JP7069999B2 - Converter parameter derivation device, converter parameter derivation method, and program - Google Patents

Description

The present invention relates to a converter parameter derivation device, a converter parameter derivation method, and a program, and is particularly suitable for use in operating a converter.

In the converter, decarburization (removal of carbon in the molten metal), temperature rise, removal of impurities in the molten steel, etc. are performed by blowing (blowing high-pressure oxygen into the furnace), and the molten steel after blowing is performed. Control is performed so that the temperature of the components inside and the temperature of the molten metal are within the target range. Therefore, in order to grasp the decarburized amount, the decarburized amount is measured from the carbon amount in the exhaust gas discharged from the converter.

Patent Document 1 describes that the decarburized amount is calculated by multiplying the integrated value of the flow rates of CO gas and CO ₂ gas in the exhaust gas in one charge by a correction coefficient. Here, the correction coefficient is for correcting the measurement error of the flow meter that measures the flow rate of the exhaust gas. The measurement error of the flow meter is mainly caused by the adhesion of dust to the flow meter.

Special Publication No. 61-15127 Japanese Unexamined Patent Publication No. 2012-11709 Japanese Unexamined Patent Publication No. 2017-8349

However, in the technique described in Patent Document 1, the correction coefficient is set as a constant, and there is no description of a specific derivation method of the value. Therefore, there is a possibility that the coefficient for correcting the measurement error of the flow meter that measures the flow rate of the exhaust gas does not become a value that reflects the state of the flow meter.

The present invention has been made in view of the above problems, and it is intended to be able to accurately derive a correction coefficient for correcting a measurement error of a flow meter that measures the flow rate of exhaust gas. The purpose.

The converter parameter derivation device of the present invention is a result acquisition means for acquiring actual data at the time of blowing in a converter, and a parameter derivation means for deriving an exhaust gas correction coefficient and an ingress CO ₂ flow rate based on the actual data. The actual data includes the actual value of the flow rate of the exhaust gas generated from the converter at the time of blowing at each time, and the flow rate of CO gas, CO ₂ gas, and O ₂ gas contained in the exhaust gas. The actual value at the time, the actual value at each time of the flow rate of the CO ₂ gas contained in the blown gas blown into the molten steel in the converter during smelting, and the actual value of the decarburized amount of the molten steel. The exhaust gas correction coefficient is a coefficient multiplied by the flow rate of the exhaust gas measured by the measuring means in order to correct the measurement error of the measuring means for measuring the flow rate of the exhaust gas, and the ingress CO ₂ flow rate. Is the flow rate of CO ₂ entering the exhaust gas duct through which the exhaust gas passes from the atmosphere, and the blown gas is only CO ₂ gas, or the main gas contained in the blown gas is CO ₂ gas. It is characterized by that.

The converter parameter derivation method of the present invention includes a performance acquisition step of acquiring performance data at the time of blowing in a converter, and a parameter derivation step of deriving an exhaust gas correction coefficient and an ingress CO ₂ flow rate based on the performance data. The actual data includes the actual value of the flow rate of the exhaust gas generated from the converter at the time of blowing at each time, and the flow rate of CO gas, CO ₂ gas, and O ₂ gas contained in the exhaust gas. The actual value at the time, the actual value at each time of the flow rate of the CO ₂ gas contained in the blown gas blown into the molten steel in the converter during smelting, and the actual value of the decarburized amount of the molten steel. The exhaust gas correction coefficient is a coefficient multiplied by the flow rate of the exhaust gas measured by the measuring means in order to correct the measurement error of the measuring means for measuring the flow rate of the exhaust gas, and the ingress CO ₂ flow rate. Is the flow rate of CO ₂ entering the exhaust gas duct through which the exhaust gas passes from the atmosphere, and the blown gas is only CO ₂ gas, or the main gas contained in the blown gas is CO ₂ gas. It is characterized by that.

The program of the present invention is characterized in that a computer functions as each means of the converter parameter derivation device.

According to the present invention, it is possible to accurately derive a correction coefficient for correcting a measurement error of a flow meter that measures the flow rate of exhaust gas.

FIG. 1 is a diagram showing an example of the configuration of a converter facility and a converter control device. FIG. 2 is a flowchart illustrating an example of processing of the converter control device.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing an example of the configuration of the converter equipment 100 and the converter control device 200. Here, the configuration for measuring the converter 101 and the exhaust gas generated from the converter 101 as the converter equipment 100 will be mainly described.
First, the outline of blowing smelting (primary smelting) in the converter facility 100 will be described. The contents of the converter facility 100 and blowing (primary refining) can be realized by known techniques, and are not limited to those described below.

In FIG. 1, first, a main raw material such as hot metal and scrap is charged into the converter 101, and then an auxiliary raw material such as quicklime is charged into the converter 101. In the following description, the main raw material and the auxiliary raw material will be referred to as molten steel 102, if necessary. The slag 103 shown in FIG. 1 is not generated at this stage. After the molten steel 102 is pre-refined, the temperature, carbon concentration, etc. of the molten steel 102 are measured by the sublance 104. In the following description, this measurement will be referred to as a blow-in start measurement as necessary.

