A combustion system with anti-slagging flue gas recirculation air distribution

Abstract

The application discloses a kind of anti-slagging flue gas recirculation air distribution combustion systems, including horizontal flue that furnace tail communicates, and the connecting place of furnace and horizontal flue is provided with angle of return, for smoke turning.This application reduces the flue gas temperature at furnace outlet to the greatest extent and adopts secondary large height difference grading air distribution technology, effectively reduces slagging and reduces NO X Discharge, by deflection mechanism, the spray pipe is transversely reciprocating deflected, realize the uniform diffusion of cold flue gas, balance temperature field and cover dead angle;By adjusting mechanism, the spray pipe two longitudinal adjustment angle can adjust the inclination angle of spray pipe two, control the mixing depth of overfire air and cold flue gas, ensure that the reduction zone covers the high CO concentration area, promote the decomposition of unburned material, improve the burnout rate while avoiding the risk of slagging, downward inclination enhances the penetration depth, suppresses the flame upward, further prevents slagging.

Description

Technical Field

[0001] This invention relates to the field of pulverized coal boilers, specifically to a combustion system for preventing slagging and recirculating flue gas. Background Technology

[0002] When pulverized coal boilers burn coal with strong slagging and fouling characteristics, controlling the flue gas temperature at the furnace outlet to be lower than the melting temperature of the coal ash by a certain range is the most direct and effective means to prevent slagging and fouling of the screen superheater and convective heating surfaces.

[0003] Currently, traditional furnace and burner designs generally employ a large furnace volume and a sufficiently high burnout height to ensure that the furnace water-cooled walls fully absorb heat, thereby reducing the furnace outlet flue gas temperature. However, adopting this measure will significantly increase the overall manufacturing cost of new boilers. For boilers already in operation, when the slagging and fouling characteristics of the actual coal type become stronger, it is extremely difficult to reduce the furnace outlet flue gas temperature by increasing the furnace volume since the furnace height and volume are already determined. Furthermore, reducing the furnace outlet flue gas temperature through conventional burner modifications and combustion adjustments often yields minimal results. Summary of the Invention

[0004] The purpose of this invention is to provide a combustion system for preventing slagging and recirculating flue gas to solve the technical problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a combustion system for preventing slagging and recirculating flue gas, comprising a furnace and a horizontal flue communicating with the tail of the furnace, wherein a flame deflector is provided at the connection between the furnace and the horizontal flue for flue gas diversion; a screen-type superheater and a final-stage convective heating surface are installed sequentially from left to right on the top of the inner side of the furnace; an air supply device and a pulverized coal burner are installed sequentially from top to bottom on both sides of the furnace; the air supply device supplies a first-stage separate burnout air into the furnace; a deflection mechanism is provided inside the furnace and is connected to a first nozzle; an adjustment mechanism is provided inside the furnace and is connected to a second nozzle; the deflection mechanism and the adjustment mechanism respectively ensure that the cold flue gas ejected from the first nozzle and the burnout air ejected from the second nozzle are evenly diffused, thereby preventing slagging inside the furnace;

[0006] The furnace chamber is connected to a support shaft through a bearing. A guide tube is provided on one side of the furnace chamber. The guide tube communicates with a T-shaped tube. One end of the T-shaped tubes, which are equidistantly arranged, that penetrates the furnace chamber is connected to a spray pipe through a bearing.

[0007] Inside the furnace, below the first support shaft, is a second support shaft connected by a bearing. A second guide tube is also provided on one side of the furnace. The second guide tube communicates with a second T-shaped tube. One end of the second T-shaped tube, which is equidistantly arranged, penetrates the furnace and is connected to the second nozzle by a bearing.

[0008] Preferably, a longitudinal flue communicating with a horizontal flue is provided on one side of the furnace. An economizer and an air preheater are installed sequentially from top to bottom inside the longitudinal flue. A blower communicating with the cold end inlet of the air preheater is installed on the mounting plate in the middle of one side of the longitudinal flue. The blower is used to draw cold air from the environment and send it into the cold end inlet of the air preheater. A second duct communicating with the outlet of the air preheater is provided between the longitudinal flue and the furnace. The second duct is used to send the secondary separated burnout air heated by the air preheater to the second nozzle. A dust collector is connected to the bottom end of one side of the longitudinal flue.

