A combined flue soot blowing device and its usage method

Abstract

The present invention relates to a combined flue soot blowing device and a method for using the same, which includes a wind cap assembly and an automatic control assembly arranged at the flue. The wind cap assembly includes a disturbance wind cap group, a suspension wind cap group, and a boiling wind cap group. The wind cap nozzles of the disturbance wind cap, the suspension wind cap, and the boiling wind cap are all Archimedes spiral nozzles. The angle between the outlet of the wind cap nozzle of the disturbance wind cap and the horizontal plane is -55° to -5°. The angle between the outlet of the wind cap nozzle of the suspension wind cap and the horizontal plane is -8° to 8°. The angle between the outlet of the wind cap nozzle of the boiling wind cap and the horizontal plane is 15° to 65°. It also includes an automatic control assembly, which includes a PLC controller, a visible flue gas detection assembly, an electric valve group, a medium delivery pipeline 1#, and a medium tank. It has the advantages of reasonable structural design, stable and reliable operation, etc., ensuring that the accumulated ash in the flue is cleaned without dead angles throughout the process. Even in the case of reduced grinding efficiency of the coal mill and decreased performance of the burner, it can ensure the long-term safe and stable operation of the boiler, broadening the coal type adaptability.

Description

Technical Field

[0001] The present invention relates to the technical field of boiler equipment, and particularly relates to a combined flue soot blowing device and a using method thereof. Background Art

[0002] When a pulverized coal boiler operates, raw coal is ground into pulverized coal by a coal mill and is transported to a pulverized coal burner through a pulverized coal pipeline. When the pulverized coal leaves the burner, it burns in the furnace. Under the action of an induced draft fan, the flue gas flows from the furnace - the retort angle horizontal flue - the tail heating surface - the denitration system - the preheater - the dust collector - the low-temperature economizer - the desulfurization system - the chimney - and is discharged into the atmosphere. As the boiler operates continuously, the grinding efficiency of the grinding components of the coal mill decreases, the burner is worn and burned out, and the performance of the burner decreases. In addition, due to the shortage of coal and the complex and changeable coal used in the boiler unit, which often deviates greatly from the designed coal type, incomplete combustion of pulverized coal occurs, and the dust content in the flue gas increases. Ash accumulation problems are extremely likely to occur at the horizontal flue of the boiler retort angle, the horizontal flue at the denitration inlet, and the outlet of the low-temperature economizer. Especially at the horizontal flue of the boiler retort angle, coking and secondary combustion sometimes occur, resulting in the boiler being forced to stop for coke cleaning. The coal adaptability of the boiler is limited, and when the coal type changes greatly, the long-term safe and stable operation of the boiler cannot be guaranteed. The present invention is precisely proposed based on the above research background, aiming to provide a combined flue soot blowing device and a using method thereof to meet the actual design and use requirements. Summary of the Invention

[0003] Aiming at the above deficiencies of the flue soot blowing device in the prior art, the purpose of the present invention is to provide a combined flue soot blowing device and a using method thereof, which use a disturbance air cap group to make the dust float upward from the bottom of the flue, suspend above the air caps through a suspension air cap group, lift the dust to the middle of the flue through a boiling air cap group, and finally the dust is carried away by the flue gas. Because of its reasonable structural design, stable and reliable operation and other advantages, it can ensure that the ash in the flue is cleaned without dead angles throughout the process. Even when the grinding efficiency of the coal mill decreases and the performance of the burner drops, the long-term safe and stable operation of the boiler can be guaranteed, and the coal adaptability is broadened.

[0004] In order to achieve the above purpose, the present invention is realized by adopting the following technical solutions:

[0005] A combined flue soot blowing device is used for a pulverized coal boiler. The combined flue soot blowing device includes an air cap and an automatic control component.

[0006] The air cap includes a disturbance air cap, a suspension air cap, and a boiling air cap. The air caps are arranged in sequence from front to back along the axial direction of the flue.

