A hydrogen fuel burner with staggered multi-point radial injection

Abstract

The present application relates to the technical field of combustor, and provides a hydrogen fuel combustor with staggered arrangement of multiple radial injection points, an inner cavity of a flame tube forms a combustion chamber, a ventilation device is arranged at one end of the flame tube, the ventilation device comprises a gas supply cavity, a gas supply pipe and a gas mixing cavity, the gas supply cavity is connected with the flame tube in an axial direction, the gas mixing cavity is arranged between the gas supply cavity and the flame tube, and the gas mixing cavity is communicated with the gas supply pipe, a plurality of micro-mixing injection pipes are staggered arranged in the gas mixing cavity, the micro-mixing injection pipes are arranged in an axial direction, a plurality of air inlet holes are uniformly distributed on the outer side of the micro-mixing injection pipes in a circumferential direction, the air inlet holes are communicated with the inside of the micro-mixing injection pipes, the air inlet holes of adjacent micro-mixing injection pipes are staggered arranged, a first end of the micro-mixing injection pipe is communicated with the combustion chamber, and a second end of the micro-mixing injection pipe is communicated with the inner cavity of the gas supply cavity; the present application realizes micro-mixing combustion of hydrogen, can effectively avoid the overlapping phenomenon of high-temperature zones between flames, makes the combustion stable, and reduces the emission of NOx in the combustion process.

Description

Technical Field

[0001] This invention relates to the field of burner technology, and more particularly to a hydrogen fuel burner with staggered multi-point radial injection. Background Technology

[0002] In daily life, natural gas is a commonly used fuel, resulting in a significant proportion of carbon emissions from it. However, hydrogen, with its cleanliness, high efficiency, and the decreasing cost due to the development and maturation of hydrogen energy technology, will eventually become an indispensable daily fuel.

[0003] Traditional natural gas burners mainly use a flue combustion method, which has a long mixing channel and a continuous flue flame. However, given the characteristics of hydrogen combustion, such as easy backfire and high emissions, flue combustion cannot achieve safe and low-emission combustion of hydrogen fuel. Moreover, current hydrogen burners usually only achieve excellent combustion performance at a relatively high pressure drop.

[0004] Therefore, how to provide a hydrogen fuel burner that can achieve low emissions and safe and stable combustion of hydrogen under extremely low pressure drop is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] This invention provides a hydrogen fuel burner with staggered multi-point radial injection to solve the defects of high emissions and easy explosion of hydrogen fuel burners in the prior art, and to achieve safe and low-emission combustion of hydrogen fuel.

[0006] This invention provides a hydrogen fuel burner with staggered multi-point radial injection, comprising:

[0007] A flame tube, the inner cavity of which forms a combustion chamber;

[0008] A ventilation device is disposed at one end of the flame tube. The ventilation device includes a gas supply chamber, a gas supply pipe, and a gas mixing chamber. The gas supply chamber is axially connected to the flame tube. The gas mixing chamber is disposed between the gas supply chamber and the flame tube and is connected to the gas supply pipe. Multiple micro-mixing nozzles are staggered in the gas mixing chamber. All micro-mixing nozzles are axially arranged. Multiple air inlets are evenly distributed circumferentially on the outer side of each micro-mixing nozzle. All air inlets are connected to the interior of each micro-mixing nozzle. The air inlets of adjacent micro-mixing nozzles are staggered. The first end of each micro-mixing nozzle is connected to the combustion chamber, and the second end of each micro-mixing nozzle is connected to the inner cavity of the gas supply chamber.

[0009] According to the hydrogen fuel burner with staggered multi-point radial injection provided by the present invention, at least a plurality of gas supply pipes are provided, and the plurality of gas supply pipes are arranged circumferentially on the outer side of the end of the flame tube and are all connected to the gas mixing chamber.

[0010] According to the hydrogen fuel burner with staggered multi-point radial injection provided by the present invention, a baffle is provided at the air inlet of the gas supply pipe.

[0011] According to the hydrogen fuel burner with staggered multi-point radial injection provided by the present invention, the gas mixing chamber includes a plurality of sub-accommodating chambers, the number of the sub-accommodating chambers being the same as the number of the gas supply pipes and corresponding one-to-one, and a partition is provided between two adjacent sub-accommodating chambers.

[0012] According to the hydrogen fuel burner with staggered multi-point radial injection provided by the present invention, each of the sub-receiving cavities has the same volume, and the number of micro-mixing nozzles in each of the sub-receiving cavities is the same.

[0013] According to the hydrogen fuel burner with staggered multi-point radial injection provided by the present invention, the first end of the micro-mixing nozzle is provided with a chamfer to form a conical flared structure.

