Cyclone burner for circulating ammonia-doped flue gas

Abstract

The invention discloses an ammonia-doped flue gas circulation turbulent burner which comprises an ammonia fuel pipe, a flue gas pipe and a primary air pipe assembly, the ammonia fuel pipe comprises a flowing section and an outflow section, and a plurality of outflow holes are formed in the peripheral wall of the outflow section; a diversion fire-resistant mechanism is arranged on the peripheral wall of one end, close to the outlet end, of the flue gas pipe, the outer diameter of a first section of the diversion fire-resistant mechanism is gradually increased, the outer diameter of a second section is unchanged, and the outer diameter of a third section is gradually reduced; the flue gas pipe is sleeved with the primary air pipe assembly, a primary air channel is defined by the primary air pipe assembly and the flue gas pipe together and used for conveying primary air and pulverized coal, and a horn mouth is formed in the end, close to the outlet end, of the primary air pipe assembly; the end, close to the outlet end, of the smoke pipe does not exceed the flowing section in the direction from the inlet end to the outlet end. According to the turbulent burner, the reduction effect of ammonia fuel on NOx generated by pulverized coal combustion can be enhanced, NOx generation is reduced, and the environmental protection property of the turbulent burner in the using process is improved.

Description

Technical Field

[0001] The invention mainly relates to the technical field of burners, and in particular to a swirl burner with ammonia-doped flue gas circulation. Background Art

[0002] In the existing technology, ammonia-coal blending as a power generation fuel for coal-fired power plants can achieve carbon emission reduction in the power system, and this technology is in line with my country's energy conditions. However, ammonia-blended combustion leads to high NOx emissions and other problems, affecting the environmental protection of the swirl burner during use. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a swirl burner with ammonia-doped flue gas circulation, which can enhance the reduction effect of ammonia fuel on NOx generated by coal powder combustion, reduce NOx generation, and improve the environmental protection of the swirl burner during use.

[0004] According to the swirl burner with ammonia-doped flue gas circulation according to the embodiment of the present invention, it comprises an ammonia fuel pipe, a flue gas pipe and a primary air pipe assembly, the ammonia fuel pipe comprises a flow section and an outflow section, the axial ends of the flow section are respectively an inlet end and an outlet end, one axial end of the outflow section is connected to the outlet end of the flow section, and the other end is closed, and along the direction from the inlet end to the outlet end, the peripheral wall of the outflow section is inclined toward the direction close to the axis of the outflow section, and a plurality of outflow holes are provided on the peripheral wall of the outflow section, and the plurality of outflow holes are sequentially spaced along the circumferential direction of the outflow section; the flue gas pipe is sleeved outside the ammonia fuel pipe and defines a flue gas channel together with the ammonia fuel pipe, and a flow guide and a resistance is provided on the outer peripheral wall of one end of the flue gas pipe close to the outlet end The fire-proof mechanism comprises a flow-guiding fire-proof mechanism extending in a ring shape along the circumferential direction of the flue gas pipe, and along the direction from the inlet end to the outlet end, the flow-guiding fire-proof mechanism comprises a first section, a second section and a third section connected in sequence, the outer diameter of the first section gradually increases, the outer diameter of the second section remains unchanged, and the outer diameter of the third section gradually decreases; the primary air duct assembly is sleeved outside the flue gas pipe and defines a primary air channel together with the flue gas pipe for conveying primary air and coal powder, and a bell mouth is provided at one end of the primary air duct assembly close to the outlet end, and the inner diameter of the bell mouth gradually increases along the direction from the inlet end to the outlet end; wherein, along the direction from the inlet end to the outlet end, the end of the flue gas pipe close to the outlet end does not exceed the flow section.

[0005] According to the swirl burner with ammonia-doped flue gas circulation according to the embodiment of the present invention, a flow-guiding refractory mechanism is arranged on the outer peripheral wall of one end of the flue gas pipe near the outlet end, and the outer diameter of the flow-guiding refractory mechanism gradually increases, then remains unchanged, and finally gradually decreases, so that an annular cavity is formed in the primary air channel that first shrinks, then becomes straight, and then expands, so that part of the primary air channel forms an annular Laval nozzle-like shape, so that the pulverized coal in the primary air is separated into thick and thin when passing through the flow-guiding refractory mechanism, and the rigidity of the primary air can be enhanced at the same time; and along the direction from the inlet end to the outlet end, the end of the flue gas pipe near the outlet end does not exceed the flow section, and the ammonia fuel can be better mixed with the flue gas flowing out of the flue gas pipe when flowing out from the outlet hole, thereby ensuring the dilution effect of the flue gas on the ammonia fuel, so that a certain oxygen-deficient environment is obtained when the ammonia fuel is burned, the oxidation effect of the ammonia fuel is weakened, the reduction effect of the ammonia fuel on NOx generated by the combustion of coal powder is enhanced, the generation of NOx is reduced, the environmental protection of the swirl burner during use is improved, and the operating cost of the swirl burner is reduced.

