Ammonia-doped flue gas recirculation swirled burner

Abstract

The application discloses a cyclone burner of ammonia-doped flue gas circulation, which 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, and a plurality of outflow holes are arranged on the peripheral wall of the outflow section. A flow guide refractory mechanism is arranged on the outer peripheral wall of one end of the flue gas pipe close to an outlet end. The outer diameter of the first section of the flow guide refractory mechanism gradually increases, the outer diameter of the second section is constant, and the outer diameter of the third section gradually decreases. The primary air pipe assembly is sleeved outside the flue gas pipe and cooperates with the flue gas pipe to define a primary air passage for conveying primary air and coal powder. One end of the primary air pipe assembly close to the outlet end is provided with a bell mouth. In the direction from an inlet end to the outlet end, the one end of the flue gas pipe close to the outlet end does not exceed the flow section. According to the cyclone burner, the reduction effect of ammonia fuel on NOx generated by coal powder combustion can be enhanced, the generation of NOx is reduced, and the environmental protection performance during use of the cyclone burner is improved.

Description

Technical Field

[0001] This invention relates to the field of burner technology, specifically to a swirl burner for ammonia-infused flue gas recirculation. Background Technology

[0002] In existing technologies, ammonia-coal blending as a fuel for power generation in coal-fired power plants can achieve carbon emission reduction in the power system, and this technology is in line with my country's energy situation. However, ammonia blending combustion leads to problems such as high NOx emissions, affecting the environmental friendliness of swirl burners during operation. Summary of the Invention

[0003] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a swirl burner with ammonia-infused flue gas recirculation, which can enhance the reduction effect of ammonia fuel on NOx generated by pulverized coal combustion, reduce NOx formation, and improve the environmental friendliness of the swirl burner during use.

[0004] According to an embodiment of the present invention, a swirl burner for ammonia-blended flue gas circulation includes an ammonia fuel pipe, a flue gas pipe, and a primary air duct assembly. The ammonia fuel pipe includes a flow section and an outlet section. The axial ends of the flow section are an inlet end and an outlet end, respectively. One axial end of the outlet 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 outlet section is inclined towards the direction close to the axis of the outlet section. The peripheral wall of the outlet section is provided with a plurality of outlet holes, which are arranged sequentially at intervals along the circumferential direction of the outlet section. The flue gas pipe is sleeved outside the ammonia fuel pipe and together with the ammonia fuel pipe defines a flue gas passage. The outer peripheral wall of the end of the flue gas pipe near the outlet end is provided with a flow guide. The fire-guiding refractory mechanism extends in a ring shape along the circumferential direction of the flue gas pipe. Along the direction from the inlet end to the outlet end, the flow-guiding refractory 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 constant, and the outer diameter of the third section gradually decreases. The primary air duct assembly is sleeved outside the flue gas pipe and, together with the flue gas pipe, defines a primary air passage for conveying primary air and pulverized coal. A flared opening is provided at the end of the primary air duct assembly near the outlet end, and the inner diameter of the flared opening gradually increases along the direction from the inlet end to the outlet end. The end of the flue gas pipe near the outlet end does not extend beyond the flow section along the direction from the inlet end to the outlet end.

[0005] According to the cyclone burner of the ammonia-doped flue gas cycle, the outer diameter line of the flow guide refractory mechanism gradually increases, and then remains unchanged, and finally gradually decreases, so that the annular cavity in the primary air channel is formed to be first narrowed, then straightened, and then expanded, the primary air channel is formed to be annular and similar to a Laval nozzle shape, the coal powder in the primary air is separated in concentration when passing through the flow guide refractory mechanism, and the rigidity of the primary air can be enhanced; and in 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, the ammonia fuel can be well mixed with the flue gas flowing out of the flue gas pipe when flowing out of the outflow hole, the dilution effect of the flue gas on the ammonia fuel is ensured, a certain oxygen-poor environment is obtained when the ammonia fuel burns, the oxidation of the ammonia fuel is weakened, the reduction effect of the ammonia fuel on the NOx generated by the coal powder combustion is enhanced, the generation of NOx is reduced, the environmental protection performance of the cyclone burner in use is improved, and the operation cost of the cyclone burner is reduced.

