JP5685899B2 - Combustion control device for hot stove and combustion control method for hot stove - Google Patents

Description

  The present invention relates to a combustion control apparatus for a hot stove for supplying hot air to a blast furnace or the like and a combustion control method therefor, and more particularly to control for optimizing the amount of input heat in the combustion period of the hot stove.

In the hot air furnace, the heat storage part in the furnace constructed from bricks and the like is heated by the combustion gas during the combustion period to accumulate heat energy, and in the subsequent air blowing period, cold air is passed through the furnace to exchange heat with the heat storage part. It is a facility that obtains hot air and supplies it to the blast furnace.
FIG. 4 is a schematic diagram showing a structure inside the furnace of the hot stove. As shown in FIG. 4, the hot stove 11 includes a combustion chamber 12 and a heat storage chamber 13. Inside the heat storage chamber 13, a heat storage brick 19 is stacked. The portion 14 is called a dome, and the portion 15 is called a lower part of the quartz brick. In the combustion period, in the combustion chamber 12, fuel gas is supplied from the supply port 16 and combustion air is supplied from the supply port 17 to be combusted, and the combustion exhaust gas is passed through the heat storage chamber 13 so that the internal heat storage brick 19 is removed. Heat. In the subsequent blowing period, cool air is passed from the supply port 18 to the heat storage chamber 13, and hot air is obtained by heat exchange with the heat storage brick 19. By installing a plurality of such hot air furnaces 11 and repeating the cycle of the combustion period and the air blowing period while shifting the phase for each furnace, hot air having a temperature and a flow rate necessary for blast furnace operation is supplied without interruption.

  FIG. 5 is a schematic diagram of a blowing temperature control system in the blowing period. There are cases where only one hot air furnace 11 is ventilated and two air ducts are simultaneously ventilated. In the former, by adjusting the opening of the mixed cooling butterfly valve MB to mix cold air, in the latter, one hot air furnace 11 is ventilated. The temperature of the hot air sent to the blast furnace is controlled by opening the cold air butterfly valve CB and adjusting the opening degree of the cold air butterfly valve CB of the other hot air furnace 11. In FIG. 5, the case where it ventilates simultaneously 2 units | sets, the hot stove 1 (1HS) and the hot stove 2 (2HS), is shown.

In the combustion period, it is necessary to input the amount of heat necessary to ensure the hot air temperature during the subsequent blowing period, but it is necessary to suppress the input heat amount as much as possible in order to save energy and reduce carbon dioxide emissions. However, when the temperature falls below 573 ° C., which is the transformation point temperature, the silica bricks cause rapid expansion and may collapse. Therefore, it is necessary to keep the temperature of the quartz brick lower portion 15 at the transformation point temperature or higher even at the end of the blowing period. Further, from the viewpoint of equipment protection, the dome 14 cannot be heated above a certain temperature. It is desirable to minimize the input heat amount under such constraints, and the determination of the input heat amount is an important issue in the combustion control of the hot stove.
For the operation of the hot stove, time is spent on a single operation that mixes hot air and cold air from one furnace to adjust the temperature and supply hot air to the blast furnace, and two of at least three hot air furnaces. There is a staggered parallel operation that staggers and ventilates at the same time, mixes the resulting hot air, and supplies it to the blast furnace.

  FIG. 6 is a conceptual diagram of staggered parallel operation. In FIG. 6, k is a discretized time and coincides with the furnace switching time. Hereinafter, the furnace switching interval is referred to as a period. The hot stove 1 (1HS in FIG. 5) finishes the blowing period at time k = 0 and enters the combustion period. The hot stove 2 (2HS in FIG. 5) ends the blowing period and enters the combustion period at time k = 1 with a delay of one period. The hot stove 3 (3HS in FIG. 5) ends the combustion period and enters the blowing period at time k = 0. The hot stove 4 (4HS in FIG. 5) ends the combustion period and enters the blowing period at time k = 1. Therefore, between k = 1 and k = 2, there are two air blowing states of 3HS and 4HS. Between k = 0 and k = 1, 3HS is a trailing furnace and has a higher heat level than 2HS preceding 3HS, and plays a role of supplying hot air at a higher temperature. Therefore, at k = 1, the hot air temperature from 3HS needs to be in a state higher than the set value of the blowing temperature to the blast furnace. Therefore, at k = 1, the hot air from 3HS and 4HS is higher than the blowing temperature set value. Therefore, 4HS waits until the time when the hot air temperature from 3HS drops to the setting value of the air temperature (arrow A in FIG. 6), and during that time, it is set to one 3HS air blow and mixes the cold air (mixed cold air) with the hot air from 3HS. By doing this, the air temperature is controlled.

