Pulverized coal preheating system and blast furnace coal injection hot delivery process based on furnace slag sensible heat utilization

Abstract

The invention relates to a pulverized coal preheating system and a blast furnace coal injection hot delivery process based on furnace slag sensible heat utilization, the pulverized coal preheating system comprises a high-temperature furnace slag storage device and a pulverized coal preheating device, the pulverized coal preheating device is arranged in the high-temperature furnace slag storage device, high-temperature furnace slag is stored in the high-temperature furnace slag storage device, and the heat of the furnace slag is used for preheating pulverized coal. The pulverized coal preheating system is used for preheating pulverized coal, the preheating temperature of the pulverized coal reaches 200 DEG C or above, and the problem that the preheating temperature of the pulverized coal is too low is effectively solved.

Description

Technical Field

[0001] This invention relates to the field of iron and steel smelting technology, and more specifically, to a pulverized coal preheating system and a blast furnace pulverized coal injection hot delivery process based on the utilization of sensible heat from slag. Background Technology

[0002] Pulverized coal injection (PCI) technology is a smelting process that injects pulverized coal into the blast furnace tuyere to replace part of the coke. Its core principle is to provide heat and a reducing agent through the combustion of pulverized coal, thus optimizing the ironmaking process. Pulverized coal is transported from the injection tank through pipelines to the blast furnace PCI distributor. The distributor then distributes the coal according to the number of blast furnace tuyeres, injecting it into the blast furnace tuyere through the injection lances. The pulverized coal burns rapidly upon encountering the high-temperature blast air in the tuyere area, providing heat energy for the blast furnace. During PCI, the pulverized coal undergoes preheating during the pulverization stage to reduce its moisture content and prepare it for subsequent pulverization. This preheating is typically achieved using hot blast stove flue gas, with a preheating temperature usually below 85°C. Existing PCI preheating technologies mostly use hot blast stove flue gas for preheating, with preheating temperatures below 100°C. When pulverized coal enters the blast furnace tuyeres, it burns rapidly under the high pressure, high temperature, and high speed of the hot blast, typically within tens of milliseconds or even less. This combustion consumes a significant amount of heat energy from the hot blast, reducing its effective energy. When the pulverized coal mixes with the hot blast, it is first heated and then combusted. However, because the hot blast travels at high speeds (typically 200 m / s or faster), much of the pulverized coal is not heated in time to burn before entering the blast furnace's burden zone and adhering to it. This reduces the heat release during combustion and negatively impacts furnace operation.

[0003] Under current technological conditions, it is difficult to raise the temperature of pulverized coal to above 200℃ before it enters the blast furnace. This makes complete combustion of pulverized coal in the tuyeres area difficult, and no technology has been reported to achieve complete combustion of pulverized coal at the tuyeres. Under existing technological conditions, there are processes that use nitrogen to heat and inject pulverized coal, but these processes are complex and costly. In particular, during the pulverized coal heating process, poor control of the heating energy can easily lead to excessively high local temperatures, causing spontaneous combustion and affecting the safety of the pulverized coal injection system.

[0004] Therefore, this invention proposes a pulverized coal preheating system and a blast furnace pulverized coal injection hot delivery process based on the utilization of sensible heat from slag to solve the above problems. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a pulverized coal preheating system and a blast furnace pulverized coal injection hot delivery process based on the utilization of sensible heat from slag. The pulverized coal preheating system preheats the pulverized coal to a temperature of over 200°C, effectively solving the problem of excessively low pulverized coal preheating temperature.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A pulverized coal preheating system includes a high-temperature slag storage device and a pulverized coal preheating device; The high-temperature slag storage device includes a high-temperature slag storage pit and a heat-reflective baffle. The heat-reflective baffle covers the opening of the high-temperature slag storage pit. A slag inlet is provided on the side of the high-temperature slag storage pit, and a slag outlet is provided on the bottom. The slag inlet on the side is connected to the blast furnace slag ditch through a connecting slag ditch, and the slag outlet on the bottom is connected to the slag treatment system through a discharge ditch. Both the slag inlet and the slag outlet are equipped with control isolation baffles. The pulverized coal preheating device includes a pulverized coal preheater, a hot-charge pulverized coal injection inlet pipe, and a hot-charge pulverized coal injection outlet pipe. The pulverized coal preheating device is located in the blast furnace slag storage pit and below the heat reflector baffle. The entire pulverized coal preheating device is positioned above the slag inlet. One end of the hot-charge pulverized coal injection inlet pipe is connected to the original pulverized coal injection pipe, and the other end passes through the high-temperature slag storage pit and connects to the pulverized coal preheater. One end of the hot-charge pulverized coal injection outlet pipe is connected to the blast furnace pulverized coal distributor, and the other end passes through the high-temperature slag storage pit and connects to the pulverized coal preheater. Both the hot-charge pulverized coal injection inlet pipe and the hot-charge pulverized coal injection outlet pipe are equipped with control valves and check valves.

