Marine methanol dual fuel staged atomizing burner

Abstract

The application discloses a methanol dual-fuel staged atomization burner for ships and relates to the technical field of thermal energy engineering.A core component of the application comprises a wind box, a door plate assembly, a methanol valve box, a main fuel gun, an ignition gun, a cyclone, a metal throat assembly and the like.The burner controls the atomization of methanol and other fuels through a flow divider and an atomizing nozzle, and realizes stable fuel flame through a cyclone.The atomizing nozzle adopts a staged Y-shaped structure, can adjust the spray hole according to different fuels, and realizes different injection requirements of fuel oil and methanol.The burner is divided into three stages to support combustion through the accurate cooperation of combustion-supporting wind, pipeline purging wind and a fuel inlet, so that an efficient and low-pollution combustion process is ensured.The combustion-supporting wind forms secondary cyclone through the cyclone, reduces the scouring of backflow flue gas on the nozzle, and ensures the stability of the core flame of the burner.The metal throat assembly controls the diameter of the combustion flame, and ensures uniform combustion.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thermal energy engineering, in particular to a marine methanol dual-fuel staged atomization burner. BACKGROUND

[0002] The conventional auxiliary boiler is matched with a fuel oil burner adopting a steam atomization type structure. Since the methanol fuel has a low heat value (about half of that of fuel oil), the methanol consumption is more than twice the volume of fuel oil under the same load condition of the boiler. The volume flow of the atomizer of the methanol burner is doubled compared with that of fuel oil, which exceeds the flow range of the fuel oil atomizing nozzle. Therefore, the existing fuel oil medium atomizing nozzle cannot meet the full atomization requirements of methanol and fuel oil dual fuel. The air-fuel ratio of methanol is about half of that of fuel oil, and the flame propagation speed of methanol is faster than that of fuel oil, which leads to a certain difference in the shape and size of the combustion flame. In the marine dual-fuel boiler, methanol and fuel oil are both burned in the same boiler furnace. Therefore, the size of the combustion flame needs to meet the structural size requirements of the boiler furnace to ensure that the core of the fuel combustion flame cannot wash the inner wall of the furnace. Compared with the commonly used fuel oil fuel for marine boilers, methanol fuel has the characteristics of low flash point, easy evaporation and toxicity. Therefore, it is necessary to prevent the harm caused by methanol leakage. SUMMARY

[0003] In order to overcome the defects of the prior art, the present application provides the following technical scheme: a marine methanol dual-fuel staged atomization burner is composed of a wind box, a door plate assembly, an inlet methanol valve box, a main fuel gun, an ignition gun, a flame detector, a metal throat assembly, a cyclone, an air sleeve assembly, a flame observation window and a fixed pipe assembly. The main fuel gun is mainly composed of a three-wall pipe flange, a quick connector, a flange, a steel pipe, a positioning ring, a flow divider, a locking nut, an atomizing nozzle, a positioning sleeve and an elbow pipe. The inlet methanol valve box is mainly composed of a box body, a cover plate, a three-wall pipe matched flange, a straight pipe, an outer ring fuel inlet pipe, a fuel pipe, a quick connector, an inner ring fuel inlet pipe, a double-wall pipe flange, a pipeline purge air outlet pipe, a tee joint, a methanol fuel pipe and a check valve. The main fuel gun, the metal throat assembly, the cyclone, the air sleeve assembly and the fixed pipe assembly are coaxial with the outlet cylinder of the wind box and are arranged in the inner cavity of the wind box. The door plate assembly is coaxial with the outlet cylinder of the wind box and is fixed on the surface of the wind box. The door plate assembly is provided with the inlet methanol valve box, the ignition gun, the flame detector, the flame observation window and the fixed pipe assembly. The outer wall of the atomizing nozzle and the central inner wall of the cyclone have a certain gap and form a straight-flow primary air outlet. The inner wall of the metal throat assembly and the outer wall of the cyclone form a straight-flow tertiary air outlet. The gap between the blades of the cyclone forms a rotational-flow secondary air outlet.

