A universal low nitrogen burner nozzle structure

Abstract

The present invention discloses a universal low-nitrogen burner nozzle structure. The nozzle structure includes: a main gas pipe, a plurality of peripheral long fuel pipes, a plurality of peripheral short fuel pipes and a central flame stabilizer; the peripheral long fuel pipe and the peripheral short fuel pipe are connected to the main gas pipe and are arranged alternately in the circumferential direction; the end of the peripheral long fuel pipe is provided with an end fuel injection hole and an end fuel injection short rod, and the root is provided with a root fuel injection hole and a root fuel injection short rod; the end of the peripheral short fuel pipe is provided with an axial fuel injection hole, and the root is provided with a circumferential fuel injection hole; the central flame stabilizer is provided at the end of the peripheral long fuel pipe, and the central flame stabilizer is provided with a swirl blade, a center hole, a transition flare and a spoiler cut. The nozzle structure of the present invention can better organize combustion and control pollutant emissions.

Description

Technical Field

[0001] The invention relates to the technical field of burners, and in particular to a universal low-nitrogen burner nozzle structure. Background Art

[0002] With the development of society, environmental problems have become increasingly prominent, and the international community has become increasingly concerned about the impact and consequences of environmental pollution. In my country, with the development of economic construction, the environmental problems caused by the large-scale use of fossil energy are particularly prominent. For this reason, the national team's environmental protection requirements are becoming increasingly stringent. The latest atmospheric emission standards have reduced the emission of pollutants such as smoke concentration, NOx, and CO. Therefore, whether it is to respond to the strict requirements of national policies on emissions, or the environmental protection needs of energy conservation and emissions caused by the large-scale use of various gases, the development of low NOx emission burners will become a key factor in resolving these contradictions. The design of the low NOx gas burner structure is particularly important for organizing combustion and reducing pollutant emissions.

[0003] The combustion head of the burner is the key core component of the entire burner. The function of this component is to mix the fuel gas and the combustion air and organize the combustion, releasing heat for actual needs. The structural form of this component determines the reliability and stability of the combustion process, as well as the speed and temperature distribution of the entire combustion area, which are all key factors affecting flue gas emissions.

[0004] The combustion modes of existing burners are divided into premixed combustion and diffusion combustion. Most of the current burners on the market use diffusion combustion. In order to ensure sufficient combustion, the burner generally adopts a design method that mixes fuel and air better. This type of combustion has a high flame temperature and a large high-temperature area, which easily produces a large amount of NOx. How to design a burner head that reduces the oxygen concentration of tail flue gas, further reduces NOx, and ensures stable and sufficient combustion is an urgent problem that research and development technicians need to solve.

[0005] Compared with the existing patent CN108386831A, the burner head structure needs to be customized to match the special furnace structure on site, or have requirements on the furnace diameter, length and other dimensions, in order to meet the national or local low nitrogen emission standards.

[0006] Therefore, there is still a need for a more reasonable and effective universal low-nitrogen burner nozzle structure to organize combustion and control pollutant emissions, so as to achieve the transformation and replacement of the existing burner head structure. Summary of the invention

[0007] The main purpose of the present invention is to provide a universal low-nitrogen burner nozzle structure, which aims to better organize combustion and control pollutant emissions, so as to realize the transformation and replacement of the existing burner head structure and achieve the purpose of reducing nitrogen oxide emissions from commonly used boiler gas burners by replacing local accessories.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A universal low-nitrogen burner nozzle structure comprises: a main gas pipe, a plurality of peripheral long fuel pipes, a plurality of peripheral short fuel pipes and a central flame stabilizer; the peripheral long fuel pipes and the peripheral short fuel pipes are connected to the main gas pipe and are alternately arranged in the circumferential direction; the end of the peripheral long fuel pipe is provided with an end fuel injection hole and an end fuel injection short rod, and the root is provided with a root fuel injection hole and a root fuel injection short rod; the end of the peripheral short fuel pipe is provided with an axial fuel injection hole, and the root is provided with a circumferential fuel injection hole; the central flame stabilizer is arranged at the end of the peripheral long fuel pipe, and the central flame stabilizer is provided with a swirl blade, a center hole, a transition expansion and a spoiler cut.

