SNCR-SCR coupling denitration system for waste incineration power plant
The SNCR-SCR coupled denitrification system for waste incineration power plants improves denitrification efficiency by optimizing the combination of SNCR and SCR, solving the problems of low denitrification efficiency and high cost in existing technologies, and achieving efficient and economical nitrogen oxide removal.
Patent Information
- Application Number
- CN202511161569.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-19
- Publication Date
- 2025-10-31
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Existing SNCR and SCR technologies for denitrification alone are insufficient to meet stringent environmental standards, especially in terms of denitrification efficiency and cost control, and are also subject to catalyst poisoning and clogging problems.
The waste-to-energy power plant adopts a coupled SNCR-SCR denitrification system. SNCR prioritizes the treatment of 60% of NOx, and the remaining part is further treated in the SCR stage. Combined with the staged use of reducing agents and the optimization of ammonia or urea solution spraying, the denitrification efficiency is improved and ammonia escape is reduced.
It achieved a total denitrification efficiency of over 90%, reduced urea consumption by 15%-20%, and controlled ammonia slip to within 8 ppm, thereby reducing operating costs and the risk of secondary pollution.
Smart Images
Figure CN120860786A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of waste incineration flue gas treatment technology, and in particular to an SNCR-SCR coupled denitrification system for waste incineration power plants. Background Technology
[0002] Waste incineration is a process in which waste is reduced in volume through appropriate thermal decomposition, combustion, melting and other reactions, and becomes residue or molten solid matter through oxidation at high temperature. The heat generated by waste incineration can be recovered to achieve the purpose of waste resource utilization. Waste incineration facilities must be equipped with flue gas treatment facilities to prevent heavy metals, organic pollutants and other pollutants from being discharged back into the environment. NOx generated during waste incineration is one of the main air pollutants. At present, SNCR or SCR technologies are commonly used for denitrification at home and abroad.
[0003] SNCR technology reduces NOx at high temperatures by injecting a reducing agent (such as urea or ammonia) into the furnace, but its denitrification efficiency is limited by the temperature window (850-1100℃) and has extremely high requirements for the arrangement of the spray guns and the uniformity of mixing. SCR technology achieves efficient denitrification at low temperatures (180-400℃) with the aid of a catalyst, but it suffers from problems such as catalyst poisoning, clogging, and high operating costs. In recent years, with increasingly stringent environmental standards (such as the EU's 2010 / 75 / EU requirement for NOx emissions to be below 200 mg / Nm³), single technologies are insufficient to meet the requirements, necessitating the development of new composite denitrification systems.
[0004] Therefore, a coupled SNCR-SCR denitrification system for waste incineration power plants is proposed to address the aforementioned technical issues. Summary of the Invention
[0005] To address the aforementioned issues, this application provides an SNCR-SCR coupled denitrification system for waste incineration power plants.
[0006] This application provides a coupled SNCR-SCR denitrification system for a waste incineration power plant, which adopts the following technical solution: A waste incineration power plant SNCR-SCR coupled denitrification system includes a waste storage bin, a combustion device and a dust removal device. A waste inlet is provided on one side of the waste storage bin, and the combustion device is connected to the bottom of the waste storage bin on the side away from the waste inlet. A semi-dry neutralization reaction tower is connected to one side of the combustion device through a pipeline. The dust removal equipment is connected to one side of the semi-dry neutralization reaction tower, and a chimney is provided on one side of the dust removal equipment. An SNCR denitrification device is connected to one side of the combustion equipment. A mixing and rectifying device is connected between the dust removal equipment and the semi-dry neutralization reaction tower through a pipeline, and an SCR denitrification reactor is connected between the dust removal equipment and the chimney.
[0007] By adopting the above technical solution, the system treats waste through incineration and makes full use of the heat generated by incineration. The exhaust gas produced after waste combustion is treated to be harmless before being discharged. The waste in the waste storage bin is sent into the combustion equipment for incineration. The flue gas from the combustion equipment is denitrified by the SNCR denitrification equipment. The denitrified gas then enters the semi-dry neutralization reaction tower for neutralization. The gas after further reaction is rectified by the mixing and rectifying device and then enters the dust removal equipment for dust removal to remove particulate matter. After the dust removal work is completed, the SCR denitrification reactor performs further denitrification, converting nitrogen oxides into harmless nitrogen and water through a catalyst. The harmlessly treated gas is discharged from the chimney.