  In the case of single operation, the hot air temperature from each furnace must always be higher than the air temperature setting value, but in the staggered parallel operation, the hot air from the preceding furnace lower than the air temperature setting value and the air temperature setting value Since the hot air from the succeeding furnace higher than the former is mixed and used, the level of the heat storage amount of the furnace (hereinafter referred to as the heat level) can be lowered compared to the former, and the thermal efficiency can be increased. Therefore, in the case of a large blast furnace, a staggered parallel operation is generally performed.

  Conventionally, as a method for controlling the amount of heat input to a hot stove, for example, there is a technique described in Patent Document 1. This technique determines the input heat amount by performing various corrections based on the necessary heat storage amount obtained in terms of heat theory. Specifically, the theoretical heat release during the blowing period is calculated from the next blowing conditions required by the blast furnace, and is used as the basis for the required heat storage, taking into account the heat error and the residual heat before the start of combustion. Obtain the required input heat. Furthermore, the required input heat amount is corrected so as to suppress fluctuations in the blowing temperature due to cold air temperature fluctuations, and the input heat amount to the hot air furnace in the current combustion period is determined.

JP-A-7-145416

However, in the conventional method for controlling the amount of heat input to a hot stove, the quality evaluation of the amount of heat input to the hot stove is performed based on fluctuations in the blast temperature that is also affected by operating conditions, so it is difficult to determine whether it is good or bad. In addition, since it is difficult to determine the state of excess or insufficient heat margin, the amount of heat input to the hot stove cannot be optimized, and there is a risk that the heat margin is excessive or insufficient.
Therefore, an object of the present invention is to provide a combustion control apparatus for a hot stove and a combustion control method thereof that can optimize the amount of heat input to each furnace.

In order to solve the above-mentioned problem, the combustion control device for a hot stove according to the present invention repeatedly performs a cycle of a combustion period and an air blowing period for each predetermined control period for a plurality of hot stoves, A combustion control device for a hot stove that supplies hot air of a desired temperature and flow rate to a blast furnace, which is the amount of heat that the hot stove has, and is necessary for supplying hot air of the temperature and flow rate required by the blast furnace. The amount of heat that indicates how much heat is more than the minimum amount of heat is defined as the heat margin, and the actual value of the index that represents the heat margin of each hot stove and the target value of the index that represents the heat margin of each hot stove Based on the difference, the feedback correction amount setting means for setting the feedback correction amount for the input heat amount in the previous combustion period of each hot stove, the amount of hot air to be supplied from the hot stove to the blast furnace in the previous blowing period, and the next time Ventilation In on the basis of the difference between the heat quantity of hot air to be supplied to the blast from the air heating furnace, further comprising a feed-forward correction amount setting means for setting the feed-forward correction amount for heat quantity in the previous combustion phase of the hot-air furnace, the By adding the feedback correction amount set by the feedback correction amount setting means and the feedforward correction amount set by the feedforward correction amount setting means to the input heat amount in the previous combustion period of the hot stove, each hot stove And an input heat amount setting means for setting an input heat amount in the current combustion period.

  Thereby, the amount of heat input to the hot stove can be set according to the difference between the actual value of the heat margin index and the target value of the heat margin index. Therefore, it is possible to appropriately set the amount of heat input to the hot stove in response to the change in the actual value of the heat margin index and the change in the target value of the heat margin index. It can be held in a hot stove. In addition, by setting a target value for the heat margin index, it is possible to easily determine whether the heat margin is excessive or insufficient. Therefore, the quality evaluation of the amount of heat input to the hot stove can be easily performed. Furthermore, since the speed type control is adopted when setting the input heat amount, the combustion control can be performed with a relatively simple configuration.