[0006] In some embodiments of the present invention, the ammonia fuel pipe is movable along the axial direction of the flow section, and the swirl burner also includes a driving mechanism, which is arranged at one end of the flow section close to the inlet end and is used to drive the ammonia fuel pipe to move along the axial direction of the ammonia fuel pipe.

[0007] In some embodiments of the present invention, the driving mechanism includes a driving motor and a transmission mechanism, and the transmission mechanism is connected to both the flow section and the output shaft of the driving motor, and is used to drive the ammonia fuel pipe to move along the axial direction of the ammonia fuel pipe.

[0008] In some embodiments of the present invention, on the cross-section where the axis of the flue pipe is located, the angle between the outer wall of the first section and the axis of the ammonia fuel pipe is A and satisfies: 15°≤A≤35°; and / or, on the cross-section where the axis of the flue pipe is located, the angle between the outer wall of the third section and the axis of the ammonia fuel pipe is B and satisfies: 15°≤B≤35°.

[0009] In some embodiments of the present invention, on the cross section where the axis of the primary air duct assembly is located, the angle between the inner circumferential wall of the bell mouth and the axis of the primary air duct assembly is C and satisfies: 15°≤C≤35°.

[0010] In some embodiments of the present invention, on the cross section where the axis of the ammonia fuel pipe is located, the angle between the peripheral wall of the outflow section and the axis of the outflow section is D and satisfies: 15°≤D≤35°.

[0011] In some embodiments of the present invention, the axis of the outflow hole is perpendicular to the peripheral wall of the outflow section.

[0012] In some embodiments of the present invention, the flow section includes an inner fuel pipe and an outer sleeve, the outer sleeve is sleeved on the outside of the inner fuel pipe, the outer sleeve is a fire-resistant pipe, and at least a portion of the outer sleeve is passed through the flue gas pipe.

[0013] In some embodiments of the present invention, the ammonia-doped flue gas circulation swirl burner also includes a secondary air duct assembly, which is sleeved on at least part of the outer side of the primary air duct assembly close to the outlet end and together with the primary air duct assembly defines a secondary air channel for conveying secondary air.

[0014] In some embodiments of the present invention, the secondary air duct assembly includes a first tube and a second tube, the first tube is sleeved on at least part of the outer side of the primary air duct assembly near the outlet end, the first tube and the primary air duct assembly define an inner swirl channel, and along the direction from the inlet end to the outlet end, an inner bellows and inner blades are sequentially provided on one side of the inner swirl channel near the inlet end; the second tube is sleeved on at least part of the outer side of the first tube near the outlet end, the second tube and the first tube define an outer swirl channel, and along the direction from the inlet end to the outlet end, an outer bellows and outer blades are sequentially provided on one side of the outer swirl channel near the inlet end.

[0015] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0017] Figure 1 is a schematic diagram of a swirl burner according to an embodiment of the present invention;

[0018] Figure 2 yes Figure 1 The enlarged view of point A in the middle;

[0019] Figure 3 yes Figure 1 The enlarged view of point B in the middle;

[0020] Figure 4 FIG. 4 is a side view of an outflow section of an ammonia fuel pipe of a swirl burner according to an embodiment of the present invention.

[0021] Reference numerals:

[0022] 100. Swirl burner;

[0023] 1. ammonia fuel pipe; 11. flow section; 111. inner fuel pipe; 112. outer sleeve; 12. outflow section; 121. outflow hole; 13. inlet end; 14. outlet end;

[0024] 2. Smoke pipe; 21. Smoke channel; 22. Flow-guiding refractory mechanism; 221. First section; 222. Second section; 223. Third section; 23. Pipe body; 24. Smoke inlet pipe;

[0025] 3. Primary air duct assembly; 31. Primary air channel; 32. Bell mouth; 33. Primary pipe; 34. Primary air inlet pipe;

[0026] 4. driving mechanism; 41. driving motor; 42. transmission mechanism;

[0027] 5. Secondary air duct assembly; 51. First tube; 511. Inner swirl channel; 512. Inner bellows; 513. Inner blades; 52. Second tube; 521. Outer swirl channel; 522. Outer bellows; 523. Outer blades; 53. Secondary air channel. DETAILED DESCRIPTION

[0028] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] Reference below Figure 1-Figure 4 A swirl burner 100 with ammonia-doped flue gas circulation according to an embodiment of the present invention is described.

