Novel staged combustion turbulent burner with flue gas recirculation function
By designing flue gas channels and hierarchical combustion structures in the cyclone burner, the hierarchical mixing of flue gas and coal powder air and the gradual supply of oxygen are achieved, which solves the problem of poor flue gas recirculation effect in the prior art, significantly reducing the The production of NOx is improved and combustion efficiency is improved.
Patent Information
- Application Number
- CN202420389045.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-01
- Publication Date
- 2025-02-11
- Estimated Expiration
- 2034-03-01
AI Technical Summary
In the prior art, flue gas recirculation is mainly concentrated in the system arrangement, and there is a lack of equipment to return part of the recirculated flue gas back to the furnace from the burner, resulting in poor weakening of NOx concentration.
A new cyclone burner with flue gas recirculation was designed. The smoke is realized by setting the flue gas channel, the flue gas premixer, the primary air channel, the secondary air channel and the third air channel in the burner. Grading mixing with coal powder air and gradual supply of oxygen.
Through the design of the flue gas premixer, high-temperature flue gas promotes the early release of volatile components in coal powder, and the initial ignition suppression effect is obvious; the hierarchical combustion technology effectively reduces the production of NOx and is suitable for newly built and renovated thermal power plants.
Smart Images
Figure CN222459492U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a novel swirl burner with staged combustion and flue gas recirculation. Background Art
[0002] Low-nitrogen combustion technology can reduce NOx generated by pulverized coal combustion from the source, among which air staged combustion and flue gas recirculation combustion technology have been widely used. However, at present, the recycled flue gas is mostly concentrated in the system layout. Sending the flue gas back to the furnace at different positions of the boiler has a significant effect on reducing pollutant emissions. There are few combustion equipment that returns part of the recycled flue gas from the burner to the furnace. Such equipment can not only weaken the NOx concentration to a certain extent, but also play a certain inhibitory role in the generation of NOx during the combustion of fuel. This patent aims to propose a new type of swirl burner with staged combustion and flue gas recirculation. Summary of the invention
[0003] The utility model aims to provide a new type of swirl burner with staged combustion and flue gas recirculation.
[0004] The above purpose is achieved through the following technical solutions:
[0005] A new type of swirl burner with staged combustion and flue gas recirculation, which comprises: a flue gas channel, wherein the flue gas channel is placed inside a primary air channel, one end of which is connected to a flue gas regulating valve group, the high-temperature flue gas first passes through the flue gas regulating valve group to adjust the flue gas volume, and then is sent into the burner, a flue gas premixer is installed at the other end, and the distance between the end of the flue gas premixer and the nozzle needs to be greater than 40 cm, the primary air channel is placed inside a secondary air channel, one end of which is connected to a coal powder conveying channel, and a combustion stabilizing tooth is installed at the other end, the secondary air channel is placed inside a tertiary air channel, one end of which is a nozzle, and the other end is connected to a bellows, one end of the tertiary air channel is connected to the bellows, and a conical nozzle is installed at the other end.
[0006] The novel swirl burner with staged combustion and flue gas recirculation has no holes on the windward side of the flue gas premixer, and side holes and end holes are evenly arranged on the leeward side and the flat end surface. The total area of the holes needs to ensure that the flue gas outflow velocity is 1.1 to 1.4 times the primary wind velocity.
[0007] In the novel swirl burner with staged combustion and flue gas recirculation, the flue gas flow transported by the flue gas channel is directly mixed with the pulverized coal-air mixed flow transported by the primary air channel through the flue gas premixer and then ejected out of the nozzle.
[0008] The novel swirl burner with staged combustion and flue gas recirculation, the combustion stabilizing teeth are made of wear-resistant and heat-resistant materials, and a ceramic anti-wear layer is arranged on the inner side of the primary air channel or wear-resistant materials are used.
[0009] In the novel swirl burner with staged combustion and flue gas recirculation, a conical nozzle is arranged on the outer edge of the fourth air nozzle.
[0010] Beneficial effects of the utility model:
[0011] 1. The utility model is provided with a flue gas premixer, so that the flue gas flow transported by the flue gas channel and the coal powder air mixed flow transported by the primary air channel are fully mixed in the primary air channel before being sent into the furnace. The high-temperature flue gas can release more volatiles in the coal powder in advance, which has a certain promoting effect on the initial ignition of the fuel; the flue gas has a certain dilution effect on the oxygen in the primary air, and has a more obvious ignition inhibition effect on carbon particles that are relatively difficult to ignite in the initial stage. The carbon particles can ignite only after contacting the secondary air and the tertiary air, making the effect of graded combustion more obvious.
[0012] 2. The utility model is provided with secondary air channels and tertiary air channels, and the oxygen required for fuel combustion is supplied gradually, which can well realize staged combustion and greatly reduce pollutants such as NOx generated during the combustion of the mixture of flue gas and coal powder.
[0013] 3. The appearance of the utility model is very similar to the existing swirl burner in thermal power plants, and the burner and fuel can be upgraded with less modification, making it suitable for both new power plants and renovation projects of existing power plants. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Attached Figure 1 It is a structural schematic diagram of the utility model.