After that, O ₂ gas is blown from the main lance 105 and blown gas (CO ₂ gas or the like) is blown into the furnace from the bottom of the furnace to start blowing, and the molten steel 102 is agitated. As a result, carbon, silicon, phosphorus and the like contained in the molten steel 102 are oxidized and removed, and the temperature of the molten steel 102 rises. Further, due to this oxidation reaction, slag 103 in which silicon, phosphorus and the like are incorporated is generated on the upper portion of the molten steel 102. After that, the amount of O ₂ gas blown by the main lance 105 is reduced, and the temperature, carbon concentration, etc. of the molten steel 102 are measured by the sub lance 104. In the following description, this measurement will be referred to as an intermediate measurement as necessary.

In addition, the target values (or target range) of the temperature and carbon concentration of the molten steel 102 at the end of smelting are set, and the temperature and carbon concentration of the molten steel 102 at the end of smelting are set to the target values (or within the target range). In addition, the blowing by the main lance 105 is controlled. Then, when the blowing by the main lance 105 is completed, the temperature, carbon concentration, etc. of the molten steel 102 are measured by the sub lance 104. In the following description, this measurement will be referred to as blow-off measurement as necessary.

After that, the molten steel 102 is taken out from the converter 101 and transferred to a next step (secondary refining step or the like). In this embodiment, one charge is configured from the start to the end (blowing stop) of blowing.

In FIG. 1, a skirt 106, a hood 107, and an exhaust gas duct 108 are arranged above the converter 101. The skirt 106 and the hood 107 are arranged so that the inner peripheral surface of the skirt 106 and the outer peripheral surface of the hood 107 face each other, and the height position of the skirt 106 can be changed.

The blown gas component analyzer 109 analyzes the components of the blown gas blown into the converter 101 from the bottom of the converter 101. In the present embodiment, the case where the constituent components of the gas and the concentration of each constituent component can be obtained as a result of the component analysis will be described as an example. The blow gas flow meter 110 measures the flow rate of the blow gas blown into the converter 101 from the bottom of the converter 101. The exhaust gas component analyzer 111 analyzes the components of the exhaust gas from the converter 101. The exhaust gas flow meter 112 measures the flow rate of the exhaust gas from the converter 101. The blown gas component analyzer 109 and the exhaust gas component analyzer 111 can be realized by a known component analyzer that analyzes the gas component, and the exhaust gas flow meter 112 and the exhaust gas flow meter 110 are gas. Since it can be realized by a known flow meter that measures the flow rate, detailed description thereof will be omitted here.

The converter control device 200 is an application example of a converter parameter derivation device that performs processing including derivation of a correction coefficient for the measured value of the exhaust gas flow meter 112 and derivation of the flow rate of CO ₂ gas entering the exhaust gas duct 108 from the atmosphere. Is. The hardware of the converter control device 200 is realized by using, for example, a CPU, a ROM, a RAM, an HDD, an information processing device having various interfaces, a PLC (Programmable Logic Controller), or dedicated hardware.

FIG. 1 shows an example of the functional configuration of the converter control device 200. Hereinafter, an example of the function of the converter control device 200 of the present embodiment will be described.
<Data acquisition unit 201>
The data acquisition unit 201 acquires various measurement data from the converter equipment 100. The measurement data includes blown gas composition data, blown gas flow rate data, exhaust gas composition data, exhaust gas flow rate data, carbon concentration data in molten steel, carbon content data in auxiliary raw materials, and molten steel amount data.

The blown gas composition data includes the components of the blown gas measured by the blown gas component analyzer 109 and the concentration (mass%) of each component. In the present embodiment, the data acquisition unit 201 acquires at least the concentration of CO ₂ gas as the blown gas configuration data in a predetermined sampling cycle within a period of one charge. As a result, time-series data on the concentration of CO ₂ gas contained in the blown gas can be obtained.

The blown gas flow rate data includes the flow rate of the blown gas (Nm ³ / s) measured by the blown gas flow meter 110. In the present embodiment, the data acquisition unit 201 acquires the flow rate of the blown gas in a predetermined sampling cycle within the period of one charge. As a result, time-series data of the flow rate of the blown gas can be obtained.

The exhaust gas composition data includes the components of the exhaust gas measured by the exhaust gas component analyzer 111 and the concentration (mass%) of each component. In the present embodiment, the data acquisition unit 201 acquires at least the concentrations of CO ₂ gas, CO gas, and O ₂ gas as components contained in the air in a predetermined sampling cycle within a period of one charge. This provides time-series data on the concentrations of CO ₂ gas, CO gas, and O ₂ gas contained in the exhaust gas.

The exhaust gas flow rate data includes the exhaust gas flow rate (Nm ³ / s) measured by the exhaust gas flow meter 112. In the present embodiment, the data acquisition unit 201 acquires the flow rate of the exhaust gas in a predetermined sampling cycle within the period of one charge. As a result, time-series data of the flow rate of the exhaust gas can be obtained.

The carbon concentration data in the molten steel includes the carbon concentration (% by mass) in the molten steel 102 measured using the sublance 104 in the intermediate measurement and the carbon in the molten steel 102 measured using the sublance 104 in the blowout measurement. Includes concentration (% by mass).

The carbon amount data in the auxiliary material includes the mass (kg) of carbon contained in the auxiliary material charged into the converter 101. For example, it is included in the type charged into the converter 101 based on the concentration of carbon determined for each type of auxiliary material charged into the converter 101 and the mass of the type charged into the converter 101. The mass of carbon can be obtained for all types of auxiliary materials charged into the converter 101, and by integrating them, the mass of carbon contained in the auxiliary materials charged into the converter 101 can be obtained. can.