[0008] Preferably, the combustion device includes a furnace and a flue gas treatment chamber, and a feed hopper is provided at the connection between the furnace and the waste storage bin. A slag discharge machine is connected to the bottom of the furnace, and multiple sets of combustion heating devices are provided below the furnace, and the multiple sets of combustion heating devices are arranged in a stepped manner.
[0009] Preferably, a waste heat boiler is installed inside the flue gas treatment chamber, and a secondary combustion chamber and a flue gas preheater are respectively installed on both sides of the waste heat boiler. The secondary combustion chamber is connected to the furnace, and the SNCR denitrification equipment is connected to the secondary combustion chamber.
[0010] Preferably, an air distribution duct is provided below the combustion heating equipment, the air distribution duct is connected to the flue gas preheater through a pipeline, a secondary air fan is connected above the air distribution duct, and the secondary air fan is connected to the oil burner through a pipe fitting, and an oil burner is provided at the connection between the secondary combustion chamber and the furnace.
[0011] Preferably, a steam preheater is provided on one side of the combustion equipment, and the steam preheater is connected to the flue gas preheater through a pipeline. A blower is connected to one side of the steam preheater, and the blower is connected to the waste storage bin through a pipeline. An induced draft fan is connected between the chimney and the SCR denitrification reactor through a pipeline.
[0012] By adopting the above technical solutions, the denitrification efficiency is improved and the risk of secondary pollution is reduced through the SNCR-SCR coupled denitrification system. By using the reducing agent in stages, the urea consumption is reduced by 15%-20%. SNCR is used to remove 60% of NOx first, and the remaining part is treated by the SCR stage. The total denitrification efficiency can reach more than 90%, and ammonia slip is controlled within 8 ppm.
[0013] Preferably, the SNCR denitrification device includes a connecting shell and a rotating inner ring, wherein the rotating inner ring is slidably connected inside the connecting shell, and the bottom of the rotating inner ring is connected to a plurality of swirling nozzles arranged in a ring array, the top of the connecting shell is connected to an inlet pipe, and the bottom of the connecting shell is connected to a drive motor.
[0014] Preferably, a transmission gear ring is provided on the outer side of the rotating inner ring, and a drive gear that meshes with the transmission gear ring is connected to the output shaft of the drive motor. A pipe connection groove with a top opening is provided inside the rotating inner ring, and one end of the liquid inlet pipe is inserted into the pipe connection groove.
[0015] Preferably, two sets of limiting and fixing rings are sleeved on the outside of the liquid inlet pipe, and multiple sets of auxiliary rolling balls are provided on the side of the limiting and fixing rings near the opening of the pipe connection groove. The two ends of the vortex nozzle are respectively provided with a spray head and a connector, and the connector is threaded into the pipe connection groove.
[0016] Preferably, the swirling nozzle is provided with a swirling plate, and the swirling plate includes a connecting outer ring and a connecting inner ring. Multiple sets of guide plates arranged in a ring array are connected between the connecting outer ring and the connecting inner ring, and all sets of guide plates are inclined downward.
[0017] Preferably, the mixing and rectifying device is provided with a U-shaped connecting groove that is fixedly connected to the pipe fittings, and a porous guide plate is connected to one end of the connecting groove near the semi-dry neutralization reaction tower, and a static mixer is connected to one end of the connecting groove near the dust removal equipment.
[0018] By adopting the above technical solution, the uniform spraying mechanism allows the ammonia or urea solution used for the reaction to react fully with the gas, thereby improving the denitrification rate of the waste gas and reducing the waste of ammonia or urea solution. During the rotation of the inner ring, the rotating spraying action is completed through the swirl nozzle. The ammonia or urea solution entering the swirl nozzle passes through the swirl plate and the guide plate connecting the outer ring and the inner ring. When it passes through the gaps of multiple sets of guide plates, it forms a swirl and is sprayed out from the spray head.
