Hot blast furnace flue gas purification system and control method

Abstract

An embodiment of the present invention discloses a hot blast furnace flue gas purification system and control method. The hot blast furnace flue gas purification system includes at least one hot blast furnace; a flue main pipe connected to the hot blast furnace at its head end, the flue main pipe being provided with a damper door and a chimney, the damper door being disposed between the hot blast furnace and the chimney; a purification pipeline connected to the hot blast furnace at its head end, the purification pipeline being provided with a flue gas purification device; a flue gas induced draft fan connected to the end of the purification pipeline; the flue gas induced draft fan also being connected to the chimney; the hot blast furnace flue gas purification system also includes a control device and a first pressure detection device, the first pressure detection device being disposed in the purification pipeline and between the flue gas purification device and the flue gas induced draft fan, the control device being configured to fully open the damper door when the pressure detected by the first pressure detection device is greater than a first preset pressure. The present invention can promptly discharge the hot blast furnace flue gas, avoid accidents in the flue main pipe, and ensure the safe operation of the system.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of hot blast furnace flue gas purification, and in particular to a hot blast furnace flue gas purification system and a control method. Background Art

[0002] In the original hot blast furnace process, the flue gas is directly discharged into the chimney through the flue main pipe after the waste heat is recovered. However, when the flue gas purification device is incorporated, the original hot blast furnace exhaust gas discharge process and channel are changed. Once the flue gas purification device or the flue gas induced draft fan is shut down in an emergency, a huge amount of flue gas (≥100,000m 3 / h) is blocked, which will cause the exhaust gas from the hot blast furnace to have no channel to be discharged, resulting in pressure buildup and flue gas backflow, which may lead to serious accidents such as explosions in the hot blast furnace and flue main pipe, which is not conducive to the safe operation of the system. Summary of the Invention

[0003] The present invention provides a hot blast furnace flue gas purification system and a control method, which can discharge the flue gas of the hot blast furnace in time, avoid serious accidents such as explosion in the flue main pipe, and ensure the safe operation of the hot blast furnace flue gas purification system.

[0004] According to one aspect of the present invention, a hot blast furnace flue gas purification system is provided, the system comprising:

[0005] at least one hot air stove;

[0006] a flue main pipe connected to the hot blast stove at its head end, the flue main pipe being provided with a damper door and a chimney, the damper door being provided between the hot blast stove and the chimney;

[0007] A purification pipeline connected to the hot blast furnace at its head end, wherein a flue gas purification device is provided in the purification pipeline;

[0008] A flue gas induced draft fan, the flue gas induced draft fan is connected to the end of the purification pipeline; the flue gas induced draft fan is also connected to the chimney;

[0009] The hot blast furnace flue gas purification system also includes a control device and a first pressure detection device. The first pressure detection device is arranged in the purification pipeline and is arranged between the flue gas purification device and the flue gas induced draft fan. The control device is used to control the baffle door to fully open when the pressure detected by the first pressure detection device is greater than a first preset pressure.

[0010] Optionally, the hot blast furnace flue gas purification system further includes a coal-injection pulverized gas pipeline, the head end of which is connected to the flue gas induced draft fan; a coal-injection pulverized gas intake valve and a coal-injection pulverized gas device are provided in the coal-injection pulverized gas pipeline, and the coal-injection pulverized gas intake valve is provided between the head end of the coal-injection pulverized gas pipeline and the coal-injection pulverized gas device;

[0011] The control device is further configured to control the coal pulverizing injection gas intake valve to close when the pressure detected by the first pressure detection device is greater than a first preset pressure.

[0012] Optionally, the hot blast stove flue gas purification system further includes a second pressure detection device, which is arranged in the flue main pipe and between the hot blast stove and the damper door. The control device is used to control the damper door to fully open when the pressure detected by the second pressure detection device is greater than a second preset pressure.

[0013] Optionally, the control device includes a control module and a baffle door driving module, and the control module is specifically used to send a full-open action instruction to the baffle door driving module to control the baffle door to fully open when the pressure detected by the second pressure detection device is greater than a second preset pressure.

