Uniform blast and coal injection cooperative control system and method for blast furnace

Abstract

The invention belongs to the technical field of blast furnace smelting, and discloses a uniform blast and coal injection cooperative control system and method for a blast furnace, which can monitor and adjust the flow and concentration of each hot air branch pipe and each coal injection branch pipe in real time, dynamically balance the air-coal ratio of each tuyere outlet, remarkably improve the phenomenon of uneven combustion caused by uneven supply among the tuyeres, and improve the quality of the blast furnace. Local over-combustion or under-combustion is reduced through automatic balance of the air-coal ratio, and the stability and uniformity of combustion reaction are improved. Through closed-loop control, real-time and accurate adjustment of hot air and coal injection quantity is achieved, lag and errors caused by manual adjustment are eliminated, operation fluctuation of the blast furnace is reduced, operation parameters of all tuyeres of the blast furnace tend to be consistent, furnace condition fluctuation caused by local abnormity is effectively avoided, and safety and controllability of overall operation of the blast furnace are improved.

Description

Technical Field

[0001] This invention belongs to the field of blast furnace smelting technology, specifically relating to a blast furnace uniform blast and pulverized coal injection coordinated control system and method. Background Technology

[0002] Pulverized coal injection has become an important means of increasing production capacity, saving energy, reducing consumption, and lowering the coke ratio in modern blast furnace operations, and it is also one of the important measures for regulating the lower part of the blast furnace. Injecting cold pulverized coal into high-speed, high-temperature hot blast is an instantaneous process. During this process, the pulverized coal has a very short residence time in the combustion zone, making complete combustion and gasification quite difficult. If there is too much unburned pulverized coal in the furnace, it will reduce the permeability of the blast furnace burden, and in severe cases, it will cause accumulation in the hearth, resulting in difficulty in lower-level operation or suspended burden. Insufficient pulverized coal injection will cause excessive reaction between hot blast and coke, increasing the coke ratio and lowering various economic and technical indicators. Therefore, improving the combustion efficiency of pulverized coal and reducing the amount of unburned pulverized coal are among the key objectives in current blast furnace operations.

[0003] In actual production, the physical location of the pulverized coal distributor and the blast furnace determines that the length and curvature of each pulverized coal injection branch pipe are different. This results in inconsistent damping characteristics among the pulverized coal injection pipes, leading to uneven distribution of pulverized coal velocity, concentration, and fineness among the various tuyeres. Simultaneously, the different relative positions of the hot blast main pipe and each tuyer cause significant differences in the blast parameters of each branch pipe, resulting in inconsistent hot blast volume at each tuyer. The superposition of these two inhomogeneities often leads to significant differences in blast volume and pulverized coal injection volume between tuyeres along the circumference of the blast furnace. For example, some tuyeres may experience insufficient blast volume and excessive pulverized coal injection, resulting in a lower pulverized coal burnout rate at those tuyeres compared to others. This, in turn, affects the uniform development of the entire combustion zone, leading to an increase in the overall fuel ratio of the blast furnace and reduced operational stability.

[0004] Therefore, it is necessary to improve the uniformity of airflow at each tuyere and adjust the coal injection rate at each tuyere accordingly to solve the problem of low coal pulverization rate at individual tuyeres, and ultimately achieve the goal of matching the airflow and coal injection rate at each tuyere. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of uneven combustion, unstable operation, and increased fuel ratio in blast furnaces caused by uneven distribution of pulverized coal and hot air, and to provide a blast furnace uniform blasting and pulverized coal injection coordinated control system and method.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a blast furnace uniform blasting and pulverized coal injection coordinated control system, including a hot air branch pipe and a pulverized coal injection branch pipe. The pulverized coal injection branch pipe is inserted into the hot air branch pipe and both face the tuyeres outlet. A hot air pressure monitoring sensor, a hot air flow monitoring sensor, and a hot air flow regulating valve are installed on the hot air branch pipe. A pulverized coal concentration monitoring sensor, a pulverized coal mass flow monitoring sensor, and a pulverized coal mass flow regulating valve are installed on the pulverized coal injection branch pipe. The hot air pressure monitoring sensor, the hot air flow monitoring sensor, the hot air flow regulating valve, the pulverized coal concentration monitoring sensor, the pulverized coal mass flow monitoring sensor, and the pulverized coal mass flow regulating valve are all connected to a control unit. The control unit is used to calculate the average flow rate based on the flow rate of all hot air branch pipes, thereby obtaining the difference between the flow rate of each hot air branch pipe and the average flow rate; based on the difference between the flow rate of each hot air branch pipe and the average flow rate, it adjusts the hot air flow regulating valve on the corresponding hot air branch pipe; based on the mass and flow rate of pulverized coal in each pulverized coal injection branch pipe, combined with the flow rate of each hot air branch pipe, it obtains the air-coal ratio at each tuyeres outlet; it calculates the difference between the air-coal ratio at each tuyeres outlet and the preset air-coal ratio of the blast furnace; based on the difference between the air-coal ratio at each tuyeres outlet and the preset air-coal ratio of the blast furnace, it adjusts the pulverized coal mass flow regulating valve on the corresponding pulverized coal injection branch pipe.