[0007] In one embodiment, the heat reflector baffle is provided with one or more hot gas vents, and the hot gas vents are equipped with valves.

[0008] In one embodiment, the pulverized coal preheating system further includes a first temperature thermocouple and a second temperature thermocouple. The first temperature thermocouple is disposed on the inner wall of the high-temperature slag storage pit to detect the temperature inside the high-temperature slag storage pit, and the second temperature thermocouple is disposed in the hot coal injection outlet pipe to detect the temperature of the discharged pulverized coal.

[0009] In one embodiment, the temperature thermocouple is at the same height as the slag inlet.

[0010] In one embodiment, within the high-temperature slag storage pit, both the hot-charge pulverized coal inlet pipe and the hot-charge pulverized coal outlet pipe are located above the slag inlet, and the height difference between the hot-charge pulverized coal inlet pipe / hot-charge pulverized coal outlet pipe and the slag inlet is 0.5-1 m.

[0011] In one embodiment, the interior of the high-temperature slag storage pit is a cylindrical structure, with a depth of 1.5-2 m and a diameter of 1-1.2 m.

[0012] The blast furnace pulverized coal injection heat delivery process based on the utilization of sensible heat from slag is as follows: When blast furnace operation requires preheating of pulverized coal: During the blast furnace slag and iron tapping process, liquid slag flows from the blast furnace slag ditch into the slag treatment system. After the high-temperature liquid slag has been flowing into the slag treatment system for 5-10 minutes and the slag flow and temperature are qualified, the control isolation baffle corresponding to the slag inlet of the high-temperature slag storage pit is opened. At the same time, the control isolation baffle of the slag outlet is opened to confirm that the slag in the pit can be discharged normally. Then the control isolation baffle of the slag outlet is closed, and the high-temperature slag storage pit begins to store high-temperature slag. When the depth of the high-temperature slag in the pit reaches 0.3 m, the control isolation baffle of the slag discharge outlet is opened again, and the opening degree of the control isolation baffles of the slag inlet and slag discharge outlet is controlled so that the depth of the liquid high-temperature slag in the pit is between 0.3-0.5 m, and the depth of the high-temperature slag is prevented from being higher than the height of the slag inlet. When the temperature inside the pit is detected to rise to 200℃, the control valve of the hot coal injection inlet pipe is opened first, and then the control valve of the hot coal injection outlet pipe is opened. At this time, some coal powder enters the coal powder preheater for preheating and temperature rise. When the temperature of the hot coal injection outlet pipe is detected to rise to 100℃ and remain stable, the valve of the original coal injection pipe is closed. All coal powder enters the coal powder preheater for preheating and temperature rise before entering the blast furnace coal injection distributor. When the blast furnace operation does not require preheating of pulverized coal: open the valve of the original pulverized coal injection pipeline, and then close the control valve of the hot pulverized coal injection inlet pipeline, so that all pulverized coal can be transported along the original pulverized coal injection pipeline.

[0013] In one embodiment, when the control isolation baffle corresponding to the slag flow inlet of the high-temperature slag storage pit is opened, the slag flow rate entering the high-temperature slag storage pit is controlled to be 20-50% of the total slag flow rate.

[0014] In one embodiment, the hot gas vent of the heat reflector is closed during the storage of high-temperature slag.

[0015] In one embodiment, when the temperature inside the pit reaches or exceeds a preset temperature value, the inflow rate of high-temperature slag is reduced, and at the same time, the hot gas vent is opened to release the heat inside the pit. When the temperature inside the pit drops below the preset temperature value, the hot gas vent is closed again, and the inflow rate of high-temperature slag is adjusted.