[0009] Preferably, a flue gas recirculation fan connected to the outlet of the dust collector is installed on the mounting plate on one side of the dust collector to pressurize the clean, cold flue gas and deliver it into the first duct. A first duct for sending the cold flue gas to the first nozzle is provided between the flue gas recirculation fan and the furnace. A first nozzle and a second nozzle are movably connected from top to bottom on one side of the furnace.

[0010] Preferably, the first nozzle sends cold flue gas into the furnace, and the second nozzle sends two-stage separated burnout air into the furnace. The end of the second nozzle away from the second T-shaped pipe is set to be flat.

[0011] Preferably, a connecting rod is hinged between adjacent nozzles, and the connecting rod is used to cause the nozzles that are equidistant to rotate laterally synchronously. A support frame is fixedly connected to the bottom end of one of the connecting rods, and an eccentric disk is welded to one end of the support shaft. The eccentric disk is used to cause the guide rod to move laterally. The guide rod is slidably connected between the eccentric disk and the support frame. When the guide rod moves laterally, it causes the support frame to rotate laterally back and forth. A protective frame is bolted to the outside of the furnace. A servo motor connected to the support shaft via a coupling is installed on the inside of one of the protective frames.

[0012] Preferably, the bottom end of the second nozzle is connected to the second support frame, which is used to make the two nozzles arranged at equal intervals form an integral structure. One end of the second support shaft is welded with an eccentric disk, which is used to drive the second guide rod to move longitudinally. The second guide rod is slidably connected between the second eccentric disk and the second support frame. When the second guide rod moves longitudinally, it causes the second support frame to deflect longitudinally. The end of the second support shaft away from the second eccentric disk extends to the inside of another protective frame.

[0013] Preferably, a drive sprocket is fitted at the end of the support shaft one that is close to the servo motor, and a driven sprocket is movably connected at the end of the support shaft two that is away from the eccentric disk two. A chain is wound around the surfaces of the drive sprocket and the driven sprocket so that the driven sprocket rotates synchronously with the drive sprocket.

[0014] Preferably, a ratchet is fitted on the surface of the second support shaft inside the driven sprocket so that the second support shaft rotates synchronously with the ratchet when the driven sprocket and the ratchet are an integral structure. A locking tooth is slidably connected to one side of the inside of the driven sprocket and engages with the ratchet. The locking tooth is used to make the driven sprocket and the ratchet an integral structure so that the ratchet and the driven sprocket move synchronously. A spring is connected between the locking tooth and the driven sprocket, and the spring is used to automatically reset the locking tooth.

[0015] Preferably, both the eccentric disk one and the eccentric disk two have annular grooves on their sides, and both the front end of the support frame one and the bottom end of the support frame two have straight grooves. The support frame one includes a side frame and a connecting block welded between the side frame and the linkage rod, and the support frame two includes a bottom frame and a support plate welded between the bottom frame and the nozzle two.

[0016] Preferably, monitors are installed at the four corners of the furnace, below the flame deflector, and on the inner side of the furnace at the inlet of the screen-type superheater.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. This anti-slagging flue gas recirculation and air distribution combustion system, within the limited furnace space of a pulverized coal boiler, adopts a secondary large height difference staged air distribution technology and minimizes the furnace outlet flue gas temperature, thereby improving the boiler's adaptability to strongly slagging and fouling coal types, ensuring operational safety, and significantly reducing manufacturing material costs for newly built boilers. For existing units, it can achieve a large proportion of strongly slagging coal blending through equipment modification, significantly reducing the fuel costs of power plants.

[0019] 2. The combustion system for preventing slagging flue gas recirculation and distribution, through the deflection mechanism, causes the eccentric disk to rotate counterclockwise, which in turn causes the nozzle to perform a transverse reciprocating deflection motion around the T-shaped pipe as the axis. This allows the cold flue gas to diffuse evenly across the cross-section of the furnace, thereby balancing the temperature field or diluting local high-temperature areas. At the same time, it expands the injection range, allowing the cold flue gas to reach the dead corners that the fixed nozzle cannot cover.

