KR20220089184A - System and method for operating of hot blast stove - Google Patents

Abstract

The present disclosure relates to a system for operating a hot stove facility and a method therefor. The operation system is an operation system of the hot stove facility, and includes a first temperature measuring device for measuring a dome temperature of the hot stove facility, a second temperature measuring device for measuring a heat storage room temperature of the hot stove facility, and the hot stove When the combustion operation of the facility is started, the control system may include a control system for controlling the operation of the hot stove facility so that the dome temperature and the heat storage room temperature satisfy a first target dome temperature and a first target heat storage room temperature, respectively. The control system may control a combustion flame temperature or a combustion time during a combustion operation such that the heat storage chamber temperature satisfies the first target heat storage chamber temperature.

Description

Operating system and method of hot stove facility {SYSTEM AND METHOD FOR OPERATING OF HOT BLAST STOVE}

The present disclosure relates to a system for operating a hot stove facility and a method therefor.

In the blast furnace process, hot air of about 1,100° C. or higher is supplied into the blast furnace through a tuyere at the bottom of the blast furnace through a hot blast stove. When the gas and air supplied from the hot stove burn to the combustion chamber to generate high-temperature combustion gas, and the high-temperature combustion gas moves to the heat storage chamber and stores heat in the heat storage material, the air supplied by blowing passes between the heat storage materials After absorbing the heat, it is blown through the tuyere at the bottom of the blast furnace. In this process, the exhaust gas (EG) discharged from the heat storage chamber of the hot stove after heat storage is discharged through a stack after sensible heat is recovered by the heat recovery facility.

Typically, the hot stove facility is operated based on a target dome temperature and a target flue gas temperature fixed to a value near the refractory limit temperature during combustion operation to blow hot air of a desired temperature to the blast furnace, and blowing During operation, the operation is performed in such a way that the temperature of the hot air is adjusted to the target temperature through mixing of the cold air.

Such a conventional hot stove operation method frequently generates unnecessary excess heat, causes a large amount of heat loss/heat radiation loss in the hot stove facility, and has a problem of increasing exhaust gas emission. In addition, since the target value of the dome temperature is used as a fixed value near the refractory limit temperature, a situation in which the temperature in the hot stove facility reaches near the refractory limit temperature frequently occurs, so there is a problem in stable life management of the hot stove equipment. .

An object to be solved through the embodiments is to provide a system for operating a hot stove facility and a method thereof for improving heat utilization efficiency in the hot stove facility and minimizing deterioration of the hot stove facility.

The operating system of the hot stove facility according to an embodiment for solving the above problems is a driving system of the hot stove facility, the first temperature measuring device measuring a dome temperature of the hot stove facility, and a heat storage room of the hot stove facility When the combustion operation of the second temperature measuring device for measuring a temperature and the hot stove facility is started, the dome temperature and the heat storage room temperature may satisfy a first target dome temperature and a first target heat storage room temperature, respectively. It may include a control system for controlling the operation of the facility. The control system may control a combustion flame temperature or a combustion time during a combustion operation such that the heat storage chamber temperature satisfies the first target heat storage chamber temperature.

The control system is configured to control the operating condition to adjust the combustion flame temperature or the combustion time so that the heat storage chamber temperature reaches the first target heat storage chamber temperature after the dome temperature reaches the first target dome temperature. can be controlled

The control system may include an operation for controlling the dome temperature to the first target dome temperature through air-fuel ratio control, and setting the heat storage chamber temperature to the first target heat storage chamber temperature through control of the combustion flame temperature or the combustion time. can be operated in parallel to control it.

The control system includes a flow rate at which the exhaust gas of the hot stove facility is recirculated to a combustion chamber, an excess air rate of the hot stove facility, a flow rate of oxygen supplied to the combustion chamber, a fuel co-firing rate of fuel gas supplied to the combustion chamber, and fuel By controlling at least one of the gas flow rates, the combustion flame temperature can be adjusted.

The operating system may be configured to: the first target dome temperature and the first target heat storage room according to a target hot air temperature based on a correlation between a temperature of the hot air supplied from the hot stove facility, the dome temperature, and the heat storage room temperature It may further include an analysis system for adaptively determining the temperature.

The analysis system obtains dome temperature data, heat storage room temperature data, and hot air temperature data of the hot stove facility through simulation or experiment, and the dome temperature data, the heat storage room temperature data, and the hot air temperature data It is possible to derive a linear model corresponding to the correlation through statistical analysis of the data.

The analysis system monitors a temperature change of the hot air according to a change in the dome temperature for the hot stove facility, and a temperature change of the hot air according to a change in the heat storage room temperature, and the temperature of the hot air is the dome temperature The correlation may be derived based on a section in which the temperature of the hot air changes linearly in response to a change in .

The analysis system derives, from the correlation, a second target dome temperature and a second target heat storage room temperature, which are lower limit temperatures allowed to supply hot air that satisfies the target hot air temperature under an operating condition that does not generate excessive heat storage, , by applying an offset corresponding to each of the second target dome temperature and the second target heat storage room temperature to derive the first target dome temperature and the first target heat storage room temperature.

The analysis system may derive the corresponding offset based on the characteristic factor of the hot stove facility, the blowing operation condition, and the characteristic factor of the heat storage material inside the heat storage chamber.

The second temperature measuring device may be located in a section that is 1/5 to 4/5 of the height of the heat storage room inside the heat storage room.

In addition, the operating method of the hot stove facility according to the embodiment includes the steps of, when a combustion operation is started, supplying a predetermined flow rate of fuel gas and air to the combustion chamber to increase the temperature of the hot stove facility, and controlling the air-fuel ratio of the hot stove managing the dome temperature of the facility to maintain a first target dome temperature, and controlling the combustion flame temperature or combustion time so that the heat storage room temperature of the hot stove facility reaches the first target heat storage room temperature have.