[0014] According to the hydrogen fuel burner with staggered multi-point radial injection provided by the present invention, the chamfer angle α ranges from 30 to 60°.

[0015] According to the hydrogen fuel burner with staggered multi-point radial injection provided by the present invention, three air inlets are evenly distributed circumferentially on the outer side of the micro-mixing nozzle, and three vortex generators are provided inside the micro-mixing nozzle. The vortex generators correspond one-to-one with the air inlets, and the vortex generators are arranged upstream of the air inlets along a first direction, which is the direction from the second end of the micro-mixing nozzle to the first end of the micro-mixing nozzle.

[0016] According to the hydrogen fuel burner with staggered multi-point radial injection provided by the present invention, the vortex generator is provided with a first guide surface and a second guide surface corresponding to the second end of the micro-mixing nozzle. The first guide surface and the second guide surface have an angle. The vortex generator can divide the gas entering the second end of the micro-mixing nozzle and generate a pair of opposite vortices along the first guide surface and the second guide surface respectively.

[0017] According to the hydrogen fuel burner with staggered multi-point radial injection provided by the present invention, the vortex generator is a triangular pyramid structure.

[0018] The present invention provides a hydrogen fuel burner with staggered multi-point radial injection, comprising a flame tube and a venting device. The inner cavity of the flame tube forms a combustion chamber. The venting device is located at one end of the flame tube and includes a gas supply chamber, a gas supply pipe, and a gas mixing chamber. The gas supply chamber is axially connected to the flame tube, and the gas mixing chamber is located between the gas supply chamber and the flame tube, and is connected to the gas supply pipe. The present invention delivers gas entering the gas supply chamber to the combustion chamber through a micro-mixing nozzle in the gas mixing chamber. Simultaneously, hydrogen entering the gas mixing chamber through the gas supply pipe is uniformly diffused into the micro-mixing nozzle, mixing with the gas in the gas supply chamber, and then jointly delivered into the combustion chamber, ultimately forming a stable combustion flame. Hydrogen is introduced through the air inlet. By introducing micro-mixing nozzles, hydrogen can be micro-mixed and combusted, reducing the mixing scale between hydrogen and air. This invention arranges multiple micro-mixing nozzles in a staggered manner, with each nozzle having multiple air inlets that can each form a flame source. Compared to a single flame source, multiple air inlets allow for faster mixing and combustion with air, resulting in a more uniform heat distribution. Compared to the traditional square array arrangement of micro-mixing nozzles, the staggered arrangement of multiple nozzles and the staggered air inlets of adjacent nozzles maximizes the spacing between the combustion flames produced by each nozzle. This effectively avoids the overlap of high-temperature zones between flames, ensuring safe and stable combustion and reducing combustion emissions. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a front view of a hydrogen fuel burner with staggered multi-point radial injection provided in an embodiment of the present invention.

[0021] Figure 2 for Figure 1 A sectional view along direction AA.

[0022] Figure 3 for Figure 1 A sectional view along the BB direction.

[0023] Figure 4 This is a schematic diagram of the micro-mixing nozzle provided in an embodiment of the present invention.

[0024] Figure 5 This is a cross-sectional view of the micro-mixing nozzle provided in an embodiment of the present invention.

[0025] Figure 6This is a top view of the micro-mixing nozzle provided in an embodiment of the present invention.

[0026] Figure label:

[0027] 1. Flame tube; 2. Air supply chamber; 3. Air supply pipe; 4. Gas mixing chamber; 5. Micro-mixing nozzle; 6. Air inlet; 7. Baffle; 8. Divider; 9. Vortex generator. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0029] The following is combined with Figures 1-6 The present invention describes a hydrogen fuel burner with staggered arrangement of multiple radial injection points.

[0030] This embodiment provides a hydrogen fuel burner with staggered multi-point radial injection, including: a flame tube 1 and a ventilation device.

[0031] Among them, such as Figure 1 and Figure 2 As shown, the inner cavity of the flame tube 1 forms a combustion chamber; a ventilation device is installed at one end of the flame tube 1, and the ventilation device includes a gas supply chamber 2, a gas supply pipe 3, and a gas mixing chamber 4. The gas supply chamber 2 can be used to transport air, and the gas supply pipe 3 is used to transport hydrogen. The gas supply chamber 2 is axially connected to the flame tube 1. The gas mixing chamber 4 is located between the gas supply chamber 2 and the flame tube 1, and the gas mixing chamber 4 is connected to the gas supply pipe 3. Multiple micro-mixing nozzles 5 are arranged alternately in the gas mixing chamber 4. The micro-mixing nozzles 5 are all axially arranged. Multiple air inlets 6 are evenly distributed circumferentially on the outer side of the micro-mixing nozzles 5. The multiple air inlets 6 are all connected to the inside of the micro-mixing nozzles 5. The air inlets 6 of adjacent micro-mixing nozzles 5 are staggered. The first end of the micro-mixing nozzle 5 is connected to the combustion chamber, and the second end of the micro-mixing nozzle 5 is connected to the inner cavity of the gas supply chamber 2.