[0020] 3. The combustion system for anti-slagging flue gas recirculation and distribution, when the eccentric disk two in the adjustment mechanism is driven to rotate clockwise by the deflection mechanism, can make the nozzle two adjust its longitudinal angle around the T-shaped pipe two as the axis. This allows the inclination angle of the nozzle two to be adjusted according to the working conditions, so as to control the mixing depth of the burnout air and the cold flue gas, ensure that the reduction zone covers the high CO concentration area, accelerate the oxidation and decomposition of unburned carbon and CO, improve the burnout rate, and avoid the risk of slagging caused by local oxygen deficiency. In addition, the downward tilt enhances the penetration depth, suppresses flame upward drift, and further prevents slagging. Attached Figure Description

[0021] Figure 1 This is a three-dimensional cross-sectional structural diagram of the present invention;

[0022] Figure 2 For the present invention Figure 1 Enlarged structural diagram at point A in the middle;

[0023] Figure 3 This is a three-dimensional structural diagram from a first perspective of the present invention;

[0024] Figure 4 This is a three-dimensional structural diagram from a second perspective of the present invention;

[0025] Figure 5 This is a three-dimensional structural diagram of the deflection mechanism and adjustment mechanism of the present invention;

[0026] Figure 6 This is a three-dimensional structural diagram of the eccentric disk one and eccentric disk two of the present invention;

[0027] Figure 7 This is a three-dimensional cross-sectional structural diagram of the driven sprocket of the present invention;

[0028] Figure 8 This is a three-dimensional structural schematic diagram of the deflection mechanism of the present invention;

[0029] Figure 9 This is a three-dimensional structural diagram of the nozzle and the T-shaped tube of the present invention;

[0030] Figure 10 This is a three-dimensional structural diagram of the adjustment mechanism of the present invention;

[0031] Figure 11 This is a three-dimensional structural diagram of the nozzle 2 and the T-shaped tube 2 of the present invention;

[0032] Figure 12 This is a partial front view cross-sectional structural schematic diagram of the present invention.

[0033] In the diagram: 1. Furnace chamber; 2. Nozzle 1; 3. Nozzle 2; 4. Deflection mechanism; 401. Servo motor; 402. Support shaft 1; 403. Eccentric disc 1; 404. Guide rod 1; 405. Support frame 1; 406. Linkage rod; 407. T-tube 1; 5. Adjustment mechanism; 501. Support shaft 2; 502. Eccentric disc 2; 503. Guide rod 2; 504. Support frame 2; 505. T-tube 2; 506. Drive sprocket; 507. 508. Chain; 509. Driven sprocket; 510. Clamping tooth; 511. Spring; 512. Ratchet; 6. Flue gas recirculation fan; 7. Duct 1; 8. Blower; 9. Duct 2; 10. Monitor; 11. Pulverized coal burner; 12. Air supply device; 13. Flame deflector; 14. Horizontal flue; 15. Screen-type superheater; 16. Final stage convective heating surface; 17. Longitudinal flue; 18. Economizer; 19. Air preheater; 20. Dust collector. Detailed Implementation

[0034] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Please see Figures 1-4 and Figure 12 This invention provides a technical solution: a combustion system for preventing slagging and recirculating flue gas, comprising a furnace 1, a first duct 7, a second duct 9, an air preheater 19, a dust collector 20, and a horizontal flue 14. The horizontal flue 14 is located at the tail end of the furnace 1. A flame deflector 13 is provided at the connection between the furnace 1 and the horizontal flue 14 for flue gas diversion, guiding high-temperature flue gas to uniformly enter the horizontal flue 14 and avoiding local overheating of the heating surface. From left to right, a screen-type superheater 15 and a final-stage convective heating surface 16 are installed sequentially on the top inner side of the furnace 1. The screen-type superheater 15 is used to absorb radiation. The furnace 1 is equipped with heat and flue gas convection heat, and has the functions of slag condensation and cooling. The final stage convection heating surface 16 is used for deep recovery of waste heat from flue gas. The furnace 1 is equipped with air supply device 12 and pulverized coal burner 11 on both sides from top to bottom. The air supply device 12 sends a first-stage separate burnout air into the furnace 1. A longitudinal flue 17 connected to the horizontal flue 14 is provided on one side of the furnace 1. An economizer 18 and an air preheater 19 are installed in the longitudinal flue 17 from top to bottom. The economizer 18 is used to absorb heat from the flue gas, and the air preheater 19 is used to further absorb waste heat and heat the cold air.