[0010] When the universal low-nitrogen burner nozzle structure is working, the air entering the burner is divided into two parts. One part of the air flows through the outer sides of the outer long fuel pipe and the outer short fuel pipe, mixes with the fuel sprayed from the end fuel injection hole and the circumferential fuel injection hole, and then enters the boiler furnace for combustion; the other part of the air flows through the central flame stabilizer, mixes with the fuel sprayed from the end fuel injection short rod and the axial fuel injection hole, and then rotates through the combined action of the swirl blades, the center hole and the spoiler cutout, and burns inside the boiler furnace; at the same time, the fuel sprayed from the root fuel injection hole and the root fuel injection short rod contacts and mixes with the air at the corresponding position, enters the boiler furnace along the outer side of the transition expansion port for combustion.

[0011] Compared with the existing technology, the present invention achieves the following beneficial effects by applying gas staged combustion technology, internal and external multi-layer swirl technology, and gas injection and flow guidance technology to the structural design of the burner:

[0012] (1) Strengthen the mixing of air and gas to make the mixing more uniform, improve combustion efficiency, and increase boiler thermal efficiency.

[0013] (2) Forming the grading of air and fuel, the fuel and air are mixed multiple times inside the entire nozzle structure to form a multi-stage flame. The flame area is divided into multiple layers, and the temperature field inside the furnace is stratified, achieving efficient combustion and reducing the flame temperature, thereby greatly reducing the emission of nitrogen oxides.

[0014] (3) The central flame stabilizer ensures the stability of the flame, thereby ensuring the reliable and stable operation of the burner, reducing the risk of flashback, and improving the safety of the burner during use.

[0015] (4) It can realize the transformation and replacement of the existing burner head structure, and achieve the purpose of reducing nitrogen oxide emissions by replacing local accessories of common boiler gas burners. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments and the description of the prior art are briefly introduced below.

[0017] Figure 1 is a cross-sectional view of a universal low-nitrogen burner nozzle structure provided by an embodiment of the present invention;

[0018] Figure 2 This is a front view of a universal low-nitrogen burner nozzle structure provided by an embodiment of the present invention;

[0019] Figure 3 It is an axonometric diagram of a universal low-nitrogen burner nozzle structure provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0021] The terms "first", "second", "third", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0022] The following is a detailed description through specific embodiments.

[0023] Please refer to Figures 1 to 3 One embodiment of the present invention provides a modified universal low-nitrogen burner nozzle structure (hereinafter referred to as the nozzle structure).

[0024] The nozzle structure of the embodiment of the present invention mainly includes a main gas pipe 1, a plurality of peripheral long fuel pipes 2, a plurality of peripheral short fuel pipes 3 and a central flame stabilizer 4. The peripheral long fuel pipes 2 and the peripheral short fuel pipes 3 are connected to the main gas pipe 1, and the central flame stabilizer 4 is arranged at the end of the peripheral long fuel pipe 2.

[0025] The main gas pipe 1 is used as a channel for gas to flow through, guiding and distributing the gas so that part of the gas enters the outer long fuel pipe 2, and the other part of the gas enters the outer short fuel pipe 3, and finally enters the boiler furnace for combustion. The central flame stabilizer 4 is used to form a flame-stabilized combustion area, adjust the flame shape, and achieve uniform distribution of high and low temperature areas, ultimately achieving the purpose of reducing nitrogen oxide emissions. Optionally, the outer long fuel pipe 2, the outer short fuel pipe 3 and the main gas pipe 1 are detachably connected, and their end structures are detachable, so that they can be replaced and adjusted according to the characteristics of different boilers to achieve the optimal effect of fuel distribution.

[0026] The outer long fuel pipe 2 and the outer short fuel pipe 3 are arranged alternately in the circumferential direction around the axis of the main gas pipe 1 to achieve a reasonable distribution of fuel in the inner and outer layers of the nozzle. The front end of the outer long fuel pipe 2 is arranged with a plurality of end fuel injection holes 5 and an end fuel injection short rod 6; the rear root is arranged with a plurality of root fuel injection holes 8 and a root fuel injection short rod 7. The front end of the outer short fuel pipe 3 is arranged with a plurality of axial fuel injection holes 9; the rear root is arranged with a plurality of circumferential fuel injection holes 10.

