Environment-friendly fluidized bed boiler
By adding SNCR and SCR denitrification systems and multi-stage separation treatment to the fluidized bed boiler, and using urea solution and vanadium-titanium catalyst to reduce NOx concentration, the problem of excessive NOx in the flue gas of the fluidized bed boiler was solved, achieving efficient flue gas purification and improved environmental performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HANGZHOU HANGMIN XIAOCHENG THERMAL POWER CO LTD
- Filing Date
- 2025-04-30
- Publication Date
- 2026-05-08
AI Technical Summary
Existing circulating fluidized bed boilers have excessively high NOx concentrations during flue gas emissions, leading to increased maintenance costs and environmental pollution risks.
By adding an SNCR denitrification system and an SCR denitrification catalyst at appropriate locations, combined with atomizing nozzles for urea solution and a vanadium-titanium catalyst layer, NOx concentration can be reduced through multi-stage separation and reduction reactions.
It effectively reduces NOx emission concentration in flue gas, improves denitrification efficiency, achieves more efficient environmental protection results, and optimizes emission quality through tail flue and dust removal and desulfurization devices.
Smart Images
Figure CN224215320U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of fluidized bed boiler technology, specifically an environmentally friendly fluidized bed boiler. Background Technology
[0002] Circulating fluidized bed boilers are widely used in the energy industry due to their high combustion efficiency and low pollutant emissions.
[0003] However, with the increasing environmental standards and the extension of operating time, existing boilers may experience excessively high NOx emission concentrations during flue gas discharge, which increases maintenance costs and environmental pollution risks. To reduce NOx emission concentrations in flue gas, an environmentally friendly fluidized bed boiler has been proposed. Utility Model Content
[0004] To address the shortcomings of existing technologies, this application provides an environmentally friendly fluidized bed boiler. By adding an SNCR denitrification system and an SCR denitrification catalyst at appropriate locations, the NOx emission concentration in flue gas is effectively reduced, achieving a more environmentally friendly effect.
[0005] To achieve the above objectives, this application provides the following technical solution: an environmentally friendly fluidized bed boiler, comprising a furnace body, a horizontal flue, a cyclone separator, a return material small air chamber, and a denitrification assembly. The denitrification assembly includes a reducing agent storage tank and two liquid pumps installed on top of the reducing agent storage tank. The output ends of the two liquid pumps are respectively equipped with a first liquid delivery pipe and a second liquid delivery pipe. Filter components are installed on the pipe sections of both the first and second liquid delivery pipes. The output end of the first liquid delivery pipe is connected to a first atomizing nozzle, and the output end of the second liquid delivery pipe is equipped with a second atomizing nozzle. The first atomizing nozzle is embedded in the top of the horizontal flue, and its output end is located inside the horizontal flue. The top of the cyclone separator is connected to a transfer pipe, and the output end of the transfer pipe is equipped with a secondary separator. The top of the secondary separator is connected to a flue gas exhaust channel. The second atomizing nozzle is embedded in the top of the flue gas exhaust channel, and its output end is located inside the flue gas exhaust channel. Multiple vanadium-titanium catalyst layers are fixedly connected to the inner wall of the flue gas exhaust channel.
[0006] The above scheme effectively reduces NOx emission concentration in flue gas by using denitrification components, improving the environmental performance of the device. As the flue gas is transported through a horizontal flue to the cyclone separator, it reacts with urea solution atomized from the first atomizing nozzle, initially reducing NOx concentration. The flue gas then undergoes preliminary separation in the cyclone separator, followed by secondary separation through a transfer pipe to the secondary separator, where fine particles are separated. Simultaneously, the flue gas is transported through the exhaust channel, where it first reacts with urea solution from the second atomizing nozzle. The flue gas then passes through multiple vanadium-titanium catalyst layers. During this process, urea acts as a reducing agent, reducing NOx to nitrogen and water under the action of the catalyst, thus improving denitrification efficiency. This gradual denitrification process achieves higher efficiency, reduces NOx emission concentration, and is more environmentally friendly.