The controlling may be performed after the dome temperature reaches the first target dome temperature.

The managing and the controlling may be performed simultaneously.

The controlling may include a flow rate at which the exhaust gas of the hot stove facility is recirculated to the combustion chamber, an excess air rate of the hot stove facility, and oxygen supplied to the combustion chamber so that the heat storage chamber temperature reaches the first target heat storage chamber temperature. It may include the step of controlling at least one of the flow rate, the fuel co-firing rate of the fuel gas supplied to the combustion chamber, and the fuel gas flow rate.

The operating method may include, based on a correlation between a temperature of the hot air supplied from the hot stove facility, the dome temperature and the heat storage room temperature, the first target dome temperature and the first target heat storage room according to the target hot air temperature. The method may further include adaptively determining the temperature.

The adaptively determining step includes acquiring dome temperature data, heat storage room temperature data, and hot air temperature data of the hot stove facility through simulation or experiment, and the dome temperature data and the heat storage room temperature data and deriving a linear model corresponding to the correlation through statistical analysis on the hot air temperature data.

The adaptively determining step includes monitoring a temperature change of the hot air according to a change in the dome temperature for the hot stove facility, and a temperature change of the hot air according to a change in the temperature of the heat storage room, and the hot air Including the step of deriving the correlation based on a section in which the temperature of the dome changes linearly in response to a change in the temperature of the dome and a section in which the temperature of the hot air changes linearly in response to a change in the temperature of the heat storage room You may.

The adaptively determining may include, from the correlation, a second target dome temperature and a second target heat storage chamber, which are lower limit temperatures allowed to supply hot air that satisfies the target hot air temperature under an operating condition that does not generate excessive heat storage. deriving a temperature, and applying an offset corresponding to each of the second target dome temperature and the second target heat storage room temperature to derive the first target dome temperature and the first target heat storage room temperature can do.

The adaptively determining may further include deriving the corresponding offset based on the characteristic factor of the hot stove facility, the blowing operation condition, and the characteristic factor of the heat storage material inside the heat storage chamber.

According to the embodiment, it is possible to improve the heat use efficiency in the hot stove facility and to minimize the deterioration of the hot stove facility.

1 schematically shows a hot stove facility used in a blast furnace process.
2 schematically illustrates a system for operating a hot stove facility according to an embodiment.
3 illustrates a temperature change trend in the heat storage chamber as an example.
4 illustrates an example of a linear regression model between the hot air temperature - the dome temperature - the heat storage room temperature derived through statistical analysis in the operating system of the hot stove facility according to the embodiment.
5 is a graph illustrating an example of a change in the temperature of a hot air according to a change in the temperature of the dome.
6 schematically illustrates a method for controlling operation of a hot stove facility according to an embodiment.
7 illustrates an example of controlling a dome temperature, a heat storage room temperature, and a hot air temperature in the operation control method of a hot stove facility according to an embodiment.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. The present invention may be embodied in several different forms and is not limited to the embodiments described herein.

In order to clearly describe the embodiments of the present invention, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar elements throughout the specification.

In this document, terms including ordinal numbers such as "first", "second", etc. may be used to describe various elements, but the elements are not limited by these terms. These terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the second component may be referred to as the first component, and similarly, the first component may also be referred to as the second component.

1 schematically shows a hot stove facility used in a blast furnace process.

Referring to FIG. 1 , the hot stove facility 1 may include a combustion chamber 11 , a heat storage chamber 12 , a blower 13 , a mixed cooling chamber 14 , and the like.

During the combustion operation of the hot stove facility 1, fuel gas and air are supplied to the burner 11a of the combustion chamber 11, and they are combusted to generate high-temperature combustion gas. The fuel gas supplied to the combustion chamber 11 is blast furnace gas (BFG), which is a low-grade fuel gas with a relatively low calorific value, and coke oven gas (COG) with a high calorific value for flame safety and flame temperature maintenance. Coke Oven Gas) or a mixed gas mixed with natural gas may be used.

The high-temperature combustion gas generated by the combustion of air and fuel gas in the combustion chamber 11 moves to the heat storage chamber 12 through the dome 12a, and accordingly, the heat storage material in the heat storage chamber 12 by the high-temperature combustion gas Heat is stored in (eg refractory bricks with channel-shaped holes). After the heat storage, the exhaust gas (EG) discharged from the heat storage chamber 12 is discharged through a stack.

During the blowing operation of the hot stove facility 1 , the blower 13 supplies compressed air to the heat storage chamber 12 , and the air supplied from the blower 13 passes between the heat storage materials of the heat storage room 12 and heats up. absorbed and heated to a high temperature. The elevated temperature air, that is, hot air, passes through the combustion chamber 11 and the mixed cooling chamber 14 and is blown into a blast furnace (not shown) to be used as a heat source.

The hot stove facility 1 may alternately perform the above-described combustion operation and blowing operation, and may perform storage temperature and hot air supply.

The blast furnace facility may include a plurality (eg, 3 units or 4 units) of the above-mentioned hot air stove facilities 1 in order to continuously supply hot air to the blast furnace. In addition, the plurality of hot stove facilities 1 may sequentially start a combustion operation, and while some of the hot stove facilities perform a combustion operation, the remaining hot stove facilities may perform a blowing operation.

For example, in the case where the blast furnace facility is equipped with four hot stove facilities 1, while the two hot stove facilities 1 are in combustion operation, the remaining two hot stove facilities 1 are blown during the blowing process. can proceed. In addition, when the No. 1 and No. 2 hot stove facility 1 completes the combustion operation after the combustion operation is carried out in the No. 1 and No. 2 hot stove facility 1, the No. 3 hot stove facility 1 starts the combustion operation 2 When the No. and No. 3 hot stove facilities (1) start the combustion operation, and then the No. 2 hot stove facility (1) ends the combustion operation, the No. 4 hot stove facility (1) starts the combustion operation to start the combustion operation of No. 3 and In a manner in which the No. 4 hot stove facility 1 proceeds with the combustion operation, the hot stove facilities 1 from No. 1 to No. 4 may sequentially conduct the combustion operation. In this process, when the preceding hot stove facility (for example, while the No. 2 and No. 3 hot stove facilities are in combustion operation, the No. 1 hot stove facility is the preceding hot stove facility) ends the combustion operation, the blowing operation is continuously started. do.