[0016] In summary, the present invention has the following beneficial effects: This invention achieves preheating of pulverized coal through a pulverized coal preheating system. It operates in parallel with the existing pulverized coal injection system and can be switched. It can be put into use according to actual production conditions. The system has a simple structure and high flexibility, enabling the pulverized coal preheating temperature to reach above 200℃, effectively solving the problem of excessively low pulverized coal preheating temperature. Attached Figure Description

[0017] Figure 1This is a schematic diagram of the pulverized coal preheating system of the present invention.

[0018] In the diagram: 1. High-temperature slag storage pit; 2. Heat reflector baffle; 3. Connecting slag ditch; 4. Blast furnace slag ditch; 5. Iron molten ditch; 6. Hot gas exhaust hole; 7. Pulverized coal preheater; 8. Hot coal injection inlet pipe; 9. Hot coal injection outlet pipe; 10. Original coal injection pipe; 11. Blast furnace coal injection distributor; 12. Slag treatment system. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] It is worth noting that the directional terms such as "up" and "down" used in this article are all relative to the perspective of the attached figures and are only for the purpose of description. They should not be interpreted as limitations on the technical solutions.

[0021] like Figure 1 As shown, this invention proposes a pulverized coal preheating system, including a high-temperature slag storage device and a pulverized coal preheating device. The pulverized coal preheating device is installed inside the high-temperature slag storage device, which stores high-temperature slag. The heat of the slag is used to preheat the pulverized coal, as detailed below: The high-temperature slag storage device includes a high-temperature slag storage pit 1 and a heat-reflective baffle 2. The heat-reflective baffle 2 covers the opening of the high-temperature slag storage pit 1 to prevent heat loss. A slag inlet is provided on the side of the high-temperature slag storage pit 1, and a slag outlet is provided on the bottom. The slag inlet on the side is connected to the blast furnace slag trough 4 through a connecting slag ditch 3, and the slag outlet on the bottom is connected to the slag treatment system 12 through a discharge ditch. Both the slag inlet and the slag outlet are equipped with control isolation baffles.

[0022] The pulverized coal preheating device includes a pulverized coal preheater 7, a hot-feed pulverized coal injection inlet pipe 8, and a hot-feed pulverized coal injection outlet pipe 9. The pulverized coal preheating device is located in the blast furnace slag storage pit and below the heat reflector baffle 2. The entire pulverized coal preheating device is located above the slag inlet. One end of the hot-feed pulverized coal injection inlet pipe 8 is connected to the original pulverized coal injection pipe 10, and the other end of the hot-feed pulverized coal injection inlet pipe 8 passes through the high-temperature slag storage pit 1 and is connected to the pulverized coal preheater 7. One end of the hot-feed pulverized coal injection outlet pipe 9 is connected to the blast furnace pulverized coal injection distributor 11, and the other end of the hot-feed pulverized coal injection outlet pipe passes through the high-temperature slag storage pit 1 and is connected to the pulverized coal preheater 7. Both the hot-feed pulverized coal injection inlet pipe 8 and the hot-feed pulverized coal injection outlet pipe 9 are equipped with control valves and check valves.

[0023] like Figure 1As shown, under normal circumstances, one end of the blast furnace slag trough 4 is connected to the blast furnace taphole, and the other end is connected to the slag treatment system 12. An automatic baffle is installed at the connection point between the blast furnace slag trough 4 and the slag treatment system 12. A molten iron trough 5 is installed at the connection point between the blast furnace slag trough 4 and the blast furnace taphole, leading to the molten iron ladle. After slag discharge, molten iron flows into the molten iron ladle along the molten iron trough 5. This invention connects with the existing blast furnace slag trough 4, introducing the high-temperature slag discharged from the blast furnace into the high-temperature slag storage pit 1 through the connecting slag trough 3. Subsequently, the slag is discharged into the slag treatment system 12. The heat reflector absorbs the strong light from the high-temperature slag and reflects the heat onto the upper surface of the pulverized coal preheater 7, heating the upper part of the pulverized coal preheater 7. It is easy to understand that by controlling the opening and closing of the isolation baffles at the slag inlet and outlet, the flow of slag into the pit or the discharge of slag from the pit can be controlled.

