Low-nitrogen internal combustion burner head structure and burner

Abstract

The utility model discloses a kind of low-nitrogen inner-burning combustor head structure and combustor, including combustion head and the flame tube being set in combustion head. The combustion head is enclosed to form air inlet cavity with flame tube, and the combustion cavity is formed in the center of the flame tube;The flame tube includes multiple annular corrugated sheets and annular flat sheets alternately stacked along the axial direction, and the wave crest, wave trough of the annular corrugated sheet is formed with multiple air holes for communicating the combustion cavity and the air inlet cavity between adjacent annular flat sheets;The annular corrugated sheet and annular flat sheet are all tapered surface ring structure gradually tapered from back to front along the axial direction;The extension direction of the air hole forms an included angle with the radial direction of the annular corrugated sheet. The structure is simple in design, low-nitrogen emission can be realized without external FGR, and long flame can be formed to adapt to long hearth.

Description

Technical Field

[0001] This utility model relates to the field of burner technology, and in particular to a low-NOx internal combustion burner head structure and burner. Background Technology

[0002] Industrial burners are core components of various boilers, heating furnaces, and other thermal equipment, and their performance directly affects the equipment's thermal efficiency, pollutant emission levels, and operating costs. Reducing NOx emissions generated during combustion is a critical issue that the industry urgently needs to address.

[0003] Currently, one of the mainstream technical approaches to achieving low-NOx combustion is flue gas recirculation (FGR). This method mixes some low-temperature flue gas into the combustion air, suppressing NOx formation by reducing the temperature and oxygen concentration in the combustion zone. However, FGR technology has significant drawbacks: firstly, the system requires additional flue gas ducts, induced draft fans, and control systems, resulting in complex equipment structures, large footprints, and high initial investment costs; secondly, the introduced flue gas can adversely affect combustion stability, increasing the risk of flameout, especially under load fluctuations.

[0004] Another approach is to optimize the burner head structure itself, enhancing fuel-air mixing to achieve efficient and uniform combustion, thereby controlling NOx formation at its source. Some low-NOx burners on the market use complex flow channels or multi-stage air distribution to promote mixing, but these structures often suffer from excessive airflow resistance, manufacturing difficulties, and high costs. Furthermore, many existing low-NOx burners, in pursuit of low emissions, often sacrifice flame intensity and length, resulting in uncontrollable flame shape and weak penetration, making them unsuitable for industrial furnace applications such as steel rolling mills and large boilers that require long flames. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the above-mentioned problems and provide a low-NOx internal combustion burner head structure and burner that is simple in structure, can achieve low NOx emissions without external FGR, and can form a long flame to adapt to a long furnace.

[0006] The technical solution of this utility model is: The present invention discloses a low-NOx internal combustion burner head structure, comprising a burner head and a flame tube disposed within the burner head, characterized in that: an air intake chamber is formed between the burner head and the flame tube, and a combustion chamber is formed at the center of the flame tube; the flame tube comprises a plurality of annular corrugated plates and annular flat plates alternately stacked along the axial direction, and the crests and troughs of the annular corrugated plates form a plurality of air holes between adjacent annular flat plates for communicating the combustion chamber and the air intake chamber; Both the annular corrugated sheet and the annular flat sheet are conical ring structures that gradually taper from back to front along the axial direction; the extension direction of the air hole forms an angle with the radial direction of the annular corrugated sheet.

[0007] Furthermore, in the low-NOx internal combustion burner head structure of this utility model, the angle between the generatrix of the conical ring structure and the axis of the flame tube is 15°-45°. This conical angle design can guide the gas mixture to be injected forward, providing axial momentum for the flame.

[0008] Furthermore, in the low-NOx internal combustion burner head structure of this utility model, the angle between the extension direction of the air hole and the radial direction of the annular corrugated sheet is 10°-20°. This deflection angle causes the airflow to generate a strong tangential rotation component when it is ejected, forming a swirling flow and enhancing the mixing effect.

[0009] Furthermore, in the low-NOx internal combustion burner head structure described in this utility model, the corrugations of the multiple annular corrugated plates are in the same phase, and the peaks and troughs of each annular corrugated plate are axially aligned. This design ensures that all air holes are axially aligned, forming a continuous and regular airflow channel, resulting in a more uniform and stable airflow organization.