The molten steel amount data includes the mass (kg) of the molten steel 102 in the converter 101. In the present embodiment, it is assumed that the molten steel amount data includes the mass of the molten steel 102 in the converter 101 measured after blowing off. Instead of the mass of the molten steel 102 in the converter 101 measured after blowing off, for example, the mass of the molten steel 102 in the converter 101 measured before the start of blowing may be used.

<Parameter derivation unit 202, parameter storage unit 203>
The parameter derivation unit 202 uses the measurement data acquired by the data acquisition unit 201 to obtain a correction coefficient for the measured value of the exhaust gas flow meter 112 and the flow rate of CO ₂ gas entering the exhaust gas duct 108 from the atmosphere (Nm ³ / s). ) And is derived.
Since dust flows into the exhaust gas duct 108 together with the exhaust gas, the dust adheres to the exhaust gas flow meter 112. This dust may cause a measurement error in the flow rate of the exhaust gas measured by the exhaust gas flow meter 112. The correction coefficient for the measured value of the exhaust gas flow meter 112 is a coefficient multiplied by the flow rate of the exhaust gas measured by the exhaust gas flow meter 112 in order to correct this measurement error. In the following description, the correction coefficient for the measured value of the exhaust gas flow meter 112 will be referred to as an exhaust gas correction coefficient, if necessary. The exhaust gas correction coefficient is a dimensionless quantity. Further, in the following description, the flow rate of CO ₂ gas entering the exhaust gas duct 108 from the atmosphere is referred to as an entering CO ₂ flow rate as necessary.

In the present embodiment, the parameter derivation unit 202 derives the exhaust gas correction coefficient η and the integrated value Σ x _CO2 (t) of the ingress CO ₂ flow rate x _CO2 (t) by the following equations (1) and (2). do.

Here, f (t) is the flow rate of the exhaust gas at time t. f _CO2 (t) is the flow rate of CO ₂ gas contained in the exhaust gas at time t. f _CO (t) is the flow rate of the CO gas contained in the exhaust gas at time t. f _O2 (t) is the flow rate of the _O2 gas contained in the exhaust gas at time t.
The flow rate f (t) at time t of the exhaust gas is a value at time t of the time series data of the flow rate of the exhaust gas. In addition, 0.04 / 79 of the formula (2) is a conversion coefficient for converting the flow rate of N ₂ gas into the flow rate of CO ₂ gas (the abundance ratio of CO ₂ gas in the atmosphere to the abundance ratio of N ₂ gas in the atmosphere). ).

The flow rate f _CO2 (t) of the CO ₂ gas contained in the exhaust gas at time t is the value obtained by dividing the value at time t of the time series data of the concentration of CO ₂ gas contained in the exhaust gas by 100 and the flow rate of the exhaust gas. It is obtained by multiplying the value of the series data at time t. The flow rate f _CO (t) of the CO gas contained in the exhaust gas at time t is the value obtained by dividing the value at time t of the time series data of the concentration of CO gas contained in the exhaust gas by 100 and the time series data of the flow rate of the exhaust gas. It is obtained by multiplying the value at time t of. The flow rate f _O2 (t) of the O ₂ gas contained in the exhaust gas at time t is the value obtained by dividing the value at time t of the time series data of the concentration of the O ₂ gas contained in the exhaust gas by 100 and the flow rate of the exhaust gas. It is obtained by multiplying the value of the series data at time t.

α (t) is the flow rate of components other than CO ₂ , CO, O ₂ , and N ₂ contained in the air at time t. In the present embodiment, the components other than CO ₂ , CO, O ₂ , and N ₂ contained in the air are few, and the components are not considered, and α (t) is always 0 (zero). This is the same except for equation (2).
y _CO2 (t) is the flow rate of the CO ₂ gas contained in the blown gas at time t. The flow rate y _CO2 (t) of the CO ₂ gas contained in the blown gas at time t is the value obtained by dividing the value at time t of the time series data of the concentration of the CO ₂ gas contained in the blown gas by 100 and the blown gas. It is obtained by multiplying the time-series data of the flow rate of the filling gas with the value at time t.

t1 is the time of the intermediate measurement, and t2 is the time of the measurement at the time of blowing off. Therefore, the integrated value Σ x _CO2 (t) of the approach CO ₂ flow rate x _CO2 (t) is the integrated value from the time t1 of the intermediate measurement of the approach CO ₂ flow rate x _CO2 (t) to the time t2 of the blow-off measurement. ..

C is the actual value [kg] of the decarburized amount in the charge to be measured. In the following description, the actual value of the decarburized amount in the charge to be measured is referred to as the actual decarburized amount as necessary. The actual decarburized amount C is calculated by the following equation (3).

Here, CM is the concentration of carbon in the molten steel 102 measured using the _sublance 104 in the intermediate measurement of the charge to be measured. CE is the concentration of carbon in the molten steel 102 measured with the _sublance 104 in the blowout measurement. W is the mass of the molten steel 102 in the converter 101. _CS is the mass of carbon contained in the auxiliary raw material charged into the converter 101 in the charge to be measured.

The right side of the equation (3) is in the auxiliary raw material contained in the molten steel 102 from the mass of carbon removed from the molten steel 102 between the time t1 of the intermediate measurement and the time t2 of the blow-off measurement in the charge to be measured. It is an equation showing that the value obtained by subtracting the mass of carbon in the charge is the amount of decarburization between the time t1 of the intermediate measurement and the time t2 of the blow-off measurement in the charge.

