Online switching method for large blast furnace blower unit

Abstract

The invention belongs to the technical field of large blast furnace blower sets, and relates to an online switching method for the large blast furnace blower sets. Air blowers of the standby air blower set are started, air supply conditions are provided, before the air blower set is switched on line, the air blowers of the operating air blower set are switched from an automatic control mode to a manual control mode, and air supply flow values are recorded and serve as condition parameters during air mixing and splitting; the air blower stationary blade angle and the anti-surge valve opening degree of the standby air blower set are adjusted, so that the exhaust pressure of the standby air blower set is 4 kPa to 8 kPa higher than the air supply pressure of the operation air blower set; air outlet valves and air supply valves of the standby air blower sets are fully opened in sequence, and air mixing of the two air blower sets is achieved; the blast furnace side air supply flow serves as the reference, and loads of the two air blower sets are transferred. The on-line switching method for the large blast furnace blower unit is simple in step, ensures the effectiveness and reliability of the on-line switching process of the blower unit, and ensures the stability of the air volume and the air pressure and the safe production of the blast furnace.

Description

Technical Field

[0001] The invention belongs to the technical field of large-scale blast furnace blower units, and more specifically, relates to an online switching method for large-scale blast furnace blower units. Background Art

[0002] The blower unit is the power heart of blast furnace smelting production. Whether the air volume and pressure of the blower unit are stable will directly affect the normal production of the blast furnace. The blower unit is a large-scale rotating power machinery. In practice, the operation of the blower unit requires the arrangement of mode adjustment, planned maintenance, fault handling and other operations, that is, the operation of the blower unit needs to exit the air supply and shut down. Since the blast furnace production is continuous and uninterrupted, the operation of the blower unit to exit the air supply must be carried out. The blower unit must be switched online, that is, the standby blower unit is activated to replace the blower unit that needs to be shut down. The online switching of the blast furnace blower unit is relatively complex in system operation and has certain safety risks. It generally requires the collaboration of multiple people, one person to coordinate and command, and the other two to operate two blower units respectively. The switching process has many links, high parameter monitoring requirements, and difficult operation and coordination. Once a mistake occurs, it will cause the air volume and pressure to fluctuate greatly during the switching process, which will have a direct impact on the blast furnace production. As the smelting intensity continues to increase, large blast furnaces have higher and higher requirements for the stability of air volume and pressure. How to ensure the safety and stability of air volume and pressure during the online switching process of the blower unit is a problem that the blast furnace air supply system must face and must solve. Due to the many unsafe and unreliable conditions in the existing online switching methods of the blower unit, most domestic metallurgical enterprises choose to switch the blower unit after the blast furnace has finished iron production, and reduce the air supply parameters to avoid the safety risks of sudden drop of suspended materials and backflow of slag and iron into the air inlet sleeve in the blast furnace. However, this method has obvious disadvantages: if the running blower unit fails and needs to be switched immediately and arranged for shutdown, this method cannot be applied. On the other hand, for normal production blast furnaces, reducing the air supply parameters after iron production will also have a certain impact on blast furnace output and furnace stability.