[0010] Furthermore, in the low-NOx internal combustion burner head structure of this utility model, multiple axially extending limiting rods are distributed circumferentially within the air intake chamber. These limiting rods collectively divide the air intake chamber into multiple independent regions. The inner sidewalls of the limiting rods contact the outer peripheral walls of the annular corrugated plates and annular flat plates, serving to radially limit the flame tube. The limiting rods not only support and ensure the concentricity of the flame tube but also divide the annular air intake chamber into multiple independent regions, effectively preventing airflow deviation within the air intake chamber and ensuring the uniformity of circumferential air intake.

[0011] Furthermore, in the low-NOx internal combustion burner head structure described in this utility model, the annular corrugated plate and the annular flat plate are connected as a whole by multiple spaced positioning pins. This structure ensures the rigidity and integrity of the entire flame tube stack structure, preventing it from deforming or misaligning under high temperature and airflow impact.

[0012] This utility model also discloses a burner, including a premixer and a low-NOx internal combustion burner head structure as described above. The outlet of the premixer is connected to the inlet of the air inlet chamber of the head structure, and the flow area of ​​the air inlet chamber is smaller than the flow area of ​​the premixer outlet. This design increases the flow velocity and rectifyes the mixed gas when it enters the head, thereby increasing the flame length and making the flame shape stable and controllable.

[0013] The beneficial effects of this utility model are: 1. This utility model incorporates a corrugated layered sheet structure in the head, with the direction of its air vents extending at an angle to the radial direction. It forms a large number of tiny, orderly and directional swirling channels, which efficiently divide the gas mixture into countless fine airflows. Under the strong swirling action, it achieves the ultimate and uniform mixing of gas and air at the microscale, which greatly suppresses the generation of thermal NOx. It can stably reduce NOx to below 30mg / m³ without the need for an external FGR, simplifying the system structure and reducing manufacturing and maintenance costs.

[0014] 2. This utility model provides significant axial thrust for the mixed airflow by setting the stacked annular plates as a conical ring structure that gradually shrinks from back to front along the axial direction. Combined with the accelerated swirling flow, it can form a strong flame with a length of 0.9-1.5m. The flame has a long thrust and is perfectly adapted to various long furnace application scenarios, solving the problem of traditional burners having flames that are too short or have uncontrollable shapes.

[0015] 3. This structure combines independent intake areas divided by limiting rods with corrugated laminates with consistent phase, ensuring that the air-fuel mixture is evenly distributed to every pore in both the circumferential and axial directions, avoiding the generation of local high-temperature points, and ensuring low nitrogen effect and combustion stability. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the axial section of the burner of this utility model.

[0017] Figure 2 This is a radial section diagram of the present invention.

[0018] Figure 3 This is a schematic diagram of the three-dimensional structure of a ring-shaped corrugated sheet. Detailed Implementation

[0019] The present invention will now be further described with reference to the accompanying drawings: Reference Figures 1-3 As shown in the figure, the low-NOx internal combustion burner head structure described in this embodiment includes a burner head 1 and a flame tube 2 disposed within the burner head 1. The burner head 1 and the flame tube 2 enclose an air intake chamber 3, and a combustion chamber 4 is formed at the center of the flame tube 2.

[0020] The flame tube 2 is the core component, including multiple annular corrugated sheets 21 and annular flat sheets 22 that are alternately stacked along the axial direction. The annular corrugated sheets 21 and annular flat sheets 22 are both conical ring structures that gradually shrink from back to front along the axial direction. The angle between their generatrices and the axis of the flame tube 2 is 15°-45°, preferably 30°.

[0021] The annular corrugated sheets have alternating peaks and troughs, and the corrugations of multiple annular corrugated sheets 21 are in phase, ensuring that when stacked, the peaks and troughs of each annular corrugated sheet 21 are axially aligned. The peaks and troughs of each annular corrugated sheet 21 form multiple air holes (not shown in the figure) connecting the combustion chamber 4 and the intake chamber 3 between adjacent annular flat sheets 22. These air holes are formed by the corrugated surface of the annular corrugated sheets 21, and their extension direction naturally forms an acute angle with the radial direction of the annular corrugated sheets 21, which is 10°-20°, preferably 15°. This design imparts a tangential velocity to the airflow passing through the air holes, causing it to rotate.