[0006] In some embodiments of the present application, the ammonia fuel pipe is movable in the axial direction of the flow section, and the cyclone burner further comprises a driving mechanism arranged at one end of the flow section close to the inlet end and configured to drive the ammonia fuel pipe to move in the axial direction of the ammonia fuel pipe.

[0007] In some embodiments of the present application, the driving mechanism comprises a driving motor and a transmission mechanism, the transmission mechanism is connected with the flow section and the output shaft of the driving motor, and is configured to drive the ammonia fuel pipe to move in the axial direction of the ammonia fuel pipe.

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

[0009] In some embodiments of the present application, the included angle between the inner peripheral wall of the horn mouth and the axis of the primary air pipe assembly on the cross section where the axis of the primary air pipe assembly is located is C and satisfies 15°≤C≤35°.

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

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

[0012] In some embodiments of the present application, the flow section comprises an inner fuel pipe and an outer sleeve pipe, the outer sleeve pipe is sleeved outside the inner fuel pipe, the outer sleeve pipe is a fireproof pipe, at least part of the outer sleeve pipe is penetrated into the flue gas pipe.

[0013] In some embodiments of the present application, the swirl burner of the ammonia-doped flue gas circulation further comprises a secondary air pipe assembly, the secondary air pipe assembly is sleeved outside at least part of the primary air pipe assembly close to the outlet end and cooperates with the primary air pipe assembly to define a secondary air passage for conveying secondary air.

[0014] In some embodiments of the present application, the secondary air pipe assembly comprises a first pipe and a second pipe, the first pipe is sleeved outside at least part of the primary air pipe assembly close to the outlet end, the first pipe and the primary air pipe assembly define an inner swirl passage, a side of the inner swirl passage close to the inlet end is sequentially provided with an inner air box and an inner vane in the direction from the inlet end to the outlet end; the second pipe is sleeved outside at least part of the first pipe close to the outlet end, the second pipe and the first pipe define an outer swirl passage, a side of the outer swirl passage close to the inlet end is sequentially provided with an outer air box and an outer vane in the direction from the inlet end to the outlet end.

[0015] Additional aspects and advantages of the present application will be partially given in the following description, partially will become obvious from the following description, or will be understood by the practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0016] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the accompanying drawings, in which:

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

[0018] Figure 2 is Figure 1 is an enlarged view of A in FIG. 1;

[0019] Figure 3 is Figure 1 is an enlarged view of B in FIG. 1;

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

[0021] REFERENCE NUMERALS:

[0022] 100, swirl burner;

[0023] 1. Ammonia fuel pipe; 11. Flow section; 111. Inner fuel pipe; 112. Outer sleeve pipe; 12. Outflow section; 121. Outflow hole; 13. Inlet end; 14. Outlet end;

[0024] 2. Flue gas pipe; 21. Flue gas passage; 22. Guide fireproof mechanism; 221. First section; 222. Second section; 223. Third section; 23. Pipe body; 24. Flue gas inlet pipe;

[0025] 3. Primary air pipe assembly; 31. Primary air passage; 32. Horn mouth; 33. Primary pipe; 34. Primary air inlet pipe;

[0026] 4. Driving mechanism; 41. Driving motor; 42. Transmission mechanism;

[0027] 5. Secondary air pipe assembly; 51. First pipe; 511. Inner rotational flow passage; 512. Inner bellows; 513. Inner blade; 52. Second pipe; 521. Outer rotational flow passage; 522. Outer bellows; 523. Outer blade; 53. Secondary air passage. DETAILED DESCRIPTION

[0028] Embodiments of the present application are described below in detail with reference to the accompanying drawings, in which like or similar elements are denoted by the same or similar reference signs throughout the drawings. The embodiments described below by reference to the drawings are exemplary only, and are merely intended to explain the present application, and are not to be understood as limiting the present application.

