Ammonia oil dual-fuel burner for marine boiler

Abstract

The utility model discloses an ammonia oil dual-fuel burner for a marine boiler. The ammonia oil dual-fuel burner structurally and sequentially comprises a steam pipe, a fuel oil gun, a fuel oil atomizing nozzle, a primary air conical pipe, a swirler, an annular ammonia gas spray gun air chamber, an outlet conical barrel and a burner shell which are coaxially arranged from the center to the outside. Ammonia gas fuel enters the ammonia gas collecting chamber through an ammonia gas inlet, and the annular ammonia gas spray gun gas chamber is communicated with the ammonia gas collecting chamber through an ammonia gas pipe. Ammonia and heavy oil serve as main fuel, heavy oil fuel atomized by the center fuel oil gun is ignited through the light diesel oil ignition gun, and stable heavy oil combustion flames are formed in the center of the combustor. After the heavy oil fuel atomized by the central fuel gun is ignited, the light diesel oil ignition gun stops working, and ammonia gas sprayed out of a first-stage ammonia gas spraying hole and a second-stage ammonia gas spraying hole outside the swirler is ignited through heavy oil flames; through ammonia fuel staged combustion and combustion-supporting air staged combustion, stable low-carbon low-nitrogen combustion of ammonia gas and heavy oil in a boiler hearth can be achieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of thermal energy engineering, and relates to a marine ammonia-oil dual-fuel burner for a marine clean ammonia fuel boiler. Background Art

[0002] Ammonia (NH3) can be synthesized by an electrochemical method, which can realize large-scale storage of renewable energy and zero carbon emissions of ammonia throughout its life cycle. Compared with hydrogen, ammonia has a large energy volume density, significant energy storage effect, and is easy to liquefy, store and transport. Its advantages in the renewable energy system are becoming increasingly obvious, making it a strong candidate for alternative fuels.

[0003] As a zero-carbon fuel, ammonia can be directly used as boiler fuel. Compared with traditional fossil fuels, it can significantly reduce CO2 emissions and provide a technical route for large-scale CO2 emission reduction of boilers. However, there are two main technical problems in ammonia combustion: (1) The combustion characteristics of NH3 are poor, the ignition temperature is high, the flame propagation speed is slow, and the flammable limit range is narrow, resulting in problems such as whether NH3 can be stably ignited and completely burned; (2) The NH3 molecule contains nitrogen atoms. If the combustion process is not properly controlled, a large amount of fuel-type NOx (nitrogen oxides) is easily generated, resulting in a high NOx emission problem in the combustion flue gas.

[0004] At present, ammonia fuel has been practically applied to marine main engines. In 2023, WinGD and Samsung Heavy Industries cooperated to develop an ammonia fuel engine. However, there are few ammonia burners for marine boilers, and there is still room for further exploration in terms of reliable ignition, stable combustion of ammonia in marine ammonia boilers, and reduction of NOx emissions. Although ammonia fuel boilers have not been used in the ammonia fuel ships that have been launched so far, with the development of technology and the strictness of carbon reduction regulations, in order to achieve "zero-carbon" operation throughout the life cycle of ships, the popularization of marine ammonia fuel boilers in ammonia fuel ships has become inevitable.

[0005] Therefore, in order to achieve the carbon reduction goal of the shipping industry and the comprehensive utilization of zero-carbon ammonia energy, it is necessary to develop a new type of ammonia-oil dual-fuel burner for marine ammonia fuel boilers to solve the problems of ignition, stable combustion, and high NOx emissions during ammonia combustion while achieving "low-carbon combustion". Summary of the Utility Model

[0006] The technical problem to be solved by the utility model is to provide an ammonia-oil dual-fuel burner for a marine boiler. Through four-stage air staging and two-stage fuel staging, a stable central flame is formed by using fuel oil, and the ammonia gas injected into the periphery of the center of the burner is ignited and burned, so that the ammonia gas can be reliably ignited, stably burned, and have low NOx emissions. The equipment has a simple and compact structure and is convenient for installation and use.