Blast furnace operating conditions may change according to price fluctuations of fuel materials such as iron ore and coke/pulverized coal for economical operation. For example, if the coke input cost is relatively high compared to the pulverized coal injection (PCI), the blast furnace operating conditions may be adjusted to increase the pulverized coal injection amount and reduce the coke input amount in order to lower the production cost of molten iron. can

The flow rate and temperature of the hot air input to the blast furnace process are factors that have a very important influence on the amount of fuel used in the blast furnace process, the use ratio, energy efficiency, and the like. Therefore, when the blast furnace operating conditions are changed, appropriate hot air temperature control is required accordingly. For example, in the blast furnace process, when coke input cost is relatively high compared to pulverized coal blowing, so that the coke input amount is reduced and the pulverized coal injection amount is increased, it is necessary to introduce high-temperature hot air into the blast furnace.

Typically, the hot air temperature control of the hot stove facility 1 manages the dome temperature and the flue gas temperature based on the target dome temperature and the target flue gas temperature, which are fixed values (values near the refractory limit temperature) during combustion operation. and adjusting the hot air temperature to the target temperature through cold air mixing during the blowing operation. In this conventional hot air temperature control method, the target dome temperature is fixed to a value near the refractory limit temperature, and unnecessary excessive heat storage in the process of controlling the dome temperature based on this, and the temperature in the hot stove facility 1 is the refractory limit temperature There is a problem that the situation of reaching the vicinity occurs frequently. Excess heat storage causes a large amount of heat loss/radiation loss in the hot stove facility 1 , and acts as a factor to increase the exhaust gas emission. In addition, when a situation in which the temperature in the hot stove facility 1 reaches near the refractory limit temperature frequently occurs, the aging rate of the hot stove facility 1 is accelerated, thereby causing a problem in stable life management.

In addition, in the conventional hot air temperature control method, only the dome temperature and the exhaust gas temperature are used as management factors, so there is a problem in that the temperature condition inside the heat storage chamber cannot be sufficiently reflected. Accordingly, a situation in which the blowing operation is started in a thermal storage defect state in which the temperature inside the thermal storage chamber is not sufficiently increased may occur, resulting in reduced efficiency and economical efficiency of the blast furnace operation due to insufficient thermal storage.

An embodiment to be described later is intended to solve this problem, and a target temperature is set for not only the temperature in the dome 12a of the thermal storage chamber 12 but also the temperature inside the thermal storage chamber 12, the dome temperature and the thermal storage chamber The combustion operation condition of the hot stove facility 1 may be controlled based on the target temperature set for each temperature. In addition, when setting the target temperature for the dome temperature and the heat storage room temperature, the target temperature is adaptively adjusted according to the target hot air temperature, rather than setting the target temperature as a fixed value (for example, the temperature near the refractory limit temperature). can be set.

2 schematically illustrates a system for operating a hot stove facility according to an embodiment.

Referring to FIG. 2 , the operating system of the hot stove facility 1 may include a plurality of temperature measuring devices 21 to 24 , a correlation analysis system 60 , and a control system 50 .

The temperature measuring device 21 includes at least one temperature sensor disposed at different positions on the outlet side at which the hot air mixed with the cold air in the mixed cooling chamber 14 is discharged to the blast furnace (not shown), and through them, the final The temperature of the blown hot air can be measured. The temperature measuring device 21 includes at least one temperature sensor disposed above the heat storage chamber 12, that is, at different positions of the dome 12a, and through this, temperature can be measured. The temperature measuring device 23 includes at least one temperature sensor disposed at different positions in the middle of the heat storage chamber 12 , and may measure the temperature inside the heat storage chamber 12 through these temperature sensors. The temperature measuring device 24 includes at least one temperature sensor disposed at different positions in the lower portion of the heat storage chamber 12, and through these, the temperature of the water/exhaust gas at the bottom of the heat storage chamber 12 can be measured. .

FIG. 3 shows the temperature change trend in the heat storage chamber 12 as an example. Referring to FIG. 3 , the temperature change in the middle part of the heat storage room 12 (eg, 1/5 to 4/5 of the height of the heat storage room) during the heat storage operation and the blowing operation is changed in the heat storage room ( 12) It can be seen that it appears relatively large compared to the upper or lower part. Accordingly, in the embodiment, the temperature measuring device 23 for measuring the temperature inside the thermal storage chamber 12 is installed in the middle part of the thermal storage chamber 12 (for example, 1/ of the height of the thermal storage chamber 12) to be advantageous in controlling the temperature of the thermal storage chamber. 5 to 4/5), and based on the measured temperature of the heat storage room 12 (the internal space of the heat storage room 12 or the water in the heat storage room 12), the temperature of the heat storage room can be managed. can

Again, referring to FIG. 2 , the correlation analysis system 50 may derive a correlation between the hot air temperature and the dome temperature and a correlation between the hot air temperature and the heat storage room temperature through simulation or experiment.

For example, the correlation analysis system 50 calculates the dome temperature during operation of the hot stove, the heat storage room from the actual hot stove facility 1 or a pilot device (not shown) designed for simulation of the hot stove facility 1 . Temperature and hot air temperature data are acquired through simulation or actual measurement, and a linear model representing the correlation between the hot air temperature, the dome temperature, and the heat storage room temperature through statistical analysis thereof, that is, a linear regression equation, is obtained by the following Equation 1 can be derived as

[Equation 1]

Hot air temperature = a + b × heat storage room temperature + c × dome temperature

In Equation 1 above, a, b, and c are coefficients of the linear model, and the correlation analysis system 50 calculates the coefficients of the linear model according to the characteristics of the hot stove facility 1 through statistical analysis (a, b, c) can be derived. 4 illustrates an example of a linear regression model derived through statistical analysis in the correlation analysis system 50 . Referring to FIG. 4, the correlation analysis system 50 uses a statistical analysis method to calculate a linear model coefficient ( a, b, c) can be determined.