[0032] Through the above scheme, the present invention sets up a gas mixing chamber 4 between the combustion chamber and the gas supply chamber 2, and places a micro-mixing nozzle 5 in the gas mixing chamber 4. This allows the hydrogen entering the gas mixing chamber 4 to diffuse evenly into the micro-mixing nozzle 5. The gas entering the gas supply chamber 2 is transported to the combustion chamber through the micro-mixing nozzle 5 in the gas mixing chamber 4. At the same time, the hydrogen in the gas supply pipe 3 enters the micro-mixing nozzle 5 through the air inlet 6, mixes with the gas in the gas supply chamber 2 in the micro-mixing nozzle 5, and is jointly sent into the combustion chamber, realizing the micro-mixing combustion of hydrogen. This reduces the mixing scale of hydrogen and air, ultimately forming a stable combustion flame. The present invention uses multiple micro-mixing nozzles... 5. By setting up a staggered arrangement, each of the multiple air inlets 6 on the micro-mixing nozzle 5 can form a flame source. Compared with a single flame source, setting multiple air inlets 6 can mix and burn with air more quickly, which helps to achieve a more uniform heat distribution. Compared with the traditional square array arrangement of micro-mixing nozzles 5, the staggered arrangement of multiple micro-mixing nozzles 5 and the staggered arrangement of the air inlets 6 of adjacent micro-mixing nozzles 5 can maximize the spacing between the combustion flames generated by each micro-mixing nozzle 5, which can effectively avoid the overlap of high-temperature zones between flames, making combustion safe and stable, and reducing NOx emissions during the combustion process.

[0033] In some embodiments, at least a plurality of gas supply pipes 3 are provided, which are evenly arranged circumferentially on the outer side of the end of the flame tube 1 and are all connected to the gas mixing chamber 4. This arrangement ensures a uniform gas supply around the flame tube 1 by uniformly distributing multiple gas supply pipes 3 to the gas mixing chamber 4. This uniform hydrogen supply facilitates thorough mixing with air, contributing to stable and uniform combustion, maintaining consistent power across each micro-mixing nozzle 5, resulting in more stable burner operation. Simultaneously, it makes the temperature distribution within the flame tube 1 more uniform, with smaller high-temperature zones, leading to relatively lower NOx emissions and thus reducing environmental pollution.

[0034] The gas supply can be adjusted by increasing or decreasing the number of gas supply pipes 3 to adapt to different combustion requirements, thereby improving the flexibility and adaptability of the combustion system.

[0035] Reference Figure 3 In this embodiment, a baffle 7 is provided at the air inlet of the air supply pipe 3. The baffle 7 can be positioned directly opposite the air inlet of the air supply pipe 3. For example, the shape of the baffle 7 can be a triangle, an ellipse, a rectangle, or other polygons. A connection gap is reserved between the baffle 7 and the inner wall of the air supply pipe 3 so that the gas blown toward the baffle 7 can diffuse in all directions and enter the gas mixing chamber 4 from the connection gap reserved between the baffle 7 and the inner wall of the air supply pipe 3.

[0036] This configuration slows down the hydrogen supplied by the gas supply pipe 3 via the baffle 7. The reduced gas supply means that the speed at which the gas enters the gas mixing chamber 4 is reduced, avoiding the impact of the high gas flow rate on the air inlet 6 of the micro-mixing nozzle 5 near the gas supply pipe 3. This makes the hydrogen more evenly distributed in the gas mixing chamber 4, which helps the hydrogen and air mix more fully, reduces pressure and temperature fluctuations in the flame tube 1, reduces safety risks, and improves combustion efficiency, resulting in more complete combustion.

[0037] Reference Figure 3 In this embodiment, the gas mixing chamber 4 includes multiple sub-containment chambers. The number of sub-containment chambers is the same as the number of gas supply pipes 3 and they correspond one-to-one. A partition 8 is provided between two adjacent sub-containment chambers.