[0019] 1. Compared with existing technologies, this SNCR-SCR coupled denitrification system for waste incineration power plants fully utilizes the heat generated from waste incineration. The exhaust gas produced after waste combustion is treated to render it harmless before being discharged. The waste in the waste storage bin is sent into the combustion equipment for incineration. The flue gas from the combustion equipment is denitrified by the SNCR denitrification equipment. The denitrified gas then enters a semi-dry neutralization reaction tower for neutralization. The gas after further reaction is rectified by a mixing and rectifying device and then enters a dust removal device for dust removal to remove particulate matter. After dust removal, the SCR denitrification reactor performs further denitrification, converting nitrogen oxides into harmless nitrogen and water through a catalyst. The harmlessly treated gas is discharged from the chimney.
[0020] 2. Compared with existing technologies, this SNCR-SCR coupled denitrification system for waste incineration power plants improves denitrification efficiency and reduces the risk of secondary pollution through the SNCR-SCR coupled denitrification system. By using reducing agents in stages, urea consumption is reduced by 15%-20%. SNCR is used to remove 60% of NOx, and the remaining part is treated by the SCR stage, with the total denitrification efficiency reaching over 90%. Ammonia slip is controlled within 8 ppm. Through a uniform spraying mechanism, the ammonia or urea solution used for the reaction can fully react with the gas, thereby improving the denitrification rate of the waste gas and reducing the waste of ammonia or urea solution. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the overall structure of this application; Figure 2 This is a structural schematic diagram of a side cross-section of the combustion device in this application; Figure 3 This is a schematic diagram of the SNCR denitrification equipment of this application; Figure 4 This is a schematic diagram of the structure of the rotating inner ring in this application; Figure 5 This is a structural schematic diagram of the cross-section of the rotating inner ring in this application; Figure 6 This is a schematic diagram of the structure of the liquid inlet pipe in this application; Figure 7 This is a schematic diagram of the structure of the swirl nozzle in this application; Figure 8 This is a structural schematic diagram of the side cross-section of the swirl nozzle in this application; Figure 9 This is a schematic diagram of the structure at the swirl plate in this application; Figure 10 This is a structural schematic diagram of the side cross-section of the hybrid rectifier device of this application.
[0022] The attached diagram is labeled as follows: 1. Waste storage bin; 11. Waste inlet; 12. Steam preheater; 121. Blower; 2. Combustion equipment; 21. Feed hopper; 22. Furnace; 23. Slag remover; 24. Flue gas treatment chamber; 241. Secondary combustion chamber; 242. Flue gas preheater; 25. Waste heat boiler; 26. Secondary air fan; 261. Oil burner; 27. Combustion heating equipment; 28. Air distribution duct; 3. SNCR denitrification equipment; 31. Connecting shell; 311. Liquid inlet pipe; 312. Limiting and fixing ring; 313. Auxiliary ball. 32. Rotating inner ring; 321. Transmission gear ring; 322. Pipe connection groove; 33. Swirl nozzle; 331. Spray head; 332. Connector; 333. Swirl plate; 3331. Connecting outer ring; 3332. Connecting inner ring; 3333. Guide plate; 34. Drive motor; 341. Drive gear; 4. Semi-dry neutralization reaction tower; 5. Dust removal equipment; 6. Mixing and rectifying device; 61. Connecting groove; 62. Porous guide plate; 63. Static mixer; 7. Chimney; 71. Exhaust fan; 8. SCR denitrification reactor. Detailed Implementation
[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0024] The following is in conjunction with the appendix Figures 1-10 This application will be described in further detail below.