[0007] The technical solution adopted by the utility model is as follows: A marine boiler ammonia-oil dual-fuel burner mainly consists of a fuel atomizing nozzle, a swirler, the inner wall of an annular ammonia gas gun, a primary ammonia gas injection hole, a secondary ammonia gas injection hole, an outlet conical cylinder, a flame observation hole, an ignition gun installation hole, a flame detector installation hole, a primary air conical tube, a combustion-supporting air inlet, a burner housing, a steam inlet, a fuel inlet, an ammonia gas inlet, an annular ammonia gas gun air chamber, an ammonia gas pipe, an ammonia gas collecting chamber, a fuel gun, a steam pipe, etc. The inner wall of the annular ammonia gas gun, the primary air conical tube, the annular ammonia gas gun air chamber, the fuel gun, and the steam pipe are coaxial with the burner housing and are placed in the inner cavity of the burner housing; the annular ammonia gas gun air chamber is coaxially provided with a fuel atomizing nozzle, a primary air conical tube, and a swirler. The fuel atomizing nozzle, the primary ammonia gas injection hole, and the secondary ammonia gas injection hole are arranged at the outlet end of the swirler. The fuel atomizing nozzle is located at the axis of the swirler, and the primary air conical tube is located between the fuel atomizing nozzle and the swirler; there is a certain gap between the outer wall of the fuel atomizing nozzle and the inner wall of the primary air conical tube to form a direct-current primary air sandwich outlet; a secondary swirling air is formed through the axial blades of the swirler; there is a certain gap between the outer wall of the swirler and the inner wall of the annular ammonia gas gun to form a direct-current tertiary air sandwich outlet; there is a certain gap between the outer wall of the annular ammonia gas gun air chamber and the outlet conical cylinder to form a direct-current quaternary air sandwich outlet. A number of primary ammonia gas injection holes and secondary ammonia gas injection holes are evenly distributed circumferentially outside the swirler. The primary ammonia gas injection holes face the axial direction of the swirler, and the secondary ammonia gas injection holes face the radial direction of the swirler.

[0008] A primary air conical tube and a swirler are provided at the outlet of the fuel atomizing nozzle. A conical direct-current intersecting primary air is formed between the inner wall of the primary air conical tube and the outside of the fuel atomizing nozzle. This primary air is beneficial to reducing the erosion of the high-temperature flue gas flowing back to the center of the atomizing nozzle on the fuel atomizing nozzle and preventing the fuel in the fuel injection holes of the fuel atomizing nozzle from being carbonized at high temperature and blocked.

[0009] The fuel outlet of the fuel atomizing nozzle is located at the position of the outlet end face of the swirler. The fuel atomizing nozzle is installed on the outlet end face of the fuel gun and the steam pipe. The structure of the fuel atomizing nozzle is a Y-type steam atomizing nozzle structure. A number of fuel injection holes are evenly distributed on the circumference of the fuel atomizing nozzle. The included angle between the fuel injection holes and the axis of the burner housing is 45° - 60°.

[0010] The fuel gun, the steam pipe, and the fuel atomizing nozzle are coaxial. The steam pipe is nested inside the fuel gun. The fuel atomizing nozzle is respectively connected to the fuel gun and the steam pipe.

[0011] The annular ammonia gas gun air chamber is located between the inner wall of the outlet conical cylinder and the outer wall of the swirler. The surface of the annular ammonia gas gun air chamber is provided with a primary ammonia gas injection hole and a secondary ammonia gas injection hole; the primary ammonia gas injection hole and the secondary ammonia gas injection hole are located at the position between the outlet end face of the swirler and the outlet end face of the outlet conical cylinder.

[0012] The outlet of the primary ammonia injection holes of the annular ammonia spray gun air chamber extends beyond the outlet end of the swirler, and the extension distance is 10 - 13 cm; the outlet of the inner wall of the annular ammonia spray gun is conical, and its cone angle is 23° - 26°.

[0013] The outlet of the outlet conical cylinder extends beyond the outlet end of the primary ammonia injection holes, and the extension distance is 16 - 18 cm; the outlet of the outlet conical cylinder is conical, and its cone angle is smaller than the cone angle of the outlet of the inner wall of the annular ammonia spray gun, and its cone angle is 10° - 13°.

[0014] The swirler is of an axial swirl structure, the angle of its swirl vanes is 45° - 55°, and the number of vanes is 18 - 24.

[0015] The burner housing is provided with a steam inlet, a fuel inlet, an ammonia inlet, an ammonia gas collecting chamber, and a combustion-supporting air inlet; the combustion-supporting air inlet is communicated with the burner housing; the steam inlet is communicated with the steam pipe inside the burner housing; the fuel inlet is communicated with the fuel gun inside the burner housing; the ammonia inlet is communicated with the ammonia gas collecting chamber; the ammonia gas collecting chamber is communicated with the annular ammonia spray gun air chamber through ammonia pipes, and the number of ammonia pipes is 8 - 10.