When the initial values of the linear model coefficients (a, b, c) of the linear regression model are determined, the correlation analysis system 50 then performs the linear model coefficients (a) through repeated learning reflecting the actual operating environment of the hot stove facility (1). , b, c) may be updated.

The correlation analysis system 50 also monitors the change in the hot air temperature according to the dome temperature change from the actual hot stove equipment 1 or a pilot device (not shown) designed for simulation of the hot stove equipment 1 (simulation). data or measured data), and a correlation between the hot air temperature and the dome temperature may be derived based on these. 5 is a graph illustrating an example of a change in the temperature of a hot air according to a change in the temperature of the dome. Referring to FIG. 5 , while the dome temperature is maintained above a predetermined value during blowing, the blown hot air temperature may be maintained at a desired value, but when the dome temperature falls below a predetermined value, the hot air temperature is linearly proportional to the dome temperature. gradually decreases. The correlation analysis system 50 analyzes the change in the hot air temperature according to the dome temperature, obtains a lower limit of the dome temperature for maintaining the hot air temperature at a constant value, and interpolates data in a section where the dome temperature falls below the lower limit. A correlation between the hot air temperature and the dome temperature can be derived through extrapolation.

The correlation analysis system 50 may also derive the correlation between the hot air temperature and the heat storage room temperature in a method similar to the method of deriving the correlation between the hot air temperature and the dome temperature. That is, the correlation analysis system 50 monitors the change in the hot air temperature according to the change in the temperature of the heat storage room from the actual hot stove facility 1 or a pilot device (not shown) designed for simulation of the hot stove facility 1 . (simulated data or measured data) may be acquired. In addition, the correlation analysis system 50 obtains a lower limit of the heat storage room temperature for maintaining the hot air temperature at a desired value during blowing from the acquired data, and interpolation/extrapolation of data in a section where the heat storage room temperature falls below this lower limit Through this, a correlation between the hot air temperature and the heat storage room temperature can be derived.

The correlations between the hot air temperature and the dome temperature, and the hot air temperature and the heat storage room temperature, derived by the above-mentioned methods, are the correlations between the hot air temperature, the dome temperature, and the heat storage room temperature under the condition that the cold wind operation is not considered. will be. Accordingly, the correlation equations derived by the above-described methods are the lower limit temperatures of the dome temperature and the heat storage room temperature (T _D2 , T _R2 ) that are allowed to blow hot air of a desired temperature to the blast furnace under a condition that does not generate excessive heat storage. can be used to derive Here, the lower limit temperatures T _D2 and T _R2 of the dome temperature and the heat storage room temperature may be used as target temperatures of the dome temperature and the heat storage room temperature at the end of the blowing operation.

Correlation analysis system 50, as described above, when the correlation between the hot air temperature and the dome lower limit temperature (T _D2 ) and the heat storage room lower limit temperature (T _R2 ) is defined, from this, the hot air temperature, the dome temperature and the heat storage room A correlation between the upper limit of the temperature (T _D1 , T _R1 ) may be derived. Here, the upper limits of the dome temperature and the heat storage room temperature (T _D1 , T _R1 ) are the upper limits of the dome temperature and the heat storage room temperature allowed to blow hot air of a desired temperature to the blast furnace under a condition that does not generate excessive heat storage. , can be used as the target temperature of the dome temperature and the heat storage chamber temperature at the end of the combustion operation.

Taking FIG. 5 as an example, the correlation analysis system 50 applies the offset (ΔT _D ) corresponding to the optimal dome temperature operating range to the relational expression indicating the correlation between the hot air temperature and the dome lower limit temperature (T _D2 ), A relational expression representing a correlation between the temperature and the dome upper limit temperature (T _D1 ) may be derived. In addition, the correlation analysis system 50 applies an offset corresponding to the optimum thermal storage room temperature operating range to the relational expression representing the correlation between the hot air temperature and the lower limit temperature of the heat storage room ( _{T R2} ) in a similar manner to this. Thus, a relational expression indicating a correlation between the hot air temperature and the upper limit temperature of the heat storage chamber (T _R1 ) can be derived. The offsets (ΔT _D , ΔT _R ) representing the optimal operating ranges for the dome temperature and the heat storage room temperature are the characteristic factors of the hot stove facility 1, the blowing operation conditions (blowing flow rate, blowing time, temperature change of blowing air, etc.) ), may be obtained based on factors such as specific heat and weight of the thermal storage material in the thermal storage chamber 12 .

Equation 2 below shows an example of deriving the offset ΔT _D between the lower limit temperature T _D2 and the upper limit temperature T _D1 of the dome temperature.

[Equation 2]

ΔT _D = T _D1 - T _D2 = (f _D ×F _air × t × Cp _air ×ΔT _air )/∑Cp _i m _i

In Equation 2 above, f _D is a correction factor, which varies depending on the facility characteristics of the hot stove facility 1, and may be improved to a high accuracy value through repeated calculations. In addition, F _air is the flow rate of the blowing air supplied during the blowing operation (including load oxygen), T is the blowing time, Cp _air is the specific heat of the blowing air supplied during the blowing operation (the value considering the load oxygen), and ΔT _air is the amount of the blowing air Temperature change (hot air temperature immediately after being discharged from the mixed cooling chamber 14 - blowing temperature just before being introduced into the thermal storage chamber 12), Cp _i is the specific heat of the thermal storage material in the thermal storage chamber 12, and m _i is the thermal storage chamber ( 12) It can correspond to the weight of the heat storage material, respectively.