[0007] Furthermore, the disturbing wind cap, the suspension wind cap, and the boiling wind cap all include a wind cap body, and the wind cap body includes a wind cap nozzle, and all the wind cap nozzles are Archimedes spiral nozzles; the included angle between the outlet of the wind cap nozzle of the disturbing wind cap and the horizontal plane is -55° to -5°, the included angle between the outlet of the wind cap nozzle of the suspension wind cap and the horizontal plane is -8° to 8°, and the included angle between the outlet of the wind cap nozzle of the boiling wind cap and the horizontal plane is 15° to 65°.

[0008] Furthermore, the wind cap body further includes an inner duct sealing box and an outer duct sealing box that are connected to each other. The inner duct sealing box and the outer duct sealing box are both filled with a heat-insulating layer, and each inner duct sealing box is also provided with a wind cap nozzle and a fixing support for fixing the wind cap nozzle.

[0009] Furthermore, the outer duct sealing box is also provided with a medium delivery pipeline 2# that penetrates through the outer duct sealing box and is connected to the wind cap nozzle. There are at least three and an odd number of the medium delivery pipelines 2# arranged in parallel.

[0010] Furthermore, multiple identical disturbing wind caps form a disturbing wind cap group, multiple identical suspension wind caps form a suspension wind cap group, and multiple identical boiling wind caps form a boiling wind cap group.

[0011] Furthermore, the wind cap group is arranged at the reheat furnace arch of the pulverized coal boiler. Inside the reheat furnace arch of the pulverized coal boiler, a platen reheater tube bank, a rear water wall suspension tube, and a final superheater tube bank are arranged in sequence. The wind caps are arranged between the platen reheater tube bank and the final superheater tube bank in the reheat furnace arch along the axial direction of the duct from front to back. When the wind caps are arranged along the axial direction of the duct, the distance between two adjacent wind caps is 600 - 1200 mm.

[0012] Furthermore, when the disturbing wind cap group, the suspension wind cap group, and the boiling wind cap group are arranged transversely along the duct, and when they are arranged above the tube wall of the rear water wall suspension tube, one wind cap is arranged every 4 - 12 water wall suspension tubes, and water wall anti-abrasion tiles are also arranged on the rear water wall suspension tube.

[0013] Furthermore, when the wind cap group is arranged transversely along the duct, the disturbing wind cap group includes disturbing wind caps arranged at equal intervals in the same axial direction, and the axial direction is perpendicular to the axial direction of the duct; the suspension wind cap group includes suspension wind caps arranged at equal intervals in the same axial direction, and the axial direction is perpendicular to the axial direction of the duct; the boiling wind cap group includes boiling wind caps arranged at equal intervals in the same axial direction, and the axial direction is perpendicular to the axial direction of the duct. And each suspension wind cap forms an alternating arrangement layout with the corresponding disturbing wind cap and boiling wind cap in the transverse direction of the duct.

[0014] Furthermore, the combined flue gas soot blowing device further includes an automatic control component, which includes a PLC controller, a visible flue gas detection component, an electric valve group, a medium conveying pipeline 1#, and a medium tank; the visible flue gas detection component and the electric valve group are both connected to the PLC controller, the electric valve group is arranged on the medium conveying pipeline 1#, one end of the medium conveying pipe is connected to the medium tank, and the other end is connected to a medium conveying pipeline 2# communicated with the wind cap nozzle; the visible flue gas detection component is arranged at the soot blower of the coal powder boiler's reheat angle for collecting the dust accumulation information at the flue in real time and sending the collected information to the PLC controller after data conversion, and the PLC controller controls the start and stop of the electric valve group according to the comparison result of the received dust accumulation information and the preset dust accumulation threshold value to control the working state of each wind cap.

[0015] As a further optimization of the above solution, the visible flue gas detection component adopts a video monitoring device; the medium tank stores compressed air or steam.

[0016] As a further optimization of the above solution, the automatic control component further includes a flow sensor and a pressure sensor arranged on the medium conveying pipeline 1#, the flow sensor and the pressure sensor are both connected to the PLC controller through data signals, and are used for collecting the pressure and flow information on the medium conveying pipeline 1# in real time and sending the real-time detected information to the PLC controller, and the PLC controller compares the received real-time pressure and flow information with the preset pressure threshold value and flow threshold value, and controls the start and stop of the electric valve group according to the comparison result.