[0014] Optionally, the hot blast stove flue gas purification system includes at least two hot blast stoves, and the control device is further configured to, when the pressure detected by the second pressure detection device is greater than a second preset pressure, send a full-open action instruction to the damper door driving module for a first preset time period, and then, if the pressure detected by the second pressure detection device is greater than a third preset pressure, control at least one hot blast stove to enter a stewing state;

[0015] and after sending a full-open action instruction to the baffle door driving module for a second preset time, if the pressure detected by the second pressure detection device is greater than a fourth preset pressure, controlling at least two of the hot blast furnaces to enter a stewing state;

[0016] The second preset time length is greater than the first preset time length, and the fourth preset pressure is less than the third preset pressure.

[0017] Optionally, the hot blast furnace flue gas purification system further includes a flue gas purification device inlet valve and a flue gas purification device outlet valve; the flue gas purification device inlet valve is arranged between the second pressure detection device and the flue gas purification device, and the flue gas purification device outlet valve is arranged between the flue gas purification device and the first pressure detection device;

[0018] The control device is also used to control the inlet valve of the flue gas purification device to close and the outlet valve of the flue gas purification device to close after confirming that the damper door is fully open.

[0019] Optionally, the hot blast stove flue gas purification system further comprises a coal-injection pulverizing bypass flue gas pipeline, the head end of the coal-injection pulverizing bypass flue gas pipeline being connected to the flue main pipe before the damper door, and the tail end of the coal-injection pulverizing bypass flue gas pipeline being connected to the coal-injection pulverizing device;

[0020] The coal-injection pulverizing bypass flue gas pipeline is provided with a coal-injection pulverizing bypass flue gas intake valve, and the coal-injection pulverizing bypass flue gas intake valve is provided before the coal-injection pulverizing device;

[0021] The control device is also used to confirm that after the damper door is fully opened, if it is detected that the flue gas draft fan and the flue gas purification device have not returned to normal within a third preset time period, then control the coal pulverizing bypass flue gas intake valve to open, and adjust the opening of the damper door to meet the coal pulverizing flue gas volume demand.

[0022] Optionally, the hot blast furnace flue gas purification system also includes a waste heat recovery pipeline, in which a waste heat recovery device is provided. The head end of the waste heat recovery pipeline is connected to the hot blast furnace, and the end of the waste heat recovery pipeline is connected to the flue main pipe, and the connection position is located before the baffle door.

[0023] According to another aspect of the present invention, a control method for a hot blast stove flue gas purification system is provided. The method includes: when the pressure detected by a first pressure detection device is greater than a first preset pressure, controlling the damper door to fully open.

[0024] Optionally, the control method of the hot blast stove flue gas purification system further includes: when the pressure detected by the second pressure detection device is greater than a second preset pressure, controlling the damper door to fully open.

[0025] The technical solution of this embodiment is to set a damper door in front of the chimney and a first pressure detection device between the flue gas purification device and the flue gas induced draft fan. When the flue gas purification device or the flue gas induced draft fan fails, when the pressure detected by the first pressure detection device is greater than the first preset pressure, the control device controls the damper door to be fully opened, so that the flue gas trapped in the flue main can be discharged in time, thereby solving the problem in the prior art that the flue gas discharged from the hot blast furnace has no channel to be discharged, resulting in pressure buildup, flue gas backflow, and malicious accidents such as explosion of the hot blast furnace and the flue main, preventing the backflow of hot blast furnace flue gas, and malicious accidents such as explosion of the hot blast furnace and the flue main, thereby ensuring the safe operation of the hot blast furnace flue gas purification system.

[0026] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 2 is a schematic structural diagram of a hot blast furnace flue gas purification system according to an embodiment of the present invention;

[0029] Figure 2 2 is a schematic structural diagram of another hot blast furnace flue gas purification system provided according to an embodiment of the present invention;

[0030] Figure 3 2 is a schematic structural diagram of another hot blast furnace flue gas purification system provided according to an embodiment of the present invention;

[0031] Figure 4 2 is a schematic structural diagram of another hot blast furnace flue gas purification system provided according to an embodiment of the present invention;

[0032] Figure 5 2 is a schematic structural diagram of another hot blast furnace flue gas purification system provided according to an embodiment of the present invention;

[0033] Figure 6 2 is a schematic structural diagram of another hot blast furnace flue gas purification system provided according to an embodiment of the present invention;

