Automatic air distribution control system and method for blast of blast furnace

Abstract

The invention discloses a blast furnace blast automatic air distribution control system and method, the system comprises a plurality of blast furnaces and a plurality of blast furnace blower sets, each blast furnace is provided with a corresponding blast furnace air supply mother pipe, each blast furnace blower set is provided with a plurality of air supply pipelines independently connected with each blast furnace air supply mother pipe, and the system also comprises an emergency air distribution mother pipe, the emergency air distribution main pipe is provided with a plurality of air distribution pipelines which are independently connected with the blast furnace air supply main pipes respectively, and each air distribution pipeline is provided with an air distribution valve set. Automatic mutual shifting of multiple blast furnaces and multiple air blower sets is successfully achieved, it can be guaranteed that under any working condition, the blast furnaces with the air blower sets having faults do not have accidents such as air breaking, material setting and slag filling due to the existence of the automatic air shifting system, and safe production of the blast furnaces is guaranteed.

Description

Technical Field

[0001] The invention relates to a blast furnace automatic control technology, and in particular to a blast furnace automatic air blowing control system and a method thereof. Background Art

[0002] At present, in the metallurgical industry, the blast furnace air blowing and ventilation systems of domestic steel mills vary according to the number of blast furnace blower units, the number of blast furnaces that need ventilation, and the air supply operation mode. The air volume and air pressure of the ventilation system are determined based on the experience accumulated during the operation process. When the ventilation system is put into operation, the air volume and air pressure that can be provided are closely related to the operation status of the blast furnace blower unit and the corresponding blast furnace. Whether to use manual ventilation or automatic ventilation varies according to the degree of mastery of the system and the different technical advancements of domestic steel mills. Specifically:

[0003] In terms of the control of the blast furnace blast and air diversion system configuration: Patent application number 201620686442.0, named a blast furnace air diversion system, is applicable to a system where two blast furnace blower units supply air to two blast furnaces. Patent application number 201420386624.7, named a device for multiple blower units of multiple blast furnaces to divert air to each other, is applicable to a system where four blast furnace blower units supply air to three blast furnaces. Patent application number 201621173701.6, named a redundant blast furnace automatic air diversion system, is applicable to a system where three blast furnace blower units supply air to three blast furnaces. The patent application number is 201721357882.2, and its name is an air distribution device for improving the reliability of air supply of blast furnace blower units. It is suitable for two blower units supplying air to two specific blast furnaces, one blower unit supplying air to four blast furnaces, and the other two blower units supplying air to another two specific blast furnaces. Four air supply ducts are connected to the air distribution main pipe, and one quick opening and closing valve and two manual valves are respectively provided on the four air supply ducts. When a blower unit fails, the system can distribute air to the blast furnace corresponding to the failed unit through the air supply duct.

[0004] The above four patents all belong to the technical field of blast furnace blower equipment, and are used for multiple blower units of multiple blast furnaces to exchange air with each other. Due to different levels of mastery of the system and technical advancement, operators are still manually operating the air exchange, and automatic air exchange control is not possible. In particular, patent 201721357882.2, the distance between the blast furnace blower unit and the blast furnace is different. Therefore, during normal operation, only one blast furnace blower unit can supply air to four blast furnaces, and the remaining four blast furnace blower units can only supply air to two specific blast furnaces. In other words, there are only 16 combinations of air supply methods during normal operation.

[0005] As the number of blast furnace blower units and corresponding blast furnaces increases, the operation mode of blast furnace blast air supply becomes more complicated, and the logical judgment of when emergency air diversion is needed and which blower unit to select for air diversion becomes more difficult. If the blast furnace blast air diversion system misjudges the manual air diversion, it may affect the air supply of multiple blast furnaces. In addition, there is uncertainty in the operating conditions of the blast furnace blower unit and the corresponding blast furnace. For example, when the operator needs to deal with the faulty blower unit in an emergency, or when the blast furnace is being replaced, the slow response speed of manual air diversion may affect the air supply of multiple blast furnaces. At present, there is no automatic air diversion control method suitable for multiple blast furnace blower units to multiple blast furnaces. Summary of the invention

[0006] In order to solve the above problems in the prior art, the present invention provides a blast furnace blast automatic air diversion control system and method, which can realize automatic mutual diversion of multiple blast furnaces and multiple blower units, and can ensure that a blast furnace with a faulty blower unit will not have accidents such as air interruption, material blocking, slag filling, etc. under any working conditions, so as to ensure safe production of the blast furnace.