[0038] This configuration, by dividing the gas mixing chamber 4 into multiple parts, can effectively achieve stable combustion under low operating conditions. For example, by setting a baffle 8 to divide the gas mixing chamber 4 into two parts, and setting two gas supply pipes 3 opposite to each other to connect to the two sub-containment chambers respectively, under low load conditions, the hydrogen supply to one sub-containment chamber can be selectively shut off, and only one gas supply pipe 3 can be opened to make the micro-mixing nozzle 5 in one sub-containment space work, thereby achieving stable combustion under low operating conditions.

[0039] Of course, the gas mixing chamber 4 can also be divided into at least three parts by the partition 8, for example, forming three sub-containment chambers, four sub-containment chambers, etc., and a corresponding number of gas supply pipes 3 are provided, so that each sub-containment chamber is provided with a gas supply pipe 3 for supplying gas to it.

[0040] Furthermore, to promote more stable combustion, each sub-containment chamber has the same volume, and the number of micro-mixing nozzles 5 in each sub-containment chamber is the same.

[0041] Optionally, each sub-accommodating cavity has a different volume, and the number of micro-mixing nozzles 5 in each sub-accommodating cavity is also different. This setting can achieve smooth switching under various operating conditions. By setting sub-accommodating cavities with different capacity levels and making the number of micro-mixing nozzles 5 in each sub-accommodating cavity proportional to the cavity capacity, different power levels can be selected. For example, three sub-accommodating cavities can be set with a volume ratio of 1:2:3 to meet the step-by-step smooth adjustment of every 5kW under a maximum power of 30kW.

[0042] Reference Figure 4 and Figure 5In this embodiment, the first end of the micro-mixing nozzle 5 is chamfered to form a conical flare structure. That is, the end of the micro-mixing nozzle 5 corresponding to the combustion chamber is set as a conical flare structure. With this setting, the conical flare can prevent the flames generated by each micro-mixing nozzle 5 from adhering to or hanging on the wall of the combustion chamber inlet under low pressure drop conditions, so that the wall is continuously burned and the service life is reduced. It is also beneficial to the flow of mixed gas. When the gas enters the conical flare, the gas flow rate gradually decreases due to the gradual increase in area, and the flow is more stable, which is conducive to better distribution and mixing of gas in the combustion chamber and improves combustion efficiency.

[0043] Reference Figure 5 In some embodiments, the outer diameter D1 of the micro-mixing nozzle 5 ranges from 7 to 12 mm, the inner diameter D2 ranges from 6 to 10 mm, the diameter d of the air inlet 6 ranges from 1 to 2 mm, and the chamfer angle a of the tapered flare ranges from 30 to 60°.

[0044] In this embodiment, three air inlets 6 are evenly distributed circumferentially on the outer side of the micro-mixing nozzle 5, and three vortex generators 9 are installed inside the micro-mixing nozzle 5. The vortex generators 9 correspond one-to-one with the air inlets 6, forming a clover-shaped design in the micro-mixing nozzle 5. The vortex generators 9 are positioned upstream of the air inlets 6 along a first direction, which is the direction from the second end of the micro-mixing nozzle 5 to the first end of the micro-mixing nozzle 5. That is, when air enters the micro-mixing nozzle 5, it first passes through the vortex generators 9 and then through the air inlets 6, mixing with the hydrogen entering from the air inlets 6. Each air inlet 6 can form a flame source. Compared with a single flame source, it can mix and burn with air more quickly, reduce hydrogen loss, consume hydrogen faster, improve safety, and increase the combustion point in the combustion chamber, which helps to achieve a more uniform heat distribution and improve the overall combustion efficiency.

[0045] It should be noted that the number of air inlets 6 should not be too many, preferably three. When there are too many air inlets 6, the multiple flames may interfere with each other, resulting in flame instability and flame chaining, which leads to excessively high temperatures in the combustion zone, increases the risk of combustion runaway, and also increases the difficulty of flame cooling. At the same time, it will also cause the high-temperature zones of the flame to overlap, forming a concentrated high-temperature zone, which is not conducive to controlling NOx emissions. Furthermore, the presence of multiple flames will occupy more space, making the arrangement of microtubes more difficult.

[0046] Specifically, the vortex generator 9 is provided with a first guide surface and a second guide surface at the second end of the micro-mixing nozzle 5. The first guide surface and the second guide surface have an angle. The vortex generator 9 can divide the gas entering the second end of the micro-mixing nozzle 5 and generate a pair of opposite vortices along the first guide surface and the second guide surface respectively.