[0034] Figure 7 This is a flow chart of a control method for a hot blast furnace flue gas purification system according to an embodiment of the present invention;

[0035] Figure 8 This is a flow chart of another method for controlling a hot blast stove flue gas purification system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0037] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0038] Figure 1 This is a schematic diagram of the structure of a hot blast furnace flue gas purification system provided by an embodiment of the present invention, with reference to Figure 1 , an embodiment of the present invention provides a hot blast stove flue gas purification system, the system comprising: at least one hot blast stove 10; a flue main pipe 210 connected to the hot blast stove 10 at its head end, a damper door 20 and a chimney 30 being provided in the flue main pipe 210, the damper door 20 being provided between the hot blast stove 10 and the chimney 30; a purification pipeline 220 connected to the hot blast stove 10 at its head end, a flue gas purification device 40 being provided in the purification pipeline 220; a flue gas induced draft fan 50, the flue gas induced draft fan 50 being connected to the end of the purification pipeline 220; the flue gas induced draft fan 50 is also connected to the chimney 30; the hot blast stove flue gas purification system further comprises a control device 140 and a first pressure detection device 60, the first pressure detection device 60 being provided in the purification pipeline 220 and between the flue gas purification device 40 and the flue gas induced draft fan 50, the control device 140 being used to control the damper door 20 to fully open when the pressure detected by the first pressure detection device 60 is greater than a first preset pressure.

[0039] Specifically, the fuel of the hot blast furnace 10 is mostly solid fuel such as straw and coal, which is easy to produce a large amount of smoke and toxic gases such as nitrogen monoxide and sulfur dioxide after combustion. Direct discharge will seriously pollute the air and does not meet the environmental emission standards. Therefore, it is necessary to use a flue gas purification device 40 to purify the flue gas. The concentration of harmful gases in the treated flue gas meets environmental protection requirements and can be discharged. The flue gas induced draft fan 50 is connected to the chimney 30, and the flue gas induced draft fan 50 is used to transfer the flue gas purified by the flue gas purification device 40 to the chimney 30 and discharge it into the atmosphere. The flue gas purification device 40 or the flue gas induced draft fan 50 is prone to malfunction after long-term operation. When the flue gas purification device 40 or the flue gas induced draft fan 50 is shut down in an emergency, a huge amount of flue gas (≥100,000m 3 / h) cannot be delivered to the chimney 30 in time, causing the flue gas to flow back into the hot blast furnace 10, and the purification pipeline 220 and the flue main pipe 210 to be pressurized. The pressure value in the pipeline increases sharply and exceeds the normal pressure. When the control device 140 receives that the pressure detected by the first pressure detection device 60 is greater than the first preset pressure, the first preset pressure can be 5Kpa, the control device 140 immediately controls the damper door 20 to be fully opened, and a large amount of flue gas can be discharged through the chimney 30, reducing the pressure of the purification pipeline 220 and the flue main pipe 210, avoiding the purification pipeline 220 and the flue main pipe 210 from causing serious accidents such as explosion, and ensuring the safe operation of the hot blast furnace flue gas purification system.

[0040] It should be noted that the control device 140 can be a programmable logic controller (PLC), and the user can edit the corresponding program according to his or her needs to meet the requirements of automated production. The embodiment of the present invention does not limit the type of the control device 140.

[0041] The technical solution of this embodiment is to set a damper door in front of the chimney and a first pressure detection device between the flue gas purification device and the flue gas induced draft fan. When the flue gas purification device or the flue gas induced draft fan fails, when the pressure detected by the first pressure detection device is greater than the first preset pressure, the control device controls the damper door to be fully opened, so that the flue gas trapped in the purification pipeline and the flue main pipe can be discharged in time, thereby solving the problem in the prior art that the flue gas discharged from the hot blast furnace has no channel to be discharged, resulting in pressure buildup, flue gas backflow, and malicious accidents such as explosion of the hot blast furnace, purification pipeline and flue main pipe, etc., and preventing the occurrence of malicious accidents such as explosion of the hot blast furnace, purification pipeline and flue main pipe and so on, thereby ensuring the safe operation of the hot blast furnace flue gas purification system.