The amount of heat input to the hot stove can be set according to the difference between the blast furnace required heat amount in the previous blowing period and the blast furnace required heat amount in the next blowing period. Therefore, when the blast furnace required heat amount changes, the amount of heat stored in the hot stove can be quickly changed.

Further, the combustion control method for a hot stove according to the present invention performs a desired cycle for a blast furnace by repeatedly performing a cycle of a combustion period and an air blowing period for each of the plurality of hot stoves. A method for controlling the combustion of a hot stove that supplies hot air at a temperature and a flow rate, which is the amount of heat that the hot stove has and which is less than the minimum amount of heat required to supply the hot air at the temperature and flow rate required by the blast furnace. as many the amount of heat that indicates whether a heat and thermal margin, based on the difference between the target value of the index indicating the thermal margin of the actual values and the hot air oven of index indicating the thermal margin of the hot air oven, each The step of setting the feedback correction amount for the input heat amount in the previous combustion period of the hot stove, the heat amount of hot air to be supplied from the hot stove to the blast furnace in the previous blowing period, and the hot wind furnace to supply to the blast furnace in the next blowing period Heat Based on the difference between the amount of heat, and a step of setting the feed-forward correction amount for heat quantity in the previous combustion phase of the hot-air furnace, the heat input in the previous combustion phase of the hot-air furnace, the feedback correction amount And adding the feedforward correction amount to set the input heat amount in the current combustion period of each hot stove.
Thereby, it can be set as the combustion control method which can optimize the heat input into a hot stove, and can suppress the excess and deficiency of a thermal margin.

  According to the present invention, it is possible to set a feedback correction amount for the amount of heat input to the hot stove in the previous combustion period in response to various conditions of thermal margin, so that the amount of heat input to the hot stove can be optimized. Energy saving and reduction of carbon dioxide emissions.

It is a figure which shows the structure of the combustion control apparatus and related equipment of a hot stove in this embodiment. It is a block diagram which shows the specific structure of a combustion control apparatus. It is a figure for demonstrating the operation | movement of this embodiment. It is a schematic diagram which shows the structure in the furnace of a hot stove. It is a schematic diagram of the ventilation temperature control system in a ventilation period. It is a conceptual diagram of staggered parallel operation.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Constitution)
FIG. 1 is a diagram showing a configuration of a hot stove combustion control device and related equipment in the present embodiment.
In the figure, reference numeral 11 denotes a hot stove (hereinafter simply referred to as a furnace). As shown in FIG. 4, the hot stove 11 includes a combustion chamber 12 and a heat storage chamber 13. Inside the heat storage chamber 13, a heat storage brick 19 is stacked. The portion 14 is called a dome, and the portion 15 is called a lower part of the quartz brick. In the combustion period, in the combustion chamber 12, fuel gas is supplied from the supply port 16 and combustion air is supplied from the supply port 17 to be combusted, and the combustion exhaust gas is passed through the heat storage chamber 13 so that the internal heat storage brick 19 is removed. Heat. In the subsequent blowing period, cool air is passed from the supply port 18 to the heat storage chamber 13, and hot air is obtained by heat exchange with the heat storage brick 19. The hot air obtained at this time is supplied to the blast furnace. A plurality of such hot air furnaces 11 (for example, four as shown in FIG. 5) are connected, and as shown in FIG. 6, the combustion period and the air flow are controlled at predetermined control periods while shifting the phase for each furnace. By repeating the cycle of the period, hot air having a temperature and a flow rate necessary for blast furnace operation is supplied without interruption.

  As shown in FIG. 1, a blowing thermometer 31 that measures the temperature (blowing temperature) of hot air supplied to the blast furnace is attached to the outlet side of the hot stove 11. A dome thermometer 32 that measures the dome temperature is attached to the dome 14 of the hot stove 11, and a brick thermometer 33 that measures the brick temperature is attached to the lower part 15 of the quartz brick of the hot stove 11. Further, the mixed cooling butterfly valve MB is provided with a mixed cooling valve opening degree sensor 34 for detecting the opening degree of the mixed cooling butterfly valve MB. The cold air butterfly valve CB has an opening degree of the cold air butterfly valve CB. A cold air valve opening degree sensor 35 for detecting the above is attached.