Equation 3 below shows an example of deriving the offset _ΔTR between the lower limit temperature T _R2 and the upper limit temperature T _R1 of the heat storage chamber temperature.

[Equation 3]

ΔT _R = T _R1 - T _R2 = (f _R ×F _air × t × Cp _air ×ΔT _air )/∑Cp _i m _i

In Equation 2 above, f _R is a correction factor, which varies depending on the facility characteristics of the hot stove facility 1, and can be improved to a high accuracy value through repeated calculations. In addition, F _air is the flow rate of the blowing air supplied during the blowing operation (including load oxygen), T is the blowing time, Cp _air is the specific heat of the blowing air supplied during the blowing operation (the value considering the load oxygen), and ΔT _air is the amount of the blowing air Temperature change (hot air temperature immediately after being discharged from the mixed cooling chamber 14 - blowing temperature just before being introduced into the thermal storage chamber 12), Cp _i is the specific heat of the thermal storage material in the thermal storage chamber 12, and m _i is the thermal storage chamber ( 12) It can correspond to the weight of the heat storage material, respectively.

Correlation analysis system 50, as described above, the correlation between the target hot air temperature and the upper and lower limit temperatures of the dome temperature (T _D1 , T _D2 ), and the upper and lower limit temperatures of the target hot air temperature and the heat storage room temperature (T _R1 , When the correlation between T _R2 ) is defined, the defined correlation may be stored in a memory (not shown) in the form of a lookup table or a correlation expression. And, when the target hot air temperature for the operation of the hot air furnace facility 1 is input, the correlation analysis system 50 performs the upper and lower limits of the dome temperature corresponding to the target hot air temperature from the lookup table (T _D1 , T _D2 ) and , Read the upper and lower limit temperatures (T _R1 , T _R2 ) of the heat storage room temperature, or use a pre-stored correlation formula to determine the upper and lower limits of the dome temperature corresponding to the target hot air temperature (T _D1 , T _D2 ) and the heat storage room The upper and lower temperature limits (T _R1 , T _R2 ) can be directly calculated. Here, the correlation analysis system 50 may receive the target hot air temperature from the upper driving system or the manager terminal, or may receive information about the target temperature of the hot air from the manager through a user input device (not shown).

Correlation analysis system 50 corresponds to the target hot air temperature, the upper and lower temperature limits of the dome temperature (T _D1 , T _D2 ), and the upper and lower limit temperatures of the heat storage room temperature (T _R1 , T _R2 ) When the determined, based on this The upper and lower temperature limits of the dome temperature (T _D1 , T _D2 ) and the upper and lower limits of the temperature of the heat storage room (T _R1 , T _R2 ) may be transmitted to the control system 60 so that the hot air temperature control can be performed.

The control system 60 adaptively sets in response to the target hot air temperature from the correlation analysis system 50, the dome upper limit temperature (T _D1 ) and the dome lower limit temperature (T _D2 ) and the heat storage chamber upper limit temperature (T _R1 ) and heat storage When the actual lower limit temperature (T _R2 ) is received, the operation of the hot stove facility 1 can be controlled based on this.

First, the control system 60 controls the temperature of the hot air blown into the blast furnace through the temperature measuring devices 21 to 24 while the hot stove facility 1 is operating, the temperature of the dome at the top of the heat storage room 12, and the heat storage room. (12) It is possible to continuously receive and monitor the measured values of the internal temperature, the temperature of the flue gas/refractory material at the bottom of the heat storage chamber 12, and the like.

When the combustion operation is started, the control system 60 may supply fuel gas and air at a predetermined flow rate to the combustion chamber to gradually increase the temperature of the heat storage chamber 12 . Thereafter, when the temperature of the upper dome 12a of the heat storage chamber 12 gradually rises and converges to the dome upper limit temperature (T _D1 ) set as described above, the control system 60 operates in an air-fuel ratio condition in which excessive unburned does not occur. The dome temperature control may be performed so that the temperature of the dome 12a does not become higher than the dome upper limit temperature T _D1 by performing the combustion operation. In addition, the control system 60 may perform heat storage chamber temperature control to reach the internal temperature of the heat storage chamber 12 through the combustion flame temperature or combustion time control to reach the heat storage chamber upper limit temperature T _R1 set as described above. have. Here, the control system 60 determines a flow rate at which exhaust gas generated during the combustion operation is recirculated to the combustion chamber 11 , an excess air rate, a flow rate of oxygen supplied to the combustion chamber 11 , and a fuel of fuel gas supplied to the combustion chamber 11 . The combustion flame temperature of the combustion chamber 11 is controlled by controlling at least one factor of the co-firing rate (the ratio of the COG flow rate to the BFG flow rate) and the flow rate, or by adjusting the combustion time of the burner 11a, the heat storage chamber temperature is set to the upper limit. It can be controlled to reach the temperature T _R1 .

The higher the excess air rate of the combustion chamber 11, or the higher the exhaust gas flow rate recirculated to the combustion chamber 11, the lower the temperature of the combustion flame. may increase The internal temperature of the heat storage chamber 12 may be increased as the temperature of the combustion flame increases or the combustion time of the burner 11a increases. In consideration of this point, the control system 60 may control the combustion flame temperature or combustion time of the hot stove facility 1 so that the heat storage chamber temperature reaches the target upper limit temperature T _R1 .

The control system 60 controls the dome temperature to first reach the target dome upper limit temperature T _D1 and then to reach the target heat storage chamber upper limit temperature T _R1 during the combustion operation. can be performed. The control system 60 also controls operation to reach the dome upper limit temperature T _D1 targeting the dome temperature during the combustion operation, and a heat storage chamber upper limit temperature T _R1 to reach the targeted heat storage chamber temperature T R1 . Control operation may be performed simultaneously.

