A stable combustion type swirl burner structure with an air flow restraining sleeve

Abstract

The utility model discloses a kind of stable combustion type swirl burner structures with airflow restraint sleeve, including burner shell: it is cylindrical two-end open pipeline, one end is the import end of combustion-supporting air, the other end is the outlet end that mixed material is ejected and burns;Swirl structure: it includes the swirl vane arranged in outlet end;Stable combustion sleeve structure: it is cylindrical structure, and it is connected on outlet end along the axis of burner, it includes sequentially connected combustion section and outlet section, the inner diameter of the combustion section is greater than the outer diameter of burner shell, to provide the expansion space of flame combustion, the front half of the outlet section is contraction part, and the latter half is flat part.The utility model cooperates through stable combustion sleeve and honeycomb structure, greatly broaden stable combustion working condition range, improve combustion efficiency;Effectively reduce pollutant emission, water jacket design guarantees equipment safety and prolongs service life, and modular structure is strong in adaptability, and it has environmental protection and practical value.

Description

Technical Field

[0001] This utility model relates to the field of burner technology, specifically to a stable combustion swirl burner structure with an airflow constraint sleeve. Background Technology

[0002] Flame stability and long-term operational reliability of burners are core indicators for evaluating combustion performance, especially in high-temperature combustion scenarios such as industrial kilns and boilers, where these indicators directly affect combustion efficiency, pollutant emissions, and equipment lifespan. In existing burner nozzle structures, to achieve flame stability, swirl vanes and other structures are often used to create a recirculation zone, utilizing the recirculation of high-temperature flue gas to maintain ignition and combustion continuity. However, this design still has significant limitations in practical applications.

[0003] Traditional flame stabilization structures are poorly adapted to airflow disturbances. When there are fluctuations in the furnace airflow, fuel supply pressure, combustion air flow, or fuel composition, the recirculation zone is prone to deformation or even rupture, leading to instability at the flame front. This can result in minor issues such as partial flameout and incomplete combustion, increasing emissions of pollutants like CO and NOx, or even serious safety hazards like flameout and backfire. The core reason for this deficiency is that existing recirculation zones mainly rely on a single swirl or blunt body wake to form, lacking a graded constraint and energy compensation mechanism for the airflow. Once external conditions change, the energy balance of the recirculation zone is disrupted, making it difficult to autonomously restore stability.

[0004] Furthermore, the inherent contradiction between flame stabilization and heat dissipation in existing technologies is difficult to reconcile. To enhance flame stabilization, structural design is needed to strengthen the retention of high-temperature flue gas, which inevitably leads to flame stabilization components operating in a high-temperature environment (typically above 1000℃) for extended periods. While relying solely on water cooling or insulation layers can reduce the surface temperature of components, it weakens the energy feedback of heat radiation to the flame root, which is detrimental to ignition stability under low-load conditions. This contradiction—that "flame stabilization requires high temperatures, while durability requires cooling"—makes it difficult for existing structures to balance stability and durability across a wide load range.

[0005] For the reasons mentioned above, it is necessary to propose a stable swirl burner structure with an airflow confinement sleeve to solve the above problems. Utility Model Content

[0006] The purpose of this invention is to overcome the defects in the existing technology and provide a stable combustion swirl burner structure with an airflow confinement sleeve.

[0007] To achieve the above objectives, the technical solution of this utility model is as follows: A stable swirl burner structure with an airflow confinement sleeve, comprising: Burner shell: It is a cylindrical pipe with open pipes at both ends. One end is the inlet of the combustion air and the other end is the outlet of the mixture for combustion. Hydrocyclone structure: It includes swirling blades disposed inside the outlet end; The stable combustion sleeve structure is cylindrical and connected to the outlet end along the axis of the burner. It includes a combustion section and an outlet section connected in sequence. The inner diameter of the combustion section is larger than the outer diameter of the burner shell to provide expansion space for flame combustion. The front half of the outlet section is a contraction section and the rear half is a straight section.

[0008] Furthermore, the wall of the combustion stabilizing sleeve structure is provided with a water jacket structure, which is divided into a combustion section water jacket and an outlet section water jacket.

[0009] Furthermore, the combustion section water jacket and the outlet section water jacket respectively include annular water jacket cavities set at both ends of the combustion section and the outlet section. The two annular water jacket cavities are connected by a circulating water jacket, and an inlet pipe and an outlet pipe are respectively connected to the annular water jacket cavities at both ends.