[0029] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0030] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "linking" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0031] Reference will be made to Figures 1-4 The ammonia-doped flue gas circulating swirl burner 100 according to the embodiment of the present application is described.

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

[0033] Specifically, as Figure 1 , Figure 2 and Figure 4 shown, the ammonia fuel pipe 1 can provide a conveying passage for ammonia fuel, the ammonia fuel pipe 1 includes a flow section 11 and an outflow section 12, the flow section 11 has an inlet end 13 and an outlet end 14 at two axial ends respectively, the outflow section 12 is connected with the outlet end 14 of the flow section 11 at one axial end and is closed at the other end, along the direction from the inlet end 13 to the outlet end 14, the peripheral wall of the outflow section 12 is inclined towards the direction close to the axis of the outflow section 12 (as the first direction shown in Figure 1 , a plurality of outflow holes 121 are arranged on the peripheral wall of the outflow section 12 and are sequentially and 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 as a hole structure on the peripheral wall of the outflow section 12 and are sequentially and spaced apart along the circumferential direction of the outflow section 12, which promotes the uniform distribution of ammonia fuel at the outlet of the ammonia fuel pipe 1, and further improves the combustion efficiency and stability of ammonia fuel of the swirl burner 100.

[0035] As Figure 1 and Figure 2 shown, the flue gas pipe 2 is sleeved outside the ammonia fuel pipe 1 and cooperates with the ammonia fuel pipe 1 to define a flue gas passage 21, and the outlet of the flue gas passage 21 cooperates with the circular frustum outflow section 12 to enable the flue gas to be injected straight to the position where the ammonia fuel is mixed, so that the flue gas can sufficiently dilute the ammonia fuel injected from the outflow holes 121.

[0036] As Figure 1 and Figure 2As shown, the primary air pipe assembly 3 is arranged outside the flue gas pipe 2 and cooperates with the flue gas pipe 2 to define a primary air passage 31 for conveying primary air and coal powder. The outer peripheral wall of the end of the flue gas pipe 2 close to the outlet end 14 is provided with a flow guide refractory mechanism 22. The flow guide refractory mechanism 22 extends in the circumferential direction of the flue gas pipe 2 to form an annular shape. In the direction from the inlet end 13 to the outlet end 14, the flow guide refractory mechanism 22 includes a first segment 221, a second segment 222 and a third segment 223 connected in sequence. The outer diameter of the first segment 221 gradually increases, the outer diameter of the second segment 222 remains unchanged, and the outer diameter of the third segment 223 gradually decreases. The primary air passage 31 forms an annular cavity that first narrows, then straightens, and then expands. The primary air pipe assembly 3 and the part of the flue gas pipe 2 provided with the flow guide refractory mechanism 22 form a shape similar to a Laval nozzle, so that the coal powder conveyed by the primary air can be concentrated at the first segment 221, thereby increasing the coal powder concentration of the part of the primary air passage 31 close to the flow guide refractory mechanism 22. After passing through the second segment 222, the coal powder flows stably, thereby improving the stability of coal powder conveying. The subsequent expansion utilizes the inertia of the coal powder to separate the wind and powder, thereby improving the rigidity of the primary air, and further improving the combustion stability of the cyclone burner 100 in a low load operating state, ensuring sufficient combustion of the coal powder, and improving the combustion efficiency.

[0037] As shown in FIGS. 1, 2 and 3, Figure 1 and Figure 2 the inner diameter of the second segment 222 remains constant, which further stabilizes the transmission state of the concentrated material, avoids turbulent flow in the primary air pipe passage, and ensures the stability of coal powder material transmission.