[0004] Preferably, the wind box shell is provided with a combustion-supporting air inlet; the ignition gun is provided with a light diesel oil inlet; the main fuel gun is provided with an atomization medium inlet and a pipeline purge air inlet; the inlet methanol valve box is provided with a main fuel oil inlet, a methanol fuel inlet and a pipeline purge air outlet.

[0005] Preferably, the combustion-supporting air inlet is in communication with the wind box, the air sleeve assembly and the metal throat assembly; the atomization medium inlet is in communication with the partial steel pipe, the flow divider and the atomization nozzle of the main fuel gun; the pipeline purge air inlet is in communication with the elbow pipe, the straight pipe, the box body, the pipeline purge air outlet pipe and the double-wall pipe flange.

[0006] Preferably, the main fuel oil inlet is in communication with the quick connector, the fuel pipe, the partial check valve, the tee joint, the inner ring fuel inlet pipe, the partial steel pipe, the flow divider and the atomization nozzle of the methanol valve box.

[0007] Preferably, the methanol fuel inlet is in communication with the tee joint, the methanol fuel pipe, the partial check valve, the tee joint, the outer ring fuel inlet pipe, the inner ring fuel inlet pipe, the three-wall pipe flange, the partial steel pipe, the flow divider and the atomization nozzle.

[0008] Preferably, the three-wall pipe flange is provided with two rings of fuel through holes, one ring of pipeline purge air through holes and flange bolt connection holes; the three-wall pipe flange and the three-wall pipe mating flange are separated and sealed from each other by the two rings of fuel and the pipeline purge air through the three rings of O-shaped sealing rings.

[0009] Preferably, the ignition gun is in the form of a high-voltage electrode ignition gun using light diesel fuel, and the atomized fuel sprayed from the atomization nozzle is ignited; after the fuel sprayed from the atomization nozzle is ignited, the ignition gun is extinguished, and the stable fuel flame formed by the central part of the swirler ensures the stable combustion of the atomized fuel.

[0010] Preferably, the swirler is arranged at the outlet of the atomization nozzle, and a conical straight-flow intersection primary air is formed between the inner wall of the central part of the swirler and the outer wall of the atomization nozzle, which is beneficial to reducing the erosion of the atomization nozzle by the high-temperature flue gas backflowing in the center of the atomization nozzle, and preventing the fuel injection hole of the atomization nozzle from being blocked by high-temperature carbonization of fuel.

[0011] Preferably, the fuel outlet of the atomization nozzle is located at the outlet end surface of the swirler, and the atomization nozzle is fastened to the outlet end surface of the flow divider of the main fuel gun by a locking nut.

[0012] Preferably, the atomization nozzle has a hierarchical Y-type medium atomization nozzle structure, and the central part of the atomization nozzle is provided with two rings of atomization medium inlet holes, the inner ring hole is in communication with hole k of the atomization nozzle, and the outer ring hole is in communication with hole m of the atomization nozzle.

[0013] Preferably, the atomization nozzle is provided with two rings of fuel inlet holes at the end surface, and the outer surface of the atomization nozzle is provided with inner and outer rings of fuel and atomization medium mixing outlet holes.

[0014] Preferably, when the burner burns fuel oil, the hole e of the atomizing nozzle is connected to fuel oil, the hole m is connected to fuel oil and atomizing medium, and the hole k is connected to atomizing medium only; when the burner burns methanol, the hole e and the hole f of the atomizing nozzle are connected to methanol, and the hole m and the hole k are connected to methanol and atomizing medium. The same atomizing nozzle is used to fully atomize and burn methanol or fuel oil at the same heat load with a large flow difference (the volume flow of methanol fuel is about twice that of fuel oil). Preferably, the hole m and the hole g of the atomizing nozzle are coaxial, the hole m is connected to the hole e and the angle between the axes is 50-65°; the hole k and the hole h are coaxial, the hole k is connected to the hole f and the angle between the axes is 50-65°; the angle between the hole m and the hole k and the axis of the atomizing nozzle is 45-60°.