[0017] The usage method of the above combined flue gas soot blowing device of the present invention includes the following steps:

[0018] 1) The flue gas enters the horizontal flue of the coal powder boiler and passes through the platen reheater, the water wall tube screen, and the final superheater in sequence. It is extremely easy for ash to accumulate and coke at the position near the water wall tube screen at the reheat angle flue. When the visible flue gas detection component detects ash accumulation in the flue and the ash accumulation reaches more than 30 mm, a signal is fed back to the PLC controller;

[0019] 2) The PLC controller sends a control instruction to the electric valve group, so that the medium enters the disturbance wind cap group, the suspension wind cap group, and the boiling wind cap group to work under the control of the PLC controller. The disturbance wind cap group makes the dust float upward from the bottom of the flue, passes through the suspension wind cap group and suspends above the wind cap, and the boiling wind cap group lifts the dust to the middle of the flue. Finally, the dust is carried away by the flue gas;

[0020] 3) The PLC controller issues a control instruction to the electric valve group again according to the dust thickness observed by the visible flue gas detection component. The default initial opening of the regulating valve is 20%. Each operation of the soot blower for 15 minutes is used as a feedback time interval point, and the visible flue gas detection component feeds back the dust thickness situation to the PLC controller. When the dust thickness is in an increasing state and the growth rate is within 50%, the opening of the electric valve group increases by 10%; if the growth rate is above 50%, the opening of the electric valve group increases by 15%. The PLC controller adjusts the opening of the electric valve group in real time according to the feedback of the visible flue gas detection component until the accumulated ash in the flue is adjusted to less than 30 mm;

[0021] 4) The pressure and flow signals in the 1# medium conveying pipeline are detected by the corresponding sensors and fed back to the PLC controller. The PLC controller issues a control instruction for the electric valve group according to the pressure difference between the left and right pipelines in the 1# medium conveying pipeline, so that the medium pressure and flow in the disturbance air cap group, suspension air cap group, and boiling air cap group are uniform. When the accumulated ash thickness reaches the preset value, the automatic control component can be put into the sleep state. When the situation in step 1) above appears again in the result detected by the visible flue gas detection component, the automatic control component is awakened again to the working state of controlling the electric valve group.

[0022] Adopting the combined flue soot blower and its using method of the present invention has the following beneficial effects:

[0023] The structure design is reasonable, the operation is stable and reliable, and it can ensure that the accumulated ash in the flue is cleaned without dead corners throughout the process. Even in the case of reduced grinding efficiency of the coal mill and decreased performance of the burner, it can ensure the long-term safe and stable operation of the boiler and broaden the coal type adaptability. Description of the Drawings

[0024] Appendix Figure 1 It is a schematic structural diagram of a combined flue soot blower of the present invention.

[0025] Appendix Figure 2 It is Figure 1 a schematic diagram of the front view at position K in

[0026] Appendix Figure 3 It is Figure 1 a cross-sectional view at position K in

[0027] Appendix Figure 4 It is Figure 3 a cross-sectional view at position E in

[0028] Appendix Figure 5 It is a schematic structural diagram of the disturbance air cap, suspension air cap, and boiling air cap of the present invention, where (a) is the disturbance air cap, (b) is the suspension air cap, and (c) is the boiling air.

[0029] AppendixFigure 6 This is a schematic diagram of the medium pipeline flow of the present invention.