[0007] A further improvement of the present invention is that the measurement accuracy of the hot air pressure monitoring sensor, the hot air flow monitoring sensor, the pulverized coal concentration monitoring sensor, and the pulverized coal mass flow monitoring sensor is better than 0.1%, and the repeatability is 0.1%.

[0008] A further improvement of this invention is that the hot air pressure monitoring sensor, hot air flow monitoring sensor, pulverized coal concentration monitoring sensor, and pulverized coal mass flow monitoring sensor all adopt a pipeline measurement form. The measuring inner diameter of the hot air pressure monitoring sensor and the hot air flow monitoring sensor is the same as the inner diameter of the hot air branch pipe, and the measuring inner diameter of the pulverized coal concentration monitoring sensor and the pulverized coal mass flow monitoring sensor is the same as the inner diameter of the coal injection branch pipe.

[0009] A further improvement of this invention is that the flow rate adjustment range of the hot air flow regulating valve is 60-100%, and the flow rate control accuracy is 0.1%. The coal powder mass flow rate regulating valve has a coal powder flow rate adjustment range of 80-100% and a concentration adjustment range of 5-25%.

[0010] A further improvement of this invention is that the valve body material of the hot air flow regulating valve is made of ZG40Cr25Ni20 heat-resistant cast steel.

[0011] A further improvement of the present invention is that the hot air pressure monitoring sensor and the hot air flow monitoring sensor are installed on the straight pipe of the hot air branch pipe. The coal powder concentration monitoring sensor and the coal powder mass flow monitoring sensor are fixed to the coal injection branch pipe by flanges.

[0012] Secondly, the present invention provides a method for coordinated control of uniform blast furnace blasting and pulverized coal injection, comprising the following steps: Obtain the flow rate of hot air in each hot air branch pipe, calculate the average flow rate value based on the flow rate of all hot air branch pipes, and thus obtain the difference between the flow rate of each hot air branch pipe and the average flow rate value. Adjust the hot air flow regulating valve on the corresponding hot air branch pipe according to the difference between the flow rate of each hot air branch pipe and the average flow rate; The mass and flow rate of pulverized coal in each pulverized coal injection branch pipe are obtained, and the air-coal ratio at each tuyer outlet is obtained by combining the flow rate of each hot air branch pipe. Calculate the difference between the air-coal ratio at each tuyer outlet and the preset air-coal ratio for the blast furnace; Based on the difference between the air-coal ratio at each tuyer outlet and the preset air-coal ratio for the blast furnace, the pulverized coal mass flow regulating valve on the corresponding pulverized coal injection branch pipe is adjusted.

[0013] A further improvement of this invention is that, based on the difference between the air-coal ratio at each tuyer outlet and the preset air-coal ratio for the blast furnace, the method for adjusting the pulverized coal mass flow rate regulating valve on the corresponding pulverized coal injection branch pipe is as follows: When the air-coal ratio at the tuyere outlet is less than the preset air-coal ratio for the blast furnace, the opening of the pulverized coal mass flow rate regulating valve on the pulverized coal injection branch pipe should be reduced. When the air-coal ratio at the tuyere outlet is greater than the preset air-coal ratio for the blast furnace, the opening of the pulverized coal mass flow regulating valve on the pulverized coal injection branch pipe is increased.

[0014] A further improvement of the present invention is that, when adjusting the pulverized coal mass flow rate regulating valve of each branch pipe, the hot air flow rate regulating valve of each branch pipe is adjusted first, and then the pulverized coal mass flow rate regulating valve of each branch pipe is adjusted; the pulverized coal mass flow rate regulating valve of the tuyer branch pipe with an air-coal ratio greater than the preset air-coal ratio of the blast furnace is adjusted first.