[0032] like Figure 1 As shown, the swirl burner 100 with ammonia-doped flue gas circulation according to an embodiment of the present invention includes an ammonia fuel pipe 1, a flue gas pipe 2 and a primary air pipe assembly 3.

[0033] Specifically, Figure 1 , Figure 2 and Figure 4 As shown, the ammonia fuel pipe 1 can provide a conveying channel for the ammonia fuel. The ammonia fuel pipe 1 includes a flow section 11 and an outflow section 12. The axial ends of the flow section 11 are respectively an inlet end 13 and an outlet end 14. One axial end of the outflow section 12 is connected to the outlet end 14 of the flow section 11, and the other end is closed. Along the direction from the inlet end 13 to the outlet end 14, the peripheral wall of the outflow section 12 faces the direction close to the axis of the outflow section 12 (such as Figure 1 A plurality of outflow holes 121 are provided on the peripheral wall of the outflow section 12, and the plurality of outflow holes 121 are sequentially spaced apart along the circumferential direction of the outflow section 12.

[0034] It can be understood that the outflow section 12 is designed as a circular frustum structure, and the outflow holes 121 are arranged on the peripheral wall of the outflow section 12, which are arranged in sequence along the circumferential direction of the outflow section 12. The hole structure promotes the uniform distribution of the ammonia fuel at the outlet of the ammonia fuel pipe 1, and further improves the combustion efficiency and stability of the ammonia fuel of the swirl burner 100.

[0035] like Figure 1 and Figure 2 As shown, the smoke pipe 2 is sleeved outside the ammonia fuel pipe 1 and defines a smoke channel 21 together with the ammonia fuel pipe 1. The outlet of the smoke channel 21 cooperates with the outflow section 12 of the circular cone, so that the smoke can be incident straight to the position where it mixes with the ammonia fuel, so that the smoke can fully dilute the ammonia fuel incident from the outflow hole 121.

[0036] like Figure 1 and Figure 2As shown, the primary air duct assembly 3 is sleeved outside the flue gas pipe 2 and defines a primary air channel 31 together with the flue gas pipe 2 for conveying primary air and pulverized coal. A flow-guiding refractory mechanism 22 is provided on the outer peripheral wall of one end of the flue gas pipe 2 close to the outlet end 14. The flow-guiding refractory mechanism 22 extends in a ring shape along the circumferential direction of the flue gas pipe 2. From the inlet end 13 to the outlet end 14, the flow-guiding refractory mechanism 22 includes a first section 221, a second section 222 and a third section 223 connected in sequence. The outer diameter of the first section 221 gradually increases, the outer diameter of the second section 222 remains unchanged, and the outer diameter of the third section 223 gradually decreases. An annular cavity is formed in the primary air channel 31, which first shrinks, then becomes straight, and finally expands. The primary air duct assembly 3 and the portion of the flue gas pipe 2 provided with the guide refractory structure 22 form an annular Laval nozzle shape, so that the pulverized coal transported by the primary air can be concentrated in the first section 221, thereby increasing the pulverized coal concentration in the portion of the primary air channel 31 close to the guide refractory structure 22, and then flows stably through the second section 222, thereby improving the stability of pulverized coal transportation, and then expands to utilize the inertia of the pulverized coal to separate the thick and thin air from the wind, while improving the rigidity of the primary air, thereby improving the combustion stability of the swirl burner 100 under low-load operation, ensuring the full combustion of the pulverized coal, and improving the combustion efficiency.

[0037] At the same time, if Figure 1 and Figure 2 As shown, the inner diameter of the second section 222 is kept constant, so as to further stabilize the material transmission state after concentration, avoid turbulence in the primary air duct channel, and ensure the stability of coal powder material transmission.

