Operation device for blast furnace and operation method for blast furnace

Abstract

Provided is an operation device that makes it possible to determine the restoration of the flow rate of blowing air in a wind reduction state of a blast furnace.　An operation device 1 is used for operation of a blast furnace 100, the operation device comprising a control unit 30. The control unit 30 executes a determination process using a determination index that includes at least an evaluation index for ventilation abnormality when a wind reduction state is attained upon detection of the ventilation abnormality in the blast furnace 100, and decides to perform a wind increase operation when the control unit 30 determines in the determination process that a predetermined condition is satisfied.

Description

Blast furnace operating equipment and blast furnace operating method

[0001] The present disclosure relates to an operating device and an operating method used in the operation of a blast furnace. For example, the present disclosure relates to a technology related to an operating method of a blast furnace process, and more specifically, to determining an abnormality in ventilation in a blast furnace and determining whether to restore the blast flow rate in a state in which the blast flow rate in the blast furnace has been reduced in response to the abnormality in ventilation, i.e., in a reduced ventilation state.

[0002] Conventionally, there are known techniques for detecting or predicting ventilation abnormalities in a blast furnace to prevent the abnormality from becoming larger, and for mitigating ventilation abnormalities such as blow-by by performing a wind reduction operation to reduce the blast flow rate in advance. For example, Patent Document 1 discloses an abnormality determination device for a blast furnace that can distinguish between an abnormal operation state and an abnormal sensor state. For example, Patent Document 2 discloses an operation status evaluation system that, when operating a blast furnace, not only predicts the risk of blow-by occurring but also predicts the scale of blow-by when it occurs and displays the prediction results to an operator, thereby enabling more reliable prevention of blow-by and problems such as furnace heat loss associated with blow-by.

[0003] Patent No. 6825753 Patent No. 6690081

[0004] When reducing the airflow, for example, as described in Patent Documents 1 and 2, an index indicating the degree of ventilation abnormality that is unified based on statistical methods and a rule-based "well-flow score" are used to determine the ventilation abnormality and reduce the airflow accordingly. On the other hand, with regard to restoring the airflow rate after reducing the airflow, the prior art does not take into consideration a clear method, such as the timing of restoration, and currently the reduced airflow rate is restored based on the operator's perception.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide an operating device and an operating method that enable determination of the restoration of the blast flow rate when the blast furnace is in a reduced-air-flow state.

[0006] (1) An operating device according to one embodiment of the present disclosure is an operating device used for operating a blast furnace, and includes a control unit. When a reduced airflow state occurs due to the detection of an abnormality in the airflow in the blast furnace, the control unit executes a determination process using a determination index that includes at least an evaluation index for the abnormality in the airflow, and when it determines that a predetermined condition is satisfied in the determination process, it decides to increase the airflow.

[0007] (2) As one embodiment of the present disclosure, in (1), the evaluation index includes a Q statistic based on principal component analysis using output values ​​of a group of shaft pressure sensors installed around the furnace body of the blast furnace as input.

[0008] (3) As one embodiment of the present disclosure, in (2), the predetermined condition includes a first condition that the Q statistic is equal to or less than a first threshold.

[0009] (4) As an embodiment of the present disclosure, in (3), the control unit executes a wind reduction operation when it determines that the first condition is not satisfied and the Q statistic is on an increasing trend.

[0010] (5) As one embodiment of the present disclosure, in any of (1) to (4), the judgment index further includes the time elapsed since the wind reduction state was established, and the predetermined condition includes a second condition that the time is equal to or greater than a second threshold value.

[0011] (6) As an embodiment of the present disclosure, in any one of (1) to (5), the judgment index further includes a furnace top temperature of the blast furnace, and the predetermined conditions include a third condition that the furnace top temperature is equal to or lower than a third threshold value.

[0012] (7) As an embodiment of the present disclosure, in any one of (1) to (6), the judgment index further includes a gas utilization rate in the blast furnace, and the predetermined condition includes a fourth condition that the gas utilization rate is equal to or greater than a fourth threshold and equal to or less than a fifth threshold.

[0013] (8) As an embodiment of the present disclosure, in any one of (1) to (7), when the control unit determines that the predetermined condition is satisfied in the determination process, the control unit restores the air flow rate to a normal state by the air increase operation.

[0014] (9) As an embodiment of the present disclosure, in any of (1) to (8), the device further includes: a sensor unit used to acquire the judgment index; and a memory unit that stores data acquired by the sensor unit, wherein the control unit calculates the judgment index by referring to the data stored in the memory unit, and determines whether or not a specified condition is satisfied in the judgment process using the calculated judgment index.

[0015] (10) An operating method according to one embodiment of the present disclosure is an operating method used in operating a blast furnace, and includes: when a reduced airflow state occurs due to detection of an abnormal airflow in the blast furnace, executing a determination process using a determination index that includes at least an evaluation index for the abnormal airflow; and when it is determined in the determination process that a predetermined condition is satisfied, deciding to increase the airflow.

[0016] (11) As one embodiment of the present disclosure, in (10), the evaluation index includes a Q statistic based on principal component analysis using output values ​​of a group of shaft pressure sensors installed around the furnace body of the blast furnace as input.

[0017] (12) As one embodiment of the present disclosure, in (11), the method further includes performing a wind reduction operation when it is determined in the determination process that the predetermined condition is not satisfied and that the Q statistic is on an increasing trend.

