<Thermal efficiency decrease determination unit 609>
The thermal efficiency decrease determination unit 609 determines whether or not the thermal efficiency of the hot stove 100 as a whole is reduced in the four hot stove 100a to 100d. That is, the thermal efficiency decrease determination unit 609 is a thermal efficiency decrease in which a value obtained by subtracting the reference value ηs-0 from the latest value of the moving average value ηs for a predetermined time of the thermal efficiency calculated by the thermal efficiency calculation unit 605 is set. It is determined whether or not it is below the determination value ε2. That is, the thermal efficiency decrease determination unit 609 determines whether or not the following expression (13) is satisfied.
ηs−ηs-0 <ε2 (13)

<Input heat amount correction coefficient calculation unit 610>
The input heat amount correction coefficient calculation unit 610 determines that the hot air furnace 100 is in the state of reduced air temperature reduction as a whole of the four hot air furnaces 100a to 100d by the reduced air temperature reduction determination unit 608 (when the equation (12) is satisfied). If it is determined that the thermal efficiency of the hot stove 100 is reduced as a whole of the four hot stoves 100a to 100d (determined that the expression (13) is satisfied), the input heat amount correction coefficient A is calculated. To do.
The input heat amount correction coefficient calculation unit 610 obtains the latest value of the moving average value Qins for a predetermined time of the input heat amount Qinp and the latest value of the moving average value Qouts for a predetermined time of the blown heat amount Qoutp. Further, the input heat amount correction coefficient calculation unit 610 acquires the reference values Qins-0 and Qouts-0 set by the reference value setting unit 607. Then, the input heat amount correction coefficient calculation unit 610 calculates the input heat amount correction coefficient A [−] by substituting the acquired information into the following equation (14).
A = (Qouts / Qouts-0) x (Qins-0 / Qins) (14)
The input heat amount correction coefficient setting unit 504 supplies the input heat amount correction coefficient A as the input heat amount correction coefficient A until it is determined by the wind reduction / temperature decrease correction start / end determination unit 606 that the wind decrease / temperature decrease correction end button PBE is operated. The value calculated by the heat amount correction coefficient calculation unit 610 is set.

FIG. 7 is a diagram for explaining the meaning of the input heat amount correction coefficient A. In FIG.
In FIG. 7, the start time point indicates a time point when the operator operates the wind reduction / temperature reduction correction start button PBS. The moving average value ηs-0 at a predetermined time of the thermal efficiency of the entire four hot stoves 100a to 100d at the start time is expressed by the following equation (15).
ηs-0 = Qouts-0 / Qins-0 (15)
Further, the moving average value ηs of the thermal efficiency of the entire four hot stoves 100a to 100d at the present time for a predetermined time is expressed by the following equation (16).
ηs = Qouts / Qins (16)

In FIG. 7, at present, the thermal efficiency is lower than that at the start time. For this reason, the amount of input heat is excessive. Therefore, the moving average value Qins of the total amount of input heat of the four hot stoves 100a to 100d at the present time is lowered until it reaches a value Qins ′ determined by the following equation (17). In this way, it is possible to correct the input heat amount so as not to lower the thermal efficiency from the starting point.
Qouts / Qins' = Qouts-0 / Qins-0 (17)
When the equation (17) is modified, the following equation (18) is obtained.
Qins' = (Qouts / Qouts-0) x Qins-0 (18)
When the input heat amount correction coefficient A is defined as in the following equation (19), the above-described equation (14) is obtained.
A = Qins' / Qins (19)
As described above, in the present embodiment, when the hot stove 100 is in a state of reduced wind temperature and when the thermal efficiency of the hot stove 100 is lowered, it is more than when the cooler and cooler correction start button PBS is operated. However, the input heat amount correction coefficient A for correcting the input heat amount so as not to lower the thermal efficiency is multiplied by the required input heat amount Qin (n, i) in the next cycle n of the hot stove i.

(flowchart)
Next, referring to the flowchart of FIG. 8, the set value GVo of the combustion gas flow rate during the combustion period in the next cycle n of the hot stove i is individually set for each of the four hot stoves 100a to 100d. An example of the operation when doing this will be described. As described above, when the above-described cycle in each hot stove 100a to 100d is completed, execution of the flowchart of FIG. 8 is started.
First, in step S <b> 1, the blowing period theoretical heat release calculation unit 501 corresponding to the hot stove 100 whose cycle has ended performs the calculation of the above-described equation (1), and the blowing period of the next cycle n of the hot stove 100. The air flow period theoretical heat release QBV (n, i) at is calculated.
Next, in step S <b> 2, the heat removal efficiency calculation unit 502 corresponding to the hot stove 100 whose cycle has been completed performs the calculation of the above-described equation (5), and the heat removal efficiency η ( n, i) is calculated.