[0010] Furthermore, the circulating water sleeve is provided with a partition strip, which divides the interior of the circulating water sleeve into multiple mutually separated flow chambers.

[0011] Furthermore, it also includes an annular honeycomb vortex stabilizing cavity, which is coaxially arranged inside the combustion section. The inner diameter of the annular honeycomb vortex stabilizing cavity is larger than the outer diameter of the burner shell. The annular honeycomb vortex stabilizing cavity is provided with honeycomb units. The annular honeycomb vortex stabilizing cavity is uniformly distributed with several honeycomb units arranged in a regular hexagonal grid in the circumferential direction.

[0012] Furthermore, each honeycomb unit forms an independent micro combustion chamber. Each honeycomb unit is equipped with an inclined guide plate. Multiple inclined guide plates are centrally symmetrically distributed around the axis of the honeycomb unit. The inclined guide plates are set at an angle A with the axis. The inclined guide plates guide the high-temperature airflow ejected from the outlet end. The rotating airflow in each honeycomb unit forms a vortex zone.

[0013] Furthermore, the cellular unit is provided with multiple annular steps along the axial direction. The front side of the annular step is perpendicular to the inner wall of the cellular unit, and the back side is set at an angle B to the inner wall. The ratio of the radial height to the axial width of the annular step is 1:2-1:3.

[0014] Furthermore, the tail of the honeycomb unit is provided with bidirectional return holes, namely an inner return hole and an outer return hole. The inner return hole is located on the side wall near the center, and an inclined hole is provided through the side wall of the honeycomb unit towards the root of the flame. The outer return hole is located on the side close to the water jacket, and its inlet is inclined toward the water jacket side.

[0015] Furthermore, the cellular unit is made of SiC ceramic material, and the gaps between the units are filled with a gel insulation layer.

[0016] The advantages and beneficial effects of this utility model are as follows: 1. The combustion section of the flame stabilizer sleeve provides a closed and suitable expansion space for the flame, effectively isolating the airflow disturbance in the furnace and preventing the flame from being "blown away" or "deflected"; it solves the problem of traditional burners being prone to "flameout" and "flameout" at low loads.

[0017] 2. The inclined guide vanes within the honeycomb unit guide the airflow to form a stable vortex, which, together with the micro-vortices generated by the multi-level annular steps, creates an independent "high-temperature ignition zone" within each unit. Even if the main flame fluctuates briefly, the high temperature within the vortex can continuously provide ignition energy to the flame root, acting like a "built-in ignition source," reducing the flame pulsation amplitude by more than 60%, which is particularly crucial for the stable combustion of low-calorific-value fuels.

[0018] 3. The water jacket structure within the combustion chamber of the combustion sleeve (combustion section water jacket + outlet section water jacket) utilizes circulating cooling water for forced heat dissipation. Combined with partition bars, this ensures uniform water flow distribution, strictly controlling the sleeve wall temperature below 300℃ and preventing material creep, cracking, or oxidation corrosion caused by high temperatures. Compared to designs without cooling, the sleeve's service life is extended from 6 months to 2-3 years, significantly reducing equipment replacement frequency and maintenance costs. Attached Figure Description

[0019] Figure 1 This is a cross-sectional schematic diagram of a stable swirl burner structure with an airflow constraint sleeve according to this utility model; Figure 2 This is one of the enlarged views of the cross-section of the fuel passage inside the swirl blade; Figure 3 This is an isometric view of a stable-burning swirl burner structure with an airflow constraint sleeve according to this utility model; Figure 4 This is a structural diagram of the water jacket in the combustion section of this utility model; Figure 5 This is a structural diagram of the water jacket at the outlet section of this utility model; Figure 6 This is a cross-sectional schematic diagram of the vortex-stabilized flame cavity of this utility model; Figure 7 This is a top view of the cross-section of the honeycomb unit of this utility model.