[0038] A bell mouth 32 is provided at one end of the primary air duct assembly 3 near the outlet end 14. The inner diameter of the bell mouth 32 gradually increases from the inlet end 13 to the outlet end 14. The primary air near the bell mouth 32 can be transported to the peripheral area of ​​the bell mouth 32, and a high oxygen zone is formed at the bell mouth 32, which is convenient for the coal powder to be fully burned in the high oxygen zone, and a low oxygen combustion zone is formed with the ammonia fuel mixed with flue gas on the side of the guide refractory mechanism 22 near the outlet end 14. It can not only ensure the rigidity of the primary air, but also ensure the separation of the primary air and the coal powder, while inhibiting the oxidation of the ammonia fuel, promoting the reduction effect of the ammonia fuel on the NOx generated by the combustion of the coal powder, reducing the generation of NOx, improving the environmental protection of the coal-fired boiler during use, reducing the operating cost of the coal-fired boiler, and ensuring the efficiency of the ammonia-mixed combustion.

[0039] Among them, along the direction from the inlet end 13 to the outlet end 14, the end of the flue gas pipe 2 close to the outlet end 14 does not exceed the flow section 11. When the ammonia fuel flows out from the outflow hole 121, it can be well mixed with the flue gas flowing out of the flue gas pipe 2, ensuring the dilution effect of the flue gas on the ammonia fuel, so that a certain oxygen-deficient environment is obtained when the ammonia fuel is burned, the oxidation effect of the ammonia fuel is weakened, the reduction characteristics of the ammonia fuel are enhanced, and the generation of NOx is reduced.

[0040] According to the swirl burner 100 with ammonia-doped flue gas circulation of the embodiment of the present invention, a flow-guiding refractory mechanism 22 is provided on the outer peripheral wall of one end of the flue gas pipe 2 close to the outlet end 14, and the outer diameter of the flow-guiding refractory mechanism 22 gradually increases, then remains unchanged, and finally gradually decreases, so that an annular cavity that first shrinks, then becomes straight, and then expands is formed in the primary air channel 31, so that part of the primary air channel 31 forms an annular shape similar to a Laval nozzle, so that the coal powder in the primary air is separated into thick and thin when passing through the flow-guiding refractory mechanism 22, and the rigidity of the primary air can be enhanced at the same time. ; and along the direction from the inlet end 13 to the outlet end 14, the end of the flue gas pipe 2 close to the outlet end 14 does not exceed the flow section 11, and the ammonia fuel can be better mixed with the flue gas flowing out of the flue gas pipe 2 when flowing out from the outlet hole 121, thereby ensuring the dilution effect of the flue gas on the ammonia fuel, so that a certain oxygen-deficient environment is obtained during the combustion of the ammonia fuel, weakening the oxidation effect of the ammonia fuel, enhancing the reduction effect of the ammonia fuel on the NOx generated by the combustion of coal powder, reducing the generation of NOx, improving the environmental protection of the swirl burner 100 during use, and reducing the operating cost of the swirl burner 100.

[0041] In this embodiment, the guide refractory structure 22 is a refractory material member, which can enhance the refractory performance of the structure near the outlet end 14 of the primary air and enhance the stability and safety of the ammonia fuel combustion.

[0042] In some embodiments of the present invention, Figure 1 and Figure 3 As shown, the ammonia fuel pipe 1 is movable along the axial direction of the flow section 11, and the swirl burner 100 also includes a driving mechanism 4, which is arranged at one end of the flow section 11 close to the inlet end 13, and is used to drive the ammonia fuel pipe 1 to move along the axial direction of the ammonia fuel pipe 1. The driving mechanism 4 can push or pull the ammonia fuel pipe 1 along the axial direction of the flow section 11, thereby changing the specific position of the outflow section 12 of the ammonia fuel pipe 1 relative to the outlet of the flue gas pipe 2 close to the outlet end 14 and the bell mouth 32 of the primary air duct assembly 3, which can meet the ammonia-blended combustion under different combustion conditions, improve the adaptability and application range of the swirl burner 100, greatly improve the flexibility of the swirl burner 100 in fuel mixing and combustion control, ensure the uniformity of the ammonia-blended combustion of the swirl burner 100 under different combustion loads, improve the reliability and stability of the ammonia-blended combustion of the swirl burner 100, and provide users with the possibility of adjusting combustion parameters according to actual needs.

[0043] Furthermore, if Figure 1 and Figure 3As shown, the driving mechanism 4 includes a driving motor 41 and a transmission mechanism 42. The transmission mechanism 42 is connected to the flow section 11 and the output shaft of the driving motor 41, and is used to drive the ammonia fuel pipe 1 to move along the axial direction of the ammonia fuel pipe 1. It can stably and reliably drive the ammonia fuel pipe 1 to move along the axial direction of the ammonia fuel pipe 1. The driving mechanism 4 can achieve precise control of the position of the ammonia fuel pipe 1 through precise mechanical driving technology.