[0015] A further improvement of the present invention is that the air-coal ratio at each air outlet is equal to the hot air flow rate of each branch pipe divided by the pulverized coal mass flow rate.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention can monitor and adjust the flow rate and concentration of each hot blast branch pipe and pulverized coal injection branch pipe in real time, dynamically balancing the air-coal ratio at each tuyer outlet. This significantly improves the uneven combustion phenomenon caused by uneven supply between tuyeres. The automatic balancing of the air-coal ratio reduces local overburning or underburning, improving the stability and uniformity of the combustion reaction. Through closed-loop control, this invention achieves real-time and precise adjustment of hot blast and pulverized coal injection quantities, eliminating the lag and error caused by manual adjustment, reducing blast furnace operation fluctuations, and making the operating parameters of each tuyer more consistent. This effectively avoids furnace condition fluctuations caused by local anomalies, improving the overall safety and controllability of blast furnace operation. Through the synergistic optimization of pulverized coal injection and hot blast, this invention achieves more complete combustion, promotes the efficient utilization of pulverized coal, reduces redundant air volume and coal consumption, effectively reducing fuel consumption per unit of iron production in the blast furnace. Reduced energy consumption leads to cost savings and reduced carbon emissions, resulting in significant economic and environmental benefits. In conclusion, this invention effectively solves various blast furnace operation problems caused by uneven distribution of hot air and pulverized coal through multi-parameter coordination and dynamic adjustment of hot air and pulverized coal, achieving the technical effects of uniform combustion at the blast furnace tuyeres, stable operation, and reduced fuel ratio. This system has significant advantages in terms of high automation, intelligence, and strong adaptability. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the system components of the present invention; Among them, 1. Hot air pressure monitoring sensor; 2. Hot air flow monitoring sensor; 3. Hot air flow regulating valve; 4. Coal powder concentration monitoring sensor; 5. Coal powder mass flow monitoring sensor; 6. Coal powder mass flow regulating valve; 7. Hot air branch pipe; 8. Coal injection branch pipe. Detailed Implementation

[0018] To further understand the content of this invention, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments are merely illustrative and not limiting of the invention.

[0019] See Figure 1 and Figure 2 A blast furnace uniform blasting and pulverized coal injection coordinated control system includes a hot air branch pipe 7 and a pulverized coal injection branch pipe 8. The pulverized coal injection branch pipe 8 is inserted into the hot air branch pipe 7 and both face the tuyeres outlet. The hot air branch pipe 7 is equipped with a hot air pressure monitoring sensor 1, a hot air flow monitoring sensor 2, and a hot air flow regulating valve 3. The pulverized coal injection branch pipe 8 is equipped with a pulverized coal concentration monitoring sensor 4, a pulverized coal mass flow monitoring sensor 5, and a pulverized coal mass flow regulating valve 6. The hot air pressure monitoring sensor 1, the hot air flow monitoring sensor 2, the hot air flow regulating valve 3, the pulverized coal concentration monitoring sensor 4, the pulverized coal mass flow monitoring sensor 5, and the pulverized coal mass flow regulating valve 6 are all connected to a control unit.

[0020] The control unit is used to calculate the average flow rate value based on the flow rate of all hot air branch pipes 7, thereby obtaining the difference between the flow rate of each hot air branch pipe 7 and the average flow rate value; based on the difference between the flow rate of each hot air branch pipe 7 and the average flow rate value, the hot air flow regulating valve 3 on the corresponding hot air branch pipe 7 is adjusted; based on the mass and flow rate of pulverized coal in each pulverized coal injection branch pipe 8, combined with the flow rate of each hot air branch pipe 7, the air-coal ratio at each tuyeres outlet is obtained; the difference between the air-coal ratio at each tuyeres outlet and the preset air-coal ratio of the blast furnace is calculated; based on the difference between the air-coal ratio at each tuyeres outlet and the preset air-coal ratio of the blast furnace, the pulverized coal mass flow regulating valve 6 on the corresponding pulverized coal injection branch pipe 8 is adjusted.

[0021] A method for coordinated control of uniform blast furnace blast and pulverized coal injection includes the following steps: Step 1: Obtain the flow rate of hot air in each hot air branch pipe 7, calculate the average flow rate value based on the flow rate of all hot air branch pipes 7, and thus obtain the difference between the flow rate of each hot air branch pipe 7 and the average flow rate value.