[0036] Specifically, pulverized coal and primary air are injected into the main combustion zone of furnace 1 from the burner. Under oxygen-deficient conditions, volatile matter burns first. A primary separation burnout air system is then supplied to furnace 1 from the air supply device 12, delaying oxygen supply to create a reducing atmosphere (O2 < 3%) in the main combustion zone, thus burning off the generated NO. X After being reduced to N2 and cleaned by dust collector 20, the flue gas is pressurized by flue gas recirculation fan 6 and then sent into furnace 1 at a high flow rate through nozzle 2 to dilute the oxygen concentration and reduce the flue gas temperature, thereby suppressing thermal NO. X Simultaneously, the secondary separated burnout air heated by the air preheater 19 is sent into the furnace 1 through nozzle 2 3 to replenish the remaining oxygen, ensure complete combustion of residual carbon, and suppress NO. X The flue gas is generated and simultaneously turned to the horizontal flue 14 by the flame deflector 13. During this process, the flue gas is cooled by the screen superheater 15 and then enters the longitudinal flue 17 through the horizontal flue 14. After absorbing heat by the economizer 18, it further absorbs waste heat by the air preheater 19 and heats the cold air sent in by the blower 8. Finally, the flue gas is discharged to the chimney through the dust collector 20.

[0037] exist Figures 1-5 and Figure 12 In the middle of one side of the longitudinal flue 17, a blower 8 is installed on the mounting plate, which communicates with the cold end inlet of the air preheater 19. The blower 8 is used to draw cold air from the environment and send it into the cold end inlet of the air preheater 19. A duct 2 9 is provided between the longitudinal flue 17 and the furnace 1, which communicates with the outlet of the air preheater 19. The duct 2 9 is used to send the secondary separated burnout air heated by the air preheater 19 to the nozzle 2 3. The bottom end of one side of the longitudinal flue 17 Connected to dust collector 20, which is used to remove dust from low-temperature flue gas, a flue gas recirculation fan 6 connected to the outlet of dust collector 20 is installed on the mounting plate on one side of dust collector 20 to pressurize the clean, cold flue gas and deliver it into duct 7. A duct 7 is provided between flue gas recirculation fan 6 and furnace 1 to send the cold flue gas to nozzle 2. Nozzle 2 and nozzle 3 are movably connected from top to bottom on one side of furnace 1.

[0038] Specifically, the clean flue gas after passing through the dust collector 20 is used as a cooling medium and is pressurized by the recirculation fan and sent to the upper area of ​​the furnace 1 to achieve the purpose of significantly reducing the flue gas temperature at the outlet of the furnace 1.

[0039] The combustion system has been changed from a traditional single-stage air distribution to a two-stage air distribution with a large height difference. This means that while retaining the traditional separate burnout air, a higher-level separate burnout air is added. This burnout air, along with the cold flue gas, is sent into the upper part of furnace 1. This multi-stage air distribution allows for precise control of the air chemical equivalence in different areas of furnace 1, maintaining the entire combustion process in furnace 1 at low oxygen levels and low peak flame temperatures. This reduces the probability of slagging in furnace 1 and lowers NO levels. X Emission levels;

[0040] The cold flue gas is fed into the furnace 1 from below the flame deflector 13 on the upper rear wall of the furnace 1 at a higher flow rate. This pushes the rising flue gas after combustion in the furnace 1 towards the front of the furnace, solving the problem of flue gas in the vicinity of the flame deflector 13 on the rear wall of the π-type boiler being short-circuited and directly entering the horizontal flue 14. This allows more flue gas in the upper furnace 1 to flow through the area of ​​the screen-type superheater 15 for sufficient heat exchange, further reducing the flue gas temperature at the outlet of the furnace 1.

[0041] The secondary separation burnout air supplemented in the upper furnace 1 can fully cover the entire cross-section of the furnace 1, burn off the carbon and CO in the incompletely burned fly ash, and ensure that the overall combustion efficiency of the entire furnace 1 does not decrease under the low oxygen combustion state.

[0042] exist Figure 1 , Figure 2 , Figure 5 and Figures 10-12 In the middle section: nozzle 2 sends cold flue gas into furnace 1, nozzle 3 sends two-stage separated burnout air into furnace 1, and the end of nozzle 3 away from T-shaped pipe 505 is set to be flat.

[0043] Specifically, by making the end of nozzle 23 furthest from T-shaped pipe 2505 flat, the injection intensity can be enhanced while expanding the range of the two-stage separation burnout air injection, thus improving the burnout rate, reducing coal consumption, and ensuring uniform diffusion to avoid temperature spikes, peak temperatures, and NO. X The flow rate decreases, and the flattened flow channel weakens the tendency of gas to adhere to the wall, reducing the central jet velocity attenuation rate and ensuring far-end penetration.