[0027] The central flame stabilizer 4 arranged at the end of the outer long fuel pipe 2 includes a main structure and a swirl blade 11, a center hole 12, a transition expansion 13 and a spoiler cut 14 arranged on the main structure. Among them, the center hole 12 is located in the center, and a plurality of swirl blades 11 are evenly distributed circumferentially around the center hole 12, and the spoiler cut 14 is distributed around the periphery. Optionally, the transition expansion 13 is a circle of inclined parts formed around the main structure, and the outer edge of the transition expansion 13 is serrated, and the cut in the serrated shape is the spoiler cut 14. The central flame stabilizer 4 can realize the inner, middle and outer three-layer distribution of the gas, the inner layer is a vortex-free straight jet, the middle layer is a strong swirl, and the outer layer is a turbulent flow. The flow matching between different layers can be achieved by selecting the structural parameters in the central flame stabilizer 4.

[0028] During operation, the air entering the burner is divided into two parts. One part of the air flows through the outer side of the outer long fuel pipe 2 and the outer short fuel pipe 3, mixes with the fuel sprayed from the end fuel injection hole 5 and the circumferential fuel injection hole 10, and then enters the boiler furnace for combustion; the other part of the air flows through the central flame stabilizer 4, mixes with the fuel sprayed from the end fuel injection short rod 6 and the axial fuel injection hole 9, and then rotates through the combined action of the swirl blade 11, the central hole 12 and the turbulent cutout 14, and burns inside the furnace. At the same time, the fuel gas sprayed from the root fuel injection hole 8 and the root fuel injection short rod 7 contacts and mixes with the air at the corresponding position, and enters the furnace along the outer side of the transition expansion 13 for combustion. Each combustion area is subjected to the action of airflow at various levels to produce mixing effect and shearing effect, and undergoes intense material and heat transfer, forming a stable and efficient combustion area together.

[0029] As a technical optimization solution of the present invention, the outer long fuel pipes 2 and the outer short fuel pipes 3 are arranged alternately, and the number of the outer long fuel pipes 2 and the outer short fuel pipes 3 are 2 to 4.

[0030] As a technical optimization solution of the present invention, the diameter of the end fuel injection hole 5 and the root fuel injection hole 8 is 10 to 25 mm, and the number is 2 to 6.

[0031] As a technical optimization solution of the present invention, the diameter of the end fuel injection short rod 6 and the root fuel injection short rod 7 is 3 to 15 mm, and the number is 1 to 3.

[0032] As a technical optimization solution of the present invention, the number of the swirl blades 11 is 6 to 10.

[0033] As a technical optimization solution of the present invention, the swirl angle of the swirl blade 11 is 25° to 60°.

[0034] As a technical optimization solution of the present invention, the diameter of the center hole 12 is 30 to 45 mm.

[0035] As a technical optimization solution of the present invention, the angle of the transition expansion 13 is 15° to 30°.

[0036] As a technical optimization solution of the present invention, the length of the transition expansion 13 is 20 to 35 mm.

[0037] In summary, the embodiment of the present invention discloses a universal low-nitrogen burner nozzle structure. The present invention applies gas staged combustion technology, internal and external multi-layer swirl technology, and gas injection and flow guidance technology to the structural design of the burner, and achieves the following beneficial effects:

[0038] (1) Strengthen the mixing of air and gas to make the mixing more uniform, improve combustion efficiency, and increase boiler thermal efficiency.

[0039] (2) Forming the grading of air and fuel, the fuel and air are mixed multiple times inside the entire nozzle structure to form a multi-stage flame. The flame area is divided into multiple layers, and the temperature field inside the furnace is stratified, achieving efficient combustion and reducing the flame temperature, thereby greatly reducing the emission of nitrogen oxides.

[0040] (3) The central flame stabilizer ensures the stability of the flame, thereby ensuring the reliable and stable operation of the burner, reducing the risk of flashback, and improving the safety of the burner during use.