[0022] Step 2: Adjust the hot air flow regulating valve 3 on the corresponding hot air branch pipe 7 according to the difference between the flow rate of each hot air branch pipe 7 and the average flow rate.

[0023] Step 3: Obtain the mass and flow rate of pulverized coal in each pulverized coal injection branch pipe 8, and combine this with the flow rate of each hot air branch pipe 7 to obtain the air-coal ratio at each air outlet.

[0024] Step 4: Calculate the difference between the air-coal ratio at each tuyer outlet and the preset air-coal ratio for the blast furnace.

[0025] Step 5: Adjust the pulverized coal mass flow regulating valve 6 on the corresponding pulverized coal injection branch pipe 8 according to the difference between the air-coal ratio at each tuyer outlet and the preset air-coal ratio of the blast furnace.

[0026] Example 1: Based on the real-time blast monitoring unit, namely hot air pressure monitoring sensor 1 and hot air flow monitoring sensor 2, the difference between the flow rate in each hot air branch pipe 7 and the average flow rate is measured. According to the magnitude of the difference, the flow rate at the tuyeres with poor uniformity is locally enhanced. This is achieved by employing an integrated valve body collaborative control strategy and automatically controlling the valves on the remaining branch pipes through multiple linkages, thus realizing the goal of uniform hot air flow rate in each branch pipe. Subsequently, using the real-time pulverized coal injection monitoring unit, namely pulverized coal concentration monitoring sensor 4 and pulverized coal mass flow monitoring sensor 5, the pulverized coal mass flow rate in each pulverized coal injection branch pipe is measured, and the difference between the blast-coal ratio at each tuyer and the ratio of total blast volume to total pulverized coal injection volume (set blast-coal ratio) in blast furnace production is calculated. Based on the difference, the opening of the pulverized coal mass flow rate regulating valve 6 on each pulverized coal injection branch pipe of the pulverized coal distributor is adjusted in a targeted manner: when adjusting the pulverized coal mass flow rate regulating valve 6 of each branch pipe, the hot air flow rate regulating valve 3 of each branch pipe is adjusted first, followed by the pulverized coal mass flow rate regulating valve 6 of each branch pipe; the pulverized coal mass flow rate regulating valve 6 of the tuyer branch pipe where the air-coal ratio is greater than the preset air-coal ratio of the blast furnace is adjusted first. The air-coal ratio of each tuyer is equal to the hot air flow rate of each branch pipe divided by the pulverized coal mass flow rate. During the adjustment process, the air volume of each tuyer should first be made to be uniform, and then the pulverized coal mass flow rate of each pulverized coal injection branch pipe 8 is controlled by the pulverized coal mass flow rate regulating valve 6 to gradually bring the air-coal ratio of each tuyer closer to the preset air-coal ratio. The purpose of this adjustment sequence is to ensure the stability of the blast furnace circumferential condition during the adjustment process, to avoid excessive fluctuations, and to ensure the smooth operation of the blast furnace.

[0027] Example 2: The hot air pressure monitoring sensor 1 and hot air flow monitoring sensor 2 installed on each hot air branch pipe of the hot air enclosure, as well as the coal powder concentration monitoring sensor 4 and coal powder mass flow monitoring sensor 5 installed on each coal injection branch pipe of the coal powder distributor, all adopt passive mass sensing instruments and are based on AC charge induction technology to realize real-time and accurate measurement of hot air flow and coal powder mass flow in each hot air branch pipe 7 and each coal injection branch pipe 8.

[0028] The hot air pressure monitoring sensor 1 and hot air flow monitoring sensor 2 in the real-time monitoring unit for blower parameters on the hot air branch pipe have a measurement accuracy better than 0.1% and a repeatability of 0.1%. They adopt an insertion-type measurement structure and are installed on the straight section of the blower branch pipe. The pulverized coal concentration monitoring sensor 4 and pulverized coal mass flow monitoring sensor 5 in the real-time monitoring unit for the pulverized coal distributor branch pipe can accurately measure the flow rate, pulverized coal concentration, and pulverized coal fineness changes in the pulverized coal injection pipeline in real time, with an accuracy better than 0.1% and a repeatability of 0.1%. Both adopt a pipeline-type measurement structure, with the instrument inner diameter completely consistent with the pipeline inner diameter. The blower measuring instruments are designed with high-temperature resistant and oxidation-resistant structures and materials.