[0030] Explanation of the markings in the figure: 1 - Reheat furnace duct with flame deflectors; 2 - Disturbing air cap group; 3 - Suspended air cap group; 4 - Boiling air cap group; 5 - Rear water wall suspension pipe; 6 - Water wall abrasion protection tile; 7 - Disturbing air cap; 8 - Suspended air cap; 9 - Boiling air cap; 10 - Inner sealing box of the air duct; 11 - Outer sealing box of the air duct; 12 - Thermal insulation layer; 13 - Air cap nozzle; 14 - Fixed support; 15 - Medium conveying pipeline 2# connected to the air duct nozzle; 16 - Electric valve group; 17 - Medium conveying pipeline 1#; 18 - Medium tank; 19 - Platen reheater tube bank; 20 - Final stage superheater tube bank Specific implementation mode

[0031] The following combines the attached Figures 1-6 A combined flue gas sootblowing device of the present invention and its usage method will be described in detail.

[0032] A combined flue gas sootblowing device, which is used for a pulverized coal boiler. The combined flue gas sootblowing device includes an air cap assembly and an automatic control assembly arranged at the reheat furnace duct with flame deflectors 1 of the pulverized coal boiler.

[0033] Inside the reheat furnace duct with flame deflectors 1 of the pulverized coal boiler, there are platen reheater tube bank 19, rear water wall suspension pipe 5, and final stage superheater tube bank 20. The rear water wall suspension pipe 5 is arranged between the platen reheater tube bank 19 and the final stage superheater tube bank 20.

[0034] The air cap assembly includes a disturbing air cap group 2, a suspended air cap group 3, and a boiling air cap group 4, and is arranged in sequence from front to back along the axial direction of the air duct between the platen reheater tube bank 19 and the final stage superheater tube bank 20 in the reheat furnace duct with flame deflectors 1. The distance between two adjacent air cap groups is 600 - 1200 mm.

[0035] When the air cap assembly is arranged along the transverse direction of the boiler, it is all arranged above the pipe wall of the rear water wall suspension pipe 5 of the reheat furnace duct with flame deflectors. The rear water wall suspension pipe 5 is also provided with a water wall abrasion protection tile 6. The disturbing air cap group 2 includes disturbing air caps 7 arranged at equal intervals in the same axial direction; the suspended air cap group 3 includes suspended air caps 8 arranged at equal intervals in the same axial direction; the boiling air cap group 4 includes boiling air caps 9 arranged at equal intervals in the same axial direction; in the above transverse arrangement of the air cap groups, the axial direction is perpendicular to the axial direction of the air duct; the interval value between each air cap of the disturbing air cap group 2, the suspended air cap group 3, and the boiling air cap group 4 is the same. One air cap is arranged every 4 - 12 rear water wall suspension pipes 5, and the suspended air caps 8 are arranged in a staggered layout with the corresponding disturbing air caps 7 and boiling air caps 9 in the transverse direction of the air duct.

[0036] The disturbance air cap 7, suspension air cap 8, and boiling air cap 9 all include an air cap body. The air cap body includes an inner duct sealing box 10 and an outer duct sealing box 11 that are connected to each other. The inner duct sealing box 10 and the outer duct sealing box 11 are both filled with a heat insulation layer 12. Each inner duct sealing box 10 is also provided with an air cap nozzle 13 and a fixing support 14 for fixing the air cap nozzle. The outer duct sealing box 11 is also provided with at least three and an odd number of medium conveying pipelines 2#15 that penetrate the outer duct sealing box 11 and are connected to the air cap nozzle 13. Among them, the middle medium conveying pipeline 2#15 conveys the medium into the air cap body and evenly conveys it to the air cap nozzles 13 on both sides through the air cap body. The medium conveying pipelines 2#15 on both sides respectively convey the medium into the air cap body at positions near the air cap nozzles on both sides, achieving the effects of turning, uniform flow, and pressure increase of the medium in the air cap body.