[0024] In this invention, the high-temperature slag storage pit 1 has a cylindrical internal structure. The depth of the high-temperature slag storage pit 1 is controlled at 1.5-2 m, and the diameter is controlled at 1-1.2 m. Since the purpose of setting up the high-temperature slag storage pit 1 is to utilize the heat of the slag rather than to store slag, the high-temperature slag storage pit 1 should not be too large. The outer wall of the high-temperature slag storage pit 1 is constructed of high-temperature resistant heat-insulating bricks, and both the inner and outer walls are sprayed with a heat-insulating coating. Preferably, the height of the slag inlet from the bottom of the pit is 0.5-0.6 m.

[0025] As the coal powder preheater 7 in the pit is used for a long time, when the coal powder preheater 7 is worn out and needs to be replaced, it can be easily replaced by opening the heat reflector.

[0026] Preferably, the pulverized coal preheating system further includes a first temperature thermocouple and a second temperature thermocouple, i.e., temperature sensors. The first temperature thermocouple is installed on the inner wall of the high-temperature slag storage pit 1 to detect the temperature inside the high-temperature slag storage pit 1. The second temperature thermocouple is installed in the hot-powdered coal injection outlet pipe 9 to detect the temperature of the discharged pulverized coal. More preferably, the temperature thermocouples are at the same height as the slag inlet. The temperature thermocouples monitor the temperature changes inside the pit in real time, control the flow rate of liquid high-temperature slag flowing into the pit based on the temperature changes, and control the flow rate of pulverized coal entering the pulverized coal preheater 7 according to the temperature changes. For example, when the temperature inside the pit rises to 200°C, the opening of the hot-powdered coal injection inlet pipe 8 is controlled, allowing some pulverized coal to enter the pulverized coal preheater 7 first. When the temperature of the hot-powdered coal injection outlet pipe 9 is detected to reach 100°C, the valve of the original coal injection pipe 10 is closed, and the opening of the hot-powdered coal injection inlet pipe 8 is controlled, allowing all the pulverized coal to enter the pulverized coal preheater 7 for preheating.

[0027] Preferably, the heat reflector baffle 2 is provided with one or more hot gas vent holes 6, and the hot gas vent holes 6 are equipped with valves. When the temperature inside the high-temperature slag storage pit 1 is too high, the hot gas is discharged by opening the hot gas vent holes 6 to reduce the temperature inside the pit. When the temperature inside the pit drops to a predetermined range, the hot gas vent holes 6 are closed.

[0028] like Figure 1 As shown, the original pulverized coal injection pipe 10 and blast furnace pulverized coal distributor 11 are equipment in the existing process. Based on this invention, a pulverized coal preheating device is added to introduce part of the pulverized coal into the pulverized coal preheater 7. After heat exchange, the temperature of the pulverized coal reaches more than 200°C.

[0029] Preferably, in the high-temperature slag storage pit 1, the hot-powder injection inlet pipe 8 and the hot-powder injection outlet pipe 9 are both located above the slag inlet. More preferably, the height difference between the hot-powder injection inlet pipe 8 / hot-powder injection outlet pipe 9 and the slag inlet is 0.5-1 m.

[0030] In this invention, the pulverized coal preheater 7 is made of stainless steel with a thickness of 5-8 mm to facilitate heat exchange. Its bottom surface is curved to increase the heat exchange area of ​​pulverized coal. Preferably, the length of the pulverized coal preheater 7 is 0.5-0.8 m and the depth is 0.3-0.5 m.

[0031] Blast furnaces typically discharge slag and iron through multiple taps. The pulverized coal preheating system can be connected to the blast furnace slag trough 4 at any one or more taps to achieve continuous preheating of pulverized coal.