In the equation (1), the mass of carbon contained in the exhaust gas in the charge to be measured is the integrated value between the time t1 of the intermediate measurement and the time t2 of the measurement at the time of blowing off, and the carbon entering the exhaust gas duct 108 is obtained. From the time t1 of the intermediate measurement to the time t2 of the blow-off measurement of the integrated value of the mass between the time t1 of the intermediate measurement and the time t2 of the blow-off measurement and the mass of the carbon blown into the converter 101. It is an equation showing that the value obtained by subtracting the sum of the integrated values during the period is the amount of decarburization between the time t1 of the intermediate measurement and the time t2 of the blow-off measurement in the charge. In addition, 12 / 22.4 in the equation (1) is a coefficient for converting the flow rate of each gas into the mass of carbon.

In the technique described in Patent Document 1, the decarburization amount is calculated by considering only the integrated value of the mass of carbon contained in the exhaust gas between the time t1 of the intermediate measurement and the time t2 of the blowout measurement. However, since CO ₂ gas is blown during smelting, it is not appropriate to derive the decarburized amount including the mass of carbon contained in this CO ₂ gas.

Further, the present inventors pay attention to the flow of air in the gap between the converter 101 and the skirt 106 at the time of blowing, and depending on the operating conditions, this flow passes through the gap between the converter 101 and the skirt 106. It was found that the flow flows from the outside toward the inside of the skirt 106, and conversely, the flow flows out from the gap between the converter 101 and the skirt 106 toward the outside. Then, the present inventors investigated the flow rate of the atmosphere in the flow rate of the exhaust gas. As a result, the ratio of the atmospheric flow rate to the exhaust gas flow rate is about 30%, and the flow of the atmosphere flowing from the outside toward the inside of the skirt 106 through the gap between the converter 101 and the skirt 106 cannot be ignored. I got the finding. That is, it is not appropriate to derive the decarburized amount including the mass of carbon contained in this atmosphere.

From the above, in the present embodiment, as shown in equation (1), from the integrated value of the mass of carbon contained in the exhaust gas, the integrated value of the mass of carbon entering the exhaust gas duct 108, and from the bottom of the furnace to the furnace . The amount of decarburized is derived using the value obtained by subtracting the sum of the integrated value of the mass of carbon blown into the inside . By doing so, the exhaust gas correction coefficient η can be obtained accurately.

In the equation (1), the flow rate y _CO2 (t) of the CO ₂ gas contained in the blown gas at time t is obtained by using the measured value of the blown gas flow meter 110. Generally, the blown gas flow meter 110 is placed in an environment with less dust than the exhaust gas flow meter 112. Therefore, the flow rate y _CO2 (t) of the CO ₂ gas contained in the blown gas at time t is not corrected by using a correction coefficient such as the exhaust gas correction coefficient η.

In equation (1), the exhaust gas correction coefficient η and the integrated value Σ x _CO2 (t) of the ingress CO ₂ flow rate x _CO2 (t) can be obtained, but what needs to be finally obtained is the ingress CO ₂ flow rate x. It is not the integrated value of _CO2 (t) Σ x _CO2 (t), but the ingress CO ₂ flow rate x _CO2 (t). Therefore, the present inventors pay attention to the fact that the N ₂ gas is an inert gas, and express the ingress CO _{2 flow rate x CO 2 (t) as follows, and express the ingress CO 2 flow rate} x _CO 2 (t). It was found that not only the integrated value of Σ x _CO 2 (t) but also the ingress CO ₂ flow rate x _CO 2 (t) can be obtained.

First, it is assumed that the concentration of N ₂ gas contained in the exhaust gas is also measured by the exhaust gas component analyzer 111. In this case, the flow rate f _N2 (Nm ³ / s) of the N ₂ gas contained in the exhaust gas at time t is expressed by the following equation (4).

The flow rate f _N2 (t) of the N ₂ gas contained in the exhaust gas at time t is the value obtained by dividing the value at time t of the time series data of the concentration of the N ₂ gas contained in the exhaust gas by 100 and the flow rate of the exhaust gas. It is obtained by multiplying the value of the series data at time t.
Since the N ₂ gas is an inert gas, the N ₂ gas measured by the exhaust gas component analyzer 111 is equal to the flow rate x _N 2 of the N ₂ gas flowing in from the outside through the gap between the converter 101 and the skirt 106. Can be regarded as. Therefore, the following equation (5) holds. Then, the following equation (6) holds from the abundance ratio of N ₂ gas and CO ₂ gas in the atmosphere.

0.04 / 79 in the equation (6) is a conversion coefficient for converting the flow rate of N ₂ gas into the flow rate of CO ₂ gas. From the equations (5) and (6), the flow rate x _N2 (t) of the _N2 gas flowing in from the outside through the gap between the converter 101 and the skirt 106 at time t is eliminated and included in the exhaust gas. When the flow rate f _N2 (t) of the N ₂ gas at time t is obtained and substituted into the equation (4), the following equation (7) is obtained.

Equation (7) expresses the ingress CO ₂ flow rate x _CO2 (t) at time t. Equation (2) is the sum of the right side and the left side of equation (7) from the time t1 of the intermediate measurement to the time t2 of the blowout measurement.

Equations (1) and (2) are equations for calculating the integrated value from the time t1 of the intermediate measurement to the time t2 of the blow-off measurement. Therefore, in order to obtain the exhaust gas correction coefficient η by the equations (1) and (2), it is necessary to obtain the measurement data in one charge. When the measurement data for one charge is obtained, the parameter derivation unit 202 sets the exhaust gas correction coefficient η and the integrated value Σ x _CO2 (t) of the approach CO ₂ flow rate x _CO2 (t) as the parameters for the charge (1). ) And (2).