[0029] Example 3: The hot air flow regulating valve 3 and the pulverized coal mass flow regulating valve 6 have continuous dynamic flow regulation functions. They can dynamically adjust the valve opening based on real-time monitoring of the blower volume and pulverized coal injection volume. Based on the flow changes fed back by the parameter monitoring unit in real time, they update the difference between the blower flow rate and the average blower flow rate at each air outlet, as well as the difference between the air-coal ratio at each air outlet and the set air-coal ratio. By repeatedly correcting the valve opening, they achieve the goal of matching the blower volume and pulverized coal injection volume at each outlet. The hot air flow rate regulation range in the hot air branch pipe 7 is 60-100%, with a flow control accuracy of 0.1%. The pulverized coal flow rate regulation range in each pulverized coal injection branch pipe 8 of the distributor is 80-100%, and the concentration regulation range is 5-25%. All control methods adopt fieldbus control. Due to the influence of the working environment, the hot air flow regulating valve 3 should have a high-temperature resistant and oxidation-resistant structure and material design. Optional materials include, but are not limited to, ZG40Cr25Ni20 heat-resistant cast steel.

[0030] This invention ensures the uniformity of blast furnace circumferential blast by real-time monitoring of the flow rate in each branch of the hot blast duct and selectively controlling the opening of regulating valves based on the difference between the flow rate in each branch and the average flow rate, thus promoting balanced combustion. It also measures the mass flow rate of pulverized coal in each branch in real-time and coordinates the valve opening of each branch based on the difference between the air-coal ratio in each branch and the set air-coal ratio, achieving a match between the pulverized coal injection rate and air volume at each tuyer and promoting balanced combustion. Furthermore, during the dynamic adjustment of air volume, the invention adjusts the pulverized coal quantity in each branch based on the difference between the air-coal ratio at each tuyer and the set air-coal ratio, ensuring that the air-coal ratio at each tuyer remains within a suitable range during adjustment, guaranteeing furnace stability. The regulating valve of this invention has a high response speed, allowing for rapid adjustment of air volume and coal quantity based on real-time data, reducing lag time and improving control accuracy. Finally, by precisely controlling the ratio of blast volume to pulverized coal injection, this invention reduces the accumulation of unburned pulverized coal in the furnace, promoting complete pulverized coal combustion while lowering pulverized coal injection costs and improving combustion efficiency.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A blast furnace uniform blast and pulverized coal injection coordinated control system, characterized in that, It includes a hot air branch pipe (7) and a coal injection branch pipe (8). The coal injection branch pipe (8) is inserted into the hot air branch pipe (7) and both face the air outlet. The hot air branch pipe (7) is equipped with a hot air pressure monitoring sensor (1), a hot air flow monitoring sensor (2) and a hot air flow regulating valve (3). The coal injection branch pipe (8) is equipped with a coal powder concentration monitoring sensor (4), a coal powder mass flow monitoring sensor (5) and a coal powder mass flow regulating valve (6). The hot air pressure monitoring sensor (1), the hot air flow monitoring sensor (2), the hot air flow regulating valve (3), the coal powder concentration monitoring sensor (4), the coal powder mass flow monitoring sensor (5) and the coal powder mass flow regulating valve (6) are all connected to the control unit. The control unit is used to calculate the average flow rate value based on the flow rate of all hot air branch pipes (7), thereby obtaining the difference between the flow rate of each hot air branch pipe (7) and the average flow rate value; based on the difference between the flow rate of each hot air branch pipe (7) and the average flow rate value, the hot air flow rate regulating valve (3) on the corresponding hot air branch pipe (7) is adjusted; based on the mass and flow rate of pulverized coal in each pulverized coal injection branch pipe (8), combined with the flow rate of each hot air branch pipe (7), the air-coal ratio at each tuyeres outlet is obtained; the difference between the air-coal ratio at each tuyeres outlet and the preset air-coal ratio of the blast furnace is calculated; based on the difference between the air-coal ratio at each tuyeres outlet and the preset air-coal ratio of the blast furnace, the pulverized coal mass flow rate regulating valve (6) on the corresponding pulverized coal injection branch pipe (8) is adjusted.

2. The system for coordinated control of uniform blast furnace blasting and pulverized coal injection according to claim 1, characterized in that, The measurement accuracy of the hot air pressure monitoring sensor (1), the hot air flow monitoring sensor (2), the pulverized coal concentration monitoring sensor (4), and the pulverized coal mass flow monitoring sensor (5) is better than 0.1%, and the repeatability is 0.1%.