Next, in step S <b> 3, the required input heat amount calculation unit 503 corresponding to the hot stove 100 whose cycle has ended performs the calculation of the above-described equation (6), and the required input heat amount in the next cycle n of the hot stove 100. Qin (n, i) is calculated.
Next, in step S4, the input heat amount correction coefficient setting unit 504 multiplies the required input heat amount Qin (n, i) calculated in step S3 by the input heat amount correction coefficient A.
Next, in step S <b> 5, the combustion gas flow rate setting unit 506 corresponding to the hot stove 100 whose cycle has been completed performs the calculation of the above-described formulas (7) and (8), and the next cycle of the hot stove 100. The set value GVo of the combustion gas flow rate during the combustion period at n is calculated, and the calculated set value GVo is set in the flow rate controller 304 corresponding to the hot stove 100.

Next, an example of the operation of the input heat amount correction coefficient calculation unit 505 when calculating the moving average value Qins of the input heat amounts of the four hot stoves 100a to 100d for a predetermined time will be described with reference to the flowchart of FIG. To do.
First, in step S11, the input heat amount calculation unit 601 waits until the input heat amount (its instantaneous value) Qinp is calculated by the above-described equation (9). As described above, in this embodiment, the input heat quantity Qinp is calculated every other minute.
Then, when it is time to calculate the input heat quantity Qinp, the process proceeds to step S12. In step S12, the input heat amount calculation unit 601 obtains the combustion gas flow rate (instantaneous value) Gv based on the measurement value of the combustion gas flow meter 132.
Next, in step S13, the input heat amount calculation unit 601 obtains the combustion gas calorie (its instantaneous value) Gcal based on the measured value of the gas calorimeter.
Note that the processing in steps S12 and S13 may be reversed.

Next, in step S14, the input heat amount calculation unit 601 calculates the above-described equation (9) to calculate the input heat amounts (instantaneous values) Qinp of the four hot stove 100a to 100d as a whole, and the like. To remember.
Next, in step S15, the input heat amount moving average calculating unit 602 determines whether it is time to calculate the moving average value Qins of the input heat amounts Qinp of the four hot stoves 100a to 100d as a whole. As described above, in this embodiment, the moving average value Qins of the input heat quantity Qinp is calculated every 100 minutes.

As a result of this determination, if it is not time to calculate the moving average value Qins of the input heat amounts Qinp of the four hot stoves 100a to 100d, the process returns to step S11. On the other hand, when it is time to calculate the moving average value Qins of the input heat quantity Qinp of the entire four hot stoves 100a to 100d, the process proceeds to step S16.
In step S16, the input heat amount moving average calculating unit 602 calculates a moving average value Qins for a predetermined time (100 minutes) of the input heat amount Qinp calculated in step S14 and stores it in the RAM or the like.

Next, an example of the operation of the input heat amount correction coefficient calculation unit 505 when calculating the moving average value Qouts for a predetermined time of the blast heat amount of the entire four hot stoves 100a to 100d will be described with reference to the flowchart of FIG. To do.
First, in step S21, the blown heat amount calculation unit 603 stands by until the timing for calculating the blown heat amount (its instantaneous value) Qoutp by the above-described equation (10). As described above, in this embodiment, the blast heat quantity Qoutp is calculated every other minute.
Then, when it is time to calculate the blast heat quantity Qoutp, the process proceeds to step S22. If it progresses to step S22, the ventilation heat quantity calculation part 603 will acquire the ventilation flow volume BV based on the measured value of the ventilation flowmeter 307. FIG.

Next, in step S <b> 23, the blast heat quantity calculation unit 603 acquires the blast temperature BT based on the measurement value of the hot air thermometer 310.
Next, in step S <b> 24, the blast heat quantity calculation unit 603 acquires the cold air temperature CT based on the measurement value of the cold air thermometer 308.
Next, in step S25, the blast heat quantity calculation unit 603 reads the air-heat specific heat CAh and the air-cooling specific heat CAc from the HDD or the like.
Note that the order of steps S22 to S25 may be any order.