[0025] A waste incineration power plant SNCR-SCR coupled denitrification system includes a waste storage bin 1, a combustion device 2 and a dust removal device 5. A waste inlet 11 is provided on one side of the waste storage bin 1, and the combustion device 2 is connected to the bottom of the waste storage bin 1 on the side away from the waste inlet 11. A semi-dry neutralization reaction tower 4 is connected to one side of the combustion device 2 through a pipeline. The dust removal equipment 5 is connected to one side of the semi-dry neutralization reaction tower 4, and a chimney 7 is installed on one side of the dust removal equipment 5. An SNCR denitrification device 3 is connected to one side of the combustion equipment 2. A mixing and rectifying device 6 is connected between the dust removal equipment 5 and the semi-dry neutralization reaction tower 4 via a pipeline, and an SCR denitrification reactor 8 is connected between the dust removal equipment 5 and the chimney 7. The waste to be incinerated is transported into the waste storage bin 1 through the waste inlet 11, and then fed into the combustion equipment 2 for incineration. The flue gas from the combustion equipment 2 is denitrified by the SNCR denitrification device 3, and the denitrified gas then enters the semi-dry neutralization reaction tower 4 for reaction. The heavy metals and harmful gases (such as HCl and SOx) in the flue gas come into contact with the injected lime slurry, and a neutralization reaction occurs at an appropriate temperature, thereby reducing these harmful substances. The composition of the components in the flue gas is as follows: In addition, activated carbon is injected into the outlet of the reaction tower to adsorb harmful substances such as mercury and dioxins. After further reaction, the gas is rectified by the mixing and rectifying device 6 and then enters the dust removal equipment 5 for dust removal to remove particulate matter from the gas. After the dust removal work is completed, the SCR denitrification reactor 8 performs further denitrification work, converting nitrogen oxides into harmless nitrogen and water through a catalyst. The harmless gas is discharged from the chimney 7. The SCR denitrification reactor 8 adopts a "flat plate + honeycomb" double catalyst layer configuration. The dust removal equipment 5 is one or more of a cyclone dust collector and a bag dust collector. The semi-dry neutralization reaction tower 4, the dust removal equipment 5, and the SCR denitrification reactor 8 are all existing mature technologies. Their specific structures and implementation principles are existing mature technologies and will not be elaborated on here.
[0026] In a preferred embodiment, the combustion device 2 includes a furnace 22 and a flue gas treatment chamber 24. A feed hopper 21 is provided at the connection between the furnace 22 and the waste storage bin 1. A slag discharger 23 is connected to the bottom of the furnace 22. Multiple sets of combustion heating devices 27 are arranged in a stepped manner below the furnace 22. The waste in the waste storage bin 1 enters the furnace 22 through the feed hopper 21 for incineration. The furnace 22 is heated and burned by the multiple sets of combustion heating devices 27. The furnace 22 is divided into an evaporation section, a drying section, a thermal decomposition section, and a combustion section according to temperature. The completely burned waste is discharged as slag from the slag discharger 23. The specific structure of the combustion heating devices 27, the furnace 22, and the slag discharger 23, as well as the principle of the combustion reaction, are existing mature technologies and will not be described in detail here. A closable cover can be provided at the feed hopper 21 to ensure the quality of the waste entering the incineration and to facilitate the control of the dosage of the subsequent tail gas treatment reaction agents.
[0027] In a preferred embodiment, a waste heat boiler 25 is installed inside the flue gas treatment chamber 24, and a secondary combustion chamber 241 and a flue gas preheater 242 are respectively installed on both sides of the waste heat boiler 25. The secondary combustion chamber 241 is connected to the furnace 22, and the SNCR denitrification device 3 is connected to the secondary combustion chamber 241. The flue gas after combustion enters the flue gas treatment chamber 24 for treatment, and the flue gas first enters the secondary combustion chamber 241, and then passes through the waste heat boiler 25 to enter the flue gas preheater 242. The gas in the flue gas preheater 242 is preheated and then enters the semi-dry neutralization reaction tower 4 through a pipeline. The waste heat boiler 25 is used to absorb the waste heat from the combustion process and preheat the water. The water vapor and soft water formed after heating are discharged. The specific structure of the waste heat boiler 25, its external pipeline connection structure, and the subsequent utilization of waste heat are existing mature technologies. The specific structure and principle of the flue gas preheater 242 are also existing mature technologies and will not be described in detail here.
[0028] In a preferred embodiment, a distribution duct 28 is provided below the combustion heating device 27. The distribution duct 28 is connected to the flue gas preheater 242 via a pipeline. A secondary air fan 26 is connected above the distribution duct 28, and the secondary air fan 26 is connected to the oil burner 261 via a pipe fitting. An oil burner 261 is provided at the connection between the secondary combustion chamber 241 and the furnace 22. Gas is supplied to the combustion heating device 27 through the distribution duct 28 to aid combustion, and the firepower is increased by the airflow. The connection structure between the distribution duct 28 and the combustion heating device 27, as well as its specific working principle, are common in the art and will not be described in detail here. The combustion reaction in the secondary combustion chamber 241 and the furnace 22 is supplied with oxygen by the secondary air fan 26 through the oil burner 261. The oxygen supply method of the oil burner 261 and the secondary air fan 26 is also common in the art and will not be described in detail here.