3. The system for coordinated control of uniform blast furnace blasting and pulverized coal injection according to claim 1, characterized in that, The hot air pressure monitoring sensor (1), hot air flow monitoring sensor (2), coal powder concentration monitoring sensor (4) and coal powder mass flow monitoring sensor (5) all adopt the pipeline measurement form. The inner diameter of the hot air pressure monitoring sensor (1) and hot air flow monitoring sensor (2) is the same as the inner diameter of the hot air branch pipe (7), and the inner diameter of the coal powder concentration monitoring sensor (4) and coal powder mass flow monitoring sensor (5) is the same as the inner diameter of the coal injection branch pipe (8).

4. The system for coordinated control of uniform blast furnace blasting and pulverized coal injection according to claim 1, characterized in that, The flow rate regulation range of the hot air flow regulating valve (3) is 60-100%, and the flow rate regulation accuracy is 0.1%. The coal powder flow rate adjustment range of the coal powder mass flow regulating valve (6) is 80-100%, and the concentration adjustment range is 5-25%.

5. The system for coordinated control of uniform blast furnace blasting and pulverized coal injection according to claim 1, characterized in that, The valve body of the hot air flow regulating valve (3) is made of ZG40Cr25Ni20 heat-resistant cast steel.

6. The system for coordinated control of uniform blast furnace blasting and pulverized coal injection according to claim 1, characterized in that, The hot air pressure monitoring sensor (1) and the hot air flow monitoring sensor (2) are installed on the straight section of the hot air branch pipe (7); The coal powder concentration monitoring sensor (4) and the coal powder mass flow monitoring sensor (5) are fixed to the coal injection branch pipe (8) by flanges.

7. A method for coordinated control of uniform blast furnace blasting and pulverized coal injection, based on the coordinated control system for uniform blast furnace blasting and pulverized coal injection as described in claim 1, characterized in that, Includes the following steps: The flow rate of hot air in each hot air branch pipe (7) is obtained, and the average flow rate value is calculated based on the flow rate of all hot air branch pipes (7), thereby obtaining the difference between the flow rate of each hot air branch pipe (7) and the average flow rate value. Based on the difference between the flow rate of each hot air branch pipe (7) and the average flow rate, the hot air flow rate regulating valve (3) on the corresponding hot air branch pipe (7) is adjusted; The mass and flow rate of pulverized coal in each pulverized coal injection branch pipe (8) are obtained, and the air-coal ratio at each air outlet is obtained by combining the flow rate of each hot air branch pipe (7). Calculate the difference between the air-coal ratio at each tuyer outlet and the preset air-coal ratio for the blast furnace; Based on the difference between the air-coal ratio at each tuyer outlet and the preset air-coal ratio of the blast furnace, the pulverized coal mass flow regulating valve (6) on the corresponding pulverized coal injection branch pipe (8) is adjusted.

8. The method for coordinated control of uniform blast furnace blasting and pulverized coal injection according to claim 7, characterized in that, The method for adjusting the pulverized coal mass flow regulating valve (6) on the corresponding pulverized coal injection branch pipe (8) based on the difference between the air-coal ratio at each tuyer outlet and the preset air-coal ratio of the blast furnace is as follows: When the air-coal ratio at the tuyere outlet is less than the preset air-coal ratio of the blast furnace, the opening of the pulverized coal mass flow regulating valve (6) on the pulverized coal injection branch pipe (8) is reduced. When the air-coal ratio at the tuyere outlet is greater than the preset air-coal ratio of the blast furnace, the opening of the pulverized coal mass flow regulating valve (6) on the pulverized coal injection branch pipe (8) is increased.

9. The method for coordinated control of uniform blast furnace blasting and pulverized coal injection according to claim 7, characterized in that, When adjusting the pulverized coal mass flow rate regulating valve (6) of each branch pipe, the hot air flow rate regulating valve (3) of each branch pipe should be adjusted first, followed by the pulverized coal mass flow rate regulating valve (6) of each branch pipe; the pulverized coal mass flow rate regulating valve (6) of the tuyeres branch pipe with an air-coal ratio greater than the preset air-coal ratio of the blast furnace should be adjusted first.

10. The method for coordinated control of uniform blast furnace blasting and pulverized coal injection according to claim 7, characterized in that, The air-to-coal ratio at each vent is equal to the hot air flow rate of each branch pipe divided by the pulverized coal mass flow rate.

Images