[0016] Ignition gun mounting holes, flame observation holes, and flame detector mounting holes are reserved on the swirler and the burner housing. The ignition gun is in the form of a high-voltage electrode ignition gun using light diesel fuel. First, the fuel sprayed out by the fuel atomizing nozzle is ignited. When the fuel sprayed out by the fuel atomizing nozzle is ignited, the ignition gun goes out, and then the ammonia gas sprayed out from the primary ammonia injection holes and the secondary ammonia injection holes outside the swirler is ignited by the fuel flame; through the stable fuel flame formed in the center of the swirler, it is ensured that the ammonia gas outside the swirler can be ignited by the fuel flame and stably burned.

[0017] The number of the primary ammonia injection holes is 180 - 200, and they are divided into 10 groups and evenly distributed on the end face of the annular ammonia spray gun air chamber; the number of the secondary ammonia injection holes is 270 - 300, and they are divided into 10 groups and evenly distributed on the outer side wall surface of the annular ammonia spray gun air chamber.

[0018] Compared with the prior art, the utility model has at least the following beneficial effects:

[0019] (1) This burner uses ammonia gas and heavy oil as the main fuels, and at the same time is assisted by a small amount of light diesel. The heavy oil fuel atomized by the central fuel gun is ignited by the light diesel ignition gun, and a stable heavy oil combustion flame is formed in the center of the burner; when the heavy oil fuel atomized by the central fuel gun is ignited, the light diesel ignition gun stops working, and then the ammonia gas sprayed out from the primary ammonia injection holes and the secondary ammonia injection holes outside the swirler is ignited by the heavy oil flame; through staged combustion of ammonia fuel and staged combustion of combustion-supporting air, stable low-carbon and low-nitrogen combustion of ammonia gas and heavy oil in the boiler furnace can be achieved.

[0020] (2) Both the ammonia fuel and the combustion-supporting air are fed into the boiler furnace in a staged manner. Among them, the ammonia fuel is fed in a two-stage manner, and the combustion-supporting air is fed in a four-stage manner; through the swirler, the high-temperature flue gas near the fuel atomizing nozzle is refluxed, turbulently mixed with the heavy oil droplets ejected from the fuel atomizing nozzle, and a stable heavy oil combustion flame is formed at the center of the burner; by means of the three-way direct current air, the turbulence intensity of the secondary swirling air is weakened, which helps to ignite the ammonia ejected from the primary ammonia nozzle at the periphery of the central fuel flame.

[0021] (3) A primary air conical tube and a swirler are provided at the outlet of the fuel atomizing nozzle. A conical direct current intersecting primary air is formed between the inner wall of the primary air conical tube and the outside of the fuel atomizing nozzle. This primary air is beneficial to reducing the erosion of the high-temperature flue gas refluxing at the center of the atomizing nozzle on the fuel atomizing nozzle and preventing the fuel in the fuel injection holes of the fuel atomizing nozzle from being carbonized at high temperature and blocked.

[0022] (4) The cone angle of the outlet conical tube is smaller than the outlet cone angle of the inner wall of the annular ammonia spray gun, which moderately extends the flame length, prevents the flame from concentrating, and is beneficial to suppressing the formation of thermal type nitrogen oxides; the ammonia ejected through the secondary ammonia nozzle is mixed with the four-way air and forms a fuel-rich outer region, enters the reduction region of the outer flame of the burner, and through the reduction reaction of NH3 with the generated NOx in a high-temperature and oxygen-deficient environment, N2 and H2O are generated, further achieving the purpose of suppressing the generation of NOx. Description of the Drawings

[0023] Figure 1 It is a structural diagram of a marine boiler ammonia-oil dual-fuel burner;

[0024] Figure 2 It is an oblique view of a marine boiler ammonia-oil dual-fuel burner;

[0025] Figure 3 It is a partial cross-sectional view of a marine boiler ammonia-oil dual-fuel burner;

[0026] Figure 4 It is a cross-sectional view of a marine boiler ammonia-oil dual-fuel burner.