[0018] (13) As an embodiment of the present disclosure, in any one of (10) to (12), the judgment indicator includes the time elapsed since the reduced wind state was established, the furnace top temperature of the blast furnace, or the gas utilization rate in the blast furnace.

[0019] (14) As an embodiment of the present disclosure, in any one of (10) to (13), when it is determined in the determination process that the predetermined condition is satisfied, the air flow rate is returned to a normal state by the air increase operation.

[0020] According to an operation device and an operation method according to an embodiment of the present disclosure, it is possible to determine whether the blast flow rate will be restored when the blast furnace is in a reduced airflow state.

[0021] Fig. 2 is a schematic diagram showing a sensor unit of an operation device according to an embodiment of the present disclosure, which is arranged with respect to a blast furnace. Fig. 3 is a block diagram showing an example of a configuration of an operation device according to an embodiment of the present disclosure. Fig. 4 is a flowchart showing an example of an operation of the operation device of Fig. 2. Fig. 5 is a first graph diagram for explaining an example of an operation of the operation device of Fig. 2. Fig. 6 is a second graph diagram for explaining an example of an operation of the operation device of Fig. 2.

[0022] The background and problems of the prior art will be explained in more detail.

[0023] As described above, methods for predicting or detecting ventilation abnormalities have been proposed. In such conventional techniques, the timing of the abnormality is indicated and the airflow is reduced. However, in the recovery trend from an abnormal operating state indicating a ventilation abnormality such as a ventilation abnormality to a normal operating state indicating normal ventilation, sufficient consideration has not been given to determining the appropriate timing for returning the reduced airflow to the original airflow rate.

[0024] In a blast furnace, the blast flow rate is directly linked to production volume, and slow return to reduced blast flow leads to reduced molten iron production. On the other hand, if the blast flow rate is returned too early despite poor furnace conditions, such as ventilation, it may further worsen furnace conditions. As a result, further reduction in blast flow is required, and this must be done for a long period of time. Unreasonable return to reduced blast flow rate leads to a significant deterioration in furnace conditions and increases the risk of equipment trouble due to large blowouts.

[0025] The problems that the invention aims to solve will be explained in more detail below.

[0026] Shaft pressure gauges are arranged in the height direction and circumferential direction around the blast furnace body. Pressure is applied to the outer peripheral surface layer of the raw materials inside the furnace, and a phenomenon occurs in which the pressure is released. At this time, there is a high possibility that a localized ventilation abnormality due to a so-called "small blow-by" has occurred inside the blast furnace. In this disclosure, the above-mentioned condition is defined as a "small blow-by." In blast furnace operation, in order to protect the blast furnace body, if the pressure inside the furnace suddenly increases, a pressure valve located at the top of the furnace is opened. In blast furnace operation, this is usually referred to as a "blow-by," but in order to distinguish it from the "blow-by," this disclosure describes a "small blow-by" as an example of a ventilation abnormality.

[0027] Even a small leak can cause localized collapse of raw materials stacked in layers inside the blast furnace. If the localized collapse of raw materials is large, and the blast flow rate is returned without resolving the localized collapse, a negative operating cycle will occur in which further small leaks occur, causing further collapse of the raw materials. This could force a long-term production cut.

[0028] In order to address the above-mentioned problems, it is not necessarily appropriate to return the airflow reduction state simply because an index indicating the degree of abnormality in ventilation and a rule-based "ventilation score" intended to predict or detect ventilating have fallen below a threshold for the risk of ventilating. Unless a different determination process is performed to return the airflow rate, it is not easy to appropriately determine and operate the return of the airflow rate.

[0029] In order to solve the above problems, the present disclosure aims to provide an operating device and an operating method that enable determination of the return of the blast flow rate when the blast flow rate is reduced in a blast furnace. For example, the present disclosure proposes a new method for determining the timing of returning the blast flow rate after the reduction in the blast flow rate.

[0030] An example of the configuration and operation of an operation device 1 according to an embodiment of the present disclosure will be mainly described below with reference to the accompanying drawings. Fig. 1 is a schematic diagram showing a sensor unit 10 of the operation device 1 according to an embodiment of the present disclosure, which is arranged with respect to a blast furnace 100. Fig. 2 is a block diagram showing an example of the configuration of the operation device 1 according to an embodiment of the present disclosure. As shown in Fig. 2, the operation device 1 has the sensor unit 10, a memory unit 20, a control unit 30, and an output unit 40.

[0031] As shown in Figure 1, a blast tuyere 110 for adjusting the blast flow rate inside the blast furnace 100 is disposed at the bottom of the blast furnace 100 as an operating element related to the operating device 1. In the normal state of operation of the blast furnace 100, high-temperature air is blown from the blast tuyere 110 and injected into the furnace. If an abnormality in ventilation is determined, the blast flow rate is reduced by the blast tuyere 110, and the reduced air flow state is maintained until the ventilation state is restored. If the control unit 30 determines through a determination process described below that it is acceptable to return the blast flow rate, the blast tuyere 110 increases the blast flow rate.