[0044] For example, the transmission mechanism 42 is a gear rack mechanism, the gear is connected to the output shaft of the drive motor 41 and rotates synchronously, the gear is meshed with the rack, the rack is connected to the ammonia fuel pipe 1, and the rack can move along the axial direction of the ammonia fuel pipe 1, thereby realizing the axial movement of the ammonia fuel pipe 1.

[0045] Alternatively, the driving motor 41 is a stepping motor and the output shaft can move along the axial direction of the ammonia fuel pipe 1 , and the output shaft of the stepping motor is connected to the ammonia fuel pipe 1 to enable the ammonia fuel pipe 1 to move along the axial direction of the ammonia fuel pipe 1 .

[0046] In this embodiment, by setting the adjustment action mode of the ammonia fuel pipe 1 to be driven by the drive motor 41, that is, the bearing gear mechanism on the ammonia fuel pipe 1 is connected to the chain of the drive motor 41, and coordinating the combined setting of the drive motor 41, the ammonia fuel pipe 1 can simultaneously realize the axial displacement of itself and the end ammonia fuel pipe 1, thereby changing the distance that the outflow section 12 of the ammonia fuel pipe 1 extends out of the outlet of the swirl burner 100 (the outlet of the flue gas pipe 2 / primary air duct assembly 3), thereby realizing the change of the ammonia fuel spraying position.

[0047] In some embodiments of the present invention, Figure 1 and Figure 2 As shown, on the cross section where the axis of the flue gas pipe 2 is located, the angle A between the outer peripheral wall of the first section 221 and the axis of the ammonia fuel pipe 1 satisfies: 15°≤A≤35°. It can be understood that the angle A between the outer peripheral wall of the first section 221 and the axis of the ammonia fuel pipe 1 can be 15°, 16°, 17°, 18°, 19°, 20°, 21°, 22°, 23°, 24°, 25°, 26°, 27°, 28°, 29°, 30°, 31°, 32°, 33°, 34° or 35°. The angle A between the outer wall of the first section 221 and the axis of the ammonia fuel pipe 1 is not less than 15°, which can ensure the shrinking effect of the primary air channel 31 and the concentration effect of the coal powder airflow; the angle A between the outer wall of the first section 221 and the axis of the ammonia fuel pipe 1 is not greater than 35°, which can prevent the primary air channel 31 from being too small and prevent the coal powder from being blocked on the side of the first section 221 close to the inlet end 13, thereby ensuring the effect of the primary air channel 31 in conveying primary air and coal powder.

[0048] In some embodiments of the present invention, Figure 1 and Figure 2 As shown, on the cross section where the axis of the flue gas pipe 2 is located, the angle between the outer wall of the third section 223 and the axis of the ammonia fuel pipe 1 is B and satisfies: 15°≤B≤35°. It can be understood that the angle B between the outer wall of the third section 223 and the axis of the ammonia fuel pipe 1 can be 15°, 16°, 17°, 18°, 19°, 20°, 21°, 22°, 23°, 24°, 25°, 26°, 27°, 28°, 29°, 30°, 31°, 32°, 33°, 34° or 35°. The angle B between the outer wall of the third section 223 and the axis of the ammonia fuel pipe 1 is not less than 15°, which can ensure that the coal powder in the primary air is separated into thick and thin when passing through the guide refractory mechanism 22; the angle B between the outer wall of the third section 223 and the axis of the ammonia fuel pipe 1 is not greater than 35°, which can ensure the effect of conveying primary air and coal powder in the primary air channel 31.

[0049] In some embodiments of the present invention, Figure 1 and Figure 2 As shown, on the cross section where the axis of the primary air duct assembly 3 is located, the angle between the inner circumferential wall of the bell mouth 32 and the axis of the primary air duct assembly 3 is C and satisfies: 15°≤C≤35°. It can be understood that the angle C between the inner circumferential wall of the bell mouth 32 and the axis of the primary air duct assembly 3 can be 15°, 16°, 17°, 18°, 19°, 20°, 21°, 22°, 23°, 24°, 25°, 26°, 27°, 28°, 29°, 30°, 31°, 32°, 33°, 34° or 35°. The angle C between the inner wall of the bell mouth 32 and the axis of the primary air duct assembly 3 is not less than 15°, which can ensure the effect of the bell mouth 32 on the outward diversion of the primary air, realize the formation of a high oxygen zone at the bell mouth 32, and form a low oxygen combustion area with the ammonia fuel mixed with flue gas on the side of the diversion refractory mechanism 22 close to the outlet end 14; the angle C between the inner wall of the bell mouth 32 and the axis of the primary air duct assembly 3 is not greater than 35°, which can avoid the oxygen content on the inner side of the bell mouth 32 being too low, thereby avoiding affecting the combustion effect of the ammonia fuel.

