Micro-mixing pure hydrogen burner

Abstract

The utility model discloses a micro-mixing pure hydrogen burner, and belongs to the technical field of hydrogen burners. The problems that tempering is prone to occurring in pure hydrogen combustion of an existing combustor, and the emission amount of nitric oxide is high are solved. The device specifically comprises an air pipeline, a hydrogen pipeline, a mixing pipeline and a combustion head, an air flow channel is formed in the air pipeline, the outer side of the air pipeline is sleeved with a hydrogen pipeline, and an interlayer between the air pipeline and the hydrogen pipeline is a hydrogen flow channel; the end, provided with the mixing pipeline, of the air pipeline is connected with a combustion head. And the hydrogen flow channel and the air flow channel in the combustion head part are communicated through a mixing pipeline. According to the utility model, the hydrogen pipeline is wrapped outside the air pipeline, hydrogen is introduced into the air pipeline through the mixing pipeline to complete mixing, and under the high-speed flow of air in the air pipeline, the premixing degree is high, the hydrogen combustion efficiency is high, and the NOx emission is lower; in addition, flames generated by the air pipeline are small, and the backfire risk in the combustion process is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of hydrogen burners, in particular to a micro-mixed pure hydrogen burner. Background Art

[0002] As people are increasingly concerned about global climate change, low-carbon development has become an urgent requirement in the energy sector. Faced with the trend of energy transformation and development with the "dual carbon" goal, the gradual shift from fossil energy to low-carbon / zero-carbon and other clean energy is the general trend. Hydrogen, as an efficient and clean energy, has the advantages of wide sources, high calorific value and zero emissions. It has received widespread attention and in-depth research and can be used as a carbon-free alternative fuel for burners. At present, the commercial application of hydrogen burners in my country is not yet mature, and most of them use hydrogen mixed with natural gas as fuel, which is not suitable for the combustion of pure hydrogen fuel.

[0003] Hydrogen is a flammable and explosive dangerous gas, so when using it as a fuel, it is necessary to pay great attention to the design of the burner. In order to avoid the flashback problem caused by the rapid combustion of hydrogen, the existing hydrogen burners currently mostly use non-premixed combustion mode for hydrogen combustion; but since hydrogen has a high adiabatic combustion temperature, non-premixed combustion will cause the temperature in the combustion area to be too high, and more nitrogen oxides will be produced, while the outlet temperature field uniformity is poor. In addition, since the combustion speed of hydrogen is relatively high and the flame combustion position is close to the nozzle, there is a risk of ablating the nozzle in the combustion method. The premixed combustion technology is conducive to reducing local high-temperature areas and can reduce nitrogen oxide emissions, so the utility model designs a burner that can ensure reliable and stable combustion of hydrogen under premixed conditions. Utility Model Content

[0004] In view of the deficiencies in the prior art, the utility model provides a micro-mixed pure hydrogen burner, which solves the problems of easy backfire and high nitrogen oxide emission during pure hydrogen combustion in the prior burner.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0006] A micro-mixed pure hydrogen burner comprises an air pipeline, a hydrogen pipeline, a mixing pipeline and a combustion head; the interior of the air pipeline is an air flow channel, the outer side of the air pipeline is sleeved with a hydrogen pipeline, and the interlayer between the air pipeline and the hydrogen pipeline is a hydrogen flow channel; one end of the air pipeline is connected to the combustion head; the hydrogen flow channel and the air flow channel in the combustion head are connected through the mixing pipeline.

[0007] In this scheme, the air pipeline is the center, and the hydrogen pipeline is wrapped outside it. The hydrogen is introduced into the air pipeline through the mixing pipeline to complete the mixing, so that the premixing of hydrogen and air is achieved. In addition, under the high-speed flow of air inside the air pipeline, the premixing degree is high, the hydrogen combustion efficiency is higher, and NO xThe emissions are lower; and the flame produced by the air duct is smaller than the swirl flame produced by the traditional swirl burner, which reduces the risk of flashback during combustion.

[0008] Furthermore, the combustion head includes a plurality of air branch pipes, and the plurality of air branch pipes are connected to the air pipe; an equal number of hydrogen branch pipes are respectively provided on the outer sides of the plurality of air branch pipes, and the plurality of hydrogen branch pipes are connected to the hydrogen pipe; each group of hydrogen branch pipes and air branch pipes are connected through a plurality of mixing pipes; the end of the air branch pipe away from the air pipe is an air nozzle.

[0009] In this scheme, multiple groups of small-diameter air branch pipelines and hydrogen branch pipelines are designed, each group is equivalent to an independent burner nozzle. Due to the quenching effect of the small diameter, the micro-mixed pure hydrogen burner has a high anti-flashback ability, which is particularly suitable for active fuels such as hydrogen, and has a significant improvement on the flashback phenomenon compared to the swirl burner.