[0020] In the diagram: 1. Burner shell; 2. Inlet end; 3. Outlet end; 4. Swirl blades; 5. Flame stabilizing sleeve structure; 6. Combustion section; 7. Outlet section; 8. Contraction section; 9. Straight section; 10. Combustion section water jacket; 11. Outlet section water jacket; 12. Annular water jacket cavity; 13. Circulating water jacket; 14. Inlet pipe; 15. Outlet pipe; 16. Separating baffle; 17. Flow chamber; 18. Vortex flame stabilizing cavity; 19. Honeycomb unit ; 20. Inclined guide vane; 21. Angle A; 22. Annular step; 23. Frontal surface; 24. Backal surface; 25. Inner return hole; 26. Outer return hole; 27. Burner head shell; 28. Connecting flange; 29. ​​Rear straight pipe of burner; 30. Inlet pipe; 31. Small hole; 32. Fuel passage; 33. Fuel pipe; 34. Inlet connector; 35. Outer ring flange; 36. Gel insulation layer; 37. Inclined angle B. Detailed Implementation

[0021] The specific embodiments of this utility model will be further described below with reference to examples. These examples are only used to more clearly illustrate the technical solution of this utility model and should not be construed as limiting the scope of protection of this utility model.

[0022] A stable swirl burner structure with an airflow confinement sleeve, such as Figure 1 As shown, it includes a burner housing 1, which is a cylindrical pipe with open ends. One end is the inlet end 2 of the combustion air, and the other end is the outlet end 3 of the mixture being sprayed out and burned. Specifically, the burner housing 1 is divided into two sections. One section is the burner head housing 27, which is used to support the swirl blades 4 and the fuel inlet connector 34, and is designed with a connecting flange 28 to connect to the combustion section 6 at the rear end. The other section is the straight pipe 29 at the rear of the burner, with an air inlet pipe 30 on the wall surface, which is used to connect to an external air supply system to provide combustion air.

[0023] The cyclone separator structure includes cyclone blades 4 installed inside the outlet end 3; the cyclone blades 4 are blunt-body cyclone blades, and the combustion air is controlled to flow out evenly through multiple channels between the blades. The combustion air is mixed with the fuel injected through the small holes 31 on the cyclone blades 4 to form a uniform mixture, thereby improving combustion stability and reducing pollution.

[0024] The cyclone separator employs single-stage cyclone blades 4, with internal fuel channels 32. All blades have the same shape and size, as do the internal fuel channels 32. Figure 2As shown, small holes 31 are uniformly opened radially on the swirl blades 4 in the fuel channel 32. The small holes 31 are perpendicular to the blade surface. The number of small holes 31 is the same as the number of multiple air channels between the swirl blades 4, and they correspond one-to-one. The fuel is directly injected through the small holes 31 and mixed with the air in the swirl channel to form a uniform mixture. At the same time, the small holes 31 reduce the influence of combustion backfire. When the combustion air passes through the swirl channel, it generates a rotating airflow, which is fully mixed with the fuel and then ejected from the outlet end 3 to form the initial swirl flame.

[0025] The fuel pipe 33 includes a conduit and an inlet connector 34. The front end of the conduit is connected to the cyclone separator, and the rear end is connected to the inlet connector 34. The conduit is bent into an L-shape. The central fuel pipe 33 is located on the central axis of the burner. Its front end is connected to the fuel chamber inside the cyclone blades 4. Fuel enters the chamber, its flow velocity is reduced, and it can evenly enter the fuel channels 32 of each cyclone blade 4. Finally, it is injected through the small holes 31 into the channels between the cyclone blades 4, where it mixes with the combustion air. The fuel pipe 33 is connected to the inlet connector 34 at the outer end of the casing for connecting to an external fuel supply system. The fuel channels 32 of the cyclone blades 4 are guided through the central fuel pipe 33.

[0026] Flame-stabilizing sleeve structure 5, such as Figure 3 As shown, it has a cylindrical structure and is connected to the outlet end 3 along the axis of the burner. It includes a combustion section 6 and an outlet section 7 connected in sequence. Specifically, an outer ring flange 35 is provided on the outside of the burner head housing 27. The stable combustion sleeve structure 5 is connected and installed to the burner through the outer ring flange 35. It can be understood that a flange that matches the outer ring flange 35 is provided at the end of the combustion section 6. After the flange is connected, the fixed installation is achieved.

[0027] The inner diameter of the combustion section 6 is larger than the outer diameter of the burner shell 1 to provide expansion space for flame combustion. The front half of the outlet section 7 is a contraction section 8, and the rear half is a straight section 9. The inner diameter of the combustion section 6 is 50-100mm larger than the outer diameter of the burner shell 1. For example, when the outer diameter of the shell is 200mm, the inner diameter of the combustion section 6 is 250-300mm, providing expansion space for the flame and preventing the high-temperature flame from directly impacting the sleeve wall. The front half of the outlet section 7 is a contraction section 8 with a cone angle of 30°-45°. By reducing the diameter, the airflow velocity is increased from 15m / s to 25-30m / s, enhancing the rigidity of the flame. The rear half is a straight section 9 with a length of 50-100mm, stabilizing the airflow direction and ensuring a consistent flame injection angle.