[0032] Based on the above-mentioned pulverized coal preheating system, this invention also proposes a blast furnace pulverized coal injection heat delivery process based on the utilization of sensible heat from slag, as follows: When blast furnace operation requires preheating of pulverized coal: During the blast furnace slag and iron tapping process, liquid slag flows from blast furnace slag ditch 4 into slag treatment system 12. After the high-temperature liquid slag has been flowing into slag treatment system 12 for 5-10 minutes and the slag flow rate and temperature are qualified, the control isolation baffle corresponding to the slag inlet of the high-temperature slag storage pit 1 is opened. At the same time, the control isolation baffle of the slag outlet is opened to confirm that the slag in the pit can be discharged normally. Then the control isolation baffle of the slag outlet is closed, and the high-temperature slag storage pit 1 begins to store high-temperature slag. When the depth of the high-temperature slag in the pit reaches 0.3 m, the control isolation baffle of the slag discharge outlet is opened again, and the opening degree of the control isolation baffles of the slag inlet and slag discharge outlet is controlled so that the depth of the liquid high-temperature slag in the pit is between 0.3-0.5 m, and the depth of the high-temperature slag is prevented from being higher than the height of the slag inlet. When the temperature inside the pit is detected to rise to 200℃, the control valve of the hot coal injection inlet pipe 8 is opened first, and then the control valve of the hot coal injection outlet pipe 9 is opened. At this time, some coal powder enters the coal powder preheater 7 for preheating and temperature rise. When the temperature of the hot coal injection outlet pipe 9 is detected to rise to 100℃ and remain stable, the valve of the original coal injection pipe 10 is closed. All coal powder enters the coal powder preheater 7 for preheating and temperature rise before entering the blast furnace coal injection distributor 11. When the blast furnace operation does not require preheating of pulverized coal: open the valve of the original pulverized coal injection pipe 10, and then close the control valve of the hot pulverized coal injection inlet pipe 8. All pulverized coal is then transported along the original pulverized coal injection pipe 10. The high-temperature slag in the pit can maintain its original inflow and outflow settings, keeping the pit temperature within the set range, allowing it to be put into use at any time. Alternatively, all the high-temperature slag in the pit can be discharged, and the inflow of high-temperature slag can be stopped.

[0033] When the control isolation baffle corresponding to the slag flow inlet of the high-temperature slag storage pit 1 is opened, the slag flow rate entering the high-temperature slag storage pit 1 is controlled to be 20-50% of the total slag flow rate.

[0034] During the storage of high-temperature slag, the hot air vent 6 of the heat reflector plate is closed. When the temperature inside the pit reaches or exceeds the preset temperature value, the inflow rate of high-temperature slag is reduced, and at the same time, the hot air vent 6 is opened to release the heat from the pit. Once the temperature inside the pit drops below the preset temperature value, the hot air vent 6 is closed again, and the inflow rate of high-temperature slag is adjusted. Preferably, the preset temperature value can be 400°C. This invention controls the temperature inside the pit to be maintained between 350-400°C. When the temperature inside the pit is less than 350°C, the temperature inside the pit is increased by increasing the inflow rate of high-temperature slag.

[0035] If it is necessary to further increase the temperature of pulverized coal, the preset temperature value in the pit can be increased to 500℃. When the temperature in the pit is between 400-500℃, the temperature of the hot coal injection pipe 9 should be monitored in real time and controlled to not exceed 300℃.

[0036] If the amount of coal injected during production is small, the temperature inside the pit should be controlled to be close to 350℃. As the amount of coal injected increases, the temperature inside the pit should be increased accordingly.

[0037] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A pulverized coal preheating system, characterized in that, This includes high-temperature slag storage devices and pulverized coal preheating devices; The high-temperature slag storage device includes a high-temperature slag storage pit (1) and a heat reflective baffle (2). The heat reflective baffle (2) covers the opening of the high-temperature slag storage pit (1). A slag inlet is provided on the side of the high-temperature slag storage pit (1), and a slag outlet is provided on the bottom. The slag inlet on the side is connected to the blast furnace slag ditch (4) through a connecting slag ditch (3), and the slag outlet on the bottom is connected to the slag treatment system (12) through a discharge ditch. Both the slag inlet and the slag outlet are equipped with control isolation baffles. The pulverized coal preheating device includes a pulverized coal preheater (7), a hot-feed pulverized coal injection inlet pipe (8), and a hot-feed pulverized coal injection outlet pipe (9). The pulverized coal preheating device is located in the blast furnace slag storage pit and below the heat reflector baffle (2). The pulverized coal preheating device is located above the slag inlet. One end of the hot-feed pulverized coal injection inlet pipe (8) is connected to the original pulverized coal injection pipe (10), and the other end of the hot-feed pulverized coal injection inlet pipe (8) passes through the high-temperature slag storage pit (1) and is connected to the pulverized coal preheater (7). One end of the hot-feed pulverized coal injection outlet pipe (9) is connected to the blast furnace pulverized coal distributor (11), and the other end of the hot-feed pulverized coal injection outlet pipe passes through the high-temperature slag storage pit (1) and is connected to the pulverized coal preheater (7). Both the hot-feed pulverized coal injection inlet pipe (8) and the hot-feed pulverized coal injection outlet pipe (9) are equipped with control valves and check valves.