[0003] In the existing online switching method of the blower unit, when performing the load transfer operation between the operating blower unit and the standby blower unit, the air supply valve of the standby blower unit needs to be gradually opened and the anti-surge valve needs to be gradually closed. At the same time, the anti-surge valve of the operating blower unit needs to be gradually opened. It is difficult to coordinate the various operations. The loading amount of the standby blower unit and the unloading amount of the operating blower unit are very likely to be unbalanced, resulting in abnormal fluctuations in the air volume and pressure of the blast furnace. Furthermore, in the load transfer operation, the existing technology uses the air pressure as a tracking and monitoring parameter. It is necessary to track, monitor and adjust the changes in the exhaust pressure, supply air pressure and the like of the standby blower unit and the operating blower unit accordingly. Since the air supplied to the blast furnace is a compressible gas, the change in air pressure usually lags behind the change in air volume. Using the air pressure as a monitoring parameter for load transfer operation will inevitably lead to abnormal fluctuations in the air volume of the blast furnace. When performing the mixed air decoupling operation, one method is to use the closing signal of the check valve of the running blower unit as the decoupling condition. Since the check valve of the running blower unit has been under the exhaust pressure before shutdown, it is difficult to reach the closed position and send a closing signal in practice, resulting in the mixed air decoupling operation being unable to be performed due to the lack of conditions. Another method is to use the zero air flow rate of the running blower unit as the decoupling condition. Since the air flow rate measurement signal will have a large error at small values, and the blower unit usually cuts off the small flow rate signal, using the zero air flow rate as the mixed air decoupling condition may cause the running blower unit load to be decoupled without 100% transfer, which will cause fluctuations in the blast furnace air volume and pressure.

[0004] Since there is a technology in the prior art named "a method for switching between main and standby blowers" and with a publication (announcement) number of "CN113446516A", the technology relates to the field of smelting technology, and specifically discloses a method for switching between main and standby blowers, the method comprising adjusting the standby air supply component so that the exhaust pressure P2 of the standby air supply fan is greater than the exhaust pressure P1 of the main air supply fan; opening the standby air supply check valve; gradually opening the standby air supply valve, gradually opening the first isolation valve to full open, and adjusting the air supply pressure P3 to the initial value by adjusting the main air supply component and the standby air supply component; gradually closing the main air supply valve to full close, and when the air supply pressure P3 drops, adjusting the standby air supply component to increase the air supply pressure P3 to the initial value. The present invention opens the standby air supply check valve before starting the first isolation valve to avoid the impact of the standby air supply check valve on the blast furnace caused by the sudden opening of the standby air supply check valve. By gradually closing the main air supply valve, the exhaust pressure P1 of the main air supply fan is kept greater than the air supply pressure P3 to avoid wind backflow, which may cause the main air supply check valve to suddenly close and cause impact on the blast furnace. However, this technology does not involve the technical solution of this application. Summary of the invention

[0005] The technical problem to be solved by the present invention is: in view of the deficiencies in the prior art, a method for online switching of a large blast furnace blower unit is provided which has simple steps, ensures the effectiveness and reliability of the online switching process of the blower unit, ensures the stability of the air volume and pressure and the safe production of the blast furnace.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is:

[0007] The present invention is an online switching method for a large blast furnace blower unit. The switching steps of the online switching method for a large blast furnace blower unit are as follows:

[0008] S1. Mix the standby blower unit with the running blower unit: Start the blower of the standby blower unit and meet the air supply conditions. Since the large blast furnace blower unit adopts constant air volume or constant air pressure automatic control, in order to prevent the change of the air supply flow rate or air supply pressure of the running blower unit during the switching process, which will cause the stator blade angle of the blower to track the change, and the stator blade angle tracking change will cause the load of the running blower unit to be unable to transfer, before the blower unit is switched online, first switch the blower of the running blower unit from the automatic control mode to the manual control mode, and record the air supply flow value of the air supply pipeline of the running blower unit as the condition parameter for air mixing decoupling;

[0009] S2. According to the operating parameters of the blower stator blade angle and air supply pressure of the operating blower unit, adjust the stator blade angle and anti-surge valve opening of the standby blower unit so that the exhaust pressure of the standby blower unit is 4kPa-8kPa higher than the air supply pressure of the operating blower unit;

[0010] S3. Fully open the air outlet valve of the standby blower unit, and the check valve of the standby blower unit will automatically open due to the exhaust pressure. Then fully open the air supply valve of the standby blower unit, and the standby blower unit and the running blower unit will achieve mixed air.

[0011] S4. After the two blower units mix the air, load transfer can be carried out.