The measurement error due to dust in the exhaust gas flow meter 112 does not change abruptly, but changes gradually. Therefore, the exhaust gas correction coefficient η does not necessarily have to be obtained in real time.
On the other hand, in the present embodiment, the temperature and carbon concentration of the molten steel 102 are sequentially estimated, and the estimated results are used to control the temperature and carbon concentration of the molten steel 102 to reach the target values (main lance 105? The flow rate of O ₂ gas that needs to be blown) is obtained, and the converter 100 is controlled to be operated with the obtained operation amount. Therefore, it is necessary to obtain the ingress CO ₂ flow rate x _CO 2 (t) in real time.

Therefore, in the present embodiment, the parameter derivation unit 202 has the exhaust gas correction coefficient η derived by the equations (1) and (2) and the integrated value Σ x _CO2 (t) of the ingress CO ₂ flow rate x _CO2 (t). , The exhaust gas correction coefficient η is stored in the parameter storage unit 203.

The parameter derivation unit 202 uses the exhaust gas correction coefficient η derived from the parameter storage unit 203 in the previous charge and the measurement data acquired by the data acquisition unit 201 in the current charge (charge to be measured) (7). From the equation, the ingress CO ₂ flow rate x _CO2 (t) at each time t of the current charge is derived.

Then, the parameter derivation unit 202 uses the exhaust gas correction coefficient η derived in the previous charge and the measurement data acquired by the data acquisition unit 201 in the current charge to present the flow rate of each component contained in the exhaust gas. The correction value at each time t of the charge of is derived. Specifically, in the present embodiment, the parameter derivation unit 202 has a correction value f ′ (t) for the flow rate of the exhaust gas at time t, and a correction value f _O2 ′ (t) for the flow rate of the O ₂ gas contained in the exhaust gas at time t. , The correction value f _CO 2 ′ (t) of the flow rate of the CO ₂ gas contained in the exhaust gas at time t, and the correction value f _CO ′ (t) of the flow rate of the CO gas contained in the exhaust gas at time t are as follows. It is derived from Eqs. 8), (9), (10), and (11). The η in the equations (8) to (11) is an exhaust gas correction coefficient η derived in the previous charge.

<Estimating unit 204>
The estimation unit 204 uses the correction value of the flow rate of each component contained in the exhaust gas derived by the parameter derivation unit 202 to measure the temperature and carbon concentration of the molten steel 102 at each time from the current time in the current charge to the blow-off. Derivation of the estimated value of. Then, the estimation unit 204 uses an operation amount (main lance 105 or O ₂ gas flow rate that needs to be blown) for the temperature and carbon concentration of the molten steel 102 at the time of blowing off to reach the target value (or within the target range). Etc.) are derived. Since these derivations can be realized by, for example, the known techniques described in Patent Documents 2 and 3, detailed description thereof will be omitted here. In addition, instead of or in addition to the carbon concentration, the concentration of impurities such as phosphorus other than carbon may be derived.

<Output unit 205>
The output unit 205 outputs a control signal based on the manipulated variable derived by the estimation unit 204 to the control device of the converter equipment 100. As a result, the converter equipment 100 is operated according to the operation amount indicated by the control signal.

<Flow chart>
Next, an example of the processing of the converter control device 200 will be described with reference to the flowchart of FIG. The flowchart of FIG. 2 shows the processing in one charge. The flowchart of FIG. 2 is executed each time charging is executed.
In step S201, the data acquisition unit 201 acquires measurement data. The measurement data is acquired at a predetermined sampling cycle.
Next, in step S202, the data acquisition unit 201 determines whether or not the current charge (charge to be measured) has been completed. This determination can be made, for example, based on a predetermined blowing time.

As a result of this determination, if the current charge is not completed, the process proceeds to step S205 described later. On the other hand, when the current charge is completed, the measurement data in the current charge is obtained. Then, in step S203, the parameter derivation unit 202 derives the exhaust gas correction coefficient η and the integrated value Σ x _CO2 (t) of the ingress CO ₂ flow rate x _CO2 (t) by the equations (1) and (2).

Next, in step S204, the parameter derivation unit 202 rewrites the exhaust gas correction coefficient η stored in this step S204 in the previous charge to the exhaust gas correction coefficient η derived in the latest step S203, and updates the exhaust gas correction coefficient η. do. Then, the process according to the flowchart of FIG. 2 is completed.

If it is determined in step S202 that the current charge has not been completed, the parameter derivation unit 202 reads out the exhaust gas correction coefficient η stored in the parameter storage unit 203 in step S205. This exhaust gas correction coefficient η is an exhaust gas correction coefficient η stored in the parameter storage unit 203 in step S204 in the previous charge.
Next, in step S206, the parameter derivation unit 202 uses the carbon dioxide correction coefficient η read in step S205 and the measurement data acquired in step S201 in the current charge (charge to be measured) in the equation (7). Therefore, the ingress CO ₂ flow rate x _CO2 (t) at the current time t in the current charge is derived.