[0042] Figure 2 This is a structural diagram of another hot blast furnace flue gas purification system provided according to an embodiment of the present invention, with reference to Figure 2 Optionally, the hot blast furnace flue gas purification system also includes a coal-injection pulverizing flue gas pipeline 230, the head end of the coal-injection pulverizing flue gas pipeline 230 is connected to the flue gas induced draft fan 50; a coal-injection pulverizing air intake valve 70 and a coal-injection pulverizing device 80 are provided in the coal-injection pulverizing flue gas pipeline 230, and the coal-injection pulverizing air intake valve 70 is provided between the head end of the coal-injection pulverizing flue gas pipeline 230 and the coal-injection pulverizing device 80; the control device 140 is also used to control the coal-injection pulverizing air intake valve 70 to close when the pressure detected by the first pressure detection device 60 is greater than the first preset pressure.

[0043] Specifically, the coal-injection pulverizing device 80 is connected to the flue gas induced draft fan 50 via the coal-injection pulverizing air intake valve 70. The coal-injection pulverizing device 80 utilizes the flue gas extracted by the flue gas induced draft fan 50 to safely process the raw coal into pulverized coal that meets the requirements for coal injection. When the pressure detected by the first pressure detection device 60 exceeds a first preset pressure, the control device 140 controls the coal-injection pulverizing air intake valve 70 to close, preventing further gas from entering the coal-injection pulverizing device 80. At this point, the hot blast furnace 10, the flue gas purification device 40, and the coal-injection pulverizing device 80 are isolated from each other and operate in a self-circulating manner.

[0044] Figure 3 This is a structural diagram of another hot blast furnace flue gas purification system provided according to an embodiment of the present invention, with reference to Figure 3 Optionally, the hot blast stove flue gas purification system also includes a second pressure detection device 90, which is arranged in the flue main pipe 210 and between the hot blast stove 10 and the damper door 20. The control device 140 is used to control the damper door 20 to fully open when the pressure detected by the second pressure detection device 90 is greater than the second preset pressure.

[0045] Specifically, when the flue gas purification device 40 experiences an emergency shutdown or other failure, a large amount of flue gas cannot be purified in time and is discharged into the atmosphere through the flue gas induced draft fan 50 and the chimney 30, resulting in a huge amount of flue gas (≥100,000m 3 / h) flows back into the hot blast stove 10, the flue main pipe 210 is pressurized, and the pressure value in the pipe increases sharply and exceeds the normal pressure. When the control device 140 receives the pressure detected by the second pressure detection device 90 that is greater than the second preset pressure, the second preset pressure can be 5KPa, the control device 140 immediately controls the damper door 20 to fully open, and a large amount of flue gas can be discharged through the chimney 30, reducing the pressure of the flue main pipe 210, and avoiding serious accidents such as explosion in the flue main pipe 210.

[0046] Continue to refer Figure 3 Optionally, the control device 140 includes a control module and a baffle door drive module. The control module is specifically used to send a full-open action instruction to the baffle door drive module to control the baffle door 20 to fully open when the pressure detected by the second pressure detection device 90 is greater than the second preset pressure.

[0047] Specifically, when the control module receives a pressure detected by the second pressure detection device 90 that is greater than the second preset pressure, which may be 5Kpa, the control module sends a full-open action instruction to the baffle door drive module. After receiving the full-open action instruction, the baffle door drive module controls the baffle door 20 to fully open.

[0048] Continue to refer Figure 3Optionally, the hot blast stove flue gas purification system includes at least two hot blast stoves 10, and the control device 140 is further used to control at least one hot blast stove 10 to enter the stewing state after the pressure detected by the second pressure detection device 90 is greater than the second preset pressure, after the first preset time period of sending a full-open action instruction to the baffle door driving module, if the pressure detected by the second pressure detection device 90 is greater than the third preset pressure; and control at least two hot blast stoves 10 to enter the stewing state after the second preset time period of sending a full-open action instruction to the baffle door driving module, if the pressure detected by the second pressure detection device 90 is greater than the fourth preset pressure; wherein the second preset time period is greater than the first preset time period, and the fourth preset pressure is less than the third preset pressure.

[0049] Specifically, to ensure a continuous supply of gas, the hot blast furnace 10 can be supplied by a first hot blast furnace and a second hot blast furnace operating in parallel. The first preset duration can be 5 to 8 seconds, and the second preset duration can be 20 to 30 seconds. The third and fourth preset pressures can be set according to actual needs and are not limited in this embodiment of the present invention.