[0032] The sensor unit 10 has a plurality of shaft pressure sensors 11 arranged in both the height direction and the circumferential direction around the furnace body of the blast furnace 100. The shaft pressure sensors 11 measure the pressure of the surface layer inside the blast furnace 100. The sensor unit 10 has at least one furnace top gas thermometer 12 arranged in the upper part of the blast furnace 100. The sensor unit 10 has an exhaust gas meter 13 that measures exhaust gas components of gas that passes through the interior of the blast furnace 100 and is discharged from the furnace top. The exhaust gas meter 13 measures, for example, N ２ , H ２ , CO, CO ２ The exhaust gas meter 13 is disposed after the gas cleaning device 120 disposed at the top of the blast furnace 100.

[0033] The sensor unit 10 is used to acquire a judgment index. The judgment index is used in the judgment process executed by the control unit 30, which will be described later. In the present disclosure, the "judgment index" includes, for example, at least an evaluation index for abnormal ventilation. The "evaluation index" includes a Q statistic based on principal component analysis using as input the output values ​​of a group of shaft pressure sensors 11 installed around the furnace body of the blast furnace 100. In addition, the judgment index may further include the time that has elapsed since the blast furnace 100 entered a reduced wind state. The judgment index may further include the furnace top temperature of the blast furnace 100 acquired using at least one furnace top gas thermometer 12. The judgment index may further include the gas utilization rate in the blast furnace 100 acquired using an exhaust gas meter 13. In the present disclosure, the "gas utilization rate" may include, for example, the exhaust gas CO ２ / (exhaust gas CO ２ + exhaust gas CO).

[0034] As shown in FIG. 2 , the storage unit 20 includes storage modules such as a hard disk drive (HDD), a solid state drive (SSD), an electrically erasable programmable read-only memory (EEPROM), a read-only memory (ROM), and a random access memory (RAM). The storage unit 20 may function as a main storage module, an auxiliary storage module, or a cache memory. The storage unit 20 is not limited to being built into the operation device 1, and may include storage media such as removable media. The removable media include a universal serial bus (USB) memory, a compact disc (CD), a digital versatile disc (DVD), and a Blu-ray (registered trademark) disc (BD).

[0035] The memory unit 20 stores information necessary to realize the operation of the operating device 1. The memory unit 20 stores information obtained by the operation of the operating device 1. For example, the memory unit 20 can store an operating system (OS), various programs, various data, and the like. The memory unit 20 stores data acquired by the sensor unit 10. For example, the memory unit 20 collects and stores, as measurement values, the sensor values ​​of the shaft pressure sensor 11, the top gas thermometer 12, and the flue gas meter 13 installed after the gas purification device 120, which are installed in the furnace body of the blast furnace 100. In addition, the memory unit 20 also collects and stores, as measurement values, the sensor values ​​of a blast flow meter attached to the blast furnace 100 that measures the blast flow rate inside the blast furnace 100.

[0036] The control unit 30 includes one or more processors, one or more programmable circuits, one or more dedicated circuits, or a combination thereof. In this disclosure, a "processor" refers to, but is not limited to, a general-purpose processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), or a dedicated processor specialized for a specific process. A "programmable circuit" refers to, but is not limited to, a FPGA (Field-Programmable Gate Array). A "dedicated circuit" refers to, but is not limited to, an ASIC (Application Specific Integrated Circuit). The control unit 30 calculates a judgment index by referring to data stored in the memory unit 20, and uses the calculated judgment index to determine whether a predetermined condition is satisfied in the judgment process described below. The control unit 30 includes a calculation unit 31 and a judgment unit 32.

[0037] The calculation unit 31 refers to the storage unit 20 that accumulates data from the group of sensors included in the sensor unit 10, and calculates each of the above-mentioned judgment indices. For example, the calculation unit 31 refers to data from a group of shaft pressure sensors 11 installed around the furnace body of the blast furnace 100, and calculates a Q statistic based on principal component analysis as an evaluation index for ventilation abnormality. For example, the calculation unit 31 may refer to data from at least one top gas thermometer 12 and calculate the furnace top temperature of the blast furnace 100 as an average value. For example, the calculation unit 31 may refer to data from an exhaust gas meter 13 and calculate the gas utilization rate in the blast furnace 100. In addition, the calculation unit 31 may also calculate the time that has elapsed since the blast furnace 100 entered a reduced wind state.

[0038] When the blast furnace 100 enters a reduced airflow state due to the detection of an abnormality in ventilation, the determination unit 32 executes a determination process described below using the determination index calculated by the calculation unit 31. When the determination unit 32 determines that a predetermined condition is satisfied in the determination process, it decides to perform an increased airflow operation. The determination unit 32 determines whether to restore the air flow rate according to the determination flow in the determination process.

[0039] In the present disclosure, the "predetermined condition" includes at least a first condition that the Q statistic, which is an evaluation index of an abnormal airflow, is equal to or less than a first threshold. In addition, the predetermined condition may further include a second condition that the time elapsed since the reduced airflow state was established is equal to or greater than a second threshold. The predetermined condition may further include a third condition that the furnace top temperature of the blast furnace 100 is equal to or less than a third threshold. The predetermined condition may further include a fourth condition that the gas utilization rate is equal to or greater than a fourth threshold and equal to or less than a fifth threshold.

[0040] The output unit 40 includes one or more output interfaces that output information to provide it to the user. The output interfaces include a display that visually outputs information as an image, a speaker that audibly outputs information as sound, and a vibrator that tactilely outputs information as vibration. For example, when the determination unit 32 determines that the airflow rate should be restored, the output unit 40 displays visual information on the display indicating that the airflow rate should be restored, and instructs the operator to restore the airflow rate.