[0037] The air cap nozzles of the disturbance air cap 7, suspension air cap 8, and boiling air cap 9 are all Archimedean spiral nozzles; the angle between the nozzle outlet of the disturbance air cap 7 and the horizontal plane is -55° to -5°, the angle between the nozzle outlet of the suspension air cap 8 and the horizontal plane is -8° to 8°, and the angle between the nozzle outlet of the boiling air cap 9 and the horizontal plane is 15° to 65°;

[0038] The combined flue gas sootblowing device also includes an automatic control component. The automatic control component includes a PLC controller, a visual flue gas detection component, an electric valve group 16, a medium conveying pipeline 1#17, and a medium tank 18; the visual flue gas detection component and the electric valve group are both connected to the PLC controller. The electric valve group 16 is arranged on the medium conveying pipeline 1#17. One end of the medium conveying pipe is connected to the medium tank, and the other end is connected to the medium conveying pipeline 2#15 that is connected to the air cap nozzle 13; the visual flue gas detection component is arranged at the reheat furnace baffle flue 1 of the pulverized coal boiler to collect the dust accumulation information at the flue in real time and send the collected information to the PLC controller after data conversion. The PLC controller controls the start and stop of the electric valve group according to the comparison result of the received dust accumulation information and the preset dust accumulation threshold to control the working state of each air cap.

[0039] The visual flue gas detection component uses a video monitoring device; compressed air or steam is stored in the medium tank. The automatic control component further includes a flow sensor and a pressure sensor arranged on the medium conveying pipeline 1#17. Both the flow sensor and the pressure sensor are connected to the PLC controller through data signals, and are used to collect the pressure and flow information on the medium conveying pipeline 1#17 in real time, and send the real-time detected information to the PLC controller. The PLC controller compares the received real-time pressure and flow information with the preset pressure threshold and flow threshold, and controls the start and stop of the electric valve group according to the comparison result. In addition, it should be noted that the PLC controller, pressure sensor, flow sensor, etc. in the present invention are all relatively common electrical components, and the specific selection can be reasonably selected according to the actual design and use requirements.

[0040] The usage method of a combined flue gas sootblowing device of the present invention includes the following steps:

[0041] 1) Flue gas enters the horizontal flue 1 of the pulverized coal boiler and passes through the platen reheater 19, water wall tube panel 5, and final superheater 20 in sequence. It is extremely easy for ash to accumulate and coke at the position near the water wall tube panel 5 at the flame deflecting angle flue 1. When the visual flue gas detection component detects that ash appears in the flue and the ash thickness reaches more than 30 mm, a signal is fed back to the PLC controller;

[0042] 2) The PLC controller sends a control instruction to the electric valve group 16, so that the medium enters the disturbance air cap group 2, suspension air cap group 3, and boiling air cap group 4 for operation under the control of the PLC controller. The disturbance air cap group 2 makes the dust float upward from the bottom of the flue, passes through the suspension air cap group 3 and suspends above the air caps, and the boiling air cap group 4 lifts the dust to the middle of the flue. Finally, the dust is carried away by the flue gas;

[0043] 3) The PLC controller issues a control instruction to the electric valve group 16 again according to the dust thickness observed by the visual flue gas detection component. The default initial opening of the regulating valve is 20%. Each operation of the sootblowing device for 15 minutes is used as a feedback time interval point. The visual flue gas detection component feeds back the dust thickness situation to the PLC controller. When the dust thickness is in a growing state and the growth rate is within 50%, the opening of the electric valve group 16 increases by 10%. If the growth rate is more than 50%, the opening of the electric valve group 16 increases by 15%. The PLC controller adjusts the opening of the electric valve group 16 in real time according to the feedback of the visual flue gas detection component until the ash accumulation in the flue is adjusted to less than 30 mm;

[0044] 4) The pressure and flow signals in the medium conveying pipeline 1#17 are detected by corresponding sensors and fed back to the PLC controller. The PLC controller issues a control instruction for the electric valve group 16 according to the pressure difference between the left and right pipelines in the medium conveying pipeline 1#17, so as to make the medium pressure and flow in the disturbance air cap group 2, the suspension air cap group 3, and the boiling air cap group 4 uniform. When the ash accumulation thickness reaches the preset value, the automatic control component can be put into the sleep state. When the result detected by the visible flue gas detection component shows the situation in the above step 1) again, the automatic control component is awakened again to control the working state of the electric valve group 16.