[0038] The end of the primary air pipe assembly 3 close to the outlet end 14 is provided with a bell mouth 32. In the direction from the inlet end 13 to the outlet end 14, the inner diameter of the bell mouth 32 gradually increases. The primary air close to the bell mouth 32 can be conveyed to the outer peripheral area of the bell mouth 32 and form a high oxygen area at the bell mouth 32, which facilitates the sufficient combustion of coal powder in the high oxygen area. The side of the flow guide refractory mechanism 22 close to the outlet end 14 forms a low oxygen combustion area with the ammonia fuel mixed with flue gas. 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 coal powder combustion, reducing the generation of NOx, improving the environmental protection during the use of the coal-fired boiler, reducing the operation cost of the coal-fired boiler, and ensuring the efficiency of the ammonia combustion.

[0039] In 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 of the flow 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 the ammonia fuel can obtain a certain lean oxygen environment during combustion, weaken the oxidation effect of the ammonia fuel, and enhance the reduction characteristics of the ammonia fuel, thereby reducing the generation of NOx.

[0040] According to the ammonia-doped flue gas circulating cyclone burner 100 of the embodiment of the present application, by arranging the flow guide refractory mechanism 22 on the outer peripheral wall of the end of the flue gas pipe 2 close to the outlet end 14, and gradually increasing the outer diameter line of the flow guide refractory mechanism 22, and then keeping unchanged, and finally gradually decreasing, an annular cavity is formed in the primary air passage 31, which is first narrowed, then straightened, and then expanded, so that the primary air passage 31 is partially formed in the shape of an annular Laval nozzle, so that the coal powder in the primary air is separated in concentration when passing through the flow guide refractory mechanism 22, and the rigidity of the primary air can be enhanced at the same time. In 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 when the ammonia fuel flows out of the flow-out 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-poor environment is obtained when the ammonia fuel is burned, weakening the oxidation of the ammonia fuel and enhancing 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 performance of the cyclone burner 100 during use, and reducing the operating cost of the cyclone burner 100.

[0041] In the embodiment, the flow guide refractory mechanism 22 is a refractory material piece, which can enhance the refractory performance of the structure of the primary air close to the outlet end 14, and enhance the stability and safety of the ammonia fuel combustion.

[0042] In some embodiments of the present application, as shown in Figure 1 and Figure 3 , the ammonia fuel pipe 1 is movable in the axial direction of the flow section 11, and the cyclone burner 100 further comprises a driving mechanism 4 arranged at the end of the flow section 11 close to the inlet end 13, for driving the ammonia fuel pipe 1 to move in the axial direction of the ammonia fuel pipe 1. The driving mechanism 4 can push or pull the ammonia fuel pipe 1 in the axial direction of the flow section 11, so as to change the specific position of the flow-out 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 horn mouth 32 of the primary air pipe assembly 3, which can meet the ammonia-doped combustion under different combustion conditions, improve the adaptability and application range of the cyclone burner 100, greatly improve the flexibility of the cyclone burner 100 in fuel mixing and combustion control, ensure the uniformity of the ammonia-doped combustion of the cyclone burner 100 under different combustion loads, improve the reliability and stability of the ammonia-doped combustion of the cyclone burner 100, and also provide the user with the possibility of adjusting the combustion parameters according to actual needs.

[0043] Further, as shown in Figure 1 and Figure 3As shown, the driving mechanism 4 comprises a driving motor 41 and a transmission mechanism 42, the transmission mechanism 42 is connected with the flow section 11 and the output shaft of the driving motor 41, for driving the ammonia fuel pipe 1 to move along the axial direction of the ammonia fuel pipe 1, which can stably and reliably drive the ammonia fuel pipe 1 to move along the axial direction of the ammonia fuel pipe 1, and the driving mechanism 4 can realize the accurate control of the position of the ammonia fuel pipe 1 through the precise mechanical driving technology.