[0041] In the operation of the blast furnace 100, the operation device 1 uses at least the above-described evaluation index for abnormal ventilation as a judgment index for returning the reduced amount of airflow after reducing the airflow in accordance with an index for detecting abnormal ventilation. In addition, the operation device 1 may further use at least one of the elapsed time after reducing the airflow, the furnace top temperature, and the gas utilization rate. In the present disclosure, in order for the control unit 30 to execute an appropriate judgment of returning the reduced airflow, a judgment index to be adopted for each factor that caused the abnormal ventilation that resulted in the reduction of the airflow has been newly determined based on phenomena and operation data. The grounds for the judgment indexes adopted in the present disclosure are described below.

[0042] The evaluation index for the ventilation abnormality will be described. The evaluation index is an index that represents an abnormal state of ventilation inside the blast furnace 100. Therefore, when the blast flow rate is returned after reducing the airflow, it is necessary that the evaluation index is at least equal to or less than the first threshold value for determining the abnormality that has been set. As an evaluation index that represents the ventilation abnormality, the above-mentioned Q statistic value that can unify the variation in the shaft pressure group and can detect the ventilation state inside the blast furnace 100 at an early stage can be considered.

[0043] Next, the time elapsed since the reduced airflow state will be described. As described above, when the measured values ​​of the shaft pressure sensors 11 at multiple heights in the same direction increase and then decrease, the pressure in the blast furnace 100 increases locally and then decreases. In the case of such a small blast, it is assumed that pressure is applied to the raw material and coke layers stacked inside the blast furnace 100, and the pressure decreases when the layers collapse. In such cases, the impact lasts longer than in other cases, continuing until the collapsed layers reach the vicinity of the lower part of the furnace, at least the cohesive zone. Therefore, even if indicators indicating abnormal ventilation and the "blast score" appear to have returned to normal at first glance, they may deteriorate again after a certain period of time has passed. Therefore, when restoring the reduced blast flow rate, it is necessary to consider monitoring the status of the blast furnace 100 for a certain period of time.

[0044] Next, the furnace top temperature will be described. Temperature increases may occur as measured by the furnace top gas thermometer 12 installed above the raw material charging surface in the upper part of the blast furnace 100. This is due to a change in the distribution of the charged raw materials caused by a small leak, i.e., a change in the gas flow distribution inside the furnace. This prevents the high-temperature gas blown in from the blast tuyere 110 from properly exchanging heat with the raw materials, preventing reactions such as reduction and heating of the raw materials from occurring to the fullest extent possible. When the heat exchange between the blast furnace gas and the raw materials is small, the gas is expected to rise to the upper part of the furnace while remaining relatively hot. In this case, the gas flow often passes through the center of the furnace circumferential direction. Therefore, such changes may not be readily apparent in the measured values ​​of the shaft pressure sensor 11 installed around the outer periphery of the blast furnace 100. As a result, it may not be easy to determine whether to resume the reduced airflow state based solely on indicators based on the shaft pressure value.

[0045] As described above, the furnace top temperature is an index that reflects to some extent the state of accumulation of raw materials inside the blast furnace 100, including the circumferential center. When restoring the reduced blast flow rate, it is important to observe the furnace top temperature, which indicates the passage history of the gas inside the furnace, for example, to manage it using an upper limit value of the furnace top temperature.

[0046] Next, the gas utilization rate will be described. In an abnormal state in which the gas flow near the center of the blast furnace 100 is high, the gas components generated from the blast furnace 100, such as the above-mentioned gas utilization rate, decrease. If a large amount of gas passes through the center of the furnace, where the ore charge is low, due to disturbances in the raw material distribution in the blast furnace 100 and deterioration of the gas flow in the lower part of the furnace, the opportunity for contact with the ore decreases, and the reduction of the ore decreases. As a result, the gas utilization rate is thought to decrease. A high gas utilization rate means that the iron ore is being reduced more efficiently. Therefore, while this is desirable from an operational standpoint, if the gas utilization rate is higher than that in a normal stable operating state, it is possible that the gas utilization rate is high due to reduced permeability. Therefore, it is desirable to set an appropriate upper limit. As described above, the gas utilization rate is the result of reactions such as reduction occurring as gas passes through the blast furnace 100, and therefore is an important judgment indicator when restoring the blast flow rate that has decreased due to reduced airflow.

[0047] Fig. 3 is a flowchart showing an example of the operation of the operating device 1 of Fig. 2. With reference to Fig. 3, an example of the flow of a determination process for determining the wind increasing operation, which is executed by the control unit 30 of the operating device 1, will be mainly described.

[0048] In step S101, the control unit 30 determines whether or not an air ventilation abnormality has been detected in the blast furnace 100. For example, the control unit 30 determines whether or not a small air leak has occurred in the blast furnace 100. For example, the control unit 30 may detect a small air leak based on conventional technology such as that shown in Patent Document 1. This is not a limitation, and the control unit 30 may predict a small air leak based on a similar technology. If the control unit 30 determines that an air ventilation abnormality has been detected, it executes the processing of step S102. If the control unit 30 determines that an air ventilation abnormality has not been detected, it repeats the processing from step S101. The control unit 30 maintains the current air blowing state in the blast furnace 100.