  The output signals of the blower thermometer 31, the dome thermometer 32, the mixed cooling valve opening sensor 34, and the cold valve opening sensor 35 are input to the combustion control device 40. Further, the output signal of the blower thermometer 31 is input to the blower temperature control device 50. Although not shown in FIG. 1, the other hot air furnaces 11 are each provided with thermometers 31 to 33, and the other cold air butterfly valves CB are each provided with a cold air valve opening degree sensor 35. These output signals are input to the combustion control device 40 and the blower temperature control device 50.

The combustion control device 40 sets the amount of heat input to the hot stove 11 based on the input signal described above. Based on the set input heat amount, the opening degree of the gas valve 16a provided on the upstream side of the fuel gas supply port 16 (FIG. 5) of the hot stove 11 is controlled. Thereby, a gas flow rate or a gas calorie can be adjusted.
As described above, the control object of the combustion control device 40 is obtained by connecting the hot stove 11 of FIG. 4 as shown in FIG. In the hot stove 11, the staggered parallel operation is performed while repeating the combustion / air blowing cycle as shown in FIG. 6, and the setting of the input heat amount is performed at the discrete time of FIG. 6 prior to the combustion period of each furnace. Assume that k = 1, 2,... (timing indicated by a white square). The input heat amount setting process performed by the combustion control device 40 will be described in detail later.

  The blower temperature control device 50 performs the blower temperature control based on the input signal described above so that the blown temperature from the hot stove 11 becomes a blown temperature set value determined according to the amount of heat required for the blast furnace. Specifically, in the staggered parallel operation, the opening adjustment of the mixed-cooled butterfly valve MB in the case where only one hot air furnace 11 is ventilated so that the air temperature from the hot air furnace 11 becomes the air temperature setting value, And the temperature of the hot air which blows into a blast furnace is controlled by adjusting the opening degree of the cold wind butterfly valve CB in the case of ventilating two units simultaneously.

Next, the input heat amount setting process performed by the combustion control device 40 will be specifically described. FIG. 2 is a block diagram showing a specific configuration of the combustion control device 40.
In this combustion control device 40, the actual value of the index (thermal margin index) indicating the thermal margin of the hot stove 11 is compared with the target value of the thermal margin index, and the amount of heat input to the hot stove 11 in the previous combustion period is compared. A feedback correction amount is set, and a feedforward correction amount for the previous input heat amount is set according to a change in an index of heat amount (supplied heat amount index) to be supplied to the blast furnace corresponding to the load of the hot stove 11. Then, combustion control is performed by adding the correction amount to the previous input heat amount as the input heat amount to the hot stove 11 in the current combustion period. Here, the thermal margin of the hot stove 11 indicates how much heat each furnace has than the minimum amount of heat required to supply hot air at the temperature and flow rate required from the blast furnace. is there.

As shown in FIG. 2, the combustion control device 40 includes a thermal margin index result calculation unit 41, a subtractor 42, a thermal margin control unit 43, an input heat amount correction amount setting unit 44, an adder 45, and an adder. 46.
The thermal margin index result calculating unit 41 calculates and outputs an actual value (thermal margin index actual value) QY of an index representing the thermal margin. Here, as the heat margin index, the opening degree of the mixed cooling butterfly valve MB (mixing cooling valve opening degree) MBx at the end of the blowing of the furnace and the opening degree of the cooling air butterfly valve CB of the succeeding furnace at the same timing (cold air valve opening degree) ) CBx. As the mixed cooling valve opening degree MBx and the cold air valve opening degree CBx, signals detected by the mixed cooling valve opening degree sensor 34 and the cold valve opening degree sensor 35 are used, respectively.

The thermal margin index actual value QY is calculated by the following equation.
QY = f (MBx, CBx) (1)
Here, f () is a function for calculating a thermal margin index actual value QY using a variable in parentheses as a parameter. For example, a function shown below can be used.
_{QY = f MB · (MBx-} MBz) + f CB · (CBx-CBz) ......... (2)
Here, f _MB and f _CB are coefficients set in advance, respectively, and MBz and CBz are reference values of the respective opening degrees in the index calculation.