[0007] On the one hand, a blast furnace blast automatic air diversion control system includes several blast furnaces and several blast furnace blower units, each blast furnace is equipped with a corresponding blast furnace air supply mother pipe, and each blast furnace blower unit has several air supply ducts respectively connected to the blast furnace air supply mother pipes. It is characterized in that it also includes an emergency air diversion mother pipe, the emergency air diversion mother pipe has several air diversion ducts respectively connected to the blast furnace air supply mother pipes, and each air diversion duct is provided with an air diversion valve group.

[0008] The air-displacing valve group comprises an electric regulating valve, a pneumatic butterfly valve and an electric gate valve which are arranged in sequence.

[0009] The emergency air discharging main pipe is also connected to a discharge pipeline.

[0010] On the other hand, a control method of a blast furnace automatic air diversion control system comprises the following steps:

[0011] A. If a blast furnace blower unit fails, determine whether the blower unit is automatically shut down due to a fault or manually shut down normally. If it is determined to be automatically shut down due to a fault, the automatic air-pumping start condition is met;

[0012] B. Automatically select the optimal blower unit for external air dissipation, including the following steps:

[0013] B1. Determine whether the selected blower unit is a normally operating unit and whether its corresponding air damper valve unit is normal;

[0014] B2. Among the blower units that meet the condition of B1, if any of the blower units to be selected is in the state of constant air volume, then select from the units in the state of constant air volume operation, and determine which blower unit to select for air displacing according to the specified air volume and the conditions of the interlocked blower units; if all the blower units to be selected are in the state of constant air pressure, then determine which blower unit to select for air displacing according to the specified air volume and the conditions of the interlocked blast furnace demand; if the specified air volumes of the blower units to be selected are the same, then select the blower unit with the smallest specified oxygen content for air displacing; if the specified air volumes and specified oxygen contents of the blower units to be selected are the same, then select the blower unit with the latest relatively running state and a non-faulty blower unit for air displacing;

[0015] C. Based on the selection result, the air displacing valve groups of the faulty blast furnace and the selected blower unit are started, so that the selected blower unit automatically displaces air to the blast furnace originally supplied with air by the faulty blower unit through the corresponding air displacing duct.

[0016] The step B2 further comprises:

[0017] If other blower units also have faults and need to be diverted, the faulty blower unit and the blower unit that has already diverted air to the outside will no longer be selected as the blower unit for diverting air to the outside.

[0018] The step B also includes:

[0019] B3. No matter which blower unit is selected to perform air diversion, corresponding display and alarm will be given, and "air supply alarm" and "air diversion" signals will be automatically sent to the faulty blast furnace and the blast furnace that diverts air to the outside respectively; when the blast furnace sends back a response signal, the "air supply alarm" and "air diversion" signals will be manually turned off.

[0020] The step B also includes: setting an "automatic air ventilation is not allowed" operation function to temporarily lock the command of the air supply blower unit corresponding to a blast furnace to automatically blow air to the outside. The blast furnace whose air ventilation is locked will be prohibited from operating to blow air to the outside, but can normally accept automatic air ventilation from other blast furnaces in the event of a fault.

[0021] The blast furnace blast automatic air diversion control system and method of the present invention have the following advantages:

[0022] First, the safety of blast furnaces is ensured: the present invention can realize the mutual support of multiple blast furnaces and multiple blower units, and can ensure that under any working conditions, a blast furnace with a faulty blower unit will not have accidents such as air interruption, material blocking, slag filling, etc. due to the existence of the automatic air distribution system, thereby ensuring the safe production of the blast furnace.

[0023] Second, reduce production capacity loss: the present invention can greatly improve the reliability of the air blowing action of the blast furnace blower unit, and can effectively avoid the economic losses caused by the blast furnace shutdown due to accidents such as air interruption, material blocking, slag filling, etc. caused by the blast furnace tuyere failure.