[0041] (4) It can realize the transformation and replacement of the existing burner head structure, and achieve the purpose of reducing nitrogen oxide emissions by replacing local accessories of common boiler gas burners.

[0042] The technical solution of the present invention is described in detail above through specific embodiments. In the above embodiments, the description of each embodiment has its own emphasis. For the part that is not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0043] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. A person skilled in the art may modify the technical solutions described in the above embodiments, or replace some of the technical features therein by equivalents; and these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. A universal low nitrogen burner nozzle structure, characterized in that: include: A main gas pipe (1), a plurality of peripheral long fuel pipes (2), a plurality of peripheral short fuel pipes (3) and a central flame stabilizer (4); The peripheral long fuel pipe (2) and the peripheral short fuel pipe (3) are connected to the main gas pipe (1) and are arranged alternately in the circumferential direction; The end of the outer long fuel pipe (2) is provided with an end fuel injection hole (5) and an end fuel injection short rod (6), and the root is provided with a root fuel injection hole (8) and a root fuel injection short rod (7); The end of the peripheral short fuel pipe (3) is provided with an axial fuel injection hole (9), and the root is provided with a circumferential fuel injection hole (10); The central flame stabilizer (4) is arranged at the end of the outer long fuel pipe (2), and the central flame stabilizer (4) comprises a main structure and a swirl blade (11) arranged on the main structure, a central hole (12), a transition expansion (13) and a spoiler cutout (14), wherein the transition expansion (13) is a circle of inclined parts formed around the main structure, and the outer edge of the transition expansion (13) is serrated, and the cutout in the serrated shape is the spoiler cutout (14).

2. The universal low nitrogen burner nozzle structure according to claim 1, characterized in that: During operation, the air entering the burner is divided into two parts. One part of the air flows through the outer sides of the outer long fuel pipe (2) and the outer short fuel pipe (3), mixes with the fuel sprayed from the end fuel injection hole (5) and the circumferential fuel injection hole (10), and then enters the boiler furnace for combustion; the other part of the air flows through the central flame stabilizer (4), mixes with the fuel sprayed from the end fuel injection short rod (6) and the axial fuel injection hole (9), and then rotates through the combined action of the swirl blade (11), the central hole (12) and the turbulent cutout (14), and burns inside the boiler furnace; at the same time, the fuel sprayed from the root fuel injection hole (8) and the root fuel injection short rod (7) contacts and mixes with the air at the corresponding position, and enters the boiler furnace along the outer side of the transition expansion (13) for combustion.

3. The universal low nitrogen burner nozzle structure according to claim 1, characterized in that: The peripheral long fuel pipe (2) and the peripheral short fuel pipe (3) are both detachably connected to the main gas pipe (1).

4. The universal low nitrogen burner nozzle structure according to claim 1, characterized in that: On the central flame stabilizer (4), the central hole (12) is located in the center, a plurality of swirl blades (11) are evenly distributed circumferentially around the central hole (12), and the turbulent cutouts (14) are distributed on the periphery.

5. The universal low nitrogen burner nozzle structure according to claim 1, characterized in that: The number of the peripheral long fuel pipes (2) and the number of the peripheral short fuel pipes (3) are both 2-4.

6. The universal low nitrogen burner nozzle structure according to claim 1, characterized in that: The diameters of the end fuel injection holes (5) and the root fuel injection holes (8) are 10 to 25 mm, and the number of the holes is 2 to 6.

7. The universal low nitrogen burner nozzle structure according to claim 1, characterized in that: The diameter of the end fuel injection short rod (6) and the root fuel injection short rod (7) is 3 to 15 mm, and the number of the short rods is 1 to 3.

8. The universal low nitrogen burner nozzle structure according to claim 1, characterized in that: The number of the swirl blades (11) is 6 to 10, and the swirl angle is 25° to 60°.

9. The universal low nitrogen burner nozzle structure according to claim 1, characterized in that: The diameter of the central hole (12) is 30-45 mm.

10. The universal low nitrogen burner nozzle structure according to claim 1, characterized in that: The transition expansion (13) has an angle of 15° to 30° and a length of 20 to 35 mm.

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