[0044] For example, the transmission mechanism 42 is a gear and rack mechanism, the gear is connected with the output shaft of the driving motor 41 and rotates synchronously, the gear is engaged with the rack, the rack is connected with the ammonia fuel pipe 1, and the rack can move along the axial direction of the ammonia fuel pipe 1, so as to realize the movement of the ammonia fuel pipe 1 along the axial direction 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, the output shaft of the stepping motor is connected with the ammonia fuel pipe 1, so as to realize the movement of the ammonia fuel pipe 1 along the axial direction of the ammonia fuel pipe 1.

[0046] In the embodiment, the adjustment action mode of the ammonia fuel pipe 1 is set to be driven by the driving motor 41, that is, the bearing gear mechanism on the ammonia fuel pipe 1 is connected with the chain of the driving motor 41, and the combined setting of the adjustment driving motor 41 is matched, so that the ammonia fuel pipe 1 can realize the axial displacement of itself and the end of the ammonia fuel pipe 1 at the same time, thereby changing the distance of the flow-out section 12 of the ammonia fuel pipe 1 extending out of the outlet of the cyclone combustor 100 (the outlet of the flue gas pipe 2 / primary air pipe assembly 3), and realizing the change of the ammonia fuel injection position.

[0047] In some embodiments of the present application, as shown in Figure 1 and Figure 2 As shown in the cross section where the axis of the flue gas pipe 2 is located, the included angle between the outer peripheral wall of the first section 221 and the axis of the ammonia fuel pipe 1 is A and satisfies: 15°≤A≤35°. It can be understood that the included 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 included angle A between the outer peripheral wall of the first section 221 and the axis of the ammonia fuel pipe 1 is not less than 15°, which can ensure the narrowing effect of the primary air passage 31 and the concentration effect of the pulverized coal flow; the included angle A between the outer peripheral wall of the first section 221 and the axis of the ammonia fuel pipe 1 is not greater than 35°, which can avoid that the primary air passage 31 is too small and avoid that the pulverized coal is blocked on one side of the first section 221 close to the inlet end 13, and ensure the effect of conveying the primary air and the pulverized coal in the primary air passage 31.

[0048] In some embodiments of the present application, as shown in Figure 1 andFigure 2 As shown in the drawings, the angle between the outer peripheral wall of the third section 223 and the axis of the ammonia fuel pipe 1 is B and satisfies: 15°≤B≤35° in the cross section where the axis of the flue gas pipe 2 is located. It can be understood that the angle B between the outer peripheral 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 peripheral wall of the third section 223 and the axis of the ammonia fuel pipe 1 is not less than 15°, which can ensure the concentration separation of the pulverized coal in the primary air when passing through the flow guide refractory structure 22; the angle B between the outer peripheral 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 the primary air and the pulverized coal in the primary air channel 31.

[0049] In some embodiments of the present application, as shown in Figure 1 and Figure 2 As shown in the drawings, the angle between the inner peripheral wall of the horn mouth 32 and the axis of the primary air pipe assembly 3 is C and satisfies: 15°≤C≤35° in the cross section where the axis of the primary air pipe assembly 3 is located. It can be understood that the angle C between the inner peripheral wall of the horn mouth 32 and the axis of the primary air pipe 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 peripheral wall of the horn mouth 32 and the axis of the primary air pipe assembly 3 is not less than 15°, which can ensure the effect of outward flow guiding of the primary air by the horn mouth 32, so as to form a high-oxygen area at the horn mouth 32 and form a low-oxygen combustion area of the ammonia fuel mixed with the flue gas on the side of the flow guide refractory structure 22 close to the outlet end 14; the angle C between the inner peripheral wall of the horn mouth 32 and the axis of the primary air pipe assembly 3 is not greater than 35°, which can avoid the oxygen content on the inner side of the horn mouth 32 being too low, so as to avoid affecting the combustion effect of the ammonia fuel.