[0029] In a preferred embodiment, a steam preheater 12 is provided on one side of the combustion device 2, and the steam preheater 12 is connected to the flue gas preheater 242 through a pipeline. A blower 121 is connected to one side of the steam preheater 12, and the blower 121 is connected to the waste storage bin 1 through a pipeline. An induced draft fan 71 is connected between the chimney 7 and the SCR denitrification reactor 8 through a pipeline. The harmless gas treated by the SCR denitrification reactor 8 is pumped into the chimney 7 by the induced draft fan 71 and discharged outward. The blower 121 sends the gas into the steam preheater 12. The steam preheater 12 preheats the air entering the boiler to a certain temperature through the internal heat sink. It is a device used to improve the heat exchange performance of the boiler and reduce energy consumption. The blower 121, the induced draft fan 71, and the flue gas preheater 242 are all common treatment devices in the art, and will not be described in detail here.
[0030] In a preferred embodiment, the SNCR denitrification device 3 includes a connecting outer shell 31 and a rotating inner ring 32. The rotating inner ring 32 is slidably connected within the connecting outer shell 31, and a plurality of swirling nozzles 33 arranged in a ring array are connected to the bottom of the rotating inner ring 32. An inlet pipe 311 is connected to the top of the connecting outer shell 31, and a drive motor 34 is connected to the bottom of the connecting outer shell 31. A transmission gear ring 321 is provided on the outer side of the rotating inner ring 32, and a drive gear 341 meshing with the transmission gear ring 321 is connected to the output shaft of the drive motor 34. A pipe connection groove 322 with an open top is opened inside the rotating inner ring 32, and one end of the inlet pipe 311 is inserted into the pipe connection groove 322. Nitrogenation device 3 directly introduces ammonia or urea solution into the combustion zone to undergo a non-catalytic reduction reaction with NOx, converting it into nitrogen and water vapor. The outer casing 31 is fixedly connected to the outside of the combustion device 2, while the rotating inner ring 32 can rotate inside the outer casing 31. The external ammonia or urea solution enters the pipe connection groove 322 of the rotating inner ring 32 inside the outer casing 31 through the liquid inlet pipe 311. The drive motor 34 drives the transmission gear ring 321 and the rotating inner ring 32 connected to it to rotate through the drive gear 341. During the rotation, the rotating inner ring 32 completes the rotational spraying action through the swirl nozzle 33, so that the ammonia or urea solution can fully react with the waste gas.
[0031] In a preferred embodiment, two sets of limiting and fixing rings 312 are sleeved on the outer side of the liquid inlet pipe 311, and multiple sets of auxiliary rolling balls 313 are provided on the side of the limiting and fixing rings 312 near the opening of the pipe connection groove 322. The two ends of the vortex nozzle 33 are respectively provided with a spray head 331 and a connector 332, and the connector 332 is threaded into the pipe connection groove 322. The liquid inlet pipe 311 is connected to the pipe connection groove 322 through the limiting and fixing rings 312 to prevent the liquid inlet pipe 311 from detaching during the rotation of the inner ring 32. During the rotation of the inner ring 32, the limiting and fixing rings 312 complete a smooth sliding movement through the auxiliary rolling balls 313 on their inner side. Since the pipe connection groove 322 has a small opening and a large bottom structure, it is not easy to be thrown out during rotation. The liquid in the pipe connection groove 322 enters the vortex nozzle 33 through the connector 332.
[0032] In a preferred embodiment, a swirl plate 333 is provided inside the swirl nozzle 33, and the swirl plate 333 includes a connecting outer ring 3331 and a connecting inner ring 3332. Multiple sets of guide plates 3333 arranged in a ring array are connected between the connecting outer ring 3331 and the connecting inner ring 3332, and all sets of guide plates 3333 are inclined downward. Ammonia gas or urea solution entering the swirl nozzle 33 passes through the swirl plate 333 and passes through the guide plate 3333 between the connecting outer ring 3331 and the connecting inner ring 3332. When it passes through the gaps of the multiple sets of guide plates 3333, a swirl is formed and sprayed out from the spray head 331.
