Air supply structure suitable for flue gas internal circulation gas burner and burner
By designing swirl blades and flue gas mixing structures in the gas burner, the problems of complex burner structure and unstable combustion are solved, achieving a reduction in NOx emissions and improved combustion stability, and making it suitable for a variety of gaseous fuels.
Patent Information
- Application Number
- CN202511288825.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-10
- Publication Date
- 2025-12-09
AI Technical Summary
Existing gas burners have complex structures and unstable combustion, resulting in high NOx emission levels, which limits the large-scale application of flue gas recirculation burners.
An air supply structure suitable for flue gas recirculation gas burners is designed, including a central fuel passage, an air passage, a main fuel passage, a flue gas inlet, a main fuel air passage, and a central fuel air passage. By setting swirl blades to form cross jets, the mixing of fuel and air is promoted, and the oxygen concentration is diluted by mixing with flue gas before the fuel comes into contact with the air.
It simplifies the burner structure, stabilizes the combustion process, reduces NOx emissions, and is suitable for a variety of gaseous fuels, including natural gas, hydrogen, and ammonia, and can be used with single or mixed fuels.
Smart Images
Figure CN121089072A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of combustion equipment technology, and more specifically to an air supply structure and burner suitable for flue gas recirculation gas burners. Background Technology
[0002] A gas burner is an industrial thermal energy device that uses gas as fuel and achieves efficient combustion through premixed air. In a broader sense, it also includes household gas appliances, but is primarily used in industrial production. Its core function is to mix gas and air in a specific ratio, ignite the mixture, and stably output heat energy to boilers and other equipment. This device employs a ring-shaped nozzle, a dual-air-duct make-up air system, and a three-stage air intake structure, improving combustion efficiency and safety through staged air supply. The main structure is available in split and integrated types. The split type is suitable for large industrial applications, and the combustion zone uses heat-resistant stainless steel to extend its service life.
[0003] In recent years, with increasing environmental awareness, gaseous fuels have gradually gained popularity due to their lower pollutant emissions compared to solid and liquid fuels. Among the various methods of using gaseous fuels, flue gas recirculation is recognized as a highly efficient combustion method, but its large-scale application is limited by its high NOx emissions. Furthermore, existing gas burners have relatively complex structures and exhibit combustion instability during practical use. Summary of the Invention
[0004] Therefore, the technical problem to be solved by the present invention is to overcome the problem that the structure of the gas burner in the prior art is relatively complex and that the combustion is unstable in actual use, so as to provide an air supply structure and burner suitable for flue gas internal circulation gas burners.
[0005] To address the aforementioned technical problems, this invention provides an air supply structure suitable for a flue gas recirculation combustion burner, comprising: a central fuel passage, an air passage, a main fuel passage, a flue gas inlet, a main fuel-air passage, a central fuel-air passage, a main fuel-air blade, a central fuel-air flare, and a central fuel-air blade; the central fuel passage, air passage, and main fuel passage are arranged sequentially from the inside to the outside along the central axis of the burner, with multiple main fuel passages evenly distributed around the air passages; the main fuel-air passage and the central fuel-air passage are located downstream of the air passages; the flue gas inlet is located between the air passage outlet and the main fuel-air passage inlet; the main fuel-air blade is located within the main fuel-air passage, with an angle of 30°-60° between the main fuel-air blade and the central axis; the central fuel-air flare is located at the end of the main fuel-air passage; and the central fuel-air blade is located within the central fuel-air passage, with an angle of 30°-60° between the central fuel-air blade and the central axis.
[0006] Furthermore, the width of the central fuel air blade is smaller than the radius of the central fuel passage.
[0007] Furthermore, the angle between the edge of the central fuel air vent and the central axis is 30°-75°.
[0008] Furthermore, an inner sleeve is provided between the main fuel air passage and the central fuel air passage.
[0009] Furthermore, the width of the main fuel air blade is smaller than the radius of the inner sleeve.
[0010] Furthermore, the central fuel passage and air passage are arranged coaxially.
[0011] Furthermore, the air passage outlet is provided with a constriction, and the angle between the constriction and the central axis is less than 45°.
[0012] Furthermore, the number of main fuel channels ranges from 3 to 16.
[0013] Furthermore, the flow area of the flue gas inlet is smaller than the flow area of the air passage.
[0014] The present invention also provides a flue gas recirculation gas burner, including the air supply structure described above suitable for a flue gas recirculation gas burner.
[0015] The technical solution of this invention has the following advantages: The present invention provides an air supply structure suitable for a flue gas recirculation combustion burner, comprising: a central fuel passage, an air passage, a main fuel passage, a flue gas inlet, a main fuel air passage, a central fuel air passage, a main fuel air blade, a central fuel air flare, and a central fuel air blade; the central fuel passage, air passage, and main fuel passage are arranged sequentially from the inside to the outside along the central axis of the burner, with multiple main fuel passages evenly distributed around the air passages, and the main fuel air passage and central fuel air passage arranged downstream of the air passages, the flue gas inlet being located between the air passage outlet and the main fuel air passage inlet, the main fuel air blade being located within the main fuel air passage with an angle of 30°-60° to the central axis, the central fuel air flare being located at the end of the main fuel air passage, and the central fuel air blade being located within the central fuel air passage with an angle of 30°-60° to the central axis.