[0015] Attached Figure 2 It is a structural schematic diagram of the flue gas premixer.
[0016] Attached Figure 3 Yes Figure 2 Left view of .
[0017] In the figure: 1—smoke regulating valve group; 2—smoke channel; 3—primary air channel; 4—smoke premixer; 5—secondary air channel; 6—tertiary air channel; 7—conical nozzle; 8—combustion stabilizing tooth; 9—wind box. 4-1—windward side of smoke premixer; 4-2—leeward side of smoke premixer; 4-3—side hole of smoke premixer; 4-4—flat end face of smoke premixer; 4-5—hole end face of smoke premixer. DETAILED DESCRIPTION Example
[0018] like Figure 1As shown, a new type of swirl burner with staged combustion and flue gas recirculation comprises a flue gas regulating valve group 1, a flue gas channel 2, a primary air channel 3, a flue gas premixer 4, a secondary air channel 5, a tertiary air channel 6, a conical nozzle 7, a combustion stabilizing tooth 8, and a bellows 9, wherein the flue gas premixer 4 further comprises a windward side 4-1, a leeward side 4-2, a side hole 4-3, a flat end face 4-4, and an end hole 4-5.
[0019] The described new type of swirl burner with staged combustion and flue gas recirculation, the flue gas channel 2 is placed inside the primary air channel 3, one end of which is connected to the flue gas regulating valve group 1, and the other end is a flue gas premixer 4; the primary air channel 3 is placed inside the secondary air channel 5, one end of which is connected to the coal powder conveying channel, and the other end is equipped with a stable combustion tooth 8; the secondary air channel 5 is placed inside the tertiary air channel 6, one end of which is a nozzle, and the other end is connected to the wind box 9; one end of the tertiary air channel 6 is connected to the wind box 9, and the other end is equipped with a conical nozzle 7. The high-temperature flue gas first passes through the flue gas regulating valve group 1 to adjust the flue gas volume, and then is sent into the burner. The distance between the end of the flue gas premixer 4 and the nozzle must be greater than 40cm.
[0020] The combustion stabilizing teeth 8 are made of wear-resistant and heat-resistant materials, and a ceramic anti-wear layer or wear-resistant materials are arranged on the inner side of the primary air channel 3. The connection between the secondary air channel 5, the tertiary air channel 6 and the wind box 8 can be welding, flange connection or integral casting. A conical nozzle 7 is arranged on the outer edge of the quaternary air nozzle. In the actual engineering application process, the wind box is placed in the secondary air wind box of the boiler, the primary air channel is connected to the primary air channel of the boiler in the project, and the smoke channel is connected to the smoke supply pipeline in the project. Example
[0021] like Figure 2 and Figure 3 As shown, the windward side 4-1 of the flue gas premixer 4 has no holes, and the side holes 4-3 and the end holes 4-5 are evenly arranged on the leeward side 4-2 and the flat end surface 4-4, and the total area of the holes needs to ensure that the flue gas outflow velocity is 1.1 to 1.4 times the primary wind velocity.
[0022] The flue gas flow delivered by the flue gas channel 2 passes through the flue gas premixer 4 and is directly mixed with the pulverized coal-air mixed flow delivered by the primary air channel 3 in the primary air channel before being ejected out of the nozzle.
Claims
1. A new type of swirl burner with staged combustion and flue gas recirculation, comprising: The flue gas channel is characterized in that: the flue gas channel is placed inside the primary air channel, one end of which is connected to the flue gas regulating valve group, the high-temperature flue gas first passes through the flue gas regulating valve group to adjust the flue gas volume, and then is sent into the burner, and a flue gas premixer is installed at the other end, and the distance between the end of the flue gas premixer and the nozzle must be greater than 40 cm, the primary air channel is placed inside the secondary air channel, one end of which is connected to the coal powder conveying channel, and the other end is equipped with a stabilizing tooth, the secondary air channel is placed inside the tertiary air channel, one end of which is a nozzle, and the other end is connected to the bellows, one end of the tertiary air channel is connected to the bellows, and the other end is equipped with a conical nozzle.
2. The novel swirl burner with staged combustion and flue gas recirculation according to claim 1 is characterized in that: The flue gas premixer has no holes on the windward side, and side holes and end holes are evenly arranged on the leeward side and the flat end surface. The total area of the holes needs to ensure that the flue gas outflow velocity is 1.1 to 1.4 times the primary wind velocity.
3. The novel swirl burner with staged combustion and flue gas recirculation according to claim 2 is characterized in that: The flue gas flow transported by the flue gas channel passes through a flue gas premixer and is directly mixed with the coal powder and air mixed flow transported by the primary air channel in the primary air channel before being ejected out of the nozzle.
4. The novel swirl burner with staged combustion and flue gas recirculation according to claim 3 is characterized in that: The combustion stabilizing teeth are made of wear-resistant and heat-resistant materials, and a ceramic anti-wear layer is arranged on the inner side of the primary air channel or a wear-resistant material is used.
5. The novel swirl burner with staged combustion and flue gas recirculation according to claim 1 is characterized in that: A conical nozzle is arranged on the outer edge of the fourth air nozzle.