Next, in step S207, the parameter derivation unit 202 uses the exhaust gas correction coefficient η derived in the previous charge and the measurement data at the current time t (measurement data acquired in the latest step S201) to prepare the exhaust gas. The correction value of the flow rate of each contained component at the current time t is derived as the correction value of the exhaust gas information (see equations (8) to (11)).
Next, in step S208, the estimation unit 204 uses the correction value at the current time t of the flow rate of each component contained in the exhaust gas derived in step S207 from the current time t in the current charge to the blow-off. The temperature and carbon concentration of the molten steel 102 at each time are derived. Then, the estimation unit 204 derives an operation amount (main lance 105 or the flow rate of O ₂ gas that needs to be blown, etc.) for making the temperature and carbon concentration of the molten steel 102 at the time of blowing off reach the target values.

Next, in step S209, the output unit 205 outputs a control signal based on the manipulated variable derived in step S208 to the control device of the converter equipment 100. At this stage, the current charge has not been completed, so the process returns to step S201.

<Summary>
As described above, in the present embodiment, the converter control device 200 has the first equation (1) in which the exhaust gas correction coefficient η and the flow rate of CO ₂ gas entering the exhaust gas duct 108 from the atmosphere x _CO2 (t) are unknown. The unknown is derived based on the equation (1) and the second equation (equation (7)). The first equation is the integrated value of the sum of the CO ₂ gas flow rate f _CO2 (t) and the CO gas flow rate f _CO (t) from the time t1 of the intermediate measurement to the time t2 of the blowout measurement, and the exhaust gas. From the value obtained by multiplying the correction coefficient η, the sum of the flow rate of CO ₂ gas entering the exhaust gas duct 108 from the atmosphere x _CO2 (t) and the flow rate of CO ₂ gas contained in the blown gas y _CO2 (t). The value obtained by subtracting the integrated value from the time t1 of the intermediate measurement to the time t2 of the blow-off measurement and multiplying the value by the conversion coefficient for converting the flow rate of each gas into the mass of carbon is from the time t1 of the intermediate measurement. It is an equation showing that it is equal to the decarburized amount C up to the time t2 of the blow-off measurement. The second equation converts the value obtained by subtracting the sum of the flow rates of exhaust gas other than N ₂ gas from the flow rate f (t) of the exhaust gas, the exhaust gas correction coefficient η, and the flow rate of N ₂ gas into the flow rate of CO ₂ gas. It is an equation showing that the value obtained by multiplying the conversion coefficient for the purpose is equal to the flow rate of CO ₂ gas entering the exhaust gas duct 108 from the atmosphere x _{CO 2} (t).

Here, the flow rate of CO ₂ entering the exhaust gas duct 108 from the atmosphere x _CO2 (t) and the flow rate of CO ₂ gas contained in the blown gas y _CO2 (t) include carbon decarburized from the molten steel 102. is not. Therefore, by configuring as in the first equation, the exhaust gas correction coefficient η can be accurately corresponded to the actual value of the decarburized amount.
Further, since the N ₂ gas is an inert gas, the flow rate f _N2 (t) of the N ₂ gas and the exhaust gas correction coefficient η obtained from the flow rate f (t) of the exhaust gas measured by the exhaust gas flow meter 112 The product can be expressed as equal to the flow rate of N ₂ gas entering the exhaust gas duct 108 from the atmosphere x _CO2 (t). By constructing the second equation based on this, the flow rate of CO ₂ gas entering the exhaust gas duct 108 from the atmosphere x _{CO 2} (t) can be accurately expressed. Therefore, by using the first equation and the second equation, the exhaust gas correction coefficient η for correcting the measurement error of the exhaust gas flow meter 112 can be accurately derived.

Then, the correction value of the flow rate of each component contained in the exhaust gas is obtained by using the exhaust gas correction coefficient η derived as described above, and based on this correction value, the molten steel 102 at each time from the current time to the blow-off Derive estimates of temperature and carbon concentration. This makes it possible to accurately derive the temperature and carbon concentration of the molten steel 102. Since the temperature and carbon concentration of the molten steel 102 can be derived accurately, control for accurately controlling the temperature and carbon concentration of the molten steel 102 at the time of blowing off to reach the target value (or within the target range) should be performed accurately. Can be done.

Further, in the present embodiment, the third equation (formula (2)) is constructed from the second equation. The third equation is the flow rate of gas other than N ₂ gas obtained from the flow rate f (t) of the exhaust gas measured by the exhaust gas flow meter 112 and the flow rate f (t) of the exhaust gas measured by the exhaust gas flow meter 112. The integrated value from the time t1 of the intermediate measurement to the time t2 of the blow-off measurement, the exhaust gas correction coefficient η, and the coefficient for converting the flow rate of N ₂ gas to the flow rate of CO ₂ gas. The value obtained by multiplying by is equal to the integrated value Σ x _CO2 (t) of the flow rate x _CO2 (t) of CO ₂ entering the exhaust gas duct 108 from the atmosphere from the time t1 of the intermediate measurement to the time t2 of the blowout measurement. It is an expression showing that. After the measurement at the time of blowing off is completed, the converter control device 200 has the exhaust gas correction coefficient η and the flow rate of CO ₂ entering the exhaust gas duct 108 from the atmosphere x _CO2 (t) from the first equation and the third equation. ), The integrated value Σx _CO2 (t) from the time t1 of the intermediate measurement to the time t2 of the blow-off measurement is derived, and the exhaust gas correction coefficient η is stored. Then, the converter control device 200 gives the exhaust gas correction coefficient η derived in the previous charge to the second equation, so that the flow rate of CO ₂ entering the exhaust gas duct 108 from the air at the current time t x _CO2 (t). Is derived. Since the measurement error of the exhaust gas flow meter 112 does not change suddenly, the exhaust gas correction coefficient η does not have to be obtained in real time. Therefore, by using the exhaust gas correction coefficient η derived in the previous charge, the flow rate x _CO2 (t) of CO ₂ entering the exhaust gas duct 108 from the atmosphere can be obtained in real time.