[0028] The water jacket structure provides efficient cooling and temperature control; the water jacket structure is integrated within the wall of the flame-stabilized sleeve, such as... Figure 4 , 5 As shown, it is divided into a combustion section water jacket 10 (corresponding to combustion section 6) and an outlet section water jacket 11 (corresponding to outlet section 7). The sleeve wall temperature is controlled by forced water cooling (≤300℃) to avoid high-temperature oxidation or ablation.

[0029] The water jacket adopts a double-wall design. The inner layer, closer to the flame, is made of 3mm thick 316L stainless steel, and the outer layer is made of 5mm thick Q345R carbon steel. The two layers form a closed chamber, namely the water jacket cavity, through which cooling water is introduced to remove heat. Working principle: Cooling water enters from the inlet pipe 14 of the combustion section water jacket 10, flows along the axial direction of the sleeve, absorbs the high-temperature heat of the combustion section 6, and then exits through the outlet pipe 15 of the outlet section water jacket 11. The water temperature rise is controlled at 20~30℃, forming a circulating cooling system.

[0030] To avoid localized overheating caused by uneven water flow distribution within the water jacket cavity, both ends of the combustion section water jacket 10 and the outlet section water jacket 11 are provided with annular water jacket cavities 12, connected by a circulating water jacket 13. The annular water jacket cavities 12 are located at both ends of the combustion section 6 and the outlet section 7, serving to collect and distribute water, ensuring that cooling water is evenly distributed to the circulating water jacket 13. Furthermore, as... Figure 4 , 5 As shown, extending axially along the sleeve, an internal partition strip 16, made of the same material as the sleeve and 2mm thick, divides the sleeve into several independent flow chambers 17, which are evenly distributed circumferentially. The partition strip forces the cooling water to form an independent flow channel in each chamber, preventing water flow "short-circuiting" and keeping the sleeve wall temperature deviation within ±15℃. As one embodiment, the partition strip 16 can be arranged parallel to the axis, forming a straight flow channel in the flow chamber 17; as another embodiment, the partition strip 16 can be arranged spirally, forming a spiral flow chamber 17, allowing the cooling water to spiral around the flame-stabilized sleeve, thus enhancing heat exchange efficiency. The flame-stabilizing sleeve structure 5 is the core component of this embodiment. The flame enters the combustion section 6 of the flame-stabilizing sleeve. Due to the large inner diameter of the combustion section 6, the flame expands freely and mixes further with the air. The contraction section 8 of the outlet section 7 accelerates the airflow, enhances the flame rigidity, and the straight section 9 ensures flame direction stability. This achieves flame stability and improves combustion efficiency. It provides physical constraints and flow field control for the flame. The combustion section 6 of the flame-stabilizing sleeve provides a closed combustion space, avoiding the impact of external airflow disturbances (such as furnace negative pressure fluctuations) on the flame. Especially at low loads (≤30% of rated load), the increased flow velocity of the contraction section 8 enhances flame rigidity, solving the problems of "flameout" and "blowing out" that traditional burners easily experience at low loads. Actual tests show that after adopting this sleeve, the stable combustion load range of the burner can be widened from 40%~100% to 15%~110%, adapting to small fluctuations (±10%) in fuel pressure and calorific value. Example 2:

[0031] As an improvement, it also includes an annular honeycomb-shaped vortex-stabilized flame cavity 18, such as... Figure 6 , 7As shown, it is coaxially arranged inside the combustion section 6. The inner diameter of the annular honeycomb vortex stabilizing flame cavity 18 is larger than the outer diameter of the burner shell 1. The annular honeycomb vortex stabilizing flame cavity 18 is provided with honeycomb units 19. The annular honeycomb vortex stabilizing flame cavity 18 is coaxially arranged inside the combustion section 6. Its inner diameter is slightly larger than the outer diameter of the burner shell 1, for example, 20~30mm larger, forming an annular structure around the flame. The flame stabilization is enhanced by the "micro combustion chamber" effect of the honeycomb units 19.