[0050] In some embodiments of the present application, as shown in Figure 1 and Figure 2As shown, 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° in the cross section where the axis of the ammonia fuel pipe 1 is located. 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 avoid that the ammonia fuel flows too much to the radial outside of the ammonia fuel pipe 1, avoid that the ammonia fuel mixes with the primary air at the bell mouth 32, avoid that the oxygen content is high when the ammonia fuel burns, and avoid that more NOx is generated. The angle D between the peripheral wall of the outflow section 12 and the axis of the outflow section 12 is not more than 35°, which avoids that the ammonia fuel is too concentrated and avoids that the mixing effect of the ammonia fuel and the flue gas is affected.

[0051] In some embodiments of the present application, as shown in 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 configured as a hole structure with a certain incident angle, which is matched with the combination of the bell mouth 32 and the flow guide refractory mechanism 22 of the flue gas pipe 2, so that the middle part of the outlet of the cyclone burner 100 forms a mixed ammonia gas and flue gas poor oxygen zone, and the outer periphery forms an oxygen-rich zone, effectively avoiding that the ammonia fuel is rolled into the oxygen-rich zone of the pulverized coal combustion during the ammonia-doped combustion, inhibiting the oxidation of the ammonia fuel, promoting the reduction effect of the ammonia fuel on the NOx generated by the pulverized coal combustion, reducing the generation of NOx, and ensuring the efficiency of the ammonia-doped combustion.

[0052] In some embodiments of the present application, as shown in 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 radial outside of the ammonia fuel pipe 1 and at least partially penetrates into the primary air pipe assembly 3, and the flue gas inlet pipe 24 is in communication with 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 entrance of the flue gas into the flue gas pipe 2 is separated from the entrance of the ammonia fuel into the ammonia fuel pipe 1, avoiding that the ammonia fuel is mixed with the flue gas in advance, and avoiding that the combustion effect of the ammonia fuel is affected.

[0053] In some embodiments of the present application, as shown in Figure 1As shown, the primary air pipe assembly 3 includes a primary pipe 33 and a primary air inlet pipe 34, the primary pipe 33 is sleeved on the radial outer side of the flue gas pipe 2, and the primary air inlet pipe 34 is in communication with 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 the pulverized coal into the primary air pipe assembly 3 is separated from the inlet of the flue gas into the flue gas pipe 2 and the inlet of the ammonia fuel into the ammonia fuel pipe 1, avoiding the ammonia fuel from being mixed with the flue gas in advance and avoiding the primary air and the pulverized coal from being mixed with the ammonia fuel and the flue gas, and avoiding affecting the combustion effect of the ammonia fuel and the pulverized coal.

[0054] In some embodiments of the present application, as shown in Figure 1 , Figure 3 and Figure 4 , the flow section 11 includes an inner fuel pipe 111 and an outer sleeve pipe 112, the outer sleeve pipe 112 is sleeved on the outer side of the inner fuel pipe 111, the outer sleeve pipe 112 is a refractory pipe, and at least part of the outer sleeve pipe 112 is arranged in the flue gas pipe 2. The outer sleeve pipe 112 is in sealed connection with the flue gas inlet pipe 24, which fully ensures the sealing and reliability of the ammonia fuel conveying process and avoids leakage during the ammonia fuel conveying process. Moreover, the outer sleeve pipe 112 is relatively refractory, which avoids damage to the ammonia fuel pipe 1 during ammonia fuel combustion. The refractory outer sleeve pipe 112 can be used to isolate the heat transfer of the flue gas to the ammonia fuel inside the inner fuel pipe 111, thereby enhancing the stability and safety of ammonia fuel combustion.

[0055] In some embodiments of the present application, as shown in Figure 1 , the swirling burner 100 of the ammonia-doped flue gas cycle further includes a secondary air pipe assembly 5, the secondary air pipe assembly 5 is sleeved on at least part of the outer side of the primary air pipe assembly 3 close to the outlet end 14 and cooperates with the primary air pipe assembly 3 to define a secondary air passage 53 for conveying secondary air. A certain length of oxygen-enriched zone can be formed in the peripheral area of the outlet end 14 of the primary air pipe assembly 3, so that the pulverized coal concentrated in the primary air pipe assembly 3 can realize oxygen-enriched combustion in the peripheral area of the horn mouth 32, thereby fully ensuring the stability of the coal flame root.