[0007] Furthermore, the horizontal flue is connected to the top of the furnace body, and the output end of the horizontal flue is connected to the input end of the cyclone separator.
[0008] The above scheme defines the relationship between the furnace body, the horizontal flue, and the cyclone separator. The flue gas generated by combustion inside the furnace body is transported to the cyclone separator through the horizontal flue for processing, which can separate coarse particles and facilitate subsequent repeated combustion.
[0009] Furthermore, the bottom end of the cyclone separator is connected to the top end of the return material small air chamber, the bottom end of the secondary separator is connected to the top end of the return material small air chamber, and the output end of the return material small air chamber is connected to the interior of the furnace body.
[0010] With the above scheme, the coarse particles separated by the cyclone separator and the fine particles separated by the secondary separator can be transported to the return air chamber, and then the material is transported to the furnace body for re-combustion through the return air chamber.
[0011] Furthermore, a replenishment pipe is installed on the top of the reducing agent storage tank, a controller is installed on the outer surface of the reducing agent storage tank, and all electrical components inside the denitrification assembly are electrically connected to the controller.
[0012] The above scheme allows for convenient replenishment of diluted urea solution to the reducing agent storage tank via a replenishment pipe, and the controller facilitates the operation of the electrical components inside the denitrification assembly.
[0013] Furthermore, the output end of the exhaust duct is connected to a tail flue, and an economizer and an air preheater are installed inside the tail flue.
[0014] The above scheme, through the coordinated use of the tail flue, economizer and air preheater, can achieve the effects of recovering waste heat from flue gas, improving boiler thermal efficiency, reducing fuel consumption and exhaust temperature.
[0015] Furthermore, a wet electrostatic precipitator is installed at the output end of the tail flue.
[0016] The above solution utilizes a wet electrostatic precipitator that can efficiently remove dust while also treating wet flue gas, making it particularly suitable for ultra-low emission retrofitting of combustion equipment such as coal-fired boilers and fluidized bed boilers.
[0017] Furthermore, a desulfurization tower is installed at the output end of the wet electrostatic precipitator.
[0018] The above scheme, by setting up a desulfurization tower, can remove sulfur dioxide from the flue gas emissions, thus optimizing the environmental performance of the device.
[0019] Furthermore, an iron chimney is installed at the output end of the desulfurization tower.
[0020] The above solution, by installing iron chimneys, can reduce the height of exhaust emissions and optimize emission performance.
[0021] Compared with the prior art, the technical solution of this application has the following beneficial effects:
[0022] This environmentally friendly fluidized bed boiler effectively reduces NOx emission concentration in flue gas through its denitrification components, improving the environmental performance of the device. As the flue gas is transported through a horizontal flue to the cyclone separator, it reacts with urea solution atomized by the first atomizing nozzle, initially reducing NOx concentration. The flue gas then undergoes preliminary separation in the cyclone separator, followed by secondary separation through a transfer pipe to the secondary separator, where fine particles are separated. Simultaneously, the flue gas is transported through the exhaust channel to the tail flue. In this process, the flue gas first reacts with urea solution atomized by the second atomizing nozzle, then passes through multiple vanadium-titanium catalyst layers. During this process, urea acts as a reducing agent, reducing NOx to nitrogen and water under the action of the catalyst, thus improving denitrification efficiency. This gradual denitrification process achieves more efficient denitrification, reduces NOx emission concentration, and is more environmentally friendly. Attached Figure Description
[0023] Figure 1 This is a frontal plan view of the structure of this application;
[0024] Figure 2 This is a schematic diagram of the rear view of the structure of this application;
[0025] Figure 3This is a top view of the overall structure of this application.
[0026] Figure 4 This is a first partial sectional view of the structure of this application;
[0027] Figure 5 This is a schematic diagram of the second partial cross-sectional structure of the present application.