[0027] Among them, 1 is the fuel atomizing nozzle, 2 is the swirler, 3 is the inner wall of the annular ammonia spray gun, 4 is the primary ammonia nozzle, 5 is the outlet conical tube, 6 is the flame observation hole, 7 is the ignition gun installation hole, 8 is the flame detector installation hole, 9 is the primary air conical tube, 10 is the primary air interlayer, 11 is the three-way air interlayer, 12 is the four-way air interlayer, 13 is the combustion-supporting air inlet, 14 is the burner shell, 15 is the steam inlet, 16 is the fuel inlet, 17 is the ammonia inlet, 18 is the secondary ammonia nozzle, 19 is the annular ammonia spray gun air chamber, 20 is the ammonia pipe, 21 is the ammonia gas collecting chamber. Detailed Implementation Manner

[0028] The present invention will be further described in detail below with reference to the drawings.

[0029] As Figures 1 to 4 shown, the marine boiler ammonia-oil dual-fuel burner of this embodiment includes, in sequence from the center outwards, a steam pipe 23, an oil gun 22, an oil atomizing nozzle 1, a primary air conical tube 9, a swirler 2, an annular ammonia gas gun chamber 19, an outlet conical tube 5, and a burner housing 14 that are coaxially arranged.

[0030] Ammonia fuel enters the ammonia gas collecting chamber 21 through the ammonia gas inlet 17. The annular ammonia gas gun chamber 19 is communicated with the ammonia gas collecting chamber 21 through the ammonia gas pipe 20, and the two-stage classification of ammonia fuel is realized through ammonia gas spray holes designed at different radial positions.

[0031] Heavy oil fuel enters the oil gun 22 through the oil inlet 16, and atomizing medium steam enters the steam pipe 23 through the steam inlet 15. The oil gun 22, the steam pipe 23, and the oil atomizing nozzle 1 are coaxial. The steam pipe 23 is nested inside the oil gun 22, and the oil atomizing nozzle 1 is communicated with the oil gun 22 and the steam pipe 23 respectively, realizing the staged atomization of heavy oil fuel.

[0032] The fuel outlet of the oil atomizing nozzle 1 is located at the outlet end face position of the swirler 2. The structure of the oil atomizing nozzle 1 is a Y-type steam atomizing nozzle structure. 8 to 12 fuel spray holes are evenly distributed on the circumference of the oil atomizing nozzle 1, and the included angle between the fuel spray holes and the axis of the burner housing 14 is 45° to 60°.

[0033] The oil atomizing nozzle 1, the primary stage ammonia gas spray hole 4, and the secondary stage ammonia gas spray hole 18 are arranged at the outlet end of the swirler 2. The oil atomizing nozzle 1 is located at the axis center of the swirler 2, and the primary air conical tube 9 is located between the oil atomizing nozzle 1 and the swirler 2.

[0034] There is a certain gap between the outer wall of the oil atomizing nozzle 1 and the inner wall of the primary air conical tube 9 to form the outlet of the direct current primary air sandwich layer 10; the primary air conical tube 9 and the swirler 2 are provided at the outlet of the oil atomizing nozzle 1. A conical direct current intersecting primary air d is formed between the inner wall of the primary air conical tube 9 and the outside of the oil atomizing nozzle 1. This primary air d is beneficial to reducing the erosion of the high-temperature flue gas flowing back to the center of the atomizing nozzle on the oil atomizing nozzle 1 and preventing the fuel in the fuel spray holes of the oil atomizing nozzle 1 from being carbonized at high temperature and blocked.

[0035] The annular ammonia gas gun chamber 19 is located between the inner wall of the outlet conical tube 5 and the outer wall of the swirler 2. The surface of the annular ammonia gas gun chamber 19 is provided with the primary stage ammonia gas spray hole 4 and the secondary stage ammonia gas spray hole 18; the primary stage ammonia gas spray hole 4 and the secondary stage ammonia gas spray hole 18 are located at the position between the outlet end face of the swirler 2 and the outlet end face of the outlet conical tube 5.

[0036] The outlet of the first-stage ammonia injection holes 4 of the annular ammonia injection gun air chamber 19 extends out of the outlet end of the swirler 2, and the extension distance is 10 - 13 cm; the outlet of the inner wall 3 of the annular ammonia injection gun is conical, and its cone angle is 23° - 26°.