[0056] In some embodiments of the present application, as shown in Figure 1As shown, the secondary air pipe assembly 5 includes a first pipe 51 and a second pipe 52. The first pipe 51 is sleeved on the outside of at least part of the primary air pipe assembly 3 near the outlet end 14, and the first pipe 51 and the primary air pipe assembly 3 define an inner rotational flow channel 511. In the direction from the inlet end 13 to the outlet end 14, the inner rotational flow channel 511 is provided with an inner air bellow 512 and an inner blade 513 in sequence on the side near the inlet end 13. The inner air bellow 512 generates air, and the inner blade 513 converts the air generated by the inner air bellow 512 into rotational flow and continuously delivers the inner rotational flow secondary air to the outer peripheral area of the bell mouth 32. The second pipe 52 is sleeved on the outside of at least part of the first pipe 51 near the outlet end 14, and the second pipe 52 and the first pipe 51 define an outer rotational flow channel 521. In the direction from the inlet end 13 to the outlet end 14, the outer rotational flow channel 521 is provided with an outer air bellow 522 and an outer blade 523 in sequence on the side near the inlet end 13. The outer air bellow 522 generates air, and the outer blade 523 converts the air generated by the outer air bellow 522 into rotational flow and continuously delivers the outer rotational flow secondary air to the outer peripheral area of the bell mouth 32. Thus, the pulverized coal condensed in the primary air pipe assembly 3 can be subjected to oxygen-rich combustion in the outer peripheral area of the bell mouth 32, thereby fully ensuring the stability of the pulverized coal flame root.

[0057] Correspondingly, by using the outflow section 12 of the ammonia fuel pipe 1 and the flow guide refractory mechanism 22 of the flue gas pipe 2, in combination with the arrangement that the end of the flue gas pipe 2 near the outlet end 14 does not exceed 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 pipe assembly 3, the ammonia fuel can be accurately sent into the rotational flow burner 100 after being diluted by the flue gas, away from the oxygen-rich area outside the peripheral area of the outlet end 14 of the rotational flow burner 100, thereby avoiding the ammonia fuel from being sucked to the side near the outlet end 14 of the secondary air pipe assembly 5 of the rotational flow burner 100, effectively inhibiting the oxidation reaction of ammonia, promoting the pyrolysis of ammonia, ensuring the ammonia combustion efficiency while controlling the generation of NOx.

[0058] In the present embodiment, the end of the first pipe 51 and the second pipe 52 near the outlet end 14 is bell-shaped, which can be combined with the bell mouth 32 of the first air pipe assembly to realize the cooperation of the secondary air and the pulverized coal combustion area.

[0059] The other configurations and operations of the ammonia-doped flue gas circulating rotational flow burner 100 according to the embodiment of the present application are known to those skilled in the art, and will not be described in detail here.

[0060] In the description of the specification, reference to "one embodiment", "some embodiments", "an exemplary embodiment", "an example", "a specific example", or "some examples" means that a particular feature, structure, material, or characteristic being described is included in at least one embodiment or example of the application. The appearances of the phrases "in one embodiment", "in some embodiments", "in an exemplary embodiment", "an example", "a specific example", or "some examples" in various places in the specification are not necessarily referring to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0061] Although embodiments of the application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and alterations can be made hereto without departing from the principles and the scope of the application, which is defined by the claims and their equivalents.

Claims

1. A cyclone burner for ammonia-doped flue gas recirculation, characterized in that The application relates to a cyclone combustor. The cyclone combustor 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 flow section has an inlet end and an outlet end. The outflow section is connected to the outlet end of the flow section.