[0044] exist Figures 2-6 and Figure 8 , Figure 9 , Figure 12 In the middle section: A deflection mechanism 4 is provided between the nozzle 2 and the furnace 1 to ensure uniform diffusion of cold flue gas. The deflection mechanism 4 includes a support shaft 402 connected to the furnace 1 via a bearing and a T-shaped pipe 407 communicating with the duct 7. One end of the T-shaped pipe 407, which is equidistantly arranged, penetrates the furnace 1 and is connected to the nozzle 2 via a bearing. A connecting rod 406 is hinged between adjacent nozzles 2. The connecting rod 406 is used to synchronously deflect the equidistant nozzles 2 laterally. A support frame 405 is fixedly connected to the bottom end of the furnace. An eccentric disk 403 is welded to one end of the support shaft 402 to move the guide rod 404 laterally. The guide rod 404 is slidably connected between the eccentric disk 403 and the support frame 405. When the guide rod 404 moves laterally, it causes the support frame 405 to reciprocate laterally. A protective frame is bolted to the outside of the furnace chamber 1. A servo motor 401 connected to the support shaft 402 via a coupling is installed on the inside of one of the protective frames.

[0045] Specifically, the servo motor 401 is started, and the output end of the servo motor 401 drives the support shaft 402 and the eccentric disk 403 to rotate counterclockwise. Since the guide rod 404 is slidably connected to the eccentric disk 403 and the support frame 405 through the annular groove and the straight groove respectively, and the nozzle 2 is connected to the T-shaped tube 407 through the bearing, the support frame 405 drives the nozzle 2 to make a lateral reciprocating deflection motion with the T-shaped tube 407 as the axis. This makes the cold flue gas evenly diffused in the cross section of the furnace 1 to balance the temperature field or dilute the local high temperature zone. At the same time, it expands the injection range so that the cold flue gas can reach the dead corners that the fixed nozzle cannot cover. In the limited furnace space of the pulverized coal boiler, the furnace outlet flue gas temperature can be reduced to the maximum extent, the boiler's adaptability to strongly slagging and fouling coal types can be improved, and the operational safety can be ensured.

[0046] exist Figure 2 , Figure 5 and Figures 10-12In the middle: An adjustment mechanism 5 for adjusting the tilt angle of the nozzle 2 3 is provided between the nozzle 2 3 and the furnace 1. The adjustment mechanism 5 includes a support shaft 2 501 connected to the furnace 1 via a bearing and a T-shaped pipe 2 505 communicating with the guide tube 2 9. One end of the T-shaped pipe 2 505, which is equidistantly arranged, passes through the furnace 1 and is connected to the nozzle 2 3 via a bearing. The bottom end of the nozzle 2 3 is connected to the support frame 2 504. The support frame 2 504 is used to make the equidistant nozzles 2 3 form an integral structure. One end of the support shaft 2 501 is welded with an eccentric disk 2 502 for driving the guide rod 2 503 to move longitudinally. The guide rod 2 503 is slidably connected between the eccentric disk 2 502 and the support frame 2 504. When the guide rod 2 503 moves longitudinally, it causes the support frame 2 504 to deflect longitudinally. The end of the support shaft 2 501 away from the eccentric disk 2 502 extends to the inside of another protective frame.

[0047] Specifically, when the second support shaft 501 and the second eccentric disk 502 rotate synchronously, the second guide rod 503 is slidably connected to the second eccentric disk 502 and the second support frame 504 through the annular groove and the straight groove, respectively. This allows the second support frame 504 to drive the second nozzle 3 to make longitudinal angle adjustments with the T-shaped pipe 505 as the axis. This allows the inclination angle of the second nozzle 3 to be adjusted according to the working conditions, so as to control the mixing depth of the burnout air and the cold flue gas, ensure that the reduction zone covers the high CO concentration area, accelerate the oxidation and decomposition of unburned carbon and CO, improve the burnout rate, and avoid the risk of slagging caused by local oxygen deficiency. In addition, the downward inclination enhances the penetration depth, suppresses the flame from rising, and further prevents slagging.

[0048] exist Figure 2 , Figure 6 , Figure 7 and Figure 10 In the middle: a drive sprocket 506 is fitted on one end of the support shaft 1 402 near the servo motor 401, and a driven sprocket 508 is movably connected to the other end of the support shaft 2 501 away from the eccentric disk 2 502. A chain 507 is wound around the surfaces of the drive sprocket 506 and the driven sprocket 508 so that the driven sprocket 508 rotates synchronously with the drive sprocket 506.