The control system 60 controls the hot stove facility 1 as described above so that both the dome temperature and the heat storage room temperature reach the target upper limit temperatures T _D1 and T _R1 during the combustion operation section of the hot stove facility 1 . ) control the combustion operation conditions (eg, combustion flame temperature), and when the combustion operation section ends, it may be switched to the blowing operation. On the other hand, when both the dome temperature and the heat storage chamber temperature reach the target upper limit temperatures (T _D1 , T _R1 ) before the predetermined combustion section is completed, the control system 60 operates the blast furnace through interlocking with other hot stove facilities. In the condition that the combustion operation is stopped and switched to the ventilation operation at a level that does not cause any problem in the blow rate flow, or the dome temperature and the heat storage room temperature are maintained at the upper limit temperature (T _D1 , T _R1 ) during the remaining combustion operation section, the minimum The combustion operation may be continued with the combustion gas flow rate.

When the blowing operation of the hot stove facility 1 is started, the control system 60 may control the flow rate of the cold air supplied to the mixed cooling chamber 14 to adjust the temperature of the hot air blown to the blast furnace to the target hot air temperature. On the other hand, while the blowing operation is in progress, the dome temperature and the heat storage room temperature of the hot stove facility 1 are continuously decreased, and when the dome temperature and the heat storage room temperature of the hot stove facility 1 are too low, even with the adjustment of the cold air flow rate It may not be possible to adjust the temperature of the hot air blown into the blast furnace to the desired temperature. Therefore, the control system 60 continuously monitors the dome temperature and the heat storage room temperature while the blowing operation is in progress, so that the dome temperature or the heat storage room temperature reaches the set lower limit temperature T _D2 , T _R2 as described above. In this case, the blowing operation can be stopped and the combustion operation can be resumed.

The operation system of the hot stove facility 1 includes an exhaust gas circulation pipe 31 for recovering the exhaust gas discharged from the hot stove facility 1 and recirculating it to the combustion chamber 11, and the exhaust gas circulation pipe 31 recovered through It may further include a flow rate control valve 41 for controlling the flow rate at which the exhaust gas is circulated to the combustion chamber 11 . The exhaust gas circulation pipe 31 may be connected between the front/rear end of the heat exchanger HE-1 that recovers heat from the exhaust gas discharged from the hot stove facility 1 and the pipe that supplies air to the combustion chamber 11 . . The control system 60 may control the opening degree of the flow control valve 41 to adjust the flow rate of the exhaust gas recirculated to the combustion chamber 11 .

The operation system of the hot stove facility 1 controls the oxygen supply pipe 32 for supplying oxygen to the combustion chamber 11 and the flow rate at which oxygen supplied through the oxygen supply pipe 32 is introduced into the combustion chamber 11 . It may further include a flow control valve 42 for regulating. The oxygen supply pipe 32 may be connected between an oxygen supply device such as a blower or a fan and a pipe for supplying air to the combustion chamber 11 . The control system 60 may control the opening degree of the flow control valve 42 to adjust the oxygen enrichment of the air introduced into the combustion chamber 11 .

The control system 60 may control the air supply device 16 that supplies air to the combustion chamber 11 of the hot stove facility 1 to adjust the excess air rate of the combustion chamber 11 . The control system 60 may control the co-firing rate or flow rate of the fuel gas through opening degree control of flow control valves (not shown) that control the BFG flow rate and the COG flow rate supplied to the combustion chamber 11 . The control system 60 may control the combustion time by controlling the combustion of the burner 11a in the combustion chamber 11 .

On the other hand, the control system 60 can control the exhaust gas circulation rate (exhaust gas circulation amount / (combustion air amount + exhaust gas circulation amount) at a level of 5% to 50% while the combustion operation is in progress, which controls the flame temperature and hot air temperature Considering all of them, it is suitable for efficient heat storage.In addition, the control system 60 controls the oxygen in the exhaust gas by appropriately adjusting the excess air ratio in order to minimize the generation of a large amount of unburned carbon monoxide (CO) in the initial stage after the combustion operation starts. The concentration of (O2) can be maintained at 2% or more.

6 schematically illustrates an operation control method of a hot stove facility according to an embodiment. The operation control method of FIG. 6 may be performed by the operation system of the hot stove facility 1 described with reference to FIGS. 1 and 2 .

Referring to FIG. 6 , when the target hot air temperature of the blast furnace operation is determined, the operating system according to the embodiment sets the target temperature of the dome temperature and the heat storage room temperature of the hot stove facility 1 according to the determination ( S10 ). In step S10 , the operating system controls the dome temperature and the heat storage room temperature based on the correlation between the target hot air temperature and the dome temperature defined by the correlation analysis system 50 and the correlation between the target hot air temperature and the heat storage room temperature. target temperatures (upper and lower limit temperatures of the dome temperature (T _D1 , T _D2 ), and upper and lower limit temperatures of the heat storage room temperature (T _R1 , T _R2 )) for

When the combustion operation of the hot stove facility 1 is started (S11), the operation system sets the flow rate of the fuel gas supplied to the combustion chamber 11 to a flow rate determined by the manager, and the internal temperature and the dome temperature of the heat storage chamber 12 is gradually increased (S12). Here, during the initial section in which the combustion operation is started and the dome temperature is gradually increased, the flow rate of air supplied to the combustion chamber 11 together with the fuel gas may be maintained at a predetermined initial value.