[0050] In some embodiments of the present invention, Figure 1 and Figure 2As shown, on the cross section where the axis of the ammonia fuel pipe 1 is located, the angle between the peripheral wall of the outflow section 12 and the axis of the outflow section 12 is D and satisfies: 15°≤D≤35°. It can be understood that the angle D between the peripheral wall of the outflow section 12 and the axis of the outflow section 12 can be 15°, 16°, 17°, 18°, 19°, 20°, 21°, 22°, 23°, 24°, 25°, 26°, 27°, 28°, 29°, 30°, 31°, 32°, 33°, 34° or 35°. The angle D between the peripheral wall of the outflow section 12 and the axis of the outflow section 12 is not less than 15°, which can prevent the ammonia fuel from flowing too much to the radial outside of the ammonia fuel pipe 1, prevent the ammonia fuel from mixing with the primary air at the bell mouth 32, avoid a high oxygen content during the combustion of the ammonia fuel, and avoid the generation of more NOx; the angle D between the peripheral wall of the outflow section 12 and the axis of the outflow section 12 is not greater than 35°, which can prevent the ammonia fuel from being too concentrated and avoid affecting the mixing effect of the ammonia fuel and the flue gas.

[0051] In some embodiments of the present invention, Figure 1 and Figure 2 As shown, the axis of the outflow hole 121 is perpendicular to the peripheral wall of the outflow section 12, so that the outflow hole 121 is constructed into a hole structure with a certain incident angle, and the combination of the bell mouth 32 and the guide refractory mechanism 22 of the flue gas pipe 2 forms an oxygen-depleted zone of ammonia gas and flue gas in the middle of the outlet of the swirl burner 100, and an oxygen-rich zone is formed on the periphery, which effectively avoids the ammonia fuel from being drawn into the oxygen-rich zone of coal powder combustion during ammonia combustion, inhibits the oxidation of ammonia fuel, promotes the reduction effect of ammonia fuel on NOx generated by coal powder combustion, reduces the generation of NOx, and ensures the efficiency of ammonia combustion.

[0052] In some embodiments of the present invention, Figure 1 As shown, the flue gas pipe 2 includes a pipe body 23 and a flue gas inlet pipe 24. The pipe body 23 is sleeved on the radially outer side of the ammonia fuel pipe 1 and at least partially penetrates the primary air duct assembly 3. The flue gas inlet pipe 24 is connected to one end of the pipe body 23 close to the inlet end 13 and extends outward along the radial direction of the pipe body 23, so that the inlet of the flue gas entering the flue gas pipe 2 is separated from the inlet of the ammonia fuel entering the ammonia fuel pipe 1, so as to avoid premature mixing of the ammonia fuel with the flue gas and affecting the combustion effect of the ammonia fuel.

[0053] In some embodiments of the present invention, Figure 1As shown, the primary air duct assembly 3 includes a primary pipe 33 and a primary air inlet pipe 34. The primary pipe 33 is sleeved on the radial outside of the flue gas pipe 2. The primary air inlet pipe 34 is connected to one end of the primary pipe 33 close to the inlet end 13 and extends outward along the radial direction of the primary air inlet pipe 34, so that the inlet of the primary air and pulverized coal entering the primary air duct assembly 3 is separated from the inlet of the flue gas entering the flue gas pipe 2 and the inlet of the ammonia fuel entering the ammonia fuel pipe 1, so as to avoid the ammonia fuel from mixing with the flue gas in advance and avoid the primary air and pulverized coal from mixing with the ammonia fuel and the flue gas, so as to avoid affecting the combustion effect of the ammonia fuel and the pulverized coal.