[0016] By arranging a central fuel passage, an air passage, and a main fuel passage along the central axis, and setting a main fuel air passage and a central fuel air passage downstream of the air passage, it is convenient to place the flue gas inlet between the air passage outlet and the main fuel air passage inlet. At the same time, the angle between the main fuel air blade 7 and the central axis is 30°-60°, the central fuel air flare is set at the end of the main fuel air passage, and the angle between the central fuel air blade and the central axis is 30°-60°. The central fuel air blade and the main fuel air blade 7 form a swirl blade, supplying the air required for the combustion of the central fuel and the main fuel separately, which can make the air and fuel form a cross jet, accelerate the mixing process of the two, and is more conducive to stable combustion.
[0017] This air supply structure, applicable to flue gas recirculation gas burners, supplies air between the main fuel passage and the central fuel passage, providing oxygen for the combustion of both the main fuel and the central fuel simultaneously, thus reducing the complexity of the burner. This air supply structure, applicable to flue gas recirculation gas burners, is relatively simple. Before contacting the fuel, the air is mixed with the flue gas, which dilutes the oxygen concentration in the air, slows down the mixing rate of oxygen and fuel, thereby reducing the flame temperature and effectively suppressing the formation of thermal NOx. This air supply structure, applicable to flue gas recirculation gas burners, is a new type of gas combustion equipment for reducing NOx emissions. It can be applied to burners of different gaseous fuels such as natural gas, hydrogen, and ammonia, and is suitable for both single fuels and mixed fuels.
[0018] The summary section is provided to present the chosen concepts in a simplified form, which will be further described in the detailed description below. The summary section is not intended to identify essential or necessary features of this disclosure, nor is it intended to limit the scope of this disclosure. Attached Figure Description
[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0020] Figure 1 A schematic diagram of the air supply structure for a flue gas recirculation gas burner provided by the present invention; Figure 2 Provided by the present invention Figure 1 Side view.
[0021] Explanation of reference numerals in the attached figures: 1. Central fuel passage; 2. Air passage; 3. Main fuel passage; 4. Flue gas inlet; 5. Main fuel air passage; 6. Central fuel air passage; 7. Main fuel air blade; 8. Central fuel air flare; 9. Central fuel air blade; 10. Inner sleeve. Detailed Implementation
[0022] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this disclosure. Therefore, the drawings and description are to be considered exemplary in nature and not restrictive.
[0023] In the description of this disclosure, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.
[0024] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joint" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or connections that allow for communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.
[0025] In this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0026] The following disclosure provides numerous different embodiments or examples for implementing various structures of this disclosure. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this disclosure. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this disclosure, but those skilled in the art will recognize the application of other processes and / or the use of other materials.
[0027] The preferred embodiments of this disclosure are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.
[0028] Please see Figures 1 to 2 As shown, the present invention provides an air supply structure suitable for a flue gas recirculation gas burner, comprising: a central fuel passage 1, an air passage 2, a main fuel passage 3, a flue gas inlet 4, a main fuel air passage 5, a central fuel air passage 6, a main fuel air blade 7, a central fuel air vent 8, and a central fuel air blade 9; the central fuel passage 1, the air passage 2, and the main fuel passage 3 are arranged sequentially from the inside to the outside along the central axis of the burner. Multiple main fuel passages 3 are evenly distributed around the air passage 2. The main fuel air passage 5 and the central fuel air passage 6 are located downstream of the air passage 2. The flue gas inlet 4 is located between the outlet of the air passage 2 and the inlet of the main fuel air passage 5. The main fuel air blade 7 is located within the main fuel air passage 5, with an angle of 30°-60° between the main fuel air blade 7 and the central axis. The central fuel air vent 8 is located at the end of the main fuel air passage 5. The central fuel air blade 9 is located within the central fuel air passage 6, with an angle of 30°-60° between the central fuel air blade 9 and the central axis.
[0029] By arranging a central fuel channel 1, an air channel 2, and a main fuel channel 3 along the central axis, and setting a main fuel air channel 5 and a central fuel air channel 6 downstream of the air channel 2, it is convenient to place the flue gas inlet 4 between the outlet of the air channel 2 and the inlet of the main fuel air channel 5. At the same time, the angle between the main fuel air blade 7 and the central axis is 30°-60°, the central fuel air vent 8 is located at the end of the main fuel air channel 5, and the angle between the central fuel air blade 9 and the central axis is 30°-60°. The central fuel air blade 9, together with the main fuel air blade 7, forms a swirl blade, supplying the air required for the combustion of the central fuel and the main fuel separately, which can make the air and fuel form a cross jet, accelerate the mixing process of the two, and is more conducive to stable combustion.