[0028] In the picture:
[0029] 1. Furnace body; 2. Horizontal flue; 3. Cyclone separator; 4. Return material small air chamber; 5. Denitrification assembly; 501. Reducing agent storage tank; 502. Make-up pipe; 503. Liquid pump; 504. First liquid delivery pipe; 505. Second liquid delivery pipe; 506. Filter assembly; 507. First atomizing nozzle; 508. Transfer pipe; 509. Secondary separator; 510. Exhaust flue; 511. Second atomizing nozzle; 512. Vanadium-titanium catalyst layer; 513. Controller; 6. Tail flue; 7. Economizer; 8. Air preheater; 9. Wet electrostatic precipitator; 10. Desulfurization tower; 11. Iron chimney. Detailed Implementation
[0030] 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.
[0031] Please see Figure 1 , Figure 4 and Figure 5This embodiment of an environmentally friendly fluidized bed boiler includes a furnace body 1, a horizontal flue 2, a cyclone separator 3, a return material small air chamber 4, and a denitrification assembly 5. The horizontal flue 2 is connected to the top of the furnace body 1, and its output end is connected to the input end of the cyclone separator 3, defining the relationship between the furnace body 1, the horizontal flue 2, and the cyclone separator 3. The flue gas generated by combustion inside the furnace body 1 is transported to the cyclone separator 3 through the horizontal flue 2 for processing, which can separate coarse particles for subsequent repeated combustion. The bottom end of the cyclone separator 3 is connected to the top end of the return material small air chamber 4. The denitrification assembly 5 includes a reducing agent storage tank 501 and two liquid pumps 503 installed on the top of the reducing agent storage tank 501. The reducing agent storage tank 501 stores diluted urea solution, and a replenishment pipe 502 is installed on the top of the reducing agent storage tank 501, which allows for convenient replenishment of the reducing agent storage tank 501. The diluted urea solution is filled in. The output ends of the two liquid pumps 503 are respectively equipped with a first infusion pipe 504 and a second infusion pipe 505. Both the first infusion pipe 504 and the second infusion pipe 505 are equipped with filter components 506. The filter components 506 can remove impurities and prevent clogging of other components. The output end of the first infusion pipe 504 is connected to a first atomizing nozzle 507. The first atomizing nozzle 507 is embedded in the top of the horizontal flue 2. The output end of the first atomizing nozzle 507 is located inside the horizontal flue 2. When the liquid pump 503 is started, the urea solution can be delivered to the first atomizing nozzle 507 through the first infusion pipe 504. The urea solution will be atomized and sprayed into the interior of the horizontal flue 2 through the first atomizing nozzle 507, and will have a preliminary reaction with the flue gas inside the horizontal flue 2. It can convert NOx into harmless nitrogen and water in an appropriate amount, thereby achieving the effect of preliminary denitrification.
[0032] Please see Figure 1 , Figure 4 and Figure 5The output end of the second infusion pipe 505 is equipped with a second atomizing nozzle 511. The top of the cyclone separator 3 is connected to a transfer pipe 508, and the output end of the transfer pipe 508 is equipped with a secondary separator 509. The secondary separator 509 can further separate the flue gas transported by the cyclone separator 3, separating out fine particles, thereby improving the quality of flue gas emissions. The top of the secondary separator 509 is connected to a smoke exhaust channel 510, and the second atomizing nozzle 511 is embedded in the smoke exhaust channel 510. The top of the second atomizing nozzle 511 is located inside the exhaust channel 510. Multiple vanadium-titanium catalyst layers 512 are fixedly connected to the inner wall of the exhaust channel 510. When the corresponding liquid pump 503 is started, urea solution can be delivered to the second atomizing nozzle 511 through the second infusion pipe 505. Then, the second atomizing nozzle 511 atomizes the urea solution and sprays it into the exhaust channel 510, allowing it to react further with the flue gas in the exhaust channel 510. Afterward, the flue gas will pass through the vanadium-titanium... The catalyst layer 512 is used for conveying. Under the catalysis of the vanadium-titanium catalyst layer 512, the activation energy of the reaction between NOx and urea reducing agent can be significantly reduced, so that the reaction can be carried out efficiently at a lower temperature. At the same time, it can also ensure that the urea reducing agent reacts preferentially with NOx, rather than with oxygen or other components, thereby improving the denitrification efficiency and achieving the effect of gradual and complete denitrification, thus improving the environmental performance of the device. The bottom end of the secondary separator 509 is connected to the top end of the return material small air chamber 4. The output end of the return material small air chamber 4 is connected to the inside of the furnace body 1. The coarse particles separated by the cyclone separator 3 and the fine particles separated by the secondary separator 509 can be conveyed to the return material small air chamber 4. Then, the material is conveyed to the furnace body 1 for re-combustion through the return material small air chamber 4. A controller 513 is installed on the outer surface of the reducing agent storage tank 501. The electrical components inside the denitrification assembly 5 are all electrically connected to the controller 513. The controller 513 can be used to conveniently control the operation of the electrical components inside the denitrification assembly 5.