The subtracter 42 subtracts the thermal margin index actual value QY calculated by the thermal margin index actual calculation unit 41 from the target value (thermal margin index target value) QY _REF of the thermal margin index set by the operator to obtain the thermal margin index. The difference ΔQY is calculated. The calculated difference ΔQY is output to the thermal margin control unit 43.
The thermal margin control unit 43 sets a feedback correction amount ΔGq for the amount of heat input to the hot stove 11 based on the thermal margin index difference ΔQY (= QY _REF −QY) output from the subtractor 42.
ΔGq = Kq · (QY _REF −QY) (3)
Here, Kq is a control gain.

The input heat amount correction amount setting unit 44 adjusts the correction amount for the input heat amount to the hot stove 11 in the previous combustion period according to the difference between the blast furnace required heat amount in the previous blowing period and the blast furnace required heat amount in the next blowing period ( (Feed forward correction amount) ΔG _FF is set. In FIG. 6, when setting the input heat amount to 3HS with k = 2, that is, when the period from k = 2 to k = 4 is the “current combustion period”, k = 0 to k = 2. The period is the “last blowing period”, and the period from k = 4 to k = 6 is the “next blowing period”.

Here, the air temperature and the air flow rate from the hot stove 11 are used as an index representing the blast furnace required heat amount, and the feedforward correction amount ΔG _FF is calculated based on the following formula based on the index.
ΔG _FF = K _FF · (T1 · V1−T0 · V0) (4)
Here, K _FF is a correction gain. T0 is the previous blowing temperature, and T1 is the next blowing temperature. Furthermore, V0 is the previous blowing amount, and V1 is the next blowing amount.

In addition, although the case where the ventilation temperature and the ventilation volume from the hot stove 11 were used as an index showing the blast furnace required heat amount was described here, only the ventilation temperature is used as a simple means when the ventilation volume does not change greatly. It may be. That is, in this case, the feedforward correction amount ΔG _FF is calculated based on the following equation.
ΔG _FF = K _FFx · (T1−T0) (5)
Here, K _FFx is a correction gain.

The adder 45 adds the feedback correction amount ΔGq output in the thermal margin control unit 43, and a feed-forward correction amount .DELTA.G _FF output in heat quantity correction amount setting unit 44, the final correction amount for the previous heat input Is calculated.
The adder 46 adds the correction amount output from the adder 45 to the input heat amount Gx in the previous combustion period, and calculates the current input heat amount G. That is, the current input heat amount G is calculated by the following equation.
G = Gx + ΔG _FF + ΔGq (6)

In FIG. 6, when setting the amount of heat input to 1HS at k = 4, that is, when the period from k = 4 to k = 6 is the “current combustion period”, k = 0 to k = 2. The period is the “last combustion period”.
Based on the input heat amount G set in this way, the gas flow rate is adjusted by controlling the opening of the gas valve 16a of the hot stove 11.
In FIG. 2, the heat margin control unit 43 corresponds to the feedback correction amount setting unit, the input heat amount correction amount setting unit 44 corresponds to the feedforward correction amount setting unit, and the adders 45 and 46 serve as the input heat amount setting unit. It corresponds.

(Operation)
Next, the operation of this embodiment will be described.
Hereinafter, the case where the combustion control in this embodiment is applied when stably operating at an air flow rate of 8000 Nm ³ / min and an air temperature of about 1100 ° C. will be described. The change of the thermal margin index actual value QY in this case is shown in FIG. This is an example in which the combustion control in the present embodiment is applied with the thermal margin index target value QY _REF set to “11” at the 110th combustion (arrow α in FIG. 3).

When the operator sets the heat margin index target value QY _REF to “11” and applies the combustion control in the present embodiment at the 110th combustion frequency, the heat margin control unit 43 applies the heat margin index target value QY _REF and the heat The margin index actual value QY is compared, and the feedback correction amount ΔGq corresponding to the difference ΔQY is set based on the above equation (3). This feedback correction amount ΔGq is added to the amount of heat Gx input to the hot stove 11 in the previous combustion period, and the result is set as the amount of heat input G to the hot stove 11 in the current combustion period. Based on this input heat amount G, the gas flow rate of the hot stove 11 is controlled.