[0015] Preferably, the swirler is an axial swirler structure, the angle of the swirler blade is 45-55°, and the number of the blades is 18-24.

[0016] Preferably, the inner wall of the metal throat assembly is conical, the cone angle is 20-30°, and the distance between the outlet end face of the metal throat assembly and the atomizing nozzle of the main fuel gun is 10-20 cm.

[0017] Compared with the prior art, the ship methanol dual-fuel staged atomizing burner has the following advantages: (1) The ship methanol dual-fuel staged atomizing burner uses methanol or heavy oil as the main fuel, and a small amount of light diesel oil is used as an auxiliary fuel. The light diesel oil ignition gun ignites the methanol or heavy oil fuel atomized by the main fuel gun, and a stable methanol or heavy oil combustion flame is formed at the outlet of the central swirler of the burner. When the fuel atomized by the central main fuel gun is ignited, the light diesel oil ignition gun stops working.

[0018] (2) The methanol fuel and the combustion air are both fed into the boiler furnace in stages. The methanol fuel is fed into the boiler furnace in two stages through the two-stage mixed holes of the atomizing nozzle, and the combustion air is fed into the boiler furnace in three stages. The high-temperature flue gas near the methanol atomizing nozzle is made to flow back by the swirler, and is mixed with the methanol droplets sprayed by the atomizing nozzle, so that a stable methanol combustion flame is formed at the center of the burner. The three-stage straight-flow air weakens the turbulence intensity of the two-stage rotational-flow air, and wraps the methanol fuel sprayed by the atomizing nozzle, which helps to control the diameter of the methanol combustion flame of the main fuel gun.

[0019] (3) The outlet of the methanol atomizing nozzle is provided with a swirler, and the central inner wall surface of the swirler forms a conical straight-flow intersection primary air with the atomizing nozzle. The primary air is beneficial to reducing the erosion of the high-temperature flue gas flowing back in the center of the atomizing nozzle on the fuel atomizing nozzle, and preventing the fuel oil in the fuel oil spray hole of the atomizing nozzle from being carbonized and blocked at high temperature.

[0020] (4) Through the hierarchical medium atomizing nozzle structure, the methanol or fuel oil is fully atomized and combusted under the same heat load and large flow difference (the volume flow of methanol fuel is about twice that of fuel oil), so that one main oil gun can meet the methanol and fuel oil fuel at the same time, and the methanol dual fuel burner can meet the compactness requirement of the marine boiler.

[0021] (5) The inlet methanol valve box is arranged on the door plate assembly of the methanol dual fuel burner, the internal pipeline and the one-way valve are arranged in the inlet methanol valve box, so that the fuel oil entering the inlet methanol valve box is atomized and sprayed out from the outer circle hole m of the atomizing nozzle of the main fuel gun; the methanol fuel entering the inlet methanol valve box is atomized and sprayed out from the outer circle hole m and the inner circle hole k of the atomizing nozzle of the main fuel gun. Through the above-mentioned mode, the hierarchical atomization of the methanol fuel under the large flow difference is realized.

[0022] (6) The three-wall pipe or double-wall pipe flange structure is arranged on the main fuel gun and the inlet addition valve box, air is continuously introduced into the external pipeline of the methanol fuel pipeline, so that the methanol leakage in the methanol pipeline is quickly blown to the outside safe area of the cabin by the sweeping air in the external pipeline of the methanol pipeline, the methanol fuel entering the burner is effectively prevented from leaking into the cabin, and the safety of the methanol fuel supply leakage of the marine methanol dual fuel burner is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the present application; in the figure, A is the combustion air inlet; B is the atomizing medium inlet; C is the pipeline sweeping air inlet.

[0024] Figure 2 It is a schematic diagram of the internal structure of the wind box of the present application; in the figure, D is the ignition light diesel oil inlet; E is the main fuel oil inlet; F is the methanol fuel inlet and the pipeline sweeping air outlet.

[0025] Figure 3 It is a sectional view of the overall structure of the present application; in the figure, a is the tertiary air; b is the secondary air; c is the primary air.