[0049] Specifically, depending on the working conditions, the output end of the servo motor 401 drives the support shaft 402 and the drive sprocket 506 to rotate clockwise. At this time, the driven sprocket 508 is driven to rotate synchronously through the chain 507.

[0050] exist Figure 2 , Figure 6 and Figure 7In the middle section: A ratchet 511 is fitted on the surface of the second support shaft 501 inside the driven sprocket 508 so that when the driven sprocket 508 and the ratchet 511 are an integral structure, the second support shaft 501 rotates synchronously with the ratchet 511. A locking tooth 509 is slidably connected to one side inside the driven sprocket 508 and engages with the ratchet 511. The locking tooth 509 is used to make the driven sprocket 508 and the ratchet 511 form an integral structure so that the ratchet 511 and the driven sprocket 508 move synchronously. A spring 510 is connected between the locking tooth 509 and the driven sprocket 508. The spring 510 is used to make the locking tooth 509 automatically reset.

[0051] Specifically, since the locking tooth 509 and the driven sprocket 508 are elastically connected by the spring 510, when the driven sprocket 508 rotates clockwise, the locking tooth 509 engages with the ratchet 511, causing the ratchet 511, the second support shaft 501, and the second eccentric disk 502 to rotate synchronously. When the driven sprocket 508 rotates counterclockwise, the ratchet 511 does not rotate.

[0052] exist Figure 2 , Figure 5 , Figure 6 and Figure 10 In the middle: eccentric disk 1 403 and eccentric disk 2 502 are both provided with annular grooves on their sides, and support frame 1 405 and support frame 2 504 are both provided with straight grooves at their front end and bottom end. Support frame 1 405 includes a side frame and a connecting block welded between the side frame and the connecting rod 406. Support frame 2 504 includes a bottom frame and a support plate welded between the bottom frame and the nozzle 2 3.

[0053] Specifically, when eccentric disk 1 403 and eccentric disk 2 502 rotate, the guide rod 1 404 moves laterally and the guide rod 2 503 moves longitudinally through the annular groove. When the guide rod 1 404 moves laterally and the guide rod 2 503 moves longitudinally, the support frame 1 405 deflects laterally and the support frame 2 504 deflects longitudinally through the straight groove.

[0054] exist Figure 1 , Figure 2 , Figure 5 and Figures 8-12 In the middle: the bearings are made of silicon nitride (Si3N4) with a SiO2 protective layer on the surface. The bearings are sealed with a labyrinth seal to prevent leakage from affecting the spraying effect. Nozzle 1-2, Nozzle 2-3, T-tube 1-407, T-tube 2-505, etc. are all coated with aluminized coating (C5-M grade anti-corrosion) and can withstand the corrosive environment of H2S concentration >2000ppm.

[0055] Specifically, adopting the above-mentioned protective methods helps to extend the service life.

[0056] exist Figure 1 and Figure 12In the middle: Monitors 10 are installed at the four corners of the furnace 1, below the flame deflector 13, and at the inlet of the screen-type superheater 15 on the inner side of the furnace 1. The monitors 10 are infrared temperature and CO concentration sensors, and low-flow-rate finned wear-resistant tubes are used to protect the monitors 10.

[0057] Specifically, the temperature and CO concentration are monitored in real time by the monitor 10, and the adjustment signal is dynamically fed back.

[0058] Pulverized coal and primary air are injected into the main combustion zone of furnace 1 from the burner. Under oxygen-deficient conditions, volatile matter burns first, and coke particles burn in suspension. Primary separation burnout air is sent into furnace 1 from the air supply device 12 to delay oxygen supply and create a reducing atmosphere (O2 < 3%) in the main combustion zone, thus reducing the NO generated. X The clean, cold flue gas, after being reduced to N2 and cleaned by dust collector 20, is pressurized by flue gas recirculation fan 6 and then sent to T-tube 407 through duct 7. It is then fed into furnace 1 at a higher flow rate through nozzle 2 to dilute the oxygen concentration, lower the flue gas temperature, and suppress thermal NO. X Simultaneously, the secondary separation burnout air heated by the air preheater 19 is sent to the T-shaped pipe 505 through the second conduit 9, and then into the furnace 1 through the second nozzle 3 to replenish the remaining oxygen, ensure complete combustion of residual carbon, reduce the carbon content of fly ash, and suppress NO. X The flue gas is generated and simultaneously turned to the horizontal flue 14 by the flame deflector 13. During this process, the flue gas is driven by the airflow on the rear wall and squeezed to the front wall, forming a flue gas flow direction that deflects to the front wall. After being fully cooled by the screen superheater 15, it reaches the final stage convective heating surface 16. Then, it enters the longitudinal flue 17 from the horizontal flue 14. After absorbing heat by the economizer 18, it further absorbs waste heat through the air preheater 19 and heats the cold air sent in by the blower 8. Finally, the flue gas is discharged to the chimney through the dust collector 20. In this way, the flue gas recirculation and air distribution can be achieved.