[0033] In a preferred embodiment, the mixing and rectifying device 6 is provided with a U-shaped connecting groove 61 fixedly connected to the pipe fittings. A porous guide plate 62 is connected to one end of the connecting groove 61 near the semi-dry neutralization reaction tower 4, and a static mixer 63 is connected to the other end of the connecting groove 61 near the dust removal equipment 5. The mixing and rectifying device 6 optimizes the uniformity of ammonia distribution through the porous guide plate 62 and the static mixer 63. The static mixer 63 is a high-efficiency mixing device without moving parts. Its basic working mechanism is to use the mixing unit fixed in the pipe to change the flow state of the fluid in the pipe, so as to achieve good dispersion and full mixing between different fluids. The static mixer 63 is an existing mature technology and will not be described in detail here.
[0034] The working process of this application is as follows: First, the garbage to be incinerated is transported into the garbage storage bin 1 through the garbage inlet 11, and the garbage in the garbage storage bin 1 enters the furnace 22 through the feed hopper 21 for incineration. The garbage that has been completely burned is discharged as slag through the slag discharge machine 23. The flue gas after combustion enters the flue gas treatment chamber 24 for treatment. The flue gas first enters the secondary combustion chamber 241. The combustion reaction in the secondary combustion chamber 241 and the furnace 22 is supplied with oxygen by the secondary fan 26 through the oil burner 261. External ammonia or urea solution enters the pipe connection groove 322 of the rotating inner ring 32 inside the connecting housing 31 through the inlet pipe 311. The drive motor 34 drives the transmission gear ring 321 and the rotating inner ring 32 connected thereto to rotate through the drive gear 341. The ammonia or urea solution entering the swirl nozzle 33 passes through the swirl plate 333 and then through the guide plate 3333 between the connecting outer ring 3331 and the connecting inner ring 3332, and passes through multiple sets of... When the gaps in the guide plate 3333 are filled, a swirling flow is formed and sprayed out from the spray head 331. The ammonia or urea solution entering the swirling nozzle 33 passes through the swirling plate 333 and passes through the guide plate 3333 connecting the outer ring 3331 and the inner ring 3332. When it passes through the gaps in multiple sets of guide plates 3333, a swirling flow is formed and sprayed out from the spray head 331. The ammonia or urea solution enters the combustion zone and undergoes a non-catalytic reduction reaction with NOx, converting it into nitrogen and water vapor. After denitrification by the SNCR denitrification equipment 3, the gas enters the flue gas preheater 242 through the waste heat boiler 25 for preheating. The denitrified gas then enters the semi-dry neutralization reaction tower 4 for reaction, where heavy metals and harmful gases (such as HCl and SOx) in the flue gas come into contact with the injected lime slurry and undergo a neutralization reaction at an appropriate temperature, thereby reducing the content of these harmful components in the flue gas. In addition, activated carbon is injected into the outlet of the reaction tower to adsorb harmful substances such as mercury and dioxins. The gas after further reaction is rectified by the mixing and rectifying device 6 and then enters the dust removal equipment 5 for dust removal to remove particulate matter from the gas. After the dust removal work is completed, the SCR denitrification reactor 8 performs further denitrification work, converting nitrogen oxides into harmless nitrogen and water through a catalyst. The harmless gas is discharged from the chimney 7.
[0035] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.
Claims
1. A waste-to-energy incineration plant SNCR-SCR coupled denitrification system, comprising a waste storage bin (1), a combustion device (2), and a dust removal device (5), characterized in that: The waste storage bin (1) is provided with a waste inlet (11) on one side, and the combustion device (2) is connected to the bottom of the waste storage bin (1) on the side away from the waste inlet (11). The side of the combustion device (2) is connected to a semi-dry neutralization reaction tower (4) through a pipeline. The dust removal device (5) is connected to one side of the semi-dry neutralization reaction tower (4), a chimney (7) is provided on one side of the dust removal device (5), an SNCR denitrification device (3) is connected to one side of the combustion device (2), a mixing and rectifying device (6) is connected between the dust removal device (5) and the semi-dry neutralization reaction tower (4) through a pipeline, and an SCR denitrification reactor (8) is connected between the dust removal device (5) and the chimney (7).