[0026] Figure 4 It is a schematic diagram of the main fuel gun structure of the present application.

[0027] Figure 5 It is a sectional view of the main fuel gun of the present application.

[0028] Figure 6 It is a front view of the three-wall pipe flange structure of the present application.

[0029] Figure 7 It is a left sectional view of the three-wall pipe flange structure of the present application.

[0030] Figure 8 It is a front view of the atomizing nozzle structure of the present application.

[0031] Figure 9The left view of the atomizing nozzle structure of the present application.

[0032] Figure 10 The left sectional view of the atomizing nozzle of the present application.

[0033] Figure 11 The axonometric view of the atomizing nozzle of the present application.

[0034] Figure 12 The front view of the inlet methanol valve box of the present application.

[0035] Figure 13 The sectional view of the inlet methanol valve box structure of the present application.

[0036] Figure 14 The schematic view of the internal structure of the inlet methanol valve box of the present application.

[0037] In the figure: 1 - wind box; 2 - door plate assembly; 3 - inlet methanol valve box; 4 - main fuel gun; 5 - ignition gun; 6 - flame detector; 7 - metal throat assembly; 8 - cyclone; 9 - air sleeve assembly; 10 - flame observation window; 11 - fixed tube assembly; 12 - three-wall tube flange; 13 - quick connector; 14 - flange; 15 - steel tube; 16 - positioning ring; 17 - flow divider; 18 - locking nut; 19 - atomizing nozzle; 20 - positioning sleeve; 21 - elbow; 22 - box; 23 - cover plate; 24 - three-wall tube mating flange; 25 - straight tube; 26 - outer ring fuel inlet tube; 27 - fuel tube; 28 - quick connector; 29 - inner ring fuel inlet tube; 30 - double-wall tube flange; 31 - pipeline purge air outlet tube; 32 - tee joint; 33 - methanol fuel tube; 34 - tee joint; 35 - one-way valve. DETAILED DESCRIPTION

[0038] The technical solutions of the present application are further illustrated below by specific embodiments in combination with the accompanying drawings.

[0039] As Figures 1-14As shown, the marine methanol dual fuel staged atomizing burner of the embodiment mainly consists of a wind box 1, a door plate assembly 2, an inlet methanol valve box 3, a main fuel gun 4, an ignition gun 5, a flame detector 6, a metal throat assembly 7, a swirler 8, an air sleeve assembly 9, a flame observation window 10, and a fixed tube assembly 11. The main fuel gun 4 mainly consists of a three-wall tube flange 12, a quick connector 13, a flange 14, a steel tube 15, a positioning ring 16, a flow divider 17, a locking nut 18, an atomizing nozzle 19, a positioning sleeve 20, and an elbow 21. The inlet methanol valve box 3 mainly consists of a box body 22, a cover plate 23, a three-wall tube matching flange 24, a straight tube 25, an outer ring fuel inlet tube 26, a fuel tube 27, a quick connector 28, an inner ring fuel inlet tube 29, a double-wall tube flange 30, a pipeline purge air outlet tube 31, a tee joint 32, a methanol fuel tube 33, a tee joint 34, and a one-way valve 35. The main fuel gun 4, the metal throat assembly 7, the swirler 8, the air sleeve assembly 9, and the fixed tube assembly 11 are coaxial with the outlet cylinder of the wind box 1 and are arranged in the inner cavity of the wind box 1. The door plate assembly 2 is coaxial with the outlet cylinder of the wind box 1 and is fixed on the surface of the wind box 1. The door plate assembly 2 is provided with the inlet methanol valve box 3, the ignition gun 5, the flame detector 6, the flame observation window 10, and the fixed tube assembly 11.

[0040] The wind box 1 is provided with a combustion air inlet A. The ignition gun 5 is provided with an ignition light diesel oil inlet D. The main fuel gun 4 is provided with an atomizing medium inlet B and a pipeline purge air inlet C. The inlet methanol valve box 3 is provided with a main fuel oil inlet E, a methanol fuel inlet, and a pipeline purge air outlet F.