[0010] Furthermore, six air branch pipelines are provided, and the six air branch pipelines are distributed around the array; the hydrogen branch pipeline is provided corresponding to the air branch pipeline.

[0011] In this solution, six air branch pipes are designed to be evenly distributed to form six air nozzles. When the six air nozzles are working, six groups of combustion flames are generated. The six groups of combustion flames burn simultaneously, the flame temperature is high, and the heating speed is fast.

[0012] Furthermore, the diameter of the air nozzle is 5 mm; the six air nozzles are arranged in a hexagonal shape, and the center distance between two adjacent air nozzles is 20 mm.

[0013] Furthermore, six mixing pipelines are provided, and the six mixing pipelines are distributed around the array.

[0014] In this solution, six mixing pipelines are distributed around. When hydrogen is mixed with air, hydrogen enters the air pipeline from all sides of the air pipeline through the six mixing pipelines and mixes with the air inside the air pipeline, resulting in a good mixing effect.

[0015] Furthermore, the air pipeline is a double-layer structure with a solid middle, and the air flow channel is located between the double-layer structure.

[0016] In this solution, an annular air flow channel is designed between the double-layer structure, which can reduce the cross-sectional area of ​​the air flow channel inside the air pipeline and increase the air flow rate; at the same time, the annular air flow channel is convenient for connecting six surrounding air branch pipelines at its end.

[0017] Furthermore, an air inlet and a hydrogen inlet are respectively provided at one end of the air pipeline and the hydrogen pipeline away from the combustion head; the air inlet is connected to the air flow channel, and the hydrogen inlet is connected to the hydrogen flow channel.

[0018] In this solution, air is introduced into the air flow channel through the air inlet; hydrogen is introduced into the hydrogen flow channel through the hydrogen inlet.

[0019] Furthermore, the distance between the center axis of the mixing pipeline and the air nozzle is 15 mm.

[0020] In this scheme, hydrogen is sprayed into the air branch pipeline from six mixing pipelines. After being mixed for a certain distance in the air branch pipeline, the mixed gas is sprayed out from the air nozzle and burned, which extends the mixing distance of hydrogen inside the air branch pipeline and improves the mixing degree.

[0021] Furthermore, the pipe diameter of the mixing pipe is 0.4 mm.

[0022] In this solution, a small-aperture mixing pipeline is designed, and the flow rate of hydrogen inside it is small and the flow velocity is fast. After each unit of hydrogen passes through the mixing pipeline, it can be immediately mixed with the fast-flowing air, and the mixing effect is good.

[0023] Furthermore, the outer diameter of the combustion head is 80 mm.

[0024] The beneficial effects of the utility model are:

[0025] In the micro-mixed pure hydrogen burner provided by the utility model, each air nozzle is centered on the air branch pipeline, the hydrogen branch pipeline is wrapped outside it, and works independently in a premixing manner through the mixing pipeline; and the air and hydrogen are premixed in the small-diameter air branch pipeline, the premixing path is long, and a high degree of mixing can be achieved, which significantly reduces NO x emissions.

[0026] The end of the air branch pipe forms a small diameter air nozzle. Compared with the swirl flame of the traditional swirl burner, the single nozzle size of the burner is small, the flame high temperature area is small, there is no reflow area, and the NOx is reduced. x The generation in the flame zone. And the small diameter air nozzle makes the micro-mix burner have a high anti-flashback ability, reducing the flashback risk of the burner; it is suitable for the combustion of flammable and explosive gases such as hydrogen.

[0027] The length design of the air branch pipeline prolongs the premixing time of hydrogen; at the same time, the higher air flow velocity allows the flame to leave the burner head for a short distance, which can effectively prevent the combustion flame from damaging the combustion head. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the cross-sectional structure of a micro-mixed pure hydrogen burner of the utility model;

[0029] Figure 2This is a schematic diagram of the combustion head structure of the utility model;

[0030] Figure 3 for Figure 1 Schematic diagram of the AA section structure;

[0031] Figure 4 This is a schematic diagram of the cross-sectional structure of a single air nozzle of the utility model;

[0032] Figure 5 The utility model is a schematic diagram of the overall structure of a micro-mixed pure hydrogen burner.