[0012] When transferring load, the air supply flow value on the blast furnace side is used as the coordinated operation basis of the anti-surge valve of the standby blower unit and the anti-surge valve of the operating blower unit. The anti-surge valve of the standby blower unit is gradually closed to load, and the air supply flow of the air supply pipeline of the standby blower unit is gradually increased. At the same time, the anti-surge valve of the operating blower unit is gradually opened to reduce the load, and the air supply flow of the air supply pipeline of the operating blower unit is gradually reduced until the air supply flow of the air supply pipeline of the standby blower unit is equal to the air supply flow value recorded before mixing of the operating blower unit, indicating that the load of the blast furnace air supply has been transferred 100% from the operating blower unit to the standby blower unit, that is, the load transfer work is completed.

[0013] During load transfer, if the anti-surge valves of the standby blower unit have all been closed and the air flow rate of the air supply pipeline of the standby blower unit still does not meet the requirements, increase the angle of the blower stator blades of the standby blower unit to increase the air flow rate of the air supply pipeline of the standby blower unit.

[0014] In step S2, affected by valve and pipe resistance, after the check valve and the air outlet valve of the same blower unit are opened, the exhaust pressure is slightly higher than the supply air pressure, and the difference between the two is less than 8kPa.

[0015] The blower group includes a running blower group and a standby blower group.

[0016] The blower of the standby blower group is connected to the standby blower group air supply pipeline, the standby blower group air supply pipeline is provided with a standby blower group exhaust pressure measurement point, and the standby blower group exhaust pressure measurement point is connected to a pressure sensor; the blower of the running blower group is connected to the running blower group air supply pipeline, the running blower group air supply pipeline is provided with an running blower group exhaust pressure measurement point, and the running blower group exhaust pressure measurement point is connected to a pressure sensor.

[0017] The standby blower group air supply pipeline is provided with a standby blower group air supply flow measurement point, and the standby blower group air supply flow measurement point is connected to a flow sensor; the running blower group air supply pipeline is provided with an running blower group air supply flow measurement point, and the running blower group air supply flow measurement point is connected to a flow sensor.

[0018] The standby blower group air supply pipeline of the standby blower group is connected to the standby blower group anti-surge valve through a branch pipe, and the operating blower group air supply pipeline of the operating blower group is connected to the operating blower group anti-surge valve through a branch pipe.

[0019] The standby blower group air supply pipeline of the standby blower group is connected to the standby blower group check valve, and the operating blower group air supply pipeline of the operating blower group is connected to the operating blower group check valve.

[0020] The air supply pipeline of the standby blower group and the air supply pipeline of the operating blower group are connected to the air supply main, and the air supply main is connected to the blast furnace.

[0021] The air supply main pipe connected to the blast furnace is provided with a blast furnace side air supply flow measurement point, and the blast furnace side air supply flow measurement point is connected to a flow sensor.

[0022] The technical solution of the present invention is adopted, and the working principle and beneficial effects are as follows:

[0023] The online switching method for large-scale blast furnace blower units described in the present invention aims at the deficiencies in the prior art and proposes an improved technical solution. The main innovations are as follows: 1) The present invention uses the blast furnace side air volume as a monitoring parameter to transfer the load during the switching process between the operating blower unit and the standby blower unit. There is no need to monitor and adjust the exhaust pressure and supply air pressure of the blower unit. This method is simpler, more effective, safer and more reliable than the prior art method that uses air pressure as a monitoring parameter. The stability of the blast furnace air volume and air pressure during the switching process is greatly improved. 2) Both the air supply valve and the air outlet valve are operated in a direct full-open or full-closed manner. There is no need to frequently adjust their openings. The load transfer process only operates the anti-surge valves of the operating blower unit and the standby blower unit, which greatly simplifies the operation process and reduces the difficulty of coordinated operation. It can not only avoid the fluctuation of air volume and air pressure during the online switching process of the blower unit, but also significantly improve the work efficiency. 3) The air flow rate of the standby blower unit is equal to the air flow rate of the running blower unit before the switchover as the mixed air decoupling condition, which is easy to accurately grasp and effectively implement, with strong operability, high safety and reliability. 4) The switchover time of the blower unit is not limited by the blast furnace production conditions, and there is no need to choose after the blast furnace has finished iron production and reduce the air supply parameters. It has a wide range of adaptability, strong timeliness, and can avoid the impact of reducing the air supply parameters on the blast furnace output and furnace conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The following is a brief description of the contents and symbols in the drawings of this specification:

[0025] Figure 1 It is a structural schematic diagram of the online switching system of the large blast furnace blower unit according to the present invention;

[0026] The symbols in the accompanying drawings are:

[0027] A--operating blower unit; B--standby blower unit;

[0028] 1, 2--blower; 3, 4--exhaust pressure measurement point; 5, 6--anti-surge valve; 7, 8--check valve; 9, 10--air outlet valve; 11, 12--air supply pressure measurement point; 13, 14--air supply flow measurement point; 15, 16--air supply valve; 17, 18--air supply pipeline; 19--air supply main pipe; 20--blast furnace side air supply flow measurement point; 21--blast furnace. DETAILED DESCRIPTION

[0029] The following is a description of the embodiments to further explain the specific implementation of the present invention, such as the shape, structure, relative position and connection relationship between the components involved, the function and working principle of each component.

[0030] The present invention is an online switching method for a large blast furnace blower unit. The switching steps of the online switching method for a large blast furnace blower unit are as follows:

[0031] S1. Mix the standby blower unit B with the running blower unit A: Start the blower of the standby blower unit and meet the air supply conditions. Since the large blast furnace blower unit adopts constant air volume or constant air pressure automatic control, in order to prevent the change of the air supply flow rate or air supply pressure of the running blower unit during the switching process, which will cause the stator blade angle of the blower to track the change, because the stator blade angle tracking change will cause the load of the running blower unit to be unable to transfer, before the blower unit is switched online, first switch the blower of the running blower unit from the automatic control mode to the manual control mode, and record the air supply flow value of the air supply pipeline of the running blower unit as the condition parameter for air mixing decoupling;

[0032] S2. According to the operating parameters of the blower stator blade angle and air supply pressure of the operating blower unit, adjust the stator blade angle and anti-surge valve opening of the standby blower unit so that the exhaust pressure of the standby blower unit is 4kPa-8kPa higher than the air supply pressure of the operating blower unit;

[0033] S3. Fully open the air outlet valve of the standby blower unit, and the check valve of the standby blower unit will automatically open due to the exhaust pressure. Then fully open the air supply valve of the standby blower unit, and the standby blower unit B and the running blower unit A will achieve mixed air.

[0034] S4. After the two blower units mix the air, load transfer can be carried out.