[0050] When the pressure detected by the second pressure detection device 90 exceeds the second preset pressure, the control device 140 sends a full-opening command to the damper door drive module. If the damper door 20 does not fully open 5-8 seconds after the damper door drive module receives the full-opening command, this could be due to a fault in the damper door drive module, for example. If the pressure detected by the second pressure detection device 90 exceeds the third preset pressure, to ensure safe operation of the hot blast furnace 10 and prevent pressure buildup, the first hot blast furnace is automatically controlled to enter the simmering state, while the second hot blast furnace operates normally in the air supply state. At this point, the amount of flue gas entering the flue main 210 is half of its normal level. 20-30 seconds after the full-opening command is sent to the damper door drive module, to ensure safe operation of the hot blast furnace 10, air supply to the hot blast furnace 10 needs to be stopped. If the pressure detected by the second pressure detection device 90 exceeds the fourth preset pressure, the first hot blast furnace is controlled to enter the simmering state, while the second hot blast furnace is controlled to enter the simmering state. The hot blast furnace 10 is completely shut down, and the flue main 210 does not increase flue gas generation.

[0051] Figure 4 This is a structural diagram of another hot blast furnace flue gas purification system provided according to an embodiment of the present invention, with reference to Figure 4Optionally, the hot blast furnace flue gas purification system further includes a flue gas purification device inlet valve 100 and a flue gas purification device outlet valve 110; the flue gas purification device inlet valve 100 is arranged between the second pressure detection device 90 and the flue gas purification device 40, and the flue gas purification device outlet valve 110 is arranged between the flue gas purification device 40 and the first pressure detection device 60; the control device 140 is also used to control the flue gas purification device inlet valve 100 to close and the flue gas purification device outlet valve 110 to close after confirming that the baffle door 20 is fully open.

[0052] Specifically, after the control device 140 confirms that the damper door 20 is fully open, the hot blast furnace 10 resumes normal combustion, the flue gas purification device 40 enters a closed loop state, and the flue gas purification device inlet valve 100 and the flue gas purification device outlet valve 110 are closed.

[0053] Figure 5 This is a structural diagram of another hot blast furnace flue gas purification system provided according to an embodiment of the present invention, with reference to Figure 5 Optionally, the hot blast furnace flue gas purification system further includes a coal-injection pulverizing bypass flue gas pipeline 240, the head end of the coal-injection pulverizing bypass flue gas pipeline 240 is connected to the flue main 210 before the damper door 20, and the end of the coal-injection pulverizing bypass flue gas pipeline 240 is connected to the coal-injection pulverizing device 80; a coal-injection pulverizing bypass flue gas intake valve 120 is provided in the coal-injection pulverizing bypass flue gas intake valve 120, and the coal-injection pulverizing bypass flue gas intake valve 120 is provided before the coal-injection pulverizing device 80; the control device 140 is also used to confirm that after the damper door 20 is fully opened, if it is detected that the flue gas draft fan 50 and the flue gas purification device 40 have not returned to normal within a third preset time period, then the coal-injection pulverizing bypass flue gas intake valve 120 is controlled to open, and the opening of the damper door 20 is adjusted to meet the coal-injection pulverizing flue gas volume demand.

[0054] Specifically, in order not to affect the normal production of coal-injection pulverizing, a backup guarantee channel, the coal-injection pulverizing bypass flue gas pipeline 240, is set. After the control device 140 confirms that the damper door 20 is fully open, it detects that the flue gas induced draft fan 50 and the flue gas purification device 40 have not returned to normal within the third preset time period, then the coal-injection pulverizing bypass flue gas intake valve 120 is opened, and then the opening of the damper door 20 is adjusted to meet the coal-injection pulverizing flue gas volume demand. If it is detected that the flue gas induced draft fan 50 and the flue gas purification device 40 have returned to normal within the third preset time period, the flue gas purification device 40 is put into operation as normal production. Among them, the third preset time period can be set as needed, and the embodiment of the present invention does not limit the specific time period.