[0037] The outlet of the outlet conical cylinder 5 extends out of the outlet end of the first-stage ammonia injection holes (4), and the extension distance is 16 - 18 cm; the outlet of the outlet conical cylinder 5 is conical, and its cone angle is smaller than the cone angle of the outlet of the inner wall 3 of the annular ammonia injection gun, and its cone angle is 10° - 13°. The cone angle of the outlet conical cylinder 5 is smaller than the cone angle of the outlet of the inner wall 3 of the annular ammonia injection gun, moderately extending the flame length, preventing the flame from concentrating, and being beneficial to suppressing the generation of thermal-type nitrogen oxides.

[0038] The number of injection holes of the first-stage ammonia injection holes 4 is 180 - 200, and they are divided into 10 groups and evenly distributed on the end face of the annular ammonia injection gun air chamber 19; the number of injection holes of the second-stage ammonia injection holes 18 is 270 - 300, and they are divided into 10 groups and evenly distributed on the outer side wall surface of the annular ammonia injection gun air chamber 19.

[0039] After the air enters through the combustion-supporting air inlet 13, it is finally divided into four levels to support combustion.

[0040] The first-stage combustion-supporting air is sent out in a straight-line conical shape from the primary air sandwich layer 10 between the outer wall of the fuel atomizing nozzle 1 and the inner wall of the primary air conical tube 9. This primary air d is beneficial to reducing the erosion of the high-temperature flue gas flowing back in the center of the atomizing nozzle 1 on the fuel atomizing nozzle 1 and preventing the fuel in the fuel injection holes of the fuel atomizing nozzle 1 from being carbonized at high temperature and blocked.

[0041] The second-stage combustion-supporting air is sent out by the strong swirl of the swirler 2, which plays a role in stabilizing the combustion at the center. Through the swirler 2, the high-temperature flue gas near the fuel atomizing nozzle 1 flows back, turbulently mixes with the heavy oil droplets ejected from the fuel atomizing nozzle 1, and realizes the formation of a stable heavy oil combustion flame at the center of the burner. Therefore, the swirler 2 is designed with strong swirl, adopts an axial swirl structure, the angle of its swirl vanes is 45° - 55°, and the number of vanes is 18 - 24.

[0042] The third-stage combustion-supporting air is sent out in a straight line from the tertiary air sandwich layer 11 between the swirler 2 and the inner wall 3 of the annular ammonia injection gun, moderately weakening the influence of the swirl on the first-stage ammonia injection holes 4, and helping to ignite the ammonia ejected from the first-stage ammonia injection ports outside the central fuel flame.

[0043] The fourth-stage combustion-supporting air is directly sent out from the four-way air sandwich 12 between the outer wall of the annular ammonia spray gun chamber 19 and the outlet conical cylinder 5. The cone angle of the outlet conical cylinder 5 is smaller than the outlet cone angle of the inner wall 3 of the annular ammonia spray gun, reducing the radial diffusion of the combustion-supporting air and fuel, thereby delaying the combustion of part of the ammonia fuel, and the ammonia ejected from the secondary ammonia injection holes 18 enters the reduction area of the outer flame of the burner through the formation of an oxygen-deficient environment. Through the reduction reaction of NH3 with the generated NOx in the high-temperature oxygen-deficient environment, N2 and H2O are generated, further achieving the reduction of NOx generation.

[0044] The burner housing 14 is provided with a steam inlet 15, a fuel inlet 16, an ammonia inlet 17, an ammonia gas collecting chamber 21, and a combustion-supporting air inlet 13; the combustion-supporting air inlet 13 communicates with the burner housing 14; the steam inlet 15 communicates with the steam pipe 23 inside the burner housing 14; the fuel inlet 16 communicates with the fuel gun 22 inside the burner housing 14; the ammonia inlet 17 communicates with the ammonia gas collecting chamber 21; the ammonia gas collecting chamber 21 communicates with the annular ammonia spray gun chamber 19 through ammonia pipes 20, and the number of ammonia pipes is 8 to 10.

[0045] The swirler 2 and the burner housing 14 are reserved with an igniter installation hole 7, a flame observation hole 6, and a flame detector installation hole 8.

[0046] The igniter adopts the form of a high-voltage electrode igniter using light diesel fuel. First, the fuel ejected from the fuel atomizing nozzle 1 is ignited. When the fuel ejected from the fuel atomizing nozzle 1 is ignited, the igniter goes out, and then the ammonia ejected from the primary ammonia injection holes 4 and secondary ammonia injection holes 18 outside the swirler 2 is ignited by the fuel flame; through the stable fuel flame formed in the center of the swirler 2, it is ensured that the ammonia outside the swirler 2 can be ignited by the fuel flame and stably burned.