[0035] When the load is transferred, the air flow rate value on the blast furnace side is used as the coordinated operation benchmark of the anti-surge valve of the standby blower unit and the anti-surge valve of the running blower unit, the anti-surge valve of the standby blower unit is gradually closed to load, the air flow rate of the air supply pipeline of the standby blower unit is gradually increased, and the anti-surge valve of the running blower unit is gradually opened to reduce the load, and the air flow rate of the air supply pipeline of the running blower unit is gradually reduced until the air flow rate of the air supply pipeline of the standby blower unit is equal to the air flow rate value recorded before the air mixing of the running blower unit, indicating that the load of the blast furnace air supply has been 100% transferred from the running blower unit to the standby blower unit, that is, the load transfer work is completed. The above steps propose an improved technical solution for the deficiencies in the prior art. The main innovations of this step are as follows: 1) The present invention uses the blast furnace side air volume as a monitoring parameter to transfer the load during the switching process between the operating blower unit and the standby blower unit. It is not necessary to monitor and adjust the exhaust pressure and air supply pressure of the blower unit. It is simpler, more effective, safer and more reliable than the existing technical method that uses air pressure as a monitoring parameter. The stability of the blast furnace air volume and air pressure during the switching process is greatly improved. 2) Both the air supply valve and the air outlet valve are operated in a direct full-open or full-closed manner. There is no need to frequently adjust their openings. The load transfer process only operates the anti-surge valves of the operating blower unit and the standby blower unit, which greatly simplifies the operation process and reduces the difficulty of coordinated operation. It can not only avoid the fluctuation of air volume and air pressure during the online switching process of the blower unit, but also significantly improve the work efficiency. 3) The air supply flow rate of the standby blower unit is equal to the air supply flow rate of the operating blower unit before the switching as the mixed air decoupling condition, which is easy to accurately grasp and effectively implement, with strong operability and high safety and reliability. 4) The blower unit switching time is not limited by the blast furnace production conditions, and there is no need to select the time after the blast furnace has finished iron production and reduce the air supply parameters. It has a wide range of applications and strong timeliness, and can avoid the impact of reducing the air supply parameters on the blast furnace output and furnace conditions. The large-scale blast furnace blower unit online switching method of the present invention has simple steps, ensures the effectiveness and reliability of the blower unit online switching process, ensures the stability of air volume and pressure, and ensures safe production of the blast furnace.

[0036] In the steps of the present invention, when performing load transfer work, if the anti-surge valves of the standby blower unit have been completely closed, and the air supply flow of the air supply pipeline of the standby blower unit still does not meet the requirements, the angle of the blower stator blades of the standby blower unit is increased to increase the air supply flow of the air supply pipeline of the standby blower unit.

[0037] In step S2, affected by valve and pipe resistance, after the check valve and the air outlet valve of the same blower unit are opened, the exhaust pressure is slightly higher than the supply air pressure, and the difference between the two is less than 8kPa.

[0038] The blower group includes a running blower group and a standby blower group.

[0039] The blower of the standby blower group is connected to the standby blower group air supply pipeline, the standby blower group air supply pipeline is provided with a standby blower group exhaust pressure measurement point, and the standby blower group exhaust pressure measurement point is connected to a pressure sensor; the blower of the running blower group is connected to the running blower group air supply pipeline, the running blower group air supply pipeline is provided with an running blower group exhaust pressure measurement point, and the running blower group exhaust pressure measurement point is connected to a pressure sensor. The standby blower group air supply pipeline is provided with a standby blower group air supply flow measurement point, and the standby blower group air supply flow measurement point is connected to a flow sensor; the running blower group air supply pipeline is provided with an running blower group air supply flow measurement point, and the running blower group air supply flow measurement point is connected to a flow sensor. The standby blower group air supply pipeline of the standby blower group is connected to the standby blower group anti-surge valve through a branch pipe, and the running blower group air supply pipeline of the running blower group is connected to the running blower group anti-surge valve through a branch pipe. The standby blower group air supply pipeline of the standby blower group is connected to the standby blower group check valve, and the operating blower group air supply pipeline of the operating blower group is connected to the operating blower group check valve. The standby blower group air supply pipeline and the operating blower group air supply pipeline are connected to the air supply pipe, and the air supply pipe is connected to the blast furnace. The air supply pipe connected to the blast furnace is provided with a blast furnace side air supply flow measurement point, and the blast furnace side air supply flow measurement point is connected to a flow sensor. The above steps are uniquely set for the structure. The blower of the running blower group is connected to one end of the air supply pipeline of the running blower group, and the air supply pipeline of the running blower group is sequentially provided with an exhaust pressure measurement point, an anti-surge valve, a check valve, an air outlet valve, an air supply pressure measurement point, an air supply flow measurement point, and an air supply valve; the blower of the standby blower group is connected to one end of the air supply pipeline of the standby blower group, and the air supply pipeline of the standby blower group is sequentially provided with an exhaust pressure measurement point, an anti-surge valve, a check valve, an air outlet valve, an air supply pressure measurement point, an air supply flow measurement point, and an air supply valve, and the other end of the air supply pipeline of the running blower group and the other end of the air supply pipeline of the standby blower group are connected to an air supply main, the air supply main is connected to a blast furnace, and an air supply flow measurement point on the blast furnace side is provided on the air supply main. In this way, the above structure can conveniently implement the method of the present invention and effectively solve the problems in the prior art.