[0022] To ensure structural stability, multiple axially extending limiting rods 5 are uniformly welded along the circumferential direction inside the air intake chamber 3. These limiting rods 5 collectively divide the air intake chamber 3 into multiple independent areas, forcing the airflow to be evenly distributed. The inner wall of the limiting rod 5 contacts the outer peripheral wall of the annular corrugated plate 21 and the annular flat plate 22, serving to radially limit the flame tube 2 and prevent the flame tube 2 from becoming eccentric. The limiting rods 5 can be fixed to the flame tube 2 by welding.

[0023] Furthermore, all the annular corrugated sheets 21 and annular flat sheets 22 are connected by multiple spaced positioning pins 6. The two ends of the positioning pins 6 can be fixed by riveting, thereby pressing and fixing all the sheets into a whole, ensuring that the sheets will not loosen or misalign under long-term high-temperature operation and airflow impact. In addition, preferably, the positioning pins 6 and the limiting rods 5 can be arranged in a staggered manner.

[0024] This embodiment also provides a burner, including a premixer 7 and a low-NOx internal combustion burner head structure as described above. The outlet of the premixer 7 is connected to the inlet of the air inlet chamber 3 of the head structure, and the inlet flow area of ​​the air inlet chamber 3 is smaller than the outlet flow area of ​​the premixer 7.

[0025] The working principle of this embodiment is as follows: After the gas and air are initially mixed in the premixer 7, the gas flows out from the outlet of the premixer 7. Since the inlet area of ​​the intake chamber 3 is smaller than the outlet area of ​​the premixer, the airflow is accelerated and enters each independent area of ​​the intake chamber 3. Subsequently, during the axial flow, the airflow gains forward momentum under the guidance of the conical structure and disperses into each axially aligned air hole composed of annular corrugated plates 21 and annular flat plates 22 with consistent phase. When passing through the air hole, the airflow is affected by the deflection angle, forming a high-speed rotating jet that enters the combustion chamber 4, thereby intensifying the mutual collision and mixing between the airflows, resulting in a more uniform mixture. After the mixture is ignited, under the combined action of strong swirling flow and axial thrust, a flame with controllable length is formed, and ultra-low nitrogen emissions are achieved in highly uniform combustion, with NOx emissions below 30 mg / m³, and the flame distance can be pushed to 0.9-1.5 m.

[0026] The specific embodiments described herein are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model are still covered by the claims of this utility model.

Claims

1. A low-NOx internal combustion burner head structure, comprising a burner head and a flame tube disposed within the burner head, characterized in that: The combustion head and the flame tube enclose an air intake chamber, and the center of the flame tube forms a combustion chamber. The flame tube includes multiple annular corrugated plates and annular flat plates that are alternately stacked along the axial direction. The crests and troughs of the annular corrugated plates form multiple air holes between the adjacent annular flat plates to connect the combustion chamber and the air intake chamber. Both the annular corrugated sheet and the annular flat sheet are conical ring structures that gradually taper from back to front along the axial direction; the extension direction of the air hole forms an angle with the radial direction of the annular corrugated sheet.

2. The low-NOx internal combustion burner head structure according to claim 1, characterized in that: The angle between the generatrix of the conical ring structure and the axis of the flame tube is 15°-45°.

3. The low-NOx internal combustion burner head structure according to claim 1, characterized in that: The angle between the extension direction of the pores and the radial direction of the annular corrugated sheet is 10°-20°.

4. The low-NOx internal combustion burner head structure according to claim 1, characterized in that: The corrugations of the multiple annular corrugated sheets are in the same phase, and the crests and troughs of each annular corrugated sheet are axially aligned.

5. The low-NOx internal combustion burner head structure according to claim 1, characterized in that: The air intake chamber has multiple axially extending limiting rods distributed around its circumference, which together divide the air intake chamber into multiple independent areas; the inner sidewall of the limiting rod contacts the outer peripheral wall of the annular corrugated plate and the annular flat plate, and is used to limit the radial movement of the flame tube.

6. The low-NOx internal combustion burner head structure according to claim 1, characterized in that: The annular corrugated sheet and the annular flat sheet are connected as one unit by multiple spaced positioning pins.

7. A burner, characterized in that: The device includes a premixer and a low-NOx internal combustion burner head structure as described in any one of claims 1-6, wherein the outlet of the premixer is connected to the inlet of the air intake chamber of the head structure, and the flow area of ​​the air intake chamber inlet is smaller than the flow area of ​​the premixer outlet.

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