[0045] Therefore, through actual measurement, taking a pulverized coal boiler in a power plant in Inner Mongolia as an example, the corresponding dust accumulation situation, energy consumption, etc. before and after the transformation of the pulverized coal boiler are shown in Table 1 below:

[0046] Table 1 Comparison of various data of the boiler before and after transformation

[0047]

[0048] It can be seen that by using the combined flue gas soot blowing device of the present invention, both in terms of dust accumulation and energy consumption, great improvement and enhancement have been achieved, and it has a relatively wide application prospect.

[0049] As mentioned above, it is only the preferred embodiment of the present invention. The present invention is not limited to the above-mentioned implementation manner. As long as it achieves the technical effect of the present invention by the same means, any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present disclosure shall be included within the scope of protection of the present disclosure. It shall all belong to the scope of protection of the present invention. Within the scope of protection of the present invention, various modifications and changes can be made to its technical solution and / or implementation manner.

Claims

1. A combined flue gas sootblowing device, comprising a wind cap and an automatic control component, Characterized in that: The wind cap includes a disturbance wind cap (7), a suspension wind cap (8), and a boiling wind cap (9), and the wind caps are arranged in sequence from front to back along the axial direction of the flue duct; The disturbance wind cap (7), the suspension wind cap (8), and the boiling wind cap (9) all include a wind cap body, and the wind cap body includes a wind cap nozzle (13), and the wind cap nozzles (13) are all Archimedean spiral nozzles; the included angle between the outlet of the wind cap nozzle of the disturbance wind cap and the horizontal plane is -55° to -5°, the included angle between the outlet of the wind cap nozzle of the suspension wind cap and the horizontal plane is -8° to 8°, and the included angle between the outlet of the wind cap nozzle of the boiling wind cap and the horizontal plane is 15° to 65°; The wind cap body includes a flue duct inner seal box (10) and a flue duct outer seal box (11) connected to each other. The flue duct outer seal box (11) and the flue duct inner seal box (10) are both filled with a heat preservation layer (12). Each flue duct inner seal box (10) is also provided with a wind cap nozzle (13) and a fixed support (14) for fixing the wind cap nozzle; Multiple identical disturbance wind caps (7) form a disturbance wind cap group (2), multiple identical suspension wind caps (8) form a suspension wind cap group (3), and multiple identical boiling wind caps (9) form a boiling wind cap group (4); When the disturbance wind cap group (2), the suspension wind cap group (3), and the boiling wind cap group (4) are arranged transversely along the flue duct and are arranged above the pipe wall of the rear water wall suspension pipe (5), one wind cap is arranged every 4 - 12 water wall suspension pipes. A water wall anti-abrasion protection tile (6) is also provided on the rear water wall suspension pipe (5); and each suspension wind cap (8) forms a staggered arrangement layout with the corresponding disturbance wind cap (7) and boiling wind cap (9) in the transverse direction of the flue duct; The automatic control component includes a PLC controller, a visible flue gas detection component, an electric valve group (16), a medium delivery pipeline 1# (17), and a medium tank (18); the visible flue gas detection component and the electric valve group (16) are both connected to the PLC controller. The electric valve group (16) is arranged on the medium delivery pipeline 1# (17). One end of the medium delivery pipeline 1# (17) is connected to the medium tank, and the other end is connected to a medium delivery pipeline 2# (15) communicating with the wind cap nozzle (13).

2. A combined flue gas sootblowing device according to claim 1, Characterized in that: When the wind cap group is arranged transversely along the flue duct, the disturbance wind cap group (2) includes disturbance wind caps (7) arranged at equal intervals in the same axial direction, and the axial direction is perpendicular to the axial direction of the flue duct; the suspension wind cap group (3) includes suspension wind caps (8) arranged at equal intervals in the same axial direction, and the axial direction is perpendicular to the axial direction of the flue duct; the boiling wind cap group (4) includes boiling wind caps (9) arranged at equal intervals in the same axial direction, and the axial direction is perpendicular to the axial direction of the flue duct.

3. A combined flue gas sootblowing device according to claim 1, Characterized in that: When the wind caps are arranged along the axial direction of the flue duct, the distance between two adjacent wind caps is 600 - 1200 mm.