[0024] Third, the automatic control level is improved: the present invention improves the response speed of the blast furnace accident ventilation, reduces the risk of misjudgment of manual ventilation, and improves the automatic control level of the blast furnace blast ventilation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the blast furnace automatic air diversion control system of the present invention;

[0026] Figure 2 The invention discloses a flow chart of a method for controlling automatic air blowing of a blast furnace. DETAILED DESCRIPTION

[0027] The following is a further description of a blast furnace blast automatic air diversion control system and method of the present invention. Figure 1 As shown, the system includes several blast furnaces and several blast furnace blower units, each blast furnace is equipped with a corresponding blast furnace air supply mother pipe, and each blast furnace blower unit has several air supply ducts respectively connected to the blast furnace air supply mother pipes. Taking four blast furnaces 1BF-4BF and five blast furnace blower units 1BL-5BL of a steel enterprise as an example, there are corresponding four blast furnace air supply mother pipes 9-12, and each blast furnace blower unit has four air supply ducts 1 leading to each blast furnace air supply mother pipe 9-12, and each air supply duct 1 is provided with an air supply switching valve 5. Different from the prior art, it also includes an emergency air displacing mother pipe 2, which has four air displacing ducts 3 respectively connected to the blast furnace air supply mother pipes 9-12, and each air displacing duct 3 is provided with an air displacing valve group, which includes an electric regulating valve 6, a pneumatic butterfly valve 7, and an electric gate valve 8 arranged in sequence. The newly added air displacing pipe 3 can be connected to the corresponding blast furnace air supply mother pipe 9-12 in sequence by taking advantage of the blast furnace air stop opportunity. The position of the air displacing valve group only needs to be connected to the corresponding blast furnace air supply mother pipe 9-12, so that each blower unit 1BL-5BL can perform air displacing for each blast furnace 1BF-4BF, and is not limited to which blower unit is arranged next to. In addition, the emergency air displacing mother pipe 2 is also connected to the discharge pipe 4.

[0028] The control method principle of the blast furnace blast automatic air diversion control system of the present invention is:

[0029] In the production process of multiple blast furnaces, when a blower unit is shut down urgently, it is first automatically determined whether air diversion is needed. If air diversion is needed, the control system selects the best blower unit from the normally operating blower units to divert air to the blast furnace corresponding to the faulty blower (hereinafter referred to as the faulty blast furnace).

[0030] The specific steps are as follows:

[0031] 1. If a blast furnace blower unit fails, determine whether the blower unit is shut down due to a fault or a normal shutdown. If it is judged to be shut down due to a fault, the automatic air diversion start-up condition is met. If the blower unit has other faults, the operating personnel should be reminded to pay special attention (alarms and screen prompts can be made, but automatic air diversion requests will not be triggered). If it is determined that the blower unit is shut down due to a fault and the conditions are met, the system will issue an automatic air diversion request instruction and an alarm, and automatically send an "air supply is abnormal" signal to the faulty blast furnace, so that the blast furnace can start the accident plan in time. Set the "on / off" button for the blower unit so that a certain blower unit can exit the automatic air diversion when it is in a bad state, and the automatic air diversion request will not be triggered, as shown in Example 1.

[0032] 2. The system automatically selects the optimal blower unit for external air distribution. The specific selection logic is as follows:

[0033] First, determine whether the selected blower unit is a normally operating unit and whether its corresponding air damper valve unit is normal; then, among the blower units that meet the above conditions,

[0034] 1. If any of the blower units to be selected is in a constant air volume operation state, then select from the blower units in the constant air volume operation state, and then determine which blower unit to select for air displacement according to the specified air volume and the interlocking blower unit conditions, as shown in Examples 2, 3, and 4;

[0035] 2. If all the selected blower units are in a fixed air pressure state, which blower unit is selected for air displacement is determined according to the specified air volume and the interlocking blast furnace demand conditions, as shown in Examples 5 and 6;

[0036] 3. If the specified air volumes of the selected blower units are the same, the blower unit with the smallest specified oxygen volume is selected for air displacement, as shown in Example 7;

[0037] 4. If the specified air volume and the specified oxygen volume of the selected blower units are the same, then the blower unit with the latest running status and the non-faulty blower unit is selected for air distribution, as shown in Example 8 (according to the status of the blower units, the order of the unit status is pre-defined in the selection logic, and the order of the unit status can be dynamically adjusted. For example, if the No. 5 blower unit is the latest and the best, then No. 5 is selected. However, if the No. 5 blower unit is a faulty unit, then the No. 4 blower unit with the next best status is selected, and so on). Select and distribute air to the outside in sequence;

[0038] 5. If other blower units also have faults and need to be diverted, the faulty blower unit and the blower unit that has diverted air to the outside are no longer listed as alternative blower units, as shown in Example 9 (in addition to the faulty blower unit, another blower unit fails, but it is not the blower unit selected for diverting air to the outside) and Example 10 (the blower unit for diverting air to the outside fails, and reselection is required).