Next, in step S26, the blown heat amount calculation unit 603 performs the calculation of the above-described equation (10) to calculate the blown heat amount (instantaneous value) Qoutp of the entire four hot stove furnaces 100a to 100d.
Next, in step S27, the blast heat quantity moving average calculation unit 604 determines whether it is time to calculate the moving average value Qouts of the blast heat quantity Qoutp of the entire four hot stoves 100a to 100d. As described above, in this embodiment, the moving average value Qouts of the blast heat quantity Qoutp is calculated every 100 minutes.

As a result of this determination, if it is not time to calculate the moving average value Qouts of the blast heat quantity Qoutp of the entire four hot stoves 100a to 100d, the process returns to step S21. On the other hand, when it is time to calculate the moving average value Qouts of the blast heat quantity Qoutp of the entire four hot stoves 100a to 100d, the process proceeds to step S28.
In step S28, the blast heat quantity moving average calculating unit 604 calculates the moving average value Qouts of the blast heat quantity Qoutp calculated in step S26 for a predetermined time (100 minutes) and stores it in the RAM or the like.
As described above, the moving average value Qins of the input heat quantity Qinp for a predetermined time is calculated in step S16 of FIG. 9, and the moving average value Qouts of the blown heat quantity Qoutp for a predetermined time is calculated in step S28 of FIG. Then, the thermal efficiency calculation unit 605 calculates the moving average value ηs in a predetermined time (100 minutes) of the thermal efficiency of the entire four hot stoves 100a to 100d by performing the calculation of the above-described equation (11), and the RAM or the like. To remember.

Next, an example of the operation of the input heat amount correction coefficient calculation unit 505 when calculating the input heat amount correction coefficient A will be described with reference to the flowchart of FIG.
First, in step S31, the wind reduction / temperature reduction correction start / end determination unit 606 determines whether or not the operator has operated the wind reduction / temperature reduction correction start button PBS included in the input device 312. If the result of this determination is that the wind and temperature reduction correction start button PBS has not been operated, the processing according to the flowchart of FIG. 11 is terminated.
On the other hand, if the wind reduction / temperature correction start button PBS is operated, the process proceeds to step S32. In step S32, the reference value setting unit 607 determines the latest value of the moving average value Qins in the predetermined time of the input heat amount Qinp, the latest value of the moving average value Qouts in the predetermined time of the blown heat amount Qoutp, and the predetermined heat efficiency. The latest values of the moving average value ηs in time are set as reference values Qins-0, Qouts-0, and ηs-0, respectively.

Next, in step S33, the wind reduction and temperature reduction determination unit 608 waits until the above-described expression (12) is satisfied. If the expression (12) is satisfied, the process proceeds to step S34. In step S34, the thermal efficiency decrease determination unit 609 determines whether or not the above-described expression (13) is satisfied. If the result of this determination is that the expression (13) is not satisfied, the routine returns to step S33. On the other hand, if the expression (13) is satisfied, the process proceeds to step S35.
Note that the processing order of steps S33 and S34 may be reversed.
In step S35, the input heat amount correction coefficient calculation unit 610 calculates the input heat amount correction coefficient A by performing the calculation of the above-described equation (14).

Next, in step S36, the input heat amount correction coefficient setting unit 504 sets the input heat amount correction coefficient A to the value calculated in step S35.
Next, in step S <b> 37, the wind reduction / temperature reduction correction start / end determination unit 606 determines whether the operator has operated the wind reduction / temperature reduction correction end button PBE included in the input device 312. If the result of this determination is that the wind and temperature reduction correction end button PBE has not been operated, the routine returns to step S33. As described above, in the present embodiment, the value calculated in step S35 is used as the input heat amount correction coefficient A until the wind reduction / temperature reduction correction end button PBE is operated regardless of the operating state of the hot stove 100. . This is based on the idea that the operator decides whether or not the wind reduction and temperature reduction state is avoided. However, it is not always necessary to do this, and it may be determined in this step S37 whether or not a predetermined operating condition that can be regarded as avoiding the reduced-temperature and reduced-temperature state is satisfied.
On the other hand, when the wind reduction / temperature correction end button PBE is operated, the process proceeds to step S38. In step S38, the input heat amount correction coefficient setting unit 504 sets “1” as the input heat amount correction coefficient A.