2. The pulverized coal preheating system as described in claim 1, characterized in that, The heat reflective baffle (2) is provided with one or more hot gas discharge holes (6), and the hot gas discharge holes (6) are equipped with valves.

3. The pulverized coal preheating system as described in claim 2, characterized in that, It also includes a first temperature thermocouple and a second temperature thermocouple. The first temperature thermocouple is installed on the inner wall of the high-temperature slag storage pit (1) to detect the temperature inside the high-temperature slag storage pit (1). The second temperature thermocouple is installed in the hot coal injection outlet pipe (9) to detect the temperature of the discharged coal powder.

4. The pulverized coal preheating system as described in claim 3, characterized in that, The temperature thermocouple is at the same height as the slag inlet.

5. The pulverized coal preheating system as described in claim 2, characterized in that, Inside the high-temperature slag storage pit (1), the hot-powder injection inlet pipe (8) and the hot-powder injection outlet pipe (9) are both located above the slag inlet, and the height difference between the hot-powder injection inlet pipe (8) / hot-powder injection outlet pipe (9) and the slag inlet is 0.5-1 m.

6. The pulverized coal preheating system as described in claim 2, characterized in that, The interior of the high-temperature slag storage pit (1) is a cylindrical structure. The depth of the high-temperature slag storage pit (1) is 1.5-2 m and the diameter is 1-1.2 m.

7. A blast furnace pulverized coal injection heat delivery process based on the utilization of sensible heat from slag, characterized in that, This is achieved through the pulverized coal preheating system described in claim 2, as follows: When blast furnace operation requires preheating of pulverized coal: During the blast furnace slag and iron tapping process, liquid slag flows from the blast furnace slag ditch (4) into the slag treatment system (12). After the high-temperature liquid slag flows into the slag treatment system (12) for 5-10 minutes and the slag flow rate and temperature are qualified, the control isolation baffle corresponding to the slag inlet of the high-temperature slag storage pit (1) is opened. At the same time, the control isolation baffle of the slag outlet is opened to confirm that the slag in the pit can be discharged normally. Then the control isolation baffle of the slag outlet is closed, and the high-temperature slag storage pit (1) begins to store high-temperature slag. When the depth of the high-temperature slag in the pit reaches 0.3 m, the control isolation baffle of the slag discharge outlet is opened again, and the opening degree of the control isolation baffles of the slag inlet and slag discharge outlet is controlled so that the depth of the liquid high-temperature slag in the pit is between 0.3-0.5 m, and the depth of the high-temperature slag is prevented from being higher than the height of the slag inlet. When the temperature inside the pit is detected to rise to 200℃, the control valve of the hot coal injection inlet pipe (8) is opened first, and then the control valve of the hot coal injection outlet pipe (9) is opened. At this time, some coal powder enters the coal powder preheater (7) for preheating and temperature rise. When the temperature of the hot coal injection outlet pipe (9) is detected to rise to 100℃ and remain stable, the valve of the original coal injection pipe (10) is closed. All coal powder enters the coal powder preheater (7) for preheating and temperature rise before entering the blast furnace coal injection distributor (11). When the blast furnace operation does not require preheating of pulverized coal: open the valve of the original pulverized coal injection pipe (10), and then close the control valve of the hot pulverized coal injection inlet pipe (8), and all pulverized coal is transported along the original pulverized coal injection pipe (10).

8. The blast furnace pulverized coal injection heat delivery system based on the utilization of sensible heat of slag as described in claim 7, characterized in that, When the control isolation baffle corresponding to the slag inlet of the high-temperature slag storage pit (1) is opened, the slag flow rate entering the high-temperature slag storage pit (1) is controlled to be 20-50% of the total slag flow rate.

9. The blast furnace pulverized coal injection heat delivery system based on the utilization of sensible heat of slag as described in claim 7, characterized in that, During the storage of high-temperature slag, the hot gas exhaust hole (6) of the heat reflector is closed.

10. The blast furnace pulverized coal injection heat delivery system based on the utilization of sensible heat of slag as described in claim 7, characterized in that, When the temperature inside the pit reaches or exceeds the preset temperature value, the inflow of high-temperature slag is reduced, and at the same time, the hot gas discharge hole (6) is opened to discharge the heat inside the pit. When the temperature inside the pit drops below the preset temperature value, the hot gas discharge hole (6) is closed again, and the inflow of high-temperature slag is adjusted.

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