4. A combined flue duct soot blowing device according to claim 1, characterized in that: The wind caps are arranged at the soot blower corner flue (1) of the pulverized coal boiler. Inside the soot blower corner flue (1) of the pulverized coal boiler, a platen reheater tube bank (19), a rear water wall suspension tube (5), and a final superheater tube bank (20) are sequentially arranged. The wind caps are arranged along the axial direction of the flue duct and are sequentially arranged between the platen reheater tube bank (19) and the final superheater tube bank (20) in the soot blower corner flue (1) from front to back.

5. A combined flue duct soot blowing device according to claim 1, characterized in that: The visible flue gas detection component is arranged at the soot blower corner flue of the pulverized coal boiler to collect the dust accumulation information at the flue duct in real time and send the collected information to the PLC controller after data conversion. The PLC controller controls the start and stop of the electric valve group according to the comparison result of the received dust accumulation information and the preset dust accumulation threshold value to control the working state of each wind cap.

6. A combined flue duct soot blowing device according to claim 1, characterized in that: The visible flue gas detection component adopts a video monitoring device; compressed air or steam is stored in the medium tank.

7. A combined flue duct soot blowing device according to claim 1, characterized in that: The automatic control component further includes a flow sensor and a pressure sensor arranged on the medium delivery pipeline 1# (17). The flow sensor and the pressure sensor are both connected to the PLC controller through data signals and are used to collect the pressure and flow information on the medium delivery pipeline 1# (17) in real time and send the real-time detected information to the PLC controller. The PLC controller compares the received real-time pressure and flow information with the preset pressure threshold value and flow threshold value, and controls the start and stop of the electric valve group according to the comparison result.

8. A combined flue duct soot blowing device according to claim 1, characterized in that: The external sealing box (11) of the flue duct is further provided with a medium delivery pipeline 2# (15) that penetrates the external sealing box (11) and is connected to the wind cap nozzle (13). At least three and an odd number of the medium delivery pipelines 2# (15) connected to the wind cap nozzle (13) are arranged in parallel.

9. A method for using a combined flue duct soot blowing device according to claim 1, characterized in that, the method includes the following steps: 1) When the flue gas enters the horizontal flue duct of the pulverized coal boiler and passes through the platen reheater, the water wall suspension tube, and the final superheater in sequence, it is extremely easy to accumulate ash and coke at the position near the water wall tube bank at the soot blower corner flue. When the visible flue gas detection component detects that there is ash accumulation in the flue duct and the ash accumulation reaches more than 30 mm, a signal is fed back to the PLC controller; 2) The PLC controller sends a control instruction to the electric valve group, so that the medium enters the disturbance wind cap, the suspension wind cap, and the boiling wind cap to work under the control of the PLC controller. 3) The PLC controller issues a control instruction to the electric valve group again according to the dust thickness observed by the visible flue gas detection component. The default initial opening of the regulating valve is 20%. Each operation of the soot blower for 15 minutes is used as a feedback time interval point. The visible flue gas detection component feeds back the dust thickness situation to the PLC controller. When the dust thickness is in a growing state and the growth rate is within 50%, the opening of the electric valve group increases by 10%. If the growth rate is above 50%, the opening of the electric valve group increases by 15%. The PLC controller adjusts the opening of the electric valve group in real time according to the feedback of the visible flue gas detection component until the accumulated ash in the flue is adjusted to less than 30 mm. 4) The pressure and flow signals in the medium conveying pipeline 1# (17) are detected by the corresponding sensors and fed back to the PLC controller. The PLC controller issues a control instruction to the electric valve group according to the pressure difference between the left and right pipelines in the medium conveying pipeline 1# (17) to make the medium pressure and flow in the disturbing air cap, floating air cap, and boiling air cap uniform. When the accumulated ash thickness reaches the preset value, the automatic control component can be put into the sleep state. When the situation in step 1) above appears again according to the detection result of the visible flue gas detection component, the automatic control component is awakened again to the working state of controlling the electric valve group.

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