[0049] In step S102, if the control unit 30 determines that an air ventilation abnormality has been detected in step S101, it executes an air reduction operation in the blast furnace 100. For example, the control unit 30 may control the blast tuyere 110, which is an operating terminal in the blast furnace 100, so as to reduce the air flow rate inside the blast furnace 100. The control unit 30 is not limited to the above configuration in which the operation device 1 itself automatically controls the blast tuyere 110, and may be configured to output an air reduction instruction to the operator from the output unit 40 to prompt the operator to perform the air reduction operation.

[0050] In step S103, the determination unit 32 of the control unit 30 determines whether the time elapsed since the wind reduction operation in step S102 resulted in the wind reduction state is equal to or greater than a second threshold. The determination unit 32 determines whether the second condition is satisfied. If the determination unit 32 determines that the elapsed time is equal to or greater than the second threshold, it executes the process of step S104. If the determination unit 32 determines that the elapsed time is less than the second threshold, it repeats the process from step S103. In step S103 after the wind reduction operation, the control unit 30 temporarily suspends the determination process flow until a certain time has elapsed. This is because the blast furnace 100 is a system with a large reaction time constant, and it is not possible to determine the degree of impact of a small void on operation (ventilation) until a certain amount of time has elapsed.

[0051] In step S104, if the determination unit 32 of the control unit 30 determines in step S103 that the elapsed time is equal to or greater than the second threshold, the determination unit 32 determines whether the Q statistic calculated by the calculation unit 31 is equal to or less than the first threshold. The determination unit 32 determines whether the first condition is satisfied. If the determination unit 32 determines that the Q statistic is equal to or less than the first threshold, the determination unit 32 executes the process of step S106. If the determination unit 32 determines that the Q statistic is greater than the first threshold, the determination unit 32 executes the process of step S105.

[0052] In step S105, if the determination unit 32 of the control unit 30 determines that the Q statistic is greater than the first threshold in step S104, it determines whether the Q statistic is on an increasing trend. If the determination unit 32 determines that the Q statistic is on an increasing trend, it repeats the process from step S102 again. If the determination unit 32 of the control unit 30 determines that the first condition is not satisfied in step S104 and that the Q statistic is on an increasing trend in step S105, it executes the wind reduction operation again in step S102. If the determination unit 32 determines that the Q statistic is not on an increasing trend, it repeats the process from step S104 again. If the determination unit 32 of the control unit 30 determines that the first condition is not satisfied in step S104 and that the Q statistic is not on an increasing trend in step S105, it maintains the current wind reduction state.

[0053] In step S106, if the determination unit 32 of the control unit 30 determines that the Q statistic is equal to or less than the first threshold in step S104, it determines whether the furnace top temperature calculated by the calculation unit 31 is equal to or less than the third threshold. The determination unit 32 determines whether the third condition is satisfied. If the determination unit 32 determines that the furnace top temperature is equal to or less than the third threshold, it executes the processing of step S107. If the determination unit 32 determines that the furnace top temperature is greater than the third threshold, it repeats the processing from step S104 again. The determination unit 32 of the control unit 30 maintains the current wind reduction state.

[0054] In step S107, if the determination unit 32 of the control unit 30 determines that the furnace top temperature is equal to or lower than the third threshold in step S106, the determination unit 32 determines whether the gas utilization rate calculated by the calculation unit 31 is equal to or higher than the fourth threshold and equal to or lower than the fifth threshold. The determination unit 32 determines whether the fourth condition is satisfied. The determination unit 32 determines whether the gas utilization rate is within a predetermined range of equal to or higher than the fourth threshold and equal to or lower than the fifth threshold. If the determination unit 32 determines that the gas utilization rate is within the predetermined range, it executes the processing of step S108. If the determination unit 32 determines that the gas utilization rate is not within the predetermined range, the processing is repeated again from step S104. The determination unit 32 of the control unit 30 maintains the current air reduction state.

[0055] In step S108, the determination unit 32 of the control unit 30 determines that predetermined conditions, including all of the first, second, third, and fourth conditions, are satisfied in the above-described determination process, and determines to perform an air-increase operation. For example, the control unit 30 may output an air-increase instruction to the operator from the output unit 40 to prompt the operator to perform the air-increase operation. This is not a limitation, and for example, the control unit 30 may automatically control the blast tuyere 110, which is an operating element in the blast furnace 100, so as to increase the air flow rate inside the blast furnace 100. For example, when the control unit 30 determines that predetermined conditions are satisfied in the above-described determination process, the control unit 30 may restore the air flow rate to a normal state by performing an air-increase operation by the operation device 1 itself. When the air-increase operation is performed multiple times by the process of step S102 via step S105, it is more preferable to divide the air-increase operation into several steps and gradually reduce the air-increase amount. However, this is not a limitation, and all reduced air-increase amounts may be comprehensively reduced by a single air-increase operation.

[0056] Fig. 4 is a first graph diagram for explaining an example of the operation of the operating device 1 of Fig. 2. Fig. 4 conceptually shows the contents of the process in step S105 of Fig. 3. The contents of the process in step S105 of Fig. 3 will be described in more detail with reference to Fig. 4.

[0057] In the process of step S105, the determination unit 32 of the control unit 30 further compares the Q statistic with two additional thresholds. The thresholds include a seventh threshold Th7 that is greater than the first threshold in step S104 and a sixth threshold Th6 that is even greater than the seventh threshold Th7. The determination unit 32 determines that the Q statistic is on an increasing trend when the Q statistic value increases and exceeds the sixth threshold Th6. The determination unit 32 also determines that the Q statistic is on an increasing trend when the Q statistic value exceeds the seventh threshold Th7, which is lower than the sixth threshold Th6, for a certain period of time T or more.