<Modification example>
In the present embodiment, the case where the integrated value from the time t1 of the intermediate measurement to the time t2 of the blow-off measurement is used has been described as an example. Two different times between the end of the pre-process (for example, preliminary refining) of the blowing (for example, primary refining) and the time before the start of the next process (for example, secondary refining) of blowing, the converter 101. If the integrated value between the two times for measuring the carbon concentration of the molten steel 102 in the ladle is used, it is not always necessary to use the integrated value from the time t1 of the intermediate measurement to the time t2 of the blowout measurement. There is no. For example, it is possible to use the integrated value of the period between any two of the time of the measurement at the start of blowing, the time of the intermediate measurement, the time of the measurement at the stop of blowing, and the time of the measurement at the top of the pot. Here, the on-pot measurement refers to measuring the temperature and carbon concentration of the molten steel 102 in the ladle after the steel is discharged from the converter 101 and before the start of the next step.

Further, in the present embodiment, the case where the exhaust gas correction coefficient η derived in the previous charge is used as the exhaust gas correction coefficient η in the calculation of the equation (7) has been described as an example. However, if the exhaust gas correction coefficient η is obtained by using the exhaust gas correction coefficient η derived in the past charge, it is not always necessary to do so. For example, the representative value of the exhaust gas correction coefficient η derived in the past n (n is an integer of 2 or more) charge may be used.

Further, as in the present embodiment, if the exhaust gas correction coefficient η derived in the previous charge is used as the exhaust gas correction coefficient η in the calculation of the equation (7), the flow rate of CO ₂ entering the exhaust gas duct 108 from the air x It is preferable because _CO2 (t) can be obtained in real time. However, after the time of the measurement at the start of blowing in the current charge ends, the exhaust gas correction coefficient η derived from the equations (1) and (2) in the current charge is given to the equation (7) from the atmosphere. The flow rate x _{CO 2} (t) of CO ₂ entering the exhaust gas duct 108 at each time t of the current charge may be derived (ex post facto).

The embodiment of the present invention described above can be realized by executing a program by a computer. Further, a computer-readable recording medium on which the program is recorded and a computer program product such as the program can also be applied as an embodiment of the present invention. As the recording medium, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a magnetic tape, a non-volatile memory card, a ROM, or the like can be used.
In addition, the embodiments of the present invention described above are merely examples of embodiment of the present invention, and the technical scope of the present invention should not be construed in a limited manner by these. It is a thing. That is, the present invention can be implemented in various forms without departing from the technical idea or its main features.

101: converter, 102: molten steel, 103: slag, 104: sublance, 105: main lance, 106: skirt, 107: hood, 108: exhaust gas duct, 109: blown gas component analyzer, 110: blown gas flow rate. Meter, 111: Exhaust gas component analyzer, 112: Exhaust gas flow meter, 200: Converter control device, 201: Data acquisition unit, 202: Parameter derivation unit, 203: Parameter storage unit, 204: Estimator unit, 205: Output unit

Claims (12)