[0032] The honeycomb unit 19 is arranged in a regular hexagonal array, with a side length of 15~20mm and an axial length of 100~150mm. The whole unit is sintered from SiC ceramic and has a temperature resistance of ≥1600℃. The gaps between the units are filled with an aerogel insulation layer 36 (thermal conductivity ≤0.02W / (m・K)) to reduce the transfer of heat to the water jacket. Each cellular unit 19, through the design of the inclined guide plate 20 and the annular step 22, guides the airflow to form a stable vortex and enhances turbulent mixing.

[0033] The inclined guide vanes 20 are located at the inlet of the honeycomb unit 19, near the burner outlet 3. Two to three vanes can be installed, symmetrically distributed around the center of the unit axis, with an angle A21 of 25° to 35° with the axis. When the high-temperature airflow (1200~1500℃) ejected from the outlet 3 enters the honeycomb unit 19, the guide vanes direct the airflow to the inner wall, forming a clockwise / counterclockwise rotating airflow, creating a vortex within the unit (dwelling time ≥0.5 seconds), providing a continuous ignition source for the flame.

[0034] The multi-level annular steps 22 are arranged in groups of 30-50 mm along the axial direction of the unit, and can be arranged in groups of 3-5. The radial height (1.5-3 mm) to axial width (3-6 mm) of a single step is in the ratio of 1:2 to 1:3. The frontal surface 23 (facing the inlet) is perpendicular to the inner wall, and the backal surface 24 is inclined at an angle B37 (45°-60°) to the inner wall. The corners are rounded with a radius of 0.5-1 mm.

[0035] Its working principle is as follows: when the airflow passes through the step, the front surface 23 blocks and forms a local low-pressure area, while the back surface 24 guides the airflow to form a small-scale vortex. After superimposing with the main vortex, the turbulence intensity is enhanced, which increases the mixing uniformity by 20% to 30%, promotes the secondary reaction of unburned fuel (such as CH4) with oxygen, and reduces CO emissions.

[0036] High-temperature airflow enters the honeycomb unit 19 and is guided by the inclined guide plate 20 to form a stagnant vortex. The annular step 22 enhances turbulent mixing, creating a stable high-temperature zone (1200~1400℃) within the unit, and maintaining the temperature at the flame root through thermal radiation. Example 3:

[0037] Based on Embodiment 2, a further improvement is made by providing an inner return hole 25 and an outer return hole 26 at the tail of the honeycomb unit 19, thereby achieving bidirectional adjustment of heat recovery and unit protection. Figure 6 , 7 As shown; the inner return hole 25 is located on the side wall near the center of the unit, and is an inclined hole with a diameter of 3-4 mm, forming an angle of 45° with the axis, with the opening facing the flame root (i.e., near the burner outlet end 3). The high-temperature flue gas (containing unburned H2 and CO) in the honeycomb unit 19 flows back to the flame root through this hole, replenishing ignition energy, especially at low loads (≤30%), which can prevent flame extinction. The outer return hole 26 is located on the side wall near the water jacket of the unit, with a diameter of 3-4 mm, and the opening faces the water jacket side, forming an angle of 45° with the axis. Cooling air near the water jacket enters the honeycomb unit 19 in a small amount through this hole, forming "film cooling" at the outlet, reducing the temperature at the tail of the unit and preventing ceramic ablation. The inner return hole 25 sends the high-temperature flue gas back to the flame root for reheating, while the outer return hole 26 introduces cold air to protect the tail of the unit. At the same time, the water jacket controls the sleeve wall temperature through circulating cooling to prevent overheating.

[0038] Specifically, taking a natural gas burner for an industrial boiler as an example, its specific parameters and structure are as follows: Burner shell 1: outer diameter 200mm, length 1000mm, outlet end 3 flow velocity 15m / s; Hydrocyclone structure: 10 swirl blades, 4 swirl blades, 0.5 swirls; Flame stabilizing sleeve: combustion section 6 inner diameter 250mm, length 300mm, outlet section 7 contraction section 8 cone angle 30°, straight section 9 length 80mm; Water jacket structure: the water inlet of the combustion section water jacket 10 is 2.5 m³ / h, and the water outlet temperature of the outlet section water jacket 11 is ≤50℃; Honeycomb-shaped vortex-stabilized flame chamber 18: multiple hexagonal units, SiC ceramic material, inclined guide plate 20 with included angle A21=30° inside the unit, three-stage annular step 22 (height 2mm, width 5mm, back flow surface 24 with inclination angle B=50°); bidirectional return holes: inner / outer return holes 26 with diameter 4mm, facing the flame root and water jacket side respectively.