FIG. 12 is a diagram illustrating simulation results representing responses of input heat amount, blown heat amount, and thermal efficiency when the blower flow rate is changed. FIG. 12A is a diagram in the case where the input heat amount correction coefficient A is calculated when the wind reduction and temperature reduction state occurs as in the present embodiment, and FIG. 12B is the wind reduction and temperature reduction. It is a figure at the time of fixing the input calorie | heat amount correction coefficient A to "1" even if it will be in a state.
Here, a simulation was performed for the time T when the flow rate of air flow was lowered by 5 [%] stepwise. The simulation conditions are as follows.
Air temperature: 1200 [° C]
Air flow: 8000 [Nm ³ / min]
Blowing time: 90 [min]
Cold air temperature: 200 [° C]
Specific heat of air: 0.35 [kcal / Nm ³ · ° C]
Air cold specific heat: 0.30 [kcal / Nm ³ · ° C]
Combustion time: 90 [min]
Combustion gas calories: 1000 [kcal / Nm ³ ]
Wind reduction / temperature reduction judgment value ε1; 25 [MJ / min]
Thermal efficiency decrease judgment value ε2; 0.1 [%]
Input value of heat input Qins-0; 15 [GJ / min]
Standard value Qouts-0; 13 [GJ / min]
Thermal efficiency reference value ηs-0: 87 [%]

  As shown in FIG. 12 (a), as in the present embodiment, the input heat amount correction coefficient A is calculated when the temperature is reduced and the temperature is reduced, and the required input heat amount Qin (n, n, n is calculated using the input heat amount correction coefficient A. When i) is corrected, the thermal efficiency temporarily decreases with a change in the flow rate of air flow, but is maintained at a substantially constant value thereafter. This is because the input heat amount is suppressed by an appropriate amount according to the decrease in the blown heat amount. On the other hand, as shown in FIG. 12B, when the input heat amount correction coefficient A is fixed at “1”, the thermal efficiency is significantly lowered.

  As described above, in the present embodiment, the thermal efficiency of the four hot stoves 100a to 100d as a whole when the hot stove 100 is in the state of reduced wind and reduced temperature and the operator operates the reduced wind and cool down correction start button PBS. The input heat amount correction coefficient A is calculated so that ηs-0 is maintained, and the calculated input heat amount correction coefficient A is multiplied by the necessary input heat amount Qin (n, i) in the next cycle n of the hot stove i. did. Therefore, it is possible to prevent the thermal efficiency in the hot stove from being lowered as much as possible even when the temperature is reduced. Therefore, even when the amount of heat of hot air supplied from the hot stove 100 operating in the staggered parallel system to the blast furnace needs to be suddenly reduced from the initial plan, the thermal efficiency in the hot stove 100 is not lowered as much as possible. In this way, the operation of the hot stove 100 can be flexibly controlled and continued.

  It should be noted that the input heat amount of the next cycle in the steady state of each of the plurality of hot stoves 100a to 100d operated in the staggered parallel method is used before the combustion operation in the next cycle is started. If the calculation is made based on the “actual value of the heat balance relating to thermal efficiency” in each of 100d, it is not always necessary to calculate the required input heat amount as in equation (6). For example, the calculation may be performed using the method of Patent Document 1. That is, input heat amount = required heat storage amount / thermal efficiency = (blast heat amount−residual heat amount) / calculation of necessary input heat amount (calculation of heat balance) according to heat efficiency, or as described in Patent Document 1, from the current heat storage amount The required amount of heat input (calculation of heat balance) can be calculated by subtracting the amount of heat stored when the blowing period in the immediately preceding cycle starts.

Further, as in this embodiment, if the moving average value Qins of the input heat quantity Qinp for a predetermined time, the moving average value Qouts of the blown heat quantity Qoutp for a predetermined time, and the moving average value ηs of the thermal efficiency for a predetermined time are used, Although it is preferable because highly reliable data can be obtained, an instantaneous value may be used instead of the moving average value.
Further, Qouts-0−Qouts> ε1 may be used instead of the equation (12), and ηs-0−ηs> ε2 may be used instead of the equation (13). That is, whether or not the decrease in the current value (Qouts, ηs) relative to the reference value (Qouts-0, ηs-0) exceeds a predetermined value (wind reduction / decrease determination value ε1, thermal efficiency decrease determination value ε2). It only has to be determined.