In the operation system, the temperature of the dome 12a gradually increases due to heat storage in the heat storage chamber 12 and converges to the dome upper limit temperature T _D1 set through the step S10. The air-fuel ratio (excess air) control for increasing the flow rate of air supplied to the combustion chamber 11 within a range in which excessive non-combustion does not occur in order to prevent the temperature from being higher than _D1 is performed (S13). Thereafter, the operating system controls the dome temperature to continuously maintain the dome temperature near the dome upper limit temperature (T _D1 ) through the air-fuel ratio control, and the temperature inside the heat storage chamber 12 through the control of the combustion flame temperature or the combustion time. The thermal storage chamber temperature control is performed to converge to the thermal storage chamber upper limit temperature (T _R1 ) set through step S10 (S14). In step S14 , the operating system determines the flow rate at which exhaust gas generated during the combustion operation is recirculated to the combustion chamber 11 , the excess air rate, the flow rate of oxygen supplied to the combustion chamber 11 (oxygen enrichment), and the fuel supplied to the combustion chamber 11 . The combustion flame temperature of the combustion chamber 11 is adjusted by controlling the combustion condition of at least one of the fuel co-firing rate of the gas and the fuel gas flow rate, or by adjusting the combustion time of the burner 11a, the heat storage chamber temperature is the upper limit temperature of the heat storage chamber. It can be controlled to reach (T _R1 ).

The operation control system determines that the dome temperature and the heat storage room temperature of the hot stove facility 1 are the target temperature (the dome upper limit temperature (T _D1 ), and the heat storage room upper limit temperature (T _R1 ) through the above-mentioned dome temperature control and heat storage room temperature control. ), the flow rate of the fuel gas supplied to the combustion chamber 11 is reduced to control the exhaust gas temperature so that the exhaust gas temperature discharged from the hot stove facility 1 is maintained near the set target exhaust gas temperature (S15).

Afterwards, when the hot stove facility 1 starts the blowing operation (S16), the operation system adjusts the flow rate of the cold air supplied to the mixed cooling chamber 14 to adjust the temperature of the hot air blown to the blast furnace to the target temperature, and then The temperature-controlled hot air is blown into the blast furnace (S17). When the blowing operation is continued, the heat stored in the heat storage chamber 12 is consumed, and the temperature inside the dome 12a and the heat storage chamber 12 is gradually decreased. The operation system continuously monitors the dome temperature and the heat storage room temperature while blowing hot air into the blast furnace through the step S17, and the dome temperature or the heat storage room temperature is the dome lower limit temperature (T _D2 ) or heat storage set through the step S10. When the actual lower limit temperature (T _R2 ) is reached, the blowing flow rate may be gradually reduced to prevent the hot air temperature blown to the blast furnace from being excessively lower than the target hot air temperature. When the blowing operation of the hot stove facility 1 is finished, the operation system waits until the next combustion operation of the hot stove facility 1 is started.

7 illustrates an example of controlling a dome temperature, a heat storage room temperature, and a hot air temperature in the operation control method of a hot stove facility according to an embodiment.

Referring to FIG. 7 , as in the operation control method of the hot stove facility according to the embodiment, the target temperature of the dome temperature and the heat storage room temperature according to the target hot air temperature (the upper and lower limits of the dome temperature (T _D1 , T _D2 ) , when the upper and lower limit temperatures (T _R1 , T _R2 )) of the heat storage room temperature are adaptively set and the dome temperature and the heat storage room temperature in the combustion section and the blowing section are managed based on this, the target hot air temperature throughout the blowing section It is possible to blow hot air that satisfies the

On the other hand, if the target temperature of the dome temperature is set to a value higher than the dome upper limit temperature (T _D1 ) suitable for the target hot air temperature and the dome temperature is managed based on this, hot air that satisfies the target hot air temperature is blown into the blast furnace throughout the blowing section. However, there is a problem in that heat loss increases as more cold air is used to match the hot air to the target temperature.

In addition, if the target temperature of the dome temperature is set to a value lower than the dome upper limit temperature (T _D1 ) suitable for the target hot air temperature and the dome temperature is managed based on this, the time for blowing hot air that satisfies the target hot air temperature is reduced. Accordingly, there is a problem in that it is difficult to operate a stable blast furnace.

In addition, if the dome temperature is managed according to the dome upper limit temperature (T _D1 ) adaptively set according to the target hot air temperature, but management of the heat storage room temperature is omitted, the temperature inside the heat storage room 12 is not sufficiently increased. In the bad state, when the dome temperature satisfies the dome upper limit temperature (T _D1 ) and the blowing operation is started, the time for blowing the hot air that satisfies the target hot air temperature is greatly reduced, and accordingly, there is a problem in stable blast furnace operation. .

According to the operating system and method of the hot stove facility according to the above-described embodiment, by setting the target temperature for managing the dome temperature during the combustion operation to an optimal value for the target hot air temperature, excessive heat storage occurs, and near the limit temperature of the refractory material driving can be minimized. Accordingly, there is an effect that heat loss and deterioration of the hot stove facility 1 are suppressed. In addition, by using not only the dome temperature but also the heat storage room temperature as a management factor during the combustion operation, it is possible to prevent the blowing of the heat from being started in a state where the temperature inside the heat storage room 12 is not sufficiently raised, thereby stably supplying hot air of a desired temperature. , it is possible to solve the problem of impairing the safety of the blast furnace operation by blowing hot air lower than the desired temperature to the blast furnace.

The drawings and detailed description of the described invention referenced so far are merely exemplary of the present invention, which are only used for the purpose of explaining the present invention, and are used to limit the meaning or limit the scope of the present invention described in the claims. it is not Therefore, those of ordinary skill in the art can easily select from it and replace it. In addition, those skilled in the art may omit some of the components described herein without degrading performance or add components to improve performance. In addition, those skilled in the art may change the order of the method steps described herein according to the process environment or equipment. Accordingly, the scope of the present invention should be determined by the claims and their equivalents rather than the described embodiments.