[0040] Specifically, the specific implementation method of the online switching method of the large blast furnace blower unit of the present invention is as follows:

[0041] 1) Start the blower of the standby blower unit and ensure air supply conditions.

[0042] 2) Switch the blower of the blower group from automatic control mode to manual control mode, and record its air flow value.

[0043] 3) According to the operating parameters of the blower stator blade angle and air supply pressure of the running blower unit, adjust the blower stator blade angle and anti-surge valve opening of the standby blower unit so that its exhaust pressure is 4kPa-8kPa higher than the air supply pressure of the running blower unit.

[0044] 4) Fully open the air outlet valve and air supply valve of the standby blower unit in sequence to achieve air mixing between the standby blower unit and the operating blower unit.

[0045] 5) Taking the current air supply flow rate on the blast furnace side as the benchmark for the load transfer process, coordinate the anti-surge valves of the operating blower unit and the standby blower unit, gradually close the anti-surge valve of the standby blower unit to load, and gradually open the anti-surge valve of the operating blower unit to reduce the load, perform load transfer, and keep the air supply flow rate on the blast furnace side stable.

[0046] 6) When the air flow rate of the standby blower unit is equal to the air flow rate recorded before the air mixing of the running blower unit, it means that the load of the blast furnace air supply has been 100% transferred from the running blower unit to the standby blower unit, that is, the load transfer work is completed. If the anti-surge valve of the standby blower unit has been completely closed, and its air flow rate still does not meet the requirements, the angle of the blower stator blades of the standby blower unit can be appropriately increased.

[0047] 7) Close the air supply valve and air outlet valve of the running blower unit, the running blower unit is decoupled and the online switching work of the blower unit is completed.

[0048] After adopting the method of the present invention, the operation process is greatly simplified and the operation difficulty is greatly reduced. Previously, the online fan switching operation required about 30 minutes, and the method of the present invention can be completed within 10 minutes. The fan switching time is not limited by the blast furnace production conditions, and there is no need to select the blast furnace after the iron is finished and reduce the air supply parameters, so as to avoid the influence of reducing the air supply parameters on the blast furnace output and furnace conditions. The method of the present invention is novel in technology, simple in operation, wide in application range, and high in safety and reliability.

[0049] The above is an exemplary description of the present invention. Obviously, the specific implementation of the present invention is not limited to the above-mentioned method. As long as various improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A method for online switching of a large blast furnace blower unit, characterized in that: The switching steps of the online switching method for large blast furnace blower units are as follows: S1. Mix the standby blower unit (B) with the running blower unit (A): Start the blower of the standby blower unit and meet the air supply conditions. Since the large blast furnace blower unit adopts constant air volume or constant air pressure automatic control, in order to prevent the change of the air supply flow rate or air supply pressure of the running blower unit during the switching process, which will cause the stator blade angle of the blower to track the change, and the stator blade angle tracking change will cause the load of the running blower unit to be unable to transfer, before the blower unit is switched online, first switch the blower of the running blower unit from the automatic control mode to the manual control mode, and record the air supply flow value of the air supply pipeline of the running blower unit as the condition parameter for air mixing decoupling; S2. According to the operating parameters of the blower stator blade angle and air supply pressure of the operating blower unit, the stator blade angle and the anti-surge valve opening of the standby blower unit are adjusted so that the exhaust pressure of the standby blower unit is higher than the air supply pressure of the operating blower unit; S3. Fully open the air outlet valve of the standby blower unit, and the check valve of the standby blower unit will automatically open due to the exhaust pressure. Then fully open the air supply valve of the standby blower unit, and the standby blower unit (B) and the running blower unit (A) will be mixed with each other. S4. After the two blower units mix the air, load transfer can be carried out.