[0054] In some embodiments of the present invention, Figure 1 , Figure 3 and Figure 4 As shown, the flow section 11 includes an inner fuel pipe 111 and an outer sleeve 112. The outer sleeve 112 is sleeved on the outside of the inner fuel pipe 111. The outer sleeve 112 is a fire-resistant pipe, and at least part of the outer sleeve 112 is inserted into the flue gas pipe 2. The outer sleeve 112 is sealed and connected to the flue gas inlet pipe 24, which fully guarantees the sealing and reliability of the ammonia fuel transportation process and avoids leakage during the ammonia fuel transportation process. In addition, the outer sleeve 112 is relatively fire-resistant to avoid damage to the ammonia fuel pipe 1 when the ammonia fuel is burned. The outer sleeve 112 made of refractory material can be used to isolate the heat of the flue gas from being transferred to the ammonia fuel inside the inner fuel pipe 111, thereby enhancing the stability and safety of the ammonia fuel combustion.

[0055] In some embodiments of the present invention, Figure 1 As shown, the swirl burner 100 with ammonia flue gas circulation also includes a secondary air duct assembly 5, which is sleeved on at least part of the outer side of the primary air duct assembly 3 near the outlet end 14 and defines a secondary air channel 53 together with the primary air duct assembly 3 for conveying secondary air. An oxygen-enriched zone of a certain length can be formed in the peripheral area of ​​the outlet end 14 of the primary air duct assembly 3, so that the pulverized coal concentrated in the primary air duct assembly 3 can achieve oxygen-enriched combustion in the peripheral area of ​​the bell mouth 32, fully ensuring the stability of the root of the pulverized coal flame.

[0056] In some embodiments of the present invention, Figure 1As shown, the secondary air duct assembly 5 includes a first tube 51 and a second tube 52. The first tube 51 is sleeved on at least part of the outer side of the primary air duct assembly 3 near the outlet end 14. The first tube 51 and the primary air duct assembly 3 define an inner swirl channel 511. Along the direction from the inlet end 13 to the outlet end 14, an inner bellows 512 and an inner blade 513 are sequentially arranged on one side of the inner swirl channel 511 near the inlet end 13. The inner bellows 512 generates wind, and the inner blade 513 converts the wind generated by the inner bellows 512 into a swirl and continuously transports the inner swirl secondary to the peripheral area of ​​the bell mouth 32. Wind; the second tube 52 is sleeved on at least part of the outer side of the first tube 51 near the outlet end 14, and the second tube 52 and the first tube 51 define an outer swirl channel 521. Along the direction from the inlet end 13 to the outlet end 14, the outer wind box 522 and the outer blade 523 are sequentially arranged on the side of the outer swirl channel 521 near the inlet end 13. The outer wind box 522 generates wind, and the outer blade 523 converts the wind generated by the outer wind box 522 into swirl and continuously delivers the outer swirl secondary wind to the peripheral area of ​​the bell mouth 32. The pulverized coal concentrated in the primary air duct assembly 3 can achieve oxygen-enriched combustion in the peripheral area of ​​the bell mouth 32, fully ensuring the stability of the root of the pulverized coal flame.

[0057] Accordingly, by utilizing the outflow section 12 of the ammonia fuel pipe 1 and the guide refractory structure 22 of the flue gas pipe 2, in conjunction with the end of the flue gas pipe 2 close to the outlet end 14 not exceeding the flow section 11 in the direction from the inlet end 13 to the outlet end 14, and the bell mouth 32 of the primary air duct assembly 3, the ammonia fuel can be accurately delivered into the swirl burner 100 after being diluted by the flue gas, away from the oxygen-rich zone around the outlet end 14 of the swirl burner 100, thereby preventing the ammonia fuel from being sucked into the side of the secondary air duct assembly 5 of the swirl burner 100 close to the outlet end 14, thereby effectively inhibiting the oxidation reaction of ammonia, promoting the thermal decomposition of ammonia, ensuring the combustion efficiency of ammonia while controlling the generation of NOx.

[0058] In this embodiment, one end of the first tube 51 and the second tube 52 close to the outlet end 14 is trumpet-shaped, which can cooperate with the bell mouth 32 of the first air duct assembly to achieve coordination between the secondary air and the coal powder combustion area.

[0059] Other structures and operations of the swirl burner 100 with ammonia-doped flue gas circulation according to the embodiment of the present invention are known to those skilled in the art and will not be described in detail here.