[0041] The combustion air inlet A is in communication with the wind box 1, the air sleeve assembly 9, and the metal throat assembly 7. The atomizing medium inlet B is in communication with part of the steel tube 15, the flow divider 17, and the atomizing nozzle 19 of the main fuel gun 4. The pipeline purge air inlet C is in communication with the elbow 21, the straight tube 25, the box body 22, the pipeline purge air outlet tube 31, and the double-wall tube flange 30.

[0042] The main fuel oil inlet E is in communication with the quick connector 28, the fuel tube 27, part of the one-way valve 35, the tee joint 34, the inner ring fuel inlet tube 29, part of the steel tube 15, the flow divider 17, and the atomizing nozzle 19 of the methanol valve box 3.

[0043] The methanol fuel inlet F is in communication with the tee joint 32, the methanol fuel tube 33, part of the one-way valve 35, the tee joint 34, the outer ring fuel inlet tube 26, the inner ring fuel inlet tube 29, the three-wall tube flange 12, part of the steel tube 15, the flow divider 17, and the atomizing nozzle 19.

[0044] The three-wall tube flange 12 is provided with two rings of fuel through holes b and holes a, one ring of pipeline purge air through holes c, and flange bolt connection holes d. The three-wall tube flange 12 and the three-wall tube matching flange 24 are separated and sealed from each other by three rings of O-shaped sealing rings.

[0045] The ignition gun 5 is in the form of a high-pressure electrode ignition gun using light diesel fuel, and the atomized fuel sprayed from the atomizing nozzle 19 is ignited. After the fuel sprayed from the atomizing nozzle 19 is ignited, the ignition gun 5 is extinguished, and the stable fuel flame formed through the center of the swirler 8 ensures stable combustion of the atomized fuel. The fuel outlet of the atomizing nozzle 19 is located at the outlet end surface of the swirler 8, and the atomizing nozzle 19 is fastened to the outlet end surface of the diverter 17 of the main fuel gun 4 by means of the locking nut 18. The atomizing nozzle 19 is of a stepped Y-shaped medium atomizing nozzle structure, and the center of the atomizing nozzle 19 is provided with two rings of atomizing medium inlet holes, i.e. the inner ring of holes h and the outer ring of holes g. The inner ring of holes h is in communication with the hole k of the atomizing nozzle 19, and the outer ring of holes g is in communication with the hole m of the atomizing nozzle 19. The end surface of the atomizing nozzle 19 is provided with two rings of fuel inlet holes e and f, and the outer surface of the atomizing nozzle 19 is provided with two rings of fuel and atomizing medium mixing outlet holes k and m. When the burner burns fuel oil, the holes e of the atomizing nozzle 19 are connected to fuel oil, the holes m are connected to fuel oil and atomizing medium, and the holes k are connected to atomizing medium only; when the burner burns methanol, the holes e and f of the atomizing nozzle 19 are connected to methanol, and the holes m and k are connected to methanol and atomizing medium. The holes m and g of the atomizing nozzle 19 are coaxial, the hole m is in communication with the hole e and the angle between the axes is 50°-65°; the hole k is coaxial with the hole h, and the hole k is in communication with the hole f and the angle between the axes is 50°-65°; the angle between the axes of the hole m and the hole k and the axis of the atomizing nozzle 19 is 45°-60°. The inner wall of the metal throat assembly 7 is conical, and the angle of the cone is 20°-30°; the outlet end surface of the metal throat assembly 7 extends 10-20 cm beyond the atomizing nozzle 19 of the main fuel gun 4. After the air enters through the combustion air inlet A, it is finally divided into three levels of support combustion. The first level of combustion air is formed between the outer wall of the atomizing nozzle 19 and the inner wall of the center of the swirler 8 with a certain gap and a straight-flow primary air c outlet, which is beneficial to reduce the scouring of the high-temperature flue gas flowing back in the center of the atomizing nozzle 19 on the atomizing nozzle 19, and prevent the fuel oil injection holes of the atomizing nozzle 19 from being blocked by high-temperature carbonization of fuel oil.