2. The method for online switching of a large blast furnace blower unit according to claim 1, characterized in that: When transferring load, the air supply flow value on the blast furnace side is used as the coordinated operation basis of the anti-surge valve of the standby blower unit and the anti-surge valve of the operating blower unit. The anti-surge valve of the standby blower unit is gradually closed to load, and the air supply flow of the air supply pipeline of the standby blower unit is gradually increased. At the same time, the anti-surge valve of the operating blower unit is gradually opened to reduce the load, and the air supply flow of the air supply pipeline of the operating blower unit is gradually reduced until the air supply flow of the air supply pipeline of the standby blower unit is equal to the air supply flow value recorded before mixing of the operating blower unit, indicating that the load of the blast furnace air supply has been transferred 100% from the operating blower unit to the standby blower unit, that is, the load transfer work is completed.

3. The method for online switching of a large blast furnace blower unit according to claim 2, characterized in that: During load transfer, if the anti-surge valves of the standby blower unit have all been closed and the air flow rate of the air supply pipeline of the standby blower unit still does not meet the requirements, increase the stator blade angle of the blower of the standby blower unit to increase the air flow rate of the air supply pipeline of the standby blower unit.

4. The method for online switching of a large blast furnace blower unit according to claim 1 or 2, characterized in that: In step S2, affected by valve and pipe resistance, after the check valve and the air outlet valve of the same blower unit are opened, the exhaust pressure is slightly higher than the supply air pressure, and the difference between the two is less than 8kPa.

5. The method for online switching of a large blast furnace blower unit according to claim 1 or 2, characterized in that: The blower group includes a running blower group and a standby blower group.

6. The method for online switching of a large blast furnace blower unit according to claim 5, characterized in that: The blower of the standby blower group is connected to the standby blower group air supply pipeline, the standby blower group air supply pipeline is provided with a standby blower group exhaust pressure measurement point, and the standby blower group exhaust pressure measurement point is connected to a pressure sensor; the blower of the running blower group is connected to the running blower group air supply pipeline, the running blower group air supply pipeline is provided with an running blower group exhaust pressure measurement point, and the running blower group exhaust pressure measurement point is connected to a pressure sensor.

7. The method for online switching of a large blast furnace blower unit according to claim 6, characterized in that: The standby blower group air supply pipeline is provided with a standby blower group air supply flow measurement point, and the standby blower group air supply flow measurement point is connected to a flow sensor; the running blower group air supply pipeline is provided with an running blower group air supply flow measurement point, and the running blower group air supply flow measurement point is connected to a flow sensor.

8. The method for online switching of a large blast furnace blower unit according to claim 6, characterized in that: The standby blower group air supply pipeline of the standby blower group is connected to the standby blower group anti-surge valve through a branch pipe, and the operating blower group air supply pipeline of the operating blower group is connected to the operating blower group anti-surge valve through a branch pipe.

9. The method for online switching of a large blast furnace blower unit according to claim 6, characterized in that: The standby blower group air supply pipeline of the standby blower group is connected to the standby blower group check valve, and the operating blower group air supply pipeline of the operating blower group is connected to the operating blower group check valve.

10. The method for online switching of a large blast furnace blower unit according to claim 6, characterized in that: The air supply pipeline of the standby blower group and the air supply pipeline of the operating blower group are connected to the air supply main, and the air supply main is connected to the blast furnace; the air supply main connected to the blast furnace is provided with a blast furnace side air supply flow measurement point, and the blast furnace side air supply flow measurement point is connected to a flow sensor.

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