2. The SNCR-SCR coupled denitrification system for a waste incineration power plant according to claim 1, characterized in that: The combustion device (2) includes a furnace (22) and a flue gas treatment chamber (24), and a feed hopper (21) is provided at the connection between the furnace (22) and the waste storage bin (1). A slag discharge machine (23) is connected to the bottom of the furnace (22). Multiple sets of combustion heating devices (27) are provided below the furnace (22), and the multiple sets of combustion heating devices (27) are arranged in a stepped manner.
3. The SNCR-SCR coupled denitrification system for a waste incineration power plant according to claim 2, characterized in that: The flue gas treatment chamber (24) is equipped with a waste heat boiler (25), and a secondary combustion chamber (241) and a flue gas preheater (242) are respectively provided on both sides of the waste heat boiler (25). The secondary combustion chamber (241) is connected to the furnace (22), and the SNCR denitrification device (3) is connected to the secondary combustion chamber (241).
4. The SNCR-SCR coupled denitrification system for a waste incineration power plant according to claim 3, characterized in that: Below the combustion heating device (27) is a distribution pipe (28), which is connected to the flue gas preheater (242) through a pipeline. Above the distribution pipe (28) is a secondary air fan (26), which is connected to an oil burner (261) through a pipe fitting. An oil burner (261) is provided at the connection between the secondary combustion chamber (241) and the furnace (22).
5. The SNCR-SCR coupled denitrification system for a waste incineration power plant according to claim 4, characterized in that: A steam preheater (12) is provided on one side of the combustion device (2), and the steam preheater (12) is connected to the flue gas preheater (242) through a pipeline. A blower (121) is connected to one side of the steam preheater (12), and the blower (121) is connected to the waste storage bin (1) through a pipeline. An induced draft fan (71) is connected between the chimney (7) and the SCR denitrification reactor (8) through a pipeline.
6. The SNCR-SCR coupled denitrification system for a waste incineration power plant according to claim 5, characterized in that: The SNCR denitrification device (3) includes a connecting shell (31) and a rotating inner ring (32), and the rotating inner ring (32) is slidably connected inside the connecting shell (31). The bottom of the rotating inner ring (32) is connected to a plurality of swirling nozzles (33) arranged in a ring array. The top of the connecting shell (31) is connected to a liquid inlet pipe (311), and the bottom of the connecting shell (31) is connected to a drive motor (34).
7. The SNCR-SCR coupled denitrification system for a waste incineration power plant according to claim 6, characterized in that: A transmission gear ring (321) is provided on the outer side of the rotating inner ring (32), and a drive gear (341) meshing with the transmission gear ring (321) is connected to the output shaft of the drive motor (34). A pipe connection groove (322) with an open top is provided in the rotating inner ring (32), and one end of the liquid inlet pipe (311) is inserted into the pipe connection groove (322).
8. The SNCR-SCR coupled denitrification system for a waste incineration power plant according to claim 7, characterized in that: Two sets of limiting and fixing rings (312) are sleeved on the outside of the liquid inlet pipe (311), and multiple sets of auxiliary rolling balls (313) are provided on the side of the limiting and fixing rings (312) near the opening of the pipe connection groove (322). Spray head (331) and connector (332) are respectively provided at both ends of the swirl nozzle (33), and the connector (332) is threaded into the pipe connection groove (322).
9. The SNCR-SCR coupled denitrification system for a waste incineration power plant according to claim 8, characterized in that: The swirling nozzle (33) is provided with a swirling plate (333), and the swirling plate (333) includes a connecting outer ring (3331) and a connecting inner ring (3332). Multiple sets of guide plates (3333) arranged in a ring array are connected between the connecting outer ring (3331) and the connecting inner ring (3332), and the multiple sets of guide plates (3333) are inclined downward.
10. The SNCR-SCR coupled denitrification system for a waste incineration power plant according to claim 1, characterized in that: The mixing and rectifying device (6) is provided with a U-shaped connecting groove (61) that is fixedly connected to the pipe fittings. A perforated guide plate (62) is connected to one end of the connecting groove (61) near the semi-dry neutralization reaction tower (4). A static mixer (63) is connected to one end of the connecting groove (61) near the dust removal equipment (5).