1: Hot stove equipment
11: combustion chamber
11a: burner
12: heat storage room
12a: dome
13: blower
14: mixed cold room
21, 22, 23, 24: temperature measuring device
31: exhaust gas circulation pipe
32: oxygen supply pipe
41, 42: flow control valve
50: correlation analysis system
60: control system

Claims (19)

As a driving system of a hot stove facility,
A first temperature measuring device for measuring the temperature of the dome of the hot stove facility,
A second temperature measuring device for measuring the temperature of the heat storage chamber of the hot stove facility, and
When the combustion operation of the hot stove facility is started, the control system for controlling the operation of the hot stove facility so that the dome temperature and the heat storage room temperature satisfy a first target dome temperature and a first target heat storage room temperature, respectively, ,
and the control system controls a combustion flame temperature or a combustion time during a combustion operation such that the heat storage chamber temperature satisfies the first target heat storage chamber temperature. According to claim 1,
The control system is configured to control the operating condition to adjust the combustion flame temperature or the combustion time so that the heat storage chamber temperature reaches the first target heat storage chamber temperature after the dome temperature reaches the first target dome temperature. Controlling, driving system. According to claim 1,
The control system may include an operation for controlling the dome temperature to the first target dome temperature through air-fuel ratio control, and setting the heat storage chamber temperature to the first target heat storage chamber temperature through control of the combustion flame temperature or the combustion time. A driving system that parallels driving for control. According to claim 1,
The control system includes a flow rate at which the exhaust gas of the hot stove facility is recirculated to a combustion chamber, an excess air rate of the hot stove facility, a flow rate of oxygen supplied to the combustion chamber, a fuel co-firing rate of fuel gas supplied to the combustion chamber, and fuel and controlling at least one of the gas flow rates to regulate the combustion flame temperature. According to claim 1,
Based on the correlation between the temperature of the hot air supplied from the hot stove facility and the dome temperature and the heat storage room temperature, the first target dome temperature and the first target heat storage room temperature are adaptively adjusted according to the target hot air temperature. The driving system further comprising an analysis system for determining. 6. The method of claim 5,
The analysis system obtains dome temperature data, heat storage room temperature data, and hot air temperature data of the hot stove facility through simulation or experiment, and the dome temperature data, the heat storage room temperature data, and the hot air temperature data A driving system for deriving a linear model corresponding to the correlation through statistical analysis on them. 6. The method of claim 5,
The analysis system monitors a temperature change of the hot air according to a change in the dome temperature for the hot stove facility, and a temperature change of the hot air according to a change in the heat storage room temperature, and the temperature of the hot air is the dome temperature and deriving the correlation based on a section in which the temperature of the hot air changes linearly in response to a change in the heat storage room temperature and a section in which the temperature of the hot air changes linearly in response to a change in the heat storage room temperature. 8. The method of claim 6 or 7,
The analysis system derives, from the correlation, a second target dome temperature and a second target heat storage room temperature, which are lower limit temperatures allowed to supply hot air that satisfies the target hot air temperature under an operating condition that does not generate excessive heat storage, , to derive the first target dome temperature and the first target heat storage room temperature by applying an offset corresponding to each of the second target dome temperature and the second target heat storage room temperature. 9. The method of claim 8,
and the analysis system derives the corresponding offset based on the characteristic factor of the hot stove facility, the blowing operation condition, and the characteristic factor of the thermal storage material inside the heat storage chamber. According to claim 1,
The second temperature measuring device is located in a section of the heat storage chamber that is 1/5 to 4/5 of the height of the heat storage room. A method of operating a hot stove facility, comprising:
When the combustion operation is started, supplying a predetermined flow rate of fuel gas and air to the combustion chamber to increase the temperature of the hot stove facility;
managing the dome temperature of the hot stove facility to maintain a first target dome temperature through air-fuel ratio control, and
and controlling the combustion flame temperature or combustion time so that the heat storage chamber temperature of the hot stove facility reaches a first target heat storage chamber temperature. 12. The method of claim 11,
The controlling is performed after the dome temperature reaches the first target dome temperature. 12. The method of claim 11,
The managing and the controlling are performed simultaneously. 12. The method of claim 11,
The controlling step is
A flow rate at which the exhaust gas of the hot stove facility is recirculated to a combustion chamber, an excess air rate of the hot stove facility, a flow rate of oxygen supplied to the combustion chamber, and the combustion chamber so that the heat storage chamber temperature reaches the first target heat storage chamber temperature A driving method comprising controlling at least one of a fuel co-firing rate of the supplied fuel gas and a fuel gas flow rate. 12. The method of claim 11,
Based on the correlation between the temperature of the hot air supplied from the hot stove facility and the dome temperature and the heat storage room temperature, the first target dome temperature and the first target heat storage room temperature are adaptively adjusted according to the target hot air temperature. The method of driving further comprising the step of determining. 16. The method of claim 15,
The adaptively determining step includes:
Acquiring dome temperature data, heat storage room temperature data, and hot air temperature data of the hot stove facility through simulation or experiment, and
and deriving a linear model corresponding to the correlation through statistical analysis of the dome temperature data, the heat storage room temperature data, and the hot air temperature data. 16. The method of claim 15,
The adaptively determining step includes:
Monitoring the temperature change of the hot air according to the change in the dome temperature for the hot stove facility, and the temperature change of the hot air according to the change in the temperature of the heat storage room, and
Deriving the correlation based on a section in which the temperature of the hot air linearly changes in response to a change in the temperature of the dome and a section in which the temperature of the hot air changes linearly in response to a change in the temperature of the heat storage room Including, a driving method. 18. The method of claim 16 or 17,
The adaptively determining step includes:
deriving a second target dome temperature and a second target heat storage room temperature, which are lower limit temperatures allowed to supply hot air that satisfies the target hot air temperature under an operating condition that does not generate excessive heat storage from the correlation; and
and deriving the first target dome temperature and the first target heat storage room temperature by applying an offset corresponding to each of the second target dome temperature and the second target heat storage room temperature. 19. The method of claim 18,
The adaptively determining step includes:
and deriving the corresponding offset based on the characteristic factor of the hot stove facility, the blowing operation condition, and the characteristic factor of the heat storage material inside the heat storage chamber.

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