[0039] Operational performance: Stable flame within a load range of 20%~110%, NOx emissions ≤80mg / m³, CO emissions ≤50ppm, stable combustion sleeve wall temperature ≤280℃, and service life of honeycomb unit 19 ≥3000 hours.

[0040] In this design, the flame stabilizing sleeve adopts a modular design, connecting to the burner outlet end 3 via a flange. The outlet section 7 can be replaced (adjusting the contraction cone angle or length) according to different combustion scenarios (such as industrial kilns, boilers, and heating furnaces) without altering the main burner structure. Compared to traditional external flame stabilizing devices, its axial dimension is reduced by 30%~40%, making it more suitable for space-constrained furnace environments. The flame stabilizing sleeve structure 5, through a synergistic design of "physical constraints + flow field control + thermal management optimization," fundamentally solves the pain points of traditional burners such as "poor stability, low efficiency, and short lifespan." It exhibits significant advantages, particularly in wide load adaptability, pollutant control, and equipment safety. It can be widely applied to multi-fuel combustion scenarios such as natural gas, liquefied petroleum gas, and low-calorific-value coal gas, combining economic benefits with environmental value.

[0041] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A stable-burning swirl burner structure with an airflow confinement sleeve, characterized in that, include Burner shell: It is a cylindrical pipe with open pipes at both ends. One end is the inlet of the combustion air and the other end is the outlet of the mixture for injection and combustion. The hydrocyclone structure includes swirling blades installed inside the outlet end, a fuel channel inside the swirling blades, and fuel injection holes arranged radially in the fuel channel; The stable combustion sleeve structure is cylindrical and connected to the outlet end along the axis of the burner. It includes a combustion section and an outlet section connected in sequence. The inner diameter of the combustion section is larger than the outer diameter of the burner shell to provide expansion space for flame combustion. The front half of the outlet section is a contraction section and the rear half is a straight section.

2. The stable-burning swirl burner structure with an airflow confinement sleeve according to claim 1, characterized in that, The combustion stabilizing sleeve structure has a water jacket structure inside its wall, which is divided into a combustion section water jacket and an outlet section water jacket.

3. The stable-burning swirl burner structure with an airflow confinement sleeve according to claim 2, characterized in that, The combustion section water jacket and the outlet section water jacket respectively include annular water jacket cavities set at both ends of the combustion section and the outlet section. The two annular water jacket cavities are connected by a circulating water jacket. The annular water jacket cavities at both ends are respectively connected to an inlet pipe and an outlet pipe.

4. The stable-burning swirl burner structure with an airflow confinement sleeve according to claim 3, characterized in that, The circulating water sleeve is provided with a partition strip, which divides the inside of the circulating water sleeve into multiple mutually separated flow chambers.

5. The stable-burning swirl burner structure with an airflow confinement sleeve according to claim 1, characterized in that, It also includes an annular honeycomb vortex stabilizing chamber, which is coaxially arranged inside the combustion section. The inner diameter of the annular honeycomb vortex stabilizing chamber is larger than the outer diameter of the burner shell, and honeycomb units are provided inside the annular honeycomb vortex stabilizing chamber.

6. The stable-burning swirl burner structure with an airflow confinement sleeve according to claim 5, characterized in that, Each honeycomb unit forms an independent micro combustion chamber. Each honeycomb unit is equipped with an inclined guide plate. Multiple inclined guide plates are centrally symmetrically distributed around the axis of the honeycomb unit. The inclined guide plates are set at an angle A with the axis. The inclined guide plates guide the high-temperature airflow ejected from the outlet end. The rotating airflow in each honeycomb unit forms a vortex zone.

7. The stable-burning swirl burner structure with an airflow confinement sleeve according to claim 6, characterized in that, The cellular unit is provided with multiple annular steps along the axial direction. The front side of the annular step is perpendicular to the inner wall of the cellular unit, and the back side is set at an angle B to the inner wall. The ratio of the radial height to the axial width of the annular step is 1:2-1:

3.

8. The stable-burning swirl burner structure with an airflow confinement sleeve according to claim 5, characterized in that, The tail of the honeycomb unit is provided with bidirectional return holes, namely an inner return hole and an outer return hole. The inner return hole is located on the side wall near the center, and an inclined hole is provided through the side wall of the honeycomb unit towards the root of the flame. The outer return hole is located on the side close to the water jacket, and its inlet is inclined toward the water jacket side.

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