[0047] In some embodiments, the vortex generator 9 is a triangular pyramid structure with the cone angle facing the second end of the micro-mixing nozzle 5. For a single vortex generator 9, when air flows in, it passes through the two sides of the triangular pyramid to generate a pair of opposing rotating vortices. Downstream hydrogen is injected at a certain speed, and the two opposing rotating vortices respectively entrain hydrogen and the surrounding air vortices, effectively enhancing the mixing of hydrogen and air and greatly increasing the mixing efficiency of hydrogen and air.

[0048] Reference Figure 5 and Figure 6 In this embodiment, the distance s from the end of the vortex generator 9 to the center of the air inlet 6 ranges from 1 to 3.6 mm, the length w of the bottom surface of the triangular pyramidal vortex generator 9 ranges from 1.2 to 2.8 mm, the height h of the bottom surface ranges from 1.6 to 3.6 mm, and the height H of the side surface ranges from 1.6 to 3.2 mm.

[0049] The hydrogen fuel burner with staggered multi-point radial injection provided by this invention can operate safely under ultra-low pressure drops of no more than 350 Pa and no more than 600 Pa. It can achieve low emissions of hydrogen fuel through micro-mixing technology and effectively avoid combustion backfire and other difficulties in hydrogen combustion through diffusion flame.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hydrogen fuel burner with staggered multi-point radial injection, characterized in that, The application relates to a gas burner, which comprises: a flame tube (1) with an inner cavity forming a combustion chamber; an air supply device arranged at one end of the flame tube (1), which comprises an air supply cavity (2), an air supply pipe (3) and a gas mixing cavity (4), the air supply cavity (2) is connected with the flame tube (1) in an axial direction, the gas mixing cavity (4) is arranged between the air supply cavity (2) and the flame tube (1), and the gas mixing cavity (4) is communicated with the air supply pipe (3), a plurality of micro-mixing nozzles (5) are arranged in the gas mixing cavity (4) in a staggered manner, the micro-mixing nozzles (5) are arranged in an axial direction, a plurality of air inlet holes (6) are arranged on the outer side of the micro-mixing nozzles (5) in a circumferential direction, the air inlet holes (6) are communicated with the inner part of the micro-mixing nozzles (5), the air inlet holes (6) of adjacent micro-mixing nozzles (5) are arranged in a staggered manner, the first end of the micro-mixing nozzle (5) is communicated with the combustion chamber, and the second end of the micro-mixing nozzle (5) is communicated with the inner cavity of the air supply cavity (2); the outer side of the micro-mixing nozzle (5) is arranged with three air inlet holes (6) in a circumferential direction, three vortex generators (9) are arranged in the micro-mixing nozzle (5), the vortex generators (9) correspond to the air inlet holes (6) one by one, and the vortex generators (9) are arranged at the upstream of the air inlet holes (6) in a first direction, the first direction is a direction from the second end of the micro-mixing nozzle (5) to the first end of the micro-mixing nozzle (5); the vortex generators (9) are provided with a first guide surface and a second guide surface corresponding to the second end of the micro-mixing nozzle (5), the first guide surface and the second guide surface form an included angle, and the vortex generators (9) can divide the gas entering the second end of the micro-mixing nozzle (5) and generate a pair of opposite vortexes along the first guide surface and the second guide surface respectively.

2. The staggered multi-point radial injection hydrogen fuel burner of claim 1, wherein, The air supply pipe (3) is arranged at least in plurality, and the air supply pipes (3) are arranged on the outer side of the end of the flame tube (1) in a circumferential direction and communicated with the gas mixing cavity (4).

3. The staggered multi-point radial injection hydrogen fuel burner of claim 2, wherein, A baffle (7) is arranged at the air inlet of the air supply pipe (3).

4. The staggered multi-point radial injection hydrogen fuel burner of claim 2, wherein, The gas mixing cavity (4) comprises a plurality of sub-cavities, the number of the sub-cavities is the same as and corresponds to the number of the air supply pipes (3), and a partition plate (8) is arranged between adjacent two sub-cavities.

5. The staggered multi-point radial injection hydrogen fuel burner of claim 4, wherein, The volume of each sub-cavity is the same, and the number of the micro-mixing nozzles (5) in each sub-cavity is the same.

6. The staggered multi-point radial injection hydrogen fuel burner of claim 1, wherein, The first end of the micro-mixing nozzle (5) is provided with a chamfer to form a conical flared structure.

7. The staggered multi-point radial injection hydrogen fuel burner of claim 6, wherein, The angle a of the chamfer ranges from 30 to 60 degrees.

8. The staggered multi-point radial injection hydrogen fuel burner of claim 1, wherein, The vortex generator (9) is a triangular pyramid structure.

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