As a result of such combustion control, as shown in FIG. 3, after the 110th combustion, the thermal margin index is reduced to near the thermal margin index target value QY _REF and the variation is reduced. In this example, the thermal efficiency is improved by 0.6% compared with the number of times before the 110th combustion.
In this way, the thermal margin index actual value QY and the thermal margin index target value QY _REF are compared, and a change (feedback correction amount ΔGq) from the input heat amount Gx in the previous combustion period is set based on the difference. It is possible to set an appropriate input heat amount G corresponding to changes in the actual value of the heat margin index and the target value of the heat margin index, preventing the heat margin from becoming excessive or too small relative to the target value. can do. Further, it is possible to easily determine a state where the heat margin is excessive or insufficient with respect to the target value.

  In the present embodiment, the mixed cooling valve opening MBx and the cold air valve opening CBx are used as the heat margin index. The mixed cooling valve opening MBx is the amount of cold air mixed with hot air from the hot stove 11 in order to supply hot air having the temperature and flow rate required from the blast furnace, and the value does not depend on the hot stove load. The cold air valve opening CBx represents how much heat remains in the furnace (residual heat amount) after supplying hot air at the temperature and flow rate required from the blast furnace, and the value is also indicated in the hot air furnace load. Does not depend on. In this way, since the quality evaluation of the input heat amount can be performed using the heat margin index that is not affected by the operation conditions, the quality determination is easy.

Further, in the present embodiment, when the blast furnace required heat amount changes due to a change in the load of the hot stove 11 or the like, the input heat amount correction amount setting unit 44 changes the blast furnace required heat amount based on the above equation (4). Set the corresponding feedforward correction amount ΔG _FF . This feedforward correction amount ΔG _FF is added to the input heat amount Gx to the hot stove 11 in the previous combustion period together with the feedback correction amount ΔGq, and the result is set as the input heat amount G to the hot stove 11 in the current combustion period. The Based on this input heat amount G, the gas flow rate of the hot stove 11 is controlled.

Therefore, when the blast furnace required heat quantity in the next blowing period increases with respect to the blast furnace necessary heat quantity in the previous blowing period, the feedforward correction amount ΔG _FF becomes a positive value, and the current input heat quantity G is set to the previous input heat quantity Gx. To make the correction larger. On the other hand, when the blast furnace required heat amount in the next blowing period decreases with respect to the blast furnace necessary heat quantity in the previous blowing period, the feedforward correction amount ΔG _FF becomes a negative value, and the current input heat quantity G is compared with the previous input heat quantity Gx. To make it smaller. Therefore, the amount of heat stored in the hot stove 11 can be quickly changed according to the change in the blast furnace required heat amount.

(effect)
As described above, in the above embodiment, the actual value of the thermal margin index that does not depend on the operating conditions such as the hot stove load and the target value of the thermal margin index are compared, and input to the hot stove 11 directly based on the difference. Since the amount of heat is set, it is possible to easily determine the state of excess or insufficient heat margin, and it is possible to easily evaluate the input heat amount.

  Further, since the speed type control is adopted and the amount of change from the input heat amount in the previous combustion period is calculated and the input heat amount in the current combustion period is set, the combustion control can be performed with a relatively simple configuration. At this time, since the feedback correction amount for the input heat amount in the previous combustion period is set based on the difference between the actual value of the heat margin index and the target value of the heat margin index, feedback is performed when the heat margin is larger than the target value. When the correction amount is a negative value, the current input heat amount is made smaller than the previous value, and when the heat margin is smaller than the target value, the feedback correction amount is made a positive value and the current input heat amount can be made larger than the previous value. Therefore, excessive or insufficient heat margin can be suppressed.

Furthermore, since the target value is set for the heat margin index and the feedback correction amount is set, the hot stove can have a heat margin corresponding to the operation change. For example, when it is desired to rapidly increase the temperature of the blast furnace, the thermal margin of the hot stove can be increased in advance. Thereby, it is possible to raise the blowing temperature without causing insufficient heat.
As described above, it is configured to determine the amount of heat input to the hot stove by comparing the actual value of the heat margin index and the target value of the heat margin index. When the heat margin index target value is changed, it is possible to appropriately cope with the case where the heat margin index actual value changes due to other factors. Therefore, the hot stove can be maintained in an optimum heat margin state, and the fuel consumption can be suppressed.