Achievement acquisition means for acquiring achievement data at the time of blowing in a converter,
Based on the actual data, it has an exhaust gas correction coefficient and a parameter derivation means for deriving the ingress CO ₂ flow rate.
The actual data includes the actual value of the flow rate of the exhaust gas generated from the converter during smelting at each time, and the actual value of the flow rate of CO gas, CO ₂ gas, and O ₂ gas contained in the exhaust gas at each time. Includes the actual value of the flow rate of CO ₂ gas contained in the blown gas blown into the molten steel in the converter during smelting at each time and the actual value of the decarburized amount of the molten steel.
The exhaust gas correction coefficient is a coefficient multiplied by the flow rate of the exhaust gas measured by the measuring means in order to correct the measurement error of the measuring means for measuring the flow rate of the exhaust gas.
The invading CO ₂ flow rate is the flow rate of CO ₂ entering the exhaust gas duct through which the exhaust gas passes from the atmosphere .
A converter parameter derivation device characterized in that the blown gas is only CO ₂ gas, or the main gas contained in the blown gas is CO ₂ gas . The parameter derivation means derives the exhaust gas correction coefficient and the ingress CO ₂ flow rate based on the first equation and the second equation.
The first equation is at least a value obtained by multiplying the integrated value from the first time to the second time of the sum of the CO ₂ gas contained in the exhaust gas and the flow rate of the CO gas by the exhaust gas correction coefficient. And, the integrated value of the invading CO ₂ flow rate from the first time to the second time, and the flow rate of the CO ₂ gas contained in the blown gas, from the first time to the second time. It is an equation showing the relationship between the integrated value up to the time and the decarburized amount of the molten steel from the first time to the second time.
The second equation is an equation showing at least the relationship between the flow rate of the exhaust gas, the total value of the flow rate of a predetermined gas other than the N ₂ gas contained in the exhaust gas, and the ingress CO ₂ flow rate.
The predetermined gas is CO ₂ gas, CO gas, and O ₂ gas .
The first time and the second time are two different times from the end of the pre-blow process to the start of the next flow process, and are at least the carbon of the molten steel. The converter parameter derivation device according to claim 1, wherein the concentration is measured at two times. The first equation is based on a value obtained by multiplying the integrated value of the sum of the CO ₂ gas and the flow rate of the CO gas contained in the exhaust gas from the first time to the second time and the exhaust gas correction coefficient. The value obtained by subtracting the integrated value from the first time to the second time of the sum of the incoming CO ₂ flow rate and the flow rate of the CO ₂ gas contained in the blown gas, and the flow rate of each gas are carbon. It is an equation showing that the value obtained by multiplying the conversion coefficient for converting to the mass of is equal to the decarburization amount of the molten steel from the first time to the second time.
In the second equation, the value obtained by subtracting the total value of the flow rate of a predetermined gas other than the N ₂ gas contained in the exhaust gas from the flow rate of the exhaust gas, the exhaust gas correction coefficient, and the flow rate of the N ₂ gas are CO. 2. The converter parameter derivation device according to claim 2, wherein the value obtained by multiplying the conversion coefficient for converting to the flow rate of _two gases is equal to the ingress CO ₂ flow rate. After the second time has elapsed, the parameter deriving means uses the actual data, the first equation, and the third equation to describe the exhaust gas correction coefficient and the ingress CO ₂ flow rate. The integrated value from the first time to the second time is derived, and then the actual data, the first equation, the exhaust gas correction coefficient derived from the third equation, and the actual result are derived. From the data and the second equation, the ingress CO ₂ flow rate at each time is derived.
The third equation includes at least a value obtained by multiplying the integrated value of the flow rate of the exhaust gas from the first time to the second time and the exhaust gas correction coefficient, and N ₂ contained in the exhaust gas. The value obtained by multiplying the integrated value from the first time to the second time of the total flow rate of a predetermined gas other than the gas by the exhaust gas correction coefficient, and the second of the ingress CO ₂ flow rates. The converter parameter derivation device according to claim 2, wherein the equation shows the relationship with the integrated value from the time of 1 to the second time. The third equation is a value obtained by subtracting the total value of the flow rate of a predetermined gas other than the N ₂ gas contained in the exhaust gas from the flow rate of the exhaust gas, from the first time to the second time. The value obtained by multiplying the integrated value, the exhaust gas correction coefficient, and the conversion coefficient for converting the flow rate of N ₂ gas into the flow rate of CO ₂ gas is the first time of the ingress CO ₂ flow rate from the first time. The converter parameter derivation device according to claim 4, wherein the formula is equal to the integrated value up to the time of 2. After the second time has elapsed, the parameter deriving means uses the actual data, the first equation, and the third equation to determine the exhaust gas correction coefficient and the ingress CO ₂ flow rate. , The integrated value from the first time to the second time is derived, and the exhaust gas correction coefficient is stored in the parameter storage means.
₄ . 5. The converter parameter derivation device according to 5. The sixth aspect of claim 6 is characterized in that the parameter deriving means derives the ingress CO ₂ flow rate at the current time by using the previous value of the exhaust gas correction coefficient, the actual data, and the second equation. The converter parameter derivation device described. The first time and the second time are any one of the time of the measurement at the start of blowing, the time of the intermediate measurement, the time of the measurement at the time of stopping, and the time of the measurement at the time of the pot.
The time of the measurement at the start of blowing is the time from the end of the pre-blow process to the start of the blow, and is the time at least for measuring the carbon concentration of the molten steel in the converter. ,
The time of the intermediate measurement is a time in the middle of blowing, which is a time for at least measuring the carbon concentration of the molten steel in the converter.
The time of the blow-off measurement is the time from the end of the blow to the start of the next step of the blow, which is the time to at least measure the carbon concentration of the molten steel in the converter.
The time of the on-pot measurement is the time from the time when the steel is ejected to the time before the start of the next step of smelting, and is the time when at least the carbon concentration of the molten steel in the ladle is measured. The converter parameter derivation device according to any one of claims 2 to 7. The converter parameter according to any one of claims 1 to 8, wherein the parameter deriving means derives a correction value of the actual value by multiplying the actual value by the exhaust gas correction coefficient. Derivation device. The ninth aspect of the present invention is characterized in that it further has an estimation means for deriving at least an estimated value of the temperature and the impurity concentration of the molten steel at each time from the current time to the blow-off based on the corrected value of the actual value. Converter parameter derivation device. Achievement acquisition process to acquire the actual data at the time of blowing in the converter,
Based on the actual data, it has an exhaust gas correction coefficient and a parameter derivation process for deriving the ingress CO ₂ flow rate.
The actual data includes the actual value of the flow rate of the exhaust gas generated from the converter during smelting at each time, and the actual value of the flow rate of CO gas, CO ₂ gas, and O ₂ gas contained in the exhaust gas at each time. Includes the actual value of the flow rate of CO ₂ gas contained in the blown gas blown into the molten steel in the converter during smelting at each time and the actual value of the decarburized amount of the molten steel.
The exhaust gas correction coefficient is a coefficient multiplied by the flow rate of the exhaust gas measured by the measuring means in order to correct the measurement error of the measuring means for measuring the flow rate of the exhaust gas.
The invading CO ₂ flow rate is the flow rate of CO ₂ entering the exhaust gas duct through which the exhaust gas passes from the atmosphere .
A method for deriving a converter parameter, characterized in that the blown gas is only CO ₂ gas, or the main gas contained in the blown gas is CO ₂ gas . A program characterized in that a computer functions as each means of the converter parameter derivation device according to any one of claims 1 to 10.

Images