[0033] Please see Figure 1 , Figure 2 and Figure 3The exhaust duct 510 is connected to a tail flue 6 at its output end. An economizer 7 and an air preheater 8 are installed inside the tail flue 6. The tail flue 6, economizer 7 and air preheater 8 work together to recover waste heat from the flue gas, improve the thermal efficiency of the boiler, reduce fuel consumption and exhaust temperature. A wet electrostatic precipitator 9 is installed at the output end of the tail flue duct 6. The wet electrostatic precipitator 9 can efficiently remove dust and treat wet flue gas. It is particularly suitable for ultra-low emission retrofitting of combustion equipment such as coal-fired boilers and fluidized bed boilers. A desulfurization tower 10 is installed at the output end of the wet electrostatic precipitator 9. The desulfurization tower 10 can remove sulfur dioxide from the exhaust gas and optimize the environmental performance of the device. An iron chimney 11 is installed at the output end of the desulfurization tower 10. The iron chimney 11 can reduce the exhaust height and optimize the emission effect.
[0034] In this embodiment, an environmentally friendly fluidized bed boiler, through the denitrification component 5, can effectively reduce the NOx emission concentration in flue gas, improving the environmental performance of the device. As the flue gas is conveyed through the horizontal flue 2 to the cyclone separator 3, it reacts with the urea solution atomized by the first atomizing nozzle 507, achieving an initial reduction in NOx concentration. The flue gas then undergoes preliminary separation in the cyclone separator 3, followed by secondary separation through the transfer pipe 508 to the secondary separator 509, where fine particles are separated. Simultaneously, the flue gas is conveyed through the exhaust channel 510 to the tail flue 6. During this process, the flue gas first reacts with the urea solution sprayed by the second atomizing nozzle 511, and then passes through multiple vanadium-titanium catalyst layers 512. In this process, urea acts as a reducing agent, reducing NOx to nitrogen and water under the action of the catalyst, thus improving denitrification efficiency. By progressively treating the flue gas for denitrification, a more efficient denitrification process is achieved, reducing the NOx emission concentration and making the system more environmentally friendly.
[0035] The working principle of the above embodiment is as follows: When the furnace body 1 is working, the fuel is burned inside the furnace body 1, and the generated flue gas is transported to the cyclone separator 3 through the horizontal flue 2 for preliminary separation treatment. At the same time, the corresponding liquid pump 503 needs to be started so that the urea solution can be transported to the first atomizing nozzle 507 through the first liquid delivery pipe 504, and the first atomizing nozzle 507 atomizes and sprays the urea solution, so that the flue gas can react with the urea solution to achieve the effect of preliminary denitrification. The flue gas that has undergone preliminary denitrification will pass through the cyclone separator 3. Separator 3 separates coarse particles, which are then conveyed to the return air chamber 4 and subsequently back to the furnace body 1 for repeated combustion. The flue gas, after initial denitrification and separation, is conveyed through transfer pipe 508 to the secondary separator 509 for further separation, which effectively reduces particulate matter in the exhaust gas and improves recycling efficiency. The separated fine particles are also conveyed to the return air chamber 4 and then back to the furnace body 1 for repeated combustion. Chamber 4 transports the flue gas to furnace 1 for repeated combustion. After secondary separation and preliminary denitrification, the flue gas is transported through exhaust channel 510 to tail flue 6 for the next step. During the transport of the flue gas inside exhaust channel 510, the corresponding liquid pump 503 needs to be activated so that the urea solution can be atomized and sprayed through the second atomizing nozzle 511 to further react with the flue gas. Then, the flue gas is transported through a multi-layer vanadium-titanium catalyst layer 512. When the flue gas is transported through the vanadium-titanium catalyst layer 512, the activation energy of the reaction between NOx and urea solution is significantly reduced, so that the reaction can be carried out efficiently at a lower temperature. At the same time, it can also ensure that the urea solution reacts preferentially with NOx rather than with oxygen or other components, thereby improving the denitrification efficiency. Then, heat is exchanged through tail flue 6, economizer 7 and air preheater 8. Finally, the purified flue gas is discharged through wet electrostatic precipitator 9, desulfurization tower 10 and iron chimney 11. The whole process improves the environmental performance of the device by optimizing the denitrification process.