  In the present embodiment, the input heat amount correction coefficient A when the wind is not reduced and the temperature is not reduced is set to “1”. However, this is not necessarily required. That is, the input heat amount correction coefficient setting unit 504 combusts Qin (n, i) obtained by the required input heat amount calculation unit 503 as it is without considering the input heat amount correction coefficient A when the temperature is not reduced or reduced. You may make it output to the gas flow volume setting part 506. FIG.

In the present embodiment, for example, by using the hot stove control computer 301, an example of the hot stove control computer is realized. Further, for example, by using the ventilation period theoretical heat release calculation unit 501, the heat removal efficiency calculation unit 502, and the required input heat amount calculation unit 503, an example of the required input heat amount calculation unit is realized. Here, the next one-cycle blowing condition input by the required input heat amount calculation means is, for example, the next blowing condition (next scheduled blowing (cold air) flow rate BV, next scheduled input, which is input by the blowing period theoretical heat release calculation unit 501) This is realized by using the blowing (hot air) temperature BT, the next scheduled blowing (hot air) moisture BM, and the next scheduled blowing time Tw). Moreover, the operation result value of the cold wind input by the necessary input heat amount calculation means is realized by using, for example, the measured value of the cold air thermometer 308 input by the ventilation period theoretical heat release calculation unit 501 and the heat removal efficiency calculation unit 502. . Further, the operation result value of the combustion gas input by the required input heat amount calculation means is realized by using, for example, the measurement value of the combustion gas flow meter 132 and the measurement value of the gas calorimeter input by the heat removal efficiency calculation unit 502. Is done. Moreover, the operation result value of the hot air input by the required input heat amount calculation means is realized by using the measured value of the hot air thermometer 310 input by the heat removal efficiency calculation unit 502.
Further, for example, by using the input heat amount calculation unit 601 and the input heat amount moving average calculation unit 602, an example of the input heat amount current value calculation unit is realized. Here, the operation result value of the combustion gas input by the input heat amount current value calculation means is obtained by using, for example, the measurement value of the combustion gas flow meter 132 and the measurement value of the gas calorimeter input by the input heat amount calculation unit 601. Realized.
Further, for example, by using the blown heat amount calculation unit 603 and the blown heat amount moving average calculation unit 604, an example of the blown heat amount current value calculation unit is realized. Here, the operation result value of the hot air input by the blast heat quantity current value calculation means is realized by using, for example, the measurement value of the blast flow meter 307 and the measurement value of the hot blast thermometer 310 input by the blast heat quantity calculation unit 603. Is done. Moreover, the operation result value of the cold wind input by the current value calculation unit of the blown heat is realized by using, for example, the measured value of the cold air thermometer 308 input by the blown heat amount calculation unit 603.
Further, for example, by using the thermal efficiency calculation unit 605, an example of a thermal efficiency current value calculation unit is realized.
Further, for example, by using the reference value setting unit 607, an example of the reference value setting unit is realized. Here, for example, an example of an operation for instructing the correction of the required input heat amount is realized by the ON operation of the wind reduction / temperature reduction correction start button PBS.
Further, for example, by using the wind reduction / temperature reduction determination unit 608, an example of the wind reduction / temperature reduction determination unit is realized. Further, for example, by using the thermal efficiency decrease determination unit 609, an example of a thermal efficiency decrease determination unit (process) is realized.
Further, for example, by using the input heat amount correction coefficient calculation unit 610, an example of the input heat amount correction coefficient calculation unit is realized.
Also, for example, an example of an operation for instructing to end the correction of the required input heat amount is realized by an ON operation of the wind reduction / temperature reduction correction end button PBE.
Further, for example, by using the combustion gas flow rate setting unit 506, the flow rate controller 304, and the control valve 131, an example of the flow rate adjustment step is realized.

The embodiment of the present invention described above can be realized by a computer executing a program. Further, a means for supplying the program to the computer, for example, a computer-readable recording medium such as a CD-ROM recording such a program, or a transmission medium for transmitting such a program may be applied as an embodiment of the present invention. it can. A program product such as a computer-readable recording medium that records the program can also be applied as an embodiment of the present invention. The programs, computer-readable recording media, transmission media, and program products are included in the scope of the present invention.
In addition, the embodiments of the present invention described above are merely examples of implementation in carrying out the present invention, and the technical scope of the present invention should not be construed as being limited thereto. Is. That is, the present invention can be implemented in various forms without departing from the technical idea or the main features thereof.