[0039] After the system selects which operating blower unit to perform air diversion, it should display and alarm, and automatically send "air supply alarm" and "air diversion" signals to the faulty blast furnace and the blast furnace that diverts air to the outside, respectively. When the blast furnace sends back a response signal, the "air supply alarm" and "air diversion" signals can be manually turned off. The "automatic air diversion is not allowed" operation function is set. Due to the need for stable production of the blast furnace, a blast furnace does not want any air volume fluctuations in certain specific production processes. In this case, the blast furnace in the production direction sends the "automatic air diversion is not allowed" operation instruction to the blast furnace, which can temporarily lock the automatic external air diversion instruction of the corresponding air supply blower unit of the blast furnace, as shown in Example 11. The blast furnace that is locked for air diversion will be prohibited from operating external air diversion, but will be able to accept automatic air diversion from other blast furnaces normally in the event of a fault, as shown in Example 12.

[0040] 3. According to the selection result, the air displacing valve groups of the faulty blast furnace and the selected blower unit are quickly started simultaneously, so that the selected blower unit automatically displaces air to the blast furnace that supplies air to the faulty blower unit through the corresponding air displacing duct.

[0041] In addition, at startup, the following three safety protections can also be set, including: 1. Operation site selection, priority level: the site takes precedence over the central, the selection of operation authority is at the site machine, the manual air diversion control system takes precedence over the automatic air diversion control system, and the selection of operation authority is in the manual air diversion control system. 2. Operation mode setting. After the operation authority is selected, the operator can control the equipment through the DCS screen button. Set the manual mode or automatic mode as needed before operation. 3. Air diversion system control. For each blast furnace, there are two control modes: "HMI manual" and "automatic". After the air diversion operation is started, the furnace pressure of the blast furnace with external air diversion will drop. The blast operator and the blast furnace operator will adjust the air supply volume in time to ensure the stable production of the blast furnace with external air diversion. The air diversion valve group control program should have an operation protection function to prevent malfunction when the system is not in a condition. At this time, the air diversion valve group control program should automatically determine that the current equipment detection parameters are abnormal and alarm.

[0042] Example 1, 2BL-2BF supplies air. When 2BL fails, 1BL exits automatic air dissipation. 3BL is the optimal external air dissipation unit. Control 3BL to dissipate air, as shown in the following table:

[0043]

[0044]

[0045] Example 2, 1BL-1BF supplies air. When 1BL fails, the selected blower units are all in a constant air pressure state; 2BL is the optimal external air exhaust unit, and 2BL is controlled to exhaust air: as shown in the following table:

[0046] Air supply method Logical reasoning Constant air volume / constant air pressure Specified air volume Specified oxygen amount blast furnace Blower status 1BL-1BF Requirements Constant air volume 6800 21000 Allow wind Fault 2BL-2BF Requirements Constant wind pressure 6100 22000 Allow wind Wind 3BL-3BF Requirements Constant wind pressure 6200 23000 Allow wind 4BL-4BF Requirements Constant wind pressure 5800 24000 Allow wind 5BL-spare

[0047] Example 3, 2BL-2BF supplies air. When 2BL fails, the selected units are all in the constant air volume state; 1BL is the optimal external air exhaust unit, and 1BL is controlled to exhaust air, as shown in the following table:

[0048] Air supply method Logical reasoning Constant air volume / constant air pressure Specified air volume Specified oxygen amount blast furnace Blower status 1BL-1BF Requirements Constant air volume 6100 21000 Allow wind Wind 2BL-2BF Requirements Constant air volume 6200 22000 Allow wind Fault 3BL-3BF Requirements Constant air volume 6300 23000 Allow wind 4BL-4BF Requirements Constant air volume 6400 24000 Allow wind 5BL-spare

[0049] Example 4, 5BL-3BF supplies air. When 5BL fails, the selected units are all in the constant air volume state; 2BL is the optimal external air exhaust unit, and 2BL is controlled to exhaust air, as shown in the following table:

[0050] Air supply method Logical reasoning Constant air volume / constant air pressure Specified air volume Specified oxygen amount blast furnace Blower status 2BL-1BF Requirements Constant air volume 6100 21000 Allow wind Wind 4BL-2BF Requirements Constant air volume 5900 22000 Allow wind 5BL-3BF Requirements Constant air volume 6700 23000 Allow wind Fault 3BL-4BF Requirements Constant air volume 6200 24000 Allow wind 1BL-spare