In addition, when setting the input heat amount in the current combustion period, the blast furnace required heat amount in the previous blowing period and the blast furnace required heat amount in the next blowing period are compared, and based on the difference, feed forward with respect to the input heat amount in the previous combustion period Since the correction amount is set, when the blast furnace required heat amount changes, the amount of heat stored in the hot stove can be quickly changed according to the change.
In this way, the amount of heat input to the hot stove can be set according to various situations, so the amount of heat input to the hot stove can be optimized, and energy saving and reduction of carbon dioxide emissions can be achieved. Can do.

(Application examples)
In the above embodiment, the case where the mixed cooling valve opening and the cold air valve opening of the succeeding furnace are used as the heat margin index has been described. However, only the mixed cooling valve opening or only the cold air valve opening is used. Can also be used. Furthermore, it is also possible to use the amount of air blown from the cool air butterfly valve of the succeeding furnace, or the ratio of the amount of air blown from the mixed butterfly valve and the amount of air blown from the cold air butterfly valve.

  DESCRIPTION OF SYMBOLS 11 ... Hot stove, 12 ... Combustion chamber, 13 ... Thermal storage chamber, 14 ... Dome, 15 ... Lower part of quartz brick, 16 ... Supply port (fuel gas), 17 ... Supply port (combustion air), 18 ... Supply port (cold air) ), 19 ... Thermal storage bricks, 31 ... Blast thermometer, 32 ... Dome thermometer, 33 ... Brick thermometer, 34 ... Mixed cooling valve opening sensor, 40 ... Combustion control device, 41 ... Thermal margin index results calculation unit, 42 ... subtractor, 43 ... thermal margin control unit (feedback correction amount setting means), 44 ... input heat amount correction amount setting unit (feedforward correction amount setting means), 45 ... adder, 46 ... adder, 50 ... air temperature control apparatus

Claims (2)

A combustion control device for a hot stove that supplies hot air of a desired temperature and flow rate to a blast furnace by repeatedly performing a cycle of a combustion period and an air blowing period every predetermined control period for a plurality of hot stoves Because
The amount of heat that the hot air furnace has, which indicates how much heat it has than the minimum amount of heat necessary to supply hot air at the temperature and flow rate required from the blast furnace, is the heat margin,
Based on the difference between the actual value of the index representing the thermal margin of each hot stove and the target value of the index representing the thermal margin of each hot stove, the feedback correction amount for the input heat amount in the previous combustion period of each hot stove is set. Feedback correction amount setting means;
Based on the difference between the amount of hot air to be supplied from the hot blast furnace to the blast furnace in the previous blowing period and the amount of hot air to be supplied from the hot blast furnace to the blast furnace in the next blowing period, A feedforward correction amount setting means for setting a feedforward correction amount for the input heat amount,
By adding the feedback correction amount set by the feedback correction amount setting means and the feedforward correction amount set by the feedforward correction amount setting means to the input heat amount in the previous combustion period of each hot stove, A combustion control apparatus for a hot stove, comprising: input heat amount setting means for setting an input heat amount in the current combustion period of the furnace. Combustion control method for a hot stove to supply hot air with a desired temperature and flow rate to a blast furnace by repeatedly performing a cycle of a combustion period and an air blowing period every predetermined control period for a plurality of hot stoves Because
The amount of heat that the hot air furnace has, which indicates how much heat it has than the minimum amount of heat necessary to supply hot air at the temperature and flow rate required from the blast furnace, is the heat margin,
Based on the difference between the actual value of the index representing the thermal margin of each hot stove and the target value of the index representing the thermal margin of each hot stove, the feedback correction amount for the input heat amount in the previous combustion period of each hot stove is set. Steps,
Based on the difference between the amount of hot air to be supplied from the hot blast furnace to the blast furnace in the previous blowing period and the amount of hot air to be supplied from the hot blast furnace to the blast furnace in the next blowing period, Setting a feedforward correction amount for the input heat amount,
Adding the feedback correction amount and the feedforward correction amount to the input heat amount in the previous combustion period of each hot stove to set the input heat amount in the current combustion period of each hot stove A combustion control method for a hot stove.

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