DESCRIPTION OF SYMBOLS 100 Hot-blast furnace 127 Air flow meter 132 Combustion gas flow meter 300 Controller 301 Hot-blast furnace control computer 302 Input / output device 303 Display device 304 Flow controller 307 Blow flow meter 308 Cold air thermometer 310 Hot air thermometer 312 Input device

Claims (9)

In order to control the combustion and blowing of a plurality of hot stoves operated in a staggered parallel system, a hot stove control calculation device that calculates the amount of heat input to each of the hot stoves,
For each of the plurality of hot stove furnaces, the required input heat amount in the next cycle of the operation of the hot stove furnace is set to the actual value of the heat balance related to the thermal efficiency of the hot stove furnace before the combustion period in the next one cycle. A necessary input heat amount calculation means to calculate using,
Input the operation result value of the combustion gas for performing the combustion, input heat amount current value calculation means for calculating the current value of the input heat amount of the plurality of hot stove whole,
The blower which inputs the operation result value of the hot air supplied from the hot air furnace to the blast furnace and the operation result value of the cold air supplied to the hot air furnace, and calculates the present value of the whole blast heat quantity of the plurality of hot air furnaces Current amount calculation means,
From the current value of the input heat amount and the current value of the blown heat amount, a thermal efficiency current value calculation unit that calculates a current value of the thermal efficiency of the entire plurality of hot stoves,
When an operation for instructing the input device to correct the required input heat amount is performed by an operator, the current value of the input heat amount calculated by the input heat amount current value calculating means and the current amount of blast heat Reference value setting means for setting the current value of the blast heat quantity calculated by the value calculation means and the current value of the thermal efficiency calculated by the thermal efficiency current value calculation means as reference values,
Whether or not the decrease in the current value of the blast heat quantity calculated by the blast heat quantity current value calculation means with respect to the reference value of the blast heat quantity set by the reference value setting means exceeds the wind reduction / temperature reduction judgment value. A wind-decreasing temperature-decision judging means,
Thermal efficiency decrease determination for determining whether or not the decrease in the current value of the thermal efficiency calculated by the current thermal efficiency value calculation means with respect to the reference value of the thermal efficiency set by the reference value setting means exceeds the thermal efficiency decrease determination value Means,
The decrease in current value with respect to the reference value of the blast heat quantity is determined to have exceeded the decrease in wind temperature reduction determination value by the wind reduction and temperature reduction determination means, and the current value with respect to the reference value of thermal efficiency is determined by the thermal efficiency decrease determination means. When it is determined that the decrease has exceeded the thermal efficiency decrease determination value, the input heat amount correction coefficient calculating means for calculating the input heat amount correction coefficient,
Multiplying the required input heat amount calculated by the required input heat amount calculation means by the input heat amount correction coefficient calculated by the input heat amount correction coefficient calculation means, the input heat amount in the next one cycle of each of the plurality of hot stove furnaces is obtained. An input heat amount calculation means for calculating,
The input heat amount correction coefficient calculation means calculates the input heat amount correction coefficient A [−] by the following equation (A), a hot stove control calculation apparatus.
A = (Qouts / Qouts-0) x (Qins-0 / Qins) (A)
Here, Qouts [kcal / min] is the current value of the blast heat quantity, Qouts-0 [kcal / min] is the reference value of the blast heat quantity, and Qins-0 [kcal / min] is the reference of the input heat quantity. The value Qins [kcal / min] is the current value of the input heat. For each of the plurality of hot stove furnaces, the necessary input heat amount calculation means calculates the necessary heat storage amount in the next one cycle by inputting the blowing condition of the next one cycle and the operation result value of the cold air. Means to do,
Input the actual operation value of the combustion gas to calculate the actual input heat amount, input the actual operation value of hot air and the actual operation value of cold air, calculate the actual blown heat amount, and calculate the actual input heat amount. Calculating the heat removal efficiency of the next one cycle using the actual blast heat quantity, for each of the plurality of hot stoves,
Means for calculating the required input heat amount in the next one cycle for each of the plurality of hot stoves using the necessary heat storage amount in the next one cycle and the heat removal efficiency in the next one cycle; The hot stove control calculation apparatus according to claim 1, further comprising: The input heat amount correction coefficient calculation means calculates the input heat amount correction coefficient until an operation for instructing the input device to end the correction of the required input heat amount is performed by an operator.