[0055] Figure 6 This is a structural diagram of another hot blast furnace flue gas purification system provided according to an embodiment of the present invention, with reference to Figure 6Optionally, the hot blast furnace flue gas purification system also includes a waste heat recovery pipeline 250, in which a waste heat recovery device 130 is provided. The head end of the waste heat recovery pipeline 250 is connected to the hot blast furnace 10, and the end of the waste heat recovery pipeline 250 is connected to the flue main pipe 210, and the connection position is located before the baffle door 20.

[0056] Specifically, the flue gas from the hot blast furnace 10 is discharged at high altitude, and there is no dedicated process to recover the waste heat and gases contained in the flue gas, resulting in energy waste. The waste heat recovery device 130 is mainly used to replace the waste heat, thereby reducing heat loss and waste, achieving better energy saving effects.

[0057] Figure 7 This is a flow chart of a control method for a hot blast furnace flue gas purification system according to an embodiment of the present invention, with reference to Figure 7 The embodiment of the present invention further provides a control method for a hot blast furnace flue gas purification system, which specifically includes the following steps:

[0058] S310: When the pressure detected by the first pressure detection device is greater than a first preset pressure, the baffle door is controlled to fully open.

[0059] Combine Figure 1 Specifically, the flue gas purification device 40 or the flue gas induced draft fan 50 is prone to failure during long-term operation. When the flue gas purification device 40 or the flue gas induced draft fan 50 is shut down in an emergency, a huge amount of flue gas (≥100,000m 3 / h) cannot be sent into the chimney 30 in time, causing the flue gas to flow back into the hot blast furnace 10, and the purification pipeline 220 and the flue main pipe 210 to be pressurized. The pressure value in the pipeline increases sharply and exceeds the normal pressure. When the pressure detected by the first pressure detection device 60 is greater than the first preset pressure, the control device 140 sends a door-opening signal. The first preset pressure can be 5Kpa. After receiving the door-opening signal, the control device 140 immediately controls the damper door 20 to be fully opened. A large amount of flue gas can be discharged through the chimney 30, reducing the pressure of the purification pipeline 220 and the flue main pipe 210, avoiding the purification pipeline 220 and the flue main pipe 210 from causing serious accidents such as explosion, and ensuring the safe operation of the hot blast furnace flue gas purification system.

[0060] The control method of the hot blast furnace flue gas purification system provided in an embodiment of the present invention is used to control the hot blast furnace flue gas purification system provided in any embodiment of the present invention. Therefore, the control method of the hot blast furnace flue gas purification system provided in an embodiment of the present invention also has the beneficial effects described in the above embodiments, which will not be repeated here.

[0061] Figure 8 This is a flow chart of another method for controlling a hot blast furnace flue gas purification system according to an embodiment of the present invention, with reference to Figure 8 Optionally, the control method of the hot blast furnace flue gas purification system includes:

[0062] S410: When the pressure detected by the first pressure detection device is greater than a first preset pressure, the baffle door is controlled to fully open.

[0063] S420: When the pressure detected by the second pressure detection device is greater than the second preset pressure, the baffle door is controlled to fully open.

[0064] Combine Figure 3 Specifically, when the flue gas purification device 40 experiences an emergency shutdown or other failure, a large amount of flue gas cannot be purified in time and is discharged into the atmosphere through the flue gas induced draft fan 50 and the chimney 30, resulting in a huge amount of flue gas (≥100,000m 3 / h) flows back into the hot blast stove 10, the flue main pipe 210 is pressurized, and the pressure value in the pipe increases sharply and exceeds the normal pressure. When the pressure detected by the second pressure detection device 90 is greater than the second preset pressure, the control device 140 sends a door-opening signal. The second preset pressure can be 5Kpa. After receiving the door-opening signal, the control device 140 immediately controls the damper door 20 to fully open. A large amount of flue gas can be discharged through the chimney 30, reducing the pressure of the flue main pipe 210, and avoiding serious accidents such as explosions in the flue main pipe 210.