2. The ammonia-doped flue gas recirculation swirl burner of claim 1, wherein, The outflow section is closed at one end. The circumferential wall of the outflow section is inclined towards the axis of the outflow section.

3. The ammonia-doped flue gas recirculation swirl burner of claim 2, wherein, The circumferential wall of the outflow section is provided with a plurality of outflow holes. The outflow holes are arranged along the circumferential direction of the outflow section. The flue gas pipe is arranged outside the ammonia fuel pipe and cooperates with the ammonia fuel pipe to define a flue gas passage.

4. The ammonia-doped flue gas recirculation swirl burner of claim 1, wherein, The outer circumferential wall of the flue gas pipe near the outlet end is provided with a flow guide refractory structure. The flow guide refractory structure extends along the circumferential direction of the flue gas pipe.

5. The ammonia-doped flue gas recirculation swirl burner of claim 1, wherein, The flow guide refractory structure comprises a first section, a second section and a third section.

6. The ammonia-doped flue gas recirculation swirl burner of claim 1, wherein, The outer diameter of the first section gradually increases.

7. The ammonia-doped flue gas recirculation, swirl burner of claim 1, wherein, The outer diameter of the second section is constant.

8. The ammonia-doped flue gas recirculation swirl burner of claim 1, wherein, The outer diameter of the third section gradually decreases. The primary air pipe assembly is arranged outside the flue gas pipe and cooperates with the flue gas pipe to define a primary air passage. The primary air pipe assembly is provided with a bell mouth near the outlet end.

9. The ammonia-doped flue gas recirculation swirl burner of claim 1, wherein, The inner diameter of the bell mouth gradually increases. The end of the flue gas pipe near the outlet end does not exceed the flow section. The ammonia fuel pipe is movable along the axial direction of the flow section. The cyclone combustor further comprises a driving mechanism arranged near the inlet end of the flow section. The driving mechanism drives the ammonia fuel pipe to move along the axial direction of the ammonia fuel pipe. The driving mechanism comprises a driving motor and a transmission mechanism. The transmission mechanism is connected to the flow section and the output shaft of the driving motor. The transmission mechanism drives the ammonia fuel pipe to move along the axial direction of the ammonia fuel pipe. The angle between the outer circumferential wall of the first section and the axis of the ammonia fuel pipe is A. 15 DEG <= A <= 35 DEG. The angle between the outer circumferential wall of the third section and the axis of the ammonia fuel pipe is B. 15 DEG <= B <= 35 DEG. The angle between the inner circumferential wall of the bell mouth and the axis of the primary air pipe assembly is C. 15 DEG <= C <= 35 DEG. The angle between the circumferential wall of the outflow section and the axis of the outflow section is D. 15 DEG <= D <= 35 DEG. The axis of the outflow hole is perpendicular to the circumferential wall of the outflow section. The flow section comprises an inner fuel pipe and an outer sleeve pipe. The outer sleeve pipe is a refractory pipe. At least part of the outer sleeve pipe is arranged in the flue gas pipe. The cyclone combustor further comprises a sealing mechanism. A secondary air pipe assembly is sleeved outside at least part of the primary air pipe assembly near the outlet end and cooperates with the primary air pipe assembly to define a secondary air passage for conveying secondary air.

10. The ammonia-doped flue gas circulating cyclone burner of claim 9, wherein, The secondary air pipe assembly comprises: A first pipe is sleeved outside at least part of the primary air pipe assembly near the outlet end, and the first pipe and the primary air pipe assembly define an inner vortex passage, which is provided with an inner air box and an inner blade in sequence near the inlet end in the direction from the inlet end to the outlet end; A second pipe is sleeved outside at least part of the first pipe near the outlet end, and the second pipe and the first pipe define an outer vortex passage, which is provided with an outer air box and an outer blade in sequence near the inlet end in the direction from the inlet end to the outlet end.

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