[0047] As can be seen from the above solution, the utility model has the following characteristics: (1) This burner uses ammonia and heavy oil as the main fuels, and at the same time is assisted by a small amount of light diesel. The heavy oil fuel atomized by the central fuel gun is ignited by the light diesel ignition gun, and a stable heavy oil combustion flame is formed in the center of the burner; when the heavy oil fuel atomized by the central fuel gun is ignited, the light diesel ignition gun stops working, and then the ammonia gas ejected from the primary ammonia injection holes and the secondary ammonia injection holes outside the swirler is ignited by the heavy oil flame; through the staged combustion of ammonia fuel and the staged supply of combustion-supporting air, stable low-carbon and low-nitrogen combustion of ammonia and heavy oil in the boiler furnace can be achieved. (2) Both the ammonia fuel and the combustion-supporting air are fed into the boiler furnace in a staged manner. Among them, the ammonia fuel is fed in a two-stage manner, and the combustion-supporting air is fed in a four-stage manner; through the swirler, the high-temperature flue gas near the fuel atomizing nozzle is refluxed, and turbulently mixed with the heavy oil droplets ejected from the fuel atomizing nozzle, so as to form a stable heavy oil combustion flame at the center of the burner; by means of the three-way direct current air, the turbulence intensity of the secondary swirling air is weakened, which helps to ignite the ammonia gas ejected from the primary ammonia injection port outside the periphery of the central fuel flame. (3) A primary air conical tube and a swirler are provided at the outlet of the fuel atomizing nozzle. A conical direct current intersecting primary air is formed between the inner wall of the primary air conical tube and the outside of the fuel atomizing nozzle. This primary air is beneficial to reducing the erosion of the high-temperature flue gas flowing back to the center of the atomizing nozzle on the fuel atomizing nozzle, and preventing the fuel in the fuel injection holes of the fuel atomizing nozzle from being carbonized at high temperature and blocked. (3) The cone angle of the outlet conical cylinder is smaller than the outlet cone angle of the inner wall of the annular ammonia spray gun, which moderately extends the flame length, prevents the flame from concentrating, and is beneficial to suppressing the generation of thermal-type nitrogen oxides; the ammonia gas ejected from the secondary ammonia injection holes is mixed with the four-way air to form a fuel-rich outer region, enters the reduction region of the outer flame of the burner, and through the reduction reaction of NH3 with the generated NOx in the high-temperature and oxygen-deficient environment, N2 and H2O are generated, further achieving the purpose of suppressing the generation of NOx.

Claims

1. A marine boiler ammonia-oil dual-fuel burner, characterized in that, It includes a fuel atomizing nozzle (1), a swirler (2), the inner wall of an annular ammonia spray gun (3), primary ammonia spray holes (4), secondary ammonia spray holes (18), an outlet conical tube (5), a primary air conical tube (9), a primary air sandwich layer (10), a tertiary air sandwich layer (11), a quaternary air sandwich layer (12), a burner housing (14), an annular ammonia spray gun air chamber (19), a fuel gun (22), and a steam pipe (23); The inner wall of the annular ammonia spray gun (3), the primary air conical tube (9), the annular ammonia spray gun air chamber (19), the fuel gun (22), and the steam pipe (23) are coaxial with the burner housing (14) and are placed in the inner cavity of the burner housing (14); The annular ammonia spray gun air chamber (19) is located between the inner wall of the outlet conical tube (5) and the outer wall of the swirler (2). The surface of the annular ammonia spray gun air chamber (19) is provided with primary ammonia spray holes (4) and secondary ammonia spray holes (18); the primary ammonia spray holes (4) and the secondary ammonia spray holes (18) are located at the position between the outlet end face of the swirler (2) and the outlet end face of the outlet conical tube (5); The annular ammonia spray gun air chamber (19) is coaxially provided with a fuel atomizing nozzle (1), a primary air conical tube (9), and a swirler (2); the fuel atomizing nozzle (1), the primary ammonia spray holes (4), and the secondary ammonia spray holes (18) are arranged at the outlet end of the swirler (2). The fuel atomizing nozzle (1) is located at the axis of the swirler (2), and the primary air conical tube (9) is located between the fuel atomizing nozzle (1) and the swirler (2); There is a certain gap between the outer wall of the fuel atomizing nozzle (1) and the inner wall of the primary air conical tube (9) to form the outlet of the direct - flow primary air sandwich layer (10); A number of fuel spray holes are evenly distributed on the circumference of the fuel atomizing nozzle (1), and the included angle between the fuel spray holes and the axis of the burner housing (14) is 45° - 60°; A number of primary ammonia spray holes (4) and secondary ammonia spray holes (18) are evenly distributed circumferentially on the outside of the swirler (2). The primary ammonia spray holes (4) face the axial direction of the swirler (2), and the secondary ammonia spray holes (18) face the radial direction of the swirler (2); There is a gap between the outer wall of the swirler (2) and the inner wall of the annular ammonia spray gun (3) to form the outlet of the direct - flow tertiary air sandwich layer (11); There is a certain gap between the outer wall of the annular ammonia spray gun air chamber (19) and the inner wall of the outlet conical tube (5) to form the outlet of the direct - flow quaternary air sandwich layer (12).