[0051] Example 5, 2BL-1BF supplies air. When 2BL fails, the selected units are all in a constant air pressure state; 4BL is the optimal external air expulsion unit, and 4BL is controlled to expel air, as shown in the following table:

[0052] Air supply method Logical reasoning Constant air volume / constant air pressure Specified air volume Specified oxygen amount blast furnace Blower status 2BL-1BF Requirements Constant air volume 6800 21000 Allow wind Fault 4BL-2BF Requirements Constant wind pressure 6100 22000 Allow wind Wind 5BL-3BF Requirements Constant wind pressure 6200 23000 Allow wind 3BL-4BF Requirements Constant wind pressure 5800 24000 Allow wind 1BL-spare

[0053] Example 6, 2BL-1BF supplies air. When 2BL fails, the selected units are in the constant air pressure state and the constant air volume state; 5BL is the optimal external air expulsion unit, and 5BL is controlled to expel air, as shown in the following table:

[0054] Air supply method Logical reasoning Constant air volume / constant air pressure Specified air volume Specified oxygen amount blast furnace Blower status 2BL-1BF Requirements Constant air volume 6800 21000 Allow wind Fault 4BL-2BF Requirements Constant wind pressure 6100 22000 Allow wind 5BL-3BF Requirements Constant air volume 6200 23000 Allow wind Wind 3BL-4BF Requirements Constant wind pressure 5800 24000 Allow wind 1BL-spare

[0055] Example 7, 5BL-4BF supplies air. When 5BL fails, the selected units are all in the fixed air volume state, and the specified air volumes are the same; 3BL is the optimal external air expulsion unit, and 3BL is controlled to expel air, as shown in the following table:

[0056] Air supply method Logical reasoning Constant air volume / constant air pressure Specified air volume Specified oxygen amount blast furnace Blower status 3BL-1BF Requirements Constant air volume 6800 21000 Allow wind Wind 4BL-2BF Requirements Constant air volume 6800 22000 Allow wind 1BL-3BF Requirements Constant air volume 6800 23000 Allow wind 5BL-4BF Requirements Constant air volume 6800 24000 Allow wind Fault 2BL-spare

[0057] Example 8, 5BL-4BF supplies air. When 5BL fails, the selected units are all in the fixed air volume state, and the specified air volume and the specified oxygen content are the same; 5BL is the optimal external air expulsion unit, and 5BL is controlled to expel air, as shown in the following table:

[0058] Air supply method Logical reasoning Constant air volume / constant air pressure Specified air volume Specified oxygen amount blast furnace Blower status 3BL-1BF Requirements Constant air volume 6800 22000 Allow wind Fault 4BL-2BF Requirements Constant air volume 6800 22000 Allow wind 1BL-3BF Requirements Constant air volume 6800 22000 Allow wind 5BL-4BF Requirements Constant air volume 6800 22000 Allow wind Wind 2BL-spare

[0059] Example 9, 3BL-1BF supplies air. When 3BL fails, the selected units are all in the fixed air volume state; 3BF does not allow air exchange, 1BL-3BF supplies air, and 1BL is not selected even if it is the best unit; the alternative 5BL is selected as the external air exchange unit, and 5BL is controlled to exchange air, as shown in the following table:

[0060] Air supply method Logical reasoning Constant air volume / constant air pressure Air volume Oxygen blast furnace Blower status 3BL-1BF Requirements Constant air volume 6800 21000 Allow wind Fault 4BL-2BF Requirements Constant air volume 6700 22000 Allow wind 1BL-3BF Requirements Constant air volume 6200 23000 No wind is allowed 5BL-4BF Requirements Constant air volume 6300 24000 Allow wind Wind 2BL-spare

[0061] Example 10, 3BL-1BF supply air, when 3BL fails, the selected units are all in the fixed air volume state; 1BL is the optimal external air expulsion unit, and 1BL is controlled to expel air. If 4BL fails after 5 to 15 seconds, 3BL and 1BL are not selected, 5BL is the optimal external air expulsion unit, and 5BL is controlled to expel air, as shown in the following table:

[0062]

[0063] Example 11, 3BL-1BF supplies air. When 3BL fails, the selected units are all in the fixed air volume state; 3BF does not allow automatic air exchange, 1BL-3BF supplies air, and 1BL is not selected even if it is the best unit; the alternative 5BL is selected as the external air exchange unit, and 5BL is controlled to exchange air, as shown in the following table:

[0064]

[0065] Example 12: The "automatic air blowing not allowed" blast furnace can accept the automatic air blowing of other blast furnaces when the blower fails, as shown in the following table:

[0066]

[0067] Similarly, the different numbers of blast furnaces and blower units involved in patents 201620686442.0, 201420386624.7, 201621173701.6, 201721357882.2, etc. in the background technology can all be transformed and upgraded accordingly using the technology of the present invention.