[0065] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A hot blast furnace flue gas purification system, characterized in that: include: at least one hot air stove; a flue main pipe connected to the hot blast stove at its head end, the flue main pipe being provided with a damper door and a chimney, the damper door being provided between the hot blast stove and the chimney; A purification pipeline connected to the hot blast furnace at its head end, wherein a flue gas purification device is provided in the purification pipeline; A flue gas induced draft fan, the flue gas induced draft fan is connected to the end of the purification pipeline; the flue gas induced draft fan is also connected to the chimney; The hot blast furnace flue gas purification system further includes a control device and a first pressure detection device, wherein the first pressure detection device is arranged in the purification pipeline and is arranged between the flue gas purification device and the flue gas induced draft fan, and the control device is used to control the damper door to fully open when the pressure detected by the first pressure detection device is greater than a first preset pressure; The invention also includes a coal pulverizing flue gas pipeline for coal injection, wherein the head end of the coal pulverizing flue gas pipeline is connected to the flue gas induced draft fan; a coal pulverizing gas intake valve and a coal pulverizing device are provided in the coal pulverizing flue gas pipeline, and the coal pulverizing gas intake valve is provided between the head end of the coal pulverizing flue gas pipeline and the coal pulverizing device; The control device is further configured to control the coal pulverizing injection gas intake valve to close when the pressure detected by the first pressure detection device is greater than a first preset pressure.

2. The system according to claim 1, wherein: It also includes a second pressure detection device, which is arranged in the flue main pipe and between the hot blast stove and the damper door. The control device is used to control the damper door to fully open when the pressure detected by the second pressure detection device is greater than a second preset pressure.

3. The system according to claim 2, characterized in that The control device includes a control module and a baffle door driving module. The control module is specifically used to send a full-open action instruction to the baffle door driving module to control the baffle door to fully open when the pressure detected by the second pressure detection device is greater than a second preset pressure.

4. The system according to claim 3, characterized in that The hot blast stove flue gas purification system includes at least two hot blast stoves, and the control device is further configured to, when the pressure detected by the second pressure detection device is greater than the second preset pressure, send a full-open action instruction to the damper door driving module for a first preset time period, and then, if the pressure detected by the second pressure detection device is greater than the third preset pressure, control at least one hot blast stove to enter a stewing state; and after sending a full-open action instruction to the baffle door driving module for a second preset time, if the pressure detected by the second pressure detection device is greater than a fourth preset pressure, controlling at least two of the hot blast furnaces to enter a stewing state; The second preset time length is greater than the first preset time length, and the fourth preset pressure is less than the third preset pressure.

5. The system according to claim 4, characterized in that It also includes a flue gas purification device inlet valve and a flue gas purification device outlet valve; the flue gas purification device inlet valve is arranged between the second pressure detection device and the flue gas purification device, and the flue gas purification device outlet valve is arranged between the flue gas purification device and the first pressure detection device; The control device is also used to control the inlet valve of the flue gas purification device to close and the outlet valve of the flue gas purification device to close after confirming that the damper door is fully open.

6. The system according to claim 5, characterized in that It also includes a coal pulverizing injection bypass flue gas pipeline, the head end of the coal pulverizing injection bypass flue gas pipeline is connected to the flue main pipe before the damper door, and the end of the coal pulverizing injection bypass flue gas pipeline is connected to the coal pulverizing injection device; The coal-injection pulverizing bypass flue gas pipeline is provided with a coal-injection pulverizing bypass flue gas intake valve, and the coal-injection pulverizing bypass flue gas intake valve is provided before the coal-injection pulverizing device; The control device is also used to confirm that after the damper door is fully opened, if it is detected that the flue gas draft fan and the flue gas purification device have not returned to normal within a third preset time period, then control the coal pulverizing bypass flue gas intake valve to open, and adjust the opening of the damper door to meet the coal pulverizing flue gas volume demand.

7. The system according to claim 1, wherein: It also includes a waste heat recovery pipeline, in which a waste heat recovery device is provided. The head end of the waste heat recovery pipeline is connected to the hot blast furnace, and the end of the waste heat recovery pipeline is connected to the flue main pipe, and the connection position is located before the baffle door.

8. A control method for a hot blast stove flue gas purification system, applied to the hot blast stove flue gas purification system according to any one of claims 1 to 7, characterized in that: include: When the pressure detected by the first pressure detection device is greater than the first preset pressure, the baffle door is controlled to be fully opened.

9. The control method according to claim 8, characterized in that: Also includes: When the pressure detected by the second pressure detection device is greater than the second preset pressure, the baffle door is controlled to be fully opened.

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