[0030] This air supply structure, applicable to flue gas recirculation gas burners, supplies air between the main fuel passage 3 and the central fuel passage 1, which can simultaneously provide oxygen for the combustion of the main fuel and the central fuel, reducing the complexity of the burner. This air supply structure, applicable to flue gas recirculation gas burners, is relatively simple. Before contacting the fuel, the air is mixed with the flue gas, which dilutes the oxygen concentration in the air, slows down the mixing rate of oxygen and fuel, thereby reducing the flame temperature and effectively suppressing the formation of thermal NOx. This air supply structure, applicable to flue gas recirculation gas burners, is a new type of gas combustion equipment for reducing NOx emissions. It can be applied to burners of different gaseous fuels such as natural gas, hydrogen, and ammonia, and is suitable for both single fuels and mixed fuels.
[0031] Among them, the central fuel channel 1 and air channel 2 are single channels, while the main fuel channel 3 is a multi-channel channel with 3-16 channels, and multiple main fuel channels 3 are evenly distributed around the air channel.
[0032] In this embodiment, the main fuel channel 3 has 6 channels.
[0033] In some alternative embodiments, the width of the central fuel air blade 9 is smaller than the radius of the central fuel passage 1, thereby facilitating the installation of the central fuel air blade 9 within the central fuel passage 1.
[0034] Specifically, the angle between the edge of the central fuel air vent 8 and the central axis is 30°-75°. This arrangement ensures the installation stability of the central fuel air vent 8 and facilitates the flow of central fuel from it, avoiding excessively large or small angles that could affect the flow rate of the central fuel.
[0035] In this embodiment, an inner sleeve 10 is provided between the main fuel air passage 5 and the central fuel air passage 6. The width of the main fuel air blade 7 is smaller than the radius of the inner sleeve 10, which facilitates the installation of the main fuel air blade 7 on the inner sleeve 10.
[0036] The central fuel passage 1 and the air passage 2 are coaxially arranged to ensure their coaxiality. In addition, the main fuel air passage 5 and the central fuel air passage 6 are arranged downstream of the air passage along the fluid flow direction. The main fuel air passage 5 and the central fuel air passage 6 are separated by an inner sleeve.
[0037] In some alternative embodiments, the air passage 2 outlet is provided with a constriction, the angle between the constriction and the central axis being less than 45°.
[0038] Meanwhile, the flue gas inlet 4 is located between the outlet of the air passage 2 and the inlet of the main fuel air passage 5, and the flow area of the flue gas inlet 4 is smaller than that of the air passage 2.
[0039] Furthermore, the nozzles of the entire flue gas recirculation gas burner must be made of high-temperature resistant materials, such as 316 stainless steel.
[0040] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.
Claims
1. An air supply structure suitable for a flue gas recirculation gas burner, characterized in that, include: The central fuel passage (1), air passage (2), main fuel passage (3), flue gas inlet (4), main fuel air passage (5), central fuel air passage (6), main fuel air blade (7), central fuel air vent (8), and central fuel air blade (9); Along the central axis of the burner, from the inside out, there are a central fuel passage (1), an air passage (2), and a main fuel passage (3). There are multiple main fuel passages (3), which are evenly distributed around the air passage (2). Downstream of the air passage (2), there are a main fuel air passage (5) and a central fuel air passage (6). The flue gas inlet (4) is located between the outlet of the air passage (2) and the inlet of the main fuel air passage (5). The main fuel air blade (7) is located inside the main fuel air passage (5). The angle between the main fuel air blade (7) and the central axis is 30°-60°. The central fuel air vent (8) is located at the end of the main fuel air passage (5). The central fuel air blade (9) is located inside the central fuel air passage (6). The angle between the central fuel air blade (9) and the central axis is 30°-60°.
2. The air supply structure for a flue gas recirculation gas burner according to claim 1, characterized in that, The width of the central fuel air blade (9) is smaller than the radius of the central fuel passage (1).
3. The air supply structure for a flue gas recirculation gas burner according to claim 2, characterized in that, The angle between the edge of the central fuel air vent (8) and the central axis is 30°-75°.
4. The air supply structure for a flue gas recirculation gas burner according to claim 3, characterized in that, An inner sleeve (10) is provided between the main fuel air passage (5) and the central fuel air passage (6).
5. The air supply structure for a flue gas recirculation gas burner according to claim 4, characterized in that, The width of the main fuel air blade (7) is smaller than the radius of the inner sleeve (10).
6. An air supply structure suitable for a flue gas recirculation gas burner according to any one of claims 1-5, characterized in that, The central fuel passage (1) and air passage (2) are arranged coaxially.
7. An air supply structure suitable for a flue gas recirculation gas burner according to claim 6, characterized in that, The air passage (2) has a constriction at the outlet, and the angle between the constriction and the central axis is less than 45°.
8. An air supply structure suitable for a flue gas recirculation gas burner according to claim 7, characterized in that, The number of channels in the main fuel channel (3) is 3-16.
9. The air supply structure for a flue gas recirculation gas burner according to claim 1, characterized in that, The flow area of the flue gas inlet (4) is smaller than that of the air passage (2).
10. A flue gas recirculation gas burner, characterized in that, The air supply structure for a flue gas recirculation gas burner, as described in any one of claims 1-9.