[0060] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0061] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A swirl burner with ammonia-doped flue gas circulation, characterized in that: include: An ammonia fuel pipe, the ammonia fuel pipe comprising a flow section and an outflow section, the axial ends of the flow section are an inlet end and an outlet end respectively, one axial end of the outflow section is connected to the outlet end of the flow section, and the other end is closed, along the direction from the inlet end to the outlet end, the peripheral wall of the outflow section is inclined toward the direction close to the axis of the outflow section, and a plurality of outflow holes are provided on the peripheral wall of the outflow section, and the plurality of outflow holes are sequentially spaced along the circumferential direction of the outflow section; A flue gas pipe, wherein the flue gas pipe is sleeved outside the ammonia fuel pipe and defines a flue gas channel together with the ammonia fuel pipe, and a flow-guiding fire-resistant mechanism is provided on the outer peripheral wall of one end of the flue gas pipe close to the outlet end, and the flow-guiding fire-resistant mechanism extends in a ring shape along the circumferential direction of the flue gas pipe, and along the direction from the inlet end to the outlet end, the flow-guiding fire-resistant mechanism includes a first section, a second section and a third section connected in sequence, the outer diameter of the first section gradually increases, the outer diameter of the second section remains unchanged, and the outer diameter of the third section gradually decreases; A primary air duct assembly, the primary air duct assembly is sleeved outside the flue gas duct and defines a primary air channel together with the flue gas duct for conveying primary air and coal powder, and a bell mouth is provided at one end of the primary air duct assembly close to the outlet end, and the inner diameter of the bell mouth gradually increases along the direction from the inlet end to the outlet end; Wherein, along the direction from the inlet end to the outlet end, the end of the flue gas pipe close to the outlet end does not exceed the flow section.

2. The swirl burner with ammonia-doped flue gas circulation according to claim 1, characterized in that: The ammonia fuel pipe is movable along the axial direction of the flow section, and the swirl burner further comprises: A driving mechanism is provided at one end of the flow section close to the inlet end and is used for driving the ammonia fuel pipe to move along the axial direction of the ammonia fuel pipe.

3. The swirl burner with ammonia-doped flue gas circulation according to claim 2, characterized in that: The driving mechanism comprises: Drive motor; A transmission mechanism is connected to the flow section and the output shaft of the drive motor, and is used to drive the ammonia fuel pipe to move along the axial direction of the ammonia fuel pipe.

4. The swirl burner with ammonia-doped flue gas circulation according to claim 1, characterized in that: On the cross section where the axis of the flue gas pipe is located, the angle between the outer peripheral wall of the first section and the axis of the ammonia fuel pipe is A and satisfies: 15°≤A≤35°; And / or, in the cross section where the axis of the flue gas pipe is located, the angle between the outer peripheral wall of the third section and the axis of the ammonia fuel pipe is B and satisfies: 15°≤B≤35°.

5. The swirl burner with ammonia-doped flue gas circulation according to claim 1, characterized in that: On the cross section where the axis of the primary air duct assembly is located, the angle between the inner peripheral wall of the bell mouth and the axis of the primary air duct assembly is C and satisfies: 15°≤C≤35°.

6. The swirl burner with ammonia-doped flue gas circulation according to claim 1, characterized in that: On the cross section where the axis of the ammonia fuel pipe is located, the angle between the peripheral wall of the outflow section and the axis of the outflow section is D and satisfies: 15°≤D≤35°.

7. The swirl burner with ammonia-doped flue gas circulation according to claim 1, characterized in that: The axis of the outflow hole is perpendicular to the peripheral wall of the outflow section.

8. The swirl burner with ammonia-doped flue gas circulation according to claim 1, characterized in that: The flow section comprises: inner fuel pipe; The outer sleeve is sleeved on the outer side of the inner fuel pipe, the outer sleeve is a fire-resistant pipe, and at least a part of the outer sleeve is passed through the smoke pipe.

9. The swirl burner with ammonia-doped flue gas circulation according to claim 1, characterized in that: Also includes: A secondary air duct assembly is sleeved on at least a portion of the outer side of the primary air duct assembly close to the outlet end and defines a secondary air channel together with the primary air duct assembly for conveying secondary air.

10. The swirl burner with ammonia-doped flue gas circulation according to claim 9, characterized in that: The secondary air duct assembly comprises: A first tube, the first tube is sleeved on at least a portion of the outer side of the primary air duct assembly near the outlet end, the first tube and the primary air duct assembly define an inner vortex channel, and along the direction from the inlet end to the outlet end, an inner bellows and inner blades are sequentially provided on one side of the inner vortex channel near the inlet end; A second tube, wherein the second tube is sleeved on at least part of the outer side of the first tube near the outlet end, the second tube and the first tube define an external vortex channel, and along the direction from the inlet end to the outlet end, an external bellows and external blades are sequentially provided on one side of the external vortex channel near the inlet end.

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