The input heat amount calculation means is the required input heat amount calculated by the required input heat amount calculation means until an operation is performed by the operator to instruct the input device to end the correction of the required input heat amount. The input heat quantity in each next cycle of the plurality of hot stove furnaces is calculated by multiplying the input heat quantity correction coefficient A calculated by the formula (A) by the input heat quantity correction coefficient calculating means. Or the hot stove control calculation apparatus of 2. The input heat amount current value calculating means calculates a moving average value of the input heat amount of the plurality of hot stove furnaces for a predetermined time as a current value of the input heat amount of the entire hot stove furnaces,
The blast heat amount current value calculating means calculates a moving average value of the blast heat amount of the plurality of hot stoves as a current value of the blast heat amount of the entire hot stoves,
The said thermal efficiency present value calculation means calculates the moving average value in the predetermined time of the thermal efficiency of the whole several hot stove as a present value of the thermal efficiency of the whole several hot stove. The hot stove control calculation apparatus according to any one of the above. A hot stove control method for controlling the amount of heat input to each of a plurality of hot stoves operated in a staggered parallel system,
For each of the plurality of hot stove furnaces, the required input heat amount in the next cycle of the operation of the hot stove furnace is set to the actual value of the heat balance related to the thermal efficiency of the hot stove furnace before the combustion period in the next one cycle. The required input calorie calculation process to calculate using,
Input the actual operation value of the combustion gas for performing the combustion, and calculate the current value of the input heat amount of the plurality of hot stove furnaces to calculate the current value of the input heat amount,
The blower which inputs the operation result value of the hot air supplied from the hot air furnace to the blast furnace and the operation result value of the cold air supplied to the hot air furnace, and calculates the present value of the whole blast heat quantity of the plurality of hot air furnaces Current heat value calculation process,
From the current value of the input heat amount and the current value of the blast heat amount, a thermal efficiency current value calculation step of calculating a current value of the thermal efficiency of the entire plurality of hot stoves,
When an operation for instructing the input device to correct the required input heat amount is performed by an operator, the current value of the input heat amount calculated by the input heat amount current value calculating step and the current amount of blast heat A reference value setting step for setting the current value of the blast heat quantity calculated by the value calculation step and the current value of the thermal efficiency calculated by the thermal efficiency current value calculation step as a reference value;
Whether or not the decrease in the current value of the blast heat amount calculated by the current value calculation step of the blast heat amount with respect to the reference value of the blast heat amount set by the reference value setting step exceeds the wind reduction and temperature reduction determination value. A wind-decreasing temperature-decision judging process,
Thermal efficiency decrease determination for determining whether or not a decrease in the current value of the thermal efficiency calculated by the current thermal efficiency value calculation step exceeds a thermal efficiency decrease determination value with respect to the thermal efficiency reference value set by the reference value setting step Process,
It is determined that the decrease in the current value with respect to the reference value of the blown heat amount exceeds the decrease in wind and temperature decrease determination value by the wind reduction and temperature reduction determination step, and the current value with respect to the reference value of the heat efficiency is determined by the thermal efficiency decrease determination step. When it is determined that the decrease exceeds the heat efficiency decrease determination value, an input heat amount correction coefficient calculation step for calculating an input heat amount correction coefficient;
Multiplying the required input heat amount calculated by the required input heat amount calculation step by the input heat amount correction coefficient calculated by the input heat amount correction coefficient calculation step, the input heat amount in each next cycle of the plurality of hot stoves is calculated. Heat input calculation process to
A flow rate adjusting step of adjusting the flow rate of the combustion gas supplied to the hot stove during the combustion period in the next one cycle based on the input heat amount calculated in the input heat amount calculation step;
In the input heat quantity correction coefficient calculation step, the input heat quantity correction coefficient A [−] is calculated by the following equation (A).
A = (Qouts / Qouts-0) x (Qins-0 / Qins) (A)
Here, Qouts [kcal / min] is the current value of the blast heat quantity, Qouts-0 [kcal / min] is the reference value of the blast heat quantity, and Qins-0 [kcal / min] The reference value of the input heat amount, Qins [kcal / min] is the current value of the input heat amount. For each of the plurality of hot stove furnaces, the necessary input heat amount calculating step calculates the necessary heat storage amount in the next one cycle by inputting the blowing condition of the next one cycle and the operation result value of the cold air. A process of performing;
Input the actual operation value of the combustion gas to calculate the actual input heat amount, input the actual operation value of hot air and the actual operation value of cold air, calculate the actual blown heat amount, and calculate the actual input heat amount. Calculating the heat removal efficiency of the next one cycle using the actual blown heat amount, and performing each of the plurality of hot stoves,