[0046] The second level of combustion air is formed between the swirler 8 blades and the outer wall of the swirler 8 with a certain gap and a swirl-flow secondary air b outlet, which plays a central stabilizing role. The high-temperature flue gas flowing back around the methanol or fuel oil atomizing nozzle 19 is mixed with the methanol or heavy oil droplets sprayed from the atomizing nozzle 19 by the swirler 8, so that a stable fuel combustion flame is formed at the center of the burner. Therefore, the swirler 8 is designed as a strong swirl, and is of an axial swirl structure, with the angle of the swirl blades being 45°-55° and the number of the blades being 18-24.

[0047] The third level of combustion air is formed between the inner wall of the metal throat assembly 7 and the outer wall of the swirler 8 with a certain gap and a straight-flow tertiary air a outlet, which reduces the turbulence intensity of the secondary swirl air, wraps the methanol fuel sprayed from the atomizing nozzle, and is helpful to control the diameter size of the methanol combustion flame of the main fuel gun.

Claims

1. A marine methanol dual fuel staged atomizing burner characterized by: The application relates to a wind box (1), a door plate assembly (2), an inlet methanol valve box (3), a main fuel gun (4), an ignition gun (5), a flame detector (6), a metal throat assembly (7), a swirler (8), an air sleeve assembly (9), a flame observation window (10) and a fixed tube assembly (11); wherein the main fuel gun (4) is mainly composed of a three-wall tube flange (12), a quick connector, a flange (14), a steel tube (15), a positioning ring (16), a flow divider (17), a locking nut (18), an atomizing nozzle (19), a positioning sleeve (20) and an elbow (21); The inlet methanol valve box (3) is mainly composed of a box body (22), a cover plate (23), a three-wall tube matched flange (24), a straight tube (25), an outer ring fuel inlet tube (26), a fuel tube (27), a quick connector, an inner ring fuel inlet tube (29), a double-wall tube flange (30), a pipeline purge air outlet tube (31), a No. 1 three-way connector (32), a methanol fuel tube (33), a No. 2 three-way connector (34) and a check valve (35); The main fuel gun (4), the metal throat assembly (7), the swirler (8), the air sleeve assembly (9) and the fixed tube assembly (11) are coaxial with the outlet cylinder of the wind box (1) and are arranged in the inner cavity of the wind box (1); the door plate assembly (2) is coaxial with the outlet cylinder of the wind box (1) and is fixed on the surface of the wind box (1); The door plate assembly (2) is provided with the inlet methanol valve box (3), the ignition gun (5), the flame detector (6), the flame observation window (10) and the fixed tube assembly (11); a certain gap is formed between the outer wall of the atomizing nozzle (19) and the central inner wall of the swirler (8) and a straight-flow primary air c outlet is formed; a straight-flow tertiary air a outlet is formed between the inner wall of the metal throat assembly (7) and the outer wall of the swirler (8); a rotational-flow secondary air b outlet is formed between the blade gaps of the swirler (8); The outer shell of the wind box (1) is provided with a combustion-supporting air inlet A; the ignition gun (5) is provided with an ignition light diesel oil inlet D; the main fuel gun (4) is provided with an atomizing medium inlet B and a pipeline purge air inlet C; the inlet methanol valve box (3) is provided with a main fuel oil inlet E, a methanol fuel inlet and a pipeline purge air outlet F; The combustion-supporting air inlet A is communicated with the wind box (1), the air sleeve assembly (9) and the metal throat assembly (7); the atomizing medium inlet B is communicated with part of the steel tube (15), the flow divider (17) and the atomizing nozzle (19) of the main fuel gun (4); the pipeline purge air inlet C is communicated with the elbow (21), the straight tube (25), the box body (22), the pipeline purge air outlet tube (31) and the double-wall tube flange (30); The main fuel oil inlet E is communicated with the quick connector, the fuel tube (27), part of the check valve (35), the No. 2 three-way connector (34), the inner ring fuel inlet tube (29), part of the steel tube (15), the flow divider (17) and the atomizing nozzle (19) of the methanol valve box (3); Methanol fuel inlet F and a three-way joint (32), methanol fuel pipe (33), part of the check valve (35), the second three-way joint (34), outer ring fuel inlet pipe (26), inner ring fuel inlet pipe (29), three-wall pipe flange (12), part of the steel pipe (15), flow divider (17), atomizing nozzle (19) communication.