[0058] The configuration and processing of the operating device 1 in Fig. 2 will be described in detail below using specific numerical values ​​as examples, but the present disclosure is not limited to the following examples in any way. The numerical values ​​described below are merely examples and do not limit the scope of the present disclosure. The scope of the present disclosure should be determined solely based on the description of the claims.

[0059] The elapsed time after the wind reduction, which is the judgment index in step S103 of FIG. 3, may be within the range of 15 to 60 minutes, for example. Immediately after the wind reduction, it is not easy to determine whether the abnormal ventilation phenomenon that caused the wind reduction will be resolved or will continue. Even if the shaft pressure group appears stable at first glance, there may be cases where the ventilation condition subsequently deteriorates due to a drop in a small open area. Therefore, it is preferable to wait at least 15 minutes before increasing the wind. Therefore, the lower limit of the elapsed time is set to 15 minutes.

[0060] On the other hand, if too much time is left, the production volume of molten pig iron will decrease by the amount of elapsed time. Therefore, if predetermined conditions are met in the judgment process from step S103 onwards using judgment indicators related to the ventilation state, etc., it is preferable to increase the air flow. Therefore, the upper limit of the elapsed time is set to 60 minutes. In the example of the present disclosure, the elapsed time is set to 30 minutes, with reference to data on past occurrences of small leaks in the target blast furnace 100.

[0061] The Q statistic, which is the determination index in step S104 of Fig. 3, is a single index of abnormalities based on the multiple shaft pressure sensors 11. In the example of the present disclosure, the Q statistic, which is an index of the multivariate statistical process control (MSPC) method, is used as the unification method. This method expresses abnormalities with fewer variables by aggregating multiple variables into principal components with orthogonal information amounts based on the correlation between the variables using principal component analysis (PCA).

[0062] In the operation device 1, the measured values ​​of the multiple shaft pressure sensors 11 used as input become a group of shaft pressure data as described above. The Q statistics and the principal component analysis on which it is based will be described according to the operation device 1 and the target process.

[0063] In principal component analysis, mathematical processing is performed on multiple synchronized (multi-dimensional) data groups to replace (reduce the dimension of) the data with a small number of variables that effectively reflect the characteristics of the original data while minimizing the loss of information contained in the original data groups as much as possible. In the case of data from the shaft pressure sensors 11, a total of 20 shaft pressure sensors 11 are installed on the furnace body of the blast furnace 100, five in the vertical direction and four in the circumferential direction. Principal component analysis is applied to the shaft pressure measurement values ​​at up to 20 points, and the data are assumed to be replaced with several variables (principal component values) that effectively reflect the characteristics of the 20-point data group. The operating device 1 can more easily estimate the state inside the blast furnace 100 by monitoring only the small number of variables generated by principal component analysis, without having to observe all 20 data groups.

[0064] Synchronization among multiple (multi-dimensional) data groups means that the behavior of operational variables is coordinated with respect to the time progression or operational actions in the process. In the shaft pressure data of the blast furnace 100 operation, the first principal component value, which has the largest variance in the principal component analysis, reflects the effects of setting changes related to the operational load, such as changes in the flow rate of the injected gas. Meanwhile, other unstable components appear in the second and subsequent components of the principal component analysis. The operating device 1 performs the determination process using these components.

[0065] For example, principal component analysis is applied to the data from the group of shaft pressure sensors 11 installed at the top of the blast furnace 100, and the second principal component with the largest variance value among the components in which the asynchrony appears is calculated. This value becomes the Q statistic. However, if the abnormal phenomenon appears significantly in the third component and subsequent components, the values ​​of the third component and subsequent components may also be used.

[0066] In order to calculate the indexed Q statistic used in the judgment process of the operation device 1, first, principal component analysis is applied to the time series data of the shaft pressure sensor 11 for the normal operation section inside the blast furnace 100. The second principal component z ２ In the normal operating section, the data must include the stability limit, i.e., the limit at which the system can be judged to be normal.

[0067] Next, the second principal component z ２ The maximum value of z ２,ｍａｘ is calculated. Calculating the maximum value of the second principal component for the normal time interval corresponds to calculating the fluctuation range of the sensor data during normal operation and the maximum amount of deviation from the normal operation range, that is, the value of the stability limit. When predicting an operational abnormality in the blast furnace 100, a judgment is made using an index obtained by dividing the second principal component calculated from the sensor data in the operation range where an abnormality is occurring by the maximum value of the second principal component calculated from the sensor data in the normal operation range. The first threshold value for making the judgment is set smaller than the threshold value used in the prediction or detection of a blow-through. The larger the value of the Q statistic used in the judgment process of the operation device 1, the higher the degree of abnormality.

[0068] The furnace top temperature, which is the judgment index in step S106 of Fig. 3, will be described. In many cases, a plurality of top gas thermometers 12 for measuring the furnace top temperature are installed above the raw material charging surface of the furnace body of the blast furnace 100. In the sensor unit 10 of the operation device 1, four top gas thermometers 12 are installed for the target blast furnace 100. The furnace top temperature used as the judgment index in the judgment process of the operation device 1 may be the average value of the measurement values ​​obtained by the four top gas thermometers 12. However, this is not limiting; in the judgment process of the operation device 1, it is sufficient to obtain an average value of the furnace top temperature, and therefore it is sufficient to install at least one furnace top gas thermometer 12.