[0059] Simultaneously, the servo motor 401 is started. The output end of the servo motor 401 drives the support shaft 402 and the eccentric disk 403 to rotate counterclockwise. Through the sliding action of the guide rod 404, the eccentric disk 403, and the support frame 405, the support frame 405 drives the nozzle 2 to make a lateral reciprocating deflection motion with the T-shaped tube 407 as the axis, so that the cold flue gas is evenly diffused in the cross section of the furnace 1 to balance the temperature field or dilute the local high temperature area.

[0060] During this process, the output of the servo motor 401 drives the support shaft 402 and the drive sprocket 506 to rotate clockwise according to the working conditions. At this time, the driven sprocket 508 is driven to rotate synchronously through the chain 507. At the same time, the engagement of the tooth 509 with the ratchet 511 causes the ratchet 511, the support shaft 501, and the eccentric disk 502 to rotate synchronously. Through the sliding action of the guide rod 503, the eccentric disk 502, and the support frame 504, the support frame 504 drives the nozzle 3 to make longitudinal angle adjustments with the T-shaped pipe 505 as the axis. This allows the inclination angle of the nozzle 3 to be adjusted according to the working conditions in order to control the mixing depth of the burnout air and the cold flue gas, ensure that the reduction zone covers the high CO concentration area, accelerate the oxidation and decomposition of unburned carbon and CO, improve the burnout rate, and avoid the risk of slagging caused by local oxygen deficiency.

[0061] The parts used are made of high-temperature resistant materials. The electrical equipment (including but not limited to motors, electric actuators, etc.) is safely powered by an external power source and controlled by a control box. The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0062] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A kind of anti-sintering flue gas recirculation air distribution combustion system, including furnace (1) and with the horizontal flue (14) of furnace (1) tail communication, and the junction of furnace (1) with horizontal flue (14) is provided with angle of return (13), for flue gas diversion, the top of the inside of the furnace (1) is installed screen superheater (15) and last stage convection heating surface (16) from left to right in sequence, the two sides of the furnace (1) are installed air supply device (12) and pulverized coal burner (11) from top to bottom in sequence, air supply device (12) sends into primary separation type overfire air to furnace (1) inside, it is characterized by: The inside of the furnace (1) is provided with a deflection mechanism (4), the deflection mechanism (4) is connected with the nozzle one (2), the inside of the furnace (1) is provided with an adjusting mechanism (5), the adjusting mechanism (5) is connected with the nozzle two (3); the deflection mechanism (4) and the adjusting mechanism (5) respectively make the nozzle one (2) and the nozzle two (3) evenly diffuse. The inside of the furnace (1) is connected with the support shaft one (402) through the bearing, one side of the furnace (1) is provided with the pipe one (7), the pipe one (7) is communicated with the T-shaped pipe one (407), the equidistantly arranged T-shaped pipe one (407) penetrates one end of the furnace (1) and is connected with the nozzle one (2) through the bearing. The inside of the furnace (1) is connected with the support shaft two (501) below the support shaft one (402) through the bearing, one side of the furnace (1) is also provided with the pipe two (9), the pipe two (9) is communicated with the T-shaped pipe two (505), the equidistantly arranged T-shaped pipe two (505) penetrates one end of the furnace (1) and is connected with the nozzle two (3) through the bearing.

2. A flame-drying prevention flue gas recirculation air distribution combustion system according to claim 1, characterized in that: One side of the furnace (1) is provided with the longitudinal flue (17) communicated with the horizontal flue (14), the inside of the longitudinal flue (17) is sequentially installed with the economizer (18) and the air preheater (19) from top to bottom, and the mounting plate in the middle of one side of the longitudinal flue (17) is installed with the air blower (8) communicated with the cold end inlet of the air preheater (19), the air blower (8) is used for extracting the cold air from the environment and sending into the cold end inlet of the air preheater (19), the longitudinal flue (17) and the furnace (1) are provided with the pipe two (9) communicated with the outlet of the air preheater (19), and the pipe two (9) is used for sending the secondary separated type burnout wind heated by the air preheater (19) to the nozzle two (3), and the bottom end of one side of the longitudinal flue (17) is connected with the dust remover (20).