[0036] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0037] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.
Claims
1. An environmentally friendly fluidized bed boiler, comprising a boiler body (1), a horizontal flue (2), a cyclone separator (3), a return material small air chamber (4), and a denitrification assembly (5), characterized in that: The denitrification assembly (5) includes a reducing agent storage tank (501) and two liquid pumps (503) installed on the top of the reducing agent storage tank (501). The output ends of the two liquid pumps (503) are respectively equipped with a first infusion pipe (504) and a second infusion pipe (505). Filter components (506) are installed on the pipe sections of both the first infusion pipe (504) and the second infusion pipe (505). The output end of the first infusion pipe (504) is connected to a first atomizing nozzle (507), and the output end of the second infusion pipe (505) is equipped with a second atomizing nozzle (511). The first atomizing nozzle (507) is embedded in the horizontal smoke... At the top of the flue (2), the output end of the first atomizing nozzle (507) is located inside the horizontal flue (2). The top of the cyclone separator (3) is connected to a transfer pipe (508). The output end of the transfer pipe (508) is equipped with a secondary separator (509). The top of the secondary separator (509) is connected to a smoke exhaust channel (510). The second atomizing nozzle (511) is embedded in the top of the smoke exhaust channel (510), and the output end of the second atomizing nozzle (511) is located inside the smoke exhaust channel (510). The inner wall of the smoke exhaust channel (510) is fixedly connected with multiple vanadium-titanium catalyst layers (512).
2. The environmentally friendly fluidized bed boiler according to claim 1, characterized in that: The horizontal flue (2) is connected to the top of the furnace body (1), and the output end of the horizontal flue (2) is connected to the input end of the cyclone separator (3).
3. The environmentally friendly fluidized bed boiler according to claim 1, characterized in that: The bottom end of the cyclone separator (3) is connected to the top end of the return material small air chamber (4), the bottom end of the secondary separator (509) is connected to the top end of the return material small air chamber (4), and the output end of the return material small air chamber (4) is connected to the interior of the furnace body (1).
4. The environmentally friendly fluidized bed boiler according to claim 1, characterized in that: The reducing agent storage tank (501) is equipped with a replenishment pipe (502) on its top, and a controller (513) is installed on the outer surface of the reducing agent storage tank (501). All electrical components inside the denitrification assembly (5) are electrically connected to the controller (513).
5. The environmentally friendly fluidized bed boiler according to claim 1, characterized in that: The exhaust duct (510) is connected to the tail flue (6) at its output end. An economizer (7) and an air preheater (8) are installed inside the tail flue (6).
6. An environmentally friendly fluidized bed boiler according to claim 5, characterized in that: A wet electrostatic precipitator (9) is installed at the output end of the tail flue (6).
7. An environmentally friendly fluidized bed boiler according to claim 6, characterized in that: The output end of the wet electrostatic precipitator (9) is equipped with a desulfurization tower (10).
8. An environmentally friendly fluidized bed boiler according to claim 7, characterized in that: An iron chimney (11) is installed at the output end of the desulfurization tower (10).