[0069] In addition, the furnace top temperature value fluctuates up and down due to the influence of the timing of charging raw materials from the top of the blast furnace 100. The calculation unit 31 of the control unit 30 may further use a time-moving average of the above average to reduce the influence of charging. The time used for the time-moving average may be longer than one batch interval between raw material charging, for example, approximately 10 minutes, and may be approximately 15 to 30 minutes. In the operation of the blast furnace 100 targeted by the operation device 1, a 15-minute time-moving average was adopted. In the blast furnace 100 targeted by the operation device 1, the upper limit of the furnace top temperature was set to 150% of the temperature during normal operation based on past operation data. Since the temperature during normal operation is approximately 100°C, the upper limit of the furnace top temperature is approximately 150°C.

[0070] The gas utilization rate, which is the determination index in step S107 of Fig. 3, will be described. The gas utilization rate is CO / CO ２ However, in this disclosure, exhaust gas CO ２ / (exhaust gas CO ２ + exhaust gas CO). The upper and lower limits of the range that defines the predetermined range of the gas utilization rate are 47% at the lower limit and 49% at the upper limit in the blast furnace 100 that is the target of the operation device 1. The thresholds including the fourth threshold and the fifth threshold were determined by analyzing past operation data.

[0071] Fig. 5 is a second graph diagram for explaining an example of the operation of the operating device 1 of Fig. 2. Fig. 5 schematically shows the timing at which an air-increase instruction is output by the determination process of Fig. 3. With reference to Fig. 5, an example of the timing at which an air-increase instruction is output by the determination process of Fig. 3 will be mainly described.

[0072] In Figure 5, the data includes, from the top to bottom, shaft pressure group data of the reference blast furnace 100, Q statistics values, gas utilization rate (%), and furnace top temperature average (°C). In this data, two cases, Case C1 and Case C2, are shown as the timing when an abnormal ventilation is detected. The circles in the figure indicate the timing when the conditions for restoring the blast flow rate are met when an abnormal ventilation is detected and the airflow is reduced. The triangles in the figure indicate the timing when the conditions for restoring the blast flow rate are not met when an abnormal ventilation is detected and the airflow is reduced.

[0073] In case C1, after the Q statistic exceeds the threshold value Th0 for determining whether the gas is blown through, the Q statistic falls below the first threshold value Th1, which is included in the first condition, after a certain period of time (30 minutes) has elapsed. However, the gas utilization rate is not within the predetermined range between the fourth threshold value Th4 and the fifth threshold value Th5. For example, the gas utilization rate falls below the fourth threshold value Th4. Subsequently, when the gas utilization rate falls within the predetermined range, the Q statistic value exceeds the first threshold value Th1. Similarly, the average furnace top temperature also exceeds the third threshold value Th3. Subsequently, when the Q statistic falls below the first threshold value and the conditions for the other determination indicators are also satisfied, the airflow increase instruction I1 is executed.

[0074] In case C2, after the Q statistic exceeds the threshold value Th0 for determining whether a leak has occurred, the Q statistic exceeds the first threshold value Th1 included in the first condition after a certain period of time (30 minutes) has elapsed. After further time has elapsed, when the Q statistic becomes equal to or less than the first threshold value Th1, the average furnace top temperature still exceeds the third threshold value Th3. After that, when the average furnace top temperature becomes equal to or less than the third threshold value Th3 and the conditions for the other determination indicators are also satisfied, the airflow increase instruction I2 is executed.

[0075] The operation device 1 according to the embodiment described above makes it possible to determine whether to restore the blast flow rate when the blast furnace 100 is in a reduced-airflow state. This allows the operation device 1 to present to the operator the appropriate timing for increasing the airflow rate when the blast furnace 100 is in a reduced-airflow state due to an abnormal airflow. As a result, production losses caused by a delayed restoration of the blast flow rate are reduced. Conversely, further abnormal airflow caused by a premature restoration of the blast flow rate is reduced.

[0076] Although the present disclosure has been described based on the drawings and embodiments, it should be noted that those skilled in the art can make various modifications and alterations based on the present disclosure. Therefore, it should be noted that these modifications and alterations are included in the scope of the present disclosure. For example, the functions included in each configuration or step can be rearranged so as not to be logically inconsistent, and multiple configurations or steps can be combined or divided into one.

[0077] For example, the shape, size, pattern, arrangement, orientation, type, and number of each of the above-mentioned components are not limited to those shown in the above description and drawings. The shape, size, pattern, arrangement, orientation, type, and number of each component may be configured arbitrarily as long as the function can be realized. Each component of the illustrated operating device 1 is a functional concept. The specific form of each component is not limited to that shown in the drawings.

[0078] For example, a general-purpose electronic device such as a server, a smartphone, or a computer can be configured to function as the operation device 1 according to the above-described embodiment. Specifically, a program describing the processing content for realizing each function of the operation device 1 according to the embodiment is stored in the memory of the electronic device, and the program is read and executed by a processor of the electronic device. Therefore, the present disclosure can also be realized as a program executable by a processor.

[0079] Alternatively, the present disclosure may be realized as a non-transitory computer-readable medium storing a program that can be executed by one or more processors to cause the operating device 1 according to one embodiment to execute each function. It should be understood that these are also included within the scope of the present disclosure.