[0033] Reference numerals:

[0034] 1. Air pipeline; 11. Air flow channel; 12. Air inlet; 2. Hydrogen pipeline; 21. Hydrogen flow channel; 22. Hydrogen inlet; 3. Mixing pipeline; 4. Combustion head; 41. Air branch pipeline; 42. Hydrogen branch pipeline; 43. Air nozzle; DETAILED DESCRIPTION

[0035] The utility model is further described below in conjunction with the accompanying drawings and specific embodiments. The specific implementation of the utility model is described below to facilitate the understanding of the utility model by those skilled in the art, but it should be clear that the utility model is not limited to the scope of the specific implementation. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the utility model defined and determined by the attached claims, these changes are obvious, and all inventions and creations conceived using the utility model are protected.

[0036] like Figure 1 As shown, this embodiment provides a micro-mixed pure hydrogen burner, which is designed with a mixing pipeline to premix hydrogen, and the premixing path is long and the mixing degree is high, which can reduce NO x The emission volume is reduced; at the same time, the small diameter nozzle design has a high anti-flashback ability, which reduces the flashback risk of the burner; specifically, it includes:

[0037] Air pipeline 1, hydrogen pipeline 2, mixing pipeline 3 and combustion head 4;

[0038] Among them, there is an air flow channel 11 inside the air pipeline 1, and a hydrogen pipeline 2 is sleeved on the outside of the air pipeline 1, and the interlayer between the air pipeline 1 and the hydrogen pipeline 2 is a hydrogen flow channel 21; one end of the air pipeline 1 is connected to the combustion head 4; the hydrogen flow channel 21 and the air flow channel 11 in the combustion head 4 are connected through a mixing pipeline 3; the hydrogen inside the hydrogen pipeline 2 enters the air pipeline 1 through the mixing pipeline 3, and mixes with the air inside it, thereby realizing the premixing of hydrogen and air, and the premixed mixed gas is then ejected from the combustion head 4.

[0039] like Figure 2 As shown, the combustion head 4 includes a plurality of air branch pipes 41 and an equal number of hydrogen branch pipes 42; a hydrogen branch pipe 42 is correspondingly sleeved on the outer side of each air branch pipe 41; a plurality of air branch pipes 41 are connected to the air pipe 1; a plurality of hydrogen branch pipes 42 are connected to the hydrogen pipe 2; each group of hydrogen branch pipes 42 and air branch pipes 41 are connected through a plurality of mixing pipes 3; the end of the air branch pipe 41 away from the air pipe 1 is an air nozzle 43; a plurality of groups of small-diameter air branch pipes 41 and hydrogen branch pipes 42 are designed, each group is equivalent to an independent burner nozzle, and due to the quenching effect of the small diameter, the micro-mixed pure hydrogen burner has a high anti-flashback ability, which is particularly suitable for active fuels such as hydrogen, and has a significant improvement in the flashback phenomenon compared to the swirl burner.

[0040] like Figure 3 As shown, six air branch pipes 41 are provided, and the six air branch pipes 41 are distributed around the array; the hydrogen branch pipes 42 are arranged one by one corresponding to the air branch pipes 41; the six air branch pipes 41 are designed to be evenly distributed to form six air nozzles 43, and the six air nozzles 43 generate six groups of combustion flames when working, and the six groups of combustion flames burn at the same time, the flame temperature is high, and the heating speed is fast.

[0041] Specifically, the diameter of the air nozzle 43 is 5 mm; the six air nozzles 43 are arranged in a hexagonal shape, and the center distance between two adjacent air nozzles 43 is 20 mm.

[0042] like Figure 4 As shown, six mixing pipelines 3 are provided, and the six mixing pipelines 3 are distributed around the array; when hydrogen is mixed with air in this design, hydrogen enters the air pipeline 1 from the four sides of the air pipeline 1 through the six mixing pipelines 3 and mixes with the air inside the air pipeline 1, and the mixing effect is good.

[0043] The air pipeline 1 is a double-layer structure with a solid middle. An annular air flow channel 11 is designed between the double-layer structure, which can reduce the cross-sectional area of ​​the air flow channel 11 inside the air pipeline 1 and increase the air flow rate; at the same time, the annular air flow channel 11 is convenient for connecting six surrounding air branch pipelines 41 at its end.

[0044] like Figure 5 As shown, the air pipeline 1 and the hydrogen pipeline 2 are respectively provided with an air inlet 12 and a hydrogen inlet 22 at the end away from the combustion head 4; the air inlet 12 is connected to the air flow channel 11, and the hydrogen inlet 22 is connected to the hydrogen flow channel 21; the air inlet 12 is used to introduce air into the air flow channel 11; the hydrogen inlet 22 is used to introduce hydrogen into the hydrogen flow channel 21.