2. A marine methanol dual fuel staged atomizing burner according to claim 1, characterized in that: The center of the three-wall pipe flange (12) is provided with two circles of fuel holes b and holes a, a circle of pipeline purge air holes c, and flange bolt connection holes d; the three-wall pipe flange (12) and the three-wall pipe mating flange (24) are sealed from each other by three O-rings to separate the two circles of fuel and the pipeline purge air.

3. A marine methanol dual fuel staged atomizing burner according to claim 2, characterized in that: The ignition gun (5) is in the form of a high-pressure electrode ignition gun using light diesel fuel, and the atomizing fuel sprayed by the atomizing nozzle (19) is ignited. When the fuel sprayed by the atomizing nozzle (19) is ignited, the ignition gun (5) is extinguished, and a stable fuel flame is formed through the cyclone (8) to ensure stable combustion of the atomized fuel. The outlet of the atomizing nozzle (19) is provided with a cyclone (8), and a conical straight flow intersection primary air c is formed between the inner wall of the center of the cyclone (8) and the outer wall of the atomizing nozzle (19). This primary air is used to reduce the erosion of the atomizing nozzle (19) by the high-temperature flue gas flowing back to the center of the atomizing nozzle (19), preventing the fuel injection hole of the atomizing nozzle (19) from being blocked by high-temperature carbonization of fuel. The fuel outlet of the atomizing nozzle (19) is located at the outlet end surface of the cyclone (8), and the atomizing nozzle (19) is installed and fastened on the outlet end surface of the flow divider (17) of the main fuel gun (4) through the locking nut (18).

4. A marine methanol dual fuel staged atomizing burner according to claim 3, characterized in that: The structure of the atomizing nozzle (19) is a hierarchical Y-type medium atomizing nozzle structure, and the center of the atomizing nozzle (19) is provided with two circles of atomizing medium inlet holes h and g. The inner circle hole h is in communication with the hole k of the atomizing nozzle (19), and the outer circle hole g is in communication with the hole m of the atomizing nozzle (19). The end surface of the atomizing nozzle (19) is provided with two circles of fuel inlet holes e and f, and the outer surface of the atomizing nozzle (19) is provided with inner and outer two circles of fuel and atomizing medium mixing outlet holes k and m. When the burner burns fuel, hole e of the atomizing nozzle (19) is connected to fuel, hole m is connected to fuel and atomizing medium, and hole k is only connected to atomizing medium; when the burner burns methanol, holes e and f of the atomizing nozzle (19) are connected to methanol, holes m and k are connected to methanol and atomizing medium.

5. A marine methanol dual fuel staged atomizing burner according to claim 4, characterized in that: The hole m and the hole g on the atomizing nozzle (19) are coaxial, the hole m is in communication with the hole e and the axis angle is 50°-65°; the hole k and the hole h are coaxial, the hole k is in communication with the hole f and the axis angle is 50°-65°; the axis angle between the hole m and the hole k and the axis of the atomizing nozzle (19) is 45°-60°.

6. A marine methanol dual fuel staged atomizing burner according to claim 5, characterized in that: The cyclone (8) is an axial cyclone structure, the angle of the cyclone blade is 45°-55°, and the number of blades is 18-24.

7. A marine methanol dual fuel staged atomizing burner according to claim 6, characterized in that: The inner wall of the metal throat assembly (7) is conical, and the cone angle is 20°-30°; the distance between the outlet end surface of the metal throat assembly (7) and the atomizing nozzle (19) of the main fuel gun (4) is 10-20 cm.

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