3. A flame-drying prevention flue gas recirculation air distribution combustion system according to claim 2, characterized in that: The mounting plate of one side of the dust remover (20) is installed with the flue gas recirculation fan (6) communicated with the outlet of the dust remover (20), the clean cold flue gas is pressurized and sent into the pipe one (7), the flue gas recirculation fan (6) and the furnace (1) are provided with the pipe one (7) for sending the cold flue gas to the nozzle one (2), and one side of the inside of the furnace (1) is movably connected with the nozzle one (2) and the nozzle two (3) from top to bottom.

4. The anti-slagging flue gas recirculation overfire air firing system according to claim 1, wherein: The nozzle one (2) sends the cold flue gas into the furnace (1), the nozzle two (3) sends the secondary separated type burnout wind into the furnace (1), and the end of the nozzle two (3) away from the T-shaped pipe two (505) is provided in a flat shape.

5. A deagglomerating flue gas recirculation overfire air firing system according to claim 1, wherein: A connecting rod (406) is hingedly connected between adjacent one of the spray pipes (2), and the connecting rod (406) is used for synchronously deflecting the equidistantly arranged spray pipes (2) laterally, a bottom end of one of the connecting rod (406) is fixedly connected with a support frame (405), one end of the support shaft (402) is welded with an eccentric disc (403), the eccentric disc (403) is used for moving the guide rod (404) laterally, the eccentric disc (403) and the support frame (405) are slidably connected with the guide rod (404), when the guide rod (404) moves laterally, the support frame (405) reciprocatingly deflects laterally, the outer side of the hearth (1) is boltedly connected with a protection frame, the inner side of one of the protection frame is mounted with a servo motor (401) which is connected with the support shaft (402) through a coupling.

6. A deagglomerating flue gas recirculation overfire air firing system according to claim 5, wherein: The bottom end of the spray pipe (3) is connected with a support frame (504), the support frame (504) is used for forming an integral structure of the equidistantly arranged spray pipes (3), one end of the support shaft (501) is welded with an eccentric disc (502), the eccentric disc (502) is used for driving the guide rod (503) to move longitudinally, the eccentric disc (502) and the support frame (504) are slidably connected with the guide rod (503), when the guide rod (503) moves longitudinally, the support frame (504) deflects longitudinally, the end of the support shaft (501) away from the eccentric disc (502) extends to the inner side of the other protection frame.

7. A deagglomerating flue gas recirculation overfire air firing system according to claim 6, wherein: The end of the support shaft (402) close to the servo motor (401) is sleeved with a driving sprocket (506), the end of the support shaft (501) away from the eccentric disc (502) is movably connected with a driven sprocket (508), the surfaces of the driving sprocket (506) and the driven sprocket (508) are provided with a chain (507), so that the driven sprocket (508) rotates synchronously with the driving sprocket (506).

8. A deagglomerating flue gas recirculation overfire air firing system according to claim 7, wherein: The surface of the support shaft (501) on the inner side of the driven sprocket (508) is sleeved with a ratchet wheel (511), so that the support shaft (501) rotates synchronously with the ratchet wheel (511) when the driven sprocket (508) and the ratchet wheel (511) form an integral structure, one side of the inside of the driven sprocket (508) is slidably connected with a pawl (509) which is engaged with the ratchet wheel (511), the pawl (509) is used for forming an integral structure of the driven sprocket (508) and the ratchet wheel (511), so that the ratchet wheel (511) and the driven sprocket (508) move synchronously, the pawl (509) and the driven sprocket (508) are connected with a spring (510), the spring (510) is used for automatically resetting the pawl (509).

9. A deagglomerating flue gas recirculation overfire air firing system according to claim 8, wherein: The side surfaces of the eccentric disc (403) and the eccentric disc (502) are provided with annular grooves, the front end of the support frame (405) and the bottom end of the support frame (504) are provided with straight grooves, the support frame (405) comprises a side frame and a connecting block which is welded between the side frame and the connecting rod (406), the support frame (504) comprises a bottom frame and a supporting plate which is welded between the bottom frame and the spray pipe (3).

10. The anti-slagging flue gas recirculation overfire air firing system according to claim 1, wherein: The monitor (10) is installed at the four corners of the furnace (1), below the folded angle (13), and at the entrance of the screen superheater (15) on the inner side of the furnace (1).

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