[0045] As a preferred embodiment of the present invention, the distance between the center axis of the mixing pipeline 3 and the air nozzle 43 is 15 mm; hydrogen is sprayed into the air branch pipeline 41 from the six mixing pipelines 3, and after being mixed for a certain distance in the air branch pipeline 41, the mixed gas is sprayed out from the air nozzle 43 and burned, which prolongs the mixing distance of hydrogen in the air branch pipeline 41 and improves the mixing degree. The longer distance of the air pipeline 1 can fully develop the airflow, so that the intake uniformity of the six hydrogen branch pipelines 42 and the six air branch pipelines 41 is better.

[0046] As a preferred embodiment of the present invention, the diameter of the mixing pipeline 3 is 0.4 mm. The mixing pipeline 3 is designed with a small aperture, and the flow rate of hydrogen inside it is small and the flow rate is fast. After each unit of hydrogen passes through the mixing pipeline 3, it can be immediately mixed with the fast-flowing air, and the mixing effect is good.

[0047] As a preference of this embodiment, the outer diameter of the combustion head 4 is 80 mm.

[0048] The working principle of this embodiment is:

[0049] When the micro-mixed pure hydrogen burner provided in this embodiment is working, air is introduced into the air flow channel 11 from the air inlet 12, and hydrogen is introduced into the hydrogen flow channel 21 from the hydrogen inlet 22; the air and hydrogen are divided into six branches at the combustion head 4, and enter the air branch pipeline 41 and the hydrogen branch pipeline 42 respectively. The hydrogen in the hydrogen branch pipeline 42 passes through the mixing pipeline 3 and enters the air branch pipeline 41 to mix with the air, and the mixed gas is sprayed out from the air nozzle at the end of the air branch pipeline 41.

[0050] Those skilled in the art will appreciate that the embodiments herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations based on the technical inspiration disclosed in the present invention without departing from the essence of the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. A micro-mixed pure hydrogen burner, characterized in that: The invention comprises an air pipeline (1), a hydrogen pipeline (2), a mixing pipeline (3) and a combustion head (4); the interior of the air pipeline (1) is an air flow channel (11), the outer side of the air pipeline (1) is sleeved with the hydrogen pipeline (2), and the interlayer between the air pipeline (1) and the hydrogen pipeline (2) is a hydrogen flow channel (21); one end of the air pipeline (1) is connected to the combustion head (4); the hydrogen flow channel (21) and the air flow channel (11) in the combustion head (4) are connected via the mixing pipeline (3).

2. The micro-mixed pure hydrogen burner according to claim 1 is characterized in that: The combustion head (4) comprises a plurality of air branch pipes (41), and the plurality of air branch pipes (41) are all connected to the air pipe (1); an equal number of hydrogen branch pipes (42) are respectively sleeved on the outer sides of the plurality of air branch pipes (41), and the plurality of hydrogen branch pipes (42) are all connected to the hydrogen pipe (2); each group of hydrogen branch pipes (42) and the air branch pipe (41) are connected via a plurality of mixing pipes (3); and an end of the air branch pipe (41) away from the air pipe (1) is an air nozzle (43).

3. The micro-mixed pure hydrogen burner according to claim 2 is characterized in that: Six air branch pipelines (41) are provided, and the six air branch pipelines (41) are distributed around the array; the hydrogen branch pipeline (42) is arranged corresponding to the air branch pipeline (41).

4. The micro-mixed pure hydrogen burner according to claim 3 is characterized in that: The diameter of the air nozzle (43) is 5 mm; the six air nozzles (43) are arranged in a hexagonal shape, and the center distance between two adjacent air nozzles (43) is 20 mm.

5. The micro-mixed pure hydrogen burner according to claim 2 is characterized in that: There are six mixing pipelines (3), and the six mixing pipelines (3) are distributed around the array.

6. The micro-mixed pure hydrogen burner according to claim 1, characterized in that: The air pipeline (1) is a double-layer structure with a solid center, and the air flow channel (11) is located between the double-layer structure.

7. The micro-mixed pure hydrogen burner according to claim 6 is characterized in that: The air pipeline (1) and the hydrogen pipeline (2) are respectively provided with an air inlet (12) and a hydrogen inlet (22) at one end away from the combustion head (4); the air inlet (12) is connected to the air flow channel (11), and the hydrogen inlet (22) is connected to the hydrogen flow channel (21).

8. The micro-mixed pure hydrogen burner according to any one of claims 2 to 5, characterized in that: The distance between the center axis of the mixing pipeline (3) and the air nozzle (43) is 15 mm.

9. The micro-mixed pure hydrogen burner according to any one of claims 1 to 7, characterized in that: The diameter of the mixing pipeline (3) is 0.4 mm.

10. The micro-mixed pure hydrogen burner according to any one of claims 1 to 7, characterized in that: The outer diameter of the combustion head (4) is 80 mm.

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