2. The marine boiler ammonia-oil dual-fuel burner according to claim 1, characterized in that: The fuel outlet of the atomizing nozzle (1) is located at the outlet end face of the swirler (2). The fuel atomizing nozzle (1) is installed on the outlet end faces of the fuel gun (22) and the steam pipe (23), and the structure of the fuel atomizing nozzle (1) is a Y - type steam atomizing nozzle structure.

3. The marine boiler ammonia-oil dual-fuel burner according to claim 1, characterized in that: The fuel gun (22), the steam pipe (23), and the fuel atomizing nozzle (1) are coaxial. The steam pipe (23) is nested inside the fuel gun (22), and the fuel atomizing nozzle (1) is respectively connected to the fuel gun (22) and the steam pipe (23).

4. The marine boiler ammonia-oil dual-fuel burner according to claim 1, wherein: The outlet of the primary ammonia injection holes (4) of the annular ammonia injection gun air chamber (19) extends out of the outlet end of the swirler (2), and the extension distance is 10 - 13 cm; the outlet of the inner wall (3) of the annular ammonia injection gun is conical, and its cone angle is 23° - 26°.

5. The marine boiler ammonia-oil dual-fuel burner according to claim 1, characterized in that: The outlet of the outlet conical cylinder (5) extends out of the outlet end of the primary ammonia injection holes (4), and the extension distance is 16 - 18 cm; the outlet of the outlet conical cylinder (5) is conical, and its cone angle is smaller than the cone angle of the outlet of the inner wall (3) of the annular ammonia injection gun, and its cone angle is 10° - 13°.

6. The marine boiler ammonia-oil dual-fuel burner according to claim 1, characterized in that: The swirler (2) is of an axial swirl structure, the angle of its swirl vanes is 45° - 55°, and the number of vanes is 18 - 24.

7. The marine boiler ammonia-oil dual-fuel burner according to claim 1, characterized in that: The burner housing (14) is provided with a steam inlet (15), a fuel inlet (16), an ammonia inlet (17), an ammonia gas collecting chamber (21), and a combustion-supporting air inlet (13); the combustion-supporting air inlet (13) communicates with the burner housing (14); the steam inlet (15) communicates with the steam pipe (23) inside the burner housing (14); the fuel inlet (16) communicates with the fuel gun (22) inside the burner housing (14); the ammonia inlet (17) communicates with the ammonia gas collecting chamber (21).

8. The marine boiler ammonia-oil dual-fuel burner according to claim 7, characterized in that: The ammonia gas collecting chamber (21) communicates with the annular ammonia injection gun air chamber (19) through ammonia pipes (20), and the number of ammonia pipes is 8 - 10.

9. The marine boiler ammonia-oil dual-fuel burner according to claim 1, characterized in that: The swirler (2) and the burner housing (14) are reserved with an igniter installation hole (7), a flame observation hole (6), and a flame detector installation hole (8).

10. The marine boiler ammonia-oil dual-fuel burner according to claim 1, characterized in that: The number of injection holes of the primary ammonia injection holes (4) is 180 - 200, and they are divided into 10 groups and evenly distributed on the end face of the annular ammonia injection gun air chamber (19); the number of injection holes of the secondary ammonia injection holes (18) is 270 - 300, and they are divided into 10 groups and evenly distributed on the outer side wall surface of the annular ammonia injection gun air chamber (19).

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