Calculating the necessary input heat amount in the next one cycle using the necessary heat storage amount in the next one cycle and the heat removal efficiency in the next one cycle, for each of the plurality of hot stoves; The hot stove control method according to claim 5, further comprising: The input heat amount correction coefficient calculation step calculates the input heat amount correction coefficient until an operation is performed by the operator to instruct the input device to end the correction of the required input heat amount.
In the input heat amount calculation step, the required input heat amount calculated in the required input heat amount calculation step until the operation for instructing the input device to end the correction of the required input heat amount is performed by the operator. 6. The input heat amount in each next cycle of the plurality of hot air furnaces is calculated by multiplying the input heat amount correction coefficient A calculated by the equation (A) in the input heat amount correction coefficient calculation step. Or the hot stove control method of 6. The input heat amount current value calculating step calculates the moving average value of the input heat amount of the plurality of hot stoves as a current value of the input heat amount of the entire hot stove,
The blast heat amount current value calculating step calculates a moving average value of the blast heat amount of the plurality of hot stove furnaces over a predetermined time as a current value of the blast heat amount of the plurality of hot stove furnaces,
The said thermal efficiency present value calculation process calculates the moving average value in the predetermined time of the thermal efficiency of the whole several hot stove as a present value of the thermal efficiency of the whole several hot stove. The hot stove control method according to any one of the above. A computer program for causing a computer to calculate the amount of heat input to each of the hot stoves to control combustion and blowing of a plurality of hot stoves operated in a staggered parallel system,
For each of the plurality of hot stove furnaces, the required input heat amount in the next cycle of the operation of the hot stove furnace is set to the actual value of the heat balance related to the thermal efficiency of the hot stove furnace before the combustion period in the next one cycle. The required input calorie calculation process to calculate using,
Input the actual operation value of the combustion gas for performing the combustion, and calculate the current value of the input heat amount of the plurality of hot stove furnaces to calculate the current value of the input heat amount,
The blower which inputs the operation result value of the hot air supplied from the hot air furnace to the blast furnace and the operation result value of the cold air supplied to the hot air furnace, and calculates the present value of the whole blast heat quantity of the plurality of hot air furnaces Current heat value calculation process,
From the current value of the input heat amount and the current value of the blast heat amount, a thermal efficiency current value calculation step of calculating a current value of the thermal efficiency of the entire plurality of hot stoves,
When an operation for instructing the input device to correct the required input heat amount is performed by an operator, the current value of the input heat amount calculated by the input heat amount current value calculating step and the current amount of blast heat A reference value setting step for setting the current value of the blast heat quantity calculated by the value calculation step and the current value of the thermal efficiency calculated by the thermal efficiency current value calculation step as a reference value;
Whether or not the decrease in the current value of the blast heat amount calculated by the current value calculation step of the blast heat amount with respect to the reference value of the blast heat amount set by the reference value setting step exceeds the wind reduction and temperature reduction determination value. A wind-decreasing temperature-decision judging process,
Thermal efficiency decrease determination that determines whether or not a decrease in the current value of the thermal efficiency acquired by the current thermal efficiency value calculation step with respect to the reference value of the thermal efficiency set by the reference value setting step exceeds a thermal efficiency decrease determination value Process,
It is determined that the decrease in the current value with respect to the reference value of the blown heat amount exceeds the decrease in wind and temperature decrease determination value by the wind reduction and temperature reduction determination step, and the current value with respect to the reference value of the heat efficiency is determined by the thermal efficiency decrease determination step. When it is determined that the decrease exceeds the heat efficiency decrease determination value, an input heat amount correction coefficient calculation step for calculating an input heat amount correction coefficient;
The required input heat amount calculated in the required input heat amount calculation step is multiplied by the input heat amount correction coefficient calculated in the input heat amount correction coefficient calculation step, and the input heat amount in the next one cycle of each of the plurality of hot stoves is calculated. Let the computer execute the input heat amount calculation process to calculate,
The input heat amount correction coefficient calculation step calculates the input heat amount correction coefficient A [−] by the following equation (A).
A = (Qouts / Qouts-0) x (Qins-0 / Qins) (A)
Here, Qouts [kcal / min] is the current value of the blast heat quantity, Qouts-0 [kcal / min] is the reference value of the blast heat quantity, and Qins-0 [kcal / min] The reference value of the input heat amount, Qins [kcal / min] is the current value of the input heat amount.

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