[0080] In the above embodiment, the determination unit 32 of the control unit 30 determines to perform the air-increase operation when it determines in the determination process that the predetermined conditions, including all of the first condition, the second condition, the third condition, and the fourth condition, are satisfied. However, this is not limited to this. The predetermined conditions may include at least the first condition. The predetermined conditions may further include at least one of the second condition, the third condition, and the fourth condition in addition to the first condition.

[0081] In the above embodiment, the evaluation index for the air permeability abnormality has been described as including the Q statistic based on the principal component analysis using the output values ​​of the group of shaft pressure sensors 11 installed around the furnace body of the blast furnace 100 as input, but is not limited thereto. The evaluation index for the air permeability abnormality may include any other index capable of evaluating the air permeability abnormality instead of or in addition to the Q statistic.

[0082] In the above embodiment, the control unit 30 executes the wind reduction operation when it determines that the first condition is not satisfied and that the Q statistics are on an increasing trend. However, this is not limited to this. The control unit 30 does not have to execute the process of determining whether the Q statistics are on an increasing trend.

[0083] In the above embodiment, when the control unit 30 determines that the predetermined condition is satisfied in the determination process, the control unit 30 returns the airflow rate to the normal state by increasing the airflow rate. However, the present invention is not limited to this. The control unit 30 does not have to completely return the airflow rate to the normal state by increasing the airflow rate, and may return the airflow rate to a rate different from the normal airflow rate.

[0084] REFERENCE SIGNS LIST 1 operating device 10 sensor unit 11 shaft pressure sensor 12 furnace top gas thermometer 13 exhaust gas meter 20 memory unit 30 control unit 31 calculation unit 32 judgment unit 40 output unit 100 blast furnace 110 blast tuyere 120 gas cleaning device C1 case C2 case I1 increase airflow instruction I2 increase airflow instruction Th0 judgment threshold Th1 first threshold Th2 second threshold Th3 third threshold Th4 fourth threshold Th5 fifth threshold Th6 sixth threshold Th7 seventh threshold T certain time

Claims

1. Operating equipment used in the operation of a blast furnace, It includes a control unit, and the control unit is When a reduced airflow state is detected due to an abnormality in the ventilation of the blast furnace, The Q statistic, which is an evaluation index for ventilation abnormalities based on principal component analysis using the output values ​​of the shaft pressure sensor group installed around the furnace body of the blast furnace as input, The time elapsed since the aforementioned reduced airflow condition occurred, The top temperature of the blast furnace and The gas utilization rate in the aforementioned blast furnace, A determination process for restoring the airflow rate in the reduced airflow state is performed using a determination index that includes at least the following: In the aforementioned recovery determination process, The second condition, that the aforementioned time is equal to or greater than the second threshold, is determined, and after determining that the second condition is met, The first condition is that the Q statistic is less than or equal to the first threshold, The third condition is that the furnace top temperature is below the third threshold, The fourth condition is that the gas utilization rate is between the fourth threshold and the fifth threshold, If it is determined that the condition is met, the decision is made to increase the airflow. Operating equipment.

2. The operating apparatus according to claim 1, If the control unit determines that the first condition is not met and the Q statistic is on an increasing trend, it will perform a fan reduction operation. Operating equipment.

3. An operating apparatus according to claim 1 or 2, If the control unit determines in the recovery determination process that the first condition, the second condition, the third condition, and the fourth condition have been met, it restores the airflow rate to the normal state by increasing the airflow rate. Operating equipment.

4. An operating apparatus according to claim 1 or 2, A sensor unit used to acquire the aforementioned judgment index, A storage unit that stores data acquired by the sensor unit, Furthermore, The control unit calculates the judgment index by referring to the data stored in the storage unit, and uses the calculated judgment index to determine whether the first condition, second condition, third condition, and fourth condition have been met in the recovery determination process. Operating equipment.

5. A method of operation used in the operation of a blast furnace, When a reduced airflow state is detected due to an abnormality in the ventilation of the blast furnace, The Q statistic, which is an evaluation index for ventilation abnormalities based on principal component analysis using the output values ​​of the shaft pressure sensor group installed around the furnace body of the blast furnace as input, The time elapsed since the aforementioned reduced airflow condition occurred, The top temperature of the blast furnace and The gas utilization rate in the aforementioned blast furnace, The process of determining the return of the airflow rate in the reduced airflow state is performed using a determination index that includes at least the following: In the aforementioned recovery determination process, if it is determined that predetermined conditions are met, the airflow increase operation is decided. Includes, The aforementioned predetermined conditions are: The second condition is that the aforementioned time is equal to or greater than the second threshold, The first condition is that the Q statistic is less than or equal to the first threshold, The third condition is that the furnace top temperature is below the third threshold, The fourth condition is that the gas utilization rate is between the fourth threshold and the fifth threshold, Includes, After it is determined that the second condition is met, the first, third, and fourth conditions are determined. Operating methods.

6. The operating method according to claim 5, The recovery determination process further includes, if it is determined that the first condition is not met and the Q statistic is on an increasing trend, then performing a reduction in airflow operation. Operating methods.

7. The operating method according to claim 5 or 6, If the recovery determination process determines that the first, second, third, and fourth conditions are met, it further includes restoring the airflow rate to the normal state by increasing the airflow rate. Operating methods.