[0068] In summary, the present invention is applicable to a system in which multiple blast furnace blower units supply air to multiple blast furnaces, effectively improving the response speed of blast furnace accident air diversion, reducing the risk of misjudgment, misoperation and air diversion timeout in manual air diversion, and improving the automatic control level of the blast furnace blast and air diversion system. The present invention successfully realizes the automatic mutual diversion of multiple blast furnaces and multiple blower units, and can ensure that the blast furnace with a faulty blower unit will not have accidents such as air interruption, material sitting, and slag filling under any working conditions because of the existence of the automatic air diversion system, thereby ensuring the safe production of the blast furnace. It can effectively avoid the economic losses caused by the blast furnace shutdown caused by the blast furnace blower accident.

[0069] However, those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. As long as they are within the spirit of the present invention, any changes or modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A blast furnace blast automatic air distribution control system, comprising several blast furnaces and several blast furnace blast units, each blast furnace is equipped with a corresponding blast furnace air supply mother pipe, each blast furnace blast unit has several air supply ducts respectively connected to the blast furnace air supply mother pipes, characterized in that : It also includes an emergency air-extraction main pipe, which has several air-extraction ducts respectively connected to each blast furnace air supply main pipe, and each air-extraction duct is provided with an air-extraction valve group.

2. A blast furnace blast automatic air diversion control system as claimed in claim 1, characterized in that: The air-displacing valve group comprises an electric regulating valve, a pneumatic butterfly valve and an electric gate valve which are arranged in sequence.

3. The blast furnace blast automatic air diversion control system according to claim 1, characterized in that: The emergency air discharging main pipe is also connected to a discharge pipeline.

4. The control method of a blast furnace blast automatic air diversion control system according to claim 1, characterized in that: The following steps are involved: A. If a blast furnace blower unit fails, determine whether the blower unit is automatically shut down due to a fault or manually shut down normally. If it is determined to be automatically shut down due to a fault, the automatic air-pumping start condition is met; B. Automatically select the optimal blower unit for external air dissipation, including the following steps: B1. Determine whether the selected blower unit is a normally operating unit and whether its corresponding air damper valve unit is normal; B2. Among the blower units that meet the condition of B1, if any of the blower units to be selected is in the state of constant air volume, then select from the units in the state of constant air volume operation, and determine which blower unit to select for air displacing according to the specified air volume and the conditions of the interlocked blower units; if all the blower units to be selected are in the state of constant air pressure, then determine which blower unit to select for air displacing according to the specified air volume and the conditions of the interlocked blast furnace demand; if the specified air volumes of the blower units to be selected are the same, then select the blower unit with the smallest specified oxygen content for air displacing; if the specified air volumes and specified oxygen contents of the blower units to be selected are the same, then select the blower unit with the latest relatively running state and a non-faulty blower unit for air displacing; C. Based on the selection result, the air displacing valve groups of the faulty blast furnace and the selected blower unit are started, so that the selected blower unit automatically displaces air to the blast furnace originally supplied with air by the faulty blower unit through the corresponding air displacing duct.

5. The control method of a blast furnace automatic air blowing control system according to claim 4, characterized in that: The step B2 further comprises: If other blower units also have faults and need to be diverted, the faulty blower unit and the blower unit that has already diverted air to the outside will no longer be selected as the blower unit for diverting air to the outside.

6. The control method of a blast furnace blast automatic air diversion control system according to claim 4, characterized in that: The step B also includes: B3. No matter which blower unit is selected for air diversion, corresponding display and alarm will be given, and "air supply alarm" and "air diversion" signals will be automatically sent to the faulty blast furnace and the blast furnace for external air diversion respectively; when the blast furnace sends back a response signal, the "air supply alarm" and "air diversion" signals will be manually turned off.

7. The control method of a blast furnace blast automatic air diversion control system according to claim 4, characterized in that: The step B also includes: setting an "automatic air ventilation is not allowed" operation function to temporarily lock the command of the air supply blower unit corresponding to a blast furnace to automatically blow air to the outside. The blast furnace whose air ventilation is locked will be prohibited from operating to blow air to the outside, but can normally accept automatic air ventilation from other blast furnaces in the event of a fault.

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